Walter Klimecki

Interests

No activities entered.

Courses

Scholarly Contributions

Journals/Publications

• Alkhatib, N., Sweitzer, N. K., Lee, C. S., Erstad, B., Slack, M., Gharaibeh, M., Karnes, J., Klimecki, W., Ramos, K., & Abraham, I. (2021). Ex Ante Economic Evaluation of Arg389 Genetically Targeted Treatment with Bucindolol versus Empirical Treatment with Carvedilol in NYHA III/IV Heart Failure. American journal of cardiovascular drugs : drugs, devices, and other interventions, 21(2), 205-217.
  More info

  The Beta-Blocker Evaluation Survival Trial showed no survival benefit for bucindolol in New York Heart Association (NYHA) class III/IV heart failure (HF) with reduced ejection fraction, but subanalyses suggested survival benefits for non-Black subjects and Arg389 homozygotes. We conducted an ex ante economic evaluation of Arg389 targeted treatment with bucindolol versus carvidolol, complementing a previous ex ante economic evaluation of bucindolol preceded by genetic testing for the Arg389 polymorphism, in which genetic testing prevailed economically over no testing.
• Beamer, P. -., Beamer, P. -., Beamer, P. -., Sugeng, A. J., Sugeng, A. J., Sugeng, A. J., Kelly, M. D., Kelly, M. D., Kelly, M. D., Lothrop, N., Lothrop, N., Lothrop, N., Klimecki, W. -., Klimecki, W. -., Klimecki, W. -., Wilkinson, S. T., Wilkinson, S. T., Wilkinson, S. T., Loh, M. M., , Loh, M. M., et al. (2014). Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings. Environmental Science Processes and Impacts.
• Beamer, P. -., Sugeng, A. J., Kelly, M. D., Lothrop, N., Klimecki, W. -., Wilkinson, S. T., & Loh, M. M. (2014). Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine taillings.. Environmental Science:Processes and Impacts.
• Grace, C., Larriva, M. M., Steiner, H. E., Marupuru, S., Campbell, P. J., Patterson, H., Cropp, C. D., Quinn, D., Klimecki, W., Nix, D. E., Warholak, T., & Karnes, J. H. (2021). Efficacy of personal pharmacogenomic testing as an educational tool in the pharmacy curriculum: A nonblinded, randomized controlled trial. Clinical and translational science, 14(6), 2532-2543.
  More info

  Personal genomic educational testing (PGET) has been suggested as a strategy to improve student learning for pharmacogenomics (PGx), but no randomized studies have evaluated PGET's educational benefit. We investigated the effect of PGET on student knowledge, comfort, and attitudes related to PGx in a nonblinded, randomized controlled trial. Consenting participants were randomized to receive PGET or no PGET (NPGET) during 4 subsequent years of a PGx course. All participants completed a pre-survey and post-survey designed to assess (1) PGx knowledge, (2) comfort with PGx patient education and clinical skills, and (3) attitudes toward PGx. Instructors were blinded to PGET assignment. The Wilcoxon Rank Sum test was used to compare pre-survey and post-survey PGx knowledge, comfort, and attitudes. No differences in baseline characteristics were observed between PGET (n = 117) and NPGET (n = 116) participants. Among all participants, significant improvement was observed in PGx knowledge (mean 57% vs. 39% correct responses; p 
• Klimentidis, Y. C., Bea, J. W., Chen, Z., Klimecki, W., & Hu, C. (2015). Genetic Variant in ACVR2B Is Associated with Lean Mass. Medicine & Science in Sports & Exercise.
• Klimentidis, Y. C., Bea, J. W., Thompson, P., Klimecki, W. T., Hu, C., Wu, G., Nicholas, S., Ryckman, K. K., & Chen, Z. (2014). Genetic variant in ACVR2B is associated with lean mass. WHI P&P / Journal TBD.
• Loh, M. M., Sugeng, A., Lothrop, N., Klimecki, W. -., Wilkinson, S., & Beamer, P. -. (2014). Multimedia Exposures to Arsenic and Lead for Children in a Community Near a Former Mine Tailings and Smelter Site. Environmental Research.
• Lothrop, N. Z., Wilkinson, S. T., Verhougstraete, M., Sugeng, A., Loh, M. M., Klimecki, W., & Beamer, P. I. (2014). Home Water Treatment Habits and Effectiveness in a Rural Arizona Community. Water.
• Ramirez-Andreotta, M. D., Lothrop, N. Z., Wilkinson, S. T., Root, R. A., Artiola, J. F., Klimecki, W., & Loh, M. M. (2014). Analyzing Patterns of Community Interest at a Legacy Mining Waste Site to Assess and Inform Environmental Health Literacy Efforts. Environmental Studies and Sciences.
• Sweitzer, N. K., Klimecki, W. T., Karnes, J. H., Abraham, I., Sweitzer, N. K., Slack, M. K., Ramos, K. S., Lee, C. S., Klimecki, W. T., Karnes, J. H., Gharaibeh, M., Erstad, B. L., Alkhatib, N. S., & Abraham, I. (2021). Ex Ante Economic Evaluation of Arg389 Genetically Targeted Treatment with Bucindolol versus Empirical Treatment with Carvedilol in NYHA III/IV Heart Failure.. American Journal of Cardiovascular Drugs, 21(2), 205-217. doi:10.1007/s40256-020-00425-x
  More info

  The Beta-Blocker Evaluation Survival Trial showed no survival benefit for bucindolol in New York Heart Association (NYHA) class III/IV heart failure (HF) with reduced ejection fraction, but subanalyses suggested survival benefits for non-Black subjects and Arg389 homozygotes. We conducted an ex ante economic evaluation of Arg389 targeted treatment with bucindolol versus carvidolol, complementing a previous ex ante economic evaluation of bucindolol preceded by genetic testing for the Arg389 polymorphism, in which genetic testing prevailed economically over no testing. A decision tree analysis with an 18-month time horizon was performed to estimate the cost effectiveness/cost utility of trajectories of 100%, 50%, and 0% of patients genetically tested for Arg389 and comparing bucindolol with empirical carvedilol treatment as per prior BEST subanalyses. Incremental cost-effectiveness/cost-utility ratios (ICERs/ICURs) were estimated. Race-based analyses for non-White subjects at 100% testing showed a loss of (0.04) life-years and (0.03) quality-adjusted life-years (QALYs) at an incremental cost of $2185, yielding a negative ICER of ($54,625)/life-year and ICUR of ($72,833)/QALY lost; at 50%, the analyses showed a loss of (0.27) life-years and (0.16) QALYs at an incremental cost of $1843, yielding a negative ICER of ($6826)/life-year and ICUR of ($11,519)/QALY lost; at 0%, the analyses showed a loss of (0.33) life-years and (0.30) QALYs at an incremental cost of $1459, yielding a negative ICER of ($4421)/life-year and ICUR of ($4863)/QALY lost. Arg389 homozygote analyses at 100% testing showed incremental gains of 0.02 life-years and 0.02 QALYs at an incremental cost of $378, yielding an ICER of 18,900/life-year and ICUR of $18,900/QALY gained; at 50%, the analyses showed a loss of (0.24) life-years and (0.09) QALYs at an incremental cost of $1039, yielding a negative ICER of ($4329)/life-year and ICUR of ($9336)/QALY lost; at 0%, the analyses showed a loss of (0.33) life-years and (0.30) QALYs at an incremental cost of $1459, yielding a negative ICER of ($4421)/life-year and ICUR of ($4863)/QALY lost. This independent ex ante economic evaluation suggests that genetically targeted treatment with bucindolol is unlikely to yield clinicoeconomic benefits over empirical treatment with carvedilol in NYHA III/IV HF.
• Warholak, T., Steiner, H. E., Quinn, D., Patterson, H., Nix, D. E., Marupuru, S., Larriva, M. M., Klimecki, W., Karnes, J. H., Grace, C., Cropp, C. D., & Campbell, P. J. (2021). Efficacy of personal pharmacogenomic testing as an educational tool in the pharmacy curriculum: A nonblinded, randomized controlled trial.. Clinical and translational science. doi:10.1111/cts.13121
  More info

  Personal genomic educational testing (PGET) has been suggested as a strategy to improve student learning for pharmacogenomics (PGx), but no randomized studies have evaluated PGET's educational benefit. We investigated the effect of PGET on student knowledge, comfort, and attitudes related to PGx in a nonblinded, randomized controlled trial. Consenting participants were randomized to receive PGET or no PGET (NPGET) during 4 subsequent years of a PGx course. All participants completed a pre-survey and post-survey designed to assess (1) PGx knowledge, (2) comfort with PGx patient education and clinical skills, and (3) attitudes toward PGx. Instructors were blinded to PGET assignment. The Wilcoxon Rank Sum test was used to compare pre-survey and post-survey PGx knowledge, comfort, and attitudes. No differences in baseline characteristics were observed between PGET (n = 117) and NPGET (n = 116) participants. Among all participants, significant improvement was observed in PGx knowledge (mean 57% vs. 39% correct responses; p < 0.001) with similar results for student comfort and attitudes. Change in pre/post-PGx knowledge, comfort, and attitudes were not significantly different between PGET and NPGET groups (mean 19.5% vs. 16.7% knowledge improvement, respectively; p = 0.41). Similar results were observed for PGET participants carrying a highly actionable PGx variant versus PGET participants without an actionable variant. Significant improvement in Likert scale responses were observed in PGET versus NPGET for questions that assessed student engagement (p = 0.020) and reinforcement of course concepts (p = 0.006). Although some evidence of improved engagement and participation was observed, the results of this study suggest that PGET does not directly improve student PGx knowledge, comfort, and attitudes.
• Amouzougan, E. A., Lira, R., & Klimecki, W. T. (2020). Chronic exposure to arsenite enhances influenza virus infection in cultured cells. Journal of applied toxicology : JAT, 40(4), 458-469.
  More info

  Arsenic is a ubiquitous environmental toxicant that has been associated with human respiratory diseases. In humans, arsenic exposure has been associated with increased risk of respiratory infection. Considering the existing epidemiological evidence and the well-established impact of arsenic on epithelial cell biology, we posited that the effect of arsenic exposure in epithelial cells could enhance viral infection. In this study, we characterized influenza virus A/WSN/33 (H1N1) infection in Madin-Darby Canine Kidney (MDCK) cells chronically exposed to low levels of sodium arsenite (75 ppb). We observed a 27.3-fold increase in viral matrix (M2) protein (24 hours postinfection [p.i.]), a 1.35-fold increase in viral mRNA levels, and a 126% increase in plaque area in arsenite-exposed MDCK cells (48 hours p.i.). Arsenite exposure resulted in 114% increase in virus attachment-positive cells (2 hours p.i.) and 224% increase in α-2,3 sialic acid-positive cells. Interestingly, chronic exposure to arsenite reduced the effect of the antiviral drug, oseltamivir in MDCK cells. We also found that exposure to sodium arsenite resulted in a 4.4-fold increase in viral mRNA levels and significantly increased cytotoxicity in influenza A/Udorn/72 (H3N2) infected BEAS-2B cells. This study suggests that chronic arsenite exposure could result in enhanced influenza infection in epithelial cells, and that this may be mediated through increased sialic acid binding. Finally, the decreased effectiveness of the anti-influenza drug, oseltamivir, in arsenite-exposed cells raises substantial public health concerns if this effect translates to arsenic-exposed, influenza-infected people.
• Hogan, D. E., Tian, F., Malm, S. W., Kegel, L. L., Szabo, L. Z., Hunjan, A. S., Pemberton, J. E., Klimecki, W. T., Polt, R., & Maier, R. M. (2020). Biodegradability and Toxicity of Cellobiosides and Melibiosides. Journal of surfactants and detergents, 23(4), 715-724.
  More info

  In 2014, almost 16 million tons of surfactants were used globally for cleaning and industrial applications. As a result, massive quantities disperse into environmental compartments every day. There is great market interest in developing highly biodegradable, less-toxic, and renewable alternatives to currently used petroleum-based surfactants. Glycolipid surfactants, composed of a sugar head-group and lipid tail, are effective surfactants and emulsifiers with a high tolerance to electrolytes and are easily tailored to address specific needs. The green synthesis and surfactant characteristics of a suite of cellobiosides and melibiosides were recently described. The biodegradability and toxicity of 1°-alkyl-O-cellobiosides, 2°-alkyl-O-cellobiosides, and 1°-alkyl-O-melibiosides with straight-chain alkyl tails of 8, 10, and 12 are reported in this study. Biodegradability was assessed by quantifying mineralization (CO evolution). All of the glycosides were inherently biodegradable and most were readily biodegradable according to OECD and EPA definitions. The Microtox acute toxicity assay showed both chain length and head group had significant effects on toxicity, but most of the molecules were practically non-toxic according to EPA definitions with EC values > 100 mg L. Cytotoxicity to human lung (H1299) and keratinocyte cell lines (HaCaT) was measured by xCELLigence and MTS assays. Cytotoxicity values were comparable to similar glycosides previously reported. IC values were determined but, in general, exceeded surfactant concentrations that are found in the environment. These data demonstrate the promising nature of these molecules as green alternatives to petrochemical surfactants.
• Lira, R., Klimecki, W. T., & Amouzougan, E. A. (2020). Chronic exposure to arsenite enhances influenza virus infection in cultured cells.. Journal of applied toxicology : JAT, 40(4), 458-469. doi:10.1002/jat.3918
  More info

  Arsenic is a ubiquitous environmental toxicant that has been associated with human respiratory diseases. In humans, arsenic exposure has been associated with increased risk of respiratory infection. Considering the existing epidemiological evidence and the well-established impact of arsenic on epithelial cell biology, we posited that the effect of arsenic exposure in epithelial cells could enhance viral infection. In this study, we characterized influenza virus A/WSN/33 (H1N1) infection in Madin-Darby Canine Kidney (MDCK) cells chronically exposed to low levels of sodium arsenite (75 ppb). We observed a 27.3-fold increase in viral matrix (M2) protein (24 hours postinfection [p.i.]), a 1.35-fold increase in viral mRNA levels, and a 126% increase in plaque area in arsenite-exposed MDCK cells (48 hours p.i.). Arsenite exposure resulted in 114% increase in virus attachment-positive cells (2 hours p.i.) and 224% increase in α-2,3 sialic acid-positive cells. Interestingly, chronic exposure to arsenite reduced the effect of the antiviral drug, oseltamivir in MDCK cells. We also found that exposure to sodium arsenite resulted in a 4.4-fold increase in viral mRNA levels and significantly increased cytotoxicity in influenza A/Udorn/72 (H3N2) infected BEAS-2B cells. This study suggests that chronic arsenite exposure could result in enhanced influenza infection in epithelial cells, and that this may be mediated through increased sialic acid binding. Finally, the decreased effectiveness of the anti-influenza drug, oseltamivir, in arsenite-exposed cells raises substantial public health concerns if this effect translates to arsenic-exposed, influenza-infected people.
• Maier, R. M., Polt, R. L., Klimecki, W., Pemberton, J. E., Hunjan, A. S., Szabo, L. Z., Kegel, L. L., Malm, S. W., Tian, F., & Hogan, D. E. (2020). Biodegradability and toxicity of cellobiosides and melibiosides. Journal of Surfactants and Detergents. doi:10.1002/jsde.12421
• Maier, R. M., Polt, R. L., Klimecki, W., Pemberton, J. E., Hunjan, A. S., Szabo, Z., Kegel, L. L., Malm, S. W., Tian, F., & Hogan, D. E. (2020). Biodegradability and Toxicity of Cellobiosides and Melibiosides. Journal of Surfactants and Detergents, 23, 715-724.
• Tian, F., Szabo, L. Z., Polt, R., Pemberton, J. E., Malm, S. W., Maier, R. M., Klimecki, W. T., Kegel, L. L., Hunjan, A. S., & Hogan, D. E. (2020). Biodegradability and Toxicity of Cellobiosides and Melibiosides. Journal of Surfactants and Detergents, 23(4), 715-724. doi:10.1002/jsde.12421
• Klimecki, W. T., Pemberton, J. E., Curry, J. E., Olivares, C. I., Tian, F., Tanguay, R. L., Simonich, M. T., Polt, R., Pemberton, J. E., Pacheco, R. P., Olivares, C. I., Malm, S. W., Maier, R. M., Klimecki, W. T., Hunjan, A. S., Hogan, D. E., & Curry, J. E. (2019). Biodegradability and toxicity of monorhamnolipid biosurfactant diastereomers.. Journal of hazardous materials, 364, 600-607. doi:10.1016/j.jhazmat.2018.10.050
  More info

  Synthetic monorhamnolipids differ from biologically produced material because they are produced as single congeners, depending on the β-hydroxyalkanoic acid used during synthesis. Each congener is produced as one of four possible diastereomers resulting from two chiral centers at the carbinols of the lipid tails [(R,R), (R,S), (S,R) and (S,S)]. We compare the biodegradability (CO2 respirometry), acute toxicity (Microtox assay), embryo toxicity (Zebrafish assay), and cytotoxicity (xCELLigence and MTS assays) of synthetic rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-C10-C10) monorhamnolipids against biosynthesized monorhamnolipid mixtures (bio-mRL). All Rha-C10-C10 diastereomers and bio-mRL were inherently biodegradable ranging from 34 to 92% mineralized. The Microtox assay showed all Rha-C10-C10 diastereomers and bio-mRL are slightly toxic according to the US EPA ecotoxicity categories with 5 min EC50 values ranging from 39.6 to 87.5 μM. The zebrafish assay showed that of 22 developmental endpoints tested, only mortality was observed at 120 h post fertilization; all Rha-C10-C10 diastereomers and bio-mRL caused significant mortality at 640 μM, except the Rha-C10-C10 (R,R) which showed no developmental effects. xCELLigence and MTS showed IC50 values ranging from 103.4 to 191.1 μM for human lung cell line H1299 after 72 h exposure. These data provide key information regarding Rha-C10-C10 diastereomers that is pertinent when considering potential applications.
• Maier, R. M., Curry, J. E., Pemberton, J. E., Polt, R. L., Klimecki, W., Tanguay, R. L., Hunjan, A. S., Simonich, M., Palos Pacheco, R., Olivares, C., Malm, S. W., Tian, F., & Hogan, D. E. (2019). Biodegradability and toxicity of monorhamnolipid biosurfactant diastereomers. Journal of Hazardous Materials, 364, 600-607. doi:10.1016/j.jhazmat.2018.10.050
• Alkhatib, N., Abraham, I. L., Ramos, K., Sweitzer, N. K., Gharaibeh, M., Klimecki, W., Slack, M. K., Karnes, J. H., Erstad, B. L., Erstad, B. L., Karnes, J. H., Slack, M. K., Gharaibeh, M., Klimecki, W., Sweitzer, N. K., Ramos, K., Alkhatib, N., & Abraham, I. L. (2018). Economic evaluation of genetic testing for Arg389 in the management of stage III/IV heart failure.. Expert Review of Precision Medicine and Drug Development, 3, 319-329.
• Hogan, D. E., Tian, F., Malm, S. W., Olivares, C., Palos Pacheco, R., Simonich, M. T., Hunjan, A. S., Tanguay, R. L., Klimecki, W. T., Polt, R., Pemberton, J. E., Curry, J. E., & Maier, R. M. (2018). Biodegradability and toxicity of monorhamnolipid biosurfactant diastereomers. Journal of hazardous materials, 364, 600-607.
  More info

  Synthetic monorhamnolipids differ from biologically produced material because they are produced as single congeners, depending on the β-hydroxyalkanoic acid used during synthesis. Each congener is produced as one of four possible diastereomers resulting from two chiral centers at the carbinols of the lipid tails [(R,R), (R,S), (S,R) and (S,S)]. We compare the biodegradability (CO respirometry), acute toxicity (Microtox assay), embryo toxicity (Zebrafish assay), and cytotoxicity (xCELLigence and MTS assays) of synthetic rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-C10-C10) monorhamnolipids against biosynthesized monorhamnolipid mixtures (bio-mRL). All Rha-C10-C10 diastereomers and bio-mRL were inherently biodegradable ranging from 34 to 92% mineralized. The Microtox assay showed all Rha-C10-C10 diastereomers and bio-mRL are slightly toxic according to the US EPA ecotoxicity categories with 5 min EC values ranging from 39.6 to 87.5 μM. The zebrafish assay showed that of 22 developmental endpoints tested, only mortality was observed at 120 h post fertilization; all Rha-C10-C10 diastereomers and bio-mRL caused significant mortality at 640 μM, except the Rha-C10-C10 (R,R) which showed no developmental effects. xCELLigence and MTS showed IC values ranging from 103.4 to 191.1 μM for human lung cell line H1299 after 72 h exposure. These data provide key information regarding Rha-C10-C10 diastereomers that is pertinent when considering potential applications.
• Karnes, J. H., Sweitzer, N. K., Abraham, I., Klimecki, W. T., Sweitzer, N. K., Slack, M. K., Ramos, K. S., Klimecki, W. T., Karnes, J. H., Gharaibeh, M., Erstad, B. L., Alkhatib, N. S., & Abraham, I. (2018). Ex ante economic evaluation of genetic testing for the ARG389 beta1-adrenergic receptor polymorphism to support bucindolol treatment decisions in Stage III/IV heart failure. Expert Review of Precision Medicine and Drug Development, 3(5), 319-329. doi:10.1080/23808993.2018.1526079
  More info

  Background: Sub-analyses from the BEST trial in heart failure (HF) indicated that Arg389 homozygote patients may respond to bucindolol. Bucindolol is currently being evaluated in Arg389 genotype pa...
• Malm, S. W., Amouzougan, E. A., & Klimecki, W. T. (2018). Fetal bovine serum induces sustained, but reversible, epithelial-mesenchymal transition in the BEAS-2B cell line. Toxicology in vitro : an international journal published in association with BIBRA, 50, 383-390.
  More info

  BEAS-2B is a non-malignant, immortalized human cell line that has been used extensively as a model of lung epithelium. Despite ATCC recommendations to culture BEAS-2B in defined, serum-free media, many publications describe culturing BEAS-2B in fetal bovine serum (FBS)-containing media. The objective of this study was to define the effects of FBS on BEAS-2B cells. FBS exposure resulted in increased nuclear levels of transcription factors responsible for regulating epithelial-mesenchymal transition (EMT), increased cell invasiveness and increased anchorage-independent growth. FBS-exposed BEAS-2B cells exhibited a decrease of the epithelial markers, E-cadherin and claudin-1 at the mRNA and protein levels, along with a corresponding increase of the mesenchymal marker, vimentin, at the protein level. Fractionation studies implicated an active moiety in FBS with a molecular weight larger than 30 kD. The mesenchymal phenotype was persistent provided FBS exposure was maintained. Upon FBS removal, both epithelial and mesenchymal markers began to revert toward an epithelial phenotype. Transforming growth factor β1 (TGFβ1) exposure to BEAS-2B recapitulated some key features of FBS-induced EMT. Our data suggest that FBS-exposed BEAS-2B cells do not accurately model the epithelial phenotype. Interpretation of data from BEAS-2B should include careful consideration of the effect of culture conditions.
• , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , ., , , ., et al. (2016). Erratum.. Autophagy, 12(2), 443. doi:10.1080/15548627.2016.1147886
  More info

  Author(s): Klionsky, DJ; Abdelmohsen, K; Abe, A; Abedin, MJ; Abeliovich, H; Arozena, AA; Adachi, H; Adams, CM; Adams, PD; Adeli, K; Adhihetty, PJ; Adler, SG; Agam, G; Agarwal, R; Aghi, MK; Agnello, M; Agostinis, P; Aguilar, PV; Aguirre-Ghiso, J; Airoldi, EM; Ait-Si-Ali, S; Akematsu, T; Akporiaye, ET; Al-Rubeai, M; Albaiceta, GM; Albanese, C; Albani, D; Albert, ML; Aldudo, J; Algul, H; Alirezaei, M; Alloza, I; Almasan, A; Almonte-Beceril, M; Alnemri, ES; Alonso, C; Altan-Bonnet, N; Altieri, DC; Alvarez, S; Alvarez-Erviti, L; Alves, S; Amadoro, G; Amano, A; Amantini, C; Ambrosio, S; Amelio, I; Amer, AO; Amessou, M; Amon, A; An, Z; Anania, FA; Andersen, SU; Andley, UP; Andreadi, CK; Andrieu-Abadie, N; Anel, A; Ann, DK; Anoopkumar-Dukie, S; Antonioli, M; Aoki, H; Apostolova, N; Aquila, S; Aquilano, K; Araki, K; Arama, E; Aranda, A; Araya, J; Arcaro, A; Arias, E; Arimoto, H; Ariosa, AR; Armstrong, JL; Arnould, T; Arsov, I; Asanuma, K; Askanas, V; Asselin, E; Atarashi, R; Atherton, SS; Atkin, JD; Attardi, LD; Auberger, P; Auburger, G; Aurelian, L; Autelli, R
• Beamer, P. I., Klimecki, W. T., Loh, M., Van Horne, Y. O., Sugeng, A. J., Lothrop, N., Billheimer, D., Guerra, S., Lantz, R. C., Canales, R. A., & Martinez, F. D. (2016). Association of Children's Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media. International journal of environmental research and public health, 13(5).
  More info

  Arsenic exposure has been associated with decreased club cell secretory protein (CC16) levels in adults. Further, both arsenic exposure and decreased levels of CC16 in childhood have been associated with decreased adult lung function. Our objective was to determine if urinary CC16 levels in children are associated with arsenic concentrations in environmental media collected from their homes. Yard soil, house dust, and tap water were taken from 34 homes. Urine and toenail samples were collected from 68 children. All concentrations were natural log-transformed prior to data analysis. There were associations between urinary CC16 and arsenic concentration in soil (b = -0.43, p = 0.001, R² = 0.08), water (b = -0.22, p = 0.07, R² = 0.03), house dust (b = -0.37, p = 0.07, R² = 0.04), and dust loading (b = -0.21, p = 0.04, R² = 0.04). In multiple analyses, only the concentration of arsenic in soil was associated with urinary CC16 levels (b = -0.42, p = 0.02, R² = 0.14 (full model)) after accounting for other factors. The association between urinary CC16 and soil arsenic may suggest that localized arsenic exposure in the lungs could damage the airway epithelium and predispose children for diminished lung function. Future work to assess this possible mechanism should examine potential associations between airborne arsenic exposures, CC16 levels, lung function, and other possible confounders in children in arsenic-impacted communities.
• Beamer, P. I., Klimecki, W. T., Loh, M., Van Horne, Y. O., Sugeng, A. J., Lothrop, N., Billheimer, D., Guerra, S., Lantz, R. C., Canales, R. A., & Martinez, F. D. (2016). Response to García-Nieto et al. Comments on Beamer et al. Association of Children's Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media. Int. J. Environ. Res. Public Health 2016, 13, 521. International journal of environmental research and public health, 13(10).
  More info

  We would like to thank the editors for providing us with the opportunity to respond to the points raised by Dr. García Nieto.[...].
• Beamer, P., Beamer, P., Lu, Z., Lu, Z., Wilkinson, S. T., Wilkinson, S. T., Cox, M. L., Cox, M. L., Klimecki, W., Klimecki, W., Lothrop, N. Z., Lothrop, N. Z., Sugeng, A., Sugeng, A., Loh, M. M., & Loh, M. M. (2015). Multimedia Exposures to Arsenic and Lead for Children Near an Inactive Mine Tailings and Smelter Site. Environmental Research. doi:https://doi.org/10.1016/j.envres.2015.12.011
  More info

  Environ Res. 2016 Apr;146:331-9. doi: 10.1016/j.envres.2015.12.011. Epub 2016 Jan 21.Multimedia exposures to arsenic and lead for children near an inactive mine tailings and smelter site.Loh MM1, Sugeng A2, Lothrop N2, Klimecki W3, Cox M4, Wilkinson ST5, Lu Z6, Beamer PI2.Author information1Department of Community, Environment and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Avenue, P.O. Box 245163, Tucson, AZ 85718, USA. Electronic address: mloh@email.arizona.edu.2Department of Community, Environment and Policy, Mel and Enid Zuckerman College of Public Health, University of Arizona, 1295 N. Martin Avenue, P.O. Box 245163, Tucson, AZ 85718, USA.3Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, P.O. Box 210207, Tucson, AZ 85724, USA.4Hospital Medicine and Outreach, Department of Pediatrics, Diamond Children's Medical Center, The University of Arizona, 1501 N. Campbell Ave. Tucson, AZ 85724, USA.5Superfund Research Program, The University of Arizona, 1110 E. South Campus Dr., Tucson, AZ 85721, USA.6BIO5 Institute, The University of Arizona, 1657 E. Mabel St., Tucson, AZ 85721, USA.AbstractChildren living near contaminated mining waste areas may have high exposures to metals from the environment. This study investigates whether exposure to arsenic and lead is higher in children in a community near a legacy mine and smelter site in Arizona compared to children in other parts of the United States and the relationship of that exposure to the site. Arsenic and lead were measured in residential soil, house dust, tap water, urine, and toenail samples from 70 children in 34 households up to 7 miles from the site. Soil and house dust were sieved, digested, and analyzed via ICP-MS. Tap water and urine were analyzed without digestion, while toenails were washed, digested and analyzed. Blood lead was analyzed by an independent, certified laboratory. Spearman correlation coefficients were calculated between each environmental media and urine and toenails for arsenic and lead. Geometric mean arsenic (standard deviation) concentrations for each matrix were: 22.1 (2.59) ppm and 12.4 (2.27)ppm for soil and house dust (
• Beamer, P., Klimecki, W., Loh, M., Van Horne, Y. O., Sugeng, A., Lothrop, N., Billheimer, D., Guerra, S., Lantz, R. C., & Martinez, F. (2016). Association of Children’s Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media. International Journal of Environmental Research and Public Health, 13(5), E521. doi:10.3390/ijerph13050521
• Beamer, P., Loh, M. M., Klimecki, W., Ornelas Van Horne, Y., Sugeng, A. J., Lothrop, N. Z., Billheimer, D. D., Guerra, S., Lantz, R. C., Canales, R. A., & Martinez, F. (2016). Association of children's urinary CC16 levels with arsenic concentrations in multiple environmental media. International Journal of Environmental Research and Public Health.
• Klimentidis, Y. C., Bea, J. W., Thompson, P., Klimecki, W. T., Hu, C., Wu, G., Nicholas, J. S., Ryckman, K. K., & Chen, Z. (2016). Genetic Variant in ACVR2B Is Associated with Lean Mass. Medicine and science in sports and exercise, 48(7), 1270-5.
  More info

  Low lean mass (LM) is a risk factor for chronic disease, a major cause of disability and diminished quality of life, and is a heritable trait. However, relatively few specific genetic factors have been identified as potentially influencing this trait.
• Klionsky, D. J., Abdelmohsen, K., Abe, A., Abedin, M. J., Abeliovich, H., Acevedo Arozena, A., Adachi, H., Adams, C. M., Adams, P. D., Adeli, K., Adhihetty, P. J., Adler, S. G., Agam, G., Agarwal, R., Aghi, M. K., Agnello, M., Agostinis, P., Aguilar, P. V., Aguirre-Ghiso, J., , Airoldi, E. M., et al. (2016). Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition). Autophagy, 12(1), 1-222.
• Loh, M. M., Sugeng, A., Lothrop, N., Klimecki, W., Cox, M., Wilkinson, S. T., Lu, Z., & Beamer, P. I. (2016). Multimedia exposures to arsenic and lead for children near an inactive mine tailings and smelter site. Environmental research, 146, 331-9.
  More info

  Children living near contaminated mining waste areas may have high exposures to metals from the environment. This study investigates whether exposure to arsenic and lead is higher in children in a community near a legacy mine and smelter site in Arizona compared to children in other parts of the United States and the relationship of that exposure to the site. Arsenic and lead were measured in residential soil, house dust, tap water, urine, and toenail samples from 70 children in 34 households up to 7 miles from the site. Soil and house dust were sieved, digested, and analyzed via ICP-MS. Tap water and urine were analyzed without digestion, while toenails were washed, digested and analyzed. Blood lead was analyzed by an independent, certified laboratory. Spearman correlation coefficients were calculated between each environmental media and urine and toenails for arsenic and lead. Geometric mean arsenic (standard deviation) concentrations for each matrix were: 22.1 (2.59) ppm and 12.4 (2.27)ppm for soil and house dust (
• Lothrop, N., Wilkinson, S. T., Verhougstraete, M., Sugeng, A., Loh, M. M., Klimecki, W., & Beamer, P. I. (2016). Home Water Treatment Habits and Effectiveness in a Rural Arizona Community. Water, 7(3), 1217-1231.
  More info

  Drinking water quality in the United States (US) is among the safest in the world. However, many residents, often in rural areas, rely on unregulated private wells or small municipal utilities for water needs. These utilities may violate the Safe Drinking Water Act contaminant guidelines, often because they lack the required financial resources. Residents may use alternative water sources or install a home water treatment system. Despite increased home water treatment adoption, few studies have examined their use and effectiveness in the US. Our study addresses this knowledge gap by examining home water treatment in a rural Arizona community. Water samples were analyzed for metal(loid)s, and home treatment and demographic data were recorded in 31 homes. Approximately 42% of homes treated their water. Independent of source water quality, residents with higher income (OR = 1.25; 95%CI (1.00 - 1.64)) and education levels (OR = 1.49; 95%CI (1.12 - 2.12)) were more likely to treat their water. Some contaminant concentrations were effectively reduced with treatment, while some were not. We conclude that increased educational outreach on contaminant testing and treatment, especially to rural areas with endemic water contamination, would result in a greater public health impact while reducing rural health disparities.
• Ramirez-Andreotta, M. D., Lothrop, N., Wilkinson, S. T., Root, R. A., Artiola, J. F., Klimecki, W., & Loh, M. (2016). Analyzing Patterns of Community Interest at a Legacy Mining Waste Site to Assess and Inform Environmental Health Literacy Efforts. Journal of environmental studies and sciences, 6(3), 543-555.
  More info

  Understanding a community's concerns and informational needs is crucial to conducting and improving environmental health research and literacy initiatives. We hypothesized that analysis of community inquiries over time at a legacy mining site would be an effective method for assessing environmental health literacy efforts and determining whether community concerns were thoroughly addressed. Through a qualitative analysis, we determined community concerns at the time of being listed as a Superfund site. We analyzed how community concerns changed from this starting point over the subsequent years, and whether: 1) communication materials produced by the USEPA and other media were aligned with community concerns; and 2) these changes demonstrated a progression of the community's understanding resulting from community involvement and engaged research efforts. We observed that when the Superfund site was first listed, community members were most concerned with USEPA management, remediation, site-specific issues, health effects, and environmental monitoring efforts related to air/dust and water. Over the next five years, community inquiries shifted significantly to include exposure assessment and reduction methods and issues unrelated to the site, particularly the local public water supply and home water treatment systems. Such documentation of community inquiries over time at contaminated sites is a novel method to assess environmental health literacy efforts and determine whether community concerns were thoroughly addressed.
• Lothrop, N. Z., Wilkinson, S. T., Verhougstraete, M., Sugeng, A., Loh, M. M., Klimecki, W., & Beamer, P. I. (2015). Home Water Treatment Habits and Effectiveness in a Rural Arizona Community. Water, 7(3), 1217-1231.
• Ramirez, M. D., Lothrop, N. Z., Wilkinson, S. T., Root, R., Artiola, J. F., Klimecki, W., Loh, M., Ramirez, M. D., Lothrop, N. Z., Wilkinson, S. T., Root, R., Artiola, J. F., Klimecki, W., & Loh, M. (2015). Analyzing patterns of community interest at a legacy mining waste site to assess and inform environmental health literacy efforts. Journal of Environmental Studies and Sciences. doi:10.1007/s13412-015-0297-x
• Ramirez-Andreotta, M. D., Lothrop, N. Z., Wilkinson, S. T., Root, R. A., Artiola, J. F., Klimecki, W., & Loh, M. M. (2015). Analyzing Patterns of Community Interest at a Legacy Mining Waste Site to Assess and Inform Environmental Health Literacy Efforts. Environmental Studies and Sciences.
• Zhao, F., & Klimecki, W. T. (2015). Culture conditions profoundly impact phenotype in BEAS-2B, a human pulmonary epithelial model. Journal of applied toxicology : JAT, 35(8), 945-51.
  More info

  BEAS-2B, an immortalized, human lung epithelial cell line, has been used to model pulmonary epithelial function for over 30 years. The BEAS-2B phenotype can be modulated by culture conditions that include the presence or absence of fetal bovine serum (FBS). The popularity of BEAS-2B as a model of arsenic toxicology, and the common use of BEAS-2B cultured both with and without FBS, led us to investigate the impact of FBS on BEAS-2B in the context of arsenic toxicology. Comparison of genome-wide gene expression in BEAS-2B cultured with or without FBS revealed altered expression in several biological pathways, including those related to carcinogenesis and energy metabolism. Real-time measurements of oxygen consumption and glycolysis in BEAS-2B demonstrated that FBS culture conditions were associated with a 1.4-fold increase in total glycolytic capacity, a 1.9-fold increase in basal respiration, a 2.0-fold increase in oxygen consumed for ATP production and a 2.8-fold increase in maximal respiration, compared with BEAS-2B cultured without FBS. Comparisons of the transcriptome changes in BEAS-2B resulting from FBS exposure to the transcriptome changes resulting from exposure to 1 μM sodium arsenite revealed that mRNA levels of 43% of the arsenite-modulated genes were also modulated by FBS. Cytotoxicity studies revealed that BEAS-2B cells exposed to 5% FBS for 8 weeks were almost 5 times more sensitive to arsenite cytotoxicity than non-FBS-exposed BEAS-2B cells. Phenotype changes induced in BEAS-2B by FBS suggest that culture conditions should be carefully considered when using BEAS-2B as an experimental model of arsenic toxicity.
• Beamer, P. -., Sugeng, A. J., Kelly, M. D., Lothrop, N., Klimecki, W. -., Wilkinson, S. T., Loh, M. M., Beamer, P. -., Sugeng, A. J., Kelly, M. D., Lothrop, N., Klimecki, W. -., Wilkinson, S. T., & Loh, M. M. (2014). Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings. Environmental Science Processes and Impacts, 16(6), 1157-1536.
• Beamer, P. I., Sugeng, A. J., Kelly, M. D., Lothrop, N., Klimecki, W., Wilkinson, S. T., & Loh, M. (2014). Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings. Environmental science. Processes & impacts, 16(6), 1275-81.
  More info

  Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p < 0.05), whose primary source in indoor air is resuspended soil from outdoors. In the second rural community, our estimated metal concentrations in air were comparable to active air sampling measurements taken previously. This passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites.
• Beamer, P. I., Sugeng, A., Kelly, M. D., Lothrop, N. Z., Klimecki, W., Wilkinson, S. T., & Loh, M. M. (2014). Use of dust fall filters as passive samplers for concentrations in air for communities near contaminated mine tailings. Environmental science--processes & impacts, 16(6), 1157-1536.
• Gandolfi, A. J., Klimecki, W. T., Lopez-carrillo*, L., Lopez-carrillo, L., Klimecki, W. T., Herrera, A. V., Hernandez-ramirez, R. U., Gandolfi, A. J., & Cebrian, M. E. (2014). Nutrient-Gene Interaction in Arsenic Metabolism. ISEE Conference Abstracts, 2014(1), 2026. doi:10.1289/isee.2014.p3-767
  More info

  Arsenic (As) naturally occurs in water and its long-term exposure is linked with many health problems, including skin lesions and cancer. Nutrient intake and genetic polymorphisms involved in one-c...
• Kripke, D. F., Klimecki, W. T., Nievergelt, C. M., Rex, K. M., Murray, S. S., Shekhtman, T., Tranah, G. J., Loving, R. T., Lee, H., Rhee, M. K., Shadan, F. F., Poceta, J. S., Jamil, S. M., Kline, L. E., & Kelsoe, J. R. (2014). Circadian polymorphisms in night owls, in bipolars, and in non-24-hour sleep cycles. Psychiatry investigation, 11(4), 345-62.
  More info

  People called night owls habitually have late bedtimes and late times of arising, sometimes suffering a heritable circadian disturbance called delayed sleep phase syndrome (DSPS). Those with DSPS, those with more severe progressively-late non-24-hour sleep-wake cycles, and those with bipolar disorder may share genetic tendencies for slowed or delayed circadian cycles. We searched for polymorphisms associated with DSPS in a case-control study of DSPS research participants and a separate study of Sleep Center patients undergoing polysomnography. In 45 participants, we resequenced portions of 15 circadian genes to identify unknown polymorphisms that might be associated with DSPS, non-24-hour rhythms, or bipolar comorbidities. We then genotyped single nucleotide polymorphisms (SNPs) in both larger samples, using Illumina Golden Gate assays. Associations of SNPs with the DSPS phenotype and with the morningness-eveningness parametric phenotype were computed for both samples, then combined for meta-analyses. Delayed sleep and "eveningness" were inversely associated with loci in circadian genes NFIL3 (rs2482705) and RORC (rs3828057). A group of haplotypes overlapping BHLHE40 was associated with non-24-hour sleep-wake cycles, and less robustly, with delayed sleep and bipolar disorder (e.g., rs34883305, rs34870629, rs74439275, and rs3750275 were associated with n=37, p=4.58E-09, Bonferroni p=2.95E-06). Bright light and melatonin can palliate circadian disorders, and genetics may clarify the underlying circadian photoperiodic mechanisms. After further replication and identification of the causal polymorphisms, these findings may point to future treatments for DSPS, non-24-hour rhythms, and possibly bipolar disorder or depression.
• Lake, A. D., Novak, P., Hardwick, R. N., Flores-Keown, B., Zhao, F., Klimecki, W. T., & Cherrington, N. J. (2014). The adaptive endoplasmic reticulum stress response to lipotoxicity in progressive human nonalcoholic fatty liver disease. Toxicological sciences : an official journal of the Society of Toxicology, 137(1), 26-35.
  More info

  Nonalcoholic fatty liver disease (NAFLD) may progress from simple steatosis to severe, nonalcoholic steatohepatitis (NASH) in 7%-14% of the U.S. population through a second "hit" in the form of increased oxidative stress and inflammation. Endoplasmic reticulum (ER) stress signaling and the unfolded protein response (UPR) are triggered when high levels of lipids and misfolded proteins alter ER homeostasis creating a lipotoxic environment within NAFLD livers. The objective of this study was to determine the coordinate regulation of ER stress-associated genes in the progressive stages of human NAFLD. Human liver samples categorized as normal, steatosis, NASH (Fatty), and NASH (Not Fatty) were analyzed by individual Affymetrix GeneChip Human 1.0 ST microarrays, immunoblots, and immunohistochemistry. A gene set enrichment analysis was performed on autophagy, apoptosis, lipogenesis, and ER stress/UPR gene categories. An enrichment of downregulated genes in the ER stress-associated lipogenesis and ER stress/UPR gene categories was observed in NASH. Conversely, an enrichment of upregulated ER stress-associated genes for autophagy and apoptosis gene categories was observed in NASH. Protein expression of the adaptive liver response protein STC2 and the transcription factor X-box binding protein 1 spliced (XBP-1s) were significantly elevated among NASH samples, whereas other downstream ER stress proteins including CHOP, ATF4, and phosphorylated JNK and eIF2α were not significantly changed in disease progression. Increased nuclear accumulation of total XBP-1 protein was observed in steatosis and NASH livers. The findings reveal the presence of a coordinated, adaptive transcriptional response to hepatic ER stress in human NAFLD.
• Zhao, F., Malm, S. W., Hinchman, A. N., Li, H., Beeks, C. G., & Klimecki, W. T. (2014). Arsenite-induced pseudo-hypoxia results in loss of anchorage-dependent growth in BEAS-2B pulmonary epithelial cells. PloS one, 9(12), e114549.
  More info

  Epidemiology studies have established a strong link between lung cancer and arsenic exposure. Currently, the role of disturbed cellular energy metabolism in carcinogenesis is a focus of scientific interest. Hypoxia inducible factor-1 alpha (HIF-1A) is a key regulator of energy metabolism, and it has been found to accumulate during arsenite exposure under oxygen-replete conditions. We modeled arsenic-exposed human pulmonary epithelial cells in vitro with BEAS-2B, a non-malignant lung epithelial cell line. Constant exposure to 1 µM arsenite (As) resulted in the early loss of anchorage-dependent growth, measured by soft agar colony formation, beginning at 6 weeks of exposure. This arsenite exposure resulted in HIF-1A accumulation and increased glycolysis, similar to the physiologic response to hypoxia, but in this case under oxygen-replete conditions. This "pseudo-hypoxia" response was necessary for the maximal acquisition of anchorage-independent growth in arsenite-exposed BEAS-2B. The HIF-1A accumulation and induction in glycolysis was sustained throughout a 52 week course of arsenite exposure in BEAS-2B. There was a time-dependent increase in anchorage-independent growth during the exposure to arsenite. When HIF-1A expression was stably suppressed, arsenite-induced glycolysis was abrogated, and the anchorage-independent growth was reduced. These findings establish that arsenite exerts a hypoxia-mimetic effect, which plays an important role in the subsequent gain of malignancy-associated phenotypes.
• Beamer, P., Nathan, L., Melissa, C., Walter, K., Miranda, L., T, W. S., Paloma, B., Loh, M., Klimecki, W., Cox, M., Anastasia, S., Wilkinson, S. T., Sugeng, A., Lothrop, N., Loh, M., Klimecki, W. T., Cox, M., & Beamer, P. I. (2013). Airborne metal concentrations measured using passive samplers in a community near contaminated mine tailings. ISEE Conference Abstracts, 2013(1), 4721. doi:10.1289/isee.2013.o-3-16-02
  More info

  Background: Many communities are located near contaminated mine tailings and smelter ash. Multiple air samples are necessary to assess the extent of exposures and factors contributing to exposures ...
• Díaz-Villaseñor, A., Cruz, L., Cebrián, A., Hernández-Ramírez, R. U., Hiriart, M., García-Vargas, G., Bassol, S., Sordo, M., Gandolfi, A. J., Klimecki, W. T., López-Carillo, L., Cebrián, M. E., & Ostrosky-Wegman, P. (2013). Arsenic Exposure and Calpain-10 Polymorphisms Impair the Function of Pancreatic Beta-Cells in Humans: A Pilot Study of Risk Factors for T2DM. PLoS ONE, 8(1).
  More info

  PMID: 23349674;PMCID: PMC3551951;Abstract: The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs) in the calpain-10 gene (CAPN-10), which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs) through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function) and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2) in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function. © 2013 Díaz- Villaseñor et al.
• Díaz-Villaseñor, A., Cruz, L., Cebrián, A., Hernández-Ramírez, R. U., Hiriart, M., García-Vargas, G., Bassol, S., Sordo, M., Gandolfi, A. J., Klimecki, W. T., López-Carillo, L., Cebrián, M. E., & Ostrosky-Wegman, P. (2013). Arsenic exposure and calpain-10 polymorphisms impair the function of pancreatic beta-cells in humans: a pilot study of risk factors for T2DM. PloS one, 8(1), e51642.
  More info

  The incidence of type 2 diabetes mellitus (T2DM) is increasing worldwide and diverse environmental and genetic risk factors are well recognized. Single nucleotide polymorphisms (SNPs) in the calpain-10 gene (CAPN-10), which encodes a protein involved in the secretion and action of insulin, and chronic exposure to inorganic arsenic (iAs) through drinking water have been independently associated with an increase in the risk for T2DM. In the present work we evaluated if CAPN-10 SNPs and iAs exposure jointly contribute to the outcome of T2DM. Insulin secretion (beta-cell function) and insulin sensitivity were evaluated indirectly through validated indexes (HOMA2) in subjects with and without T2DM who have been exposed to a gradient of iAs in their drinking water in northern Mexico. The results were analyzed taking into account the presence of the risk factor SNPs SNP-43 and -44 in CAPN-10. Subjects with T2DM had significantly lower beta-cell function and insulin sensitivity. An inverse association was found between beta-cell function and iAs exposure, the association being more pronounced in subjects with T2DM. Subjects without T2DM who were carriers of the at-risk genotype SNP-43 or -44, also had significantly lower beta-cell function. The association of SNP-43 with beta-cell function was dependent on iAs exposure, age, gender and BMI, whereas the association with SNP-44 was independent of all of these factors. Chronic exposure to iAs seems to be a risk factor for T2DM in humans through the reduction of beta-cell function, with an enhanced effect seen in the presence of the at-risk genotype of SNP-43 in CAPN-10. Carriers of CAPN-10 SNP-44 have also shown reduced beta-cell function.
• Klimecki, W., Zhao, F., Severson, P., Pacheco, S., Futscher, B. W., & Klimecki, W. -. (2013). Arsenic exposure induces the Warburg effect in cultured human cells. Toxicology and applied pharmacology, 271(1).
  More info

  Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases.
• Lothrop, N., Cox, M., Klimecki, W. T., Wilkinson, S. T., Sugeng, A., Lothrop, N., Loh, M., Klimecki, W. T., Cox, M., & Beamer, P. I. (2013). Comparison of Inter-Home and Intra-Homes Variance of Arsenic in Children’s Urine for Households Near a Hazardous Waste Site. ISEE Conference Abstracts, 2013(1), 5196. doi:10.1289/isee.2013.p-1-10-10
  More info

  Background:Children living near hazardous waste sites may be at an increased risk for exposure to environmental contaminants, such as metals. However, children in the same home and between differen...
• Lothrop, N., Cox, M., Klimecki, W. T., Wilkinson, S. T., Sugeng, A., Lothrop, N., Loh, M., Klimecki, W. T., Cox, M., & Beamer, P. I. (2013). Exposure to Metals in Environmental Media Near a Mine Tailings Site. ISEE Conference Abstracts, 2013(1), 4746. doi:10.1289/isee.2013.p-1-10-13
• Bolt, A. M., & Klimecki, W. T. (2012). Autophagy in toxicology: Self-consumption in times of stress and plenty. Journal of Applied Toxicology, 32(7), 465-479.
  More info

  PMID: 22334383;PMCID: PMC3572937;Abstract: Autophagy is a critical cellular process orchestrating the lysosomal degradation of cellular components in order to maintain cellular homeostasis and respond to cellular stress. A growing research effort over the last decade has proven autophagy to be essential for constitutive protein and organelle turnover, for embryonic/neonatal survival and for cell survival during conditions of environmental stress. Emphasizing its biological importance, dysfunctional autophagy contributes to a diverse set of human diseases. Cellular stress induced by xenobiotic exposure typifies environmental stress, and can result in the induction of autophagy as a cytoprotective mechanism. An increasing number of xenobiotics are notable for their ability to modulate the induction or the rate of autophagy. The role of autophagy in normal cellular homeostasis, the intricate relationship between cellular stress and the induction of autophagy, and the identification of specific xenobiotics capable of modulating autophagy, point to the importance of the autophagic process in toxicology. This review will summarize the importance of autophagy and its role in cellular response to stress, including examples in which consideration of autophagy has contributed to a more complete understanding of toxicant-perturbed systems. © 2012 John Wiley & Sons, Ltd.
• Bolt, A. M., Zhao, F., Pacheco, S., & Klimecki, W. T. (2012). Arsenite-induced autophagy is associated with proteotoxicity in human lymphoblastoid cells. Toxicology and Applied Pharmacology, 264(2), 255-261.
  More info

  PMID: 22959463;PMCID: PMC3462290;Abstract: Epidemiological studies of arsenic-exposed populations have provided evidence that arsenic exposure in humans is associated with immunosuppression. Previously, we have reported that arsenite-induced toxicity is associated with the induction of autophagy in human lymphoblastoid cell lines (LCL). Autophagy is a cellular process that functions in the degradation of damaged cellular components, including protein aggregates formed by misfolded or damaged proteins. Accumulation of misfolded or damaged proteins in the endoplasmic reticulum (ER) lumen causes ER stress and activates the unfolded protein response (UPR). In an effort to investigate the mechanism of autophagy induction by arsenite in the LCL model, we examined the potential contribution of ER stress and activation of the UPR. LCL exposed to sodium arsenite for 8-days induced expression of UPR-activated genes, including CHOP and GRP78, at the RNA and the protein level. Evidence for activation of the three arms of the UPR was observed. The arsenite-induced activation of the UPR was associated with an accumulation of protein aggregates containing p62 and LC3, proteins with established roles in the sequestration and autophagic clearance of protein aggregates. Taken together, these data provide evidence that arsenite-induced autophagy is associated with the generation of ER stress, activation of the UPR, and formation of protein aggregates that may be targeted to the lysosome for degradation. © 2012 Elsevier Inc.
• Canet, M. J., Hardwick, R. N., Lake, A. D., Kopplin, M. J., Scheffer, G. L., Klimecki, W. T., Gandolfi, A. J., & Cherrington, N. J. (2012). Altered arsenic disposition in experimental nonalcoholic fatty liver disease. Drug metabolism and disposition: the biological fate of chemicals, 40(9), 1817-24.
  More info

  Nonalcoholic fatty liver disease (NAFLD) is represented by a spectrum of liver pathologies ranging from simple steatosis to nonalcoholic steatohepatitis (NASH). Liver damage sustained in the progressive stages of NAFLD may alter the ability of the liver to properly metabolize and eliminate xenobiotics. The purpose of the current study was to determine whether NAFLD alters the disposition of the environmental toxicant arsenic. C57BL/6 mice were fed either a high-fat or a methionine-choline-deficient diet to model simple steatosis and NASH, respectively. At the conclusion of the dietary regimen, all mice were given a single oral dose of either sodium arsenate or arsenic trioxide. Mice with NASH excreted significantly higher levels of total arsenic in urine (24 h) compared with controls. Total arsenic in the liver and kidneys of NASH mice was not altered; however, NASH liver retained significantly higher levels of the monomethyl arsenic metabolite, whereas dimethyl arsenic was retained significantly less in the kidneys of NASH mice. NASH mice had significantly higher levels of the more toxic trivalent form in their urine, whereas the pentavalent form was preferentially retained in the liver of NASH mice. Moreover, hepatic protein expression of the arsenic biotransformation enzyme arsenic (3+ oxidation state) methyltransferase was not altered in NASH animals, whereas protein expression of the membrane transporter multidrug resistance-associated protein 1 was increased, implicating cellular transport rather than biotransformation as a possible mechanism. These results suggest that NASH alters the disposition of arsenical species, which may have significant implications on the overall toxicity associated with arsenic in NASH.
• Klimecki, W., Bolt, A. M., & Klimecki, W. -. (2012). Autophagy in toxicology: self-consumption in times of stress and plenty. Journal of applied toxicology : JAT, 32(7).
  More info

  Autophagy is a critical cellular process orchestrating the lysosomal degradation of cellular components in order to maintain cellular homeostasis and respond to cellular stress. A growing research effort over the last decade has proven autophagy to be essential for constitutive protein and organelle turnover, for embryonic/neonatal survival and for cell survival during conditions of environmental stress. Emphasizing its biological importance, dysfunctional autophagy contributes to a diverse set of human diseases. Cellular stress induced by xenobiotic exposure typifies environmental stress, and can result in the induction of autophagy as a cytoprotective mechanism. An increasing number of xenobiotics are notable for their ability to modulate the induction or the rate of autophagy. The role of autophagy in normal cellular homeostasis, the intricate relationship between cellular stress and the induction of autophagy, and the identification of specific xenobiotics capable of modulating autophagy, point to the importance of the autophagic process in toxicology. This review will summarize the importance of autophagy and its role in cellular response to stress, including examples in which consideration of autophagy has contributed to a more complete understanding of toxicant-perturbed systems.
• Klimecki, W., Bolt, A. M., Zhao, F., Pacheco, S., & Klimecki, W. -. (2012). Arsenite-induced autophagy is associated with proteotoxicity in human lymphoblastoid cells. Toxicology and applied pharmacology, 264(2).
  More info

  Epidemiological studies of arsenic-exposed populations have provided evidence that arsenic exposure in humans is associated with immunosuppression. Previously, we have reported that arsenite-induced toxicity is associated with the induction of autophagy in human lymphoblastoid cell lines (LCL). Autophagy is a cellular process that functions in the degradation of damaged cellular components, including protein aggregates formed by misfolded or damaged proteins. Accumulation of misfolded or damaged proteins in the endoplasmic reticulum (ER) lumen causes ER stress and activates the unfolded protein response (UPR). In an effort to investigate the mechanism of autophagy induction by arsenite in the LCL model, we examined the potential contribution of ER stress and activation of the UPR. LCL exposed to sodium arsenite for 8-days induced expression of UPR-activated genes, including CHOP and GRP78, at the RNA and the protein level. Evidence for activation of the three arms of the UPR was observed. The arsenite-induced activation of the UPR was associated with an accumulation of protein aggregates containing p62 and LC3, proteins with established roles in the sequestration and autophagic clearance of protein aggregates. Taken together, these data provide evidence that arsenite-induced autophagy is associated with the generation of ER stress, activation of the UPR, and formation of protein aggregates that may be targeted to the lysosome for degradation.
• Klimecki, W., Gomez-Rubio, P., Klimentidis, Y. C., Cantu-Soto, E., Meza-Montenegro, M. M., Billheimer, D., Lu, Z., Chen, Z., & Klimecki, W. -. (2012). Indigenous American ancestry is associated with arsenic methylation efficiency in an admixed population of northwest Mexico. Journal of toxicology and environmental health. Part A, 75(1).
  More info

  Many studies provide evidence relating lower human arsenic (As) methylation efficiency, represented by high percent urinary monomethylarsonic acid (MMA(V)), with several As-induced diseases, possibly due to the fact that MMA(V) serves as a proxy for MMA(III), the most toxic As metabolite. Some epidemiological studies suggested that indigenous Americans (AME) methylate As more efficiently; however, data supporting this have been equivocal. The aim of this study was to characterize the association between AME ancestry and As methylation efficiency using a panel of ancestry informative genetic markers to determine individual ancestry proportions in an admixed population (composed of two or more isolated ancestral populations) of 746 individuals environmentally exposed to As in northwest Mexico. Total urinary As (TAs) mean and range were 170.4 and 2.3-1053.5 μg/L, while percent AME (%AME) mean and range were 72.4 and 23-100. Adjusted (gender, age, AS3MT 7388/M287T haplotypes, body mass index [BMI], and TAs) multiple regression model showed that higher AME ancestry is significantly associated with lower percentage of urinary As excreted as MMA(V) (%uMMA) in this population (p < .01). Data also demonstrated a significant interaction between BMI and gender, indicating negative association between BMI and %uMMA, stronger in women than men (p < .01). Moreover, age and the AS3MT variants 7388 (intronic) and M287T (nonsynonymous) were also significantly associated with As methylation efficiency (p < .01). This study highlights the importance of BMI and indigenous American ancestry in some of the observed variability in As methylation efficiency, underscoring the need to be considered in epidemiology studies, particularly those carried out in admixed populations.
• Klionsky, D. J., Abdalla, F. C., Abeliovich, H., Abraham, R. T., Acevedo-Arozena, A., Adeli, K., Agholme, L., Agnello, M., Agostinis, P., Aguirre-Ghiso, J. A., Ahn, H. J., Ait-Mohamed, O., Ait-Si-Ali, S., Akematsu, T., Akira, S., Al-Younes, H. M., Al-Zeer, M. A., Albert, M. L., Albin, R. L., , Alegre-Abarrategui, J., et al. (2012). Guidelines for the use and interpretation of assays for monitoring autophagy. Autophagy, 8(4), 445-544.
  More info

  Abstract: In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field. © 2012 Landes Bioscience.
• Meza-Montenegro, M. M., Gandolfi, A. J., Santana-Alcántar, M. E., Klimecki, W. T., Aguilar-Apodaca, M. G., Del Río-Salas, R., De la O-Villanueva, M., Gómez-Alvarez, A., Mendivil-Quijada, H., Valencia, M., & Meza-Figueroa, D. (2012). Metals in residential soils and cumulative risk assessment in Yaqui and Mayo agricultural valleys, northern Mexico. The Science of the total environment, 433, 472-81.
  More info

  This investigation examines the extent of soil metal pollution associated with the Green Revolution, relative to agricultural activities and associated risks to health in the most important agricultural region of Mexico. Metal contents in bulk soil samples are commonly used to assess contamination, and metal accumulations in soils are usually assumed to increase with decreasing particle size. This study profiled the spatial distribution of metals (Ni, Cr, Pb, Cu, Fe, Cd, V, Hg, Co, P, Se, and Mn) in bulk soil and fine-grained fractions (soil-derived dust) from 22 towns and cities. The contamination of soil was assessed through the use of a geoaccumulation index (Igeo) and pollution index (PI). The results of this study indicated that a number of towns and cities are moderately to highly polluted by soil containing Be, Co, Hg, P, S, V, Zn, Se, Cr, and Pb in both size fractions (coarse and fine). Hazard index in fine fraction (HI(children)=2.1) shows that risk assessment based on Co, Mn, V, and Ni spatially related to power plants, have the potential to pose health risks to local residents, especially children. This study shows that risk assessment based on metal content in bulk soil could be overestimated when compared to fine-grained fraction. Our results provide important information that could be valuable in establishing risk assessment associated with residential soils within agricultural areas, where children can ingest and inhale dust.
• Meza-Montenegro, M. M., Gandolfi, A. J., Santana-Alcántar, M. E., Klimecki, W. T., Aguilar-Apodaca, M. G., Río-Salas, R. D., De, M., Gómez-Alvarez, A., Mendivil-Quijada, H., Valencia, M., & Meza-Figueroa, D. (2012). Metals in residential soils and cumulative risk assessment in Yaqui and Mayo agricultural valleys, northern Mexico. Science of the Total Environment, 433, 472-481.
  More info

  PMID: 22820616;Abstract: This investigation examines the extent of soil metal pollution associated with the Green Revolution, relative to agricultural activities and associated risks to health in the most important agricultural region of Mexico. Metal contents in bulk soil samples are commonly used to assess contamination, and metal accumulations in soils are usually assumed to increase with decreasing particle size. This study profiled the spatial distribution of metals (Ni, Cr, Pb, Cu, Fe, Cd, V, Hg, Co, P, Se, and Mn) in bulk soil and fine-grained fractions (soil-derived dust) from 22 towns and cities. The contamination of soil was assessed through the use of a geoaccumulation index (Igeo) and pollution index (PI). The results of this study indicated that a number of towns and cities are moderately to highly polluted by soil containing Be, Co, Hg, P, S, V, Zn, Se, Cr, and Pb in both size fractions (coarse and fine). Hazard index in fine fraction (HIchildren=2.1) shows that risk assessment based on Co, Mn, V, and Ni spatially related to power plants, have the potential to pose health risks to local residents, especially children. This study shows that risk assessment based on metal content in bulk soil could be overestimated when compared to fine-grained fraction. Our results provide important information that could be valuable in establishing risk assessment associated with residential soils within agricultural areas, where children can ingest and inhale dust. © 2012 Elsevier B.V.
• Klimecki, W., Gomez-Rubio, P., Roberge, J., Arendell, L., Harris, R. B., O'Rourke, M. K., Chen, Z., Cantu-Soto, E., Meza-Montenegro, M. M., Billheimer, D., Lu, Z., & Klimecki, W. -. (2011). Association between body mass index and arsenic methylation efficiency in adult women from southwest U.S. and northwest Mexico. Toxicology and applied pharmacology, 252(2).
  More info

  Human arsenic methylation efficiency has been consistently associated with arsenic-induced disease risk. Interindividual variation in arsenic methylation profiles is commonly observed in exposed populations, and great effort has been put into the study of potential determinants of this variability. Among the factors that have been evaluated, body mass index (BMI) has not been consistently associated with arsenic methylation efficiency; however, an underrepresentation of the upper BMI distribution was commonly observed in these studies. This study investigated potential factors contributing to variations in the metabolism of arsenic, with specific interest in the effect of BMI where more than half of the population was overweight or obese. We studied 624 adult women exposed to arsenic in drinking water from three independent populations. Multivariate regression models showed that higher BMI, arsenic (+3 oxidation state) methyltransferase (AS3MT) genetic variant 7388, and higher total urinary arsenic were significantly associated with low percentage of urinary arsenic excreted as monomethylarsonic acid (%uMMA) or high ratio between urinary dimethylarsinic acid and uMMA (uDMA/uMMA), while AS3MT genetic variant M287T was associated with high %uMMA and low uDMA/uMMA. The association between BMI and arsenic methylation efficiency was also evident in each of the three populations when studied separately. This strong association observed between high BMI and low %uMMA and high uDMA/uMMA underscores the importance of BMI as a potential arsenic-associated disease risk factor, and should be carefully considered in future studies associating human arsenic metabolism and toxicity.
• Lake, A. D., Novak, P., Fisher, C. D., Jackson, J. P., Hardwick, R. N., Billheimer, D. D., Klimecki, W. T., & Cherrington, N. J. (2011). Analysis of global and absorption, distribution, metabolism, and elimination gene expression in the progressive stages of human nonalcoholic fatty liver disease. Drug metabolism and disposition: the biological fate of chemicals, 39(10), 1954-60.
  More info

  Nonalcoholic fatty liver disease (NAFLD) is characterized by a series of pathological changes that range from simple fatty liver to nonalcoholic steatohepatitis (NASH). The objective of this study is to describe changes in global gene expression associated with the progression of human NAFLD. This study is focused on the expression levels of genes responsible for the absorption, distribution, metabolism, and elimination (ADME) of drugs. Differential gene expression between three clinically defined pathological groups-normal, steatosis, and NASH-was analyzed. Genome-wide mRNA levels in samples of human liver tissue were assayed with Affymetrix GeneChip Human 1.0ST arrays. A total of 11,633 genes exhibited altered expression out of 33,252 genes at a 5% false discovery rate. Most gene expression changes occurred in the progression from steatosis to NASH. Principal component analysis revealed that hepatic disease status was the major determinant of differential ADME gene expression rather than age or sex of sample donors. Among the 515 drug transporters and 258 drug-metabolizing enzymes (DMEs) examined, uptake transporters but not efflux transporters or DMEs were significantly over-represented in the number of genes down-regulated. These results suggest that uptake transporter genes are coordinately targeted for down-regulation at the global level during the pathological development of NASH and that these patients may have decreased drug uptake capacity. This coordinated regulation of uptake transporter genes is indicative of a hepatoprotective mechanism acting to prevent accumulation of toxic intermediates in disease-compromised hepatocytes.
• Mostecki, J., Cassel, S. L., Klimecki, W. T., Stern, D. A., Knisz, J., Iwashita, S., Graves, P., Miller, R. L., Peer, M. V., Halonen, M., Martinez, F. D., Vercelli, D., & Rothman, P. B. (2011). A SOCS-1 promoter variant is associated with total serum IgE levels. Journal of Immunology, 187(5), 2794-2802.
  More info

  PMID: 21795592;PMCID: PMC3159751;Abstract: SOCS-1 is a critical regulator of multiple signaling pathways, including those activated by cytokines that regulate Ig H chain class switching to IgE. Analysis of mice with mutations in the SOCS-1 gene demonstrated that IgE levels increase with loss of SOCS-1 alleles. This suggested that overall SOCS-1 acts as an inhibitor of IgE expression in vivo. A genetic association study was performed in 474 children enrolled in the Tucson Children's Respiratory Study to determine if genetic variation in the SOCS-1 locus correlates with altered levels of IgE. Carriers of the C-allele for a novel, 39 genomic single nucleotide polymorphism (SNP) in the SOCS-1 gene (SOCS1+1125G > C; rs33932899) were found to have significantly lower levels of serum IgE compared with those of homozygotes for the G-allele. Analysis demonstrated that the SOCS1+1125G > C SNP was in complete linkage disequilibrium with an SNP at position SOCS12820G > T (rs33977706) of the SOCS-1 promoter. Carriers of the T-allele at the SOCS1-820G > T were also found to be associated with the decreased IgE. The promoter SNP increased transcriptional activity of the SOCS-1 promoter in reporter assays and human B cells. Consistent with this observation, the presence of this polymorphism within the promoter abolished binding of yin yang-1, which is identified as a negative regulator of SOCS-1 transcriptional activity. These data suggest that genetic variation in the SOCS-1 promoter may affect IgE production. Copyright © 2011 by The American Association of Immunologists, Inc.
• Mostecki, J., Cassel, S. L., Klimecki, W. T., Stern, D. A., Knisz, J., Iwashita, S., Graves, P., Miller, R. L., van Peer, M., Halonen, M., Martinez, F. D., Vercelli, D., & Rothman, P. B. (2011). A SOCS-1 promoter variant is associated with total serum IgE levels. Journal of immunology (Baltimore, Md. : 1950), 187(5), 2794-802.
  More info

  SOCS-1 is a critical regulator of multiple signaling pathways, including those activated by cytokines that regulate Ig H chain class switching to IgE. Analysis of mice with mutations in the SOCS-1 gene demonstrated that IgE levels increase with loss of SOCS-1 alleles. This suggested that overall SOCS-1 acts as an inhibitor of IgE expression in vivo. A genetic association study was performed in 474 children enrolled in the Tucson Children's Respiratory Study to determine if genetic variation in the SOCS-1 locus correlates with altered levels of IgE. Carriers of the C-allele for a novel, 3' genomic single nucleotide polymorphism (SNP) in the SOCS-1 gene (SOCS1+1125G > C; rs33932899) were found to have significantly lower levels of serum IgE compared with those of homozygotes for the G-allele. Analysis demonstrated that the SOCS1+1125G > C SNP was in complete linkage disequilibrium with an SNP at position SOCS1-820G > T (rs33977706) of the SOCS-1 promoter. Carriers of the T-allele at the SOCS1-820G > T were also found to be associated with the decreased IgE. The promoter SNP increased transcriptional activity of the SOCS-1 promoter in reporter assays and human B cells. Consistent with this observation, the presence of this polymorphism within the promoter abolished binding of yin yang-1, which is identified as a negative regulator of SOCS-1 transcriptional activity. These data suggest that genetic variation in the SOCS-1 promoter may affect IgE production.
• Bolt, A. M., Byrd, R. M., & Klimecki, W. T. (2010). Autophagy is a biological target of arsenic. Arsenic in Geosphere and Human Diseases, As 2010 - 3rd International Congress: Arsenic in the Environment, 291-292.
• Bolt, A. M., Byrd, R. M., & Klimecki, W. T. (2010). Autophagy is the predominant process induced by arsenite in human lymphoblastoid cell lines. Toxicology and Applied Pharmacology, 244(3), 366-373.
  More info

  PMID: 20153345;PMCID: PMC2849852;Abstract: Arsenic is a widespread environmental toxicant with a diverse array of molecular targets and associated diseases, making the identification of the critical mechanisms and pathways of arsenic-induced cytotoxicity a challenge. In a variety of experimental models, over a range of arsenic exposure levels, apoptosis is a commonly identified arsenic-induced cytotoxic pathway. Human lymphoblastoid cell lines (LCL) have been used as a model system in arsenic toxicology for many years, but the exact mechanism of arsenic-induced cytotoxicity in LCL is still unknown. We investigated the cytotoxicity of sodium arsenite in LCL 18564 using a set of complementary markers for cell death pathways. Markers indicative of apoptosis (phosphatidylserine externalization, PARP cleavage, and sensitivity to caspase inhibition) were uniformly negative in arsenite exposed cells. Interestingly, electron microscopy, acidic vesicle fluorescence, and expression of LC3 in LCL 18564 identified autophagy as an arsenite-induced process that was associated with cytotoxicity. Autophagy, a cellular programmed response that is associated with both cellular stress adaptation as well as cell death appears to be the predominant process in LCL cytotoxicity induced by arsenite. It is unclear, however, whether LCL autophagy is an effector mechanism of arsenite cytotoxicity or alternatively a cellular compensatory mechanism. The ability of arsenite to induce autophagy in lymphoblastoid cell lines introduces a potentially novel mechanistic explanation of the well-characterized in vitro and in vivo toxicity of arsenic to lymphoid cells. © 2010 Elsevier Inc.
• Bolt, A. M., Douglas, R. M., & Klimecki, W. T. (2010). Arsenite exposure in human lymphoblastoid cell lines induces autophagy and coordinated induction of lysosomal genes. Toxicology Letters, 199(2), 153-159.
  More info

  PMID: 20816728;PMCID: PMC2956852;Abstract: Chronic exposure to inorganic arsenic is associated with diverse, complex diseases, making the identification of the mechanism underlying arsenic-induced toxicity a challenge. An increasing body of literature from epidemiological and in vitro studies has demonstrated that arsenic is an immunotoxicant, but the mechanism driving arsenic-induced immunotoxicity is not well established. We have previously demonstrated that in human lymphoblastoid cell lines (LCLs), arsenic-induced cell death is strongly associated with the induction of autophagy. In this study we utilized genome-wide gene expression analysis and functional assays to characterize arsenic-induced effects in seven LCLs that were exposed to an environmentally relevant, minimally cytotoxic, concentration of arsenite (0.75 μM) over an eight-day time course. Arsenic exposure resulted in inhibition of cellular growth and induction of autophagy (measured by expansion of acidic vesicles) over the eight-day exposure duration. Gene expression analysis revealed that arsenic exposure increased global lysosomal gene expression, which was associated with increased functional activity of the lysosome protease, cathepsin D. The arsenic-induced expansion of the lysosomal compartment in LCL represents a novel target that may offer insight into the immunotoxic effects of arsenic. © 2010 Elsevier Ireland Ltd.
• Gomez-Rubio, P., Meza-Montenegro, M. M., Cantu-Soto, E., & Klimecki, W. T. (2010). Genetic association between intronic variants in AS3MT and arsenic methylation efficiency is focused on a large linkage disequilibrium cluster in chromosome 10. Journal of Applied Toxicology, 30(3), 260-270.
  More info

  PMID: 20014157;PMCID: PMC2862143;Abstract: Differences in arsenic metabolism are known to play a role in individual variability in arsenic-induced disease susceptibility. Genetic variants in genes relevant to arsenic metabolism are considered to be partially responsible for the variation in arsenic metabolism. Specifically, variants in arsenic (3+ oxidation state) methyltransferase (AS3MT), the key gene in the metabolism of arsenic, have been associated with increased arsenic methylation efficiency. Of particular interest is the fact that different studies have reported that several of the AS3MT single nucleotide polymorphisms (SNPs) are in strong linkage-disequilibrium (LD), which also extends to a nearby gene, CYP17A1. In an effort to characterize the extent of the region in LD, we genotyped 46 SNPs in a 347 000 base region of chromosome 10 that included AS3MT in arsenic-exposed subjects from Mexico. Pairwise LD analysis showed strong LD for these polymorphisms, represented by a mean r2 of 0.82, spanning a region that includes five genes. Genetic association analysis with arsenic metabolism confirmed the previously observed association between AS3MT variants, including this large cluster of linked polymorphisms, and arsenic methylation efficiency. The existence of a large genomic region sharing strong LD with polymorphisms associated with arsenic metabolism presents a predicament because the observed phenotype cannot be unequivocally assigned to a single SNP or even a single gene. The results reported here should be carefully considered for future genomic association studies involving AS3MT and arsenic metabolism. Copyright © 2009 John Wiley & Sons, Ltd.
• Klimecki, W., Bolt, A. M., Byrd, R. M., & Klimecki, W. -. (2010). Autophagy is the predominant process induced by arsenite in human lymphoblastoid cell lines. Toxicology and applied pharmacology, 244(3).
  More info

  Arsenic is a widespread environmental toxicant with a diverse array of molecular targets and associated diseases, making the identification of the critical mechanisms and pathways of arsenic-induced cytotoxicity a challenge. In a variety of experimental models, over a range of arsenic exposure levels, apoptosis is a commonly identified arsenic-induced cytotoxic pathway. Human lymphoblastoid cell lines (LCL) have been used as a model system in arsenic toxicology for many years, but the exact mechanism of arsenic-induced cytotoxicity in LCL is still unknown. We investigated the cytotoxicity of sodium arsenite in LCL 18564 using a set of complementary markers for cell death pathways. Markers indicative of apoptosis (phosphatidylserine externalization, PARP cleavage, and sensitivity to caspase inhibition) were uniformly negative in arsenite exposed cells. Interestingly, electron microscopy, acidic vesicle fluorescence, and expression of LC3 in LCL 18564 identified autophagy as an arsenite-induced process that was associated with cytotoxicity. Autophagy, a cellular programmed response that is associated with both cellular stress adaptation as well as cell death appears to be the predominant process in LCL cytotoxicity induced by arsenite. It is unclear, however, whether LCL autophagy is an effector mechanism of arsenite cytotoxicity or alternatively a cellular compensatory mechanism. The ability of arsenite to induce autophagy in lymphoblastoid cell lines introduces a potentially novel mechanistic explanation of the well-characterized in vitro and in vivo toxicity of arsenic to lymphoid cells.
• Klimecki, W., Bolt, A. M., Douglas, R. M., & Klimecki, W. -. (2010). Arsenite exposure in human lymphoblastoid cell lines induces autophagy and coordinated induction of lysosomal genes. Toxicology letters, 199(2).
  More info

  Chronic exposure to inorganic arsenic is associated with diverse, complex diseases, making the identification of the mechanism underlying arsenic-induced toxicity a challenge. An increasing body of literature from epidemiological and in vitro studies has demonstrated that arsenic is an immunotoxicant, but the mechanism driving arsenic-induced immunotoxicity is not well established. We have previously demonstrated that in human lymphoblastoid cell lines (LCLs), arsenic-induced cell death is strongly associated with the induction of autophagy. In this study we utilized genome-wide gene expression analysis and functional assays to characterize arsenic-induced effects in seven LCLs that were exposed to an environmentally relevant, minimally cytotoxic, concentration of arsenite (0.75 μM) over an eight-day time course. Arsenic exposure resulted in inhibition of cellular growth and induction of autophagy (measured by expansion of acidic vesicles) over the eight-day exposure duration. Gene expression analysis revealed that arsenic exposure increased global lysosomal gene expression, which was associated with increased functional activity of the lysosome protease, cathepsin D. The arsenic-induced expansion of the lysosomal compartment in LCL represents a novel target that may offer insight into the immunotoxic effects of arsenic.
• Klimecki, W., Gomez-Rubio, P., Meza-Montenegro, M. M., Cantu-Soto, E., & Klimecki, W. -. (2010). Genetic association between intronic variants in AS3MT and arsenic methylation efficiency is focused on a large linkage disequilibrium cluster in chromosome 10. Journal of applied toxicology : JAT, 30(3).
  More info

  Differences in arsenic metabolism are known to play a role in individual variability in arsenic-induced disease susceptibility. Genetic variants in genes relevant to arsenic metabolism are considered to be partially responsible for the variation in arsenic metabolism. Specifically, variants in arsenic (3+ oxidation state) methyltransferase (AS3MT), the key gene in the metabolism of arsenic, have been associated with increased arsenic methylation efficiency. Of particular interest is the fact that different studies have reported that several of the AS3MT single nucleotide polymorphisms (SNPs) are in strong linkage-disequilibrium (LD), which also extends to a nearby gene, CYP17A1. In an effort to characterize the extent of the region in LD, we genotyped 46 SNPs in a 347,000 base region of chromosome 10 that included AS3MT in arsenic-exposed subjects from Mexico. Pairwise LD analysis showed strong LD for these polymorphisms, represented by a mean r(2) of 0.82, spanning a region that includes five genes. Genetic association analysis with arsenic metabolism confirmed the previously observed association between AS3MT variants, including this large cluster of linked polymorphisms, and arsenic methylation efficiency. The existence of a large genomic region sharing strong LD with polymorphisms associated with arsenic metabolism presents a predicament because the observed phenotype cannot be unequivocally assigned to a single SNP or even a single gene. The results reported here should be carefully considered for future genomic association studies involving AS3MT and arsenic metabolism.
• Kenyon, E. M., Klimecki, W. T., El-Masri, H., Conolly, R. B., Clewell, H. J., & Beck, B. D. (2008). How can biologically-based modeling of arsenic kinetics and dynamics inform the risk assessment process? - A workshop review. Toxicology and Applied Pharmacology, 232(3), 359-368.
  More info

  PMID: 18687352;Abstract: Quantitative biologically-based models describing key events in the continuum from arsenic exposure to the development of adverse health effects provide a framework to integrate information obtained across diverse research areas. For example, genetic polymorphisms in arsenic metabolizing enzymes can lead to differences in target tissue dosimetry for key metabolites causative in toxic and carcinogenic response. This type of variation can be quantitatively incorporated into pharmacokinetic (PK) models and used together with population-based modeling approaches to evaluate the impact of genetic variation in methylation capacity on dose of key metabolites to target tissue. The PK model is an essential bridge to the pharmacodynamic (PD) models. A particular benefit of PD modeling for arsenic is that alternative models can be constructed for multiple proposed modes of action for arsenicals. Genomics data will prove useful for identifying the key pathways involved in particular responses and aid in determining other types of data needed for quantitative modeling. These models, when linked with PK models, can be used to better understand and explain dose- and time-response behaviors. This in turn assists in prioritizing modes of action with respect to their risk assessment relevance and future research. This type of integrated modeling approach can form the basis for a highly informative mode-of-action directed risk assessment for inorganic arsenic (iAs). This paper will address both practical and theoretical aspects of integrating PK and PD data in a modeling framework, including practical barriers to its application.
• Kenyon, E. M., Klimecki, W. T., El-Masri, H., Conolly, R. B., Clewell, H. J., & Beck, B. D. (2008). How can biologically-based modeling of arsenic kinetics and dynamics inform the risk assessment process? - A workshop review. Toxicology and applied pharmacology, 232(3), 359-68.
  More info

  Quantitative biologically-based models describing key events in the continuum from arsenic exposure to the development of adverse health effects provide a framework to integrate information obtained across diverse research areas. For example, genetic polymorphisms in arsenic metabolizing enzymes can lead to differences in target tissue dosimetry for key metabolites causative in toxic and carcinogenic response. This type of variation can be quantitatively incorporated into pharmacokinetic (PK) models and used together with population-based modeling approaches to evaluate the impact of genetic variation in methylation capacity on dose of key metabolites to target tissue. The PK model is an essential bridge to the pharmacodynamic (PD) models. A particular benefit of PD modeling for arsenic is that alternative models can be constructed for multiple proposed modes of action for arsenicals. Genomics data will prove useful for identifying the key pathways involved in particular responses and aid in determining other types of data needed for quantitative modeling. These models, when linked with PK models, can be used to better understand and explain dose- and time-response behaviors. This in turn assists in prioritizing modes of action with respect to their risk assessment relevance and future research. This type of integrated modeling approach can form the basis for a highly informative mode-of-action directed risk assessment for inorganic arsenic (iAs). This paper will address both practical and theoretical aspects of integrating PK and PD data in a modeling framework, including practical barriers to its application.
• Kripke, D. F., Rex, K. M., Ancoli-Israel, S., Nievergelt, C. M., Klimecki, W., & Kelsoe, J. R. (2008). Delayed sleep phase cases and controls. Journal of Circadian Rhythms, 6.
  More info

  PMID: 18445295;PMCID: PMC2391143;Abstract: Background: Delayed sleep phase disorder (DSPD) is a condition in which patients have difficulty falling asleep before the early morning hours and commonly have trouble awakening before late morning or even early afternoon. Several studies have suggested that variations in habitual bedtime are 40-50% heritable. Methods: We recruited a case series of 205 participants, along with 221 controls (DSPD-C) with normal sleep, roughly matched for age, gender, and ancestry. A representative sample of San Diego adults recruited some years before was already available to confirm the control group. Both DSPD and DSPD-C provided blood or saliva samples for DNA and completed extensive questionnaires about sleep habits, sleep history, family history, sleep quality, morningness-eveningness traits, depression, mania, and seasonality of symptoms. The DSPD group wore wrist actigraphs for a median of 13.2 days. The representative sample collected previously had undergone actigraphic recordings, from which 48 hours of data were generally available. Results: The DSPD and DSPD-C samples showed almost no overlap on morningness-eveningness scores. DSPD cases went to bed and arose about 3 hours later than the DSPD-C and the representative sample. DSPD cases reported more difficulties with sleep, poorer sleep quality, and more depression, but there was no significant difference in a history of mania. DSPD cases reported more family history of late bedtimes, but female DSPD reported that their fathers' bedtimes were later than the fathers of male DSPD. Conclusion: These results indicate a DSPD phenotype is familial and associated with unipolar depression. © 2008 Kripke et al; licensee BioMed Central Ltd.
• Kripke, D. F., Rex, K. M., Ancoli-Israel, S., Nievergelt, C. M., Klimecki, W., & Kelsoe, J. R. (2008). Delayed sleep phase cases and controls. Journal of circadian rhythms, 6, 6.
  More info

  Delayed sleep phase disorder (DSPD) is a condition in which patients have difficulty falling asleep before the early morning hours and commonly have trouble awakening before late morning or even early afternoon. Several studies have suggested that variations in habitual bedtime are 40-50% heritable.
• Yu, L., Vidrine, A. N., Klimecki, W. T., Kalla, K., & Guthrie, E. (2008). Genetic Variation in Genes Associated with Arsenic Metabolism. Environmental Health Perspectives. doi:10.1289/txg.6420
• Bieli, C., Eder, W., Frei, R., Braun-Fahrländer, C., Klimecki, W., Waser, M., Riedler, J., Mutius, E. v., Scheynius, A., Pershagen, G., Doekes, G., Lauener, R., & Martinez, F. D. (2007). A polymorphism in CD14 modifies the effect of farm milk consumption on allergic diseases and CD14 gene expression. Journal of Allergy and Clinical Immunology, 120(6), 1308-1315.
  More info

  PMID: 17919709;Abstract: Background: Consumption of farm milk in early life is associated with less asthma and allergies. Objective: We hypothesized that genetic variation in the innate immunity receptor CD14 might modify the association between farm milk consumption and asthma and atopy. Methods: Questionnaire data, serum IgE levels, and genotypes for 4 single nucleotide polymorphisms in CD14 were assessed in farmers' and nonfarmers' children from 2 European populations (Allergy and Endotoxin study, n = 576; Prevention of Allergy Risk factors for Sensitization in children related to Farming and Anthroposophic Lifestyle study, n = 1539). In a subsample (n = 222) CD14 gene expression was measured in peripheral blood leukocytes. The effects of farm milk and CD14 genotypes on asthma, allergies, and CD14 expression and their interactions were investigated. Results: We found a significant interaction between genetic variation in CD14/-1721 and farm milk consumption. Adjusted odds ratios for the association between farm milk and asthma varied between the genotypes: AA, 0.18 (95% CI, 0.07-0.47); AG, 0.47 (95% CI, 0.26-0.86); and GG, 0.98 (95% CI, 0.46-2.08). Similar patterns were observed for symptoms of allergic rhinoconjunctivitis and pollen sensitization. CD14/-1721 also modified the association between farm milk and CD14 gene expression (adjusted geometric means ratios: AA, 1.61 (95% CI, 0.98-2.66); AG, 1.11 (95% CI, 0.71-1.72); and GG, 0.76 (95% CI, 0.39-1.48). Conclusion: The protective effect of farm milk consumption on allergic diseases is stronger in children carrying the A allele in CD14/-1721 than in children homozygous for the G allele. This might be mediated through farm milk-induced upregulated CD14 gene expression. Clinical implications: Our results support the hypothesis that the inverse association between farm milk consumption and allergic diseases is mediated by CD14-activated innate immune mechanisms. © 2007 American Academy of Allergy, Asthma & Immunology.
• Bieli, C., Eder, W., Frei, R., Braun-Fahrländer, C., Klimecki, W., Waser, M., Riedler, J., von Mutius, E., Scheynius, A., Pershagen, G., Doekes, G., Lauener, R., Martinez, F. D., & , P. s. (2007). A polymorphism in CD14 modifies the effect of farm milk consumption on allergic diseases and CD14 gene expression. The Journal of allergy and clinical immunology, 120(6), 1308-15.
  More info

  Consumption of farm milk in early life is associated with less asthma and allergies.
• Meza, M., Gandolfi, A. J., & Klimecki, W. T. (2007). Developmental and genetic modulation of arsenic biotransformation: A gene by environment interaction?. Toxicology and Applied Pharmacology, 222(3), 381-387.
  More info

  PMID: 17306849;PMCID: PMC2040165;Abstract: The complexity of arsenic toxicology has confounded the identification of specific pathways of disease causation. One focal point of arsenic research is aimed at fully characterizing arsenic biotransformation in humans, a process that appears to be quite variable, producing a mixture of several arsenic species with greatly differing toxic potencies. In an effort to characterize genetic determinants of variability in arsenic biotransformation, a genetic association study of 135 subjects in western Sonora, Mexico was performed by testing 23 polymorphic sites in three arsenic biotransformation candidate genes. One gene, arsenic 3 methyltransferase (AS3MT), was strongly associated with the ratio of urinary dimethylarsinic acid to monomethylarsonic acid (D/M) in children (7-11 years) but not in adults (18-79 years). Subsequent analyses revealed that the high D/M values associated with variant AS3MT alleles were primarily due to lower levels of monomethylarsonic acid as percent of total urinary arsenic (%MMA5). In light of several reports of arsenic-induced disease being associated with relatively high %MMA5 levels, these findings raise the possibility that variant AS3MT individuals may suffer less risk from arsenic exposure than non-variant individuals. These analyses also provide evidence that, in this population, regardless of AS3MT variant status, children tend to have lower %MMA5 values than adults, suggesting that the global developmental regulation of arsenic biotransformation may interact with genetic variants in metabolic genes to result in novel genetic effects such as those in this report. © 2007 Elsevier Inc. All rights reserved.
• Meza, M., Gandolfi, A. J., & Klimecki, W. T. (2007). Developmental and genetic modulation of arsenic biotransformation: a gene by environment interaction?. Toxicology and applied pharmacology, 222(3), 381-7.
  More info

  The complexity of arsenic toxicology has confounded the identification of specific pathways of disease causation. One focal point of arsenic research is aimed at fully characterizing arsenic biotransformation in humans, a process that appears to be quite variable, producing a mixture of several arsenic species with greatly differing toxic potencies. In an effort to characterize genetic determinants of variability in arsenic biotransformation, a genetic association study of 135 subjects in western Sonora, Mexico was performed by testing 23 polymorphic sites in three arsenic biotransformation candidate genes. One gene, arsenic 3 methyltransferase (AS3MT), was strongly associated with the ratio of urinary dimethylarsinic acid to monomethylarsonic acid (D/M) in children (7-11 years) but not in adults (18-79 years). Subsequent analyses revealed that the high D/M values associated with variant AS3MT alleles were primarily due to lower levels of monomethylarsonic acid as percent of total urinary arsenic (%MMA5). In light of several reports of arsenic-induced disease being associated with relatively high %MMA5 levels, these findings raise the possibility that variant AS3MT individuals may suffer less risk from arsenic exposure than non-variant individuals. These analyses also provide evidence that, in this population, regardless of AS3MT variant status, children tend to have lower %MMA5 values than adults, suggesting that the global developmental regulation of arsenic biotransformation may interact with genetic variants in metabolic genes to result in novel genetic effects such as those in this report.
• Palmer, S. M., Klimecki, W., Yu, L., Reinsmoen, N. L., Snyder, L. D., Ganous, T. M., Burch, L., & Schwartz, D. A. (2007). Genetic regulation of rejection and survival following human lung transplantation by the innate immune receptor CD14. American Journal of Transplantation, 7(3), 693-699.
  More info

  PMID: 17217435;Abstract: We have developed the hypothesis that genetic polymorphisms which alter the expression or function of innate immune receptors contribute to the marked interindividual differences in the onset and severity of lung transplant rejection. In this analysis, we considered the effects of a common promotor polymorphism of the lipopolysaccharide receptor CD14 associated with increased transcriptional activity upon the development of posttransplant rejection and graft survival. Genotyping was performed in 226 lung transplant recipients well characterized with regards to clinical outcomes. An earlier onset of acute rejection, bronchiolitis obliterans syndrome (BOS) and worse posttransplant graft survival due to greater BOS related deaths was evident in patients with the CD14 -159 TT genotype (TT). The adverse effect upon graft survival of the TT genotype remained significant in a multivariate Cox model (Hazard Ratio 1.65, 95% CI, 1.03-2.64, p-value = 0.04) after adjusting for other important covariates. Furthermore, TT patients have significantly greater sCD14, TNF-α and IFN-γ in the peripheral blood implying a heightened state of innate immune activation drives the development of increased post-transplant rejection. Inhibition of innate immune activation through CD14 represents a novel and potentially important therapeutic target to prevent post-transplant rejection and improve outcomes after human lung transplantation. © 2007 The Authors.
• Webster, R. B., Rodriguez, Y., Klimecki, W. T., & Vercelli, D. (2007). The human IL-13 locus in neonatal CD4⁺ T cells is refractory to the acquisition of a repressive chromatin architecture. Journal of Biological Chemistry, 282(1), 700-709.
  More info

  PMID: 17090525;Abstract: The Th2 cytokine IL-13 is a major effector molecule in human allergic inflammation. Notably, IL-13 expression at birth correlates with subsequent susceptibility to atopic disease. In order to characterize the chromatin-based mechanisms that regulate IL-13 expression in human neonatal CD4+ T cells, we analyzed patterns of DNase I hypersensitivity and epigenetic modifications within the IL-13 locus in cord blood CD4+ T cells, naive or differentiated in vitro under Th1- or Th2-polarizing conditions. In naive CD4+ T cells, hypersensitivity associated with DNA hypomethylation was limited to the distal promoter. Unexpectedly, during both Th1 and Th2 differentiation, the locus was extensively remodeled, as revealed by the formation of numerous HS sites and decreased DNA methylation. Obvious differences in chromatin architecture were limited to the proximal promoter, where strong hypersensitivity, hypomethylation, and permissive histone modifications were found selectively in Th2 cells. In addition to revealing the locations of putative cis-regulatory elements thatmaybe required to control IL-13 expression in neonatal CD4+ T cells, our results suggest that differential IL-13 expression may depend on the acquisition of a permissive chromatin architecture at the proximal promoter in Th2 cells rather than the formation of locus-wide repressive chromatin in Th1 cells. © 2007 by The American Society for Biochemistry and Molecular Biology, Inc.
• Wozniak, R. J., Klimecki, W. T., Lau, S. S., Feinstein, Y., & Futscher, B. W. (2007). 5-Aza-2'-deoxycytidine-mediated reductions in G9A histone methyltransferase and histone H3 K9 di-methylation levels are linked to tumor suppressor gene reactivation. Oncogene, 26(1), 77-90.
  More info

  The epigenetic silencing of tumor suppressor genes is a common event during carcinogenesis, and often involves aberrant DNA methylation and histone modification of gene regulatory regions, resulting in the formation of a transcriptionally repressive chromatin state. Two examples include the antimetastatic, tumor suppressor genes, desmocollin 3 (DSC3) and MASPIN, which are frequently silenced in this manner in human breast cancer. Treatment of the breast tumor cell lines MDA-MB-231 and UACC 1179 with 5-aza-2'-deoxycytidine (5-aza-CdR) induced transcriptional reactivation of both genes in a dose-dependent manner. Importantly, DSC3 and MASPIN reactivation was closely and consistently linked with significant decreases in promoter H3 K9 di-methylation. Moreover, 5-aza-CdR treatment also resulted in global decreases in H3 K9 di-methylation, an effect that was linked to its ability to mediate dose-dependent, post-transcriptional decreases in the key enzyme responsible for this epigenetic modification, G9A. Finally, small interfering RNA (siRNA)-mediated knockdown of G9A and DNMT1 led to increased MASPIN expression in MDA-MB-231 cells, to levels that were supra-additive, verifying the importance of these enzymes in maintaining multiple layers of epigenetic repression in breast tumor cells. These results highlight an additional, complimentary mechanism of action for 5-aza-CdR in the reactivation of epigenetically silenced genes, in a manner that is independent of its effects on DNA methylation, further supporting an important role for H3 K9 methylation in the aberrant repression of tumor suppressor genes in human cancer.
• Cameron, L., Webster, R. B., Strempel, J. M., Kiesler, P., Kabesch, M., Ramachandran, H., Lizhi, Y. u., Stern, D. A., Graves, P. E., Lohman, I. C., Wright, A. L., Halonen, M., Klimecki, W. T., & Vercelli, D. (2006). Th2 cell-selective enhancement of human IL13 transcription by IL13-1112C>T, a polymorphism associated with allergic inflammation. Journal of Immunology, 177(12), 8633-8642.
  More info

  PMID: 17142763;Abstract: IL-13 is a central mediator of allergic inflammation. The single nucleotide polymorphism IL13-1112C>T (rs1800925) is associated with allergic phenotypes in ethnically distinct populations, but the underlying mechanism(s) remain unknown. Using in vivo, in vitro, and in silico analysis, we show that the IL13-1112T allele enhanced IL13 promoter activity in primary human and murine CD4+ Th2 lymphocytes. Increased expression of IL13-1112T in Th2 cells was associated with the creation of a Yin-Yang 1 binding site that overlapped a STAT motif involved in negative regulation of IL13 expression and attenuated STAT6-mediated transcriptional repression. Because IL-13 secretion was increased in IL13-1112TT homozygotes, we propose that increased expression of IL13-1112T in vivo may underlie its association with susceptibility to allergic inflammation. Interestingly, IL13-1112T had opposite transcriptional effects in nonpolarized CD4+ T cells, paralleled by distinct patterns of DNA-protein interactions at the IL13 promoter. Our findings suggest the nuclear milieu dictates the functional outcome of genetic variation. Copyright © 2006 by The American Association of Immunologists, Inc.
• Cameron, L., Webster, R. B., Strempel, J. M., Kiesler, P., Kabesch, M., Ramachandran, H., Yu, L., Stern, D. A., Graves, P. E., Lohman, I. C., Wright, A. L., Halonen, M., Klimecki, W. T., & Vercelli, D. (2006). Th2 cell-selective enhancement of human IL13 transcription by IL13-1112C>T, a polymorphism associated with allergic inflammation. Journal of immunology (Baltimore, Md. : 1950), 177(12), 8633-42.
  More info

  IL-13 is a central mediator of allergic inflammation. The single nucleotide polymorphism IL13-1112C>T (rs1800925) is associated with allergic phenotypes in ethnically distinct populations, but the underlying mechanism(s) remain unknown. Using in vivo, in vitro, and in silico analysis, we show that the IL13-1112T allele enhanced IL13 promoter activity in primary human and murine CD4(+) Th2 lymphocytes. Increased expression of IL13-1112T in Th2 cells was associated with the creation of a Yin-Yang 1 binding site that overlapped a STAT motif involved in negative regulation of IL13 expression and attenuated STAT6-mediated transcriptional repression. Because IL-13 secretion was increased in IL13-1112TT homozygotes, we propose that increased expression of IL13-1112T in vivo may underlie its association with susceptibility to allergic inflammation. Interestingly, IL13-1112T had opposite transcriptional effects in nonpolarized CD4(+) T cells, paralleled by distinct patterns of DNA-protein interactions at the IL13 promoter. Our findings suggest the nuclear milieu dictates the functional outcome of genetic variation.
• Eder, W., Klimecki, W., Yu, L., Mutius, E. V., Riedler, J., Braun-Fahrländer, C., Nowak, D., Holst, O., & Martinez, F. D. (2006). Association between exposure to farming, allergies and genetic variation in CARD4/NOD1. Allergy: European Journal of Allergy and Clinical Immunology, 61(9), 1117-1124.
  More info

  PMID: 16918516;Abstract: Background: Caspase recruitment domain protein (CARD) 4 has been recently identified as an intracellular pattern recognition receptor that interacts with muropeptides found in common Gram-negative bacteria. We therefore aimed to explore whether the previously observed inverse association between exposure to microbial products and asthma and allergies in childhood is modified by genetic variation in CARD4. Methods: We genotyped 668 children [mean age 9.3 (SD 1.5) years] enrolled in the cross-sectional ALEX study for seven haplotype tagging single nucleotide polymorphisms in CARD4. We studied the association of asthma, hay fever and allergen-specific serum immunoglobulin E with exposure to a farming environment and with levels of endotoxin and muramic acid measured in house dust samples. We tested whether these associations differed between the genotypes of the polymorphisms under study. Results: A strong protective effect of a farming environment on allergies was only found in children homozygous for the T allele in CARD4/-21596, but not in children carrying the minor allele (C). Among the former, farmers' children had a significantly lower frequency of sensitization against pollen (5.8%), hay fever (1.7%) and atopic asthma symptoms (1.7%) compared with children not living on a farm (19.4%, 13.0% and 7.6%, P < 0.01,
• Flores, R., Papenfuss, M., Klimecki, W. T., & Giuliano, A. R. (2006). Cross-sectional analysis of oncogenic HPV viral load and cervical intraepithelial neoplasia. International Journal of Cancer, 118(5), 1187-1193.
  More info

  PMID: 16152619;Abstract: In human papillomavirus (HPV)-associated carcinogenesis, HPV infection characteristics such as viral load may play an important role in lesion development. The purpose of this study was to determine the association between quantitative assessment of oncogenic HPV viral load, and abnormal cytology among women residing along the United States-Mexico border. A cross-sectional study of 2,319 women was conducted between 1997 and 1998. Viral load of oncogenic HPV types (16, 18, 31, 39, 45, 51, 52, and 58) was measured among 173 HPV (+) women using quantitative real-time PCR. Overall, HPV 16, 31, 52 and 58 showed the highest viral load. Single type infection had higher viral loads compared to multiple type infections. HPV viral load declined significantly (p = 0.04) with age. No significant association was observed with other known HPV risk factors such as oral contraceptive use, parity, sexual and STD history. Viral load was independently associated with degree of cervical lesions. An adjusted odds ratio (AOR) of 4.7 for the association between increasing total viral load and Atypical Squamous Cells of Undetermined Significance (ASCUS)/Atypical Glandular Cells of Undetermined Significance (AGUS) was observed (p for trend
• LeVan, T. D., Guerra, S., Klimecki, W., Vasquez, M. M., Lohman, I. C., Martinez, F. D., Halonen, M., & Wright, A. L. (2006). The impact of CD14 polymorphisms on the development of soluble CD14 levels during infancy. Genes and Immunity, 7(1), 77-80.
  More info

  PMID: 16395394;Abstract: CD14 is a receptor involved in the recognition of lipopolysaccharide and other bacterial wall components that may be involved in the balance between infectious and allergic disease and the early polarization towards TH1. Our group has shown an association between polymorphisms in the 5′ flanking region of the CD14 gene and plasma soluble CD14 (sCD14) levels at 11 years of age. However, whether this association is present at birth and in infancy remains to be determined. In this study, we measured sCD14 levels in plasma from the umbilical cord (n = 387) and at 3 months (n = 357) and 1 year (n=312) of age in non-selected healthy infants to assess their relationship with CD14 genotypes at -4190, -2838, -1720 and -260 (relative to translation start site). There was no relation of CD14 genotypes with sCD14 at birth. However, there was a significant association between CD14 genotypes and sCD14 as early as 3 months. Longitudinal analysis suggests that CD14 polymorphisms modulate sCD14 levels up to 1 year of age. This association early in life may have an impact on TH1 polarization and subsequent protection against allergic disease. © 2006 Nature Publishing Group All rights reserved.
• Martínez, M. E., Thompson, P., Jacobs, E. T., Giovannucci, E., Jiang, R., Klimecki, W., & Alberts, D. S. (2006). Dietary Factors and Biomarkers Involved in the Methylenetetrahydrofolate Reductase Genotype-Colorectal Adenoma Pathway. Gastroenterology, 131(6), 1706-1716.
  More info

  PMID: 17087956;Abstract: Background & Aims: Methylenetetrahydrofolate reductase (MTHFR) is involved in intracellular folate homeostasis and metabolism. We assessed 2 polymorphisms in the MTHFR gene (C677T and A1298C) in relation to colorectal adenoma recurrence and conducted analyses to investigate their joint effects with plasma and dietary markers of folate status. Methods: We prospectively analyzed data from 1598 individuals genotyped for the C677T polymorphism and 1583 with data on A1298C. Results: Among nonusers of multivitamin supplements, compared with wild-type carriage, higher odds of recurrence were observed for those with the 677 TT variant (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.04-2.63) and a nonsignificant increase was observed among those with the 1298 CC variant (OR, 1.50; 95% CI, 0.93-2.40). Diplotype analyses among nonusers of multivitamins showed that individuals who carry the MTHFR 677TT_1298AA or 677CC_1298CC combination were significantly more likely to have a recurrence compared with those with the double wild-type (OR, 2.05 for TT_AA and 1.85 for CC_CC). Higher odds of recurrence were observed among participants with low folate intake or plasma folate and the 677 TT or 1298 CC variants compared with those with lower levels and the wild-type or heterozygous genotypes. Stronger associations were shown for the combination of high homocysteine and the 677 TT variant (OR, 2.29; 95% CI, 1.00-5.26) but not the 1298 CC variant (OR, 1.09; 95% CI, 0.39-3.01). Conclusions: We propose that the effect of the MTHFR genotypes on increasing risk of adenoma recurrence in the presence of a low folate status is through their increase in homocysteine concentrations, which in turn could result in DNA hypomethylation via pathways involving S-adenosylhomocysteine. © 2006 AGA Institute.
• Martínez, M. E., Thompson, P., Jacobs, E. T., Giovannucci, E., Jiang, R., Klimecki, W., & Alberts, D. S. (2006). Dietary factors and biomarkers involved in the methylenetetrahydrofolate reductase genotype-colorectal adenoma pathway. Gastroenterology, 131(6), 1706-16.
  More info

  Methylenetetrahydrofolate reductase (MTHFR) is involved in intracellular folate homeostasis and metabolism. We assessed 2 polymorphisms in the MTHFR gene (C677T and A1298C) in relation to colorectal adenoma recurrence and conducted analyses to investigate their joint effects with plasma and dietary markers of folate status.
• Novak, P., Jensen, T., Oshiro, M. M., Wozniak, R. J., Nouzova, M., Watts, G. S., Klimecki, W. T., Kim, C., & Futscher, B. W. (2006). Epigenetic inactivation of the HOXA gene cluster in breast cancer. Cancer research, 66(22), 10664-70.
  More info

  Using an integrated approach of epigenomic scanning and gene expression profiling, we found aberrant methylation and epigenetic silencing of a small neighborhood of contiguous genes-the HOXA gene cluster in human breast cancer. The observed transcriptional repression was localized to approximately 100 kb of the HOXA gene cluster and did not extend to genes located upstream or downstream of the cluster. Bisulfite sequencing, chromatin immunoprecipitation, and quantitative reverse transcription-PCR analysis confirmed that the loss of expression of the HOXA gene cluster in human breast cancer is closely linked to aberrant DNA methylation and loss of permissive histone modifications in the region. Pharmacologic manipulations showed the importance of these aberrant epigenetic changes in gene silencing and support the hypothesis that aberrant DNA methylation is dominant to histone hypoacetylation. Overall, these data suggest that inactivation of the HOXA gene cluster in breast cancer may represent a new type of genomic lesion-epigenetic microdeletion. We predict that epigenetic microdeletions are common in human cancer and that they functionally resemble genetic microdeletions but are defined by epigenetic inactivation and transcriptional silencing of a relatively small set of contiguous genes along a chromosome, and that this type of genomic lesion is metastable and reversible in a classic epigenetic fashion.
• Waser, M., Riedler, J., Pershagen, G., Nder, C. B., Mutius, E. V., Martinez, F. D., Lauener, R., Klimecki, W. T., Frei, R., Eder, W., Braun-fahrlander, C., & Bieli, C. H. (2006). A CD14 Polymorphism Modifies the Effect of Farm Milk Consumption on Allergic Diseases and Alters Gene Expression of CD14. Epidemiology, 17(Suppl), S151. doi:10.1097/00001648-200611001-00378
• Eder, W., Klimecki, W., Lizhi, Y. u., Mutius, E. V., Riedler, J., Braun-Fahrländer, C., Nowak, D., & Martinez, F. D. (2005). Opposite effects of CD14/-260 on serum IgE levels in children raised in different environments. Journal of Allergy and Clinical Immunology, 116(3), 601-607.
  More info

  PMID: 16159630;Abstract: Background: Most complex diseases are the result of interactions between polymorphisms in the genome and environmental exposures. Objective: We sought to investigate the previously reported association between a polymorphism in the promoter region of CD14 (CD14/-260C→T) and serum IgE levels in relation to the environment to which children are exposed. Methods: In 624 children living in 2 rural communities in Europe, we compared total and specific serum IgE levels between the genotypes of CD14/-260 in relation to exposure to animals and in relation to house dust endotoxin. Results: We found that the C allele of CD14/-260 was associated with higher levels of both total and specific serum IgE to aeroallergens in children with regular contact with pets, whereas an association in the opposite direction was found in children with regular contact with stable animals. This modifying effect of animal exposure was not explained by levels of house dust endotoxin. However, in children with high levels of house dust endotoxin, the C allele was associated with less specific IgE, independently from animal exposure. Conclusion: Because CD14 is a pattern recognition receptor for microbial molecules, the results suggest that the type and concentrations of such molecules present in the environment strongly determine the direction of the association between CD14/-260 and serum markers of atopy. © 2005 American Academy of Allergy, Asthma and Immunology.
• Graves, P. E., Siroux, V., Guerra, S., Klimecki, W. T., & Martinez, F. D. (2005). Association of atopy and eczema with polymorphisms in T-cell immunoglobulin domain and mucin domain - IL-2-inducible T-cell kinase gene cluster in chromosome 5q33. Journal of Allergy and Clinical Immunology, 116(3), 650-656.
  More info

  PMID: 16159638;Abstract: Background: The T-cell immunoglobulin domain and mucin domain (TIM) gene family and the gene for IL-2-inducible T-cell kinase (ITK), located in chromosome 5q33 and potentially involved in the T-cell proliferation and differentiation, are good candidate genes for allergic diseases. Objective: We assessed the role of polymorphisms in the TIM family genes and ITK in atopy, eczema, and asthma. Methods: Twenty-one polymorphisms in the TIM-ITK gene cluster were genotyped in 564 children enrolled in the Tucson Children's Respiratory Study. Skin prick tests to common allergens were performed at age 6.1 years (n = 508), age 10.8 years (n = 539), and age 16.6 years (n = 424). Asthma and eczema were assessed by questionnaire at these 3 points. Averaged relative risks were estimated. Results: One 15-bp insertion/deletion in exon 4 of TIM1 was significantly related to atopy and eczema (relative risk associated with carrying at least 1 rare allele = 1.24 [1.07-1.45], P = .005; and 1.43 [1.01-2.01], P = .004, respectively). The 3 tested single nucleotide polymorphisms (SNPs) in TIM3 were significantly related to atopy and eczema. One of them, at position +4259 calculated from the translation start site, predicts a putative change in the amino acid sequence of the protein, and was the most strongly related to atopy (relative risk = 1.28 [1.12-1.47]; P = .0003). SNPs in the 5′ genomic region in ITK, which show moderate linkage disequilibrium with those in TIM3, had an independent effect on atopy. None of the polymorphisms studied was related to asthma. Conclusion: Our findings support a potential role for SNPs in TIM1, TIM3, and ITK, independent of each other, in allergic diseases. © 2005 American Academy of Allergy, Asthma and Immunology.
• Graves, P. E., Siroux, V., Guerra, S., Klimecki, W. T., & Martinez, F. D. (2005). Association of atopy and eczema with polymorphisms in T-cell immunoglobulin domain and mucin domain-IL-2-inducible T-cell kinase gene cluster in chromosome 5 q 33. The Journal of allergy and clinical immunology, 116(3), 650-6.
  More info

  The T-cell immunoglobulin domain and mucin domain (TIM) gene family and the gene for IL-2-inducible T-cell kinase (ITK), located in chromosome 5 q 33 and potentially involved in the T-cell proliferation and differentiation, are good candidate genes for allergic diseases.
• Levy, H., Raby, B. A., Lake, S., Tantisira, K. G., Kwiatkowski, D., Lazarus, R., Silverman, E. K., Richter, B., Klimecki, W. T., Vercelli, D., Martinez, F. D., & Weiss, S. T. (2005). Association of defensin beta-1 gene polymorphisms with asthma. The Journal of allergy and clinical immunology, 115(2), 252-8.
  More info

  Defensins are antimicrobial peptides that may take part in airway inflammation and hyperresponsiveness.
• Levy, H., Raby, B. A., Lake, S., Tantisira, K. G., Kwiatkowski, D., Lazarus, R., Silverman, E. K., Richter, B., Klimecki, W. T., Vercelli, D., Martinez, F. D., & Weiss, S. T. (2005). Association of defensin β-1 gene polymorphisms with asthma. Journal of Allergy and Clinical Immunology, 115(2), 252-258.
  More info

  PMID: 15696078;Abstract: Background: Defensins are antimicrobial peptides that may take part in airway inflammation and hyperresponsiveness. We characterized the genetic diversity in the defensin β-1 (DEFB1) locus and tested for an association between common genetic variants and asthma diagnosis. Methods: To identify single nucleotide polymorphisms (SNPs), we resequenced this gene in 23 self-defined European Americans and 24 African Americans. To test whether DEFB1 genetic variants are associated with asthma, we genotyped 4 haplotype-tag SNPs in 517 asthmatic and 519 control samples from the Nurses' Health Study (NHS) and performed a case-control association analysis. To replicate these findings, we evaluated the DEFB1 polymorphisms in a second cohort from the Childhood Asthma Management Program. Results: Within the NHS, single SNP testing suggested an association between asthma diagnosis and a 5′ genomic SNP (g.-1816 T>C; P = .025) and intronic SNP (IVS+692 G>A; P = .054). A significant association between haplotype (Adenine, Cytosine, Thymine, Adenine [ACTA]) and asthma (P = .024) was also identified. Associations between asthma diagnosis and both DEFB1 polymorphisms were observed in Childhood Asthma Management Program, a second cohort: g.-1816 T>C and IVS+692 G>A demonstrated significant transmission distortion (P = .05 and .007, respectively). Transmission distortion was not observed in male subjects. The rare alleles (-1816C and +692A) were undertransmitted to offspring with asthma, suggesting a protective effect, contrary to the findings in the NHS cohort. Similar effects were evident at the haplotype level: ACTA was undertransmitted (P = .04) and was more prominent in female subjects (P = .007). Conclusion: Variation in DEFB1 contributes to asthma diagnosis, with apparent gender-specific effects.
• Meza, M. M., Lizhi, Y. u., Rodriguez, Y. Y., Guild, M., Thompson, D., Gandolfi, A. J., & Klimecki, W. T. (2005). Developmentally restricted genetic determinants of human arsenic metabolism: Association between urinary methylated arsenic and CYT19 polymorphisms in children. Environmental Health Perspectives, 113(6), 775-781.
  More info

  PMID: 15929903;PMCID: PMC1257606;Abstract: We report the results of a screen for genetic association with urinary arsenic metabolite levels in three arsenic metabolism candidate genes, PNP, GSTO, and CYT19, in 135 arsenic-exposed subjects from the Yaqui Valley in Sonora, Mexico, who were exposed to drinking water concentrations ranging from 5.5 to 43.3 ppb. We chose 23 polymorphic sites to test in the arsenic-exposed population. Initial phenotypes evaluated included the ratio of urinary inorganic arsenic(III) to inorganic arsenic(V) and the ratio of urinary dimethylarsenic(V) to monomethylarsenic(V) (D:M). In the initial association screening, three polymorphic sites in the CYT19 gene were significantly associated with D:M ratios in the total population. Subsequent analysis of this association revealed that the association signal for the entire population was actually caused by an extremely strong association in only the children (7-11 years of age) between CYT19 genotype and D:M levels. With children removed from the analysis, no significant genetic association was observed in adults (18-79 years). The existence of a strong, developmentally regulated genetic association between CYT19 and arsenic metabolism carries import for both arsenic pharmacogenetics and arsenic toxicology, as well as for public health and governmental regulatory officials.
• Meza, M. M., Yu, L., Rodriguez, Y. Y., Guild, M., Thompson, D., Gandolfi, A. J., & Klimecki, W. T. (2005). Developmentally restricted genetic determinants of human arsenic metabolism: association between urinary methylated arsenic and CYT19 polymorphisms in children. Environmental health perspectives, 113(6), 775-81.
  More info

  We report the results of a screen for genetic association with urinary arsenic metabolite levels in three arsenic metabolism candidate genes, PNP, GSTO, and CYT19, in 135 arsenic-exposed subjects from the Yaqui Valley in Sonora, Mexico, who were exposed to drinking water concentrations ranging from 5.5 to 43.3 ppb. We chose 23 polymorphic sites to test in the arsenic-exposed population. Initial phenotypes evaluated included the ratio of urinary inorganic arsenic(III) to inorganic arsenic(V) and the ratio of urinary dimethylarsenic(V) to monomethylarsenic(V) (D:M). In the initial association screening, three polymorphic sites in the CYT19 gene were significantly associated with D:M ratios in the total population. Subsequent analysis of this association revealed that the association signal for the entire population was actually caused by an extremely strong association in only the children (7-11 years of age) between CYT19 genotype and D:M levels. With children removed from the analysis, no significant genetic association was observed in adults (18-79 years). The existence of a strong, developmentally regulated genetic association between CYT19 and arsenic metabolism carries import for both arsenic pharmacogenetics and arsenic toxicology, as well as for public health and governmental regulatory officials.
• Oshiro, M. M., Futscher, B. W., Lisberg, A., Wozniak, R. J., Klimecki, W. T., Domann, F. E., & Cress, A. E. (2005). Epigenetic regulation of the cell type-specific gene 14-3-3sigma. Neoplasia (New York, N.Y.), 7(9), 799-808.
  More info

  Epigenetic control participates in processes crucial in mammalian development, such as X-chromosome inactivation, gene imprinting, and cell type-specific gene expression. We provide evidence that the p53-inducible gene 14-3-3sigma is a new example of a gene important to human cancer, where epigenetic mechanisms participate in the control of normal cell type-specific expression, as well as aberrant gene silencing in cancer cells. Like a previously identified cell type-specific gene maspin, 14-3-3sigma is a p53-inducible gene; however, it participates in G2/M arrest in response to DNA-damaging agents. 14-3-3Sigma expression is restricted to certain epithelial cell types, including breast and prostate, whereas expression is absent in nonepithelial tissues such as fibroblasts and lymphocytes. In this report, we show that in normal cells expressing 14-3-3sigma, the 14-3-3sigma CpG island is unmethylated; associated with acetylated histones, unmethylated histone H3 lysine 9; and an accessible chromatin structure. By contrast, normal cells that do not express 14-3-3sigma have a methylated 14-3-3sigma CpG island with hypoacetylated histones, methylated histone H3 lysine 9, and an inaccessible chromatin structure. These findings extend the spectrum of cell type-specific genes controlled, partly, by normal epigenetic mechanisms, and suggest that this subset of genes may represent important targets of epigenetic dysregulation in human cancer.
• Burgess, J. L., Fierro, M. A., Lantz, R. C., Hysong, T. A., Fleming, J. E., Gerkin, R., Hnizdo, E., Conley, S. M., & Klimecki, W. (2004). Longitudinal decline in lung function: Evaluation of interleukin-10 genetic polymorphisms in firefighters. Journal of Occupational and Environmental Medicine, 46(10), 1013-1022.
  More info

  PMID: 15602175;Abstract: During annual medical monitoring, some firefighters are found to have rates of decline in forced expiratory volume in one second (FEV1) far exceeding their peers. Interleukin-10 (IL-10) suppresses inflammation, and single nucleotide polymorphisms (SNPs) in the IL-10 gene may confer variable susceptibility to more rapid decline in lung function. In 1204 firefighters with at least six annual FEV1 measurements, increased age and greater initial FEV1 were associated with more rapid decline in lung function. DNA collected from 379 of these firefighters was screened for IL-10 SNPs at -1117, -854, 919, 1668, and 1812. A statistically significant difference in decline in lung function was found based on genotyping at the 1668 SNP. Evaluation of gene polymorphisms regulating lung inflammation may help to explain some of the variation in rate of decline in lung function in firefighters.
• Eder, W., Klimecki, W., Lizhi, Y. u., Mutius, E. V., Riedler, J., Braun-Fahrländer, C., Nowak, D., & Martinez, F. D. (2004). Toll-like receptor 2 as a major gene for asthma in children of European farmers. Journal of Allergy and Clinical Immunology, 113(3), 482-488.
  More info

  PMID: 15007351;Abstract: Background: The finding that the prevalence of asthma and allergies Is less frequent in children raised on animal farms has led to the conjecture that exposure to microbial products modifies immune responses. The toll-like receptors (TLRs) represent an evolutionarily conserved family of innate immunity receptors with microbial molecules as ligands. Objectives: We reasoned that polymorphisms in genes encoding TLRs might modulate the protective effects observed in farming populations. Methods: Farmers' and nonfarmers' children living in rural areas in Austria and Germany and who were enrolled in the cross-sectional ALEX study were genotyped for single nucleotide polymorphisms in the TLR2 and TLR4 genes. The frequencies of asthma, allergic rhinitis, and atopic sensitization were compared between the genotypes in relation to exposure to farming and endotoxin. Results: Among farmers' children, those carrying a T allele in TLR2/-16934 compared with children with genotype AA were significantly less likely to have a diagnosis of asthma (3% vs 13%, P = .012), current asthma symptoms (3% vs 16%, P = .004), atopic sensitization (14% vs 27%, P = .023), and current hay fever symptoms (3% vs 14%, P = .01). The association between TLR2/-16934 and asthma among children of farmers was Independent of atopy. No such association was found among children from the same rural communities but not living on farms. Conclusion: Our results suggest that genetic variation in TLR2 is a major determinant of the susceptibility to asthma and allergies in children of farmers.
• Flores-Munguia, R., Siegel, E., Klimecki, W. T., & Giuliano, A. R. (2004). Performance assessment of eight high-throughput PCR assays for viral load quantitation of oncogenic HPV types. Journal of Molecular Diagnostics, 6(2), 115-124.
  More info

  PMID: 15096567;PMCID: PMC1867471;Abstract: Infection with mucosotropic human papillomavirus (HPV) is the necessary cause of cervical intraepithelial neoplasia. Several epidemiological studies suggest that HPV viral load can be a risk factor of cervical dysplasia. The purpose of the present study was to evaluate a methodology to determine HPV viral load of eight oncogenic HPV types (16, 18, 31, 39, 45, 51, 52, and 58). The quantitation assay is based on a high-throughput real-time PCR. The E6-E7 region of HPV types 16, 18, 45, and 51 were used to amplify specific DNA sequences and cloned into a plasmid vector. The constructs for HPV types 16, 18, 45, and 51, and the whole genome for HPV types 31, 39, 52, and 58 were quantitated using a limiting dilution analysis and used to create standard curves. Type-specific HPV clones were used to determine specificity, linearity, and intra- and inter-assay variation. The sensitivity of our assay covered a dynamic range of up to seven orders of magnitude with a coefficient of intra-assay variation less than 6% and the inter-assay variation less than 20%. No cross-reactivity was observed on any of the type-specific standard curves when phylogenetically close HPV types were used as templates. Our real-time PCR methodologies are highly reproducible, sensitive, and specific over a sevenfold magnitude dynamic range. Copyright © American Society for Investigative Pathology and the Association for Molecular Pathology.
• Klimecki, W., Burgess, J. L., Fierro, M. A., Lantz, R. C., Hysong, T. A., Fleming, J. E., Gerkin, R., Hnizdo, E., Conley, S. M., & Klimecki, W. -. (2004). Longitudinal decline in lung function: evaluation of interleukin-10 genetic polymorphisms in firefighters. Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine, 46(10).
  More info

  During annual medical monitoring, some firefighters are found to have rates of decline in forced expiratory volume in one second (FEV1) far exceeding their peers. Interleukin-10 (IL-10) suppresses inflammation, and single nucleotide polymorphisms (SNPs) in the IL-10 gene may confer variable susceptibility to more rapid decline in lung function. In 1204 firefighters with at least six annual FEV1 measurements, increased age and greater initial FEV1 were associated with more rapid decline in lung function. DNA collected from 379 of these firefighters was screened for IL-10 SNPs at -1117, -854, 919, 1668, and 1812. A statistically significant difference in decline in lung function was found based on genotyping at the 1668 SNP. Evaluation of gene polymorphisms regulating lung inflammation may help to explain some of the variation in rate of decline in lung function in firefighters.
• Klimecki, W., Conley, S. M., Hnizdo, E., Gerkin, R., Fleming, J. E., Hysong, T. A., Lantz, R. C., Fierro, M. A., & Burgess, J. L. (2004). Longitudinal decline in lung function: Evaluation of interleukin-10 genetic polymorphisms in firefighters. Journal of Occupational and Environmental Medicine, 46(10), 1013-1022.
• Lazarus, R., Raby, B. A., Lange, C., Silverman, E. K., Kwiatkowski, D. J., Vercelli, D., Klimecki, W. J., Martinez, F. D., & Weiss, S. T. (2004). TOLL-like receptor 10 genetic variation is associated with asthma in two independent samples. American Journal of Respiratory and Critical Care Medicine, 170(6), 594-600.
  More info

  PMID: 15201134;Abstract: TOLL-like receptor 10 (TLR10) is the most recently identified human homolog of the Drosophila TOLL protein. In humans, the TOLL-like receptors recognize pathogen-associated molecular patterns (PAMPs) as part of innate immune host defenses. Localized to chromosome 4p14, the specific ligands and functions of TLR10 are currently unknown, although it is expressed in lung and in B-lymphocytes. TLR10 is a potential asthma candidate gene because early life innate immune responses to ubiquitous inhaled allergens and PAMPs may influence asthma susceptibility. Resequencing in 47 subjects revealed a total of 78 single nucleotide polymorphisms (SNPS) (1 SNP per 106 bp) of which only 11 had been previously published. A significant association (p < = 0.02) between two SNPs (C.+1031G>A, c.+2322A>G) and physician-diagnosed asthma was observed in a case control study (517 cases, 519 control subjects) of European American subjects nested within the Nurses' Health Study cohort. The association for these same two SNPs (p ≤ 0.015) replicated in an independent family based cohort, where a measure of airway hyperresponsiveness (PC20) was also associated (p = 0.026 for c.+1031G>A). Consistent association in two independent samples and association with an intermediate phenotype provides strong support for TLR10 genetic variation contributing to asthma risk.
• Lizhi, Y. u., Martinez, F. D., & Klimecki, W. T. (2004). Automated high-throughput sex-typing assay. BioTechniques, 37(4), 662-664.
  More info

  PMID: 15517978;
• Tantisira, K., Klimecki, W. T., Lazarus, R., Palmer, L. J., Raby, B. A., Kwiatkowski, D. J., Silverman, E., Vercelli, D., Martinez, F. D., & Weiss, S. T. (2004). Toll-like receptor 6 gene (TLR6): Single-nucleotide polymorphism frequencies and preliminary association with the diagnosis of asthma. Genes and Immunity, 5(5), 343-346.
  More info

  PMID: 15266299;Abstract: Toll-like receptor 6 (TLR6) is one of a series of highly conserved innate immune receptors. We resequenced TLR6 in DNA samples from 24 African Americans, 23 European Americans, and 24 Hispanic Americans, identifying 53 SNPs, 22 with an allele frequency > 5%. Significant differences in SNP frequencies among the three populations were noted. In all, 11 SNPs caused amino-acid changes, including one with a frequency > 5% in all three populations. Utilizing this SNP (Ser249Pro), we performed exploratory nested case - control disease-association studies, including one involving 56 African Americans with asthma and 93 African American controls. The minor allele of this SNP was associated with decreased risk for asthma (odds ratio 0.38, 95% CI 0.16 - 0.87, P=0.01), an effect consistent with the known biology of the toll-like receptors. Although replication of this finding in other, larger samples is needed, variation in TLR6 may have relevance to the pathogenesis of immunologically mediated diseases. © 2004 Nature Publishing Group All rights reserved.
• Tantisira, K., Klimecki, W. T., Lazarus, R., Palmer, L. J., Raby, B. A., Kwiatkowski, D. J., Silverman, E., Vercelli, D., Martinez, F. D., & Weiss, S. T. (2004). Toll-like receptor 6 gene (TLR6): single-nucleotide polymorphism frequencies and preliminary association with the diagnosis of asthma. Genes and immunity, 5(5), 343-6.
  More info

  Toll-like receptor 6 (TLR6) is one of a series of highly conserved innate immune receptors. We resequenced TLR6 in DNA samples from 24 African Americans, 23 European Americans, and 24 Hispanic Americans, identifying 53 SNPs, 22 with an allele frequency >5%. Significant differences in SNP frequencies among the three populations were noted. In all, 11 SNPs caused amino-acid changes, including one with a frequency >5% in all three populations. Utilizing this SNP (Ser249Pro), we performed exploratory nested case-control disease-association studies, including one involving 56 African Americans with asthma and 93 African American controls. The minor allele of this SNP was associated with decreased risk for asthma (odds ratio 0.38, 95% CI 0.16-0.87, P=0.01), an effect consistent with the known biology of the toll-like receptors. Although replication of this finding in other, larger samples is needed, variation in TLR6 may have relevance to the pathogenesis of immunologically mediated diseases.
• Yu, L., Martinez, F. D., & Klimecki, W. T. (2004). Automated high-throughput sex-typing assay. BioTechniques, 37(4), 662-4.
• Lazarus, R., Klimecki, W. T., Raby, B. A., Vercelli, D., Palmer, L. J., Kwiatkowski, D. J., Silverman, E. K., Martinez, F., & Weiss, S. T. (2003). Single-nucleotide polymorphisms in the Toll-like receptor 9 gene (TLR9): Frequencies, pairwise linkage disequilibrium, and haplotypes in three U.S. ethnic groups and exploratory case-control disease association studies. Genomics, 81(1), 85-91.
  More info

  PMID: 12573264;Abstract: TLR9 is a mammalian Toll-like receptor homologue that appears to function as an innate immune pattern recognition protein for motifs that are far more common in bacterial than in mammalian DNA. The gene was sequenced in 71 subjects from three self-identified U.S. ethnic groups to identify single-nucleotide polymorphisms (SNPs). A total of 20 SNPs were found of which only 20% were in the public dbSNP database. Four SNPs were relatively common in all three ethnic samples. Using these four SNPs, seven distinct haplotypes were statistically inferred, of which four accounted for 75% or more chromosomes. These four haplotypes could be distinguished from each other by the alleles of two SNPs (-1237 and 2848). Five exploratory nested case-control disease-association studies (asthma, DVT, MI, and COPD in European Americans and asthma in African Americans) were performed by genotyping DNA collected from four ongoing cohort studies. There was evidence suggesting increased risk for asthma with a C allele at -1237 (odds ratio 1.85, 95%CI 1.05 to 3.25) among European Americans (genotypes available from 67 cases and 152 controls). No other significant disease associations were detected. Replication of this finding in other, larger samples is needed. This study suggests that there is substantial diversity in human TLR9, possibly associated with asthma in Europeans but not African Americans. No association was detected with three other diseases potentially related to innate immunity. © 2003 Elsevier Science (USA). All rights reserved.
• Lizhi, Y. u., Kalla, K., Guthrie, E., Vidrine, A., & Klimecki, W. T. (2003). Genetic variation in genes associated with arsenic metabolism: Glutathione S-transferase omega 1-1 and purine nucleoside phosphorylase polymorphisms in European and indigenous Americans. Environmental Health Perspectives, 111(11), 1421-1427.
  More info

  PMID: 12928150;PMCID: PMC1241635;Abstract: Individual variability in human arsenic metabolism has been reported frequently in the literature. This variability could be an underlying determinant of individual susceptibility to arsenic-induced disease in humans. Recent analysis revealing familial aggregation of arsenic metabolic profiles suggests that genetic factors could underlie interindividual variation in arsenic metabolism. We screened two genes responsible for arsenic metabolism, human purine nucleoside phosphorylase (hNP), which functions as an arsenate reductase converting arsenate to arsenite, and human glutathione S-transferase omega 1-1 (hGSTO1-1), which functions as a monomethylarsonic acid (MMA) reductase, converting MMA(V) to MMA(III), to develop a comprehensive catalog of commonly occurring genetic polymorphisms in these genes. This catalog was generated by DNA sequencing of 22 individuals of European ancestry (EA) and 24 individuals of indigenous American (IA) ancestry. In hNP, 48 polymorphic sites were observed, including 6 that occurred in exons, of which 1 was nonsynonymous (G51S). One intronic polymorphism occurred in a known enhancer region. In hGSTO1-1, 33 polymorphisms were observed. Six polymorphisms occurred in exons, of which 4 were nonsynonymous. In contrast to hNP, in which the IA group was more polymorphic than the EA group, in hGSTO1-1 the EA group was more polymorphic than the IA group, which had only 1 polymorphism with a frequency > 10%. Populations representing genetic admixture between the EA and IA groups, such as Mexican Hispanics, could vary in the extent of polymorphism in these genes based upon the extent of admixture. These data provide a framework in which to conduct genetic association studies of these two genes in relevant populations, thereby allowing hNP and hGSTO1-1 to be evaluated as potential susceptibility genes in human arsenicism.
• Lazarus, R., Klimecki, W. T., Palmer, L. J., Kwiatkowski, D. J., Silverman, E. K., Brown, A., Martinez, F., & Weiss, S. T. (2002). Single-nucleotide polymorphisms in the interleukin-10 gene: Differences in frequencies, linkage disequilibrium patterns, and haplotypes in three United States ethnic groups. Genomics, 80(2), 223-228.
  More info

  PMID: 12160736;Abstract: Interleukin-10 (IL-10) is a cytokine that seems to function as a downregulator of the innate (nonadaptive) immune system. Approximately three-quarters of interindividual variability in human IL-10 levels has been attributed to genetic variation, and there is evidence suggesting a potential role for IL-10 in a range of human diseases. To provide a basis for haplotype analysis and future disease association studies, we characterized genetic variation in IL10 by sequencing all exons, and 2.5 kb of the 5′- and the 3′-flanking region in a panel of DNA samples from 24 African Americans, 23 European Americans, and 24 Hispanic Americans. The region sequenced was found to contain 28 single-nucleotide polymorphisms (SNPs), 16 with frequency > 2% and 14 with frequency > 5%. All SNPs with frequency > 5% were present in subjects from all three populations. No SNP caused amino acid changes. Differences in pairwise linkage-disequilibrium (LD) patterns and in SNP and haplotype frequency distributions among the three populations may be of potential importance for disease association studies.
• Lazarus, R., Vercelli, D., Palmer, L. J., Klimecki, W. J., Silverman, E. K., Richter, B., Riva, A., Ramoni, M., Martinez, F. D., Weiss, S. T., & Kwiatkowski, D. J. (2002). Single nucleotide polymorphisms in innate immunity genes: Abundant variation and potential role in complex human disease. Immunological Reviews, 190, 9-25.
  More info

  PMID: 12493003;Abstract: Under selective pressure from infectious microorganisms, multicellular organisms have evolved immunological defense mechanisms, broadly categorized as innate or adaptive. Recent insights into the complex mechanisms of human innate immunity suggest that genetic variability in genes encoding its components may play a role in the development of asthma and related diseases. As part of a systematic assessment of genetic variability in innate immunity genes, we have thus far have examined 16 genes by resequencing 93 unrelated subjects from three ethnic samples (European American, African American and Hispanic American) and a sample of European American asthmatics. Approaches to discovering and understanding variation and the subsequent implementation of disease association studies are described and illustrated. Although highly conserved across a wide range of species, the innate immune genes we have sequenced demonstrate substantial interindividual variability predominandy in the form of single nucleotide polymorphisms (SNPs). Genetic variation in these genes may play a role in determining susceptibility to a range of common, chronic human diseases which have an inflammatory component. Differences in population history have produced distinctive patterns of SNP allele frequencies, linkage disequilibrium and haplotypes when ethnic groups are compared. These and other factors must be taken into account in the design and analysis of disease association studies.
• Raby, B. A., Klimecki, W. T., Laprise, C., Renaud, Y., Faith, J., Lemire, M., Greenwood, C., Weiland, K. M., Lange, C., Palmer, L. J., Lazarus, R., Vercelli, D., Kwiatkowski, D. J., Silverman, E. K., Martinez, F. D., Hudson, T. J., & Weiss, S. T. (2002). Polymorphisms in toll-like receptor 4 are not associated with asthma or atopy-related phenotypes. American Journal of Respiratory and Critical Care Medicine, 166(11), 1449-1456.
  More info

  PMID: 12406828;Abstract: Toll-like receptor 4 (TLR4) is the principal receptor for bacterial endotoxin recognition, and functional variants in the gene confer endotoxin-hyporesponsiveness in humans. Furthermore, there is evidence that endotoxin exposure during early life is protective against the development of atopy and asthma, although this relationship remains poorly understood. It is therefore possible that genetic variation in the TLR4 locus contributes to asthma susceptibility. In this study we characterize the genetic diversity in the TLR4 locus and test for association between the common genetic variants and asthma-related phenotypes. In a cohort of 90 ethnically diverse subjects, we resequenced the TLR4 locus and identified a total of 29 single nucleotide polymorphisms. We assessed five common polymorphisms for evidence of association with asthma in two large family-based cohorts: a heterogeneous North American cohort (589 families), and a more homogenous population from northeastern Quebec, Canada (167 families). Using the transmission-disequilibrium test, we found no evidence of association for any of the polymorphisms tested, including two functional variants. Furthermore, we found no evidence for association between the TLR4 variants and four quantitative intermediate asthma- and atopy-related phenotypes. Based on these results, we found no evidence that genetic variation in TLR4 contributes to asthma susceptibility.
• Klimecki, W. T., Borchers, A. H., Egbert, R. E., Nagle, R. B., Carter, D. E., & Bowden, G. T. (1997). Effects of acute and chronic arsenic exposure of human-derived keratinocytes in an in vitro human skin equivalent system: A novel model of human arsenicism. Toxicology in Vitro, 11(1-2), 89-98.
  More info

  PMID: 20654299;Abstract: An organotypic culture (OTC) of a human keratinocyte cell line (HaCaT) over a human fibroblast-embedded collagen gel was used to model human epidermis in arsenicism, a syndrome that currently lacks valid experimental models. Keratinocytes were exposed acutely or chronically to a mixture of arsenate (0.5 μM), monomethylarsonic acid (MMA; 0.5 μM) and dimethylarsinic acid (DMA; 1.5 μM), or to the individual components of the mixture. OTCs were assayed for microscopic morphology, the proliferating cell marker, Ki-67, labelling and cytokeratin expression. Acute exposures resulted in an epidermal phenotype that accurately modelled early human lesions, including hyperkeratosis, acanthosis and keratin 16 induction. Chronic exposures resulted in a de-differentiated epidermal phenotype with focal nests of keratinocytes growing into the collagen gel. The keratin 8/18 pair was induced by either acute or chronic arsenic exposure, as was the proliferating cell marker, Ki-67. Exposure of keratinocytes to individual arsenic compounds demonstrated that all arsenic mixture-induced changes could be duplicated by exposure to arsenate alone. In contrast, MMA and DMA were inactive. This study establishes OTC as a useful model of arsenicism, and implicates inorganic arsenic as the ultimate carcinogen.
• Klimecki, W. T., & Carter, D. E. (1995). Arsine toxicity: Chemical and mechanistic implications. Journal of Toxicology and Environmental Health, 46(4), 399-409.
  More info

  PMID: 8523468;
• Klimecki, W. T., Taylor, C. W., & Dalton, W. S. (1995). Inhibition of cell-mediated cytolysis and P-glycoprotein function in natural killer cells by verapamil isomers and cyclosporine a analogs. Journal of Clinical Immunology, 15(3), 152-158.
  More info

  PMID: 7559918;Abstract: We have previously shown that among normal leukocytes, CD56+ and CD8+ cells express relatively high levels of P-glycoprotein (P-gp), a transmembrane efflux pump. While the physiologic significance of P-gp expression in leukocytes is unknown, the relatively high levels of P-gp in CD56+ and CD8+ cells suggest that P-gp may function in cell-mediated cytolysis. To explore this possibility we examined the effect of four inhibitors of P-gp efflux [(R)-verapamil (R-ver), (S) -verapamil (S-ver), cyclosporine A (CsA), and PSC833 (PSC)] on both the inhibition of natural killer cell (NK) function and on P-gp efflux. NK function was assayed by measuring the lysis of51Cr-labeled K562 target cells in the presence and absence of inhibitors. All four P-gp efflux inhibitors inhibited NK-mediated cytolysis in a dose-dependent manner. The stereoisomers of verapamil were more potent inhibitors of cell-mediated cytolysis than the cyclosporines CsA and PSC. In contrast, CsA and PSC were more potent as inhibitors of P-gp-mediated rhodamine 123 dye efflux than the verapamil isomers. Both CsA and PSC maximally inhibited P-gp efflux at 3 μM, but only minimally inhibited cell-mediated cytolysis. The verapamil compounds demonstrated closer correlation between efflux inhibition and inhibition of NK-mediated cytolysis. The data support a role for P-gp in NK-mediated cytolysis; however, these studies also suggest that the NK cytolytic process is multifaceted and that inhibition of the P-gp-mediated efflux mechanism only partially abrogates this process. © 1995 Plenum Publishing Corporation.
• Klimecki, W. T., Klimecki, W. T., Futscher, B. W., & Dalton, W. S. (1994). Effects of ethanol and paraformaldehyde on RNA yield and quality.. BioTechniques, 16(6), 1021-3.
• Klimecki, W. T., Klimecki, W. T., Grogan, T. M., Futscher, B. W., & Dalton, W. S. (1994). P-glycoprotein expression and function in circulating blood cells from normal volunteers. Blood, 83(9), 2451-2458. doi:10.1182/blood.v83.9.2451.2451
  More info

  In contrast to its clearly defined role as a multidrug efflux pump in neoplastic cells, the physiologic function of P-glycoprotein (P-gly) in normal cells is unclear. Recent reports identifying P-gly in normal blood and bone marrow suggest that hematopoietic development or function may be dependent on P-gly. To understand the normal function of P-gly in the blood, its level of expression and function must first be quantitated relative to a known standard. In this study, P-gly, MDR1 gene expression, and P-gly function were quantitated in normal leukocytes. P-gly and MDR1 expression were analyzed in individual leukocyte lineages (T-helper, T-suppressor, monocyte, granulocyte, B-lymphocyte, NK cell) from normal volunteers. P-gly on the cell surface was detected by fluorescent double-labeling for lineage (CD4, CD8, CD14, CD15, CD19, CD56, respectively) and P-gly (MRK16) with analysis by flow cytometry and in some cases immunoblot analysis. MDR1 mRNA analysis on purified lineages was performed using quantitative reverse transcription-polymerase chain reaction. P-gly function was determined for each lineage using dual-labeling for lineage and P-gly substrate (rhodamine 123). The P-gly expressing human myeloma cell line, 8226/Dox6, was used as a reference of comparison for levels of P-gly, MDR1 mRNA, and function. CD56+ cells expressed the highest levels of MDR1 mRNA followed by CD8+ > CD4+ approximately equal to CD15+ > CD19+ > CD14+, with percentage values relative to Dox6 of 49%, 17%, 8%, 8%, 4%, and 2%, respectively. The assays for P-gly immunofluorescence and function correlated well with mRNA analysis except for CD15+ cells (granulocytes), which showed a moderate MDR1 mRNA level with a lack of both function and surface P-gly staining. Granulocyte membranes did show P-gly on immunoblot analysis when probed with either C219 or JSB1. We conclude that (1) P-gly and the MDR1 mRNA are expressed in normal leukocytes, (2) this P-gly expression is lineage specific with relatively high levels among CD56+ cells, and (3) the expression of P-gly in granulocytes is not associated with transport of the P-gly substrate, rhodamine 123, out of the cell.
• Klimecki, W. T., List, A. F., Klimecki, W. T., Futscher, B. W., Dalton, W. S., & Abbaszadegan, M. R. (1994). Analysis of multidrug resistance-associated protein (MRP) messenger RNA in normal and malignant hematopoietic cells.. Cancer research, 54(17), 4676-9.
  More info

  The multidrug resistance-associated protein (MRP) gene is a member of the ATP-binding cassette transporter gene superfamily and may be partially responsible for clinical drug resistance. Reverse transcriptase-polymerase chain reaction was used to measure MRP mRNA in normal hematopoietic cells from bone marrow and peripheral blood as well as patients with high risk acute myelocytic leukemia and multiple myeloma. All normal peripheral blood cells, regardless of cell lineage (CD4, CD8, CD14, CD15, CD19, CD56), expressed a similar basal level of MRP mRNA. Specimens from bone marrow containing mixed lineages also expressed a similar basal level of MRP expression. In patients with acute myelocytic leukemia, 10 of 12 (83%) of the specimens had detectable MRP mRNA, but the level of expression was similar to that of normal blood cells and low compared to a cell line known to overexpress MRP (H69/AR). All myeloma patients (12 of 12) had detectable MRP mRNA expression at levels comparable to normal peripheral blood and bone marrow cells. We conclude that MRP is commonly expressed in normal hematopoietic cells as well as certain hematopoietic malignancies. The therapeutic relevance of MRP expression is unknown, but these studies emphasize the importance of measuring MRP expression in normal cells as a point of reference and comparison for detection in malignant cells. We also recommend obtaining sequential specimens from patients, which may reveal an increased expression of MRP from baseline as the disease progresses and becomes resistant.

Presentations

• Pemberton, J. E., Polt, R. L., Schwartz, S. D., Maier, R. M., & Klimecki, W. (2016, Summer). Biosynthetic and Bio-inspired Glycolipid Surfactants: Properties, Biodegradability, and Toxicity. 20th Annual Green Chemistry & Engineering Conference. Portland, OR: American Chemical Society Green Chemistry Institute.
• Beamer, P. I., Beamer, P. I., Loh, M. M., Loh, M. M., Lothrop, N. Z., Lothrop, N. Z., Sugeng, A. J., Sugeng, A. J., Wilkinson, S. T., Wilkinson, S. T., Cox, M. L., Cox, M. L., Klimecki, W., & Klimecki, W. (2015, Spring). Linking Exposure & Translational Science: A Community-Engaged Project near a Legacy Mine.. NIEHS Environmental Health Sciences Core Centers Meeting. Tucson, AZ: NIEHS.
  More info

  Beamer, P.I., Loh, M., Lothrop, N.**, Sugeng, A.**, Wilkinson, S.T., Cox, M., and W. Klimecki. Presented at in Tucson, AZ
• Beamer, P. I., Loh, M. M., Lu, Z., Sugeng, A., Lothrop, N., Billheimer, D., & Klimecki, W. (2015, October). Association of Children’s Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media. International Society of Exposure Science. Henderson, NV.
  More info

  2015 Beamer, P., Loh, M., Lu, Z., Sugeng, A.**, Lothrop, N.**, Billheimer, D., Klimecki, W. “Association of Children’s Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media.” International Society of Exposure Science, Las Vegas, NV.
• Pemberton, J. E., Szabo, L., Hogan, D. E., Malm, S., Palos-Pacheco, R., Tian, F., Kegel, L. L., Fathi, A., Gonzalez, R., Eismin, R. J., Coss, C. S., Hanrahan, D. J., Hunjan, A., Robin, P., Maier, R. M., & Klimecki, W. (2015, Summer). Quantitative Structure-Activity Relationships for Predicting Toxicity and Biodegradability of Biosynthetic and Bio-inspired Glycolipid Surfactants. 250th American Chemical Society National Meeting & Exposition. Boston, MA.
• Van Horne, Y. O., Bell, M. L., Lothrop, N. Z., Wilkinson, S., Klimecki, W., Loh, M. M., Sugeng, A. J., & Beamer, P. (2015, October). Dietary predictors of urinary arsenic concentration for children living in a rural Arizona community. International Society of Exposure Science. Henderson, NV.
• Van Horne, Y. O., Canales, R. A., Lothrop, N. Z., Loh, M. M., Klimecki, W., Sugeng, A. J., & Beamer, P. (2015, October). Influence of household and housing factors on dust levels inside residencies near a legacy mine. International Society of Exposure Science.
• Loh, M. M., Lothrop, N. Z., Sugeng, A., Felix, O. I., Betterton, E. A., Saez, A. E., Klimecki, W., Wilkinson, S. T., & Beamer, P. I. (2014, October). Environmental Exposures to Children at a Legacy Mine Site. International Society of Exposure Science 24th Annual Meeting. Cincinnati, OH: International Society of Exposure Science.
• Loh, M. M., Sugeng, A., Lothrop, N., Klimecki, W., Cox, M., Wilkinson, S., & Beamer, P. I. (2014, March). Multi-media Exposure to Metals Near a Mine Tailings Site. Society of Toxicology. Phoenix, Arizona.
• Sugeng, A., Beamer, P. I., Lothrop, N. Z., Wilkinson, S. T., Klimecki, W., & Loh, M. M. (2014, November). Assessing the Potential for Metals Transport into Homes Surrounding a Legacy Mining Superfund Site. Superfund Research Program Annual Meeting. San Jose, CA.
• Beamer, P. I., Sugeng, A. J., Lothrop, N., Klimecki, W. -., Wilkinson, S., & Loh, M. M. (2013, August). Airborne metal concentrations measured using passive samplers in community near contaminated mine tailings. Presented at the Joint Conference for International Society of Exposure Science, International Society of Environmental Epidemiology, and International Society of Indoor Air Quality, Basel Switzerland. Basel, Switzerland.
• Beamer, P. I., Sugeng, A., Lothrop, N., Cox, M., Klimecki, W. -., Wilkinson, S. T., & Loh, M. M. (2013, August). Airborne metal concentrations measured using passive samplers in a community near contaminated mine tailings. Environment and Health – Bridging South, North, East and West. Basel, Switzerland.
• Sugeng, A., Klimecki, W. -., Beamer, P. -., Lothrop, N., Cox, M., Wilkinson, S., & Loh, M. M. (2013, October). Assessing Metal Exposure in the Community Surrounding the Iron King Superfund Site. Superfund Research Program Annual Meeting. Baton Rouge, LA: NIEHS.

Poster Presentations

• Karnes, J. H., Klimecki, W., Quinn, D., Nix, D. E., Campbell, P., & Larriva, P. M. (2017, October). Efficacy of personal pharmacogenomic testing as an educational tool in the pharmacy curriculum. American College of Clinical Pharmacy Annual Meeting. Phoenix, AZ.
• Lothrop, N. Z., Wilkinson, S. T., Klimecki, W., Beamer, P. I., Sugeng, A., & Loh, M. M. (2014, October). Developing Community-Engaged Results Report-back Materials for an Environmental Exposure Study in a Rural Arizona Community near a Superfund Site. International Society of Exposure Science 24th Annual Meeting. Cincinnati, OH: International Society of Exposure Science.
• Chen, Z. -., Chen, Z. -., Grant, A., Grant, A., Klimecki, W. -., Klimecki, W. -., Wright, N., Wright, N., Hu, C. -., Hu, C. -., Wright, J., Wright, J., Going, S. B., Going, S. B., Nicholas, J. S., Nicholas, J. S., Thompson, P., Thompson, P., Chen, Z. -., , Grant, A., et al. (2013, Fall). Possible pathways for the association of appendicular skeletal muscle mass with leptin, insulin, myoglobin and inflammatory Markers. The American Society for Bone and Mineral Research (ASBMR) 2013 Annual Meeting. Baltimore, MD.
  More info

  Zhao Chen, Andriene Grant, Walt Klimecki, Nicole C. Wright, Jennifer Bea, Scott Going, J. Skye Nicholas, Patricia Thompson. Possible pathways for the association of appendicular skeletal muscle mass with leptin, insulin, myoglobin and inflammatory markers (poster presentation). The American Society for Bone and Mineral Research Annual Meeting, Oct 2-7, 2013. Baltimore, Maryland USA.
• Klimentidis, Y. C., Klimentidis, Y. C., Thompson, P., Thompson, P., Klimecki, W. -., Klimecki, W. -., Hu, C. -., Hu, C. -., Wu, G., Wu, G., Bea, J., Bea, J., Nicholas, J. S., Nicholas, J. S., Allison, D., Allison, D., Chen, Z. -., Chen, Z. -., Klimentidis, Y. C., , Thompson, P., et al. (2013, Fall). Genetic variants in CAPN3 and ACVR2B are associated with lean body mass in postmenopausal women. The American Society for Bone and Mineral Research (ASBMR) 2013 Annual Meeting. Baltimore, MD.
  More info

  Yann Klimentidis, Patricia Thompson, Walter T. Klimecki, Chengcheng Hu, Guanglin Wu, Jennifer Wright Bea, Skye Nicholas, CHARGE Consortium Musculoskeletal Working Group, Zhao Chen Genetic variants in CAPN3 and ACVR2B are associated with lean body mass in postmenopausal women. (poster presentation) The American Society for Bone and Mineral Research Annual Meeting, Oct 2-7, 2013. Baltimore, Maryland USA.
• Loh, M. M., Sugeng, A., Lothrop, N., Klimecki, W. -., Cox, M., Wilkinson, S., & Beamer, P. -. (2013, August). Exposure to Metals in Environmental Media Near a Mine Tailings Site. Joint Conference for the International Society of Exposure Science, the International Society of Indoor Air Quality and Climate, and the International Society of Environmental Epidemiology. Basel, Switzerland: International Society for Exposure Science.
• Loh, M. M., Sugeng, A., Lothrop, N., Klimecki, W. -., Cox, M., Wilkinson, S., & Beamer, P. -. (2013, Sumer). Multimedia Exposure Metals Near a Mine Tailings Site. Joint Conference for International Society of Exposure Science, International Society of Environmental Epidemiology, and International Society of Indoor Air Quality. Basel Switzerland.
• Lothrop, N., Sugeng, A. J., Beamer, P. -., Klimecki, W. -., Cox, M., Wilkinson, S. T., & Loh, M. M. (2013, August). Relationship of Arsenic Concentration in Residential Yard Soil, Home Location, and Topography in a Community near a Superfund Site. Joint Conference for International Society of Exposure Science, International Society of Environmental Epidemiology, and International Society of Indoor Air Quality. Basel, Switzerland.
• Sugeng, A., Beamer, P. -., Klimecki, W. -., Lothrop, N., Cox, M., Wilkinson, S., & Loh, M. M. (2013, August). Comparison of Inter-Home and Intra-Home Variance of Arsenic in Children’s Urine for Households Near a Hazardous Waste Site. Environment and Health – Bridging South, North, East and West. Basil, Switzerland.
• Sugeng, A., Beamer, P. -., Lothrop, N., Klimecki, W. -., Cox, M., Wilkinson, S., & Loh, M. M. (2013, August). Comparison of Inter-Home and Intra-Homes Variance of Arsenic in Children's Urine for Households Near a Hazardous Waste Site. Joint Conference for the International Society of Exposure Science, the International Society of Indoor Air Quality and Climate, and the International Society of Environmental Epidemiology. Basel, Switzerland: International Society for Exposure Science.
• Sugeng, A., Beamer, P. I., Klimecki, W., Cox, M., Wilkinson, S. T., & Loh, M. M. (2013, August). Relationship between Arsenic Concentration in Residential Yard Soil, Home Location, and Topography in a Community near a Superfund Site. Environment and Health – Bridging South, North, East and West. Basel, Switzerland: ISEE, ISES and ISIAQ.
  More info

  The Iron King Mine and Humboldt Smelter Superfund Site is located in northern Arizona and is characterized by piles of minetailings and smelter ash adjacent to the Town of Dewey-Humboldt, AZ (2010 population: 3,984). Residential exposure to metals in yard soil deposited via windblown dust from the Site is a concern because of the Site&amp;#8217;s immediate proximity to homes and climate conditions, which may blow dust from the tailings and into Town. Arsenic concentrations over 1,000 mg/kg arecommon on the Site, with levels up to 4,400 mg/kg. Exposure to arsenic can increase the risk of developing lung, skin, bladder, breast, prostate, kidney, and liver cancer as well as digestive tract and dermal health issues. Adults and kids may ingest arsenic in soil blown in from the Site whileplaying or working in the yard. Also, children may be at higher risk ofaccidentally ingesting soil because of behaviors like playing outside on the ground and the tendency to taste items they find that may be coated with soil or dust.
• Sugeng, A., Klimecki, W. -., Beamer, P. -., Lothrop, N., Cox, M., Wilkinson, S., & Loh, M. M. (2013, October). Assessing Metal Exposure in the Community Surrounding the Iron King Superfund Site.. Superfund Research Program Annual Meeting. Baton Rouge.
• Sugeng, A., Klimecki, W. -., Beamer, P. -., Lothrop, N., Cox, M., Wilkinson, S., Loh, M. M., Sugeng, A., Klimecki, W. -., Beamer, P. -., Lothrop, N., Cox, M., Wilkinson, S., & Loh, M. M. (2013, May). Assessing Metal Exposure in the Community Surrounding the Iron King Superfund Site. Airborne Mineral Dust Contaminants: Impact on Human Health and the Environment Conference. Tucson, AZ: Atmospheric Scientists.