Accelerated telomere shortening in peripheral blood lymphocytes after occupational polychlorinated biphenyls exposure

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• 作者：Susanne Ziegler ; Thomas Schettgen ; Fabian Beier ; Stefan Wilop…
• 关键词：Polychlorinated biphenyls ; Telomere ; Lymphocytes ; Occupational exposure
• 刊名：Archives of Toxicology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：91
• 期：1
• 页码：289-300
• 全文大小：1262KB
• 刊物主题：Pharmacology/Toxicology; Occupational Medicine/Industrial Medicine; Environmental Health; Biomedicine, general;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-0738
• 卷排序：91

文摘

Polychlorinated biphenyls (PCBs) are organochlorine pollutants with a worldwide dissemination. We examined telomere length (TL) in peripheral blood cells of 207 individuals with a high body burden of PCBs due to occupational exposure in a transformer recycling company. Whereas TL in granulocytes was not affected, the age-adjusted TL in lymphocytes (∆TL_Lymph) of exposed individuals was significantly shorter than expected [−0.77 kb; 95 % confidence interval (CI) −0.9316; −0.6052; p = 0.0001]. PCB exposure did not affect lymphocyte numbers or T cell receptor excision circle (TREC) levels in T cells, suggesting that PCBs cause loss of telomeric DNA in T cells due to their metabolic activation and antigen-stimulated proliferation. In support of this hypothesis, blood plasma levels of PCB-exposed individuals inhibited expression of telomerase, the telomere elongating enzyme in vitro in antigen-specific T cell proliferation assays. 3-OH-CB28, a downstream metabolite of the lower chlorinated PCB-28 in PCB-exposed individuals (mean blood plasma concentration: 0.185 ± 0.68 ng/mL), inhibited telomerase gene expression within 48 h of incubation in lymphoproliferative assays starting at a concentration of 0.27–6.75 µg/mL and accelerated telomere shortening in long-term cell culture experiments. Accelerated telomere shortening due to PCB exposure may lead to limitations of cell renewal and clonal expansion of lymphocyte populations. As PCB-related immune dysfunctions have been linked to increased susceptibility to infectious diseases and increased risk of cancer, our data provide a possible explanation, for how PCBs could promote infections and cancer through limiting immune surveillance.