Long-term exposure to "low-dose" bisphenol A decreases mitochondrial DNA copy number, and accelerates telomere shortening in human CD8 + T cells

Sci Rep. 2020 Sep 25;10(1):15786. doi: 10.1038/s41598-020-72546-x.

Abstract

Exposure to the endocrine disruptor bisphenol A (BPA) has been linked with immune disorders and increased tumour risk. Our previous work in activated human peripheral blood mononuclear cells demonstrated that exposure to "low-dose" BPA diminished telomerase activity via an ER/GPR30-ERK signalling pathway. Leukocyte telomerase activity and telomere maintenance are crucial for normal immune function and homeostasis. We thus here further studied the effects of BPA on human T cell subpopulations. Exposure to 0.3-3 nM BPA, i. e. at doses in the realm of human exposure, notably reduced telomerase activity in activated CD8 + T but not CD4 + T cells in a non-monotonic response pattern as determined by the TRAP-ELISA assay. Under long-term BPA exposure, significant telomere length shortening, reduction in mitochondrial DNA copy number, cell proliferation and IFN-γ as well as hTERT protein suppression could be observed in CD8 + lymphocytes, as analysed by qRT-PCR, flow cytometry and western blot analysis. This study extends our previous in vitro findings that "low-dose" BPA has potential negative effects on healthy human cytotoxic T cell response. These results might merit some special attention to further investigate chronic BPA exposure in the context of adaptive immune response dysfunction and early onset of cancer in man.

MeSH terms

  • Adult
  • Benzhydryl Compounds / pharmacology*
  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / metabolism*
  • Cell Proliferation
  • Cells, Cultured
  • DNA Copy Number Variations*
  • DNA, Mitochondrial / genetics*
  • Dose-Response Relationship, Drug
  • Free Radical Scavengers / pharmacology
  • Humans
  • Leukocytes, Mononuclear / drug effects
  • Leukocytes, Mononuclear / metabolism*
  • Male
  • Phenols / pharmacology*
  • Signal Transduction
  • Telomere / genetics*
  • Telomere Shortening / drug effects*
  • Time Factors
  • Young Adult

Substances

  • Benzhydryl Compounds
  • DNA, Mitochondrial
  • Free Radical Scavengers
  • Phenols
  • bisphenol A