Terumi Midoro-Horiuti, M.D., Ph.D.
University of Texas Medical Branch Galveston
According to a new NIEHS-funded study, bisphenol A (BPA) exposure activated an immune response in mice that lasted for at least three generations. The authors suggested that the inheritance occurred via epigenetic changes, which are changes in gene expression that do not alter the underlying genetic code.
The researchers exposed pregnant mice to levels of BPA similar to what humans might experience. The first generation of offspring were only exposed in utero. The next two generations had no exposure. Comparing BPA-exposed and control animals, they evaluated levels of two kinds of proteins — those related to immune response and DNA-binding proteins called histones, which play a role in epigenetic changes.
BPA-exposed mice and their offspring had higher expression of some proteins involved in the innate immune system compared with control mice. The innate immune system is important in responding to viruses and allergic diseases. The exposed mice also had higher levels of enzymes that modify histones. In human cells, the researchers observed that BPA exposure increased expression of some of the same proteins regulating the immune response and histones.
The findings indicate that BPA can activate an innate immune response by increasing expression of important proteins and can increase expression of enzymes that promote epigenetic histone modifications. According to the authors, their results point to epigenetic inheritance as a possible mechanism by which immune response persisted in the offspring of BPA-exposed mice, even without direct exposure to BPA themselves.
Citation: Sowers ML, Tang H, Tian B, Goldblum R, Midoro-Horiuti T, Zhang K. 2020. Bisphenol A activates an innate viral immune response pathway. J Proteome Res 9(2):644–654.