Bruce Blumberg, Ph.D., Toshihiro Shioda, M.D., Ph.D.
University of California Irvine, Massachusetts General Hospital
In a new study, NIEHS grantees showed that early exposure to tributyltin (TBT) in mice can increase fat storage in their unexposed descendants. The new findings suggest that obesity involves more than a simple imbalance in calories taken in and those used.
TBT, an anti-fouling agent that is also formed during production of the plastic polyvinyl chloride, has been classified as an obesogen because it disrupts normal development and fat metabolism. The researchers used mice to find out if early-life exposure to TBT could alter metabolism in a way that predisposed exposed mice as well as their descendants to store more fat. The researchers exposed female mice to TBT throughout pregnancy and lactation and found that unexposed male descendants born three generations later were more prone to obesity when the fat in their diet was increased. They also found that the ancestral TBT exposure induced global changes in DNA methylation and altered expression of genes involved in metabolism. Further analyses produced findings suggesting that ancestral TBT exposure induced changes in how DNA was packaged and that these changes could be passed on to offspring.
According to the researchers, the study results point to a need to further study obesogen-related epigenetic contributions to obesity in people.
Citation: Chamorro-Garcia R, Diaz-Castillo C, Shoucri BM, Kach H, Leavitt R, Shioda T, Blumberg B. 2017. Ancestral perinatal obesogen exposure results in a transgenerational thrifty phenotype in mice. Nat Commun. 8(1):2012; doi:10.1038/s41467-017-01944-z [Online 08 December 2017].