Epigenetic regulation of gene expression in response to environmental exposures: From bench to model

Environmental exposure can cause changes in epigenetic regulation, namely histone modifications, DNA methylation, RNA modifications, and non-coding RNA (ncRNA) expression; studies of these changes provide insights into the link between environmental exposure and gene expression. Generally, histone acetylation modification is related to gene activation, whereas DNA hypermethylation is related to gene silencing. RNA modifications regulate gene expression by mediating RNA metabolism. NcRNAs, such as microRNA, mediate the epigenetic regulation of gene expression by guiding argonaute-containing complexes to complementary nascent RNA scaffolds. To date, several studies have characterized the molecular mechanisms involved in the epigenetic regulation of gene expression by environmental exposure. This review combines current research and a summary of our previous work to outline the epigenetic regulation of gene expression during environmental exposure and discusses epigenetic regulatory interactions to propose a new model for environmental exposure-mediated changes in epigenetic regulation and gene expression. We also discuss the dynamic relationship between environmental exposure and gene expression. (c) 2021 Elsevier B.V. All rights reserved.