Environmental exposures in utero and microRNA

PURPOSE OF REVIEW Understanding the effects of in-utero exposures to environmental agents is of great importance as the resulting deregulation of biological processes can affect both fetal development and health outcomes that manifest later in life. Due to their established role in developmental processes and inherent stability ex vivo, microRNAs (miRNAs) have emerged as attractive candidates to explore the impact of such exposures during this critical window of susceptibility. In this review, we summarize the findings of studies assessing miRNAs as markers of in-utero environmental exposures and as candidates for the molecular basis through which these exposures exert their influence on children's health. RECENT FINDINGS To date, miRNA expression profiles due to various in-utero environmental exposures, including xenochemicals, endogenous factors, and nutritional status, have been reported. SUMMARY While the validity of the identified exposure-specific miRNA profiles remains to be established, the findings thus far do raise interesting questions worth addressing in future studies. Gaps that remain to be addressed include linking specific in-utero exposures to subsequent health outcomes based on established miRNA expression profiles and experimentally validating putative downstream targets of the deregulated miRNAs.