Epigenetic mechanisms in maternal-fetal crosstalk: inter- and trans-generational inheritance.

Epigenetics as a composite language capable of translating signals from the environment into heritable DNA modifications is revolutionizing the approach to biology and medicine. In the field of human reproductive physiology, many epigenetic marks have been decoded in the different stages of development, from gametogenesis to embryo development, pregnancy and its maintenance. These epigenetics marks are mainly ascribable to DNA methylation/demethylation processes, histone modifications, and non-coding RNAs mediated signals. Epigenetic modifiers such as DNA methyltransferases (DNMTs) and Ten-eleven translocation (TET) enzymes are involved in gene expression regulation by modifying the DNA methylation landscape, the first and best characterized epigenetic mark. In the context of human reproduction, epigenetics signals depict the mother-fetus crosstalk in which the maternal milieu dialogs with the growing embryo to establish an appropriate placental-fetal interface for a successful pregnancy. We here outline key features of the epigenetic crosstalk during the early embryo development and pregnancy establishment. The potential of inter- and trans-generational inheritance of specific epigenetic traits in response to environmental hints is also discussed. Finally, we move forward into future translational developments of epigenetics by discussing the potential use of epigenetic-based treatments (epidrugs) as upcoming therapeutic approaches in advanced personalized reproductive medicine.