Epigenetics: new concepts of old phenomena in vascular physiology.

The hypothesis of 'Developmental Origins of Health and Disease' (DOHaD) relies on the presence of mechanisms sensing and signalling a diversity of stimuli during fetal development. The mechanisms that have been broadly suggested to be involved in these processes are the epigenetic modifications that could 'record' perinatal stimuli. Since the definition of epigenetic and the associated mechanisms are conflictive, in this review epigenetic was defined as 'chromosome-based mechanisms that can change the phenotypic plasticity in a cell or organism'. The most understood epigenetic mechanisms (i.e. DNA methylation, histone post-translational modifications (PTM), ATP-dependent chromatin modifications and non-coding RNAs) and reported evidence for their role in fetal programming were briefly reviewed. The development of the vascular system is strongly influenced by epigenetic mechanisms. For that reason vascular cells are good candidates to be explored regarding epigenetic programming since its proved susceptibility to be imprinted. This has been described in pregnancy diseases such as intra-uterine growth restriction, gestational diabetes and pre-eclampsia, where changes in vascular function are preserved in vitro.