Epigenetics and cardiovascular regenerative medicine in the elderly.

Cardiovascular disease (CVD) is a recognized age-dependent condition whose incidence is set to increase due to the gradual aging of the population. Moreover, ischemic cardiovascular diseases (i.e. stroke, myocardial infarction, critical limb ischemia) requiring blood vessel growth are associated with a worse outcome in elderly patients. Therefore, understanding the molecular cues regulating the vascular repair process is of paramount importance to prevent undesirable cardiovascular complications in this setting. A growing body of evidence suggests that epigenetic modifications - changes to the genome that do not involve changes in DNA sequence - may significantly derail gene expression trajectories during the life course, thus affecting molecular phenotype and functionality of angiogenic cells, namely mature endothelial cells (ECs), endothelial progenitor cells (EPCs), and bone-marrow (BM)-derived angiogenic cells. In the present review, we discuss the emerging role of epigenetics in age-related impairment of the angiogenic process. Specifically, the following aspects are critically addressed: i) defective angiogenic process in aging; ii) impact of epigenetics (DNA methylation, histone modifications, microRNAs, long noncoding RNAs) on phenotype and function of ECs and BM-derived angiogenic cells; iii) clinical perspectives on epigenetic biomarkers and reprogramming approaches for autologous transplantation. A scrutiny characterization of the "old epigenome" may provide unprecedented insights to develop preventive strategies and regenerative therapeutic interventions in the elderly.