Non-invasive strategies for stimulating endogenous repair and regenerative mechanisms in the damaged heart.

The adult myocardium, including human, harbours a population of resident multi-potent cardiac stem cells (CSCs), which when stimulated under the right conditions can give rise to new cardiomyocytes and vasculature. Elucidation of the cellular and molecular mechanisms that govern CSC biology and their role in myocardial regeneration will allow the design and development of optimal therapeutic interventions. It is now evident that different growth factors and cytokines govern CSC survival, proliferation, migration and differentiation, as well as playing a role in activating cardiac repair mechanisms such as improving angiogenesis, cardiomyocyte survival and limiting fibrosis. This review article will summarize the evidence for a role of VEGF, NRG-1, IGF-1, HGF, EGF, FGF and TGF-β1 in modulating the repair and regeneration of cardiac tissue. It will also discuss the use of exosomes and exercise training as interventions to stimulate the endogenous repair and regenerative mechanisms in the damaged heart.