How Resident Stem Cells Communicate with Cardiac Cells in Beating Heart?

The adult myocardium is a dynamic tissue with different functions which normally adapts to endless mechanical loads throughout life. The complexity and diversity of myocardial responses to different conditions imply the coexistence of different cell types within a hierarchically ordered architecture. Rare stem/progenitor cells have been detected interspersed within the interstitium and/or adherent to the wall of the capillaries forming the myocardial microcirculation. The origin of these cells is still debated. Multipotent and self-renewing cells resident into the heart survive to a mechanically and biochemically active environment without acquiring a cardiac phenotype. The persistente of an intense physical and biochemical stress do not affect the gene profyle of these cells in beating heart. Otherwise, differentiated cardiac cells continually release humoral factors preserving the fate of stem/progenitor cells. It is conceivable that undifferentiated cardiac cells have a different bio-mechanical response threshold compared to cells resident in other tissue. The codification of the language adopted by cardiac stem/progenitor cells to communicate with each other and other myocardial cells will help cardiovascular therapy fulfill its true potential