Cardiovascular Stem Cell Niche

Abstract In the myocardium, cardiac progenitor cells (CPCs) are clustered in interstitial microdomains with the architectural organization of stem cell niches. The structural and molecular properties of the niche condition the response of the tissue to physiological and pathological cues by favoring the interaction of stem cells with the surrounding cells and the interstitial space. Stem cell niches have a critical role in cardiac homeostasis and myocardial repair after injury. However, cardiomyogenesis may also depend on the replication of a self-sustained pool of preexisting immature myocytes. These mechanisms of tissue restoration may act in concert to regenerate organs like the heart with a complex structural and functional identity. In this chapter, we will emphasize the relevance of CPCs and their niches to cardiomyogenesis. Alternative stem cell–independent mechanisms that may account for the global replenishment of the lost cardiomyocytes will also be discussed.