Telocytes in cardiac regeneration and repair

Telocytes (TCs) are a novel type of stromal cells reported by Popescu's group in 2010. The unique feature that distinguishes TCs from other "classical" stromal cells is their extremely long and thin telopodes (Tps). As evidenced by electron microscopy, TCs are widely distributed in almost all tissues and organs. TCs contribute to form a three-dimensional interstitial network and play as active regulators in intercellular communication via homocellular/heterocellular junctions or shed vesicles. Interestingly, increasing evidence suggests the potential role of TCs in regenerative medicine. Although the heart retains some limited endogenous regenerative capacity, cardiac regenerative and repair response is however insufficient to make up the loss of cardiomyocytes upon injury. Developing novel strategies to increase cardiomyocyte renewal and repair is of great importance for the treatment of cardiac diseases. In this review, we focus on the role of TCs in cardiac regeneration and repair. We particularly describe the intercellular communication between TCs and cardiomyocytes, stem/progenitor cells, endothelial cells, and fibroblasts. Also, we discuss the current knowledge about TCs in cardiac repair after myocardial injury, as well as their potential roles in cardiac development and aging. TC-based therapy or TC-derived exosome delivery might be used as novel therapeutic strategies to promote cardiac regeneration and repair.