Fig. 1

Interactions among cardiac cells. Most types of cardiac cells, including CMs, cardiac fibroblasts, macrophages, and endothelial cells, regulate cardiac fibrosis and regeneration in a coordinated manner. Some paracrine factors from fibroblasts, including TGF-β and IGF-1, are known to promote the hypertrophic responses of CMs. The regulation of hypoxic environment and macrophage polarization is a key factor for enhancing crucial angiogenic responses involved in cardiac repair and regeneration