question: what is the role of IGF-1 in cardiac regeneration after myocardial infarction?
answer: Ischemia-reperfusion injury is a strong stimulus for both global and focal cardiomyocyte progenitor cell marker up-regulations, correlating to the endogenous up-regulation of IGF-1. Furthermore, in an animal model of myocardial infarction, intracoronary administration of IGF-1 is shown to reduce pathological cardiac remodeling, induce myocardial regeneration, and improve ventricular function. IGF-1 is a potent modulator of stem cell replication, commitment to the myocyte lineage, and myocyte differentiation. In another study, the dual delivery of IGF-1 and HGF from affinity-binding alginate biomaterial prevented cell apoptosis, induced cardiomyocyte cell cycle re-entry and increased the incidence of GATA-4-positive cell clusters. The addition of nanofiber-mediated IGF-1 delivery to Cardiac Progenitor Cells therapy improved in part the recovery of myocardial structure and function after infarction. IGF-1 promotes proliferation and survival of CPCs. The strategy of IGF-1 transgene expression has shown to induce massive stem cell mobilization via SDF-1alpha signaling and culminated in extensive angiomyogenesis in the infarcted heart.