The cardioprotective effect of mesenchymal stem cells is mediated by IGF-I and VEGF.

Emerging evidence suggests that adipose tissue-derived stem cells (ASCs) can be used for the treatment of ischemic heart diseases. However, the mechanisms underlying their therapeutic effects have not been clearly defined. In this study cytokines released by ASCs were detected by ELISA and pro-angiogenic effects were assessed by tube formation assay. To define the anti-apoptotic effect of ASCs, neonatal rat cardiomyocytes were subjected to hypoxia condition in a co-culture system. Our data show that ASCs secrete significant amounts of VEGF (810.65+/-56.92 pg/microg DNA) and IGF-I (328.33+/-22.7 pg/microg DNA). Cardiomyocytes apoptosis was significantly prevented by ASCs and 62.5% of the anti-apoptotic effect was mediated by IGF-I and 34.2% by VEGF. ASCs promoted endothelial cell tube formation by secreting VEGF. In conclusion we demonstrated that ASCs have a marked impact on anti-apoptosis and angiogenesis and helps to explain data of stem cells benefit without transdifferentiation.