RESUMO
BACKGROUND: Adipose-derived stem cells (ADSCs) represent one of the promising cell sources for myocardial regeneration due to their easy accessibility and efficacy in the improvement of cardiac function following myocardial infarction. However, previously reported studies on the underlying mechanism of ADSCs-mediated cardioprotective effect mainly focused on the ADSCs cultured at room air. OBJECTIVE: To test the paracrine actions and anti-apoptotic effect of ADSCs under hypoxic conditions. METHODS: After isolation and culture, neonatal rat myocardial cells were injured by hydrogen peroxide and co-cultured with rat ADSCs under normoxia and hypoxia (10% O2) conditions. Ratio of reduced glutathione to oxidized glutathione (GSH/GSSG) in the cell pellet and levels of vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1), and basic fibroblast growth factor (bFGF) were tested by ELISA. Expression of apoptotic proteins Bax and Bcl-2 were determined by western blot. RESULTS AND CONCLUSION: GSH/GSSG, VEGF, IGF-1, and bFGF were decreased in neonatal rat myocardial cells injured by hydrogen peroxide. ADSCs significantly attenuated hydrogen peroxide-induced myocardial apoptosis by increasing the ratio of GSH/GSSG and the secretion of VEGF, IGF-1 and bFGF. ADSCs also down-regulated Bax expression and up-regulated Bcl-2 expression. To conclude, hypoxic conditions can enhance the anti-apoptosis and cardioprotective effects of ADSCs through the paracrine mechanism.