Human adipose tissue-derived stem cells protect impaired cardiomyocytes from hypoxia/reoxygenation injury through hypoxia-induced paracrine mechanism.

Growing studies have emerged on adipose-derived stem cells (ADSCs), which hold the potential for cell-based therapy in diseased injured hearts. Apart from their differentiation pluripotency, such benefits also result from the ability of paracrine. The results of this study showed that after a 24-h hypoxia culture, ADSCs secreted amplified quantities of hepatocyte growth factor, interleukin-1, vascular endothelial growth factor-A, fibroblast growth factor-2, and transforming growth factor-β, all of which increased statistically compared with normoxia cultures. Resultantly, conditioned media (CM) from hypoxia-treated ADSCs can promptly improve cardiac function in in vivo infarction model as well as ameliorate apoptosis of cardiomyocytes subjected to hypoxia/reoxygenation conditions, accompanied by changes of JNK signal activation. While SP600125, a specific JNK pathway inhibitor, partly decreased cardiac cytoprotection assessed by incremental caspase-3 activation and subsequent TUNEL index, which led to no significantly different outcome between CM from ADSCs in normoxia culture and those in hypoxia culture. These data suggested that, in response to hypoxia, ADSCs could amplify expression of several protective soluble factors, which mediate direct cytoprotection. Furthermore, the improvement for impaired cardiomyocytes treated by hypoxia-induced ADSCs-CM was significant in part because of the involvement of the JNK signal pathway.