Stromal cell-derived factor-1 promotes human adipose tissue-derived stem cell survival and chronic wound healing

Adipose tissue-derived stem cells (ADSCs) hold great potential for the stem cell-based therapy of cutaneous wound healing. Stromal cell-derived factor-1 (SDF-1) activates CXC chemokine receptor (CXCR)4(+) and CXCR7(+) cells and plays an important role in wound healing. Increasing evidence suggests a critical role for SDF-1 in cell apoptosis and the survival of mesenchymal stem cells. However, the function of SDF-1 in the apoptosis and wound healing ability of ADSCs is not well understood. The aim of this study was to analyze the effect of SDF-1 on the apoptosis and therapeutic effect of ADSCs in cutaneous chronic wounds in vitro and in vivo. By flow cytometric analysis, it was found that hypoxia and serum free promoted the apoptosis of ADSCs. When pretreated with SDF-1, the apoptosis of ADSCs induced by hypoxia and serum depletion was partly recovered. Furthermore, in vivo experiments established that the post-implantation cell survival and chronic wound healing ability of ADSCs were increased following pretreatment with SDF-1 in a diabetic mouse model of chronic wound healing. To explore the potential mechanism underlying the effect of SDF-1 on ADSC apoptosis, western blot analysis was employed and the results indicate that SDF-1 may protect against cell apoptosis in hypoxic and serum-free conditions through activation of the caspase signaling pathway in ADSCs. This study provides evidence that SDF-1 pretreatment can increase the therapeutic effect of ADSCs in cutaneous chronic wounds in vitro and in vivo.