Wound healing effect of adipose-derived stem cells: A critical role of secretory factors on human dermal fibroblasts

Background Adipose-derived stem cells (ADSCs) are a population of pluripotent cells, which have characteristics similar to bone marrow-derived mesenchymal stem cells. Whereas ADSCs have potential applications for the repair and regeneration of various damaged tissues, few studies have dealt with the effect of ADSCs on fibroblasts, which play a key role in skin biology. Objective In this study, we investigated the possible roles of ADSCs in skin wound healing process, especially in the aspect of fibroblast activation—proliferation, collagen synthesis and migratory properties. Methods and results ADSCs promoted human dermal fibroblast (HDF) proliferation, not only by cell-to-cell direct contact, which was confirmed by co-culture experiment, but also by paracrine activation through secretory factors, resolved by transwell co-culture and culturing with conditioned medium of ADSCs (ADSC-CM). ADSC-CM enhanced the secretion of type I collagen in HDFs by regulating the mRNA levels of extracellular matrix (ECM) proteins: up-regulation of collagen type I, III and fibronectin and down-regulation of MMP-1. Moreover, ADSC-CM showed stimulatory effect on migration of HDFs in in vitro wound healing models. Additional to those in vitro evidences, wound healing effect of ADSCs was also verified with in vivo animal study, resulted that ADSCs significantly reduced the wound size and accelerated the re-epithelialization from the edge. Conclusion Collectively, these data suggest that ADSC is constitutionally well suited for dermal wound healing and secretory factors derived from ADSCs promote wound healing via HDFs and ADSCs can be used for the treatment of photoaging and wound healing.