Extracellular vesicles derived from adipose-derived stem cells accelerate diabetic wound healing by suppressing the expression of matrix metalloproteinase-9
Background: The healing of diabetic wounds is poor due to a collagen deposition disorder. Matrix metalloproteinase-9 (MMP-9) is closely related to collagen deposition in the process of tissue repair. Many studies have demonstrated that extracellular vesicles derived from adipose-derived stem cells (ADSC-EVs) promote diabetic wound healing by enhancing collagen deposition. Objective: In this study, we explored if ADSC-EVs could downregulate the expression of MMP-9 in diabetic wounds and promote wound healing by improving collagen deposition. The potential effects of ADSC-EVs on MMP-9 and diabetic wound healing were tested both in vitro and in vivo. Methods: We first evaluated the effect of ADSC-EVs on the proliferation and MMP-9 secretion of HaCaT cells treated with advanced glycation end product-bovine serum albumin (AGE-BSA), using CCK-8 western blot and MMP-9 enzyme-linked immunosorbent assay(ELISA). Next, the effect of ADSC-EVs on the healing, re-epithelialisation, collagen deposition, and MMP-9 concentration in diabetic wound fluids was evaluated in an immunodeficient mouse model via MMP-9 ELISA and haematoxylin and eosin, Masson’s trichrome, and immunofluorescence staining for MMP-9. Results: In vitro, ADSC-EVs promoted the proliferation and MMP-9 secretion of HaCaT cells.In vivo, ADSC-EVs accelerated diabetic wound healing by improving re-epithelialisation and collagen deposition and by inhibiting the expression of MMP-9. Conclusion: ADSC-EVs possessed the healing of diabetic wounds in a mouse model by inhibiting downregulating MMP-9 and improving collagen deposition.Thus ,ADSC-EVs are a promising candidate for the treatment of diabetic wounds .