Mesenchymal Stem Cell-Derived Exosomes Promote Scalp Rejuvenation Through Type XVII Collagen Regulation Via the miR-21-5p/DKK2/Wnt Pathway

The study investigates the effects of mesenchymal stem cell-derived exosomes on hair follicle aging and regeneration. Exosomes from human umbilical cord MSCs were tested on senescent human dermal papilla cells, human hair follicle organ culture, and a mouse model. Results showed that exosome treatment significantly reduced senescent cells, increased COL17A1 mRNA and protein levels, enhanced hair follicle elongation, and improved hair coverage in mice compared to controls and minoxidil. The mechanism involves miR-21-5p targeting DKK2, leading to Wnt/β-catenin pathway activation and COL17A1 upregulation. This suggests that hUC-MSC-derived exosomes could be a promising strategy for scalp rejuvenation.