Abstract:

Objective We tried to investigate the effects of human umbilical cord mesenchymal stem cell exosomes （hUCMSC-Exos） on the proliferation of human dermal papilla cells （HDPCs） and the mechanism of hUCMSC-Exos promoting hair growth. Methods HDPCs were isolated using two-step enzymatic method and cultured in vitro. Human umbilical cord mesenchymal stem cells （hUC-MSCs） were cultured. Cell culture supernatant was collected， and exosomes were isolated and extracted using high-speed centrifugation. Electron microscopy， particle size， and surface marker identification were performed on them. Dihydrotestosterone （DHT） induces HDPCs and establishment of an androgenic alopecia cell model. Co-culture hUCMSC-Exos with HDPCs， cell proliferation experiment （EdU） was used to detect the relative activity of induced HDPCs. Real-time qPCR was used to detect the expression level of alkaline phosphatase （ALP）， and Western blot was used to detect β-catenin， Wnt10b， GSK-3β expression at the protein level. Results The obtained primary HDPCs， hUC-MSCs， and hUCMSC-Exos were all conformed to the characteristics of dermal papilla cells， mesenchymal stem cells， and exosomes. The number of EdU positive cells significantly increased， and exosomes could effectively promote the proliferation of HDPCs（P < 0.05）， enhance the vitality of HDPCs and alleviate the damage caused by DHT（P < 0.05）. Real-time qPCR showed that exosomes could enhance the expression level of ALP gene （P < 0.05） and hair follicle induction ability. Western Blot confirmation β-catenin， Wnt10b， GSK-3β were differences in expression at the protein level （P < 0.05）. Conclusions HUCMSC-Exos could promote DHT induced proliferation of HDPCs， enhance their hair follicle regeneration and repair ability， and its mechanism may be related to the activation of Wnt/ β-catenin signaling pathway.

Key words: dermal papilla cells, umbilical cord mesenchymal stem cells, exosomes, proliferation, regeneration