Abstract:

Objective To explore the role of mouse dermis-derived mesenchymal stem cells （mdMSC） on skin repair. Methods mdMSC and human dermal fibroblasts were isolated and identified. Human dermal fibroblasts were cultured alone or cocultured with mdMSC in Transwell chambers with the density ratio of human dermal fibroblasts to mdMSC being 2/5, 1/1, and 2/1. On day 4 and 8 of culture, the expression levels of hydroxyproline and transforming growth factor-beta （TGF-beta） 1 were measured in the supernatant of monoculture and coculture by alkaline hydrolysis and ELISA respectively. Results The level of hydro- xyproline was significantly higher in the supernatants of coculture system with a density ratio of 2/5 and 1/1 than that in monoculture supernatants of human dermal fibroblasts on day 8 （both P < 0.05）. Elevated level of TGF-beta1 was observed in all coculture supernatants on day 8 （all P < 0.01） and in the supernatants of coculture system with a density ratio of 1/1 on day 4 （P < 0.05）. There was no significant correlation between the expression level of TGF-beta1 and hydroxyproline in the coculture supernatants （r = 0.108, P > 0.05）. Conclusion In vitro coculture with mdMSC can increase the production of hydroxyproline and TGF-beta1 by fibroblasts, which may be a mechanism underlying the facilitation of skin repair by mdMSC.