小鼠真皮间充质干细胞与成纤维细胞共培养对胶原分泌和TGF-β1表达的影响

目的 探讨真皮间充质干细胞在皮肤组织修复中的作用.方法 采用低血清培养基,消化-贴壁-传代法体外培养、鉴定小鼠真皮间充质干细胞(mdMSC),并与体外分离培养的正常人皮肤成纤维细胞于transwell小室培养体系中共培养,样本碱水解法和ELISA法分别检测第4、8天培养上清液中羟脯氨酸和TGF-β1的变化.结果 共培养第8天,经mdMSC 2.5×104和mdMSC 1×104处理的正常人皮肤成纤维细胞培养上清液中羟脯氨酸含量较单独培养时明显增高(P<0.05).经mdMSC处理的各组正常人皮肤成纤维细胞培养上清液中TGF-β1含量于共培养第8天时均高于单独培养(P<0.01);经mdMSC 1×104处理的正常人皮肤成纤维细胞培养上清液中TGF-β1含量在第4天亦高于单独培养,差异有统计学意义(P<0.05).各不同细胞密度的MSC处理组的羟脯氨酸含量与TGF-β1水平无相关关系(r=0.108,P＞0.05).结论 mdMSC与正常人皮肤成纤维细胞共培养可增加羟脯氨酸和TGF-β1的分泌,可能是mdMSC促进皮肤组织修复的机制之一.

Effect of eoeulture with mouse dermis-derived mesenehymal stem cells on the secretion of collagen and expression of transforming growth faetor-betal by hnman dermal fibroblasts

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 eoeultured 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 supematant of monoculture and coculture by alkaline hydrolysis and ELISA respectively. Results The level of hydro-xyproline was significantly higher in the supematants of coculture system with a density ratio of 2/5 and 1/1 than that in monoculture supematants of human dermal fibroblasts on day 8 (both P < 0.05). Elevated level of TGF-betal was observed in all coculture supematants 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-betal 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-betal by fibroblasts, which may be a mechanism underlying the facilitation of skin repair by mdMSC.