脐带间充质干细胞促进烫伤创面愈合的作用机制

Mechanism of cord mesenchymal stem cells in promoting wound healing of burn injury

目的探讨人脐带间充质干细胞(umbilical cord-derived mesenchymal stem cells,UCMSCs)多点局部注射后,修复烫伤皮肤创面的潜在机制。方法机械消化法分离人UCMSCs,培养至第3代后,进行形态观察、免疫表型和多向分化潜能鉴定。将第3代UCMSCs与碱性成纤维细胞因子(basic fibroblast growth factor,b FGF)共培养14 d,免疫荧光法检测成纤维细胞标志物波形蛋白的表达;对比小鼠Ⅲ度烫伤模型多点局部注射UCMSCs后创面愈合率及创面愈合时间;Dil标记UCMSCs,局部注射后检测UCMSCs在创面局部的分布情况。结果分离培养的UCMSCs的形态、表面抗原表达及体外诱导分化能力均符合间充质干细胞特性;经b FGF诱导后可显著提高UCMSCs中成纤维细胞标志物波形蛋白的表达量;局部注射UCMSCs可显著提高烫伤小鼠的创面愈合率,UCMSCs可定植于烫伤创面下。结论 UCMSCs具有较强的成纤维样细胞分化能力,经局部注射后,可通过定植于烫伤创面而显著提高创面愈合率。

Objective To inves tigate the potential mechanism of injection with umbilical cord mesenchymal stem cells（UCMSCs） in several sites in promoting the wound healing of burn injury. Methods UCMSCs were isolated by mechanical digestion method, subcultured to passage 3, observed for morphology, and identified for phenotype and potential in multipotential differentiation. The passage 3（P3） of UCMSCs were co-cultured with basic fibroblast growth factor（b FGF）for 14 d, and determined for expression of fibroblast biomarker vimentin by IFA, then locally injected into wound surface of burned mice, using PBS as control. The wound healing rate and time duration for healing of mice in two groups were compared. The UCMSCs were labeled with Dil and injected into the wound surface of burned mice, of which the distribution was observed. Results The morphology, expression of surface antigen and ability in induction of differentiation of the isolated UCMSCs were of the characteristics of mesenchymal stem cells. The induction with b FGF increased the expression level of vimentin in UCMSCs significantly. Local injection with UCMSCs increased the wound healing rate of mice with burn injury. The UCMSCs may be colonized under the wound surface. Conclusion UCMSCs showed high fibroblast-like differentiation potential, with which the local injection increased the wound healing rate of burn injury by colonization in the wound surface.