人脐带间充质干细胞移植修复烧伤皮肤的机制

Mechanism of repairing burned skin with UC-MSCs in rats

目的探讨人脐带间充质干细胞(UC-MSCs)移植修复烧伤皮肤的机制。方法 24只SD大鼠均分为UC-MSCs移植治疗组和对照组。分别收集烧伤后12h、1、3、7d两组大鼠损伤局部的皮肤组织,抽提蛋白;ELISA法测定皮肤组织内细胞因子TNF-α、IL-1及IFN-γ的表达,Western blot法检测大鼠皮肤中MCP-1及CCX-2蛋白的变化,免疫组化法检测烧伤后14d两组碱性成纤维细胞生长因子(bFGF)及血管内皮生长因子(VEGF)表达量。结果烧伤后,大鼠烧伤皮肤细胞因子TNF-α和IL-1增加,IFN-γ表达下降;治疗组UC-MSCs移植后3d,TNF-α和IL-1下降,IFN-γ含量增加(P<0.05);烧伤7d时,受损皮肤中趋化因子MCP-1及CCX-2的表达增加,而UC-MSCs移植治疗组在烧伤7d时受损皮肤中MCP-1及CCX-2的表达量下降(P<0.05)。烧伤14d时,UC-MSCs移植治疗组的bFGF及VEGF表达量较对照组增加(P<0.05)。结论烧伤后,UC-MSCs移植治疗可能通过抑制皮损局部的炎症反应,减少淋巴细胞的浸润,促进血管的再生和成纤维细胞的生长来促进损伤皮肤的修复。

Objective To investigate the mechanism of burned skin repair with human umbilical cord mesenchymal stem cells（UC-MSCs）. Methods Twenty-four SD rats were equally assigned into two groups of A（treated with UC-MSCs） and B（controls）. The burned rat skin was collected and the protein was extracted for detecting the expressions of TNF-α, IL-1, IFN-γ by ELISA and chemotactic factors of MCP-1 and CCX-2 by Western blot analysis. And immunohistochemistry assay was performed for showing the proliferation of fiberoblasts and the expression of basic fihrohlast growth faetor（hFGF） and vascular endothelial growth factor（VEGF）. Results Compared to group B on the 3rd day, the expressions of TNF-α and IL-1 were decreased, but IFN-γ expression was increased in group A（P〈0. 05）. The MCP-1 and CCX-2 of burned skin were decreased, which were increased on the 7th day after burn with increased bFGF and VEGF in group A than that in group B on the 14th day （P〈0. 05）. Conclusion UC-MSCs can promote repairing of burned skin by suppressing the local inflammatory response and lymphocyte infiltration, promoting the regeneration of the blood vessels and the growth of fibroblasts.