异体骨髓间充质干细胞治疗大鼠糖尿病足溃疡及血管内皮生长因子的表达

Allogeneic bone marrow mesenchymal stem cells for the treatment of diabetic foot ulcers in rats and vascular endothelial growth factor expression

背景:目前在临床多采用自体骨髓干细胞及自体外周血干细胞治疗糖尿病足溃疡,少见利用骨髓间充质干细胞治疗糖尿病足溃疡的基础研究。目的:观察局部移植异体骨髓间充质干细胞治疗大鼠糖尿病足溃疡的效果及血管内皮生长因子的全身及局部表达情况。方法:取雄性Wistar大鼠90只,随机数字表法分为3组:对照组(正常足部溃疡)、干细胞治疗组、糖尿病对照组。干细胞治疗组、糖尿病对照组建立2型糖尿病足溃疡模型,造模后分别注射同种异体骨髓间充质干细胞、干细胞培养基DMEM。造模后第1,4,8天观察各组大鼠溃疡面积、细胞核染色示踪及病理学检查,ELISA法测外周血血管内皮生长因子浓度、Western-blotting法测局部血管内皮生长因子浓度。结果与结论:与糖尿病对照组比较,干细胞治疗组溃疡愈合速度迅速,但仍较对照组愈合缓慢,外周血中血管内皮生长因子表达增高,也未达到正常水平。异体干骨髓间充质干细胞治疗前期(1～4d)能明显提高局部血管内皮生长因子浓度,但在后期(8d)局部浓度提高不足。干细胞治疗组愈合缓慢,表皮覆盖不完全,但较糖尿病对照组愈合明显提前,表皮覆盖较明显;细胞核染色示移植后干细胞均聚集于溃疡区周围。提示异体移植骨髓间充质干细胞可促进大鼠糖尿病足溃疡的愈合,其促进愈合的可能机制为其上调了血管内皮生长因子在全身尤其局部的表达。

BACKGROUND：Autologous bone marrow stem cells and autologous peripheral blood stem cells are commonly used to treat diabetic foot ulcer in clinic.Few studies have addressed basic research of bone marrow mesenchymal stem cells （BMSCs） for diabetic foot ulcer.OBJECTIVE：To investigate the effect of local transplantation of allogeneic BMSCs in the treatment of rats with diabetic foot ulcers and the systemic and local expression of vascular endothelial growth factor （VEGF）.METHODS：A total of 90 male Wistar rats were randomly divided into three groups：control group （normal foot ulcers）, BMSCs treatment group and diabetic control group.Rat models of type 2 diabetic foot ulcers were established in the BMSCs treatment group and diabetic control group.Following model induction, allogenic BMSCs and stem cell medium DMEM were respectively injected.At 1, 4 and 8 days following model establishment, rat ulcer area was observed in each group.Nucleus staining tracing and pathological examination were conducted.Enzyme linked immunosorbent assay was utilized to measure VEGF concentration in peripheral blood.Western blot assay was employed to detect VEGF concentration in local region.RESULTS AND CONCLUSION：Compared with diabetic control group, ulcer healed faster in the BMSCs treatment group, but slower than control group.Peripheral blood VEGF expression increased, but did not reach normal levels.In early days of allogenic BMSCs treatment （1-4 days）, VEGF concentration was significantly elevated, but slightly elevated in late days （8 days）.In the BMSCs treatment group, healing was slow; epidermis was not completely covered.The healing was significantly early compared with diabetic control group, and epidermis was obviously covered.Nucleus staining demonstrated that transplanted stem cells gathered in the regions surrounding ulcers.These indicated that allogenic BMSCs can promote the healing of diabetic foot ulcers in rats.The mechanism may be that it increased the VEGF expression in systemic condition, especially local condition.