骨髓间充质干细胞miR-126高表达在游离皮瓣移植后皮瓣血管新生中的促进作用及机制研究

Promoting effect and mechanism of miR-126 overexpression in bone marrow mesenchymal stem cells on angiogenesis after skin flap transplantation

目的:研究骨髓间充质干细胞(BMSCs)microRNA-126(miR-126)高表达在游离皮瓣移植后皮瓣新生血管中的促进作用及机制。方法:将24只SD大鼠随机分为观察组分别在游离皮瓣远端1 cm与3 cm处注射2 ml含有1×106miR-126 mimics转染的BMSCs,阴性对照组为注射miR-126 mimics control转染的BMSCs,空白对照组注入等量的磷酸盐缓冲液,三组各8只。通过瞬时转染的方法增强BMSCs中miR-126的表达水平,对三组皮瓣组织液中的TNF-α、MIP-1α和VCAM-1蛋白水平进行测定,并检测三组BMSCs中TNF-α、MIP-1α和VCAM-1 mRNA的表达水平。结果:观察组皮瓣组织液中TNF-α、MIP-1α和VCAM-1蛋白表达水平较空白对照组、阴性对照组均显著降低(均P<0.01),而阴性对照组TNF-α、MIP-1α和VCAM-1蛋白表达水平较空白对照组均显著降低(均P<0.01)。观察组转染后BMSCs中TNF-α、MIP-1α和VCAM-1mRNA相对表达量较空白对照组、阴性对照组均显著降低(均P<0.01),而阴性对照组TNF-α、MIP-1α和VCAM-1 mRNA相对表达量较平较空白对照组均显著降低(均P<0.01)。结论:在游离皮瓣移植后,miR-126高表达可降低TNF-α、MIP-1α和VCAM-1 mRNA表达水平,使之发挥阻滞血管炎症反应的作用,诱导游离皮瓣组织中血管新生腺管蛋白活化,最终有助于皮瓣新生血管的生成,促进皮瓣成活。

Objective：To study the promoting effect and mechanism of microRNA-126（miR-126）overexpression in bone mesenchymal stem cells（BMSCs）on angiogenesis after skin flap transplantation.Methods：24 SD rats were randomly divided into the observation group respectively in the free skin flap of 1 cm and 3 cm injected with 2 ml containing 1 × 10^6 miR-126 mimics transfected BMSCs,negative control group was transfected by injection of miR-126 mimics control of BMSCs and the blank control group was injected with phosphate buffer,with 8 rats in each group.The transient transfection was used to enhance the expression level of miR-126 in BMSCs.The protein levels of TNF-α,MIP-1α and VCAM-1 in the flap tissue were determined of the two groups,and the expression levels of TNF-α,MIP-1α and VCAM-1 mRNA in BMSCs were detected in the two groups.Results：The expression levels of TNF-α,MIP-1α and VCAM-1 in the tissue fluid of the observation group were significantly lower than those in the blank control group and the negative control group（all P 〈 0.01）,while the expression levels of TNF-α,MIP-1α and VCAM-1 in the negative control group were significantly lower than those in the blank control group（all P 〈 0.01）.The observation group after transfection in BMSCs,TNF-α MIP-1α and VCAM-1 mRNA relative expression were significantly lower than those in the blank control group and the negative control group（all P 〈 0.01）,and the TNF-α MIP-1α and VCAM-1 mRNA relative expression in the negative control group were significantly lower than those in the blank control group（all P 〈 0.01）.Conclusion：After the transplantation of free flap,high expression of miR-126 reduces the expression of TNF-α,MIP-1α and VCAM-1 mRNA,which can play the role of blocking vascular inflammation,activating angiogenesis induced by free flap glandular tissue,ultimately contribute to the neovascularization of flaps,and the survival of skin flaps.