microRNA-126对内皮克隆形成细胞VEGF自分泌的调控作用及治疗糖尿病下肢血管病变的机制研究

Endothelial progenitor cells (EPCs) is a potential paracrine / autocrine system, is the focus of cell therapy. The newly discovered endothelial clony-forming cells is one of EPCs subtypes, which has stronger angiogenesis ability than the commonly used method of cultured EPCs. Our previous work showed that EPCs had strong VEGF autocrine function, acting on its membrane receptor KDR, forming a VEGF/KDR loop, promote angiogenesis in ischemic hindlimb. The biological function of EPCs declines in diabetic patients, mechanism is not clear, and autocrine research is rare. The new study found miR-126 through inhibition of Spred-1 enhances of the angiogenic effect of VEGF, and circulating miR-126 loss in diabetics, our previous study found that miR-126 is decreased in high glucose cultured endothelial colony-forming cells, indicates that the expression of miR-126 may be involved in the regulation of endothelial colony forming cell VEGF. Therefore need to be further confirmed miR-126 on endothelial colony-forming cells paracrine / autocrine effect of VEGF and its signal pathway mechanism, to elucidate the regulation mechanism of miR-126 in diabetic endothelial progenitor cells function decline and its role in the mechanism of diabetic lower extremity vascular disease treatment, provide a new targets for clinical cell therapy.

内皮祖细胞（EPCs）是机体潜在的旁分泌/自分泌系统，是细胞治疗的热点。新近发现的内皮克隆形成细胞(ECFC)为EPCs一种亚型，较目前常用方法培养的EPCs具有更强的成血管能力。我们前期工作表明EPCs有较强VEGF自分泌功能，作用于自身膜受体KDR，形成VEGF/KDR环路，促进缺血组织血管新生。糖尿病患者EPC生物学功能减退，机制不清，且自分泌研究较少。最新研究发现miR-126通过抑制Spred-1增强VEGF的前血管生成作用，而糖尿病患者循环miR-126下降，我们前期研究发现高糖培养ECFC后，其miR-126下降，提示miR-126可能参与调控ECFC的VEGF表达。因此需进一步证实miR-126对内皮克隆形成细胞VEGF自分泌及其信号通路的影响及机制，阐明miR-126在糖尿病内皮祖细胞功能减退的调控机制及其在糖尿病下肢血管病变的作用机制，为临床细胞治疗提供新依据及靶点。

背景：内皮克隆形成细胞及脐带间充质干细胞治疗对糖尿病下肢动脉病变、创面修复的效果尚未确定。.主要研究内容：1、研究探讨脐带血来源的内皮克隆形成细胞(ECFCs)、脐带间充质干细胞(UCMSCs)及两种细胞联合移植治疗糖尿病缺血性下肢血管病变模型小鼠的有效性及疗效比较。2、研究探讨ECFCs、UCMSCs、细胞培养基质及两种细胞联合治疗糖尿病小鼠皮肤创面的有效性，观察单种细胞、细胞自分泌因子、联合细胞治疗糖尿病创面修复的作用，并探讨相关的作用机制。.重要结果：1.1 UCMSCs和ECFCs移植能够有效改善糖尿病小鼠缺血下肢皮温及经皮氧分压。1.2UCMSCs和ECFCs移植可增加小鼠下肢腓肠肌血管密度。1.3 UCMSCs和ECFCs移植可增加小鼠下肢腓肠肌VEGF、Akt及Erk1/2蛋白表达。1.4 UCMSCs和ECFCs两种细胞联合移植具有协同作用，比单独移植一种细胞促血管新生作用更显著。2.1 ECFCs、UCMSCs及其自分泌因子移植能有效促进新生血管形成，加速组织修复。2.2 UCMSCs和ECFCs两种细胞联合移植具有协同作用，比单独移植一种细胞或自分泌因子促血管新生及组织修复作用更显著。2.3 ECFCs及其自分泌因子对糖尿病小鼠皮肤创面的修复作用可达到与UCMSCs及其自分泌因子相同的效果，为临床细胞移植治疗组织修复提供了新的思路。