诱导性多能干细胞(iPS细胞)在血管再生方面最具有应用前景。20012年《Nature》杂志对此有专题报道，但iPS细胞移植促缺血组织血管新生的机制不清。申请人前期发现，将抑制活性氧(ROS)的iPS细胞移植入小鼠体内，小鼠缺血下肢血管新生比iPS移植组明显降低；抑制iPS细胞ROS产生抑制VEGF表达，及细胞的粘附，迁移和增殖。NADPH氧化酶是iPS细胞最主要ROS来源，其亚基Nox4和Nox2在iPS细胞中高表达。本项目拟通过抑制iPS细胞NADPH氧化酶活性或者Nox4或Nox2表达，研究：1）NADPH氧化酶来源的ROS对iPS细胞移植促小鼠缺血下肢血管新生的影响，及对体内iPS细胞旁分泌和分化的影响。2）明确其是否通过调控VEGF表达影响iPS细胞迁移和增殖。3）研究其对iPS细胞粘附和分化成血管内皮细胞的影响及分子机理。这项研究将为iPS细胞移植治疗缺血性疾病提供科学依据。

Induced pluripotent stem cells (iPSCs) are a promising cell type for cell-based vascular regeneration. There is a special subject about iPSCs' research applications in 2012 published by Nature. IPSC transplantation promotes angiogenesis of ischemic tissue. However, the molecular mechanisms of iPSC transplantation linked to angiogenesis remains unknown. We found that transplanted antioxidant NAC-treated iPSCs impaired neovascularization compared with iPSC transplation in hindlimb ischemic mice. NAC treatment inhibited VEGF expression, and impaired cell adhesion and inhibited migration and proliferation of iPSCs in vitro. NADPH oxidase is major sources of reactive oxygen species (ROS) in iPSCs, we showed that NADPH oxidase subunit Nox4 and Nox2 are highly expressed in iPSCs. By scavenging of ROS with inhibition of NADPH oxidase activity, or Nox4 or Nox2 expression in iPSCs, we attempt to investigate the role of NADPH oxidase-derived ROS on the efficacy of iPSCs for angiogenesis, and their role on the paracrine effect and differentiation of iPSCs in a mouse hindlimb ischemia model. We will determine whether NADPH oxidase-derived ROS are involved in iPSC migration and proliferation by regulating the VEGF expression, and investigate the role and underling mechanisms of NADPH oxidase-derived ROS in iPSC adhesion and differentiation into vascular endothelial cells. This study will provide the scientific basis for the treatment of ischemic diseases by iPSC transplantation.