血管新生是缺血脑组织修复及功能重塑的关键环节，最新研究表明内皮细胞代谢是血管新生的驱动力。研究证实肢体远隔缺血适应（LRIC）促进缺血性脑卒中后血管新生，但其机制尚不清楚。预实验发现LRIC增加血浆外泌体中Notch1表达，且外泌体能被脑血管内皮细胞摄取；脑血管内皮细胞差异蛋白质组学分析发现，LRIC增加脂肪酸β-氧化（FAO）限速酶CPT1A表达，促进FAO。因此我们推测LRIC通过Notch1/CPT1A通路调节FAO，促进血管新生改善预后。本项目采用CPT1AΔEC基因敲除小鼠、基因过表达/敲低的细胞，结合放射性核素标记的代谢途径检测、染色质免疫沉淀、血管成像等方法，验证假说：LRIC介导的外泌体Notch1靶向脑血管内皮细胞中CPT1A，调控FAO，促进内皮细胞增殖迁移，进而促进脑缺血后血管新生改善预后。本项目将明确脑缺血康复治疗新的干预机制，为脑卒中后血管新生调控提供新靶点。

Angiogenesis is a key restorative mechanism in response to ischemia stroke. Recent studies have shown that endothelial cell metabolism is the driving force of angiogenesis. Studies have confirmed that limb distant ischemic conditioning (LRIC) promotes angiogenesis after ischemic stroke, but the underlying mechanism is still unclear. In our preliminary experiments, the data showed that LRIC increased the expression of Notch1 in plasma exosomes, which could be further absorbed by cerebrovascular endothelial cells. Differential proteomics analysis of cerebrovascular endothelial cells demonstrated that LRIC enhanced the expression of fatty acid β-oxidation (FAO) rate-limiting enzyme CPT1A and increased the FAO level. Therefore, we speculated that LRIC could regulate the FAO pathway through the Notch1/CPT1A signaling, enhance angiogenesis and improve prognosis. In this proposed project, we hypothesized that the LRIC could mediate the Notch1 in exosomes target to CPT1A in the cerebrovascular endothelial cells, leading to the regulation of FAO, then promote the migration and proliferation of endothelial cell, resulting in an enhanced angiogenesis after cerebral ischemia and eventually improve the prognosis. To testify the center hypothesis, several major techniques are applied, such as the establishment of CPT1AΔEC knockout mice, forming the overexpression/knock down genes cell lines, and the application of radioactive nuclide labeled metabolic pathway detection technology, chromatin immunoprecipitation, angiographic imaging etc. If successful, this project will not only provide a new intervention mechanism for cerebral ischemia rehabilitation treatment, but also launch a novel target for the regulation of angiogenesis after stroke.