自体CD34+细胞移植可用于治疗手术难以重建血运的重度肢体缺血（CLI），但疗效受患者年龄、细胞采集量等制约。低氧预处理CD34+细胞（HPCD34C）促血管新生明显增强，有望突破上述瓶颈，其机制有待探明。申请人前期研究发现HPCD34C外泌体miR-378-5p表达显著升高，基于生物信息分析提出机制假说—HPCD34C通过外泌体miR-378a-5p调控成纤维细胞SuFu/Hedgehog通路促进血管新生。拟从体内/外实验证明该机制:①验证HPCD34C外泌体向成纤维细胞转运miR-378a-5p；②miR模拟物/抑制物转染HPCD34C，验证外泌体miR-378a-5p介导血管新生；③验证外泌体miR-378a-5p抑制靶点SuFu，增强Hedgehog通路关键因子Gli和下游血管新生因子表达。如获成功，预期将为HPCD34C修复CLI向临床治疗转化提供关键的基础理论依据。

Auto-CD34+ cell transplantation can be applied to treat no option critical limb ischemia(CLI), but the efficacy is limited by patient age and cell number. Hypoxic preconditioned CD34+ cell (HPCD34C) can enhance neovascularization significantly and may breakthrough the limitation. The machanism needs to be clarified. Our previous study found HPCD34C exosome is enriched with miR-378a-5p and could improve angiogenesis significantly. Based on the bioinformatics analysis and literature, we proposed a hypothesis that HPCD34C exosomal miR-378a-5p regulates the fibroblast SuFu/Hedgehog signaling way to improve angiogenesis. To prove the hypothesis, the project intended to execute the following steps by in vivo and in vitro experiments. First, we should prove the HPCD34C exosome could deliver miR-378a-5p into fibroblast. Second, we should prove HPCD34C exosomal miR-378a-5p mediates angiogenesis using miR-mimic and anti-miR. Third, we should prove HPCD34C exosomal miR-378a-5p could inhibit SuFu to up-regulate Gli expression in the Hedgehog signaling pathway and downstream pro-angiogenic factors expression. The completion of this project would provide critical theoretical basis for the novel HPCD34C treatment for CLI.