Netrin-1调控巨噬细胞活化对失神经后血管新生的影响及分子机制

糖尿病周围神经血管病变（DPNV）发病率高、病程长、防治困难，巨噬细胞（Mφ）在促进失神经后血管新生中起重要作用，但具体机制不明。研究发现，TGF-β1可介导Mφ迁移及活化，我们的预实验发现失神经后神经导向因子Netrin-1及Mφ表面受体UNC5B的表达上调，且高表达TGF-β1的Mφ在损伤组织处大量募集及浸润。由此我们假设: Netrin-1与UNC5B结合活化Mφ，通过分泌TGFβ1激活内皮细胞ALK1/Smad1/5信号通路，促进失神经后血管新生。本项目拟体外检测低氧及高糖环境下Netrin-1对Mφ迁移及活化的影响；体内移植治疗糖尿病失神经损伤小鼠，检测新生血管血流、密度变化；应用Netrin-1受体阻断剂及siRNA技术探讨TGFβ1/ALK1/Smad1/5信号通路的变化，阐明Netrin-1调控Mφ活化促进失神经后血管新生的分子机制，为DPNV的防治提供新思路。

Diabetic peripheral nerve and vascular disease (DPNV) has high incidence, long course, and the early prevention and treatment are difficult. Macrophages (Mφ) play a pivotal role in promoting diabetic peripheral nerve and angiogenesis, however, the underlying mechanism has not been fully elaborated. TGF-β1 signaling has been reported to mediate the migration and activation of Mφ, our previous results showed that and the expression of nerve guiding factors (Netrin-1) and Mφ surface receptor UNC5B were up-regulated, and Mφ with high expression of TGF-β1 was homed and infiltrated in large quantities around the injured blood vessels. Based on these, we hypothesize that Netrin-1 combining with the surface receptor UNC5B to activate Mφ through TGFβ1/ALK1/Smad1/5 signal transduction and further promote angiogenesis ability in diabetic mice after denervation. This study will base on our previous results, to explore the influence of Netrin-1 on Mφ survival, migration, and the differentiation capacity under low oxygen and high sugar microenvironment. Netrin-1-Mφ cells were transplanted into a unique diabetic mouse model of denervation. The numbers, diameters, and density of new vessels will also be analyzed at different transplantation times. Netrin-1 receptor UNC5B blocking agents and RNA Interference Silencing will be used to explore the possible effects of Netrin-1 transfected Mφ in promoting angiogenesis in diabetic mouse model of denervation. The associated signal pathway TGFβ1/ALK1/Smad1/5 will be discussed and the molecular mechanisms will be elucidated, which will bring new insights and theoretical basis into the prevention and treatment of diabetic peripheral nerve and vascular disease.