TNFR2在促进老年小鼠足细胞损伤和肾脏衰老中的作用及机制

肾脏衰老是影响老年人健康的重要因素，足细胞损伤及减少是引起肾脏衰老及肾小球硬化的重要机制。我们前期研究发现：老年小鼠足细胞TNFR2的表达明显升高，TNFR2敲除对于老年小鼠出现的足细胞减少及蛋白尿具有保护作用，且该作用不依赖于TNFα。蛋白组学质谱分析和CoIP-MS分析发现细胞中TNFR2与乙酰胆碱受体CHRM5相互作用，已知乙酰胆碱受体活化可通过MLCK影响细胞骨架，进一步验证发现TNFR2表达升高引起的足细胞损伤可以被CHRM5抑制剂或MLCK敲除所阻断。因此提出假说：TNFR2通过CHRM5和MLCK促进老年小鼠足细胞损伤和肾脏衰老。本项目将应用微流控技术模拟足细胞体内微环境，结合基因敲除小鼠，研究TNFR2对足细胞的损伤机制，探讨TNFR2与CHRM5的相互作用和信号活化，证明TNFR2通过CHRM5及MLCK促进足细胞损伤和肾脏衰老。本课题将有助于探索干预肾脏衰老的新靶点。

Renal aging is an important factor affecting the health and longevity of the elderly. Podocyte injury and reduction is an important mechanism of kidney aging and glomerular sclerosis. Our previous research found that TNFR2 was significantly increased in the podocytes of elderly mice. TNFR2 knockout has a protective effect on the reduction of podocytes and albuminuria caused by renal aging independent of TNFα. Proteomics and CoIP-MS analysis revealed that TNFR2 interacts with the acetylcholine receptor CHRM5. It is reported that acetylcholine receptors can affect the cytoskeleton through MLCK. Further verification showed that podocyte injury caused by increased TNFR2 expression can be blocked by CHRM5 inhibitor or MLCK knockout. We speculate that TNFR2 contributes to podocyte injury and kidney aging through CHRM5 and MLCK. Our study will first clarify the effect of TNFR2 on podocyte injury and kidney aging through micro-fluidic chip, and then study the interaction between TNFR2 and CHRM5, and finally clarify the mechanism of TNFR2 contributes to podocyte injury and kidney aging through CHRM5 and MLCK. Our hypothesis is based on sufficient preliminary work. If the results support our hypothesis, it will serve as a pieces of evidence that will motive, and likely enable us to explore the novel target and novel therapeutic strategy for the prevention of kidney aging.