TRPC6通过PARP-1/sirtuin-2调控necroptosis改善肾缺血再灌注损伤机制研究

Renal tubular epithelial cells injury in the pathophysiological process of renal ischemia reperfusion(RIR) production and development has been considered to occupy the central position.Recently,it is found that necroptosis by sirtuin-2 activity regulation of NAD+ dependent ,has played an important role in RIR renal ischemia reperfusion.Combined with the latest research progress, we find that transient receptor potential cation channel 6(TRPC6) can process through the inhibitition of renal tubular epithelial cell necroptosis alleviate RIR,and up-regulated expression of poly(ADP- ribose)polymerase-1 (PARP-1),which is also dependent on the NAD+.Based on these findings, we hypothesize that TRPC6 through PARP-1/NAD+ pathway regulate renal tubular epithelial cell necroptosis in RIR.We propose to demonstrate it and to elucidate its regulation mechanism through The construction of wild type/TRPC6 gene knockout animal renal ischemia reperfusion model and overexpression / low expression of TRPC6 renal tubular epithelial cells with hypoxiareoxygenation model and the histopathology, molecular biology methods. Thus, from the new angle of view, we explore the mechanism of RIR, which can provide a new option to prevent RIR.

肾小管上皮细胞损伤在肾缺血再灌注损伤的过程中居于中心地位，而细胞的转归取决于损伤/保护机制的相互作用。近来发现相当部分的肾缺血再灌注的细胞损伤属于程序性坏死（necroptosis），而necroptosis受到NAD+依赖的去乙酰化酶sirtuin-2调控。我们前期发现瞬时受体电位通道6(TRPC6）在肾缺血再灌注损伤中表达上调，激活TRPC6通道能抑制细胞的necroptosisi减轻缺血再灌注损伤，其机制可能是通过上调同样是NAD+依赖的PARP-1的表达。由于sirtuin-2和PARP-1互为竞争性抑制作用，并同样在细胞生存/死亡中发挥重要作用，基于此，我们提出TRPC6通过PARP-1/sirtuin-2调控缺血再灌注细胞necroptosis的假说，拟通过体内和体外实验，证明假说并阐明其调控机制，从新的视角探讨肾缺血再灌注损伤的发生机制，以便为临床提供新的防治靶点。

肾小管上皮细胞的损伤和修复在肾缺血再灌注损伤（RIRI）的过程中居于中心地位。近来发现相当部分的肾缺血再灌注的细胞损伤属于程序性坏死（necroptosis）。那么，如能调控necroptosis，我们就能有效地防治RIRI。我们前期通过动物模型差异基因及生物信息学分析，发现：瞬时受体电位通道6(TRPC6）在肾缺血再灌注损伤中表达上调。而TRPC6作为肾小管上皮细胞的感受器，同时分布于细胞的管腔侧和基地侧，很可能发挥了刺激感受和信息转导的关键枢纽作用。我们通过实验，首先证明了TRPC6激活/高表达有助于减轻necroptosis，其机制是通过上调PARP-1表达，竞争性抑制sirtuin-2的活性，从而调控necroptosis通路关键分子的活性，达到细胞保护的作用。随后，我们进一步证明了在缺氧时，TRPC6的激活和表达上调有赖于HIF-1α上调mir-26a后靶向调控TRPC6，并由此影响了肾小管上皮细胞的氧化应激、炎症反应和necroptosis的过程。通过以上探索，我们证明了TRPC6在RIRI时作为细胞感受器能感受缺氧刺激活化，并作为细胞内外信息传导的枢纽，通过下游信号传导通路调控necroptosis，可能成为调控RIRI细胞坏死的重要靶点。