IR及ERK1/2MAPK-GSK-3β信号参与慢性移植肾IF/TA早期发病机制的实验研究

Our previous studies suggest that insulin resistance (IR) is associated with chronic renal allograft dysfunction (CRAD), but there is no study revealing the mechanism of IR to induce CRAD. It has been found in our previous studies in kidney transplantation without IR that the up-regulation of MMP-9, RANTES, MCP-1, ICAM-1 expression plays a role in the pathogenesis of the infiltration of inflammation cells and migration of vascular smooth muscle cells (VSMCs) at the early stage of CRAD, and that human renal tubular cell EMT can be induced by ERK1/2MAPK-GSK-3β - β-catenin signaling pathway. Based on CRAD+IR rat model and the interference of Rosiglitazone as an insulin sensitizer, our present project is planed to prove, as an in vivo study for the first time, that IR promote the infiltration of inflammation cells and migration of VSMCs and EMT of tubular cells at the early stage after renal transplantation and therefore promote chronic renal allograft IF/TA. Meanwhile, with the interfering experiment with TDZD-8, an inhibitor of GSK-3β, prove that the effect of IR to result in renal tubular EMT is induced by GSK-3β - β-catenin signaling pathway at the early stage of renal allograft IF/TA, and that the effect of IR to promote the expression of MMP-9 and above inflammatory factors is induced by GSK-3β -NF-κB signaling pathway and therefore promote the infiltration of inflammatory cells and migration of VSMCs at the early stage of renal allograft IF/TA.

我们前期研究结果提示胰岛素抵抗（IR）与慢性移植肾失功（CRAD）有明显关联，但国内外尚缺乏对IR导致CRAD机制的研究。我们前期在非IR肾移植研究发现MMP-9、RANTES、MCP-1、ICAM-1基因表达上调参与CRAD早期炎症细胞浸润和VSMCs移行机制，ERK1/2MAPK-GSK-3β-β-catenin信号通路介导人肾小管上皮EMT。本项目采用CRAD+IR大鼠模型，应用胰岛素增敏剂罗格列酮作为IR干预手段，在国内外率先在CRAD体内实验证实IR促进移植肾早期炎症细胞浸润、VSMCs移行和小管上皮EMT，促进慢性移植肾IF/TA。同时用GSK-3β抑制剂TDZD-8进行干预，证实GSK-3β-β-catenin信号通路介导IR促进移植肾早期EMT；证实GSK-3β-NF-κB信号通路介导IR促进移植肾早期MMP-9和上述炎症因子表达，进而促进炎症细胞浸润和VSMCs移行。

本项目采用CRAD+IR大鼠模型，应用胰岛素增敏剂罗格列酮作为干预手段，同时应用GSK3β抑制剂TDZD8进行干预,在国内外率先在CRAD体内实验证实胰岛素抵抗促进移植肾早起炎症细胞浸润、VSMCs移行和小管上皮EMT，促进慢性移植肾IF/TA。在本计划的资助下，我们发现，GSK-3β-β-catenin信号通路的活化介导了IR促进移植肾早期EMT；证实GSK-3β-NF-κB信号通路的活化介导了IR促进移植肾早期MMP-9和炎症因子表达，进而促进炎症细胞浸润和VSMCs移行。本研究在国际上首次探讨了IR导致慢性移植肾失功的具体机制及其信号通路，为未来临床应用胰岛素增敏剂罗格列酮防治IR/MS导致慢性移植肾失功提供实验基础，有助于提高移植肾长期存活率。在执行本研究计划中我们共发表标注本基金的SCI论文4篇，核心期刊2篇。