糖化apoL1通过诱导肾小球足细胞胰岛素抵抗促进糖尿病肾病发生的研究

Glycated apoL1 was strongly associated with diabetic kidney diseases. Unfortunately, we still do not have a clear understanding of the adverse effect played by g-apoL1 in podocytes, nor how the abnormal modifaction initiates the development of diabetic nephropathy. In the present study, we have demonstrated that g-apoL1 might induce podocyte insulin resistance in both in vivo and in vitro models, leading to morbific podocyte structure, inhibited autophagy and impaired renal function. Furthermore, we confer that the innate immunity receptor RIG-I and its co-adaptor MAVS might play a pivotal role in this Patho-physiological process. Future in vivo and in vitro experiments will illustrate the mechanism underlying podocytes insulin resistance and dysfunction induced by g-apoL1 by use of RNA interfere, specific inhibitors and RIG-I knockout mice through RIG-I/MAVS—TRAF6—JNK pathway. The purpose of this study is to further exploit the molecular mechanisms of diabetic nephropathy and to provide a new strategy to treat diabetic nephropathy.

ApoL1糖化程度与糖尿病患者肾脏病变严重程度相关，可能是糖尿病肾病发生发展的重要原因，其作用机制不明。我们前期首次证实糖化apoL1可诱导胰岛素抵抗，导致糖尿病样肾脏损害，并发现固有免疫受体RIG-I在此过程中扮演重要角色。在此基础上我们推测糖化apoL1可能通过RIG-I/MAVS—TRAF6—JNK通路诱导足细胞胰岛素抵抗。基于该假说，本项目拟利用原代培养的足细胞模型，通过RNA干扰、腺病毒过表达及药物干预等方法特异性激活或抑制RIG-I/MAVS—TRAF6—JNK通路，研究该通路如何影响糖化apoL1所致胰岛素抵抗；并利用现有的RIG-I敲除小鼠，腹腔注射糖化apoL1，建立足细胞胰岛素抵抗及糖尿病肾病模型，阐明RIG-I/MAVS—TRAF6—JNK通路对糖化apoL1所致损伤的介导作用，以揭示糖化apoL1在糖尿病肾病发生发展中的作用及机制，为疾病防治提供理论指导和实验依据。

载脂蛋白L1（APOL1）基因的遗传变异与非糖尿病性肾脏疾病有关。但是，关于ApoL1在肾小球损伤中的作用了解甚少。我们建立腹腔注射ApoL1（10μg/只，隔天一次）的 C57小鼠模型及建立不同浓度ApoL1（0~20μg/ml）孵育的人足细胞模型，在动物及细胞层面上ApoL1均增加黏附因子、炎症因子和趋化因子的表达，同时肾小球足细胞炎症细胞浸润、足细胞凋亡均增加；进一步研究发现ApoL1经由RIG-I--P65通路，诱导足细胞炎症和凋亡的机制。利用病毒、si-RNA分别在动物和细胞模型上敲低RIG-I，ApoL1诱导的肾小球损伤在AAV-shRIG-I小鼠中减弱，同时RIG-I的敲低显著减轻了ApoL1诱导的人足细胞炎症和凋亡标记物的上调。总之，我们阐明了分泌型ApoL1经由RIG-I--P65通路，诱导人足细胞炎症和凋亡的机制，为疾病防治提供新的靶点和策略。