WTAP-mediated m⁶A modification of TRIM22 promotes diabetic nephropathy by inducing mitochondrial dysfunction via ubiquitination of OPA1

Diabetic nephropathy (DN) is one of the most serious microvascular complications of diabetes and is the most common cause of end-stage renal disease. Tripartite motif-containing (TRIM) proteins are a large family of E3 ubiquitin ligases that contribute to protein quality control by regulating the ubiquitin – proteasome system. However, the detailed mechanisms through which various TRIM proteins regulate downstream events have not yet been fully elucidated. The current research aimed to determine the function and mechanism of TRIM22 in DN. DN models were established by inducing HK-2 cells using high glucose (HG) and diabetic mice (db/db mice). Cell viability, apoptosis, mitochondrial reactive oxygen species, and mitochondrial membrane potential were detected by Cell Counting Kit-8 and flow cytometry, respectively. Pathological changes were evaluated using hematoxylin and eosin, periodic acid schiff and Masson staining. The binding between TRIM22 and optic atrophy 1 (OPA1) was analyzed using co-immunoprecipitation. The m⁶A level of TRIM22 5′UTR was detected using RNA immunoprecipitation. TRIM22 was highly expressed in patients with DN. TRIM22 silencing inhibited HG-induced apoptosis and mitochondrial dysfunction in HK-2 cells. Promoting mitochondrial fusion alleviated TRIM22 overexpression-induced cell apoptosis, mitochondrial dysfunction in HK-2 cells, and kidney damage in mice. Mechanistically, TRIM22 interacted with OPA1 and induced its ubiquitination. Wilms tumor 1-associating protein (WTAP) promoted m⁶A modification of TRIM22 through the m⁶A reader insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1). TRIM22 silencing inhibited the progression of DN by interacting with OPA1 and inducing its ubiquitination. Furthermore, WTAP promoted m⁶A modification of TRIM22 via IGF2BP1.

糖尿病肾病（Diabetic nephropathy, DN）是糖尿病最严重的微血管并发症之一，亦是终末期肾病（end-stage renal disease）最常见的致病诱因。含三联基序（Tripartite motif-containing, TRIM）蛋白是一类庞大的E3泛素连接酶家族，可通过调控泛素-蛋白酶体系统参与蛋白质质量控制进程，但目前各类TRIM蛋白调控下游事件的具体分子机制尚未完全阐明。本研究旨在明确TRIM22在糖尿病肾病中的功能与作用机制。本研究通过高糖（high glucose, HG）诱导HK-2细胞及构建糖尿病db/db小鼠模型以模拟糖尿病肾病病理状态；分别采用细胞计数试剂盒-8（Cell Counting Kit-8）与流式细胞术检测细胞活力、细胞凋亡、线粒体活性氧水平及线粒体膜电位；通过苏木精-伊红（hematoxylin and eosin）、高碘酸希夫（periodic acid schiff）及马松染色（Masson staining）评估肾脏病理改变；采用免疫共沉淀（co-immunoprecipitation）分析TRIM22与视神经萎缩蛋白1（optic atrophy 1, OPA1）的结合情况；采用RNA免疫沉淀（RNA immunoprecipitation）检测TRIM22 5'非翻译区的N⁶-甲基腺嘌呤（m⁶A）修饰水平。临床样本分析显示，糖尿病肾病患者体内TRIM22呈高表达状态。敲低TRIM22可抑制高糖诱导的HK-2细胞凋亡与线粒体功能障碍；促进线粒体融合则可缓解TRIM22过表达引发的HK-2细胞凋亡、线粒体功能障碍及小鼠肾脏损伤。机制层面，TRIM22可与OPA1相互作用并诱导其泛素化修饰。威尔姆斯瘤1相关蛋白（Wilms tumor 1-associating protein, WTAP）可通过m⁶A阅读蛋白胰岛素样生长因子2 mRNA结合蛋白1（insulin-like growth factor 2 mRNA-binding protein 1, IGF2BP1）促进TRIM22的m⁶A修饰。进一步实验证实，TRIM22可通过与OPA1结合并诱导其泛素化修饰，进而抑制糖尿病肾病的进展；WTAP亦可通过IGF2BP1介导TRIM22的m⁶A修饰。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于糖尿病肾病（DN）的分子机制研究，通过实验数据揭示了TRIM22在DN中的关键作用：其高表达导致线粒体功能障碍，而WTAP介导的m6A修饰调控TRIM22表达。数据集包含细胞和动物模型实验文件（如图像和文档），支持TRIM22通过泛素化OPA1促进疾病进展的发现，为DN治疗提供了潜在靶点。