Chai Liyin, Liu Zhengyang, Zeng Jun, Gong Li, Xiang Sha, Yu Jing, Sun Haili, Wen Chaolin, Wang Fang, Li Ning, Shen Bingbing, Mei Mei
Department of Nephrology, Chongqing University Central Hospital (Chongqing Emergency Medical Center), Chongqing Key Laboratory of Emergency Medicine, School of Medicine, Chongqing University, Chongqing, 400014, China.
Department of Nephrology & Rheumatology, Chongqing University Shapingba Hospital, People's Hospital of Shapingba District, Chongqing, 400030, China.
Cell Biochem Biophys. 2025 Jun;83(2):2253-2263. doi: 10.1007/s12013-024-01636-8. Epub 2024 Dec 4.
Diabetic nephropathy (DN) is a serious diabetic complication. Renal tubular damage is an important aspect of DN. Increased apolipoprotein C1 (Apoc1) has been confirmed in serum of patients with DN. The exact mechanism of Apoc1 in DN is unclear as yet. We aimed to elaborate the molecular mechanism underlying high glucose (HG)-induced renal tubular epithelial damage. In this content, a DN mouse model was established to assess renal damage. Apoc1 and Clusterin expression in renal tissue was detected using immunoblotting and immunofluorescence staining. In vitro, human kidney proximal tubular epithelial cells (HK-2 cells) were exposed to HG to simulate the DN model. After Apoc1 and/or Clusterin knockdown, HK-2 cell viability under HG conditions was detected using CCK-8 assay. DCFH-DA staining was used to examine the production of intracellular reactive oxygen species (ROS). MDA and SOD levels were tested by kits. Moreover, cell apoptosis was measured using TUNEL staining. Immunoblotting was employed to evaluate the expression of proteins. Additionally, the binding between Apoc1 and Clusterin was analyzed using co-immunoprecipitation experiments. Our data revealed that Apoc1 expression was upregulated while Clusterin expression was downregulated in renal tissue of DN mice and HG-treated HK-2 cells. Apoc1 knockdown alleviated oxidative stress and apoptosis in HG-treated HK-2 cells. Importantly, Apoc1 could bind to Clusterin and regulate Clusterin expression in HK-2 cells. Finally, Clusterin silencing blocked the influences of Apoc1 knockdown on the oxidative stress and apoptosis in HK-2 cells under HG conditions. Collectively, Apoc1 knockdown exerts potential anti-DN effects by binding to Clusterin to alleviate HG-induced renal tubular damage, suggesting that Apoc1/Clusterin can be used as a valuable therapeutic target for DN.
糖尿病肾病（DN）是一种严重的糖尿病并发症。肾小管损伤是DN的一个重要方面。已证实在DN患者血清中载脂蛋白C1（Apoc1）升高。目前Apoc1在DN中的确切机制尚不清楚。我们旨在阐述高糖（HG）诱导肾小管上皮损伤的分子机制。在此研究中，建立了DN小鼠模型以评估肾脏损伤。采用免疫印迹和免疫荧光染色检测肾组织中Apoc1和簇集蛋白（Clusterin）的表达。在体外，将人肾近端小管上皮细胞（HK-2细胞）暴露于HG中以模拟DN模型。在敲低Apoc1和/或Clusterin后，使用CCK-8法检测HG条件下HK-2细胞的活力。采用2',7'-二氯二氢荧光素二乙酸酯（DCFH-DA）染色检测细胞内活性氧（ROS）的产生。通过试剂盒检测丙二醛（MDA）和超氧化物歧化酶（SOD）水平。此外，采用末端脱氧核苷酸转移酶介导的缺口末端标记（TUNEL）染色检测细胞凋亡。采用免疫印迹评估蛋白表达。另外，使用免疫共沉淀实验分析Apoc1与Clusterin之间的结合。我们的数据显示，在DN小鼠肾组织和HG处理的HK-2细胞中，Apoc1表达上调而Clusterin表达下调。敲低Apoc1可减轻HG处理的HK-2细胞中的氧化应激和凋亡。重要的是，Apoc1可与Clusterin结合并调节HK-2细胞中Clusterin的表达。最后，沉默Clusterin可阻断敲低Apoc1对HG条件下HK-2细胞氧化应激和凋亡的影响。总体而言，敲低Apoc1通过与Clusterin结合减轻HG诱导的肾小管损伤，发挥潜在的抗DN作用，提示Apoc1/Clusterin可作为DN有价值的治疗靶点。
