Department of Nephrology, Qingpu Branch of Zhongshan Hospital Affiliated to Fudan University, Shanghai, China.
J Cell Mol Med. 2020 Aug;24(15):8779-8788. doi: 10.1111/jcmm.15513. Epub 2020 Jun 28.
Diabetic nephropathy is a leading cause of end-stage renal disease globally. The vital role of circular RNAs (circRNAs) has been reported in diabetic nephropathy progression, but the molecular mechanism linking diabetic nephropathy to circRNAs remains elusive. In this study, we investigated the significant function of circ-AKT3/miR-296-3p/E-cadherin regulatory network on the extracellular matrix accumulation in mesangial cells in diabetic nephropathy. The expression of circ-AKT3 and fibrosis-associated proteins, including fibronectin, collagen type I and collagen type IV, was assessed via RT-PCR and Western blot analysis in diabetic nephropathy animal model and mouse mesangial SV40-MES13 cells. Luciferase reporter assays were used to investigate interactions among E-cadherin, circ-AKT3 and miR-296-3p in mouse mesangial SV40-MES13 cells. Cell apoptosis was evaluated via flow cytometry. The level of circ-AKT3 was significantly lower in diabetic nephropathy mice model group and mouse mesangial SV40-MES13 cells treated with high-concentration (25 mmol/L) glucose. In addition, circ-AKT3 overexpression inhibited the level of fibrosis-associated protein, such as fibronectin, collagen type I and collagen type IV. Circ-AKT3 overexpression also inhibited the apoptosis of mouse mesangial SV40-MES13 cells treated with high glucose. Luciferase reporter assay and bioinformatics tools identified that circ-AKT3 could act as a sponge of miR-296-3p and E-cadherin was the miR-296-3p direct target. Moreover, circ-AKT3/miR-296-3p/E-cadherin modulated the extracellular matrix of mouse mesangial cells in high-concentration (25 mmol/L) glucose, inhibiting the synthesis of related extracellular matrix protein. In conclusion, circ-AKT3 inhibited the extracellular matrix accumulation in diabetic nephropathy mesangial cells through modulating miR-296-3p/E-cadherin signals, which might offer novel potential opportunities for clinical diagnosis targets and therapeutic biomarkers for diabetic nephropathy.
糖尿病肾病是全球终末期肾病的主要病因。环状 RNA（circRNAs）在糖尿病肾病进展中的重要作用已有报道，但将糖尿病肾病与 circRNAs 联系起来的分子机制仍不清楚。在这项研究中，我们研究了 circ-AKT3/miR-296-3p/E-钙黏蛋白调控网络在糖尿病肾病系膜细胞细胞外基质积累中的重要功能。通过 RT-PCR 和 Western blot 分析，在糖尿病肾病动物模型和小鼠系膜 SV40-MES13 细胞中评估 circ-AKT3 和纤维化相关蛋白（包括纤连蛋白、I 型胶原和 IV 型胶原）的表达。荧光素酶报告实验用于研究小鼠系膜 SV40-MES13 细胞中 E-钙黏蛋白、circ-AKT3 和 miR-296-3p 之间的相互作用。通过流式细胞术评估细胞凋亡。糖尿病肾病小鼠模型组和高浓度（25mmol/L）葡萄糖处理的小鼠系膜 SV40-MES13 细胞中 circ-AKT3 的水平显著降低。此外，circ-AKT3 的过表达抑制了纤连蛋白、I 型胶原和 IV 型胶原等纤维化相关蛋白的水平。circ-AKT3 的过表达还抑制了高糖处理的小鼠系膜 SV40-MES13 细胞的凋亡。荧光素酶报告实验和生物信息学工具鉴定出 circ-AKT3 可以作为 miR-296-3p 的海绵，E-钙黏蛋白是 miR-296-3p 的直接靶标。此外，circ-AKT3/miR-296-3p/E-钙黏蛋白调节高浓度（25mmol/L）葡萄糖下小鼠系膜细胞的细胞外基质，抑制相关细胞外基质蛋白的合成。总之，circ-AKT3 通过调节 miR-296-3p/E-钙黏蛋白信号抑制糖尿病肾病系膜细胞细胞外基质的积累，为糖尿病肾病的临床诊断靶点和治疗生物标志物提供了新的潜在机会。
