Department of Nephrology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, No.261, Huansha Road, Hangzhou, Zhejiang, 310006, P. R. China.
Appl Biochem Biotechnol. 2024 Apr;196(4):1863-1875. doi: 10.1007/s12010-023-04645-0. Epub 2023 Jul 13.
Podocyte injury is very important process in diabetic nephropathy (DN) progression. Circular RNA (circRNA) takes part in regulating the advancement of DN. Herein, we explored the role and mechanism of circGAB1 in DN progression.
The abundances of circGAB1, microRNA-346 (miR-346) and mitogen-activated protein kinase 6 (MAPK6) were detected by qRT-PCR in DN serum samples and podocyte HGPC. Moreover, cell viability and apoptosis were determined using CCK8 assay and flow cytometry. Also, the protein levels of MAPK6, proliferation-related markers and apoptosis-related markers were analyzed by western blot. ELISA assay was used to measure the levels of inflammatory factors, and corresponding kits were used to detect the levels of oxidative stress-related markers. The relationship between miR-346 and circGAB1 or MAPK6 was distinguished by dual-luciferase reporter assay.
CircGAB1 expression was increased in DN serum samples and HG-treated HGPC cells. CircGAB1 knockdown inhibited HG-induced apoptosis, inflammatory response and oxidative stress in HGPC cells. In terms of mechanism, circGAB1 sponged miR-346, and miR-346 targeted MAPK6. The inhibition effect of circGAB1 knockdown on HG-induced podocyte injury could be reversed by miR-346 inhibitor. Moreover, miR-346 overexpression repressed HG-induced podocyte injury by targeting MAPK6. CircGAB1 served as miR-346 sponge to positively regulate MAPK6.
CircGAB1 contributed to podocyte injury through mediating miR-346/MAPK6 axis, suggesting that circGAB1 might promote DN progression.
足细胞损伤是糖尿病肾病（DN）进展的重要过程。环状 RNA（circRNA）参与调节 DN 的进展。在此，我们探讨了 circGAB1 在 DN 进展中的作用和机制。
通过 qRT-PCR 检测 DN 血清样本和高糖（HG）处理的足细胞 HGPC 中的 circGAB1、微小 RNA-346（miR-346）和丝裂原活化蛋白激酶 6（MAPK6）的丰度。此外，通过 CCK8 测定和流式细胞术测定细胞活力和凋亡。还通过 Western blot 分析 MAPK6、增殖相关标志物和凋亡相关标志物的蛋白水平。ELISA 测定用于测量炎症因子的水平，相应的试剂盒用于检测氧化应激相关标志物的水平。通过双荧光素酶报告基因实验区分 miR-346 与 circGAB1 或 MAPK6 的关系。
CircGAB1 在 DN 血清样本和 HG 处理的 HGPC 细胞中表达增加。CircGAB1 敲低抑制了 HG 诱导的 HGPC 细胞凋亡、炎症反应和氧化应激。就机制而言，circGAB1 海绵吸附 miR-346，而 miR-346 靶向 MAPK6。circGAB1 敲低对 HG 诱导的足细胞损伤的抑制作用可以通过 miR-346 抑制剂逆转。此外，miR-346 通过靶向 MAPK6 抑制 HG 诱导的足细胞损伤。CircGAB1 通过介导 miR-346/MAPK6 轴促进足细胞损伤。
CircGAB1 通过介导 miR-346/MAPK6 轴促进足细胞损伤，表明 circGAB1 可能促进 DN 进展。
