MicroRNA-204-5p Ameliorates Renal Injury via Regulating Keap1/Nrf2 Pathway in Diabetic Kidney Disease

Jiajia Dong,1 Mengyu Liu,1 Yawei Bian,1,2 Wei Zhang,1 Chen Yuan,1 Dongyun Wang,1 Zihui Zhou,1 Yue Li,1 Yonghong Shi1,2 1Department of Pathology, Hebei Medical University, Shijiazhuang, People’s Republic of China; 2Hebei Key Laboratory of Kidney Disease, Shijiazhuang, People’s Republic of ChinaCorrespondence: Yonghong Shi, Department of Pathology, Hebei Medical University, No. 361 East Zhongshan Road, Shijiazhuang, Hebei, 050017, People’s Republic of China, Tel +86 311 86266647, Email yonghongshi@163.comBackground: Diabetic kidney disease (DKD) is characterized by renal fibrosis, and the pathogenesis of renal fibrosis is still not definitely confirmed. MiR-204-5p plays an important role in the regulation of fibrosis, autophagy and oxidative stress. In this study, we aimed to investigate the role of miR-204-5p on renal damage in diabetic kidneys and the underlying mechanisms involved.Methods: In vivo, AAV-Ksp-miR-204-5p mimics were injected into mice via tail vein. In vitro, high glucose-induced HK-2 cells were treated with miR-204-5p inhibitor, miR-204-5p mimics, ATG5 siRNA, tertiary butyl hydroquinone (TBHQ), ML385, or 3-Methyladenine (3-MA). FISH and qRT-PCR were used to detect miR-204-5p expression. The expressions of protein and mRNA were detected by Western blotting, immunofluorescence, immunohistochemistry and qRT-PCR. The concentration of fibronectin in HK-2 cells culture medium was detected by ELISA.Results: The expression of miR-204-5p in diabetic kidneys was significantly inhibited than that in control group. Delivering miR-204-5p mimics increased miR-204-5p expression, improved renal function, inhibited renal fibrosis and oxidative stress, and restored autophagy in db/db mice. In vitro, the expression of miR-204-5p was inhibited by HG treatment in HK-2 cells. MiR-204-5p mimics effectively increased miR-204-5p expression and reduced fibronectin and collagen I expression, restored autophagy dysfunction, and increased Nrf2 expression, whereas these alte