MicroRNA-302b mitigates renal fibrosis via inhibiting TGF-β/Smad pathway activation

• Autor(a) principal: Sun,Mengkui
• Data de Publicação: 2021
• Outros Autores: Zhou,Wei, Yao,Fei, Song,Jianming, Xu,Yanan, Deng,Zhimei, Diao,Hongwang, Li,Shoulin
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Medical and Biological Research
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2021000300611
• topic: MicroRNA-302b; Renal fibrosis; Epithelial mesenchymal transition; TGF-β receptor 2; Unilateral ureteral obstruction

Renal fibrosis is one of the most significant pathological changes after ureteral obstruction. Transforming growth factor-β (TGF-β) signaling pathway plays essential roles in kidney fibrosis regulation. The aims of the present study were to investigate effects of microRNA-302b (miR-302b) on renal fibrosis, and interaction between miR-302b and TGF-β signaling pathway in murine unilateral ureteral obstruction (UUO) model. Microarray dataset GSE42716 was downloaded by retrieving Gene Expression Omnibus database. In accordance with bioinformatics analysis results, miR-302b was significantly down-regulated in UUO mouse kidney tissue and TGF-β1-treated HK-2 cells. Masson's trichrome staining showed that miR-302b mimics decreased renal fibrosis induced by UUO. The increased mRNA expression of collagen I and α-smooth muscle actin (α-SMA) and decreased expression of E-cadherin were reversed by miR-302b mimics. In addition, miR-302b up-regulation also inhibited TGF-β1-induced epithelial mesenchymal transition (EMT) of HK-2 cells by restoring E-cadherin expression and decreasing α-SMA expression. miR-302b mimics suppressed both luciferase activity and protein expression of TGF-βR2. However, miR-302b inhibitor increased TGF-βR2 luciferase activity and protein expression. Meanwhile, miR-302b mimics inhibited TGF-βR2 mRNA expression and decreased Smad2 and Smad3 phosphorylation in vivo and in vitro. Furthermore, over-expression of TGF-βR2 restored the miR-302b-induced decrease of collagen I and α-SMA expression. In conclusion, this study demonstrated that miR-302b attenuated renal fibrosis by targeting TGF-βR2 to suppress TGF-β/Smad signaling activation. Our findings showed that elevating renal miR-302b levels may be a novel therapeutic strategy for preventing renal fibrosis.