Authors

Da He, Zengsi Wang, Li Cheng, Yonglong Min, Dongdong Mao, Fei Xiong#

Departments

Department of Nephrology, Wuhan No.1 Hospital, Wuhan, PR China

Abstract

Objective: To explore the mechanism of miR-21 in promoting the occurrence and development of DN by inhibiting the level of SnoN protein and regulating the TGF-β1/Smad3 signalling pathway. 

Methods: After one week of adaptive feeding, 54 rats were randomly divided into a normal-glucose group (NG), a high-glucose group (HG), a normal-glucose miR-21 treatment group (NG+Phage, NG+sponge), and a high glucose miR-21 treatment group (HG+p-miR-21, HG+Phage, HG+SonN shRNA, HG+BMP-7, HG+BMP-7+SonN shRNA), HG sponge. The pathological changes of renal tissue, Western imprinting, SonD, TGB-β1, p-Smad3 protein expression, miR-21, SnoN protein expression, miR-21 expression in NRK-52E cells, the effect of overexpression of miR-21 in NRK-52E cells on the expression of SnoN protein, the increase and decrease of SnoD protein expression in NRK cells and the expression of miR-21 in NRK-52E cells were compared. 

Results: The renal tissue of rats in each group was observed at 12 weeks. The expression of miR-21mRNA and SnoN mRNA in the DM group was significantly higher than that in the NC group (P<0.05). The renal tubular epithelial cells were arranged neatly and no obvious pathological changes were found in the DM group. In addition, the renal tubular lumen was obviously dilated, the renal tubules were hyperaemic and swelling, inflammatory infiltration and renal fibrosis were observed, expression of miR-21mRNA was significantly higher and the expression of SnoN mRNA was significantly lower in the DM group than that in the NC group (P<0.05). The expression of miR-21mRNA was also significantly higher and the expression of SnoN mRNA was significantly lower in the DM group than that in NC group (P<0.05). The results of immunoblotting showed that the expression of SonN protein in the DM group was significantly lower than that in NC group, and the expression of TGB-β1 and p-Smad3 protein in the NC group was significantly higher than that in the NC group (P<0.05). After overexpression of miR-21, the expression of miR-21mRNA in the NG group and HG group was significantly increased, and the expression of miR-21mRNA in the HG group was significantly higher than that in the NG group (P<0.05). After overexpression of miR-21, the expression of SnoN mRNA in the HG+p-miR-21 group was significantly lower than that in other groups (P<0.05). Compared with the NG group, the expression of SnoN mRNA in the HG group was up-regulated, but the expression of SnoN protein was decreased, the difference was statistically significant (P<0.05), and the expression of SnoN mRNA and SnoN protein in the (HG+BMP-7 group was significantly higher than that in the HG group (P<0.05). Compared with the NG group, the expression of miR-21 in other high-glucose groups was significantly increased (P<0.05). Compared with the HG group, the HG BMP-7 group decreased significantly (P<0.05). 

Conclusion: miR-21 is involved in the progress of DN by inhibiting the level of SnoD protein, which may be realised by regulating the TGF-β1/Smads3 signalling pathway, activating the GF-β1/Smads3 signal passing through, promoting the fibrosis of DN, and playing an important role in the diagnosis of DN. 

Keywords

Diabetic nephropathy, miR-21, SnoN, TGF-β1/Smad3 signalling pathway.

DOI:

10.19193/0393-6384_2020_3_249