MicroRNA-451 Modulates Autophagy-Related Signaling with Relevance to Renal Fibrosis in an Accelerated Mouse Model of...

Diabetic nephropathy is characterized by metabolic dysregulation, renal fibrosis, and impaired autophagy. MicroRNA-451 (miR-451) has been implicated in metabolic and stress-response pathways, but its role in diabetic kidney disease remains unclear. This study examined the effects of systemic miR-451 overexpression on renal injury and autophagy in BTBR ob/ob mice.

Wild-type (WT) and BTBR ob/ob (OB) mice were treated with miR-451 mimics. Body weight, blood glucose, and urine albumin were assessed for three consecutive weeks. Renal miR-451 expression was measured by qRT-PCR, while protein levels of YWHAZ, mTOR, and autophagy markers were analyzed by Western blotting. Renal fibrosis was evaluated using Masson's trichrome staining.

OB mice exhibited increased body weight, hyperglycemia, and albuminuria compared with WT controls. miR-451 treatment resulted in robust renal overexpression of miR-451 in OB treated mice (8.4-fold, p = 0.039) but did not normalize metabolic parameters. miR-451 overexpression significantly reduced renal expression of YWHAZ and mTOR. Histological analysis revealed increased glomerular fibrosis in OB mice, which was significantly attenuated following miR-451 treatment in WT-treated and OB-treated mice. In addition, miR-451 treatment increased expression of autophagy-related proteins ATG101 and Beclin-1 and reduced the LC3-II/I ratio, indicating altered autophagic signaling.

miR-451 overexpression attenuates renal fibrosis and modulates autophagy-associated pathways in diabetic kidney disease, independent of metabolic control, highlighting miR-451 as a potential therapeutic target for diabetic kidney disease.