MicroRNA-27a Suppresses Detrusor Fibrosis in Streptozotocin-Induced Diabetic Rats by Targeting PRKAA2 Through the TGF-β1/Smad3 Signaling Pathway

We examined the effects of microRNA-27a (miR-27a) on detrusor fibrosis in streptozotocin (STZ)-induced diabetic rats. Eighty healthy Sprague-Dawley (SD) rats were randomly allocated into control, diabetic, miR-27a mimics, mimics control, miR-27a inhibitors, inhibitors control, siRNA-PRKAA2 (siPRKAA2) and inhibitors + siPRKAA2 groups (the latter 7 groups were established as STZ-induced diabetic rat models and treated in different manners). Detrusor cell apoptosis in bladder tissues was determined through terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) staining. Detrusor cells were assigned to the blank, miR-27a mimics, mimics control, miR-27a inhibitors, inhibitors control, siPRKAA2 and inhibitors + siPRKAA2 groups. Flow cytometry determined the cell cycle stage and apoptosis. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blotting (WB) were used to assess the expression of miR-27a, PRKAA2, TGF-β1, Smad3, p-Smad3, fibronectin (FN), connective tissue growth (CTGF), and collagen-I (COL-I) in tissues and cells. Compared with the control group, the diabetic, miR-27a mimics, and siPRKAA2 groups showed reduced weight and PRKAA2 expression, but elevated blood glucose, serum creatinine (sCr), blood urea nitrogen (BUN), cell apoptosis, and expression of TGF-β1, Smad3, FN, COL-I, CTGF, and p-Smad3. The opposite trend was observed in the miR-27a inhibitors group. PRKAA2 is a target gene of miR-27a. Compared to the blank group, the miR-27a mimics and siPRKAA2 groups indicated markedly increased TGF-β1, Smad3, FN, COL-I, CTGF and p-Smad3 expression; decreased PRKAA2 expression; and increased cell apoptosis. The miR-27a inhibitors group showed the opposite trend. These results indicate that miR-27a may contribute to detrusor fibrosis in STZ-induced diabetic rats by targeting PRKAA2 via the TGF-β1/Smad3 signaling pathway.