Effects of 7-difluoromethy-5, 4'-dimethoxygenistein on stress urinary incontinence model in rats and its mechanisms

Abstract

To investigate the effects of 7-difluoromethy-5, 4'-dimethoxygenistein (DFMG) on stress urinary incontinence (SUI) model in Sprague Dawley (SD) rats and its possible mechanisms. Methods: SD rat model of SUI was established through simulating pregnancy, birth trauma and ovarian castration. The rats were divided into a normal control group, a SUI group, and a DFMG group at 10 or 20 mg/kg. They were treated with 10 mg/kg normal saline (NS), 10 mg/kg NS, 10 mg/kg DFMG and 20 mg/kg DFMG, respectively, via gastric gavage every other day. Maximal bladder capacity (MBC), leak point pressure (LPP), abdominal leak point pressure (ALPP), hematoxylin-eosin (HE) staining, and Masson staining were performed to detect the index for the model. MiR-26b and its down-stream gene phosphatase and tensin homolog deleted on chromosome 10 (PENT) mRNA in urethral sphincter muscles cells (USMCs) were analyzed by RT-PCR. The protein levels of PENT, phosphatidylinositol 3-kinase (PI3K), protein kinaseB (AKT), B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), cytochrome C(Cyt-c) and caspase-3 were examined by Western blot. The apoptotic rate of USMCs was determined by flow cytometry (FCM), and the proliferative rate of USMCs was examined by MTT assay. Results: The SD rat model of SUI was successfully established. HE staining and Masson staining showed that the pathological features of urethral sphincter were improved in the DFMG-treated groups compared with the SUI group. The urine dynamics indexes of model rats, such as MBC, LPP and ALPP, were improved (all P﹤0.05). The results of RT-PCR showed that the miR-26b mRNA was up-regulated (P﹤0.05) and PENT mRNA was down-regulated (P﹤0.05) in the DFMG-treated groups compared with the SUI group. Simultaneously, compared with the SUI group, the protein levels of PENT, Bax, Cyt-c and caspase-3 were down-regulated (all P﹤0.05) and the protein levels of PI3K, AKT and Bcl-2 protein were up-regulated (all P﹤0.05), accompanied by the decreased apoptotic rate of USMCs (P﹤0.05) and the increased proliferative rate of USMCs (P﹤0.05) in the DFMG-treated groups. Conclusion: The DFMG can significantly improve the symptoms of urinary dynamics, which might be related to the up-regulation of miR-26b expression and the regulation of PI3/AKT-Bcl-2/ Bax signaling pathways.