Abstract: Objective To explore the effect of reducing bladder TGF-β1 expression with RNA interference(RNAi) on neurogenic bladder(NB). Methods Forty-eight female rats were evenly divided into sham, T10 transaction, LV-vector and LV-shTGF-β1 groups. The sham group underwent sham operation of T10 spinal cord transection, and the other three groups underwent spinal cord transection. The bladder wall was injected immediately after the operation. The first two groups were injected with 0.9% NaCl, the LV-vector group was the control lentivirus, and the LV-shTGF-β1 group was TGF-β1 RNAi lentivirus. On the 28th day after operation, cystometry and bladder weighing were performed, the bladder tissue was stained with HE and Masson, and the expression of detrusor TGF-β1 was detected by immunohistochemistry, RT-qPCR and Western blot. Results In the three groups with spinal cord transection compared with the sham group, the frequency and amplitude of detrusor over activity were significantly increased (P＜0.01), the bladder capacity was significantly reduced (P＜0.05), and the bladder weight, the detrusor interstitial percentage and TGF-β1 expression were significantly increased (P＜0.05). The T10 transection group had no significant difference compared with the LV-vector group. In the LV-shTGF-β1 group compared with the T10 transection group, the frequency and amplitude of detrusor over activity were significantly reduced (P＜0.01), the bladder capacity was significantly increased (P＜0.01), and the bladder weight, the detrusor interstitial percentage and TGF- β1 expression were significantly reduced (P＜0.05). Conclusions Reducing bladder TGF-β1 expression with RNAi can improve detrusor over activity and bladder fibrosis in rats with spinal cord injury.

Key words: spinal cord injury, detrusor over activity, bladder fibrosis, RNA interference(RNAi), TGF-β1