Department of Urology, Institute of Urology, Laboratory of Reconstructive Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
Department of Urology, Institute of Urology, Laboratory of Reconstructive Urology, West China Hospital, Sichuan University, Chengdu, Sichuan, PR China.
Arch Biochem Biophys. 2021 May 15;702:108674. doi: 10.1016/j.abb.2020.108674. Epub 2020 Nov 12.
Extracellular matrix (ECM) remodeling is strongly associated with pathological changes induced by bladder outlet obstruction (BOO). In this study, we investigated the role of interleukin-6 (IL-6) in mechanical stretch-induced ECM remodeling of bladder smooth muscle. To construct a BOO animal model, the urethras of female Sprague-Dawley rats were partially ligated. In addition, increased hydrostatic pressure and mechanical stretching were applied to human bladder smooth muscle cells (HBSMCs) as an in vitro model. The expression of rat inflammatory genes was analyzed using DNA microarrays. We used quantitative RT-PCR (qRT-PCR) and immunohistochemical staining to detect IL-6 in the bladder smooth muscle of rats. To determine the specificity of IL-6, small interfering ribonucleic acid (siRNA) transfection and IL-6 receptor inhibitor (SC144) were applied to HBSMCs. qRT-PCR with siRNA transfection was also used to determine the specificity of downstream signaling. Moreover, western blotting was conducted to verify the expression results. In the animal model, the expression of ECM components and inflammatory genes was significantly upregulated. The expression of IL-6 was increased at both the mRNA level and the protein level in BOO rats. In vitro, hydrostatic pressure, and mechanical stretching both promoted MMP7 and MMP11 expression. Additionally, downregulation of collagen III occurred in both the hydrostatic pressure group and the mechanical stretch group. However, the expression of fibronectin exhibited opposing patterns between the hydrostatic pressure and mechanical stretch groups. The application of targeted siRNA transfection and an inhibitor (SC144) that targeted IL-6 significantly reversed the changes in MMP7 and MMP11 under mechanical stress and partially increased the expression of collagen III and fibronectin. In summary, IL-6 participated in the ECM remodeling of HBSMCs under mechanical stress, indicating that IL-6 may play an essential role in BOO. .
细胞外基质（ECM）重塑与膀胱出口梗阻（BOO）引起的病理变化密切相关。在这项研究中，我们研究了白细胞介素 6（IL-6）在机械拉伸诱导的膀胱平滑肌 ECM 重塑中的作用。为了构建 BOO 动物模型，部分结扎雌性 Sprague-Dawley 大鼠的尿道。此外，作为体外模型，向人膀胱平滑肌细胞（HBSMC）施加增加的静水压力和机械拉伸。使用 DNA 微阵列分析大鼠炎症基因的表达。我们使用定量 RT-PCR（qRT-PCR）和免疫组织化学染色来检测大鼠膀胱平滑肌中的 IL-6。为了确定 IL-6 的特异性，应用小干扰核糖核酸（siRNA）转染和 IL-6 受体抑制剂（SC144）处理 HBSMC。还使用 siRNA 转染的 qRT-PCR 来确定下游信号的特异性。此外，进行 Western 印迹以验证表达结果。在动物模型中，ECM 成分和炎症基因的表达显著上调。BOO 大鼠中 IL-6 的表达在 mRNA 水平和蛋白水平均增加。在体外，静水压力和机械拉伸均促进 MMP7 和 MMP11 的表达。此外，胶原 III 在静水压力组和机械拉伸组中均下调。然而，纤连蛋白在静水压力组和机械拉伸组中的表达呈相反模式。靶向 siRNA 转染和针对 IL-6 的抑制剂（SC144）的应用显著逆转了机械应激下 MMP7 和 MMP11 的变化，并部分增加了胶原 III 和纤连蛋白的表达。总之，IL-6 参与了机械应激下 HBSMC 的 ECM 重塑，表明 IL-6 可能在 BOO 中起重要作用。
