缺氧对膀胱平滑肌细胞缝隙连接蛋白表达的影响

Effects of cell hypoxia on connexins in unstable bladder smooth muscle cells

目的通过研究膀胱出口部分梗阻及缺氧环境下膀胱平滑肌细胞中缝隙连接蛋白表达的变化,探讨不稳定膀胱的发生规律。方法建立不稳定膀胱大鼠模型、体外正常大鼠膀胱平滑肌细胞并造成其细胞缺氧状态;采用RT-PCR和Western blot分析膀胱平滑肌细胞的缝隙连接蛋白的表达。结果不稳定膀胱组及缺氧组(15min、30min、1h)膀胱平滑肌细胞中Cx40、Cx43在mRNA及蛋白水平上均高于模型对照组及缺氧对照组(P<0.01),其中缺氧15min组Cx43的mRNA及蛋白表达量均较缺氧30min组、缺氧1h组高(P<0.01)。结论膀胱出口部分梗阻能引起平滑肌细胞缺氧与缝隙连接蛋白表达增多,平滑肌细胞缺氧也能引起缝隙连接蛋白表达增加。膀胱出口部分梗阻后导致的不稳定膀胱的发生可能与膀胱平滑肌细胞缺氧有着密切关系。

Objective To study the pathogenesis of unstable bladder with partial bladder outlet obstruction through the experiment based research on connexins in both unstable bladder group and cell hypoxia group. Methods Unstable bladder rat models were established and smooth muscle cells were cultured in vitro. Then cell anoxia was induced. RT-PCR and Western blot were used to quantify the connexins. Results The mRNA levels of Cx40, Cx43 and the Cx43 protein expressed in the smooth muscle cells from the unstable bladder group and cell hypoxia groups were all higher than those in the control groups （the sham-operation group and normoxia groups） （P〈0.01）. In the cell hypoxia groups, cells exposed to 15 min hypoxia expressed much higher Cx43 than the other two groups （P〈0.01）.Conclusion Partial bladder outlet obstruction which leads to unstable bladder might cause cell hypoxia and the increased expression of connexins. In our study, cell hypoxia also increased the expression of connexins. Therefore, we conclude that cell hypoxia might play a key role in connecting partial bladder outlet obstruction and unstable bladder.