The Mechanoreceptor TRPV4 is Localized in Adherence Junctions of the Human Bladder Urothelium: A Morphological Study
The Mechanoreceptor TRPV4 is Localized in Adherence Junctions of the Human Bladder Urothelium: A Morphological Study
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DOI：
10.1016/j.juro.2011.04.107
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发表时间：
2011-09-01
影响因子：
6.6
通讯作者：
Schalken, Jack A.
中科院分区：
文献类型：
--
作者：
Janssen, Dick A. W.;Hoenderop, Joost G.;Schalken, Jack A.
目的：TRPV4（瞬时受体电位香草蛋白4通道）是一种参与不同感觉功能的非选择性阳离子通道，最近与膀胱机械感觉有关。我们研究了膀胱尿路上皮中TRPV4的细胞位置，并探索了TRPV4与尿路上皮粘附连接之间的分子联系。材料和方法：我们从3例癌症患者和2例非癌症患者的膀胱切除术中获得健康组织切片。除7只正常小鼠和7只TRPV4-/-小鼠的人体活检组织外，还使用了尿路上皮细胞系RT4。实验采用抗TRPV4多克隆抗体（针对大鼠TRPV4的n端）。采用免疫荧光、Western blot和免疫沉淀等方法研究了TRPV4与不同粘附连接组分之间的分子联系。结果：在尿路上皮黏附连接处附近发现TRPV4。结果在尿路上皮细胞系、人膀胱和小鼠膀胱中具有可比性。随后的免疫沉淀实验建立了TRPV4与α -catenin的分子连接，α -catenin是将E-cadherin与肌动蛋白-微丝网络连接的粘附连接的组成部分。结论：为TRPV4在人膀胱尿路上皮的定位提供了依据。TRPV4与尿路上皮细胞膜上的粘附连接有分子连接。TRPV4偶联到一个刚性的细胞内和细胞间结构网络，这与TRPV4可以通过膀胱拉伸激活的假设相一致。
Purpose: TRPV4 (transient receptor potential vanilloid 4 channel) is a nonselective cation channel involved in different sensory functions that was recently implicated in bladder mechanosensation. We investigated the cellular site of TRPV4 in bladder urothelium and explored a molecular connection between TRPV4 and urothelial adherence junctions.Materials and Methods: We obtained healthy tissues sections from cystectomy in humans due to cancer in 3 and noncancerous conditions in 2. Besides human biopsies tissues from 7 normal and 7 TRPV4-/-mice, and the urothelial cell line RT4 were also used. Experiments were done with polyclonal antibody against TRPV4 (against the N-terminus of rat TRPV4). A molecular connection between TRPV4 and different adherence junction components was investigated using immunofluorescence, Western blot and immunoprecipitation.Results: Results revealed TRPV4 on urothelial cell membranes near adherence junctions. Results were comparable in the urothelial cell line, human bladders and mouse bladders. Subsequent immunoprecipitation experiments established a molecular connection of TRPV4 to alpha-catenin, an integral part of the adherence junction that catenates E-cadherin to the actin-microfilament network.Conclusions: Results provide evidence for the location of TRPV4 in human bladder urothelium. TRPV4 is molecularly connected to adherence junctions on the urothelial cell membrane. TRPV4 coupling to a rigid intracellular and intercellular structural network would agree with the hypothesis that TRPV4 can be activated by bladder stretch.