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 α-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.
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 ratTRPV4). 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 α-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.
Authors: L A Birder; M Ruggieri; M Takeda; G van Koeveringe; S Veltkamp; C Korstanje; B Parsons; C H Fry Journal: Neurourol Urodyn Date: 2012-01-24 Impact factor: 2.696
Authors: Luke Grundy; Andrea M Harrington; Joel Castro; Sonia Garcia-Caraballo; Annemie Deiteren; Jessica Maddern; Grigori Y Rychkov; Pei Ge; Stefanie Peters; Robert Feil; Paul Miller; Andre Ghetti; Gerhard Hannig; Caroline B Kurtz; Inmaculada Silos-Santiago; Stuart M Brierley Journal: JCI Insight Date: 2018-10-04