197 THE TRPV4 CATION CHANNEL MEDIATES STRETCH-EVOKED CA2+ INFLUX AND ATP RELEASE IN PRIMARY UROTHELIAL CELL CULTURES USING ORIGINAL CULTURE CELL STRETCH SYSTEM

Abstract

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology I1 Apr 2010197 THE TRPV4 CATION CHANNEL MEDIATES STRETCH-EVOKED CA2+ INFLUX AND ATP RELEASE IN PRIMARY UROTHELIAL CELL CULTURES USING ORIGINAL CULTURE CELL STRETCH SYSTEM Mochizuki Tsutomu, Hiroshi Nakagomi, Tatsuya Miyamoto, Isao Araki, Mitsuharu Yoshiyama, and Masayuki Takeda Mochizuki TsutomuMochizuki Tsutomu More articles by this author , Hiroshi NakagomiHiroshi Nakagomi More articles by this author , Tatsuya MiyamotoTatsuya Miyamoto More articles by this author , Isao ArakiIsao Araki More articles by this author , Mitsuharu YoshiyamaMitsuharu Yoshiyama More articles by this author , and Masayuki TakedaMasayuki Takeda More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.253AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The transient receptor potential vanilloid 4 (TRPV4), a possible mechanoreceptor, has been reported to be expressed in the urothelium and urinary bladder smooth muscle cells, and activation of TRPV4 by specific ligands leads to augmentation of bladder contraction amplitude in cystometry and induction or bladder over activity in vivo (J Clin Invest, 2007, J Pharmacol Exp Ther, 2007). However, whether urothelial TRPV4 is required for sensing mechanical stretch, or to what extent urothelial TRPV4 contributes to stretch-evoked ATP release, has not been precisely determined. In the present study, we examined the functional contribution of TRPV4 to stretch-dependent urothelial cell responses and to stretch-evoked adenosine triphosphate (ATP) release in vitro using an original uni-axial cell stretch system. METHODS Eight to12 weeks male WT (C57BL/6Cr) mice and TRPV4KO mice backcrossed on a C57BL/6Cr background were used. (1) RT-PCR method using mouse urothelial primary culture cells. (2) Immunofluorescent method using mouse whole bladder specimen and urothelial primary culture cells. (3) Ca2+-imaging system for the responses to application of 4alpha-phorbol 12, 13 didecanoate (4A-PDD), a TRPV4-selective agonist, and mechanical stretch stimulation in the urothelial primary culture cells. (4) Photon imaging system for direct measurement of ATP released from the urothelial primary cultures. RESULTS TRPV4 mRNA and protein were highly expressed in WT mouse urothelial cells, typically in the basal and intermediate layers, much lesser extent in other cell types of the bladder, but not in the TRPV4KO mice. Urothelial primary culture cells from WT mice, but not TRPV4KO mice, revealed a response to 4A-PDD. Stretch stimulation by our original cell-stretch system evoked intracellular Ca2+ increase in WT urothelial cells, but not in TRPV4KO cells. Potent ATP release occurred following stretch stimulation or 4A-PDD administration in WT urothelial cells, which was dramatically suppressed in TRPV4KO cells. CONCLUSIONS In the present study, we provided the evidence that TRPV4 channel is the candidate molecule involved in mechanosensory transduction in urinary bladder. Chuo, Japan© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e78 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mochizuki Tsutomu More articles by this author Hiroshi Nakagomi More articles by this author Tatsuya Miyamoto More articles by this author Isao Araki More articles by this author Mitsuharu Yoshiyama More articles by this author Masayuki Takeda More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...