1671 STRETCH-INIDUCED EXPRESSION OF HIF-1α HIF-2α AND VEGF IN BLADDER UROTHELIAL CELLS (BUC) FROM SUBJECTS WITH OVERACTIVE BLADDER (OAB)

Abstract

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Female Urology II1 Apr 20101671 STRETCH-INIDUCED EXPRESSION OF HIF-1α HIF-2α AND VEGF IN BLADDER UROTHELIAL CELLS (BUC) FROM SUBJECTS WITH OVERACTIVE BLADDER (OAB) Charlotte E. Christiaansen, Yan Sun, Yuchao Hsu, and Toby C. Chai Charlotte E. ChristiaansenCharlotte E. Christiaansen Rotterdam, Netherlands More articles by this author , Yan SunYan Sun Baltimore, MD More articles by this author , Yuchao HsuYuchao Hsu Baltimore, MD More articles by this author , and Toby C. ChaiToby C. Chai Baltimore, MD More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1495AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Previous studies have shown that hypoxia can change the working conditions of the bladder and negatively affects its acute and long-term function. It is also known that abnormalities of BUC may play a role in OAB pathophysiology. We hypothesized that OAB may increases bladder oxygen demands due to increased bladder activity (urinary frequency and/or detrusor overactivity) which results in increased stretch of the bladder. We investigated whether OAB BUC react differently than normal BUC when subjected to stretch by measuring expression of angiogenesis factors: hypoxia-inducible factor 1, alpha subunit (HIF-1α), hypoxia-inducible factor 2, alpha subunit (HIF-2α) and vascular endothelial growth factor (VEGF). METHODS Human BUC were cultured from cystoscopic urothelial biopsies. Normal and OAB BUC were stretched using an in vitro stretch device, the Flexcell. HIF-1α, HIF-2α and VEGF mRNA expression were analyzed using quantitative real-time PCR. Fluorescence activated cell sorting (FACS) was used to determine HIF-1α, HIF-2α, and VEGF protein expression. Furthermore, because VEGF is a known cytokine released by cells, quantitation of VEGF level in the supernatant of OAB and normal BUC after stretching was determined with ELISA. RESULTS mRNA levels for HIF-1α, HIF-2α and VEGF were significantly higher in the stretched OAB BUC compared to stretched normal BUC (HIF-1α, p = 0.023; HIF-2α, p = 0.027; VEGF, p = 0.00017). FACS analysis of protein expression of HIF-2α in stretched OAB BUC showed significantly higher levels than in the non-stretched OAB BUC (p= 0.01). The protein expression of HIF-1α and VEGF in stretched OAB BUC were not different compared to non-stretched OAB BUC. During stretch, OAB BUC released significantly greater VEGF than stretched normal BUC at 8hr (p = 0.031), 24 hr (p = 0.031), and 48 hr (p = 0.043) time points respectively. As a control experiment, stretched OAB BUC released significantly more VEGF compared to non-stretched OAB BUC at 48hr (p = 0.007) and 96hr (p = 0.021) time points respectively. CONCLUSIONS These results demonstrated that OAB BUC responded differently compared to normal BUC to stretch by increased expression of mRNA for HIF-1α, HIF-2α and VEGF. Furthermore, OAB BUC secreted more VEGF in response to stretch. These results showed that OAB BUC responded to stretch as if they were in hypoxic conditions. © 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e645 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Charlotte E. Christiaansen Rotterdam, Netherlands More articles by this author Yan Sun Baltimore, MD More articles by this author Yuchao Hsu Baltimore, MD More articles by this author Toby C. Chai Baltimore, MD More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...