Mp59-10 Pannexin 1 Channels Involvement in Ic/BPS Pathophysiology: Insights From in Vivo and in Vitro Studies

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Basic Research & Pathophysiology (MP59)1 May 2024MP59-10 PANNEXIN 1 CHANNELS INVOLVEMENT IN IC/BPS PATHOPHYSIOLOGY: INSIGHTS FROM IN VIVO AND IN VITRO STUDIES Anna Dukhovich, Whitney Clearwater, Marcia Urban-Maldonado, and Sylvia Suadicani Anna DukhovichAnna Dukhovich , Whitney ClearwaterWhitney Clearwater , Marcia Urban-MaldonadoMarcia Urban-Maldonado , and Sylvia SuadicaniSylvia Suadicani View All Author Informationhttps://doi.org/10.1097/01.JU.0001009476.18935.3b.10AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Several factors are implicated in Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) etiology, including urothelial barrier dysfunction. A leaky urothelium exposes bladder tissues to high urinary K+, which induces release of signaling molecules, such as ATP, that contributes to emergence of urinary frequency, urgency and bladder hypersensitivity by activating suburothelial sensory fibers. Pannexin 1 (Panx1) channels are involved in bladder sensation by mediating mechanosensitive urothelial ATP release. They are also activated by high K+, which may implicate them in IC/BPS symptoms associated with urothelial damage. To test this hypothesis, we used an in vivo mouse model of constant illumination stress (CIS) that induces urothelial desquamation and simulated exposure of urothelial cells to high K+ using a novel immortalized cell line. METHODS: Wildtype (WT) and Panx1-deficient (Panx1KO) female mice were assigned to control (12 h/day illumination) or CIS (96hrs constant illumination) groups. Urinary frequency (UF) was quantified using voided stain on paper (VSOP) before and after 96hrs-CIS. Panx1 activation by bladder distension was mimicked in vitro by exposing immortalized mouse urothelial cells (mUC2-hTERT) to hypotonic shock (25% and 50%). Urothelial barrier disruption was mimicked by exposing mUC2-hTERT to 10 mM K+. Panx1-mediated ATP release and Yo-Pro-1 (10 µM) dye uptake were determined in absence and presence of BB-FCF (10 µM; Panx1 blocker). Data were compared pairwise using the Mann-Whitney test. RESULTS: Exposure to 96hrs-CIS induced 4.0-fold increase in UF of WT mice (WT-CIS vs WT-Ctrl: 4.11±0.68-fold; n=15; p<0.001). This effect of stress on UF was blunted in Panx1-deficient mice (Panx1KO-CIS vs Panx1KO-Ctrl: 1.90±0.31-fold; n=9; p=0.04). Mechanical stimulation of mUC2-hTERT by 25% and 50% hypotonic shock or high K+ induced ATP release in amounts that were 3- to 4.5-fold higher than non-stimulated controls (p<0.05). These responses were blunted by the Panx1 channel blocker BB-FCF. Consistent with these findings, Yo-Pro dye uptake by mUC2-hTERT cells was higher when cells were mechanically stimulated in the presence of high K+ (compared to hypo 25%, p<0.0012; hypo 50%, p<0.0001, n=20 cells/field, 10 fields/dish). CONCLUSIONS: These findings support the involvement of Panx1 channels in mechanisms whereby urothelial barrier breach can lead to urinary IC/BPS symptoms by amplifying urothelial ATP release and signaling. These results provide basis for future preclinical studies to evaluate the potential use of Panx1 blockers to manage IC/BPS. Source of Funding: DoD W81XWH-21-1-0465 © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e961 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Anna Dukhovich More articles by this author Whitney Clearwater More articles by this author Marcia Urban-Maldonado More articles by this author Sylvia Suadicani More articles by this author Expand All Advertisement PDF downloadLoading ...