MP28-14 PROTEASE-ACTIVATED RECEPTOR 4 INDUCES BLADDER PAIN THROUGH DISULFIDE HIGH MOBILITY GROUP BOX-1 ACTING ON RECEPTORS FOR ADVANCED GLYCATION ENDPRODUCTS

Abstract

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology I1 Apr 2016MP28-14 PROTEASE-ACTIVATED RECEPTOR 4 INDUCES BLADDER PAIN THROUGH DISULFIDE HIGH MOBILITY GROUP BOX-1 ACTING ON RECEPTORS FOR ADVANCED GLYCATION ENDPRODUCTS Dimitrios Kouzoukas, Fei Ma, Katherine Meyer-Siegler, Karin Westlund, David Hunt, and Pedro Vera Dimitrios KouzoukasDimitrios Kouzoukas More articles by this author , Fei MaFei Ma More articles by this author , Katherine Meyer-SieglerKatherine Meyer-Siegler More articles by this author , Karin WestlundKarin Westlund More articles by this author , David HuntDavid Hunt More articles by this author , and Pedro VeraPedro Vera More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1064AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Pain without obvious bladder pathology is a hallmark of Interstitial Cystitis / Painful Bladder Syndrome (IC/PBS). In a mouse model of bladder pain, urothelial protease activated receptor 4 (PAR4) stimulation causes pain without inflammation through macrophage migration inhibitory factor (MIF) release (Kouzoukas et al 2014). High mobility group box-1 (HMGB1), a ubiquitous nuclear non-histone DNA-binding protein, also mediates bladder pain, but not inflammation (Tanaka et al, 2014). Two redox states of all-thiol and disulfide HGMB1 respectively act through receptors for advanced glycation endproducts (RAGE) and toll-like receptor 4 (TLR4). Which HMGB1 form(s) contribute to bladder pain is unknown. We investigated whether: 1) bladder PAR4 stimulation causes urothelial HMGB1 release; 2) blocking MIF prevents urothelial HMGB1 release; 3) blocking HMGB1 prevents PAR4-induced hypersensitivity; 4) specific HMGB1 redox form causes pain, changes in micturition parameters and/or bladder inflammation; and 5) antagonizing specific HMGB1 receptors affect HMGB1-induced hypersensitivity. METHODS Female C57BL/6 mice were given intravesical PAR4 peptides (100 μM; 1 hr). Intraluminal fluid was collected and assayed for HMGB1, fluid parameters, abdominal hypersensitivity and histology were determined 24 hrs after pretreatment with HMGB1 inhibitor (glycyrrhizin: 50 mg/kg; i.p.), MIF blocker (ISO-1: 20 mg/kg; i.p.), specific HMGB1 redox forms (all-thiol or disulfide; 1, 2, 5, 10, 20, μg/150 μl; 1 hr), RAGE antagonist (FPS-ZM1; 10 mg/kg, i.p.), TLR4 antagonist (TAK-242; 3 mg/kg, i.p.), or vehicle. RESULTS PAR4-AP triggered urothelial HMGB1 release and Intravesical PAR4 induced abdominal hypersensitivity was prevented by blocking HMGB1. MIF inhibition blocked PAR4-mediated urothelial HMGB1 release. Intravesical disulfide HMGB1 (≥ 10 μg) instillation induced abdominal hypersensitivity, decreased micturition volume and increased voiding frequency. Thiol HMGB1 was ineffective. Systemic FPS-ZM1 fully and TAK-242 partially prevented disulfide HMGB1 (10 μg)-induced hypersensitivity. All doses of HMGB1 produced minimal to mild bladder edema and reactive changes. CONCLUSIONS Bladder PAR4 receptor stimulation induced urothelial HMGB1 release, mediated by MIF. Abdominal hypersensitivity, mediated by disulfide HGMB1 (not all-thiol), acted mainly through RAGE receptors. Urothelial MIF and HGMB1 receptors represent novel therapeutic targets for bladder pain conditions. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e376 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Dimitrios Kouzoukas More articles by this author Fei Ma More articles by this author Katherine Meyer-Siegler More articles by this author Karin Westlund More articles by this author David Hunt More articles by this author Pedro Vera More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...