MP42-15 THE UROTHELIUM IS THE MOST PREDOMINANT TISSUE IN THE BODY FOR SUPEROXIDE PRODUCTION: KEY ROLE OF NADPH OXIDASES

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology I1 Apr 2017MP42-15 THE UROTHELIUM IS THE MOST PREDOMINANT TISSUE IN THE BODY FOR SUPEROXIDE PRODUCTION: KEY ROLE OF NADPH OXIDASES Max Roberts, Josephine Amosah, Lisa Adjei, Guiping Sui, Rui Wu, Simon Archer, Jonathan Johnston, Michael Ruggieri, and Changhao Wu Max RobertsMax Roberts More articles by this author , Josephine AmosahJosephine Amosah More articles by this author , Lisa AdjeiLisa Adjei More articles by this author , Guiping SuiGuiping Sui More articles by this author , Rui WuRui Wu More articles by this author , Simon ArcherSimon Archer More articles by this author , Jonathan JohnstonJonathan Johnston More articles by this author , Michael RuggieriMichael Ruggieri More articles by this author , and Changhao WuChanghao Wu More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1304AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recognition of the urothelium as a new sensory structure has significantly advanced our understanding of bladder function. Key to further progress is the identification of novel pathological regulators in this tissue. Oxidative stress is a fundamental pathological mediator; ROS generating enzyme NADPH oxidase (Nox enzyme) has attracted intense interest recently as it is the only enzyme that produces ROS as its sole function and can be targeted without compromising normal biochemical oxidation. Our recent pilot study provided initial evidence for the presence of such system in bladder urothelium and its potential functional significance. This study aimed firstly to define the importance of urothelial superoxide production in the body and secondly to dissect the enzymatic sources of superoxide production in the bladder. METHODS C57BL/6J mice were euthanized. Bladder and other types of tissue were isolated. Lucigenin-enhanced chemiluminescence quantified superoxide production in live tissue. Western blot determined Nox subtype expressions. RESULTS Superoxide production in bladder mucosa (RLU/mg tissue: 536.8±104.8, mean±SEM) was many folds as high as those in detrusor muscle (21.8±3.8, n=15, p<0.01), aorta (67.2±26.6, n=7, p<0.05), brain (9.4±1.7, n=6, p<0.01), kidney (84.3±23.0, n=6, p<0.05), ventricle (21.8±3.8, n=6, p<0.01) and liver (80.8±12.9, n=7, p<0.05). NADPH oxidase inhibitor diphenyleneiodonium (DPI, 20µM)reduced superoxide production to 10.8±3.4 % of control (n=6, p<0.01) in bladder mucosa and to 30.8±8.4% of control (n=6, p<0.01) in detrusor. Mitochondria de-coupler FCCP (10µM) suppressed superoxide production to 51.8±10.5 % of control (n=6; p<0.01) in bladder mucosa and to 59.8±10.4 % of control (n=6, p<0.05) in detrusor. Xanthine oxidase inhibitor oxypurinol (100µM) produced no significant effect in bladder mucosa (87.9±17.4 % of control, n=6, p>0.05) but a small inhibition in detrusor (78.0±6.6% of control). Western blot showed specific bands for Nox1, Nox2 and Nox4 but no Nox3 expression in bladder mucosa and detrusor with significantly higher expression in bladder mucosa (p<0.05, n=4-6). CONCLUSIONS These data demonstrate for the first time that the urothelium is the most active tissue for superoxide production in the body. Nox enzymes are the main enzymatic source for superoxide in bladder. The main Nox subtypes are Nox1, Nox2 and Nox4, mainly located in the urothelium. Exceptionally high levels of Nox-driven superoxide explain why bladder urothelium is prone to oxidative stress, inflammation and sensory dysfunction. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e549-e550 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Max Roberts More articles by this author Josephine Amosah More articles by this author Lisa Adjei More articles by this author Guiping Sui More articles by this author Rui Wu More articles by this author Simon Archer More articles by this author Jonathan Johnston More articles by this author Michael Ruggieri More articles by this author Changhao Wu More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...