Role of NADPH oxidase (NOX) in bladder functional and inflammatory changes in experimental cystitis

• Grant number: 19/00436-0
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): June 01, 2019
• Effective date (End): November 30, 2019
• Field of knowledge: Biological Sciences - Pharmacology - Autonomic Pharmacology
• Principal Investigator: Edson Antunes
• Grantee: Mariana Gonçalves de Oliveira Taranto
• Supervisor: Warren Hill
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Research place: Harvard University, Boston, United States
• Associated to the scholarship: 18/09765-3 - Voiding and prostatic dysfunction in middle-aged rats and obese mice: focus on NADPH oxidase (NOX), BP.PD

Abstract

Reactive-oxygen species (ROS) under optimal production regulate important physiological functions as cell proliferation and differentiation, vascular tone, innate immune response and inflammation. However, in situations where the production of ROS exceeds the cellular antioxidant mechanisms, several vascular and non-vascular-related diseases are installed, including those of the urogenital tract. The lower NO bioavailability and/or sGC oxidation induced by ROS contribute to the development of the overactive state of the bladder, urethra and prostate smooth muscles leading to urogenital tract disorders. The main enzymes responsible for ROS generation are uncoupled NOS, monoamine oxidase, xanthine oxidase and NADPH oxidase (NOX). The NOX family comprises seven members and is the only known enzyme with the sole function to produce ROS. Three isoforms of NOX (NOX 1, 2 and 4) are the best studied in animal models and human samples and related to ROS-induced vascular and non-vascular alterations. Our previous studies have shown increased levels of ROS in the bladder from cyclophosphamide-induced cystitis mice, along with a significant impairment of NO-sGC-cGMP-PKG signaling pathway. Pre-treatment with the sGC activator BAY 58-2667 not only restored ROS levels but also rescued the sGC-cGMP levels to that of the control animals. Therefore, in this project we will evaluate by means of in vivo assays and molecular techniques the following: i) to determine which NOX isoform(s) is(are) responsible for ROS production in the bladder from cyclophosphamide-induced cystitis mice; ii) to determine if blockade of ROS production by pharmacological NOX inhibition affect the sGC-cGMP pathway and the overactive state would be rescued in bladders from cyclophosphamide-induced cystitis mice and iii) to carry out treatment with NOX inhibitor in mouse cystitis and assess in vitro and in vivo assays. The development of this study will help to better understand the influence NADPH oxidase in ROS generation, its implications in inflammation and voiding dysfunction in mouse cystitis and guide us to propose a treatment to cystitis.