title: Soluble guanylyl cyclase (sGC) degradation and impairment of nitric oxide-mediated responses in urethra from obese mice: reversal by the sGC activator BAY 60-2770.
abstract: Obesity has emerged as a major contributing risk factor for overactive bladder (OAB), but no study examined urethral smooth muscle (USM) dysfunction as a predisposing factor to obesity-induced OAB. This study investigated the USM relaxant machinery in obese mice and whether soluble guanylyl cyclase (sGC) activation with BAY 60-2770 [acid 4-({(4-carboxybutyl) [2-(5-fluoro-2-{[4-(trifluoromethyl) biphenyl-4-yl] methoxy} phenyl) ethyl] amino} methyl) benzoic] rescues the urethral reactivity through improvement of sGC-cGMP (cyclic guanosine monophosphate) signaling. Male C57BL/6 mice were fed for 12 weeks with a high-fat diet to induce obesity. Separate groups of animals were treated with BAY 60-2770 (1 mg/kg per day for 2 weeks). Functional assays and measurements of cGMP, reactive-oxygen species (ROS), and sGC protein expression in USM were determined. USM relaxations induced by NO (acidified sodium nitrite), NO donors (S-nitrosoglutathione and glyceryl trinitrate), and BAY 41-2272 [5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine] (sGC stimulator) were markedly reduced in obese compared with lean mice. In contrast, USM relaxations induced by BAY 60-2770 (sGC activator) were 43% greater in obese mice (P < 0.05), which was accompanied by increases in cGMP levels. Oxidation of sGC with ODQ [1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one] (10 μM) potentiated BAY 60-2770-induced USM responses in the lean group. Long-term oral BAY 60-2770 administration fully prevented the impairment of USM relaxations in obese mice. Reactive-oxygen species (ROS) production was enhanced, but protein expression of β1 second guanylate cyclase subunit was reduced in USM from obese mice, both of which were restored by BAY 60-2770 treatment. In conclusion, impaired USM relaxation in obese mice is associated with ROS generation and down-regulation of sGC-cGMP signaling. Prevention of sGC degradation by BAY 60-2770 ameliorates the impairment of urethral relaxations in obese mice.
authors.affiliation: Departments of Pharmacology (E.C.A., L.O.L., F.H.S., C.B.M.S., F.B.C., F.Z.M., G.D.N., E.A.) and Anatomy, Cellular Biology, Physiology, and Biophysics (A.P.C.D.), University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Eduardo C
authors.initials: EC
authors.lastname: Alexandre
authors.forename: Luiz O
authors.initials: LO
authors.lastname: Leiria
authors.forename: Fábio H
authors.initials: FH
authors.lastname: Silva
authors.forename: Camila B
authors.initials: CB
authors.lastname: Mendes-Silvério
authors.forename: Fabiano B
authors.initials: FB
authors.lastname: Calmasini
authors.forename: Ana Paula C
authors.initials: AP
authors.lastname: Davel
authors.forename: Fabíola Z
authors.initials: FZ
authors.lastname: Mónica
authors.forename: Gilberto
authors.initials: G
authors.lastname: De Nucci
authors.forename: Edson
authors.initials: E
authors.lastname: Antunes
mesh_terms: D000818:Animals; D001565:Benzoates / Q000008:administration & dosage / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000008:administration & dosage / Q000627:therapeutic use*; D006162:Guanylate Cyclase / Q000378:metabolism*; D006845:Hydrocarbons, Fluorinated / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009126:Muscle Relaxation / Q000187:drug effects; D009129:Muscle Tonus / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009765:Obesity / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D017382:Reactive Oxygen Species / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D000071756:Soluble Guanylyl Cyclase; D014521:Urethra / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D053201:Urinary Bladder, Overactive / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control
chemical_list: C528797:4-(((4-carboxybutyl) (2- (5-fluoro-2-((4'-(trifluoromethyl) biphenyl-4-yl)methoxy)phenyl)ethyl) amino)methyl)benzoic acid; D001565:Benzoates; D001713:Biphenyl Compounds; D020536:Enzyme Activators; D006845:Hydrocarbons, Fluorinated; D017382:Reactive Oxygen Species; D018160:Receptors, Cytoplasmic and Nuclear; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase