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

J Pharmacol Exp Ther. 2014 Apr;349(1):2-9. doi: 10.1124/jpet.113.211029. Epub 2014 Jan 13.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzoates / administration & dosage
  • Benzoates / therapeutic use*
  • Biphenyl Compounds / administration & dosage
  • Biphenyl Compounds / therapeutic use*
  • Dose-Response Relationship, Drug
  • Enzyme Activation
  • Enzyme Activators / administration & dosage
  • Enzyme Activators / therapeutic use*
  • Guanylate Cyclase / metabolism*
  • Hydrocarbons, Fluorinated / administration & dosage
  • Hydrocarbons, Fluorinated / therapeutic use*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Muscle Relaxation / drug effects
  • Muscle Tonus / drug effects
  • Muscle, Smooth / drug effects
  • Muscle, Smooth / enzymology
  • Muscle, Smooth / metabolism
  • Nitric Oxide / metabolism*
  • Obesity / complications
  • Obesity / drug therapy*
  • Obesity / enzymology
  • Obesity / physiopathology
  • Reactive Oxygen Species / metabolism
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Soluble Guanylyl Cyclase
  • Urethra / drug effects*
  • Urethra / enzymology
  • Urethra / metabolism
  • Urinary Bladder, Overactive / enzymology
  • Urinary Bladder, Overactive / etiology
  • Urinary Bladder, Overactive / physiopathology
  • Urinary Bladder, Overactive / prevention & control

Substances

  • 4-(((4-carboxybutyl) (2- (5-fluoro-2-((4'-(trifluoromethyl) biphenyl-4-yl)methoxy)phenyl)ethyl) amino)methyl)benzoic acid
  • Benzoates
  • Biphenyl Compounds
  • Enzyme Activators
  • Hydrocarbons, Fluorinated
  • Reactive Oxygen Species
  • Receptors, Cytoplasmic and Nuclear
  • Nitric Oxide
  • Guanylate Cyclase
  • Soluble Guanylyl Cyclase