title: Cytokine-induced iNOS and ERK1/2 inhibit adenylyl cyclase type 5/6 activity and stimulate phosphodiesterase 4D5 activity in intestinal longitudinal smooth muscle.
abstract: This study identified a distinctive pattern of expression and activity of adenylyl cyclase (AC) and phosphodiesterase (PDE) isoforms in mouse colonic longitudinal smooth muscle cells and determined the changes in their expression and/or activity in response to proinflammatory cytokines (IL-1β and TNF-α) in vitro and 2,4,6 trinitrobenzene sulphonic acid (TNBS)-induced colonic inflammation in vivo. AC5/6 and PDE4D5, expressed in circular muscle cells, were also expressed in longitudinal smooth muscle. cAMP formation was tightly regulated via feedback phosphorylation of AC5/6 and PDE4D5 by PKA. Inhibition of PKA activity by myristoylated PKI blocked phosphorylation of AC5/6 and PDE4D5 and enhanced cAMP formation. TNBS treatment in vivo and IL-1β and TNF-α in vitro induced inducible nitric oxide synthase (iNOS) expression, stimulated ERK1/2 activity, caused iNOS-mediated S-nitrosylation and inhibition of AC5/6, and induced phosphorylation of PDE4D5 and stimulated its activity. The resultant decrease in AC5/6 activity and increase in PDE4D5 activity decreased cAMP formation and smooth muscle relaxation. S-nitrosylation and inhibition of AC5/6 activity were reversed by the iNOS inhibitor 1400W, whereas phosphorylation and activation of PDE4D5 were reversed by the phosphatidylinositol 3-kinase inhibitor LY294002 and the ERK1/2 inhibitor PD98059. The effects of IL-1β or TNF-α on forskolin-stimulated cAMP formation and smooth muscle relaxation reflected inhibition of AC5/6 activity and activation of PDE4D5 and were partly reversed by 1400W or PD98059 and completely reversed by a combination of the two inhibitors. The changes in the cAMP/PKA signaling and smooth muscle relaxation contribute to colonic dysmotility during inflammation.
authors.affiliation: Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and.
authors.forename: Sunila
authors.initials: S
authors.lastname: Mahavadi
authors.affiliation: Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and.
authors.forename: Ancy D
authors.initials: AD
authors.lastname: Nalli
authors.affiliation: Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and.
authors.forename: Divya P
authors.initials: DP
authors.lastname: Kumar
authors.affiliation: Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and.
authors.forename: John F
authors.initials: JF
authors.lastname: Kuemmerle
authors.affiliation: Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and.
authors.forename: John R
authors.initials: JR
authors.lastname: Grider
authors.affiliation: Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and skarnam@vcu.edu.
authors.forename: Karnam S
authors.initials: KS
authors.lastname: Murthy
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D003092:Colitis / Q000139:chemically induced / Q000201:enzymology* / Q000276:immunology / Q000503:physiopathology; D003106:Colon / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology / Q000503:physiopathology; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4 / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D004195:Disease Models, Animal; D015536:Down-Regulation; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects; D018836:Inflammation Mediators / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009126:Muscle Relaxation; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology* / Q000276:immunology / Q000503:physiopathology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010766:Phosphorylation; D015398:Signal Transduction; D014302:Trinitrobenzenesulfonic Acid; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D016207:Cytokines; D004791:Enzyme Inhibitors; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha; D014302:Trinitrobenzenesulfonic Acid; D000242:Cyclic AMP; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D017868:Cyclic AMP-Dependent Protein Kinases; C535148:Mapk1 protein, mouse; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C531980:PDE4D protein, mouse; D000262:Adenylyl Cyclases; C121100:adenylyl cyclase 6; C419510:adenylyl cyclase type V
keywords: S-nitrosylation; inflammation; muscle relaxation; phosphodiesterases; protein kinase A