title: Cytokine-induced S-nitrosylation of soluble guanylyl cyclase and expression of phosphodiesterase 1A contribute to dysfunction of longitudinal smooth muscle relaxation.
abstract: The effect of proinflammatory cytokines on the expression and activity of soluble guanylyl cyclase (sGC) and cGMP-phosphodiesterases (PDEs) was determined in intestinal longitudinal smooth muscle. In control muscle cells, cGMP levels are regulated via activation of sGC and PDE5; the activity of the latter is regulated via feedback phosphorylation by cGMP-dependent protein kinase. In muscle cells isolated from muscle strips cultured with interleukin-1β (IL-1β) or tumor necrosis factor α (TNF-α) or obtained from the colon of TNBS (2,4,6-trinitrobenzene sulfonic acid)-treated mice, expression of inducible nitric oxide synthase (iNOS) was induced and sGC was S-nitrosylated, resulting in attenuation of nitric oxide (NO)-induced sGC activity and cGMP formation. The effect of cytokines on sGC S-nitrosylation and activity was blocked by the iNOS inhibitor 1400W [N-([3-(aminomethyl)phenyl]methyl)ethanimidamide dihydrochloride]. The effect of cytokines on cGMP levels measured in the absence of IBMX (3-isobutyl-1-methylxanthine), however, was partly reversed by 1400W or PDE1 inhibitor vinpocetine and completely reversed by a combination of 1400W and vinpocetine. Expression of PDE1A was induced and was accompanied by an increase in PDE1A activity in muscle cells isolated from muscle strips cultured with IL-1β or TNF-α or obtained from the colon of TNBS-treated mice; the effect of cytokines on PDE1 expression and activity was blocked by MG132 (benzyl N-[(2S)-4-methyl-1-[[(2S)-4-methyl-1-[[(2S)-4-methyl-1-oxopentan-2-yl]amino]-1-oxopentan-2-yl]amino]-1-oxopentan-2-yl]carbamate), an inhibitor of nuclear factor κB activity. NO-induced muscle relaxation was inhibited in longitudinal muscle cells isolated from muscle strips cultured with IL-1β or TNF-α or obtained from the colon of TNBS-treated mice, and this inhibition was completely reversed by the combination of both 1400W and vinpocetine. Inhibition of smooth muscle relaxation during inflammation reflects the combined effects of decreased sGC activity via S-nitrosylation and increased cGMP hydrolysis via PDE1 expression.
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Senthilkumar
authors.initials: S
authors.lastname: Rajagopal
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Ancy D
authors.initials: AD
authors.lastname: Nalli
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Divya P
authors.initials: DP
authors.lastname: Kumar
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Sayak
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: Sunila
authors.initials: S
authors.lastname: Mahavadi
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia.
authors.forename: John R
authors.initials: JR
authors.lastname: Grider
authors.affiliation: Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia skarnam@vcu.edu.
authors.forename: Karnam S
authors.initials: KS
authors.lastname: Murthy
mesh_terms: D000818:Animals; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1 / Q000096:biosynthesis*; D016207:Cytokines / Q000633:toxicity; D015971:Gene Expression Regulation, Enzymologic; D006162:Guanylate Cyclase / Q000096:biosynthesis*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology*; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis*; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis*; D000071756:Soluble Guanylyl Cyclase
chemical_list: D016207:Cytokines; D018160:Receptors, Cytoplasmic and Nuclear; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D054677:Cyclic Nucleotide Phosphodiesterases, Type 1; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase