Excessive nitric oxide generation, caused by the disturbances in nitric oxide synthase (NOS) isozyme system,plays a key role in defining the extent of gastric mucosal inflammatory response to H. pylori infection. Here, we report that H. pylori LPS-induced enhancement in gastric mucosal inducible (i) iNOS expression and the impairment in constitutive (c) cNOS activity was associated with up-regulation in the inhibitory kB kinase-β (IKK?β) activation through phosphorylation, rise in IκB-α degradation, and the increase in the transcriptional factor, NF-κB, nuclear translocation. Further, we show that the countering effect of peptide hormone, ghrelin, on the LPS-induced disturbances in NOS isozyme system was reflected in the increase in Src/Akt-dependent cNOS activation through phosphorylation and the suppression of IKK-β activity through cNOSmediated IKK-β protein S-nitrosylation. As a consequence, ghrelin exerted the inhibitory effect on the LPS-induced rise in IκB-α degradation and NF-κB nuclear translocation, thus leading to iNOS gene suppression and the repression of iNOS induction. These results point to a central role of cNOS activation in controlling the signaling pathways of theLPS-triggered iNOS gene induction. Moreover, our findings suggest a molecular mechanism by which ghrelin suppresses the gastric mucosal proinflammatory consequences of H. pylori infection.
Cite this paper
B. Slomiany and A. Slomiany, "Ghrelin Suppression of Helicobacter pylori-Induced Gastric Mucosal Expression of iNOS is Mediated through the Inhibition of IKK-β Activation by cNOS-Dependent S-Nitrosylation," CellBio, Vol. 1 No. 1, 2011, pp. 1-10. doi: 10.4236/ojcb.2011.11001.
 M. Stolte and S. Edit, “Helicobacter Pylori and Evolution of Gastritis,” Scandinavian Journal of Gastro-enterology, Vol. 31, No. 214, 1996, pp. 13-16.
 J. Piotrowski, E. Piotrowski, D. Skrodzka, A. Slomiany and B. L. Slomiany, “Induction of Acute Gastritis and Epithelial Cell Apoptosis by Helicobacter pylori lipopolysaccharide,” Scandinavian Journal of Gastroenterology, Vol. 32, 1997, pp. 203-211.
 W. A. de Boer, “Helicobacter Pylori Infection: Focus on a ‘Search-And-Treat’ Strategy for Ulcer Disease,” Scandinavian Journal of Gastroenterology, Vol. 35, No. 232, 2000, pp. 4-9.
 F. Fu, K. S. Ramanujan, A. Wong, et al., “Increased Expression and Cellular Localization of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 in Helicobacter pylori Gastritis,” Gastroenterology, Vol. 116, No. 6, 1999 pp. 1319-1329. doi:10.1016/S0016-5085(99)70496-8
 B. L. Slomiany, J. Piotrowski and A. Slomiany, “Gastric Mucosal Inflammatory Responses to Helicobacter pylori lipopolysaccharide: Down-Regulation of Nitric Oxide Synthase-2 and Caspase-3 by Sulglycotide,” Biochemicaland Biophysical Research Communications, Vol. 261, No. 1, 1999, pp. 15-20. doi:10.1006/bbrc.1999.1003
 R. A. Gupta, D. B. Polk, U. Krishna, et al., “Activation of Peroxisome Proliferator-Activated Receptor g Suppresses Nuclear Factor kB-Mediated Apoptosis Induced by Helicobacter pylori in Gastric Epithelial Cells,” Journal of Biological Chemistry, Vol. 276, No. 33, 2001, pp. 31059-31066. doi:10.1074/jbc.M104141200
 G. Reider, J. A. Hofmann, R. A. Hatz, M. Stolte and G. A. Enders, “Up-Regulation of Inducible Nitric Oxide Synthase in Helicobacter pylori-Associated Gastritis may Represent an Increased Risk Factor to Develop Gastric Carcinoma of the Intestinal Type,” International Journal of Medical Microbiology, Vol. 293, No. 6, 2003, pp. 403-412. doi:10.1078/1438-4221-00280
 S. Cuzzocrea and D. Salvemini, “Molecular Mechanisms Involved in the Reciprocal Regulation of Cyclooxy-Genase and Nitric Oxide Synthase Enzymes,” Kidney International, Vol. 71, No. 4, 2007, pp. 290-297.
 B. L. Slomiany and A. Slomiany, “Helicobacter pylori Induces Disturbances in Gastric Mucosal Akt Activation through Inducible Nitric Oxide Syn-Thase-Dependent S-Nitrosylation: Effect of Ghrelin,” ISRN Gastroenterology, Article No. 308727, 2010. doi:10.5402/2011
 S. Brandt, T. Kwok, R. Harting, W. Konig and S. Backert, “NF-κB Activation and Potentiation of Proinflammatory Responses by the Helicobacter pylori CagA Protein,” Proceedings of the National Academy of Sciences of the USA, Vol. 102, No. 26, 2005, pp. 9300-9305.
 R. L. Ferrero, P. Ave, D. Nadiaye, et al., “NF-kB Activation During Acute Helicobacter pylori Infection in Mice,” Infection and Immunity, Vol. 76, No. 2, 2008, pp. 551-561. doi:10.1128/IAI.01107-07
 S. Backert and M. Neumann, “What a Disorder: ProinFlammatory Signaling Pathways Induced by Helicobacter pylori,” Trends in Microbiology, Vol. 18, No. 11, 2010, pp. 479-486. doi:10.1016/j.tim.2010.08.003
 K. W. Kang, S. Y. Choi, M. K. Cho, C. C. Lee and S. G. Kim, “Thrombin Induces Nitric-Oxide Synthase via Ga12/13-Coupled Protein Kinase C-Dependent I-kBa Phos-phorylation and JNK-Mediated I-kBa Degradation,” Journal of Biological Chemistry, Vol. 278, 2003, pp. 17368-17378. doi:10.1074/jbc.M300471200
 K. Singh, R. Chaturvedi, M. Asim, D. P. Barry, N. D. Lewis, M. P. Vitek and K. T. Wilson, “The Apolipoprotein E-Mimetic Peptide COG112 Inhibits the Inflammatory Response to Citrobacter rodentium in Colonic Epithelial Cells by Preventing NF-kB Activation,” Journal of Biological Chemistry, Vol. 283, No. 24, 2008, pp. 16752-16761. doi:10.1074/jbc.M710530200
 H. Tanaka, N. Fujita and T. Tsuruo, “3-Phospho-Inositide-Dependent Protein Kinase-1-Mediated IκB Kinase β (IKKB) Phosphorylation Activates NF-κB Signaling,” Journal of Biological Chemistry, Vol. 280, No. 49, 2005, pp. 40965-40973. doi:10.1074/jbc.M506235200
 J. L. Kang, H. W. Lee, H. J. Kim, H. S. Lee, V. Castranova, C. M. Lim and Y. Koh, “Inhibition of Src Tyrosine Kinase β Suppresses Activation of Nuclear Factor-kB, and Serine and Tyrosine Phosphorylation of IκB-a in Lipopolysaccharide-Stimulated Raw 264.7 Macrophages,” Journal of Toxicology and Environmental Health, Part A, Vol. 68, 2005, pp. 1643-1662.
 S. C. Gupta, S. Prasad, S. Reuter, et al., “Modification of Cysteine 179 of IkBa Kinase by Nimbolide Leads to Down-Regulation of NF-kB-Regulated Cell Survival and Proliferative Proteins and Sensitization of Tumor Cells to Chemotherapeutic Agents, Journal of Biological Chemistry, Vol. 285, No. 46, 2010, pp. 35406-35417.
 H. Nakano, M. Shinodo, S. Sakon, S. Nishinaka, M. Mihara, H. Yagita and K. Okumura, “Differential Regulation of IκB Kinase a and b by Two Upstreamkinases, NF-κB-Inducing Kinase and Mitogen-Activated Protein Kinase/ERK Kinase-1,” Proceedings of the National Academy of Sciences of the USA, Vol. 95, 1998, pp. 3537-3542. doi:10.1073/pnas.95.7.3537
 S. Gosh and M. Karin, “Missing Pieces in the NF-κB Puzzle,” Cell, Vol. 109, 2002, pp. S81-S96.
 C. Rieke, A. Papendieck, O. Sokolova and M. Naumann, “Helicobacter pylori-Induced Tyrosine Phosphorylation of IKKβ Contributes to NF-κB Activation,” Biological Chemistry, Vol. 392, 2011, pp. 387-393.
 N. L. Reynaert, K. Ckless, S. H. Korn, et al., “Nitric Oxide Represses Inhibitory κB Kinase through S-Nitrosylation,” Proceedings National Academy of Sciences of the USA, Vol. 101, No. 24, 2004, pp. 8945-8950.
 N. D. Perkins, “Integrating Cell-Signalling Path Ways with NF- and IKK Function,” Nature Reviews Molecular Cell Biology, Vol. 8, No. 1, 2007, pp. 49-62.
 M. Kojima, H. Hosoda, Y. Date, M. Nakazato and K. Kangawa, “Ghrelin is a Growth-Hormone-Releasing Acylated Peptide from Stomach,” Nature, Vol. 402, No. 6762, 1999, pp. 656-660. doi:10.1038/45230
 X. Xu, B. S. Jhun, C. H. Ha and Z. G. Jin, “Molecular Mechanisms of Ghrelin-Mediated Endothelial Nitric-Oxide Synthase Activation. Endocrinology, Vol. 149, No. 8, 2008, pp. 4183-4192. doi:10.1210/en.2008-0255
 B. L. Slomiany and A. Slomiany, “Ghrelin Protection against Lipopolysaccharide-Induced Gastric Mucosal Cell Apoptosis Involves Constitutive Nitric Oxide Synthase-Mediated Caspase-3 S-Nitrosylation,” Mediators of Inflammation, 2010. doi:1155/2010/280464
 B. L. Slomiany and A. Slomiany, “Role of Ghrelin-Induced cSrc Activation in Modulation of Gastric Mucosal Inflammatory Responses to Helicobacter pylori,” Inflammopharmacology, Vol. 19, No. 4, 2011, pp. 197-204.
 A. Slomiany and B. L. Slomiany, “Transformations of Phosphatidyl-Inositol Phosphates in the Outer and Inner Nuclear Membrane are Linked to Synthesis and Restitution of Cellular Membranes,” Health, Vol. 3, No. 4, 2011, pp. 187-199. doi:10.4236/health.2011.34035
 S. M. Noha, A. G. Atanasov, D. Schuster, et al., “Discovery of a Novel IKK-b Inhibitor by Ligand-Based Virtual Screening Techniques,” Bioorganic and Medicinal Chemistry Letters, Vol. 21, 2011, pp. 577-583.
 S. R. Jaffrey, H. Erdjument-Bromage, D. Ferris, P. Tempst and S. H. Snyder, “Protein S-Nitrosylation: A Physiological Signal for Neuronal Nitric Acid,” Nature Cell Biology, Vol. 3, No. 2, 2001, pp. 193-197.
 M. T. Forrester, M. W. Foster and J. S. Stamler, “Assessment and Application of the Biotin Switch Technique for Examining Protein S-Nitrosylation under Conditions of Pharmacologically Induced Oxidative Stress,” Journal of Biological Chemistry, Vol. 282, No. 19, 2007, pp. 13977-13983. doi:10.1074/jbc.M609684200
 H. E. Marshall, D. T. Hess and J. S. Stamler, “S-Nitrosylation: Physiological Regulation of NF-κB,” Proceedings of the National Academy of Sciences of the USA, Vol. 101, 2004, pp. 8841-8842. doi:10.1073/pnas.0403034101
 R. Korhonen, A. Lahti, H. Kankaanranta and E. Moilanen, “Nitric Oxide Production and Signaling in Inflammation,” Current Drug Targets: Inflammation and Allergy, Vol. 4, No. 4, 2005, pp. 471-479.
 B. L. Slomiany and A. Slomiany, “Ghrelin Suppression of Helicobacter pylori-Induced S-Nitrosylation-Dependent Gastric Mucosal Akt Inactivation Exerts Modulatory Influence on Gastric Mucin Synthesis,” Inflammopharmacology, Vol. 19, 2011, pp. 89-97.
 P. Lodeiro, M. Theodoropoulou, M. Pardo, F. F. Casa-nueva and J. P. Camina, “C-Src Regulates Akt Signaling in Response to Ghrelin via β-Arrestin Signaling-Independent and -Dependent Mechanism,” PLoS ONE, Vol. 4, No. 3, 2009, p.e4686.