Health  Vol.2 No.12 , December 2010
Role of ghrelin in modulation of s-nitrosylation-Dependent akt inactivation induced in salivary gland acinar cells by porphyromonas gingivalis
ABSTRACT
Ghrelin, a peptide hormone, newly identified in oral mucosal tissue, has emerged re-cently as a principal modulator of the in-flammatory responses to bacterial infection through the regulation of nitric oxide syn-thase system. In this study, using rat sub-lingual salivary gland acinar cells, we report that lipopolysaccharide (LPS) of periodon-topathic bacterium, P. gingivalis- induced enhancement in the activity of inducible ni-tric oxide synthase (iNOS) was associated with the suppression in Akt kinase activity and the impairment in constitutive (c) cNOS phosphorylation. Further, we show that the detrimental effect of the LPS on Akt activa-tion, manifested in the kinase protein S-nitrosylation and a decrease in its phos-phorylation at Ser473, was susceptible to suppression by iNOS inhibitor, 1400W. Moreover, we demonstrate that a peptide hormone, ghrelin, countered the LPS- induced changes in Akt activity and NOS system. This effect of ghrelin was reflected in the decreased in Akt S-nitrosylation and the increase in its phosphorylation at Ser473, as well as cNOS activation through phos-phorylation. Our findings suggest that P. gingivalis-induced up-regulation in iNOS leads to Akt kinase inactivation through S-nitrosylation that impacts cNOS activation through phosphorylation. We also show that the countering effect of ghrelin on P. gingivalis-induced disturbances in Akt ac-tivation are manifested in a decrease in the kinase S-nitrosylation and the increase in its phosphorylation.

Cite this paper
nullSlomiany, B. and Slomiany, A. (2010) Role of ghrelin in modulation of s-nitrosylation-Dependent akt inactivation induced in salivary gland acinar cells by porphyromonas gingivalis. Health, 2, 1448-1455. doi: 10.4236/health.2010.212215.
References
[1]   Kojima, M., Hosoda, H., Date, Y., Nakazato, M., Matsuo, H. and Kangawa, K. (1999) Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature, 402, 656-660.

[2]   Kojima, M. and Kangawa, K. (2005) Ghrelin: structure and function. Physiology Reviews, 85, 495-522.

[3]   Groschl, M., Topf, H.G., Bohlender, J., Zenk, J., Klussmann, S., Dotsch, J., Rascher, W. and Rauh, M. (2005) Identification of ghrelin in human saliva: production by the salivary glands and potential role in proliferation of oral keratinocytes. Clinical Chemistry, 51, 997-1006.

[4]   Osawa, H., Nakazato, M., Date, Y., Kita, H., Ohnishi, H., Ueno, H., Shijya, T., Satoh, K., Ishino, Y. and Sugato, K. (2005) Impaired production of gastric ghrelin in chronic gastritis associated with Helicobacter pylori. Journal of Clinical Endocrinology & Metabolism, 90, 10-16.

[5]   Waseem, T., Duxbury, M., Ito, H., Ashley, S.W. and Robinson, M.K. (2008) Exogenous ghrelin modulates release of proinflammatory and anti-inflammatory cytokines in LPS-stimulated macrophages through distinct signaling pathways. Surgery, 143, 334-342.

[6]   Xu, X., Jhun, B.S., Ha, C.H. and Jin, Z.G. (2008) Molecular mechanisms of ghrelin-mediated endothelial nitric-oxide synthase activation. Endocrinology, 149, 4183-4192.

[7]   Slomiany, B.L. and Slomiany, A.(2010) Ghrelin protection against lipopolysaccharide-induced gastric mucosal cell apoptosis involves constitutive nitric oxide synthase-mediated caspase-3 S-nitrosylation. Mediators of Inflammation, Doi:10.1155/2010/280464.

[8]   Slomiany, B.L. and Slomiany, A. (2010) Suppression by ghrelin of Porphyromonas gingivalis-induced constitutive nitric oxide synthase S- nitrosylation and apoptosis in salivary gland acinar cells. Journal of Signal Transduction, Doi:1155/2010/643642.

[9]   Korhonen, R., Lahti, A., Kankaanranta, H. and Moilanen, E. (2005) Nitric oxide production and signaling in inflammation. Current Drug Targets: Inflammation & Allergy, 4, 471-479.

[10]   Cuzzocrea, S. and Salvemini, D. (2007) Molecular mechanisms involved in the reciprocal regulation of cyclooxygenase and nitric oxide synthase enzymes. Kidney International, 71, 290-297.

[11]   Kim, Y.M., Talanian, R.V. and Billiar, T.R. (1997) Nitric oxide inhibits apoptosis by preventing increases in caspase-3-like activity via two distinct mechanisms. Journal of Biological Chemistry, 272, 31138 – 31148.

[12]   Chanvorachote, P., Nimmannit, U., Wang, L., Stehlik, C., Lu, B., Azad, N. and Rojanaskul, Y. (2005) Nitric oxide negatively regulates Fas CD95-induced apoptosis through inhibition of ubiquitin-proteosome-mediated degradation of FLICE inhibitory protein. Journal of Biological Chemistry, 280, 2044-42050.

[13]   Wong, J.M. and Billiair, T.R. (1995) Regulation and function of inducible nitric oxide synthase during sepsis and acute inflammation. Advances in Pharmacology, 34, 155-170.

[14]   Slomiany, B.L., Piotrowski, J. and Slomiany, A. (1998) Induction of caspase-3 and nitric oxide synthase-2 during gastric mucosal inflammatory reaction to Helicobacter pylori lipopolysaccharide. Biochemistry and Molecular Biology International, 46, 1063-1070.

[15]   Haynes, M.P., Li, L., Sinha, D., Russell, K.S., Hisamoto, K., Baron, R., Collinge, M., Sessa, W.C. and Bender, J.R. (2003) Src kinase mediates phopsphtidylinositol 3-kinase /Akt-dependent rapid endothelial nitric-oxide synthase activation by estrogen. Journal of Biological Chemistry, 278, 2118-2123.

[16]   Carvalho-Filho, M.A., Ueno, M., Carvalheira, J.B.C., Velloso, L.A. and Saad, M.J.A. (2006) Targeted disruption of iNOS prevents LPS-induced S- nitrosylation of IRB/IRS-1 and Akt and insulin resistance in muscle of mice. American Journal of Physiology Endocrinology and Metabolism, 291, E476-482.

[17]   Hanada, M., Feng, J. and Hemmings, B.A. (2004) Structure, regulation and function of PKB/AKT – a major therapeutic target. Biochimica et Biophysica Acta-Proteins & Proteomics, 1697, 3-16.

[18]   Lodeiro, M., Theoderopoulous, M., Pardo, M., Casanueva, F.F. and Camina, J.P. (2009) c-Src regulates Akt signaling in response to ghrelin via ?-arrestin signaling-independent and –dependent mechanisms. PLoS ONE, 4(3): e4686. doi: 10.1371.

[19]   Yang, J., Cron, P., Thompson, V., Good, V.M., Hess, D., Hemmings, B.A. and Bradford, D. (2002) Molecular mechanisms for the regulation of protein kinase B/Akt by hydrophobic motif phosphorylation. Molecular Cell 9, 1227-1240.

[20]   Yasukawa, T., Tokunaga, E., Ota, H., Sugita, H., Martyn, J.A.J. and Kaneki, M. (2005) S-nitrosylation-dependent inactivation of Akt/protein kinase B in insulin resistance. Journal of Biological Chemistry, 280, 7511 -7518.

[21]   Carvalho-Filho, M.A., Ueno, M., Hirabara, S.M., Seabra, A.B., Carvalheira, J.B.C., de Oliveira, M.G., Vellosa, L.A., Curi, R. and Saad, M.J.A. (2005) S-nirosation of the insulin receptor, insulin receptor substrate 1, and protein kinase B/Akt. Diabetes, 54, 959-967.

[22]   Slomiany, B.L. and Slomiany, A. (2010) Mechanism of cytosolic phospholipase A2 activation in ghrelin protection of salivary gland acinar cell against ethanol cytotoxicity. Advances in Pharmacological Sciences, doi: 10.1155/2010/ 269274.

[23]   Slomiany] B.L. and Slomiany, A. (2003) Activation of peroxisome proliferator-activated receptor g impedes Porphyromonas gingivalis lipopolysaccharide interference with salivary mucin synthesis through phosphatidylinositol 3-kinase/ERK pathway. Journal of Physiology and Pharmacology, 54, 3-15.

[24]   Slomiany, B.L., Murty, V.L.N., Piotrowski, J., Liau, Y.H. and Slomiany, A. (1993) Gycosulfatase activity of P. gingivalis, a bacterium associated with periodontal disease. Biochemistry and Molecular Biology International, 29, 973-980.

[25]   Wagner, D.A., Glogowski, J., Skipper, P.L., Wishnok, J.S. and Tannenbaum, S.R. (1982) Analysis of nitrate, nitrite and [15N]nitrate in biological fluids. Analytical Biochemistry, 126,131-138.

[26]   Jaffrey, S.R., Erdjument-Bromage, H., Ferris, D., Tempst, P. and Snyder, S.H. (2001) Protein S-nitrosylation: a physiological signal for neuronal nitric acid. Nature Cell Biology, 3, 193-197.

[27]   Forrester, M.T., Forrester, M.W. and Stamler, J.S. (2007) Assessment and application of the biotin switch technique for examining protein S-nitrosylation under conditions of pharmacologically induced oxidative stress. Journal of Biological Chemistry, 282, 13977-13983.

[28]   Slomiany, B.L. and Slomiany, A. (2008) Leptin protection of salivary gland acinar cells against ethanol cytotoxicity involves Src kinase-mediated parallel activation of prostaglandin and constitutive nitric oxide synthase pathways. Inflammopharmacology, 16, 76-82.

[29]   Wang, P.L. and Ohura, K. (2001) Porphyromonas gingivalis lipopolysaccharide signaling in gingival fibroblasts- CD14 and toll-like receptors. Critical Reviews in Oral Biology and Medicine, 13,132-142.

[30]   Wiles, T.J., Dhakal, B.K., Eto, D.S. and Mulvey, M.A. (2008) Inactivation of host Akt/PKB signaling by bacterial pore-forming toxins. Molecular Biology of the Cell, 19, 1427-1438.

[31]   Hattori, Y., Hattori, S. and Kasai, K. (2003) Lipopolysaccharide activates Akt in vascular smooth muscle cells resulting in induction of inducible nitric oxide synthase through nuclear factor-kappa B activation. European Journal of Pharmacology, 481, 153-158.

[32]   Mannick, J.B. (2007) Regulation of apoptosis by protein S-nitrosylation. Amino Acids, 32, 523-526

 
 
Top