Author(s)

Bronislaw L. Slomiany, Amalia Slomiany

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Disturbances in nitric oxide synthase (NOS) system and the excessive prostaglandin (PGE₂) generation are well-recognized features of oral mucosal inflammatory responses to periodontopathic bacterium, P. gingivalis. Employing rat sublingual gland acinar cells, we show that P. gingivalis LPS-induced up-regulation in PGE₂ generation and the enhancement in inducible (i) iNOS activity was associated with COX-2 activation through S-nitrosylation, and accompanied by the suppression in cSrc activity and the impairment in constitutive (c) cNOS phosphorylation. Further, we demonstrate that the countering effect of peptide hormone, ghrelin, on the LPS-induced changes was reflected in the increased cNOS activation through phosphorylation, repression in iNOS induction, and the reduction in PGE₂ generation associated with the loss of COX-2 protein S-nitrosylation. Moreover, the effect of ghrelin on cNOS phosphorylation and the LPS-induced COX-2 S-nitrosylation was susceptible to the blockage by cSrc inhibition. Our findings suggest that P. gingivalis-induced up-regulation in iNOS leads to COX-2 S-nitrosylation and up-regulation in PGE₂ generation, and that the countering effect of ghrelin is mediated through Src-dependent cNOS activation that is obligatory for the maintenance of iNOS gene suppression.

Salivary Gland; P. gingivalis; iNOS Induction; COX-2 Activation; S-nitrosylation; Ghrelin; cNOS Phosphorylation

Slomiany, B. and Slomiany, A. (2011) Cyclooxygenase-2 S-nitrosylation in salivary gland acinar cell inflammatory responses to Porphyromonas gingivalis: modulatory effect of ghrelin. Advances in Bioscience and Biotechnology, 2, 434-442. doi: 10.4236/abb.2011.26064.