Author(s)

Bronislaw L. Slomiany, Amalia Slomiany

Research Center, Rutgers School of Dental Medicine, Rutgers, The State University of New Jersey, Newark, NJ, USA.

Matrix metalloproteinase-9 (MMP-9) is a highly glycosylated endopeptidase implicated in a wide rage of oral mucosal inflammatory and neoplastic diseases, including chronic periodontitis, a persistent mucosal inflammation attributed primarily to infection by oral anaerobe, P. gingivalis. In this study, we explored the role of Rac1 and mitogen-activated protein kinases (MAPKs) in the processes of MMP-9 release in sublingual salivary gland cells exposed to P. gingivalis key endotoxin, cell wall lipopolysaccharide (LPS). We demonstrate that the LPS-elicited induction in the acinar cell MMP-9 release is associated with MAPK, ERK and p38 activation, and occurs with the involvement of Rac1 and cytosolic phospholipase A₂ (cPLA₂). Further, we reveal that the LPS-induced MMP-9 release involves ERK-mediated phosphorylation of cPLA₂ on Ser⁵⁰⁵ that is essential for its membrane translocation with Rac1, and that this process requires p38 activation. Moreover, we show that phosphorylation and membrane localization of p38 with Rac1-GTP play a pivotal role in cPLA₂-dependent induction in MMP-9 release. Thus collectively, our findings infer that P. gingivalis LPS-induced up-regulation in the acinar cell MMP-9 release requires ERK-dependent recruitment of cPLA₂ to the membrane localized Rac1/p38 complex.

P. gingivalis LPS, Oral Mucosa, Rac1, p38, ERK, cPLA₂ Activation MMP-9 Release

Slomiany, B. and Slomiany, A. (2016) Role of Rac1/p38 and ERK-Dependent Cytosolic Phospholipase A₂ Activation in Porphyromonas gingivalis-Evoked Induction in Matrix Metalloproteinase-9 (MMP-9) Release by Salivary Gland Cells. Journal of Biosciences and Medicines, 4, 68-79. doi: 10.4236/jbm.2016.44010.