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 inflammat...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 A<sub>2</sub> (cPLA<sub>2</sub>). Further, we reveal that the LPS-induced MMP-9 release involves ERK-mediated phosphorylation of cPLA<sub>2</sub> on Ser<sup>505</sup> 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 cPLA<sub>2</sub>-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 cPLA<sub>2</sub> to the membrane localized Rac1/p38 complex.展开更多
基金the National Natural Science Foundation of China, No. 30960389, 81060151, 81160236the Joint Foundation of Yunnan Science and Technology Department and Kunming Medical University, No. 2009cd159+1 种基金Yunnan Key New Product Development Projects, No. 2010BC010the Innovation Foundation for Doctors in Kunming Medical University, No. 2011D07~~
文摘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 A<sub>2</sub> (cPLA<sub>2</sub>). Further, we reveal that the LPS-induced MMP-9 release involves ERK-mediated phosphorylation of cPLA<sub>2</sub> on Ser<sup>505</sup> 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 cPLA<sub>2</sub>-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 cPLA<sub>2</sub> to the membrane localized Rac1/p38 complex.
