Slomiany B L, Slomiany A
Research Center, Rutgers School of Dental Medicine, Rutgers, The State University of New Jersey, 110 Bergen Street, PO Box 1709, Newark, NJ, 07103-2400, USA.
Inflammopharmacology. 2016 Jun;24(2-3):119-26. doi: 10.1007/s10787-016-0267-2. Epub 2016 May 21.
Matrix metalloproteinas-9 (MMP-9) is a glycosylated endopeptidase associated with host reaction to microbial endotoxins and also characterizes gastric mucosal inflammatory response to H. pylori infection. Here, we report on the factors involved in gastric mucosal MMP-9 secretion in response to H. pylori LPS, and the effect of hormone, ghrelin. We show that both the LPS-elicited induction in MMP-9 secretion and also the modulatory influence of ghrelin occur at the level of MMP-9 processing between the endoplasmic reticulum (ER) and Golgi. Further, we demonstrate that the LPS effect is associated with up-regulation in the activation of Arf1, a small GTPase of the ADP-ribosylation factor family, and the recruitment and phosphorylation of protein kinase D2 (PKD2), involved in the secretory cargo processing in the Golgi. Moreover, we reveal that the LPS-induced up-regulation in MMP-9 secretion is reflected in a marked increase in PKCδ-mediated PKD2 phosphorylation on Ser, while the modulatory effect of ghrelin is manifested by the SFK-PTKs-dependent phosphorylation of PKD2 on Tyr. Thus, our findings demonstrate the role of Arf1/PKD2 in mediation of H. pylori LPS-induced up-regulation in gastric mucosal MMP-9 secretion and suggest the modulatory mechanism of ghrelin action.
基质金属蛋白酶-9(MMP-9)是一种糖基化的内肽酶,与宿主对微生物内毒素的反应相关,也是胃黏膜对幽门螺杆菌感染炎症反应的特征。在此,我们报告了幽门螺杆菌脂多糖(LPS)刺激下胃黏膜MMP-9分泌所涉及的因素以及激素胃饥饿素的作用。我们发现,LPS诱导的MMP-9分泌增加以及胃饥饿素的调节作用均发生在内质网(ER)和高尔基体之间MMP-9加工水平上。此外,我们证明LPS效应与ADP核糖基化因子家族的小GTP酶Arf1激活上调以及高尔基体中参与分泌货物加工的蛋白激酶D2(PKD2)的募集和磷酸化有关。而且,我们揭示LPS诱导的MMP-9分泌上调表现为蛋白激酶Cδ(PKCδ)介导的PKD2丝氨酸磷酸化显著增加,而胃饥饿素的调节作用则表现为Src家族蛋白酪氨酸激酶(SFK-PTKs)依赖的PKD2酪氨酸磷酸化。因此,我们的研究结果证明了Arf1/PKD2在介导幽门螺杆菌LPS诱导的胃黏膜MMP-9分泌上调中的作用,并提示了胃饥饿素作用的调节机制。