title: Angiotensin II induces NF-κB, JNK and p38 MAPK activation in monocytic cells and increases matrix metalloproteinase-9 expression in a PKC- andRho kinase-dependent manner.
abstract: Angiotensin II (ANG II), the main effector of the renin-angiotensin system, is implicated in endothelial permeability, recruitment and activation of the immune cells, and also vascular remodeling through induction of inflammatory genes. Matrix metalloproteinases (MMPs) are considered to be important inflammatory factors. Elucidation of ANG II signaling pathways and of possible cross-talks between their components is essential for the development of efficient inhibitory medications. The current study investigates the inflammatory signaling pathways activated by ANG II in cultures of human monocytic U-937 cells, and the effects of specific pharmacological inhibitors of signaling intermediates on MMP-9 gene (MMP-9) expression and activity. MMP-9 expression was determined by real-time PCR and supernatants were analyzed for MMP-9 activity by ELISA and zymography methods. A multi-target ELISA kit was employed to evaluate IκB, NF-κB, JNK, p38, and STAT3 activation following treatments. Stimulation with ANG II (100 nM) significantly increased MMP-9 expression and activity, and also activated NF-κB, JNK, and p38 by 3.8-, 2.8- and 2.2-fold, respectively (P < 0.01). ANG II-induced MMP-9 expression was significantly reduced by 75 and 67%, respectively, by co-incubation of the cells with a selective inhibitor of protein kinase C (GF109203X, 5 µM) or of rho kinase (Y-27632, 15 µM), but not with inhibitors of phosphoinositide 3-kinase (wortmannin, 200 nM), tyrosine kinases (genistein, 100 µM) or of reactive oxygen species (α-tocopherol, 100 µM). Thus, protein kinase C and Rho kinase are important components of the inflammatory signaling pathways activated by ANG II to increase MMP-9 expression in monocytic cells. Both signaling molecules may constitute potential targets for effective management of inflammation.
authors.affiliation: Department of Laboratory Medical Sciences, Faculty of Paramedicine, Ahvaz Jundishapur University of Medical Sciences, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Yaghooti
authors.forename: M
authors.initials: M
authors.lastname: Firoozrai
authors.forename: S
authors.initials: S
authors.lastname: Fallah
authors.forename: M R
authors.initials: MR
authors.lastname: Khorramizadeh
mesh_terms: D000804:Angiotensin II / Q000494:pharmacology*; D006801:Humans; D007249:Inflammation / Q000201:enzymology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D020298:U937 Cells; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism
chemical_list: D016328:NF-kappa B; D000804:Angiotensin II; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D011493:Protein Kinase C; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9