title: Vascular cell adhesion molecule 1 (VCAM-1) activation of endothelial cell matrix metalloproteinases: role of reactive oxygen species.
abstract: Lymphocytes bound at endothelial cell junctions extravasate within minutes. Lymphocyte-endothelial cell binding is mediated by receptors such as vascular cell adhesion molecule 1 (VCAM-1). VCAM-1 activates endothelial cell nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in minutes, and this activity is required for VCAM-1-dependent lymphocyte migration. In this report, we examined mechanisms for activation of matrix metalloproteinases (MMPs) during VCAM-1-dependent lymphocyte migration. Lymphocyte binding to VCAM-1 rapidly activated endothelial cell-associated MMPs. Furthermore, inhibition of MMPs on the endothelial cells but not on the lymphocytes blocked VCAM-1-dependent lymphocyte migration across endothelial cells. The activation of endothelial cell MMPs required VCAM-1-stimulated endothelial cell NADPH oxidase activity as determined by scavenging of reactive oxygen species (ROS) and by pharmacologic or antisense inhibition of NADPH oxidase. Exogenous addition of 1 microM H(2)O(2), the level of H(2)O(2) generated by VCAM-1-stimulated endothelial cells, rapidly activated endothelial cell-associated MMPs. In contrast, activation of lymphocyte-associated MMPs was delayed by hours after binding to VCAM-1, and this activation was blocked by inhibition of endothelial cell ROS generation. There was also a delay in H(2)O(2)-induced decrease in lymphocyte-associated tissue inhibitors of metalloproteinases (TIMPs), resulting in an increase in MMP/TIMP ratio. In summary, this is the first report of a mechanism for ROS function in VCAM-1 activation of endothelial cell MMPs during VCAM-1-dependent lymphocyte migration.
authors.affiliation: Department of Pathology and Laboratory Medicine, PO Box 670529, University of Cincinnati, Cincinnati, OH 45267-0529, USA.
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Deem
authors.forename: Joan M
authors.initials: JM
authors.lastname: Cook-Mills
mesh_terms: D000818:Animals; D002465:Cell Movement; D002478:Cells, Cultured; D045303:Cytochromes b / Q000235:genetics / Q000378:metabolism; D042783:Endothelial Cells / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D008562:Membrane Glycoproteins; D051379:Mice; D008807:Mice, Inbred BALB C; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D008562:Membrane Glycoproteins; D017382:Reactive Oxygen Species; D019010:Vascular Cell Adhesion Molecule-1; D045303:Cytochromes b; D006861:Hydrogen Peroxide; C488842:Cybb protein, mouse; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9