title: Vascular matrix metalloproteinase-2 cleaves big endothelin-1 yielding a novel vasoconstrictor.
abstract: Matrix metalloproteinase-2 (MMP-2, gelatinase A) and its tissue inhibitor (TIMP-2) are mainly known for their roles in the (patho)physiological remodeling of the vasculature, angiogenesis, tissue repair, tumor invasion, inflammation, and atherosclerotic plaque rupture. A mechanism of action of MMP-2 is the proteolytic breakdown of specific extracellular matrix proteins. The amino acid sequences in interstitial collagen (Gly-Leu/Ile) and laminin-5 (Ala-Leu) that are cleaved by MMP-2 are homologous to a region (Gly(32)-Leu(33)) within human big endothelin-1[1 to 38] (big ET-1). Big ET-1 requires cleavage to an active form to produce vasoconstriction. We tested the hypothesis that vascular MMP-2 can cleave big ET-1, thus generating a vasoconstrictor peptide. In perfused rat mesenteric arteries with an intact endothelium, inhibition of vascular MMP-2 with TIMP-2 reduced (by 16.2+/-4.2%) the vasoconstrictor effects of big ET-1 (50 pmol). However, when the endothelium was mechanically removed, TIMP-2 abolished (>90%) the vasoconstriction of big ET-1, and this effect was mimicked by an anti-MMP-2 antibody. Incubation of big ET-1 with recombinant human MMP-2 resulted in the specific cleavage of the Gly(32)-Leu(33) bond of big ET-1. Moreover, the resultant peptide ET-1[1 to 32] exerted greater vasoconstrictor effects than big ET-1. We conclude that vascular MMP-2 contributes to the vasoconstrictor effects of big ET-1 by cleaving big ET-1 to yield a novel and potent vasoconstrictor, ET-1[1 to 32]. These data implicate, for the first time, the endogenous MMP-2/TIMP-2 system in the regulation of vascular reactivity.
authors.affiliation: Perinatal Research Centre (C.F-P., S.T.D.), Departments of Obstetrics/Gynaecology and Physiology, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Fernandez-Patron
authors.forename: M W
authors.initials: MW
authors.lastname: Radomski
authors.forename: S T
authors.initials: ST
authors.lastname: Davidge
mesh_terms: D000818:Animals; D019332:Endothelin-1; D016232:Endothelins / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D008638:Mesenteric Arteries / Q000201:enzymology; D010452:Peptide Biosynthesis / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D011498:Protein Precursors / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D014662:Vasoconstrictor Agents / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D019332:Endothelin-1; D016232:Endothelins; D010446:Peptide Fragments; D011498:Protein Precursors; D011994:Recombinant Proteins; D014662:Vasoconstrictor Agents; D020778:Matrix Metalloproteinase 2