title: Vascular matrix metalloproteinase-2-dependent cleavage of calcitonin gene-related peptide promotes vasoconstriction.
abstract: Matrix metalloproteinase (MMP)-2 has been historically associated with the process of vascular remodeling through the cleavage of extracellular matrix proteins. However, we recently found that MMP-2 also cleaves the endothelium-derived peptide big endothelin-1, ET-1[1-38] and yields the novel vasoconstrictor ET-1[1-32]. We therefore investigated the effects of MMP-2 inhibitors as potential vasodilators. MMP inhibition with ortho-phenanthroline (0.3 to 30 micromol/L) induced vasorelaxation of isolated rat mesenteric arteries (maximum of relaxation=74.5+/-27.6% at 30 micromol/L). However, phosphoramidon (0.3 to 30 micromol/L), which inhibits some metalloenzymes, but not MMP-2, did not dilate the arteries. Selective inhibition of endogenous MMP-2 with the novel tissue-permeable cyclic peptide CTTHWGFTLC (CTT, 10 micromol/L) also caused vasorelaxation (by 85+/-6%), whereas STTHWGFTLS (10 micromol/L), an inactive CTT analogue, did not dilate the arteries. Interestingly, the vasorelaxation that results from MMP-2 inhibition was endothelium-independent. Thus, we examined whether MMP-2 acted on peptides derived from the smooth muscle or the perivascular nerves. Recombinant human MMP-2 cleaved calcitonin gene-related peptide (CGRP) specifically at the Gly(14)-Leu(15) peptide bond and reduced the vasodilatory potency of CGRP by 20-fold. Inhibition of MMP-2 increased the amount of intact CGRP in arteries and enhanced vasorelaxation induced by anandamide, which stimulates CGRP release. Vasorelaxation in response to MMP-2 inhibition was abolished by CGRP[8-37], a selective CGRP receptor antagonist, and by capsaicin, which depletes arterial perivascular nerves of CGRP. We conclude that vascular MMP-2 cleaves endogenous CGRP and promotes vasoconstriction. These data suggest a novel mechanism of regulating the vasoactive and, possibly, the neurohormonal actions of CGRP and establish MMP-2 as a modulator of vascular function.
authors.affiliation: Perinatal Research Centre, Departments of Obstetrics/Gynaecology and Physiology, University of Alberta, Edmonton, Alberta, Canada. cf2@ualberta.ca
authors.forename: C
authors.initials: C
authors.lastname: Fernandez-Patron
authors.forename: K G
authors.initials: KG
authors.lastname: Stewart
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: E
authors.initials: E
authors.lastname: Koivunen
authors.forename: M W
authors.initials: MW
authors.lastname: Radomski
authors.forename: S T
authors.initials: ST
authors.lastname: Davidge
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D015740:Calcitonin Gene-Related Peptide / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D000077221:Calcitonin Gene-Related Peptide Receptor Antagonists; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002211:Capsaicin / Q000009:adverse effects / Q000494:pharmacology; D063388:Endocannabinoids; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D006020:Glycopeptides / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism* / Q000494:pharmacology; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism / Q000494:pharmacology; D061965:Matrix Metalloproteinase Inhibitors; D008638:Mesenteric Arteries / Q000187:drug effects / Q000378:metabolism; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D010456:Peptides, Cyclic / Q000494:pharmacology; D010618:Phenanthrolines / Q000494:pharmacology; D053284:Polyunsaturated Alkamides; D051381:Rats; D017207:Rats, Sprague-Dawley; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001095:Arachidonic Acids; C415426:CTTHWGFTLC peptide; D000077221:Calcitonin Gene-Related Peptide Receptor Antagonists; D002121:Calcium Channel Blockers; D063388:Endocannabinoids; D006020:Glycopeptides; D061965:Matrix Metalloproteinase Inhibitors; D010456:Peptides, Cyclic; D010618:Phenanthrolines; D053284:Polyunsaturated Alkamides; D014665:Vasodilator Agents; C001635:ferroin; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; C008890:phosphoramidon; C078814:anandamide