title: Degradation of extracellular matrix by peroxynitrite/peroxynitrous acid.
abstract: The extracellular matrix (ECM) provides strength and elasticity to tissues and plays a key role in regulating cell behavior; damage to this material is believed to be a major factor in many inflammatory diseases. Peroxynitrite/peroxynitrous acid, which is generated at elevated levels at sites of inflammation, is believed to play a role in ECM damage; however, the mechanisms involved are poorly understood. Here we examined the reactions of bolus peroxynitrite, and that generated in a time-dependent manner by SIN-1 decomposition, with ECM isolated from a vascular smooth muscle cell line and porcine thoracic aorta. Bolus peroxynitrite caused the release of ECM glycosaminoglycans and proteins, the formation of 3-nitroTyr, and the detection of ECM-derived radicals (by immuno-spin trapping) in a concentration-dependent manner. Release and nitration of ECM components were modulated by the local pH and bicarbonate. SIN-1 caused the release of glycosaminoglycan, but not protein, from vascular smooth muscle cell-derived ECM in a concentration-, time-, and pH-dependent manner. The data presented here suggest that peroxynitrite-mediated damage to ECM occurs via a radical-mediated pathway. These reactions may contribute to ECM damage at sites of inflammation and play a role in disease progression, including rupture of atherosclerotic lesions.
authors.affiliation: The Heart Research Institute, 114 Pyrmont Bridge Road, Camperdown, NSW 2050, Australia.
authors.forename: Eleanor C
authors.initials: EC
authors.lastname: Kennett
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davies
mesh_terms: D000818:Animals; D001639:Bicarbonates / Q000378:metabolism; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D013552:Swine; D014443:Tyrosine / Q000378:metabolism
chemical_list: D001639:Bicarbonates; D030421:Peroxynitrous Acid; D014443:Tyrosine; C002385:linsidomine; D008981:Molsidomine