title: Expression of matrix metalloproteinases and their inhibitor TIMP-1 in the rat carotid artery after balloon injury.
abstract: The temporal relationship of matrix metalloproteinases (MMPs) and a specific tissue inhibitor (TIMP-1) has been examined by reverse transcription-polymerase chain reaction and substrate zymography, after balloon catheter angioplasty of the rat carotid artery. The contralateral uninjured carotid artery was used as a comparative control. Of the MMPs examined, only MMP-2 (72-kDa gelatinase) was produced constitutively by normal uninjured arteries. After injury, MMP-2 mRNA levels fell compared with the uninjured arteries; by 24 hours, levels had increased 2-fold. Zymography showed that the inactive form of MMP-2 predominated in uninjured vessels, but after injury, the level of the active form was increased. MMP-9 (92-kDa gelatinase) mRNA levels and activity peaked at 6 hours after injury and were still detectable at 7 days. MMP-3 (stromelysin) expression was detectable at low levels as early as 2 hours after injury and showed an approximate 2-fold increase of expression at 7 days. The presence of the active protein paralleled the mRNA expression. The inhibitor TIMP-1 mRNA was first detected 6 hours after injury and showed a marked peak of expression at 24 hours; however, no expression was detected by 7 days. The presence of a constitutively expressed, low molecular weight caseinolytic enzyme (27 kDa) was observed, and the induction of a caseinolytic enzyme (30 kDa) was noted that was induced as early as 2 hours after injury, peaked at 6 hours, and was barely detectable by 7 days. These results demonstrate that the process of extracellular matrix breakdown by MMPs after balloon catheter-induced injury is controlled by a tightly regulated temporal response by the genes responsible for the production of these enzymes and their inhibitor and by post-translational activation of the proenzymes.
authors.affiliation: Centre for Genetics of Cardiovascular Disorders, University College London Medical School, Rayne Institute, United Kingdom. k.webb@med.ucl.ac.uk
authors.forename: K E
authors.initials: KE
authors.lastname: Webb
authors.forename: A M
authors.initials: AM
authors.lastname: Henney
authors.forename: S
authors.initials: S
authors.lastname: Anglin
authors.forename: S E
authors.initials: SE
authors.lastname: Humphries
authors.forename: J R
authors.initials: JR
authors.lastname: McEwan
mesh_terms: D000818:Animals; D002339:Carotid Arteries / Q000378:metabolism*; D020212:Carotid Artery Injuries; D002404:Catheterization; D017364:Collagenases / Q000235:genetics / Q000378:metabolism*; D018093:Gelatinases / Q000235:genetics / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2; D019278:Matrix Metalloproteinase 3 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism*; D014947:Wounds and Injuries / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D017364:Collagenases; D018093:Gelatinases; D008666:Metalloendopeptidases; D019278:Matrix Metalloproteinase 3; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9