title: Elastase and matrix metalloproteinase inhibitors induce regression, and tenascin-C antisense prevents progression, of vascular disease.
abstract: Increased expression of the glycoprotein tenascin-C (TN) is associated with progression of clinical and experimental pulmonary hypertension. In cultured smooth muscle cells (SMCs) TN is induced by matrix metalloproteinases (MMPs) and amplifies the proliferative response to growth factors. Conversely, suppression of TN leads to SMC apoptosis. We now report that hypertrophied rat pulmonary arteries in organ culture, which progressively thicken in association with cell proliferation and matrix accumulation, can be made to regress by inhibiting either serine elastases or MMPs. This effect is associated with reduced TN, suppression of SMC proliferation, and induction of apoptosis. Selective repression of TN by transfecting pulmonary arteries with antisense/ribozyme constructs also induces SMC apoptosis and arrests progressive vascular thickening but fails to induce regression. This failure is related to concomitant expansion of a SMC population, which produces an alternative cell survival alpha(v)beta(3) ligand, osteopontin (OPN), in response to pro-proliferative cues provided by a proteolytic environment. OPN rescues MMP inhibitor-induced SMC apoptosis, and alpha(v)beta(3) blockade induces apoptosis in hypertrophied arteries. Our data suggest that proteinase inhibition is a novel strategy to induce regression of vascular disease because this overcomes the pluripotentiality of SMC-matrix survival interactions and induces coordinated apoptosis and resorption of matrix.
authors.affiliation: Division of Cardiovascular Research, Hospital for Sick Children. Department of Laboratory Medicine, Toronto, Ontario, Canada, M5G 1X8.
authors.forename: K N
authors.initials: KN
authors.lastname: Cowan
authors.forename: P L
authors.initials: PL
authors.lastname: Jones
authors.forename: M
authors.initials: M
authors.lastname: Rabinovitch
mesh_terms: D000818:Animals; D016375:Antisense Elements (Genetics) / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D008297:Male; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects; D053495:Osteopontin; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors*; D011480:Protease Inhibitors / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012795:Sialoglycoproteins / Q000502:physiology; D019063:Tenascin / Q000037:antagonists & inhibitors*; D014652:Vascular Diseases / Q000188:drug therapy*
chemical_list: D016375:Antisense Elements (Genetics); D011480:Protease Inhibitors; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D019063:Tenascin; D053495:Osteopontin; D010196:Pancreatic Elastase; D008666:Metalloendopeptidases