Elastase and matrix metalloproteinase inhibitors induce regression, and tenascin-C antisense prevents progression, of vascular disease
Kyle Northcote Cowan, … , Peter Lloyd Jones, Marlene Rabinovitch
Kyle Northcote Cowan, … , Peter Lloyd Jones, Marlene Rabinovitch
Published January 1, 2000
Citation Information: J Clin Invest. 2000;105(1):21-34. https://doi.org/10.1172/JCI6539.
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Article

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 αvβ3 ligand, osteopontin (OPN), in response to pro-proliferative cues provided by a proteolytic environment. OPN rescues MMP inhibitor–induced SMC apoptosis, and αvβ3 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

Kyle Northcote Cowan, Peter Lloyd Jones, Marlene Rabinovitch

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Figure 7

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Distribution of TN antisense transfection and suppression of TN. Distrib...
Distribution of TN antisense transfection and suppression of TN. Distribution of plasmid DNA following transfection was assessed indirectly by immunostaining for CAT, a gene product from another plasmid but delivered by the same HVJ-liposome technique. HVJ-liposomes are effective in transfecting the cells throughout the vessel wall ex vivo at high efficiency. Relative to IgG-stained controls (a), approximately 75–80% of cells are positive for CAT (b). Densitometric analysis of TN immunostaining (c) revealed an increase above preculture levels with mock or sense transfection. This was not only suppressed with TN antisense, but values were reduced below preculture levels. Reduction in TN protein assessed by immunohistochemistry correlated with decreased mRNA levels for the 2 TN transcripts as shown in the representative blot and densitometric data (d). With TN antisense, a decrease in TN mRNA transcripts at 7.3 and 6.4 kb was observed when normalized for hybridization and loading by GAPDH hybridization. Bar: 25 μm; graph bars: mean + SEM (n = 4); *P < 0.05 compared with sense and mock transfected; P < 0.05 compared with preculture Mct.