Combination of a brief irrigation with tissue factor pathway inhibitor (TFPI) and adenovirus-mediated local TFPI gene transfer additively reduces neointima formation in balloon-injured rabbit carotid arteries.

Abstract
Background —Tissue factor pathway inhibitor (TFPI) is a physiological antagonist of TF. We tested whether a brief irrigation with TFPI protein (rTFPI) or TFPI gene transfer into injured arteries would suppress TF activity and reduce fibroproliferative changes and investigated whether a combination of these methods would show an additive effect. Methods and Results —We prepared adenoviruses expressing either TFPI (AdTFPI) or bacterial β-galactosidase (AdLacZ). Rabbit carotid arteries were balloon-injured and either infected with AdTFPI (or AdLacZ) or irrigated briefly with rTFPI (or saline). After injury, TF activity in arteries increased and was sustained; however, it was suppressed during the initial 24 hours by rTFPI irrigation (but not by gene transfer) and for a substantial period of time by TFPI gene transfer (but not by rTFPI irrigation). Four weeks later, the ratio of the intimal to medial areas was 34.3±8.7% (mean±SD, n=14) in saline-treated arteries and 33.3±4.2% in AdLacZ-infected arteries ( P =NS versus saline). However, it was reduced to 25.5±8.5% in rTFPI-irrigated arteries ( P P P P Conclusions —A combination of rTFPI irrigation and TFPI gene transfer overcomes the shortcomings shown by each method when used alone and achieves a full coverage of TF activity suppression, thereby enhancing their therapeutic effects without systemic side effects. This combination may be an effective strategy for the prevention of thrombosis and proliferative changes after angioplasty in humans.

This publication has 15 references indexed in Scilit: