Selective augmentation of prostacyclin production by combined prostacyclinsynthase and cyclooxygenase-1 gene transfer

Background-We tested the hypothesis that combined cyclooxygenase-1 (COX-1) and prostacyclin synthase (PGIS) gene transfer selectively augments prostac yclin production without a concurrent overproduction of other prostanoids. Methods and Results-ECV304 cells were transfected with bicistronic pCOX-1/P GIS: versus pcOX-1 or pPGIS, and prostanoids were analyzed. Contrary to the high prostaglandin E-2 synthesis in pCOX-1 transfected cells, selective pr ostacyclin formation was noted with bicistronic plasmid transfection. Next, we determined the optimal ratio of Ad-COX-1 to Ad-PGIS by transfecting hum an umbilical vein endothelial cells with various titers of these 2 adenovir al constructs and determined the level of protein expression and prostanoid synthesis. Our results show that optimal ratios of adenoviral titers to ac hieve a large prostacyclin augmentation without overproduction of prostagla ndin E-2 or F-2 alpha were 50 to 100 plaque forming units (pfu) of Ad-COX-1 to 50 pfu of Ad-PGIS per cell. A higher Ad-PGIS to Ad-COX-1 ratio caused a paradoxical decline in prostacyclin synthesis. Conclusions-Prostacyclin synthesis can be selectively augmented by cotransf ecting endothelial cells with an optimal ratio of COX-1 to PGIS, Combined C OX-1 and PGIS gene transfer has the potential for therapeutic augmentation of prostacyclin.