Gene transfer of human prostacyclin synthase into the liver is effective for the treatment of pulmonary hypertension in rats

Background: As one of the future strategies of advanced pulmonary hypertension, intrinsic prostacyclin drug delivery using gene therapy may be useful. We investigated whether transfer of the prostacyclin synthase gene into the liver could ameliorate monocrotaline-induced pulmonary hypertension in rats. Methods: The human prostacyclin synthase gene was transfected into the liver of rats with monocrotaline-induced pulmonary hypertension. Hemodynamic indices, blood samples, lung tissues, and survival curves were evaluated between rats receiving the gene and control rats. Results: High levels of prostacyclin synthase gene expression were found in the hepatocytes of the prostacyclin synthase group. The level of 6-keto-prostaglandin F-1alpha was significantly higher in the prostaeyclin synthase group (prostaeyclin synthase, 35.4 +/- 4.4 ng/mL; control, 22.3 +/- 3.3 ng/mL; P = .0436). The right ventricular/femoral artery pressure ratio was significantly lower in the prostacyclin synthase group than in the control group (prostacyclin synthase, 0.60 +/- 0.039; control, 0.88 +/- 0.051; P = .0036). The endothelin-1 levels in the lung tissues were significantly lower in the prostacyclin synthase group than in the control group (prostacyclin synthase, 10.42 +/- 2.01 pg/mg protein; control, 19.94 +/- 2.82 pg/mg protein: P = .0176). The survival ratio was significantly higher in the prostacyclin synthase group than the control group (P =.0375). Conclusion: This drug delivery system using gene transfer can be considered as an alternative for continuous intravenous prostacyclin infusion for pulmonary hypertension.