Therapeutic effect of eNOS-transfected endothelial progenitor cells on hemodynamic pulmonary arterial hypertension

Hemodynamic pulmonary arterial hypertension (HPAH) is a common symptom in congenital heart disease (CHD) patients with a left-to-right shunt. Endothelial NO synthase (eNOS) and endothelial-like progenitor cells result in significant improvement of right ventricular systolic pressure in established pulmonary arterial hypertension (PAH) models. We hypothesized that bone marrow (BM)-derived endothelial progenitor cells (EPCs) and eNOS would prevent HPAH in a newly established rat model. The heNOS gene was cloned into a PSUCMV vector, and a high-titer adenovirus was generated. Mononuclear cells (MNCs) from rat BM were differentiated into EPCs by treatment with various cytokines, and a high purity of EPCs (>70%) was confirmed using the markers Dil ac-LDL, UEA-1, vWF and Flk-1. An ideal rat HPAH model was successfully established based on right lung lobectomy, and was confirmed by pressure measurement and histological staining. heNOS was successfully transfected into EPCs, which were then transplanted into HPAH rats. Two weeks after transplantation, the systolic pulmonary arterial blood pressure (sPAP) was significantly reduced by heNOS-EPCs treatment and by transplantation of control EPCs. The high number of muscular pulmonary arteries and the thickness of the muscular coat characteristic of HPAH rats were clearly reversed or even restored to normal levels following transplantation of EPCs, particularly eNOS-EPCs. These findings indicate a critical role of eNOS in HPAH treatment and suggest that eNOS-transfected EPCs may provide an effective strategy for HPAH treatment in CHD patients.