Published ahead of print on March 16, 2006, doi:10.1165/rcmb.2005-0115OC
© 2006 American Thoracic Society DOI: 10.1165/rcmb.2005-0115OC Microvascular Regeneration in Established Pulmonary Hypertension by Angiogenic Gene TransferThe Terrence Donnelly Vascular Biology Laboratories, Division of Cardiology, St. Michael's Hospital, and Department of Medicine and the McLaughlin Center for Molecular Medicine, University of Toronto, Toronto, Ontario, Canada Correspondence and requests for reprints should be addressed to Dr. Duncan J. Stewart, Dexter Hung-Cho Man Chair and Director of the Division of Cardiology, University of Toronto, St. Michael's Hospital, 30 Bond Street, Suite 6-050k Queen Wing, Toronto, ON, M5B 1W8 Canada. E-mail: stewartd{at}smh.toronto.on.ca Pulmonary arterial hypertension (PAH) is characterized by widespread loss of pulmonary microvasculature. Therefore we hypothesized that angiogenic gene therapy would reverse established PAH, in part restoring the lung microcirculation. Three weeks after monocrotaline (MCT) treatment, Fisher 344 rats were randomized to receive a total of either 1.5 x 106 syngeneic fibroblasts (FB) transfected with vascular endothelial growth factor A (VEGF), endothelial NO synthase (eNOS), or null-plasmid transfected FBs. Right ventricular systolic pressure (RVSP) was similarly increased in all MCT-treated groups at the time of gene transfer. Animals receiving the null-vector progressed to severe PAH by Day 35 (P < 0.001). In contrast, eNOS gene transfer significantly reduced RVSP at Day 35 compared with Day 21, whereas VEGF prevented further increases in RVSP over the subsequent 2 wk but did not reverse established PAH. RV hypertrophy was significantly reduced in both the eNOS-treated and VEGF-treated groups compared with the null-transfected controls. Fluorescent microangiography revealed widespread occlusion of the pre-capillary arterioles 21 d after MCT treatment, and animals receiving eNOS gene transfer exhibited the greatest improvement in the arteriolar architecture and capillary perfusion at Day 35. Cell-based eNOS gene transfer was more effective than VEGF in reversing established PAH, associated with evidence of regeneration of pulmonary microcirculation.
Key Words: cell-based gene transfer • eNOS • gene therapy • pulmonary hypertension • monocrotaline • vascular regeneration • vascular endothelial growth factor This article has been cited by other articles:
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