Published online before print January 2, 2009, doi: 10.1161/CIRCRESAHA.108.184622
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© 2009 American Heart Association, Inc.
Molecular Medicine |
The Antiangiogenic Activity of rPAI-123 Inhibits Vasa Vasorum and Growth of Atherosclerotic Plaque
From the Angiogenesis Research Center (M.D., J.M., L.Z., K.M., B.S., A.H., S.S., M.S., M.J.M.-K.); Department of Surgery, Vascular Section (M.D., J.M., B.S., M.J.M.-K.); Department of Medicine, Cardiology Section (L.Z., K.M., A.H., S.S., M.S.); and Department of Microbiology (P.M.), Dartmouth Medical School, Lebanon, NH; and Section of Cardiovascular Medicine (M.S.), Department of Internal Medicine, Yale University School of Medicine, New Haven, Conn.
Correspondence to Mary Jo Mulligan-Kehoe, Dartmouth Medical School, Borwell 530 E, 1 Medical Center Dr, Lebanon, NH 03756. E-mail mary.j.mulligan-kehoe{at}dartmouth.edu
Plaque vascularity has been implicated in its growth and stability. However, there is a paucity of information regarding the origin of plaque vasculature and the role of vasa vasorum in plaque growth. To inhibit growth of vasa vasorum in atherogenic mice and assess its effect on plaque growth, we used a truncated plasminogen activator inhibitor (PAI)-1 protein, rPAI-123, that has significant antiangiogenic activity. Female LDLR–/–ApoB-48–deficient mice fed Paigen’s diet without cholate for 20 weeks received rPAI-123 treatment (n=21) for the last 6 weeks. Plaque size and vasa vasorum density were compared to 2 controls: mice fed Paigen’s diet and treated with saline for the last 6 weeks (n=16) and mice fed Paigen’s diet until the onset of treatment (n=14). The rPAI-123 treatment significantly reduced plaque area and plaque cholesterol in the descending aorta and plaque area in the innominate artery. Measurements of reconstructed confocal microscopy images of vasa vasorum demonstrate that rPAI-123 treatment decreased vasa vasorum area and length, which was supported by microCT images. Confocal images provide evidence for vascularized plaque in the saline-treated group but not in rPAI-123–treated mice. The increased vessel density in saline-treated mice is attributable, in part, to upregulated fibroblast growth factor-2 expression, which is inhibited by rPAI-123. In conclusion, rPAI-123 inhibits growth of vasa vasorum, as well as vessels within the adjacent plaque and vessel wall, through inhibition of fibroblast growth factor-2, leading to reduced plaque growth in atherogenic female LDLR–/–ApoB-48–deficient mice.
Key Words: atherosclerosis • angiogenesis inhibitors • FGF-2