Expression of Fas Ligand in Arteries of Hypercholesterolemic Rabbits Accelerates Atherosclerotic Lesion Formation

Abstract

Abstract-Fas ligand (FasL) is expressed by cells of the arterial wall and is present in human atherosclerotic lesions.However, the role of FasL in modifying the initiation and progression of atherosclerosis is unclear.

Increased expression of urokinase during atherosclerotic lesion development causes arterial constriction and lumen loss, and accelerates lesion growth

“…This animal model, developed in our laboratory, involves intraluminal infusion of adenoviral vectors to carotid arteries of hypercholesterolemic rabbits. Adenoviral vector infusion in this setting initiates subendothelial accumulation of macrophages and smooth muscle cells, leading to formation of intimal lesions that are histologically and ultrastructurally similar to those of early human atherosclerosis (15). Gene transfer in this model is almost exclusively to endothelium (16), which in the present study is genetically modified to secrete increased levels of uPA.…”

“…In vivo experiments were performed with specificpathogen-free adult male New Zealand White rabbits (2.5-3.5 kg, Charles River Breeding Laboratories). For atherosclerosis studies, hypercholesterolemia (400-700 mg͞dl) was induced with a diet containing 0.25% cholesterol and 3% soybean oil (15). All animal protocols were approved by the Committee on Animal Research of the University of California, San Francisco.…”

“…In vivo gene transfer to carotid artery endothelium was performed as described (15). For the doseresponse study, viral stocks were diluted to 1 ϫ 10 8 to 4 ϫ 10 9 plaque-forming units (pfu) per ml (2 ϫ 10 10 to 8 ϫ 10 11 particles per ml).…”

“…For expression studies, arteries were harvested at 1-14 days after gene transfer and either used immediately for a plasminogen activation assay or snap frozen in liquid nitrogen for later measurement of mRNA or direct uPA activity. For histologic analyses, arteries were perfusion-fixed in situ at physiologic pressure (15) and harvested 1-4 weeks after gene transfer.…”

“…Macrophages were detected by immunostaining with the RAM-11 antibody (15). Fibrin(ogen) was detected by staining 1-week arteries with a mouse monoclonal antibody to human fibrin(ogen) (#750, American Diagnostica, Greenwich, CT).…”