Genetic ablation of caveolin-1 confers protection against atherosclerosis.
OBJECTIVE
The development of atherosclerosis is a process characterized by the accumulation of lipids in the form of modified lipoproteins in the subendothelial space. This initiating step is followed by the subsequent recruitment and proliferation of other cell types, including monocytes/macrophages and smooth muscle cells. Here, we evaluate the potential role of caveolae membrane domains in the pathogenesis of atherosclerosis by using apolipoprotein E-deficient (ApoE-/-) mice as a model system.


RESULTS
Caveolin-1 (Cav-1) is a principal structural protein component of caveolae membrane domains. To directly assess the in vivo role of caveolae and Cav-1 in atherosclerosis, we interbred Cav-1-/- mice with ApoE-/- mice. Interestingly, loss of Cav-1 resulted in a dramatic >2-fold increase in non-HDL plasma cholesterol levels in the ApoE-/- background. However, despite this hypercholesterolemia, we found that loss of Cav-1 gene expression was clearly protective against the development of aortic atheromas, with up to an approximately 70% reduction in atherosclerotic lesion area. Mechanistically, we demonstrated that loss of Cav-1 resulted in the dramatic downregulation of certain proatherogenic molecules, namely, CD36 and vascular cell adhesion molecule-1.


CONCLUSIONS
Taken together, our results indicate that loss of Cav-1 can counteract the detrimental effects of atherogenic lipoproteins. Thus, Cav-1 is a novel target for drug development in the pharmacologic prevention of atheroma formation. Our current data also provide the first molecular genetic evidence to support the hypothesis that caveolar transcytosis of modified lipoproteins (from the blood to the sub-endothelial space) is a critical initiating step in atherosclerosis.
Frank
Philippe G
PG
Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Golding 202, Bronx, NY 10461, USA.
Lee
Hyangkyu
H
Park
David S
DS
Tandon
Narendra N
NN
Scherer
Phillip E
PE
Lisanti
Michael P
MP
D000818:Animals; D001018:Aortic Diseases / Q000235:genetics / Q000517:prevention & control; D001057:Apolipoproteins E / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D001161:Arteriosclerosis / Q000235:genetics / Q000517:prevention & control*; D018955:CD36 Antigens / Q000096:biosynthesis / Q000235:genetics; D021941:Caveolae / Q000502:physiology*; D051242:Caveolin 1; D022461:Caveolins / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D002791:Cholesterol, Dietary / Q000633:toxicity; D003433:Crosses, Genetic; D004036:Diet, Atherogenic; D005260:Female; D006937:Hypercholesterolemia / Q000235:genetics; D008074:Lipoproteins / Q000097:blood; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis / Q000235:genetics
D001057:Apolipoproteins E; D018955:CD36 Antigens; C495541:Cav1 protein, mouse; D051242:Caveolin 1; D022461:Caveolins; D002791:Cholesterol, Dietary; D008074:Lipoproteins; D019010:Vascular Cell Adhesion Molecule-1