title: A novel model of cholesterol efflux from lipid-loaded cells.
abstract: Cholesterol efflux from lipid-loaded cells is a key athero-protective event that counteracts cholesterol uptake. The imbalance between cholesterol efflux and uptake determines the prevention or development of atherosclerosis. Many proteins and factors participate in the cholesterol efflux event. However, there are currently no systematic models of reverse cholesterol transport (RCT) that include most RCT-related factors and events. On the basis of recent research findings from other and our laboratories, we propose a novel model of one center and four systems with coupling transportation and networking regulation. This model represents a common way of cholesterol efflux; however, the systems in the model consist of different proteins/factors in different cells. In this review, we evaluate the novel model in vascular smooth muscle cells (VSMCs) and macrophages, which are the most important original cells of foam cells. This novel model consists of 1) a caveolae transport center, 2) an intracellular trafficking system of the caveolin-1 complex, 3) a transmembrane transport system of the ABC-A1 complex, 4) a transmembrane transport system of the SR-B1 complex, and 5) an extracelluar trafficking system of HDL/Apo-A1. In brief, the caveolin-1 system transports cholesterol from intracellular compartments to caveolae. Subsequently, both ABC-A1 and SR-B1 complex systems transfer cholesterol from caveolae to extracellular HDL/Apo-A1. The four systems are linked by a regulatory network. This model provides a simple and concise way to understand the dynamic process of atherosclerosis.
authors.affiliation: Department of Pharmacology, Central South University, Changsha, China. luodixian_2@163.com
authors.forename: Di-xian
authors.initials: DX
authors.lastname: Luo
authors.forename: De-liang
authors.initials: DL
authors.lastname: Cao
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiong
authors.forename: Xu-hong
authors.initials: XH
authors.lastname: Peng
authors.forename: Duan-fang
authors.initials: DF
authors.lastname: Liao
mesh_terms: D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D016632:Apolipoprotein A-I / Q000378:metabolism; D050197:Atherosclerosis / Q000378:metabolism; D001692:Biological Transport; D018955:CD36 Antigens / Q000378:metabolism; D021941:Caveolae / Q000378:metabolism; D051242:Caveolin 1 / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D005487:Foam Cells / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism; D008075:Lipoproteins, HDL / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*
chemical_list: D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D016632:Apolipoprotein A-I; D018955:CD36 Antigens; D051242:Caveolin 1; D008075:Lipoproteins, HDL; D002784:Cholesterol