on August 10, 2009
Published online before print March 19, 2009, doi: 10.1161/ATVBAHA.109.186502
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Submitted on March 13, 2008
Accepted on March 9, 2009
SR-BI Selective Lipid Uptake. Subsequent Metabolism of Acute Phase HDL
Maria C. de Beer *;
From the Graduate Center for Nutritional Science (M.C.d.B., N.R.W., N.L.W., J.M.W., A.J., D.R.v.d.W., F.C.d.B.), the Cardiovascular Research Center (M.C.d.B., N.R.W., N.L.W., J.M.W., A.J., D.R.v.d.W., F.C.d.B.), and the Departments of Physiology (M.C.d.B.) and Internal Medicine (N.R.W., N.L.W., J.M.W., A.J., D.R.v.d.W., F.C.d.B.), University of Kentucky Medical Center, Lexington; and the Department of Veterans Affairs Medical Center (F.C.d.B.), Lexington, Ky.
* To whom correspondence should be addressed. E-mail: mdebeer{at}uky.edu.
Objective—The purpose of this study was to investigate the interaction of SAA and SR-BI in remodeling of acute phase HDL (AP HDL).
Methods and Results—We used SAA and SR-BI adenoviral vector expression models to study the interaction between these entities. SR-BI processing of mouse AP HDL generated progressively smaller discreet HDL particles with distinct apolipoprotein compositions. SR-BI actions segregated apolipoproteins with the smallest particles containing only apoA-I. Larger remnants contained apoA-I, apoA-II, and SAA. Small apoA-I only particles failed to associate with preformed HDL, whereas larger remnants readily did. The presence of SAA on SR-BI-processed HDL particles propelled apoA-I to a small lipid-poor form and accelerated apoA-I catabolism.
Conclusions—Data indicate that after core and surface HDL lipid perturbation by SR-BI, SAA propels apoA-I to a small lipid-poor form while accelerating HDL metabolism.
Key words: SAA • HDL • inflammation • SR-BI • metabolism