44 Apolipoprotein A-IV (apoA-IV) is secreted by the small intestine on chylomicrons into 45 intestinal lymph in response to fat absorption. Many physiological functions have been ascribed to 46 apoA-IV, including a role in chylomicron assembly and lipid metabolism, a mediator of reverse47 cholesterol transport, an acute satiety factor, regulator of gastric function, and finally, a modulator 48 ...

This article is available online at http://www.jlr.org are important for the effi ciency of the RCT pathway and the inverse relationship with the incidence of atherosclerosis. Plasma HDL comprises a heterogeneous assembly of different size particles, with variations in lipid and protein content ( 6, 7 ). Apolipoprotein (apo)A-I and apoA-II are the major protein constituents, comprising 70% and ...

OBJECTIVE Mast cell chymase is a chymotryptic heparin proteoglycan-bound neutral protease that exerts its activity in extracellular fluids. We studied the effect of chymase on the apolipoprotein compositions and the abilities of plasmas from apolipoprotein (apo)A-I-knockout (A-I-KO) and wild-type (C57BL/6J) mice to stimulate efflux of cellular cholesterol from mouse macrophage foam cells. MET...

Reduction of total and LDL cholesterol reduces atherosclerosis and clinical cardiovascular events. High density lipoprotein (HDL) cholesterol levels have a strong inverse association with atherosclerosis, and overexpression of apolipoprotein A-I (apoA-I), the major protein component of HDL, reduces atherosclerosis in hypercholesterolemic animals. However, little is known about the potential for...

Pig plasma phospholipid transfer protein (PLTP) facilitates interconversion of both human HDL3 and pig HDL into HDL subpopulations of large and small particles. We recently suggested that there are two essential parts in the conversion mechanism, i.e., the release of apoA-I and phospholipids and the fusion of apoA-I-depleted unstable particles. Based on their mass composition and electrophoreti...

ApoA-I(R160L)Oslo and apoA-I(P165R) are naturally occurring apolipoprotein (apo) A-I variants that are associated with low HDL-cholesterol in heterozygous carriers. We characterized the capacity of these variants to bind lipid, to activate lecithin:cholesterol acyltransferase (LCAT), and to promote efflux of biosynthetic cholesterol from porcine aortic smooth muscle cells (SMCs) or exogenous ch...

Exposure of HepG2 cells to 1% (v/v) dimethyl sulfoxide (DMSO), an effective free radical scavenger, for 24 h resulted in a 2-fold increase in the levels of apolipoprotein (apo) A-I mRNA and secreted protein, with no significant change in apoA-II, apoB, and apoE mRNA and protein levels. The induction of apoA-I was accompanied by a 50% increase in secreted HDL. Nuclear run-off assays indicated th...

We have determined the turnover rates for proapolipoprotein A-I (proapoA-I) and mature apolipoprotein A-I (apoA-I) in vivo in human and in rat. For the human study, high density lipoprotein (HDL)-associated 125I-labeled proapoA-I (A-I isoform 1) and 131I-labeled mature apoA-I (A-I isoforms 3, 4, and 5) were injected simultaneously into two normal volunteers. Blood samples were obtained serially...

To investigate the in vivo role that hepatic lipase (HL) plays in HDL metabolism independently of its lipolytic function, recombinant adenovirus (rAdV) expressing native HL, catalytically inactive HL (HL-145G), and luciferase control was injected in HL-deficient mice. At day 4 after infusion of 2 x 10(8) plaque-forming units of rHL-AdV and rHL-145G-AdV, similar plasma concentrations were detect...

BACKGROUND AND AIMS High-density lipoproteins (HDLs) may directly stimulate β-cell function and glucose metabolism. We determined the relationships of fasting high-density lipoprotein cholesterol (HDL-C), plasma apolipoprotein (apo) A-I and apoA-II, and HDL-C-to-apoA-I and HDL-C-to-apoA-II ratios, as estimates of HDL particle composition, with incident type 2 diabetes mellitus. METHODS A pros...