To determine the physiological role of apolipoprotein (apo) A-IV, knockout mice were created by gene targeting in embryonic stem cells. In apoA-IV knockout mice, plasma cholesterol and triglyceride levels were reduced 25% and 44%, respectively, compared with controls. These changes were accounted for by decreased high density (HDL) and very low density lipoprotein (VLDL) levels, respectively, a...

We describe two techniques for radioimmunoassay of apolipoprotein A-I (apoA-I) in human plasma, each involving use of a non-ionic detergent, Tween-20, to expose antigenic sites, and one involving "IgG SORB" (a suspension of killed staphylococci) as a solid-phase separator. Tween-20 (3.75 g/L) decreased nonspecific binding and unmasked the antigenic sites on the apoA-I molecule in plasma to the ...

Cell biology methods have greatly influenced the elucidation of the biosynthetic pathways of apolipoproteins. In vitro and tissue culture systems allow the study, to a large extent, of the process of synthesis, intracellular processing, secretion, and extracellular processing of the major high density lipoprotein apoproteins apoA-I and A-II and also of a minor component, apoA-IV. Whereas the la...

We have generated transgenic mice carrying wild-type promoters of the human apolipoprotein A-I (apoA-I)-apoCIII gene cluster or promoters mutated in their hormone response elements. The wild-type cluster directed high levels of apoA-I gene expression in liver and intestine, moderate expression in kidney, and low to minimal expression in other tissues. It also directed high levels of chloramphen...

AIM Mice lacking apolipoprotein A-V (apoA-V) displayed an increase in serum triglyceride (TG) levels; however, the correlation of apoA-V levels with TG levels in humans is controversial, and the exact mechanism by which apoA-V affects TG levels is unclear. The aim of the present study was to clarify the impact of apoA-V on the lipoprotein subclass profile in preadolescent children, which has no...

The partitioning of apolipoprotein A-I (apoA-I) molecules in plasma between HDL-bound and -unbound states is an integral part of HDL metabolism. We used the surface plasmon resonance (SPR) technique to monitor in real time the reversible binding of apoA-I to HDL. Biotinylated human HDL(2) and HDL(3) were immobilized on a streptavidin-coated SPR sensor chip, and apoA-I solutions at different con...

Apolipoprotein A-I (apoA-I), the major protein constituent within high-density lipoprotein (HDL), has been associated with antiatherogenic protection by mechanisms that include reverse cholesterol transport and antiinflammatory functions. To evaluate the proposed protective function of apoA-I, proteins modified by nitrating oxidants were evaluated in the aortic tissue and plasma of mice lacking...

OBJECTIVE Low HDL cholesterol (HDL-C) and small HDL particle size may directly promote hyperglycemia. We evaluated associations of HDL-C, apolipoprotein A-I (apoA-I), and HDL-C/apoA-I with insulin secretion, insulin resistance, HbA1c, and long-term glycemic deterioration, reflected by initiation of pharmacologic glucose control. RESEARCH DESIGN AND METHODS The 5-year Fenofibrate Intervention ...

ApoA-1 (apolipoprotein A-1) is the main component of HDL (high-density lipoprotein) and stabilizes PON-1 (paraoxonase-1), which prevents lipid peroxidation and oxLDL (oxidized low-density lipoprotein) formation. Autoantibodies against apoA-1 [anti-(apoA-1) IgG] have been found in antiphospholipid syndrome and systemic lupus erythematosous, two diseases with an increased risk of thrombotic event...

Apolipoprotein A-II (apoA-II), the second major high-density lipoprotein (HDL) apolipoprotein, has been linked to familial combined hyperlipidemia. Human apoA-II transgenic mice constitute an animal model for this proatherogenic disease. We studied the ability of human apoA-II transgenic mice HDL to protect against oxidative modification of apoB-containing lipoproteins. When challenged with an ...