Tangier disease is a rare familial disorder characterized by extremely low levels of apolipoprotein A-I (apoA-I) and high density lipoproteins (HDL). In normal subjects, proapoA-I is secreted into plasma and converted to mature apoA-I by the cleavage of the amino-terminal six amino acids with the major isoprotein in plasma being mature apoA-I. In contrast, in Tangier disease there is a marked r...

To test the hypothesis that apolipoprotein A-I (apoA-I) functions specifically to inhibit atherosclerosis independent of the level of high-density lipoprotein cholesterol (HDL-C) by promoting both reverse cholesterol transport and HDL antiinflammatory function in vivo, we established a murine atherosclerosis model of apoA-I deficiency in which the level of HDL-C is well maintained. ApoA-I / mic...

Tangier disease is a rare familial disorder characterized by enlarged orange tonsils, transient peripheral neuropathy, hepatosplenomegaly, and lymphadenopathy, as well as striking reductions in plasma high density lipoproteins (HDL) and their major protein constituents, apolipoproteins (apo)A-I and A-II. In order to test the hypothesis that Tangier patients have abnormal apoA-I or apoA-II, the ...

To investigate structure and function relations of a new member of the exchangeable apolipoprotein family that modulates plasma lipid levels, recombinant human apolipoprotein (apo) A-V was produced in Escherichia coli and isolated by a combination of nickel chelation affinity chromatography and reversed-phase HPLC. Antibodies directed against apoA-V were generated and employed in immunoblotting...

Estrogen replacement therapies, such as conjugated equine estrogen (CEE, Premarin), reduce the risk of coronary heart disease among postmenopausal women. In the present study, a HepG2 stable cell line (HepG2/S) that harbors a luciferase reporter gene cassette with the human apolipoprotein A-I (apoA-I) promoter region was used to examine the activity of CEE components in modulating human apoA-I ...

Apolipoprotein A-II (apoA-II) is the second major apolipoprotein following apolipoprotein A-I (apoA-I) in HDL. ApoA-II has multiple physiological functions and can form senile amyloid fibrils (AApoAII) in mice. Most circulating apoA-II is present in lipoprotein A-I/A-II. To study the influence of apoA-I on apoA-II and AApoAII amyloidosis, apoA-I-deficient (C57BL/6J.Apoa1⁻/⁻) mice were used. Apo...

ApoA-II is the second most abundant protein on HDL making up ∼ 20% of the total protein but its functions have still only been partially characterized. Recent methodological improvements have allowed for the recombinant expression and characterization of human apoA-II which shares only 55% sequence homology with murine apoA-II. Here we describe the purification of the two most common polymorphi...

The contribution of ABCA1-mediated efflux of cellular phospholipid (PL) and cholesterol to human apolipoprotein A-I (apoA-I) to the formation of pre beta 1-HDL (or lipid-poor apoA-I) is not well defined. To explore this issue, we characterized the nascent HDL particles formed when lipid-free apoA-I was incubated with fibroblasts in which expression of the ABCA1 was upregulated. After a 2 h incu...

To identify the role of a specific apoprotein other than apoE which might be responsible for the receptor-mediated uptake of high density lipoprotein (HDL) by rat hepatocytes, 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) was combined with rat apoE, apoA-I, or apoA-IV to form apoprotein-phospholipid complexes and the complexes were tested for their binding and uptake by primary rat hepatocyte...