Modest diet-induced weight loss reduces macrophage cholesterol efflux to plasma of patients with metabolic syndrome.

Background: Obesity-linked metabolic syndrome (MetS) is associated with a dyslipidemic profile that includes hypertriglyceridemia and low plasma high-density lipoprotein (HDL) cholesterol. HDL initiates reverse cholesterol transport via macrophage cholesterol efflux (MCE). Some hypothesize that dyslipidemic patients have impaired reverse cholesterol transport.

Serum opacity factor enhances HDL-mediated cholesterol efflux, esterification and anti inflammatory effects.

Serum opacity factor (SOF) is a streptococcal protein that disrupts the structure of human high density lipoproteins (HDL) releasing lipid-free apo A-I while forming a large cholesteryl ester-rich particle and a small neo HDL. Given its low cholesterol and high phospholipid contents, we tested the hypotheses that neo HDL is a better substrate for cholesterol esterification via lecithin:cholesterol acyltransferase (LCAT), better than HDL as an acceptor of THP-1 macrophage cholesterol efflux, and improves reduction of oxidized LDL-induced production of inflammatory markers. We observed that both cholesterol efflux and esterification were improved by recombinant (r)SOF treatment of whole plasma and that the underlying cause of the improved cholesterol esterification in plasma and macrophage cholesterol efflux to rSOF-treated plasma was due to the rSOF-mediated conversion of HDL to neo HDL.

HDL superphospholipidation enhances key steps in reverse cholesterol transport.

HDL-phospholipids (HDL-PL) play an important role in reverse cholesterol transport (RCT). Phosphatidylcholine (PC) is the most important phospholipid in RCT because it is the essential cholesterol-binding component of lipoproteins and is the acyl donor in the esterification of FC by lecithin:cholesterol acyltransferase (LCAT). FC efflux to sera is a positive anti-atherogenic function of HDL-PL.

Antiretroviral compounds and cholesterol efflux from macrophages.

Objective: HIV infection is associated with elevated risk of cardiovascular disease. The effect of antiretroviral drugs on metabolism of atherogenic very low and low density lipoproteins is well studied, but a possible effect of these drugs on reverse cholesterol transport is still unclear. The objective of this study was to assess the effect of various classes of anti-HIV drugs on cellular cholesterol efflux.

Enhancing apolipoprotein A-I-dependent cholesterol efflux elevates cholesterol export from macrophages in vivo.

Eight proteins potentially involved in cholesterol efflux [ABCA1, ABCG1, CYP27A1, phospholipid transfer protein (PLTP), scavenger receptor type BI (SR-BI), caveolin-1, cholesteryl ester transfer protein, and apolipoprotein A-I (apoA-I)] were overexpressed alone or in combination in RAW 264.7 macrophages. When apoA-I was used as an acceptor, overexpression of the combination of ABCA1, CYP27A1, PLTP, and SR-BI (Combination I) enhanced the efflux by 4.

The effect of cholesteryl ester transfer protein overexpression and inhibition on reverse cholesterol transport.

Aims: Cholesteryl ester transfer protein (CETP) has a well-established role in lipoprotein metabolism, but the effect of its overexpression or inhibition on the efficiency of reverse cholesterol transport (RCT) is unclear.

Methods And Results: Neither overexpression of CETP nor treatment with CETP inhibitor Torcetrapib of RAW 264.7 macrophages or HepG2 hepatocytes affected cholesterol efflux in vitro.

HIV infection and high density lipoprotein metabolism.

HIV infection and its treatment are associated with dyslipidemia, including hypoalphalipoproteinemia, and increased risk of cardiovascular disease. Parameters of HDL metabolism in HIV-positive patients were investigated in a cross-sectional study. The following groups of subjects were selected: (i) 25 treatment-naïve HIV-infected patients or HIV-infected patients on long therapy break, (ii) 28 HIV-infected patients currently treated with protease inhibitors, and (iii) 33 HIV-negative subjects.

Demethylation using the epigenetic modifier, 5-azacytidine, increases the efficiency of transient transfection of macrophages.

This study was aimed at developing a method for high-efficiency transient transfection of macrophages. Seven methods were evaluated for transient transfection of murine macrophage RAW 264.7 cells.

Purification and properties of a phospholipase A2/lipase preferring phosphatidic acid, bis(monoacylglycerol) phosphate, and monoacylglycerol from rat testis.

Phospholipase A(2) (PLA(2)) was purified to homogeneity from the supernatant fraction of rat testis homogenate. The purified 63-kDa enzyme did not require Ca(2+) ions for activity and exhibited both phosphatidic acid-preferring PLA(2) and monoacylglycerol lipase activities with a modest specificity toward unsaturated acyl chains. Anionic detergents enhanced these activities.