The present study aimed to determine plasma lipid levels in 95 HIV-infected patients divided into four groups according to the CD4 lymphocyte counts comparatively to a control group of 20 HIV-negative normolipidaemic subjects. A relationship between lipidic abnormalities and immune or nutritional status was also investigated. The patients below 200 CD4 lymphocyte mm-3 (groups 1 and 2) had significantly lower total cholesterol than the controls. The patients below 400 CD4 lymphocytes mm-3 (groups 1, 2, 3) had significantly higher triglycerides and Lp(a) but lower LDL-cholesterol than the controls. In all HIV-positive patients, whatever their CD4 lymphocyte count, HDL-C and apoA1 were lower than in the controls. By multivariate analysis triglycerides were positively correlated to acute opportunistic infections and to interferon-alpha levels, while cholesterol was negatively correlated to TNF-alpha, and LDL-C was positively correlated to albuminaemia. The latter parameter was the only lipidic value to correlate with nutritional markers. The contamination route, or the presence of wasting, was not correlated to any lipidic disorder.
Classic (complete) lecithin:cholesterol acyltransferase (LCAT) deficiency and Fish-eye disease (partial LCAT deficiency) are genetic syndromes associated with markedly decreased plasma levels of high density lipoprotein (HDL) cholesterol but not with an increased risk of atherosclerotic cardiovascular disease. We investigated the metabolism of the HDL apolipoproteins (apo) apoA-I and apoA-II in a total of five patients with LCAT deficiency, one with classic LCAT deficiency and four with Fish-eye disease. Plasma levels ofapoA-II were decreased to a proportionately greater extent (23% of normal) than apoA-1
In humans, diets rich in fish oil (containing n-3 FA) decrease the incidence of coronary artery diseases. This is thought to be caused by the induction in liver and skeletal muscle of genes involved in lipid oxidation, and to the repression in liver and adipose tissue of genes responsible for lipogenesis. n-3 FA are known to reduce the synthesis of FA and TG in the liver, resulting in a decrease of plasma concentrations of TG-rich lipoproteins. On the other hand, little is known of a possible effect of n-3 FA on HDL metabolism. To investigate this question, female C57Bl/6J mice were fed an n-3 FA-enriched diet for 16 wk. As expected from previous studies, we found that total cholesterol, TG, and phospholipids were reduced in the plasma of treated mice. We also found that HDL-cholesterol decreased after this treatment and that the in vivo fractional catabolic rate of HDL-cholesteryl ester was significantly higher in treated mice than in control mice fed a standard diet. Consistent with these results, treated mice exhibited increased uptake of HDL-cholesteryl ester in the liver. Moreover, quantitative reverse transcriptase-PCR analysis showed a two- to threefold increase in scavenger receptor B-1 gene expression. Taken together, these results suggest that an n-3 FA-enriched diet stimulates one step in the reverse cholesterol transport in mice, probably by increasing the amount of the scavenger receptor class B-1. These effects of n-3 FA on HDL metabolism may contribute to their beneficial effects on the vasculature.
To investigate the molecular events controlling reverse cholesterol transport, we compared gene expression of normal mouse liver to that of mice fed a long chain (LC) g g-3 fatty acid-enriched diet. Using cDNA microarrays, we assessed expression levels of 1176 genes, and we found that D-site binding protein (DBP) was three-fold increased in mice on a LC g g-3 fatty acid-rich diet compared to controls. DBP is known to increase transcriptional level of cholesterol 7K K-hydroxylase (C7K K), the rate-limiting enzyme for bile acid production and cholesterol excretion, and we found that C7K K mRNA was also up-regulated by LC g g-3 fatty acids. Moreover, liver X receptor-K K, another transcription factor up-regulating C7K K, was three-to four-fold increased in liver of treated mice. On the other hand, we demonstrated that bile acid and cholesterol excretion were two-fold increased. These results show that LC g g-3 fatty acids control cholesterol metabolism in mice at a new endpoint. ß 2004 Published by Elsevier B.V. on behalf of the Federation of European Biochemical Societies.
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