Triglyceride-rich lipoproteins inhibit cholesterol efflux to apolipoprotein (apo) A1 from human macrophage foam cells

Palmer, A. Smythe; Murphy, Nuala; Graham, Annette

doi:10.1016/j.atherosclerosis.2003.12.001

Cited by 57 publications

(43 citation statements)

References 55 publications

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“…Furthermore, the amounts of TG and cholesterol in ox-LDL-treated cells were significantly higher than those in PBS-treated cells (2.1-and 6.7-fold compared to PBS-treated cells, respectively) (Fig. 1C), which have the same effects as foam cells (29).…”

Section: Identification Of Macrophages and Foam Cellssupporting

confidence: 50%

Identification of lipid droplet-associated proteins in the formation of macrophage-derived foam cells using microarrays

Song²,

Li³

et al. 2010

Int J Mol Med

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Abstract.A large number of macrophage-derived foam cells stores excessive neutral lipids in intracellular droplets, and plays a major role during the development of atherosclerosis. The formation and catabolism of intracellular lipid droplets (LDs) are regulated by LD-associated proteins, a group of proteins which are located on the surface of LDs and regulate the formation, morphology and lipolysis of LDs. In order to illustrate the function of LD-associated proteins during the process of atherosclerosis, the foam cell model is induced by oxidized low-density lipoprotein (ox-LDL) in macrophages originated from the THP-1 cell line, and cDNA microarrays are used to monitor the gene expression profiles of LD-associated proteins. Gene expression data show that 2% of changed genes are lipid binding genes during the transformation of foam cells. The major candidate genes, the cell deathinducing DFF45-like effector (CIDE) family and Perilipin, Adipophilin, and TIP47 (PAT) family, have different alterations during the formation of foam cells. CIDEB, CIDEC, Adipophilin, S3-12 and LSDP5 were up-regulated, while TIP47 was down-regulated. There was no significant change in CIDEA and Perilipin. These results were confirmed by real-time PCR and immunoblotting. This study presents a comprehensive analysis of the gene expression of LDassociated proteins during the differentiation of human foam cells, which may play an important role in the process of atherosclerosis.

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Section: Identification Of Macrophages and Foam Cellssupporting

confidence: 50%

Identification of lipid droplet-associated proteins in the formation of macrophage-derived foam cells using microarrays

Song²,

Li³

et al. 2010

Int J Mol Med

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“…TG-rich lipoproteins inhibit cholesterol efflux from human macrophage foam cells to lipid-poor apoA-I (21), indicating that the TGRL inhibits arterial reverse cholesterol transport and promote the formation of atherosclerotic lesions. Although VLDL and intermediate density lipoproteins (IDL) were used as TG-rich lipoproteins (d=1.006-1.019) from the report (21), the results also support that TG-enriched HDL has proatherogenic actions.…”

Section: Discussionsupporting

confidence: 48%

“…The alterations of lipid distribution have been reported as being strongly correlated to the malfunction of antioxidant ability of HDL and cholesterol efflux. Palmer et al (21) reported that TG-rich lipoproteins inhibit cholesterol efflux to apoA-I from human macrophage foam cells. Similarly, the Morton group reported that the elevated TG content diminishes the capacity of HDL to deliver CE via the SR-BI (22).…”

Section: Discussionmentioning

confidence: 99%

The functional and compositional properties of lipoproteins are altered in patients with metabolic syndrome with increased cholesteryl ester transfer protein activity

Park

Shin²,

Kim³

et al. 2009

Int J Mol Med

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Abstract.To compare the molecular composition and functional differences at the lipoprotein level, we analyzed individual lipoprotein fractions from male patients with metabolic syndrome (MetS) (n=10) and gender-and age-matched healthy controls (n=14). The MetS group had significantly higher obesity, blood pressure, serum cholesterol, triglyceride (TG), adiponectin, and uric acid levels than the control group, while the serum blood urea nitrogen and creatinine levels of the MetS group were in the normal range. The MetS group had much weaker serum antioxidant ability and were more susceptible to coppermediated low-density lipoprotein (LDL)-oxidation. TG and apoC-III co-accumulated with LDL, high density lipoprotein (HDL) 2 , and HDL 3 in the MetS group. The MetS group had serum amyloid A (SAA)-enriched HDL 2 and HDL 3 , although the serum level of SAA was not higher than in controls. The MetS group had significantly deprived paraoxonase (PON) activity in the serum and HDL, while the MetS group had 38% higher serum cholesteryl ester transfer protein (CETP) activity than that of the control group. Many serum parameters, such as TG, apoC-III, and uric acid, were elevated in the MetS group, and most of these measures were enriched in the LDL and HDL fractions rather than the very low density lipoprotein (VLDL) fraction. The lipid and apolipoprotein composition of HDL was severely altered and its beneficial functions were severely diminished. ApoA-I level was more readily detected in lipoprotein-deficient serum of the MetS group, indicating that the apoA-I exists in a lipid-free state. These results suggest that the MetS group had dysfunctional HDL that enriched TG, apoC-III, CETP, and SAA without antioxidant activity.

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“…We decided to use modified macrophages because they play a crucial role in the pathogenesis of atherosclerosis. This cell model has been used frequently in similar studies (32)(33)(34), and in addition, the presence of receptors involved in RCT (ABCA1, ABCG1, and SR-BI) was proved in these cells (35,36). Both whole diluted sera and isolated lipoproteins have been used in studies of CHE as acceptors of cellular cholesterol.…”

Section: Discussionmentioning

confidence: 99%

Replacement of dietary saturated FAs by PUFAs in diet and reverse cholesterol transport

Lesná

Suchánek

Kovář

et al. 2008

Journal of Lipid Research

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Dietary intervention is the first and usually successful approach in the treatment of high LDL cholesterol (LDL-C) concentration, but it is frequently accompanied by a decrease in HDL concentration. We studied 14 male volunteers on two different diets, high saturated fatty acid (SFA) and high PUFA, in a crossover design to test whether a decrease in HDL can affect reverse cholesterol transport from relabeled macrophages. A significant decrease of LDL-C (in mmol/l) after a PUFA diet compared with an SFA diet from 3.15 6 0.65 to 2.80 6 0.56 (P , 0.01) was accompanied by a significant decrease of HDL cholesterol (HDL-C) (in mmol/l) from 1.21 6 0.30 to 1.10 6 0.32 (P , 0.05). These changes did not affect cholesterol efflux (CHE) from macrophages (9.74 6 1.46% vs. 9.53 6 1.41%). There was no correlation between individual changes of HDL-C and changes of CHE. It is concluded that the decrease of HDL-C after successful dietary intervention of LDL-C is not accompanied by a decrease of CHE.-Kralova Lesna, I., P. Coronary heart disease (CHD) due to atherosclerosis of the coronary arteries is the main cause of mortality in the Western world (1). One of the typical phenotypes associated with increased risk of CHD includes increased LDL cholesterol (LDL-C) and reduced concentrations of HDL. Several epidemiological and physiological data indicate that a change in lifestyle (diet, physical training) can significantly improve lipoprotein profile and prognosis of CHD (2, 3). Meta-analysis of 60 controlled trials (4), focused on the effects of dietary FAs, clearly demonstrated a significant decrease in LDL concentration when saturated fatty acids (SFAs) in a diet were replaced with unsaturated FAs, and this decrease was accompanied by a significant decrease in HDL concentration. It is not clear whether such a decrease of HDL cholesterol (HDL-C) concentration compromises the otherwise atheroprotective effect of such a diet change.The importance of low concentrations of HDL as risk factor for cardiovascular diseases was initially demonstrated in Miller et al. (5), and this finding has been repeatedly confirmed (6, 7).HDL represents a large family of particles differing in size, shape, and composition. Among several protective actions of HDL [protection of endothelial function, and anti-oxidative, anti-inflamatory, and anti-aggregative effects (8-10)], the capacity of HDL to accept cellular lipids and reverse cholesterol transport (RCT) are thought to be the most important. RCT is the key pathway for efflux of cholesterol molecules to extracellular acceptors and their transport to the liver to be metabolized to bile acids. Despite the fact that RCT from macrophages contributes only a little to the whole centripetal transport of cholesterol, this pathway is crucial (11), inasmuch as accumulation of esterified cholesterol in these cells is one of the first features of atherosclerosis.RCT is a complex process involving several steps. First, unesterified cholesterol is carried out to the plasma membrane and then is taken up int...

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Triglyceride-rich lipoproteins inhibit cholesterol efflux to apolipoprotein (apo) A1 from human macrophage foam cells

Cited by 57 publications

References 55 publications

Identification of lipid droplet-associated proteins in the formation of macrophage-derived foam cells using microarrays

Identification of lipid droplet-associated proteins in the formation of macrophage-derived foam cells using microarrays

The functional and compositional properties of lipoproteins are altered in patients with metabolic syndrome with increased cholesteryl ester transfer protein activity

Replacement of dietary saturated FAs by PUFAs in diet and reverse cholesterol transport

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