Published online before print April 15, 2004, doi: 10.1161/01.ATV.0000128409.62292.d6
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© 2004 American Heart Association, Inc.
Vascular Biology |
Lipoprotein-Associated Phosphatidylethanol Increases the Plasma Concentration of Vascular Endothelial Growth Factor
From the Department of Internal Medicine, University of Oulu, Oulu, Finland.
Correspondence to Prof Markku J. Savolainen, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu, Finland. E-mail markku.savolainen{at}oulu.fi
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Abstract |
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Objective— To study whether qualitative changes in high-density lipoprotein (HDL) phospholipids mediate part of the beneficial effects of alcohol on atherosclerosis, we investigated whether phosphatidylethanol (PEth) in HDL particles affects the secretion of vascular endothelial growth factor (VEGF) from endothelial cells.
Methods and Results— PEth increased the secretion of VEGF into the culture medium of EA.hy 926 endothelial cells. The mitogen-activated protein kinase (MAPK) phosphorylation increased by 3.3-fold and protein kinase C (PKC) by 2.2-fold by PEth-containing HDL. Moreover, we showed that intravenous injection of PEth incorporated into HDL particles increased plasma concentration of VEGF by 2.4-fold in rats in vivo. Similar effect was observed when the rats were injected with HDL particles isolated from alcohol drinkers.
Conclusions— HDL particles containing PEth affect endothelial cells by MAPK and PKC signaling. This may mediate the effects of ethanol on the arterial wall by increasing VEGF secretion from endothelial vascular cells. That may explain, at least in part, the beneficial effect of moderate alcohol consumption on atherosclerosis.
The present study shows that phosphatidylethanol in HDL particles can regulate vascular endothelial growth factor in endothelial cells by increasing the phosphorylation of mitogen-activated protein kinase and protein kinase C. This may contribute to the beneficial effects of alcohol on atherosclerosis.
Key Words: alcohol • endothelial cells • vascular endothelial growth factor • lipoproteins • phospholipids
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Introduction |
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2s with plasma high-density lipoprotein (HDL) cholesterol concentration, HDL phospholipid concentration also correlates inversely with the severity of coronary artery disease.1 In addition, the ability of reconstituted HDL particles to inhibit endothelial cell adhesion molecule expression depends on their phospholipid composition, which also emphasizes the importance of phospholipids for the putative antiatherogenic functions of HDL particles.2
Previous epidemiological studies have shown that even light or moderate alcohol consumption has protective effects against coronary heart disease.3 A large part of the protective effects could be mediated by an increase in HDL cholesterol, but the exact mechanisms are not known.4–8 HDL may play a crucial role in reverse cholesterol transport. Some data suggest, however, that alcohol does not enhance reverse cholesterol transport despite its increasing effect on the plasma HDL cholesterol concentration.9–11
HDL may also have other functions unrelated to its role in reverse cholesterol transport, for example, HDL particles seem to be able to regulate the expression or abundance of various growth factors, endothelial nitric oxide synthase, cytokines, and adhesion molecules.2,12–17 Alcohol drinkers have elevated serum levels of adhesion molecules, but the mechanism of increase is not known.18
The fact that even light alcohol consumption of 1 drink twice per week protects against atherosclerosis compared with total abstinence is difficult to explain, because such a low level of drinking does not affect the HDL cholesterol concentration.8,19 A plausible explanation for the effect of moderate drinking may be provided by our new hypothesis suggesting that the sustained action of occasional drinking is caused by the involvement of lipoproteins as carriers of phosphatidylethanol (PEth).
PEth, structurally an ethanol adduct of phosphatidic acid (a lipid second messenger), is formed in the presence of ethanol and affects cellular metabolism and function.20–24 Ethanol itself has been shown to induce in vitro angiogenesis in the cultured endothelial cells by the activation of protein kinase C (PKC) and mitogen-activated protein kinase (MAPK).25
The present research demonstrates that PEth markedly increases the secretion of vascular endothelial growth factor (VEGF) in cultured endothelial cells and increases its plasma concentration in experimental animals in vivo. This effect of lipoprotein-associated PEth is mediated mainly by MAPK.
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Methods |
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Please see online Methods section at http://atvb.ahajournals.org for further details.
Subjects
Male alcoholic subjects (n=17) referred by general practitioners for withdrawal therapy to the Alcoholism Treatment Unit of Oulu and healthy nonalcoholic men (n=17) recruited from among the local paper mill employees were recruited for blood tests. Venous blood samples were taken from subjects after an overnight fast. The clinical characteristics of the study subjects are shown in Table I (available online at http://atvb.ahajournals.org).
Animals
Anesthetized male Sprague-Dawley rats were injected intravenously with native and PEth-modified HDL particles. Retro-orbital blood (0.3 mL) was collected into EDTA-containing tubes for VEGF determinations.
Isolation and Labeling of Lipoproteins
Lipoproteins were isolated from plasma by sequential ultracentrifugation on the basis of their density, as described.26–28 PEth was labeled,29 extracted,30 and separated by thin-layer chromatography (TLC). Iodination of the PEth-HDL was performed using IODO Beads Iodination Reagent (Perbio Science).
Chemical Analyses
Plasma and lipoprotein compositions were determined by kits of Roche Diagnostics GmbH (cholesterol, triglycerides), Wako Chemicals GmbH (phospholipids), and Bio-Rad Laboratories (proteins).
Cell Culture Experiments
Human endothelial EA.hy 926 cells were grown under standard conditions and incubated for different time points in the serum-free medium containing ethanol, phosphatidylcholine (PC), PEth, HDL, PEth-HDL, or alcoholic HDL.
Determination of PEth–HDL Cell Association and Selective PEth Uptake
EA.hy 926 cells were incubated for 5 hours with [125I]PEth-HDL and [14C]-labeled PEth-HDL, and the cell association of PEth-HDL and selective PEth uptake was determined, as described previously, detailed by Acton and Rigotti.31
Immunoassays
The VEGF concentration was measured from the human and rat plasma and cell culture medium by kits of R&D Systems.
Western Blot Analysis of PKC and p44/42 MAPK
Please see online Methods section at http://atvb.ahajournals.org for further details.
Statistical Analysis
The results are expressed as means and standard deviation (SD). The statistical significance of the differences between the means was assessed by independent samples 2-tailed Student t test or 1-way analysis of variance (ANOVA, Tukey test), as appropriate. P=0.05 was considered significant.
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Results |
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Characteristics of the Study Subjects
Age, body mass index (BMI), and daily alcohol intake data for the subjects are shown in Table I. Age and BMI did not differ between the groups, nor did VLDL cholesterol, plasma total triglyceride, or serum bilirubin concentration. The alcoholics had a 19% lower total cholesterol concentration (P<0.002) and a 39% lower LDL cholesterol concentration (P<0.0001) than the controls. The HDL cholesterol concentration was 28% higher in the group of alcoholics than in controls (P=0.062).
VEGF Concentration in the Plasma of the Study Subjects
To examine the hypothesis that alcohol drinking is capable of affecting the VEGF secretion or concentration in circulation, we collected plasma samples from controls and alcoholics. The plasma VEGF concentration was 39% higher in the alcoholics (74±37 pg/mL, n=17) than in the controls (Figure 1a) (53±23 pg/mL, n=17, P=0.056), although there was pronounced overlapping.
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indicates alcoholic subjects; 
, controls. b, The rats were injected with PBS (
indicates PBS, n=9), control HDL (
indicates control HDL, n=9), alcoholic HDL (
indicates alcoholic HDL, n=8), or PEth-HDL (• indicates PEth-HDL, n=9).
PEth Increases the Plasma VEGF Concentration in Rats
To prove that PEth present in lipoprotein particles increases the secretion of VEGF in vivo, the effects of PEth-modified HDL on plasma VEGF concentration were determined in vivo in rats. One group of rats (PBS) was injected intravenously with PBS buffer, whereas another group (control HDL) received injections of human HDL isolated from control subjects. The third group of rats (alcoholic HDL) was injected with HDL isolated from the plasma samples of alcoholics, and the fourth group (PEth-HDL) received intravenous injections of control HDL containing PEth added in vitro. Alcoholic HDL increased the plasma VEGF concentration 2-fold (from 41±5 to 79±8 pg/mL, P<0.003) compared with the control rats (PBS) 2 hours after the injection (Figure 1b). PEth-HDL increased the VEGF concentration by 144% (from 41±5 to 100±19 pg/mL) compared with the control rats (PBS) 3 hours after the injection (P<0.0001).
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Transfer of PEth From HDL Into Endothelial Cells
To find out if PEth is transferred from HDL particles into the endothelial cells, we used radiolabeled PEth-HDL particles.125I-PEth-HDL was used to follow the fate of the protein component and14C-PEth-HDL was used to determine the fate of the phospholipid component. To determine PEth-HDL— cell association (binding and internalization) and selective PEth uptake, we compared the fates of the phospholipid and protein components (Table). Heparin was used to separate the binding of HDL to a cell surface from the amount of internalized HDL. Lipoprotein binding was performed at 37°C and the cell-surface HDL release was determined at 4°C. Selective PEth uptake from HDL particle to the endothelial cells was more efficient (0.62% of the radioactivity) than the uptake of intact PEth-HDL particles (0.22% of the radioactivity) (P<0.004).
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Secretion of VEGF From Endothelial Cells
VEGF is an angiogenic growth factor and potentially also an endogenous vascular protective factor.32 Previous studies have shown that PEth formation in mononuclear cells is accompanied by responses in cell function.22 We hypothesized that PEth, either formed inside cells or associated with lipoproteins taken-up by cells, enhances VEGF secretion from cells. To test this hypothesis, we treated EA.hy 926 endothelial cells with different HDL particles and PEth liposomes. The VEGF concentration in the cell culture medium was 14% higher in the presence of alcoholic HDL (2.4±0.4 pg/mL) than in the presence of control HDL (2.1±0.2 pg/mL) (Figure 2a, P<0.05). The VEGF concentration in the cell culture medium was not affected by the presence of ethanol or HDL alone at the concentration of 0.2 mg/mL compared with nontreated cells (Figure 2b). By contrast, the VEGF concentration in the medium increased significantly (from 2.4±1.3 to 3.6±0.4 pg/mL, P<0.04) when both HDL and ethanol were added together into the culture medium (Figure 2b). The same effect was produced by PEth-HDL particles, which increased the VEGF concentration by 2.4-fold as compared with the control cells (from 2.4±1.3 to 5.7±1.2 pg/mL, P<0.002) (Figure 2b). The addition of ethanol into the medium did not further enhance the effect of PEth-HDL (Figure 2b). To prove that the increasing effect of VEGF secretion is caused by PEth per se, another set of experiments with phospholipid liposomes was performed (Figure 2c). The VEGF concentration in the cell culture medium was markedly increased in the presence of PEth (from 2.1±0.9 to 20.7±1.5 pg/mL, P<0.0002) (Figure 2c), whereas PC increased the VEGF concentration only from 2.1±0.9 to 5.2±3.0 pg/mL (P<0.05).
PEth Stimulates MAPK Kinase Activity in EA.hy 926 Cells
Ethanol induces in vitro angiogenesis by stimulating the MAPK activity in EA.hy 926 cells.25 Therefore, the effect of PEth-HDL on the MAPK phosphorylation was investigated. As shown in Figure 3, incubation of serum-starved EA.hy 926 cells in medium containing PEth-HDL for 10 minutes resulted in a 3.6-fold (P<0.006) increase in the MAPK (Erk1/Erk2) phosphorylation compared with control cells treated with PBS. HDL increased the Erk1/Erk2 phosphorylation by 3.3-fold (P<0.03) compared with control cells treated with PBS. The increase in the Erk1/Erk2 phosphorylation remained significantly elevated above control (PBS) levels when the cells were incubated with HDL for up to 15 minutes. PEth-HDL had a more extended effect on the Erk1/Erk2 phosphorylation than HDL alone. The phosphorylation induced by PEth-HDL remained elevated for up to 24 hours compared with control cells. PD098059 inhibited PEth-HDL-mediated stimulation of Erk1/Erk2 phosphorylation by 84% (Figure 4a) (P<0.004).
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PEth Stimulates PKC Activity in EA.hy 926 Cells
Because ethanol stimulates PKC activity in endothelial cells,25 the effect of PEth-HDL on the PKC phosphorylation was investigated. As shown in Figure 5, incubation of serum-starved EA.hy 926 cells in medium containing PEth-HDL for 10 minutes resulted in a 2.2-fold (P<0.05) increase in the PKC phosphorylation compared with control cells treated with PBS. HDL increased the phosphorylation by 2-fold (P<0.05) compared with control cells treated with PBS. PEth-HDL mediated stimulation of the PKC phosphorylation was slightly reduced by a PKC inhibitor Gö6983, but the result was not statistically significant (Figure 4a).
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PEth-Induced VEGF Secretion Is Inhibited by PKC and MAPK Inhibitors
Incubation of serum-starved EA.hy 926 cells for 15 minutes in a medium containing PEth-HDL increased VEGF secretion by 5-fold compared with cells treated with PBS (Figure 4b) (P<0.004). To ascertain whether the PEth-induced VEGF secretion is mediated through PKC and MAPK, the effect of inhibiting PKC and MAPK on this phenomenon was investigated. The maximal effect of the inhibitors was seen at the 15-minute time point (Figure 4b). The increase in VEGF secretion induced by PEth-HDL was inhibited by 40% in the presence of the PKC inhibitor, Gö6983, and by 25% in the presence of the MAPK inhibitor, PD098059.
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Discussion |
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PEth is formed in mammalian organs in the presence of ethanol and it is also present in the blood of subjects who have been drinking alcohol.20,33–35 PEth is formed especially in the lungs and the intestine, but also in vascular endothelial cells.36–38 The present study suggests that PEth affects vascular endothelial cells and may mediate at least part of the cardioprotective effects of ethanol. As a proof of principle, the present study demonstrates that lipoprotein-associated PEth increases the production of VEGF in endothelial cell cultures. VEGF was chosen as an end point marker because its function is considered beneficial in the later phases of atherosclerosis because of its ability to inhibit neointima formation.32 In addition, moderate levels of ethanol induce the expression and secretion of VEGF in cultured vascular smooth muscle cells and chick embryo chorioallantoic membranes25,39 and ethanol, at least at high concentrations, induces the in vitro angiogenesis through PKC and MAPK signaling pathways in endothelial cells.25 The present cell culture and animal experiments suggest that the increased plasma VEGF concentrations observed in alcohol drinkers may be caused by ethanol-induced qualitative alterations in the HDL particles of alcohol drinkers, and that this effect may be mediated by PEth through the MAPK and PKC signaling pathways.
The stimulation of the MAPK activity, as measured as an increase in the phosphorylation of Thr202/Tyr204 residues of Erk1/Erk2, was prolonged by PEth-HDL compared with the stimulation caused by native HDL. In addition, the partial inhibition of PEth-induced VEGF secretion by specific MAPK inhibitor PD098059 indicates that the MAPK pathway could be one of the signaling routes between PEth and VEGF secretion in endothelial cells. This is in accordance to a recent report in hepatocytes.40 The PEth-induced stimulation of the phosphorylation of PKC and the partial inhibition by Gö6983 of the PEth-induced VEGF secretion from the endothelial cells indicate that the PKC pathway could also contribute to the PEth-induced VEGF secretion in endothelial cells. Moreover, this study gives a plausible explanation for the ethanol-induced increase in plasma VEGF level by demonstrating in an animal model that the addition of an ethanol-induced abnormal lipid, PEth, into HDL particles is also capable of elevating plasma VEGF levels. However, we cannot exclude the contribution of other compounds present in HDL isolated from plasma of alcohol drinkers, despite the apparent similarity in the VEGF response in vivo.
The present study provides evidence that PEth-HDL may interfere with the vascular endothelium in a different manner than native HDL. This qualitative difference leads into increased concentration of VEGF in plasma in vivo and also in endothelial cells, which line the blood vessel and are in close contact with smooth muscle cells and macrophages. All of these cells may sense changes in the environment when the composition and concentration of lipoproteins are altered, eg, by ethanol.
The mechanism of the cardioprotective effect of moderate alcohol drinking has been elusive. For most hours of the day, ethanol is not present in the body of a social drinker. Therefore, the direct effects of ethanol on vascular endothelial cells might be only temporary if they are confined to the period of ethanol abundance, even though PEth may be metabolized more slowly than PC. The relatively long half-life of lipoproteins may prolong the presence of PEth in the body from a few hours to several days even in an occasional drinker.8,19 This kind of "memory molecule" might help to explain the beneficial effects of light or moderate drinking on cardiovascular diseases. The effect of PEth may last even longer, because erythrocytes may act as a reservoir of PEth,41,42 and because this abnormal phospholipid is transported between lipoproteins,23 lipoproteins may transport PEth from erythrocytes to vascular wall cells.41 More sensitive methods are needed for the measurement of PEth content in lipoprotein fractions, however. This work is currently underway in our laboratory.
In conclusion, ethanol not only alters the quantity of lipoproteins or their components but also may cause incorporation of abnormal derivatives of lipids and proteins into lipoproteins, and may therefore have marked and sustained effects on all vascular cells.43 Further studies are needed to elucidate more detailed mechanisms of how PEth regulates the VEGF function and secretion in endothelial and in other vascular cells.
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Acknowledgments |
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Acknowledgments
We acknowledge the technicians of the laboratory in the Department of Internal Medicine at the University of Oulu for their skillful technical assistance. We are also very grateful to the patients and staff of the Kiviharju Alcoholism Treatment Unit and Stora Enso Oyj Fine Paper, Oulu Mill for their cooperation. This work was financially supported by the Academy of Finland, Sigrid Juselius Foundation, Inkeri and Mauri Vänskä Foundation, and the Finnish Foundation for Alcohol Studies.
Received January 21, 2004; accepted March 19, 2004.
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References |
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TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
- Lan HS, Duncan R, Schob AH, Chakko SC, Mulingtapang R, He JL, Perez GO. Serum levels of high-density lipoprotein phospholipids correlate inversely with severity of angiographically defined coronary artery disease. Atherosclerosis. 2000; 152: 469–473.[CrossRef][Medline] [Order article via Infotrieve]
- Baker PW, Rye KA, Gamble JR, Vadas MA, Barter PJ. Phospholipid composition of reconstituted high density lipoproteins influences their ability to inhibit endothelial cell adhesion molecule expression. J Lipid Res. 2000; 41: 1261–1267.
[Abstract/Free Full Text] - Klatsky AL. Epidemiology of coronary heart disease—influence of alcohol. Alcohol Clin Exp Res. 1994; 18: 88–96.[CrossRef][Medline] [Order article via Infotrieve]
- Criqui MH, Cowan LD, Tyroler HA, Bangdiwala S, Heiss G, Wallace RB, Cohn R. Lipoproteins as mediators for the effects of alcohol consumption and cigarette smoking on cardiovascular mortality: results form the Lipid Research Clinics Follow-up Study. Am J Epidemiol. 1987; 126: 629–637.
[Abstract/Free Full Text] - Langer RD, Criqui MH, Reed DM. Lipoproteins and blood pressure as biological pathways for effect of moderate alcohol consumption on coronary heart disease. Circulation. 1992; 85: 910–915.
[Abstract/Free Full Text] - Suh I, Shaten BJ, Cutler JA, Kuller LH. Alcohol use and mortality from coronary heart disease: the role of high- density lipoprotein cholesterol. The Multiple Risk Factor Intervention Trial Research Group. Ann Intern Med. 1992; 116: 881–887.
- Paunio M, Heinonen OP, Virtamo J, Klag MJ, Manninen V, Albanes D, Comstock GW. HDL cholesterol and mortality in Finnish men with special reference to alcohol intake. Circulation. 1994; 90: 2909–2918.
[Abstract/Free Full Text] - Rimm EB, Williams P, Fosher K, Criqui M, Stampfer MJ. Moderate alcohol intake and lower risk of coronary heart disease: meta- analysis of effects on lipids and haemostatic factors. BMJ. 1999; 319: 1523–1528.
[Abstract/Free Full Text] - Karsenty C, Baraona E, Savolainen MJ, Lieber CS. Effects of chronic ethanol intake on mobilization and excretion of cholesterol in baboons. J Clin Invest. 1985; 75: 976–986.
- Rao MN, Liu QH, Marmillot P, Seeff LB, Strader DB, Lakshman MR. High-density lipoproteins from human alcoholics exhibit impaired reverse cholesterol transport function. Metabolism. 2000; 49: 1406–1410.[CrossRef][Medline] [Order article via Infotrieve]
- Avdulov NA, Chochina SV, Igbavboa U, Wood WG. Cholesterol efflux to high-density lipoproteins and apolipoprotein A-I phosphatidylcholine complexes is inhibited by ethanol: role of apolipoprotein structure and cooperative interaction of phosphatidylcholine and cholesterol. Biochemistry. 2000; 39: 10599–10606.[CrossRef][Medline] [Order article via Infotrieve]
- Rämet ME, Rämet M, Nickerson M, Savolainen MJ, Malzone A, Karas RH. High-density lipoprotein increases the abundance of eNOS protein in human vascular endothelial cells by increasing its half-life. J Am Coll Cardiol. 2003; 41: 2288–2297.
[Abstract/Free Full Text] - Kuvin JT, Rämet ME, Patel AR, Pandian NG, Mendelsohn ME, Karas RH. A novel mechanism for the beneficial vascular effects of high-density lipoprotein cholesterol: enhanced vasorelaxation and increased endothelial nitric oxide synthase expression. Am Heart J. 2002; 144: 165–172.[CrossRef][Medline] [Order article via Infotrieve]
- Nofer JR, Kehrel B, Fobker M, Levkau B, Assmann G, von Eckardstein A. HDL and arteriosclerosis: beyond reverse cholesterol transport. Atherosclerosis. 2002; 161: 1–16.[CrossRef][Medline] [Order article via Infotrieve]
- Cockerill GW, Huehns TY, Weerasinghe A, Stocker C, Lerch PG, Miller NE, Haskard DO. Elevation of plasma high-density lipoprotein concentration reduces interleukin-1-induced expression of E-selectin in an in vivo model of acute inflammation. Circulation. 2001; 103: 108–112.
[Abstract/Free Full Text] - Cockerill GW, Saklatvala J, Ridley SH, Yarwood H, Miller NE, Oral B, Nithyanathan S, Taylor G, Haskard DO. High-density lipoproteins differentially modulate cytokine-induced expression of E-selectin and cyclooxygenase-2. Arterioscler Thromb Vasc Biol. 1999; 19: 910–917.
[Abstract/Free Full Text] - Cockerill GW, Rye KA, Gamble JR, Vadas MA, Barter PJ. High-density lipoproteins inhibit cytokine-induced expression of endothelial cell adhesion molecules. Arterioscler Thromb Vasc Biol. 1995; 15: 1987–1994.
[Abstract/Free Full Text] - Sacanella E, Estruch R, Badia E, Fernandez-Sola J, Nicolas JM, Urbano-Marquez A. Chronic alcohol consumption increases serum levels of circulating endothelial cell/leucocyte adhesion molecules E-selectin and ICAM-1. Alcohol Alcohol. 1999; 34: 678–684.
[Abstract/Free Full Text] - McConnell MV, Vavouranakis I, Wu LL, Vaughan DE, Ridker PM. Effects of a single, daily alcoholic beverage on lipid and hemostatic markers of cardiovascular risk. Am J Cardiol. 1997; 80: 1226–1228.[CrossRef][Medline] [Order article via Infotrieve]
- Alling C, Gustavsson L,
nggård E. An abnormal phospholipid in rat organs after ethanol treatment. FEBS Lett. 1983; 152: 24–28.[CrossRef][Medline]
[Order article via Infotrieve]
- Asaoka Y, Kikkawa U, Sekiguchi K, Shearman MS, Kosaka Y, Nakano Y, Satoh T, Nishizuka Y. Activation of a brain-specific protein kinase C subspecies in the presence of phosphatidylethanol. FEBS Lett. 1988; 231: 221–224.[CrossRef][Medline] [Order article via Infotrieve]
- Lundqvist C, Alling C, Aradottir S, Gustavsson L. Agonist-stimulated and basal phosphatidylethanol formation in neutrophils from alcoholics. Alcohol Clin Exp Res. 1994; 18: 580–586.[CrossRef][Medline] [Order article via Infotrieve]
- Shukla SD, Sun GY, Gibson WW, Savolainen MJ, Alling C, Hoek JB. Ethanol and lipid metabolic signaling. Alcohol Clin Exp Res. 2001; 25: 33S–39S.[CrossRef][Medline] [Order article via Infotrieve]
- Magai RM, Shukla SD. Metabolic fate of [14C]-ethanol into endothelial cell phospholipids including platelet-activating factor, sphingomyelin and phosphatidylethanol. J Biomed Sci. 2001; 8: 143–150.[Medline] [Order article via Infotrieve]
- Jones MK, Sarfeh IJ, Tarnawski AS. Induction of in vitro angiogenesis in the endothelial-derived cell line, EA hy926, by ethanol is mediated through PKC and MAPK. Biochem Biophys Res Commun. 1998; 249: 118–123.[CrossRef][Medline] [Order article via Infotrieve]
- Savolainen MJ, Hannuksela M, Seppänen S, Kervinen K, Kesäniemi YA. Increased high-density lipoprotein cholesterol concentration in alcoholics is related to low cholesteryl ester transfer protein activity. Eur J Clin Invest. 1990; 20: 593–599.[Medline] [Order article via Infotrieve]
- Hannuksela M, Marcel YL, Kesäniemi YA, Savolainen MJ. Reduction in the concentration and activity of plasma cholesteryl ester transfer protein by alcohol. J Lipid Res. 1992; 33: 737–744.[Abstract]
- Liinamaa MJ, Kesäniemi YA, Savolainen MJ. Lipoprotein composition influences cholesteryl ester transfer in alcohol abusers. Ann Med. 1998; 30: 316–322.[Medline] [Order article via Infotrieve]
- Yang SF, Freer S, Benson AA. Transphosphatidylation by phospholipase D. J Biol Chem. 1967; 242: 477–484.
[Abstract/Free Full Text] - Meacci E, Vasta V, Farnararo M, Bruni P. Bradykinin increases ceramide and sphingosine content in human fibroblasts: possible involvement of glycosphingolipids. Biochem Biophys Res Commun. 1996; 221: 1–7.[CrossRef][Medline] [Order article via Infotrieve]
- Acton S, Rigotti A. Cellular assays for lipoprotein receptors. Methods Mol Biol. 1998; 110: 253–266.[Medline] [Order article via Infotrieve]
- Zachary I, Mathur A, Ylä-Herttuala S, Martin J. Vascular protection: A novel nonangiogenic cardiovascular role for vascular endothelial growth factor. Arterioscler Thromb Vasc Biol. 2000; 20: 1512–1520.
[Abstract/Free Full Text] - Benthin G, nggård E, Gustavsson L, Alling C. Formation of phosphatidylethanol in frozen kidneys from ethanol-treated rats. Biochim Biophys Acta. 1985; 835: 385–389.[Medline]
[Order article via Infotrieve]
- Gunnarsson T, Karlsson A, Hansson P, Johnson G, Alling C, Odham G. Determination of phosphatidylethanol in blood from alcoholic males using high-performance liquid chromatography and evaporative light scattering or electrospray mass spectrometric detection. J Chromatogr B Biomed Sci Appl. 1998; 705: 243–249.[CrossRef][Medline] [Order article via Infotrieve]
- Varga A, Hansson P, Lundqvist C, Alling C. Phosphatidylethanol in blood as a marker of ethanol consumption in healthy volunteers: comparison with other markers. Alcohol Clin Exp Res. 1998; 22: 1832–1837.[CrossRef][Medline] [Order article via Infotrieve]
- Varga A, Hansson P, Johnson G, Alling C. Normalization rate and cellular localization of phosphatidylethanol in whole blood from chronic alcoholics. Clin Chim Acta. 2000; 299: 141–150.[CrossRef][Medline] [Order article via Infotrieve]
- Natarajan V, Taher MM, Roehm B, Parinandi NL, Schmid HH, Kiss Z, Garcia JG. Activation of endothelial cell phospholipase D by hydrogen peroxide and fatty acid hydroperoxide. J Biol Chem. 1993; 268: 930–937.
[Abstract/Free Full Text] - Saijonmaa O, Nyman T, Hohenthal U, Fyhrquist F. Endothelin-1 is expressed and released by a human endothelial hybrid cell line (EA.hy 926). Biochem Biophys Res Commun. 1991; 181: 529–536.[CrossRef][Medline] [Order article via Infotrieve]
- Gu JW, Elam J, Sartin A, Li W, Roach R, Adair TH. Moderate levels of ethanol induce expression of vascular endothelial growth factor and stimulate angiogenesis. Am J Physiol Regul Integr Comp Physiol. 2001; 281: R365–R372.
[Abstract/Free Full Text] - Aroor AR, Custer GW, Weng YI, Lee YJ, Shukla SD. Phosphotidylethanol mimics ethanol modulation of p42/44 mitogen-activated protein kinase signaling in hepatocytes. Alcohol Alcohol. 2002; 37: 534–539.
[Abstract/Free Full Text] - Varga A, Alling C. Formation of phosphatidylethanol in vitro in red blood cells from healthy volunteers and chronic alcoholics. J Lab Clin Med. 2002; 140: 79–83.[Medline] [Order article via Infotrieve]
- Aradottir S, Moller K, Alling C. Phosphatidylethanol formation and degradation in human and rat blood. Alcohol Alcohol. 2004; 39: 8–13.
[Abstract/Free Full Text] - Hannuksela ML, Liisanantti MK, Savolainen MJ. Effect of alcohol on lipids and lipoproteins in relation to atherosclerosis. Crit Rev Clin Lab Sci. 2002; 39: 225–283.[CrossRef][Medline] [Order article via Infotrieve]
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