Phospholipid composition of reconstituted high density lipoproteins influences their ability to inhibit endothelial cell adhesion molecule expression

The ability of different phosphatidylcholine (PC) species to inhibit cytokine-induced expression of vascular cell adhesion molecule 1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) was investigated. PC species containing palmitoylin the sn-1 position and palmitoyl- (DPPC), arachidonyl- (PAPC), linoleoyl- (PLPC) or oleoyl- (POPC) in the sn-2 position were compared. These PC species were studied as components of reconstituted high density lipoproteins (rHDL) (containing apolipoprotein A-I apoA-I as the sole protein) or as small unilamellar vesicles (SUVs). The rHDL containing PLPC and PAPC inhibited VCAM-1 expression in activated HUVECs by 95 and 70%, respectively, at an apoA-I concentration of 16 μm. At this concentration of apoA-I, POPC rHDL inhibited by only 16% and DPPC rHDL did not inhibit at all. These differences could not be explained by differential binding of the rHDL to HUVECs. The same hierarchy of inhibitory activity was observed when these PC species were presented to the cells as SUVs but only when the SUVs also contained an antioxidant. It was concluded that rHDL PC is responsible for their inhibitory activity and that this varies widely with different PC species. —Baker, P. W., K-A. Rye, J. R. Gable, M. A. Vadas, and P. J. Barter. Phospholipid composition of reconstituted high density lipoproteins influences their ability to inhibit endothelial cell adhesion molecule expression. J. Lipid Res. 2000. 41: 1261–1267. The ability of different phosphatidylcholine (PC) species to inhibit cytokine-induced expression of vascular cell adhesion molecule 1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) was investigated. PC species containing palmitoylin the sn-1 position and palmitoyl- (DPPC), arachidonyl- (PAPC), linoleoyl- (PLPC) or oleoyl- (POPC) in the sn-2 position were compared. These PC species were studied as components of reconstituted high density lipoproteins (rHDL) (containing apolipoprotein A-I apoA-I as the sole protein) or as small unilamellar vesicles (SUVs). The rHDL containing PLPC and PAPC inhibited VCAM-1 expression in activated HUVECs by 95 and 70%, respectively, at an apoA-I concentration of 16 μm. At this concentration of apoA-I, POPC rHDL inhibited by only 16% and DPPC rHDL did not inhibit at all. These differences could not be explained by differential binding of the rHDL to HUVECs. The same hierarchy of inhibitory activity was observed when these PC species were presented to the cells as SUVs but only when the SUVs also contained an antioxidant. It was concluded that rHDL PC is responsible for their inhibitory activity and that this varies widely with different PC species. —Baker, P. W., K-A. Rye, J. R. Gable, M. A. Vadas, and P. J. Barter. Phospholipid composition of reconstituted high density lipoproteins influences their ability to inhibit endothelial cell adhesion molecule expression. J. Lipid Res. 2000. 41: 1261–1267. Human high density lipoproteins (HDL) inhibit the cytokine-induced expression of adhesion molecules in endothelial cells (1Cockerill G.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. High-density lipoproteins inhibit cytokine-induced expression of endothelial cell adhesion molecules.Arterioscler. Thromb. Vasc. Biol. 1995; 15: 1987-1994Google Scholar) in a process that may contribute to their antiatherogenicity. This inhibition is concentration dependent within the physiological range of HDL concentrations, although at any given concentration the extent of inhibition varies widely between preparations of HDL isolated from different human subjects (2Ashby D.T. Rye K-A. Clay M.A. Vadas M.A. Gamble J.R. Barter P.J. Factors influencing the ability of high-density lipoproteins to inhibit the expression of vascular cell adhesion molecule-1 in endothelial cells.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1450-1455Google Scholar). The reason for this intersubject variation is not known. The demonstration in a mouse model that HDL inhibits vascular cell adhesion molecule 1 (VCAM-1) expression in endothelial cells in vivo (3Dimayuga P. Zhu J. Oguchi S. Chyu K-Y. Xu Z-O.H. Yano J. Shah P.K. Nillson J. Cercek B. Reconstituted HDL containing human apolipoprotein A-I reduces VCAM-1 expression and neointima formation following periadventitial cuff-induced carotid injury in apoE null mice.Biochem. Biophys. Res. Comm. 1999; 264: 465-468Google Scholar) highlights the importance of understanding more about this activity of HDL. In earlier studies of HDL-mediated inhibition of the tumor necrosis factor α (TNF-α)-induced expression of VCAM-1 in human umbilical vein endothelial cells (HUVECs), we demonstrated that i) the inhibitory activity of both HDL (2Ashby D.T. Rye K-A. Clay M.A. Vadas M.A. Gamble J.R. Barter P.J. Factors influencing the ability of high-density lipoproteins to inhibit the expression of vascular cell adhesion molecule-1 in endothelial cells.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1450-1455Google Scholar) and reconstituted HDL (rHDL) (4Baker P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar) is unaffected by replacing all of the HDL apolipoprotein (apo) A-I with apoA-II; ii) both spherical and discoidal reconstituted HDL (rHDL) possess inhibitory activity (4Baker P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar); and iii) neither the size nor the cholesteryl ester and triglyceride content of rHDL has any effect on their inhibitory activity (4Baker P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar). In contrast to these earlier negative findings, we now report that the inhibitory activity of discoidal rHDL is greatly influenced by its phospholipid composition. Specifically, of three of the most abundant phospholipids in human HDL, 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine (PLPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphocholine (PAPC), rHDL containing PLPC or PAPC have a much greater inhibitory activity than those containing POPC. Discoidal rHDL were prepared by the cholate dialysis method precisely as described (5Matz C.E. Jonas A. Micellar complexes of human apolipoprotein A-I with phosphatidylcholines and cholesterol prepared from cholate-lipid dispersions.J. Biol. Chem. 1982; 257: 4535-4540Google Scholar). Their sole lipid component was 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), PAPC, PLPC, or POPC while their sole protein component was apolipoprotein A-I (apoA-I) (molar ratio of PC to apoA-I of 100:1). Particles were also prepared with apoA-I and mixtures of both PLPC and POPC (molar ratio of PLPC to POPC to apoA-I of 90:10:1, 70:30:1, and 50:50:1). For lipid uptake studies rHDL were prepared with apoA-I and PLPC or POPC labeled with 14C in the sn-2 acyl group. Some preparations of rHDL also contained the antioxidant, butylated hydroxytoluene (BHT; molar ratio of PC to BHT to apoA-I of 100:10:1). For binding experiments, apoA-I was labeled with 125I, using Iodobeads as described by the manufacturer (Pierce, Rockville, IL). Iodinated apoA-I was then used to prepare rHDL. Phospholipids were purchased from Sigma (St. Louis, MO). The apoA-I was purified from human HDL as described previously (4Baker P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar). After preparation all rHDL were extensively dialyzed (5 times, 1 L each time) against nitrogen-purged 10 mm Tris-buffered saline (TBS, pH 7.4) containing 150 mm NaCl, 0.03% (w/v) EDTA-Na2, 0.006% (w/v) NaN3, and 0.2% (w/v) Chelex (Bio-Rad, Hercules, CA). After dialysis the samples were protected from light, stored under nitrogen, and used within 1 week of preparation. Before addition to HUVECs, the rHDL were dialyzed over 24 h against endotoxin-free phosphate-buffered saline (PBS) (three times, 1 L each time). The size distribution of the rHDL was determined by gradient gel electrophoresis (6Rye K-A. Interaction of the high density lipoprotein conversion factor with recombinant discoidal complexes of egg phosphatidylcholine, free cholesterol, and apolipoprotein A-I.J. Lipid Res. 1989; 30: 335-346Google Scholar). The number of molecules of apoA-I per rHDL particle was determined by cross-linking (7Rye K-A. Garrety K.H. Barter P.J. Preparation and characterization of spheroidal, reconstituted high-density lipoproteins with apolipoprotein A-I only or with apolipoprotein A-I and A-II.Biochim. Biophys. Acta. 1993; 1167: 316-325Google Scholar). Small unilamellar vesicles (SUVs) containing PAPC, PLPC, or POPC, and BHT (molar ratio of PC to BHT, 10:1), were prepared in PBS precisely as described by Jonas (8Jonas A. Reconstitution of high-density lipoproteins.Methods Enzymol. 1986; 128: 553-582Google Scholar). In some experiments the SUVs were prepared without BHT. HUVECs were isolated and cultured as described previously (4Baker P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar). Briefly, confluent preparations of HUVECs (passage 2–4) were washed with 10 mm EDTA-Na2 (5 mL) in PBS, trypsinised and replated onto 24-well gelatin-coated plates at a density of 3 × 105 cells/mL (500 μl/well). After a 5-h reattachment period a portion of the medium (100 μL) was removed and replaced with PBS alone (100 μL) or with rHDL or SUVs in PBS (100 μL). The cells were then preincubated for 16 h (unless otherwise indicated) before being activated with TNF-α or interleukin 1 (IL-1) (100 U/mL). In some experiments (where indicated) the medium containing the rHDL was removed, the cells were washed with PBS, and fresh medium (not containing rHDL) was replaced before addition of cytokines. Five hours after addition of cytokine the cell surface expression of VCAM-1 was measured by flow cytometry as described (4Baker P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar). HUVECs were plated onto 6-well gelatin-coated plates at a density of 3 × 105 cells/mL (2.5 mL/well). Binding of rHDL containing iodinated apoA-I to HUVECs, in the absence or presence of unlabeled rHDL, was determined after 2 h at 4°C as described by Vadiveloo and Fidge (9Vadiveloo P.K. Fidge N.H. Studies on the interaction between apolipoprotein A-II-enriched HDL3 and cultured bovine aortic endothelial (BAE) cells.Biochim. Biophys. Acta. 1990; 1045: 135-141Google Scholar). Binding of labeled rHDL was determined at an apoA-I concentration of 500 nm, consistent with the reported affinity of HDL for endothelial membranes (9Vadiveloo P.K. Fidge N.H. Studies on the interaction between apolipoprotein A-II-enriched HDL3 and cultured bovine aortic endothelial (BAE) cells.Biochim. Biophys. Acta. 1990; 1045: 135-141Google Scholar, 10Vadiveloo P.K. Fidge N.H. The role of apolipoproteins AI and AII in binding of high-density lipoprotein3 to membranes derived from bovine aortic endothelial cells.Biochem. J. 1992; 284: 145-151Google Scholar, 11Fidge N.H. High density lipoprotein receptors, binding proteins, and ligands.J. Lipid Res. 1999; 40: 187-201Google Scholar). Specific binding of labeled rHDL was calculated by subtracting nonspecific binding of labeled rHDL (determined in the presence of a 50-fold excess of unlabeled rHDL) from total binding of labeled rHDL. Uptake of 14C by HUVECs from rHDL containing PLPC or POPC labeled with 14C in the sn-2 acyl group was determined after a 16-h incubation of the cells at 37 °C with rHDL at an apoA-I concentration of 16 μm. After incubation the cells were washed extensively with PBS, harvested into a minimal volume of PBS, and sonicated. Liquid scintillation counting of an aliquot of the sonicated cells was used to determine the incorporation of 14C into the cells. The amount of 14C bound to the cell surface, a possible confounding factor in determining the cellular uptake of 14C, was determined after a 2-h incubation at 4°C. ANOVA with was with the in by all within a as a group. was determined at the that Discoidal rHDL were prepared by apoA-I to a number of different PC species. The rHDL containing PLPC, or POPC were in with of or nm, In each of these preparations were molecules of apoA-I per The rHDL containing PAPC were of with from to most of the PAPC rHDL contained molecules of apoA-I per about contained three or molecules of apoA-I per The molar ratio of PC to apoA-I was about in all rHDL HUVECs were preincubated for 16 h with rHDL containing PAPC, PLPC, or POPC before being activated with with PLPC or PAPC rHDL to a in the expression of VCAM-1 In with POPC rHDL effect on VCAM-1 expression. At an apoA-I concentration of 16 the inhibition by PLPC, PAPC, and POPC rHDL was and determine the extent of inhibition was influenced by the of the HUVECs were preincubated with rHDL containing PLPC or POPC for 1 h or 16 h before with After 1 h of at an apoA-I concentration of 16 PLPC rHDL inhibited VCAM-1 expression by when the was to 16 the inhibition was At the same concentration of apoA-I, POPC rHDL inhibited VCAM-1 expression by 16% when preincubated with the cells for 16 h but did not inhibit at all when preincubated for only 1 h not In all the experiments described the rHDL were in the medium at the of addition of the rHDL in the medium for the h the incubation was and VCAM-1 expression was In studies with HDL, we have that the inhibition of VCAM-1 HUVECs the HDL were removed from the medium before of the cells with TNF-α (1Cockerill G.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. High-density lipoproteins inhibit cytokine-induced expression of endothelial cell adhesion molecules.Arterioscler. Thromb. Vasc. Biol. 1995; 15: 1987-1994Google Scholar, D.T. Rye K-A. Clay M.A. Vadas M.A. Gamble J.R. Barter P.J. Factors influencing the ability of high-density lipoproteins to inhibit the expression of vascular cell adhesion molecule-1 in endothelial cells.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1450-1455Google Scholar, P. Vadas M.A. Rye K-A. Barter P.J. Gamble J.R. High-density lipoproteins (HDL) the Biol. Chem. 1999; Scholar). studies to determine this also to discoidal rHDL the hierarchy of inhibitory observed with rHDL containing different PC species These studies were not only with rHDL containing PLPC, PAPC, or POPC as in 1 but also with rHDL containing HUVECs were preincubated for 16 h with these rHDL preparations before the medium containing the rHDL was removed, the cells were washed with PBS, and fresh medium (not containing rHDL) was The cells were then activated with TNF-α and the expression of VCAM-1 determined h being removed before the cells were rHDL containing PLPC or PAPC inhibited VCAM-1 expression in a at an apoA-I concentration of 16 the inhibition by PLPC and PAPC rHDL was and The rHDL containing POPC minimal inhibitory activity and those containing DPPC did not inhibit at all Studies were to determine the inhibitory of rHDL containing PLPC or POPC were to differences in their binding to HUVECs. Binding of rHDL to HUVECs was in the apoA-I was labeled with The activity of the rHDL apoA-I was 150 Specific binding of POPC rHDL and PLPC rHDL to cells was with 0.03% of the rHDL being bound to the cell binding studies of labeled POPC rHDL in the presence of an amount of unlabeled PLPC rHDL and demonstrated that each rHDL preparation a affinity for the cell After incubation all the apoA-I was in the demonstrated that rHDL containing PLPC or POPC with affinity to the surface of HUVECs, studies were to determine the extent to these cells 14C from rHDL containing PLPC or POPC labeled with 14C in the sn-2 acyl group. The activity of the rHDL PC was After a 16-h incubation at the cells were to have of the 14C contained in the rHDL PC was in the uptake of 14C from rHDL containing POPC or PLPC of the phospholipid to the cells was in the medium after the incubation was at were with the between and 0.03% of the observed differences in the ability of discoidal rHDL containing PLPC or POPC to inhibit endothelial cell VCAM-1 studies were to the of between these PC species. In these studies discoidal rHDL were prepared with apoA-I and mixtures of PLPC and POPC. The molar of PLPC to POPC in these mixtures were and a molar ratio of PC to apoA-I of about and of with that from when the contained PLPC to when the contained POPC. The rHDL containing PLPC inhibited VCAM-1 expression in a with the inhibition at an apoA-I concentration of 16 while the rHDL containing POPC minimal inhibition at this of apoA-I of of the rHDL PLPC with POPC the inhibition from to at an apoA-I concentration of 16 μm. of of the rHDL PLPC with POPC the inhibition to while of the rHDL PLPC with POPC the inhibition to Studies were to determine the of discoidal rHDL could be by SUVs PAPC, PLPC, or POPC. PAPC and PLPC SUVs prepared without BHT were to HUVECs as by to their on adhesion molecule expression. In PAPC and PLPC SUVs containing BHT were not after 16 h of and inhibited the expression of VCAM-1 in a to that of PLPC and PAPC rHDL POPC with or without BHT, were not to in neither did inhibit VCAM-1 expression with PLPC and PAPC rHDL, the inhibition by PAPC and PLPC SUVs was the SUVs were of the cells with cytokine or removed to of VCAM-1 expression in HUVECs by the cells with rHDL or SUVs containing different PC species. Discoidal rHDL were prepared with PLPC or POPC and apoA-I at a molar ratio of PC to apoA-I of as described in and SUVs were prepared with PLPC or POPC as the sole lipid and BHT as an at a molar ratio of PC to BHT of as described in and HUVECs were preincubated with the different preparations of rHDL or SUVs for 16 h before being activated with The medium containing the rHDL or SUVs was removed before with VCAM-1 expression was determined h after with as to a in inhibitory activity with POPC rHDL or POPC SUVs In all the experiments the HUVECs were activated with experiments were to determine the inhibitory of rHDL and SUVs containing PLPC or POPC were also when than TNF-α was used to the cells. In these experiments rHDL or SUVs (containing were preincubated with HUVECs for 16 The rHDL and SUVs were then removed, fresh medium (not containing rHDL or was and the cells were activated with PLPC, as a component of rHDL or inhibited the expression of VCAM-1 in HUVECs in a to that observed when the cells were activated by with the with POPC to effect on the expression of as a component of rHDL or SUVs These studies for the that three of the more abundant PC species in human HDL, PAPC, PLPC, and POPC P. species of phosphatidylcholine in effect of Biophys. Acta. 1989; Scholar, of human species of phosphatidylcholine in Biophys. Acta. in their to inhibit the expression of VCAM-1 in HUVECs. These differences were observed the PC species were presented to the cells as components of discoidal rHDL or as SUVs and could not be explained by differences in rHDL binding to the cells or the uptake of rHDL PC by the cells. PAPC and PLPC were to HUVECs were components of rHDL in were to apoA-I or were components of SUVs that also the BHT. This is consistent with that apoA-I has B. P.K. Rye K-A. R. of high-density for of lipid by of apolipoproteins AI and Biol. Chem. 1998; Scholar). It may also density lipoproteins more than the in HDL M. M. inhibits high-density lipoprotein and its possible role for 1998; not inhibit adhesion molecule expression Zhu of vascular cell adhesion molecule-1 by Scholar, density lipoprotein and its vascular cell adhesion molecule-1 expression in human vascular endothelial cells.J. 1995; Scholar). have reported that both HDL and rHDL inhibit endothelial P. Vadas M.A. Rye K-A. Barter P.J. Gamble J.R. High-density lipoproteins (HDL) the Biol. Chem. 1999; Scholar). is an that a in the by endothelial cell VCAM-1 and expression P. Gamble J.R. Rye K-A. P. Barter P.J. Vadas M.A. necrosis adhesion molecule expression the 1998; Scholar). The by HDL with the cell to this inhibition is not known. is that not by HDL with the binding of TNF-α to the cell surface P. Vadas M.A. Rye K-A. Barter P.J. Gamble J.R. High-density lipoproteins (HDL) the Biol. Chem. 1999; Scholar). This is by the in the that the inhibitory activity of both rHDL and SUVs when were removed before the cells were activated with TNF-α or The for the inhibitory of rHDL and SUVs containing different PC species is not known. of the the has of the phospholipid in human HDL is with PLPC for about of the PC P. species of phosphatidylcholine in effect of Biophys. Acta. 1989; Scholar, of human species of phosphatidylcholine in Biophys. Acta. Scholar). The importance of the composition of phospholipids that of HDL phospholipids P. species of phosphatidylcholine in effect of Biophys. Acta. 1989; Scholar, of human species of phosphatidylcholine in Biophys. Acta. has in studies in the composition of phospholipids is of the of J. of phospholipid and cholesterol ester composition to carotid the in J. Scholar, M. for in Scholar, S. composition of J. 1982; Scholar, in with Scholar). It be of to determine inhibitory of HDL isolated from different human subjects (2Ashby D.T. Rye K-A. Clay M.A. Vadas M.A. Gamble J.R. Barter P.J. Factors influencing the ability of high-density lipoproteins to inhibit the expression of vascular cell adhesion molecule-1 in endothelial cells.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1450-1455Google Scholar) be explained by in the composition of HDL It also be differences in phospholipid composition the inhibitory activity of HDL3 with that of (2Ashby D.T. Rye K-A. Clay M.A. Vadas M.A. Gamble J.R. Barter P.J. Factors influencing the ability of high-density lipoproteins to inhibit the expression of vascular cell adhesion molecule-1 in endothelial cells.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1450-1455Google Scholar). the different PC species were presented to the cells as components of the hierarchy of inhibitory was the same as that observed when of rHDL. This the that PC may be the component of HDL responsible for its inhibitory The that these PC species as components of SUVs only in the presence of an that the inhibitory activity of the PC in HDL may on being protected by the of these lipoproteins B. P.K. Rye K-A. R. of high-density for of lipid by of apolipoproteins AI and Biol. Chem. 1998; Scholar, M. M. inhibits high-density lipoprotein and its possible role for 1998; Scholar, M. effect of high-density lipoprotein of the activity of density 1995; Scholar). The cytokine-induced expression of endothelial cell VCAM-1 is also inhibited by R. P. of endothelial adhesion molecules by Scholar, R. M.A. P. for inhibition of cytokine-induced endothelial by Lipid Res. 1998; Scholar). with the inhibition by phospholipids in the the inhibition by is to that of R. M.A. P. for inhibition of cytokine-induced endothelial by Lipid Res. 1998; Scholar). differences between the inhibition by and that by the PC with HDL. For is of a with the inhibition by HDL (1Cockerill G.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. High-density lipoproteins inhibit cytokine-induced expression of endothelial cell adhesion molecules.Arterioscler. Thromb. Vasc. Biol. 1995; 15: 1987-1994Google Scholar) or rHDL, the inhibition by only after a of about h R. P. of endothelial adhesion molecules by Scholar). In inhibition of VCAM-1 expression by for h R. P. of endothelial adhesion molecules by Scholar, R. M.A. P. for inhibition of cytokine-induced endothelial by Lipid Res. 1998; Scholar) with 16 h or in the of HDL or rHDL (1Cockerill G.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. High-density lipoproteins inhibit cytokine-induced expression of endothelial cell adhesion molecules.Arterioscler. Thromb. Vasc. Biol. 1995; 15: 1987-1994Google Scholar, D.T. Rye K-A. Clay M.A. Vadas M.A. Gamble J.R. Barter P.J. Factors influencing the ability of high-density lipoproteins to inhibit the expression of vascular cell adhesion molecule-1 in endothelial cells.Arterioscler. Thromb. Vasc. Biol. 1998; 18: 1450-1455Google Scholar, P.W. Rye K-A. Gamble J.R. Vadas M.A. Barter P.J. Ability of reconstituted high density lipoproteins to inhibit cytokine-induced expression of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells.J. Lipid Res. 1999; 40: 1-9Google Scholar). the for the inhibitory of that of their incorporation into cellular R. P. of endothelial adhesion molecules by Scholar). that the importance of HDL in this process to their ability to PC in an in is protected against to being to endothelial cells. The of these to the ability of HDL to against to be the of in vivo studies (3Dimayuga P. Zhu J. Oguchi S. Chyu K-Y. Xu Z-O.H. Yano J. Shah P.K. Nillson J. Cercek B. Reconstituted HDL containing human apolipoprotein A-I reduces VCAM-1 expression and neointima formation following periadventitial cuff-induced carotid injury in apoE null mice.Biochem. Biophys. Res. Comm. 1999; 264: 465-468Google Scholar, G.W. reconstituted high-density lipoprotein (HDL) discoidal the expression of in in a model of in 1999; Scholar, B. P. adhesion molecule expression and in apoE 1999; Scholar, M. inhibits cell formation in after to 1999; studies have that HDL inhibit endothelial cell adhesion molecule expression in vivo (3Dimayuga P. Zhu J. Oguchi S. Chyu K-Y. Xu Z-O.H. Yano J. Shah P.K. Nillson J. Cercek B. Reconstituted HDL containing human apolipoprotein A-I reduces VCAM-1 expression and neointima formation following periadventitial cuff-induced carotid injury in apoE null mice.Biochem. Biophys. Res. Comm. 1999; 264: 465-468Google Scholar, G.W. reconstituted high-density lipoprotein (HDL) discoidal the expression of in in a model of in 1999; Scholar, B. P. adhesion molecule expression and in apoE 1999; Scholar). the extent that this of HDL is the studies that the phospholipid composition may be of greater importance than previously and for and Fidge for the of apoA-I and binding also to for the preparation of this This was by from the and of and the of