Published online before print October 13, 2005, doi: 10.1161/01.RES.0000190634.60042.cb
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© 2005 American Heart Association, Inc.
Integrative Physiology |
Effects of D-4F on Vasodilation and Vessel Wall Thickness in Hypercholesterolemic LDL Receptor–Null and LDL Receptor/Apolipoprotein A-I Double-Knockout Mice on Western Diet
From the Departments of Surgery, Division of Pediatric Surgery (J.O., J.W., H.X., Z.O., D.W.J., P.S., J.C.D., S.K., K.T.O., K.A.P.), Children’s Research Institute (J.O., J.W., H.X., Z.O., P.S., J.C.D., K.T.O., K.A.P.), and Cardiovascular Center (J.O., J.W., H.X., Z.O., K.T.O., K.A.P.), Medical College of Wisconsin, Milwaukee; Guangzhou Institute of Respiratory Disease, Division of Cardiothoracic Surgery (J.O.), and Department of Medicine, Division of Cardiology (Z.O.), The First Affiliated Hospital of Guangzhou Medical College, China; Department of Pathology (M.G.S.-T.), Wake Forest University School of Medicine, Winston-Salem, NC.
Correspondence to Kirkwood A. Pritchard, Jr, PhD, Medical College of Wisconsin, Pediatric Surgery, CRI, CVC, M-4060, 8701 Watertown Plank Rd, Milwaukee, WI 53226. E-mail kpritch{at}mcw.edu
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Abstract |
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Previously we showed L-4F, a novel apolipoprotein A-I (apoA-I) mimetic, improved vasodilation in 2 dissimilar models of vascular disease: hypercholesterolemic LDL receptor–null (Ldlr–/–) mice and transgenic sickle cell disease mice. Here we determine the mechanisms by which D-4F improves vasodilation and arterial wall thickness in hypercholesterolemic Ldlr–/– mice and Ldlr–/–/apoA-I null (apoA-I–/–), double-knockout mice. Ldlr–/– and Ldlr–/–/apoA-I–/– mice were fed Western diet (WD) with and without D-4F. Oral D-4F restored endothelium- and endothelial NO synthase (eNOS)-dependent vasodilation in direct relationship to duration of treatments and reduced wall thickness in as little as 2 weeks in vessels with preexisting disease in Ldlr–/– mice. D-4F had no effect on total or HDL cholesterol concentrations but reduced proinflammatory HDL levels. D-4F had no effect on plasma myeloperoxidase concentrations but reduced myeloperoxidase association with apoA-I as well as 3-nitrotyrosine in apoA-I. D-4F increased endothelium- and eNOS-dependent vasodilation in Ldlr–/–/apoA-I–/– mice but did not reduce wall thickness as it had in Ldlr–/– mice. Vascular endothelial cells were treated with 22(R)-hydroxycholesterol with and without L-4F. 22(R)-Hydroxycholesterol decreased NO (·NO) and increased superoxide anion (O2·–) production and increased ATP-binding cassette transporter-1 and collagen expression. L-4F restored ·NO and O2·– balance, had little effect on ATP-binding cassette transporter-1 expression, but reduced collagen expression. These data demonstrate that although D-4F restores vascular endothelial cell and eNOS function to increase vasodilation, HDL containing apoA-I, or at least some critical concentration of the antiatherogenic lipoprotein, is required for D-4F to decrease vessel wall thickness.
Key Words: cardiovascular diseases • hypercholesterolemia • lipoproteins • nitric oxide synthase • vasodilation
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Introduction |
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Endothelial cells play an important role in maintaining vascular health. One of the earliest physiological and most sensitive changes in hypercholesterolemia is loss of endothelium- and endothelial NO synthase (eNOS)-dependent vasodilation, which appears to occur before structural changes in the vessel wall.1,2 In a prospective human study, angiography was used to observe impaired endothelium-dependent vasodilation in coronary arteries and was found to be a strong prognostic indicator of vascular pathology.3 Such findings,3 as well as those from others,4,5 support the concept that endothelium-dependent vasodilation provides important insights into the atherogenic state of the vessel wall.
We previously reported L-4F, when administered by IP injection, increased eNOS-dependent vasodilation of small arteries from hypercholesterolemic Ldlr–/– mice and from transgenic sickle cell mice.6 D-4F is the same as L-4F, except it is synthesized from D-amino acids. In the D conformation, 4F is resistant to metabolism compared with 4F synthesized from L-amino acids, which is rapidly degraded after oral administration.8 Oral D-4F reduced lesions in Ldlr–/– mice fed WD by more than 79% by restoring HDL function without significantly altering cholesterol or HDL cholesterol levels.7 Interestingly, D-4F also reduced lesions in apoE–/– mice, which were hypercholesterolemic from birth.7 However, to date, no studies have been performed to determine whether oral D-4F also restores vasodilation in hypercholesterolemic mice.
D-4F is believed to protect vascular function by binding proinflammatory lipids.8 Proinflammatory oxysterols, such as hydroxycholesterol increase apoptosis of endothelial cells,9,10 whereas other proinflammatory lipids have been shown to increase susceptibility of HDL to oxidation.11 Previous studies by Reddy et al12 revealed 22(R)-hydroxycholesterol (22-OHC), 1 of several forms of oxysterols found in atherosclerotic lesions,13 increases ATP-binding cassette transporter-1 (ABCA-1) expression. Endothelial cells typically maintain an antioxidant phenotype until exposed to LDL containing a critical threshold of lipid peroxides, at which point they are converted into a prooxidant phenotype that promotes LDL oxidation.14 Likewise, when endothelial cells are exposed to 22-OHC, they become proinflammatory and promote oxidation of LDL via ABCA-1 transportation of oxidized phospholipids from the endothelial cell to the LDL particle.12 As 22-OHC does not contain a hydroperoxide for initiating or propagating oxidation, the mechanism by which 22-OHC–treated endothelial cells take on a proinflammatory phenotype is likely attributable to altered cell signaling more than lipid peroxidation.
Recently, it was reported myeloperoxidase (MPO) binds to HDL and subsequently increases nitration of apoA-I, which correlates with a decrease in the ability of HDL to promote cholesterol efflux from cholesterol-loaded macrophages.15 Although the role of MPO in atherosclerosis in mice is controversial,16,17 in murine studies where neutrophils are clearly involved, MPO has been implicated as a mechanism of lipid peroxidation and vascular endothelial cell dysfunction18 in ways that are consistent with how MPO is believed to promote atherosclerosis in humans.19,20
The objectives here were to determine (1) mechanisms by which D-4F improves vasodilation in murine models of hypercholesterolemia; (2) whether increases in vasodilation correlate with changes in vessel wall architecture; (3) mechanisms by which D-4F protects HDL against oxidative stress; and (4) mechanisms by which D-4F reduces vessel wall thickness. Our findings indicate D-4F improves vasodilation in hypercholesterolemic Ldlr–/– mice by increasing eNOS function but reduces vessel wall thickness in hypercholesterolemic Ldlr–/– mice by an HDL-dependent mechanism.
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Materials and Methods |
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Mice
Male Ldlr–/– mice (6 to 8 weeks) on a C57BL/6 background were from Jackson Laboratory (Bar Harbor, Me) or from a colony established at the Medical College of Wisconsin. Ldlr–/– mice were maintained on WD, a high-fat, cholesterol diet (No. 88137) from Teklad (Madison, Wis) and given D-4F in drinking water (50 µg/mL, &2.5 mL/d per mouse) or by IP injection (1 mg/kg per day). Feeding and D-4F schedules for time-dependent studies are shown in Figure 1. Male C57BL/6 mice from Jackson Laboratory were maintained on laboratory chow. Male Ldlr–/–/apoA-I–/– double-knockout mice were from a colony maintained at Wake Forest University School of Medicine.21
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D-4F and L-4F
D-4F and L-4F (Ac-DWFKAFYDKVAEKFKEAFNH2) were synthesized as described.6,7
Vasodilation
Vasodilation of pressurized facialis arteries (180 to 280 µm) was determined as before.6
Wall Thickness
At the end of incubation with papaverine (10–4 mol/L, 4 minutes),6 an index of wall thickness was calculated using the following formula: ([outside diameter–inside diameter]/2)/outside diameter.
Plasma Cholesterol, HDL Cholesterol, and Proinflammatory HDL
Plasma cholesterol and HDL cholesterol were determined by cholesterol oxidase/esterase assays using Cholesterol E and HDL Cholesterol E kits, respectively, from Wako Chemicals USA Inc (Richmond, Va). After quantification of HDL, proinflammatory HDL was determined.
The proinflammatory HDL assay is based on the observation that relative rates of dichlorofluorescein (DCF) fluorescence are proportional to the levels of seeding molecules of lipid hydroperoxides in HDL.11 Briefly, 1 µg of HDL cholesterol was incubated with CuCl2 (5 µmol/L, final concentration) for 1 hour using a 384-well microtiter plate from MJ Research Inc (Waltham, Mass). After incubation, 1 µL of DCF solution (2 mg/mL) was added to the HDL-Cu2+ mixture in a total volume of 30 µL. Rates of fluorescence (excitation, 485 nm; emission, 530 nm) were determined on a LJL Biosystem Analyst HT from Molecular Devices Corp (Sunnyvale, Calif) over the next 2 hours at 30-minute intervals.
Effects of 22-OHC on Vascular Endothelial Cell ·NO and O2·– Balance and Expression of ABCA-1 and Collagen
Confluent bovine aortic endothelial cells (EC) were incubated with 22-OHC (25 µmol/L; H9384, Sigma) with and without L-4F (10 µg/mL) overnight and then prepared for (1) A23187 stimulated ·NO and O2·– production as described,22,23 (2) Western blot analysis of ABCA-1 as described,12 or (3) measurements of collagen synthesis based on collagenase-sensitive [3H]proline incorporation as described by Siwik et al.24
MPO/ApoA-I and 3-Nitrotyrosine/ApoA-I
MPO association with apoA-I was determined by Western blot analysis of apoA-I immunoprecipitates (goat anti-mouse apoA-I, K59166G, Biodesign, Saco, Me) using a rabbit anti-mouse MPO antibody (07-009, Upstate Biomedical, Charlottesville, Va). 3-Nitrotyrosine (3NT) in apoA-I was determined by Western blot analysis of apoA-I immunoprecipitates using mouse anti-nitrotyrosine (05-233, Upstate Biomedical) and anti–apoA-I (K59166G, Biodesign) as primary antibodies and the appropriate horseradish peroxidase–conjugated secondary antibodies as described.15 In both cases, apoA-I was detected by Western blot analysis using a rabbit anti-mouse apoA-I antibody (K23001R, Biodesign).
Statistical Analysis
Comparisons between 2 groups were by the Student t test. Comparisons between multiple groups were by 1-way ANOVA with Bonferroni correction for multiple groups. Comparisons between vasodilation curves were by 2-way ANOVA. Minimum levels of significance were set at P<0.05. Statistical analysis was performed using Prism 3 from GraphPad Software Inc.
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Results |
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After 6 weeks on WD, vasodilation of facialis arteries from WD-fed Ldlr–/– mice was reduced compared with vasodilation in C57BL/6 mice and Ldlr–/– mice fed standard laboratory chow (Figure 2A). Time-dependent studies revealed D-4F improved vasodilation in Ldlr–/– mice fed WD in direct relation to duration of D-4F treatments (Figure 2B). The longer WD-fed Ldlr–/– mice were treated with D-4F, the more vasodilation was increased. Vasodilation in WD-fed Ldlr–/– mice treated with D-4F for 6 weeks (group II) was increased even beyond that observed in chow-fed Ldlr–/– mice but not in C57BL/6 mice (Figure 2A). As before, NG-nitro-L-arginine methyl ester (L-NAME) essentially ablated acetylcholine (ACh)-induced vasodilation in the pressurized vessels from the experimental groups (I through IV) and papaverine dilated these vessels to &98% of their maximal diameter, confirming that the loss in eNOS-dependent vasodilation was caused by endothelial cell dysfunction, not vascular smooth muscle cell dysfunction (data not shown).6
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To confirm vessels in Ldlr–/– mice from group IV had preexisting disease, before D-4F treatments, we fed another set of Ldlr–/– mice WD. Vasodilation was impaired in group V mice after 4 weeks of WD compared with vasodilation in group VI and group VII (Figure 2C). With just 2 weeks of oral D-4F treatments, concurrently with WD, vasodilation in group VI was improved beyond levels in Ldlr–/– mice that were fed laboratory chow (group VII) (Figure 2C).
As a nonbiased measure of arterial structure, we simply determined the effects of D-4F on arterial wall thickening induced by WD by measuring inside and outside diameters of arteries after incubation with papaverine to eliminate any contribution of endothelial cell function/dysfunction to vessel diameter. Wall thickness in Ldlr–/– mice fed WD was markedly increased compared with the wall thickness in C57BL/6 or Ldlr–/– mice fed laboratory chow diet (Figure 3A). At all time points tested, oral D-4F reduced wall thickness in Ldlr–/– mice fed WD regardless of duration of oral D-4F treatments (Figure 3B). Wall thickness data confirmed that the vessels in Ldlr–/– mice from group IV had preexisting disease at 4 weeks of WD, before D-4F treatments (Figure 3C). More importantly, treating WD-fed Ldlr–/– mice with D-4F for only 2 weeks, concurrently with WD, reduced wall thickness to essentially the same thickness as Ldlr–/– mice fed laboratory chow (Figure 3C).
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D-4F had no effect on total cholesterol or HDL cholesterol in Ldlr–/– mice fed WD (Table 1). Although there was a tendency for HDL levels to be higher in Ldlr–/– mice fed WD and treated with D-4F, statistical significance was not achieved. In contrast to D-4F effects on cholesterol, proinflammatory HDL levels were significantly decreased.
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To determine mechanisms by which proinflammatory lipids impair endothelial cell function, we treated endothelial cell cultures with 22-OHC with and without L-4F. 22-OHC decreased stimulated ·NO production (Figure 4A) and increased stimulated O2·– generation (Figure 4B). L-4F restored stimulated ·NO production (Figure 4A) while decreasing stimulated O2·– production in the cultures treated with 22-OHC (Figure 4B). Western blot analysis confirms 22-OHC increased ABCA-1 expression by a liver X receptor–dependent mechanism, as was shown earlier by Reddy et al,12 which was unaltered by L-4F. Next, we examined effects of 22-OHC and L-4F on collagen production as a means of determining whether or not this oxysterol and apoA-I mimetic modulated endothelial cell matrix production. 22-OHC increased collagen synthesis, which L-4F reduced to control levels (Figure 4D).
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Plasma measurements of MPO revealed that D-4F had no effect on total MPO concentrations in Ldlr–/– mice fed WD (Figure 5A). However, immunoblotting for MPO and 3NT in apoA-I of apoA-I immunoprecipitates from these mice revealed D-4F decreased both MPO association with and 3NT in apoA-I (Figure 5B and 5C). Immunoblots of apoA-I immunoprecipitates from C57BL/6 plasma that was treated with D-4F in vitro revealed D-4F had no direct effect on MPO association with apoA-I (Figure 5D).
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Next, we fed Ldlr–/–/apoA-I–/– mice WD and treated them with and without D-4F to determine the extent to which D-4F required HDL to improve vasodilation and/or reduce vessel wall thickness. Although ACh promoted a moderate increase in vasodilation in vessels from Ldlr–/–/apoA-I–/– mice fed WD, the upward slope of the ACh dose response curves in the presence of L-NAME revealed only a small portion of endothelium-dependent vasodilation in these mice was actually mediated by eNOS (Figure 6A). Comparing hatched regions in Figure 6A and 6B reveals D-4F increased eNOS-dependent vasodilation in the hypercholesterolemic Ldlr–/–/apoA-I–/– mice by nearly 2-fold. However, in hypercholesterolemic double-knockout mice, D-4F failed to decrease vessel wall thickness (Figure 6C). Analysis of plasma lipids reveals HDL cholesterol in the Ldlr–/–/apoA-I–/– mice (Table 2) was decreased compared with the concentrations in Ldlr–/– mice (Table 1). D-4F had little effect on cholesterol in the hypercholesterolemic Ldlr–/–/apoA-I–/– mice but did increase HDL cholesterol (Table 2). More importantly, D-4F failed to protect HDL against oxidative modification in the double-knockout mice (Table 2), in contrast to its ability to protect HDL against oxidation in hypercholesterolemic Ldlr–/– mice (Table 1).
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Discussion |
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In recent years, much attention has focused on HDL as a therapeutic target for preventing vascular disease. Here time-dependent studies reveal D-4F increases vasodilation in direct relation to duration of treatments and interrupts or halts atherogenic mechanisms in vivo induced by feeding WD at all time points tested. Even short-term D-4F treatments reduced wall thickness in vessels from hypercholesterolemic Ldlr–/– mice before vasodilation was fully restored. These findings indicate improvements in vessel architecture precede improvements in vascular physiology. It is important to note that D-4F decreased wall thickness even in vessels with preexisting disease in mice with HDL that contains apoA-I, the major atheroprotective apolipoprotein of HDL, but not in mice whose HDL was apoA-I deficient. Although D-4F still improved vasodilation in mice lacking apoA-I, we think its inability to reduce wall thickness is linked to its inability to protect the apoA-I–deficient HDL against oxidation. As HDL function is impaired by oxidation,25,26 such findings strongly support the concept D-4F helps HDL maintain low levels of proinflammatory lipids, which should, in turn, improve vasodilation and reduce vessel wall thickness. Taken together, these findings underscore the importance of D-4F interacting with apoA-I on HDL to increase atheroprotection.
In the studies here, we assessed vessel wall architecture in the same vessel used to measure vasodilation. Therefore we could not perform histological analysis on these vessels. Instead, we relied on an unbiased assessment of wall thickness and explored potential mechanisms in endothelial cell cultures. Additional studies will be required to determine the precise cause of thickening of the facialis arteries in the future. In mechanistic studies, we showed that the proinflammatory oxysterol, 22-OHC, shifts ·NO and O2·– balance and increases collagen synthesis, both common features in vessels with early lesions.27 More importantly, the ability of 4F to restore ·NO and O2·– balance and reduce collagen production in 22-OHC–treated endothelial cell cultures is consistent with the marked increases in endothelium- and eNOS-dependent vasodilation and reductions in vessel wall thickness that we observed in hypercholesterolemic Ldlr–/– mice treated with D-4F.
Mechanistically, many of our findings are consistent with the notion that D-4F binds8 and removes oxidized lipids to protect vascular endothelial cell function.28 As eNOS function (coupled and uncoupled activity) in endothelial cell cultures is dramatically altered by native LDL and oxidized LDL,23,29,30 logically, anything limiting vascular endothelial cell exposure to proinflammatory lipids should improve eNOS-dependent vasodilation. The fact 4F did not alter 22-OHC-induced increases in ABCA-1 expression suggests endothelial cells exposed to 22-OHC are under a constant state of oxidative stress even in the presence of 4F. Accordingly, the ability of 4F to restore ·NO balance and reduce collagen expression in 22-OHC–treated endothelial cells is likely related more to the ability of this apoA-I mimetic to bind oxidized phospholipids than oxysterols. If this is the case, then one can envision 22-OHC increasing endothelial cell production of oxidized phospholipids that, in turn, shift ·NO balance and increase collagen production. Further, 4F, via binding oxidized phospholipids, should limit this autocrine-type exposure to the very proinflammatory lipids inducing this prooxidant and inflammatory phenotype (ie, 
O2·–, 
·NO, and increased collagen). Evidence supporting this hypothesis is the fact that 4F restored ·NO and O2·– balance without altering expression of ABCA-1. The fact that 4F did not alter ABCA-1 expression is also important by itself, because ABCA-1 provides a means for endothelial cells subjected to oxidative stress to more easily rid themselves of oxidized phospholipids.12 As ABCA-1 activity can be impaired via oxidation,12 our findings demonstrate 4F represents a therapeutic agent that helps to preserve the critical function of ABCA-1 within the endothelium.
Probing mechanisms for D-4F protecting HDL against oxidative modification, we observed D-4F had no effect on total MPO concentrations in the plasma of hypercholesterolemic Ldlr–/– mice, but did reduce MPO association with apoA-I and subsequent 3NT formation in apoA-I (an index of oxidative modification supporting our proinflammatory HDL findings). Such findings indicate that parallels do exist between the MPO-mediated mechanisms in mice and those in humans who have documented increased risk of heart disease.15 The fact that D-4F decreased MPO association with apoA-I in vivo but not in vitro suggests that the ability of D-4F to reduce MPO association with HDL in vivo is not attributable simply to displacement. It is possible that D-4F may also protect HDL indirectly by restoring ·NO and O2·– balance to the endothelium,6,23 which should, in turn, decrease O2·– and, subsequently, the H2O2 with which MPO nitrates tyrosine residues in apoA-I.15 Another possibility is that 4F increased extracellular superoxide dismutase, which should, in turn, decrease O2·–, as shown in diabetic rats by Kruger et al.31
Our studies using the Ldlr–/–/apoA-I–/– mice and D-4F revealed some remarkable insight into the atheroprotective mechanisms of HDL. First, HDL deficient in apoA-I is more susceptible to oxidation than apoA-I containing HDL by a mechanism that cannot be counteracted by D-4F treatments. Second, expression of apoA-I–deficient HDL can be increased by D-4F, suggesting D-4F may upregulate expression of other apolipoprotein A proteins, as it has been shown for apoA-I.32 Third, the marked increase in proinflammatory HDL in Ldlr–/–/apoA-I–/– mice directly correlates with an increase in wall thickness in these animals, which is in direct contrast to the ability of D-4F to improve vasodilation. This disconnect between the ability of D-4F to improve vasodilation and reduce vessel wall thickness was unexpected. One explanation for the inability of D-4F to protect HDL against oxidative modification in the Ldlr–/–/apoA-I–/– mice is the relative rates of DCF fluorescence, an index of seeding molecules of lipid hydroperoxides in HDL,11 were 100 times greater in HDL from Ldlr–/–/apoA-I–/– mice than it was in HDL from Ldlr–/– mice. Such large increases in proinflammatory HDL levels suggest 2 distinct possibilities: either apoA-I is essential for protecting HDL against oxidation and D-4F protects HDL against oxidation via interacting with apoA-I or the absolute amount of HDL plays a critical role in the mechanisms by which D-4F protects HDL against oxidation to reduce vessel wall thickness. Such observations are consistent with recent reports indicating cardiovascular events are mediated more by proinflammatory HDL than by total HDL,11,33 a report showing high concentrations of HDL are essential for reducing plaque growth in patients with preexisting carotid artery disease34 and our report showing 4F afforded greater protection in vivo than in vitro when compared with vessels preincubated with LDL.6
Perhaps D-4F was unable to interact with apoA-I–deficient HDL to bind and remove proinflammatory lipids that increase HDL susceptibility to oxidation.35 Alternatively, D-4F may interact directly with vascular endothelium to protect endothelial cell function as was recently shown by Gupta et al, where L-4F displaced lipopolysaccharide from vascular endothelium to preserve endothelial cell function.36 Another possibility is D-4F may act preferentially with vascular endothelial cells rather than vascular smooth muscle cells, which on exposure to oxidized LDL, express less matrix metalloproteases, which is considered to increase matrix deposition.37 Such questions, although important, must remain unanswered until more mechanistic studies can be performed.
In conclusion, D-4F reduces proinflammatory HDL levels in hypercholesterolemic Ldlr–/– mice but not Ldlr–/–/apoA-I–/– fed WD. The antiatherogenic properties of D-4F appear to go hand-in-hand with the ability of the apoA-I mimetic to reduce vessel wall thickness early on and then, with longer treatments, increase vasodilation to almost control levels in Ldlr–/– mice. Our studies suggest the mechanisms mediating impaired vasodilation in this early model of vascular disease may be different from those mediating vessel wall thickness. If this is the case, then HDL with the proper apolipoprotein composition and/or a critical concentration of HDL may be required for D-4F to be able to both reduce wall thickness and improve vasodilation. Finally, our findings suggest D-4F may be useful for treatment of arteries with preexisting disease.
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Acknowledgments |
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This study was supported, in part, by the Marie Z. Uihlein Endowed Chair Award, the Children’s Hospital Foundation (Milwaukee, Wis) (to K.T.O.); NIH grants HL 61417 and HL 71214 (to K.A.P.) and HL 064163 (to M.S-T.); American Heart Association Grants 0325546Z (to J.O.) and 0520103Z (to H.X.); The Scientific Research Foundation for the Returned Overseas Chinese Scholars, Guangzhou Government and State Education Ministry of China (to J.O.); The Administration of Public Health of Guangdong, China (A2005302) (to J.O.); Guangzhou Bureau of Education, China (1036 in 2004) (to J.O.); and Guangzhou Medical College, China (00-Q-06 and 03-G-06 to J.O.; 03-G-07 to Z.O.).
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Footnotes |
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Results were presented, in part, at the American Heart Association Scientific Sessions, Orlando, Fla, November 9–12, 2003 (Circulation. 2003;108:281), and New Orleans, La, November 7–10, 2004 (Circulation. 2004;110:243).
*Both authors contributed equally to the experimental design of this study. 
Original received August 4, 2005; revision received September 30, 2005; accepted October 3, 2005.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
- Candipan RC, Wang BY, Buitrago R, Tsao PS, Cooke JP. Regression or progression. Dependency on vascular nitric oxide. Arterioscler Thromb Vasc Biol. 1996; 16: 44–50.
[Abstract/Free Full Text] - Cohen RA, Zitnay KM, Haudenschild CC, Cunningham LD. Loss of selective endothelial cell vasoactive functions caused by hypercholesterolemia in pig coronary arteries. Circ Res. 1988; 63: 903–910.
[Abstract/Free Full Text] - Schachinger V, Britten MB, Zeiher AM. Prognostic impact of coronary vasodilator dysfunction on adverse long-term outcome of coronary heart disease. Circulation. 2000; 101: 1899–1906.
[Abstract/Free Full Text] - Nishimura RA, Lerman A, Chesebro JH, Ilstrup DM, Hodge DO, Higano ST, Holmes DR Jr, Tajik AJ. Epicardial vasomotor responses to acetylcholine are not predicted by coronary atherosclerosis as assessed by intracoronary ultrasound. J Am Coll Cardiol. 1995; 26: 41–49.[Abstract]
- Widlansky ME, Gokce N, Keaney JF Jr, Vita JA. The clinical implications of endothelial dysfunction. J Am Coll Cardiol. 2003; 42: 1149–1160.
[Abstract/Free Full Text] - Ou J, Ou Z, Jones DW, Holzhauer S, Hatoum OA, Ackerman AW, Weihrauch DW, Gutterman DD, Guice K, Oldham KT, Hillery CA, Pritchard KA Jr. L-4F, an apolipoprotein A-1 mimetic, dramatically improves vasodilation in hypercholesterolemia and sickle cell disease. Circulation. 2003; 107: 2337–2341.
[Abstract/Free Full Text] - Navab M, Anantharamaiah GM, Hama S, Garber DW, Chaddha M, Hough G, Lallone R, Fogelman AM. Oral administration of an Apo A-I mimetic peptide synthesized from D-amino acids dramatically reduces atherosclerosis in mice independent of plasma cholesterol. Circulation. 2002; 105: 290–292.
[Abstract/Free Full Text] - Navab M, Anantharamaiah GM, Reddy ST, Hama S, Hough G, Grijalva VR, Yu N, Ansell BJ, Datta G, Garber DW, Fogelman AM. Apolipoprotein A-I mimetic peptides. Arterioscler Thromb Vasc Biol. 2005; 25: 1325–1331.
[Abstract/Free Full Text] - Harada-Shiba M, Kinoshita M, Kamido H, Shimokado K. Oxidized low density lipoprotein induces apoptosis in cultured human umbilical vein endothelial cells by common and unique mechanisms. J Biol Chem. 1998; 273: 9681–9687.
[Abstract/Free Full Text] - Lizard G, Deckert V, Dubrez L, Moisant M, Gambert P, Lagrost L. Induction of apoptosis in endothelial cells treated with cholesterol oxides. Am J Pathol. 1996; 148: 1625–1638.[Abstract]
- Navab M, Hama SY, Hough GP, Subbanagounder G, Reddy ST, Fogelman AM. A cell-free assay for detecting HDL that is dysfunctional in preventing the formation of or inactivating oxidized phospholipids. J Lipid Res. 2001; 42: 1308–1317.
[Abstract/Free Full Text] - Reddy ST, Hama S, Ng C, Grijalva V, Navab M, Fogelman AM. ATP-binding cassette transporter 1 participates in LDL oxidation by artery wall cells. Arterioscler Thromb Vasc Biol. 2002; 22: 1877–1883.
[Abstract/Free Full Text] - Carpenter KL, Taylor SE, van der Veen C, Williamson BK, Ballantine JA, Mitchinson MJ. Lipids and oxidised lipids in human atherosclerotic lesions at different stages of development. Biochim Biophys Acta. 1995; 1256: 141–150.[Medline] [Order article via Infotrieve]
- Smalley DM, Hogg N, Kalyanaraman B, Pritchard KA Jr. Endothelial cells prevent accumulation of lipid hydroperoxides in low-density lipoprotein. Arterioscler Thromb Vasc Biol. 1997; 17: 3469–3474.
[Abstract/Free Full Text] - Zheng L, Nukuna B, Brennan ML, Sun M, Goormastic M, Settle M, Schmitt D, Fu X, Thomson L, Fox PL, Ischiropoulos H, Smith JD, Kinter M, Hazen SL. Apolipoprotein A-I is a selective target for myeloperoxidase-catalyzed oxidation and functional impairment in subjects with cardiovascular disease. J Clin Invest. 2004; 114: 529–541.[CrossRef][Medline] [Order article via Infotrieve]
- Nauseef WM. The proper study of mankind. J Clin Invest. 2001; 107: 401–403.[Medline] [Order article via Infotrieve]
- Brennan ML, Anderson MM, Shih DM, Qu XD, Wang X, Mehta AC, Lim LL, Shi W, Hazen SL, Jacob JS, Crowley JR, Heinecke JW, Lusis AJ. Increased atherosclerosis in myeloperoxidase-deficient mice. J Clin Invest. 2001; 107: 419–430.[Medline] [Order article via Infotrieve]
- Nicholls SJ, Hazen SL. Myeloperoxidase and cardiovascular disease. Arterioscler Thromb Vasc Biol. 2005; 25: 1102–1111.
[Abstract/Free Full Text] - Malle E, Waeg G, Schreiber R, Grone EF, Sattler W, Grone HJ. Immunohistochemical evidence for the myeloperoxidase/H2O2/halide system in human atherosclerotic lesions: colocalization of myeloperoxidase and hypochlorite-modified proteins. Eur J Biochem. 2000; 267: 4495–4503.[Medline] [Order article via Infotrieve]
- Podrez EA, Abu-Soud HM, Hazen SL. Myeloperoxidase-generated oxidants and atherosclerosis. Free Radic Biol Med. 2000; 28: 1717–1725.[CrossRef][Medline] [Order article via Infotrieve]
- Zabalawi M, Bhat S, Loughlin T, Thomas MJ, Alexander E, Cline M, Bullock B, Willingham M, Sorci-Thomas MG. Induction of fatal inflammation in LDL receptor and ApoA-I double-knockout mice fed dietary fat and cholesterol. Am J Pathol. 2003; 163: 1201–1213.
[Abstract/Free Full Text] - Ou J, Fontana JT, Ou Z, Jones DW, Ackerman AW, Oldham KT, Yu J, Sessa WC, Pritchard KA Jr. Heat shock protein 90 and tyrosine kinase regulate eNOS ·NO generation but not ·NO bioactivity. Am J Physiol Heart Circ Physiol. 2004; 286: H561–H569.
[Abstract/Free Full Text] - Ou Z, Ou J, Ackerman AW, Oldham KT, Pritchard KA Jr. L-4F, an apolipoprotein A-1 mimetic, restores nitric oxide and superoxide anion balance in low-density lipoprotein-treated endothelial cells. Circulation. 2003; 107: 1520–1524.
[Abstract/Free Full Text] - Siwik DA, Pagano PJ, Colucci WS. Oxidative stress regulates collagen synthesis and matrix metalloproteinase activity in cardiac fibroblasts. Am J Physiol Cell Physiol. 2001; 280: C53–C60.
[Abstract/Free Full Text] - Van Lenten BJ, Hama SY, de Beer FC, Stafforini DM, McIntyre TM, Prescott SM, La Du BN, Fogelman AM, Navab M. Anti-inflammatory HDL becomes pro-inflammatory during the acute phase response. Loss of protective effect of HDL against LDL oxidation in aortic wall cell cocultures. J Clin Invest. 1995; 96: 2758–2767.[Medline] [Order article via Infotrieve]
- Feingold KR, Memon RA, Moser AH, Grunfeld C. Paraoxonase activity in the serum and hepatic mRNA levels decrease during the acute phase response. Atherosclerosis. 1998; 139: 307–315.[CrossRef][Medline] [Order article via Infotrieve]
- Stary HC, Blankenhorn DH, Chandler AB, Glagov S, Insull W Jr, Richardson M, Rosenfeld ME, Schaffer SA, Schwartz CJ, Wagner WD, Wissler RW. A definition of the intima of human arteries and of its atherosclerosis-prone regions. A report from the Committee on Vascular Lesions of the Council on Arteriosclersosis, American Heart Assocation. Arteroscler Thromb. 1992; 12: 120–134.
[Free Full Text] - Navab M, Van Lenten BJ, Reddy ST, Fogelman AM. High-density lipoprotein and the dynamics of atherosclerotic lesions. Circulation. 2001; 104: 2386–2387.
[Free Full Text] - Stepp DW, Ou J, Ackerman AW, Welak S, Klick D, Pritchard KA Jr. Native LDL and minimally oxidized LDL differentially regulate superoxide anion in vascular endothelium in situ. Am J Physiol Heart Circ Physiol. 2002; 283: H750–H759.
[Abstract/Free Full Text] - Vergnani L, Hatrik S, Ricci F, Passaro A, Manzoli N, Zuliani G, Brovkovych V, Fellin R, Malinski T. Effect of native and oxidized low-density lipoprotein on endothelial nitric oxide and superoxide production: key role of L-arginine availability. Circulation. 2000; 101: 1261–1266.
[Abstract/Free Full Text] - Kruger AL, Peterson S, Turkseven S, Kaminski PM, Zhang FF, Quan S, Wolin MS, Abraham NG. D-4F induces heme oxygenase-1 and extracellular superoxide dismutase, decreases endothelial cell sloughing, and improves vascular reactivity in rat model of diabetes. Circulation. 2005; 111: 3126–3134.
[Abstract/Free Full Text] - Navab M, Anantharamaiah GM, Hama S, Hough G, Reddy ST, Frank JS, Garber DW, Handattu S, Fogelman AM. D-4F and statins synergize to render HDL antiinflammatory in mice and monkeys and cause lesion regression in old apolipoprotein E-null mice. Arterioscler Thromb Vasc Biol. 2005; 25: 1426–1432.
[Abstract/Free Full Text] - Ansell BJ, Navab M, Hama S, Kamranpour N, Fonarow G, Hough G, Rahmani S, Mottahedeh R, Dave R, Reddy ST, Fogelman AM. Inflammatory/antiinflammatory properties of high-density lipoprotein distinguish patients from control subjects better than high-density lipoprotein cholesterol levels and are favorably affected by simvastatin treatment. Circulation. 2003; 108: 2751–2756.
[Abstract/Free Full Text] - Johnsen SH, Mathiesen EB, Fosse E, Joakimsen O, Stensland-Bugge E, Njolstad I, Arnesen E. Elevated high-density lipoprotein cholesterol levels are protective against plaque progression: a follow-up study of 1952 persons with carotid atherosclerosis the Tromso study. Circulation. 2005; 112: 498–504.
[Abstract/Free Full Text] - Bielicki JK, Oda MN. Apolipoprotein A-I(Milano) and apolipoprotein A-I(Paris) exhibit an antioxidant activity distinct from that of wild-type apolipoprotein A-I. Biochemistry. 2002; 41: 2089–2096.[CrossRef][Medline] [Order article via Infotrieve]
- Gupta H, Dai L, Datta G, Garber DW, Grenett H, Li Y, Mishra V, Palgunachari MN, Handattu S, Gianturco SH, Bradley WA, Anantharamaiah GM, White CR. Inhibition of lipopolysaccharide-induced inflammatory responses by an apolipoprotein AI mimetic peptide. Circ Res. 2005; 97: 236–243.
[Abstract/Free Full Text] - Wilson D, Massaeli H, Pierce GN, Zahradka P. Native and minimally oxidized low density lipoprotein depress smooth muscle matrix metalloproteinase levels. Mol Cell Biochem. 2003; 249: 141–149.[CrossRef][Medline] [Order article via Infotrieve]
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