Arterial injury increases expression of inflammatory adhesion molecules in the carotid arteries of apolipoprotein-E-deficient mice

Recent studies demonstrate increased cellular adhesion molecule expression by neointimal endothelium overlying primary and restenotic atherosclerotic plaque. In this study, we developed an atherosclerotic mouse model of arterial injury and characterized adhesion molecule expression after injury. Sixteen apolipoprotein-E-(ApoE)-deficient mice fed a Western-type diet for 4 weeks underwent carotid artery wire denudation at week 2. For each segment, the extent of neointima formation and medial thickening, or adhesion molecule expression, were scored separately on a scale from 0 (no plaque/thickening or expression) to 3 (extensive plaque/thickening or expression) using Movat staining (n = 3) or immunohistochemical analysis (n = 13). Histology revealed significant medial thickening (1.8 +/- 0.9 vs. 0.3 +/- 0.5, p < 0. 001) versus controls and pronounced staining for monocytes/macrophages in the wall of injured vessels. Immunohistochemical analysis showed more robust expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the luminal surface of injured arteries versus controls (2.2 +/- 0.6 vs. 1.4 +/- 0.7, p < 0.01, and 2.5 +/- 0.5 vs. 1.2 +/- 0.6, p < 0.001, respectively). Injury increased adventitial ICAM-1 expression (2.6 +/- 0.5 vs. 1.6 +/- 0.5, p < 0.002) and medial VCAM-1 expression (2.2 +/- 0.6 vs. 1.2 +/- 0. 7, p < 0.004). Thus, carotid injury results in significant medial thickening and increases adhesion molecule expression beyond that induced in ApoE-deficient mice fed a Western diet alone. The observation of macrophage infiltration into the media at sites of increased ICAM-1 and VCAM-1 expression suggests that these molecules may mediate monocyte/macrophage trafficking into the wall of injured arteries.     

3-deazaadenosine prevents adhesion molecule expression and atherosclerotic lesion formation in the aortas of C57BL/6J mice

Adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) play an important role during the development of atherosclerosis. 3-Deazaadenosine (c(3)Ado), an adenosine analogue, inhibits endothelial-leukocyte adhesion and ICAM-1-expression in vitro. We hypothesized that c(3)Ado is able to prevent the expression of adhesion molecules and atherosclerotic lesion formation in female C57BL/6J mice. The animals were placed on an atherogenic diet with or without c(3)Ado for 9 weeks. Frozen cross sections of the proximal ascending aorta just beyond the aortic sinus were stained with oil red O, hematoxylin, and elastic van Gieson's stains and were analyzed by computer-aided planimetry for fatty plaque formation and neointimal proliferation. Monoclonal antibodies against CD11b (macrophages), VCAM-1, and ICAM-1 were used for immunohistochemistry. Mice on the atherogenic diet demonstrated multiple (5.4+/-1.6 per animal) lesions covering 3.4+/-2.8% of the endothelium and a marked neointima when compared with control mice (4501+/-775 versus 160+/-38 microm(2), P<0.001). Mice on the cholesterol-rich diet without c(3)Ado showed strong endothelial coexpression of ICAM-1 and VCAM-1. Moreover, there was a 10-fold increase in monocyte accumulation on the endothelial surface (33. 3+/-4.9 versus 3.8+/-1.2, P<0.004). In contrast, in mice treated with c(3)Ado, expression of ICAM-1 and VCAM-1 as well as monocyte adhesion and infiltration were almost completely inhibited. Furthermore, these mice did not show any fatty streak formation or neointima formation (125+/-32 microm(2)). Our results demonstrate that c(3)Ado can inhibit diet-induced fatty streak formation and the expression of endothelial ICAM-1 and VCAM-1 in C57BL/6J mice. This may provide a novel pharmacological approach in the prevention and treatment of atherosclerosis.     

Local monocyte chemoattractant protein-1 therapy increases collateral artery formation in apolipoprotein E-deficient mice but induces systemic monocytic CD11b expression,neointimal formation,and plaque progression

Monocyte chemoattractant protein-1 (MCP-1) stimulates the formation of a collateral circulation on arterial occlusion. The present study served to determine whether these proarteriogenic properties of MCP-1 are preserved in hyperlipidemic apolipoprotein E-deficient (apoE-/-) mice and whether it affects the systemic development of atherosclerosis. A total of 78 apoE-/- mice were treated with local infusion of low-dose MCP-1 (1 microg/kg per week), high-dose MCP-1 (10 microg/kg per week), or PBS as a control after unilateral ligation of the femoral artery. Collateral hindlimb flow, measured with fluorescent microspheres, significantly increased on a 1-week high-dose MCP-1 treatment (PBS 22.6+/-7.2%, MCP-1 31.3+/-10.3%; P<0.05). These effects were still present 2 months after the treatment (PBS 44.3+/-4.6%, MCP-1 56.5+/-10.4%; P<0.001). The increase in collateral flow was accompanied by an increase in the number of perivascular monocytes/macrophages on MCP-1 treatment. However, systemic CD11b expression by monocytes also increased, as did monocyte adhesion at the aortic endothelium and neointimal formation (intima/media ratio, 0.097+/-0.011 [PBS] versus 0.257+/-0.022 [MCP-1]; P<0.0001). Moreover, Sudan IV staining revealed an increase in aortic atherosclerotic plaque surface (24.3+/-5.2% [PBS] versus 38.2+/-9.5% [MCP-1]; P<0.01). Finally, a significant decrease in the percentage of smooth muscle cells was found in plaques (15.0+/-5.2% [PBS] versus 5.8+/-2.3% [MCP-1]; P<0.001). In conclusion, local infusion of MCP-1 significantly increases collateral flow on femoral artery ligation in apoE-/- mice up to 2 months after the treatment. However, the local treatment did not preclude systemic effects on atherogenesis, leading to increased atherosclerotic plaque formation and changes in cellular content of plaques.     

Thrombogenic effects of antiphospholipid antibodies are mediated by intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1, and P-selectin

Recent studies have shown that antiphospholipid (aPL) enhances expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin on endothelial cells (ECs) and that these effects are correlated with increased adhesion of leukocytes to endothelium in cremaster muscle in vivo and with thrombosis in a mouse model. Activation of ECs by aPL may create a hypercoagulable state that precedes and contributes to thrombosis in patients with aPL syndrome (APS). This study proposed to examine whether this in vivo activation of ECs and enhanced thrombosis by aPL are mediated by ICAM-1, P-selectin, or VCAM-1. The dynamics of thrombus formation and the number of adhering leukocytes were studied in ICAM-1-deficient (ICAM-1(-/-)) mice or ICAM-1-/P-selectin-deficient (ICAM-1(-/-)/P-selectin(-/-)) mice treated with affinity-purified aPL antibodies (ap IgG-APS) or with control IgG and compared with wild-type mice treated in a similar fashion. In another set of experiments, the adhesion of leukocytes to cremaster muscle and the dynamics of thrombus formation were studied in CD1 mice treated with aPL or control IgG before and 30 minutes after intravenous infusion with 100 microg monoclonal antibody anti-VCAM-1. The results indicate that the enhanced adhesion of leukocytes to endothelium in wild-type mice was significantly reduced in ICAM-1(-/-) and completely abrogated in ICAM-1(-/-)/P-selectin(-/-) mice treated with ap IgG-APS compared with wild-type mice treated with ap IgG-APS (6.9+/-2.3, 0.4+/-0.4 versus 35+/-12, respectively). More importantly, this correlated with a significant reduction in thrombus size compared with wild-type mice treated with ap IgG-APS (895+/-259 microm(2), 859+/-243 microm(2) versus 3816+/-672 microm(2), respectively). Infusion of the mice with anti-VCAM-1 antibodies significantly reversed the enhanced adhesion of leukocytes (14.9+/-3 to 11.3+/-2.1) and thrombus size 3830+/-1008 microm(2) versus 876+/-548 microm(2)) in mice treated with ap IgG-APS. The data indicate that ICAM-1, P-selectin, and VCAM-1 expression are important in thrombotic complications by aPL antibodies and may provide novel targets for therapy in patients with APS.     

Fcgamma receptor deficiency confers protection against atherosclerosis in apolipoprotein E knockout mice

IgG Fc receptors (FcgammaRs) play a role in activating the immune system and in maintaining peripheral tolerance, but their role in atherosclerosis is unknown. We generated double-knockout (DKO) mice by crossing apolipoprotein E-deficient mice (apoE(-/-)) with FcgammaR gamma chain-deficient mice (gamma(-/-)). The size of atherosclerotic lesions along the aorta was approximately 50% lower in DKO compared with apoE(-/-) control mice, without differences in serum lipid levels. The macrophage and T-cell content of lesions in the DKO were reduced by 49+/-6% and 56+/-8%, respectively, compared with the content in apoE(-/-) lesions. Furthermore, the expression of monocyte chemoattractant protein-1 (MCP-1), RANTES (Regulated on Activated Normal T-cell Expressed and Secreted), and intercellular adhesion molecule-1 (ICAM-1) and the activation of nuclear factor-kappaB (NF-kappaB) were significantly reduced in aortic lesions from DKO mice. In vitro, vascular smooth muscle cells (VSMCs) from both gamma(-/-) and DKO mice failed to respond to immune complexes, as shown by impaired chemokine expression and NF-kappaB activation. ApoE(-/-) mice have higher levels of activating FcgammaRI and FcgammaRIIIA, and inhibitory FcgammaRIIB, compared with wild-type mice. The DKO mice express only the inhibitory FcgammaRIIB receptor. We conclude that FcgammaR deficiency limits development and progression of atherosclerosis. In addition to leukocytes, FcgammaR activation in VSMCs contributes to the inflammatory process, in part, by regulating chemokine expression and leukocyte invasion of the vessel wall. These results underscore the critical role of FcgammaRs in atherogenesis and support the use of immunotherapy in the treatment of this disease.     

Patterns of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 expression in rabbit and mouse atherosclerotic lesions and at sites predisposed to lesion formation.

The recruitment of mononuclear leukocytes and formation of intimal macrophage-rich lesions at specific sites of the arterial tree are key events in atherogenesis. Inducible endothelial cell adhesion molecules may participate in this process. In aortas of normal chow-fed wild-type mice and rabbits, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), but not E-selectin, were expressed by endothelial cells in regions predisposed to atherosclerotic lesion formation. En face confocal microscopy of the mouse ascending aorta and proximal arch demonstrated that VCAM-1 expression was increased on the endothelial cell surface in lesion-prone areas. ICAM-1 expression extended into areas protected from lesion formation. Hypercholesterolemia induced atherosclerotic lesion formation in rabbits, LDL receptor and apolipoprotein E knockout mice, and Northern blot analysis demonstrated increased steady-state mRNA levels of VCAM-1 and ICAM-1, but not of E-selectin. Immunohistochemical staining revealed that VCAM-1 and ICAM-1 were expressed predominantly by endothelium in early lesions and by intimal cells in more advanced lesions. In early and advanced lesions, staining was most intense in endothelial cells at and adjacent to lesion borders. ICAM-1 staining extended into the uninvolved aorta. These expression patterns were highly reproducible in both species. The only difference was that VCAM-1 expression in endothelium over the central portions of lesions was found frequently in rabbits and rarely in mice. The expression of VCAM-1 by arterial endothelium in normal animals may represent a pathogenic mechanism or a phenotypic marker of predisposition to atherogenesis.     

Suppression of circulating interleukin-6 concentrations is associated with decreased endothelial activation in rheumatoid arthritis

BACKGROUND: Circulating interleukin (IL)-6 concentrations are associated with endothelial activation in rheumatoid arthritis (RA). OBJECTIVE: To assess endothelial activation before and after suppression of cytokine production in RA. METHODS: Twenty-one patients (mean (SD) age 59 (9) years; disease duration 6 (4) years) were treated with intraarticular methylprednisolone acetate (417 (152) mg) together with disease modifying agent (DMARD) initiation (n = 10) or intensification (n = 11) employing methotrexate (n = 11), leflunomide (n = 8), minocyclin (n = 6) and sulphasalazine (n = 1). Disease activity, circulating cytokines (IL-1, tumor necrosis factor alpha (TNF-alpha) and IL-6) and biomarkers of endothelial activation (circulating vascular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and endothelial leukocyte adhesion molecule-1 (ELAM-1)) were evaluated before and 2 weeks after treatment. RESULTS: The intervention resulted in reductions in 8 disease activity markers (p < or = 0.002). Serum IL-6 concentrations decreased from 17 (2.9) to 4.9 (4.6) pg/ml (p = 0.0008). Serum IL-1 and TNF-alpha levels did not change (p > or = 0.4). Serum VCAM-1 concentrations decreased from 912 (402) to 752 (252) (p = 0.003), ICAM-1 from 398 (205) to 323 (179) (p = 0.04) and ELAM-1 from 68 (28) to 53 (25) (p = 0.02) pg/ml, respectively. Baseline rheumatoid factor titers were associated with reductions in VCAM-1 (r(s) = 0.481, p = 0.03). In multivariable regression models, decreases in circulating interleukin-6 concentrations were associated with reductions in VCAM-1 (p < 0.0001), ICAM-1 (p = 0.005) and ELAM-1 (p = 0.02) independent of changes in disease activity, weight and blood pressure. CONCLUSION: Our results suggest that suppression of circulating IL-6 concentrations attenuates atherogenesis in active RA.     

葛根总黄酮对载脂蛋白E基因缺陷小鼠动脉粥样硬化病变内细胞凋亡及凋亡相关基因的影响

目的 探讨葛根总黄酮对载脂蛋白E基因缺陷（apoE-／-）小鼠主动脉窦动脉粥样硬化斑块抑制作用的分子机制。方法 采用电镜观察、缺口末端标记（TUNEL）法检测apoE-／-小鼠动脉粥样硬化斑块内的细胞凋亡。免疫组化方法检测平滑肌细胞、巨噬细胞及Caspase一3蛋白的表达。结果 电镜观察到凋亡细胞核形不规则,胞核内染色质浓集、边聚,附着在核膜周边,线粒体肿胀,内质网扩张,超微结构形态符合巨噬细胞早期凋亡,并可见典型凋亡小体形成。TUNEL结果表明,凋亡细胞主要分布在粥样斑块脂质核心处,模型组动脉粥样硬化斑块内凋亡细胞数较多,而葛根总黄酮干预组凋亡细胞数明显减少,葛根高、低剂量组细胞凋亡率明显低于模型组[分别为（0．38±0．17）ok,（1．95±1．02）％,（10．50±5．89）％,P〈0．01],葛根高剂量组细胞凋亡率明显低于葛根低剂量组。抗CD68抗体免疫组化染色证实在动脉粥样硬化斑块脂质坏死核心内细胞CD68强阳性表达。葛根高、低剂量治疗组Caspase-3蛋白免疫表达低于模型组,葛根高剂量治疗组低于葛根低剂量治疗组。结论 葛根总黄酮可能通过下调apoE-／-小鼠主动脉窦动脉粥样硬化病变内Caspases-3蛋白的表达,显著降低了动脉粥样硬化病变内巨噬细胞凋亡,从而抑制了动脉粥样硬化斑块的进展。     

Plaque-associated endothelial dysfunction in apolipoprotein E-deficient mice on a regular diet. Effect of human apolipoprotein AI

OBJECTIVE: Apolipoprotein E-deficient mice (apoE(-/-)) on a regular diet become hypercholesterolemic and develop atherosclerosis, but endothelium-dependent relaxation remains undisturbed for up to 6 months. We investigated whether vasomotor dysfunction develops in aged apoE(-/-), whether the defect was systemic (hypercholesterolemia-dependent) or focal (plaque-related), and the effect of human apolipoprotein AI transgenesis (apoAI/E(-/-)). METHODS: Arteries of apoE(-/-) (n=5), apoAI/E(-/-) (n=6) and C57Bl/6J (WT, n=4) mice (18 months) were systematically dissected for isometric tension recording and subsequent morphometry. RESULTS: Acetylcholine (ACh)-induced relaxation was impaired (P<0.01) in atherosclerotic segments of apoE(-/-) (26+/-14%) as compared to WT mice (93+/-2%). Similar reduced (P<0.01) responses to adenosine 5'-triphosphate (apoE(-/-) 38+/-14, WT 94+/-3%) and the calcium ionophore A23187 (apoE(-/-) 19+/-6%, WT 97+/-2%) pointed to a post-receptor defect. Indeed, responses to exogenous nitric oxide were impaired in atherosclerotic segments as well (apoE(-/-) 71+/-7%, WT 92+/-1%, P<0.05). Furthermore, relaxations inversely correlated with plaque size (ACh r(s)=-0.74, P<0.01). In adjacent plaque-free segments however, responses to ACh (apoE(-/-) 92+/-3%, WT 97+/-1%) and all other agents were preserved, despite the prolonged hypercholesterolemia. ApoAI improved vasomotor responses in atherosclerotic segments. However, negative correlations between maximal relaxation and plaque area remained in apoAI/E(-/-) mice (ACh r(s)=-0.67, P<0.01). Indeed, covariate analysis of variance did not point to direct protection of vasomotor function by apoAI when the smaller lesions were taken into account. CONCLUSIONS: Endothelial dysfunction in apoE(-/-) mice is not affected by hypercholesterolemia alone, but is strictly associated with plaque formation. Human apoAI transgenesis-known to raise HDL-attenuated atherogenesis, thereby indirectly improving relaxation responses in apoE(-/-) mice.     

Orally administered eicosapentaenoic acid reduces and stabilizes atherosclerotic lesions in ApoE-deficient mice

Accumulating evidence demonstrates that dietary intake of n-3 polyunsaturated fatty acids (PUFAs) is associated with reduced incidence of cardiovascular events. However, the molecular mechanisms by which n-3 PUFAs prevent atherosclerosis are not fully understood. Here, we examined the effect of eicosapentaenoic acid (EPA), a major n-3 PUFA, on the pathogenesis of atherosclerosis in ApoE-deficient mice. Five-week-old ApoE-deficient male mice were fed on western-type diet supplemented with 5% (w/w) EPA (EPA group, n=7) or not (control group, n=5) for 13 weeks. An analysis of the fatty acid composition of liver homogenates revealed a marked increase of the n-3 PUFA content in the EPA group (n-3/n-6 ratio: 0.20+/-0.01 vs. 2.5+/-0.2, p<0.01). En face Sudan IV staining of the aorta and oil red O-staining of the aortic sinus revealed that EPA significantly suppressed the development of atherosclerotic lesions. We also observed anti-atherosclerotic effects of EPA in LDL-receptor-deficient mice. The lesions of the EPA group contained more collagen (19.6+/-2.4% vs. 32.9+/-3.9%, p<0.05) and smooth muscle cells (1.3+/-0.2% vs. 3.6+/-0.8%, p<0.05) and less macrophages (32.7+/-4.1% vs. 14.7+/-2.0%, p<0.05). Pretreatment with EPA attenuated the up-regulation of VCAM-1, ICAM-1 and MCP-1 in HUVECs as well as the expression of MMP-2 and MMP-9 in macrophage-like cells induced by TNF-alpha. The anti-inflammatory effects of EPA were abrogated when the expression of peroxisome proliferator-activated receptor alpha (PPARalpha) was suppressed. EPA may potentially reduce and stabilize atherosclerotic lesions through its anti-inflammatory effects.     

Circulating ICAM-1 and VCAM-1 levels in patients with obstructive sleep apnea syndrome

BACKGROUND: Obstructive sleep apnea syndrome (OSAS)-induced hypoxic stress modulates circulating inflammatory mediators causing accelerated atherogenesis. OBJECTIVES: We hypothesized that OSAS-induced hypoxia might result in cardiovascular disease due to increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the endothelial surface. METHODS: Thirty-nine subjects with moderate-to-severe OSAS and 34 non-apneic controls matched for age, gender, body mass index (BMI), smoking history, and cardiovascular disease were included in this prospective study. Overnight polysomnography was performed. Circulating ICAM-1 and VCAM-1 levels in the serum were measured by enzyme-linked immunosorbent assay. RESULTS: Circulating levels of both ICAM-1 (480.1 +/- 216.7 vs. 303.4 +/- 98.6 ng/ml, p < 0.0001) and VCAM-1 (1,156.6 +/- 79.8 vs. 878.8 +/- 71.1 ng/ml, p = 0.002) were significantly increased in the OSAS group compared to the control group. For an ICAM-1 cutoff level of 375 ng/ml, predictive sensitivity and specificity for OSAS were 69.2% (95% confidence interval, CI: 52.4-83.0%) and 82.4% (95% CI: 65.5-93.2%), respectively. For a VCAM-1 cutoff level of 859 ng/ml, predictive sensitivity and specificity for OSAS were 74.4% (95% CI: 57.9-86.9%) and 64.7% (95% CI: 46.5-80.2%), respectively. There was a significant positive correlation between circulating levels of ICAM-1 and ln of AHI (r = 0.276, p = 0.018). Multiple logistic regression analyses showed that OSAS was associated with high ICAM-1 and high VCAM-1 levels independent of age, gender, BMI, smoking status and cardiovascular disease. CONCLUSION: We conclude that OSAS can independently increase circulating levels of adhesion molecules     

Circulating intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin in patients with type 2 diabetes mellitus

Serum levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin in patients with type 2 diabetes mellitus (n = 64) and control subjects (n = 40) were studied. Serum ICAM-1 concentrations in diabetic patients were significantly higher than those of control subjects (378.2 +/- 70.0 versus 220.4 +/- 31.8 ng/ml, P < 0.01). By multiple regression analysis, hemoglobin A1c was independently associated with serum ICAM-1 concentration in patients with diabetes. The serum VCAM-1 concentration of diabetic patients with macroangiopathy was higher than those of patients without macroangiopathy and of control subjects (806.9 + 276.5 versus 639.0 +/- 146.0 (P < 0.01), and 652.1 +/- 146.9 ng/ml (P < 0.01), respectively). There was no difference in serum E-selectin concentration between diabetic patients with or without macroangiopathy and normal control subjects. These results suggest that adhesion molecules may contribute to the development of atherosclerosis in the diabetic state.     

Plasma insulin levels predict atherosclerotic lesion burden in obese hyperlipidemic mice

Despite a clear association between obesity, insulin resistance and atherosclerosis in humans, to date, no animal models have been described in which insulin resistance is associated with atherosclerotic lesion burden. Using two mouse models of obesity-induced hyperlipidemia:leptin deficient (ob/ob) mice on an apolipoprotein E deficient (apoE-/-) or low density lipoprotein receptor deficient (LDLR-/-) background, we sought to determine metabolic parameters most closely associated with atherosclerotic lesion burden. Total plasma cholesterol (TC) levels in ob/ob;apoE-/- mice and ob/ob;LDLR-/- mice were indistinguishable (682+/-48 versus 663+/-16, respectively). Analysis of lipoprotein profiles showed that cholesterol was carried primarily on VLDL in the ob/ob;apoE-/- mice and on LDL in the ob/ob;LDLR-/- mice. Plasma triglycerides (TG) were 55% lower (P<0.001), non-esterified fatty acids (NEFA) were 1.5-fold higher (P<0.01), and insulin levels were 1.7-fold higher (NS) in ob/ob;apoE-/- mice compared to ob/ob;LDLR-/- mice. Other parameters such as body weight, fat pad weight, and glucose levels were not different between the groups. Aortic sinus lesion area of ob/ob;apoE-/- mice was increased 3.2-fold above ob/ob;LDLR-/- mice (102,455+/-8565 microm2/section versus 31,750+/-4478 microm2/section, P<0.001). Lesions in ob/ob;apoE-/- mice were also more complex as evidenced by a 7.7-fold increase in collagen content (P<0.001). Atherosclerotic lesion area was positively correlated with body weight (P<0.005), NEFA (P=0.007), and insulin (P=0.002) levels in the ob/ob;LDLR-/- mice and with insulin (P=0.014) in the ob/ob;apoE-/- mice. In contrast, lesion burden was neither associated with TC and TG, nor with individual lipoprotein pools, in either animal model. These data provide a direct demonstration of the pathophysiologic relevance of hyperinsulinemia, NEFA, and increased body weight to atherosclerotic lesion formation.     

The atheroprotective effect of 17 beta-estradiol is not altered in P-selectin- or ICAM-1-deficient hypercholesterolemic mice

The mechanisms that mediate the atheroprotective properties of estrogens remain obscure. In the present study, we evaluated the involvement of the adhesion molecule P-selectin, intercellular adhesion molecule (ICAM-1) and vascular cell adhesion molecule (VCAM-1) in the atheroprotective effect of estrogens in murine models evaluating early steps of atherosclerosis. First, we studied the effect of 17 beta-estradiol (E2) administration for 12 weeks on fatty streak constitution at the root aorta of ovariectomized female mice deficient in apolipoprotein E (apoE) alone or deficient in both apoE and either P-selectin or ICAM-1. Compared with respective placebo groups, E2 significantly prevented the development of fatty streak, to a similar extent in all three genotypes (-70.0% in apoE(-/-), -77.4% in apoE(-/-) P-selectin(-/-), and -77.1% in apoE(-/-) ICAM-1(-/-)). Second, the endothelial expression of VCAM-1 at the root aorta was assessed by immunohistochemistry in either placebo or E2-treated ovariectomized C57BL/6 female mice fed an atherogenic diet. Compared with placebo, E2 treatment resulted in a 31.8% decrease of VCAM-1 endothelial expression at this lesion-prone site (P=0.03). These results demonstrate that P-selectin and ICAM-1 are not involved in the atheroprotective effect of estrogens, and suggest that VCAM-1 could play a role in this process.     

Soluble VCAM-1 and E-selectin, but not ICAM-1 discriminate endothelial injury in patients with documented coronary artery disease

It has been shown that endothelial cell adhesion molecules play an important role in the development of coronary atherosclerosis and inflammatory disease. We sought to test whether soluble vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin are increased in patients with documented coronary artery disease (CAD). Plasma levels of VCAM-1, ICAM-1 and E-selectin were measured in 40 patients with documented CAD, 20 subjects with angiographically documented normal coronary arteries, and 14 healthy volunteers. Patients with documented CAD exhibited significant elevation of VCAM-1 (535 +/- 227.1 ng/ml, p = 0.0001), E-selectin (69.4 +/- 29.4 ng/ml, p = 0.006), but not ICAM-1 (320.5 +/- 65.1 ng/ml, p = 0.9) concentrations as compared to subjects with normal coronary arteries (252.3 +/- 79.8, 49.7 +/- 22.0 and 311.4 +/- 40.2 ng/ml), and healthy controls (110.0 +/- 17.7, 29.0 +/- 2.0 and 237.5 +/- 46.5 ng/ml), respectively. Soluble markers of endothelial injury are not uniformly increased in patients with documented CAD as compared to those with normal coronary arteries and healthy controls. However, VCAM-1 and E-selectin, but not ICAM-1 could identify endothelial injury in such patients.