Regulation of adhesion molecules during human endotoxemia. No acute effects of aspirin

Gram-negative septic shock is mediated in part by endotoxin (lipopolysaccharide; LPS), and animal models have shown that blockade of even single adhesion molecules considerably improves survival. Thus interference with the adhesion cascade may provide a useful therapeutic approach in human sepsis. Young healthy men (n = 30) each received a bolus of 4 ng/kg LPS intravenously to study the effects of endotoxemia on adhesion processes in humans and to identify potential targets for pharmacologic intervention. One third of subjects received pretreatment with 1,000 mg aspirin and 1,000 mg paracetamol to study potential antiinflammatory effects of aspirin or effects of antipyresis. Circulating neutrophils dropped by -80% at 67 min after LPS, monocytes by -96% at 90 min, and lymphocytes by -85% at 240 min. L-selectin expression decreased, particularly on monocytes. Circulating (c)E-selectin levels increased by 820%, von Willebrand factor-Ag (vWF), soluble thrombomodulin, circulating (c)P-selectin, circulating intercellular adhesion molecule-1 (cICAM-1), and circulating vascular cell adhesion molecule-1 (cVCAM-1) by a mean of 65 to 98% (p < 0.001 for all), but cL-selectin by only 15%. Urinary excretion of soluble adhesion molecules was negligible. Aspirin had no influence on the LPS-induced changes of adhesion parameters, but paracetamol blunted the relative increase in vWF while having no effects on the other parameters measured. The consistent, profound, and early upregulation of cE-selectin during endotoxemia indicates that cE-selectin may be a better surrogate marker to monitor the activation status of endothelial cells in systemic inflammation than the other markers measured. Although aspirin did not have any antiinflammatory effects in this model, paracetamol lowered the relative increase in vWF.     

E-selectin and TFPI are associated with carotid intima-media thickness in stable IHD patients: the baseline findings of the MIAMI study

ObjectiveMIAMI was a prospective multicenter clinical study designed to investigate the relationship between changes in carotid intima-media thickness (C-IMT) and those in the levels of circulating markers of inflammation, thrombosis and endothelial dysfunction. The study was performed in a group of stable coronary patients treated for two years with a moderate dosage of atorvastatin (20 mg/day). In this paper the cross-sectional relationship between C-IMT and the same circulating markers of inflammation, thrombosis and endothelial dysfunction measured at baseline was investigated.MethodsEighty-five subjects that had not used statins for at least two months were enrolled in the study. At time of enrollment, the levels of vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin, interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, high-sensitivity C-reactive protein (hs-CRP), tissue factor (TF), tissue factor pathway inhibitor (TFPI), von Willebrand factor (vWF), fibrinogen, total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL), and triglycerides were measured, in parallel with C-IMT assessment.ResultsIn cross-sectional analyses, markers of endothelial perturbation (i.e. E-selectin) and TFPI were more strongly correlated with arherosclerotic burden than markers of inflammation. The baseline picture in this study indicates that E-selectin and TFPI are linked with atherosclerotic burden.     

Aortic endothelial cell von Willebrand factor content, and circulating plasminogen activator inhibitor-1 are increased, but expression of endothelial leukocyte adhesion molecules is unchanged in insulin-dependent diabetic BB rats

Endothelial cell injury has been implicated in the increased incidence of vascular disease associated with diabetes mellitus. In diabetic humans, elevated plasma von Willebrand Factor (vWF) has been interpreted as an indication of endothelial damage. In contrast, in an animal model of inherited insulin-dependent diabetes, the bio-breeding (BB) rat, plasma vWF levels did not differ from those in age-matched control rats during the first 7 months of diabetes although morphological evidence of mild aortic endothelial alteration or injury was observed. In the present study efforts have been made to define the endothelial alterations in BB diabetic rats compared to controls more precisely over this time period. Thus, adhesion molecules: intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1(VCAM-1) were evaluated by in situ immunohistochemistry, vWF content was determined by biochemical analysis of aortic extracts and by quantitative immunohistochemistry, plasma vWF levels were measured by ELISA and vWF mRNA by RNAse protection assay. Neither age nor diabetic state significantly affected either the expression of adhesion molecules, or the levels of circulating vWF. Endothelial vWF content was significantly increased in the diabetic vessels, as observed by both approaches but the vWF mRNA content was not different from that in control vessels. Plasma plasminogen activator inhibitor (PAI-1) activity was significantly increased in diabetic animals. In conclusion, endothelial alterations in BB rats associated with diabetes, together with the raised plasma PAI-1 levels, promote the thrombogenic potential of the vessel wall, and are consistent with an increased risk for vascular disease.     

Insulin resistance and adiposity correlate with acute-phase reaction and soluble cell adhesion molecules in type 2 diabetes

OBJECTIVE: To investigate the relationship of inflammation and endothelial activation with insulin resistance and adiposity in type 2 diabetes. METHODS AND RESULTS: Hundred and thirty-four (45 female) type 2 diabetic subjects aged 50-75 in the Fenofibrate Intervention and Event Lowering in Diabetes Study in Helsinki were examined before fenofibrate intervention. Fasting levels of circulating intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) (vascular cell adhesion molecule), ultra-sensitive C-reactive protein (CRP), human serum amyloid A (hSAA), interleukin-6 (IL-6), macrophage colony-stimulating factor (M-CSF), secretory phospholipase A(2) IIA (PLA(2)), total, HDL and LDL cholesterol, triglycerides, P-glucose, HbA1c, and serum free insulin were determined. Insulin resistance was assessed by the homeostasis model. HOMA IR correlated significantly with all measures of adiposity and markers of inflammation and endothelial dysfunction. BMI was significantly associated with inflammation and endothelial activation, but with neither lipoproteins nor glycaemic control. After controlling for age, gender and BMI, HbA1c correlated significantly with CRP, hSAA, ICAM-1, E-selectin, and HOMA IR. HDL cholesterol correlated inversely with IL-6, M-CSF, E-selectin, and HOMA IR. HbA1c, phospholipase A(2), VCAM-1, and HDL cholesterol remained independent determinants of HOMA IR in the linear regression analysis controlled for age, gender, and BMI. CONCLUSION: Endothelial activation and acute-phase reaction correlate with insulin resistance and obesity in type 2 diabetic patients.     

Circulating vascular cell adhesion molecules VCAM-1, ICAM-1, and E-selectin in dependence on aging

BACKGROUND: Elevated levels of circulating cell adhesion molecules (cCAMs) such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and endothelial leukocyte adhesion molecule-1 (E-selectin) are found in subjects with vascular diseases and in subjects with several risk factors for atherosclerosis. However, data evaluating cCAMs and biological age are limited. OBJECTIVE: The purpose of this study was to assess in subjects with different cardiovascular risk profiles the levels of cVCAM-1, cICAM-1, and cE-selectin in dependence on age. METHODS: The following groups of subjects were included in the study: 282 apparently healthy subjects of the average population aged 18-89 years, 77 vegetarians who are characterized by a favourable global cardiovascular risk profile, 94 patients with coronary heart disease, and 181 patients with peripheral arterial occlusive disease. Blood samples were obtained after an overnight fast for measurement of cCAMs, lipoproteins, and other clinical/biochemical parameters. The cCAM levels were determined by the use of monoclonal antibody based enzyme-linked immunosorbent assays. RESULTS: Amongst the cCAMs, cVCAM-1 is uniquely elevated in elderly persons with different risks for atherosclerosis, including subjects of the average population, vegetarians with a favourable risk profile, and patients with both coronary heart disease and peripheral arterial occlusive disease. With respect to cICAM-1, an age-dependent elevation was found in the control subjects included in the study. The cE-selectin levels were not correlated with age. Moreover, no associations of cCAMs with serum lipid and lipoprotein levels were found. CONCLUSION: The results of the present study indicate that cVCAM-1 is an age-dependent parameter independent of cardiovascular risk.     

No effect of acenocoumarol therapy on levels of endothelial activation markers in sickle cell disease

Sickle cell patients are characterized by a chronic inflammatory and hypercoagulable state, depicted by elevated levels of pro-inflammatory cytokines, endothelial adhesion molecules, and elevated markers of thrombin generation. We set out to determine whether anticoagulation with a coumadin derivative reduces inflammation in sickle cell disease. Therefore, serum levels of NFkappaB-regulated endothelial adhesion molecule soluble vascular cell adhesion molecule-1 and serum levels of non-NFkappaB-dependent markers of endothelial activation (soluble cellular fibronectin and von Willebrand factor antigen) were compared during treatment with acenocoumarol (INR 1.6-2.0) and placebo. No effect on circulating levels of the measured parameters was observed during treatment with acenocoumarol as compared to placebo. In the targeted INR range, anticoagulation of sickle cell patients with acenocoumarol does not seem to reduce endothelial activation.     

Levels of soluble endothelium-derived adhesion molecules in patients with sickle cell disease are associated with pulmonary hypertension, organ dysfunction, and mortality

Endothelial cell adhesion molecules orchestrate the recruitment and binding of inflammatory cells to vascular endothelium. With endothelial dysfunction and vascular injury, the levels of endothelial bound and soluble adhesion molecules increase. Such expression is modulated by nitric oxide (NO), and in patients with sickle cell disease (SCD), these levels are inversely associated with measures of NO bioavailability. To further evaluate the role of endothelial dysfunction in a population study of SCD, we have measured the levels of soluble endothelium-derived adhesion molecules in the plasma specimens of 160 adult patients with SCD during steady state. Consistent with a link between endothelial dysfunction and end-organ disease, we found that higher levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) were associated with markers indicating renal dysfunction and hepatic impairment. Analysis of soluble intercellular cell adhesion molecule-1 (sICAM-1), sE-selectin and sP-selectin levels indicated partially overlapping associations with sVCAM-1, with an additional association with inflammatory stress and triglyceride levels. Importantly, increased soluble adhesion molecule expression correlated with severity of pulmonary hypertension, a clinical manifestation of endothelial dysfunction. Soluble VCAM-1, ICAM-1, and E-selectin were independently associated with the risk of mortality in this cohort. Our data are consistent with steady state levels of soluble adhesion molecules as markers of pulmonary hypertension and risk of death.     

Effects of C-reactive protein on the release of von Willebrand factor, E-selectin, thrombomodulin and intercellular adhesion molecule-1 from human umbilical vein endothelial cells.

Increased levels of various plasma molecules, including C-reactive protein (CRP), and endothelial markers von Willebrand factor (vWF), E-selectin, intercellular adhesion molecule-1 (ICAM-1) and thrombomodulin all predict the development and/or progression of cardiovascular disease. As CRP has been shown to upregulate the expression of adhesion molecules on the surface of human umbilical vein endothelial cells (HUVECs) in vitro, we hypothesized that CRP would induce the release of increased levels of the endothelial markers from HUVECs. Accordingly, recombinant human CRP was added to the culture medium of confluent monolayers of HUVECs at physiological to pathological doses of 1-50 microg/ml for 3-48 h. Markers were measured in supernatants by commercial enzyme-linked immunosorbent assays. We found that increased release of thrombomodulin was induced by 20 and 50 microg/ml CRP after 48 h. Increased ICAM-1 was induced by 50 microg/ml CRP after 24 and 48 h. There was no clear influence of CRP on E-selectin, but 20 and 50 microg/ml CRP inhibited the release of vWF. Our data provide further evidence of a link between increased levels of ICAM-1, thrombomodulin and CRP in atherosclerosis, but they counter reports of a direct, possibly causal, relationship between CRP and increases in E-selectin or vWF.     

Endothelial markers and adhesion molecules in acute ischemic stroke--sequential change and differences in stroke subtype

The progress of a stroke concerns the activation of endothelial cells and platelets. We measured the plasma activities of von Willebrand factor (vWf) and the serum levels of soluble thrombomodulin (sTM) as endothelial markers, and the plasma concentrations of soluble P-selectin (sP-selectin) and soluble E-selectin (sE-selectin) as adhesion molecules during the acute (within 48 h from onset) and subacute (after 1 month from the onset) phases of 52 consecutive patients with acute ischemic stroke and 86 age-matched control subjects. The plasma vWf activities and levels of sP-and sE-selectins in stroke patients were significantly elevated compared with those in controls during both the acute and subacute phases. The serum levels of sTM in stroke patients were significantly higher than those in controls only during the subacute phase. In atherothrombotic infarction, the vWf activities and the levels of sP-selectin, markers for endothelial and platelet activation, remained higher until the subacute phase compared with controls, and the concentrations of sTM, a marker for endothelial injury, were increased during the subacute phase compared with during the acute phase. In lacunar infarction, the levels of sTM and sE-selectin of patients were higher only during the acute phase than controls. These findings suggest that the endothelial cell damage might be maintained until the subacute phase in atherothrombotic infarction, whereas it is remarkable only during the acute phase in lacunar infarction. The evaluation of endothelial markers and adhesion molecules would represent the pathophysiological states of stroke and may provide useful information for the treatment of the ischemic infarction.     

The effects of dipyridamole stress test on plasma levels of soluble adhesion molecules intracellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and L-selectin in patients with ischemic heart disease and patients with syndrome X.

BACKGROUND: Adhesion of activated leukocytes to the endothelium as a result of myocardial ischemia/reperfusion has been shown to be involved in the development of tissue injury. Leukocyte adhesion to the endothelium occurs via adhesion molecules expressed on the surface of both cell types. Upon cell activation these proteins may be released into the circulation and measured in a soluble form. AIM: To verify whether the dipyridamole stress test, performed in patients with ischemic heart disease (IHD) and in patients with syndrome X, modifies plasma levels of the soluble adhesion molecules vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin and L-selectin. METHODS: Plasma levels of the soluble endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin, as well as of the soluble leukocyte adhesion molecule L-selectin, were measured in venous blood samples taken before and 7 min after administration of dipyridamole in patients with IHD, patients with syndrome X and healthy individuals. Myocardial perfusion was evaluated using single photon emission tomography. The plasma levels of soluble VCAM-1, ICAM-1, E-selectin and L-selectin were all measured using enzyme-linked immunosorbent assays. RESULTS: After infusion of dipyridamole, plasma levels of ICAM-1 increased significantly in patients with IHD, whereas they remained unchanged in patients with syndrome X and in the control group. In patients with IHD, the initial plasma levels of VCAM-1, E-selectin and L-selectin, before administration of dipyridamole, were higher than those observed in patients with syndrome X and than those in the control group. Plasma levels of soluble VCAM-1, E-selectin and L-selectin decreased significantly in patients with IHD following the dipyridamole stress test, whereas they remained unchanged in patients with syndrome X, and in the control group. CONCLUSION: In patients with IHD, administration of dipyridamole induces myocardial ischemia resulting in modification of plasma levels of the soluble adhesion molecules.     

The influence of age, gender and ABO blood group on soluble endothelial cell markers and adhesion molecules

The influence of age, gender and ABO blood group on soluble adhesion molecules and markers of endothelial function were tested by measurement of levels of von Willebrand factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1 (VCAM-1), P-selectin, E-selectin and thrombomodulin in venous blood from healthy subjects. Only VCAM-1 showed a significant multivariate correlation with age ( r  = 0.2, P  = 0.019), and thrombomodulin ( P  = 0.0001) and E-selectin ( P  = 0.026) were lower in the women. Significant differences between ABO blood groups were found for von Willebrand factor ( P  = 0.024), E-selectin ( P  < 0.001) and thrombomodulin ( P  < 0.001). As these three are all specific endothelial products, our findings may have implications for vascular biology.     

Platelets and cytokines in concert with endothelial activation in patients with peripheral arterial occlusive disease.

We tested the hypothesis whether circulating oncostatin-M (OSM), a cytokine that in vitro promotes fibrinogen biosynthesis and smooth muscle cell proliferation, or soluble CD40 ligand (CD40L; CD154), a leukocyte and platelet surface marker that stimulates endothelial cells, were associated: (a) with fibrinogen and other soluble cell adhesion molecules, such as P-selectin, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 and platelet-endothelial cell adhesion molecule-1; or (b) with restenosis and platelet activation in 71 patients with peripheral arterial occlusive disease undergoing peripheral angioplasty (PTA). Platelet membrane activation markers (CD62P, CD63, activated GPIIb/IIIa) were immunologically measured at 0, 1, 24 and 48 h, and 3 and 6 months after PTA. Soluble cell adhesion molecules, endothelial markers and various hemostatic variables were measured before PTA. Of the patients, 42.3% developed restenosis within 6 months, defined as a >50% reduction of the lumen at the site of balloon dilatation. Soluble CD40L was not higher in the restenosis group. Interestingly, patients with high CD40L showed significantly higher soluble VCAM-1 (P < 0.01) and thrombomodulin (P < 0.01), as well as trends for higher soluble P- and E-selectin. Platelet activation was found uniformly increased mostly at 1 and 24 h, as well as at 3 and 6 months. OSM was measurable in 53.5% (6.9 +/- 9.4 pg/ml) of the patients and undetectable in the others. No differences in the rate of restenosis was found in these two groups, which did not differ with respect to fibrinogen (3.14 +/- 1.00 versus 3.21 +/- 0.70 g/l), or the other parameters. In conclusion, soluble CD40L is associated with higher endothelial biological markers that might implicate its involvement in endothelial activation. Platelet activation, probably intermittent, might play a significant role through the expression of CD40L as a source of activation signals to the endothelial cells. Free circulating OSM does not seem to correlate directly with fibrinogen or with other acute phase reaction proteins, the synthesis of which it could influence in vitro. This might well not mean, however, that OSM lacks this activity in vivo.     

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.     

Supervised exercise training reduces plasma levels of the endothelial inflammatory markers E-selectin and ICAM-I in patients with peripheral arterial disease

Elevated plasma levels of vascular inflammatory markers have been reported in patients with peripheral arterial disease (PAD). We assessed the effect of supervised exercise training (ET) on vascular inflammation, hypothesizing that ET reduces plasma levels of the endothelial adhesion molecules E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-I (VCAM-I). Twenty-nine patients with PAD underwent a supervised ET program for 8 weeks. Before and after ET, walking distances (pain-free, PWD; maximal, MWD) were determined by a standard treadmill test. Plasma levels of E-selectin and ICAM-I were significantly reduced (E-selectin: 45.5-40.4 ng/mL, P = .013); ICAM-I: 342.0-298.0 ng/mL, P = .016). VCAM-1 levels were unchanged. Walking distances increased significantly (PWD: median 77-150 m, P < .001; MWD: median 306-535 m, P < .001). In conclusion, 8 weeks of ET in patients with PAD reduces plasma levels of the specific endothelium-derived inflammatory markers E-selectin and ICAM-I.     

Early activation of vascular endothelial cells and platelets in obese children

Obesity in adulthood is combined with vascular endothelial cell and platelet activation. In this study we evaluated whether or not such activation is already present in obese children. Forty obese (10.3 +/- 2.5 yr) and 40 nonobese (10.3 +/- 2.3 yr) children were studied. Circulating levels of soluble (s) intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin, as indices of vascular endothelial cell activation, were assessed in both groups. Plasma concentrations of sP-selectin and sCD40 ligand, as indices of platelet activation, were also measured. Circulating levels of highly sensitive C-reactive protein (hs-CRP) and the lipid peroxidation product 8-iso-prostaglandin (PG)F(2alpha) were evaluated because of their ability to promote vascular endothelial cell and platelet activation. Circulating levels of all of the assessed markers were higher in obese than in nonobese children (sICAM-1, +38.8 +/- 13.3%; sVCAM-1, +26.5 +/- 13.7%; sE-selectin, +31.3 +/- 17.3%; sP-selectin, +31.7 +/- 16.9%; sCD40 ligand, +36.9 +/- 22.1%; total 8-iso-PGF(2alpha), +24.0 +/- 20.2%; hs-CRP, +76.6 +/- 12.9%; P < 0.0001). Significant correlations (P < 0.004) between plasma total 8-iso-PGF(2alpha) levels and circulating sICAM-1 (r = 0.485), sVCAM-1 (r = 0.506), sP-selectin (r = 0.449), sCD40 ligand (r = 0.498), and hs-CRP (r = 0.520) concentrations were found in obese children. In conclusion, an early activation of vascular endothelial cells and platelets was present in obese children. Increased lipid peroxidation was also present in these children and likely contributed to the observed proinflammatory phenotype.     

Elevated Levels of Circulating Cell Adhesion Molecules in Uncomplicated Essential Hypertension

Elevated levels of circulating soluble cell adhesion molecules are associated with the development of cardiovascular disease. We tested the hypothesis that circulating levels of soluble cell adhesion molecules are elevated in older men with uncomplicated essential hypertension, which may contribute to the increased risk of atherosclerosis in this population. Circulating levels of soluble intercellular adhesion molecule-1, vascular adhesion molecule-1, and E-selectin were measured in 11 hypertensive (69 ± 1 years) and ten normotensive (65 ± 1 years) older men who were free of overt atherosclerotic disease, diabetes, and dyslipidemia. The hypertensive subjects had higher (P < .05) circulating levels of soluble intercellular adhesion molecule-1 (232.4 ± 16.5 v 189.8 ± 11.1 ng/mL) and vascular adhesion molecule-1 (737.3 ± 65.6 v 565.7 ± 46.8 ng/mL) compared with their normotensive peers. However, there was no difference in the levels of soluble E-selectin between the hypertensive (51.1 ± 3.9 ng/mL) and normotensive (48.8 ± 6.6 ng/mL) subjects. Univariate analysis revealed a positive correlation between soluble intercellular adhesion molecule-1 and both systolic (r = 0.50, P = .02) and diastolic (r = 0.49, P = .03) blood pressure. In addition, soluble vascular adhesion molecule-1 was positively correlated with age (r = 0.60, P = .004) and systolic blood pressure (r = 0.43, P = .05). The results of this study support the hypothesis that circulating levels of soluble cell adhesion molecules are elevated in older men with uncomplicated essential hypertension.     

High insulin exacerbates neutrophil-endothelial cell adhesion through endothelial surface expression of intercellular adhesion molecule-1 via activation of protein kinase C and mitogen-activated protein kinase

Aims/hypothesis. The association of insulin resistance and compensatory hyperinsulinaemia with increased coronary events in diabetic patients is poorly understood. There are few publications about the direct atherogenic actions of insulin on the endothelium compared with those on vascular smooth muscle cells. The aim of this study was to elucidate whether high insulin directly affects neutrophil-endothelial cell adhesion and surface expression of endothelial adhesion molecules. We also examined what intracellular mechanisms are involved in these events. Methods. Studies of adhesion between neutrophils from healthy volunteers and human umbilical vein endothelial cells incubated in insulin-rich medium were carried out. Adhered neutrophils were quantified by measuring their myeloperoxidase activities and surface expression of endothelial adhesion molecules was examined using an enzyme immunoassay. Results. High insulin enhanced neutrophil-endothelial cell adhesion with an increase in the expression of intercellular adhesion molecule-1 but not E-selectin or P-selectin. Both phenomena were attenuated by pretreatment with protein kinase C inhibitors and a mitogen activated protein kinase inhibitor. Conclusions/interpretation. These results suggest that hyperinsulinaemia causes vascular injury by directly exacerbating neutrophil-endothelial cell adhesion through increasing endothelial expression of intercellular adhesion molecule-1 via activation of protein kinase and mitogen activated protein kinase pathways. [Diabetologia (2002) 45: ▪–▪] Received: 5 September 2001 and in revised form: 26 November 2001     

Increased circulating activated endothelial cells,vascular endothelial growth factor,and tumor necrosis factor in thalassemia

An increased number of circulating endothelial cells (CECs) was demonstrated in alpha- and beta-thalassemic patients, beta-thalassemia/hemoglobin E (BE), both splenectomized (BE[S]) and non-splenectomized (BE[NS]), had higher numbers of CECs than alpha-thalassemia, both HbH (alpha-thal l/alpha-thal 2; H) and HbH with hemoglobin Constant Spring (alpha-thal 1/CS; H/CS). CECs were also increased in heterozygous HbE (EA) and homozygous HbE (EE). The highest level of tumor necrosis factor-alpha (TNF-alpha) was found in HbH/CS patients, whereas the highest levels of vascular endothelial growth factor (VEGF) was observed in BE[S] patients. Significant decreases, in protein C and protein S levels were found in both alpha- and beta-thalassemia compared with normal. Good correlations between the numbers of CEC and TNF-alpha, VEGF, protein C, and protein S levels were demonstrated in this study. In addition, markers for endothelial cell activation and injury (intercellular adhesion molecule-1, ICAM-1/CD54; vascular cell adhesion molecule-1, VCAM-1/CD106; and E-selectin, ELAM-1/CD62E) were detected on the surface of isolated CECs using immunofluorescence technique. Appearance of CECs with markers for endothelial cell activation, together with increased levels of TNF-alpha and VEGF and decreased levels of protein C and protein S in the circulation, may account for the propensity of vascular perturbation in thalassemic subjects.     

Enhanced platelet/endothelial activation in depressed patients with acute coronary syndromes: evidence from recent clinical trials.

Platelets play a key role in the progression of acute coronary syndromes (ACS). Clinical depression alone is also associated with enhanced platelet activation. The purpose of this study was to compare concentrations of established biomarkers of enhanced platelet/endothelial activation in clinically depressed versus non-depressed patients enrolled in recent clinical trials for ACS. Two hundred and eighty-one baseline plasma samples from patients with acute myocardial infarction (ASSENT-2; n = 41), with ACS (PRONTO; n = 126) and with clinical depression plus previous acute coronary syndrome within 6 months (SADHART; n = 64), and from normal healthy controls (n = 50) were analyzed. Blood was drawn before applying any therapeutic strategies including interventions, thrombolytics, infusions, and selective serotonin re-uptake inhibitors. Platelet factor 4, beta-thromboglobulin, platelet/endothelial cell adhesion molecule-1, P-selectin, thromboxane, prostacyclin, vascular cell adhesion molecule-1, and E-selectin were measured by enzyme-linked immunosorbent assay by a single core laboratory. Patients with ACS exhibited a higher degree of platelet activation than controls independently of the presence of depression. Plasma levels of P-selectin, thromboxane, prostacyclin, and vascular cell adhesion molecule-1 were the highest in the acute myocardial infarction group when compared with ACS despite the presence or absence of clinical depression. Surprisingly, patients with ACS and depression exhibited the highest levels of platelet factor 4, beta-thromboglobulin, and platelet/endothelial cell adhesion molecule-1 when compared with myocardial infarction or angina patients without clinical depression. E-selectin plasma level was constantly elevated compared with controls but did not differ among the groups dependent on the incidence of depression. The depressed plus ACS group had higher plasma levels of all biomarkers compared with the non-depressed patients. Retrospective analysis of the data from several clinical trials reveals that clinical depression is associated with enhanced activation of platelet/endothelial biomarkers even above the level expected in ACS. These findings may contribute to the unfavorable outcome associated with clinical depression in patients with ACS.     

Soluble intercellular adhesion molecule-1 is related to endothelial vasodilatory function in healthy individuals

OBJECTIVE: To investigate the associations between markers of systemic and vascular inflammation, and indicators of vascular morphology and function. METHODS: In 59 apparently healthy individuals, we measured serum levels of highly sensitive C-reactive protein (hsCRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Endothelium-dependent (EDV) and -independent (EIDV) vasodilatation was evaluated in the forearm by venous occlusion plethysmography and local infusions of methacholine and sodium nitroprussid. Endothelial function index (EFI) was expressed as the EDV/EIDV ratio. The intima-media thickness (IMT) of the common carotid artery was investigated with ultrasound (far wall). RESULTS: EFI was inversely related only to ICAM-1 (r=-0.31, P<0.02) by univariate analysis. This association remained significant after adjustment for age, sex, blood pressure, smoking and serum cholesterol. EFI did not relate to hsCRP, VCAM-1 or E-selectin. Neither hsCRP, nor the adhesion molecules were significantly related to carotid artery IMT. CONCLUSION: ICAM-1 was related to endothelial vasodilatory function, but not to IMT, suggesting that endothelial inflammatory activation is related to an impaired vascular relaxation in apparently healthy individuals.