Elevation of serum soluble E-selectin and VCAM-1 in severe asthma

OBJECTIVE: To investigate the significance of circulating adhesion molecules associated with leucocyte-endothelial cell interactions in asthma, serum levels of soluble E (sE)-selectin, soluble P (sP)-selectin, soluble L (sL)-selectin, and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured in mild, moderate and severe asthma. METHOD: Serum levels of sE-selectin, sP-selectin, sL-selectin, and sVCAM-1 were measured in 32 women with asthma and 30 healthy donors using an enzyme-linked immunosorbent assay method. Twenty patients were suffering from severe asthma, and 12 from mild/moderate asthma. RESULTS: Serum sE-selectin and sVCAM-1 levels from patients with asthma were significantly higher than those observed in healthy donors (p < 0.01). The levels of sP-selectin were the same as those of controls. The level of sE-selectin exhibited an important increase in the severe asthmatic patients compared with mild/moderate asthma (p < 0.01). The sVCAM-1 level was increased in severe asthma when compared with healthy controls. There was no correlation between the levels of soluble selectins and the age of the patients. A significant correlation was found between sE-selectin and sVCAM-1 levels. CONCLUSION: These data indicate that circulating soluble forms of the selectins may have different kinetics during the clinical course of asthma, suggesting that they may reflect different inflammatory pathways in severe asthma. Both sVCAM-1 and sE-selectin may be useful immunological markers for monitoring disease activity in asthma.     

Levels of soluble ICAM-1 in premature and full-term neonates with infection

BACKGROUND: Infection in the neonatal period is an extremely serious condition and diagnosis is difficult. C-reactive protein (CRP) is widely used as a marker of infection; however, its usefulness is limited in the early phase. The role of soluble intracellular adhesion molecule-1 (sICAM-1), an adhesion molecule, has been examined in recent studies as an early marker of neonatal infection with controversial results. AIM: Assessment of sICAM-1 concentrations and correlation with CRP, which is the currently used marker of infection, in order to use sICAM as an early diagnostic tool in neonates suspected for infection METHODS: Blood samples and blood cultures were obtained from two groups of pre-term and full-term neonates with clinical suspicion of infection prior to the initiation of antibiotics. The sICAM-1 and CRP values were compared with the corresponding noninfected ones (n = 10 each). RESULTS: The sICAM-1 levels were found increased in the group of both premature and term neonates with infection compared with the corresponding healthy ones (P < 0.0001). Prematurity combined with infection resulted in excessive increase of the levels of sICAM-1 in comparison with full-term infected newborns (p < 0.001). CRP values were normal in all samples except one in both full-term and premature infected neonates on day 1 of clinically suspected infection. Serial detection of CRP values on days 2 and 4 of infection revealed a pattern according to which CRP values in premature neonates continued rising, while in the group of full terms these values, after rising on the second day, lowered on day 4. CONCLUSIONS: Increased sICAM-1 levels can be detected early in both full-term and premature neonates with sepsis while CRP levels are within normal range at the same time. Assessment of sICAM-1 concentrations may be used as a diagnostic tool in neonates suspected for infection, resulting in earlier initiation of antibiotic therapy and therefore improving their outcome.     

Activin,a Grape Seed-derived Proanthocyanidin Extract,Reduces Plasma Levels of Oxidative Stress and Adhesion Molecules (ICAM-1, VCAM-1 and E-selectin) in Systemic Sclerosis

This study evaluated whether a new generation antioxidant Activin derived from the grape seed proanthocyanidins, could reduce the induction of the adhesion molecules as a result of inflammatory response in the plasma of systemic sclerosis (SSc) patients. SSc patients were divided into two groups: one group was treated with Activin, a grape seed‐derived proanthocyanidins, while the other group served as control. Patients were given Activin 100 mg/day orally for one month after which the blood samples were withdrawn from both groups of the patients. Blood was also taken from normal human volunteers. Plasma was obtained in fasting state between 8 to 9 A.M. from two groups of SSc patients and controls. Soluble adhesion molecules including ICAM‐1, VCAM‐1, E‐selectin and P‐selectin as well as malonaldehyde, a marker for oxidative stress, were measured. The results of our study demonstrated up‐regulation of these soluble adhesion molecules except for P‐selectin, in the plasma of the SSc patients compared to those obtained from human volunteers. Activin significantly attenuated the increased expression of these adhesion molecules. In addition, there was a significant increase in the amount of malondialdehyde formation in the plasma of the SSc patients, which was also attenuated by Activin. The results of this study demonstrated that Activin could reduce the inflammatory response and the oxidative stress developed in SSc patients.     

Borrelia Burgdorferi Upregulates the Adhesion Molecules E-selectin,P-selectin,ICAM-1 and VCAM-1 on Mouse Endothelioma Cells in vitro

In order to obtain more information on processes leading to Borrelia burgdorferi-induced inflammation in the host, we have developed an in vitro model to study the upregulation of cell surface expression of adhesion molecules on endothelial cells by spirochetes. A mouse endothelioma cell line, derived from brain capillaries, bEnd3, was used as indicator population. bEnd3 cells were incubated with preparations of viable, inactivated or sonicated spirochetes and the expression of E-selectin, P-selectin, ICAM-1 and VCAM-1 was monitored by immunocytochemistry and quantified by cell surface ELISA. We show that all three spirochetal preparations are able to upregulate cell surface expression of E-selectin, P-selectin, ICAM-1 and VCAM-1 on bEnd3 cells in a dose-dependent manner. The kinetics of cell surface expression of the individual adhesion molecules in the presence of Borrelia burgdorferi showed maxima at about 50 h of incubation or later; this was distinct from results obtained with sonicated-preparations of Escherichia coli bacteria or with enterobacterial LPS where peak expression was observed between 4 h and 16 h. The fact that Borrelia burgdorferi does not contain conventional LPS suggests that the mode of induction of adhesion molecules on endothelial cells is influenced by the phenotype of bacteria. At the peak of spirochete-induced cell surface expression of adhesion molecules (≈50 h), bEnd3 cells were found to bind cells of a VLA-4⁺ B lymphoma line (L1-2) much more efficiently than untreated control cells. The binding of L1-2 cells to presensitized bEnd3 cells was significantly inhibited (more than 75%) in the presence of monoclonal antibodies to both VLA-4 and its endothelial counterreceptor VCAM-1. These findings demonstrate that Borrelia burgdorferi organisms are able to induce functionally active adhesion molecules on endothelial cells in vitro and suggest that E-selectin, P-selectin, ICAM-1 and VCAM-1 play an important role in the pathogenesis of spirochetal infection.     

Borrelia Burgdorferi Upregulates the Adhesion Molecules E-selectin, P-selectin, ICAM-1 and VCAM-1 on Mouse Endothelioma Cells in vitro

In order to obtain more information on processes leading to Borrelia burgdorferi-induced inflammation in the host, we have developed an in vitro model to study the upregulation of cell surface expression of adhesion molecules on endothelial cells by spirochetes. A mouse endothelioma cell line, derived from brain capillaries, bEnd3, was used as indicator population. bEnd3 cells were incubated with preparations of viable, inactivated or sonicated spirochetes and the expression of E-selectin, P-selectin, ICAM-1 and VCAM-1 was monitored by immunocytochemistry and quantified by cell surface ELISA. We show that all three spirochetal preparations are able to upregulate cell surface expression of E-selectin, P-selectin, ICAM-1 and VCAM-1 on bEnd3 cells in a dose-dependent manner. The kinetics of cell surface expression of the individual adhesion molecules in the presence of Borrelia burgdorferi showed maxima at about 50 h of incubation or later; this was distinct from results obtained with sonicated-preparations of Escherichia coli bacteria or with enterobacterial LPS where peak expression was observed between 4 h and 16 h. The fact that Borrelia burgdorferi does not contain conventional LPS suggests that the mode of induction of adhesion molecules on endothelial cells is influenced by the phenotype of bacteria. At the peak of spirochete-induced cell surface expression of adhesion molecules (≈50 h), bEnd3 cells were found to bind cells of a VLA-4⁺ B lymphoma line (L1-2) much more efficiently than untreated control cells. The binding of L1-2 cells to presensitized bEnd3 cells was significantly inhibited (more than 75%) in the presence of monoclonal antibodies to both VLA-4 and its endothelial counterreceptor VCAM-1. These findings demonstrate that Borrelia burgdorferi organisms are able to induce functionally active adhesion molecules on endothelial cells in vitro and suggest that E-selectin, P-selectin, ICAM-1 and VCAM-1 play an important role in the pathogenesis of spirochetal infection.     

Gene expression of LOX-1, VCAM-1, and ICAM-1 in pre-atherosclerotic mice

To identify markers of the earliest stage of atherosclerosis, endothelial dysfunction, we evaluated the gene expression of lectin-like oxidized-low-density-lipoprotein receptor-1 (LOX-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) in very young pre-atherosclerotic mice. Furthermore, the plasma levels of the soluble VCAM-1 and ICAM-1 were compared to the gene expression profiles. Gene expressions of LOX-1 and VCAM-1 were up-regulated in young apoE^−/− mice, and thus, it seems probable that these genes play a role in pre-atherosclerosis. Contrarily, the gene expression profile of ICAM-1 did not show any apparent differences between the groups, questioning the involvement of this molecule in the early development of atherosclerosis. Plasma levels of sVCAM-1 and sICAM-1 were similar in all mice and did not correlate with the vascular gene expression of the corresponding genes. It therefore seems likely that these circulating markers are not suited to detect early atherosclerosis.     

Soluble form of ICAM-1, VCAM-1, E- and L-selectin in human milk

In breast milk and paired serum from 70 lactating women and 40 of their term, infection-free neonates, on the 2nd and 5th day postpartum slCAM-1, sVCAM-1, sE- and sL-selectin were measured by ELISA and compared with those in 26 healthy adults (controls). Seven infant formulas and fresh milk from five cows were also analyzed. Human colostrum values of slCAM-1, sVCAM-1 (similar to those in maternal and control serum), sE-selectin and sL-selectin (-10 and -100 times lower than in maternal and control serum) were significantly higher than those in milk, while they varied widely. None of the adhesion molecules was detected in fresh cow's milk or infant formulas. Exclusively breast-fed infants showed significantly higher values of slCAM-1 and sL-selectin on the 2nd day of life than those supplemented also with formula. Only slCAM-1 values correlated positively between colostrum and time-matched maternal serum. These findings show in human milk important amounts of slCAM-1 and sVCAM-1 but minimal amounts of sE- and sL-selectin, which could affect the immune system of the neonate.     

Activin,a grape seed-derived proanthocyanidin extract,reduces plasma levels of oxidative stress and adhesion molecules (ICAM-1, VCAM-1 and E-selectin) in systemic sclerosis

This study evaluated whether a new generation antioxidant Activin derived from the grape seed proanthocyanidins, could reduce the induction of the adhesion molecules as a result of inflammatory response in the plasma of systemic sclerosis (SSc) patients. SSc patients were divided into two groups: one group was treated with Activin, a grape seed-derived proanthocyanidins, while the other group served as control. Patients were given Activin 100 mg/day orally for one month after which the blood samples were withdrawn from both groups of the patients. Blood was also taken from normal human volunteers. Plasma was obtained in fasting state between 8 to 9 A.M. from two groups of SSc patients and controls. Soluble adhesion molecules including ICAM-1, VCAM-1, E-selectin and P-selectin as well as malonaldehyde, a marker for oxidative stress, were measured. The results of our study demonstrated up-regulation of these soluble adhesion molecules except for P-selectin, in the plasma of the SSc patients compared to those obtained from human volunteers. Activin significantly attenuated the increased expression of these adhesion molecules. In addition, there was a significant increase in the amount of malondialdehyde formation in the plasma of the SSc patients, which was also attenuated by Activin. The results of this study demonstrated that Activin could reduce the inflammatory response and the oxidative stress developed in SSc patients.     

MCP-1, ICAM-1 and VCAM-1 are present in early aneurysmal dilatation in experimental rats

Recent studies have suggested that inflammation actively participates in ascending aortic aneurysm formation. The aim of the present study was to evaluate the expression changes of adhesion molecules and MMPs in an experimental model of ascending aortic aneurysm induced by ascending aorta banding in Wistar rats. Twelve rats developed aortic dilation after ascending aorta banding treatment, while nine normal animals underwent surgery without banding were used as controls. Light microscope and scanning electron microscope showed that the wall of the ascending aorta became disorganized as well as infiltration by inflammatory cells in aneurysmal rats. By using immunohistochemical techniques, a significant increase in the immunostaining of MCP-1 was observed in the aneurysmal wall as compared to the normal aortic wall. Under similar experimental conditions, we also found that the immunostaining of ICAM-1 and VCAM-1 was markedly increased in the aneurysmal wall. In addition, gelatin zymographic analysis showed that the expression and activities of MMP-2 and MMP-9 were remarkably enhanced in the ascending aorta of ascending aortic aneurysmal rats as compared to normal rats. These results demonstrate that MCP-1, ICAM-1 and VCAM-1 are involved in the pathogenesis of ascending aortic aneurysm and an increase in the immunostaining and activity of MMP-2 and MMP-9 may promote the progression of ascending aortic aneurysm.     

Regional Gene Expression of LOX-1, VCAM-1, and ICAM-1 in Aorta of HIV-1 Transgenic Rats

Background

Increased prevalence of atherosclerotic cardiovascular disease in HIV-infected patients has been observed. The cause of this accelerated atherosclerosis is a matter of controversy. As clinical studies are complicated by a multiplicity of risk-factors and a low incidence of hard endpoints, studies in animal models could be attractive alternatives.

Methodology/Principal Findings

We evaluated gene expression of lectin-like oxidized-low-density-lipoprotein receptor-1 (LOX-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) in HIV-1 transgenic (HIV-1Tg) rats; these genes are all thought to play important roles in early atherogenesis. Furthermore, the plasma level of sICAM-1 was measured. We found that gene expressions of LOX-1 and VCAM-1 were higher in the aortic arch of HIV-1Tg rats compared to controls. Also, the level of sICAM-1 was elevated in the HIV-1Tg rats compared to controls, but the ICAM-1 gene expression profile did not show any differences between the groups.

Conclusions/Significance

HIV-1Tg rats have gene expression patterns indicating endothelial dysfunction and accelerated atherosclerosis in aorta, suggesting that HIV-infection per se may cause atherosclerosis. This transgenic rat model may be a very promising model for further studies of the pathophysiology behind HIV-associated cardiovascular disease.     

Significance of soluble endothelial molecule E-selectin in patients with breast cancer

Increasing evidence suggests that endothelial cells are involved in tumor growth and metastasis. E-selectin, an adhesion molecule specifically expressed or secreted by activated endothelial cells, may enhance tumor angiogenesis and the adhesion of tumor cells to endothelial cells at distant sites. The aim of this study was to assess the relationship between concentrations of circulating soluble E-selectin and clinical, pathological and biological features in patients with breast cancer (BC). sE-selectin concentrations were analyzed by an ELISA method in sera from 113 patients with metastatic BC, 30 patients with primary inflammatory BC, 105 patients with primary non-inflammatory BC, 456 patients with node-negative BC, and 42 healthy controls. sE-selectin in the metastatic BC group was significantly higher than in the healthy control group. In metastatic BC, sE-selectin was significantly higher in patients with liver metastases than in patients without liver metastases. In patients with primary non-inflammatory BC, a negative correlation was found between sE-selectin concentrations and tumoral microvessel count. In overall and disease-free survival studies performed in the node-negative population (median follow-up duration 7.5 years), multivariate analyses demonstrated a prognostic value of sE-selectin and tumor size. This study suggests that endothelial activation might play a role in the development of BC. This role seems not to be related to angiogenesis.     

FK506 suppresses E-selectin, ICAM-1 and VCAM-1 expression on vascular endothelial cells by inhibiting tumor necrosis factor alpha secretion from peripheral blood mononuclear cells

FK506 suppresses activation of T cells; however, it down-regulates E-selectin, ICAM-1 and VCAM-1 expression in inflamed tissues. In this study, we investigated the effect of FK506 on expression of those adhesion molecules on human vascular endothelial cells (HMVEC). Culture supernatant from peripheral blood mononuclear cells (PBMC) stimulated with anti-CD3 plus anti-CD2 antibodies effectively induced the expression of E-selectin, ICAM-1 and VCAM-1 on HMVEC, and treatment with FK506 down-regulated their expression. Culture supernatant contained tumor necrosis factor (TNF) alpha and interleukin (IL)-1beta, which effectively induced adhesion molecules, and FK506 suppressed both cytokine secretions. TNFalpha content in culture supernatant was parallel to the induction of adhesion molecules by the culture supernatant. IL-1beta content was not enough to induce those adhesion molecules. Anti-TNFalpha antibody completely inhibited those expressions. FK506 did not inhibit either TNFalpha- or IL-1beta-induced expression of adhesion molecules, or viability of HMVEC. These results indicate that FK506 suppresses migration of inflammatory cells through the inhibition of TNFalpha secretion from leukocytes.     

LPS-induced IL-6, IL-8, VCAM-1, and ICAM-1 expression in human lymphatic endothelium.

We have previously reported the TLR4 expression in human intestinal lymphatic vessels. In the study here, microarray analysis showed the expression of the TLR4, MD-2, CD14, MyD88, TIRAP, TRAM, IRAK1, and TRAF6 genes in cultured human neonatal dermal lymphatic microvascular endothelial cells (LEC). The microarray analysis also showed that LEC expressed genes of IL-6, IL-8, VCAM-1, and ICAM-1, and the real-time quantitative PCR analysis showed that mRNA production was increased by lipopolysaccharide (LPS). The LPS-induced IL-6, IL-8, VCAM-1, and ICAM-1 production in LEC was suppressed by the introduction of TLR4-specific small interfering RNA, and also by anti-TLR4, nobiletin, and CAPE pretreatment. These findings suggest that LEC has TLR4-mediated LPS recognition mechanisms that involve at least activation of NF-kappaB, resulting in increased expression of IL-6, IL-8, VCAM-1, and ICAM-1. Both the LPS effect on the gene expression and also the suppression by nobiletin and CAPE pretreatment on the protein production were larger in IL-6 and in VCAM-1 than in IL-8 and in ICAM-1 in LEC. The signal transduction of NF-kappaB and AP-1-dependent pathway may be more critical for the expression of IL-6 and VCAM-1 than that of IL-8 and ICAM-1 in LEC.     

ICAM-1 and VCAM-1 mediate endotoxemic myocardial dysfunction independent of neutrophil accumulation

Both intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) have been implicated in neutrophil-mediated lung and liver injury during sepsis. However, the role of these adhesion molecules as well as the contribution of neutrophils in myocardial dysfunction during sepsis remains to be determined. The purpose of this study was to examine the role of ICAM-1, VCAM-1, and neutrophils in lipopolysaccharide (LPS)-induced myocardial dysfunction. Mice were subjected to LPS (0.5 mg/kg ip) or vehicle (normal saline), and left ventricular developed pressure (LVDP) was determined by the Langendorff technique. LVDP was depressed by nearly 40% at 6 h after LPS. Immunofluorescent staining revealed a temporal increase in myocardial ICAM-1/VCAM-1 expression and neutrophils after LPS. Antibody blockade of VCAM-1 reduced myocardial neutrophil accumulation and abrogated LPS-induced cardiac dysfunction. Antibody blockade or absence of ICAM-1 (gene knockout) also abrogated LPS-induced cardiac dysfunction but did not reduce neutrophil accumulation. Neutrophil depletion (vinblastine or antibody) did not protect from LPS-induced myocardial dysfunction. Our results suggest that although endotoxemic myocardial dysfunction requires both ICAM-1 and VCAM-1, it occurs independent of neutrophil accumulation.     

Effect of high glucose concentrations on expression of ELAM-1, VCAM-1 and ICAM-1 in HUVEC with and without cytokine activation

Diabetes mellitus is associated with an increased prevalence of endothelial dysfunction and development of atherosclerotic vascular diseases. We demonstrate here that hyperglycemia results in the expression of adhesion molecules on endothelial cells in vitro. Incubation of human umbilical vein endothelial cells (HUVEC) in a culture medium with 11.0 mM, 16.5 mM and 22.0 mM glucose concentrations induced the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and endothelial-leukocyte adhesion molecule-1 (ELAM-1). This effect was detectable after 24 h incubation of HUVEC with a high glucose concentration. The effect of high glucose concentration on TNF-alpha induced expression of ELAM-1, VCAM-1 and ICAM-1 was negligible, if at all. These results show that even a short-term exposure of endothelial cells (ECs) to high glucose concentration leads to their activation associated with increased expression of adhesion molecules such as ELAM-1, VCAM-1 and ICAM-1.     

1,4-dihydroxyxanthone modulates the adhesive property of endothelial cells by inhibiting intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin

Cell adhesion molecules, particularly intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule (VCAM-1) and E-selectin, play important roles in the recruitment of leukocytes to the site of inflammation. Blocking the expression of these molecules or preventing their interaction with the receptors has been shown to be important in controlling various inflammatory diseases. These cell adhesion molecules are induced on endothelial cells by various proinflammatory cytokines like IL-1beta and TNF-alpha and also by bacterial LPS. We demonstrate here that 1,4-Dihydroxyxanthone (1,4 DHX) inhibits the expression of cell adhesion molecules, such as ICAM-1, VCAM-1 and E-selectin, on endothelial cells in a concentration and time dependent manner. The inhibition by 1,4 DHX is reversible. On further analysis, our results also show that 1,4 DHX inhibits the adhesion of peripheral neutrophils to the endothelial cell monolayers. 1,4 DHX, therefore, could be used as a novel target for controlling various pathological conditions associated with upregulation of endothelial leukocyte adhesion molecules.     

Crosslinking of CD44 on human osteoblastic cells upregulates ICAM-1 and VCAM-1

Cancer-induced cachexia affects most advanced cancer patients. It is characterized by anorexia, profound metabolic dysfunctions, and severe neurological disorders. Here we show that voltage-gated potassium channel (Kv) expression is impaired in the brain of tumor-bearing animals. Expression of both delayed rectifier (Kv1.1, Kv1.2, Kv1.3, Kv1.5, Kv1.6, Kv2.1, Kv3.1, Kv4.2) and A-type potassium channels (Kv1.4, Kv3.3, Kv3.4) was greatly down-regulated in brain from animals bearing a Yoshida AH-130 ascites hepatoma. The possible compensatory mechanisms (Kv1.4/Kv4.2), expression of redundant genes (Kv3.1/Kv3.3) and heteromultimeric channel formation (Kv2.1/Kv9.3) were also affected. The high circulating levels of TNFalpha and the reduced expression of the anti-apoptotic protein Bcl-XL found in the brain of tumor-bearing animals indicate that this response could be mediated by an increase in brain cell death due to apoptosis. The results suggest that brain function is impaired during cancer cachexia, and may account for the cancer-induced anorectic response and other neurological alterations.     

RORalpha1 and RORalpha4 suppress TNF-alpha-induced VCAM-1 and ICAM-1 expression in human endothelial cells

Retinoic acid receptor-related orphan receptor-alpha (RORalpha) is a nuclear orphan receptor. Adenovirus-mediated overexpression of RORalpha1 and RORalpha4 suppressed tumor necrosis factor-alpha (TNF-alpha)-induced expression of vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) in human umbilical vein endothelial cells. Overexpression of RORalpha1 and RORalpha4 also suppressed TNF-alpha-stimulated translocation of p50 and p65 to the nucleus. In contrast, dominant-negative deletion mutants of RORalpha1 and RORalpha4 failed to suppress the induction of VCAM-1 and ICAM-1 and translocations of p50 and p65. These results suggest that RORalpha1 and RORalpha4 regulate the inflammatory responses via inhibition of the nuclear factor-kappaB signaling pathway in endothelial cells.     

Visfatin enhances ICAM-1 and VCAM-1 expression through ROS-dependent NF-kappaB activation in endothelial cells

Visfatin has recently been identified as a novel visceral adipokine which may be involved in obesity-related vascular disorders. However, it is not known whether visfatin directly contributes to endothelial dysfunction. Here, we investigated the effect of visfatin on vascular inflammation, a key step in a variety of vascular diseases. Visfatin induced leukocyte adhesion to endothelial cells and the aortic endothelium by induction of the cell adhesion molecules, ICAM-1 and VCAM-1. Promoter analysis revealed that visfatin-mediated induction of CAMs is mainly regulated by nuclear factor-kappaB (NF-kappaB). Visfatin stimulated IkappaBalpha phosphorylation, nuclear translocation of the p65 subunit of NF-kappaB, and NF-kappaB DNA binding activity in HMECs. Furthermore, visfatin increased ROS generation, and visfatin-induced CAMs expression and NF-kappaB activation were abrogated in the presence of the direct scavenger of ROS. Taken together, our results demonstrate that visfatin is a vascular inflammatory molecule that increases expression of the inflammatory CAMs, ICAM-1 and VCAM-1, through ROS-dependent NF-kappaB activation in endothelial cells.     

Vascular endothelial growth factor expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin through nuclear factor-kappa B activation in endothelial cells

Vascular endothelial growth factor (VEGF) induces adhesion molecules on endothelial cells during inflammation. Here we examined the mechanisms underlying VEGF-stimulated expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin in human umbilical vein endothelial cells. VEGF (20 ng/ml) increased expression of ICAM-1, VCAM-1, and E-selectin mRNAs in a time-dependent manner. These effects were significantly suppressed by Flk-1/kinase-insert domain containing receptor (KDR) antagonist and by inhibitors of phospholipase C, nuclear factor (NF)-kappaB, sphingosine kinase, and protein kinase C, but they were not affected by inhibitors of mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) 1/2 or nitric-oxide synthase. Unexpectedly, the phosphatidylinositol (PI) 3'-kinase inhibitor wortmannin enhanced both basal and VEGF-stimulated adhesion molecule expression, whereas insulin, a PI 3'-kinase activator, suppressed both basal and VEGF-stimulated expression. Gel shift analysis revealed that VEGF stimulated NF-kappaB activity. This effect was inhibited by phospholipase C, NF-kappaB, or protein kinase C inhibitor. VEGF increased VCAM-1 and ICAM-1 protein levels and increased leukocyte adhesiveness in a NF-kappaB-dependent manner. These results suggest that VEGF-stimulated expression of ICAM-1, VCAM-1, and E-selectin mRNAs was mainly through NF-kappaB activation with PI 3'-kinase-mediated suppression, but was independent of nitric oxide and MEK. Thus, VEGF simultaneously activates two signal transduction pathways that have opposite functions in the induction of adhesion molecule expression. The existence of parallel inverse signaling implies that the induction of adhesion molecule expression by VEGF is very finely regulated.