Cilostazol inhibits monocytic cell adhesion to vascular endothelium via upregulation of cAMP

AIM: Cilostazol is clinically used as an inhibitor of platelet aggregation. Although several reports have demonstrated its anti-inflammatory effect, its effect on monocytes and their adhesive interaction to vascular endothelium remains unclear. We thus examined the potential role of cilostazol towards monocyte endothelial interaction under physiological flow conditions. METHODS: THP-1 cells, a monocytic cell line, were pretreated with cilostazol (5 microM) for 48 hours. The cells were then perfused over TNF-alpha (5 microg/mL for 4 hours)-stimulated monolayers of human umbilical vein endothelial cells (HUVECs) at shear stress of 1.0 dyen/cm(2). RESULTS: TNF-alpha-activated HUVECs supported significantly more monocyte adhesion to HUVECs (7.32+/-1.25/HPF) compared to inactivated HUVECs (0.74+/-0.15/HPF), and the amount of adhesion to TNF-alpha-activated HUVECs was markedly reduced (3.63+/-0.55/HPF) when THP-1 cells were incubated in the presence of cilostazol at 5 microM. Interestingly, surface expressions of integrins were not dramatically changed after cilostazol treatment. Intracellular concentration of cAMP was significantly increased after cilostazol treatment, and treatment with Forskolin and Dibutyryl-cAMP, potent inducers of cAMP, dramatically increased THP-1 adhesion to HUVECs. CONCLUSION: These data suggest that cilostazol has a potential anti-inflammatory effect on monocyte-endothelial interactions via the upregulation of intracellular cAMP.     

IL-18 regulates IL-1beta-dependent hepatic melanoma metastasis via vascular cell adhesion molecule-1

Proinflammatory cytokines, including IL-1beta and tumor necrosis factor-alpha (TNF-alpha), promote cancer cell adhesion and liver metastases by up-regulating the expression of vascular cell adhesion molecule-1 (VCAM-1) on hepatic sinusoidal endothelium (HSE). In this study, hepatic metastasis after intrasplenically injected mouse B16 melanoma (B16M) cells was reduced 84-95% in mice with null mutations for either IL-1beta or the IL-1beta-converting enzyme (ICE, caspase-1) compared with wild-type mice. On day 12, 47% of wild-type mice were dead compared with 19% of either IL-1beta or ICE-deficient mice. In vitro, conditioned medium from B16M cells (B16M-CM) induced the release of TNF-alpha and IL-1beta from cultures of primary murine HSE. The effect of B16M-CM on HSE resulted in increased numbers of B16M cells adhering to HSE, which was completely abrogated by a specific inhibitor of ICE, anti-IL-18 or IL-18-binding protein. Exogenous IL-18 added to HSE also increased the number of adhering melanoma cells; however, this was not affected by IL-1 receptor blockade or TNF neutralization but rather by anti-VCAM-1. These results demonstrate a role for IL-1beta and IL-18 in the development of hepatic metastases of B16M in vivo. In vitro, soluble products from B16M cells stimulate HSE to sequentially release TNF-alpha, IL-1beta, and IL-18. The IL-18 cytokine increases expression of VCAM-1 and the adherence of melanoma cells.     

NF- kappa B independent suppression of endothelial vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 gene expression by inhibition of flavin binding proteins and superoxide production

Oxidation-reduction (redox) coupled mechanisms play an important role in the regulation of cell surface adhesion molecule expression. In endothelial cells membrane-bound NADH/NADPH oxidase is a significant source of intracellular superoxide (O(2)(-)) production. We explored the role of flavin containing proteins such as NADH/NADPH oxidase in the induction of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) gene expression in human aortic endothelial cells (HAECs) and human dermal microvascular endothelial cells (HMECs). Treatment of HAECs by tumor necrosis factor- alpha (TNF- alpha, 100 U/ml) for 1 h induced a 31% increase in O(2)(-)production within 5 min as determined by lucigenin chemiluminescence analysis of whole cells (n=4, P<0.05). Pretreatment with the NADH/NADPH oxidase inhibitor diphenylene iodonium (DPI, 40 microm) for 1 h inhibited O(2)(-)production. DPI also inhibited TNF and LPS-induced VCAM-1 and ICAM-1 cell surface expression and TNF- alpha, LPS, or IL-1 beta induced VCAM-1 and ICAM-1 mRNA accumulation. However, DPI did not inhibit TNF- alpha -induced activation of nuclear NF- kappa B-like binding activity in HAECs and HMECs. Furthermore, DPI did not inhibit TNF- alpha induced transactivation of NF- kappa B-driven VCAM-1 and HIV-LTR promoter gene constructs in transiently transfected HMECs. These data suggest that flavin binding proteins such as NADH/NADPH oxidase can regulate VCAM-1 gene expression independent of NF- kappa B. Furthermore, intracellular O(2)(-)generation is not necessary for NF- kappa B activation or for transactivation of NF- kappa B driven promoters.     

胃肿瘤患者循环可溶性细胞间粘附分子-1和血管细胞粘附分子-1

AIM To elucidate the biological and clinical significance of sICAM-1 and sVCAM-1 in patients with gastric cancer.METHODS The serum levels of soluble ICAM-1 and VCAM-1 were measured with sandwith enzyme immunoassay.RESULTS In gastric cancer patients, soluble ICAM-1 and VCAM-1 concentrations were significantly elevated in comparision with those of healthy subjects (289.23μg/L±32.69μg/L vs 190.44μ/L±35.92μg/L,1430.88μg/L±421.71μg/L vs 727.24μg/L±157.68μg/L, respectively, P＜0.01). The increment in serum sICAM-1 and sVCAM-1 concentrations correlated well with the staging of gastric cancer. The serum levels of sICAM-1 and sVCAM-1 in patients of Ⅲ-Ⅳ stages were higher than those of Ⅰ-Ⅱ stages (346.60μg/L±92.10μg/L vs 257.54μg/L±32.77μg/L, 1800.60μg/L±510.76μg/L vs 1262.81μg/L±236.73μg/L). The levels of sICAM-1 and sVCAM-1 were correlated significantly (r=0.49,P＜0.01). The sICAM-1 and sVCAM-1 levels correlated positively with alkaline phophatase (r=0.63,0.71,P＜0.001) and white cell count (r=0.52,0.43, P＜0.01); but correlated negatively with serum albumin (r=-0.41, -0.49, P＜0.01).CONCLUSION The measurement of circulating ICAM-1 and VCAM-1 may bring additional prognostic information for patients with gastric cancer in varying stages.INTRODUCTIONTumor growth and metastasis involves a variety of cell-cell and cell-extracellular matrix interactions mediated by cell adhesion molecules. Currently, a number of cell adhesion molecules, such as intercellular adhesion molecules-1 (ICAM-1), vascular cell adhesion molecules-1 (VCAM-1), etc. have been found.ICAM-1 and VCAM-1 are members of the immunoglobulin supergene family which are cytokine-induced glycoproteins (IL-1, TNFα and IFNγ). Both of them have five or seven extracellular immunoglobulin-like domains, a single transmembranous domain and a short cytoplasmic tail[1,2]. The natural ligand of ICAM-1 or VCAM-1 is LFA-1 (CD11a) and Mac-1 (CD11b) or VLA-4, respectively[3]. ICAM-1 is a widely distributed protein on a variety of tissues, and can be detected in many cells such as macrophage, T- and B-cells, or fibroblasts, endothelial and epithelial cells. VCAM-1 is also a widely distributed protein and is constitutively expressed on tissue macrophage, dentritic cells in lymphoid tissue and skin, as well as on bone marrow fibroblasts and epithelial cells. Expression of VCAM-1 is inducible on vascular endothelial cells under pathological conditions[4].Recently, soluble forms of several adhesion molecules including ICAM-1 and VCAM-1 were found in serum of normal donors[5]. Abnormally high levels of them have been described in some solid malignant tumors, leukemia, autoimmune disease, infectious disease, etc.The present study was carried out to measure the circulating levels of sICAM-1 and sVCAM-1 in gastric cancer before treatment was given and to study their correlation with clinical, histological and routine laboratory parameters.     

Migration inhibitory factor up-regulates vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 via Src, PI3 kinase, and NFkappaB

Cell adhesion molecules are critical in monocyte (MN) recruitment in immune-mediated and hematologic diseases. We investigated the novel role of recombinant human migration inhibitory factor (rhMIF) in up-regulating vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) and their signaling pathways in human MNs. rhMIF-induced expression of VCAM-1 and ICAM-1 was significantly higher compared with nonstimulated MNs. rhMIF induced MN VCAM-1 and ICAM-1 expression in a concentration-dependent manner (P < .05). Antisense oligodeoxynucleotides (ODNs) and inhibitors of Src, PI3K, p38, and NFkappaB significantly reduced rhMIF-induced MN VCAM-1 and ICAM-1 expression (P < .05). However, Erk1/2 and Jak2 were not involved. Silencing RNA directed against MIF, and inhibitors of Src, PI3K, NFkappaB, anti-VCAM-1, and anti-ICAM-1 significantly inhibited rhMIF-induced adhesion of HL-60 cells to human dermal microvascular endothelial cells (HMVECs) or an endothelial cell line, HMEC-1, in cell adhesion assays, suggesting the functional significance of MIF-induced adhesion molecules (P < .05). rhMIF also activated MN phospho-Src, -Akt, and -NFkappaB in a time-dependent manner. rhMIF induced VCAM-1 and ICAM-1 up-regulation in 12 hours via Src, PI3K, and NFkappaB as shown by Western blotting and immunofluorescence. MIF and MIF-dependent signaling pathways may be a potential target for treating diseases characterized by up-regulation of cell adhesion molecules.     

E-selectin and vascular cell adhesion molecule-1 mediate adult T-cell leukemia cell adhesion to endothelial cells

We studied the adhesion properties of peripheral blood leukemic cells from 10 patients with adult T-cell leukemia (ATL) to endothelial cells to better understand the mechanism of leukemic cell infiltration. ATL cells expressed lymphocyte function-associated antigen-1 (LFA-1), but the expression of very late antigen-4 (VLA-4) and sialyl-Lewisx (SLex) was variable. They did not express sialyl-Lewisa (SLea). Cell adhesion assays, which were performed in nine patients, showed marked adhesion of ATL cells to interleukin [IL]-1-activated human umbilical vein endothelial cells (HUVEC). A monoclonal antibody (MoAb) against E- selectin consistently inhibited ATL cell adhesion, and an MoAb against vascular cell adhesion molecule-1 (VCAM-1) or an MoAb against VLA-4 sometimes diminished it. In contrast, an MoAb against LFA-1 had a minor effect on freshly isolated ATL cell adhesion to HUVEC. The percentage of SLex+ cells in the cell population adherent to IL-1-activated HUVEC was slightly higher than that in unseparated cells. These results, together with the detection of E-selectin expression on the endothelium at ATL skin lesions, indicate that E-selectin-mediated adhesion is the major pathway for the adherence of ATL cells to endothelial cells. In addition, the ligand for E-selectin on ATL cells appears to differ from that on neutrophils.     

血清SICAM-1、SVCAM-1表达与代谢综合征及其组分的关系

目的探讨血清可溶性细胞间黏附分子1（SICAM-1）和可溶性血管细胞黏附分子1（SVCAM-1）水平与代谢综合征（MS）及其组分的关系。方法将108名体检者按是否具有MS及其组分分组，并按具有MS组分的个数分组，采用酶联免疫吸附法检测血清SICAM-1和SVCAM-1水平，并与糖脂代谢指标及HOMA-IR作相关性分析。结果具有MS及其组分者SICAM-1、SVCAM-1水平分别较无MS及其组分者明显升高，而且随着MS组分数目增加，SICAM-1、SVCAM-1水平亦明显升高。结论SICAM-1、SVCAM-1均与糖脂代谢指标及HOMA—IR相关。MS组分的累积加重了血管内皮功能障碍，血管内皮功能障碍可能参与了MS的发生与发展。     

Alpha 4 beta 1-integrin expression on sickle reticulocytes: vascular cell adhesion molecule-1-dependent binding to endothelium

Important complications in sickle cell anemia occur secondary to vascular occlusion, which is postulated to be initiated by interactions of erythrocytes with vascular endothelial cells. In patients with sickle cell anemia, up to 25% of reticulocytes express the alpha 4 beta 1-integrin complex. Furthermore, erythrocytes from patients with sickle cell anemia bind to endothelial cells activated by tumor necrosis factor alpha via (TNF alpha) via interactions between erythrocyte alpha 4 beta 1 and endothelial cell vascular cell adhesion molecule-1 (VCAM- 1). Thus, binding of alpha 4 beta 1-expressing reticulocytes to cytokine-activated endothelial cells may initiate vascular complications in sickle cell anemia and perhaps other hemolytic anemias during episodes of infection and inflammation.     

Levels of serum vascular cell adhesion molecule-1 in measles

While the levels of serum vascular cell adhesion molecule-1 (VCAM-1) have been investigated in many diseases, they have not, to our knowledge, been studied in patients with measles. Serum VCAM-1 and creatinine levels were determined in six adolescent and adult Japanese patients with measles in the acute febrile phase and defervescent afebrile phase. Serum VCAM-1 levels were significantly higher in the acute febrile phase than in the convalescent afebrile phase, but no significant difference between the serum creatinine levels was shown in the two phases. Our study revealed that the high serum VCAM-1 level in the acute febrile phase later decreased in the afebrile convalescent phase. The measurement of circulating VCAM-1 may be useful for the assessment of convalescence in patients with measles.     

Vascular cell adhesion molecule-1 augments adenovirus-mediated gene transfer

We have reported that adenovirus-mediated gene transfer is augmented in the endothelium of atherosclerotic blood vessels. We observed that vascular cell adhesion molecule-1 (VCAM-1) shares some homology with the coxsackievirus and adenovirus receptor. Because VCAM-1 is upregulated on atherosclerotic endothelial cells, we hypothesized that VCAM-1 may act as an auxiliary receptor to augment adenovirus-mediated gene transfer. To test this hypothesis, stable NIH 3T3 cell lines that constitutively express VCAM-1 on the cell surface were generated. Recombinant adenovirus 5 (Ad5), which contains the reporter ss-galactosidase gene, was used to compare Ad5 infection in VCAM-1(+) and parental NIH 3T3 cells. Total ss-galactosidase activity and the number of transgene-positive cells were 6- to 10-fold and 5-fold higher, respectively, in VCAM-1(+) than in VCAM-1(-) cells. Ad5 binding to VCAM-1(+) cells was increased by 3-fold over VCAM-1(-) cells. Soluble VCAM-1 protein, present during infection or viral binding, reduced ss-galactosidase activity in VCAM-1(+) cells in a dose-dependent manner. Taken together, we conclude that VCAM-1 can mediate adenovirus binding and infection. This may explain, in part, the previous finding that adenovirus-mediated gene transfer is augmented in atherosclerotic arteries.     

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.     

Soluble intercelluar adhesion molecule-1, E-selectin, vascular cell adhesion molecule-1 and von Willebrand factor in stroke.

We investigated the role of endothelial cell and leukocyte adhesion in the pathophysiology of acute stroke. The immunocytochemical expression of adhesion molecules in brain tissue from six patients who died following acute ischaemic stroke showed weak endothelial expression of intercellular adhesion molecule-1 (ICAM-1), but intense expression of vascular cell adhesion molecule-1 (VCAM-1) by astrocytes and endothelial cells from the infarcted, but not the non-infarcted areas. We also measured soluble adhesion molecules E-selectin, ICAM-1, VCAM-1 and von Willebrand factor (all by enzyme-linked immunosorbent assay) in 21 patients after an acute ischaemic stroke (ictus < 12 h), and again 3 months later. Blood levels in the stroke patients were compared with 82 healthy controls and 22 subjects with carotid atherosclerosis. Compared with healthy controls, both patient groups had raised levels of von Willebrand factor (P < 0.02) but the level of soluble VCAM-1 was raised only in patients with acute stroke (P < 0.02). Levels of von Willebrand factor and soluble VCAM-1 in the stroke patients were still high at 3 months follow-up. We suggest that there might be changes in adhesion molecule expression and release in the acute and chronic stages of ischaemic stroke, where blood levels are related to immunocytochemical findings on infarcted brain. These changes may perhaps be part of the complex pathophysiological responses to infarction and repair of brain tissue following stroke.     

糖尿病患者血清可溶性细胞间粘附分子-1和可溶性血管细胞粘附分子-1变化的研究

目的　研究糖尿病患者血清可溶性细胞间粘附分子 - 1(s ICAM- 1)和可溶性血管细胞粘附分子 - 1(s VCAM- 1)水平的变化。方法　应用酶联免疫吸附法 (EL ISA)检测了 18例 1型糖尿病和 47例 2型糖尿病患者及 2 0例健康对照者的血清 s ICAM- 1、s VCAM- 1以及甘油三酯 (TG)水平。结果　 1血清 s ICAM- 1和 s VCAM- 1水平 ,1型、2型糖尿病患者组均显著高于健康对照组 (P<0 .0 5～ 0 .0 1) ,2型糖尿病有微血管病变组又高于无微血管病变组 (P<0 .0 5～ 0 .0 1) ,1型糖尿病与 2型糖尿病组之间无显著性差异 ;2血清 s VCAM- 1水平 ,2型糖尿病的高甘油三酯血症组 (A组 )、高甘油三酯血症合并高血压组 (B组 )高于单纯高血压组 (C组 )和甘油三酯、血压正常组 (D组 ) (P均 <0 .0 5 ) ;3 1型糖尿病和 2型糖尿病患者血清 s ICAM- 1和 s VCAM- 1之间均呈正相关关系 (r=0 .83、0 .5 3,P均 <0 .0 1)。结论　 12型糖尿病患者血清 s VCAM- 1升高与高甘油三酯血症有关 ;2血清 s ICAM- 1和 s VCAM- 1参与了糖尿病微血管病变的发病过程 ,并可作为糖尿病病情变化的监测指标     

动脉粥样硬化兔血清中血管细胞黏附分子-1的表达及其与血脂相关性的研究

目的观察动脉粥样硬化（AS）兔血清中血管细胞黏附分子-1（VCAM-1）的表达及其与血脂的相关性,探讨VCAM-1与AS的关系.方法雄性大耳白兔随机分成正常饮食组和高脂饮食组,每组8只,饲养16 w.于0 w、8 w、16 w分别取耳缘静脉血,检测血清中胆固醇（TC）、低密度脂蛋白（LDL）水平及VCAM-1的表达;16 w后处死动物,取兔主动脉进行病理学检查,确认AS模型的建立.结果正常饮食组动脉壁无异常改变;高脂饮食组AS斑块病变形成.正常饮食组0 w、8 w、16 w血清中TC、LDL及VCAM-1水平无显著差异（P＞0.01）;高脂饮食组8 w后血清中TC、LDL及VCAM-1水平较0 w显著增加（P＜0.01）,16 w较8 w增加更为明显（P＜0.01）.结论AS的发生伴有VCAM-1的过度表达,其表达量与血清TC、LDL呈正相关.     

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.     

siRNA silencing reveals role of vascular cell adhesion molecule-1 in vascular smooth muscle cell migration

Vascular cell adhesion molecule-1 (VCAM-1) is an adhesion molecule expressed by endothelial cells for recruitment of leukocytes during inflammation. It is also abundantly expressed by smooth muscle cells in atherosclerotic lesions and in injured arteries. In this study, we examined the role of VCAM-1 in smooth muscle cell migration. Smooth muscle cells were isolated from the aorta of C57BL/6 mice and transfected with short interfering RNAs (siRNAs) targeting VCAM-1. Inhibition on VCAM-1 expression by siRNAs was assessed by Western blot analysis, RT-PCR and by measuring soluble VCAM-1 concentrations in the incubation medium. One siRNA that showed greater suppression on VCAM-1 expression was used for migration assay. A single scratch wound was made on 70% confluent cells and cells migrated from wounded monolayer were counted 24 and 48h after injury. Treatment with VCAM-1 siRNA resulted in a significant reduction in the number of migrated cells. This siRNA also exhibited a minor effect on smooth muscle cell proliferation. Thus, our findings indicate that VCAM-1 is necessary for the migration of smooth muscle cells and interfering VCAM-1 expression could be an effective approach to prevention and treatment of atherosclerosis and restenosis.