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1.
IGF-I is a ubiquitous growth factor, found in platelets and elaborated by many other cell types. It is thought to be involved in several pathophysiological processes including embryonic development, angiogenesis and wound healing. We report that the adherence of human peripheral blood monocytes to an endothelial cell line (EAhy 926) is inhibited in a dose and time-dependent manner by pre-incubating the endothelial cells with IGF-I ( P  < 0.001). Monocyte adhesion was inhibited 17.9 ± 1.9% by IGF-I at a dose of 1000 ng/ml ( P  < 0.01). In contrast, IGF-I had no significant effect on monocyte adherence to plastic. The inhibitory effects of IGF-I were reversed by co-incubating the endothelial cells with the nitric oxide synthase inhibitor, L-NAME. These data suggest that the effects of IGF-I are mediated by the release of nitric oxide from the endothelial cells.  相似文献   

2.
Prostacyclins have long been shown to have anti-metastatic activity. One hypothesis is their modulation of cell adhesion molecule (CAM) expression by target organ endothelial cells. We have postulated that prostacyclin, its analogs, and mechanistic mimics decrease colon carcinoma adhesion to cytokine-stimulated endothelial cells by blocking endothelial expression of the adhesion molecule E-selectin, but not the vascular cell adhesion molecule-1 (VCAM-1). Cultured human microvascular endothelial cells (HDMEC) were pre-incubated with prostacyclin (PGI2), dibutyrl-CAMP (dbcAMP), forskolin (FOR), and/or iso-methylbutylxanthine (IBMX) for 15 min, then co-incubated with the cytokine tumor necrosis factor (TNF) for 4 h. HDMEC surface expression of E-selectin and VCAM-1 was evaluated by flow cytometry and ELISA. Adherence of 51Cr-labeled colon carcinoma cells to HDMEC monolayers was then determined. In parallel assays, HDMECs were incubated with anti-E-selectin and anti-VCAM-1 monoclonal antibody (1:100) prior to the addition of tumor cells. Prostacyclins, its analogs, and mimics significantly reduced E-selectin expression by HDMEC, while the reduction of VCAM-1 expression was much less pronounced. Prostacyclins also significantly decreased colon carcinoma adherence to stimulated HDMECs. The inhibition of E-selectin expression, but not VCAM-1 expression, corresponded to the reduction of tumor cell adherence. Prostacyclin's effects on tumor adhesion were nullified by pre-incubation with E-selectin antibody. The inhibition of colon carcinoma adherence to cytokine-stimulated endothelial cells treated with prostacyclin, its analogs, and mimics appears to result from blocking endothelial E-selectin, but not VCAM-1, expression. These data support the hypothesis that prostacyclins may exert their anti-metastatic effect, in part, by inhibiting CAM-mediated adherence of colon carcinoma to endothelial cells in metastatic target organs.  相似文献   

3.
Mikkola TS  St Clair RW 《Maturitas》2002,41(4):796-319
OBJECTIVE: To investigate the effect of 17beta-estradiol (E2) on binding of monocytes to human aortic endothelial cells (HAECs) with or without cytokine induction. METHODS: Confluent monolayers of HAECs were incubated with or without E2 for 48 h prior to the monocyte adhesion assay. In studies with cytokines, 1 ng/ml tumor necrosis factor-alpha (TNF-alpha), 20 U/ml interleukin-1beta (IL-1beta) or both were added to the culture medium for the final 24 or 4 h. For the measurement of monocyte adhesion, 3H-thymidine labeled human THP-1 monocytes (4 x 10(5) cells per well) were added to the confluent monolayer of HAECs and incubated at 37 degrees C for 90 min. The unbound THP-1 cells were removed by gentle washing, and bound cells were digested with NaOH and quantified by measuring radioactivity. RESULTS: When HAECs were pretreated for 48 h with E2 the basal adhesion of THP-1 cells was reduced by an average of 28%. Estrogen significantly reduced cytokine-induced adhesion by 30-35% when the cytokines were added for 4 h. When the cytokine treatment was prolonged to 24 h, pretreatment of HAECs with E2 had no effect on THP-1 cell adhesion. CONCLUSIONS: E2 reduces basal and short-term cytokine induced monocyte binding to HAECs. Since monocyte adhesion to vascular endothelial cells is one of the initial steps in the pathogenesis of atherosclerosis, E2 may mediate vascular protection by reducing monocyte-endothelial cell binding in the early stages of atherogenesis.  相似文献   

4.
The object of our study was the question about the relevance of the tumor surrounding inflammatory cells with respect to the metastatic potential of the tumor cells. To imitate the role of inflammatory cells, three colon carcinoma (HT-29, HRT-18, and SW-620), one breast carcinoma (MCF-7), and one melanoma (ST-ML-12) cell lines were treated with pro-inflammatory stimuli, LPS, TNF-alpha, or IL-1beta. HUVEC monolayers were then stimulated by the collected supernatants (SN) of the tumor cells, following washing out of the applied stimuli. Analysis of CAM expression on HUVEC was performed using cell enzyme immunoassay. E-selectin, VCAM-1, and, in part, ICAM-1 were significantly up-regulated on HUVEC by exposure to SN of all LPS-stimulated tumor cells. This was especially the case for the colon carcinoma cell lines. A minimal increase of expression of VCAM-1 was observed after exposure to SN from TNF-alpha-stimulated HT-29 and MCF-7 cells. IL-1beta stimulation had no effect on endothelial CAM expression. These observations indicate that LPS could play a crucial role in tumor metastasis by inducing the release of soluble factors from different tumor cell lines capable of up-regulating CAM expression. This might be of special significance in colon carcinomas, where a large source of bacterial LPS is available in the intestinal lumen.  相似文献   

5.
Expression of adhesion molecules on endothelial cells (EC) can be up-regulated or induced by cytokines. The aim of the present study was to investigate the effect of IL-4 on both the expression of adhesion molecules on EC and monocyte adhesion to EC. Flow cytometric analysis showed that VCAM-1 expression on EC was up-regulated after stimulation with IL-4 for 24 h, whereas the expression of E-selectin (formerly called endothelial leucocyte adhesion molecule-1 (ELAM-1)) was not enhanced, and that of intercellular adhesion molecule-1 (ICAM-1) only slightly. The adhesion of monocytes to EC increased to maximum values upon stimulation of EC with IL-4 for 24 h. Coating of monocytes with MoAb against the integrin beta 2-subunit (CD18) significantly inhibited their adhesion to IL-4-stimulated EC; maximal inhibition was found when monocytes were coated with anti-CD18 MoAb in combination with MoAb against CD49d (the alpha-chain of VLA-4), whereas no inhibition was found when monocytes were coated only with MoAb against CD49d. Monocyte adhesion was not significantly inhibited when IL-4-stimulated EC were coated with MoAbs against ICAM-1 or VCAM-1 alone or in combination. Adhesion of monocytes was inhibited to a greater extent when in addition to coating of monocytes with MoAb against CD18 the EC were coated with MoAb against VCAM-1. From these results we conclude that monocytes bind to IL-4-stimulated EC via interaction of CD11/CD18 molecules on the monocytes with an as yet unknown endothelial ligand, and interaction of VLA-4 on monocytes with VCAM-1 on EC.  相似文献   

6.
Studies on monocyte adhesion are frequently limited by spontaneous changes of CD11b and CD62L during cell purification. Most isolation protocols for flow cytometric analysis that overcome this problem cannot be used when large numbers of living cells are needed for functional adhesion assays. This study investigated whether magnetic cell separation of monocytes with a paramagnetic bead against CD33 is a feasible method combining high yield with a low degree of spontaneous activation. As determined by flow cytometry, isolation of magnetically tagged monocytes at 4 degrees C did not alter the expression of CD11b and CD62L when compared to whole blood controls. Warming the cells slowly to room temperature immediately before starting the adhesion assay in a parallel plate flow chamber at 37 degrees C prevented further upregulation of adhesion molecules due to rewarming. When adhesion of magnetically tagged monocytes was compared with untouched monocytes that had been isolated via depletion of contaminating leukocytes, videomicroscopy showed that labelling CD33 neither affected rolling nor firm adhesion to human umbilical venous endothelial cells under flow. Finally, the subsequent upregulation of tissue factor expression on adherent monocytes indicates that magnetically separated monocytes responded properly to activating stimuli during cell adhesion. We conclude that magnetic cell separation via CD33 represents a feasible method for cell separation whenever large numbers of non-activated monocytes are needed for adhesion assays under flow.  相似文献   

7.
Adhesion of tumor cells to endothelium via cell-adhesion molecules constitutes a crucial step in metastasis, which is largely responsible for the poor prognosis of small-cell lung carcinoma (SCLC). Patients with SCLC were reported to have elevated levels of intercellular adhesion molecule-1 (ICAM-1). The present study therefore focusses on endothelial ICAM-1 in tumor-cell adhesion. We found that the adherence of SCLC cells (cell lines H24, H69, H82) to cultured vascular endothelium in stasis and flow depends on the expression of ICAM-1. After blocking endothelial ICAM-1 with monoclonal antibodies, adhesion was significantly reduced. These results pinpoint ICAM-1 for the first time as a molecule crucially involved in SCLC cell-endothelial adhesion.  相似文献   

8.
During an inflammatory reaction, an increased number of circulating monocytes adhere to the endothelial cells (EC) of the vessel wall. This process is mediated by molecules located on the surface of monocytes and EC. Locally released inflammatory mediators can modulate monocyte-EC interaction. In an earlier study we reported that stimulation of monolayers of cultured venous EC with rIFN-gamma enhanced their adhesiveness for monocytes. The aim of the present study was to investigate the effect of rIFN-gamma on peripheral blood monocytes with regard to the expression of surface molecules and the binding to non-stimulated or cytokine-stimulated EC. Flow cytometric analysis demonstrated that monocytes stimulated with 500 U/ml rIFN-gamma for 24 h showed increased expression of CR3 (CD11b/CD18), p150,95 (CD11c/CD18) and Fc gamma RI (CD64); the expression of LFA-1 (CD11a/CD18), L-selectin, CD14 and VLA-4 (CD49d/CD29) did not change or was slightly reduced. Upon stimulation with rIFN-gamma monocytes showed an enhanced binding to both non-stimulated or rIFN-gamma-stimulated EC. This was even more pronounced when EC had been stimulated with rIL-1 alpha for 24 h. The increased binding of rIFN-gamma-stimulated monocytes to rIL-1 alpha-stimulated EC was further analysed. Studies with MoAbs against adhesion molecules on monocytes revealed that the binding of rIFN-gamma-stimulated monocytes, but not that of non-stimulated monocytes, to rIL-1 alpha-stimulated EC was inhibited by about 30-60% with MoAbs against CD11a, CD11b, CD18, L-selectin or CD14. MoAbs against CD11c or CD49d had little or no effect. From these results, we conclude that exposure of monocytes to rIFN-gamma enhances their adhesiveness to cytokine-stimulated EC by a mechanism which involves CD11a/CD18, CD11b/CD18, CD14 and L-selectin on monocytes.  相似文献   

9.
To investigate the binding properties of dendritic cells (DC) to vascular endothelium, a comparative analysis was undertaken of DC, monocytes and lymphocytes isolated from the blood of 25 healthy subjects using monolayers of human umbilical vein endothelial cells as the adherence substrate. More blood DC (mean 24% adherence) were adherent to endothelial monolayers than monocytes (mean 18%; P < 0.001) and lymphocytes (mean 12%; P < 0.001). When the monolayers were pretreated with tumour necrosis factor-alpha (TNF-α) all leucocyte populations exhibited an increased attachment, but there was still greater binding of DC (mean 37% adherence) in comparison with monocytes (mean 23%; P < 0.001) and lymphocytes (mean 18%; P < 0.001). Flow cytometric analysis revealed that in relation to monocytes and lymphocytes the DC had a higher surface expression of the adhesion molecules CD11a (P < 0.05), CD11c (P < 0.05) and CD54 (P < 0.05) but a lower prevalence of cells bearing CD49d (mean 38%; P < 0.05) and the homing receptor CD62L (mean 14%; P < 0.001). CD1a was present on 22% of DC and virtually absent from the surface of monocytes and lymphocytes. The intensity of expression of the β1-integrins, CD49c, CD49d and CD49e was greater on DC than lymphocytes and monocytes (P < 0.05). Antibody blocking studies demonstrated that DC binding to untreated and TNF-α-treated endothelium was dependent upon the expression of CD11a, CD18 and CD49d, and the simultaneous application of anti-CD18 and anti-CD49d antibodies produced an approximate 70% inhibition of adhesion (P < 0.001). Thus, the expression of both β1- and β2-integrins contributes to the adhesive interaction between DC and endothelium.  相似文献   

10.
We have analyzed mechanisms controlling infiltration of T lymphocytes into tumor tissues. A lymphocyte chemotactic factor-b (LMF-b) produced by tumor infiltrating CD4+ T lymphocytes was purified. LMB-b was specifically chemotactic for CD8+ T lymphocyte. Furthermore, LMF-b augmented lymphocyte adhesion to high endothelial venule (HEV) cells. The binding of CD8+ T cells to HEV cells was specifically augmented by LMF-b. The LMF-b primarily acted on T lymphocytes, whereas tumor necrosis factor as well as IFN-gamma acted on HEV cells or fibroblast cells. The binding of lymphocytes to fibroblast cell line was not augmented by LMF-b. The augmentation of lymphocyte adhesion to endothelial cells by LMF-b was mediated by the lymphocyte function associated antigen-1/intercellular adhesion molecule (LFA-1/ICAM) pathway, the CD2/LFA-3 pathway, and the very late antigen-4/culture supernatant-1 (VLA-4/CS-1) pathway.  相似文献   

11.
We studied the effect of hypoxia on activation and stimulation of apoptosis in cultured endothelial cells. The effect of hypoxia was compared to that of apoptosis-inducing agents (tumor necrosis factor and bacterial lipopolysaccharide). Incubation of endothelial cells for 24 h under hypoxic conditions (2% O2, 5% CO2, and 93% N2) increased secretion of von Willebrand factor, but had no effect on the expression of cell adhesion molecule ICAM-1. Tumor necrosis factor and lipopolysaccharide did not stimulate secretion of von Willebrand factor, but significantly increased the expression of ICAM-1. These data attest to significant differences in the mechanisms of endothelium activation under hypoxic conditions and during treatment with tumor necrosis factor or lipopolysaccharide. Hypoxia stimulated apoptosis in endothelial cells, which was seen from the increase in the number of annexin V-binding cells and activation of caspase-3. Similar changes were revealed in the presence of tumor necrosis factor and lipopolysaccharide. Hence, damage to endothelial cells caused by hypoxia and these compounds is mediated by similar mechanisms. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 144, No. 10, pp. 384–386, October, 2007  相似文献   

12.
13.
PROBLEM: In intrauterine infection, inflammatory mediators may be released into the fetal circulation prior to fetal infection. We hypothesize that, in chorioamnionitis, inflammation alters fetal blood vessels. To test this, fetal endothelial cells were examined for vascular cell adhesion molecule (VCAM). METHOD OF STUDY: Umbilical cords (n = 9) from placentas with chorioamnionitis were immunostained for VCAM. Controls from preterm preeclamptic pregnancies (n = 7) without histologic inflammation were selected, and matched for gestational age and method of delivery. VCAM sections were reviewed by a pathologist blinded to clinical diagnoses. RESULTS: All endothelial cells from each of the nine cords from placentas with chorioamnionitis had strong VCAM staining. Two of nine samples also had acute cord vasculitis. No cord endothelial cells from preeclamptic placentas demonstrated similar VCAM staining (p < 0.01). CONCLUSION: Histologic chorioamnionitis was associated with VCAM expression of the umbilical cord vessels. In chorioamnionitis, inflammatory mediators may have entered the fetal circulation to activate endothelial cells. Intrauterine inflammation was not restricted to the chorioamnion, but also involved the fetal circulation.  相似文献   

14.
We investigated whether interferon-gamma (IFN-gamma), interferon-alpha (IFN-alpha) and glucocorticoids affected the adhesion of T cells to human umbilical endothelial cells or human synovial cells. About 30% of peripheral blood T cells could bind to unstimulated endothelial cells, but only a few T cells could bind to unstimulated synovial cells. When both endothelial cells and synovial cells were cultured with recombinant IFN-gamma (rIFN-gamma), the percentage of T cell binding to both types of cells increased in a dose-dependent manner. rIFN-alpha and dexamethasone blocked the T cell binding to unstimulated endothelial cells. Furthermore, rIFN-alpha and dexamethasone suppressed T cell binding to both endothelial cells and synovial cells stimulated by IFN-gamma, and also inhibited intercellular adhesion molecule-1 (ICAM-1) expression on both endothelial cells and synovial cells stimulated by IFN-gamma. These results suggest that IFN-alpha and glucocorticoids may inhibit T cell binding to endothelial cells or synovial cells by modulating adhesion molecule expression on these cells.  相似文献   

15.
Human decidua exhibits a unique infiltrate of large granularlymphocytes (LGL) with a natural killer (NK) cell phenotype(CD56++, CD16–, CD3–). The mechanisms underlyingthe binding of circulating LGL to vascular endothelium in thedecidua and their migration into the decidual stroma were investigatedimmunohistochemically in first-trimester decidua with antibodiesagainst endothelial adhesion molecules and their counter-receptorson leukocytes. Decidual and peripheral blood LGL were also investigatedby flow cytometry. In the immunohistochemical investigations,moderate to large numbers of lymphoid cells in the decidua werefound to express the 4 and L integrin subunits, platelet endothelialcell adhesion molecule (PECAM) and intercellular adhesion molecule-1(ICAM-1). PECAM and ICAM-1 were found on the endothelium oflarge numbers of decidual blood vessels of all types. Vascularcell adhesion molecule (VCAM), however, was found on the endotheliumof only small to moderate numbers of arterioles and venulesand a few capillaries, the latter being the main site of migrationof leukocytes into the stroma. Weak staining for endothelialleukocyte adhesion molecule (ELAM) was seen only in a moderatenumber of blood vessels. Flow cytometry revealed expressionof the L integrin subunit by 72 ± 10% and 97 ±3% of decidual and peripheral blood CD56+ LGL, respectively,of the 4 integrin subunit by 85 ± 7% and 90 ±5%, of PECAM by 40 ± 12% and 30 ± 15%, and ofICAM-1 by 22 ± 10% and 1 ± 1%. These findingssuggest that interaction between the integrin 2L and ICAM-1is the more important mechanism of binding to endothelium inthe migration of CD56+ LGL out of the peripheral blood intothe decidua.  相似文献   

16.
A static adhesion assay employing 6-carboxy-3,6-diacetylfluorescein (6-CFDA) as a fluorescent marker has been developed to study the interactions of tumour cell lines with endothelial monolayers. This assay allows simple, safe quantification of cell-cell adhesion using living cells. It has been used to demonstrate that the integrin adhesion molecule VLA-4 mediates the attachment of RPMI-7951 melanoma cells to human umbilical vein endothelial cells (HUVEC) which have been activated by TNF. In addition, MDA-MB-231 breast adenocarcinoma cells display greater adhesion to microvessel endothelial cells than to large vessel endothelial cells.  相似文献   

17.
We recently developed a method for the isolation and purification of tumour-derived endothelium. In this study the phenotypic and functional properties of human tumour-derived microvascular endothelial cells (TdMEC) were examined. Endothelium obtained from human adrenal gland specimens (HAMEC) was used as a reference microvascular endothelial cell population. TdMEC formed a confluent monolayer with the typical morphological appearance of endothelium and were positive for endothelial markers such as Ulex-1 lectin, CD31 antigen, von Willebrand Factor and VE-cadherin. The addition of acidic Fibroblast Growth Factor (aFGF), basic FGF (bFGF) or Vascular Endothelial Growth Factor (VEGF) substantially improved proliferation of TdMEC; and kidney carcinoma derived endothelial cells were more responsive to FGFs, whereas glioblastoma derived endothelial cells greatly responded to VEGF. TdMEC expressed high levels of the VEGF receptors, KDR/flk-1 and Flt-1, as shown by northern blot analysis. TdMEC expressed the adhesion molecules ICAM-1, VCAM-1 and E-selectin that could be further increased by exposing TdMEC culture to interleukin-1. All the TdMEC expressed interleukin-8 mRNA. These findings show that TdMEC in vitro maintain several of the features described for microvasculature. Thus, TdMEC represent a useful tool to study markers for tumor vasculature. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
Interactions of tumor cells with the endothelium and tissue stroma are considered to be critical steps in metastasis formation and progression of cancer. To identify cellular receptors that mediate the binding of tumor cells to endothelium, a murine T cell lymphoma-derived expression library was screened for adhesion-inducing cDNA clones. We identified a novel cell adhesion-promoting molecule, termed ARM-1 (adhesion regulating molecule-1), which is homologous to a human M r 110.000 tumor-associated antigen. The ARM-1 cDNA codes for a type I transmembrane protein of 407 amino acids with potential O- and N-glycosylation sites that does not belong to any of the known families of cell adhesion molecules. Overexpression of ARM-1 in 293T human embryonic kidney cells significantly increased adhesion to different endothelial cells. ARM-1 expression in 293T cells did not alter integrin expression or β1-integrin-mediated cell adhesion. Northern blot analysis of human breast cancer cell lines revealed 3- to 5-fold elevated ARM-1 mRNA levels in metastatic as compared to non-metastatic cells. In conclusion, we have identified ARM-1 as a novel cell adhesion-promoting receptor that is upregulated in metastatic cancer cells. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
Oxidized forms of fibrinogen similarly to initial non-oxidized fibrinogen induced expression of P-selectin and ICAM-1 cell adhesion molecules in the cultured endothelial cells derived from human umbilical vein. The effect of oxidized fibrinogen on the expression of adhesion molecules was more pronounced. These data attest to more active participation of oxidized forms of fibrinogen into inflammation in the vascular wall, the first stage of atherogenesis. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 142, No. 9, pp. 277–281, September, 2006  相似文献   

20.
目的探讨氟伐他汀对C反应蛋白(C-reactive protein,CRP)诱导的人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)细胞间黏附分子-1(intercellular adhesion molecule-1,ICAM-1)表达的影响。方法进行HUVECs原代培养,取第3~6代进行实验。分别以5、10、50和100mg/L浓度CRP作用HUVECs,分别作用6、12和24h,同时用氟伐他汀10-8、10-7、10-6和10-5mol/L浓度进行干预。用ELISA法测ICAM-1蛋白含量,RT-PCR测ICAM-1 mRNA表达。结果HUVECs对照组有少量ICAM-1蛋白和mRNA表达;CRP组ICAM-1蛋白和mRNA表达明显增强(P<0.01),且ICAM-1蛋白表达呈浓度和时间依赖性增加(P<0.01);氟伐他汀组ICAM-1蛋白及mRNA表达明显减弱(P<0.01),且氟伐他汀抑制CRP诱导的ICAM-1蛋白表达呈浓度依赖性(P<0.05)。结论氟伐他汀可能通过抑制CRP诱导ICAM-1产生,发挥抗动脉粥样硬化形成的作用。  相似文献   

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