Cariporide inhibits high glucose-mediated adhesion of monocyte-endothelial cell and expression of intercellular adhesion molecule-1

The aim of this study was to examine whether cariporide, a new inhibitor of Na(+)/H(+) exchanger 1 (NHE-1), may inhibit high glucose-induced monocyte-endothelial cell adhesion and the expression of intercellular adhesion molecule-1 (ICAM-1). Cultured endothelial cells were incubated with normal glucose control (5.5 mM), cariporide control (5.5 mM glucose plus 10 microM cariporide), hyperosmolarity (5.5 mM glucose plus 16.5 mM mannitol), high glucose (HG, 22 mM), low-concentration cariporide (22 mM glucose plus 0.1 microM cariporide), medium-concentration cariporide (22 mM glucose plus 1 muM cariporide), and high-concentration cariporide (22 mM glucose plus 10 microM cariporide) for 24 h. Monocytes were isolated from peripheral human blood. Adhered monocytes were quantified by measuring their protein content. ICAM-1 expression and NHE-1 activity was determined with enzyme-linked immunosorbent assay (ELISA) and pH-sensitive fluorescent spectrophotometry. Exposure of endothelial cells to HG for 24 h caused an increase of adhesion of monocytes to endothelial cells and an increased expression of ICAM-1. However, these effects were reversed by treatment with cariporide (0.1, 1, 10 microM) in a concentration-dependent manner. Furthermore, cariporide (1 microM) was able to inhibit the activation of NHE-1 induced by HG in endothelial cells. These findings suggest that cariporide might inhibit HG-mediated monocyte-endothelial cell adhesion and expression of ICAM-1 by inhibiting the activation of NHE-1.     

The influence of garlic (Allium sativum) extract on interleukin 1alpha-induced expression of endothelial intercellular adhesion molecule-1 and vascular cell adhesion molecule-1.

Inflammation plays an important role in both the initiation of atherosclerosis and development of atherothrombotic events. The adherence of leukocytes/monocytes to the endothelium is an early event in atherogenesis. Phytotherapeutica as garlic and garlic extracts were shown to have beneficial modulating effects in patients with atherosclerotic disease. The aim of this study was to evaluate in vitro the influence of water-soluble garlic (Allium sativum) extract on the cytokine-induced expression of endothelial leukocyte adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1, CD54) and vascular cell adhesion molecule-1 (VCAM-1, CD106). Cytokine-induced expression of cellular adhesion molecules was measured on primary human coronary artery endothelial cell (HCAEC) cultures. HCAEC were cultured in microvascular endothelial cell growth medium and preincubated with garlic extract at various concentrations (0.25-4.0 mg/ml), after which human interleukin-1alpha (IL-1alpha, 10 ng/ml) was added for 1 day. Fluorescein isothiocyanate (FITC)-labeled anti-ICAM-1 and FITC-labeled anti-VCAM-1 were used to analyze the IL-1alpha-induced expression of ICAM-1 and VCAM-1 by flow cytometry. Incubation of HCAEC with garlic extract significantly decreased ICAM-1 and VCAM-1 expression induced by IL-1alpha. In addition, we examined the effects of garlic extract on the adhesion of monocytes to endothelial cells, using the monocytic U937 cell line. The presence of garlic extract significantly inhibited the adhesion of monocytes to IL-1alpha-stimulated endothelial cells. These results indicate that garlic extract modulates the expression of ICAM-1 and VCAM-1, thus potentially contributing to the beneficial effects traditionally attributed to garlic.     

Role for neutral sphingomyelinase-2 in tumor necrosis factor alpha-stimulated expression of vascular cell adhesion molecule-1 (VCAM) and intercellular adhesion molecule-1 (ICAM) in lung epithelial cells: p38 MAPK is an upstream regulator of nSMase2

Neutral sphingomyelinases (N-SMases) are major candidates for stress-induced ceramide production. However, there is little information on the physiological regulation and roles of the cloned N-SMase enzyme, nSMase2. In this study, nSMase2 was found to translocate acutely to the plasma membrane of A549 epithelial cells in response to tumor necrosis factor alpha (TNF-alpha) in a time- and dose-dependent manner. Additionally, TNF-alpha increased N-SMase activity rapidly and transiently both endogenously and in cells overexpressing nSMase2. Furthermore, the translocation of nSMase2 was regulated by p38-alpha MAPK, but not ERK or JNK, and the increase in endogenous N-SMase activity was abrogated by p38 MAPK inhibition. In addition, both p38-alpha MAPK and nSMase2 were implicated in the TNF-alpha-stimulated up-regulation of the adhesion proteins vascular cell adhesion molecule-1 (VCAM) and intercellular adhesion molecule-1 (ICAM), but this was largely independent of NF-kappaB activation. These data reveal p38 MAPK as an upstream regulator of nSMase2 and indicate a role for nSMase2 in pro-inflammatory responses induced by TNF-alpha as a regulator of adhesion proteins.     

Prognostic value of infiltrating immune cells in clear cell renal cell carcinoma (ccRCC)

In this study, we attempted to evaluate the prognostic value of infiltrating immune/stromal cells in clear cell renal cell carcinoma (ccRCC), by using the immune scores and stromal scores based on the “Estimation of STromal and Immune cells in MAlignant Tumours using Expression data” algorithm to represent the levels of infiltrating immune cells and stromal cells. We found that the infiltrating immune cells were associated with poor prognosis of ccRCC. To assess the role of infiltrating immune cells in ccRCC cells, first, we performed differentially expressed genes analysis and functional analysis for validation. The results showed that the underlying mechanism by which infiltrating immune cells promoted cancer progression involved in regulating the nuclear division, angiogenesis, and immune response. Next, we investigated the relationship between infiltrating immune cells and mutations in ccRCC cells. We found that the infiltrating immune cells have certain effects on genetic mutations. In conclusion, infiltrating immune cells within the tumor microenvironment can be used to predict prognosis in ccRCC.     

Soluble intercellular adhesion molecule-1 (sICAM-1): an overview

Soluble intercellular adhesion molecule-1 (sICAM-1) represents a circulating form of ICAM-1 that is constitutively expressed or is inducible on the cell surface of different cell lines. It serves as a counter-receptor for the lymphocyte function-associated antigen (LFA-1). Interaction between ICAM-1, present on endothelial cells, and LFA-1 facilitates leukocyte adhesion and migration across the endothelium. ICAM-1 and its circulating form have been implicated in the development of any number of diseases.     

Flow cytometric determination of E-selectin, vascular cell adhesion molecule-1, and intercellular cell adhesion molecule-1 in formaldehyde-fixed endothelial cell monolayers

BACKGROUND: Endothelial cell adhesion molecules are involved in initiation and progression of vascular diseases. The purpose of this study was to determine conditions of fixation and dissociation of human umbilical vein endothelial cell (HUVEC) monolayers that permit a reliable flow cytometric determination of intracellular and surface content of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). METHODS: TNFalpha-treated HUVEC monolayers were fixed with 0.5% formaldehyde at the end of the experimental incubation. Subsequently, either the monolayer was trypsinized and thereafter the cells were subjected to indirect fluorescence labeling or the monolayer was first labeled and then dissociated by trypsinization. Cell integrity was assessed by vimentin staining. Total adhesion molecule content was detected in saponin-permeabilized cells. RESULTS: HUVEC integrity was maintained when the fixation time of the monolayer did not exceed 5 min and trypsin/EDTA was used for dissociation. Surface adhesion molecules were partially hydrolyzed by trypsin when trypsinization preceded labeling but antibody binding protected adhesion molecules from degradation. VCAM-1 and E-selectin exhibited substantial trypsin-sensitive surface fractions but surface ICAM-1 was mainly trypsin resistant. Permeabilization with 0.06% saponin allowed the detection of considerable intracellular pools of the investigated adhesion molecules. CONCLUSIONS: The described method permits the reliable determination of surface and intracellular fractions of adhesion molecules in formaldehyde-fixed HUVEC monolayers and may be used for studies on the regulation of adhesion molecule expression.     

Interleukin-11 increases cell motility and up-regulates intercellular adhesion molecule-1 expression in human chondrosarcoma cells

Interleukin‐11 (IL‐11) was originally identified as the cytokine that could induce the proliferation of human cells. Recent studies have shown that IL‐11 plays a critical role in tumor growth, angiogenesis, and metastasis. Chondrosarcoma is a type of highly malignant tumor with a potent capacity to invade locally and cause distant metastasis. However, the effects of IL‐11 on human chondrosarcoma cells are largely unknown. Here, we found that IL‐11 increased the migration and expression of intercellular adhesion molecule‐1 (ICAM)‐1 in human chondrosarcoma cells. We also found that human chondrosarcoma tissues had significant expression of the IL‐11 which was higher than that in primary chondrocytes. The phosphatidylinositol 3‐kinase (PI3K), Akt, and NF‐κB pathways were activated by IL‐11 treatment, and the IL‐11‐induced expression of ICAM‐1 and migration activity were inhibited by the specific inhibitors and mutant forms of PI3K, Akt, and NF‐κB cascades. Taken together, our results indicate that IL‐11 enhanced the migration of the chondrosarcoma cells by increasing ICAM‐1 expression through the IL‐11Rα receptor, PI3K, Akt, and NF‐κB signal transduction pathway. J. Cell. Biochem. 113: 3353–3362, 2012. © 2012 Wiley Periodicals, Inc.     

The blood concentration of intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) in patients with active thyroid-associated orbitopathy before and after methylprednisolone treatment

BACKGROUND: The soluble forms of vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) have been found to be increased in the blood of patients with Graves disease. The aim of this study is evaluation of the serum concentrations of soluble forms of adhesion molecules ICAM-1 and VCAM-1 in patients with thyroid-associated orbitopathy (TAO) before and after methylprednisolone treatment. MATERIAL AND METHODS: The study was performed in 40 Graves disease, hyperthyroid and euthyroid patients with a clinically active form of TAO. Serum concentrations of sVCAM-1 and sICAM-1 in TAO patients were determined by enzymelinked immunoabsorbent assay (ELISA) before and after intensive pulse methylprednisolone treatment. RESULTS: We did not find any significant changes in the studied parameters between TAO patients with hyperthyroidism and those with euthyroidism. The serum concentrations of sICAM-1 and sVCAM-1 were significantly increased in patients with TAO before methylprednisolone therapy when compared with the control group. After treatment serum concentrations of sICAM-1 and sVCAM-1 decreased significantly but were still significantly higher than for the control group. CONCLUSION: From the results obtained we can conclude that Graves orbitopathy itself but not thyroid function is probably responsible for the elevated level of the adhesion molecules studied.     

The role of CEA-related cell adhesion molecule-1 (CEACAM1) in vascular homeostasis

Carcinoembryonic antigen (CEA)-related cell adhesion molecules belong to the immunoglobulin superfamily, are expressed in a broad spectrum of tissues and cell types and exert context-dependent activating as well as inhibitory effects. Among these molecules, the CEA-related cell adhesion molecule-1 (CEACAM1) is a transmembrane molecule with an extracellular, a transmembrane and a cytoplasmic domain. The latter contains immunoreceptor tyrosine-based inhibitory motifs and functions as a signaling molecule. CEACAM1 can form homo- and heterodimers which is relevant for its signaling activities. CEACAM1 acts as co-receptor that modulates the activity of different receptor types including VEGFR-2, and B and T cell receptors. CEACAM1 is expressed in endothelial cells, in pericytes of developing and newly formed immature blood vessels and in angiogenically activated adult vessels, e.g., tumor blood vessels. However, it is either undetectable or only weakly expressed in quiescent blood vessels. Recent studies indicated that CEACAM1 is involved in the regulation of the endothelial barrier function. In CEACAM1 ^?/? mice, increased vascular permeability and development of small atherosclerotic lesions was observed in the aortae. CEACAM1 is also detectable in activated lymphatic endothelial cells and plays a role in tumor lymphangiogenesis. This review summarizes the vascular effects of CEACAM1 and focuses on its role in vascular morphogenesis and endothelial barrier regulation.     

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.     

Differential role of distinct determinants of intercellular adhesion molecule-1 in immunologic phenomena

This study analyzed 1) the relationship between the molecules recognized by anti-intercellular adhesion molecule-1 (ICAM-1) mAb RR 1/1 and by anti-96K melanoma-associated Ag mAb CL203.4 in lymphoid cells, 2) the induction of ICAM-1 on activated PBMC, and 3) the functional activity of distinct and spatially distant determinants recognized by mAb CL203.4 and RR1/1. Sequential immunoprecipitation experiments showed that the determinant recognized by mAb CL203.4 is expressed on a slightly broader population of ICAM-1 molecules than that defined by mAb RR1/1. Serologic and immunochemical assays have shown that ICAM-1 is induced on lymphocytes activated with Con A, PHA-M, IL-2, allogeneic HLA mismatched lymphocytes and autologous PHA-M-activated T cells. However, ICAM-1 was not detected on lymphocytes incubated with IFN-gamma. Incubation of monocytes with LPS induced ICAM-1 in the subpopulation which lacks it and increased its density on the cells which express it. Induction of ICAM-1 is an early event in the activation process and precedes the appearance of IL-2 and transferrin receptors. Comparison of the functional activity of the anti-ICAM-1 mAb CL203.4 and RR1/1 showed that both of them inhibit to a similar extent proliferation of lymphocytes stimulated with PHA-M and with allogeneic lymphocytes, but that only mAb RR1/1 inhibits PMA-induced aggregation of cultured B lymphoid cells JY, of promonocytic cells U-937 and of PHA-blasts as well as LAK cell-mediated cytotoxicity of target cells. mAb CL203.4 represents the first example of anti-ICAM-1 mAb without inhibitory effect on the aggregation of lymphoid cells. The differential functional activity of mAb CL203.4 and RR1/1 does not reflect differences in their affinity, because they display a similar affinity constant to lymphoid cells. These results suggest that distinct determinants of ICAM-1 play a different role in immunologic phenomena.     

Ultrastructure and function of dimeric, soluble intercellular adhesion molecule-1 (ICAM-1)

Previous studies have demonstrated dimerization of intercellular adhesion molecule-1 (ICAM-1) on the cell surface and suggested a role for immunoglobulin superfamily domain 5 and/or the transmembrane domain in mediating such dimerization. Crystallization studies suggest that domain 1 may also mediate dimerization. ICAM-1 binds through domain 1 to the I domain of the integrin alpha(L)beta(2) (lymphocyte function-associated antigen 1). Soluble C-terminally dimerized ICAM-1 was made by replacing the transmembrane and cytoplasmic domains with an alpha-helical coiled coil. Electron microscopy revealed C-terminal dimers that were straight, slightly bent, and sometimes U-shaped. A small number of apparently closed ring-like dimers and W-shaped tetramers were found. To capture ICAM-1 dimerized at the crystallographically defined dimer interface in domain 1, cysteines were introduced into this interface. Several of these mutations resulted in the formation of soluble disulfide-bonded ICAM-1 dimers (domain 1 dimers). Combining a domain 1 cysteine mutation with the C-terminal dimers (domain 1/C-terminal dimers) resulted in significant amounts of both closed ring-like dimers and W-shaped tetramers. Surface plasmon resonance studies showed that all of the dimeric forms of ICAM-1 (domain 1, C-terminal, and domain 1/C-terminal dimers) bound similarly to the integrin alpha(L)beta(2) I domain, with affinities approximately 1.5--3-fold greater than that of monomeric ICAM-1. These studies demonstrate that ICAM-1 can form at least three different topologies and that dimerization at domain 1 does not interfere with binding in domain 1 to alpha(L)beta(2).     

Prognostic value of a gene signature in clear cell renal cell carcinoma

Renal cancer is a common urogenital system malignance. Novel biomarkers could provide more and more critical information on tumor features and patients’ prognosis. Here, we performed an integrated analysis on the discovery set and established a three-gene signature to predict the prognosis for clear cell renal cell carcinoma (ccRCC). By constructing a LASSO Cox regression model, a 3-messenger RNA (3-mRNA) signature was identified. Based on the 3-mRNA signature, we divided patients into high- and low-risk groups, and validated this by using three other data sets. In the discovery set, this signature could successfully distinguish between the high- and low-risk patients (hazard ratio (HR), 2.152; 95% confidence interval (CI),1.509–3.069; p < 0.0001). Analysis of internal and two external validation sets yielded consistent results (internal: HR, 2.824; 95% CI, 1.601–4.98; p < 0.001; GSE29609: HR, 3.002; 95% CI, 1.113–8.094; p = 0.031; E-MTAB-3267: HR, 2.357; 95% CI, 1.243–4.468; p = 0.006). Time-dependent receiver operating characteristic (ROC) analysis indicated that the area under the ROC curve at 5 years was 0.66 both in the discovery and internal validation set, while the two external validation sets also suggested good performance of the 3-mRNA signature. Besides that, a nomogram was built and the calibration plots and decision curve analysis indicated the good performance and clinical utility of the nomogram. In conclusion, this 3-mRNA classifier proved to be a useful tool for prognostic evaluation and could facilitate personalized management of ccRCC patients.     

Human cytomegalovirus-induced upregulation of intercellular cell adhesion molecule-1 on villous syncytiotrophoblasts

Human cytomegalovirus (HCMV) is secreted apically from villous trophoblasts, thus congenital infection is not likely to occur by basal release across the basement membrane. As an alternative route, we hypothesize that an HCMV-infected villous syncytiotrophoblast (ST) upregulates intercellular adhesion molecule (ICAM)-1, causing blood monocytes to bind to the ST and induce apoptosis. Purified (>99.99%) populations of human villous trophoblasts were differentiated into an ST-like culture, infected with HCMV strain AD169, and assessed for ICAM-1 expression by immunofluorescence. Infection strongly upregulated ICAM-1 24 h after challenge. ICAM-1 was also stimulated by transfection with viral genes IE2-55, IE1-72, and IE2-86, but not by UV-inactivated virus. Infection with a green fluorescent protein recombinant virus allowed infection and ICAM-1 expression to be topographically located. We found that ICAM-1 was expressed on both infected and noninfected cells. Furthermore, antibody to tumor necrosis factor (TNF)alpha and, to a lesser extent, interleukin (IL)1 beta inhibited ICAM-1 upregulation on noninfected cells but not on infected cells. We conclude that HCMV IE proteins stimulate ICAM-1 expression on villous trophoblasts by paracrine release of TNF alpha and IL1 beta, as well as by a direct effect on infected cells.     

Nerve/glial antigen (NG) 2 is a crucial regulator of intercellular adhesion molecule (ICAM)-1 expression

The proteoglycan nerve/glial antigen (NG) 2 is expressed on multiple cell types and mediates cell proliferation and migration. However, little is known about its function in gene regulation. In this study, we demonstrate that in pericytes and glioblastoma cells intercellular adhesion molecule (ICAM)-1, an essential protein for leukocyte adhesion and transmigration, underlies a NG2-dependent expression. As shown by flow cytometry, Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR), silencing of NG2 in human placenta-derived pericytes increased the expression of ICAM-1. Pathway analyses revealed that this is mediated by extracellular-regulated-kinases (ERK) 1/2 signaling. Moreover, leukocyte adhesion to NG2 siRNA-treated pericytes was significantly enhanced when compared to scrambled (scr) siRNA-treated control cells. In vivo, we detected increased ICAM-1 protein levels in the retina of mice lacking NG2 expression. To exclude that this novel mechanism is pericyte-specific, we additionally analyzed the expression of ICAM-1 in dependency of NG2 in two glioblastoma cell lines. We found that A1207 and M059K cells exhibit an inverse expression pattern of NG2 and ICAM-1. Finally, downregulation of NG2 in A1207 cells significantly increased ICAM-1 expression. Taken together, these findings indicate that NG2 may represent a promising target for the modulation of ICAM-1-mediated immune responses.     

Signals mediating cleavage of intercellular adhesion molecule-1

ICAM-1, a membrane-bound receptor, is released as soluble ICAM-1 in inflammatory diseases. To delineate mechanisms regulating ICAM-1 cleavage, studies were performed in endothelial cells (EC), human embryonic kidney (HEK)-293 cells transfected with wild-type (WT) ICAM-1, and ICAM-1 containing single tyrosine-to-alanine substitutions (Y474A, Y476A, and Y485A) in the cytoplasmic region. Tyrosine residues at 474 and 485 become phosphorylated upon ICAM-1 ligation and associate with signaling modules. Cleavage was assessed by using an antibody against the cytoplasmic tail of ICAM-1, which recognizes intact ICAM-1 and the 7-kDa membrane-bound fragment remaining after cleavage. Cleavage in HEK-293 WT cells was accelerated by phorbol ester PMA, whereas in EC it was induced by tumor necrosis factor-. In both cell types, a 7-kDa ICAM-1 remnant was detected. Tyrosine phosphatase inhibitors dephostatin and sodium orthovanadate augmented cleavage. PD-98059 (MEK kinase inhibitor), geldanamycin and PP2 (Src kinase inhibitors), and wortmannin (phosphatidylinositol 3-kinase inhibitor) dose-dependently inhibited cleavage in both cell types. SB-203580 (p38 inhibitor) was more effective in EC, and D609 (PLC inhibitor) mostly affected cleavage in HEK-293 cells. Cleavage was drastically decreased in Y474A and Y485A, whereas it was marginally reduced in Y476A. Surprisingly, phosphorylation was not detectable on the 7-kDa fragment of ICAM-1. These results implicate distinct pathways in the cleavage process and suggest a preferred signal transmission route for ICAM-1 shedding in the two cell systems tested. Tyrosine residues Y474 and Y485 within the cytoplasmic sequence of ICAM-1 regulate the cleavage process. ectodomain shedding; signaling; tyrosine phosphorylation