Cytokine-induced Intercellular Adhesion Molecule-1 Expression Research Articles

Butyrate Decreases ICAM-1 Expression in Human Oral Squamous Cell Carcinoma Cells.

Short-chain fatty acids (SCFA) are bacterial metabolites that can be found in periodontal pockets. The expression of adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) within the epithelium pocket is considered to be a key event for the selective transmigration of leucocytes towards the gingival sulcus. However, the impact of SCFA on ICAM-1 expression by oral epithelial cells remains unclear. We therefore exposed the oral squamous carcinoma cell line HSC-2, primary oral epithelial cells and human gingival fibroblasts to SCFA, namely acetate, propionate and butyrate, and stimulated with known inducers of ICAM-1 such as interleukin-1-beta (IL1β) and tumor necrosis factor-alfa (TNFα). We report here that butyrate but not acetate or propionate significantly suppressed the cytokine-induced ICAM-1 expression in HSC-2 epithelial cells and primary epithelial cells. The G-protein coupled receptor-43 (GPR43/ FFAR2) agonist but not the histone deacetylase inhibitor, trichostatin A, mimicked the butyrate effects. Butyrate also attenuated the nuclear translocation of p65 into the nucleus on HSC-2 cells. The decrease of ICAM-1 was independent of Nrf2/HO-1 signaling and phosphorylation of JNK and p38. Nevertheless, butyrate could not reverse an ongoing cytokine-induced ICAM-1 expression in HSC-2 cells. Overall, these observations suggest that butyrate can attenuate cytokine-induced ICAM-1 expression in cells with epithelial origin.

Quercetin and EGCG Exhibit Chemopreventive Effects in Cholangiocarcinoma Cells via Suppression of JAK/STAT Signaling Pathway

Quercetin and epigallocatechin-3-gallate (EGCG) are dietary phytochemicals with antiinflammatory and antitumor effects. In the present study, we examined the effects of these two compounds on Janus-like kinase (JAK)/signal transduction and transcription (STAT) pathway of cholangiocarcinoma (CCA) cells, because CCA is one of the aggressive cancers with very poor prognosis and JAK/STAT pathway is critically important in inflammation and carcinogenesis. The results showed that the JAK/STAT pathway activation by proinflammatory cytokine interleukin-6 and interferon-γ in CCA cells was suppressed by pretreatment with quercetin and EGCG, evidently by a decrease of the elevated phosphorylated-STAT1 and STAT3 proteins in a dose-dependent manner. The cytokine-mediated up-regulation of inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) via JAK/STAT cascade was abolished by both quercetin and EGCG pretreatment. Moreover, these flavonoids also could inhibit growth and cytokine-induced migration of CCA cells. Pretreatment with specific JAK inhibitors, AG490 and piceatannol, abolished cytokine-induced iNOS and ICAM-1 expression. These results demonstrate beneficial effects of quercetin and EGCG in the suppression of JAK/STAT cascade of CCA cells. Quercetin and EGCG would be potentially useful as cancer chemopreventive agents against CCA.

Effects of technetium-99 methylenediphosphonate on cytokine-induced activation of retro-ocular fibroblasts from patients with Graves' ophthalmopathy

To explore the effects of technetium-99 methylenediphosphonate (99Tc-MDP) on cell proliferation, hyaluronic acid (HA) synthesis and the expressions of human leucocyte antigen-DR (HLA-DR), intercellular adhesion molecule-1 (ICAM-1) on cultured retro-ocular fibroblasts (RFs) from patients with Graves' ophthalmopathy. After two to seven passages, cultured RFs were incubated for 72 h with interferon-γ (100 U/ml), interleukin-1 (100 U/ml) or tumour necrosis factor-α (100 U/ml) in the presence of 99Tc-MDP. Flow cytometry was used to investigate the expression of HLA-DR and ICAM-1. RF proliferation was assessed by 3H-thymidine incorporation assay. HA synthesis was measured by radioimmunoassay. At base conditions, the percentage of positive cells of HLA-DR and ICAM-1 on RFs was 6.70±3.06% and 5.29±3.02%, respectively, and the synthesis of HA was 337.8±42.7 ng/ml. Compared with basal values, 72-h incubation with cytokine significantly enhanced the expression of HLA-DR and ICAM-1, and HA synthesis. 99Tc-MDP (1 ng/ml) had little effect on cytokine-induced HLA-DR and ICAM-1 expression, and HA synthesis. When the concentration ranged from 10 to 100 ng/ml, 99Tc-MDP inhibited cytokine-induced RF activation in a dose-dependent manner. 99Tc-MDP also inhibited the proliferation of RFs in a dose-dependent manner. It was also found that 99Tc-MDP had the same effect on cytokine-induced RFs and skin fibroblasts from patients with normal individual conditions. 99Tc-MDP could inhibit cytokine-induced activation of RFs derived from patients with Graves' ophthalmopathy.

Inhibition of TNF-α induced ICAM-1, VCAM-1 and E-selectin expression by selenium

The initiation of an atherosclerotic lesion involves an endothelial cell pro-inflammatory state that recruits leukocytes and promotes their movement across the endothelium. These processes require endothelial expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial-leukocyte adhesion molecule-1 (E-selectin). Tumor necrosis factor-α (TNF-α) is a powerful inducer of these adhesion molecules. Selenium status is known to affect the rate of atherosclerosis. These experiments tested whether selenium alters cytokine-induced expression of these adhesion molecules. Human umbilical vein endothelial cells (HUVECs) were pretreated for 24 h with sodium selenite (0–2 μM) and then treated with 0 or 50 U/ml TNF-α in the presence of 0–2 μM selenite. ICAM-1, VCAM-1 and E-selectin were detected by ELISA and their mRNAs were evaluated by Northern blots. Selenite significantly inhibited TNF-α-induced expression of each adhesion molecule in a dose-dependent manner and reduced the level of the respective mRNAs. Nuclear factor-κB (NF-κB) is required for transcription of these adhesion molecule genes. Western blot analysis revealed that selenite did not inhibit the translocation of the p65 subunit of NF-κB to the nucleus. In conclusion, these data indicate selenium can modulate cytokine-induced expression of ICAM-1, VCAM-1 and E-selectin in HUVECs without interfering with translocation of NF-κB.

Activation of p55 tumor necrosis factor-alpha receptor-1 coupled to tumor necrosis factor receptor-associated factor 2 stimulates intercellular adhesion molecule-1 expression by modulating a thapsigargin-sensitive pathway in human tracheal smooth muscle cells.

Tumor necrosis factor-alpha (TNFalpha) stimulates the expression of intercellular adhesion molecule-1 (ICAM-1) by activating the transcription factor nuclear factor-kappaB (NF-kappaB) in human airway smooth muscle (ASM) cells. This study characterizes the receptor involved as well as critical downstream signaling events mediating cytokine-induced NF-kappaB activation and ICAM-1 expression. TNFalpha stimulation for 1 to 4 h induced ICAM-1 expression in human ASM cells. This rapid TNFalpha-induced ICAM-1 expression enhanced T-lymphocyte adhesion to ASM cells, which was inhibited by anti-ICAM-1 antibodies. Using immunostaining, we demonstrated that TNFalpha receptors TNFR1 and TNFR2 are expressed on native human tracheal smooth muscle. Treatment of cells with htr-9, an antibody that specifically activates TNFR1, also stimulated expression of ICAM-1 mRNA and protein. Utr-1, a blocking antibody to TNFR2, did not affect TNFalpha-mediated ICAM-1 expression. Both TNFalpha and htr-9 increased luciferase activity in ASM cells transfected with a NF-kappaB reporter plasmid. Overexpression of a dominant negative TNF receptor-associated factor 2 construct, lacking the NH(2)-terminal RING finger, completely abrogated both TNFalpha- and htr-9-mediated increases in NF-kappaB reporter activity. Thapsigargin, an agent that depletes intracellular calcium stores, abrogated both cytokine-mediated NF-kappaB-dependent ICAM-1 mRNA transcription and protein expression but had no effect on IkappaB degradation. In addition, chelating cytosolic calcium with 1,2-bis(2-aminophenoxy)ethane-N,N,N', N'-tetraacetic acid acetoxymethyl ester also inhibited cytokine TNFalpha-induced ICAM-1 expression. These data suggest that TNFR1, through a TNF receptor-associated factor 2-NF-kappaB signaling pathway, mediates TNFalpha-induced expression of ICAM-1 on ASM cells by involving a thapsigargin-sensitive signaling pathway.

Cytokine-induced VCAM-1 and ICAM-1 expression in different organs of the mouse.

The dual radiolabeled mAb technique was used to quantify the constitutive and induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the microvasculature of different organs of the mouse. The constitutive expression of both adhesion molecules varied significantly between tissues, with ICAM-1 levels consistently higher than VCAM-1 in all tissues studied. Following systemic administration of endotoxin (LPS), an increased surface expression of both adhesion molecules occurred in most organs, with the largest increases for ICAM-1 (2 to 3x increase) noted in the heart, small intestine, and brain, while heart and small intestine exhibited the largest increases in LPS-induced VCAM-1 expression (2 to 5x increase). These responses occurred in the face of an unaltered expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) in all tissues. TNF-alpha also elicited an increased expression of both adhesion molecules, with initial increases noted at 2 to 5 h, peak levels at 5 to 9 h, and a sustained elevation above baseline at 24 h. The TNF-alpha-induced increases in both ICAM-1 and VCAM-1 were dose dependent, with significant up-regulation noted at 5 microg/kg and maximal increases occurring at 10 to 25 microg/kg. These studies indicate that while there are significant quantitative differences in constitutive and induced expression of murine ICAM-1 and VCAM-1, the kinetics and dose-response characteristics of the two adhesion molecules to TNF-alpha are qualitatively similar.

Effects of Tumor Necrosis Factor and Pentoxifylline on ICAM-1 Expression on Human Polymorphonuclear Granulocytes

Intercellular adhesion molecule-1 (ICAM-1) is a cytokine-inducible adhesion molecule, expressed on cells of multiple lineages at the site of inflammation. Cytofluorometric analysis revealed that CD16-positive peripheral blood polymorphonuclear leukocytes (PMNs, neutrophils) expressed ICAM-1 on their surface, and it was upregulated by in vitro stimulation with tumor necrosis factor (TNF), GM-CSF and Staphylococcus aureus. The S. aureus-induced stimulation of ICAM-1 expression was inhibited by pentoxifylline (PTX). As TNF is a potent inducer of ICAM-1 expression, it is concluded that in these experiments the inhibition of TNF production by PTX concomitantly resulted in the inhibition of the upregulation of ICAM-1. However, the inhibition of granulocyte apoptosis by PTX might be of importance in this process. The present study provides evidence that cytokine-stimulated neutrophils are able to express the adhesion molecule ICAM-1 and this may allow ICAM-1-positive neutrophils to physically interact with LFA-1-positive inflammatory cells. The preliminary results demonstrate that the basal expression of ICAM-1 on PMNs of septic patients is higher than that in the case of normal blood donors. Further studies will elucidate the in vivo relevance of cytokine-induced neutrophil ICAM-1 expression and the potential role of its inhibition by PTX in inflammatory response disorders.

Cytokine-Induced ICAM-1 Expression in Human Keratinocytes Is Highly Variable in Keratinocyte Strains from Different Donors

Induction of intercellular adhesion molecule 1 (ICAM-1) expression in the epidermis is felt to be an important initiator of leukocyte/keratinocyte interactions in many inflammatory skin diseases. The purpose of this project was to determine the individual variability of cytokine-induced ICAM-1 expression in human keratinocytes obtained from different donors. In 55 different keratinocyte strains, there was significant individual variability in ICAM-1 expression by either tumor necrosis factor alpha (TNF-alpha) or interferon-gamma. There was no correlation (r = 0.266, p = 0.06) in response of the same strain to either TNF-alpha or interferon-gamma. Multiple (n = 22) keratinocyte strains showed no significant induction of ICAM-1 expression to IL-1. The level of ICAM-1 expression in response to TNF-alpha and ultraviolet radiation (UVR) in individual strains was highly correlated in three different comparisons: level of stimulated response versus baseline (TNF-alpha and UVR both p < 0.0001); stimulation index TNF-alpha versus UVR (p = 0.00947); and variability of stimulated response versus variability of baseline (TNF p < 0.001; UVR p = 0.002). UVR-induced release of TNF from keratinocytes also showed variability among different keratinocyte strains. The UVR-induced ICAM-1 response in human keratinocytes and transformed epithelial cell was variably blocked with anti-TNF antibodies. The release of TNF from keratinocytes by UVR and the individually variable but linked characteristics of UVR and TNF-alpha stimulated ICAM-1 expression support the hypothesis that TNF-alpha is a major mediator of UVR-induced ICAM-1 expression.

Corticosteroids induce proliferation but do not influence TNF- or IL-1 beta-induced ICAM-1 expression of human dermal microvascular endothelial cells in vitro.

The effects of hydrocortisone, dexamethasone, betamethasone 17-valerate and clobetasol propionate at concentrations of 10(-5)-10(-12) M on the proliferation of human dermal microvascular endothelial cells (HDMEC) were studied in vitro. In addition, confluent HDMEC were treated with TNF (1000 U/ml) or IL-1 beta (1000 U/ml) alone or in combination with the corticosteroids (10(-5) M, 10(-6) M) for 24 h, and cytokine-induced expression of intercellular adhesion molecule-1 (ICAM-1) was assessed by immunocytochemistry. Controls were treated either with growth medium or with the corticosteroids alone. All tested corticosteroids stimulated HDMEC growth after 4 and 6 days of treatment in a dose-dependent manner, as assessed by 3H-thymidine incorporation and the 4-methyl-umbelliferyl heptanoate (MUH) assay. The minimal effective concentration was 10(-9) M for hydrocortisone, 10(-10) M for dexamethasone and betamethasone, and 10(-12) M for clobetasol. In untreated and in corticosteroid-treated cultures, less than 5% of the cells expressed ICAM-1. TNF and IL-1 beta were strong inducers of ICAM-1 expression on 74% and 82% of the cells, respectively. None of the tested corticosteroids significantly influenced cytokine-induced ICAM-1 expression, suggesting that the anti-inflammatory effects of corticosteroids are not related to ICAM-1 modulation on HDMEC.

Induction of Intercellular Adhesion Molecule 1 (ICAM-1) Expression in Normal Human Eosinophils by Inflammatory Cytokines

Intercellular adhesion molecule-1 (ICAM-1) functions as a ligand for lymphocyte function-associated antigen-1 (LFA-1), and thereby plays a crucial role in mediating cell-cell interactions in inflammatory reactions. Human eosinophils represent important effector cells in allergic skin diseases. To gain more insight into the capacity of eosinophils to physically interact with LFA-1-positive inflammatory leukocytes, in the present study ICAM-1 expression in eosinophils was investigated. Using fluorescence-activated cell sorter analysis, it could be shown that highly purified (> or = 95%) eosinophils from peripheral blood of non-atopic individuals do not constitutively express ICAM-1 molecules. However, stimulation of eosinophils with interferon gamma (IFN gamma), tumor-necrosis factor alpha (TNF alpha), or interleukin 3 (IL-3) markedly upregulated ICAM-1 surface expression in a time- and dose-dependent manner. Cytokine-induced ICAM-1 expression in human eosinophils was corroborated by Northern blot analysis. Accordingly, unstimulated eosinophils did not express significant amounts of ICAM-1 mRNA, but ICAM-1 mRNA expression could be markedly induced in these cells upon stimulation with IFN gamma plus TNF alpha. The combination of TNF alpha with either IFN gamma, IL-3, IL-5, or granulocyte/macrophage colony-stimulating factor (GM-CSF) increased ICAM-1 expression in a synergistic fashion, whereas IL-5 or GM-CSF by itself did not induce ICAM-1 expression. Cytokine-induced ICAM-1 expression was specific, because IL-1 alpha, IL-1 beta, IL-2, IL-4, IL-6, IL-7, IL-8, C5a, and platelet-activating factor did not significantly affect eosinophil ICAM-1 surface expression. In summary, these studies indicate that eosinophils may be activated to express the adhesion molecule ICAM-1 upon stimulation with selected inflammatory cytokines, which may allow adhesion-mediated cross-talk between eosinophils and LFA-1-positive cells. In addition, these data demonstrate for the first time a role for IL-3, IL-5, and GM-CSF in regulation of ICAM-1 expression in human cells.

Induction of ICAM-1 by TNF-alpha, IL-1 beta, and LPS in human endothelial cells after downregulation of PKC.

The intercellular adhesion molecule 1 (ICAM-1) is induced on endothelial cells by tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and lipopolysaccharide (LPS). We have reported the sensitivity of cytokine-induced ICAM-1 expression to protein kinase inhibitors, including inhibitors of protein kinase C (PKC) [C. L. Myers, S. N. Desai, J. Schembri-King, G. L. Letts, and R. W. Wallace. Am. J. Physiol. 262 (Cell Physiol. 31): C365-C373, 1992]. To directly investigate the role of PKC in ICAM-1 induction, we downregulated PKC by pretreatment of human umbilical vein endothelial cells with phorbol 12-myristate 13-acetate (PMA) and assessed ICAM-1 protein and mRNA induction elicited by subsequent exposure to inflammatory stimuli. PMA treatment results in ICAM-1 protein induction that declines to basal levels by 3 days. Western blots of endothelial cell lysates reveal a nearly complete loss of immunologically reactive PKC. Subsequent activation with cytokine or LPS leads to reinduction of ICAM-1 protein and mRNA; however, the cells no longer produced substantial amounts of ICAM-1 protein or mRNA in response to PMA stimulation. Cross desensitization is observed with phorbol dibutyrate, while 4 alpha-phorbol has no desensitizing effect. The data indicate that PKC activation, while capable of inducing ICAM-1 expression, is not essential for ICAM-1 induction by the inflammatory mediators TNF-alpha, IL-1 beta, or LPS.

Modulation of intercellular Adhesion Molecule-1 Expression on Human Melanocytes and Melanoma Cells: Evidence for a Regulatory Role of IL-6, IL-7, TNFβ, and UVB Light

Intercellular adhesion molecule-1 (ICAM-1) is involved in cell-cell interactions of leukocytes and parenchymal cells and thus plays an important role in immunologic and inflammatory reactions. The expression of ICAM-1 that is found on many different cells such as melanocytes and melanoma cells is induced by various cytokines, including interferon-gamma (IFN gamma), interleukin (IL)-1 and tumor necrosis factor alpha (TNF alpha). Because expression of ICAM-1 in melanoma was found to correlate with increased risk of metastasis, the regulation of ICAM-1 expression on human melanocytes and melanoma cells was investigated. Foreskin-derived melanocytes and melanoma cell lines (A375, G361) were incubated with different cytokines and ICAM-1 expression was evaluated by fluorescence-activated cell sorter. IFN gamma, IL-1, IL-7, TNF alpha, and TNF beta significantly upregulated ICAM-1 expression in a dose-dependent manner. Most interestingly, the cytokine IL-6, which does not influence adhesion-molecule expression on other cells, significantly upregulated melanocyte and melanoma cell ICAM-1 expression. This effect was dose dependent and could be blocked by an IL-6 antibody. Irradiation with ultraviolet (UVB) light did not influence constitutive ICAM-1 expression on melanoma cells and melanocytes, but suppressed cytokine-induced ICAM-1 expression when cells were harvested 16 h after irradiation. These findings were further confirmed by Northern blot analysis, showing a marked accumulation of ICAM-1 mRNA after cytokine treatment, which was reduced by irradiation with UVB light. However, when UVB-exposed melanoma cells were cultured for at least 48 h induction of ICAM-1 expression was observed. These data indicate that, similar to other cells, ICAM-1 expression on melanoma cells and melanocytes is regulated by cytokines and that UVB light affects ICAM-1 expression on melanocytic cells in a biphasic manner.

Cytokine-Induced Expression of Intercellular Adhesion Molecule-1 (ICAM-1) in Cultured Human Oligodendrocytes and Astrocytes

We investigated the expression of intercellular adhesion molecule-1 (ICAM-1) on primary cultures of human adult oligodendrocytes and astrocytes. Under unstimulated conditions, low levels of ICAM-1 immunoreactivity were identified on both oligodendrocytes (less than 50%) and astrocytes (less than 30%). After 48 hours' exposure to immune mediators, such as culture supernatant of phytohemagglutinin (PHA)-stimulated lymphocytes, interferon gamma (IFN-gamma; 1,000 U/ml), tumor necrosis factor alpha (TNF-alpha; 2,000 U/ml), interleukin-1 alpha (IL-1 alpha; 1,000 U/ml) and lipopolysaccharide (LPS; 50 micrograms/ml), ICAM-1 expression on both cell types was markedly increased in terms of intensity and cell numbers. IFN-gamma and culture supernatant of PHA-stimulated lymphocytes were the most potent inducers of ICAM-1 among the mediators tested, while TNF-alpha, IL-alpha and LPS were less effective, although variations were observed among cultures derived from different donors. Cytokine-induced expression of ICAM-1 on glial cells may play a role in mediating lymphocyte-glial cell interactions at sites of inflammation in the central nervous system.