Induction of vascular cell adhesion molecule-1 expression by IL-4 in human aortic smooth muscle cells is not associated with increased nuclear NF-κB levels

Vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) are upregulated in vascular endothelial and smooth muscle cells by cytokines produced at sites of inflammation. The cytokine profile for induction of VCAM-1, however, is different for the two cell types. Tumor necrosis factor-α (TNF-α) induced both VCAM-1 and ICAM-1 expression in human umbilical vein endothelial cells (HUVECs; ED₅₀ ∼ 300 and 30 U/ml, respectively). TNF-α and interleukin-1β (IL-1β) stimulated cell surface ICAM-1 expression, but not VCAM-1 expression, in human aortic smooth muscle cells (HASMCs). Conversely, IL-4 was a potent VCAM-1 inducer in HASMCs (ED₅₀ ∼ 100 pg/ml) but did not induce ICAM-1 expression. Nuclear extracts from IL-4-treated cells were compared with untreated cells for relative nuclear factor-kappa B (NF-κB) levels by using an electrophoretic mobility shift assay and surface plasmon resonance techniques. No significant increase in nuclear NF-κB DNA binding activity was detected in IL-4-treated HASMCs by either method of analysis. IL-1β and TNF-α stimulated nuclear NF-κB levels by about fourfold and fivefold, respectively, in HASMCs. The antioxidant pyrrolidine dithiocarbamate (PDTC) similarly inhibited VCAM-1 upregulation in HASMCs incubated with IL-4 and in HUVECs incubated with TNF-α (IC₅₀s of 25 and 40 μM, respectively). These data suggest that a significant increase in nuclear NF-κB levels is not necessary or sufficient for VCAM-1 upregulation in HASMCs and does not determine the relative sensitivity to inhibition of gene expression by PDTC. J. Cell. Physiol. 180:381–389, 1999. © 1999 Wiley-Liss, Inc.     

Aspirin prevents adhesion of T lymphoblasts to vascular smooth muscle cells

In the development of atherosclerosis, inflammatory cells adhere to and migrate into the vascular walls by interacting with vascular smooth muscle cells. To investigate the mechanism of aspirin’s anti-atherogenic activity, we examined whether aspirin inhibits the adhesion of lymphocytes to human aortic smooth muscle cells (AoSMC). Aspirin inhibited T-cell adhesion to AoSMC activated by interleukin 1β (IL-1β) in a dose-dependent manner. Antibodies to the adhesion molecules ICAM-1 or VCAM-1, but not to E-selectin, prevented T-cell adhesion. ICAM-1 and VCAM-1 expression stimulated by IL-1β was reduced by the treatment with aspirin, whereas the expression of E-selectin was unaffected. Nuclear factor κB (NF-κB) activity was enhanced by IL-1β and reduced by aspirin, indicating that decreased ICAM-1 and VCAM-1 expression was due to reduced NF-κB activity.Thus, aspirin inhibits the adhesion of Jurkat T cells to IL-1β-activated AoSMC by reducing NF-κB activity and decreasing expression of ICAM-1 and VCAM-1, and may prevent the development of atherosclerosis.     

Docosahexaenoic acid attenuates VCAM-1 expression and NF-κB activation in TNF-α-treated human aortic endothelial cells

This study was conducted to test the hypothesis that n-3 polyunsaturated fatty acids are able to down-regulate expression of adhesion molecules and nuclear factor-κB (NF-κB) activation in vascular endothelial cells, in addition to reducing atherosclerotic lesions in vivo. We report here that docosahexaenoic acid (DHA) reduces atherosclerotic lesions in the aortic arteries of apolipoprotein E knockout (apoE^-/-) mice. Consistent with the observation in animal study, DHA inhibited THP-1 cell adhesion to tumor necrosis factor α (TNF-α)-activated human aortic endothelial cells (HAECs). Expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) on the cell surface of HAECs was determined by cell-surface enzyme-linked immunosorbent assay. DHA and eicosapentaenoic acid decreased VCAM-1 expression in a dose-dependent manner in TNF-α treated HAECs, while cis-linoleic acid and arachidonic acid did not have any significant effect on either VCAM-1 or ICAM-1 expression. Moreover, DHA significantly reduced VCAM-1 protein expression in the cell lysates of TNF-α-treated HAECs, as determined by Western blot analysis. In line with NF-κB signaling pathway, DHA suppressed the TNF-α-activated IκBα phosphorylation and degradation as well as IκB kinase-β phosphorylation. Subsequently, translocation of the NF-κB (p50/p65) and AP-1 (c-Fos/c-Jun) subunits was down-regulated by DHA in the nucleus of HAECs. These results suggest that DHA negatively regulates TNF-α-induced VCAM-1 expression through attenuation of NF-κB signaling pathway and AP-1 activation. This study provides evidence that DHA may contribute to the prevention of atherosclerosis and inflammatory diseases in vivo.     

Flavonoids of <Emphasis Type="Italic">Rosa roxburghii</Emphasis> Tratt offers protection against radiation induced apoptosis and inflammation in mouse thymus

The present study evaluated the protective effect of the natural compound flavonoids of Rosa roxburghii Tratt (FRT) against γ-radiation-induced apoptosis and inflammation in mouse thymus cells in vivo and in vitro. Thymus cells and mice were exposed to ⁶⁰Co γ-ray at a dose of 6 Gy. The radiation treatment induced significant cell apoptosis and inflammation. Radiation increased the expressions of cleaved caspase 3/8–10, AIF, and PARP-1, and FRT could mitigate their activation and inhibit subsequent apoptosis in the thymus both in vitro or in vivo. Irradiation increased the mRNA expression of ICAM-1/VCAM-1, IL-1α/IL-6 and TNF-α/NF-κB. Our results also indicated that FRT alleviated gene expression of some inflammatory factors such as ICAM-1/VCAM-1, TNF-α/NF-κB, but not IL-1α/IL-6. Irradiation increased the protein expression levels of ICAM-1/VCAM-1, IL-1α/IL-6 and TNF-α/NF-Κb, and our results also indicated that FRT alleviated protein level expression of certain inflammatory factors such as ICAM-1, IL-1α/IL-6, TNF-α/NF-κB, but not VCAM-1. Our results suggested that FRT enhanced radioprotection at least partially by regulating caspase 3/8–10, AIF, and PARP-1 to reduce apoptosis and by regulating ICAM-1, IL-1α/IL-6, TNF-α/NF-κB to reduce inflammation.     

Cryptotanshinone inhibits oxidized LDL-induced adhesion molecule expression via ROS dependent NF-κB pathways

Adhesion molecules, such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin, play important roles in the initial stage of atherosclerosis. Cryptotanshinone (CPT), a natural compound isolated from Salvia miltiorrhiza Bunge, exhibits anti-atherosclerotic activity although the underlying mechanisms remain elusive. In this study, the protective effect of CPT against oxidized low-density lipoprotein (ox-LDL)-induced adhesion molecule expression was investigated in human umbilical vein endothelial cells. Ox-LDL significantly induced ICAM-1, VCAM-1, and E-selectin expression at the mRNA and protein levels but reduced eNOS phosphorylation and NO generation, which were reversed by CPT pretreatment. Sodium nitroprusside, a NO donor, N-acetyl-L-cysteine (NAC), a reactive oxygen species (ROS) scavenger, and BAY117082, a NF-κB inhibitor, inhibited ox-LDL-induced ICAM-1, VCAM-1, and E-selectin expression. Ox-LDL-induced ROS production was significantly inhibited by CPT and NAC. Furthermore, ox-LDL activated the NF-κB signaling pathway by inducing phosphorylation of IKKβ and IκBα, promoting the interaction of IKKβ and IκBα, and increasing p65 nuclear translocation, which were significantly inhibited by CPT. In addition, CPT, NAC, and BAY117082 inhibited ox-LDL-induced membrane expression of ICAM-1, VCAM-1, E-selectin, and endothelial–monocyte adhesion and restored eNOS phosphorylation and NO generation. Results suggested that CPT inhibited ox-LDL-induced adhesion molecule expression by decreasing ROS and inhibiting the NF-κB pathways, which provides new insight into the anti-atherosclerotic mechanism of CPT.     

Omentin inhibits TNF-α-induced expression of adhesion molecules in endothelial cells via ERK/NF-κB pathway

In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-α (TNF-α) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-α-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibited TNF-α-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-α-activated signal pathway of nuclear factor-κB (NF-κB) by preventing NF-κB inhibitory protein (IκBα) degradation and NF-κB/DNA binding activity. Omentin pretreatment significantly inhibited TNF-α-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-α-induced NF-κB activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-α. These results suggest that omentin may inhibit TNF-α-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-κB pathway.     

Identification of a new Mpl-interacting protein,Atp5d

Nuclear factor κB (NF-κB) plays an important role in the regulation of inflammatory proteins. However, it is unclear whether the NF-κB/intercellular adhesion molecule-1 (ICAM-1) pathway is involved in the adhesion of neutrophils and renal injury after hypoxia–ischemia (HI) in neonates. In this report we investigated whether NF-κB and its downstream molecule ICAM-1 were involved in renal injury induced by postasphyxial serum (PS) from neonates. Human renal proximal tubular (HK-2) cells were preincubated with 10 % fetal calf serum (control), 20 % neonatal PS, or 20 % PS plus pyrolidine dithiocarbamate (PDTC). The expression of IκBα, NF-κB p65, and ICAM-1 in HK-2 cells was determined by Western blot and/or immunohistochemistry. Nuclear translocation of NF-κB p65 in HK-2 cells was detected by immunofluorescence and Western blot. The ICAM-1 mRNA was determined by RT-PCR. Then HK-2 cells were cultured with neutrophils from neonates with asphyxia. After HK-2 cells had been cultured with neutrophils, we detected myeloperoxidase (MPO) activity, the leakage rate of lactate dehydrogenase (LDH), and cell viability. We found that PS preincubation resulted in significantly decreased IκBα expression and increased expression of NF-κB and ICAM-1, and facilitated the nuclear translocation of NF-κB in HK-2 cells. PS preincubation increased MPO activity, leading to elevated leakage rates of LDH and decreased cell viability after neutrophil exposure. Furthermore, the inhibition of NF-κB activity by PDTC significantly upregulated IκBα expression, decreased NF-κB and ICAM-1 expression, downregulated the nuclear translocation of NF-κB, and decreased MPO activity. This leads to decreased leakage rates of LDH and increased cell viability after neutrophil exposure. Our findings suggest that NF-κB/ICAM-1 pathway may be involved in neutrophil–endothelial interactions and neonatal renal injury after HI.     

Salusin-β accelerates inflammatory responses in vascular endothelial cells via NF-κB signaling in LDL receptor-deficient mice in vivo and HUVECs in vitro

The bioactive peptide salusin-β is highly expressed in human atheromas; additionally, infusion of antiserum against salusin-β suppresses the development of atherosclerosis in atherogenic mice. This study examined the roles of salusin-β in vascular inflammation during atherogenesis. Infusion of antiserum against salusin-β attenuated the induction of VCAM-1, monocyte chemoattractant protein (MCP)-1, and IL-1β and as well as nuclear translocation of NF-κB in aortic endothelial cells (ECs) of LDL receptor-deficient mice, which led to the prevention of monocyte adhesion to aortic ECs. In vitro experiments indicated that salusin-β directly enhances the expression levels of proinflammatory molecules, including VCAM-1, MCP-1, IL-1β, and NADPH oxidase 2, as well as THP-1 monocyte adhesion to cultured human umbilical vein ECs (HUVECs). Both salusin-β-induced VCAM-1 induction and monocyte/HUVEC adhesion were suppressed by pharmacological inhibitors of NF-κB, e.g., Bay 11-7682 and curcumin. Furthermore, the VCAM-1 induction was significantly prevented by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002, whereas it was accelerated by the ERK inhibitor, U-0126. Treatment of HUVECs with salusin-β, but not with salusin-α, accelerated oxidative stress and nuclear translocation of NF-κB as well as phosphorylation and degradation of IκB-α, an endogenous inhibitor of NF-κB. Thus, salusin-β enhanced monocyte adhesion to vascular ECs through NF-κB-mediated inflammatory responses in ECs, which can be modified by PI3K or ERK signals. These findings are suggestive of a novel role of salusin-β in atherogenesis.     

Sophocarpine exert protective effect against ox-LDL-induced endothelial damage via regulating NF-κB signaling pathway

ABSTRACT

Oxidized low-density lipoprotein (ox-LDL) was known to induce endothelial cell injury to the progression of atherosclerosis (AS). Sophocarpine (SPC), a compound of sophora alkaloids isolated from the plant Sophora alopecuroides, has been shown to exhibit various pharmacological activities. This study was designed to investigate the protective effect of SPC on ox-LDL-induced endothelial cells and explored its underlying mechanism. Our results show that SPC pre-incubation ameliorated ox-LDL-mediated HAECs cytotoxicity, DNA fragmentation, and apoptosis in a dose-dependent manner. Moreover, SPC significantly downregulated the mRNA or protein expression level of pro-inflammatory mediators (TGF-β, IL-6, IL-1β, TNF-α) and pro-inflammatory vascular adhesion molecules (VCAM-1, ICAM-1, and E-selectin). Mechanistically, SPC pre-treatment downregulated IκBα expression and inhibited translocation of NF-κB in ox-LDL-mediated HAECs, overexpression of NF-κB p65 counteracted the cytoprotective and anti-apoptotic effect of SPC, suggesting that its action is dependent on NF-κB signaling pathway. Collectively, SPC suppresses ox-LDL-induced HAECs injury by inhibiting the NF-κB signaling pathway.     

Cytokine and endothelial cell adhesion molecule expression in interleukin-10-deficient mice

The objectives of this study were to quantify cytokine mRNA levels and endothelial cell adhesion molecule message and protein expression in healthy wild-type and interleukin-10-deficient (IL-10(-/-)) mice that develop spontaneous and chronic colitis. We found that colonic message levels of IL-1, IL-6, tumor necrosis factor-alpha, interferon-gamma, lymphotoxin-beta, and transforming growth factor-beta were elevated in colitic mice 10- to 35-fold compared with their healthy wild-type controls. In addition, colonic message levels of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) were found to be increased 10-, 5-, and 23-fold, respectively, in colitic IL-10(-/-) mice compared with their wild-type controls. Immunoradiolabeling as well as immunohistochemistry revealed large and significant increases in vascular surface expression of colonic ICAM-1, VCAM-1, and MAdCAM-1 in the mucosa as well as the submucosa of the colons of colitic mice. These data are consistent with the hypothesis that deletion of IL-10 results in the sustained production of proinflammatory cytokines, leading to the upregulation of adhesion molecules and infiltration of mononuclear and polymorphonuclear leukocytes into the cecal and colonic interstitium.     

Sauchinone from Saururus chinensis protects vascular inflammation by heme oxygenase-1 induction in human umbilical vein endothelial cells

Sauchinone, a diastereomeric lignan isolated from the roots of Saururus chinensis (LOUR.) BAILL. (Saururaceae), is reported to exert a variety of biological activities such as hepatoprotective, anti-inflammatory actions and inhibitory effects on bone resorption. In this study, we investigated the effect of sauchinone in suppressing cell adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) expression in high glucose stimulated human umbilical vein endothelial cells (HUVEC). Sauchinone inhibited the phosphorylation and degradation of IκB-α, as well as the nuclear translocation of nuclear factor kappa B (NF-κB) p65 caused by the stimulation of high glucose. In addition, sauchinone induced heme oxygenase (HO)-1 expression through nuclear translocation of nuclear factor E2-related factor 2 in HUVEC. The effects of sauchinone on the high glucose-induced expression of VCAM-1 and ICAM-1 and nuclear translocation of NF-κB p65 were partially reversed by transfection of the cells with HO-1 siRNA. These findings suggest that sauchinone-induced HO-1 expression plays a key role in the vascular protective effects of sauchinone in HUVEC.     

Grape seed proanthocyanidin extracts prevent high glucose-induced endothelia dysfunction via PKC and NF-κB inhibition

In our study, it has been detected in vivo and in vitro that GSPE reversed high glucose-induced the increase of ICAM-1 and VCAM-1. It is shown that by western blotting detection, GSPE significantly inhibited the activation of NF-κB induced by high glucose while there was significant decrease of the expression of PKC with GSPE intervention. By adding the NF-κB blocker PDTC and the PKC inhibitor peptide 19–31(10^?6 M), no significant difference was found in the levels of VCAM-1 and ICAM-1 among GSPE group, the PKC inhibitor peptide 19–31-added GSPE group and the PDTC-added GSPE group. So the conclusion could be drawn that PKC inhibition must be involved in GSPE decreasing the level of ICAM-1 and VCAM-1.We proved for the first time that GSPE prevented high glucose-induced the increase of ICAM-1 and VCAM-1 by PKC and NF-κB inhibition. These findings show a novel mechanism of the action GSPE preventing endothelial dysfunction, which may have clinical application values.     

A novel role for interleukin-18 in adhesion molecule induction through NF kappa B and phosphatidylinositol (PI) 3-kinase-dependent signal transduction pathways

Interleukin-18 (IL-18) is a novel proinflammatory cytokine found in serum and joints of patients with rheumatoid arthritis (RA). We studied a novel role for IL-18 in mediating cell adhesion, a vital component of the inflammation found in RA and other inflammatory diseases. We examined the expression of cellular cell adhesion molecules E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) on endothelial cells and RA synovial fibroblasts using flow cytometry. Adhesion of the monocyte-like cell line HL-60 to endothelial cells was determined by immunofluorescence. IL-18 significantly enhanced ICAM-1 and VCAM-1 expression on endothelial cells and RA synovial fibroblasts. In addition, IL-18 induced E-selectin expression on endothelial cells and promoted the adhesion of HL-60 cells to IL-18-stimulated endothelial cells. Neutralizing anti-VCAM-1 and anti-E-selectin could completely inhibit HL-60 adherence to endothelial cells. IL-18-induced adhesion molecule expression appears to be mediated through nuclear factor kappa B (NF kappa B) and phosphatidyl-inositol 3 kinase (PI 3-kinase) since addition of inhibitors to either NF kappa B (pyrrolidine dithiocarbamate and N-acetyl-l-cysteine) or PI 3-kinase (LY294002) inhibited RA synovial fibroblast VCAM-1 expression by 50 to 60%. Addition of both inhibitors resulted in inhibition of VCAM-1 expression by 85%. In conclusion, the ability of IL-18 to induce adhesion molecule expression on endothelial cells and RA synovial fibroblasts indicates that IL-18 may contribute to RA joint inflammation by enhancing the recruitment of leukocytes into the joint. IL-18 requires NF kappa B as well as PI 3-kinase to induce VCAM-1 on RA synovial fibroblasts, suggesting that there may be two distinct pathways in IL-18-induced adhesion molecule expression.     

Preconditioning with endoplasmic reticulum stress mitigates retinal endothelial inflammation via activation of X-box binding protein 1

Endoplasmic reticulum (ER) stress is widely implicated in various pathological conditions such as diabetes. Previously, we reported that enhanced ER stress contributes to inflammation and vascular damage in diabetic and ischemia-induced retinopathy. However, the exact role of the signaling pathways activated by ER stress in vascular inflammation remains poorly understood. In the present study, we investigated the role of X-box binding protein 1 (XBP1) in retinal adhesion molecule expression, leukostasis, and vascular leakage. Exposure of human retinal endothelial cells to low dose ER stress inducers resulted in a robust activation of XBP1 but did not affect inflammatory gene expression. However, ER stress preconditioning almost completely abolished TNF-α-elicited NF-κB activation and adhesion molecule ICAM-1 and VCAM-1 expression. Pharmaceutical inhibition of XBP1 activation or knockdown of XBP1 by siRNA markedly attenuated the effects of preconditioning on inflammation. Moreover, loss of XBP1 led to an increase in ICAM-1 and VCAM-1 expression. Conversely, overexpression of spliced XBP1 attenuated TNF-α-induced phosphorylation of IKK, IκBα, and NF-κB p65, accompanied by decreased NF-κB activity and reduced adhesion molecule expression. Finally, in vivo studies show that activation of XBP1 by ER stress preconditioning prevents TNF-α-induced ICAM-1 and VCAM-1 expression, leukostasis, and vascular leakage in mouse retinas. These results collectively indicate a protective effect of ER stress preconditioning against retinal endothelial inflammation, which is likely through activation of XBP1-mediated unfolded protein response (UPR) and inhibition of NF-κB activation.     

The anti-atherosclerotic effect of tanshinone IIA is associated with the inhibition of TNF-α-induced VCAM-1, ICAM-1 and CX3CL1 expression

Tanshinone IIA is one of the major diterpenes in Salvia miltiorrhiza. The inhibitory effect of Tanshinone IIA on atherosclerosis has been reported, but the underlying mechanism is not fully understood. The present study aimed to study the anti-atherosclerosis effect of Tanshinone IIA on the adhesion of monocytes to vascular endothelial cells and related mechanism. Results showed that Tanshinone IIA, at the concentrations without cytotoxic effect, dose-dependently inhibited the adhesion of THP-1 monocytes to the TNF-α-stimulated human vascular endothelial cells. The expressions of cell adhesion molecules including VCAM-1, ICAM-1 and E-selectin were induced by TNF-α in HUVECs at both the mRNA and protein levels. The mRNA and protein expressions of VCAM-1 and ICAM-1, but not E-selectin, were both significantly suppressed by Tanshinone IIA in a dose dependent manner. In addition, the TNF-α-induced mRNA expression of fractalkine/CX3CL1 and the level of soluble fractalkine were both reduced by Tanshinone IIA. We also found that Tanshinone IIA significantly inhibited TNF-α-induced nuclear translocation of NF-κB which was resulted from the inhibitory effect of Tanshinone IIA on the TNF-α-activated phosphorylation of IKKα, IKKβ, IκB and NF-κB. As one of the major components of Salvia miltiorrhiza, Tanshinone IIA alone exerted more potent effect on inhibiting the adhesion of monocytes to vascular endothelial cells when compared with Salvia miltiorrhiza. All together, these results demonstrate a novel underlying mechanism for the anti-inflammatory effect of Tanshinone IIA by modulating TNF-α-induced expression of VCAM-1, ICAM-1 and fractalkine through inhibition of TNF-α-induced activation of IKK/NF-κB signaling pathway in human vascular endothelial cells.     

Effects of antioxidants and nitric oxide on TNF-alpha-induced adhesion molecule expression and NF-kappaB activation in human dermal microvascular endothelial cells

Cell adhesion molecules expressed on endothelial cells in inflamed skin appear to be controlled by the actions of cytokines and reactive oxygen species. However, molecular mechanisms of the expression of adhesion molecules during skin inflammation are currently not well understood. To evaluate the role of antioxidants and nitric oxide in modulating inflammatory processes in the skin, we examined the effects of pyrrolidine dithiocarbamate (PDTC, 0.1 mM) and spermine NONOate (Sper-NO, 1 mM) on adhesion molecule expression and nuclear factor kappa B (NF-kappaB) activation induced by TNF-alpha (10 ng/ml) in cultured human dermal microvascular endothelial cells (HDMEC). Treatment of cells with TNF-alpha for 4 h significantly induced the surface expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1). Treatment with TNF-alpha for 8 h significantly induced the surface expression of E-selectin, ICAM-1 and vascular cell adhesion molecule-1 (VCAM-1). The up-regulation of these adhesion molecules was suppressed significantly by pretreatment with PDTC or Sper-NO for 1 h. The mRNA expression of E-selectin, ICAM-1 and VCAM-1, and activation of NF-kappaB induced by TNF-alpha for 2 h were significantly decreased by the above two pretreatments. N-acetylcysteine (10 mM) and S-nitroso-N-acetylpenicillamine (1 mM) had no significant inhibitory effects on the cell surface and mRNA expression of these adhesion molecules stimulated by TNF-alpha. These findings indicate that both cell surface and mRNA expression of adhesion molecules in HDMEC induced by TNF-alpha are inhibited significantly by pretreatment with PDTC or Sper-NO, possibly in part through blocking the activation of NF-kappaB. These results suggest a potential therapeutic approach using antioxidant agents or nitric oxide pathway modulators in the treatment of inflammatory skin diseases.