保护性基因A20在血管内皮细胞中的诱导表达

目的：研究人Th2细胞因子对牛主动脉内皮细胞（BAEC）诱导表达保护性基因A20的影响，探讨人Th2细胞因子对异种VEC具有保护效应的机制。方法：建立BAEC的体外培养体系，用浓度为20μg/L的各Th2细胞因子（hIL-4、hIL-10、hIL-13）分别孵育BAEC2h后，再与肿瘤坏死因子α（TNF-α、4μg／L）共孵育24h后收集细胞；应用RT-PCR方法检测各组BAEC中A20mRNA的表达。结果：用Th2细胞因子在一定浓度内预处理BAEC后，能明显诱导BAEC表达保护性基因A20。结论：Th2细胞因子对BAEC的保护作用与Th2细胞因子诱导保护性基因A20在BAEC中的表达有关。     

人白介素10对异种内皮细胞保护作用的研究

目的：研究人白介素10(HIL-10)对活化的牛主动脉内皮细胞(BAECs)的保护作用，为HIL-10用来减轻异种排斥反应、诱导异种移植免疫耐受提供实验依据。方法：用不同浓度的HIL-10(2、5、10、20、40ng/ml)孵育BAECs2小时后，再与肿瘤坏死因子a(TNF-a，ng/ml)共孵育6小时或18小时；应用细胞-酶联免疫吸附分析方法(Cell-ELISA)检测细胞表面的E-seleetin和ICAM-1的表达。用MTT方法测定药物对细胞活性的影响。结果：用HIL-10在一定浓度内预处理BAECs后，能明显抑制TNF-a诱导的E-seleetin与ICAM-1的表达，并呈现一定的剂量依赖性。用MTT方法测定细胞活性的实验表明，各实验组细胞活性与对照组无明显差异性。结论：HIL-10能明显抑制TNF-a活化的BAECs表达Bseleetin与ICAM-1；HIL-10对BAECs有一定的保护作用。     

TNF-α对内皮细胞白介素-8基因表达的影响

IL-8作为一种趋化细胞因子在炎症反应中具有重要作用,其在内皮细胞内的表达受多种细胞因子的调节。本文用TNF-α孵育培养的人脐静脉内皮细胞不同时间后,用RT-PCR法检测内皮细胞内IL-8mRNA的表达,并用免疫细胞化学染色法检测内皮细胞内NF-κB的激活。结果发现(1)未用TNF-α孵育的内皮细胞IL-8表达量很少,TNF-α孵育1小时后IL-8表达明显增加,3h进一步增加;6hIL-8表达降低,9h进一步降低至基础水平;(2)未用TND-α孵育的内皮细胞核NF-κBp65免疫细胞化学染色呈阴性,NF-α孵育1,3h后NF-κBp65免疫细胞化学染色呈阳性,6h时后呈弱阳性,9h后呈阴性。提示TNF-α可诱导内皮细胞表达IL-8并可激活内皮细胞内NF-κB,二者的时相过程基本一致。作者认为TNF-α诱导IL-8在内皮细胞内表达可能与转录因子NF-κB的激活有关。     

蜂胶水提物对血管内皮细胞黏附分子表达的影响

目的:采用TNF-α诱导体外培养的人脐静脉内皮细胞(HUCECs)活化,观察蜂胶水提物(WEP)对血管内皮细胞黏附分子表达的影响,从而探讨蜂胶抗动脉粥样硬化的作用及其机制。方法:用50μg/L TNF-α诱导体外培养HUVECs损伤,用50 mg/L、100 mg/L、200 mg/L WEP分别进行干预6 h、12 h、24 h,利用流式细胞仪检测HUVEC表面ICAM-1和VCAM-1表达。结果:与对照组比较,模型组ICAM-1和VCAM-1荧光强度明显升高(P0.01)。与模型组比较,100 mg/L WEP组和200 mg/L WEP组ICAM-1和VCAM-1荧光强度明显降低(P0.01)。不同浓度WEP组ICAM-1和VCAM-1荧光强度随WEP浓度的增加下调。析因分析结果显示,用200 mg/L WEP和氟伐他汀钠(FS)联合预处理组与单一药物预处理组比较,ICAM-1和VCAM-1活性明显降低(P0.01)。结论:WEP能够减少ICAM-1和VCAM-1的表达,且在一定的范围内,有随WEP浓度升高和作用时间延长效应增强的趋势。WEP与FS联合用药,对抑制ICAM-1和VCAM-1表达有协同作用。     

脂氧素A4拮抗肿瘤坏死因子α对系膜细胞Jak1/STAT3途径的活化

目的：验证脂氧素A4(LXA4) 是否抑制肿瘤坏死因子α(TNFα) 所致的大鼠肾小球系膜细胞的增殖，并探讨其作用中信号转导的分子机制。 方法： 对体外培养的大鼠肾小球系膜细胞，用不同浓度的LXA4 预刺激，再加入TNFα共同孵育，或单用TNFα刺激系膜细胞。用MTT渗入法检测细胞的增殖。用凝胶电泳迁移率试验（EMSA）检测信号转导子和转录激活子-3（STAT3）的活性。用RT-PCR法检测细胞周期素E的mRNA表达。用Western blotting法检测细胞周期素E的蛋白表达量。结果： LXA4呈剂量依赖性地抑制TNFα诱导的肾小球系膜细胞的增殖、STAT3结合活性增加、细胞周期素E mRNA表达与蛋白合成的亢进。结论： LXA4能够抑制TNFα所致的大鼠系膜细胞的增殖，其机制可能是阻断Jak1/STAT3信号转导途径。     

NF-kB介导脂氧素A4拮抗TNF-α所致的系膜细胞白介素的合成

为研究脂氧素A4(LXA4)拈抗肿瘤坏步E因子α(TNF-α)对肾小球系膜细胞的白介素(IL）-β(IL-1β)、IL-6合成的作用。对体外培养大鼠肾小球系膜细胞，用不同浓度的LXA4预刺激，再加入TNF-α共同孵育；或单用TNF-α刺激肾小球系膜细胞。在孵育后用ELISA法检测培养上清中的IL-1β,IL-6蛋白表达量；用RT-PCR法检测IL-1β、IL-6的mRNA表达量。应用凝胶电泳迁移率试验（EMSA)测定核因子-kB(NF-KB)的DNA结合活性。结果发现，LXA4呈剂量依赖性地抑制TNF-α诱导的肾小球系膜细胞IL-1β和IL-6蛋白的合成与mRNA表达，抑制NF-kB的DNA结合活性。说明LXA4通过下调NF-kB的DNA结合活性，拮抗TNF-α对肾小球系膜细胞的IL-1β、IL-6合成的促进作用。     

NF-κB介导脂氧素A4拮抗TNF-α所致的系膜细胞白介素的合成

为研究脂氧素A4(LXA4)拮抗肿瘤坏死因子α(TNF-α)对肾小球系膜细胞的白介素(IL)-1β(IL-1β)、IL-6合成的作用。对体外培养大鼠肾小球系膜细胞,用不同浓度的LXA4预刺激,再加入TNF-α共同孵育;或单用TNF-α刺激肾小球系膜细胞。在孵育后用ELISA法检测培养上清中的IL-1β、IL-6蛋白表达量;用RT-PCR法检测IL-1β、IL-6的mRNA表达量。应用凝胶电泳迁移率试验(EMSA)测定核因子-κB(NF-κB)的DNA结合活性。结果发现,LXA4呈剂量依赖性地抑制TNF-α诱导的肾小球系膜细胞IL-1β和IL-6蛋白的合成与mRNA表达,抑制NF-κB的DNA结合活性。说明LXA4通过下调NF-κB的DNA结合活性,拮抗TNF-α对肾小球系膜细胞的IL-1β、IL-6合成的促进作用。     

免疫球蛋白IgG对TNF-α诱导的内皮细胞损伤的作用及其机制

目的探讨免疫球蛋白IgG对TNF-α诱导的内皮细胞黏附分子、细胞因子的表达及其作用机制。方法不同剂量的免疫球蛋白IgG预处理内皮细胞30 min,再加入TNF-α孵育2 h,或不同剂量的IgG与TNF-α预孵育30 min后加入内皮细胞孵育2 h,RT-PCR及实时定量PCR检测黏附分子ICAM-1、VCAM-1、E-Selectin及细胞因子IL-6、GM-CSF、IFN-β的mRNA表达;进一步应用Western blot检测黏附分子的蛋白表达及免疫球蛋白IgG自身抗体的表达情况。结果 IgG预处理内皮细胞再加入TNF-α或IgG与TNF-α预孵育后加入内皮细胞,IgG均可剂量依赖性地抑制了TNF-α诱导的黏附分子(ICAM-1、VCAM-1、E-Selectin)及细胞因子(IL-6、GM-CSF、IFN-β)的表达,IgG含有anti-IFN-γ,anti-TNF-α,anti-MCP-1的自身抗体。结论 IgG对TNF-α诱导的内皮细胞损伤有治疗作用,其机制与抑制内皮细胞分泌的黏附分子,细胞因子的表达及IgG存在抗细胞因子的自身抗体有关。     

烟酸姜黄素酯抑制LP S 诱导的HUVECs分泌炎性细胞因子与内质网应激

目的探讨烟酸姜黄素酯(NC)对LPS诱导的人脐静脉内皮细胞(HUVECs)分泌细胞因子的影响及其作用机制。方法体外培养HUVECs,用不同浓度NC孵育HUVECs 24 h。Western blot检测AMPK的磷酸化;用siRNA沉默磷酸腺苷活化蛋白激酶(AMPK)表达后,观察其对脂多糖(LPS)诱导NF-κB p65磷酸化、黏附分子表达、细胞培养上清中TNF-α和MCP-1分泌,以及内质网应激标志分子IRE-1、eIF2α和CHOP表达水平的影响。结果 10～20μmol/L NC处理HUVECs 24 h后,AMPK的磷酸化水平显著增高(P0.05),同时p65磷酸化有所减轻。沉默AMPK后,NC对NF-κB的抑制效应明显减弱(P0.05)。同时,NC处理后,LPS所致ICAM-1,VCAM-1和E选择素等黏附分子表达明显降低(P0.05),单核巨噬细胞THP-1与HUVECs的黏附作用也明显减轻,培养上清中TNF-α和MCP-1明显减少(P0.05)。siRNA沉默AMPK后,上述效应有所减弱(P0.05)。NC处理后可下调LPS所致的内质网应激标志分子IRE-1、eIF2α和CHOP的表达水平。而干扰AMPK表达后,可明显削弱NC对这些分子的抑制效应(P0.05)。结论 NC可抑制LPS诱导HUVECs表达和分泌黏附分子及细胞因子,并在一定程度上抑制内质网应激,其机制可能与激活AMPK有关。     

Expression of ICAM-1, VCAM-1, E-selectin and TNF-alpha on the endothelium of femoral and iliac arteries in thromboangiitis obliterans

Immunohistochemical light and electron microscopical analysis of surgical biopsies obtained from femoral and iliac arteries of patients with thromboangiitis obliterans (TAO) were performed to investigate the presence of tumour necrosis factor-alpha (TNF-alpha) and expression of the endothelial cell adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Expression of ICAM-1, VCAM-1 and E-selectin was increased on endothelium and some inflammatory cells in the thickened intima in all TAO patients. Ultrastructural immunohistochemistry revealed contacts between mononuclear blood cells and ICAM-1-, and E-selectin-positive endothelial cells. These endothelial cells showed morphological signs of activation. The present data indicate that endothelial cells are activated in TAO and that vascular lesions are associated with TNF-alpha secretion by tissue-infiltrating inflammatory cells, ICAM-1-, VCAM-1- and E-selectin expression on endothelial cells and leukocyte adhesion via their ligands. The preferential expression of inducible adhesion molecules in microvessels and mononuclear inflammatory cells suggests that angiogenesis contributes to the persistence of the inflammatory process in TAO.     

Effect of ultraviolet light on the expression of adhesion molecules and T lymphocyte adhesion to human dermal microvascular endothelial cells

In order to determine the effect of ultraviolet radiation (UVR) on the cell adhesion molecules expressed in human dermal microvascular endothelial cells (HDMEC), the cells were exposed to varying UVR doses and the cell surface was examined for expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM- 1), and E-selectin. The effect of UVB irradiation on the binding of T lymphocytes to HDMEC was also examined. UVA irradiation did not affect the surface expression of ICAM-1, VCAM-1, or E-selectin on the HDMEC. However, following UVB exposure, ELISA demonstrated a significant increase in the baseline ICAM-1 cell surface expression on the HDMEC. However, no induction of either E-selectin or VCAM-1 was noted. UVB also significantly augmented ICAM-1 induction by IL-1alpha and TNF-alpha. VCAM-1 was induced by stimulating HDMEC with IL-1alpha following a UVB irradiation dose of 100 mJ/cm2. Flow cytometric analysis of the HDMEC stimulated with IL-1alpha for 24h demonstrated that 12% of the cells expressed VCAM-1 but either IL-1alpha or UVB irradiation alone failed to induce VCAM-1 expression. Enhancement of T cell-HDMEC binding by IL-1alpha or TNF-alpha treatment was not significantly affected after UVB irradiation. This study demonstrated that UVB irradiation can alter ICAM-1 and VCAM-1 expression on the HDMEC surface and that augmentation of ICAM-1 expression and the IL-1alpha-dependent induction of VCAM-1 following UVB exposure might be important steps in the pathogenesis of sunburn.     

丹皮酚通过抑制NF-κB信号通路下调高脂血清诱导的人脐静脉内皮细胞黏附分子的表达

目的：观察丹皮酚对高脂损伤人脐静脉内皮细胞（HUVECs）核因子-κB（NF-κB）的活化及细胞黏附分子表达的影响,探讨丹皮酚抗动脉粥样硬化的分子机制。方法：以培养HUVECs作为靶细胞,用高脂血清制备损伤模型。采用MTT法检测细胞活性;RT-PCR法检测NF-κB p65 mRNA的表达;Western blotting法检测κB 抑制蛋白α（IκB-α）、细胞间黏附分子-1（ICAM-1）和E-选择素的蛋白表达。结果：丹皮酚能使高脂损伤的HUVECs存活率增加,形态趋于正常;降低NF-κB p65 mRNA的表达,提高IκB-α的表达;下调ICAM-1和E-选择素的蛋白表达。结论：丹皮酚通过抑制血管内皮细胞NF-κB/IκB通路,下调ICAM-1和E-选择素的表达,减少炎症反应,这可能是丹皮酚抗动脉粥样硬化的机制之一。     

脓毒症大鼠肺血管内皮细胞、细胞间粘附分子1和E-选择素的变化及其意义

目的:观察脓毒症大鼠肺血管内皮细胞(VEC)、细胞间黏附分子1和E-选择素的变化特点并探讨其意义.方法:60只SD大鼠随机分成对照组和脓毒症组.以脂多糖(LPS)静脉注射制备大鼠脓毒症模型,采用逆转录聚合酶链反应(RT-PCR)和免疫组织化学方法研究ICAM-1和E-选择素的表达;用Hoechest染色评价肺VEC凋亡;用电子显微镜观察肺VEC.结果:脓毒症组大鼠肺ICAM-1 mRNA和ICAM-1蛋白的表达与对照组比较明显增加(P<0.01),脓毒症组ICAM-1 mRNA和ICAM-1蛋白的表达6小时增高,24小时达到高峰;E-选择素表达6小时达高峰,以后逐渐下降,24小时后降至对照组相同水平.脓毒症组肺VEC随着制模时间的延长,坏死和凋亡显著增加(P<0.01),电子显微镜观察也得到证实.结论:脓毒症大鼠肺ICAM-1和E-选择素的表达明显增加,可能导致肺VEC的坏死和凋亡以及急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)的发生.     

Modulation of adhesion molecule expression on endothelial cells after induction by lipopolysaccharide-stimulated whole blood

The relative contribution of the pro-inflammatory cytokines tumour necrosis factor (TNF)-alpha and interleukin (IL)-1 beta and the lipopolysaccharide (LPS)-induced pathways that result in endothelial activation during sepsis are not fully understood. We have examined the effects of plasma obtained from LPS-treated human whole blood on the expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) on human endothelial cells. Stimulation of blood with 10 pg/ml of LPS is sufficient to produce plasma that induces E-selectin and ICAM-1 expression, while direct induction by LPS alone requires a 100-fold higher concentration. Characteristics for the plasma-induced adhesion molecule expression were similar to the LPS-induced production of TNF-alpha and IL-1 beta in blood. A complete inhibition of E-selectin and ICAM-1 expression was observed when antibodies against TNF-alpha and IL-1 beta were added to plasma prior to the incubation to endothelial cultures. Significant inhibition was even observed if antibodies were added to the cultures up until 3 h after LPS-conditioned plasma. The plasma-induced adhesion molecule response could also be prevented with inhibitors of nuclear factor (NF)-kappaB, such as pyrollidine dithiocarbamate. These findings emphasize the central role of TNF-alpha and IL-1 beta in LPS-induced endothelial activation and suggest that simultaneous neutralization of these cytokines or their common pathways may, even after the initial stimulus, prevent endothelial response during sepsis.     

Differential influences of bFGF and VEGF on the expression of vascular cell adhesion molecule-1 on human umbilical vein endothelial cells]

A fundamental feature of inflammation includes angiogenesis, adhesion of leukocytes to vascular endothelium, and entry of leukocytes into inflamed tissues. Recent studies have suggested that angiogenesis and cellular adhesion may be mutually linked processes. Both basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) have been shown to facilitate angiogenesis. However, their roles in the expression of adhesion molecules on the endothelial cells have not been clarified. The current studies therefore examined the effect of bFGF and VEGF on the expression of vascular cell adhesion molecule-1 (VCAM-1) on human umbilical vein endothelial cells (HUVEC) stimulated with tumor necrosis factor alpha (TNF-alpha). HUVEC (1 x 10(4)/well) were incubated in a 96 well microtiter plate with culture medium containing endothelial cell growth supplement (ECGS) for 24 h. After the incubation, culture medium was replaced by ECGS free culture medium with or without TNF-alpha (10 ng/ml), bFGF (10 ng/ml) and VEGF (10 ng/ml), and the culture was further carried out for additional 24 h. The expression of VCAM-1, E-selectin, and intercellular adhesion molecule-1 (ICAM-1) was measured by cell ELISA and the proliferation of HUVEC was measured by MTT colorimetric assay. Soluble VCAM-1 (sVCAM-1) in the supernatants were assessed by ELISA. Although, both bFGF and VEGF supported the proliferation of HUVEC, bFGF, but not VEGF, selectively suppressed the expression of VCAM-1 on HUVEC stimulated with TNF-alpha. The expression of ICAM-1 and E-selectin induced by TNF-alpha was not inhibited by either bFGF or VEGF. In addition, bFGF also decreased the levels of sVCAM-1 in the supernatants of TNF-alpha stimulated HUVEC. The data indicate that bFGF, but not VEGF, suppresses the production of VCAM-1 by HUVEC under stimulation with TNF-alpha. These results therefore suggest that angiogenic cytokines bFGF and VEGF play different roles in the regulation of the expression of adhesion molecules on endothelial cells under inflammation.     

E-选择素预处理对大鼠脑缺血-再灌注损伤的影响

目的：研究E-选择素鼻粘膜耐受对大鼠脑缺血-再灌注损伤的作用及其机制。方法:E-选择素或PBS单程诱导耐受或加强诱导耐受48 h后,用改良的Zea Longa线栓法制备大鼠大脑中动脉缺血模型,缺血2 h再灌注22 h后,流式细胞仪测定血中CD3+CD4+T细胞及CD3+CD8+T细胞含量,TTC染色法测定脑梗死体积,RT-PCR检测脑梗死区E-选择素、细胞间黏附分子-1（ICAM-1）、淋巴细胞功能相关抗原-1（LFA-1）的表达,黄嘌呤氧化酶法检测脑组织中SOD水平。结果:E-选择素单程诱导耐受组CD3+CD4+T细胞与CD3+CD8+T细胞比值增加（P<0.05）。与其它组相比,E-选择素加强诱导耐受组脑梗死体积减小了40.87%（P<0.05）, CD3+CD8+T细胞所占比例减小、CD3+CD4+T细胞与CD3+CD8+T细胞比值增高（P<0.05）,脑组织中SOD水平升高(P<0.05),E-选择素、ICAM-1表达减少（P<0.05）,LFA-1表达有减少趋势。结论:E-选择素鼻黏膜耐受诱导脑缺血耐受可减轻脑缺血-再灌注损伤,其作用机制与CD8+ T细胞减少,CD4+T细胞与CD8+T细胞比值增加、SOD水平升高及E-选择素、ICAM-1表达减少有关。     

Effect of glucocorticosteroids on tumour necrosis factor-α-induced intercellular adhesion molecule-1 expression in cultured primary human nasal epithelial cells

OBJECTIVE: In order to confirm the direct effect of glucocorticosteroids on epithelial intercellular adhesion molecule-1 (ICAM-1) expression, we examined ICAM-1 expression on primary cultured human nasal epithelial cells (HNECs) at both protein and mRNA levels. MATERIAL AND METHODS: HNECs were stimulated with recombinant human TNF-alpha (20 pg/mL-20 ng/mL) for specified time periods (0, 12, 24, and 48 h) and ICAM-1 mRNA and the soluble ICAM-1 (sICAM-1) concentrations were measured by quantitative RT-PCR and ELISA, respectively. We also evaluated surface expression of ICAM-1 by flow cytometry 48 h after stimulation and determined the effect of dexamethasone (DEX) on TNF-alpha-induced ICAM-1 expression. RESULTS: Significant increases in ICAM-1 gene expression in HNECs were initially detected at 24 h, peaking at 48 h after the stimulation. The TNF-mediated-ICAM-1 mRNA and ICAM-1 surface expression at 48 h was significantly inhibited by co-incubation with human recombinant soluble TNF receptor I. Similarly, TNF-alpha-induced release sICAM-1 occurred in a time- and concentration-dependent manner. DEX 10(-6) M attenuated the TNF-alpha-induced ICAM-1 expression at mRNA and protein levels. CONCLUSIONS: Our finding suggests a potential role for topical steroids in allergic rhinitis in suppressing inflammatory reactions in the nasal mucosa by regulating ICAM-1 expression on nasal epithelium.     

Synergistic effect of SCF and TNF-alpha on the up-regulation of cell-surface expression of ICAM-1 on human leukemic mast cell line (HMC)-1 cells

Intercellular adhesion molecule-1 (ICAM-1) has been shown to play crucial roles in mast cell interaction with other inflammatory cells and recruitment into the inflamed tissue. In the present study, human mast cell line-1 (HMC-1) was stimulated with different cytokines including stem cell factor (SCF), tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-13, IL-18, and IL-25. Cell-surface expression of ICAM-1 was assessed by flow cytometry. To elucidate the intracellular signal transduction regulating the ICAM-1 expression, phosphorylated extracellular signal-regulated kinase (ERK), phosphorylated p38 mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-kappaB translocation were assessed by enzyme-linked immunosorbent assay. Results showed that SCF, TNF-alpha, and IL-13 but not IL-18 and IL-25 could up-regulate the surface expression of ICAM-1 on HMC-1 cells. A synergistic effect of SCF and TNF-alpha on ICAM-1 expression was demonstrated. This synergistic effect was shown to be dose-dependently enhanced by SCF but not TNF-alpha. Results indicated that SCF activated ERK, and TNF-alpha activated the p38 MAPK and NF-kappaB pathway. Selective inhibitor of ERK, PD098059, and c-kit inhibitors, STI571 and PP1, suppressed the combined SCF and TNF-alpha-induced ICAM-1 expression. BAY117082 but not SB203580, which are the inhibitors of NF-kappaB and p38 MAPK, respectively, suppressed the TNF-alpha-induced ICAM-1 expression. Therefore, SCF and TNF-alpha acted through ERK and the NF-kappaB pathway to regulate the ICAM-1 expression and elicited the synergistic effect. In conclusion, our results provide insight for cross-talk between different signaling pathways that can help in understanding the fine control of adhesion molecule expression under the concerted effects of cytokines.     

E-selectin and intercellular adhesion molecule-1 are released by activated human endothelial cells in vitro.

Endothelial cells respond to several cytokines by a rapid increase in expression of the adhesion molecules E-selectin and intercellular adhesion molecule-1 (ICAM-1), followed by a gradual decline. The fate of these molecules, which was so far unknown, was studied. Specific sandwich ELISA for the detection of soluble (s)E-selectin and sICAM-1 were developed. In supernatant, centrifuged 3 hr at 100,000 g to remove microparticles, from human umbilical vein endothelial cells (HUVEC) activated with tumour necrosis factor (TNF), interleukin-1 (IL-1) or lipopolysaccharide (LPS), E-selectin and ICAM-1 molecules could be detected. Biochemical analysis revealed that sE-selectin migrated as a band of approximately 94,000 MW. The amount of soluble adhesion molecules released was directly correlated with cell surface expression. Maximal release of E-selectin was observed 6-12 hr after activation of HUVEC and decreased to below detection limit 24 hr after activation. After activation, release of ICAM-1 gradually increased with ICAM-1 cell surface expression, and reached a plateau after 24 hr, which was constant for 3 days. Since E-selectin and ICAM-1 are highly expressed at inflammatory sites, the resulting high concentrations of released E-selectin and ICAM-1 may affect interactions of leucocytes with endothelial cells. The physiological role, however, of the release of E-selectin and ICAM-1 remains to be elucidated.