三种化学小分子对补体旁路激活致内皮细胞黏附分子表达的干预及机制研究

目的研究白藜芦醇(Res)、PDTC和AG490 3种化学小分子对补体旁路激活致人微血管内皮细胞炎症反应相关黏附分子表达的干预作用和可能的作用机制。方法采用补体旁路激活产物作用于人微血管内皮细胞(HMEC)。TBA法检测细胞培养上清中丙二醛(MDA)的浓度,ELISA方法检测细胞培养上清中可溶性黏附分子ICAM-1、VCAM-1、E-selectin的表达,并采用多个浓度的Res、NF-κB信号通路抑制剂PDTC和JAK2信号通路抑制剂AG490预处理内皮细胞,研究3种抑制剂对细胞氧化水平和黏附分子表达的干预作用。利用Western blot检测补体旁路激活产物作用于内皮细胞对NF-κB p65磷酸化的影响及3种抑制剂的干预作用。结果 HMEC受补体旁路激活产物刺激后,导致细胞培养上清中MDA浓度升高,NF-κB p65磷酸化和黏附分子ICAM-1、VCAM-1和E-selectin的表达上调。Res可降低细胞培养上清中MDA的浓度。Res、PDTC和AG490能抑制NF-κB p65的磷酸化。Res与PDTC能抑制内皮细胞黏附分子ICAM-1和VCAM-1的表达,对E-selectin的表达有一定的抑制作用,而AG490能够明显抑制上述3种黏附分子的表达。结论 Res、PDTC和AG490对补体旁路激活产物致内皮细胞黏附分子表达上调有不同程度的抑制作用,其作用机制与NF-κB信号通路的活化有关,而JAK2可能是一个更重要的调控位点。     

川芎嗪对补体旁路激活致内皮细胞炎症反应的干预作用

目的研究川芎嗪(TMP)对补体旁路激活致人微血管内皮细胞(HMEC)炎症反应的干预作用及其可能的分子机制。方法以眼镜蛇毒因子(cobra venom factor,CVF)来激活正常人血清的补体旁路,用激活产物作用于HMEC,作用前加入不同浓度TMP预处理细胞,然后将细胞暴露在该激活产物中,采用ELISA方法检测细胞培养上清中可溶性黏附分子(ICAM-1、VCAM-1、E-selectin)和炎症介质(IL-6、TNF-α)的含量变化;双萤光素酶报告基因检测试剂盒测定NF-κB核内转录活性。结果 HMEC受补体旁路激活产物刺激后,引起黏附分子和炎症介质的表达上调,以及NF-κB核内转录活性的上调。不同浓度的TMP对上述炎症反应相关指标的上调均有干预作用,且表现出剂量依赖性。结论 TMP对补体旁路特异激活HMEC炎症反应有明显的干预作用,其机制可能与抑制NF-κB的核内转录活性有关。     

黄芩苷对脂多糖致内皮细胞炎症反应的保护作用及机制研究

目的研究黄芩苷对脂多糖(LPS)致人微血管内皮细胞(HMEC)炎症反应的保护作用及作用机制。方法采用LPS作用HMEC,建立炎症反应模型;以不同浓度的黄芩苷预处理细胞,然后将细胞暴露于LPS,ELISA检测炎症因子ICAM-1、IL-6和MCP-1的含量;荧光观察Ca^2+内流并采用流式细胞仪检测细胞内Ca^2+水平;免疫荧光法检测NF-κB p65入核情况;双荧光素酶报告基因方法检测NF-κB核内转录活性;Western blot检测NF-κB p65、p-NF-κB p65及TLR4的表达。结果HMEC暴露于LPS后,出现了明显的Ca^2+内流,NF-κB p65发生磷酸化,核内转录活性上调,ICAM-1、IL-6及MCP-1表达上调。不同浓度的黄芩苷均能抑制LPS刺激HMEC后产生的Ca^2+内流、NF-κB p65入核及核内转录活性上调,减少ICAM-1、IL-6、MCP-1的表达,下调NF-κB p65、p-NF-κB p65及TLR4的表达,且抑制作用呈现一定的量效关系。结论黄芩苷能抑制LPS诱导的HMEC炎症反应,其机制与抑制Ca^2+内流和NF-κB信号通路的活化,从而降低炎症反应的水平有关。     

补体旁路激活导致内皮细胞活化和损伤

目的研究补体替代途径的激活对血管内皮细胞活化和损伤的作用。方法采用眼镜蛇毒因子(CVF)与人血清孵育,特异激活补体替代途径。将孵育物作用于人微血管内皮细胞,采用ELISA检测内皮细胞P-selectin、E-selectin、ICAM-1、MCP-1和IL-8的表达,采用酶活性测定法检测乳酸脱氢酶(LDH)活性,化学发光法检测内皮细胞caspase-8活化信号,MTT法检测内皮细胞增殖活性,并检测内皮细胞释放NO的变化。结果补体旁路激活导致内皮细胞瞬时表达P-selectin,并进而使内皮细胞上调表达E-selectin、ICAM-1、MCP-1和IL-8。内皮细胞经补体激活物刺激后,LDH释放增加、凋亡信号caspase-8活化上调以及NO释放下调,同时,细胞增殖也受到抑制。结论补体旁路激活能诱导内皮细胞活化和损伤,介导血管内皮的生理结构与功能发生变化,从而可能导致相应的炎症和组织损伤。     

丹参酮ⅡA对TNF-α诱导的ECV304细胞NF-κB、IκB-α表达及粘附分子ICAM-1、VCAM-1mRNA表达的影响

目的探讨丹参酮ⅡA对血管内皮细胞株ECV304NF-κB、IκB-α及粘附分子ICAM-1、VCAM-1mRNA表达的影响,以阐明其抗动脉粥样硬化作用及机制。方法通过建立TNF-α诱导的ECV-304细胞损伤模型,以抗氧化剂吡咯烷二硫代氨基甲酸盐(PDTC)做为对照,间接细胞ELISA方法定量检测NF-κB、IκB-α的表达,RT-PCR方法检测各组细胞ICAM-1、VCAM-1mRNA的表达。结果TNF-α可增加ECV304细胞转录因子NF-κB的表达,同时降低其抑制因子IκB-α的表达,低浓度的丹参酮ⅡA对TNF-α引起的ECV304细胞NF-κB的表达升高无明显抑制作用,但可增加其IκB-α的表达;高浓度的丹参酮ⅡA可明显抑制NF-κB的表达,同时增加其抑制因子IκB-α的表达。同时丹参酮ⅡA抑制TNF-α诱导的ECV304细胞ICAM-1、VCAM-1mRNA表达。结论丹参酮ⅡA可通过抑制转录因子NF-κB的激活及其相关粘附分子ICAM-1、VCAM-1mRNA表达,这有利于抑制动脉粥样硬化过程中的炎症从而发挥抗动脉粥样硬化作用。     

法舒地尔对大鼠脑缺血再灌注损伤炎症反应的影响

目的：观察法舒地尔对大鼠脑缺血再灌注损伤炎症反应的影响,探讨其抗炎机制。方法：大脑中动脉线栓法（MCAO）制作大鼠局灶性脑缺血再灌注损伤模型,缺血1.5h再灌注24h。法舒地尔术前腹腔注射给药15mg/kg,术后12h再次给药。术后对大鼠神经功能进行评分,TTC染色观察脑梗死体积;用干湿重法测定脑含水量;分光光度法测定髓过氧化物酶（MPO）活性;伊文思兰法（EB）测定血脑屏障的损伤程度;免疫组化检测大鼠脑缺血区细胞间黏附分子-1（ICAM-1）、血管细胞黏附分子-1（VCAM-1）、NF-κB p65的表达;ELISA法检测IL-8的含量;Western blot法检测单核细胞趋化蛋白-1（MCP-1）和核抽提物中NF-κBp65蛋白的表达;RT-PCR检测NF-κB p65mRNA的表达。结果：法舒地尔能明显改善脑缺血再灌注损伤大鼠神经缺陷症状,缩小脑梗死体积,明显降低缺血侧脑组织的含水量、EB含量及MPO活性;显著抑制ICAM-1、VCAM-1、IL-8和MCP-1蛋白的表达;降低NF-κB p65mRNA和蛋白的表达;减少脑组织核抽提物中NF-κB p65的蛋白量（P〈0.05vsMCAO组）。结论：法舒地尔通过抑制NF-κBp65的活化,进而抑制黏附分子及趋化因子的表达,减轻脑缺血再灌注损伤的炎症反应。     

地塞米松及N-乙酰半胱氨酸抑制A549细胞IL-8及ICAM-1表达的机制研究

目的探讨DXM及N-乙酰半胱氨酸(NAC)抑制A549细胞IL-8、ICAM-1表达的机制。方法 ELISA及流式细胞术分别检测IL-8及ICAM-1表达;蛋白印迹法检测GR、HDAC、AP-1、NF-κB表达,分光光度法检测HDAC活性。结果 DXM、NAC均能抑制TNF-α诱导的IL-8、ICAM-1表达增高。DXM能抑制TNF-α、LPS诱导的AP-1及NF-κB转录活化、HDAC表达及活性降低;NAC只抑制NF-κB转录活化,对AP-1转录活化、HDAC表达及活性降低无影响。结论 DXM、NAC均具有抗炎作用。DXM通过增加HDAC蛋白表达及活性,抑制AP-1、NF-κB转录活化发挥抗炎作用,而NAC对HDAC蛋白表达及活性无影响,提示NAC可能不是通过乙酰化信号机制发挥抗炎作用。     

布地奈德对哮喘大鼠IKK/NF-κB信号通道影响的实验研究

目的:观察布地奈德混悬液(Bud,商品名:普米克令舒)对哮喘大鼠肺组织IκB激酶(IKKβ)mRNA表达及核转录因子(NF-κB)活化的影响.方法:复制哮喘大鼠模型,分为正常组、哮喘组和布地奈德混悬液雾化组,用原位杂交法检测肺组织IKKβ mRNA表达,免疫组化检测肺组织NF-κBp65蛋白活性,双抗体夹心酶联免疫法(ELISA)检测血清及支气管肺泡灌洗液(BALF)中IL-5 的浓度.结果:哮喘组肺组织IKKβ mRNA(0.203±0.038)及NF-κBp65(0.256±0.063)表达量均显著高于正常组(分别为 0.015±0.006,0.034±0.008,P＜0.01).布地奈德混悬液雾化组肺组织IKKβ mRNA (0.101±0.010)和NF-κBp65(0.062±0.014)表达均显著低于哮喘组(P均<0.01).结论:哮喘组肺组织IKKβ mRNA、NF-κBp65表达显著增强,Bud雾化吸入能有效抑制哮喘大鼠肺组织IKKβ mRNA的表达及NF-κBp65的活性,证明Bud能有效抑制IKK/NF-κB信号通道的活性.     

若干天然活性分子对微血管内皮炎症反应的干预作用

目的微血管内皮炎症反应与一系列重要病征的发病机制高度关联,本研究以微血管内皮炎症反应为靶标挖掘和评价贵州民族药若干重要活性分子的药理功效。方法分别建立补体旁路激活诱导的微血管内皮细胞炎症反应模型和小鼠急性肺损伤模型,研究绿原酸、淫羊藿苷、白藜芦醇、黄芩苷、川芎嗪等活性分子对炎症反应的干预作用。结果基于细胞模型的研究表明,绿原酸、淫羊藿苷、白藜芦醇、黄芩苷、川芎嗪等活性分子能抑制NF-κB信号通路的活化和核内转录活性的上调,下调黏附分子和炎症介质的表达;小鼠模型的结果表明,上述活性分子可以降低支气管肺泡灌洗液中的蛋白含量、炎性细胞数目、IL-6和TNF-α以及ICAM-1的含量以及肺组织匀浆的髓过氧化物酶活性,并可显著降低血清中IL-6,TNF-α和ICAM-1的水平,肺组织中的炎性细胞浸润明显减轻,NF-κB P65的磷酸化水平也显著降低。结论绿原酸、淫羊藿苷、白藜芦醇、黄芩苷、川芎嗪等活性分子可明显抑制补体旁路激活导致的微血管内皮炎症反应,其机制与抑制炎症相关信号通路的活化从而有效干预炎症反应有关。     

阿托伐他汀对兔动脉粥样硬化中NF-κB/IκB和炎症因子表达的影响

目的探讨高脂饮食诱发兔动脉粥样硬化中核因子-κB(NF-κB)的活化与其抑制因子IκB的表达,以及阿托伐他汀对NF-κB/IκB信号途径、ICAM-1和P选择素的影响。方法24只新西兰♂家兔随机分为正常对照组、高胆固醇组和阿托伐他汀组,应用W estern b lot方法检测动脉中胞核NF-κB p65亚基和胞浆IκBα表达变化;免疫放射法检测血清P选择素水平,免疫组织化学检测血管壁ICAM-1的表达。结果高胆固醇组与对照组比较胞核NF-κB p65和血管壁ICAM-1表达明显增强、血P选择素明显升高(P<0.05),胞浆中IκBα表达明显减弱(P<0.05);阿托伐他汀组与高胆固醇组比较NF-κB p65和血管壁ICAM-1明显表达较弱、血P选择素明显减少(P<0.05),胞浆IκBα的表达增强(P<0.05)。结论NF-κB/IκB信号途径在动脉粥样硬化中起重要作用,阿托伐他汀可以减少P选择素、ICAM-1的表达。     

SH-5, an AKT inhibitor potentiates apoptosis and inhibits invasion through the suppression of anti-apoptotic, proliferative and metastatic gene products regulated by IkappaBalpha kinase activation

Because the phosphatidylinositol-3-kinase-AKT pathway is emerging as an important regulator of tumor cell survival, inhibitors of this pathway have enormous potential in cancer treatment. A specific inhibitor of AKT, [d-3-deoxy-2-O-methyl-myo-inositol-1-[(R)-2-methoxy-3-(octadecyloxy)propyl hydrogen phosphate]] (SH-5) has been recently synthesized, but little is known about its effects on cytokine signaling. We found that SH-5 potentiated the apoptosis induced by tumor necrosis factor (TNF), as indicated by intracellular esterase staining, annexin V staining, and caspase-3 activation. This effect of SH-5 correlated with downregulation of various gene products that mediate cell survival, proliferation, metastasis, and invasion, all known to be regulated by NF-κB. SH-5 also blocked NF-κB activation induced by TNF-α, lipopolysaccharide, phorbol ester, and cigarette smoke but not that activated by hydrogen peroxide and RANK ligand, indicating differential requirement of AKT. Inhibition of NF-κB correlated with abrogation of phosphorylation and degradation of IκBα through the inhibition of activation of IκBα kinase (IKK). This led to suppression of the phosphorylation and translocation of p65 and also of NF-κB reporter activity induced by TNFR1, TRADD, TRAF2, NIK, and IKKβ but not that induced by p65 transfection. Thus, our results clearly demonstrate that inhibition of AKT leads to potentiation of apoptosis through modulation of NF-κB signaling.     

ZLJ-6, a novel COX/5-LOX inhibitor, attenuates TNF-α-induced endothelial E-selectin, ICAM-1 and VCAM-1 expression and monocyte-endothelial interactions via a COX/5-LOX-independent mechanism

Nonsteroidal anti-inflammatory drugs (NSAIDs) are previously found to possess prostaglandin and leukotriene-independent anti-inflammatory effect. The aim of the present study was to investigate the prostaglandin and leukotriene-independent anti-inflammatory effect of an imidazolone COX/5-LOX inhibitor ZLJ-6 and the underlying mechanism. Pretreatment human umbilical vein endothelial cells (HUVECs) with ZLJ-6 (3, 10 and 30μM) concentration-dependently decreased TNF-α-induced monocyte-endothelial interactions in both static and dynamic conditions whereas no effect was found after pretreatment with the COX-2 inhibitor celecoxib (30μM), 5-LOX inhibitor zileuton (30μM) and the combination of them. ZLJ-6 also attenuated expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cytoadhesion molecule-1 (VCAM-1) on TNF-α-induced HUVECs. A further analysis indicated that ZLJ-6 attenuated TNF-α-induced nuclear translocation of NF-κB, IκB phosphorylation, IκB kinase β (IKKβ) activity, and subsequent NF-κB-DNA complex formation, suggesting that NF-κB pathway was involved in TNF-α-induced inflammation. However, ZLJ-6 did not affect TNF-α-induced extracellular signal-regulated kinases (ERK1/2), c-Jun N-terminal kinases (JNK) and p38 phosphorylation. Taken together, our results indicated that ZLJ-6 potently inhibited TNF-α-induced monocyte-endothelial interactions and adhesion molecule (E-selectin, ICAM-1 and VCAM-1) expression and these effects were mediated by NF-κB signaling pathway rather than its primary pharmacological target COX-2 or 5-LOX.     

Sulforaphane suppresses vascular adhesion molecule-1 expression in TNF-α-stimulated mouse vascular smooth muscle cells: involvement of the MAPK, NF-κB and AP-1 signaling pathways

Atherosclerosis is a long-term inflammatory disease of the arterial wall. Increased expression of the cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) is associated with increased proliferation of vascular smooth muscle cells (VSMCs), leading to increased neointima or atherosclerotic lesion formation. Therefore, the functional inhibition of adhesion molecules could be a critical therapeutic target of inflammatory disease. In the present study, we investigate the effect of sulforaphane on the expression of VCAM-1 induced by TNF-α in cultured mouse vascular smooth muscle cell lines. Pretreatment of VSMCs for 2h with sulforaphane (1-5μg/ml) dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and protein expression of VCAM-1. Sulforaphane also suppressed TNF-α-induced production of intracellular reactive oxygen species (ROS) and activation of p38, ERK and JNK. Furthermore, sulforaphane inhibited NK-κB and AP-1 activation induced by TNF-α. Sulforaphane inhibited TNF-α-induced ΙκΒ kinase activation, subsequent degradation of ΙκΒα and nuclear translocation of p65 NF-κB and decreased c-Jun and c-Fos protein level. This study suggests that sulforaphane inhibits the adhesive capacity of VSMC and downregulates the TNF-α-mediated induction of VCAM-1 in VSMC by inhibiting the MAPK, NF-κB and AP-1 signaling pathways and intracellular ROS production. Thus, sulforaphane may have beneficial effects to suppress inflammation within the atherosclerotic lesion.     

Inhibition of TNF-α-induced adhesion molecule expression by diosgenin in mouse vascular smooth muscle cells via downregulation of the MAPK, Akt and NF-κB signaling pathways

Atherosclerosis is a chronic inflammatory disease and the expression of adhesion molecules on vascular smooth muscle cells (VSMCs) contributes to the progress of the disease. Diosgenin, a precursor of steroid hormones, has been shown to have a variety of biological activities including anti-inflammatory activity; however, its molecular mechanisms are poorly understood. This study examined the effect of diosgenin on the expression of adhesion molecules induced by TNF-α in cultured mouse VSMC cell line, MOVAS-1. Preincubation of VSMCs for 2h with diosgenin (0.1-10 μM) dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Diosgenin abrogated TNF-α induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38, ERK, JNK and Akt. Diosgenin was also shown to inhibit NK-κB activation induced by TNF-α. Furthermore, diosgenin inhibited TNF-α-induced IκB kinase activation, subsequent degradation of IκBα, and nuclear translocation of NF-κB. Our results indicate that diosgenin inhibits the adhesive capacity of VSMC and the TNF-α-mediated induction of ICAM-1 and VCAM-1 in VSMC by inhibiting the MAPK/Akt/NF-κB signaling pathway and ROS production, which may explain the ability of diosgenin to suppress inflammation within the atherosclerotic lesion and modulate immune response.     

Tetrachlorobenzoquinone exhibits neurotoxicity by inducing inflammatory responses through ROS-mediated IKK/IκB/NF-κB signaling

Tetrachlorobenzoquinone (TCBQ) is a joint metabolite of persistent organic pollutants (POPs), hexachlorobenzene (HCB) and pentachlorophenol (PCP). Previous studies have been reported that TCBQ contributes to acute hepatic damage due to its pro-oxidative nature. In the current study, TCBQ showed the highest capacity on the cytotoxicity, ROS formation and inflammatory cytokines release among four compounds, i.e., HCB, PCP, tetrachlorohydroquinone (TCHQ, reduced form of TCBQ) and TCBQ, in PC 12 cells. Further mechanistic study illustrated TCBQ activates nuclear factor-kappa B (NF-κB) signaling. The activation of NF-κB was identified by measuring the protein expressions of inhibitor of nuclear factor kappa-B kinase (IKK) α/β, p-IKKα/β, an inhibitor of NF-κB (IκB) α, p-IκBα, NF-κB (p65) and p-p65. The translocation of NF-κB was assessed by Western blotting of p65 in nuclear/cytosolic fractions, electrophoretic mobility shift assay (EMSA) and luciferase reporter gene assay. In addition, TCBQ significantly induced protein and mRNA expressions of inflammatory cytokines and mediators, such as interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and the production of nitric oxide (NO) and prostaglandin E2 (PGE2). Pyrrolidine dithiocarbamate (PDTC), a specific NF-κB inhibitor inhibited these effects efficiently, further suggested TCBQ-induced inflammatory responses involve NF-κB signaling. Moreover, antioxidants, i.e., N-acetyl-l-cysteine (NAC), Vitamin E and curcumin, ameliorated TCBQ-induced ROS generation as well as the activation of NF-κB, which implied that ROS serve as the upstream molecule of NF-κB signaling. In summary, TCBQ exhibits a neurotoxic effect by inducing oxidative stress-mediated inflammatory responses via the activation of IKK/IκB/NF-κB pathway in PC12 cells.     

Inhibition of TNF-α-induced adhesion molecule expression by diosgenin in mouse vascular smooth muscle cells via downregulation of the MAPK,Akt and NF-κB signaling pathways

Atherosclerosis is a chronic inflammatory disease and the expression of adhesion molecules on vascular smooth muscle cells (VSMCs) contributes to the progress of the disease. Diosgenin, a precursor of steroid hormones, has been shown to have a variety of biological activities including anti-inflammatory activity; however, its molecular mechanisms are poorly understood. This study examined the effect of diosgenin on the expression of adhesion molecules induced by TNF-α in cultured mouse VSMC cell line, MOVAS-1. Preincubation of VSMCs for 2 h with diosgenin (0.1–10 μM) dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Diosgenin abrogated TNF-α induced production of intracellular reactive oxygen species (ROS) and phosphorylation of p38, ERK, JNK and Akt. Diosgenin was also shown to inhibit NK-κB activation induced by TNF-α. Furthermore, diosgenin inhibited TNF-α-induced IκB kinase activation, subsequent degradation of IκBα, and nuclear translocation of NF-κB. Our results indicate that diosgenin inhibits the adhesive capacity of VSMC and the TNF-α-mediated induction of ICAM-1 and VCAM-1 in VSMC by inhibiting the MAPK/Akt/NF-κB signaling pathway and ROS production, which may explain the ability of diosgenin to suppress inflammation within the atherosclerotic lesion and modulate immune response.     

Suppression of adhesion molecule expression by phenanthrene-containing extract of bulbils of Chinese Yam in vascular smooth muscle cells through inhibition of MAPK,Akt and NF-κB

Atherosclerosis is a chronic inflammatory disease associated with increased expression of adhesion molecules in vascular smooth muscle cells (VSMCs). The objective of this study was to examine the in vitro effects of extract from aerial Bulbil of Dioscorea batatas Decne (Db-Ex) on the ability to suppress the expression of adhesion molecules induced by TNF-α. We also identified bioactive components from a methanol extract. VSMCs pre-exposed to Db-Ex (10–100 μg/ml) were stimulated with TNF-α (10 ng/ml). Preincubation of VSMCs for 2 h with Db-Ex dose-dependently inhibited TNF-α-induced adhesion of THP-1 monocytic cells and mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Db-Ex treatment decreased ROS production and the amount of phosphorylated form of p38, ERK, JNK and Akt in TNF-α-stimulated cells, suggesting that Db-Ex inhibits adhesion molecule expression possibly through MAPK and Akt regulation. Db-Ex also suppressed TNF-α-activation NK-κB. This effect was mediated through degradation of IκBα and nuclear translocation of the p65 subunit of NF-κB. These results suggest that Db-Ex inhibits monocyte adhesion and the TNF-α-mediated induction of adhesion molecules in VSMC by downregulating the MAPK/Akt/NF-κB signaling pathway, which may explain the ability of Db-Ex to suppress inflammation within the atherosclerotic lesion.     

Motorcycle exhaust particles up-regulate expression of vascular adhesion molecule-1 and intercellular adhesion molecule-1 in human umbilical vein endothelial cells

Epidemiological studies have shown that there is a strong correlation between atherosclerosis and ambient air pollution. In this study, we found that motorcycle exhaust particles (MEP) induced adhesion between cells of the human monocytic leukemia cell line (THP-1) and human umbilical vein endothelial cells (HUVECs) in a time-and dose-dependent manner. In addition, MEP treatment induced both mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in HUVECs. The IκB degradation and p65 nuclear translocation was found in MEP-treated HUVECs, suggested the involvement of nuclear factor-κB (NF-κB). MEP-induced VCAM-1 and ICAM-1 protein expression was inhibited by NF-κB inhibitor BAY 11-7085. Oxidative stress was also involved in the signaling of VCAM-1 and ICAM-1 expression. MEP treatment caused hydrogen peroxide and superoxide formation. Pretreatment with α-tocopherol could inhibit MEP-induced reactive oxygen intermediates generation and suppressed MEP-induced IκB degradation and adhesion molecules expression. Furthermore, the carbon black (CB) nanoparticles with different diameters could induce VCAM-1 and ICAM-1 protein expression; however, polycyclic aromatic hydrocarbons (PAHs) only increased the expression of ICAM-1 but not that of VCAM-1 in HUVECs. In this study, we found that MEPs could induce ICAM-1 and VCAM-1 expression through oxidative stress and NF-κB activation in HUVECs.