LPS和TNF-α对血管内皮细胞SSeCKS的表达影响

目的：研究细菌脂多糖（LPS）、肿瘤坏死因子（TNF-α）对牛肺动脉内皮细胞（BPAEC）Src抑制的蛋白激酶C底物（Src-suppressed C Kinase Substrate，SSeCKS）表达的影响和对细胞骨架结构的影响，探讨SSeCKS参与细胞骨架结构改变的可能机制。方法：应用LPS、TNF-α刺激体外培养的BPAEC，应用原位杂交、免疫印迹方法检测不同刺激条件下BPAEC中SSeCKS mRNA和蛋白的表达情况；免疫细胞荧光法观察LPS、TNF-α对内皮细胞中SSeCKS与纤维状肌动蛋白（F-actin）定位和结构的影响。结果：静息状态的BPAEC表达极少量的SSeCKS；经LPS刺激后，SSeCKS表达没有明显变化；而TNF-α以浓度和时间依赖的方式诱导内皮细胞SSeCKS表达增加；LPS和TNF-α刺激后，F-actin发生重构，且SSeCKS向核周、细胞膜纤维、板状伪足聚集；蛋白激酶C（PKC）抑制剂Ro-31．8220抑制LPS和TNF-α对内皮细胞F-actin和SSeCKS细胞内定位改变的影响。结论：TNF-α能够诱导内皮细胞SSeCKS表达增加，PKC参与LPS、TNF-α诱导内皮细胞F-actin的重构和SSeCKS重新分布。提示SSeCKS可能与LPS和TNF-α诱导内皮细胞F-actin的重构有关。     

037 TNF-α导致细胞骨架重排和当归的逆转作用

目的: 探讨TNF-α导致细胞骨架重排和当归的逆转作用. 方法: 常规培养人脐静脉内皮细胞, 分成下列各组: ①对照组: 常规培养; ②当归组: 培养液中加入当归注射液20 mg/ml; ③ TNF-α组: 培养液中加入TNF-α 100 U/ml; ④ TNF-α+当归组: 培养液中同时加入TNF-α 100 U/ml和当归20 mg/ml. 4 h后用Phalloidine rhodamine标记骨架蛋白F-actin, 用Olympus LX70荧光显微镜(CellScan, Scanalytics-Bionis)检测细胞骨架分布. 结果: 荧光显微镜下, 在内皮细胞的每一个横切面, 对照组细胞骨架均排列在细胞周围, Factin分布均匀, 粗细匀称; 当归注射液不影响正常内皮细胞的细胞骨架排列, 但可见部分actin肌丝增粗; TNF-α作用后整个细胞腔面细胞骨架排列紊乱, 在细胞中部横切面, 增粗的actin肌丝横跨整个细胞; 将当归注射液与TNF-α共同作用于内皮细胞, 可见细胞骨架排列在细胞周围, 但与正常细胞状态略有不同. 结论: TNF-α可以导致细胞骨架重排, 这种重排与剪切力导致的重排相似. 当归能逆转TNF-α导致的细胞骨架重排, 使F-actin排列在细胞周围. 这种作用的意义及信号转号途径目前还不完全清楚. 本室的其他实际显示, 当归注射液可以降低氧化低密度脂蛋白导致的ICAM-1表达增加, 逆转TNF-α导致的ICAM-1重排. 当归抗动脉粥样硬化可能与这些作用有关.     

1-磷酸鞘氨醇对血小板活化因子所致大鼠肠系膜微血管通透性增高的影响

目的:探讨1-磷酸鞘氨醇(S1P)对血小板活化因子(PAF)引起的大鼠肠系膜微血管通透性增高的影响。方法:本研究拟采用大鼠在体肠系膜微血管灌注的方法,通过测定微静脉的静水传导性(Lp),观察S1P对外源性PAF引起的微血管通透性增高的影响;并利用激光共聚焦显微镜技术,观察S1P对PAF引起的微血管荧光强度变化以及血管内皮细胞钙粘蛋白(VE-cadherin)变化的影响。结果:给予10nmol/LPAF作用后,大鼠肠系膜微血管Lp值明显增高,而经1μmol/L S1P预处理后,再给予PAF并未引起Lp的明显变化;PAF作用微血管后可见微血管内皮细胞间隙打开,微血管荧光强度明显增加,大量红色荧光微球(FMs)分布于内皮细胞间隙之中,S1P预处理后并未见内皮细胞间隙打开及FMs的明显积聚,微血管荧光强度与正常对照值比较无显著差异。结论:PAF可增加微血管的通透性,改变内皮细胞VE-cadherin正常结构,导致粘附连接断裂,细胞间隙形成,血管通透性增加可能与此结构变化有关。S1P能改善PAF引起的血管通透性增高,其作用与加强内皮细胞间粘附连接,抑制细胞间隙打开有关。     

霉酚酸酯对血管内皮细胞与淋巴细胞粘附及其表达CD40L的影响

目的：观察霉酚酸酯（MMF）对细胞因子刺激下人脐静脉内皮细胞（mWEC）CD40L的影响。方法：正常分娩人脐带经胶原酶消化后，分离出内皮细胞，培养至3～5代，用于细胞粘附和CIMOL表达试验。以TNF-α和／或霉酚酸（船A）处理HUVEC 20小时后，用虎红法研究对淋巴细胞与内皮细胞粘附作用。以TNF-α、rIFN-γ、LPS分别和MPA同时作用HUVEC 24小时。加不同浓度的MPA与LPS诱导HUVEC 24小时，用Cell-ELISA检测CIMOL的表达。结果：（1）MMF能抑制静息及TNF-α激活的内皮细胞与淋巴细胞间的粘附作用。（2）三种细胞因子均可明显诱导内皮细胞表达CD40L分子。（3）MMF不能抑制静息状态下内皮细胞CD40L的表达，但抑制TNF-α、rIFN-γ和LPS诱导CIMOL的表达作用，且MMF抑制LPS诱导的内皮细胞CD40L表达呈剂量依赖效应。结论：MMF通过抑制内皮细胞表达CIMOL而影响淋巴细胞与内皮细胞的相互作用，这可能是MMF抗排斥反应机制之一。     

TNF-α激活RhoA/ROCK信号通路增加单核细胞增生性李斯特菌感染内皮细胞的通透性

目的探讨大鼠肉瘤同源基因A/Rho相关螺旋卷曲蛋白激酶(RhoA/ROCK)信号通路在肿瘤坏死因子α(TNF-α)促进单核细胞增生性李斯特(Lm)感染致内皮细胞通透性升高的调控作用。方法培养人脐静脉内皮细胞(HUVEC)分为未感染细胞对照组、 TNF-α处理组(100 ng/mL TNF-α处理2 h)、 Lm感染组(以MOI=10的Lm感染2 h,加入庆大霉素杀菌0.5 h)、 TNF-α处理的Lm感染组(Lm感染组细胞加入100 ng/mL TNF-α处理2 h)、 Y-27632联合TNF-α处理的Lm感染组(细胞用50μmol/L ROCK抑制剂Y-27632处理30 min,再如上进行Lm感染和TNF-α刺激)。Western blot法检测HUVEC的RhoA、闭锁小带蛋白1(ZO-1)、闭合蛋白(occludin)、 ROCK蛋白水平,检测辣根过氧化物酶(HRP)渗漏量分析HUVEC通透性变化,用异硫氰酸荧光素(FITC)标记的鬼笔环肽染色检测纤维型肌动蛋白(F-actin)细胞骨架的改变。结果 TNF-α可降低Lm感染的内皮细胞紧密连接蛋白ZO-1、 occludin的表达,促进其通透性升高、细胞骨架重排,并上调RhoA和ROCK的表达。ROCK抑制剂Y-27632可明显抑制TNF-α所致的HUVEC细胞骨架重排及通透性增高的作用。结论 TNF-α促进感染Lm的血管内皮细胞通透性增高可能通过RhoA/Rock信号通路调控。     

犀角地黄汤合银翘散通过PKC-SSeCKS通路抑制TNF-α诱导的肺微血管内皮细胞通透性增加

目的:观察犀角地黄汤合银翘散(XDY)对TNF-α诱导的大鼠肺微血管内皮细胞(PMVEC)通透性的影响及其与PKC-SSeCKS信号通路的关系,以探究该方治疗病毒性肺炎的作用环节和分子机制。方法:原代培养大鼠PMVEC,在Transwell小室上用电导法于不同时点监测TNF-α诱导的PMVEC跨内皮细胞单层电阻(TER)测定其通透性。不同的干预因素作用24 h后,检测PMVEC的TER、PKC活性、SSeCKS mRNA水平和磷酸化SSeCKS蛋白水平,激光共聚焦显微镜观察PMVEC中SSeCKS的定位和F-actin的结构变化。结果:TNF-α作用24 h后PMVEC通透性达高峰;与对照组比较,TNF-α组TER降低,PKC活性增强;与TNF-α组比较,TNF-α加PKC抑制剂组和TNF-α加XDY含药血清组PKC活性降低,而TER升高且与对照组无差别。与对照组比较,TNF-α组SSeCKS的mRNA和蛋白表达升高;与TNF-α组比较,TNF-α加XDY含药血清组SSeCKS的mRNA水平和磷酸化SSeCKS蛋白水平降低。对照组PMVEC中F-actin主要分布在细胞周边和核周,形成致密周围束,SSeCKS均匀散在分布于细胞中;TNF-α组细胞周边的F-actin致密束基本消失,SSeCKS集中分布于核周;TNF-α加含XDY含药血清组F-actin结构及SSeCKS的分布趋于正常。结论:犀角地黄汤合银翘散可以抑制TNF-α诱导的PMVEC PKC信号通路的激活,降低PKC结合底物SSeCKS的表达,最终影响肌动蛋白的变构、阻止内皮细胞变形而降低PMVEC的通透性。     

细胞因子对心脏微血管内皮细胞与淋巴细胞粘附的影响

目的：观察细胞因子对心脏微血管内皮细胞表面细胞间粘附分子－１（ｉｎｔｅｒｃｅｌｕｌａｒａｄｈｅｓｉｏｎｍｏｌｅｃｕｌｅ－１，ＩＣＡＭ－１）的表达的调控，及对内皮细胞与激活淋巴细胞粘附的影响。方法：体外培养大鼠心脏微血管内皮细胞，以肿瘤坏死因子（ｔｕｍｏｒｎｅｃｒｏｓｉｓｆａｃｔｏｒ－α，ＴＮＦ－α）、白细胞介素－６（ｉｎｔｅｒｌｅｕｋｉｎ６，ＩＬ－６）和白细胞介素－１（ｉｎｔｅｒｌｅｕｋｉｎ１β，ＩＬ－１β）诱导。采用免疫组织化学染色法观察内皮细胞表面ＩＣＡＭ－１表达；采用粘附试验和抗ＩＣＡＭ－１或抗ＬＦＡ－１单克隆抗体阻断抑制试验。结果：ＴＮＦ－α、ＩＬ－６和ＩＬ－１β诱导内皮细胞１８～２４ｈ，均可使内皮细胞与淋巴细胞的粘附率显著增加，ＴＮＦ－α和ＩＬ－１β的诱导还可使内皮细胞表面ＩＣＡＭ－１分子表达明显增强，表现为ＩＣＡＭ－１表达阳性细胞数增多，着色加深。用１０～２０ｍｇ／Ｌ抗ＩＣＡＭ－１或抗ＬＦＡ－１单克隆抗体均可部分抑制内皮细胞与淋巴细胞的粘附。结论：ＴＮＦ－α和ＩＬ－１β可以有效地激活心脏微血管内皮细胞，通过诱导内皮细胞ＩＣＡＭ－１表达增多，促进内皮细胞与淋巴细胞的粘附     

PKC在TNF-α诱导内皮细胞β-1,4-半乳糖基转移酶-Ⅰ表达中的作用

目的:研究蛋白激酶C(PKC)对肿瘤坏死因子-α(TNF-α)诱导内皮细胞β-1,4-半乳糖基转移酶-I(β-1,4-GalT-Ⅰ)表达的调节作用,以及对内皮细胞骨架结构改变及其黏附能力的影响。方法:分别用PKC激动剂或几种不同类型的PKC抑制剂预处理人脐静脉内皮细胞(HUVECs),再用TNF-α刺激HUVECs,应用RT-PCR、Western blot方法检测β-1,4-GalT-Ⅰ表达变化,应用细胞荧光染色观察β-1,4-GalT-Ⅰ催化的糖链的表达变化及细胞骨架结构的改变,通过内皮-单核细胞黏附试验观察HUVECs黏附能力的改变。结果:几种不同类型的PKC抑制剂均能不同程度的抑制TNF-α刺激HU-VECs引起的β-1,4-GalT-Ⅰ表达的上调,PKC激动剂能够使上调的β-1,4-GalT-Ⅰ的表达进一步增加;在HUVECs中β-1,4-GalT-Ⅰ与细胞骨架有共同定位,PKC抑制剂显著抑制TNF-α诱导的内皮细胞骨架蛋白的重构和β-1,4-GalT-Ⅰ细胞内的再分布;PKC抑制剂显著抑制TNF-α诱导的内皮-单核细胞黏附能力的上调。结论:PKC可能参与调节TNF-α诱导的HUVECsβ-1,4-GalT-Ⅰ的表达,并且可能多种类型的PKC参与了这一调节过程;PKC可能通过对β-1,4-GalT-Ⅰ的调节进而影响炎症过程中内皮细胞骨架蛋白的重构及内皮细胞与单核细胞的黏附能力。     

剪切力对脑微血管内皮细胞形态学的影响

我们利用自行研制的细胞流动小室对大鼠脑微血管内皮细胞在剪切力作用下的形态学改变进行了初步研究。结果提示脑微血管内皮细胞对剪切力的耐受性要低于大血管内皮细胞 ,在同样的剪切力和作用时间下 ,大血管内皮细胞没有明显变化。微血管内皮细胞已有明显的形态学变化 ,细胞间隙明显增大、细胞皱缩、脱落 ,这些改变的直接后果是通透性的增加。我们的工作为进一步开展剪切力对微血管内皮细胞功能、代谢等方面的影响提供了实验数据。     

活性氧及抗癌药物对内皮细胞通透性、细胞骨架及癌细胞粘附量的影响

为研究癌─内皮细胞的相互关系，建立了一种研究血管内皮通透性变化的体外模型，观察了氧自由基及抗癌药诱发的细胞毒作用对内皮细胞通透性、细胞骨架及癌细胞粘附量的影响。结果表明，细胞毒作用可引起内皮细胞通透性增加，在形态学上表现为内皮细胞收缩、内皮间隙增大，骨架纤维变短变粗。扫描电镜下可见粘附细胞增多。     

巨噬细胞炎症因子1α对人脑微血管内皮细胞通透性的影响

目的研究巨噬细胞炎症因子1α(MIP-1α)是否具有开通血脑屏障的作用。方法以重组人MIP-1α直接作用于人脑微血管内皮细胞(HBMEC),免疫荧光方法检测紧密连接蛋白ZO-1的分布变化、跨内皮细胞电阻、HRP穿过HBMEC单层的改变、HBMEC细胞CC趋化因子受体5(CCR5)的表达,以及MIP-1α中和抗体和分泌MIP-1α的模式细胞(6T-CEM)与HBMEC单层共同温育时ZO-1的分布变化。结果MIP-1α作用下,HBMEC单层紧密连接结构被破坏,通透性增加,引起HBMEC细胞CCR5受体的表达,MIP-1α中和抗体阻断6T-CEM细胞对HBMEC单层ZO-1分布的改变。结论MIP-1α可能通过CCR5改变HBMEC单层通透性促进T淋巴细胞穿过血脑屏障。     

TNF-α在热疗降低胶质瘤侵袭性过程中的作用

 目的 探讨肿瘤坏死因子-α(TNF-α)在热疗抑制肿瘤侵袭性过程中的作用。方法 热处理大鼠恶性胶质瘤细胞(C6细胞)和胶质瘤大鼠后,放射免疫法监测培养液和脑胶质瘤组织内TNF-α的浓度;免疫组化法检测经热疗/ TNF-α/生理盐水处理过的胶质瘤组织内增殖细胞核抗原(PCNA)蛋白的表达。利用Transwell构建肿瘤侵袭模型,通过结晶紫染色法检测肿瘤侵袭性。电镜观察C6恶性胶质瘤大鼠肿瘤血管内皮细胞的凋亡。结果 热疗可增加C6细胞培养液和胶质瘤大鼠肿瘤组织内的TNF-α含量及降低胶质瘤侵袭性,均于热疗后120min时达高峰(P＜0.01)。热疗与TNF-α单独作用于胶质瘤大鼠后,均可引起胶质瘤大鼠肿瘤血管内皮细胞的凋亡。且TNF-α引起内皮细胞的凋亡水平与热处理后C6细胞培养液中TNF-α含量一致。结论 热疗可能是通过增加TNF-α引起肿瘤血管内皮细胞凋亡而抑制了肿瘤侵袭性。     

Dengue hemorrhagic fever-associated immunomediators induced via maturation of dengue virus nonstructural 4B protein in monocytes modulate endothelial cell adhesion molecules and human microvascular endothelial cells permeability

We previously demonstrated that dengue virus (DENV) nonstructural 4B protein (NS4B) induced dengue hemorrhagic fever (DHF)-associated immunomediators in THP-1 monocytes. Moreover, cleavage of NS4AB polyprotein by the NS2B3 protease, significantly increased immunomediator production to levels found after DENV infection. In this report using primary human microvascular endothelial cells (HMVEC) transwell permeability model and HMVEC monolayer, we demonstrate that the immunomediators secreted in the supernatants of DENV-infected monocytes increase HMVEC permeability and expression of ICAM-1, VCAM-1 and E-selectin. Moreover, maturation of NS4B via cleavage of 2KNS4B is sufficient to induce immunomediators that cause HMVEC phenotypic changes, which appear to be synergistically induced by TNFα and IL-8. These data suggest that therapies targeting the maturation steps of NS4B, particularly 2KNS4B processing, may reduce overall DHF-associated immunomediator levels, thereby reducing DHF-associated morbidity and mortality. Alternatively, TNFα inhibitors may be a valid intervention strategy during the later stages of infection to prevent DHF progression.     

Two types of TNFα in meagre (Argyrosomus regius): Discovery,distribution and expression modulation

TNFα is a key cytokine involved in systemic inflammation and regulation of immune cells and is important during development. In the present study, 2 isoforms of TNFα were discovered in meagre, an emerging species in aquaculture. Phylogenetic analysis suggests these isoforms represent the type I and type II TNFα classes previously described in other teleost species. This study is the first to compare how these 2 types of TNFα behave in meagre and aims to provide insights into their expression in teleost fish by interrogating expression in whole tissues and isolated cell populations in four immunologically important sites (gills, intestine, head kidney and spleen) following PAMP stimulation, as well as monitoring gene expression during meagre development. Differential expression was seen in head kidney and gills, where TNFα1 was more highly expressed. Both isoforms increased in head kidney of meagre following injection with LPS, but this was not seen in other tissues or after injection with other PAMPs. However, in vitro studies hinted at a possible mucosal bias for TNFα1, which was more highly induced in gill and intestinal cell suspensions by PAMPs. In contrast TNFα2 was more highly induced in cells from systemic tissues. Through early development expression of both types of TNFα decreased as the meagre matured, with the exception of a transient increase shortly after the move to a dry feed diet. However, during the later stages of development expression of both isoforms increased in the gills. This data demonstrates a degree of differential expression of TNFα1 and TNFα2 in meagre with regard to expression regulation, and highlights the importance of TNFα during early development of teleost fish.     

Transference of recombinant VE-cadherin cytoplasmic domain alters endothelial junctional integrity and porcine microvascular permeability

VE-cadherin constitutes endothelial adherens junctions through a homophilic binding of its extracellular domain and by the anchoring of its intracellular domain to actin cytoskeleton via catenins. The aim of this study was to determine the functional importance of VE-cadherin–cytoskeleton association in the maintenance of endothelial junctional integrity. A recombinant VE-cadherin cytoplasmic domain (rVE-cad CPD) was expressed in E. coli and purified through Ni-NTA spin columns. Immunoprecipitation assays showed that rVE-cad CPD was able to bind β-catenin in vitro and to compete with endogenous VE-cadherin for binding of β-catenin in human umbilical vein endothelial cells. A significant increase in the transendothelial flux of albumin was observed in the endothelial cell monolayers transfected with rVE-cad CPD. Importantly, transfection of rVE-cad CPD into intact isolated coronary venules markedly elevated the albumin permeability of the venular endothelium. In addition, immunofluorescence microscopic analysis revealed a conformational change of VE-cadherin from a uniform, continuous distribution along the cell membrane under control conditions to a diffuse, stitch-like pattern after rVE-cad CPD transfection. The effects were likely due to an attenuated anchorage of endogenous VE-cadherin to the cytoskeleton, as evidenced by a decreased partitioning of VE-cadherin in the detergent-insoluble cytoskeletal pool. The results suggest that the intracellular association of VE-cadherin with β-catenin-linked cytoskeleton is essential to the maintenance of endothelial junctional integrity and microvascular permeability.     

Monocytes from sickle cell disease patients induce differential pulmonary endothelial gene expression via activation of NF-κB signaling pathway

Monocyte-endothelial interactions play an important role in inflammatory diseases and may modulate vasculopathy in sickle cell disease, a disorder with an important inflammatory component. We co-incubated normal and sickle monocytes, lymphocytes and TNF-α with pulmonary microvascular and arterial endothelial cells and compared the expression of genes coding for adhesion molecules and cytokines that might contribute to sickle vasoocclusion. Monocyte-endothelial cell co-incubation resulted in up-regulation of L-selectin, E-selectin, VCAM-1, ICAM-1, MCP-1, MMP-1, TNF-α, IL-6 and IL-1β and down-regulation of eNOS. Lymphocyte-endothelial cell co-incubations, induced similar effects restricted to pulmonary artery endothelial cells. TNF-α had similar effects on the endothelial cells as monocytes did, however monocyte induced gene expression in endothelial cells was not TNF-α dependent but was regulated through the NF-κB pathway. Sickle monocytes lead to altered expression of L-selectin, MCP-1 and MMP-1 in pulmonary vascular endothelium when compared with normal monocytes. The gene expression changes we observed could reflect pathological events of sickle vasoocclusion.     

Stimulation of Cl- secretion by AlF4- and vanadate in T84 cells.

We investigated the mechanism of Cl- secretion by fluoroaluminate(AlF4-) and sodium orthovanadate(vanadate) using the human colonic T84 cell line. T84 cell monolayers grown on collagen-coated filters were mounted in Ussing chambers to measure short circuit current(ISC). Serosal addition of AlF4- or vanadate to T84 monolayers produced a sustained increase in ISC. Removal of Ca2+ from the serosal bathing solution partially inhibited AlF4-(-)and vanadate-induced ISC, and readministration of Ca2+ restored AlF4-(-)and vanadate-induced ISC. Carbachol application in the presence of forskolin, AlF4- or vanadate induced a synergistic increase of ISC. Forskolin and vanadate significantly increased cellular cAMP level, while carbachol and AlF4- did not. Carbachol, AlF4- and vanadate significantly increased [Ca2+]i. After Na+ in mucosal bathing solution was replaced with K+, and the mucosal membrane of T84 cell was permeabilized with amphotericin B, AlF4-, vanadate, and carbachol increased K+ conductance, but forskolin did not. After sodium chloride in serosal bathing solution was replaced with sodium gluconate and the serosal membrane was permeabilized with nystatin, forskolin, AlF4-, and vanadate increased Cl- conductance, but carbachol did not. AlF4-(-)induced ISC was remarkably inhibited by the pretreatment of pertussis toxin(2 micrograms/ml) for 2 hours. These results indicate that AlF4- and vanadate can increase Cl- secretion via simultaneous stimulation of Cl- channel and K+ channel in T84 cells. However, the AlF4- action is mostly attributed to stimulation of pertussis toxin-sensitive G-proteins, whereas the vanadate action mostly results from G protein-independent mechanisms.