慢性HBV感染时影响肝细胞Fas表达的因素

继往的研究显示Ｆａｓ分子是介导肝细胞凋亡与损伤的关键分子,肝细胞Ｆａｓ分子的表达强度与其组织学损伤程度相一致,因此,调节Ｆａｓ分子的表达必然有助于肝病的治疗,但是哪些因素影响肝细胞Ｆａｓ分子的表达至今仍不明确,本研究旨在阐述慢性ＨＢＶ感染时影响肝细胞...     

乙型肝炎血清可溶性Fas与FasL的检测

ＦａｓＬ和Ｆａｓ是介导细胞凋亡的一对重要的细胞膜表面死亡分子及其受体 ,表达ＦａｓＬ的细胞可介导表达Ｆａｓ的靶细胞发生凋亡。细胞毒性Ｔ细胞 (ＣＴＬｓ)介导的细胞免疫在乙型肝炎的发病机制中起着重要作用 ,其主要机制是通过ＦａｓＬ介导Ｆａｓ阳性的肝细胞凋亡[1] 。因此 ,Ｆａｓ/ＦａｓＬ介导的细胞凋亡机制与乙型肝炎的发生发展有着密切关系。迄今 ,有关肝病Ｆａｓ和ＦａｓＬ的研究大多限于肝组织原位 ,至于其可溶性Ｆａｓ(ｓＦａｓ)和可溶性ＦａｓＬ(ｓＦａｓＬ)与肝病的关系尚不清楚 ,两者在乙型肝炎中的变化也未见报道。本研究…     

慢性乙型肝炎肝细胞Fas表达和DNA损伤

为了解凋亡对慢性乙型肝炎病变的意义，对３８例不同重度的慢性乙型肝炎病人的活检肝组织，以地高辛素标记的核苷酸（ＴＵＮＥＬ）试验原位检测肝细胞凋亡和以免疫组化检测Ｆａｓ表达。结果凋亡少见，而许多完好肝细胞核ＴＵＮＥＬ阳性，表示有ＤＮＡ损伤。轻型慢性肝炎１７例中，Ｆａｓ表达和ＤＮＡ损伤检测各有１４例阴性或弱阳性；中型７例无强阳性表达；重型１４例中Ｆａｓ表达强阳性９例，ＤＮＡ重度损伤３例。两者主要分布在碎屑样坏死区，与细胞坏死同时存在。提示细胞毒性Ｔ细胞（经Ｆａｓ配体）－Ｆａｓ－凋亡也是参与肝细胞损伤的重要机制     

乙型肝炎患者血清可溶性Fas检测的临床意义

Ｆａｓ（ＣＤ９５）是介导凋亡的细胞表面分子,肝病时肝细胞可有强表达［１,２］,提示Ｆａｓ在肝病发生中的重要作用。目前关于可溶性Ｆａｓ（ｓＦａｓ）与乙型肝炎的关系尚不清楚,本研究探讨了乙型肝炎患者血清ｓＦａｓ的临床意义。材料和方法一、研究对象及诊断标准...     

慢性肝病患者肝组织Fas抗原的表达及意义

Ｆａｓ是多种细胞表面的一种膜蛋白，为Ｆａｓ配体（ＦａｓＬ）的受体，效应细胞的ＦａｓＬ与靶细胞的Ｆａｓ结合时，可诱导靶细胞凋亡［１］．有研究报道［２］，病毒性肝炎患者肝细胞的Ｆａｓ抗原表达与肝组织病理损伤相关，本研究旨在探讨慢性乙型、丙型病毒性肝炎、肝...     

凋亡相关基因Fas、Fas配体及bax在慢性病毒肝炎组织中的表达及意义

为探讨凋亡相关基因Ｆａｓ、Ｆａｓ配体及ｂａｘ在慢性病毒性肝炎中表达的意义。采用免疫组化技术研究４８例慢性肝炎（乙型肝炎３３例,丙型肝炎１５例）组织中Ｆａｓ、ＦａｓＬ及ｂａｘ的表达。结果：慢性乙型肝炎和丙型肝炎组织中Ｆａｓ、ＦａｓＬ及ｂａｘ表达均较正常肝增加,以细胞坏死和炎细胞浸润区域增加明显。结论：凋亡相关基因Ｆａｓ、Ｆａｓ及ｂａｘ可能参与了肝炎病毒致肝细胞的损伤过程。     

慢性肝病患者外周血细胞凋亡配体的表达及意义

慢性肝病患者外周血细胞凋亡配体的表达及意义陈乃玲刘倩邓涛张晓红陈天宝武珊珊病毒性肝炎时，除细胞坏死外，在肝细胞表达的Ｆａｓ和在细胞毒性Ｔ细胞（ＣＴＬｓ）表达的Ｆａｓ配体（ＦａｓＬ）发生作用，导致凋亡也是机体清除病毒的重要原因。ＦａｓＬ的表达不限于ＣＴ...     

重型乙型肝炎肝组织Fas/Fas配体表达与肝细胞凋亡的研究

近年证明，肝细胞凋亡参与乙型和丙型肝炎的发病机制，介导肝细胞凋亡的效应细胞主要是细胞毒性Ｔ淋巴细胞（ＣＴＬ），引发凋亡的途径主要是穿孔素／颗粒酶Ｂ、Ｆａｓ／Ｆａｓ配体（ＦａｓＬ）和肿瘤坏死因子α（ＴＮＦα）受体／ＴＮＦα系统［１］；但肝细胞凋亡在重型肝炎病变中的状况研究较少。本研究旨在探讨Ｆａｓ／ＦａｓＬ介导肝细胞凋亡在重型乙型肝炎发病机制中的作用。一、资料与方法研究对象为我科近年收治的病人，试验组为重型乙型肝炎病人２４例，男２１例，女３例，年龄２１～５５岁；对照组为慢性乙型肝炎病人５５例，男４…     

慢性乙型肝炎肝组织表达FasL蛋白,mRNA及Fas的实验研究

目的研究ＦａｓＬ、Ｆａｓ在慢性乙型肝炎（ＣＨＢ）肝组织中的表达及意义。方法采用ＦａｓＬ多克隆抗体、人工合成ＦａｓＬ寡核苷酸探针对ＣＨＢ及ＨＢＶ慢性携带者肝组织进行免疫组化和原位杂交检测。部分组织同时检测Ｆａｓ抗原。结果肝组织浸润单个核细胞及肝细胞都不同程度检测出ＦａｓＬ蛋白及其ｍＲＮＡ，表达程度随肝脏炎症坏死程度加重而增加。ＦａｓＬ、Ｆａｓ阳性肝细胞分布及表达程度有一致性。结论经ＦａｓＬ、Ｆａｓ介导的细胞凋亡机制在ＣＨ致病中起重要作用，不仅存在ＣＴＬｓ介导的细胞免疫作用，肝细胞也可能通过表达ＦａｓＬ发生细胞自杀和同胞相杀     

乙型肝炎患者肝组织Fas／FasL表达及其在肝细胞凋亡中的作用

研究Ｆａｓ和Ｆａｓ配体在乙型肝炎肝细胞凋亡及坏死中的作用。方法：分别用免疫组织化学方法和原位末端标记技术检测７１例各类型乙型肝炎患者肝组织Ｆａｓ／ＦａｓＬ表达和肝细胞凋亡情况。结论：Ｆａｓ和ＦａｓＬ在肝细胞凋亡和坏死中起作用，肝细胞的直接自杀方式或自分泌及旁分泌杀伤机制，可能为乙型病毒性发病理的重要因素。     

肝癌细胞清除乙型肝炎病毒的非免疫机制

目的 试图用肝癌细胞体外培养试验,推测肝细胞表达ＣＤ９５配体是否能自身通过凋亡来清除乙型肝炎病毒。方法 诱导ＨｅｐＧ２细胞表达ＣＤ９５Ｌ,与转染ＨＢＶ,表达ＣＤＳ９５的ＨｅｐＧ２．２．１５细胞共培养,以荧光显微镜和流式细胞仪检测后者的凋亡。结果 表达ＣＤ９５Ｌ的ＨｅｐＧ２细胞杀伤表达ＣＤ９５的ＨｅｐＧ２．２．１５细胞,２４小时凋亡１６．５％,４８小时凋亡４３．０％,这一作用可用抗－ＣＤ９５阻断。     

老年人外周血淋巴细胞CD28及CD95表达变化研究

目的通过对老年人与成年人外周血淋巴细胞CD28及CD95表达水平的比较性研究,观察淋巴细胞凋亡在免疫衰老中的作用。方法采用免疫荧光标记流式细胞术,分析成年组(20~59岁)与老年组(60~90岁)各20例的外周血淋巴细胞表型水平。结果老年组CD28 CD95-[(8.80±4.86)%]及CD28 细胞[(36.32±10.38)%]明显低于成年组[(23.09±3.48)%、(52.29±4.90)%](P<0.01),而CD28-CD95 [(53.23±8.28)%]、CD95 [(80.25±7.19)%]及CD28-细胞[(63.68±10.38)%]明显高于成年组[(33.58±4.72)%、(63.18±4.12)%、(47.71±4.90)%](P<0.01)。结论老年人CD28 表达随年龄增长而下降,CD28-及CD95 表达随年龄增长而上升。提示淋巴细胞凋亡在免疫衰老中可能具有重要作用。     

缺血性脑卒中患者外周血淋巴细胞CD95和CD95L的表达及其临床意义

目的　探讨缺血性脑卒中患者外周血淋巴细胞CD95和CD95L表达的动态变化及其与病情严重程度的关系及临床意义。方法　采用流式细胞术动态检测了 36例轻中重型缺血性脑卒中患者在发病后 3d内 (最早发病后 6h)、第 7天和第 2 1天外周血淋巴细胞CD95和CD95L的表达情况 ,并选择 2 2例同期住院病人作为对照。结果　CD95和CD95L在缺血性脑卒中患者急性期是升高的 ,在发病后 6h～ 3d、第 7天、第 2 1天均高于正常 ,且在 6h～ 3d最高 (P值均 <0 .0 5 )。其升高程度与病情的严重程度有关 ,病情越重 ,升高越明显。CD95和CD95L两者之间呈正相关 (P <0 .0 5 )。结论　在缺血性脑卒中患者外周血淋巴细胞CD95和CD95L发生显著变化 ,且在不同的时间有不同的变化 ,其变化程度与临床病情的严重程度有密切关系。     

CD95 and CD95-ligand expression in endocrine pancreas of NOD, NOR and BALB/c mice

Summary The non-obese diabetic (NOD) mouse is widely used to study the pathogenesis of insulin-dependent diabetes mellitus. However, the mechanisms responsible for beta-cell destruction, in this model, are still poorly defined. The CD95/CD95L system among other effector systems has been implicated in beta-cell death. In this study we investigated in NOD, non-obese resistant (NOR) and Balb/c mice the expression of CD95 and CD95L in alpha and beta pancreatic cells by immunohistochemistry and immunofluorescence. We demonstrate that alpha cells in the islets of Langherans constitutively express CD95L forming a natural shield around beta cells. [Diabetologia (1997) 40: 1476–1479] Received: 19 August 1997 and in revised form: 3 October 1997     

狼疮性肾炎患者CD4+淋巴细胞减少机制的初步探讨

目的 :探讨CD95表达在狼疮性肾炎 (LN)患者CD4 淋巴细胞减少中所起的作用。　 方法 :采用CD4 CD95和CD8 CD95双荧光标记及CD4 细胞的原位杂交DNA链断端标记 ,结合流式细胞术和DNA琼脂糖电泳对LN患者外周血单个核细胞的免疫分型及凋亡特征进行分析。　 结果 :①LN患者较正常人CD4 细胞比例明显减少 (P <0 0 1) ,CD8 细胞比例明显升高 (P <0 0 1)。②LN患者的CD4 细胞有 5 2 1%表达CD95 ,较正常人 ( 2 4 8± 7 6% )表达明显升高 (P <0 0 1) ;而LN患者CD8 细胞表达CD95的比例 ( 2 6 1± 5 5 % )较正常人( 2 1 5± 5 9% )略有升高 (P >0 0 5 )。③DNA琼脂糖电泳显示 ,5 0 μg/L的抗 CD95IgM可以引起LN患者CD4 细胞的凋亡 ,而在正常人DNA电泳带上无DNA“Ladder”出现。采用dUTP FITC标记显示 ,经 5 0 μg/L抗 CD95IgM作用后 ,正常人CD4 细胞的标记率为 5 1± 1 4 % ,而LN患者则为 3 2 0± 5 0 % ;浓度增加到 10 0 μg/L时 ,分别增加到 17 8± 5 8%和 5 9 1± 3 4 %。　 结论 :Fas受体在LN患者CD4 细胞上的表达比例增加 ,表达Fas受体的CD4 细胞对其受体的敏感性增加 ,这可能在LN患者CD4 细胞减少的病理过程中起重要作用     

Expression of CD95(Fas) by gene transfer does not sensitize K562 to Fas-killing

CD95(Fas/Apo-1) belongs to the family of TNF receptor related molecules and is expressed on many benign and malignant types of cells. CD95 triggering is involved in the apoptotic death of lymphoid cells and may also be important in myelopoiesis. Myeloid leukemia cells are in most cases resistant to CD95 triggering despite expressing the antigen. We reasoned that myeloid leukemic cells can become sensitized to the Fas pathway of cell death if CD95 expression is restored by gene transfer. As a model, we utilized the cell line K562 which does not express CD95 on their cell surface. The gene for CD95 was introduced into K562 cells (by electroporation). As a control, the gene coding for ß-galactosidase was used. The CD95 transfected K562 cells stably expressed CD95, and had a growth pattern comparable to untransfected cells, but still remained resistant to Fas-triggering (tested using recombinant Fas-ligand). Our experiment shows that antigen expression is not a critical determinant of Fas-mediated apoptosis, but further down-stream mechanisms determine the fate of the cells. The transfected cells also had a comparable susceptibility to NK-mediated lysis which shows that the expression of CD95 does not interfere with NK-mediated lysis of target cells.     

IRF4 is modulated by CD40L and by apoptotic and anti-proliferative signals in Hodgkin lymphoma

The effects of proliferative, apoptotic and anti-proliferative stimuli on interferon regulatory factor 4 (IRF4) expression by Reed-Sternberg (RS) cells were analysed using a panel of Hodgkin lymphoma (HL)-derived cell lines. IRF4 expressed by HL cells was consistently upregulated after CD40 engagement; IRF4 was downregulated by agonistic anti-CD95 antibodies in the FAS-sensitive HDLM-2 cells and after treatment with Adriamycin and Dacarbazine, two chemotherapic agents commonly used for HL treatment. These results demonstrated, for the first time, that IRF4 was up-modulated by CD40 engagement, and down-modulated by apoptotic and anti-proliferative signals, suggesting an involvement of IRF4 also in HL pathobiology.     

Fas/APO-1 (CD95)-mediated cytotoxicity is responsible for the apoptotic cell death of leukaemic cells induced by interleukin-2-activated T cells

Apoptotic cell death is induced by the cross-linking of Fas/APO-1 receptor (CD95) in acute myelogenous leukaemia (AML) cells. Since CD95 ligand (CD95L) is expressed on interleukin-2 (IL-2)-activated T cells, we investigated the involvement of CD95-CD95L pathway in T cell-mediated cytotoxicity against AML cells. Activated CD8⁺ T cells could efficiently kill a parental CD95-sensitive AML cell line, MML-1 and, to a lesser extent, a CD95-resistant clone, MML-1R. Neither MML-1 nor MML-1R cells were killed by activated CD4⁺ T cells. The blocking monoclonal antibody (MoAb) against CD95, ZB4, caused a significant inhibition of T-cell-mediated cytotoxicity against MML-1 cells, but not against MML-1R cells. Interestingly, MML-1 cells underwent the classic nuclear morphologic changes and DNA fragmentation characteristic of apoptosis when cultured with activated T cells. Enumeration of apoptotic and necrotic nuclei showed that both apoptosis and necrosis were induced in MML-1 cells, whereas necrosis was exclusively observed in MML-1R cells. Apoptosis of MML-1 cells was completely blocked in the presence of ZB4 MoAb. Similarly, blocking by ZB4 MoAb significantly inhibited T-cell-mediated lysis of fresh AML cells in a CD95-sensitive group, but not in a CD95-refractory group. In addition CD8⁺ T cells expressed CD95L mRNA more abundantly than CD4⁺ T cells upon activation by IL-2. These findings suggest that T-cell-mediated cytotoxicity against AML cells requires participation of CD95-CD95L pathway for cytotoxic signal transduction leading to target apoptosis.     

表达CD95L的HepG_2细胞自分泌和旁分泌的细胞毒效应

目的阐明乙型肝炎时肝细胞可表达细胞毒效应分子ＣＤ９５Ｌ的效应机制。方法ＨｅｐＧ２细胞诱导表达ＣＤ９５Ｌ,与ＨｅｎＧ２．２．１５细胞共培养;或以其培养上清液加于另一份未经诱导的ＨｅＰＧｚ细胞中,以流式细胞仪检测后者的凋亡率;以单个ＨｅｐＧ２细胞培养试验自体凋亡。结果表达ＣＤ９５Ｌ的ＨｅｐＧ２细胞致表达ＣＤ９５的ＨｅｐＧ２．２．１５细胞的凋亡率为：２４小时时１６．５％,４８小时时４３．０％;培养上清液引起的凋亡率：２４小时时３８．７％,４８小时时７３．３％,单个ＨｅｐＧ２细胞经诱导的自杀率２４小时为４３．８％,均高于各自的对照。结论ＨｅｐＧｅ细胞以ＣＤ９５Ｌ的膜性或可溶性分子、经旁分泌或自分泌发生“自杀”或“同胞相杀”。     

MORTl/FADD is involved in liver regeneration

AIM: To explore the role of the adaptor molecule in liver regeneration after partial hepatectomy (PH). METHODS: We used transgenic mice expressing an N-terminal truncated form of MORT1/FADD under the control of the albumin promoter. As previously shown, this transgenic protein abrogated CD95- and CD120a-mediated apoptosis in the liver. Cyclin A expression was detected using Western blotting. ELISA and RT-PCR were used to detect IL-6 and IL-6 mRNA, respectively. DNA synthesis in liver tissue was measured by BrdU staining. RESULTS: Resection of 70% of the liver was followed by a reduced early regenerative response in the transgenic group at 36 h. Accordingly, 36 h after hepatectomy, cyclin A expression was only detectable in wild-type animals. Consequently, the onset of liver mass restoration was retarded as measured by MRI volumetry and mortality was significantly higher in the transgenic group. CONCLUSION: Our data demonstrate for the first time an involvement of the death receptor molecule MORT1/ FADD in liver regeneration, beyond its well described role as part of the intracellular death signaling pathway.