土槿乙酸抑制体外人胃癌细胞的生长

目的探讨土槿乙酸(PLAB)对人胃癌细胞生长的影响及机制。方法RT-PCR法检测MGC803细胞中PPARγmRNA的表达;MTT法检测细胞的生长;Hoechst333342/PI双染色法和DNA凝胶电泳检测细胞凋亡;流式细胞术检测细胞周期。结果PLAB(0.1~10μmol/L)作用MGC803细胞72 h显著抑制细胞增殖。PLAB(10μmol/L)作用后,G2期细胞随着作用时间的延长而增加,呈明显的G2期阻滞。作用72 h后,细胞出现核染色质凝集,DNA片断化等凋亡特征。在MGC803细胞中过氧化物酶增殖物激活受体γ(PPARγ)表达较弱,经PLAB(10μmol/L)作用48 h表达水平显著增加(P<0.01)。结论PLAB能在体外明显诱导MGC803细胞G2期阻滞和凋亡,该作用可能与PPARγ激活有关。     

电磁脉冲辐射诱导小鼠成纤维细胞系NIH/3T3凋亡的研究

目的 研究电磁脉冲（EMP）辐射对小鼠成纤维细胞系（NIH／3T3）凋亡的影响，并探讨EMP对生物体损伤的可能机制。方法 利用场强为60kV/m的EMP对生物体损伤的可能机制。方法 利用场强为60kV/m的EMP照射细胞后，采用细胞计数，MTT比色法，流式细胞术及免疫组化染色等方法，分别观察EMP对HIN／3T3细胞的活力，凋亡以及Bcl-2和p53蛋白表达等的影响。对免疫组化染色阳性的细胞，在高倍镜下用CMIAS－Ⅱ图像－分析系统进行图像分析，所有数据均经SPSS8．0软件进行分析。结果 EMP可明显抑制NIH／3T3细胞的增殖与活力（P＜0．05）；非贴壁细胞率在辐射后明显增加，6h达高峰（33．9％），并可诱导细胞明显凋亡，6h达高峰（15．07％）。图像分析结果表明，EMP辐射后，有不同程度的Bcl-2蛋白表达的下调及p53蛋白表达的上调（P＜0．05）。结论 EMP可诱导NIH／3T3细胞凋亡及Bcl-2及p53蛋白异常表达，提示Bcl-2及p53可能参与了NIH／3T3细胞的凋亡过程。     

p53,Bcl—2,Caspases在一氧化氮诱导凋亡的信号传递机制中作用的 …

一氧化氮可以诱导多种细胞产生凋亡,但其机制尚未阐明。近年来的研究发现,ＮＯ诱导细胞凋亡过程中,抑癌基因Ｐ５３表达增加、原癌基因Ｂｃｌ－２表达下降,以及ｃａｓｐａｓｅ－３半胱氨酸蛋白酶活性增强。本文对这三者及一些相关因素之间的相互联系简要介绍。     

mPer2在小鼠黑色素瘤细胞B16细胞凋亡中的作用研究

目的:研究mPer2在小鼠黑色素瘤细胞B16细胞凋亡中的作用机制。方法:将构pcDNA3.1-mper2和pcDNA3.1空质粒分别转染入小鼠黑色素瘤细胞B16中。提取两组细胞的总RNA和总蛋白,利用特异引物和抗体,分别检测两组细胞中p53和c-Myc基因在RNA和蛋白水平表达的变化。结果:RT-PCR和蛋白印迹检测均显示与转染pcDNA3.1( )空质粒相比,转染pcDNA3.1-mPer2入B16细胞后,p53的表达增高,而c-Myc表达降低。结论:mPer2可能通过抑制细胞癌基因c-Myc的表达,促进抑癌基因p53的表达,从而抑制B16细胞生长,诱导细胞凋亡。     

E2F-1诱导细胞凋亡研究进展

E2Fs转录因子具有调控细胞增殖、分化和凋亡相关基因转录的重要作用。迄今为止,在哺乳动物中已确定的E2F转录因子家族成员有7个,即E2F-1、E2F-2、E2F-3、E2F-4、E2F-5、E2F-6和E2F-7,每个E2F家族成员都有特定的功能。近年来,许多研究表明E2F-1具有特异性地诱导细胞凋亡的功能,其诱导凋亡作用与P53、P73、APAF-1、CASPASE-3、CASPASE-7、BCL-2家族、DIP、SIVA和NF-κB等因子有关。根据诱导细胞凋亡是否依赖于P53,E2F-1诱导凋亡机制分为P53依赖性和P53非依赖性方式。因此,E2F-1已成为肿瘤基因治疗的新靶点。     

Bcl—2和caspase—3在创伤性脑损伤后细胞凋亡中的作用

Bcl-2和caspase-3分别是Bcl-2基因族和caspase-3基因族中具有代表性的基因，它们参与对细胞凋亡的调控．研究表明创伤性脑损伤后存在细胞凋亡及凋亡相关基因的表达．从基因水平探讨创伤性脑损伤后细胞调亡调控机制是近年研究的一个热点．本文仅综述Bcl-2和caspase-3基因在创伤性脑损伤研究中的最新进展．     

T细胞在激活诱导凋亡中的信号途径

淋巴细胞AICD是免疫系统维持稳定的一种重要机制。现在已知的可引发AICD的途径包括CD3/TCR途径、CD2途径、CD47途径、CD30途径。它们最终将信号传递至两条凋亡途径,引起细胞死亡。第一条是死亡受体信号传导途径,其中主要包括Fas/PasL途径、Apo-TRAIL等TNF受体超家族起始的途径。另外,Bcl-2家族构成的线粒体途径可能参与一定的调节作用。     

白色念珠菌诱导小鼠胸腺细胞凋亡通路的探究

目的：探讨白色念珠菌诱导小鼠胸腺细胞凋亡的通路。方法：经小鼠尾静脉注射白色念珠菌后，用ELISA检测小鼠血清TNF-α水平；采用荧光分光光度计检测小鼠胸腺凋亡细胞caspase-3在不同时问组的活性变化；流式细胞仪检测小鼠胸腺细胞hax、p53、bcl-2基因产物水平。结果：TNF-α水平显著升高，caspase-3的活性明显增强，bax、p53基因表达上调。结论：白色念珠菌可能通过刺激机体TNF-α水平升高进而激活caspase-3，同时白色念珠菌上调bax、p53基因表达协同激活caspase-3，从而导致小鼠胸腺细胞凋亡。     

HDV/HBV感染树鼠句肝组织中的肝细胞凋亡

目的探讨HDV/HBV感染树鼠句肝组织中Fas/FasL、Bcl2/Bax和ICE表达与HDV感染之间的关系,以及Fas/FasL、Bcl2/Bax和ICE在丁型肝炎肝细胞凋亡中的作用.方法采用免疫组化技术对HDV/HBV感染树鼠句肝组织中Fas/FasL、Bcl2/Bax和ICE的表达进行检测;应用原位末端标记技术对肝细胞凋亡进行检测.结果HDAg表达与Fas/FasL、Bcl2/Bax和ICE表达之间关系密切(P＜0.05),HDAg表达越强,Fas、FasL、Bax和ICE表达也越强,而Bcl2表达则越弱.Fas/FasL、Bcl2/Bax和ICE表达与肝细胞凋亡之间关系密切(P＜0.05),Fas、FasL、Bax和ICE表达越强,凋亡细胞越多;相反,Bcl2表达越强,凋亡细胞越少.结论肝细胞内HDAg表达可诱导Fas、FasL、Bax和ICE表达,但对Bcl2表达无明显诱导作用;Fas/FasL、Bcl2/Bax和ICE在肝细胞凋亡中起重要作用.     

HDV/HBV感染树鼩肝组织中的肝细胞凋亡

目的探讨 HDV/ HBV感染树鼠句肝组织中 Fas/ Fas L、Bcl2 / Bax和 ICE表达与 HDV感染之间的关系 ,以及Fas/ Fas L、Bcl2 / Bax和 ICE在丁型肝炎肝细胞凋亡中的作用。方法采用免疫组化技术对 HDV/ HBV感染树鼠句肝组织中 Fas/Fas L、Bcl2 / Bax和 ICE的表达进行检测 ;应用原位末端标记技术对肝细胞凋亡进行检测。结果 HDAg表达与 Fas/ Fas L、Bcl2 /Bax和 ICE表达之间关系密切 ( P<0 .0 5 ) ,HDAg表达越强 ,Fas、Fas L、Bax和 ICE表达也越强 ,而 Bcl2 表达则越弱。 Fas/Fas L、Bcl2 / Bax和 ICE表达与肝细胞凋亡之间关系密切 ( P<0 .0 5 ) ,Fas、Fas L、Bax和 ICE表达越强 ,凋亡细胞越多 ;相反 ,Bcl2 表达越强 ,凋亡细胞越少。结论肝细胞内 HDAg表达可诱导 Fas、Fas L、Bax和 ICE表达 ,但对 Bcl2 表达无明显诱导作用 ;Fas/ Fas L、Bcl2 / Bax和 ICE在肝细胞凋亡中起重要作用。     

APO-1(CD95)-dependent and -independent antigen receptor-induced apoptosis in human T and B cell lines

Certain B and T cell lines respond to activation signals, e.g.through the antigen receptor, by undergoing apoptotlc cell death.In T cells it has been recently shown that TCR-mediated apoptosisinvolves APO-1/Fas (CD95) receptor-ligand interaction. To investigatewhether the TCR-CD3 complex can trigger alternative apoptosispathways we generated subclones of the T cell line Jurkat whichwere completely resistant towards APO-1-mediated apoptosis.These Jurkat^R cells differed phenotypically from sensitive parentalJurkat^S cells only by the lack of APO-1 protein expression.Although Jurkat^R cells responded normally to anti-CD3 stimulationby expression of APO-1 ligand they failed to undergo anti-CD3-inducedapoptosis. Thus, in Jurkat cells APO-1 -mediated apoptosis wasthe main, and might be the only, mechanism for anti-CD3-inducedcell death. However, BL-60 B cells, highly sensitive to anti-IgM-inducedapoptosis, did not use the APO-1 receptor-ligand system becausethey failed to express APO-1 ligand mRNA. Taken together, ourresults suggest that malignant T and B cell lines may use APO-1receptor-ligand-dependent and -independent antigen receptor-inducedapoptosis pathways respectively. Similarly, differential pathwaysmay be used by T and B cell subsets.     

大鼠骨髓间充质干细胞体外诱导肝星状细胞系凋亡

目的 研究大鼠骨髓间充质干细胞（MSCs）体外诱导大鼠肝星状细胞（HSCs）凋亡及其机制。方法 分离培养MSCs, HSC-T6系及纤维原细胞系冻融后传代使用。用6孔塑料培养板,建立上下双层细胞共培养体系。分3组：⑴空白对照组⑵阴性对照组⑶实验组。以上体系培养观察24、48和72h,于倒置相差显微镜下动态观察HSCs细胞形态;免疫组化法检测HSCs a-SMA表达;WST-8法检测HSCs增殖抑制率;流式细胞仪Annexin-V-FITC/PI双染法和DNA凝胶电泳（DNA Ladder ）检测HSCs细胞凋亡;RT-PCR 、Western blot检测HSCs Caspase-3、Bax基因mRNA和蛋白表达。结果 实验组出现明显的DNA Ladder,24h后HSCs 增殖抑制率、凋亡率和Caspase-3, Bax mRNA和蛋白表达呈时间依赖性,显著高于对照组。（P<0.01）结论 MSCs可在体外抑制HSCs增殖,可能通过旁分泌途径诱导HSCs凋亡,其凋亡发生是通过上调Caspase-3、Bax表达发挥作用,本研究支持MSCs通过抑制HSCs产生抗肝纤维化机制。     

Reduced susceptibility to Fas-mediated apoptosis in B-1 cells

Elimination of activated T and B cells by Fas-dependent apoptosis may contribute to the maintenance of peripheral tolerance. CD40 ligation was recently shown to up-regulate Fas expression and enhance susceptibility to Fas-mediated apoptosis in mouse splenic B cells. In the present study, we have investigated the regulation of Fas expression and Fas-triggered apoptotis in mouse peritoneal B-1 cells. B-1 cells expressed a similar level of CD40 as that on B-2 cells, and proliferated in response to a soluble CD40 ligand (CD40L)-CD8α chimeric protein, suggesting that CD40 on B-1 cells is functional. In contrast to B-2 cells, B-1 cells expressed Fas at only low levels in response to CD40L-CD8α alone or CD40L-CD8α+interleukin-4, and were resistant to Fas-mediated apoptosis following these treatments. While Fas expression could be induced in B-1 cells to a comparable level as that in B-2 cells by cross-linking CD40L-CD8α with an anti-CD8α antibody, the sensitivity to Fas-mediated apoptosis in B-1 cells was significantly reduced compared with B2 cells. These results suggest that peritoneal B-1 cells from normal mice have a lower susceptibility to Fas-mediated apoptosis and may distinguish B-1 from B-2 cells. Similarly, B-1 cells from the peritoneal cavity and spleen of autoimmune-prone NZB mice exhibited reduced susceptibility to Fas-mediated apoptosis relative to their B-2 counterparts. NZB splenic B-1 cells, however, were more susceptible to Fas-mediated apoptosis than NZB peritoneal B-1 cells. The results presented here raise the possibility that the reduced susceptibility to Fas-triggered apoptosis in B-1 cells might be an accelerating factor for the autoantibody production in NZB mice.     

Apoptosis in human endometrium and endometriosis

Apoptosis plays a critical role in maintaining tissue homeostasis and represents a normal function to eliminate excess or dysfunctional cells. Accumulated evidence suggests that apoptosis helps to maintain cellular homeostasis during the menstrual cycle by eliminating senescent cells from the functional layer of the uterine endometrium during the late secretory and menstrual phase of the cycle. The BCL-2 family and Fas/FasL system have been extensively studied in human endometrium and endometriotic tissues. Eutopic endometrium from women with endometriosis reportedly has some fundamental differences compared with normal endometrium of women without endometriosis. The differences could contribute to the survival of regurgitating endometrial cells into the peritoneal cavity and the development of endometriosis. One mechanism that recently gained a lot of interest is the finding that apoptosis appeared in eutopic and ectopic endometrium of patients with endometriosis. This study is a current review of the literature focused on the physiological role of apoptosis in normal endometrium and the alterations in regulation of apoptosis in eutopic and ectopic endometrium from women with endometriosis. Similarities in characteristics of endometriosis at a molecular level with gynaecological tumours are also discussed. Finally, the role of apoptosis in the treatment of endometriosis is reviewed to link the basic research findings into clinical applications.     

抗HER-2抗体chA21对人乳腺癌SKBR3细胞凋亡的诱导作用及其机制

目的探讨抗HER-2工程抗体chA21在体外对高表达HER-2的人乳腺癌SKBR3细胞凋亡的诱导作用及其分子机制。方法采用透射电镜和原位末端标记技术(TUNEL)观察和检测chA21对SKBR3细胞凋亡的诱导,采用免疫细胞化学技术检测凋亡相关基因bc l-2、bax、Fas及caspase-3表达的改变。结果chA21作用72 h,可见SKBR3细胞凋亡,chA21高浓度组(5.4mg/L)凋亡指数显著高于低浓度组(0.2 mg/L)(P<0.01);chA21处理组SKBR3细胞的bax、Fas及caspase-3表达增加,而bc l-2表达及bc l-2/bax比值降低,上述改变在chA21高、低两个浓度组间有显著差异(P<0.01)。结论chA21在体外可诱导SK-BR3细胞凋亡,其分子机制与调节凋亡相关基因bax、bc l-2、Fas及caspase-3的表达有关。     

Surface expression of TRAIL/Apo-2 ligand in activated mouse T and B cells

Like other members of the TNF family, TRAIL/Apo-2 ligand induces apoptosis in sensitive target cells in a caspase-dependent fashion. We recently found that TRAIL may be constitutively expressed on the surface of mouse and human tumor cells of T and B origin. To define the pattern of TRAIL expression in normal immune cells, freshly isolated splenocytes, Concanavalin A/IL-2-activated T cells and lipopolysaccharide-activated B cells were analyzed by surface staining with or without secondary stimulation. Activated, but not resting, CD3⁺ cells expressed TRAIL in an activation-dependent fashion. Conversely, freshly isolated B220⁺ cells displayed surface TRAIL and CD95L that were retained following activation. Restimulation with the protein kinase C activator phorbol 12-myristate 13-acetate and the calcium ionophore ionomycin or an agonistic anti-CD3 monoclonal antibody induced significant up-regulation of surface TRAIL and CD95L in CD3⁺ , TCRα β cells with CD4⁺ or CD8⁺ phenotype. Similarly to CD95L, TRAIL up-regulation was protein synthesis dependent and cyclosporin A sensitive. These results indicate that both TRAIL and CD95L are displayed on the cell surface of activated immune cells and may thus represent complementary effector pathways in the regulatory functions of T and B cells.     

Differential regulation of TRAIL and CD95 ligand in transformed cells of the T and B lymphocyte lineage

TRAIL (APO-2 ligand) and CD95L (CD95/APO-1/Fas ligand) share the highest homology among the TNF family members and the ability to induce apoptosis. These similarities raise the issue of a potential functional redundancy between the two ligands. We have previously shown that CD95L-resistant cells may be sensitive to TRAIL, even though apoptosis induced by both ligands is blocked by caspase inhibitors. Here we investigated TRAIL protein expression in cells of T and B origin and compared its regulation of expression with that of CD95L. A rabbit antibody (Ab) to a peptide sequence in the extracellular region of TRAIL identified recombinant TRAIL (rTRAIL) produced by Sf9 cells as a protein of approximately 32 – 33 kDa and soluble rTRAIL as a 19 – 20-kDa protein. In human and mouse cells, the Ab identified a 33 – 34-kDa and an additional 19 – 20-kDa protein only in human cells. Both transformed cells of the T and B lymphocyte lineage were found to react with the anti-TRAIL Ab by immunoblot analysis and surface staining. The majority of the cells analyzed co-expressed TRAIL and CD95L. Two cell lines showed a mirror-pattern, one being TRAIL^high CD95L^low and the other TRAIL^low CD95L^high, thus suggesting the existence of a cell type-specific regulation of expression of the two ligands. Differently from CD95L, surface TRAIL was not up-regulated by any of the metalloprotease inhibitors tested, independently of the cell type analyzed. Conversely, reactivity with the anti-TRAIL but not with the anti-CD95L Ab was enhanced by cysteine protease inhibitors. An in vitro cleavage assay showed that generation of soluble rTRAIL was dependent on the functional activity of cysteine proteases, as it was blocked by leupeptin and E64 but not by the metalloprotease inhibitor 1,10-phenanthroline. Thus, even though TRAIL and CD95L share structural and functional properties, they have unique properties as they differ in their regulatory pathways, i. e. cell-type-dependent expression and sensitivity to protease inhibitors.     

雌激素减轻H2O2诱导PCI2细胞凋亡

目的 观察雌激素对H2O2诱导细胞凋亡的作用,探讨雌激素保护作用机制.方法 在PCI2细胞建立H2O2诱导细胞凋亡的实验模型.用MTT法检测细胞存活率,比色法测定乳酸脱氢酶(LDH)活性,Hoechst染色检测细胞凋亡,碘化丙啶(PI)染色流式细胞术检测细胞凋亡率,比色法测定caspase-3活性.结果 H2O2明显降低PCI2细胞的存活率,使LDH释放增加,促进细胞凋亡,并能明显地升高caspase-3的活性.雌激素能显著地减轻上述变化.结论 雌激素对抗H2O2诱导的细胞凋亡,抑制caspase-3的激活是其细胞保护机制之一.