CD147在亲环素A诱导Jurkat细胞增殖、活化和趋化过程中的作用

目的 探讨CD147分子在亲环素A(CyPA)诱导的Jurkat细胞增殖、活化和趋化过程中的作用.方法 采用RT-PCR法和Western blot法证实CD147小干扰RNA(siRNA)转染Jurkat细胞的有效性.不同浓度CyPA(0.01、0.10、1.00、10.00 nmol/L)及PBS作用于CD147 siRNA转染前后的Jurkat细胞,采用MTT法检测CyPA作用24和48 h后细胞增殖水平;流式细胞术检测细胞表面T细胞活化标志分子CD25的表达;以Transwell小室法和基质黏附实验分别检测细胞趋化能力和黏附能力.结果 CD147 siRNA转染的Jurkat细胞CD147mRNA和蛋白表达水平较空转细胞显著下降;CyPA以浓度依赖性方式促进Jurkat细胞增殖,CyPA浓度为10.00 nmol/L时促增殖作用最强,阻断CD147表达使CyPA促细胞增殖作用下降;CyPA可促进Jurkat细胞的活化,阻断CD147表达致CyPA促细胞活化能力下降;CyPA对Jurkat细胞有趋化作用,趋化指数为2.32,阻断CD147表达后细胞趋化活性显著降低;CyPA对Jurkat细胞的黏附能力无明显影响.结论 CD147分子在CyPA诱导的Jurkat细胞活化、增殖和趋化过程中发挥作用.     

阿司匹林对Jurkat细胞体外作用的实验研究

目的:探讨非甾体类抗炎药阿司匹林对存在有β-连环素异常表达的T淋巴细胞白血病Jurkat细胞株的作用及机制.方法:MTT法观察阿司匹林对Jurkat细胞的增殖抑制作用,流式细胞仪(FCM)检测阿司匹林对Jurkat细胞细胞周期分布的影响.实时荧光定量RT-PCR法分析经不同浓度的阿司匹林处理后的Jurkat细胞β-连环素及CyclinD1基因的表达水平的改变.结果:阿司匹林呈剂量依赖性抑制Jurkat细胞的增殖,72 h半数抑制浓度为1.78 mmol/L;随浓度增加,CyclinD1基因及蛋白的表达水平均下调.结论:非甾体类抗炎药阿司匹林可能通过影响Wnt信号通路调节某些细胞周期相关基因的表达,将Jurkat细胞阻滞于G0/G1期,从而抑制白血病细胞株Jurkat的增殖.     

Different effects of two cyclic chalcone analogues on redox status of Jurkat T cells

Chalcones are intermediary compounds of the biosynthetic pathway of the naturally flavonoids. Previous studies have demonstrated that chalcones and their conformationally rigid cyclic analogues have tumour cell cytotoxic and chemopreventive effects. It has been shown that equitoxic doses of the two cyclic chalcone analogues (E)-2-(4′-methoxybenzylidene)-(2) and (E)-2-(4′-methylbenzylidene)-1-benzosuberone (3) have different effect on cell cycle progress of the investigated Jurkat cells. It was also found that the compounds affect the cellular thiol status of the treated cells and show intrinsic (non-enzyme-catalyzed) reactivity towards GSH under cell-free conditions. In order to gain new insights into the cytotoxic mechanism of the compounds, effects on the redox status and glutathione level of Jurkat cells were investigated. Detection of intracellular ROS level in Jurkat cells exposed to 2 and 3 was performed using the dichlorofluorescein-assay. Compound 2 did not influence ROS activity either on 1 or 4 h exposure; in contrast, chalcone 3 showed to reduce ROS level at both timepoints. The two compounds had different effects on cellular glutathione status as well. Compound 2 significantly increased the oxidized glutathione (GSSG) level showing an interference with the cellular antioxidant defence. On the contrary, chalcone 3 enhanced the reduced glutathione level, indicating enhanced cellular antioxidant activity. To investigate the chalcone–GSH conjugation reactions under cellular conditions, a combination of a RP-HPLC method with electrospray ionization mass spectrometry (ESI-MS) was performed. Chalcone–GSH adducts could not be observed either in the cell supernatant or the cell sediment after deproteinization. The investigations provide further details of dual – cytotoxic and chemopreventive – effects of the cyclic chalcone analogues.     

七叶皂苷钠抑制人白血病Jurkat细胞增殖的机制研究

目的研究七叶皂苷钠抑制人白血病Jurkat细胞增殖的作用及其机制。方法 MTT法分析七叶皂苷钠对Jurkat细胞增殖的抑制作用,Hoechst 33258染色、FITC-Annexin V/PI双染、DNA Ladder、流式细胞术检测细胞凋亡和细胞周期,Western blotting法分析凋亡相关蛋白变化。结果七叶皂苷钠呈质量浓度和时间相关方式抑制Jurkat细胞增殖;经七叶皂苷钠处理后的Jurkat细胞出现凋亡的形态学特征、DNA条带,Annexin V+/PI细胞(早期凋亡细胞)显著增加;七叶皂苷钠可活化Jurkat细胞中Caspase-8、Caspase-9、Caspase-3,引起PARP的切割,并减少Bcl-2蛋白的表达。结论七叶皂苷钠能有效地通过诱导细胞凋亡抑制Jurkat细胞增殖。     

盐酸小檗碱诱导Jurkat细胞凋亡的研究

目的本研究旨在观察盐酸小檗碱能否抑制Jurkat细胞的增殖、并对其作用机制进行初步探讨。从而为临床上应用治疗急性T淋细胞白血病提供实验依据。方法MTT比色法检测盐酸小檗碱对Jurkat细胞增殖的影响;AO／EB染色法观察细胞凋亡的形态学改变;TUNEL方法检测细胞凋亡的生化功能变化。结果盐酸小檗碱对Jurkat细胞的生长有抑制作用,呈现明显的剂量和时间依赖性,24h、48h、72h、96h、120h的IC50分别为107．5567μg·mL^-1、23．5600μg·mL^-1、10．8069μg·mL^-1、9．2660μg·mL^-1和2．7121μg·mL^-1盐酸小檗碱处理Jurkat细胞可见典型的细胞凋亡形态学改变;TUNEL可见深棕色凋亡细胞。结论盐酸小檗碱能有效地抑制体外Jurkat细胞的增殖,其作用可能是通过诱导Jurkat细胞凋亡有关。     

抗人DR5功能性单克隆抗体诱导Jurkat细胞凋亡的线粒体途径的分子机制

目的:探讨抗人死亡受体5(DR5)功能性单克隆抗体(mDRA-6)对Jurkat细胞诱导凋亡的线粒体途径的分子机制。方法:MTT法检测单克隆抗体(mDRA-6)对Jurkat细胞生长抑制作用的剂量-效果及时间-效果关系;JC-1单染流式细胞术定量分析技术对凋亡的Jurkat细胞线粒体膜电位的变化进行分析;免疫印迹技术检测凋亡细胞的Caspase-8、3、9及Bid、Bax、Bcl-2、Cytoc等凋亡相关蛋白的表达情况。结果:mDRA-6对Jurkat细胞抑制具有明显剂量-效果和时间-效果关系;流式细胞仪检测显示,2.0μg/ml浓度的mDRA-6作用15、30、60和120分钟时,Jurkat细胞线粒体膜电位改变率分别为20.14%、19.34%、21.11%、30.90%,呈逐渐增高趋势。免疫印迹技术检测显示,mDRA-6作用后,Jurkat细胞Caspase-8、9及Bid、Bax、Bcl-2、Cytoc等表达活性增加,并且Cytoc在线粒体内为递减而在胞浆呈递增的表达现象。结论:mDRA-6通过激活外源性膜受体,继而启动细胞线粒体途径导致Jurkat细胞凋亡。本研究为mDRA-6对白血病治疗奠定实验基础。     

Jurkat(E6-1)细胞TCR alpha和beta链重排基因家族取用分析

目的 探讨人T淋巴细胞白血病细胞株Jurkat(E6-1)TCR alpha和beta链的重排基因家族的取用及基因、氨基酸序列与结构,为Jurkat细胞做为单克隆T细胞研究的模型提供基础.方法 采用T细胞TCR的免疫扫描谱型分析技术(im-munoscope spectratyping),监测Jurkat细胞的alpha和beta链各基因家族的取用,ABI测序仪测序出各取用家族基因的序列,并分析其氨基酸组成(DNA tools软件),模拟H{TCR的结构(CPH modle 2.0 Server和Informax 9.0).结果 Jurkat细胞TCR alpha链的基因家族取用为:可变区为TRAV1,连接区为TRAJ3;beta链的基因家族取用为:可变区为TRBV8S1,连接区为TRBJIS2.结论 Jurkat(F6-1)细胞的TCR alpha和beta链基因、氨基酸序列和结构的确定,将为Jurkat做为效应T细胞、TCR重排模型等方面的研究提供基础.     

Melatonin exerts differential actions on X-ray radiation-induced apoptosis in normal mice splenocytes and Jurkat leukemia cells

Abstract:  The ability of melatonin as a potent antioxidant was used as a rationale for testing its antiapoptotic ability in normal cells. Recently, melatonin was shown to possess proapoptotic action by increasing reactive oxygen species in certain cancer cells. The modification of radiation-induced apoptosis by melatonin and the expression of apoptosis-associated upstream regulators were studied in normal mice splenocytes and Jurkat T leukemia cells. C57BL/6 mice were exposed to a single whole body X-ray radiation dose of 2 Gy with or without 250 mg/kg melatonin pretreatment. The Jurkat cells were divided into four groups of control, 1 m m melatonin alone, 4 Gy irradiation-only and melatonin pretreatment before irradiation. The highest level of apoptosis in the normal splenic white pulp was detected by TUNEL assay at 8 hr after irradiation. At this time, the apoptotic index of irradiation-only and melatonin pretreatment groups were 35.6% and 20.7%, respectively. This reduced apoptosis by melatonin was associated with the increase of Bcl-2 expression and a reduction of Bax/Bcl-2 ratio through a relative decrease of p53 mRNA and protein. In the Jurkat cells treated with a combination of melatonin and radiation, both Annexin V-FITC(+)/PI(−) and Annexin V-FITC(+) cells were increased at 48 hr after irradiation when compared with irradiation-only or melatonin alone. The expressions of p53 between groups were well correlated with the results of Annexin V binding. The irradiation or melatonin did not influence the JNK1 expression in Jurkat cells. The present results suggest that melatonin enhances radiation-induced apoptosis in Jurkat leukemia cells, while reducing radiation-induced apoptosis in normal mice splenocytes. These differential effects on radiation-induced apoptosis by melatonin might involve the regulation of p53 expression.     

The New Isothiocyanate 4-(Methylthio)Butylisothiocyanate Selectively Affects Cell-Cycle Progression and Apoptosis Induction of Human Leukemia Cells

We investigated proliferation and apoptosis induction in Jurkat T-leukemia cells by the new isothiocyanate 4-(methylthio)butylisothiocyanate (MTBITC). To help elucidate whether the effects of MTBITC are specific for cancer cells, we tested MTBITC on freshly isolated, non-transformed human peripheral T lymphocytes. The effects of MTBITC are leukemic-cell-specific and consist of derangements in a critical point of cell-cycle control (G2/M transition). In fact, an increase in the proportion of G2 cells (from about 18% to 50%) was apparent following 24 h of treatment, associated with a decrease in the protein expression of cyclin B1. The expression of cyclin-dependent kinase (CDK) 1 was more mildly attenuated by MTBITC. Our results demonstrated that high concentrations of MTBITC can also induce apoptosis, through an increase of p53 and bax, but not bcl-2, protein expression. No effects of MTBITC were demonstrated on non-transformed T lymphocytes. Taking into account its in vitro antineoplastic activity and selectivity toward leukemia cells, MTBITC can be viewed as a conceptually promising agent in cancer therapy.     

PMA、抗CD3、PHA和A23187对Jurkat细胞表达Tac抗原和高亲和性IL-2受体的调变作用

本文运用~(125)Ⅰ标记的CD25单克隆抗体和IL-2进行竞争结合试验,发现抗CD3单克隆抗体、PHA和Ca~(++)载体A23187均明显抑制PMA诱导Jurkat细胞Tac抗原的表达。抑制率分别为50.0％、74.5％和87.8％。静止的Jurkat细胞不具有任何亲和性的IL-2结合受体,PMA(20ng/ml)刺激24h后,每个细胞表面表达509个高亲和性IL-2受体,KD值为381PM。