Fas可能是雷公藤红素诱导HMC—1细胞凋亡的途径之一

目的：探讨雷公藤红素对ＨＭＣ－１细胞表达Ｆａｓ、Ｆａｓ－Ｌ的影响及凋亡的关系。方法：以式细胞仪检测细胞凋亡和Ｆａｓ、Ｆａｓ－Ｌ的表达。结果：ＨＭＣ－１细胞能自发表达Ｆａｓ,不表达Ｆａｓ－Ｌ。经雷公藤红素作用,Ｆａｓ呈先升后降的变化,Ｆａｓ－Ｌ水平表达。Ｆａｓ阳性率下降与凋亡率增加相关。结论：Ｆａｓ可能是雷公藤红素诱导ＨＭＣ－１细胞凋亡的途径之一。     

雷公藤红素诱导多发性骨髓瘤H929细胞凋亡

目的:研究雷公藤红素对人多发性骨髓瘤H929细胞凋亡的诱导作用及分子机制。方法:体外培养H929细胞,加入不同浓度(0.5、1、5和10 mg/L)的雷公藤红素处理细胞,CCK8法分析药物对细胞活力的抑制率;annexin V-PE/7-AAD双染法检测雷公藤红素对H929细胞凋亡的影响;流式细胞术分析雷公藤红素处理的H929细胞中线粒体膜电位水平;彗星电泳实验分析雷公藤红素对细胞DNA损伤的诱导作用;Western blot分析不同浓度的雷公藤红素对H929细胞中凋亡相关分子P53、XIAP、cleaved PARP-1和cleaved caspase-3的蛋白水平以及线粒体细胞色素C释放的影响。结果:不同浓度雷公藤红素处理H929细胞后明显抑制细胞的活力,并呈浓度依赖和时间依赖性。雷公藤红素呈浓度依赖地诱导H929细胞凋亡,并且降低线粒体膜电位水平(P<0.05)。彗星电泳实验结果显示雷公藤红素可以诱导H929细胞的DNA损伤。Western blot实验结果显示雷公藤红素处理的H929细胞中,促凋亡蛋白P53、cleaved PARP-1和cleaved caspase-3...     

雷公藤红素诱导CEM-6T细胞凋亡的机制研究

在已经证明雷公藤红素能诱导人T淋巴细胞株CEM 6T细胞凋亡的基础上 ,进一步探讨此凋亡过程的机制。本项目研究雷公藤红素诱导CEM 6T细胞凋亡过程中Fas/FasL、ICEmRNA的变化以及ICE抑制剂、磷酸酶抑制剂对凋亡的影响。结果发现 ( 1)CEM 6T细胞表达Fas,不表达FasL ,雷公藤红素处理不能改变这一情况 ;( 2 )雷公藤红素不能改变ICEmRNA的表达水平 ,但ICE抑制剂Ac YVAD CHO能使雷公藤红素诱导CEM 6T的凋亡率下降 ;( 3) 1 5 μmol/L磷酸酶抑制剂okadaicacid能使凋亡率下降。提示雷公藤红素诱导CEM 6T细胞凋亡不依赖Fas/FasL ,而与细胞内原已存在的ICE有关 ,蛋白去磷酸化参与了此凋亡过程     

雷公藤红素通过ROS/JNK途径诱导Saos-2细胞发生caspase依赖的凋亡

目的:探讨雷公藤红素对人骨肉瘤细胞Saos-2的杀伤作用及相关机制。方法:将人骨肉瘤细胞Saos-2用各种不同的浓度的雷公藤红素治疗后,采用MTT法检测雷公藤红素对Saos-2细胞活力的抑制作用;采用流式细胞术检测用雷公藤红素处理后Saos-2细胞的凋亡及活性氧簇(ROS)的产生;Western blot检测雷公藤红素处理后Saos-2细胞cleaved caspase-9、cleaved caspase-3和磷酸化JNK的表达水平。结果:雷公藤红素有显著的体外抗骨肉瘤作用,能显著抑制Saos-2细胞的活力。雷公藤红素可显著诱导Saos-2细胞发生凋亡,产生ROS。雷公藤红素处理后Saos-2细胞cleaved caspase-9、cleaved caspase-3和磷酸化JNK的表达水平均显著上升。结论:雷公藤红素通过ROS/JNK途径诱导人骨肉瘤Saos-2细胞发生caspase依赖的凋亡。     

Quercetin调节肝癌HepG2细胞Fas表达诱导细胞凋亡

目的： 探讨三磷酸肌醇( IP3) 和Fas基因表达变化在quercetin诱导肝癌细胞凋亡中的作用。方法: 以肝癌HepG2 细胞培养72 h为对照, 20、40、60、80 μmol/ L quercetin作用于 HepG2 细胞72 h和60 μmol/L quercetin 作用于HepG2 细胞6 h、12 h、24 h、48 h、72 h,应用同位素试剂盒IP3 - ［3H］ Birtrak检测细胞IP3 含量，RT-PCR分析Fas mRNA表达，Western blotting 分析细胞Fas蛋白表达，流式细胞仪检测细胞凋亡率。结果: 各浓度的quercetin作用于肝癌HepG2 细胞72 h，IP3 含量显著低于对照组［（17.9±1.5 ）pmol/106cells、（15.5±1.1）pmol/106cells、（5.7±0.9）pmol/106cells、（5.5±0.8）pmol/106cells vs （29.4±0.5）pmol/106cells］，Fas mRNA表达显著高于对照组［RI 0.26±0.01、0.30±0.01、0.30±0.02、0.37±0.02 vs 0.19±0.02］，Fas蛋白表达显著高于对照组［RI（灰度与面积之积的相对强度）1.10±0.08、 0.91±0.02、0.78±0.07、0.73±0.05 vs 0.15±0.01］，细胞凋亡率显著高于对照组［（11.2±1.1）%、（15.5±1.1）%、（26.8±2.5）%、（27.1±1.5）% vs （2.6±0.1）%］； 60 μmol/L quercetin 作用于肝癌HepG2 细胞6 h、12 h、24 h、48 h、72 h ，各时相IP3 含量显著低于对照组［（23.3±1.4）pmol/ 106cells、 (12.0±1.4) pmol/ 106cells、(7.5 ±0.8) pmol/ 106cells、(5.6 ±0.5) pmol/ 106cells、(4.3 ±0.6) pmol/ 106cells vs (29.2 ±0.6) pmol/106cells,P<0.01］；12 h后Fas mRNA表达显著高于对照组［RI 0.26±0.02、0.28±0.02、0.26±0.01、0.24±0.01 vs 0.20±0.01］，Fas蛋白表达显著高于对照组［RI 0.65±0.17、 1.20±0.07、1.51±0.06、1.50±0.06、0.97±0.17 vs 0.18±0.01］，24 h后各时相细胞凋亡率显著高于对照组［(7.4 ±0.5)%、(20.5 ±2.0)%、(30.7 ±1.6)% vs (2.6 ±0.1)%，P< 0.01］。结论: Quercetin能减少IP3 生成，上调Fas基因表达，诱导肝癌细胞凋亡。     

抗Fas抗体诱导人肾小球系膜细胞凋亡

研究抗Ｆａｓ抗体对人肾小球系膜细胞的致凋亡作用，探讨Ｆａｓ－ＦａｓＬ在肾脏损务中的作用。方法：常规方法分离，培养人肾小球系膜细胞，并传代鉴定，用不同浓度的抗Ｆａｓ抗体刺激４－６代Ｍｃｓ１６ｈ后，荧光染色观察Ｍｃｓ凋亡变化，二苯胺法和ＤＮＡ凝胶电泳方法定量和定性分析ＭｃｓＤＮＡ片段化变化。     

白血病中Fas/FasL系统诱导的细胞凋亡作用

Fas FasL系统是研究最深入的介导细胞凋亡的途径 ,当Fas与FasL结合时 ,可直接引起Fas+ 细胞的凋亡。但是在白血病的发病过程中 ,尽管高表达Fas,似乎仍存在着血细胞的凋亡不足。许多研究表明 ,白血病细胞对Fas FasL途径介导的凋亡不敏感或存在抵抗也是导致白血病耐药的原因之一 ,白血病的Fas抗性与多种因素有关 ,对它们的研究可为白血病的治疗提供新的方法     

First trimester trophoblast cells secrete Fas ligand which induces immune cell apoptosis

Since the invading trophoblast represents a semi-allograft, it should be rejected by the mother. It has, therefore, been postulated that during normal pregnancy the trophoblast evades the maternal immune system though the establishment of immune privilege by triggering the death of activated lymphocytes which may be sensitized to paternal alloantigens. Such peripheral tolerance may be directed through the Fas/Fas ligand (FasL) apoptotic pathway and mediated by FasL expressed by the trophoblast. However, in vivo studies show that membrane-associated expression of FasL may instead promote allograft rejection, rather than protection. The aim of this study was to determine if there is a role for FasL in trophoblast immune privilege. In this study, we demonstrate that isolated first trimester trophoblast cells lack membrane-associated FasL, but express a cytoplasmic form in association with a specialized secretory lysosomal pathway. Furthermore, this intracellular FasL is constitutively secreted by trophoblast cells via the release of microvesicles. Following disruption of these microvesicles, the whole 37 kDa secreted FasL is able to induce T-cell death by apoptosis through activation of the Fas pathway. Therefore, we propose that secretion of FasL may be one mechanism by which trophoblast cells promote a state of immune privilege and, therefore, protect themselves from maternal immune recognition.     

特异性ASODN抑制Fas表达降低FasL介导细胞凋亡的研究

为了研究特异性Fas反义寡核苷酸(ASODN)对T细胞Fas表达及肝癌细胞诱导其凋亡的抑制作用,用脂质体介导法将Fas ASODN导入Jurkat T细胞,并通过用流式细胞术、RT-PCR及与肝癌细胞共培养方法研究Fas ASODN对T细胞Fas表达、Fas mRNA水平及凋亡的影响。结果显示:①Hep G2.2.15细胞表达有功能的FasL,可诱导Jurkat细胞凋亡;②Jurkat细胞转染Fas ASODN后,Fas mRNA降低;细胞表面Fas表达下降;与Hep G2.2.15细胞共培养后的凋亡率下降。表明Fas ASODN转染可以部分逆转肝癌细胞对T细胞的凋亡诱导作用。     

The anabolic benefits of venous blood flow restriction training may be induced by muscle cell swelling

Venous blood flow restriction (VBFR) combined with low intensity resistance exercise (20-30% concentric 1-RM) has been observed to result in skeletal muscle hypertrophy, increased strength, and increased endurance. Knowledge of the mechanisms behind the benefits seen with VBFR is incomplete, but the benefits have traditionally been thought to occur from the decreased oxygen and accumulation of metabolites. Although many of the proposed mechanisms appear valid and are likely true with VBFR combined with resistance exercise, there are certain situations in which benefits are observed without a large accumulation of metabolites and/or large increases in fast twitch fiber type recruitment. Cell swelling appears to be a likely mechanism that appears to be present throughout all studies. VBFR may be able to induce cell swelling through a combination of blood pooling, accumulation of metabolites, and reactive hyperemia following the removal of VBFR which may contribute to skeletal muscle adaptations that occur with VBFR. We hypothesize that cell swelling is important for muscle growth and strength adaptation but when coupled with higher metabolic accumulation, this adaptation is even greater.     

Fas／FasL在超抗原SEA诱导T细胞凋亡中的作用

目的超抗原能诱导 T细胞凋亡 ,但其作用机制尚未阐明 ,Fas系统与 Ca2 在其中的作用尚待进一步研究。方法超抗原金黄色葡萄球菌肠毒素 A(SEA)诱导人外周血建立的短期 SEA反应 T细胞系凋亡 ,1.8%琼脂糖凝胶 DNA电泳于不同时间观察凋亡的特征条带 ;FCM检测 Fas、Fas L 的表达量变化 ,Fura- 2 / AM荧光指示剂检测胞浆游离 [Ca2 ]i的变化。结果使用 FCM特异性检测凋亡亚 G0 / G1峰大小及 1.8%琼脂糖凝胶电泳检测凋亡 DNA梯状图谱证明 ,SEA能诱导短期 SEA反应 T细胞凋亡 ,其凋亡的时间与程度与 SEA的剂量有关。SEA1μg/ ml建立的短期 SEA反应 T细胞对 SEA1μg/ml的再次刺激 ,凋亡量随作用时间的延长而增多 ,在作用的第 16 h最高 ,达 5 8%。 FCM间接荧光染色法检测发现 ,Fas及Fas L 亦随 SEA作用时间的延长而表达增多 ,16 h时表达最多 ,分别为 92 %和 6 0 %。用 Fura- 2 / AM荧光指示剂检测 ,此时细胞胞浆 [Ca2 ]i已从刺激前的 (2 90± 33) nm ol/ L 上升到 (6 80± 16 ) nmol/ L。结论 Fas系统与 SEA诱导的 T细胞凋亡密切相关。换言之 ,Fas系统在超抗原诱导 T细胞凋亡中起作用 ,而胞浆 [Ca2 ]i升高与 SEA诱导的凋亡 T细胞 DNA断裂及其它凋亡形态变化有关。     

CEACAM1 (CD66a) mediates delay of spontaneous and Fas ligand-induced apoptosis in granulocytes

Granulocytes form the first and fastest line of defense against pathogenic infections. Their survival is limited by apoptosis, a process that is critical for the resolution of inflammation. Pro-apoptotic and pro-inflammatory cytokines, as well as several receptors, can alter the lifespan of granulocytes. Here we report that the carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1, CD66a) is involved in the regulation of granulocyte survival. Until now CEACAM1 is described to control cell proliferation, cell migration, tumor growth, angiogenesis and diverse leukocyte functions. However, very little is known about its role in granulocytes. We found that CEACAM1 expression in resting rat granulocytes is significantly higher than in other leukocyte subtypes. Stimulation led to a strongly increased CEACAM1 cell surface expression and to release of soluble CEACAM1. DNA fragmentation assays and annexin V staining revealed that binding of CEACAM1-specific antibodies, Fab fragments and soluble CEACAM1-Fc constructs to cell surface-expressed CEACAM1 causes a delay of spontaneous and Fas ligand (CD95L)-induced apoptosis. Tyrosine phosphorylation of CEACAM1-L, its association with SHP-1, the activation of Erk1/2 and caspase-3 appeared to be crucial for the CEACAM1-mediated anti-apoptotic effect. These findings provide evidence that CEACAM1 influences the resolution of inflammation by prolonging the survival of rat granulocytes.