Noxa在凋亡中的作用及机制

Noxa是内源性途径凋亡中Bc l-2家族促凋亡的BH3-on ly亚家族成员之一,在诱导细胞凋亡中起重要作用。它通过定位于线粒体,引起线粒体释放细胞色素C以形成凋亡体,启动caspase级联反应而诱导细胞发生凋亡。Noxa的表达主要受p53调控,但是多种刺激因子可以通过p53或者不依赖p53等多种途径诱导Noxa表达上调,最后由Noxa来诱导细胞发生凋亡。     

线粒体在细胞凋亡中的作用及分子机制

本文综述了线粒体在细胞凋亡的启动和调控方面的最新进展。细胞受凋亡刺激，Bcl-2家族BH3蛋白(Bim，Bad，Bid等)和其他可能的途径将凋亡信号转入线粒体中，与Bcl-2家族凋亡诱导蛋白共同调节，诱导释放线粒体凋亡蛋白细胞色素c、caspase的二级线粒体激活蛋白Smac、凋亡诱导蛋白、内核酸酶G和Omi/HtrA2等，进而通过caspase依赖途径和非依赖途径诱导细胞凋亡。     

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。     

p53,Bcl-2,Caspases在一氧化氮诱导凋亡的信号传递机制中作用的研究进展

一氧化氮 (NO)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作简要介绍。     

Bcl-2基因家族在调节细胞凋亡中的作用

Bcl-2基因家族包含抑制和促进细胞凋亡两类功能相反的蛋白质,在细胞凋亡中发挥重要的调节作用。本文结合近年来的研究进展,综述了Bcl-2基因家族中两类蛋白质分子的结构特征、亚细胞分布、相互间的作用方式以及与它们发挥功能的关系,为认识细胞凋亡中复杂的分子调控机制,寻找凋亡紊乱相关疾病中可资利用的药物干预靶点提供了重要启示。     

p53与细胞凋亡

细胞增殖周期分四个阶段，ＤＮＡ合成前期（Ｇ１期）到ＤＮＡ合成期（Ｓ期）受一系列基因调节。这些基因包括具有起促进作用的基因和起抑制作用的基因，二者作用的平衡维持细胞增殖的正常状态。当具有启动作用的基因表达增强或具有抑制作用的基因（如ｐ５３）因缺失突变所...     

细胞凋亡中的钙调节

胞质Ca2 + 升高是细胞凋亡中Ca2 + 调节的经典模式 ,但近年来有证据表明胞质Ca2 + 下降同样能诱导细胞凋亡。目前研究发现 ,胞内Ca2 + 在细胞质、细胞核以及细胞钙库线粒体和内质网的动态平衡破坏和重新分布直接参与细胞凋亡信号的调控 ,而Bcl 2家族蛋白在细胞凋亡过程的胞内Ca2 + 调节及继后的一系列生理效应中发挥特殊作用。细胞凋亡中Ca2 + 调节的深入研究不但有助于阐明细胞凋亡的调控机理 ,同时为相关疾病防治和药物开发提供新的策略     

实验性隐睾诱导小鼠生精细胞凋亡的研究

目的 研究手术隐睾所致成年小鼠生殖细胞凋亡及相关调节因子ｂｃｌ－２、ｂａｘ蛋白在曲细精管中的定位、变化。方法 以末端脱氧核糖核酸转移酶介导的ｄＵＴＰ缺口末端标记法（ＴＵＮＥＬ）检测凋亡的生殖细胞,生物素－抗生物素蛋白ＤＣＳ体系间接免疫荧光法检测Ｂｃｌ－２、Ｂａｘ蛋白在曲细精管中的定位、分布。结果 隐睾术后３ｄ,手术侧睾丸重量及细胞凋亡数量与对侧地无明显区别。而６￣１５ｄ,睾丸重量明显减轻,凋亡细胞     

氧化苦参碱对人卵巢癌HO-8910细胞的作用及其机制的初步研究

目的探讨氧化苦参碱（Oxymatrine,OM）在体外诱导人卵巢癌HO-8910细胞的凋亡作用及其可能的机制。方法以不同浓度的OM作用于人卵巢癌HO-8910细胞,应用MTT法检测细胞生长情况;荧光染色观察细胞核的形态学改变;琼脂糖凝胶电泳分析细胞DNA变化;Western blot检测细胞Bcl-2和Bax的蛋白表达情况。结果 OM能显著抑制HO-8910细胞的增殖作用,具有浓度和时间依赖性。荧光染色后可观察到典型的凋亡小体。细胞DNA电泳后呈现出凋亡细胞典型的DNA ladder。Bcl-2蛋白表达量逐渐降低,Bax蛋白表达量逐渐增加,呈明显的浓度依赖性。结论 OM能诱导体外培养的人肝癌HO-8910细胞凋亡。Bcl-2表达增多,Bax表达减少是OM诱导HO-8910细胞凋亡的可能机制之一。     

震动伤引起的家犬外周血淋巴细胞凋亡及其机制

应用免疫细胞化学和酶细胞化学技术，观察了震动伤引起的家犬外周血淋巴细胞凋亡，Ｔ淋巴细胞数的变化及其发生机制。结果表明，实验所用２００、１００和８０三种垂直加速度值（Ｇ）在致伤后不同时间，均可引起淋巴细胞的凋亡，其凋亡率随Ｇ值增加而增大；观察伤后不同时间细胞凋亡的变化，发现在伤后３ｄ其凋亡率达到峰值，约为伤前的５～８倍；而外周血Ｔ淋巴细胞数在伤后明显降低，与凋亡呈现出相反的变化趋势；还发现伤后３ｄ与凋亡相关的ｐ５３和Ｂａｘ蛋白阳性率分别为伤前值的２．３和１．８倍，二者在诱发淋巴细胞凋亡中可能起着重要作用。     

Apoptosis induced by paclitaxel via Bcl-2, Bax and caspases 3 and 9 activation in NB4 human leukaemia cells is not modulated by ERK inhibition

We have studied the role of pivotal bio-molecules involved in signalling of cytotoxic effects induced by paclitaxel (Ptx) on acute promyelocytic human leukaemia NB4 cells. A time-dependent increase in cell death and DNA cleavage was observed after 30 μM Ptx treatment. Cell death induction by Ptx proceeds mainly as programmed cell death as shown by annexin V-FITC, reaching up to 30% of apoptotic cells after 24 h. Significant reductions of p53, changes in Bax and Bcl-2 and activation of caspases 3 and 9 were observed as the treatment was applied for long times. Ptx treatments produced NFkB depletion with expression levels abolished at 19 h what could be involved in reduction of survival signals. Phosphorylation of intracellular kinases showed that pERK1/2 decreased significantly at 19 h of Ptx treatment. When these cells were preincubated for 90 min with 20 μM PD98059, 2′-amino-3′-methoxyflavone, an inhibitor of ERK phosphorylation, a slight reduction of cell viability was observed in comparison to that produced by Ptx alone. Pretreatment with PD98059 neither activated caspases nor significantly increased the apoptotic effect of Ptx. Taken together, our data reveal that the inhibition of ERK phosphorylation does not seem to be an essential pathway for bursting an increased induction of apoptosis by Ptx. Decrease of p53 and Bcl-2, fragmentation of DNA, increase of Bax and, finally, activation of caspases 3 and 9 in NB4 leukaemia cells make the apoptotic process induced by Ptx irreversible. Application of Ptx in leukaemia cells shows therefore a promising potential with particular effects on different leukaemia cell types.     

Mechanism of perfluorooctanesulfonate (PFOS)-induced apoptosis in the immunocyte

As a new type of persistent organic pollutant, perfluorooctane sulfonate (PFOS) has raised great concern in recent years due to its ubiquitous distribution in the general environment and its long elimination half-life in humans. PFOS has toxic and carcinogenic effects in animals and humans, but the effects of PFOS on apoptosis are still not clear. The present study aimed to determine the mode of cell death and its mechanism in splenocytes and thymocytes from adult male C57BL/6 mice administered 0, 1, 5, or 10 mg PFOS/kg/day by gavage daily for 7 days. The results showed that more apoptotic cells were present in PFOS-treated mice than in control mice. PFOS induced production of reactive oxygen species (ROS), dissipation of mitochondria membrane potential, and apoptosis of splenocytes and thymocytes. Moreover, activities of superoxide dismutase, catalase, and glutathione reductase were increased, whereas activities of glutathione-S-transferase and glutathione peroxidase were decreased, in splenocytes. Glutathione contents were reduced as well. Differential expressions of proteins such as p53, Bax, caspase-3, and caspase-9 were significantly up-regulated in PFOS-exposed hosts, whereas Bcl-2 expression was significantly down-regulated. One possible mechanism for the findings here was that PFOS could overwhelm homeostasis of anti-oxidative systems, boost ROS generation, impact on mitochondria, and affect protein expression of apoptotic regulators, the latter of which resulted in initiation of the apoptosis program. Results from this study may provide a new insight into the potential adverse effects of PFOS exposure on humans, at the cellular level.     

中药髓复康对恒河猴脊髓半横断后凋亡相关蛋白表达的影响

目的:探讨中药髓复康(SFK)对恒河猴脊髓半横断后凋亡相关蛋白(Bcl-2、Bax和p53)表达的作用及其机理。方法:实验选用8岁恒河猴14只,随机分为中药治疗组6只、横段脊髓模型组6只、正常对照组2只,采用双盲法复制脊髓T12右侧半横断损伤模型。灌喂SFK溶液1月后,实验恒河猴麻醉、以损伤部位为中心切取长1cm的脊髓,采用常规SABC免疫组织化学方法检测凋亡相关基因Bcl-2、Bax和p53蛋白表达,并对结果进行定性、定位、图像分析和统计学处理。结果:脊髓Bax免疫组织化学阳性细胞的平均光密度(MOD)模型组略高于正常对照组,中药组明显低于模型组(P0.05)。脊髓Bcl-2免疫组织化学阳性细胞面数密度(NA),中药组明显高于模型组(P0.05)。脊髓Bcl-2免疫组织化学阳性细胞的MOD模型组略高于正常对照组,中药组略高于模型组。脊髓p53免疫组织化学阳性细胞NA,模型组明显高于正常对照组(P0.05),中药组明显低于模型组(P0.05)。脊髓p53免疫组织化学阳性细胞的MOD模型组明显高于正常对照组(P0.05),中药组明显低于模型组(P0.05)。结论:髓复康可以促进Bcl-2蛋白表达,抑制Bax、p53蛋白表达和抑制神经元凋亡,对脊髓神经损伤具有保护作用。     

Apoptosis and apoptotic-related factors in mucoepidermoid carcinoma of the oral minor salivary glands

The oncoproteins Bcl-2 and Bax, the tumor suppressor gene product p53, TUNEL (TdT [terminal deoxynucleotidyl transferase] dUTP nick end-labeling) and the cell-cycle antigen Ki-67 were studied in 71 cases of mucoepidermoid carcinoma originating in the oral minor salivary glands. Grade I tumors had higher expression of Bcl-2 than Grade II and III tumors (chi2 test, 0.01相似文献   

黄芪注射液对缺氧缺糖/复氧复糖大鼠海马神经元Bcl-2和Bax表达的影响

目的: 观察黄芪注射液对缺氧缺糖/复氧复糖大鼠海马神经元凋亡相关蛋白Bcl-2、Bax及其mRNA表达的影响。方法: 取原代培养8 d的大鼠海马神经元,随机分为4组:正常对照组、模型组(缺氧缺糖/复氧复糖组)、溶剂对照组(缺氧缺糖/复氧复糖+黄芪注射液溶剂处理组)和黄芪注射液处理组(缺氧缺糖/复氧复糖+黄芪注射液处理组)。除正常对照组外,各组均进行缺糖缺氧0.5 h,再分别于复氧复糖后0 h、0.5 h、2 h、6 h、24 h、72 h和120 h采用Western blotting法检测海马神经元Bcl-2和Bax蛋白的表达,RT-PCR法检测海马神经元bcl-2和bax mRNA的表达。结果: Western blotting结果显示:与正常对照组比,模型组Bcl-2和Bax蛋白表达明显升高,而Bcl-2/Bax比值下调(P<0.05);与模型组比,黄芪注射液处理组Bcl-2蛋白表达升高,Bax蛋白表达明显降低,Bcl-2/Bax比值升高( P<0.05),而溶剂对照组Bcl-2、Bax蛋白表达及Bcl-2/Bax比值则无显著变化(P>0.05)。bcl-2 mRNA、bax mRNA表达趋势同蛋白。结论: 黄芪注射液可提高缺氧缺糖/复氧复糖大鼠海马神经元Bcl-2表达及Bcl-2/Bax比值,抑制Bax表达,从而抑制缺氧缺糖/复氧复糖引起的海马神经元凋亡。     

甲状腺激素缺乏对大鼠胸腺细胞凋亡的影响

目的:探讨甲状腺激素缺乏对大鼠胸腺细胞凋亡及其相关蛋白Bcl-2和Bax表达的影响.方法:采用放射免疫技术测定甲巯咪唑组仔鼠血清中三碘甲状腺原氨酸(T3)、四碘甲状腺原氨酸(T4)、促甲状腺激素(TSH)水平;应用光镜、透射电镜技术和共聚焦激光扫描显微镜观察胸腺组织细胞形态学改变;免疫组织化学法检测胸腺组织中Bcl-2和Bax蛋白的表达.结果:甲巯咪唑组仔鼠体小,行动迟缓,胸腺绝对质量明显低于对照组,差异有统计学意义.对照组大鼠血清中T3、 T4值均高于甲巯咪唑组,TSH值低于甲巯咪唑组.甲巯咪唑组胸腺组织中出现大量的凋亡细胞和凋亡小体.Bcl-2蛋白表达的平均光密度值低于对照组;胸腺组织中Bax蛋白表达的平均光密度值高于对照组.结论:甲状腺激素缺乏可抑制胸腺组织中Bcl-2蛋白的表达和促进Bax蛋白的表达,诱导大鼠胸腺细胞凋亡,促进胸腺退化.     

Apoptosis of colorectal adenocarcinoma (COLO 201) by tumour necrosis factor-alpha (TNF-α) and/or interferon-gamma (IFN-γ), resulting from down-modulation of Bcl-2 expression

Fas antigen is constitutively expressed in the normal colon epithelium, but considerably diminished in most colorectal carcinomas. In the present study, we examine the relationship between Fas antigen expression and apoptosis using the colorectal carcinoma cell line COLO 201, on which a low grade of Fas antigen is expressed. Anti-Fas antibody had no effect on the induction of apoptosis of COLO 201. However, TNF-α and/or IFN-γ, independently and additively, up-regulated Fas antigen expression on COLO 201 and induced apoptosis in a dose-dependent manner. Both cytokines also increased the COLO 201 sensitivity to anti-Fas antibody, resulting from the down-modulation of Bcl-2 and the up-regulation of Bax. These findings indicate that cytokine(s) plus anti-Fas antibody (which mimics natural Fas ligand) are more effective in inducing apoptosis of COLO 201 than cytokine(s) alone. These findings suggest that immunotherapy in combination with cytokine(s) and lymphokine-activated killer (LAK) cells will become a more effective therapy for cancer than cytokine(s) or LAK cells alone, since the Fas ligand is expressed on activated T cells, natural killer cells and macrophages.     

Effects of transient focal cerebral ischemia in mice deficient in puma

Bcl-2 homology domain 3 (BH3)-only pro-apoptotic proteins may play an important role in upstream cell death signaling pathways underlying ischemic brain injury. Puma is a potent BH3-only protein that can be induced via p53, FoxO3a and endoplasmic reticulum stress pathways and is upregulated by global cerebral ischemia. To more completely define the contribution of Puma to ischemic brain injury we measured the expressional response of Puma to transient focal cerebral ischemia in mice and also compared infarct volumes in puma-deficient versus puma-expressing mice. Real-time quantitative PCR determined puma mRNA levels were significantly increased 8 h after 90 min middle cerebral artery (MCA) occlusion in the ipsilateral cortex, while expression remained unchanged contralaterally. Puma protein levels were also increased in the ischemic cortex over the same period. However, cortical and striatal infarct volumes were not significantly different between puma-deficient and puma-expressing mice at 24 h, and no differences between genotypes were found for post-ischemic neurological deficit scores. These data demonstrate that focal cerebral ischemia is associated with puma induction but suggest that Puma does not contribute significantly to lesion development in the present model.     

Quantification of Bax/Bcl-2 ratios in peripheral blood lymphocytes, monocytes and granulocytes and their relation to susceptibility to anti-Fas (anti-CD95)-induced apoptosis

Neutrophils have the shortest half-life among circulating leucocytes and rapidly undergo apoptosis in vitro. The homologous Bcl-2 and Bax proteins have opposing effects, with Bcl-2 extending cellular survival and Bax promoting cell death following an apoptotic stimulus. We determined Bcl-2 to Bax expression ratios in peripheral blood lymphocytes, monocytes and granulocytes and related them to the susceptibility of these cells to anti-Fas (anti-CD95)-induced apoptosis. Here, we show that Bax/Bcl-2 ratios are high in granulocytes and relatively low in monocytes and lymphocytes. Furthermore, we show a relation between this ratio in the different leucocyte subsets and their susceptibility to anti-Fas-induced apoptosis, with granulocytes showing the highest susceptibility, followed by monocytes and lymphocytes. It is concluded that the balance between Bcl-2 and Bax forms an apoptotic rheostat, which seems to determine sensitivity to apoptosis.     

非小细胞肺癌中survivin上调与p53和Bcl-2的临床病理相关性

目的: 通过回顾性分析87例非小细胞肺癌(NSCLC)的临床病理资料,探索survivin、 p53和Bcl-2的临床病理相关性以及联合检测提示NSCLC预后的可能性.方法: 采用免疫组化SP法检测NSCLC中survivin、 p53和Bcl-2的表达.用Spearman等级相关系数检验其与NSCLC发生的相关性.结果: NSCLC组织的survivin蛋白阳性表达率为55.2%(48/87),阳性表达主要定位于NSCLC细胞质中.不同分期的NSCLC在survivin阳性表达率方面存在显著差异: III和IV期(中晚期)病例阳性率为71.1%(32/45),而I和II期(早中期)阳性率则为38.1%(16/42,P<0.01).不同原发肿瘤分期病例未显示出差异性survivin表达;而survivin表达则具有显著N分期相关性,无淋巴结转移(N0)病例的阳性率为43.5%(27/62),有淋巴结转移(N1和N2)病例则为84.0%(21/25,P<0.01).Survivin在鳞癌和腺癌中表达率分别为76.0%(38/50)和27.0%(10/37),其表达在两种病理类型间存在统计学差异(P<0.01).NSCLC组织的p53蛋白阳性表达率为64. 6%(56/87),阳性表达产物主要定位于NSCLC细胞质中.有淋巴结转移(N1和N2)病例阳性率(84.0%,21/25)显著高于无淋巴结转移病例(54.8%) (34/62,P<0.01).而且p53表达同时还具有组织类型相关性,鳞癌病例阳性率(76.0%,38/50)显著高于腺癌病例(27.0%) (10/37,P<0.01).NSCLC组织的Bcl-2蛋白阳性表达率为56.3%(49/87),阳性表达产物定位于NSCLC细胞质和细胞核中.有淋巴结转移(N1-2)病例阳性率(48.0%,12/25)明显高于无淋巴结转移病例(22.6%) (14/62,P<0.01).结论: Survivin上调显示出与NSCLC的临床病理相关性,同时survivin与p53和Bcl-2在NSCLC中也具有一定的临床病理相关性.[