墨旱莲对小鼠胸腺细胞凋亡的调节作用

目的:以环磷酰胺(CY)诱导的小鼠胸腺细胞凋亡为模型,研究中药墨旱莲(EcliptaProstrataL)对胸腺细胞凋亡的调节作用。方法:小鼠腹腔注射CY,建立胸腺细胞凋亡模型,同时用墨旱莲灌胃进行治疗。应用电镜、DNA琼脂糖凝胶电泳、流式细胞仪、TDT缺口末端标记法(TUNEL)等方法,研究墨旱莲在活体内对小鼠胸腺细胞凋亡的影响。结果:电镜、DNA琼脂糖凝胶电泳显示环磷酰胺组出现典型的细胞凋亡表现,墨旱莲组较环磷酰胺组有一定程度的改善,流式细胞仪、TDT缺口末端标记法(TUNEL)分析显示墨旱莲组能降低胸腺细胞凋亡率,减轻CY所致的DNA损伤。结论:墨旱莲能不同程度抑制CY诱导的小鼠胸腺细胞凋亡。     

鱼藤酮诱导PC12细胞凋亡及线粒体膜电位变化

目的探讨鱼藤酮对大鼠PC12细胞的毒性作用及可能机制。方法将培养的PC12细胞分为正常对照组、鱼藤酮50、100、500、1 000、2 000 nmol·L-1组,分别用MTT比色法检测细胞存活率,Hoechst 33258染色观察细胞核形态及凋亡比例,免疫组织化学法检测α-突触核蛋白(ɑ-synuclein)的表达,JC-1染色检测线粒体膜电位变化。结果 MTT检测发现,与正常对照组相比,鱼藤酮50、100、500、1 000、2 000nmol·L-1组细胞存活率下降(P<0.05),分别为(83.0±9.3)%、(79.5±11.8)%、(41.0±7.0)%、(26.4±5)%、(10.2±3.5)%。Hoechst 33258染色发现,鱼藤酮组细胞核固缩、裂解;与正常组比较,鱼藤酮组细胞凋亡率分别增加了6%,21%,64%,80%,89%,差异具有统计学意义(P<0.05)。免疫组化检测ɑ-synuclein结果显示,鱼藤酮组细胞出现ɑ-synuclein聚集,部分形成球状包涵体。鱼藤酮50、100、500、1 000、2 000 nmol·L-1组线粒体膜电位的红/绿荧光强度比值分别为1.21±0.13、0.85±0.1、0.32±0.18、0.25±0.09、0.18±0.04,明显低于正常对照组1.92±0.15,差异具有统计学意义(n=3,P<0.01)。结论鱼藤酮对PC12细胞具有毒性作用,可诱导细胞凋亡和ɑ-synuclein聚集,其机制可能与降低线粒体膜电位有关。     

头孢地秦和阿米卡星治疗肺炎克雷伯氏菌感染对小鼠胸腺细胞凋亡的影响

目的研究肺炎克雷伯氏菌感染及应用头孢地秦、阿米卡星治疗后对NIH小鼠胸腺细胞凋亡的影响。方法给NIH小鼠腹腔注射肺炎克雷伯氏菌悬液,建立肺炎克雷伯氏菌感染模型。TUNEL法染色后用流式细胞仪观察24h内胸腺细胞的凋亡量。腹腔注射不同剂量的头孢地秦和阿米卡星,观察注射后9h胸腺细胞的凋亡量。结果胸腺细胞凋亡在感染后逐渐增高,至24h达高峰(P<0.01)。与感染组相比,头孢地秦5、15mg组的凋亡率分别下降56%、81%,两组比较有显著性差异(P<0.05)。阿米卡星5、15mg组的凋亡率分别下降41%、76%,两组比较也有显著性差异(P<0.05)。结论肺炎克雷伯氏菌感染能引起胸腺细胞发生凋亡,应用头孢地秦和阿米卡星能明显抑制胸腺细胞的凋亡。     

低剂量γ射线诱导丝裂霉素C损伤小鼠胸腺细胞的适应性反应

目的 :探讨低剂量辐射诱导小鼠拮抗丝裂霉素C(MitomycinC,MMC)损伤作用的机制。方法 :小鼠接受低剂量γ射线作用后6h ,再给予损伤剂量的MMC ,然后通过流式细胞术和 3H_TdR掺入法观察小鼠胸腺细胞周期和DNA含量的变化。结果 :50mGy和100mGy照射加MMC组小鼠胸腺细胞 3H_TdR自发掺入率、S期细胞百分率明显高于单纯MMC对照组 (P<0.01,P<0.05)。胸腺细胞G0/G1 期细胞百分率明显低于单纯MMC对照组 ,100mGy照射加MMC组小鼠胸腺细胞G2/M期细胞百分率明显低于单纯MMC对照组。结论 :低剂量γ射线对MMC损伤小鼠胸腺细胞自发掺入能力和细胞周期进程具有刺激作用。     

神经酰胺诱导结肠癌HT-29细胞凋亡与线粒体膜电位变化的关系

目的 探索神经酰胺(C2-ceramide,C2-cer)对人结肠癌HT-29细胞增殖、线粒体膜电位改变、细胞凋亡等的影响.方法 正常培养的HT-29细胞分为C2-cer处理组与非处理组,用MTT法、流式细胞仪等方法观察不同时间C2-cer对细胞增殖、线粒体膜电位改变、细胞凋亡等的影响.结果 加入C2-cer可引起HT-29细胞线粒体膜电位 (△Ψm)下降,细胞增殖受抑,并导致细胞凋亡.上述效应与C2-cer剂量以及作用时间相关.结论 C2-cer可导致HT-29细胞线粒体膜电位(△Ψm)下降,抑制细胞增殖,诱导细胞凋亡.     

辛伐他汀诱导K562细胞凋亡过程中对线粒体膜电位的影响

目的:观察辛伐他汀诱导人红白血病K562细胞凋亡时线粒体膜电位(Δψm)的变化及其与时间的关系。方法:常规培养细胞24h,辛伐他汀(20μmol.L-1)处理K562细胞12、24、48、72h,观测细胞形态学改变;MTT法检测细胞增殖抑制情况;流式细胞术检测细胞凋亡率和线粒体膜电位改变,并与溶剂对照组比较。结果:与对照组比较,辛伐他汀作用K562细胞48h后细胞出现核固缩、核碎裂和凋亡小体等形态学改变;作用12、24、48、72h后细胞凋亡率分别增加(2.55±0.35)%、(6.1±0.35)%、(14.15±0.42)%、(30.70±0.65)%,K562细胞凋亡率随着药物作用时间延长而增加;细胞膜电位降低百分率分别为(0.7±0.24)%、(39.6±4.80)%、(24.4±2.45)%、(6.0±1.62)%,24h时膜电位降低百分率最大。结论:线粒体跨膜电位降低是凋亡发生的早期事件,辛伐他汀诱导K562细胞凋亡的可能机制是通过使线粒体跨膜电位崩溃,从而导致细胞凋亡。     

顺铂诱导胃癌SGC-7901细胞凋亡作用及其对线粒体膜电位变化的研究

目的研究线粒体膜电位在顺铂诱导胃癌细胞凋亡中的作用机制。方法采用MTT比色法测定顺铂对胃癌SGC7901细胞的生长抑制曲线;将胃癌SGC7901细胞分成对照组及10μg/ml顺铂组处理,用流式细胞仪（FCS）分别检测线粒体膜电位（Δψm）和分析细胞周期变化情况。结果顺铂可明显抑制胃癌细胞增殖。在24h后可见细胞大部分受阻于G1期,且出现了典型的凋亡峰;在10h后线粒体膜电位明显降低。结论顺铂诱导胃癌SGC-7901细胞凋亡的途径可能是通过使线粒体膜通透性的改变,膜电位的下降来而实现的。     

线粒体与细胞凋亡的研究进展

细胞凋亡 (apoptosis)是一种普遍的生理现象 ,是指在一定的生理或病理条件下 ,按程序进行的细胞死亡过程 ,亦称程序性细胞死亡 (programmedcelldeath ,PCD) ,对于维持多细胞机体的完整性和自身稳态具有重要作用。线粒体是所有真核细胞内腺苷三磷酸(ATP)产生中心 ,对维持细胞能量代谢和正常功能活动起重要作用。新近研究发现 ,线粒体内包含一些与细胞凋亡有密切关系的物质 ,如细胞色素C(CytC、凋亡诱导因子 (AIF)、Ca2 + 和活性氧自由基 (ROS)等。在凋亡信号的刺激下 ,线粒体膜通透性增加 ,由此产生一系列关键性变化 ,包括CytC的释放…     

辛伐他汀通过线粒体途径诱导K562细胞凋亡

目的观察辛伐他汀诱导K562细胞凋亡不同时间的膜电位(Δψm),caspase-3、9和细胞色素C的改变,以推测其凋亡通路。方法采用浓度为20μmol.L-1的辛伐他汀处理K562细胞24、48、72 h,采用流式细胞技术检测细胞凋亡率和线粒体膜电位,分光光度法检测caspase-3、9蛋白活性,免疫组织化学法检测细胞色素C蛋白。结果浓度为20μmol.L-1辛伐他汀作用K562细胞24、48、72 h后,凋亡率分别为(6.1±0.35)%、(14.15±0.42)%(、30.70±0.65)%,随着凋亡率增加线粒体膜电位降低分别为(39.6±4.80)%,(24.4±2.45)%,(6.0±1.62)%;caspase-3、9蛋白活性与对照组相比上调,细胞浆内细胞色素C升高。结论辛伐他汀诱导K562细胞凋亡时线粒体膜电位下降,caspase-3、9活性增高和细胞色素C释放,推测辛伐他汀诱导K562细胞的凋亡可能经过线粒体凋亡途径。     

Genomic and non-genomic effects of different glucocorticoids on mouse thymocyte apoptosis

Glucocorticoids, widely used therapeutic agents for several pathologies, act upon diverse cells and tissues, including the lympho-haemopoietic system. Glucocorticoid-mediated apoptosis has been described as one of the mechanisms underlying their pharmacological and physiological effects. Glucocorticoids induce apoptosis in thymocytes through genomic and non-genomic signals. We tested thymocyte apoptosis rates as induced by a panel of glucocorticoids. Using four glucocorticoids that are widely adopted in clinical practice we compared their induction of thymocyte apoptosis and activation of non-genomic and genomic signals, including phosphatidylinositol-specific phospholipase C (PI-PLC), caspase-8, -9 and -3, and Glucocorticoid-Induced Leucine Zipper (GILZ). GILZ is a protein that is rapidly induced by glucocorticoids treatment and involved in apoptosis modulation. Results indicate different glucocorticoids have different apoptotic activity which is related to their ability to induce both genomic, evaluated as caspases activation and GILZ expression, and non-genomic effects, evaluated as PI-PLC phosphorylation.     

Benzodiazepine receptor agonists modulate thymocyte apoptosis through reduction of the mitochondrial transmembrane potential

Peripheral-type benzodiazepines have been shown to exert immunological effects. In this study, we examined the effects of the peripheral-type benzodiazepines on murine thymocytes. Murine thymocytes that were incubated with the peripheral-type benzodiazepines underwent apoptosis associated with the collapse of mitochondrial transmembrane potential (delta psi(m)). The drugs stimulated dexamethasone- and etoposide-induced apoptosis with the enhanced collapse of delta psi(m). The central-type benzodiazepines had no effect on either the delta psi(m) or apoptosis. The reduction of delta psi(m) depended on protein synthesis and protein phosphorylation. These results suggest that the immunomodulating effect of benzodiazepines is in part due to the modulation of thymocyte apoptosis associated with the collapse of delta psi(m).     

Activation of c-Jun N-terminal kinase is essential for mitochondrial membrane potential change and apoptosis induced by doxycycline in melanoma cells

Background and purpose:

Tetracyclines were recently found to induce tumour cell death, but the early processes involved in this cytotoxic effect remain unclear.

Experimental approach:

Viability of human and mouse melanoma cells was determined by MTT assay and flow cytometry. Kinase/protein/caspase activation was measured by Western blotting and mitochondrial membrane potential (ΔΨ_m) was analyzed by fluorescence microscopy and flow cytometry.

Key results:

Human and mouse melanoma cells were treated with doxycycline or minocycline but only doxycycline was cytotoxic. This cell death (apoptosis) in A2058 cells involved activation of caspase-3, -7 and -9 and contributed to inhibition, by doxycycline, of matrix metalloproteinase (MMP) activity and migration of these cells. Doxycycline induced intra-cellular reactive oxygen species (ROS) production, apoptosis signal-regulated kinase 1 (ASK1), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) activation at an early stage of treatment and induced mitochondrial cytochrome c release into cytosol and ΔΨ_m change during apoptosis. The JNK inhibitor/small interference RNA inhibited doxycycline-induced JNK activation, ΔΨ_m change and apoptosis, but did not affect ASK1 activation, suggesting a role of ASK1 for JNK activation in melanoma cell apoptosis. Two ROS scavengers reduced doxycycline-induced JNK and caspase activation, and apoptosis. Taken together, the results suggest the involvement of a ROS-ASK1-JNK pathway in doxycycline-induced melanoma cell apoptosis.

Conclusions and implications:

We have shown a promising cytotoxic effect of doxycycline on melanoma cells, have identified ROS and ASK1 as the possible initiators and have demonstrated that JNK activation is necessary for doxycycline-induced melanoma cell apoptosis.     

砷诱导的肝癌细胞凋亡及端粒酶活性改变

目的：研究三氧化二砷（As2O3)对肝癌细胞凋亡的诱导作用及其机制。方法：1μmol/L As2O3处理培养的人肝癌HCC－9204细胞48h，用形态学观察、细胞超微结构分析和流式细胞仪检测等方法鉴定细胞凋亡。用噻唑蓝（MTT）比色试验观察蛋白质全盛抑制剂放线菌素D对As2O3凋亡诱导作用的影响。用TRAP－PCR－ELISA法检测As2O3处理前后肝癌细胞端粒酶活性的变化情况。结果：1μmol/L As2O3作用48h后，HCC－9204细胞出现了典型的凋亡形态学改变和超微结构变化；流式细胞仪检测到大量Annexin-阳性、PI－阴性细胞、放线菌素D可明显拮抗As2O3的凋亡诱导作用。细胞凋亡发生后端粒酶活性显著降低，A450/A630值从2．874降为0．767。结论：As2O3可以有效诱导肝癌细胞凋亡，端粒酶活性降低可能是其中的机制之一。     

组织蛋白酶B对自发性高血压大鼠胸腺细胞凋亡的影响(英文)

目的:本实验研究自发性高血压大鼠胸腺机能异常的机制。方法:用原位杂交确定蛋白酶B的表达位置,Northern杂交分析组织蛋白酶B的表达水平,用TUNEL和流式细胞仪分别检测胸腺细胞的凋亡情况。结果:在离体和在体水平,胸腺组织蛋白酶B的表达与胸腺细胞凋亡伴行,在胸腺细胞的胞浆中检测到组织蛋白酶B的转录产物在6周和8周的自发性高血压大鼠胸腺中的表达高于WKY大鼠。结论:自发性高血压大鼠的胸腺细胞凋亡增加,与组织蛋白酶B的表达相关。     

MAPK信号通路对地塞米松抑制Jurkat细胞增殖及诱导凋亡的影响

目的研究丝裂原活化蛋白激酶(MAPK)信号通路对地塞米松(Dexamethasone,DEX)诱导急性淋巴细胞白血病Jurkat细胞凋亡及抑制细胞增殖的影响。方法观察地塞米松、PD98059、SP600125、SB203580及地塞米松分别联合PD98059、SP600125、SB203580对Jurkat细胞增殖及凋亡的抑制作用。以急性淋巴细胞白血病Jurkat细胞为研究对象,应用WST-1法检测细胞的增殖活力;流式细胞术分析细胞凋亡。结果地塞米松对Jurkat细胞24 h和48 h抑制细胞增殖50%的药物浓度(IC50)分别为829、335μM。100μM以上地塞米松以时间、剂量依赖方式抑制Jurkat细胞增殖;地塞米松分别联合PD98059、SP600125可增加对Jurkat细胞增殖的抑制效应,联合SB203580对地塞米松抑制Jurkat细胞增殖无影响。10μM地塞米松联合20μM PD98059可显著增加地塞米松诱导Jurkat细胞凋亡的作用,细胞凋亡率由8.5%升至28.4%。结论急性淋巴细胞白血病Jurkat细胞为糖皮质激素耐药细胞。阻断p38MAPK对地塞米松抑制Jurkat细胞增殖无明显影响。阻断ERK、JNK信号通路均可增强地塞米松对Jurkat细胞的杀伤作用,达到逆转Jurkat细胞对地塞米松的耐药。急性淋巴细胞白血病Jurkat细胞糖皮质激素耐药可能与ERK、JNK通路的活化有关。     

多拉菌素通过线粒体信号通路诱导食管癌细胞凋亡

目的:探讨多拉菌素(doramectin,DRM)在体内、体外对食管癌细胞增殖、凋亡的影响及其作用机制.方法:DRM处理Eca109和EC9706细胞,检测细胞在24,48,72 h存活率;药物处理48 h后,观察两种细胞的细胞形态变化,细胞迁移增殖能力;药物干预48 h后,检测Eca109细胞周期和凋亡的变化,B淋巴...     

阿仑膦酸钠在地塞米松诱导C2C12细胞自噬中的作用机制探讨#br#

摘要：目的　探讨阿仑膦酸钠（ALN）在地塞米松（Dexa）诱导C2C12细胞自噬中的作用及机制。方法　以C2C12细胞为研究对象,设对照组（DMSO处理）,Dexa组（100 μmol/L Dexa处理）,Dexa+ALN组（100 μmol/L Dexa+1.0 μmol/L ALN处理）。分别以0、0.1、0.5、1.0 μmol/L ALN处理C2C12细胞48 h后,采用CCK-8法检测C2C12细胞增殖水平,筛选ALN合适剂量;HE染色法检测C2C12细胞分化;采用Image J统计肌小管直径和融合指数;Western blot检测C2C12细胞肌蛋白肌球蛋白重链（MHC）、肌肉特异性环指蛋白1（MuRF1）和自噬相关蛋白微管相关蛋白1轻链3（LC3）、Beclin-1的表达变化;免疫荧光标记检测C2C12细胞MHC表达水平。结果　选取ALN合适剂量1.0 μmol/L进行后续实验。HE染色和Image J结果显示ALN剂量为1.0 μmol/L时,肌小管直径和融合指数显著增加（P＜0.01）。Western blot结果显示,与对照组相比,Dexa组细胞MuRF1蛋白表达水平升高;而与Dexa组相比,Dexa+ALN组MuRF1蛋白表达水平显著下调,自噬相关蛋白LC3、Beclin-1的表达增多（P＜0.01）。免疫荧光结果显示,与对照组相比,Dexa组MHC蛋白荧光表达强度（红光）明显降低;与Dexa组相比,Dexa+ALN组MHC蛋白荧光表达强度表达显著升高。结论　1.0 μmol/L ALN能有效促进C2C12细胞增殖分化,改善Dexa对C2C12细胞分化的抑制作用,抑制肌降解蛋白MuRF1表达,其机制可能与适度激活自噬信号通路有关。     

Pomegranate peel extract polyphenols induced apoptosis in human hepatoma cells by mitochondrial pathway

This study was aimed to investigate the influence of pomegranate peel polyphenols (PPPs) on the proliferation and apoptosis of HepG2 cells (a kind of human hepatoma cells) and the related mechanism. The inverted fluorescence microscope and the flow cytometer (FCM) were used to test the changes of the cellular morphology, cell cycle, apoptosis, reactive oxygen species (ROS) and mitochondrial transmembrane potential (Δψm). The kit was used to measure the activities of caspase-3/9, and Western Blot was used to detect the expressions of apoptosis-associated proteins including p53, Bcl-2/Bax, Cyt-c and PARP. The results showed that the cells cycle of HepG2 arrested at the S-phase by PPPs and the amount of the early apoptotic cells and ROS level were increased obviously, the level of Cyt-c and the activity of Caspase-3/9 markedly were also increased by PPPs, as well as the ratio of Bax/Bcl-2 and the protein expressions of P53. It was concluded that PPPs could inhibit the growth of HepG2 cells by blocking the cell cycle and inducing the mitochondrial apoptotic pathway in a dose-dependent manner.