多胺缀合物WJH-6诱导白血病细胞凋亡机制研究

探讨新型多胺缀合物WJH-6对多胺转运体的识别及其诱导K562、HL-60白血病细胞凋亡的机制。采用MTT法检测细胞毒性; 应用流式细胞仪检测细胞周期及凋亡率的变化; 应用高内涵活细胞成像系统检测WJH-6对多胺转运体的识别, 细胞内含量的变化及对线粒体膜电位、Bid、Caspase-3、-8、-9的影响; 采用Western blotting方法检测线粒体及胞浆中细胞色素c含量的变化。实验结果显示, WJH-6具有良好的多胺转运体识别能力, 并可诱导白血病K562、HL-60细胞线粒体膜电位降低、细胞色素c释放以及Bid、Caspase-3、-8、-9等活化。本研究结果提示, WJH-6诱导的白血病K562、HL-60细胞凋亡与线粒体损伤有关。     

Hsp90抑制剂新生霉素诱导HL-60细胞凋亡及其机制

目的研究Hsp90抑制剂新生霉素(novobiocin,NB)诱导HL-60细胞凋亡的作用,探讨该作用与线粒体凋亡途径的关系,并进一步研究NB对Hsp90客户蛋白(clientprotein)AKT和ERK2功能的影响。方法细胞用NB处理后,采用AO/EB染色后荧光显微镜观察凋亡形态,采用AnnexinV-FITC/PI双染后流式细胞仪检测细胞凋亡率,分光光度法检测Caspase-9和Caspase-3的活性,用蛋白免疫印迹法检测细胞色素C的含量,以及procaspase-3、p-AKT(Ser473)和p-ERK2的蛋白水平。结果NB能明显抑制HL-60细胞增殖,IC50是0.3546mmol.L-1;NB能促进细胞色素C释放入胞质,激活Caspase-3/9的活性,触发HL-60细胞凋亡;NB能抑制AKT和ERK的功能,使细胞内p-AKT(Ser473)和p-ERK2的蛋白含量减少。结论NB可通过线粒体途径诱导HL-60细胞凋亡,还可干扰Hsp90伴侣功能阻断增殖信号通路,抑制HL-60细胞生长。     

依他尼酸甲酯诱导人急性髓性白血病HL-60细胞凋亡作用和机制的初步探讨

目的研究依他尼酸甲酯(EAME)对人急性髓性白血病HL-60细胞的凋亡诱导作用,并初步探讨EAME诱导HL-60细胞凋亡的机制。方法采用吖啶橙(AO)、溴化乙啶(EB)双染法考察药物的凋亡诱导活性;采用流式细胞术检测活性氧的蓄积和线粒体膜电位的变化;利用荧光标记法检测细胞内还原型谷胱甘肽(GSH)含量的变化。结果EAME浓度在2~10μmol.L-1内对HL-60细胞具有显著的凋亡诱导能力;EAME诱导活性氧蓄积,降低线粒体膜电位和细胞内GSH含量;N-乙酰半胱氨酸(NAC)能够完全逆转EAME对GSH水平的耗竭作用及对HL-60细胞的凋亡诱导作用;丁硫氨酸亚砜胺(BSO)可以协同EAME进一步降低细胞内GSH水平,同时增强凋亡诱导能力。结论EAME可诱导HL-60细胞发生凋亡,活性氧在凋亡诱导过程中起主要作用。细胞内GSH水平与细胞对EAME诱导凋亡的敏感性呈反向相关。     

镉诱发HEK293细胞凋亡的线粒体途径

目的研究镉引起的HEK293细胞凋亡与线粒体的关系。方法分别以2′,7′-二氯荧光素二酯和若丹明123为荧光探针,经流式细胞仪检测胞浆内活性氧含量和线粒体膜电位的变化;Western印迹法检测线粒体细胞色素c的释放。结果在镉诱导HEK293细胞的凋亡过程中,胞浆内的活性氧水平升高,但能被抗氧化剂N-乙酰-L-半胱氨酸(NAC)抑制;同时,镉使线粒体膜电位下降和线粒体细胞色素c释放进入胞浆,二者都被NAC加剧。结论镉诱导HEK293细胞的凋亡可能通过线粒体途径。     

华蟾素诱导HL-60细胞凋亡及机制研究

目的：观察华蟾素（cinobufacini）对白血病HL-60细胞的增殖抑制作用和诱导凋亡作用的机制。方法：以HL-60细胞为研究对象，采用MTT法观察细胞增殖作用；Annexin V-FITC／PI双染和吖啶橙／溴乙锭（AO／EB）荧光染色法检测细胞凋亡；罗丹明染色法检测线粒体膜电位；分光光度法检测Caspase-3活性。结果：在0．78～6．25μg·ml^-1，华蟾素能明显的抑制HL-60细胞的增殖；华蟾素作用24h后，AnnexinV阳性的细胞从7．81％增加至66．02％，而且在荧光显微镜下可以明显观察到凋亡细胞；线粒体膜电位下降和Caspase-3活性升高。结论：华蟾素能够抑制HL-60细胞增殖，这种作用与其诱导细胞凋亡破坏线粒体功能和激活Caspase-3有关。     

Zeylenone抑制人前列腺癌PC-3细胞增殖及诱导凋亡作用研究

目的研究(4R,5S,6S)-4-苯甲酰氧基-6-[(苯甲酰氧基)甲基]-5,6-二羟基-2-环己烯-1-酮Zeylenone(Zey)对人前列腺癌PC-3细胞的生长抑制和诱导凋亡作用。方法采用MTT法观察Zey对PC-3细胞和正常前列腺基质细胞WPMY-1的增殖抑制作用,应用平板克隆形成实验观察Zey对PC-3细胞克隆形成的作用,AO/EB荧光染色观察细胞形态、JC-1染色观察Zey对细胞内线粒体膜电位的影响,An-nexin V-FITC/PI双染检测凋亡细胞比率,Western blot检测凋亡相关蛋白Caspase-9、Caspase-8、Caspase-3、Caspase-7和PARP的激活及Bcl-2、Bax、Bid、Bcl-xL蛋白的表达。结果Zey可以明显抑制人前列腺癌PC-3细胞的增殖并诱导其凋亡,而对正常前列腺基质细胞WPMY-1的抑制作用显著低于PC-3细胞。Zey抑制PC-3细胞克隆形成并明显诱导其凋亡。线粒体膜电位检测结果显示Zey导致细胞内线粒体膜电位的明显降低,Western blot检测结果表明Caspase-8、Caspase-9、Caspase-7、Caspase-3被激活,PARP和Bid被剪切活化,Bcl-2、Bcl-xL表达下降,而Bax表达上调。结论 Zey可选择性抑制人非激素依赖性前列腺癌PC-3细胞的增殖并诱导其凋亡,作用机制与其对Bcl-2和Caspase家族蛋白的影响,从而诱导PC-3细胞发生内源性和外源性凋亡相关。Zey有望成为治疗前列腺癌的候选药物。     

乙酰水杨酸增强多胺衍生物ANISpm抗肝癌作用及其机制研究

探讨乙酰水杨酸增强多胺衍生物ANISpm抗肝癌作用及其作用机制。采用MTT法检测细胞毒性;应用高内涵活细胞成像系统检测细胞内ANISpm含量的变化及对细胞凋亡和线粒体膜电位的影响;采用Western blotting方法检测细胞色素c,精脒/精胺乙酰转移酶,Caspase-3、-8、-9等蛋白表达的变化;应用高效液相色谱法检测细胞内多胺含量的变化。应用H22肿瘤移植模型评价对实体瘤生长的影响。实验结果显示,乙酰水杨酸体内外均具有增强ANISpm抗肝癌的作用,其机制为乙酰水杨酸通过上调肝癌细胞内精脒/精胺乙酰转移酶的活性,降低细胞内多胺含量从而增加了ANISpm的摄取,并通过ANISpm诱导肝癌细胞凋亡。该凋亡作用与ANISpm诱导细胞线粒体膜电位降低,促进细胞色素c释放以及活化Caspase-3、-8、-9等有关。     

姜黄素对皮层神经元氧化损伤的保护作用

目的　观察姜黄素对第三丁基过氧化氢 (tert butylhy droperoxide,t BHP ,tBHP)诱导的大鼠皮层神经元氧化损伤的影响 ,探讨可能的机制。方法　培养胚胎鼠皮层神经元 ,MTT法测定细胞活力 ,DNA断裂评价细胞凋亡 ,流式细胞术测定线粒体膜电位和细胞内活性氧水平 ,分光光度法测定细胞内谷胱甘肽 (GSH)水平 ,Westernblot法测定Bcl 2和Bax蛋白和胞浆细胞色素C以及活化型半胱氨酸天冬氨酸蛋白酶 3(caspase 3)和多聚 (ADP 核糖 )聚合酶 [poly (ADP ribose)poly merase,PARP]水平。结果　姜黄素 (2 5～ 2 0 μmol·L-1)可有效减少tBHP对神经元的氧化损伤和tBHP引起的细胞内GSH水平降低 ,降低细胞内的活性氧水平 ,增加线粒体膜电位和细胞内GSH以及Bcl 2蛋白水平 ,减少线粒体内细胞色素C向胞浆释放和Bax蛋白表达水平 ,最终明显减少cas pase 3和PARP活化和tBHP引起的神经元凋亡。结论　姜黄素可减弱tBHP对原代皮层神经元的氧化损伤作用 ,其作用可能与降低细胞内的活性氧水平 ,保护线粒体功能有关     

高脂通过线粒体通路诱导H9c2心肌细胞损伤

目的探讨高脂通过线粒体凋亡通路对H9c2心肌细胞的损伤作用。方法棕榈酸(0～0.4 mmol·L~(-1))刺激H9c2心肌细胞24 h和0.2 mmol·L~(-1)棕榈酸刺激H9c2心肌细胞(0～48 h);MTT法评估细胞生长状态;活性氧试剂盒检测细胞内活性氧水平;凋亡试剂盒检测细胞凋亡情况;线粒体膜电位试剂盒检测线粒体膜电位变化;免疫印迹法检测细胞内线粒体凋亡相关蛋白Cyt-C、Cleaved casepase-3、Bax、Bcl-2表达水平。结果棕榈酸刺激H9c2心肌细胞24 h,棕榈酸0.2、0.4 mmol·L~(-1)组细胞增殖率均出现明显下降;细胞内活性氧水平逐渐升高,线粒体膜电位下降,细胞凋亡增加。棕榈酸(0.2 mmol·L~(-1))刺激H9c2心肌细胞24、36、48 h均引起细胞增殖率明显下降。棕榈酸(0.4 mmol·L~(-1))刺激H9c2心肌24 h,线粒体相关蛋白Cyt-C、Cleaved casepase-3、Bax表达均明显增高(P <0. 05),而Bcl-2明显降低(P <0. 05)。结论线粒体凋亡信号通路可能对高脂所致H9c2心肌细胞损伤起重要作用。     

一氧化氮诱导PC12细胞凋亡及人参皂苷Rg1的保护作用

目的　探讨一氧化氮诱导PC12细胞凋亡及人参皂苷Rg1保护作用的可能机制。 方法　DNA凝胶电泳观察DNA的断裂情况 ,流式细胞仪检测线粒体跨膜电位 ,West ernblotting检测胞浆细胞色素C和活化型半胱氨酸蛋白水解酶caspase 3P2 0 水平。结果　一氧化氮供体SNAP(5 0 0μmol·L-1)可诱导PC12细胞凋亡 ,细胞线粒体跨膜电位明显下降、胞浆细胞色素C水平增加及caspase 3得到激活 ;预先经过 5 0、10和 2 0 μmol·L-1等浓度人参皂苷Rg1处理后 ,SNAP诱导的PC12细胞凋亡明显减少 ,同时明显减弱SNAP对细胞线粒体跨膜电位、胞浆细胞色素C水平及cas pase 3激活的影响。 结论　人参皂苷Rg1可抑制一氧化氮诱导PC12细胞凋亡 ,其作用机制可能与其稳定细胞线粒体跨膜电位、减少线粒体细胞色素C向胞浆释放及抑制cas pase 3的激活有关     

Juglone,from Juglans mandshruica Maxim,inhibits growth and induces apoptosis in human leukemia cell HL-60 through a reactive oxygen species-dependent mechanism

Juglone, a major chemical constituent of Juglans mandshruica Maxim, is a promising anticancer agent that has shown a strong activity against cancer cells in vitro. Our previous study showed that juglone inhibited the proliferation of HL-60 cells with an IC50 value ～8 μM. To further explore the proapoptotic mechanism of juglone, we investigated the role of the reactive oxygen species (ROS) in the apoptosis induced by juglone in HL-60 cells. The generation of ROS was about 2 to 8-fold as compared to control cell after treatment with juglone (2, 4 and 8 μM) for 24 h. The glutathione (GSH) depletion was consistent with ROS generation after treatment with juglone. Reversal of apoptosis in antioxidants (NAC and catalase) pretreated cells indicated the involvement of ROS in juglone-induced apoptosis. The cleavage of PARP and procaspase-3 and -9, loss of mitochondrial membrane potential (△Ψm), and release of cytochrome c (Cyt c) and Smac induced by juglone were significantly blocked by NAC. NAC also prevented the inhibition the phosphorylation of Akt and mTOR proteins by juglone. Collectively, these results indicated that ROS played a significant role in the apoptosis induced by juglone in human leukemia cell HL-60.     

2,3,5-tris(Glutathion-S-yl)hydroquinone (TGHQ)-mediated apoptosis of human promyelocytic leukemia cells is preceded by mitochondrial cytochrome c release in the absence of a decrease in the mitochondrial membrane potential.

2,3,5-tris(Glutathion-S-yl)hydroquinone (TGHQ), a metabolite of benzene, induces apoptosis in human promyelocytic leukemia (HL-60) cells. However, the mechanisms by which TGHQ induces apoptosis are unclear, and they were the focus of the present investigation. TGHQ stimulated the rapid formation (30 min) of reactive oxygen species (ROS) in HL-60 cells, and co-treatment with catalase or the antioxidant N-acetylcysteine (NAC) completely blocked TGHQ-induced apoptosis, implicating a causative role for ROS in HL-60 cell death. Western blot analysis revealed the complete disappearance of pro-caspase 9 between 1 and 2 hours after exposure of HL-60 cells to TGHQ, concomitant with the appearance of cleaved caspase 9 and increases in caspase 9 activity. The appearance of two cleaved forms of caspase 3 occurred subsequent to increases in caspase 9 activity. Levels of the anti-apoptotic Bcl-2 protein remained constant during TGHQ-induced apoptosis of HL-60 cells, but Bcl-2 S70 phosphorylation decreased. In contrast, changes in the subcellular localization of the pro-apoptotic molecule Bax were observed, with a rapid (15-60 min) increase in the ratio of cytosolic to mitochondrial Bax. Cytochrome c release from mitochondria to the cytosol occurred after Bax translocation and the dephosphorylation of pS70 Bcl-2. However the mitochondrial inner transmembrane potential (deltapsi(m)) was maintained, even after cytochrome c was released from the mitochondria. Cyclosporin A, an inhibitor of the mitochondrial membrane permeability transition pore (PTP), did not completely rescue HL-60 cells from apoptosis. Taken together, we conclude that TGHQ facilitates ROS production, alters the post-translational modification of Bcl-2 and subcellular localization of Bax, culminating in the release of cytochrome c and caspase activation.     

梁金菇多糖促人急性早幼粒细胞白血病细胞系(HL-60)细胞凋亡研究

目的 :观察梁金菇多糖对人类早幼粒细胞白血病细胞系 (HL 6 0 )是否具有凋亡诱导作用 ,并进一步研究半胱天冬酶 3(Caspase 3)基因在此过程中的作用。方法 :四氮唑蓝比色法 (MTT法 )观察梁金菇多糖对HL 6 0细胞的抑制率 ,应用形态学、流式细胞术、DNA凝胶电泳等方法检测细胞凋亡的发生。应用半定量逆转录 聚合酶链反应 (RT PCR)法检测凋亡相关基因Caspase 3mRNA表达的变化。结果 :梁金菇多糖对HL 6 0细胞的生长有明显的抑制作用 ,并诱导肿瘤细胞发生凋亡 ;在HL 6 0细胞凋亡过程中 ,凋亡相关基因Caspase 3转录水平比用药前增强。结论 :梁金菇多糖促HL 6 0细胞凋亡 ,且与Caspase 3基因表达有关     

Mitochondrial-dependent, reactive oxygen species-independent apoptosis by myricetin: roles of protein kinase C, cytochrome c, and caspase cascade

Abrogation of mitochondrial permeability and induction of reactive oxygen species (ROS) production have been observed in chemical-induced apoptosis; however, the relationship between the mitochondria and intracellular ROS levels in apoptosis is still unclear. In the present study, myricetin (ME) but not its respective glycoside, myricitrin (MI; myricetin-3-O-rhamnose) reduced the viability of human leukemia HL-60 cells via apoptosis, characterized by the occurrence of DNA ladders and hypodiploid cells. Results of Western blotting and caspase activity assays showed that activation of caspases 3 and 9 but not caspases 1, 6 or 8 with cleavage of PARP and D4-GDI proteins is involved in ME-induced apoptosis. A reduction in mitochondrial functions characterized by a decrease in the Bcl-2/Bax protein ratio and translocation of cytochrome c (cyt c) from the mitochondria to the cytosol in accordance with a decrease in mitochondrial membrane potential were observed in ME-treated HL-60 cells. No significant induction of intracellular ROS levels by ME was observed by the DCHF-DA assay, DPPH assay or plasmid digestion assay, and antioxidants including N-acetyl-cysteine (NAC), catalase (CAT), superoxide dismutase (SOD), and tiron (TIR) showed no protective effects on ME-induced apoptosis. A PKC activator, 12-O-tetradecaoylphorbol-13-acetate (TPA) significantly attenuated ME-induced apoptosis via preventing cytochrome c release to the cytosol and maintaining the mitochondrial membrane potential by inhibiting the decrease in the Bcl-2/Bax protein ratio; these effects were blocked by protein kinase C (PKC) inhibitors including GF-109203X, H7, and staurosporin. Removing mitochondria by ethidium bromide (EtBr) treatment reduced the apoptotic effect of ME. Results of SAR studies showed that the presence of OH at C3′, C4′, and C5′ is important for the apoptosis-inducing activities of ME, and that ME induces apoptosis in another leukemia cell line, Jurkat cells, but not in primary human polymorphonuclear (PMN) cells or in murine peritoneal macrophages (PMs). The results of the present study suggest that apoptosis induced by ME occurs through a novel mitochondrion-dependent, ROS-independent pathway; TPA protects cells from ME-induced apoptosis via PKC activation which prevents the occurrence of mitochondrial destruction during apoptosis.     

Glaucocalyxin A induces apoptosis in human leukemia HL-60 cells through mitochondria-mediated death pathway

Glaucocalyxin A (GLA) is a biologically active ent-kauranoid diterpenoid isolated from Rabdosia japonica var. glaucocalyx, a traditional Chinese medicinal herb, which has been shown to inhibit tumor cell proliferation. However, the mechanism underlying GLA-induced cytotoxicity remains unclear. In this study, we focused on the effect of GLA induction on apoptosis, the mitochondria-mediated death pathway and the accumulation of reactive oxygen species (ROS) in human leukemia cells (HL-60). GLA could induce a dose-dependent apoptosis in HL-60 cells as characterized by cell morphology, DNA fragmentation, activation of caspase-3, -9 and an increased expression ratio of Bax/Bcl-2. The mitochondrial membrane potential (Δψ_m) loss and cytochrome c release from mitochondria to cytosol were observed during the induction. Moreover, GLA caused a time- and dose-dependent elevation of intracellular ROS level in HL-60 cells, and N-acetyl-l-cysteine (NAC, a well-known antioxidant) could block GLA-induced ROS generation and apoptosis. These data suggest that GLA induces apoptosis in HL-60 cells through ROS-dependent mitochondrial dysfunction pathway.     

Ethyl acetate fraction of Garcina epunctata induces apoptosis in human promyelocytic cells (HL-60) through the ROS generation and G0/G1 cell cycle arrest: A bioassay-guided approach

Number of deaths due to cancer diseases is increasing in the world. There is an urgent need to develop alternative therapeutic measures against the disease. Our study reports the cytotoxicity activity of Garcina epunctata (gutifferae) in human promyelocytic leukemia cells (HL-60) and prostate cancer cells (PC-3) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Changes in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and morphological changes associated with apoptosis were examined by flow cytometry and Hoescht staining respectively. The results of in vitro antiproliferative screening of fractions and extract from G. epunctata indicated that three fractions inhibited the viability of PC-3 cells with IC₅₀ varied from 50 to 88 μ/ml while two fractions inhibited the proliferation of HL-60 cells with IC₅₀ range between 47.5 and 12 μg/ml. Among the entire fraction tested, Hex-EtOAc (75:25) showed cytotoxic effects on the two cell lines and EtOAc fraction was most active only HL-60 cells (12 μg/ml). Treatment of HL-60 cells with G. epunctata (20, 50, 100 μg/ml) for 24 h led to a significant dose-dependent increase in the percentage of cells in sub-G1 phase by analysis of the content of DNA in cells, and a number of apoptotic bodies containing nuclear fragments were observed in cells treated with 100 μg/ml. The EtOAc fraction of G. epunctata treatment significantly arrested HL-60 cells at the G0/G1 phase (p < 0.05) and ROS was significantly elevated as well as the loss of membrane mitochondrial potential in a concentration dependant manner. The results demonstrated that the EtOAc fraction of G. epunctata inhibited the proliferation of HL-60 cells, leading to cell cycle arrest and programmed cell death, which was confirmed to occur through the mitochondrial pathway.     

珠子参总皂苷对H2O2诱导新生大鼠心肌细胞凋亡的抑制作用

目的:观察珠子参总皂苷对H2O2诱导新生大鼠心肌细胞凋亡的抑制作用,并探讨其作用机制.方法:Wistar乳鼠心肌细胞原代培养,用H2O2建立氧化应激损伤模型,然后用珠子参总皂苷(100,200 μg/mL)孵育24 h后,MTT法检测珠子参总皂苷对细胞活力的影响,流式细胞仪和Hoechst33258染色检测珠子参总皂苷对氧化应激诱导细胞凋亡及胞内ROS含量的影响,比色法测定心肌细胞Caspase-3、Caspase-9的活性,荧光定量PCR测定心肌细胞Bcl-2和Bax mRNA表达,并计算Bcl-2与Bax的比值.结果:珠子参总皂苷(100,200 μg/mL)能显著改善心肌细胞活性,有效保护线粒体膜电位的稳定,抑制心肌细胞凋亡和改善细胞形态,降低细胞内活性氧(ROS)含量;下调Bax mRNA表达,上调Bcl-2mRNA表达及Bcl-2与Bax的比值;降低H2O2所致新生大鼠心肌细胞中Caspase-3、Caspase-9的活性.结论:珠子参总皂苷对H2O2诱导心肌细胞凋亡有显著的抑制作用,其机制可能与其稳定心肌细胞膜、清除ROS及调节心肌细胞Bcl-2、Bax和Caspase-3、Caspase 9表达有关.     

美洲大蠊提取物对人肝癌细胞Bel-7402作用机制的研究

目的探讨美洲大蠊提取物对人肝癌细胞Bel-7402的作用机制。方法 MTT比色法观察美洲大蠊提取物对人肝癌细胞Bel-7402增殖的影响,AnnexinV-FITC/PI双染色法研究美洲大蠊提取物对人肝癌细胞Bel-7402凋亡的影响,流式细胞术检测线粒体膜电位,DNA Ladder实验检测细胞凋亡,蛋白印迹法检测Bax、Bcl-2、Caspase-9、Caspase-3、Caspase-8蛋白的表达。结果美洲大蠊提取物可抑制人肝癌细胞Bel-7402增殖,IC50为28.2μg.mL 1,并可诱导人肝癌细胞Bel-7402凋亡,降低线粒体膜电位。DNA Ladder实验可见明显的梯形电泳图谱,蛋白印迹法显示Bax、Caspase-9、Caspase-3蛋白表达增强,Bcl-2蛋白表达减弱,Caspase-8蛋白表达无明显变化。结论美洲大蠊提取物可通过线粒体途径诱导人肝癌细胞Bel-7402凋亡。