Apoptotic-like death occurs through a caspase-independent route in colon carcinoma cells undergoing mitotic catastrophe

We have examined the relationship between chemotherapy-induced mitotic catastrophe and cell death by apoptosis in both wild-type and p53(()(-)(/-)) HCT116 human colon carcinoma cells treated with nanomolar concentrations of paclitaxel (PTX), a drug that acts on tubulin altering the normal development of mitosis. After treatment, HCT116 cells entered mitosis regardless of the presence of functional p53, which resulted in changes in the distribution of cells in the different phases of the cell cycle, and in cell death. In the presence of PTX, the percentage of polyploid cells observed was higher in p53-deficient cells, indicating that mitotic slippage was favored compared to wild-type cells, with the presence of large multinucleate cells. PTX caused mitotic catastrophe and about 50-60% cells that were entering an aberrant mitosis died through an apoptotic-like pathway characterized by the presence of phosphatidylserine in the outer cell membrane, which occurred in the absence of significant activation of caspases. Lack of p53 facilitated endoreduplication and polyploidy in PTX-treated cells, but cells were still killed with similar efficacy through the same apoptotic-like mechanism in the absence of caspase activity.     

大鼠缺血再灌流脑区半胱氨酸蛋白酶-3活化与神经元凋亡的关系

目的　探讨缺血再灌流脑区半胱氨酸蛋白酶 3(caspase 3)活性变化与神经元凋亡的关系。方法　采用WesternBlotting、原位细胞凋亡检测和免疫组化染色等方法,观察大鼠大脑中动脉栓塞 2h后再灌流 1、6、12、24h时,颞顶叶皮层缺血脑区caspase 3表达和活化、多 (ADP 核糖 )聚合酶(PARP)表达和切割灭活及神经元凋亡程度的变化。结果　再灌流 1、6、12及 24h组,缺血脑区的caspase 3前体及其 12 000切割片段含量的相对灰度值分别为 16 72±2 96、28 36±3 51、51 15±3 10、76 14±3 45及 8 17±2 31、15 36±1 39、31 23±5 43、58 95±6 28;PARP及其 24 000切割片段含量的相对灰度值分别为 12 63±3 02、22 65±4 38、30 81±3 16、67 49±8 59及 6 02±0 73、12 86±2 30、20 76±3 16、27 36±2 63;PARP阳性神经元及凋亡神经元的密度 (细胞数 /0 1mm2 )分别为 68 00±6 67、91 40±9 56、112 20±11 78、127 00±11 51及 83 31±7 53、100 70±6 16、121 53±7 21、197 36±11 78。以上 6种指标的变化彼此间均呈正相关 (r= 0 805 ~0 942, P<0 01 );除 6h与 12h组间PARP含量的差异及 6h与 12h组间和 12h与 24h组间PARP阳性神经元密度的差异无统计学意义外,上述 6种指标的其余组间差异均有统计学意义 (P<0 0     

天花粉蛋白抑制HeLa细胞生长及诱导细胞凋亡之机制探讨

目的研究天花粉蛋白（TCS）对人宫颈癌HeLa细胞生长抑制作用及其机制,探讨HeLa细胞凋亡发生的分子机制.方法采用CCK-8的方法,检测TCS对HeLa细胞的抑制作用;流式细胞仪检测TCS对细胞周期的影响;电子显微镜和Annexin法观察TCS对HeLa细胞诱导凋亡的作用;应用Western blotting观察HeLa细胞caspase-3酶原的变化;用caspases活性检测试剂盒,检测caspase-3,8,9的活性.结果1.TCS对HeLa细胞的生长具有明显的抑制作用;2.TCS可以将HeLa细胞阻滞于S期;3.TCS诱导HeLa细胞发生凋亡,HeLa细胞出现典型的凋亡特征--染色质浓缩和凋亡小体,且凋亡率具有时间依赖性;4.caspase-3酶原表达的降低呈现时间和浓度依赖性,而caspase-3活性随时间依赖性的增高,提示在TCS诱导HeLa细胞凋亡的过程中caspase-3被激活;5.caspase-8,9的活性增高,有时间依赖性,且具有时间顺序.100 mg/L TCS处理24h后,caspase-8早于caspase-3被激活,提示活化的caspase-8可能对caspase-3起到激活作用.结论TCS对HeLa细胞的抑制作用是通过将HeLa细胞阻滞于S期和诱导细胞凋亡来实现的.caspase-3的激活是介导TCS诱导HeLa细胞发生凋亡的通路,同时,活化的caspase-8,9可能参与了caspase-3的激活和凋亡的诱导.     

脑缺血损伤的分子机制研究进展

脑缺血疾病具有发病率高、死亡率高的特点 ,严重危害人类健康。尽管近几十年来对脑缺血进行了大量的研究[2 8- 3 0 ] ,但急性脑缺血的预后仍相当差。究其原因是由于脑缺血损伤的机制十分复杂 ,缺乏有效的干预手段。它的复杂性主要表现在 :脑缺血类型的复杂性 (包括局灶的或全脑的 ,完全的或不完全的 ,短暂的或永久的 )和脑缺血损伤分子机制在时空变化上的复杂性以及各作用因子间相互影响的复杂性。因此 ,迄今为止没有一种机制能完全阐明脑缺血的损伤机制。现认为参与脑缺血损伤的分子机制有兴奋性氨基酸的释放、钙离子稳态失衡、自由基的形…     

氧化应激诱导HepG2肝癌细胞凋亡的研究(英)

目的：直接暴露细胞于活性氧能诱导发生凋亡，本文研究氧化应激诱导HepG2肝癌细胞的死亡及其机制。方法：暴露细胞于2 mmol/L过氧化氢产生氧化应激，用DNA凝胶电泳检测细胞凋亡，用荧光染色法检测细胞线粒体膜电位变化，Western blotting检测细胞浆中细胞色素c变化，fluorometric assay kit检测caspase活性变化。结果：氧化应激作用于HepG2细胞后12 h开始发生凋亡；氧化应激作用后4 h，细胞线粒体膜电位明显下降；胞浆中细胞色素c浓度呈时间依赖性增高；氧化应激作用8 h、12 h后细胞内caspase-3、caspase-9活性分别升高6.7及3.6倍，但caspase-8活性无变化。结论：氧化应激能诱导HepG2肝癌细胞发生凋亡，其途径与线粒体通路及caspase激活有关。     

外源性FasL基因诱导肺癌细胞Caspase-3的表达及凋亡

目的 :研究FasL基因转染肺癌细胞中Caspase 3的表达及与细胞凋亡的关系。方法 :RT PCR、流式细胞术和免疫组化检测Caspase 3在FasL基因转染的A 5 49/FasL细胞中的表达 ,流式细胞术、原位末端标记 (TUNEL)检测细胞凋亡。结果 :Caspase 3在A 5 49母系细胞中低水平表达 ,转基因后的A 5 49/FasL细胞的Caspase 3的表达和活性显著升高 ,P <0 0 1。同时肺癌细胞凋亡率升高( 4 4 0 8%vs 18 15 % ,P <0 0 1)。凋亡率与Caspase 3的活性呈明显正相关关系 ,r =0 64 7,P <0 0 1。肿瘤细胞中的凋亡与其Caspase 3 的表达有明显的关系。结论 :Caspase 3在肺癌发生中起重要作用 ,FasL基因转染的肺癌细胞的凋亡与其Caspase 3的表达增加有密切关系     

非霍奇金淋巴瘤组织Caspase-3和Ki-67的表达

目的 :研究Caspase 3蛋白在非霍奇金氏淋巴瘤 (non Hodgkin’slymphoma ,NHL)中的表达及与细胞增殖相关抗原Ki 67的关系。方法 :应用免疫组织化学Envi sionsystem法检测NHL患者组织标本Cas pase 3蛋白和Ki 67的表达。 结果 :Caspase 3蛋白在 5 4例NHL中的阳性率为 83 3 %( 4 5 /5 4)。Caspase 3表达与NHL恶性度相关 ,r =0 3 75 ,P <0 0 1;NHL低、中 -高度恶性表达率分别为 66 7% ( 14 /2 1)、93 9%( 3 1/3 3 ) ,2组之间差异有统计学意义 ,P <0 0 5。Ki 67表达与NHL恶性度具有相关性 ,r =0 3 3 4,P <0 0 5。结论 :Caspase 3介导的凋亡作用可能在NHL肿瘤发生和发展中有一定意义。Ki 67表达对NHL病理分级、诊断及治疗有一定参考价值     

Nicotinamide-cinnamic acid cocktail exerts pancreatic β-cells survival coupled with insulin secretion through ERK1/2 signaling pathway in an animal model of apoptosis

PurposePancreatic β-cells protection is integral to insulin secretion in diabetic conditions. In this context, we investigated cinnamic acid in combination with nicotinamide on the regulation of insulin secretion and apoptosis in pancreatic β-cells using streptozotocin (STZ)-induced apoptotic model in vivo.MethodsThe pancreata of nicotinamide (NA)-cinnamic acid (CA) treated rats were studied using histopathological, immunofluorescence, molecular docking, and RT-PCR analyses, supported by serum glucose and insulin levels.ResultsThe biochemical data revealed that the acute treatment of NA and CA in combination significantly increased serum insulin, thereby lowering blood glucose level in vivo. From histological findings, NA-CA pre-treatment displayed significant protection against STZ-apoptotic trends, improved insulin secretion, and recapitulated the STZ-induced morphology to normal control. The upregulated expressions of caspases, caused by STZ-treatments, were significantly downregulated with NA-CA in immunofluorescent detection and their translational levels, respectively. We found dense ERK½-insulin staining and p-ERK½ expression, which was further supported by strong ERK½ residues-ligands interactions based on in silico analysis.ConclusionFrom the pre-clinical data, we thus conclude that NA-CA cocktail exerts dual insulin releasing and survival effects in pancreatic β-cells by targeting ERK½ pathway.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s40199-021-00412-w.     

MAPK activation is necessary to the apoptotic death of KB cells induced by the essential oil isolated from Artemisia iwayomogi

Aim of the study

Artemisia iwayomogi is a perennial small herbal plant that has long been used as a chemopreventive agent in traditional Korean medicine. Previously, the purified essential oil was isolated from Artemisia iwayomogi, herein named AIEO, and found to contain the active components responsible for the chemopreventive potential of the herb.

Materials and methods

This study examined whether or not AIEO has potential chemopreventative effects against cancer using the human oral epidermoid carcinoma cell line, KB cells. The possible mechanism of AIEO-induced apoptosis was also examined.

Results

The results showed that AIEO induces the apoptotic death of KB cells, which is mediated by mitogen-activated protein kinases (MAPKs). In addition, AIEO not only induced an imbalance between the mitochondrial Bcl-2 and Bax levels with the concomitant release of Cytochrome c into the cytosol but also induced the activation of caspases and the cleavage of PARP. This induction was significantly suppressed by MAPK inhibitors. Moreover, pretreating the cells with each of the caspase or MAPK-specific inhibitors apparently inhibited AIEO-induced cytotoxicity of KB cells.

Conclusions

These results strongly suggest that AIEO might have cancer chemopreventive and therapeutic potential, which is closely related to its ability to activate the MAPK-mediated signaling pathways with the subsequent induction of a mitochondria- and caspase-dependent mechanism.     

Reactive Oxygen Species in Mitochondria-Mediated Cell Death

In addition to the well-established role of the mitochondria in energy metabolism, regulation of cell death has recently emerged as a second major function of these organelles. This, in turn, seems to be intimately linked to their role as the major intracellular source of reactive oxygen species (ROS) which are mainly, generated at Complex I and III of the respiratory chain. Excessive ROS production can lead to oxidation of macromolecules and has been implicated in mtDNA mutations, ageing, and cell death. Although mitochondrial dysfunction can cause ATP depletion and necrosis, these organelles are also involved in the regulation of apoptotic cell death by mechanisms, which have been conserved through evolution. Thus, many lethal agents target the mitochondria and cause release of cytochrome c and other pro-apoptotic proteins, which can trigger caspase activation and apoptosis. Taken together, these findings have placed the mitochondria in the focus of current cell death research.