生物材料诱导细胞凋亡的研究进展

针对近些年生物材料诱导细胞凋亡的现象和机制的研究情况，从凋亡信号传导角度分类综述了生物材料诱导细胞凋亡的途径，包括传统信号传导途径、死亡受体途径、以及近年发现的线粒体途径，另外也论述了生物材料诱导活性氧产生而发生的凋亡和影响细胞黏附导致的细胞凋亡等途径，发现生物材料诱导的细胞凋亡产生的途径具有明显的多样性、交叉性和多途径同时作用的特点。本综述对于生物材料诱导细胞凋亡机制的深入研究特别是生物材料的研制具有重要的指导意义。此外也为生物材料广泛应用于人类疾病特别是应用于与细胞凋亡紧密相关的癌症治疗提供了借鉴。     

砷剂介导的细胞凋亡信号转导途径

砷剂是一种安全有效的治疗血液恶性肿瘤的诱导剂 ,亦可用于治疗其它实体瘤。砷剂诱导细胞凋亡的信号传导途径为线粒体 -细胞色素 C途径 ,它在细胞凋亡网络调控中起重要作用。阐明其诱导细胞凋亡的分子生物学机制 ,为在临床上的合理应用砷剂并扩大其抗瘤作用谱奠定理论基础     

中性粒细胞凋亡的线粒体死亡机制的研究进展

中性粒细胞是血细胞中寿命最短的终末分化细胞,在炎症反应中发挥着重要的作用,是人体免疫防御系统的第一道防线。与其它的血细胞和组织细胞在凋亡的发生机制上有所不同,中性粒细胞从分化成熟开始,就启动它的自发性凋亡程序。中性粒细胞自发性凋亡涉及到许多复杂的生化过程,线粒体是细胞的一种重要的细胞器,也是真核生物能量代谢的中心、凋亡中心,其在中性粒细胞凋亡信号传导和病理生理过程中起着关键性的调节作用。因此,对线粒体途径的调控机制进行研究是非常重要的。     

动脉粥样硬化中巨噬细胞凋亡与内质网应激机制

巨噬细胞是机体免疫系统的重要细胞成份,具有多种生理功能,在动脉粥样硬化等血管疾病的发生和发展中具有重要作用.巨噬细胞凋亡是造成动脉粥样硬化斑块不稳定的重要因素,在晚期动脉粥样硬化中,内质网应激与巨噬细胞凋亡密切相关.目前已知的巨噬细胞凋亡途径包括外源性的死亡受体途径、内源性的线粒体途径及内质网应激凋亡途径,其中内质网应...     

线粒体相关内质网膜的钙信号

Ca2+稳态是细胞代谢、增殖、分化和凋亡的基础。细胞内Ca2+浓度的提高依赖于Ca2+由细胞外流入或者从内质网流出。内质网和线粒体之间的物理联接即MAM,是内质网和线粒体功能的关键,使Ca2+高效的从内质网转移至线粒体。研究内质网与线粒体的Ca2+信号对维持细胞代谢及功能至关重要。     

死亡受体的信号传导途径及其调节机制

细胞凋亡是多细胞生物保证个体正常发育成熟和维持正常生理过程所必需的。凋亡细胞表面有特定的感应器即死亡受体 ,死亡受体可以接受胞外的死亡信号而激活细胞内的凋亡机制。本文简要综述了死亡受体的信号传导途径及其调节机制的研究进展。死亡受体 CD95、TNFR1和 DR3的信号传导途径相似 ,均有死亡结构域结合蛋白 FADD和死亡效应蛋白 caspase- 8的参与 ,而 DR4和 DR5的信号传导途径研究得不是十分清楚 ,可能存在FADD依赖性和不依赖性两条不同的信号传导途径     

Ca2+与内质网途径的细胞凋亡

细胞Ca2+稳态的维持主要是通过内质网进行的，Ca2+在细胞内的活动多与内质网有关，胞内\[Ca2+\]的变化可以引起内质网应激，而过度的内质网应激则会导致细胞的凋亡。由于内质网和线粒体在细胞内空间结构上的接近，内质网释放的Ca2+又会引起线粒体途径的凋亡。一些内质网相关的因素也参与Ca2+所引起的细胞内质网途径的凋亡。     

T细胞在激活诱导凋亡中的信号途径

淋巴细胞AICD是免疫系统维持稳定的一种重要机制。现在已知的可引发AICD的途径包括CD3/TCR途径、CD2途径、CD47途径、CD30途径。它们最终将信号传递至两条凋亡途径,引起细胞死亡。第一条是死亡受体信号传导途径,其中主要包括Fas/PasL途径、Apo-TRAIL等TNF受体超家族起始的途径。另外,Bcl-2家族构成的线粒体途径可能参与一定的调节作用。     

T淋巴细胞凋亡及其调控机制的研究进展

T淋巴细胞凋亡是免疫系统维持稳定的一种重要机制,在多种疾病中起着重要作用.fas/FasL、Trail/trail受体等死亡受体信号传导可介导T淋巴细胞凋亡,线粒体在诱导细胞凋亡中也起着重要作用;而bcl-2家族、v-FLIP等抗细胞凋亡蛋白和转录因子Nur77等对T淋巴细胞凋亡起调控作用.     

Caspase 9及其相关分子基因表达水平改变对同型半胱氨酸内皮凋亡的影响

目的 了解caspase 3信号传导通路中上游分子Bcl 2、细胞色素c（cytochrome-c）、caspase 9在同型半胱氨酸作用下的人脐静脉血管内皮细胞内的mRNA及蛋白表达水平的改变，揭示线粒体参与信号传导链在caspase 3所介导的内皮细胞凋亡过程中的作用。方法 培养人脐静脉内皮细胞，用不同浓度同型半胱氨酸作用于细胞后，用逆转录-聚合酶链反应及Western印迹分别检测各分子基因及蛋白表达水平的改变。结果 Bcl 2、cytochrome-c和caspase 9在同型半胱氨酸作用下mRNA及蛋白表达水平下降，并且随同型半胱氨酸浓度的升高而降低。结论 Bcl 2可能参与了同型半胱氨酸促进细胞凋亡的信号传导途径。Caspase 3没有通过上游分子apoptosome和caspase 9途径活化。这些研究结果提示，同型半胱氨酸诱导细胞凋亡并不是通过以线粒体凋亡通路为主的信号传导通路。     

Flow cytometry of apoptotic cell death

The term apoptosis or programmed cell death defines a genetically encoded cell death program, which is morphologically and biochemically distinct from necrosis or accidental cell death. The characteristic morphological signs of apoptosis (cellular shrinkage, membrane blebbing, nuclear condensation and fragmentation) are the final results of a complex biochemical cascade of events which is an integral part of physiological homeostasis. Techniques designed to identify, quantitate and characterize apoptosis are numerous, but flow cytometry (FCM) remains the methodology of choice to study the apoptotic cascade in relation to cell type, trigger and time. This review outlines the main stages of the apoptotic cascade together with current FCM methods. All FCM apoptosis assays described have a solid experimental basis and have been used successfully in basic research on molecular and biochemical mechanisms of apoptosis. In various clinical settings the ability to follow the apoptotic process in patient samples may offer the rationale for optimal treatment schedules.     

小脑颗粒神经元低钾性凋亡过程中Arnt2核浆转位的分析

目的：分析大鼠小脑颗粒神经元 (CGNs) “低钾”性凋亡过程中Arnt2亚细胞定位的变化。方法：Western blotting法分析“低钾”性凋亡过程中CGNs 核抽提物中Arnt2蛋白质的表达变化，间接免疫荧光结合激光扫描共聚焦显微术 (LSM) 分析Arnt2蛋白质亚细胞定位的变化。结果：在CGNs细胞核抽提物中，“低钾”诱导30 min后Arnt2 蛋白质已明显表达上调，1 h后达至峰值水平，“低钾”诱导6 h后上调表达的Arnt2回落至正常对照水平；LSM分析显示位于正常CGNs 细胞核内的Arnt2在“低钾”作用下逐步向胞浆转移，并在CGNs凋亡末期与胞浆线粒体定位的HSP60完全重叠。结论：Arnt2在小脑颗粒神经元“低钾”性凋亡过程中发生了核浆转位；结果提示，Arnt2很可能是通过传递“低钾”诱发的细胞凋亡或存活信号而直接参与小脑颗粒神经元“低钾”性凋亡的调控。     

Apoptosis in fimbriae of fallopian tubes and endometrium in pyoinflammatory adnexal diseases

In patients with pyoinflammatory adnexal diseases moderate or intense DNA degradation was observed in the majority of epithelial, stromal, and inflammatory infiltration cell in inflammatory foci in the fimbrial compartment of fallopian tubes without signs of tissue destruction. Expression of TNFR1 gene increased 2.7-fold and expression of Fas gene decreased 3.1-fold compared to intact endosalpinx, which indicates induction of apoptosis triggered by tumor necrosis factor- and inhibition of the Fas-dependent pathway. No signs of apoptosis were detected in the endometrium. Generalized apoptosis in the fimbrial compartment of the tubes can be a mechanism limiting the inflammatory process.     

Reactivation of Nedd-2, a developmentally down-regulated apoptotic gene, in apoptosis induced by a street strain of rabies virus

A laboratory strain of rabies virus has been reported to induce apoptosis in experimental animals. The present study demonstrated that a bat strain and a primary canine rabies virus isolate also induced apoptosis in vivo. This death process involved reactivation of the caspase gene, Nedd-2, a developmentally down-regulated apoptotic gene. Expression of Nedd-2 was significantly up-regulated in infected adult and suckling mice. Reactivation of Nedd-2 in infected adult mice started at around day 3 and was prominent on day 5. The level of expression was constantly high up to the time that mice showed signs of illness. Expression of Nedd-2 correlated with the appearance of apoptotic nuclei within the infected brain, suggesting that reactivation of a developmentally down-regulated gene, Nedd-2, may be required for apoptotic elimination of cells damaged by infection.     

Apoptosis in woman uterine cervix in pathologies associated with human papillomavirus

The level of apoptosis in uterine cervical tissue was evaluated in healthy women and in patients with various pathologies. No signs of apoptosis were found in unchanged stratified epithelium, condyloma latum, and condyloma acuminatum. The level of apoptosis decreased with progression of neoplastic epithelial transformations, usually no apoptosis was observed in samples of stage III cervical intraepithelial neoplasms. The development of preinvasive carcinoma was accompanied by activation of apoptotic processes most pronounced in the upper third of the epithelium. In some stage I and stage I-II cervical intraepithelial neoplasms, apoptosis and elimination of the basal layer cells caused rejection of the epithelium which can explain regression of this pathology at the initial stages. The prevalence of human papillomavirus infection directly correlated with neoplastic changes in the cervical epithelium.     

Direct versus indirect molecular diagnosis of fragile X mental retardation in 40 German families at risk.

In order to test whether the direct molecular diagnostic approach for fragile X mental retardation (Martin-Bell syndrome, MBS) really makes diagnosis of this disease more precise, we evaluated the results of direct diagnosis in 40 German families at risk together with the results of an earlier study with closely linked flanking markers in the same families. Of 84 men analysed, 43 showed clinical signs. In 39 of these affected men the disease could be confirmed by direct diagnosis. Compared to cytogenetic data, one man was false negative and two were false positive. Two men, whose status could not be determined by means of RFLP data, proved to be normal transmitting males (NTMs). However, the possibility of being an NTM had to be rejected in one case on RFLP data. Fragile X syndrome could be confirmed in 10 of the 13 women with clinical signs. Compared to cytogenetic data there were three cases of false negative results and one of false positive. All 36 obligate carrier women were detected by the direct approach. In addition, 22 women were newly identified as normal transmitting females (NTFs), among them one woman who could not be identified by cytogenetic means or by analysis with closely linked markers. These findings are discussed in view of the relative reliability of the three diagnostic approaches to MBS. Special attention is drawn to the significance of false negative and false positive results in direct diagnosis.     

Induction of apoptosis in HT-29 cells infected with SA-11 rotavirus

Rotavirus infection is associated both in vivo and in vitro with a series of subcellular pathological alterations leading to cell lysis. It has been suggested that these modifications can play a key role in the pathogenesis of rotavirus-associated diarrheal disease. We describe the effects of SA-11 rotavirus infection in HT-29 cells, a human enterocyte-like cell line. Cytological analyses suggested that the viral-induced cytopathic process, including chromatin clumping, can be referred to as apoptosis, the cell death pathway alternative to necrosis. A time course of the process was performed to investigate whether rotavirus-associated cell death showed specific injury signs. HT-29-infected cells were analyzed by scanning and transmission electron microscopy and features of apoptosis such as blebbing of the plasma membrane, peripheral condensation of chromatin, and fragmentation of the nucleus were observed. Specific changes occurring in cell-substrate adhesion and in some organelles relevant for viral maturation, i.e., rough endoplasmic reticulum, were detected. These findings indicate a role for apoptosis in the rotavirus infection process and its related cytopathology, and also suggested that specific histological alterations such as derangement of enterocytes are associated with the pathogenesis of rotavirus-induced diarrheal disease and could be a direct consequence of viral-triggered apoptosis. © 1996 Wiley-Liss, Inc.     

人胚胎干细胞对肝癌HepG2 细胞体外抑制作用的研究

目的:研究体外共培养情况下人胚胎干细胞H9 对肝癌HepG2 细胞的抑制作用。方法:建立人胚胎干细胞(H9) 与肝癌HepG2 细胞共培养体系,显微镜下观察胚胎干细胞对肿瘤细胞生物学行为的影响,流式细胞仪检测H9 细胞对肿瘤细胞的凋亡与周期的影响,Transwell 小室法检测H9 细胞对HepG2 细胞侵袭和迁移的影响,基因芯片分析共培养后HepG2 细胞全基因组的表达谱变化。结果:结果发现共培养过程中,肝癌HepG2 细胞生长受到抑制,随共培养时间延长,细胞数量逐渐减少,出现老化或凋亡迹象;流式细胞术检测发现HepG2 细胞凋亡率显著增加,细胞周期被阻滞于G0/ G1 期;Transwell 实验发现HepG2 细胞侵袭、迁移力均降低;基因芯片结果发现HepG2 细胞全基因组表达谱发生了显著变化,差异基因涉及多条信号通路。结论:人胚胎干细胞H9 体外对人肝癌细胞HepG2 有一定程度的抑制作用。     

Altered Mitochondrial Anatomy of Trigeminal Ganglia Neurons in Diabetes

Neurons from sensory ganglia are exposed to oxidative attack in diabetes. Altered mitochondrial morphologies are due to impaired dynamics (fusion, fission) and to cristae remodeling. This study aimed to evaluate using transmission electron microscopy mitochondrial changes in diabetic trigeminal ganglia suggestive for ignition of apoptosis, in absence of “classical” morphological signs of apoptosis. We used samples of trigeminal ganglia (from six type 2 diabetes human donors and five streptozotocin (STZ)‐induced diabetic rats). In human diabetic samples we found three main distributions of mitochondria: (a) small “dark” normal mitochondria, seemingly resulted from fission processes; (b) small “dark” damaged mitochondria, with side‐vesiculations (single‐ and double‐coated), large matrix vesicles and cytosolic leakage of reactive species, mixed with larger “light” mitochondria, swollen, and with crystolysis; (c) prevailing “light” mitochondria. In STZ‐treated rats a type (c) distribution prevailed, except for nociceptive neurons where we found a different distribution: large and giant mitochondria, suggestive for impaired mitochondrial fission, mitochondrial fenestrations, matrix vesicles interconnected by lamellar cristae, and mitochondrial leakage into the cytosol. Thus, the ultrastructural pattern of mitochondria damage in diabetic samples of sensory neurons may provide clues on the initiation of intrinsic apoptosis, even if the classical morphological signs of apoptosis are not present. Further studies, combining use of biochemical and ultrastructural techniques, may allow a better quantification of the degree in which mitochondrial damage, with membrane alterations and cytosolic leaks, may be used as morphological signs suggesting the point‐of‐no return for apoptosis. Anat Rec, 299:1561–1570, 2016. © 2016 Wiley Periodicals, Inc.