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1.
为研究线粒体膜通透性转换孔(mitochondrial permeablity transition pore,MPTP)在庆大霉素(gentamicin,GM)诱导MDCK细胞线粒体凋亡中的作用,试验用4 mmol/L GM和2μmol/L抑制剂CsA(cyclosporin A,CsA)单独或联合处理MDCK细胞24 h,流式细胞术检测MPTP开放情况和细胞凋亡率;JC-1探针检测线粒体膜电位的变化;荧光检测线粒体变化;免疫印迹法检测Bax与Bcl-2表达量,Caspase-9、Caspase-3和PARP蛋白活化情况,Cyt C和AIF释放。结果显示,CsA能够显著或极显著抑制GM引起的MDCK细胞MPTP的开放,细胞凋亡率的上升,线粒体膜电位下降,Bcl-2/Bax比值下降,Caspase-9、Caspase-3和PARP蛋白的活化以及Cyt C与AIF的释放(P0.05或P0.01);说明MPTP正向调节GM引起的MDCK线粒体凋亡。  相似文献   

2.
线粒体与细胞凋亡的关系   总被引:1,自引:0,他引:1  
线粒体是细胞能量合成和贮存及物质代谢、能量转化的重要场所,不仅能诱导细胞凋亡,还是细胞凋亡的执行者。在细胞凋亡过程中,与凋亡相关的活性物质,如细胞色素C(Cyt·c)、凋亡诱导因子(AIF)、B细胞淋巴瘤基因-2(Bcl-2)等从线粒体释放到膜间隙中,使线粒体膜通透性转换孔(mitochondrion permeability transition pore,MPTP)开放,削弱线粒体膜两侧的质子梯度,导致线粒体膜电位降低,诱导细胞凋亡。同时线粒体内的Bcl-2家族对细胞凋亡具有调节作用。笔者就MPTP、Cyt·c、AIF、Bcl-2与细胞凋亡的关系进行了综述。  相似文献   

3.
《中国兽医学报》2014,(10):1672-1675
为研究α-硫辛酸(α-lipoid acid,α-LA)对镉致PC12细胞线粒体凋亡途径的保护作用。10μmol/L醋酸镉和100μmol/Lα-LA单独或联合作用PC12细胞24h,流式细胞术检测细胞凋亡率,Western blot法检测cleaved caspase-3、Bcl-2和Bax蛋白的表达量和细胞色素C(cytochrome c,Cyt C)的释放。结果表明,镉引起细胞凋亡率上升,cleaved caspase-3表达上调,Bcl-2/Bax比值极显著下降(P<0.01),Cyt C从线粒体释放进入胞浆中(P<0.01);α-LA联合Cd处理,细胞凋亡率下降,cleaved caspase-3表达量下降,Bcl-2/Bax比值升高,并且能抑制线粒体中Cyt C的释放。表明α-LA对于镉诱导的PC12细胞凋亡的线粒体途径具有一定的保护作用。  相似文献   

4.
在细胞凋亡过程中,线粒体是调控细胞凋亡的中心,而细胞色素C(Cyt-C)从线粒体的释放则起着关键性作用。细胞色素C释放到胞质后可激活Caspase,引发级联反应,从而导致凋亡;Bcl-2蛋白家族具有调控细胞色素C释放的功能;凋亡诱导因子AIF保证着凋亡的有序进行;内质网(ER)通过应激、招募、活化等提高线粒体对促凋亡因子的敏感性,从而使细胞色素C从线粒体线粒体膜间隙(intermembrane space,IMS)释放,发挥了重要的作用。  相似文献   

5.
线粒体膜通透性变化与细胞凋亡的关系   总被引:4,自引:2,他引:2  
线粒体膜通透性转换孔是一种位于线粒体内膜的非选择性孔道,它的开放引起线粒体膜通透性改变,导致细胞色素C、凋亡诱导因子和Ca2+及膜间隙中的胱冬肽酶原等凋亡因子释放到细胞质中,致使细胞整体结构破坏、功能紊乱,发生凋亡。以前普遍认为线粒体膜通透性改变(mitochondrial permeability transition,MPT)是导致细胞凋亡的关键点,但一些新的研究结果表明,MPT与细胞凋亡并不存在必然的联系。作者结合细胞凋亡方面的研究着重就线粒体膜通透性转换的生物学功能和腺嘌呤核苷酸转位子、环孢素A 结合蛋白D及Bcl-2家族蛋白定位、转位在通透性转换中的作用及其与细胞凋亡的关系进行概括性论述与分析。  相似文献   

6.
BCL-2家族蛋白对线粒体膜通透作用的调控和caspases的影响   总被引:6,自引:2,他引:4  
线粒体通过释放凋亡蛋白来激活caspases和其它的细胞死亡受体,从而在转运细胞死亡信号中发挥重要作用。BCL-2家族蛋白位于线粒体膜上,对于凋亡因子来说,它具有调节线粒体膜通透性(MM P)的功能。最近的一些研究结果表明,BCL-2家族蛋白可能在释放线粒体凋亡因子中具有重要作用。  相似文献   

7.
线粒体与细胞凋亡   总被引:7,自引:0,他引:7  
浦雪艳  高洪  段纲 《猪业科学》2003,20(8):37-39
细胞凋亡是一种由基因控制的细胞自杀性死亡过程,是机体维持自身稳定的一种基本生理机制。机体通过细胞凋亡清除损伤、衰老与突变的细胞,维持生理平衡。通过对细胞凋亡的研究发现,线粒体在调节细胞凋亡中发挥着关键作用。尤其是被称为细胞凋亡主开关的线粒体通透性改变孔(MitochondrionPermeabilitytransitionPore,MPTP),它是细胞色素C、Smac、AIF等凋亡诱导因子的主要来源。本文以MPTP的开放、细胞色素C、AIF在细胞凋亡中的作用以及Bcl-2家族对细胞凋亡的调控做一综述,以便广大读者能系统地了解线粒体在细胞凋亡中的作用。  相似文献   

8.
线粒体通透性转换孔及其与细胞凋亡的关系   总被引:2,自引:0,他引:2  
线粒体通透性转换孔,又称线粒体巨型通道,是横跨线粒体内外膜之间的非选择性高导电性通道,由多种蛋白质复合组成。多数理论认为,它的开放所导致的线粒体膜通透性转换是线粒体导致细胞凋亡众多途径中关键的一个。现阶段对线粒体通透性转换孔有各种方向的研究。论文对其结构、作用机制及其与细胞凋亡的关系进行了综述。  相似文献   

9.
细胞凋亡及检测方法   总被引:1,自引:0,他引:1  
现代生物医学将细胞死亡分为坏死(necrosis)与凋亡(apoptosis)。细胞坏死是细胞突发性病理性死亡或生理环境骤然改变引起,由于细胞膜的通透性增高而引起大量细胞外水分和电解质进入细胞内,造成膜性系统如线粒体膜、溶酶体膜、胞浆膜发生破裂,释放的内容物中的溶酶体酶诱发相邻组织发生炎症。细胞凋亡是个体发育过程中基因调控下的细胞自杀活动,  相似文献   

10.
旨在探究死亡受体Fas在镉致大鼠肾上腺嗜铬细胞瘤细胞(PC12)凋亡中的作用及其对线粒体通路的调控机制,用10 μmol·L-1镉处理Fas基因沉默的PC12细胞株12 h,通过Western blot检测BH3相互作用域死亡激动剂(BID)、半胱氨酸蛋白酶-9(caspase-9)、半胱氨酸蛋白酶-3(caspase-3)、多聚二磷酸腺苷核糖聚合酶(PARP)的活化情况,Bcl-2相关X蛋白(Bax)、B细胞淋巴瘤/白血病-2基因(Bcl-2)、凋亡诱导因子(AIF)、核酸内切酶G(Endo G)的表达情况,以及细胞色素C(Cyt C)在细胞内的分布情况,免疫荧光染色检测AIF核转位。结果显示,镉极显著上调tBID/BID比值和Bax/Bcl-2比值,诱导Cyt C从线粒体释放到细胞质,激活caspase-9、caspase-3和PARP,增加AIF和Endo G蛋白表达水平(P<0.01),并诱导AIF核转位;沉默Fas极显著抑制镉引起的tBID/BID比值和Bax/Bcl-2比值升高,Cyt C从线粒体释放到胞浆,caspase-3、PARP蛋白活化和AIF、Endo G蛋白表达水平极显著升高(P<0.01),显著抑制镉激活的caspase-9(P<0.05),并抑制AIF核转位。综上表明,Fas通过调控线粒体通路参与镉致PC12细胞凋亡。  相似文献   

11.
To clarify the phylogenic relationship of channel catfish with other fishes, the cytochrome b (Cyt b) gene of the catfish was cloned and sequenced. Channel catfish (Ictalurus punctatus) belonging to the family Ictaluridae in the order Siluriformes showed a 78.4-87.4% similarity to all but one fish of the family Cyprinidae and river loach Crossostoma lacustre of the family Balitoridae in the order Cypriniformes in which genes had already been sequenced, and a 97.2% similarity to the goldfish (Carassius auratus) belonging to the family Cyprinidae. Within the family Cyprinidae, a 78.8-89.2% similarity to one another was recorded. In addition, the similarity rate between the family Cyprinidae and the family Balitoridae reached a value of 77.8-79.9% in the order Cypriniformes. Furthermore, in an unrooted phylogenetic tree consisting of four branches among eight fishes, channel catfish and goldfish appeared in the same branch. These results suggested that the Cyt b gene of the channel catfish in the order Siluriformes was closely related to that of a goldfish in the order Cypriniformes. The results were not agreement with the morphological classification. Genetic reclassification of the fishes may be necessary to identify the ancestor. This is the first report on the cloning and complete sequencing the Cyt b gene of the channel catfish which may contribute to the genetic reclassification of catfishes belonging to the order Siluriformes.  相似文献   

12.
为探讨我国细颈囊尾蚴种群之间的遗传相似性及与其他带科带属绦虫的亲缘关系,用线粒体细胞色素b(Cyt b)基因全序列研究了分离自我国四川和云南2省7地区猪、山羊和绵羊共33个细颈囊尾蚴的遗传变异,并用MEGA 4.0程序NJ法和PAUP 4.0程序MP法绘制种系发育树.本研究结果显示:细颈囊尾蚴分离株的Cyt b基因全长为1 068 bp,共检测到22个单倍型,单倍型间核苷酸相似性较高(97.3%~99.9%),其与带科带属其他5种绦虫的相似性均在82%以下.系统发育树显示,7个不同地域的细颈囊尾蚴聚为一支,分为3个亚群,且与地理区域、宿主没有直接的相关性,呈现混杂的分布格局,未形成明显的地理分支或宿主分支.研究结果表明:细颈囊尾蚴Cytb基因存在一定的遗传差异,但种内相对保守,与其他带科绦虫种间差异较大,故可作为种间遗传变异研究的标记,并为细颈囊尾蚴的种群遗传学研究及其与其他带科绦虫病的鉴别诊断的建立奠定基础.  相似文献   

13.
Cytopathic bovine viral diarrhoea viruses (cp BVDV) induce apoptosis in permissible cell cultures via the intrinsic pathway, which involves the mitochondria as key organelles. An important event is the irreversible opening of the permeability transition pore (PTP) and the breakdown of the transmembrane potential DeltaPsi(m). The resulting release of cytochrome C from the mitochondria serves as a trigger to form the apoptosome which then leads to caspase activation and cell death. In contrast, noncytopathic (ncp) BVDV do not seem to affect cells in vivo or in vitro, suggesting that they inhibit apoptosis. Interestingly, inhibition of caspases in cells infected with cp BVDV delayed the apoptotic cascade but did not prevent the cytopathic effect (CPE). This suggests that the induction of apoptosis and the processes finally leading to the CPE may proceed separately, implying that the inhibition of apoptosis by ncp BVDV has to start earlier in the cascade. In this study we show that in fact apoptosis inhibition in cells infected with ncp BVDV must occur at the mitochondrial level, before the activation of the caspase cascade occurs. To elucidate the role of mitochondria after infection of cells with ncp BVDV, expression of Bcl-2 and Bax were analysed. It was shown that while Bax expression was not affected, the anti-apoptotic Bcl-2 protein was upregulated, presumably suppressing initiation of cell death and enabling persistent infection in vitro.  相似文献   

14.
OBJECTIVE: To determine the maximum tolerated dose (MTD) of cisplatin administered with piroxicam, the antitumor activity and toxicity of cisplatin combined with piroxicam in dogs with oral malignant melanoma (OMM) and oral squamous cell carcinoma (SCC), and the effects of piroxicam on the pharmacokinetics of cisplatin in dogs with tumors. DESIGN: Prospective nonrandomized clinical trial. ANIMALS: 25 dogs. PROCEDURE: Dogs were treated with a combination of cisplatin (escalating dose with 6 hours of diuresis with saline [0.9% NaCI] solution) and piroxicam (0.3 mg/kg 10.14 mg/lb], PO, q 24 h).The initial cisplatin dose (50 mg/m2) was increased by 5 mg/m2 until the MTD was reached. Tumor stage and size were determined at 6-week intervals during treatment. The pharmacokinetics of cisplatin were determined in dogs receiving a combination of cisplatin and piroxicam during the clinical trial and dogs that were treated with cisplatin alone. RESULTS: 11 dogs with OMM and 9 dogs with SCC were included in the clinical trial. The MTD of cisplatin when administered in combination with piroxicam was 50 mg/m2. Tumor remission occurred in 5 of 9 dogs with SCC and 2 of 11 dogs with OMM. The most common abnormality observed was renal toxicosis. Clearance of cisplatin in dogs that were treated with cisplatin alone was not significantly different from that in dogs treated with a combination of cisplatin and piroxicam. CONCLUSIONS AND CLINICAL RELEVANCE: Cisplatin administered in combination with piroxicam had antitumor activity against OMM and SCC. The level of toxicity was acceptable, although renal function must be monitored carefully.  相似文献   

15.

Background

Head and neck cancers (HNC) are relatively common and often very serious diseases in both dogs and humans. Neoplasms originating in the head and neck region are a heterogeneous group. HNC often has an unfavourable prognosis and the proximity of the tissue structures renders extirpation of tumours with sufficient margins almost incompatible with preservation of functionality. In humans oral malignant melanoma (OMM) is extremely rare, but represents a particular challenge since it is highly aggressive as is the canine counterpart, which thus may be of interest as a spontaneous animal model.

Methods

Canine cases entered in the Danish Veterinary Cancer Registry (DVCR) from May 15th 2005 through February 29th 2008 were included in this study. Fisher''s exact test was used to compare proportions of HNC in dogs and humans as well as proportions of surgically treated cases of OMM and squamous cell carcinomas (SCC). Also the proportions of benign and malignant neoplasms of different locations in dogs were compared using Fisher''s exact test.

Results

A total of 1768 cases of neoplasias (679 malignant, 826 benign, 263 unknown) were submitted. Of all neoplasias HNC accounted for 7.2% (n = 128). Of these, 64 (50%) were malignant and 44 (34%) benign. The most common types of malignant neoplasia were SCC (18; 28% of malignant), OMM (13; 20% of malignant), soft tissue sarcoma (11; 17% of malignant) and adenocarcinoma (5; 11% of malignant). The most common types of benign neoplasms were adenoma (7; 16% of benign), polyps (6; 14% of benign) and fibroma (5; 11% of benign).

Conclusions

In the current study, the proportion of neoplasia in the head and neck region in dogs in Denmark was similar to other canine studies and significantly more common than in humans with a large proportion of malignancies. Spontaneous HNC in dogs thus, may serve as a model for HNC in humans.Canine OMM is a spontaneous cancer in an outbred, immune-competent large mammal population and could be a clinical model for OMM in humans.  相似文献   

16.
Oral malignant melanoma (OMM) in the dog is often locally aggressive with a high metastatic potential and there are few treatment options that have been demonstrated to improve outcome of this disease. The purpose of this study was to determine whether adjunctive treatment with the Oncept melanoma vaccine affected the outcome of dogs with OMM that had achieved loco‐regional cancer control. Medical records from 45 dogs that presented to the Animal Cancer and Imaging Center were reviewed, including 30 dogs with stage II and III disease. Dogs that received the vaccine did not achieve a greater progression‐free survival, disease‐free interval or median survival time than dogs that did not receive the vaccine.  相似文献   

17.
Methods for cell cycle synchronization of mouse fetal fibroblast cells (MFFCs) were first selected and optimized. When MFFCs were cooled at 5 C for different periods of time, the highest percentage of cells at the G0/G1 phase (75.4+/-2.9%), with 3.5+/-0.3% of apoptotic cells, was achieved after 5 h of treatment. Extended cooling increased the number of apoptotic cells significantly. When MFFCs were treated with different concentrations of roscovitine (ROS) for different periods of time, the highest percentage of G0/G1 cells (83.5+/-1.8%), with 9.2+/-0.6% apoptotic cells, was obtained after exposure to 10 microM ROS for 24 h. When the cells were cooled at 5 C for 5 h followed by incubation in 10 microM ROS for 12 h, 83.6+/-1.9% were synchronized at the G0/G1 stage, with 3.6% undergoing apoptosis. Cell cycle progression was then observed after release of the MFFCs from different synchronization blocks. The highest percentages of S and G2/M cells (81% and 75%) were achieved at 12 and 20 h, respectively, after release of the MFFCs from the cooling plus ROS treatment, and these percentages were significantly higher than those obtained after release from the cooling or ROS alone blocks. Finally, MFFCs were transfected with pEGFP-N1 plasmid at the peak of the G0/G1, S, and G2/M phases, respectively, after release from the different blocks and both the transient and stable transfection efficiencies were determined. The GFP gene expression was greatly enhanced when transfection was performed at the time when most cells were at the G2/M stage after release from cooling, ROS alone, and cooling plus ROS treatments. Statistical analysis revealed a close correlation between the rate of G2/M cells and the transient and stable GFP gene expression efficiencies. Together, the results indicated that (a) the best protocol for cell cycle synchronization of MFFCs was a 5-h cooling at 5 C followed by incubation in 10 microM ROS for 12 h which produced both a high rate of synchronization in the G0/G1 phase with acceptable apoptosis and a high rate of G2/M cells after release; and (b) that the cell cycle status had marked effects on the efficiency of liposome-mediated transfection in MFFCs, with the highest transfection efficiency obtained in cells at the G2/M stage.  相似文献   

18.
为了深入认识家蚕微孢子虫高分子量蛋白的主要组成,我们采用LC-MS/MS技术鉴定分析玻璃珠破碎法提取的家蚕微孢子虫总蛋白中85kD以上两条主要蛋白带。我们从H1带(位于150~200kD之间)中成功鉴定出16个蛋白,包括极管蛋白3(PTP3)、极管蛋白2(PTP2)、真核蛋白翻译起始因子(eIF2C2)、延伸因子(EF1-alpha、EF2)、肌动蛋白(actin)等。这暗示两种结构蛋白PTP3与PTP2以及蛋白翻译延伸因子(EF1-alpha、EF2)与肌动蛋白(actin)可能各形成一个复合体。并且用SDS或β-巯基乙醇处理时,这两个复合物是稳定的,表明这些复合物的相互作用力不仅仅是通过二硫键。H2带(85~100kD)鉴定出主要集中在水解酶、蛋白合成与折叠、细胞结构、运动四个方面的20多个的蛋白。从两条蛋白带鉴定出PTP3与PTP2、三磷酸腺苷酶(ATPase)或过渡期内质网三磷酸腺苷酶(ATPase-TER94)、蛋白翻译因子(eIF2C、EF1-alpha、EF2)、HSP70、Actin、M1家族氨肽酶1(M1family aminopeptidase)6类蛋白。基于蛋白分子质量分析,暗示在家蚕微孢子虫中,这6类蛋白都可能是以复合体形式呈现的。研究结果丰富家蚕微孢子虫高分子量蛋白的数据,同时,为研究非二硫键间的蛋白互作提供了有价值的研究线索。  相似文献   

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