首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到17条相似文献,搜索用时 187 毫秒
1.
叠氮钠损伤的神经元内硫氧还蛋白mRNA水平的变化   总被引:5,自引:0,他引:5  
氧化应激与许多神经退变病有关,而线粒体损伤是氧化应激加剧的重要原因。本文通过细胞活性检测(MTT法)、形态学观察,分析NaN3对原代培养神经元的损伤作用,并通过RT-PCR半定量检测NaN3损伤后神经元内硫氧还蛋白(Thioredoxin,Trx)mRNA水平的改变,以阐明这一重要的氧还调节蛋白在神经元损伤过程中的作用。实验表明NaN3以浓度和时间依赖方式损伤神经元,降低Trx表达水平。提示:神经元内呼吸链受损引起Trx表达减少,从而减弱神经元内氧还调节功能,最终引起神经元损伤、死亡。  相似文献   

2.
H2O2诱导的线粒体损伤神经元内硫氧还蛋白mRNA水平的变化   总被引:3,自引:0,他引:3  
线粒体缺陷和氧化应激参与了神经退行性疾病的发病机制。叠氮钠(NaN3)是线粒体细胞色素C氧化酶(COX)的特异性抑制剂,能诱导线粒体缺陷。本实验通过细胞活性检测(MTT法),形态学观察,分析H2O2对原代培养的正常神经元及NaN3诱导的线粒体缺陷神经元的损伤作用的差异。并通过RT-PCR半定量法检测H2O2损伤后两类神经元内硫氧还蛋白(Thioredoxin,Trx)mRNA水平的变化,以阐明细胞内这一重要氧化还原调节蛋白在神经元损伤时的作用机制。实验表明,在正常神经元内,H2O2的损伤对Trx表达量的改变似乎不明显;而线粒体缺陷神经元内Trx的表达量下降,且对于H2O2的损伤具有浓度、时间依赖性。提示:在线粒体功能缺陷神经元中,Trx似乎发挥更重要的作用。  相似文献   

3.
线粒体缺陷和氧化应激参与了神经退行性疾病的发病机制.叠氮钠(NaN3)是线粒体细胞色素C氧化酶(COX)的特异性抑制剂,能诱导线粒体缺陷.本实验通过细胞活性检测(MTT法),形态学观察,分析H2O2对原代培养的正常神经元及NaN3诱导的线粒体缺陷神经元的损伤作用的差异.并通过RT-PCR半定量法检测H2O2损伤后两类神经元内硫氧还蛋白(Thioredoxin,Trx)mRNA水平的变化,以阐明细胞内这一重要氧化还原调节蛋白在神经元损伤时的作用机制.实验表明,在正常神经元内,H2O2的损伤对Trx表达量的改变似乎不明显;而线粒体缺陷神经元内Trx的表达量下降,且对于H2O2的损伤具有浓度、时间依赖性.提示在线粒体功能缺陷神经元中,Trx似乎发挥更重要的作用.  相似文献   

4.
目的:明确硫氧还蛋白(Thioredoxin,Trx)通过自噬调节对大鼠心脏微血管内皮细胞损伤的保护作用及相关机制。方法:分离成年大鼠心脏微血管内皮细胞并分为:(1)正常对照组;(2)高糖组;(3)高糖+Trx组;(4)高糖+Trx+Ad-sh Sirt3组;(5)高糖+Trx+Ad-sh P53组;(6)高糖+DMSO空载组。通过In Vitro Vascular Permeability Assay Kit检测单层心脏微血管内皮细胞通透性,TUNEL染色检测细胞凋亡,Western blot法检测Sirt3、P53、Atg5、LC3BI/II等相关自噬相关信号通路关键蛋白的表达水平。结果:与正常对照组相比,高糖引起单层心脏微血管内皮细胞通透功能损伤,增加细胞凋亡,抑制自噬,且Sirt3、Atg5、LC3BI/II表达下降而P53表达上升;给予Trx可以上调Sirt3、Atg5、LC3BI/II蛋白表达水平,抑制P53表达,并显著减轻上述高糖引起的细胞损伤;但是,分别干扰Sirt3和P53表达后,Trx的作用明显减弱。结论:Trx通过Sirt3-P53信号通路促进心脏微血管内皮细胞自噬,降低细胞凋亡,改善高糖诱发的大鼠心脏微血管内皮细胞损伤。  相似文献   

5.
脑卒中是导致中老年人群死亡最主要原因之一,其具有较高的致死率和致残率,且每年的发病率呈逐年上升的趋势,严重危害人类的生命和健康,因此寻找有效的诊断及治疗脑卒中的靶点具有重要意义。硫氧还蛋白(Trx)是细胞内主要的硫醇还原剂,通过调节细胞内氧化还原状态,参与细胞内多种信号通路转导过程,具有二硫化物还原酶活性,通过抗氧化效应,减轻脑卒中后神经元氧化应激损伤。硫氧还原蛋白相互作蛋白(TXNIP)是Trx的内源性抑制剂,通过绑定/抑制Trx的活性,破坏细胞内氧化还原平衡,促进氧化应激,而抑制或敲除TXNIP具有明显的神经保护作用。最新研究表明Trx/TXNIP可经多种途径参与脑卒中病理生理过程。本文通过分析Trx和TXNIP的研究现状,以及探讨Trx系统在中枢神经系统中的定位和Trx系统在缺血性脑卒中的研究进展,展望Trx/TXNIP参与脑卒中的病理生理过程的信号途径,拟对Trx/TXNIP在脑卒中的作用机制进行综述,为脑卒中的治疗提供新思路。  相似文献   

6.
过度氧化应激是诱发许多神经退变病的重要因素。叠氮钠(NaN3)是线粒体有氧呼吸链细胞色素c氧化酶(COX)的特异性抑制剂,过氧化氢(H2O2)释放氧自由基造成氧化损伤,两者都可以用于氧化应激情况下神经元损伤模型的建立。硫氧还蛋白还原酶(thioredoxin reductase,TR)特异性的还原氧化型的硫氧还蛋白(thioredoxin,TRx),调节细胞中氧化还原的平衡。现以不同浓度NaN3或H2O2,处理人神经母细胞瘤细胞(SH-SY5Y细胞),建立损伤模型。通过MTT法、形态学方法检测SH-SY5Y细胞损伤程度。同时,通过Western blot定量法、免疫细胞化学法,检测损伤的SH-SY5Y细胞中TR含量的改变,观察TR在胞内的分布。实验表明,NaN3、H2O2,均以浓度依赖方式损伤SH-SY5Y细胞;TR分布于SH-SY5Y细胞的胞浆,表明TR是一种分泌蛋白,损伤后分布无明显变化。但一定浓度的NaN3作用后3h,胞内TR水平显著降低,即神经系统内呼吸链受损可抑制TR的表达,为神经退变病的防治提供了新的思路。  相似文献   

7.
观察鱼藤酮诱导的线粒体轻度损伤细胞氧化应激时硫氧还蛋白转录水平的变化,探讨细胞氧化损伤的可能机制。通过荧光素发光法检测ATP生成、细胞内活性氧(ROS)水平的变化,流式细胞术检测线粒体膜电位,了解低剂量鱼藤酮对线粒体功能的影响;继而用H2O2诱导细胞氧化损伤,MTT法检测细胞活性,观察正常及线粒体缺陷细胞氧化应激时,胞内硫氧还蛋白(Trx)mRNA水平的变化。结果表明,鱼藤酮以剂量依赖方式抑制线粒体ATP的产生、降低线粒体膜电位,而细胞内ROS水平增高;当线粒体损伤细胞氧化应激时胞内Trx mRNA水平降低,提示鱼藤酮诱导线粒体轻度损伤细胞抗氧化能力降低与Trx转录受到抑制有关。  相似文献   

8.
硫氧还蛋白与神经退行性病变   总被引:2,自引:0,他引:2  
神经退行性病变与胞内氧化还原失衡诱发的神经元损伤,死亡有密切关系,硫氧还原白参与维持胞内氧化还原平衡,在氧化应激中起重要的氧还调节作用,因此成为对抗神经退行性病变的重要蛋白之一。硫氧还蛋白可能通过激活某些有氧还调节功能的酶,清除自由基和调节细胞内分子通道等发挥对神经元的保护作用,对转基因动物的研究,进一步提示硫氧还蛋白在神经退行性病变的防治中可能发挥重要作用。  相似文献   

9.
硫氧还蛋白系统是由硫氧还蛋白(thioredoxin,Trx)、硫氧还蛋白还原酶(thioredoxin reductase,TrxR)和还原型辅酶Ⅱ(NADPH)组成的多功能小分子蛋白系统,广泛表达的硫氧还蛋白作为蛋白质二硫键的还原酶,它参与很多生理过程,并发挥重要生物学功能,包括调节机体的氧化还原反应、抑制细胞凋亡、调节转录因子DNA结合活性以及免疫应答等,其中一重要作用是参与调节细胞氧化还原状态以对抗氧化应激。因此在一些炎症性疾病如慢性阻塞性肺疾病、急性呼吸窘迫综合征、肺间质疾病、哮喘、肺结节病等的发生发展中扮演重要角色,本文对硫氧还蛋白系统在慢性阻塞性肺疾病中的抗氧化作用作一综述。  相似文献   

10.
秦童  黄震 《植物学报》2019,54(1):119-132
硫氧还蛋白(Trx)属于巯基-二硫键氧化还原酶家族, 通过作用于底物蛋白侧链2个半胱氨酸残基之间的二硫键(还原、异构和转移)来调控胞内蛋白的结构和功能。叶绿体Trx系统包括Trx及Trx类似蛋白、铁氧还蛋白(Fd)依赖的硫氧还蛋白还原酶(FTR)和还原型烟酰腺嘌呤二核苷磷酸(NADPH)依赖的硫氧还蛋白还原酶C (NTRC)。除了基质蛋白酶类活性变化及叶绿体蛋白的转运受Trx系统调控之外, 在叶绿体中还存在1条跨类囊体膜的还原势传递途径, 把基质Trx的还原势经跨膜转运蛋白介导, 最终传递给类囊体腔蛋白。FTR和NTRC共同作用维持叶绿体的氧化还原平衡。该文对叶绿体硫氧还蛋白系统的调节机制进行了综述, 同时讨论了叶绿体硫氧还蛋白系统对维持植物光合效率的重要意义。  相似文献   

11.
In this study, we first developed an in vitro model of neuron with mitochondrial dysfunction, based on sodium azide (NaN(3))-induced inhibition of cytochrome c oxidase (complex IV) that is reduced in post-mortem AD brains, and then investigated the role of Trx expression in response of neurons with mitochondrial dysfunction to oxidative stress. We found that neurons treated with sub-threshold concentration (8mM) of NaN(3) have mitochondrial dysfunction and that thioredoxin (Trx) mRNA and protein level decreased in neurons with mitochondrial dysfunction though no significant change in the viability. When exposed to extracellular H(2)O(2), neurons with mitochondrial dysfunction were significantly more vulnerable than control neurons. Trx mRNA and protein levels in neurons with mitochondrial dysfunction decreased in a dose- and time-dependent manner (mRNA: 25-150 microM H(2)O(2) for 1h and 50 microM H(2)O(2) for 1-3h; protein: 25-150 microM H(2)O(2) for 1h and 50 microM H(2)O(2) for 1-4h), while those in control neurons had no significant changes (50-250 microM H(2)O(2) for 1h). The data implied that vulnerability of neurons with mitochondrial dysfunction to oxidative stress is associated with down-regulation of thioredoxin.  相似文献   

12.
Increasing evidence suggests that Alzheimer’s disease is associated with mitochondrial dysfunction and oxidative damage. To develop a cellular model of Alzheimer’s disease, we investigated the effects of thioredoxin (Trx) expression in the response to mitochondrial dysfunction-enhanced oxidative stress in the SH-SY5Y human neuroblastoma cells. Treatment of SH-SY5Y cells with 15 mM of NaN3, an inhibitor of cytochrome c oxidase (complex IV), led to alteration of mitochondrial membrane potential but no significant changes in cell viability. Therefore, cells were first treated with 15 mM NaN3 to induce mitochondrial dysfunction, then, exposed to different concentrations of H2O2. Cell susceptibility was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and morphological observation. Expressions of Trx mRNA and protein were determined by RT-PCR; and Western-blot analysis, respectively. It was found that the SH-SY5Y cells with mitochondrial impairment had lower levels of Trx mRNA and protein, and were significantly more vulnerable than the normal cells after exposure to H2O2 while no significant changes of Trx mRNA and protein in SH-SY5Y cells exposed to H2O2 but without mitochondrial complex IV inhibition. These results, together with our previous study in primary cultured neurons, demonstrated that the increased susceptibility to oxidative stress is induced at least in part by the down-regulation of Trx in SH-SY5Y human neuroblastoma cells with mitochondrial impairment and also suggest the mitochondrial dysfunction-enhanced oxidative stress could be used as a cellular model to study the mechanisms of Alzheimer’s disease and agents for prevention and treatment.  相似文献   

13.
Sheng R  Liu XQ  Zhang LS  Gao B  Han R  Wu YQ  Zhang XY  Qin ZH 《Autophagy》2012,8(3):310-325
Recent studies have suggested that autophagy plays a prosurvival role in ischemic preconditioning (IPC). This study was taken to assess the linkage between autophagy and endoplasmic reticulum (ER) stress during the process of IPC. The effects of IPC on ER stress and neuronal injury were determined by exposure of primary cultured murine cortical neurons to 30 min of OGD 24 h prior to a subsequent lethal OGD. The effects of IPC on ER stress and ischemic brain damage were evaluated in rats by a brief ischemic insult followed by permanent focal ischemia (PFI) 24 h later using the suture occlusion technique. The results showed that both IPC and lethal OGD increased the LC3-II expression and decreased p62 protein levels, but the extent of autophagy activation was varied. IPC treatment ameliorated OGD-induced cell damage in cultured cortical neurons, whereas 3-MA (5-20 mM) and bafilomycin A 1 (75-150 nM) suppressed the neuroprotection induced by IPC. 3-MA, at the dose blocking autophagy, significantly inhibited IPC-induced HSP70, HSP60 and GRP78 upregulation; meanwhile, it also aggregated the ER stress and increased activated caspase-12, caspase-3 and CHOP protein levels both in vitro and in vivo models. The ER stress inhibitor Sal (75 pmol) recovered IPC-induced neuroprotection in the presence of 3-MA. Rapamycin 50-200 nM in vitro and 35 pmol in vivo 24 h before the onset of lethal ischemia reduced ER stress and ischemia-induced neuronal damage. These results demonstrated that pre-activation of autophagy by ischemic preconditioning can boost endogenous defense mechanisms to upregulate molecular chaperones, and hence reduce excessive ER stress during fatal ischemia.  相似文献   

14.
《Autophagy》2013,9(3):310-325
Recent studies have suggested that autophagy plays a prosurvival role in ischemic preconditioning (IPC). This study was taken to assess the linkage between autophagy and endoplasmic reticulum (ER) stress during the process of IPC. The effects of IPC on ER stress and neuronal injury were determined by exposure of primary cultured murine cortical neurons to 30 min of OGD 24 h prior to a subsequent lethal OGD. The effects of IPC on ER stress and ischemic brain damage were evaluated in rats by a brief ischemic insult followed by permanent focal ischemia (PFI) 24 h later using the suture occlusion technique. The results showed that both IPC and lethal OGD increased the LC3-II expression and decreased p62 protein levels, but the extent of autophagy activation was varied. IPC treatment ameliorated OGD-induced cell damage in cultured cortical neurons, whereas 3-MA (5–20 mM) and bafilomycin A1 (75–150 nM) suppressed the neuroprotection induced by IPC. 3-MA, at the dose blocking autophagy, significantly inhibited IPC-induced HSP70, HSP60 and GRP78 upregulation; meanwhile, it also aggregated the ER stress and increased activated caspase-12, caspase-3 and CHOP protein levels both in vitro and in vivo models. The ER stress inhibitor Sal (75 pmol) recovered IPC-induced neuroprotection in the presence of 3-MA. Rapamycin 50–200 nM in vitro and 35 pmol in vivo 24 h before the onset of lethal ischemia reduced ER stress and ischemia-induced neuronal damage. These results demonstrated that pre-activation of autophagy by ischemic preconditioning can boost endogenous defense mechanisms to upregulate molecular chaperones, and hence reduce excessive ER stress during fatal ischemia.  相似文献   

15.
Of the GTPases involved in the regulation of the fusion machinery, mitofusin 2 (Mfn2) plays an important role in the nervous system as point mutations of this isoform are associated with Charcot Marie Tooth neuropathy. Here, we investigate whether Mfn2 plays a role in the regulation of neuronal injury. We first examine mitochondrial dynamics following different modes of injury in cerebellar granule neurons. We demonstrate that neurons exposed to DNA damage or oxidative stress exhibit extensive mitochondrial fission, an early event preceding neuronal loss. The extent of mitochondrial fragmentation and remodeling is variable and depends on the mode and the severity of the death stimuli. Interestingly, whereas mitofusin 2 loss of function significantly induces cell death in the absence of any cell death stimuli, expression of mitofusin 2 prevents cell death following DNA damage, oxidative stress, and K+ deprivation induced apoptosis. More importantly, whereas wild-type Mfn2 and the hydrolysis-deficient mutant of Mfn2 (Mfn2(RasG12V)) function equally to promote fusion and lengthening of mitochondria, the activated Mfn2(RasG12V) mutant shows a significant increase in the protection of neurons against cell death and release of proapoptotic factor cytochrome c. These findings highlight a signaling role for Mfn2 in the regulation of apoptosis that extends beyond its role in mitochondrial fusion.  相似文献   

16.
Our previous studies have demonstrated that oxysophoridine (OSR) has protective effects on cerebral neurons damage in vitro induced by oxygen and glucose deprivation. In this study, we further investigated whether OSR could reduce ischemic cerebral injury in vivo and its possible mechanism. Male Institute of cancer research mice were intraperitoneally injected with OSR (62.5, 125 and 250 mg/kg) for seven successive days, then subjected to brain ischemia induced by the model of middle cerebral artery occlusion. After reperfusion, neurological scores and infarct volume were estimated. Morphological examination of tissues was performed. Apoptotic neurons were detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling staining. Oxidative stress levels were assessed by measurement of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. The expression of various apoptotic markers as Caspase-3, Bax and Bcl-2 were investigated by immunohistochemistry and Western-blot analysis. OSR pretreatment groups significantly reduced infract volume and neurological deficit scores. OSR decreased the percentage of apoptotic neurons, relieved neuronal morphological damage. Moreover, OSR markedly decreased MDA content, and increased SOD, GSH-Px activities. Administration of OSR (250 mg/kg) significantly suppressed overexpression of Caspase-3 and Bax, and increased Bcl-2 expression. These findings indicate that OSR has a protective effect on focal cerebral ischemic injury through antioxidant and anti-apoptotic mechanisms.  相似文献   

17.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号