香烟提取物对人支气管平滑肌细胞DNA的损伤作用及细胞应激的影响

目的:探讨香烟提取物(CSE)对人支气管平滑肌细胞DNA损伤和细胞应激(热休克蛋白70表达)的影响。方法:以1mL培养液中含30mL烟雾作为原液,分别以1/16、1/10、1/8、1/6和1/4浓度与正常人支气管平滑肌细胞培养3h,采用单细胞琼脂糖凝胶电泳(即彗星实验)和Western印迹技术检测细胞DNA损伤和热休克蛋白70(HSP70)的表达。结果:随着培养液中CSE浓度的增加,细胞受损的百分率(拖尾细胞百分率)及受损的程度(尾长)逐渐增加,除1/16原液外,其它与阴性对照之间均有显著差异(P＜0.05)。随着培养液中CSE浓度的改变,结果发现含1/16和1/10原液的CSE刺激后HSP70的表达有轻度增高的趋势,而含1/8原液-1/4原液的CSE刺激后,HSP70的表达逐渐降低。其中含1/6原液组和含1/4原液组与阴性对照组之间HSP70的表达有显著差异(P＜0.05)。结论:CSE可导致支气管平滑肌细胞DNA的损伤并伴有细胞保护蛋白(HSP70)合成的减少,可能与慢性阻塞性肺疾病(COPD)的发病有关。     

HBV感染者血清抗TRP-1抗体与HSP70检测及相关性分析

目的 检测HBV感染者血清抗TRP-1抗体及HSP70,并对二者的相关性进行分析.方法 选取HBV感染组血清标本88例,其中大三阳组28例,小三阳组60例;抗体阳性组标本64例,其中既往感染组32例,疫苗接种组32例;全阴性对照组64例.用ELISA法检测所有标本抗TRP-1抗体及HSP70表达水平,对各组检测结果进行统计并分析两者的相关性.结果 大三阳组、小三阳组、既往感染组、疫苗接种组、全阴性对照组血清标本中抗TRP-1抗体的OD值依次为2.071±0.574、1.855±0.873、0.166±0.068、0.220±0.048和0.260±0.034,抗TRP-1抗体阳性率分别为92.86％(26/28)、83.33％(50/60)、0％(0/32)、0％ (0/32)和0％ (0/64).HSP70检测的OD值分别为2.135±0.456、1.816±0.874、0.165±0.073、0.166±0.042和0.206±0.033,高水平的HSP70占有率分别为100％(28/28)、83.33％(50/60)、0％(0/32)、0％(0/32)和0％ (0/64).经比较HBV感染组抗TRP-1抗体与HSP70表达水平显著高于抗体组及全阴性对照组(P＜0.01).高水平的抗TRP-1抗体与HSP70表达水平呈正相关(r=0.926,P＜0.01).抗体组与全阴性对照组之间比较,差异无统计学意义(P＞0.05).结论 大部分HBV感染者体内同时存在高水平抗TRP-1抗体及HSP70,两者呈正相关,可能是该类患者黑素细胞遭受破坏的早期标志,也是继发白癜风的重要原因.     

热休克蛋白-肽复合物与肿瘤免疫

<正>热休克蛋白(heat shock protein,HSP)是一类在生物进化过程中高度保守,广泛表达于所有生命机体组织细胞并具有管家功能的蛋白质。根据分子量的差异,HSP可分为10个家族,包括HSP110/grp170、gp96/grp94、HSP90、HSP70/grp78、HSP65、HSP25/27等,每个家族有1~5个成员[1]。在正常生理状态下,HSP的结构性表达约占细胞蛋     

mGluR 1/5介导的下游信号通路

代谢型谷氨酸受体1/5(mGluR1/5)是G蛋白偶联受体家族C的重要成员之一,该受体及其介导的下游信号在调节神经系统的正常生理功能起着非常重要作用,并与相关神经系统退行性疾病密切相关。文章介绍了mGluR1/5所介导的信号通路、信号通路调控的分子机制以及其他GPCR受体的相互作用对信号共同调节的分子机制等方面最新研究进展。     

大脑皮层I型mGluRs参与突触可塑性调控的机制

<正>I型代谢型谷氨酸受体(metabotropic glutamate receptors,mGluRs)在中枢神经系统(central nervou sysytem,CNS)中参与了很多重要的生理功能,如调控兴奋性神经信号传导,参与痛觉、痒、以及药物成瘾的产生,并且与癫痫、脑缺血、帕金森病等神经系统疾病有密切联系~[1]。然而,以I型mGluRs为药物靶点的药物并不广泛,主要是其作用的机制并不清楚。而研究mGluR1/5在神经系统中发挥功能的作用机制,     

The polymorphism of heat shock protein 70 genes in Chinese Han population in Fujian province

Heat shock protein 70 (HSP70) genes are themost important and conserve gene members intheheat shock protein family,and locate in an areaadjacent tothe TNFgenesinthe classⅢregionofmajor histocompatibilitycomplex(MHC) .Its geneproductsHSP70proteins are encoded by 3 differ-ent genes ,HSP70-1,HSP70-2andHSP70-hom.Previous studies showed that three kinds ofpolymorphisms existin3loci of thesethree genes ,i .e .+190 G/CBsrBⅠrestrictionsite onHSP70-1, +1267 A/GPstⅠrestriction site onHSP…     

榄香烯或热休克对人肝癌细胞HepG2HSP70膜表达及多种HSP基因表达的影响

目的 :研究榄香烯或热休克对人肝癌细胞HepG2 HSP70膜表达及多种HSP基因表达的影响。方法 :免疫荧光和FCM观察榄香烯 (5 0 μg ml,1h)或热休克 (42℃ ,1h)处理后肿瘤细胞HSP70的膜表达 ,放线菌素D阻断基因转录。应用人类基因表达谱芯片分析经榄香烯或热休克处理的人肝癌细胞HepG2 多种热休克蛋白基因及与热休克蛋白调控相关基因表达谱的改变。结果 :榄香烯或热休克处理 1h后 ,肿瘤细胞膜表面HSP70的表达均有增高 ,而以榄香烯处理为明显 ,放线菌素D的加入在两种处理中均增高了HSP70膜表达的阳性率。两种处理均使细胞的HSP70HP(EnhancerProtein)基因表达增高 ,而以热休克处理为更明显 ,HSPA2的表达均有所下降 ,也以热休克处理更明显 ,HSF1基因在热休克处理为上调 ,而在榄香烯处理则为下调 ,与肿瘤免疫密切相关的HSP70、HSP72、HSP75及HSP90、gp96基因的表达则没有变化。结论 :榄香烯较热休克处理早期能更多地促进HepG2 细胞HSP70的膜表达 ,其机制可能是与其改变胞内已存在的HSP70的分布 ,和 或促进HSP70mRNA的翻译有关。两种处理均能改变与HSPs调控相关基因的表达 ,并可引起HSPA2基因表达下调。     

细胞外HSP70/HSP70-PCs对人肝癌HepG2细胞上皮-间充质转化的影响及机制研究

 目的：探讨细胞外热休克蛋白70(HSP70)/HSP70肽复合物(HSP70-PCs)对肝癌细胞上皮-间充质转化(EMT)的影响和可能机制。方法：将HepG2细胞分为3组：正常对照组、HSP70/HSP70-PCs组（终浓度2 mg/L）和LY294002+HSP70/HSP70-PCs组。应用real-time RT-PCR与Western blotting法检测上皮细胞表面标志E-cadherin和间质细胞表面标志α-平滑肌肌动蛋白（α-SMA）的表达变化,以及磷脂酰肌醇3-激酶（PI3K）和缺氧诱导因子1α(HIF1-α)的表达变化。结果：细胞外HSP70/HSP70-PCs可以促进HepG2细胞EMT的发生。HepG2细胞的EMT过程伴随HIF-1α和PI3K表达增加。应用LY294002阻断PI3K后,HepG2细胞没有发生EMT,同时细胞外HSP70/HSP70-PCs上调HIF-1α表达的作用消失。结论：细胞外HSP70/HSP70-PCs可以通过PI3K/HIF-1α促进肝癌细胞发生EMT。     

热休克蛋白70诱导抗肿瘤免疫的机制研究

目的　研究肿瘤热休克蛋白 70 (HSP70 )诱导的抗肿瘤免疫产生的机制。方法　用液相色谱法提纯小鼠肿瘤细胞株中的HSP70。通过动物实验观察HSP70的抗肿瘤作用 ,并用流式细胞技术测定HSP70免疫后小鼠外周血中T细胞亚群的变化。用ELISA法测定HSP70免疫后小鼠体内细胞因子的水平。结果　用HSP70免疫后 ,小鼠外周血中CD8+T细胞及几种主要Th1型细胞因子 (IL 2、TNF α、TNF β和IFN γ)均升高 ,与对照组相比较 ,差异显著 (P <0 .0 1)。结论　HSP70免疫后 ,小鼠外周血中CD8+ T细胞及Th1型细胞因子均有明显升高。此作用可能是其诱导特异性抗肿瘤免疫的重要机制     

HSP70多肽复合物修饰DCs疫苗抗胰腺癌荷瘤小鼠的实验研究

目的:探讨负载热休克蛋白70多肽复合物(HSP70-PC)抗原的树突状细胞(DCs)疫苗对胰腺癌荷瘤小鼠的免疫治疗作用.方法:采用低渗裂解、ConA-Sepharose亲和层析及ADP-Agarose亲和层析法,从小鼠胰腺癌(MPC83)肿瘤组织中纯化HSP70-PC,修饰小鼠骨髓来源的树突状细胞(DCs),制备树突状细胞HSP70多肽肿瘤疫苗,用MTT法检测混合淋巴细胞反应(MLR)中HSP70-PC致敏DC对CTL的增殖及活化效果;建立MPC83荷瘤小鼠模型,观察树突状细胞HSP70多肽肿瘤疫苗对荷瘤小鼠治疗的效果和小鼠存活期.结果:经上述方法分离、纯化获得了较高纯度的HSP70-PC蛋白质;HSP70-PC在1.5～2.0 μg/ml范围内可达到刺激树突状细胞最强效果,用HSP70-PC修饰的DCs能增强T细胞的增殖和活化能力;应用树突状细胞HSP70多肽肿瘤疫苗治疗荷瘤小鼠能显著抑制荷瘤小鼠肿瘤的生长,延长荷瘤小鼠存活期.结论:采用低压亲和层析柱可从胰腺癌瘤块中获得较高纯度HSP70多肽复合物,其修饰的DCs疫苗用于荷瘤小鼠免疫治疗有显著疗效,为临床胰腺癌生物免疫治疗奠定基础.     

Mortalin is regulated by APOE in hippocampus of AD patients and by human APOE in TR mice

Mortalin is a chaperone protein associated with cell survival, stress response, intracellular trafficking, control of cell proliferation, mitochondrial biogenesis, and cell fate determination. Human APOE targeted replacement (TR) mice have been used to elucidate the role of APOE4 in Alzheimer's disease (AD), since these animals express the APOE4 gene without the classical pathological signatures of AD. Using proteomics we found that mortalin isoforms are differentially expressed in the hippocampus of APOE4 TR mice compared with the APOE3 (control) TR mice. We also observed that these mortalin isoforms are differentially phosphorylated. Then we studied mortalin expression in patients with AD (genotypes APOE 3/3 and APOE 4/4) compared with patients without AD (genotype APOE 3/3). We observed that mortalin isoforms are also differentially expressed in the hippocampi of patients with AD, and that the expression of these mortalin isoforms is regulated by the APOE genotype. We propose that the differential regulation of mortalin in AD and by the APOE genotype is a cellular defense mechanism responding to increases in oxidative stress.     

Mortalin is Expressed by Astrocytes and Decreased in the Midbrain of Parkinson's Disease Patients

Mortalin, an essential mitochondrial chaperone protein, has previously been implicated in the pathogenesis of a wide array of diseases, including neurodegenerative conditions such as Parkinson's disease (PD) and Alzheimer's disease. Previous reports have consistently described mortalin protein levels to be lower in the brain tissue of patients with neurodegenerative disease, with expression demonstrated to be lower in neurons of post‐mortem PD brain specimens. However, to date, mortalin expression has not yet been evaluated in astrocytes of post‐mortem brain tissue from either normal or PD subjects. Mortalin expression was demonstrated in mouse primary astrocyte cultures by Western blot and quantitative polymerase chain reaction (PCR). Furthermore, confocal microscopy studies in human post‐mortem tissue indicated co‐localization of mortalin within astrocytes. Utilizing a quantitative immunofluorescence staining approach, the protein was found to be moderately reduced (～35%) in this cell type in the substantia nigra pars compacta, but not structures of the corpus striatum, in PD subjects as compared to age‐/gender‐matched controls. These findings highlight the potential contribution of disrupted astroglial function in the pathogenesis of PD.     

Mortalin mutations are not a frequent cause of early-onset Parkinson disease

Dysfunctional mitochondria and the mitochondrial chaperone mortalin (HSPA9, GRP75) have been implicated in the pathogenesis of Parkinson disease (PD). We screened 139 early-onset PD (EOPD) patients for mutations in mortalin revealing one missense change (p.L358P) that was absent in 279 control individuals. We also found one additional missense variant among the controls (p.T333K). Although both missense changes were predicted to be disease causing, we detected no differences in subcellular localization, mitochondrial morphology, or respiratory function between wild-type and mutant mortalin. These findings suggest that variants in mortalin (1) are not a major cause of EOPD; (2) occur in patients and controls; and (3) do not lead to functional impairment of mitochondria.     

Inhibition of mitochondrial permeability transition pore opening is involved in the protective effects of mortalin overexpression against beta-amyloid-induced apoptosis in SH-SY5Y cells

Mortalin (mtHsp70) is a mitochondrial heat shock protein critical for maintaining the functional integrity of mitochondrial proteins. Our previous study demonstrated that mortalin overexpression protected against Aβ-induced neurotoxicity through a mitochondria-dependent mechanism, but the molecular details remained unclear. Recent biochemical studies implicate opening of the mitochondrial permeability transition pore (mPTP) in Aβ-mediated mitochondrial dysfunction. The present study investigated the effect of mortalin overexpression on Aβ-induced mPTP activation and ensuing neuronal apoptosis. Mortalin overexpression inhibited mPTP activation and protected SH-SY5Y neurons against Aβ-induced apoptosis. Compared to controls, neurons overexpressing mortalin also demonstrated superior intracellular free calcium regulation, lower mitochondrial reactive oxygen species generation, and decreased Bax/Bcl-2 ratios in response to Aβ treatment. Mortalin overexpression suppressed activation of the mitochondrial apoptotic cascade as demonstrated by inhibition of cytochrome c release and caspase-3 activation. Our results indicate that the cytoprotective efficacy of mortalin under Aβ-induced stress is mediated, at least in part, by inhibition of mPTP opening. Demonstration of the neuroprotective action of mortalin provides additional insights into the pathogenic mechanisms of Aβ toxicity and defines possible molecular targets for therapeutic intervention.     

Does perturbation in the mitochondrial protein folding pave the way for neurodegeneration diseases?

Mitochondria, which are cell compartments that are widely present in eukaryotic cells, have been shown to be involved in a variety of synthetic, metabolic, and signaling processes, thereby playing a vital role in cells. The mitochondrial unfolded protein response (mtUPR) is a response in which mitochondria reverse the signal to the nucleus and maintain mitochondrial protein homeostasis when unfolded and misfolded proteins continue to accumulate. Multiple neurodegeneration diseases, including Alzheimer's disease (AD), Parkinson’s disease (PD), and familial amyotrophic lateral sclerosis (fALS), are public health challenges. Every year, countless efforts are expended trying to clarify the pathogenesis and treatment of neurological disorders, which are associated with mitochondrial dysfunction to some extent. Numerous studies have shown that mtUPR is involved in and plays an important role in the pathogenesis of neurological disorders, but the exact mechanism of the disorders is still unclear. Further study of the process of mtUPR in neurological disorders can help us more accurately understand their pathogenesis in order to provide new therapeutic targets. In this paper, we briefly review mtUPR signaling in Caenorhabditis elegans (C. elegans) and mammals and summarize the role of mtUPR in neurodegeneration diseases, including AD, PD and fALS.     

Mortalin/GRP75 promotes release of membrane vesicles from immune attacked cells and protection from complement-mediated lysis

The membrane attack complex (MAC) of the complement system is causing membrane damage and cell death. For protection, cells have adopted several resistance mechanisms, including removal of the membrane-inserted MAC by vesiculation. To identify proteins involved in MAC vesiculation, extracellular proteins released from K562 cells in response to treatment with sub-lytic complement were separated by acrylamide gel electrophoresis and protein bands were extracted, digested into peptides and the peptides were analyzed by mass spectrometry. A 75-kDa protein that was abundant in the supernatant of complement-treated cells was identified as mortalin/GRP75. Analysis by western blotting demonstrated that as early as 5 min after exposure to sub-lytic doses of complement, mortalin was released from K562 cells. Mortalin was released after complete activation of the complement system and formation of C5b-8, and even more so when C5b-9 was formed. Other pore formers, such as streptolysin O and melittin, did not induce release of mortalin. As shown, mortalin can bind to complement C8 and C9 and is shed in vesicles containing C9 and complement MACs. Anti-mortalin antibodies reduced mortalin release from complement-treated cells and elevated the extent of cell death by complement. Inhibitors of protein kinase C and extracellular signal-regulated protein kinase also prevented mortalin release from complement-activated cells. These results suggest that mortalin/GRP75 promotes the shedding of membrane vesicles loaded with complement MAC and protects cells from complement-mediated lysis.     

Why do Alzheimer’s disease and Parkinson’s disease target the same neurons?

The puzzle is to explain how cerebral involvement in the sporadic forms of Alzheimer’s disease (AD) and Parkinson’s disease (PD) can target the same population of vulnerable neurons. These neurons are poorly-myelinated projection neurons, lack of myelin being associated with high metabolic demand, high oxygen consumption, and high baseline oxidative stress. Yet the two diseases are clearly separable, with different intracellular markers, different risk factors, and different patterns of subcortical involvement.A theory is developed to show how two different pathophysiologies can preferentially affect the same neurons. In the case of AD, the hypothesis is as follows: the so-called vascular risk factors of AD, which include hypertension, diabetes, hyperlipidemia, and smoking, are all associated with increased systemic extracellular oxidative stress. High extracellular oxidative stress synergizes with high baseline intracellular oxidative stress to cause the disease. In the case of PD, mitochondrial failure associated with normal aging leads to diminished energy production and increased leakage of reactive oxygen species from mitochondria, a process which preferentially targets neurons with high baseline oxidative stress. In one case, the extra oxidative stress comes from outside the cell and, in the other case, it comes from inside the cell, i.e. from mitochondria. There is also evidence that neurofibrillary tangles are a protective mechanism against extracellular oxidative stress and that α-synuclein is a marker for mitochondrial failure. The basic pathophysiological difference is that AD is caused by oxidative stress alone, whereas PD is caused by oxidative stress plus failure of energy production.     

Paraoxonase-1 polymorphisms in Alzheimer's disease, Parkinson's disease, and AD-PD spectrum diseases

Paraoxonase-1 (PON1) is a serum arylsulfatase that metabolizes organophosphate pesticides and protects low-density lipoprotein from oxidation. Case-control studies of PON1 genetic variants in Alzheimer's disease (AD) and Parkinson's disease (PD) have revealed some positive albeit inconsistent associations with 2 PON1 coding polymorphisms: Q192R (rs662) and L55M (rs854560). Because AD and PD exist along a spectrum of disorders with shared epidemiologic, clinical, and pathologic features, here we evaluated PON1 variants in a cohort of 746 AD, 566 PD, 132 AD-PD, and 719 cognitively normal age-matched controls. In the combined AD and Caucasian PD cohorts we had 80% power to detect a relative risk of at least 1.25 and 1.35, respectively, for each polymorphism. We found no association between 2 PON1 coding polymorphisms and AD in African Americans or Caucasians, and no association with PD or AD-PD in Caucasians. There was also no evidence of an interaction between PON1 and apolipoprotein E for any of these diseases. Our results suggest that either these functional PON1 polymorphisms are not associated with AD and PD spectrum disorders, or that the relative risk conferred is small.     

Mitochondrial DNA sequence analysis of four Alzheimer's and Parkinson's disease patients

The mitochondrial DNA (mtDNA) sequence was determined on 3 patients with Alzheimer's disease (AD) exhibiting AD plus Parkinson's disease (PD) neuropathologic changes and one patient with PD. Patient mtDNA sequences were compared to the standard Cambridge sequence to identify base changes. In the first AD + PD patient, 2 of the 15 nucleotide substitutions may contribute to the neuropathology, a nucleotide pair (np) 4336 transition in the tRNA^Gln gene found 7.4 times more frequently in patients than in controls, and a unique np 721 transition in the 12S rRNA gene which was not found in 70 other patients or 905 controls. In the second AD + PD patient, 27 nucleotide substitutions were detected, including an np 3397 transition in the ND1 gene which converts a conserved methionine to a valine. In the third AD + PD patient, 2 polymorphic base substitutions frequently found at increased frequency in Leber's hereditary optic neuropathy patients were observed, an np 4216 transition in ND1 and an np 13708 transition in ND5 gene. For the PD patient, 2 novel variants were observed among 25 base substitutions, an np 1709 substitution in the 16S rRNA gene and an np 15851 missense mutation in the cytb gene. Further studies will be required to demonstrate a causal role for these base substitutions in neurodegenerative disease. © 1996 Wiley-Liss, Inc.     

Lewy body pathology is associated with mitochondrial DNA damage in Parkinson's disease

Mitochondrial dysfunction has been strongly implicated in the pathogenesis of Parkinson's disease (PD) and Alzheimer's disease (AD), but its relation to protein aggregation is unclear. PD is characterized by synuclein aggregation (i.e., Lewy body [LB] formation). In AD, the abnormal accumulation of tau protein forms neurofibrillary tangles. In this study, we laser-dissected LB-positive and -negative neurons from the substantia nigra of postmortem PD brains, and tau-positive and -negative hippocampal neurons from AD brains. We quantified mitochondrial DNA deletions in relation to the cellular phenotype and in comparison with age-matched controls. Deletion levels were highest in LB-positive neurons of PD brains (40.5 ± 16.8%), followed by LB-negative neurons of PD cases (31.8 ± 14.4%) and control subjects (25.6 ± 17.5%; analysis of variance p < 0.005). In hippocampal neurons, deletion levels were 25%–30%, independent of disease status and neurofibrillary tangles. The presented findings imply increased mitochondrial DNA damage in LB-positive midbrain neurons, but do not support a direct causative link of respiratory chain dysfunction and protein aggregation.