微RNA在多聚谷氨酰胺病中的作用研究进展

多聚谷氨酰胺(polyglutamine,PolyQ)病是一类因致病基因编码区的三核苷酸重复异常扩增而形成PolyQ肽链,最终导致选择性神经元变性乃至死亡的神经退行性疾病,其发病机制仍未完全阐明.微RNA(microRNA,miRNA)作为一种新的非蛋白质的基因表达调控因子,对真核生物的基因表达有非常重要的调控作用.近年来国内外学者日益关注miRNA在神经退行性疾病尤其是Po1yQ病中的功能及其作用机制.就目前miRNA在PolyQ病发病机制中的作用研究进展予以综述.     

组蛋白去乙酰化酶抑制剂治疗多聚谷氨酰胺病的研究进展

近年研究发现基因转录异常可导致亨廷顿病(Huntington's disease,HD)等多聚谷氨酰胺(polyglutamine,PolyQ)病中的神经元功能异常.组蛋白去乙酰化酶(histone deacetylases,HDACs)作为一种转录抑制因子,可与辅阻遏物复合体相互作用导致染色质重塑,最终抑制目的基因的转录.PolyQ蛋白与基因转录调控因子异常的相互作用可能是PolyQ病转录失调的原因之一.作者就PolyQ病转录失调的可能发生机制,尤其是组蛋白乙酰转移酶(histone acetyltransferases,HATs)和HDACs在其中所起的作用,以及组蛋白去乙酰化酶抑制剂(histone deacetylases inhibitors,HDACIs)的治疗潜能等方面予以综述.     

PML翻译后修饰在肿瘤细胞中的研究进展

<正>早幼粒细胞白血病(promyelocytic leukemia,PML)基因最初被发现于急性早幼粒细胞白血病(acute promyelocytic leukemia,APL)中,在大部分APL病例中发现染色体异位t(15;17),即17号染色体上的维甲酸受体α(retinoic acid receptorα,RARα)基因与位于15号染色体上的PML基因相互异位,产生新的融合蛋白PML-RARα,这种融合蛋白在APL中发挥重要的作用[1]。PML蛋白又称TRIM19,属于     

蛋白质磷酸化检测方法及原理

蛋白质是生命活动的物质基础,是机体细胞的重要组成部分.新生蛋白质多肽需要经过翻译后修饰才能转变为成熟蛋白质.翻译后修饰包括:甲基化、羟基化、羧基化、糖基化、脂酰化、异戊烯基化等共价修饰[1].蛋白质磷酸化是最重要的蛋白质翻译后修饰之一,在蛋白激酶催化作用下,磷酸基团由供体分子转移到蛋白质的含有羟基的氨基酸侧链上,具有可逆性[2].蛋白质磷酸化和去磷酸化几乎调节着生命活动的全部过程,文献显示在任何时间内真核细胞蛋白分子中约有1/3的数量在发生磷酸化[3],主要发生在丝氨酸、苏氨酸和酪氨酸上,较少见的磷酸化氨基酸还有精氨酸、组氨酸、赖氨酸以及天冬氨酸和谷氨酸等.蛋白质磷酸化氨基酸有4种类型:①氧-磷酸盐,通过羟氨基酸的磷酸化形成;②氮-磷酸盐,通过精氨酸、赖氨酸或组氨酸的磷酸化形成;③酰基磷酸盐,通过天冬氨酸或谷氨酸的磷酸化形成;④硫-磷酸盐,通过半胱氨酸磷酸化形成[4].     

小鼠肝细胞核磷酸化蛋白质组的提取和双向电泳分离

目的提取小鼠肝细胞核磷酸化蛋白并利用双向凝胶电泳分离小鼠肝细胞核磷酸化蛋白。方法提取小鼠肝细胞核蛋白并利用金属磷酸盐亲和层析树脂纯化出磷酸化蛋白后,进行一维等电聚焦分离和二维聚丙烯酰胺凝胶电泳分离,并挑选其中一个蛋白斑点进行质谱分析。结果成功提取了肝细胞核磷酸化蛋白,通过双向凝胶电泳分离技术成功建立了小鼠肝细胞核磷酸化蛋白质组图谱。质谱鉴定结果证实被挑选蛋白斑点是小鼠核磷酸化蛋白。结论磷酸化蛋白纯化技术结合二维凝胶电泳分离技术是研究肝细胞核磷酸化蛋白质组的有效方法,为进一步全面研究和鉴定小鼠肝细胞核磷酸化蛋白的功能打下了基础。     

pMHC 多聚体技术研究进展

抗原肽结合的主要组织相容性复合物(pMHC)通过形成多聚体可有效提高结合到位于T 细胞表面上的T 细胞受体(TCR)的亲合力。自从20 年前pMHC 四聚体首次被用于抗原特异性T 细胞检测以来,pMHC 四聚体已成为免疫分析中最重要的检测工具之一。近年来pMHC 多聚体在四聚体的基础上又取得了较大进展,更高价的pMHC 多聚体被研制出来以提高免疫检测的灵敏度;可逆化的pMHC 多聚体由于可以从T 细胞表面解离而避免了对T 细胞的功能损伤,也被发展用于抗原特异的T 细胞分离。pMHC 多聚体作为一类分子工具在抗原特异的T 细胞分析和免疫治疗中具有重要作用,对它的充分了解和有效运用能帮助我们更好地进行科学和临床应用。     

鼻咽癌组织与正常鼻咽上皮组织的差异磷酸化蛋白质组分析

目的：比较鼻咽癌(nasopharyngeal carcinoma, NPC)组织与正常鼻咽上皮组织磷酸化蛋白质组差异,筛选差异磷酸化蛋白质,为揭示NPC的发病机制提供依据。方法：采用双向凝胶电泳技术(2-DE)分离NPC组织与正常鼻咽上皮组织的总蛋白质,蛋白质转膜后与抗酪氨酸磷酸化抗体进行Western印迹分析,图像分析识别差异磷酸化蛋白质点,电喷雾-四极杆-串联质谱（ESI-Q-TOF MS/MS）鉴定差异的酪氨酸磷酸化蛋白质,采用NetPhos软件预测蛋白质的酪氨酸磷酸化位点,并采用生物信息学方法对差异磷酸化蛋白质的功能和亚细胞定位进行分析。采用Western印迹检测差异蛋白质（phosphatidylethanolamine- binding protein 1）在正常鼻咽黏膜组织和鼻咽癌组织的总蛋白质中的磷酸化水平。结果：建立了NPC组织与正常鼻咽上皮组织的酪氨酸磷酸化蛋白质表达谱,识别了25个差异酪氨酸磷酸化蛋白质,共鉴定了13个差异酪氨酸磷酸化蛋白质,其中7个蛋白质的酪氨酸磷酸化水平在NPC组织中增强,而6个蛋白质的酪氨酸磷酸化水平降低。NetPhos软件预测和生物信息学分析结果显示,13个差异蛋白质均存在酪氨酸磷酸化位点,其功能涉及物质代谢、细胞结构、细胞防御以及信号转导。与正常鼻咽黏膜组织相比较,差异蛋白phosphatidylethanolamine-binding protein 1在鼻咽癌组织中磷酸化表达水平下调。结论： 鉴定了13个可能与NPC发病相关的酪氨酸磷酸化蛋白质,为揭示NPC发病机制提供了科学论依据。     

蛋白质研究方法及在疾病研究中的应用

随着人类基因组计划的逐步完成,对基因功能的研究逐渐成了新的研究热点.蛋白质是基因功能的主要体现者和执行者,其表达模式和功能的研究成为后基因组时代研究的重要内容.蛋白质组学的兴起,以及人们对蛋白质结构和功能等性质的研究,可以阐述生命活动在生理或病理条件下的变化机制,进一步有利于研究人类疾病的发病机制.同时,蛋白质性质的研究技术也在不断改进和发展中,如双向电泳技术、质谱技术、酵母双杂交技术以及用于蛋白质结构和序列分析的生物信息学技术等都已经广泛应用于人类疾病研究,为疾病的早期诊断、预防与治疗等提供新的理论依据.目前,在确定诊断疾病相关的标记分子或标志物,深入病原微生物蛋白对宿主细胞的作用、人类蛋白质与疾病发病机制的研究以及引导新药开发、药靶发现和药物毒理学作用、药物耐药性研究等方面都取得了一定进展.该文主要对蛋白质性质研究的常用技术、在各种疾病中的应用以及当前存在的问题作简要综述.     

无机多聚磷酸盐在神经变性疾病中的作用、机制及潜在应用

无机多聚磷酸盐(inorganic polyphoshpate,polyP)是由磷酸根通过高能磷酸键连接而成的线状聚合物[1].在生物出现之前polyP就已经存在于地球.在早期地球的高压和干燥环境中能产生polyP,比如在类似地球早期环境的火山口存在polyP.polyP的广泛存在表明其在生物的起源和生存方面起到非常关...     

IVIM扩散加权成像在前列腺疾病中的研究进展

早发现、早诊断和早治疗对前列腺癌患者的预后有重要意义。体素内不相干运动（IVIM）成像可以区分组织水分子扩散和微循环灌注两种效应,能更准确反映组织的病理生理变化。IVIM在肿瘤领域具有很大的潜力,可以用于肿瘤的检出、诊断、分期、监测疗效及预后评估。本文重点就IVIM的原理及在前列腺疾病的研究进展予以综述。     

The evaluation of polyglutamine repeats in autosomal dominant Parkinson's disease

We evaluated the contributions of various polyglutamine (polyQ) disease genes to Parkinson's disease (PD). We compared the distributions of polyQ repeat lengths in 8 common genes (ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, TBP, ATN1, and HTT) in 299 unrelated patients with autosomal dominant PD (ADPD) and 329 normal controls. We also analyzed the possibility of genetic interactions between ATXN1 and ATXN2, ATXN2 and ATXN3, and ATXN2 and CACNA1A. Intermediate-length polyQ expansions (>24 Qs) of ATXN2 were found in 7 ADPD patients and no controls (7/299 = 2.34% and 0/329 = 0%, respectively; p = 0.0053 < 0.05/8 after Bonferroni correction). These patients showed typical L-DOPA-responsive PD phenotypes. Conversely, no significant differences in polyQ repeat lengths were found between the ADPD patients and the controls for the other 7 genes. Our results may support the hypothesis that ATXN2 polyQ expansion is a specific predisposing factor for multiple neurodegenerative diseases.     

Recent advances in understanding the pathogenesis of polyglutamine diseases: involvement of molecular chaperones and ubiquitin-proteasome pathway

Polyglutamine diseases consist of a group of familial neurodegenerative disorders caused by expression of proteins containing expanded polyglutamine stretch. Over the past several years, tremendous progress has been made in identifying the molecular mechanisms by which the expanded polyglutamine tract leads to neuronal dysfunction and neurodegeneration. A common feature of most polyglutamine disorders is the occurrence of ubiquitin-positive neuronal intranuclear inclusions. The appearance of ubiquitinated aggregates implies an underline incapability of the cellular chaperones and proteasome machinery that normally functions to prevent the accumulation of misfolded proteins. Here we review the recent studies that have revealed a critical role for molecular chaperones and ubiquitin-proteasome pathway in the pathogenesis of polyglutamine diseases.     

IL-23在眼部疾病中的研究进展

白细胞介素(interleukin,IL)-23作为IL-12家族中的重要成员具有强大的促炎作用,是一种重要的炎症因子。目前IL-23已经被发现与多种自身免疫性疾病和许多炎性疾病具有密切关系。越来越多的研究表明,IL-23在很多眼部疾病的发生发展过程中也起到关键作用。文章对IL-23在角膜病、眼表疾病、葡萄膜炎、糖尿病...     

马查多-约瑟夫病的分子遗传学研究进展

迄今为止,至少已定位了常染色体显性遗传小脑件共济失调28种不同的基因型,已克隆18个致病基因,其中对不同种族和地域的研究表明,马查多-约瑟夫病(Machado-Joseph disease,MJD),即脊髓小脑性共济失调3型(spinoocerebellar ataxia type 3,SCA3),是世界上最常见的SCAs亚型.它是由位于致病基因MJD13'端的CAG三核苷酸重复扩增突变引起的一种具有明显的临床和遗传异质性的神经系统退行性疾病.作者就SCA3/MJD的分子遗传学方面的研究进展进行综述.     

Huntington's disease (HD): the neuropathology of a multisystem neurodegenerative disorder of the human brain

Huntington's disease (HD) is an autosomal dominantly inherited, and currently untreatable, neuropsychiatric disorder. This progressive and ultimately fatal disease is named after the American physician George Huntington and according to the underlying molecular biological mechanisms is assigned to the human polyglutamine or CAG‐repeat diseases. In the present article we give an overview of the currently known neurodegenerative hallmarks of the brains of HD patients. Subsequent to recent pathoanatomical studies the prevailing reductionistic concept of HD as a human neurodegenerative disease, which is primarily and more or less exclusively confined to the striatum (ie, caudate nucleus and putamen) has been abandoned. Many recent studies have improved our neuropathological knowledge of HD; many of the early groundbreaking findings of neuropathological HD research have been rediscovered and confirmed. The results of this investigation have led to the stepwise revision of the simplified pathoanatomical and pathophysiological HD concept and culminated in the implementation of the current concept of HD as a multisystem degenerative disease of the human brain. The multisystem character of the neuropathology of HD is emphasized by a brain distribution pattern of neurodegeneration (i) which apart from the striatum includes the cerebral neo‐and allocortex, thalamus, pallidum, brainstem and cerebellum, and which (ii) therefore, shares more similarities with polyglutamine spinocerebellar ataxias than previously thought.     

Genetic aspects of Huntington's disease in Latin America. A systematic review

We aimed to present a systematic review on Huntington's disease (HD) in Latin America (LA). PubMed and LILACS were searched up to March 2015, reporting confirmed HD cases in LA. Case series, cross‐sectional, case–control, and prospective studies were included. From 534 communications, 47 were eligible. Population‐based studies were not found; minimal prevalence of 0.5–4/100,000 was estimated for Venezuela and Mexico. Geographical isolates were well characterized in Venezuela and in Peru. CAG repeats at HTT gene varied between 7–33 and 37–112 in normal and expanded alleles, respectively. Intermediate alleles were found in 4–10% of controls. Ages at onset and the expanded CAG repeats correlated with r from – 0.55 to –0.91. While haplotype patterns of Venezuelan and Brazilian chromosomes were similar to those observed in Europeans, haplotypes from Peruvian HD patients did not match the same pattern. The limited number of papers found suggests that HD is poorly diagnosed in LA. Minimal prevalence seemed to be halfway between those of Caucasians and Asians. Range of CAG repeats was similar to those of Europeans. Haplotype studies indicate that majority of HD patients might be of Caucasian descent; an Asian origin for some Peruvian patients was proposed.     

Cleavage and conformational changes of tau protein follow phosphorylation during Alzheimer's disease

Phosphorylation, cleavage and conformational changes in tau protein all play pivotal roles during Alzheimer's disease (AD). In an effort to determine the chronological sequence of these changes, in this study, using confocal microscopy, we compared phosphorylation at several sites (Ser(199/202/396/404/422)-Thr(205) and the second repeat domain), cleavage of tau (D(421)) and the canonical conformational Alz-50 epitope. While all of these posttranslational modifications are found in neurofibrillary tangles (NFTs) at all stages of the disease, we found significantly higher numbers of phospho-tau positive NFTs when compared with cleaved tau (P = 0.006 in Braak III; P = 0.002 in Braak IV; P = 0.012 in Braak V) or compared with the Alz-50 epitope (P < 0.05). Consistent with these findings, in a double transgenic mice model (Tet/GSK-3beta/VLW) overexpressing the enzyme glycogen synthase kinase-3beta (GSK-3beta) and tau with a triple FTDP-17 mutation (VLW) with AD-like neurodegeneration, phosphorylation at sites Ser(199/202)-Thr(205) was greater than truncated tau. Taken together, these data strongly support the notion that the conformational changes and truncation of tau occur after the phosphorylation of tau. We propose two probable pathways for the pathological processing of tau protein during AD, either phosphorylation and cleavage of tau followed by the Alz-50 conformational change or phosphorylation followed by the conformational change and cleavage as the last step.