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.     

蛋白质翻译后修饰在脓毒症中的研究进展

蛋白质翻译后修饰(Post-Translational Modifications, PTMs )在脓毒症(Sepsis)研究中扮演着至关重要的角色,通过调节蛋白质功能、信号传导、代谢途径和免疫反应,深刻影响疾病的进展。近年来,磷酸化、乙酰化、乳酸化等多种PTMs已被证明在脓毒症的病理机制中发挥独特作用,为理解这一复杂疾病的分子机制提供了新的视角。对PTMs的深入研究不仅为阐明脓毒症的发病机制提供了理论依据,还揭示了它们作为潜在治疗靶点的可能性。随着高通量组学技术的发展和多组学数据的整合分析,未来有望实现对脓毒症中PTMs变化的全面解析,从而推动个性化治疗的发展,并加速PTMs靶向药物的开发,最终可能提高脓毒症患者的治疗效果和生存率。     

蛋白质磷酸化对衣原体生理学影响的研究进展

衣原体是一类严格专性胞内寄生的原核细胞型微生物。蛋白质磷酸化是在细胞信号转导过程中起重要作用的一种蛋白质翻译后修饰方式,由蛋白质激酶和磷酸酶、双组分信号系统以及合作-开关机制3部分组成。蛋白质磷酸化可调节衣原体生理学过程,如代谢、发育、致病等。然而,由于衣原体特殊生长环境及研究方法的局限,介导和调节这些生理学过程的机制仍知之甚少。因此,本文就现阶段衣原体蛋白磷酸化及其在衣原体生理学方面的潜在作用进行综述。     

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.     

脂多糖增强小鼠腹腔巨噬细胞14.2kD蛋白质磷酸化

目的：探索ＬＰＳ对小鼠腹腔巨噬细胞小分子蛋白质磷酸化的影响。方法：利用同位素掺入、ＳＤＳ ＰＡＧＥ、放射自显影和蛋白质印迹（Ｗｅｓｔｅｒｎ ｂｌｏｔ） 、结合蛋白激酶抑制剂与激活剂的使用,研究ＬＰＳ对巨噬细胞处理后小分子蛋白质磷酸化及其相关蛋白激酶对此磷酸化的影响。结果：１４．２ ｋＤ蛋白质磷酸化被ＬＰＳ强烈地促进;ＭＡＰＫ的表达量未见明显变化;ＴＰＫ抑制剂三羟异黄酮（ｇｅｎｉｓｔｅｉｎ）明显抑制上述磷酸化;ＰＫＡ 激活剂佛斯可林（ｆｏｒｓｋｏｌｉｎ） 和Ｇｉ 蛋白抑制剂百日咳毒素对上述磷酸化无明显影响。结论：ＬＰＳ能促进１４．２ ｋＤ蛋白质的磷酸化,此磷酸化可能依赖酪氨酸蛋白激酶（ＴＰＫ） 。     

神经丝轻链蛋白与多聚谷氨酰胺病

多聚谷氨酰胺(polyQ)病作为一组遗传性神经退行性疾病,患者在临床前期已出现大脑结构和功能的病理改变。随着检测技术的进步,神经丝轻链蛋白(NfL)作为轴突损伤的敏感标志,已成为神经系统疾病最有前景的生物标志物之一。NfL可作为polyQ病临床前期和临床期神经退行性变的生物标志物,并与疾病的严重程度和病程的进展密切相关,尤其是在疾病分期方面具有较大的潜力。本文对NfL作为polyQ病生物标志物的价值及其潜在的研究方向进行了综述。     

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。     

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.     

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.     

人参皂甙Rd对大鼠大脑中动脉栓塞模型NMDA受体磷酸化的影响

目的:研究人参皂甙Rd(Ginsenoside Rd,GSRd)对大鼠大脑中动脉栓塞(MCAO)模型损伤后,NMDA受体NR2B亚基的表达及其磷酸化的影响。方法:建立大鼠MCAO模型,并在术前及术后给予人参皂甙Rd,之后进行神经行为学评分,通过TTC(2,3,5-氯化三苯基四氮唑)染色观察脑梗死体积变化,采用Western blot方法检测脑缺血区不同时间点NR2B及其磷酸化的Ser1303及Tyr1472的表达情况。结果:GSRd能够改善大鼠神经行为学评分,减小模型大鼠脑梗死体积;MCAO模型大鼠脑缺血损伤处的NR2B亚基、磷酸化Ser1303及Tyr1472的表达量均较假手术组升高;在MCAO术前及术后给予GSRd,能够有效降低损伤侧NR2B亚基、磷酸化Ser1303及Tyr1472的表达量,并且GSRd对于上述各项表达量的影响呈剂量依赖性。结论:人参皂甙Rd能够有效降低MCAO模型中NR2B及磷酸化Ser1303及Tyr1472的水平,提示人参皂甙Rd可能是通过调节脑缺血再灌注损伤后NMDAR中NR2B亚基及该亚基磷酸化Ser1303、Tyr1472位点的水平,从而发挥其对脑缺血再灌注损伤的保护作用。     

The Behaviour of human vitronectin in vivo: effects of complement activation, conformation and phosphorylation

We examined the behaviour in vivo of native, specifically phosphorylated, and multimeric vitronectin to determine the effects of these modifications on its turnover, distribution and molecular behaviour. In normal rabbits, the plasma half-life (T_1/2) of antigenically detected vitronectin was 8.00 ± 1.26 h (mean ± s.d.), with a fractional catabolic rate (FCR) of 18.77 ± 1.57%/h and extravascular/intravascular ratio (EV/IV) of 1.00 (0.48–1.60, median and range). For vitronectin selectively phosphorylated by protein kinase A, T_1/2 was 8.87 ± 0.48 h, with a significantly smaller FCR of 10.85 ± 0.71%/h (P<0.005) and an EV/IV of 0.28 (0.15–0.36) (P<0.05 compared with antigenically detected vitronectin). In vitro, phosphorylation had no effect on the affinity of vitronectin for heparin–Sepharose, while complement activation with cobra venom factor (CVF) led to a two-fold enrichment of ³²P-vitronectin within the SC5b-9 complex. In vivo CVF caused a rapid decrease in the circulating levels of ³²P-vitronectin and was accompanied by the prompt appearance of a high mol. wt species consistent with SC5b-9. Despite specific incorporation of ³²P-vitronectin into SC5b-9, both forms of the molecule had similar inhibitory effects on C9-mediated haemolysis of EAC1-7 cells. Urea-activated vitronectin was rapidly cleared from circulation with less than 15% remaining after 1 h while protein-bound label accumulated in the spleen, lung and liver. These results demonstrate that vitronectin is a rapidly metabolized protein whose in vivo behaviour is markedly altered when phosphorylated or activated to form multimers and SC5b-9.