生物条形码检测技术及其研究进展

生物条形码检测技术作为一种新的诊断工具,已逐渐应用于蛋白质、核酸和小分子物质的检测.生物条形码技术通过构建"纳米金颗粒-目标物-磁纳米颗粒"三明治结构,利用磁场作用,将结合在纳米金颗粒表面的大量相同序列的寡聚核苷酸洗脱下来,并进一步放大信号,实现对目标物的间接或直接检测.本文介绍了生物条形码检测技术的原理及其应用,综述...     

基于银染增强的纳米金探针定量检测microRNA

MicroRNA是一类存在于动植物体内的重要的、序列高度同源的基因表达转录后调节因子,近来对microRNA不同表达模式和调节作用的研究要求能够快速、灵敏、特异地检测痕量microRNA的方法．利用纳米金银染增强技术建立了一种简单快速的microRNA定量方法,以纳米金标记的寡核苷酸分子作为信号探针,以生物素标记寡核苷酸分子作为捕获探针,经链霉亲和素-生物素作用将靶序列捕获在固相载体酶标孔上,继而通过纳米金催化的银染增强放大效应产生高灵敏的识别信号,记录其吸光度值从而实现microRNA分子的定量．用该方法检测小鼠肝脏,脑组织中miR-122a和miR-128各自的含量及合成miR-122a,结果表明其在良好的线形范围(10 pmol/L～10 fmol/L)内最低检测限为10 fmol/L,能够特异地区别单核苷酸错配的靶microRNA．     

银染增强的纳米金标记探针对微量核酸的检测

本研究利用银染增强的纳米金技术建立了一种简单快速的核酸定量方法.该方法基于纳米金与烷巯基修饰的寡核苷酸分子共价键合作用,将纳米微粒报告基团标记在与靶核酸一端序列互补的寡核苷酸上,同时生物素化修饰另一端互补序列.靶核酸与两段寡核苷酸探针杂交后,借亲和素固定在酶标板孔内,通过纳米金催化的银染放大效应产生高灵敏的识别信号,适时记录其吸光度值从而实现核酸分子的定量.该检测方法检测单链核酸分子的灵敏度达0.1 fM,双链分子为10 fM.     

纳米生物条形码技术在分子诊断中的应用

纳米生物条形码技术是一种新型的分子诊断技术,在核酸和蛋白质检测领域已经分别达到和超过现今的检测灵敏度.该技术采用纳米颗粒修饰的核酸或抗体对靶分子进行识别,并利用磁场将其分离,操作简单,不依赖酶反应,具有广泛的应用前景.该技术在病毒DNA、癌症的指标蛋白质等方面的应用已有文献报道,并有望成为一种常规的分子诊断工具.     

模板法金纳米簇的制备及其在生物分子检测中的应用

金纳米簇(AuNCs)作为一种新型荧光纳米材料,是由几个到约一百个金原子组成的分子聚集体,因制备简单、光学性质优异以及毒性低等特性,近年来在生物传感领域得到了广泛应用。本文首先对以巯基化合物、树枝状化合物、多肽和蛋白质、寡核苷酸DNA等为模板制备AuNCs的模板法及其优点进行阐述,对AuNCs的紫外吸收、荧光及电化学性质进行介绍,之后重点总结基于荧光AuNCs的生物传感器在生物大分子及小分子检测中的应用,最后对AuNCs应用于生物传感领域所面临的挑战进行分析,并对其应用前景进行展望。     

Loss of the Mono-ADP-ribosyltransferase,Tiparp, Increases Sensitivity to Dioxin-induced Steatohepatitis and Lethality

The aryl hydrocarbon receptor (AHR) mediates the toxic effects of the environmental contaminant dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD). Dioxin causes a range of toxic responses, including hepatic damage, steatohepatitis, and a lethal wasting syndrome; however, the mechanisms are still unknown. Here, we show that the loss of TCDD-inducible poly(ADP-ribose) polymerase (Tiparp), an ADP-ribosyltransferase and AHR repressor, increases sensitivity to dioxin-induced toxicity, steatohepatitis, and lethality. Tiparp^−/− mice given a single injection of 100 μg/kg dioxin did not survive beyond day 5; all Tiparp^+/+ mice survived the 30-day treatment. Dioxin-treated Tiparp^−/− mice exhibited increased liver steatosis and hepatotoxicity. Tiparp ADP-ribosylated AHR but not its dimerization partner, the AHR nuclear translocator, and the repressive effects of TIPARP on AHR were reversed by the macrodomain containing mono-ADP-ribosylase MACROD1 but not MACROD2. These results reveal previously unidentified roles for Tiparp, MacroD1, and ADP-ribosylation in AHR-mediated steatohepatitis and lethality in response to dioxin.     

芳香烃受体核转位蛋白的结构及相关功能

芳香烃受体核转位蛋白（aryl hydrocarbon receptor nuclear translocator,ARNT）是碱性螺旋-环．螺旋转录因子超家族中新发现的PAS亚家族的成员之一。它是体内许多bHLH-PAS蛋白共同的专性配偶体,可以与芳香烃受体、低氧诱导因子、果蝇SIM蛋白等形成异二聚体并介导许多信号转导过程,从而使个体对环境污染物（如二恶英）、低氧状态等外界因素的改变产生相应的生物学效应,本文就ARNT的基本结构及其在体内的主要生理功能等方面作一综述。     

Curcumin and its derivatives inhibit 2,3,7,8,-tetrachloro-dibenzo-p-dioxin-induced expression of drug metabolizing enzymes through aryl hydrocarbon receptor-mediated pathway

Abstract

Certain dioxins, including 2,3,7,8,-tetrachloro-dibenzo-p-dioxin (TCDD), are exogenous ligands for an aryl hydrocarbon receptor (AhR) and induces various drug-metabolizing enzymes. In this study, we examined the effect of curcumin on expression of drug-metabolizing enzymes through the AhR and NF-E2 related factor 2 (Nrf2) pathways. Curcumin dose-dependently inhibited TCDD-induced expression of phase I enzyme cytochrome P450 1A1 (CYP1A1) and phase II enzymes NAD(P)H:quinone oxidoreductase-1 (NQO1) and heme oxygenase 1 (HO-1) but not tert-butyl hydroquinone-induced NQO1 and HO-1, suggesting that curcumin inhibited only AhR pathway, but not Nrf2 one directly. Furthermore, we used 14 curcumin derivatives and obtained the correlation between hydrophobicity of the compounds and suppressive effect against AhR transformation. Results from the quantitative structure active correlative analysis indicated that methoxy groups and β-diketone structure possessing keto-enol tautomerism in curcumin were necessary to inhibit AhR transformation, and the addition of methyl and methoxy group(s) to the curcumin increased the inhibition effect.