Quantification of mutant huntingtin protein in cerebrospinal fluid from Huntington's disease patients
Quantification of mutant huntingtin protein in cerebrospinal fluid from Huntington's disease patients
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DOI：
10.1172/jci80743
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发表时间：
2015-05-01
影响因子：
15.9
通讯作者：
Weiss, Andreas
中科院分区：
文献类型：
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作者：
Wild, Edward J.;Boggio, Roberto;Weiss, Andreas
背景技术背景：脑脊液（CSF）中疾病相关蛋白的定量对于研究和治疗几种神经退行性疾病至关重要;然而，突变型亨廷顿蛋白（mHTT），亨廷顿病（HD）的病因，在CSF中处于非常低的水平，并且据我们所知，以前从未测量过。我们开发了一种超灵敏的单分子计数（SMC）mHTT免疫测定法，用于定量2个独立队列中携带HD突变的个体和对照个体的CSF样本中的mHTT水平。该SMC mHTT免疫测定显示出对mHTT的高特异性、具有飞摩尔检测阈值的高灵敏度和宽动态范围。CSF样本的分析显示，在所有对照的CSF中均检测不到mHTT，但在几乎所有突变携带者中均可定量。明显HD患者CSF中的mHTT浓度约为表现前突变携带者的3倍。此外，mHTT水平随着疾病进展而增加，并与5年发病概率相关。mHTT浓度独立预测认知和运动功能障碍。此外，mHTT的水平与脑脊液中tau蛋白和神经丝轻链的浓度相关，这表明检测到的mHTT.CONCLUSIONS神经元起源：我们已经证明，mHTT可以定量从HD患者的CSF中使用所述SMC mHTT免疫测定。此外，检测到的mHTT水平与接近疾病发作以及认知和运动功能下降有关。定量CSF mHTT的能力将促进HD的研究，mHTT定量可能作为开发和测试HD实验性mHTT降低疗法的生物标志物。
BACKGROUND: Quantification of disease-associated proteins in the cerebrospinal fluid (CSF) has been critical for the study and treatment of several neurodegenerative disorders; however, mutant huntingtin protein (mHTT), the cause of Huntington's disease (HD), is at very low levels in CSF and, to our knowledge, has never been measured previously.METHODS: We developed an ultrasensitive single-molecule counting (SMC) mHTT immunoassay that was used to quantify mHTT levels in CSF samples from individuals bearing the HD mutation and from control individuals in 2 independent cohorts.RESULTS: This SMC mHTT immunoassay demonstrated high specificity for mHTT, high sensitivity with a femtomolar detection threshold, and a broad dynamic range. Analysis of the CSF samples showed that mHTT was undetectable in CSF from all controls but quantifiable in nearly all mutation carriers. The mHTT concentration in CSF was approximately 3-fold higher in patients with manifest HD than in premanifest mutation carriers. Moreover, mHTT levels increased as the disease progressed and were associated with 5-year onset probability. The mHTT concentration independently predicted cognitive and motor dysfunction. Furthermore, the level of mHTT was associated with the concentrations of tau and neurofilament light chain in the CSF, suggesting a neuronal origin for the detected mHTT.CONCLUSIONS: We have demonstrated that mHTT can be quantified in CSF from HD patients using the described SMC mHTT immunoassay. Moreover, the level of mHTT detected is associated with proximity to disease onset and diminished cognitive and motor function. The ability to quantify CSF mHTT will facilitate the study of HD, and mHTT quantification could potentially serve as a biomarker for the development and testing of experimental mHTT-lowering therapies for HD.