突变的亨廷丁蛋白随着CAG重复扩张而减少:对治疗和生物测试的含义
Christian Landles1, Georgina F Osborne1, Jemima Phillips1
1Department of Neurodegenerative Disease, Huntington's Disease Centre, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK.
Brain communications
|December 23, 2024
概括
亨廷顿病涉及CAG在亨廷丁 (HTT) 基因中的重复扩张. 随着重复的增加,全长突变HTT减少,而致病性HTT1a增加,这表明新的治疗点.
科学领域:
- 神经科学是一个神经科学.
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
背景情况:
- 亨廷顿病 (HD) 是一种遗传性神经退行性疾病,由亨廷丁 (HTT) 基因的CAG重复扩张引起.
- 身体CAG重复扩张会影响疾病的发病和进展.
- HTT前mRNA的替代拼接产生了致病性HTT1a转录,产量增加与更长的CAG重复相关.
研究的目的:
- 调查CAG重复长度和突变的亨廷丁 (HTT) 蛋白水平之间的关系,包括全长的HTT和HTT1a异型.
- 评估生物测试以检测亨廷顿病模型中的不同HTT异型.
- 通过了解突变HTT和HTT1a生产的动态来告知治疗策略.
主要方法:
- 采用了一系列基因的敲进小鼠模型 (HdhQ20,HdhQ50,HdhQ80,HdhQ111,CAG140,zQ175) 具有不同的CAG重复长度.
- 在皮质溶解物中量化突变HTT水平,使用西布洛特.
- 评估了各种基于抗体的生物测试,用于同质时间解析光和Meso Scale Discovery平台检测HTT异型.
主要成果:
- 随着CAG重复长度的增加,突变HTT蛋白水平显著下降,在zQ175小鼠中达到野生类型水平的10% (∼190次CAG重复).
- 没有一个经过测试的生物测试准确地回顾了通过西布洛特观察到的全长突变HTT水平.
- 建议采用异型和特定物种的测定,而不是同时检测多个异型的测定.
结论:
- 在CAG重复长度和全长突变HTT水平之间的反相关性,以及增加的HTT1a产量,对HD疗法有着关键的影响.
- 针对全长HTT的HTT降低策略可能在晚期疾病中效果较差,因为已经耗尽了突变HTT水平.
- 这些发现支持了专注于减少HTT1a及其蛋白质产品的治疗方法.
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