Mutual regulation between RE1 Silencing Transcription Factor (REST) and Mitochondria in Neurodegenerative Disease

RE1沉默转录因子（REST）与线粒体在神经退行性疾病中的相互调节

• 批准号: 355558575
• 负责人: Dr. Katharina Meyer
• 金额: --
• 依托单位: Department of Genetics
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/355558575?language=en
• 关键词: Mutual; regulation; between; RE1; Silencing

Alzheimers disease (AD) is the most common form of dementia among the elderly with over 40 million individuals affected worldwide. AD is considered to be caused by neurotoxic protein aggregates of beta-amyloid (Ab) and tau that accumulate in the aging brain. However, this view is challenged by clinical observations and by the repetitive failure of AD clinical trials testing drugs that target these neurotoxic proteins. Recent evidence suggests that mitochondrial dysfunction precedes the formation of Ab plaques and neurofibrillary tau tangles, and that Ab and tau are not the primary cause of AD but rather promote neurodegeneration by exacerbating oxidative damage. The main risk factor for the development of AD is aging, and a common feature of the aging brain is reduced neuronal metabolic activity, increased oxidative stress and accumulating oxidative damage. It is hypothesized that such perturbed neuronal metabolism triggers a viscous cycle of further mitochondrial dysfunction and oxidative stress, which eventually results in neurodegeneration and AD. A recent discovery demonstrated that the RE1 silencing transcription factor (REST) is reactivated in the healthy ageing brain and controls a broad network of genes that protect from cell death, inflammation and AD pathology. However, the exact mechanism how neuronal REST levels are regulated during ageing remained elusive. This proposal is based on preliminary evidence indicating that REST controls cellular energy levels by restricting mitochondrial function. Interestingly, increased mitochondrial stress leads to the complete deletion of neuronal REST. These findings suggest that REST is part of a novel feedback mechanism that couples initial mitochondrial bioenergetic perturbations with a transcriptional collapse by deleting REST protein. This regulatory mechanism might distinguish healthy brain ageing from neurodegeneration and cognitive decline and should be further elucidated. Thus, the aim is to first establish REST knock out induced pluripotent stem cell (iPSC) lines using the CRISPR/Cas9-system. Subsequently they will be differentiated into neurons to assess mitochondrial function in REST knock out conditions. Secondly, I will assess the involvement of autophagy on REST expression and degradation. Lastly, endogenous REST will be tagged with a fluorescent protein in iPSC lines derived from AD patients and age matched controls, by CRISPR/Cas9. These lines will be used to firstly characterize REST expression in an in vitro model of AD. Finally, they will be used to clarify the implication of mitochondrial stress and autophagy on REST protein level.

阿尔茨海默病(AD)是老年人中最常见的痴呆症，全世界有超过4000万人受到影响。AD被认为是由在老化的大脑中积累的β-淀粉样蛋白(AB)和tau的神经毒性蛋白聚集体引起的。然而，这一观点受到了临床观察和AD临床试验反复失败的挑战，这些试验测试了针对这些神经毒性蛋白的药物。最近的证据表明，线粒体功能障碍先于抗体斑块和神经原纤维tau的形成，而Ab和tau不是AD的主要原因，而是通过加剧氧化损伤而促进神经退行性变。阿尔茨海默病发生的主要危险因素是衰老，而脑老化的一个共同特征是神经元代谢活性降低，氧化应激增加，氧化损伤累积。据推测，这种扰动的神经元代谢触发了进一步的线粒体功能障碍和氧化应激的粘性循环，最终导致神经变性和阿尔茨海默病。最近的一项发现表明，RE1沉默转录因子(REST)在健康老化的大脑中重新激活，并控制着广泛的基因网络，保护细胞免受细胞死亡、炎症和AD病理的影响。然而，衰老过程中神经元静息水平如何受到调节的确切机制仍不清楚。这一建议是基于初步证据表明，REST通过限制线粒体功能来控制细胞能量水平。有趣的是，线粒体压力的增加会导致神经元休眠的完全缺失。这些发现表明，REST是一种新的反馈机制的一部分，该机制通过删除REST蛋白将最初的线粒体生物能量扰动与转录崩溃结合在一起。这种调节机制可能会将健康的大脑老化与神经退化和认知衰退区分开来，应该进一步阐明。因此，我们的目标是首先利用CRISPR/Cas9-系统建立REST基因敲除诱导的多能干细胞(IPSC)系。随后，它们将被分化为神经元，以评估线粒体在静止敲除条件下的功能。其次，我将评估自噬对REST表达和降解的参与。最后，CRISPR/Cas9将在AD患者和年龄匹配的对照组的IPSC系中用荧光蛋白标记内源性REST。这些株系将首先用于表征AD体外模型中REST的表达。最后，他们将被用来阐明线粒体应激和自噬对静止蛋白质水平的影响。