Activation of Neuronal Degradative Pathways to Ameliorate Prion Disease

激活神经元降解途径以改善朊病毒病

• 批准号: 10855708
• 负责人: SANDRA E Encalada
• 金额: $ 87.2万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10855708
• 关键词: Agreement; Alzheimer' s Disease; Alzheimer' s disease patient; Alzheimer' s disease related dementia; Automobile Driving; Autophagocytosis; Axon; Axonal Transport; Behavioral; Biological; Brain; CRISPR-mediated transcriptional activation; Candidate Disease Gene; Categories; Cell model; Cells; Clinical; Creutzfeldt-Jakob Syndrome; Cytoskeleton; Data; Degradation Pathway; Deposition; Disease; Drug Targeting; Elements; Endosomes; Excision; Fatal Familial Insomnia; Functional disorder; Gene Targeting; Genes; Genetic; Gerstmann-Straussler-Scheinker Disease; Gliosis; Goals; Grant; Human; Impaired cognition; Impairment; Investigation; Kinesin; Lesion; Lipids; Lysosomes; Modeling; Molecular Motors; Movement; Mus; Mutation; Neurodegenerative Disorders; Neurologic; Neuronal Dysfunction; Neurons; Organelles; Other Genetics; Pathogenicity; Pathologic; Pathology; Pathway interactions; Penetrance; Pharmaceutical Preparations; Poisoning; PrP; PrP gene; Preclinical Testing; Prion Diseases; Prions; Property; Rare Diseases; Sleep disturbances; Sorting; Structure; Swelling; Testing; Therapeutic; Toxic effect; Up-Regulation; Vesicle; Work; aggregation pathway; clinical candidate; disease phenotype; efficacy evaluation; efficacy testing; functional restoration; genome wide screen; improved; improved outcome; insight; misfolded protein; mouse model; mutant; nanomolar; neuron loss; neurotoxic; pharmacologic; prevent; protein aggregation; screening; small molecule; therapy development; trafficking; vesicle transport; virtual

ABSTRACT Prionopathies are rare human neurodegenerative diseases characterized by spongiform change, gliosis, and by the deposition of misfolded prion protein (PrP) aggregates inside and outside of neurons across the brain. While cellular mechanisms remain largely undefined, evidence points toward a particular vulnerability of axons to the formation of misfolded protein aggregates, and their accumulation inside lysosome-like compartments suggests defective lysosomal degradative pathways in axons. Indeed, axonal dystrophies with enlarged endosomes occur early in disease in virtually all neurodegenerative diseases including Alzheimer’s Disease and Alzheimer’s Disease related dementias, where lysosomal dysfunction is well-recognized. Compelling evidence shows that PrP aggregates impair neuronal function by driving the accumulation of organelles/vesicles and cytoskeletal elements, thus poisoning axonal transport. This application builds on our previous findings that identified an endolysosomal pathway unique to axons, that promotes the initial stages of formation of misfolded mutant PrP aggregates inside enlarged endolysosome structures that do not acidify and thus fail to degrade misfolded and aggregated mutant PrP from axons, indicating impaired lysosomal degradation. We showed that in this axonal rapid endosomal sorting and transport-dependent aggregation (ARESTA) pathway, the molecular motor kinesin- 1C (KIF5C) transports vesicles carrying pathogenic and misfolded mutant PrP into axons resulting in neurotoxic axonal dystrophies filled with PrP aggregates inside endosomes that we term ‘endoggresomes’. Reducing the function of ARESTA genes, including kinesin-1, efficiently inhibits mutant PrP endoggresome formation and restores neuronal function. Furthermore, we have identified and tested a lysosomal flux activator (LFA) small molecule that efficiently inhibits and/or clears mutant PrP aggregate-containing endoggresomes from axons, restoring neuronal function. These findings form the premise of the central hypothesis of this grant that states that targeting neurotoxic axonal aggregates by genetic inhibition of ARESTA or by pharmacologic activation of lysosomal flux, prevents the formation of misfolded PrP aggregates and/or clears them, and ameliorates disease phenotypes in cellular and mouse models of prion disease. Our main LFA candidate molecule degrades PrP aggregates in the lower nanomolar range, does not show any overt signs of toxicity in mice, and has brain penetrance. The proposed aims will test the efficacy of LFAs in cellular (neuronal) and mouse models of familial and infectious prion disease. We will also identify the mechanisms of action (MoA) of LFAs. Our findings reveal a therapeutic strategy to treat prionopathies by genetic and pharmacological activation of macroautophagy. As lysosomal clearance is a common pathway impaired in Alzheimer’s Disease and Alzheimer’s Disease related dementias, our findings are expected to also be relevant to the treatment of these disorders.

摘要 朊病毒病是一种罕见的人类神经退行性疾病，其特征在于海绵状变化，神经胶质增生， 错误折叠的朊病毒蛋白（PrP）聚集在整个大脑的神经元内外。而 细胞机制仍然在很大程度上不明确，证据指向轴突对神经元的特殊脆弱性。 错误折叠的蛋白质聚集体的形成，以及它们在溶酶体样隔室中的积累表明 轴突中溶酶体降解途径缺陷。事实上，轴突营养不良与扩大内涵体发生 在几乎所有神经退行性疾病的疾病早期，包括阿尔茨海默病和阿尔茨海默氏病， 疾病相关性痴呆，其中溶酶体功能障碍是公认的。令人信服的证据表明， PrP聚集体通过驱动细胞器/囊泡和细胞骨架的积累损害神经元功能 元素，从而毒害轴突运输。这个应用程序建立在我们以前的发现，确定了一个 轴突特有的内溶酶体途径，促进错误折叠突变PrP形成的初始阶段 扩大的内溶酶体结构内的聚集体不酸化，因此不能降解错误折叠， 来自轴突的聚集的突变PrP，表明受损的溶酶体降解。我们发现在这个轴突中 快速内体分选和转运依赖性聚集（ARESTA）途径，分子运动驱动蛋白- 1C（KIF 5C）将携带致病性和错误折叠突变型PrP的囊泡转运到轴突中，导致神经毒性 轴突营养不良充满了PrP聚集体内的内涵体，我们称之为'endoggresome'。减少 包括驱动蛋白-1在内的ARESTA基因的功能有效抑制突变型PrP内分泌体的形成， 恢复神经元功能此外，我们已经确定并测试了一种溶酶体通量激活剂（LFA）， 有效抑制和/或清除轴突中含有突变PrP聚集体的内分泌体的分子， 恢复神经元功能这些发现构成了这项资助的中心假设的前提， 通过基因抑制ARESTA或药理学激活 溶酶体通量，防止错误折叠的PrP聚集体的形成和/或清除它们，并改善疾病 朊病毒疾病的细胞和小鼠模型中的表型。我们的主要LFA候选分子降解PrP 在较低纳摩尔范围内聚集，在小鼠中未显示任何明显的毒性迹象， 外显率所提出的目的将测试LFA在家族性免疫缺陷综合征的细胞（神经元）和小鼠模型中的功效。 和传染性朊病毒病。我们还将确定LFA的作用机制（MoA）。我们的发现揭示了 一种通过遗传和药理学激活巨自噬来治疗朊病毒病的治疗策略。作为 溶酶体清除是阿尔茨海默病和阿尔茨海默病相关疾病中受损的常见途径。 痴呆症，我们的研究结果预计也与这些疾病的治疗有关。