The Rat Pre-Formed Alpha-Synuclein Fibril Model of Parkinson's Disease

帕金森病大鼠预制α-突触核蛋白原纤维模型

• 批准号: 9751424
• 负责人: Caryl E Sortwell
• 金额: $ 36.24万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9751424
• 关键词: Amygdaloid structure; Animal Model; Area; Behavior; Bilateral; Biological Models; Blood; Body Size; Clinical; Corpus striatum structure; Data; Denervation; Development; Diagnosis; Disease; Disease model; Dopamine; Drug Kinetics; Endopeptidase K; Exhibits; Female; Genetic; Human; Impairment; Injections; Intervention; Ipsilateral; Levodopa; Lewy Bodies; Light; Measurable; Memory impairment; Modeling; Monitor; Motor; Mus; Nerve Degeneration; Parkinson Disease; Pathologic; Pathology; Patients; Performance; Peripheral; Phase; Positron-Emission Tomography; Proteins; Rattus; Reporting; Resistance; Seeds; Substantia nigra structure; Synapses; Testing; Thioflavin S; Time; Tyrosine 3-Monooxygenase; Ubiquitin; Validation; alpha synuclein; brain size; clinical predictors; clinical translation; dopamine transporter; dopaminergic neuron; gender difference; in vivo; in vivo imaging; male; motor deficit; motor impairment; motor symptom; nerve supply; non-drug; novel; pars compacta; pharmacodynamic biomarker; pre-clinical; sample collection; synucleinopathy; treatment strategy; validation studies; vesicular monoamine transporter

Until recently no animal model of Parkinson’s disease (PD) has adequately incorporated both widespread alpha-synuclein (α-syn) pathology and protracted significant nigrostriatal degeneration. In 2012 Luk and colleagues described how intrastriatal injection of synthetic α-syn preformed fibrils (PFFs) into wildtype (WT) mice seeded endogenous accumulation of Lewy Body (LB)-like intracellular α-syn inclusions and ultimate nigrostriatal degeneration. In light of the fact that the rat model system offers distinct advantages over mice (fine motor behaviors, greater synaptic complexity, genetics and pharmacokinetics more similar to humans, larger brain and body size more amenable to neurosurgical interventions and sample collection), we recently characterized the results of unilateral injection of mouse α-syn PFFs into the striatum of rats. Similar to the mouse, we observed phosphorylated α-syn intraneuronal accumulations in several areas that innervate the striatum, most prominently the frontal and insular cortices, the amygdala, and the substantia nigra pars compacta (SNpc). α-Syn accumulations co-localized with ubiquitin, p62, and were thioflavin-S-positive and proteinase-k resistant. Although α-syn inclusions within the SNpc remained ipsilateral to striatal injection, we observed bilateral reductions in nigral dopamine neurons 6 months following α-syn PFF injection. Further, PFF injected rats exhibited reductions in striatal dopaminergic innervation as well as deficits in striatal dopamine and metabolites. This initial study demonstrates that α-syn PFFs are sufficient to seed the pathological conversion and propagation of endogenous α-syn to induce a progressive, neurodegenerative model of α- synucleinopathy in rats. In the present IGNITE application we seek to identify which α-syn species (human, mouse, rat) results in consistent loss of 60% nigral dopamine neurons over the course of 4 months after intrastriatal injection into rats (Aim 1). Once identified, we will conduct internal validation studies to systematically characterize the time course and magnitude of α-syn pathology, striatal dopamine and metabolite loss, levels of striatal dopaminergic innervation (tyrosine hydroxylase, vesicular monoamine transporter, and dopamine transporter) and deficits in motor behaviors (Aim 2). Lastly, we will conduct PD-relevant external validation studies including: 1) investigating whether PFF-induced motor deficits are reversible with levodopa and 2) conduct non-invasive longitudinal in vivo imaging of nigrostriatal DA synthesis, storage and turnover using positron emission tomography (PET) (Aim 3). We propose that optimization, internal validation and external validation studies in the progressive rat α-syn PFF PD model will allow for direct comparison to clinical metrics in PD patients and facilitate the development of novel disease modifying therapies.

直到最近，帕金森病 (PD) 的动物模型还没有充分整合这两种广泛存在的疾病。 α-突触核蛋白 (α-syn) 病理学和长期显着的黑质纹状体变性 2012 年 Luk 和 同事描述了如何将合成的 α-syn 预制原纤维 (PFF) 注射到野生型 (WT) 中 小鼠接种了类路易体 (LB) 细胞内 α-syn 内源性积累和最终 鉴于大鼠模型系统比小鼠具有明显的优势。 （精细运动行为、突触复杂性更高、遗传学和药代动力学与人类更相似， 更大的大脑和身体尺寸（更适合神经外科干预和样本收集），我们最近 与将小鼠 α-syn PFF 单侧注射到大鼠纹状体中的结果相似。 在小鼠中，我们观察到磷酸化的α-共神经元在几个区域中积累，这些区域支配着 纹状体，最显着的是额叶皮质和岛叶皮质、杏仁核和黑质部 Compacta (SNpc) 与泛素、p62 共定位，并且呈硫黄素-S 阳性且 尽管 SNpc 内的 α-syn 内含物仍与纹状体注射同侧，但我们仍对蛋白酶 K 具有抗性。 注射 α-syn PFF 后 6 个月观察到双侧黑质多巴胺神经元减少。 注射的大鼠显示纹状体多巴胺能神经支配减少以及纹状体多巴胺缺乏 这项初步研究表明 α-syn PFF 足以引发病理学。 内源性 α-syn 的转化和传播，诱导 α- 的渐进性神经退行性模型 在目前的 IGNITE 应用中，我们试图鉴定哪些 α-syn 物种（人类、 小鼠、大鼠）导致 4 个月内持续损失 60% 的黑质多巴胺神经元 一旦确定，我们将进行内部验证研究以进行大鼠纹状体内注射（目标 1）。 系统地表征 α-syn 病理学、纹状体多巴胺和 代谢物损失、纹状体多巴胺能神经支配水平（酪氨酸羟化酶、囊泡单胺 转运蛋白和多巴胺转运蛋白）和运动行为缺陷（目标 2）。 外部验证研究包括：1) 调查 PFF 引起的运动缺陷是否 左旋多巴可逆，2) 对黑质纹状体 DA 合成进行非侵入性体内纵向成像， 使用正电子发射断层扫描 (PET) 进行存储和周转（目标 3）。 在渐进性大鼠 α-syn PFF PD 模型中进行的内部验证和外部验证研究将允许 与帕金森病患者的临床指标进行直接比较，促进新的疾病缓解方法的开发 疗法。