GD3S knockdown to improve cognitive and motor deficits in models of parkinsonism

描述（由申请人提供）：帕金森病的特征是运动和认知障碍以及大脑中称为黑质（SNc）的部分中的细胞死亡。帕金森病患者的大脑中也会聚集1-突触核蛋白，这可能对脑细胞有毒。我们的长期目标是更好地了解帕金森病的早期生物学事件，以及它们与疾病的认知和运动症状的关系。本申请的目的是初步了解神经节苷脂在与帕金森病相关的认知障碍和神经病理学中的作用。神经节苷脂是在身体的每个组织中表达的脂质。它们在大脑中特别丰富，但它们在帕金森病中的大脑分布异常。拟议研究的一般假设是，部分减少更复杂的神经节苷脂可以防止细胞死亡，减少1-突触核蛋白聚集，并减轻三种小鼠模型帕金森病各种特征的认知和运动缺陷。由于帕金森病患者表现出的认知障碍类型尚未在小鼠中进行研究，因此小鼠将首先接受旨在测量“执行”功能的复杂行为任务的训练。执行功能是参与高阶认知过程所必需的基本认知过程，如注意力、超维转换、冲动控制和短期工作记忆。这些模型包括注射神经毒素MPTP的小鼠、表达突变1-突触核蛋白的转基因小鼠和缺乏PARK 2的敲除小鼠。一旦建立基线行为和运动表现，小鼠将接受靶向GD 3合酶（GD 3S）的小干扰RNA（siRNA）构建体或乱序对照的注射。GD 3S负责合成四种主要脑神经节苷脂中的两种，在阿尔茨海默病小鼠模型中消除这种酶可以恢复良好的认知功能，阻断细胞死亡和氧化应激，并几乎消除淀粉样蛋白斑块的形成。GD 3S-siRNA构建体将通过重组腺相关病毒载体（rAAV）增殖，并注射到脑的背侧第三脑室中以促进分散。手术后，将进行额外的运动和行为测试，然后对大脑进行神经化学和免疫组织化学处理。在小鼠模型中成功减少1-突触核蛋白聚集、细胞死亡和认知障碍可能为帕金森病的新治疗策略提供见解，这些治疗可以恢复帕金森病患者的功能或减缓疾病进程。

DESCRIPTION (provided by applicant): Parkinson's disease is characterized by motor and cognitive impairments and cell death in a part of the brain called the substantia nigra pars compacta (SNc). Parkinson's patients also get aggregations of 1-synuclein in the brain, which may be toxic to brain cells. Our long-term goal is to understand better the early biological events in Parkinson's disease and how they relate to the cognitive and motor symptoms of the disease. The objective of this particular application is to get a preliminary understanding of the role that gangliosides play in the cognitive impairments and neuropathology associated with Parkinson's disease. Gangliosides are lipids expressed in every tissue in the body. They are particularly abundant in the brain, but their brain distribution is abnormal in Parkinson's disease. The general hypothesis of the proposed research is that a partial reduction of the more complex gangliosides may prevent cell death, reduce 1-synuclein aggregation, and alleviate cognitive and motor deficits in three mouse lines that model various characteristics of Parkinson's disease. Because the types of cognitive impairments exhibited by Parkinson's patients have not been investigated in mice, mice will first be trained on complex behavioral tasks designed to measure "executive" functions. Executive functions are basic cognitive processes that are necessary for engaging in higher-order cognitive processes, such as attention, extradimensional shift, impulse control, and short-term working memory. The models include mice injected with the neurotoxin MPTP, a transgenic expressing mutant 1- synuclein, and a knockout mouse lacking PARK2. Once baseline behavioral and motor performance is established, mice will receive an injection of a small-interfering RNA (siRNA) construct targeting GD3 synthase (GD3S), or a scrambled control. GD3S is responsible for synthesis of two of the four major brain gangliosides, and elimination of this enzyme in a mouse model of Alzheimer's disease restores good cognitive function, blocks cell death and oxidative stress, and nearly eliminates amyloid plaque formation. The GD3S-siRNA construct will be propagated by a recombinant adeno-associated viral vector (rAAV), and injected into the dorsal third ventricle of the brain to promote dispersion. Following the surgery, additional motor and behavioral tests will be conducted, followed by processing of the brains for neurochemistry and immunohistochemistry. Successfully reducing 1-synuclein aggregation, cell death, and cognitive impairments in the mouse models may provide insight into new treatment strategies for Parkinson's disease-treatments that could restore function or slow the disease process Parkinson's patients.