Studies of Hirano Bodies in Living Cells

描述（由申请人提供）：平野小体是与衰老细胞病理和各种神经退行性疾病（包括阿尔茨海默病、帕金森病和肌萎缩性侧索硬化症）相关的细胞质包涵体。由于先前对平野尸体的研究是在保存完好的临床脑样本上进行的，因此没有关于平野尸体对细胞生理、衰老或神经退行性疾病影响的直接信息。平野体在培养细胞中形成的模型最近被描述。在病理样本中，模型平野体与平野体在先前的平野体超微结构和免疫组织化学研究中描述的所有标准中都无法区分。平野小体是一种广泛存在的与许多重大疾病相关的细胞质蛋白包涵体，因此确定其对神经元细胞生理的影响是很重要的。本项目旨在验证以下3种假说：1)平野体促进/反映细胞病理和毒性；2)平野体是一种适应性结构，可促进神经细胞在已知可导致神经退行性疾病的压力下存活；或3)平野体对生理应激下神经元细胞的存活无影响。平野小体对涉及神经退行性疾病病理的5种应激的神经毒性的影响将被确定。这5种应激分别是：1)氧化应激损害蛋白质、脂质和核酸；2)谷氨酸兴奋性毒性，引发细胞内钙的长期升高；3)缺血（ATP耗竭），最常与中风或缺氧相关；4) Ab肽，阿尔茨海默病病理启动的主要候选物；5)淀粉样蛋白前体蛋白（AICD）的胞质内结构域，可以启动程序性细胞死亡。这一结果将为平野体通过促进疾病中神经元的死亡或存活来影响受到生理应激挑战的神经元细胞存活的假设提供直接检验。阐明平野小体在疾病中的潜在作用是可能发展动物模型、干预或治疗的先决条件。

DESCRIPTION (provided by applicant): Hirano bodies are cytoplasmic inclusions described in association with the cellular pathology of aging, and a variety of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis. Since previous studies of Hirano bodies have been performed on preserved clinical brain samples, there is no direct information on the effects of Hirano bodies on cell physiology, aging, or neurodegenerative disease. A model for formation of Hirano bodies in cultured cells has recently been described. The model Hirano bodies are indistinguishable from Hirano bodies in pathology samples in all criteria described by prior ultrastructural and immunohistochemical studies of Hirano bodies. Since Hirano bodies are a widespread type of cytoplasmic protein inclusion associated with numerous significant diseases, it is important to determine their effects on the physiology of neuronal cells. The aim of this project is to test the following 3 alternative hypotheses: 1) Hirano bodies promote/ reflect cellular pathology and toxicity; 2) Hirano bodies are adaptive structures that promote survival of neuronal cells under stresses that are known to contribute to neurodegenerative diseases; or 3) Hirano bodies have no effect on survival of neuronal cells under physiological stress. The effect of Hirano bodies on the neurotoxicity of 5 stresses implicated in the pathology of neurodegenerative disease will be determined. These 5 stresses are: 1) oxidative stress that damages protein, lipid, and nucleic acid; 2) glutamate excitotoxicity that initiates prolonged elevation of intracellular calcium; 3) ischemia (ATP depletion) most commonly associated with stroke or hypoxia; 4) Ab peptide, the leading candidate for initiation of the pathology of Alzheimer's disease; and 5) the intracellular cytoplasmic domain of the amyloid precursor protein (AICD) that can initiate programmed cell death. The results will provide a direct test of the hypothesis that Hirano bodies affect the survival of neuronal cells challenged with physiological stress by promoting either the death or the survival of neurons in disease. Elucidation of the potential roles of Hirano bodies in disease is prerequisite to possible development of animal models, interventions, or therapies.