The PERKplexity of the integrated stress response in motor neurons and myelinatin

运动神经元和髓鞘质综合应激反应的 PERKplexity

• 批准号: 8875475
• 负责人: Yulia Dzhashiashvili
• 金额: $ 6万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8875475
• 关键词: Accounting; Address; Adult; Affect; Amyotrophic Lateral Sclerosis; Apoptotic; Astrocytes; Biochemical; Brain; Cell Death; Cell Survival; Cells; Cessation of life; Clinical; Clinical Trials; Collaborations; Cuprozinc Superoxide Dismutase; Development; Disease; Disease Progression; Electron Microscopy; Endoplasmic Reticulum; Event; Experimental Autoimmune Encephalomyelitis; Familial Amyotrophic Lateral Sclerosis; Foundations; Genetic; Immunohistochemistry; Inherited; Knock-out; Laboratories; Longevity; Mediating; Microglia; Motor Neurons; Multiple Sclerosis; Mus; Mutation; Myelin; Neurodegenerative Disorders; Neuroglia; Neurologic; Oligodendroglia; Onset of illness; Paralysed; Pathogenesis; Pathway interactions; Phosphoric Monoester Hydrolases; Phosphotransferases; Protein Dephosphorylation; Proteins; Replacement Therapy; Research; Respiratory Failure; Role; SOD1 gene; Schwann Cells; Signal Transduction; Signal Transduction Pathway; Spinal Cord; Stem cell transplant; Stem cells; Stress; Supporting Cell; Technology; Testing; Toxic effect; Transgenic Mice; Transgenic Organisms; Work; biological adaptation to stress; cell type; cofactor; endoplasmic reticulum stress; gain of function; genetic approach; illness length; insight; motor neuron degeneration; mouse model; mutant; novel therapeutic intervention; novel therapeutics; oligodendrocyte precursor; pre-clinical; precursor cell; premature; prevent; public health relevance; research study; response; transcription factor CHOP

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease, characterized by premature death of motor neurons in the brain and spinal cord. There is no cure for ALS, necessitating a better understanding of the disease pathogenesis in order to develop effective remedies for this fatal disorder. Most cases of ALS (90%) have no apparent genetic component (referred to as sporadic), whereas ~10% are inherited (familial). Mutations in the Cu/Zn superoxide dismutase (SOD1) gene comprise ~20% of all the familial forms. Sporadic and familial forms of ALS are clinically similar, thus justifyig research on familial ALS to understand sporadic cases. Although the precise cause of ALS remains unclear, evidence suggests that intracellular mutant SOD1 (mtSOD1) aggregates are toxic to motor neurons and neighboring non-neuronal cells, which are also critically involved in the disease. One of the proposed mechanisms for mtSOD1 toxicity involves triggering endoplasmic reticulum (ER) stress and its adaptive signaling transduction pathways, including integrated stress response (ISR). The PERK pathway is central to the ISR, which is a cellular survival mechanism activated by accumulation of misfolded or unfolded proteins in the ER that threaten to overwhelm a cell. The proposed research studies aim to investigate the roles of two prominent ISR components in ALS pathogenesis: PERK (ER kinase) and CHOP (transcription factor involved in stress-mediated cell death). Building upon previous findings that the PERK pathway is protective against mtSOD1-induced ALS, the proposed work will test the hypothesis that an overwhelmed ISR in motor neurons and/or oligodendrocytes, the two cell types that die in ALS, is a major factor that contributes to their demise. The role of the PERK pathway will also be investigated in oligodendrocyte precursor cells (OPCs) and in Schwann cells. To this end, PERK will be genetically deleted from motor neurons, oligodendrocytes, OPCs, and Schwann cells in the mtSOD1 ALS mouse model. Additionally, this proposal will address the role of CHOP in the pathogenesis of ALS and test the hypothesis that its effects are pro-apoptotic. The role of CHOP will be determined in mtSOD1 transgenic mice generated with CHOP deficiency in all cells (global knockout), as well as in distinct cell types, as described above. The mtSOD1 transgenic mice with PERK or CHOP deficiencies will be evaluated for disease progression using clinical and neurological assessment, biochemical analysis of ISR components, histological analysis of cell survival by immunohistochemistry, and ultrastructural analysis of myelin integrity by electron microscopy. Because ER stress is present in sporadic and familial ALS, the proposed research will provide important insights into both forms of the disease. These studies should also help identify the primary cell type involved in ALS, which is critical for development of novel therapeutic approaches, including stem cell transplantation, to prevent motor neuron degeneration in this devastating disease.

描述（由申请人提供）：肌萎缩侧索硬化症（ALS）是一种进行性神经退行性疾病，其特征是大脑和脊髓中运动神经元的过早死亡。 ALS 无法治愈，因此需要更好地了解该疾病的发病机制，以便针对这种致命疾病开发有效的治疗方法。大多数 ALS 病例 (90%) 没有明显的遗传因素（称为散发性），而约 10% 是遗传性的（家族性）。 Cu/Zn 超氧化物歧化酶 (SOD1) 基因突变约占所有家族型的 20%。散发性和家族性 ALS 在临床上相似，因此需要对家族性 ALS 进行研究以了解散发性病例。尽管 ALS 的确切病因尚不清楚，但有证据表明，细胞内突变型 SOD1 (mtSOD1) 聚集体对运动神经元和邻近的非神经元细胞具有毒性，而这些细胞也与该疾病密切相关。 mtSOD1 毒性的拟议机制之一涉及触发内质网 (ER) 应激及其适应性信号转导途径，包括综合应激反应 (ISR)。 PERK 通路是 ISR 的核心，ISR 是一种细胞生存机制，由内质网中错误折叠或未折叠蛋白质的积累激活，这些蛋白质有可能压倒细胞。拟议的研究旨在调查两个重要的 ISR 成分在 ALS 发病机制中的作用：PERK（ER 激酶）和 CHOP（参与应激介导的细胞死亡的转录因子）。基于之前的研究结果，即 PERK 通路对 mtSOD1 诱导的 ALS 具有保护作用，拟议的工作将检验以下假设：运动神经元和/或少突胶质细胞（这两种在 ALS 中死亡的细胞类型）中的 ISR 不堪重负，是导致其死亡的主要因素。 PERK 通路的作用也将在少突胶质细胞前体细胞 (OPC) 和雪旺细胞中进行研究。为此，将从 mtSOD1 ALS 小鼠模型的运动神经元、少突胶质细胞、OPC 和雪旺细胞中基因删除 PERK。此外，该提案将探讨 CHOP 在 ALS 发病机制中的作用，并检验其促凋亡作用的假设。 CHOP 的作用将在所有细胞（全局敲除）以及不同细胞类型中均缺乏 CHOP 的 mtSOD1 转基因小鼠中确定，如上所述。将使用临床和神经学评估、ISR 成分的生化分析、通过免疫组织化学对细胞存活进行组织学分析以及通过电子显微镜对髓磷脂完整性进行超微结构分析来评估具有 PE​​RK 或 CHOP 缺陷的 mtSOD1 转基因小鼠的疾病进展。由于 ER 应激存在于散发性和家族性 ALS 中，因此拟议的研究将为了解这两种形式的疾病提供重要见解。这些研究还应有助于确定 ALS 中涉及的主要细胞类型，这对于开发新的治疗方法至关重要，包括干细胞移植，以防止这种破坏性疾病中的运动神经元变性。