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: 8783972
• 负责人: Yulia Dzhashiashvili
• 金额: $ 5.51万
• 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/8783972
• 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; 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(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运动神经元过早死亡。肌萎缩侧索硬化症是无法治愈的，这就需要更好地了解疾病的发病机制，以便开发有效的药物来治疗这种致命的疾病。大多数ALS病例(90%)没有明显的遗传成分(称为散发性)，而约10%是遗传性的(家族性)。铜/锌超氧化物歧化酶(SOD1)基因突变约占所有家族性形式的20%。散发性ALS与家族性ALS在临床上相似，因此有必要对家族性ALS进行研究以了解散发性ALS。尽管ALS的确切原因尚不清楚，但有证据表明，细胞内突变SOD1(MtSOD1)聚集体对运动神经元和邻近的非神经细胞具有毒性，这些细胞也与疾病密切相关。MtSOD1毒性的机制之一是触发内质网(ER)胁迫及其适应性信号转导途径，包括整合应激反应(ISR)。PERK通路是ISR的中心，ISR是一种细胞生存机制，由错误折叠或未折叠的蛋白质在内质网中积累而激活，有可能淹没细胞。本研究旨在探讨两个重要的ISR组分在ALS发病机制中的作用：PERK(ERK)和CHOP(参与应激介导的细胞死亡的转录因子)。在先前发现PERK通路对mtSOD1诱导的ALS具有保护作用的基础上，拟议的工作将检验一种假设，即运动神经元和/或少突胶质细胞中过度的ISR是导致ALS死亡的两种细胞类型的主要因素。PERK通路在少突胶质前体细胞(OPC)和雪旺细胞中的作用也将被研究。为此，在mtSOD1ALS小鼠模型中，将从运动神经元、少突胶质细胞、OPC和雪旺细胞中遗传删除PERK。此外，这项建议将阐述CHOP在ALS发病机制中的作用，并检验其作用是促凋亡的假设。如上所述，将在所有细胞(全局敲除)和不同细胞类型中产生的mtSOD1转基因小鼠中确定CHOP的作用。带有PERK或CHOP缺陷的mtSOD1转基因小鼠将通过临床和神经学评估、ISR成分的生化分析、免疫组化细胞存活的组织学分析以及电子显微镜下髓鞘完整性的超微结构分析来评估疾病进展。由于内质网应激存在于散发性和家族性肌萎缩侧索硬化症中，这项拟议的研究将为这两种疾病提供重要的见解。这些研究还应有助于确定ALS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，以防止这种毁灭性疾病的运动神经元退化。