Development of a Translational Research Platform to Understand and treat Defective Protein Trafficking in Childhood-Onset Hereditary Spastic Paraplegia

开发转化研究平台以了解和治疗儿童遗传性痉挛性截瘫中的缺陷蛋白贩运

• 批准号: 10406373
• 负责人: Darius Ebrahimi-Fakhari
• 金额: $ 19.6万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10406373
• 关键词: 10 year old; Adaptor Protein Complex Subunits; Adaptor Signaling Protein; Address; Adult; Advisory Committees; Affect; Autophagocytosis; Autophagosome; Axon; Behavior assessment; Biological Assay; Biology; Boston; Brain; CRISPR/Cas technology; Cells; Cellular biology; Child; Childhood; Complex; Corticospinal Tracts; Development; Disease; Disease Progression; Disease model; Fibroblasts; Fluorescence; Foundations; Future; Genes; Genetic Engineering; Genetic Models; Goals; Hereditary Spastic Paraplegia; Human; Image; Immunohistochemistry; Impairment; In Vitro; Individual; Induced pluripotent stem cell derived neurons; Inherited; Integral Membrane Protein; Label; Larva; Lead; LysoTracker; Lysosomes; Measures; Mediating; Mentors; Microscopy; Modeling; Morphology; Motor; Motor Neurons; Nerve Degeneration; Neurites; Neurodegenerative Disorders; Neurology; Neurons; Pathway interactions; Patients; Pediatric Hospitals; Pediatric Neurology; Phenotype; Physicians; Positioning Attribute; Program Development; Proteins; Research; Role; Scientist; Simvastatin; Spinal; Stains; Starvation; Survival Analysis; TFAP2A gene; Testing; Training; Transcription Factor AP-1; Translational Research; Variant; Vesicle; Western Blotting; Wheelchairs; Work; Zebrafish; age related; axonal degeneration; base; behavior test; career; career development; disability; experimental study; human disease; human model; in vivo; induced pluripotent stem cell; knock-down; loss of function; medical schools; molecular phenotype; motor deficit; nervous system disorder; neurodevelopment; neuronal cell body; novel; protein complex; protein phosphatase inhibitor-2; protein transport; restoration; screening; skills; small molecule; spasticity; trafficking; trans-Golgi Network; translational neuroscience; translational pipeline

The hereditary spastic paraplegias (HSP) are a group of over 80 neurodegenerative conditions and the most common cause of inherited spasticity and associated disability. This K08 proposal focuses on prototypical forms of HSP in children caused by biallelic loss-of-function variants in four genes that encode subunits of the adaptor protein complex 4 (AP-4): AP4B1, AP4M1, AP4E1, and AP4S1. Progressive degeneration of the cortico-spinal tracts renders most children with AP-4-associated HSP wheelchair-dependent by the age of 10 years. Currently, there are no therapies that halt disease progression, and few patients are known to have survived into adulthood, highlighting the urgency for research into the fundamental biology of HSP. The AP-4 complex is crucial for the intracellular trafficking of transmembrane proteins, including the autophagy-related protein ATG9A. How altered trafficking of ATG9A leads to impaired neurodevelopment and axonal degeneration and how ATG9A distribution can be restored is currently unknown. In this proposal, I will address this unmet question by developing neuronal models of AP-4 deficiency and testing novel modulators of AP-4-dependent protein trafficking. In preliminary experiments, we have systematically screened small molecule modulators of ATG9A trafficking using a cell-based phenotypic assay that measures ATG9A distribution as a surrogate of AP-4 function. We identified several modulators of ATG9A distribution. I will test the hypothesis that these restore trafficking and function of ATG9A in vitro in neurons derived from AP-4-HSP patients and in vivo in an ap4b1-/- zebrafish model. This proposal presents a five-year research career development program focused on the study of AP-4 in HSP to expand the breadth and depth of understanding the role of protein trafficking and autophagy in this group of diseases. The goal is the establishment of a cross-organismal screening platform to identify and develop novel modulators of protein trafficking for the treatment of HSP. The candidate is currently a resident in Child Neurology at the Department of Neurology at Boston Children's Hospital and Harvard Medical School. The outlined proposal builds on the candidate's previous research on protein trafficking, autophagy and neurodegeneration and integrates new domains of expertise in cell biology, advanced microscopy, and iPSC-derived neurons and genetically-engineered zebrafish to model human diseases. These skills are reflected in his mentoring team consisting of primary mentor, Dr. Mustafa Sahin, and a scientific advisory committee consisting of Dr. Craig Blackstone, Dr. Thomas Schwarz, Dr. Annapurna Poduri and Dr. Leonard Zon. The proposed experiments and didactic work will position the candidate with a unique set of cross-disciplinary skills that will enable his transition to independence as a physician-scientist in the field of translational neuroscience in childhood-onset neurological diseases.

遗传性痉挛性截瘫 (HSP) 是一组超过 80 种神经退行性疾病，其中最常见的是 遗传性痉挛和相关残疾的常见原因。这个 K08 提案重点关注原型 儿童中的 HSP 形式是由编码亚基的四个基因的双等位基因功能丧失变异引起的 接头蛋白复合物 4 (AP-4)：AP4B1、AP4M1、AP4E1 和 AP4S1。进行性退化 皮质脊髓束导致大多数 AP-4 相关 HSP 儿童在 10 岁时依赖轮椅 年。目前，没有任何疗法可以阻止疾病进展，并且已知很少有患者患有此病。 存活到成年，凸显了研究 HSP 基础生物学的紧迫性。 AP-4 复合物对于跨膜蛋白的细胞内运输至关重要，包括 自噬相关蛋白 ATG9A。 ATG9A 运输的改变如何导致神经发育受损 轴突变性以及如何恢复 ATG9A 分布目前尚不清楚。在这个提案中，我将 通过开发 AP-4 缺陷的神经元模型并测试新型调节剂来解决这个未解决的问题 AP-4 依赖性蛋白质运输。在初步实验中，我们系统地筛选了小 使用基于细胞的表型测定来测量 ATG9A 的 ATG9A 运输的分子调节剂 分布作为 AP-4 函数的替代。我们确定了 ATG9A 分布的几种调制器。我会测试 假设这些在体外恢复 AP-4-HSP 神经元中 ATG9A 的运输和功能 患者和 ap4b1-/- 斑马鱼模型体内。 该提案提出了一个为期五年的研究职业发展计划，重点研究 HSP 中的 AP-4 扩大对蛋白质运输和自噬在这组细胞中的作用的理解的广度和深度 疾病。目标是建立一个跨组织筛选平台来识别和开发新的 用于治疗 HSP 的蛋白质运输调节剂。 该候选人目前是波士顿儿童医院神经内科儿童神经内科的住院医师 医院和哈佛医学院。概述的提案建立在候选人之前的研究基础上 蛋白质运输、自噬和神经变性，并整合了细胞生物学的新专业领域， 先进的显微镜、iPSC 衍生的神经元和基因工程斑马鱼来模拟人类 疾病。这些技能体现在他的指导团队中，该团队由主要导师 Mustafa Sahin 博士和 由 Craig Blackstone 博士、Thomas Schwarz 博士、Annapurna Poduri 博士组成的科学咨询委员会 和伦纳德·佐恩博士。拟议的实验和教学工作将为候选人定位独特的 一套跨学科技能将使他能够过渡到作为该领域的医师科学家的独立地位 转化神经科学在儿童期发病的神经系统疾病中的应用。