Mechanisms Underlying Axonopathy in Hereditary Spastic Paraplegia

遗传性痉挛性截瘫轴突病的潜在机制

基本信息

批准号：
10463959
负责人：
Anjon Audhya
金额：
$ 37.54万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-05-01 至 2027-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10463959
关键词：
Address Adverse effects Affect Age Amyotrophic Lateral Sclerosis Animals Ataxia Atrophic Axon Biochemical Biochemistry Birth Brain CRISPR/Cas technology Cell Culture Techniques Cells Cerebral cortex Clinical Clustered Regularly Interspaced Short Palindromic Repeats Corticospinal Tracts Data Defect Dementia Development Disease Disease Progression Distal Drug Screening Electromyography Endosomes Equilibrium Escherichia coli Etiology Eukaryotic Cell Exhibits Filament Foundations Future Gait Gait abnormality Genes Genetic study Glutamates Glycine Goals Hereditary Spastic Paraplegia Histopathology Homeostasis Human Immunohistochemistry Impairment In Vitro Inhibitory Synapse Intermediate Filament Proteins Intermediate Filaments Intervention Length Lewy Bodies Limb structure Link Lower Extremity Maintenance Mediating Membrane Membrane Proteins Microtubules Modeling Molecular Motor Movement Muscle Weakness Mutation Nerve Degeneration Nerve Fibers Neuraxis Neurodegenerative Disorders Neurofilament Proteins Neuronal Dysfunction Neurons Neurotransmitters Onset of illness Organelles Paralysed Parkinson Disease Pathologic Patients Phenotype Physiological Physiology Play Positioning Attribute Process Proteins Proteomics Rattus Recombinant Proteins Research Resolution Rodent Rodent Model Role Scaffolding Protein Signal Transduction Solid Somatotype Spinal Cord Sprague-Dawley Rats Swelling Synapses Technology Testing Therapeutic Time Variant Work axon guidance axonal degeneration axonopathy base combat confocal imaging disease phenotype drug development early onset electron tomography genome editing gephyrin imaging approach in vivo induced pluripotent stem cell innovation kinematics live cell imaging motor control motor deficit nervous system disorder neurofilament neuronal excitability novel therapeutics overexpression programs receptor reconstitution spasticity spastin stem stem cell model therapeutic target time interval trafficking

项目摘要

Project Summary Axonal degeneration within the corticospinal tract leads to several neurological diseases, including hereditary spastic paraplegias (HSPs), which are a clinically and genetically heterogeneous group of gait disorders characterized by poor balance, spasticity, and progressive muscle weakness that can ultimately result in paralysis. Leveraging parallel animal (rat) and induced pluripotent stem cell (iPSC)-based models, our goal is to develop a better understanding of the pathomechanisms that underlie neurodegeneration resulting from mutations in genes that cause HSP, with a longer term goal of using these models as platforms to identify new therapeutics to combat disease. Using CRISPR-mediated genome editing, we have developed physiologically relevant models that recapitulate phenotypes exhibited by patients suffering from HSP. Specifically, CRISPR- modified rats expressing pathological variants of SPG4 (spastin) and SPG57 (TFG) demonstrate early onset hind limb spasticity and ataxia, which rapidly progresses to hind limb paralysis. Other rat models, including those harboring a truncation of SPG80 (UBAP1) identified previously in patients, exhibit later onset disease phenotypes, enabling us to examine disease progression in multiple, unique contexts. We now have an unprecedented opportunity to determine the mechanistic basis of the axonopathies observed. In particular, we plan to use high- resolution, live cell confocal imaging and electron tomography to test the hypothesis that changes in the trafficking of specific factors, including neurofilament proteins implicated previously in neurodegenerative disease, contribute to impaired neuronal function in HSP. We will also determine how neurofilament trafficking defects observed relate to disease onset based on a combination of electromyography studies, histopathology, and comprehensive gait and kinematic analysis of rodent movement as spasticity and muscle weakness ensues. Furthermore, we will determine mechanisms by which mutations that underlie HSP impact neuronal excitability, again using live cell imaging approaches, but also in vitro biochemistry and genetic studies. Collectively, this work will help to uncover several of the mechanisms that contribute to neuronal dysfunction observed in patients with HSP and lay the foundation for the future development of drug screening approaches.

项目摘要皮质脊髓段内的轴突变性会导致几种神经系统疾病，包括遗传性痉挛性截瘫（HSP）是临床和遗传性异构的步态群以不良平衡，痉挛和渐进性肌肉无力为特征的疾病，最终会导致在瘫痪中。利用平行动物（大鼠）和诱导多能干细胞（IPSC）模型，我们的目标是为了更好地理解对神经退行性基础的病理机制的理解引起HSP的基因突变，其长期目标是将这些模型用作平台以识别新对抗疾病的治疗疗法。使用CRISPR介导的基因组编辑，我们在生理上开发了患有HSP的患者表现出概括表型的相关模型。具体而言，crispr- 改良的大鼠表达SPG4（SPASTIN）和SPG57（TFG）的病理变异的大鼠展示了早期发作后肢痉挛和共济失调，迅速发展为后肢瘫痪。其他老鼠模型，包括具有先前在患者中鉴定的SPG80（UBAP1）的截断，表现出以后的发作表型，使我们能够在多种独特的环境中检查疾病进展。我们现在有一个前所未有的确定观察到的轴突病的机理基础的机会。特别是，我们计划使用高分辨率，活细胞共聚焦成像和电子断层扫描，以检验以下假设特定因素的运输，包括先前与神经退行性有关的神经丝蛋白疾病，导致HSP神经元功能受损。我们还将确定如何进行神经丝贩运观察到的缺陷与疾病发作有关，基于肌电图研究，组织病理学的结合，随之而来的是啮齿动物运动的全面步态和运动学分析。此外，我们将确定HSP影响神经元兴奋性的突变的机制，再次使用活细胞成像方法，还使用体外生物化学和遗传研究。总的来说，这工作将有助于发现几种导致患者观察到神经元功能障碍的机制 HSP并为未来的药物筛查方法奠定了基础。