Role of atlastin-1 in axonal development and degeneration of human neurons

atlastin-1 在人类神经元轴突发育和变性中的作用

基本信息

批准号：
8772197
负责人：
XUE-JUN LI
金额：
$ 19.88万
依托单位：
UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2016-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8772197
关键词：
Affect Amyotrophic Lateral Sclerosis Axon Axonal Transport Bone Morphogenetic Proteins Cells Corticospinal Tracts Data Defect Development Disease Distal Dynamin Endoplasmic Reticulum Fibroblasts Genes Goals Guanosine Triphosphate Phosphohydrolases Hereditary Spastic Paraplegia Hip region structure Human In Vitro Individual Inherited Interneurons Leg Length Lower Extremity Mediating Modeling Motor Motor Neurons Movement Muscle Mutation Neurologic Neurons Neuropathy Pathogenesis Pathology Patients Phenotype Play Proteins Rattus Role Signal Transduction Spinal System Testing axonal degeneration axonopathy base bone morphogenetic protein receptors cell type early onset human embryonic stem cell human stem cells induced pluripotent stem cell insight knock-down member novel therapeutics overexpression procollagen C-endopeptidase public health relevance research study therapeutic target therapy development tool trafficking

项目摘要

DESCRIPTION (provided by applicant): Impaired axonal development and degeneration are implicated in many debilitating disorders, such as hereditary spastic paraplegia (HSP), amyotrophic lateral sclerosis, and periphery neuropathy. HSP is caused by distal axonopathy involving the longest corticospinal tract axons, leading to spasticity and weakness of the lower extremities. The most common early-onset form of HSP, SPG3A, is caused by mutations in the atlastin-1 gene. This gene encodes atlastin-1 protein, which is a member of the dynamin-related large GTPase superfamily. Knockdown of atlastin-1 in rat cortical neuron in vitro cultures inhibits the axonal outgrowth and elongation. However, how altered atlastin-1 activity leads to axonal defects and why specific axons degenerate in HSP patients are largely unclear. The goal of this proposed study is to establish human neuronal models of SPG3A to delineate the mechanisms underlying the axonal defects in HSP. This study's hypothesis is that atlastin mutations result in axonal defects selectively in cortical projection neurons (cortical PNs), and this effect is mediated mainly by dysregulated bone morphogenetic protein (BMP) signaling. This hypothesis will be tested by pursuing the following two aims: 1) to examine the axonal outgrowth and transport in cortical PNs derived from iPSCs that are generated from SPG3A patients and normal individuals (as controls); 2) to delineate the role of BMP signaling in the axonal defects in SPG3A. By comparing the axonal defects, atlastin-1 activity, and BMP signaling alterations in cortical PNs, cortical interneurons, and spinal motor neurons derived from control and SPG3A iPSCs, this study will be able to delineate the cell type-specific defects in HSP and the underlying mechanisms. The cause-effect relationship between loss of atlastin function and axonal phenotypes will be confirmed by knocking down atlastin-1 in wild-type (WT) neurons and by expressing WT atlastin-1 in SPG3A iPSCs. Moreover, rescue experiments will be performed to identify the potential approaches for rescuing the axonal pathology, such as overexpression of atlastin or treatment with BMP antagonists. Together, this study will provide valuable insights into the roles of atlastin-1 and BMP signaling in HSP pathology and developing new therapeutics for rescuing the axonal degeneration in HSP.

描述（由申请人提供）：轴突发育和变性受损与许多令人衰弱的疾病有关，例如遗传性痉挛性瘫痪（HSP），肌萎缩性侧面硬化症和周围神经性疾病。 HSP是由涉及最长皮层脊髓轴突的远端轴突病引起的，导致下肢的痉挛和无力。 HSP SPG3A最常见的早期发作形式是由atlastin-1基因突变引起的。该基因编码Atlastin-1蛋白，该蛋白是动力蛋白相关的大GTPase超家族的成员。大鼠皮质神经元在体外培养物中敲低atlastin-1抑制轴突的产物和伸长率。然而，atlastin-1活性改变如何导致轴突缺陷以及为什么在HSP患者中变性的特定轴突在很大程度上不清楚。这项拟议的研究的目的是建立SPG3A的人类神经元模型，以描述HSP中轴突缺陷的基础机制。这项研究的假设是，在皮质投射神经元（皮质PN）中选择性地导致轴突缺陷，并且该作用主要是由失调的骨形态发生蛋白（BMP）信号传导介导的。该假设将通过追求以下两个目的来检验：1）检查源自SPG3A患者和正常个体（作为对照）的IPSC的皮质PN的轴突生长和运输； 2）描述BMP信号在SPG3A中轴突缺陷中的作用。通过比较轴突缺陷，atlastin-1活性以及皮质PN，皮质中间神经元和源自对照和SPG3A IPSC的脊髓运动神经元的BMP信号传导改变，该研究将能够描绘出HSP中的细胞类型特异性缺陷以及基础机制。通过在野生型（WT）神经元中击倒Atlastin-1以及通过在SPG3A IPSC中表达WT Atlastin-1，可以证实atlastin功能和轴突表型之间的因果关系。此外，将进行救援实验，以确定挽救轴突病理的潜在方法，例如atlastin的过表达或用BMP拮抗剂治疗。总之，这项研究将为Atlastin-1和BMP信号在HSP病理学中的作用提供宝贵的见解，并开发新的治疗剂，以营救HSP中的轴突变性。