Spatial Restriction of Apoptotic Machinery during Neuronal Apoptosis and Pruning

神经元凋亡和修剪过程中凋亡机制的空间限制

基本信息

批准号：
10417219
负责人：
Mohanish P Deshmukh
金额：
$ 38.28万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-03 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10417219
关键词：
Apoptosis Apoptotic Architecture Area Axon Axotomy Behavioral Brain CASP1 gene CASP3 gene CASP6 gene Caspase Caspase Inhibitor Cells Defect Development Devices Dimerization Event Excision Exhibits Exposure to Gene Family Goals Image Injury Mediating Mediator of activation protein Messenger RNA Microfluidics Microscopy Modeling Molecular Mus NAD+ Nucleosidase Nerve Degeneration Nervous system structure Neurons Neurosciences Pathway interactions Physiological Point Mutation Puma Research Resolution Rest Role Signal Transduction Structure axon injury axonal degeneration deprivation experimental study in vivo mRNA Expression neurodevelopment neuron apoptosis neuronal cell body novel protein expression response segregation synaptic pruning

Apoptosis Apoptotic Architecture Area Axon Axotomy Behavioral Brain CASP1 gene CASP3 gene CASP6 gene Caspase Caspase Inhibitor Cells Defect Development Devices Dimerization Event Excision Exhibits Exposure to Gene Family Goals Image Injury Mediating Mediator of activation protein Messenger RNA Microfluidics Microscopy Modeling Molecular Mus NAD+ Nucleosidase Nerve Degeneration Nervous system structure Neurons Neurosciences Pathway interactions Physiological Point Mutation Puma Research Resolution Rest Role Signal Transduction Structure axon injury axonal degeneration deprivation experimental study in vivo mRNA Expression neurodevelopment neuron apoptosis neuronal cell body novel protein expression response segregation synaptic pruning

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项目摘要

Project Summary/Abstract Neurons are capable of activating pathways that induce either the degeneration of the entire cell by apoptosis or to selectively degenerate only the axons by pruning. While the main components of the caspase activating machinery during apoptosis and pruning have been identified, a fundamental question of whether the apoptotic machinery is activated throughout the neuronal soma and axons, or is spatially restricted, during these events remains unknown. This question is most relevant in the context of pruning where one predicts the apoptotic machinery to be localized to the targeted axons undergoing degeneration. However, we were surprised to find an unexpected spatial restriction of caspase activation even during apoptosis, where we found these to be restricted primarily to the soma, even though both soma and axons degenerate. In this proposal, we will mechanistically examine the spatial localization of the apoptotic machinery in neurons during apoptosis and pruning. We will utilize neurons cultured in microfluidic chamber devices to allow for the spatial segregation and manipulation of neuronal somas and axons. Our hypothesis is that during apoptosis and pruning, the restricted caspase activity causes the “physiological axotomy” of axons, activating the Sarm1-mediated axotomy pathway of axon degeneration. The concept that the developmental pathways of apoptosis and pruning can cause axotomy is novel because these pathways were considered to be distinct from the injury-induced axotomy pathway. In Aim 1, we will define the spatial restriction of the apoptotic machinery in neurons during apoptosis and axon pruning. In Aim 2, we focus on examining the function of Sarm1 during apoptosis and axon pruning. In Aim 3, we will investigate the Sarm1-deficient mice for pruning defects in vivo and evaluate if these mice exhibit behavioral deficits. This project opens exciting areas of research not only because of its new concepts for apoptosis and pruning, but also because it brings into focus a developmental function of Sarm1 that is beyond its recognized role in axon injury.

项目摘要/摘要神经元能够激活诱导整个细胞变性的途径细胞凋亡或仅通过修剪选择性地退化轴突。而caspase的主要组成部分已经确定了在凋亡和修剪过程中激活机械的机械，这是一个基本问题在整个神经元体内和轴突中都激活凋亡机器，或在空间上受到限制。这些事件仍然未知。在修剪的背景下，这个问题最相关凋亡机制将定位于进行变性的靶向轴突。但是，我们是惊讶地发现即使在细胞凋亡期间也发现了对胱天冬酶激活的意外空间限制，我们发现即使躯体和轴突都退化，这些这些主要限制在体内。在此提案中，我们将机械地检查凋亡机制的空间定位凋亡和修剪过程中的神经元。我们将利用在微流体室设备中培养的神经元到允许神经元躯体和轴突的空间分离和操纵。我们的假设是在凋亡和修剪，受限的caspase活性导致轴突的“生理轴切开术”，激活轴突变性的SARM1介导的轴切开术途径。这个概念是凋亡和修剪会导致轴切开术是新颖的，因为这些途径被认为与损伤引起的轴切开术途径。在AIM 1中，我们将定义凋亡过程中神经元凋亡机制的空间限制轴突修剪。在AIM 2中，我们专注于检查凋亡和轴突修剪过程中SARM1的功能。 AIM 3，我们将研究用于修剪体内缺陷的SARM1缺陷小鼠，并评估这些小鼠是否存在展示行为定义。该项目开辟了令人兴奋的研究领域，不仅是因为其新概念用于细胞凋亡和修剪，也是因为它使SARM1的发展功能重点是超越其在轴突损伤中的公认作用。