Exploring how cells generate and release distinct subpopulations of dense-core vesicles

探索细胞如何产生和释放不同的致密核心囊泡亚群

基本信息

批准号：
10679873
负责人：
Michael Ailion
金额：
$ 23.33万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-04-15 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10679873
关键词：
Address Afferent Neurons Behavior Behavior Control Behavior Disorders Beta Cell Biogenesis Biogenic Amines Biological Biological Models Caenorhabditis elegans Calcium Cell Line Cells Cellular biology Characteristics Data Defect Dense Core Vesicle Disease Dopamine Electron Microscopy Endocrine Endosomes Family Functional disorder Future Generations Heterogeneity Individual Insulin Investigation Knowledge Lipids Mental disorders Metabolic Diseases Metabolism Molecular Mood Disorders Nematoda Nerve Growth Factors Neurologic Neuromodulator Neurons Neuropeptides Norepinephrine Organelles Pathway interactions Pattern Peptides Physiological Physiology Population Process Protein Isoforms Proteins Rattus Recycling Role Sensory Signaling Molecule Site Sorting Structure of beta Cell of islet System Testing Vesicle cell type experimental study insight member monoamine nervous system disorder peptide hormone protein complex rab GTP-Binding Proteins segregation sensor synaptotagmin vesicular release

项目摘要

Project summary When examined by electron microscopy, neurons can be seen to carry organelles that look like little black dots. These black dots are called dense-core vesicles and they carry many important transmitters that act as neuromodulators, including neuropeptides, nerve growth factors, and monoamines such as dopamine and norepinephrine. Such dense-core vesicle cargos regulate a wide array of behaviors, and defects in such cargos can contribute to numerous mood disorders and other neurological conditions. However, little is understood about the cell biology of how dense-core vesicles are made, acquire cargos and mature, are trafficked to release sites, and ultimately released. Thus, the little black dots in neurons are really a big black box. Adding to the mysteries and complexity of these organelles, many neurons carry multiple dense-core vesicle cargos in the same cell. Are these different cargos copackaged together in the same dense-core vesicles or are they packaged separately in distinct vesicles? The answer to this question is surprisingly known in only a few cases, and the general pattern of copackaging versus segregation of distinct cargos is unclear, but is of key physiological relevance as it determines whether different dense-core vesicle cargos are coreleased or can be released independently. Additionally, in cases where distinct dense-core vesicle subpopulations are known to exist in the same cell, it is unclear how these distinct populations are generated and how cargos are differentially sorted. To begin to address these gaps in understanding, here we aim to establish two model systems for the study of distinct dense-core vesicle populations in the same cell: the ASI sensory neuron in the nematode C. elegans and the rat pancreatic beta-cell line 832/13. Our preliminary data show that members of a known dense-core vesicle biogenesis and maturation pathway, the Rab2/EARP pathway, are required for one subpopulation of dense-core vesicles in both the ASI neuron and the 832/13 cell line, but not for another subpopulation in the same cell. In Aim 1, we will further define the requirements for members of the Rab2/EARP pathway in the biogenesis and maturation of distinct dense-core vesicle subpopulations in the ASI neuron and 832/13 cells. Additionally, we will perform candidate screens in an attempt to identify factors required for the Rab2/EARP-independent generation of dense-core vesicles in both cell types. In Aim 2, we will test the hypothesis that different subpopulations of dense-core vesicles are marked by different isoforms of the synaptotagmin family of calcium sensors. We will also determine whether these synaptotagmins control the release of distinct dense-core vesicle subpopulations. In summary, this project will identify the basic molecules required for the generation and release of distinct subpopulations of dense-core vesicles in the same cell, and set the stage for more mechanistic investigations into how these processes occur.

项目概要当通过电子显微镜检查时，可以看到神经元携带看起来像小黑点的细胞器。这些黑点被称为致密核心囊泡，它们携带许多重要的递质，充当神经调节剂，包括神经肽、神经生长因子和单胺，如多巴胺和去甲肾上腺素。这种致密核心囊泡货物调节多种行为，并且这些缺陷货物可能导致多种情绪障碍和其他神经系统疾病。然而，很少的是了解致密核心囊泡如何制造、获取货物和成熟的细胞生物学被传送到发布网站，并最终被发布。因此，神经元中的小黑点实际上是一个大黑点盒子。许多神经元携带多个致密核心，这增加了这些细胞器的神秘性和复杂性。同一细胞中的囊泡货物。这些不同的货物是否被共同包装在同一个致密核心中？囊泡还是它们单独包装在不同的囊泡中？这个问题的答案出人意料地众所周知仅在少数情况下，并且不同货物共同包装与隔离的一般模式尚不清楚，但具有关键的生理相关性，因为它决定了不同的致密核心囊泡货物是否是共同发布或可以独立发布。此外，如果存在明显的致密核心囊泡已知亚群存在于同一细胞中，但尚不清楚这些不同的亚群是如何产生的以及货物如何进行差异化分类。为了开始解决这些理解上的差距，我们的目标是建立两个模型系统来研究同一细胞中不同的致密核心囊泡群：ASI 线虫线虫和大鼠胰腺 β 细胞系 832/13 中的感觉神经元。我们的初步数据显示已知的致密核心囊泡生物发生和成熟途径的成员 Rab2/EARP ASI 神经元和 832/13 细胞中的一个致密核心囊泡亚群都需要这一途径线，但不适用于同一细胞中的另一个亚群。在目标1中，我们将进一步明确要求 Rab2/EARP 通路成员在不同致密核心囊泡的生物发生和成熟中的作用 ASI 神经元和 832/13 细胞中的亚群。此外，我们将在尝试确定在两种细胞中独立于 Rab2/EARP 生成致密核心囊泡所需的因素细胞类型。在目标 2 中，我们将检验以下假设：不同的致密核心囊泡亚群被标记由钙传感器突触结合蛋白家族的不同亚型产生。我们还将确定这些是否突触结合蛋白控制不同的致密核心囊泡亚群的释放。综上所述，本项目将识别致密核不同亚群的产生和释放所需的基本分子同一细胞中的囊泡，并为更多机制研究这些过程如何奠定基础发生。