Imaging nerve growth factor signal transduction in live neurons

活神经元中神经生长因子信号转导的成像

• 批准号: 7223656
• 负责人: Bianxiao Cui
• 金额: $ 5.75万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-12-01 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7223656
• 关键词: Alzheimer' s Disease; Amyloid beta-Protein Precursor; Atrophic; Axon; Axonal Transport; Binding; Brain; C-terminal; Cells; Cholinergic Agents; Chromosomes, Human, Pair 16; Color; Defect; Down Syndrome; Endosomes; Energy Supply; Event; Fluorescence; Frequencies; Genes; Green Fluorescent Proteins; Image; Imaging Techniques; Individual; Label; Lead; Length; Life; Link; Localized; Location; Maintenance; Measures; Microtubules; Mitochondria; Modeling; Motor; Movement; Mus; Nerve Growth Factors; Neurons; Neurotrophic Tyrosine Kinase Receptor Type 1; Numbers; Pathogenesis; Patients; Pattern; Presynaptic Terminals; Protein Overexpression; Proteins; Quantum Dots; Rate; Reporting; Research Personnel; Resolution; Role; Severities; Signal Pathway; Signal Transduction; Specific qualifier value; Speed; Syndrome; System; Testing; Time; Travel; basal forebrain; basal forebrain cholinergic neurons; cellular imaging; cholinergic; fluorescence imaging; mouse Ts65Dn; nanometer; neuronal cell body; programs; retrograde transport; single molecule; trafficking

DESCRIPTION (provided by applicant): Our broad objective is to understand the mechanisms by which the nerve growth factor (NGF) signal is propagated from the axon terminal to the cell body. NGF retrograde signaling is critical for the survival, differentiation, and maintenance of certain types neurons. Disrupted NGF retrograde transport was reported to contribute to the loss of the basal forebrain cholinergic (BFC) neurons in the brains of patients with Alzheimer's Disease or Down's Syndrome. This project will use advanced imaging techniques to directly visualize NGF transport in live neurons in real time. We focus on exploring dynamic features of NGF transport in normal and Down's Syndrome mice. The aims are: 1. Characterize the movement of NGF-containing endosomes in axons and define their pausing mechanism(s), by using quantum dot conjugated NGF to track endosomal movements with nanometer resolution. 2. Determine whether NGF-lacking endosomes are present, whether they are relevant for NGF signaling, and whether there are alternative signaling pathways independent of endosomal transport, by marking the NGF-lacking endosomes with photo-activatable green fluorescence proteins that are fused to the C-terminal of TrkA receptor. 3. Identify the abnormal features of disrupted NGF transport in Down Syndrome mouse neurons, by characterizing individual features of transport dynamics, which include the average speed, the moving speed, the pausing duration, and the pausing frequency. 4. Determine how amyloid precursor protein overexpression leads to the abnormal NGF retrograde transport in Down Syndrome mouse by examining how overexpression of amyloid precursor protein in DS mice might cause defective structural or axonal features that lead to disrupted NGF transport. Achieving those aims will increase our understanding of how NGF signal is propagated in normal and degenerative neurons. More broadly, those studies will contribute to elucidate the pathogenesis of Alzheimer's disease and Down syndrome.

描述（由申请人提供）： 我们的总体目标是了解神经生长因子 (NGF) 信号从轴突末端传播到细胞体的机制。 NGF 逆行信号传导对于某些类型神经元的生存、分化和维持至关重要。据报道，NGF 逆行运输中断会导致阿尔茨海默病或唐氏综合症患者大脑中基底前脑胆碱能 (BFC) 神经元的丧失。该项目将使用先进的成像技术直接实时可视化活体神经元中的 NGF 运输。我们专注于探索正常小鼠和唐氏综合症小鼠 NGF 转运的动态特征。目标是： 1. 通过使用量子点缀合的 NGF 以纳米分辨率跟踪内体运动，表征轴突中含有 NGF 的内体运动并定义其暂停机制。 2. 通过用融合到 TrkA 受体 C 末端的光激活绿色荧光蛋白标记缺乏 NGF 的内体，确定是否存在缺乏 NGF 的内体、它们是否与 NGF 信号传导相关，以及是否存在独立于内体运输的替代信号通路。 3. 通过表征运输动力学的个体特征，包括平均速度、移动速度、暂停持续时间和暂停频率，识别唐氏综合症小鼠神经元中 NGF 运输中断的异常特征。 4. 通过检查 DS 小鼠中淀粉样前体蛋白的过度表达如何导致结构或轴突特征缺陷，从而导致 NGF 转运中断，确定淀粉样前体蛋白过度表达如何导致唐氏综合症小鼠中异常的 NGF 逆行转运。实现这些目标将增加我们对 NGF 信号如何在正常和退行性神经元中传播的理解。更广泛地说，这些研究将有助于阐明阿尔茨海默病和唐氏综合症的发病机制。