Uncovering the mechanisms of Ephexin5 function in dendritic spine plasticity and Alzheimer's disease

揭示 Ephexin5 在树突棘可塑性和阿尔茨海默病中的作用机制

• 批准号: 10604540
• 负责人: Samuel Petshow
• 金额: $ 4.01万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10604540
• 关键词: Acute; Affect; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease patient; Amyloid beta-Protein; Attention; Bicuculline; Binding; Biosensor; Brain; Communication; Coupled; Data; Data Set; Dendritic Spines; Disease; Excitatory Synapse; Exposure to; Fluorescence Microscopy; Fluorescence Resonance Energy Transfer; Glutamates; Goals; Guanosine Triphosphate Phosphohydrolases; Hippocampus; Homologous Gene; Image; Individual; Knockout Mice; Knowledge; Learning; Ligation; Liquid Chromatography; Mass Spectrum Analysis; Measures; Mediating; Memory; Memory Loss; Memory impairment; Mentors; Mentorship; Microscopic; Molecular; Mus; Neurodegenerative Disorders; Neurons; Optics; Pathway interactions; Pattern; Persons; Phosphorylation; Phosphorylation Site; Phosphotransferases; Physiological; Physiology; Play; Process; Proteins; Regulation; Research Project Grants; Role; Sampling; Signal Pathway; Signal Transduction; Signal Transduction Induction; Site; Slice; Structure; Substrate Specificity; Synapses; Technical Expertise; Testing; Time; Tissue Sample; Tissues; Transfection; Vertebral column; Writing; cell injury; cognitive ability; density; ephexin; experimental study; fighting; fluorescence lifetime imaging; hippocampal pyramidal neuron; in vitro Model; insight; knock-down; live cell imaging; memory acquisition; mimetics; mouse model; mutant; neurotransmission; new therapeutic target; preference; promoter; protein function; protein structure; response; rho GTP-Binding Proteins; sensor; skills; spatiotemporal; tandem mass spectrometry; therapeutic target; training project; two-photon

ABSTRACT / PROJECT SUMMARY Alzheimer’s Disease (AD) is associated with a progressive loss of dendritic spines, microscopic dendritic structures that serve as the sites of synaptic communication and are essential for the storage of memory. Levels of the RhoGEF Ephexin5, a regulator of dendritic spine density, appear to be key in facilitating AD-induced dendritic spine loss. Much about the substrate specificity of Ephexin5 and the regulation of Ephexin5 activity remain unknown. The goal of this project is to determine the mechanisms by which Ephexin5 signaling occurs in normal physiology and disease. It is my hypothesis that E5 undergoes a phosphorylation- dependent shift in substrate specificity from RhoA to Rac1/Cdc42, relevant to its role in regulating spine plasticity and contributing to the physiology of AD. Using 2-photon fluorescence lifetime imaging coupled with genetically encoded FRET biosensors, I will optically probe the activity of GTPases in live tissue. I will define the substrate specificity of neuronal E5 under normal physiological contexts, and in a model of AD-induced cellular damage. Using mass spectrometry, I will determine if phosphorylation of Ephexin5 changes during neuronal signaling or in an AD-like cellular state, and using phosphomutant analysis I will examine how phosphorylation influences E5 substrate specificity. My results will further the knowledge of the molecular mechanisms of learning and memory and have the potential to identify novel therapeutic targets for AD. Training for this project will take place at UC Davis, with the support of my mentor and Sponsor, Karen Zito, an expert in the live-imaging of synapses, and Co-sponsor James Trimmer, and expert in neuronal protein structure and function. I will acquire key technical skills in advanced live-cell imaging and mass spectrometry, which will aid in the completion of this research project. Additionally I will hone skills of mentorship, management, communication, and writing.

摘要/项目总结