Role of matrix metalloproteinases in synaptic plasticity

基质金属蛋白酶在突触可塑性中的作用

• 批准号: 7303382
• 负责人: GEORGE W. HUNTLEY
• 金额: $ 36.02万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-04 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7303382
• 关键词: Actins; Active Sites; Acute; Address; Adhesions; Adult; Area; Behavioral; Biochemical; Brain; Cell surface; Chemosensitization; Chromosome Pairing; Cytoskeleton; Data; Dendritic Spines; Electric Stimulation; Employee Strikes; Endopeptidases; Extracellular Matrix; Extracellular Matrix Proteins; Family; Functional disorder; Gelatinase B; Goals; Hippocampus (Brain); Image; Injury; Integrins; Learning; Life; Link; Matrix Metalloproteinases; Mediating; Memory; Methods; Molecular; Morphology; Neurons; Peptide Hydrolases; Personal Satisfaction; Physiology; Plastics; Process; Proteins; Proteolysis; Protocols documentation; Publishing; Rattus; Reagent; Regulation; Role; Signal Transduction; Slice; Synapses; Synaptic plasticity; Testing; Thinking; Time; Tissues; Urethane; Vertebral column; Whole-Cell Recordings; base; cell motility; dentate gyrus; extracellular; in vivo; insight; long term memory; loss of function; novel; receptor; research study; response; skills; two-photon

DESCRIPTION (provided by applicant): The long-term goal is to understand mechanisms of synaptic functional and structural plasticity in brain. This is important because such plasticity represents cellular mechanisms enabling memory. Matrix metalloproteinases (MMPs) are a family of extracellular peptidases whose targets include extracellular matrix (ECM). Canonically, they function to remodel the pericellular microenvironment. Here, we address the novel hypothesis that in brain, regulated MMP-mediated extracellular proteolysis coordinates synaptic signaling and remodeling during synaptic and behavioral plasticity. In Aim 1, regulation and activation of MMP-9 during synaptic plasticity is studied in vivo using electrical stimulation protocols and field recordings to elicit different forms of synaptic plasticity in area CA1. Pharmacological methods are used to establish the timecourse over which levels of MMP-9 protein and proteolytic activity are regulated; gain- and loss-of- function approaches are used to establish functional roles of MMP-9 in synaptic physiology and plasticity; novel reagents and methods including the use of fluorescently tagged MMP active-site directed probes are used to determine if MMP-9 is activated globally during plasticity or locally in relationship to plastic synapses. In Aim 2, effects of active MMP-9 on neuronal form and function are tested. Gain- and loss-of- function approaches combined with two-photon time-lapse imaging of living dendritic spines and whole-cell recording will be applied to acute hippocampal slices to: a) characterize changes in spine motility, morphology and actin dynamics in relationship to MMP-mediated potentiation; and b) determine the relationship between MMP-9 mediated structural plasticity and integrin activation. In Aim 3, a hippocampal- dependent learning and memory task will be used in conjunction with subsequent biochemical, anatomical and loss-of-function approaches in order to determine: a) the timecourse and localization of learning-induced MMP-9 activation; and b) the effects of neutralizing proteolytic activity on strength of memory. The experiments will reveal new, fundamental roles for MMPs in normal brain function, and provide new insight into molecular mechanisms that regulate synaptic and behavioral plasticity.

描述（由申请人提供）：长期目标是了解大脑中突触功能和结构可塑性的机制。这一点很重要，因为这种可塑性代表了记忆的细胞机制。基质金属蛋白酶（MMPs）是一类以细胞外基质（ECM）为靶点的细胞外肽酶家族。典型地，它们的功能是重塑细胞周围的微环境。在这里，我们解决了新的假设，在大脑中，调节MMP介导的细胞外蛋白水解协调突触和行为可塑性过程中的突触信号和重塑。在目标1中，使用电刺激方案和场记录在体内研究了突触可塑性期间MMP-9的调节和激活，以引起CA 1区不同形式的突触可塑性。药理学方法用于建立MMP-9蛋白水平和蛋白水解活性被调节的时程;功能获得和丧失方法用于建立MMP-9在突触生理学和可塑性中的功能作用;使用新的试剂和方法，包括使用荧光标记的MMP活性位点定向探针，9在可塑性期间被全局激活，或与可塑性突触相关地被局部激活。在目的2中，测试活性MMP-9对神经元形式和功能的影响。将功能获得和丧失方法与活树突棘的双光子延时成像和全细胞记录相结合应用于急性海马切片，以：a）表征与MMP介导的增强相关的棘运动性、形态学和肌动蛋白动力学的变化;和B）确定MMP-9介导的结构可塑性和整合素活化之间的关系。在目的3中，海马依赖性学习和记忆任务将与随后的生物化学、解剖学和功能丧失方法结合使用，以确定：a）学习诱导的MMP-9活化的时间过程和定位;和B）中和蛋白水解活性对记忆强度的影响。这些实验将揭示MMPs在正常脑功能中的新的基本作用，并为调节突触和行为可塑性的分子机制提供新的见解。