Molecular Mechanisms Regulating BDNF Research

调节 BDNF 的分子机制研究

• 批准号: 8733294
• 负责人: CHERYL F DREYFUS
• 金额: $ 29.83万
• 依托单位: RBHS-ROBERT WOOD JOHNSON MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-03 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8733294
• 关键词: Acute; Adolescent; Animals; Anxiety; Astrocytes; Autistic Disorder; Axon; Binding; Brain; Brain-Derived Neurotrophic Factor; Cell physiology; Cleaved cell; Dendrites; Detection; Development; Disease; Electrons; Elements; Epitopes; Family member; Generations; Goals; Growth; Hippocampus (Brain); Human; In Vitro; Instruction; Knock-in Mouse; Light; Location; Maps; Measures; Mediating; Microscopic; Molecular; Molecular Chaperones; Morphology; Mus; Neonatal; Nervous system structure; Neuroglia; Neuronal Differentiation; Neuronal Plasticity; Neurons; Neurotrophic Tyrosine Kinase Receptor Type 2; Pathway interactions; Play; Process; Protein Isoforms; Reagent; Recombinants; Research; Resources; Role; Secretory Vesicles; Signal Transduction; Site; Sorting - Cell Movement; Specific qualifier value; Synapses; Synaptic Cleft; Synaptic Transmission; Techniques; Time; Vertebral column; Vesicle; density; depressive symptoms; human disease; in vivo; member; neurotransmission; postnatal; postsynaptic; presynaptic; promoter; research study; small hairpin RNA; sortilin; tool; trafficking; transcriptional coactivator p75

BDNF induces structural and functional changes in central neurons to modulate synaptic efficacy; our goal is to identify molecular mechanisms that regulate BDNF targeting and release at synapses to modulate neurotransmission. BDNF is synthesized as a precursor, proBDNF, sorted to a regulated secretory pathway, and released in an activity-dependent manner. At the synapse, proBDNF can bind selectively to p75 to induce LTD, and potentially reduce spine density and dendritic complexity. If proBDNF is converted to mature BDNF in the secretory vesicle or synaptic cleft, TrkB is selectively activated to enhance synaptic transmission and promote axonal branching and dendritic growth. Thus, mechanisms that regulate conversion of proBDNF to mature BDNF, and regulate trafficking to dendrites or axons critically modulate structural and functional neuronal plasticity. We have generated knock-in mice expressing HA-tagged BDNF to markedly enhance detection of endogenous BDNF. We have also identified intracellular chaperones, including sortilin, and other sortilin family members that bind proBDNF. With these tools, three interrelated aims are proposed: (1) Using neurons from the BDNF-HA mouse, identify if conversion of proBDNF to mature BDNF occurs during sorting to secretory vesicles, or following vesicle fusion and release. We postulate that the location of BDNF conversion may differ among neuronal subtypes. (2) We will identify the sortilin family members that chaperone proBDNF to the constitutive or regulated secretory pathways, and to dendrites or axons. We posit that different sortilin members direct intracellular trafficking to different subcellular compartments, delivery to the synapse, and regulate cleavage to mature BNDF. Using BDNF-HA mouse, and acute silencing of different chaperones, we will assess the developmentally regulated changes in the ratio of proBDNF/mature BDNF release, and in retrograde and anterograde traffiking of BDNF isoforms. (3) We will generate knock-in mice to conditionally delete relevant sortilin family members. These animals will permit us to dissect the roles of select BDNF chaperones in regulating BDNF levels, targeting to axons or dendrites, and effects on neuronal morphology and connectively in the intact, postnatal brain.

BDNF诱导中央神经元的结构和功能变化，以调节突触功效。我们的目标 是确定调节BDNF靶向和在突触下释放以调节的分子机制 神经传递。 BDNF被合成为前体ProbDNF，分类为调节的分泌途径， 并以活动依赖的方式发布。在突触，ProbDNF可以选择性地结合到P75至 诱导有限公司，并有可能降低脊柱密度和树突复杂性。如果probdnf转换为 分泌囊泡或突触裂缝中的成熟BDNF选择性激活以增强突触 传递和促进轴突分支和树突生长。因此，调节的机制 将probdnf转换为成熟的bdnf，并调节贩运的树突或轴突严重调节 结构和功能性神经元可塑性。我们已经产生了表达HA标签BDNF的敲门鼠 显着增强了内源性BDNF的检测。我们还确定了细胞内伴侣， 包括Tortilin和其他绑定ProbDNF的Tortilin家族成员。使用这些工具，三个相互关联 提出了目的：（1）使用BDNF-HA鼠标的神经元，确定probdnf的转换是否 成熟的BDNF在分类囊泡或囊泡融合和释放之后发生。我们 假设BDNF转换的位置在神经元亚型之间可能有所不同。 （2）我们将确定 与本构或受监管的分泌途径相关的替补家族成员，并 树突或轴突。我们认为，不同的sortilin成员将细胞内贩运引导到不同 亚细胞隔室，传递到突触，并调节成熟BNDF的裂解。使用bdnf-ha 小鼠和不同伴侣的急性沉默，我们将评估受发展调节的变化 以ProbDNF/成熟BDNF释放的比率，以及BDNF的逆行和顺行贩运 同工型。 （3）我们将生成敲入小鼠以有条件地删除相关的Tortilin家族成员。这些 动物将允许我们剖析精选的BDNF伴侣在调节BDNF水平的作用，以 轴突或树突，以及对神经元形态的影响，并在完整的产后大脑中连接。