Matrix Metalloproteinases and Regenerative Plasticity Following Brain Injury

脑损伤后的基质金属蛋白酶和再生可塑性

• 批准号: 7441317
• 负责人: Linda L. Phillips
• 金额: $ 37.25万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-15 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7441317
• 关键词: Accounting; Activities of Daily Living; Acute; Agrin; American; Antibodies; Antiplasmin; Astrocytes; Bilateral; Binding; Binding Sites; Biological Assay; Brain; Brain Injuries; Caseins; Cholera Toxin; Chromosome Pairing; Cytolysis; Deafferentation procedure; Dose; Drug or chemical Tissue Distribution; Electrophysiology (science); Enzymes; Excitatory Postsynaptic Potentials; Exposure to; Extracellular Matrix; Extracellular Matrix Proteins; FN-439; Fiber; Fibroblast Growth Factor 2; Fibroblast Growth Factor Receptor 2; Fibroblast Growth Factor Receptors; Functional disorder; Gelatin Zymography; Gelatinase A; Gelatinases; Glial Fibrillary Acidic Protein; Growth Cones; Growth Factor; Health; Hippocampus (Brain); Immunohistochemistry; Immunoprecipitation; In Situ Hybridization; Individual; Inhibition of Matrix Metalloproteinases Pathway; Injury; Label; Lesion; Liquid substance; Localized; Long-Term Potentiation; MMP3 gene; Matrix Metalloproteinase Inhibitor; Matrix Metalloproteinases; Mediating; Membrane; Methods; Microglia; Modeling; Molecular Profiling; N-Cadherin; Neurons; Outcome; Percussion; Phase; Physiological; Plasmin; Plasmin Inhibitor; Plasminogen; Presynaptic Terminals; Property; Proteins; RNA Splicing; Recovery; Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Transduction; Slice; Small Interfering RNA; Source; Spatial Distribution; Stromelysin 1; Synapses; Synapsins; Synaptic plasticity; Synaptophysin; System; Techniques; Testing; Time; Tissues; Traumatic Brain Injury; Variant; Western Blotting; axon growth; axonal sprouting; base; collagenase; day; density; dentate gyrus; enzyme activity; enzyme substrate; extracellular; functional status; human PTPRT protein; in vivo; indexing; inhibitor/antagonist; knock-down; mRNA Expression; novel strategies; phosphacan; postsynaptic; presynaptic; protein expression; receptor; research study; response; synaptogenesis

Millions of Americans are victims of traumatic brain injury (TBI) every year, making it a serious health challenge. TBI often involves significant axonal injury with attendant neuronal deafferentation and synaptic loss. While the brain has an inherent capacity for synaptic reorganization, this plasticity often fails after TBI, resulting in serious functional deficits. We have recently examined the role of extracellular matrix (ECM) proteins during reactive synaptogenesis induced by TBI. Our results showed that certain ECM proteins and their regulatory matrix metalloproteinases (MMPs) strongly influence the extent of recovery achieved after TBI. In these studies we contrasted ECM/MMP response in a recovering adaptive injury (unilateral entortiinal cortical lesion or DEC) and a non-recovering maladaptive insult (fluid percussion TBI + bilateral entorhinal cortical lesion orTBI+BEC). Two gelatinases (MMPs 2,9), stromelysin-1 (MMP 3) and the MMP activator plasmin all showed shifts in expression and function which correlated with different phases of reactive synaptogenesis. We also found that aberrant MMP activation was associated with failed plasticity after TBI+BEC. When MMP inhibitors were applied, plasticity was altered either positively or negatively depending upon time of dosing and complexity of injury. Given these results, we now posit that specific matrix enzyme/substrate/effector groups mediate the different phases of pre and postsynaptic recovery, as well as the subsequent stabilization of nascent synapses after injury. By contrasting the different profiles of these matrix proteins following adaptive UEC and maladaptive TBI+BEC, we will determine if individual protein dysfunction at specific phases of synaptogenesis can account for the variable extent of recovery. We will test the facilitative role of MMP3/agrin/FGF over the initial axonal sprouting phase of synaptic recovery, plasmin/phosphacan/(3-catenin during the subsequent synaptogenic period, and MT-5MMP/Ncadherin/ a-catenin at synapse stabilization. In each case we will document protein and mRNA expression, distribution in the synapse microenvironment and binding interactions. Finally, we will manipulate MMPS, plasmin or MT-5MMP in vivo by either pharmacological inhibition or siRNA knockdown and test for effect on recovery using structural and physiological indices of synaptic plasticity. These studies will better define matrix enzyme and substrate role in TBI-induced synaptic plasticity and provide new treatment strategies.

每年有数百万美国人是创伤性脑损伤（TBI）的受害者，使其成为严重的健康问题。 挑战. TBI通常涉及显著的轴突损伤，伴随神经元传入阻滞和突触损伤。 损失虽然大脑具有突触重组的固有能力，但这种可塑性在TBI后通常会失败， 导致严重的功能缺陷。我们最近研究了细胞外基质（ECM）的作用， TBI诱导的反应性突触发生期间的蛋白质。我们的研究结果表明，某些ECM蛋白和 它们的调节性基质金属蛋白酶（MMPs）强烈影响术后恢复的程度。 创伤性脑损伤在这些研究中，我们对比了ECM/MMP在恢复性适应性损伤（单侧）中的反应， 内皮层病变或DEC）和非恢复性适应不良损伤（液压冲击TBI +双侧 内嗅皮质病变或TBI +BEC）。两种明胶酶（MMPs 2、9）、溶基质素-1（MMP 3）和MMP 激活型纤溶酶的表达和功能都发生了变化，这与不同阶段的 反应性突触发生我们还发现异常的MMP激活与可塑性的失败有关 在TBI+BEC之后。当应用MMP抑制剂时，可塑性发生了积极或消极的改变 这取决于给药时间和损伤的复杂性。鉴于这些结果，我们现在确定具体的 基质酶/底物/效应物组介导突触前和突触后恢复的不同阶段， 以及损伤后新生突触的后续稳定。通过对比 这些基质蛋白在适应性UEC和适应不良TBI+BEC后，我们将确定个体是否 在突触发生的特定阶段的蛋白质功能障碍可以解释不同程度的恢复。 我们将测试MMP 3/agrin/FGF在突触的初始轴突发芽阶段的促进作用。 恢复，纤溶酶/磷酸蛋白聚糖/β-连环蛋白在随后的突触形成期，和MT-5 MMP/Ncadherin/ 突触稳定时的α-连环蛋白。在每种情况下，我们将记录蛋白质和mRNA表达， 分布在突触微环境和结合相互作用。最后，我们将操纵MMPS， 通过药理学抑制或siRNA敲低在体内检测纤溶酶或MT-5 MMP，并测试对 使用突触可塑性的结构和生理指标进行恢复。这些研究将更好地定义 基质酶和底物在TBI诱导的突触可塑性中的作用，并提供新的治疗策略。