Effects of Semaphorin 3A on Stroke Recovery

Semaphorin 3A 对中风恢复的影响

基本信息

批准号：
8470260
负责人：
KLAUS VAN LEYEN
金额：
$ 33.01万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-01 至 2015-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8470260
关键词：
12-HETE Address Affect Antibodies Arachidonate 12-Lipoxygenase Arachidonate 15-Lipoxygenase Axon Biological Assay Blood Vessels Brain Brain Injuries Brain region Cell Culture Techniques Cell Line Cells Cerebrum Confocal Microscopy Corpus striatum structure Data Endothelial Cells Environment Goals Growth Cones Healed Human Immunohistochemistry In Vitro Infarction Injury Ipsilateral Ischemia Lead Lipoxygenase Maps Mediating Mediator of activation protein Methods Middle Cerebral Artery Occlusion Mitogen-Activated Protein Kinases Modeling Molecular Mus Neurofilament Proteins Neurons Neuropilin-1 Outcome Pathway interactions Process Proteins Recombinants Recovery Recovery of Function Role Semaphorin-3A Semaphorins Side Signal Pathway Signal Transduction Site Stroke Testing Therapeutic Time Tissue Sample Tube Vascularization Western Blotting adult neurogenesis angiogenesis axon growth axon guidance axonal pathfinding cell motility functional restoration healing improved in vivo inhibitor/antagonist injured matrigel metallothionein III mouse model neovascularization neurogenesis neuron development neuronal growth novel strategies post stroke prevent receptor relating to nervous system repaired spatiotemporal stroke recovery synaptogenesis

项目摘要

DESCRIPTION (provided by applicant): After a stroke occurs, the brain up-regulates several repair pathways in an attempt to heal itself. One of the reasons for limited efficacy of this repair process lies in the presence of growth inhibitory factors in the injured region of the brain. Here, we propose to investigate the influence of signaling via the axon guidance molecule semaphorin 3A (Sema3A) on the recovery process after experimental stroke. Our hypothesis states that, analogous to its function in the developing brain, Sema3A acts as a repellent for growing axons and endothelial cells during adult neurogenesis and revascularization, and that this activity will be detrimental for the recovery process. Our pilot data suggest that i) Sema3A and its receptor neuropilin-1 (NRP-1), are up- regulated in the ischemic brain; ii) recombinant Sema3A leads to axon retraction in cultured cortical neurons, and inhibits tube formation in a brain endothelial cell line; and iii) Sema3A signaling can be disrupted by inhibition of 12/15-LOX. To expand these findings, we propose the following specific aims. In Aim 1, we use cultured primary neurons and a brain microvascular endothelial cell line to study the signaling pathways through which Sema3A operates. Both axonal pathfinding in neurons and development of new blood vessels following experimental stroke may be crucial for stroke recovery, and both are impacted by Sema3A. We will focus on signaling through the MAP kinase proteins, and on metabolites of 12/15-lipoxygenase, which have been shown to mediate the repulsive actions of Sema3A. In Aim 2, we study the expression of Sema3A and its receptor Neuropilin 1 (NRP1), in a mouse model of middle cerebral artery occlusion (MCAO). We will investigate differential effects of sema expression on neurogenesis-related axonal connectivity and the formation of brain microvessels, and correlate levels of Sema3A with functional recovery. In Aim 3, we inhibit axonal pathfinding of newly born neurons by injecting soluble semaphorin on the ipsilateral side of the brain subjected to MCAO. Alternatively, we disrupt semaphorin signaling by injecting an inhibitory peptoid, and by inhibiting the downstream mediator 12-lipoxygenase. Endogenous repair processes activated after stroke can potentially restore functionality to the damaged brain. Can manipulating the semaphorin pathway lead to more efficient integration of neurons and an improved revascularization? This application is relevant to PA-08-099 "Mechanisms of functional recovery after stroke".

描述（由申请人提供）：中风发生后，大脑会上调多种修复途径以尝试自我治愈。这种修复过程功效有限的原因之一在于大脑受损区域中存在生长抑制因子。在这里，我们建议研究轴突引导分子信号蛋白 3A (Sema3A) 信号传导对实验性中风后恢复过程的影响。我们的假设表明，类似于其在发育中大脑中的功能，Sema3A 在成人神经发生和血运重建过程中充当轴突和内皮细胞生长的排斥剂，并且这种活性将不利于恢复过程。我们的试验数据表明 i) Sema3A 及其受体神经毡蛋白-1 (NRP-1) 在缺血性大脑中表达上调； ii) 重组 Sema3A 导致培养的皮质神经元中的轴突回缩，并抑制脑内皮细胞系中的管形成； iii) Sema3A 信号传导可通过抑制 12/15-LOX 来破坏。为了扩展这些发现，我们提出以下具体目标。在目标 1 中，我们使用培养的原代神经元和脑微血管内皮细胞系来研究 Sema3A 运作的信号通路。神经元的轴突寻路和实验性中风后新血管的发育可能对中风恢复至关重要，两者都受到 Sema3A 的影响。我们将重点关注通过 MAP 激酶蛋白的信号传导以及 12/15-脂氧合酶的代谢物，这些代谢物已被证明可以介导 Sema3A 的排斥作用。在目标 2 中，我们研究了大脑中动脉闭塞 (MCAO) 小鼠模型中 Sema3A 及其受体 Neuropilin 1 (NRP1) 的表达。我们将研究 sema 表达对神经发生相关的轴突连接和脑微血管形成的差异影响，并将 Sema3A 的水平与功能恢复相关联。在目标 3 中，我们通过在接受 MCAO 的大脑同侧注射可溶性信号蛋白来抑制新生神经元的轴突寻路。或者，我们通过注射抑制性肽并抑制下游介质 12-脂氧合酶来破坏信号蛋白信号传导。中风后激活的内源性修复过程有可能恢复受损大脑的功能。操纵信号蛋白通路能否导致神经元更有效的整合并改善血运重建？本申请与 PA-08-099“中风后功能恢复机制”相关。