Effects of Semaphorin 3A on Stroke Recovery

Semaphorin 3A 对中风恢复的影响

• 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
• 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

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，大脑上调了几种修复途径，以尝试自我修复。该修复过程有限疗效的原因之一是在大脑受伤区域存在生长抑制因素。在这里，我们建议通过轴突引导分子信号素3A（SEMA3A）对信号传导的影响对实验中风后的恢复过程。我们的假设指出，类似于其在发育中的大脑中的功能，Sema3a在成人神经发生和血运重建过程中起到了驱虫剂的生长和内皮细胞的驱虫剂，并且这种活性将对恢复过程有害。我们的试点数据表明，在缺血性大脑中，i）i）sema3a及其受体神经蛋白-1（NRP-1）受到调节； ii）重组SEMA3A导致培养的皮质神经元的轴突缩回，并抑制脑内皮细胞系中的管形成； iii）SEMA3A信号传导可能会因抑制12/15-lox而受到破坏。为了扩展这些发现，我们提出以下特定目标。在AIM 1中，我们使用培养的原发性神经元和脑微血管内皮细胞系来研究SEMA3A操作的信号通路。实验中风后神经元中的轴突探路和新血管的发展对于中风恢复至关重要，并且两者都受SEMA3A的影响。我们将专注于通过MAP激酶蛋白的信号传导，以及12/15-脂氧酶的代谢产物，这些代谢酶已被证明可以介导SEMA3A的排斥作用。在AIM 2中，我们研究了SEMA3A及其受体神经蛋白1（NRP1）的表达，在脑动脉闭塞的小鼠模型（MCAO）中。我们将研究SEMA表达对与神经发生相关的轴突连通性和脑微血管的形成以及SEMA3A水平与功能恢复相关的差异影响。在AIM 3中，我们通过在受MCAO受到的大脑的同侧注射可溶性词来抑制新生神经元的轴突探路。或者，我们通过注入抑制性肽并抑制下游介体12-脂氧酶来破坏词素信号传导。中风后激活的内源修复过程可能会恢复受损大脑的功能。操纵信号素途径是否会导致神经元的更有效整合和改善的血运重建？该应用与PA-08-099“中风后功能恢复机制”有关。