Semaphorin-dependent GABAergic synapse formation: A novel approach to increasing inhibition in the intact brain

信号蛋白依赖性 GABA 能突触形成：一种增强完整大脑抑制的新方法

• 批准号: 10372126
• 负责人: SUZANNE PARADIS
• 金额: $ 57.12万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10372126
• 关键词: Acute; Address; Adult; Benzodiazepines; Biological; Boston; Brain; CD100 antigen; Cell surface; Cells; Chronic; Collaborations; Data; Diazepam; Drug Targeting; Electric Stimulation; Electrophysiology (science); Epilepsy; Epileptogenesis; Event; Extracellular Domain; FDA approved; Frequencies; Future; Goals; Hippocampus (Brain); Human; In Vitro; Infusion procedures; Inhibitory Synapse; Injections; Integral Membrane Protein; Intervention; Intravenous infusion procedures; Medical emergency; Methods; Modeling; Morbidity - disease rate; Mus; Neonatal; Neurons; Patients; Pediatric Hospitals; Pentylenetetrazole; Persons; Pharmaceutical Preparations; Proteins; Refractory; Reporting; Risk; Rodent; Rodent Model; Route; Seizures; Semaphorins; Severities; Signal Pathway; Signal Transduction; Slice; Sodium Channel; Status Epilepticus; Synapses; Techniques; Tertiary Protein Structure; Testing; Therapeutic; Time; Viral; Virus; base; density; dentate gyrus; in vivo; induced pluripotent stem cell; mortality; mouse model; neural circuit; novel; novel strategies; novel therapeutic intervention; novel therapeutics; optimal treatments; plexin; pre-clinical; preclinical study; prenatal; prevent; receptor; receptor function; small molecule; success; synaptogenesis; trafficking; translatable strategy; translational potential; treatment strategy

We propose to harness the synaptogenic potential of Sema4D signaling to increase GABAergic synapse number, thus enhancing inhibition in neural circuits and suppressing seizures. This approach could be beneficial to preventing the establishment of epilepsy, halting its progression, or suppressing hyperexcitability during a seizure event. Previously our lab discovered that the extracellular domain of transmembrane protein Semaphorin 4D (Sema4D) drives inhibitory synapse formation on a remarkably fast time scale (i.e. minutes) in hippocampal neurons and slice cultured from the pre-natal and neonatal hippocampus. We also demonstrated that intra-hippocampal infusion of purified, Sema4D extracellular domain into the adult hippocampus rapidly promotes the formation of new GABAergic synapses. Further, we reported that Sema4D treatment protects against seizures induced by electrical stimulation of the dentate gyrus or by intravenous infusion of the proconvulsant drug pentylenetetrazol. Given the success of these studies, we undertook a new experimental direction to determine if Sema4D treatment has therapeutic potential for human epilepsies. The first aim of this proposal is to investigate Sema4D treatment as an acute, anti-seizure therapeutic in rodent models of status epilepticus (SE). SE is a medical emergency requiring immediate intervention in humans; approximately 30% of patients with SE are refractory to treatment with current medications including benzodiazepines. Preliminary data presented in this proposal shows that Sema4D treatment restored the efficacy of diazepam in a rodent model of refractory SE. This result is consistent with our hypothesis that Sema4D treatment acutely increases the number of GABAergic synapses in hippocampus, which maintains or re-establishes benzodiazepine sensitivity in the brain. The second aim of our proposal is to determine the effect of chronic exposure of Sema4D (via viral delivery to the CNS) on inhibitory synapse formation and ultimately, seizure frequency and severity in rodent models of chronic epilepsy. As a first step towards this goal we will explore the efficacy and time-course of alternative methods of administering Sema4D (e.g. intracerebral injection of virus encoding Sema4D) to mice. In the third aim, we will begin to address the translatability of our findings with Sema4D in rodents by asking if Sema4D promotes inhibitory synapse formation and network activity in cultures of human neurons.

我们建议利用 Sema4D 信号传导的突触潜力来增加 GABA能突触数量，从而增强神经回路的抑制并抑制 癫痫发作。这种方法可能有助于预防癫痫病的发生、制止 其进展，或抑制癫痫发作期间的过度兴奋。 此前我们实验室发现跨膜蛋白的胞外结构域 Semaphorin 4D (Sema4D) 以极快的时间尺度驱动抑制性突触形成 （即分钟）在海马神经元和从产前和新生儿培养的切片中 海马体。我们还证明海马内输注纯化的 Sema4D 细胞外结构域进入成人海马迅速促进新细胞的形成 GABA能突触。此外，我们报告 Sema4D 治疗可预防癫痫发作 通过电刺激齿状回或静脉注射 促惊厥药物戊四氮。 鉴于这些研究的成功，我们采取了新的实验方向 确定 Sema4D 治疗是否具有治疗人类癫痫的潜力。第一个目标是 该提案旨在研究 Sema4D 治疗作为啮齿动物的急性抗癫痫治疗方法 癫痫持续状态（SE）模型。 SE 是一种医疗紧急情况，需要立即干预 在人类中；大约 30% 的 SE 患者对目前的治疗无效 药物，包括苯二氮卓类药物。该提案中提供的初步数据表明 Sema4D 治疗恢复了地西泮在难治性 SE 啮齿动物模型中的疗效。这 结果与我们的假设一致，即 Sema4D 治疗急剧增加了 海马体中的 GABA 突触，维持或重建苯二氮卓类药物 大脑的敏感性。 我们提案的第二个目标是确定长期接触的影响 Sema4D（通过病毒传递至中枢神经系统）对抑制性突触形成和最终癫痫发作的影响 慢性癫痫啮齿动物模型的频率和严重程度。作为实现这一目标的第一步，我们 将探索施用 Sema4D 的替代方法的功效和时间进程（例如 向小鼠脑内注射编码 Sema4D 的病毒。在第三个目标中，我们将开始 通过询问 Sema4D 是否可以解决我们在啮齿动物中使用 Sema4D 的研究结果的可转化性 促进人类神经元培养物中抑制性突触的形成和网络活动。