Assessing the contribution of altered PI3K signaling to breathing abnormalities and sudden death in epilepsy

评估 PI3K 信号传导改变对癫痫呼吸异常和猝死的影响

• 批准号: 10458153
• 负责人: STEVEN ALLEN CRONE
• 金额: $ 19.88万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-15 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10458153
• 关键词: Acute; Affect; Amygdaloid structure; Animals; Apnea; Applications Grants; Area; Brain; Brain Stem; Brain region; Breathing; Cardiovascular system; Cells; Chronic; Cortical Malformation; Data; Defect; Development; Disease; Electroencephalography; Epilepsy; FRAP1 gene; Family; Functional disorder; Future; Germ-Line Mutation; Goals; Hippocampus (Brain); Human; Incidence; Individual; Knock-out; Knockout Mice; Knowledge; Laboratories; Lesion; Measures; Mediating; Medical; Methods; Modeling; Molecular; Monitor; Mus; Neurons; PTEN gene; Pathway interactions; Persons; Pharmacologic Substance; Phosphatidylinositols; Phosphotransferases; Play; Prosencephalon; Public Health; Publishing; Recurrence; Regulation; Research; Respiratory Diaphragm; Risk; Role; Seizures; Severities; Signal Pathway; Signal Transduction; Somatic Mutation; Sudden Death; Testing; Time; United States; Video Recording; Viral; Work; base; brain circuitry; dentate gyrus; designer receptors exclusively activated by designer drugs; diphtheria toxin receptor; excitatory neuron; high risk; human model; mortality; mouse model; novel; prevent; respiratory; sudden unexpected death in epilepsy; tool; treatment strategy

SUMMARY Sudden unexpected death in epilepsy (SUDEP) is the most frequent cause of mortality in epilepsy. There are no predictors and no cures. Previous research suggests that breathing abnormalities contribute to SUDEP, but the underlying molecular mechanisms or brain areas involved are not well understood. Moreover, there are no disease mechanism-based treatments. A better knowledge of the molecular, cellular and brain circuit defects that contribute to respiratory deficits in epilepsy and that could be pharmaceutically targeted to prevent or reduce SUDEP is therefore urgently needed. The proposed research will combine the synergistic expertise of two PIs in respiratory regulation (Crone) and epilepsy (Gross) to test the hypothesis that altered PI3K/mTOR signaling in the forebrain causes aberrant amygdala function, either directly through increased PI3K/mTOR activity in the amygdala or indirectly via altered brain circuits, which leads to breathing deficits that increase the risk for SUDEP. The hypothesis is supported by preliminary data showing that a mouse model with a deletion of PTEN, a negative regulator of the PI3K/mTOR pathway, in excitatory forebrain neurons has prominent breathing deficits, and that partial inhibition of PI3K activity reduces mortality in these mice. To further test this hypothesis, this grant proposal will take advantage of the two laboratories’ expertise in PI3K/mTOR signaling and their capability to perform continuous and synchronized diaphragm EMG/cortical EEG/video recording in mice, which provides a novel and powerful tool to simultaneously assess breathing and seizures for extended periods of time. Aim 1 will determine if breathing abnormalities in forebrain-specific Pten knockout mice are dependent on amygdala function and/or seizure activity. Breathing and EEG activity will be monitored over several weeks in presymptomatic and symptomatic mice to evaluate the timing and development of respiratory deficits and seizures. Viral approaches will be used to silence or ablate excitatory neurons in the amygdala to test if amygdala activity is necessary for breathing abnormalities and sudden death in this mouse model. Aim 2 will also use viral approaches and continuous monitoring of breathing and EEG to test if locally increasing PI3K/mTOR signaling in excitatiory neurons of the amygdala or the hippocampus is sufficient to cause respiratory deficits, seizures and/or SUDEP. This research will advance the knowledge about the functional consequences of defective PI3K/mTOR signaling in epilepsy, and will help reveal the brain circuits and molecular mechanisms involved in respiratory deficits causing SUDEP. Further, it will pave the way to develop novel treatment strategies for SUDEP targeting the underlying disease mechanisms.

概括 癫痫（SUDEP）突然意外死亡是癫痫死亡率最常见的原因。没有 预测因子，没有治疗方法。先前的研究表明，呼吸异常有助于Sudep，但 涉及的基本分子机制或大脑区域尚不清楚。而且，没有 基于疾病机制的治疗。更好地了解分子，细胞和脑电路缺陷 这有助于癫痫中的呼吸防御措施，并且可以将其靶向以防止或减少 因此，迫切需要Sudep。 拟议的研究将结合两个PI的协同专业知识在呼吸调节（CRONE）和 癫痫（总）测试了改变前脑中PI3K/mTOR信号的假设，导致异常 杏仁核功能，直接通过杏仁核中的PI3K/mTOR活性增加，或通过改变 大脑电路会导致呼吸不足，从而增加了SUDEP的风险。该假设得到 初步数据显示具有删除PTEN的鼠标模型，PTEN是PI3K/MTOR的负调节器 途径，在兴奋性前脑神经元中具有明显的呼吸缺陷，并且部分抑制PI3K 活性降低了这些小鼠的死亡率。为了进一步检验这一假设，该赠款提案将利用 这两个实验室在PI3K/MTOR信号传导方面的专业知识及其执行连续和的能力 小鼠中同步的隔膜EMG/皮质脑电图/视频录制，该录音提供了一种新颖而强大的工具 可以轻松评估较长时间的呼吸和癫痫发作。 AIM 1将确定是否呼吸 前脑特异性PTEN基因敲除小鼠的异常取决于杏仁核功能和/或癫痫发作 活动。呼吸和脑电图活动将在数周内监测为前提和症状 小鼠评估呼吸缺陷和癫痫发作的时间和发展。病毒方法将使用 在杏仁核中沉默或消融兴奋神经元，以测试杏仁核活性是否需要呼吸 这种小鼠模型中的异常和猝死。 AIM 2还将使用病毒方法并继续 监测呼吸和脑电图以测试是否在局部增加PI3K/mTOR信号传导 杏仁核或海马足以引起呼吸缺陷，癫痫发作和/或SUDEP。这项研究 将促进有关癫痫中PI3K/mTOR信号有缺陷的功能后果的知识， 并将有助于揭示呼吸道涉及的脑回路和分子机制定义引起SUDEP。 此外，它将为制定针对潜在疾病的SUDEP的新型治疗策略铺平道路 机制。