Mechanistic Actions of PDZ Domain Mediated Protein Interactions on Neural Development and Anesthetic-Mediated Neurotoxicity

PDZ 结构域介导的蛋白质相互作用对神经发育和麻醉介导的神经毒性的机制作用

• 批准号: 10390873
• 负责人: Roger A Johns
• 金额: $ 0.5万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10390873
• 关键词: Address; Affect; Anesthesia procedures; Anesthetics; Attention; Binding; Complex; Critical Pathways; Dendrites; Dendritic Spines; Development; Dose; Exposure to; Functional disorder; General Anesthesia; Glutamates; Goals; Hippocampus (Brain); Human; Impaired cognition; Impairment; Inhalation Anesthesia; Inhalation Anesthetics; Investigation; Isoflurane; Lead; Learning; Learning Disabilities; Learning Disorders; Link; Mediating; Memory; Molecular; Mus; Neurocognitive; Pathogenesis; Pattern; Play; Procedures; Proteins; Risk Factors; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Synapses; Synaptic plasticity; Vertebral column; adverse outcome; clinically relevant; functional outcomes; in vivo; knock-down; neural circuit; neurodevelopment; neurotoxicity; neurotransmission; overexpression; postnatal; preclinical study; prevent; protein protein interaction; response; synaptic function; synaptogenesis

Project Summary: In humans, multiple early exposures to procedures requiring anesthesia is a significant risk factor for development of learning disabilities and disorders of attention and longer, but not shorter, durations of anesthesia during a single exposure are also associated with adverse outcomes. While preclinical studies show a dose–response relationship between the duration of general anesthesia and adverse cellular and functional outcomes the underlying molecular mechanisms remain to be fully elucidated. Evidence indicates that impaired hippocampal spinogenesis and synaptogenesis may be involved in the mechanisms by which early anesthetic exposure produces long-term cognitive impairment, and that synaptic scaffolding protein PSD- 95 PDZ domain-mediated protein-protein interactions and synaptic activities are involved. Our previous studies have demonstrated that PDZ domain-mediated protein interactions are disrupted by clinically relevant concentrations of inhaled anesthetics. Recently, we showed that exposing postnatal day (PND) 7 mice to isoflurane inhibits dendritic spine development, alters synaptic plasticity, and impairs learning and memory function in relation to the anesthetic disruption of PSD-95 PDZ binding domains. Our results showed that the disruption of PDZ interactions and PDZ domain-mediated synaptic function may play important roles in the pathogenesis of early anesthetic exposure-produced long-term cognitive impairment. We hypothesize that early exposure to inhalational anesthesia alters neural development by disrupting PDZ-domain mediated interactions causing uncoupling of PSD-95-NMDAR and associated synaptic complexes resulting in inhibition of several prominent downstream signaling pathways critical to dendritic spine, synapse, and arbor development, thereby producing long-term neurocognitive dysfunction. To address this hypothesis, our aims will identify the signaling pathways and mechanisms that link anesthesia induced uncoupling of PSD-95 PDZ- NMDAR-nNOS synaptic complex to changes in spine and synapse maturation critical to neural circuit formation (Aim 1); we will validate, in vivo, key downstream signaling components effected by disruption of the synaptic complex, PSD-95-NMDAR-nNOS, and determine if restoring them can sufficiently prevent the deleterious effects of anesthesia on dendritic spine and synaptic development, LTP, and memory (Aim 2); assess whether PDZ domain disruption delays the NR2B to NR2A developmental switch, affects growing dendrites and the spatial and temporal expression patterns of critical plasticity related proteins in glutamatergic synapses, and determine if arbor disturbances can be prevented using over-expression and knock-down approaches (Aim 3). The proposed studies will identify the signaling pathways and mechanisms linking anesthesia induced uncoupling of PSD-95 PDZ-NMDAR and associated synaptic complexes to changes in dendritic spine, synapse, and arbor development that lead to long-term cognitive impairment.

项目摘要： 在人类中，需要对需要麻醉的程序进行多次早期暴露是重要的危险因素 学习障碍和关注障碍的发展，持续时间更长，但较短的持续时间 一次暴露期间的麻醉也与不良结果有关。而临床前研究 在全身麻醉和不良细胞的持续时间之间显示出剂量反应关系 功能结果尚待完全阐​​明基本分子机制。证据表明 这种障碍的海马旋转发生和突触发生可能与该机制有关 早期麻醉暴露会产生长期的认知障碍，并且突触脚手架蛋白PSD- 涉及95个PDZ结构域介导的蛋白质 - 蛋白质相互作用和突触活动。我们以前的研究 已经证明PDZ结构域介导的蛋白质相互作用被临床相关的破坏 遗传麻醉剂的浓度。最近，我们证明了暴露于产后日（PND）7只小鼠 异氟烷抑制树突状脊柱的发展，改变突触可塑性并损害学习和记忆力 与PSD-95 PDZ结合域的麻醉破坏有关的功能。我们的结果表明 PDZ相互作用和PDZ域介导的突触功能的破坏可能在 早期麻醉暴露产生的长期认知障碍的发病机理。我们假设这一点 吸入麻醉的早期暴露通过破坏PDZ域介导的神经发育 相互作用导致PSD-95-NMDAR和相关的突触复合物的解偶联，导致抑制作用 在树突状脊柱，突触和乔木至关重要的几个突出的下游信号通路中 开发，从而产生长期神经认知功能障碍。为了解决这一假设，我们的目标 将确定连接麻醉诱导PSD-95 PDZ-解偶联的信号通路和机制 NMDAR-NNOS合成复合物，脊柱变化和突触成熟至关重要的神经回路 编队（目标1）；我们将在体内验证受破坏影响的下游信号传导组件 突触复合物，PSD-95-NMDAR-NNOS，并确定是否恢复它们是否可以充分防止 麻醉对树突状脊柱和突触发育，LTP和记忆的有害影响（AIM 2）； 评估PDZ域的破坏是否会延迟NR2B为NR2A开发开关，影响增长 谷氨酸能与临界可塑性相关蛋白的树突和临时表达模式 突触，并确定是否可以使用过表达和击倒来防止植物灾害 方法（目标3）。提出的研究将确定连接的信号通路和机制 麻醉诱导PSD-95 PDZ-NMDAR和相关的突触复合物的解偶联对变化的变化 树突状脊柱，突触和乔木发育，导致长期认知障碍。