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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要：对于人类来说，多次早期接触需要麻醉的手术是一个重要的危险因素出现学习障碍和注意力障碍，并且持续时间更长（但不是更短）在临床前研究中，单次暴露期间的麻醉也与不良结果相关。显示全身麻醉持续时间与不良细胞和不良细胞之间的剂量反应关系证据表明，潜在的分子机制仍有待充分阐明。受损的海马脊髓发生和突触发生可能参与了以下机制：早期麻醉暴露会导致长期认知障碍，并且突触支架蛋白 PSD- 95 PDZ 结构域介导的蛋白质-蛋白质相互作用和突触活动涉及我们之前的研究。已经证明 PDZ 结构域介导的蛋白质相互作用被临床相关的蛋白质相互作用所破坏。最近，我们发现将出生后第 7 天（PND）的小鼠暴露于吸入麻醉剂的浓度。异氟烷抑制树突棘发育，改变突触可塑性，损害学习和记忆我们的结果表明，与 PSD-95 PDZ 结合域的麻醉破坏有关的功能。 PDZ 相互作用和 PDZ 结构域介导的突触功能的破坏可能在早期麻醉暴露产生长期认知障碍的发病机制。早期吸入麻醉会破坏 PDZ 结构域介导的神经发育相互作用导致 PSD-95-NMDAR 和相关突触复合物解偶联，从而产生抑制作用对树突棘、突触和乔木至关重要的几个重要的下游信号通路发育，从而产生长期的神经认知功能障碍。为了解决这一假设，我们的目标是。将确定连接麻醉诱导的 PSD-95 PDZ-解偶联的信号通路和机制 NMDAR-nNOS 突触复合物对神经回路至关重要的脊柱变化和突触成熟形成（目标 1）；我们将在体内验证受破坏的关键下游信号成分突触复合体 PSD-95-NMDAR-nNOS，并确定恢复它们是否可以充分防止麻醉对树突棘和突触发育、LTP 和记忆的有害影响（目标 2）；评估 PDZ 结构域破坏是否会延迟 NR2B 到 NR2A 的发育转换，影响生长树突和谷氨酸能关键可塑性相关蛋白的时空表达模式突触，并确定是否可以通过过度表达和敲低来防止乔木干扰方法（目标 3）。麻醉诱导 PSD-95 PDZ-NMDAR 和相关突触复合物解偶联以改变树突棘、突触和乔木发育导致长期认知障碍。