TRPM2 channels and synaptic dysfunction following ischemic injury in the developing brain.

发育中大脑缺血损伤后的 TRPM2 通道和突触功能障碍。

基本信息

批准号：
9386009
负责人：
Robert M Dietz
金额：
$ 19.33万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-15 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9386009
关键词：
Acute Adolescent Adult Behavior Biological Preservation Brain Brain Injuries Calcineurin Cell Death Cell model Cerebral Ischemia Child Clinical Research Cognitive deficits Communication Data Development Electrophysiology (science)Exhibits Face Functional disorder Genetic Heart Arrest Hippocampus (Brain)Impairment Infant Injury Innovative Therapy Intervention Ion Channel Ischemia Lead Learning Long-Term Potentiation Measures Memory Memory impairment Mentors Modeling Molecular Mus Neurologic Neuronal Dysfunction Neurons Oxidative Stress Pathologic Peptides Pharmacology Phenotype Physiological Physiology Play Puberty Recovery Reperfusion Injury Research Research Proposals Role Signal Transduction Stimulus Stress Subfamily lentivirinae Survivors Synapses Synaptic plasticity Techniques Testing Therapeutic Time Training Transfection Translating Work behavior test career design developmental plasticity experience experimental study fitness functional disability functional outcomes improved in vivo inhibitor/antagonist innovation juvenile animal knock-down mouse model neuron loss neuroprotection neurotoxicity new therapeutic target novel novel therapeutics preclinical study prepuberty prevent protein expression protein function receptor skills small hairpin RNA synaptic function young adult

项目摘要

Project Summary Global cerebral ischemia caused by cardiac arrest results in many neurological sequelae, including deficits in learning and memory. These deficits are as evident in children as they are in adults. The resulting neurological sequelae from cardiac arrest (CA) in children likely arise from both neuronal death and altered physiology in surviving neurons. TRPM2 channels are non-selective ion channels that are activated by hyperoxidative stress and are compelling targets in preventing neurotoxicity and cellular dysfunction. Our lab has recently designed a novel inhibitor of TRPM2 channels, known as tatM2NX, to better understand the role of TRPM2 in neuronal death and dysfunction. A useful measure to assess neuronal dysfunction is to investigate the level of synaptic function. The ability for neurons to undergo synaptic plasticity (long-term potentiation; LTP) in the hippocampus is recognized as an innate measure of function and is a widely accepted cellular model for learning and memory. This proposal makes use of a novel cardiac arrest model in juvenile mice (p21-25) to investigate the hypothesis that activation of TRPM2 channels contributes to impairment of synaptic function and cognitive deficits following global cerebral ischemia. We have found that inhibiting TRPM2 soon after juvenile CA leads to preservation of synaptic function, despite no significant change in neuronal death. We will further test the hypothesis by inhibiting TRPM2 at delayed time points (7-14 days after PCA). Inhibition of TRPM2 will be done with pharmacology (in vivo tatM2NX) or genetic modulation (TRPM2-/-, lentiviral shRNA TRPM2 knockdown) and function will be assessed by electrophysiology and behavior. Preliminary data suggest that delayed inhibition of TRPM2 reverses synaptic impairments after CA. We will use signal transduction techniques to identify the mechanism for synaptic impairment after ischemia-induced TRPM2 activation. We will focus on the hypothesis that activation of TRPM2 signals calcineurin, leading to decreased synaptic function. Finally, we have found that while ischemia in young animals results in impairment of synaptic function up to 14 days after CA, there is remarkable endogenous recovery to control levels. The final aim of the project will investigate the role of developmental changes in TRPM2 expression in neurons through puberty into adulthood that may account for endogenous recovery of impaired synaptic function. Overall, this project has high translational potential through the opportunity of redefining therapeutic windows after global cerebral ischemia in children. Experiments outlined in this proposal will provide important training for an independent research career. In this proposal, I will learn hippocampal lentivirus shRNA transfection, behavior testing, and signal transduction techniques to assess protein expression and function. The mentor team assembled has experience and expertise to assure completion of this project. Upon completion of this proposal, I will combine these skills with electrophysiology techniques that I am already familiar with and apply for an R01 to further characterize TRPM2 activity in the maturing juvenile mouse after cardiac arrest. The impact of this work will be in establishing a novel therapeutic strategy to improve neurological consequences of ischemia in the young brain.

项目摘要由心脏骤停引起的全球脑缺血导致许多神经系统后遗症，包括缺陷学习和记忆。这些缺陷在儿童中与成年人一样明显。由此产生的神经系统儿童心脏骤停（CA）的后遗症可能是由神经元死亡和生理改变引起的幸存的神经元。 TRPM2通道是非选择性离子通道，被高氧化应激激活并且是预防神经毒性和细胞功能障碍的引人注目的目标。我们的实验室最近设计了 TRPM2通道的新型抑制剂（称为TATM2NX）可以更好地了解TRPM2在神经元中的作用死亡和功能障碍。评估神经元功能障碍的有用措施是研究突触的水平功能。神经元在海马中经历突触可塑性（长期增强； LTP）的能力被认为是一种与生俱来的功能衡量，是一个广泛接受的学习和记忆。该提案利用了少年小鼠（P21-25）中新型的心脏骤停模型来研究假设TRPM2通道的激活有助于突触功能和认知的损害全球脑缺血后的缺陷。我们发现少年CA引导后不久抑制TRPM2 尽管神经元死亡没有显着变化，但仍保存突触功能。我们将进一步测试通过在延迟时间点（PCA后7-14天）抑制TRPM2的假设。将抑制TRPM2 使用药理学（体内TATM2NX）或遗传调制（TRPM2 - / - ，慢病毒SHRNA TRPM2敲低）功能将通过电生理学和行为评估。初步数据表明延迟 TRPM2的抑制会反转大约之后的突触障碍。我们将使用信号转导技术确定缺血诱导的TRPM2激活后突触损伤的机制。我们将专注于假设TRPM2信号钙调神经蛋白酶的激活导致突触功能降低。最后，我们已经发现，虽然年轻动物缺血会导致突触功能损害长达14天 CA，对控制水平有明显的内源性恢复。该项目的最终目标将调查通过青春期到成年的神经元中TRPM2表达中发育变化的作用考虑突触功能受损的内源性恢复。总体而言，该项目具有很高的翻译在全球脑缺血儿童之后，可以通过重新定义治疗窗口的机会来潜力。该提案中概述的实验将为独立研究职业提供重要的培训。在这个提案，我将学习海马慢病毒shRNA转染，行为测试和信号转导评估蛋白质表达和功能的技术。聚集的导师团队有经验，确保完成该项目的专业知识。该提案完成后，我将将这些技能与我已经熟悉并申请R01的电生理技术进一步表征心脏骤停后成熟的幼体小鼠的TRPM2活性。这项工作的影响将是建立一种新型的治疗策略，以改善年轻大脑缺血的神经系统后果。