TRPV1-mediated induction of a protective heat shock response after stroke

TRPV1 介导的中风后保护性热休克反应的诱导

基本信息

批准号：
8919475
负责人：
Sean P Marrelli
金额：
$ 19.81万
依托单位：
BAYLOR COLLEGE OF MEDICINE
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：
2014-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8919475
关键词：
Affect Agonist Animal Tarsus Animals Apoptosis Astrocytes Body Temperature Brain Brain Part Ca(2+)-Calmodulin Dependent Protein Kinase Cations Cause of Death Cell physiology Cells Chemosensitization Cities Conscious Disease Distal Dose Fiber HSF1 Health Heat Shock Protein 27 Heat shock proteins Heat-Shock Response Heating Histology Hour Immunofluorescence Immunologic Infarction Injury Ions Ischemic Stroke Knockout Mice Lipids Mediating Methods Modeling Mus Nerve Fibers Nervous System Physiology Neurodegenerative Disorders Neurons Peripheral Nerves Play Prevention Reaction Time Recovery Recovery of Function Reperfusion Therapy Research Design Role Sensory Specificity Stress Stroke System Testing Therapeutic Time Transcriptional Activation United States Vanilloid artery occlusion base behavior test calmodulin-dependent protein kinase II cell type cerebral artery disability improved in vivo natural hypothermia neuroprotection novel protein expression receptor response treatment strategy

项目摘要

DESCRIPTION (provided by applicant): Ischemic stroke is among the leading causes of death and disability in the United States; however, current treatment options are very limited. We recently demonstrated significant neuroprotection following stroke by promoting therapeutic hypothermia (Tc=33� C) through selective pharmacological agonism of TRPV1 channels in conscious mice. We extend these findings in the present proposal by demonstrating that a significant portion of the neuroprotection derived from TRPV1 agonism is actually independent of the hypothermic effect. While seeking the mechanism of this novel hypothermia- independent effect, we discovered that TRPV1 agonists promote a protective heat shock response (HSR) in the brain. TRPV1 is a Ca2+-permeable non-selective cation channel found within heat- sensitive sensory fibers of the thermoregulatory system as well as multiple other cell types in the brain. The HSR is an endogenous cellular response that involves rapid transcriptional activation of heat shock proteins (Hsps) which contribute to the prevention or reversal of cellular damage. This cytoprotective mechanism contributes to the body's survival response to a variety of insults and injuries, including stroke. In the brain, Hsp27 and Hsp70 appear to play critical roles in neurorecovery from stroke. The overall aim of this project is to demonstrate TRPV1 channel agonism as an effective therapeutic strategy to promote HSR activation and sustained neuroprotection following ischemic stroke. Specifically, we will 1) determine the mechanism and cell specificity of TRPV1-mediated HSR induction in the uninjured and stroke brain and 2) determine if TRPV1-mediated HSR induction provides sustained neuroprotection following stroke. Initial studies will be performed with cultured brain astrocytes and neurons to test proposed mechanisms of TRPV1-mediated induction of Hsp27 and Hsp70, using pharmacological modulators and cultures established from mechanism-specific knockout (KO) mice. These studies will be followed by whole animal studies to determine the in vivo dose- response, time course, and cell specificity of HSR induction by TRPV1 agonism in the uninjured brain and the brain following focal ischemic stroke in wild type and mechanism-specific KO mice. Lastly, studies will be performed with stroke mice to determine if TRPV1-mediated HSR induction provides sustained neuroprotection through 28 days of reperfusion. Neuroprotection will be evaluated by histological/immunofluorescence methods to determine cell specific survival, BBB integrity, and apoptosis and by behavior testing to demonstrate ultimate functional recovery. The specific roles of Hsp27 and Hsp70 in neuroprotection will be determined with respective KO mice. It is expected that these studies will demonstrate novel neuroprotective mechanisms of TRPV1 agonism in the brain and lay the groundwork for improved treatment strategies for stroke and other neurodegenerative diseases.

描述（适用提供）：缺血性中风是美国死亡和残疾的主要原因之一；但是，当前的治疗选择非常有限。我们最近通过在有意识的小鼠中TRPV1通道的选择性药物激动剂来促进治疗性低温（TC =33。C），通过促进治疗性低温（TC =33。C）表现出明显的神经保护作用。我们通过证明从TRPV1激动剂衍生的神经保护的很大一部分实际上与低温作用无关，我们将这些发现扩展到本提案中。在寻求这种新型低温独立效应的机制时，我们发现TRPV1激动剂促进了大脑中受保护的热休克反应（HSR）。 TRPV1是在热调节系统的热敏感感觉纤维中以及大脑中其他多种细胞类型中发现的CA2+ - 可渗透的非选择性阳离子通道。 HSR是一种内源性细胞反应，涉及热激蛋白（HSP）的快速转录激活，有助于预防或逆转细胞损伤。这种细胞保护机制有助于人体对包括中风在内的各种伤害和伤害的生存反应。在大脑中，HSP27和HSP70似乎在中风的神经记录中起关键作用。该项目的总体目的是证明TRPV1通道激动剂是一种有效的理论策略，可在缺血性中风后促进HSR激活和持续的神经保护作用。具体而言，我们将1）确定在未受伤和中风大脑中TRPV1介导的HSR诱导的机理和细胞特异性； 2）确定TRPV1介导的HSR诱导是否在中风后提供持续的神经保护作用。最初的研究将使用培养的脑星形胶质细胞和神经元进行测试，以测试使用由机理特异性敲除（KO）小鼠建立的药物调节剂和培养物的TRPV1介导的HSP27和HSP70的诱导机制。这些研究将在整个动物研究之后进行，以确定TRPV1激动剂在野生型和机理特异性KO小鼠中局灶性缺血性中风后，通过TRPV1激动剂在未受伤的大脑和大脑中通过TRPV1激动剂对HSR诱导的细胞特异性进行了整体研究。最后，将使用中风小鼠进行研究，以确定TRPV1介导的HSR诱导是否在28天的再灌注过程中提供持续的神经保护作用。神经保护将通过组织学/免疫荧光方法评估，以确定细胞特异性生存，BBB完整性和凋亡以及行为测试以证明最终的功能恢复。 Hsp27和Hsp70在神经保护中的特定作用将由相对KO小鼠确定。预计这些研究将证明大脑中TRPV1激动剂的新型神经保护机制，并为改善中风和其他神经退行性疾病的治疗策略奠定了基础。