Heat shock proteins and neuroprotection in cerebral ischemia

热休克蛋白与脑缺血的神经保护

• 批准号: 8731306
• 负责人: Jun Chen
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8731306
• 关键词: Actins; Adult; Apoptotic; Blood - brain barrier anatomy; Brain; Brain Injuries; Cells; Cellular Structures; Central Nervous System Diseases; Cerebral Ischemia; Cerebrum; Clinical; Cytoskeletal Modeling; Cytoskeleton; Data; Development; Disabled Persons; Disease; Edema; Endothelial Cells; Endothelium; Event; Exhibits; Extravasation; Future; Gelatinase A; Gene Targeting; Genes; Glucose; Heat Shock Protein 27; Heat shock proteins; Immune; Impairment; In Vitro; Infarction; Infiltration; Inflammation; Inflammation Mediators; Inflammatory; Ischemia; Ischemic Stroke; Lentivirus Vector; Life; Liquid substance; MMP2 gene; Mediating; Medical; Middle Cerebral Artery Occlusion; Military Personnel; Modeling; Molecular Chaperones; Mus; NF-kappa B; Nervous System Physiology; Neurologic; Neurological outcome; Outcome; Oxygen; Pathogenesis; Patients; Permeability; Plasma Proteins; Production; Protective Agents; Protein Family; Proteins; Quality of life; Reperfusion Injury; Reperfusion Therapy; Rodent; Role; Signaling Molecule; Stroke; Survivors; Testing; Therapeutic; Therapeutic Agents; Thrombolytic Therapy; Time; Transfection; Transgenic Mice; Transgenic Organisms; United States; Veterans; abstracting; aged; base; cell type; depolymerization; deprivation; disability; improved; in vivo; innovation; intravenous administration; intravenous injection; member; nervous system disorder; neuroprotection; novel; novel therapeutics; overexpression; polymerization; post stroke; prevent; protective effect; public health relevance; small molecule; stroke therapy; treatment strategy; vpr Genes; white matter injury; young adult

DESCRIPTION (provided by applicant): Abstract Stroke is a major medical concern for United States military veterans. Disruption of the blood-brain barrier (BBB) is a catastrophic event in the pathogenesis of ischemic/reperfusion (I/R) brain injury. Our recent studies suggested that structural alterations in brain endothelial cells (EC), including abnormal actin polymerization and the resulting redistribution of junctional proteins, is a novel mechanism responsible for early BBB leakage after I/R (30 min-3h); while matrix metalloproteinase (MMP) 2/9 activation, a predominant mechanism thought to contribute to post-stroke BBB disruption, contribute to the BBB leakage to larger molecules (>40kDa) in a relatively delayed manner. Therefore, restoring EC structure/function may offer an innovative therapeutic strategy for early BBB protection against I/R, while blocking MMP2/9 may provide a relatively delayed protection to BBB. Heat shock protein 27 (HSP27), a member of the small heat shock protein family, confers neuroprotection in several models of CNS diseases, including I/R brain injury. In addition to its well-known protein chaperone and anti-apoptotic functions, HSP27 may act as a potent actin depolymerization factor in certain cell types such as EC, thus potentially inhibiting actin polymerization-mediated BBB disruption. Further, HSP27 may inhibit the activation of NF-kappaB, a central signaling molecule for the production of MMP2/9 and pro-inflammatory mediators. We recently observed that HSP27 is transiently upregulated in brain EC after I/R. However, the precise role of HSP27 in the functional integrity of EC following I/R and the underlying mechanism remain unknown. Using transgenic mice overexpressing HSP27 and the lentiviral gene-transfection approach, we have obtained novel pilot data showing that HSP27 overexpression protects the endothelium from I/R-induced hyperpermeability in vitro and in vivo; that HSP27 inhibited oxygen glucose deprivation-induced actin polymerization and redistribution of junctional proteins in EC; and that intravenous administration of HSP27 containing a cell permeable transduction domain (TAT-HSP27) enabled rapid delivery of the protein into brain micro-vasculatures, reduced BBB damage and inhibited MMP2/9 activity after I/R. This proposal will further explore the BBB protective effect of HSP27 on I/R brain injury and elucidate the underlying mechanisms. The central hypothesis to be tested is that HSP27 protects BBB against I/R injury by stabilizing EC cytoskeletal organization in microvasculature early after I/R and inhibiting the production of MMP2/9 as well as pro-inflammatory proteins. The following specific aims are proposed: Aim 1: To determine whether endothelial targeted overexpression of HSP27 is sufficient to provide early protection on BBB integrity and to confer long term protection against cerebral I/R. Aim 2: Test the hypothesis that HSP27 protects endothelial integrity following I/R by dualistic mechanisms: stabilizing the actin cytoskeleton and inhibiting NFkB-dependent MMP2/9 production and inflammation. Aim 3: Test the hypothesis that post-stroke delivery of TAT-HSP27 to EC protects against BBB damage and improves outcomes in both young adult and aged mice. The proposed study attempts to develop HSP27 into a novel, clinically feasible therapeutic strategy to ameliorate post-stroke BBB damage, brake down the progression of brain damage, and improve long-term neurological functions in stroke victims. The successful completion of this proposed study will help improve the quality of life for veterans suffering from stroke.

描述（由申请人提供）： 抽象中风是美国退伍军人的主要医学问题。血脑屏障（BBB）的破坏是缺血/再灌注（I/R）脑损伤发病机理中的灾难性事件。我们最近的研究表明，脑内皮细胞（EC）的结构改变，包括异常的肌动蛋白聚合和结合蛋白的重新分布，是一种新型机制，负责I/R（30分钟-3H）后早期BBB泄漏。虽然基质金属蛋白酶（MMP）2/9激活，但一种被认为会导致冲程后BBB破坏的主要机制，以相对延迟的方式导致BBB泄漏到更大的分子（> 40KDA）。因此，恢复EC结构/功能可能会为I/R的早期BBB保护提供创新的治疗策略，而阻止MMP2/9可能会为BBB提供相对延迟的保护。 热休克蛋白27（HSP27）是小型热休克蛋白家族的成员，在包括I/R脑损伤在内的几种CNS疾病模型中赋予了神经保护作用。除了其众所周知的蛋白质伴侣和抗凋亡功能外，HSP27还可以在某些细胞类型（例如EC）中充当有效的肌动蛋白解聚因子，从而可能抑制肌动蛋白聚合介导的BBB破坏。此外，HSP27可能会抑制NF-kappab的激活，NF-kappab是一种用于产生MMP2/9和促炎性介体的中央信号分子。我们最近观察到I/R后在脑EC中暂时上调HSP27。但是，Hsp27在I/R之后EC和基本机制的EC功能完整性中的确切作用仍然未知。 使用过表达HSP27的转基因小鼠和慢病毒基因转染方法，我们获得了新型的试点数据，表明Hsp27过表达可保护内皮免受I/R诱导的体外和体内的高渗透性的影响。 HSP27抑制了氧葡萄糖剥夺诱导的肌动蛋白聚合和EC中连接蛋白的重新分布。静脉注射的HSP27含有可渗透转导域（TAT-HSP27）的HSP27，使蛋白质能够快速递送到脑微血管中，减少了BBB损伤并抑制了I/R后MMP2/9活性。该建议将进一步探讨HSP27对I/R脑损伤的BBB保护作用，并阐明基本机制。要测试的中心假设是，HSP27通过在I/R之后早期稳定微脉管系统的EC细胞骨架组织来保护BBB免受I/R损伤，并抑制MMP2/9的产生以及促炎性蛋白。提出了以下具体目的：目标1：确定HSP27的内皮靶向过表达是否足以为BBB完整性提供早期保护并赋予对脑I/R的长期保护。 AIM 2：测试HSP27通过二元机制保护内皮完整性的假设：稳定肌动蛋白细胞骨架和 抑制依赖NFKB的MMP2/9产生和炎症。 AIM 3：检验以下假设：卒中后TAT-HSP27递送到EC可预防BBB损害并改善年轻小鼠和老年小鼠的预后。 拟议的研究试图将HSP27发展为一种新型的，临床上可行的治疗策略，以改善中风后BBB损伤，刹车降低脑损伤的进展并改善中风受害者的长期神经功能。这项拟议的研究的成功完成将有助于改善中风的退伍军人的生活质量。