GPR4 in blood brain barrier dysfunction in brain ischemia

GPR4在脑缺血血脑屏障功能障碍中的作用

基本信息

批准号：
10652655
负责人：
Xiangming Zha
金额：
$ 38.72万
依托单位：
UNIVERSITY OF MISSOURI KANSAS CITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-07-01 至 2027-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10652655
关键词：
3-Dimensional ASIC channel Acidosis Acids Acute Address Adhesions Alteplase Animal Model Anions Attenuated Behavioral Blood Blood - brain barrier anatomy Blood brain barrier dysfunction Brain Brain Injuries Brain Ischemia Carbon Dioxide Cells Cerebrovascular system Cerebrum Chloride Channels Chronic Phase Data Disease Drug Kinetics Endothelial Cells Endothelium Epithelial Cells Evans blue stain Exhibits Extravasation FDA approved Functional disorder G-Protein-Coupled Receptors GPR4 gene GPR68 gene Human Impairment In Vitro Inflammatory Intercellular Junctions Intervention Ischemia Ischemic Stroke Knowledge Mediating Mediator Microglia Middle Cerebral Artery Occlusion Modeling Molecular Mus Neuronal Injury Neurons Outcome Patients Pattern Performance Peripheral Pharmaceutical Preparations Phase Phenotype Prevalence Process Protons Reperfusion Therapy Research Role Signal Induction Signal Transduction Site Stroke Testing Tight Junctions Tissues Vasodilation blood-brain barrier disruption blood-brain barrier permeabilization brain endothelial cell cell type clinically relevant design disability experimental study extracellular functional improvement genetic manipulation gut inflammation improved in vitro Model in vivo in vivo Model inhibitor insight ischemic injury liquid chromatography mass spectrometry middle cerebral artery neuroprotection new therapeutic target novel pharmacologic receptor stroke outcome stroke therapy therapeutic target transcriptome transcriptome sequencing

项目摘要

ABSTRACT Brain microvascular endothelial cells (BMEC), tightly connected through tight junctions and adhesions junctions, provide the structural basis for the blood-brain barrier (BBB). In both human patients and animal models, BBB disruption exhibits positive correlation with stroke outcome. Discovering novel mechanisms to protect endothelial barrier integrity will provide important insights into better therapeutic targeting of ischemia-reperfusion-induced neuronal injury. One prevalent process in brain ischemia is the prolonged reduction of brain pH, which implicates protons as an important extracellular signal. In previous studies, most emphasis on brain proton signaling has been on its role in neurons. In contrast, few studies have assessed whether acidosis alters blood-brain barrier integrity, which is one important contributor to ischemia-induced neuronal injury. This application will focus on GPR4, a proton-sensitive G protein-coupled receptor which exhibits abundant expression in BMEC. Using a combination of in vivo and in vitro models, the proposed research will determine whether GPR4 mediates acid signaling in BMEC, and identify its downstream mediator in acidotic and ischemic conditions. With genetic manipulation and pharmacological interventions, we will determine whether deleting or inhibiting GPR4 specifically in endothelial cells attenuates ischemia-induced BMEC dysfunction and protects the brain from ischemia-induced neuronal injury. To better understand the mechanism, the research will analyze downstream signaling and perform unbiased analysis of transcriptome changes from acutely isolated BMEC. Lastly, this study will use the liquid chromatography-mass spectrometry approach to determine the pharmacokinetics of a GPR4 inhibitor in brain and blood tissue. Once successfully accomplished, the study will offer GPR4 inhibition as a novel neuroprotective approach to alleviate ischemia-induced brain injury.

抽象的脑微血管内皮细胞（BMEC）通过紧密连接和粘附连接紧密连接，为血脑屏障（BBB）提供结构基础。在人类患者和动物模型中，BBB 破坏与中风结果呈正相关。发现保护内皮细胞的新机制屏障完整性将为缺血再灌注诱导的更好的治疗靶向提供重要见解神经元损伤。脑缺血的一个普遍过程是大脑 pH 值的长期降低，这意味着质子作为重要的细胞外信号。在之前的研究中，最强调的是脑质子信号传导一直在研究它在神经元中的作用。相比之下，很少有研究评估酸中毒是否会改变血脑屏障完整性，这是缺血引起的神经元损伤的重要因素之一。该应用程序将重点关注 GPR4 是一种质子敏感的 G 蛋白偶联受体，在 BMEC 中表现出丰富的表达。使用结合体内和体外模型，拟议的研究将确定 GPR4 是否介导酸 BMEC 中的信号传导，并鉴定其在酸中毒和缺血条件下的下游介质。具有遗传性操纵和药物干预，我们将确定是否删除或抑制 GPR4 特别是在内皮细胞中，可以减轻缺血引起的 BMEC 功能障碍，并保护大脑免受缺血引起的神经元损伤。为了更好地理解该机制，研究将分析下游信号传导并对急性分离的 BMEC 的转录组变化进行公正的分析。最后，本研究将使用液相色谱-质谱法来确定 GPR4 的药代动力学脑和血液组织中的抑制剂。一旦成功完成，该研究将提供 GPR4 抑制作为减轻缺血引起的脑损伤的新型神经保护方法。