Kruppel-like factor 11 and ischemic stroke

Kruppel 样因子 11 与缺血性中风

• 批准号: 9243321
• 负责人: Kejie Yin
• 金额: $ 33.4万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-11-11 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9243321
• 关键词: Acute; Adenoviruses; Adhesions; Adult; Agonist; Astrocytes; Attenuated; Basement membrane; Binding Sites; Blood; Blood - brain barrier anatomy; Blood Vessels; Brain; Brain Infarction; Brain Injuries; Capillary Endothelial Cell; Cardiovascular system; Cause of Death; Cell Death; Cerebral Ischemia; Cerebrovascular system; Cerebrum; Coculture Techniques; Development; Diabetes Mellitus; Diabetic mouse; Differentiation and Growth; Edema; Event; Exposure to; Extracellular Matrix; Extravasation; Family; Family member; Functional disorder; Genes; Genetic; Genetic Transcription; Glucose; Hemorrhage; Human; Hyperglycemia; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Ischemia; Ischemic Stroke; Kruppel-like transcription factors; Lead; Leukocytes; Mediating; Mediator of activation protein; Messenger RNA; Middle Cerebral Artery Occlusion; Modeling; Molecular; Mus; Mutation; Neurological outcome; Neuronal Dysfunction; Neurons; Neutrophil Infiltration; Non-Insulin-Dependent Diabetes Mellitus; Oxygen; PPAR gamma; Pathogenesis; Pathologic; Pathology; Pericytes; Permeability; Peroxisome Proliferator-Activated Receptors; Pharmacologic Substance; Play; Process; Promoter Regions; Property; Receptor Signaling; Recruitment Activity; Regulation; Reporting; Risk Factors; Role; Signal Transduction; Stimulus; Stroke; Testing; Therapeutic Intervention; Thrombolytic Therapy; Tight Junctions; Time; Transgenic Mice; United States; Vascular Endothelium; Zinc Fingers; brain endothelial cell; cell growth; cell water; cerebrovascular; deprivation; disability; effective therapy; foot; in vivo; member; neuron loss; non-diabetic; novel; public health relevance; transcription factor; vasogenic edema

 DESCRIPTION (provided by applicant): The blood-brain barrier (BBB) damage and dysfunction is well-recognized as a major hallmark of ischemic stroke. As a major component of the BBB, brain microvascular endothelial cells (BMECs), together with the tight junctions (TJs) between BMECs, play a dominant role in modulating BBB integrity and paracellular permeability. Extensive studies have shown that breakdown of the BBB contributes to cerebral inflammatory responses, edema, hemorrhagic transformation, and eventual neuronal loss in cerebral ischemia. Thus, it is important to identify mechanisms by which BBB integrity and function can be compromised in ischemic stroke. Krüppel-like factors (KLFs) are members of the zinc finger family of transcription factors and consist of 17 members that have been shown to play key roles in cellular growth and differentiation. Recent studies have documented that KLFs are implicated in developmental and pathological vascular processes. However, the function of the KLF family in the cerebral vasculature is largely unexplored. KLF11 is a unique diabetes- associated KLF transcription factor among 17 KLF family members and highly expresses in vascular endothelium. Mutations in the KLF11 gene result in Maturity Onset Diabetes of the Young 7 (MODY7), and are closely associated with human type 2 diabetes mellitus, a major risk factor for stroke. Previously, we reported that peroxisome proliferator-activated receptor γ-mediated cerebral vascular protection during ischemic insults needs recruitment of KLF11 as its critical co-activator. However, the functional significance and mechanisms of KLF11 itself in regulating cerebrovascular pathogenesis are totally unknown in ischemic stroke. In our recent preliminary studies, we have shown that KLF11 expression is significantly decreased in the cerebral vasculature, and also in cultured BMECs after in vivo and in vitro ischemic stimuli. Of note, EC- selective KLF11 transgenic mice display reduced BBB leakage in ischemic brains, whereas KLF11 genetic deficiency results in increased BBB permeability and larger brain infarction in mice after middle cerebral artery occlusion (MCAO). Mechanistically, we found several potential KLF11 binding sites in the promoter region of selective endothelial tight junctions, and genetic deletion of KLF11 in mice significantly reduced cerebral expression of Claudin 5 and ZO-1 mRNAs as well as increased leukocyte-endothelial rolling and adhesion in the vascular wall. Moreover, we also demonstrated that gain-of-KLF11 function by adenovirus can significantly inhibit BMEC death after exposure to Oxygen Glucose Deprivation (OGD). These findings have provided the basis for our Central Hypothesis that endothelial KLF11 functions as a novel BBB stabilizer and its reduction contributes to BBB dysfunction and brain injury after ischemic stroke. Three aims will be performed in this proposal. Aim 1: Define the role of KLF11 in BBB dysfunction and brain injury after ischemic stroke; Aim 2: Define the molecular mechanisms of KLF11 in regulating ischemia-induced BBB dysfunction; Aim 3: Define if activation of KLF11 by upstream signaling regulates post-ischemic BBB dysfunction.

 描述（由申请人提供）：血脑屏障（BBB）损伤和功能障碍被公认为缺血性卒中的主要标志。脑微血管内皮细胞（brain microvascular endothelial cells，BMEC）是血脑屏障的重要组成部分，其紧密连接（tightjunctions，TJ）对血脑屏障的完整性和细胞旁通透性起着重要的调节作用。广泛的研究表明，BBB的破坏有助于脑炎症反应、水肿、出血性转化和脑缺血中最终的神经元损失。因此，重要的是要确定的机制，BBB的完整性和功能可能会受到损害，缺血性中风。 Krüppel样因子（KLF）是锌指转录因子家族的成员，由17个成员组成，已被证明在细胞生长和分化中发挥关键作用。最近的研究表明，KLF与发育和病理性血管过程有关。然而，KLF家族在脑血管系统中的功能在很大程度上是未知的。KLF 11是KLF家族17个成员中唯一一个与糖尿病相关的KLF转录因子，在血管内皮细胞中高表达。KLF 11基因的突变导致年轻人7型成熟型糖尿病（MODY 7），并与人类2型糖尿病密切相关，2型糖尿病是中风的主要危险因素。以前，我们报道过过氧化物酶体增殖物激活受体γ介导的缺血性脑血管保护需要KLF 11作为其关键的共激活剂。然而，KLF 11本身在缺血性脑卒中中调节脑血管病变的功能意义和机制尚不清楚。 在我们最近的初步研究中，我们已经表明，KLF 11的表达显着减少，在脑血管系统，也在培养的BMEC后，在体内和体外缺血刺激。值得注意的是，EC选择性KLF 11转基因小鼠在缺血性脑中显示出减少的BBB渗漏，而KLF 11遗传缺陷导致大脑中动脉闭塞（MCAO）后小鼠中BBB渗透性增加和更大的脑梗死。从机制上讲，我们在选择性内皮紧密连接的启动子区域发现了几个潜在的KLF 11结合位点，并且小鼠中KLF 11的基因缺失显著降低了Claudin 5和ZO-1 mRNA的脑表达，并增加了白细胞-内皮细胞滚动和血管壁中的粘附。此外，我们还证明腺病毒获得KLF 11功能可以显著抑制暴露于氧葡萄糖脱氢酶（OGD）后BMEC的死亡。这些发现为我们的中心假设提供了基础，即内皮KLF 11作为一种新的BBB稳定剂发挥作用，其减少有助于缺血性卒中后BBB功能障碍和脑损伤。本提案将实现三个目标。目标1：明确KLF 11在缺血性卒中后BBB功能障碍和脑损伤中的作用;目的2：明确KLF 11调节缺血诱导的BBB功能障碍的分子机制;目的3：明确上游信号转导激活KLF 11是否调节缺血后BBB功能障碍。