Kruppel-like factor 11 and ischemic stroke

Kruppel 样因子 11 与缺血性中风

• 批准号: 9063097
• 负责人: Kejie Yin
• 金额: $ 33.69万
• 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/9063097
• 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; Edema; Event; Exposure to; Extracellular Matrix; Extravasation; Family; Family member; Functional disorder; Genes; Genetic; Glucose; Health; Human; Hyperglycemia; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Ischemia; Ischemic Stroke; Lead; Leukocytes; Mediating; Mediator of activation protein; Messenger RNA; Middle Cerebral Artery Occlusion; Modeling; Molecular; Mus; Mutation; Neurological outcome; Neurons; Neutrophil Infiltration; Non-Insulin-Dependent Diabetes Mellitus; Oxygen; PPAR gamma; Pathogenesis; Pathology; Pericytes; Permeability; Peroxisome Proliferator-Activated Receptors; Pharmacologic Substance; Play; Process; Promoter Regions; Property; Receptor Signaling; Regulation; Reporting; Risk Factors; Role; Signal Transduction; Stimulus; Stroke; Testing; Therapeutic Intervention; Thrombolytic Therapy; Tight Junctions; Time; Transgenic Mice; United States; Vascular Endothelium; Work; Zinc Fingers; base; brain endothelial cell; cell growth; cell water; cerebrovascular; deprivation; disability; effective therapy; in vivo; member; neuron loss; non-diabetic; novel; 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)的损害和功能障碍被公认为缺血性中风的主要标志。脑微血管内皮细胞(BMECs)作为血脑屏障的主要组成部分，与脑微血管内皮细胞之间的紧密连接(TJ)一起，在调节血脑屏障完整性和细胞旁通透性方面起着主导作用。大量研究表明，脑缺血时血脑屏障的破坏会导致脑炎症反应、脑水肿、出血性转化以及最终的神经元丢失。因此，确定缺血性卒中中血脑屏障完整性和功能受损的机制是很重要的。KRüppel样因子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起关键作用。最近的研究证明，KLFS与发育和病理血管过程有关。然而，KLF家族在脑血管系统中的功能在很大程度上还没有被探索。KLF11是17个KLF家族成员中唯一的糖尿病相关KLF转录因子，在血管内皮细胞中高表达。KLF11基因突变导致7岁以下青年成熟期糖尿病(MODY7)，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。在此之前，我们曾报道过γ介导的脑缺血损伤时的脑血管保护作用需要重新招募KLF11作为其关键的辅助激活因子。然而，KLF11自身在缺血性卒中中调节脑血管发病机制的功能意义和机制尚不清楚。在我们最近的初步研究中，我们发现KLF11在脑血管中的表达显著减少，在体内和体外缺血刺激后培养的骨髓内皮细胞中也明显减少。值得注意的是，EC选择性的KLF11转基因小鼠显示出缺血脑中血脑屏障渗漏的减少，而KLF11基因缺陷导致小鼠大脑中动脉阻塞(MCAO)后血脑屏障通透性增加和更大的脑梗塞。在机制上，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KLF11结合位点，并且KLF11的基因缺失显著降低了脑组织Claudin 5和ZO-1mRNAs的表达，并增加了白细胞-内皮细胞在血管壁的滚动和黏附。此外，我们还证明了腺病毒获得KLF11功能可以显著抑制缺氧缺糖(OGD)后BMEC的死亡。这些发现为我们的中心假设提供了基础，即内皮细胞KLF11作为一种新的BBB稳定剂发挥作用，它的减少有助于缺血性卒中后BBB功能障碍和脑损伤。这项提案将实现三个目标。目的1：明确KLF11在缺血性卒中后血脑屏障功能障碍和脑损伤中的作用；目的2：明确KLF11调节缺血后血脑屏障功能障碍的分子机制；目的3：确定上游信号通路激活KLF11是否调节缺血后血脑屏障功能障碍。