MicroRNA-181b and Sepsis

MicroRNA-181b 和脓毒症

基本信息

批准号：
8944822
负责人：
Rebecca M Baron
金额：
$ 46.25万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-15 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8944822
关键词：
3&apos Untranslated Regions Adhesions Adhesives Adult Respiratory Distress Syndrome Anti-Inflammatory Agents Anti-inflammatory Binding Biological Biological Assay Biological Markers Blood Vessels Bronchoalveolar Lavage Fluid Cause of Death Cell Adhesion Cell Adhesion Molecules Cell Communication Cell physiology Cessation of life Clinical Critical Illness Data Disease E-Selectin Endothelial Cells Endotoxemia Event Experimental Models Extravasation Foundations Functional disorder Gene Targeting Generations Genetic Goals Human Importins Infection Inflammation Inflammation Mediators Inflammatory Injury Laboratories Lead Leukocytes Link Lung Mediator of activation protein MicroRNAs Modeling Molecular Mus Mutation NF-kappa B NFKB Signaling Pathway Nuclear Translocation Organ Organ failure Outcome PTGS2 gene Pathogenesis Pathway interactions Patients Permeability Phosphoric Monoester Hydrolases Phosphorylation Plasma Plasminogen Activator Inhibitor 1 Production Property Proteins Proto-Oncogene Proteins c-akt Regulation Replacement Therapy Reporter Genes Resveratrol Role Sampling Sepsis Sepsis Syndrome Septic Shock Severities Signal Transduction Small Interfering RNA Stimulus Therapeutic Thrombin Thrombosis Time Tissues Tumor Necrosis Factor-alpha Untranslated RNA Untranslated Regions Vascular Cell Adhesion Molecule-1 Vascular Diseases Vascular Endothelium Vascular Permeabilities base crosslinking and immunoprecipitation sequencing cytokine endothelial dysfunction human subject improved in vivo inflammatory marker insight intravenous administration intravital microscopy lung injury monolayer mortality novel novel therapeutic intervention overexpression protective effect public health relevance response septic small molecule therapy development transcriptome sequencing vascular inflammation

项目摘要

DESCRIPTION (provided by applicant): Accumulating studies highlight a critical role for endothelial cell (EC) inflammation and dysfunction in the pathogenesis of septic shock and sepsis-induced lung injury, leading causes of death among critically ill patients. Excessive generation of pro-inflammatory mediators can lead to collateral vascular dysfunction, an effect that confers pro-adhesive, pro-permeability, and pro-thrombotic properties to ECs. Therefore, modulating these events in the vascular endothelium may provide a novel therapeutic approach to limit the sequelae of sepsis and sepsis-induced lung injury. MicroRNAs (miRNAs) are small, non-coding RNAs that suppress the expression of target genes at the post-transcriptional level and are involved in a range of biological responses. However, the role of microRNAs in sepsis-associated endothelial dysfunction remains poorly defined. Using a microarray profiling approach in ECs, we identified that miR-181b expression is rapidly reduced in the vascular endothelium from endotoxemic mice - observations that are recapitulated in human subjects with sepsis in vivo. Our studies have uncovered that miR-181b inhibits targets that control 2 key signaling pathways, NF-kB and AKT/eNOS, that govern EC adhesion, vascular permeability, and proinflammatory mediators implicated in sepsis and sepsis-induced lung injury. Preliminary functional studies in ECs reveal that miR-181b potently inhibits effects on leukocyte adhesion, EC permeability, and thrombin-induced EC inflammation. MiR-181b suppresses the activation of the NF-kB pathway uniquely in ECs by binding to the 3'UTR of importin-a3, a protein involved in NF-kB nuclear translocation in ECs and not leukocytes. In contrast, miR-181b induces eNOS-phosphorylation by directly targeting the phosphatase PHLPP2, known to inhibit AKT-phosphorylation. Finally, treatment of mice by systemic intravenous administration of miR-181b mimics as "replacement therapy" reduces endotoxemia-induced EC inflammatory markers, leukocyte accumulation, lung injury, and markedly improves survival. Thus, we hypothesize that miR-181b may serve as a critical homeostatic regulator of ECs and vascular dysfunction in sepsis and sepsis-induced lung injury. To further understand the protective role of miR-181b in sepsis, we propose: in Aim1, to delineate the proximal events during sepsis regulating miR-181b expression. In Aim2, using inflammatory stimuli including human plasma samples from patients with sepsis and sepsis-induced lung injury, we will dissect the mechanisms by which miR-181b regulates NF-kB and AKT signaling in response to EC dysfunction. In Aim3, we will explore the effect and timing of altered miR-181b expression, or its targets (using genetic, siRNA, or pharmacological approaches to importin-a3 or PHLPP2), on experimental models of sepsis and EC function in vivo. Successful completion of the proposed studies will identify significant insights regarding miR-181b function in EC inflammation, vascular leak, and microvascular thrombosis, and may provide discrete, novel targets for sepsis-induced lung injury.

描述（由申请人提供）：越来越多的研究强调了内皮细胞（EC）炎症和功能障碍在脓毒性休克和脓毒症肺损伤的发病机制中的关键作用，这是危重患者死亡的主要原因。介质可导致侧支血管功能障碍，这种作用赋予 EC 促粘附、促渗透和促血栓形成的特性，因此，调节血管中的这些事件。内皮细胞可能提供一种新的治疗方法来限制脓毒症的后遗症和脓毒症引起的肺损伤，MicroRNA (miRNA) 是一种小型非编码 RNA，可在转录后水平抑制靶基因的表达，并参与一系列过程。然而，microRNA 在脓毒症相关内皮功能障碍中的作用仍不清楚，使用 EC 中的微阵列分析方法，我们发现 miR-181b 表达迅速降低。在内毒素血症小鼠的血管内皮细胞中——在患有脓毒症的人类受试者体内重现观察结果发现，miR-181b 抑制控制 2 个关键信号通路（NF-kB 和 AKT/eNOS）的靶标，这些信号通路控制 EC 粘附， EC 的初步功能研究表明，血管通透性和与脓毒症和脓毒症引起的肺损伤有关的促炎介质。 miR-181b 通过与 importin-a3（一种相关蛋白）的 3'UTR 结合，有效抑制对白细胞粘附、EC 通透性和凝血酶诱导的 EC 炎症的影响。相反，miR-181b 会诱导 EC 中的 NF-kB 核易位，而不是白细胞中的 eNOS 磷酸化。通过直接靶向已知可抑制 AKT 磷酸化的磷酸酶 PHLPP2 最后，通过全身静脉注射 miR-181b 来治疗小鼠，模拟内毒素血症诱导的 EC 炎症标志物、白细胞积聚、肺损伤的“替代疗法”，并显着提高生存率。因此，我们发现 miR-181b 可能作为脓毒症和血管功能障碍的 EC 和血管功能障碍的关键稳态调节因子。为了进一步了解 miR-181b 在脓毒症中的保护作用，我们建议：在 Aim1 中，使用包括患者血浆样本在内的炎症刺激来描述脓毒症期间调节 miR-181b 表达的近端事件。对于脓毒症和脓毒症引起的肺损伤，我们将剖析 miR-181b 调节 NF-kB 和 AKT 信号传导以应对 EC 功能障碍的机制。 Aim3，我们将探讨改变 miR-181b 表达或其靶标（使用遗传、siRNA 或药理学方法导入 a3 或 PHLPP2）对脓毒症和体内 EC 功能的实验模型的影响和时间。拟议的研究将确定有关 miR-181b 在 EC 炎症、血管渗漏和微血管血栓形成中的功能的重要见解，并可能为脓毒症引起的肺损伤提供离散的新靶标。