Transcriptional and epigenetic control of angiogenic genes in sepsis-induced acute kidney injury.

脓毒症引起的急性肾损伤中血管生成基因的转录和表观遗传控制。

• 批准号: 9173657
• 负责人: KAROL BOMSZTYK
• 金额: $ 26.25万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-20 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9173657
• 关键词: ANGPT1 gene; Acute Renal Failure with Renal Papillary Necrosis; Angiopoietin-2; Angiopoietins; Antibodies; Binding Proteins; Biological Assay; Blood Vessels; Blood flow; Cell Culture Techniques; Chromatin; Clinical; Clinical Trials; Complication; Critical Illness; DNA-Binding Proteins; Data; Down-Regulation; Drug Targeting; Embryo; Endothelial Cells; Epigenetic Process; Event; Extravasation; Family member; Functional disorder; Future; Gene Expression; Genes; Genetic Transcription; Heterogeneity; Hospitalization; Human; In Vitro; Inflammation Mediators; Injury; Intervention; Kidney; Kinetics; Knock-out; Kruppel-like transcription factors; Life; Ligands; Mediating; Modeling; Molecular; Organ; Pathologic; Pathway Analysis; Patients; Pericytes; Play; Preparation; Process; Proteomics; Receptor Protein-Tyrosine Kinases; Regulation; Regulator Genes; Repression; Risk; Role; Sampling; Sepsis; Signal Transduction; Source; Testing; Time; Transgenic Mice; base; combinatorial; design; endothelial dysfunction; hypoperfusion; in vitro testing; knock-down; mortality; mouse model; novel; receptor; response; septic; tool; transcription factor

Sepsis-induced acute kidney injury (AKI) is the most common and life-threatening cause of renal injury in critically ill patients. And yet, there have been no improvements in the treatment of septic AKI in decades. Septic AKI is distinct from non-septic AKI; notably - microcirculatory dysfunction manifested by low blood flow, endothelial cell (EC) activation and vascular leak, play a prominent pathologic roles. The microvasculature consists of luminal EC and pericytes, which encircle the abluminal endothelial wall. The EC receptor tyrosine kinase, Tie-2 (TEK), and its two ligands, angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2), (i.e., Ang-Tie-2 axis) regulate microvasculature. Pericytes are the primary source of Ang-1, which maintains EC quiescence via Tie-2 signaling. Tie-2 expression/signaling is, part, regulated by blood flow, a process that involves transcription factor, Klf2. Tie-2 and Ang-1 gene expression is downregulated in septic kidney, contributing to EC dysfunction. Changes in Tie-2/ Ang-1 expression are associated with epigenetic alterations and loss of Klf2 at these loci. We will test the hypothesis that sepsis-induced Klf2 disengagement from Ang-1 and Tie-2 genes alters dynamic network(s) of transcription and epigenetic factors interacting along Ang-1 and Tie-2 loci which down-regulates their transcription and contributes to endothelial leak. Aim #1. To define kinetics of transcription/epigenetic network changes associated with disengagement of Klf2 from renal Ang-1 and Tie-2 genes in mouse models of sepsis. Correlating kinetics of sepsis-induced transcription/epigenetic alterations at the renal Ang-1 and Tie-2 genes with progression to endothelial leak will identify Klf2-dependent and -independent interactions that will be tested in vitro (Aims #2-3) for their role inTie-2 and Ang-1 expression. Aim #2. To use EC and pericyte cultures to define which interactions of chromatin-bound proteins act (additively, synergistically or antagonistically) to regulate Tie-2 and Ang-1 transcription. Mechanism of Tie-2 and Ang-1 repression will be studied by knocking down/inhibiting candidate factors (e.g., HDACs) tethered to these loci. Aim #3. To characterize which of transcription/epigenetic factor interactions at Tie-2 and Ang-1 loci are responsive to flow/inflammatory mediators and regulate microvascular barrier in in vitro 3D- flow microvessels. We will take advantage of our synthetic human kidney microvessels that model endothelial leak to identify flow-responsive transcription/epigenetic interactions that regulate Ang-1 and Tie-2 genes. We have recently demonstrated, previously unanticipated, epigenetic heterogeneity and uniqueness of gene responses during AKI. Thus, defining key transcription/epigenetic network components engaged at Ang-1 and Tie-2 genes as potential drug targets will provide translational basis for future testing combinatorial rationally- designed pharmacologic interventions to mitigate microvascular leak and kidney injury during sepsis.

脓毒症诱导的急性肾损伤（阿基）是肾损伤的最常见和危及生命的原因， 危重病人。然而，几十年来脓毒性阿基的治疗没有改善。 脓毒性阿基与非脓毒性阿基不同;特别是-微循环功能障碍表现为低血流量， 内皮细胞（EC）活化和血管渗漏，起着突出的病理作用。微脉管系统 由腔EC和周细胞组成，周细胞环绕腔外内皮壁。EC受体酪氨酸 激酶Tie-2（TEK）及其两种配体血管生成素-1（Ang-1）和血管生成素-2（Ang-2），（即，昂铁二号 轴）调节微血管。周细胞是Ang-1的主要来源，Ang-1通过调节内皮细胞的增殖来维持EC的静止。 Tie-2信令。Tie-2表达/信号传导部分受血流调节，这一过程涉及 转录因子Klf 2。Tie-2和Ang-1基因表达在脓毒症肾中下调，有助于EC 功能障碍Tie-2/ Ang-1表达的变化与表观遗传学改变和Klf 2的丢失相关， 这些地方。我们将检验脓毒症诱导Klf 2与Ang-1和Tie-2脱离的假设 基因改变了转录和表观遗传因子的动态网络，这些因子沿着沿着Ang-1相互作用， Tie-2基因座下调其转录并导致内皮渗漏。 目标1。为了定义与以下相关的转录/表观遗传网络变化的动力学： 在脓毒症小鼠模型中Klf 2与肾Ang-1和Tie-2基因的分离。相关动力学 脓毒症诱导的肾脏Ang-1和Tie-2基因转录/表观遗传学改变， 内皮渗漏将确定Klf 2依赖性和非依赖性相互作用，并将在体外进行测试（目的#2-3） 表达Tie-2和Ang-1。 目标2。使用EC和周细胞培养来确定染色质结合的 蛋白质起作用（相加、协同或拮抗）调节Tie-2和Ang-1转录。 Tie-2和Ang-1抑制的机制将通过敲除/抑制候选因子（例如， HDACs）与这些基因座相连。 目标3。为了表征Tie-2和Ang-1的转录/表观遗传因子相互作用， 基因座对流动/炎症介质有反应，并在体外3D- 流动微血管我们将利用我们的人造人肾微血管模型内皮细胞， 以鉴定调节Ang-1和Tie-2基因的流动响应性转录/表观遗传相互作用。 我们最近发现，以前没有预料到，表观遗传异质性和基因的独特性， 阿基期间的反应。因此，定义参与Ang-1和Ang-2的关键转录/表观遗传网络组件， Tie-2基因作为潜在的药物靶点将为未来的组合合理性测试提供翻译基础- 设计了药物干预措施，以减轻败血症期间的微血管渗漏和肾损伤。