HECT-domain E3 Ligase and Acute Lung Injury

HECT 域 E3 连接酶与急性肺损伤

• 批准号: 9152533
• 负责人: Beibei Chen
• 金额: $ 50.77万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9152533
• 关键词: Acute; Acute Lung Injury; Adrenal Cortex Hormones; Adult Respiratory Distress Syndrome; Affect; Anti-Inflammatory Agents; Anti-inflammatory; Attenuated; Bacteria; Bacterial Infections; Behavior; CISH gene; Cartoons; Cells; Clinical; Cytokine Signaling; Data; Development; Disease; Effector Cell; Functional disorder; Gene Activation; Generations; Immune; Immune response; Immune system; In Vitro; Infection; Inflammation; Inflammation Mediators; Inflammatory; Inflammatory Response; Injury; Interleukin-1; Invaded; Knock-out; Knockout Mice; Lead; Link; Lung; Lung Inflammation; Measures; Mediating; Modeling; Molecular; Molecular Models; Molecular Target; Natural Immunity; Organ failure; Orphan; PRKCA gene; Pathway interactions; Patients; Peripheral Blood Mononuclear Cell; Phase III Clinical Trials; Phosphotransferases; Pneumonia; Process; Production; Proteins; Pseudomonas aeruginosa; Pulmonary Edema; Quantitative Structure-Activity Relationship; Regulation; Regulatory Pathway; STAT protein; Sampling; Sepsis; Severities; Shock; Signal Transduction; Signaling Protein; Staging; Stream; Structure; Surface; T-Lymphocyte; TLR4 gene; TNF gene; Testing; Therapeutic; Therapeutic Intervention; Tissues; Toxic effect; Ubiquitin; Ubiquitination; base; cohort; cytokine; design; genetic variant; improved; in vivo; lung injury; macrophage; microbial; molecular modeling; mortality; multicatalytic endopeptidase complex; novel; novel marker; novel strategies; pathogen; prevent; protein degradation; receptor; response; small molecule; small molecule inhibitor; targeted treatment; ubiquitin-protein ligase

Acute Respiratory Distress Syndrome (ARDS) affects almost a quarter million patients annually and has a mortality rate of over 40%. Its primary causes are pneumonia and sepsis. Central to the pathophysiology of this lung injury is a sustained immune response. With an exaggerated immune response, NF-κB mediated cytokine release leads to the devastating effects of pulmonary edema, multi-organ failure, and shock. Recently, we discovered a novel pathway for inflammation through protein ubiquitination, a universal mechanism whereby ubiquitin E3 ligases target proteins for degradation. We discovered that a pro-inflammatory, orphan HECT- domain ubiquitin (Ub) E3 ligase, termed KIAA0317, is activated after microbial infection. This E3 ligase ubiquitinates a potent anti-inflammatory protein termed SOCS2 (Suppressor of Cytokine Signaling 2), thereby marking it for degradation in the proteasome. SOCS2 not only suppresses the activation of signal transducers and activators of transcription (STATs), but also prevents NF-κB-dependent gene activation. Maneuvers designed to selectively modulate the abundance of SOCS2 might serve as a novel strategy for therapeutic intervention. However, to date, very little is known regarding the molecular regulation of SOCS2 at the level of protein stability. Our preliminary data suggest that (i) bacteria activates KIAA0317, which is sufficient to ubiquitinate and mediate the degradation of the inflammatory repressor SOCS2, (ii) KIAA0317 is a pro- inflammatory protein in vivo and in vitro, (iii) the kinase PKCα phosphorylates SOCS2, thereby creating a unique molecular signal for KIAA0317 targeting, and (iv) a novel small molecule inhibitor of KIAA0317, BC-1365, attenuates LPS and P. aeruginosa-induced cytokine secretion in vivo. These data led to our novel hypothesis that transcriptionally upregulated KIAA0317 specifically targets SOCS2 for ubiquitination and degradation, thus inducing inflammation and tissue injury. We will determine how KIAA0317 is regulated transcriptionally by bacterial pathogens and the molecular basis of how SOCS2 is targeted by KIAA0317, thereby upregulating NF-κB mediated inflammation. We will also determine whether KIAA0317 and its genetic variants can be used as novel biomarkers for inflammatory diseases (Aim 1). We will test KIAA0317 knockout mice in various experimental lung injury models to confirm that KIAA0317 is a druggable target. Further, we will design an optimal KIAA0317 antagonist using a quantitative structure-activity relationship (qSAR) based design and test its toxicity, target engagement, and anti-inflammatory activity both in vitro and in vivo (Aim 2). Last, this proposal unveils a new molecular model of lung injury as it relates to cytokine signaling. Our preliminary data have uncovered a novel protein, KIAA0317, which is linked to cytokine response through SOCS2 protein signaling. These studies will be the first to elucidate the enzymatic behavior of KIAA0317, which appears to activate the NF-κB-cytokine axis. Execution of these studies will lay the groundwork for a fundamental, paradigm-changing therapeutic advance for regulating innate immunity and treating inflammatory diseases that will ultimately set the stage for a new translational initiative.

急性呼吸窘迫综合征（ARDS）每年影响近25万患者 并且死亡率超过40％。它的主要原因是肺炎和败血症。中心 这种肺损伤的病理生理是一种持续的免疫反应。夸张 免疫反应，NF-κB介导的细胞因子释放导致毁灭性影响 肺水肿，多器官故障和冲击。最近，我们发现了一种新颖的途径 通过蛋白质泛素化炎症，这是一种普遍的机制，泛素E3 连接酶靶向蛋白质进行降解。我们发现一种促炎的孤儿 在微生物感染后激活域泛素（UB）E3连接酶，称为KIAA0317。这个E3 连接酶泛素可将潜在的抗炎蛋白称为SOCS2（细胞因子的抑制剂） 信号2），从而将其标记为蛋白酶体中的降解。 SOCS2不仅抑制 信号换能器和转录激活因子（统计）的激活，但也可以防止 NF-κB依赖性基因激活。旨在选择性调制抽象的操作 SOCS2可能是治疗干预的新策略。但是，到目前为止，非常 关于SOCS2在蛋白质稳定水平下的分子调节，知之甚少。我们的 初步数据表明（i）细菌激活KIAA0317，这足以泛素化 并介导炎症复制品SOCS2的降解，（ii）kiaa0317是一种 体内和体外炎性蛋白，（iii）激酶PKCα磷酸化，从而使SOCS2磷酸化 为KIAA0317靶向创建独特的分子信号，（iv）一种新型的小分子 KIAA0317，BC-1365的抑制剂，减弱LPS和铜绿假单胞菌诱导的细胞因子分泌 体内。这些数据导致了我们的新假设，即转录更新 KIAA0317专门针对SOCS2用于泛素化和降解，因此诱导 炎症和组织损伤。我们将确定KIAA0317如何受到转录的调节 通过细菌病原体和SOCS2的分子基础。 从而上调NF-κB介导的炎症。我们还将确定KIAA0317是否 它的遗传变异可以用作炎症性疾病的新生物标志物（AIM 1）。我们 将在各种实验性肺损伤模型中测试KIAA0317敲除小鼠，以确认 KIAA0317是可吸毒的目标。此外，我们将使用A设计一个最佳KIAA0317拮抗剂 基于定量的结构活性关系（QSAR）设计并测试其毒性，目标 参与度和体内的抗炎活性（AIM 2）。最后，这个建议 揭示了与细胞因子信号传导相关的肺损伤的新分子模型。我们的 初步数据已经发现了一种新型蛋白质KIAA0317，该蛋白与细胞因子有关 通过SOCS2蛋白信号的响应。这些研究将是第一个阐明 KIAA0317的酶促行为，它似乎激活了NF-κB-cytokine轴。执行 这些研究将为基本的，范式改变的疗法奠定基础 促进控制先天免疫和治疗炎症性疾病的进步 为新翻译的计划奠定了基础。