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 死亡率超过40%其主要原因是肺炎和败血症。的核心 这种肺损伤的病理生理学是持续的免疫应答。与夸大的 在免疫应答中，NF-κB介导的细胞因子释放导致 肺水肿多器官衰竭和休克最近，我们发现了一种新的途径， 炎症通过蛋白质泛素化，一个普遍的机制，其中泛素E3 连接酶靶向蛋白质进行降解。我们发现一种促炎的孤儿HECT- 结构域泛素（Ub）E3连接酶，称为KIAA 0317，在微生物感染后被激活。本届E3 连接酶泛素化一种称为SOCS 2（细胞因子抑制因子）的强效抗炎蛋白 信号2），从而标记它在蛋白酶体中的降解。SOCS 2不仅抑制了 信号转导和转录激活因子（STAT）的激活，但也防止 NF-κ B依赖性基因激活。机动设计，以选择性地调节丰度 SOCS 2可能作为一种新的治疗干预策略。然而，迄今为止， 关于SOCS 2在蛋白质稳定性水平上的分子调节知之甚少。我们 初步数据表明，（i）细菌激活KIAA 0317，这足以泛素化 并介导炎性阻遏物SOCS 2的降解，（ii）KIAA 0317是一种促炎性细胞因子， （iii）激酶PKCα磷酸化SOCS 2，从而 产生KIAA 0317靶向的独特分子信号，和（iv）一种新的小分子 KIAA 0317抑制剂BC-1365减弱LPS和铜绿假单胞菌诱导的细胞因子分泌 in vivo.这些数据导致我们的新假设，转录上调 KIAA 0317特异性靶向SOCS 2进行泛素化和降解，从而诱导 炎症和组织损伤。我们将确定KIAA 0317如何受到转录调节 以及SOCS 2如何被KIAA 0317靶向的分子基础， 从而上调NF-κB介导的炎症。我们还将确定KIAA 0317是否 并且其遗传变体可用作炎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KIAA 0317基因敲除小鼠，以证实 KIAA 0317是一个可被下药的目标。此外，我们将设计一个最佳的KIAA 0317拮抗剂， 基于定量构效关系（qSAR）设计并测试其毒性、靶向 接合和体外和体内的抗炎活性（目的2）。最后，本提案 揭示了一种新的肺损伤分子模型，因为它与细胞因子信号传导有关。我们 初步的数据已经发现了一种新的蛋白质，KIAA 0317，它与细胞因子有关， 通过SOCS 2蛋白信号传导的反应。这些研究将首次阐明 KIAA 0317的酶行为，其似乎激活NF-κ B-细胞因子轴。执行 这些研究将为一种根本的、改变范式的治疗方法奠定基础。 调节先天免疫和治疗炎症性疾病的进展， 为一个新的翻译倡议奠定了基础。