UBXN1 Regulates Inflammasome Signaling

UBXN1 调节炎症体信号传导

基本信息

批准号：
10664342
负责人：
PENGHUA WANG
金额：
$ 20.67万
依托单位：
UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-02-21 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10664342
关键词：
ATP phosphohydrolase Address Age Apoptosis Binding CASP1 gene Carcinoma Caspase Cell Cycle Cell Death Cell membrane Cells Cellular Stress Cervical Cessation of life Embryo Endoplasmic Reticulum Endotoxemia Endotoxins Foundations Future Genes Hela Cells Histopathology Human Human Characteristics Human Genome Human body Hyperactivity IL18 gene Immune response Impairment Infection Inflammasome Inflammation Mediators Inflammatory Inflammatory Response Interferon Type II Interleukin-1 Kinetics Knock-out Knockout Mice Learning Life Link Lipopolysaccharides Macrophage Mediating Methods Modeling Molecular Multiprotein Complexes Mus Pathogenesis Pathology Pathway interactions Pattern recognition receptor Physiological Plasma Cells Play Process Production Proteins Receptor Signaling Research Resistance Rodent Role Sepsis Signal Transduction Solid TLR4 gene Testing Transfection Transgenic Mice Ubiquitin United States cecal ligation puncture effective therapy in vivo mouse model new therapeutic target novel therapeutic intervention polymicrobial sepsis pre-clinical protein degradation recruit response sex therapeutic target therapeutically effective tool trafficking ubiquitin-protein ligase

项目摘要

Sepsis is a life-threatening illness due to the human body’s extreme inflammatory response to infection. There are >1.5 million cases of sepsis and >250,000 sepsis-related deaths each year in the United States. However, there are no effective therapies. Hyperactive inflammasomes are involved in the pathogenesis of sepsis and could be therapeutically targeted to save lives. Inflammasomes are large cytosolic multiprotein complexes formed in response to infections and cellular stresses that drive auto-activation of inflammatory caspases (Caspase-1, -4, -5), production of inflammatory mediators [interleukin (IL) -1 and -18)], and pyroptosis, a form of cell death. Canonical inflammasomes are assembled by a pattern recognition receptor (PRR), an adaptor ASC (optional) and Caspase-1. Non-canonical inflammasomes are activated by direct binding of a bacterial endotoxin lipopolysaccharide (LPS) to Caspase-4/5 (mouse Caspase-11), which oligomerizes and cleaves Gasdermin D (GSDMD). Active GSDMD induces pore formation in the plasma membrane and cell death. Although much has been learned about the regulatory mechanisms for canonical inflammasomes, little is known for non-canonical inflammasomes. To address this gap, we recently identified an ubiquitin regulatory X (UBX) domain-containing protein 1 (UBXN1) involved in non-canonical inflammasome-mediated sepsis, and believe that validating its role in this process will reveal new treatment strategies. To begin uncovering its function, we generated the first inducible global Ubxn1 knockout mouse model—a critical tool, as early global knockout is embryonically lethal. Using this model, we found that Ubxn1-/- mice were highly resistant to lethal LPS endotoxemia and cecal- ligation-and-puncture (CLP)-elicited polymicrobial sepsis, compared to sex- and age-matched Ubxn1+/+ littermates. Accordingly, the levels of IL-1, IL-18, and GSDMD/Caspase-11 activation were reduced in Ubxn1-/- mice. Of note, GSDMD and Caspase-11 activation in response to LPS was reduced in primary Ubxn1-/- macrophages as well. This UBXN1 function is conserved in human cells. Both Caspase-4/GSDMD activation and pyroptosis were impaired in IFN-γ-primed, LPS-transfected UBXN1-/- HeLa cells. Moreover, UBXN1 interacted with LPS and Caspase-4. These results support our hypothesis that UBXN1 positively regulates non- canonical inflammasome signaling and thus contributes to sepsis pathogenesis. We will prove this by pinpointing the molecular mechanism of UBXN1 action on the Caspase-4/11-LPS, and by characterizing the physiological role of UBXN1 in CLP sepsis. UBXN1 protein is highly conserved between rodents and humans (93% identical), so is its function in inflammasome signaling. By using the CLP method, our studies should provide pre-clinical evidence relevant to human sepsis. Successful completion of this R21 will lay a solid foundation for more in-depth mechanistic and functional studies in a future R01 application.

败血症是一种由于人体对感染产生极端炎症反应而危及生命的疾病。美国每年有超过 150 万脓毒症病例和超过 25 万例脓毒症相关死亡。没有有效的治疗方法。过度活跃的炎症小体参与脓毒症的发病机制。炎症小体是一种大型胞质多蛋白复合物。响应感染和细胞应激而形成，驱动炎性半胱天冬酶的自动激活（Caspase-1、-4、-5）、炎症介质 [白细胞介素 (IL) -1 和 -18)] 的产生以及细胞焦亡（细胞焦亡的一种形式）典型的炎症小体由模式识别受体 (PRR)（一种适配器 ASC）组装而成。（可选）和 Caspase-1 通过直接结合细菌内毒素而被激活。脂多糖 (LPS) 转化为 Caspase-4/5（小鼠 Caspase-11），寡聚并裂解 Gasdermin D (GSDMD)。活性 GSDMD 会诱导质膜中的孔形成和细胞死亡。人们对典型炎症小体的调节机制了解甚少，但对非典型炎症小体的调节机制知之甚少为了解决这一空白，我们最近发现了一个包含泛素调节 X (UBX) 结构域的物质。蛋白 1 (UBXN1) 参与非典型炎症小体介导的脓毒症，并认为验证其作用在此过程中将揭示新的治疗策略为了开始揭示其功能，我们生成了第一个。诱导性全局 Ubxn1 敲除小鼠模型 - 一个重要的工具，因为早期全局敲除在胚胎上是致命的。使用该模型，我们发现 Ubxn1-/- 小鼠对致命的 LPS 内毒素血症和盲肠具有高度抵抗力。与性别和年龄匹配的 Ubxn1+/+ 相比，结扎穿刺 (CLP) 引发多种微生物败血症因此，Ubxn1-/- 中的 IL-1、IL-18 和 GSDMD/Caspase-11 激活水平降低。值得注意的是，原代 Ubxn1-/- 小鼠中对 LPS 的 GSDMD 和 Caspase-11 激活有所减少。巨噬细胞中的 UBXN1 功能在人类细胞中也是保守的。在 IFN-γ 引发、LPS 转染的 UBXN1-/- HeLa 细胞中，细胞焦亡受到损害。与 LPS 和 Caspase-4 相互作用。这些结果支持我们的假设，即 UBXN1 正向调节非- 典型的炎性体信号传导，从而促进败血症的发病机制，我们将通过精确定位来证明这一点。 UBXN1 对 Caspase-4/11-LPS 作用的分子机制，并通过表征生理学 UBXN1 在 CLP 脓毒症中的作用。 UBXN1 蛋白在啮齿类动物和人类之间高度保守（93% 相同），因此其功能在通过使用 CLP 方法，我们的研究应该提供相关的临床前证据。 R21的成功完成将为更深入的机制奠定坚实的基础。以及未来 R01 应用中的功能研究。