Dissecting interplay between electrophilic stress and IkBz-driven inflammation

剖析亲电子应激与 IkBz 驱动的炎症之间的相互作用

• 批准号: 10452024
• 负责人: Monika Bambouskova
• 金额: $ 19.69万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10452024
• 关键词: 3' Untranslated Regions; 5' Untranslated Regions; Address; Affect; Animal Model; Anti-Inflammatory Agents; Autoimmune Diseases; Cell Line; Cells; Cellular Stress Response; Characteristics; Cysteine; Data; Development; Down-Regulation; Elements; Epithelial Cells; Family; Foundations; Future; Genes; Genetic; Genetic Transcription; Genetic study; Health; Human; Immune; Immune response; In Vitro; Inflammation; Inflammatory; Interleukin-12; Interleukin-17; Interleukin-6; Investigation; Macrophage Activation; Mediating; Medical Genetics; Messenger RNA; Metabolic; Molecular; Mus; Nature; Pathology; Pathway interactions; Pharmacology; Pneumococcal Infections; Population Genetics; Production; Proteins; Psoriasis; RNA-Binding Proteins; Regulation; Regulatory Element; Role; Signal Transduction; Stress; Sulfhydryl Compounds; Susceptibility Gene; T-Lymphocyte; TNF gene; Toll-like receptors; Transcript; Translational Regulation; Translational Repression; Translations; Untranslated Regions; Up-Regulation; arm; biological adaptation to stress; cytokine; genetic approach; immune activation; immunoregulation; in vivo; macrophage; member; mouse model; novel; novel therapeutic intervention; novel therapeutics; operation; programs; response; sensor; transcription factor; treatment strategy; trigger point

Abstract Electrophilic stress is a broad phenomenon caused by compounds that are reactive to thiol groups (-SH), such as cysteine residues within cellular proteins. We found that electrophilic stress response induced by dimethyl itaconate (DI), a derivative of the metabolite itaconate, mediates a strong, yet very selective inhibitory effect on the immune activation. In macrophages, DI treatment downregulates production of a subset of cytokines such as IL-6 or IL-12 but does not affect other cytokines such as TNF. We found that this selective effect occurs through inhibition of IκBζ, a transcription factor of the NF-κB family, which is commonly induced during immune activation. IκBζ selectively regulates inflammation in several important contexts: (1) in macrophages, IκBζ regulates the secondary transcriptional response to toll-like receptor stimulation and its deficiency leads to defective production of a subset of cytokines such as IL-6 and IL-12, but not TNF; (2) in epithelial cells, IκBζ is a primary regulator of the transcriptional response to IL-17; (3) in T-cells, it is an indispensable transcription factor facilitating Th17 polarization. Importantly, medical and population genetics studies have identified NFΚBIZ (the gene encoding IκBζ) as a major susceptibility locus for psoriasis, an IL-17-associated autoimmune condition. We have demonstrated that in vivo administration of DI completely ameliorates development of pathology in a mouse model of psoriasis. Therefore, a deeper understanding of the connection between IκBζ and electrophilic stress has the strong potential to uncover novel therapeutic avenues for treatment of autoimmune conditions, such as psoriasis. Moreover, although the major studied cellular response to electrophilic stress is the Keap1/Nrf2 pathway, we show that the effect of DI on IκBζ is independent of Nrf2. Our preliminary data suggest the existence of a discrete Nrf2-independent molecular pathway starting at Keap1 engagement by electrophiles and culminating in selective inhibition of IκBζ translation. Defining the mechanistic details of this pathway will deepen the general understanding of immune regulation and will provide novel therapeutic strategies in autoimmune diseases driven by the IκBζ-IL-17 axis. We aim to uncover key members and mechanisms of this pathway using the following converging strategies: 1) define the mechanism of IκBζ inhibition by electrophilic stress at the level of Keap1 and 2) define the mechanism of translational regulation of Nfkbiz mRNA in conditions of electrophilic stress. Completion of the proposed Aims will lay the foundation for future detailed in vitro and in vivo studies of the novel regulator/regulators of the IκBζ activation program. Ultimately, we aim to study the role of the novel IκBζ regulators identified by this proposal in the context of an inflammatory condition such as psoriasis, which will be the subject of a future R01 application.

抽象的 亲电应激是由反应性硫醇基（-sh）的化合物引起的广泛现象 随着半胱氨酸保留在细胞蛋白内。我们发现由二甲基诱导的亲电应力反应 Itaconate（di）是代谢产物的衍生物，介导了强大但非常有选择性的抑制作用 免疫激活。在巨噬细胞中，DI治疗下调了一部分细胞因子的产生 IL-6或IL-12，但不影响其他细胞因子，例如TNF。我们发现这种选择性效果是通过 抑制NF-κB家族的转录因子IκBζ，通常在免疫激活过程中诱导。 IκBζ在几种重要情况下有选择地调节感染：（1）在巨噬细胞中，IκBζ调节 对Toll样受体刺激及其缺乏的继发转录反应导致产生缺陷 一部分细胞因子（例如IL-6和IL-12）的子集，而不是TNF； （2）在上皮细胞中，IκBζ是 对IL-17的转录响应； （3）在T细胞中，它是促进Th17的必不可少的转录因子 极化。重要的是，医学和人群遗传学研究已经鉴定了NFκBIZ（编码基因 IκBζ）是牛皮癣的主要易感基因座，是IL-17相关的自身免疫性条件。我们有 证明DI的体内给药完全可以改善小鼠模型中病理的发展 牛皮癣。因此，对IκBζ与亲电应力之间的联系有更深入的了解具有 发现新型治疗途径的强大潜力，用于治疗自身免疫性疾病，例如牛皮癣。 此外，尽管研究二极的细胞对亲电应力的反应是KEAP1/NRF2途径，但我们 表明DI对IκBζ的影响与NRF2无关。我们的初步数据表明存在 离散的NRF2独立的分子途径，从电力和keap1开始。 最终在选择性抑制IκBζ翻译方面。定义此途径的机械细节将 加深对免疫调节的一般理解，并将提供新颖的治疗策略 由IκBζ-IL-17轴驱动的自身免疫性疾病。我们旨在发现关键成员和机制 使用以下融合策略的这一途径：1）定义通过 KEAP1和2的电力应力）定义了NFKBIZ翻译调节的机制 在亲电应力条件下的mRNA。拟议目标的完成将为未来奠定基础 详细详细介绍了IκBζ激活程序的新调节剂/调节剂的体外研究和体内研究。最终，我们 旨在研究该提案在炎症的背景下确定的新型IκBζ调节剂的作用 牛皮癣等疾病将是未来R01应用程序的主题。