Interferon Regulatory Factor 7 Links Interferon Pathway Activation to the Exaggerates Fibrotic Response in Systemic Sclerosis

干扰素调节因子 7 将干扰素通路激活与系统性硬化症中过度的纤维化反应联系起来

• 批准号: 10682192
• 负责人: Shervin Assassi
• 金额: $ 22.49万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2028-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10682192
• 关键词: Address; Attenuated; Autoimmune; Autoimmune Diseases; Bleomycin; Blood; Blood Cells; CRISPR/Cas technology; Cell Line; ChIP-seq; Data; Dermal; Development; Disease; Effector Cell; Fibroblasts; Fibrosis; Gene Expression; Gene Expression Profile; Gene Expression Profiling; Gene Expression Regulation; Genetic Predisposition to Disease; Genetic Transcription; Goals; Human; Immune; Immune system; Immunity; In Vitro; Interferon Type I; Interferons; Knockout Mice; Link; Longitudinal cohort; MADH3 gene; Mediating; Modeling; Molecular; Molecular Profiling; Morbidity - disease rate; Mus; Organ; Pathogenesis; Pathologic; Pathway interactions; Patients; Publishing; RNA; Rheumatism; Role; Sampling; Scleroderma; Signal Transduction; Single Nucleotide Polymorphism; Skin; Skin Tissue; System; Systemic Scleroderma; Tissues; Transcript; Transforming Growth Factor beta; Up-Regulation; Work; conditional knockout; effective therapy; experimental study; in vivo; indium-bleomycin; insight; interferon regulatory factor-7; knock-down; mortality; mouse model; overexpression; peripheral blood; response; single-cell RNA sequencing; skin fibrosis; targeted treatment; transcription factor; transcriptome sequencing

Systemic sclerosis (SSc-scleroderma) is a multisystem autoimmune, fibrotic disease associated with high morbidity and mortality. Progress in the development of effective therapies for SSc has been hampered by a fragmented understanding of its pathogenesis. Although abundant evidence implicates dysregulated immunity in SSc, the mechanisms by which the immune system influences fibroblast function are not well-understood. We propose herein a multifaceted approach to elucidate the role of interferon regulatory factor 7 (IRF7) in dermal fibroblasts as a pathologic bridge between immune dysregulation and fibrosis in SSc. An interferon (IFN) gene expression signature is the most prominent peripheral blood cell transcript profile in SSc. Moreover, our large-scale gene expression studies have identified IRF7, a key transcription factor in the type I IFN pathway, as the top predicted upstream regulator of the SSc molecular profile in both skin and blood, as well as a prominent regulator of SSc fibroblasts. Our recently published work showed that IRF7 is significantly upregulated and activated in SSc skin and explanted dermal fibroblasts, and that type I IFN upregulates IRF7 expression in fibroblasts. IRF7 interacts with SMAD3 and potentiates TGFβ induced fibrosis signaling in fibroblasts. Moreover, global Irf7 knockdown attenuates dermal fibrosis in two murine dermal fibrosis models. Lastly, our recent preliminary data suggest fibroblast specific Irf7 knockdown might be sufficient for attenuating the bleomycin induced dermal fibrosis. Herein, we hypothesize that IRF7 links type I IFN pathway to the fibrotic response by potentiating the TGFβ signaling in fibroblasts which are the primary effector cells in SSc. Our primary goal is to elucidate the role of type I IFN induced IRF7 upregulation in potentiating the TGFβ canonical pathway via IRF7 interaction with SMAD3 in dermal fibroblasts. The following Specific Aims will be pursued: Aim 1: Define the fibroblast specific contribution of Irf7 depletion in murine dermal fibrosis models. The impact of fibroblast specific Irf7 depletion on dermal fibrosis in bleomycin induced and Tsk1 dermal fibrosis models will be investigated. Aim 2: Elucidate the functional effects of IRF7 on SMAD3 mediated transcriptional activity and gene expression regulation Human fibroblast cell lines with IRF7 over- expression and deletion will be generated and TGFβ-mediated SMAD3 transcriptional targets and gene expression regulation will be characterized by ChIP- and RNA-sequencing. Aim 3: Delineate the relationship between the peripheral blood cell interferon signature and IRF7 upregulation at the end-organ level in patients with SSc. The relationship between the peripheral blood IFN signature and IRF7 expression in SSc skin tissue and dermal fibroblast subpopulations will be characterized using bulk and single cell RNA sequencing. Cumulatively, this proposal can elucidate a key mechanism by which immune dysregulation leading to IRF7 activation potentiates the fibrotic response in SSc. Ultimately, this can open the door to identification of more targeted and effective treatment options for this potentially devastating disease.

系统性硬化症（Ssc-硬皮病）是一种多系统自身免疫性纤维化疾病， 发病率和死亡率。SSc有效治疗方法的开发进展受到阻碍， 对其发病机制的认识不完整。尽管大量证据表明免疫失调 在SSc中，免疫系统影响成纤维细胞功能的机制尚不清楚。我们 本文提出了一种多方面的方法来阐明干扰素调节因子7（IRF 7）在真皮中的作用， 成纤维细胞作为免疫失调和SSc纤维化之间的病理桥梁。 干扰素（IFN）基因表达特征是在哺乳动物中最突出的外周血细胞转录谱。 SSc.此外，我们的大规模基因表达研究已经确定了IRF 7，一个关键的转录因子， I型IFN途径，作为皮肤和血液中SSc分子谱的最高预测上游调节物， 也是SSc成纤维细胞的重要调节因子。我们最近发表的工作表明，IRF 7是显着的， 在SSc皮肤和干燥的真皮成纤维细胞中上调和激活，并且I型IFN上调IRF 7 在成纤维细胞中表达。IRF 7与SMAD 3相互作用并增强TGFβ诱导的纤维化信号传导 成纤维细胞此外，在两种鼠皮肤纤维化模型中，整体Irf 7敲低减弱皮肤纤维化。 最后，我们最近的初步数据表明，成纤维细胞特异性Irf 7敲低可能足以减弱 博莱霉素诱导皮肤纤维化。在此，我们假设IRF 7将I型IFN途径与纤维化细胞的增殖和分化联系起来。 通过增强成纤维细胞（SSc中的主要效应细胞）中的TGFβ信号传导来增强免疫应答。我们的首要 目的是阐明I型IFN诱导的IRF 7上调在增强TGFβ经典表达中的作用。 在真皮成纤维细胞中通过IRF 7与SMAD 3相互作用的信号通路。将追求以下具体目标： 目的1：确定小鼠真皮纤维化模型中Irf 7耗竭的成纤维细胞特异性贡献。的 成纤维细胞特异性Irf 7缺失对博莱霉素诱导和Tsk 1皮肤纤维化中皮肤纤维化的影响 将对模型进行研究。目的2：阐明IRF 7对SMAD 3介导的细胞凋亡的功能影响。 转录活性和基因表达调控-IRF 7过表达的人成纤维细胞系 表达和缺失将产生，TGFβ介导的SMAD 3转录靶点和基因 表达调控将通过ChIP和RNA测序来表征。目标3：描述关系 外周血细胞干扰素信号与终末器官水平IRF 7上调之间的关系 SSc患者SSc外周血IFN信号与IRF 7表达的关系 皮肤组织和真皮成纤维细胞亚群将使用批量和单细胞RNA测序来表征。 累积起来，这一建议可以阐明免疫失调导致IRF 7的关键机制。 活化增强了SSc中的纤维化反应。最终，这可以打开更多识别的大门， 有针对性的和有效的治疗选择，这种潜在的毁灭性疾病。