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，与高 发病率和死亡率的进展受到了 SSc 有效疗法的阻碍。 尽管大量证据表明免疫失调，但对其发病机制的了解仍不全面。 在 SSc 中，免疫系统影响成纤维细胞功能的机制尚不清楚。 本文提出了一种多方面的方法来阐明干扰素调节因子 7 (IRF7) 在真皮中的作用 成纤维细胞作为 SSc 免疫失调和纤维化之间的病理桥梁。 干扰素 (IFN) 基因表达特征是最突出的外周血细胞转录谱。 此外，我们的大规模基因表达研究已经确定了IRF7，它是细胞中的一个关键转录因子。 I 型 IFN 通路，作为皮肤和血液中 SSc 分子谱的最高预测上游调节因子， 我们最近发表的研究表明，IRF7 是 SSc 成纤维细胞的重要调节因子。 在 SSc 皮肤和移植的真皮成纤维细胞中上调和激活，I 型 IFN 上调 IRF7 IRF7 在成纤维细胞中的表达与 SMAD3 相互作用并增强 TGFβ 诱导的纤维化信号传导。 此外，在两种小鼠真皮纤维化模型中，整体 Irf7 敲低可减轻真皮纤维化。 最后，我们最近的初步数据表明成纤维细胞特异性 Irf7 敲低可能足以减弱 博来霉素诱导的真皮纤维化在此，我们发现 IRF7 将 I 型 IFN 途径与纤维化联系起来。 通过增强成纤维细胞中的 TGFβ 信号来响应，成纤维细胞是 SSc 中的主要效应细胞。 目标是阐明 I 型 IFN 诱导的 IRF7 上调在增强 TGFβ 经典作用中的作用 通过IRF7与真皮成纤维细胞中的SMAD3相互作用的途径将追求以下具体目标： 目标 1：确定小鼠真皮纤维化模型中 Irf7 耗竭对成纤维细胞的特异性贡献。 成纤维细胞特异性 Irf7 耗竭对博来霉素诱导的真皮纤维化和 Tsk1 真皮纤维化的影响 目标 2：阐明 IRF7 对 SMAD3 介导的功能影响。 转录活性和基因表达调控 具有 IRF7 过表达的人成纤维细胞系 表达和缺失将产生TGFβ介导的SMAD3转录靶点和基因 表达调控将通过 ChIP 测序和 RNA 测序来表征。 目标 3：描绘关系。 外周血细胞干扰素特征与终末器官水平 IRF7 上调之间的关系 SSc 患者外周血 IFN 特征与 IRF7 表达之间的关系。 将使用批量和单细胞 RNA 测序来表征皮肤组织和真皮成纤维细胞亚群。 总的来说，该提议可以阐明免疫失调导致 IRF7 的关键机制 激活增强了 SSc 中的纤维化反应，最终，这可以为识别更多疾病打开大门。 针对这种潜在破坏性疾病的有针对性和有效的治疗方案。