Link between Retroelements, Ro and Interferon Biology in Lupus

狼疮中逆转录元素、Ro 和干扰素生物学之间的联系

• 批准号: 9378686
• 负责人: Keith B. Elkon
• 金额: $ 23.23万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-21 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9378686
• 关键词: Adjuvant; Antigen-Antibody Complex; Attenuated; Autoantibodies; Autoantigens; Autoimmune Diseases; Autoimmunity; B-Lymphocytes; Binding; Biology; Boron; Cell Line; Cell surface; Cells; Clinical; Congenital Heart Block; Cutaneous Lupus Erythematosus; DNA Damage; Data; Dendritic Cells; Disease; Disease susceptibility; Elements; Embryo; Employee Strikes; Environmental Risk Factor; Enzymes; Estrogens; Exanthema; Female; Fibroblasts; Genes; Genetic; Genetic Transcription; Hormones; Human; Immune signaling; Immunoprecipitation; In Vitro; Inbred MRL lpr Mice; Inflammation; Inflammatory; Interferon Type I; Interferon-beta; Interferons; Knockout Mice; Lead; Learning; Ligands; Link; Lupus; Mediating; Methods; Methylation; Methyltransferase; Mouse Strains; Mus; Mutation; Natural Immunity; Nucleic Acids; Pathogenesis; Pathway interactions; Patients; Photosensitivity; Prevention; Proteins; RNA; RNA Binding; Reporting; Research; Research Personnel; Retroelements; Retrotransposon; Role; SS-A antibodies; Short Interspersed Nucleotide Elements; Signal Pathway; Signal Transduction; Sjogren' s Syndrome; Skin; Stimulus; Systemic Lupus Erythematosus; TREX1 gene; Techniques; Testing; To autoantigen; Transcript; UV induced; Ultraviolet B Radiation; Ultraviolet Rays; Untranslated RNA; Work; base; cytokine; experience; experimental study; in vivo; in vivo Model; insight; knock-down; lupus-like; male; new technology; overexpression; programs; receptor; response; sensor; targeted treatment; therapy design; ultraviolet irradiation

Project Summary A variety of nucleic acid ligands have been implicated in the striking Type I Interferon (IFN-I) response observed in lupus and related diseases but which ligands and receptors drive disease are unclear. Amongst putative ligands are retroelements (RE), one class of which, the SINES, was recently shown to bind to the autoantigen, Ro60. Tying this observation to the surprising finding that Ro60 deficient mice get lupus, we will test an explanation for lupus pathogenesis that links disease susceptibility to Ro function. To test the hypothesis that an excess of SINES relative to Ro induces IFN-I and a lupus like disease, we propose: In Aim 1, we will identify the small non coding RNAs that bind to murine Ro60 and we will define the Ro recognition motifs (RRM) using a highly sensitive and specific immunoprecipitation technique called iCLIP. In addition, we will generate mouse embryonic fibroblasts (MEFS) that are deficient in Ro and in one of the key RNA sensors called RIG-I or MDA5 that stimulate IFN-I signaling. These experiments will identify the RNA ligand, motif(s) and corresponding RNA sensors responsible for cell autonomous IFN-I stimulation. In the second Aim, we will ask how Ro60 and RNA binding elements are regulated, in response to lupus relevant environmental triggers. First, using cell based approaches and the MEFS generated in Aim 1, we will de-repress SINES by inhibiting the methylase that is responsible for suppression of SINE transcription in mice. Next, we will expose cells to UVB radiation that has been shown to result in increased SINE expression. Finally, as prompted by our preliminary data, we will examine whether Estrogen (E2) upregulates SINES or reduces Ro expression. The experiments are expected to validate SINES as the key RNA ligand that provokes cell intrinsic IFN-I stimulation and test whether lupus related environmental factors alter expression of the RNA or protein. Following these experiments, we will examine the same environmental factors in Ro deficient mice. Since Ro deficient mice develop a lupus like autoimmunity for which there is no current explanation, we will explore the hypothesis that, when Ro is limiting or SINES are overexpressed, SINES stimulate IFN-I which in turn leads to a lupus like disease in the appropriate genetic background. We expect that UV light will increase IFN-I expression in the skin and that this finding will be markedly exacerbated in Ro deficient female mice. Anti-Ro antibodies are usually the first autoantibody to develop in human lupus – many years before the onset of clinical disease. They are also associated with congenital heart block and UV mediated skin rashes. Through understanding the roles of SINE elements and Ro in triggering specific IFN pathways in lupus, we should be able to explore the pathobiology with much greater insight in human SLE and devise approaches to targeted prevention and treatment.

项目概要 多种核酸配体与引人注目的 I 型干扰素 (IFN-I) 反应有关 在狼疮和相关疾病中观察到，但其中哪些配体和受体驱动疾病尚不清楚。 推定的配体是逆转录元件（RE），其中一类 SINES 最近被证明可以与 将这一观察结果与 Ro60 缺陷小鼠罹患狼疮这一令人惊讶的发现联系起来，我们将 测试将疾病易感性与 Ro 功能联系起来的狼疮发病机制的解释。 假设 SINES 相对于 Ro 过量会诱发 IFN-I 和狼疮样疾病，我们提出： 在目标 1 中，我们将鉴定与鼠 Ro60 结合的小非编码 RNA，并定义 Ro 使用称为 iCLIP 的高度灵敏和特异性免疫沉淀技术进行识别基序 (RRM)。 此外，我们将生成缺乏 Ro 和关键基因之一的小鼠胚胎成纤维细胞 (MEFS) RNA 称为 RIG-I 或 MDA5，可刺激 IFN-I 信号传导。这些实验将鉴定 RNA。 配体、基序和相应的 RNA 传感器负责细胞自主 IFN-I 刺激。 在第二个目标中，我们将询问 Ro60 和 RNA 结合元件是如何调节的，以响应 首先，使用基于细胞的方法和目标 1 中生成的 MEFS， 我们将通过抑制负责抑制 SINE 转录的甲基化酶来去抑制 SINES 接下来，我们将细胞暴露于 UVB 辐射，该辐射已被证明会导致 SINE 增加。 最后，根据我们的初步数据，我们将检查雌激素 (E2) 是否上调。 SINES 或降低 Ro 表达 该实验预计将验证 SINES 作为关键的 RNA 配体。 激发细胞内在 IFN-I 刺激并测试狼疮相关环境因素是否改变 在这些实验之后，我们将检查 Ro 中的相同环境因素。 由于Ro缺陷小鼠会产生类似狼疮的自身免疫，而目前尚无针对该自身免疫的治疗。 解释中，我们将探讨以下假设：当 Ro 受到限制或 SINES 过度表达时，SINES 我们预计，刺激 IFN-I 会导致适当遗传背景下的狼疮样疾病。 紫外线会增加皮肤中 IFN-I 的表达，并且这一发现在 Ro 中会明显加剧 缺乏的雌性小鼠。 抗 Ro 抗体通常是人类狼疮中产生的第一个自身抗体 - 早很多年 它们还与先天性心脏病和紫外线介导的皮肤有关。 通过了解 SINE 元素和 Ro 在触发狼疮中特定 IFN 通路中的作用， 我们应该能够更深入地探索人类 SLE 的病理学并设计方法 才能有针对性地预防和治疗。