A role for endogenous retroelements in Aicardi-Goutieres Syndrome

内源性逆转录因子在 Aicardi-Goutieres 综合征中的作用

基本信息

批准号：
9296176
负责人：
JOHN Lawrence GOODIER
金额：
$ 20.43万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-14 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9296176
关键词：
17 year old ADAR1 Address Affect Algorithmic Analysis Amyotrophic Lateral Sclerosis Antigens Autoantibodies Autoimmune Process Awareness Basal Ganglia Bioinformatics Biological Assay Blood Brain Calcium Cause of Death Cell Line Cells Cerebrospinal Fluid Cessation of life Childhood Complementary DNA Crows DNA DNA Sequencing Facility Data Deposition Disease Disease Progression Electronic Mail Elements Embryonic Development Encephalopathies Endogenous Retroviruses Enzyme-Linked Immunosorbent Assay Fish Proteins Future Gene Proteins Genes Genetic Transcription Genome Genomics Grant High-Throughput Nucleotide Sequencing Human Human Genome Immune response Immune system Immunology Impairment Individual Infection Inflammatory Innate Immune System Insertion Mutation Interferon Type I Interferons Investigation Laboratories Laboratory Study Leukocytes Life Light Link Malignant Neoplasms Mentors Metabolism Molecular Profiling Multiple Sclerosis Mus Mutation Nervous System Trauma Neuraxis Neurons Nucleic Acids Paste substance Pathology Patients Phenotype Postdoctoral Fellow Process Protein Analysis Proteins Protocols documentation Pseudogenes RNA RNA analysis RNA-Directed DNA Polymerase Recruitment Activity Relaxation Research Research Personnel Retroelements Retrotransposition Retrotransposon Retroviridae Reverse Transcription Rheumatism Role Sampling Serum Severities Signal Transduction Skin Somatic Cell Source Systemic Lupus Erythematosus TREX1 gene Teleconferences Testing Tissues Transgenes Variant Work base brain dysfunction brain tissue cell type cohort early childhood early onset experience functional loss human DNA immunocytochemistry in vivo insight interest leukodystrophy mouse model next generation sequencing novel peripheral blood protein expression pseudotoxoplasmosis syndrome public health relevance response skin lesion systemic autoimmune disease transcriptome sequencing transposon/insertion element treatment strategy

项目摘要

DESCRIPTION (provided by applicant): A role for endogenous retroelements in Aicardi-Goutières syndrome Aicardi-Goutières syndrome (AGS) is a severe Mendelian inflammatory disorder that affects particularly the brain and frequently causes death in childhood. The disease is characterized by progressive encephalopathy, psychomotor regression, and lesions of the skin, together with increased levels of Type I interferon in the cerebrospinal fluid and serum, and induction of interferon-stimulated genes detectable in peripheral blood. Causative mutations have been identified in seven genes, TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 and IFIH1, with variation in the severity of their associated phenotypes. The protein products of these genes are involved in RNA metabolism or signaling, and have also been linked with suppression of infecting retroviruses and/or endogenous retrotransposons. This study is based on the hypothesis that functional loss of an AGS-associated gene alters the normal metabolism of retrotransposon RNA or its reverse-transcribed cDNA, triggering an interferon response and AGS. Retrotransposons are mobile DNA elements that duplicate themselves by a "copy and paste" mechanism using an RNA intermediate. Endogenous retroviruses (HERVs) comprise 8% of the human genome. Although no HERVs capable of replication have been identified, ongoing HERV expression has been implicated in several disease conditions, including multiple sclerosis, amyotrophic lateral sclerosis, and autoimmune rheumatic disease. LINE1 (L1) retrotransposons occupy 17% of human DNA, although it is believed that only about 100 remain competent for retrotransposition in any individual. L1 retrotransposition has also been responsible for the insertion of over a million non-autonomous Alu retrotransposons and thousands of processed pseudogenes. The cell has evolved defenses restricting retrotransposition, which are occasionally relaxed in certain somatic cell types, notably neuronal cells in the human brain. We predict relaxation of retroelement expression in AGS patients. Using RNA analyses, immunocytochemistry, and functional assays for reverse transcriptase activity, we will examine brain tissue, blood, sera, and derived cell lines from AGS patients to ascertain if retroelement RNA or protein expression is elevated in the disease state. We will determine if de novo L1 and Alu insertion numbers are increased in tissues of AGS patients using high-throughput sequencing protocols. The question of whether L1 expression can induce an interferon response will be addressed using a mouse model harboring an inducible L1 transgene. Finally, we will develop ELISA assays to ascertain if sera from AGS patients contain autoantibodies directed against retroelement proteins. This research should shed new light on a devastating childhood disease and suggest future strategies for treatment. Furthermore, new insights into the interaction of the intrinsic immune system of the cell and endogenous retroelements will be gained.

描述（由申请人提供）：内源性逆转录因子在 Aicardi-Goutières 综合征中的作用 Aicardi-Goutières 综合征 (AGS) 是一种严重的孟德尔炎症性疾病，特别影响大脑并经常导致儿童死亡。该疾病的特征是进行性脑病，精神运动退化和皮肤损伤，以及脑脊液和血清中 I 型干扰素水平升高，以及外周血中可检测到的干扰素刺激基因的诱导已在七个基因中发现，即 TREX1、RNASEH2A、RNASEH2B、RNASEH2C、SAMHD1、ADAR1 和 IFIH1，其相关表型的严重程度存在差异。参与 RNA 代谢或信号传导，并且还与感染逆转录病毒和/或内源逆转录转座子的抑制有关。假设 AGS 相关基因的功能丧失会改变逆转录转座子 RNA 或其逆转录 cDNA 的正常代谢，从而引发干扰素反应，而逆转录转座子是可移动的 DNA 元件，可使用 RNA 通过“复制和粘贴”机制进行自我复制。内源性逆转录病毒 (HERV) 占人类基因组的 8%，尽管尚未发现能够复制的 HERV，但持续的 HERV 表达与多种疾病有关，包括多种疾病。硬化症、肌萎缩性脊髓侧索硬化症和自身免疫性风湿病的 LINE1 (L1) 逆转录转座子占据了人类 DNA 的 17%，尽管据信在任何个体中只有大约 100 个具有逆转录转座能力，这也是导致过度插入的原因。一百万个非自主 Alu 逆转录转座子和数千个经过加工的假基因细胞已经进化出限制逆转录转座的防御，这些防御有时会在某些情况下放松。我们将使用 RNA 分析、免疫细胞化学和逆转录酶活性功能分析来预测 AGS 患者的体细胞类型，特别是人脑中的神经细胞。我们将使用高通量测序方案确定 AGS 患者组织中的 de novo L1 和 Alu 插入数量是否增加。 L1 表达是否可以诱导干扰素反应的问题将使用含有诱导型 L1 转基因的小鼠模型来解决。最后，我们将开发 ELISA 测定法来确定 AGS 患者的血清是否含有针对逆转录因子蛋白的自身抗体。此外，还将获得关于细胞内在免疫系统和内源性逆转录因子相互作用的新见解。