Elucidating the Role of Dynamic X-Chromosome Inactivation Maintenance in the Pathogenesis of Systemic Sclerosis

阐明动态 X 染色体失活维持在系统性硬化症发病机制中的作用

• 批准号: 10511513
• 负责人: Montserrat C Anguera
• 金额: $ 21.45万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-12 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10511513
• 关键词: Affect; Attention; Autoimmune Diseases; Bleomycin; CD3 Antigens; CD8-Positive T-Lymphocytes; CREST Syndrome; CXCR3 gene; Candidate Disease Gene; Cell physiology; Cells; Cicatrix; Collagen; Cutaneous; Cytology; Data; Defect; Development; Disease; Embryonic Development; Epigenetic Process; Exhibits; FOXP3 gene; Female; Fibrosis; Fluorescent in Situ Hybridization; Future; Gene Dosage; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Gene Silencing; Genes; Genetic Risk; Genetic Transcription; Goals; Harvest; Heterochromatin; Hormonal; Human; IL13RA1 gene; Immune; Immune system; Immunofluorescence Immunologic; Impairment; In Vitro; Inflammation; Investigation; Knockout Mice; Laboratories; Link; Lupus; Lymphocyte; Maintenance; Mediating; Modeling; Modification; Molecular; Monozygotic twins; Morbidity - disease rate; Mus; Nuclear; Organ; Outcome; Pathogenesis; Pathogenicity; Pathology; Patients; Pattern; Peripheral; Predisposition; Process; Pulmonary Fibrosis; RNA; RNA Interference; Rest; Role; Scleroderma; Serum; Sex Bias; Skin; Skin Tissue; Somatic Cell; Splenic Tissue; Structure of parenchyma of lung; Systemic Scleroderma; T-Lymphocyte; T-Lymphocyte Subsets; TIMP1 gene; TNFSF5 gene; Testing; Therapeutic; Therapeutic Intervention; Tissues; Untranslated RNA; Vascular Diseases; Wild Type Mouse; Woman; Work; X Chromosome; X Inactivation; base; biological sex; cell type; cellular imaging; comparative; epigenetic regulation; epigenetic silencing; histone modification; immune function; improved; insight; male; men; mortality; mouse model; novel; novel therapeutics; overexpression; peripheral blood; prevent; programs; recruit; risk variant; single molecule; skin fibrosis; subcutaneous; systemic autoimmune disease; systemic autoimmunity; transcriptome; transcriptome sequencing; transcriptomics

Project Summary/Abstract: Systemic sclerosis (SSc) is a systemic autoimmune disease that predominantly affects women and is associated with significant morbidity and mortality due to fibrosis of the skin and internal organs. The molecular origin of this striking female bias and its relationship to core aspects of the pathogenesis of SSc, including immune dysregu- lation, multiorgan fibrosis, and vasculopathy, remains unclear. While there are known genetic risk variants asso- ciated with SSc, the low monozygotic twin concordance rate has prompted investigation into the role of epige- netic dysregulation in its pathogenesis. Importantly, the X-chromosome contains several proinflammatory and profibrotic genes, and their appropriate expression in females is epigenetically regulated in part through X-chro- mosome inactivation (XCI), a female-specific epigenetic mechanism that silences one of the two X chromosomes in order to equalize X-linked gene dosage between XX females and XY males. XCI is maintained in somatic cells by a variety of epigenetic modifications that are enriched on the inactive X chromosome (Xi), including the long noncoding RNA XIST and additional heterochromatic histone modifications. We recently discovered that XCI maintenance in T-cells from both humans and mice is “dynamic.” In “dynamic XCI maintenance”, XIST RNA and heterochromatic marks are cytologically absent from the Xi in resting T-cells and subsequently relocalize to the Xi upon in vitro cellular activation. We have found that dynamic XCI maintenance is impaired in T-cells from women with lupus, another female-biased autoimmune disease, and is associated with aberrant X-linked gene expression from the Xi. Based on the well-established role of T-cells in SSc-mediated pathology, the number of X-linked proinflammatory and profibrotic genes, the aberrantly increased expression of many of these genes in SSc T-cells, and our preliminary data, we hypothesize that impaired dynamic XCI maintenance in T-cells is a pathogenic mechanism in SSc that accordingly contributes to the observed female bias. In Aim 1, we will use single cell imaging to determine whether XCI maintenance is impaired in T-cells from females with SSc. We will couple these analyses with transcriptomic studies to determine the contribution of the Xi to the observed X-linked gene expression profile. In Aim 2, we will induce scleroderma-like disease in a novel mouse model of impaired XCI maintenance to determine how impaired XCI maintenance in T-cells impacts T-cell-specific transcriptional programs conferring susceptibility to fibrosis in SSc-relevant organs. Collectively, this work has the potential to identify a novel epigenetic mechanism of female bias in SSc and will simultaneously identify which X-linked genes become aberrantly expressed in T-cells during the development of fibrotic disease. These findings will improve our understanding of how biological sex contributes to the pathogenesis of SSc and related female- biased autoimmune disease and may enable the eventual discovery of new therapies for SSc.

项目概要/摘要： 系统性硬化症（SSc）是一种全身性自身免疫性疾病，主要影响女性， 由于皮肤和内部器官的纤维化，具有显著的发病率和死亡率。这种现象的分子起源 显著的女性偏见及其与SSc发病机制核心方面的关系，包括免疫失调， 炎症、多器官纤维化和血管病变仍不清楚。虽然有已知的遗传风险变体阿索 与SSc相关，单卵双胞胎的低一致率促使人们研究表观遗传学的作用， 在其发病机制中存在遗传调节障碍。重要的是，X染色体含有几种促炎和 促纤维化基因，其在女性中的适当表达部分通过X染色体的表观遗传调节。 mosome失活（XCI），一种女性特有的表观遗传机制，使两条X染色体中的一条沉默 以平衡XX女性和XY男性之间的X连锁基因剂量。XCI维持在体细胞中 通过在失活X染色体（Xi）上富集的各种表观遗传修饰，包括长 非编码RNA XIST和另外的异染色质组蛋白修饰。我们最近发现XCI 在来自人和小鼠的T细胞中的维持是“动态的”。在“动态XCI维持”中，XIST RNA和 异染色质标记在细胞学上不存在于静息T细胞中的Xi中，随后重新定位于 Xi在体外细胞活化后。我们已经发现，动态XCI维持在T细胞中受损， 狼疮是另一种女性偏好的自身免疫性疾病，与异常的X连锁基因有关。 来自Xi的表情基于T细胞在SSC介导的病理学中的明确作用， X连锁的促炎和促纤维化基因，这些基因中的许多基因在乳腺癌中的表达异常增加。 SSc T细胞，以及我们的初步数据，我们假设T细胞中受损的动态XCI维持是一种 SSc的致病机制，因此有助于观察到的女性偏见。在目标1中，我们将使用 单细胞成像以确定来自患有SSc的雌性的T细胞中XCI维持是否受损。我们将 将这些分析与转录组学研究相结合，以确定Xi对所观察到的X连锁遗传的贡献。 基因表达谱在目标2中，我们将在一种新的受损小鼠模型中诱导硬皮病样疾病。 XCI维持以确定T细胞中受损的XCI维持如何影响T细胞特异性转录调控。 在Ssc相关器官中赋予纤维化易感性的程序。总的来说，这项工作有可能 确定SSc中女性偏好一种新的表观遗传机制，并将同时确定哪些X连锁 在纤维化疾病的发展过程中，基因在T细胞中异常表达。这些发现将 提高我们对生物性别如何有助于SSc和相关女性发病机制的理解， 偏见的自身免疫性疾病，并可能最终发现新的治疗SSc。