Gene regulation from the inactive X in activated B cells

激活 B 细胞中非活性 X 的基因调控

基本信息

批准号：
10397666
负责人：
Montserrat C Anguera
金额：
$ 50.57万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-06-01 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10397666
关键词：
Alleles Amino Acids Antibodies Autoimmune Autoimmune Diseases Autoimmunity B-Cell Activation B-Lymphocytes Binding CXCR3 gene ChIP-seq Chromatin Chromosomes Cre lox recombination system DNA Data Disease Exhibits Failure Female Foundations Gene Dosage Gene Duplication Gene Expression Gene Expression Regulation Gene Silencing Genes Genetic Genetic Transcription Heterochromatin Human Hybrids Immune Immunity Impairment Knowledge Lamin Type B Lead Link Location Lupus Lymphocyte Mature B-Lymphocyte Mediating Modeling Modification Molecular Mus Nuclear Patients Pattern Play Predisposition Process Proteins Publishing RNA Research Proposals Rest Role Sex Chromatin Somatic Cell Structural Protein Suggestion Testing Transcript Untranslated RNA Up-Regulation Work X Chromosome X Inactivation YY1 Transcription Factor Zinc Fingers base capture hybridization analysis of RNA targets cohesin cohesion condensin conditional knockout density dosage ds-DNA experimental study gene repression innovation insight male mouse model novel overexpression prevent transcriptome sequencing

项目摘要

Project Summary The X-chromosome is enriched with immunity-related genes, therefore X-linked genes need to be regulated to prevent abnormal expression. Females use X-chromosome Inactivation (XCI) to equalize X-linked gene expression, where one X maintained transcriptionally silent by continuous expression of the long noncoding RNA Xist and enrichment of heterochromatin modifications. We have recently discovered that female lymphocytes have a unique and dynamic mechanism to maintain XCI, unlike other somatic cells. Resting mature B cells lack Xist RNA and heterochromatin marks on the Xi, and these modifications return to the Xi through a YY1-mediated mechanism upon stimulation. Our in-press work indicates that preventing Xist RNA localization to the Xi by conditional knock-out of YY1 impairs heterochromatin enrichment on the Xi, and increases X-linked expression. In preliminary work, we found that B-cell specific deletion of one Xist allele (mb1CRE XistCKO/+) dramatically reduced Xist localization patterns over the Xi, reduced heterochromatin enrichment, and increased expression of specific X-linked genes. Moreover, this increase in X-linked gene expression was accompanied by increased antibodies to double-stranded DNA, a hallmark of autoimmunity. We hypothesize that Xist RNA localization to Xi is required to keep Xi at the nuclear periphery to maintain transcriptional repression in activated B cells, and that failure to localize Xist RNA disrupts Xi nuclear organization and perturbs X-linked gene expression, with consequent predisposition to autoimmunity. We will test our hypothesis with the following aims: (1) Do temporal and sequence-specific occupancy of YY1, Xist RNA, and heterochromatin marks on the Xi maintain transcriptional repression in activated splenic B cells? (2) Do chromosome structural proteins cooperate with YY1 to localize Xist RNA within Xi territory at the nuclear periphery for transcriptional repression in activated splenic B cells? (3) Are Cxcr3, Itm2a, Syn1 and Cfp overexpressed in lupus mouse models and does increased dosage predispose to autoimmunity? IMPACT: The results from these experiments will yield fundamental insight about the lymphocyte-specific mechanisms that regulate expression from the Xi, and will advance our understanding of the female-bias underlying B cell mediated autoimmune disorders.

项目摘要 X染色体富含免疫相关基因，因此需要调节X连锁基因预防异常表达。女性使用X染色体灭活（XCI）来均衡X连锁基因表达式，其中一个X通过连续表达长的不编码来保持转录静音 RNA xist和异染色质修饰的富集。我们最近发现女性与其他体细胞不同，淋巴细胞具有保持XCI的独特而动态的机制。休息成熟的B细胞在XI上缺乏Xist RNA和异染色质标记，这些修饰返回到XI 通过刺激后的YY1介导的机制。我们的压力工作表明防止Xist RNA 通过YY1的条件敲除将XI的定位损害XI上的异染色质富集，并且增加X连锁表达。在初步工作中，我们发现一个Xist等位基因的B细胞特定缺失（MB1CRE XISTCKO/+）XI上的XIST定位模式大大降低，减少了异染色质富集，并增加了特定X连锁基因的表达。此外，X连锁基因的增加表达伴随着对双链DNA的抗体增加，这是自身免疫性的标志。我们假设需要将XIST RNA定位到XI需要保持XI保持核外围以维持活化的B细胞中的转录抑制作用，并且未能定位XIST RNA会破坏XI核组织和伴随X连锁基因表达，因此自身免疫性倾向。我们将用以下目的测试我们的假设：（1）执行yy1的时间和序列特异性占用率 XI上的RNA和异染色质标记保持活化的脾脏B细胞中的转录抑制？（2）染色体结构蛋白与YY1合作以将XIST RNA定位在XI领域的核激活的脾脏B细胞中转录抑制的外围？（3）是CXCR3，ITM2A，SYN1和CFP 在狼疮小鼠模型中过表达，并且增加剂量易于自身免疫性吗？影响：这些实验的结果将产生有关淋巴细胞特异性机制的基本见解。调节XI的表达，并将提高我们对女性偏见B细胞的理解介导的自身免疫性疾病。