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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，防止异常表达。女性使用X染色体失活（XCI）来平衡X连锁基因表达，其中一个X通过长非编码区的连续表达而保持转录沉默。 RNA Xist和异染色质修饰的富集。我们最近发现，与其他体细胞不同，淋巴细胞具有独特的动态机制来维持XCI。休息成熟的B细胞缺乏Xist RNA和Xi上的异染色质标记，这些修饰返回Xi 通过YY 1介导的机制。我们的研究表明，阻止Xist RNA 通过YY 1的条件性敲除定位于Xi损害Xi上的异染色质富集，和增加X连锁表达。在初步工作中，我们发现一个Xist等位基因的B细胞特异性缺失，（mb 1CRE XistCKO/+）极大地减少了Xist在XI上的定位模式，减少了异染色质富集和增加特定X连锁基因的表达。此外，X连锁基因的增加表达伴随着双链DNA抗体的增加，这是自身免疫的标志。我们假设Xist RNA定位于Xi是将Xi保持在核外围以维持Xist RNA在细胞核中的表达所必需的。在活化的B细胞中转录抑制，并且未能定位Xist RNA破坏了Xi核组织和干扰X连锁的基因表达，从而倾向于自身免疫。我们将我们的假设是：（1）YY 1，Xist的时间和序列特异性占据是否 RNA和XI上的异染色质标记维持激活的脾B细胞中的转录抑制？（二）染色体结构蛋白是否与YY 1合作将Xist RNA定位在细胞核的Xi区域内外周活化脾B细胞转录抑制？(3)是Cxcr 3、Itm 2a、Syn 1和Cfp 在狼疮小鼠模型中过度表达，增加剂量是否易导致自身免疫？影响：The 这些实验的结果将产生关于淋巴细胞特异性机制的基本见解，调节Xi的表达，并将促进我们对B细胞雌性偏好的理解介导的自身免疫性疾病。