Reconstituting the oligogenic trait 'Eosinophilic myocarditis to heart disease' in Collaborative Cross lines to understand its genetic architecture

在协作交叉系中重建寡基因性状“嗜酸性心肌炎至心脏病”以了解其遗传结构

• 批准号: 10007207
• 负责人: Daniel R Prows
• 金额: $ 23.85万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10007207
• 关键词: A/J Mouse; Address; Adoptive Transfer; Affect; Alleles; Animal Model; Area; Autoimmune Diseases; B-Lymphocytes; Backcrossings; Breeding; Candidate Disease Gene; Cardiac; Cessation of life; Churg-Strauss Syndrome; Clinical; Code; Complex; Data Linkages; Diagnosis; Dilated Cardiomyopathy; Disease; Disseminated eosinophilic collagen disease; Distal; Eosinophilia; Female; Fibrosis; Functional disorder; Funding; Funding Agency; Generations; Genes; Genetic; Genetic Variation; Genome; Genomics; Genotype; Goals; Grant; Haplotypes; Heart; Heart Diseases; Heart failure; Heritability; Immune system; Inbred Strain; Inbreeding; Inflammatory Infiltrate; Knowledge; Link; Lung; Major Histocompatibility Complex; Maps; Modeling; Molecular; Morbidity - disease rate; Mus; Mutant Strains Mice; Myocarditis; Names; Oligogenic Traits; Organ; Partner in relationship; Pathologic; Pathology; Patients; Penetrance; Peripheral; Peripheral Blood Eosinophilia; Phenotype; Population; Procedures; Publishing; Quantitative Trait Loci; Recombinants; Reporting; Research; Research Design; Resolution; Role; SJL/J Mouse; Scheme; Site; Spleen; Splenocyte; Time; Untranslated RNA; Variant; Ventricular; Wegener' s Granulomatosis; causal variant; cohort; eosinophil; experience; genetic architecture; genetic element; genetic variant; genome sequencing; heart damage; high reward; high risk; identity by descent; immunoregulation; improved; interest; male; mortality; mouse model; mutant; mutant mouse model; offspring; outcome forecast; premature; reconstitution; success; tool; trait; whole genome

Abstract / Project Summary From a spontaneous founder mutant, we have established several lines of mice that naturally develop heart disease (HD), which rapidly progresses to heart failure and premature death. Characterization of affected mutants revealed eosinophilia in multiple organs, including the heart, lungs, and spleen. Affected mice develop eosinophilic myocarditis (EM) that leads to extensive fibrosis and right ventricular dilated cardiomyopathy, with most mice dying by ~15-weeks. Clinically, many of the pathologies in mutant mice coincide with those realized in patients diagnosed with hypereosinophilic syndrome (HES) or eosinophilic granulomatosis and polyangiitis (EGPA, aka Churg-Strauss Syndrome), two rare eosinophil-associated diseases with a worse prognosis when accompanied by HD. We have maintained the EM/HD trait on an inbred A/J strain background (i.e., A/JHD) for many generations, so we suspected that heritability of the mutant trait is controlled by a small set of genes. The EM/HD disease could also be transferred to irradiated A/J mice by adoptive transfer of splenocytes from affected mice, implicating a role for the immune system. Because little is known regarding the genes involved in most eosinophilic diseases, we sought to map EM/HD in this mutant. For linkage studies, we systematically backcrossed and intercrossed proven A/JHD mutant males (i.e. previously sired affected offspring) with 4 inbred strains and identified SJL/J (SJ) mice as the best strain–cross combination to reproduce EM/HD for mapping. Using QTL analysis of SJ-derived F2 and N2 populations, HD was mapped to 3 highly significant loci (named Emhd1-3 for ‘eosinophilic myocarditis to heart disease’). Linkage regions included a recessive variant on Chr5 (Emhd1) that is necessary but not sufficient for disease, and 2 separate dominant loci on Chr17 (Emhd2 and Emhd3). Recently, we found that using a 3-generation N2/F2 mating scheme with A/JHD and SJ breeders could further improve the rate of producing recombinants that developed HD. With this experience and knowledge gained from reconstituting EM/HD in several inbred strains, along with a more efficient N2/F2 breeding strategy, we now propose to recapitulate the oligogenic trait in select CC strains. Our working hypothesis is that the genetic diversity of CC lines will help refine linkage intervals, identify any additional QTLs and determine the importance of heterozygous regions (i.e., do they house a dominant variant?) to the trait. The primary goals of this grant are to validate QTLs and better understand the overall heritability. Specifically, we will reestablish EM/HD in recombinants generated from select CC lines that carry the desired strain alleles at critical sites of interest. All N2/F2 CC-recombinants will be phenotyped for EM/HD and an equal number of affected and unaffected CC-recombinants genotyped, and QTL and haplotype analyses performed. We expect the CC lines will instill the genetic diversity necessary to unambiguously identify and confirm all regions of importance to the trait and impart an understanding of the overall genetic architecture of EM/HD. This knowledge will provide a basis for hypothesis-driven studies designed to delineate the causal variants and their interactions.

摘要 /项目摘要 从赞助的创始人突变体中，我们建立了几种自然发展的小鼠 心脏病（HD）迅速发展为心力衰竭和过早死亡。受影响的表征 突变体揭示了多个器官，包括心脏，肺部和脾脏的嗜酸性粒细胞。受影响的小鼠发育 嗜酸性心肌炎（EM），可导致广泛的纤维化和右心室扩张性心肌病，并具有 大多数老鼠死于〜15周。临床上，突变小鼠中的许多病理与实现的病理相吻合 在被诊断患有低疾病综合征（HES）或嗜酸性肉芽肿病和多血管炎的患者中 （EGPA，又名Churg-Strauss综合征），两种罕见的嗜酸性粒细胞相关疾病，预后较差 伴随高清。我们已将EM/HD特征保留在近交的A/J菌株背景（即A/JHD）上 许多世代，因此我们怀疑突变性状的遗传力是由一小部分基因控制的。 EM/HD疾病也可以通过自适应从 影响小鼠，含义是免疫系统的作用。因为关于所涉及的基因知之甚少 在大多数嗜酸性疾病中，我们感觉到该突变体中的EM/HD映射。对于连锁研究，我们系统地 反向交叉和划线的经过验证的A/JHD突变雄性（即先前受生物影响的后代）与4个inbred 菌株并确定SJL/J（SJ）小鼠是最佳的应变 - 杂交组合，以繁殖EM/HD用于映射。 使用SJ衍生的F2和N2种群的QTL分析，将HD映射到3个非常重要的位置（命名 EMHD1-3用于“心脏病的嗜酸性心肌炎”）。链接区域包括CHR5上的隐性变体 （EMHD1）这是必要但不足以适合疾病，并且在Chr17上有2个独立的主要基因座（EMHD2和 EMHD3）。最近，我们发现使用A/JHD使用3代N2/F2交配方案，SJ育种者可以使用 进一步提高了产生HD的重组的速度。有了这种经验和知识 从几种近交菌株中重建EM/HD以及更有效的N2/F2育种策略中获得 现在，我们建议在某些CC菌株中概括寡聚性状。我们的工作假设是 CC线的遗传多样性将有助于完善链接间隔，确定任何其他QTL并确定 杂合区域的重要性（即，它们是否容纳了主要的变体？）。主要目标 这笔赠款是为了验证QTL并更好地了解总体遗传力。具体来说，我们将重建 由精选的CC线产生的重组者的EM/HD，这些CC线携带所需的应变等位基因在关键位置 兴趣。所有N2/F2 CC重组剂将用于EM/HD，并且受影响的数量相等 未受影响的CC - 成分基因分型，QTL和单倍型分析进行了。我们期望CC线路 将灌输明确识别和确认所有重要区域所必需的遗传多样性 特质并赋予对EM/HD的整体遗传结构的理解。这些知识将提供 假设驱动的研究的基础旨在描述因果变体及其相互作用。