Molecular Pathphysiology of FSHD muscular dystrophy via genome-wide approaches

通过全基因组方法研究 FSHD 肌营养不良症的分子病理生理学

• 批准号: 7569419
• 负责人: YI-WEN CHEN
• 金额: $ 34.98万
• 依托单位: CHILDREN'S RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-15 至 2012-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7569419
• 关键词: 4q35; Adult; Affect; Age; Animal Model; Anterior; Apoptosis; Appearance; Belgium; Binding; Binding Sites; Biochemical; Biological Assay; Biopsy; Candidate Disease Gene; Cells; Chromosomes; Clinical; Computer software; Consensus; Creatine Kinase; D4Z4; Data; Dermatomyositis; Development; Disease; Disease model; Doxycycline; Duchenne muscular dystrophy; EMSA; Embryonic Development; Embryonic and Fetal Development; Evaluation; Face; Facioscapulohumeral Muscular Dystrophy; Fibroblasts; Functional disorder; Future; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic; Genetic Transcription; Genome; Goals; Hindlimb; Homeobox; Homeostasis; Homologous Gene; In Vitro; Inflammation; Inherited; Life; Limb Development; Limb structure; Location; Long-Term Effects; Lower Extremity; Luciferases; Mediating; Messenger RNA; Modeling; Molecular; Molecular Profiling; Molecular Target; Monitor; Mus; Muscle; Muscle Fibers; Muscle Weakness; Muscular Atrophy; Muscular Dystrophies; Mutagenesis; Mutation; Myoblasts; Myopathy; Natural regeneration; Neuromuscular Diseases; Onset of illness; Oxidative Stress; Pathogenesis; Pathway interactions; Patients; Phenotype; Phosphotransferases; Play; Predisposition; Principal Investigator; Process; Promoter Regions; Reporter; Reporter Genes; Research; Research Personnel; Reverse Transcriptase Polymerase Chain Reaction; Role; Series; Serum; Shoulder; Siblings; Site; Skeletal Muscle; Spinal; Staging; Testing; Tetanus Helper Peptide; Tetracyclines; Time; Tin; Transgenic Mice; Transgenic Model; Transgenic Organisms; Triceps Brachii Muscle; Ubiquitin; Universities; Up-Regulation; Upper arm; base; chromatin immunoprecipitation; derepression; disease phenotype; expression vector; fusion gene; gene function; gene induction; gene interaction; genome-wide; homeobox protein PITX1; homeodomain; in vivo; injured; mouse genome; mouse model; multicatalytic endopeptidase complex; postnatal; programs; promoter; research study; response; sex; skeletal muscle wasting; transcription factor; transgene expression; vector; wasting

DESCRIPTION (provided by applicant): Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscle disorder that is characterized by the progressive weakness and wasting of the muscles from face, upper-arm and shoulder girdle to lower limb. While there is consensus that FSHD is a disorder of transcription and gene regulation, the molecular pathways leading to muscular dystrophy and other unique clinical features of the disease are far from clear. Our preliminary study of whole genome profiles of 125 muscle biopsies representing 12 neuromuscular disorders showed that paired-like homeodomain transcription factor 1 (PITX1) gene was specifically up-regulated in FSHD patients. The significant PITX1 over-expression we observed in FSHD can not be due to inflammation, degeneration/ regeneration, or other "dystrophic" changes in muscle, as no other muscle disease (including juvenile dermatomyositis, Duchenne dystrophy, and others) showed up- regulation. Based on our extensive preliminary data both in vitro and in vivo, we present a model where over-expression of PITX1 in adult muscle invokes key muscle atrophy pathways, and, further, that PITX1 is regulated by DUX4 expression. The goal of this current proposal is to further develop our pathophysiological model to show direct relationships between 4q35 deletions, DUX4, and PITX1. The proposed research relies heavily on temporal series, conducted both in vivo and in vitro. Gene/gene interactions will also be determined. In aim 1, we propose to determine if Pitxl is a direct target of DUX4. We will determine whether a putative DUX4 binding site in the promoter region of Pitxl is functional, and whether it is specifically and directly regulated by DUX4. Additional DUX4 targets will be identified by temporal profiling. Interaction between DUX4 and potential target genes will be determined. In aim 2, we propose to generate and characterize a conditional muscle-specific Pitxl transgenic mouse model. The phenotype will be evaluated for changes in various clinical, functional, biochemical, molecular, and histological parameters. The phenotype of myoblasts, including appearance, proliferation, differentiation and susceptibility to oxidative stress, will also be evaluated. In addition, we will determine whether the disease phenotype is reversible. In aim 3, we will define molecular transcriptional pathways downstream of Pitxl expression using the Pitxl transgenic mouse. Temporal expression profiling will be performed to construct the pathways regulated by Pitxl. Interactions between Pitxl and potential regulatory targets of Pitxl will be further studied. Our preliminary data showed that disease-specific up-regulation of DUX4 and Pitxl and downstream changes of genes involved in muscle wasting might be involved in the pathophysiology of FSHD. The proposed research will identify key players in the pathological cascades of FSHD and define the interactions among them, which could potentially be used for developing treatments of the disease.

描述（由申请人提供）：面肩肱型肌营养不良症（FSHD）是一种常染色体显性肌肉疾病，其特征是从面部、上臂和肩带到下肢的肌肉进行性无力和萎缩。虽然有共识认为FSHD是一种转录和基因调控障碍，但导致肌营养不良症的分子途径和该疾病的其他独特临床特征还远不清楚。我们对代表12种神经肌肉疾病的125份肌肉活检组织的全基因组图谱的初步研究表明，FSHD患者的配对样同源结构域转录因子1（PITX 1）基因特异性上调。我们在FSHD中观察到的显著PITX 1过表达可能不是由于肌肉中的炎症、变性/再生或其他“营养不良”变化，因为没有其他肌肉疾病（包括青少年皮肌炎、杜氏营养不良等）显示上调。基于我们在体外和体内的大量初步数据，我们提出了一个模型，其中PITX 1在成人肌肉中的过度表达引起关键的肌肉萎缩途径，并且进一步地，PITX 1受DUX 4表达的调节。目前这项提案的目标是进一步发展我们的病理生理学模型，以显示4 q35缺失，DUX 4和PITX 1之间的直接关系。拟议的研究在很大程度上依赖于在体内和体外进行的时间序列。还将确定基因/基因相互作用。在目标1中，我们提出确定Pitxl是否是DUX 4的直接目标。我们将确定Pitxl的启动子区域中的推定DUX 4结合位点是否是功能性的，以及它是否被DUX 4特异性地和直接地调节。其他DUX 4靶标将通过时间分析来鉴定。将确定DUX 4与潜在靶基因之间的相互作用。在目标2中，我们提出产生和表征条件性肌肉特异性Pitxl转基因小鼠模型。将评价表型的各种临床、功能、生化、分子和组织学参数的变化。还将评价成肌细胞的表型，包括外观、增殖、分化和对氧化应激的敏感性。此外，我们将确定疾病表型是否可逆。在目标3中，我们将使用Pitxl转基因小鼠来定义Pitxl表达下游的分子转录途径。将进行时间表达谱分析以构建由Pitxl调节的途径。Pitxl与Pitxl的潜在调控靶点之间的相互作用将进一步研究。我们的初步数据表明，DUX 4和Pitxl的疾病特异性上调以及参与肌肉萎缩的基因的下游变化可能参与FSHD的病理生理学。拟议的研究将确定FSHD病理级联中的关键参与者，并确定它们之间的相互作用，这可能用于开发该疾病的治疗方法。