Mechanisms of DUX4 mediated FSHD pathology

DUX4 介导的 FSHD 病理机制

• 批准号: 10554358
• 负责人: Peter L Jones
• 金额: $ 60.52万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-03 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10554358
• 关键词: 4q35; ASH1L gene; Address; Adult; Affect; Age; Animal Model; Animal Muscular Dystrophy; Artificial Human Chromosomes; Automobile Driving; Biological; Biological Assay; Cells; Chromatin; Chromatin Remodeling Factor; Chromosomes; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; D4Z4; Development; Disease; Distal; Engraftment; Enhancers; Epigenetic Process; Facioscapulohumeral Muscular Dystrophy; Female; Funding; Gene Expression; Gene Expression Profile; Genes; Genetic; Genome; Goals; Health; Human; Mediating; Modeling; Mus; Muscle; Muscle Cells; Muscle Development; Muscle Fibers; Myoblasts; Myopathy; Natural regeneration; Pathogenesis; Pathogenicity; Pathology; Pathway interactions; Patients; Proteins; Regulation; Relaxation; Reporter; Repression; Role; SMARCA5 gene; Severities; Skeletal Muscle; Specificity; Testing; Therapeutic; Therapeutic Intervention; Tissues; Transgenic Organisms; Validation; Xenograft procedure; causal variant; diagnostic assay; effective therapy; in vivo; insight; knock-down; male; mouse model; new therapeutic target; novel; prevent; targeted treatment; therapeutic development; therapeutic target; translational potential; virulence gene

SUMMARY Facioscapulohumeral Muscular Dystrophy (FSHD) is one of the most prevalent myopathies affecting males and females of all ages, and currently there is no cure or therapeutic intervention available. The long-term goal of this project is to determine the epigenetic mechanisms leading to pathogenic gene expression in FSHD, and identify regulatory components that are viable targets for therapeutic development. FSHD is a complex genetic and epigenetic disease caused by chromatin relaxation of the D4Z4 macrosatellite repeat array at chromosome 4q35, which leads to aberrant expression of the DUX4 gene from the distal-most repeat unit. The DUX4 protein, in turn, activates a host of genes normally expressed in early development, which cause pathology when mis-expressed in adult skeletal muscle. This established model of FSHD pathogenesis has stimulated the search for DUX4- based therapeutic targets, including approaches to block DUX4 expression. While normal mechanisms of D4Z4 repression have been well-characterized, very little is known about the factors and pathways responsible for facilitating aberrant activation of DUX4. Previously, we showed that the degree and stability of epigenetic dysregulation at the FSHD-associated 4q35 locus is the key determinant for DUX4 expression, clinical presentation, and severity of FSHD pathology. Thus, targeting epigenetic dysregulation in FSHD is a potentially powerful therapeutic avenue. Such an approach would be greatly aided by a better understanding of the factors facilitating DUX4 expression, each of which represents a potential target for therapeutic inhibition. In a candidate-based screen, we identified several epigenetic regulators with druggable domains that function as novel activators of DUX4. Here, we will characterize these epigenetic facilitators of DUX4 expression and validate their potential as therapeutic targets in FSHD. We will determine the global effects of reducing the expression of these factors on skeletal muscle health and development using primary patient cells and novel animal models. Finally, we will test the translational potential of inhibiting these DUX4 regulators in an FSHD human xenograft mouse model derived from FSHD patient myoblasts with their endogenous D4Z4 arrays. DUX4 regulators will be inhibited by CRISPR inhibition and assayed for specificity. Successful completion of this project will provide key insights into the mechanisms of epigenetic dysregulation in FSHD and validate the translational potential of novel therapeutic targets in vivo.

概括 Facioscapulohumeral肌肉营养不良（FSHD）是影响的最普遍的肌病之一 各个年龄段的男性和女性，目前尚无治愈或治疗干预措施。这 该项目的长期目标是确定导致致病基因的表观遗传机制 在FSHD中的表达，并确定是治疗靶标的调节组件 发展。 FSHD是一种复杂的遗传和表观遗传疾病，由染色质松弛引起 D4Z4宏观卫星在4q35染色体上重复阵列，导致异常表达 远端重复单元的DUX4基因。 DUX4蛋白又激活了许多基因 通常在早期发育中表达，这会导致病理 骨骼肌。这种已建立的FSHD发病机理模型刺激了对Dux4-的搜索 基于治疗靶标，包括阻断DUX4表达的方法。虽然正常 D4Z4抑制的机制已得到很好的特征，对这些因素知之甚少 以及负责促进DUX4异常激活的途径。以前，我们证明了 在FSHD相关的4Q35基因座上表观遗传失调的程度和稳定性是关键 DUX4表达，临床表现和FSHD病理严重程度的决定因素。因此， FSHD中靶向表观遗传失调是一种潜在强大的治疗途径。这样的 更好地理解促进DUX4的因素，可以极大地帮助方法 表达，每种表达代表了治疗抑制的潜在靶标。在候选人中 屏幕，我们确定了几个具有可药物域的表观遗传调节剂，它们充当新颖 DUX4的激活剂。在这里，我们将表征Dux4表达和 在FSHD中验证其作为治疗靶标的潜力。我们将确定全球影响 使用主要 患者细胞和新型动物模型。最后，我们将测试抑制这些的翻译潜力 FSHD人异种移植小鼠模型中的DUX4调节剂，该模型衍生自FSHD患者成肌细胞 带有内源性D4Z4阵列。 DUX4调节器将受到CRISPR抑制和 分析特异性。该项目的成功完成将为您提供关键的见解 FSHD表观遗传失调的机制并验证了新型的翻译潜力 体内治疗靶标。