Investigating membrane repair capacity in facioscapulohumeral muscular dystrophy

研究面肩肱型肌营养不良症的膜修复能力

基本信息

批准号：
10365948
负责人：
YI-WEN CHEN
金额：
$ 26.78万
依托单位：
CHILDREN'S RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-06 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10365948
关键词：
4q35 Acute Affect Antisense Oligonucleotides Cell membrane Cells Chromosomes Complex Confocal Microscopy Creatine Kinase D4Z4 Data Defect Disease Disease Pathway Disease Progression Dose Double Effect Epigenetic Process Facioscapulohumeral Muscular Dystrophy Functional disorder Genes Genetic Genetic Transcription Goals Homeobox Homeodomain Proteins Homeostasis Human Individual Injury Laser injury Lead Link Mechanical Stress Mediating Membrane Modeling Molecular Mus Muscle Muscle Cells Muscle Weakness Muscle strain Muscular Atrophy Muscular Dystrophies Mutation Myoblasts Myopathy Oxidation-Reduction Oxidative Stress Pathway interactions Patients Phenotype Play Reactive Oxygen Species Regulation Reporting Repression Role Sarcolemma Secondary to Serum Severities Siblings Skeletal Muscle Surrogate Markers Testing Therapeutic Work Xenograft Model Xenograft procedure biceps brachii muscle disease phenotype dosage drug testing improved in vivo in vivo evaluation knock-down mouse model novel repaired response skeletal therapeutic development

项目摘要

ABSTRACT Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscle disorder caused by complex genetic and epigenetic mechanisms. Previous studies showed that transcription de- repression of double homeobox protein 4 (DUX4) due to epigenetic changes in the D4Z4 region causes FSHD. The epigenetic changes are caused by either contraction of the D4Z4 array from 11-150 repeat units in unaffected individuals to 1-10 repeat units in roughly 95% of patients (FSHD1), or mutations in epigenetic regulators of the D4Z4 region (FSHD2). The expression of DUX4 leads to downstream molecular and cellular changes, which contribute to disease progression. However the cellular mechanisms cause FSHD are not clear. In our preliminary studies we identified cell membrane repair deficit in FSHD myoblasts in comparison to myoblasts from unaffected siblings. Moderate reduction of DUX4 in the FSHD cells partially improved the repair capacity. This repair deficit was also observed in skeletal muscle from an FSHD-like mouse model (FLExDUX4). It is known that FSHD myoblasts are more susceptible to oxidative stress. While reactive oxygen species (ROS) regulation plays an important role in sarcolemmal membrane repair, excessive or prolonged oxidative stress in cells lead to membrane repair deficits. Our novel finding provides a plausible link between the molecular pathways mis-regulated by DUX4 (e.g. oxidative stress) and the FSHD phenotype secondary to reduced membrane repair capacity. The goal of the study is to further investigate the observed membrane repair deficit and test the hypothesis that the membrane repair capacity is modulated by DUX4 levels in myofibers. In aim 1, we will determine if DUX4 expression has a dose-dependent effect on sarcolemmal repair deficit using skeletal muscle-specific inducible mouse model and an antisense oligonucleotide that can modulate DUX4 expression in FLExDXU4 mice. Molecular mechanisms of repair deficits will be investigated. In aim 2, we will evaluate the effect of DUX4 on sarcolemmal repair in FSHD patient myofibers using a xenograft mouse model of FSHD. We will produce human myofibers and test their sarcolemmal repair ability and determine whether AON-mediated knockdown of DUX4 affects the membrane repair ability. The study will identify a novel mechanism, which links previously reported molecular deficits to the disease phenotypes. In addition, the proposed study will determine whether membrane repair can be an appropriate acute readout for therapeutic approaches that aim to reduce DUX4, and its related pathways, in FSHD skeletal muscle.

抽象的 Facioscapulohumeral肌肉营养不良（FSHD）是常染色体显性肌肉疾病由复杂的遗传和表观遗传机制引起。先前的研究表明，转录消除了由于D4Z4区域的表观遗传变化而导致双重同源蛋白4（DUX4）的抑制 FSHD。表观遗传变化是由D4Z4阵列的任何收缩从11-150重复的收缩引起的大约95％的患者（FSHD1）中未受影响的个体的单位至1-10个重复单位，或 D4Z4区域的表观遗传调节剂（FSHD2）。 DUX4的表达导致下游分子和细胞变化，这有助于疾病进展。但是细胞引起FSHD的机制尚不清楚。在我们的初步研究中，我们确定了细胞膜修复与未受影响的兄弟姐妹的成肌细胞相比，FSHD成肌细胞缺陷。中度减少 FSHD细胞中的DUX4部分提高了维修能力。在 FSHD样小鼠模型（FlexDux4）的骨骼肌。众所周知，FSHD成肌细胞是更容易受到氧化应激。而活性氧（ROS）调节作用在肌膜膜修复中的重要作用，细胞中过度或长时间的氧化应激导致膜修复缺陷。我们的新颖发现提供了分子途径之间的合理联系由DUX4（例如氧化应激）和继发于降低的FSHD表型错误调节膜维修能力。该研究的目的是进一步研究观察到的膜修复赤字并检验膜维修能力由DUX4水平调节的假设肌纤维。在AIM 1中，我们将确定DUX4表达是否对肌膜有剂量依赖性作用使用骨骼肌特异性诱导小鼠模型和反义寡核苷酸修复缺陷这可以调节FlexDxU4小鼠中的DUX4表达。修复缺陷的分子机制将被调查。在AIM 2中，我们将评估DUX4对FSHD患者肌膜修复的影响使用FSHD的异种移植小鼠模型的肌纤维。我们将产生人类的肌纤维并测试他们肌膜修复能力，并确定AON介导的DUX4是否会影响膜修复能力。该研究将确定一种新型机制，该机制与先前报道的联系分子缺陷疾病表型。此外，拟议的研究将确定是否对于旨在减少的治疗方法，膜修复可能是适当的急性读数 DUX4及其相关途径，在FSHD骨骼肌中。