Mechanism of Skeletal Muscle Calcium Dysregulation in Myotonic Dystrophy

强直性肌营养不良骨骼肌钙失调的机制

基本信息

批准号：
10679063
负责人：
John Lueck
金额：
$ 44.48万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-08 至 2027-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10679063
关键词：
Action Potentials Adult Affect Age Alternative Splicing Breeding CUG repeat Calcium Calcium Channel Calcium Channel Blockers Calpain Cessation of life Clinic Coupling Defect Development Drug Targeting Evolution Exclusion Exhibits Exons Future Genes Genetic Transcription Goals Health Heart Block Heterozygote Histology Homeostasis Human Hypercapnia Impairment Individual Life Limb structure Link Longevity Longitudinal Studies Measures Membrane Mitochondria Modeling Morphology Mus Muscle Muscle Fibers Muscle Weakness Muscle function Myopathy Myotonia Myotonic Dystrophy Myotonic dystrophy type 1 Neonatal Nuclear RNA Oral Oxygen saturation measurement Paresis Pathogenesis Pathologic Patients Perinatal Pharmaceutical Preparations Phenotype Plethysmography Process Protein Isoforms Proteins Proteolysis RNA RNA Splicing Regulation Respiratory Diaphragm Respiratory Failure Respiratory Mechanics Respiratory physiology Running RyR1 SERCA1 Series Skeletal Muscle Techniques Testing Therapeutic Therapeutic Intervention Toxic effect Transcript Treatment Protocols United States Food and Drug Administration Verapamil Weight Gain channel blockers combinatorial design effective therapy feeding fetal improved in vivo insight mortality mouse model muscle strength myotonic dystrophy protein kinase pharmacologic posttranscriptional premature ranolazine reconstitution respiratory response skeletal muscle weakness species difference targeted treatment transcriptome

项目摘要

ABSTRACT: Key components of skeletal muscle that regulate excitability and excitation-contraction coupling (ECC) undergo major shifts of isoform expression during development. This process of perinatal ECC remodeling is highly conserved throughout vertebrate evolution and results mainly from post-transcriptional mechanisms in which alternative splicing of specific exons for ClC-1, CaV1.1, RyR1 and SERCA1 occurs. In myotonic dystrophy (DM), these splicing switches revert to their fetal set points due to sequestration of MBNL splicing factors in nuclear RNA foci. We used gene editing to recreate individual DM splicing defects in mice and systematically analyzed mice for effects in isolation and in combination through breeding. Our preliminary studies indicate that loss of ClC-1 function combined with CaV1.1 exon 29 exclusion (Cav1.1∆e29), comparable to that observed in DM patients, results in severe muscle weakness and respiratory deficits and is lethal in mice by age ~9 wks. This effect is rescued by long-term treatment by oral feeding with a Food & Drug Administration (FDA) approved calcium channel blocker. Here we propose studies to define mechanisms and explore the possibility that drug treatments that target myotonia and Cav1.1 channels can mitigate muscle weakness in DM. In Aim 1 we will investigate the mechanism for the early demise of myotonic Cav1.1∆e29 mice, including the study of how Cav1.1∆e29 channels impact membrane excitability and Ca2+ homeostasis, and downstream effectors that include calpain, transcription and mitochondrial health. Further, we will determine if myotonic Cav1.1∆e29 mice exhibit skeletal muscle weakness and altered respiratory function. In Aim 2 we will treat myotonic Cav1.1∆e29 mice by oral feeding of FDA approved drugs that target the calcium channel or myotonia by factorial design (one, the other, both or neither) to see which treatment is most effective at extending life and improving muscle and respiratory function. In Aim 3 we will move the treatment into a CUG repeat expansion DM1 mouse model that exhibits severe muscle weakness, myopathic features and shortened lifespan. We will use a series of non- invasive techniques to measure muscle and respiratory function to determine treatment benefit in longitudinal studies. The ultimate goal of this proposal is to identify DM1 therapeutic interventions that can be rapidly transitioned to the clinic.

抽象的：骨骼肌的关键组成部分调节令人兴奋性和兴奋性耦合（ECC）在发育过程中同工型表达的主要变化。围产期ECC重塑的这一过程很高在整个脊椎动物演变中保守，主要来自转录后机制，其中发生CLC-1，CAV1.1，RYR1和SERCA1的特定外显子的替代剪接。在肌发育症（DM）中，这些剪接开关由于核中MBNL剪接因子的介入而恢复为胎儿设定点 RNA焦点。我们使用基因编辑来重现小鼠中的单个DM剪接缺陷并进行系统分析小鼠孤立的效果和通过育种结合。我们的初步研究表明失去 CLC-1函数与CAV1.1外显子29排除（CAV1.1ΔE29）结合，与在DM中观察到的相当患者，导致严重的肌肉无力和呼吸道缺陷，在大约9周时，小鼠致死。这效果通过对食品药物管理局（FDA）批准的口服喂养的长期治疗做出了反应钙通道阻滞剂。在这里，我们提出的研究以定义机制并探讨药物的可能性针对肌瘤和CAV1.1通道的治疗可以减轻DM的肌肉无力。在目标1中，我们将研究了肌发量cav1.1Δe29小鼠早期灭亡的机制，包括研究如何 CAV1.1ΔE29频道影响膜令人兴奋和CA2+稳态，以及包括钙蛋白酶，转录和线粒体健康。此外，我们将确定MyotonicCav1.1ΔE29小鼠是否表现出来骨骼肌无力和呼吸功能改变。在AIM 2中，我们将通过 FDA批准的药物的口服喂养，该药物以阶乘设计为目标（一个，一个，其他，两者既是），以查看哪种治疗方法在延长寿命和改善肌肉和呼吸功能。在AIM 3中，我们将把处理转移到CUG重复扩展DM1小鼠模型中表现出严重的肌肉无力，肌病特征和寿命缩短。我们将使用一系列非 - 测量肌肉和呼吸功能以确定纵向益处的侵入性技术研究。该提案的最终目标是确定可以迅速进行的DM1治疗干预措施过渡到诊所。