CNS in Congenital DM1: Pathogenesis and Therapeutic Opportunities

先天性 DM1 中的中枢神经系统：发病机制和治疗机会

基本信息

批准号：
10553142
负责人：
LUBOV T TIMCHENKO
金额：
$ 35.56万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10553142
关键词：
Adult Affect Aftercare Age Age Months Anxiety Brain CDK4 gene CUG repeat Central Nervous System Clinical Research Clinical Trials Complex Congenital Myotonic Dystrophy Defect Development Disease Event Family Functional disorder Genes Growth Heart Human Knock-in Knowledge Long-Term Effects Messenger RNA Modeling Molecular Motor Mus Muscle Muscle Fibers Mutate Myoblasts Myotonic dystrophy type 1 Nervous System Physiology Organ Pathogenesis Pathology Pathway interactions Patients Phase Phenotype Phosphorylation Phosphotransferases Proteins RNA Splicing RNA metabolism RNA-Binding Proteins Role Severities Signal Pathway Site Skeletal Muscle Stress Survival Rate System Testing Therapeutic Therapeutic Effect Tissues Translations Work biopharmaceutical industry cognitive function cyclin D3 disability drug candidate drug development improved inhibitor mRNA Translation mouse model mutant pediatric patients postnatal prenatal stress granule transcriptome

项目摘要

Myotonic Dystrophy type 1 (DM1) is a complex disease affecting many organs including skeletal muscle and the Central Nervous System (CNS). The majority of mechanistic studies in the DM1 field have been focused on muscle and very little is known about the molecular pathogenesis of CNS dysfunction in DM1. DM1 is caused by the expanded CUG repeats which misregulate RNA-binding proteins of two families, MBNL and CUGBP (CELF). Proteins of both families are expressed in many tissues, including the CNS. CUGBP1 activity is regulated by GSK3-cyclin D3-CDK4 dependent phosphorylation. In DM1, CUG repeats reduce phosphorylation of CUGBP1 at S302 via increase of GSK3 kinase, thereby converting active CUGBP1 into inactive un-pS302-CUGBP1 (termed CUGBP1 repressor or CUGBP1REP) because it blocks translation of mRNAs in Stress Granules. We found that GSK3 is increased in the brains of congenital DM1 (CDM1) mice (DMSXL model). CUGBP1REP is also elevated in the brains of DMSXL mice. The prenatal treatment of DMSXL mice with the inhibitor of GSK3, tideglusib (TG), increases survival rate of underdeveloped DMSXL mice, improves their growth and strength and reduces their anxiety. These findings suggest that the inhibitors of GSK3 are good candidate drugs to reduce CNS defects in CDM1 via correction of GSK3-CUGBP1REP pathway in brain. In support of this hypothesis, recent Phase IIa clinical trial for adult CDM1 showed that TG has beneficial effect on cognitive function in patients with CDM1. Since GSK3 has many substrates in brain, the inhibitors of GSK3 might affect many pathways. This project will determine the contribution of the GSK3-CUGBP1REP pathway in CNS pathogenesis of CDM1 (Aim 1). We will address this question by analysis of DMSXL mice crossed with a new mouse model in which the GSK3-cyclin D3-CDK4 site of CUGBP1 (S302) is mutated (S302A knock in model). The molecular pathways disrupted by the mutant DMPK mRNA in the brains of DMSXL mice will be compared to those disrupted by CUGBP1REP in the brains of S302A mice. We found that the inhibitor of GSK3, TG, reduces the mutant DMPK mRNA in skeletal muscle cell precursors from patients with CDM1, correcting splicing events in myoblasts. To determine if TG has the same function in CNS of CDM1, we will test if TG reduces the mutant DMPK mRNA in the brains of DMSXL mice, normalizing splicing of brain-specific mRNAs (Aim 2). Positive long-term effect of the prenatal treatment of DMSXL mice with TG suggests that early correction of GSK3 in CDM1 is critical for the improved development of CDM1 patients. Aim 3 of the project will test if short postnatal treatments with TG have a long-term positive effect on phenotype of DMSXL mice. The therapeutic effect of TG will be also examined in DMSXL mice, treated at young age and in adulthood. The knowledge generated is critical for the development of the GSK3 based therapies of CNS dysfunction in CDM1.

强直性肌营养不良 1 型 (DM1) 是一种复杂的疾病，影响许多器官，包括骨骼肌和 DM1 领域的大多数机制研究都集中在肌肉上，而对于 DM1 中 CNS 功能障碍是由错误调节 RNA 结合的扩展 CUG 引起的分子发病机制知之甚少。两个家族的蛋白质，MBNL 和 CUGBP (CELF) 两个家族的蛋白质在许多组织中表达，包括 CNS 活性受 GSK3-cyclin 调节。在 DM1 中，CUG 重复通过 GSK3 激酶的增加减少 S302 处 CUGBP1 的磷酸化，从而将活性 CUGBP1 转化为非活性非活性非 pS302-CUGBP1（称为 CUGBP1 阻遏物或 CUGBP1REP），因为它会阻断应激颗粒中 mRNA 的翻译。我们发现先天性 DM1 的大脑中 GSK3 增加。 (CDM1) 小鼠（DMSXL 模型）中 DMSXL 小鼠的大脑中 CUGBP1REP 也升高。用 GSK3 抑制剂 tidglusib (TG) 对 DMSXL 小鼠进行产前治疗，可提高发育不全的 DMSXL 小鼠的存活率，改善其生长和力量。这些发现表明，GSK3 抑制剂是通过纠正 GSK3-CUGBP1REP 通路来减少 CDM1 中 CNS 缺陷的良好候选药物。为了支持这一假设，最近针对成人 CDM1 的 IIa 期临床试验表明，TG 对 CDM1 患者的认知功能具有有益作用，因为 GSK3 在大脑中具有多种底物，因此 GSK3 的抑制剂可能会影响该项目的许多通路。将确定 GSK3-CUGBP1REP 通路在 CDM1 的 CNS 发病机制中的贡献（目标 1）我们将通过分析与新小鼠模型杂交的 DMSXL 小鼠来解决这个问题。 CUGBP1 (S302) 的 GSK3-cyclin D3-CDK4 位点发生突变（S302A 敲入模型）将 DMSXL 小鼠大脑中突变 DMPK mRNA 破坏的分子通路与 S302A 小鼠大脑中 CUGBP1REP 破坏的分子通路进行比较。我们发现 GSK3 抑制剂 TG 可以减少患有以下疾病的患者骨骼肌细胞前体中的突变 DMPK mRNA： CDM1，纠正成肌细胞中的剪接事件为了确定 TG 在 CNS 中是否具有与 CDM1 相同的功能，我们将测试 TG 是否会减少 DMSXL 小鼠大脑中的突变 DMPK mRNA，从而使大脑特异性 mRNA 的剪接正常化（目标 2）。用 TG 对 DMSXL 小鼠进行产前治疗的积极长期效果表明，CDM1 中 GSK3 的早期校正对于改善 CDM1 的发育至关重要该项目的目标 3 将测试 TG 的短期出生后治疗是否对 DMSXL 小鼠的表型有长期的积极影响。还将在年轻时和成年期接受治疗的 DMSXL 小鼠中检查 TG 的治疗效果。生成对于开发基于 GSK3 的 CDM1 中枢神经系统功能障碍疗法至关重要。