Antisense oligonucleotide treatment for myotonic dystrophy

描述(由申请人提供)：强直性肌营养不良1型(DM1)是一种相对常见的肌营养不良症。遗传基础是DMPK 3‘非翻译区CTG重复序列的扩张，DMPK是一种编码蛋白激酶的基因，在骨骼肌、心肌、平滑肌和神经元中表达。这种不寻常的突变导致RNA占优势，其中含有扩展的CUG(CUG^“‘’)重复序列的RNA表达导致细胞功能障碍。突变的RNA聚集在核焦点中，并启动一系列复杂的下游事件，如RNA剪接调控的缺陷。因此，一个有吸引力的治疗方法是通过加速清除有毒RNA来从根本上解决问题。为此，我们建议开发针对突变的人DMPK(mut-hDMPK)mRNA的RNaseH活性反义寡核苷酸(ASO)。以往的研究表明，ASOS在骨骼肌和心肌中的生物分布和活性都很低。相比之下，我们发现，当针对保留在细胞核中的转录本时，系统传递的ASO在野生型小鼠的肌肉中高度活跃--可能是因为这是RNaseH活跃的隔室。因此，我们推测，CUG扩展的转录本也可能在肌肉中显示有效的敲除，因为它们也保留在细胞核中。与这一想法一致的是，皮下注射ASO四周后，转基因小鼠的CUG(R)‘’转录本被高效地敲除，RNA剪接错乱被逆转，肌强直得到挽救。我们现在寻求开发最有效的、系统活性的ASO，目标是在骨骼肌和心肌中切割MUT-hDMPK转录本。开发计划要求鉴定在细胞中高度活跃的ASO，选择在转基因小鼠中显示最佳mut-hDMPK敲除的ASO，消除对啮齿动物和猴子具有不可接受毒性的ASO，然后使用GMP制造的药物进行IND毒理学/药理学研究。为了实现这些目标，我们已经形成了一个学术-商业合作，其中包括将DM1药物治疗引入临床所需的所有科学、临床、监管和制造专业知识。 公共卫生相关性：强直性肌营养不良是一种遗传性疾病，可导致进行性残疾和过早死亡。目前还没有可以改善症状或减缓疾病进展的治疗方法。这个项目的目标是开发一种治疗强直性肌营养不良的药物。

DESCRIPTION (provided by applicant): Myotonic dystrophy type 1 (DM1) is a relatively common form of muscular dystrophy. The genetic basis is an expansion of CTG repeats in the 3' untranslated region of DMPK, a gene encoding a protein kinase expressed in skeletal, cardiac, and smooth muscle, and in neurons. This unusual mutation gives rise to RNA dominance, in which expression of RNA containing an expanded CUG (CUG^"'') repeat leads cell dysfunction. The mutant RNA accumulates in nuclear foci and initiates a complex cascade of downstream events, such as, defects in the regulation of RNA splicing. An attractive therapeutic approach, therefore, is to attack the problem at its root cause, by accelerating the clearance of the toxic RNA. To this end, we are proposing to develop RNase H-active antisense oligonucleotides (ASOs) targeting the mutant human DMPK {mut-hDMPK) mRNA. Previous studies have indicated that biodistribution and activity of ASOs in skeletal and candiac muscle is low. In contrast, we have found that systemically-delivered ASOs are highly active in muscle of wild-type mice, when targeted against a transcript that is retained in the nucleus - presumably because this is the compartment in which RNase H is active. We therefore postulated that CUG-expanded transcripts may also show efficient knockdown in muscle, because they also are retained in the nucleus. Consistent with this idea, subcutaneous administration of ASO for four weeks caused highly effective knockdown of CUG(R)"'' transcripts in muscle, reversal of RNA splicing derangements, and rescue of myotonia in transgenic mice. We seek now to develop optimally-effective, systemically-active ASOs that target mut- hDMPK transcripts for cleavage in skeletal and cardiac muscle. Development plans call for identification of ASOs that are highly active in cells, selection of ASOs that show optimal mut-hDMPK knockdown in transgenic mice, elimination of ASOs that show unacceptable toxicity in rodents and monkeys, and then IND- enabling toxicology/pharmacology studies using GMP-manufactured drug. To accomplish these goals we have formed an academic-commercial collaboration that includes all of the scientific, clinical, regulatory, and manufacturing expertise that is needed to bring a drug treatment for DM1 to the clinic. PUBLIC HEALTH RELEVANCE: Myotonic dystrophy is an inherited disease that causes progressive disability and premature death. No treatment is currently available that can improve the symptoms or slow the disease progression. The goal of this project is to develop a drug treatment for myotonic dystrophy.