Reversal of phenotypes in MECP2 duplication mice using genetic rescue or antisense oligonucleotides.
Reversal of phenotypes in MECP2 duplication mice using genetic rescue or antisense oligonucleotides.
复制标题
DOI：
10.1038/nature16159
复制
发表时间：
2015-12-03
期刊：
影响因子：
64.8
通讯作者：
Zoghbi HY
中科院分区：
文献类型：
--
作者：
Sztainberg Y;Chen HM;Swann JW;Hao S;Tang B;Wu Z;Tang J;Wan YW;Liu Z;Rigo F;Zoghbi HY
拷贝数变异经常与发育迟缓、智力残疾和自闭症谱系障碍有关。MECP2重复综合征是男性中最常见的基因组重排之一，其特征是自闭症、智力残疾、运动功能障碍、焦虑、癫痫、复发性呼吸道感染和早期死亡。甲基cpg结合蛋白2 （MeCP2）过表达引起的广泛缺陷对传统的基于生化途径的治疗方法提出了严峻的挑战。因此，我们寻求直接靶向MeCP2并可转化为临床治疗的策略。然而，第一个问题是，在症状出现后，神经功能障碍是否可逆。在一些单基因功能丧失的神经疾病模型中，包括Rett综合征中MeCP2的缺失，已经证明了成年症状小鼠的表型逆转，这表明，至少在某些情况下，神经解剖学可能保持足够完整，因此纠正这些疾病背后的分子功能障碍可以恢复健康的生理。鉴于MECP2重复综合征中不存在神经退行性变，我们假设在MECP2重复的成年小鼠中恢复正常的MECP2水平可以挽救它们的表型。因此，我们首先建立并表征了一个条件MeCP2过表达的小鼠模型，并表明MeCP2水平的纠正在很大程度上逆转了行为、分子和电生理缺陷。接下来，我们寻求一种转化策略来减少MeCP2，并转向反义寡核苷酸（ASOs）。ASOs是一种小的修饰核酸，可以选择性地与靶基因转录的mRNA杂交并使其沉默，并已成功用于纠正不同小鼠模型中的缺陷。我们发现ASO治疗在成年有症状的转基因MECP2重复小鼠（MECP2- tg）中诱导了广泛的表型拯救，并以剂量依赖的方式纠正了MECP2重复患者淋巴母细胞样细胞中的MECP2水平。
Copy number variations have been frequently associated with developmental delay, intellectual disability, and autism spectrum disorders. MECP2 duplication syndrome is one of the most common genomic rearrangements in males and is characterized by autism, intellectual disability, motor dysfunction, anxiety, epilepsy, recurrent respiratory tract infections, and early death. The broad range of deficits caused by methyl-CpG-binding protein 2 (MeCP2) overexpression poses a daunting challenge to traditional biochemical pathway-based therapeutic approaches. Accordingly, we sought strategies that directly target MeCP2 and are amenable to translation into clinical therapy. The first question, however, was whether the neurological dysfunction is reversible after symptoms set in. Reversal of phenotypes in adult symptomatic mice has been demonstrated in some models of monogenic loss-of-function neurological disorders, including loss of MeCP2 in Rett syndrome, indicating that, at least in some cases, the neuroanatomy may remain sufficiently intact so that correction of the molecular dysfunction underlying these disorders can restore healthy physiology. Given the absence of neurodegeneration in MECP2 duplication syndrome, we hypothesized that restoration of normal MeCP2 levels in MECP2 duplication adult mice would rescue their phenotype. Therefore, we first generated and characterized a conditional Mecp2-overexpressing mouse model and showed that correction of MeCP2 levels largely reversed the behavioral, molecular, and electrophysiological deficits. Next, we sought a translational strategy to reduce MeCP2 and turned to antisense oligonucleotides (ASOs). ASOs are small modified nucleic acids that can selectively hybridize with mRNA transcribed from a target gene and silence it, and have been successfully used to correct deficits in different mouse models. We found that ASO treatment induced a broad phenotypic rescue in adult symptomatic transgenic MECP2 duplication mice (MECP2-TG), and corrected MECP2 levels in lymphoblastoid cells from MECP2 duplication patients in a dose-dependent manner.