Phenylbutazone induces expression of MBNL1 and suppresses formation of MBNL1-CUG RNA foci in a mouse model of myotonic dystrophy.
Phenylbutazone induces expression of MBNL1 and suppresses formation of MBNL1-CUG RNA foci in a mouse model of myotonic dystrophy.
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DOI：
10.1038/srep25317
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发表时间：
2016-04-29
影响因子：
4.6
通讯作者：
Ohno K
中科院分区：
文献类型：
--
作者：
Chen G;Masuda A;Konishi H;Ohkawara B;Ito M;Kinoshita M;Kiyama H;Matsuura T;Ohno K
强直性肌营养不良1型（DM1）是由DMPK基因3′端非翻译区CTG重复序列异常扩增引起的。扩增的CTG重复序列被转录成RNA，并在细胞核中与剪接调节因子MBNL1形成聚集体，称为核灶。核灶螯合并下调MBNL1的可用性。DM 1有对症治疗，但无合理治疗。在这项研究中，我们发现，非甾体抗炎药（NSAID），保泰松（PBZ），上调MBNL1的表达在C2C12成肌细胞以及在HSALR小鼠模型DM1。在DM1小鼠模型中，PBZ改善了Clcn1、Nfix和Rpn 2的异常剪接。PBZ可增加HSALR小鼠骨骼肌氯通道的表达，减少异常的肌纤维中央核团，并改善跑轮活动。我们发现，PBZ的效果是由两个不同的机制。首先，PBZ抑制Mbnl1内含子1中增强子区域的甲基化，并增强Mbnl1 mRNA的转录。其次，PBZ减弱MBNL1与细胞内和体外异常扩增的CUG重复序列的结合。我们的研究表明，PBZ是DM1的有效治疗剂，可上调MBNL1的可用性。
Myotonic dystrophy type 1 (DM1) is caused by abnormal expansion of CTG repeats in the 3′ untranslated region of the DMPK gene. Expanded CTG repeats are transcribed into RNA and make an aggregate with a splicing regulator, MBNL1, in the nucleus, which is called the nuclear foci. The nuclear foci sequestrates and downregulates availability of MBNL1. Symptomatic treatments are available for DM1, but no rational therapy is available. In this study, we found that a nonsteroidal anti-inflammatory drug (NSAID), phenylbutazone (PBZ), upregulated the expression of MBNL1 in C2C12 myoblasts as well as in the HSALR mouse model for DM1. In the DM1 mice model, PBZ ameliorated aberrant splicing of Clcn1, Nfix, and Rpn2. PBZ increased expression of skeletal muscle chloride channel, decreased abnormal central nuclei of muscle fibers, and improved wheel-running activity in HSALR mice. We found that the effect of PBZ was conferred by two distinct mechanisms. First, PBZ suppressed methylation of an enhancer region in Mbnl1 intron 1, and enhanced transcription of Mbnl1 mRNA. Second, PBZ attenuated binding of MBNL1 to abnormally expanded CUG repeats in cellulo and in vitro. Our studies suggest that PBZ is a potent therapeutic agent for DM1 that upregulates availability of MBNL1.