Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome.
Misregulation of Alternative Splicing in a Mouse Model of Rett Syndrome.
复制标题
DOI：
10.1371/journal.pgen.1006129
复制
发表时间：
2016-06
期刊：
影响因子：
4.5
通讯作者：
Chang Q
中科院分区：
文献类型：
--
作者：
Li R;Dong Q;Yuan X;Zeng X;Gao Y;Chiao C;Li H;Zhao X;Keles S;Wang Z;Chang Q
人类MECP2基因突变导致Rett综合征（RTT），这是一种严重的神经发育障碍，主要影响女孩。尽管经过数十年的研究，MeCP2的分子功能尚未完全了解。在这里，我们报告了一个系统的识别MeCP2相互作用的蛋白质在小鼠大脑。除了转录调节因子外，我们还发现MeCP2与几种RNA剪接调节因子（包括LEDGF和DHX9）发生物理相互作用。这些相互作用被RTT引起的突变破坏，表明它们可能在RTT发病机制中发挥作用。与这个想法一致，深度RNA测序揭示了Mecp2敲除小鼠皮层中数百个剪接事件的错误调节。为了揭示由于MeCP 2的缺失而改变的RNA剪接的功能后果，我们专注于Gria2和其他AMPAR基因的翻转/翻转外显子的剪接的调节。我们发现了一个显着的剪接转变，在翻转/翻转外显子对翻转包容，导致更快的衰减在AMPAR门控电流和改变突触传递。总之，我们的研究确定了MeCP2和剪接因子（一种新的MeCP2靶基因）之间的直接物理相互作用，并在RTT小鼠中建立了特定RNA剪接变化和突触表型之间的功能联系。这些结果不仅有助于我们了解MeCP 2的分子功能，而且还揭示了未来治疗的潜在药物靶点。Rett综合征（RTT）是一种使人衰弱的神经发育障碍，无法治愈或有效治疗。为了充分了解疾病机制并开发治疗方法，有必要研究甲基-CpG结合蛋白2（MeCP2）分子功能的各个方面，其中突变已被确定为RTT的遗传原因。多年来，MeCP 2已被证明可以维持DNA甲基化、调节转录和染色质结构、控制microRNA加工以及调节RNA剪接。在这些已知的功能中，MeCP2在调节RNA剪接中的作用还不太清楚。我们采取了几种无偏倚的方法来研究MeCP2如何调节剪接，MeCP2的丢失引起了什么样的剪接变化，以及改变剪接引起了什么样的功能后果。我们发现MeCP2与剪接因子相互作用以调节谷氨酸受体基因的剪接，谷氨酸受体基因介导大脑中绝大多数兴奋性突触传递;并将谷氨酸受体基因的剪接改变与RTT小鼠模型中的特定突触变化联系起来。我们的研究结果不仅促进了对RTT疾病机制的理解，而且为未来的治疗开发提供了潜在的药物靶点。
Mutations in the human MECP2 gene cause Rett syndrome (RTT), a severe neurodevelopmental disorder that predominantly affects girls. Despite decades of work, the molecular function of MeCP2 is not fully understood. Here we report a systematic identification of MeCP2-interacting proteins in the mouse brain. In addition to transcription regulators, we found that MeCP2 physically interacts with several modulators of RNA splicing, including LEDGF and DHX9. These interactions are disrupted by RTT causing mutations, suggesting that they may play a role in RTT pathogenesis. Consistent with the idea, deep RNA sequencing revealed misregulation of hundreds of splicing events in the cortex of Mecp2 knockout mice. To reveal the functional consequence of altered RNA splicing due to the loss of MeCP2, we focused on the regulation of the splicing of the flip/flop exon of Gria2 and other AMPAR genes. We found a significant splicing shift in the flip/flop exon toward the flop inclusion, leading to a faster decay in the AMPAR gated current and altered synaptic transmission. In summary, our study identified direct physical interaction between MeCP2 and splicing factors, a novel MeCP2 target gene, and established functional connection between a specific RNA splicing change and synaptic phenotypes in RTT mice. These results not only help our understanding of the molecular function of MeCP2, but also reveal potential drug targets for future therapies. Rett syndrome (RTT) is a debilitating neurodevelopmental disorder with no cure or effective treatment. To fully understand the disease mechanism and develop therapies, it is necessary to study all aspects of the molecular function of methyl-CpG binding protein 2 (MeCP2), mutations in which have been identified as the genetic cause of RTT. Over the years, MeCP2 has been shown to maintain DNA methylation, regulate transcription and chromatin structure, control microRNA processing, and modulate RNA splicing. Among these known functions, the role of MeCP2 in modulating RNA splicing is less well understood. We took several unbiased approaches to investigate the how MeCP2 may regulate splicing, what splicing changes are caused by the loss of MeCP2, and what functional consequences are caused by altered splicing. We discovered that MeCP2 interacts with splicing factors to regulated the splicing of glutamate receptor genes, which mediate the vast majority of excitatory synaptic transmission in the brain; and linked the altered splicing of glutamate receptor genes to specific synaptic changes in a RTT mouse model. Our findings not only advance the understanding of RTT disease mechanism, but also reveal a potential drug target for future development of therapies.