The Role of Histone Variant H3.3 and miR-128 in Learned Vocal Communication

项目摘要 依赖经验的表观遗传学的发现使认知的分子研究发生了革命性的变化 改建。这些过程背后的机制被认为与自闭症谱系障碍有关。 以及与沟通障碍相关的其他形式的智力残疾。表观遗传 机制有望成为发育障碍的治疗靶点，因为它们可能 提高言语治疗等环境干预的效果。鸣禽是最常见的 用于人类语音的模型，因为它们允许进行旨在理解分子的行为实验 学习发声交流的基础。与其他模式生物不同，斑马雀学习复杂 通过观察社会环境中的成年人发出的声音。我们实验室和其他实验室的研究表明 FoxP2等歌曲和语言相关基因的动态行为调节是习得发声的基础 通信，但这方面的机制基础有待进一步定性。我们之前使用的是 加权基因共表达网络分析表明，在纹状体歌核X区， 组蛋白H3甲基化擦除器、microRNA-128和转录调节因子组蛋白的表达 H3.3变异与歌唱显著相关。相比之下，这些变化不会在 邻近纹状体区域，不控制歌唱。从这个数据集，我开发了一个工作模型， 歌唱诱导依赖活动的miR-128表达，进而改变抑制转录机制 水平，以揭示特定的歌曲调节基因的H3.3交换和转录激活。为了测试 在这个假设下，我孤立地饲养斑马雀，让它们产生一种贫穷的歌声。然后我 将他们作为成年人重新介绍给一位家教，并每天给予miR-128激活剂人参皂苷治疗 RH2(GRh2)或车辆作为对照。令人兴奋的是，GRh2显著改善了句法刻板印象的缺陷， 使鸟儿能够组织自己的歌声，并以高保真的方式重现。我会调查GRh2是如何拯救 沟通障碍，首先使用RNA测序和染色质表征社交隔离模型 免疫沉淀测序。然后，我将生成一个siRNA结构来在X区击倒miR-128，并 使用RNAseq分析这对歌曲和基因表达的影响。然后我会拯救由社会孤立引起的 与GRh2的沟通障碍，并将结果与HDAC抑制剂进行比较，这类药物具有 在智力残疾的动物模型和人类患者身上都显示出了希望。这项研究将带来新的突破 通过测试动态染色质变化和习得的声音交流之间的联系和 介绍GRh2作为一种治疗认知障碍的新表观遗传学疗法。

Project Summary The molecular study of cognition has been revolutionized by the discovery of experience-dependent epigenetic remodeling. The mechanisms underlying these processes have been implicated in autism spectrum disorders and other forms of intellectual disability that are associated with communication deficits. Epigenetic mechanisms are promising therapeutic targets for developmental disorders because they could potentially enhance the efficacy of environmental interventions such as speech therapy. Songbirds are the commonly used model for human speech, as they allow for behavioral experiments designed to understand the molecular basis of learned vocal communication. Unlike other model organisms, zebra finches learn complex vocalizations from observing adults in the social environment. Work from our lab and others reveals that dynamic behavioral regulation of song- and language-related genes such as FoxP2 underlies learned vocal communication, but the mechanistic basis for this awaits further characterization. We previously used Weighted Gene Co-Expression Network Analysis to show that in the striatal song nucleus Area X, changes in the expression of histone H3 methylation erasers, microRNA-128, and the transcriptional regulator histone variant H3.3 are significantly correlated with singing. In contrast, these changes are not observed in a neighboring striatal region that does not control song. From this data set I developed a working model whereby singing induces activity-dependent miR-128 expression, which then alters repressive transcriptional machinery levels in order to expose certain song-regulated genes for H3.3 exchange and transcriptional activation. To test this hypothesis, I raised zebra finches in isolation such that they developed an impoverished song. I then reintroduced them as adults to a tutor and administered daily treatments of the miR-128 activator ginsenoside Rh2 (GRh2) or vehicle as a control. Excitingly, GRh2 significantly ameliorated deficits in syntax stereotypy, allowing the bird to organize his song and reproduce it with high fidelity. I will investigate how GRh2 rescues communication deficits by first characterizing the social isolate model using RNA sequencing and chromatin immunoprecipitation sequencing. I will then generate a siRNA construct to knock down miR-128 in Area X and analyze how this affects song and gene expression using RNAseq. I will then rescue social isolation-induced communication deficits with GRh2 and compare the results to an HDAC inhibitor, a class of drugs that has shown promise in animal models of intellectual disability as well as human patients. This study will break new ground by testing the links between dynamic chromatin changes and learned vocal communication and introduce GRh2 as a novel epigenetic therapeutic for cognitive disorders.