Long noncoding RNAs and chromatin regulation in cocaine addiction

描述（由申请人提供）：最近的研究表明，组蛋白修饰酶是染色质状态的关键调节因子，有助于可卡因介导的基因表达、神经适应和寻找行为的变化。然而，在成瘾的背景下，只有有限数量的组蛋白修饰蛋白进行了研究，特别是缺乏被称为布罗莫结构域的表观遗传“阅读器”蛋白的研究。在与成瘾有关的组蛋白修饰酶中，已知有几种与多种蛋白质形成复合物以表观遗传地改变转录，但对这些相互作用中涉及的潜在机制仍知之甚少。越来越多的证据表明，细胞类型特异性的长非编码RNA（lncRNA）调节这些表观遗传蛋白和/或复合物的功能，作为支架，帮助招募这些过程的特定基因组位点。因此，研究lncRNA在奖励相关脑区中的作用提供了一种全新的方法来确定成瘾中涉及的新表观遗传机制。在本申请中，我们的目的是确定新的组蛋白修饰蛋白参与可卡因摄入量和可卡因相关的表观遗传靶点和lncRNA之间的相互作用，改变后自我管理的可卡因。我们假设可卡因自我给药习惯的形成部分是由于选择组蛋白修饰蛋白和特异性lncRNA表达的协调变化，这些蛋白和特异性lncRNA协同作用以表观遗传学改变基因转录。具体目的1：检验溴结构域基因的脑内敲低影响可卡因自我施用的假设。从我们的实验室收集的初步数据表明，特定的溴结构域蛋白在可卡因奖励中起着重要作用，并在可卡因自我给药后的丘脑核中增加。目标1将测试这些布罗莫结构域是否在限制和扩展进入条件下调节可卡因自我给药。具体目标二：验证可卡因自我给药后，在延髓核中发生独特的长非编码RNA -蛋白质相互作用的假设。长的非编码RNA是染色质状态的关键调节因子，但目前还不清楚这些转录本如何与表观遗传蛋白相互作用，以促进药物依赖。这些研究将确定lncRNA和组蛋白修饰蛋白之间的新的相互作用，并确定这些协会是否改变后，轭，限制和延长获得可卡因自我管理。通过揭示与可卡因摄入有关的新表观遗传靶点和未知表观遗传机制，更好地了解这些系统最终可能会为可卡因成瘾带来新的治疗途径。

DESCRIPTION (provided by applicant): Recent studies have implicated histone-modifying enzymes as key regulators of chromatin state that contribute to cocaine-mediated changes in gene expression, neuroadaptations and seeking behaviors. However, only a limited number of histone-modifying proteins have been studied in the context of addiction, and particularly lacking are studies of epigenetic 'reader' proteins called bromodomains. Of the histone- modifying enzymes implicated in addiction, several are known to form complexes with multiple proteins in order to epigenetically alter transcription, but the underlying mechanisms involved in these interactions remain poorly understood. Growing evidence suggests that cell-type specific long noncoding RNAs (lncRNAs) modulate the function of these epigenetic proteins and/or complexes by acting as scaffolds that help recruit these processes to specific genomic loci. Therefore, investigating the role of lncRNAs in reward-related brain areas offers a fundamentally new approach to identify novel epigenetic mechanisms involved in addiction. In this application we aim to identify novel histone-modifying proteins involved in cocaine intake and determine the interactions between cocaine-related epigenetic targets and lncRNAs that are altered following self-administration of cocaine. We hypothesize that development of cocaine self-administration habit, in part, results from a coordinated change in expression of select histone-modifying proteins and specific lncRNAs that work in concert to epigenetically alter gene transcription. To test this hypothesis, the following aims are proposed: Specific Aim 1: Test the hypothesis that intra-accumbal knockdown of bromodomain genes affects cocaine self-administration. Preliminary data collected from our laboratory indicates that specific bromodomain proteins play an important role in cocaine reward and are increased in the nucleus accumbens following cocaine self-administration. Aim 1 will test whether these bromodomains regulate cocaine self- administration under restricted and extended access conditions. Specific Aim 2: Test the hypothesis that unique long noncoding RNA - protein interactions occur in the nucleus accumbens following cocaine self- administration. Long noncoding RNAs are key regulators of chromatin state, but it is unclear how these transcripts interact with epigenetic proteins to contribute to drug dependence. These studies will identify novel interactions between lncRNAs and histone-modifying proteins in the nucleus accumbens and determine if these associations are altered following yoked, restricted and extended access to cocaine self-administration. By revealing novel epigenetic targets and unchartered epigenetic mechanisms implicated in cocaine intake, a better understanding of these systems may ultimately lead to new therapeutic avenues for cocaine addiction.