Epigenetic mechanisms of sustained transcription across cocaine abstinence

项目总结 可卡因成瘾的特点是强迫吸毒和极易复发。 即使是在长期禁欲之后。因此，成瘾研究领域的一个主要焦点 一直在识别大脑奖赏回路中发生的稳定的可卡因诱导的神经适应。 已知转录变化在整个禁欲过程中持续存在，但潜在的分子 这种坚持不懈的机制仍然难以捉摸。 我们最近发现转录因子Nr4a1(核受体亚家族4) 抑制可卡因奖励和寻觅行为。我们的初步数据显示Nr4a1是一种 可卡因诱导转录的中枢调节因子，包括晚期靶基因表达 禁欲。这项研究的意义因治疗药物的实用性而得到加强 调节Nr4a1和阻止小鼠可卡因自我给药，强调了巨大的 这一基础研究计划在打击毒瘾方面的潜力。 鉴于组蛋白翻译后修饰(HPTM)会导致基因的长期变化 稳定细胞表型所必需的表达，组蛋白修饰在 禁欲可能解释了个体基因如何“记住”先前的药物暴露。我们有 先前发现，在戒断后期，Nr4a1在单个靶基因上调节hPTM。这 提议旨在定义细胞核持续基因表达的机制(S) 雄性和雌性小鼠自愿给予可卡因后的伏隔核(NAC)。我们 应用新方法对染色质和基因表达进行细胞类型特异性定量 在单个样本中。然后，我们用表观遗传学验证了Nr4a1作用的因果机制 在体内编辑。在本研究的结论中，我们将定义特定的细胞类型 Nr4a1在可卡因戒断过程中调节稳定基因表达的机制。超越 为此，我们将应用机器学习来识别持久基因表达的新调节因子 与可卡因成瘾有关。

PROJECT SUMMARY Cocaine addiction is characterized by compulsive drug seeking and high vulnerability to relapse even after prolonged abstinence. A major focus of the field of addiction research has therefore been to identify stable, cocaine-induced neuroadaptations occurring in brain reward circuits. Transcriptional changes are known to persist throughout abstinence, yet the underlying molecular mechanisms of such persistence remain elusive. We recently discovered that the transcription factor, Nr4a1 (nuclear receptor subfamily 4) represses cocaine reward and seeking behavior. Our preliminary data show that Nr4a1 is a central regulator of cocaine-induced transcription, including target gene expression in late abstinence. The significance of this study is strengthened by the utility of therapeutic agents that regulate Nr4a1 and block mouse cocaine self-administration, underscoring the enormous potential of this basic research program in combating drug addiction. Given that histone posttranslational modifications (hPTMs) confer long-lasting changes in gene expression necessary for stable cellular phenotypes, histone modifications acquired during abstinence may explain how individual genes “remember” prior drug exposure. We have previously found that Nr4a1 regulates hPTMs at individual target genes at late abstinence. This proposal aims to define the mechanism(s) of persistent gene expression in the nucleus accumbens (NAc) of male and female mice following volitional cocaine self-administration. We apply novel methods for cell-type specific quantification of both chromatin and gene expression in a single sample. We then validate the causal mechanism of Nr4a1 action using epigenetic editing in vivo. At the conclusion of this study we will have defined the cell-type specific mechanism by which Nr4a1 regulates stable gene expression across cocaine abstinence. Beyond this, we will apply machine learning to identify novel regulators of persistent gene expression relevant to cocaine addiction.