Role of circHomer1 in synaptic plasticity and cocaine-seeking behavior

circHomer1 在突触可塑性和可卡因寻求行为中的作用

• 批准号: 10164747
• 负责人: Janet L Neisewander
• 金额: $ 18.62万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-15 至 2023-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10164747
• 关键词: Abstinence; Address; Animal Model; Antibodies; Attention; Attenuated; Back; Behavior; Binding; Biological Assay; Brain; Central Nervous System Diseases; Chronic; Cocaine; Cocaine Dependence; Coculture Techniques; Code; Corpus striatum structure; Cues; Development; Disease; Drug Addiction; Drug Modelings; Electrophysiology (science); Event; Family; Female; Functional disorder; Gene Expression; Genes; Genetic Transcription; Hippocampus (Brain); Homer 1a; Homer protein; Homologous Gene; Homologous Protein; HuD antigen; Immunoprecipitation; In Situ; Individual; Infusion procedures; Intravenous; Laboratories; Light; Measures; Mediating; Messenger RNA; Metabotropic Glutamate Receptors; MicroRNAs; Modeling; Molecular; Motivation; Mus; Neuronal Plasticity; Neurons; Nucleus Accumbens; Pharmaceutical Preparations; Play; Porifera; Preparation; Process; Property; Protein Splicing; Proteins; Quantitative Reverse Transcriptase PCR; RNA; RNA Splicing; RNA-Binding Proteins; Rattus; Receptor Signaling; Recording of previous events; Research; Reversal Learning; Role; Saline; Self Administration; Signal Transduction; Substance Use Disorder; Synapses; Synaptic plasticity; Synaptosomes; Testing; Training; Untranslated RNA; Virus; Western Blotting; Work; addiction; base; brain abnormalities; circular RNA; cocaine self-administration; cocaine use; conditioned place preference; cue reactivity; drug seeking behavior; environmental enrichment for laboratory animals; experimental study; frontal lobe; immunocytochemistry; insight; knock-down; lentiviral-mediated; mRNA Precursor; male; novel; overexpression; relapse patients; response; small hairpin RNA; synaptic function; transcription factor; treatment strategy

Brain abnormalities associated with substance use disorders (SUDs) involve long-term changes in gene expression that derail motivational circuits toward drug seeking and taking despite negative consequences. While the role of transcription factors in gene expression changes has been well established, the subsequent post-transcriptional events that result in functional change are far from understood. Recent breakthroughs suggest that circular RNAs (circRNAs) are critical in regulating post-transcriptional events. This new class of non-coding RNAs plays a critical role in brain development and synaptic function by acting as sponges for sequestering microRNAs (miRNAs) and RNA-binding proteins (RBPs), which regulate gene expression, often in a competitive manner. For instance, our laboratory has shown that the RBP, HuD, competes with miR-495 to regulate expression of addiction-related genes. Our new preliminary results demonstrate that HuD also binds to, and regulates, the expression and synaptic localization of 14 brain-specific circRNAs, including circHomer1. circHomer1 is generated from the same gene (Homer1) that generates linear Homer1b mRNA, which is also a HuD target. Importantly, Homer1 protein is involved in cocaine–induced plasticity and drug seeking via its role in regulating type I metabotropic glutamate receptor signaling and homeostatic synaptic downscaling after increased neuronal activity. We found that knockdown of circHomer1 levels increases synaptic activity and synaptic Homer1b mRNA levels. Using HuD overexpressing mice, we determined that this process requires binding of the circRNA to HuD. Furthermore, we found that circHomer1 levels in the nucleus accumbens (NAc) are decreased in mice displaying increased cocaine-seeking behavior in the conditioned place preference model. In contrast, the varying levels of operant cocaine-seeking behavior in rats living in an enriched environment (low levels) versus isolation (high levels) during forced abstinence after a history of cocaine self- administration inversely correlate with the ratios of circHomer1 to Homer1b mRNA levels in the NAc shell. Based on these results, we hypothesize that synaptic circHomer1 expression in the NAc shell regulates synaptic activity by competing with Homer1b mRNA for HuD binding, leading to downstream effects in Homer1b function that attenuate drug-seeking behavior. To test this hypothesis, we will first examine whether circHomer1 and Homer1b mRNA compete for HuD binding, transport to synapses, and the control of neuronal activity in neurons in culture. We will then evaluate the effects of lentiviral-mediated manipulations of circHomer1 levels on Homer1b mRNA synaptic levels and the modulation of operant cocaine-seeking behavior. This research will impact the field by elucidating the role of circHomer1 in the mechanisms underlying changes in cocaine-induced neuroplasticity and addiction-related behaviors. Ultimately, gaining an understanding of the molecular mechanisms underlying brain changes in SUDs will aid in developing novel treatment strategies for cocaine use disorders.

与物质使用障碍（SUD）相关的脑异常涉及长期变化 在基因表达中，使动机的动机流向寻求药物和去目的地 负面后果。虽然转录因子在基因表达变化中的作用具有 已经建立了良好的，随后导致功能的转录后事件 变化远非理解。最近的突破表明圆形RNA（CIRCRNA） 对于调节转录后事件至关重要。这个新的非编码RNA播放 通过充当隔离的海绵，在大脑发育和突触功能中的关键作用 microRNA（miRNA）和RNA结合蛋白（RBP），这些蛋白通常调节基因表达，通常 以竞争方式。例如，我们的实验室表明，RBP，HUD竞争 用miR-495调节与成瘾相关基因的表达。我们的新初步结果 证明HUD还结合并调节了的表达和突触定位 14个大脑特异性circrnas，包括circhomer1。 circhomer1是由同一基因产生的 （HOMER1）生成线性HOMER1B mRNA，这也是HUD靶标。重要的是， HOMER1蛋白参与可卡因诱导的可塑性和通过其在其中的作用寻求药物 调节I型代谢型谷氨酸接收器信号传导和稳态突触 神经元活性增加后缩小。我们发现Circhomer1级别的敲低 增加合成活性和合成HOMER1B mRNA水平。使用HUD过表达 小鼠，我们确定此过程需要结合Circrna与HUD。此外，我们 发现在显示的小鼠中，伏隔核中的Circhomer1水平降低 在条件地点偏好模型中增加了可卡因的行为。相反， 生活在丰富环境中的老鼠中，各种各样的可卡因寻求可卡因行为（低 在可卡因自我史上强迫禁欲期间的水平与隔离（高水平） 给药与Circhomer1与HOMER1B mRNA水平的比率成反比 NAC壳。基于这些结果，我们假设合成circhomer1在 NAC壳通过与HOMER1B mRNA竞争HUD结合来调节突触活动， 导致homer1b功能的下游效应，从而减弱寻求毒品的行为。到 检验该假设，我们将首先检查Circhomer1和Homer1b mRNA是否竞争 HUD结合，转运到突触以及培养神经元中神经元活性的控制。 然后，我们将评估慢病毒介导的Circhomer1水平的操作对 HOMER1B mRNA突触水平和可卡因寻求可卡因行为的调节。这 研究将通过阐明Circhomer1在机制中的作用来影响该领域 可卡因引起的神经塑性和与成瘾相关的行为的基本变化。 最终，了解对大脑基础的分子机制变化的理解 SUDS将有助于制定可卡因使用障碍的新型治疗策略。