Ethanol-Induced Behavioral Sensitization Alters the Synaptic Transcriptome and Exon Utilization in DBA/2J Mice.
Ethanol-Induced Behavioral Sensitization Alters the Synaptic Transcriptome and Exon Utilization in DBA/2J Mice.
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DOI：
10.3389/fgene.2018.00402
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发表时间：
2018
影响因子：
3.7
通讯作者：
Miles MF
中科院分区：
文献类型：
--
作者：
O'Brien MA;Weston RM;Sheth NU;Bradley S;Bigbee J;Pandey A;Williams RW;Wolstenholme JT;Miles MF
酒精中毒是一种复杂的行为障碍，其特征是失去对限制摄入的控制，并逐渐强迫寻找和消耗乙醇。先前的研究表明，与药物使用升级相关的特征行为至少部分是由乙醇引起的影响突触可塑性的基因表达变化引起的。这一假设隐含着对新蛋白合成和突触重构的依赖。已经确定mRNA可以被转运到远端树突，在那里它可以进行局部翻译。目前尚不清楚突触转录组的这种调节是否有助于乙醇诱导的突触可塑性。使用乙醇诱导的行为致敏作为神经可塑性模型，我们研究了反复暴露于乙醇是否会改变突触转录组，从而促进随后乙醇诱发的运动活动增加的机制。在急性乙醇或乙醇致敏的DBA/2J小鼠额极突触体上进行RNAseq谱分析，以富集突触mRNA。基因组分析显示，在突触和细胞质部分中富集的mRNA具有不同的功能类别，这与它们在突触功能中的作用一致。与急性乙醇暴露相比，乙醇致敏对突触定位基因数量的调节超过两倍。被乙醇致敏选择性干扰的突触生物学过程包括蛋白质折叠和修饰以及线粒体呼吸功能，这表明反复的乙醇暴露改变了突触能量的产生和新翻译蛋白质的加工。此外，在突触和非突触细胞部分中，乙醇致敏后显着的外显子使用差异，在急性乙醇暴露后几乎没有扰动。乙醇敏化后突触外显子使用的改变强烈影响与RNA加工和稳定性、翻译调控和突触功能相关的基因。这些基因也富含FMRP RNA结合蛋白的靶标，并且包含与其他已知RNA结合蛋白相关的一致序列基序，这表明乙醇增敏改变了选择性mRNA运输机制。本研究为进一步探讨乙醇在突触转录组修饰和突触可塑性改变中的作用奠定了基础。
Alcoholism is a complex behavioral disorder characterized by loss of control in limiting intake, and progressive compulsion to seek and consume ethanol. Prior studies have suggested that the characteristic behaviors associated with escalation of drug use are caused, at least in part, by ethanol-evoked changes in gene expression affecting synaptic plasticity. Implicit in this hypothesis is a dependence on new protein synthesis and remodeling at the synapse. It is well established that mRNA can be transported to distal dendritic processes, where it can undergo localized translation. It is unknown whether such modulation of the synaptic transcriptome might contribute to ethanol-induced synaptic plasticity. Using ethanol-induced behavioral sensitization as a model of neuroplasticity, we investigated whether repeated exposure to ethanol altered the synaptic transcriptome, contributing to mechanisms underlying subsequent increases in ethanol-evoked locomotor activity. RNAseq profiling of DBA/2J mice subjected to acute ethanol or ethanol-induced behavioral sensitization was performed on frontal pole synaptoneurosomes to enrich for synaptic mRNA. Genomic profiling showed distinct functional classes of mRNA enriched in the synaptic vs. cytosolic fractions, consistent with their role in synaptic function. Ethanol sensitization regulated more than twice the number of synaptic localized genes compared to acute ethanol exposure. Synaptic biological processes selectively perturbed by ethanol sensitization included protein folding and modification as well as and mitochondrial respiratory function, suggesting repeated ethanol exposure alters synaptic energy production and the processing of newly translated proteins. Additionally, marked differential exon usage followed ethanol sensitization in both synaptic and non-synaptic cellular fractions, with little to no perturbation following acute ethanol exposure. Altered synaptic exon usage following ethanol sensitization strongly affected genes related to RNA processing and stability, translational regulation, and synaptic function. These genes were also enriched for targets of the FMRP RNA-binding protein and contained consensus sequence motifs related to other known RNA binding proteins, suggesting that ethanol sensitization altered selective mRNA trafficking mechanisms. This study provides a foundation for investigating the role of ethanol in modifying the synaptic transcriptome and inducing changes in synaptic plasticity.