Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands; SEIN - Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands.
Department of (Neuro)Pathology, Academic Center, University of the Netherlands, The Netherlands.
Neurobiol Dis. 2014 Feb;62:508-20. doi: 10.1016/j.nbd.2013.10.026. Epub 2013 Oct 31.
Since aberrant miRNA expression has been implicated in numerous brain diseases, we studied miRNA expression and miRNA regulation of important signaling pathways during temporal lobe epileptogenesis in order to identify possible targets for epilepsy therapy. The temporal profile of miRNA expression was analyzed in three brain regions (CA1; dentate gyrus, DG; parahippocampal cortex, PHC) associated with epileptogenesis in a rat model for temporal lobe epilepsy. Tissue was obtained after electrically-induced status epilepticus (SE) at 1day (n=5), 1week (n=5) and 3-4months (n=5), and compared with control tissue (n=10) using the Exiqon microRNA arrays which contain capture probes targeting all miRNAs for rat (p<0.01, and a 1.5 fold up- or downregulation). Expression of three blood plasma miRNAs from the same group of rats was also investigated in rats in order to determine whether plasma miRNAs could serve as potential biomarkers of the epileptogenic process. Molecular pathways potentially altered by the expression of multiple miRNAs were identified using a web-based algorithm, DIANA. In CA1 and DG, more upregulated than downregulated miRNAs were present during each stage after SE. The highest numbers of upregulated miRNAs were encountered during the chronic stage in the DG. In PHC, a high number of downregulated miRNAs were detected. Key pathways involved, based upon quantitatively altered miRNA expression were: axon guidance, MAPK signaling pathway, focal adhesion, TGFβ, ErbB-, Wnt- and mTOR signaling, and regulation of actin skeleton. Expression of plasma miRNAs was differentially regulated after induction of SE. This study identified several signaling pathways possibly involved in temporal lobe epileptogenesis, not previously indicated by RNA microarray studies. These include miRNAs that regulate the ErbB and Wnt pathways and focal adhesion, which may represent interesting new targets for therapeutic interventions.
由于异常的 miRNA 表达与许多脑部疾病有关,我们研究了颞叶癫痫形成过程中重要信号通路的 miRNA 表达和 miRNA 调控,以确定癫痫治疗的可能靶点。在颞叶癫痫大鼠模型中,我们分析了三个与癫痫形成相关的脑区(CA1;齿状回,DG;海马旁皮质,PHC)的 miRNA 表达时间谱。在电诱导癫痫持续状态(SE)后 1 天(n=5)、1 周(n=5)和 3-4 个月(n=5)获得组织,并与对照组组织(n=10)进行比较,使用包含针对大鼠所有 miRNA 的捕获探针的 Exiqon microRNA 阵列(p<0.01,上调或下调 1.5 倍)。还研究了来自同一组大鼠的三种血浆 miRNA 的表达,以确定血浆 miRNA 是否可以作为癫痫形成过程的潜在生物标志物。使用基于网络的算法 DIANA 鉴定了可能因多种 miRNA 表达而改变的分子途径。在 SE 后每个阶段,CA1 和 DG 中上调的 miRNA 多于下调的 miRNA。DG 中的慢性阶段遇到的上调 miRNA 数量最多。在 PHC 中,检测到大量下调的 miRNA。基于定量改变的 miRNA 表达,涉及的关键途径包括:轴突导向、MAPK 信号通路、焦点黏附、TGFβ、ErbB-、Wnt 和 mTOR 信号通路以及肌动蛋白骨架调节。SE 诱导后,血浆 miRNA 的表达发生差异调节。这项研究确定了几个可能参与颞叶癫痫形成的信号通路,这些通路以前没有被 RNA 微阵列研究表明。其中包括调节 ErbB 和 Wnt 途径以及焦点黏附的 miRNA,它们可能代表有前途的新治疗靶点。