小鼠蛛网膜下腔出血后早期大脑皮层环状RNA的表达谱研究

Expression profile of circular RNA in mouse cortex after subarachnoid hemorrhage

目的 分析小鼠蛛网膜下腔出血（SAH）后早期大脑皮层环状RNA （circRNA）及mRNA的表达谱,探讨circRNA在SAH后早期脑损伤（EBI）中的潜在作用. 方法 18只C57BL/6J雄性小鼠按随机数字表法分为假手术组及SAH组（n=9）,后者采用颈动脉内穿刺法构建SAH模型.SAH后24 h提取小鼠大脑皮层总RNA,构建cDNA文库,采用HiSeqTM 2500 User Guide测序;将所有转录本比对到小鼠基因组,分别得到circRNA及mRNA的表达谱;筛选出显著差异表达的circRNA及mRNA,进行GO富集、KEGG通路分析及circRNA靶微小RNA（miRNA）预测;运用逆转录-实时定量PCR（RT-qPCR）技术对测序结果进行验证. 结果 在小鼠SAH后早期大脑皮层中,显著差异表达的circRNA共26种,其中6种上调,20种下调;显著差异表达的mRNA共804种,其中396种上调,408种下调.生物信息技术分析提示显著差异表达的mRNA涉及神经突触可塑性调节、炎症与免疫反应等多种生物学途径,部分显著差异表达的circRNA可结合不同的miRNA.随机挑选的4条circRNA（circFoxj3、circ Setbp1、circArpp21、circ2010111I01Rik）的变化趋势经RT-qPCR技术验证与测序结果一致. 结论 小鼠SAH后早期大脑皮层circRNA的表达谱已发生变化,显著差异表达的circRNA广泛参与调控SAH后EBI的病理过程,其或许可成为SAH诊治及预后判断的新靶点.

Objective To explore the altered expression of circular RNA （circRNA） and mRNA in the mouse cortex in the early phase of subarachnoid hemorrhage （SAH） and possible biological functions of the circRNA in early brain injury （EBI）.Methods A total of 18 C57BL/6J male mice were randomly divided into a sham and a SAH group （n=9）.SAH models were prepared by endovascular perforation.Total RNAs of brain samples were extracted to construct the cDNA library 24 h after operation.RNA-sequencing （RNA-seq） was carried out by HiSeqTM 2500 User Guide and followed by RT-qPCR for confirmation.Reads were aligned to the mouse transcriptome to obtain expression profiles ofcircRNA and mRNA.Bioinformatic study included GO analysis,KEGG pathway analysis and forecast of targeted miRNA of circRNA.Results A total of 26 circRNA （6 up-regulated and 20 down-regulated） and 804 mRNA （396 up-regulated and 408 down-regulated） were significantly changed.These altered mRNA were mainly related to regulation of neuronal synaptic plasticity,inflammatory and immune response.Bioinformatics showed that some significantly altered circRNA contained binding sites for many miRNA.The RT-qPCR analysis of 4 randomly selected circRNA （circFoxj3,circSetbp1,circArpp21 and circ2010111 I01Rik） confirmed the accuracy of RNA-seq.Conclusions SAH alters the expression of circRNA in mouse cortex and the differentially expressed circRNA may be involved in regulation of EBI following SAH,promising a potential therapeutic target for the diagnosis,treatment and prognosis of SAH.