基于脑组织转录组整合分析探索大鼠氯胺酮的麻醉机制

Transcriptome-based integrated analysis of the anesthetic mechanism of ketamine in rat brain

目的通过观察氯胺酮麻醉对大鼠大脑皮质转录组表达的影响,探讨其可能的麻醉机制。方法选择5~6周龄雄性SD大鼠6只,采用完全随机法分为氯胺酮组(KET组)和对照组(Ctrl组),每组3只。分别腹腔注射麻醉剂量氯胺酮(50 mg/kg)或等体积生理盐水后30 min,提取大脑皮质进行mRNA测序(mRNA sequencing,RNA-seq),筛选差异表达基因。使用实时荧光定量聚合酶链反应(real time fluorescent quantitative polymerase chain reaction,RT-qPCR)进行验证,并通过基因本体(gene ontology,GO)分析、京都基因和基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)通路分析和蛋白质-蛋白质相互作用(protein-protein interaction,PPI)网络分析鉴定差异表达基因涉及的相关功能变化。结果在确定样本质量合格后,高通量测序检测出氯胺酮麻醉后大鼠皮质中70种基因显著上调,83种基因显著下调。通过GO、KEGG和PPI分析发现,氯胺酮麻醉过程中发生显著变化的通路主要有5-羟色胺能突触、核糖体和光传导3种,分别对应5-羟色胺系统、神经内分泌系统和视觉系统。结论氯胺酮麻醉后大鼠大脑皮质中mRNA表达显著改变。相关的功能变化分析提示,5-羟色胺系统、神经内分泌系统和视觉系统可能参与了氯胺酮的麻醉调控。

Objective To observe the effect of ketamine anesthesia on the expression of transcriptome in rat brain tissue and to explore its possible anesthetic mechanism.Methods A total of 6 SD rats(male,aged 5‒6 weeks)were divided into two groups according to complete randomization(n=3):a ketamine group(KET group)and a control group(Ctrl group).Then,30 min after intraperitoneal injection of ketamine(50 mg/kg)or the same volume of normal saline,the cerebral cortex was collected for mRNA sequencing(RNA-seq)to screen differentially expressed genes.Real-time fluorescent quantitative polymerase chain reaction(RT-qPCR)was used for verification.The functional changes of differentially expressed genes were identified through gene ontology(GO)analysis,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis and protein-protein interaction(PPI)analysis..Results The quality of the samples were confirmed.High-throughput sequencing results showed that 70 genes were significantly up-regulated and 83 genes were significantly down-regulated in the cortex of rats after ketamine anesthesia.GO,KEGG and PPI analyses indicated that the pathways that significantly changed during ketamine anesthesia included 5-serotonergic synapse,ribosome and photoconduction corresponding to 5-hydroxytryptamine system,neuroendocrine system and visual system respectively.Conclusions The expression of mRNA in rat brain significantly change after ketamine anesthesia.The analysis of related functional changes suggests that 5-serotonin system,neuroendocrine system and visual system may be involved in the anesthetic regulation of ketamine.