基于RNA测序的尼古丁影响下大鼠前额叶皮质的基因表达分析

Analysis of Gene Expression through RNA Sequencing in Prefrontal Cortex of NicotineTreated Rats

目的研究尼古丁处理对大鼠前额叶皮质(PFC)中基因表达的影响。方法 24只F344大鼠随机分为实验组和对照组,每组12只,分别注射尼古丁水溶液或生理盐水17 d。药物处理结束后,从每只大鼠大脑采集PFC组织。然后采用RNA测序(RNA-Seq)技术对24只大鼠大脑PFC区域的mRNA进行测序,测出的读段利用Bowtie、Tophat及Cufflinks等生物信息学工具比对到参考基因组上并测量转录子表达水平。随后采用统计学方法确定表达水平在实验组和对照组发生显著变化的基因,并进一步分析了这些基因的功能类别及与其相关的生化通路。结果通过分析每个转录子在处理组和对照组的表达水平,确定了在尼古丁影响下的表达水平发生显著变化的基因885个。在这些基因中,与多个Gene Ontology生物学过程如G蛋白偶联受体信号通路、蛋白质泛素化和神经递质吸收等,以及生化通路如胰岛素信号、阿尔茨海默病和长时程增强等相关的基因均显著富集。结论尼古丁处理可能调节大脑PFC区域神经信号传导和能量代谢等生物学过程。

Objective To investigate the effects of nicotine on the gene expression profile in prefrontal cortex （PFC） region of rats. Methods Twenty-four adult male F344 rats were randomly divided into treatment group and control group, with 12 animals in each group, Animals in treatment group were injected with nicotine solution while those in control group were given physiological saline for 17 days. At the end of drug administration, the tissue of PFC region was sliced from the brain of each animal. RNA sequencing （RNA-Seq） was utilized to analyze the gene expression profile in PFC of each animal. Bioinformatics tools including Bowtie, Tophat and Cufflinks were used to map the sequencing reads to the reference genome of rat, and to measure the relative expression level of each transcript. Genes whose expression levels were significantly differ- ent between the two groups were identified. The functional categories and the biochemical pathways associated with these genes were further analyzed. Results By comparing the expression level of each transcript between two groups, 885 signifi- cantly differentially expressed genes were identified. These genes were enriched in multiple Gene Ontology Biological Pro- cess categories （e.g., G protein coupled receptor protein signaling pathway, protein ubiquitination, and neurotransmitter up- take） and biological pathways （e.g., insulin signaling pathway, Alzheimer＇s disease, and long term potentiation）. Conclu- sion Nicotine treatment may regulate signaling transduction, energy metabolism and other biological processes in PFC of rat brain.