异氟烷对小鼠海马和大脑皮层中RORα、Rev-erbα基因转录及节律相位的调控作用

Isoflurane anesthesia regulates transcription of RORαand Rev-erbαgenes and their circadian rhythm changes in the hippocampus and cerebral cortex of mice

目的探讨异氟烷麻醉对小鼠海马和大脑皮层中时钟基因RORα、Rev-erbα的转录水平及节律相位的影响。方法将36只7周龄雄性C57BL/6J小鼠按随机数字表法分为正常对照组与麻醉组(n=18),并于12 h光照/12 h黑暗环境中持续适应1周。麻醉组于实验前一晚22:00 pm起以1.2%异氟烷麻醉维持6 h。麻醉结束4 h后,以8:00 am光照时间为授权时间起点(ZT0),并每间隔8小时(ZT8、ZT16、ZT24、ZT32、ZT40)采集2组小鼠的大脑皮层和海马标本,应用实时荧光定量PCR(RT-qPCR)检测RORα、Rev-erbαmRNA的表达,以及采用Chronos-Fit软件进行RORα、Rev-erbαmRNA表达的余弦曲线节律分析。结果组间因素主效应分析显示,与正常对照组相比,麻醉组小鼠海马中RORαmRNA的表达明显下降,大脑皮层中RORαmRNA的表达明显上升,大脑皮层中Rev-erbαmRNA的表达明显下降,差异均有统计学意义(P<0.05)。正常对照组小鼠海马和大脑皮层中RORα、Rev-erbαmRNA的表达呈现周期约24 h的节律性,而麻醉组小鼠海马中RORαmRNA的峰值相位时间较正常对照组向右偏移5.41 h,Rev-erbαmRNA的峰值相位时间向左偏移0.89 h;大脑皮层中RORαmRNA的峰值相位时间向右偏移0.35 h,Rev-erbαmRNA的峰值相位时间向左偏移0.56 h。结论异氟烷麻醉可引起小鼠海马及大脑皮层中RORα、Rev-erbα基因的转录水平及节律相位发生改变。

Objective To investigate the effects of isoflurane anesthesia on the transcription levels of clock genes RORαand Rev-erbαand their circadian rhythm changes in the hippocampus and cerebral cortex of mice.Methods Thirty-six 7-week-old male C57BL/6J mice were divided into control group and isoflurane anesthesia group(n=18)according to random number table method.They were subjected to 12 h light/12 h dark environment for 1 week.Mice in the isoflurane anesthesia group were anesthetised with 1.2%isoflurane at 22:00 pm on the night before the experiment for 6 h;4 h after anesthesia,the light time of 8:00 am was taken as the zeitgeber time(ZT0),and then,every 8 h was taken as the recorded time(ZT8,ZT16,ZT24,ZT32 and ZT40).The RORαand Rev-erbαmRNA expressions were measured by real-time fluorescent quantitative PCR(RT-qPCR)at each time point in the cerebral cortex and hippocampus of the two groups.The cosine curves of RORαand Rev-erbαmRNA expressions were analyzed by Chronos-Fit software.Results As compared with the control group,the isoflurane anesthesia group had significantly down-regulated RORαmRNA expression in the hippocampus,significantly up-regulated RORαmRNA expression in the cerebral cortex,and significantly down-regulated Rev-erbαmRNA expression in the cerebral cortex(P<0.05).The RORαand Rev-erbαmRNA expressions in the hippocampus and cerebral cortex of the control group showed a rhythmic cycle of about 24 h;while the circadian rhythm of RORαmRNA shifted to the right by 5.41 h,and the circadian rhythm of Rev-erbαmRNA shifted to the left by 0.89 h in the hippocampus of the isoflurane anesthesia group.The peak circadian rhythm of RORαmRNA shifted to the right by 0.35 h,and the peak circadian rhythm of Rev-erbαmRNA shifted to the left by 0.56 h in the cerebral cortex of the isoflurane anesthesia group.Conclusion Isoflurane anesthesia can induce the changes of RORαand Rev-erbαtranscription levels and circadian rhythm changes in the hippocampus and cerebral cortex of mice.