γ-氨基丁酸对昼夜节律紊乱型小鼠睡眠干预研究

SLEEP INTERVENTION BY GAMMA-AMINOBUTYRIC ACID IN MICE WITH CIRCADIAN RHYTHM DISORDER

目的探究γ-氨基丁酸(GABA)对昼夜节律紊乱小鼠睡眠的改善作用,并探讨其可能的作用机制。方法66只C57BL/6J雄性小鼠随机分为对照组(CON)、昼夜节律紊乱组(CRD)以及GABA干预组(150 mg/kg,GABA)。分别每天记录各组小鼠日间及夜间摄食量;小鼠干预处理30 d后,取其中30只小鼠进行旷场实验及戊巴比妥钠诱导睡眠实验;36只小鼠分别于造模结束后第2dZT0点与ZT12点处死。通过旷场实验,探究小鼠的行为学变化;采用戊巴比妥钠诱导睡眠实验探究GABA对昼夜节律紊乱小鼠的促睡眠效果;通过检测小鼠下丘脑时钟基因及前额叶皮层MEK、ERK蛋白表达,探讨GABA改善小鼠睡眠损伤的作用机制。结果GABA可提高昼夜节律紊乱小鼠夜间摄食量,降低日间摄食量;GABA组小鼠在旷场中的运动总路程、平均速度、静止总时间及中央停留次数分别为2401.40 cm、8.04 cm/s、155.70 s、2次,与CRD组有显著性差异(P<0.001),与CON组无显著性差异(P>0.05);同时GABA可延长小鼠睡眠时间(P<0.05),但对睡眠潜伏期无影响(P>0.05);相比于CRD组,GABA干预后可增强昼夜节律紊乱小鼠下丘脑时钟基因(Clock、Per1、Per2、Per3、Cry1、Cry2、Rev-erbα/β、Dbp、Ciart)振幅,降低前额叶皮层ERK表达(P<0.001),同时降低MEK、ERK1/2磷酸化水平。结论外源性GABA可能通过抑制MEK、ERK磷酸化水平,同时增强下丘脑时钟基因振幅表达,进而改善昼夜节律紊乱小鼠睡眠。[营养学报,2023,45(2):139-147]

Objective To investigate the effect of y-aminobutyric acid(GABA)on sleep improvement in mice with circadian rhythm disorder and explore its possible mechanism.Methods Sixty-six male C57BL/6J mice were randomly assigned to control group(CON),circadian rhythm disorder group(CRD)and GABA intervention group(GABA 150 mg/kg by gavage).The daily and nocturnal food intakes of mice were recorded.After 30 days,30 mice were taken out for open-field test and pentobarbital sodium-induced sleep experiment.Thirty-six mice were sacrificed 2 days after the last shift in light-dark cycle at ZTO and ZT12.The behavioral changes of mice were assessed by open-field test.Pentobarbital sodium-induced sleep experiment was used to investigate the sleep-promoting effect of GABA on mice with circadian rhythm disorder.To explore the mechanism involved,the clock gene expression in hypothalamus and the protein expression of MEK and ERK in prefrontal cortex were detected.Results GABA could increase the nocturnal food intake and reduce daytime food intake in CRD group.In open-field test,the total distance traveled,average speed,total resting time and center zone entries in the GABA group were 2,401.40 cm,8.04 cm/s,155.70 s and 2 times respectively,which were significantly different from those in the CRD group(P<0.001),but not different from those in the CON group(P>0.05).At the same time,GABA could prolong the sleep duration in CRD group(P<0.05),but had no effect on sleep latency(P>0.05).Compared with the CRD group,GABA increased the amplitude of clock gene expression levels(Clock,Perl,Per2,Per3,Cryl,Cry2,Rev-erba/β,Dbp,Ciart)in hypothalamus.Conversely,GABA could decrease the expression of ERK(P<0.001)and MEK、ERK1/2 phosphorylation levels in the prefrontal cortex.Conclusion Exogenous GABA may improve sleep in mice with circadian rhythm disorder by inhibiting the phosphorylation levels of MEK and ERK and enhancing the expression amplitude of key clock genes in the hypothalamic.[ACTA NUTRIMENTA SINICA,2023,45(2):139-147]