| Objectives:The purpose of this study was to observe the changes of cognitive behavior after REM sleep deprivation in mice and explore the effects of REM sleep deprivation on cognitive behavior.Observe the effect of REM sleep deprivation on protein expression and gene expression of IGF-1 in mice hippocampus,then observe the protein expression changes of p-Akt,p-GSK3?,bcl-2,caspase-9 and the gene expression level of inflammatory factors(TNF-?,IL-1?,IL-6).Further explore the inflammatory mechanism of the IGF-1/PI3K/Akt pathway in mice hippocampus and the possible mechanism of cognitive impairment after REM sleep deprivation.Method:Adult C57BL/6J mice aged 8 weeks were randomly divided into four groups,6 individuals per group: blank control group(CC group): fed in adaptive environment for 1 week;REM sleep deprivation 5 days group(SD group):fed in adaptive environment for 1 week,and REM sleep deprivation for 5 days with modified multiple platform method;REM sleep deprivation for 5 days + IGF-1 group(SD +IGF-1 group):fed in adaptive environment for 1 week,REM sleep deprivation for 5 days with modified multiple platform method,and intraperitoneal injection RhIGF-1(50ug/kg)at 17:00 every day during sleep deprivation for 5 consecutive days;REM sleep deprivation for 5 days+PBS group(SD +PBS groups): fed in adaptive environment for 1 week,REM sleep deprivation for 5 days with modified multiple platform method,and intraperitoneal injection PBS(50ug/kg)at 17:00 every day during sleep deprivation for 5 consecutive days.Morris water maze navigation training was conducted on all mice 4 days before modeling,and the space exploration experiment was conducted 5 days after sleep deprivation,and the mice were put to death after testing.All experimental animals were guaranteed 12 hours of light(9:00-21:00)and 12 hours of darkness(21:00-9:00)before being killed.The expression level of IGF-1 in mice hippocampus was determined by Elisa,and the expression level of IGF-1 gene in mice hippocampus was detected by RT-qPCR.The expression level of p-Akt,Akt,p-GSK3?,GSK3?,Bcl-2 and Caspase-9 in the micehippocampus of each group were determined by western-blot.The expression level of TNF-?,IL-1?,IL-6 in mice hippocampus of each group were determined by RT-qPCR.Results:1.The behavioral test results showed that,In the place navigationtraining,the fifth day escape latency of SD group was increased compared with the CC group,and the difference was statistically significant(p=0.005),and the fifth day escape latency of SD+ IGF-1 group was decreased compared with the SD group and the SD+PBS group,and the differences were statistically significant(p=0.01,p=0.022).In the space exploration experiment,compared with the CC group,the time in the target quadrant of the SD group was shortened,and the number of times across the platform was reduced,and the differences were statistically significant(p=0.035,p=0.000).Compared with the SD group,the mice in the SD+ IGF-1 group were in the target quadrant for longer and crossed the platform for more times,the differences were statistically significant(p=0.041,p=0.000).2.The results of Elisa showed that compared with the CC group,the expression of IGF-1 protein in the mice hippocampus of the SD group was decreased,the difference was statistically significant(p=0.001).Compared with SD group,the expression of IGF-1 protein in the mice hippocampus in SD+ IGF-1 group was increased,the difference was statistically significant(p=0.039).Real-time fluorescence quantitative PCR(RT-qPCR)results showed that compared with the CC group,the expression of IGF-1 mRNA in the mice hippocampus of the SD group was decreased,the difference was statistically significant(p=0.004).3.Western blot results showed that,compared with the CC group,the hippocampal p-Akt expression was decreased and p-GSK3? expression was increased in the SD group,the differences were statistically significant(p=0.000,p=0.006),Bcl-2expression was decreased,and Caspase-9 expression was increased,the differences were statistically significant(p=0.001,p=0.002).Compared with the SD group,the p-Akt expression and p-GSK3? expression in mice hippocampus of the SD+IGF-1group was increased,the differences were statistically significant(p=0.000,p=0.001),the bcl-2 expression was increased and caspase-9 expression was decreased,the differences were statistically significant(p=0.000,p=0.001).4.Real-time fluorescence quantitative PCR(RT-qPCR)results showed that,compared with the CC group,the mRNA expression level of TNF-?,IL-1? and IL-6in the mice hippocampus of the SD group was increased,the differences were statistically significant(p=0.002,p=0.008,p= 0.000).Compared with SD group,the mRNA expression level of TNF-?,IL-1? and IL-6 in the mice hippocampus of the SD+ IGF-1 group was decreased,the differences were statistically significant(p=0.001,p=0.008,p= 0.000).Conclusions:1.After REM sleep deprivation,IGF-1 expression was decreased in mice hippocampus and cognitive function of mice was decreased.Exogenous supplementation of IGF-1 can improve the cognitive impairment caused by REM sleep deprivation,suggesting that the decrease of IGF-1 is related to the cognitive impairment after REM sleep deprivation in mice.2.The expression of IGF-1 and p-Akt was decreased and The expression of p-GSK3? was increased in the hippocampus of mice after REM sleep deprivation,and the expression of p-Akt and p-GSK3? was increased after the supplementation of IGF-1,suggesting that IGF-1 is involved in the regulation of PI3K/Akt/GSK3?signal transduction pathway.3.After REM sleep deprivation,the expression of pro-apoptosis related factor Caspase-9 was increased,and the expression of anti-apoptosis factor Bcl-2 was decreased in mice hippocampus.After the supplementation of IGF-1,the expression of Bcl-2 was increased,and the expression of Caspase-9 was decreased,indicating that the IGF-1/PI3K/Akt signaling pathway was involved in the expression of apoptosis related factors.4.The expression of proinflammatory factors TNF-?,IL-1? and IL-6 in the mice hippocampus were increased after REM sleep deprivation in mice,while the expression of proinflammatory factors TNF-?,IL-1? and IL-6 were decreased after the supplementation of IGF-1,suggesting that the IGF-1/PI3K/Akt signaling pathway was involved in the expression of inflammatory factors after REM sleep deprivation in mice.To sum up,IGF-1/PI3K/Akt pathway in mouse hippocampus may be one of themechanisms of cognitive function changes and inflammatory damage after REM sleep deprivation,and IGF-1 may be the intervention target of cognitive function damage after sleep deprivation,thus providing theoretical basis for the treatment of cognitive function damage after sleep deprivation. |
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