睡眠剥夺通过PI3K/Akt信号通路调控孕鼠下丘脑和垂体中生物钟基因的表达进而影响性激素分泌

Sleep deprivation affects sex hormones secretion by regulating the expression of the circadian clock gene in the hypothalamus and pituitary via the PI3K/Akt signaling pathway in pregnant rats

睡眠剥夺(sleep deprivation,SD)对健康有许多有害影响,超过70%的孕妇发生SD。然而,SD后性激素的变化情况及其机制尚不清楚。本研究旨在探讨SD对性激素分泌的作用及其机制。将12只怀孕Wistar大鼠分为对照(CON)组和睡眠剥夺(SD)组,每组6只。SD组孕鼠剥夺睡眠18 h,自由休息6 h,然后重复以上过程,直到分娩;CON组生活在12 h光/暗光照循环环境。用ELISA法检测血清雌二醇(estradiol,E2)和孕酮(progesterone,P4)水平,用免疫组织化学(immunohistochemistry,IHC)和逆转录-定量聚合酶链反应(reverse transcription-quantitative polymerase chain reaction,RT-qPCR)方法检测下丘脑和垂体组织生物钟基因Bmal1、Clock和Per2的表达情况,用蛋白印迹法检测下丘脑和垂体组织PI3K和Akt磷酸化水平。结果显示,和CON组相比,SD组血清E2和P4水平显著降低,下丘脑和垂体组织Bmal1、Clock和Per2的表达下调,PI3K和Akt磷酸化水平下调,但总PI3K和Akt蛋白表达水平没有明显变化。本研究结果表明,SD可能通过PI3K/Akt信号通路影响下丘脑和垂体生物钟基因的表达,进而调节性激素的分泌,提示生物钟基因在SD引起的性激素分泌改变中可能具有重要作用。

Sleep deprivation(SD)has many deleterious health effects and occurs in more than 70%of pregnant women.However,the changes in sex hormones and relevant mechanisms after SD have not been well clarified.The aim of the present study was to explore the effects of SD on the secretion of sex hormones and the underlying mechanisms.Twelve pregnant Wistar rats were divided into control(CON,n=6)and SD(n=6)groups.Pregnant rats in the SD group were deprived of sleep for 18 h,and allowed free rest for 6 h,and then the above procedures were repeated until delivery.The CON group lived in a 12 h light/dark light cycle environment.Estradiol(E2)and progesterone(P4)levels were detected by enzyme-linked immunosorbent assay(ELISA),and the expression of circadian clock genes,Bmal1,Clock and Per2,in hypothalamus and pituitary gland tissues were evaluated by immunohistochemistry(IHC)and reverse transcription-quantitative polymerase chain reaction(RT-qPCR).The PI3K and Akt phosphorylation levels in the hypothalamic and pituitary tissues were determined by Western blot.The results showed that,compared with the CON group,the SD group exhibited significantly reduced serum E2 and P4 levels,down-regulated Bmal1,Clock and Per2 expression,as well as decreased phosphorylation levels of PI3K and Akt.But there was no significant difference of the total PI3K and Akt protein expression levels between the two groups.These results suggest that SD might affect the expression of the circadian clock genes in the hypothalamus and pituitary via PI3K/Akt pathway,and subsequently regulate the secretion of sex hormones in the pregnant rats,which hints the important roles of SD-induced changes of serum sex hormone levels in the pregnant rats.