慢性应激对大鼠下丘脑CRHR1基因启动子区域DNA甲基化的作用

Effect of Chronic Stress on DNA Methylation of Hypothalamic CRHR1 Gene Promoter in Rats

目的:研究慢性应激所致的动物下丘脑促肾上腺皮质激素释放激素受体1(CRHR1)表达和基因启动子区域甲基化状态关系。方法:将大鼠随机分为抑郁组和对照组各9只,抑郁组进行21d的慢性不可预见性温和应激。进行行为学观察,用荧光定量PCR、蛋白免疫印迹和亚硫酸氢盐修饰后测序分别检测mRNA及蛋白质表达和DNA甲基化。结果:抑郁组行为学有所改变,mRNA及蛋白质表达升高,均与对照组有显著差异,而DNA甲基化没有明显不同。结论:慢性应激后,CRHR1表达上调,但其非由DNA甲基化机制调控。

Objective： To investigate behavioral changes and alterations of mRNA and protein of hypothalamic CRHR1 and the methylation status of its promoter induced by chronic and unpredictable mild stress（CUMS）.Methods： Eighteen rats were randomly divided into two groups,and in one group,9 rats exposed to 21 consecutive days of CUMS as depression model.The expression of mRNA of CRHR1 was measured by real-time quantitative PCR and protein expression was determined by Western blot,respectively.The DNA methylation status of CRHR1 promoter was assayed by bisulfite modified DNA sequencing.Results： The sugar consumption in the stress group were significantly less than that respectively in the control.The total distance,speed and rearing significantly reduced in the stress group through the open field test.The expression of mRNA and protein of CRHR1 in the stress group was significantly higher than that in the control group.The status of DNA methylation of the promoter of CRHR1 gene had no significant difference.Conclusion： These findings provide evidence that rats exposed to stress show up-regulated expression of CRHR1,and it seems that the expression is not induced by the DNA methylation mechanism.