母爱剥夺对大鼠行为及纹状体前列腺凋亡反应蛋白基因表达的影响

Maternal deprivation effect on behavior and prostate apoptosis response-4 expression in rats

目的 研究早期母爱剥夺对大鼠成年后的抑郁水平及纹状体前列腺凋亡反应蛋白（par-4）表达的影响，以及甲基化是否参与par-4基因表达的调控。方法按照随机数字表法，将新生幼鼠按窝分为母爱剥夺组和对照组，每组17只；母爱剥夺组仔鼠在出生后的第1～14天，每天接受6h母子分离，对照组不接受任何实验处理；13周龄时，采用强迫游泳实验和糖水偏爱实验测定大鼠的抑郁水平，采用实时定量聚合酶链反应检测纹状体par-4及多巴胺受体2（DRD2）信使RNA（mRNA）表达水平，采用亚硫酸盐测序法检测par-4基因启动子区DNA甲基化水平。结果母爱剥夺组大鼠漂浮时间[（152．80±74．21）S]较对照组[（63．80±80．55）s]延长，糖水偏爱率（0．454-0．23）较对照组（0．69±0．25）降低，差异均有统计学意义（t=2．79，P〈0．05；t=-2．57，P〈0．05）；母爱剥夺组大鼠纹状体内par-4（0．02±0．02）及DRD2mRNA表达量（0．11±0．09）分别为对照组[（0．04±0．02）、（0．32±0．21）]的0．53倍和0．31倍；母爱剥夺组大鼠par-4基因启动子区DNA甲基化水平与对照组相比差异无统计学意义（t=-0．748，P〉0．05）。结论母爱剥夺能引发大鼠抑郁样行为表现，并能抑制纹状体par-4的表达，基因甲基化可能不是其调控机制。

Objective To study the effect of maternal deprivation on the depressive behaviors and the expression of prostate apoptosis response-4 （par-4） in adult rats＇ striatum, and to explore whether DNA methylaion be involved in the regulatory mechanism of par-4 expression. Methods Newborn rats were randomly divided into two groups, the maternal deprivation group rats （n = 17 ） were deprived from their mother 6 hours per day from postnatal day 1 to 14, while the control group rats （ n = 17 ） received no experimental handle. When they grew up to thirteen weeks, their depressive level was assessed with forced swimming test and sucrose consumption test,the mRNA expression of par-4 and DRD2 in rats＇ striatum was detected by real-time Polymerase Chain Reaction （real-time PCR）, and the DNA methylafion level of par-4 was determined by bisulfated DNA sequencing. Results The float time of maternal deprivation rats [ （ 152.80 ± 74. 21 ） s ] was longer than the control rats [ （63.80±80. 55 ） s ] （ t = 2. 79, P 〈 0. 05 ）, and the sucrose preference rate of maternal deprivation rats （ 0. 45 ±0. 23 ） was reduced compared with the control rats （0. 69 ± 0. 25 ） （ t = - 2.57, P 〈 0. 05 ）. The fold changes of par-4 （0.02± 0. 02 ） and DRD2 （0. 11 ± 0. 09） mRNA expression in maternal deprivation rats compared to control rats [ （0. 04 ±0. 02 ）, （0. 32 ±0. 21 ） ] were 0. 53 and 0. 31 respectively. However, there was no significant difference between two groups in methylation level of par-4 promoter region （ t = - 0. 748, P 〉 0. 05 ）. Conclusion Maternal deprivation could induce the depressive behavior of rats and influence the expression of par-4, but DNA methylation may not be involved in the regulatory mechanism.