快速眼动睡眠剥夺诱导大鼠皮质和海马及延髓caspase-12的表达

目的观察不同时间快速眼动睡眠剥夺(SD)对大鼠皮质、海马及延髓内质网凋亡因子caspase-12的表达影响。方法将80只雄性Wistar大鼠分为SD组(40只)、SD后恢复睡眠组(RS组,20只)、对照组(20只);其中SD组又分为SD1、3、5、7天亚组,RS组又分为RS6、12h亚组;对照组又分为实验环境对照组(TC组)和正常睡眠对照组(CC组)。采用改良多平台SD法、免疫组织化学法、Western blot及RT-PCR检测脑组织中caspase-12表达分布规律及时空变化;TUNEL法检测凋亡细胞分布。结果RT-PCR检测大鼠快速眼动SD1天caspase-12有表达并呈逐渐上升趋势,7天达高峰,RS6、12h及TC组和CC组无caspase-12表达。免疫组织化学及Western blot检测发现,SD1、3天激活的caspase-12表达增加(P<0.05),5、7天及RS组、TC组和CC组无激活的caspase-12表达。上述变化海马区最明显,皮质区次之,延髓区无改变。TUNEL检测SD1、3天凋亡细胞海马区最多(P<0.05),皮质和延髓区次之。结论SD启动了内质网凋亡通路,并随SD的终止而终止。SD可能是造成脑组织损害的机制之一,海马区对SD导致的脑损害最敏感。

REM sleep deprivation induced expression of caspase-12 in rat cortex, hippocampus and medulla

Objectives To observe the influences of sleep deprivation(SD)on the expression of caspase-12 in different brain regions.so as to investigate the possible effect of apoptosis factor during SD.Methods The modified multiple platform SD method was used to establish the REM SD model.The immunohistochemistry method,RT-PCR and Western blot technique were used to examine the distribution regularity and temporal-spatial changes of caspase-12 expression in the rat frontal cortex,hippocampus and medulla.TUNEL method was used to examine cell apoptosis in different brain regions.Results RT-PCR examination showed that expression of caspase-12 gradually increased during SD and there was no change after revival of sleep.Immunohistochemical and Western blot examinations showed that active caspase-12 increased from d 1 to d 3 after SD and no active caspase-12 existed on days 5,7.The above changes were most obvious in the hippocampus region.TUNEL examination showed that the apoptotic cells were most numerous in the hippocampus on d 1 and d 3 after SD(P<0.05).Conclusion SD switches on endoplasmic reticulum(ER)apoptosis pathway which terminates with termination of SD.SD may be one of the mechanisms of brain injury.The hippocampal region is most sensitive to the damage caused by sleep deprivation.