摘要
目的探讨大鼠心脏自噬昼夜节律的老年化改变及可能机制。方法随机选取健康雄性SD大鼠48只,其中6月龄大鼠24只(青年组)和26月龄大鼠24只(老年组)。观察大鼠昼夜活动习性,分别在03:00,06:00,09:00,12:00,15:00,18:00,21:00,24:00各时间点收集心脏样本,运用冷冻切片免疫荧光染色结合激光扫描共聚焦成像技术、亚细胞结构细胞核-细胞质分离技术和免疫印迹技术检测心脏自噬规律及可能调控机制。结果青年组大鼠昼伏夜出,自噬昼夜节律曲线明显,其中18:00 LC3-Ⅰ转化LC3-Ⅱ明显高于12:00,而在15:00细胞核C/EBPβ表达明显高于18:00(P<0.05);而老年组大鼠夜间及昼间均嗜睡,LC3-Ⅰ转化LC3-Ⅱ和细胞核C/EBPβ昼夜无节律性变化。结论衰老改变心脏自噬的昼夜节律,核转录因子C/EBPβ参与其调控。
Objective To study the change of rat heart circadian autophagy rhythm due to aging and its possible mechanism. Methods Forty-eight SD rats were randomly divided into 6-month old group （young group, n = 24） and 26-month old group （aged group, n = 24）. Their circadian activity was observed. Heart tissue samples were collected at 03,06,09,12,15,18,21,24 h,respectively,frozen and cut into sections. Heart circadian autophagy rhythm and its possible regulation mechanism were detected by laser scanning, confoeal imaging technique, nucleus and cytilipin separation technique and Western blot,respectively,with immunofluorescence staining. Results The rats in young group hid by day and came out by night with a significant circadian autophagy rhythm curve. The LC3- Ⅰ was converted to LC3- Ⅱ at 18 h and reached its peak at 12 h. The expression level of nucleus-C/EBP-β was significantly higher at 15 h than at 18 h（P〈0.05）. The rats in aged group were sleepy day and night. No change of circadian rhythm was observed during the conversion of LC3- Ⅰ to LC3- Ⅱ and nucleus-C/EBP-β（P〉0.05）. Conclusion Aging can change the heart circadian autophagy rhythm with involvement of nucleus-C/EBP-β in its regulation.
出处
《中华老年心脑血管病杂志》
CAS
北大核心
2012年第4期414-416,共3页
Chinese Journal of Geriatric Heart,Brain and Vessel Diseases
基金
国家自然科学基金(30960381)
关键词
昼夜节律
自噬
细胞结构
心肌缺血
circadian rhythm
autophagy
cellular structures
myocardial ischemia
