细胞复制性衰老及早衰过程中组蛋白整体乙酰化改变  

Alterations of Overall Histone Acetylation During Cellular Replicative Senescence and Premature Senescence of Human Embryonic Lung Fibroblasts

作　　者：张文娟[1] 纪卫东[1] 杨淋清[2] 杨建平[1] 许玉玲[1] 徐薇[1] 庄志雄[2] 

机构地区：[1]中山大学公共卫生学院预防医学系,广州市510080 [2]深圳市疾病预防控制中心毒理研究室,广东省深圳市518020

出　　处：《医学分子生物学杂志》2008年第5期387-392,共6页Journal of Medical Molecular Biology

基　　金：国家自然科学基金(No.30571592;30630055;30700673);国家重点基础研究发展规划项目(973计划)(No.2002CB512903);广东省自然科学基金项目(No.04002730);深圳市科技计划重点资助项目(No.JH200505300503A)~~

摘　　要：目的检测人胚肺成纤维细胞复制性衰老及过氧化氢诱导细胞早衰过程中组蛋白整体乙酰化修饰的改变。方法应用细胞免疫荧光实验观察组蛋白乙酰化水平变化,并基于ELISA样反应方法检测组蛋白总体去乙酰化酶的活性变化,荧光定量PCR检测乙酰化酶mRNA表达,荧光定量PCR和Western印迹检测去乙酰化酶表达变化及曲古霉素A对相应酶表达的影响。结果在细胞复制性衰老及细胞早衰过程中,组蛋白H3和H4整体乙酰化水平逐渐下降;去乙酰化酶活性逐渐降低;与年轻细胞组相比,中年细胞与复制性衰老细胞组P300表达下降;中年细胞组PCAF稍升高,复制性衰老细胞组降低;早衰起始组P300和PCAF均升高,早衰持续组P300降低;中年细胞组HDAC1表达稍降低;复制性衰老细胞组HDAC2稍降低;而HDAC3均降低;早衰起始组HDAC1,HDAC3有不同程度升高;早衰持续组HDAC2,HDAC3降低显著,而HDAC1明显升高。曲古霉素A诱导P300,PCAF表达,而降低HDAC1,HDAC2和HDAC3表达。结论组蛋白H3和H4整体低乙酰化是衰老细胞的伴随状态;细胞复制性衰老与过氧化氢诱导的早衰内在调控机制存在差别。Objective This study was aimed to examine changes of whole histone acetylation in human embryonic lung fibroblasts （HEFs） undergoing cellular replicative senescence and premature senescence induced by hydrogen peroxide. Methods Overall histone acetylation level was detected by immunofluorescence assay. The activity of deacetylases was measured with an ELISA-like reaction. The level of mRNA expressions of acetylases was determined by Q-PCR, and the expression of deacetylases was analyzed by both Q-PCR and western blot. The changes of acetylases and deacetylases induced by TSA were evaluated. Results During cellular senescence, the overall acetylation level of histone H3 and H4 was reduced gradually, and the activity of HDACs was also down-regulated gradually. The mRNA expression of P300 was decreased in mid-aged or replicative senescent cells compared with young cells, while PCAF was slightly up-regulated in mid-aged cells and down- regulated in replicative senescent cells. Both P300 and PCAF were increasingly expressed in premature senescence initiation group, whereas P300 in premature senescence persistence group was low- ered. HDAC1 in mid-aged cells and HDAC2 in replicative senescent cells were observed to be slightly decreased, while HDAC3 was decreased in both mid-aged and replicative senescent cells. In premature senescence initiation group, HDAC1 and HDAC3 were increased to different extent. In premature senescence persistence group, both HDAC2 and HDAC3 were decreased, whereas HDAC1 was obviously increased. TSA induced mRNA expression of P300 and PCAF, but reduced the expression of HDAC2 and HDAC3. Conclusion Cellular senescence is accompanied with overall hypoacetylation of H3 and H4. Differential regulation mechanisms exist between two types of senescence-replicative senescence and premature senescence.

关 键 词：细胞衰老 组蛋白乙酰化酶 去乙酰化酶 过氧化氢 

分 类 号：R349.5[医药卫生—基础医学]