作　　者： ; ; ; ; ; ;

机构地区： 四川省疾病预防控制中心

出　　处： 《卫生研究》 2013年第5期777-782,共6页

摘　　要： 目的研究细胞复制衰老与H2O2诱导细胞早衰过程中P66SHC基因表达变化及复制衰老过程中组蛋白修饰改变。方法人胚肺成纤维细胞固定传代直至停止增殖以制备复制衰老模型,过氧化氢诱导细胞早衰模型。采用Q-PCR方法动态观察细胞复制衰老与早衰过程中P66SHC以及组蛋白乙酰化酶EP300和去乙酰化酶HDAC1的基因表达,采用染色质免疫沉淀技术观察年轻细胞与衰老细胞P66SHC基因启动子区的组蛋白修饰情况。结果 P66SHCmRNA表达与染毒剂量正相关(R=0.909,P=0.000),EP300表达与染毒剂量负相关(R=-0.922,P=0.000),HDAC1与染毒剂量不相关(R=-0.066,P=0.839)。P66SHC表达与群体倍增代数正相关(R=0.743,P=0.006),EP300表达和HDAC1表达与群体倍增代数负相关(R=-0.709,P=0.010;R=-0.599,P=0.040)。与复制衰老组相比,早衰组细胞P66SHC、EP300及HDAC1的基因表达量均有显著性差异(t=-19.733,P=0.000;t=11.103,P=0.000;t=9.728,P=0.001)。老年细胞的P66SHC基因调控区的H3组蛋白修饰丰度均降低;在转录起始点上游3.0kb处抑制基因转录的H3K9-tri-Me修饰几乎为零,选择启动子(转录起始点下游3.8kb)处的组蛋白修饰以活化转录的修饰为主。结论 P66SHC、EP300和HDAC1均可能参与细胞衰老和氧化应激诱导的细胞早衰,早衰组细胞P66SHC基因表达与复制衰老组不同;组蛋白修饰参与P66SHC的基因表达调控。 Objective To study the profile of P66^SHC expression and histone modifications in replicatively senescenct cells and oxidative-stress inducing premature senescenct cells. Methods HPF cells were continuously cultured and subcuhured in vitro to build replicative cellular model. HPF cells were treated with 200 μmol/L H202 four times to build oxidative-stress inducing premature senescenct model. Comparative Q-PCR was utilized to investigate target gene（P66^SHC ,EP300 ,HDAC1 ）expressions respectively in H2O2 treated groups and normal cell groups. Then CHIP-QPCR was conducted to analyze histone modifications of P66^SHC between young cells and aging cells. Results P66^SHC expression was positive correlation with H2O2 doses and population doubling level （PDL） （R = 0. 909, P = 0. 000 ; R = 0. 743, P = 0. 006 ） , while EP300 was negative correlation with H202 （R = - 0. 922, P = 0. 000） and both EP300 and HDAC1 were negative with PDL （R = -0. 709,P =0. 010,R = -0. 599,P =0. 040）. H3 histone modifications were declined in P66^SHC gene regulating region. H3-Ac, H3K9-Ac and H3K4-tri-Me were dominant in the upstream region of transcriptional site （ - 3.0 kb） and alternative promotor （ ＋ 3.8 kb）. Conclusion P66^SHC, EP300 and HDAC1 probably play a role in cellular replicative senescence and oxidative-stress inducing premature senescence. Besides, histone modification could regulate P66^SHC gene expression.

关 键 词： 过氧化氢 复制性衰老 氧化应激 组蛋白修饰

领　　域： [生物学] [生物学]