细胞复制衰老过程中IGF2R基因表达及H3组蛋白修饰的变化  

The Profile of IGF2R Gene Expression and H3 Histone Modifications in Replicative Cell Senescence

作　　者：徐薇[1,2] 庄志雄[2] 杨建平[2] 杨琳清[2] 许玉玲[2] 张文娟[2] 曾怡[1] 

机构地区：[1]四川省疾病预防控制中心,成都610041 [2]深圳市疾病预防控制中心,深圳518055

出　　处：《四川大学学报（医学版）》2014年第1期6-9,共4页Journal of Sichuan University(Medical Sciences)

摘　　要：目的研究细胞复制性衰老过程中胰岛素样生长因子2受体基因（IGF2R）的表达与H3组蛋白修饰谱的变化。方法培养人胚肺成纤维细胞（HPF），以细胞群倍增数（PDL）为23（PDL23）为年轻组细胞，PDL＝50（PDL50）为复制衰老细胞，观察细胞复制衰老过程中生物学性状改变；采用实时定量PCR法观察细胞PDL30、PDL40、PDL50 IGF2R基因的表达，并采用染色质免疫共沉淀-实时定量PCR法（chromatinimmunoprecipitation-real time quantitative PCR methods，CHIP-PCR）检测IGF2R基因转录起始区组蛋白修饰（H3-Ac、H3K9-tri—Me、H3K9-Ac和H3K4-tri—Me）的状况。结果与年轻细胞相比，衰老细胞体积变大，增殖能力减弱，细胞周期停滞，衰老特异性肛半乳糖苷酶着色阳性，IGF2RmRNA表达增加（P〈0．05），IGF2RmRNA表达与细胞PDL呈正相关（r=0．871）。相对年轻细胞而言，老年细胞的IGF2R基因在转录起始点上游0．6kb处和转录起始点下游1．2kb处以H3-Ac、H3K9-Ac和H3K4-tri—Me组蛋白修饰为主，而在转录起始点下游1．6～4．0kb处H3K9-Ac修饰降低，H3K9-tri—Me组蛋白修饰升高，但H3K4-tri—Me组蛋白修饰占主要地位。结论IGF2R与细胞衰老程度相关，其基因表达受H3组蛋白修饰调控，表观遗传学参与细胞衰老进程。Objective To study the profile of IGF2R expression and histone modifications in replicative cell senescence. Methods The changes of biological characteristics of young human pulmonary fibroblast （ HPF） cells Cat population doubling level （PDL） 23〕and aging HPF cells （at PDL50） were observed and real-time quantitative PCR was utilized to investigate human IGF2R gene expressions profile during the procevss of cellular aging （at different PDL）. Then chromatinimmunoprecipitation-real time quantitative PCR （CHIP-QPCR） methods were conducted to analyze histone modifications of the regions around the transcriptional start site of IGF2R （H3-Ac, H3K9-tri-Me？ H3K9-Ac and H3K4-tri-Me）. Results In contrast to young cells, the aging cells were bigger and less proliferative, their cell cycles arrest,and aging specific p-galactosidase staining was positive. IGF2R gene expression was in positive correlation with PDL. H3-Ac,H3K9-Ac and H3K4-tri-Me were dominant in the upstream region （ - 0. 6 kb） to the downstream region （ ＋ 1.2 kb） of transcriptional start site （TSS）. While in the downstream of TSS from ＋1. 6 kb to ＋4. 0 kb,H3K9-Ac was declined and H3K9-tri-Me was elevated in turn, but H3K4-tri-Me still prevailed in these areas. Conclusion IGF2R is related to cell replicative senescence and its gene expression is regulated by histone modification of H3. Therefore,epigenetics may play a role in cell senescence.

关 键 词：复制性衰老 胰岛素样生长因子2受体 基因表达 组蛋白修饰 

分 类 号：R346[医药卫生—基础医学]