Islet-1诱导成纤维细胞系C3H10T1/2向心肌细胞分化过程中组蛋白乙酰化与DNA甲基化在GATA4启动子区的关系

Relationship between histone acetylation and DNA methylation in GATA4 promoter region during Islet-1 induced differentiation of C3H10T1/2 cell line specifically into cardiomyocytes

目的研究在Islet-1诱导间充质干细胞C3H10T1/2向心肌细胞特异分化过程中的心肌早期发育相关基因GATA4启动子区域组蛋白乙酰化与DNA甲基化的相互作用关系。方法构建过表达Islet-1细胞模型,在GATA4基因表达过程中,用染色质免疫共沉淀技术(CHIP)检测其启动子区组蛋白H3K9乙酰化的时序性变化;甲基化特异性PCR技术(MSP)检测其启动子区Cp G岛甲基化的时序性变化,明确两者之间相互作用的关系。结果随着Islet-1诱导C3H10T1/2向心肌细胞特异分化的时间延长,GATA4基因的表达增高(P<0.05),其启动子区第2个Cp G位点组蛋白H3K9乙酰化的水平升高(P<0.05),DNA甲基化水平降低(P<0.05)。结论 Islet-1诱导C3H10T1/2细胞向心肌细胞特异分化过程中,组蛋白乙酰化和DNA甲基化在调控心肌特异早期转录因子GATA4表达过程中存在相互拮抗作用,从而促其表达呈时序性变化。

Objective To research the interaction between early myocardial developmental gene GATA4 histone acetylation and its DNA methylation of promoter during Islet-1 inducing the mesenchymal stem cells of C3H10T1/2 cells to differentiate specifically into cardiomyocytes. Methods Constructing the model of Islet-1 over-expression cells,in the process of GATA4 gene expression by using chromatin immunoprecipitation （CHIP）to detecte histone H3K9 acetylation sequential changes of its promoter region and using the methylation-specific PCR（ MSP）to detect methylation sequential changes in CpG island of its promoter region, to elucidate the interaction between the both. Results With prolongation of time during Islet-1 inducing C3H10T1/2 to differentiate specifically into cardiomyo- cytes, the expression of the GATA4 gene increased （ P 〈 0. 05 ）, the level of histone H3 K9 acetylation raised （ P 〈0. 05）,while the DNA methylation level decreased in second CpG site of its promoter （P 〈 0. 05 ）. Conclusions When Islet-1 promotes cells into cardiac-specific differentiation process, histone acetylation and DNA methylation exist mutual antagonism in regulation of the process of early, myocardial specific transcription factor GATA4 expres- sion, which promoted its sequential expression.