丁酸钠对K562细胞γ-珠蛋白基因启动子组蛋白磷酸化的影响

Effect of Sodium Butyrate on Phosphorylation of Histone at γ-Globin Gene Promoter Regions in K562 Cells

目的探讨丁酸钠(NaB)对K562细胞Gγ-珠蛋白基因和Aγ-珠蛋白基因启动子区域组蛋白H3磷酸化/乙酰化(ph/acH3)的影响。方法将K562细胞按不同处理方法分为2组,即0.5 mmol.L-1NaB处理48 h的K562细胞组[K562(NaB)组]和K562亲本细胞组(K562组)。采用半定量RT-PCR测定Gγ-珠蛋白和Aγ-珠蛋白mRNA水平,采用基于Real time PCR分析的染色质免疫共沉淀(ChIP)方法分析不同处理细胞Gγ-珠蛋白和Aγ-珠蛋白基因启动子区域ph/acH3水平。结果与K562组细胞比较,K562(NaB)组细胞Gγ-珠蛋白mRNA、Aγ-珠蛋白mRNA的相对水平分别升高1.4倍(t=-149.022,P=0.000)和1.2倍(t=-13.363,P=0.000)。与K562组比较,K562(NaB)组细胞Gγ-珠蛋白和Aγ-珠蛋白基因启动子区ph/acH3水平分别升高了2.9倍(t=-12.833,P=0.006)和3.2倍(t=-10.484,P=0.000)。K562(NaB)组细胞Gγ-珠蛋白和Aγ-珠蛋白基因启动子片段的%In-put值分别比Necdin基因升高10.0倍(P=0.000)、9.5倍(P=0.000);K562组细胞的Gγ-珠蛋白和Aγ-珠蛋白基因启动子片段的%Input值分别比Necdin基因升高3.2倍(P=0.000)、2.7倍(P=0.000)。结论 NaB可促使γ-珠蛋白基因启动子区域组蛋白H3磷酸化及乙酰化,这一作用途径可能是NaB诱导K562细胞γ-珠蛋白基因表达的机制之一。

Objective To explore the effect of sodium butyrate（NaB） on phosphorylation/ acetylation of histone H3（ph/acH3） at Gγ-globin gene and Aγ-globin gene promoter regions in K562 cells.Methods K562 cells were devided into 2 groups：K562 cells were grown in the presence or absence of 0.5 mmol·L-1NaB for 48 h [K562（NaB） group] and untreated K562 cells group（K562 group）.Semi-quantitative RT-PCR was employed to measure the levels of Gγ-globin mRNA and Aγ-globin mRNA.The real time PCR-based chromatin immunoprecipitation（ChIP） was used to detect the levels of ph/acH3 at Gγ-globin gene and Aγ-globin gene promoter regions.Results Compared with the K562 group,there was a 1.4-fold（t=-149.022,P=0.000） and 1.2-fold（t=-13.363,P=0.000） increase in Gγ-globin mRNA and Aγ-globin mRNA,respectively,in K562（NaB） group.The level of ph/acH3 at Gγ-globin gene and Aγ-globin gene promoter region increased by 2.9-fold（t=-12.833,P=0.006） and 3.2-fold（t=-10.484,P=0.000）,respectively,in K562（NaB） group,compared with the K562 group.The %Input value of Gγ-globin and Aγ-globin promoter fragment was 10.0-fold（P=0.000） and 9.5-fold（P=0.000） higher than that value of Necdin gene promoter fragment in the K562（NaB） group,while the %Input value of Gγ-globin and Aγ-globin promoter fragment was 3.2-fold（P=0.000） and 2.7-fold（P=0.000） higher than that value of necdin gene promoter fragment in K562 group.Conclusions NaB improves the phosphorylation and acetylation of H3 at γ-globin gene promoter regions,and this may be one of the mechanisms of expression of γ-globin genes induced by NaB.