姜黄素对小鼠心脏发育相关基因表达的影响及其表观遗传调控机制

摘要

目的 阐明姜黄素对心脏发育相关基因GATA4,MEF2C和Nkx2.5表达的影响,探讨其表观调控机制.方法 姜黄素处理新生鼠心肌细胞后,分别用ELISA,Western blot,real time RT-PCR和染色质免疫沉淀(ChIP)检测组蛋白乙酰化酶活性,组蛋白H3乙酰化修饰状态,GATA4,MEF2C和Nkx2.5的表达和启动子区域组蛋白乙酰化水平.结果 30μmol/L姜黄素作用24 h能有效降低心肌细胞中组蛋白乙酰化酶活性和组蛋白H3的乙酰化修饰状态,GATA4,MEF2C和Nkx2.5的表达水平明显降低(分别为0.34±0.017,0.26±0.04和1.05±0.12)(P<0.05),启动子区域组蛋白乙酰化修饰水平明显降低(分别为1.75±0.67,2.13±0.99和1.29±0.40)(P<0.05).结论 启动子区域组蛋白乙酰化修饰状态降低导致染色质构型紧密,可能为姜黄素抑制GATA4,MEF2C和Nkx2.5表达的调控机制之一.%Objective To investigate the effects of curcumin on heart development-related genes GATA4, MEF2C and Nkx2.5, and to explore the epigenetic regulation mechanism.Methods Cardiocytes from neonatal mouse were treated with curcumin with different concentrations and different time.ELISA was used to detect the histone acetylase(HATs) activity of cardiocytes, Western blot was used to detect the acetylation of histone H3 and real time RT-PCT to measure the expression of heart development-related genes GATA4, MEF2C and Nkx2.5.Results Thirty μ mol/L of curcumin inhibited the HAT activity and the acetylation of histone H3 at 24 hours.Accordingly the expression of GATA4, MEF2C and Nkx2.5 were repressed significantly (0.34 ±0.017, 0.26 ±0.04 and 1.05 ±0.12 respectively, P ＜0.05).The result of ChIP-PCR showed that the the acetylation of histone which bound with promoter regions of these genes were reduced ( 1.75 ± 0.67, 2.13 ± 0.99 and 1.29 ± 0.40 respectively,P ＜0.05 ).Conclusion Curcumin may inhibit the HAT activity and may repress the expression of heart development-related genes GATA4, MEF2C and Nkx2.5 effectively.The loose structure of chromatin induced by hypoacetylation of histone bound with promoter regions might be one mechanism of this effect.