| Objective: GATA4 as the core of transcription factor in heart development, it began to expression in the early heart development, and increased expression to adult in myocardium. Our previous study found that GATA4 expression was regulated by histone acetylation modification. CBP/P300 is one of histone acetylase. In this study, we explore the temporal expression of GATA4 in the process of mouse embryonic heart development and elucidate the mechanism of histone modification.Methods: Fetal mouse hearts from gestational age E11.5 to postnatal 0.5 day and cardiac progenitor cells treated with CBP30 was used to measure the expression of GATA4 by TR-PCR and the binding level of histone marker H3K9 acetylation, dimethylation, trimethylation and CBP/P300 in GATA4 promoter region by ChIP assays.Results:1. The mRNA expression of GATA4 was tested from E11.5 to postnatal and it increased to the peak at E14.5(p<0.05), before remaining stable between E14.5 and E17.5(p>0.05). ChIP assay demonstrated that H3K9 ac binding to GATA4 promoter region witnessed a highest level at E17.5 compared to that at E11.5 and E14.5(p<0.05)and the figure at E14.5 was larger than that at E11.5(p<0.05). Interestingly, the binding level of H3K9me2 to GATA4 showed a highest figure at E14.5 among all the groups(p<0.05). The levels of H3K9me3 and CBP/P300 binding to the same gene was very similar with the value of H3K9me2.2. Compared with control group, CBP30 at different concentrations(0.5uMã€1uMã€2uMã€4uM)had obvious abilities to downregulate GATA4 expressions in cardiac progenitor cells respectively, especially at the concentration of 4uM(p<0.05). After challenged with CBP30(2uM) at different times( 6hã€12hã€24hã€48h), there was a sharp decease in expression of GATA4 at 6h(p<0.05).In CBP30 group, all the tested markers above decreased dramatically,compared to control group.Conclusion: The CBP/P300-mediated acetylation of H3K9 could be involved in the regulation of GATA4 expression over the development of mice heart. |
