Pan Bo
Children’s Hospital of Chongqing Medical University, China
Title: Alcohol exposure induced Histone3 Lysine9 hyperacetylation and over-expression of heart development-related genes both in vitro and in vivo
Biography
Biography: Pan Bo
Abstract
Background: Alcohol abuse during gestation may cause congenital heart diseases (CHD). The underlying mechanisms of alcohol induced cardiac deformities are still not clear. Recent studies suggest that histone modification may play a crucial role in this pathological process. The aim of this study is to investigate the effect and the mechanisms of alcohol exposure on histone acetylation modification and the expression of heart development-related genes during heart development.
Material & Methods: Cardiac progenitor cells and KM mice were used in in vitro and in vivo studies respectively. Pregnant mice were gavaged with ethanol or saline every day in the morning from E7.5 to E15.5. Western blotting and real-time PCR were employed to determine H3AcK9 acetylation and gene expression. HATs and HDACs activities were detected by colorimetric assay and fluorometric assay. Chromatin immunoprecipation (ChIP) assay was used for the detection of H3AcK9 acetylation level in the promoter region of heart development-related transcription factors.
Results: Low level of ethanol or its metabolites had little effect on H3AcK9 acetylaiton or the expression of heart development-related genes. However, high doses of ethanol and acetate significantly increased H3AcK9 level and augmented the expression of GATA4 and Mef2c (p<0.05). In whole animal experiments, the level of H3AcK9 acetylation reached peak at E17.5 and decreased sharply to a low level at birth and maintained at low level afterward. Alcohol exposure increased H3AcK9 acetylation at E11.5, E14.5, E17.5 and E18.5 respectively (p<0.05), and enhanced the expression of Gata4 in the embryonic hearts at E14.5 and E17.5, Mef2c at E14.5 and Nkx2.5 at E14.5 and E17.5, (p<0.05) but not for Tbx5 (p>0.05). On embryonic day 17.5, HATs activities of embryonic hearts increased significantly, however alcohol exposure did not alter HDACs activities. H3AcK9 level in the promoter of Gata4 and Nkx2.5 were increased significantly (p<0.05).
Conclusion: Alcohol exposure both in vitro and in utero may induce an increase of HATs activities, which results in H3K9 hyperacetylation and an enhanced expression of heart development-related genes.