Objective    To investigate the cytotoxicity and H3K9 epimutation induced by ethanol and its metabolites to cardiac progenitor cells.     Methods    Cardiac progenitor cells (1×10

5

) were treated with ethanol at 200

100 or 50 mmol/L respectively

and acetaldehyde or acetic acid at 16

12

8 or 4 mmol/L respectively for 24 h. MTT assay was used to select the intervention concentrations

We

stern blot analysis to detect the acetylation of histone H3K9

and realtime PCR to measure the expressions of heart development-related genes GATA4

Mef2c and Tbx5.     Results    MTT assay showed that low concentration groups [50 mmol/L ethanol (0.368±0.028)

4 mmol/L acetaldehyde (0.336±0.040) and 4 mmol/L acetic acid (0.359±0.014)

]

had no effect on the proliferation of cells compared with control (0.358±0.066

P0.05)

but high concentration groups [200 mmol/L ethanol (0.245±0.042)

12 mmol/L acetaldehyde (0.220±0.017) and 16 mmol/L acetic acid (0.243±0.024)

]

were greatly affected in the cell proliferation by 30% (P0.05). Low concentration groups of ethanol and acetic acid increased the acetylation of H3K9 by 2.4- and 2.2-fold respectively (P0.05)

but had no effect on the expressions of heart development-related genes (P0.05). High concentration groups of ethanol and acetic acid showed a 5.3- and 5.6-fold elevation in the acetylation of H3K9

and the expression of GATA4 was increased to 1.767±0.173 and 1.518±0.133 respectively

that of Mef2c increased to 3.301±0.465 and 1.875±0.587 as compared with control or the corresponding low concentration groups (P0.05). Both 4 or 12 mmol/L acetaldehyde had no obvious effect on the acetylation of H3K9 and the expressions of heart development-related genes (P0.05).     Conclusion    High concentrations of ethanol and its metabolites have a cytotoxicity effect on cardiac progenitor cells. Ethanol and acetic acid induce H3K9 epimutation

which may be one of the pathogenesis of congenital heart diseases caused by alcohol.