Alcohol Consumption During Gestation Causes Histone3Lysine9Hyperacetylation And An Alternation Of Expression Of Heart Development-related Genes In Mice

ObjectiveAlcohol abuse during gestation may cause congenetial heart diseases(CHD). The underlying mechanisms of alcohol induced cardiac deformitiesare still not clear. In our previous studies, we found that the imbalance ofhistone acetylation could disturb the expression of heartdevelopment-related genes, blocking the differentiation process of thedifferentiation of mesenchymal stem cells into cardiomyocytes. We alsoobserved that ethanol and its metabolites could enhance the level ofacetylation of H3lysine9and lead to an alternation of the expression of theheart development-related genes in vitro. Consequently, in this study, weinvestigated the effect of alcohol consumption during gestation on theimbalance of H3AcK9acetylation and the alternation of expression of heartdevelopment-related genes during cardiogenesis.MethodsThe pregnant mice were exposed to a single dose of alcohol (10ul/g/d, 56%alcohol) by gavage between E7.5to E15.5. Western-Blot andquantitative real-time PCR were used for detecting the level of H3AcK9acetylation and genes expression.Results1.Our data indicate the blood concentration of alcohol reached348.15±77.49mg/100ml in the mice exposed to a dose of alcohol of10ul/g/d.This value is higher than that of from mice exposed to a lowerdose(2.5ul/g/d or5ul/g/d). However if the reaches15ul/g/d, it could cause ahigh abortion rate in the pregnant mice(4/5). Therefore we use a dose of10ul/g/d as in the following studies.2.H&E staining of cardiac tissue showed an abnormality ofcardiomyocytes and a thinner ventricular septum existing int the heartsfrom alcohol-treated mice.3.The level of H3AcK9acetylation reached peak at E17.5anddecreased sharply to a significantly low level at birth and maintained in asubside state afterward. And total histone3acetylation level decreaseabruptly from E17.5to newborn also. Alcohol exposure increased H3AcK9acetylation at E11.5, E14.5, E17.5and E18.5respectively (p<0.05),4.Q-PCR showed an enhanced expression of Gata4at E14.5and E17.5,Mef2c at E14.5and Nkx2.5at E14.5and E17.5(p<0.05) in mice withalcohol exposure. ConclusionThese data showed a time-course of of H3AcK9acetylation changeduring heart development and demonstrated that alcohol exposure inutero might induce a H3AcK9hyperacetylation and increase theexpression of heart development-related genes. These findings indicate anew mechanism that stands behind alcohol induced congenital heartdiseases.