title: Alcohol consumption during gestation causes histone3 lysine9 hyperacetylation and an alternation of expression of heart development-related genes in mice.
abstract: BACKGROUND
  Alcohol abuse during gestation may cause congenital heart diseases (CHDs). 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. Moreover, our previous studies reported that ethanol could induce histone3 lysine9 (H3K9) hyperacetylation and overexpression of heart development-related genes in vitro. The aim of this study was to investigate the effect of alcohol consumption during gestation on the imbalance of H3K9 acetylation and the alternation of the expression of heart development-related genes during cardiogenesis.
  
  
  METHODS
  Pregnant mice were exposed to a single dose of alcohol (10 μl/g/d, 56% alcohol) by gavage every day in the morning from embryo day 7.5 (E7.5) to E15.5. Hematoxylin and eosin (H&E) staining was applied for observing the structure of the embryonic hearts. Western blotting and quantitative real-time polymerase chain reaction were used for detecting the level of H3K9 acetylation and gene expression. Histone acetyltransferase (HAT) and histone deacetylase (HDAC) activities were detected by colorimetric assay and fluorometric assay.
  
  
  RESULTS
  H&E staining of cardiac tissue showed abnormalities of embryonic hearts at E17.5. The level of H3K9 acetylation reached peak at E17.5 and decreased sharply to a low level at birth and maintained at low level afterward. Alcohol exposure increased H3K9 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, HAT activities of embryonic hearts increased significantly, however alcohol exposure did not alter HDAC activities.
  
  
  CONCLUSIONS
  These data indicate a time course of H3K9 acetylation change during heart development and demonstrate that alcohol exposure in utero may induce an increase of HAT activities, which results in H3K9 hyperacetylation and an increase of the expression of heart development-related genes. These findings reveal a novel epigenetic mechanism that connects the alcohol consumption during the pregnancy and the development of CHD in the fetus.
authors.affiliation: Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education, Chongqing, China; Key Laboratory of Pediatrics in Chongqing, Chongqing, China; Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China; Heart Centre, The Children's Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Pan
authors.forename: Jing
authors.initials: J
authors.lastname: Zhu
authors.forename: Tiewei
authors.initials: T
authors.lastname: Lv
authors.forename: Huichao
authors.initials: H
authors.lastname: Sun
authors.forename: Xupei
authors.initials: X
authors.lastname: Huang
authors.forename: Jie
authors.initials: J
authors.lastname: Tian
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000428:Alcohol Drinking / Q000009:adverse effects / Q000378:metabolism*; D000818:Animals; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D006321:Heart / Q000187:drug effects* / Q000196:embryology*; D006657:Histones / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism*; D051379:Mice; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000378:metabolism
chemical_list: D006657:Histones; D008239:Lysine
keywords: Alcohol; Alcohol-Induced Congenital Heart Diseases; Cardiogenesis; Heart Development-Related Genes; Histone 3 Lysine9 Acetylation