Downregulation of GATA4 and GATA6 in the heart of rats with nitrofen-induced diaphragmatic hernia.
OBJECTIVE
The high incidence of cardiac malformations in humans and animal models with congenital diaphragmatic hernia (CDH) is well known. The precise molecular mechanisms underlying cardiac maldevelopment in CDH are still unclear. It has been reported that GATA4 and GATA6, members of the GATA transcription factor family, act cooperatively to regulate cardiovascular development, and the levels of cardiac GATA4 and GATA6 are important regulators of cardiomyocyte proliferation, cardiac morphogenesis, and embryo survival. In addition, the GATA4/GATA6 double heterozygous mutant embryo model displayed a spectrum of cardiovascular malformations similar to those seen in human CDH and nitrofen-induced animal models, including ventricular and aortopulmonary septal defects and thin ventricular myocardium. To test the hypothesis that expression of GATA4 and GATA6 is reduced in early stages of gestation in a CDH hypoplastic heart, we investigated the expression of GATA4 and GATA6 in the hearts of nitrofen-treated rats in early gestation. Wnt2, bone morphogenetic protein 4 (BMP4), and myocyte enhancer factor 2C (MEF2C) were also investigated as GATA4/6 target genes involved in cardiogenesis.


METHODS
Fetal rat hearts of normal (n = 7) and nitrofen-treated (n = 7) dams were harvested on embryonic day 13. The expression of GATA4, GATA6, Wnt2, BMP4, and MEF2C was analyzed in each heart by real-time reverse transcription-polymerase reaction.


RESULTS
The gene expression of GATA4, GATA6, Wnt2, BMP4, and MEF2C on embryonic day 13 were significantly reduced (P < .05) in the hearts of nitrofen-treated animals compared with normal hearts of equivalent age.


CONCLUSIONS
Decreased expression of GATA4 and GATA6 and their target genes in the developing fetal heart may perturb the delicate regulation of cardiovascular development, resulting in cardiovascular malformations in the nitrofen rat model.
Takayasu
Hajime
H
Children's Research Centre, Our Lady's Hospital for Sick Children, University College Dublin, 12 Dublin, Ireland.
Sato
Hideaki
H
Sugimoto
Kaoru
K
Puri
Prem
P
D000818:Animals; D000831:Animals, Newborn; D004195:Disease Models, Animal; D015536:Down-Regulation; D005260:Female; D050991:GATA4 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D050993:GATA6 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006330:Heart Defects, Congenital / Q000235:genetics* / Q000503:physiopathology; D006548:Hernia, Diaphragmatic / Q000235:genetics*; D065630:Hernias, Diaphragmatic, Congenital; D010647:Phenyl Ethers; D011247:Pregnancy; D011270:Pregnancy, Animal; D011336:Probability; D012333:RNA, Messenger / Q000032:analysis; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D050991:GATA4 Transcription Factor; D050993:GATA6 Transcription Factor; D010647:Phenyl Ethers; D012333:RNA, Messenger; C007350:nitrofen