Mouse ATF-2 Null Mutants Display Features of a Severe Type of Meconium Aspiration Syndrome

• Published in: The Journal of biological chemistry Vol. 274; no. 25; pp. 17813 - 17819
• Main Authors: Maekawa, T, Bernier, F, Sato, M, Nomura, S, Singh, M, Inoue, Y, Tokunaga, T, Imai, H, Yokoyama, M, Reimold, A, Glimcher, L H, Ishii, S
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 18.06.1999
• Subjects: Activating Transcription Factor 2; Animals; Cyclic AMP Response Element-Binding Protein - genetics; Cyclic AMP Response Element-Binding Protein - metabolism; Disease Models, Animal; Gene Expression Regulation; Gene Targeting; Humans; Hypoxia - genetics; In Situ Hybridization; Infant, Newborn; Lung - pathology; Meconium Aspiration Syndrome - genetics; Meconium Aspiration Syndrome - pathology; Mice; Mice, Knockout; Mutation - genetics; Placenta - metabolism; Promoter Regions, Genetic; Receptors, Platelet-Derived Growth Factor - genetics; Respiratory Distress Syndrome, Newborn - genetics; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.274.25.17813

Mouse null mutants of transcription factor ATF-2 were generated by the gene targeting method. They died shortly after birth and displayed symptoms of severe respiratory distress with lungs filled with meconium. These features are similar to those of a severe type of human meconium aspiration syndrome. The increased expression of the hypoxia inducible genes suggests that hypoxia occurs in the mutant embryos and that it may lead to strong gasping respiration with consequent aspiration of the amniotic fluid containing meconium. A reduced number of cytotrophoblast cells in the mutant placenta was found and may be responsible for an insufficient supply of oxygen prior to birth. Using the cDNA subtraction and microarray-based expression monitoring method, the expression level of the platelet-derived growth factor receptor α gene, which plays an important role in the proliferation of trophoblasts, was found to be low in the cytotrophoblasts of the mutant placenta. In addition, ATF-2 can trans -activate the PDGF receptor α gene promoter in the co-transfection assay. These results indicate the important role of ATF-2 in the formation of the placenta and the relationship between placental anomalies and neonatal respiratory distress. The ATF-2 null mutants should enhance our understanding of the mechanism of severe neonatal respiratory distress.