title: Expression of EphA8-Fc in transgenic mouse embryos induces apoptosis of neural epithelial cells during brain development.
abstract: EphAs and ephrin-As are expressed in multiple regions of the developing brain and have been implicated in regulating brain size. Here, we report the identification of a novel mechanism in which reverse signaling through ephrin-As controls neural epithelial cell number in the developing brain. Ectopic expression of EphA8-Fc in transgenic embryos induced apoptosis of neural epithelial cells, which was accompanied by a dramatic decrease in brain size. The number of ephrin-A5-expressing cells was significantly reduced in the brain region where EphA8-Fc was ectopically expressed. Furthermore, in vitro culture of the dissociated neuroepithelial cells revealed that EphA8-Fc enhanced apoptotic cell death of the ephrinA5-expressing cells in a caspase-dependent manner. Thus, our results suggest that reverse signaling through ephrin-As is biochemically linked with caspase-dependent proapoptotic signaling during early brain development.
authors.affiliation: Department of Biological Science, Sookmyung Women's University, Yongsan-gu, Seoul 140-742, Korea.
authors.forename: Yujin
authors.initials: Y
authors.lastname: Kim
authors.forename: Eunjeong
authors.initials: E
authors.lastname: Park
authors.forename: Hyuna
authors.initials: H
authors.lastname: Noh
authors.forename: Soochul
authors.initials: S
authors.lastname: Park
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D022202:Chromosomes, Artificial, Bacterial; D036386:Ephrin-A5 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D046569:Neuroepithelial Cells / Q000378:metabolism*; D036143:Receptor, EphA8 / Q000378:metabolism*
chemical_list: D036386:Ephrin-A5; D036143:Receptor, EphA8; D053148:Caspase 3
keywords: EphA; apoptosis; early brain development; ephrin-A