Decreased placental GCM1 (glial cells missing) gene expression in pre-eclampsia

Pre-eclampsia is a multisystem disorder of pregnancy associated with elevated blood pressure, proteinuria, and complex biochemical disturbances. The mammalian homologue of the glial cells missing (GCM) gene, GCM1, is selectively expressed in the placenta. GCM1 expression has been shown to affect placental branching and vasculogenesis, abnormalities of which may result in the development of pre-eclampsia. In this study immunohistochemistry, Western blot, and quantitative real-time PCR were used to investigate GCM1 expression at different gestational ages and in pre-eclampsia. Of 36 placentae without pre-eclampsia (ranged from 5-40 weeks of gestation), the level of GCM1 expression was relatively constant before late third trimester. The immunoreactivity of GCM1 protein and the level of GCM1 mRNA were not significantly different during normal pregnancy until 37 weeks of gestation, when the level of GCM1 expression was reduced significantly. Furthermore, significant reductions in GCM1 protein and mRNA were observed in pre-eclamptic placentae compared with gestational age-matched controls. Our results suggest that GCM1 is a distinct transcription factor involved in placental disease and altered expression of the GCM1 gene may contribute to the etiology of pre-eclampsia.