Published in:
01-02-2004 | Original Article
Expression pattern of the CCAAT/enhancer-binding proteins C/EBP-α, C/EBP-β and C/EBP-δ in the human placenta
Authors:
Ana-Maria Bamberger, Antonis Makrigiannakis, Martina Schröder, Christoph M. Bamberger, Constantine Relakis, Birgit Gellersen, Karin Milde-Langosch, Thomas Löning
Published in:
Virchows Archiv
|
Issue 2/2004
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Abstract
The human trophoblast has the capacity to invade maternal tissue in a controlled fashion and to produce a wide range of hormones. The transcription factors belonging to the CCAAT/enhancer-binding protein (C/EBP) family are regulators of intracellular processes and mediators of hormone action. C/EBP binding sites have been described in the promoters of several placenta-expressed target genes. In the present study, we used immunohistochemistry and Western-blot analysis to investigate the expression pattern of the three most important members of this family, C/EBP-α, -β, and -δ, in the normal human placenta as well as in isolated trophoblast cell populations. We found C/EBP-α and C/EBP-β expression in the villous syncytiotrophophoblast (ST) and the extravillous (intermediate) trophoblast (EVT), but it was absent from the villous cytotrophoblast (CT). Interestingly, expression of C/EBP-β continued to be very strong up to the third trimester of pregnancy, especially in the ST. C/EBP-δ showed overall lower expression levels, stronger only in the EVT, while CT/ST showed very low/negative expression. These data show for the first time the expression pattern and tissue localization of C/EBP factors in the human placenta, indicating that these factors (especially C/EBP-β) may play important roles in the regulation of placenta-specific genes and processes.