Expression of Urocortin in the Extravillous Human Trophoblast at the Implantation Site

Bamberger, C.M.; Minas, V.; Bamberger, A.-M.; Charalampopoulos, I.; Fragouli, Y.; Schulte, H.M.; Makrigiannakis, A.

doi:10.1016/j.placenta.2006.03.013

« Previous Next »Placenta
Volume 28, Issue 2 , Pages 127-132, February 2007

Expression of Urocortin in the Extravillous Human Trophoblast at the Implantation Site

C.M. Bamberger
- Center of Internal Medicine, Department of Gynecopathology, University Hospital Eppendorf, Hamburg 22767, Germany
- The first two authors contributed equally to this project.
V. Minas
- Laboratory of Human Reproduction, Department of Obstetrics and Gynecology, School of Medicine, University of Crete, Heraklion 71003, Greece
- The first two authors contributed equally to this project.
A.-M. Bamberger
- Institute of Pathology, Department of Gynecopathology, University Hospital Eppendorf, Hamburg 22767, Germany
I. Charalampopoulos
- Laboratory of Human Reproduction, Department of Obstetrics and Gynecology, School of Medicine, University of Crete, Heraklion 71003, Greece
Y. Fragouli
- Laboratory of Human Reproduction, Department of Obstetrics and Gynecology, School of Medicine, University of Crete, Heraklion 71003, Greece
H.M. Schulte
- Endokrinologikum, Hamburg 22767, Germany
A. Makrigiannakis
- Laboratory of Human Reproduction, Department of Obstetrics and Gynecology, School of Medicine, University of Crete, Heraklion 71003, Greece
- Corresponding author. Tel.: +30 2810 392333; fax: +30 2810 394530.

Accepted 22 March 2006. published online 24 May 2006.

Abstract

Urocortin (UCN) is a 40 amino acid peptide which is closely related to corticotropin-releasing hormone and binds with high affinity to both CRH type 1 and type 2 receptors. UCN is expressed in human reproductive tissues including endometrium, ovary, and placenta. This study was designed to investigate the cellular localization of UCN at the implantation site of the human blastocyst, as well as the regulation of the UCN promoter by two major intracellular signaling pathways, the cAMP/PKA and diacylglycerol/PKC pathways, in cells of placental origin. For this reason, immunohistochemistry was performed on tissue sections from paraffin-embedded human first trimester placentas and freshly isolated human invasive extravillous trophoblast cells (EVT) were analyzed for UCN expression using RT-PCR and immunofluorescence. Finally, UCN promoter activity was analyzed in the JEG3 human choriocarcinoma cell line. Immunohistochemistry revealed expression of UCN in the cytotrophoblast, the EVT and decidual cells. Both UCN mRNA and peptide were detectable in freshly isolated EVT. Finally, a human UCN promoter luciferase reporter construct transfected into JEG3 cells was significantly inducible by phorbol ester plus ionomycin, but not by phorbol ester alone or by forskolin. Collectively, the present study reports the expression of UCN in EVT and the activation of the UCN gene promoter by the diacylglycerol/PKC pathway. The functional significance of urocortin for the physiology of EVT requires further investigation.

Keywords: Implantation site, Extravillous trophoblast, Urocortin