Geburtshilfe Frauenheilkd 2011; 71 - G_7
DOI: 10.1055/s-0031-1286413

Endothelin-1 stimulates proliferation of first trimester trophoblasts via the A- and B-type receptor and invasion via the B-type receptor

M Cervar-Zivkovic 1, M Dieber-Rotheneder 1, S Barth 1, 4, T Hahn 1, 3, G Kohnen 2, B Huppertz 3, U Lang 1, G Desoye 1
  • 1Department of Obstetrics & Gynaecology, Medical University of Graz, Austria
  • 2Department of Pathology, Western Infirmary, University of Glasgow, UK
  • 3Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Austria
  • 4Institute of Biochemistry and Molecular Biology, Medical University of Graz, Austria

Endothelin-1 (ET-1) stimulates proliferation and invasion of first trimester human trophoblast cells.

Objective:

To test the hypothesis that ET-1 effects are mediated by different receptor subtypes (ETRs: ETR-A, ETR-B).

Methods:

The location of ETRs in trophoblast cell columns (weeks 6–12) was investigated by immunohistochemistry and autoradiography. Trophoblasts were isolated from first trimester human placentas and proliferative and invasive subpopulations separated using an integrin α6 antibody. Cells were incubated for 24h with 10µM ET-1 and different ETR-antagonists: PD142893 (unselective), BQ-610 (ETR-A) and RES-701–1 (ETR-B). After ETR downregulation by antisense oligonucleotides, proliferation (thymidine incorporation, protein synthesis) and invasion (Matrigel invasion) were measured. ETR expression in isolated cells was analyzed by Western blotting and sqRT-PCR.

Results:

Both ETRs are expressed in both subpopulations in the cell column with predominance of ETR-A in the proximal part and proliferative subpopulation, whereas ETR-B is present at similar levels in both subpopulations. These results were confirmed at the mRNA level. ET-1 increased proliferation (max 267% of control) and invasion (max 288% of control) of first trimester trophoblasts. The mitogenic ET-1 effect was inhibited (p<0.05) by 40–80% with each receptor antagonist, and by 44% and 40%, respectively, by ETR-A and ETR-B antisense-oligonucleotides. The invasion promoting effect was almost completely blocked in the presence of the ETR-B antagonists.

Conclusion:

The effect of ET-1 on cell proliferation in first trimester trophoblasts is mediated by both ETRs, while its effect on invasion is mediated predominantly by ETR-B. These effects are in line with receptor subtype location.