Inhibin-betaC subunit expression in normal and pathological human placental tissues

Abstract

Inhibins and activins are important regulators of the female reproductive system. Recently, a novel inhibin betaC subunit has been identified. However, only limited data on the expression of this novel inhibin-betaC subunit in normal and pathological human placentas exist. Tissue specimens of normal, preeclamptic, hemolysis, elevated liver enzymes, low platelets (HELLP), and intrauterine growth restriction (IUGR) pregnancies (n = 24) were obtained at the conclusion of a cesarean section. Normal and pathological placental tissues were analyzed by an immunohistochemical staining reaction with a specific antibody against this novel inhibin-betaC subunit. Overall, expression of the inhibin-betaC subunit could be demonstrated in normal and pathological placental tissue. The immunoreactive score (IRS) for inhibin-betaC did not show any significant differences between normal, preeclamptic, HELLP, and IUGR tissue in extravillous trophoblast and syncytiotrophoblast cells. Immunolabelling of this novel inhibin-βC protein in normal and pathological placental tissue was demonstrated, although no differences in the staining intensity could be observed. Therefore, the inhibin-βC isoform might not primarily be involved in the pathogenesis of these pregnancy-associated disorders. The functional role of this novel inhibin-betaC subunit in normal and pathological human placenta is still quite unclear and should thus be further investigated.

Keywords:

• HELLP syndrome
• immunohistochemistry
• inhibin-betaC
• IUGR
• placenta
• preeclampsia

Acknowledgments

We would like to thank Mrs. I. Krienke, Mrs. S. Kunze, Mrs S. Schulze, and Mrs. I. Wiest for their excellent work with placental samples. Moreover, we express our gratitude to Mrs. C. Kuhn and Dr. U. Jeschke for their help with the manuscript. This study was partially supported by the FöFoLe program of the Ludwig-Maximilians-University Munich (297/03), the Friedrich-Baur-Institute Munich and the Weigland Stipendium Program of the Ludwig-Maximilians-University Munich to I. M.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.