Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Guettler, J.
Maternal platelet activation and placental endocrine activity
PhD-Studium (Doctor of Philosophy); Humanmedizin; [ Dissertation ] Medizinische Universität Graz; 2022. pp. 101
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Gauster Martin
- Marsche Gunther
- Wadsack Christian
- Altmetrics:
- Abstract:
- During early stages of human pregnancy a healthy development of the placenta is one of the crucial events to ensure a successful gestation. In first trimester maternal blood cells are restrained from entering the intervillous space (IVS) of the placenta by extravillous trophoblast plugs in the maternal spiral arteries. This ensures a low oxygen concentration which is important for a healthy development of the villous trees. In this thesis we found a new and alternative way for maternal platelets to enter the IVS of the human first trimester placenta before extravillous trophoblast plugs dissolve. These smallest blood cells were detected in intercellular gaps of distal parts of extravillous trophoblast cell columns by immunohistochemistry and transmission electron microscopy (TEM). As platelets appeared in an activated stage, it was speculated that the activation was derived from a substance found in the interstices of the extravillous trophoblasts (EVTs). However, the EVT marker HLA-G has no impact on the aggregation ability of the maternal platelets and also does not influence the adhesion of human platelets towards trophoblasts. In an archival in utero specimen of an early human pregnancy the previous stainings were confirmed and furthermore showed adhering platelets to the villous trophoblast in the IVS. In co-culture of differentiated trophoblast cell line BeWo and isolated human platelets a significant deregulation of some genes that are involved in the steroid hormone synthesis could be identified and analysis of the cell culture supernatant showed a significant decrease of the release of the pregnancy hormone progesterone. These deregulations were in concordance with known alterations in pregnancy complications and pathologies like preeclampsia (PE). In conclusion, this thesis will contribute to a deeper understanding of the interaction of fetal trophoblasts and maternal platelets in the IVS of early pregnancy.