Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Mehic, D.
Characterization of isolated human trophoblastic extracellular vesicles
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2018. pp. 62
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Hirschmugl Birgit
- Wadsack Christian
- Altmetrics:
- Abstract:
- Background: Trophoblastic cells of the human placenta release extracellular vesicles into the maternal blood. To date, the knowledge regarding human trophoblastic extracellular vesicles and in addition extracellular vesicles released to the fetus, especially exosomes, is sparse and insufficient. Different studies suggest an association between exosomes and pathophysiological occurrences during pregnancy. Extracellular vesicles may play an important role in intercellular communication. A better understanding of the composition of extracellular vesicles is therefore fundamental. Hypothesis: The protein profile of placental exosomes may not only influence their size and function. It might also effect systemic trafficking and responses of target cells. We are expecting to detect specific proteins on placental exosomes isolated from maternal plasma and feto-placental perfusates. In addition, an association between the composition of these extracellular vesicles and the function of the placenta is of interest. Methods: We used maternal and fetal plasma as well as maternal perfusate for our investigations. The isolation of exosomes from perfusates was performed out of collected samples from ex-vivo dual placental perfusion experiments. We subsequently isolated the exosomes by differential centrifugation and density gradient steps. The detection of specific exosomal and placental proteins were achieved by employing western blot analyses with antibodies targeting specific proteins of the vesicles. Results: We could confirm that no placental-specific extracellular vesicles are detectable within fetal plasma. Regarding the maternal perfusate, there is a correlation between the extracellular vesicles and placental origin. In all isolated exosomal fractions specific proteins namely PLAP, Syntenin, TSG101, and CD63 could be detected. In contrast, other assessed proteins revealed a different result. Interestingly, Integrin alpha 6 and Annexin A2 proteins supposed to be expressed on all extracellular vesicles could only be detected on microvesicles but not on placental exosomes. Conclusion: Due to its different size and protein composition, we were able to characterize human placental microvesicles and exosomes. An exact assignment of the associated and assessed proteins is - based on the particle size distribution and similar biogenesis - not possible. It is of high importance that further investigations are carried out as there is still a lack of understanding regarding specific placenta derived exosomes and their characteristics. It still remains unclear if proteins of placental extracellular vesicles are interacting with targeted cells.