Zidane, Mohammed Saeed: Epigenetic and exosome-mediated cell-cell communication in follicular cells and preimplantation embryos. - Bonn, 2017. - Dissertation, Rheinische Friedrich-Wilhelms-Universität Bonn.
Online-Ausgabe in bonndoc: https://nbn-resolving.org/urn:nbn:de:hbz:5n-49366
@phdthesis{handle:20.500.11811/7047,
urn: https://nbn-resolving.org/urn:nbn:de:hbz:5n-49366,
author = {{Mohammed Saeed Zidane}},
title = {Epigenetic and exosome-mediated cell-cell communication in follicular cells and preimplantation embryos},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
year = 2017,
month = dec,

volume = 187,
note = {Follicular cells and preimplantation embryos communication with their in vivo or in vitro environments via mechanisms including cell adhesion and extracellular vesicles is crucially essential for normal oocyte and embryo development and subsequently successful pregnancy. Therefore, this dissertation aims to assess the potential role of exosomes in granulosa cells’ oxidative stress response and figure out the epigenetic role of DNA methylation in the regulation of focal adhesion pathway in preimplantation embryos. For that, two main experiments were conducted; where bovine granulosa cells were cultured under oxidative stress conditions induced by H2O2. Exosomes were isolated from culture media and subjected to mRNA quantification analysis. Thereafter, control and H2O2-stressed cells were co-cultured with non-stress or stress-released exosomes. Cells of all experimental groups were subjected to ROS level, mitochondrial activity, cell cycle and cell proliferation assays as well as mRNA and protein expression analyses. In parallel, bovine embryos were cultured in media supplemented with EGF and/or HA. Blastocysts were subjected to ROS level, TUNEL, cryopreservation assays and protein analysis. Moreover, embryos were cultured in media supplemented with epidermal growth factor (EGF) and hyaluronic acid (HA) pre, post and during embryonic genome activation (EGA). Blastocysts from all groups were subjected to mRNA expression and DNA methylation analysis of genes involved in focal adhesion pathway. Results revealed that, H2O2-induced oxidative stress significantly increased ROS level as well as mRNA and protein expression of Nrf2 and antioxidant genes. Stress-released exosomes were enriched with mRNA of Nrf2 and selective antioxidants (CAT, and TXN1). Granulosa cells co-cultured with stress-released exosomes exhibited higher mRNA and protein levels of Nrf2 and its downstream antioxidants which in turn reduced ROS level and enhanced mitochondrial activity and cell proliferation under oxidative stress conditions. Furthermore, culture media supplemented with EGF and/or HA altered the DNA methylation pattern of genes involved in focal adhesion pathway associated with significant high mRNA and protein levels. The supplementation of EGF and HA particularly during EGA had a positive effect on mRNA expression of focal adhesion genes. Blastocysts with higher focal adhesion mRNA and protein levels had low ROS level and apoptosis with high cryotolerance. These findings highlighted the role of exosomes and DNA methylation in cell-cell communications and subsequently cell function and embryo quality under suboptimal conditions.},
url = {https://hdl.handle.net/20.500.11811/7047}
}

Die folgenden Nutzungsbestimmungen sind mit dieser Ressource verbunden:

InCopyright