Cortisol’s Effect on Iron Transport Proteins and Extracellular Vesicles Derived from Placental Trophoblast Cells
Open Access
- Author:
- Anderlind, Sophie
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Nikki Crowley, Thesis Supervisor
Stephen Wade Schaeffer, Thesis Honors Advisor - Keywords:
- Trophoblast Cells
Cortisol
Iron Transport Proteins
Extracellular Vesicles
TFR-1
FPN-1
Iron Trafficking
Pregnancy - Abstract:
- The importance of the placenta is often underrepresented, despite its critical role in the transfer of oxygen and nutrients to the fetal bloodstream. Iron is a prominent nutrient necessary for general development, and inadequate levels have been associated with pregnancy complications and fetal developmental impairments. Cortisol is a stress-induced hormone found to correlate with iron levels in the blood and placenta, however, there are limited studies examining the effects of prolonged and excessive cortisol exposures on iron transport proteins and the extracellular vesicles (EVs) that transport these proteins. EVs are utilized by all cell types and function as intercellular communicators containing bioactive cargo released during both normal and pathological cellular activities. Our experiment's first aim was to determine the effects of cortisol exposure in trophoblast placental cell-derived iron transport proteins, Transferrin Receptor 1 (TFR-1), and Ferroportin 1 (FPN-1). The second aim was to effectively isolate EVs from control and cortisol-exposed trophoblasts to examine whether the iron transport proteins are associated with EVs. We hypothesized that cortisol-exposed cells would express fewer target proteins than control cells and these proteins will be present and downregulated in EVs upon cortisol exposure. The experiments were conducted by culturing the BeWo placental trophoblast cell line. We first performed a dose-response study, to assess cell viability and death after cortisol exposure using Cell Counting Kit-8 (CCK8) and Lactate Dehydrogenase (LDH) assays, respectively. Size exclusion chromatography was then utilized to separate EVs from the conditioned cell culture media of control and cortisol exposed BeWo cells. The target proteins of the cell lysate and EV samples were subsequently identified through western blotting. Our preliminary data suggest that TFR-1 expression is upregulated, and FPN-1 expression is downregulated, in cells exposed to cortisol. While EV-associated TFR-1 was present in both the control and cortisol-exposed samples, FPN-1 was exclusively present in control samples. Because TFR-1 is an iron importer and FPN-1 is an iron exporter, these findings may indicate an iron accumulation within the trophoblast layer of the placenta. Iron accumulations can cause oxidative stress or hypoxia among varying cell types, so prolonged excessive cortisol exposure may adversely affect the placenta.