Preeclampsia is a cardiovascular disorder of pregnancy without a cure, in part due to the lack of reliable model systems for the investigation of human pregnancy. In our recent work we developed and utilised a three-dimensional (3D), bioprinted, trophoblast organoid model for studying aspects of placental development and function during pregnancy. We then aimed to employ this model to study the effects of current and emerging treatments of preeclampsia; namely aspirin, metformin and mesenchymal stem/stromal cell-derived extracellular vesicles (MSC-EVs), on trophoblast function.
First trimester trophoblast cells, ACH-3P (1), were used to generate 3D organoids using a RASTRUM bioprinter (Inventia Life Science) and normal culture medium for up to 12 days. After 5 days, select wells were treated with TNF-α (10ng/ml), a cytokine increased in preeclampsia (2,3), to induce an inflammatory environment. On Day 8, aspirin (0.5mM), metformin (0.5mM) or MSC-EVs (10µg/well) were added to wells +/- TNF-α. Organoid growth and cell viability was captured using an IncuCyte. Harvested and fixed organoids were immunolabelled for trophoblast subtype-specific markers E-cadherin, human leukocyte antigen (HLA-G) and β human chorionic gonadotropin (β-hCG).
Cells encapsulated within a polyethylene glycol (PEG)-based hydrogel self-formed organoids over 12 days, demonstrating invasive capabilities within the matrix. There was no significant difference in the organoid area between treatment groups (p>0.05). Similarly, there was no significant difference in the viability of cells treated with each condition (p>0.05), confirming that the treatments were not toxic to the trophoblast cells. Villous cytotrophoblast, extravillous trophoblast and syncytiotrophoblast populations were confirmed by fluorescent confocal microscopy.
Our novel 3D trophoblast organoid model recapitulated key trophoblast subtypes of early placental tissue. Preliminary results showed no significant influence of aspirin, metformin or MSC-EVs on the viability or proliferation of trophoblasts was noted. We intend to further study their effects on trophoblast differentiation and invasion relevant to placental development.