Introduction: Preeclampsia affects 5-8% of pregnancies and is the leading cause of maternal and foetal death in pregnancy. Despite this, there are still no effective prevention or treatment strategies. The root cause of preeclampsia is placental dysfunction, however, research into the mechanisms of pathogenesis has been impeded by a lack of reliable models of the human disease. Inadequate trophoblast remodelling of maternal uterine arteries is a major contributing factor in the development of preeclampsia. Thus, a low-cost and reproducible 3D migration and invasion trophoblast model would be transformative for future research and could lead to better management of preeclampsia.
Aim: To establish a novel 3D cell model of the early placenta using a custom-made first trimester trophoblast cell line.
Methods/Results: Organoids were generated by manual seeding of trophoblasts in Matrigel or bioprinting using a RASTRUM 3D cell culture platform and cultured with normal growth medium. Live cell imaging revealed spontaneous organoid formation from single cells within a few days. Trophoblast organoids demonstrated invasive capabilities within the matrix and the emergence of single cells. For histological analysis, a subset of organoids were harvested and processed for haematoxylin and eosin staining. To evaluate the differentiated cell morphologies within the organoids, another subset of organoids were fixed in situ and probed with immunofluorescence antibodies against subtype-specific markers including E-cadherin for villous trophoblasts and human leukocyte antigen G (HLA-G) for extravillous trophoblasts.
Conclusions: Our novel 3D trophoblast organoid model recapitulates key trophoblast subtypes of early placental tissue. In particular, the spontaneous differentiation of trophoblast subtypes within these organoids presents an opportunity to investigate key mechanisms involved in trophoblast proliferation, differentiation and cellular function important for placental development. Further, this 3D first trimester trophoblast model could lend significant insight into the key features of placental dysfunction, such as that seen in infertility, miscarriage and preeclampsia.