Abstract

Extracellular Matrix Thickness Directs Self-Assembly, Function, and Gene Expression Profiles of Three-Dimensional Placental Trophoblast Spheroids

Michael Wong, Researcher, Faculty of Health Sciences, McMaster University

The incorporation of ECM is essential for generating in vitro placental models that better mimic the architecture and function found within human tissues. However, the appropriate utilization of laboratory-derived ECM biomaterials in placental trophoblast modelling remains poorly understood. In this study, we investigated the effect of varying thicknesses of two ECM surfaces, collagen I and Matrigel, on placental trophoblast cell morphology, proliferation, and gene and protein expression. In the current study, the effect of varying thicknesses of collagen I and Matrigel on BeWo placental trophoblast cell morphology, proliferation, and gene expression (differentiation, syncytial fusion, invasion/migration) were investigated. Matrigel, but not collagen I, induced self-organization of BeWo trophoblasts into three-dimensional spheroids that maintained for up to 21 days. Notably, it was revealed that a critical hydrogel surface thickness was required to induce spheroid formation. Trophoblast spheroids exhibited thickness-dependent increases proliferation and invasive gene expression profiles compared to two-dimensional cultures. Genes involved in syncytial fusion also exhibited thickness-dependent changes in expression. In consideration of the increased use of 3D bioprinting and dynamic model systems within the last several years, proper integration of ECM surfaces will be a crucial step towards creating more in vivo-like models. The generation of 3D, self-assembling spheroid cultures through regulation of ECM surface thickness alone further contributes to the development of more physiologically-relevant placental in vitro systems and innovative drug screening tools for pregnancy.