microfluidic chip to study human trophoblast invasion during implantation

A microenigneered system models multicellular events in early pregnancy


“Successful establishment of pregnancy requires adhesion of an embryo to the endometrium and subsequent invasion into the maternal tissue. Abnormalities in this critical process of implantation and placentation lead to many pregnancy complications. Here we present a microenigneered system to model a complex sequence of orchestrated multicellular events that plays an essential role in early pregnancy. Our implantation-on-a-chip is capable of reconstructing the three-dimensional structural organization of the maternal-fetal interface to model the invasion of specialized fetal extravillous trophoblasts into the maternal uterus. Using primary human cells isolated from clinical specimens, we demonstrate in vivo-like directional migration of extravillous trophoblasts towards a microengineered maternal vessel and their interactions with the endothelium necessary for vascular remodeling. Through parametric variation of the cellular microenvironment and proteomic analysis of microengineered tissues, we show the important role of decidualized stromal cells as a regulator of extravillous trophoblast migration. Furthermore, our study reveals previously unknown effects of pre-implantation maternal immune cells on extravillous trophoblast invasion. This work represents a significant advance in our ability to model early human pregnancy, and may enable the development of advanced in vitro platforms for basic and clinical research of human reproduction.

a Soon after implantation, EVTs begin to differentiate from precursor cells in the cytotrophoblast shell (CS) and invade into the uterus, a process that continues through the first half of pregnancy. b Compartmentalized design of the implantation-on-a-chip device for in vitro modeling of EVTs and a maternal SA separated by maternal endometrium. c Architecture of the implantation-on-a-chip microdevice. The center and two side lanes have dimensions of 0.5 mm (width) × 0.3 mm (height) and 0.25 mm (width) × 0.3 mm (height), respectively. d Sequential steps of model construction. e Time-lapse imaging of ECM hydrogel precursor (colored black) injection into the center lane of the device. f Images of device cross-section to show capillary pinning-based physical confinement of injected hydrogel solution (dark solution) in the center lane. Scale bar, 500 μm g (Top row) Photos of first trimester termination tissue and EVT outgrowth from the tissue explants. Scale bars, 1 mm (middle) and 200 μm (right). (Bottom row) The purity of the population was confirmed by immunostaining for cytokeratin 7, a trophoblast marker (magenta) and HLA-G, an EVT-specific marker (green). The representative images of the villous tissue are from five independent experiments. Scale bars, 200 μm. h Immunostaining of HLA-G (green) and Ki67 (magenta) expression by EVTs cultured on coverslips in a 6 well plate, after 3 passages. The representative images of EVTs are from four independent experiments. Scale bars, 50 μm. i Top-down confocal projection of the microengineered maternal-fetal interface at Day 1. EVTs in the fetal chamber were labeled with CellTracker Green (green). ECs were stained for VE-cadherin (magenta). The representative image is from three independent devices. Scale bar, 200 μm. j Endothelial tube in the vascular compartment at Day 1. Magenta and blue show VE-cadherin and nuclear staining, respectively. The representative images are from three independent devices. Scale bars, 100 μm (top) and 50 μm (bottom). EVTs: Extravillous trophoblasts, CS: Cytotrophoblastic shell, ECs: Endothelial cells, ECM: Extracellular matrix, CK7: Cytokerain 7, HLA-G: human leukocyte antigen G.. Reproduced under Creative Commons Attribution 4.0 International License from Park, J.Y., Mani, S., Clair, G. et al. A microphysiological model of human trophoblast invasion during implantation. Nat Commun 13, 1252 (2022).

Figures and the abstract are reproduced from Park, J.Y., Mani, S., Clair, G. et al. A microphysiological model of human trophoblast invasion during implantation. Nat Commun 13, 1252 (2022). https://doi.org/10.1038/s41467-022-28663-4 under Creative Commons Attribution 4.0 International License.

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A microphysiological model of human trophoblast invasion during implantation