The Role of Matrix Macromolecules in the Invasion of Decidua by Trophoblast: Model Studies Using BeWo Cells

Abstract

Light and electron microscopic studies of the human placental bed suggest that the invasion of trophoblast into decidua depends in some measure on interaction with decidual extracellular matrix (Boyd and Hamilton, 1970; Pijnenborg et al., 1980). This applies both to the initial stages of interstitial implantation and to the invasion of decidual stroma and arteries that occurs during the late first and second trimesters of pregnancy (Pijnenborg et al, 1980; Sheppard and Bonnar, 1974). One important aspect of this phenomenon is the inherent invasiveness of trophoblast. However, it is clear that many - even most - cell types, given a suitable environment, have a capacity to migrate across surfaces (Abercrombie, 1980) and some cells also invade and migrate through three- dimensional matrices (Mareel, 1979; Schor, 1980; Schor et al, 1981; Jones et al, 1981). The expression of these properties depends on the relationship of each cell to its neighbors, that is, on cell-cell contacts (Aplin and Foden, 1985; Schor et al, 1985), and also on the surrounding extracellular matrix (Glass et al, 1983; Jones et al, 1981; Schor et al, 1981). The matrix provides a structural framework for the tissue, but many of its components are also used by cells as anchors against which to exert tractional forces during movement (Harris et al, 1981). These cell-matrix interactions are mediated by specific plasma membrane receptor molecules (Hynes, 1987; Argraves et al, 1987; Wayner and Carter, 1987) that interact with matrix components outside the cell and signal the reorganization of the cytoskeleton required for change of shape. Shape change is, in turn, a prerequisite of motility (Abercrombie, 1980).