Abstract
Human uterine fibroblasts (HuF) isolated from the maternal part (decidua parietalis) of a term placenta provide a useful model of in vitro cell differentiation into decidual cells (decidualization, a critical process for successful pregnancy). After isolation, the cells adhere to plastic and have either a small round or spindle-shaped morphology that later changes into a flattened pattern in culture. HuF robustly proliferate in culture until passage 20 and form colonies when plated at low densities. The cells express the mesenchymal cell markers fibronectin, integrin-beta1, ICAM-1 (CD54), and collagen I. Flow cytometry of HuF has detected the presence of CD34, a marker of the hematopoietic stem cell lineage, and an absence of CD10, CD11b/Mac, CD14, CD45, and HLA type II. Furthermore, they also express the pluripotency markers SSEA-1, SSEA-4, Oct-4, Stro-1, and TRA-1-81 as detected by confocal microscopy. Treatment for 14-21 days with differentiation-inducing media leads to the differentiation of HuF into osteoblasts, adipocytes, and chondrocytes. The presence of alpha-smooth muscle actin, calponin, and myosin light-chain kinase in cultured HuF implies their similarity to myofibroblasts. Treatment of the HuF with dimethyl sufoxide causes reversion to the spindle-shaped morphology and a loss of myofibroblast characteristics, suggesting a switch into a less differentiated phenotype. The unique abilities of HuF to exhibit multipotency, even with myofibroblast characteristics, and their ready availability and low maintenance requirements make them an interesting cell model for further exploration as a possible tool for regenerative medicine.