A novel in vitro model of the early endometriotic lesion demonstrates that attachment of endometrial cells to mesothelial cells is dependent on the source of endometrial cells

Objective: To characterize the source of variability in endometrial stromal cell (ESC) binding to peritoneal mesothelial cells (PMC). Design: In vitro study. Setting: University medical center. Patient(s): Reproductive-age women without endometriosis undergoing surgery for benign conditions. Intervention(s): None. Main Outcome Measure(s): Binding of ESCs (n = 9) to PMCs collected from the anterior abdominal wall (AAW) (n = 5), a commercially available mesothelial cell line (LP9) (three different passages) and normal ovarian surface epithelium (NOSE) (n = 5). Result(s): There were no differences in the binding of same-source ESCs to mesothelial cells obtained from the AAW of different women, to different passages of LP9s or to NOSE of different women. There was a trend toward increased binding of ESCs to NOSE compared to AAW PMCs. In contrast, there were significant differences in the ability of ESCs obtained from different women to bind to same-source PMCs. Conclusion(s): There is significant variability in ESC binding to PMCs. This variation is dependent primarily on the source of the ESCs. The ESC binding to LP9 PMCs was similar to AAW PMCs and NOSE.