Background: Fibroblast growth factors (FGFs), in complex with their receptors (FGFRs), regulate a broad spectrum of biological functions including cellular proliferation, survival, migration, and differentiation. In human endometrial stromal cells, FGF9 is regulated with estrogen (E).
Methods/results: First, we report that in uterus tissue of ovariectomized wild type mice, FGF9 is present in three isoforms and is regulated with E. Second, we found that during peri-implantation, Fgf9 expression reached its peak at day 4.5 of pregnancy. Immunofluorescence analyses demonstrated overlapping FGF9 and COX2 expression surrounding the blastocyst attachment site. Next, we identified FGF9- and CD31-positive cells as a part of the microvessels; however, expression was localized to a distinct population of cells. Finally, our data showed synchronized, spatial expression of FGF9 on the luminal epithelium with FGFR2 present on the trophectoderm.
Conclusion: Our data suggest that FGF9 is a crucial factor required to establish the appropriate microenvironment for successful implantation and the maintenance of pregnancy.
Keywords: Angiogenesis; Fibroblast growth factor 9 (FGF9); Fibroblast growth factor receptor (FGFR); Implantation.
© 2017 The Author(s). Published by S. Karger AG, Basel.