Human endometrial mesenchymal stem cells restore ovarian function through improving the renewal of germline stem cells in a mouse model of premature ovarian failure

Abstract

Background: Human endometrial mesenchymal stem cells (EnSCs) derived from menstrual blood have mesenchymal stem/stromal cells (MSCs) characteristics and can differentiate into cell types that arise from all three germ layers. We hypothesized that EnSCs may offer promise for restoration of ovarian dysfunction associated with premature ovarian failure/insufficiency (POF/POI). Methods: Mouse ovaries were injured with busulfan and cyclophosphamide (B/C) to create a damaged ovary mouse model. Transplanted EnSCs were injected into the tail vein of sterilized mice (Chemoablated with EnSCs group; n = 80), or culture medium was injected into the sterilized mice via the tail vein as chemoablated group (n = 80). Non-sterilized mice were untreated controls (n = 80). Overall ovarian function was measured using vaginal smears, live imaging, mating trials and immunohistochemical techniques. Results: EnSCs transplantation increased body weight and improved estrous cyclicity as well as restored fertility in sterilized mice. Migration and localization of GFP-labeled EnSCs as measured by live imaging and immunofluorescent methods indicated that GFP-labeled cells were undetectable 48 h after cell transplantation, but were later detected in and localized to the ovarian stroma. 5'-bromodeoxyuridine (BrdU) and mouse vasa homologue (MVH) protein double-positive cells were immunohistochemically detected in mouse ovaries, and EnSC transplantation reduced depletion of the germline stem cell (GSCs) pool induced by chemotherapy. Conclusion: EnSCs derived from menstrual blood, as autologous stem cells, may restore damaged ovarian function and offer a suitable clinical strategy for regenerative medicine.