Objective: Attempting in vivo healing of cyclophosphamide-induced ovarian insufficiency in a mouse model using bone marrow mesenchymal stem cells (BMMSCs).
Methods: Female BALB/c white mice were used to prepare a model for premature ovarian failure by single intraperitoneal injection of cyclophosphamide (80 mg/kg). Ten mice were injected with BMMSCs and then sacrificed after 21 days for morphometric evaluation of the ovaries. Hormonal profile was evaluated while mice were being sacrificed. Another 10 mice were left for natural breeding with male mice, and 5 of these were injected with BMMSCs. Oocyte-like structures were obtained from 3 mice and were subjected to in vitro fertilization/intracytoplasmic sperm injection.
Results: Morphometric analysis of the ovaries demonstrated the presence of newly formed primordial follicles. Contribution of MSCs to the formation of these follicles was proven by a labeling technique. There was a drop in estradiol and rise in follicle-stimulating hormone levels, followed by resumption of the hormonal levels to near normal 21 days after MSCs therapy. The 5 mice that were injected with MSCs became pregnant after natural breeding. Fertilization and further division was reported in 5 oocytes subjected to intracytoplasmic sperm injection, but division did not continue.
Conclusion: From this proof-of-concept trial, we can say that healing of damaged ovaries after chemotherapy in mice is possible using in vivo therapy with BMMSCs. This should open the gate for a series of animal studies that test the possibility of in vitro maturation of germinal epithelium of the ovary into mature oocytes.
Keywords: POF; cyclophosphamide; ovarian insufficiency; stem cell.