Effect of sphingosine-1-phosphate supplementation on follicular integrity of vitrified–warmed mouse ovarian grafts

ObjectiveTo investigates the effect of sphingosine-1-phosphate (S1P) supplementation on follicular integrity and apoptosis in vitrified–warmed mouse ovarian grafts.Study designOvaries from 4-week-aged ICR mice were vitrified using a vitrification solution with or without 2 μM S1P. After warming, follicular normality was assessed by histological analysis and TUNEL assay. A part of ovaries vitrified with or without 2 μM S1P was transplanted, and 2 weeks later, gross and microscopic follicular morphology was assessed.ResultsDuring vitrification and warming, inclusion of 2 μM S1P into the vitrification solution significantly raised the rate of morphologically intact follicles compared to controls (36.6% vs. 30.8%, p = 0.047). This protective effect was profound especially in primordial follicles (45.5% vs. 34.6%, p = 0.034). After transplantation of vitrified–warmed ovaries, the morphological integrity of primordial follicles was superior in the S1P-treated group (55.0% vs. 39.4%, p = 0.035). The rates of non-apoptotic follicles (TUNEL-negative) were similar in the two groups in either non-transplanted or transplanted ovaries.ConclusionInclusion of S1P in the vitrification solution during transplantation of vitrified–warmed ovary had a beneficial effect on preservation of the primordial follicular pool.