Biological Ovarian Age Predestinate Female Fecundity? Exosomes in Follicular Microenvironment Expose the Potentiality of Young

Abstract Background: This study aimed to investigate the biological functions of exosome in follicle microenvironment and illustrate the underlying mechanism about the different IVF outcomes among normal, diminished ovarian reserve (DOR) and aging female patients with the same biological ovarian age. Methods: Follicular fluid (FF) was collected from control(n=35), DOR(n=35), aging(n=35) who underwent IVF therapy in 2017 and 2018. Electron microscope and NanoSight were used to detect the exosomes morphology and concentration. Hormones levels and anti-Müllerian hormone (AMH) in the serum were detected by ELISA. Results: Serum FSH and FSH level of the DOR group and the aging group significantly increased, AFC was decreased compared to the control. Exosomes concentrations were significantly lower in DOR and aging as compared with control group and were also significantly lower in the aging group compared with the DOR group. Exosomes was negatively correlated with FSH and FSH/LH, exosomes was positively correlated with AMH. GDF9 and BMP15 were secreted by exosomes. Conclusions: Exosome was highly represented in human FF and are involved in maturation of follicle. The concentration of exosomes in FF can be an indicator of ovarian reserve. Oocytes may secrete exosomes.