Proteomic Analysis of Human Follicular Fluid-Derived Exosomes Reveals That Insufficient Folliculogenesis in Aging Women is Associated With Infertility

Although the risk of female infertility increases with advancing age, the underlying mechanisms remain unknown. Exosomes in follicular fluid are suggested to regulate folliculogenesis and influence oocyte quality, potentially playing a critical role in age-related infertility. Elucidating their content could enhance the understanding of the molecular mechanisms associated with female aging-induced infertility. In this study, we explored the proteomic profiles of exosomes derived from human follicular fluid to identify protein signatures associated with infertility in both young and aging women. Despite the lack of significant differences in the morphology and particle size of follicular fluid-derived exosomes between the two groups, proteomic analysis revealed a distinct pattern of differentially expressed proteins (DEPs). DEPs associated with B-cell activation, pathogen invasion, and disrupted metabolic processes were significantly more highly expressed in the aging group than in the young group, indicating their involvement in age-related infertility. In vivo experiments demonstrated that the application of exosomes, particularly those derived from young female group, facilitated the successful maturation of follicles. Key exosomal proteins, including ENO1, HSP90B1, fetuin-B, C7, and APOC4, were found to be associated with follicular maturation. Furthermore, the PI3K/AKT signaling pathway, which is known to be related to folliculogenesis, was activated by the application of exosomes in aging female mice. This study provides novel insights into the aging-associated protein signatures of follicular fluid-derived exosomes and their potential role in infertility. These findings suggest that aging-related protein signatures in exosomes could contribute to the treatment of age-related infertility.