Human ovarian extracellular vesicles proteome from polycystic ovary syndrome patients associate with follicular development alterations

The development of the ovarian follicle requires the presence of several factors that come from the blood and follicular cells. Among these factors, extracellular vesicles (EVs) represent an original communication pathway inside the ovarian follicle. Recently, EVs have been shown to play potential roles in follicular development and reproduction-related disorders, including the polycystic ovary syndrome (PCOS). The proteomic analysis of sEVs isolated from FF in comparison to sEVs purified from plasma has shown a specific pattern of proteins secreted by ovarian steroidogenic cells such as granulosa cells. Thus, a human granulosa cell line exposed to sEVs from FF of normal patients increased their progesterone, estradiol, and testosterone secretion. However, if the sEVs were derived from FF of PCOS patients, the activity of stimulating progesterone production was lost. Stimulation of steroidogenesis by sEVs was associated with an increase in the expression of the StAR gene. In addition, sEVs from FF increased cell proliferation and migration of granulosa cells, and this phenomenon was amplified if sEVs were derived from PCOS patients. Interestingly, STAT3 is a protein overexpressed in sEVs from PCOS patients interacting with most of the cluster of proteins involved in the phenotype observed (cell proliferation, migration, and steroid production) in granulosa cells. In conclusion, this study has demonstrated that sEVs derived from FF could regulate directly the granulosa cell activity. The protein content in sEVs from FF is different in the case of PCOS syndrome and could perturb the granulosa cell functions, including inflammation, steroidogenesis, and cytoskeleton architecture.