Cellular and extracellular miRNA profiles of pre-ovulatory follicles indicate signalling disturbances in polycystic ovaries

Cell-free RNAs have been used as diagnostic disease markers describing the state of tissue environment. The origin and potential functions of such RNAs in human pre-ovulatory follicle, the environment of oocyte maturation, are unclear. We aimed to describe the small RNA profiles of three follicular compartments of the same follicle: mural granulosa cells (MGC), cell-free follicular fluid (FF) and extracellular vesicles (EV) of the FF. Focusing on microRNAs, their signatures and regulated pathways were compared between infertile women with polycystic ovaries and fertile control group. Overall design: miRNA profiles of pre-ovulatory follicle mural granulosa, whole cell-free follicular fluid and extracellular vesicles of the follicular fluid