Age and Physical Activity Modulate miRNAs contained in Human Follicular Fluid Extracellular Vesicles

Advanced maternal age decreases oocyte number and quality, impairing female fertility. Oocyte competence depends on the communication between the gamete and neighboring cells inside the follicle. Intrafollicular cells communicate by exchanging extracellular vesicle-enclosed microRNAs through the follicular fluid. Physiological and pathological systemic conditions modulate intrafollicular extracellular vesicle secretion and cargo. Thus, we hypothesize that age and physical activity modulate extracellular vesicle cargo, which may impact fertility. Therefore, we aimed to study the effect of aging and physical activity on extracellular vesicle microRNA cargo in follicular fluid and blood plasma. Both biofluids were collected from women of two age groups (young and advanced maternal age) and two physical activity groups (moderate or high). Size-exclusion chromatography was used to isolate the extracellular vesicles that presented specific markers (FLOT, ALIX101, and TSG101), exhibited small particle sizes, and had the characteristic cup-like shape. Small non-coding RNA sequencing revealed two differentially abundant miRNAs with aging (FDR < 5%). Moreover, five miRNAs significantly differed between the physical activity groups (FDR < 10%). Age-related differentially abundant miR-486-5p and miR-451a and physical activity-related differentially abundant miR-143-3p were further validated by qPCR. These miRNAs regulate genes involved in key pathways related to female reproduction (FOXO, PI3K-AKT, and estrogen signaling pathways), as well as longevity and senescence. This study shows that age and physical activity induce different alterations in extracellular vesicles microRNA cargo in follicular fluid, possibly impacting oocyte competence, shedding light on how age and physical activity may affect female infertility.