Extracellular vesicles released by uterine fibroid cells: modulation by omega-3 fatty acids and impact on recipient myometrial cells

Objective: To study the effects of extracellular vesicles (EVs) derived from primary myometrial and leiomyoma cells, as well as suitable cell lines, and to evaluate the release of EVs after omega-3 fatty acid treatment and their impact on fibronectin protein expression in recipient myometrial cells. Design: Case-control laboratory study. Setting: University institute and university hospital. Subjects: Patients with uterine fibroids. Exposure: Primary cells were obtained from uterine tissue samples (leiomyoma and healthy myometrium) of premenopausal women (41-49 years) undergoing surgery. Immortalized myometrial (A00-9) and leiomyoma (A00-10) cell lines were also used. Main outcome measure: Cross-sectional in vitro study comparing untreated and omega-3-treated primary and immortalized myometrial and leiomyoma cells. Extracellular vesicles were isolated after 48 hours of treatment, characterized by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM), and then used to treat myometrial cell lines. Fibronectin expression was measured in recipient cells. Results: Extracellular vesicles were isolated and fractionated into small (s) and large (l) EVs. Small extracellular vesicle release was significantly induced by eicosapentaenoic acid treatment. These vesicles derived from leiomyoma cells showed a trend toward increased fibronectin expression in recipient myometrial cells, whereas EVs from omega-3-treated leiomyoma cells showed attenuated effects. Those from myometrial cells, treated or untreated, did not alter fibronectin expression. Results were consistent across biological replicates (n = 3). Conclusion (s): These data suggest that leiomyoma-derived EVs contribute to fibrotic changes in surrounding myometrium and that omega-3 fatty acids can modulate EV release and EV-mediated profibrotic signaling. This may represent a potential proof-of-concept strategy for managing fibroid-associated fibrosis, although further in vivo validation is required.