Do Oxidative Stress-Modified Exosomes Contribute to Infertility in Endometriosis?

Endometriosis affects approximately 10% of women of reproductive age and is associated with infertility in up to half of those diagnosed. Despite decades of research, the molecular basis of its reproductive consequences remains poorly defined. Among the pathophysiological features most consistently documented in affected women, chronic oxidative stress within the peritoneal cavity has attracted sustained attention, yet its relationship to the extracellular vesicle biology that has emerged as central to endometriosis pathogenesis has never been systematically examined. Iron-catalyzed radical chemistry, macrophage-derived superoxide, and mitochondrial electron leak in ectopic stromal cells collectively sustain a peritoneal redox burden that modifies exosomal biogenesis, alters microRNA sorting, and reprograms vesicle lipid and protein cargo. Oxidatively conditioned exosomes skew peritoneal macrophages toward an immunosuppressive M2 phenotype through miR-301a-3p, miR-146a-5p, and miR-196a-5p, suppress natural killer cell cytotoxicity through NKG2D ligand decoy delivery, facilitate peritoneal dissemination and neuroangiogenesis, and compromise oocyte developmental competence through ferroptosis-derived vesicles carrying aberrant miR-122-5p, oxidized phosphatidylethanolamines, and damaged mitochondria. These mechanisms map directly onto the clinical deficits observed in women with endometriosis undergoing assisted reproduction, including reduced oocyte yield, lower fertilization rates, elevated embryo aneuploidy, and impaired implantation. Follicular and peritoneal fluid exosomal microRNA profiles represent promising non-invasive biomarkers, while combinatorial strategies targeting the iron-ROS-exosome axis offer a more coherent therapeutic framework than the single-antioxidant approaches that have so far shown limited benefit.