Ozone exposure at environmental level induces female reproductive impairment via transcriptomic and alternative...

Ozone (O₃) exposure caused oxidative damage, which released inflammatory biomarkers into the circulation, triggered systemic effects that disrupted female hormonal levels and impacted the reproductive system, but its underlying mechanisms remained unclear. In this study, adult female Balb/c mice were exposed to environmental level O₃ concentrations (0.5 and 1.0 ppm) for 28 days. The results revealed histopathological damage in uterus and ovary tissues, accompanied by significantly decreased serum levels of estradiol, progesterone, and anti-Müllerian hormone. Transcriptomic analysis uncovered O₃-mediated dysregulation of the uterine immune regulatory network and abnormalities in ovarian steroid hormone metabolic pathways. Through prognostic survival analysis based on The Cancer Genome Atlas (TCGA) and validation via quantitative real-time PCR experiments, we identified seven genes associated with O₃-induced uterine pathology and two genes linked to ovarian dysfunction. Alternative splicing analysis further demonstrated that O₃ triggered aberrant splicing events in Mitogen-activated protein kinase 8 (Mapk8) and Glycogen synthase kinase 3β (Gsk3b). This disrupted the expression of the uterus hub genes DNA damage inducible transcript 4 (Ddit4) and Interleukin 1 alpha (Il1a), thereby contributing to the induction of uterine disorders. In the ovary, O₃ exposure caused exon skipping in the Follicle-stimulating hormone receptor (Fshr) gene. This resulted in altered expression of its interacting hub gene Steroidogenic acute regulatory protein (Star), thus modulating the pathogenesis of ovarian disorders. This study elucidated that O₃ exposure synergistically increases the risk of uterine and ovarian disorders through multiple mechanisms, including disrupting hormonal balance, compromising immune homeostasis, and dysregulating gene expression and RNA splicing, thus providing new experimental evidence for assessing the hazards of O₃ exposure to female reproductive health.