Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women at reproductive age. However, the underlying pathogenic mechanisms have not been completely understood. Hyperandrogenism is an important clinic feature in patients with PCOS, suggesting its pathologic role in the development and progression of PCOS. However, the actual role of androgen and the related signals in PCOS and PCOS‐related complications have not yet been clarified. In this review, we surveyed the origin and effects of androgen on PCOS and the related complications, highlighted the cellular signals affecting androgen synthesis and summarized the pathological processes caused by hyperandrogenism. Our review well reveals the important mechanisms referring the pathogenesis of PCOS and provides important clues to the clinic strategies in patients with PCOS.

Epithelial-mesenchymal transition (EMT) is known to play a crucial role in the development of endometriosis (EMs). However, the exact mechanisms involved in EMT regulation in EMs are not well understood. In this study, we performed comprehensive research using clinical samples, single-cell sequencing, and in vivo/in vitro models to investigate the effects of advanced oxidation protein products (AOPPs) on EMT and the underlying mechanisms in EMs. Combining bioinformatics analysis with experimental validation, our results show that AOPPs accumulate in EMs tissues, and their levels positively correlate with the expression of EMT markers in fibrotic lesions of EMs patients. Stimulation with AOPPs leads to a concentration- and time-dependent alteration of EMT markers expression in both in vitro and in vivo models. These effects are mainly mediated by the generation of reactive oxygen species and nitrite, along with the activation of the ERK and P38 signaling pathways. In chronic administration studies using normal rats, AOPPs induce EMT and enhance collagen deposition. These findings significantly contribute to our understanding of the molecular mechanisms of EMs and provide a foundation for future research and therapeutic development in this field.