KLF5 drives granulosa cell apoptosis and inflammatory injury in polycystic ovary syndrome via transcriptional activation of TXNIP.

Polycystic ovary syndrome (PCOS), a common endocrine disorder affecting over 10% of women, is characterized by hyperandrogenism and ovarian dysfunction. While linked to chronic inflammation and granulosa cell apoptosis, its molecular mechanisms remain unclear. In this study, we elucidated the novel role of Krüppel-like factor 5 (KLF5) in the pathogenesis of PCOS and its regulatory role with thioredoxin interacting protein (TXNIP). In a mouse model of PCOS induced by dehydroepiandrosterone (DHEA), KLF5 expression was significantly elevated in ovarian tissues (up-regulated 2.62-fold, P < 0.001), correlating with hyperandrogenism (testosterone: up-regulated 2.83-fold, P < 0.001) and cystic follicle formation. The proliferative capacity of testosterone-treated KGN cells was reduced to 59% after KLF5 was knocked down (P < 0.01), attenuated apoptosis by inhibiting the increase of Bax and Cleaved-caspase 3 proteins and thus attenuated inflammation by down-regulating NLRP3 and Interleukin- (IL-) 1β. Most importantly, dual luciferase assay showed that KLF5 transcriptionally activated TXNIP, resulting in a 3.04-fold enhancement of its promoter activity (P < 0.001). Meanwhile, overexpression of TXNIP reversed the silencing effect of KLF5, resulting in a significant increase in apoptosis and secretion of inflammatory factors. These results reveal a previously unrecognized KLF5/TXNIP axis driving granulosa cell (GC) dysfunction in polycystic ovary syndrome, in which KLF5 transcriptionally upregulates TXNIP to promote apoptosis and NLRP3 inflammasome activation. Our findings provide the first evidence linking KLF5 to the pathogenesis of PCOS and establish this pathway as a potential therapeutic target, bridging a significant gap in understanding the molecular basis of the disease and providing compelling evidence for clinical drug development.