Molecular mechanism of testicular oxidative stress-induced ferroptosis in Leydig cells caused by cryptorchidism in yak

Cryptorchidism is a prevalent reproductive disorder triggering severe testicular damage and male infertility. However, the underlying molecular mechanism in plateau yaks remains largely unclear. This study explored the pathogenesis of androgen deficiency and Leydig cell Ferroptosis induced by yak cryptorchidism, and illuminated the relevant regulatory pathways. Testicular specimens were collected from healthy and cryptorchid yaks, the Leydig cells were isolated, purified and cultured in vitro combined with the histopathological staining, immunofluorescence, Western blotting and ELISA were conducted to detect markers of oxidative stress (OS), Ferroptosis, androgen synthesis and related signaling pathways.The results demonstrated that cryptorchid yaks exhibited impaired testicular histomorphology, decreased testosterone and dihydrotestosterone (DHT) levels, and downregulated expression of STAR, CYP11A1 and Androgen Receptor (AR). Cryptorchidism also aggravated testicular OS, inactivated the Nrf-2/Keap-1 pathway, and induced obvious iron overload and Ferroptosis in Leydig cells via disrupting the GPx4/FPN1/FTL axis. In vitro assays verified that H₂O₂-induced OS accelerated Leydig cell Ferroptosis by inhibiting the Nrf-2/Keap-1 pathway, while NAC, Fer-1 and DHT effectively mitigated such lesions, with DHT exerting effects via AR activation. This study clarifies that yak cryptorchidism induces OS, suppresses the Nrf-2/Keap-1 pathway, triggers Leydig cell Ferroptosis and androgen secretion disorders, offering novel molecular targets for yak cryptorchidism prevention and treatment.