Arsenic exposure reduces testosterone synthesis partially by evoking Leydig cell ferroptosis in mouse testes

Accumulating data have demonstrated that long-term arsenic (As) exposure reduces testicular testosterone (T) synthesis. This study investigated the contribution of Leydig cell ferroptosis to As-impaired testicular T synthesis. Adult male C57BL/6J mice received NaAsO₂ (0, 1.5, or 15 mg/L) by drinking water. As-exposed mice exhibited suppressed serum and testicular T levels with concomitant downregulation of T synthases. The number of Leydig cells, as determined by histopathology, immunohistochemistry, and immunofluorescence, was reduced in As-exposed mouse testes. Transcriptomic profiling identified ferroptosis as a significantly enriched pathway among differentially expressed genes (DEGs). Free ferrous ions were increased, and MDA and 4-HNE, two markers of lipid peroxidation, were elevated in As-exposed mouse testes. ACSL4 and NCOA4, two initiators of ferroptosis, were upregulated, and GPX4, a key ferroptosis repressor, was diminished in As-exposed mouse testes. Liproxstatin-1 (Lip-1), a specific ferroptosis inhibitor, protected against As-induced testicular Leydig cell ferroptosis. Moreover, pretreatment with Lip-1 attenuated As-induced declined of T synthases in mouse testes. Accordingly, Lip-1 pretreatment reversed As-induced reduction of testicular T synthesis. These results suggest that As exposure reduces testicular T synthesis partially by evoking Leydig cell ferroptosis in mouse testes.