Cadmium induces ferroptosis in mouse spermatocytes by activating the ROS–TCA pathway

Cadmium (Cd) can cause testis toxicity, and we have demonstrated Cd induced ferroptosis in testis. However, the underlying toxic mechanism has not yet been fully elucidated. Here, we performed in vitro experiments on a mouse spermatocyte cell line. GC–2spd cells were divided into control, Cd, and Cd+ferroptosis inhibitor groups and cultured in high-glucose DMEM for 36 h. We conducted metabolome analysis, RNA sequencing, western blot, and immunofluorescence on GC-2spd cells to determine whether Cd exposure induced ferroptosis in spermatocyte and explore the potential mechanism. The results showed Cd exposure significantly decreased cell viability. Cd exposure significantly decreased GPX4 expression but increased malondialdehyde, mitochondrial ROS, succinate, and α-ketoglutarate contents, as well as FTH1, SLC40A1, Nrf2, Ho–1, and pyruvate carboxylase expression. Ferroptosis inhibitors (deferoxamine and liproxstatin-1) partly attenuated these effects. These findings indicate that Cd exposure directly damages mitochondria and promotes excessive ROS production, causing paradoxical activation of the mitochondrial TCA cycle, which enhances ROS production and triggers ferroptosis. This study elucidates the mechanisms of Cd-induced ferroptosis in spermatocytes and provides support for future research into the impacts of Cd on the mitochondrial TCA cycle.