ORIGINAL ABSTRACT

Glyphosate (GLY), a widely used herbicide, can adversely affect the male reproductive health by inhibiting testosterone synthesis. Ferroptosis is a form of iron-dependent oxidative cell death that contributes to inhibition of testosterone secretion. However, it still remains unclear whether ferroptosis is involved in GLY-inhibited testosterone synthesis. Hereby, an in vitro model of 1 mM GLY-exposed testicular Leydig (TM3) cells was established to elucidate this issue. Data firstly showed that GLY causes cytotoxicity and testosterone synthesis inhibition via ferroptosis, while accumulation of lipid peroxides due to intracellular ferrous ion (Fe2+) overload and glutathione depletion is confirmed as a determinant of ferroptosis. Blockage of ferroptosis via chelation of Fe2+ or inhibition of lipid peroxidation can markedly mitigate GLY-induced testosterone synthesis inhibition. Also, autophagy activation is revealed in GLY-treated TM3 cells and nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy is involved in ferroptosis through the release of excess Fe2+. GLY-induced cytotoxicity and testosterone synthesis inhibition are significantly alleviated by NCOA4 knockdown, demonstrating the crucial role of NCOA4-mediated ferritinophagy in GLY-inhibited testosterone synthesis. In summary, this study provides solid evidence that NCOA4-mediated ferritinophagy promotes ferroptosis to inhibit testosterone synthesis, highlighting that targeting NCOA4 may be a potential therapeutic approach in GLY-induced male reproductive toxicity.