The present study evaluated the mechanism underlying the protective effect of sulforaphane (SFN) on cadmium (Cd)-induced Sertoli cell (TM4 cells) injury in mice. The apoptosis rate of cells in each group was detected by flow cytometry. It was determined the effect of SFN on the expression of downstream molecular targets of Nrf2/ARE axis and on the lipid peroxide content. The related genes involved in the nuclear factor E2-related factor 2(Nrf2)/antioxidant response element (ARE) signaling pathway were evaluated by RT-PCR; for example, the mRNA expression levels of Nrf2, heme oxygenase-1 (HO-1), glutathione peroxidase (GSH-Px), quinone oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase (γ-GCS), while the protein expression levels were assessed by Western blot. Our results showed that the mRNA and protein expression levels of Nrf2, HO-1, NQO1, GSH-Px, and γ-GCS were increased in various degree when the Sertoli cells were to added different concentrations of SFN. Our results also showed that SFN reduced the apoptosis rate, increased the activity of T-SOD, inhibited the increase of the MDA content caused by Cd. Meanwhile, SFN could increase the mRNA and protein expression levels of Nrf2, HO-1 and NQO1 and reduced the mRNA and protein expression levels of GSH-Px and γ-GCS caused by Cd in Sertoli cells (p < 0.01). Taken together, SFN could improve the antioxidant capacity of Sertoli cells, and exert a protective effect on the oxidative damage and apoptosis of Cd-induced Sertoli cells through the activation of Nrf2/ARE signal transduction pathway.
Keywords: Cd; Nrf2/ARE signaling pathway; TM4 cell; apoptosis; oxidative damage; sulforaphane.