Cadmium induced ferroptosis of TM4 cells through PERK-ATF4-CHOP signaling pathway

Cadmium is a highly toxic heavy metal that damages multiple organ systems. However, the effects of cadmium on male reproductive function remain incompletely understood. The present work established a cadmium-exposed model of mouse testicular Sertoli cells (TM4 cells) to explore the effect of cadmium on ferroptosis in these cells and the underlying mechanisms involved. The experimental results showed that with increasing toxicant exposure, cell viability, intracellular glutathione (GSH) content, mitochondrial membrane potential, as well as Solute Carrier Family 7 Member 11 (SLC7A11) and Glutathione Peroxidase 4 (GPX4) expression were gradually decreased. In contrast, the endoplasmic reticulum stress marker Glucose-Regulated Protein 78 and proteins involved in the PERK-ATF4-CHOP pathway were significantly upregulated. Combined treatment with the PERK inhibitor GSK2656157 markedly reduced intracellular oxidative stress, elevated GSH levels and the expression of SLC7A11, GPX4 and Nuclear factor erythroid 2-related factor 2 (Nrf2), restored mitochondrial membrane potential, and downregulated key proteins in the PERK-ATF4-CHOP pathway. Similarly, combined treatment with the ferroptosis inhibitor Ferrostatin-1 significantly ameliorated cellular redox homeostasis, increased GSH content, upregulated the expression of SLC7A11, GPX4, Nrf2 and core ferroptosis regulators, and effectively recovered mitochondrial membrane potential. Therefore, our research indicates that cadmium can induce oxidative stress in TM4 cells, thereby activating the PERK-ATF4-CHOP signaling pathway. This leads to a disruption of the cells' ability to clear oxidative stress products, causing a significant accumulation of lipid peroxidation products within the cells. As a result, TM4 cells undergo ferroptosis, causing damage to the male (masculine) reproductive system functions.