Abstract
Background
Cisplatin causes oxidative and iron-dependent injury, but whether it induces ferroptosis-associated damage in retinal pigment epithelial cells and how Toxoplasma gondii (T. gondii) can modify this response remain unclear.Objective
This study investigated cisplatin-induced oxidative stress, apoptosis, ferroptosis-associated changes, and iron dysregulation in ARPE-19 cells and evaluated the effects of acute T. gondii infection.Methods
ARPE-19 cells were exposed to increasing concentrations of cisplatin for 24 h. Cell viability, oxidative stress, antioxidant capacity, apoptosis-related proteins, ferroptosis-defense molecules, and intracellular iron were assessed using biochemical assays, fluorescence staining, reverse-transcription polymerase chain reaction, and western blotting. Cells treated with 20 μM cisplatin were additionally infected with T. gondii at a multiplicity of infection of 5 or treated with ferrostatin-1, deferoxamine, or Z-VAD-FMK.Results
Cisplatin reduced cell viability in a concentration-dependent manner, with a half-maximal inhibitory concentration of 20.37 μM, and increased reactive oxygen species, malondialdehyde, cleaved caspase-3, and Bax while decreasing superoxide dismutase, glutathione, and Bcl-xL. It also reduced GPX4 and SLC7A11 protein expression and FSP1 mRNA levels, while increasing FTH1 and SLC11A2 protein expression and intracellular Fe2+ and total iron. T. gondii infection improved viability, reduced oxidative stress and cleaved caspase-3, restored antioxidant capacity and GPX4/SLC7A11 expression, and limited iron accumulation. Ferrostatin-1 and deferoxamine did not markedly suppress apoptotic proteins, whereas Z-VAD-FMK inhibited apoptotic signaling without restoring GPX4 or SLC7A11.Conclusions
Cisplatin induces concurrent oxidative stress, apoptosis, impairment of ferroptotic defense, and iron accumulation in ARPE-19 cells. Acute T. gondii infection attenuates these alterations by preserving redox balance, ferroptosis-defense pathways, and iron homeostasis.