Iron-overload-induced ferroptosis in mouse cerebral toxoplasmosis promotes brain injury and could be inhibited by Deferiprone.

Iron is a trace metal element that is essential for the survival of cells and parasites. The role of iron in cerebral toxoplasmosis (CT) is still unclear. Deferiprone (DFP) is the orally active iron chelator that binds iron in a molar ratio of 3:1 (ligand:iron) and promotes urinary iron excretion to remove excess iron from the body. The aims of this experiment were to observe the alterations in iron in brains with Toxoplasma gondii (T. gondii) acute infections and to investigate the mechanism of ferroptosis in CT using DFP. We established a cerebral toxoplasmosis model in vivo using TgCtwh3, the dominant strains of which are prevalent in China, and treated the mice with DFP at a dose of 75 mg/kg/d. Meanwhile, we treated the HT-22 cells with 100 μM DFP for half an hour and then infected cells with TgCtwh3 in vitro. A qRT-PCR assay of TgSAG1 levels showed a response to the T. gondii burden. We used inductively coupled plasma mass spectrometry, an iron ion assay kit, Western blot analysis, glutathione and glutathione disulfide assay kits, a malonaldehyde assay kit, and immunofluorescence to detect the ferroptosis-related indexes in the mouse hippocampus and HT-22 cells. The inflammatory factors interferon-γ, tumor necrosis factor-α, transforming growth factor-β, and arginase 1 in the hippocampus and cells were detected using the Western blot assay. Hematoxylin and eosin staining, electron microscopy, and the Morris water maze experiment were used to evaluate the brain injuries of the mice. The results showed that TgCtwh3 infection is followed by the activation of ferroptosis-related signaling pathways and hippocampal pathological damage in mice. The use of DFP led to ferroptosis resistance and attenuated pathological changes, inflammatory reactions and T. gondii burden of the mice, prolonging their survival time. The HT-22 cells with TgCtwh3 activated the ferroptosis pathway and was inhibit by DFP in vitro. In TgCtwh3-infected cells, inflammatory response and mitochondrial damage were severe, but these effects could be reduced by DFP. Our study elucidates the mechanism by which T. gondii interferes with the host's iron metabolism and activates ferroptosis, complementing the pathogenic mechanism of CT and further demonstrating the potential value of DFP for the treatment of CT. Author summary: Iron metabolism is closely linked to host's immunity and is involved in inflammatory and infectious processes. Iron is an important target for the host in its fight against pathogens. Meanwhile, iron is likewise a nutritional factor of pathogens and is closely associated to the survival and reproduction of T. gondii. The iron acquisition mechanisms of T. gondii may interfere with or disrupt host iron homeostasis and may induce ferroptosis in the host. Cerebral toxoplasmosis (CT) is a life-threatening infection caused by T. gondii. A comprehensive understanding of the iron metabolism status of hippocampal cells in the cerebral toxoplasmosis mouse model will help to understand the T. gondii iron acquisition pattern. To provide clues for subsequent studies on the specific mechanisms by which T. gondii regulates host iron metabolism and the development of relevant anti-Toxoplasma drugs. Here, our results showed that ferroptosis and inflammation appeared in the hippocampus after T. gondii infection. The DFP inhibits ferroptosis and attenuates inflammation, improving overall health and hippocampal pathological manifestations in infected mice. Our findings highlight that maintaining iron homeostasis and targeting ferroptosis may be a potential therapeutic approach for toxoplasmosis. [ABSTRACT FROM AUTHOR]

Copyright of PLoS Neglected Tropical Diseases is the property of Public Library of Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)