GPX4 promoter hypermethylation induced by ischemia/reperfusion injury regulates hepatocytic ferroptosis

Background and Aims

Glutathione peroxidase 4 (GPX4) is a key factor in ferroptosis, which is involved in ischemia-reperfusion injury. However, little is known about its role in hepatic ischemia-reperfusion injury (HIRI). This study aimed to investigate the role of GPX4 methylation in ferroptosis during HIRI.

Methods

For the in vivo experiments, an ischemia-reperfusion model was created by subjecting mice to simulated HIRI. Ferroptosis occurrence, GPX4 promoter methylation, and global methylation levels were then assessed.

Results

Ferroptosis was observed in oxygen and glucose deprivation, characterized by a significant decrease in cellular viability (P < 0.05), an increase in lipid peroxidation (P < 0.01), iron overload (P < 0.05), and down-regulation of GPX4 (P < 0.05). This ferroptosis was exacerbated by GPX4 knockdown (P < 0.01) and mitigated by exogenous glutathione (P < 0.01). Similarly, ferroptosis was evident in mice subjected to HIRI, with a down-regulation of GPX4 mRNA and protein expression (all P < 0.01), and an upregulation of acyl-CoA synthetase long-chain family member 4 mRNA and protein (all P < 0.01), as well as prostaglandin-endoperoxide synthase 2 mRNA and protein expression (all P < 0.05). Methylation levels increased, evidenced by upregulation of DNA methylation transferase expression (P < 0.05) and down-regulation of Ten-eleven translocation family demethylases (P < 0.01), along with an upregulation of GPX4 promoter methylation.

Conclusions

Ferroptosis may be the primary mode of cell death in hepatocytes following ischemia-reperfusion injury. The methylation of the GPX4 promoter and elevated levels of global hepatic methylation are involved in the regulation of ferroptosis.

Full text

https://www.xiahepublishing.com/2310-8819/JCTH-2024-00135

The study was recently published in the Journal of Clinical and Translational Hepatology.

The Journal of Clinical and Translational Hepatology (JCTH) is owned by the Second Affiliated Hospital of Chongqing Medical University and published by XIA & HE Publishing Inc. JCTH publishes high quality, peer reviewed studies in the translational and clinical human health sciences of liver diseases. JCTH has established high standards for publication of original research, which are characterized by a study’s novelty, quality, and ethical conduct in the scientific process as well as in the communication of the research findings. Each issue includes articles by leading authorities on topics in hepatology that are germane to the most current challenges in the field. Special features include reports on the latest advances in drug development and technology that are relevant to liver diseases. Regular features of JCTH also include editorials, correspondences and invited commentaries on rapidly progressing areas in hepatology. All articles published by JCTH, both solicited and unsolicited, must pass our rigorous peer review process.

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