Ferroptosis-Induced Metabolic Shifts in Cardiac Cells: Exploring the Influence of Glutaminolysis

Aims: Ferroptosis, an iron-dependent non-apoptotic cell death mechanism, profoundly impacts cellular metabolism. Despite its significance, a comprehensive metabolomic analysis of ferroptotic cells remains elusive.

Study Design and Methodology: In this study, we investigated the metabolome of H9c2 cardioblast cells using gas chromatography-mass spectrometry during ferroptosis induced by RSL3, an inhibitor of glutathione peroxidase 4. Notably, we explored the effects of ferroptosis inhibitors, including ferrostatin-1, and the mitochondrial-targeted ROS scavenger, XJB-5-131.

Place and Duration of Study: Department of Physiology and Department of Biochemistry, University of Puerto Rico School of Medicine, between October 2019 and September 2021.

Results: The results revealed a significant reduction of amino acids crucial for glutathione synthesis by more than two-fold upon RSL3 treatment. Conversely, saturated fatty acid levels were notably elevated in RSL3-exposed cells, with no discernible impact on unsaturated fatty acids. Moreover, RSL3 induced substantial alterations in mitochondrial tricarboxylic acid cycle intermediates; while isocitrate and 2-oxoglutarate levels increased, succinate levels decreased significantly in RSL3-treated cells. Importantly, ferrostatin-1 and XJB-5-131 effectively prevented RSL3-induced cell death and preserved the metabolic profile. Given the involvement of 2-oxoglutarate in ferroptosis regulation, particularly through glutamine metabolism, we further investigated the role of glutaminolysis in H9c2 cardi-oblasts ferroptosis. Silencing of glutaminase 1, encoding the K-type mitochondrial glutaminase (glutaminase C), conferred protection against ferroptosis at the early stage.

Conclusion: In conclusion, our study demonstrates the disruptive impact of RSL3-induced ferroptosis on the metabolome of H9c2 cardioblasts.