Potential Involvement of Ferroptosis in Duchenne Muscular Dystrophy-Associated Cardiomyopathy

<b>Background/Objectives:</b> Cardiomyopathy (CM) is a leading cause of morbidity and mortality in Duchenne muscular dystrophy (DMD) patients. Ferroptosis, an iron-dependent form of cell death characterized by lipid peroxidation, is implicated in various cardiovascular diseases. However, the role of ferroptosis in DMD-CM remains unexplored. <b>Methods:</b> Here, we used dystrophin and utrophin double-knockout (<i>mdx:utr^-/-</i>) mice as a model that exhibits cardiac pathological phenotypes similar to those seen in DMD patients to investigate the potential role of ferroptosis. <b>Results:</b> We observed an increased level of iron deposition and lipid peroxidation in the hearts of <i>mdx:utr^-/-</i> mice. Live/Dead viability assays revealed that <i>mdx:utr^-/-</i> cardiomyocytes exhibited greater susceptibility to ferroptosis than WT cardiomyocytes both at baseline and upon exposure to ferroptosis inducers. We also used <i>mdx:utr^-/-</i> mice with a heterozygous sarcolipin (SLN) knockout background (<i>sln^+/-</i>) to investigate the effect of SLN reduction on ferroptosis susceptibility in DMD-CM. Notably, ferroptosis was significantly suppressed in cardiomyocytes from <i>mdx:utr^-/-:sln^+/-</i> mice (<i>p</i> < 0.01). Western blot analysis confirmed the upregulation of transferrin receptor 1 (TfR1) and 15-lipoxygenase-1 (15LOX1), along with the downregulation of heme oxygenase-1 (HMOX-1) and ferroptosis suppressor protein 1 (FSP1) in <i>mdx:utr^-/-</i> hearts, while glutathione peroxidase 4 (GPX4) levels remained unchanged. A similar pattern of alterations in ferroptosis-related biomarkers was observed in human heart samples from DMD patients compared to healthy controls. <b>Conclusions:</b> Our results provide direct evidence that ferroptosis contributes to the pathology of DMD-CM and suggest that reducing SLN expression and inhibiting ferroptosis may represent potential therapeutic strategies for this condition.