Potential Involvement of Ferroptosis in Duchenne Muscular Dystrophy-Associated Cardiomyopathy.

Background/Objectives: 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. Methods: Here, we used dystrophin and utrophin double-knockout (mdx:utr(-/-)) mice as a model that exhibits cardiac pathological phenotypes similar to those seen in DMD patients to investigate the potential role of ferroptosis. Results: We observed an increased level of iron deposition and lipid peroxidation in the hearts of mdx:utr(-/-) mice. Live/Dead viability assays revealed that mdx:utr(-/-) cardiomyocytes exhibited greater susceptibility to ferroptosis than WT cardiomyocytes both at baseline and upon exposure to ferroptosis inducers. We also used mdx:utr(-/-) mice with a heterozygous sarcolipin (SLN) knockout background (sln(+/-)) to investigate the effect of SLN reduction on ferroptosis susceptibility in DMD-CM. Notably, ferroptosis was significantly suppressed in cardiomyocytes from mdx:utr(-/-):sln(+/-) mice (p < 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 mdx:utr(-/-) 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. Conclusions: 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.