Upregulated Hmox1 promotes cardiac ferroptosis in mice with sickle cell disease. (A-B) HbAS and HbSS mice were injected with human Hx (4 mg/kg) once a week for 4 weeks. (A) Lipid peroxidation was assessed as levels of malondialdehyde (MDA) by ELISA. (B) Relative mRNA expression of ferroptotic markers was determined using qPCR and normalized to β-actin. (C-E) HbAS and HbSS mice were injected with ferroptosis inhibitors (ferrostatin-1 [Fer-1; 1 mg/kg] or deferoxamine [DFO; 100 mg/kg]) or ferroptosis inducer (erastin; 20 mg/kg) intraperitoneally 3 times per week for 4 weeks. (C) Lipid peroxidation was assessed as levels of MDA. Relative expression of (D) ferroptotic and (E) hypertrophic markers were determined using qPCR and normalized to β-actin. (F-G) HbAS and HbSS mice were injected with hemin (25 mg/kg) or SnPP (12 mg/kg) intraperitoneally 3 times per week for 4 weeks. (F) Lipid peroxidation was assessed as MDA levels. (G) Ferroptotic markers were determined by qPCR and normalized to β-actin. Results are representative of n = 7-8 per group. Data are expressed as mean ± standard error of the mean. Statistical significance was assessed using 1-way ANOVA followed by Tukey HSD post hoc test. *P < .05 vs HbAS mice of the same treatment. ^#P < .05 vs vehicle-treated mice of the same genotype.