Hydrogen protects against autoimmune myocarditis by inhibiting necroptosis via the TNF/TNFR1 signalling pathway

Autoimmune myocarditis refers to the inflammation of myocardial tissue caused by innate and adaptive immune responses, characterized by elevated levels of tumour necrosis factor-α (TNF-α), a classic pro-inflammatory factor. Although hydrogen exhibits anti-inflammatory and antioxidant properties, its therapeutic effects in autoimmune myocarditis have not been evaluated. Therefore, the present study aimed to explore whether hydrogen can alleviate autoimmune myocarditis via TNF-α. An experimental autoimmune myocarditis (EAM) model was established in BALB/c mice via subcutaneous injection of pig-derived myocardial myoglobin emulsified with complete Freund's adjuvant. The treatment group received 2 % hydrogen inhalation twice a day (3 h each time) for 21 days. CD4+ T cell expression was higher in the EAM group than in the Control group, and this increase was attenuated following treatment with hydrogen. Additionally, the levels of TNF-α and related inflammatory factors were substantially higher in the EAM group than in the Control group, and these changes were reversed following hydrogen treatment. Echocardiography assessments demonstrated a significant improvement in heart function following treatment with hydrogen compared to that in the EAM group. Pathological results revealed significant inflammatory cell infiltration and fibrosis in the hearts of the untreated EAM group. Tissue immunofluorescence and protein immunoblotting indicated elevated necroptosis markers in the EAM group, which were downregulated after treatment with hydrogen. This study demonstrates that hydrogen effectively ameliorated autoimmune myocarditis by modulating necroptosis via the TNF/TNFR1 signalling pathway, making it a promising novel therapeutic strategy for myocarditis.