HIPK2 Confers Protection Against Septic Myocardial Injury by Regulating Ferroptosis

Sepsis causes systemic organ and tissue dysfunction, among which myocardial injury has become an urgent clinical problem. Homeodomain-interacting protein kinase 2 (HIPK2) is a serine-threonine kinase that plays an important role in cellular activities. In this study, we investigated the regulatory role of HIPK2 regarding the level of ferroptosis in septic myocardial injury. Trends in ferroptosis and HIPK2 expression were observed over time in a mouse model of sepsis in which cecum ligation perforation was performed. Lipopolysaccharide (LPS)-treated H9c2 cells were used to establish the experimental model, and both HIPK2 overexpression and HIPK2 knockdown H9c2 cells were used to measure the levels of inflammatory markers and ferroptosis-associated proteins. The experimental data revealed that the model mice exhibited greater degrees of myocardial injury, cardiac dysfunction, and ferroptosis compared with normal sham-operated mice, and these effects progressively worsened with increasing duration of sepsis. HIPK2 expression progressively decreased with a prolonged duration of sepsis. Compared with the control H9c2 cells, the LPS-treated H9c2 cells exhibited decreased cell viability and increased cytotoxicity, ferroptosis, and inflammatory responses. HIPK2 overexpression downregulated the levels of inflammatory and ferroptosis mediators, whereas HIPK2 knockdown demonstrated the opposite effects. HIPK2 may play a protective role against septic myocardial injury by modulating ferroptosis.