OTUD1 Relieves Coxsackievirus-Induced Ferroptosis and Inflammation in Myocardial Cells by Stabilizing NRF2 and Inhibiting NF-κB Signaling.

CVB3 infection caused myocardial injury with increased injury markers and inflammatory cytokines in vivo and in vitro.

• CVB3 infection increased levels of myocardial injury markers CK-MB and cTnI in mouse heart tissue
• Inflammatory cytokines IL-1β, IL-6, and TNF-α levels were elevated following CVB3 infection
• H9c2 cell viability decreased after CVB3 infection as measured by CCK-8 assay
• Heart tissue damage was evaluated by HE staining in the in vivo mouse model

CVB3 infection induced ferroptosis-associated changes in myocardial cells, including increased oxidative stress markers and decreased antioxidant defense.

• Levels of Fe2+, MDA, and ROS increased following CVB3 infection
• SOD levels decreased after CVB3 infection
• Expression of ferroptosis-related proteins GPX4 and SLC7A11 decreased after CVB3 infection
• These ferroptosis indicators were assessed using assay kits and western blotting

CVB3 infection suppressed OTUD1 expression in both mouse heart tissues and H9c2 cells.

• OTUD1 expression was repressed in mouse heart tissues after CVB3 infection
• OTUD1 expression was also repressed in H9c2 cells after CVB3 infection
• Expression was detected by western blotting, immunohistochemistry, and immunofluorescence
• This downregulation of OTUD1 occurred in both the in vivo and in vitro CVB3 myocarditis models

Overexpression of OTUD1 partially attenuated CVB3-induced myocardial ferroptosis and inflammation.

• OTUD1 overexpression partially reversed the CVB3-induced increases in IL-1β, IL-6, and TNF-α
• OTUD1 overexpression partially reversed increases in Fe2+, MDA, and ROS caused by CVB3
• OTUD1 overexpression partially restored SOD levels and GPX4 and SLC7A11 expression reduced by CVB3
• OTUD1 overexpression partially attenuated increases in CK-MB and cTnI and decreases in H9c2 cell viability induced by CVB3

CVB3 infection suppressed NRF2 expression and promoted NF-κB signaling activation in vivo and in vitro.

• NRF2 expression was repressed by CVB3 infection in both mouse heart tissues and H9c2 cells
• CVB3 infection promoted the activation of NF-κB signaling in vivo and in vitro
• These findings were detected by western blotting, immunohistochemistry, and immunofluorescence

OTUD1 relieves CVB3-induced inflammation and ferroptosis through a mechanism involving stabilization of NRF2 and inhibition of NF-κB signaling.

• Mechanistic study revealed OTUD1 stabilizes NRF2 expression in the context of CVB3 infection
• OTUD1 inhibits NF-κB signaling activation induced by CVB3
• OTUD1 is a deubiquitinase, suggesting its stabilization of NRF2 may involve deubiquitination
• Both NRF2 stabilization and NF-κB inhibition contribute to OTUD1's protective effects against ferroptosis and inflammation