WWP2 Protects Against Sepsis-induced Cardiac Injury Through Inhibiting Cardiomyocyte Ferroptosis

Background And Objectives: Cardiac injury plays a critical role in contributing to the mortality associated with sepsis, a condition marked by various forms of programmed cell deaths. Previous studies hinted at the WW domain-containing E3 ubiquitin protein ligase 2 (WWP2) involving in heart failure and endothelial injury. However, the precise implications of WWP2 in sepsis-induced cardiac injury, along with the underlying mechanisms, remain enigmatic.

Methods: Sepsis induced cardiac injury were constructed by intraperitoneal injection of lipopolysaccharide. To discover the function of WWP2 during this process, we designed and performed loss/gain-of-function studies with cardiac-specific vectors and WWP2 knockout mice. Combination experiments were performed to investigate the relationship between WWP2 and downstream signaling in septic myocardium injury.

Results: The protein level of WWP2 was downregulated in cardiomyocytes during sepsis. Cardiac-specific overexpression of WWP2 protected heart from sepsis induced mitochondrial oxidative stress, programmed cell death and cardiac injury, while knockdown or knockout of WWP2 exacerbated this process. The protective potency of WWP2 was predominantly linked to its ability to suppress cardiomyocyte ferroptosis rather than apoptosis. Mechanistically, our study revealed a direct interaction between WWP2 and acyl-CoA synthetase long-chain family member 4 (FACL4), through which WWP2 facilitated the ubiquitin-dependent degradation of FACL4. Notably, we observed a notable reduction in ferroptosis and cardiac injury within WWP2 knockout mice after FACL4 knockdown during sepsis.

Conclusions: WWP2 assumes a critical role in safeguarding the heart against injury induced by sepsis via regulating FACL4 to inhibit LPS-induced cardiomyocytes ferroptosis.