Heme drives cardiac endothelial senescence in sepsis via STING activation.

Summary

In murine sepsis, endothelial cells are the predominant senescent cardiac population, and elevated heme drives this senescence by directly activating STING. Pharmacologic STING inhibition or enhanced heme clearance via hemopexin ameliorated endothelial senescence and improved cardiac recovery.

Key Findings

• Cardiac endothelial cells are the predominant senescent population in septic hearts.
• Elevated heme levels correlate with increased endothelial senescence and impaired cardiac function.
• Heme acts as a novel ligand that promotes STING polymerization/activation, driving endothelial senescence.
• STING inhibition or increased heme clearance via hemopexin reduces endothelial senescence and improves cardiac recovery in septic mice.

Clinical Implications

Suggests that therapies enhancing heme clearance (e.g., hemopexin) or inhibiting STING could mitigate sepsis-induced cardiac dysfunction; supports biomarker exploration of heme/STING activity in septic patients.

Limitations

• Preclinical murine study; human validation is lacking.
• Translational feasibility and dosing strategies for STING inhibitors or hemopexin in sepsis remain to be established.

Future Directions

Validate heme–STING activation and endothelial senescence signatures in human sepsis cohorts; test pharmacologic STING inhibitors and heme-scavenging strategies in large-animal models and early-phase clinical trials.