Hepatic Nuclear Factor Erythroid 2 Related Factor 1 Activity Promotes Host Defense in Endotoxemia and Bacterial Sepsis.

Summary

Hepatic Nrf1, but not Nrf2, is essential for survival in endotoxemia and bacterial sepsis by sustaining VLDL secretion and triglyceride handling. Pharmacologic inhibition of VLDL secretion or hydrolysis abrogated protection, whereas lipid infusion rescued, highlighting a liver-centered metabolic defense program.

Key Findings

• Hepatic Nrf1 activity decreases in endotoxemia and sepsis; hepatocyte Nrf1 deficiency induces severe hypothermia and mortality, unlike Nrf2.
• Genetic activation of hepatic Nrf1 improves survival and mitigates hypothermia.
• Nrf1 controls VLDL secretion and triglyceride metabolism; deficiency reduces and activation enhances VLDL release.
• Lomitapide or poloxamer 407 blunted Nrf1-mediated protection, whereas intralipid infusion rescued survival.

Clinical Implications

Augmenting hepatic Nrf1 activity or leveraging lipid delivery (e.g., tailored lipid emulsions) could be explored as adjunctive strategies to prevent hypothermia and improve survival in sepsis, pending human validation and safety profiling.

Limitations

• Preclinical murine models; human translational data are lacking.
• Specific, clinically viable Nrf1 activators are not yet established; lipid-based rescue may carry metabolic risks.

Future Directions

Develop and test selective Nrf1 modulators; evaluate lipid support strategies; assess Nrf1 activity and lipid flux markers in human sepsis cohorts.