RIPK1 Drives JAK1-STAT3 Signaling to Promote CXCL1-Mediated Neutrophil Recruitment in Sepsis-Induced Lung Injury.

Summary

This mechanistic study shows that RIPK1 activation in type II alveolar epithelial cells induces JAK1–STAT3 signaling, upregulates CXCL1, and drives neutrophil recruitment in sepsis-induced lung injury. Genetic and pharmacologic RIPK1 inhibition (including Compound 62) reduced inflammation and lung damage and improved survival in septic mice.

Key Findings

• RIPK1 activation occurs selectively in type II alveolar epithelial cells during sepsis.
• RIPK1 engages JAK1 to phosphorylate STAT3, promoting STAT3 binding to the Cxcl1 promoter and upregulating CXCL1.
• Genetic or pharmacologic RIPK1 inhibition reduced CXCL1, neutrophil infiltration, alveolar damage, and improved survival in septic mice.
• Compound 62, a selective RIPK1 inhibitor, attenuated systemic inflammation and preserved epithelial barrier integrity.

Clinical Implications

While preclinical, RIPK1 inhibitors could be explored to limit neutrophil-driven lung injury in sepsis, and the findings reframe alveolar epithelium as an active inflammatory driver. This supports translational trials with pharmacodynamic biomarkers (CXCL1, STAT3 activation).

Limitations

• Preclinical murine models; human validation of epithelial RIPK1 activation and pharmacodynamics is needed.
• Potential off-target or systemic effects of RIPK1 inhibition require safety profiling.

Future Directions

Translate findings to early-phase clinical trials of selective RIPK1 inhibitors in sepsis-induced lung injury with biomarker-guided patient selection; validate epithelial cell–specific signaling and CXCL1 dynamics in human biospecimens.