Human lung microvascular endothelial cell protein modification by 2-chlorohexadecanoic acid: RhoA mediates 2-chlorohexadecanoic acid-elicited endothelial activation.

Summary

Using clickable 2-ClHA probes in HLMVECs, the study identified 11 proteins uniquely modified by 2-ClHA, with RhoA emerging as a central node. Pharmacologic inhibition of RhoA blocked 2-ClHA-induced endothelial barrier dysfunction and Ang-2 release, and 2-ClHA increased RhoA activity while saturated HA had no effect. These findings implicate a specific 2-ClHA–RhoA axis in endothelial activation relevant to sepsis-associated ARDS.

Key Findings

• Identified 11 proteins uniquely modified by 2-chlorohexadecanoic acid in HLMVECs; RhoA was specifically modified by 2-ClHA but not by HA.
• RhoA inhibitors (Rhosin, C3) blocked 2-ClHA-induced endothelial barrier dysfunction and Ang-2 release.
• 2-ClHA increased RhoA activity, whereas saturated hexadecanoic acid did not activate RhoA or disrupt barrier function.

Clinical Implications

Targeting RhoA signaling or upstream chlorolipid formation may mitigate endothelial injury and Ang-2-driven vascular leak in sepsis-induced ARDS; 2-ClHA could serve as a biomarker of endothelial activation.

Limitations

• In vitro endothelial model without in vivo confirmation in sepsis models
• Causal linkage to clinical outcomes is inferred from prior associations of 2-ClHA with ARDS mortality

Future Directions

Validate the 2-ClHA–RhoA axis in animal sepsis/ARDS models and assess RhoA pathway inhibitors; longitudinally measure 2-ClHA and endothelial injury markers in patients.