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

Summary

Using clickable 2-ClHA analogs, the authors mapped covalent protein modifications in HLMVECs and identified RhoA as a specific 2-ClHA target and hub. 2-ClHA activated RhoA, impaired barrier function, and increased Ang-2 release; RhoA inhibitors (Rhosin, C3) mitigated these effects, linking MPO-derived chlorolipids to endothelial dysfunction relevant to ARDS.

Key Findings

• 2-ClHA covalently modified 11 proteins specifically and 194 proteins in common with HA in HLMVECs.
• RhoA was a specific 2-ClHA-modified protein and network hub; 2-ClHA activated RhoA.
• Rhosin and C3 inhibited 2-ClHA-induced barrier dysfunction and Ang-2 release.
• HA did not induce barrier dysfunction, Ang-2 release, or RhoA activation, confirming pathway specificity.

Clinical Implications

Although preclinical, targeting RhoA signaling or chlorolipid formation (e.g., MPO activity modulation) may preserve endothelial integrity in sepsis-associated ARDS; Ang-2 reduction offers a measurable pharmacodynamic marker.

Limitations

• In vitro HLMVEC model without in vivo validation
• No direct testing in ARDS patient samples beyond prior associations of 2-ClHA levels

Future Directions

Validate the 2-ClHA–RhoA pathway in vivo and in patient samples; test MPO inhibition or RhoA-targeted therapies for endothelial protection in sepsis/ARDS models.