2-Chlorofatty Aldehyde Elicits Endothelial Cell Activation.

Area of Science:

• Cardiovascular Biology
• Inflammation Research
• Endothelial Cell Biology

Background:

• Endothelial activation and dysfunction are key features of inflammation.
• Neutrophil-vascular interactions significantly impact vascular health and disease.
• Myeloperoxidase (MPO)-derived products, including 2-Chlorofatty aldehyde (2-ClFALD), contribute to endothelial dysfunction.

Purpose of the Study:

• To investigate the role of 2-ClFALD in endothelial dysfunction.
• To compare the effects of 2-ClFALD on different human endothelial cell types: coronary artery (HCAEC), lung microvascular (HLMVEC), and kidney (HKEC).

Main Methods:

• Treatment of HCAEC, HLMVEC, and HKEC with 2-ClFALD.
• Assessment of surface expression of adhesion molecules (selectins, ICAM-1, VCAM-1).
• Measurement of neutrophil and platelet adherence.
• Evaluation of endothelial barrier function.
• Localization studies using a synthetic alkyne analog of 2-ClFALD.

Main Results:

• 2-ClFALD significantly increased selectin, ICAM-1, and VCAM-1 expression in HCAEC and HLMVEC, leading to robust neutrophil and platelet adherence.
• In contrast, 2-ClFALD-treated HKEC showed reduced adherence molecule expression but increased neutrophil adherence, with no significant platelet adherence.
• All three endothelial cell types exhibited a time-dependent loss of barrier function upon 2-ClFALD treatment.
• Studies with a synthetic analog indicated 2-ClHDyA localization to the ER and Golgi in HCAEC and HLMVEC.

Conclusions:

• 2-ClFALDs induce endothelial cell dysfunction.
• The degree of endothelial cell responsiveness to 2-ClFALD varies depending on the vascular bed.
• These findings highlight the differential impact of MPO-derived products on vascular endothelial cells.