Exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs) can cause endothelial cell (EC) activation by inducing pro-inflammatory signaling pathways. Our previous studies indicated that linoleic acid (LA, 18:2), a major omega-6 unsaturated fatty acid in the American diet, can potentiate PCB77-mediated inflammatory responses in EC. In addition, omega-3 fatty acids (such as α-linolenic acid, ALA and 18:3) are known for their anti-inflammatory properties. We tested the hypothesis that mechanisms of PCB-induced endothelial cell activation and inflammation can be modified by different ratios of omega-6 to omega-3 fatty acids. EC were pretreated with LA, ALA, or different ratios of these fatty acids, followed by exposure to PCB77. PCB77-induced oxidative stress and activation of the oxidative stress sensitive transcription factor nuclear factor κB (NF-κB) were markedly increased in the presence of LA and diminished by increasing the relative amount of ALA to LA. Similar protective effects by increasing ALA were observed by measuring NF-κB-responsive genes, such as vascular cell adhesion molecule-1 (VCAM-1) and cyclooxygenase-2 (COX-2). COX-2 catalyzes the rate limiting step of the biosynthesis of prostaglandin E2 (PGE2). PCB77 exposure also increased PGE2 levels, which were down-regulated with relative increasing amounts of ALA to LA. The present studies suggest that NF-κB is a critical player in the regulation of PCB-induced inflammatory markers as modulated by omega-6 and omega-3 fatty acids.
|Number of pages||12|
|State||Published - Mar 10 2008|
Bibliographical noteFunding Information:
This study was supported by grants from the NIEHS/NIH (P42 ES 07380), and NIEHS Training Grant (T32 ES 07266), with additional support from the University of Kentucky Agricultural Experiment Station. Conflict of interest: none declared. The authors thank Elizabeth Oesterling and Zuzana Majkova for valuable comments and editing of the manuscript.
- Polyunsaturated fatty acid
- Vascular endothelial cell
ASJC Scopus subject areas