EETs alleviate ox-LDL-induced inflammation by inhibiting LOX-1 receptor expression in rat pulmonary arterial endothelial cells.

Abstract

Oxidized low-density lipoprotein (Ox-LDL) is associated with atherosclerotic events through the modulation of arachidonic acid (AA) metabolism and activation of inflammatory signaling. Cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) mitigate inflammation through nuclear factor-κB (NF-κB). In this study, we explored the effects and mechanisms of exogenous EETs on the ox-LDL-induced inflammation of pulmonary artery endothelial cells (PAECs), which were cultured from rat pulmonary arteries. We determined that pre-treatment with 11,12-EET or 14,15-EET attenuated the ox-LDL-induced expression and release of intercellular adhesion molecule-1 (ICAM-1), E-selectin, and monocyte chemoattractant protein-1 (MCP-1) in a concentration-dependent manner. In addition, the ox-LDL-induced expression of CYP2J4 was upregulated by 11,12-EET and 14,15-EET (1μM). Furthermore, the endothelial receptor of lectin-like oxidized low-density lipoprotein (LOX-1) was downregulated in PAECs treated with EETs. The inflammatory responses evoked by ox-LDL (100μg/mL) were blocked by pharmacological inhibitors of Erk1/2 mitogen-activated protein kinase (MAPK) (U0126), p38 MAPK (SB203580), and NF-κB (PDTC). In addition, we confirmed that 11,12-EET suppresses phosphorylation of p38, degradation of IκBα, and activation of NF-κB (p65), whereas 14,15-EET can significantly suppress the phosphorylation of p38 and Erk1/2. Our results indicate that EETs exert beneficial effects on ox-LDL-induced inflammation primarily through the inhibition of LOX-1 receptor upregulation, MAPK phosphorylation, and NF-κB activation and through the upregulation of CYP2J4 expression. This study helps focus the current understanding of the contribution of EETs to the regulation of the inflammation of pulmonary vascular endothelial cells. Furthermore, the therapeutic potential of targeting the EET pathway in pulmonary vascular disease will be highlighted.

• Authors: Jun-xia Jiang, Shui-juan Zhang, Ya-nan Liu, Xi-xi Lin, Yan-hong Sun, Hui-juan Shen, Xiao-feng Yan, Qiang-min Xie
• Journal: European journal of pharmacology (Eur J Pharmacol) Vol. 727 Pg. 43-51 (Mar 15 2014) ISSN: 1879-0712 [Electronic] Netherlands
• PMID: 24486707 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical References

• Anti-Inflammatory Agents
• Inflammation Mediators
• Lipoproteins, LDL
• NF-kappa B
• OLR1 protein, rat
• RNA, Messenger
• Scavenger Receptors, Class E
• oxidized low density lipoprotein
• 11,12-epoxy-5,8,14-eicosatrienoic acid
• 14,15-epoxy-5,8,11-eicosatrienoic acid
• Cytochrome P-450 Enzyme System
• Cyp2j4 protein, rat
• Cytochrome P450 Family 2
• Mitogen-Activated Protein Kinases
• 8,11,14-Eicosatrienoic Acid

Topics

• 8,11,14-Eicosatrienoic Acid (analogs & derivatives, pharmacology)
• Animals
• Anti-Inflammatory Agents (pharmacology)
• Cells, Cultured
• Cytochrome P-450 Enzyme System (metabolism)
• Cytochrome P450 Family 2
• Dose-Response Relationship, Drug
• Endothelial Cells (drug effects, metabolism)
• Enzyme Activation
• Inflammation (genetics, metabolism, prevention & control)
• Inflammation Mediators (metabolism)
• Lipoproteins, LDL (metabolism)
• Male
• Mitogen-Activated Protein Kinases (metabolism)
• NF-kappa B (metabolism)
• Phosphorylation
• Pulmonary Artery (drug effects, metabolism)
• RNA, Messenger (metabolism)
• Rats, Sprague-Dawley
• Scavenger Receptors, Class E (drug effects, metabolism)
• Signal Transduction (drug effects)