Polyunsaturated Fatty Acid (PUFA) Composition of Growth Medium Changes the Atherogenic Potential of Human Aortic Endothelial Cells (HAECs) Following Endotoxin Stimulation

TL;DR

This study shows that adding certain fatty acids to the growth medium of human aortic cells reduces inflammation and oxidative stress caused by endotoxins.

Contribution

The study reveals molecule-specific effects of PUFAs on endothelial inflammation, emphasizing the importance of PUFA type and context.

Findings

DHA and ALA significantly reduced ROS production and adhesion molecule expression in HAECs.

PUFAs reduced pro-inflammatory cytokines like IFNγ, TNFα, and IL-6 in LPS-stimulated HAECs.

EPA showed antioxidant effects mainly at higher LPS concentrations, while ALA increased IL-1α and endoglin.

Abstract

Background/Objectives: Endothelial activation by lipopolysaccharides (LPS) contributes to inflammation and the development of cardiovascular disease, making n-3 polyunsaturated fatty acids (PUFAs) potential modulators capable of mitigating endothelial dysfunction. The current study examines the effects of long-chain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), along with their precursor, α-linolenic acid (ALA), on oxidative stress, adhesion molecule expression, and cytokine milieu in LPS-stimulated human aortic endothelial cells (HAECs). Methods: HAECs (fifth passage) were cultured in control medium under standard conditions: ~37 °C, 5% CO2, ≥80% humidity. Cells were incubated in control basal cell medium or medium supplemented with ALA, EPA, DHA, and their combination (50 µM; n = 5 per group). After 48 h, cells were treated overnight (~16 h) with LPS from E. coli (0.75 and 1 µg/mL). HAECs and supernatants were collected for flow cytometry, Luminex, and ELISA assays. Significance was assessed using two-way analysis of variance ANOVA, followed by post hoc analyses (p < 0.05). Spearman’s correlation analysis was performed between markers, and p-values were adjusted using the Benjamini–Hochberg (BH) correction. Results: PUFA supplementation, particularly with DHA and ALA, significantly reduced intracellular reactive oxygen species (ROS) production and the expression of adhesion molecules (ICAM-1, E-selectin) in HAECs under both basal and LPS-stimulated inflammatory conditions. All PUFAs reduced pro-inflammatory cytokine levels (IFNγ, TNFα, IL-6), while ALA increased IL-1α and endoglin expression, indicating differential immunomodulatory effects. EPA exhibited antioxidant and anti-inflammatory effects primarily at higher LPS concentrations. Correlation analysis demonstrated strong interdependence between oxidative stress, inflammatory markers, and vascular activation, further confirming PUFA-mediated endothelial protection. Conclusions: PUFA supplementation produced molecule-specific effects on endothelial inflammation. DHA and ALA consistently showed anti-inflammatory and antioxidative effects, while EPA’s beneficial effect was more pronounced under inflammatory conditions, emphasising the importance of PUFA type and context in managing vascular inflammation.

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