The effect of omega- 3 polyunsaturated fatty acids on endothelial tight junction occludin expression in rat aorta during lipopolysaccharide-induced inflammation.
OBJECTIVE
Occludin is essential for proper assembly of tight junctions (TJs) which regulate paracellular endothelial permeability. Omega-3 polyunsaturated fatty acids (Ω-3 PUFA) protect endothelial barrier function against injury.


METHODS
We examined anti-inflammatory effect of Ω-3 PUFA intake (30 mg/kg/day for 10 days) on expression and location of occludin in the aorta of adult Wistar rats after a single dose of bacterial lipopolysaccharide (LPS, Escherichia coli, 1 mg/kg). The ultrastructure of TJs after LPS administration was also investigated. We measured plasma levels of C-reactive protein (CRP), Malondialdehyde (MDA) and CD68 expression and determined the total activity of NO synthase (NOS) in the aortic tissue.


RESULTS
LPS induced a significant decrease of occludin expression accompanied by structural alterations of TJs. Levels of CRP, MDA, CD68 and NOS activity were elevated after LPS injection compared to controls indicating presence of moderate inflammation. Ω-3 PUFA supplementation did not affect occludin expression in treated inflammatory group. However they reduced CRP and MDA concentration and CD68 expression, but conversely, they increased NOS activity compared to inflammatory group.


CONCLUSIONS
Our results indicate that a single dose of LPS could have a long-term impact on occludin expression and thus contribute to endothelial barrier dysfunction. 10-day administration of Ω-3 PUFA had partial anti-inflammatory effects on health of rats without any effect on occludin expression.
Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
Jakub
J
Krizak
Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
Karel
K
Frimmel
Institute of Normal and Pathological Physiology, Slovak Academy of Sciences, Bratislava, Slovakia.
Iveta
I
Bernatova
Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Bratislava, Slovakia.
Jana
J
Navarova
Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Bratislava, Slovakia.
Ruzena
R
Sotnikova
Institute for Heart Research, Slovak Academy of Sciences, Bratislava, Slovakia.
Ludmila
L
Okruhlicova
Aorta; Endothelium; Lipopolysaccharide; Occludin; Omega-3 polyunsaturated fatty acids