Effect of eicosapentaenoic acid-derived prostaglandin E3 on intestinal epithelial barrier function

Prostaglandins (PG) are inflammatory mediators derived from arachidonic or eicosapentaenoic acid giving rise to the 2-series or the 3-series prostanoids, respectively. Previously, we have observed that PGE₂ disrupts epithelial barrier function. Considering the beneficial effect of fish oil consumption in intestinal inflammatory processes, the aim of this study was to assess the role of PGE₃ on epithelial barrier function assessed from transepithelial electrical resistance and dextran fluxes in Caco-2 cells. The results indicate that PGE₃ increased paracellular permeability (PP) to the same extent as PGE₂, through the interaction with EP₁ and EP₄ receptors and with intracellular Ca²⁺ and cAMP as the downstream targets. Moreover, we observed a redistribution of tight junction proteins, occludin and claudin-4. In conclusion, PGE₃ is able to increase PP thus leading to reconsider the role of PGE₂/PGE₃ ratio in the beneficial effects of dietary fish oil supplementation in the disruption of barrier function.