The Regulatory Effect of Polyunsaturated Fatty Acids on the Inflammatory Response in IPEC J-2 Cells Challenged with Enterotoxigenic E. Coli

Cameron White
Undergraduate (Animal Sciences – Nutrition)
Dr. Sheila Jacobi
Animal Sciences

The gastrointestinal (GI) tract plays a crucial role as a site for nutrient digestion and absorption in addition to serving as the largest immune organ in mammalian species. These functions are upended when the integrity of the intestinal epithelial barrier is disturbed. In the swine industry, the post-weaning period is characterized by stress-inducing situations, declining maternal antibody protection, and a shift from a liquid to solid feed diet; a trifecta that damages the gut barrier and leaves piglets susceptible to GI inflammation and infection. In fact, post-weaning enterotoxigenic Escherichia coli (ETEC) diarrhea contributes to high mortality rates on farms who must then incur all the costs associated with those losses. As antibiotic resistance remains a growing concern in animal agriculture, the discovery of alternative solutions becomes increasingly important. The objective of this research is to further evaluate the potential therapeutic role of dietary fatty acids in regulating intestinal inflammation and intestinal barrier function in pigs. The specific fatty acids examined are arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and oleate. IPEC-J2 cells from the neonatal pig were cultured in DMEM/F12 media supplemented with 5% FBS, ITS, EGF and antibiotics. Cells were plated at a density of 5x10 cells/well in a 6-well plate and grown to 100% confluence. After reaching confluence, the media including the individual fatty acids were incubated with the cells for another 96 hours and subsequently challenged with ETEC. After being challenged for 6 hours, the cells were harvested for Western Blot analysis of claudin-1 and GAPDH protein abundance. The study found that ETEC challenge reduced claudin-1 protein in IPEC-J2 cells compared to unchallenged cells (0.48 vs 0.78 ± 0.25 ration of claudin/GAPDH, respectively, P = 0.01). Within the challenged cells, DHA had a trend to protect from the loss of claudin-1 protein compared to BSA challenged cells (0.83 vs 0.39 ± 0.29 ration of claudin/GAPDH, respectively, P=0.08). In conclusion, ETEC challenge in IPEC-J2 cells reduces tight junction protein expression and DHA has a potential protective effect against claudin-1 degradation in the challenged state.