Characterization of the inflammatory response of a canine intestinal epithelial cell line challenged with lipopolysaccharides and/or butyrate.

Cell culture models are used to assess the impacts that dietary changes have on host health; however, there is limited knowledge about canine intestinal cell models compared to those for humans. The objective of this study was to use a canine intestinal epithelial cell (cIEC) line to investigate responses to pro- and anti-inflammatory treatments relevant to health in the dog. It was anticipated that lipopolysaccharides (LPS) would cause a pro-inflammatory response, while butyrate would cause an anti-inflammatory response and mitigate the pro-inflammatory response induced by LPS. cIEC were stimulated with 250 µg/mL of LPS, 1 mM of butyrate, or a combination of LPS and butyrate compared to untreated controls over 8 h (n = 6 per treatment group). LPS treatment significantly reduced transepithelial electrical resistance (TEER) over time and caused increases in the protein abundance and gene expression of the pro-inflammatory interleukin (IL)-8 and chemokine (C-C motif) ligand (CCL)2 compared to untreated controls. Additionally, LPS treatment caused increases in the gene expression of the pro-inflammatory interferon gamma-induced protein (IP)-10, and increased protein abundances of keratinocyte chemotactic (KC)-like in apical and basal cell media compared to untreated cIEC. Butyrate failed to elicit an increase in anti-inflammatory cytokines, although treatment significantly reduced protein expression of the pro-inflammatory CCL2 in apical cell culture media and increased protein expression of IP-10. Butyrate reduced the LPS-induced IL-8 and KC-like increased pro-inflammatory protein abundances in basal cell culture media compared to untreated canine IEC and was found to reduce the LPS-induced intestinal barrier hyperpermeability. However, butyrate and LPS in combination caused an increase in CCL2 gene expression compared to treatment with butyrate and LPS alone. Therefore, this study has shown that butyrate can mitigate some aspects of the LPS-induced inflammatory response in an in vitro model of the canine intestine. Overall, changes in intestinal barrier integrity in response to the treatment were similar to that reported for human cell models; however, the molecular signaling somewhat differed, highlighting the need for further studies and illustrating the value of studying a canine cell model to understand the molecular responses in the dog.