Effect of short-chain fatty acids on the expression of genes involved in short-chain fatty acid transporters and inflammatory response in goat jejunum epithelial cells

Abstract

Short-chain fatty acids (SCFAs) produced by microbial fermentation of dietary fibers are utilized by intestinal epithelial cells to provide an energy source for the ruminant. Although the regulation of mRNA expression and inflammatory response involved in SCFAs is established in other animals and tissues, the underlying mechanisms of the inflammatory response by SCFAs in goat jejunum epithelial cells (GJECs) have not been understood. Therefore, the objective of the study is to investigate the underlying mechanisms of the effects of SCFAs on SCFA transporters and inflammatory response in GJECs. These results showed that the acetate, butyrate, and SCFA concentration were markedly reduced in GJECs (p < 0.01). In addition, the propionate concentration was significantly decreased in GJECs (p < 0.05). The mRNA abundance of monocarboxylate transporter 1 (MCT1), MCT4, NHE1, and putative anion transporter 1 (PAT1) was elevated (p < 0.05) by 20 mM SCFAs at pH 7.4 compared with exposure to the pH group. The anion exchanger 2 (AE2) was increased (p < 0.05) by 20 mM SCFAs at pH 6.2. The mRNA abundance of vH⁺ ATPase B subunit (vH⁺ ATPase) was attenuated by SCFAs. For inflammatory responses, IL-1β and TNF-α were increased with SCFAs (p < 0.05). In addition, IκBα involved in NF-κB signaling pathways was disrupted by SCFAs. Consistently, p-p65 signaling molecule was enhanced by adding SCFAs. However, IL-6 was attenuated by adding SCFAs (p < 0.05). Furthermore, p-ErK1/2 mitogen-activated protein kinase (MAPK) signaling pathway was downregulated by adding SCFAs. In conclusion, these novel findings demonstrated that mRNA abundance involved in SCFA absorption is probably associated to SCFAs and pH value, and mechanism of the inflammatory response by SCFAs may be involved in NF-κB and p-ErK1/2 MAPK signaling pathways in GJECs. These pathways may mediate protective inflammation response in GJECs.

Keywords: Goat intestinal epithelial cells; Inflammatory response; SCFAs.