Lactobacillus salivarius alleviates inflammation via NF-κB signaling in ETEC K88-induced IPEC-J2 cells

Jiayun Qiao; Zeyang Sun; Dongmei Liang; Haihua Li

doi:10.1186/s40104-020-00488-5

Lactobacillus salivarius alleviates inflammation via NF-κB signaling in ETEC K88-induced IPEC-J2 cells

J Anim Sci Biotechnol. 2020 Aug 3:11:76. doi: 10.1186/s40104-020-00488-5. eCollection 2020.

Authors

Jiayun Qiao¹, Zeyang Sun¹, Dongmei Liang¹, Haihua Li²

Affiliations

¹ College of Life Sciences, Tianjin Key Laboratory of Animal and Plant Resistance, Tianjin Normal University, Tianjin, 300387 People's Republic of China.
² Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, 22 Jinjing Road, Tianjin, 300384 People's Republic of China.

Abstract

Background: Enterotoxigenic Escherichia coli (ETEC) K88 commonly colonize in the small intestine and keep releasing enterotoxins to impair the intestinal barrier function and trigger inflammatory reaction. Although Lactobacillus salivarius (L. salivarius) has been reported to enhance intestinal health, it remains to be seen whether there is a functional role of L. salivarius in intestinal inflammatory response in intestinal porcine epithelial cell line (IPEC-J2) when stimulated with ETEC K88. In the present study, IPEC-J2 cells were first treated with L. salivarius followed by the stimulation of ETEC K88 for distinct time period. ETEC K88 adherent status, pattern recognition receptors (PRRs) mRNA, mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) activation, the release of pro-inflammation cytokines and cell integrity were examined.

Results: Aside from an inhibited adhesion of ETEC K88 to IPEC-J2 cells, L. salivarius was capable of remarkably attenuating the expression levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), IL-8, Toll-like receptor (TLR) 4, nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain-containing protein (NLRP) 3 and NLRP6. This alternation was accompanied by a significantly decreased phosphorylation of p38 MAPK and p65 NF-κB during ETEC K88 infection with L. salivarius pretreatment. Western blot analysis revealed that L. salivarius increased the expression levels of zona occludens 1 (ZO-1) and occludin (P < 0.05) in ETEC K88-infected IPEC-J2 cells. Compared with ETEC K88-infected groups, the addition of L. salivarius as well as extra inhibitors for MAPKs and NF-κB to ETEC K88-infected IPEC-J2 cells had the capability to reduce pro-inflammatory cytokines.

Conclusions: Collectively, our results suggest that L. salivarius might reduce inflammation-related cytokines through attenuating phosphorylation of p38 MAPK and blocking the NF-κB signaling pathways. Besides, L. salivarius displayed a potency in the enhancement of IPEC-J2 cell integrity.

Keywords: ETEC K88; IPEC-J2; Inflammatory response; L. salivarius.