Clostridium Tyrobutyricum Protect Intestinal Barrier Function from LPS-Induced Apoptosis via P38/JNK Signaling Pathway in IPEC-J2 Cells.

BACKGROUND/AIMS: The intestinal mucosa forms a physical and metabolic barrier against the diffusion of pathogens, toxins, and allergens from the lumen into the circulatory system. Early weaning, a critical phase in swine production, can compromise intestinal barrier function through mucosal damage and alteration of tight junction integrity Maintenance of intestinal barrier function plays a pivotal role in optimum gastrointestinal health. In this study, we investigated the effects of Clostridium tyrobutyricum (C.t) on intestinal barrier dysfunction induced by lipopolysaccharide (LPS) and the underlying mechanisms involved in intestinal barrier protection.

METHODS: A Transwell model of IPEC-J2 cells was used to imitate the intestinal barrier. Fluorescence microscopy and flow cytometry were used to evaluate apoptosis. Real-time PCR was used to detect apoptosis-related genes and the downstream genes of the p38/c-Jun N-terminal kinase (JNK) signaling pathways. Western blotting was used to measure the expressions of tight junction proteins and mitogen-activated protein kinases.

RESULTS: C.t efficiently maintained trans-epithelium electrical resistance values and intestinal permeability after LPS-induced intestinal barrier disruption. The expressions of tight junction proteins (ZO-1, claudin-1, and occludin) were promoted when IPEC-J2 cells were treated with C.t. Fluorescence imaging and flow cytometry revealed that C.t qualitatively and quantitatively inhibited LPS-induced cell apoptosis. C.t also increased the relative expression of the anti-apoptotic gene Bcl-2 and decreased that of the apoptotic genes Bax and caspase-3/-8. Moreover, the protective effect of C.t on damaged intestinal cell models was associated with suppression of p38 and JNK phosphorylation, negative regulation of the relative expressions of downstream genes including AP-1, ATF-2, ELK-1, and p53, and activation of Stat3 expression.

CONCLUSIONS: These findings indicate that C.t may promote intestinal integrity, suggesting a novel probiotic effect on intestinal barrier function.