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

Abstract

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.

Astragalus polysaccharides alleviates LPS‐induced inflammation via the NF‐κB/MAPK signaling pathway

“…Previous studies found that LPS can induce cells apoptosis, which also promotes the production of inflammatory factors (Xiao et al, 2018). To examine the effect of APS on LPS‐stimulated IPEC‐J2 cells apoptosis, cells apoptosis and necrosis were assessed by Annexin‐V‐FITC/PI double staining.…”

“…Previous studies found that LPS can induce cells apoptosis, which also promotes the production of inflammatory factors (Xiao et al, 2018).…”

“…IECs can effectively absorb nutrients and electrolytes and act as internal and external intestinal defense barriers (Deuring, De, Kuipers, Peppelenbosch, & Cj, 2013; Xiao et al, 2018), which selectively accepts some substances; it also prevents harmful substances (such as bacteria and toxins) from entering the intestinal mucosa and moving into other tissues, organs, and blood circulation structures in humans and animals, thereby resisting foreign aggression (Luissint et al, 2016; Salvo, Alonso, Pardo, Casado, & Vicario, 2015; Turner, 2009). The porcine small IEC line (IPEC‐J2) a model of normal IECs, is isolated from jejunum epithelium of a neonatal unsuckled piglet (Liu et al, 2010).…”

Accumulation of tissue factor in endothelial cells promotes cellular apoptosis through over-activation of Src1 and involves β1-integrin signalling

“…p38 MAPK is a serine/threonine kinase that is activated by the phosphorylation of Thr180 and Tyr182 residues in response to different stress signals [25] and can promote cell apoptosis [26]. Upstream activators of p38 include Src1 [27,28] and Rac1 [29,30].…”

Porcine circovirus type 2 exploits JNK-mediated disruption of tight junctions to facilitate Streptococcus suis translocation across the tracheal epithelium

“…A previous study showed that the effector of Salmonella enteritidis AvrA could stabilize TJ protein ZO-1 and attenuate bacterial invasion via inhibition of the JNK signaling pathway [41]. The downstream genes of the JNK signaling pathway, including AP-1, c-Jun, ATF-2 and ELK-1, are reported to regulate epithelial barrier functions [41][42][43][44][45]; further study is required to determine which downstream molecules in the JNK pathway were activated by PCV2.…”