Monolayers stained for the tight junction protein ZO-1 (green) and nuclei stained with DAPI (blue) were detected by laser scanning confocal microscopy. intestinal barrier destruction, as reflected by loss of cellCcell contact, reduced IPEC-J2 cell viability A 77-01 and transepithelial electrical resistance, and disruption of tight junction protein zonula occludens-1. In contrast, the treatment substantially counteracted these detrimental effects and preserved the barrier function. and LGG also achieved barrier protection, partly by directly inhibiting ETEC attachment. Together, the results indicate that specific strains of can enhance gut barrier function through cytoprotective HSP induction and fortify the cell protection against ETEC challenge through tight junction protein modulation and direct conversation with pathogens. (ETEC). The consequent contamination can be fatal for young animals, A 77-01 especially postweaning piglets and children under the age of five (Bailey 2009; Croxen and Finlay 2010). The pathogenesis of ETEC starts with bacterial attachment to the host small intestinal epithelium cells (IECs), followed by production of heat-labile and heat-stable enterotoxins. These toxins facilitate more intimate pathogen colonization, disrupt the tight junction (TJ) structure of the mucosal barrier, and result in a leaky gut. This is followed by pathogen internalization, where the pathogen subverts host cell processes and manipulates pathways in coordination with invasion, ultimately leading to cell death (Handl et?al. 1988; Croxen and Finlay 2010). A 77-01 In the Rabbit polyclonal to ABHD12B face of pathogen challenge, A 77-01 it is essential to constitute an efficient intestinal barrier that separates the internal tissue from the external environment to provide the front line of defense. The maintenance of barrier function is associated with dynamic modulation of the TJ complex, which encloses IECs against the uptake of food antigens, gut microbes, and other macromolecules (Ulluwishewa et?al. 2011). In this regard, the porcine jejunal epithelial cell line IPEC-J2 is a suitable in vitro model for investigating interactions between bacteria (commensal or transient) and the small intestinal epithelium. IPEC-J2 provides A 77-01 high specificity for pig studies and is analogous to human gut physiology (Brosnahan and Brown 2012). IPEC-J2 cells grown on permeable filters allow epithelium differentiation and polarization in a two-compartment system (apical and basolateral), therefore reconstituting a small intestinal villus-like cell phenotype (Geens and Niewold 2011; Diesing et?al. 2012; Zakrzewski et?al. 2013). A substantial body of evidence suggests that probiotics are able to counteract the pathogenic effects of ETEC (Guarner 2008; Ringel et?al. 2012; Klingspor et?al. 2014). In particular, lactobacilli, normal inhabitants of the small intestine, are commonly used as probiotics in human and animal applications (De Lange et?al. 2010; Ringel et?al. 2012). Earlier studies have shown promising effects of probiotic lactobacilli. For instance, GG (LGG) protects intestinal Caco-2 cells from ETEC K88-associated inflammation (Roselli et?al. 2006) and young adult mouse colon cells (YAMC) from oxidant stress (Tao et?al. 2006). Certain strains of can ameliorate dextran sodium sulfate-induced colitis in rats, where the protective mechanism seems to be associated in maintaining intestinal barrier integrity (Dicksved et?al. 2012). Furthermore, it has been shown that strain JCM 2012T is usually involved in the regulation of IL-12 production, which influences host homeostasis (Shida et?al. 2009). Indeed, probiotics exhibit a great diversity of functions and the mechanisms of importance in promoting health need further elucidation. Induction of cytoprotective heat shock protein (HSP) 27 and HSP72 in IECs is usually one action that can be taken by probiotics in sustaining intestinal homeostasis (Petrof et?al. 2004; Liu et?al. 2014b). The resulting HSP carries out crucial housekeeping functions to maintain mucosal barrier integrity against various stimuli in the intestinal microenvironment. HSP27 is usually associated with cytoskeleton stabilization (Mounier and Arrigo 2002), whereas both HSP27 and HSP72 (homolog to HSP70) display.