Inhibition of Shigella sonnei-induced epithelial barrier disruption by surface-layer associated proteins of lactobacilli from Chinese fermented food

Abstract

Surface-layer associated proteins (SLAP) of Lactobacillus paracasei ssp. paracasei M5-L and Lactobacillus casei Q8-L were examined to identify the functional basis for their protection within intestinal epithelial cells. The results showed that SLAP of M5-L and Q8-L remained active in a trypsin solution and retained a 45-kDa protein band, similar to that observed in controls. In contrast, under conditions of simulated gastric juice, the SLAP were partially degraded. Inhibitory effects of SLAP on adherence of Shigella sonnei to HT-29 cells were assessed with use of exclusion, competition, and replacement assays. In response to M5-L at 50 μg/mL SLAP, an inhibition ratio of 33% was obtained, while for Q8-L at 400 μg/mL SLAP, the inhibition ratio was 48%. Hoechst 33258 test results showed that cells infected with S. sonnei and co-incubated with SLAP of M5-L and Q8-L were only partially apoptotic, with apoptosis rates of 37.67 and 43.67%, respectively. These levels of apoptosis were substantially lower than that observed with cells infected with S. sonnei alone. In addition, the SLAP of Q8-L and M5-L reduced downstream caspase-1 activity and further modified apoptotic cell damage. Finally, SLAP of M5-L and Q8-L were also able to prevent S. sonnei-induced membrane damage by inhibiting delocalization of zonula occludens (ZO)-1 and reducing the amount of occludin produced by S. sonnei.

Protective effect of surface‐layer proteins from four Lactobacillus strains on tumor necrosis factor‐α‐induced intestinal barrier dysfunction

“…Consistent with our results, the abnormal expression and localization of occludin and ZO‐1 were improved by heat‐inactivated mixed Lactobacillus , so as to alleviate the symptoms of intestinal leakage caused by an inflammatory factor mixture 28 . Furthermore, surface‐related proteins of Lactobacillus paracasei and Lactobacillus casei responded to membrane damage induced by Shigella sonnei by restoring the expression of ZO‐1 29 …”

“…28 Furthermore, surface-related proteins of Lactobacillus paracasei and Lactobacillus casei responded to membrane damage induced by Shigella sonnei by restoring the expression of ZO-1. 29 Abundant studies have shown that TNF-⊍ may stimulate intestinal barrier damage via inducing an imbalance in the secretion of inflammatory factors. 22 IL-8, as a pro-inflammatory factor, was responsible for regulating inflammatory response and TJ function.…”

Probiotics Supplementation Improves Intestinal Permeability, Obesity Index and Metabolic Biomarkers in Elderly Thai Subjects: A Randomized Controlled Trial

“…Zhang et al [27] demonstrated that the surface-layer associated proteins (SLAP) of L. paracasei ssp. paracasei M5-L and L. casei Q8-L protect the bacteria-mediated epithelial barrier disruption by suppressing the occludin production and inhibiting the delocalization of zonula occludens-1.…”

Dynamic comparison of gut microbiota of mice infected with Shigella�flexneri via two different infective routes

“…The protective effects of Lactobacilli, probiotic bacteria, are greater against invasive bacteria such as S. sonnei, when compared to non-invasive bacteria such as Vibrio cholerae (34). However, the mechanism of the inhibitory effect of lactic acid bacteria on Shigella has been mostly investigated in vitro (35,36), and it is not fully understood how these inhibitory effects are exerted on pathogenic bacteria in the complex intestinal microecological environment. These inhibitory effects may be associated with decreases in host gene expression, microRNA regulation and a substantial reshaping of the Listeria-monocytogenes transcriptome (37).…”