Xylobiose treatment strengthens intestinal barrier function by regulating Claudin 2 and Heat Shock Protein 27 expression in human Caco-2 cells

Background: Xylobiose, a non-digestible disaccharide, largely contributes to the beneficial physiological effects of xylooligosaccharides. However, there is insufficient evidence to assess the direct effect of xylobiose on the intestinal barrier function. Here, we investigated the intestinal barrier function in human intestinal Caco-2 cells treated with xylobiose.

Results: A total of 283 genes were upregulated and 256 genes were downregulated in xylobiose-treated Caco-2 cells relative to the controls. Then, we focused on genes related to intestinal barrier function, such as tight junction (TJ) and heat shock protein (HSP). Xylobiose decreased the expression of the TJ gene Claudin 2 (CLDN2) and increased the expression of the cytoprotective HSP genes HSPB1 and HSPA1A, which encode HSP27 and HSP70, respectively. Immunoblot analysis confirmed that xylobiose suppressed CLDN2 expression and enhanced HSP27 and HSP70 expression. qRT-PCR and promoter assays indicated that xylobiose post-transcriptionally regulated CLDN2 and HSPB1 levels. Additionally, selective inhibition of phosphatidyl-3-inositol kinase (PI3K) inhibited xylobiose-mediated CLDN2 expression, while HSP27 expression induced by xylobiose was sensitive to the inhibition of PI3K, mitogen-activated protein kinase kinase, and Src.

Conclusion: Our results revealed that xylobiose suppresses CLDN2 and increases HSP27 expression in intestinal Caco-2 cells via post-transcriptional regulation, potentially strengthening intestinal barrier integrity; however, these effects seem to occur via different signaling pathways. Our findings may help to assess the physiological role of xylobiose. This article is protected by copyright. All rights reserved.

Non-digestible saccharide; heat shock protein; intestinal cell; tight junction; xylobiose.