Mast cells-derived MiR-223 destroys intestinal barrier function by inhibition of CLDN8 expression in intestinal epithelial cells

BACKGROUND: Mast cells (MCs) have been found to play a critical role during development of inflammatory bowel disease (IBD) that characterized by dysregulation of inflammation and impaired intestinal barrier function. However, the function of MCs in IBD remains to be fully elucidated. RESULTS: In our study, we used exosomes isolated from human mast cells-1 (HMCs-1) to culture with NCM460, HT-29 or CaCO2 of intestinal epithelial cells (lECs) to investigate the communication between MCs and lECs. We found that MCs-derived exosomes significantly increased intestinal epithelial permeability and destroyed intestinal barrier function, which is attributed to exosome-mediated functional miRNAs were transferred from HMCs-1 into lECs, leading to inhibit tight junction-related proteins expression, including tight junction proteins 1 (TJP1, ZO-1), Occludin (OCLN), Claudin 8 (CLDN8). Microarray and bioinformatic analysis have further revealed that a panel of miRNAs target different tight junction-related proteins. Interestingly, miR-223 is enriched in mast cell-derived exosome, which inhibit CLDN8 expression in IECs, while treatment with miR-223 inhibitor in HT-29 cells significantly reversed the inhibitory effect of HMCs-1-derived exosomes on CLDN 8 expression. Most importantly, enrichment of MCs accumulation in intestinal mucosa of patients with IBD compared with those healthy control. CONCLUSIONS: These results indicated that enrichment of exosomal miR-223 from HMCs-1 inhibited CLDN8 expression, leading to destroy intestinal barrier function. These finding provided a novel insight of MCs as a new target for therapeutic treatment of IBD.

Correlation of Sugar Molecular Probes with Inflammatory Factors and Claudin-8 in Intestinal Permeability in Colitis Rats / 胃肠病学

Background:Intestinal permeability plays an important role in the development of ulcerative colitis. Sugar molecular probes is a safe and non-invasive method to measure intestinal permeability,and its correlation with inflammatory factors and claudin-8 is not clear. Aims:To explore the correlation of sugar molecular probes with TNF-α,CRP and claudin-8 in intestinal permeability in colitis rats. Methods:Twenty-four rats were assigned randomly to model group and normal control group. Colitis model was induced by DSS solution. Expressions of TNF-α,CRP were determined by ELISA,and expression of claudin-8 was determined by immunohistochemistry. Sugar molecular probes were determined by high performance liquid chromatography. Correlations of inflammatory factors and claudin-8 with sugar molecular probes were analyzed. Results:Compared with normal control group,expressions of colonic tissue TNF-α and CRP were significantly increased while expression of claudin-8 was significantly decreased in model group(P < 0. 01);secretion of lactulose and sucrolose,ratio of lactulose/ mannitol( L/ M)were significantly increased( P < 0. 01)while mannitol secretion was significantly decreased(P < 0. 01). Secretion of lactulose and sucrolose were positively correlated with expressions of TNF-α and CRP(P < 0. 01),but negatively with expression of claudin-8(P < 0. 01). L/ M ratio and mannitol secretion were negatively correlated with expressions of TNF-α and CRP(P < 0. 01),but positively with expression of claudin-8(P <0. 01). Conclusions:Sugar molecular probes and expressions of TNF-α,CRP,claudin-8 have similar results in predicting intestinal permeability in rats. Sugar molecular probes can be used as a potential method to measure intestinal permeability.