International journal of molecular medicine
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Intestinal epithelial barrier dysfunction plays a critical role in the pathogenesis of inflammatory bowel disease (IBD). Anterior gradient protein 2 homologue (AGR2) assists in maintaining intestinal homeostasis in dextran sulphate sodium-induced mouse ileocolitis; however, it is unclear whether it modulates intestinal barrier function. Our study aimed to investigate the protective role of AGR2 in tumor necrosis factor (TNF)-α-induced intestinal epithelial barrier injury. ⋯ The results showed that the AGR2 mRNA and protein expression levels were both decreased in the Caco-2 cell monolayers, while AGR2 overexpression significantly ameliorated TNF-α-induced epithelial barrier hyperpermeability, increased the expression of tight junction (TJ) proteins and stabilized the cytoskeletal structure. Furthermore, AGR2 inhibited the changes in MLCK, MLC and p-MLC expression in response to TNF-α stimulation. Collectively, our study suggests that AGR2 inhibits TNF-α‑induced Caco-2 cell hyperpermeability by regulating TJ and that this protective mechanism may be promoted by inhibition of NF-κB p65-mediated activation of the MLCK/p-MLC signaling pathway.