Trypsin activates PAR2 inhibits the expression of tight junction protein through activation of NLRP3 inflammasome pathway in gastroesophageal reflux disease

Abstract

BACKGROUND: Trypsin activates protease-activated receptor 2 (PAR2), which mediates the initiation of mucosal inflammation in gastroesophageal reflux disease (GERD). Nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome is crucial for the activation of pyroptosis, and inflammation becomes more severe. This study aimed to investigate the effects of PAR2 and NLRP3 on the tight junction (TJ) in the pathogenesis of GERD and the therapeutic effects of rabeprazole. Methods: We constructed a rat GERD model using cardia myotomy and pyloric ligation. Two weeks following rabeprazole administration, we assessed the esophageal mucosal barrier using western blot and immunohistochemistry for Claudin-1 and Claudin-4, while exploring the expression of PAR2, NLRP3, and Caspase-1. Human esophageal epithelial cells (HEECs) were produced with overexpression of PAR2 and treated with PAR2 agonist and inhibitor, respectively, to observe the changes in the NLRP3 pathway and esophageal TJ protein. RESULTS: The expression of Claudin-1 and Claudin-4 decreased, whereas the expression of PAR2, NLRP3, and Caspase-1 increased in the GERD group compared to the Sham group. PAR2 inhibitor reversed these processes. In HEECs, trypsin activated PAR2 and NLRP3 and disrupted TJ protein. PAR2 agonist played an identical role. PAR2 inhibitor blocked these processes. The effectiveness of rabeprazole was outperformed by the addition of a PAR2 inhibitor. CONCLUSION: Trypsin in reflux can cause GERD by activating the PAR2 and NLRP3 inflammasome pathway, which impairs the esophageal mucosal barrier. Our research will aid in the identification of potential targets for the treatment of GERD.