Dominant Negative p38 Mitogen-Activated Protein Kinase Expression Inhibits NF-κB Activation in AR42J Cells

Background: The role of the p38 mitogen-activated protein (MAP) kinase in acute pancreatitis pathogenesis is controversial. We hypothesize that p38 plays a role in regulating NF-κB activation in exocrine pancreatic cells. Methods: AR42J cells incorporating an NF-κB-responsive luciferase reporter, with and without adenoviral transduction of DNp38, were stimulated with cholecystokinin (CCK) or tumor necrosis factor-α (TNF-α) prior to measuring NF-κB activation. Results: CCK-or TNF-α-stimulated NF-κB-dependent gene transcription (luciferase assay) was substantially subdued by DNp38 expression. These findings were confirmed by electrophoretic mobility shift assay. Nuclear translocation of the p65 NF-κB subunit following agonist stimulation was evident (supershift). Characterization studies showed excellent adenoviral infection efficiency and cell viability in our AR42J cell model. Agonist-stimulated dose- and time-dependent p38 activation, with inhibition by DNp38 expression, was also con- firmed. Conclusion: The p38 MAP kinase regulates NF-κB pathway activation in exocrine pancreatic cells, and thus potentially plays a role in the mechanism of acute pancreatitis pathogenesis.