Inflammatory Stimuli Promote Oxidative Stress In Pancreatic Acinar Cells Via Toll-Like Receptor 4/Nuclear Factor-Kappa B Pathway

The Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-kappa B) pathway is vital to the pathogenesis of acute pancreatitis (AP). The aim of the present study was to identify the mechanism of the activation of the TLR4/NF-kappa B signaling pathway in the viability of primary pancreatic cells. The cells were stimulated with lipopolysaccharide (LPS) for the activation of NF-kappa B signaling. Next, the reactive oxygen species (ROS) level was evaluated by detecting the concentration of malondialdehyde and glutathione peroxidase. Cell viability was measured by Cell Counting Kit-8 and MTT assays, while the percentage of apoptosis was detected by flow cytometry. Quantitative polymerase chain reaction was used to detect TLR4, B-cell lymphoma 2 (Bcl2), Bcl2-associated X protein (Bax) and phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1) expression levels. Western blot assay was also conducted to detect TLR4 protein expression, while the activity of NF-kappa B signaling was measured by determining the p65 and phosphorylated p65 protein levels. In addition, the effect of TLR4 overexpression or treatment with TLR4 antagonists in the presence of LPS stimulation was investigated. The results revealed that ROS levels were increased and cell viability was decreased in LPS-stimulated pancreatic acinar cells. TLR4, Bax and PMAIP1 levels were increased, Bcl2 expression was decreased and NF-kappa B signaling was activated in LPS-stimulated pancreatic acinar cells. Furthermore, pancreatic cells with TLR4 overexpression exhibited increased ROS level and decreased viability. Finally, the effect caused by LPS stimulation was partially reversed by treatment of pancreatic acinar cells with TLR4 antagonists. In conclusion, the current study investigated a novel regulatory mechanism of the TLR4/NF-kappa B pathway in LPS-stimulated pancreatic cells, which may contribute to pancreatitis. The damage of these cells due to increased ROS levels was observed to occur through activation of the TLR4/NF-kappa B pathway.