SiRNA-mediated PIAS1 silencing promotes inflammatory response and leads to injury of cerulein-stimulated pancreatic acinar cells via regulation of the P38MAPK signaling pathway

Our aim in this study was to investigate the changes of inflammatory response by protein inhibitor of activated signal transducer and activator of transcription 1 (PIAS1) gene silencing treatment in cerulein-stimulated AR42J cells, and relate them to changes in cell injury, thus providing evidence for developing clinical therapies. This study examined the effects of cerulein on the activity of P38 mitogen activated protein kinase (P38MAPK), c-jun NH2-terminal kinase/stress-activated protein kinase and the inflammatory mediators released by PIAS1 gene-silenced AR42J cells. Consequently, the markers including DNA ladder, cell apoptotic rat, cell cycles, levels of cell cycle and apoptotic related factors were used to determine the effects of PIAS1 gene silencing on the cerulein-induced cell injury. The results indicated that in the cerulein-stimulated PIASI silencing cells, the activity of P38MAPK was enhanced, while at the same time, the levels of inflammatory mediators such as the tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and matrix metallopeptidase-9, were markedly higher than those of other cerulein-stimulated cells. Thus, the cerulein-stimulated PIASI gene-silenced cells obviously increased cell arrest in the G1/M phase by increasing P21 and P27 expression, and also induced apoptosis by regulating the P53 signaling pathway. This study suggests that the down-regulation of PIAS1 is efficacious at enhancing the expression of inflammatory mediators and inducing cell injury in acute pancreatitis (AP), thus deteriorating the severity of disease. It provides evidence that PIAS1 is a potential therapeutic target for AP.