Etanercept attenuates the development of cerulein-induced acute pancreatitis in mice: A comparison with TNF-alpha genetic deletion

TNF-alpha plays a pivotal role in the pathogenesis of acute parcreatitis. Recent studies have shown that TNF-alpha inhibition significantly ameliorates the course of experimental acute pancreatitis, but in this context, the effects of Etanercept, a novel anti-TNF-alpha agent, have not been investigated so far, The aims of the present study are (i) to assess the effects of pharmacological inhibition of TNF-alpha by means of Etanercept on the inflammatory response and apoptosis in a murine model of necrotizing acute pancreatitis and (ii) to compare the results to those observed in TNF-alpha receptor 1 knockout (TNFR1-KO) mice. Necrotizing acute pancreatitis was induced in TNF-alpha wild type for TNFR1 (WT) and TNFR1-KO mice by intraperitoneal injection of cerulein (hourly x5, 50 mu g/kg). In another group of WT mice, Etanercept was administered (5 or 10 mg/kg, s.c.) at 1 h after first cerulein injection. Control groups received saline treatment. After 24 h, biochemical, histological, and immunohistochemical evidences of acute pancreatitis developed in all cerulein-treated mice; apoptosis was also present in the pancreas. Contrarily, pancreatitis histological features, amylase and lipase levels, pancreas water content, and myeloperoxidase activity were reduced in a similar degree in Etanercept-treated and TNFR1 KO mice. Likewise, in these two groups, immunohistochemical stainings and terminal deoxynucleotidyltransferase-mediated UTP nick-end labeling assay were found negative. TNF-alpha receptor 1 gene deletion and Etanercept administration ameliorate the course of experimental acute pancreatitis in a similar degree. Future studies on clinical applications of Etanercept in pancreatitis seem promising.