Calpain I inhibitor ameliorates the indices of disease severity in a murine model of cerulein-induced acute pancreatitis.

Abstract

Nuclear factor-kappaB (NF-kappaB) is a transcription factor which plays a pivotal role in the induction of genes involved in the response to injury and inflammation. Calpain I inhibitor is a potent antioxidant which is an effective inhibitor of NF-kappaB. This study examined whether the postulate that calpain I inhibitor attenuates experimental acute pancreatitis. In a murine model we measured NF-kappaB activation, expression of intercellular adhesion molecule (ICAM) 1, nitrotyrosine, inducible nitric oxide synthase (iNOS), nuclear enzyme poly(ADP-ribose) synthetase (PARS), myeloperoxidase, malondialdehyde, amylase and lipase and determined histological evidence of lung and pancreas injury in four groups: control (saline only), cerulein, calpain I inhibitor plus cerulein and calpain I inhibitor plus saline. Intraperitoneal injection of cerulein in mice resulted in severe, acute pancreatitis characterised by oedema, neutrophil infiltration, tissue haemorrhage and necrosis and elevated serum levels of amylase and lipase. Infiltration of pancreatic and lung tissue with neutrophils (measured as increase in myeloperoxidase activity) was associated with enhanced lipid peroxidation (increased tissue levels of malondialdehyde). Immunohistochemical examination demonstrated a marked increase in immunoreactivity for nitrotyrosine, iNOS and PARS in the pancreas and lung of cerulein-treated mice. In contrast, pre-treatment with calpain I inhibitor markedly reduced: the degree of pancreas and lung injury; upregulation/expression of ICAM-1; staining for iNOS, nitrotyrosine and PARS; and lipid peroxidation. Additionally, calpain I inhibitor treatment significantly prevented the activation of NF-kappaB as suggested by the inhibition of IkappaB-alpha; degradation in the pancreas tissues after cerulein administration. Taken together, our results clearly demonstrate that prevention of the activation of NF-kappaB by calpain I inhibitor ameliorates experimental murine acute pancreatitis.