Antifibrotic role of chemokine CXCL9 in experimental chronic pancreatitis induced by trinitrobenzene sulfonic acid in rats

Abstract

Chemokines have been shown to play an important role in the pathogenesis of pancreatitis, but the role of chemokine CXCL9 in pancreatitis is poorly understood. The aim of this study was to investigate whether CXCL9 was a modulating factor in chronic pancreatitis. Chronic pancreatitis was induced in Sprague–Dawley rats by intraductal infusion of trinitrobenzene sulfonic acid (TNBS) and CXCL9 expression was assessed by immunohistochemistry, Western blot analysis and enzyme linked immunosorbent assay (ELISA). Recombinant human CXCL9 protein (rCXCL9), neutralizing antibody and normal saline (NS) were administered to rats with chronic pancreatitis by subcutaneous injection. The severity of fibrosis was determined by measuring hydroxyproline in pancreatic tissues and histological grading. The effect of rCXCL9 on activated pancreatic stellate cells (PSCs) in vitro was examined and collagen 1α1, TGF-β1 and CXCR3 expression was assessed by Western blot analysis in isolated rat PSCs. Chronic pancreatic injury in rats was induced after TNBS treatment and CXCL9 protein was markedly upregulated during TNBS-induced chronic pancreatitis. Although parenchymal injury in the pancreas was not obviously affected after rCXCL9 and neutralizing antibody administration, rCXCL9 could attenuate fibrogenesis in TNBS-induced chronic pancreatitis in vivo and exerted antifibrotic effects in vitro, suppressing collagen production in activated PSCs. In conclusion, CXCL9 is involved in the modulation of pancreatic fibrogenesis in TNBS-induced chronic pancreatitis in rats, and may be a therapeutic target in pancreatic fibrosis.