Cellular localization of connectiv tissue growth factor in panceatic fibrosis in mice

Abstract

Connective tissue growth factor (CTGF) is a pro‐fibrogenic molecule that is implicated in the pathogenesis of pancreatic fibrosis. In this study, immunohistochemistry was used to determine the cellular localization of CTGF in the pancreata of C57/BL6 mice in which chronic pancreatitis was induced by 50 μg/kg cerulein i.p. given 6 times a day, 3 days/wk for 4 wks. Pancreatic fibrosis was confirmed by the presence of interstitial collagen deposition as detected by Sirius Red staining and by the presence of activated (α‐SMA‐positive) pancreatic stellate cells (PSC). Compared to control mice, real time PCR of diseased pancreatic tissue showed significant up‐regulation of mRNA for key fibrogenic markers including collagens I, III and VI, MMP‐2, TIMPs ‐1 and ‐2, TGF‐β1 and CTGF. CTGF was localized by incubation of pancreatic sections with rabbit or chicken anti‐CTGF antibodies and immunoreactivity was detected by peroxidase staining using light microscopy or immunofluorescence using confocal microscopy. CTGF was detected primarily in acinar cells and duct‐like cells with weaker production by presumptive activated PSC. A high proportion of CTGF producing cells were also positive for PCNA. CTGF production is thus a feature of multiple actively proliferating cell types in the fibrotic pancreas supporting a role for CTGF in tissue remodeling, matrix production, and cell survival after injury.