Expression and significance of osteopontin in chronic pancreatitis rats / 中华胰腺病杂志

ABSTRACT

Objective To detect the expression of osteopontin (OPN) in the pancreatic tissues of chronic pancreatitis (CP) rats,and analyze the relationship between the expression of OPN and pancreatic fibrosis.Methods A total of 20 male Wistar rats were randomly divided into control group and CP model group.Control group was treated by tail vein injection of absolute ethanol and glycerol,and CP model group received a single tail vein injection of dibutyltin dichloride (DBTC) to construct CP model.Six weeks after the procedure,the rats were sacrificed to obtain pancreatic tissue,and pathological examinations were routinely performed.Sirius-red staining was used to assess the degree of pancreatic fibrosis.The expression of OPN,α-SMA and Col I in the pancreas of CP rats was detected by immunohistochemistry and Western blot,and the relationship between the expression of OPN and the degree of fibrosis was analyzed.Results In CP model group,3 rats died.In the 7 rats which survived,light microscopic examination observed great proliferation of fibrous tissue in pancreatic interlobular space,vacuolization and necrosis of acinous cells,the infiltration of inflammatory cells in the pancreatic interlobular space and dilation of pancreatic duct.Results of Sirius-red staining showed that a large number of fresh red stripe and reticular collagen fibers were deposited in the interlobular space of the pancreatic tissues in the CP group,whereas there were only a few fiber deposited around the blood vessels and the pancreatic duct in the control group and the stained area in CP group (51 ± 11)％ was significantly larger than that of control group (9 ± 4)％ and the difference was statistically significant (P ＜ 0.01).The results of immunohistochemistry showed that the expression of OPN in CP group was strong positive in 3 rats and positive in 4 rats,which in control group was weak positive in 3 rats and negative in 7 rats.OPN expression in CP group was significantly higher than that in control group (Z =-5.170,P ＜ 0.01),and the expression of OPN was positively correlated with the Sirius-Red staining area (r =0.790,P ＜ 0.01).Western-blot results showed that the expression of OPN,α-SMA and Col I in CP group was significantly higher than that in control group (0.70 ±0.22 vs 0.24 ±0.11,0.71 ± 0.10 vs 0.06 ± 0.01,2.83 ± 1.42 vs 0.39 ± 0.07),and the differences were statistically significant (all P ＜ 0.05).Conclusions A single tail vein injection of DBTC can be used to successfully establish CP rat model.The expression of OPN is significantly increased in the CP group and is positively correlated with pancreatic fibrosis.