Bone marrow mesenchymal stem cells in acute necrotizing pancreatitis complicated with multiple organ dysfunction

Abstract

Objective To investigate the role of bone marrow mesenchymal stem cells (MSC) in early acute necrotizing pancreatitis (ANP) complicated with multiple organ dysfunction (MODS). Methods Fifty Sprague-Dawley (SD) rats weighing 180 ～ 220 g were randomly assigned into 5 groups (n = 10). Group A was the normal negative control without any treatment, ANP was induced in Group B rats by intraperitoueal injections with L-arginine 2.5 g/kg body weight twice, Group C received Hoechst33258 labeled autologous bone marrow mMSCs one day after ANP model induction, Group D was the group of mMSCs transplantation, in which the mice were given the isolated mMSCs via the tail vein 3 days prior to the ANP induction, Group E was the stem cell mobilized group treated by the injection of granulocyte-colony stimulating factor (G-CSF) into rats 33258 and transplanted into the arigiual cavity or via the tail vein. Three days after the injury was induced, the rats were sacrificed, the tissues of pancreas, liver and intestine were harvested and the morphological changes were examined. A part of samples were snap-frozen and the presence of labeled MSC in the cryostat prepared was examined directly by fluorescence microscopy. The positive sections were chosen for further immunofluorescence assay. Anti-CK19 immunofluorescence staining was performed in pancreatic and liver sections;and Pan Cytokeratin immunofluorescence staining were performed in intestinal sections. The mortality rates within 30 days were recorded. Results The control group had normal tissue structures, with no death. 3 hour after ANP induction, there were mass hemorrhagic ascites, pefi-pancreas saponification, pancreatic disorganization, necrosis, phlogocyte infiltration;liver and intestine involvement and necrosis in rats in Group B and C with a mortality rate 40%. 3 hour after ANP induction, there were less ascites, mild pancreatic edema, intact acinns lobula, no interstitial tissue exudation, less pancreatic hemorrhage and necrosis, less phlogocyte infiltration;less liver and intestine injuries in rats in Group D and E with a mortality rate 10%. The pancreatic, liver, and intestinal sections in the control group and ANP group had no flavo green fluorescence;while the sections in Group C had some flavo green fluorescence but they were negative for immunofluorescence staining;in addition, the sections in Group D and E had plenty of flavo green fluorescence and CK19 (+) cells were present in pancreatic and liver tissues and Pan Cytokeratin (+) cells were present in intestinal tissues. Conclusions MSC played an important role in the process of pathological repair in ANP complicated with MODS, autologous or transplanted MSC had protective effects. Key words: Pancreatitis, acute necrotizing; Mesenchymal stem cells; Bone marrow; Multiple organ failure