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Background:Acute pancreatitis can induce intestinal barrier dysfunction in its early phase,which is closely related with the progression and prognosis of the disease. Intestinal mucus layer not only serves as a physical barrier between pathogens and epithelium,but also plays a critical role in the maintenance of intestinal barrier function. Aims:To investigate the expression and role of mucin 2 (MUC2)in injured intestinal barrier in rats with acute necrotizing pancreatitis (ANP). Methods:Forty-two male Sprague-Dawley rats were randomly divided into two groups:the sham operation (SO)group and ANP group,which were induced via a retrograde injection of 3. 5% sodium taurocholate into biliopancreatic duct. Blood,pancreas and colon samples were obtained 6,12 and 24 hours after establishing the ANP model for determination of serum amylase and D-lactate (an indicator of intestinal permeability)and histopathological examination. PAS/ AB staining was used to observe the colon mucus layer and goblet cells,and the expressions of MUC2 and inflammatory cytokines in colonic tissue were detected by real-time PCR. Results:ANP models were successfully established. In ANP group,obvious colonic injury,increased intestinal permeability,thinner colon mucus layer,reduced mucin-containing goblet cells,down-regulated MUC2 mRNA and up-regulated tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β)and interferon-γ (IFN-γ)mRNAs were observed at each time point as compared with those in SO group (P < 0. 05). Spearman correlation coefficient revealed that MUC2 expression was negatively correlated with the intestinal permeability and expression of inflammatory cytokines in ANP group (P < 0. 05). Conclusions:Transcription of MUC2 is significantly down-regulated in colonic tissue of ANP rats,and might be associated with increased intestinal permeability and excessive expression of inflammatory cytokines in early phase of ANP.
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Objective To investigate the alteration of C/EBP α,C/EBP β and endoplasmic reticulum stress (ERS) related molecules (IRE1α and sXBP1) expression in pancreatic tissues in rats with hypertriglyceridemia related acute pancreatitis.Methods Ninety six Sprague Dawley (SD) rats were divided into 4 groups:control group,hypertriglyceridemia (HTG) group (n =24,fed with high fat diet for 2 weeks),AP group (n =24),HTG + AP group (n =24),and AP was induced by peritoneal injection of cerulein.The rats were sacrificed at 3,6,9,24 h after AP induction,respectively.The pathological changes of the pancreatic tissues were observed and scored by HE staining.Plasma levels of IL-1β,IL-6 and TNF-α were measured by ELISA.The expression of IRE1α,sXBP1,C/EBPoα,C/EBPβ mRNA were analyzed by real time PCR.The expressions of IRE1α,sXBP1,NF-kB,C/EBPα and C/EBPβ protein were determined by Western Blot.The expressions of C/EBPα and C/EBPβ proteins were also determined by immunohitochemistry.Results After two weeks of high fat diet,serum levels of triglyceride(TG) and total cholesterol (TC) in HTG group,HTG + AP group were much higher than those of the control group,and the difference was statistically significant (P ＜ 0.05).The pancreatic tissue injury was more severe in HTG + AP group,particularly at 9 h (P ＜ 0.05).And plasma IL-1β,IL-6 and TNF-α levels were also much higher in HTG + AP group when compared with that of AP group,the differences were all significant at 9 h (P=0.011;P=0.034;P =0.027).After AP induction,IRE1,sXBP1,C/EBP and C/EBPβ mRNA began to be up-regulated at 3 h,and IRE1 mRNA reached the highest level at 24 h,sXBP1 mRNA at 9 h,while C/EBP and C/EBPβ mRNA reached the highest level at 6 h.Compared with AP group,IRE1,sXBP1,C/EBP and C/EBPβ mRNA levels were much higher in HTG + AP group.In addition,as to IRE1 and sXBP1 mRNA,the difference was significant at 3,6,9,24 h,and C/EBP mRNA at 6,9,24 h,C/EBPβ mRNA at 6 and 9 h (P ＜ 0.05).After AP induction,IRE1α,sXBP1 and NF-kB proteins in the pancreatic tissue began to be up-regulated at 3 h,and all reached the highest level at 9 h.IRE1α,sXBP1 and NF-kB proteins were up-regulated more obviously in HTG + AP group,and the up-regulation in HTG + AP group was higher than that in AP group,and the high expressions of C/EBPα and C/EBPβ proteins could only be detected at 6 and 9 h in the HTG + AP group,while there was no expression detected in AP group.Conclusions C/EBPα,C/EBPβ,IRE1α and sXBP1 may be involved in the pathogenesis of HTG related AP,and IRE1α/sXBP1 pathway and C/EBPoα,C/EBPβ may mediate the pathologic injury and inflammation process of HTG related AP.
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BACKGROUND: In the past, guided tissue regeneration materials were produced by 13-tricalcium phosphate (β-TCP) and gelatin (Gel), but the production of fiber membrane by electro-spinning technique was reported less.OBJECTIVE: To prepare a new kind of Gel with β-TCP hybrid nanofibrous membrane and testing its biocompatibility compared with polylactic acid (PLLA) and poly(lactide-co-glycolide) (PLGA) membrane.METHODS: The β-TCP/Gel guided tissue regeneration membrane was made by electro-spinning technique.Scanning electron microscopy (SEM) was employed to observe membrane surface.MTT test was performed to compare toxicity among β-TCP/Gel,PLLA, and PLGA membranes.RESULTS AND CONCLUSION: The β-TCP/Gel membrane was porous, and β-TCP granules were nodosity-adhered on surface of Gel.The average diameter of fiber was 500-600 nm.The distribution of fiber ranged from 200 to 500 nm.There was no significant difference in toxicity among PLLA, PLGA, and negative control group (P > 0.05).The results suggested that the β-TCP /Gel membrane was low cytotoxicity and suitable for tissue engineering.It would be a promising material for periodontal tissue regeneration.