Anti-inflammatory effects of tacrolimus in a rat model of acute pancreatitis.
ABSTRACT The present study investigated the treatment effects of the immunosuppressive agent, tacrolimus (FK506), on rats with acute necrotizing pancreatitis (ANP). Methods: We used the taurocholate-induced model of acute necrotizing pancreatitis (ANP) in rats that were divided into seven groups: The sham group included animals that underwent sham operations. The ANP group contained ANP rats induced by taurocholate. The tacrolimus groups contained ANP rats treated with tacrolimus at three different time points (prior to the induction of ANP, immediately after the induction of ANP, one hour after the induction of ANP). The somatostatin group included ANP rats treated with somatostatin. The glucocorticoids group contained ANP rats treated with glucocorticoids. At 3, 6 and 12 hours after the induction of taurocholate, blood samples were collected for TNF-alpha, IL-1beta and amylase assays, and lung and pancreas tissues were harvested for histopathological study and edema evaluation. Results: Tacrolimus administered prior to the induction of ANP and immediately after the induction of ANP caused a significant decrease in the twenty two-hour mortality rate (p<0.05). However, tacrolimus did not decrease the mortality rate when administered one hour after the induction of ANP (p>0.05). Treatment with all three drugs (tacrolimus, somatostatin and glucocorticoids) resulted in a significant decrease of serum amylase, lung edema, and serum TNF-alpha and IL-1beta levels. Pancreatic and pulmonary morphological alterations were improved. Conclusions: Tancrolimus can decrease pancreatic and pulmonary injury. The effect of tacrolimus treatment is the same as that of somatostain and glucocroticoids. It is also more effective to administer the drug earlier.
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ABSTRACT: The aim of this study was to investigate hypoxia effects on vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and VEGFR-2 in human umbilical vein endothelial cells (HUVEC) and to determine their modulation by the peptide somatostatin (SRIF) and its analogues. The involvement of signal transducer and activator of transcription (STAT) 3 and hypoxia inducible factor (HIF)-1 was also investigated. Quantitative real-time PCR, Western blot and ELISA were used. Hypoxia upregulated VEGF expression and release, whereas it downregulated VEGFR-1 and VEGFR-2. In contrast, neither the expression nor the phosphorylation of the platelet-derived growth factor receptor (PDGFR) β was affected by hypoxia. SU1498 at 1 μM did not affect pVEGFR-2 and pPDGFRβ, whereas at 20 μM it inhibited pVEGFR-2, but not pPDGFRβ. Upregulated VEGF expression and release were prevented by SU1498, which also inhibited the hypoxia-induced pSTAT3 and HIF-1α. Blocking pSTAT3 with S3I-201 inhibited HIF-1α and VEGF upregulation, suggesting the existence of an autocrine loop involving STAT3, HIF-1, VEGF and VEGFR-2. Endothelial cells express somatostatin (SRIF) receptors (sst(1-5)) although less is known in HUVEC. We found that sst(1) and sst(4) were expressed by HUVEC with sst(1) more expressed than sst(4) mRNA. Hypoxia downregulated sst(1), whereas it upregulated sst(4). The sst(1) downregulation, but not the sst(4) upregulation, was prevented by SU1498, S3I-201 or YC-1, an inhibitor of HIF-1α. SRIF and the sst(1) agonist CH-275, but not the sst(4) agonist L803,087 and the sst(2)/sst(3)/sst(5) agonist octreotide, prevented hypoxia effects on VEGF and its receptors. In addition, SRIF and CH-275 inhibited the hypoxia-induced pSTAT3 and HIF-1α accumulation. Our results suggest that SRIF acting at sst(1) limits upregulated VEGF expression and release through a control on the activity of STAT3 and HIF-1, supporting the possible use of sst(1) agonists in antiangiogenic therapies.Archiv für Experimentelle Pathologie und Pharmakologie 06/2011; 383(6):593-612. · 2.15 Impact Factor
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ABSTRACT: This study aimed at T-cell inhibition by immunosuppressants to reduce cell damage and improve the course of severe acute pancreatitis (SAP). A taurocholate-induced SAP was used and 5 groups were compared: (1) rapamycin + FTY720, (2) rapamycin, (3) FTY720, (4) cortisol, and (5) control: sodium chloride. Drugs were applied intravenously at SAP induction; 6 hours later, rats were killed. Interleukin (IL)-1, IL-6, IL-10, tumor necrosis factor α, platelet-activating factor, amylase, and lipase were measured in serum and myeloperoxidase tissue activity in pancreas, kidney, lung, liver, and spleen. Edema, inflammation, and necrosis were histologically determined in pancreas. CD4/CD8 immunohistochemistry was performed. Inflammation was ameliorated in all 4 treated groups. Necrosis development was suppressed by FTY720, FTY720 + rapamycin, and cortisol. IL-6 and IL-10 were significantly lower in these groups. Amylase was higher in all treatment groups compared to the controls except for the cortisol group. Tumor necrosis factor α, lipase, and myeloperoxidase activity were not affected by therapy. CD4+/CD8+ cells were significantly less in FTY720-treated pancreata. Rapamycin and FTY720 ameliorated the severity of SAP, which may be due to early suppression of helper T cells. FTY720 reduced the development of pancreatic necrosis. The combination of both immunosuppressants did not show advantage to treatment with FTY720 alone.Pancreas 04/2012; 41(7):1086-91. · 2.95 Impact Factor
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ABSTRACT: The protein tyrosine phosphatases (PTPs) SHP-1, SHP-2 and PTP1B are overexpressed early on during the development of cerulein (Cer)-induced acute pancreatitis (AP) in rats, and their levels can be modulated by some species of mitogen-activated protein kinases (MAPKs), the intracellular levels of cAMP and by general leukocyte infiltration, the latter at least for SHP-2 and PTP1B. In this study we show that Cer treatment activates extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) but not p38 MAPK during the early phase of Cer-induced AP (2hours after the first injection of Cer). Therefore, by using the MAPKs inhibitors SP600125 (a specific JNK inhibitor) and PD98059 (a specific ERK inhibitor), we have unmasked the particular MAPK that underlies the modulation of the expression levels of these PTPs. JNK would act by preventing SHP-1 protein expression from increasing beyond a certain level. ERK 1/2 was the main MAPK involved in the increase in SHP-2 protein expression due to Cer. JNK negatively modulated the SH2-domain containing PTPs. Both MAPKs played a role in the increase in PTP1B protein expression due to Cer. Finally, by using the white blood cell inhibitors vinblastine sulfate, gadolinium chloride and FK506 (tacrolimus), we show that the macrophage activity or T-lymphocytes does not modulate the expression of any of the PTPs, although neutrophil infiltration was found to be a regulator of SHP-2 and PTP1B protein expression due to Cer.Biochimica et Biophysica Acta 11/2013; · 4.66 Impact Factor