Ascites of severe acute pancreatitis in rats transcriptionally up-regulates expression of interleukin-6 and -8 in vascular endothelium and mononuclear leukocytes

Evaluation of serum histone concentrations and their associations with hemostasis, markers of inflammation, and outcome in dogs with naturally occurring acute pancreatitis

OBJECTIVE

To compare serum concentrations of histones and inflammatory markers in dogs with acute pancreatitis and healthy control dogs, investigate associations of these variables with coagulation test results and survival (vs nonsurvival) to hospital discharge, and examine the prognostic utility of clinical findings and routine laboratory and coagulation tests in affected dogs.

ANIMALS

36 dogs.

PROCEDURES

Dogs with findings consistent with acute pancreatitis (n = 29) and healthy control dogs (7) were enrolled in a prospective, observational study. Serum concentrations of histones, interleukin (IL)-6, and tumor-necrosis factor-α were assessed for all dogs. Clinical (including ultrasonographic) findings, relevant history, routine laboratory and coagulation test results, and outcomes were recorded for dogs with pancreatitis. Variables were assessed to determine an association with outcome for affected dogs and hospitalization time for survivors; histone concentrations and markers of inflammation were compared among survivors, nonsurvivors, and controls. Correlation between quantitative variables was investigated.

RESULTS

Serum histone and IL-6 concentrations did not differentiate survivors (n = 23) from nonsurvivors (6); IL-6 concentrations in affected dogs were correlated with 1,2-o-dilauryl-rac-glycero glutaric acid-(6'-methylresorufin) ester lipase activity (r_S = 0.436) and hospitalization time (r_S = 0.528). Pancreatitis-associated peritoneal fluid, obtundation, and jaundice were more common, and serum bilirubin concentration, serum alanine aminotransferase and aspartate aminotransferase activities, and prothrombin and activated partial thromboplastin times were greater in nonsurvivors than in survivors. Thromboelastometric changes consistent with hypercoagulability were detected in survivors; hypocoagulability was detected in 2 nonsurvivors.

CONCLUSIONS AND CLINICAL RELEVANCE

Serum histone concentrations were not associated with presence of acute pancreatitis or outcome for affected dogs. Further research is needed to investigate the clinical and therapeutic implications of hypocoagulability, hepatocellular injury, and pancreatitis-associated peritoneal fluid in affected dogs.

Pancreatitis-associated ascitic fluid induces proinflammatory cytokine expression in THP-1 cells by inhibiting anti-inflammatory signaling

OBJECTIVES

We investigated whether pancreatitis-associated ascitic fluid (PAAF) could induce the expression of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) in THP-1 cells and the mechanism(s) involved.

METHODS

THP-1 cells were divided into control and PAAF groups. The PAAF group was incubated with different final concentrations of PAAF, whereas the control group was incubated with culture medium. Effects and mechanisms were determined by measuring the levels of TNF-α and IL-6 mRNA expression; phospho-p38-MAPK, nuclear factor κB, peroxisome proliferator-activated receptor γ activation; and the effect on the inhibitory activity of SB203580 and BAY-117082.

RESULTS

In response to PAAF, overexpression of TNF-α and IL-6 mRNA was found in THP-1 cells compared with those of the corresponding control (P < 0.05), and in a dose-dependent manner. The levels of phospho-p38 and nuclear factor κB p65 were also increased in different PAAF groups, whereas low expression of peroxisome proliferator-activated receptor γ was found compared with the control group (P < 0.05). Furthermore, we presented that the inflammatory response could be partly alleviated by inhibitors SB203580 or BAY-117082, whereas it was markedly inhibited by the simultaneous treatment of 2 inhibitors.

CONCLUSIONS

Pancreatitis-associated ascitic fluid up-regulated proinflammatory cytokines by interfering with proinflammatory and anti-inflammatory signaling pathways, thus exacerbating activation in acute pancreatitis.

Efficacy and mechanism of Salvia miltiorrhizae injection in the treatment of rats with severe acute pancreatitis

To study the efficacy and mechanism of Salvia miltiorrhizae injection in the treatment of severe acute pancreatitis. SAP rat models were prepared and randomly divided into model control group and treated group. The sham-operated group was also set. At 3, 6 and 12 h after operation, the mortality rate, ascitic volumes, pathological changes in the pancreas, contents of amylase and endotoxin in plasma as well as IL-6, IL-18, ET-1 and NO in serum, the staining intensity of Bax and NF-kappaB p56 proteins, and the changes in apoptosis index of pancreatic cells in rats in each group were observed. The pathological severity scores (at 3, 6 and 12 h after operation), contents of plasma endotoxin (at 6 and 12 h after operation) and serum IL-6 (at 6 and 12 h after operation) were significantly lower than those in model control group (P < 0.05, P < 0.01 and P < 0.01, respectively); the staining intensity and the product of the staining intensity and positive staining rate of Bax protein in the pancreas were significantly higher than those in model control group (P < 0.01). Salvia miltiorrhizae is able to reduce the contents of plasma endotoxin and serum IL-6, promote the expression of Bax protein in pancreas, improve the pathological changes in the pancreas, and decrease the mortality rate of rats, thereby showing therapeutic effect on rats with SAP.

Effects of Salvia miltiorrhiza on intercellular adhesion molecule 1 protein expression in the lungs of rats with severe acute pancreatitis or obstructive jaundice

OBJECTIVE

The objective of the study was to observe the effects of Salvia miltiorrhiza on intercellular adhesion molecule 1 (ICAM-1) protein expression in the lungs of rats with severe acute pancreatitis (SAP) or obstructive jaundice (OJ).

METHODS

A total of 288 rats were used for SAP- and OJ-associated experiments. The rats were randomly divided into sham-operated, model control, and treated group. According to the difference of time points after operation, the SAP rats of each group were subdivided into 3-, 6-, and 12-hour groups, whereas the OJ rats were divided into 7-, 14-, 21-, and 28-day groups. The contents of interleukin (IL) 6, IL-18, nitric oxide, malondialdehyde, and superoxide dismutase in serum were determined, and pathological changes and ICAM-1 protein expression in the lungs were observed.

RESULTS

Compared with the respective model control groups, in treated groups of SAP and OJ rats, the numbers of dead rats declined; serum superoxide dismutase content significantly increased, and serum IL-18, IL-6, and malondialdehyde contents were significantly decreased; the positive staining intensity of ICAM-1 protein in the lungs decreased significantly (P < 0.05, P < 0.01, or P < 0.001); and pathological changes in the lungs were relieved.

CONCLUSIONS

Salvia miltiorrhiza plays a positive role in the protection of the lungs of SAP and OJ rats.

Signal transduction of MCP-1 expression induced by pancreatitis-associated ascitic fluid in pancreatic acinar cells

Pancreatitis-associated ascitic fluid (PAAF) is known to contribute to the progression of acute pancreatitis (AP). We have investigated the capability of PAAF to activate the expression of MCP-1 in pancreatic acinar cells and the involvement of MAPK, NF-kappaB and STAT3 as downstream signalling transduction pathways. The actions of dexamethasone (Dx) and N-acetylcysteine (NAC) on the PAAF's acinar effects have also been evaluated. Acinar cells were incubated for 1 hr with PAAF collected from rats with severe AP induced by sodium taurocholate in the absence or presence of Dx (10(-7) M) or NAC (30 mM). MCP-1 mRNA expression, phospho-p38-MAPK, IkappaB alpha, nuclear p65 levels and nuclear translocation of STAT3 were analysed. In response to PAAF, overexpression of MCP-1, phosphorylation of p38-MAPK, degradation of IkappaB alpha and increases in p65 nuclear levels and STAT3 activity were found in acinar cells. PAAF-mediated MCP-1 up-regulation was completely suppressed by Dx and NAC. MAPK activation was only inhibited by NAC, NF-kappaB activation was repressed by Dx and NAC, and STAT3 pathway was strongly blocked by Dx and significantly reduced by NAC. In conclusion, acinar cells were activated by PAAF to produce MCP-1, mainly via NF-kappaB and STAT3 pathways. Both downstream pathways were targeted by Dx and NAC to repress the PAAF-mediated acinar MCP-1 up-regulation.

Signal transduction of MCP-1 expression induced by pancreatitis-associated ascitic fluid in pancreatic acinar cells

Pancreatitis-associated ascitic fluid (PAAF) is known to contribute to the progression of acute pancreatitis (AP). We have investigated the capability of PAAF to activate the expression of MCP-1 in pancreatic acinar cells and the involvement of MAPK, NF-κB and STAT3 as downstream signalling transduction pathways. The actions of dexamethasone (Dx) and N-acetylcysteine (NAC) on the PAAF’s acinar effects have also been evaluated. Acinar cells were incubated for 1 hr with PAAF collected from rats with severe AP induced by sodium taurocholate in the absence or presence of Dx (10⁻⁷ M) or NAC (30 mM). MCP-1 mRNA expression, phospho-p38-MAPK, IκBα, nuclear p65 levels and nuclear translocation of STAT3 were analysed. In response to PAAF, overexpression of MCP-1, phosphorylation of p38-MAPK, degradation of IκBα and increases in p65 nuclear levels and STAT3 activity were found in acinar cells. PAAF-mediated MCP-1 up-regulation was completely suppressed by Dx and NAC. MAPK activation was only inhibited by NAC, NF-κB activation was repressed by Dx and NAC, and STAT3 pathway was strongly blocked by Dx and significantly reduced by NAC. In conclusion, acinar cells were activated by PAAF to produce MCP-1, mainly via NF-κB and STAT3 pathways. Both downstream pathways were targeted by Dx and NAC to repress the PAAF-mediated acinar MCP-1 up-regulation.

Experimental study of therapeutic efficacy of Baicalin in rats with severe acute pancreatitis

AIM: To observe the therapeutic efficacy of Baicalin in rats with severe acute pancreatitis (SAP) and explore its therapeutic mechanisms.

METHODS: The SAP rat models were randomly divided into the model control group, Baicalin treatment group, octreotide treatment group and sham operation group. All groups were randomly subdivided into 3 h, 6 h and 12 h groups with 15 rats in each group. The survival, ascites volume and pathological changes of pancreas in all rats were observed at different time points after operation. The plasma amylase content and serum TNF-α, IL-6, malonaldehyde (MDA) and PLA₂ contents were also determined.

RESULTS: The survival was not obviously different between the treated groups, and was significantly higher in treated groups at 12 h compared to the model control group (P < 0.05, 15 vs 10). The ascites/body weight ratio at 3 h and 6 h was significantly lower in Baicalin treatment group compared to the model control group and octreotide treatment group (P < 0.05, 1.00 vs 2.02 and 1.43 and P < 0.001, 2.29 (1.21) vs 2.70 (0.80) and 2.08 (2.21), respectively). The contents of amylase, TNF-α, IL-6, MDA and PLA₂ were significantly lower in the treated groups than in the model control group (P < 0.05, 4342 vs 5303, 5058 vs 6272 in amylase, P < 0.01, 21.90 vs 36.30, 23.80 vs 39.70, 36 vs 54.35 in MDA and 56.25 vs 76.10 in PlA₂, or P < 0.001, 65.10 and 47.60 vs 92.15 in TNF-α, 3.03 vs 5.44, 2.88 vs 6.82, 2.83 vs 5.36 in IL-6, respectively). The pathological scores of pancreas in the treated groups were significantly lower than that in the model control group (P < 0.05, 9.00 vs 10.05, 6.00 vs 9.00, 8.00 vs 10.05), but no marked difference was found between the treated groups.

CONCLUSION: The Baicalin injection has significant therapeutic effects on SAP rats, its effects are similar to those of octreotide. The Baicalin injection is also cheap and has a big application range, quite hopefully to be used in clinical treatment of SAP.

The usefulness of early laparoscopic surgery for determining a medical treatment plan in severe acute pancreatitis

A 41-year-old woman presented with sudden onset severe epigastric pain. She was diagnosed as having severe acute pancreatitis (SAP) with an APACHE II score of 10, and initially, general supportive therapy was performed. Because the patient's condition kept worsening, early laparoscopic surgery was performed. It revealed swelling, hemorrhagic necrosis of the pancreas, and massive fluid collection in the abdominal cavity. Kocherization and bursectomy were performed for these lesions, and drainage tubes were indwelled. The white blood cell count (WBC) and serum interleukin-6 value prominently improved shortly after the operation, and the WBC count remained at a low level. The patient gradually recovered and was finally discharged 39 days after her initial presentation. To summarize, we performed a successful exploration for SAP, and we found that postoperative continuous lavage effectively eliminated toxic enzymatic exudates in the abdominal cavity and prevent them from circulating. Regarding SAP with peritonitis, early laparoscopic surgery is very useful for determining the pathological extent of the disease and for selecting appropriate treatment options.

Spatial and temporal dynamics of the endothelium

The endothelium is a highly metabolically active organ that is involved in many physiological processes, including the control of vasomotor tone, barrier function, leukocyte adhesion and trafficking, inflammation, and hemostasis. Endothelial cell phenotypes are differentially regulated in space and time. Endothelial cell heterogeneity has important implications for developing strategies in basic research, diagnostics and therapeutics. The goals of this review are to: (i) consider mechanisms of endothelial cell heterogeneity; (ii) discuss the bench-to-bedside gap in endothelial biomedicine; (iii) revisit definitions for endothelial cell activation and dysfunction; and (iv) propose new goals in diagnosis and therapy. Finally, these themes will be applied to an understanding of vascular bed-specific hemostasis.

Endothelial biomedicine: its status as an interdisciplinary field, its progress as a basic science, and its translational bench-to-bedside gap

The endothelium, a layer of endothelial cells lining the luminal surface of all blood vessels, functions as a highly metabolically active organ spatially distributed throughout the body. Despite enormous advances in our understanding of endothelial cell biology, little awareness of this organ reaches clinical practice. The present study aims to document the extent and scope of the bench-to-bedside gap in endothelial biomedicine, and to offer hypotheses to explain the gaping chasm. A PubMed search using keywords "endothelial cells" and "endothelium" yielded over 90,000 publications, increasing exponentially over the past decade. A Scirus search without date restriction returned journal results for the endothelium not greatly fewer than for the epithelium. A survey of representative vascular biology meetings revealed a high percentage of talks related to the endothelium. The number of grants awarded by the National Institutes of Health for studies in endothelial cell biology continues to steadily increase. At the bedside, however, few clinicians give consideration to the health of the endothelium. A survey of the major medical textbooks revealed a paucity of index entries for "endothelial cells" or "endothelium." The endothelium does not offer itself for inspection, palpation, percussion, and/or auscultation. No convenient blood tests measure endothelial function. The authors propose to explain the bench-to-bedside gap in endothelial biomedicine as a function of (1) historical constraints, (2) the unseen and diffuse nature of the cell layer, (3) the complexity of the system, and (4) its adaptability. Until the bench-to-bedside gap closes, the enormous potential of the endothelium as a diagnostic, preventive, and therapeutic target will remain largely untapped.

Biliary pancreatitis-associated ascitic fluid activates the production of tumor necrosis factor-alpha in acinar cells

OBJECTIVE

Acute pancreatitis is associated with increased cytokine release from different cell sources. We have investigated the ability of acinar cells, in comparison with inflammatory peripheral blood cells, to produce tumor necrosis factor (TNF)-alpha in response to pancreatitis-associated ascitic fluid (PAAF).

DESIGN

Controlled, randomized animal study.

SETTING

University research laboratory.

SUBJECTS

Male Wistar rats.

INTERVENTIONS

Flow cytometry using phycoerythrin-labeled monoclonal anti-TNF-alpha antiserum.

MEASUREMENTS AND MAIN RESULTS

PAAF (20%, v:v) obtained from rats with acute pancreatitis induced by bile-pancreatic duct obstruction significantly increased TNF-alpha production in acinar cells, as measured by flow cytometry using phycoerythrin-labeled monoclonal anti-TNF-alpha antiserum. Neither heating of PAAF nor the addition of soybean trypsin inhibitor or neutralizing amounts of anti-TNF-alpha monoclonal antiserum reduced the acinar cell TNF-alpha production. Monocytes and lymphocytes did not produce TNF-alpha in response to PAAF. Likewise, the typical monocyte and lymphocyte stimulating factors-lipopolysaccharide (10 microg/microL) and phorbol 12-myristate 13-acetate (250 ng/mL) plus ionomycin (1 microg/mL), respectively-were not able to produce TNF-alpha in acinar cells. By comparison of the two acinar cell populations differentiated by flow cytometry, R2 cells (with higher forward scatter values) showed a greater ability to produce TNF-alpha in response to PAAF than R1 cells. Acinar cell nuclear factor-kappaB was activated, but TNF-alpha production was not totally inhibited in presence of N-acetyl cysteine (30, 100 mM).

CONCLUSIONS

The production of TNF-alpha from different cell sources is selectively activated. PAAF may be involved in the pathophysiology of acute pancreatitis by TNF-alpha production in acinar cells through mechanisms partially mediated by nuclear factor-kappaB activation. PAAF components, such as TNF-alpha or trypsin, are not responsible for acinar cell activation. TNF-alpha was induced by heat-resistant PAAF factors, displaying acinar cells with higher forward scatter (R2) a greater ability to increase the TNF-alpha production than R1 cells.

N/A

N/A

Endothelium as an organ system

The endothelium is a highly dynamic cell layer that is involved in a multitude of physiologic functions, including the control of vasomotor tone, the trafficking of cells and nutrients, the maintenance of blood fluidity, and the growth of new blood vessels. Over the past several decades, advances in basic research of the endothelium have far outstripped those in the clinic. One explanation for this growing bench-to-bedside chasm relates to the inflexible and largely outdated nature of the present-day medical infrastructure. The constraints of medical subspecialization have created a conceptual blind spot, namely, the inability to appreciate the endothelium for what it is: a cell layer that is teeming with life, every bit as active as any other organ in the body. The overall goal of this review is to bring the endothelium "to life" and to argue that future breakthroughs in biomedicine are contingent on acceptance of the endothelium as a bona fide organ system.

Macrophage migration inhibitory factor is a critical mediator of severe acute pancreatitis

BACKGROUND & AIMS

Macrophage migration inhibitory factor (MIF), originally described as an inhibitor of the random migration of macrophages, has been shown recently to be involved in the pathogenesis of several inflammatory diseases such as sepsis. The aim of this study was to clarify the role of MIF in acute pancreatitis (AP).

METHODS

Hemorrhagic necrotizing pancreatitis and edematous pancreatitis were induced by the injection of taurocholic acid (TCA pancreatitis) and cerulein (cerulein pancreatitis), respectively, on male Wistar rats. MIF levels in ascitic fluids, serum, and the organs were determined. The effects of anti-MIF antibody were examined on the prognosis of rats with TCA pancreatitis and of female CD-1 mice with choline-deficient, ethionine-supplemented, diet-induced model of severe AP. In addition, serum MIF levels in AP patients and in healthy controls were measured.

RESULTS

Serum and ascitic MIF levels in TCA pancreatitis were increased rapidly and decreased gradually thereafter. Ascitic MIF levels were also increased in cerulein pancreatitis, but to a lesser degree. MIF level was increased in the lung in TCA pancreatitis, but not in the pancreas and the liver. Prophylactic (1 hour before and immediately after induction) administration of anti-MIF antibody significantly improved the survival rate of rats with TCA pancreatitis. The survival rate of mice with severe AP was also improved significantly by the antibody treatment. Serum MIF levels were higher in severe AP patients than mild AP patients and healthy controls.

CONCLUSIONS

These results suggest a role of MIF in the pathogenesis of severe AP.

Establishment and characterization of a simian virus 40-immortalized rat pancreatic stellate cell line

Activated pancreatic stellate cells (PSCs) have recently been implicated in the pathogenesis of pancreatic fibrosis and inflammation. Primary PSCs can be subcultured only several times because of their limited growth potential. A continuous cell line would be valuable in studying molecular mechanisms of these pancreatic disorders. The aim of this study was to establish an immortalized cell line of rat PSCs. PSCs were isolated from the pancreas of male Wistar rats, and the simian virus 40 T antigen was introduced to PSCs by retrovirus-mediated gene transfer. This procedure yielded an actively growing cell line, designated as SAM-K. This cell line has been passaged repeatedly for almost 2 years, and is thus likely immortalized. SAM-K cells retained morphological characteristics of primary PSCs, and expressed alpha-smooth muscle actin, glial fibrillary acidic protein, type I collagen, fibronectin, and prolyl hydroxylases. The level of p53 expression was very high in SAM-K cells. Proliferation of SAM-K cells was stimulated by serum and platelet-derived growth factor-BB. Interleukin-1beta (IL-1beta) activated nuclear factor-kappaB, activator protein-1, and three classes of mitogen-activated protein (MAP) kinases: extracellular signal-regulated kinase1/2, c-Jun N-terminal kinase, and p38 MAP kinase. IL-1beta induced expression of intercellular adhesion molecule-1 and monocyte chemoattractant protein-1, both of which were abolished in the presence of pyrrolidine dithiocarbamate, a specific inhibitor of nuclear factor-kappaB activation. IL-1beta-induced monocyte chemoattractant protein-1 was partially inhibited by specific inhibitors of MAP kinase kinase (U0126) and of p38 MAP kinase (SB203580) whereas intercellular adhesion molecule-1 expression was not altered by the inhibitors. Thus, SAM-K would be useful for in vitro studies of cell biology and signal transduction of PSCs.

Lung injury in acute pancreatitis: mechanisms, prevention, and therapy

Lung injury is the most pertinent manifestation of extra-abdominal organ dysfunction in pancreatitis. The propensity of this retroperitoneal inflammatory condition to engender a diffuse and life-threatening lung injury is significant. Approximately one third of patients will develop acute lung injury and acute respiratory distress syndrome, which account for 60% of all deaths within the first week. The variability in the clinical course of pancreatitis renders it a vexing entity and makes demonstration of the efficacy of any specific intervention difficult. The distinct pathologic entity of pancreatitis-associated lung injury is reviewed with a focus on etiology and potential therapeutic maneuvers.

Ascites of rat experimental model of severe acute pancreatitis induces lung injury

The molecular mechanisms that lead from acute pancreatitis (AP) to multiple organ failure remain to be clarified. We previously reported that ascitic fluids from a rat model of severe acute pancreatitis (pancreatitis-associated ascitic fluids, PAAF) transcriptionally activated endothelial cells and leukocytes in vitro. To clarify the role of ascitic fluids on the development of multiple organ failure in AP, we examined the effects of PAAF on the prognosis and immunohistologic findings in cerulein pancreatitis, an experimental model of mild pancreatitis in vivo. Intraperitoneal injection of PAAF decreased the survival rates in a dose-dependent manner. Histologically, destruction of vessels, alveolar septal thickening, interstitial hypertrophy, and infiltration of inflammatory cells were prominent in the lung of PAAF-injected rats. Transcription factor, nuclear factor KB (NF-kappaB) was activated and the mRNA levels of tumor necrosis factor-alpha and interleukin-1beta were increased in the lung of the PAAF-injected rats. The permeability index assessed by Evans blue assay and the lung myeloperoxidase activity levels were significantly higher in the PAAF-injected rats than in controls. Inhibition of NF-kappaB ameliorated the histologic findings and improved the survival rates. Our results suggest that PAAF play a role in the pathogenesis of lung injury in severe AP, at least in part through the activation of NF-kappaB.