Changes of gastric and intestinal blood flow, serum phospholipase A_2 and interleukin-1β in rats with acute necrotizing pancreatitis

AIM:To explore the relationship between gastric and intestinal microcirculatory impairment and inflammatory mediators released in rats with acute necrotizing pancreatitis (ANP). METHODS: A total of 64 rats were randomized into control group and ANP group. ANP model was induced by injection of 5% sodium taurocholate under the pancreatic membrane. Radioactive biomicrosphere technique was used to measure the gastric and intestinal tissue blood flow at 2 and 12 h after the induction of ANP, meanwhile serum phospholipase A2 (PLA2) activities and interleukin-1β levels were determined. Pathologic changes in pancreas, gastric and intestinal mucosae were studied. RESULTS: The gastric blood flow in ANP group (0.62±0.06 and 0.35±0.05) mL/(min·g) was significantly lower than that in control group (0.86±0.11 and 0.85±0.06) mL/(min·g) (P<0.01) at 2 and 12 h after induction of ANP. The intestinal blood flow in ANP group (0.80±0.07 and 0.50±0.06) mlV(min·g) was significantly lower than that in control group (1.56±0.18 and 1.61±0.11) mL/(min·g) (P<0.01). Serum PLA2 activities (94.29±9.96 and 103.71± 14.40) U/L and IL-1β levels (0.78±0.13 and 0.83±0.20)μg/L in ANP group were higher than those in control group (65.27±10.52 and 66.63±9.81) U/L, (0.32±0.06 and 0.33±0.07)μg/L (P<0.01). At 2 and 12 h after introduction of the model, typical pathologic changes were found in ANP. Compared with control group, the gastric and intestinal mucosal pathologic changes were aggravated significantly (P<0.01) at 12 h after induction of ANP. Gastric and intestinal mucosal necrosis, multiple ulcer and hemorrhage occurred. CONCLUSION: Decrease of gastric and intestinal blood flow and increase of inflammatory mediators occur simultaneously early in ANP, both of them are important pathogenic factors for gastric and intestinal mucosal injury in ANP.

Interleukin-22 ameliorates acute severe pancreatitisassociated lung injury in mice

AIM: To investigate the potential protective effect of exogenous recombinant interleukin-22(r IL-22) on L-arginine-induced acute severe pancreatitis(SAP)-associated lung injury and the possible signaling pathway involved.METHODS: Balb/c mice were injected intraperitoneally with L-arginine to induce SAP. Recombinant mouse IL-22 was then administered subcutaneously to mice. Serum amylase levels and myeloperoxidase(MPO) activity in the lung tissue were measured after the L-arginine administration. Histopathology of the pancreas and lung was evaluated by hematoxylin and eosin(HE) staining. Expression of B cell lymphoma/leukemia-2(Bcl-2), Bcl-x L and IL-22RA1 m RNAs in the lung tissue was detected by real-time PCR. Expression and phosphorylation of STAT3 were analyzed by Western blot. RESULTS: Serum amylase levels and MPO activity in the lung tissue in the SAP group were significantly higher than those in the normal control group(P < 0.05). In addition, the animals in the SAP group showed significant pancreatic and lung injuries. The expression of Bcl-2 and Bcl-x L m RNAs in the SAP group was decreased markedly, while the IL-22RA1 m RNA expression was increased significantly relative to the normal control group(P < 0.05). Pretreatment with PBS did not significantly affect the serum amylase levels, MPO activity or expression of Bcl-2, Bcl-x L or IL-22RA1 m RNA(P > 0.05). Moreover, no significant differences in the degrees of pancreatic and lung injuries were observed between the PBS and SAP groups. However, the serum amylase levels and lung tissue MPO activity in the r IL-22 group were significantly lower than those in the SAP group(P < 0.05), and the injuries in the pancreas and lung were also improved. Compared with the PBS group, r IL-22 stimulated the expression of Bcl-2, Bcl-x L and IL-22RA1 m RNAs in the lung(P < 0.05). In addition, the ratio of p-STAT3 to STAT3 protein in the r IL-22 group was significantly higher than that in the PBS group(P < 0.05).CONCLUSION: Exogenous recombinant IL-22 protects mice against L-arginine-induced SAP-associated lung injury by enhancing the expression of anti-apoptosis genes through the STAT3 signaling pathway.

Mechanisms of interleukin-22's beneficial effects in acutepancreatitis

Acute pancreatitis(AP) is a disorder characterized by parenchymal injury of the pancreas controlled by immune cell-mediated inflammation. AP remains a significant challenge in the clinic due to a lack of specific and effective treatment. Knowledge of the complex mechanisms that regulate the inflammatory response in AP is needed for the development of new approaches to treatment, since immune cell-derived inflammatory cytokines have been recognized to play critical roles in the pathogenesis of the disease. Recent studies have shown that interleukin(IL)-22, a cytokine secreted by leukocytes, when applied in the severe animal models of AP, protects against the inflammation-mediated acinar injury. In contrast, in a mild AP model, endogenous IL-22 has been found to be a predominantly antiinflammatory mediator that inhibits inflammatory cell infiltration via the induction of Reg3 proteins in acinar cells, but does not protect against acinar injury in the early stage of AP. However, constitutively over-expressed IL-22 can prevent the initial acinar injury caused by excessive autophagy through the induction of the antiautophagic proteins Bcl-2 and Bcl-XL. Thus IL-22 plays different roles in AP depending on the severity of the AP model. This review focuses on these recently reported findings for the purpose of better understanding IL-22's regulatory roles in AP which could help to develop a novel therapeutic strategy.

Enhanced expression of interleukin-18 in serum and pancreas of patients with chronic pancreatitis

AIM： To investigate interleukin-18 （IL-18） in patients with chronic panreatitis （CP）. METHODS： We studied 29 patients with CP and 30 healthy controls. Peripheral blood mononuclear cells （PBMC） were isolated and incubated with 50 mmol/L ethanol, lipopolysaccharide （LPS） （doses 25 g/L, 250 g/L, 2500 g/L） and both agents for 24 h. Levels of IL-18 in the supernatants, and levels of IL-18, IL-12, interferon （IFN）-T and soluble CD14 in the serum were analysed by EI_ISA technique. Expression of IL-18 in PBMC was investigated by reverse-transcription （RT）-PCR. IL-18 protein levels in CP tissue and in normal pancreas were studied by ELISA technique. IL-18 levels in PBMC and pancreatic tissue were determined by Westernblot. Immunohistochemistry for pancreatic IL-18 expression was performed.RESULTS： In patients, IL-18 serum levels were significantly enhanced by 76% （mean： 289.9 ± 167.7 ng/L） compared with controls （mean： 165.2 ± 43.6 ng/L; P 〈 0.0005）. IL-12 levels were enhanced by 25% in patients （18.3 ± 7.3 ng/L） compared with controls （14.7 ± 6.8 ng/L, P = 0.0576） although not reaching the statistical significance. IFN-γ, and soluble CD14 levels were not increased. In vitro, LPS stimulated significantly and dosedependently IL-18 secretion from PBMC. Incubation with ethanol reduced LPS-stimulated IL-18 secretion by about 50%. The mRNA expression of IL-18 in PBMC and the response of PBMC to ethanol and LPS was similar in CP patients and controls. In PBMC, no significant differences in IL-18 protein levels were detected between patients and controls. IL-18 protein levels were increased in CP tissues compared to normal pancreatic tissues. IL-18 was expressed by pancreatic acinar cells and by infiltrating inflammatory cells within the pancreas. CONCLUSION： IL-18 originates from the chronically inflammed pancreas and appears to be involved in the fibrotic destruction of the organ.

Therapeutic effects of Caspase-1 inhibitors on acute lung injury in experimental severe acute pancreatitis

AIM： To assess the therapeutic effect of Caspase-1 inhibitors （ICE-I） on acute lung injury （ALI） in experimental severe acute pancreatitis （SAP）. METHODS： Forty-two SD rats were randomly divided into 3 groups： healthy controls （HC, n = 6）; SAP-S group （n = 18）; SAP-ICE-i group （n = 18）. SAP was induced by retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. HC rats underwent the same surgical procedures and duct cannulation without sodium taurocholate infusion, in SAP-S group, rats received the first intraperitoneal injection of isotonic saline 2 h after induction of acute pancreatitis and a repeated injection after 12 h. In SAP-ICE-I group, the rats were firstly given ICE inhibitors intraperitoneally 2 h after induction of pancreatitis. As in SAP-S group, the injection was repeated at 12 h. Serum 1L-1β was measured by EUSA. Intrapulmonary expression of Caspase-1, IL-1β and IL-18 mRNA were detected by semi-quantitative RT-PCR. The wet/dry weight ratios and histopathological changes of the lungs were also evaluated. RESULTS： Serum IL-1β levels in SAP-S group were 276.77 ± 44.92 pg/mL at 6 h, 308.99 ± 34.95 pg/mL at 12 h, and 311.60 ± 46.51 pg/mL at 18 h, which were increased significantly （P 〈 0.01, vs HC）. in SAP- ICE-I group, those values were decreased significantly （P 〈 0.01, vs SAP-S）. intrapulmonary expression of Caspase-1, IL-1β and IL-18 mRNA were observed in the HC group, while they were increased significantly in the SAP-S group （P 〈 0.01, vs HC）. The expression of IL-lβ and IL-18 mRNA were decreased significantly in the SAP- ICE-I group （P 〈 0.01, vs SAP-S）, whereas Caspase-1 mRNA expression had no significant difference （P 〉 0.05）. The wet/dry weight ratios of the lungs in the SAP-S group were increased significantly （P 〈 0.05 at 6 h, P 〈 0.01 at 12 h and 18 h, vs HC） and they were decreased significantly in the SAP-ICE-I group （P 〈 0.05, vs SAP-S）.Caspase-1 inhibitors ameliorated the severity of ALl in SAP.CONCLUSION： Caspase-1 activation, and overproduction of IL-1β and IL-18 play an important role in the course of ALI, and Caspase-1 inhibition is effective for the treatment of ALI in experimental SAP.

Caspase-1 inhibition alleviates acute renal injury in rats with severe acute pancreatitis

AIM: To assess the effect of inhibition of caspase-1 on acute renal injury in rats with severe acute pancreatitis (SAP).

Pharmacological approach to acute pancreatitis

The aim of the present review is to summarize the current knowledge regarding pharmacological prevention and treatment of acute pancreatitis (AP) based on experimental animal models and clinical trials. Somatostatin (SS) and octreotide inhibit the exocrine production of pancreatic enzymes and may be useful as prophylaxis against Post Endoscopic retrograde cholangiopancreatography Pancreatitis (PEP). The protease inhibitor Gabexate mesilate (GM) is used routinely as treatment to AP in some countries, but randomized clinical trials and a meta-analysis do not support this practice. Nitroglycerin (NGL) is a nitrogen oxide (NO) donor, which relaxes the sphincter of Oddi. Studies show conflicting results when applied prior to ERCP and a large multicenter randomized study is warranted. Steroids administered as prophylaxis against PEP has been validated without effect in several randomized trials. The non-steroidal anti-inflammatory drugs (NSAID) indomethacin and diclofenac have in randomized studies showed potential as prophylaxis against PEP. Interleukin 10 (IL-10) is a cytokine with anti-inflammatory properties but two trials testing IL-10 as prophylaxis to PEP have returned conflicting results. Antibodies against tumor necrosis factor-alpha (TNF-α) have a potential as rescue therapy but no clinical trials are currently being conducted. The antibiotics beta- lactams and quinolones reduce mortality when necrosis is present in pancreas and may also reduce incidence of infected necrosis. Evidence based pharmacological treatment of AP is limited and studies on the effect of potent anti-inflammatory drugs are warranted.

Ligustrazine alleviates gastric mucosal injury in a rat model of acute necrotizing pancreatitis

BACKGROUND: Acute necrotizing pancreatitis (ANP) leads to a systemic inflammatory response characterized by widespread leukocyte activation and, as a consequence, distant organ injury. The aim of this study was to explore the relationship between gastric microcirculatory impairment and inflammatory mediators released in rats and to evaluate the therapeutic effect of ligustrazine extracted from Rhizoma ligusticum wallichii on gastric mucosa injury in a rat model of ANP. METHODS: Ninety-six Sprague-Dawley rats were randomly divided into three groups: normal control (group Q; ANP without treatment (group P); and ANP treated with ligustrazine (group T). The ANP model was induced by injection of 50 g/L sodium taurocholate under the pancreatic membrane (4 ml/kg). Group C was given isovolumetric injection of 9 g/L physiological saline by the same route. Group T was injected with ligustrazine (10 ml/kg) via the portal vein. The radioactive biomicrosphere technique was used to measure the blood flow 2 and 12 hours after the induction of ANP. Samples of the pancreas and stomach were taken to assess pathological changes by a validated histology score; meanwhile, the levels of serum interleukin-1 beta (IL-1 beta) were determined. Gastric tissues were also used to measure the level of myeloperoxidase (MPO), which is expressed intracellularly in the azurophilic granules of neutrophils. RESULTS: Blood flow in group P was significantly lower than that in group C (P < 0.01). Pathological changes were significantly aggravated in group P. The gastric MPO activity in group P was significantly higher than that in group C (P < 0.01). The level of serum IL-1 beta in group P increased more significantly than that in group C (P < 0.01). Blood flow of the stomach in group T was significantly higher than that in group P after 2 hours (P < 0.01). The pathological changes were significantly alleviated in group T. The MPO activity of group T was significantly lower than that of group P (P < 0.01). Although serum IL-1 beta level of group T, was higher than of group C (P < 0.01), it was lower than that of group P (P < 0.01). There was a negative correlation between gastric blood flow and MPO activity (r=-0.983, P < 0.01), and between gastric blood flow and pathological score (r=-0.917, P < 0.05). CONCLUSIONS: Decreased gastric blood flow and increased inflammatory mediators can be seen early in ANP, and both are important factors for gastric and mucosal injury. Ligustrazine can ameliorate microcirculatory disorder and alleviate the damage to the pancreas and stomach.

Effect of IL-4 on altered expression of complement activation regulators in rat pancreatic cells during severe acute pancreatitis

AIM： To investigate the effect of IL-4 on the altered expression of complement activation regulators in pancreas and pancreatic necrosis during experimental severe acute pancreatitis （SAP）. METHODS： SAP model of rats was established by retrograde injection of 5% sodium taurocholate （1 mL/kg） into the pancreatic duct. We immunohistochemically assayed the expression of three complement activation regulators： decay accelerating factor （DAF; CD55）, 20 ku homologous restriction factor （HRF20; CD59） and membrane cofactor protein （MCP; CEH6）, in the pancreatic acinar cells of rats at 0, 3, 6, 12, and 24 h after the induction of SAP model. Meanwhile the levels of amylase and lipase were determined, and morphological examination was performed. Then, 61 rats were randomly divided into three groups. Group A （n = 21） received no treatment after the SAP model was established; group B （n = 20） was given IL-4 （8 IJg/animal） intraperitoneally 0.5 h before the SAP model was established; group C （n = 20） was given IL-4 （8 μg/animal） intraperitoneaUy 0.5 h after the SAP model was established. Plasma amylase and lipase, extent of pancreatic necrosis and expression of complement activation regulators were investigated 6 h after the induction of SAP model. RESULTS： Three complement activation regulators were all expressed in pancreatic acinar cells. MCP was not found on the basolateral surface as reported. Contrary to the gradually increasing plasma level of amylase and lipase, expression of complement activation regulators decreased after SAP model was set up. At the same time, the severity of pancreatic necrosis was enhanced. A strong negative correlation was found between the expression of MCP, DAF, CD59 in pancreatic acinar cells and the severity of pancreatic necrosis （r = -0.748, -0.827, -0.723; P〈0.01）. In the second series of experiments, no matter when the treatment of IL-4 was given （before or after the induction of SAP model）, the serum level of amylase or lipase was decreased and the extent of pancreatic necrosis was ameliorated significantly. Compared to SAP control group, the expression of DAF and CD59 in pancreas was reinforced when IL-4 was given before the induction of SAP model （P〈0.01, P〈0.05）, but the expression of MCP was not influenced （P〉0.05）. The expression of DAF was enhanced, when IL-4 was given after the induction of SAP model （P〈0.05）, but the expression of CD59 and MCP did not change （P〉0.05）. CONCLUSION： Complement activation regulators may participate in the pathogenesis of pancreatic inflammation. Downregulation of complement activation regulators expression may be one of the causes of pancreatic necrosis. IL-4 treatment may control SAP aggravation by enhancing expression of DAF and CD59 in pancreas and decreasing pancreatic necrosis. Moreover, DAF and CD59 may play an important role in the regulation of complement activation regulators during SAP.

Intestinal bacterial overgrowth in the early stage of severe acute pancreatitis is associated with acute respiratory distress syndrome

BACKGROUND In the early stage of acute pancreatitis(AP),a large number of cytokines induced by local pancreatic inflammation seriously damage the intestinal barrier function,and intestinal bacteria and endotoxins enter the blood,causing inflammatory storm,resulting in multiple organ failure,infectious complications,and other disorders,eventually leading to death.Intestinal failure occurs early in the course of AP,accelerating its development.As an alternative method to detect small intestinal bacterial overgrowth,the hydrogen breath test is safe,noninvasive,and convenient,reflecting the number of intestinal bacteria in AP indirectly.This study aimed to investigate the changes in intestinal bacteria measured using the hydrogen breath test in the early stage of AP to clarify the relationship between intestinal bacteria and acute lung injury(ALI)/acute respiratory distress syndrome(ARDS).Early clinical intervention and maintenance of intestinal barrier function would be highly beneficial in controlling the development of severe acute pancreatitis(SAP).AIM To analyze the relationship between intestinal bacteria change and ALI/ARDS in the early stage of SAP.METHODS A total of 149 patients with AP admitted to the intensive care unit of the Digestive Department,Xuanwu Hospital,Capital Medical University from 2016 to 2019 were finally enrolled,following compliance with the inclusion and exclusion criteria.The results of the hydrogen breath test within 1 wk of admission were collected,and the hydrogen production rates at admission,72 h,and 96 h were calculated.The higher the hydrogen production rates the more bacteria in the small intestine.First,according to the improved Marshall scoring system in the 2012 Atlanta Consensus on New Standards for Classification of Acute Pancreatitis,66 patients with a PaO2/FiO2 score≤1 were included in the mild AP(MAP)group,18 patients with a PaO2/FiO2 score≥2 and duration<48 h were included in the moderately SAP(MSAP)group,and 65 patients with a PaO2/FiO2 score≥2 and duration>48 h were included in the SAP group,to analyze the correlation between intestinal bacterial overgrowth and organ failure in AP.Second,ALI(PaO2/FiO2=2)and ARDS(PaO2/FiO2>2)were defined according to the simplified diagnostic criteria proposed by the 1994 European Union Conference.The MSAP group was divided into two groups according to the PaO2/FiO2 score:15 patients with PaO2/FiO2 score=2 were included in group A,and three patients with score>2 were included in group B.Similarly,the SAP group was divided into two groups:28 patients with score=2 were included in group C,and 37 patients with score>2 were included in group D,to analyze the correlation between intestinal bacterial overgrowth and ALI/ARDS in AP.RESULTS A total of 149 patients were included:66 patients in the MAP group,of whom 53 patients were male(80.3%)and 13 patients were female(19.7%);18 patients in the MSAP group,of whom 13 patients were male(72.2%)and 5 patients were female(27.8%);65 patients in the SAP group,of whom 48 patients were male(73.8%)and 17 patients were female(26.2%).There was no significant difference in interleukin-6 and procalcitonin among the MAP,MSAP,and SAP groups(P=0.445 and P=0.399,respectively).There was no significant difference in the growth of intestinal bacteria among the MAP,MSAP,and SAP groups(P=0.649).There was no significant difference in the growth of small intestinal bacteria between group A and group B(P=0.353).There was a significant difference in the growth of small intestinal bacteria between group C and group D(P=0.038).CONCLUSION Intestinal bacterial overgrowth in the early stage of SAP is correlated with ARDS.

P-selectin glycoprotein ligand 1 deficiency prevents development of acute pancreatitis by attenuating leukocyte infiltration

BACKGROUND Acute pancreatitis(AP) is rapid-onset pancreatic inflammation that causes local and systemic inflammatory response syndrome(SIRS) with high morbidity and mortality, but no approved therapies are currently available. P-selectin glycoprotein ligand 1(PSGL-1) is a transmembrane glycoprotein to initiate inflammatory responses. We hypothesized that PSGL-1 may be involved in the development of AP and would be a new target for the treatment of AP.AIM To investigate the role and mechanism of PSGL-1 in the development of AP.METHODS The PSGL-1 expression on leukocytes was detected in peripheral blood of AP patients and volunteers. Pancreatic injury, inflammatory cytokines expression, and inflammatory cell infiltration was measured in AP mouse models induced with PSGL-1 knockout(PSGL-1-/-) and wild-type(PSGL-1+/+) mice. Leukocyteendothelial cell adhesion was measured in a peripheral blood mononuclear cell(PBMC)-endothelial cell coculture system.RESULTS The expression of PSGL-1 on monocytes and neutrophils was significantly increased in AP patients. Compared with PSGL-1+/+ mice, PSGL-1-/-AP mice induced by caerulein exhibited lower serum amylase, less Interleukin-1 beta(IL-1 beta) and Interleukin-6(IL-6) expression, less neutrophil and macrophage infiltration, and reduced peripheral neutrophil and monocyte accounts. PSGL-1 deficiency alleviated leukocyte-endothelial cell adhesion via IL-6 but not IL-1 beta.CONCLUSION PSGL-1 deficiency effectively inhibits the development of AP by preventing leukocyte-endothelial cell adhesion via IL-6 stimulation and may become a potential therapeutic target for treating AP.

Relationship between expression of triggering receptor-1 on myeloid cells in intestinal tissue and intestinal barrier dysfunction in severe acute pancreatitis

BACKGROUND：Triggering receptor expressed on myeloid cells-1 （TREM-1） in the intestine was upregulated and correlated with disease activity in inflammatory bowel diseases. Membrane- bound TREM-1 protein is increased in the pancreas, liver and kidneys of patients with severe acute pancreatitis （SAP）, suggesting that TREM-1 may act as an important mediator of inflammation and subsequent extra-pancreatic organ injury. This study aimed to investigate the relationship between the expression of TREM-1 in intestinal tissue and intestinal barrier dysfunction in SAP. METHODS： Sixty-four male Wistar rats were randomly divided into a sham operation group （SO group, n=32） and a SAP group （n=32）. A SAP model was established by retrograde injection of 5% sodium deoxycholate into the bile-pancreatic duct. Specimens were taken from blood and intestinal tissue 2, 6, 12, and 48 hours after operation respectively. The levels of D-lactate, diamine oxidase （DAO） and endotoxin in serum were measured using an improved spectro-photometric method. The expression levels of TREM-1, interleukin-1β （IL-1β）, and tumor necrosis factor-α （TNF-α） mRNA in terminal ileum were detected by real-time reverse transcription-polymerase chain reaction （RT-PCR）. Specimens of the distal ileum were taken to determine pathological changes by a validated histology score. The serum levels of D-lactate, DAO and endotoxin were significantly increased in each subgroup of SAP compared with the SO group （P〈0.01, P〈0.05）. The expression levels of TREM-1, IL-1β and TNF-a mRNA in the terminal ileum in each subgroup of SAP were significantly higher than those in the SO group （P〈0.01, P〈0.05）. The expression level of TREM-lmRNA was positively correlated with IL-1βand TNF-α mRNA （r=0.956, P=0.044; r=0.986, P=0.015）, but the correlation was not found between IL-1β mRNA and TNF-a mRNA （P=0.133）. Compared to the SO group, the pathological changes were aggravated significantly in the SAP group. CONCLUSIONS： The expression level of TREM-1 in intestinal tissue of rats with SAP was elevated, leading to the release of inflammatory mediators and intestinal mucosal injury. This finding indicates that TREM-I might play an important role in the development of intestinal barrier dysfunction in rats with SAP.

Serum soluble suppression of tumorigenicity 2 as a novel inflammatory marker predicts the severity of acute pancreatitis

BACKGROUND Acute pancreatitis(AP)is an inflammatory disease in which the regulatory pathway is complex and not well understood.Soluble suppression of tumorigenicity 2(sST2)protein receptor functions as a decoy receptor for interleukin(IL)-33 to prevent IL-33/suppression of tumorigenicity 2L(ST2L)-pathwaymediated T helper(Th)2 immune responses.AIM To investigate the role of sST2 in AP.METHODS We assessed the association between sST2 and severity of AP in 123 patients enrolled in this study.The serum levels of sST2,C-reactive protein(CRP)and Th1-and Th2-related cytokines,including interferon(IFN)-γ,tumor necrosis factor(TNF)-α,IL-2,IL-4,IL-5 and IL-13,were measured by highly sensitive ELISA,and the severity of AP in patients was evaluated by the 2012 Atlanta Classification Criteria.RESULTS Serum sST2 levels were significantly increased in AP patients,and further,these levels were significantly elevated in severe AP(SAP)patients compared to moderately severe AP(MSAP)and mild AP(MAP)patients.Logistic regression showed sST2 was a predictor of SAP[odds ratio(OR):1.003(1.001–1.006),P=0.000].sST2 cutoff point was 1190 pg/mL,and sST2 above this cutoff was associated with SAP.sST2 was also a predictor of any organ failure and mortality during AP[OR:1.006(1.003–1.009),P=0.000,OR:1.002(1.001–1.004),P=0.012,respectively].Additionally,the Th1-related cytokines IFN-γand TNF-αin the SAP group were higher and the Th2-related cytokine IL-4 in the SAP group was significantly lower than those in MSAP and MAP groups.CONCLUSION sST2 may be used as a novel inflammatory marker in predicting AP severity and may regulate the function and differentiation of IL-33/ST2-mediated Th1 and Th2 Lymphocytes in AP homeostasis.

Chemokine receptor 8 expression may be linked to disease severity and elevated interleukin 6 secretion in acute pancreatitis

BACKGROUND Acute pancreatitis(AP)is an inflammatory disease,which presents with epigastric pain and is clinically diagnosed by amylase and lipase three times the upper limit of normal.The 2012 Atlanta classification stratifies the severity of AP as one of three risk categories namely,mild AP(MAP),moderately severe AP(MSAP),and severe AP(SAP).Challenges in stratifying AP upon diagnosis suggest that a better understanding of the underlying complex pathophysiology may be beneficial.AIM To identify the role of the chemokine receptor 8(CCR8),expressed by T-helper type-2 Lymphocytes and peritoneal macrophages,and its possible association to Interleukin(IL)-6 and AP stratification.METHODS This study was a prospective case-control study.A total of 40 patients were recruited from the Chris Hani Baragwanath Academic Hospital and the Charlotte Maxeke Johannesburg Academic Hospital.Bioassays were performed on 29 patients(14 MAP,11 MSAP,and 4 SAP)and 6 healthy controls as part of a preliminary study.A total of 12 mL of blood samples were collected at Day(D)1,3,5,and 7 post epigastric pain.Using multiplex immunoassay panels,real-time polymerase chain reaction(qRT-PCR)arrays,and multicolour flow cytometry analysis,immune response-related proteins,genes,and cells were profiled respectively.GraphPad Prism^(TM) software and fold change(FC)analysis was used to determine differences between the groups.P<0.05 was considered significant.RESULTS The concentration of IL-6 was significantly different at D3 post epigastric pain in both the MAP group and MSAP group with P=0.001 and P=0.013 respectively,in a multiplex assay.When a FC of 2 was applied to identify differentially expressed genes using RT2 Profiler,CCR8 was shown to increase steadily with disease severity from MAP(1.33),MSAP(38.28)to SAP(1172.45)median FC.Further verification studies using RT-PCR showed fold change increases of CCR8 in MSAP and SAP ranging from 1000 to 1000000 times when represented as Log10,compared to healthy control respectively at D3.The findings also showed differing lymphocyte and monocyte cell frequency between the groups.With monocyte population frequency as high as 70%in MSAP at D3.CONCLUSION The higher levels of CCR8 and IL-6 in the severe patients and immune cell differences compared to MAP and controls provide an avenue for exploring AP stratification to improve management.

Therapeutic effect of Caspase-1 inhibitor on liver injury in experimental severe acute pancreatitis

Objective: To assess the therapeutic effect of Caspase-1 inhibitor on liver injury in experimental severe acute pancreatitis (SAP). Methods: Forty-two SD rats were randomly divided into 3 groups: healthy controls (HC, n=6); SAP-S group (n=18); SAP-ICE-I group (n=18). SAP was induced by retrograde infusion of 5% sodium taurocholate into the bili-pancreatic duct in SD rats. HC rats underwent same surgical procedures and duct cannulation without sodium taurocholate. In SAP-S group, rats received the first intraperitoneal injection of isotonic saline 2 h after induction of acute pancreatitis, which was repeated after 12 h. In SAP-ICE-I group, rats were firstly given ICE inhibitor intraperitoneally 2 h after induction of pancreatitis. As in SAP-S group, this was repeated at 12 h. Survied rats were killed at certain time points, and all samples were obtained for subsequent analysis. Results: The serum levels of ALT, AST and IL-1β in SAP-S group were (215.50±58.52)U/L, (372.17±38.05)U/L, (276.77±44.92)pg/ml at 6 h, (396.67±70.29)U/L, (548.50±75.29)U/L, (308.99±34.95)pg/ml at 12 h, (425.17±86.33)U/L, (665.83±84.05)U/L, (311.60±46.51)pg/ml, respectively, which were increased significantly (P<0.01, vs HC). In SAP-ICE-I group, their levels were decreased significantly (P<0.01, vs SAP-S). Intrahepatic expressions of Caspase-1, IL-1β and IL-18 mRNA could be observed in HC, which were increased significantly in SAP-S group (P<0.01, vs HC). The expressions of IL-1β and IL-18 mRNA were decreased significantly in SAP-ICE-I group (P<0.01, vs SAP-S), whereas Caspase-1 mRNA expressions had no significant differences (P>0.05). Caspase-1 inhibition had no effect on the severity of liver tissue damage. Conclusion: Caspase-1 activate cytokines, IL-1β and IL-18, play a pivotal role in the course of liver injury in SAP. Caspase-1 inhibitor can improve liver functions effectively.

血清IL-15、IL-18与急性胰腺炎预后的相关性研究

目的探讨血清IL-15、IL-18水平与急性胰腺炎预后的相关性。方法采用ELISA法分别测定正常对照组、轻型急性胰腺炎(mild acute pancreatitis,MAP)组及重症急性胰腺炎(severe acute pancreatitis,SAP)组第1、7、14天的IL-15、IL-18水平。结果 MAP组的血清IL-15、IL-18水平明显高于正常对照组(P<0.05),而SAP组的血清IL-15、IL-18水平较正常对照组升高更为明显(P<0.01);SAP组的血清IL-15、IL-18水平亦明显高于MAP组(P<0.05)。结论 IL-15、IL-18与急性胰腺炎严重程度密切相关,其血清水平可作为判断急性胰腺炎严重程度的指标之一。

Ischemic preconditioning inhibits development of edematous cerulein-induced pancreatitis: Involvement of cyclooxygenases and heat shock protein 70

AIM： To determine whether ischemic preconditioning （IP） affects the development of edematous cerulein-induced pancreatitis and to assess the role of cyclooxygenase-1 （COX-l）, COX-2, and heat shock protein 70 （HSP 70） in this process. METHODS： In male Wistar rats, IP was performed by damping of celiac artery （twice for 5 min at 5-min intervals）. Thirty minutes after IP or sham operation, acute pancreatitis was induced by cerulein. Activity of COX-1 or COX-2 was inhibited by resverabol or rofecoxib, respectively （10 rng/kg）. RESULTS： IP significantly reduced pancreatic damage in cerulein-induced pancreatitis as demonstrated by the improvement of pancreas histology, reduction in serum lipase and poly-C ribonuclease activity, and serum concentration of pro-inflammatory interleukin （IL）-1β. Also, IP attenuated the pancreatitis-evoked fall in pancreatic blood flow and pancreatic DNA synthesis. Serum level of anti-inflammatory IL-10 was not affected by IP. Cerulein-induced pancreatitis and IP increased the content of HSP 70 in the pancreas. Maximal increase in HSP 70 was observed when IP was combined with cerulein-induced pancreatitis. Inhibition of COXs, especially COX-2, reduced the protective effect of IP in edematous pancreatitis. CONCLUSION： Our results indicate that IP reducespancreatic damage in cerulein-induced pancreatitis and this effect, at least in part, depends on the activity of COXs and pancreatic production of HSP 70.