Experimental Acute Pancreatitis Research Articles

Azithromycin does not improve disease severity in acute experimental pancreatitis.

Acute pancreatitis is a severe systemic disease triggered by a sterile inflammation and initial local tissue damage of the pancreas. Immune cells infiltrating into the pancreas are main mediators of acute pancreatitis pathogenesis. In addition to their antimicrobial potency, macrolides possess anti-inflammatory and immunomodulatory properties which are routinely used in patients with chronic airway infections and might also beneficial in the treatment of acute lung injury. We here tested the hypothesis that the macrolide antibiotic azithromycin can improve the course of acute experimental pancreatitis via ameliorating the damage imposed by sterile inflammation, and could be used as a disease specific therapy. However, our data show that azithromycin does not have influence on caerulein induced acute pancreatitis in terms of reduction of organ damage, and disease severity. Furthermore Infiltration of immune cells into the pancreas or the lungs was not attenuated by azithromycin as compared to controls or ampicillin treated animals with acute experimental pancreatitis. We conclude that in the chosen model, azithromycin does not have any beneficial effects and that its immunomodulatory properties cannot be used to decrease disease severity in the model of caerulein-induced pancreatitis in mice.

Clostridium butyricum Strains Suppress Experimental Acute Pancreatitis by Maintaining Intestinal Homeostasis.

Acute pancreatitis (AP) is a common abdominal inflammatory disease. Disturbed gut homeostasis secondary to pancreatic inflammation aggravates the condition retroactively. The current study investigates potential beneficial effects of Clostridium butyricum (C. butyricum) strains on AP and underlying mechanisms. C. butyricum strains MIYAIRI 588 (CBM588) and CGMCC0313.1 (CB0313.1) were supplemented to mice for three weeks before experimental AP or SAP induction. Both CBM588 and CB0313.1 protected against AP, as evidenced by reduced serum amylase and lipase levels, pancreatic edema, and myeloperoxidase activity. Amelioration of both experimental AP and SAP by CB0313.1 indicated a non-model-specific effect. Moreover, C. butyricum inhibited pancreatic neutrophil and dendritic cell infiltration, nucleotide-binding domain leucine-rich repeat-containing family, pyrin domain-containing 3 inflammasome activation, and pro-inflammatory pathways. Additionally in the gut, C. butyricum strains attenuated AP-associated intestinal inflammation and barrier dysfunction, accompanied with reduced pathogenic bacteria Escherichia coli and Enterococcus penetration into pancreas. Gut microbiome analyses further revealed that beneficial effects of C. butyricum on pancreatic-gut homeostasis were correlated with improved dysbiosis. In particular, relative abundance of Desulfovibrionaceae decreased, and Verrucomicrobiaceae Clostridiaceae and Lactobacillaceae increased. For the first time, a protective effect of C. butyricum in AP by modulating intestinal homeostasis is demonstrated.

Deletion of Galectin-3 attenuates acute pancreatitis in mice by affecting activation of innate inflammatory cells.

Acute pancreatitis is characterized by autodigestion of pancreatic cells followed by acute inflammation leading to pathology and death. In experimental acute pancreatitis, pancreatic acinar cells and infiltrating macrophages express Galectin-3 but its role in pathology of this disease is unknown. Therefore, we studied its role using Galectin-3 deficient mice. Deletion of Galectin-3 prolonged the survival of mice, led to attenuation of histopathology, and decreased infiltration of mononuclear cells and neutrophils that express TLR-4, in particular, pro-inflammatory N1 neutrophils. Galectin-3 and TLR-4 are also colocalized on infiltrating cells. Lack of Galectin-3 reduced expression of pro-inflammatory TNF-α and IL-1β in F4/80+ CD11c- and CD11c+ F4/80- cells. Thus, deletion of Galectin-3 ameliorates acute pancreatitis by attenuating early influx of neutrophils and inflammatory mononuclear cells of innate immunity. These findings provide the basis to consider Galectin-3 as a therapeutic target in acute pancreatitis.

Recent Insights Into the Pathogenic Mechanism of Pancreatitis: Role of Acinar Cell Organelle Disorders.

Acute pancreatitis (AP) is a potentially lethal inflammatory disease that lacks specific therapy. Damaged pancreatic acinar cells are believed to be the site of AP initiation. The primary function of these cells is the synthesis, storage, and export of digestive enzymes. Beginning in the endoplasmic reticulum and ending with secretion of proteins stored in zymogen granules, distinct pancreatic organelles use ATP produced by mitochondria to move and modify nascent proteins through sequential vesicular compartments. Compartment-specific accessory proteins concentrate cargo and promote vesicular budding, targeting, and fusion. The autophagy-lysosomal-endosomal pathways maintain acinar cell homeostasis by removing damaged/dysfunctional organelles and recycling cell constituents for substrate and energy. Here, we discuss studies in experimental and genetic AP models, primarily from our groups, which show that acinar cell injury is mediated by distinct mechanisms of organelle dysfunction involved in protein synthesis and trafficking, secretion, energy generation, and autophagy. These early AP events (often first manifest by abnormal cytosolic Ca signaling) in the acinar cell trigger the inflammatory and cell death responses of pancreatitis. Manifestations of acinar cell organelle disorders are also prominent in human pancreatitis. Our findings suggest that targeting specific mediators of organelle dysfunction could reduce disease severity.

Yttrium oxide nanoparticles reduce the severity of acute pancreatitis caused by cerulein hyperstimulation

Oxidative stress plays a major role in acute pancreatitis (AP), leading to massive macrophage infiltration. Nanoyttria (NY) possesses potent free radical scavenging activity. As reactive oxygen species and inflammation play major role in AP, we hypothesized that NY may alleviate cerulein induced AP. NY ameliorated LPS induced oxidative stress in vitro. It reduced ROS, superoxide radical generation and restored the mitochondrial membrane potential in macrophages. Interestingly, NY reduced plasma amylase and lipase levels and attenuated the mitochondrial stress and inflammatory markers. NY suppressed the recruitment of inflammatory cells around the damaged pancreatic acinar cells. Furthermore, NY intervention perturbed the course of AP via reduction of endoplasmic reticulum (ER) stress markers (BiP, IRE1 and Ero1-Lα), and molecular chaperones (Hsp27 and Hsp70). We, to the best of our knowledge, report for first time that NY can attenuate experimental AP by restoration of mitochondrial and ER homeostasis through Nrf2/NFκB pathway modulation.

Protection of acute renal injury in severe experimental acute pancreatitis

Background: Acute renal failure is a serious early complication in patients with acute pancreatitis (AP) significantly increases mortality rates. Thus, it is essential to protect renal function in patients with severe AP. Methods: Acute necrotizing pancreatitis was induced by L-ornithine in 26 Wistar rats. 16 rats served as control. We administered enoxaparin in 10 rats after induction of acute pancreatitis during 5 days. The effect of enoxaparin was evaluated by determining the levels of serum amylase, creatinine, hydrogen sulfide, and fibrinogen, time of recalcification, activity of NO-synthase and myeloperoxidase (MPO) in pancreas. Results: The concentration of creatinine in serum is increase at 86.86%. It was noticed that the level of creatinine significantly directly correlated with the concentration of MPO and activity of iNOS in the pancreas, amylase in serum blood, and reverse with the concentration of H2S in serum. Renal failure in rats was accompanied by a hypercoagulation, determined by probable direct correlation between the levels of creatinine and fibrinogen, inverse relationship between creatinine concentrations and plasma recalcification time. Enoxaparin ameliorates morphology of the pancreas and kidney. The enoxaparin normalized serum creatinine, fibrinogen, amylase, MPO, H2S, decreased activity of iNOS. Conclusion: Enoxaparin in experimental AP reduces morphological signs of damage in the pancreas and kidneys, the intensity nitrosative stress and inflammation, normalizes hemostasis.

Protection of acute renal injury in severe experimental acute pancreatitis

Background: Acute renal failure is a serious early complication in patients with acute pancreatitis (AP) significantly increases mortality rates. Thus, it is essential to protect renal function in patients with severe AP. Methods: Acute necrotizing pancreatitis was induced by L-ornithine in 26 Wistar rats. 16 rats served as control. We administered enoxaparin in 10 rats after induction of acute pancreatitis during 5 days. The effect of enoxaparin was evaluated by determining the levels of serum amylase, creatinine, hydrogen sulfide, and fibrinogen, time of recalcification, activity of NO-synthase and myeloperoxidase (MPO) in pancreas. Results: The concentration of creatinine in serum is increase at 86.86%. It was noticed that the level of creatinine significantly directly correlated with the concentration of MPO and activity of iNOS in the pancreas, amylase in serum blood, and reverse with the concentration of H2S in serum. Renal failure in rats was accompanied by a hypercoagulation, determined by probable direct correlation between the levels of creatinine and fibrinogen, inverse relationship between creatinine concentrations and plasma recalcification time. Enoxaparin ameliorates morphology of the pancreas and kidney. The enoxaparin normalized serum creatinine, fibrinogen, amylase, MPO, H2S, decreased activity of iNOS. Conclusion: Enoxaparin in experimental AP reduces morphological signs of damage in the pancreas and kidneys, the intensity nitrosative stress and inflammation, normalizes hemostasis.

Examination of protective and therapeutic effects of ruscogenin on cerulein-induced experimental acute pancreatitis in rats.

PurposeTo determine the potential protective and therapeutic effects and action mechanism of ruscogenin on cerulein-induced acute pancreatitis (AP) model in rats.MethodsOverall, 32 rats were attenuated to the sham (2-mL/kg/day isotonic solution for 4 weeks), control (20-µg/kg cerulein-induced AP for 12 hours), prophylaxis groups (cerulein-induced AP following 3-mL/kg/day ruscogenin for 4 weeks) and treatment (3-mL/kg/day ruscogenin following cerulein-induced AP for 12 hours). Blood samples were collected for biochemical analysis of nitric oxide synthase 1 (NOS1/neuronal NOS), malondialdehyde (MDA) and intercellular adhesion molecule 1 (ICAM-1). After sacrification, pancreas tissues were collected and prepared for light microscopic (hematoxylin and eosin), immunohistochemical (nuclear factor kappa B) and biochemical analysis (tumor necrosis factor-alpha [TNF-α], interleukin-6 and 1β [IL-6 and IL-1β], CRP, high-sensitivity CRP [hs-CRP] amylase, lipase, and ICAM-1). Ultrastructural analysis was performed by transmission electron microscopy.ResultsThe protective and therapeutic actions of ruscogenin were accomplished by improvements in histopathology, by decreasing blood cytokine levels of CRP, hs-CRP levels, TNF-α, IL-6, IL-1β, ICAM-1, by reducing the pancreatic enzymes amylase and lipase in blood, and by suppressing the expression of nuclear factor kappa B, ICAM-1, and NOS-1, but not MDA in pancreatic tissues. Ruscogenin also improved cerulein-induced ultrastructural degenerations in endocrine and exocrine cells, especially in treatment group.ConclusionThe present findings have demonstrated the beneficial protective and therapeutical effects of ruscogenin, nominating it as a highly promising supplementary agent to be considered in the treatment of AP, and even as a protective agent against the damages induced by disease.

The effects of a TNF-alpha inhibitor and HBO combination on the severity of pancreatitis and oxidative response in an experimental model of acute pancreatitis.

We aimed to investigate the effects of infliximab and HBO (hyperbaric oxygen) used alone or in combination on oxidative stress and the severity of pancreatitis in an experimental model of AP (acute pancreatitis). A total of 60 rats were randomly divided into five groups. Group 1 underwent laparotomy; Group 2 underwent experimental AP; Group 3 was given an infliximab infusion and underwent AP; Group 4 was subjected to HBO therapy after AP; and Group 5 was given infliximab infusion before AP and subjected to HBO therapy. Serum amylase, superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GPX) levels in the pancreas tissues were measured. The pancreatic tissue samples were scored. There were statistically significant differences in the histopathological scores and amylase levels between non-treated AP and all the three treatment groups. Group 5 had the closest histopathological scores to the sham group. MDA levels were significantly different between non-treated AP and all the three treatment groups, but the SOD levels and GPX values were not. Combination of HBO therapy and Infliximab showed a synergistic effect on the reduction of histopathological severity and mortality in acute pancreatitis. All treatment modalities reduced the pathological findings by decreasing lipid peroxidation and partly increasing the antioxidant capacity in early period (Tab. 1, Fig. 3, Ref. 28).

Фармакологическая коррекция метаболических нарушений при экспериментальном остром панкреатите на фоне хронической алкогольной интоксикации

Фармакологическая коррекция метаболических нарушений при экспериментальном остром панкреатите на фоне хронической алкогольной интоксикации

Genistein protects against acute pancreatitis via activation of an apoptotic pathway mediated through endoplasmic reticulum stress in rats

Acute pancreatitis (AP) is a severe and frequently lethal disorder, but the precise mechanisms are not well understood and there is lack of effective drugs. Therefore, our study examined the in vivo intervention effects of genistein and elucidated its mechanism in acute experimental pancreatitis models. We used cerulein or taurocholate to induce acute pancreatitis (AP) in Sprague-Dawley rats with prior genistein treatment. Histological examination of the pancreas was performed and the expression of unfolded protein response (UPR) components and apoptotic mediators like caspase 12 and c-Jun N-terminal protein kinase (JNK) were measured. The amount of apoptosis in pancreatic acinar cells was also determined. Our studies found that the severity of cerulein- or taurocholate-induced AP was rescued by prior genistein treatment. Genistein stimulated the activation of multiple endoplasmic reticulum (ER) stress-related regulators like GRP78, PERK, eIF2α, and upregulated the expression of the apoptotic genes, caspase 12 and CHOP. Moreover, TUNEL assays showed that genistein treatment promoted acinar cell apoptosis. Taken together, we speculated that ER stress-associated apoptotic pathways in AP are induced by genistein, which showed cytoprotective capacity in the exocrine pancreas. These data suggest novel therapeutic strategies that employ genistein in the prevention of AP.

Endoscopic Ultrasound-Guided Fine-Needle Injection of Hydrogen Peroxide into the Pancreas: Feasibility and Tolerability Study Using a Survival Porcine Model

Hydrogen peroxide (H2O2) has been reported to be an effective radiation sensitizer for various cancers. A combination therapy comprising fine-needle injection (FNI) of H2O2 under endoscopic ultrasound (EUS) guidance and chemoradiation might improve treatment outcomes of pancreatic cancer; however, there have been no reports thus far. The aims of this study were to evaluate the feasibility and safety of EUS-FNI of H2O2 into the pancreas using a porcine survival model. EUS-FNI was performed in the pancreas of six pigs, which were randomly divided into three groups based on the solution injected: group 1, 2 mL of sodium hyaluronate (control); group 2, 0.5 mL of H2O2; group 3, 2 mL of H2O2. To evaluate any adverse events, blood tests and computed tomography (CT) were performed before and after FNI, as well as days 3 and 7 subsequently. The pigs were necropsied on day 7. Histologic evaluation was performed according to the criteria for experimental acute pancreatitis. EUS-FNI was successful in all pigs. CT immediately after FNI revealed gas formation in the FNI area in groups 2 and 3. No adverse events were revealed by blood tests and CT. Histologic evaluations revealed pancreatitis scores of 5 and 5 in group 1, 7 and 7 in group 2 and 14 and 15 in group 3. EUS-FNI of H2O2 into the pancreas is feasible; however, it could cause pancreatitis. FNI of H2O2 into only the pancreatic tumor might be ideal in minimizing possible adverse events.

Pharmacological correction of metabolic disorders in experimental acute pancreatitis on the background of chronic alcohol intoxication

Introduction. Acute pancreatitis and pre-existing diseases (chronic alcohol intoxication) are challenging issues of modern surgery in terms of frequency of deaths and the number of complications.
 Objective. To identify the best combination of immunomodulators, antioxidants and hepatoprotectors to correct immunometabolic disorders in acute destructive pancreatitis on the background of chronic alcohol intoxication (CAI).
 Materials and methods. Studies were conducted on 377 healthy adult Wistar rats weighing 150-200 g. Alcohol intoxication was modeled by forced intragastric administration of a 20% ethanol solution at a dose of 3 ml/kg or 2.92 g/kg at 24 hours for 5 days, 30 days (CAI-30) or 60 days (CAI-60). Acute destructive pancreatitis (ADP) was modeled after R.N. Wang et al. (1995), modified by S.A. Alekhin et al. (2006). The efficacy of combining Hepon (5 mg/kg, orally, at 24 hours, No. 14), Hypoxen (750 mg/kg, orally, at 24 hours, No. 14), Phosphogliv (800 mg/kg, orally, at 24 hours, No. 14), Glutoxim (20 mg/kg, intramuscularly, at 24 hours, No. 5), Mexidol (50 mg/kg, intraperitoneally, at 24 hours, No. 14) and Heptral (760 mg/kg, intraperitoneally, at 24 hours , No. 5) was examined in animals with ADP on the background of CAI-30 and CAI-60.
 Results and discussion. Different degrees of ethanol intoxication depending on time leads to the development of an impaired capacity of hepatocytes, as well as immune and metabolic disorders. The administration of Phosphogliv, Hypoxen and Hepon in case of CAI-30+ADP normalizes 12.1% and corrects 60.6% of the changed values. The combination of Heptral, Glutoxim and Mexidol normalizes 57.8% and corrects 42.4% of the values. In case of CAI-60+ADP, Phosphogliv, Hypoxen and Hepon normalizes 11.8% and corrects 38.2% of the values. The combination of Heptral, Glutoxim and Mexidol normalizes 17.6% and corrects 67.6% of the values, respectively.
 Conclusion. In case of ADP along with CAI-30 and CAI-60, the combination of Heptral, Glutoxim and Mexidol is more preferable than that of Phosphogliv, Hypoxen and Hepon.

Fluid resuscitation via the rectum ameliorates hemodynamic disorders through adjusting aquaporin expression in an experimental severe acute pancreatitis model

Acute pancreatitis is an acute abdominal disease, with 10-20% of the cases deteriorating rapidly, accompanied by persistent organ failure and further development into severe acute pancreatitis (SAP). The aim of the present study was to investigate the mechanism of fluid resuscitation via the rectum in the early stages of SAP and the role of aquaporins (AQPs). An SAP model was constructed by injection of 5% sterile sodium taurocholate into the biliopancreatic duct of Sprague Dawley rats, and the mean arterial pressure (MAP) was continuously monitored via femoral artery catheterization. At 30 min after the construction of the SAP model, the rats in the fluid resuscitation groups were resuscitated with normal saline at a rate of 4 ml/kg/h through the venous or the rectal route. The AQP and Na+-K+-ATPase levels, and the correlation of the MAP and colon AQPs at the early stages of SAP were analyzed. The results demonstrated that the mRNA level of AQP-3 and AQP-4 in the distal colon decreased significantly in the group subjected to fluid resuscitation via the rectum, while no significant differences were identified in the Na+-K+-ATPase levels of the colon in that group. Furthermore, a negative correlation was identified between the expression of AQPs and the MAP (P<0.01). Thus, fluid resuscitation via the rectum appears to ameliorate hemodynamic disorders through adjusting the expression of AQP-3 and AQP-4 in the distal colon in an experimental SAP model.

Induction of Pancreatic Inflammation Accelerates Pancreatic Tumorigenesis in Mice.

Pancreatitis is a major risk factor for the development of pancreatic cancer. In genetically engineered mouse models, induction of pancreatic inflammation dramatically accelerates oncogenic KRas-induced fibrosis, precancerous PanIN formation, and tumorigenesis. Here we describe simple methods of secretagogue-induced experimental acute and chronic pancreatitis, the most commonly used pancreatitis models, and their applications in pancreatic cancer research. Additionally, the preparation of primary pancreatic acinar cells is introduced. Primary acinar cells can be used to study the early events of pancreatic inflammation and pancreatic acinar-to-ductal (ADM) metaplasia.

A Novel Derivative of the Natural Product Danshensu Suppresses Inflammatory Responses to Alleviate Caerulein-Induced Acute Pancreatitis.

Acute pancreatitis (AP), a common abdominal inflammatory disorder, is characterized by premature intracellular activation of digestive proteases within pancreatic acini and a consecutive systemic inflammatory response. Although the mechanism remains to be fully understood, inflammation is the main cause of pancreatic damage in AP. A novel compound [4-(2-acetoxy-3-((R)-3-(benzylthio)-1-methoxy-1-oxopropan-2-ylamino)-3-oxopropyl)-1,2-phenylene diacetate (DSC)], derived from danshensu, exhibits anti-inflammatory and anti-apoptotic properties in vitro. However, its potential beneficial effect in AP has not been demonstrated. This study aimed to investigate the effects and underlying mechanisms of DSC in experimental AP in mice. We found that DSC suppressed inflammatory responses in AP by inhibiting the activation of nuclear factor-κB (NF-κB), signal transducer and activator of transcription 3 (STAT3) and nucleotide-binding domain leucine-rich repeat containing family, pyrin domain-containing 3 (NLRP3) inflammasome. Furthermore, treatment with DSC modulated the infiltration of neutrophils and the phenotypes of macrophages in mice induced with AP. Interestingly, we found that the expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) and its regulated antioxidant enzyme heme oxygenase-1 (HO-1), which modulate inflammatory activities, was significantly increased in DSC-treated groups. Together, our findings demonstrate that DSC alleviates pancreatic inflammation and damage in AP by inhibiting the activation of NF-κB, STAT3, and NLRP3 inflammasome and modulating immune cell responses.

Thoracic epidural anaesthesia reduces insulin resistance and inflammatory response in experimental acute pancreatitis

Aims: The activity of the sympathetic nervous system (SNS) is crucial at an early stage in the development of an inflammatory reaction. A study of metabolic events globally and locally in the early phase of acute pancreatitis (AP), implying hampered SNS activity, is lacking.We hypothesized that thoracic epidural anaesthesia (TEA) modulates the inflammatory response and alleviates the severity of AP in pigs.Material and methods: The taurocholate (TC) group (n = 8) had only TC AP. The TC + TEA group (n = 8) had AP and TEA. A control group (n = 8) underwent all the preparations, without having AP or TEA. Metabolic changes in the pancreas were evaluated by microdialysis and by histopathological examination.Results: The relative increase in serum lipase concentrations was more pronounced in the TC group than in TC + TEA and control groups. A decrease in relative tissue oxygen tension (PtiO2) levels occurred one hour later in the TC + TEA group than in the TC group. The maintenance of normoglycaemia in the TC group required a higher glucose infusion rate than in the TC + TEA group. The relative decrease in serum insulin concentrations was most pronounced in the TC + TEA group.Conclusion: TEA attenuates the development of AP, as indicated by changes observed in haemodynamic parameters and by the easier maintenance of glucose homeostasis. Further, TEA was associated with attenuated insulin resistance and fewer local pathophysiological events.

Experimental acute pancreatitis is enhanced in mice with tissue nonspecific alkaline phoshatase haplodeficiency due to modulation of neutrophils and acinar cells

Tissue nonspecific alkaline phosphatase (TNAP) has a well established role in bone homeostasis and in hepatic/biliary conditions. In addition, TNAP is expressed in the inflamed intestine and is relevant to T and B lymphocyte function. TNAP KO mice are only viable for a few days, but TNAP+/− haplodeficient mice are viable. Acute pancreatitis was induced by repeated caerulein injection in WT and TNAP+/− mice. TNAP+/− mice presented an increased expression of Cxcl2, Ccl2, Selplg (P-selectin ligand), Il6 and Il1b in the pancreas. Freshly isolated acinar cells showed a dramatic upregulation of Cxcl1, Cxcl2, Ccl2, Il6, Selpg or Bax in both pancreatitis groups. TNAP+/− cells displayed a 2-fold higher expression of Cxcl2, and a smaller increase in Il6. These findings could be partly replicated by in vitro treatment of primary acinar cells with caerulein. Furthermore, the proinflammatory effect on acinar cells could be partially reproduced in wild type cells treated with the TNAP inhibitor levamisole. TNAP mRNA levels were also markedly upregulated by pancreatitis in acinar cells. Neutrophil infiltration (MRP8+ cells) and activation (IL-6 and TNF production in LPS treated primary neutrophils) were increased in TNAP+/− vs WT mice. Neutrophil depletion greatly attenuated inflammation, indicating that this cell type is mainly responsible for the higher inflammatory status of TNAP+/− mice. In conclusion, our results show that altered TNAP expression results in heightened pancreatic inflammation, which may be explained by an augmented response of neutrophils and by a higher sensitivity of acinar cells to caerulein injury.

RCAN1 is a marker of oxidative stress, induced in acute pancreatitis

BackgroundTo date, there still is a lack of specific acute pancreatitis markers and specifically an early marker that can reliably predict disease severity. The inflammatory response in acute pancreatitis is mediated in part through oxidative stress and calcineurin-NFAT (Nuclear Factor of Activated T-cells) signaling, which is inducing its own negative regulator, regulator of calcineurin 1 (RCAN1). Caerulein induction is a commonly used in vivo model of experimental acute pancreatitis. Caerulein induces CN-NFAT signaling, reactive oxygen species and inflammation. MethodsTo screen for potential markers of acute pancreatitis, we used the caerulein model of experimental acute pancreatitis (AP) in C57Bl/6 J mice. Pancreata from treated and control mice were used for expression profiling. Promising gene candidates were validated in cell culture experiments using primary murine acinar cells and rat AR42J cells. These candidates were then further tested for their usefulness as biomarkers in mouse and human plasma. ResultsWe identified a number of novel genes, including Regulator of calcineurin 1 (Rcan1) and Sestrin 2 (Sesn2) and demonstrated that they are induced by oxidative stress, by stimulation with H2O2 and by inhibiting caerulein stimulated expression with the antioxidant N-acetylcysteine. We found Rcan1 protein to be significantly elevated in AP-induced mouse plasma as well as in plasma from AP patients. ConclusionWe demonstrated that Rcan1 is regulated by oxidative stress and identified RCAN1 as a potential diagnostic marker of AP.

Resolvin D1 Resolve Inflammation in Experimental Acute Pancreatitis by Restoring Autophagic Flux.

Acute pancreatitis (AP) is a common acute gastrointestinal disorders. Increasing evidence indicated that autophagy is involved in the development of AP. Resolvin D1 is an endogenous pro-resolving lipid mediator, which can protect mice from cerulein-induced acute pancreatitis and facilitate autophagy in macrophage, but its mechanism remians unclear. To investigate the effect of resolvin D1 on autophagy in mouse models of cerulein-induced AP. C57BL/6 mice were randomly divided into control group, AP group and resolvin D1 group. The models of cerulein-induced AP were constructed by intraperitoneally cerulein. Resolvin D1 group was established by intraperitoneally resolvin D1 based on AP models, simultaneously, control group received normal saline. The severity of AP, the level of inflammatory cytokines, the number of autophagic vacuoles, and the expression of autophagy-related markers were evaluated among three groups. The AP models were established successfully. Compared to control group, the number of autophagic vacuoles and expressions of autophagy-related markers including Beclin-1, p62 and LC3-II were increased in AP models, In contrast, the degree of inflammation and levels of inflammatory cytokines in AP models were reduced after resolvin D1 treatment. Moreover, resolvin D1 attenuated the number of autophagic vacuoles and expressions of autophagy-related markers. Autophagic flux is impaired in cerulein-induced AP. Resolvin D1 ameliorate the severity of mice with cerulein-induced acute pancreatitis, possible attributing to its reducing impaired autophagy and restoring autophagic flux.