Secretagogue-induced pancreatitis in mice devoid of chymotrypsin.

The serine protease chymotrypsin protects the pancreas against pancreatitis by degrading trypsinogen, the precursor to the digestive protease trypsin. Taking advantage of previously generated mouse models with either the Ctrb1 gene (encoding chymotrypsin B1) or the Ctrl gene (encoding chymotrypsin-like protease) disrupted, here we generated the novel Ctrb1-del ×Ctrl-KO strain in the C57BL/6N genetic background, which harbors a naturally inactivated Ctrc gene (encoding chymotrypsin C). The newly created mice are devoid of chymotrypsin yet the animals develop normally, breed well, and show no spontaneous phenotype, indicating that chymotrypsin is dispensable under laboratory conditions. When given cerulein, the Ctrb1-del ×Ctrl-KO strain exhibited markedly increased intrapancreatic trypsin activation and more severe acute pancreatitis, relative to wild-type C57BL/6N mice. After the acute episode, Ctrb1-del ×Ctrl-KO mice spontaneously progressed to chronic pancreatitis while C57BL/6N mice recovered rapidly. The cerulein-induced pancreas pathology in Ctrb1-del ×Ctrl-KO mice was highly similar to that previously observed in Ctrb1-del mice, however, trypsin activation was more robust and pancreatitis severity was increased. Taken together, the results confirm and extend prior observations demonstrating that chymotrypsin safeguards the pancreas against pancreatitis by limiting pathologic trypsin activity. In mice, the CTRB1 isoform, which constitutes about 90% of the total chymotrypsin content, is responsible primarily for the anti-trypsin defenses and protection against pancreatitis, however, the minor isoform CTRL also contributes to an appreciable extent.

Total flavonoids of Chrysanthemum indicum L inhibit colonic barrier injury induced by acute pancreatitis by affecting gut microorganisms.

BACKGROUND: Acute pancreatitis (AP) is a prevalent acute abdominal condition, and AP induced colonic barrier dysfunction is commonly observed. Total flavonoids of Chrysanthemum indicum L (TFC) have exhibited noteworthy anti-inflammatory and anti-apoptotic properties. METHODS: We established AP models, both in animals and cell cultures, employing Cerulein. 16S rRNA gene sequencing was performed to investigate the gut microorganisms changes. RESULTS: In vivo, TFC demonstrated a remarkable capacity to ameliorate AP, as indicated by the inhibition of serum amylase, myeloperoxidase (MPO) levels, and the reduction in pancreatic tissue water content. Furthermore, TFC effectively curtailed the heightened inflammatory response. The dysfunction of colonic barrier induced by AP was suppressed by TFC. At the in vitro level, TFC treatment resulted in attenuation of increased cell apoptosis, and regulation of apoptosis related proteins expression in AR42J cells. The increase of Bacteroides sartorial, Lactobacillus reuteri, Muribaculum intestinale, and Parabacteroides merdae by AP, and decrease of of Helicobacter rodentium, Pasteurellaceae bacterium, Streptococcus hyointestinalis by AP were both reversed by TFC treatment. CONCLUSIONS: TFC can effectively suppress AP progression and AP induced colonic barrier dysfunction by mitigating elevated serum amylase, MPO levels, water content in pancreatic tissue, as well as curtailing inflammation, apoptosis. The findings presented herein shed light on the potential mechanisms by which TFC inhibit the development of AP progression and AP induced colonic barrier dysfunction.

NEMO/NF-κB signaling functions as a double-edged sword in PanIN formation versus progression to pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is marked by a dismal survival rate, lacking effective therapeutics due to its aggressive growth, late-stage diagnosis, and chemotherapy resistance. Despite debates on NF-κB targeting for PDAC treatment, no successful approach has emerged. METHODS: To elucidate the role of NF-κB, we ablated NF-κB essential modulator (NEMO), critical for conventional NF-κB signaling, in the pancreata of mice that develop precancerous lesions (KC mouse model). Secretagogue-induced pancreatitis by cerulein injections was utilized to promote inflammation and accelerate PDAC development. RESULTS: NEMO deletion reduced fibrosis and inflammation in young KC mice, resulting in fewer pancreatic intraepithelial neoplasias (PanINs) at later stages. Paradoxically, however, NEMO deletion accelerated the progression of these fewer PanINs to PDAC and reduced median lifespan. Further, analysis of tissue microarrays from human PDAC sections highlighted the correlation between reduced NEMO expression in neoplastic cells and poorer prognosis, supporting our observation in mice. Mechanistically, NEMO deletion impeded oncogene-induced senescence (OIS), which is normally active in low-grade PanINs. This blockage resulted in fewer senescence-associated secretory phenotype (SASP) factors, reducing inflammation. However, blocked OIS fostered replication stress and DNA damage accumulation which accelerated PanIN progression to PDAC. Finally, treatment with the DNA damage-inducing reagent etoposide resulted in elevated cell death in NEMO-ablated PDAC cells compared to their NEMO-competent counterparts, indicative of a synthetic lethality paradigm. CONCLUSIONS: NEMO exhibited both oncogenic and tumor-suppressive properties during PDAC development. Caution is suggested in therapeutic interventions targeting NF-κB, which may be detrimental during PanIN progression but beneficial post-PDAC development.

Heterozygous Spink1 Deficiency Promotes Trypsin-dependent Chronic Pancreatitis in Mice.

BACKGROUND & AIMS: Heterozygous SPINK1 mutations are strong risk factors for chronic pancreatitis in humans, yet heterozygous disruption of mouse Spink1 yielded no pancreatic phenotype. To resolve this contradiction, we used CRISPR/Cas9-mediated genome editing to generate heterozygous Spink1-deleted mice (Spink1-KOhet) in the C57BL/6N strain and studied the effect of this allele in trypsin-independent and trypsin-dependent pancreatitis models. METHODS: We investigated severity of acute pancreatitis and progression to chronic pancreatitis in Spink1-KOhet mice after transient (10 injections) and prolonged (2 × 8 injections) cerulein hyperstimulation. We crossed Spink1-KOhet mice with T7D23A and T7D22N,K24R mice that carry strongly autoactivating trypsinogen mutants and exhibit spontaneous chronic pancreatitis. RESULTS: Prolonged but not transient cerulein stimulation resulted in increased intrapancreatic trypsin activity and more severe acute pancreatitis in Spink1-KOhet mice relative to the C57BL/6N control strain. After the acute episode, Spink1-KOhet mice developed progressive disease with chronic pancreatitis-like features, whereas C57BL/6N mice recovered rapidly. Trypsinogen mutant mice carrying the Spink1-KOhet allele exhibited strikingly more severe chronic pancreatitis than the respective parent strains. CONCLUSIONS: Heterozygous Spink1 deficiency caused more severe acute pancreatitis after prolonged cerulein stimulation and promoted chronic pancreatitis after the cerulein-induced acute episode, and in two strains of trypsinogen mutant mice with spontaneous disease. In contrast, acute pancreatitis induced with limited cerulein hyperstimulation was unaffected by heterozygous Spink1 deletion, in agreement with recent observations that trypsin activity does not mediate pathologic responses in this model. Taken together, the findings strongly support the notion that loss-of-function SPINK1 mutations in humans increase chronic pancreatitis risk in a trypsin-dependent manner.

Activin A signaling stimulates neutrophil activation and macrophage migration in pancreatitis.

Acute Pancreatitis (AP) is associated with high mortality and current treatment options are limited to supportive care. We found that blockade of activin A (activin) in mice improves outcomes in two murine models of AP. To test the hypothesis that activin is produced early in response to pancreatitis and is maintained throughout disease progression to stimulate immune cells, we first performed digital spatial profiling (DSP) of human chronic pancreatitis (CP) patient tissue. Then, transwell migration assays using RAW264.7 mouse macrophages and qPCR analysis of "neutrophil-like" HL-60 cells were used for functional correlation. Immunofluorescence and western blots on cerulein-induced pancreatitis samples from pancreatic acinar cell-specific Kras knock-in (Ptf1aCreER™; LSL-KrasG12D) and functional WT Ptf1aCreER™ mouse lines mimicking AP and CP to allow for in vivo confirmation. Our data suggest activin promotes neutrophil and macrophage activation both in situ and in vitro, while pancreatic activin production is increased as early as 1 h in response to pancreatitis and is maintained throughout CP in vivo. Taken together, activin is produced early in response to pancreatitis and is maintained throughout disease progression to promote neutrophil and macrophage activation.

Metaplastic regeneration in the mouse stomach requires a reactive oxygen species pathway.

In pyloric metaplasia, mature gastric chief cells reprogram via an evolutionarily conserved process termed paligenosis to re-enter the cell cycle and become spasmolytic polypeptide-expressing metaplasia (SPEM) cells. Here, we use single-cell RNA sequencing (scRNA-seq) following injury to the murine stomach to analyze mechanisms governing paligenosis at high resolution. Injury causes induced reactive oxygen species (ROS) with coordinated changes in mitochondrial activity and cellular metabolism, requiring the transcriptional mitochondrial regulator Ppargc1a (Pgc1α) and ROS regulator Nf2el2 (Nrf2). Loss of the ROS and mitochondrial control in Ppargc1a-/- mice causes the death of paligenotic cells through ferroptosis. Blocking the cystine transporter SLC7A11(xCT), which is critical in lipid radical detoxification through glutathione peroxidase 4 (GPX4), also increases ferroptosis. Finally, we show that PGC1α-mediated ROS and mitochondrial changes also underlie the paligenosis of pancreatic acinar cells. Altogether, the results detail how metabolic and mitochondrial changes are necessary for injury response, regeneration, and metaplasia in the stomach.

SHCBP1 Overexpression Aggravates Pancreatitis by Triggering the Loss of Primary Cilia.

Primary cilia are microtubule-based organelles that mediate various biological processes. Pancreatic cells are typically ciliated; however, the role of primary cilia in acute pancreatitis (AP) is largely unknown. Here, we report that the loss of primary cilia, mediated by SHCBP1 (SHC1 binding protein), exerted a provocative effect on AP. Primary cilia are extensively lost in inflamed pancreatic cells in vitro and in mouse tissues with AP in vivo. Abrogation of primary cilia aggravated lipopolysaccharide (LPS)-induced inflammation in pancreatic cells. Mechanistically, AP induced the overexpression of SHCBP1 mitotic factor, which is localized to the base of primary cilia. SHCBP1 deficiency relieved LPS- and cerulein-induced pancreatitis by preventing the loss of primary cilia in vitro and in vivo. Collectively, we reveal that inflammation-induced loss of primary cilia aggravates AP. Furthermore, abrogating SHCBP1 to prevent primary cilia loss is an efficient strategy to combat AP.

Kidney morphology and renal expression of aquaporins 2, 3 and 4 during cerulein - Induced chronic pancreatitis in pigs.

PURPOSE: Chronic pancreatitis (CP) is associated with serious complications and reduced quality of life. Kidney failure is a frequent complication of acute pancreatitis (AP), however limited information is available regarding the impact of CP on this condition. In the kidney, 9 aquaporins (AQPs) are expressed to maintain body water homeostasis and concentrate urine. The purpose of this study was to morphologically assess and analyze the location and expression of AQP2, AQP3 and AQP4 and determine whether CP affects renal structure and expression of AQPs in collecting duct (CD) principal cells. MATERIALS/METHODS: CP was induced in domestic pigs through intramuscular injections of cerulein (1 â€‹µg/kg â€‹bw/day for 6 days; n â€‹= â€‹5); pigs without CP (n â€‹= â€‹5) were used as a control group. Kidney samples were collected 6 weeks after the last injection and subjected to histological examination. Expression of AQPs was determined by immunohistochemistry and Western blot. RESULTS: The kidneys of animals with CP exhibited moderate changes, including glomerular enlargement, increased collagen percentage, numerous stromal erythrorrhages and inflammatory infiltrations compared to control group. Although the total abundance of AQP2 in the CD decreased in pigs after cerulein administration, the difference was not statistically significant. Expression of AQP3 and AQP4 was limited to the basolateral membrane of the CD cells. AQP4 abundance remained relatively stable in both groups, while AQP3 expression increased nearly three-fold in pigs with CP. CONCLUSION: This study identified morphological alterations and a statistically significant increase in the expression of renal AQP3 when pigs developed CP.

Anti-inflammatory and anti-oxidant role of ursolic acid in cerulein-induced acute pancreatitis in rats.

BACKGROUND: Ursolic acid (UA) is found in many plants, and has been reported to have anti-protease, antioxidant, anti-inflammatory, antimicrobial, nephroprotective, hepatoprotective, and cardioprotective effects. OBJECTIVE: The purpose of this study was to investigate the effects of ursolic acid in cerulein-induced acute pancreatitis (AP). MATERIALS AND METHODS: Thirty-two Wistar albino rats were randomly assigned to 4 equal groups: Sham, acute pancreatitis, treatment, and ursolic acid group. RESULTS: Serum amylase levels in the AP and treatment groups were significantly higher than in the others (p < 0.05). In addition, serum IL-1ß, IL-6, and TNF-α levels were significantly higher in the AP group in comparison with the treatment group. Although pancreatic tissue total oxidant activity in the AP and treatment groups was similar, pancreatic tissue total antioxidant capacity was significantly higher in the treatment group than in the AP group. CONCLUSIONS: Damage to the pancreas and remote organs in AP was observed to be reduced by UA. In addition, oxidative stress was observed to be decreased by the effect of UA.

ANTECEDENTES: El ácido ursólico se encuentra en numerosas plantas y se ha informado que tiene efectos antiproteasas, antioxidantes, antiinflamatorios, antimicrobianos, nefroprotectores, hepatoprotectores y cardioprotectores. OBJETIVO: Este estudio tuvo como objetivo investigar los efectos del ácido ursólico en la pancreatitis aguda inducida por ceruleína. MATERIAL Y MÉTODOS: Treinta y dos ratas albinas Wistar fueron asignadas aleatoriamente a cuatro grupos iguales: grupo simulado, grupo de pancreatitis aguda, grupo de tratamiento y grupo de ácido ursólico. RESULTADOS: Los niveles de amilasa sérica en los grupos de pancreatitis aguda y de tratamiento fueron significativamente más altos que en los otros grupos (p < 0.05). Además, los niveles séricos de IL-1ß, IL-6 y TNF-α fueron significativamente más altos en el grupo de pancreatitis aguda en comparación con el grupo de tratamiento. Aunque la actividad oxidante total del tejido pancreático en ambos grupos fue similar, la capacidad antioxidante total del tejido pancreático en el grupo de tratamiento fue significativamente mayor. CONCLUSIÓN: Se observó que el ácido ursólico reduce el daño al páncreas y órganos remotos en la pancreatitis aguda, al igual que el estrés oxidativo.

Catechin hydrate ameliorates cerulein­induced chronic pancreatitis via the inactivation of TGF­ß/Smad2 signaling.

Chronic pancreatitis (CP) is a pancreatic inflammatory disease associated with histological changes, including fibrosis, acinar cell loss and immune cell infiltration, and leads to damage of the pancreas, which results in pain, weight loss and loss of pancreas function. Catechin or catechin hydrate (CH) has antioxidant, anticancer and immune­regulatory effects. However, unlike other catechins, the antifibrotic effects of (+)­CH have not been widely studied in many diseases, including CP. Therefore, the anti­fibrotic effects of (+)­CH against CP were evaluated in the present study. To assess the prophylactic effects of CH, (+)­CH (1, 5 or 10 mg/kg) or ethanol was administered 1 h before first cerulein (50 µg/kg) injection. To assess the therapeutic effects, (+)­CH (5 mg/kg) or ethanol was administered after cerulein injection for one or two weeks. In both methods, cerulein was injected intraperitoneally into mice once every hour, six times a day, four times a week, for a total of three weeks, to induce CP. The data showed that (+)­CH markedly inhibited glandular destruction and inflammation during CP. Moreover, (+)­CH prevented pancreatic stellate cell (PSC) activation and the production of extracellular matrix components, such as fibronectin 1 and collagens, which suggested that it may act as a novel therapeutic agent. Furthermore, the mechanism and effectiveness of (+)­CH on pancreatic fibrosis were investigated in isolated PSCs. (+)­CH suppressed the activation of Smad2 and fibrosis factors that act through transforming growth factor­ß (TGF­ß) or platelet­derived growth factor. These findings suggest that (+)­CH exhibits antifibrotic effects in cerulein­induced CP by inactivating TGF­ß/Smad2 signaling.

Función antiinflamatoria y antioxidante del ácido ursólico en la pancreatitis aguda inducida por ceruleína en ratas / Anti-inflammatory and anti-oxidant role of ursolic acid in cerulein-induced acute pancreatitis in rats

Resumen Antecedentes: El ácido ursólico se encuentra en numerosas plantas y se ha informado que tiene efectos antiproteasas, antioxidantes, antiinflamatorios, antimicrobianos, nefroprotectores, hepatoprotectores y cardioprotectores. Objetivo: Este estudio tuvo como objetivo investigar los efectos del ácido ursólico en la pancreatitis aguda inducida por ceruleína. Material y métodos: Treinta y dos ratas albinas Wistar fueron asignadas aleatoriamente a cuatro grupos iguales: grupo simulado, grupo de pancreatitis aguda, grupo de tratamiento y grupo de ácido ursólico. Resultados: Los niveles de amilasa sérica en los grupos de pancreatitis aguda y de tratamiento fueron significativamente más altos que en los otros grupos (p < 0.05). Además, los niveles séricos de IL-1β, IL-6 y TNF-α fueron significativamente más altos en el grupo de pancreatitis aguda en comparación con el grupo de tratamiento. Aunque la actividad oxidante total del tejido pancreático en ambos grupos fue similar, la capacidad antioxidante total del tejido pancreático en el grupo de tratamiento fue significativamente mayor. Conclusión: Se observó que el ácido ursólico reduce el daño al páncreas y órganos remotos en la pancreatitis aguda, al igual que el estrés oxidativo.

Abstract Background: Ursolic acid (UA) is found in many plants, and has been reported to have anti-protease, antioxidant, anti-inflammatory, antimicrobial, nephroprotective, hepatoprotective, and cardioprotective effects. Objective: The purpose of this study was to investigate the effects of ursolic acid in cerulein-induced acute pancreatitis (AP). Materials and methods: Thirty-two Wistar albino rats were randomly assigned to 4 equal groups: Sham, acute pancreatitis, treatment, and ursolic acid group. Results: Serum amylase levels in the AP and treatment groups were significantly higher than in the others (p < 0.05). In addition, serum IL-1β, IL-6, and TNF-α levels were significantly higher in the AP group in comparison with the treatment group. Although pancreatic tissue total oxidant activity in the AP and treatment groups was similar, pancreatic tissue total antioxidant capacity was significantly higher in the treatment group than in the AP group. Conclusions: Damage to the pancreas and remote organs in AP was observed to be reduced by UA. In addition, oxidative stress was observed to be decreased by the effect of UA.

Repetitive Cerulein-Induced Chronic Pancreatitis in Growing Pigs-A Pilot Study.

Chronic pancreatitis (CP) is an irreversible and progressive inflammatory disease. Knowledge on the development and progression of CP is limited. The goal of the study was to define the serum profile of pro-inflammatory cytokines and the cell antioxidant defense system (superoxidase dismutase-SOD, and reduced glutathione-GSH) over time in a cerulein-induced CP model and explore the impact of these changes on selected cytokines in the intestinal mucosa and pancreatic tissue, as well as on selected serum biochemical parameters. The mRNA expression of CLDN1 and CDH1 genes, and levels of Claudin-1 and E-cadherin, proteins of gut barrier, in the intestinal mucosa were determined via western blot analysis. The study showed moderate pathomorphological changes in the pigs' pancreas 43 days after the last cerulein injection. Blood serum levels of interleukin (IL)-1-beta, IL-6, tumor necrosis factor alpha (TNF-alpha), C-reactive protein (CRP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGTP), SOD and GSH were increased following cerulein injections. IL-1-beta, IL-6, TNF-alpha and GSH were also increased in jejunal mucosa and pancreatic tissue. In duodenum, decreased mRNA expression of CDH1 and level of E-cadherin and increased D-lactate, an indicator of leaky gut, indicating an inflammatory state, were observed. Based on the current results, we can conclude that repetitive cerulein injections in growing pigs not only led to CP over time, but also induced inflammation in the intestine. As a result of the inflammation, the intestinal barrier was impaired.

Phospholipase D2 targeted by miR-5132-5p alleviates cerulein-induced acute pancreatitis via the Nrf2/NFκB pathway.

BACKGROUND: Acute pancreatitis (AP) is an inflammatory process unexpectedly occurring in the pancreas, imposing a substantial burden on healthcare systems. Herein, we aimed to clarify the mechanism of action of phospholipase D2 (PLD2) in cerulein-treated AR42J cells, affording valuable insights into the treatment of AP. METHODS: The levels of PLD2, miR-5132-5p, inflammatory factors (interleukin [IL]-10, IL-6, and tumor necrosis factor-α), caspase-3 activity, and apoptosis-related proteins (Bax and Bcl-2) in cerulein-treated AR42J cells were detected using reverse transcription-quantitative polymerase chain, caspase-3 activity, and Western blot analysis. Protein levels of nuclear Factor erythroid 2-Related Factor 2 (Nrf2) and nuclear factor-k-gene binding (NF-κB) were detected by Western blot analysis. TargetScan predicted upstream microRNAs (miRNAs) of PLD2, and the interaction between miR-5132-5p and PLD2 was verified using a luciferase assay. RESULTS: In cerulein-treated AR42J cells, PLD2 levels were downregulated, while miR-5132-5p expression was upregulated. Overexpression of PLD2 attenuated the cerulein-mediated facilitatory effect on inflammation and apoptosis in AR42J cells by regulating the Nrf2/NFκB pathway. Luciferase reporter analysis revealed that miR-5132-5p targeted PLD2, and miR-5132-5p negatively regulated PLD2. Upregulation of miR-5132-5p expression exacerbated inflammation and apoptosis and reversed the protective effect of PLD2 overexpression on AP. CONCLUSION: PLD2 targeted by miR-5132-5p can attenuate cerulein-induced AP in AR42J cells via the Nrf2/NFκB pathway, providing therapeutic targets for patients with AP.

Mouse model of PRSS1 p.R122H-related hereditary pancreatitis highlights context-dependent effect of autolysis-site mutation.

Mutation p.R122H in human cationic trypsinogen (PRSS1) is the most frequently identified cause of hereditary pancreatitis. The mutation blocks protective degradation of trypsinogen by chymotrypsin C (CTRC), which involves an obligatory trypsin-mediated cleavage at Arg122. Previously, we found that C57BL/6N mice are naturally deficient in CTRC, and trypsinogen degradation is catalyzed by chymotrypsin B1 (CTRB1). Here, we used biochemical experiments to demonstrate that the cognate p.R123H mutation in mouse cationic trypsinogen (isoform T7) only partially prevented CTRB1-mediated degradation. We generated a novel C57BL/6N mouse strain harboring the p.R123H mutation in the native T7 trypsinogen locus. T7R123H mice developed no spontaneous pancreatitis, and severity parameters of cerulein-induced pancreatitis trended only slightly higher than those of C57BL/6N mice. However, when treated with cerulein for 2 days, more edema and higher trypsin activity was seen in the pancreas of T7R123H mice compared to C57BL/6N controls. Furthermore, about 40% of T7R123H mice progressed to atrophic pancreatitis in 3 days, whereas C57BL/6N animals showed full histological recovery. Taken together, the observations indicate that mutation p.R123H inefficiently blocks chymotrypsin-mediated degradation of mouse cationic trypsinogen, and modestly increases cerulein-induced intrapancreatic trypsin activity and pancreatitis severity. The findings support the notion that the pathogenic effect of the PRSS1 p.R122H mutation in hereditary pancreatitis is dependent on its ability to defuse chymotrypsin-dependent defenses.

Total flavonoids of Chrysanthemum indicum L inhibit acute pancreatitis through suppressing apoptosis and inflammation.

Acute pancreatitis (AP) is one of the most common acute abdomen. Inflammation and apoptosis are closely linked with AP development. Total flavonoids of Chrysanthemum indicum L (TFC) has been proved to inhibit inflammation and apoptosis. If TFC could suppress AP remains unclear. AP animal and cell models were established with Cerulein. The pancreatic tissue injury was measured with HE staining. Inflammatory factors were detected with ELISA method. The protein expression was evaluated with Western blotting. Inhibition of AP in vivo was achieved by TFC by inhibiting serum amylase, myeloperoxidase (MPO), and water content of pancreatic tissue. The increased inflammatory response and activation of NF-κB signaling pathway in AP rats were inhibited after TFC treatment. The activation of NF-κB signaling pathway, increase of cell apoptosis and inflammatory factors in AR42J cells were suppressed by TFC. We demonstrated that TFC could significantly inhibit AP through restraining serum amylase, MPO, water content of pancreatic tissue, inflammation levels, apoptosis, and NF-κB signaling pathway activation. This study might clarify the potential inhibition mechanism of TFC in AP development.

Development and Characterization of Novel Chronic Eosinophilic Inflammation- Mediated Murine Model of Malignant Pancreatitis.

AIMS: Develop a novel murine models of malignant pancreatitis. BACKGROUND: Although patients with chronic pancreatitis are at a greater risk of developing pancreatic cancer, there is no definitive mouse model that currently develops chronic pancreatitis-induced pancreatic cancer. OBJECTIVE: Characterization of eosinophilic inflammation-mediated malignant pancreatitis in novel murine model. METHODS: We developed a murine model of chronic eosinophilic inflammation associated with pancreatitis that also shows characteristic features of pancreatic malignancy. The mouse received cerulein and azoxymethane via intraperitoneal administration developed pathological malignant phenotype, as well as concomitant lung inflammation. RESULTS: We discovered pathological alterations in the pancreas that were associated with chronic pancreatitis, including a buildup of eosinophilic inflammation. Eosinophil degranulation was reported nearby in the pancreas tissue sections that show acinar-to-ductal metaplasia and acinar cell atrophy, both of which are characteristic of pancreatic malignancies. Additionally, we also observed the formation of PanIN lesions after three initial doses of AOM and eight weeks of cerulein with the AOM treatment regimen. We discovered that persistent pancreatic eosinophilic inflammation linked with a pancreatic malignant phenotype contributes to pulmonary damage. The RNA seq analysis also confirmed the induction of fibro-inflammatory and oncogenic proteins in pancreas and lung tissues. Further, in the current manuscript, we now report the stepwise kinetically time-dependent cellular inflammation, genes and proteins involved in the development of pancreatitis malignancy and associated acute lung injury by analyzing the mice of 3 AOM with 3, 8, and 12 weeks of the cerulein challenged protocol regime. CONCLUSION: We first show that sustained long-term eosinophilic inflammation induces time-dependent proinflammatory, profibrotic and malignancy-associated genes that promote pancreatic malignancy and acute lung injury in mice.

Arecae pericarpium water extract alleviates chronic pancreatitis by deactivating pancreatic stellate cells.

Chronic pancreatitis (CP) is a chronic inflammatory disease of the pancreas with irreversible morphological changes. Arecae pericarpium (ARP), known to improve gastrointestinal disorders, has not yet been reported to inhibit fibrosis in CP. Therefore, we investigated the beneficial effects of ARP on cerulein-induced CP. Cerulein (50 µg/kg) was administered intraperitoneally to mice every hour, six times a day, four times a week for a total of 3 weeks to induce CP. To ascertain the prophylactic effects of ARP, ARP water extract (50, 100, or 200 mg/kg) or saline was administered intraperitoneally 1 h before the onset of CP. To determine the therapeutic effects of ARP, ARP water extract (200 mg/kg) or saline was administered for a total of 1 week or 2 weeks, starting 2 weeks or 1 week after the onset of CP. The pancreas was collected immediately for histological analysis. Additionally, to determine the effectiveness and mechanism of ARP in alleviating pancreatic fibrosis, pancreatic stellate cells (PSCs) were isolated. ARP treatment considerably improved glandular atrophy and inflammation and repressed collagen deposition in the pancreas. Furthermore, ARP water extract inhibited extracellular matrix (ECM) constituents such as alpha-smooth muscle actin (α-SMA), collagen I, and fibronectin 1 (FN1) in pancreatic tissue and PSCs. ARP also suppressed transforming growth factor-ß (TGF-ß) signaling by inhibiting Smad2 phosphorylation. Our study suggests that ARP exhibits anti-fibrotic effects in cerulein-induced CP by inhibiting TGF-ß/Smad signaling.

Lutein inhibits IL­6 expression by inducing PPAR­Î³ activation and SOCS3 expression in cerulein­stimulated pancreatic acinar cells.

Acute pancreatitis is a severe inflammatory disease of the pancreas. In experimental acute pancreatitis, cerulein induces the expression of interleukin­6 (IL­6) by activating Janus kinase (JAK) 2/signal transducer and activator of transcription (STAT) 3 in pancreatic acinar cells. Ligands of peroxisome proliferator activated receptor­Î³ (PPAR­Î³) and suppressor of cytokine signaling (SOCS) 3 inhibit IL­6 expression by suppressing JAK2/STAT3 in cerulein­stimulated pancreatic acinar AR42J cells. Lutein, an oxygenated carotenoid, upregulates and activates PPAR­Î³ to regulate inflammation in a renal injury model. The present study aimed to determine whether lutein activated PPAR­Î³ and induced SOCS3 expression in unstimulated AR42J cells, and whether lutein inhibited activation of JAK2/STAT3 and IL­6 expression via activation of PPAR­Î³ and SOCS3 expression in cerulein­stimulated AR42J cells. The anti­inflammatory mechanism of lutein was determined using reverse transcription­quantitative PCR, western blot analysis and enzyme­linked immunosorbent assay in AR42J cells stimulated with or without cerulein. In another experiment, cells were treated with lutein and the PPAR­Î³ antagonist GW9662 or the PPAR­Î³ agonist troglitazone prior to cerulein stimulation to determine the involvement of PPAR­Î³ activation. The results indicated that lutein increased PPAR­Î³ and SOCS3 levels in unstimulated cells. Cerulein increased phospho­specific forms of JAK2 and STAT3, and mRNA and protein expression of IL­6, but decreased SOCS3 levels in AR42J cells. Cerulein­induced alterations were suppressed by lutein or troglitazone. GW9662 alleviated the inhibitory effect of lutein on JAK2/STAT3 activation and IL­6 expression in cerulein­stimulated cells. In conclusion, lutein inhibited the activation of JAK2/STAT3 and reduced IL­6 levels via PPAR­Î³­mediated SOCS3 expression in pancreatic acinar cells stimulated with cerulein.

SWIP-a stabilized window for intravital imaging of the murine pancreas.

Pancreatitis and pancreatic ductal adenocarcinoma (PDAC) are grave illnesses with high levels of morbidity and mortality. Intravital imaging (IVI) is a powerful technique for visualizing physiological processes in both health and disease. However, the application of IVI to the murine pancreas presents significant challenges, as it is a deep, compliant, visceral organ that is difficult to access, easily damaged and susceptible to motion artefacts. Existing imaging windows for stabilizing the pancreas during IVI have unfortunately shown poor stability for time-lapsed imaging on the minutes to hours scale, or are unable to accommodate both the healthy and tumour-bearing pancreata. To address these issues, we developed an improved stabilized window for intravital imaging of the pancreas (SWIP), which can be applied to not only the healthy pancreas but also to solid tumours like PDAC. Here, we validate the SWIP and use it to visualize a variety of processes for the first time, including (1) single-cell dynamics within the healthy pancreas, (2) transformation from healthy pancreas to acute pancreatitis induced by cerulein, and (3) the physiology of PDAC in both autochthonous and orthotopically injected models. SWIP can not only improve the imaging stability but also expand the application of IVI in both benign and malignant pancreas diseases.

Activity of acute pancreatitis is modified by secreted protein acidic and rich in cysteine ablation.

BACKGROUND: Acute pancreatitis (AP) is a frequent cause for hospitalization. However, molecular determinants that modulate severity of experimental pancreatitis are only partially understood. OBJECTIVE: To investigate the role of secreted protein acidic and rich in cysteine (SPARC) during cerulein-induced AP in mice. METHODS: AP was induced by repeated cerulein injections in SPARC knock-out mice (SPARC-/- ) and control littermates (SPARC+/+ ). Secreted protein acidic and rich in cysteine expression and severity of AP were determined by histopathological scoring, immunohistochemistry, and biochemical assays. For functional analysis, primary murine acinar cell cultures with subsequent amylase release assays were employed. Proteome profiler assay and ELISA were conducted from pancreatic tissue lysates, and co-immunofluorescence was performed. RESULTS: Upon cerulein induction, SPARC expression was robustly induced in pancreatic stellate cells (PSCs) but not in acinar cells. Genetic SPARC ablation resulted in attenuated severity of AP with significantly reduced levels of pancreatic necrosis, apoptosis, immune cell infiltration, and reduced fibrosis upon chronic stimulation. However, the release of amylase upon cerulein stimulation in primary acinar cell culture from SPARC+/+ and SPARC-/- was indistinguishable. Notably, immune cell derived C-C Motif Chemokine Ligand 2 (CCL2) was highly elevated in SPARC+/+ pancreatic tissue potentially linking PSC derived SPARC with CCL2 induction in AP. CONCLUSION: SPARC mediates the severity of AP. The potential link between SPARC and the CCL2 axis could open new avenues for tailored therapeutic interventions in AP patients and warrants further investigations.