Induction Of Acute Pancreatitis Research Articles

Abstract C072: Bmi1 expression is upregulated in response to injury/stress in the pancreas

Abstract Pancreatic homeostasis is regulated in part through epigenetic mechanisms that restrict or enable access of pancreatic lineage transcription factors to their target genes. These epigenetic protein cascades are also required for regeneration of the pancreas after injury. B-cell Moloney murine leukemia virus integration site 1 (Bmi1), a central protein in the Polycomb repressor complex 1 (PRC1), has been shown to be required for the regeneration of the pancreas after injury and its absence prevents pancreatic neoplasia in mice. Previous work also suggests that Bmi1 marks a subset of acinar cells contributing to pancreatic renewal and tissue maintenance. It remains unclear how Bmi1 expression levels are regulated in response to pancreatic stress and injury. Here we assess the baseline expression of Bmi1 in pancreatic tissue with a genetic reporter mouse model as well as changes in Bmi1 mRNA levels at different time points after the induction of pancreatitis in wild-type mice via RNA in situ hybridization (RNAscope). We also compare the ability of the murine pancreas to regenerate after acute pancreatitis in the presence and absence of Bmi1. Our data indicates that rather than a specific subpopulation, most, if not all, acinar cells in the pancreas express Bmi1 during their life and specific loss of Bmi1 in the pancreas impairs regeneration after acute pancreatitis. We also show an increase in Bmi1 mRNA levels within the pancreas shortly after the induction of acute pancreatitis which reduces as the pancreas resumes its normal histology. Altogether, our data indicate that Bmi1 expression is dynamic, responsive to injury and necessary for pancreatic homeostasis and regeneration. Citation Format: Nur Muhammad Renollet, Joyce K Thompson, Emily Wu, Osama Alkhalili, Nina Steele, Filip Bednar. Bmi1 expression is upregulated in response to injury/stress in the pancreas [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C072.

Abstract C064: Mapping cellular plasticity through the lens of FRA1 during Kras G12D mediated pancreatic acinar to ductal metaplasia

Abstract Introduction: Acinar cells have been proposed as a cell-of-origin for pancreatic ductal adenocarcinoma (PDAC) after undergoing acinar to ductal metaplasia (ADM). ADM can be triggered by pancreatitis causing acinar cells to de-differentiate to a ductal-like state. We identify FRA1 (gene name Fosl1) as the most active transcription factor during Kras G12D acute pancreatitis-mediated injury. Herein, we explore the role of the FRA1 in the onset of ADM and neoplastic transformation. Methods: We generated tamoxifen (TAM)-inducible Ptf1aCre ERT ;Kras G12D ; Rosa26 YFP/YFP (TAM-KCY Fosl1 WT ) mice and bred in the Fosl1 fl/fl allele to create TAM- KCY Fosl1 KO mice and subjected them to caerulin (CCK analog) induced acute pancreatitis. First, we performed a time course of hematoxylin and eosin (H&E) images from mice either with Fosl1 WT or Fosl1 KO after induction of acute pancreatitis to understand the functional role of FRA1 during acinar de-differentiation. Next, after snap-freezing pancreata at the Day 5 post-caerulein timepoint and extracting nuclei, we sorted YFP+ nuclei for snATAC sequencing and bulk-RNA sequencing. We developed a pseudotime model and gene-regulatory network (GRN) to understand the dynamic landscape as cells transitioned from normal acinar to late ADM. Finally, to determine the functional role of in tumorigenesis, we bred an inducible mutant p53 R172H gain- of-function allele into TAM-KCY Fosl1 WT/KO mice to create TAM-KPCY Fosl1 WT/KO mice. These mice were subjected to the same tamoxifen and acute pancreatitis protocol as TAM-KCY Fosl1 WT/KO mice and monitored for tumor growth and overall survival. Results: A time course of H&E images demonstrated that FRA1 depletion slowed progression to maximum ADM in the first 5 days after caerulein treatment. We additionally observed a dramatic reduction in the amount of PanIN lesions formed between TAM-KCY Fosl1 WT and TAM-KCY Fosl KO mice, which occurred on day 7 in this caerulein model. Pseudotime analysis proposed a time point when FRA1 becomes active to prime ADM cells for recovery from inflammation and simultaneously undergo PanIN transformation. Furthermore, GRN analysis validated the differentially active transcription factors identified by pseudotime analysis of snATAC-seq. To elaborate on further timepoints, we observed a delay in the progression of TAM-KCY Fosl KO PanIN lesions at later Day 21, 8-week and 12-week timepoints. In the survival analysis, TAM-KPCY Fosl1 WT mice had a median survival time of 25.86 weeks, while TAM-KPCY Fosl1 KO mice survived for almost twice as long with a median survival time of 40.57 weeks. Histologically, the percentage of Ki-67- positive cells in TAM-KPCY Fosl1 WT tumors was significantly higher than in TAM-KPCY Fosl1 KO tumors, suggesting the loss of FRA1 reduce tumor aggressiveness. Conclusions: Our findings reveal that FRA1 is a critical mediator of ADM progression to PanIN and PDAC. Fosl1 genetic depletion can alter the kinetics of ADM formation and lead to a decrease in PanIN and eventual malignant transformation. Citation Format: Alina Li, Noriyuki Nishiwaki, Kensuke Sugiura, Kensuke Suzuki, Constanza Nicole Tapia Contreras, Dorsay Sadeghian, Anirban Maitra, Jason R Pitarresi, Rohit Chandwani, Peter A Sims, Anil K Rustgi. Mapping cellular plasticity through the lens of FRA1 during Kras G12D mediated pancreatic acinar to ductal metaplasia [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C064.

A rapid protocol for inducing acute pancreatitis in zebrafish models

Acute pancreatitis (AP) is an inflammatory disorder that occurs in the exocrine pancreas associated with tissue injury and necrosis. Experimental models of AP typically involve rodents, such as rats or mice. However, rodents exhibit divergent pathophysiological responses after the establishment of AP between themselves and in comparison, with human. The experiments conducted for this manuscript aimed to standardize a new AP model in zebrafish and validate it. Here, we provide a protocol for inducing AP in zebrafish through intraperitoneal injections of synthetic caerulein. Details are provided for solution preparation, pre-injection procedures, injection technique, and monitoring animal survival. Subsequently, validation was performed through biochemical and histological analyses of pancreatic tissue. The administered dose of caerulein for AP induction was 10 μg/kg applied four times in the intraperitoneal region. The histological validation study demonstrated the presence of necrosis within the first 12 h post-injection, accompanied by an excess of zymogen granules in the extracellular milieu. These observations align with those reported in conventional rodent models. We have standardized and validated the AP model in zebrafish. This model can contribute to preclinical and clinical studies of new drugs for AP treatment. Therefore, this novel model expands the toolkit for exploring faster and more effective preventive and therapeutic strategies for AP.

Algal Oil Mitigates Sodium Taurocholate-Induced Pancreatitis by Alleviating Calcium Overload, Oxidative Stress, and NF-κB Activation in Pancreatic Acinar Cells.

Acute pancreatitis (AP) is characterized by elevated intracellular Ca2+ concentrations, mitochondrial dysfunction, and oxidative stress in pancreatic acinar cells. Algal oil (AO) has demonstrated antioxidant and anti-inflammatory properties. This study aims to explore the effects of algal oil on the microenvironment of AP. Rat pancreatic acinar AR42J cells were pretreated with AO containing 0, 50, 100, or 150 μM of docosahexaenoic acid (DHA) 2 h prior to AP induction using sodium taurocholate (STC). After 1 h of STC treatment, AR42J cells exhibited a significant increase in intracellular Ca2+ concentration and the production of amylase, lipase, reactive oxygen species, and pro-inflammatory mediators, including tumor necrosis factor-α and interleukin-6. These STC-induced increases were markedly reduced in cells pretreated with AO. In comparison to cells without AO, those treated with a high dose of AO before STC exposure demonstrated a significant increase in mitochondrial membrane potential and a decrease in lipid peroxidation. Furthermore, STC-activated nuclear factor kappa-B (NF-κB) was attenuated in AO-pretreated cells, as evidenced by a significant decrease in activated NF-κB. In conclusion, AO may prevent damage to pancreatic acinar cells by alleviating intracellular Ca2+ overload, mitigating mitochondrial dysfunction, reducing oxidative stress, and attenuating NF-κB-targeted inflammation.

Liproxstatin-1 attenuates acute hypertriglyceridemic pancreatitis through inhibiting ferroptosis in rats

Ferroptosis is closely associated with inflammatory diseases, including acute pancreatitis (AP); however, the involvement of ferroptosis in hypertriglyceridemic pancreatitis (HTGP) remains unclear. In the present study, we aimed to explore the relationship between lipid metabolism and ferroptosis in HTGP and the alleviating effect of liproxstatin-1 (Lip-1) in vivo. This study represents the first exploration of lipid metabolism and endoplasmic reticulum stress (ERS) in HTGP, targeting ferroptosis as a key factor in HTGP. Hypertriglyceridemia (HTG) was induced under high-fat diet conditions. Cerulein was then injected to establish AP and HTGP models. Lip-1, a specific ferroptosis inhibitor, was administered before the induction of AP and HTGP in rats, respectively. Serum triglyceride, amylase, inflammatory factors, pathological and ultrastructural structures, lipid peroxidation, and iron overload indicators related to ferroptosis were tested. Moreover, the interaction between ferroptosis and ERS was assessed. We found HTG can exacerbate the development of AP, with an increased inflammatory response and intensified ferroptosis process. Lip-1 treatment can attenuate pancreatic injury by inhibiting ferroptosis through lipid metabolism and further resisting activations of ERS-related proteins. Totally, our results proved lipid metabolism can promote ferroptosis in HTGP by regulating ACSL4/LPCAT3 protein levels. Additionally, ERS may participate in ferroptosis via the Bip/p-EIF2α/CHOP pathway, followed by the alleviating effect of Lip-1 in the rat model.

Buprenorphine affects the initiation and severity of interleukin-induced acute pancreatitis in mice.

Acute pancreatitis (AP) is a common disease with no targeted therapy and has varied outcomes ranging from spontaneous resolution to being lethal. Although typically painful, AP can also be painless. Various agents, including opioids, are used for pain control in AP; the risks and benefits of which are often debated. As experimental AP in mice is used to study the efficacy of potential therapies, we studied the effect of a commonly used opioid, buprenorphine, on the initiation and progression of AP. For this, we administered extended-release buprenorphine subcutaneously before inducing the previously established severe AP model that uses interleukins 12 and 18 (IL12,18) in genetically obese (ob/ob) mice and compared this to mice with AP but without the drug. Mice were monitored over 3 days, and parameters of AP induction and progression were compared. Buprenorphine significantly reduced serum amylase, lipase, pancreatic necrosis, and AP-associated fat necrosis, which is ubiquitous in obese mice and humans. Buprenorphine delayed the AP-associated reduction of carotid artery pulse distention and the development of hypothermia, hastened renal injury, and muted the early increase in respiratory rate versus IL12,18 alone. The site of buprenorphine injection appeared erythematous, inflamed, and microscopically showed thinning, loss of epidermal layers that had increased apoptosis. In summary, subcutaneous extended-release buprenorphine interfered with the induction of AP by reducing serum amylase, lipase, pancreatic and fat necrosis, the worsening of AP by delaying hypotension, hypothermia, while hastening renal injury, respiratory depression, and causing cutaneous injury at the site of injection.NEW & NOTEWORTHY Extended-release buprenorphine interferes with the initiation and progression of acute pancreatitis at multiple levels.

Recurrent acute pancreatitis in a patient with peanut allergy

Peanut allergy is a common food allergy. Accidental peanut exposure can induce anaphylactic symptoms in allergic individuals. In rare cases, pancreatitis can be induced by food allergies. This report describes a 12-year-old girl with recurrent acute pancreatitis (AP) following a peanut allergy induced 8 years after the first episode. The patient experienced the first episode of AP at 4 years old when she accidentally consumed peanut powder ice cream. AP was recurrently induced 8 years later by an oral food challenge test with a small amount of peanuts, despite decreased specific IgE for peanuts and Arah2. This report is the first to demonstrate that AP, as a peanut-induced symptom, is difficult to tolerate over a long period in a patient with peanut allergy. The possibility of AP induction after accidental ingestion, oral food challenge, or oral immunotherapy for peanuts should be considered in patients with peanut allergy.

FASTING INCREASES THE SEVERITY OF ACUTE PANCREATITIS IN A MOUSE MODEL: IMPLICATIONS FOR PREOPERATIVE INTERVENTIONS TO REDUCE COMPLICATIONS OF PANCREATIC SURGERY.

Acute pancreatitis following surgical or endoscopic procedures on the pancreas can compromise the outcome and lead to severe complications and even death. The aim of this study was to determine whether prolonged fasting affects the severity of acute pancreatitis (AP). Male mice were divided into 4 groups: Group CF (n=5) control animals that fasted for 24 hours; Group CNF (n=5) control animals that did not fast; Group APF (n=7) that fasted for 24 hours and underwent induction of acute pancreatitis (AP) and Group APNF (n=7) that did not fast and underwent AP. Eight hours after AP blood was collected for evaluation of cytokines: IL-1β, IL-6, IL-10, TNF-α and MCP-1. Liver tissue was collected for determination of Malondialdehyde, pancreatic tissue for determination of enzyme content and lung tissue for determination of myeloperoxidase. Significant increase in pancreatic amylase content was observed in group CF and increased serum levels of IL -6, Il-10 and MCP-1 were in group APF. Liver malondialdehyde was also increased in APF animals. APF group showed much more necrosis of the pancreatic acinar cells. In the present study, we observed an increase in the severity of acute pancreatitis with prolonged fasting in a severe acute pancreatitis model. These results suggest that in clinical practice, the preoperative fasting time should be shortened before pancreatic procedures.

Eugenol Reduced ΜPO, CD45 and HMGB1 Expression and Attenuated the Expression of Leukocyte Infiltration Markers in the Intestinal Tissue in Biliopancreatic Duct Ligation-Induced Pancreatitis in Rats.

Background and Objectives: Inflammation and dysregulation in the intestinal barrier function in acute pancreatitis (AP) trigger pancreatic lesions, systemic inflammatory response, and multiple organ dysfunction. Eugenol, as the main component of clove (Syzygium aromaticum), is known for its antioxidant and anti-inflammatory properties. We studied the potentially beneficial effect of eugenol in a rodent model of biliopancreatic duct ligation-induced AP. Materials and Methods: Rats were randomly divided into three groups: Sham, AP, and AP + eugenol (15 mg/kg/day). Serum TNFα, IL-6, IL-18, and resistin levels, as well as IL-6, TNFα, MPO, HMGB1, and CD45 tissue expression, were determined at various timepoints after the induction of AP. Results: Eugenol attenuated hyperemia and inflammatory cell infiltration in the intestinal mucosal, submucosal, and muscular layers. IL-6 and resistin serum levels were significantly reduced in the AP + eugenol group, while serum TNFα and IL-18 levels remained unaffected overall. TNFα pancreatic and intestinal expression was attenuated by eugenol at 72 h, while IL-6 expression was affected only in the pancreas. MPO, CD45, and HMGB1 intestinal expression was significantly reduced in eugenol-treated rats. Conclusions: Eugenol managed to attenuate the inflammatory response in the intestine in duct ligation-induced AP in rats.

Healing effect of warfarin in the course of cerulein-induced acute pancreatitis in rats.

Acute pancreatitis (AP) is the most common gastrointestinal disease leading to hospitalizations and unexpected deaths. The development of AP leads to damage of the pancreatic microcirculation with a cascade of subsequent events resulting, among others, in coagulopathy. Previous research showed that anticoagulants can be important therapeutic agents. Heparin and acenocoumarol can alleviate the course of AP, as well as accelerate healing and post-inflammatory regeneration of the pancreas. The aim of this study was to determine whether warfarin, a drug with more stable effects than acenocoumarol, affects the healing and regeneration of the pancreas in the cerulein-induced AP. AP was evoked in Wistar male rats by intraperitoneal administration of cerulein. The first dose of warfarin (45, 90 or 180 μg/kg) was administered 24 hours after the first dose of cerulein and the doses of warfarin were repeated once a day in subsequent 10 days. The severity of AP was assessed immediately after the last dose of cerulein, as well as at days 1, 2, 3, 5, and 10 after AP induction. Treatment with warfarin dose-dependently increased international normalized ratio (INR) and attenuated the severity of pancreatitis in histological examination and accelerated pancreatic recovery. These effects were accompanied with a faster reduction in the AP-evoked increase in serum activity of amylase and lipase, the serum concentration of pro-inflammatory interleukin-1β, and the plasma level of D-Dimer. In addition, treatment with warfarin decreased pancreatic weight (an index of pancreatic edema) and improved pancreatic blood flow in rats with AP. The therapeutic effect was particularly pronounced after the administration of warfarin at a dose of 90 μg/kg. We conclude that treatment with warfarin accelerated regeneration of the pancreas and recovery in the course of cerulein-induced mild-edematous acute pancreatitis.

Administration of Warfarin Inhibits the Development of Cerulein-Induced Edematous Acute Pancreatitis in Rats.

Acute pancreatitis (AP) is a severe disease with high morbidity and mortality in which inflammation and coagulation play crucial roles. The development of inflammation leads to vascular injury, endothelium and leukocytes stimulation, and an increased level of tissue factor, which results in the activation of the coagulation process. For this reason, anticoagulants may be considered as a therapeutic option in AP. Previous studies have shown that pretreatment with heparin, low-molecular-weight heparin (LMWH), or acenocoumarol inhibits the development of AP. The aim of the present study was to check if pretreatment with warfarin affects the development of edematous pancreatitis evoked by cerulein. Warfarin (90, 180, or 270 µg/kg/dose) or saline were administered intragastrically once a day for 7 days consecutively before the induction of AP. AP was evoked by the intraperitoneal administration of cerulein. The pre-administration of warfarin at doses of 90 or 180 µg/kg/dose reduced the histological signs of pancreatic damage in animals with the induction of AP. Additionally, other parameters of AP, such as an increase in the serum activity of lipase and amylase, the plasma concentration of D-dimer, and interleukin-1β, were decreased. In addition, pretreatment with warfarin administered at doses of 90 or 180 µg/kg/dose reversed the limitation of pancreatic blood flow evoked by AP development. Warfarin administered at a dose of 270 µg/kg/dose did not exhibit a preventive effect in cerulein-induced AP. Conclusion: Pretreatment with low doses of warfarin inhibits the development of AP evoked by the intraperitoneal administration of cerulein.

Vitamin E ameliorates oxidative stress in the stomach of l-arginine induced acute pancreatitis rat model

Gut dysfunction is a major outcome during acute pancreatitis (AP). Some studies have reported a positive association between acute pancreatitis and peptic ulcer. The major cause of peptic ulcer is due to ischaemia reperfusion leading to oxidative stress. This study assessed the oxidative status of the stomach during AP and the role of vitamin (Vit.) E administration. Twenty male Wistar rats were divided randomly into 4 groups; Control, Vit. E (500 mg/kg) only, AP and Vit. E + AP. Acute pancreatitis was induced by administering four doses of l-arginine (100 mg/100 g) intraperitoneally at 1-hour interval. The rats were sacrificed 72 hours later and stomach obtained for mucin content and biochemical assays (MDA, MPO, NO, CAT, GST, and GSH). Mucin content was depleted following AP induction while, vit. E significantly increase mucin content. AP resulted in significant reduction of antioxidant enzymes (GSH and GST) and increase in oxidative stress markers (MDA, MPO and NO). Vitamin E reverse these changes. In conclusion, the oxidative status of the stomach was greatly altered following AP induction with an increase in oxidative stress markers and decrease in antioxidants. Vitamin E was able to protect the stomach from the damaging effect of acute pancreatitis.

Functioning of whole bone marrow cell population in a model of L-arginine-induced pancreatitis

Objective The present study aimed to investigate the metabolic activity and adherence capacity of the whole bone marrow cell (wBMC) population and changes in bone marrow (BM) architecture after acute pancreatitis (AP) induction. Methods The disease was induced by injecting L-arginine (350 mg/100 g; i.p.). The control animals, animals injected with L-arginine, and animals pre-treated with allopurinol were included in this study. Serum and routine pathohistological analysis were conducted to confirm the induction of AP. The metabolic activity and adherence capacity of wBMC were evaluated in the MTT assay and methylene-blue test, respectively, and the alterations in pancreatic tissue and BM were examined on histological sections. In addition, immunohistochemical expression of β-catenin was assessed in the pancreatic tissue. Results The wBMC adherence capacity and their total number significantly increased after AP induction. The adherence capability of wBMC was reduced in rats pre-treated with allopurinol. There were no statistically significant changes in the metabolic activity of wBMCs. In the BM isolated from AP and allopurinol pre-treated animals, a discrete left shift in granulocytopoiesis was found, with a slight increase in the myeloid-to-erythroid ratio. Conclusions After AP induction, it was shown that wBMCs expressed increased adherence capacity and unchanged metabolic activity, while the alterations in BM may reflect the general activation of myelopoiesis, which would agree with the increased mobilization of mesenchymal stem cells. Also, a significant decrease in β-catenin expression in the pancreatic tissue was noticed.

Changes in the biochemical parameters of blood and the morphological structure of the pancreas in rats with acute pancreatitis and their correction using corvitin

Acute pancreatitis (AP) is an inflammation of the pancreas characterized by a severe course and a high mortality rate. The pathogenesis of AP is still not fully understood, so there is currently a lack of treatment. Corvitin is a water-soluble form of quercetin that retains all the properties of quercetin and has powerful antioxidant, anti-inflammatory and anti-apoptotic properties. The aim of our study was to evaluate the effect of corvitin on biochemical blood parameters and morphological features of the pancreas in rats with AP caused by intraperitoneal administration of L-arginine (200 mg/100 g). This model of AP is non-invasive, highly reproducible and causes selective, dose-dependent necrosis of acinar cells and is ideal both for studying the pathomechanisms of AP and for observing and influencing changes in the course of the disease. The legality of using this model is confirmed by the morphostructural changes in the pancreas that are characteristic of AP. In rats with AP, an increase in the blood concentration of α-amylase (twice), alanine aminotransferase (ALT) (three times), aspartate aminotransferase (AST) (one and a half times) compared to control values was observed already on the first day of the pathology development. On the second day of AP, the level of glucose and urea in the blood of rats increased by 34 and 22%, respectively, while the creatinine content did not change. Under the influence of corvitin (50 mg/kg), the levels of α-amylase, ALT and glucose decreased already after a day, while the content of AST and urea increased and remained so until the 8th day of observation. The most positive dynamics of morphological changes in the pancreas of rats was observed when corvitin was used on the first day of AP induction.

Effects of probiotics on pancreatic inflammation and intestinal integrity in mice with acute pancreatitis

BackgroundSevere acute pancreatitis is a potentially life-threatening disease. Despite being a common disorder, acute pancreatitis lacks a specific treatment. The present study aimed to examine the effects of probiotics on pancreatic inflammation and intestinal integrity in mice with acute pancreatitis.MethodsMale ICR mice were randomly divided into 4 groups (n = 6 per group). The control group received two intraperitoneal (i.p.) injections of normal saline as a vehicle control. The acute pancreatitis (AP) group received two i.p. injections of L-arginine 450 mg/100 g body weight. AP plus probiotics groups received L-arginine to induce acute pancreatitis as above. In the single-strain and mixed-strain groups, mice received 1 mL of Lactobacillus plantarum B7 1 × 108 CFU/mL and 1 mL of Lactobacillus rhamnosus L34 1 × 108 CFU/mL and Lactobacillus paracasei B13 1 × 108 CFU/mL by oral gavage, respectively for 6 days starting 3 days prior to the AP induction. All mice were sacrificed 72 h after L-arginine injection. Pancreatic tissue was obtained for histological evaluation and immunohistochemical studies for myeloperoxidase, whereas ileal tissue was used for immunohistochemical studies for occludin, and claudin-1. Blood samples were collected for amylase analysis.ResultsSerum amylase levels and pancreatic myeloperoxidase levels in the AP group were significantly higher than in controls and significantly decreased in probiotic groups compared with the AP group. Ileal occludin and claudin-1 levels were significantly lower in the AP group than in controls. Ileal occludin levels significantly increased, whereas ileal claudin-1 levels did not significantly change in both probiotic groups as compared with the AP group. The pancreatic histopathology showed significantly higher degree of inflammation, edema, and fat necrosis in the AP group, and these changes improved in mixed-strained probiotic groups.ConclusionsProbiotics, particularly the mixed-strain ones, attenuated AP via the reduction of inflammation and the maintenance of intestinal integrity.

TBX3 is dynamically expressed in pancreatic organogenesis and fine-tunes regeneration

BackgroundThe reactivation of genetic programs from early development is a common mechanism for injury-induced organ regeneration. T-box 3 (TBX3) is a member of the T-box family of transcription factors previously shown to regulate pluripotency and subsequent lineage commitment in a number of tissues, including limb and lung. TBX3 is also involved in lung and heart organogenesis. Here, we provide a comprehensive and thorough characterization of TBX3 and its role during pancreatic organogenesis and regeneration.ResultsWe interrogated the level and cell specificity of TBX3 in the developing and adult pancreas at mRNA and protein levels at multiple developmental stages in mouse and human pancreas. We employed conditional mutagenesis to determine its role in murine pancreatic development and in regeneration after the induction of acute pancreatitis. We found that Tbx3 is dynamically expressed in the pancreatic mesenchyme and epithelium. While Tbx3 is expressed in the developing pancreas, its absence is likely compensated by other factors after ablation from either the mesenchymal or epithelial compartments. In an adult model of acute pancreatitis, we found that a lack of Tbx3 resulted in increased proliferation and fibrosis as well as an enhanced inflammatory gene programs, indicating that Tbx3 has a role in tissue homeostasis and regeneration.ConclusionsTBX3 demonstrates dynamic expression patterns in the pancreas. Although TBX3 is dispensable for proper pancreatic development, its absence leads to altered organ regeneration after induction of acute pancreatitis.

Differential expression of plasma exosomal microRNA in severe acute pancreatitis.

The incidence rate of acute pancreatitis is increasing, and severe acute pancreatitis (SAP) is associated with a high mortality rate, which may be reduced by a deeper understanding of its pathogenesis. In addition, an early determination of the severity of acute pancreatitis remains challenging. The aim of this study was to match potential biomarkers for early identification and monitoring of acute pancreatitis and to shed light on the underlying pathogenic mechanisms of SAP. The expression levels of plasma exosomal microRNA (miRNA) in patients with pancreatitis have been associated with the disease. Thus, this study compared the expression levels of exosomal miRNA in plasma collected from four patients with SAP and from four healthy participants. Analyses of the miRNA expression profiles indicated that three previously unreported miRNAs were differentially expressed in the patient group: Novel1, which was downregulated, and Novel2 and Novel3, which were upregulated. The miRNA target genes for those novel miRNAs were predicted using Metascape. Of these miRNA target genes, those that were also differentially expressed at different time points after disease induction in a mouse model of acute pancreatitis were determined. The gene for complement component 3 (C3), a target gene of Novel3, was the only gene matched in both the patient group and the mouse model. C3 appeared at most of the time points assessed after induction of acute pancreatitis in mice. These findings are foundational evidence that C3 warrants further study as an early biomarker of SAP, for investigating underlying pathogenic mechanisms of SAP, and as a therapeutic target for ameliorating the occurrence or development of SAP.

Butyrate Ameliorates Intestinal Epithelial Barrier Injury Via Enhancing Foxp3+ Regulatory T-Cell Function in Severe Acute Pancreatitis Model.

Background:This study aimed to examine the effect of sodium butyrate on severe acute pancreatitis-related gut barrier injury in a rat model and explore its mechanism.Methods:Male rats randomly fell into 3 groups, that is, the control, the severe acute pancreatitis group, and the severe acute pancreatitis + butyrate group. Rats in the control group received sham operation, while rats in the severe acute pancreatitis group and severe acute pancreatitis + butyrate group received severe acute pancreatitis induction by intraductal infusion of 4% sodium taurocholate. After that, rats in the severe acute pancreatitis + butyrate group were fed with sodium butyrate solution with free access. Intestinal barrier injury was measured based on the expression of tight junction proteins by reverse transcription polymerase chain reaction, Western blotting assay as well as immunohistochemical staining. The variation of Treg cells was measured by reverse transcription polymerase chain reaction, Western blotting assay, immunohistochemical staining, and flow cytometry analysis.Results:Compared to rats in the control, rats in the severe acute pancreatitis group showed significantly higher pathohistological scores (P < .001) in the intestine, as well as decreased expression of occludin and ZO-1. While, rats in the severe acute pancreatitis + butyrate group showed mitigated histologic lesions (P < .05) and increased expressions of occludin and ZO-1. In addition, rats in the severe acute pancreatitis group showed the obvious reduction in the expressions of Foxp3 and GPR109a and the decreased percentage of Treg cells in the intestine (P < .001) compared to rats in the control. However, rats in the severe acute pancreatitis + butyrate group showed markedly increased expressions of Foxp3 and GPR109a and the upregulated percentage of Treg cells (P < .01).Conclusion:Butyrate could significantly mitigate the intestinal injury induced by severe acute pancreatitis, probably by inducing the differentiation of Treg cells.

Significant Succession of Intestinal Bacterial Community and Function During the Initial 72 Hours of Acute Pancreatitis in Rats.

Acute pancreatitis (AP) is followed by structural and functional changes in the intestine, resulting from microbiome dysbiosis. However, it remains unclear how gut microbiome changes within the initial 72h of onset. In this study, severe acute pancreatitis (SAP), mild acute pancreatitis (MAP), and sham operation (SO) were replicated in rat models. 16S ribosomal RNA gene sequencing was used to explore the gut bacteria community. The predicted Cluster of Orthologous Genes (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways were associated with the 16S rRNA profiles. Compared to the SO group, significant community succession was found during the initial 72h in AP group. At 72 h after AP induction, the Firmicutes/Bacteroidetes (F/B) ratios were significantly different, with the highest ratio in SAP group and the lowest in MAP group. Lactobacillus was the most abundant genus, but it nearly disappeared in SAP rats at 72 h. Clostridiaceae 1 and Clostridium sensu stricto 1 were significantly enriched in AP group. Bacteroidales S24-7 and Bacteroidales S24-7 group norank were enriched in MAP group, while Collinsella, Morganella, and Blautia were enriched in SAP group. Lactobacillus was significantly correlated with nine COGs. Nine COGs showed significant differences between AP group and SO group. Moreover, four COGs showed significant differences between the MAP and SAP groups. KEGG Level_3 pathways propanoate metabolism (Ko00640) in AP group was significantly higher than that in SO group. The aspartate‒ammonia ligase and four KEGG orthology terms of the AP group were lower than that in the SO group, respectively. All these results suggest that the intestinal bacterial community structure and function was changed during the initial 72h in AP rats. The intestinal F/B ratio and the relative abundance of Lactobacillus could be potential markers for early diagnosis of MAP and SAP. The genus Clostridium sensu stricto 1 was the most enriched genus in AP, and may be an important marker for AP.

Reorienting of pramipexole as a promising therapy for acute pancreatitis in a rat model by suppressing TLR4\NF-κB p65\NLRP3 inflammasome signaling.

Acute pancreatitis (AP), a disorder of global importance, has a growing incidence and prevalence, particularly in the Western world. Its complications include pseudocysts and chronic pancreatitis. Pramipexole (PMX), a D2/3 receptor selecting agonist used in Parkinsonism, was reported to have anti-inflammatory effects. This study explored the potential curative role of PMX in an l-arginine-induced acute pancreatitis rat model in addition to a possible mechanistic pathway. Rats were divided randomly into three groups: control, l-arginine, and l-arginine+PMX. Seven days after AP induction, rats were decapitated and estimated for serum amylase, lipase, glucose, pancreatic inflammatory mediators toll-like receptor-4, nuclear factor κ B p65, serum tumor necrosis factor-α, NOD-, LRR and pyrin domain- containing protein 3 (NLRP3) inflammasome, caspase-1, interleukin 1β, oxidative biomarkers malondialdehyde, myeloperoxidase, nitrite/nitrate, reduced glutathione, and the apoptotic marker caspase-3, with pancreatic histopathological changes. l-arginine-mediated AP was proved by elevated serum lipase and amylase and pancreatic inflammatory, oxidative, and apoptotic markers with infiltration of inflammatory cells usinghematoxylin and eosinstain. PMX improved all these adverse signs of AP greatly. PMX might be considered an innovative therapy for AP due to its remarkable antioxidant, antiapoptotic, and anti-inflammatory effects, which are attributed to the suppression of the NLRP3 inflammasome and its downstream inflammatory cytokines.