Rat Model Of Acute Pancreatitis Research Articles

HSP70 protects against acute pancreatitis-elicited intestinal barrier damage in rats

Acute pancreatitis (AP) is a frequent but severe abdominal emergency in general surgery with intestinal barrier dysfunction. Heat shock protein 70 (HSP70) is a ubiquitous molecular chaperone that has been proposed to exert favorable effects on AP. Nonetheless, the detailed impacts of HSP70 on the intestinal barrier function in AP are unknown, which will be investigated here. After the injection of sodium taurocholate into the biliopancreatic duct, the rat models of AP were established. After modeling, HSP70 expression was up-regulated through lentivirus infection. Western blot was used to detect HSP70 expression. H&E staining was used to examine the histological changes in the pancreatic and intestinal tissues. The levels of pancreatic biochemical markers and oxidative stress markers were detected using corresponding assay kits. ELISA was used to detect the levels of inflammatory cytokines and gastrointestinal function indicators. Immunofluorescence staining and Western blot were used to detect the expression of tight junction proteins. DCFH-DA probe and MitoSOX Red probe were used to detect total reactive oxygen species (ROS) and mitochondrial ROS (mtROS), respectively. TUNEL assay and Western blot were used to detect apoptosis. During the model construction, severe pancreatic and abnormal intestinal tissue abnormalities were observed, inflammatory response was activated and the intestinal barrier was disrupted. HSP70 expression was down-regulated in the intestinal tissues AP rat models. HSP70 ameliorated the morphological damage of pancreatic and intestinal tissues of AP rats. In addition, HSP70 significantly reduced intestinal barrier damage, inflammatory response, oxidative stress and apoptosis in the intestinal tissues of AP rat models. Collectively, HSP70 might attenuate AP through exerting anti-inflammatory, anti-oxidant, anti-apoptotic effects and inhibiting intestinal barrier disruption.

The Predictive Value of Serum DAO, HDC, and MMP8 for the Gastrointestinal Injury in the Early Stage of Acute Pancreatitis in an Animal Model and a Clinical Study.

This study was aimed at exploring the use of the acute gastrointestinal injury (AGI) grade and sensitive biomarkers to investigate gastrointestinal (GI) injury in early stage of acute pancreatitis (AP). The AGI grade was used to evaluate intestinal function. Any GI injury above grade I (grades II-IV) was considered as severe. An AP rat model was created by retrograde injection of 4% sodium taurocholate. The pancreatic and intestinal histopathology scores were calculated by hematoxylin-eosin staining. Human and rat sera were assessed using ELISA. Tight junction (TJ) proteins were detected by Western blotting. In clinical study, the GI injury rate in mild acute pancreatitis (MAP), moderate severe acute pancreatitis (MSAP), and severe acute pancreatitis (SAP) groups was 26.8%, 78.4%, and 94.8%, respectively (P < 0.05). Diamine oxidase (DAO), histidine decarboxylase (HDC), and matrix metalloproteinase 8 (MMP8) serum levels were higher in AP patients than in healthy people (P < 0.05). Patients with GI injury had higher serum levels of DAO, HDC, and MMP8 than those without GI injury (P < 0.05). In animal experiments, the serum levels of DAO, HDC, and MMP8 were higher in the AP group than in normal and sham-operated (SO) groups (P < 0.05). The expressions of tricellulin, claudin-1, ZO-1, and occludin were significantly lower in the AP group than in normal and SO groups (P < 0.05). The serum levels of DAO, HDC, and MMP8 are novel biomarkers of GI injury in the early stage of AP; their elevation indicates the development of GI injury in AP. The intestinal TJ disruption may be a primary mechanism of GI injury and requires more in-depth research.

Studies Related to the Involvement of EsA in Improving Intestinal Inflammation in Acute Pancreatitis via the NF-κB Pathway.

Acute pancreatitis (AP) is a clinically frequent acute abdominal condition, which refers to an inflammatory response syndrome of edema, bleeding, and even necrosis caused by abnormal activation of the pancreas's own digestive enzymes. Intestinal damage can occur early in the course of AP and is manifested by impaired intestinal mucosal barrier function, and inflammatory reactions of the intestinal mucosa, among other factors. It can cause translocation of intestinal bacteria and endotoxins, further aggravating the condition of AP. Therefore, actively protecting the intestinal mucosal barrier, controlling the progression of intestinal inflammation, and improving intestinal dynamics in the early stages of AP play an important role in enhancing the prognosis of AP. The viability and apoptosis of RAW264.7 cells treated with Esculentoside A (EsA) and/or lipopolysaccharide were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. The expression of apoptosis-related proteins and NF-κB signaling pathway-related proteins were detected by western blot (WB). An enzyme-linked immunosorbent assay was used to measure TNF-α and IL-6 secretion. In vitro experiments demonstrated that EsA not only promoted the apoptosis of inflammatory cells but also reduced the secretion of TNF-α and IL-6 in a dose-dependent manner. Additionally, it inhibited the activation of the NF-κB signaling pathway by decreasing the expression of phosphorylated-p65(p-p65) and elevating the expression of IκBα. Similarly, in vivo experiments using a rat AP model showed that EsA inhibited the expression of p-p65 elevating the expression of IκBα in the intestinal tissues of the rat AP model and promoting the apoptosis of inflammatory cells in the intestinal mucosa in vivo experiments, while improving the pathological outcome of the pancreatic and intestinal tissues. Our results suggest that EsA can reduce intestinal inflammation in the rat AP model and that EsA may be a candidate for treating intestinal inflammation in AP and further arresting AP progression.

Ameliorative Effects of Larazotide Acetate on Intestinal Permeability and Bacterial Translocation in Acute Pancreatitis Model in Rats.

Intestinal barrier dysfunction in acute pancreatitis (AP) may progress to systemic inflammatory response syndrome (SIRS) and multi-organ failures by causing bacterial translocation. Larazotide acetate (LA) is a molecule that acts as a tight junction (TJ) regulator by blocking zonulin (Zo) receptors in the intestine. In our study, we aimed to investigate the effects of LA on intestinal barrier dysfunction and bacterial translocation in the AP model in rats. Thirty-two male Sprague-Dawley rats were divided into 4 groups; control, larazotide (LAR), AP, and AP + LAR. The AP model was created by administering 250 mg/100 g bm L-Arginine intraperitoneally 2 times with an hour interval. AP + LAR group received prophylactic 0.01 mg/mL LA orally for 7 days before the first dose of L-Arginine. For intestinal permeability analysis, fluorescein isothiocyanate-dextran (FITC-Dextran) was applied to rats by gavage. The positivity of any of the liver, small intestine mesentery, and spleen cultures were defined as bacterial translocation. Histopathologically damage and zonulin immunoreactivity in the intestine were investigated. Compared to the control group, the intestinal damage scores, anti-Zo-1 immunoreactivity H-Score, serum FITC-Dextran levels and bacterial translocation frequency (100% versus 0%) in the AP group were significantly higher (all p < 0.01). Intestinal damage scores, anti-Zo-1 immunoreactivity H-score, serum FITC-Dextran levels, and bacterial translocation frequency (50% versus 100%) were significantly lower in the AP + LAR group compared to the AP group (all p < 0.01). Our findings show that LA reduces the increased intestinal permeability and intestinal damage by its effect on Zo in the AP model in rats, and decreases the frequency of bacterial translocation as a result of these positive effects.

Cysteine-modified PEGylated nanoparticles for targeted delivery of methylprednisolone to pancreatitis

The timely suppression of inflammatory mediator production and mitigation of their effects on pancreatic acinar cells are crucial for the successful management of acute pancreatitis. To achieve effective treatment, we present a novel approach utilizing cysteine modified PEG nanoparticles for both precise accumulation at the site of pancreatitis and specific targeting of acinar cells. Methylprednisolone, a nonsteroidal anti-inflammatory drug, was tailored to enhance its circulation time in the bloodstream, preferentially accumulate in the pancreas and enhance cell uptake efficiency by acinar cells through specifically targeting L-Type amino acid transporter 1. The nanosystem significantly downregulated pro-inflammatory cytokines in plasma, resulting in the effective suppression of inflammation in acinar cells within an acute pancreatitis rat model. The utilization of the dual targeted therapy strategy holds considerable potential for the clinical management of pancreatitis.

Efficacy of Agmatine Treatment in Experimental Acute Pancreatitis Rat Model.

Acute pancreatitis which is characterized by pancreatic inflammation can sometimes be difficult to treat because of limited therapeutic options. The purpose of the study was to assess the effects of agmatine in the acute pancreatitis experimental rat model. An acute pancreatitis model was created with the administration of cerulein in 40 female Sprague-Dawley rats. Agmatine was administered as a protective agent at 5 mg/kg (low dose) and 10 mg/kg (high dose). The rats were divided into 5 groups, each with 8 rats: group 1 (acute pancreatitis); group 2 (acute pancreatitis+low-dose agmatine 5 mg/kg); group 3 (acute pancreatitis+high-dose agmatine 10 mg/kg); group 4 (placebo, acute pancreatitis+saline); and group 5 (sham and saline infusion). All rats were sacrificed 24 hours after the last injection, and the levels of superoxide dismutase, interleukin-1 beta, and tumor necrosis factor-alpha were assessed in blood samples collected via cardiac puncture. Histopathological examination was performed by a pathologist, who was blind to the groups, according to the Schoenberg's pancreatitis scoring index. The amylase (16.67 and 37.89 U/L), glutathione peroxidase (13.62 and 18.44 ng/mL), tumor necrosis factor-α (39.68 and 64 ng/mL), interleukin-1 (484.73 and 561.83 pg/mL), and transforming growth factor-β (110.52 and 126.34 ng/L) levels were significantly lower and superoxide dismutase (1.29 and 0.98 ng/L) and malondialdehyde (0.99 and 0.96 nmol/mL) levels were significantly higher in group 3 compared to group 1 (P < .05). Moreover glutathione peroxidase, tumor necrosis factor-α, and transforming growth factor-β levels were lower, and malondialdehyde levels were higher in the group 3 compared to group 2 (P < .05). Although the Schoenberg's pancreatitis scoring index was not significantly different between the high- and low-dose treatment groups, rats who received high-dose treatment had significantly lower scores compared to those with acute pancreatitis group. This is the first study that evaluated the efficacy of agmatine in an experimental model of acute pancreatitis. Agmatine, an anti-inflammatory and antioxidant agent, had a protective effect in an experimental rat model of acute pancreatitis.

Protective effect of rivastigmine against lung injury in acute pancreatitis model in rats via Hsp 70/IL6/ NF-κB signaling cascade.

Acute lung injury (ALI) that develops as a result of AP can progress to acute respiratory distress syndrome. Some hypotheses are proposed to explain the pathophysiology of AP and its related pulmonary hazards. This experiment aimed to evaluate the mitigating action of rivastigmine (Riva) in lung injury that occurs on the top of acute pancreatitis (AP) induced in rats. Thirty-two male Wister rats were randomized to one of four groups: control, Riva-treated, acute pancreatitis (AP), and acute pancreatitis treated by Riva. Serum amylase and lipase levels were assessed. Pulmonary oxidative stress and inflammatory indicators were estimated. A pancreatic and pulmonary histopathological examination, as well as an immunohistochemical study of HSP70, was carried out. Riva significantly attenuated the L-arginine-related lung injury that was characterized by increased pulmonary inflammatory biomarkers (interleukin-6 [IL-6]), nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), increased pulmonary oxidative markers (total nitrite/nitrate [NOx]), MDA, decreased total antioxidant capacity (TAC), and reduced glutathione level (GSH)) with increased caspase-3 expression. Therefore, Riva retains potent ameliorative effects against lung injury that occur on the top of AP by relieving oxidative stress, inflammation, and apoptosis via HSP70/IL6/NF-κB signaling.

Comparison of the therapeutic effect of native and preconditioned human umbilical cord-derived multipotent mesenchymal stromal cells on a rat model of acute pancreatitis

Pancreatitis is a disease characterized by an acute or chronic inflammatory process of the pancreas, induced by the activation of trypsin inside acinocytes. These processes result in necrosis of the organ's parenchyma, abscess formation, and systemic complications, contributing to patient mortality rates ranging from 30-47%. As of now, there is no globally recognized effective treatment for acute pancreatitis. Multipotent mesenchymal stem cells (MMSCs) are potential candidates for treating this disease due to their immunomodulatory properties. The aim of this study was to compare the therapeutic effects of transplanting native human umbilical cord-derived MMSCs (hUC-MMSCs) with hUC-MMSCs preconditioned with H2O2 in a rat model of acute pancreatitis. Materials and methods. Acute pancreatitis in rats was induced by intraperitoneal injection of L-arginine at a dose of 3.5 g/kg body weight at an interval of 1 hour. The rats were then categorized into four groups. Group 1 – negative control, where animals received a physiological solution; group 2 – positive control (pancreatitis). Three days after the onset of signs of developed acute pancreatitis, group 3 rats were intraperitoneally transplanted with native hUC-MMSCs, meeting the minimum criteria of the International Society for Cell and Gene Therapy, at a dose of 1.5×106 cells/kg. Group 4 received the same dose of hUC-MMSCs, but these cells were preconditioned with H2O2 at a concentration of 30 µM for 18 hours. The effects of both native and preconditioned hUC-MMSCs were evaluated at 3, 7, and 14 days after their introduction. Assessment criteria included the α-amylase index, identification of insulin in the islets of Langerhans, and histological analysis. Results. It was demonstrated that, three days post L-arginine administration, the α-amylase level surged by five times compared to the negative control, and blood glucose levels increased by 2.5 times, indicating damage to both the exocrine and endocrine parts of the pancreas. Microscopic examination revealed a 3.5-fold increase in fibrosis of the pancreatic parenchyma compared to the negative control. Three days after the transplantation of native hUC-MMSCs, the α-amylase level in the blood decreased by 1.7 times, and in the variant with preconditioned hUC-MMSCs, it decreased by 2 times compared to Group 2. By day 7, the α-amylase index in the native hUC-MMSCs group decreased by 2.4 times compared to the positive control, and in the preconditioned hUC-MMSCs group, it approached normal levels. A gradual recovery of the pancreatic architecture was observed by day 7, with a faster recovery in the preconditioned MMSCs group. Histological sections revealed a replacement of nuclei-free areas with acinocytes, indicated by a 3-fold decrease in the number of nuclei-free cells in the native hUC-MMSCs transplantation, and almost normal levels in the preconditioned hUC-MMSCs group. Both variants exhibited a positive histochemical PAS-reaction for the identification of insulin in the islets of Langerhans, and blood glucose levels corresponded to the norm. After 14 days, complete recovery of the pancreas was observed in both variants. Conclusion. The study results indicate that hUC-MMSCs transplantation in rats with acute pancreatitis contributes to the restoration of pancreatic parenchyma architecture and function. Moreover, the administration of MMSCs preconditioned with H2O2 significantly enhances the therapeutic effect, expediting the recovery process of the pancreas in animals.

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.

Honokiol reduces oxidative stress by activating the SIRT3-MnSOD2 pathway to alleviate hypertriglyceridemia-induced acute pancreatitis in rats

To determine how honokiol affects the sirtuin-3 (SIRT3)-MnSOD2 pathway and oxidative stress in rats with hypertriglyceridemia-induced acute pancreatitis (HTGP). Thirty 4-week-old male SD rats were randomly divided into two groups for normal feeding and high-fat feeding for 4 weeks, after which the rats with normal feeding were randomized into control group and acute pancreatitis (AP) group (n=6), and those with high-fat feeding were divided into hypertriglyceridemia group, HTGP group, and honokiol treatment group (n=6). In AP, HTGP, and honokiol groups, AP models were established by intraperitoneal injection of cerulean; in honokiol group, the rats received an intraperitoneal injection of 5 mg/kg honokiol 15 min after cerulean injection. Serum TG, IL-6, and TNF-α levels were measured 24 h after the treatments, and pathological changes in the pancreas were observed with HE staining; The levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione peroxidase (GSH) were measured, and SIRT3 and manganese superoxide dismutase (MnSOD2) expressions were detected using Western blotting and immunohistochemistry. Transmission electron microscopy was used to examine the ultrastructure of pancreatic acinar cells and mitochondria. Compared with the those with normal feeding, the rats with high-fat feeding had significantly elevated serum TG level (P < 0.05). The rat models of AP showed significantly increased serum levels of IL-6, TNF-α, and MDA and decreased GSH level and expressions of SIRT3 and MnSOD2, with obvious edema and inflammatory cell infiltration and enhanced ROS fluorescence intensity in the pancreas and ultrastructural damages of the acinar cells and mitochondria. In rats with HTGP, honokiol treatment significantly decreased serum levels of IL-6, TNF-α, and MDA, increased GSH level and SIRT3 and MnSOD2 expressions, reduced ROS production, and alleviated ultrastructural damage of the acinar cells and mitochondria in the pancreas. Honokiol reduce oxidative stress and alleviates pancreatic injuries in HTGP rats possibly by activating the SIRT3-MnSOD2 pathway.

Integrative proteomics, phosphoproteomics and acetylation proteomics analyses of acute pancreatitis in rats.

Acute pancreatitis (AP) is a common acute abdominalgia of the digestive tract. When the disease progresses to severe acute pancreatitis (SAP), the complications and mortality rate greatly increase. Determining the key factors and pathways underlying AP and SAP will help elucidate the pathological processes involved in disease progression and will be beneficial for identifying potential therapeutic targets. We conducted an integrative proteomics, phosphoproteomics and acetylation proteomics analysis of pancreas samples collected from normal, AP and SAP rat models. We identified 9582 proteins, 3130 phosphorylated modified proteins, and 1677 acetylated modified proteins across all samples. The differentiated expression proteins and KEGG pathway analysis suggested the pronounced enrichment of key pathways based on the following group comparisons: AP versus normal, SAP versus normal, and SAP versus AP. Integrative proteomics and phosphoproteomics analyses revealed 985 jointly detected proteins in the comparison of AP and normal samples, 911 proteins in the comparison of SAP and normal samples, and 910 proteins in the comparison of SAP and AP samples. Based on proteomics and acetylation proteomics analyses, we found that 984 proteins were jointly detected in the comparison of AP and normal samples, 990 proteins in SAP and normal samples, and 728 proteins in SAP and AP samples. Thus, our study offers a valuable resource to understand the proteomic and protein modification atlas in AP.

The role of serum nesfatin-1 in a rat model of acute pancreatitis.

Acute pancreatitis (AP) is a disease that can still be fatal despite rapid advances in medicine. The relationship between serum nesfatin-1 levels and AP is still to be fully resolved. To investigate the utility of serum nesfatin-1 levels in the diagnosis of AP. Twenty-four male Sprague Dawley rats were divided into control, mild pancreatitis and severe pancreatitis groups (n = 8/group). Acute pancreatitis was induced by cerulein injection and the control group received saline injections. Then, the serum nesfatin-1, amylase, lipase, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels were determined. A pathologist blinded to the study scored the severity of pancreatitis. There was a considerable decrease in serum nesfatin-1 levels in parallel to the severity of pancreatitis, though there was no statistically significant relationship observed between pancreatitis and nesfatin-1. In addition, there was no significant difference in AST or ALT levels among the groups. However, a strong positive correlation between amylase and lipase levels was observed (p < 0.05). The severe pancreatitis group (group 3) had a higher lipase level and pathology score than mild pancreatitis group (group 2), and this difference was statistically significant. Serum nesfatin-1 may be used as a diagnostic and severity marker in pancreatitis in the future.

A Nano-Liposomal Formulation of Caffeic Acid Phenethyl Ester Modulates Nrf2 and NF-κβ Signaling and Alleviates Experimentally Induced Acute Pancreatitis in a Rat Model.

The currently available management strategies for acute pancreatitis are inadequately effective which calls for exploration of new approaches to treat this condition. Caffeic acid phenethyl ester (CAPE) is a major bioactive constituent of honeybee propolis with promising therapeutic and preventive applications. However, its pharmaceutical potential and clinical use are hindered by its poor water solubility and limited plasma stability. In this study, we aimed to prepare, characterize and evaluate a CAPE-loaded nanoliposomal formulation to improve the efficacy of CAPE for the management of acute pancreatitis. The CAPE-loaded nanoliposomes (CAPE-loaded-NL) were prepared by a thin layer evaporation technique and were optimized using three edge activators. CAPE-loaded-NL were characterized for their vesicle size (VS), zeta potential (ZP), encapsulation efficiency (EE), polydispersity index (PDI), crystalline state and morphology. The protective effect of the optimal CAPE-loaded-NL was evaluated in a rat model of acute pancreatitis induced by administering a single intraperitoneal injection of L-ornithine. Oral pretreatment with CAPE-loaded-NL significantly counteracted ornithine-induced elevation in serum activities of pancreatic digestive enzymes and pancreatic levels of malondialdehyde, nuclear factor kappa B (NF-κB) p65, tumor necrosis factor-alpha, nitrite/nitrate, cleaved caspase-3 and myeloperoxidase activity. Moreover, pretreatment with CAPE-loaded-NL significantly reinstated the ornithine-lowered glutathione reductase activity, glutathione, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 levels and ATP/ADP ratio, and potentiated the Bcl-2/Bax ratio in pancreatic tissue. CAPE-loaded-NL displayed superior antioxidant, anti-inflammatory and anti-apoptotic effects compared to free CAPE oral suspension and achieved a more potent correction of the derangements in serum amylase and pancreatic myeloperoxidase activities. The histological observations were in line with the biochemical findings. Our results suggest that CAPE-loaded-NL provide a promising interventional approach for acute pancreatitis mainly through the enhancement of the exerted antioxidant, anti-inflammatory and anti-apoptotic effects which may be mediated, at least in part, through modulation of Nrf2 and NF-κβ signaling.

Echinacoside alleviates pancreatic injury via exerting anti-inflammatory and anti-oxidant activities in a rat model of acute pancreatitis

Echinacoside alleviates pancreatic injury via exerting anti-inflammatory and anti-oxidant activities in a rat model of acute pancreatitis

Acinar Cell-Derived Extracellular Vesicle MiRNA-183-5p Aggravates Acute Pancreatitis by Promoting M1 Macrophage Polarization Through Downregulation of FoxO1.

Acute pancreatitis (AP) is a common cause of a clinically acute abdomen. Crosstalk between acinar cells and leukocytes (especially macrophages) plays an important role in the development of AP. However, the mechanism mediating the interaction between acinar cells and macrophages is still unclear. This study was performed to explore the role of acinar cell extracellular vesicles (EVs) in the crosstalk between acinar cells and macrophages involved in the pathogenesis of AP. EVs derived from caerulein-treated acinar cells induced macrophage infiltration and aggravated pancreatitis in an AP rat model. Further research showed that acinar cell-derived EV miR-183-5p led to M1 macrophage polarization by downregulating forkhead box protein O1 (FoxO1), and a dual-luciferase reporter assay confirmed that FoxO1 was directly inhibited by miR-183-5p. In addition, acinar cell-derived EV miR-183-5p reduced macrophage phagocytosis. Acinar cell-derived EV miR-183-5p promoted the pancreatic infiltration of M1 macrophages and increased local and systemic damage in vivo. Subsequently, miR-183-5p overexpression in macrophages induced acinar cell damage and trypsin activation, thus further exacerbating the disease. In clinical samples, elevated miR-183-5p levels were detected in serum EVs and positively correlated with the severity of AP. EV miR-183-5p might play an important role in the development of AP by facilitating M1 macrophage polarization, providing a new insight into the diagnosis and targeted management of pancreatitis.Graphical abstract of the present study. In our caerulein-induced AP model, miR-183-5p was upregulated in injured acinar cells and transported by EVs to macrophages. miR-183-5p could induce M1 macrophage polarization through downregulation of FoxO1 and the release of inflammatory cytokines, which could aggravate AP-related injuries. Therefore, a vicious cycle might exist between injured ACs and M1 macrophage polarization, which is fulfilled by EV-transported miR-183-5p, leading to sustainable and progressive AP-related injuries.

Ibuprofen Alleviates Acute Pancreatitis- (AP-) Induced Myocardial Injury by Inhibiting AIM2.

ObjectiveThe lack of certain trace elements such as selenium, molybdenum, magnesium or related nutrients in the soil, water quality and food in the disease area, which caused disturbance of myocardium metabolism and resulted in injury and necrosis. The aim of the study was to explore the mechanism of ibuprofen alleviating myocardial injury caused by acute pancreatitis (AP). Method We have established AP cell model and rat model. HE staining is used for histological examination. ELISA is used to determine the levels of proinflammatory cytokines (TNF-α and IL-6) and markers of myocardial injury (LDH and CK-MB). qRT-PCR and Western blot are used to analyze the mRNA and protein levels of related genes. Results The expression level of AIM2 was significantly increased in AP cells; downregulation of AIM2 alleviated inflammation and myocardial injury induced by AP cells; ibuprofen could inhibit the expression of AIM2 and alleviate inflammation and myocardial injury induced by AP cells. In vivo experiments have found that ibuprofen can inhibit the expression of AIM2 to alleviate myocardial injury in AP rat. Conclusion Ibuprofen can alleviate myocardial injury caused by acute pancreatitis by inhibiting the expression of AIM2.

The ciliary protein Spef2 stimulates acinar Ampkα/Sirt1 signaling and ameliorates acute pancreatitis and associated lung injury.

BackgroundPancreatic acinar cells are susceptible to nuclear factor kappa B (NF-κB)-mediated inflammation and resulting cell necrosis during early acute pancreatitis. As adenosine monophosphate-activated protein kinase alpha (Ampkα)/sirtuin 1 (Sirt1) pathway activity attenuates NF-κB activity, we examined whether the Ampkα/Sirt1 axis affects the progression of acute pancreatitis and associated lung injury in vivo. Furthermore, we explored the role of the ciliary protein sperm flagellar 2 (Spef2, Kpl2) in regulating Ampkα/Sirt1 activity in vitro and in vivo.MethodsPancreatic injury, oxidative stress, acinar cell necrosis and apoptosis, acinar levels of Ampkα/Sirt1/NF-κB signaling activity, NF-kB-mediated inflammatory markers, and markers of associated lung injury were measured in rat models of acute pancreatitis following pharmacological Ampkα activation with A769662 or self-complementary recombinant adeno-associated virus serotype 6 (scAAV6)-mediated Spef2 overexpression. Additional in vivo rescue studies involving Ampkα silencing and/or constitutively active (CA)-Sirt1 overexpression were performed in acute pancreatitis rats. In vitro immunoblotting and Ampkα activity assays were conducted in the pancreatic acinar cell line AR42J.ResultsPharmacological Ampkα activation or Spef2 overexpression reduced acute pancreatitis severity, oxidative stress, necrosis, apoptosis, NF-kB-mediated inflammatory markers, and the degree of associated lung injury. Spef2 overexpression in AR42J cells in vitro promoted AmpkαThr172 phosphorylation and Ampkα activity. In vivo rescue studies revealed that Spef2’s suppressive effect on acute pancreatitis and associated lung injury is mediated via the Ampkα/Sirt1 axis.ConclusionsThis study established the existence of a Spef2/Ampkα/Sirt1 axis in pancreatic acinar cells that is involved in the regulation of NF-κB-mediated acinar cell inflammation and resulting cell necrosis during acute pancreatitis.

Influence of Leptin on Severity of Acute Pancreatitis in Experimental Rat Model

Background and Aim: In acute pancreatitis, hyperproduction of inflammatory mediators, including inflammatory cytokines, exacerbation of tissue injury due to microcirculatory disturbances, secondary activation of inflammatory cells in distant organs, and the cascade are the pathogenic basis of pancreatitis severity. Therefore, inhibition of pancreatic enzyme activity, blocking production, and preventing the activation of inflammatory cells is a practical way to prevent the development of severe acute pancreatitis and multiorgan failure. In our study, we sought to elucidate the effect of leptin on a rat model of severe acute pancreatitis. Methods: We prepared an acute pancreatitis model in rats by intraperitoneal injection of 20μg/kg of leptin and single injection of 0.1mL/100g of bile into a pancreatic duct extending from the duodenal papilla, measured survival, serum amylase activity, MPO activity in pancreatic tissue, SOD activity and MDA content, and observed the histopathological findings of pancreatic tissue. Results: Pre-administration of 20μg/kg leptin improved the survival of rats, decreased serum amylase activity, MPO activity in pancreatic tissue, increased MDA content, increased SOD activity, and improved the histopathological features of pancreatic tissue. Conclusion: Leptin administration prevented the destruction of pancreatic cells and improved the antioxidant function in rats with severe acute pancreatitis.

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.

Blood\u2013brain barrier dysfunction in l-ornithine induced acute pancreatitis in rats and the direct effect of l-ornithine on cultured brain endothelial cells

BackgroundIn severe acute pancreatitis (AP) the CNS is affected manifesting in neurological symptoms. Earlier research from our laboratory showed blood–brain barrier (BBB) permeability elevation in a taurocholate-induced AP model. Here we aimed to further explore BBB changes in AP using a different, non-invasive in vivo model induced by l-ornithine. Our goal was also to identify whether l-ornithine, a cationic amino acid, has a direct effect on brain endothelial cells in vitro contributing to the observed BBB changes.MethodsAP was induced in rats by the intraperitoneal administration of l-ornithine-HCl. Vessel permeability and the gene expression of the primary transporter of l-ornithine, cationic amino acid transporter-1 (Cat-1) in the brain cortex, pancreas, liver and lung were determined. Ultrastructural changes were followed by transmission electron microscopy. The direct effect of l-ornithine was tested on primary rat brain endothelial cells and a triple co-culture model of the BBB. Viability and barrier integrity, including permeability and TEER, nitrogen monoxide (NO) and reactive oxygen species (ROS) production and NF-κB translocation were measured. Fluorescent staining for claudin-5, occludin, ZO-1, β-catenin, cell adhesion molecules Icam-1 and Vcam-1 and mitochondria was performed. Cell surface charge was measured by laser Doppler velocimetry.ResultsIn the l-ornithine-induced AP model vessel permeability for fluorescein and Cat-1 expression levels were elevated in the brain cortex and pancreas. On the ultrastructural level surface glycocalyx and mitochondrial damage, tight junction and basal membrane alterations, and glial edema were observed. l-ornithine decreased cell impedance and elevated the BBB model permeability in vitro. Discontinuity in the surface glycocalyx labeling and immunostaining of junctional proteins, cytoplasmic redistribution of ZO-1 and β-catenin, and elevation of Vcam-1 expression were measured. ROS production was increased and mitochondrial network was damaged without NF-κB, NO production or mitochondrial membrane potential alterations. Similar ultrastructural changes were seen in l-ornithine treated brain endothelial cells as in vivo. The basal negative zeta potential of brain endothelial cells became more positive after l-ornithine treatment.ConclusionWe demonstrated BBB damage in the l-ornithine-induced rat AP model suggesting a general, AP model independent effect. l-ornithine induced oxidative stress, decreased barrier integrity and altered BBB morphology in a culture BBB model. These data suggest a direct effect of the cationic l-ornithine on brain endothelium. Endothelial surface glycocalyx injury was revealed both in vivo and in vitro, as an additional novel component of the BBB-related pathological changes in AP.