Pharmacological prevention and treatment of acute pancreatitis: where are we now?

Rhein Protects Against Severe Acute Pancreatitis In vitro and In vivo by Regulating the JAK2/STAT3 Pathway

Rhein is widely used in inflammation treatment in China, but its effects on severe acute pancreatitis (SAP) have not been studied closely. This study investigated rhein’s protective effects against SAP using in vitro and in vivo models to determine whether its protective mechanism regulated the Janus kinase two and signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway. Thirty-six male Sprague–Dawley rats were randomised into sham operation, SAP and rhein groups. The SAP model was induced by retrograde pancreatic bile duct injection of sodium taurocholate. Serum TNF-α and interleukin (IL)-6 levels were determined by ELISA, whereas serum amylase and lipase concentrations were measured using test kits. Western blot and/or immunohistochemistry quantified JAK2 and STAT3 expression. Furthermore, histopathological pancreatic changes were detected by haematoxylin and eosin staining. AR42J cells were randomly divided into the control, cerulein and rhein groups. Amylase activity was assessed using an amylase test kit; the tumour necrosis factor-α (TNF-α) expression was determined by enzyme-linked immunosorbent assay (ELISA). JAK2 and STAT3 protein expression were evaluated by western blot. SAP was concomitant with increased JAK2 and STAT3 expressions in vivo. Pre-treatment with rhein attenuated serum TNF–α and IL-6 levels effectively, and notably reduced p-JAK2, p-STAT3, JAK2 and STAT3 protein expression. Rhein significantly alleviated pancreatic histopathology. Compared to untreated groups, rhein significantly reduced amylase activity in supernatants of AR42J cells induced by cerulein in vitro. Furthermore, rhein altered JAK2 and STAT3 protein levels in AR42J cells after cerulein induction. Overall, rhein exerted protective effect on SAP in vitro and in vivo, possibly through the JAK2/STAT3 signalling pathway.

High Serum Levels of High-Mobility Group Box 1 (HMGB1) and Low Levels of Heat Shock Protein 70 (Hsp70) are Associated with Poor Prognosis in Patients with Acute Pancreatitis

INTRODUCTION

Cell damage in Acute Pancreatitis (AP) lead to release of cytokines and HMGB1 and Hsp70. While Hsp70 plays a role in cytoprotection, when released to extracellular milieu constitutes, as HMGB1, a danger signal and trigger pro-inflammatory responses. These molecules seem to be related to the clinical progression; but because no evidence exists about them as molecular network in AP development, we quantify HSP70, HMGB1, and cytokines in patients with AP and search for correlations with severity and prognosis.

METHODS

Fifteen patients with AP were included. The average age was 52 years. Six patients had mild pancreatitis, 4 were moderately severe and 5 with a severe form. Blood samples were taken within the first 24 h, at 3d and 7d from the start. Serum HMGB1 and Hsp70 were determined using ELISA; TNF-α, IL-1β, IL-6, IL-8, IL-10 and IL-12p70 were determined by bead based immuassay.

RESULTS

Of all 15 patients recruited, 4 were women. Eight patients had APACHEII score higher than 8. Two patients died from AP related complications. Increase in serum HMGB1 and decrease of Hsp70 were associated with the severity and mortality. TNF-α, IL-6 and IL-8 were higher in patients that did not survive, in those with an APACHE II >8, and in those with severe AP.

CONCLUSIONS

High HMGB1 and low Hsp70 were associated with poor prognosis. Hsp70 might play a protective role in AP. TNF-α, IL-6, IL-8, HMGB1 and Hsp70 during hospital admissions might serve to evaluate risk of death due to AP.

Updates in Pediatric Pancreatology: Proceedings of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition Frontiers in Pediatric Pancreatology Symposium

The Pancreas Committee of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition aims to promote awareness of pediatric pancreatic diseases, support clinical and basic science research in the field, educate pediatric gastroenterologists, and advocate on behalf of pediatric patients with pancreatic disorders. At the 2017 Annual North American Society for Pediatric Gastroenterology, Hepatology and Nutrition meeting, the Pancreas Committee held a full day symposium on pediatric pancreatic diseases, entitled, "Frontiers in Pediatric Pancreatology." The symposium served as a timely and novel academic meeting that brought together individuals with a vested interest in the care of children with pancreatic disorders. The objective of this day-long course was to update practicing gastroenterologists on the latest advances in research, management algorithms, endoscopic therapies, radiographic resources, surgical approaches, and novel drug therapies targeted to pediatric pancreatitis. Presentations were divided into 4 modules: diagnosis, risk factors, and natural history of pancreatitis; pancreatic imaging and exocrine function; management of pancreatitis; and new frontiers in pediatric pancreatitis research. The course fostered a unique ecosystem for interdisciplinary collaboration, in addition to promoting discussion and stimulating new research hypotheses regarding pediatric pancreatic disorders. Oral presentations by experts in various fields of pancreatology led to thought-provoking discussion; in addition, a meet-the-professor luncheon stimulated critical evaluation of current research in pediatric pancreatic diseases, highlighting knowledge gaps and future research endeavors. The current report summarizes the major learning points from this novel symposium focusing on the growing demographic of pediatric pancreatic diseases.

Granulocyte colony-stimulating factor enhances the therapeutic efficacy of bone marrow mesenchymal stem cell transplantation in rats with experimental acute pancreatitis

INTRODUCTION

Acute pancreatitis (AP) is one of the most common diseases involving necrotic inflammation. Bone marrow mesenchymal stem cells (BMMSCs) have the potential of multi-directional differentiation and self-renewal for tissue repair. It remains less clear if granulocyte colony-stimulating factor (G-CSF) can improve the therapeutic effect of BMMSC transplant in AP. Therefore, we explored this issue in a rat model of experimental AP.

RESULTS

Transplanted PKH26-positive BMMSCs were present in the injured pancreatic tissue, with some cells co-expressed pancreatic cellular markers, including Pax-4, Ngn3 and Nkx-6. Pathological, biochemical and serological data suggested an improvement in histological and functional recovery in these animals relative to control. Overall, the AP model rats received BMMSCs and G-CSF co-treatment showed better recovery in terms of tissue regeneration and blood biochemical levels relative to other groups.

MATERIALS AND METHODS

BMMSCs from donor rats were labeled with the fluorescent dye PKH26 and transfused into recipient rats with AP induced by L-arginine. The animals were divided into a control group, and groups treated with BMMSCs, G-CSF, and BMMSCs together with G-CSF. Therapeutic effects were evaluated histologically with immunohistochemistry and immunofluorescence, together with biochemical measurement of pancreatic markers.

CONCLUSION

G-CSF therapy with BMMSC transplantation improves histological and functional outcomes in rats with experimental AP.

Deferasirox pharmacogenetic influence on pharmacokinetic, efficacy and toxicity in a cohort of pediatric patients

AIM

We aimed to evaluate the influence of genetic polymorphisms involved in deferasirox metabolism and transport on its pharmacokinetics and treatment toxicity, in a cohort of β-thalassaemic children.

PATIENTS & METHODS

Drug plasma concentrations were measured by a HPLC-UV method. Allelic discrimination for UGT1A1, UGT1A3, CYP1A1, CYP1A2, CYP2D6, MRP2 and BCRP1 polymorphisms was performed by real-time PCR.

RESULTS

CYP1A1 rs2606345AA influenced C_trough (p = 0.001) and t_1/2 (p = 0.042), CYP1A1 rs4646903TC/CC (p = 0.005) and BCRP1 rs2231142GA/AA (p = 0.005) influenced T_max and CYP2D6 rs1135840CG/GG influenced C_max (p = 0.044). UGT1A1 rs887829TT (p = 0.002) and CYP1A2 rs762551CC (p = 0.019) resulted as predictive factor of ferritin levels and CYP1A1 rs2606345CA/AA (p = 0.021) and CYP1A2 rs762551AC/CC (p = 0.027) of liver iron concentration.

CONCLUSION

Our data suggest the usefulness of deferasirox pharmacogenetics in pediatric treatment optimization.

Up-regulation of Tight-Junction Proteins by p38 Mitogen-Activated Protein Kinase/p53 Inhibition Leads to a Reduction of Injury to the Intestinal Mucosal Barrier in Severe Acute Pancreatitis

OBJECTIVES

The aim of this study was to explore the role of the p38 mitogen-activated protein kinase (p38MAPK)/p53 signaling pathway in injury to the intestinal mucosal barrier during severe acute pancreatitis (SAP).

METHODS

Both sham operation and SAP groups had 3 subgroups analyzed 3, 6, or 12 hours after the SAP induction. The concentrations of amylase, endotoxin, diamine oxidase, tumor necrosis factor α, and phospho-p38MAPK, p53, and caspase-3 and the messenger RNA levels of zonula occludens protein-1 and occludin in the intestine were measured. Immunohistochemical staining was used to determine the expression of zonula occludens protein-1 and occludin. Pathological changes of the pancreas and intestine were also assessed. Then, rats were randomly assigned to 5 groups-sham operation group, SAP group, 3 groups treated with different concentrations of p38MAPK-inhibitor SB203580-and the abovementioned experiment was repeated and analyzed 6 hours after the SAP induction.

RESULTS

The phospho-p38MAPK reached a peak value at 6 hours after the SAP induction with obvious pathological injury to the pancreas and intestine. Treatment with SB203580 led to a less damage to the pancreatic and intestinal tissues.

CONCLUSIONS

These results suggest that SAP activates the p38MAPK/p53 signaling pathway and induces injury to the intestinal mucosal barrier, which can be alleviated by inhibiting the p38MAPK/p53 pathway.

Effects of everolimus on a rat model of cerulein-induced experimental acute pancreatitis

OBJECTIVE

To analyze the biochemical and histopathological effects of everolimus in an experimental rat model of cerulein-induced acute pancreatitis. The aim of the present study was to determine the effects of everolimus on blood biochemical parameters and tissue histopathology in an experimental rat model of cerulein-induced acute pancreatitis.

MATERIAL AND METHODS

In 30 Wistar albino rats (male; 240-260 g), acute pancreatitis was induced by an intraperitoneal injection of cerulein (50 μg/kg) administered twice in 2 h. They were equally divided into the following three groups: 0.9% isotonic solution (Group 1; control), everolimus once (Group 2), and everolimus twice (Group 3) by oral gavage after cerulein injection. Thirty hours after the induction of pancreatitis, blood samples were collected by direct intracardiac puncture, rats were sacrificed, and pancreatic tissue samples were obtained.

RESULTS

Biochemical analyses of the blood samples showed statistically significant difference in red blood cell count as well as hemoglobin, hematocrit, urea, and alanine transaminase levels among the study groups (p<0.05 in all). Everolimus proved to significantly increase red blood cell count in a dose-independent manner. Hemoglobin and hematocrit levels significantly increased only after treatment with one dose of everolimus. Urea level was significantly different between the Groups 2 and 3; however, no change was observed in both groups when compared with the control. Alanine transaminase level significantly decreased only after treatment with two doses of everolimus. Histopathological analyses revealed that everolimus significantly decreased inflammation and perivascular infiltrate in a dose-dependent manner (35% in Group 2, 75% in Group 3; p=0.048).

CONCLUSION

Treatment with two doses of everolimus improved some biochemical and histopathological parameters of experimental rat models of cerulein-induced acute pancreatitis and implied the specific inhibition of inflammatory response pathways.

Therapeutic effects of rat bone marrow-derived mesenchymal stem cells combined with Dachengqi decoction in rats with severe acute pancreatitis

AIM: To investigate the therapeutic effects of mesenchymal stem cells (MSCs) combined with Dachengqi decoction (DcqD) in rats with severe acute pancreatitis (SAP) and to explore the underlying mechanism.

METHODS: Sixty male Sprague-Dawley rats were randomly divided into sham-operated (SO), model-control (MC), MSCs-treatment (1.0 × 10⁶ MSCs; MSC group), DcqD-treatment (1 mL/100 g; DD group), and MSCs-plus-DcqD-treatment (MSCDD group) groups (n = 12). SAP was induced in rats by retrograde infusion of 1.5% sodium deoxycholate into the biliopancreatic duct. Isolation and culture of MSCs were performed by Percoll density gradient centrifugation and plastic adherence separating. Ahead of infusion, MSCs were labelled with DAPI via the tail vein. After 24 h of administration, distribution of MSCS in vivo was observed by fluorescence microscopy. Neutrophil apoptosis was identified by flow cytometry. Serum levels of amylase, lipase, tumour necrosis factor-α (TNF-α), interleukin (IL)-6, IL-10 and blood CD4⁺CD25⁺ regulatory T cells (CD4⁺CD25⁺Tregs) percentages were determined. Mortality, pathological changes in the pancreas, and histological scores were assessed.

RESULTS: The mortality rate of SAP rats was significantly lower in the treatment groups. Under a fluorescence microscope, the lumen tissue in the pancreatic sections of the MSC group exhibited bright blue fluorescence, whereas that in the MC group did not. Compared with the MC group, the MSC, DD and MSCDD groups had a significant decrease in TNF-α, IL-6, amylase, and lipase (P < 0.05). IL-10 and CD4⁺CD25⁺Tregs percentage were significantly higher in the MSCDD group than in the SAP, MSC and DD groups. However, there was no significant difference between the MSCDD and SO groups in IL-10 or CD4⁺CD25⁺Tregs percentage (P > 0.05). The pancreatic pathological changes and histopathologic scores were attenuated in the treatment groups, especially in the MSCDD group.

CONCLUSION: The combined therapy proved to be more effective than either MSC or DD alone and may cause synergistic effects in the early stage of SAP. The potential mechanisms that might account for the favourable effects include participating in injured pancreas repair, switching from neutrophils or acinar cell necrosis to apoptosis and inhibiting over-inflammatory reaction.

Role of high mobility group box-1 and protection of growth hormone and somatostatin in severe acute pancreatitis

In this study, we investigated the potential role of high-mobility group box 1 (HMGB1) in severe acute pancreatitis (SAP) and the effects of growth hormone (G) and somatostatin (S) in SAP rats. The rats were randomly divided into 6 groups of 20 each: sham-operated, SAP, SAP+saline, SAP+G, SAP+S and SAP+G+S. Ileum and pancreas tissues of rats in each group were evaluated histologically. HMGB1 mRNA expression was measured by reverse transcription-PCR. Levels of circulating TNF-α, IL-1, IL-6, and endotoxin were also measured. In the SAP group, interstitial congestion and edema, inflammatory cell infiltration, and interstitial hemorrhage occurred in ileum and pancreas tissues. The levels of HMGB1, TNF-α, IL-1, IL-6 and endotoxin were significantly up-regulated in the SAP group compared with those in the sham-operated group, and the 7-day survival rate was 0%. In the SAP+G and SAP+S groups, the inflammatory response of the morphological structures was alleviated, the levels of HMGB1, TNF-α, IL-1, IL-6, and endotoxin were significantly decreased compared with those in the SAP group, and the survival rate was increased. Moreover, in the SAP+G+S group, all histological scores were significantly improved and the survival rate was significantly higher compared with the SAP group. In conclusion, HMGB1 might participate in pancreas and ileum injury in SAP. Growth hormone and somatostatin might play a therapeutic role in the inflammatory response of SAP.

Time course of intestinal barrier function injury in a sodium taurocholate-induced severe acute pancreatitis in rat model

OBJECTIVE

The aims of this study were to clarify the kinetics of intestinal barrier function impairment in sodium taurocholate-induced severe acute pancreatitis (SAP) models and to explore an appropriate concentration of sodium taurocholate and a suitable time point for further study.

METHODS

In total, 104 rats were randomly divided into four groups: the normal control group (n = 8) receiving no treatment, the sham-operation group (n = 32), the 2.5% and 5% sodium taurocholate-treated SAP groups (n = 32 for each group) which were induced via a retrograde injection of 2.5% or 5% sodium taurocholate into the pancreatic duct. Histological examination, serum D-lactate and endotoxin levels and the incidence of bacteria translocation were recorded to assess the intestinal mucosal injury.

RESULTS

Pancreatitis models were successfully established in both the 2.5% and 5% sodium taurocholate-treated groups. The dosage of sodium taurocholate used to induce pancreatitis was positively correlated with the degree of intestinal mucosal injury. The most severe damage to intestinal barrier was observed 24 h after surgery in the 2.5% sodium taurocholate-treated group and 48 h after surgery in the 5% sodium taurocholate-treated group, respectively.

CONCLUSION

Based on the success rate of the model, the mortality and the impairment of intestinal barrier function, we conclude that 24 h after a retrograde injection of 2.5% sodium taurocholate may be the most appropriate time point to study intestinal barrier injury in SAP rats.

Berberine ameliorates severe acute pancreatitis‑induced intestinal barrier dysfunction via a myosin light chain phosphorylation‑dependent pathway

Berberine is a traditional drug used to treat gastrointestinal disorders in China and has been demonstrated to attenuate intestinal barrier dysfunction in certain animal models. However, the effects of berberine on pancreatitis-induced intestinal barrier dysfunction are yet to be fully elucidated. This study aimed to investigate the effect of berberine pretreatment on the attenuation of intestinal barrier dysfunction induced by severe acute pancreatitis (SAP). A total of 36 rats were randomly divided into Sham, SAP and SAP plus berberine groups. Pancreatitis was induced using retrograde injection of 3% Na-taurocholate into the pancreatic duct. Histological examinations of the pancreas were performed and intestinal barrier dysfunction was characterized by histological measurements and the assessment of serum diamine oxidase activity and endotoxin levels. Zonula occludens-1 and occludin mRNA and protein expression, as well as myosin light chain (MLC) phosphorylation, were assessed. SAP rat models were successfully established. Berberine treatment was found to have no significant effect on the histological changes in the pancreas, but was observed to ameliorate the intestinal mucosal barrier damage and membrane permeability associated with SAP. Although berberine exerted minimal effects on tight junction proteins in the ilea of SAP rats, it was observed to significantly inhibit SAP-induced MLC phosphorylation. To the best of our knowledge, this is the first study to demonstrate that berberine attenuates SAP‑induced intestinal barrier dysfunction in vivo. In addition, this study shows that the effect of berberine on intestinal barrier function may be associated with the inhibition of SAP‑induced upregulation of MLC phosphorylation.

Effect of umbilical cord mesenchymal stem cells on treatment of severe acute pancreatitis in rats

BACKGROUND AIMS

The aim of this study was to investigate the effect of umbilical cord mesenchymal stem cells (UCMSCs) on severe acute pancreatitis (SAP) in rats.

METHODS

SAP was established in rats by retrograde pancreatic duct injection of sodium taurocholate. In one group, 5 × 10(6) cells/kg of UCMSC suspension was injected into the tail vein 0 h, 1 h, 6 h and 12 h after the induction of SAP. In other groups, different doses of UCMSC suspension (5 × 10(4) cells/kg, 5 × 10(5) cells/kg, 5 × 10(6) cells/kg or 1 × 10(7) cells/kg) were administered at 1 h. Serum amylase was assayed at 12 h. Mortality, ascites, serum tumor necrosis factor-α, interferon-γ (assayed using enzyme-linked immunosorbent assay) and the wet-dry weight of the pancreas gland were assessed at 48 h. Pathologic changes of pancreatic and pulmonary tissues were observed.

RESULTS

Mortality in rats receiving 5 × 10(6) cells/kg of UCMSCs at 0 h was 10% compared with 58% in the SAP control group. Ascites, serum amylase and wet-dry pancreatic weight significantly decreased, and production of tumor necrosis factor-α and interferon-γ were reduced. Pathologic injuries of pancreatic and pulmonary tissues were markedly alleviated. Administration of UCMSCs (5 × 10(5) cells/kg, 5 × 10(6) cells/kg or 1 × 10(7) cells/kg) at 1 h or 5 × 10(6) cells/kg at 6 h significantly reduced the severity of SAP. The effect was less marked at 12 h and with lower concentrations of UCMSCs.

CONCLUSIONS

UCMSCs significantly decreased pancreatic injury caused by SAP in a time-dependent and dose-dependent way.

High-dose versus low-dose octreotide in the treatment of acute pancreatitis: a randomized controlled trial

To evaluate the therapeutic efficacy of high-dose octreotide in patients with predicted severe acute pancreatitis (SAP) or SAP, two hundred and thirty-six patients with predicted SAP and 136 patients with SAP were randomized into control, high-dose octreotide (High-O) and low-dose octreotide (Low-O) groups. In addition to the conventional managements administrated in control group, High-O group received an intravenous infusion of octreotide at 50 μg/h × 3d + 25 μg/h × 4d, and Low-O group received octreotide at 25 μg/h × 7d. The major primary outcomes included the numbers of predicted SAP patients which developed SAP after intervention and the number of patients with SAP amelioration. Secondary outcomes included APACHE II, SIRS scores, plasma levels of somatostatin (SST), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). There were no significant differences between the control and Low-O groups in terms of prevention and treatment for SAP. The incidence of SAP in patients with predicted SAP who received High-O was significantly lower than the Low-O group: 37.5% vs. 59.8%, p=0.005. Compared with Low-O group, the number of SAP patients in the SAP arm in the High-O group was reduced by 29.8%. Plasma levels of SST in both predicted SAP and the SAP patients were efficiently recovered (from 132.71±31.40 pg/ml to 180.00±23.50 pg/ml, p<0.05) after high-dose octreotide supplementation, which concomitantly reduced TNF-α and IL-6 levels. High-dose octreotide administration within 48h after AP onset may efficiently reduce the risk of SAP developing and partly attenuate SAP through raising plasma SST to a normal level and decreasing IL-6 and TNF-α.

Prevention effects of ND-07, a novel drug candidate with a potent antioxidative action and anti-inflammatory action, in animal models of severe acute pancreatitis

Oxidative stress and inflammation both play major roles in the development of the acute pancreatitis. Currently, a pancreatic enzyme inhibitor with limited efficacy is only clinically available in a few countries, and antioxidants or non-steroidal anti-inflammatory drugs (NSAIDs) provide only partial tissue protection in acute pancreatitis animal models. Here, we introduce a new drug candidate for treating acute pancreatitis named ND-07 [chemical name: 2-acetoxy-5-(2-4-(trifluoromethyl)-phenethylamino)-benzoic acid] that exhibits both potent antioxidative and anti-inflammatory activities. In an electron spin resonance (ESR) study, ND-07 almost blocked hydroxyl radical generation as low as 0.05 μM and significantly suppressed DNA oxidation and cell death in a lipopolysaccharide (LPS)-stimulated pancreatic cell line. In a cerulein plus LPS-induced acute pancreatitis model, ND-07 pretreatment showed significant tissue protective effects, with reductions of serum amylase and lipase levels and pancreatic wet weights. ND-07 not only diminished the plasma levels of malondialdehyde (MDA) and nitric oxide but also significantly decreased prostaglandin E₂ (PGE₂) and expression of tumor necrotizing factor-alpha (TNF-α) in the pancreatic tissue. In a severe acute necrotizing pancreatitis model induced by a choline deficient, ethionine-supplemented (CDE) diet, ND-07 dramatically protected the mortality even without any death, providing attenuation of pancreas, lung, and liver damages as well as the reductions in serum levels of lactate dehydrogenase (LDH), amylase and lipase, MDA levels in the plasma and pancreatic tissues, plasma levels of TNF-α, and interleukin-1 (IL-1β). These findings suggest that current dual synergistic action mechanisms of ND-07 might provide a superior protection for acute pancreatitis than conventional drug treatments.

Differential roles of inflammatory cells in pancreatitis

The incidence of acute pancreatitis per 100,000 of population ranges from 5 to 80. Patients suffering from hemorrhagic-necrotizing pancreatitis die in 10-24% of cases. 80% of all cases of acute pancreatitis are etiologically linked to gallstone disease immoderate alcohol consumption. As of today no specific causal treatment for acute pancreatitis exists. Elevated C-reactive protein levels above 130,mg/L can also predict a severe course of acute pancreatitis. The essential medical treatment for acute pancreatitis is the correction of hypovolemia. Prophylactic antibiotics should be restricted to patients with necrotizing pancreatitis, infected necrosis or other infectious complications. However, as premature intracellular protease activation is known to be the primary event in acute pancreatitis. Severe acute pancreatitis is characterized by an early inflammatory immune response syndrome (SIRS) and a subsequent compensatory anti-inflammatory response syndrome (CARS) contributing to severity as much as protease activation does. CARS suppresses the immune system and facilitates nosocomial infections including infected pancreatic necrosis, one of the most feared complications of the disease. A number of attempts have been made to suppress the early systemic inflammatory response but even if these mechanisms have been found to be beneficial in animal models they failed in daily clinical practice.

Protective effect of clodronate-containing liposomes on intestinal mucosal injury in rats with severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) can result in intestinal mucosal injury. This study aimed to demonstrate the protective effect of clodronate-containing liposomes on intestinal mucosal injury in rats with SAP.

METHODS

Liposomes containing clodronate or phosphate buffered saline (PBS) were prepared by the thin-film method. SAP models were prepared by a uniform injection of sodium taurocholate (2 mL/kg body weight) into the subcapsular space of the pancreas. Sprague-Dawley rats were randomly divided into a control group (C group), a SAP plus PBS-containing liposomes group (P group) and a SAP plus clodronate-containing liposomes group (T group). At 2 and 6 hours after the establishment of SAP models, 2 mL blood samples were taken from the superior mesenteric vein to measure the contents of serum TNF-alpha and IL-12. Pathological changes in the intestine and pancreas were observed using hematoxylin and eosin staining, while apoptosis was detected using TUNEL staining. In addition, the macrophage markers cluster of differentiation 68 (CD68) in the intestinal tissue was assessed with immunohistochemistry.

RESULTS

At the two time points, the levels of TNF-alpha and IL-12 in the P group were higher than those in the C group (P<0.05). Compared with the P group, the levels of TNF-alpha and IL-12 decreased in the T group (P<0.05). The pathological scores of the intestinal mucosa and pancreas in the T group were lower than those of the P group. In the T group, large numbers of TUNEL-positive cells were observed, but none or few in the C and P groups. The number of CD68-positive macrophages decreased in the T group.

CONCLUSIONS

Clodronate-containing liposomes have protective effects against intestinal mucosal injury in rats with SAP. The blockade of macrophages may provide a novel therapeutic strategy in SAP.

Clodronate-containing liposomes attenuate lung injury in rats with severe acute pancreatitis

OBJECTIVES

Severe acute pancreatitis (SAP) can lead to acute lung injury (ALI). The purpose of this paper is to investigate the protective effect of clodronate-containing liposomes on ALI in rats with SAP.

METHODS

The thin film method was used to prepare liposomes. Sprague-Dawley rats were randomly divided into three groups. After the SAP model was established by injecting 5% (w/v) sodium taurocholate (2 ml/kg body weight) into the subcapsular space of the pancreata, normal saline was administered to the control (C) group, phosphate buffer solution (PBS)-containing liposome to the P group, and clodronate-containing liposome to the T group through tail veins. Blood samples were obtained from the superior mesenteric vein at 2 and 6 h to measure the levels of amylase, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Morphological changes in the pancreata and lung were observed using hematoxylin and eosin (H&E) staining, while cell apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). In addition, the macrophage marker cluster of differentiation 68 (CD68) in lung tissue was detected with immunohistochemistry.

RESULTS

Blood levels of amylase, IL-6, and TNF-α were significantly increased in the P group compared to those in the T group (P<0.05). In the T group, large numbers of TUNEL-positive cells were observed, but no or few in the C and P groups. Gross inspection and H&E staining of pancreata and lung showed dramatic tissue damage, including inflammation and necrosis in the P group. Less remarkable changes were noted in the T group, and the C group exhibited normal histology. The histological scores according to Kaiser's criteria were consistent with H&E findings. The number of CD68-positive macrophages decreased in the T group.

CONCLUSIONS

Clodronate-containing liposomes have a protective effect against ALI in rats with SAP. Blockade of macrophages may represent a novel therapeutic strategy in SAP.

Human bone marrow-derived clonal mesenchymal stem cells inhibit inflammation and reduce acute pancreatitis in rats

BACKGROUND & AIMS

Acute pancreatitis (AP) has a high mortality rate; repetitive AP induces chronic AP and pancreatic adenocarcinoma. Mesenchymal stem cells (MSCs) have immunoregulatory effects and reduce inflammation. We developed a protocol to isolate human bone marrow-derived clonal MSCs (hcMSCs) from bone marrow aspirate and investigated the effects of these cells in rat models of mild and severe AP.

METHODS

Mild AP was induced in Sprague-Dawley rats by 3 intraperitoneal injections of cerulein (100 μg/kg), given at 2-hour intervals; severe AP was induced by intraparenchymal injection of 3% sodium taurocholate solution. hcMSCs were labeled with CM-1,1'-dioctadecyl-3,3,3'-tetramethylindo-carbocyanine perchloride and administered to rats through the tail vein.

RESULTS

hcMSCs underwent self-renewal and had multipotent differentiation capacities and immunoregulatory functions. Greater numbers of infused hcMSCs were detected in pancreas of rats with mild and severe AP than of control rats. Infused hcMSCs reduced acinar-cell degeneration, pancreatic edema, and inflammatory cell infiltration in each model of pancreatitis. The hcMSCs reduced expression of inflammation mediators and cytokines in rats with mild and severe AP. hcMSCs suppressed the mixed lymphocyte reaction and increased expression of Foxp3(+) (a marker of regulatory T cells) in cultured rat lymph node cells. Rats with mild or severe AP that were given infusions of hcMSCs had reduced numbers of CD3(+) T cells and increased expression of Foxp3(+) in pancreas tissues.

CONCLUSIONS

hcMSCs reduced inflammation and damage to pancreatic tissue in a rat model of AP; they reduced levels of cytokines and induced numbers of Foxp3(+) regulatory T cells. hcMSCs might be developed as a cell therapy for pancreatitis.

Effect of pentoxifylline and/or alpha lipoic acid on experimentally induced acute pancreatitis

Acute pancreatitis is a sudden inflammation of the pancreas that may be life threatening disease with high mortality rates; particularly in presence of systemic inflammatory response and multiple organ failure despite of the conventional antibiotic and symptomatic treatment. Oxidative stress has been shown to be involved in the pathophysiology of acute pancreatitis. This study was designed to investigate the possible effect of pentoxifylline and alpha lipoic acid respectively and in combination on rats with L-arginine induced acute pancreatitis. Rats were divided as follow; Group 1: served as control, Group 2 and Group 3: sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis by L-arginine 250 mg/100g, Group 4 and Group 5: rats treated by pentoxifylline (12 mg/kg) and sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis, Group 6 and Group 7: treated by alpha lipoic acid (1mg/kg) and sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis, Group 8 and Group 9: treated by pentoxifylline and alpha lipoic acid and sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis. Serum samples were collected to assay levels of amylase enzyme, C-reactive protein, IL-6, catalase enzyme activity, malondialdehyde and pancreases were excised for histopathological examination and assay of pancreatic myeloperoxidase. L-arginine induced-acute pancreatitis was evident by increased in serum marker enzymes and by histopathological findings compared to control group. Pentoxifylline and alpha lipoic acid respectively provided protection against L-arginine induced acute pancreatitis possibly by their antioxidant and anti-inflammatory effect. Treatment with alpha lipoic acid exhibited pronounced improvement in the course of pancreatitis when compared to treatment with pentoxifylline. Moreover, the combination of pentoxifylline and alpha lipoic acid offered the most evident protection when compared to groups that received monotherapy; pointing to the effectiveness of such combination therapy.

Role of high-mobility group box 1 protein in the pathogenesis of intestinal barrier injury in rats with severe acute pancreatitis

OBJECTIVE

To investigate the role of high-mobility group box 1 (HMGB1) in the development of intestinal barrier injury of severe acute pancreatitis (SAP) and to examine the effect of ethyl pyruvate (EP) on intestinal inflammation in rats with SAP.

METHODS

Rats were randomly divided into the following experimental groups: control, SAP, and EP treated. Then, the distal ileum was harvested for morphological studies, streptavidin-peroxidase immunohistochemistry examination, and Western blot analysis. The concentrations of plasma amylase, endotoxin, and diamine oxidase (DAO) and the activity of myeloperoxidase (MPO) in the intestine were determined.

RESULTS

We found that the expression of HMGB1 was up-regulated in the ileal mucosa within 6 hours and then remained elevated for more than 48 hours after SAP. Meanwhile, the levels of plasma amylase, endotoxin, and DAO and the activity of MPO in the intestinal mucosa were rapidly increased after SAP. Whereas treatment with EP significantly decreased the expression of intestinal HMGB1, the levels of plasma amylase, endotoxin, and DAO ameliorated the activity of MPO in the intestine in SAP rats.

CONCLUSIONS

Our results demonstrate that HMGB1 participates in intestinal barrier injury in SAP and EP might play a therapeutic role in intestinal inflammation in this SAP model.

Advances in managing acute pancreatitis

This review highlights advances in acute pancreatitis (AP) made in the past year. We focus on clinical aspects of AP - severe disease especially - and risk stratification tools to guide the clinical care of patients. Most patients with AP have mild disease that requires a diagnostic evaluation, self-limited supportive care, and a short hospital stay. In patients with potentially severe AP, it is important for clinicians to use available risk-stratifying tools to identify high-risk patients and initiate timely interventions such as aggressive fluid resuscitation, close monitoring, early initiation of enteral nutrition, and appropriate use of endoscopic retrograde cholangio-pancreatography. This approach decreases morbidity and possibly mortality and is supported by evidence drawn from recent clinical guidelines, historical literature, and the highest quality studies published in the last year.

Alcohol use and cigarette smoking as risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis

BACKGROUND & AIMS

Alcohol use and cigarette smoking are associated with various pancreatic diseases, but it is not known whether they associate with post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). We performed a retrospective case-control study to determine if these activities increase the risk of PEP.

METHODS

We identified 7638 patients who had undergone ERCP in the University of Michigan Health System and applied exclusion criteria to identify 123 with PEP. We randomly selected 308 age- and sex-stratified controls (2.5-fold case sample); after applying exclusion criteria 248 remained. In a masked fashion, we collected data for alcohol use, cigarette smoking, and 5 internal control variables: suspected sphincter of Oddi dysfunction (SOD), pancreatic sphincterotomy, moderate/difficult cannulation, 2 or more pancreatic injections, and pancreatic stent placement.

RESULTS

The univariate model showed an increased frequency of PEP in current drinkers (P < .001), former drinkers (P < .001), and former smokers (P < .001), as well as patients who were suspected of having SOD (P < .001), had undergone pancreatic sphincterotomy (P < .001), had a moderate/difficult cannulation (P = .001), and/or had 2 or more pancreatic injections (P = .007). The frequency of PEP was reduced in current smokers (P < .001). The multivariate model showed that the only independent significant predictors of PEP were current drinking (odds ratio [OR], 4.70; 95% confidence interval [CI], 2.60-8.50; P < .0001), former cigarette smoking (OR, 3.29; 95% CI, 1.28-8.44; P < .013), suspected SOD (OR, 3.69; 95% CI, 1.94-7.02; P < .001), and pancreatic sphincterotomy (OR, 5.91; 95% CI, 2.04-17.14; P = .001).

CONCLUSIONS

Current alcohol use and potentially former cigarette smoking are new risk factors for PEP. It is important to consider these variables in designing PEP prevention trials.

Study on protecting effects of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis

AIM: To investigate the protective effects and mechanisms of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis (SAP).

METHODS: The SAP rat models were prepared and randomly assigned to the model control group, Baicalin treated group, and Octreotide treated group while other healthy rats were assigned to the sham-operated group. Rat mortality, levels of ALT, AST, liver and pancreas pathological changes in all groups were observed at 3, 6 and 12 h after operation. Tissue microarray (TMA) sections of hepatic tissue were prepared to observe expression levels of Bax, Bcl-2 protein and Caspase-3, and changes of apoptotic indexes.

RESULTS: Rat survival at 12 h, expression levels of Bax, Caspase-3 protein and apoptotic indexes of liver were all significantly higher in treated groups than in model control group. While the liver and pancreas pathological scores, contents of ALT, AST, and expression levels of Bcl-2 protein were all lower in treated groups than in the model control group.

CONCLUSION: Both Baicalin and Octreotide can protect rats with SAP by decreasing the contents of ALT, AST and expression levels of Bcl-2 protein, and improving the expression levels of Bax protein, Caspase-3 protein, and inducing apoptosis.

Delayed ethyl pyruvate therapy attenuates experimental severe acute pancreatitis via reduced serum high mobility group box 1 levels in rats

AIM: To investigate the effect of delayed ethyl pyruvate (EP) delivery on distant organ injury, survival time and serum high mobility group box 1 (HMGB1) levels in rats with experimental severe acute pancreatitis (SAP).

METHODS: A SAP model was induced by retrograde injection of artificial bile into the pancreatic ducts of rats. Animals were divided randomly into three groups (n = 32 in each group): sham group, SAP group and delayed EP treatment group. The rats in the delayed EP treatment group received EP (30 mg/kg) at 12 h, 18 h and 30 h after induction of SAP. Animals were sacrificed, and samples were obtained at 24 h and 48 h after induction of SAP. Serum HMGB1, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine (Cr) levels were measured. Lung wet-to-dry-weight (W/D) ratios and histological scores were calculated to evaluate lung injury. Additional experiments were performed between SAP and delayed EP treatment groups to study the influence of EP on survival times of SAP rats.

RESULTS: Delayed EP treatment significantly reduced serum HMGB1 levels, and protected against liver, renal and lung injury with reduced lung W/D ratios (8.22 ± 0.42 vs 9.76 ± 0.45, P < 0.01), pulmonary histological scores (7.1 ± 0.7 vs 8.4 ± 1.1, P < 0.01), serum AST (667 ± 103 vs 1 368 ± 271, P < 0.01), ALT (446 ± 91 vs 653 ± 98, P < 0.01) and Cr (1.2 ± 0.3 vs 1.8 ± 0.3, P < 0.01) levels. SAP rats had a median survival time of 44 h. Delayed EP treatment significantly prolonged median survival time to 72 h (P < 0.01).

CONCLUSION: Delayed EP therapy protects against distant organ injury and prolongs survival time via reduced serum HMGB1levels in rats with experimental SAP. EP may potentially serve as an effective new therapeutic option against the inflammatory response and multiple organ dysfunction syndrome (MODS) in SAP patients.

Pharmacological approach to acute pancreatitis

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

Nitric oxide pathways and evidence-based perturbations in acute pancreatitis

Nitric oxide (NO) is a gaseous neurotransmitter, a vasodilator and paracrine regulator. In the pancreas, NO regulates normal pancreatic exocrine secretion, endocrine pancreatic insulin secretion and pancreatic microvascular blood flow. NO has multiple species and is produced de novo by 3 NO synthase enzymes. Endothelial NO synthase reduces the severity of the initial phase of experimental acute pancreatitis (AP). Cigarette smoking and chronic alcohol use disrupt normal NO pathways and are associated with pancreatitis and pancreatic cancer. The aims of this minireview are to describe normal intrapancreatic NO pathways, perturbations during experimental AP and due to epidemiological factors associated with pancreatic pathology, and the clinical implications of NO on AP.