Differential roles of inflammatory cells in pancreatitis

From pancreas to lungs: The role of immune cells in severe acute pancreatitis and acute lung injury

BACKGROUND

Severe acute pancreatitis (SAP) is a potentially lethal inflammatory pancreatitis condition that is usually linked to multiple organ failure. When it comes to SAP, the lung is the main organ that is frequently involved. Many SAP patients experience respiratory failure following an acute lung injury (ALI). Clinicians provide insufficient care for compounded ALI since the underlying pathophysiology is unknown. The mortality rate of SAP patients is severely impacted by it.

OBJECTIVE

The study aims to provide insight into immune cells, specifically their roles and modifications during SAP and ALI, through a comprehensive literature review. The emphasis is on immune cells as a therapeutic approach for treating SAP and ALI.

FINDINGS

Immune cells play an important role in the complicated pathophysiology ofSAP and ALI by maintaining the right balance of pro- and anti-inflammatory responses. Immunomodulatory drugs now in the market have low thepeutic efficacy because they selectively target one immune cell while ignoring immune cell interactions. Accurate management of dysregulated immune responses is necessary. A critical initial step is precisely characterizing the activity of the immune cells during SAP and ALI.

CONCLUSION

Given the increasing incidence of SAP, immunotherapy is emerging as a potential treatment option for these patients. Interactions among immune cells improve our understanding of the intricacy of concurrent ALI in SAP patients. Acquiring expertise in these domains will stimulate the development of innovative immunomodulation therapies that will improve the outlook for patients with SAP and ALI.

Comprehensive Review of Surgical and Radiological Management of Hemorrhagic Pancreatitis: Current Strategies and Outcomes

Hemorrhagic pancreatitis, a severe complication of acute and chronic pancreatitis, involves bleeding due to vascular disruptions. This condition presents significant clinical challenges and is associated with high morbidity and mortality. The bleeding can result from arterial or venous complications, often exacerbated by inflammatory and enzymatic damage to blood vessels within the pancreas. Patients with hemorrhagic pancreatitis may experience symptoms such as abdominal pain, nausea, vomiting, and gastrointestinal bleeding. Diagnostic imaging, including CT and MRI, is crucial in identifying the source of bleeding and guiding treatment decisions. Management strategies have evolved over the past two decades, shifting from purely surgical approaches to including interventional radiology techniques. Surgical intervention is often reserved for hemodynamically unstable patients or those with large pseudoaneurysms, offering definitive treatment but carrying higher risks of complications. Endovascular techniques, such as transcatheter embolization, provide a less invasive alternative with high success rates and shorter recovery times, though rebleeding may occur. Treatment choice depends on various factors, including the patient's stability, the size and location of the bleeding, and the availability of specialized expertise. Overall, the management of hemorrhagic pancreatitis requires a multidisciplinary approach, combining surgical and radiological techniques to optimize patient outcomes and reduce the risk of mortality. Long-term follow-up is essential to monitor for recurrent disease and manage the metabolic consequences of pancreatic insufficiency.

Redefining Immune Dynamics in Acute Pancreatitis: The Protective Role of Galectin-3 Deletion and Treg Cell Enhancement

Acute pancreatitis (AP) is a complex inflammatory condition that can lead to systemic inflammatory responses and multiple organ dysfunction. This study investigates the role of Galectin-3 (Gal-3), a β-galactoside-binding lectin, in modulating acquired immune responses in AP. Acute pancreatitis was induced by ligation of the bile-pancreatic duct in wild-type and Galectin-3-deficient C57BL/6 mice. We determined the phenotypic and molecular features of inflammatory cells, serum concentrations of amylase, pancreatic trypsin activity, and pancreatic and lung pathology. Galectin-3 deficiency decreased the total number of CD3+CD49- T cells and CD4+ T helper cells, downregulated the production of inflammatory cytokine and IFN-γ, and increased the accumulation of IL-10-producing Foxp3+ T regulatory cells and regulatory CD4+ T cells in the pancreata of diseased animals. The deletion of Galectin-3 ameliorates acute pancreatitis characterized by lowering serum amylase concentration and pancreatic trypsin activity, and attenuating of the histopathology of the lung. These findings shed light on the role of Galectin-3 in acquired immune response in acute pancreatitis and identify Galectin-3 as an attractive target for investigation of the immunopathogenesis of disease and for consideration as a potential therapeutic target for patients with acute inflammatory disease of the pancreas.

PD-L1 blockade in mitigating severe acute pancreatitis induced pancreatic damage through modulation of immune cell apoptosis

Acute pancreatitis (AP) is a prevalent gastrointestinal disorder. The immune response plays a crucial role in AP progression. However, the impact of immune regulatory checkpoint PD-L1 on severe acute pancreatitis (SAP) remains uncertain. Hence, this study aimed to examine the influence of PD-L1 on SAP. We assessed PD-L1 expression in neutrophils and monocytes obtained from SAP patients. We induced SAP in C57BL/6J mice, PD-L1 gene-deficient mice, and PD-L1 humanized mice using intraperitoneal injections of cerulein plus lipopolysaccharide. Prior to the initial cerulein injection, a PD-L1 inhibitor was administered. Pancreatic tissues were collected for morphological and immunohistochemical evaluation, and serum levels of amylase, lipase, and cytokines were measured. Flow cytometry analysis was performed using peripheral blood cells. The expression of PD-L1 in neutrophils and monocytes was significantly higher in SAP patients compared to healthy individuals. Likewise, the expression of PD-L1 in inflammatory cells in the peripheral blood of SAP-induced C57BL/6J mice was notably higher than in the control group. In mice with PD-L1 deficiency, SAP model exhibited lower pancreatic pathology scores, amylase, lipase, and cytokine levels compared to wild-type mice. PD-L1 deletion resulted in reduced neutrophil apoptosis, leading to an earlier peak in neutrophil apoptosis. Furthermore, it decreased early monocyte apoptosis and diminished the peak of T lymphocyte apoptosis. Within the SAP model, administration of a PD-L1 inhibitor reduced pancreatic pathology scores, amylase, lipase, and cytokine levels in both C57BL/6J mice and PD-L1 humanized mice. These findings suggest that inhibiting PD-L1 expression can alleviate the severity of SAP.

Tryptophan metabolite norharman secreted by cultivated Lactobacillus attenuates acute pancreatitis as an antagonist of histone deacetylases

BACKGROUND

Patients with acute pancreatitis (AP) exhibit specific phenotypes of gut microbiota associated with severity. Gut microbiota and host interact primarily through metabolites; regrettably, little is known about their roles in AP biological networks. This study examines how enterobacterial metabolites modulate the innate immune system in AP aggravation.

METHODS

In AP, alterations in gut microbiota were detected via microbiomics, and the Lactobacillus metabolites of tryptophan were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). By culturing Lactobacillus with tryptophan, differential metabolites were detected by LC-MS/MS. Lipopolysaccharide (LPS)-stimulated RAW264.7 cells and mice with cerulein plus LPS-induced AP were used to evaluate the biological effect of norharman on M1 macrophages activation in AP development. Further, RNA sequencing and lipid metabolomics were used for screening the therapeutic targets and pathways of norharman. Confocal microscopy assay was used to detect the structure of lipid rafts. Molecular docking was applied to predict the interaction between norharman and HDACs. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) were used to explore the direct mechanism of norharman promoting Rftn1 expression. In addition, myeloid-specific Rftn1 knockout mice were used to verify the role of Rftn1 and the reversed effect of norharman.

RESULTS

AP induced the dysfunction of gut microbiota and their metabolites, resulting in the suppression of Lactobacillus-mediated tryptophan metabolism pathway. The Lactobacillus metabolites of tryptophan, norharman, inhibited the release of inflammatory factor in vitro and in vivo, as a result of its optimal inhibitory action on M1 macrophages. Moreover, norharman blocked multiple inflammatory responses in AP exacerbation due to its ability to maintain the integrity of lipid rafts and restore the dysfunction of lipid metabolism. The mechanism of norharman's activity involved inhibiting the enzyme activity of histone deacetylase (HDACs) to increase histone H3 at lysine 9/14 (H3K9/14) acetylation, which increased the transcription level of Rftn1 (Raftlin 1) to inhibit M1 macrophages' activation.

CONCLUSIONS

The enterobacterial metabolite norharman can decrease HDACs activity to increase H3K9/14 acetylation of Rftn1, which inhibits M1 macrophage activation and restores the balance of lipid metabolism to relieve multiple inflammatory responses. Therefore, norharman may be a promising prodrug to block AP aggravation.

The trigger for pancreatic disease: NLRP3 inflammasome

NLRP3 inflammasome is a multiprotein complex expressed in a variety of cells to stimulate the production of inflammatory factors. Activation of NLRP3 inflammasome depends on a complex regulatory mechanism, and its pro-inflammatory function plays an important role in pancreatic diseases. In this literature review, we summarize the activation mechanism of NLRP3 and analyze its role in each of the four typical pancreatic diseases. Through this article, we provide a relatively comprehensive summary to the researchers in this field, and provide some targeted therapy routes.

Monocytic HLA-DR Expression in Immune Responses of Acute Pancreatitis and COVID-19

Acute pancreatitis is a common gastrointestinal disease with increasing incidence worldwide. COVID-19 is a potentially life-threatening contagious disease spread throughout the world, caused by severe acute respiratory syndrome coronavirus 2. More severe forms of both diseases exhibit commonalities with dysregulated immune responses resulting in amplified inflammation and susceptibility to infection. Human leucocyte antigen (HLA)-DR, expressed on antigen-presenting cells, acts as an indicator of immune function. Research advances have highlighted the predictive values of monocytic HLA-DR (mHLA-DR) expression for disease severity and infectious complications in both acute pancreatitis and COVID-19 patients. While the regulatory mechanism of altered mHLA-DR expression remains unclear, HLA-DR^-/low monocytic myeloid-derived suppressor cells are potent drivers of immunosuppression and poor outcomes in these diseases. Future studies with mHLA-DR-guided enrollment or targeted immunotherapy are warranted in more severe cases of patients with acute pancreatitis and COVID-19.

Targeting and functional effects of biomaterials-based nanoagents for acute pancreatitis treatment

Acute pancreatitis (AP) is a severe life-threatening inflammatory disease showing primary characteristics of excessive inflammatory response and oxidative stress. Based on the pathophysiology of AP, several anti-inflammatory and anti-oxidative stress agents have been studied. However, the low accumulated concentrations and scattered biodistributions limit the application of these agents. With the development of nanotechnology, functional nanomaterials can improve the bioavailability of drugs and extend their half-life by reducing immunogenicity to achieve targeted drug delivery. The biomaterial-based carriers can mediate the passive or active delivery of drugs to the target site for improved therapeutic effects, such as anti-oxidation and anti-inflammation for AP treatment. Other biomaterials-based nanomedicine may exhibit different functions with/without targeting effects. In this review, we have summarized the targeting and functional effects of biomaterials-based nanoagents specifically for AP treatment.

Identification of novel immune-related targets mediating disease progression in acute pancreatitis

Introduction

Acute pancreatitis (AP) is an inflammatory disease with very poor outcomes. However, the order of induction and coordinated interactions of systemic inflammatory response syndrome (SIRS) and compensatory anti-inflammatory response syndrome (CARS) and the potential mechanisms in AP are still unclear.

Methods

An integrative analysis was performed based on transcripts of blood from patients with different severity levels of AP (GSE194331), as well as impaired lung (GSE151572), liver (GSE151927) and pancreas (GSE65146) samples from an AP experimental model to identify inflammatory signals and immune response-associated susceptibility genes. An AP animal model was established in wild-type (WT) mice and Tlr2-deficient mice by repeated intraperitoneal injection of cerulein. Serum lipase and amylase, pancreas impairment and neutrophil infiltration were evaluated to assess the effects of Tlr2 in vivo.

Results

The numbers of anti-inflammatory response-related cells, such as M2 macrophages (P = 3.2 × 10^-3), were increased with worsening AP progression, while the numbers of pro-inflammatory response-related cells, such as neutrophils (P = 3.0 × 10^-8), also increased. Then, 10 immune-related AP susceptibility genes (SOSC3, ITGAM, CAMP, FPR1, IL1R1, TLR2, S100A8/9, HK3 and MMP9) were identified. Finally, compared with WT mice, Tlr2-deficient mice exhibited not only significantly reduced serum lipase and amylase levels after cerulein induction but also alleviated pancreatic inflammation and neutrophil accumulation.

Discussion

In summary, we discovered SIRS and CARS were stimulated in parallel, not activated consecutively. In addition, among the novel susceptibility genes, TLR2might be a novel therapeutic target that mediates dysregulation of inflammatory responses during AP progression.

A Mini-Review of Diagnostic and Therapeutic Nano-Tools for Pancreatitis

Pancreatitis is an inflammatory reaction of pancreatic tissue digestion, edema, bleeding and even necrosis caused by activation of pancreatin due to various causes. In particular, patients with severe acute pancreatitis (SAP) often suffer from secondary infection, peritonitis and shock, and have a high mortality rate. Chronic pancreatitis (CP) can cause permanent damage to the pancreas. Due to the innate characteristics, structure and location of the pancreas, there is no effective treatment, only relief of symptoms. Especially, AP is an unpredictable and potentially fatal disease, and the timely diagnosis and treatment remains a major challenge. With the rapid development of nanomedicine technology, many potential tools can be used to address this problem. In this review, we have introduced the pathophysiological processes of pancreatitis to understanding its etiology and severity. Most importantly, the current progress in the diagnosis and treatment tools of pancreatitis based on nanomedicine is summarized and prospected.

Cdk2 suppresses IL-23 expression and the onset of severe acute pancreatitis

BACKGROUND

Acute pancreatitis is a sudden inflammation of the pancreas. Although interleukin-23 (IL-23) is associated with the severity of acute pancreatitis, the underlying mechanism remains largely unknown. Herein, its regulatory mechanisms were explored in this study.

METHODS

RNA-sequencing analysis selected the differently expressed genes in cerulean-induced acute pancreatitis mice. Polymerase chain reaction analysis determined IL-23 expression in cyclin-dependent kinase 2 (Cdk2) short hairpin RNA (shRNA)-pretreated or DDB1-cullin-4-associated factor-2 (DCAF2)-overexpressed RAW264.7 cells or CDKs inhibitor AT7519/cullin ring-finger ubiquitin ligase inhibitor MLN4924-treated bone marrow-derived macrophages in the presence of lipopolysaccharides (LPS). Pancreatic damages were evaluated in AT7519-treated pancreatitis mice.

RESULTS

Pancreatitis mice displayed an increased expression on IL-23 and a decreased expression of Cdk2. Inhibiting Cdk2 by shRNA or AT7519 significantly induced IL-23 expression in LPS-treated RAW cells. Moreover, AT7519 treatment significantly aggravated the severity of acute pancreatitis in mice. Furthermore, AT7519 remarkably increased DCAF2 expression, which was also induced by MLN4924 no matter with or without AT7519 in vitro. On the contrary, overexpressing DCAF2 blocked the stimulatory effect of AT7519 on IL-23 expression.

CONCLUSION

Cdk2 negatively regulates IL-23 expression by inhibiting DCAF2 in acute pancreatitis, indicating that Cdk2 might serve as a promising therapeutic target for acute pancreatitis.

Chemokine receptor 8 expression may be linked to disease severity and elevated interleukin 6 secretion in acute pancreatitis

BACKGROUND

Acute pancreatitis (AP) is an inflammatory disease, which presents with epigastric pain and is clinically diagnosed by amylase and lipase three times the upper limit of normal. The 2012 Atlanta classification stratifies the severity of AP as one of three risk categories namely, mild AP (MAP), moderately severe AP (MSAP), and severe AP (SAP). Challenges in stratifying AP upon diagnosis suggest that a better understanding of the underlying complex pathophysiology may be beneficial.

AIM

To identify the role of the chemokine receptor 8 (CCR8), expressed by T-helper type-2 Lymphocytes and peritoneal macrophages, and its possible association to Interleukin (IL)-6 and AP stratification.

METHODS

This study was a prospective case-control study. A total of 40 patients were recruited from the Chris Hani Baragwanath Academic Hospital and the Charlotte Maxeke Johannesburg Academic Hospital. Bioassays were performed on 29 patients (14 MAP, 11 MSAP, and 4 SAP) and 6 healthy controls as part of a preliminary study. A total of 12 mL of blood samples were collected at Day (D) 1, 3, 5, and 7 post epigastric pain. Using multiplex immunoassay panels, real-time polymerase chain reaction (qRT-PCR) arrays, and multicolour flow cytometry analysis, immune response-related proteins, genes, and cells were profiled respectively. GraphPad Prism™ software and fold change (FC) analysis was used to determine differences between the groups. P<0.05 was considered significant.

RESULTS

The concentration of IL-6 was significantly different at D3 post epigastric pain in both the MAP group and MSAP group with P = 0.001 and P = 0.013 respectively, in a multiplex assay. When a FC of 2 was applied to identify differentially expressed genes using RT² Profiler, CCR8 was shown to increase steadily with disease severity from MAP (1.33), MSAP (38.28) to SAP (1172.45) median FC. Further verification studies using RT-PCR showed fold change increases of CCR8 in MSAP and SAP ranging from 1000 to 1000000 times when represented as Log₁₀, compared to healthy control respectively at D3. The findings also showed differing lymphocyte and monocyte cell frequency between the groups. With monocyte population frequency as high as 70% in MSAP at D3.

CONCLUSION

The higher levels of CCR8 and IL-6 in the severe patients and immune cell differences compared to MAP and controls provide an avenue for exploring AP stratification to improve management.

[Interventional endoscopic treatment in acute pancreatitis]

BACKGROUND

Acute pancreatitis (AP) represents a frequent gastrointestinal diseases. Approximately 80% of patients have a mild course of the disease and conservative treatment is sufficient; however, 20% of patients develop a severe AP with local and systemic complications. This article focuses on the currently recommended endoscopic management of severe AP.

OBJECTIVE

Classification of AP by the revised Atlanta classification and the occurrence of local or systemic complications. Summary of current evidence with respect to endoscopic management.

MATERIAL AND METHODS

Inspection of the current literature from specialist journals and current guidelines.

RESULTS

The AP is classified as mild, moderate or severe based on systemic (hypotension, renal failure, lung failure) and/or local complications, such as acute peripancreatic fluid collections (APFC), peripancreatic pseudocysts (PPC), acute necrotic collections (ANC) and walled-off necrosis (WON). In recent years the staged endoscopic treatment of infected ANC, WON and PPC has become established. The initial step is the endoscopic ultrasound-guided puncture and drainage with plastic or lumen-apposing metal stents. For solid components or insufficient drainage, a transgastric endoscopic necrosectomy is recommended. The treatment of severe AP requires an interdisciplinary management in specialized centers and regular re-evaluation of the therapeutic efficacy.

CONCLUSION

Interventional endoscopy has become established as the standard for treatment of severe AP.

Da-Huang-Fu-Zi-Tang Ameliorates Severe Acute Pancreatitis by Elevation of M2 Kupffer Cells in Rats

Introduction

Severe acute pancreatitis (SAP) is a clinical emergency often accompanied by inflammatory response syndrome (SIRS), which eventually leads to acute lung injury and failure of other organs. The activation of liver Kupffer cells (KCs) plays a major role in the process of SIRS and multiorgan damage caused by SAP. Da-Huang-Fu-Zi-Tang (DHFZT), a traditional Chinese prescription, has been widely used for SAP in the clinic. The present study investigated the activation state of KCs in SAP and the potential mechanism of DHFZT.

Methods

A total of 24 Sprague Dawley rats were randomly assigned to four groups: SH (sham operation group + saline enema), SH-DHFZT (sham operation group + DHFZT enema), SAP (model group + saline enema), and SAP-DHFZT (model group + DHFZT enema). Blood samples were drawn from the abdominal aorta for measuring serum endotoxin, amylase, calcium ion, IL-1β, TNF-α, iNOS, and IL-10. Then, the pancreas, lung, liver, and ileum were harvested for histological observation, and the liver was used to detect the level of F4/80, CD86, and CD163 in KCs with immunohistochemistry and western blot.

Results

In the SAP group, the CD86+ KCs were significantly increased with a high level of IL-1β, TNF-α, and iNOS, and the organs were impaired. In the SAP-DHFZT group, CD163+ KCs were significantly increased with the high level of IL-10, and the damage to organs was alleviated.

Conclusion

These phenomena suggested that the SIRS and multiple organ damage in SAP might be related to the excessive activation of M1 KCs, and DHFZT might alleviate the SIRS by inducing the differentiation of KCs into the M2-type and promote the expression of anti-inflammatory factor IL-10.

Cathepsin B aggravates acute pancreatitis by activating the NLRP3 inflammasome and promoting the caspase-1-induced pyroptosis

OBJECTIVES

Cathepsin B (CTSB), nod-like receptor family pyrin domain-containing 3 (NLRP3), and caspase-1 play an important role in the development of Acute Pancreatitis (AP). Besides, the relationship between the proteins remains poorly understood. In addition, whereas previous studies have found caspase-1 activation in AP, pyroptosis, a caspase-1 induced cell death mode, has never been proposed and proved in AP.

METHODS

We induced AP in mice by intraperitoneal injection of cerulein. Mice in the inhibitor group of CTSB were pretreated with injection of CA-074me, while mice in the inhibitor group of caspase-1 were of Ac-YVAD-CHO, 1 h earlier. We evaluated the inflammation of the pancreas and the detected expression of activated CTSB, NLRP3, ASC, caspase-1p20, IL-1β and IL-18. TUNEL staining was used to detect acinar cell death.

RESULTS

The inflammation of the pancreas in the two inhibitor groups was significantly reduced compared with that in the AP group. We observed that CA-074me not only inhibits CTSB, but also suppresses the expression and activity of NLRP3, ASC and caspase-1. We found that CA-074me further inhibits the downstream event of caspase-1, including pro-inflammatory cytokine secretion and pyroptosis. Whereas Ac-YVAD-CHO inhibited caspase-1 and decreased pro-inflammatory cytokine secretion and pyroptosis, it did not down-regulate the expression and activity ofCTSB, NLRP3 and ASC.

CONCLUSION

The results indicate that CTSB may aggravate AP by activating the NLRP3 inflammasome and promoting Caspase-1-induced pyroptosis. These provide clues about the pathophysiological mechanisms of AP, shedding light on new ideas and potential targets for the prevention and treatment of AP.

Overexpression of miR-99a Alleviates Intestinal Mucosal Barrier Injury in Rats with Severe Acute Pancreatitis

Severe acute pancreatitis (SAP), which is characterized by acute onset and high mortality, is complicated with systemic inflammatory response syndrome. This study investigated the molecular mechanism underlying SAP-induced intestinal mucosal barrier injury. SAP was established in rats by retrograde injection of sodium taurocholate (STC) into biliopancreatic duct. Transfection of miR-99a mimic was conducted 24 h before the SAP establishment. Histological properties of pancreatic and intestinal tissues were observed by hematoxylin-eosin staining. The serum levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, procalcitonin (PCT), endotoxin (ET), and diamine oxidase (DAO) were measured by enzyme-linked immunosorbent assay. The expressions of miR-99a, NADPH oxidase (NOX)4, zonula occludens (ZO)-1, occludin, and claudin-1 in pancreatic and the intestinal tissue were determined by quantitative reverse transcription polymerase chain reaction or Western blot. STC injection damaged pancreatic and intestinal tissues of the rats. During the model construction, the serum levels of IL-1β, TNF-α, PCT, ET, and DAO were increased, whereas miR-99a expression in pancreatic and intestinal tissues of the rats was decreased. miR-99a mimic alleviated SAP-induced histological abnormality of pancreatic and intestinal tissues; moreover, it reversed the serum levels of IL-1β, TNF-α, PCT, ET, and DAO increased by SAP, decreased SAP-increased NOX4 expression and increased the expressions of ZO-1, occludin, and claudin-1 previously decreased by SAP in pancreatic and the intestinal tissues. Thus, overexpressed miR-99a could alleviate intestinal mucosal barrier injury in rats with SAP.

mTOR-Myc axis drives acinar-to-dendritic cell transition and the CD4+ T cell immune response in acute pancreatitis

The inflammatory response in acute pancreatitis (AP) is associated with acinar-to-dendritic cell transition. The CD4⁺ T-cell-mediated adaptive immune response is necessary for pancreatic inflammatory damage. However, the effect of acinar-to-dendritic cell transition on the CD4⁺ T-cell response and the regulatory mechanism remain undefined. A mouse animal model of AP was established by repeated intraperitoneal injection of CAE. The mTOR inhibitor rapamycin was administered before AP induction. Primary acinar cells were isolated and co-incubated with subsets of differentiated CD4⁺ T cells. The expression of DC-SIGN was also assessed in pancreatic tissues from human AP patients. We found acinar cells expressed DC-SIGN and displayed the phenotype of dendritic cells (DCs), which promoted the differentiation of naive CD4⁺ T cells into CD4⁺/IFN-γ⁺ Th1 and CD4⁺/IL-17A⁺ Th17 cells in pancreatic tissues during AP. DC-SIGN was the target gene of Myc. The mTOR inhibitor rapamycin inhibited AP-induced DC-SIGN expression, CD4⁺ Th1/Th17 cell differentiation and the pro-inflammatory response via Myc. Acinar cells expressed DC-SIGN in pancreatic tissues of human patients with AP. In conclusion, acinar-to-dendritic cell transition is implicated in the CD4⁺ T-cell immune response via mTOR-Myc-DC-SIGN axis, which might be an effective target for the prevention of local pancreatic inflammation in AP.

Circulating Lymphocyte Subsets Induce Secondary Infection in Acute Pancreatitis

Acute pancreatitis (AP) is considered a cascade of immune responses triggered by acinar cell necrosis. AP involves two main processes of systemic inflammatory response syndrome and subsequent compensatory anti-inflammatory response syndrome. Although great efforts have been made regarding AP therapy, the mortality rate of AP remains high. Secondary infection acts a lethal factor in AP. Lymphocytes act as major immune mediators in immune responses in the course of this disease. However, the relationship between lymphocytes and secondary infection in AP is unclear. This review summarizes the variation of lymphocytes and infection in AP. Knowledge of the characterization of circulating lymphocyte abnormalities is relevant for understanding the pathophysiology of AP.

Prevention of Severe Acute Pancreatitis With Cyclooxygenase-2 Inhibitors: A Randomized Controlled Clinical Trial

OBJECTIVES

Severe acute pancreatitis (SAP) is still a big challenge. Accumulated data showed that overexpression of cyclooxygenase-2 (COX-2) in acute pancreatitis and experimental pancreatitis could be attenuated with COX-2 inhibitors. This study was aimed to evaluate whether the occurrence of SAP could be prevented by selective COX-2 inhibitors.

METHODS

A total of 190 patients with predicted SAP were randomized into convention group or convention plus COX-2 inhibitors (C+COX-2-Is) group. Besides conventional treatment to all patients in 2 groups, parecoxib (40 mg/d intravenous injection for 3 days) and celecoxib (200 mg oral or tube feeding twice daily for 7 days) were sequentially administrated to the patients in the C+COX-2-Is group. The primary outcome was predefined as the occurrence of SAP. The serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) for all of the patients were measured.

RESULTS

The occurrence of SAP in the C+COX-2-Is group was decreased 47.08% compared with the convention group, 21.05% (20/95) vs 39.78% (37/93), P = 0.005. A reduction of late local complications was also shown in the C+COX-2-Is group, 18.95% (18/93) vs 34.41% (32/95), P = 0.016. The serum levels of IL-6 and TNF-α were significantly lower in the C+COX-2-Is group than those in the convention group, P < 0.05. Parecoxib relieved abdominal pain more rapidly and decreased the consumption of meperidine. An incremental reduction of cost for 1% decrease of SAP occurrence was RMB475.

DISCUSSION

Sequential administration of parecoxib and celecoxib in patients with predicted SAP obtained about half-reduction of SAP occurrence through decreasing serum levels of TNF-α and IL-6. This regimen presented good cost-effectiveness.

Current trends in pharmacological approaches for treatment and management of acute pancreatitis – a review

Objectives

Acute pancreatitis (AP) is an inimical disorder associated with overall mortality rates between 10-15%. It is a disorder of the exocrine pancreas which is characterized by local and systemic inflammatory responses primarily driven by oxidative stress and death of pancreatic acinar cells. The severity of AP ranges from mild pancreatic edema with complete recuperative possibilities to serious systemic inflammatory response resulting in peripancreatic/pancreatic necrosis, multiple organ failure, and death.

Key findings

We have retrieved the potential alternative approaches that are developed lately for efficacious treatment of AP from the currently available literature and recently reported experimental studies. This review summarizes the need for alternative approaches and combinatorial treatment strategies to deal with AP based on literature search using specific key words in PubMed and ScienceDirect databases.

Summary

Since AP results from perturbations of multiple signaling pathways, the so called “monotargeted smart drugs” of the past decade is highly unlikely to be effective. Also, the conventional treatment approaches were mainly involved in providing palliative care instead of curing the disease. Hence, many researchers are beginning to focus on developing alternate therapies to treat AP effectively. This review also summarizes the recent trends in the combinatorial approaches available for AP treatment.

NLRP3 Inflammasome Regulates Development of Systemic Inflammatory Response and Compensatory Anti-Inflammatory Response Syndromes in Mice With Acute Pancreatitis

BACKGROUND & AIMS

Pancreatitis starts with primarily sterile local inflammation that induces systemic inflammatory response syndrome, followed by compensatory anti-inflammatory response syndrome (CARS). We investigated the mechanisms of these processes in mice and human serum.

METHODS

We induced severe acute pancreatitis by partial duct ligation with caerulein stimulation or intraperitoneal injection of l-arginine in mice with deletion of interleukin (IL)12B, NLRP3, or IL18 and in mice given MCC950, a small molecule inhibitor of the NLRP3-inflammasome. Pancreata were collected from mice and analyzed by histology, and cytokine levels were measured in serum samples. We measured activation of adaptive immune responses in mice with pancreatitis by flow cytometry analysis of T cells (CD25 and CD69) isolated from the spleen. Differentiation of T-helper (Th1) cells, Th2 cells, and T-regulatory cells was determined by nuclear staining for TBET, GATA3, and FOXP3. We performed transcriptome analysis of mouse lymph nodes and bone marrow-derived macrophages after incubation with acini. We measured levels of cytokines in serum samples from patients with mild and severe acute pancreatitis.

RESULTS

Activation of the adaptive immune response in mice was initiated by macrophage-derived, caspase 1-processed cytokines and required activation of NLRP3 (confirmed in serum samples from patients with pancreatitis). Spleen cells from mice with pancreatitis had increases in Th2 cells but not in Th1 cells. Bone marrow-derived macrophages secreted IL1B and IL18, but not IL12, after co-incubation with pancreatic acini. T-cell activation and severity of acute pancreatitis did not differ significantly between IL12B-deficient and control mice. In contrast, NLRP3- or IL18-deficient mice had reduced activation of T cells and no increase in Th2 cell-mediated responses compared with control mice. The systemic type 2 immune response was mediated by macrophage-derived cytokines of the IL1 family. Specifically, IL18 induced a Th2 cell-mediated response in the absence of IL12. MCC950 significantly reduced neutrophil infiltration, T-cell activation, and disease severity in mice.

CONCLUSIONS

In mice with severe pancreatitis, we found systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome developed in parallel. Infiltrating macrophages promote inflammation and simultaneously induce a Th2 cell-mediated response via IL18. Inhibition of NLRP3 reduces systemic inflammatory response syndrome and compensatory anti-inflammatory response syndrome and might be used to treat patients with severe pancreatitis.

Antibacterial and Antifungal Therapy for Patients with Acute Pancreatitis at High Risk of Pancreatogenic Sepsis (Review)

Controlling infection is crucial in treating patients with acute pancreatitis (AP). The infectious process in AP often predisposes to subsequent sepsis by damaging not only the pancreas, but retroperitoneal tissues as well. Among other AP-associated factors, are the rapidly developing immune imbalance, the poor penetration of antimicrobial agents into necrotic tissue, and the impossibility of a single surgical debridement. Antibacterial and antifungal therapy for patients with infected necrosis and AP-associated extra-pancreatic infections remains a complex and largely unresolved problem, partially due to the high occurrence of multiresistant pathogens. The preventive use of antimicrobial agents has been discussed in the literature; however, the lack of consistent results makes it difficult to develop a unified strategy and clinical guidelines on this specific issue. Recent meta-analyses provide no conclusive evidence that antibacterial prophylaxis reduces the infection rate, mortality, or the need for surgical treatment in patients with necrotizing pancreatitis. We found only two studies indicating the benefits of using carbapenems for prophylactic purposes and one meta-analysis indicating a reduction in mortality under antibiotic treatment started no later than 72 h after the onset of the attack. Selective bowel decontamination is considered as one of the preventive anti-infection measures, although the available data may not be fully reliable. The main indications for antibacterial therapy in patients with AP are confirmed infected necrosis or extra-pancreatic infection, as well as clinical symptoms of suspected infection. Intra-arterial administration or local treatment with antibiotics can increase the efficacy of antibacterial therapy. No randomized studies on antifungal prophylaxis in AP are available; some reports though recommend using such therapy among patients at high risk of invasive candidiasis.

MicroRNAs in acute pancreatitis: From pathogenesis to novel diagnosis and therapy

Acute pancreatitis (AP) is an inflammatory disorder initiated by activation of pancreatic zymogens, leading to pancreatic injury and systemic inflammatory response. MicroRNAs (miRNAs) have emerged as important regulators of gene expression and key players in human physiological and pathological processes. Discoveries over the past decade have confirmed that altered expression of miRNAs is implicated in the pathogenesis of AP. Indeed, a number of miRNAs have been found to be dysregulated in various cell types involved in AP such as acinar cells, macrophages, and lymphocytes. These aberrant miRNAs can regulate acinar cell necrosis and apoptosis, local and systemic inflammatory response, thereby contributing to the initiation and progression of AP. Moreover, patients with AP possess unique miRNA signatures when compared with healthy individuals or those with other diseases. In view of their stability and easy detection, therefore, miRNAs have the potential to act as biomarkers for the diagnosis and assessment of patients with AP. In this review, we provide an overview of the novel cellular and molecular mechanisms underlying the roles of miRNAs during the disease processes of AP, as well as the potential diagnosis and therapeutic biomarkers of miRNAs in patients with AP.

Effects of PRSS1-PRSS2 rs10273639, CLDN2 rs7057398 and MORC4 rs12688220 polymorphisms on individual susceptibility to pancreatitis: A meta-analysis

BACKGROUND

Genetic association studies regarding relationship between PRSS1-PRSS2 rs10273639/CLDN2 rs7057398/MORC4 rs12688220 polymorphisms and pancreatitis yielded conflicting results. We performed this meta-analysis to explore associations between these polymorphisms and pancreatitis in a larger pooled population.

METHODS

A systematic search of the literature was conducted for eligible studies. We used Review Manager to conduct statistical analyses.

RESULTS

Fifteen studies were included in this meta-analysis. The results of pooled analyses showed that CLDN2 rs7057398, MORC4 rs12688220 and PRSS1-PRSS2 rs10273639 polymorphisms were all significantly associated with susceptibility to acute pancreatitis in Caucasians. Moreover, MORC4 rs12688220 and PRSS1-PRSS2 rs10273639 polymorphisms were also significantly associated with susceptibility to chronic pancreatitis in Asians.

CONCLUSIONS

Our findings suggested that rs7057398, rs12688220 and rs10273639 polymorphisms could be used to identify individuals at an elevated susceptibility to acute pancreatitis in Caucasians. Moreover, rs12688220 and rs10273639 polymorphisms could be used to identify individuals at an elevated susceptibility chronic pancreatitis in Asians.

Impact of characteristics of organ failure and infected necrosis on mortality in necrotising pancreatitis

OBJECTIVE

In patients with pancreatitis, early persisting organ failure is believed to be the most important cause of mortality. This study investigates the relation between the timing (onset and duration) of organ failure and mortality and its association with infected pancreatic necrosis in patients with necrotising pancreatitis.

DESIGN

We performed a post hoc analysis of a prospective database of 639 patients with necrotising pancreatitis from 21 hospitals. We evaluated the onset, duration and type of organ failure (ie, respiratory, cardiovascular and renal failure) and its association with mortality and infected pancreatic necrosis.

RESULTS

In total, 240 of 639 (38%) patients with necrotising pancreatitis developed organ failure. Persistent organ failure (ie, any type or combination) started in the first week in 51% of patients with 42% mortality, in 13% during the second week with 46% mortality and in 36% after the second week with 29% mortality. Mortality in patients with persistent multiple organ failure lasting <1 week, 1-2 weeks, 2-3 weeks or longer than 3 weeks was 43%, 38%, 46% and 52%, respectively (p=0.68). Mortality was higher in patients with organ failure alone than in patients with organ failure and infected pancreatic necrosis (44% vs 29%, p=0.04). However, when excluding patients with very early mortality (within 10 days of admission), patients with organ failure with or without infected pancreatic necrosis had similar mortality rates (28% vs 34%, p=0.33).

CONCLUSION

In patients with necrotising pancreatitis, early persistent organ failure is not associated with increased mortality when compared with persistent organ failure which develops further on during the disease course. Furthermore, no association was found between the duration of organ failure and mortality.

Azithromycin does not improve disease severity in acute experimental pancreatitis

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

Loss of TLR3 and its downstream signaling accelerates acinar cell damage in the acute phase of pancreatitis

BACKGROUND

Acute pancreatitis is accompanied by acinar cell damage releasing potential toll-like receptor 3 (TLR3) ligands. So far, TLR3 is known as a pattern recognition receptor in the immune signaling cascade triggering a type I interferon response. In addition, TLR3 signaling contributes to programmed cell death through the activation of caspase 8. However, the functional role of TLR3 and its downstream toll-like receptor adaptor molecule 1 (TICAM1) in the inflamed pancreas is unknown.

METHODS

To uncover the role of TLR3 signaling in acute pancreatitis, we induced a cerulein-mediated pancreatitis in Tlr3 and Ticam1 knockout (KO) mice and in wildtype animals. The exocrine damage was determined by blood serum analysis and histological examination. Immunohistochemistry, gene expression and immunoblot analysis were conducted to study TLR3 function.

RESULTS

After the induction of an acute pancreatitis, wildtype mice showed a high endosomal TLR3 expression in acinar cells. In comparison to wildtype and Ticam1 KO mice, Tlr3 KO mice exhibited the highest severity of pancreatitis with an increased NF-κB activation and elevated expression of the pro-inflammatory cytokines Il6 and Tnf, although the amount of infiltrating immune cells was unaffected. Additionally, we detected a strong elevation of acinar cell necrosis and reduced levels of cleaved caspase 8 in Tlr3 and Ticam1 KO mice.

CONCLUSIONS

TLR3 and its downstream adaptor TICAM1 are important mediators of acinar cell damage in acute pancreatitis. They possess a critical role in programmed cell death and our data suggest that TLR3 signaling controls the onset and severity of acute pancreatitis.

Abdominal paracentesis drainage ameliorates severe acute pancreatitis in rats by regulating the polarization of peritoneal macrophages

AIM

To investigate the role of peritoneal macrophage (PM) polarization in the therapeutic effect of abdominal paracentesis drainage (APD) on severe acute pancreatitis (SAP).

METHODS

SAP was induced by 5% Na-taurocholate retrograde injection in Sprague-Dawley rats. APD was performed by inserting a drainage tube with a vacuum ball into the lower right abdomen of the rats immediately after the induction of SAP. To verify the effect of APD on macrophages, PMs were isolated and cultured in an environment, with the peritoneal inflammatory environment simulated by the addition of peritoneal lavage in complete RPMI 1640 medium. Hematoxylin and eosin staining was performed. The levels of pancreatitis biomarkers amylase and lipase as well as the levels of inflammatory mediators in the blood and peritoneal lavage were determined. The polarization phenotypes of the PMs were identified by detecting the marker expression of M1/M2 macrophages via flow cytometry, qPCR and immunohistochemical staining. The protein expression in macrophages that had infiltrated the pancreas was determined by Western blot.

RESULTS

APD treatment significantly reduced the histopathological scores and levels of amylase, lipase, tumor necrosis factor-α and interleukin (IL)-1β, indicating that APD ameliorates the severity of SAP. Importantly, we found that APD treatment polarized PMs towards the M2 phenotype, as evidenced by the reduced number of M1 macrophages and the reduced levels of pro-inflammatory mediators, such as IL-1β and L-selectin, as well as the increased number of M2 macrophages and increased levels of anti-inflammatory mediators, such as IL-4 and IL-10. Furthermore, in an in vitro study wherein peritoneal lavage from the APD group was added to the cultured PMs to simulate the peritoneal inflammatory environment, PMs also exhibited a dominant M2 phenotype, resulting in a significantly lower level of inflammation. Finally, APD treatment increased the proportion of M2 macrophages and upregulated the expression of the anti-inflammatory protein Arg-1 in the pancreas of SAP model rats.

CONCLUSION

These findings suggest that APD treatment exerts anti-inflammatory effects by regulating the M2 polarization of PMs, providing novel insights into the mechanism underlying its therapeutic effect.

Deficiency of cathepsin C ameliorates severity of acute pancreatitis by reduction of neutrophil elastase activation and cleavage of E-cadherin

Acute pancreatitis is characterized by premature intracellular protease activation and infiltration of inflammatory cells, mainly neutrophil granulocytes and macrophages, into the organ. The lysosomal proteases cathepsin B, D, and L have been identified as regulators of early zymogen activation and thus modulators of the severity of pancreatitis. Cathepsin C (CTSC, syn. dipeptidly-peptidase I) is a widely expressed, exo-cystein-protease involved in the proteolytic processing of various other lysosomal enzymes. We have studied its role in pancreatitis. We used CTSC-deleted mice and their WT littermates in two experimental models of pancreatitis. The mild model involved eight hourly caerulein injections and the severe model partial duct ligation. Isolated pancreatic acini and spleen-derived leukocytes were used for ex vivo experiments. CTSC is expressed in the pancreas and in inflammatory cells. CTSC deletion reduced the severity of pancreatitis (more prominently in the milder model) without directly affecting intra-acinar cell trypsin activation in vitro The absence of CTSC reduced infiltration of neutrophil granulocytes impaired their capacity for cleaving E-cadherin in adherens junctions between acinar cells and reduced the activity of neutrophil serine proteases polymorphonuclear (neutrophil) elastase, cathepsin G, and proteinase 3, but not neutrophil motility. Macrophage invasion was not dependent on the presence of CTSC. CTSC is a regulator and activator of various lysosomal enzymes such as cathepsin B, D, and L. Its loss mitigates the severity of pancreatitis not by reducing intra-acinar cell zymogen activation but by reducing infiltration of neutrophil granulocytes into the pancreas. In this context one of its key roles is that of an activator of neutrophil elastase.

Does the Automatic Measurement of Interleukin 6 Allow for Prediction of Complications during the First 48 h of Acute Pancreatitis?

Acute pancreatitis (AP) in most patients takes a course of self-limiting local inflammation. However, up to 20% of patients develop severe AP (SAP), associated with systemic inflammation and/or pancreatic necrosis. Early prediction of SAP allows for the appropriate intensive treatment of severe cases, which reduces mortality. Serum interleukin-6 (IL-6) has been proposed as a biomarker to assist early diagnosis of SAP, however, most data come from studies utilizing IL-6 measurements with ELISA. Our aim was to verify the diagnostic usefulness of IL-6 for the prediction of SAP, organ failure, and need for intensive care in the course of AP using a fully automated assay. The study included 95 adult patients with AP of various severity (29 mild, 58 moderately-severe, 8 severe) admitted to a hospital within 24 h from the onset of symptoms. Serum IL-6 was measured using electochemiluminescence immunoassay in samples collected on admission and on the next day of hospital stay. On both days, patients with SAP presented the highest IL-6 levels. IL-6 correlated positively with other inflammatory markers (white blood cell and neutrophil counts, C-reactive protein, procalcitonin), the markers of renal injury (kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin), and the markers of endothelial dysfunction (angiopoietin-2, soluble fms-like tyrosine kinase-1). IL-6 on admission significantly predicted SAP, vital organ failure, and the need for intensive care or death, with areas under the receiver operating curve between 0.75 and 0.78, not significantly different from multi-variable prognostic scores. The fully automated assay allows for fast and repeatable measurements of serum IL-6, enabling wider clinical use of this valuable biomarker.

Circulating CD14+CD163+CD115+ M2 monocytes are associated with the severity of new onset severe acute pancreatitis in Chinese patients

BACKGROUND

Despite the role of monocytes in the pathogenesis of severe acute pancreatitis (SAP), it remains unclear how different subtypes of monocytes regulate and contribute to this pathogenesis.

METHODS

We examined the numbers of different subsets of monocytes by flow cytometry in 21 SAP, 15 mild acute pancreatitis (MAP) and 13 healthy controls (HC). The concentrations of plasma cytokines were assessed by cytometric bead array. Disease severity was evaluated based on the acute physiology and chronic health evaluation (APACHE) II score and plasma C-reactive proteins (CRP) levels.

RESULTS

Compared with the numbers in MAP patients and HC, we observed that the numbers of CD14⁺CD163^-, CD14⁺CD163^-MAC387⁺, CD14⁺CD163^-IL-12⁺ M1 monocytes, and CD115⁺, CD204⁺, IL-10⁺ M2 monocytes were significantly increased in SAP patients. In addition, these patients showed higher plasma levels of interleukin (IL)-12 and IL-10. Furthermore, the number of CD14⁺CD163^-, CD14⁺CD163^-MAC387⁺ M1 monocytes and the plasma IL-12 concentration showed a positive association with the CRP level, while the number of CD204⁺, IL-10⁺ M2 monocytes and the plasma IL-10 concentration showed a positive correlation with the APACHE II score. Importantly, the CD115⁺ M2 subset displayed a positive correlation with both the CRP level and APACHE II score, and treatment of SAP significantly reduced the number of this subset.

CONCLUSIONS

The CD14⁺CD163⁺CD115⁺ M2 monocyte count appears to be important factor in determining the severity and prognosis of SAP. Both the pro- and anti-inflammatory monocytes appear to participate in the pathogenesis of SAP.

Cathepsin B-Mediated Activation of Trypsinogen in Endocytosing Macrophages Increases Severity of Pancreatitis in Mice

BACKGROUND & AIMS

Acute pancreatitis is characterized by premature intracellular activation of digestive proteases within pancreatic acini and a consecutive systemic inflammatory response. We investigated how these processes interact during severe pancreatitis in mice.

METHODS

Pancreatitis was induced in C57Bl/6 wild-type (control), cathepsin B (CTSB)-knockout, and cathepsin L-knockout mice by partial pancreatic duct ligation with supramaximal caerulein injection, or by repetitive supramaximal caerulein injections alone. Immune cells that infiltrated the pancreas were characterized by immunofluorescence detection of Ly6g, CD206, and CD68. Macrophages were isolated from bone marrow and incubated with bovine trypsinogen or isolated acinar cells; the macrophages were then transferred into pancreatitis control or cathepsin-knockout mice. Activities of proteases and nuclear factor (NF)-κB were determined using fluorogenic substrates and trypsin activity was blocked by nafamostat. Cytokine levels were measured using a cytometric bead array. We performed immunohistochemical analyses to detect trypsinogen, CD206, and CD68 in human chronic pancreatitis (n = 13) and acute necrotizing pancreatitis (n = 15) specimens.

RESULTS

Macrophages were the predominant immune cell population that migrated into the pancreas during induction of pancreatitis in control mice. CD68-positive macrophages were found to phagocytose acinar cell components, including zymogen-containing vesicles, in pancreata from mice with pancreatitis, as well as human necrotic pancreatic tissues. Trypsinogen became activated in macrophages cultured with purified trypsinogen or co-cultured with pancreatic acini and in pancreata of mice with pancreatitis; trypsinogen activation required macrophage endocytosis and expression and activity of CTSB, and was sensitive to pH. Activation of trypsinogen in macrophages resulted in translocation of NF-kB and production of inflammatory cytokines; mice without trypsinogen activation (CTSB-knockout mice) in macrophages developed less severe pancreatitis compared with control mice. Transfer of macrophage from control mice to CTSB-knockout mice increased the severity of pancreatitis. Inhibition of trypsin activity in macrophages prevented translocation of NF-κB and production of inflammatory cytokines.

CONCLUSIONS

Studying pancreatitis in mice, we found activation of digestive proteases to occur not only in acinar cells but also in macrophages that infiltrate pancreatic tissue. Activation of the proteases in macrophage occurs during endocytosis of zymogen-containing vesicles, and depends on pH and CTSB. This process involves macrophage activation via NF-κB-translocation, and contributes to systemic inflammation and severity of pancreatitis.

Adaptive Immune Cell Dysregulation and Role in Acute Pancreatitis Disease Progression and Treatment

Acute pancreatitis (AP) is an inflammation of the pancreas caused by various stimuli including excessive alcohol consumption, gallstone disease and certain viral infections. Managing specifically the severe form of AP is limited due to lack of an understanding of the complex immune events that occur during AP involving immune cells and inflammatory molecules such as cytokines. The relative abundance of various immune cells resulting from the immune dysregulation drives disease progression. In this review, we examine the literature on the adaptive immune cells in AP, the prognostic value of these cells in stratifying patients into appropriate care and treatment strategies based on cell frequency in different AP severities are discussed.

Incidence and risk of acute coronary syndrome in patients with acute pancreatitis: A nationwide cohort study

BACKGROUND

Studies on the relationship between acute pancreatitis (AP) and acute coronary syndrome (ACS) are scant. We conducted a nationwide cohort study to investigate the incidence and risk of ACS in patients with AP.

METHODS

We enrolled patients newly diagnosed with AP between 2000 and 2010 from the Taiwan National Health Insurance Research Database and randomly selected a control cohort without a history of AP after frequency-matching for age, sex, and index year at a ratio of 4:1 for each patient with AP. The follow-up period was from the index date of new AP diagnosis to the diagnosis of ACS, censoring, or the end of 2011.

RESULTS

We assessed 87 068 patients in the AP cohort and 348 272 participants in the control cohort for 508 991 and 2 301 317 person-years, respectively. The AP cohort exhibited a higher overall incidence of ACS than the control cohort (5.44 vs 3.03 per 1000 person-y). After adjustment for sex, age, and comorbidities, the AP cohort exhibited a 1.24-fold higher adjusted hazard ratio (aHR) of ACS (95% confidence interval = 1.19-1.30) than did the control cohort. When stratified by age, the patients with AP aged ≤39 years presented a 2.37-fold higher aHR of ACS than did their corresponding controls (95% CI = 1.88-2.99). Approximate one third of ACS developed within 1 month of AP occurrence.

CONCLUSIONS

This nationwide cohort study indicated that patients with AP are at an increased risk of ACS compared with those without AP.

N,N-Dimethyl Tertiary Amino Group Mediated Dual Pancreas- and Lung-Targeting Therapy against Acute Pancreatitis

Acute pancreatitis (AP) is a sudden inflammation of the pancreas with high mortality rate worldwide. As a severe complication to AP, acute lung injury has been the major cause of death among patients with AP. Poor penetration across the blood pancreas barrier (BPB) and insufficient drug accumulation at the target site often result in poor therapeutic outcome. Our previous work successfully demonstrated a dual-specific targeting strategy to pancreas and lung using a phenolic propanediamine moiety. Inspired by this, a simplified ligand structure, N,N-dimethyl tertiary amino group, was covalently conjugated to celastrol (CLT) to afford tertiary amino conjugates via either an ester (CP) or an amide linkage (CTA). With sufficient plasma stability, CTA was subjected to the following studies. Compared to CLT, CTA exhibited excellent cellular uptake efficiency in both rat pancreatic acinar cell line (AR42J) and human pulmonary alveolar epithelial cell line (A549). Organic cation transporters were proven to be responsible for this active transport process. Given systemically, CTA specifically distributed to pancreases and lungs in rats thus resulting in a 2.59-fold and 3.31-fold increase in tissue-specific accumulation as compared to CLT. After CTA treatment, tissue lesions were greatly alleviated and the levels of proinflammatory cytokines were downregulated in rats with sodium taurocholate induced AP. Furthermore, CTA demonstrated marginal adverse effect against major organs with reduced cardiac toxicity compared to CLT. Together, tertiary amine mediated dual pancreas- and lung-targeting therapy represents an efficient and safe strategy for AP management.

Specific Etiologies Associated With the Multiple Organ Dysfunction Syndrome in Children: Part 2

OBJECTIVE

To describe a number of conditions and therapies associated with multiple organ dysfunction syndrome presented as part of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Multiple Organ Dysfunction Workshop (March 26-27, 2015). In addition, the relationship between burn injuries and multiple organ dysfunction syndrome is also included although it was not discussed at the workshop.

DATA SOURCES

Literature review, research data, and expert opinion.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Moderated by an expert from the field, issues relevant to the association of multiple organ dysfunction syndrome with a variety of conditions and therapies were presented, discussed, and debated with a focus on identifying knowledge gaps and the research priorities.

DATA SYNTHESIS

Summary of presentations and discussion supported and supplemented by relevant literature.

CONCLUSIONS

Sepsis and trauma are the two conditions most commonly associated with multiple organ dysfunction syndrome both in children and adults. However, many other pathophysiologic processes may result in multiple organ dysfunction syndrome. In this article, we discuss conditions such as liver failure and pancreatitis, pathophysiologic processes such as ischemia and hypoxia, and injuries such as trauma and burns. Additionally, therapeutic interventions such as medications, blood transfusions, transplantation may also precipitate and contribute to multiple organ dysfunction syndrome. The purpose of this article is to describe the association of multiple organ dysfunction syndrome with a variety of conditions and therapies in an attempt to identify similarities, differences, and opportunities for therapeutic intervention.

Different phenotypes of monocytes in patients with new-onset mild acute pancreatitis

AIM

To evaluate the numbers of different subsets of monocytes and their associations with the values of clinical measures in mild acute pancreatitis (MAP) patients.

METHODS

The study included one group of 13 healthy controls and another group of 24 patients with new-onset MAP. The numbers of different subsets of monocytes were examined in these two groups of subjects by flow cytometry. The concentrations of plasma interleukin (IL)-10 and IL-12 were determined by cytometric bead array. The acute physiology and chronic health evaluation (APACHE) II scores of individual patients were evaluated, and the levels of plasma C-reactive protein (CRP) as well as the activities of amylase and lipase were measured.

RESULTS

In comparison with that in the controls, significantly increased numbers of CD14+CD163-, CD14+CD163-MAC387+ M1 monocytes, but significantly reduced numbers of CD14+CD163+IL-10+ M2 monocytes were detected in the MAP patients (P < 0.01 or P < 0.05). Furthermore, significantly higher levels of plasma IL-10 and IL-12 were observed in the MAP patients (P < 0.01 for all). More importantly, the levels of plasma CRP were positively correlated with the numbers of CD14+CD163- (R = 0.5009, P = 0.0127) and CD14+CD163-MAC387+ (R = 0.5079, P = 0.0113) M1 monocytes and CD14+CD163+CD115+ M2 monocytes (R = 0.4565, P = 0.0249) in the patients. The APACHE II scores correlated with the numbers of CD14+CD163+CD115+ (R = 0.4581, P = 0.0244) monocytes and the levels of plasma IL-10 (R = 0.4178, P = 0.0422) in the MAP patients. However, there was no significant association among other measures tested in this population.

CONCLUSION

Increased numbers of CD14+CD163- and CD14+ CD163-MAC387+ monocytes may contribute to the pathogenesis of MAP, and increased numbers of CD14+CD163+CD115+ monocytes may be a biomarker for evaluating the severity of MAP.

The Interplay between Inflammation, Coagulation and Endothelial Injury in the Early Phase of Acute Pancreatitis: Clinical Implications

Acute pancreatitis (AP) is an inflammatory disease with varied severity, ranging from mild local inflammation to severe systemic involvement resulting in substantial mortality. Early pathologic events in AP, both local and systemic, are associated with vascular derangements, including endothelial activation and injury, dysregulation of vasomotor tone, increased vascular permeability, increased leukocyte migration to tissues, and activation of coagulation. The purpose of the review was to summarize current evidence regarding the interplay between inflammation, coagulation and endothelial dysfunction in the early phase of AP. Practical aspects were emphasized: (1) we summarized available data on diagnostic usefulness of the markers of endothelial dysfunction and activated coagulation in early prediction of severe AP; (2) we reviewed in detail the results of experimental studies and clinical trials targeting coagulation-inflammation interactions in severe AP. Among laboratory tests, d-dimer and angiopoietin-2 measurements seem the most useful in early prediction of severe AP. Although most clinical trials evaluating anticoagulants in treatment of severe AP did not show benefits, they also did not show significantly increased bleeding risk. Promising results of human trials were published for low molecular weight heparin treatment. Several anticoagulants that proved beneficial in animal experiments are thus worth testing in patients.

Effect of oral administration of AZD8309, a CXCR2 antagonist, on the severity of experimental pancreatitis

INTRODUCTION

Acute pancreatitis is a common gastrointestinal disorder burdened with a high mortality. Two pathophysiological events during experimental pancreatitis are thought to determine the clinical course: premature digestive protease activation and tissue infiltration by inflammatory cells. We have investigated the effect of AZD8309, a potent and orally bioavailable antagonist of the chemokine receptor CXCR2, which has been proposed to regulate the transmigration of neutrophils.

METHODS

Male C57BL6 mice (25-30 g) received gavage feeding of AZD8309 (50 mg/kg/BW) or mannitol (controls) twice daily starting 3 h prior to pancreatitis induction. Mild pancreatitis was induced by i.p. caerulein administration (50 μg/kg BW), severe pancreatitis by intraductal taurocholate (2%). Pancreas, lung, and serum was harvested up to 48 h after pancreatitis induction and used for histopathology, amylase, lipase, cathepsin B, trypsin, and elastase activity measurements, myeloperoxidase (MPO) content and cytokine concentrations.

RESULTS

Oral administration of AZD8309 significantly reduced MPO in the pancreas and lungs (8 h & 24 h) and reduced intrapancreatic trypsin and elastase activity (8 h) in caerulein-pancreatitis. In taurocholate-pancreatitis AZD8309 reduced cathepsin B activity and MPO. Serum cytokine levels were reduced by AZD8309 as well as histopathological damage.

CONCLUSION

The CXCR2 antagonist AZD8309 reduced the transmigration of neutrophils as well as intrapancreatic protease activation in experimental pancreatitis. This effect was sufficient to reduce the overall severity of the disease. CXCR2 may therefore be a viable therapeutic target and AZD8309 a suitable agent for the treatment of acute pancreatitis.

Effect of Somatostatin, Ulinastatin and Gabexate on the Treatment of Severe Acute Pancreatitis

OBJECTIVE

The objective of this study is to evaluate the efficacy of somatostatin, ulinastatin and gabexate for the treatment of severe acute pancreatitis.

MATERIALS AND METHODS

A total of 492 patients with severe acute pancreatitis were assigned randomly into the following 4 groups: (1) somatostatin; (2) somatostatin + ulinastatin; (3) somatostatin + gabexate and (4) somatostatin + ulinastatin + gabexate. Acute physiology and chronic health evaluation II scores; clinical parameters including time of abdominal pain and distention extinct; recovering to normality of heart rate and respiration rate; amylase and blood glucose; ratios of efficacy; multiple organ dysfunction syndrome (MODS); mortality; complication; levels of endotoxin; tumor necrosis factor alpha; interleukin-6 (IL-6), IL-8 and IL-10 and side effects were analyzed.

RESULTS

Acute physiology and chronic health evaluation II scores, time of abdominal pain extinct and distention extinct, time of recovering to normality of heart rate, time of recovering to normality of respiration rate and time of recovering to normality of amylase and blood glucose were significantly decreased in the somatostatin + ulinastatin, the somatostatin + gabexate and the somatostatin + ulinastatin + gabexate subgroups compared with the somatostatin subgroup. Ratios of efficacy were significantly improved, whereas ratios of MODS, mortality and complication were significantly decreased in the somatostatin + ulinastatin and the somatostatin + ulinastatin + gabexate subgroups compared with the somatostatin subgroup. Tumor necrosis factor alpha, IL-6 and IL-8 levels on the fourth day after treatment showed significant decrease in the somatostatin + ulinastatin, the somatostatin + gabexate and the somatostatin + ulinastatin + gabexate subgroups compared with the somatostatin subgroup. The IL-10 levels on the fourth day were significantly improved in the somatostatin + ulinastatin, the somatostatin + gabexate and the somatostatin + ulinastatin + gabexate subgroups compared with the somatostatin subgroup.

CONCLUSIONS

Somatostatin is effective for the treatment of acute pancreatitis, ulinastatin demonstrates improvement in therapeutic benefits and gabexate can relieve the clinical symptoms and shorten the course of disease but cannot improve the effective ratio or decrease MODS, mortality and complication.

Cathelicidin-related antimicrobial peptide modulates the severity of acute pancreatitis in mice

The present study aimed to investigate the immunomodulatory effects of mouse cathelicidin-related antimicrobial peptide (CRAMP) on experimental acute pancreatitis (AP). AP is a common clinical condition characterized by acute abdominal inflammation. Innate immune cells and mediators are intrinsically linked to the pathogenesis of AP. Cathelicidins are innate immunity-derived antimicrobial peptides that exert immunomodulatory effects on various host cells. However, how cathelicidins are involved and modulate the severity and inflammatory responses of AP remains unclear. In the present study, the mouse CRAMP gene-deficient cnlp^−/− mice and their wild-type C57BL/6J littermates were induced with AP by multiple hourly injections of supramaximal doses of caerulein. Serum amylase levels, pancreatic myeloperoxidase activity and histological examination were performed in order to determine the disease severity and the levels of inflammatory cytokines. Disease severity and inflammatory markers were subsequently evaluated in the control mice, cnlp^−/− C57BL/6J mice with AP, and wild-type C57BL/6J mice with AP. The results demonstrated that cnlp^−/− mice exhibited a more severe phenotype and inflammatory response following AP induction compared with the wild-type mice, as evidenced by increased serum amylase levels, pancreatic myeloperoxidase release, and early inflammatory mediator tumor necrosis factor-α production. Histological examination confirmed that CRAMP deficiency worsened the pancreatic inflammatory condition. These results indicate that CRAMP may be considered a novel modulatory mediator in mouse experimental AP.

Intra-abdominal pressure: Time ripe to revise management guidelines of acute pancreatitis?

AIM

To systematically review evidence on pathophysiology of intra-abdominal pressure (IAP) in acute pancreatitis (AP) with its clinical correlates.

METHODS

Systematic review of available evidence in English literature with relevant medical subject heading terms on PubMed, Medline and Scopus with further search from open access sources on internet as suggested by articles retrieved.

RESULTS

Intra-abdominal hypertension (IAH) is increasingly gaining recognition as a point of specific intervention with potential to alter disease outcome and improve mortality in AP. IAH can be expected in at least 17% of patients presenting with diagnosis of AP to a typical tertiary care hospital (prevalence increasing to 50% in those with severe disease). Abdominal compartment syndrome can be expected in at least 15% patients with severe disease. Recent guidelines on management of AP do not acknowledge utility of surveillance for IAP other than those by Japanese Society of Hepato-Biliary-Pancreatic Surgery. We further outline pathophysiologic mechanisms of IAH; understanding of which advances our knowledge and helps to coherently align common observed variations in management related conundrums (such as fluid therapy, nutrition and antibiotic prophylaxis) with potential to further individualize treatment in AP.

CONCLUSION

We suggest that IAP be given its due place in future practice guidelines and that recommendations be formed with help of a broader panel with inclusion of clinicians experienced in management of IAH.

Early prediction of intestinal mucosal barrier function impairment by elevated serum procalcitonin in rats with severe acute pancreatitis

OBJECTIVES

The aim of this study was to evaluate serum procalcitonin (PCT) levels as a prognostic indicator of intestinal barrier function impairment in rats with severe acute pancreatitis (SAP).

METHODS

Thirty-six male Sprague Dawley rats were randomly grouped into SAP group (injected sodium taurocholate via biliopancreatic duct), Gln group (gavaged with glutamine after modeling), and control group. Blood, pancreatic, and terminal ileum tissues were obtained from the rats after 6 h of modeling. Serum amylase (Amy) levels were determined using an automatic biochemical detector, while endotoxin (ET), diamine oxidase (DAO), and PCT levels were measured by ELISA test. The pathology of pancreatic and small intestine tissues were observed. PCT protein expression in intestinal tissues were detected by immunohistochemistry and western blot.

RESULT

Pancreatic and intestinal injuries in Gln group were significantly lower than SAP group. Serum amylase, DAO, and PCT levels in SAP and Gln groups differed greatly and were significantly higher than control group. Immuno-histochemistry and western blot results showed that PCT protein expression levels in small intestine tissues of SAP group were higher than Gln group and control group. Serum PCT levels had a significant correlation with serum endotoxin, DAO levels and intestinal mucosal injury scores.

CONCLUSION

PCT expression in serum and intestinal tissues in SAP rats increased significantly in the early stages of SAP, and was closely related to the onset and degree of intestinal barrier function impairment. Thus, our results showed that measuring serum PCT can be used to predict intestinal mucosal barrier function impairment in SAP rats.

Acute Pancreatitis Classifications: Basis and Key Goals

To explore the efficacy of the revised Atlanta classification (RACAP) and the determinant-based classification of acute pancreatitis severity (DBCAPS) on the basis of clinical data and feedback from patients with acute pancreatitis (AP). The authors retrospectively investigated a total of 573 patients with AP admitted to our hospital between December 2011 and December 2014. The definitions of severity and local complications in AP using RACAP and DBCAPS are presented and common points and mutual differences between the 2 groups are analyzed and discussed. Classification according to RACAP and DBCAPS found 86 (15%) and 178 (31.1%) mild cases (P < 0.01), 269 (46.9%) and 176 (30.7%) moderate cases (P < 0.01), and 218 (38.0%) and 219 (38.2%) severe cases (P = 0.95), respectively. A major contribution of DBCAPS is the introduction of a new type of severe AP, critical AP, identified in 4 patients (0.7%). Complications were observed in 313 RACAP-defined cases and 153 DBCAPS-defined cases (P < 0.01). Among the 313 RACAP-defined cases, acute peripancreatic fluid collection (236 patients, 75.40%), pancreatic pseudocysts (20 patients, 6.4%), acute necrotic collection (42 patients, 13.4%), and walled-off necrosis (15 patients, 4.8%) were observed. Among the 153 DBCAPS-defined cases, sterile peripancreatic necrosis (105 patients, 68.6%), sterile pancreatic necrosis (44 patients, 28.8%), infected peripancreatic necrosis (2 patients, 1.3%), and infected pancreatic necrosis (2/153 patients, 1.3%) were observed. Both classifications adopted organ failure and complications as determinants of severity. Revised Atlanta classification refined local complications and DBCAPS modified severity to include critical AP. In accordance with the demands of precision medicine, a combination of the 2 could be important for further clinical practice and scientific research.

Inpatient burden of childhood functional GI disorders in the USA: an analysis of national trends in the USA from 1997 to 2009

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are among the most common outpatient diagnoses in pediatric primary care and gastroenterology. There is limited data on the inpatient burden of childhood FGIDs in the USA. The aim of this study was to evaluate the inpatient admission rate, length of stay (LoS), and associated costs related to FGIDs from 1997 to 2009.

METHODS

We analyzed the Kids' Inpatient Sample Database (KID) for all subjects in which constipation (ICD-9 codes: 564.0-564.09), abdominal pain (ICD-9 codes: 789.0-789.09), irritable bowel syndrome (IBS) (ICD-9 code: 564.1), abdominal migraine (ICD-9 code: 346.80 and 346.81) dyspepsia (ICD-9 code: 536.8), or fecal incontinence (ICD-codes: 787.6-787.63) was the primary discharge diagnosis from 1997 to 2009. The KID is the largest publicly available all-payer inpatient database in the USA, containing data from 2 to 3 million pediatric hospital stays yearly.

KEY RESULTS

From 1997 to 2009, the number of discharges with a FGID primary diagnosis increased slightly from 6,348,537 to 6,393,803. The total mean cost per discharge increased significantly from $6115 to $18,058 despite the LoS remaining relatively stable. Constipation and abdominal pain were the most common FGID discharge diagnoses. Abdominal pain and abdominal migraine discharges were most frequent in the 10-14 year age group. Constipation and fecal incontinence discharges were most frequent in the 5-9 year age group. IBS discharge was most common for the 15-17 year age group.

CONCLUSIONS & INFERENCES

Hospitalizations and associated costs in childhood FGIDs have increased in number and cost in the USA from 1997 to 2009. Further studies to determine optimal methods to avoid unnecessary hospitalizations and potentially harmful diagnostic testing are indicated.

Modular analysis of bioinformatics demonstrates a critical role for NF-κB in macrophage activation

To achieve the goal of identifying the gene groups that regulated macrophage activation, a total of 925 differentially expressed genes of activated macrophages were found at the intersection of the three series (GSE5099-1, GSE5099-2, and GSE18686) from the Gene Expression Omnibus (GEO) database, and a sub-network was constructed based on the protein-protein interaction (PPI) network. Four communities (K = 3) were identified from the sub-network using the CFinder software. Community 1 was considered as the gene group of interest base on the heat map. GO-BP and KEGG enrichment analysis with the DAVID software showed that the functions of the 14 genes in community 1 were mainly related to the NF-κB pathway. A network was constructed using the Cytoscape software. The diagram showed that STAT1, NFKBIA, NFKAIB, JUN, and RELA were the key genes in the regulation of macrophage activation. Among these genes, RELA (NF-κB P65) was an important member of the NF-κB family, while NFKBIA (IκBα) and NFKAIB (IκBβ) were the inhibitory factors of NF-κB. Small molecules capable of regulating these five genes were identified via the CMap software, and a network diagram was generated using the Cytoscape software to provide a reference for the development of new drugs that regulate macrophage activation.

The ACE2-angiotensin-(1-7)-Mas axis protects against pancreatic cell damage in cell culture

OBJECTIVE

Angiotensin-converting enzyme 2 (ACE2), its product angiotensin-(1-7), and its receptor Mas have been shown to moderate the adverse effects of the ACE-angiotensin II-AT1 axis in many diseases. The aim of this study was to determine whether the ACE2-Ang-(1-7)-Mas axis could have similar effects in a cell culture model of pancreatic damage.

METHODS

AR42J cells were stimulated with 10 nmol/L cerulein to simulate acute pancreatitis. ACE2, Ang-(1-7), Mas receptor, and PI3K/AKT pathway were measured by quantitative real-time polymerase chain reaction and Western blot analysis.

RESULTS

ACE2 and Mas receptor protein levels in AR42J cells were significantly increased (P < 0.05) between 30 minutes and 6 hours postdisease induction compared with the control group. Mas receptor gene expression was significantly increased (P < 0.05) at 2 hours postdisease induction, and Ang-(1-7) was increased at 6 hours. Treatment with Ang-(1-7) in AR42J cells increased IL-10, decreased IL-6 and IL-8, and reduced the damage to pancreatic cells. Levels of IL-6 and IL-8 in AR42J cell culture were increased significantly after treatment with A779. Moreover, Ang-(1-7) increased the concentration of PI3K/AKT pathway and eNOSin AR42J cells.

CONCLUSIONS

ACE2-angiotensin-(1-7)-Mas axis significantly inhibits pancreatitis in response to decreased inflammatory factors by the activation of endothelial nitric oxide synthase and NO signaling pathways.

Redox signaling in acute pancreatitis

Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.