Blocking of monocyte chemoattractant protein-1 (MCP-1) activity attenuates the severity of acute pancreatitis in rats

Immune response mechanisms in acute and chronic pancreatitis: strategies for therapeutic intervention

Acute pancreatitis (AP) is one of the most common inflammatory diseases of the gastrointestinal tract and a steady rising diagnosis for inpatient hospitalization. About one in four patients, who experience an episode of AP, will develop chronic pancreatitis (CP) over time. While the initiating causes of pancreatitis can be complex, they consistently elicit an immune response that significantly determines the severity and course of the disease. Overall, AP is associated with a significant mortality rate of 1-5%, which is caused by either an excessive pro-inflammation, or a strong compensatory inhibition of bacterial defense mechanisms which lead to a severe necrotizing form of pancreatitis. At the time-point of hospitalization the already initiated immune response is the only promising common therapeutic target to treat or prevent a severe disease course. However, the complexity of the immune response requires fine-balanced therapeutic intervention which in addition is limited by the fact that a significant proportion of patients is in danger of development or progress to recurrent and chronic disease. Based on the recent literature we survey the disease-relevant immune mechanisms and evaluate appropriate and promising therapeutic targets for the treatment of acute and chronic pancreatitis.

Cytokine Profile Elevations on Admission Can Determine Risks of Severe Acute Pancreatitis in Children

OBJECTIVES

To utilize a Luminex platform to examine multiple cytokines simultaneously as well as clinical laboratory testing to identify markers that predict acute pancreatitis severity in the pediatric population on admission.

STUDY DESIGN

Patients (<19 years of age) prospectively enrolled over a 4-year period in a single institution acute pancreatitis database were included in separate derivation and validation cohorts. Plasma samples were obtained within 48 hours of admission and stored for analysis. Samples from mild acute pancreatitis and severe acute pancreatitis (moderately severe and severe combined) were analyzed using Luminex panels and C-reactive protein (CRP) testing.

RESULTS

The derivation cohort examined 62 cytokines in 66 subject samples (20 control, 36 mild acute pancreatitis, 10 severe acute pancreatitis) and identified interleukin 6 (IL-6) (P = .02) and monocyte chemotactic protein-1 (MCP-1) (P = .02) as cytokines that were differentially expressed between mild and severe acute pancreatitis. Our validation cohort analyzed 76 cytokines between 10 controls, 19 mild acute pancreatitis, and 6 severe acute pancreatitis subjects. IL-6 (P = .02) and MCP-1 (P = .007) were again found to differentiate mild acute pancreatitis from severe acute pancreatitis. CRP values were obtained from 53 of the subjects, revealing a strong association between elevated CRP values and progression to severe disease (P < .0001).

CONCLUSIONS

This study identified and validated IL-6 and MCP-1 as predictors of severe acute pancreatitis using 2 distinct cohorts and showed that CRP elevation is a marker of progression to severe acute pancreatitis. These biomarkers have not been extensively studied in the pediatric acute pancreatitis population. Our data allows for risk-stratification of patients with acute pancreatitis, and represent novel insight into the immunologic response in severe acute pancreatitis.

Polyphosphate, Derived from Lactobacillus brevis, Modulates the Intestinal Microbiome and Attenuates Acute Pancreatitis

BACKGROUND

We previously showed that Lactobacillus brevis-derived polyphosphate (poly P) exerts a curative effect on intestinal inflammation. However, whether or not poly P improves the inflammation and injury of distant organs remains unclear.

AIMS

We aimed to investigate the change in the intestinal microbiome and to evaluate the protective effect of poly P on injuries in a cerulein-induced acute pancreatitis (AP) mouse.

METHODS

Poly P was orally administered to BALB/C mice every day for 24 days, and then mice were intraperitoneally injected with cerulein. Before cerulein injection, stool samples were collected and analyzed by 16S rRNA gene sequencing. Mice were sacrificed at 24 h after the last cerulein injection; subsequently, the serum, pancreas, and colon were collected.

RESULTS

The microbial profile differed markedly between poly P and control group. Notably, the levels of beneficial bacteria, including Alistipes and Candidatus_Saccharimonas, were significantly increased, while those of the virulent bacteria Desulfovibrio were decreased in the poly P group. The elevations of the serum amylase and lipase levels by cerulein treatment were suppressed by the pre-administration of poly P for 24 days, but not for 7 days. The numbers of cells MPO-positive by immunohistology were decreased and the levels of MCP-1 significantly reduced in the AP + Poly P group. An immunofluorescence analysis showed that the ZO-1 and occludin in the colon was strongly augmented in the epithelial cell membrane layer in the AP + Poly P group.

CONCLUSIONS

Poly P attenuates AP through both modification of the intestinal microbiome and enhancement of the intestinal barrier integrity.

Docosahexaenoic Acid Inhibits Cytokine Expression by Reducing Reactive Oxygen Species in Pancreatic Stellate Cells

Pancreatic stellate cells (PSCs) are activated by inflammatory stimuli, such as TNF-α or viral infection. Activated PSCs play a crucial role in the development of chronic pancreatitis. Polyinosinic-polycytidylic acid (poly (I:C)) is structurally similar to double-stranded RNA and mimics viral infection. Docosahexaenoic acid (DHA) exhibits anti-inflammatory activity. It inhibited fibrotic mediators and reduced NF-κB activity in the pancreas of mice with chronic pancreatitis. The present study aimed to investigate whether DHA could suppress cytokine expression in PSCs isolated from rats. Cells were pre-treated with DHA or the antioxidant N-acetylcysteine (NAC) and stimulated with TNF-α or poly (I:C). Treatment with TNF-α or poly (I:C) increased the expression of monocyte chemoattractant protein 1 (MCP-1) and chemokine C-X3-C motif ligand 1 (CX3CL1), which are known chemoattractants, and enhanced intracellular and mitochondrial reactive oxygen species (ROS) production and NF-κB activity, but reduced mitochondrial membrane potential (MMP). Increased intracellular and mitochondrial ROS accumulation, cytokine expression, MMP disruption, and NF-κB activation were all prevented by DHA in TNF-α- or poly (I:C)-treated PSCs. NAC suppressed TNF-α- or poly (I:C)-induced expression of MCP-1 and CX3CL1. In conclusion, DHA inhibits poly (I:C)- or TNF-α-induced cytokine expression and NF-κB activation by reducing intracellular and mitochondrial ROS in PSCs. Consumption of DHA-rich foods may be beneficial in preventing chronic pancreatitis by inhibiting cytokine expression in PSCs.

The Role of Pancreatic Infiltrating Innate Immune Cells in Acute Pancreatitis

Acute pancreatitis (AP) is a leading cause of gastrointestinal-related hospital admissions with significant morbidity and mortality. Although the underlying pathophysiology of AP is rather complex, which greatly limits the treatment options, more and more studies have revealed that infiltrating immune cells play a critical role in the pathogenesis of AP and determine disease severity. Thus, immunomodulatory therapy targeting immune cells and related inflammatory mediators is expected to be a novel treatment modality for AP which may improve the prognosis of patients. Cells of the innate immune system, including macrophages, neutrophils, dendritic cells, and mast cells, represent the majority of infiltrating cells during AP. In this review, an overview of different populations of innate immune cells and their role during AP will be discussed, with a special focus on neutrophils and macrophages.

Bone marrow-derived mesenchymal stem cells alleviate severe acute pancreatitis-induced multiple-organ injury in rats via suppression of autophagy

Patients with severe acute pancreatitis (SAP) represent a substantial challenge to medical practitioners due to the high associated rates of morbidity and mortality and a lack of satisfactory therapeutic outcomes. In a previous study, our group demonstrated that bone marrow-derived mesenchymal stem cells (BMSCs) can ameliorate SAP; however, the mechanisms of action remain to be fully understood. BMSCs were intravenously injected into SAP rats 12 h after experimental induction of SAP using sodium taurocholate (NaT). Histopathological changes and the levels of pro-inflammatory mediators were assessed by hematoxylin and eosin (H&E) staining and ELISA, respectively. Autophagy levels were assessed using qRT-PCR, western blotting, immunohistochemistry, immunofluorescence, and transmission electron microscopy. AR42J cells and human umbilical vein endothelial cells (HUVECs) were administered BMSC-conditioned media (BMSC-CM) after NaT treatment, and cell viability was measured using a Cell Counting Kit-8 (CCK-8) and flow cytometry. In vivo, BMSCs effectively reduced multiple systematic inflammatory responses, suppressed the activation of autophagy, and improved intestinal dysfunction. In vitro, BMSC-CM significantly improved the viability of injured cells, promoted angiogenesis, and decreased autophagy. We therefore propose that the administration of BMSCs alleviates SAP-induced multiple organ injury by inhibiting autophagy.

Modified Da-chai-hu Decoction regulates the expression of occludin and NF-κB to alleviate organ injury in severe acute pancreatitis rats

Modified Da-chai-hu Decoction (MDD), a traditional Chinese medicinal formulation, which was empirically generated from Da-chai-hu decoction, has been utilized to treat severe acute pancreatitis (SAP) for decades. The aim of the present study was to explore its potential organprotective mechanism in SAP. In the present study, rat SAP model was induced by retrograde injection of 3.5% sodium taurocholate into the biliopancreatic duct, MDD (23.35 g/kg body weight, twelve times the clinical dose) were orally given at 2 h before and 10 h after injection. At 12 h after model induction, blood was taken from vena cava for analysis of amylase, diamine oxidase (DAO), pulmonary surfactant protein-A (SP-A), and C-reactive protein (CRP). Histopathological change of pancreas, ileum and lung was assayed by H&E staining, myeloperoxidase (MPO) activity were determinated using colorimetric assay, and the expressions of occludin and nuclear factor-κB (NF-κB) were detected by real-time RT-PCR and western blot, respectively. In addition, the tissue concentrations of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and monocyte chemoattractant protein-1 (MCP-1) were measured by enzyme-linked immunosorbent assay (ELISA). The results showed that in SAP rats, MDD significantly alleviated histopathological damage, depressed the MPO activity and the concentrations of TNF-α, IL-1β, and MCP-1 of pancreas, ileum and lung, and reduced the serum levels of amylase [(3283.4 ± 585.5) U·L^-1vs (5626.4 ± 795.1)U·L^-1], DAO [(1100.1 ± 334.3) U·L^-1vs (1666.4 ± 525.3) U·L^-1] and CRP [(7.6 ± 1.2) μg·mL^-1vs (17.8 ± 3.8) μg·mL^-1]. However, the serum SP-A concentration [(106.1 ± 16.6) pg·mL^-1vs (90.1 ± 14.9) pg·mL^-1] was elevated when treated SAP rats with MDD. Furthermore, MDD increased the occludin expression and reduced the NF-κB expression in pancreas, ileum and lung of SAP rats. Our findings suggested that MDD administration was an effective therapeutic approach for SAP treatment. It could up-regulate occludin expression to protect intercellular tight junction and down-regulate NF-κB expression to inhibit inflammatory reaction of pancreas, ileum and lung.

Interleukin-6 significantly improves predictive value of systemic inflammatory response syndrome for predicting severe acute pancreatitis

BACKGROUND

Predicting severe acute pancreatitis (AP) is important for triage, prognosis, and designing therapeutic trials. Persistent systemic inflammatory response syndrome (SIRS) predicts severe AP but its diagnostic accuracy is suboptimal. Our objective was to study if cytokine levels could improve the predictive value of clinical variables for the development of severe AP.

METHODS

Consecutive patients with AP were included in a prospective cohort study at a tertiary care center. Serum levels of IL-6, TNF-α, IL-10, MCP-1, GM-CSF and IL-1β were measured at day 3 of onset of AP. Variables such as age, co-morbidity, etiology, SIRS, and cytokines were modeled to predict severe AP by multivariable regression analysis. Genotyping was done to correlate IL-6, TNF-α and MCP-1 gene polymorphisms with cytokine levels.

RESULTS

Of 236 patients with AP, 115 patients admitted within 7 days of onset formed the study group. 37 of the 115 (32%) patients developed organ failure. Independent predictors of organ failure were persistent SIRS (OR 34; 95% CI: 7.2-159) and day 3 serum IL-6 of >160 pg/ml (OR 16.1; 95% CI:1.8-142). IL-6 gene (-174 G/C) GG genotype was associated with significantly higher levels of IL-6 compared to CC/CG genotype. Serum IL-6 >160 pg/ml increased the positive predictive value of persistent SIRS from 56% to 85% and specificity from 64% to 95% for predicting OF without compromising its sensitivity and negative predictive value.

CONCLUSION

Serum IL-6 of >160 ng/ml added significantly to the predictive value of SIRS for severe AP.

Lactose Induces Phenotypic and Functional Changes of Neutrophils and Macrophages to Alleviate Acute Pancreatitis in Mice

Acute pancreatitis (AP) is one common clinical acute abdominal disease, for which specific pharmacological or nutritional therapies remain elusive. Lactose, a macronutrient and an inducer of host innate immune responses, possesses immune modulatory functions. The current study aimed to investigate potential modulatory effects of lactose and the interplay between the nutrient and pancreatic immunity during experimentally induced AP in mice. We found that either prophylactic or therapeutic treatment of lactose time-dependently reduced the severity of AP, as evidenced by reduced pancreatic edema, serum amylase levels, and pancreatic myeloperoxidase activities, as well as by histological examination of pancreatic damage. Overall, lactose promoted a regulatory cytokine milieu in the pancreas and reduced infiltration of inflammatory neutrophils and macrophages. On acinar cells, lactose was able to suppress caerulein-induced inflammatory signaling pathways and to suppress chemoattractant tumor necrosis factor (TNF)-α and monocyte chemotactic protein-1 production. Additionally, lactose acted on pancreas-infiltrated macrophages, increasing interleukin-10 and decreasing tumor necrosis factor alpha production. Notably, lactose treatment reversed AP-associated infiltration of activated neutrophils. Last, the effect of lactose on neutrophil infiltration was mimicked by a galectin-3 antagonist, suggesting a potential endogenous target of lactose. Together, the current study demonstrates an immune regulatory effect of lactose to alleviate AP and suggests its potential as a convenient, value-added therapeutic macronutrient to control AP, and lower the risk of its systemic complications.

Mesenchymal Stromal Cell Therapy for Pancreatitis: A Systematic Review

Background

Based on animal studies, adult mesenchymal stromal cells (MSCs) are promising for the treatment of pancreatitis. However, the best type of this form of cell therapy and its mechanism of action remain unclear.

Methods

We searched the PubMed, Web of Science, Scopus, Google Scholar, and Clinical Trials.gov websites for studies using MSCs as a therapy for both acute and chronic pancreatitis published until September 2017.

Results

We identified 276 publications; of these publications, 18 met our inclusion criteria. In animal studies, stem cell therapy was applied more frequently for acute pancreatitis than for chronic pancreatitis. No clinical trials were identified. MSC therapy ameliorated pancreatic inflammation in acute pancreatitis and pancreatic fibrosis in chronic pancreatitis. Bone marrow and umbilical cord MSCs were the most frequently administered cell types. Due to the substantial heterogeneity among the studies regarding the type, source, and dose of MSCs used, conducting a meta-analysis was not feasible to determine the best type of MSCs.

Conclusion

The available data were insufficient for determining the best type of MSCs for the treatment of acute or chronic pancreatitis; therefore, clinical trials investigating the use of MSCs as therapy for pancreatitis are not warranted.

An immune-modulating formula comprising whey peptides and fermented milk improves inflammation-related remote organ injuries in diet-induced acute pancreatitis in mice

It has been demonstrated that an immune-modulating enteral formula enriched with whey peptides and fermented milk (IMF) had anti-inflammatory effects in some experimental models when it was administered before the induction of inflammation. Here, we investigated the anti-inflammatory effects of the IMF administration after the onset of systemic inflammation and investigated whether the IMF could improve the remote organ injuries in an acute pancreatitis (AP) model. Mice were fasted for 12 hours and then fed a choline-deficient and ethionine-supplemented diet (CDE diet) for 24 hours to induce pancreatitis. In experiment 1, the diet was replaced with a control enteral formula, and mice were sacrificed at 24-hour intervals for 96 hours. In experiment 2, mice were randomized into control and IMF groups and received the control formula or the IMF respectively for 72 hr or 96 hr. In experiment 1, pancreatitis was induced by the CDE diet, and inflammatory mediators were elevated for several days. Remote organ injuries such as splenomegaly, hepatomegaly, and elevation of the hepatic enzymes developed. A significant strong positive correlation was observed between plasma MCP-1 and hepatic enzymes. In experiment 2, the IMF significantly improved splenomegaly, hepatomegaly, and the elevation of hepatic enzymes. Plasma MCP-1 levels were significantly lower in the IMF group than in the control group. Nutrition management with the IMF may be useful for alleviating remote organ injuries after AP.

Genetic Polymorphisms: A Novel Perspective on Acute Pancreatitis

Acute pancreatitis (AP) is a complex disease that results in significant morbidity and mortality. For many decades, it has compelled researchers to explore the exact pathogenesis and the understanding of the pathogenesis of AP has progressed dramatically. Currently, premature trypsinogen activation and NF-κB activation for inflammation are two remarkable hypotheses for the mechanism of AP. Meanwhile, understanding of the influence of genetic polymorphisms has resulted in tremendous development in the understanding of the advancement of complex diseases. Now, genetic polymorphisms of AP have been noted gradually and many researchers devote themselves to this emerging area. In this review, we comprehensively describe genetic polymorphisms combined with the latest hypothesis of pathogenesis associated with AP.

Inulin-Type Fructans Modulates Pancreatic-Gut Innate Immune Responses and Gut Barrier Integrity during Experimental Acute Pancreatitis in a Chain Length-Dependent Manner

Acute pancreatitis (AP) is a common abdominal inflammatory disorder and one of the leading causes of hospital admission for gastrointestinal disorders. No specific pharmacological or nutritional therapy is available but highly needed. Inulin-type fructans (ITFs) are capable of modifying gut immune and barrier homeostasis in a chemistry-dependent manner and hence potentially applicable for managing AP, but their efficacy in AP has not been demonstrated yet. The current study aimed to examine and compare modulatory effects of ITFs with different degrees of fermentability on pancreatic-gut immunity and barrier function during experimentally induced AP in mice. BALB/c mice were fed short (I)- or long (IV)-chain ITFs supplemented diets for up to 3 days before AP induction by caerulein. Attenuating effects on AP development were stronger with ITF IV than with ITF I. We found that long-chain ITF IV attenuated the severity of AP, as evidenced by reduced serum amylase levels, lipase levels, pancreatic myeloperoxidase activity, pancreatic edema, and histological examination demonstrating reduced pancreatic damage. Short-chain ITF I demonstrated only partial protective effects. Both ITF IV and ITF I modulated AP-associated systemic cytokine levels. ITF IV but not ITF I restored AP-associated intestinal barrier dysfunction by upregulating colonic tight junction modulatory proteins, antimicrobial peptides, and improved general colonic histology. Additionally, differential modulatory effects of ITF IV and ITF I were observed on pancreatic and gut immunity: ITF IV supplementation prevented innate immune cell infiltration in the pancreas and colon and tissue cytokine production. Similar effects were only observed in the gut with ITF I and not in the pancreas. Lastly, ITF IV but not ITF I downregulated AP-triggered upregulation of IL-1 receptor-associated kinase 4 (IRAK-4) and phosphor-c-Jun N-terminal kinase (p-JNK), and a net decrease of phosphor-nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 (p-NF-κB p65) nuclear translocation and activation in the pancreas. Our findings demonstrate a clear chain length-dependent effect of inulin on AP. The attenuating effects are caused by modulating effects of long-chain inulin on the pancreatic-gut immunity via the pancreatic IRAK-4/p-JNK/p-NF-κBp65 signaling pathway and on prevention of disruption of the gut barrier.

Infusion of Bone Marrow Mesenchymal Stem Cells Attenuates Experimental Severe Acute Pancreatitis in Rats

Background & Aims. Severe acute pancreatitis (SAP) remains a high-mortality disease. Bone marrow (BM) mesenchymal stem cells (MSCs) have been demonstrated to have plasticity of transdifferentiation and to have immunomodulatory functions. In the present study, we assessed the roles of MSCs in SAP and the therapeutic effects of MSC on SAP after transplantation. Methods. A pancreatitis rat model was induced by the injection of taurocholic acid (TCA) into the pancreatic duct. After isolation and characterization of MSC from BM, MSC transplantation was conducted 24 hrs after SAP induction by tail vein injection. The survival rate was observed and MSCs were traced after transplantation. The expression of TNF-α and IL-1β mRNA in the transplantation group was also analyzed. Results. The survival rate of the transplantation group was significantly higher compared to the control group (p < 0.05). Infused MSCs were detected in the pancreas and BM 3 days after transplantation. The expression of TNF-α and IL-1β mRNA in the transplantation group was significantly lower than in the control group in both the pancreas and the lungs (p < 0.05). Conclusions. MSC transplantation could improve the prognosis of SAP rats. Engrafted MSCs have the capacity of homing, migration, and planting during the treatment of SAP.

Therapeutic implications of innate immune system in acute pancreatitis

INTRODUCTION

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas encompassing a cascade of cellular and molecular events. It starts from premature activation of zymogens with the involvement of innate immune system to a potential systemic inflammatory response and multiple organ failure. Leukocytes are the major cell population that participate in the propagation of the disease. Current understanding of the course of AP is still far from complete, limiting treatment options mostly to conservative supportive care. Emerging evidence has pointed to modulation of the immune system for strategic therapeutic development, by mitigating the inflammatory response and severity of AP. In the current review, we have focused on the role of innate immunity in the condition and highlighted therapeutics targeting it for treatment of this challenging disease.

AREAS COVERED

The current review has aimed to elaborate in-depth understanding of specific roles of innate immune cells, derived mediators and inflammatory pathways that are involved in AP. Summarizing the recent therapeutics and approaches applied experimentally that target immune responses to attenuate AP.

EXPERT OPINION

The current state of knowledge on AP, limitations of presently available therapeutic approaches and the promise of therapeutic implications of innate immune system in AP are discussed.

Immunomodulatory therapies for acute pancreatitis

It is currently difficult for conventional treatments of acute pancreatitis (AP), which primarily consist of anti-inflammatory therapies, to prevent the progression of AP or to improve its outcome. This may be because the occurrence and progression of AP, which involves various inflammatory cells and cytokines, includes a series of complex immune events. Considering the complex immune system alterations during the course of AP, it is necessary to monitor the indicators related to immune cells and inflammatory mediators and to develop more individualized interventions for AP patients using immunomodulatory therapy. This review discusses the recent advances in immunomodulatory therapies. It has been suggested that overactive inflammatory responses should be inhibited and excessive immunosuppression should be avoided in the early stages of AP. The optimal duration of anti-inflammatory therapy may be shorter than previously expected (< 24 h), and appropriate immunostimulatory therapies should be administered during the period from the 3^rd d to the 14^th d in the course of AP. A combination therapy of anti-inflammatory and immune-stimulating drugs would hopefully constitute an alternative to anti-inflammatory drug monotherapy. Additionally, the detection of the genotypes of critical inflammatory mediators may be useful for screening populations of AP patients at high risk of severe infections to enable the administration of early interventions to improve their prognosis.

Difference in Early Activation of NF-κB and MCP-1 in Acinar-Cell-Rich versus Fibrotic Human Pancreas Exposed to Surgical Trauma and Hypoxia

Objectives. Previously we have shown that a pancreas with over 40% acinar cells is exposed to postoperative pancreatitis and other complications after pancreaticoduodenectomy (PD). Our aim was to analyze the expression of NF-κB and MCP-1 in the cut edge of human pancreas after PD in both acinar-cell-rich and fibrotic pancreata. Methods. Several pancreatic samples from six patients, three with acinar-cell-rich and three with fibrotic pancreata, were exposed to surgical trauma in PD, and thereafter to hypoxemia for 15 minutes, 2-2.5 hours, 4 hours, or 6 hours, to mimic postoperative conditions of the pancreatic remnant in a patient. Immunohistochemical analysis of inflammation markers (NF-κB, MCP-1) was performed. Results. In the acinar-cell-rich pancreata, intra-acinar NF-κB and MCP-1 expression increased from mild at 15 minutes to high during the first 4 hours, whereas in ductal cells MCP-1 staining was highly intense at both time points. Acinar cell NF-κB and MCP-1 expression and ductal cell MCP-1 expression were also observed in the fibrotic pancreata, but the activation remained low throughout the 6 hours. Conclusions. In acinar-cell-rich pancreas, an extensive inflammatory cascade begins almost immediately after surgical trauma. Fibrosis may limit the progression of inflammatory process in pancreas.

Pancreatic fat accumulation, fibrosis, and acinar cell injury in the Zucker diabetic fatty rat fed a chronic high-fat diet

OBJECTIVE

The histological alteration of the exocrine pancreas in obesity has not been clarified. In the present study, we investigated biochemical and histological changes in the exocrine pancreas of obese model rats.

METHODS

Zucker lean rats were fed a standard diet, and Zucker diabetic fatty (ZDF) rats were divided into 2 groups fed a standard diet and a high-fat diet, respectively. These experimental groups were fed each of the diets from 6 weeks until 12, 18, 24 weeks of age. We performed blood biochemical assays and histological analysis of the pancreas.

RESULTS

In the ZDF rats fed a high-fat diet, the ratio of accumulated pancreatic fat area relative to exocrine gland area was increased significantly at 18 weeks of age in comparison with the other 2 groups (P < 0.05), and lipid droplets were observed in acinar cells. Subsequently, at 24 weeks of age in this group, pancreatic fibrosis and the serum exocrine pancreatic enzyme levels were increased significantly relative to the other 2 groups (P < 0.01).

CONCLUSIONS

In ZDF rats fed a chronic high-fat diet, fat accumulates in pancreatic acinar cells, and this fatty change seems to be related to subsequent pancreatic fibrosis and acinar cell injury.

Pancreatic stellate cells and CX3CR1: occurrence in normal pancreas and acute and chronic pancreatitis and effect of their activation by a CX3CR1 agonist

OBJECTIVES

Numerous studies suggest important roles of the chemokine, fractalkine (CX3CL1), in acute/chronic pancreatitis; however, the possible mechanisms of the effects are unclear. Pancreatic stellate cells (PSCs) can play important roles in pancreatitis, secreting inflammatory cytokines/chemokines, as well as proliferation. Therefore, we investigated CX3CL1 receptor (CX3CR1) occurrence in normal pancreas and pancreatitis (acute/chronic) tissues and the effects of CX3CL1 on activated PSCs.

METHODS

CX3CR1 expression/localization in normal pancreas and pancreatitis (acute/chronic) tissues was evaluated with immunohistochemical analysis. CX3CR1 expression and effects of CX3CL1 on activated PSCs were examined with real-time polymerase chain reaction, BrdU (5-bromo-2-deoxyuridine) assays, and Western blotting.

RESULTS

In normal pancreas, acinar cells expressed CX3CR1 within granule-like formations in the cytoplasm, whereas in acute/chronic pancreatitis, acinar, ductal, and activated PSCs expressed CX3CR1 on cell membranes. With activation of normal PSCs, CX3CR1 is increased. CX3CL1 activated multiple signaling cascades in PSCs. CX3CL1 did not induce inflammatory genes expression in activated PSCs, but induced proliferation.

CONCLUSIONS

CX3CR1s are expressed in normal pancreas. Expression is increased in acute/chronic pancreatitis, and the CX3CR1s are activated. CX3CL1 induces proliferation of activated PSCs without increasing release of inflammatory mediators. These results suggest that CX3CR1 activation of PSCs could be important in their effects in pancreatitis, especially to PSC proliferation in pancreatitis where CX3CL1 levels are elevated.

Monocytes infiltrate the pancreas via the MCP-1/CCR2 pathway and differentiate into stellate cells

Recent studies have shown that monocytes possess pluripotent plasticity. We previously reported that monocytes could differentiate into hepatic stellate cells. Although stellate cells are also present in the pancreas, their origin remains unclear. An accumulation of enhanced green fluorescent protein (EGFP)⁺CD45^– cells was observed in the pancreases and livers of chimeric mice, which were transplanted with a single hematopoietic stem cell isolated from EGFP-transgenic mice and treated with carbon tetrachloride (CCl₄). Because the vast majority of EGFP⁺CD45^– cells in the pancreas expressed stellate cell-associated antigens such as vimentin, desmin, glial fibrillary acidic protein, procollagen-I, and α-smooth muscle actin, they were characterized as pancreatic stellate cells (PaSCs). EGFP⁺ PaSCs were also observed in CCl₄-treated mice adoptively transferred with monocytes but not with other cell lineages isolated from EGFP-transgenic mice. The expression of monocyte chemoattractant protein-1 (MCP-1) and angiotensin II (Ang II) increased in the pancreas of CCl₄-treated mice and their respective receptors, C-C chemokine receptor 2 (CCR2) and Ang II type 1 receptor (AT1R), were expressed on Ly6C^high monocytes isolated from EGFP-transgenic mice. We examined the effect of an AT1R antagonist, irbesartan, which is also a CCR2 antagonist, on the migration of monocytes into the pancreas. Monocytes migrated toward MCP-1 but not Ang II in vitro. Irbesartan inhibited not only their in vitro chemotaxis but also in vivo migration of adoptively transferred monocytes from peripheral blood into the pancreas. Irbesartan treatment significantly reduced the numbers of EGFP⁺F4/80⁺CCR2⁺ monocytic cells and EGFP⁺ PaSCs in the pancreas of CCl₄-treated chimeric mice receiving EGFP⁺ bone marrow cells. A specific CCR2 antagonist RS504393 inhibited the occurrence of EGFP⁺ PaSCs in injured mice. We propose that CCR2⁺ monocytes migrate into the pancreas possibly via the MCP-1/CCR2 pathway and give rise to PaSCs.

Treatment of pancreatic fibrosis with siRNA against a collagen-specific chaperone in vitamin A-coupled liposomes

BACKGROUND AND OBJECTIVE

Fibrosis associated with chronic pancreatitis is an irreversible lesion that can disrupt pancreatic exocrine and endocrine function. Currently, there are no approved treatments for this disease. We previously showed that siRNA against collagen-specific chaperone protein gp46, encapsulated in vitamin A-coupled liposomes (VA-lip-siRNAgp46), resolved fibrosis in a model of liver cirrhosis. This treatment was investigated for pancreatic fibrosis induced by dibutyltin dichloride (DBTC) and cerulein in rats.

METHODS

Specific uptake of VA-lip-siRNAgp46, conjugated with 6'-carboxyfluorescein (FAM) by activated pancreatic stellate cells (aPSCs), was analysed by fluorescence activated cell sorting (FACS). Intracellular distribution of VA-lip-siRNAgp46-FAM was examined by fluorescent microscopy. Suppression of gp46 expression by VA-lip-siRNAgp46 was assessed by immunoblotting. Collagen synthesis in aPSCs was assayed by dye-binding. Specific delivery of VA-lip-siRNAgp46 to aPSCs in DBTC rats was verified following intravenous VA-lip-siRNA-FAM and (3)H-VA-lip-siRNAgp46. The effect of VA-lip-siRNA on pancreatic histology in DBTC- and cerulein-treated rats was determined by Azan-Mallory staining and hydroxyproline content.

RESULTS

FACS analysis revealed specific uptake of VA-lip-siRNAgp46-FAM through the retinol binding protein receptor by aPSCs in vitro. Immunoblotting and collagen assay verified knockdown of gp46 and suppression of collagen secretion, respectively, by aPSCs after transduction of VA-lip-siRNAgp46. Specific delivery of VA-lip-siRNAgp46 to aPSCs in fibrotic areas in DBTC rats was confirmed by fluorescence and radioactivity 24 h after the final injection. 10 systemic VA-lip-siRNAgp46 treatments resolved pancreatic fibrosis, and suppressed tissue hydroxyproline levels in DBTC- and cerulein-treated rats.

CONCLUSION

These data suggest the therapeutic potential of the present approach for reversing pancreatic fibrosis.

Scolopendra subspinipes mutilans protected the cerulein-induced acute pancreatitis by inhibiting high-mobility group box protein-1

AIM: To evaluate the inhibitory effects of Scolopendra subspinipes mutilans (SSM) on cerulein-induced acute pancreatitis (AP) in a mouse model.

METHODS: SSM water extract (0.1, 0.5, or 1 g/kg) was administrated intraperitoneally 1 h prior to the first injection of cerulein. Once AP developed, the stable cholecystokinin analogue, cerulein was injected hourly, over a 6 h period. Blood samples were taken 6 h later to determine serum amylase, lipase, and cytokine levels. The pancreas and lungs were rapidly removed for morphological examination, myeloperoxidase assay, and real-time reverse transcription polymerase chain reaction. To specify the role of SSM in pancreatitis, the pancreatic acinar cells were isolated using collagenase method. Then the cells were pre-treated with SSM, then stimulated with cerulein. The cell viability, cytokine productions and high-mobility group box protein-1 (HMGB-1) were measured. Furthermore, the regulating mechanisms of SSM action were evaluated.

RESULTS: The administration of SSM significantly attenuated the severity of pancreatitis and pancreatitis associated lung injury, as was shown by the reduction in pancreatic edema, neutrophil infiltration, vacuolization and necrosis. SSM treatment also reduced pancreatic weight/body weight ratio, serum amylase, lipase and cytokine levels, and mRNA expression of multiple inflammatory mediators such as tumor necrosis factor-α and interleukin-1β. In addition, treatment with SSM inhibited HMGB-1 expression in the pancreas during AP. In accordance with in vivo data, SSM inhibited the cerulein-induced acinar cell death, cytokine, and HMGB-1 release. SSM also inhibited the activation of c-Jun NH2-terminal kinase, p38 and nuclear factor (NF)-κB.

CONCLUSION: These results suggest that SSM plays a protective role during the development of AP and pancreatitis associated lung injury via deactivating c-Jun NH2-terminal kinase, p38 and NF-κB.

Progress in treatment of pancreatitis with bone marrow mesenchymal stem cells

Severe acute pancreatitis, characterized by a rapid onset and the heaviness of the disease, has a mortality rate of 20%-40%. The major causes of acute pancreatitis are symptomatic gallstone disease and excessive alcohol intake. Drugs, toxins, infections, trauma, ischemia, anatomic variants, hypercalcemia, hyperlipidemia and autoimmune disease are rare causes. Although revolutionary progress has been made in the diagnosis and treatment of severe acute pancreatitis, its mortality rate is still high. Currently, too much attention is paid to restraining pancreatic enzyme secretion and preventing multiple organ secondary damage in the treatment of severe acute pancreatitis, and promotion of functional recovery of the pancreas is less considered. Bone marrow mesenchymal stem cells can be used to promote the functional recovery of the pancreas in patients with severe acute pancreatitis.

Chemokine receptor CXCR3 is involved in the acute pancreatitis-associated lung injury

Acute pancreatitis is a common disease, which is divided into mild pancreatitis and severe pancreatitis. For the latter, a systemic inflammatory response may occur and lead to distant organ damage and the development of multiple organ dysfunction syndrome (MODS), which accounts for significant morbidity and mortality in humans. Chemokines and their receptors are being believed to play a pivotal role in the pathogenesis of acute pancreatitis. Chemokine receptor CXCR3 is reported to be involved in acute tissue injury, for example acute lung injury induced by cigarette smoking, but its role in acute pancreatitis is not yet known. In this study, two animal models of acute pancreatitis (cerulein- and arginine-induced pancreatitis) were applied in CXCR3⁻/⁻ mice and wild-type mice, in order to explore the role of CXCR3 in acute pancreatitis. Serum amylase, lipase and histological observations revealed that CXCR3 knockout did not affect the severity of acute pancreatitis. However, edema and inflammatory cell infiltrate in the lung tissue were attenuated in CXCR3⁻/⁻ mice when acute pancreatitis was induced. In conclusion, chemokine receptor CXCR3 is not involved in acute pancreatic injury, but has a connection with acute pancreatitis-associated lung injury. Acute pulmonary injury is attenuated in CXCR3 knockout mice in experimental acute pancreatitis.

Potential therapeutic effect of bone marrow-derived mesenchymal stem cells in acute pancreatitis

Acute pancreatitis is an inflammatory disease with dropsical, hemorrhagic or even necrotic conditions of the pancreas caused by several factors. It has significant morbidity and mortality, but no specific therapy is available so far. Bone marrow-derived mesenchymal stem cells (BMSCs) have multiple differentiation potential. They can not only differentiate to form endoderm and ectoblast cells, but also participate in tissue regeneration, repair and anti-inflammation. Recent studies have demonstrated that BMSCs have potential therapeutical effect in acute pancreatitis. BMSCs can migrate to injury tissue, multiply, be transformed to pancreatic stem cells and then participate in the process of regeneration. They also renovate vascular endothelium to improve blood circulation, adjust and control the cytokines to decrease inflammation, and regulate immunization. Here we review the recent advances in understanding the role of BMSCs in the treatment of acute pancreatitis.

Vasoactive intestinal peptide reduces oxidative stress in pancreatic acinar cells through the inhibition of NADPH oxidase

Vasoactive intestinal peptide (VIP) attenuates experimental acute pancreatitis (AP) by inhibition of cytokine production from inflammatory cells. It has been suggested that reactive oxygen species (ROS) as well as cytokines play pivotal roles in the early pathophysiology of AP. This study aimed to clarify the effect of VIP on the oxidative condition in pancreas, especially pancreatic acinar cells (acini). Hydrogen peroxide (H(2)O(2))-induced intracellular ROS, assessed with CM-H(2)DCFDA, increased time- and dose-dependently in acini isolated from rats. Cell viability due to ROS-induced cellular damage, evaluated by MTS assay, was decreased with ≥100 μmol/L H(2)O(2). VIP significantly inhibited ROS production from acini and increased cell viability in a dose-dependent manner. Expression of antioxidants including catalase, glutathione reductase, superoxide dismutase (SOD) 1 and glutathione peroxidase was not altered by VIP except for SOD2. Furthermore, Nox1 and Nox2, major components of NADPH oxidase, were expressed in pancreatic acini, and significantly increased after H(2)O(2) treatment. Also, NADPH oxidase activity was provoked by H(2)O(2). VIP decreased NADPH oxidase activity, which was abolished by PKA inhibitor H89. These results suggested that VIP affected the mechanism of ROS production including NADPH oxidase through induction of a cAMP/PKA pathway. In conclusion, VIP reduces oxidative stress in acini through the inhibition of NADPH oxidase. These results combined with findings of our previous study suggest that VIP exerts its protective effect in pancreatic damage, not only through an inhibition of cytokine production, but also through a reduction of the injury caused by oxidative stress.

Upregulation of pancreatic derived factor (FAM3B) expression in pancreatic β-cells by MCP-1 (CCL2)

Pancreatic derived factor (PANDER, FAM3B) is a peptide mainly synthesized and secreted by pancreatic β-cells. PANDER is proposed to be involved in regulation of β-cell function under physiological conditions and impairment of β-cell function under pathological conditions. MCP-1 (CCL2) is expressed by normal pancreatic islets and has been implicated in inflammation related pancreatic disorders. We examined the effect of MCP-1 on PANDER expression by using murine pancreatic β-cell line MIN6 and pancreatic islets. We found that MCP-1 induced PANDER mRNA transcription and protein synthesis in MIN6 cells and islets. By using calcium chelator (EGTA); inhibitors for PKC (Go6976), MEK1/2 (PD98059) or c-Jun-N-terminal kinase (JNK) (SP600125); c-Jun dominant-negative construct; PANDER promoter luciferase constructs; and islets isolated from Fos knockout mice; we demonstrated that MCP-1 induced PANDER gene expression in β-cells through Ca(2+)-ERK1/2-AP-1 and PKC-JNK-AP-1 signaling pathways. Our findings suggest a new link between the endocrine and immune systems and provide useful information for further investigating the physiological functions of PANDER and its involvement in inflammation-related pancreatic disorders.

Pomalidomide suppresses cerulein-induced acute pancreatitis in mice

BACKGROUND

An overproduction of proinflammatory mediators in severe acute pancreatitis contributes to the systemic inflammatory response, which may lead to multiorgan damage and even death. Thus, inflammatory cytokines, e.g., tumor necrosis factor (TNF)-α and interleukin (IL)-1β, may be novel targets for the treatment of acute pancreatitis. The aim of this study was to investigate the therapeutic effects of pomalidomide (or CC-4047), a thalidomide analog and immunomodulatory agent, in acute pancreatitis.

METHODS

Acute pancreatitis was induced in C57BL/6 mice by intraperitoneal administration of cerulein (100 μg/kg/h × 8). Pomalidomide was administered (0.5 mg/kg orally) 1 h before the first or 1 h after the last cerulein administration. The severity of the acute pancreatitis was evaluated biochemically and morphologically.

RESULTS

Pretreatment with pomalidomide significantly reduced the plasma levels of amylase and lipase; the histological injury; and the expression of TNF-α, IL-1β, monocyte chemotactic protein-1 (MCP-1), and inducible nitric oxide synthase (iNOS) in cerulein-induced acute pancreatitis. Post-treatment with pomalidomide also decreased the cerulein-induced elevation of plasma amylase and lipase and decreased the pancreatic damage.

CONCLUSIONS

Treatment with pomalidomide ameliorated the severity of cerulein-induced acute pancreatitis in mice. Our data suggest that pomalidomide may become a new therapeutic agent in future clinical trials for the treatment of acute pancreatitis.

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.

L-Arginine-induced acute pancreatitis results in mild lung inflammation without altered respiratory mechanics

Acute lung injury is a common complication of acute pancreatitis (AP) and contributes to the majority of AP-associated deaths. Although some aspects of AP-induced lung inflammation have been demonstrated, investigation of resultant changes in lung function is limited. The aim of this study was to characterize acute lung injury in L-arginine-induced AP. Seven groups of male Sprague-Dawley rats (n = 4-10/group) received 2 intraperitoneal (i.p.) injections of L-arginine (250 mg/100 g) at 6, 12, 24, 36, 48, or 72 hours before measurement of lung impedance mechanics. Control rats (n = 10) received i.p. saline. Bronchoalveolar lavage (BAL), plasma, and pancreatic and lung tissue were collected to determine pancreatic and lung measures of acute inflammation. AP developed between 6 and 36 hours, as indicated by increased pancreatic abnormal acinar cells, myeloperoxidase (MPO) activity, edema, and plasma amylase activity, before beginning to resolve by 72 hours. In the lung, MPO activity increased (2.4-fold) from 12 hours, followed by a modest increase in lung edema at 48 hours, with increased BAL cell count (2.5-fold) up to 72 hours (P < .05). In contrast, no significant changes in lung mechanics were evident over the same period. Despite measurable lung inflammation, no significant deterioration in respiratory function resulted from L-arginine-induced AP.

Caerulein-induced acute pancreatitis results in mild lung inflammation and altered respiratory mechanics

Acute lung injury is a common complication of acute pancreatitis (AP) and contributes to the majority of AP-associated deaths. Although some aspects of AP-induced lung inflammation have been demonstrated, investigation of resultant changes in lung function is limited. The aim of this study was to characterize lung injury in caerulein-induced AP. Male Sprague Dawley rats (n = 7-8/group) received 7 injections of caerulein (50 μg/kg) at 12, 24, 48, 72, 96, or 120 hours before measurement of lung impedance mechanics. Bronchoalveolar lavage (BAL), plasma, pancreatic, and lung tissue were collected to determine pancreatic and lung measures of acute inflammation. AP developed between 12 and 24 hours, as indicated by increased plasma amylase activity and pancreatic myeloperoxidase (MPO) activity, edema, and abnormal acinar cells, before beginning to resolve by 48 hours. In the lung, MPO activity peaked at 12 and 96 hours, with BAL cytokine concentrations peaking at 12 hours, followed by lung edema at 24 hours, and BAL cell count at 48 hours. Importantly, no significant changes in BAL protein concentration or arterial blood gas-pH levels were evident over the same period, and only modest changes were observed in respiratory mechanics. Caerulein-induced AP results in minor lung injury, which is not sufficient to allow protein permeability and substantially alter respiratory mechanics.

Inflammatory role of the acinar cells during acute pancreatitis

Pancreatic acinar cells are secretory cells whose main function is to synthesize, store and finally release digestive enzymes into the duodenum. However, in response to noxious stimuli, acinar cells behave like real inflammatory cells because of their ability to activate signalling transduction pathways involved in the expression of inflammatory mediators. Mediated by the kinase cascade, activation of Nuclear factor-κB, Activating factor-1 and Signal transducers and activators of transcription transcription factors has been demonstrated in acinar cells, resulting in overexpression of inflammatory genes. In turn, kinase activity is down-regulated by protein phosphatases and the final balance between kinase and phosphatase activity will determine the capability of the acinar cells to produce inflammatory factors. The kinase/phosphatase pair is a redox-sensitive system in which kinase activation overwhelms phosphatase activity under oxidant conditions. Thus, the oxidative stress developed within acinar cells at early stages of acute pancreatitis triggers the activation of signalling pathways involved in the up-regulation of cytokines, chemokines and adhesion molecules. In this way, acinar cells trigger the release of the first inflammatory signals which can mediate the activation and recruitment of circulating inflammatory cells into the injured pancreas. Accordingly, the role of acinar cells as promoters of the inflammatory response in acute pancreatitis may be considered. This concept leads to amplifying the focus from leukocyte to acinar cells themselves, to explain the local inflammation in early pancreatitis.

Connections between genetics and clinical data: Role of MCP-1, CFTR, and SPINK-1 in the setting of acute, acute recurrent, and chronic pancreatitis

OBJECTIVES

Acute, acute recurrent, and chronic pancreatitis are inflammatory diseases with multifactorial pathogenic mechanisms. Genetic mutations and polymorphisms have been correlated with pancreatitis. The aim of this study was to investigate the association of cystic fibrosis transmembrane conductance regulator (CFTR) and serine protease inhibitor Kazal type 1 (SPINK-1) gene mutations and monocyte chemoattractant protein 1 (MCP-1) -2518A/G polymorphism with acute pancreatitis (AP), acute recurrent pancreatitis (ARP), and chronic pancreatitis (CP), and to associate genetic backgrounds with clinical phenotype in these three conditions.

METHODS

One hundred eighteen AP, 64 ARP, 142 CP patients, and 88 normal controls were enrolled consecutively. We analyzed MCP-1 serum levels using enzyme-linked immunosorbent assay. Polymorphism -2518 of MCP-1 and SPINK-1 N34S gene mutations were determined by PCR-restriction-fragment length polymorphism. Sequence analysis was performed when necessary. Thirty-three CFTR mutations were analyzed in CP and ARP patients using multiplex DNA testing.

RESULTS

Serum MCP-1 levels were significantly higher in all patients affected by pancreatic inflammatory diseases. Moreover, we found a significant over-representation of the MCP-1G allele in ARP patients. We found a statistically significant association of CFTR gene mutations with ARP, but not with CP. We did not find a statistically significant association of ARP or CP with the N34S SPINK-1 gene mutation. Interestingly, 39 of 64 ARP patients (61%) carried at least one genetic mutation and/or polymorphism. Five of 64 ARP patients had pancreas divisum and four of these five also carried the G allele.

CONCLUSIONS

Analysis of a comprehensive range of potential susceptibility variants is needed to support modeling of the effects of genes and environment in pancreatitis. As such, beyond gene mutations, the context within which those mutations exist must be considered. In pancreatitis the context includes the inflammatory response, clinical features, and exogenous factors.

Genetic polymorphism of MCP-1-2518, IL-8-251 and susceptibility to acute pancreatitis: a pilot study in population of Suzhou, China

AIM

To study the relationship between MCP-1-2518A/G, IL-8-251A/T polymorphism and acute pancreatitis (AP) in the Han population of Suzhou, China.

METHODS

A case-control study was conducted to compare the distribution of genotype and genetic frequency of MCP-1-2518A/G, IL-8-251A/T gene polymorphism among AP (n = 101), including mild AP (n = 78) and severe AP (n = 23) and control healthy individuals (n = 120) with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing, and analyze the relationship between the MCP-1-2518A/G, IL-8-251A/T gene polymorphism and the susceptibility to AP.

RESULTS

Significant differences were found in the distribution of genotype of MCP-1-2518A/G between the healthy control group and mild AP group (chi2 = 32.015, P < 0.001), the same was evident between the healthy control group and severe AP group (chi2 = 12.932, P < 0.05) in Suzhou. However, no difference of genotypic distribution was noted between MAP and SAP (chi2 = 0.006, P = 0.997). The genetic frequencies of G allele in mild AP were 72.4% (113/156) and 76.1% (35/46) in severe AP, both were higher than the controls, 47.1% (113/240) (chi2 = 24.804; P < 0.001, and chi2 = 13.005; P < 0.001), but no difference was found between severe AP and mild AP (chi2 = 0.242; P = 0.623). No difference was found in the distribution of genotype of IL-8-251A/T between the healthy control group and AP group neither in the frequency of A and T allele.

CONCLUSION

The MCP-1-2518 AA genotype of the population in Suzhou may be a protective genotype of AP, while one with higher frequency of G allele is more likely to suffer from pancreatitis. But the genotype of AA and the frequency of G allele could not predict the risk of severe AP. No correlation is found between the IL-8-251 polymorphism and the liability of AP.