Adiponectin plays a protective role in caerulein-induced acute pancreatitis in mice fed a high-fat diet

Predictive value of adipokines for the severity of acute pancreatitis: a meta-analysis

BACKGROUND

Severe acute pancreatitis (SAP) is a dangerous condition with a high mortality rate. Many studies have found an association between adipokines and the development of SAP, but the results are controversial. Therefore, we performed a meta-analysis of the association of inflammatory adipokines with SAP.

METHODS

We screened PubMed, EMBASE, Web of Science and Cochrane Library for articles on adipokines and SAP published before July 20, 2023. The quality of the literature was assessed using QUADAS criteria. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated to assess the combined effect. Subgroup analysis, sensitivity analysis and publication bias tests were also performed on the information obtained.

RESULT

Fifteen eligible studies included 1332 patients with acute pancreatitis (AP). Pooled analysis showed that patients with SAP had significantly higher serum levels of resistin (SMD = 0.78, 95% CI:0.37 to 1.19, z = 3.75, P = 0.000). The difference in leptin and adiponectin levels between SAP and mild acute pancreatitis (MAP) patients were not significant (SMD = 0.30, 95% CI: -0.08 to 0.68, z = 1.53, P = 0.127 and SMD = 0.11, 95% CI: -0.17 to 0.40, z = 0.80, P = 0.425, respectively). In patients with SAP, visfatin levels were not significantly different from that in patients with MAP (SMD = 1.20, 95% CI: -0.48 to 2.88, z = 1.40, P = 0.162).

CONCLUSION

Elevated levels of resistin are associated with the development of SAP. Resistin may serve as biomarker for SAP and has promise as therapeutic target.

Krüppel-like Factor 5 Plays an Important Role in the Pathogenesis of Chronic Pancreatitis

Chronic pancreatitis results in the formation of pancreatic intraepithelial neoplasia (PanIN) and poses a risk of developing pancreatic cancer. Our previous study demonstrated that Krüppel-like factor 5 (KLF5) is necessary for forming acinar-to-ductal metaplasia (ADM) in acute pancreatitis. Here, we investigated the role of KLF5 in response to chronic injury in the pancreas. Human tissues originating from chronic pancreatitis patients showed increased levels of epithelial KLF5. An inducible genetic model combining the deletion of Klf5 and the activation of KrasG12D mutant expression in pancreatic acinar cells together with chemically induced chronic pancreatitis was used. The chronic injury resulted in increased levels of KLF5 in both control and KrasG12D mutant mice. Furthermore, it led to numerous ADM and PanIN lesions and extensive fibrosis in the KRAS mutant mice. In contrast, pancreata with Klf5 loss (with or without KrasG12D) failed to develop ADM, PanIN, or significant fibrosis. Furthermore, the deletion of Klf5 reduced the expression level of cytokines and fibrotic components such as Il1b, Il6, Tnf, Tgfb1, Timp1, and Mmp9. Notably, using ChIP-PCR, we showed that KLF5 binds directly to the promoters of Il1b, Il6, and Tgfb1 genes. In summary, the inactivation of Klf5 inhibits ADM and PanIN formation and the development of pancreatic fibrosis.

Circulating monocytes in acute pancreatitis

Acute pancreatitis is a common gastrointestinal disease characterized by inflammation of the exocrine pancreas and manifesting itself through acute onset of abdominal pain. It is frequently associated with organ failure, pancreatic necrosis, and death. Mounting evidence describes monocytes - phagocytic, antigen presenting, and regulatory cells of the innate immune system - as key contributors and regulators of the inflammatory response and subsequent organ failure in acute pancreatitis. This review highlights the recent advances of dynamic change of numbers, phenotypes, and functions of circulating monocytes as well as their underling regulatory mechanisms with a special focus on the role of lipid modulation during acute pancreatitis.

Effects of low-glycemic index diet on plasma adipokines in obese children

BACKGROUND

A low-glycemic index (GI) diet may modulate adipocyte-produced adipokines linking to insulin resistance.

METHODS

The stored plasma samples from the RCT of a low-GI vs. conventional diet in obese children were analyzed for adipokines: leptin, adiponectin, resistin, and visfatin. Their relationships with clinical outcomes were assessed.

RESULTS

Fifty-two participants completed the 6-month intervention trial (mean age: 12.0 ± 2.0 years, 35 boys). Both groups had significantly decreased BMI z-scores from baseline whereas the low-GI group had significant reduction in fasting insulin and HOMA-IR. There were no differences in adipokines between the groups before and after the intervention. However, there was an association between baseline leptin and the change of fat mass index (FMI) but not the insulin resistance in both groups. The higher the baseline leptin was, the lower the changes were for FMI after the intervention.

CONCLUSION

Despite no demonstrable effect of low-GI diet on plasma adipokines, the higher baseline leptin was correlated with lower reduction of fat mass. Leptin resistance may have a detrimental effect on the reduction of adiposity in obese children. Baseline leptin could be a useful predictor of the change in body composition in an obesity intervention trial.

IMPACT

Leptin resistance may have a detrimental effect in reducing the adiposity in obese children. This study is the first of its kind to compare the plasma adipokine concentrations of obese children on low-GI diet and conventional diet. We found that serum leptin was significantly correlated with the reduction of BMI z-score and FMI in both groups. Baseline leptin could be a useful predictor of the change in body composition in an obesity intervention trial.

Assessment of Acute Pancreatitis Severity and Prognosis with CT-Measured Body Composition

Objective

The aim of this study was to investigate the possible association of muscle and adipose parameters with the severity and prognosis of patients hospitalized with acute pancreatitis (AP).

Methods

A total of 392 hospitalized patients and 309 controls were enrolled in the study analysis from April 1, 2016, to February 1, 2021. The computed tomography scans of each population were evaluated for muscle and adipose parameters. The effects of parameters on developing moderately severe acute pancreatitis (MSAP) or severe acute pancreatitis (SAP) were evaluated using univariate and multivariate logistic regression analyses. Associations with disease recurrence and death were analyzed through Cox regression analysis.

Results

The AP patients had higher levels of visceral adipose tissue (144.25 vs 97.81 cm², p < 0.001) and subcutaneous adipose tissue (135 vs 120 cm², p < 0.001) but lower levels of adipose tissue attenuation (visceral and subcutaneous) and skeletal muscle attenuation (SMA) than the controls (p < 0.05, respectively). Visceral adipose tissue (VAT) and SMA differed significantly with p-values of 0.014 and 0.003 in the different severity groups of AP. In multivariate analysis, VAT and SMA were associated with MSAP or SAP, with odds ratios of 1.003 and 0.973, respectively (95% CI 1.000-1.006, p = 0.041; 95% CI 0.953-0.993, p = 0.010). Cox regression analysis showed that low SMA was strongly associated with an increased mortality in MSAP and SAP patients (HR 10.500, 95% CI 1.344-82.025, p = 0.025). Regression analysis also showed an association of VAT loss of more than 17% with reduced 1-year recurrence of acute pancreatitis (HR 0.427, 95% CI 0.189-0.967, p = 0.041).

Conclusion

VAT and SMA were influential factors for the severity and prognosis of patients with AP. Patients should proper diet and exercise after discharge to reduce VAT and strengthen muscle function to improve prognosis.

Morbid obesity but not obesity is associated with increased mortality in patients undergoing endoscopic retrograde cholangiopancreatography: A national cohort study

Background

The relationship between body weight and outcomes of endoscopic retrograde cholangiopancreatography (ERCP) is unclear.

Objectives

This study aimed to investigate the impact of obesity and morbid obesity on mortality and ERCP‐related complications in patients who underwent ERCP.

Methods

We conducted a US population‐based retrospective cohort study using the Nationwide Readmissions Databases (2013–2014). A total of 159,264 eligible patients who underwent ERCP were identified, of which 137,158 (86.12%) were normal weight, 12,522 (7.86%) were obese, and 9584 (6.02%) were morbidly obese. The primary outcome was in‐hospital mortality. The secondary outcomes were the length of stay, total cost, and ERCP‐related complications. Multivariate analysis and propensity score (PS) matching analysis were performed. The analysis was repeated in a restricted cohort to eliminate confounders.

Results

Patients with morbid obesity, as compared to normal‐weight patients, were associated with a significantly higher in‐hospital mortality (hazard ratio [HR]: 5.54; 95% confidence interval [CI]: 1.23–25.04). Obese patients were not associated with significantly different mortality comparing to normal weight (HR: 1.00; 95% CI: 0.14–7.12). Patients with morbid obesity were also found to have an increased length of hospital stay and total cost. The rate of ERCP‐related complications was comparable among the three groups except for a higher cholecystitis rate after ERCP in obese patients.

Conclusions

Morbid obesity but not obesity was associated with increased mortality, length of stay, and total cost in patients undergoing ERCP.

Established knowledge on this subject

1. Obesity is a prevalent phenomenon.

2. The impact of obesity and morbid obesity on mortality in patients undergoing ERCP remains unclear.

Significant and/or new findings of this study?

1. Morbid obesity but not obesity was associated with increased mortality in patients undergoing ERCP.

Assessment of Computed Tomography-Defined Muscle and Adipose Tissue Features in Relation to Length of Hospital Stay and Recurrence of Hypertriglyceridemic Pancreatitis

Background

Analytic morphometric assessment has recently been proposed to be applied to the study of acute pancreatitis (AP). However, the relationship between body composition and the outcomes of hypertriglyceridemic pancreatitis (HTGP) is still unclear. The aim of this study was to evaluate body composition in relation to the length of hospital stay (LOS) and recurrence of HTGP.

Methods

Patient characteristics, admission examination data, body composition parameters, LOS, and recurrence within 1 year were collected from the institutional pancreatitis database and follow-up records. Logistic regression analysis was used to identify risk factors for LOS and recurrence of HTGP.

Results

Of the 196 included patients, 158 (80.6%) were men and 53 (27.0%) were sarcopenic. The average LOS was 15.83±10.02 days. The recurrence rate of HTGP was 36.7%. Multivariate analysis with multiple linear regression suggested that subcutaneous adipose tissue (SAT) area (p=0.019) and high-density lipoprotein-cholesterol (HDL-C) (p=0.001) were independently associated with the LOS for HTGP after adjusting for age and sex. The multivariate adjusted hazard ratios for SAT area and HDL-C, with respect to the relationship between body parameters and LOS, were 1.008 (95% confidence interval [CI], 1.001–1.015) and 0.090 (95% CI, 0.022–0.361), respectively. No significant differences were observed between the AP and recurrent AP (RAP) groups in terms of characteristics, admission examination data, and body composition parameters.

Conclusion

SAT area and HDL-C are associated with LOS in patients with HTGP. The body composition of patients at the first symptom onset of HTGP cannot predict recurrence.

High Body Mass Index and Central Adiposity Is Associated with Increased Risk of Acute Pancreatitis: A Meta-Analysis

BACKGROUND

Higher body mass index and waist circumference have been associated with increased risk of pancreatitis in several prospective studies; however, the results have not been entirely consistent.

AIMS

We conducted a systematic review and dose-response meta-analysis of prospective studies on adiposity and risk of pancreatitis to clarify this association.

METHODS

PubMed and Embase databases were searched for studies on adiposity and pancreatitis up to January 27, 2020. Prospective studies reporting adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for the association between adiposity and risk of pancreatitis were included, and summary RRs (95% CIs) were calculated using a random effects model.

RESULTS

Ten prospective studies with 5129 cases and 1,693,657 participants were included. The summary RR (95% CI) of acute pancreatitis was 1.18 (95% CI: 1.03-1.35, I² = 91%, n = 10 studies) per 5 kg/m² increase in BMI and 1.36 (95% CI: 1.29-1.43, I² = 0%, n = 3) per 10 cm increase in waist circumference. There was evidence of a nonlinear association between BMI and acute pancreatitis, p_nonlinearity < 0.0001, with a steeper association at higher levels of BMI, but not for waist circumference, p_nonlinearity = 0.19. Comparing a BMI of 35 with a BMI of 22, there was a 58% increase in the RR and there was a fourfold increase in the RR comparing a waist circumference of 110 cm with 69 cm. There was no evidence of publication bias.

CONCLUSIONS

This meta-analysis suggests that both increasing BMI and waist circumference are associated with a dose-response-related increase in the risk of acute pancreatitis.

Adiponectin receptor agonist AdipoRon relieves endotoxin-induced acute hepatitis in mice

BACKGROUND

Adiponectin is the most abundant adipokines that plays critical roles in the maintenance of energy homeostasis as well as inflammation regulation. The half-life of adiponectin is very short and the small-molecule adiponectin receptor agonist has been synthesized recently. In the present study, the potential roles of AdipoRon, an adiponectin receptor agonist, in a mouse model of lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute hepatitis was explored.

METHODS

BALB/c mice (n = 144, male) were divided into three sets. In set 1, 32 mice were randomized into four groups: the control group, the AdipoRon group, the LPS/D-Gal group, and the AdipoRon + LPS/D-Gal group. The mice in set 1 were sacrificed after LPS/D-Gal treatment, and the plasma samples were collected for detection of tumor necrosis factor-alpha (TNF-α). In set 2, the 32 mice were also divided into four groups similar to that of set 1. The mice were sacrificed 6 h after LPS/D-Gal injection and plasma samples and liver were collected. In set 3, 80 mice (divided into four groups, n = 20) were used for survival observation. The survival rate, plasma aminotransferases, histopathological damage were measured and compared between these four groups.

RESULTS

AdipoRon suppressed the elevation of plasma aminotransferases (from 2106.3 ± 781.9 to 286.8 ± 133.1 U/L for alanine aminotransferase, P < 0.01; from 566.5 ± 243.4 to 180.1 ± 153.3 U/L for aspartate aminotransferase, P < 0.01), attenuated histopathological damage and improved the survival rate (from 10% to 60%) in mice with LPS/D-Gal-induced acute hepatitis. Additionally, AdipoRon down-regulated the production of TNF-α (from 328.6 ± 121.2 to 213.4 ± 52.2 pg/mL, P < 0.01), inhibited the activation of caspase-3 (from 2.04-fold to 1.34-fold of the control), caspase-8 (from 2.03-fold to 1.31-fold of the control), and caspase-9 (from 2.14-fold to 1.43-fold of the control), and decreased the level of cleaved caspase-3 (0.28-fold to that of the LPS/D-Gal group). The number of terminal deoxynucleotidyl transferase-mediated nucleotide nick-end labeling-positive apoptotic hepatocytes in LPS/D-Gal-exposed mice also reduced.

CONCLUSIONS

These data indicated that LPS/D-Gal-induced acute hepatitis was effectively attenuated by the adiponectin receptor agonist AdipoRon, implying that AdipoRon might become a new reagent for treatment of acute hepatitis.

Magnesium isoglycyrrhizinate alleviates liver injury in obese rats with acute necrotizing pancreatitis

OBJECTIVE

For patients with acute necrotizing pancreatitis (ANP), a high body mass index (BMI) increases the likelihood of acute hepatic injury (AHI). In the current study, we explored whether magnesium isoglycyrrhizinate (MgIg) could alleviate ANP-induced liver injury in obese rats.

METHODS

Sprague-Dawley (SD) rats were selected for the present study, and the ANP model was established by retrograde injection of 5% sodium taurocholate into the biliary-pancreatic duct. Thirty-six SD rats were randomly assigned to six groups: the normal (N), standard rat chow (SRC) normal (SN), SRC ANP (S-ANP), high-fat diet (HFD) normal (H-N), HFD ANP (H-ANP), and MgIg pretreatment HFD ANP (H-ANPT) groups. The rats in the H-ANPT group were treated with MgIg (30 mg/kg) intragastrically for 7 days before the ANP model was established. The rats were sacrificed 12 h after ANP was established, and the blood and pancreatic and liver tissues were collected. Differences in the physiology, pathology and cellular and molecular responses of the rats in each group were examined.

RESULT

Analyses of serum amylase lipase, alanine aminotransferase and aspartate aminotransferase indicated that obesity aggravated ANP-induced hepatic injury and that MgIg improved liver function. The superoxide dismutase, malondialdehyde, M1 macrophage, M2 macrophage, neutrophil, NF-κB, IL-1β and caspase-3 levels in liver tissue showed that MgIg attenuated H-ANP-induced hepatic injury by inhibiting oxidative stress and inflammation.

CONCLUSION

Obesity aggravated ANP-induced liver injury via oxidative stress and inflammatory reactions. MgIg alleviated oxidative stress and decreased the inflammatory reaction, protecting the liver against the AHI induced by ANP in obese rats.

Association of Statins With Decreased Acute Pancreatitis Severity: A Propensity Score Analysis

BACKGROUND

Statins possess anti-inflammatory properties and have a protective effect in certain inflammatory conditions; however, their effect on the natural history of pancreatitis is unknown.

AIM

The aim of this study is to assess the effect of statin exposure on the severity of pancreatitis and incidence of organ failure using a propensity-matched approach.

METHODS

A historical cohort study was conducted of adult patients with acute pancreatitis (AP) admitted in the Cleveland Clinic Health System between 2007 and 2014. All medication, clinical, and outcomes data were extracted from the electronic medical record. Factors that influence statin use were included in a propensity model to minimize selection bias. Patients on and off statins were matched (1:1) based on the propensity score to simulate a randomized controlled trial. Measured outcomes included pancreatitis severity (Revised Atlanta Classification), incidence of multisystem organ failure (MSOF), new MSOF, acute necrosis, and death. Additional surrogate markers of severity included hospital length of stay, Bedside Index of Severity of Acute Pancreatitis (BISAP), and presence of SIRS.

RESULTS

A total of 110 subjects taking a statin at admission were matched with 210 subjects not on a statin. Known baseline factors that may influence statin use and severity of pancreatitis were evenly matched between the 2 groups. Patients on a statin were less likely to develop MSOF, severe AP and necrosis. Although less in-hospital death occurred in the statin group when compared to nonusers, the difference was not statistically significant (2% vs. 4%; P=0.38).

CONCLUSIONS

Statin use is associated with decreased severity of AP observed as reduction in both overall MSOF incidence and new MSOF. Prospective randomized controlled trials are needed to determine the efficacy of statin drugs in the treatment of AP.

Role of obesity in the release of extracellular nucleosomes in acute pancreatitis: a clinical and experimental study

BACKGROUND/OBJECTIVES

A high body mass index increases the risk of severe pancreatitis and associated mortality. Our aims were: (1) To determine whether obesity affects the release of extracellular nucleosomes in patients with pancreatitis; (2) To determine whether pancreatic ascites confers lipotoxicity and triggers the release of extracellular nucleosomes in lean and obese rats.

METHODS

DNA and nucleosomes were determined in plasma from patients with mild or moderately severe acute pancreatitis either with normal or high body mass index (BMI). Lipids from pancreatic ascites from lean and obese rats were analyzed and the associated toxicity measured in vitro in RAW 264.7 macrophages. The inflammatory response, extracellular DNA and nucleosomes were determined in lean or obese rats with pancreatitis after peritoneal lavage.

RESULTS

Nucleosome levels in plasma from obese patients with mild pancreatitis were higher than in normal BMI patients; these levels markedly increased in obese patients with moderately severe pancreatitis vs. those with normal BMI. Ascites from obese rats exhibited high levels of palmitic, oleic, stearic, and arachidonic acids. Necrosis and histone 4 citrullination-marker of extracellular traps-increased in macrophages incubated with ascites from obese rats but not with ascites from lean rats. Peritoneal lavage abrogated the increase in DNA and nucleosomes in plasma from lean or obese rats with pancreatitis. It prevented fat necrosis and induction of HIF-related genes in lung.

CONCLUSIONS

Extracellular nucleosomes are intensely released in obese patients with acute pancreatitis. Pancreatitis-associated ascitic fluid triggers the release of extracellular nucleosomes in rats with severe pancreatitis.

Isoliquiritigenin Ameliorates Acute Pancreatitis in Mice via Inhibition of Oxidative Stress and Modulation of the Nrf2/HO-1 Pathway

Oxidative stress plays a crucial role in the pathogenesis of acute pancreatitis (AP). Isoliquiritigenin (ISL) is a flavonoid monomer with confirmed antioxidant activity. However, the specific effects of ISL on AP have not been determined. In this study, we aimed to investigate the protective effect of ISL on AP using two mouse models. In the caerulein-induced mild acute pancreatitis (MAP) model, dynamic changes in oxidative stress injury of the pancreatic tissue were observed after AP onset. We found that ISL administration reduced serum amylase and lipase levels and alleviated the histopathological manifestations of pancreatic tissue in a dose-dependent manner. Meanwhile, ISL decreased the oxidative stress injury and increased the protein expression of the Nrf2/HO-1 pathway. In addition, after administering a Nrf2 inhibitor (ML385) or HO-1 inhibitor (zinc protoporphyrin) to block the Nrf2/HO-1 pathway, we failed to observe the protective effects of ISL on AP in mice. Furthermore, we found that ISL mitigated the severity of pancreatic tissue injury and pancreatitis-associated lung injury in a severe acute pancreatitis model induced by L-arginine. Taken together, our data for the first time confirmed the protective effects of ISL on AP in mice via inhibition of oxidative stress and modulation of the Nrf2/HO-1 pathway.

Pravastatin improves risk factors but not ischaemic tolerance in obese rats

Statins are effective in management of dyslipidaemia, and a cornerstone of CVD prevention strategies. However, the impacts of their pleiotropic effects on other cardiovascular risk factors and myocardial responses to infarction are not well characterised. We hypothesised that pravastatin treatment in obesity improves lipid profiles, insulin-resistance and myocardial resistance to ischaemia/reperfusion (I/R) injury. Wistar rats were fed a control (C) chow or high carbohydrate and fat diet (HCFD) for 16 weeks with vehicle or pravastatin (prava 7.5 mg/kg/day) treatment for 8 weeks. At 16 weeks HOMAs were performed, blood samples collected and hearts excised for Langendorff perfusions/biochemical analyses. Anti-oxidant activity and proteins regulating mitochondrial fission/fusion and apoptosis were assessed. The HCFD increased body weight (736±15 vs. 655±12 g for C; P<0.001), serum triglycerides (2.91±0.52 vs. 1.64±0.26 mmol/L for C; P<0.001) and insulin-resistance (HOMA- 6.9±0.8 vs. 4.2±0.5 for C; P<0.05) while prava prevented diet induced changes and paradoxically increased lipid peroxidation. The HCFD increased infarct size (34.1±3.1% vs. 18.8±3.0% of AAR for C; P<0.05), which was unchanged by prava in C and HCFD animals. The HCFD decreased cardiac TxR activity and mitochondrial MFN-1 and increased mitochondrial DRP-1 (reducing MFN-1:DRP-1 ratio) and Bax expression, with the latter changes prevented by prava. While unaltered by diet, cytosolic levels of Bax and caspase-3 were reduced by prava in C and HCFD hearts (without changes in cleaved caspase-3). We conclude that obesity, hyper-triglyceridemia and impaired glycemic control in HCFD rats are countered by prava. Despite improved risk factors, prava did not reduce myocardial infarct size, potentially reflecting its complex pleiotropic impacts on cardiac GPX activity and MFN-1, DRP-1, caspase-3 and Bcl-2 proteins.

Visceral Adiposity Predicts Severity of Acute Pancreatitis

OBJECTIVES

The aim of this study was to determine the association of visceral adiposity with severe outcomes in acute pancreatitis (AP).

METHODS

This retrospective study included consecutive patients with AP admitted to a tertiary care hospital between January 2010 and January 2015 who underwent a computed tomography scan. The visceral adipose tissue (VAT) volume was estimated using the method of Linder and colleagues. Multivariable logistic regression analysis was conducted to assess VAT as a predictor of severe AP compared with other validated predictors of severity.

RESULTS

Five hundred and seventy four patients were admitted during the study period, of which 252 had a computed tomography scan available. Patients with severe AP had a larger VAT area compared with those with mild or moderate AP (mean: 184.9 cm vs 79.9 cm, P = 0.006). Patients who developed multisystem organ failure or had acute necrotic collections had a larger VAT area than those who did not (150.6 cm vs 91.0 cm, P = 0.004 and 174.0 cm vs 91.9 cm, P = 0.003, respectively). Visceral adipose tissue area demonstrated superior discrimination of severe AP compared with other severity predictors.

CONCLUSIONS

Increased VAT area is a strong predictor of severe pancreatitis, necrosis, and multisystem organ failure.

The role of hypertriglyceridemia for acute kidney injury in the course of acute pancreatitis and an animal model

OBJECTIVE

The aim of this study was to investigate the role of hypertriglyceridemia for acute kidney injury (AKI) in the course of acute pancreatitis.

METHODS

Patients with acute pancreatitis were retrospectively divided into four groups according to admission triglyceride: normal group, mild HTG group, moderate HTG group and severe HTG group. Clinical characteristics were compared among these groups. Wild type (WT) mice and Human ApoC III transgenic (ApoCIIItg) mice were used in the next animal experiments. Severe acute pancreatitis (SAP) model was established by retrograde injection of 0.5% sodium taurocholate (0.1 ml/100 g) from duodenum to pancreatic duct. Histological scores, serum amylase, creatinine, usea nitrogen were compared between WT mice and ApoCIIItg mice.

RESULTS

Two hundred and sixty-two patients were classified into 4 groups: normal TG (104, 39.7%), mild HTG (72, 27.5%), moderate HTG (47, 17.9%), and severe HTG (39, 14.9%) groups. The proportions of AKI were 13.5% (14/104, normal), 13.9% (10/72, mild), 21.3% (10/47, moderate), and 38.5% (15/39, severe), respectively. After establishing SAP model, the levels of serum amylase (P < 0.05) and pancreatic histological score (P < 0.05) of ApoCIII-SAP-9h group were significantly higher than that of WT-SAP-9h group, respectively. ApoCIII-SAP-9h group had significantly higher levels of serum creatinine (P < 0.001), usea nitrogen (P < 0.001), and kidney histological score (P < 0.05) than that of WT-SAP-9h group, respectively.

CONCLUSIONS

Mild HTG has little adverse impact on disease severity of acute pancreatitis; severe HTG can aggravate kidney injury in the course of acute pancreatitis. ApoCIII-SAP mice have more serious pancreatic damage and kidney injury than WT-SAP mice.

Obesity with abundant subcutaneous adipose tissue increases the risk of post-ERCP pancreatitis

BACKGROUND/PURPOSE

The risk factors for post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) have been widely investigated. However, studies focusing on the body mass index (BMI) and distribution of adipose tissue have not been reported. Therefore, we examined the correlation between PEP and these factors.

METHODS

A total of 583 consecutive endoscopic retrograde cholangiopancreatography (ERCP)-naïve patients undergoing therapeutic ERCP were retrospectively analyzed. Subjects were categorized into four groups by BMI: underweight, normal, overweight, and obesity; the PEP rates were compared. In addition, the relationship between PEP and parameters of obesity, visceral and subcutaneous adipose tissue as well as abdominal circumference was investigated.

RESULTS

PEP rate was significantly higher in obesity (30 %) and lower in normal (3 %, P < 0.001). The PEP rate in underweight (7.3 %) was conversely higher than in normal. As for parameters of obesity, only subcutaneous adipose tissue was correlated with PEP incidence (P = 0.009). The correlation of PEP incidence with BMI and subcutaneous adipose tissue was separately reconfirmed by multivariate analysis including female gender and guidewire placement; these factors showed a tendency toward differences in univariate analysis.

CONCLUSIONS

Obesity could be a risk factor for PEP. In the obesity group, an excess of subcutaneous adipose tissue might be an especially important factor related to PEP incidence.

Translational Insights Into Peroxisome Proliferator-Activated Receptors in Experimental Acute Pancreatitis

Acute pancreatitis (AP) is an inflammatory disorder of the exocrine pancreas frequently associated with metabolic causes, contributing factors, or consequences, including hypertriglyceridemia, obesity, and disorders of intermediary metabolism, respectively. To date, there is no specific therapy for this disease. Future optimal therapy should correct both inflammatory and metabolic components of the disease. Peroxisome proliferator-activated receptors (PPARs) are lipid-sensing nuclear receptors that control inflammatory and metabolic pathways via ligand-dependent and ligand-independent mechanisms. There are 3 known subtypes, PPAR-α, PPAR-β/δ, and PPAR-γ, which are differentially expressed in various tissues. The PPARs interact closely with other transcription factors such as nuclear factor κB and signal tranducers and activators of transcription that have pivotal roles in the pathobiology of AP. In this comprehensive review, we summarize the role of PPARs in AP, highlighting important in vitro and in vivo experimental findings. Finally, we propose future research directions as well as potential translational use of PPAR agonists in the treatment of AP.

Associations of Adiponectin with Adiposity, Insulin Sensitivity, and Diet in Young, Healthy, Mexican Americans and Non-Latino White Adults

Low circulating adiponectin levels may contribute to higher diabetes risk among Mexican Americans (MA) compared to non-Latino whites (NLW). Our objective was to determine if among young healthy adult MAs have lower adiponectin than NLWs, independent of differences in adiposity. In addition, we explored associations between adiponectin and diet. This was an observational, cross-sectional study of healthy MA and NLW adults living in Colorado (U.S.A.). We measured plasma total adiponectin, adiposity (BMI, and visceral adipose tissue), insulin sensitivity (IVGTT), and self-reported dietary intake in 43 MA and NLW adults. Mean adiponectin levels were 40% lower among MA than NLW (5.8 ± 3.3 vs. 10.7 ± 4.2 µg/mL, p = 0.0003), and this difference persisted after controlling for age, sex, BMI, and visceral adiposity. Lower adiponectin in MA was associated with lower insulin sensitivity (R² = 0.42, p < 0.01). Lower adiponectin was also associated with higher dietary glycemic index, lower intake of vegetables, higher intake of trans fat, and higher intake of grains. Our findings confirm that ethnic differences in adiponectin reflect differences in insulin sensitivity, but suggest that these are not due to differences in adiposity. Observed associations between adiponectin and diet support the need for future studies exploring the regulation of adiponectin by diet and other environmental factors.

Effect of different doses of quercetin on pancreatic pathology in rats with hypertriglyceridemia related acute pancreatitis

AIM: To investigate the effect of different doses of quercetin on the pancreatic pathology in rats with cerulein-induced acute pancreatitis (AP) associated with hypertriglyceridemia (HTG).

METHODS: Seventy-two male SD rats were randomly divided into 12 groups: HTG group (n = 6, fed a high-fat diet for 2 wk: 77% normal chow + 3% cholesterol + 20% lard), HTG + AP group (n = 6, after 2 wk of a high-fat diet, AP was induced by peritoneal injection of 50 μg/kg cerulein twice at 1-h interval), HTG + AP + quercetin groups [n = 24, divided into 4 groups (6 rats each), quercetin (50, 100, 150, 200 mg/kg) was administered to rats by peritoneal injection after AP induction], normal blood lipid group (n = 6, fed normal chow for 2 wk), normal blood lipid + AP group (n = 6, after 2 wk of normal chow, AP was induced by peritoneal injection of 50 μg/kg cerulein twice at 1-h interval), normal blood lipid + AP + quercetin groups [n = 24, divided into 4 groups (6 rats each), quercetin (50, 100, 150, 200 mg/kg) was administered to rats by peritoneal injection after AP induction]. All rats were sacrificed 9 h after AP induction. Plasma levels of amylase were tested and the pathological changes of pancreatic tissues were observed.

RESULTS: After two weeks of a high-fat diet, serum levels of triglyceride and total cholesterol were much higher than those in rats given normal chow (P < 0.001). Compared with the normal blood lipid + AP group, plasma level of amylase was significantly higher (23670.00 U/L ± 2053.13 U/L vs 13136.00 U/L ± 3536.95 U/L) and pancreatic tissue injury was significantly more serious in the HTG + AP group (9.75 ± 0.94 vs 5.92 ± 1.32) (P = 0.022; P < 0.001). Quercetin intervention groups showed significantly lower levels of amylase and less serious pancreatic tissue injury; the effect was dose-dependent. This protective effect of quercetin was more obvious in the HTG + AP group than in the AP group (HTG + AP + 100, 150, 200 mg/kg quercetin group vs HTG + AP group total histopathological scores: P < 0.001 for all; normal blood lipid + AP + 100, 150, 200 mg/kg quercetin group vs normal blood lipid + AP group total histopathological scores: P = 0.084, P = 0.003, P < 0.001), particularly in acinar necrosis and inflammatory infiltration (HTG + AP + 100, 150, 200 mg/kg quercetin group vs HTG + AP group necrosis score: P < 0.001 for all; inflammatory infiltration: P = 0.008, P = 0.006, P = 0.001).

CONCLUSION: Quercetin could significantly ameliorate the pancreatic pathology in rats with HTG related AP, especially acinar necrosis and inflammatory infiltration. The protective effect is dose-dependent.

Serum adipokine concentrations in dogs with acute pancreatitis

Background

Limited information is available about the role of adipokines in the development and progression of acute pancreatitis (AP) in dogs.

Objectives

To determine whether the circulating concentrations of adipokines differed between healthy dogs and dogs with AP, and whether the circulating concentrations differed between AP survivors and AP nonsurvivors.

Animals

Twenty‐eight healthy dogs and 25 client‐owned dogs with AP.

Methods

Prospective observational cohort study of 25 client‐owned dogs with newly diagnosed AP and 28 otherwise healthy dogs with similar body condition scores. The serum concentrations of leptin, adiponectin, resistin, visfatin, interleukin (IL)‐1β, IL‐6, IL‐10, IL‐18, and tumor necrosis factor (TNF)‐α were measured.

Results

The serum concentrations of leptin (P = .0021), resistin (P = .0010), visfatin (P < .0001), IL‐1β (P < .0001), IL‐6 (P = .0002), IL‐10 (P < .0001), and IL‐18 (P < .0001) were significantly higher in dogs with AP than healthy dogs, whereas the adiponectin concentration (P = .0011) was significantly lower. There were significant differences in the serum concentrations of leptin (P = .028) and adiponectin (P = .046) in survivors and nonsurvivors. After the disappearance of clinical signs, the concentrations of resistin (P = .037) and IL‐1β (P = .027) decreased significantly, whereas the serum concentrations of leptin (P > .999), adiponectin (P = .11), visfatin (P = .83), IL‐6 (P = .82), IL‐10 (P = .82), IL‐18 (P = .56), and TNF‐α (P = .94) did not differ significantly.

Conclusion and Clinical Importance

This study showed that dysregulation of adipokines might be involved in the pathogenesis of AP. In addition, leptin and adiponectin are likely to be associated with mortality rate in AP.

Inhibition of the nucleotide-binding domain, leucine-rich containing family, pyrin-domain containing 3 inflammasome reduces the severity of experimentally induced acute pancreatitis in obese mice

Acute pancreatitis (AP), although most often a mild and self-limiting inflammatory disease, worsens to a characteristically necrotic severe acute pancreatitis (SAP) in about 20% of cases. Obesity, affecting more than one-third of American adults, is a risk factor for the development of SAP, but the exact mechanism of this association has not been identified. Coincidental with chronic low-grade inflammation, activation of the nucleotide-binding domain, leucine-rich containing family, pyrin-domain containing 3 (NLRP3) inflammasome increases with obesity. Lean mice genetically deficient in specific components of the NLRP3 inflammasome are protected from experimentally induced AP, indicating a direct involvement of this pathway in AP pathophysiology. We hypothesized that inhibition of the NLRP3 inflammasome with the sulfonylurea drug glyburide would reduce disease severity in obese mice with cerulein-induced SAP. Treatment with glyburide led to significantly reduced relative pancreatic mass and water content and less pancreatic damage and cell death in genetically obese ob/ob mice with SAP compared with vehicle-treated obese SAP mice. Glyburide administration in ob/ob mice with cerulein-induced SAP also resulted in significantly reduced serum levels of interleukin 6, lipase, and amylase and led to lower production of lipopolysaccharide-stimulated interleukin 1β release in cultured peritoneal cells, compared with vehicle-treated ob/ob mice with SAP. Together, these data indicate involvement of the NLRP3 inflammasome in obesity-associated SAP and expose the possible utility of its inhibition in prevention or treatment of SAP in obese individuals.

Therapeutic administration of orlistat, rosiglitazone, or the chemokine receptor antagonist RS102895 fails to improve the severity of acute pancreatitis in obese mice

OBJECTIVE

Currently, there is no therapy for severe acute pancreatitis (AP) except for supportive care. The lipase inhibitor orlistat, the peroxisome proliferator-activated receptor γ agonist rosiglitazone, and the chemokine receptor 2 antagonists attenuate the severity of AP in rodents if administered before or at the time of induction of pancreatitis. However, it is unknown whether these treatments are effective if administered therapeutically after induction of pancreatitis.

METHODS

Male C57BL6 mice with diet-induced obesity received 2 injections of mrIL-12 (150 ng per mouse) and mrIL-18 (750 ng per mouse) intraperitoneally at 24-hour intervals. The mice were injected 2, 24, and 48 hours after the second injection of IL-12 + IL-18 with orlistat (2 mg per mouse), rosiglitazone (0.4 mg per mouse), RS102895 (0.3 mg per mouse), or vehicle (20 μL of DMSO and 80 μL of canola oil) and euthanized after 72 hours.

RESULTS

Orlistat decreased intra-abdominal fat necrosis compared with vehicle (P < 0.05). However, none of the drug treatments produced significant decreases in pancreatic edema, acinar necrosis, or intrapancreatic fat necrosis.

CONCLUSIONS

Drugs previously shown to improve the severity of AP when given before or at the time of induction of pancreatitis failed to do so when administered therapeutically in the IL-12 + IL-18 model.

Adiponectin inhibits murine pancreatic cancer growth

BACKGROUND

Adiponectin is an adipose tissue-derived secretory hormone whose plasma concentrations are lower in obese individuals. Obesity is a risk factor for the development and growth of pancreatic cancer, and hypoadiponectinemia was suggested to be involved in the growth of Pan02 murine pancreatic cancer cells that were inoculated into the flanks of congenitally obese mice.

AIM

The aim of this study was to clarify the role of adiponectin in the growth of pancreatic cancer cells.

METHODS

We examined the effect of adiponectin on the growth of Pan02 cells using recombinant adiponectin and adiponectin knockout mice.

RESULTS

The in vitro treatment of Pan02 cells with adiponectin inhibited cellular proliferation that was accompanied by increased apoptosis and caspase-3 and caspase-7 activities. Transplantation of Pan02 cells into the pancreas of knockout mice resulted in a larger tumor volume with fewer terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) positive cells compared with wild-type mice.

CONCLUSIONS

The results indicate that adiponectin directly suppresses the proliferation of Pan02 cells.

High dietary glycemic load increases the risk of non-gallstone-related acute pancreatitis: a prospective cohort study

BACKGROUND & AIMS

Obesity and type 2 diabetes--diseases linked to glucose intolerance and insulin resistance--have been positively associated with the risk of acute pancreatitis. However, it is unclear whether consumption of foods that increase postprandial glycemia and insulinemia have similar associations. We examined the association between dietary glycemic load and risk of non-gallstone-related acute pancreatitis.

METHODS

We performed a prospective study of 44,791 men and 36,309 women (aged 45-84 years), without a history of acute pancreatitis, from the Cohort of Swedish Men and the Swedish Mammography Cohort. Glycemic loads were calculated from food frequency questionnaire data collected in 1997, and participants were followed for the development of non-gallstone-related acute pancreatitis through 2010 via linkage to the Swedish National Patient Register. Hazard ratios (HRs) were estimated using Cox proportional hazard models.

RESULTS

During a total follow-up of 967,568 person-years, there were 364 cases of incident non-gallstone-related acute pancreatitis (236 in men and 128 in women). Incidence rates, standardized for age and sex, were 49 cases per 100,000 person-years in the highest quartile of glycemic load and 33 cases per 100,000 person-years in the lowest. The multivariate-adjusted HR of non-gallstone-related acute pancreatitis was 1.60 (95% confidence interval [CI], 1.17-2.18) for the highest compared with the lowest quartile. Every 50-unit increase in glycemic load per day (∼ 3 servings of white bread) had an HR of 1.38 in men (95% CI, 1.11-1.72) and women (95% CI, 1.02-1.86).

CONCLUSIONS

Based on a large, prospective cohort study, diets with high glycemic load are associated with an increased risk of non-gallstone-related acute pancreatitis.

Adiponectin as a routine clinical biomarker

Adiponectin is a protein synthesized and secreted predominantly by adipocytes into the peripheral blood. However, circulating adiponectin level is inversely related with body weight, especially visceral fat accumulation. The mechanism of this paradoxical relation remains obscure. Low circulating adiponectin concentrations (hypoadiponectinemia; <4 μg/mL) are associated with a variety of diseases, including dysmetabolism (type 2 diabetes, insulin resistance, hypertension, dyslipidemia, metabolic syndrome, hyperuricemia), atherosclerosis (coronary artery disease, stroke, peripheral artery disease), sleep apnea, non-alcoholic fatty liver disease, gastritis and gastro-esophageal reflux disease, inflammatory bowel diseases, pancreatitis, osteoporosis, and cancer (endometrial cancer, postmenopausal breast cancer, leukemia, colon cancer, gastric cancer, prostate cancer). On the other hand, hyperadiponectinemia is associated with cardiac, renal and pulmonary diseases. This review article focuses on the significance of adiponectin as a clinical biomarker of obesity-related diseases. Routine measurement of adiponectin in patients with lifestyle-related diseases is highly recommended.

Lipotoxicity of palmitic Acid on neural progenitor cells and hippocampal neurogenesis

Lipotoxicity involves pathological alterations to cells and tissues in response to elevated fat levels in blood. Furthermore, this process can disturb both cellular homeostasis and viability. In the current study, the authors show that neural progenitor cells (NPCs) are vulnerable to high levels of palmitic acid (PA) a saturated fatty acid. PA was found to cause cell death associated with elevated reactive oxygen species (ROS) levels, and to reduce NPCs proliferation. To evaluate the lipotoxicity of PA in adult NPCs in the hippocampus, male C57BL/6 mice were divided into two groups and maintained on either a normal diet (ND) or PA-rich high fat diet (HFD) for 2 weeks. Interestingly, short-term PA-rich HFD feeding reduced the survival of newly generated cells in the hippocampal dentate gyrus and hippocampal brain-derived neurotrophic factor levels. These findings suggest PA has a potent lipotoxicity in NPCs and that a PA-rich HFD disrupts hippocampal neurogenesis.

Adiponectin in inflammatory and immune-mediated diseases

Circulating levels of adiponectin (APN) are reduced in obesity and associated comorbidities, with inflammation playing an important role in downregulating APN production. In contrast to obesity and metabolic disease, elevated systemic and local levels of APN are present in patients with inflammatory and immune-mediated diseases, including autoimmune and pulmonary conditions, heart and kidney failure, viral hepatitis, organ transplantation and perhaps critical illness. A positive association between inflammation and APN is usually reported in inflammatory/immune pathologies, in contrast with the negative correlation typical of metabolic disease. This review discusses the role of APN in modulation of inflammation and immunity and the potential mechanisms leading to increased levels of APN in inflammatory/immune diseases, including modification of adipose tissue physiology; relative contribution of different tissues and adipose depots; hormonal, pharmacological, nutritional and life style factors; the potential contribution of the microbiota as well as the role of altered APN clearance and release from T-cadherin-associated tissue reservoirs. Potential reasons for some of the apparently contradictory findings on the role of APN as a modulator of immunity and inflammation are also discussed, including a comparison of types of recombinant APN used for in vitro studies and strain-dependent differences in the phenotype of APN KO mice.

Abdominal and total adiposity and the risk of acute pancreatitis: a population-based prospective cohort study

OBJECTIVES

Previous research has indicated that obesity may be linked to the severity of acute pancreatitis. However, the association between abdominal and total adiposity as risk factors in the development of acute pancreatitis in a general population has not been studied.

METHODS

A follow-up study was conducted, using the Swedish Mammography Cohort and the Cohort of Swedish Men, to examine the association between waist circumference and body mass index (BMI) and the risk of first-time acute pancreatitis. Severe acute pancreatitis was defined as hospital stay of >14 days, in-hospital death, or mortality within 30 days of discharge. Cox proportional hazards models were used to estimate rate ratios (RRs) with 95% confidence intervals (CIs), adjusted for confounders.

RESULTS

In total, 68,158 individuals, aged 46-84 years, were studied for a median of 12 years. During this time, 424 persons developed first-time acute pancreatitis. The risk of acute pancreatitis among those with a waist circumference of >105 cm was twofold increased (RR=2.37; 95% CI: 1.50-3.74) compared with individuals with a waist circumference of 75.1-85.0 cm, when adjusted for confounders. This association was seen in patients with non-gallstone-related and gallstone-related acute pancreatitis. The results remained unchanged when stratifying the analyses with regards to sex or the severity of acute pancreatitis. There was no association between BMI and the risk of acute pancreatitis.

CONCLUSIONS

Abdominal adiposity, but not total adiposity, is an independent risk factor for the development of acute pancreatitis.

Adipokine levels in the course of mild biliary pancreatitis

OBJECTIVES

Obesity markedly increases the risk of severe acute pancreatitis (AP). Several adipokines have been ascribed a role as a predictor of clinical severity in AP. Therefore, the aim of this study was to investigate a possible relationship between leptin and adiponectin and mild biliary AP.

METHODS

We included 24 consecutive patients with mild biliary AP and 24 consecutive healthy age- and sex-matched controls. Clinical severity was classified by the Ranson score. ELISA was used to assess leptin and adiponectin levels on admission and in remission. Complete blood cell counts and other laboratory tests were also performed at baseline and in remission.

RESULTS

Leptin, adiponectin, insulin and HOMA-IR measurements showed no difference in pancreatitis patients both on admission and in remission compared to the control group. No difference was found in leptin, insulin or HOMA-IR levels in the course of pancreatitis. However, adiponectin levels were higher in remission compared to admission.

CONCLUSIONS

Increased adiponectin levels in remission may be an indication of improvement in this condition. Further studies are needed to determine whether adiponectin provides protection from AP.

Prevention of severe acute pancreatitis with octreotide in obese patients: a prospective multi-center randomized controlled trial

OBJECTIVES

To evaluate the efficacy of octreotide in preventing severe acute pancreatitis (SAP) in obese patients.

METHODS

A prospective multi-center partly randomized control trial was conducted in patients with mild acute pancreatitis (AP). Nonobese patients received conventional management (nonobese-C, n = 82), whereas obese patients (body mass index ≥ 25 kg/m(2)) were randomized into 2 groups: obese-C (n = 79), who received conventional management, and obese-C+O (n = 82), who received conventional management plus intravenous infusion of octreotide, 50 μg/h for 72 hours.

RESULTS

The risk ratio and relative risk reduction in the development of SAP in the obese-C+O group were 0.27 (95% confidence interval, 0.10-0.69) and 0.73 (95% confidence interval, 0.31-0.90), respectively. The number of cases developing local complications in the obese-C+O group was significantly smaller than that in the obese-C group: 4.9% vs 19%, P = 0.006. The plasma level of somatostatin in the obese-C+O group was significantly higher than that in the obese-C group: 165.5 ± 42.6 vs 112.1 ± 24.86 pg/mL, P < 0.05. Supplement of octreotide also accompanied with reduction in plasma levels of tumor necrosis factor α and IL-6.

CONCLUSIONS

Intravenous administration of octreotide (50 μg/h) for 72 hours in the early stage of AP could prevent the development of SAP effectively in obese patients by raising plasma somatostatin to a normal level and reducing circulating cytokines.

Obese rats exhibit high levels of fat necrosis and isoprostanes in taurocholate-induced acute pancreatitis

BACKGROUND

Obesity is a prognostic factor for severity in acute pancreatitis in humans. Our aim was to assess the role of oxidative stress and abdominal fat in the increased severity of acute pancreatitis in obese rats.

METHODOLOGY

Taurocholate-induced acute pancreatitis was performed in lean and obese Zucker rats. Levels of reduced glutathione, oxidized glutathione, L-cysteine, cystine, and S-adenosylmethionine were measured in pancreas as well as the activities of serine/threonine protein phosphatases PP1 and PP2A and tyrosin phosphatases. Isoprostane, malondialdehyde, triglyceride, and free fatty acid levels and lipase activity were measured in plasma and ascites. Lipase activity was measured in white adipose tissue with and without necrosis and confirmed by western blotting.

FINDINGS

Under basal conditions obese rats exhibited lower reduced glutathione levels in pancreas and higher triglyceride and free fatty acid levels in plasma than lean rats. S-adenosyl methionine levels were markedly increased in pancreas of obese rats. Acute pancreatitis in obese rats led to glutathione oxidation and lower reduced glutathione levels in pancreas together with decreased activities of redox-sensitive phosphatases PP1, and PP2A. S-adenosyl methionine levels decreased but cystine levels increased markedly in pancreas upon pancreatitis. Acute pancreatitis triggered an increase in isoprostane levels in plasma and ascites in obese rats. Free fatty acid levels were extremely high in pancreatitis-associated ascitic fluid from obese rats and lipase was bound with great affinity to white adipose tissue, especially to areas of necrosis.

CONCLUSIONS

Our results show that oxidative stress occurs locally and systemically in obese rats with pancreatitis favouring inactivation of protein phosphatases in pancreas, which would promote up-regulation of pro-inflammatory cytokines, and the increase of isoprostanes which might cause powerful pulmonary and renal vasoconstriction. Future studies are needed to confirm the translational relevance of the present findings obtained in a rat model of taurocholate-induced pancreatic damage and necrosis.

Involvement of inflammatory factors in pancreatic carcinogenesis and preventive effects of anti-inflammatory agents

Chronic inflammation is known to be a risk for many cancers, including pancreatic cancer. Heavy alcohol drinking and cigarette smoking are major causes of pancreatitis, and epidemiological studies have shown that smoking and chronic pancreatitis are risk factors for pancreatic cancer. Meanwhile, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are elevated in pancreatitis and pancreatic cancer tissues in humans and in animal models. Selective inhibitors of iNOS and COX-2 suppress pancreatic cancer development in a chemical carcinogenesis model of hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). In addition, hyperlipidemia, obesity, and type II diabetes are also suggested to be associated with chronic inflammation in the pancreas and involved in pancreatic cancer development. We have shown that a high-fat diet increased pancreatic cancer development in BOP-treated hamsters, along with aggravation of hyperlipidemia, severe fatty infiltration, and increased expression of adipokines and inflammatory factors in the pancreas. Of note, fatty pancreas has been observed in obese and/or diabetic cases in humans. Preventive effects of anti-hyperlipidemic/anti-diabetic agents on pancreatic cancer have also been shown in humans and animals. Taking this evidence into consideration, modulation of inflammatory factors by anti-inflammatory agents will provide useful data for prevention of pancreatic cancer.

Rosiglitazone improves survival and hastens recovery from pancreatic inflammation in obese mice

Obesity increases severity of acute pancreatitis (AP) by unclear mechanisms. We investigated the effect of the PPAR-gamma agonist rosiglitazone (RGZ, 0.01% in the diet) on severity of AP induced by administration of IL-12+ IL-18 in male C57BL6 mice fed a low fat (LFD) or high fat diet (HFD), under the hypothesis that RGZ would reduce disease severity in HFD-fed obese animals. In both LFD and HFD mice without AP, RGZ significantly increased body weight and % fat mass, with significant upregulation of adiponectin and suppression of erythropoiesis. In HFD mice with AP, RGZ significantly increased survival and hastened recovery from pancreatic inflammation, as evaluated by significantly improved pancreatic histology, reduced saponification of visceral adipose tissue and less severe suppression of erythropoiesis at Day 7 post-AP. This was associated with significantly lower circulating and pancreas-associated levels of IL-6, Galectin-3, osteopontin and TIMP-1 in HFD + RGZ mice, particularly at Day 7 post-AP. In LFD mice with AP, RGZ significantly worsened the degree of intrapancreatic acinar and fat necrosis as well as visceral fat saponification, without affecting other parameters of disease severity or inflammation. Induction of AP lead to major suppression of adiponectin levels at Day 7 in both HFD and HFD + RGZ mice. In conclusion, RGZ prevents development of severe AP in obese mice even though it significantly increases adiposity, indicating that obesity can be dissociated from AP severity by improving the metabolic and inflammatory milieu. However, RGZ worsens selective parameters of AP severity in LFD mice.

Protective role of adiponectin against ethanol-induced gastric injury in mice

Adiponectin is an anti-inflammatory molecule released from adipocytes, and serum adiponectin concentrations are reduced in obesity. We previously reported that gastric erosion occurs in association with obesity and low serum adiponectin levels. In the present study, we examined adiponectin-knockout (APN-KO) mice to elucidate the role of adiponectin in gastric mucosal injury. Gastric injury was induced by oral administration of ethanol in wild-type (WT) and APN-KO mice. Ethanol treatment induced severe gastric injury in APN-KO mice compared with WT mice. In APN-KO mice, increased apoptotic cells and decreased expression of prostaglandin E(2) (PGE(2)) were detected in the injured stomach. We next assessed the effect of adiponectin on the cellular response to ethanol treatment and wound repair in rat gastric mucosal cells (RGM1). Adiponectin induced the expression of PGE(2) and cyclooxygenase 2 (COX-2) in ethanol-treated RGM1 cells. RGM1 cells exhibited efficient wound repair accompanied by increased PGE(2) expression in the presence of adiponectin. Coadministration of adiponectin with celecoxib, a COX-2 inhibitor, inhibited efficient wound repair. These findings indicate that adiponectin has a protective role against ethanol-induced gastric mucosal injury in mice. This effect may be partially mediated by the efficient wound repair of epithelial cells via increased PGE(2) expression.

Association of low serum adiponectin levels with erosive esophagitis in men: an analysis of 2405 subjects undergoing physical check-ups

BACKGROUND

Obesity is a risk factor for gastro-esophageal reflux disease (GERD). It is generally considered that intra-abdominal pressure in obese subjects is involved in the pathogenesis of GERD through acid exposure to the esophagus. Recently, visceral fat has been recognized as an endocrine organ that secretes various adipocytokines including adiponectin. The aim of this study was to elucidate the relation between adiponectin and erosive esophagitis.

METHODS

This was a cross-sectional retrospective observational study: 2405 consecutive subjects who underwent screening esophago-gastro-duodenoscopy with serum adiponectin measurement as part of their physical check-up programs were analyzed. Clinical factors were compared between subjects with and without erosive esophagitis. The association between adiponectin and erosive esophagitis was assessed using a bootstrapping re-sampling method after adjustment for factors that tended to be different in univariate analysis.

RESULTS

Serum adiponectin levels were significantly lower in those with erosive esophagitis (8.17 μg/ml) than in those without (10.1). The erosive esophagitis group had a greater body mass index (BMI) and waist circumference (WC) and a higher prevalence of hiatal hernia. Using the bootstrap method, with a lower adiponectin cut-off value of 3-7 μg/ml, the lower limit of the 95% confidence interval of the adjusted odds ratio consistently exceeded 1 after adjustment for BMI and hiatal hernia in men. When adjusting for WC instead of BMI, the effect of adiponectin was reduced but remained significant at a lower cut-off value (3-3.5 μg/ml).

CONCLUSIONS

Low serum adiponectin levels may be associated with an increased risk for erosive esophagitis in men.

Does adiponectin upregulation attenuate the severity of acute pancreatitis in obesity?

INTRODUCTION

Obesity is an independent risk factor for severe acute pancreatitis, though the mechanisms underlying this association are unknown. The powerful anti-inflammatory adipokine adiponectin is decreased in obesity. We recently showed that the severity of pancreatitis in obese mice is inversely related to circulating adiponectin levels, and therefore hypothesized that adiponectin upregulation would attenuate the severity of pancreatitis in obese mice.

METHODS

Forty congenitally obese mice were studied. Seven days prior to study, 20 mice received a single tail vein injection of adenovirus expressing recombinant murine adiponectin (APN; 2 × 10⁸ plaque forming unit (pfu)), and the remainder received a control adenoviral vector expressing β-galactosidase (β-gal; 2 × 10⁸ pfu). Half of the mice in each group had pancreatitis induced by cerulein injection (50 mcg/kg IP hourly for 6 h). The other half received saline on the same schedule. Serum APN concentration and pancreatic tissue concentrations of interleukin (IL)-6, IL-1β, and MCP-1 were measured by ELISA. Histologic pancreatitis score was calculated based on the degree of inflammation (0-4), edema (0-4), and vacuolization (0-4). Data were analyzed by ANOVA and Tukey's tests; p < 0.05 was considered significant.

RESULTS

No difference in body weight was observed between groups. Serum APN was significantly upregulated in the APN group compared with the β-gal group. Pancreatic tissue concentration of IL-6 was significantly decreased in the APN group compared with the β-gal group. No change either in pancreatic tissue concentration of IL-1β and MCP-1 or in the severity of histologic pancreatitis were observed.

CONCLUSION

Adiponectin upregulation modulates the pancreatic cytokine milieu but does not attenuate pancreatitis in this model of mild acute pancreatitis.

Lower serum level of adiponectin is associated with increased risk of endoscopic erosive gastritis

BACKGROUND

Obesity is recently known as a risk factor for endoscopic gastritis. Adiponectin is an anti-inflammatory cytokine secreted from fat tissue, and its serum concentrations are reduced in obesity. The relation between adiponectin and gastritis remains unclear.

AIMS

The aim of this study was to determine whether lower serum adiponectin level is associated with the risk of endoscopic gastritis.

METHODS

We analyzed medical records of participants of a routine health check-up examination. Association among endoscopic findings, serum adiponectin level, and other clinical factors including age, sex, alcohol habit, smoking habit, body mass index (BMI), blood pressure, cholesterol, triglyceride, glucose, and insulin were investigated. Endoscopic erosive gastritis was defined as a flat or minimally depressed white spot surrounded by a reddish area or small elevation with central umbilications mimicking octopus' suckers.

RESULTS

A total of 2,400 participants were enrolled. BMI was significantly higher in gastritis-positive participants than in gastritis-negative participants. Serum adiponectin levels were significantly lower in gastritis-positive participants than in gastritis-negative participants. Multivariate logistic regression analysis revealed that lower serum adiponectin level (OR 0.96; 95% CI 0.93-0.99), smoking (OR 0.50; 95% CI 0.30-0.80), higher blood pressure (OR 1.02; 95% CI 1.01-1.03), and duodenitis (OR 1.8; 95% CI 1.00-3.09) were significantly associated with endoscopic erosive gastritis.

CONCLUSIONS

Lower serum level of adiponectin may increase the risk of endoscopic erosive gastritis, independently of BMI. Our findings facilitate further study to clarify the role of hypoadiponectinemia in erosive gastritis.

Adiponectin deficiency enhanced the severity of cerulein-induced chronic pancreatitis in mice

BACKGROUND

Adiponectin is recognized as an antiinflammatory and antifibrotic protein derived from adipocytes, and low serum adiponectin levels are present in obesity. Recent studies have highlighted the relationship between obesity and pancreatic diseases. However, the role of adiponectin in chronic pancreatitis remains uncertain. The aim of this study was to determine the effects of adiponectin in chronic pancreatitis.

METHODS

We investigated the effects of adiponectin in experimental chronic pancreatitis by using adiponectin-knockout (APN-KO) mice. Chronic pancreatitis was induced by repeated hourly (6 times) intraperitoneal injections of 50 microg/kg cerulein three times per week for 4 weeks in wild-type (WT) and APN-KO mice. We evaluated the severity of chronic pancreatitis biochemically and morphologically.

RESULTS

In cerulein-treated mice, macroscopically and histologically, severe pancreatic damage was observed in APN-KO mice compared with findings in WT mice. The histological scores for chronic pancreatitis, including glandular atrophy, pseudotubular complex, fibrosis, and total scores, were significantly higher in APN-KO mice than in WT mice. Activated pancreatic stellate cells and F4/80-positive pancreatic macrophages accumulated in the pancreas of APN-KO mice but not in WT mice. Overexpression of the mRNAs of transforming growth factor-beta1, CD68, and monocyte chemoattractant protein-1 was noted in APN-KO mice but not in WT mice. The gene expression level of collagen1 (alpha1) tended to be higher in APN-KO mice than in WT mice, albeit insignificantly.

CONCLUSIONS

Adiponectin deficiency enhanced the severity of cerulein-induced chronic pancreatitis in mice. Hypoadiponectinemia could enhance the severity of chronic pancreatitis.

Adipokines and cytokines in human pancreatic juice: unraveling the local pancreatic inflammatory milieu

BACKGROUND

Differential adipokine expression in obesity influences the inflammatory milieu, and may explain in part obesity's negative impact on pancreatic disease. Pancreatic juice analysis may provide a good means to evaluate the local pancreatic inflammatory milieu. The presence of adipokines in pancreatic juice is unknown.

AIMS

This proof-of-concept study was designed to determine the presence of adipokines and cytokines in human pancreatic juice.

METHODS

With institutional review board approval, pancreatic juice was obtained from ten patients with a broad range of diagnoses at the time of endoscopic retrograde cholangiopancreatography. Pancreatic juice was assayed using enzyme-linked immunosorbent assay (ELISA) for insulin, the proinflammatory adipokine leptin, the anti-inflammatory adipokine adiponectin, and the inflammatory mediators interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and monocyte chemoattractant protein-1 (MCP-1). Correlation between adipokine and inflammatory mediator expression was determined by linear regression analysis. Data are presented as mean +/- standard error of the mean (SEM); P < 0.05 was considered statistically significant.

RESULTS

Leptin (0.16 +/- 0.05 ng/ml) and adiponectin (0.63 +/- 0.02 microg/ml) were both present, as were the inflammatory mediators IL-6 (112.6 +/- 28.1 pg/ml), TNF-alpha (49.0 +/- 18.8 pg/ml), and MCP-1 (32.2 +/- 0.9 pg/ml). Paradoxically, the expression of the anti-inflammatory adipokine adiponectin correlated strongly with that of the proinflammatory cytokine IL-6 (R(2) = 0.98, P < 0.001).

CONCLUSIONS

This report is the first to describe adipokine expression in human pancreatic juice. Human pancreatic juice inflammatory mediators and adipokines may provide an important measurement of the local pancreatic inflammatory milieu.

Effect of diet-induced obesity on acute pancreatitis induced by administration of interleukin-12 plus interleukin-18 in mice

Obesity is associated with increased severity of acute pancreatitis (AP). We recently developed a model of AP induced by administration of interleukin (IL)-12+IL-18, two cytokines that are elevated in patients with AP. In this model, severe AP develops in obese leptin-deficient ob/ob mice compared to lean littermates. In the present report, we evaluated the pancreatic response of diet-induced obesity (DIO) mice to IL-12+IL-18. Body weight loss and adipose tissue necrosis were more severe and prolonged in cytokine-injected DIO compared to lean mice. Edematous AP developed in lean mice, whereas DIO mice developed necrotizing AP. Obese DIO mice developed more severe hypocalcemia, increased liver damage and a heightened acute-phase response compared to lean mice, although leukopenia and thrombocytopenia were of comparable severity in lean and DIO mice. Serum levels of IL-6, IL-10, and IL-22 were significantly higher in DIO compared to lean mice, whereas interferon-gamma and tumor necrosis factor-alpha did not differ between the two groups. In conclusion, obesity induced by high-fat diet is associated with increased disease severity and duration in the model of AP induced by administration of IL-12+IL-18.

Biochemical and histological effects of exendin-4 (exenatide) on the rat pancreas

AIMS/HYPOTHESIS

Exendin-4 is a 39 amino acid agonist of the glucagon-like peptide receptor and has been approved for treatment of type 2 diabetes. Many reports describe an increased incidence of acute pancreatitis in humans treated with exendin-4 (exenatide). Previous studies have evaluated the effect of exendin-4 on beta cells and beta cell function. We evaluated the histological and biochemical effects of exendin-4 on the pancreas in rats.

METHODS

We studied 20 Sprague-Dawley male rats, ten of which were treated with exendin-4 and ten of which were used as controls. The study period was 75 days. Serum and pancreatic tissue were removed for biochemical and histological study. Blood glucose, amylase, lipase, insulin and adipocytokines were compared between the two groups.

RESULTS

Animals treated with exendin-4 had more pancreatic acinar inflammation, more pyknotic nuclei and weighed significantly less than control rats. They also had higher serum lipase than control animals. Exendin-4 treatment was associated with lower insulin and leptin levels as well as lower HOMA values than in the untreated control group.

CONCLUSIONS/INTERPRETATION

Although the use of exendin-4 in rats is associated with decreased weight gain, lower insulin resistance and lower leptin levels than in control animals, extended use of exendin-4 in rats leads to pancreatic acinar inflammation and pyknosis. This raises important concerns about the likelihood of inducing acute pancreatitis in humans receiving incretin mimetic therapy.

Experimental evidence of obesity as a risk factor for severe acute pancreatitis

The incidence of acute pancreatitis, an inflammation of the pancreas, is increasing worldwide. Pancreatic injury is mild in 80%-90% of patients who recover without complications. The remaining patients may develop a severe disease with local complications such as acinar cell necrosis, abscess and remote organ injury including lung injury. The early prediction of the severity of the disease is an important goal for physicians in management of patients with acute pancreatitis in order to optimize the therapy and to prevent organ dysfunction and local complications. For that purpose, multiple clinical scale scores have been applied to patients with acute pancreatitis. Recently, a new problem has emerged: the increased severity of the disease in obese patients. However, the mechanisms by which obesity increases the severity of acute pancreatitis are unclear. Several hypotheses have been suggested: (1) obese patients have an increased inflammation within the pancreas; (2) obese patients have an increased accumulation of fat within and around the pancreas where necrosis is often located; (3) increase in both peri- and intra-pancreatic fat and inflammatory cells explain the high incidence of pancreatic inflammation and necrosis in obese patients; (4) hepatic dysfunction associated with obesity might enhance the systemic inflammatory response by altering the detoxification of inflammatory mediators; and (5) ventilation/perfusion mismatch leading to hypoxia associated with a low pancreatic flow might reduce the pancreatic oxygenation and further enhance pancreatic injury. Recent experimental investigations also show an increased mortality and morbidity in obese rodents with acute pancreatitis and the implication of the adipokines leptin and adiponectin. Such models are important to investigate whether the inflammatory response of the disease is enhanced by obesity. It is exciting to speculate that manipulation of the adipokine milieu has the potential to influence the severity of acute pancreatitis.

Substance P, obesity, and gut inflammation

PURPOSE OF REVIEW

The purpose of this review is to present recent data on the effects of substance P on the development of two common pathological conditions, namely obesity and gut inflammation, and elucidate the role of this neuropeptide as a potential regulator between increased adiposity and exacerbated inflammatory responses during inflammatory bowel disease.

RECENT FINDINGS

We present data that demonstrate a role for substance P in both obesity and inflammatory bowel disease and investigate potential effects on fat tissue that may influence the progression of intestinal inflammation. More specifically, we discuss new evidence for direct effects of substance P on fat tissue that determine fat depot size and overall weight in mice and analyze some of the potential mechanisms. Furthermore, we present data that describe changes in the intestinal sensory innervation, in particular substance P-positive innervation, during gut inflammation and new direct evidence of the effects of preestablished obesity in the outcome of experimental inflammation of the colon in mice. In the end we propose a link between the role of substance P in the promotion of obesity and the potential consequences on inflammatory bowel disease.

SUMMARY

We propose that substance P may promote fat tissue expansion either centrally or peripherally and thus create a proinflammatory environment (as is the case with obesity) which may in turn affect the progression (exacerbate) of gut inflammation. Further studies are required on the effects of 'creeping fat' in inflammatory bowel disease in order to decipher the role of this type of fat-depot expansion in the development of the disease.