Effects of gadolinium chloride and glycine on hepatic and pancreatic tissue damage in alcoholic pancreatitis

Associations between genetically predicted levels of blood metabolites and pancreatic cancer risk

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid malignancies, which is featured by systematic metabolism. Thus, a better understanding of metabolic dysregulation in PDAC is important to better characterize its etiology. Here, we performed a large metabolome-wide association study (MWAS) to systematically explore associations between genetically predicted metabolite levels in blood and PDAC risk. Using data from 881 subjects of European descent in the TwinsUK Project, comprehensive genetic models were built to predict serum metabolite levels. These prediction models were applied to the genetic data of 8275 cases and 6723 controls included in the PanScan (I, II and III) and PanC4 consortia. After assessing the metabolite-PDAC risk associations by a slightly modified TWAS/FUSION framework, we identified five metabolites (including two dipeptides) showing significant associations with PDAC risk at false discovery rate (FDR) <0.05. Integrated with gut microbial information, two-sample Mendelian randomization (MR) analyses were further performed to investigate the relationship among serum metabolites, gut microbiome features and PDAC. The flavonoid-degrading bacteria Flavonifractor sp90199495 was found to be associated with metabolite X-21849 and it was also shown to be associated with PDAC risk. Collectively, our study identified novel candidate metabolites for PDAC risk, which could lead to new insights into the etiology of PDAC and improved treatment options.

HMGB1 and Histones Play a Significant Role in Inducing Systemic Inflammation and Multiple Organ Dysfunctions in Severe Acute Pancreatitis

Severe acute pancreatitis (SAP) starts as a local inflammation of pancreatic tissue that induces the development of multiple extrapancreatic organs dysfunction; however, the underlying mechanisms are still not clear. Ischemia-reperfusion, circulating inflammatory cytokines, and possible bile cytokines significantly contribute to gut mucosal injury and intestinal bacterial translocation (BT) during SAP. Circulating HMGB1 level is significantly increased in SAP patients and HMGB1 is an important factor that mediates (at least partly) gut BT during SAP. Gut BT plays a critical role in triggering/inducing systemic inflammation/sepsis in critical illness, and profound systemic inflammatory response syndrome (SIRS) can lead to multiple organ dysfunction syndrome (MODS) during SAP, and systemic inflammation with multiorgan dysfunction is the cause of death in experimental SAP. Therefore, HMGB1 is an important factor that links gut BT and systemic inflammation. Furthermore, HMGB1 significantly contributes to multiple organ injuries. The SAP patients also have significantly increased circulating histones and cell-free DNAs levels, which can reflect the disease severity and contribute to multiple organ injuries in SAP. Hepatic Kupffer cells (KCs) are the predominant source of circulating inflammatory cytokines in SAP, and new evidence indicates that hepatocyte is another important source of circulating HMGB1 in SAP; therefore, treating the liver injury is important in SAP.

The role of glycine in regulated cell death

The cytoprotective effects of glycine against cell death have been recognized for over 28 years. They are expressed in multiple cell types and injury settings that lead to necrosis, but are still not widely appreciated or considered in the conceptualization of cell death pathways. In this paper, we review the available data on the expression of this phenomenon, its relationship to major pathophysiologic pathways that lead to cell death and immunomodulatory effects, the hypothesis that it involves suppression by glycine of the development of a hydrophilic death channel of molecular dimensions in the plasma membrane, and evidence for its impact on disease processes in vivo.

Pretreatment with low-dose gadolinium chloride attenuates myocardial ischemia/reperfusion injury in rats

AIM

We have shown that low-dose gadolinium chloride (GdCl3) abolishes arachidonic acid (AA)-induced increase of cytoplasmic Ca(2+), which is known to play a crucial role in myocardial ischemia/reperfusion (I/R) injury. The present study sought to determine whether low-dose GdCl3 pretreatment protected rat myocardium against I/R injury in vitro and in vivo.

METHODS

Cultured neonatal rat ventricular myocytes (NRVMs) were treated with GdCl3 or nifedipine, followed by exposure to anoxia/reoxygenation (A/R). Cell apoptosis was detected; the levels of related signaling molecules were assessed. SD rats were intravenously injected with GdCl3 or nifedipine. Thirty min after the administration the rats were subjected to LAD coronary artery ligation followed by reperfusion. Infarction size, the release of serum myocardial injury markers and AA were measured; cell apoptosis and related molecules were assessed.

RESULTS

In A/R-treated NRVMs, pretreatment with GdCl3 (2.5, 5, 10 μmol/L) dose-dependently inhibited caspase-3 activation, death receptor-related molecules DR5/Fas/FADD/caspase-8 expression, cytochrome c release, AA release and sustained cytoplasmic Ca(2+) increases induced by exogenous AA. In I/R-treated rats, pre-administration of GdCl3 (10 mg/kg) significantly reduced the infarct size, and the serum levels of CK-MB, cardiac troponin-I, LDH and AA. Pre-administration of GdCl3 also significantly decreased the number of apoptotic cells, caspase-3 activity, death receptor-related molecules (DR5/Fas/FADD) expression and cytochrome c release in heart tissues. The positive control drug nifedipine produced comparable cardioprotective effects in vitro and in vivo.

CONCLUSION

Pretreatment with low-dose GdCl3 significantly attenuates I/R-induced myocardial apoptosis in rats by suppressing activation of both death receptor and mitochondria-mediated pathways.

PANCREATITIS OR NOT?--Elevated lipase and amylase in ICU patients

Elevation in serum levels of pancreatic enzymes (Hyperamylasemia and/or Hyperlipasemia) can occur in any Intensive Care Unit (ICU) patient either as a result of true acute pancreatitis (AP) or as a reflection of a non-pancreatic disease. Although most patients may not have clinical pancreatitis, identifying true acute pancreatitis in the ICU setting may be critical in the presence of associated co-morbid conditions of the disease for which the patient is being managed. With neither amylase nor lipase being specific for pancreatitis, it is important for the clinician to be aware of different causes of hyperamylasemia and hyperlipasemia, especially when clinical diagnosis of pancreatitis is unclear. This review will focus on understanding different non-pancreatic conditions where there is elevation of pancreatitis enzymes and to identify true acute pancreatitis in critically ill patients without typical symptoms.

Radioprotective effect of kupffer cell depletion on hepatic sinusoidal endothelial cells

Radiation-induced liver injury remains a clinical problem and data suggest that sinusoidal endothelial cells (SECs) are an important target. The purpose of this study was to determine whether the inhibition of Kupffer cells before exposure would protect SECs from radiation-induced injury. Sprague-Dawley rats were intravenously injected 24 h before irradiation with Kupffer cell inhibitor gadolinium chloride (GdCl3) (10 mg/kg body weight). Three groups of animals were treated: 1. control group (saline and sham irradiation); 2. GdCl3 + 30 Gy radiation group and 3. 30 Gy radiation only group. Specimens were collected at 2, 6, 12, 24 and 48 h after completion of each treatment. Liver tissue was assessed for inflammatory cytokine expression and radiation-induced SEC injury based on serum hyaluronic acid (HA) level, apoptosis and ultrastructural and histological analyses. The results showed that radiation exposure caused apoptosis of SECs, but not hepatocytes. Inflammatory cytokine expression, including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) expression, was significantly attenuated in the GdCl3 + 30 Gy radiation group, compared with the 30 Gy radiation-only group (P < 0.05). The GdCl3 + radiation-treated rats exhibited significantly lower levels of HA and SEC apoptosis than the radiation-treated only rats at early time points, and radiation-induced liver injury was also attenuated. In conclusion, we hypothesize that selective Kupffer cell inhibition by gadolinium chloride was shown to reduce apoptosis in SECs caused by irradiation of the live and protected the liver against radiation-induced injury.

Inflammatory profiling of early experimental necrotizing pancreatitis

AIMS

Inflammatory mediators play a pivotal role in severe necrotizing pancreatitis (SNP). Therapeutic approaches aim at the early inflammatory liberation of cytokines to avoid systemic complications. The present study evaluates the kinetics of inflammatory mediator release in SNP.

MAIN METHODS

Experimental SNP was induced in male Wistar rats using the GDOC model. The animals were allocated into seven groups (n = 6/group). In group 1, sample harvesting was performed after sham operation while in groups 2-7 this was performed 1 h, 2 h, 4 h, 6 h, 9 h, and 12 h after initiation of SNP, respectively. Inflammatory mediator release,morphologic injury, and tissue MPO concentrations were evaluated between 1 and 12 h after induction.

KEY FINDINGS

Pancreatic injury showed a continuous increase over the observation period (p b 0.05, respectively). MPO levels in the pancreas and lungs increased until 12 h after induction (p b 0.05, respectively). Antiinflammatory IL-10 showed an early peak and the pro-inflammatory mediators TNFα and IL-1β peaked after 6 and 9 h, respectively (p b 0.05, respectively). HMGB1 levels constantly increased over time (p b 0.05, respectively).

SIGNIFICANCE

The present study shows the release of relevant pro- and anti-inflammatory mediators in SNP for the first time in one single experimental setup. Inflammatory mediators peak within the first few hours after SNP induction. Consequently, the effect of therapeutic approaches on early changes in cytokine release should be evaluated later than 2 h after initiation.

Pharmacological cholinergic stimulation as a therapeutic tool in experimental necrotizing pancreatitis

OBJECTIVES

The endogenous immune response is influenced by the stimulation of the vagal nerve. Stimulation or ablation has a direct impact on the release of pro- and anti-inflammatory mediators. In the progression of acute pancreatitis from local to systemic disease, these mediators play a pivotal role. This study evaluates the effect of pharmacologic stimulation of the cholinergic system on pancreatic damage in experimental necrotizing pancreatitis.

METHODS

Experimental severe necrotizing pancreatitis was induced in male Wistar rats using the glycodeoxycholic acid model. Animals with acute pancreatitis (n = 6) were compared with animals with acute pancreatitis and prophylactic or therapeutic pharmacologic activation of the cholinergic system using nicotine, physostigmine, or neostigmine (n = 36). Twelve hours after the induction of acute pancreatitis, morphological damage as well as the myeloperoxidase levels of the pancreas and the serum levels of high-mobility group box 1 protein were evaluated.

RESULTS

Prophylactic and delayed therapeutic application of nicotine, physostigmine, or neostigmine significantly attenuated the severity of acute pancreatitis 12 hours after the induction of severe necrotizing pancreatitis compared with untreated controls as evaluated with histological scores, myeloperoxidase, and high-mobility group box 1 levels (P < 0.05).

CONCLUSIONS

Stimulation of the cholinergic system is useful to attenuate damage in experimental acute pancreatitis. Not only prophylactic but also delayed application was effective in the present study.

Da-Huang-Fu-Zi-Tang attenuates liver injury in rats with severe acute pancreatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Da-Huang-Fu-Zi-Tang (DHFZT) is a famous traditional Chinese prescription with strong anti-inflammatory effects. Our previous work found that DHFZT could act against pancreatic injury in rats with severe acute pancreatitis (SAP) via inhibiting the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) signaling pathway in pancreatic tissues.

AIM OF THE STUDY

To investigate the therapeutic effects of DHFZT on liver injury in SAP rats, and the effects on JAK2/STAT3 signaling in liver tissue and Kupffer cells (KCs).

MATERIALS AND METHODS

Fifty SD male rats were randomly divided into five groups: sham operation group (SO), SAP model group, DHFZT treatment groups (12, 24, and 48 mg/kg body weight). The model of SAP was constructed by injecting sodium taurocholate (3.5%) into pancreatic and biliary ducts. One hour before constructing the model, DHFZT was perfused into the stomach. All rats were sacrificed after 24h following the operation; livers were examined with hematoxylin and eosin staining. The protein expression of pJAK2 and pSTAT3 in liver tissue was detected by immunohistochemical staining. The activity of ALT, IL-6 and TNF-α in serum was detected. KCs of each group were isolated. After culture for 4h, the protein expression of JAK2, pJAK2, STAT3 and pSTAT3, the mRNA expression of IL-6 and TNF-α in KCs were examined.

RESULTS

Sodium taurocholate induced liver injury concomitant with increased expression of pJAK2 and pSTAT3 in liver tissue and KCs. Pretreatment with DHFZT significantly attenuated liver injury induced by SAP, and concurrently, effectively lowered the serum ALT level. Furthermore, our studies showed that DHFZT obviously decreased the expression of pJAK2 and pSTAT3 in liver tissue and KCs.

CONCLUSIONS

DHFZT could ameliorate liver injury in rats with SAP.

Necro-inflammatory response of pancreatic acinar cells in the pathogenesis of acute alcoholic pancreatitis

The role of pancreatic acinar cells in initiating necro-inflammatory responses during the early onset of alcoholic acute pancreatitis (AP) has not been fully evaluated. We investigated the ability of acinar cells to generate pro- and anti-inflammatory mediators, including inflammasome-associated IL-18/caspase-1, and evaluated acinar cell necrosis in an animal model of AP and human samples. Rats were fed either an ethanol-containing or control diet for 14 weeks and killed 3 or 24 h after a single lipopolysaccharide (LPS) injection. Inflammasome components and necro-inflammation were evaluated in acinar cells by immunofluorescence (IF), histology, and biochemical approaches. Alcohol exposure enhanced acinar cell-specific production of TNFα, IL-6, MCP-1 and IL-10, as early as 3 h after LPS, whereas IL-18 and caspase-1 were evident 24 h later. Alcohol enhanced LPS-induced TNFα expression, whereas blockade of LPS signaling diminished TNFα production in vitro, indicating that the response of pancreatic acinar cells to LPS is similar to that of immune cells. Similar results were observed from acinar cells in samples from patients with acute/recurrent pancreatitis. Although morphologic examination of sub-clinical AP showed no visible signs of necrosis, early loss of pancreatic HMGB1 and increased systemic levels of HMGB1 and LDH were observed, indicating that this strong systemic inflammatory response is associated with little pancreatic necrosis. These results suggest that TLR-4-positive acinar cells respond to LPS by activating the inflammasome and producing pro- and anti-inflammatory mediators during the development of mild, sub-clinical AP, and that these effects are exacerbated by alcohol injury.

Protective effect of gadolinium chloride on early warm ischemia/reperfusion injury in rat bile duct during liver transplantation

Background

Activation of Kupffer cell (KC) is acknowledged as a key event in the initiation and perpetuation of bile duct warm ischemia/reperfusion injury. The inhibitory effect of gadolinium chloride (GdCl₃) on KC activation shows potential as a protective intervention in liver injury, but there is less research with regard to bile duct injury.

Methods

Sixty-five male Sprague-Dawley rats (200–250 g) were randomly divided into three experimental groups: a sham group (n = 15), a control group (n = 25), and a GdCl₃ group (n = 25). Specimen was collected at 0.5, 2, 6, 12 and 24 h after operation. Alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TBIL) of serum were measured. Tumor necrosis factor-α (TNF-α), Capase-3 activity and soluble Fas (sFas) were detected. The pathologic changes of bile duct were observed. Immunochemistry for bile duct Fas was performed. Apoptosis of bile duct cells was evaluated by the terminal UDP nick end labeling assay.

Results

GdCl₃ significantly decreased the levels of ALT, ALP and TBIL at 2, 6, 12, and 24 h, and increased serum sFas at 2, 6 and 12 h (P<0.05). TNF-α was lower in the GdCl₃ group than in the control group at 2, 6, 12 and 24 h (P<0.05). Preadministration of GdCl₃ significantly reduced the Caspase-3 activity and bile duct cell apoptosis at 2, 6, 12 and 24 h. After operation for 2, 6 and 12 h, the expression of Fas protein was lower in the GdCl₃ group than in the control group (P<0.05).

Conclusions

GdCl₃ plays an important role in suppressing bile duct cell apoptosis, including decreasing ALT, ALP, TBIL and TNF-α; suppressing Fas-FasL-Caspase signal transduction during transplantation.

Wu-Chia-Pi solution attenuates carbon tetrachloride-induced hepatic injury through the antioxidative abilities of its components acteoside and quercetin

Wu-Chia-Pi medicated wine, composed nine Chinese medicines soaked in 35% alcohol, is widely used in Asia for its health-promoting functions. However, long-term consumption of alcohol could result in liver dysfunction. In this study, Wu-Chia-Pi solution (WCPS) and extract (WCPE) were prepared by modification of the principals given by the Committee on Chinese Medicine and Pharmacy in Taiwan. The aim of this study was to explore the protective effect of WCPS against carbon tetrachloride (CCl₄)-induced liver injury and to clarify its active component(s). Antioxidative effects of the test samples were evaluated via MDA inhibition, catalase activity and DPPH-scavenging assays. HPLC was used to analysis the active components. Results showed that WCPS (1 and 5 mL/kg) significantly prevented CCl₄-induced liver injury without chronic liver toxicity. Referring to the antioxidative activities, WCPE displayed significant MDA inhibitory and DPPH-scavenging activities with IC₅₀ values of 0.91 ± 0.03 and 0.60 ± 0.04 mg/mL, respectively. Catalase activity was also enhanced by treatment of WCPE, acteoside and quercetin. Therefore, we suggest that acteoside and quercetin are the major contributors to the antioxidative and hepatoprotective activities of WCPS, and a possible mechanism could be mediated through reduction of oxidative stress.

Taurine attenuates liver injury by downregulating phosphorylated p38 MAPK of Kupffer cells in rats with severe acute pancreatitis

This study was undertaken to clarify the effects of taurine on liver injury in rats with severe acute pancreatitis (SAP). Rats were randomly assigned to three groups: a sham operation (SO), a SAP (established by infusion of 5% taurocholate), and a SAP given taurine (Taur). At 12 and 24 h post-operation, taurine pretreatment significantly attenuated hepatic tissue injury induced by SAP, and concurrently, serum alanine aminotransferase, aspartate transaminase, and amylase levels were significantly reduced by taurine pretreatment. Compared with the SO group, the total and phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) expression and nuclear factor-κB (NF-κB) activity of Kupffer cells (KCs) were significantly higher in the SAP group, but taurine pretreatment inhibited the total and phosphorylated p38 MAPK expression and NF-κB activity of KCs in the SAP group. The increase of tumor necrosis factor-α and interleukin-lβ in cultured supernate of the SAP rat-derived KCs was also significantly inhibited by taurine pretreatment. These results suggest that taurine pretreatment ameliorated liver injury in rats with SAP mainly by inhibiting phosphorylated p38 MAPK and NF-κB activity in KCs, which may play an important role in liver injury.

Therapeutic treatment with ethyl pyruvate attenuates the severity of liver injury in rats with severe acute pancreatitis

OBJECTIVE

The objective of the study was to evaluate the effect of ethyl pyruvate (EP) in ameliorating liver injury in rats with severe acute pancreatitis (SAP) and its possible mechanism.

METHODS

Rats were randomly divided into control group, SAP group, and EP-treated group. Then, the tissue specimens were harvested for morphological studies, immunohistochemistry examination, reverse transcriptase-polymerase chain reaction, and Western blot analysis. The DNA-binding activity of nuclear factor κB was measured by electrophoretic mobility shift assay. The concentrations of serum amylase, alanine aminotransferase, and pancreatic tissue malondialdehyde and the activity of myeloperoxidase in the liver were determined.

RESULTS

Treatment with EP after SAP was associated with a reduction in the severity of SAP and liver injury. Treatment with EP significantly decreased the hepatic mRNA expression of tumor necrosis factor α and interleukin 1β and ameliorated the activity of myeloperoxidase in the liver in SAP rats. Compared with the SAP group, treatment with EP significantly decreased the infiltration of inflammatory cells and markedly inhibited hepatic nuclear factor κB DNA binding; EP therapy dramatically inhibited high-mobility group box 1 expression from inflamed hepatic tissue.

CONCLUSIONS

Our results demonstrate that EP might play a therapeutic role in liver inflammation in this SAP model, and these beneficial effects of EP are because of the modulation of high-mobility group box 1 and other inflammatory cytokine responses.

Alcoholic acute pancreatitis: pathogenesis and clinical characteristics

Animal and clinical studies have shown that alcohol and its metabolic products, endotoxin, viral infection, drinking pattern, smoking, obesity, genetic variability, and gene polymorphisms were very important in the pathogenesis of alcoholic acute pancreatitis (AAP). The morbidity of AAP has been increased in the past decade, and male gender is strongly associated with increased risk of AAP. The mortality of AAP is high, while the quality of life of survivors of severe AAP is low. In this paper, we review the pathogenesis and clinical characteristics of AAP.