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

Liver injury associated with acute pancreatitis: The current status of clinical evaluation and involved mechanisms

Acute pancreatitis (AP) is a very common acute disease, and the mortality rate of severe AP (SAP) is between 15% and 35%. The main causes of death are multiple organ dysfunction syndrome and infections. The mortality rate of patients with SAP related to liver failure is as high as 83%, and approximately 5% of the SAP patients have fulminant liver failure. Liver function is closely related to the progression and prognosis of AP. In this review, we aim to elaborate on the clinical manifestations and mechanism of liver injury in patients with AP.

Effects of propofol on inflammatory response and activation of p38 MAPK signaling pathway in rats with ventilator-induced lung injury

Purpose:

To investigate the effects of propofol on inflammatory response and activation of p38 mitogen-activated protein kinase (MAPK) signaling pathway in rats with ventilator-associated lung injury (VALI).

Methods:

Thirty-six Sprague Dawley (SD) rats were divided into control, VALI and VALI+propofol groups. The VALI group received the mechanical ventilation for 2 h. The VALI+propofol group received the mechanical ventilation for 2 h, which was accompanied by intravenous injection of propofol with dose of 8 mg·kg^-1·h^-1. At the end, the mean arterial pressure (MAP) and blood gas indexes were measured, and the lung wet/dry mass ratio (W/D) and biochemical indexes of lung tissue and bronchoalveolar lavage fluid (BALF) were determined.

Results:

Compared with VALI group, in VALI+propofol group the blood pH, partial pressure of oxygen, partial pressure of carbon dioxide and MAP were increased, the lung W/D, lung tissue myeloperoxidase activity and total protein concentration, white blood cell count, and tumor necrosis factor α, interleukin 1β and interleukin 6 levels in BALF were decreased, and the p-p38 MAPK protein expression level and phosphorylated p38 MAPK (p-p38 MAPK)/p38 MAPK ratio were decreased.

Conclusions:

Propofol treatment may alleviate the VALI in rats by reducing the inflammatory response and inhibiting the activation of p38 MAPK signaling pathway.

Progress in research of liver injury induced by acute biliary pancreatitis

Acute biliary pancreatitis (ABP) not only causes acute inflammation of the pancreas, but also leads to obstruction or infection of the biliary system. Liver injury is one of the most common complications of ABP. The pathological mechanisms mainly include infection and endotoxin, cholestasis, pancreatic enzyme damage, microcirculatory disorders, and oxidative stress, and the research conclusions are mostly derived from animal experiments. On the basis of routine medical treatment of ABP, active anti-infective treatment and rapid relief of biliary obstruction can promote the recovery of ABP-related liver injury.

Protective Effects of Calcitonin Gene-Related Peptide-Mediated p38 Mitogen-Activated Protein Kinase Pathway on Severe Acute Pancreatitis in Rats

BACKGROUND

Calcitonin gene-related peptide (CGRP) has antioxidant and anti-inflammatory activities on the pathological damage of acute pancreatitis. However, its molecular mechanism on severe acute pancreatitis (SAP) remains unknown.

AIMS

To evaluate the influence of CGRP-mediated p38MAPK signaling pathway in rats with SAP.

METHODS

SD rats were randomly divided into Sham group, SAP group, CGRP group (SAP rats injected with CGRP), SB203580 group (rats injected with p38MAPK pathway inhibitor SB203580), and CGRP8-37 group (SAP rats injected with CGRP8-37). Serum amylase and lipase activities were determined. Histopathological observations were evaluated, and the expression of inflammatory cytokines and oxidative stress-related indexes were measured.

RESULTS

Compared with Sham group, SAP rats were increased in the activities of serum amylase and lipase, the pathologic assessment of pancreatic tissue, the levels of TNF-α, IL-1β, IL-6, and IL-8, the content of MDA and MPO, and the expressions of CGRP, and p-p38MAPK protein, but they were decreased in SOD activity and GSH content. The above alterations were aggravated in the CGRP8-37 group when compared with SAP group. Besides, in comparison with SAP group, rats in the CGRP and SB203580 groups presented a reduction in the activities of serum amylase and lipase, the levels of inflammatory cytokines, the content of MDA and MPO, and the expressions of p-p38MAPK protein, while showed an elevation in SOD activity and GSH content.

CONCLUSION

Pretreatment with CGRP alleviated oxidative stress and inflammatory response of SAP rats possibly by suppressing the activity of p38MAPK pathway, and thereby postponing the disease progression.

Melatonin attenuated inflammatory reaction by inhibiting the activation of p38 and NF‑κB in taurocholate‑induced acute pancreatitis

The aim of the present study was to investigate the protective mechanism underlying of melatonin in severe acute pancreatitis (SAP). A total of 64 male Sprague‑Dawley rats were randomly divided into four groups: The sham operation (SO) group, SAP group, melatonin treatment (MLT) group and p38 inhibitor (SB203580) treatment (SB) group. Acute pancreatitis was induced by 5% taurocholate through retrograde infusion into the biliopancreatic ducts. The melatonin and SB203580 treatment groups were administered with MLT and SB 30 min before operation the induction of SAP. Rats in each group were euthanized at 6 and 12 h following SAP induction. Blood and pancreatic tissues were removed for inflammatory examination. Peripheral blood mononuclear cells (PBMCs) were isolated following sacrifice to measure the phosphorylation of p38 and nuclear factor‑κB (NF‑κB was measured as p65 and phosphorylation of p65). The pretreatment of melatonin significantly attenuated the severity of pancreatitis. In addition, melatonin also reduced serum amylase and proinflammatory cytokine levels, including tumor necrosis factor‑α, interleukin (IL)‑1 and IL‑6. The mean pathological scores for pancreatic tissues in the MLT group were higher than those for samples in the SO group, but were lower than those for samples in the SAP group at each time-point. Phosphorylation of p38 and p65 levels in the melatonin treatment group were lower than that in the SAP group, and higher in the SAP group than in the SO group, and the SB203580 treatment group. Furthermore, melatonin significantly inhibited the activation of p38 and NF‑κB in PBMCs. The authors revealed that melatonin may attenuate inflammatory reactions by inhibiting the activation of p38 MAPK and NF‑κB in both acute pancreatitis rats and PBMCs. SAP is a severe disease with a high risk of morbidity and mortality. It is important to attenuated inflammatory reaction in acute pancreatitis. Thus, the authors studied melatonin, which is synthesized by the pineal gland and released into the blood. Previous studies have shown that melatonin serves a protective role in the early course of human acute pancreatitis, and melatonin concentration variations are closely related to the severity of acute pancreatitis. It may be concluded that melatonin may attenuates inflammatory reactions by inhibiting the activation of p38 MAPK and NF‑κB in both acute pancreatitis rats and PBMCs.

Involvement of the PI3K/Akt/NF-κB Signaling Pathway in the Attenuation of Severe Acute Pancreatitis-Associated Acute Lung Injury by Sedum sarmentosum Bunge Extract

Sedum sarmentosum Bunge possesses excellent anti-inflammatory properties and was used in the treatment of inflammatory diseases. The aim of the present study was to investigate the efficiency of Sedum sarmentosum Bunge extract (SSBE) on severe acute pancreatitis-associated (SAP-associated) acute lung injury (ALI) in rats and to explore the underlying mechanisms. Here, we used a sodium taurocholate-induced SAP rat model to determine the role of SSBE in ALI. During the course of pancreatitis, the expressions of phosphorylated phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt) and nuclear factor-kappa B (NF-κB) p65 in the lungs were upregulated. Meanwhile, a parallel increase in the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the lungs was observed after the induction of SAP. Treatment with SSBE significantly reduced the expression of p-Akt and p-p65 in the lungs and attenuated the severity of SAP-associated ALI compared to the SAP group at 12 h and 24 h. In summary, this study showed that SSBE has beneficial effects on SAP-associated ALI, probably through the PI3-K/Akt signaling pathways by suppressing the NF-κB activities.

Hepatoprotective activities of Antrodia camphorata and its triterpenoid compounds against CCl4-induced liver injury in mice

ETHNOPHARMACOLOGY RELEVANCE

Antrodia camphorata (AC) is a rare and precious fungus indigenous to Taiwan used as a traditional medicine for the treatment of liver injury. Triterpenoids are the major bioactive constituents of A. camphorata and have been reported to possess hepatoprotective activities. To meet the increasing demand, artificial cultivation techniques have been developed.

AIM OF THE STUDY

This study aims to evaluate the hepatoprotective activities of AC samples derived from different cultivation techniques and to dissect the main active triterpenoid compounds.

MATERIALS AND METHODS

The ethanol extracts of five batches of AC samples, including wild growing fruiting bodies, cutting wood culture fruiting bodies, dish cultures, cutting wood culture mycelia, and submerged fermentation mycelia were orally administered (50mg/kg or 200mg/kg) to ICR mice for 7 days. On the last day, CCl₄ (0.2%, 7mL/kg, i.p.) was used to induce liver injury, and the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined 24h after the injection. Moreover, a HepG2 cell model treated with CCl₄ (0.35%) was used to screen the protective activities of 29 AC triterpenoids. After incubation for 6h, viabilities of the cells were tested using MTS assay. The in vivo hepatoprotective activities of antcin B and antcin K were further studied on the mice model by ALT and AST tests and histopathologic examinations. To elucidate the mechanisms, the mRNA levels of iNOS, COX2, TNF-α and IL-1β, and the protein levels of NF-κB (p65/p-p65), iNOS and COX2 in liver tissues were determined.

RESULTS

The wild growing or cutting wood culture fruiting bodies, and the dish cultures of AC showed more potent activities than the mycelia (P<0.001). At 20μM, 16 of 29 triterpenoids showed significant protective activities, increasing HepG2 cell viability from 46% of the CCl₄ group to >90%. Antcin B and antcin K could dose-dependently (10 or 50mg/kg, 7 days, i.g.) decrease the serum levels of ALT and AST, and decrease the incidence of liver necrosis. The effects of 50mg/kg of antcin K or antcin B were almost identical to those of 100mg/kg silymarin. Furthermore, qRT-PCR and Western blotting analyses revealed they could down-regulate IL-1β, TNF-α, iNOS, COX-2 and NF-κB in liver tissues at both transcriptional and translational levels.

CONCLUSION

The results indicate that cultivation techniques remarkably affect the hepatoprotective activities of AC. Antcin K and antcin B are the major hepatoprotective compounds of A. camphorata, and the mechanism is related with anti-inflammation. Given its high natural abundance and good oral absorption, antcin K could be a promising drug candidate for liver injury.

Hydrogen-Rich Saline Attenuates Acute Hepatic Injury in Acute Necrotizing Pancreatitis by Inhibiting Inflammation and Apoptosis, Involving JNK and p38 Mitogen-Activated Protein Kinase-dependent Reactive Oxygen Species

OBJECTIVES

The objective of this study was to study the role of hydrogen-rich saline (HRS) on acute hepatic injury (AHI) in acute necrotizing pancreatitis (ANP).

METHODS

Rats were used for this study and an ANP model was induced by injecting 5% sodium taurocholate into the biliary-pancreatic duct. Experiments were performed in 3 groups: sham, ANP, and ANP + HRS (HRS). Animals were killed at 3, 12, and 24 hours after operation, and then blood and tissue samples were harvested. Various physiological, histological, and cellular and molecular parameters were analyzed.

RESULTS

Analyses of serum, lipase, alanine transaminase, and aspartate aminotransferase indicated that ANP-induced AHI model was established successfully and HRS attenuated hepatic dysfunction. Hepatic superoxide dismutase and malondialdehyde levels showed HRS against oxidative stress. Cellular and molecular analyses including p-p38, p-JNK, p-ERK, and caspase-3, caspase-9, NF-κB, and TNF-α in hepatic tissues revealed that HRS attenuated ANP-induced AHI by inhibiting apoptosis and phosphorylation of JNK and p38, as well as NF-κB activation.

CONCLUSIONS

Hydrogen-rich saline plays a protective role in ANP-induced AHI through inhibiting inflammation and apoptosis, involving JNK and p38 MAPK-dependent reactive oxygen species.

Hydrolyzed fish proteins modulates both inflammatory and antioxidant gene expression as well as protein expression in a co culture model of liver and head kidney cells isolated from Atlantic salmon (Salmo salar)

Hydrolyzed fish proteins (H-pro) contain high concentrations of free amino acids and low molecular peptides that potentially may benefit fish health. The following study aimed to test whether the water-soluble phase of H-pro could attenuate lipopolysaccharide (LPS) provoked inflammation in liver cells and head kidney cells isolated from Atlantic salmon. Cells were grown as mono cultures or co cultures to assess possible crosstalk between immune cells and metabolic cells during treatments. Cells were added media with or without H-pro for 2 days before LPS exposure and harvested 24 h post LPS exposure. Respective cells without H-pro and LPS were used as controls. H-pro alone could affect expression of proteins directly as H-pro increased catalase protein expression in head kidney- and liver cells, regardless of culturing methods and LPS treatment. Leukotriene B4 (LTB4) production was also increased by H-pro in head kidney cells co cultured with liver cells. H-pro increased LPS induced interleukin 1β (IL-1β) transcription in liver cells co cultured with head kidney cells. All cultures of head kidney cells showed a significant increase in IL-1β transcription when treated with H-pro + LPS. H-pro decreased caspase-3 transcription in liver cells cultured co cultured with head kidney cells. Peroxisome proliferator activated receptor α (PPAR α) was upregulated, regardless of treatment, in liver cells co cultured with head kidney cells clearly showing that culturing method alone affected gene transcription. H-pro alone and together with LPS as an inflammation inducer, affect both antioxidant and inflammatory responses.

Assessment of resveratrol, apocynin and taurine on mechanical-metabolic uncoupling and oxidative stress in a mouse model of duchenne muscular dystrophy: A comparison with the gold standard, α-methyl prednisolone

Antioxidants have a great potential as adjuvant therapeutics in patients with Duchenne muscular dystrophy, although systematic comparisons at pre-clinical level are limited. The present study is a head-to-head assessment, in the exercised mdx mouse model of DMD, of natural compounds, resveratrol and apocynin, and of the amino acid taurine, in comparison with the gold standard α-methyl prednisolone (PDN). The rationale was to target the overproduction of reactive oxygen species (ROS) via disease-related pathways that are worsened by mechanical-metabolic impairment such as inflammation and over-activity of NADPH oxidase (NOX) (taurine and apocynin, respectively) or the failing ROS detoxification mechanisms via sirtuin-1 (SIRT1)-peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) (resveratrol). Resveratrol (100mg/kg i.p. 5days/week), apocynin (38mg/kg/day per os), taurine (1g/kg/day per os), and PDN (1mg/kg i.p., 5days/week) were administered for 4-5 weeks to mdx mice in parallel with a standard protocol of treadmill exercise and the outcome was evaluated with a multidisciplinary approach in vivo and ex vivo on pathology-related end-points and biomarkers of oxidative stress. Resveratrol≥taurine>apocynin enhanced in vivo mouse force similarly to PDN. All the compounds reduced the production of superoxide anion, assessed by dihydroethidium staining, with apocynin being as effective as PDN, and ameliorated electrophysiological biomarkers of oxidative stress. Resveratrol also significantly reduced plasma levels of creatine kinase and lactate dehydrogenase. Force of isolated muscles was little ameliorated. However, the three compounds improved histopathology of gastrocnemius muscle more than PDN. Taurine>apocynin>PDN significantly decreased activated NF-kB positive myofibers. Thus, compounds targeting NOX-ROS or SIRT1/PGC-1α pathways differently modulate clinically relevant DMD-related endpoints according to their mechanism of action. With the caution needed in translational research, the results show that the parallel assessment can help the identification of best adjuvant therapies.

Hydrolyzed fish proteins reduced activation of caspase-3 in H2O2 induced oxidative stressed liver cells isolated from Atlantic salmon (Salmo salar)

Hydrolyzed fish proteins (H-pro) contains high concentrations of free amino acids and low molecular peptides that potentially benefit health. The following study aimed to test whether the water soluble phase of H-pro could reduce apoptosis and inflammation in primary liver cells isolated from Atlantic salmon following H₂O₂ provoked oxidative stress. Cells were grown as monocultures or co-cultured with head kidney cells to assess possible cross talk in inflammation and metabolism during treatments. Cells were grown in media with or without H-pro for 2 days before being stressed with 200 µM H₂O₂ then harvested 24 h post exposure. Both treatments were compared to the respective treatments without H₂O₂ supplementation. Oxidative stressed cells had increased activation of caspase-3, but supplementation with H-pro in the media prior to the oxidative stress reduced caspase-3 activation. In conclusion, free amino acids and low molecular weight peptides from H-pro attenuated oxidative stress, and made cells able to withstand apoptosis after H₂O₂ provoked oxidative stress.

Role of Kupffer cells in bacterial infectious diseases

Kupffer cells (KCs) are also known as liver inherent macrophages, which account for the largest part of human tissue macrophages and participate in the pathogenesis of various liver diseases. In vitro study using primary culture is a valuable tool for the exploration of specific immunological functions of KCs. Obtaining KCs with high purity and activity is the basis for research. A large number of phagocytosable particles and soluble substances can activate KCs by binding to specific receptors on the membrane. The most important molecule that activates KCs is lipopolysaccharide (LPS). A tiny quantity of LPS will drive a Toll-like receptor 4 (TLR4) -dependent proinflammatory response that alerts the host to the presence of infection. Higher quantities of LPS, which reach the cytoplasm, will trigger inflammasome activation, interleukin-1 beta (IL-1β) production and, ultimately, cell death. KCs play an important role in sepsis, endotoxin tolerance and acute pancreatitis. In this review, we describe the role of KCs in these diseases and the underlying molecular mechanisms.

Role of Kinase Epidermal Growth Factor Receptor and SRC in the Caerulein-Induced Acute Pancreatitis in Mice

OBJECTIVES

In this study, we identified the protein kinases that play the most distinct roles in the occurrence of acute pancreatitis (AP).

METHODS

Gene expression profile data were downloaded from Gene Expression Omnibus database (GSE3644). The sample was from caerulein-induced AP mice. The intersection of the differentially expressed genes in AP mice taken from a protein kinase database was obtained for screening of the protein kinase encoded genes that were differentially expressed. Database for annotation, visualization, and integrated discovery was used for the functional enrichment analysis. Kinase inhibitors that regulated these kinases were retrieved from PubMed through text mining.

RESULTS

Twenty-nine differentially expressed kinase encoded genes were identified through screening. The functional enrichment analysis demonstrated that the functions of these genes were primarily enriched in "mitogen-activated protein kinase signaling pathway," followed by "extracellular regulated protein kinases pathway," "neurotrophin signaling pathway," "adherens junction," and "gap junction." SRC and epidermal growth factor receptor (EGFR) were related to extracellular regulated protein kinases pathway and also related to adherens junction as well as gap junction. On the basis of the regulated kinases, the kinase inhibitors reported in the literature were classified into multiple groups.

CONCLUSIONS

EGFR and SRC may be coexpressed in AP. The kinase inhibitors working together in SRC and EGFR may play better efficacy in the treatment of AP.

The effects of Twist-2 on liver endotoxin tolerance induced by a low dose of lipopolysaccharide

Endotoxin tolerance is an important mechanism for preventing uncontrolled inflammatory cytokine production in bacterial sepsis. However, its molecular mechanisms remain largely unknown. It was reported that Twist-2 protein was a negative regulator for cytokine signaling by repressing the nuclear factor (NF)-κB-dependent cytokine pathway. However, the relationship between Twist-2 and endotoxin tolerance is unclear. Endotoxin tolerance models of BABL/c mice and isolated Kupffer cells (KCs) were established to observe the changes of Twist-2 during endotoxin tolerance. Then, Twist-2 shRNA was used to specifically inhibit Twist-2 gene in KCs to further explore the role of Twist-2 in endotoxin tolerance. The expression of Twist-2 was analyzed by immunohistochemistry, reverse transcription polymerase chain reaction, and Western blotting, respectively. The responses to lipopolysaccharide were assessed by the activation of nuclear factor-κB and the production of tumor necrosis factor-α. The histopathologic changes in the liver of the non-endotoxin tolerance group were more serious than those of the endotoxin tolerance group. Endotoxin tolerance also led to less activation of nuclear factor-κB, lower expression levels of tumor necrosis factor-α mRNA, and more expression of Twist-2 than those of non-endotoxin tolerance group in liver and KCs. Moreover, the inhibitive effects partly weaken in KCs transfected with Twist-2 shRNA. Twist-2 was involved in endotoxin tolerance through inhibiting NF-κB trans-activation and cytokines transcriptional activities. It may be a new target for the clinical treatment of sepsis and other inflammatory diseases.

Salvia miltiorrhiza compounds protect the liver from acute injury by regulation of p38 and NFκB signaling in Kupffer cells

CONTEXT

Salvia miltiorrhiza Bunge is a traditional Asian medicine used to treat cerebral and cardiac ischemia. However, the effects of the active compounds of S. miltiorrhiza on liver damage are unclear.

OBJECTIVE

In this study, we tested the effects on acute liver injury of crude S. miltiorrhiza extracts from roots as well as neotanshinone B, dehydromiltirone, tanshinol A, tanshinone I, dihydrotanshinono I, neotanshinone A, cryptanshinono, tanshinone II A, and salvianolie acid B from purified S. miltiorrhiza extracts.

MATERIALS AND METHODS

Various compounds or ethanol extract of S. miltiorrhiza (50, 100, and 200 mg/kg, p.o.) were administered to rats for five consecutive days. After acute carbon tetrachloride (CCl4)-induced liver injury by treatment of rats with a single dose of CCl4 (0.75 mL/kg, p.o), rat liver function was tested by measuring serum biochemical parameters. Serum cytokine concentrations were assessed by enzyme-linked immunosorbent assay (ELISA). Expression of p38 and NFκB was evaluated by western blot.

RESULTS

All S. miltiorrhiza components showed their effects on liver function from the dose from 50 to 200 mg/kg. At the dose of 200 mg/kg, they reduced serum levels of alkaline phosphatase (ALP) by 34-77%, alanine aminotransferase (ALT) by 30-57%, aspartate aminotransferase (AST) by 43-72%, creatine total bilirubin (BIL-T) by 33-81%, albumin (ALB) by 37-67%, indicating that S. miltiorrhiza extracts protected liver from CCl4-induced damage. Moreover, S. miltiorrhiza extracts at 200 mg/kg reduced the increase in the proinflammatory cytokines tumor necrosis factor-α (TNF-α) by 25-82%, interleukin-1 (IL-1) by 42-74% and interleukin-6 (IL-6) by 67-83%, indicating an effect on alleviating liver inflammation. Furthermore, in vitro, S. miltiorrhiza extracts inhibited p38 and NFκB signaling in Kupffer cells. This effect could be a main mechanism by which S. miltiorrhiza protects against acute liver toxicity.

DISCUSSION AND CONCLUSION

Active compounds of S. miltiorrhiza protected the liver from CCl4-induced injury. Protection might have been due to inhibition of p38 and NFκB signaling in Kupffer cells, which subsequently reduced inflammation in the liver.

Induction of m2 polarization in primary culture liver macrophages from rats with acute pancreatitis

Background and Aims

Systemic inflammatory response syndrome (SIRS), a major process of severe acute pancreatitis (SAP), usually occurs after various activated proinflammatory cytokines, which are produced by macrophages such as liver macrophages. Macrophages can secrete not only proinflammatory mediators but also inhibitory inflammatory cytokines such as IL-10, leading to two different functional states defined as “polarization”. The main purpose of this study was to demonstrate the polarization of liver macrophages during severe acute pancreatitis and to explore whether the polarization of these activated Liver macrophages could be reversed in vitro.

Methods

Liver macrophages were isolated from rats with acute pancreatitis. These primary culture macrophages were treated with IL-4 or regulatory T cells in vitro to reverse their polarization and was evaluated by measuring M1/M2 marker expression using real time PCR and immunofluorescence staining.

Results

Acute pancreatitis was induced successfully by intra-pancreatic ductal injection of 5% sodium taurocholate. The liver macrophages demonstrated M1 polarization from 4 h to 16 h after the onset of acute pancreatitis. However, after IL-4 or Treg treatment, the polarization of the liver macrophages was reversed as indicated by increased expression of M2 markers and reduced expression of M1 markers. Furthermore, the effect of Treg on modulating macrophage polarization was slightly better than that of IL-4 in vitro.

Conclusion

Liver macrophages, a pivotal cell type in the pathogenesis of SAP, become M1 polarized during pancreatic inflammation. Treatment of these cells with IL-4 and Treg can reverse this activation in vitro. This method of altering macrophage polarization could be a prospective therapy for SAP.

Phase IV prospective clinical study to evaluate the effect of taurine on liver function in postsurgical adult patients requiring parenteral nutrition

BACKGROUND

Taurine's role in bile acid metabolism and anti-inflammatory activity could exert a protective effect on hepatobiliary complications associated with parenteral nutrition (PN). In this study, the effects of 2 amino acid solutions, with and without taurine, on liver function administered to nonacutely ill postsurgical patients as part of a short-term PN regimen were prospectively compared.

METHODS

Adult patients randomly received (double-blind) Tauramin 10% or a standard PN solution without taurine as the control (1.5 g amino acid/kg body weight [bw]/d; infusion rate of ≤4 mg glucose/kg bw/d) for a period of 5-30 days. γ-Glutamyl transpeptidase (GGT) and other indicators of liver function, glucose metabolism, lipid profile, inflammation markers, and treatment safety data were collected.

RESULTS

Thirty-five patients receiving taurine PN and 39 receiving control PN were enrolled (intention-to-treat [ITT] population). Most patients (n = 62) discontinued after day 7 of follow-up (per-protocol [PP] population: n = 24 and n = 27, respectively). ITT patients with high GGT values after 5 days of PN comprised 68.6% and 64.1%, respectively. The mean change in GGT values with respect to the baseline values was 167 ± 192 and 157 ± 185 IU/L, respectively. Low-density lipoprotein (LDL) cholesterol levels after 7 days of PN were significantly decreased in the taurine PN group of PP patients (-2.83 ± 30.9 vs 23.9 ± 27.0 mg/dL for control PN; P < .05). None of the adverse events reported (taurine PN: n = 6; control PN: n = 7) were treatment related.

CONCLUSION

PN solutions with and without taurine had similar effects on liver function parameters, except for an LDL reduction in PN with taurine, when administered to nonacutely ill postsurgical patients in the short term (5-7 days).

Liposomal clodronate reduces Akt and mitogen-activated protein kinase expression in the intestinal mucosa of rats with severe acute pancreatitis

AIM: To study the effect of liposomal clodronate on the expression of protein kinase B (Akt) and mitogen-activated protein kinase [MAPK (ERK1/2)] in the intestinal mucosa of rats with severe acute pancreatitis (SAP), and to investigate the mechanism behind the therapeutic effect of liposomal clodronate on SAP-associated intestinal mucosal injury.

METHODS: Liposomal clodronate was prepared by means of thin film. Forty-eight SD rats were randomly divided into a model control group (C), a liposome control group (P), and a liposomal clodronate group (T). SAP was induced in rats of groups P and T by injection of sodium taurocholate under the pancreatic capsule, while group C received equal volume of normal saline. Serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and AMS were measured 2 and 6 h after SAP induction. Pathological alterations in the intestinal mucosa were observed.

RESULTS: Serum levels of AMS, IL-6 and TNF-α were significantly elevated in group P compared to group C (all P < 0.01). Compared with group P, serum levels of AMS, IL-6 and TNF-α were significantly decreased in group T (all P < 0.01). Pathological alterations (scores) in the intestinal mucosa were significantly attenuated in group T compared to group P. The expression of Akt and MAPK (ERK1/2) was significantly decreased in group T compared to group P.

CONCLUSION: Macrophages play an important role in the pathogenesis of intestinal mucosal injury in SAP. Macrophages can be depleted via phagocytosis of liposome encapsulated clodronate. Liposomal clodronate alleviates intestinal mucosal injury in SAP rats possibly by decreasing the expression of Akt and MAPK (ERK1/2).

Construction of network for protein kinases that play a role in acute pancreatitis

OBJECTIVES

This study aimed to search for protein kinases that play a role in acute pancreatitis and analyze their potential connection with each other.

METHODS

Information of human protein kinases were collected in protein kinase database, and then a systematic search was performed using PubMed for studies addressing the association between these kinases and acute pancreatitis. Gene Ontology Annotations were used to build interactions network for acute pancreatitis-associated protein kinases.

RESULTS

A total of 570 human protein kinases were found, in which 28 kinases play a role in acute pancreatitis. Among the 28 kinases, RIPK1, JAK2, SRC, EGFR, FYN, MET, JAK1, TYK2, and MTOR were annotated in Gene Ontology database. A gene ontology interactions network was built to visualize the common biological process these kinases participated in.

CONCLUSIONS

This study provides observations that protein kinases participate in all the sequential events in the exocrine pancreas in acute pancreatitis and that protein kinases are potential therapeutical target for acute pancreatitis.

The role of hyperosmotic stress in inflammation and disease

Hyperosmotic stress is an often overlooked process that potentially contributes to a number of human diseases. Whereas renal hyperosmolarity is a well-studied phenomenon, recent research provides evidence that many non-renal tissues routinely experience hyperosmotic stress that may contribute significantly to disease initiation and progression. Moreover, a growing body of evidence implicates hyperosmotic stress as a potent inflammatory stimulus by triggering proinflammatory cytokine release and inflammation. Under physiological conditions, the urine concentrating mechanism within the inner medullary region of the mammalian kidney exposes cells to high extracellular osmolarity. As such, renal cells have developed many adaptive strategies to compensate for increased osmolarity. Hyperosmotic stress is linked to many maladies, including acute and chronic, as well as local and systemic, inflammatory disorders. Hyperosmolarity triggers cell shrinkage, oxidative stress, protein carbonylation, mitochondrial depolarization, DNA damage, and cell cycle arrest, thus rendering cells susceptible to apoptosis. However, many adaptive mechanisms exist to counter the deleterious effects of hyperosmotic stress, including cytoskeletal rearrangement and up-regulation of antioxidant enzymes, transporters, and heat shock proteins. Osmolyte synthesis is also up-regulated and many of these compounds have been shown to reduce inflammation. The cytoprotective mechanisms and associated regulatory pathways that accompany the renal response to hyperosmolarity are found in many non-renal tissues, suggesting cells are commonly confronted with hyperosmotic conditions. Osmoadaptation allows cells to survive and function under potentially cytotoxic conditions. This review covers the pathological consequences of hyperosmotic stress in relation to disease and emphasizes the importance of considering hyperosmolarity in inflammation and disease progression.