The mRNA expression patterns of tumor necrosis factor-α and TNFR-I in some vital organs after thermal injury

AIM: To investigate changes of tumor necrosis factor-α (TNF-α and TNFR-I expression in vital organs and their significance in the pathogenesis of multiple organ damage associated with endogenous endotoxin following major burns.METHODS: Wistar rats subjected to a 35% full-thickness scald injury were sacrificed at 12h, 24h, 48h, and 72 hpostburn, respectively. Meanwhile, eight rats were taken as normal controls. Tissue samples from liver, spleen, kidney,lung and intestine were collected to assay tissue endotoxin levels and measure TNF-α and TNFR-I expression. In addition, blood samples were obtained for the determination of organ function parameters.RESULTS: Endotoxin levels in liver, spleen and lung increased markedly after thermal injury, with the highest level in liver. The gene expression of TNF-α in liver, lung and kidney was up-regulated after thermal injury, while the TNFR-I mRNA expression in liver, lung, kidney and intestine was shown decreased throughout the observation period. Thus, the mRNA expression ratio of TNF-α to TNFR-I was significantly increased postburn, particularly in pulmonary tissue (67-fold). In addition, the significant correlations between the expression of TNFR-I or the expression ratio of TNF-α/TNFR mRNA in liver tissue and serum aspartate aminotransferase levels were noted (P<0.05-0.01). Similar results were also obtained between pulmonary TNF-α mRNA expression and myeloperoxidase activities (P<0.01), whereas there was a highly negative correlation between levels of renal TNFR-I mRNA expression and serum creatinine.CONCLUSION: Burn injury could result in the translocation of gut-derived endotoxin that was mainly distributed in the liver, spleen and lung. The translocated endotoxin then made the expression of TNF-α and TNFR-I mRNA up-regulated and down-regulated respectively in various organs, which might be involved in the pathogenesis of multiple organ damage following burns.     

The mRNA expression patterns of tumor necrosis factor-α and TNFR-I in some vital organs after thermal injury

AIM: To investigate changes of tumor necrosis factor-α (TNFα) and TNFR-Ⅰ expression in vital organs and their significance in the pathogenesis of multiple organ damage associated with endogenous endotoxin following major burns.METHODS: Wistar rats subjected to a 35 % full-thickness scald injury were sacrificed at 12 h, 24 h, 48 h, and 72 h postburn, respectively. Meanwhile, eight rats were taken as normal controls. Tissue samples from liver, spleen, kidney,lung and intestine were collected to assay tissue endotoxin levels and measure TNF-α and TNFR-Ⅰ expression, In addition, blood samples were obtained for the determination of organ function parameters.RESULTS: Endotoxin levels in liver, spleen and lung increased markedly after thermal injury, with the highest level in liver. The gene expression of TNF-α in liver, lung and kidney was up-regulated after thermal injury, while the TNFR-Ⅰ mRNA expression in liver, lung, kidney and intestine was shown decreased throughout the observation period. Thus, the mRNA expression ratio of TNF-α to TNFRⅠ was significantly increased postburn, particularly in pulmonary tissue (67-fold). In addition, the significant correlations between the expression of TNFR-Ⅰ or the expression ratio of TNF-α/TNFR mRNA in liver tissue and serum aspartate aminotransferase levels were noted (P ＜0.05-0.01). Similar results were also obtained between pulmonary TNF-α mRNA expression and myeloperoxidase activities (P＜0.01), whereas there was a highly negative correlation between levels of renal TNFR-Ⅰ mRNA expression and serum creatinine.CONCLUSION: Burn injury could result in the translocation of gut-derived endotoxin that was mainly distributed in the liver, spleen and lung. The translocated endotoxin then made the expression of TNF-α and TNFR-Ⅰ mRNA up-regulated and down-regulated respectively in various organs, which might be involved in the pathogenesis of multiple organ damage following burns.     

Fish oil alleviates liver injury induced by intestinal ischemia/reperfusion via AMPK/SIRT-1/autophagy pathway

AIM To evaluate whether fish oil(FO) can protect liver injury induced by intestinal ischemia/reperfusion(I/R) via the AMPK/SIRT-1/autophagy pathway.METHODS Ischemia in wistar rats was induced by superior mesenteric artery occlusion for 60 min and reperfusion for 240 min. One milliliter per day of FO emulsion or normal saline was administered by intraperitoneal injection for 5 consecutive days to each animal. Animals were sacrificed at the end of reperfusion. Blood andtissue samples were collected for analyses. AMPK, SIRT-1, and Beclin-1 expression was determined in lipopolysaccharide(LPS)-stimulated HepG2 cells with or without FO emulsion treatment.RESULTS Intestinal I/R induced significant liver morphological changes and increased serum alanine aminotransferase and aspartate aminotransferase levels. Expression of p-AMPK/AMPK, SIRT-1, and autophagy markers was decreased whereas tumor necrosis factor-α(TNF-α) and malonaldehyde(MDA) were increased. FO emulsion blocked the changes of the above indicators effectively. Besides, in LPS-stimulated HepG2 cells, small interfering RNA(siRNA) targeting AMPK impaired the FO induced increase of p-AMPK, SIRT-1, and Beclin-1 and decrease of TNF-α and MDA. SIRT-1 siRNA impaired the increase of SIRT-1 and Beclin-1 and the decrease of TNF-α and MDA.CONCLUSION Our study indicates that FO may protect the liver against intestinal I/R induced injury through the AMPK/SIRT-1/autophagy pathway.     

Alleviation of ischemia/reperfusion injury in ob/ob mice by inhibiting UCP-2 expression in fatty liver

AIM： To investigate the protective effect of target suppression of uncoupling protein-2 （UCP-2） on ischemia/ reperfusion （I/R） injury in fatty liver in ob/ob mice. METHODS： Plasmids suppressing UCP-2 expression were constructed, and transfected into fatty liver cells cultured in vitro and the ob/ob mouse I/R injury model. Serum tumor necrosis factor （TNF）-α levels, UCP-2 mRNA expression, alanine aminotransferase （ALT） levels in ob/ob mice were tested, and the pathological changes in fatty liver were observed in experimental and control groups. RESULTS： In ob/ob mouse I/R models, serum TNF-α levels were significantly higher than in normal controls. After the plasmids were transfected into the cultured cells and animal models, expression of UCP-2 rnRNA was significantly reduced as compared with that in the control group （2^1.56± 0.15 vs 2^-0.45± 0.15, p 〈 0.05）. In ob/ob mouse models, in which expression of UCP-2 was suppressed, serum ALT levels were significantly lower than those of other groups, and pathological analysis revealed that injury of liver tissues was significantly alleviated. CONCLUSION： The target suppression of UCP-2 expression in fatty liver can alleviate the I/R injury in the ob/ob mice.     

Ischemic preconditioning decreases C-X-C chemokine expression and neutrophil accumulation early after liver transplantation in rats

AIM: Polymorphonuclear neutrophil (PMN) plays a major role in liver ischemia/reperfusion injury. Protective effect of ischemic preconditioning (IP) has been confirmed in liver ischemia/reperfusion injury. The purpose of this study was to investigate the effect of IP on C-X-C chemokine expression and PMNs recruitment eady after liver transplantation.METHODS: Male Sprague-Dawley rats were used as donors and recipients of orthotopic liver transplantation (OLT). The donor liver was stored 24 hours in University of Wisconsin(UW) solution at 4 ℃ pre-implantation, IP was done by damp of the portal vein and hepatic artery of the donor liver for 10 minutes followed by reperfusion for 10 minutes before harvesting. The neutrophilic infiltration in liver was quantified using a myeloperoxidase (MPO) assay. Intragrafl: expression of macrophage inflammatory protein-2 (MIP-2) mRNA was investigated with in situ hybridization, The serum levels of MIP-2 and tumor necrosis factor (TNF)-α were also monitored,RESULTS: After liver transplantation without IP, the hepatic MPO increased significantly compared with sham operated group. In IP group, PMN in liver indicated by MPO was reduced significantly. In situ hybridization showed no MIP-2 mRNA in sham group but dramatic expression in hepatocytes in non-IP group. In IP group, MIP-2 mRNA was significantly down-regulated. Similarly, serum MIP-2 and TNF-α levels were significantly elevated in non-IP group and both were reduced in IP group.CONCLUSION: IP might protect graft liver from preservation-reperfusion injury after OLT through down-regulating C-X-C chemokine expression of hepatocytes, and alleviating PMNs recruitment after reperfusion.     

Gasdermin D-mediated hepatocyte pyroptosis expands inflammatory responses that aggravate acute liver failure by upregulating monocyte chemotactic protein 1/CC chemokine receptor-2 to recruit macrophages

BACKGROUND Massive hepatocyte death is the core event in acute liver failure(ALF).Gasdermin D(GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death. However, the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear.AIM To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis through in vitro and in vivo experiments.METHODS The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot.GSDMD short hairpin RNA(sh RNA) was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1(MCP1) and its receptor CC chemokine receptor-2(CCR2) in vitro. For in vivo experiments, we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide(D-Galn/LPS)-induced ALF mouse model.RESULTS The levels of pyroptosis pathway-associated proteins in liver tissue from ALFpatients and a hepatocyte injury model increased significantly. The level of GSDMD-N protein increased most obviously(P 0.001). In vitro, downregulation of GSDMD by sh RNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins(P 0.01). In vivo, GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of DGaln/LPS-induced ALF mice(P 0.001). Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin(IL)-1β and IL-18, GSDMDmediated hepatocyte pyroptosis recruited macrophages via MCP1/CCR2 to aggravate hepatocyte death. However, this pathological process was inhibited after knocking down GSDMD.CONCLUSION GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF, recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses. GSDMD knockout can reduce hepatocyte death and inflammatory responses, thus alleviating ALF.     

Protective effect of melatonin against liver injury in mice induced by Bacillus Calmette-Guerin plus lipopolysaccharide

AIM: To investigate the effects and mechanisms of melatonin on immunological liver injury in mice.METHODS: A model of liver injury was induced by tail vein injecton of Bad#us Calmet~ Guenn (BCG) and lipopolysaccharide(LPS) in mice. Kupffer cells and hepatocytes were isolated and cultured according to a modified two-step collagenase perfusion technique. Levels of alanine aminotransferase(ALT), aspartate aminotransferase (AST) and nitric oxide(NO), content of malondiadehyde (MDA), activity of superoxide dismutase (SOD), were measured by biochemical methods.Tumor necrosis factor-α (TNF-α) activity was determined by RIA. Interleukin (IL)-1 activity was measured by thymocyte proliferation bioassay. Hepatic tissue sections were stained with hematoxylin and eosin and examined under a lightmicroscope.RESULTS: Immunological liver injury induced by BCG+LPS was successfully duplicated. Serum transaminase (ALT,AST) activities were significantly decreased by melatonin(0.25, 1.0, 4.0 mg/kg bm). Meanwhile, MDA content was decreased and SOD in liver homogenates was upregulated.Furthermore, pro-inflammatory mediators (TNF-α, IL-1, NO)in serum and liver homogenates were significantly reduced by melatonin. Histological examination demonstrated that melatonin could attenuate the area and extent of necrosis,reduce the immigration of inflammatory cells. In in vitro experiment, TNF-α was inhibited at the concentrations of 10^-8-10^-6 mol/L of melatonin, while IL-1 production of Kupffer cells induced by LPS (5 t~g/mL) was decreased only at the concentration of 10^-6 mol/L of melatonin, but no effect on NO production was observed. Immunological liver injury model in vitro was established by incubating hepatocytes with BCG- and LPS-induced Kupffer cells. Activities of ALT,TNF-α, IL-1, and MDA in supernatant were significantly increased. Melatonin had little effect on the level of ALT,but reduced the content of TNF-α and MDA at concentrations of 10^-7-10^-5 mol/L and decreased the content of IL-1 at concentrations of 10^-6-10^-5 mol/L.CONCLUSION: Melatonin could significantly protect liver injury in mice, which was related to free radical scavenging,increased SOD activity and pro-inflammatory mediators.     

Downregulation of retinoic acid receptor-β2expression is linked to aberrant methylation in esophageal squamous cell carcinoma cell lines

AIM:To study the role of hypermethylation in the loss of retinoic acid receptor β2(RARβ2) in esophageal squamous cell carcinoma (ESCC).METHODS:The role of hypermethylation in RARβ2 gene silencing in 6 ESCC cell lines was determined by methylation-specific PCR (MSP),and its methylation status was compared with RARβ2 mRNA expression by RT-PCR.The MSP results were confirmed by bisulfite sequencing of RARβ2promoter regions.RESULTS:Methylation was detected in 4 of the 6 cell lines,and the expression of RARβ2 was markedly downregulated in 3 of the 4 methylated cell lines. The expression of RARβ2 was restored in one RARβ2-downregulated cell line with the partial demethylation of promoter region of RARβ2 after 5-aza-2′-deoxycytidine (5-aza-dc) treatment.CONCLUSION:The methylation of the 5′ region may play an important role in the downregulation of RARβ2 in some ESCC cell lines, suggesting that multiple mechanisms contribute to the loss of RARβ2expression in ESCC cell lines.This study may have clinical applications for treatment and prevention of ESCC.     

Autophagy activation by Jiang Zhi Granule protects against metabolic stress-induced hepatocyte injury

AIM To elucidate the potential role of autophagy and the protective effects of Jiang Zhi Granule(JZG) in metabolic stress-induced hepatocyte injury.METHODS An in vitro and in vivo approach was used in this study. Hep G2 cells were incubated in culture medium containing palmitate(PA; 0, 0.1, 0.2, 0.3, 0.4 or 0.5 mmol/L) and treated with or without JZG(100 μg/m L) for 24 h or 48 h, and the progression of autophagy was visualized by stable fluorescence-expressing cell lines LC3 and p62. Western blot analyses were performed to examine the expression of LC3-Ⅱ/LC3-Ⅰ, p62, m TOR and PI3 K, while mitochondrial integrity and oxidative stress were observed by fluorescence staining of JC-1 and reactive oxygen species. C57 BL/6 mice were divided into three groups: control group(n = 10), high fat(HF) group(n = 13) and JZG group(n = 13); and, histological staining was carried out to detect inflammation and lipid content in the liver.RESULTS The cell trauma induced by PA was aggravated in a dose-and time-dependent manner, and hepatic function was improved by JZG. PA had dual effects on autophagy by activating autophagy induction and blocking autophagic flux. The PI3 K-AKT-m TOR signaling pathway and the fusion of isolated hepatic autophagosomes and lysosomes were critically involved in this process. JZG activated autophagy progression by either induction of autophagosomes or co-localization of autophagosomes and lysosomes as well as degradation of autolysosomes to protect against PA-induced hepatocyte injury, and protected mitochondrial integrity against oxidative stress in PA-induced mitochondrial dysfunction. In addition, JZG ameliorated lipid droplets and inflammation induced by HF diet in vivo, leading to improved metabolic disorder and associated liver injury in a mouse model of non-alcoholic fatty liver disease(NAFLD).CONCLUSION Metabolic stress-induced hepatocyte injury exhibited dual effects on autophagy and JZG activated the entire process, resulting in beneficial effects in NAFLD.     

Inhibitory effect of oxymatrine on hepatocyte apoptosis via TLR4/PI3K/Akt/GSK-3β signaling pathway

AIM To evaluate the effect of oxymatrine(OMT) on hepatocyte apoptosis in rats with lipopolysaccharide(LPS)/D-galactosamine(D-Gal N)-induced acute liver failure(ALF). METHODS LPS/D-Gal N was used to establish a model of ALF in rats. To evaluate the effect of OMT, we assessed apoptosis by transmission electron microscopy, and the pathological changes in the liver by light microscopy with hematoxylin and eosin staining. An automated biochemical analyzer was used to measure serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST). Enzyme-linked immunosorbent assay was used to determine the levels of tumor necrosis factor(TNF)-α and interleukin(IL)-1β. Western blotting was used to detect protein levels in liver tissues. Streptavidin peroxidase immunohistochemistry was used to observe expression of Toll-like receptor(TLR)4, active caspase-3, Bax and Bcl-2. RESULTS All rats in the normal control and OMT-pretreated groups survived. The mortality rate in the model group was 30%. OMT preconditioning down-regulated apoptosis of hepatocytes and ameliorated pathological changes in liver tissue. The levels of AST, ALT, TNF-α and IL-1β in the model group increased significantly, and were significantly reduced by OMT pretreatment. OMT pretreatment down-regulated expression of TLR4 and active caspase-3 and the Bax/Bcl-2 ratio, and upregulated expression of P-AktSer473(Akt phosphorylated at serine 473) and P-GSK3βSer9(glycogen synthase kinase 3β phosphorylated at serine 9) induced by LPS/D-Gal N. CONCLUSION OMT inhibits hepatocyte apoptosis by suppressing the TLR4/PI3K/Akt/GSK-3β signaling pathway, which suggests that OMT is an effective candidate for ameliorating acute liver failure.     

Neutrophil-mediated liver injury during hepatic ischemia-reperfusion in rats

BACKGROUND: Neutrophil plays an important role in hepatic ischemia-reperfusion injury. We investigated neutrophil infiltration in liver tissue, Kupffer cells' role in neutrophil accumulation, and apoptosis and regeneration of hepatocytes in liver ischemia-reperfusion injury. METHODS: Vascular microclamps were placed across the pedicles of the median and left lateral lobes for 90 minutes after 30% hepatectomy with the resection of caudate, right lateral and quadrate lobes and papillary process. Gadolinium chloride (GdCl3) was used to destroy Kupffer cells. Neutrophil activity was inhibited with Urge-8, a monoclonal antibody against neutrophil produced in our laboratory. GdCl3 (10 mg/kg) and Urge-8 (50 mg/kg) were given intravenously in respective groups. Ischemia control, GdCl3 and Urge-8 groups were compared. RESULTS: Following hepatic reperfusion, serum interleukin-8 (IL-8) levels and hepatic neutrophil counts peaked at 3 hours, and peak concentrations of alanine aminotransferase (ALT) occurred at 6 hours. Animals of the control group showed increases in neutrophil infiltration in liver tissue, liver enzyme levels, and apoptosis index of hepatocytes and decreases in overall survival rate and proliferating cell nuclear antigen (PCNA) expression of hepatocytes. The survival rates and PCNA proportion of hepatocytes were higher and the levels of hepatic neutrophil infiltration, liver enzymes, and hepatocyte apoptosis after reperfusion were lower in the GdCl3 and Urge-8 groups than those in the ischemia control group. CONCLUSIONS: Blockades of Kupffer cells' activity and neutrophil infiltration by GdCl3 and Urge-8 eliminate neutrophil-mediated hepatic injury and enhance subsequent hepatic regeneration during liver ischemiareperfusion.     

TLR4 mediates LPS-induced HO-1 expression in mouse liver： Role of TNF-α and IL-lβ

AIM: Heme oxygenase (HO)-I catalyzes the conversion of heme to biliverdin, iron and carbon monoxide. HO-1 is induced by many stimuli including heme, Hb, heat stress,lipopolysaccharide (LP5) and cytokines. Previous studies demonstrated that LP5 induced HO-1 gene activation and HO-1 expression in liver. However, the mechanisms of LPS-induced HO-1 expression in liver remain unknown. The effect of toll-like receptor-4 (TLR4) on LPS-induced liver HO-1 expression and the role of TNF-α and IL-1β in this condition were determined.METHODS: HO-1 expression was determined by immunofluorescent staining and immunoblotting. Double immunofluorescent staining was performed to determine the cell type of HO-1 expression in liver.RESULTS: A low dose of LPS significantly increased HO-1 expression in the liver which was localized in Kupffer cells only. Furthermore, HO-1 expression was enhanced by three doses of LPS. HO-1 expression was significantly inhibited in the liver of TLR4 mutant mice. While the liver HO-1 expression in TNF KO mice was much lower than that in C57 mice following the same LPS treatment, IL-1β KO had a slight influence on liver HO-1 expression following LPS treatment.CONCLUSION: The preserfl: results confirm that macrophages are the major source of HO-1 in the liver induced by LPS.This study demonstrates that TLR4 plays a dominant role in mediating HO-1 expression following LPS. LPS-induced HO-1 expression is mainly mediated by endogenous TNF-α, but only partially by endogenous IL-1β.     

The role of endotoxin,TNF—α,and IL—6 in inducing the state of growth hormone insensitivity

AIM：Critical illnesses such as sepsis,trauma,and burns cause a growth hormone insensitivity,wehich leads to an increased negative nitrogen balance.Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-α,IL-6,and IL-1 which may play a very important role in inducing the growth hormone insensitivity,The objective of this current study was to investigate the role of endotoxin,TNFα and IL-6 in inducing the growth hormone insensityvity at the receptor and post-receptor levels.METHODS:Spageu-Dawley rats were injected with endotoxin,TNF-α,and IL-6,respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously,All rats were killed at different time points,The expression of IGF-I,GHR,SOCS-3 and β-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay,the levels of TNF-α and IL-6 were detected by ELISA.RESULTS:There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection,However,liver IGF-1 mRNA expression had been obviously down-regulated in endotoxeminc rats.Liver GHR mRNA expression also had a predominant downregulation after endotoxin injection,The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection,being decreased by 53% compared with control rats.For GHR mRNA expression,the lowest expression occurred at 8h and had a 81% decrease.Although SOCS-3 mRNA was weakly expressed in control rats,it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats.Exogenous GH could enhance IGF-1 mRNA expression in control rats,but if did fail to prevent the decline in IGF-1 mRNA expression in endotoxemic rats,Endotoxin stimulated the production of TNF-α and IL-6,and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression.The liver GHR mRNA expression was obviously down-regulated after TNF-α iv injection and had a 40 decresase at 8 h,but the liver socs-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection.CONCLUSION:The growth homone insenstivity could be induced by LPS injection,which was associated with down regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level The in vivo biological activities of LPS were mediated by TNF-α and IL-6 indirectly,and TNF-αand IL-6 may exert their effects on.the receptor and post-receptor levels respectively.     

Effect of 2-amino-2-[2-（4-octylphenyl） ethyl] propane-1,3-diol hydrochloride （FTY 720） on immune liver injury in mice

AIM: To investigate the protective effect against two immune liver injury models in mice by 2-amino-2-[2-(4-octylphenyl) ethyl] propane-l,3-diol hydrochloride and its possible mechanisms in Con A-induced liver damage. METHODS: Liver tissue or hepatocyte injury was monitored biochemically by measuring alanine aminotransferase (sALT) and aspartate aminotransferase (sAST) activity. Hematoxylin & eosin (HE) staining was used for histopathological examination. To evaluate the role of IFN-γ and IL-4 in the liver injury, serum levels of IFN-γ and IL-4 were determined using commercially available ELISA kit at 12 h after Con A challenge. We also determined FTY 720-induced spleen cell apoptosis by flow cytometry analysis or spleen cell proliferation test. RESULTS: Different doses of FTY 720 treatment dramatically reduced circulating markers of hepatocyte injury in two kinds of immunological liver injury models. FTY 720 dramatically reduced the elevated serum IFN-γ and IL-4 levels after Con A injection. Effect of spleen cell supernatants treated with Con A or FTY 720 on hepatocytes showed that ALT activities in cultured hepatocyte supernatants in Con A treatment group increased markedly and FTY 720 could reduce this elevated ALT activities in FTY 720 treatment group. FTY 720 dose-dependently increased the percentage of apoptotic cells in T cells and inhibited splenocyte proliferation induced by Con A. CONCLUSION: Pretreatment with FTY 720 was shown to produce protective effect on the immune liver injury in mice. The possible mechanism of FTY 720 on Con A-induced liver damage is that it could inhibit lymphocyte proliferation and induce lymphocyte apoptosis, resulting in the reduction of IL-4 or IFN-γ release, and subsequently protecting liver from being damaged by Con A.     

Anti-oxidant and anti-inflammatory effects of hydrogenrich water alleviate ethanol-induced fatty liver in mice

AIM To investigate the effects of hydrogen-rich water(HRW) treatment on prevention of ethanol(Et OH)-induced early fatty liver in mice.METHODS In vitro reduction of hydrogen peroxide by HRW was determined with a chemiluminescence system. Female mice were randomly divided into five groups: control,Et OH,Et OH + silymarin,Et OH + HRW and Et OH + silymarin + HRW. Each group was fed a Lieber-De Carli liquid diet containing Et OH or isocaloric maltose dextrin(control diet). Silymarin was used as a positive control to compare HRW efficacy against chronic Et OH-induced hepatotoxicity. HRW was freshly prepared and given at a dosage of 1.2 m L/mouse trice daily. Blood and liver tissue were collected after chronic-binge liquid-diet feeding for 12 wk.RESULTS The in vitro study showed that HRW directly scavenged hydrogen peroxide. The in vivo study showed that HRW increased expression of acyl ghrelin,which was correlated with food intake. HRW treatment significantly reduced Et OH-induced increases in serum alanine aminotransferase,aspartate aminotransferase,triglycerol and total cholesterol levels,hepatic lipid accumulation and inflammatory cytokines,including tumor necrosis factor-alpha(TNF-α) and interleukin(IL)-6. HRW attenuated malondialdehyde level,restored glutathione depletion and increased superoxide dismutase,glutathione peroxidase and catalase activities in the liver. Moreover,HRW reduced TNF-α and IL-6 levels but increased IL-10 and IL-22 levels.CONCLUSION HRW protects against chronic Et OH-induced liver injury,possibly by inducing acyl ghrelin to suppress the pro-inflammatory cytokines TNF-α and IL-6 and induce IL-10 and IL-22,thus activating antioxidant enzymes against oxidative stress.     

β-arrestin 2 attenuates lipopolysaccharide-induced liver injury via inhibition of TLR4/NF-κB signaling pathwaymediated inflammation in mice

AIM To study the role and the possible mechanism of β-arrestin 2 in lipopolysaccharide(LPS)-induced liver injury in vivo and in vitro.METHODS Male β-arrestin 2~(+/+) and β-arrestin 2~(-/-)C57 BL/6 J mice were used for in vivo experiments, and the mouse macrophage cell line RAW264.7 was used for in vitro experiments. The animal model was established via intraperitoneal injection of LPS or physiological sodium chloride solution. Blood samples and liver tissues were collected to analyze liver injury and levels of pro-inflammatory cytokines. Cultured cell extracts were collected to analyze the production of pro-inflammatory cytokines and expression of key molecules involved in the TLR4/NF-κB signaling pathway.RESULTS Compared with wild-type mice, the β-arrestin 2 knockout mice displayed more severe LPS-induced liver injury and significantly higher levels of proinflammatory cytokines, including interleukin(IL)-1β, IL-6, tumor necrosis factor(TNF)-α, and IL-10. Compared with the control group, pro-inflammatory cytokines(including IL-1β, IL-6, TNF-α, and IL-10) produced by RAW264.7 cells in the β-arrestin 2 si RNA group were significantly increased at 6 h after treatment with LPS. Further, key molecules involved in the TLR4/NF-κB signaling pathway, including phosphoIκBα and phosho-p65, were upregulated.CONCLUSION β-arrestin 2 can protect liver tissue from LPS-induced injury via inhibition of TLR4/NF-κB signaling pathwaymediated inflammation.