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Sample records for activity increased hepatic

  1. Increased serum cortisol binding in chronic active hepatitis

    SciTech Connect

    Orbach, O.; Schussler, G.C.

    1989-01-01

    A high serum cortisol concentration, apparently due to increased cortisol-binding globulin (CBG), was found in a patient (index case) with chronic active hepatitis (CAH). We therefore performed further studies to determine whether increased cortisol binding is generally associated with CAH. Serum samples were obtained from 15 hospitalized patients with long-term liver function test elevations but no evidence of cirrhosis, 15 normal subjects without a history of hepatitis, four healthy pregnant women, and 10 alcoholic patients with stigmata of cirrhosis. Serum cortisol binding was measured by an adaptation of a previously described charcoal uptake method. Thyroxine-binding globulin (TBG) and sex hormone-binding globulin were determined by radioimmunoassays. Charcoal uptake of 125I cortisol from sera of normal subjects and additional patients with CAH revealed that increased serum cortisol binding by a saturable site, presumably CBG, was associated with CAH. Cortisol binding was significantly correlated with immunoassayable TBG, suggesting that in CAH, similar mechanisms may be responsible for increasing the serum concentrations of CBG and TBG.

  2. Increased physical activity decreases hepatic free fatty acid uptake: a study in human monozygotic twins

    PubMed Central

    Hannukainen, Jarna C; Nuutila, Pirjo; Ronald, Borra; Kaprio, Jaakko; Kujala, Urho M; Janatuinen, Tuula; Heinonen, Olli J; Kapanen, Jukka; Viljanen, Tapio; Haaparanta, Merja; Rönnemaa, Tapani; Parkkola, Riitta; Knuuti, Juhani; Kalliokoski, Kari K

    2007-01-01

    Exercise is considered to be beneficial for free fatty acid (FFA) metabolism, although reports of the effects of increased physical activity on FFA uptake and oxidation in different tissues in vivo in humans have been inconsistent. To investigate the heredity-independent effects of physical activity and fitness on FFA uptake in skeletal muscle, the myocardium, and liver we used positron emission tomography (PET) in nine healthy young male monozygotic twin pairs discordant for physical activity and fitness. The cotwins with higher physical activity constituting the more active group had a similar body mass index but less body fat and 18 ± 10% higher V˙O2,max (P < 0.001) compared to the less active brothers with lower physical activity. Low-intensity knee-extension exercise increased skeletal muscle FFA and oxygen uptake six to 10 times compared to resting values but no differences were observed between the groups at rest or during exercise. At rest the more active group had lower hepatic FFA uptake compared to the less active group (5.5 ± 4.3 versus 9.0 ± 6.1 μmol (100 ml)−1 min−1, P = 0.04). Hepatic FFA uptake associated significantly with body fat percentage (P = 0.05). Myocardial FFA uptake was similar between the groups. In conclusion, in the absence of the confounding effects of genetic factors, moderately increased physical activity and aerobic fitness decrease body adiposity even in normal-weighted healthy young adult men. Further, increased physical activity together with decreased intra-abdominal adiposity seems to decrease hepatic FFA uptake but has no effects on skeletal muscle or myocardial FFA uptake. PMID:17053033

  3. Increased hepatic Na,K-ATPase activity during hepatic regeneration is associated with induction of the beta1-subunit and expression on the bile canalicular domain.

    PubMed

    Simon, F R; Fortune, J; Alexander, A; Iwahashi, M; Dahl, R; Sutherland, E

    1996-10-04

    Cellular and molecular mechanisms regulating the activity of the sodium pump or Na,K-ATPase during proliferation of hepatocytes following 70% liver resection have not been defined. Na,K-ATPase may be regulated by synthesis of its alpha- and beta-subunits, by sorting to either the sinusoidal or apical plasma membrane domains, or by increasing membrane lipid fluidity. This study investigated the time course of changes during hepatic regeneration for Na, K-ATPase activity, lipid composition and fluidity, and protein content of liver plasma membrane subfractions. As early as 4 h after hepatic resection, Na,K-ATPase activity was increased selectively in the bile canalicular fraction. It reached a new steady state at 12 h and remained elevated for 2 days. Although hepatic regeneration was associated with a reduced cholesterol/phospholipid molar ratio and increased fluidity, measured with two different probes, these changes in lipid metabolism were in the sinusoidal membrane domain. The Na,K-ATPase beta1-subunit, but not the alpha1-subunit, was increased selectively at the bile canalicular surface as shown by immunoblotting of liver plasma membrane subfractions and the morphological demonstration at both the light and electron microscopic levels. Furthermore, cycloheximide blocked the rise in beta1-subunit mRNA levels. Since the time course for beta1-subunit accumulation was similar to that for activation of Na,K-ATPase activity, this change implicated the beta1-subunit in activating sodium pump activity.

  4. Chronic administration of caderofloxacin, a new fluoroquinolone, increases hepatic CYP2E1 expression and activity in rats

    PubMed Central

    Liu, Li; Miao, Ming-xing; Zhong, Ze-yu; Xu, Ping; Chen, Yang; Liu, Xiao-dong

    2016-01-01

    Aim: Caderofloxacin is a new fluoroquinolone that is under phase III clinical trials in China. Here we examined the effects of caderofloxacin on rat hepatic cytochrome P450 (CYP450) isoforms as well as the potential of caderofloxacin interacting with co-administered drugs. Methods: Male rats were treated with caderofloxacin (9 mg/kg, ig) once or twice daily for 14 consecutive days. The effects of caderofloxacin on CYP3A, 2D6, 2C19, 1A2, 2E1 and 2C9 were evaluated using a “cocktail” of 6 probes (midazolam, dextromethorphan, omeprazole, theophylline, chlorzoxazone and diclofenac) injected on d 0 (prior to caderofloxacin exposure) and d 15 (after caderofloxacin exposure). Hepatic microsomes from the caderofloxacin-treated rats were used to assess CYP2E1 activity and chlorzoxazone metabolism. The expression of CYP2E1 mRNA and protein in hepatic microsomes was analyzed with RT-PCR and Western blotting, respectively. Results: Fourteen-day administration of caderofloxacin significantly increased the activity of hepatic CYP2E1, leading to enhanced metabolism of chlorzoxazone. In vitro microsomal study confirmed that CYP2E1 was a major metabolic enzyme involved in chlorzoxazone metabolism, and the 14-d administration of caderofloxacin significantly increased the activity of CYP2E1 in hepatic microsomes, resulting in increased formation of 6-hydroxychlorzoxazone. Furthermore, the 14-d administration of caderofloxacin significantly increased the expression of CYP2E1 mRNA and protein in liver microsomes, which was consistent with the pharmacokinetic results. Conclusion: Fourteen-day administration of caderofloxacin can induce the expression and activity of hepatic CYP2E1 in rats. When caderofloxacin is administered, a potential drug-drug interaction mediated by CYP2E1 induction should be considered. PMID:26838075

  5. Fish oil at low dietary levels enhances physiological activity of sesamin to increase hepatic fatty acid oxidation in rats.

    PubMed

    Ide, Takashi

    2012-11-01

    We previously demonstrated that a diet containing fish oil at a level of 80 g/kg strongly stimulated the physiological activity of a sesame sesamin preparation containing sesamin and episesamin at equal amounts to increase hepatic fatty acid oxidation. This study was conducted to clarify whether fish oil at lower dietary levels enhances the physiological activity of sesamin to increase hepatic fatty acid oxidation. Rats were fed experimental diets supplemented with 0 or 2 g sesamin/kg, and containing 0, 15 or 30 g fish oil/kg for 15 days. Among rats fed sesamin-free diets, diets containing 15 and 30 g fish oil/kg slightly increased the activity of enzymes involved in hepatic fatty acid oxidation. Sesamin increased these values irrespective of the presence or absence of fish oil in diets; however, the extent of the increase of many parameters was much greater in rats given fish oil-containing diets than in those fed a fish oil-free diet. Diets simultaneously containing sesamin and fish oil increased the gene expression of various peroxisomal fatty acid oxidation enzymes in a synergistic manner; but they were ineffective in causing a synergistic increase in mRNA levels of mitochondrial fatty acid oxidation enzymes. The extent of the synergistic increase in the activity of hepatic fatty acid oxidation enzymes and mRNA levels of the peroxisomal enzymes was indistinguishable between diets containing 15 and 30 g fish oil/kg and appeared comparable to that observed previously with a diet containing 80 g fish oil/kg.

  6. Myricetin Increases Hepatic Peroxisome Proliferator-Activated Receptor α Protein Expression and Decreases Plasma Lipids and Adiposity in Rats

    PubMed Central

    Chang, Chia Ju; Tzeng, Thing-Fong; Liou, Shorong-Shii; Chang, Yuan-Shiun; Liu, I-Min

    2012-01-01

    The aim of this study was to investigate the antiobesity and antihyperlipidaemic effects of myricetin. Myricetin exhibited a significant concentration-dependent decrease in the intracellular accumulation of triglyceride in 3T3-L1 adipocytes. The high-fat diet (HFD)-fed rats were dosed orally with myricetin or fenofibrate, once daily for eight weeks. Myricetin (300 mg kg−1 per day) displayed similar characteristics to fenofibrate (100 mg kg−1 per day) in reducing lowered body weight (BW) gain, visceral fat-pad weights and plasma lipid levels of HFD-fed rats. Myricetin also reduced the hepatic triglyceride and cholesterol contents, as well as lowered hepatic lipid droplets accumulation and epididymal adipocyte size in HFD-fed rats. Myricetin and fenofibrate reversed the HFD-induced down-regulation of the hepatic peroxisome proliferator activated receptor (PPAR)α. HFD-induced decreases of the hepatic protein level of acyl-CoA oxidase and cytochrome P450 isoform 4A1 were up-regulated by myricetin and fenofibrate. The elevated expressions of hepatic sterol regulatory element binding proteins (SREBPs) of HFD-fed rats were lowered by myricetin and fenofibrate. These results suggest that myricetin suppressed BW gain and body fat accumulation by increasing the fatty acid oxidation, which was likely mediated via up-regulation of PPARα and down-regulation of SREBP expressions in the liver of HFD-fed rats. PMID:22474525

  7. Genetic inhibition of hepatic acetyl-CoA carboxylase activity increases liver fat and alters global protein acetylationa

    PubMed Central

    Chow, Jenny D.Y.; Lawrence, Robert T.; Healy, Marin E.; Dominy, John E.; Liao, Jason A.; Breen, David S.; Byrne, Frances L.; Kenwood, Brandon M.; Lackner, Carolin; Okutsu, Saeko; Mas, Valeria R.; Caldwell, Stephen H.; Tomsig, Jose L.; Cooney, Gregory J.; Puigserver, Pere B.; Turner, Nigel; James, David E.; Villén, Judit; Hoehn, Kyle L.

    2014-01-01

    Lipid deposition in the liver is associated with metabolic disorders including fatty liver disease, type II diabetes, and hepatocellular cancer. The enzymes acetyl-CoA carboxylase 1 (ACC1) and ACC2 are powerful regulators of hepatic fat storage; therefore, their inhibition is expected to prevent the development of fatty liver. In this study we generated liver-specific ACC1 and ACC2 double knockout (LDKO) mice to determine how the loss of ACC activity affects liver fat metabolism and whole-body physiology. Characterization of LDKO mice revealed unexpected phenotypes of increased hepatic triglyceride and decreased fat oxidation. We also observed that chronic ACC inhibition led to hyper-acetylation of proteins in the extra-mitochondrial space. In sum, these data reveal the existence of a compensatory pathway that protects hepatic fat stores when ACC enzymes are inhibited. Furthermore, we identified an important role for ACC enzymes in the regulation of protein acetylation in the extra-mitochondrial space. PMID:24944901

  8. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases human hepatic stellate cell activation.

    PubMed

    Harvey, Wendy A; Jurgensen, Kimberly; Pu, Xinzhu; Lamb, Cheri L; Cornell, Kenneth A; Clark, Reilly J; Klocke, Carolyn; Mitchell, Kristen A

    2016-02-17

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a halogenated aromatic hydrocarbon that elicits toxicity through the aryl hydrocarbon receptor (AhR). In the liver, gross markers of TCDD toxicity are attributed to AhR activation in parenchymal hepatocytes. However, less is known regarding the consequences of TCDD treatment on non-parenchymal cells in the liver. Hepatic stellate cells (HSCs) are non-parenchymal cells that store vitamin A when quiescent. Upon liver injury, activated HSCs lose this storage ability and instead function in the development and maintenance of inflammation and fibrosis through the production of pro-inflammatory mediators and collagen type I. Reports that TCDD exposure disrupts hepatic retinoid homeostasis and dysregulates extracellular matrix remodeling in the liver led us to speculate that TCDD treatment may disrupt HSC activity. The human HSC line LX-2 was used to test the hypothesis that TCDD treatment directly activates HSCs. Results indicate that exposure to 10nM TCDD almost completely inhibited lipid droplet storage in LX-2 cells cultured with retinol and palmitic acid. TCDD treatment also increased LX-2 cell proliferation, expression of α-smooth muscle actin, and production of monocyte chemoattractant protein-1 (MCP-1), all of which are characteristics of activated HSCs. However, TCDD treatment had no effect on Col1a1 mRNA levels in LX-2 cells stimulated with the potent profibrogenic mediator, transforming growth factor-β. The TCDD-mediated increase in LX-2 cell proliferation, but not MCP-1 production, was abolished when phosphoinositide 3-kinase was inhibited. These results indicate that HSCs are susceptible to direct modulation by TCDD and that TCDD likely increases HSC activation through a multi-faceted mechanism.

  9. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases human hepatic stellate cell activation

    PubMed Central

    Harvey, Wendy A.; Jurgensen, Kimberly; Pu, Xinzhu; Lamb, Cheri L.; Cornell, Kenneth A.; Clark, Reilly J.; Klocke, Carolyn; Mitchell, Kristen A.

    2016-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a halogenated aromatic hydrocarbon that elicits toxicity through the aryl hydrocarbon receptor (AhR). In the liver, gross markers of TCDD toxicity are attributed to AhR activation in parenchymal hepatocytes. However, less is known regarding the consequences of TCDD treatment on non-parenchymal cells in the liver. Hepatic stellate cells (HSCs) are non-parenchymal cells that store vitamin A when quiescent. Upon liver injury, activated HSCs lose this storage ability and instead function in the development and maintenance of inflammation and fibrosis through the production of pro-inflammatory mediators and collagen type I. Reports that TCDD exposure disrupts hepatic retinoid homeostasis and dysregulates extracellular matrix remodeling in the liver led us to speculate that TCDD treatment may disrupt HSC activity. The human HSC line LX-2 was used to test the hypothesis that TCDD treatment directly activates HSCs. Results indicate that exposure to 10 nM TCDD almost completely inhibited lipid droplet storage in LX-2 cells cultured with retinol and palmitic acid. TCDD treatment also increased LX-2 cell proliferation, expression of α-smooth muscle actin, and production of monocyte chemoattractant protein-1 (MCP-1), all of which are characteristics of activated HSCs. However, TCDD treatment had no effect on Col1a1 mRNA levels in LX-2 cells stimulated with the potent profibrogenic mediator, transforming growth factor-β. The TCDD-mediated increase in LX-2 cell proliferation, but not MCP-1 production, was abolished when phosphoinositide 3-kinase was inhibited. These results indicate that HSCs are susceptible to direct modulation by TCDD and that TCDD likely increases HSC activation through a multifaceted mechanism. PMID:26860701

  10. Prolactin increases hepatic Na+/taurocholate co-transport activity and messenger RNA post partum.

    PubMed Central

    Ganguly, T C; Liu, Y; Hyde, J F; Hagenbuch, B; Meier, P J; Vore, M

    1994-01-01

    We have shown that Na+/taurocholate co-transport activity is decreased in pregnancy, but rebounds post partum relative to non-pregnant controls, and that activity can be increased by treatment with ovine prolactin [Ganguly, Hyde and Vore (1993) J. Pharmacol. Exp. Ther. 267, 82-87]. To determine the basis for these effects, Na+/taurocholate co-transport was determined in purified basolateral liver plasma-membrane (bLPM) vesicles and compared with steady-state mRNA levels encoding the Na+/taurocholate-co-transporting polypeptide (Ntcp) in non-pregnant controls, pregnant rats (19-20 days pregnant), rats post partum (48 h post partum) and rats post partum treated with bromocriptine to inhibit prolactin secretion. Na+/taurocholate co-transport activity (nmol/5 s per mg of protein) in bLPM was decreased from 10.4 +/- 1.8 in non-pregnant controls to 7.9 +/- 0.6 in bLPM in pregnant rats, but rebounded to 17.5 +/- 1.3 post partum; treatment of rats post partum with bromocriptine to inhibit prolactin secretion decreased activity to 14.1 +/- 0.9. Northern and slot-blot analyses revealed similar changes in mRNA for Ntcp, so that a positive correlation was observed between Na+/taurocholate co-transport activity and Ntcp mRNA. Furthermore, treatment of ovariectomized rats with ovine prolactin increased Ntcp mRNA 10-fold compared with solvent-treated controls, consistent with the 2-fold increase in Vmax, for Na+/taurocholate co-transport in isolated hepatocytes. These data are the first to demonstrate endogenous physiological regulation by prolactin of Ntcp mRNA in parallel with Na+/taurocholate co-transport activity. Images Figure 2 PMID:7945260

  11. Increased expression of Gp96 by HBx-induced NF-κB activation feedback enhances hepatitis B virus production.

    PubMed

    Fan, Hongxia; Yan, Xiaoli; Zhang, Yu; Zhang, Xiaojun; Gao, Yanzhou; Xu, Yaxing; Wang, Fusheng; Meng, Songdong

    2013-01-01

    Elevated expression of heat shock protein gp96 in hepatitis B virus (HBV)-infected patients is positively correlated with the progress of HBV-induced diseases, but little is known regarding the molecular mechanism of virus-induced gp96 expression and its impact on HBV infection. In this study, up-regulation of gp96 by HBV replication was confirmed both in vitro and in vivo. Among HBV components, HBV x protein (HBx) was found to increase gp96 promoter activity and enhance gp96 expression by using a luciferase reporter system, and western blot analysis. Further, we found that HBx-mediated regulation of gp96 expression requires a NF-κB cis-regulatory element on the gp96 promoter, and chromatin immunoprecipitation results demonstrated that HBx promotes the binding of NF-κB to the gp96 promoter. Significantly, both gain- and loss-of-function studies showed that gp96 enhances HBV production in HBV-transfected cells and a mouse model based on hydrodynamic transfection. Moreover, up-regulated gp96 expression was observed in HBV-infected patients, and gp96 levels were correlated with serum viral loads. Thus, our work demonstrates a positive feedback regulatory pathway involving gp96 and HBV, which may contribute to persistent HBV infection. Our data also indicate that modulation of gp96 function may represent a novel strategy for the intervention of HBV infection.

  12. Pentoxifylline aggravates fatty liver in obese and diabetic ob/ob mice by increasing intestinal glucose absorption and activating hepatic lipogenesis

    PubMed Central

    Massart, J; Robin, MA; Noury, F; Fautrel, A; Lettéron, P; Bado, A; Eliat, PA; Fromenty, B

    2012-01-01

    BACKGROUND AND PURPOSE Pentoxifylline is in clinical trials for non-alcoholic fatty liver disease and diabetic nephropathy. Metabolic and hepatic effects of pentoxifylline were assessed in a murine model of obesity and type 2 diabetes. EXPERIMENTAL APPROACH Pentoxifylline (100 mg·kg−1·day−1) was administered for 4 days or 3 weeks in lean and obese/diabetic ob/ob mice. Plasma lipids, glucose, other metabolites and relevant enzymes were measured by standard assays. Hepatic lipids in vivo were assessed with magnetic resonance spectroscopy and by histology. Hepatic extracts were also analysed with RT-PCR and Western blotting. KEY RESULTS Four days of pentoxifylline treatment slightly increased liver lipids in ob/ob mice. After 3 weeks, pentoxifylline exacerbated fatty liver and plasma transaminases in ob/ob mice but did not induce liver steatosis in lean mice. Plasma glucose was highest in fed, but not fasted, ob/ob mice treated with pentoxifylline. During the first 10 min of an oral glucose tolerance test, blood glucose increased more rapidly in pentoxifylline-treated mice. Jejunal expression of glucose transporter 2 isoform was increased in pentoxifylline-treated obese mice. Hepatic activity of carbohydrate response element binding protein (ChREBP) increased after pentoxifylline in ob/ob, but not lean, mice. Hepatic expression of lipogenic enzymes was highest in pentoxifylline-treated ob/ob mice. However, pentoxifylline reduced markers of oxidative stress and inflammation in ob/ob liver. CONCLUSION AND IMPLICATIONS Pentoxifylline exacerbated fatty liver in ob/ob mice through enhanced intestinal glucose absorption, increased postprandial glycaemia and activation of hepatic lipogenesis. Long-term treatment with pentoxifylline could worsen fatty liver in some patients with pre-existing hyperglycaemia. PMID:21740407

  13. Dietary freshwater clam (Corbicula fluminea) extract suppresses accumulation of hepatic lipids and increases in serum cholesterol and aminotransferase activities induced by dietary chloretone in rats.

    PubMed

    Chijimatsu, Takeshi; Umeki, Miki; Kobayashi, Satoru; Kataoka, Yutaro; Yamada, Koji; Oda, Hiroaki; Mochizuki, Satoshi

    2015-01-01

    We investigated the ameliorative effect of freshwater clam extract (FCE) on fatty liver, hypercholesterolemia, and liver injury in rats exposed to chloretone. Furthermore, we examined the effects of major FCE components (fat and protein fractions) to determine the active components in FCE. Chloretone increased serum aminotransferase activities and led to hepatic lipid accumulation. Serum aminotransferase activities and hepatic lipid content were lower in rats fed total FCE or fat/protein fractions of FCE. Expression of fatty acid synthase and fatty acid desaturase genes was upregulated by chloretone. Total FCE and fat/protein fractions of FCE suppressed the increase in gene expression involved in fatty acid synthesis. Serum cholesterol levels increased twofold upon chloretone exposure. Total FCE or fat/protein fractions of FCE showed hypocholesterolemic effects in rats with hypercholesterolemia induced by chloretone. These suggest that FCE contains at least two active components against fatty liver, hypercholesterolemia, and liver injury in rats exposed to chloretone.

  14. Intrauterine growth restriction combined with a maternal high-fat diet increases hepatic cholesterol and low-density lipoprotein receptor activity in rats.

    PubMed

    Zinkhan, Erin K; Zalla, Jennifer M; Carpenter, Jeanette R; Yu, Baifeng; Yu, Xing; Chan, Gary; Joss-Moore, Lisa; Lane, Robert H

    2016-07-01

    Intrauterine growth restriction (IUGR) and maternal consumption of a high-saturated-fat diet (HFD) increase the risk of hypercholesterolemia, a leading cause of morbidity and mortality. Many pregnant women eat a HFD, thus exposing the fetus to a HFD in utero. The cumulative effect of in utero exposure to IUGR and a HFD on offspring cholesterol levels remains unknown. Furthermore, little is known about the mechanism through which IUGR and maternal HFD consumption increase cholesterol. We hypothesize that IUGR combined with a maternal HFD would increase offspring serum and hepatic cholesterol accumulation via alteration in levels of key proteins involved in cholesterol metabolism. To test our hypothesis we used a rat model of surgically induced IUGR and fed the dams a regular diet or a HFD HFD-fed dams consumed the same kilocalories as regular diet-fed dams, with no difference between surgical intervention groups. In the offspring, IUGR combined with a maternal HFD increased hepatic cholesterol levels, low-density lipoprotein (LDL) receptor protein levels, and Ldlr activity in female rat offspring at birth and both sexes at postnatal day 14 relative to non-IUGR offspring both from regular diet- and HFD-fed dams. These findings suggest that IUGR combined with a maternal HFD increases hepatic cholesterol accumulation via increased LDL cholesterol uptake into the liver with resulting persistent increases in hepatic cholesterol accumulation.

  15. Adenovirus-mediated transfer of a gene encoding cholesterol 7 alpha-hydroxylase into hamsters increases hepatic enzyme activity and reduces plasma total and low density lipoprotein cholesterol.

    PubMed Central

    Spady, D K; Cuthbert, J A; Willard, M N; Meidell, R S

    1995-01-01

    Clinical interventions that accelerate conversion of cholesterol to bile acids reduce circulating low density lipoprotein (LDL) cholesterol concentrations. The initial and rate-limiting step in the bile acid biosynthetic pathway is catalyzed by hepatic cholesterol 7 alpha-hydroxylase. To examine the effects of transient primary overexpression of this enzyme on sterol metabolism and lipoprotein transport, we constructed a recombinant adenovirus in which a cDNA encoding rat 7 alpha-hydroxylase is expressed from the human cytomegalovirus immediate-early promoter (AdCMV7 alpha). Syrian hamsters administered AdCMV7 alpha intravenously accumulated transgene-specific mRNA in the liver and demonstrated a dose-dependent increase in hepatic microsomal 7 alpha-hydroxylase activity. The increased conversion of cholesterol to bile acids resulted in a compensatory increase in hepatic cholesterol synthesis. In addition, overexpression of 7 alpha-hydroxylase reduced the rate of LDL cholesterol entry into the plasma space and, in animals maintained on a Western-type diet, restored hepatic LDL receptor expression. As a consequence, plasma LDL concentrations fell by approximately 60% in animals maintained on control diet and by approximately 75% in animals consuming a Western-type diet. Plasma high density lipoprotein cholesterol levels were reduced to a lesser degree. These results demonstrate that transient upregulation of bile acid synthesis by direct transfer of a 7 alpha-hydroxylase gene favorably alters circulating lipoprotein profiles and suggest one potential molecular target for genetic strategies aimed at reducing cardiovascular risk. Images PMID:7635963

  16. Pharmacokinetics of 5-fluorouracil and increased hepatic dihydropyrimidine dehydrogenase activity levels in 1,2-dimethylhydrazine-induced colorectal cancer model rats.

    PubMed

    Kobuchi, Shinji; Ito, Yukako; Okada, Kae; Imoto, Kazuki; Takada, Kanji

    2013-09-01

    To investigate the hepatic dihydropyrimidine dehydrogenase (DPD) activity in colorectal cancer (CRC), which is critically important to create a patient-specific dosing regimen, we performed 5-FU pharmacokinetic studies in 1,2-dimethylhydrazine-induced CRC model rats (CRC rats). After rats received 5-FU intravenous (IV) bolus injections, the area under the plasma concentration-time curve (AUC) and elimination half-life (t 1/2) in CRC rats (10.02 ± 0.37 μg h mL(-1), 0.30 ± 0.02 h, respectively) were significantly lower than that in control rats (13.46 ± 1.20 μg h mL(-1), 0.52 ± 0.05 h, respectively), whereas total plasma clearance (CLtot) in CRC rats (2.01 ± 0.07 L h(-1) kg(-1)) was significantly increased compared with that in control rats (1.54 ± 0.14 L h(-1) kg(-1)). Conversely, the avoidance ratio of the hepatic first-pass effect was approximately 20 % lower than that in control rats. Of interest is that hepatic DPD activity levels and the dihydrouracil-uracil ratio (UH2/Ura ratio) in plasma, which may act as a potential biomarker to evaluate hepatic DPD activity levels, were significantly increased in CRC rats. These results suggest that the decrease of hepatic availability in CRC rats is brought about by the increase in intrinsic clearance induced by the increase in DPD activity, resulting in a decrease in AUC and t 1/2 and an increase in CLtot after 5-FU IV bolus injection. Along with a proper dosing regimen for patients with CRC, a hepatic DPD activity monitoring system, such as the determination of UH2/Ura ratio in plasma, is desirable.

  17. [The morphologic basis for the mechanism of increased serum acid phosphatase activity in patients with viral hepatitis].

    PubMed

    Drozd, T N; Luchshev, V I; Zaĭtsev, V V; Berezina, T A

    1975-01-01

    The activity of acid phosphotase in the blood serum and punctates of the liver was studied in 49 patients with acute cyclic form of viral hepatitis of slight and medium-grave course with the use of histological and histochemical methods. The degree of manifestation of necrotic changes in the punctate tissue was determined with the help of the stereometric method. As a result of the studies conducted, it was established that the degree of hyperfermentemia was the highest at the period when the disease was in full swing, and that it did not depend on the form of its course and extent of necrotic changes observed in the liver punctates. The authors consider a morphological evidence of high activity of acid phosphotase in the blood serum aggregations of large hepatocytes, cytoplasm of which was loaded with mature lipofuscin, the topographic identity of the latter with acid phosphotase at present being proved.

  18. Increased hepatic oxidative metabolism distinguishes the action of Peroxisome proliferator-activated receptor δ from Peroxisome proliferator-activated receptor γ in the ob/ob mouse

    PubMed Central

    2009-01-01

    Background The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors and members of the nuclear receptor superfamily. The PPAR family consists of three members: PPARα, PPARγ, and PPARδ. PPARδ controls the transcription of genes involved in multiple physiological pathways, including cellular differentiation, lipid metabolism and energy homeostasis. The receptor is expressed almost ubiquitously, with high expression in liver and skeletal muscle. Although the physiological ligands of PPARδ remain undefined, a number of high affinity synthetic ligands have been developed for the receptor as a therapeutic target for type 2 diabetes mellitus, dyslipidemia and the metabolic syndrome. Methods In this study, the metabolic role of PPARδ activation has been investigated in liver, skeletal muscle, blood serum and white adipose tissue from ob/ob mice using a high affinity synthetic ligand and contrasted with PPARγ activation. To maximize the analytical coverage of the metabolome, 1H-nuclear magnetic resonance (1H-NMR) spectroscopy, gas chromatography-mass spectrometry (GC-MS) and ultra performance liquid chromatography-mass spectrometry (UPLC-MS) were used to examine metabolites from tissue extracts. Results Analysis by multivariate statistics demonstrated that PPARδ activation profoundly affected glycolysis, gluconeogenesis, the TCA cycle and linoleic acid and α-linolenic acid essential fatty acid pathways. Conclusions Although activation of both PPARδ and PPARγ lead to increased insulin sensitivity and glucose tolerance, PPARδ activation was functionally distinct from PPARγ activation, and was characterized by increased hepatic and peripheral fatty acid oxidative metabolism, demonstrating the distinctive catabolic role of this receptor compared with PPARγ. PMID:19968882

  19. St. John's Wort increases brain serotonin synthesis by inhibiting hepatic tryptophan 2, 3 dioxygenase activity and its gene expression in stressed rats.

    PubMed

    Bano, Samina; Ara, Iffat; Saboohi, Kausar; Moattar, Tariq; Chaoudhry, Bushra

    2014-09-01

    We aimed to investigate the effects of herbal St. John's Wort (SJW) on transcriptional regulation of hepatic tryptophan 2, 3 - dioxygenase (TDO) enzyme activity and brain regional serotonin (5-HT) levels in rats exposed to forced swim test (FST). TDO mRNA expression was quantified using real-time reverse transcription polymerase chain (RT-PCR) reaction and brain regional indoleamines were determined by high performance liquid chromatography coupled to fluorescence detector. Behavioral analysis shows significant reduction in immobility time in SJW (500mg/kg/ml) administered rats. It was found that pretreatment of SJW to rats did not prevent stress-induced elevation in plasma corticosterone levels however it increases serotonin synthesis by virtue of inhibiting hepatic TDO enzyme activity and its gene expression, ascertaining the notion that there exists an inverse relationship between hepatic TDO enzyme activity and brain 5-HT. The drug also decreases serotonin turnover in all the brain areas (hypothalamus, hippocampus amygdala) in stressed rats endorsing its monoamine oxidase inhibition property. Inhibition of TDO enzyme activity and its gene expression by the drug provides new insights for the development of therapeutic interventions for stress related mental illnesses.

  20. Hyperoxia increases hepatic arginase expression and ornithine production in mice

    SciTech Connect

    Malleske, Daniel T.; Rogers, Lynette K.; Velluci, Sean M.; Young, Tamara L.; Park, Min S.; Long, Donald W.; Welty, Stephen E.; Smith, Charles V.; Nelin, Leif D. . E-mail: NelinL@pediatrics.ohio-state.edu

    2006-08-15

    Hyperoxic exposure affects the levels and activities of some hepatic proteins. We tested the hypothesis that hyperoxic exposure would result in greater hepatic .NO concentrations. C3H/HeN mice were exposed to >95% O{sub 2} for 72 or 96 h and compared to room air-breathing controls. In contrast to our working hypothesis, exposure to >95% O{sub 2} for 96 h decreased hepatic nitrite/nitrate NO {sub X} concentrations (10.9 {+-} 2.2 nmol/g liver versus 19.3 {+-} 2.4 nmol/g liver in room air, P < 0.05). The hepatic levels of endothelial NO synthase (eNOS) and inducible NOS (iNOS) proteins were not different among the groups. The arginases, which convert L-arginine to urea and L-ornithine, may affect hepatic NOS activities by decreasing L-arginine bioavailability. Hepatic ornithine concentrations were greater in hyperoxic animals than in controls (318 {+-} 18 nmol/g liver in room air, and 539 {+-} 64, and 475 {+-} 40 at 72 and 96 h of hyperoxia, respectively, P < 0.01). Hepatic arginase I protein levels were greater in hyperoxic animals than in controls. Hepatic carbamoyl phosphate synthetase (CPS) protein levels and activities were not different among groups. These results indicate that increases in hepatic levels of arginase I in mice exposed to hyperoxia may diminish .NO production, as reflected by lower liver levels of NO {sub X}. The resultant greater hepatic ornithine concentrations may represent a mechanism to facilitate tissue repair, by favoring the production of polyamines and/or proline.

  1. Alcoholic hepatitis accelerates early hepatobiliary cancer by increasing stemness and miR-122-mediated HIF-1α activation

    PubMed Central

    Ambade, Aditya; Satishchandran, Abhishek; Szabo, Gyongyi

    2016-01-01

    Alcohol-related hepatocellular carcinoma (HCC) develops with advanced alcoholic liver disease and liver fibrosis. Using adult mice, we evaluate the effect of alcoholic steatohepatitis on early hepatobiliary carcinoma after initiation by diethyl-nitrosamine (DEN). Here we show that alcohol-fed DEN-injected mice have higher ALT and liver-to-body weight ratio compared to pair-fed DEN-injected mice. Alcohol feeding results in steatohepatitis indicated by increased pro-inflammatory cytokines and fibrotic genes. MRI and liver histology of alcohol+DEN mice shows hepatobiliary cysts, early hepatic neoplasia and increase in serum alpha-fetoprotein. Proliferation makers (BrdU, cyclin D1, p53) and cancer stem cell markers (CD133 and nanog) are significantly up-regulated in livers of alcohol-fed DEN-injected mice compared to controls. In livers with tumors, loss of miR-122 expression with a significant up-regulation of miR-122 target HIF-1α is seen. We conclude that alcoholic steatohepatitis accelerates hepatobiliary tumors with characteristic molecular features of HCC by up-regulating inflammation, cell proliferation, stemness, and miR-122 loss. PMID:26888602

  2. Phosphorylation of hepatic AMP-activated protein kinase and liver kinase B1 is increased after a single oral dose of green tea extract to mice.

    PubMed

    Banerjee, Subhashis; Ghoshal, Sarbani; Porter, Todd D

    2012-12-01

    We have previously shown that green and black tea extracts increase the phosphorylation of AMP-activated protein kinase (AMPK) and HMG-CoA reductase in rat hepatoma cells in culture, concomitant with a decrease in cholesterol synthesis. In the present study, we evaluated the ability of a single oral dose of green or black tea extract to promote the phosphorylation of AMPK, liver kinase B1 (LKB1, an AMPK-kinase), and HMG-CoA reductase in mouse liver. Green tea extract administered by gavage at 50 and 100 mg/kg caused a 2- to 3-fold increase in hepatic AMPK phosphorylation at 3 and 6 hours after dosing and a 1.5- to 2-fold increase in LKB1 phosphorylation at these same time points. The phosphorylation of HMG-CoA reductase at these and later time points was not significantly increased. Black tea administered by gavage at up to 250 mg/kg was ineffective in increasing hepatic AMPK phosphorylation. Both green and black tea extracts increased LKB1 phosphorylation in hepatoma cells in culture at 15 μg/mL, and black tea also increased the phosphorylation of protein kinase A in hepatoma cells. These results suggest that compounds in both tea extracts activate AMPK by activating its upstream kinase, LKB1, and that black tea may do so by first activating protein kinase A, a known kinase for LKB1. Only green tea, at 50 and 100 mg/kg, was able to activate AMPK and LKB1 in mouse liver after oral dosing, suggesting that the polymerized catechins present in black tea do not reach the liver in sufficient concentration to affect AMPK activity.

  3. The expression of HIV-1 Vpu in monocytes causes increased secretion of TGF-β that activates profibrogenic genes in hepatic stellate cells.

    PubMed

    Patel, Paresh; Khan, Nabab; Rani, Manjusha; Gupta, Deepti; Jameel, Shahid

    2014-01-01

    There is faster progression to fibrosis in persons with liver injury who are also infected with HIV. Other reports have suggested that HIV can directly infect and activate stellate cells, and the viral Tat and gp160 proteins also induce profibrogenic factors from peripheral blood mononuclear cells (PBMCs). We tested the role of HIV-1 Vpu accessory protein in promoting profibrogenic activation of hepatic stellate cells. Human stellate LX2 cells were cocultured with human monocytic U937 cells stably expressing the Vpu protein or latently infected U1 cells knocked down for Vpu expression, LX2 cells were also cultured with the supernatants from these cells. The expression of profibrogenic markers was evaluated in LX2 cells usingquantitative reverse transcription polymerase chain reaction (qRT-PCR),western blotting, immunofluorescence,flow cytometry and ELISA were used to confirm and quantitate protein expression. Monocytic cells expressing Vpu increased the expression of profibrogenic markers in LX2 cells. The culture supernatants of these cells contained increased levels of transforming growth factor beta (TGF-β), which correlated with increased activity of the AP-1 transcription factor. Antibodies against TGF-β or a TGF-β receptor inhibitor (SB431452) reversed Vpu-mediated profibrogenic activation of LX2 cells, suggesting that TGF-β mediated these effects. The cytokine macrophage migration inhibitory factor (MIF) attenuated Vpu-mediated TGF-β secretion and profibrogenic effects on LX2 cells. Besides its other roles in pathogenesis, Vpu is likely to contribute to hepatic fibrosis through this hitherto unknown mechanism.

  4. (+)-Catechin attenuates activation of hepatic stellate cells.

    PubMed

    Bragança de Moraes, Cristina Machado; Bitencourt, Shanna; de Mesquita, Fernanda Cristina; Mello, Denizar; de Oliveira, Leticia Paranhos; da Silva, Gabriela Viegas; Lorini, Vinicius; Caberlon, Eduardo; de Souza Basso, Bruno; Schmid, Julia; Ferreira, Gabriela Acevedo; de Oliveira, Jarbas Rodrigues

    2014-04-01

    (+)-Catechin is a type of catechin present in large amounts in açaí fruits and cocoa seeds. Besides its antioxidant and anti-inflammatory activities, little is known about its effects in the liver, especially during hepatic fibrosis. We report here the effects of (+)-catechin on hepatic stellate cells. (+)-Catechin induced quiescent phenotype in GRX cells, along with an increase in lipid droplets. Proliferator-activated receptor γ mRNA expression was upregulated, whereas type I collagen mRNA expression was downregulated. Pro-inflammatory cytokines were not influenced by (+)-catechin, whereas the levels of interleukin 10 were significantly increased. The data provide evidence that (+)-catechin can reduce hepatic stellate cell activation.

  5. Lung and liver injury following hepatic ischemia/reperfusion in the rat is increased by exogenous lipopolysaccharide which also increases hepatic TNF production in vivo and in vitro.

    PubMed

    Colletti, L M; Green, M

    2001-10-01

    Hepatic ischemia/reperfusion (I/R) results in tumor necrosis factor (TNF) release. Kupffer cells (KC) are one source of this TNF. This study investigates the effects of hepatic I/R combined with lipopolysaccharide (LPS) on the lung and liver injury that follow hepatic I/R and on hepatic release of TNF, epithelial neutrophil activating protein (ENA-78), and macrophage inflammatory protein-2 (MIP-2). The effects of these experimental conditions on TNF production by primary rat KC in vitro were also investigated. Rats were subjected to hepatic I/R alone, hepatic I/R + LPS, sham laparotomy alone, or sham laparotomy + LPS and pulmonary MPO, pulmonary microvascular permeability, hepatic neutrophil influx, hepatic injury, and hepatic TNF, ENA-78, and MIP-2 production were measured. These experiments demonstrated that hepatic I/R in conjunction with LPS results in a more severe lung and liver injury and increased hepatic TNF, ENA-78, and MIP-2 release. The effects of these experimental conditions on rat KC TNF production demonstrated that hepatic I/R + LPS results in a more significant release of TNF as compared to LPS alone or I/R alone. Hepatic I/R plus LPS results in a more severe lung and liver injury and is likely secondary to a more significant and prolonged release of TNF by KC. This may provide a mechanism for development of multiple organ system failure in some patients undergoing hepatic resection, hepatic transplantation, complex vascular operations, or in the setting of hypovolemic shock. Portal endotoxemia related to mesenteric venous congestion or other systemic insults may have a significant impact on post-operative complications and recovery in the setting of a local or global hepatic I/R injury.

  6. Hepatitis B virus X protein induces RNA polymerase III-dependent gene transcription and increases cellular TATA-binding protein by activating the Ras signaling pathway.

    PubMed

    Wang, H D; Trivedi, A; Johnson, D L

    1997-12-01

    Our previous studies have shown that the hepatitis B virus protein, X, activates all three classes of RNA polymerase III (pol III)-dependent promoters by increasing the cellular level of TATA-binding protein (TBP) (H.-D. Wang et al., Mol. Cell. Biol. 15:6720-6728, 1995), a limiting transcription component (A. Trivedi et al., Mol. Cell. Biol. 16:6909-6916, 1996). We have investigated whether these X-mediated events are dependent on the activation of the Ras/Raf-1 signaling pathway. Transient expression of a dominant-negative mutant Ras gene (Ras-ala15) in a Drosophila S-2 stable cell line expressing X (X-S2), or incubation of the cells with a Ras farnesylation inhibitor, specifically blocked both the X-dependent activation of a cotransfected tRNA gene and the increase in cellular TBP levels. Transient expression of a constitutively activated form of Ras (Ras-val12) in control S2 cells produced both an increase in tRNA gene transcription and an increase in cellular TBP levels. These events are not cell type specific since X-mediated gene induction was also shown to be dependent on Ras activation in a stable rat 1A cell line expressing X. Furthermore, increases in RNA pol III-dependent gene activity and TBP levels could be restored in X-S2 cells expressing Ras-ala15 by coexpressing a constitutively activated form of Raf-1. These events are serum dependent, and when the cells are serum deprived, the X-mediated effects are augmented. Together, these results demonstrate that the X-mediated induction of RNA pol III-dependent genes and increase in TBP are both dependent on the activation of the Ras/Raf-1 signaling cascade. In addition, these studies define two new and important consequences mediated by the activation of the Ras signal transduction pathway: an increase in the central transcription factor, TBP, and the induction of RNA pol III-dependent gene activity.

  7. Deubiquitylation of hepatitis B virus X protein (HBx) by ubiquitin-specific peptidase 15 (USP15) increases HBx stability and its transactivation activity

    PubMed Central

    Su, Zhi-Jun; Cao, Jia-Shou; Wu, Yan-Fang; Chen, Wan-Nan; Lin, Xinjian; Wu, Yun-Li; Lin, Xu

    2017-01-01

    Hepatitis B virus X protein (HBx) plays important roles in viral replication and the development of hepatocellular carcinoma. HBx is a rapid turnover protein and ubiquitin-proteasome pathway has been suggested to influence HBx stability as treatment with proteasome inhibitors increases the levels of HBx protein and causes accumulation of the polyubiquitinated forms of HBx. Deubiquitinases (DUBs) are known to act by removing ubiquitin moieties from proteins and thereby reverse their stability and/or activity. However, no information is available regarding the involvement of DUBs in regulation of ubiquitylation-dependent proteasomal degradation of HBx protein. This study identified the deubiquitylating enzyme USP15 as a critical regulator of HBx protein level. USP15 was found to directly interact with HBx via binding to the HBx region between amino acid residues 51 and 80. USP15 increased HBx protein levels in a dose-dependent manner and siRNA-mediated knockdown of endogenous USP15 reduced HBx protein levels. Increased HBx stability and steady-state level by USP15 were attributable to reduced HBx ubiquitination and proteasomal degradation. Importantly, the transcriptional transactivation function of HBx is enhanced by overexpression of USP15. These results suggest that USP15 plays an essential role in stabilizing HBx and subsequently affects the biological function of HBx. PMID:28074857

  8. Hepatic stellate cells increase the immunosuppressive function of natural Foxp3+ regulatory T cells via IDO-induced AhR activation.

    PubMed

    Kumar, Sudhir; Wang, Jiang; Thomson, Angus W; Gandhi, Chandrashekhar R

    2017-02-01

    Immunosuppressive, naturally occurring CD4(+)CD25(+)forkhead box p3(+) (Foxp3(+)) regulatory T cells (nTregs) offer potential for the treatment of immune-mediated inflammatory disorders. However, potential instability of ex vivo-expanded nTregs following their adoptive transfer may be a significant limitation. LPS-stimulated hepatic stellate cells (HSCs) induce expansion and enhance the suppressive function and stability of allogeneic nTregs We aimed to delineate mechanisms underlying HSC-induced expansion and increased potency of nTregs HSCs and nTregs were isolated from mouse livers and spleens, respectively. Following coculture with LPS-pretreated allogeneic HSCs (LPS/HSCs), proliferation of nTregs was measured by CFSE dilution, and Foxp3 expression and acetylation were determined by immunoprecipitation (IP) and Western blotting analysis. Expression of various genes associated with immunologic tolerance was determined by quantitative RT-PCR (qRT-PCR). LPS stimulation increased the expression and activity of the immunoregulatory enzyme IDO1 in HSCs, and LPS/HSCs stimulated aryl hydrocarbon receptor (AhR) signaling in cocultured nTregs Reciprocally, Tregs increased IDO1 expression in HSCs. IDO1(-/-) LPS/HSCs were inferior to WT LPS/HSCs in stimulating nTreg expansion. Pharmacologic inhibition of IDO1 in HSCs by 1-methyltryptophan (1MT) inhibited LPS/HSC-induced AhR signaling in nTregs, which was responsible for their expansion, Foxp3 expression, and stabilization of Foxp3 by increasing acetylation of lysine residues. Finally, HSCs cryopreserved, following 2-3 passages, were as potent as primary-cultured HSCs in expanding nTregs In conclusion, LPS/HSCs expand allogeneic nTregs through an IDO-dependent, AhR-mediated mechanism and increase their stability through lysine-acetylation of Foxp3. nTregs expanded by cryopreserved HSCs may have potential for clinical use.

  9. IRE1α-XBP1s induces PDI expression to increase MTP activity for hepatic VLDL assembly and lipid homeostasis.

    PubMed

    Wang, Shiyu; Chen, Zhouji; Lam, Vivian; Han, Jaeseok; Hassler, Justin; Finck, Brian N; Davidson, Nicholas O; Kaufman, Randal J

    2012-10-03

    The unfolded protein response (UPR) is a signaling pathway required to maintain endoplasmic reticulum (ER) homeostasis and hepatic lipid metabolism. Here, we identify an essential role for the inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α)-X box binding protein 1 (XBP1) arm of the UPR in regulation of hepatic very low-density lipoprotein (VLDL) assembly and secretion. Hepatocyte-specific deletion of Ire1α reduces lipid partitioning into the ER lumen and impairs the assembly of triglyceride (TG)-rich VLDL but does not affect TG synthesis, de novo lipogenesis, or the synthesis or secretion of apolipoprotein B (apoB). The defect in VLDL assembly is, at least in part, due to decreased microsomal triglyceride-transfer protein (MTP) activity resulting from reduced protein disulfide isomerase (PDI) expression. Collectively, our findings reveal a key role for the IRE1α-XBP1s-PDI axis in linking ER homeostasis with regulation of VLDL production and hepatic lipid homeostasis that may provide a therapeutic target for disorders of lipid metabolism.

  10. Inhibition of diethylnitrosamine-initiated alcohol-promoted hepatic inflammation and precancerous lesions by flavonoid luteolin is associated with increased sirtuin 1 activity in mice

    PubMed Central

    Rafacho, Bruna Paola Murino; Stice, Camilla Peach; Liu, Chun; Greenberg, Andrew S.; Ausman, Lynne M.

    2015-01-01

    Background Chronic and excessive alcohol consumption is an established risk for hepatic inflammation and carcinogenesis. Luteolin is one of the most common flavonoids present in plants and has potential beneficial effects against cancer. In this study, we examined the effect and potential mechanisms of luteolin supplementation in a carcinogen initiated alcohol-promoted pre-neoplastic liver lesion mouse model. Methods C57BL/6 mice were injected with diethylnitrosamine (DEN) [i.p. 25 mg/kg of body weight (BW)] at 14 days of age. At 8 weeks of age mice were group pair-fed with Lieber-DeCarli liquid control diet or alcoholic diet [ethanol (EtOH) diet, 27% total energy from ethanol] and supplemented with a dose of 30 mg luteolin/kg BW per day for 21 days. Results DEN-injected mice fed EtOH diet displayed a significant induction of pre-neoplastic lesions, a marker associated with presence of steatosis and inflammation. Dietary luteolin significantly reduced the severity and incidence of hepatic inflammatory foci and steatosis in DEN-injected mice fed EtOH diet, as well the presence of preneoplastic lesions. There was no difference on hepatic protein levels of sirtuin 1 (SIRT1) among all groups; however, luteolin supplementation significantly reversed alcohol-reduced SIRT1 activity assessed by the ratio of acetylated and total forkhead box protein O1 (FoXO1) and SIRT1 target proliferator-activated receptor gamma, coactivator 1 alpha (PGC1α). Conclusions Dietary intake of luteolin prevents alcohol promoted pre-neoplastic lesions, potentially mediated by SIRT1 signaling pathway. PMID:26005679

  11. Studies on immunoproteasome in human liver. Part I: Absence in fetuses, presence in normal subjects, and increased levels in chronic active hepatitis and cirrhosis

    SciTech Connect

    Vasuri, Francesco; Capizzi, Elisa; Bellavista, Elena; Mishto, Michele; Santoro, Aurelia; Fiorentino, Michelangelo; Capri, Miriam; Cescon, Matteo; Grazi, Gian Luca; Grigioni, Walter Franco; D'Errico-Grigioni, Antonia; Franceschi, Claudio

    2010-06-25

    Despite the central role of proteasomes in relevant physiological pathways and pathological processes, this topic is unexpectedly largely unexplored in human liver. Here we present data on the presence of proteasome and immunoproteasome in human livers from normal adults, fetuses and patients affected by major hepatic diseases such as cirrhosis and chronic active hepatitis. Immunohistochemistry for constitutive ({alpha}4 and {beta}1) and inducible (LMP2 and LMP7) proteasome subunits, and for the PA28{alpha}{beta} regulator, was performed in liver samples from 38 normal subjects, 6 fetuses, 2 pediatric cases, and 19 pathological cases (10 chronic active hepatitis and 9 cirrhosis). The immunohistochemical data have been validated and quantified by Western blotting analysis. The most striking result we found was the concomitant presence in hepatocyte cytoplasm of all healthy subjects, including the pediatric cases, of constitutive proteasome and immunoproteasome subunits, as well as PA28{alpha}{beta}. At variance, immunoproteasome was not present in hepatocytes from fetuses, while a strong cytoplasmic and nuclear positivity for LMP2 and LMP7 was found in pathological samples, directly correlated to the histopathological grade of inflammation. At variance from other organs such as the brain, immunoproteasome is present in livers from normal adult and pediatric cases, in apparent absence of pathological processes, suggesting the presence of a peculiar regulation of the proteasome/immunoproteasome system, likely related to the physiological stimuli derived from the gut microbiota after birth. Other inflammatory stimuli contribute in inducing high levels of immunoproteasome in pathological conditions, where its role deserve further attention.

  12. Thyroid stimulating hormone increases hepatic gluconeogenesis via CRTC2.

    PubMed

    Li, Yujie; Wang, Laicheng; Zhou, Lingyan; Song, Yongfeng; Ma, Shizhan; Yu, Chunxiao; Zhao, Jiajun; Xu, Chao; Gao, Ling

    2017-02-15

    Epidemiological evidence indicates that thyroid stimulating hormone (TSH) is positively correlated with abnormal glucose levels. We previously reported that TSH has direct effects on gluconeogenesis. However, the underlying molecular mechanism remains unclear. In this study, we observed increased fasting blood glucose and glucose production in a mouse model of subclinical hypothyroidism (only elevated TSH levels). TSH acts via the classical cAMP/PKA pathway and CRTC2 regulates glucose homeostasis. Thus, we explore whether CRTC2 is involved in the process of TSH-induced gluconeogenesis. We show that TSH increases CRTC2 expression via the TSHR/cAMP/PKA pathway, which in turn upregulates hepatic gluconeogenic genes. Furthermore, TSH stimulates CRTC2 dephosphorylation and upregulates p-CREB (Ser133) in HepG2 cells. Silencing CRTC2 and CREB decreases the effect of TSH on PEPCK-luciferase, the rate-limiting enzyme of gluconeogenesis. Finally, the deletion of TSHR reduces the levels of the CRTC2:CREB complex in mouse livers. This study demonstrates that TSH activates CRTC2 via the TSHR/cAMP/PKA pathway, leading to the formation of a CRTC2:CREB complex and increases hepatic gluconeogenesis.

  13. Pharmacological Intervention in Hepatic Stellate Cell Activation and Hepatic Fibrosis

    PubMed Central

    Schon, Hans-Theo; Bartneck, Matthias; Borkham-Kamphorst, Erawan; Nattermann, Jacob; Lammers, Twan; Tacke, Frank; Weiskirchen, Ralf

    2016-01-01

    The activation and transdifferentiation of hepatic stellate cells (HSCs) into contractile, matrix-producing myofibroblasts (MFBs) are central events in hepatic fibrogenesis. These processes are driven by autocrine- and paracrine-acting soluble factors (i.e., cytokines and chemokines). Proof-of-concept studies of the last decades have shown that both the deactivation and removal of hepatic MFBs as well as antagonizing profibrogenic factors are in principle suitable to attenuate ongoing hepatic fibrosis. Although several drugs show potent antifibrotic activities in experimental models of hepatic fibrosis, there is presently no effective pharmaceutical intervention specifically approved for the treatment of liver fibrosis. Pharmaceutical interventions are generally hampered by insufficient supply of drugs to the diseased liver tissue and/or by adverse effects as a result of affecting non-target cells. Therefore, targeted delivery systems that bind specifically to receptors solely expressed on activated HSCs or transdifferentiated MFBs and delivery systems that can improve drug distribution to the liver in general are urgently needed. In this review, we summarize current strategies for targeted delivery of drugs to the liver and in particular to pro-fibrogenic liver cells. The applicability and efficacy of sequestering molecules, selective protein carriers, lipid-based drug vehicles, viral vectors, transcriptional targeting approaches, therapeutic liver- and HSC-specific nanoparticles, and miRNA-based strategies are discussed. Some of these delivery systems that had already been successfully tested in experimental animal models of ongoing hepatic fibrogenesis are expected to translate into clinically useful therapeutics specifically targeting HSCs. PMID:26941644

  14. Endozepine-4 levels are increased in hepatic coma

    PubMed Central

    Malaguarnera, Giulia; Vacante, Marco; Drago, Filippo; Bertino, Gaetano; Motta, Massimo; Giordano, Maria; Malaguarnera, Michele

    2015-01-01

    AIM: To evaluate the serum levels of endozepine-4, their relation with ammonia serum levels, the grading of coma and the severity of cirrhosis, in patients with hepatic coma. METHODS: In this study we included 20 subjects with Hepatic coma, 20 subjects with minimal hepatic encephalopathy (MHE) and 20 subjects control. All subjects underwent blood analysis, Child Pugh and Model for End - stage liver disease (MELD) assessment, endozepine-4 analysis. RESULTS: Subjects with hepatic coma showed significant difference in endozepine-4 (P < 0.001) and NH3 levels (P < 0.001) compared both to MHE and controls patients. Between NH3 and endozepine-4 we observed a significant correlation (P = 0.009; Pearson correlation 0.570). There was a significant correlation between endozepine-4 and MELD (P = 0.017; Pearson correlation = 0.529). In our study blood ammonia concentration was noted to be raised in patients with hepatic coma, with the highest ammonia levels being found in those who were comatose. We also found a high correlation between endozepine-4 and ammonia (P < 0.001). In patients with grade IV hepatic coma, endozepine levels were significantly higher compared to other groups. CONCLUSION: This study suggests that an increased level of endozepine in subjects with higher levels of MELD was observed. In conclusion, data concerning involvement of the GABA-ergic system in HE coma could be explained by stage-specific alterations. PMID:26290636

  15. Increase of hepatic fat accumulation by liver specific expression of Hepatitis B virus X protein in zebrafish.

    PubMed

    Shieh, Yun-Sheng; Chang, Yin-Shan; Hong, Jiann-Ruey; Chen, Li-Je; Jou, Luen-Kuang; Hsu, Chia-Chun; Her, Guor Mour

    2010-07-01

    The pathogenesis of fatty liver disease remains largely unknown. Here, we assessed the importance of hepatic fat accumulation on the progression of hepatitis in zebrafish by liver specific expression of Hepatitis B virus X protein (HBx). Transgenic zebrafish lines, GBXs, which selectively express the GBx transgene (GFP-fused HBx gene) in liver, were established. GBX Liver phenotypes were evaluated by histopathology and molecular analysis of fatty acid (FA) metabolism-related genes expression. Most GBXs (66-81%) displayed obvious emaciation starting at 4 months old. Over 99% of the emaciated GBXs developed hepatic steatosis or steatohepatitis, which in turn led to liver hypoplasia. The liver histology of GBXs displayed steatosis, lobular inflammation, and balloon degeneration, similar to non-alcoholic steatohepatitis (NASH). Oil red O stain detected the accumulation of fatty droplets in GBXs. RT-PCR and Q-rt-PCR analysis revealed that GBx induced hepatic steatosis had significant increases in the expression of lipogenic genes, C/EBP-alpha, SREBP1, ChREBP and PPAR-gamma, which then activate key enzymes of the de novo FA synthesis, ACC1, FAS, SCD1, AGAPT, PAP and DGAT2. In addition, the steatohepatitic GBX liver progressed to liver degeneration and exhibited significant differential gene expression in apoptosis and stress. The GBX models exhibited both the genetic and functional factors involved in lipid accumulation and steatosis-associated liver injury. In addition, GBXs with transmissible NASH-like phenotypes provide a promising model for studying liver disease.

  16. Catalase ameliorates hepatic fibrosis by inhibition of hepatic stellate cells activation.

    PubMed

    Dong, Yuwei; Qu, Ying; Xu, Mingyi; Wang, Xingpeng; Lu, Lungen

    2014-01-01

    Catalase, an endogenous antioxidant enzyme, is thought to have rescue effects on hepatic fibrosis. In this study, the regulation of catalase in CCl₄-induced hepatic fibrogenesis was investigated. Our results indicated that catalase expression was decreased upon CCl₄ treatment in a time-dependent manner, while the expression of several profibrosis and proangiogenic factors, including transforming growth factor (TGF)-beta 1, vascular endothelial growth factor (VEGF), and angiopoietin 1 were significantly increased. To assess the role of catalase in hepatic fibrosis, catalase was overexpressed in HSC-T6 cells. This overexpression resulted in the inhibition of cell proliferation, migratory activity, and alpha-smooth muscle actin (alpha-SMA) expression, key features that characterize activation of hepatic stellate cells (HSC). Overexpression of catalase led to a decrease in the secretion of collagen type 1 and angiopoietin 1. These results indicate that loss of catalase activity is involved in the pathogenesis of hepatic fibrosis caused by the activation of HSCs.

  17. Hepatitis B virus X protein regulates hepatic glucose homeostasis via activation of inducible nitric oxide synthase.

    PubMed

    Shin, Hye-Jun; Park, Young-Ho; Kim, Sun-Uk; Moon, Hyung-Bae; Park, Do Sim; Han, Ying-Hao; Lee, Chul-Ho; Lee, Dong-Seok; Song, In-Sung; Lee, Dae Ho; Kim, Minhye; Kim, Nam-Soon; Kim, Dae-Ghon; Kim, Jin-Man; Kim, Sang-Keun; Kim, Yo Na; Kim, Su Sung; Choi, Cheol Soo; Kim, Young-Bum; Yu, Dae-Yeul

    2011-08-26

    Dysregulation of liver functions leads to insulin resistance causing type 2 diabetes mellitus and is often found in chronic liver diseases. However, the mechanisms of hepatic dysfunction leading to hepatic metabolic disorder are still poorly understood in chronic liver diseases. The current work investigated the role of hepatitis B virus X protein (HBx) in regulating glucose metabolism. We studied HBx-overexpressing (HBxTg) mice and HBxTg mice lacking inducible nitric oxide synthase (iNOS). Here we show that gene expressions of the key gluconeogenic enzymes were significantly increased in HepG2 cells expressing HBx (HepG2-HBx) and in non-tumor liver tissues of hepatitis B virus patients with high levels of HBx expression. In the liver of HBxTg mice, the expressions of gluconeogenic genes were also elevated, leading to hyperglycemia by increasing hepatic glucose production. However, this effect was insufficient to cause systemic insulin resistance. Importantly, the actions of HBx on hepatic glucose metabolism are thought to be mediated via iNOS signaling, as evidenced by the fact that deficiency of iNOS restored HBx-induced hyperglycemia by suppressing the gene expression of gluconeogenic enzymes. Treatment of HepG2-HBx cells with nitric oxide (NO) caused a significant increase in the expression of gluconeogenic genes, but JNK1 inhibition was completely normalized. Furthermore, hyperactivation of JNK1 in the liver of HBxTg mice was also suppressed in the absence of iNOS, indicating the critical role for JNK in the mutual regulation of HBx- and iNOS-mediated glucose metabolism. These findings establish a novel mechanism of HBx-driven hepatic metabolic disorder that is modulated by iNOS-mediated activation of JNK.

  18. Increased tumour necrosis factor alpha production by neutrophils in patients with hepatitis B.

    PubMed Central

    Fan, X; Zhang, Z

    1994-01-01

    AIMS--To investigate the role of serum and neutrophil tumour necrosis factor alpha (TNF alpha) in patients with viral hepatitis. METHODS--The activities of serum and neutrophil TNF alpha were measured using a bioassay of in vitro cytotoxicity against L929 cells in 57 patients with viral hepatitis and 20 healthy blood donors. RESULTS--Both serum and neutrophil TNF alpha in patients with chronic active hepatitis (CAH) and subacute fulminant hepatitis (SAFH) increased compared with those in normal controls (p < 0.01). No such differences were seen in patients with acute hepatitis. Serum and neutrophil TNF alpha were obviously reduced in patients with CAH and SAFH during convalescence compared with the active period (p < 0.05; p < 0.01). Furthermore, serum TNF alpha was significantly increased in patients with SAFH and complications compared with those without (p < 0.01), and in patients with SAFH who died compared with those who survived (p < 0.01). Neutrophil TNF alpha was significantly higher in patients with SAFH and secondary bacterial infections (p < 0.05). CONCLUSIONS--Production of serum and neutrophil TNF alpha is increased in patients with CAH and SAFH, suggesting that neutrophil TNF alpha causes liver injury in these patients. PMID:8089217

  19. Atorvastatin increases hepatic fatty acid beta-oxidation in sucrose-fed rats: comparison with an MTP inhibitor.

    PubMed

    Funatsu, Toshiyuki; Kakuta, Hirotoshi; Takasu, Toshiyuki; Miyata, Keiji

    2002-11-29

    We investigated the effects of atorvastatin, a widely used 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, and BMS-201038, a microsomal triglyceride transfer protein (MTP) inhibitor, in sucrose-fed hypertriglyceridemic rats to determine whether the activation of beta-oxidation by these compounds plays a role in their hypotriglyceridemic effect. The decrease in plasma triglyceride concentration and post-Triton very low-density lipoprotein (VLDL) triglyceride concentration, a measure of hepatic triglyceride secretion, by atorvastatin (30 mg/kg p.o.) for 2 weeks was to approximately the same degree as those by BMS-201038 (0.3 mg/kg). Atorvastatin (30 mg/kg) increased hepatic beta-oxidation activity by 54% (P < 0.01), while BMS-201038 (0.3 mg/kg) had no significant effect. Atorvastatin decreased hepatic triglyceride, fatty acid and cholesteryl ester concentrations by 21% to 39%, whereas BMS-201038 increased these variables by 28% to 307%. In the atorvastatin-treated groups, a significant relationship was seen not only between hepatic beta-oxidation activity and hepatic triglyceride concentration (R(2) = 0.535, P < 0.01), but also between hepatic and plasma triglyceride concentrations (R(2) = 0.586, P < 0.01). No effect of atorvastatin on hepatic fatty acid synthesis was observed. These results indicate that the activation of hepatic beta-oxidation by atorvastatin may contribute to the decrease in hepatic triglyceride concentration, leading to its hypotriglyceridemic effect.

  20. Coinfection of hepatic cell lines with human immunodeficiency virus and hepatitis B virus leads to an increase in intracellular hepatitis B surface antigen.

    PubMed

    Iser, David M; Warner, Nadia; Revill, Peter A; Solomon, Ajantha; Wightman, Fiona; Saleh, Suha; Crane, Megan; Cameron, Paul U; Bowden, Scott; Nguyen, Tin; Pereira, Cândida F; Desmond, Paul V; Locarnini, Stephen A; Lewin, Sharon R

    2010-06-01

    Liver-related mortality is increased in the setting of HIV-hepatitis B virus (HBV) coinfection. However, interactions between HIV and HBV to explain this observation have not been described. We hypothesized that HIV infection of hepatocytes directly affects the life cycle of HBV. We infected human hepatic cell lines expressing HBV (Hep3B and AD38 cells) or not expressing HBV (Huh7, HepG2, and AD43 cells) with laboratory strains of HIV (NL4-3 and AD8), as well as a vesicular stomatitis virus (VSV)-pseudotyped HIV expressing enhanced green fluorescent protein (EGFP). Following HIV infection with NL4-3 or AD8 in hepatic cell lines, we observed a significant increase in HIV reverse transcriptase activity which was infectious. Despite no detection of surface CD4, CCR5, and CXCR4 by flow cytometry, AD8 infection of AD38 cells was inhibited by maraviroc and NL4-3 was inhibited by AMD3100, demonstrating that HIV enters AD38 hepatic cell lines via CCR5 or CXCR4. High-level infection of AD38 cells (50%) was achieved using VSV-pseudotyped HIV. Coinfection of the AD38 cell line with HIV did not alter the HBV DNA amount or species as determined by Southern blotting or nucleic acid signal amplification. However, coinfection with HIV was associated with a significant increase in intracellular HBsAg when measured by Western blotting, quantitative HBsAg, and fluorescence microscopy. We conclude that HIV infection of HBV-infected hepatic cell lines significantly increased intracellular HBsAg but not HBV DNA synthesis and that increased intrahepatic HBsAg secondary to direct infection by HIV may contribute to accelerated liver disease in HIV-HBV-coinfected individuals.

  1. [Gallbladder motor activity in patients with virus hepatitis B].

    PubMed

    Mamos, Arkadiusz; Wichan, Paweł; Chojnacki, Jan; Grzegorczyk, Krzysztof

    2003-12-01

    In acute stage of virus hepatitis B patients often complain of dyspeptic discomfort. They may be a consequence of alimentary tract motor activity disorders including these of gallbladder. Routine ultrasonography in an early phase of virus hepatitis often reveals gallbladder wall thickening what may confirm the above thesis. Thus, a group of 15 patients in an acute phase of virus hepatitis B was subjected to examinations. Gallbladder motor activity was assessed by ultrasonographic method determining its total volume and ejection fraction and volume after test meal stimulus. First examination was performed in the first week since the appearance of yellowing of the walls, successive in 4 and 8 week of the disease. Obtained results were compared to the values obtained in the group of 25 healthy volunteers. It was found out that gallbladder volume was significantly decreased and ejection fraction increased in the acute phase of virus hepatitis B than in the controls. This may speak for gallbladder hyperreactivity in patients in the course of virus hepatitis B. These disorders decreased during two-month observation but even in the 8 week the investigated parameters differed from those found in the control group.

  2. Hepatitis B virus replication in steroid-treated severe HBsAg-positive chronic active hepatitis.

    PubMed

    Davis, G L; Czaja, A J; Taswell, H F; Ludwig, J; Go, V L

    1985-02-01

    To determine the effect of corticosteroids on the replication of hepatitis B virus and to assess the relationship between virus replication and prognosis, the behavior of serum and tissue HBcAg was evaluated in 16 patients with severe HBsAg-positive chronic active hepatitis who were treated with prednisone and followed for up to 10 years (mean +/- SEM, 66 +/- 9 months). Hepatitis B virus replication was assessed in serum by a solid-phase radioimmunoassay of Dane particle-associated HBcAg and in liver tissue by indirect immunoperoxidase staining for HBcAg. Despite the presence of severe inflammatory activity, only low levels of hepatitis B virus replication were demonstrated. Mean serum HBcAg levels were low at accession and remained essentially unchanged or gradually decreased during corticosteroid therapy. Serum HBcAg appeared in only one patient in whom no virus replication was detected prior to therapy. HBeAg was frequently detected at low titers by radioimmunoassay when serum HBcAg was undetectable. Loss of HBcAg preceded loss of HBeAg by radioimmunoassay, and disappearance of both markers was a prerequisite for sustained histologic remission. In eight patients, inflammation was present despite absence of serum or tissue HBcAg; in three of these, disease activity continued after loss of HBeAg. We conclude that low levels of hepatitis B virus replication may be associated with severe inflammatory activity, and these levels are not increased by long-term corticosteroid therapy. Inflammation can continue despite loss of HBeAg and absence of detectable virus replication.

  3. Increased Hepatic Fatty Acids Uptake and Oxidation by LRPPRC-Driven Oxidative Phosphorylation Reduces Blood Lipid Levels

    PubMed Central

    Lei, Shi; Sun, Run-zhu; Wang, Di; Gong, Mei-zhen; Su, Xiang-ping; Yi, Fei; Peng, Zheng-wu

    2016-01-01

    Hyperlipidemia is one of the major risk factors of atherosclerosis and other cardiovascular diseases. This study aimed to investigate the impact of leucine rich pentatricopeptide repeat containing protein (LRPPRC)-driven hepatic oxidative phoshorylation on blood lipid levels. The hepatic LRPPRC level was modulated by liver-specific transgenic or adeno-associated virus 8 carried shRNA targeting Lrpprc (aav-shLrpprc). Mice were fed with a high fat diet to induce obesity. Gene expression was analyzed by quantitative real-time PCR and / or western blot. The hepatic ATP level, hepatic and serum lipids contents, and mitochondria oxidative phosphorylation (OxPhos) complex activities were measured using specific assay kits. The uptake and oxidation of fatty acid by hepatocytes were assessed using 14C-palmitate. LRPPRC regulated the expression of genes encoded by mitochondrial genome but not those by nuclear genome involved in mitochondria biogenesis, OxPhos, and lipid metabolism. Increased OxPhos in liver mediated by LRPPRC resulted in the increase of hepatic ATP level. Lrpprc promoted palmitate uptake and oxidation by hypatocytes. The hepatic and serum triglyceride and total cholesterol levels were inversely associated with the hepatic LRPPRC level. These data demonstrated that LRPPRC-driven hepatic OxPhos could promote fatty acids uptake and oxidation by hepatocytes and reduce both hepatic and circulating triglyceride and cholesterol levels. PMID:27462273

  4. Reduced brain levels of DHEAS in hepatic coma patients: significance for increased GABAergic tone in hepatic encephalopathy.

    PubMed

    Ahboucha, Samir; Talani, Giuseppe; Fanutza, Tomas; Sanna, Enrico; Biggio, Giovanni; Gamrani, Halima; Butterworth, Roger F

    2012-07-01

    Increased neurosteroids with allosteric modulatory activity on GABA(A) receptors such as 3α-5α tertrahydroprogesterone; allopregnanolone (ALLO), are candidates to explain the phenomenon of "increased GABAergic tone" in hepatic encephalopathy (HE). However, it is not known how changes of other GABA(A) receptor modulators such as dehydroepiandrosterone sulfate (DHEAS) contribute to altered GABAergic tone in HE. Concentrations of DHEAS were measured by radioimmunoassay in frontal cortex samples obtained at autopsy from 11 cirrhotic patients who died in hepatic coma and from an equal number of controls matched for age, gender, and autopsy delay intervals free from hepatic or neurological diseases. To assess whether reduced brain DHEAS contributes to increased GABAergic tone, in vitro patch clamp recordings in rat prefrontal cortex neurons were performed. A significant reduction of DHEAS (5.81±0.88 ng/g tissue) compared to control values (9.70±0.79 ng/g, p<0.01) was found. Brain levels of DHEAS in patients with liver disease who died without HE (11.43±1.74 ng/g tissue), and in a patient who died in uremic coma (12.56 ng/g tissue) were within the control range. Increasing ALLO enhances GABAergic tonic currents concentration-dependently, but increasing DHEAS reduces these currents. High concentrations of DHEAS (50 μM) reduce GABAergic tonic currents in the presence of ALLO, whereas reduced concentrations of DHEAS (1 μM) further stimulate these currents. These findings demonstrate that decreased concentrations of DHEAS together with increased brain concentrations of ALLO increase GABAergic tonic currents synergistically; suggesting that reduced brain DHEAS could further increase GABAergic tone in human HE.

  5. Impact of schistosomiasis on increase incidence of occult hepatitis B in chronic hepatitis C patients in Egypt.

    PubMed

    Omar, Hanan H; Taha, Samaa A; Hassan, Wafaa H; Omar, Hamdy H

    2017-02-09

    Co-infection of schistosomiasis, HBV and HCV is common in countries where schistosomiasis is endemic. Occult hepatitis B occurs in patients at high risk for HBV infection (e.g., patients on hemodialysis, patients receiving blood transfusions). Schistosomal infection is a risk factor of HBV infection that can increase the incidence of occult hepatitis B. We aimed to determine the prevalence of occult hepatitis B in chronic hepatitis C patients with and without schistosomiasis and to assess the effect of schistosomal infection on the increased risk of exposure to HBV infection and to occult hepatitis B. Two hundred chronic hepatitis C patients who were negative for HBsAg participated. All patients were tested for the following: Anti-schistosome antibodies, Anti-HBc, serum HBV DNA, CBC and liver function. The prevalence of occult hepatitis B in CHC patients with/without schistosomiasis were 12.8% and 8.5% (P=0.042), respectively. Next, 63.8% of CHC patients with schistosomiasis were exposed to HBV infection (Anti-HBc +ve) during their lifetime. In conclusion, the prevalence of occult hepatitis B is higher in CHC patients with schistosomiasis compared to those without schistosomiasis. Periodic laboratory investigations of Schistosoma mansoni, HBV and HCV are recommended for the early detection of the infection and, especially in endemic areas, to avoid infection complications.

  6. Saturated fatty acids activate ERK signaling to downregulate hepatic sortilin 1 in obese and diabetic mice.

    PubMed

    Bi, Lipeng; Chiang, John Y L; Ding, Wen-Xing; Dunn, Winston; Roberts, Benjamin; Li, Tiangang

    2013-10-01

    Hepatic VLDL overproduction is a characteristic feature of diabetes and an important contributor to diabetic dyslipidemia. Hepatic sortilin 1 (Sort1), a cellular trafficking receptor, is a novel regulator of plasma lipid metabolism and reduces plasma cholesterol and triglycerides by inhibiting hepatic apolipoprotein B production. Elevated circulating free fatty acids play key roles in hepatic VLDL overproduction and the development of dyslipidemia. This study investigated the regulation of hepatic Sort1 in obesity and diabetes and the potential implications in diabetic dyslipidemia. Results showed that hepatic Sort1 protein was markedly decreased in mouse models of type I and type II diabetes and in human individuals with obesity and liver steatosis, whereas increasing hepatic Sort1 expression reduced plasma cholesterol and triglycerides in mice. Mechanistic studies showed that the saturated fatty acid palmitate activated extracellular signal-regulated kinase (ERK) and inhibited Sort1 protein by mechanisms involving Sort1 protein ubiquitination and degradation. Consistently, hepatic ERK signaling was activated in diabetic mice, whereas blocking ERK signaling by an ERK inhibitor increased hepatic Sort1 protein in mice. These results suggest that increased saturated fatty acids downregulate liver Sort1 protein, which may contribute to the development of dyslipidemia in obesity and diabetes.

  7. Increased hepatic glucose production in fetal sheep with intrauterine growth restriction is not suppressed by insulin.

    PubMed

    Thorn, Stephanie R; Brown, Laura D; Rozance, Paul J; Hay, William W; Friedman, Jacob E

    2013-01-01

    Intrauterine growth restriction (IUGR) increases the risk for metabolic disease and diabetes, although the developmental origins of this remain unclear. We measured glucose metabolism during basal and insulin clamp periods in a fetal sheep model of placental insufficiency and IUGR. Compared with control fetuses (CON), fetuses with IUGR had increased basal glucose production rates and hepatic PEPCK and glucose-6-phosphatase expression, which were not suppressed by insulin. In contrast, insulin significantly increased peripheral glucose utilization rates in CON and IUGR fetuses. Insulin robustly activated AKT, GSK3β, and forkhead box class O (FOXO)1 in CON and IUGR fetal livers. IUGR livers, however, had increased basal FOXO1 phosphorylation, nuclear FOXO1 expression, and Jun NH(2)-terminal kinase activation during hyperinsulinemia. Expression of peroxisome proliferator-activated receptor γ coactivator 1α and hepatocyte nuclear factor-4α were increased in IUGR livers during basal and insulin periods. Cortisol and norepinephrine concentrations were positively correlated with glucose production rates. Isolated IUGR hepatocytes maintained increased glucose production in culture. In summary, fetal sheep with IUGR have increased hepatic glucose production, which is not suppressed by insulin despite insulin sensitivity for peripheral glucose utilization. These data are consistent with a novel mechanism involving persistent transcriptional activation in the liver that seems to be unique in the fetus with IUGR.

  8. Increased serum IgE in acute type A, B and delta hepatitis.

    PubMed

    Gutiérrez, D; Guardia, P; Delgado, J; Gutiérrez, J; Monteseirin, F J; de la Calle, A; Lobatón, P; Senra, A; Conde, J

    1997-01-01

    Serum IgE levels have been documented in patients of acute type B hepatitis. There are very few studies on serum IgE in acute type A hepatitis and, to our knowledge, there are no data on serum IgE in acute delta hepatitis patients. The purpose of this study was to measure total IgE levels in 38 patients with acute A, B and delta hepatitis and in 181 controls in order to determine the possible existence of changes in this parameter in the course of these infections. Our results showed a relevant increase in IgE levels in the three groups (hepatitis A, B and delta) with respect to the control group. Moreover, the hepatitis B group showed increased total serum IgE levels with respect to the hepatitis delta group.

  9. Increased hepatic expression of nitric oxide synthase type II in cirrhotic rats

    PubMed Central

    Wang, Hai; Chen, Xiao-Ping; Qiu, Fa-Zu

    2004-01-01

    AIM: To determine the role and effect of nitric oxide synthase type II (NOS II) in cirrhotic rats. METHODS: Expression of NOS II mRNA was detected by real time RT-PCR. The activity of nitric oxide synthase and serum levels of NO, systemic and portal hemodynamics and degrees of cirrhosis were measured with high sensitive methods. Chinese traditional medicine tetrandrine was used to treat cirrhotic rats and to evaluate the function of NO. Double-blind method was applied during the experiment. RESULTS: The concentration of NO and the activity of NOS were increased markedly at all stages of cirrhosis, and iNOSmRNA was greatly expressed. Meanwhile the portal-venous-pressure (PVP), and portal-venous-flow (PVF) were significantly increased. NO, NOS and iNOSmRNA were positively correlated to the quantity of hepatic fibrosis. Tetrandrine significantly inhibited NO production and the expression of iNOSmRNA. CONCLUSION: Increased hepatic expression of NOS II is one of the important causes of hepatic cirrhosis and portal hypertension. PMID:15222038

  10. Hepatitis

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Hepatitis KidsHealth > For Teens > Hepatitis Print A A A ... to a liver condition called hepatitis . What Is Hepatitis? The liver is one of the body's powerhouses. ...

  11. Hepatitis

    MedlinePlus

    ... de los dientes Video: Getting an X-ray Hepatitis KidsHealth > For Kids > Hepatitis Print A A A ... an important digestive liquid called bile . What Is Hepatitis? Hepatitis is an inflammation (say: in-fluh-MAY- ...

  12. [Hepatic manifestation of a macrophage activation syndrome (MAS)].

    PubMed

    Nagel, Michael; Schwarting, Andreas; Straub, Beate K; Galle, Peter R; Zimmermann, Tim

    2017-04-04

    Background Elevated liver values are the most common pathological laboratory result in Germany. Frequent findings, especially in younger patients, are nutritive- or medicamentous- toxic reasons, viral or autoimmune hepatitis. A macrophage activation syndrome (MAS) may manifest like a viral infectious disease with fever, hepatosplenomegaly and pancytopenia and is associated with a high mortality. It is based on an enhanced activation of macrophages with increased cytokine release, leading to organ damage and multi-organ failure. In addition to genetic causes, MAS is commonly associated with infections and rheumatic diseases. We report the case of a 26-year-old female patient suffering from MAS as a rare cause of elevated liver enzymes. Methods Patient characteristics, laboratory values, liver histology, bone marrow and radiological imaging were documented and analyzed. Case Report After an ordinary upper airway infection with bronchitis, a rheumatic arthritis appeared and was treated with leflunomide und methotrexate. In the further course of the disease, the patient developed an acute hepatitis with fever, pancytopenia and massive hyperferritinemia. Immunohistochemistry of the liver biopsy revealed hemophagocytosis and activation of CD68-positive macrophages. In the radiological and histological diagnostics of the liver and bone marrow, an MAS was diagnosed as underlying disease of the acute hepatitis. Under therapy with prednisolone, the fever disappeared and transaminases and ferritin rapidly normalized. Conclusion Aside from the frequent causes of elevated liver values in younger patients, such as nutritive toxic, drug induced liver injury, viral or autoimmune hepatitis, especially in case of massive hyperferritinemia, a MAS should be considered as a rare cause of acute liver disease.

  13. Association of interleukin-15-induced peripheral immune activation with hepatic stellate cell activation in persons coinfected with hepatitis C virus and HIV.

    PubMed

    Allison, Robert D; Katsounas, Antonios; Koziol, Deloris E; Kleiner, David E; Alter, Harvey J; Lempicki, Richard A; Wood, Brad; Yang, Jun; Fullmer, Brandie; Cortez, Karoll J; Polis, Michael A; Kottilil, Shyam

    2009-08-15

    Hepatic stellate cells (HSCs) mediate hepatitis C virus (HCV)-related liver fibrosis, and increased HSC activation in human immunodeficiency virus (HIV)/HCV coinfection may be associated with accelerated fibrosis. We examined the level of HSC activation in HIV/HCV-coinfected and HCV-monoinfected subjects and its relationship to the level of activation and gene expression of peripheral immune cells in coinfected subjects. HSC activation levels positively correlated with peripheral CD4+ and CD8+ T cell immune activation and were associated with enhanced interleukin-15 (IL-15) gene expression, suggesting a pathogenic role for IL-15-driven immunomediated hepatic fibrosis. Future strategies that reduce immune activation and HSC activation may delay progression of liver fibrosis.

  14. Assessing and Increasing Physical Activity

    ERIC Educational Resources Information Center

    Van Camp, Carole M.; Hayes, Lynda B.

    2012-01-01

    Increasing physical activity is a crucial component of any comprehensive approach to combat the growing obesity epidemic. This review summarizes recent behavioral research on the measurement of physical activity and interventions aimed at increasing physical activity and provides directions for future research.

  15. Inhibitors of cholesterol biosynthesis increase hepatic low-density lipoprotein receptor protein degradation.

    PubMed

    Ness, G C; Zhao, Z; Lopez, D

    1996-01-15

    Inhibitors of cholesterol biosynthesis are believed to lower serum cholesterol levels by enhancing the removal of serum low-density lipoprotein (LDL) by increasing hepatic LDL receptor function. Thus, the effects of several different inhibitors of cholesterol biosynthesis were examined for their effects on the expression of the hepatic LDL receptor in rats. We found that administration of inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase such as lovastatin, pravastatin, fluvastatin, and rivastatin resulted in increased hepatic LDL receptor mRNA levels. Surprisingly, these agents failed to increase levels of immunoreactive LDL receptor protein in rat liver even when the dose and length of treatment were increased. Treatment of rats with zaragozic acid A, an inhibitor of squalene synthase, caused even greater increases in hepatic LDL receptor mRNA levels, but did not increase levels of immunoreactive protein. Further investigation revealed that the rate of degradation of the hepatic LDL receptor was increased in rats given inhibitors of cholesterol biosynthesis. The greatest increase in the rate of degradation was seen in animals treated with zaragozic acid A which caused the largest increase in hepatic LDL receptor mRNA levels. In contrast, hepatic LDL receptor protein was stabilized in cholesterol-fed rats. It appears that increased potential for LDL receptor protein synthesis, reflected in increased mRNA levels, is offset by a corresponding increase in the rate of receptor protein degradation resulting in constant steady-state levels of hepatic LDL receptor protein. These findings are suggestive of increased cycling of the hepatic LDL receptor. This postulated mechanism can provide for enhanced hepatic uptake of lipoproteins without increasing steady-state levels of LDL receptor protein.

  16. MBOAT7 rs641738 increases risk of liver inflammation and transition to fibrosis in chronic hepatitis C

    PubMed Central

    Thabet, Khaled; Asimakopoulos, Anastasia; Shojaei, Maryam; Romero-Gomez, Manuel; Mangia, Alessandra; Irving, William L.; Berg, Thomas; Dore, Gregory J.; Grønbæk, Henning; Sheridan, David; Abate, Maria Lorena; Bugianesi, Elisabetta; Weltman, Martin; Mollison, Lindsay; Cheng, Wendy; Riordan, Stephen; Fischer, Janett; Spengler, Ulrich; Nattermann, Jacob; Wahid, Ahmed; Rojas, Angela; White, Rose; Douglas, Mark W.; McLeod, Duncan; Powell, Elizabeth; Liddle, Christopher; van der Poorten, David; George, Jacob; Eslam, Mohammed; Gallego-Duran, Rocio; Applegate, Tanya; Bassendine, Margaret; Rosso, Chiara; Mezzabotta, Lavinia; Leung, Reynold; Malik, Barbara; Matthews, Gail; Grebely, Jason; Fragomeli, Vincenzo; Jonsson, Julie R.; Santaro, Rosanna

    2016-01-01

    Cirrhosis likely shares common pathophysiological pathways despite arising from a variety of liver diseases. A recent GWAS identified rs641738, a polymorphism in the MBOAT7 locus, as being associated with the development of alcoholic cirrhosis. Here we explore the role of this variant on liver inflammation and fibrosis in two cohorts of patients with chronic hepatitis C. In 2,051 patients, rs641738 associated with severe hepatic inflammation and increased risk of fibrosis, as well as fast fibrosis progression. At functional level, rs641738 associated with MBOAT7 transcript and protein levels in liver and blood, and with serum inflammatory, oxidative stress and macrophage activation markers. MBOAT7 was expressed in immune cell subsets, implying a role in hepatic inflammation. We conclude that the MBOAT7 rs641738 polymorphism is a novel risk variant for liver inflammation in hepatitis C, and thereby for liver fibrosis. PMID:27630043

  17. Central Insulin Action Activates Kupffer Cells by Suppressing Hepatic Vagal Activation via the Nicotinic Alpha 7 Acetylcholine Receptor.

    PubMed

    Kimura, Kumi; Tanida, Mamoru; Nagata, Naoto; Inaba, Yuka; Watanabe, Hitoshi; Nagashimada, Mayumi; Ota, Tsuguhito; Asahara, Shun-ichiro; Kido, Yoshiaki; Matsumoto, Michihiro; Toshinai, Koji; Nakazato, Masamitsu; Shibamoto, Toshishige; Kaneko, Shuichi; Kasuga, Masato; Inoue, Hiroshi

    2016-03-15

    Central insulin action activates hepatic IL-6/STAT3 signaling, which suppresses the gene expression of hepatic gluconeogenic enzymes. The vagus nerve plays an important role in this centrally mediated hepatic response; however, the precise mechanism underlying this brain-liver interaction is unclear. Here, we present our findings that the vagus nerve suppresses hepatic IL-6/STAT3 signaling via α7-nicotinic acetylcholine receptors (α7-nAchR) on Kupffer cells, and that central insulin action activates hepatic IL-6/STAT3 signaling by suppressing vagal activity. Indeed, central insulin-mediated hepatic IL-6/STAT3 activation and gluconeogenic gene suppression were impeded in mice with hepatic vagotomy, pharmacological cholinergic blockade, or α7-nAchR deficiency. In high-fat diet-induced obese and insulin-resistant mice, control of the vagus nerve by central insulin action was disturbed, inducing a persistent increase of inflammatory cytokines. These findings suggest that dysregulation of the α7-nAchR-mediated control of Kupffer cells by central insulin action may affect the pathogenesis of chronic hepatic inflammation in obesity.

  18. Hyperhyaluronanemia in alcoholic hepatitis is associated with increased levels of circulating soluble intercellular adhesion molecule-1.

    PubMed

    Hill, D B; Deaciuc, I V; McClain, C J

    1998-09-01

    The purpose of this study was to evaluate the role of the sinusoidal endothelial cell (SEC) during the clinical course of alcoholic hepatitis. Twenty consenting patients (mean age: 49.4 +/- 11.0 years) with moderate or severe hepatitis were studied. The patients were selected and characterized according to their history of drinking and laboratory profile, including serum aminotransferases, bilirubin, total white blood cell and neutrophil count, and prothrombin times. C-reactive protein and interleukin-6 were also measured as markers of the hepatic acute phase response. A marker of the SEC functional state, the circulating level of hyaluronan, was measured in parallel with the circulating levels of soluble intercellular adhesion molecule (sICAM)-1 over a 6-month observation period. All patients were hospitalized for the first month and encouraged to abstain from drinking for the duration of the study. The initial increased levels of both hyaluronan (542 +/- 32 ng x ml(-1) serum) and sICAM-1 (488 +/- 70 ng x ml(-1) serum), gradually fell during the 6-month observation period, eventually reaching values close to those seen in healthy subjects. A positive correlation was obtained between changes in these two markers of SEC function/activation on the one hand, and between these two tests and bilirubin, on the other hand. These data indicate that abnormalities of SEC function/activation, as reflected by serum hyaluronan and siCAM-1, are prominent in alcoholic hepatitis, and these alterations improve within relatively short periods of time after cessation of alcohol consumption.

  19. A high-fat, ketogenic diet causes hepatic insulin resistance in mice, despite increasing energy expenditure and preventing weight gain.

    PubMed

    Jornayvaz, François R; Jurczak, Michael J; Lee, Hui-Young; Birkenfeld, Andreas L; Frederick, David W; Zhang, Dongyang; Zhang, Xian-Man; Samuel, Varman T; Shulman, Gerald I

    2010-11-01

    Low-carbohydrate, high-fat ketogenic diets (KD) have been suggested to be more effective in promoting weight loss than conventional caloric restriction, whereas their effect on hepatic glucose and lipid metabolism and the mechanisms by which they may promote weight loss remain controversial. The aim of this study was to explore the role of KD on liver and muscle insulin sensitivity, hepatic lipid metabolism, energy expenditure, and food intake. Using hyperinsulinemic-euglycemic clamps, we studied insulin action in mice fed a KD or regular chow (RC). Body composition was assessed by ¹H magnetic resonance spectroscopy. Despite being 15% lighter (P < 0.001) than RC-fed mice because of a 17% increase in energy expenditure (P < 0.001), KD-fed mice manifested severe hepatic insulin resistance, as reflected by decreased suppression (0% vs. 100% in RC-fed mice, P < 0.01) of endogenous glucose production during the clamp. Hepatic insulin resistance could be attributed to a 350% increase in hepatic diacylglycerol content (P < 0.001), resulting in increased activation of PKCε (P < 0.05) and decreased insulin receptor substrate-2 tyrosine phosphorylation (P < 0.01). Food intake was 56% (P < 0.001) lower in KD-fed mice, despite similar caloric intake, and could partly be attributed to a more than threefold increase (P < 0.05) in plasma N-acylphosphatidylethanolamine concentrations. In conclusion, despite preventing weight gain in mice, KD induces hepatic insulin resistance secondary to increased hepatic diacylglycerol content. Given the key role of nonalcoholic fatty liver disease in the development of type 2 diabetes and the widespread use of KD for the treatment of obesity, these results may have potentially important clinical implications.

  20. High-Fat Diet Increased Renal and Hepatic Oxidative Stress Induced by Vanadium of Wistar Rat.

    PubMed

    Wang, J P; Cui, R Y; Zhang, K Y; Ding, X M; Luo, Y H; Bai, S P; Zeng, Q F; Xuan, Y; Su, Z W

    2016-04-01

    The study was conducted to assess the effect of vanadium (V) in high-fat diet on the liver and kidney of rats in a 5-week trial. Seventy-two female Wistar rats (BW = 95 ± 5 g) were randomly allotted into eight groups. Groups I, II, III, and IV obtained low-fat diet containing 0, 3, 15, and 30 mg/kg V, and V, VI, VII, and VIII groups received the respective vanadium doses with high-fat diet, respectively. There were lesions in the liver and kidney of V, VI, VII, and VIII groups, granular degeneration and vacuolar degeneration were observed in the renal tubular and glomerulus epithelial cells, and hepatocytes showed granular degeneration and vacuolar degeneration. Supplemented high-fat diet with vanadium was shown to decrease (P < 0.05) activities of superoxide dismutase, total antioxidant capacity, glutathione-S transferase, and NAD(P)H/quinone oxidoreductase 1 (NQO1) and increase malondialdehyde content in the liver and kidney. The relative expression of hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) and NQO1 mRNA was downregulated by V addition and high-fat diet, and the effect of V was more pronounced in high-fat diet (interaction, P < 0.05), with VIII group having the lowest mRNA expression of Nrf-2 and NQO1 in the liver and kidney. In conclusion, it suggested that dietary vanadium ranging from 15 to 30 mg/kg could lead to oxidative damage and vanadium accumulation in the liver and kidney, which caused renal and hepatic toxicity. The high-fat diet enhanced vanadium-induced hepatic and renal damage, and the mechanism was related to the modulation of the hepatic and renal mRNA expression of Nrf-2 and NQO1.

  1. RSPOs facilitated HSC activation and promoted hepatic fibrogenesis

    PubMed Central

    Yin, Xinguang; Yi, Huixing; Wang, Linlin; Wu, Wanxin; Wu, Xiaojun; Yu, Linghua

    2016-01-01

    Roof plate-specific spondin (RSPO) proteins are potent Wnt pathway agonists and involve in a broad range of developmental and physiological processes. This study investigated the activities and mechanisms of RSPOs in liver fibrogenesis, especially in hepatic stellate cell (HSC) activation. HSC activation was assessed by fibrosis biomarker (α-smooth muscle actin and Collagen-I), phenotypic change (accumulation of lipid droplets), and increased proliferation. Similarly, Wnt pathway activity was evaluated by the expression of nuclear β-catenin and T cell-specific transcription factors (TCF) activity. We found RSPOs were overexpressed in human fibrotic liver tissue and the expressions were correlated with liver fibrosis stages. In vitro studies showed RSPOs level increased during HSC activation, and stimuli with RSPOs enhanced Wnt pathway activity and promoted HSC activation subsequently. Furthermore, in vivo experiments demonstrated that the knockdown of RSPOs suppressed both Wnt pathway activity and HSC activation. Interestingly, the inhibitor of the Wnt signaling pathway Dickkopf1 impairs RSPOs effects on HSCs. Taken together, our results revealed that RSPOs facilitated HSC activation and promote liver fibrogenesis by enhancing the Wnt pathway. PMID:27572318

  2. Exendin-4 Inhibits Hepatic Lipogenesis by Increasing β-Catenin Signaling

    PubMed Central

    Hong, Seok-Woo; Rhee, Eun-Jung; Park, Se Eun; Park, Cheol Young; Oh, Ki Won; Park, Sung Woo; Lee, Won-Young

    2016-01-01

    The aim of this study is to investigate whether the beneficial effect of exendin-4 on hepatic steatosis is mediated by β-catenin signaling. After the HepG2 human hepatoma cells were treated with PA for 24 hours, total triglycerides levels were increased in a dose-dependent manner, and the expression levels of perilipin family members were upregulated in cells treated with 400 μM PA. For our in vitro model of hepatic steatosis, HepG2 cells were treated with 400 μM palmitic acid (PA) in the presence or absence of 100 nM exendin-4 for 24 hours. PA increased the expression of lipogenic genes, such as sterol regulatory element-binding protein 1c (SREBP-1c), peroxisome proliferator-activated receptor gamma (PPARγ), stearoyl-CoA desaturase 1 (SCD1), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) and triglyceride synthesis-involved genes, such as diacylglycerol acyltransferase 1 (DGAT1) and diacylglycerol acyltransferase 2 (DGAT2) in HepG2 cells, whereas exendin-4 treatment significantly prevented the upregulation of SREBP-1c, PPARγ, SCD1, FAS, ACC, DGAT1 and DGAT2. Moreover, exendin-4 treatment increased the expression of phosphorylated glycogen synthase kinase-3 beta (GSK-3β) in the cytosolic fraction and the expression of β-catenin and transcription factor 4 (TCF4) in the nuclear fraction. In addition, siRNA-mediated inhibition of β-catenin upregulated the expression of lipogenic transcription factors. The protective effects of exendin-4 on intracellular triglyceride content and total triglyceride levels were not observed in cells treated with the β-catenin inhibitor IWR-1. These data suggest that exendin-4 treatment improves hepatic steatosis by inhibiting lipogenesis via activation of Wnt/β-catenin signaling. PMID:27907035

  3. Increased caffeine consumption is associated with reduced hepatic fibrosis.

    PubMed

    Modi, Apurva A; Feld, Jordan J; Park, Yoon; Kleiner, David E; Everhart, James E; Liang, T Jake; Hoofnagle, Jay H

    2010-01-01

    Although coffee consumption has been associated with reduced frequency of liver disease, it is unclear whether the effect is from coffee or caffeine and whether there is an effect on hepatic fibrosis specifically. This study was undertaken to use a food-frequency instrument for dietary caffeine consumption to evaluate the relationship between caffeine intake and liver fibrosis. Patients undergoing liver biopsy completed a detailed caffeine questionnaire on three occasions over a 6-month period. Caffeine intake was compared between patients with mild and advanced liver fibrosis (bridging fibrosis/cirrhosis). Logistic regression was used to evaluate the association between caffeine consumption and hepatic fibrosis. One hundred seventy-seven patients (99 male, 104 white, 121 with chronic hepatitis C virus [HCV] infection) undergoing liver biopsy completed the caffeine questionnaire on up to three occasions. Results from repeated questionnaires were consistent. Daily caffeine consumption above the 75(th) percentile for the cohort (308 mg = approximately 2.25 cups of coffee equivalents) was associated with reduced liver fibrosis (odds ratio [OR], 0.33; 95% confidence interval [CI], 0.14-0.80; P = 0.015) and the protective association persisted after controlling for age, sex, race, liver disease, body mass index, and alcohol intake in all patients (OR, 0.25; 95% CI, 0.09-0.67; P = 0.006), as well as the subset with HCV infection (OR, 0.19; 95% CI, 0.05-0.66; P = 0.009). Despite a modest trend, consumption of caffeine from sources other than coffee or of decaffeinated coffee was not associated with reduced liver fibrosis. A reliable tool for measurement of caffeine consumption demonstrated that caffeine consumption, particularly from regular coffee, above a threshold of approximately 2 coffee-cup equivalents per day, was associated with less severe hepatic fibrosis.

  4. Hepatic SATB1 induces paracrine activation of hepatic stellate cells and is upregulated by HBx

    PubMed Central

    Gong, Jin; Tu, Wei; Han, Jian; He, Jiayi; Liu, Jingmei; Han, Ping; Wang, Yunwu; Li, Mengke; Liu, Mei; Liao, Jiazhi; Tian, Dean

    2016-01-01

    Chronic hepatitis B virus (HBV) infection is a major cause of chronic liver diseases, but its involvement in hepatic fibrogenesis remains unclear. Special AT-rich binding protein 1 (SATB1) has been implicated in reprogramming chromatin organization and transcription profiles in many cancers and non-cancer-related conditions. We found that hepatic SATB1 expression was significantly up-regulated in fibrotic tissues from chronic hepatitis B virus (HBV)-infected patients and HBV transgenic (HBV-Tg) mouse model. Knockdown of SATB1 in the liver significantly alleviated CCl4-induced fibrosis in HBV-Tg mouse model. Moreover, we suggested HBV encoded x protein (HBx) induced SATB1 expression through activation of JNK and ERK pathways. Enforced expression of SATB1 in hepatocytes promoted the activation and proliferation of hepatic stellate cells (HSCs) by secretion of connective tissue growth factor (CTGF), Interleukin-6 (IL-6) and platelet derived growth factor-A (PDGF-AA). Our findings demonstrated that HBx upregulated hepatic SATB1 which exerted pro-fibrotic effects by paracrine activation of stellate cells in HBV-related fibrosis. PMID:27883059

  5. Alcohol Increases Liver Progenitor Populations and Induces Disease Phenotypes in Human IPSC-Derived Mature Stage Hepatic Cells

    PubMed Central

    Tian, Lipeng; Deshmukh, Abhijeet; Prasad, Neha; Jang, Yoon-Young

    2016-01-01

    Alcohol consumption has long been a global problem affecting human health, and has been found to influence both fetal and adult liver functions. However, how alcohol affects human liver development and liver progenitor cells remains largely unknown. Here, we used human induced pluripotent stem cells (iPSCs) as a model to examine the effects of alcohol, on multi-stage hepatic cells including hepatic progenitors, early and mature hepatocyte-like cells derived from human iPSCs. While alcohol has little effect on endoderm development from iPSCs, it reduces formation of hepatic progenitor cells during early hepatic specification. The proliferative activities of early and mature hepatocyte-like cells are significantly decreased after alcohol exposure. Importantly, at a mature stage of hepatocyte-like cells, alcohol treatment increases two liver progenitor subsets, causes oxidative mitochondrial injury and results in liver disease phenotypes (i.e., steatosis and hepatocellular carcinoma associated markers) in a dose dependent manner. Some of the phenotypes were significantly improved by antioxidant treatment. This report suggests that fetal alcohol exposure may impair generation of hepatic progenitors at early stage of hepatic specification and decrease proliferation of fetal hepatocytes; meanwhile alcohol injury in post-natal or mature stage human liver may contribute to disease phenotypes. This human iPSC model of alcohol-induced liver injury can be highly valuable for investigating alcoholic injury in the fetus as well as understanding the pathogenesis and ultimately developing effective treatment for alcoholic liver disease in adults. PMID:27570479

  6. Intracerebroventricular Catalase Reduces Hepatic Insulin Sensitivity and Increases Responses to Hypoglycemia in Rats.

    PubMed

    Pauliina Markkula, S; Lyons, David; Yueh, Chen-Yu; Riches, Christine; Hurst, Paul; Fielding, Barbara; Heisler, Lora K; Evans, Mark L

    2016-12-01

    Specialized metabolic sensors in the hypothalamus regulate blood glucose levels by influencing hepatic glucose output and hypoglycemic counterregulatory responses. Hypothalamic reactive oxygen species (ROS) may act as a metabolic signal-mediating responses to changes in glucose, other substrates and hormones. The role of ROS in the brain's control of glucose homeostasis remains unclear. We hypothesized that hydrogen peroxide (H2O2), a relatively stable form of ROS, acts as a sensor of neuronal glucose consumption and availability and that lowering brain H2O2 with the enzyme catalase would lead to systemic responses increasing blood glucose. During hyperinsulinemic euglycemic clamps in rats, intracerebroventricular catalase infusion resulted in increased hepatic glucose output, which was associated with reduced neuronal activity in the arcuate nucleus of the hypothalamus. Electrophysiological recordings revealed a subset of arcuate nucleus neurons expressing proopiomelanocortin that were inhibited by catalase and excited by H2O2. During hypoglycemic clamps, intracerebroventricular catalase increased glucagon and epinephrine responses to hypoglycemia, consistent with perceived lower glucose levels. Our data suggest that H2O2 represents an important metabolic cue, which, through tuning the electrical activity of key neuronal populations such as proopiomelanocortin neurons, may have a role in the brain's influence of glucose homeostasis and energy balance.

  7. Intracerebroventricular Catalase Reduces Hepatic Insulin Sensitivity and Increases Responses to Hypoglycemia in Rats

    PubMed Central

    Pauliina Markkula, S.; Lyons, David; Yueh, Chen-Yu; Riches, Christine; Hurst, Paul; Fielding, Barbara; Heisler, Lora K.

    2016-01-01

    Specialized metabolic sensors in the hypothalamus regulate blood glucose levels by influencing hepatic glucose output and hypoglycemic counterregulatory responses. Hypothalamic reactive oxygen species (ROS) may act as a metabolic signal-mediating responses to changes in glucose, other substrates and hormones. The role of ROS in the brain's control of glucose homeostasis remains unclear. We hypothesized that hydrogen peroxide (H2O2), a relatively stable form of ROS, acts as a sensor of neuronal glucose consumption and availability and that lowering brain H2O2 with the enzyme catalase would lead to systemic responses increasing blood glucose. During hyperinsulinemic euglycemic clamps in rats, intracerebroventricular catalase infusion resulted in increased hepatic glucose output, which was associated with reduced neuronal activity in the arcuate nucleus of the hypothalamus. Electrophysiological recordings revealed a subset of arcuate nucleus neurons expressing proopiomelanocortin that were inhibited by catalase and excited by H2O2. During hypoglycemic clamps, intracerebroventricular catalase increased glucagon and epinephrine responses to hypoglycemia, consistent with perceived lower glucose levels. Our data suggest that H2O2 represents an important metabolic cue, which, through tuning the electrical activity of key neuronal populations such as proopiomelanocortin neurons, may have a role in the brain's influence of glucose homeostasis and energy balance. PMID:27740870

  8. Hepatitis

    MedlinePlus

    ... clotting problems or chronic liver disease. previous continue Hepatitis B and Hepatitis C Although hep A is a ... does — through direct contact with infected body fluids. Hepatitis B and C are even more easily passed in ...

  9. Hepatitis

    MedlinePlus

    ... A if they've been vaccinated against it. Hepatitis B Hepatitis B is a more serious infection. It may lead ... of which cause severe illness and even death. Hepatitis B virus (HBV) is transmitted from person to person ...

  10. Hepatitis

    MedlinePlus

    ... Issues Listen Español Text Size Email Print Share Hepatitis Page Content Article Body Hepatitis means “inflammation of ... it has been associated with drinking contaminated water. Hepatitis Viruses Type Transmission Prognosis A Fecal-oral (stool ...

  11. [Hepatitis non-A, non-B: epidemiological significance in acute viral hepatitis and chronic active hepatitis of hepatological consultation].

    PubMed

    Jmelnitzky, A C; Basualdo, J A; Belloni, P O; Ponce de León, H H; García, C; Curciarello, J

    1987-01-01

    157 acute viral hepatitis and 60 chronic active ones have been analyzed focusing on NANB etiology. HAV was implicated in 36.3% of the hole acute viral hepatitis sample, HBV in 29.3%, and HNANBV was presumed as etiology in 31.2%, 5 patients (3.2%) had acute infection by HAV, on previous one by HBV, except for Epstein-Barr virus, no other test for viruses were determined (CMV, HSV, etc.). Male/female ratio was 1.4:1, 1.9:1, and 1.4:1 for HAV, HBV and HNANBV acute hepatitis respectively; HAV was the main etiology in the 0-9 age group (72.2%) although it only represents 11.5% of the sample; small occurrence of HAV hepatitis were found in patients over 40 (8.8%); HBV was clearly prevalent in patients over 50 (65.2%); the highest concentration of NANB etiology was found between 20-39 years old, but it was represented in all age-groups. Out of 49 NANB acute hepatitis, 12.2% had related transfusional antecedents, 12.2% belonged to health care worker group, and 4.1% had a close family NANB hepatitis contact; 71.5% had no reported antecedent. Viral source was presumably implicated in 75.0% of chronic active hepatitis, 25.0% attributable to HNANBV. Results seem not feasible to transfer to general population due to the facts that most patients were of specialized consult, and pediatric assistance is unusual to the authors practice.

  12. [Chronic active hepatitis: clinical, biochemical, and histopathologic correlation].

    PubMed

    Subauste, M C

    1989-01-01

    A retrospective study over 26 female patients with chronic active hepatitis was made. The mean age was 39 years old, the mean length of illness of 8 months; 5 patients had positive markers for hepatitis B. Patients were selected with the grade of histological activity: 8 patients had a mild form from disease (2A) and 16 with a severe one (2B). The predominant group was 2B. Severe inflammatory infiltration was the hallmark and multiobulillar necrosis, bridging, eosinophils and hiperplasia of kuppfer cells were found only in this group. Clinical features range from hepatic manifestations to systemic ones. Chronic active hepatitis may present with cholestasis, but the latter is not always related with the grade of activity. Group 2B had elevated aminotransferases and a low concentration for protrobine.

  13. Increased Spreading Activation in Depression

    ERIC Educational Resources Information Center

    Foster, Paul S.; Yung, Raegan C.; Branch, Kaylei K.; Stringer, Kristi; Ferguson, Brad J.; Sullivan, William; Drago, Valeria

    2011-01-01

    The dopaminergic system is implicated in depressive disorders and research has also shown that dopamine constricts lexical/semantic networks by reducing spreading activation. Hence, depression, which is linked to reductions of dopamine, may be associated with increased spreading activation. However, research has generally found no effects of…

  14. Increased prevalence of coronary artery disease risk markers in patients with chronic hepatitis C – a cross-sectional study

    PubMed Central

    Roed, Torsten; Kristoffersen, Ulrik Sloth; Knudsen, Andreas; Wiinberg, Niels; Lebech, Anne-Mette; Almdal, Thomas; Thomsen, Reimar W; Kjær, Andreas; Weis, Nina

    2014-01-01

    Objective Chronic hepatitis C is a global health problem and has been associated with coronary artery disease. Our aim was to examine the prevalence of coronary artery disease risk markers including endothelial biomarkers in patients with chronic hepatitis C and matched comparisons without manifest cardiovascular disease or diabetes in a cross-sectional design. Methods Sixty patients with chronic hepatitis C (mean age 51 years) were recruited from the Department of Infectious Diseases at Copenhagen University Hospital, and compared with 60 age-matched non-hepatitis C virus-infected individuals from a general population survey. We examined traditional coronary artery disease risk factors, metabolic syndrome, carotid intima media thickness, and a range of endothelial biomarkers. Results Patients with chronic hepatitis C had more hypertension (40% versus 25%, prevalence ratio [PR] 1.6; 95% confidence interval [CI] 0.9–2.7) and smoked more (53% versus 38%, PR 1.4; 95% CI 0.9–2.1). The two groups had similar body mass index (mean 25.0 versus 25.7 kg/m2), whereas those with chronic hepatitis C had less dyslipidemia (including significantly lower low-density lipoprotein and cholesterol/high-density lipoprotein ratio), higher glycosylated hemoglobin level (mean 6.2 versus 5.7, difference of means 0.5; 95% CI 0.3–0.8), and a higher prevalence of metabolic syndrome (28% versus 18%, PR 1.6; 95% CI 0.8–3.0). Increased carotid intima media thickness above the standard 75th percentile was seen more frequently in chronic hepatitis C (9% versus 3%, PR 1.7; 95% CI 0.4–6.7), though difference of means was only 0.04 mm (95% CI 0.00–0.10). Patients with chronic hepatitis C had increased hsCRP (high-sensitivity C-reactive protein), sICAM-1 (soluble intercellular adhesion molecule-1), sVCAM-1 (soluble vascular cell adhesion molecule-1), and soluble E-selectin, but lower levels of tPAI-1 (tissue-type plasminogen activator inhibitor-1), MMP9 (matrix metallopeptidase 9), and

  15. Rapid increase in the national treatment costs for hepatitis A infections in Korea.

    PubMed

    Park, Hee Suk; Choi, Bo Youl; Kwon, Young Dae

    2012-01-01

    The number of symptomatic hepatitis A cases has progressively been increasing during the last several years in Korea. Available cost estimates indicate a growing burden to the public. The purpose of this study was to determine the extent of treatment costs for patients with hepatitis A and to analyze the influential factors with nationwide data. We collected data on 72,921 patients with hepatitis A from 5-year National Health Insurance claim archives between 2004 and 2008. Multiple regression analyses were conducted to examine influential factors affecting treatment costs for hepatitis A. Total treatment costs for patients with hepatitis A during the 5-year period were US$47,902,087 and increased significantly each year. In total, 91.4% of treatment costs were used for hospitalization, and the proportion of inpatients increased gradually throughout the study period. The most influential factor on treatment costs was treatment duration. Our results show that the soaring number of patients with hepatitis A followed by the hospitalization-focused treatment practice is a major factor associated with the rapid increase in treatment costs. Appropriate policies should be promptly developed to control treatment costs and economic burden of hepatitis A infections.

  16. Valproic Acid Increases the Hepatic Differentiation Potential of Salivary Gland Cells

    PubMed Central

    Petrakova, O. S.; Ashapkin, V. V.; Shtratnikova, V. Y.; Kutueva, L. I.; Vorotelyak, E. A.; Borisov, M. A.; Terskikh, V. V.; Gvazava, I. G.; Vasiliev, A. V.

    2015-01-01

    The studies of cell plasticity and differentiation abilities are important problems in modern cellular biology. The use of histone deacetylase inhibitor - valproic acid is a promising approach to increasing the differentiation efficiency of various cell types. In this paper we investigate the ability of mouse submandibular salivary gland cells to differentiate into the hepatic direction and the effect of valproic acid on the efficiency of this differentiation. It was shown that the gene expression levels of hepatocyte markers (Aat, Afp, G6p, Pepck, Tat, Cyp3a13) and liver-enriched transcription factors (Hnf-3α, Hnf-3β, Hnf-4α, Hnf-6) were increased after differentiation in salivary gland cells. Valproic acid increases the specificity of hepatic differentiation, reducing the expression levels of the ductal (Krt19, Hhex1, Cyp7a1) and acinar (Ptf1a) markers. After valproic acid exposure, the efficiency of hepatic differentiation also increases, as evidenced by the increase in the gene expression level of Alb and Tdo, and increase in urea production by differentiated cells. No change was found in DNA methylation of the promoter regions of the genes; however, valproic acid treatment and subsequent hepatic differentiation largely affected the histone H3 methylation of liver-enriched genes. Thus, mouse submandibular salivary gland cells are capable of effective differentiation in the hepatic direction. Valproic acid increases the specificity and efficiency of the hepatic differentiation of these cells. PMID:26798494

  17. Prox1 ablation in hepatic progenitors causes defective hepatocyte specification and increases biliary cell commitment

    PubMed Central

    Seth, Asha; Ye, Jianming; Yu, Nanjia; Guez, Fanny; Bedford, David C.; Neale, Geoffrey A.; Cordi, Sabine; Brindle, Paul K.; Lemaigre, Frederic P.; Kaestner, Klaus H.; Sosa-Pineda, Beatriz

    2014-01-01

    The liver has multiple functions that preserve homeostasis. Liver diseases are debilitating, costly and often result in death. Elucidating the developmental mechanisms that establish the liver’s architecture or generate the cellular diversity of this organ should help advance the prevention, diagnosis and treatment of hepatic diseases. We previously reported that migration of early hepatic precursors away from the gut epithelium requires the activity of the homeobox gene Prox1. Here, we show that Prox1 is a novel regulator of cell differentiation and morphogenesis during hepatogenesis. Prox1 ablation in bipotent hepatoblasts dramatically reduced the expression of multiple hepatocyte genes and led to very defective hepatocyte morphogenesis. As a result, abnormal epithelial structures expressing hepatocyte and cholangiocyte markers or resembling ectopic bile ducts developed in the Prox1-deficient liver parenchyma. By contrast, excessive commitment of hepatoblasts into cholangiocytes, premature intrahepatic bile duct morphogenesis, and biliary hyperplasia occurred in periportal areas of Prox1-deficient livers. Together, these abnormalities indicate that Prox1 activity is necessary to correctly allocate cell fates in liver precursors. These results increase our understanding of differentiation anomalies in pathological conditions and will contribute to improving stem cell protocols in which differentiation is directed towards hepatocytes and cholangiocytes. PMID:24449835

  18. Maternal undernutrition leads to elevated hepatic triglycerides in male rat offspring due to increased expression of lipoprotein lipase.

    PubMed

    Zhu, Wei-Fen; Zhu, Jian-Fang; Liang, Li; Shen, Zheng; Wang, Ying-Min

    2016-05-01

    Small for gestational age (SGA) at birth increases the risk of developing metabolic syndrome, which encompasses various symptoms including hypertriglyceridemia. The aim of the present study was to determine whether maternal undernutrition during pregnancy may lead to alterations in hepatic triglyceride content and the gene expression levels of hepatic lipoprotein lipase (LPL) in SGA male offspring. The present study focused on the male offspring in order to prevent confounding factors, such as estrus cycle and hormone profile. Female Sprague Dawley rats were arbitrarily assigned to receive an ad libitum chow diet or 50% food restricted diet from pregnancy day 1 until parturition. Reverse transcription quantitative polymerase chain reaction and western blot analysis were used to measure the gene expression levels of hepatic LPL at day 1 and upon completion of the third week of age. Chromatin immunoprecipitation quantified the binding activity of liver X receptor‑α (LXR‑α) gene to the LXR response elements (LXRE) on LPL promoter and LPL epigenetic characteristics. At 3 weeks of age, SGA male offspring exhibited significantly elevated levels of hepatic triglycerides, which was concomitant with increased expression levels of LPL. Since LPL is regulated by LXR‑α, the expression levels of LXR‑α were detected in appropriate for gestational age and SGA male offspring. Maternal undernutrition during pregnancy led to an increase in the hepatic expression levels of LXR‑α, and enriched binding to the putative LXR response elements in the LPL promoter regions in 3‑week‑old male offspring. In addition, enhanced acetylation of histone H3 [H3 lysine (K)9 and H3K14] was detected surrounding the LPL promoter. The results of the present study indicated that maternal undernutrition during pregnancy may lead to an increase in hepatic triglycerides, via alterations in the transcriptional and epigenetic regulation of the LPL gene.

  19. Hepatitis B virus X protein activates human hepatic stellate cells through upregulating TGFβ1.

    PubMed

    Chen, H-Y; Chen, Z-X; Huang, R-F; Lin, N; Wang, X-Z

    2014-10-27

    We investigated the effects of the hepatitis B virus X gene (HBV X) on the activation of human hepatic stellate cells (HSCs) and the possible mechanisms underlying the pathway. Recombinant plasmid pHBV-X-IRES2-EGFP was constructed and transfected into HL-7702 cells using a lipid-mediated method. Transfected cells were screened by G418, which detected stable expression of the X gene by reverse transcription (RT)-PCR and Western blot analysis, and named L02/x. Cells not subjected to G418-selection were analyzed to confirm the transient expression of the X gene and named L02/48x. Subsequently, L02/x and L02/48x, together with non-HBx-expressing cells, were co-cultured with HSCs in a non-contact transwell system. After 36 h of co-culture, the proliferation and migration of HSCs was detected using different cell counting methods. Finally, the mRNA and protein levels of α-SMA, Col I, and TGFβ1 in HSCs were detected by real-time PCR and western blot analysis. RT-PCR and Western blot analysis showed that L02/x and L02/48x cells can express HBV X gene mRNA and protein. Additionally, HSCs co-cultured with L02/x or L02/48x cells showed significantly higher proliferation and migration levels than control groups. Real-time PCR and Western blot analysis showed that the mRNA and protein expressions of α-SMA, Col I, and TGFβ1 in HSCs co-cultured with HBx-expressing liver cells were higher than those in control groups. HBx protein activated HSCs in vitro, leading to increased proliferation and migration of HSCs and upregulation of α-SMA and Col I. The TGFβ1 gene may be involved in this pathway.

  20. Activation of the aryl hydrocarbon receptor induces hepatic steatosis via the upregulation of fatty acid transport.

    PubMed

    Kawano, Yuki; Nishiumi, Shin; Tanaka, Shinwa; Nobutani, Kentaro; Miki, Akira; Yano, Yoshihiko; Seo, Yasushi; Kutsumi, Hiromu; Ashida, Hitoshi; Azuma, Takeshi; Yoshida, Masaru

    2010-12-15

    The aryl hydrocarbon receptor (AHR) is a basic helix-loop-helix/Per-ARNT-Sim domain transcription factor, which is activated by various xenobiotic ligands. AHR is known to be abundant in liver tissue and to be associated with hepatic steatosis. However, it has not yet been elucidated how the activation of AHR promotes hepatic steatosis. The aim of this study is to clarify the role of AHR in hepatic steatosis. The intraperitoneal injection of 3-methylcholanthrene (3MC), a potent AHR ligand, into C57BL/6J mice significantly increased the levels of triglycerides and six long-chain monounsaturated fatty acids in the livers of mice, resulting in hepatic microvesicular steatosis. 3MC significantly enhanced the expression level of fatty acid translocase (FAT), a factor regulating the uptake of long-chain fatty acids into hepatocytes, in the liver. In an in vitro experiment using human hepatoma HepG2 cells, 3MC increased the expression level of FAT, and the downregulation of AHR by AHR siRNA led to the suppression of 3MC-induced FAT expression. In addition, the mRNA level of peroxisome proliferator-activated receptor (PPAR) α, an upstream factor of FAT, was increased in the livers of 3MC-treated mice. Taking together, AHR activation induces hepatic microvesicular steatosis by increasing the expression level of FAT.

  1. Increased Very Low Density Lipoprotein Secretion, Hepatic Steatosis, and Insulin Resistance

    PubMed Central

    Choi, Sung Hee; Ginsberg, Henry N

    2011-01-01

    Insulin resistance (IR) not only affects regulation of carbohydrate metabolism, but all aspects of lipid and lipoprotein metabolism. IR is associated with increased secretion of very low density lipoproteins (VLDL) and increased plasma triglycerides, as well as hepatic steatosis, despite the increased VLDL secretion. Here, we link IR with increased VLDL secretion and hepatic steatosis at both the physiologic and molecular levels. Increased VLDL secretion, together with the downstream effects on high density lipoprotein cholesterol and low density lipoprotein size is pro-atherogenic. Hepatic steatosis is a risk for steatohepatitis and cirrhosis. Understanding the complex inter-relationship between IR and these abnormalities of liver lipid homeostasis may provide insights relevant to new therapies for these increasing clinical problems. PMID:21616678

  2. Increase in hepatic expression of SREBP-2 by gemfibrozil administration to rats.

    PubMed

    Roglans, N; Peris, C; Verd, J C; Alegret, M; Vázquez, M; Sánchez, R M; Laguna, J C

    2001-09-15

    It is well known that gemfibrozil increases the biliary output of cholesterol and phospholipids, but we have little knowledge about the impact these changes have on liver cholesterol and phospholipid biosynthetic pathways. In the present study, no changes were detected in liver lipids and CTP:phosphocholine cytidylyltransferase after gemfibrozil administration to rats. On the contrary, 3-hydroxy-3-methylglutaryl-CoA reductase mRNA (9.9-fold) and Rd activity (16.7-fold) and phosphatidate phosphohydrolase activity (1.7-fold) increased, while plasma apo B-cholesterol (40%) and triglyceride (43%) levels decreased. As a part of a compensatory homeostatic response, we report for the first time that gemfibrozil administration to rats increased the hepatic sterol regulatory element binding protein-2 (SREBP-2) mRNA (2.9-fold) and mature protein (2.2-fold) levels. An early increase in the transcriptional activity of SREBP-2 elicited by gemfibrozil administration might be responsible for the observed changes in HMG-CoA reductase, phosphatidate phosphohydrolase, and SREBP-2 expression.

  3. Effect of stress on hepatic 11beta-hydroxysteroid dehydrogenase activity and its influence on carbohydrate metabolism.

    PubMed

    Altuna, María Eugenia; Lelli, Sandra Marcela; San Martín de Viale, Leonor C; Damasco, María Cristina

    2006-10-01

    Stress activates the synthesis and secretion of catecholamines and adrenal glucocorticoids, increasing their circulating levels. In vivo, hepatic 11beta-hydroxysteroid dehydrogenase 1 (HSD1) stimulates the shift of 11-dehydrocorticosterone to corticosterone, enhancing active glucocorticoids at tissue level. We studied the effect of 3 types of stress, 1 induced by bucogastric overload with 200 mmol/L HCl causing metabolic acidosis (HCl), the second induced by bucogastric overload with 0.45% NaCl (NaCl), and the third induced by simulated overload (cannula), on the kinetics of hepatic HSD1 of rats and their influence on the activity of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase, glycemia, and glycogen deposition. Compared with unstressed controls, all types of stress significantly increased HSD1 activity (146% cannula, 130% NaCl, and 253% HCl), phosphoenolpyruvate carboxykinase activity (51% cannula, 48% NaCl, and 86% HCl), and glycemia (29% cannula, 30% NaCl, and 41% HCl), but decreased hepatic glycogen (68% cannula, 68% NaCl, and 78% HCl). Owing to these results, we suggest the following events occur when stress is induced: an increase in hepatic HSD1 activity, augmented active glucocorticoid levels, increased gluconeogenesis, and glycemia. Also involved are the multiple events indirectly related to glucocorticoids, which lead to the depletion of hepatic glycogen deposits, thereby contributing to increased glycemia. This new approach shows that stress increments the activity of hepatic HSD1 and suggests that this enzyme could be involved in the development of the Metabolic Syndrome.

  4. Angiotensin Receptor Blockade Recovers Hepatic UCP2 Expression and Aconitase and SDH Activities and Ameliorates Hepatic Oxidative Damage in Insulin Resistant Rats

    PubMed Central

    Montez, Priscilla; Vázquez-Medina, José Pablo; Rodríguez, Rubén; Thorwald, Max A.; Viscarra, José A.; Lam, Lisa; Peti-Peterdi, Janos; Nakano, Daisuke; Nishiyama, Akira

    2012-01-01

    Metabolic syndrome (MetS) is commonly associated with elevated renin-angiotensin system, oxidative stress, and steatohepatitis with down-regulation of uncoupling proteins (UCPs). However, the mechanisms linking renin-angiotensin system, steatosis, and UCP2 to hepatic oxidative damage during insulin resistance are not described. To test the hypothesis that angiotensin receptor activation contributes to decreased hepatic UCP2 expression and aconitase activity and to increased oxidative damage after increased glucose intake in a model of MetS, lean and obese Long Evans rats (n = 10/group) were randomly assigned to the following groups: 1) untreated Long Evans Tokushima Otsuka (lean, strain control), 2) untreated Otsuka Long Evans Tokushima Fatty (OLETF) (MetS model), 3) OLETF + angiotensin receptor blocker (ARB) (10 mg olmesartan/kg·d × 6 wk), 4) OLETF + high glucose (HG) (5% in drinking water × 6 wk), and 5) OLETF + ARB + HG (ARB/HG × 6 wk). HG increased body mass (37%), plasma triglycerides (TGs) (35%), plasma glycerol (87%), plasma free fatty acids (28%), and hepatic nitrotyrosine (74%). ARB treatment in HG decreased body mass (12%), plasma TG (15%), plasma glycerol (23%), plasma free fatty acids (14%), and hepatic TG content (42%), suggesting that angiotensin receptor type 1 (AT1) activation and increased adiposity contribute to the development of obesity-related dyslipidemia. ARB in HG also decreased hepatic nitrotyrosine and increased hepatic UCP2 expression (59%) and aconitase activity (40%), as well as antioxidant enzyme activities (50-120%), suggesting that AT1 activation also contributes to protein oxidation, impaired lipid metabolism, and antioxidant metabolism in the liver. Thus, in addition to promoting obesity-related hypertension, AT1 activation may also impair lipid metabolism and antioxidant capacity, resulting in steatosis via decreased UCP2 and tricarboxylic acid cycle activity. PMID:23087176

  5. Angiotensin receptor blockade recovers hepatic UCP2 expression and aconitase and SDH activities and ameliorates hepatic oxidative damage in insulin resistant rats.

    PubMed

    Montez, Priscilla; Vázquez-Medina, José Pablo; Rodríguez, Rubén; Thorwald, Max A; Viscarra, José A; Lam, Lisa; Peti-Peterdi, Janos; Nakano, Daisuke; Nishiyama, Akira; Ortiz, Rudy M

    2012-12-01

    Metabolic syndrome (MetS) is commonly associated with elevated renin-angiotensin system, oxidative stress, and steatohepatitis with down-regulation of uncoupling proteins (UCPs). However, the mechanisms linking renin-angiotensin system, steatosis, and UCP2 to hepatic oxidative damage during insulin resistance are not described. To test the hypothesis that angiotensin receptor activation contributes to decreased hepatic UCP2 expression and aconitase activity and to increased oxidative damage after increased glucose intake in a model of MetS, lean and obese Long Evans rats (n = 10/group) were randomly assigned to the following groups: 1) untreated Long Evans Tokushima Otsuka (lean, strain control), 2) untreated Otsuka Long Evans Tokushima Fatty (OLETF) (MetS model), 3) OLETF + angiotensin receptor blocker (ARB) (10 mg olmesartan/kg·d × 6 wk), 4) OLETF + high glucose (HG) (5% in drinking water × 6 wk), and 5) OLETF + ARB + HG (ARB/HG × 6 wk). HG increased body mass (37%), plasma triglycerides (TGs) (35%), plasma glycerol (87%), plasma free fatty acids (28%), and hepatic nitrotyrosine (74%). ARB treatment in HG decreased body mass (12%), plasma TG (15%), plasma glycerol (23%), plasma free fatty acids (14%), and hepatic TG content (42%), suggesting that angiotensin receptor type 1 (AT1) activation and increased adiposity contribute to the development of obesity-related dyslipidemia. ARB in HG also decreased hepatic nitrotyrosine and increased hepatic UCP2 expression (59%) and aconitase activity (40%), as well as antioxidant enzyme activities (50-120%), suggesting that AT1 activation also contributes to protein oxidation, impaired lipid metabolism, and antioxidant metabolism in the liver. Thus, in addition to promoting obesity-related hypertension, AT1 activation may also impair lipid metabolism and antioxidant capacity, resulting in steatosis via decreased UCP2 and tricarboxylic acid cycle activity.

  6. CCAAT/enhancer binding protein {beta} deletion increases mitochondrial function and protects mice from LXR-induced hepatic steatosis

    SciTech Connect

    Rahman, Shaikh M.; Choudhury, Mahua; Janssen, Rachel C.; Baquero, Karalee C.; Miyazaki, Makoto; Friedman, Jacob E.

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer LXR agonist activation increases liver TG accumulation by increasing lipogenesis. Black-Right-Pointing-Pointer C/EBP{beta}{sup -/-} mouse prevents LXR activation-mediated induction of hepatic lipogenesis. Black-Right-Pointing-Pointer C/EBP{beta} deletion increases mitochondrial transport chain function. Black-Right-Pointing-Pointer Beneficial effects of LXR activation on liver cholesterol metabolism did not change. Black-Right-Pointing-Pointer C/EBP{beta} inhibition might have important therapeutic potential. -- Abstract: Drugs designed specifically to activate liver X receptors (LXRs) have beneficial effects on lowering cholesterol metabolism and inflammation but unfortunately lead to severe hepatic steatosis. The transcription factor CCAAT/enhancer binding protein beta (C/EBP{beta}) is an important regulator of liver gene expression but little is known about its involvement in LXR-based steatosis and cholesterol metabolism. The present study investigated the role of C/EBP{beta} expression in LXR agonist (T0901317)-mediated alteration of hepatic triglyceride (TG) and lipogenesis in mice. C/EBP{beta} deletion in mice prevented LXR agonist-mediated induction of lipogenic gene expression in liver in conjunction with significant reduction of liver TG accumulation. Surprisingly, C/EBP{beta}{sup -/-} mice showed a major increase in liver mitochondrial electron chain function compared to WT mice. Furthermore, LXR activation in C/EBP{beta}{sup -/-} mice increased the expression of liver ATP-binding cassette transporter ABCG1, a gene implicated in cholesterol efflux and reducing blood levels of total and LDL-cholesterol. Together, these findings establish a central role for C/EBP{beta} in the LXR-mediated steatosis and mitochondrial function, without impairing the influence of LXR activation on lowering LDL and increasing HDL-cholesterol. Inactivation of C/EBP{beta} might therefore be an important therapeutic strategy to prevent LXR

  7. Erythropoietin alleviates hepatic insulin resistance via PPARγ-dependent AKT activation

    PubMed Central

    Ge, Zhijuan; Zhang, Pengzi; Hong, Ting; Tang, Sunyinyan; Meng, Ran; Bi, Yan; Zhu, Dalong

    2015-01-01

    Erythropoietin (EPO) has beneficial effects on glucose metabolism and insulin resistance. However, the mechanism underlying these effects has not yet been elucidated. This study aimed to investigate how EPO affects hepatic glucose metabolism. Here, we report that EPO administration promoted phosphatidylinositol 3-kinase (PI3K)/AKT pathway activation in palmitic acid (PA)-treated HepG2 cells and in the liver of high-fat diet (HFD)-fed mice, whereas adenovirus-mediated silencing of the erythropoietin receptor (EPOR) blocked EPO-induced AKT signalling in HepG2 cells. Importantly, a peroxisome proliferator-activated receptor γ (PPARγ) antagonist and PPARγ small interfering RNA (siRNA) abrogated the EPO-induced increase in p-AKT in HepG2 cells. Lentiviral vector-mediated hepatic PPARγ silencing in HFD-fed C57BL/6 mice impaired EPO-mediated increases in glucose tolerance, insulin sensitivity and hepatic AKT activation. Furthermore, EPO activated the AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) signalling pathway, and AMPKα and SIRT1 knockdown each attenuated the EPO-induced PPARγ expression and deacetylation and PPARγ-dependent AKT activation in HepG2 cells. In summary, these findings suggest that PPARγ is involved in EPO/EPOR-induced AKT activation, and targeting the PPARγ/AKT pathway via EPO may have therapeutic implications for hepatic insulin resistance and type 2 diabetes. PMID:26643367

  8. Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

    SciTech Connect

    Zan, Yanlu; Zhang, Yuxia; Tien, Po

    2013-06-07

    Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs.

  9. Increase in composite binder activity

    NASA Astrophysics Data System (ADS)

    Fediuk, R.; Smoliakov, A.; Stoyushko, N.

    2016-11-01

    The binder of portland cement (51-59 wt.%), fly ash of thermal power stations (3644 wt.%), limestone crushing waste (4-9 wt.%) and dry hyper plasticizer (0.2 wt.%) has been created. It can be used in the building materials industry for production of high-strength concrete. The composite binder is obtained by co-milling of the components in vario-planetary mill to a specific surface area of 550-600 m2/kg. The technical result is the possibility of obtaining a composite binder with significant replacement of cement with industrial waste, cost-effective and superior to portland cement for construction and technical properties, increased activity. This allows producing concrete for walling with a compressive strength of 100 MPa, while using more than 50% of industrial waste.

  10. Whole-Body Vibration Partially Reverses Aging-Induced Increases in Visceral Adiposity and Hepatic Lipid Storage in Mice

    PubMed Central

    van Dijk, Theo H.; Havinga, Rick; van der Zee, Eddy A.; Groen, Albert K.; Reijngoud, Dirk-Jan; Bakker, Barbara M.; van Dijk, Gertjan

    2016-01-01

    At old age, humans generally have declining muscle mass and increased fat deposition, which can increase the risk of developing cardiometabolic diseases. While regular physical activity postpones these age-related derangements, this is not always possible in the elderly because of disabilities or risk of injury. Whole-body vibration (WBV) training may be considered as an alternative to physical activity particularly in the frail population. To explore this possibility, we characterized whole-body and organ-specific metabolic processes in 6-month and 25-month old mice, over a period of 14 weeks of WBV versus sham training. WBV training tended to increase blood glucose turnover rates and stimulated hepatic glycogen utilization during fasting irrespective of age. WBV was effective in reducing white fat mass and hepatic triglyceride content only in old but not in young mice and these reductions were related to upregulation of hepatic mitochondrial uncoupling of metabolism (assessed by high-resolution respirometry) and increased expression of uncoupling protein 2. Because these changes occurred independent of changes in food intake and whole-body metabolic rate (assessed by indirect calorimetry), the liver-specific effects of WBV may be a primary mechanism to improve metabolic health during aging, rather than that it is a consequence of alterations in energy balance. PMID:26886917

  11. Thrombin activation and liver inflammation in advanced hepatitis C virus infection

    PubMed Central

    González-Reimers, Emilio; Quintero-Platt, Geraldine; Martín-González, Candelaria; Pérez-Hernández, Onán; Romero-Acevedo, Lucía; Santolaria-Fernández, Francisco

    2016-01-01

    Hepatitis C virus (HCV) infection is associated with increased thrombotic risk. Several mechanisms are involved including direct endothelial damage by the HCV virus, with activation of tissue factor, altered fibrinolysis and increased platelet aggregation and activation. In advanced stages, chronic HCV infection may evolve to liver cirrhosis, a condition in which alterations in the portal microcirculation may also ultimately lead to thrombin activation, platelet aggregation, and clot formation. Therefore in advanced HCV liver disease there is an increased prevalence of thrombotic phenomena in portal vein radicles. Increased thrombin formation may activate hepatic stellate cells and promote liver fibrosis. In addition, ischemic changes derived from vascular occlusion by microthrombi favor the so called parenchymal extinction, a process that promotes collapse of hepatocytes and the formation of gross fibrous tracts. These reasons may explain why advanced HCV infection may evolve more rapidly to end-stage liver disease than other forms of cirrhosis. PMID:27182154

  12. False positive hepatitis C antibody test results in left ventricular assist device recipients: increased risk with age and transfusions.

    PubMed

    Minamoto, Grace Y; Lee, Doreen; Colovai, Adriana; Levy, Dana; Vasovic, Ljiljana; Roach, Keith W; Shuter, Jonathan; Goldstein, Daniel; D'Alessandro, David; Jorde, Ulrich P; Muggia, Victoria A

    2017-01-01

    Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center. FPHC patients were identified as those with post-LVAD positive hepatitis C ELISA antibody tests and negative confirmatory testing with hepatitis C RNA PCR and/or radioimmunoblot assay. Ten (26%) patients previously seronegative for hepatitis C were found to have FPHC after device placement. Of the 39 patients, 32 had HeartMate II devices. The mean age at LVAD placement was 55 years. FPHC correlated with older age at the time of LVAD implantation and with receipt of packed red blood cell transfusions, but not with gender, fresh frozen plasma transfusions, panel reactive antibodies, globulin fraction, rheumatoid factor, or anticardiolipin antibodies. Clinicians should be aware of this increased risk of FPHC in older LVAD patients and those more heavily transfused in order to avoid unnecessary apprehension and possible delay in transplantation. Further studies should be done to evaluate the possible relationship between transfused blood products and immunomodulation.

  13. False positive hepatitis C antibody test results in left ventricular assist device recipients: increased risk with age and transfusions

    PubMed Central

    Lee, Doreen; Colovai, Adriana; Levy, Dana; Vasovic, Ljiljana; Roach, Keith W.; Shuter, Jonathan; Goldstein, Daniel; D’Alessandro, David; Jorde, Ulrich P.; Muggia, Victoria A.

    2017-01-01

    Left ventricular assist devices (LVADs) have been successfully used in patients with heart failure. However, LVADs may trigger immune activation, leading to higher frequencies of autoantibodies. We describe the clinical, epidemiological, and laboratory characteristics of LVAD recipients with false positive hepatitis C (FPHC) serology among 39 consecutive adult LVAD recipients who bridged to heart transplantation from January 2007 to January 2013 at Montefiore Medical Center. FPHC patients were identified as those with post-LVAD positive hepatitis C ELISA antibody tests and negative confirmatory testing with hepatitis C RNA PCR and/or radioimmunoblot assay. Ten (26%) patients previously seronegative for hepatitis C were found to have FPHC after device placement. Of the 39 patients, 32 had HeartMate II devices. The mean age at LVAD placement was 55 years. FPHC correlated with older age at the time of LVAD implantation and with receipt of packed red blood cell transfusions, but not with gender, fresh frozen plasma transfusions, panel reactive antibodies, globulin fraction, rheumatoid factor, or anticardiolipin antibodies. Clinicians should be aware of this increased risk of FPHC in older LVAD patients and those more heavily transfused in order to avoid unnecessary apprehension and possible delay in transplantation. Further studies should be done to evaluate the possible relationship between transfused blood products and immunomodulation. PMID:28203425

  14. Lipoprotein electrostatic properties regulate hepatic lipase association and activity.

    PubMed

    Boucher, Jonathan G; Nguyen, Trang; Sparks, Daniel L

    2007-12-01

    The effect of lipoprotein electrostatic properties on the catalytic regulation of hepatic lipase (HL) was investigated. Enrichment of serum or very low density lipoprotein (VLDL) with oleic acid increased lipoprotein negative charge and stimulated lipid hydrolysis by HL. Similarly, enrichment of serum or isolated lipoproteins with the anionic phospholipids phosphatidylinositol (PI), phosphatidic acid, or phosphatidylserine also increased lipoprotein negative charge and stimulated hydrolysis by HL. Anionic lipids had a small effect on phospholipid hydrolysis, but significantly stimulated triacylglyceride (TG) hydrolysis. High density lipoprotein (HDL) charge appears to have a specific effect on lipolysis. Enrichment of HDL with PI significantly stimulated VLDL-TG hydrolysis by HL. To determine whether HDL charge affects the association of HL with HDL and VLDL, HL-lipoprotein interactions were probed immunochemically. Under normal circumstances, HL associates with HDL particles, and only small amounts bind to VLDL. PI enrichment of HDL blocked the binding of HL with HDL. These data indicate that increasing the negative charge of HDL stimulates VLDL-TG hydrolysis by reducing the association of HL with HDL. Therefore, HDL controls the hydrolysis of VLDL by affecting the interlipoprotein association of HL. Lipoprotein electrostatic properties regulate lipase association and are an important regulator of the binding and activity of lipolytic enzymes.

  15. Effects of petroleum on adrenocortical activity and on hepatic naphthalene-metabolizing activity in mallard ducks

    USGS Publications Warehouse

    Gorsline, J.; Holmes, W.N.

    1981-01-01

    Unstressed mallard ducks (Anas platyrhychos), given uncontaminated food and maintained on a short photoperiod, show two daily maxima in plasma corticosterone concentration ([B]); one occurring early in the light phase and a second just before the onset of darkness. After one week of exposure to food containing 3% (v/w) South Louisiana crude oil, plasma [B] were significantly lowered throughout the day. Similar abrupt declines in plasma [B] also occurred during the first 10 days of exposure to food containing 1% and 0.5% crude oil. Although the plasma [B] in birds consuming food contaminated with 0.5% crude oil increased between 10 and 50 days of exposure, the concentration after 50 days was still lower than normal. During the same interval, normal plasma [B] were restored in birds consuming food containing 1% and 3% crude oil. Significant increases occurred in the naphthalene-metabolizing properties of hepatic microsomes prepared from birds acutely exposed to all levels of petroleum-contaminated food and elevated levels were sustained throughout the first 50 days of exposure. Birds given food containing 3% crude oil for more than 50 days, however, showed steady declines in hepatic naphthalene-metabolizing activity. After 500 days, the activity was similar to that found in contemporaneous controls. During the same interval, the plasma [B] increased until the levels were higher than normal after 500 days of exposure; at this time, an inverse relationship, similar to that seen during the first week of exposure to contaminated food, was once more established between plasma [B] and the concomitant hepatic naphthalene-metabolizing activity.

  16. Anti-hepatitis B activity of isoquinoline alkaloids of plant origin.

    PubMed

    Aljofan, Mohamad; Netter, Hans J; Aljarbou, Ahmed N; Hadda, Taibi Ben; Orhan, Ilkay Erdogan; Sener, Bilge; Mungall, Bruce A

    2014-05-01

    Hepatitis B virus (HBV) is the causative agent of B-type hepatitis in humans, a vaccine-preventable disease. Despite the availability of effective vaccines, globally, 2 billion people show evidence of past or current HBV infection, of which 350 million people are persistently infected, with an estimated annual increase of 1 million. There is no cure for chronic HBV infections, which are associated with cirrhotic liver failure and with an increased risk of developing hepatocellular carcinoma. Hepatitis antiviral research has focused primarily on the development of inhibitors of viral polymerase through the use of nucleoside analogues. Therefore, there is an urgent need for the development of non-nucleoside compounds to be used as an alternative or to complement the current therapy. To address this need, 18 isoquinoline alkaloids were evaluated for their potential antiviral activity against HBV in vitro.

  17. Propionate Increases Hepatic Pyruvate Cycling and Anaplerosis and Alters Mitochondrial Metabolism.

    PubMed

    Perry, Rachel J; Borders, Candace B; Cline, Gary W; Zhang, Xian-Man; Alves, Tiago C; Petersen, Kitt Falk; Rothman, Douglas L; Kibbey, Richard G; Shulman, Gerald I

    2016-06-03

    In mammals, pyruvate kinase (PK) plays a key role in regulating the balance between glycolysis and gluconeogenesis; however, in vivo regulation of PK flux by gluconeogenic hormones and substrates is poorly understood. To this end, we developed a novel NMR-liquid chromatography/tandem-mass spectrometry (LC-MS/MS) method to directly assess pyruvate cycling relative to mitochondrial pyruvate metabolism (VPyr-Cyc/VMito) in vivo using [3-(13)C]lactate as a tracer. Using this approach, VPyr-Cyc/VMito was only 6% in overnight fasted rats. In contrast, when propionate was infused simultaneously at doses previously used as a tracer, it increased VPyr-Cyc/VMito by 20-30-fold, increased hepatic TCA metabolite concentrations 2-3-fold, and increased endogenous glucose production rates by 20-100%. The physiologic stimuli, glucagon and epinephrine, both increased hepatic glucose production, but only glucagon suppressed VPyr-Cyc/VMito These data show that under fasting conditions, when hepatic gluconeogenesis is stimulated, pyruvate recycling is relatively low in liver compared with VMito flux and that liver metabolism, in particular pyruvate cycling, is sensitive to propionate making it an unsuitable tracer to assess hepatic glycolytic, gluconeogenic, and mitochondrial metabolism in vivo.

  18. Increased hepatic CD36 expression contributes to dyslipidemia associated with diet-induced obesity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The etiology of type 2 diabetes often involves diet-induced obesity (DIO), which is associated with elevated plasma fatty acids and lipoprotein associated triglycerides. Since aberrant hepatic fatty acid uptake may contribute to this, we investigated whether increased expression of a fatty acid tran...

  19. Propionate Increases Hepatic Pyruvate Cycling and Anaplerosis and Alters Mitochondrial Metabolism*

    PubMed Central

    Perry, Rachel J.; Borders, Candace B.; Cline, Gary W.; Zhang, Xian-Man; Alves, Tiago C.; Petersen, Kitt Falk; Rothman, Douglas L.; Kibbey, Richard G.; Shulman, Gerald I.

    2016-01-01

    In mammals, pyruvate kinase (PK) plays a key role in regulating the balance between glycolysis and gluconeogenesis; however, in vivo regulation of PK flux by gluconeogenic hormones and substrates is poorly understood. To this end, we developed a novel NMR-liquid chromatography/tandem-mass spectrometry (LC-MS/MS) method to directly assess pyruvate cycling relative to mitochondrial pyruvate metabolism (VPyr-Cyc/VMito) in vivo using [3-13C]lactate as a tracer. Using this approach, VPyr-Cyc/VMito was only 6% in overnight fasted rats. In contrast, when propionate was infused simultaneously at doses previously used as a tracer, it increased VPyr-Cyc/VMito by 20–30-fold, increased hepatic TCA metabolite concentrations 2–3-fold, and increased endogenous glucose production rates by 20–100%. The physiologic stimuli, glucagon and epinephrine, both increased hepatic glucose production, but only glucagon suppressed VPyr-Cyc/VMito. These data show that under fasting conditions, when hepatic gluconeogenesis is stimulated, pyruvate recycling is relatively low in liver compared with VMito flux and that liver metabolism, in particular pyruvate cycling, is sensitive to propionate making it an unsuitable tracer to assess hepatic glycolytic, gluconeogenic, and mitochondrial metabolism in vivo. PMID:27002151

  20. Increased Phosphoenolpyruvate Carboxykinase Gene Expression and Steatosis during Hepatitis C Virus Subgenome Replication

    PubMed Central

    Qadri, Ishtiaq; Choudhury, Mahua; Rahman, Shaikh Mizanoor; Knotts, Trina A.; Janssen, Rachel C.; Schaack, Jerome; Iwahashi, Mieko; Puljak, Livia; Simon, Francis R.; Kilic, Gordan; Fitz, J. Gregory; Friedman, Jacob E.

    2012-01-01

    Chronic hepatitis C virus (HCV) infection greatly increases the risk for type 2 diabetes and nonalcoholic steatohepatitis; however, the pathogenic mechanisms remain incompletely understood. Here we report gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) transcription and associated transcription factors are dramatically up-regulated in Huh.8 cells, which stably express an HCV subgenome replicon. HCV increased activation of cAMP response element-binding protein (CREB), CCAAT/enhancer-binding protein (C/EBPβ), forkhead box protein O1 (FOXO1), and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and involved activation of the cAMP response element in the PEPCK promoter. Infection with dominant-negative CREB or C/EBPβ-shRNA significantly reduced or normalized PEPCK expression, with no change in PGC-1α or FOXO1 levels. Notably, expression of HCV nonstructural component NS5A in Huh7 or primary hepatocytes stimulated PEPCK gene expression and glucose output in HepG2 cells, whereas a deletion in NS5A reduced PEPCK expression and lowered cellular lipids but was without effect on insulin resistance, as demonstrated by the inability of insulin to stimulate mobilization of a pool of insulin-responsive vesicles to the plasma membrane. HCV-replicating cells demonstrated increases in cellular lipids with insulin resistance at the level of the insulin receptor, increased insulin receptor substrate 1 (Ser-312), and decreased Akt (Ser-473) activation in response to insulin. C/EBPβ-RNAi normalized lipogenic genes sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor γ, and liver X receptor α but was unable to reduce accumulation of triglycerides in Huh.8 cells or reverse the increase in ApoB expression, suggesting a role for increased lipid retention in steatotic hepatocytes. Collectively, these data reveal an important role of NS5A, C/EBPβ, and pCREB in promoting HCV-induced gluconeogenic gene expression

  1. Hyperammonemia Is Associated with Increasing Severity of Both Liver Cirrhosis and Hepatic Encephalopathy

    PubMed Central

    Ayub, Maimoona; Khan, Wazir Mohammad

    2016-01-01

    Background. Hyperammonemia resulting from chronic liver disease (CLD) can potentially challenge and damage any organ system of the body, particularly the brain. However, there is still some controversy regarding the diagnostic or prognostic values of serum ammonia in patients with over hepatic encephalopathy, especially in the setting of acute-on-chronic or chronic liver failure. Moreover, the association of serum ammonia with worsening Child-Pugh grade of liver cirrhosis has not been studied. Objective. This study was conducted to solve the controversy regarding the association between hyperammonemia and cirrhosis, especially hepatic encephalopathy in chronically failed liver. Material and Methods. In this study, 171 cirrhotic patients had their serum ammonia measured and analyzed by SPSS version 16. Chi-squared test and one-way ANOVA were applied. Results. The study had 110 male and 61 female participants. The mean age of all the participants in years was 42.33 ± 7.60. The mean duration (years) of CLD was 10.15 ± 3.53 while the mean Child-Pugh (CP) score was 8.84 ± 3.30. Chronic viral hepatitis alone was responsible for 71.3% of the cases. Moreover, 86.5% of participants had hepatic encephalopathy (HE). The frequency of hyperammonemia was 67.3%, more frequent in males (N = 81, z-score = 2.4, and P < 0.05) than in females (N = 34, z-score = 2.4, and P < 0.05), and had a statistically significant relationship with increasing CP grade of cirrhosis (χ2(2) = 27.46, P < 0.001, Phi = 0.40, and P < 0.001). Furthermore, serum ammonia level was higher in patients with hepatic encephalopathy than in those without it; P < 0.001. Conclusion. Hyperammonemia is associated with both increasing Child-Pugh grade of liver cirrhosis and hepatic encephalopathy. PMID:27847646

  2. Increasing opportunities for physical activity.

    PubMed

    Buckley, Sue

    2007-07-01

    Being physically active can have a number of benefits - having fun, meeting with friends, keeping healthy and experiencing success. For children with Down syndrome the foundations need to be laid early if they are to keep active in school, teenage and adult years and parents ask for more help in this area from professionals.

  3. Hepatic CD206-positive macrophages express amphiregulin to promote the immunosuppressive activity of regulatory T cells in HBV infection.

    PubMed

    Dai, Kai; Huang, Ling; Sun, Xiaomei; Yang, Lihua; Gong, Zuojiong

    2015-12-01

    Hepatitis B virus is a major cause of chronic liver inflammation worldwide. Innate and adaptive immune responses work together to restrain or eliminate hepatitis B virus in the liver. Compromised or failed adaptive immune response results in persistent virus replication and spread. How to promote antiviral immunity is a research focus for hepatitis B virus prevention and therapy. In this study, we investigated the role of macrophages in the regulation of antiviral immunity. We found that F4/80(+)CD206(+)CD80(lo/+) macrophages were a particular hepatic macrophage subset that expressed amphiregulin in our mouse hepatitis B virus infection model. CD206(+) macrophage-derived amphiregulin promoted the immunosuppressive activity of intrahepatic regulatory T cells, demonstrated by higher expression of CTLA-4, ICOS, and CD39, as well as stronger inhibition of antiviral function of CD8(+) T cells. Amphiregulin-neutralizing antibody diminished the effect of CD206(+) macrophages on regulatory T cells. In addition, we found that CD206(+) macrophage-derived amphiregulin activated mammalian target of rapamycin signaling in regulatory T cells, and this mammalian target of rapamycin activation was essential for promotion of regulatory T cell activity by CD206(+) macrophages. Adoptive transfer of CD206(+) macrophages into hepatitis B virus-infected mice increased cytoplasmic hepatitis B virus DNA in hepatocytes and also increased serum hepatitis B surface antigen. The antiviral activity of CD8(+) T cells was decreased after macrophage transfer. Therefore, our research indicated that amphiregulin produced by CD206(+) macrophages plays an important role in modulating regulatory T cell function and subsequently restrains the antiviral activity of CD8(+) T cells. Our study offers new insights into the immunomodulation in hepatitis B virus infection.

  4. Apolipoprotein D Transgenic Mice Develop Hepatic Steatosis through Activation of PPARγ and Fatty Acid Uptake

    PubMed Central

    Labrie, Marilyne; Lalonde, Simon; Najyb, Ouafa; Thiery, Maxime; Daneault, Caroline; Des Rosiers, Chrisitne; Rassart, Eric; Mounier, Catherine

    2015-01-01

    Transgenic mice (Tg) overexpressing human apolipoprotein D (H-apoD) in the brain are resistant to neurodegeneration. Despite the use of a neuron-specific promoter to generate the Tg mice, they expressed significant levels of H-apoD in both plasma and liver and they slowly develop hepatic steatosis and insulin resistance. We show here that hepatic PPARγ expression in Tg mice is increased by 2-fold compared to wild type (WT) mice. Consequently, PPARγ target genes Plin2 and Cide A/C are overexpressed, leading to increased lipid droplets formation. Expression of the fatty acid transporter CD36, another PPARgamma target, is also increased in Tg mice associated with elevated fatty acid uptake as measured in primary hepatocytes. Elevated expression of AMPK in the liver of Tg leads to phosphorylation of acetyl CoA carboxylase, indicating a decreased activity of the enzyme. Fatty acid synthase expression is also induced but the hepatic lipogenesis measured in vivo is not significantly different between WT and Tg mice. In addition, expression of carnitine palmitoyl transferase 1, the rate-limiting enzyme of beta-oxidation, is slightly upregulated. Finally, we show that overexpressing H-apoD in HepG2 cells in presence of arachidonic acid (AA), the main apoD ligand, increases the transcriptional activity of PPARγ. Supporting the role of apoD in AA transport, we observed enrichment in hepatic AA and a decrease in plasmatic AA concentration. Taken together, our results demonstrate that the hepatic steatosis observed in apoD Tg mice is a consequence of increased PPARγ transcriptional activity by AA leading to increased fatty acid uptake by the liver. PMID:26083030

  5. Hepatic Mitochondrial Alterations and Increased Oxidative Stress in Nutritional Diabetes-Prone Psammomys obesus Model

    PubMed Central

    Bouderba, Saida; Sanz, M. Nieves; Sánchez-Martín, Carlos; El-Mir, M. Yehia; Villanueva, Gloria R.; Detaille, Dominique; Koceïr, E. Ahmed

    2012-01-01

    Mitochondrial dysfunction is considered to be a pivotal component of insulin resistance and associated metabolic diseases. Psammomys obesus is a relevant model of nutritional diabetes since these adult animals exhibit a state of insulin resistance when fed a standard laboratory chow, hypercaloric for them as compared to their natural food. In this context, alterations in bioenergetics were studied. Using liver mitochondria isolated from these rats fed such a diet for 18 weeks, oxygen consumption rates, activities of respiratory complexes, and content in cytochromes were examined. Levels of malondialdehyde (MDA) and gluthatione (GSH) were measured in tissue homogenates. Diabetic Psammomys showed a serious liver deterioration (hepatic mass accretion, lipids accumulation), accompanied by an enhanced oxidative stress (MDA increased, GSH depleted). On the other hand, both ADP-dependent and uncoupled respirations greatly diminished below control values, and the respiratory flux to cytochrome oxydase was mildly lowered. Furthermore, an inhibition of complexes I and III together with an activation of complex II were found. With emergence of oxidative stress, possibly related to a defect in oxidative phosphorylation, some molecular adjustments could contribute to alleviate, at least in part, the deleterious outcomes of insulin resistance in this gerbil species. PMID:22675340

  6. Endogenous n-3 Polyunsaturated Fatty Acids Attenuate T Cell-Mediated Hepatitis via Autophagy Activation

    PubMed Central

    Li, Yanli; Tang, Yuan; Wang, Shoujie; Zhou, Jing; Zhou, Jia; Lu, Xiao; Bai, Xiaochun; Wang, Xiang-Yang; Chen, Zhengliang; Zuo, Daming

    2016-01-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs) exert anti-inflammatory effects in several liver disorders, including cirrhosis, acute liver failure, and fatty liver disease. To date, little is known about their role in immune-mediated liver diseases. In this study, we used fat-1 transgenic mice rich in endogenous n-3 PUFAs to examine the role of n-3 PUFAs in immune-mediated liver injury. Concanavalin A (Con A) was administered intravenously to wild-type (WT) and fat-1 transgenic mice to induce T cell-mediated hepatitis. Reduced liver damage was shown in Con A-administrated fat-1 transgenic mice, as evidenced by decreased mortality, attenuated hepatic necrosis, lessened serum alanine aminotransferase activity, and inhibited production of pro-inflammatory cytokines (e.g., TNF-α, IL-6, IL-17A, and IFN-γ). In vivo and in vitro studies demonstrated that n-3 PUFAs significantly inhibited the activation of hepatic T cells and the differentiation of Th1 cells after Con A challenge. Further studies showed that n-3 PUFAs markedly increased autophagy level in Con A-treated fat-1 T cells compared with the WT counterparts. Blocking hepatic autophagy activity with chloroquine diminished the differences in T cell activation and liver injury between Con A-injected WT and fat-1 transgenic mice. We conclude that n-3 PUFAs limit Con A-induced hepatitis via an autophagy-dependent mechanism and could be exploited as a new therapeutic approach for autoimmune hepatitis. PMID:27679638

  7. Activation of the farnesoid X receptor induces hepatic expression and secretion of fibroblast growth factor 21.

    PubMed

    Cyphert, Holly A; Ge, Xuemei; Kohan, Alison B; Salati, Lisa M; Zhang, Yanqiao; Hillgartner, F Bradley

    2012-07-20

    Previous studies have shown that starvation or consumption of a high fat, low carbohydrate (HF-LC) ketogenic diet induces hepatic fibroblast growth factor 21 (FGF21) gene expression in part by activating the peroxisome proliferator-activated receptor-α (PPARα). Using primary hepatocyte cultures to screen for endogenous signals that mediate the nutritional regulation of FGF21 expression, we identified two sources of PPARα activators (i.e. nonesterified unsaturated fatty acids and chylomicron remnants) that induced FGF21 gene expression. In addition, we discovered that natural (i.e. bile acids) and synthetic (i.e. GW4064) activators of the farnesoid X receptor (FXR) increased FGF21 gene expression and secretion. The effects of bile acids were additive with the effects of nonesterified unsaturated fatty acids in regulating FGF21 expression. FXR activation of FGF21 gene transcription was mediated by an FXR/retinoid X receptor binding site in the 5'-flanking region of the FGF21 gene. FGF19, a gut hormone whose expression and secretion is induced by intestinal bile acids, also increased hepatic FGF21 secretion. Deletion of FXR in mice suppressed the ability of an HF-LC ketogenic diet to induce hepatic FGF21 gene expression. The results of this study identify FXR as a new signaling pathway activating FGF21 expression and provide evidence that FXR activators work in combination with PPARα activators to mediate the stimulatory effect of an HF-LC ketogenic diet on FGF21 expression. We propose that the enhanced enterohepatic flux of bile acids during HF-LC consumption leads to activation of hepatic FXR and FGF19 signaling activity and an increase in FGF21 gene expression and secretion.

  8. Increased liver pathology in hepatitis C virus transgenic mice expressing the hepatitis B virus X protein

    SciTech Connect

    Keasler, Victor V.; Lerat, Herve; Madden, Charles R.; Finegold, Milton J.; McGarvey, Michael J.; Mohammed, Essam M.A.; Forbes, Stuart J.; Lemon, Stanley M.; Hadsell, Darryl L.; Grona, Shala J.; Hollinger, F. Blaine; Slagle, Betty L. . E-mail: bslagle@bcm.edu

    2006-04-10

    Transgenic mice expressing the full-length HCV coding sequence were crossed with mice that express the HBV X gene-encoded regulatory protein HBx (ATX mice) to test the hypothesis that HBx expression accelerates HCV-induced liver pathogenesis. At 16 months (mo) of age, hepatocellular carcinoma was identified in 21% of HCV/ATX mice, but in none of the single transgenic animals. Analysis of 8-mo animals revealed that, relative to HCV/WT mice, HCV/ATX mice had more severe steatosis, greater liver-to-body weight ratios, and a significant increase in the percentage of hepatocytes staining for proliferating cell nuclear antigen. Furthermore, primary hepatocytes from HCV, ATX, and HCV/ATX transgenic mice were more resistant to fas-mediated apoptosis than hepatocytes from nontransgenic littermates. These results indicate that HBx expression contributes to increased liver pathogenesis in HCV transgenic mice by a mechanism that involves an imbalance in hepatocyte death and regeneration within the context of severe steatosis.

  9. MKR mice have increased dynamic glucose disposal despite metabolic inflexibility, and hepatic and peripheral insulin insensitivity

    PubMed Central

    Vaitheesvaran, B.; LeRoith, D.

    2014-01-01

    Aims/hypothesis Recent work has shown that there can be significant differences when glucose disposal is assessed for high-fat induced insulin resistance by static clamp methods vs dynamic assessment during a stable isotope i.p. glucose tolerance test. MKR mice, though lean, have severe insulin resistance and decreased muscle fatty acid oxidation. Our goal was to assess dynamic vs static glucose disposal in MKR mice, and to correlate glucose disposal and muscle–adipose–liver flux interactions with metabolic flexibility (indirect calorimetry) and muscle characteristics. Methods Stable isotope flux phenotyping was performed using [6,6-2H2]glucose, [U-13C6]glucose and [2-13C]glycerol. Muscle triacylglycerol (TAG) and diacylglycerol (DAG) content was assessed by thin layer chromatography, and histological determination of fibre type and cytochrome c activity performed. Metabolic flexibility was assessed by indirect calorimetry. Results Indirect calorimetry showed that MKR mice used more glucose than FVB/N mice during fasting (respiratory exchange ratio [RER] 0.88 vs 0.77, respectively). Compared with FVB/N mice, MKR mice had faster dynamic glucose disposal, despite increased whole-muscle DAG and TAG, and similar hepatic glucose production with higher fasting insulin and unchanged basal glucose. Fed MKR muscle had more glycogen, and increased levels of GLUT1 and GLUT4 than FVB/N muscle. Histology indicated that MKR soleus had mildly decreased cytochrome c activity overall and more type II (glycolytic) fibres compared with that in FVB/N mice. Conclusions/interpretation MKR muscle adapts to using glucose, with more type II fibres present in red muscle. Fasting RER is elevated and glucose disposal during an i.p. glucose tolerance test is accelerated despite increased muscle DAG and TAG. Metabolic inflexibility may result from the compensatory use of fuel that can be best utilised for energy requirements; static vs dynamic glucose disposal assessments may measure

  10. HCV core protein induces hepatic lipid accumulation by activating SREBP1 and PPAR{gamma}

    SciTech Connect

    Kim, Kook Hwan; Hong, Sung Pyo; Kim, KyeongJin; Park, Min Jung; Kim, Kwang Jin; Cheong, JaeHun . E-mail: molecule85@pusan.ac.kr

    2007-04-20

    Hepatic steatosis is a common feature in patients with chronic hepatitis C virus (HCV) infection. HCV core protein plays an important role in the development of hepatic steatosis in HCV infection. Because SREBP1 (sterol regulatory element binding protein 1) and PPAR{gamma} (peroxisome proliferators-activated receptor {gamma}) are involved in the regulation of lipid metabolism of hepatocyte, we sought to determine whether HCV core protein may impair the expression and activity of SREBP1 and PPAR{gamma}. In this study, it was demonstrated that HCV core protein increases the gene expression of SREBP1 not only in Chang liver, Huh7, and HepG2 cells transiently transfected with HCV core protein expression plasmid, but also in Chang liver-core stable cells. Furthermore, HCV core protein enhanced the transcriptional activity of SREBP1. In addition, HCV core protein elevated PPAR{gamma} transcriptional activity. However, HCV core protein had no effect on PPAR{gamma} gene expression. Finally, we showed that HCV core protein stimulates the genes expression of lipogenic enzyme and fatty acid uptake associated protein. Therefore, our finding provides a new insight into the mechanism of hepatic steatosis by HCV infection.

  11. Cholesterol overloading leads to hepatic L02 cell damage through activation of the unfolded protein response.

    PubMed

    Li, Qi; Liu, Zhiguo; Guo, Jianli; Chen, Jiangyuan; Yang, Pu; Tian, Jun; Sun, Jun; Zong, Yiqiang; Qu, Shen

    2009-10-01

    Reported data indicate that cholesterol loading in the liver can cause hepatic injury. To explore the possible mechanisms of cell damage resulting from cholesterol overloading in hepatocytes, cell apoptosis, the unfolded protein response (UPR) and the correlation between them were assessed in the cholesterol-overloaded normal human hepatic cell line L02. L02 cells were incubated with 200 microg/ ml of low density lipoprotein (LDL) for 24 h with or without 20 microg/ml 58035, an inhibitor of acyl-CoA:cholesterol acyltransferase (ACAT). In the LDL+58035 group, the intracellular cholesterol level was dramatically increased, which was measured by an enzymatic combined high performance liquid chromatography assay. Expression of immunoglobulin-binding protein, X-box binding protein 1, activating transcription factor 6, activating transcription factor 4, CCAAT/enhancer-binding protein homologous protein-10, markers of endoplasmic reticulum stress (ERS)/ UPR, were up-regulated as determined using reverse transcription-polymerase chain reaction (RT-PCR) or Western blot analysis. The rate of cell apoptic death increased 21.3+/-2.4%. Meanwhile, the active caspase-3 protein expression was increased 8.4-fold compared to the active caspase-3 protein expression in the controls. Furthermore, 4-phenylbutyric acid, an inhibitor of UPR, partly reduced cell apoptosis and activation of caspase-3. This study suggests that cholesterol overloading in hepatic L02 cells induces ERS and activates the UPR which, in part, leads to the apoptotic damage of cells.

  12. Hepatic FTO expression is increased in NASH and its silencing attenuates palmitic acid-induced lipotoxicity.

    PubMed

    Lim, Andrea; Zhou, Jin; Sinha, Rohit A; Singh, Brijesh K; Ghosh, Sujoy; Lim, Kiat-Hon; Chow, Pierce Kah-Hoe; Woon, Esther C Y; Yen, Paul M

    2016-10-21

    Non-alcoholic steatohepatitis (NASH) is one of the most common causes of liver failure worldwide. It is characterized by excess fat accumulation, inflammation, and increased lipotoxicity in hepatocytes. Currently, there are limited treatment options for NASH due to lack of understanding of its molecular etiology. In the present study, we demonstrate that the expression of fat mass and obesity associated gene (FTO) is significantly increased in the livers of NASH patients and in a rodent model of NASH. Furthermore, using human hepatic cells, we show that genetic silencing of FTO protects against palmitate-induced oxidative stress, mitochondrial dysfunction, ER stress, and apoptosis in vitro. Taken together, our results show that FTO may have a deleterious role in hepatic cells during lipotoxic conditions, and strongly suggest that up-regulation of FTO may contribute to the increased liver damage in NASH.

  13. Increased hepatic nicotine elimination after phenobarbital induction in the conscious rat

    SciTech Connect

    Foth, H.; Walther, U.I.; Kahl, G.F. )

    1990-09-15

    Elimination parameters of (14C)nicotine in conscious rats receiving nicotine (0.3 mg/kg) either intravenously or orally were studied. The oral availability of unchanged nicotine, derived by comparison of the respective areas under the concentration vs time curves (AUC), was 89%, indicating low hepatic extraction ratios of about 10%. Pretreatment of rats with phenobarbital (PB) markedly increased hepatic first-pass extraction of nicotine. The oral availability of unchanged nicotine in plasma dropped to 1.4% of the corresponding values obtained from PB-treated rats receiving nicotine iv. After PB pretreatment, the clearance of iv nicotine was increased approximately twofold over controls, much less than the observed more than ninefold increase of hepatic first-pass extraction. It is assumed that extrahepatic metabolism contributed significantly to the rapid removal of nicotine from the plasma. The elimination of cotinine, originating from nicotine administered either po or iv, was significantly increased by PB pretreatment, as determined by the ratio of corresponding AUCs. The pattern of nicotine metabolites in urine also indicated an increase in the rate of cotinine metabolic turnover. The amount of norcotinine in the organic extract of urine paralleled PB microsomal enzyme induction. The ratio between urinary concentrations of the normetabolite and cotinine correlated strongly with the PB-induced state of rat liver. This may be a suitable indicator of PB-inducible hepatic cytochrome P450 isoenzyme(s). Since smoking habits in man are feedback-regulated by nicotine plasma concentrations, a similar increase of nicotine elimination by microsomal enzyme induction in man may be of relevance for tobacco consumption.

  14. Increasing Youth Physical Activity with Activity Calendars

    ERIC Educational Resources Information Center

    Eckler, Seth

    2016-01-01

    Physical educators often struggle with ways to get their students to be active beyond the school day. One strategy to accomplish this is the use of physical activity calendars (PACs). The purpose of this article is to support the use of PACs and give practical advice for creating effective PACs.

  15. Acute Increase in Hepatic Arterial Flow During TIPS Identified by Intravascular Flow Measurements

    SciTech Connect

    Radeleff, Boris Sommer, Christof-Matthias; Heye, Tobias; Lopez-Benitez, Ruben; Sauer, Peter; Schmidt, Jan; Kauczor, Haus-Ulrich; Richter, Goetz Martin

    2009-01-15

    The purpose of this study was to investigate alterations of hepatic arterial flow during transjugular intrahepatic portosystemic stent shunt (TIPS) applying intravascular Doppler sonography. This prospective monocenter study included 25 patients with liver cirrhosis (alcohol induced [n = 19], chronic hepatitis associated [n = 3], primary biliary cirrhosis associated [n = 1], and cryptogenic [n = 2]) successfully treated with TIPS. All patients underwent intravascular hepatic arterial flow measurements during TIPS using an endoluminal flow sensor. The average arterial peak velocity (APV) and the maximum arterial peak velocity (MPV) were registered. Twenty-two patients (88%) showed increased APV, one patient (4%) showed unaffected APV, and two patients (8%) showed decreased APV after TIPS. The average portosystemic pressure gradient decreased significantly, from 22.0 {+-} 5.1 mmHg before TIPS to 11.0 {+-} 4.1 mmHg after TIPS (-50.0%; p < 0.0001). The average APV increased significantly, from 41.9 {+-} 17.8 cm/s before TIPS to 60.7 {+-} 19.0 cm/s after TIPS (+44.9%; p < 0.0001). The average MPV increased significantly, from 90.8 {+-} 31.7 cm/s before TIPS to 112.6 {+-} 34.9 cm/s after TIPS (+24.0%; p = 0.0002). These changes in perfusion set in within seconds after TIPS tract formation in all the patients with increased APV. We conclude that TIPS-induced portosystemic decompression leads to a significant increase in hepatic arterial flow. The changes occurred within seconds, suggesting a reflex-like mechanism.

  16. Fetal and neonatal exposure to nicotine leads to augmented hepatic and circulating triglycerides in adult male offspring due to increased expression of fatty acid synthase

    SciTech Connect

    Ma, Noelle; Nicholson, Catherine J.; Wong, Michael; Holloway, Alison C.; Hardy, Daniel B.

    2014-02-15

    While nicotine replacement therapy is assumed to be a safer alternative to smoking during pregnancy, the long-term consequences for the offspring remain elusive. Animal studies now suggest that maternal nicotine exposure during perinatal life leads to a wide range of adverse outcomes for the offspring including increased adiposity. The focus of this study was to investigate if nicotine exposure during pregnancy and lactation leads to alterations in hepatic triglyceride synthesis. Female Wistar rats were randomly assigned to receive daily subcutaneous injections of saline (vehicle) or nicotine bitartrate (1 mg/kg/day) for two weeks prior to mating until weaning. At postnatal day 180 (PND 180), nicotine exposed offspring exhibited significantly elevated levels of circulating and hepatic triglycerides in the male offspring. This was concomitant with increased expression of fatty acid synthase (FAS), the critical hepatic enzyme in de novo triglyceride synthesis. Given that FAS is regulated by the nuclear receptor Liver X receptor (LXRα), we measured LXRα expression in both control and nicotine-exposed offspring. Nicotine exposure during pregnancy and lactation led to an increase in hepatic LXRα protein expression and enriched binding to the putative LXRE element on the FAS promoter in PND 180 male offspring. This was also associated with significantly enhanced acetylation of histone H3 [K9,14] surrounding the FAS promoter, a hallmark of chromatin activation. Collectively, these findings suggest that nicotine exposure during pregnancy and lactation leads to an increase in circulating and hepatic triglycerides long-term via changes in the transcriptional and epigenetic regulation of the hepatic lipogenic pathway. - Highlights: • Our data reveals the links nicotine exposure in utero and long-term hypertriglyceridemia. • It is due to nicotine-induced augmented expression of hepatic FAS and LXRα activity. • Moreover, this involves nicotine-induced enhanced

  17. Puerarin ameliorates hepatic steatosis by activating the PPARα and AMPK signaling pathways in hepatocytes.

    PubMed

    Kang, Ok-Hwa; Kim, Sung-Bae; Mun, Su-Hyun; Seo, Yun-Soo; Hwang, Hyeong-Chil; Lee, Young-Mi; Lee, Ho-Seob; Kang, Dae-Gil; Kwon, Dong-Yeul

    2015-03-01

    Non-alcoholic fatty liver disease (NAFLD) is characterized by the hepatic manifestation of metabolic syndrome and is the leading cause of chronic liver disease. Steatohepatitis plays a critical role in the process resulting in liver fibrosis and cirrhosis. Puerarin is a herbal product widely used in Asia, and is believed to have therapeutic benefits for alleviating the symptoms of steatohepatitis. The present study was designed to investigate the effects and mechanisms of action of puerarin in reducing lipid accumulation in oleic acid (OA)-treated HepG2 cells. Hepatocytes were treated with OA with or without puerarin to observe lipid accumulation by Oil Red O staining. We also examined hepatic lipid contents (e.g., triacylglycerol and cholesterol) following treatment with puerarin. Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) were used to measure sterol regulatory element binding protein (SREBP)-1, fatty acid synthase (FAS), peroxisome proliferator-activated receptor α (PPARα) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) protein and mRNA expression, respectively. Our results revealed that puerarin suppressed OA-induced lipid accumulation, and reduced the triacylglycerol and cholesterol levels. Furthermore, puerarin decreased the expression levels of lipogenic enzymes, such as FAS and SREBPs, and increased the expression levels of PPARα, which are critical regulators of hepatic lipid metabolism through the AMPK signaling pathway. These results indicate that puerarin has the same ability to activate AMPK, and reduce SREBP-1 and FAS expression, thus inhibiting hepatic lipogenesis and increasing hepatic antioxidant activity. We found that puerarin exerted a regulatory effect on lipid accumulation by decreasing lipogenesis in hepatocytes. Therefore, puerarin extract may have therapeutic benefits in the treatment of fatty liver and lipid-related metabolic disorders.

  18. Individual variation in hepatic aldehyde oxidase activity.

    PubMed

    Al-Salmy, H S

    2001-04-01

    Aldehyde oxidase (AO) is a molybdo-flavo enzyme expressed predominantly in the liver, lung, and kidney. AO plays a major role in oxidation of aldehydes, as well as oxidation of various N-heterocyclic compounds of pharmacological and toxicological importance including antiviral (famciclovir), antimalarial (quinine), antitumour (methotrexate), and nicotine. The aim of this study was to investigate cytosolic aldehyde oxidase activity in human liver. Cytosolic AO was characterised using both the metabolism of N-[(2-dimethylamino)ethyl] acridine-4-carboxamide (DACA) and benzaldehyde to form DACA-9(10H)-acridone (quantified by HPLC with fluorescence detection) and benzoic acid (quantified spectrophotometrically). Thirteen livers (10 female, 3 male) were examined. The intrinsic clearance (Vmax/Km) of DACA varied 18-fold (0.03-0.50 m/min/mg). Vmax ranged from 0.20-3.10 nmol/ min/mg, and Km ranged from 3.5-14.2 microM. In the same specimens, the intrinsic clearance for benzaldehyde varied 5-fold (0.40-1.8 ml/min/mg). Vmax ranged from 3.60-12.6 nmol/min/mg and Km ranged from 3.6-14.6 microM. Furthermore, there were no differences in AO activity between male and female human livers, nor was there any relationship to age of donor (range 29-73 years), smoking status, or disease status. In conclusion, our results showed that there are variations in AO activity in human liver. These variations in aldehyde oxidase activity might reflect individual variations or they might be due to AO stability during processing and storage.

  19. Miltefosine Suppresses Hepatic Steatosis by Activating AMPK Signal Pathway

    PubMed Central

    Zhu, Yaqin; Tong, Xing; Li, Kexue; Bai, Hui; Li, Xiaoyu; Ben, Jingjing; Zhang, Hanwen; Yang, Qing; Chen, Qi

    2016-01-01

    Background and Purpose It has been accepted that AMPK (Adenosine monophosphate–activated protein kinase) activation exhibits many beneficial effects on glucolipid metabolism. Lysophosphatidylcholine (LPC) is an important lysophospholipid which can improve blood glucose levels in diabetic mice and attenuate inflammation by activating AMPK signal pathway in macrophages. Synthetic alkylphospholipids (ALPs), such as miltefosine, is used as an alternate of LPC for the clinical application. Here, we investigated whether miltefosine could have an impact on hepatic steatosis and related metabolic disorders. Experimental Approach Mice were fed with high fat diet (HFD) for 16 weeks to generate an obese model. Next, the obese mice were randomly divided into three groups: saline-treated and miltefosine-treated (2.5 or 5 mg/kg/d) groups. Miltefosine was intraperitoneally administrated into mice for additional 4 weeks plus HFD treatment. Key Results It was shown that miltefosine treatment could substantially improve glucose metabolism, prevented hepatic lipid accumulation, and inhibited liver inflammation in HFD-fed mice by activating AMPK signal pathway. In vitro, miltefosine stimulated AMPKα phosphorylation both in time and dose dependent manner and decreased lipid accumulation in liver cells. When a specific AMPK inhibitor compound C was used to treat mice, the antagonistic effects of miltefosine on HFD-induced mouse hyperlipidaemia and liver steatosis were abolished. Treatment with miltefosine also dramatically inhibited the HFD-induced liver inflammation in mice. Conclusions and Implications Here we demonstrated that miltefosine might be a new activator of AMPK signal pathway in vivo and in vitro and be useful for treatment of hepatic steatosis and related metabolic disorders. PMID:27681040

  20. GCN2 is required to increase fibroblast growth factor 21 and maintain hepatic triglyceride homeostasis during asparaginase treatment.

    PubMed

    Wilson, Gabriel J; Lennox, Brittany A; She, Pengxiang; Mirek, Emily T; Al Baghdadi, Rana J T; Fusakio, Michael E; Dixon, Joseph L; Henderson, Gregory C; Wek, Ronald C; Anthony, Tracy G

    2015-02-15

    The antileukemic agent asparaginase triggers the amino acid response (AAR) in the liver by activating the eukaryotic initiation factor 2 (eIF2) kinase general control nonderepressible 2 (GCN2). To explore the mechanism by which AAR induction is necessary to mitigate hepatic lipid accumulation and prevent liver dysfunction during continued asparaginase treatment, wild-type and Gcn2 null mice were injected once daily with asparaginase or phosphate buffered saline for up to 14 days. Asparaginase induced mRNA expression of multiple AAR genes and greatly increased circulating concentrations of the metabolic hormone fibroblast growth factor 21 (FGF21) independent of food intake. Loss of Gcn2 precluded mRNA expression and circulating levels of FGF21 and blocked mRNA expression of multiple genes regulating lipid synthesis and metabolism including Fas, Ppara, Pparg, Acadm, and Scd1 in both liver and white adipose tissue. Furthermore, rates of triglyceride export and protein expression of apolipoproteinB-100 were significantly reduced in the livers of Gcn2 null mice treated with asparaginase, providing a mechanistic basis for the increase in hepatic lipid content. Loss of AAR-regulated antioxidant defenses in Gcn2 null livers was signified by reduced Gpx1 gene expression alongside increased lipid peroxidation. Substantial reductions in antithrombin III hepatic expression and activity in the blood of asparaginase-treated Gcn2 null mice indicated liver dysfunction. These results suggest that the ability of the liver to adapt to prolonged asparaginase treatment is influenced by GCN2-directed regulation of FGF21 and oxidative defenses, which, when lost, corresponds with maladaptive effects on lipid metabolism and hemostasis.

  1. Hepatitis B antigen in hepatocytes of chronic active liver disease.

    PubMed

    Kawanishi, H

    1979-04-01

    To study the morphologic interrelation of hepatocytes with the replication of hepatitis B vius (HBV) and immunocompetent cells in chronic active liver disease(CALD), organ cultures were prepared from liver biopsy specimens. Replication of hepatitis B core antigen (HBcAg) appears to occur in the nucleus of the hepatocyte in close association with intranuclear electron-dense strands and sometimes intranucleolar matrixes (likely HBcAg genomes), and cytoplasmic maturation of the HBcAg takes place in the preautolytic condition of host hepatocytes. Immunocompetent cells became progressively autolyzed in the early period of cultures. No difference in progression of hepatocyte injury in tissues from normal subjects and from hepatitis B surface antigen (HBsAg)-positive and HBsAg-negative patients with CALD may suggest that intracellular synthesis of HBV alone is not cytopathic to host hepatocytes. This model is promising for the study of HBV replication and development, and also for testing the efficacy of new antiviral agents against the virus.

  2. Increased circulation of hepatitis A virus genotype IIIA over the last decade in St Petersburg, Russia.

    PubMed

    Mukomolov, Sergey; Kontio, Mia; Zheleznova, Nina; Jokinen, Sari; Sinayskaya, Eugenia; Stalevskaya, Anna; Davidkin, Irja

    2012-10-01

    The current study, covering the period 2004-2009, is a part of long-term monitoring for hepatitis A virus (HAV) strains circulating in St Petersburg, Russia. The HAV RNA was isolated directly from the sera of hepatitis A patients and RT-PCR was carried out using primer pairs for VP1/2A and VP1 genomic regions. PCR products were sequenced and 324 nucleotides from VP1/2A and 332 from the VP1 region were used for phylogenetic analysis. The results show that the IA subtype was the most common circulating subtype during the follow-up period, as found in the previous study: almost 90% of the isolated HAV strains belonged to the IA subtype. The large hepatitis A food-borne outbreak in St Petersburg in 2005 was caused by HAV IA. However, the proportion of HAV isolates belonging to subtype IIIA significantly increased in the period 2001-2009 (7.9%) compared to the period 1997-2000 (none found). The subtype IIIA was first found in St Petersburg in 2001 among a group of intravenous drug users. The increase in its circulation during the decade suggests that this previously unusual genotype has been permanently introduced into the general population of St Petersburg. These results indicate the usefulness of molecular epidemiological methods for studying changes in the circulation of HAV strains.

  3. Succinate causes α-SMA production through GPR91 activation in hepatic stellate cells.

    PubMed

    Li, Ying Hui; Woo, Sung Hoon; Choi, Dae Hee; Cho, Eun-Hee

    2015-08-07

    Succinate acts as an extracellular signaling molecule as well as an intermediate in the citric acid cycle. It binds to and activates its specific G protein-coupled receptor 91 (GPR91). GPR91 is present in hepatic stellate cells (HSCs), but its role in hepatic fibrogenesis remains unclear. Cultured HSCs treated with succinate showed increased protein expression of GPR91 and α-smooth muscle actin (α-SMA), markers of fibrogenic response. Succinate also increased mRNA expression of α-SMA, transforming growth factor β (TGF-β), and collagen type I. Transfection of siRNA against GPR91 abrogated succinate-induced increases in α-SMA expression. Malonate, an inhibitor of succinate dehydrogenase (SDH), increased succinate levels in cultured HSCs and increased GPR91 and α-SMA expression. Feeding mice a methionine- and choline-deficient (MCD) diet is a widely used technique to create an animal model of nonalcoholic steatohepatitis (NASH). HSCs cultured in MCD media showed significantly decreased SDH activity and increased succinate concentration and GPR91 and α-SMA expression. Similarly, palmitate treatment significantly decreased SDH activity and increased GPR91 and α-SMA expression. Finally, C57BL6/J mice fed the MCD diet had elevated succinate levels in their plasma. The MCD diet also decreased SDH activity, increased succinate concentration, and increased GPR91 and α-SMA expression in isolated HSCs. Collectively, our results show that succinate plays an important role in HSC activation through GPR91 induction, and suggest that succinate and GPR91 may represent new therapeutic targets for modulating hepatic fibrosis.

  4. Oxidative stress and hepatic stellate cell activation are key events in arsenic induced liver fibrosis in mice

    SciTech Connect

    Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna; Chowdhury, Abhijit; Boyer, James L.; Santra, Amal

    2011-02-15

    Arsenic is an environmental toxicant and carcinogen. Exposure to arsenic is associated with development of liver fibrosis and portal hypertension through ill defined mechanisms. We evaluated hepatic fibrogenesis after long term arsenic exposure in a murine model. BALB/c mice were exposed to arsenic by daily gavages of 6 {mu}g/gm body weight for 1 year and were evaluated for markers of hepatic oxidative stress and fibrosis, as well as pro-inflammatory, pro-apoptotic and pro-fibrogenic factors at 9 and 12 months. Hepatic NADPH oxidase activity progressively increased in arsenic exposure with concomitant development of hepatic oxidative stress. Hepatic steatosis with occasional collection of mononuclear inflammatory cells and mild portal fibrosis were the predominant liver lesion observed after 9 months of arsenic exposure, while at 12 months, the changes included mild hepatic steatosis, inflammation, necrosis and significant fibrosis in periportal areas. The pathologic changes in the liver were associated with markers of hepatic stellate cells (HSCs) activation, matrix reorganization and fibrosis including {alpha}-smooth muscle actin, transforming growth factor-{beta}1, PDGF-R{beta}, pro-inflammatory cytokines and enhanced expression of tissue inhibitor of metalloproteinase-1 and pro({alpha}) collagen type I. Moreover, pro-apoptotic protein Bax was dominantly expressed and Bcl-2 was down-regulated along with increased number of TUNEL positive hepatocytes in liver of arsenic exposed mice. Furthermore, HSCs activation due to increased hepatic oxidative stress observed after in vivo arsenic exposure was recapitulated in co-culture model of isolated HSCs and hepatocytes exposed to arsenic. These findings have implications not only for the understanding of the pathology of arsenic related liver fibrosis but also for the design of preventive strategies in chronic arsenicosis.

  5. Lymphocyte activation and hepatic cellular infiltration in immunocompetent mice infected by dengue virus.

    PubMed

    Chen, Hsuen-Chin; Lai, Show-Yun; Sung, Jui-Min; Lee, Shu-Hwae; Lin, Yu-Chin; Wang, Wei-Kung; Chen, Yee-Chun; Kao, Chuan-Liang; King, Chwan-Chuen; Wu-Hsieh, Betty A

    2004-07-01

    Activation and expansion of dengue virus-specific T cells and abnormal liver functions in dengue patients have been documented. However, it remains to be determined whether T cells are involved in the pathogenic mechanism of dengue virus infection. In this study, immunocompetent C57BL/6 mice were employed to study dengue virus-induced T cell activation. Mice were inoculated with 10(8) PFU dengue virus serotype 2 strain 16681 by the intravenous route. Dengue viral core RNA was detected by RT-PCR in mouse serum, liver, spleen, and brain at different time points after infection. Splenic T cells were activated as evidenced by their expression of CD69 and O-glycosylated CD43 at as early as day 3 after infection. Splenic T cell expression of O-glycosylated CD43 and IFN-gamma production coordinately peaked at day 5. Coincided with the peak of splenic T cell activation was hepatic lymphocyte infiltration and elevation of liver enzymes. Flow cytometric analysis revealed the infiltrating CD8(+) T cell to CD4(+) T cell ratio was 5/3. After a second inoculation of dengue virus, hepatic T cell infiltration and liver enzyme levels increased sharply. The infiltrating hepatic CD8(+) T cell to CD4(+) T cell ratio increased to 5.8/1. A strong correlation was found between T cell activation and hepatic cellular infiltration in immunocompetent mice infected with dengue virus. The kinetics of liver enzyme elevation also correlated with that of T cell activation. These data suggest a relationship between T cell infiltration and elevation of liver enzymes.

  6. [Activity of the marker liver enzymes under the conditions of toxic hepatitis and alimentary deprivation of protein].

    PubMed

    Voloshchuk, O N; Kopyl'chuk, G P; Buchkovskaia, I M

    2014-01-01

    The activity of the sorbitoldehydrogenase (SDH), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in the blood serum of rats with acetaminophen-induced hepatitis under the conditions of alimentary deprivation of protein was studied. The animals were divided into 3 groups: 1--rats with acute acetaminophen-induced hepatitis, maintained on the full ration; 2--rats with acute acetaminophen-induced hepatitis, maintained under the conditions of alimentary deprivation of protein; 3--control. The activity of the sorbitol dehydrogenase in blood serum was determined by the kinetic method, activity of the alanine aminotransferase and alkaline phosphatase - photometrically. It is shown, that in animals with the model hepatitis the activity of sorbitol dehydrogenase in blood serum increases 20-fold, wherein statistical significance between animals with hepatitis maintained under the conditions of full ration and those of low-protein diet is not established. In the group of animals with acetaminophen-induced hepatitis the preservation on the control level of the alkaline phosphatase activity on the base of the increase of alanine aminotransferase by 2.2 times and ratio ALT/ALP>5 testifies about hepatocellular liver injury. In the group of animals with drug-induced hepatitis and alimentary deprivation of protein, the increase of the alkaline phosphatase and alanine aminotransferase activity is observed, herewith the ratio ALT/ALP ranges from 2 to 5 and testifies about mixed liver injury. The conclusion was made, that alimentary deprivation of protein is the critical factor for the development of the disturbances of functional and structural liver integrity, and the therapeutic approaches to the correction of the drug-induced liver injury should be different depending on the value of protein ration in the anamnesis, taking into account the different types of liver injury.

  7. Ligand activation of peroxisome proliferator-activated receptor-β/δ suppresses liver tumorigenesis in hepatitis B transgenic mice.

    PubMed

    Balandaram, Gayathri; Kramer, Lance R; Kang, Boo-Hyon; Murray, Iain A; Perdew, Gary H; Gonzalez, Frank J; Peters, Jeffrey M

    2016-07-01

    Peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) inhibits steatosis and inflammation, known risk factors for liver cancer. In this study, the effect of ligand activation of PPARβ/δ in modulating liver tumorigenesis in transgenic hepatitis B virus (HBV) mice was examined. Activation of PPARβ/δ in HBV mice reduced steatosis, the average number of liver foci, and tumor multiplicity. Reduced expression of hepatic CYCLIN D1 and c-MYC, tumor necrosis factor alpha (Tnfa) mRNA, serum levels of alanine aminotransaminase, and an increase in apoptotic signaling was also observed following ligand activation of PPARβ/δ in HBV mice compared to controls. Inhibition of Tnfa mRNA expression was not observed in wild-type hepatocytes. Ligand activation of PPARβ/δ inhibited lipopolysaccharide (LPS)-induced mRNA expression of Tnfa in wild-type, but not in Pparβ/δ-null Kupffer cells. Interestingly, LPS-induced expression of Tnfa mRNA was also inhibited in Kupffer cells from a transgenic mouse line that expressed a DNA binding mutant form of PPARβ/δ compared to controls. Combined, these results suggest that ligand activation of PPARβ/δ attenuates hepatic tumorigenesis in HBV transgenic mice by inhibiting steatosis and cell proliferation, enhancing hepatocyte apoptosis, and modulating anti-inflammatory activity in Kupffer cells.

  8. Increased T-cell sinusoidal lymphocytosis in liver biopsies in patients with chronic hepatitis C and mixed cryoglobulinemia.

    PubMed

    Carmack, Susanne; Taddei, Tamar; Robert, Marie E; Mistry, Pramod; Jain, Dhanpat

    2008-03-01

    Mixed cryoglobulinemia (MC) has a strong association with hepatitis C virus (HCV) infection and is associated with a higher degree of fibrosis and poor response to therapy. Currently, there are no known histological findings on liver biopsy that correlate with the presence of MC in HCV-infected patients, although we have occasionally noted prominent sinusoidal lymphocytosis in MC patients. The goal of this study is to determine whether sinusoidal lymphocytosis is a histological marker of MC in liver biopsies from patients with chronic hepatitis C. The liver clinic database at our institution was searched for chronic hepatitis C patients with MC who underwent liver biopsy during 1999-2005. Ten such cases were identified and were included in the study. Ten chronic hepatitis C MC-negative cases were matched for age and stage of fibrosis to serve as controls. Histological features (sinusoidal lymphocytes, inflammatory activity, acidophil bodies, and fibrosis stage) were evaluated in each biopsy. Clinical and laboratory data (serum protein electrophoresis, liver enzymes, hepatitis C viral load, treatment status, comorbidities, etc.) were also recorded. Formalin-fixed, paraffin-embedded sections were submitted for immunohistochemical analysis using antibodies against CD3, CD20, CD4, CD8, and CD68. Sinusoidal lymphocytes were counted in 5 hpf (40x) on hematoxylin and eosin (H&E) stain, and on CD3 and CD20 immunostains. The number of CD68+ Kupffer cells was also counted in a similar fashion. In the MC-positive versus MC-negative cases, mean fibrosis stage (2.4 vs. 2.4), inflammatory grade (1.7 vs. 2.1), lymphocyte count (359 vs. 128/5 hpf), and Kupffer cell count (239 vs. 220/5 HPF) were assessed. There was a significant increase in sinusoidal T-cell lymphocytes (P < 0.05) in MC-positive cases as compared to MC-negative cases. Nearly all sinusoidal lymphocytes were CD8-positive cells in both groups. Other histological parameters did not differ in the two groups. MC

  9. "Know More Hepatitis:" CDC's National Education Campaign to Increase Hepatitis C Testing Among People Born Between 1945 and 1965.

    PubMed

    Jorgensen, Cynthia; Carnes, C Amanda; Downs, Alycia

    2016-01-01

    In 2012, CDC issued recommendations calling for those born between 1945 and 1965, or baby boomers, to get tested for the hepatitis C virus. To help implement this recommendation, CDC developed "Know More Hepatitis," a multimedia national education campaign. Guided by behavioral science theories and formative research, the campaign used multiple strategies to reach baby boomers and health-care providers with messages encouraging baby boomers to get tested for hepatitis C. With a limited campaign budget, the "Know More Hepatitis" campaign relied mostly on donated time and space from broadcast and print outlets. Donated placements totaled approximately $14.7 million, which reflected a more than 12-to-1 return on the campaign investment. This effort was supplemented with a small, paid digital advertising campaign. Combining audience impressions from both paid and donated campaign efforts resulted in more than 1.2 billion audience impressions.

  10. Pet veterinarians have no increased risk of hepatitis E compared to the general population.

    PubMed

    Mesquita, J R; Valente-Gomes, G; Conceição-Neto, N; Nascimento, M S J

    2014-06-01

    The discovery of autochthonous hepatitis E in industrialized countries associated to genotype 3 has changed substantially the understanding about hepatitis E virus (HEV) circulation. In these countries transmission has been associated to the consumption and direct contact to swine, a well-known reservoir for HEV. More animal reservoirs for HEV might exist since antibodies to HEV have been detected in other animal species, such as dogs and cats. Given the intimate contact between these pets and humans, the potential zoonotic HEV transmission from dogs and cats deserves to be explored. To address this issue, 493 sera from pet veterinarians (373) and matched general population (120) were tested for the presence of anti-HEV IgG using a commercial ELISA. Antibodies to HEV were found in 9.9% veterinarians and 13.3% general population. No statistically significant difference was found between these two groups showing that pet veterinarians have no increased risk to hepatitis E compared to the general population.

  11. Dietary quercetin supplementation increases serum antioxidant capacity and alters hepatic gene expression profile in rats.

    PubMed

    Zhao, Liting; Wu, Jianquan; Yang, Jijun; Wei, Jingyu; Gao, Weina; Guo, Changjiang

    2011-06-01

    The aim of this study was to determine the effect of quercetin on hepatic gene expression profile in rats. Twenty male Wistar rats were divided into the control group and the quercetin-treated group, in which a diet containing 0.5% quercetin was provided. After two weeks of feeding, serum and liver samples were collected. Biomarkers of oxidative stress, including serum ferric reducing antioxidant power (FRAP) values and levels of ascorbic acid, vitamin E (VE), glutathione (GSH) and malondialdehyde (MDA) were measured. The hepatic gene expression profile was examined using a microarray technique. The results showed that serum FRAP value, levels of ascorbic acid and VE were increased significantly, whereas serum levels of GSH and MDA were not changed significantly after quercetin supplementation. The microarray analysis revealed that some hepatic genes involved in phase 2 reaction, metabolism of cholesterol and homocysteine, and energy production were expressed differentially in response to quercetin administration. These findings provide a molecular basis for the elucidation of the actions played by quercetin in vivo.

  12. Viral hepatitis A, active component, U.S. Armed Forces, 2000-2010.

    PubMed

    2011-08-01

    From 2000 to 2010, there were 214 incident diagnoses of acute hepatitis A among active component members of the U.S. Armed Forces; the crude overall incidence rate during the period was 1.37 per 100,000 person-years. Rates of incident diagnoses of acute hepatitis A were relatively low throughout the period and much lower than during the pre-vaccine era (1990-1996). There were disproportionate numbers of diagnoses of acute hepatitis A among service members born in countries endemic for the infection. The low rates of acute hepatitis A among U.S. military members overall reflect the widespread use of hepatitis A virus vaccine.

  13. Increasing LAG-3 expression suppresses T-cell function in chronic hepatitis B

    PubMed Central

    Ye, Bo; Li, Xuefen; Dong, Yuejiao; Wang, Yiyin; Tian, Li; Lin, Sha; Liu, Xia; Kong, Haishen; Chen, Yu

    2017-01-01

    Abstract Weak or absent virus-specific CD8+ T-cell responses to hepatitis B virus (HBV) infection are thought to be responsible for persistent HBV infection. Previous studies have indicated that multiple inhibitory receptors, including lymphocyte activation gene-3 (LAG-3), can suppress the CD8+ T-cell response in chronic viral infection. This study aimed to detect LAG-3 expression and to investigate the manner in which the immune response is regulated to balance the strength of the response with the extent of liver injury in chronic HBV infection. The results showed that LAG-3 expression levels were significantly higher in CD8+ T cells from chronic hepatitis B patients in the immune-active phase compared with chronic asymptomatic HBV carriers and healthy controls. CD8+ T-cell function was suppressed in cells with high LAG-3 expression, and these cells exhibited reduced interferon-γ (IFN-γ) secretion. Furthermore, IFN-γ secretion was restored in CD8+ T cells that were treated with a specific antibody to LAG-3. Taken together, liver injury was prominent in the immune-active phase, but suppressing T-cell function could mitigate this damage. Importantly, the inhibitory function of LAG-3 can be blocked using a LAG-3-specific antibody, and this can restore the activity of non-functional T cells. PMID:28072682

  14. Metformin regulates hepatic lipid metabolism through activating AMP-activated protein kinase and inducing ATGL in laying hens.

    PubMed

    Chen, Wei-Lu; Wei, Hen-Wei; Chiu, Wen-Zan; Kang, Ching-Hui; Lin, Ting-Han; Hung, Chien-Ching; Chen, Ming-Chun; Shieh, Ming-Song; Lee, Chin-Cheng; Lee, Horng-Mo

    2011-12-05

    Although many clinical trials have showed that metformin improves non-alcoholic fatty liver disease, which is a common liver disease associated with hepatic enzyme abnormalities, an animal model is required to investigate the effects of altered gene expression and post-translational processing (proteins) in mediating the observed responses. Laying hens appear to develop fatty livers, as in the case in human beings, when ingesting energy in excess of maintenance, and they can be used as an animal model for observing hepatic steatosis. The aim of this study was to investigate whether metformin could improve the non-alcoholic fatty liver of laying hens and to examine the possible mechanisms of lipid-lowering effects. Forty-eight Leghorn laying hens of Hy-Line variety W-36 - 44 weeks with 64.8% hen-day egg production - were randomly assigned into 4 treatments, each receiving 0, 10, 30, or 100mg of metformin with saline per kg body weight by daily wing vein injection. Results showed that, compared with the control, significant decreases existed in the laying rates; plasma triglyceride, cholesterol, and insulin levels; body weights; abdominal fat weights; hepatic lipid contents; and hepatic fatty acid synthase expression of layers receiving 30 or 100mg per kg body weight, whereas significant increases in their hepatic 5'adenosine monophosphate-activated protein kinase, acyl-CoA carboxylase phosphorylation, adipose triglyceride lipase, and carnitine palmitoyl transferase-1 expression were observed. These data suggest that metformin could reduce lipid deposits in the liver and that the laying hen is a valuable animal model for studying hepatic steatosis.

  15. Absence of melatonin induces night-time hepatic insulin resistance and increased gluconeogenesis due to stimulation of nocturnal unfolded protein response.

    PubMed

    Nogueira, Tatiane C; Lellis-Santos, Camilo; Jesus, Daniel S; Taneda, Marco; Rodrigues, Sandra C; Amaral, Fernanda G; Lopes, Ana Maria S; Cipolla-Neto, José; Bordin, Silvana; Anhê, Gabriel F

    2011-04-01

    It is known that the circadian rhythm in hepatic phosphoenolpyruvate carboxykinase expression (a limiting catalytic step of gluconeogenesis) and hepatic glucose production is maintained by both daily oscillation in autonomic inputs to the liver and night feeding behavior. However, increased glycemia and reduced melatonin (Mel) levels have been recently shown to coexist in diabetic patients at the end of the night period. In parallel, pinealectomy (PINX) is known to cause glucose intolerance with increased basal glycemia exclusively at the end of the night. The mechanisms that underlie this metabolic feature are not completely understood. Here, we demonstrate that PINX rats show night-time hepatic insulin resistance characterized by reduced insulin-stimulated RAC-α serine/threonine-protein kinase phosphorylation and increased phosphoenolpyruvate carboxykinase expression. In addition, PINX rats display increased conversion of pyruvate into glucose at the end of the night. The regulatory mechanism suggests the participation of unfolded protein response (UPR), because PINX induces night-time increase in activating transcription factor 6 expression and prompts a circadian fashion of immunoglobulin heavy chain-binding protein, activating transcription factor 4, and CCAAT/enhancer-binding protein-homologous protein expression with Zenith values at the dark period. PINX also caused a night-time increase in Tribble 3 and regulatory-associated protein of mammalian target of rapamycin; both were reduced in liver of PINX rats treated with Mel. Treatment of PINX rats with 4-phenyl butyric acid, an inhibitor of UPR, restored night-time hepatic insulin sensitivity and abrogated gluconeogenesis in PINX rats. Altogether, the present data show that a circadian oscillation of UPR occurs in the liver due to the absence of Mel. The nocturnal UPR activation is related with night-time hepatic insulin resistance and increased gluconeogenesis in PINX rats.

  16. Acetaminophen increases the risk of arsenic-mediated development of hepatic damage in rats by enhancing redox-signaling mechanism.

    PubMed

    Majhi, Chhaya Rani; Khan, Saleem; Leo, Marie Dennis Marcus; Prawez, Shahid; Kumar, Amit; Sankar, Palanisamy; Telang, Avinash Gopal; Sarkar, Souvendra Nath

    2014-02-01

    We evaluated whether the commonly used analgesic-antipyretic drug acetaminophen can modify the arsenic-induced hepatic oxidative stress and also whether withdrawal of acetaminophen administration during the course of long-term arsenic exposure can increase susceptibility of liver to arsenic toxicity. Acetaminophen was co-administered orally to rats for 3 days following 28 days of arsenic pre-exposure (Phase-I) and thereafter, acetaminophen was withdrawn, but arsenic exposure was continued for another 28 days (Phase-II). Arsenic increased lipid peroxidation and reactive oxygen species (ROS) generation, depleted glutathione (GSH), and decreased superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glutathione reductase (GR) activities. Acetaminophen caused exacerbation of arsenic-mediated lipid peroxidation and ROS generation and further enhancement of serum alanine aminotransferase and aspartate aminotransferase activities. In Phase-I, acetaminophen caused further GSH depletion and reduction in SOD, catalase, GPx and GR activities, but in Phase-II, only GPx and GR activities were more affected. Arsenic did not alter basal and inducible nitric oxide synthase (iNOS)-mediated NO production, but decreased constitutive NOS (cNOS)-mediated NO release. Arsenic reduced expression of endothelial NOS (eNOS) and iNOS genes. Acetaminophen up-regulated eNOS and iNOS expression and NO production in Phase-I, but reversed these effects in Phase-II. Results reveal that acetaminophen increased the risk of arsenic-mediated hepatic oxidative damage. Withdrawal of acetaminophen administration also increased susceptibility of liver to hepatotoxicity. Both ROS and NO appeared to mediate lipid peroxidation in Phase-I, whereas only ROS appeared responsible for peroxidative damage in Phase-II.

  17. Rifampicin-Induced Hepatic Lipid Accumulation: Association with Up-Regulation of Peroxisome Proliferator-Activated Receptor γ in Mouse Liver

    PubMed Central

    Zhang, Da-Gang; Li, Lu; Chen, Xi; Xu, De-Xiang

    2016-01-01

    Previous study found that rifampicin caused intrahepatic cholestasis. This study investigated the effects of rifampicin on hepatic lipid metabolism. Mice were orally administered with rifampicin (200 mg/kg) daily for different periods. Results showed that serum TG level was progressively reduced after a short elevation. By contrast, hepatic TG content was markedly increased in rifampicin-treated mice. An obvious hepatic lipid accumulation, as determined by Oil Red O staining, was observed in mice treated with rifampicin for more than one week. Moreover, mRNA levels of Fas, Acc and Scd-1, several key genes for fatty acid synthesis, were elevated in rifampicin-treated mice. In addition, the class B scavenger receptor CD36 was progressively up-regulated by rifampicin. Interestingly, hepatic SREBP-1c and LXR-α, two important transcription factors that regulate genes for hepatic fatty acid synthesis, were not activated by rifampicin. Instead, hepatic PXR was rapidly activated in rifampicin-treated mice. Hepatic PPARγ, a downstream target of PXR, was transcriptionally up-regulated. Taken together, the increased hepatic lipid synthesis and uptake of fatty acids from circulation into liver jointly contribute to rifampicin-induced hepatic lipid accumulation. The increased uptake of fatty acids from circulation into liver might be partially attributed to rifampicin-induced up-regulation of PPARγ and its target genes. PMID:27806127

  18. Kaempferol regulates the lipid-profile in high-fat diet-fed rats through an increase in hepatic PPARα levels.

    PubMed

    Chang, Chia Ju; Tzeng, Thing-Fong; Liou, Shorong-Shii; Chang, Yuan-Shiun; Liu, I-Min

    2011-11-01

    The aim of this study was to investigate the antiobesity and antihyperlipidemic effects of the flavonoid kaempferol (3,5,7,4'-tetrahydroxyflavone). After being fed a high-fat diet (HFD) for two weeks, rats were dosed orally with kaempferol (75, 150, or 300 mg/kg) or fenofibrate (100 mg/kg) once daily for eight weeks. Fenofibrate is an antilipemic agent that exerts its therapeutic effects through activation of peroxisome proliferator-activated receptor α (PPAR α). Kaempferol (300 mg/kg/day) produced effects similar to fenofibrate in reducing body weight gain, visceral fat-pad weights, plasma lipid levels, as well as the coronary artery risk and atherogenic indices of HFD-fed rats. Kaempferol also caused dose-related reductions in hepatic triglyceride and cholesterol content and lowered hepatic lipid droplet accumulation and the size of epididymal adipocytes in HFD-fed rats. Kaempferol and fenofibrate reversed the HFD-induced downregulation of hepatic PPAR α. HFD-induced reductions in the hepatic levels of acyl-CoA oxidase (ACO), and cytochrome P450 isoform 4A1 (CYP4A1) proteins were reversed by kaempferol and fenofibrate. The elevated expression of hepatic sterol regulatory element binding proteins (SREBPs) in HFD-fed rats were lowered by kaempferol and fenofibrate. These results suggest that kaempferol reduced the accumulation of visceral fat and improved hyperlipidemia in HFD-fed obese rats by increasing lipid metabolism through the downregulation of SREBPs and promoting the hepatic expression of ACO and CYP4A1, secondary to a direct upregulation hepatic PPAR α expression.

  19. The effect of cold on serum thyroid hormones and hepatic 5 prime mono-deiodinase activity

    SciTech Connect

    Hesslink, R.L. Jr.; Quesada, M.; D'Alesandro, M.; Homer, L.D.; Reed, J.L.; Christopherson, R.; Young, B.A. Univ. of Alberta, Edmonton )

    1991-03-11

    Cold exposed swine have an increases serum concentration of triiodothyronine (T{sub 3}) and increased T{sub 3} production rate. It is thought that hepatic thyroxine (T{sub 4}) deiodination (5DI) contributes to circulating T{sub 3} concentrations. The authors investigated the effects of cold exposure (14 days) on energy intake, serum free T{sub 3} (FT{sub 3}) and free T{sub 4} (FT{sub 4}) levels; and 5DI in 5-month boars. Hepatic 5DI activity was determined by measuring the {sup 125}I generated from trace amounts of {sup 125}I T{sub 4}. FT{sub 3} and FT{sub 4} were assayed by RIA. Swine were housed in either 20C (control; n = 5) or 4C (cold; n = 7) chambers and given food ad libitum. Cold exposure increased energy intake by 42%. The increase (93%) in hepatic 5DI V{sub max} after cold exposure parallels the increase in whole animal T{sub 3} production and may account for FT{sub 3} values found after cold exposure.

  20. Altered hyperlipidemia, hepatic steatosis, and hepatic peroxisome proliferator-activated receptors in rats with intake of tart cherry.

    PubMed

    Seymour, E Mitchell; Singer, Andrew A M; Kirakosyan, Ara; Urcuyo-Llanes, Daniel E; Kaufman, Peter B; Bolling, Steven F

    2008-06-01

    Elevated plasma lipids, glucose, insulin, and fatty liver are among components of metabolic syndrome, a phenotypic pattern that typically precedes the development of Type 2 diabetes. Animal studies show that intake of anthocyanins reduces hyperlipidemia, obesity, and atherosclerosis and that anthocyanin-rich extracts may exert these effects in association with altered activity of tissue peroxisome proliferator-activated receptors (PPARs). However, studies are lacking to test this correlation using physiologically relevant, whole food sources of anthocyanins. Tart cherries are a rich source of anthocyanins, and whole cherry fruit intake may also affect hyperlipidemia and/or affect tissue PPARs. This hypothesis was tested in the Dahl Salt-Sensitive rat having insulin resistance and hyperlipidemia. For 90 days, Dahl rats were pair-fed AIN-76a-based diets supplemented with either 1% (wt:wt) freeze-dried whole tart cherry or with 0.85% additional carbohydrate to match macronutrient and calorie provision. After 90 days, the cherry-enriched diet was associated with reduced fasting blood glucose, hyperlipidemia, hyperinsulinemia, and reduced fatty liver. The cherry diet was also associated with significantly enhanced hepatic PPAR-alpha mRNA, enhanced hepatic PPAR-alpha target acyl-coenzyme A oxidase mRNA and activity, and increased plasma antioxidant capacity. In conclusion, physiologically relevant tart cherry consumption reduced several phenotypic risk factors that are associated with risk for metabolic syndrome and Type 2 diabetes. Tart cherries may represent a whole food research model of the health effects of anthocyanin-rich foods and may possess nutraceutical value against risk factors for metabolic syndrome and its clinical sequelae.

  1. EPAC activation inhibits acetaldehyde-induced activation and proliferation of hepatic stellate cell via Rap1.

    PubMed

    Yang, Yan; Yang, Feng; Wu, Xiaojuan; Lv, Xiongwen; Li, Jun

    2016-05-01

    Hepatic stellate cells (HSCs) activation represents an essential event during alcoholic liver fibrosis (ALF). Previous studies have demonstrated that the rat HSCs could be significantly activated after exposure to 200 μmol/L acetaldehyde for 48 h, and the cAMP/PKA signaling pathways were also dramatically upregulated in activated HSCs isolated from alcoholic fibrotic rat liver. Exchange protein activated by cAMP (EPAC) is a family of guanine nucleotide exchange factors (GEFs) for the small Ras-like GTPases Rap, and is being considered as a vital mediator of cAMP signaling in parallel with the principal cAMP target protein kinase A (PKA). Our data showed that both cAMP/PKA and cAMP/EPAC signaling pathways were involved in acetaldehyde-induced HSCs. Acetaldehyde could reduce the expression of EPAC1 while enhancing the expression of EPAC2. The cAMP analog Me-cAMP, which stimulates the EPAC/Rap1 pathway, could significantly decrease the proliferation and collagen synthesis of acetaldehyde-induced HSCs. Furthermore, depletion of EPAC2, but not EPAC1, prevented the activation of HSC measured as the production of α-SMA and collagen type I and III, indicating that EPAC1 appears to have protective effects on acetaldehyde-induced HSCs. Curiously, activation of PKA or EPAC perhaps has opposite effects on the synthesis of collagen and α-SMA: EPAC activation by Me-cAMP increased the levels of GTP-bound (activated) Rap1 while PKA activation by Phe-cAMP had no significant effects on such binding. These results suggested that EPAC activation could inhibit the activation and proliferation of acetaldehyde-induced HSCs via Rap1.

  2. Hepatitis C virus coinfection independently increases the risk of cardiovascular disease in HIV-positive patients.

    PubMed

    Fernández-Montero, J V; Barreiro, P; de Mendoza, C; Labarga, P; Soriano, V

    2016-01-01

    Patients infected with HIV are at increased risk for cardiovascular disease despite successful antiretroviral therapy. Likewise, chronic hepatitis C virus (HCV) infection is associated with extrahepatic complications, including cardiovascular disease. However the risk of cardiovascular disease has not been formally examined in HIV/HCV-coinfected patients. A retrospective study was carried out to assess the influence of HCV coinfection on the risk of cardiovascular events in a large cohort of HIV-infected patients recruited since year 2004. A composite event of cardiovascular disease was used as an endpoint, including myocardial infarction, angina pectoris, stroke or death due to any of them. A total of 1136 patients (567 HIV-monoinfected, 70 HCV-monoinfected and 499 HIV/HCV-coinfected) were analysed. Mean age was 42.7 years, 79% were males, and 46% were former injection drug users. Over a mean follow-up of 79.4 ± 21 months, 3 patients died due to cardiovascular disease, whereas 29 suffered a first episode of coronary ischaemia or stroke. HIV/HCV-coinfected patients had a greater incidence of cardiovascular disease events and/or death than HIV-monoinfected individuals (4% vs 1.2%, P = 0.004) and HCV-monoinfected persons (4% vs 1.4%, P = 0.5). After adjusting for demographics, virological parameters and classical cardiovascular disease risk factors (smoking, hypertension, diabetes, high LDL cholesterol), both HIV/HCV coinfection (HR 2.91; CI 95%: 1.19-7.12; P = 0.02) and hypertension (HR 3.65; CI 95%: 1.34-9.94; P = 0.01) were independently associated with cardiovascular disease events and/or death in HIV-infected patients. Chronic hepatitis C and hypertension are independently associated with increased cardiovascular disease risk in HIV-infected patients. Therefore, treatment of chronic hepatitis C should be prioritized in HIV/HCV-coinfected patients regardless of any liver fibrosis staging.

  3. Fetal and neonatal exposure to nicotine leads to augmented hepatic and circulating triglycerides in adult male offspring due to increased expression of fatty acid synthase.

    PubMed

    Ma, Noelle; Nicholson, Catherine J; Wong, Michael; Holloway, Alison C; Hardy, Daniel B

    2014-02-15

    While nicotine replacement therapy is assumed to be a safer alternative to smoking during pregnancy, the long-term consequences for the offspring remain elusive. Animal studies now suggest that maternal nicotine exposure during perinatal life leads to a wide range of adverse outcomes for the offspring including increased adiposity. The focus of this study was to investigate if nicotine exposure during pregnancy and lactation leads to alterations in hepatic triglyceride synthesis. Female Wistar rats were randomly assigned to receive daily subcutaneous injections of saline (vehicle) or nicotine bitartrate (1mg/kg/day) for two weeks prior to mating until weaning. At postnatal day 180 (PND 180), nicotine exposed offspring exhibited significantly elevated levels of circulating and hepatic triglycerides in the male offspring. This was concomitant with increased expression of fatty acid synthase (FAS), the critical hepatic enzyme in de novo triglyceride synthesis. Given that FAS is regulated by the nuclear receptor Liver X receptor (LXRα), we measured LXRα expression in both control and nicotine-exposed offspring. Nicotine exposure during pregnancy and lactation led to an increase in hepatic LXRα protein expression and enriched binding to the putative LXRE element on the FAS promoter in PND 180 male offspring. This was also associated with significantly enhanced acetylation of histone H3 [K9,14] surrounding the FAS promoter, a hallmark of chromatin activation. Collectively, these findings suggest that nicotine exposure during pregnancy and lactation leads to an increase in circulating and hepatic triglycerides long-term via changes in the transcriptional and epigenetic regulation of the hepatic lipogenic pathway.

  4. Icariin regulates systemic iron metabolism by increasing hepatic hepcidin expression through Stat3 and Smad1/5/8 signaling.

    PubMed

    Zhang, Miao; Liu, Jing; Guo, Wenli; Liu, Xin; Liu, Sijin; Yin, Huijun

    2016-05-01

    Systemic iron homeostasis is strictly controlled under normal conditions to ensure a balance between the absorption, utilization, storage and recycling of iron. The hepcidin-ferroportin (FPN) axis is of critical importance in the maintenance of iron homeostasis. Hepcidin deficiency gives rise to enhanced dietary iron absorption, as well as to increased iron release from macrophages, and this in turn results in iron accumulation in the plasma and organs, and is associated with a range of tissue pathologies. Low hepcidin levels have been demonstrated in most forms of hereditary hemochromatosis (HH), as well as in β-thalassemia. Therapies that increase hepcidin concentrations may potentially play a role in the treatment of these iron overload-related diseases. To date, natural compounds have not been extensively investigated for this purpose, to the best of our knowledge. Thus, in the present study, we screened natural compounds that have the potential to regulate hepcidin expression. By performing hepcidin promoter-luciferase assay, RT-qPCR and animal experiments, we demonstrated that icariin and berberine were potent stimulators of hepcidin transcription. Mechanistic experiments indicated that icariin and berberine increased hepcidin expression by activating the signal transducer and activator of transcription 3 (Stat3) and Smad1/5/8 signaling pathways. The induction of hepcidin was confirmed in mice following icariin administration, coupled with associated changes in serum and tissue iron concentrations. In support of these findings, the icariin analogues, epimedin A, B and C, also increased hepatic hepcidin expression. However, these changes were not observed in hepcidin-deficient [Hamp1-/- or Hamp1‑knockout (KO)] mice following icariin administration, thereby verifying hepatic hepcidin as the target of icariin. Although berberine exhibited a robust capacity to promote hepcidin expression in vitro, it failed to alter hepcidin expression in mice. Taken together

  5. PNPLA3 polymorphism increases risk for and severity of chronic hepatitis C liver disease

    PubMed Central

    Salameh, Habeeb; Masadeh, Maen; Al Hanayneh, Muhannad; Petros, Vincent; Maslonka, Matthew; Nanda, Arjun; Singal, Ashwani K

    2016-01-01

    AIM To examine the association of PNPLA3 polymorphisms in chronic hepatitis C patients and development of liver disease spectrum. METHODS Literature was searched systematically from PubMed/MEDLINE, EMBASE, and Cochrane search engines for full-length articles written in English that examined PNPLA3 polymorphism in chronic hepatitis C (CHC) patients. Studies evaluating the association of PNPLA3 polymorphism spectrum (fatty liver, steatohepatitis, cirrhosis, and hepatocellular carcinoma) of CHC were included. Pooled data are reported as OR with 95%CI. Our study endpoint was the risk of the entire liver disease spectrum including: Steatosis/fatty liver, cirrhosis, and hepatocellular carcinoma in CHC patients with PNPLA3 polymorphisms. RESULTS Of 380 studies identified, a total of 53 studies were included for full-text review. Nineteen on chronic hepatitis C were eligible for analysis. Pooled ORs for rs738409 GG compared to CC and CG among patients with fatty liver was 2.214 (95%CI: 1.719-2.853). ORs among advanced fibrosis/cirrhosis were 1.762 (95%CI: 1.258-2.468). Similar odds ratios among hepatocellular carcinoma patients were 2.002 (95%CI: 1.519-2.639). Pooled ORs for rs738409 GG and CG compared to CC among patients with fatty liver were 1.750 (95%CI: 1.542-1.986). Pooled ORs for advanced fibrosis/cirrhosis patients were 1.613 (95%CI: 1.211-2.147). All analyses were homogenous and without publication bias except one. The associations were maintained after adjusting for publication bias and heterogeneity. CONCLUSION PNPLA3 polymorphisms have strong association with increased risk and severity of the liver disease spectrum in CHC patients. PMID:28050240

  6. Exergames: Increasing Physical Activity through Effective Instruction

    ERIC Educational Resources Information Center

    Rudella, Jennifer L.; Butz, Jennifer V.

    2015-01-01

    Due to the growing obesity epidemic in the United States, educators must consider new ways to increase physical activity in an effort to address obesity. There are a variety of ways educators can increase physical activity in the classroom, and exergames--video games that require physical movement in order to play--are a modern-day approach to…

  7. Active viral B hepatitis in parenteral drug abusers with acquired immune deficiency syndrome (AIDS).

    PubMed

    Leevy, C B; Nurse, H; Kapila, R

    1989-01-01

    Eighty-percent of 47 parenteral drug abusers with hepatomegaly and acquired immunodeficiency syndrome had HBV DNA in serum, although only 27% were HBsAg or "e" antigen-positive by polyclonal radioimmunoassay. Liver biopsies from each of 37 HBV DNA seropositive patients showed HBV DNA and were HBcAg-positive. The absence of positive HBsAg and "e" antigen in HBV DNA-positive patients was attributable to the presence of immune complexes; after in vitro dissociation of these complexes there was an increase in HBsAg from 24% to 86%, and of "e" antigen from 19% to 62%. These data indicate that actively replicating hepatitis B virus is common in patients with AIDS, and that precautions should be taken to prevent its dissemination. Therapy in these patients should address both human immunodeficiency and hepatitis B virus infections.

  8. Randomised controlled trial of lymphoblastoid interferon for chronic active hepatitis B.

    PubMed Central

    Anderson, M G; Harrison, T J; Alexander, G; Zuckerman, A J; Murray-Lyon, I M

    1987-01-01

    Thirty male patients (27 homosexual) with biopsy proven chronic active hepatitis B were randomised to receive lymphoblastoid interferon (Wellferon) or no treatment. All patients were HBeAg positive and had continuing viral replication. Patients receiving treatment were given a single daily intramuscular injection of interferon for 28 days at a starting dose of 2.5 MU/m2 increasing to a maximum of 7.5 MU/m2/day. Transient side effects of malaise and influenza like symptoms occurred in all patients and resolved rapidly after treatment. Hepatitis B viral replication was suppressed during interferon treatment in all patients but the effect was limited to the period of therapy. After one year there was no appreciable difference in viral markers between the two groups of patients and this treatment schedule appears less effective than the thrice weekly, three month regimes recently reported from other centres. PMID:3297940

  9. Hepatic Microenvironment Affects Oval Cell Localization in Albumin-Urokinase-Type Plasminogen Activator Transgenic Mice

    PubMed Central

    Braun, Kristin M.; Thompson, Anne W.; Sandgren, Eric P.

    2003-01-01

    Mice carrying an albumin-urokinase type plasminogen activator transgene (AL-uPA) develop liver disease secondary to uPA expression in hepatocytes. Transgene-expressing parenchyma is replaced gradually by clones of cells that have deleted transgene DNA and therefore are not subject to uPA-mediated damage. Diseased liver displays several abnormalities, including hepatocyte vacuolation and changes in nonparenchymal tissue. The latter includes increases in laminin protein within parenchyma and the appearance of cytokeratin 19-positive bile ductule-like cells (oval cells) both in portal regions and extending into the hepatic parenchyma. In this study, we subjected AL-uPA mice to two-thirds partial hepatectomy to identify the response of these livers to additional growth stimulation. We observed several changes in hepatic morphology. First, the oval cells increased in number and often formed ductules in the parenchyma. Second, this cellular change was accompanied by a further increase in laminin associated with single or clusters of oval cells. Third, desmin-positive Ito cells increased in number and maintained close association with oval cells. Fourth, these changes were localized precisely to uPA-expressing areas of liver. Regenerating clones of uPA-deficient cells appeared to be unaffected both by stromal and cellular alterations. Thus, additional growth stimulation of diseased uPA-expressing liver induces an oval cell-like response, as observed in other models of severe hepatic injury, but the localization of this response seems to be highly regulated by the hepatic microenvironment. PMID:12507902

  10. Increased expression of regulatory Tr1 cells in recurrent hepatitis C after liver transplantation.

    PubMed

    Carpentier, A; Conti, F; Stenard, F; Aoudjehane, L; Miroux, C; Podevin, P; Morales, O; Chouzenoux, S; Scatton, O; Groux, H; Auriault, C; Calmus, Y; Pancre, V; Delhem, N

    2009-09-01

    Immune response failure during HCV infection has been associated with the activity of regulatory T cells. Hepatitis C-related cirrhosis is the main reason for liver transplantation. However, 80% of transplanted patients present an accelerated recurrence of the disease. This study assessed the involvement of regulatory T-cell subsets (CD4+CD25+ cells: 'Treg' and CD49b+CD18+ cells: 'T regulatory-1' cells), in the recurrence of HCV after liver transplantation, using transcriptomic analysis, ELISA assays on serum samples and immunohistochemistry on liver biopsies from liver recipients 1 and 5 years after transplantation. Three groups of patients were included: stable HCV-negative recipients and those with mild and severe hepatitis C recurrence. At 5 years, Treg markers were overexpressed in all HCV+ recipients. By contrast, Tr1 markers were only overexpressed in patients with severe recurrence. At 1 year, a trend toward the overexpression of Tr1 was noted in patients evolving toward severe recurrence. IL-10 production, a characteristic of the Tr1 subset, was enhanced in severe recurrence at both 1 and 5 years. These results suggest that Tr1 are enhanced during severe HCV recurrence after liver transplantation and could be predictive of HCV recurrence. High levels of IL-10 at 1 year could be predictive of severe recurrence, and high IL-10 producers might warrant more intensive management.

  11. Immunomodulation of activated hepatic stellate cells by mesenchymal stem cells

    SciTech Connect

    Parekkadan, Biju; Poll, Daan van; Megeed, Zaki; Kobayashi, Naoya; Tilles, Arno W.; Berthiaume, Francois; Yarmush, Martin L.

    2007-11-16

    Bone marrow-derived mesenchymal stem cells (MSCs) have been reported to prevent the development of liver fibrosis in a number of pre-clinical studies. Marked changes in liver histopathology and serological markers of liver function have been observed without a clear understanding of the therapeutic mechanism by which stem cells act. We sought to determine if MSCs could modulate the activity of resident liver cells, specifically hepatic stellate cells (SCs) by paracrine mechanisms using indirect cocultures. Indirect coculture of MSCs and activated SCs led to a significant decrease in collagen deposition and proliferation, while inducing apoptosis of activated SCs. The molecular mechanisms underlying the modulation of SC activity by MSCs were examined. IL-6 secretion from activated SCs induced IL-10 secretion from MSCs, suggesting a dynamic response of MSCs to the SCs in the microenvironment. Blockade of MSC-derived IL-10 and TNF-{alpha} abolished the inhibitory effects of MSCs on SC proliferation and collagen synthesis. In addition, release of HGF by MSCs was responsible for the marked induction of apoptosis in SCs as determined by antibody-neutralization studies. These findings demonstrate that MSCs can modulate the function of activated SCs via paracrine mechanisms provide a plausible explanation for the protective role of MSCs in liver inflammation and fibrosis, which may also be relevant to other models of tissue fibrosis.

  12. Impact of sustained virus elimination on natural anticoagulant activity in patients with chronic viral hepatitis C.

    PubMed

    Saray, Aida; Mesihović, Rusmir; Vukobrat-Bijedić, Zora; Gornjaković, Srđan; Vanis, Nenad; Mehmedović, Amila; Papović, Vedad; Glavaš, Sanjin

    2013-05-01

    Previous studies have reported reduced synthesis of various hemostatic factors in patients with chronic liver disease. Whether changes in plasma levels of these proteins reflect recovered liver synthetic function following virological eradication therapy has not been approved yet. The aim of the study was to determine the impact of sustained viral suppression achieved with pegylated interferon alpha and ribavirin on hemostatic parameters including natural anticoagulants in patients with chronic hepatitis C. The following coagulation screening tests were obtained in thirty patients with chronic viral hepatitis C before and after completion of antiviral treatment: activated partial thromboplastin time, prothrombin time, plasma fibrinogen and natural anticoagulant proteins antithrombin III, protein C (PC) and total protein S (PS) activity. Only patients who achieved durable virus suppression were included. The mean PC and PS levels were significantly lower in patients with chronic viral hepatitis C before antiviral therapy than in healthy controls (79.04 ± 16.19 % vs. 109.92 ± 21.33% and 54.04 ± 16.11% vs. 87.60 ± 8.15%, respectively; (p<0.001). Mean levels of PC exhibited a significant increase by 14.69 % after the completion of antiviral treatment (93.73 ± 14.18%, p<0.001) as well as PS levels, which significantly increased by 21.46% (75.50 ± 15.43, p<0.001) when compared with pre-treatment values. No remarkable fluctuations in other hemostatic parameters were noted. Protein C and protein S are sensitive markers of hepatocyte synthetic impairment and are valuable markers in monitoring the efficacy of antiviral treatment in chronic hepatitis C patients. Larger studies are needed to confirm our results.

  13. Protective benefits of AMP-activated protein kinase in hepatic ischemia-reperfusion injury

    PubMed Central

    Zhang, Min; Yang, Dan; Gong, Xianqiong; Ge, Pu; Dai, Jie; Lin, Ling; Zhang, Li

    2017-01-01

    Hepatic ischemia-reperfusion injury (HIRI) is a major cause of hepatic failure and death after liver trauma, haemorrhagic shock, resection surgery and liver transplantation. AMP-activated protein kinase (AMPK) is an energy sensitive kinase that plays crucial roles in the regulation of metabolic homeostasis. In HIRI, ischemia induces the decline of ATP and the increased ratio of AMP/ATP, which promotes the phosphorylation and activation of AMPK. Three AMPK kinases, liver kinase B1 (LKB1), Ca2+/calmodulin-depedent protein kinase kinase β (CaMKKβ) and TGF-β-activated kinase-1 (TAK1), are main upstream kinases for the phosphorylation of AMPK. In addition to the changed AMP/ATP ratio, the activated CaMKKβ by increased intracelluar Ca2+ and the overproduction of reactive oxygen species (ROS) are also involved in the activation of AMPK during HIRI. The activated AMPK might provide protective benefits in HIRI via prevention of energy decline, inhibition of inflammatory response, suppression of hepatocyte apoptosis and attenuation of oxidative stress. Thus, AMPK might become a novel target for the pharmacological intervention of HIRI. PMID:28386315

  14. Induction of hepatic cyclooxygenase-2 by hyperhomocysteinemia via nuclear factor-kappaB activation.

    PubMed

    Wu, Nan; Siow, Yaw L; O, Karmin

    2009-10-01

    Hyperhomocysteinemia, an elevation of blood homocysteine (Hcy), is a metabolic disorder associated with dysfunction of multiple organs. Apart from endothelial dysfunction, Hcy can cause hepatic lipid accumulation and liver injury. However, the mechanism responsible for Hcy-induced liver injury is poorly understood. The aim of this study was to investigate the regulation of cyclooxygenase-2 (COX-2), a proinflammatory factor, expression in the liver during the initial phase of hyperhomocysteinemia. Sprague-Dawley rats were fed a high-methionine diet for 1 or 4 wk. Serum and liver concentrations of Hcy were significantly elevated after 1 or 4 wk of dietary treatment. COX-2 mRNA and protein levels were significantly elevated in the liver of hyperhomocysteinemic rats. The induction of COX-2 expression was more prominent in 1-wk hyperhomocysteinemic rats than that in the 4-wk group. EMSA revealed an activation of NF-kappaB in the same liver tissue in which COX-2 was induced. Administration of a NF-kappaB inhibitor to hyperhomocysteinemic rats effectively abolished hepatic COX-2 expression, inhibited the formation of inflammatory foci, and improved liver function. Further investigation revealed that oxidative stress due to increased superoxide generation was responsible for increased phosphorylation and degradation of IkappaBalpha leading to NF-kappaB activation in the liver. Administration of 4-hydroxy-tetramethyl-piperidine-1-oxyl, an SOD mimetic, to hyperhomocysteinemic rats not only inhibited NF-kappaB activation but also prevented hepatic COX-2 induction and improved liver function. These results suggest that hyperhomocysteinemia-induced COX-2 expression is mediated via NF-kappaB activation. Increased oxidative stress and inflammatory response may contribute to liver injury associated with hyperhomocysteinemia.

  15. Liver stiffness is associated with monocyte activation in HIV-infected Ugandans without viral hepatitis.

    PubMed

    Redd, Andrew D; Wendel, Sarah K; Grabowski, Mary K; Ocama, Ponsiano; Kiggundu, Valerian; Bbosa, Francis; Boaz, Iga; Balagopal, Ashwin; Reynolds, Steven J; Gray, Ronald H; Serwadda, David; Kirk, Gregory D; Quinn, Thomas C; Stabinski, Lara

    2013-07-01

    A high prevalence of liver stiffness, as determined by elevated transient elastography liver stiffness measurement, was previously found in a cohort of HIV-infected Ugandans in the absence of chronic viral hepatitis. Given the role of immune activation and microbial translocation in models of liver disease, a shared immune mechanism was hypothesized in the same cohort without other overt causes of liver disease. This study examined whether HIV-related liver stiffness was associated with markers of immune activation or microbial translocation (MT). A retrospective case-control study of subjects with evidence of liver stiffness as defined by a transient elastography stiffness measurement ≥9.3 kPa (cases=133) and normal controls (n=133) from Rakai, Uganda was performed. Cases were matched to controls by age, gender, HIV, hepatitis B virus (HBV), and highly active antiretroviral therapy (HAART) status. Lipopolysaccharide (LPS), endotoxin IgM antibody, soluble CD14 (sCD14), C-reactive protein (CRP), and D-dimer levels were measured. Conditional logistic regression was used to estimate adjusted matched odds ratios (adjMOR) and 95% confidence intervals. Higher sCD14 levels were associated with a 19% increased odds of liver stiffness (adjMOR=1.19, p=0.002). In HIV-infected individuals, higher sCD14 levels were associated with a 54% increased odds of having liver stiffness (adjMOR=1.54, p<0.001); however, the opposite was observed in HIV-negative individuals (adjMOR=0.57, p=0.001). No other biomarker was significantly associated with liver stiffness, and only one subject was found to have detectable LPS. Liver stiffness in HIV-infected Ugandans is associated with increased sCD14 indicative of monocyte activation in the absence of viral hepatitis or microbial translocation, and suggests that HIV may be directly involved in liver disease.

  16. The slowed brain: cortical oscillatory activity in hepatic encephalopathy.

    PubMed

    Butz, Markus; May, Elisabeth S; Häussinger, Dieter; Schnitzler, Alfons

    2013-08-15

    Oscillatory activity of the human brain has received growing interest as a key mechanism of large-scale integration across different brain regions. Besides a crucial role of oscillatory activity in the emergence of other neurological and psychiatric diseases, recent evidence indicates a key role in the pathophysiology of hepatic encephalopathy (HE). This review summarizes the current knowledge on pathological alterations of oscillatory brain activity in association with liver dysfunction and HE in the context of spontaneous brain activity, motor symptoms, sensory processing, and attention. The existing literature demonstrates a prominent slowing of the frequency of oscillatory activity as shown for spontaneous brain activity at rest, with respect to deficits of motor behavior and motor symptoms, and in the context of visual attention processes. The observed slowing extends across different subsystems of the brain and has been confirmed across different frequency bands, providing evidence for ubiquitous changes of oscillatory activity in HE. For example, the frequency of cortico-muscular coherence in HE patients appears at the frequency of the mini-asterixis (⩽12Hz), while cirrhotics without overt signs of HE show coherence similar to healthy subjects, i.e. at 13-30Hz. Interestingly, the so-called critical flicker frequency (CFF) as a measure of the processing of an oscillating visual stimulus has emerged as a useful tool to quantify HE disease severity, correlating with behavioral and neurophysiological alterations. Moreover, the CFF reliably distinguishes patients with manifest HE from cirrhotics without any signs of HE and healthy controls using a cut-off frequency of 39Hz. In conclusion, oscillatory activity is globally slowed in HE in close association with HE symptoms and disease severity. Although the underlying causal mechanisms are not yet understood, these results indicate that pathological changes of oscillatory activity play an important role in the

  17. Regulation of hepatic lipase activity by sphingomyelin in plasma lipoproteins.

    PubMed

    Yang, Peng; Subbaiah, Papasani V

    2015-10-01

    Hepatic lipase (HL) is an important enzyme in the clearance of triacylglycerol (TAG) from the circulation, and has been proposed to have pro-atherogenic as well as anti-atherogenic properties. It hydrolyzes both phospholipids and TAG of lipoproteins, and its activity is negatively correlated with HDL levels. Although it is known that HL acts preferentially on HDL lipids, the basis for this specificity is not known, since it does not require any specific apoprotein for activity. In this study, we tested the hypothesis that sphingomyelin (SM), whose concentration is much higher in VLDL and LDL compared to HDL, is an inhibitor of HL, and that this could explain the lipoprotein specificity of the enzyme. The results presented show that the depletion of SM from normal lipoproteins activated the HL roughly in proportion to their SM content. SM depletion stimulated the hydrolysis of both phosphatidylcholine (PC) and TAG, although the PC hydrolysis was stimulated more. In the native lipoproteins, HL showed specificity for PC species containing polyunsaturated fatty acids at sn-2 position, and produced more unsaturated lyso PC species. The enzyme also showed preferential hydrolysis of certain TAG species over others. SM depletion affected the specificity of the enzyme towards PC and TAG species modestly. These results show that SM is a physiological inhibitor of HL activity in lipoproteins and that the specificity of the enzyme towards HDL is at least partly due to its low SM content.

  18. Regulation of hepatic lipase activity by sphingomyelin in plasma lipoproteins

    PubMed Central

    Yang, Peng; Subbaiah, Papasani V.

    2015-01-01

    Hepatic lipase (HL) is an important enzyme in the clearance of triacylglycerol (TAG) from the circulation, and has been proposed to have pro-atherogenic as well as anti-atherogenic properties. It hydrolyzes both phospholipids and TAG of lipoproteins, and its activity is negatively correlated with HDL levels. Although it is known that HL acts preferentially on HDL lipids, the basis for this specificity is not known, since it does not require any specific apoprotein for activity. In this study, we tested the hypothesis that sphingomyelin (SM), whose concentration is much higher in VLDL and LDL compared to HDL, is an inhibitor of HL, and that this could explain the lipoprotein specificity of the enzyme. The results presented show that the depletion of SM from normal lipoproteins activated the HL roughly in proportion to their SM content. SM depletion stimulated the hydrolysis of both phosphatidylcholine (PC) and TAG, although the PC hydrolysis was stimulated more. In the native lipoproteins, HL showed specificity for PC species containing polyunsaturated fatty acids at sn-2 position, and produced more unsaturated lyso PC species. The enzyme also showed preferential hydrolysis of certain TAG species over others. SM depletion affected the specificity of the enzyme towards PC and TAG species modestly. These results show that SM is a physiological inhibitor of HL activity in lipoproteins and that the specificity of the enzyme towards HDL is at least partly due to its low SM content. PMID:26193433

  19. Human T cell microparticles circulate in blood of hepatitis patients and induce fibrolytic activation of hepatic stellate cells

    PubMed Central

    Kornek, Miroslaw; Popov, Yury; Libermann, Towia A.; Afdhal, Nezam H.; Schuppan, Detlef

    2010-01-01

    Microparticles (MP) are small cell membrane vesicles which are released from cells during apoptosis or activation. While circulating platelet MP have been studied in some detail, the existence and functional role of T cell MP remain elusive. We show that blood from patients with active hepatitis C (ALT>100 IU/ml) contains elevated numbers of T cell MP compared to patients with mild hepatitis C (ALT<40 IU/ml) and healthy controls. T cell MP fuse with cell membranes of hepatic stellate cells (HSC), the major effector cells for excess matrix deposition in liver fibrosis and cirrhosis. MP uptake is partly ICAM-1 dependent and leads to activation of NFkB and ERK1/2 and subsequent upregulation of fibrolytic genes in HSC, to downregulation of procollagen α1(I) mRNA, and blunting of profibrogenic activities of TGFβ1. Ex vivo the induced fibrolytic activity is evident in MP derived from activated CD4+ T cells, and highest with MP from activated and apoptotic CD8+ T cells. Mass spectrometry, FACS analysis and function blocking antibodies revealed CD147/Emmprin as candidate transmembrane molecule in HSC fibrolytic activation by CD8+ T cell MP. We conclude that 1) circulating T cell MP are a novel diagnostic marker for inflammatory liver diseases, and 2) in vivo induction of T cell MP may be a novel strategy to induce regression of liver fibrosis. PMID:20979056

  20. Antibodies to liver membrane antigens in chronic active hepatitis (CAH). II. Specificity for autoimmune CAH.

    PubMed Central

    Frazer, I H; Kronborg, I J; Mackay, I R

    1983-01-01

    An immunoradiometric assay for IgG class autoantibody to liver membrane antigens, based on serum binding to glutaraldehyde treated monkey hepatocytes, was used to examine sera from patients with chronic active hepatitis (CAH) and other acute and chronic liver diseases. All sera from normals and patients showed binding, up to a titre of 1/2,048. For comparison of assays, results were normalized by selecting two reference sera, one with a high degree of binding, and one from a healthy subject with a low degree of binding: at a dilution of 1/2,048, these sera were given binding values of 100% and 0%. The values for the binding of unknown sera at the same dilution were calculated from these two reference values. For 26 patients with autoimmune CAH, the mean (+/- s.d.) percentage binding value (70 +/- 33%) was significantly higher than the mean value for 26 healthy subjects (10 +/- 15%), and high binding values were significantly associated with biochemically active hepatitis. The mean percentage binding value was moderately increased for eight patients with HBsAg associated CAH (42 +/- 12%), 13 patients with alcoholic hepatitis with cirrhosis (37 +/- 25%) and 45 patients with acute viral hepatitis A (40 +/- 27%) or B (52 +/- 37%). At a cut-off binding value of 65%, the assay as a single diagnostic procedure was shown to have a 70% sensitivity and a 95% specificity for the diagnosis of autoimmune CAH. Better understanding of the pathogenetic significance of antibodies to liver membrane antigens in CAH and other liver diseases will depend upon biochemical analysis of the presumably multiple antigenic determinants on the hepatocyte membrane. PMID:6616969

  1. Statin-activated nuclear receptor PXR promotes SGK2 dephosphorylation by scaffolding PP2C to induce hepatic gluconeogenesis

    PubMed Central

    Gotoh, Saki; Negishi, Masahiko

    2015-01-01

    Statin therapy is known to increase blood glucose levels in humans. Statins utilize pregnane X receptor (PXR) and serum/glucocorticoid regulated kinase 2 (SGK2) to activate phosphoenolpyruvate carboxykinase 1 (PEPCK1) and glucose-6-phosphatase (G6Pase) genes, thereby increasing glucose production in human liver cells. Here, the novel statin/PXR/SGK2-mediated signaling pathway has now been characterized for hepatic gluconeogenesis. Statin-activated PXR scaffolds the protein phosphatase 2C (PP2C) and SGK2 to stimulate PP2C to dephosphorylate SGK2 at threonine 193. Non-phosphorylated SGK2 co-activates PXR-mediated trans-activation of promoters of gluconeogenic genes in human liver cells, thereby enhancing gluconeogenesis. This gluconeogenic statin-PXR-SGK2 signal is not present in mice, in which statin treatment suppresses hepatic gluconeogenesis. These findings provide the basis for statin-associated side effects such as an increased risk for Type 2 diabetes. PMID:26392083

  2. Statin-activated nuclear receptor PXR promotes SGK2 dephosphorylation by scaffolding PP2C to induce hepatic gluconeogenesis.

    PubMed

    Gotoh, Saki; Negishi, Masahiko

    2015-09-22

    Statin therapy is known to increase blood glucose levels in humans. Statins utilize pregnane X receptor (PXR) and serum/glucocorticoid regulated kinase 2 (SGK2) to activate phosphoenolpyruvate carboxykinase 1 (PEPCK1) and glucose-6-phosphatase (G6Pase) genes, thereby increasing glucose production in human liver cells. Here, the novel statin/PXR/SGK2-mediated signaling pathway has now been characterized for hepatic gluconeogenesis. Statin-activated PXR scaffolds the protein phosphatase 2C (PP2C) and SGK2 to stimulate PP2C to dephosphorylate SGK2 at threonine 193. Non-phosphorylated SGK2 co-activates PXR-mediated trans-activation of promoters of gluconeogenic genes in human liver cells, thereby enhancing gluconeogenesis. This gluconeogenic statin-PXR-SGK2 signal is not present in mice, in which statin treatment suppresses hepatic gluconeogenesis. These findings provide the basis for statin-associated side effects such as an increased risk for Type 2 diabetes.

  3. Moderate physical activity promotes basal hepatic autophagy in diet-induced obese mice.

    PubMed

    Rosa-Caldwell, Megan E; Lee, David E; Brown, Jacob L; Brown, Lemuel A; Perry, Richard A; Greene, Elizabeth S; Carvallo Chaigneau, Francisco R; Washington, Tyrone A; Greene, Nicholas P

    2017-02-01

    Obesity is a known risk factor for the development of hepatic disease; obesity-induced fatty liver can lead to inflammation, steatosis, and cirrhosis and is associated with degeneration of the mitochondria. Lifestyle interventions such as physical activity may ameliorate this condition. The purpose of this study was to investigate regulation of mitochondrial and autophagy quality control in liver following Western diet-induced obesity and voluntary physical activity. Eight-week-old C57BL/6J mice were fed a Western diet (WD) or normal chow (NC, control) for 4 weeks; afterwards, groups were divided into voluntary wheel running (VWR) or sedentary (SED) conditions for an additional 4 weeks. WD-SED animals had a median histology score of 2, whereas WD-VWR was not different from NC groups (median score 1). There was no difference in mRNA of inflammatory markers Il6 and Tnfa in WD animals. WD animals had 50% lower mitochondrial content (COX IV and Cytochrome C proteins), 50% lower Pgc1a mRNA content, and reduced content of mitochondrial fusion and fission markers. Markers of autophagy were increased in VWR animals, regardless of obesity, as measured by 50% greater LC3-II/I ratio and 40% lower p62 protein content. BNIP3 protein content was 30% less in WD animals compared with NC animals, regardless of physical activity. Diet-induced obesity results in derangements in mitochondrial quality control that appear to occur prior to the onset of hepatic inflammation. Moderate physical activity appears to enhance basal autophagy in the liver; increased autophagy may provide protection from hepatic fat accumulation.

  4. Acute exposure to high-fat diets increases hepatic expression of genes related to cell repair and remodeling in female rats.

    PubMed

    Miller, Colette N; Morton, Heidi P; Cooney, Paula T; Winters, Tricia G; Ramseur, Keshia R; Rayalam, Srujana; Della-Fera, Mary Anne; Baile, Clifton A; Brown, Lynda M

    2014-01-01

    High-fat diets (HFD) promote the development of both obesity and fatty liver disease through the up-regulation of hepatic lipogenesis. Insulin resistance, a hallmark of both conditions, causes dysfunctional fuel partitioning and increases in lipogenesis. Recent work has demonstrated that systemic insulin resistance occurs in as little as the first 72 hours of an HFD, suggesting the potential for hepatic disruption with HFD at this time point. The current study sought to determine differences in expression of lipogenic genes between sexes in 3-month-old male and female Long-Evans rats after 72 hours of a 40% HFD or a 17% fat (chow) diet. Owing to the response of estrogen on hepatic signaling, we hypothesized that a sexual dimorphic response would occur in the expression of lipogenic enzymes, inflammatory cytokines, apoptotic, and cell repair and remodeling genes. Both sexes consumed more energy when fed an HFD compared with their low fat-fed controls. However, only the males fed the HFD had a significant increase in body fat. Regardless of sex, HFD caused down-regulation of lipogenic and inflammatory genes. Interestingly, females fed an HFD had up-regulated expression of apoptotic and cell repair-related genes compared with the males. This may suggest that females are more responsive to the acute hepatic injury effects caused by HFDs. In summary, neither male nor female rats displayed disrupted hepatic metabolic pathways after 72 hours of the HFD treatment. In addition, female rats appear to have protection from increases in fat deposition, possibly due to increased caloric expenditure; male rats fed an HFD were less active, as demonstrated by distance traveled in their home cage.

  5. Minimal hepatic glucose-6-phosphatase-α activity required to sustain survival and prevent hepatocellular adenoma formation in murine glycogen storage disease type Ia.

    PubMed

    Lee, Young Mok; Kim, Goo-Young; Pan, Chi-Jiunn; Mansfield, Brian C; Chou, Janice Y

    2015-06-01

    Glycogen storage disease type Ia (GSD-Ia), characterized by impaired glucose homeostasis and chronic risk of hepatocellular adenoma (HCA), is caused by a deficiency in glucose-6-phosphatase-α (G6Pase-α or G6PC) activity. In a previous 70-90 week-study, we showed that a recombinant adeno-associated virus (rAAV) vector-mediated gene transfer that restores more than 3% of wild-type hepatic G6Pase-α activity in G6pc (-/-) mice corrects hepatic G6Pase-α deficiency with no evidence of HCA. We now examine the minimal hepatic G6Pase-α activity required to confer therapeutic efficacy. We show that rAAV-treated G6pc (-/-) mice expressing 0.2% of wild-type hepatic G6Pase-α activity suffered from frequent hypoglycemic seizures at age 63-65 weeks but mice expressing 0.5-1.3% of wild-type hepatic G6Pase-α activity (AAV-LL mice) sustain 4-6 h of fast and grow normally to age 75-90 weeks. Despite marked increases in hepatic glycogen accumulation, the AAV-LL mice display no evidence of hepatic abnormalities, hepatic steatosis, or HCA. Interprandial glucose homeostasis is maintained by the G6Pase-α/glucose-6-phosphate transporter (G6PT) complex, and G6PT-mediated microsomal G6P uptake is the rate-limiting step in endogenous glucose production. We show that hepatic G6PT activity is increased in AAV-LL mice. These findings are encouraging for clinical studies of G6Pase-α gene-based therapy for GSD-Ia.

  6. Increasing hepatitis A immunity in men who have sex with men in Sydney, 1996-2012.

    PubMed

    Ali, Hammad; Regan, David G; Guy, Rebecca J; Robertson, Peter; Watchirs-Smith, Lucy; McNulty, Anna M; Donovan, Basil

    2015-09-11

    We examined the hepatitis A virus status of all MSM seen at a large sexual health clinic in inner Sydney between 1996 and 2012. Overall, the proportion of MSM susceptible to hepatitis A decreased from 68.1% in 1996 to 36.2% in 2012; most of this reduction was attributable to vaccination.

  7. Effects of humic acid-metal complexes on hepatic carnitine palmitoyltransferase, carnitine acetyltransferase and catalase activities

    SciTech Connect

    Fungjou Lu; Youngshin Chen . Dept. of Biochemistry); Tienshang Huang . Dept. of Medicine)

    1994-03-01

    A significant increase in activities of hepatic carnitine palmitoyltransferase and carnitine acetyltransferase was observed in male Balb/c mice intraperitoneally injected for 40 d with 0.125 mg/0.1 ml/d humic acid-metal complexes. Among these complexes, the humic acid-As complex was relatively effective, whereas humic acid-25 metal complex was more effective, and humic acid-26 metal complex was most effective. However, humic acid or metal mixtures, or metal such as As alone, was not effective. Humic acid-metal complexes also significantly decreased hepatic catalase activity. A marked decrease of 60-kDa polypeptide in liver cytoplasm was also observed on SDS-polyacrylamide gel electrophoresis after the mice had been injected with the complexes. Morphological analysis of a histopathological biopsy of such treated mice revealed several changes in hepatocytes, including focal necrosis and cell infiltration, mild fatty changes, reactive nuclei, and hypertrophy. Humic acid-metal complexes affect activities of metabolic enzymes of fatty acids, and this results in accumulation of hydrogen peroxide and increase of the lipid peroxidation. The products of lipid peroxidation may be responsible for liver damage and possible carcinogenesis. Previous studies in this laboratory had shown that humic acid-metal complex altered the coagulation system and that humic acid, per se, caused vasculopathy. Therefore, humic acid-metal complexes may be main causal factors of not only so-called blackfoot disease, but also the liver cancer prevailing on the southwestern coast of Taiwan.

  8. Increased Ribozyme Activity in Crowded Solutions*

    PubMed Central

    Desai, Ravi; Kilburn, Duncan; Lee, Hui-Ting; Woodson, Sarah A.

    2014-01-01

    Noncoding RNAs must function in the crowded environment of the cell. Previous small-angle x-ray scattering experiments showed that molecular crowders stabilize the structure of the Azoarcus group I ribozyme, allowing the ribozyme to fold at low physiological Mg2+ concentrations. Here, we used an RNA cleavage assay to show that the PEG and Ficoll crowder molecules increased the biochemical activity of the ribozyme, whereas sucrose did not. Crowding lowered the Mg2+ threshold at which activity was detected and increased total RNA cleavage at high Mg2+ concentrations sufficient to fold the RNA in crowded or dilute solution. After correcting for solution viscosity, the observed reaction rate was proportional to the fraction of active ribozyme. We conclude that molecular crowders stabilize the native ribozyme and favor the active structure relative to compact inactive folding intermediates. PMID:24337582

  9. Diminished acute phase response and increased hepatic inflammation of aged rats in response to intraperitoneal injection of lipopolysaccharide.

    PubMed

    Gomez, Christian R; Acuña-Castillo, Claudio; Pérez, Claudio; Leiva-Salcedo, Elías; Riquelme, Denise M; Ordenes, Gamaliel; Oshima, Kiyoko; Aravena, Mauricio; Pérez, Viviana I; Nishimura, Sumiyo; Sabaj, Valeria; Walter, Robin; Sierra, Felipe

    2008-12-01

    Aging is associated with a deterioration of the acute phase response to inflammatory challenges. However, the nature of these defects remains poorly defined. We analyzed the hepatic inflammatory response after intraperitoneal administration of lipopolysaccharide (LPS) given to Fisher 344 rats aged 6, 15, and 22-23 months. Induction of the acute phase proteins (APPs), haptoglobin, alpha-1-acid glycoprotein, and T-kininogen was reduced and/or retarded with aging. Initial induction of interleukin-6 in aged rats was normal, but the later response was increased relative to younger counterparts. An exacerbated hepatic injury was observed in aged rats receiving LPS, as evidenced by the presence of multiple microabscesses in portal tracts, confluent necrosis, higher neutrophil accumulation, and elevated serum levels of alanine aminotransferase, relative to younger animals. Our results suggest that aged rats displayed a reduced expression of APPs and increased hepatic injury in response to the inflammatory insult.

  10. A physiological increase in insulin suppresses gluconeogenic gene activation in fetal sheep with sustained hypoglycemia.

    PubMed

    Thorn, Stephanie R; Sekar, Satya M; Lavezzi, Jinny R; O'Meara, Meghan C; Brown, Laura D; Hay, William W; Rozance, Paul J

    2012-10-15

    Reduced maternal glucose supply to the fetus and resulting fetal hypoglycemia and hypoinsulinemia activate fetal glucose production as a means to maintain cellular glucose uptake. However, this early activation of fetal glucose production may be accompanied by hepatic insulin resistance. We tested the capacity of a physiological increase in insulin to suppress fetal hepatic gluconeogenic gene activation following sustained hypoglycemia to determine whether hepatic insulin sensitivity is maintained. Control fetuses (CON), hypoglycemic fetuses induced by maternal insulin infusion for 8 wk (HG), and 8 wk HG fetuses that received an isoglycemic insulin infusion for the final 7 days (HG+INS) were studied. Glucose and insulin concentrations were 60% lower in HG compared with CON fetuses. Insulin was 50% higher in HG+INS compared with CON and four-fold higher compared with HG fetuses. Expression of the hepatic gluconeogenic genes, PCK1, G6PC, FBP1, GLUT2, and PGC1A was increased in the HG and reduced in the HG+INS liver. Expression of the insulin-regulated glycolytic and lipogenic genes, PFKL and FAS, was increased in the HG+INS liver. Total FOXO1 protein expression, a gluconeogenic activator, was 60% higher in the HG liver. Despite low glucose, insulin, and IGF1 concentrations, phosphorylation of AKT and ERK was higher in the HG liver. Thus, a physiological increase in fetal insulin is sufficient for suppression of gluconeogenic genes and activation of glycolytic and lipogenic genes in the HG fetal liver. These results demonstrate that fetuses exposed to sustained hypoglycemia have maintained hepatic insulin action in contrast to fetuses exposed to placental insufficiency.

  11. Increased Replicative Fitness Can Lead to Decreased Drug Sensitivity of Hepatitis C Virus

    PubMed Central

    Sheldon, Julie; Beach, Nathan M.; Moreno, Elena; Gallego, Isabel; Piñeiro, David; Martínez-Salas, Encarnación; Gregori, Josep; Quer, Josep; Esteban, Juan Ignacio; Rice, Charles M.

    2014-01-01

    ABSTRACT Passage of hepatitis C virus (HCV) in human hepatoma cells resulted in populations that displayed partial resistance to alpha interferon (IFN-α), telaprevir, daclatasvir, cyclosporine, and ribavirin, despite no prior exposure to these drugs. Mutant spectrum analyses and kinetics of virus production in the absence and presence of drugs indicate that resistance is not due to the presence of drug resistance mutations in the mutant spectrum of the initial or passaged populations but to increased replicative fitness acquired during passage. Fitness increases did not alter host factors that lead to shutoff of general host cell protein synthesis and preferential translation of HCV RNA. The results imply that viral replicative fitness is a mechanism of multidrug resistance in HCV. IMPORTANCE Viral drug resistance is usually attributed to the presence of amino acid substitutions in the protein targeted by the drug. In the present study with HCV, we show that high viral replicative fitness can confer a general drug resistance phenotype to the virus. The results exclude the possibility that genomes with drug resistance mutations are responsible for the observed phenotype. The fact that replicative fitness can be a determinant of multidrug resistance may explain why the virus is less sensitive to drug treatments in prolonged chronic HCV infections that favor increases in replicative fitness. PMID:25122776

  12. Activation of Hepatic STAT3 Maintains Pulmonary Defense during Endotoxemia

    PubMed Central

    Hilliard, Kristie L.; Allen, Eri; Traber, Katrina E.; Kim, Yuri; Wasserman, Gregory A.; Jones, Matthew R.; Mizgerd, Joseph P.

    2015-01-01

    Pneumonia and infection-induced sepsis are worldwide public health concerns. Both pathologies elicit systemic inflammation and induce a robust acute-phase response (APR). Although APR activation is well regarded as a hallmark of infection, the direct contributions of liver activation to pulmonary defense during sepsis remain unclear. By targeting STAT3-dependent acute-phase changes in the liver, we evaluated the role of liver STAT3 activity in promoting host defense in the context of sepsis and pneumonia. We employed a two-hit endotoxemia/pneumonia model, whereby administration of 18 h of intraperitoneal lipopolysaccharide (LPS; 5 mg/kg of body weight) was followed by intratracheal Escherichia coli (106 CFU) in wild-type mice or those lacking hepatocyte STAT3 (hepSTAT3−/−). Pneumonia alone (without endotoxemia) was effectively controlled in the absence of liver STAT3. Following endotoxemia and pneumonia, however, hepSTAT3−/− mice, with significantly reduced levels of circulating and airspace acute-phase proteins, exhibited significantly elevated lung and blood bacterial burdens and mortality. These data suggested that STAT3-dependent liver responses are necessary to promote host defense. While neither recruited airspace neutrophils nor lung injury was altered in endotoxemic hepSTAT3−/− mice, alveolar macrophage reactive oxygen species generation was significantly decreased. Additionally, bronchoalveolar lavage fluid from this group of hepSTAT3−/− mice allowed greater bacterial growth ex vivo. These results suggest that hepatic STAT3 activation promotes both cellular and humoral lung defenses. Taken together, induction of liver STAT3-dependent gene expression programs is essential to countering the deleterious consequences of sepsis on pneumonia susceptibility. PMID:26216424

  13. Inhibitory effect of oestradiol on activation of rat hepatic stellate cells in vivo and in vitro

    PubMed Central

    Shimizu, I; Mizobuchi, Y; Yasuda, M; Shiba, M; Ma, Y; Horie, T; Liu, F; Ito, S

    1999-01-01

    Background—Hepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis. 
Aims—To examine the inhibitory effect of oestradiol on stellate cell activation. 
Methods—In vivo, hepatic fibrosis was induced in rats by dimethylnitrosamine or pig serum. In vitro, rat stellate cells were activated by contact with plastic dishes resulting in their transformation into myofibroblast-like cells. 
Results—In the dimethylnitrosamine and pig serum models, treatment with oestradiol at gestation related doses resulted in a dose dependent suppression of hepatic fibrosis with restored content of hepatic retinyl palmitate, reduced collagen content, lower areas of stellate cells which express α smooth muscle actin (α-SMA) and desmin, and lower procollagen type I and III mRNA levels in the liver. In cultured stellate cells, oestradiol inhibited type I collagen production, α-SMA expression, and cell proliferation. These findings suggest that oestradiol is a potent inhibitor of stellate cell transformation. 
Conclusion—The antifibrogenic role of oestradiol in the liver may contribute to the sex associated differences in the progression from hepatic fibrosis to cirrhosis. 

 Keywords: hepatic stellate cells; hepatic fibrosis; oestradiol; α smooth muscle actin; retinyl palmitate PMID:9862839

  14. Pregnane X receptor activation and silencing promote steatosis of human hepatic cells by distinct lipogenic mechanisms.

    PubMed

    Bitter, Andreas; Rümmele, Petra; Klein, Kathrin; Kandel, Benjamin A; Rieger, Jessica K; Nüssler, Andreas K; Zanger, Ulrich M; Trauner, Michael; Schwab, Matthias; Burk, Oliver

    2015-11-01

    In addition to its well-characterized role in the regulation of drug metabolism and transport by xenobiotics, pregnane X receptor (PXR) critically impacts on lipid homeostasis. In mice, both ligand-dependent activation and knockout of PXR were previously shown to promote hepatic steatosis. To elucidate the respective pathways in human liver, we generated clones of human hepatoma HepG2 cells exhibiting different PXR protein levels, and analyzed effects of PXR activation and knockdown on steatosis and expression of lipogenic genes. Ligand-dependent activation as well as knockdown of PXR resulted in increased steatosis in HepG2 cells. Activation of PXR induced the sterol regulatory element-binding protein (SREBP) 1-dependent lipogenic pathway via PXR-dependent induction of SREBP1a, which was confirmed in primary human hepatocytes. Inhibiting SREBP1 activity by blocking the cleavage-dependent maturation of SREBP1 protein impaired the induction of lipogenic SREBP1 target genes and triglyceride accumulation by PXR activation. On the other hand, PXR knockdown resulted in up-regulation of aldo-keto reductase (AKR) 1B10, which enhanced the acetyl-CoA carboxylase (ACC)-catalyzed reaction step of de novo lipogenesis. In a cohort of human liver samples histologically classified for non-alcoholic fatty liver disease, AKR1B10, SREBP1a and SREBP1 lipogenic target genes proved to be up-regulated in steatohepatitis, while PXR protein was reduced. In summary, our data suggest that activation and knockdown of PXR in human hepatic cells promote de novo lipogenesis and steatosis by induction of the SREBP1 pathway and AKR1B10-mediated increase of ACC activity, respectively, thus providing mechanistic explanations for a putative dual role of PXR in the pathogenesis of steatohepatitis.

  15. Effect of malonate and p-chlorophenoxy acetic acid on hepatic succinic dehydrogenase activity of ageing lizards.

    PubMed

    Jena, B S; Patnaik, B K

    1990-01-01

    The degree of inhibition of hepatic succinic dehydrogenase activity by malonate, a competitive inhibitor, did not differ between young and middle-aged lizards. On the other hand, the same parameter increased significantly between middle-aged and old lizards. The percent inhibition of enzyme activity by p-chlorophenoxy acetic acid was also age-dependent, being higher in middle-aged and old than in young lizards.

  16. Early activated hepatic stellate cell-derived molecules reverse acute hepatic injury

    PubMed Central

    Chang, Wen-Ju; Song, Lu-Jun; Yi, Tuo; Shen, Kun-Tang; Wang, Hong-Shan; Gao, Xiao-Dong; Li, Min; Xu, Jian-Min; Niu, Wei-Xin; Qin, Xin-Yu

    2015-01-01

    AIM: To test whether hepatic stellate cells (HSCs) at different activation stages play different roles in acetaminophen (APAP)-induced acute liver injury (ALI). METHODS: HSCs were isolated from mouse liver and cultured in vitro. Morphological changes of initiation HSCs [HSCs (5d)] and perpetuation HSCs [HSCs (p3)] were observed by immunofluorescence and transmission electron microscopy. The protective effects of HSC-derived molecules, cell lysates and HSC-conditioned medium (HSC-CM) were tested in vivo by survival and histopathological analyses. Liver injury was determined by measuring aminotransferase levels in the serum and by histologic examination of tissue sections under a light microscope. Additionally, to determine the molecular mediators of the observed protective effects of initiation HSCs, we examined HSC-CM using a high-density protein array. RESULTS: HSCs (5d) and HSCs (p3) had different morphological and phenotypic traits. HSCs (5d) presented a star-shaped appearance with expressing α-SMA at non-uniform levels between cells. However, HSCs (p3) evolved into myofibroblast-like cells without lipid droplets and expressed a uniform and higher level of α-SMA. HSC-CM (5d), but not HSC-CM (p3), provided a significant survival benefit and showed a dramatic reduction of hepatocellular necrosis and panlobular leukocyte infiltrates in mice exposed to APAP. However, this protective effect was abrogated at higher cell masses, indicating a therapeutic window of effectiveness. Furthermore, the protein array screen revealed that HSC-CM (5d) was composed of many chemokines and growth factors that correlated with inflammatory inhibition and therapeutic activity. When compared with HSC-CM (p3), higher levels of monocyte chemoattractant protein-1, macrophage inflammatory protein-1γ, hepatocyte growth factor, interleukin-10, and matrix metalloproteinase-2, but lower levels of stem cell factor and Fas-Ligand were observed in HSC-CM (5d). CONCLUSION: These data indicated

  17. Induction of apoptosis by tanshinone I via cytochrome c release in activated hepatic stellate cells.

    PubMed

    Kim, Ji Young; Kim, Kyoung Mi; Nan, Ji-Xing; Zhao, Yu Zhe; Park, Pil-Hoon; Lee, Sang Jun; Sohn, Dong Hwan

    2003-04-01

    Hepatic stellate cells play central roles in hepatic fibrosis. The therapeutic goal in hepatic fibrosis is to halt or reverse fibrosis. Apoptosis is suggested to eliminate activated hepatic stellate cells in fibrosis. Salvia miltiorrhiza is a traditional medicine used to improve blood circulation and treat chronic hepatitis and hepatic fibrosis. We investigated the effect of tanshinone I, an ingredient of Salvia miltiorrhiza, on the apoptotic death of rat hepatic stellate cells transformed by simian virus 40 (T-HSC/Cl-6), which retains the features of activated stellate cells. Treatment of T-HSC/Cl-6 cells with tanshinone I resulted in the induction of typical DNA fragmentation and DNA ladder formation in a concentration- and time-dependent manner. The induction of apoptosis was confirmed by flow cytometric analysis. Treatment of T-HSC/Cl-6 cells with tanshinone I caused activation of caspase-3 and subsequent proteolytic cleavage of poly(ADP-ribose) polymerase. Tanshinone I induced mitochondrial membrane dipolarization and the release of cytochrome c from mitochondria into the cytosol. In conclusion, our results demonstrate that tanshinone I induces apoptosis of T-HSC/Cl-6 cells and that tanshinone I-induced apoptosis involves caspase activation through cytochrome c release and loss of mitochondrial membrane potential.

  18. The anti-hepatic fibrosis activity of ergosterol depended on upregulation of PPARgamma in HSC-T6 cells.

    PubMed

    Tai, Chen-Jei; Choong, Chen-Yen; Lin, Yu-Chun; Shi, Yeu-Ching; Tai, Cheng-Jeng

    2016-04-01

    Advanced glycation endproducts (AGEs) were shown to play an important role in metabolic syndrome and were suggested to contribute to the development of hepatic fibrosis. Evidence indicates that AGEs resulted in hepatic fibrosis coupled to the activation of the receptor for AGEs (RAGE) in hepatic stellate cells (HSCs). NADPH oxidase is downstream of the RAGE signaling pathway, resulting in an increase in reactive oxygen species (ROS), alpha-smooth muscle actin (alpha-SMA), RAGE, and matrix metalloproteinase-9 (MMP-9). This study was designed to evaluate the effects of ergosterol on RAGE signaling in HSC-T6 cells. Ergosterol suppressed the activation of HSC-T6 cells induced by AGEs, and attenuated overexpressions of alpha-SMA, MMP-9, and epithelial-mesenchymal transition (EMT) markers, including N-cadherin and vimentin. We also found that these inhibitory effects of ergosterol on the activation of HSCs were dependent on peroxisome proliferator-activated receptor-gamma (PPARgamma) confirmed by PPARgamma reporter assay and PPARgamma knockdown. In addition, ergosterol also showed an inhibitory effect on the generation of AGEs, fructosamine, and α-dicarbonyl compounds in this study. Our results show that ergosterol can be used as a protective agent against hepatic fibrosis caused by induction of AGEs.

  19. Hepatitis B

    MedlinePlus

    ... times more infectious than HIV. Which adults need hepatitis B vaccine? Any sexually active adult who is not in ... share needles, syringes, or other drug-injection equipment. Hepatitis B vaccine is available alone or in a combination with ...

  20. Baseline HBV load increases the risk of anti-tuberculous drug-induced hepatitis flares in patients with tuberculosis.

    PubMed

    Zhu, Chun-Hui; Zhao, Man-Zhi; Chen, Guang; Qi, Jun-Ying; Song, Jian-Xin; Ning, Qin; Xu, Dong

    2017-02-01

    Hepatitis associated anti-tuberculous treatment (HATT) has been a main obstacle in managing patients co-infected with Mycobacterium tuberculosis and hepatitis B virus (HBV). Therefore, we evaluated the factors related to the severity of adverse effects during HATT, especially those associated with liver failure. A retrospective study was carried out at Tongji Hospital from 2007 to 2012. Increases in serum transaminase levels of >3, 5, and 10 times the upper limit of normal (ULN) were used to define liver damage as mild, moderate, and severe, respectively. Patients with elevated total bilirubin (TBil) levels that were more than 10 times the ULN (>171 μmol/L) with or without decreased (<40%) prothrombin activity (PTA) were diagnosed with liver failure. A cohort of 87 patients was analyzed. The incidence of liver damage and liver failure was 59.8% (n=52) and 25.3% (n=22), respectively. The following variables were correlated with the severity of hepatotoxicity: albumin (ALB) levels, PTA, platelet counts (PLT), and the use of antiretroviral therapies (P<0.05). Hypo-proteinemia and antiretroviral therapy were significantly associated with liver failure, and high viral loads were a significant risk factor with an odds ratio (OR) of 2.066. Judicious follow-up of clinical conditions, liver function tests, and coagulation function, especially in patients with high HBV loads and hypoalbuminemia is recommended. It may be advisable to reconsider the use of antiviral drugs failure during the course of anti-tuberculous treatment of HBV infection patients to avoid the occurrence of furious liver failure.

  1. Activation of Hepatic Lipase Expression by Oleic Acid: Possible Involvement of USF1

    PubMed Central

    van Deursen, Diederik; van Leeuwen, Marije; Akdogan, Deniz; Adams, Hadie; Jansen, Hans; Verhoeven, Adrie J.M.

    2009-01-01

    Polyunsaturated fatty acids affect gene expression mainly through peroxisome proliferator-activated receptors (PPARs) and sterol regulatory element binding proteins (SREBPs), but how monounsaturated fatty acids affect gene expression is poorly understood. In HepG2 cells, oleate supplementation has been shown to increase secretion of hepatic lipase (HL). We hypothesized that oleate affects HL gene expression at the transcriptional level. To test this, we studied the effect of oleate on HL promoter activity using HepG2 cells and the proximal HL promoter region (700 bp). Oleate increased HL expression and promoter activity 1.3–2.1 fold and reduced SREBP activity by 50%. Downregulation of SREBP activity by incubation with cholesterol+25-hydroxycholesterol had no effect on HL promoter activity. Overexpression of SREBP2, but not SREBP1, reduced HL promoter activity, which was effected mainly through the USF1 binding site at -307/-312. Oleate increased the nuclear abundance of USF1 protein 2.7 ± 0.6 fold, while USF1 levels were reduced by SREBP2 overexpression. We conclude that oleate increases HL gene expression via USF1. USF1 may be an additional fatty acid sensor in liver cells. PMID:22253973

  2. Hepatic insulin signaling changes: possible mechanism in prenatal hypoxia-increased susceptibility of fatty liver in adulthood.

    PubMed

    Cao, Li; Mao, Caiping; Li, Shigang; Zhang, Yujuan; Lv, Juanxiu; Jiang, Shan; Xu, Zhice

    2012-10-01

    Nonalcoholic fatty liver disease (NAFLD) is strongly linked to insulin resistance. Prenatal hypoxia (PH) is a risk factor in programming of insulin resistance, glucose intolerance, and metabolic dysfunctions in later life, although the mechanisms are unclear. In this study, the role of metabolic and histological changes as well as the hepatic insulin signaling mechanisms were determined in increasing susceptibility of NAFLD in the fetus and offspring exposed to PH. Pregnant rats exposed to hypoxia (O(2) 10%) during pregnancy demonstrated decreased fetal body and liver weight as well as liver to body weight ratio, whereas these changes were not observed in the offspring. However, male liver to body weight ratio increased after PH stress. Microscopic analysis demonstrated that exposure to PH resulted in distorted architecture of the hepatic parenchyma cells with reduced cellularity in the fetus and offspring. Blood glucose and insulin levels were lower with enhanced insulin sensitivity and increased expression of hepatic insulin-signaling elements in the fetus. Furthermore, insulin resistance, impaired glucose homeostasis, and altered expression of insulin-signaling elements occurred in the offspring. Postnatal hypoxia increased hepatic lipid droplets and triglyceride in liver, whereas expressions of insulin-signaling elements were less in the offspring exposed to PH except glucose transporters 2. The results indicated that PH contributed to hepatocyte heteroplasia and metabolic changes that enhanced vulnerability for NAFLD in the offspring, probably via affecting insulin signaling pathway, including glucose transporters 2.

  3. Theaflavins attenuate hepatic lipid accumulation through activating AMPK in human HepG2 cells.

    PubMed

    Lin, Chih-Li; Huang, Hsiu-Chen; Lin, Jen-Kun

    2007-11-01

    Black tea is one of the world's most popular beverages, and its health-promoting effects have been intensively investigated. The antiobesity and hypolipidemic effects of black tea have attracted increasing interest, but the mechanisms underlying these phenomena remain unclear. In the present study, the black tea major component theaflavins were assessed for their hepatic lipid-lowering potential when administered in fatty acid overload conditions both in cell culture and in an animal experimental model. We found that theaflavins significantly reduced lipid accumulation, suppressed fatty acid synthesis, and stimulated fatty acid oxidation. Furthermore, theaflavins also inhibited acetyl-coenzyme A carboxylase activities by stimulating AMP-activated protein kinase (AMPK) through the LKB1 and reactive oxygen species pathways. These observations support the idea that AMPK is a critical component of decreased hepatic lipid accumulation by theaflavin treatments. Our results show that theaflavins are bioavailable both in vitro and in vivo and may be active in the prevention of fatty liver and obesity.

  4. E hepatitis seroprevalence in a population of patients with transaminases increased at Le Mans' hospital (France).

    PubMed

    Mingam, Anna; Cussac, Vincent; Kaabar, Mohamed; Pineau-Vincent, Fabienne

    2016-06-01

    In Europe, infection through the hepatitis E virus presents itself under the form of autochthone, sporadic cases with zoonotic transmission. The diagnosis is more frequent in the case of male subjects above 50, with a generally severe clinical presentation. Moreover, a transition to chronicity is described in the case of immunocompromised patients. In France and in the world, seroprevalence has not clearly been established yet. In the hospital of Le Mans, Sarthe, France, the serologic status regarding the hepatitis E virus was established between October 1(st) 2012 and April 3(rd) 2015 on a population of 299 patients who presented hypertransaminasaemia and negative serology regarding hepatitis A, B and C viruses. According to the Wantai(®) Assays technique, seroprevalence for IgG among this cohort was 26.1%, while 3.7% of patients presented acute hepatitis E and a positive IgM serology. Hepatitis E screening tests are indispensable in the context of acute hepatitis no A, no B, no C.

  5. Lamivudine/Adefovir Treatment Increases the Rate of Spontaneous Mutation of Hepatitis B Virus in Patients

    PubMed Central

    Pereira-Gómez, Marianoel; Bou, Juan-Vicente; Andreu, Iván; Sanjuán, Rafael

    2016-01-01

    The high levels of genetic diversity shown by hepatitis B virus (HBV) are commonly attributed to the low fidelity of its polymerase. However, the rate of spontaneous mutation of human HBV in vivo is currently unknown. Here, based on the evolutionary principle that the population frequency of lethal mutations equals the rate at which they are produced, we have estimated the mutation rate of HBV in vivo by scoring premature stop codons in 621 publicly available, full-length, molecular clone sequences derived from patients. This yielded an estimate of 8.7 × 10−5 spontaneous mutations per nucleotide per cell infection in untreated patients, which should be taken as an upper limit estimate because PCR errors and/or lack of effective lethality may inflate observed mutation frequencies. We found that, in patients undergoing lamivudine/adefovir treatment, the HBV mutation rate was elevated by more than sixfold, revealing a mutagenic effect of this treatment. Genome-wide analysis of single-nucleotide polymorphisms indicated that lamivudine/adefovir treatment increases the fraction of A/T-to-G/C base substitutions, consistent with recent work showing similar effects of lamivudine in cellular DNA. Based on these data, the rate at which HBV produces new genetic variants in treated patients is similar to or even higher than in RNA viruses. PMID:27649318

  6. Receptor channel TRPC6 orchestrate the activation of human hepatic stellate cell under hypoxia condition

    SciTech Connect

    Iyer, Soumya C; Kannan, Anbarasu; Gopal, Ashidha; Devaraj, Niranjali; Halagowder, Devaraj

    2015-08-01

    Hepatic stellate cells (HSCs), a specialized stromal cytotype have a great impact on the biological behaviors of liver diseases. Despite this fact, the underlying mechanism that regulates HSC still remains poorly understood. The aim of the present study was to understand the role of TRPC6 signaling in regulating the molecular mechanism of HSCs in response to hypoxia. In the present study we showed that under hypoxia condition, the upregulated Hypoxia Inducible Factor 1α (HIF1α) increases NICD activation, which in turn induces the expression of transient receptor potential channel 6 (TRPC6) in HSC line lx-2. TRPC6 causes a sustained elevation of intracellular calcium which is coupled with the activation of the calcineurin-nuclear factor of activated T-cell (NFAT) pathway which activates the synthesis of extracellular matrix proteins. TRPC6 also activates SMAD2/3 dependent TGF-β signaling in facilitating upregulated expression of αSMA and collagen. As activated HSCs may be a suitable target for HCC therapy and targeting these cells rather than the HCC cells may result in a greater response. Collectively, our studies indicate for the first time the detailed mechanism of activation of HSC through TRPC6 signaling and thus being a promising therapeutic target. - Highlights: • HIF1α increases NICD, induces TRPC6 in lx2 cells. • TRPC6 a novel regulator in the activation of HSC. • HSCs as target for HCC therapy.

  7. Attenuated viral hepatitis in Trem1−/− mice is associated with reduced inflammatory activity of neutrophils

    PubMed Central

    Kozik, Jan-Hendrik; Trautmann, Tanja; Carambia, Antonella; Preti, Max; Lütgehetmann, Marc; Krech, Till; Wiegard, Christiane; Heeren, Joerg; Herkel, Johannes

    2016-01-01

    TREM1 (Triggering Receptor Expressed on Myeloid Cells 1) is a pro-inflammatory receptor expressed by phagocytes, which can also be released as a soluble molecule (sTREM1). The roles of TREM1 and sTREM1 in liver infection and inflammation are not clear. Here we show that patients with hepatitis B virus (HBV) or hepatitis C virus (HCV) infection manifest elevated serum levels of sTREM1. In mice, experimental viral hepatitis induced by infection with Lymphocytic Choriomeningitis Virus (LCMV)-WE was likewise associated with increased sTREM1 in serum and urine, and with increased TREM1 and its associated adapter molecule DAP12 in the liver. Trem1−/− mice showed accelerated clearance of LCMV-WE and manifested attenuated liver inflammation and injury. TREM1 expression in the liver of wild-type mice was mostly confined to infiltrating neutrophils, which responded to LCMV by secretion of CCL2 and TNF-α, and release of sTREM1. Accordingly, the production of CCL2 and TNF-α was decreased in the livers of LCMV-infected Trem1−/− mice, as compared to LCMV-infected wildtype mice. These findings indicate that TREM1 plays a role in viral hepatitis, in which it seems to aggravate the immunopathology associated with viral clearance, mainly by increasing the inflammatory activity of neutrophils. PMID:27328755

  8. Pharmacokinetics and hepatic uptake of eltrombopag, a novel platelet-increasing agent.

    PubMed

    Takeuchi, Kazuya; Sugiura, Tomoko; Umeda, Saki; Matsubara, Kazuki; Horikawa, Masato; Nakamichi, Noritaka; Silver, David L; Ishiwata, Norihisa; Kato, Yukio

    2011-06-01

    Eltrombopag (ELT) is a novel thrombopoietin receptor agonist for the treatment of idiopathic thrombocytopenic purpura. Previous reports indicate that ELT is mainly eliminated in the liver, although its pharmacokinetic profile has not yet been clarified in detail. The purpose of the present study is to investigate the overall elimination mechanism of ELT. After intravenous administration of ELT to rats, approximately 40% of unchanged ELT was excreted into the bile in 72 h, whereas less than 0.02% of the dose was excreted in urine, indicating that liver is the major elimination organ for ELT. The total clearance was much lower than the hepatic blood flow rate and comparable with hepatic uptake clearance obtained from integration plot analysis. Coadministration of rifampicin, an organic anion transporter inhibitor, reduced both total clearance and hepatic uptake clearance of ELT. These results suggest that hepatic uptake is the rate-limiting process in the overall elimination of ELT. To further characterize the uptake mechanism, uptake of ELT by freshly isolated mouse hepatocytes was examined. The ELT uptake showed concentration and energy dependence and was inhibited by various compounds, including not only organic anions but also organic cations. Hepatic uptake clearance in vivo was reduced by coadministration of an organic cation, tetrapentylammonium. Finally, uptake of ELT was observed in human embryonic kidney 293 cells transfected with human hepatic transporters organic anion-transporting polypeptide (OATP) 1B1 and OATP2B1 and organic cation transporter OCT1. These results suggest that multiple transporters, including organic anion transporters and organic cation transporters, are involved in hepatic ELT uptake.

  9. Mobilization of hepatic calcium pools by platelet activating factor

    SciTech Connect

    Lapointe, D.S.; Hanahan, D.J.; Olson, M.S.

    1987-03-24

    In the perfused rat liver, platelet activating factor, 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (AGEPC), infusion produces an extensive but transient glycogenolytic response which at low AGEPC concentrations is markedly dependent upon the perfusate calcium levels. The role of calcium in the glycogenolytic response of the liver to AGEPC was investigated by assessing the effect of AGEPC on various calcium pools in the intact liver. Livers from fed rats were equilibrated with /sup 45/Ca/sup 2 +/, and the kinetics of /sup 45/Ca/sup 2 +/ efflux were determined in control, AGEPC-stimulated, and phenylephrine-stimulated livers during steady-state washout of /sup 45/Ca/sup 2 +/. AGEPC treatment had only a slight if any effect on the pattern of steady-state calcium efflux from the liver, as opposed to major perturbations in the pattern of calcium efflux effected by the ..cap alpha..-adrenergic agonist phenylephrine. Infusion of short pulses of AGEPC during the washout of /sup 45/Ca/sup 2 +/ from labeled livers caused a transient release of /sup 45/Ca/sup 2 +/ which was not abolished at low calcium concentrations in the perfusate. Infusion of latex beads, which are removed by the reticuloendothelial cells, caused the release of hepatic /sup 45/Ca/sup 2 +/ in a fashion similar to the case with AGEPC. The findings indicate that AGEPC does not perturb a major pool of calcium within the liver as occurs upon ..cap alpha..-adrenergic stimulation; it is likely that AGEPC mobilizes calcium from a smaller yet very important pool, very possibly from nonparenchymal cells in the liver.

  10. Activation of α2 adrenoceptor attenuates lipopolysaccharide-induced hepatic injury.

    PubMed

    Chen, Jing-Hui; Yu, Gao-Feng; Jin, Shang-Yi; Zhang, Wen-Hua; Lei, Dong-Xu; Zhou, Shao-Li; Song, Xing-Rong

    2015-01-01

    Sepsis induces hepatic injury but whether alpha-2 adrenoceptor (α2-AR) modulates the severity of sepsis-induced liver damage remains unclear. The present study used lipopolysaccharide (LPS) to induce hepatic injury and applied α2-AR agonist dexmedetomidine (DEX) and/or antagonist yohimbine to investigate the contribution of α2-AR in LPS-induced liver injury. Our results showed that LPS resulted in histological and functional abnormality of liver tissue (ALT and AST transaminases, lactate), higher mortality, an increase in proinflammatory cytokines (IL-1β, IL-6 & TNF-α), as well as a change in oxidative stress (MDA, SOD). Activation of α2-AR by dexmedetomidine (DEX) attenuated LPS-induced deleterious effects on the liver and block of α2-AR by yohimbine aggravated LPS-induced liver damage. Our data suggest that α2-AR plays an important role in sepsis-induced liver damage and activation of α2-AR with DEX could be a novel therapeutic avenue to protect the liver against sepsis-induced injury.

  11. Diurnal locomotor activity and oxidative metabolism of the suprachiasmatic nucleus in two models of hepatic insufficiency.

    PubMed

    Lopez, Laudino; Cimadevilla, Jose M; Aller, Maria A; Arias, Jaime; Nava, M Paz; Arias, Jorge L

    2003-08-15

    Subjects with hepatic cirrhosis develop alterations of several rhythmic behavioural and biochemical patterns. Since most cirrhotic patients combine portal hypertension and hepatic impairment, our work aims to assess the extent to which rhythmical changes can be due to hepatic insufficiency or portal hypertension. This was done using two experimental models in rats, portacaval shunt model (PC) and portal hypertension by a triple stenosing ligature of the portal vein (PH). We assess diurnal locomotor activity and determine the oxidative metabolism of the suprachiasmatic nucleus (SCN) by histochemical determination of cytochrome oxidase (COX). The results show that animals with PC have altered diurnal locomotor rhythm compared to control and PH rats (p<0.001). They also present lower COX activity in the SCN (p<0.05). We conclude that rhythmic alterations are due to hepatic insufficiency and not to portal hypertension.

  12. Interferon regulatory factor-1 activates autophagy to aggravate hepatic ischemia-reperfusion injury via the P38/P62 pathway in mice

    PubMed Central

    Yu, Yao; Li, Shipeng; Wang, Zhen; He, Jindan; Ding, Yijie; Zhang, Haiming; Yu, Wenli; Shi, Yiwei; Cui, Zilin; Wang, Ximo; Wang, Zhiliang; Sun, Liying; Zhang, Rongxin; Du, Hongyin; Zhu, Zhijun

    2017-01-01

    Increasing evidence has linked autophagy to a detrimental role in hepatic ischemia- reperfusion (IR) injury (IRI). Here we focus on the role of interferon regulatory factor-1 (IRF-1) in regulating autophagy to aggravate hepatic IRI. We found that IRF-1 was up-regulated during hepatic IRI and was associated with an activation of the autophagic signaling. This increased IRF-1 expression, which was allied with high autophagic activity, amplified liver damage to IR, an effect which was abrogated by IRF-1 depletion. Moreover, IRF-1 contributed to P38 induced autophagic and apoptotic cell death, that can play a key role in liver dysfunction. The levels of P62 mRNA and protein were increased when P38 was activated and decreased when P38 was inhibited by SB203580. We conclude that IRF-1 functioned as a trigger to activate autophagy via P38 activation and that P62 was required for this P38-mediated autophagy. IRF-1 appears to exert a pivotal role in hepatic IRI, by predisposing hepatocytes to activate an autophagic pathway. Such an effect promotes autophagic cell death through the P38/P62 pathway. The identification of this novel pathway, that links expression levels of IRF-1 with autophagy, may provide new insights for the generation of novel protective therapies directed against hepatic IRI. PMID:28266555

  13. Berberine reverts hepatic mitochondrial dysfunction in high-fat fed rats: a possible role for SirT3 activation.

    PubMed

    Teodoro, João Soeiro; Duarte, Filipe Valente; Gomes, Ana Patrícia; Varela, Ana Teresa; Peixoto, Francisco Manuel; Rolo, Anabela Pinto; Palmeira, Carlos Marques

    2013-11-01

    Berberine is an isoquinoline alkaloid with anti-diabetic properties. Despite the central role of liver and thus hepatic mitochondria in whole-body metabolism, berberine effects on hepatic mitochondrial function in an obesity model are still unknown. Here, we demonstrate that berberine treatment recovers mitochondrial efficiency when altered by a high-fat feeding. Mitochondria isolated from the liver of high-fat fed rats exhibited decreased capacity to accumulate calcium and impaired oxidative phosphorylation (OXPHOS) capacity, as shown by impaired mitochondrial membrane potential, oxygen consumption and cellular ATP levels. Interestingly, the recovery of mitochondrial function by berberine was associated with an increased activity of the mitochondrial sirtuin 3 (SirT3). In conclusion, berberine potent protective effects against metabolic syndrome may rely on increasing mitochondrial SirT3 activity, normalizing mitochondrial function and preventing a state of energetic deficit caused by impaired OXPHOS.

  14. Expression of scavenger receptor‐AI promotes alternative activation of murine macrophages to limit hepatic inflammation and fibrosis

    PubMed Central

    Labonte, Adam C.; Sung, Sun‐Sang J.; Jennelle, Lucas T.; Dandekar, Aditya P.

    2016-01-01

    The liver maintains an immunologically tolerant environment as a result of continuous exposure to food and bacterial constituents from the digestive tract. Hepatotropic pathogens can take advantage of this niche and establish lifelong chronic infections causing hepatic fibrosis and hepatocellular carcinoma. Macrophages (Mϕ) play a critical role in regulation of immune responses to hepatic infection and regeneration of tissue. However, the factors crucial for Mϕ in limiting hepatic inflammation or resolving liver damage have not been fully understood. In this report, we demonstrate that expression of C‐type lectin receptor scavenger receptor‐AI (SR‐AI) is crucial for promoting M2‐like Mϕ activation and polarization during hepatic inflammation. Liver Mϕ uniquely up‐regulated SR‐AI during hepatotropic viral infection and displayed increased expression of alternative Mϕ activation markers, such as YM‐1, arginase‐1, and interleukin‐10 by activation of mer receptor tyrosine kinase associated with inhibition of mammalian target of rapamycin. Expression of these molecules was reduced on Mϕ obtained from livers of infected mice deficient for the gene encoding SR‐AI (msr1). Furthermore, in vitro studies using an SR‐AI‐deficient Mϕ cell line revealed impeded M2 polarization and decreased phagocytic capacity. Direct stimulation with virus was sufficient to activate M2 gene expression in the wild‐type (WT) cell line, but not in the knockdown cell line. Importantly, tissue damage and fibrosis were exacerbated in SR‐AI–/– mice following hepatic infection and adoptive transfer of WT bone‐marrow–derived Mϕ conferred protection against fibrosis in these mice. Conclusion: SR‐AI expression on liver Mϕ promotes recovery from infection‐induced tissue damage by mediating a switch to a proresolving Mϕ polarization state. (Hepatology 2017;65:32‐43). PMID:27770558

  15. Activated Notch signaling is required for hepatitis B virus X protein to promote proliferation and survival of human hepatic cells.

    PubMed

    Wang, Fan; Zhou, Haiyan; Xia, Xiumei; Sun, Qian; Wang, Ying; Cheng, Bin

    2010-12-01

    Hepatitis B virus X protein (HBx) is a multifunctional oncoprotein which plays a crucial role in the pathogenesis of hepatocellular carcinoma (HCC). However, the exact mechanisms remain controversial. Here we show that HBx strongly stimulated cell growth, promoted cell cycle progression and inhibited apoptosis of human non-tumor hepatic cell line L02 cells. It also accelerated tumor formation of L02 cells in BALB/c nude mice. Furthermore, Notch signaling components were upregulated in HBx-expressing L02 cells compared to normal L02 cells. However, blocking Notch signaling with a γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) attenuated cell growth, shortened the S phase of cell cycle and promoted apoptosis of HBx-expressing L02 cell in a dose- and time-dependent manner, but normal L02 cells were not significantly affected by Notch signaling blocking. Therefore, our findings demonstrate that HBx could promote the growth of human non-tumor hepatic cell line L02 cells both in vitro and in vivo, which may require the activation of Notch signaling pathway.

  16. Cluster-Randomized Trial to Increase Hepatitis B Testing among Koreans in Los Angeles

    PubMed Central

    Bastani, Roshan; Glenn, Beth A.; Maxwell, Annette E.; Jo, Angela M.; Herrmann, Alison K.; Crespi, Catherine M.; Wong, Weng K.; Chang, L. Cindy; Stewart, Susan L.; Nguyen, Tung T.; Chen, Moon S.; Taylor, Victoria M.

    2015-01-01

    Background In the United States, Korean immigrants experience a disproportionately high burden of chronic hepatitis B (HBV) viral infection and associated liver cancer compared to the general population. However, despite clear clinical guidelines, HBV serologic testing among Koreans remains persistently sub-optimal. Methods We conducted a cluster-randomized trial to evaluate a church-based small group intervention to improve HBV testing among Koreans in Los Angeles. Fifty-two Korean churches, stratified by size (small, medium, large) and location (Koreatown versus other), were randomized to intervention or control conditions. Intervention church participants attended a single-session small-group discussion on liver cancer and HBV testing and control church participants attended a similar session on physical activity and nutrition. Outcome data consisted of self-reported HBV testing obtained via 6-month telephone follow-up interviews. Results We recruited 1123 individuals, 18-64 years of age, across the 52 churches. Ninety-two percent of the sample attended the assigned intervention session and 86% completed the 6-month follow-up. Sample characteristics included: mean age 46 years, 65% female, 97% born in Korea, 69% completed some college, and 43% insured. In an intent-to-treat analysis, the intervention produced a statistically significant effect (OR = 4.9, p < .001), with 19% of intervention and 6% of control group participants reporting a HBV test. Conclusion Our intervention was successful in achieving a large and robust effect in a population at high risk of HBV infection and sequelae. Impact The intervention was fairly resource efficient and thus has high potential for replication in other high-risk Asian groups. PMID:26104909

  17. Age-Dependent Hepatic UDP-Glucuronosyltransferase Gene Expression and Activity in Children

    PubMed Central

    Neumann, Elizabeth; Mehboob, Huma; Ramírez, Jacqueline; Mirkov, Snezana; Zhang, Min; Liu, Wanqing

    2016-01-01

    UDP-glucuronosyltransferases (UGTs) are important phase II drug metabolism enzymes. The aim of this study was to explore the relationship between age and changes in mRNA expression and activity of major human hepatic UGTs, as well as to understand the potential regulatory mechanism underlying this relationship. Using previously generated data, we investigated age-dependent mRNA expression levels of 11 hepatic UGTs (UGT1A1, UGT1A3, UGT1A4, UGT1A5, UGT1A6, UGT1A9, UGT2B4, UGT2B7, UGT2B10, UGT2B15, and UGT2B17) and 16 transcription factors (AHR, AR, CAR, ESR2, FXR, GCCR, HNF1a, HNF3a, HNF3b, HNF4a, PPARA, PPARG, PPARGC, PXR, SP1, and STAT3) in liver tissue of donors (n = 38) ranging from 0 to 25 years of age. We also examined the correlation between age and microsomal activities using 14 known UGT drug substrates in the liver samples (n = 19) of children donors. We found a statistically significant increase (nominal p < 0.05) in the expression of UGT1A1, UGT1A3, UGT1A4, UGT1A5, UGT1A6, UGT2B7, and UGT2B17, as well as glucuronidation activities of serotonin, testosterone, and vorinostat during the first 25 years of life. Expression of estrogen receptor 1 and pregnane X receptor, two strong UGT transcriptional regulators, were significantly correlated with both age and UGT mRNA expression (p ≤ 0.05). These results suggest that both UGT expression and activity increase during childhood and adolescence, possibly driven in part by hormonal signaling. Our findings may help explain inter-patient variability in response to medications among children. PMID:27899892

  18. Dynamics of 5-carboxylcytosine during hepatic differentiation: potential general role for active demethylation by DNA repair in lineage specification.

    PubMed

    Lewis, Lara C; Lo, Peggy Cho Kiu; Foster, Jeremy M; Dai, Nan; Corrêa, Ivan R; Durczak, Paulina M; Duncan, Gary; Ramsawhook, Ashley; Aithal, Guruprasad Padur; Denning, Chris; Hannan, Nicholas R F; Ruzov, Alexey

    2017-03-07

    Patterns of DNA methylation (5-methylcytosine, 5mC) are rearranged during differentiation contributing to the regulation of cell type-specific gene expression. TET proteins oxidize 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Both 5fC and 5caC can be recognized and excised from DNA by thymine-DNA glycosylase (TDG) followed by the subsequent incorporation of unmodified cytosine into the abasic site via the base excision repair (BER) pathway. We previously demonstrated that 5caC accumulates during lineage specification of neural stem cells (NSCs) suggesting that such active demethylation pathway is operative in this system; however, it is still unknown if TDG/BER-dependent demethylation is utilized during other types of cellular differentiation. Here we analyze dynamics of the global levels of 5hmC and 5caC during differentiation of human pluripotent stem cells towards hepatic endoderm. We show that, similar to differentiating NSCs, 5caC transiently accumulates during hepatic differentiation. The levels of 5caC increase during specification of foregut, peak at the stage of hepatic endoderm commitment, and drop in differentiating cells concurrently with the onset of expression of alpha fetoprotein, a marker of committed hepatic progenitors. Moreover, we show that 5caC accumulates at promoter regions of several genes expressed during hepatic specification at differentiation stages corresponding to the beginning of their expression. Our data indicate that transient 5caC accumulation is a common feature of two different types (neural/glial and endoderm/hepatic) of cellular differentiation. This suggests that oxidation of 5mC may represent a general mechanism of rearrangement of 5mC profiles during lineage specification of somatic cells in mammals.

  19. JMJD3 aids in reprogramming of bone marrow progenitor cells to hepatic phenotype through epigenetic activation of hepatic transcription factors

    PubMed Central

    Kochat, Veena; Equbal, Zaffar; Baligar, Prakash; Kumar, Vikash; Srivastava, Madhulika; Mukhopadhyay, Asok

    2017-01-01

    The strictly regulated unidirectional differentiation program in some somatic stem/progenitor cells has been found to be modified in the ectopic site (tissue) undergoing regeneration. In these cases, the lineage barrier is crossed by either heterotypic cell fusion or direct differentiation. Though studies have shown the role of coordinated genetic and epigenetic mechanisms in cellular development and differentiation, how the lineage fate of adult bone marrow progenitor cells (BMPCs) is reprogrammed during liver regeneration and whether this lineage switch is stably maintained are not clearly understood. In the present study, we wanted to decipher genetic and epigenetic mechanisms that involve in lineage reprogramming of BMPCs into hepatocyte-like cells. Here we report dynamic transcriptional change during cellular reprogramming of BMPCs to hepatocytes and dissect the epigenetic switch mechanism of BM cell-mediated liver regeneration after acute injury. Genome-wide gene expression analysis in BM-derived hepatocytes, isolated after 1 month and 5 months of transplantation, showed induction of hepatic transcriptional program and diminishing of donor signatures over the time. The transcriptional reprogramming of BM-derived cells was found to be the result of enrichment of activating marks (H3K4me3 and H3K9Ac) and loss of repressive marks (H3K27me3 and H3K9me3) at the promoters of hepatic transcription factors (HTFs). Further analyses showed that BMPCs possess bivalent histone marks (H3K4me3 and H3K27me3) at the promoters of crucial HTFs. H3K27 methylation dynamics at the HTFs was antagonistically regulated by EZH2 and JMJD3. Preliminary evidence suggests a role of JMJD3 in removal of H3K27me3 mark from promoters of HTFs, thus activating epigenetically poised hepatic genes in BMPCs prior to partial nuclear reprogramming. The importance of JMJD3 in reprogramming of BMPCs to hepatic phenotype was confirmed by inhibiting catalytic function of the enzyme using small molecule

  20. Antioxidant Activity of Oat Proteins Derived Peptides in Stressed Hepatic HepG2 Cells

    PubMed Central

    Du, Yichen; Esfandi, Ramak; Willmore, William G.; Tsopmo, Apollinaire

    2016-01-01

    The purpose of this study was to determine, for the first time, antioxidant activities of seven peptides (P1–P7) derived from hydrolysis of oat proteins in a cellular model. In the oxygen radical absorbance capacity (ORAC) assay, it was found that P2 had the highest radical scavenging activity (0.67 ± 0.02 µM Trolox equivalent (TE)/µM peptide) followed by P5, P3, P6, P4, P1, and P7 whose activities were between 0.14–0.61 µM TE/µM). In the hepatic HepG2 cells, none of the peptides was cytotoxic at 20–300 µM. In addition to having the highest ORAC value, P2 was also the most protective (29% increase in cell viability) against 2,2′-azobis(2-methylpropionamidine) dihydrochloride -induced oxidative stress. P1, P6, and P7 protected at a lesser extent, with an 8%–21% increase viability of cells. The protection of cells was attributed to several factors including reduced production of intracellular reactive oxygen species, increased cellular glutathione, and increased activities of three main endogenous antioxidant enzymes. PMID:27775607

  1. Increased infiltration of macrophages in omental adipose tissue is associated with marked hepatic lesions in morbid human obesity.

    PubMed

    Cancello, Raffaella; Tordjman, Joan; Poitou, Christine; Guilhem, Gaël; Bouillot, Jean Luc; Hugol, Danielle; Coussieu, Christiane; Basdevant, Arnaud; Bar Hen, Avner; Bedossa, Pierre; Guerre-Millo, Michèle; Clément, Karine

    2006-06-01

    In human obesity, white adipose tissue (WAT) is enriched in macrophages. How macrophage infiltration in WAT contributes to the complications of obesity is unknown. This study tested the hypothesis that recruitment of macrophages in omental WAT is associated with hepatic damage in obese patients. Paired biopsies of subcutaneous and omental WAT and a liver biopsy were collected during gastric surgery in 46 obese women and 9 obese men (BMI 47.9 +/- 0.93 kg/m(2)). The number of HAM56+ macrophages in WAT was quantified microscopically, and correlations with clinical and biological parameters and histological liver pathology were investigated. There were twice as many macrophages in omental as in subcutaneous WAT (P<0.0001). After adjustment for age, omental WAT macrophage infiltration was correlated to fasting glucose and insulin, quantitative insulin sensitivity check index, triglycerides, aspartate aminotransferase (AST), and gamma-glutamyltranspeptidase. We propose an easy equation to estimate the amount of macrophages in omental WAT. Increased macrophage accumulation specifically in omental WAT was associated with hepatic fibroinflammatory lesions (P=0.01). The best predictive model for the severity of hepatic damage includes adiponectinemia, AST, and omental WAT macrophages. These data suggest that the presence of macrophages in omental WAT participates in the cellular mechanisms favoring hepatic fibroinflammatory lesions in obese patients.

  2. MicroRNA-34a Promotes Hepatic Stellate Cell Activation via Targeting ACSL1

    PubMed Central

    Yan, Gangli; Li, Binbin; Xin, Xuan; Xu, Midie; Ji, Guoqing; Yu, Hongyu

    2015-01-01

    Background The incidence of liver fibrosis remains high due to the lack of effective therapies. Our previous work found that microRNA (miR)-34a expression was increased, while acy1-CoA synthetase long-chain family member1 (ACSL1) was decreased, in a dimethylnitrosamine (DNS)-induced hepatic fibrosis rat model. We hypothesized that miR-34a may play a role in the process of hepatic fibrosis by targeting ACSL1. Material/Methods From days 2 to 14, cultured primary hepatic stellate cells (HSCs) underwent cell morphology, immunocytochemical staining, and quantitative reverse transcription PCR (RT-qPCR) for alpha smooth muscle actin (α-SMA), desmin, rno-miR-34a, and ACSL1 expression. Wild-type and mutant luciferase reporter plasmids were constructed according to the predicted miR-34a binding site on the 3′-untranslated region (UTR) of the ACSL1 mRNA and then transfected into HEK293 cells. rno-miR-34a was silenced in HSCs to confirm that rno-miR-34a negatively regulates ACSL1 expression. mRNA and protein expression of α-SMA, type I collagen, and desmin were assayed in miR-34a-silenced HSCs. Results HSCs were deemed quiescent during the first 3 days and activated after 10 days. rno-miR-34a expression increased, and ACSL1 expression decreased, from day 2 to 7 to 14. rno-miR-34a was shown to specifically bind to the 3′-UTR of ACSL1. miR-34a-silenced HSCs showed higher ACSL1and lower α-SMA, type I collagen, and desmin expression than that of matching negative controls and non-transfected cells. Conclusions miR-34a appears to play an important role in the process of liver fibrosis by targeting ACSL1 and may show promise as a therapeutic molecular target for hepatic fibrosis. PMID:26437572

  3. Activity-based profiling of the proteasome pathway during hepatitis C virus infection.

    PubMed

    Nasheri, Neda; Ning, Zhibin; Figeys, Daniel; Yao, Shao; Goto, Natalie K; Pezacki, John Paul

    2015-11-01

    Hepatitis C virus (HCV) infection often leads to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. The stability of the HCV proteins is controlled by ubiquitin-dependent and ubiquitin-independent proteasome pathways. Many viruses modulate proteasome function for their propagation. To examine the interrelationship between HCV and the proteasome pathways we employed a quantitative activity-based protein profiling method. Using this approach we were able to quantify the changes in the activity of several proteasome subunits and found that proteasome activity is drastically reduced by HCV replication. The results imply a link between the direct downregulation of the activity of this pathway and chronic HCV infection.

  4. EZH2-mediated repression of Dkk1 promotes hepatic stellate cell activation and hepatic fibrosis.

    PubMed

    Yang, Yang; Chen, Xiao-Xia; Li, Wan-Xia; Wu, Xiao-Qin; Huang, Cheng; Xie, Juan; Zhao, Yu-Xin; Meng, Xiao-Ming; Li, Jun

    2017-03-23

    EZH2, a histone H3 lysine-27-specific methyltransferase, is involved in diverse physiological and pathological processes including cell proliferation and differentiation. However, the role of EZH2 in liver fibrosis is largely unknown. In this study, it was identified that EZH2 promoted Wnt pathway-stimulated fibroblasts in vitro and in vivo by repressing Dkk-1, which is a Wnt pathway antagonist. The expression of EZH2 was increased in CCl4 -induced rat liver and primary HSCs as well as TGF-β1-treated HSC-T6, whereas the expression of Dkk1 was reduced. Silencing of EZH2 prevented TGF-β1-induced proliferation of HSC-T6 cells and the expression of α-SMA. In addition, knockdown of Dkk1 promoted TGF-β1-induced activation of HSCs. Moreover, silencing of EZH2 could restore the repression of Dkk-1 through trimethylation of H3K27me3 in TGF-β1-treated HSC-T6 cells. Interestingly, inhibition of EZH2 had almost no effect on the activation of HSC when Dkk1 was silenced. Collectively, EZH2-mediated repression of Dkk1 promotes the activation of Wnt/β-catenin pathway, which is an essential event for HSC activation.

  5. Hepatic falciform ligament Tc-99m-macroaggregated albumin activity on SPECT/CT prior to Yttrium-90 microsphere radioembolization: prophylactic measures to prevent non-target microsphere localization via patent hepatic falciform arteries.

    PubMed

    Kao, Yung Hsiang; Tan, Andrew E H; Khoo, Li Ser; Lo, Richard H G; Chow, Pierce K H; Goh, Anthony S W

    2011-06-01

    Yttrium-90 (Y-90) selective internal radiation therapy (SIRT) is increasingly used to treat inoperable hepatocellular carcinoma. We describe two patients where hepatic falciform ligament Technetium-99m-macroaggregated albumin (Tc-99m-MAA) activity was identified on single photon emission computed tomography with integrated low-dose CT (SPECT/CT) scan during pre-therapy planning, and the steps taken to prevent radiation dermatitis. The first patient underwent prophylactic coil embolization of the patent hepatic falciform artery; the second patient underwent super-selective infusion of Y-90 resin microspheres to avoid the patent hepatic falciform artery. The incidence of falciform ligament Tc-99m-MAA activity detected on SPECT/CT at our institution is 10%. Tc-99m-MAA SPECT/CT scan provides valuable diagnostic information for treatment planning prior to Y-90 SIRT.

  6. Aerobic exercise increases peripheral and hepatic insulin sensitivity in sedentary adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Data are limited on the effects of controlled aerobic exercise programs (without weight loss) on insulin sensitivity and glucose metabolism in children and adolescents. To determine whether a controlled aerobic exercise program (without weight loss) improves peripheral and hepatic insulin sensitivi...

  7. The association of phosphoinositide 3-kinase enhancer A with hepatic insulin receptor enhances its kinase activity.

    PubMed

    Chan, Chi Bun; Liu, Xia; He, Kunyan; Qi, Qi; Jung, Dae Y; Kim, Jason K; Ye, Keqiang

    2011-07-01

    Dysfunction of hepatic insulin receptor tyrosine kinase (IRTK) causes the development of type 2 diabetes. However, the molecular mechanism regulating IRTK activity in the liver remains poorly understood. Here, we show that phosphoinositide 3-kinase enhancer A (PIKE-A) is a new insulin-dependent enhancer of hepatic IRTK. Liver-specific Pike-knockout (LPKO) mice display glucose intolerance with impaired hepatic insulin sensitivity. Specifically, insulin-provoked phosphoinositide 3-kinase/Akt signalling is diminished in the liver of LPKO mice, leading to the failure of insulin-suppressed gluconeogenesis and hyperglycaemia. Thus, hepatic PIKE-A has a key role in mediating insulin signal transduction and regulating glucose homeostasis in the liver.

  8. Hepatitis B virus X protein mutants exhibit distinct biological activities in hepatoma Huh7 cells

    SciTech Connect

    Liu Xiaohong; Zhang Shuhui; Lin Jing; Zhang Shunmin; Feitelson, Mark A.; Gao Hengjun; Zhu Minghua

    2008-09-05

    The role of the hepatitis B virus X protein (HBx) in hepatocarcinogenesis remains controversial. To investigate the biological impact of hepatitis B virus x gene (HBx) mutation on hepatoma cells, plasmids expressing the full-length HBx or HBx deletion mutants were constructed. The biological activities in these transfectants were analyzed by a series of assays. Results showed that HBx3'-20 and HBx3'-40 amino acid deletion mutants exhibited an increase in cellular proliferation, focus formation, tumorigenicity, and invasive growth and metastasis through promotion of the cell cycle from G0/G1 to the S phase, when compared with the full-length HBx. In contrast, HBx3'-30 amino acid deletion mutant repressed cell proliferation by blocking in G1 phase. The expression of P53, p21{sup WAF1}, p14{sup ARF}, and MDM2 proteins was regulated by expression of HBx mutants. In conclusions, HBx variants showed different effects and functions on cell proliferation and invasion by regulation of the cell cycle progression and its associated proteins expression.

  9. The metabolic activator FOXO1 binds hepatitis B virus DNA and activates its transcription

    SciTech Connect

    Shlomai, Amir; Shaul, Yosef

    2009-04-17

    Hepatitis B virus (HBV) is a small DNA virus that targets the liver and infects humans worldwide. Recently we have shown that the metabolic regulator PGC-1{alpha} coactivates HBV transcription thereby rendering the virus susceptible to fluctuations in the nutritional status of the liver. PGC-1{alpha} coactivation of HBV is mediated through the liver-enriched nuclear receptor HNF4{alpha} and through another yet unknown transcription factor(s). Here we show that the forkhead transcription factor FOXO1, a known target for PGC-1{alpha} coactivation and a central mediator of glucose metabolism in the liver, binds HBV core promoter and activates its transcription. This activation is further enhanced in the presence of PGC-1{alpha}, implying that FOXO1 is a target for PGC-1{alpha} coactivation of HBV transcription. Thus, our results identify another key metabolic regulator as an activator of HBV transcription, thereby supporting the principle that HBV gene expression is regulated in a similar way to key hepatic metabolic genes.

  10. High T3, Low T4 Serum Levels in Mct8 Deficiency Are Not Caused by Increased Hepatic Conversion through Type I Deiodinase

    PubMed Central

    Wirth, Eva K.; Rijntjes, Eddy; Meyer, Franziska; Köhrle, Josef; Schweizer, Ulrich

    2015-01-01

    Background The Allan-Herndon-Dudley syndrome is a severe psychomotor retardation accompanied by specific changes in circulating thyroid hormone levels (high T3, low T4). These are caused by mutations in the thyroid hormone transmembrane transport protein monocarboxylate transporter 8 (MCT8). Objective: To test the hypothesis that circulating low T4 and high T3 levels are caused by enhanced conversion of T4 via increased activity of hepatic type I deiodinase (Dio1). Methods We crossed mice deficient in Mct8 with mice lacking Dio1 activity in hepatocytes. Translation of the selenoenzyme Dio1 was abrogated by hepatocyte-specific inactivation of selenoprotein biosynthesis. Results Inactivation of Dio1 activity in the livers of global Mct8-deficient mice does not restore normal circulating thyroid hormone levels. Conclusions Our data suggest that although hepatic Dio1 activity is increased in Mct8-deficient mice, it does not cause the observed abnormal circulating thyroid hormone levels. Since global inactivation of Dio1 in Mct8-deficient mice does normalize circulating thyroid hormone levels, the underlying mechanism and relevant tissues involved remain to be elucidated. PMID:26601078

  11. Neferine inhibits cultured hepatic stellate cell activation and facilitates apoptosis: A possible molecular mechanism.

    PubMed

    Ding, Hui; Shi, Jinghong; Wang, Ying; Guo, Jia; Zhao, Juhui; Dong, Lei

    2011-01-10

    Neferine is a major alkaloid component of "Lian Zi Xin", embryos of the seeds of Nelumbo nucifera Gaertner, Nymphaeaceae. Previous studies have shown that neferine has an inhibitory effect on pulmonary fibrosis through its anti-inflammatory and anti-oxidative activities and inhibition of cytokines and NF-κB. However, it is unknown whether neferine also has an inhibitory effect on liver fibrosis through inhibition of TGF-β1 and collagen I and facilitation of apoptosis of hepatic stellate cells. This study examined the effects of neferine on cultured hepatic stellate (HSC-T6) cells and explored its possible action mechanisms by means of MTT assay, enzyme-linked immunosorbent assay, flow-cytometric annexin V-PI assay and Hoechst 33258 staining, as well as real-time PCR and western blotting. The results showed that neferine administration (2, 4, 6, 8 and 10μmol/l) significantly decreased the TGF-β1 and collagen I produced in HSC-T6 cells, and increased the HSC-T6 cell apoptosis in a dose-dependent manner. Neferine treatment for 48h at concentrations of 6 and 10μmol/l significantly increased Bax and caspase 3 mRNAs and proteins, and reduced Bcl2 and alpha-smooth muscle actin (α-SMA) mRNAs and proteins. Our data indicate that neferine efficiently inhibits cultured HSC-T6 cell activation and induces apoptosis by increasing Bax and caspase 3 expression via the mitochondrial pathway.

  12. Experimental nonalcoholic steatohepatitis increases exposure to simvastatin hydroxy acid by decreasing hepatic organic anion transporting polypeptide expression.

    PubMed

    Clarke, John D; Hardwick, Rhiannon N; Lake, April D; Canet, Mark J; Cherrington, Nathan J

    2014-03-01

    Simvastatin (SIM)-induced myopathy is a dose-dependent adverse drug reaction (ADR) that has been reported to occur in 18.2% of patients receiving a 40- to 80-mg dose. The pharmacokinetics of SIM hydroxy acid (SIMA), the bioactive form of SIM, and the occurrence of SIM-induced myopathy are linked to the function of the organic anion transporting polypeptide (Oatp) hepatic uptake transporters. Genetic polymorphisms in SLCO1B1, the gene for human hepatic OATP1B1, cause decreased elimination of SIMA and increased risk of developing myopathy. Nonalcoholic steatohepatitis (NASH) is the most severe form of nonalcoholic fatty liver disease, and is known to alter drug transporter expression and drug disposition. The purpose of this study was to assess the metabolism and disposition of SIM in a diet-induced rodent model of NASH. Rats were fed a methionine- and choline-deficient diet for 8 weeks to induce NASH and SIM was administered intravenously. Diet-induced NASH caused increased plasma retention and decreased biliary excretion of SIMA due to decreased protein expression of multiple hepatic Oatps. SIM exhibited increased volume of distribution in NASH as evidenced by increased muscle, decreased plasma, and no change in biliary concentrations. Although Cyp3a and Cyp2c11 proteins were decreased in NASH, no alterations in SIM metabolism were observed. These data, in conjunction with our previous data showing that human NASH causes a coordinated downregulation of hepatic uptake transporters, suggest that NASH-mediated transporter regulation may play a role in altered SIMA disposition and the occurrence of myopathy.

  13. Mouse Hepatitis Virus Infection Induces a Toll-Like Receptor 2-Dependent Activation of Inflammatory Functions in Liver Sinusoidal Endothelial Cells during Acute Hepatitis

    PubMed Central

    Bleau, Christian; Filliol, Aveline; Samson, Michel

    2016-01-01

    ABSTRACT Under physiological conditions, the liver sinusoidal endothelial cells (LSECs) mediate hepatic immune tolerance toward self or foreign antigens through constitutive expression of anti-inflammatory mediators. However, upon viral infection or Toll-like receptor 2 (TLR2) activation, LSECs can achieve proinflammatory functions, but their role in hepatic inflammation during acute viral hepatitis is unknown. Using the highly virulent mouse hepatitis virus type 3 (MHV3) and the attenuated variants 51.6-MHV3 and YAC-MHV3, exhibiting lower tropism for LSECs, we investigated in vivo and in vitro the consequence of LSEC infection on their proinflammatory profiles and the aggravation of acute hepatitis process. In vivo infection with virulent MHV3, in comparison to attenuated strains, resulted in fulminant hepatitis associated with higher hepatic viral load, tissue necrosis, and levels of inflammatory mediators and earlier recruitment of inflammatory cells. Such hepatic inflammatory disorders correlated with disturbed production of interleukin-10 (IL-10) and vascular factors by LSECs. We next showed in vitro that infection of LSECs by the virulent MHV3 strain altered their production of anti-inflammatory cytokines and promoted higher release of proinflammatory and procoagulant factors and earlier cell damage than infection by attenuated strains. This higher replication and proinflammatory activation in LSECs by the virulent MHV3 strain was associated with a specific activation of TLR2 signaling by the virus. We provide evidence that TLR2 activation of LSCEs by MHV3 is an aggravating factor of hepatic inflammation and correlates with the severity of hepatitis. Taken together, these results indicate that preservation of the immunotolerant properties of LSECs during acute viral hepatitis is imperative in order to limit hepatic inflammation and damage. IMPORTANCE Viral hepatitis B and C infections are serious health problems affecting over 350 million and 170 million

  14. Aging increases the susceptibility of hepatic inflammation, liver fibrosis and aging in response to high-fat diet in mice.

    PubMed

    Kim, In Hee; Xu, Jun; Liu, Xiao; Koyama, Yukinori; Ma, Hsiao-Yen; Diggle, Karin; You, Young-Hyun; Schilling, Jan M; Jeste, Dilip; Sharma, Kumar; Brenner, David A; Kisseleva, Tatiana

    2016-08-01

    We aimed to investigate whether aging increases the susceptibility of hepatic and renal inflammation or fibrosis in response to high-fat diet (HFD) and explore the underlying genetic alterations. Middle (10 months old) and old (20 months old) aged, male C57BL/6N mice were fed either a low-fat diet (4 % fat) or HFD (60 % fat) for 4 months. Young (3 months old) aged mice were included as control group. HFD-induced liver and kidney injuries were analyzed by serum and urine assay, histologic staining, immunohistochemistry, and reverse-transcription real-time quantitative polymerase chain reaction. Total RNA sequencing with next-generation technology was done with RNA extracted from liver tissues. With HFD feeding, aged was associated with higher serum alanine aminotransferase levels, marked infiltration of hepatic macrophages, and increased expression of inflammatory cytokines (MCP1, TNF-α, IL-1β, IL-6, IL-12, IL-17A). Importantly, aged mice showed more advanced hepatic fibrosis and increased expression of fibrogenic markers (Col-I-α1, αSMA, TGF-β1, TGF-β2, TGFβRII, PDGF, PDGFRβII, TIMP1) in response to HFD. Aged mice fed on HFD also showed increased oxidative stress and TLR4 expression. In the total RNA seq and gene ontology analysis of liver, old-aged HFD group showed significant up-regulation of genes linked to innate immune response, immune response, defense response, inflammatory response compared to middle-aged HFD group. Meanwhile, aging and HFD feeding showed significant increase in glomerular size and mesangial area, higher urine albumin/creatinine ratio, and advanced renal inflammation or fibrosis. However, the difference of HFD-induced renal injury between old-aged group and middle-aged group was not significant. The susceptibility of hepatic fibrosis as well as hepatic inflammation in response to HFD was significantly increased with aging. In addition, aging was associated with glomerular alterations and increased renal inflammation or

  15. High fat diet-induced changes of mouse hepatic transcription and enhancer activity can be reversed by subsequent weight loss.

    PubMed

    Siersbæk, Majken; Varticovski, Lyuba; Yang, Shutong; Baek, Songjoon; Nielsen, Ronni; Mandrup, Susanne; Hager, Gordon L; Chung, Jay H; Grøntved, Lars

    2017-01-10

    Epigenetic factors have been suggested to play an important role in metabolic memory by trapping and maintaining initial metabolic changes within the transcriptional regulatory machinery. In this study we fed mice a high fat diet (HFD) for seven weeks followed by additional five weeks of chow, to identify HFD-mediated changes to the hepatic transcriptional program that may persist after weight loss. Mice fed a HFD displayed increased fasting insulin levels, hepatosteatosis and major changes in hepatic gene transcription associated with modulation of H3K27Ac at enhancers, but no significant changes in chromatin accessibility, indicating that HFD-regulated gene transcription is primarily controlled by modulating the activity of pre-established enhancers. After return to the same body weight as chow fed control mice, the fasting insulin, glucose, and hepatic triglyceride levels were fully restored to normal levels. Moreover, HFD-regulated H3K27Ac and mRNA levels returned to similar levels as control mice. These data demonstrates that the transcription regulatory landscape in the liver induced by HFD is highly dynamic and can be reversed by weight loss. This provides hope for efficient treatment of early obesity-associated changes to hepatic complications by simple weight loss intervention without persistent reprograming of the liver transcriptome.

  16. High fat diet-induced changes of mouse hepatic transcription and enhancer activity can be reversed by subsequent weight loss

    PubMed Central

    Siersbæk, Majken; Varticovski, Lyuba; Yang, Shutong; Baek, Songjoon; Nielsen, Ronni; Mandrup, Susanne; Hager, Gordon L.; Chung, Jay H.; Grøntved, Lars

    2017-01-01

    Epigenetic factors have been suggested to play an important role in metabolic memory by trapping and maintaining initial metabolic changes within the transcriptional regulatory machinery. In this study we fed mice a high fat diet (HFD) for seven weeks followed by additional five weeks of chow, to identify HFD-mediated changes to the hepatic transcriptional program that may persist after weight loss. Mice fed a HFD displayed increased fasting insulin levels, hepatosteatosis and major changes in hepatic gene transcription associated with modulation of H3K27Ac at enhancers, but no significant changes in chromatin accessibility, indicating that HFD-regulated gene transcription is primarily controlled by modulating the activity of pre-established enhancers. After return to the same body weight as chow fed control mice, the fasting insulin, glucose, and hepatic triglyceride levels were fully restored to normal levels. Moreover, HFD-regulated H3K27Ac and mRNA levels returned to similar levels as control mice. These data demonstrates that the transcription regulatory landscape in the liver induced by HFD is highly dynamic and can be reversed by weight loss. This provides hope for efficient treatment of early obesity-associated changes to hepatic complications by simple weight loss intervention without persistent reprograming of the liver transcriptome. PMID:28071704

  17. Phosphorylated heat shock protein 27 promotes lipid clearance in hepatic cells through interacting with STAT3 and activating autophagy.

    PubMed

    Shen, Lei; Qi, Zhilin; Zhu, Yanyan; Song, Xiaomeng; Xuan, Chunxia; Ben, Peiling; Lan, Lei; Luo, Lan; Yin, Zhimin

    2016-08-01

    Nonalcoholic fatty liver disease (NAFLD) has become the major liver disease worldwide. Recently, several studies have identified that the activation of autophagy attenuates hepatic steatosis. Heat shock protein 27 (Hsp27) is involved in autophagy in response to various stimuli. In this study, we demonstrate that phosphorylated Hsp27 stimulates autophagy and lipid droplet clearance and interacts with STAT3. In vivo study showed that high fat diet (HFD) feeding increased Hsp25 (mouse orthology of Hsp27) phosphorylation and autophagy in mouse livers. Inhibition of Hsp25 phosphorylation exacerbated HFD-induced hepatic steatosis in mice. In vitro study showed that palmitate-induced lipid overload in hepatic cells was enhanced by Hsp27 knockdown, KRIBB3 treatment and Hsp27-3A (non-phosphorylatable) overexpression but was prevented by Hsp27-WT (wild type) and Hsp27-3D (phosphomimetic) overexpression. Mechanism analysis demonstrated that palmitate could induce Hsp27 phosphorylation which promoted palmitate-induced autophagy. Phosphorylated Hsp27 interacted with STAT3 in response to palmitate treatment, and disrupted the STAT3/PKR complexes, facilitated PKR-dependent eIF2α phosphorylation, and thus stimulated autophagy. To conclude, our study provides a novel mechanism by which the phosphorylated Hsp27 promotes hepatic lipid clearance and suggests a new insight for therapy of steatotic diseases such as nonalcoholic fatty liver disease (NAFLD).

  18. Update on Alcoholic Hepatitis.

    PubMed

    Torok, Natalie J

    2015-11-02

    Alcoholic liver disease is one of the most prevalent liver diseases worldwide, and a major cause of morbidity and mortality. Alcoholic hepatitis is a severe form of liver injury in patients with alcohol abuse, can present as an acute on chronic liver failure associated with a rapid decline in liver synthetic function, and consequent increase in mortality. Despite therapy, about 30%-50% of patients with severe alcoholic hepatitis eventually die. The pathogenic pathways that lead to the development of alcoholic hepatitis are complex and involve oxidative stress, gut dysbiosis, and dysregulation of the innate and adaptive immune system with injury to the parenchymal cells and activation of hepatic stellate cells. As accepted treatment approaches are currently limited, a better understanding of the pathophysiology would be required to generate new approaches that improve outcomes. This review focuses on recent advances in the diagnosis, pathogenesis of alcoholic hepatitis and novel treatment strategies.

  19. Viral Hepatitis the US Military: A Study of Hospitalization Records from 1974 to 1999

    DTIC Science & Technology

    2000-01-01

    hepatitis and non- 571.41 Chronic persistent hepatitis alcohol -related cirrhosis increased from 1989 until 1995 but 571.49 Other chronic hepatitis then...hepatitis and three cases of alcohol cirrhosis among actively serving military personnel. For this study, annual rates of hospitalization were...HOSPITALIZATION FOR the hepatitis A vaccine, also may have influenced hospitaliza- CHRONIC HEPATITIS AND NON- ALCOHOL -RELATED CIRRHOSIS IN tion rates. Currently

  20. Hepatic overexpression of a constitutively active form of liver glycogen synthase improves glucose homeostasis.

    PubMed

    Ros, Susana; Zafra, Delia; Valles-Ortega, Jordi; García-Rocha, Mar; Forrow, Stephen; Domínguez, Jorge; Calbó, Joaquim; Guinovart, Joan J

    2010-11-26

    In this study, we tested the efficacy of increasing liver glycogen synthase to improve blood glucose homeostasis. The overexpression of wild-type liver glycogen synthase in rats had no effect on blood glucose homeostasis in either the fed or the fasted state. In contrast, the expression of a constitutively active mutant form of the enzyme caused a significant lowering of blood glucose in the former but not the latter state. Moreover, it markedly enhanced the clearance of blood glucose when fasted rats were challenged with a glucose load. Hepatic glycogen stores in rats overexpressing the activated mutant form of liver glycogen synthase were enhanced in the fed state and in response to an oral glucose load but showed a net decline during fasting. In order to test whether these effects were maintained during long term activation of liver glycogen synthase, we generated liver-specific transgenic mice expressing the constitutively active LGS form. These mice also showed an enhanced capacity to store glycogen in the fed state and an improved glucose tolerance when challenged with a glucose load. Thus, we conclude that the activation of liver glycogen synthase improves glucose tolerance in the fed state without compromising glycogenolysis in the postabsorptive state. On the basis of these findings, we propose that the activation of liver glycogen synthase may provide a potential strategy for improvement of glucose tolerance in the postprandial state.

  1. Acetylcholinesterase activity in an experimental rat model of Type C hepatic encephalopathy.

    PubMed

    Méndez, Marta; Méndez-López, Magdalena; López, Laudino; Aller, María A; Arias, Jaime; Arias, Jorge L

    2011-05-01

    Patients with liver malfunction often suffer from hepatic encephalopathy, a neurological complication which can affect attention and cognition. Diverse experimental models have been used to study brain alterations that may be responsible for hepatic encephalopathy symptoms. The aim of the study was to determine whether cognitive impairment found in cirrhosis could be due to disturbance of acetylcholinesterase activity. Acetylcholinesterase activity was assessed in the brains of Wistar rats with thioacetamide-induced cirrhosis. The cirrhotic group displayed up-regulation of acetylcholinesterase levels in the entorrhinal cortex, anterodorsal and anteroventral thalamus and accumbens, whereas down-regulation was found in the CA1, CA3 and dentate gyrus of the hippocampus. Our results indicate that the experimental model of hepatic encephalopathy by chronic administration of thioacetamide presents alterations of acetylcholinesterase activity in brain limbic system regions, which play a role in attention and memory.

  2. Autophagy Releases Lipid That Promotes Fibrogenesis by Activated Hepatic Stellate Cells in Mice and in Human Tissues

    PubMed Central

    HERNÁNDEZ–GEA, VIRGINIA; GHIASSI–NEJAD, ZAHRA; ROZENFELD, RAPHAEL; GORDON, RONALD; FIEL, MARIA ISABEL; YUE, ZHENYU; CZAJA, MARK J.; FRIEDMAN, SCOTT L.

    2012-01-01

    BACKGROUND & AIMS The pathogenesis of liver fibrosis involves activation of hepatic stellate cells, which is associated with depletion of intracellular lipid droplets. When hepatocytes undergo autophagy, intracellular lipids are degraded in lysosomes. We investigated whether autophagy also promotes loss of lipids in hepatic stellate cells to provide energy for their activation and extended these findings to other fibrogenic cells. METHODS We analyzed hepatic stellate cells from C57BL/6 wild-type, Atg7F/F, and Atg7F/F-GFAP-Cre mice, as well as the mouse stellate cell line JS1. Fibrosis was induced in mice using CCl4 or thioacetamide (TAA); liver tissues and stellate cells were analyzed. Autophagy was blocked in fibrogenic cells from liver and other tissues using small interfering RNAs against Atg5 or Atg7 and chemical antagonists. Human pulmonary fibroblasts were isolated from samples of lung tissue from patients with idiopathic pulmonary fibrosis or from healthy donors. RESULTS In mice, induction of liver injury with CCl4 or TAA increased levels of autophagy. We also observed features of autophagy in activated stellate cells within injured human liver tissue. Loss of autophagic function in cultured mouse stellate cells and in mice following injury reduced fibrogenesis and matrix accumulation; this effect was partially overcome by providing oleic acid as an energy substrate. Autophagy also regulated expression of fibrogenic genes in embryonic, lung, and renal fibroblasts. CONCLUSIONS Autophagy of activated stellate cells is required for hepatic fibrogenesis in mice. Selective reduction of autophagic activity in fibrogenic cells in liver and other tissues might be used to treat patients with fibrotic diseases. PMID:22240484

  3. Testosterone supplementation improves glucose homeostasis despite increasing hepatic insulin resistance in male mouse model of type 2 diabetes mellitus

    PubMed Central

    Pal, M; Gupta, S

    2016-01-01

    Clinical studies have revealed that testosterone supplementation had a positive effect on glucose homeostasis in type 2 diabetes mellitus (T2DM), but did not address how testosterone supplementation affected insulin responsiveness in the liver, a key glucose homeostatic organ. In this study, we aimed to study the effect of testosterone supplementation on hepatic insulin responsiveness and glucose homeostasis through liver in male high-fat diet-induced T2DM mice. Testosterone treatment to T2DM animals showed reduced hepatic glucose output. Testosterone inhibited the insulin signaling in liver, thus increased insulin resistance. However, testosterone treatment inactivated GSK3α independent of PI3K/AKT pathway and inhibited FOXO1 By interaction of androgen receptor to FOXO1 and downregulated PEPCK, causing repression of gluconeogenic pathway, which is otherwise upregulated in T2DM, resulted in better glucose homeostasis. PMID:27941939

  4. Study of the immunogenicity of hepatitis B surface antigen synthesized in transgenic potato plants with increased biosafety.

    PubMed

    Rukavtsova, Elena B; Rudenko, Natalya V; Puchko, Elena N; Zakharchenko, Natalya S; Buryanov, Yaroslav I

    2015-06-10

    Oral immunogenicity of the hepatitis B surface antigen (HBsAg) synthesized in the tubers of marker-free potato plants has been demonstrated. Experiments were performed in the two groups of outbred NMRI mice. At the beginning of investigations, the mice of experimental group were fed the tubers of transgenic potato synthesizing the HBsAg three times. The mice of control group were fed nontransgenic potato. Intraperitoneal injection of the commercial vaccine against hepatitis B (0.5μg/mouse) was made on day 71 of the experiment. Enzyme-linked immunoassay (ELISA) of the serum of immunized animals showed an increase in the level of HBsAg antibodies significantly above the protective value, which was maintained for 1 year after the immunization. In 1 year, the experimental group of mice underwent additional oral immunization with HBsAg-containing potato tubers. As a result, the level of antibodies against the HBsAg increased and remained at a high protective level for several months. The findings show the possibility of using transgenic plants as a substance for obtaining a safe edible vaccine against hepatitis B.

  5. Exercise Sandals Increase Lower Extremity Electromyographic Activity During Functional Activities

    PubMed Central

    Hirth, Christopher J.; Guskiewicz, Kevin M.

    2003-01-01

    Objective: Anecdotal evidence suggests that use of Exercise Sandals results in a number of positive clinical outcomes. However, little research has been conducted to determine their efficacy objectively. Our purposes were to determine the effect of Exercise Sandals on lower leg electromyography (EMG) during activities in the Exercise Sandals and to compare EMG associated with Exercise Sandals with traditional lower extremity rehabilitation exercises. Design and Setting: Two within-subjects, repeated-measures designs were used to identify differences in lower extremity EMG: (1) between activities with and without Exercise Sandals and (2) between Exercise Sandals activities and traditional rehabilitation activities. All data were collected in the Sports Medicine Research Laboratory. Subjects: Eighteen subjects involved in rehabilitation using Exercise Sandals for at least 2 weeks within the year before data collection. Measurements: Mean EMG amplitudes from the tibialis anterior, peroneus longus, soleus, and lateral gastrocnemius muscles were measured during single-leg stance, side stepping, and “high knees,” all performed with and without the Exercise Sandals, as well as single-leg stance on a foam surface and T-band kicks in the sagittal and frontal planes. Results: Exercise Sandals increased lower leg EMG activity, particularly in the ankle invertors and evertors. Also, activities involving the Exercise Sandals resulted in EMG activity similar to or exceeding that associated with traditional ankle-rehabilitation exercises. Conclusions: These results, coupled with the fact that Exercise Sandals are used in a functional closed kinetic chain manner, suggest that they are an effective means of increasing lower extremity muscle activity. PMID:14608427

  6. Distribution of Hepatitis B Virus Genotypes among Patients with Chronic Infection in Japan Shifting toward an Increase of Genotype A▿

    PubMed Central

    Matsuura, Kentaro; Tanaka, Yasuhito; Hige, Shuhei; Yamada, Gotaro; Murawaki, Yoshikazu; Komatsu, Masafumi; Kuramitsu, Tomoyuki; Kawata, Sumio; Tanaka, Eiji; Izumi, Namiki; Okuse, Chiaki; Kakumu, Shinichi; Okanoue, Takeshi; Hino, Keisuke; Hiasa, Yoichi; Sata, Michio; Maeshiro, Tatsuji; Sugauchi, Fuminaka; Nojiri, Shunsuke; Joh, Takashi; Miyakawa, Yuzo; Mizokami, Masashi

    2009-01-01

    Acute hepatitis B virus (HBV) infection has been increasing through promiscuous sexual contacts, and HBV genotype A (HBV/A) is frequent in patients with acute hepatitis B (AHB) in Japan. To compare the geographic distribution of HBV genotypes in patients with chronic hepatitis B (CHB) in Japan between 2005 and 2006 and between 2000 and 2001, with special attention to changes in the proportion of HBV/A, a cohort study was performed to survey changes in genotypes of CHB patients at 16 hospitals throughout Japan. Furthermore, we investigated the clinical characteristics of each genotype and examined the genomic characteristics of HBV/A isolates by molecular evolutionary analyses. Of the 1,271 patients, 3.5%, 14.1%, and 82.3% were infected with HBV/A, -B, and -C, respectively. In comparison with our previous survey during 2000 and 2001, HBV/A was twice as frequent (3.5% versus 1.7%; P = 0.02). The mean age was lower in the patients with HBV/A than in those with HBV/B or -C. Based on phylogenetic analyses of 11 full-length genomes and 29 pre-S2/S region sequences from patients, HBV/A isolates were imported from Europe and the United States, as well as the Philippines and India. They clustered with HBV/A from AHB patients and have spread throughout Japan. HBV/A has been increasing in CHB patients in Japan as a consequence of AHB spreading in the younger generation through promiscuous sexual contacts, aided by a tendency of HBV/A to induce chronic hepatitis. The spread of HBV/A infection in Japan should be prevented by universal vaccination programs. PMID:19297602

  7. Increased hepatic expression of miRNA-122 in patients infected with HCV genotype 3.

    PubMed

    Oliveira, Ketti G; Malta, Fernanda M; Nastri, Ana C S S; Widman, Azzo; Faria, Paola L; Santana, Rúbia A F; Alves, Venâncio A F; Carrilho, Flair J; Pinho, João R R

    2016-04-01

    Hepatitis C virus (HCV) infection affects approximately 3 % of the world population. HCV targets hepatic tissue, and most infected patients develop a chronic infection. Currently, studies have demonstrated an association between HCV-RNA replication and miR-122, the most abundant microRNA in the liver. Our aim was to evaluate liver and serum expression of miR-122 in patients infected with HCV genotypes 1 and 3, and to identify possible associations between miR-122 expression and lipid profiles, HCV viral load, apolipoproteins and liver enzymes. MicroRNAs were isolated from blood and liver tissue, and miR-122 expression was quantified by real-time PCR. HCV viral load was quantified by real-time PCR and HCV genotype, and serum biomarkers were obtained from medical report. The levels of miR-122 were higher in liver than those in blood from individuals infected with HCV genotypes 1 and 3 (p < 0.0001). The tissue levels of miR-122 were higher in subjects infected with HCV genotype 3 (6.22-fold, p < 0.001). A positive correlation was observed between the blood and hepatic levels of miR-122 in patients infected with HCV genotype 1 (r = 0.302, p = 0.026); in these patients, an inverse correlation was observed between serum apolipoprotein A-II (ApoA-II) levels and the blood (r = -0.330; p = 0.014) and hepatic (r = -0.311; p = 0.020) levels of miR-122. In patients infected with HCV genotype 3, there was a positive correlation between the hepatic miR-122 and the high-density lipoprotein-HDL (r = 0.412, p = 0.036) and insulin (r = 0.478, p = 0.044). Lipid metabolism proteins and miR-122 expression levels have different relations in HCV-3- and HCV-1-infected patients.

  8. Suppression of hepatic stellate cell activation by microRNA-29b

    SciTech Connect

    Sekiya, Yumiko; Ogawa, Tomohiro; Yoshizato, Katsutoshi; Ikeda, Kazuo; Kawada, Norifumi

    2011-08-19

    Highlights: {yields} Expression of miR-29b was found to be down-regulated during the activation of hepatic stellate cells in primary culture. {yields} Transfection of a miR-29b precursor markedly attenuated the expression of Col1a1 and Col1a2 mRNAs. {yields} It blunted the increased expression of {alpha}-SMA, DDR2, FN1, ITGB1, and PDGFR-b mRNAs essential for stellate cell activation. {yields} miR-29b overexpression led stellate cells to remain in a quiescent state, as evidenced by their star-like morphology. {yields} miR-29b overexpression suppressed the expression of c-fos mRNA. -- Abstract: MicroRNAs (miRNAs) participate in the regulation of cellular functions including proliferation, apoptosis, and migration. It has been previously shown that the miR-29 family is involved in regulating type I collagen expression by interacting with the 3'UTR of its mRNA. Here, we investigated the roles of miR-29b in the activation of mouse primary-cultured hepatic stellate cells (HSCs), a principal collagen-producing cell in the liver. Expression of miR-29b was found to be down-regulated during HSC activation in primary culture. Transfection of a miR-29b precursor markedly attenuated the expression of Col1a1 and Col1a2 mRNAs and additionally blunted the increased expression of {alpha}-SMA, DDR2, FN1, ITGB1, and PDGFR-{beta}, which are key genes involved in the activation of HSCs. Further, overexpression of miR-29b led HSCs to remain in a quiescent state, as evidenced by their quiescent star-like cell morphology. Although phosphorylation of FAK, ERK, and Akt, and the mRNA expression of c-jun was unaffected, miR-29b overexpression suppressed the expression of c-fos mRNA. These results suggested that miR-29b is involved in the activation of HSCs and could be a candidate molecule for suppressing their activation and consequent liver fibrosis.

  9. Activation of the cAMP-PKA pathway Antagonizes Metformin Suppression of Hepatic Glucose Production.

    PubMed

    He, Ling; Chang, Evan; Peng, Jinghua; An, Hongying; McMillin, Sara M; Radovick, Sally; Stratakis, Constantine A; Wondisford, Fredric E

    2016-05-13

    Metformin is the most commonly prescribed oral anti-diabetic agent worldwide. Surprisingly, about 35% of diabetic patients either lack or have a delayed response to metformin treatment, and many patients become less responsive to metformin over time. It remains unknown how metformin resistance or insensitivity occurs. Recently, we found that therapeutic metformin concentrations suppressed glucose production in primary hepatocytes through AMPK; activation of the cAMP-PKA pathway negatively regulates AMPK activity by phosphorylating AMPKα subunit at Ser-485, which in turn reduces AMPK activity. In this study, we find that metformin failed to suppress glucose production in primary hepatocytes with constitutively activated PKA and did not improve hyperglycemia in mice with hyperglucagonemia. Expression of the AMPKα1(S485A) mutant, which is unable to be phosphorylated by PKA, increased both AMPKα activation and the suppression of glucose production in primary hepatocytes treated with metformin. Intriguingly, salicylate/aspirin prevents the phosphorylation of AMPKα at Ser-485, blocks cAMP-PKA negative regulation of AMPK, and improves metformin resistance. We propose that aspirin/salicylate may augment metformin's hepatic action to suppress glucose production.

  10. Serum hepatic biochemical activity in two populations of workers exposed to styrene

    PubMed Central

    Brodkin, C; Moon, J; Camp, J; Echeverria, D; Redlich, C; Willson, R; Checkoway, H

    2001-01-01

    OBJECTIVE—To determine whether hepatic biochemical changes, as measured by routinely available tests indicative of hepatocellular necrosis, cholestasis, or altered hepatic clearance of bilirubin, occur in association with low to moderate exposure to styrene commonly experienced in industrial production.
METHODS—Two independent cross sectional studies were performed comparing serum hepatic transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), cholestatic enzymes (alkaline phosphatase (AP) and γ glutamyl transpeptidase (GGT)), and bilirubin in (a) 47 workers of fibreglass reinforced plastics who were exposed to styrene and (b) 21 boat and tank fabricators, with separate referent groups of unexposed workers. Exposure to styrene was assessed in air by dosimetry, and in venous blood by headspace analysis. Hepatic biochemical variables were assessed across strata of exposure to styrene defined as 25 ppm in air, or 0.275 mg/l in blood, adjusting for age, sex, body mass index, and ethanol consumption.
RESULTS—A consistent and significant linear trend for increasing direct bilirubin and direct/total bilirubin ratio was found in association with increasing exposure to styrene, by both air and blood monitoring, in both studies. Mean direct bilirubin concentrations increased from 0.05-0.08 mg% in referents to 0.12-0.19 in workers exposed above 25 ppm, with a significant exposure-response trend (p<0.005). Significantly increased direct/total bilirubin ratios, ranging from 0.22 to 0.35 were associated with exposure to styrene (p<0.001), indicating diminished hepatic clearance of conjugated bilirubin. Also, a significant linear association between the hepatic transaminases ALT and AST and exposure to styrene was found in pooled regression analyses, with an increase in AP of about 10 IU/ml in workers exposed above 25 ppm air or 0.275 mg/l blood styrene in pooled analyses from both studies.
CONCLUSIONS—The consistent finding

  11. Involvement of tristetraprolin in transcriptional activation of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase by insulin

    SciTech Connect

    Ness, Gene C.; Edelman, Jeffrey L.; Brooks, Patricia A.

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer siRNAs to tristetraprolin blocks transcription of HMGR in vivo in rat liver. Black-Right-Pointing-Pointer siRNAs to tristetraprolin inhibits insulin activation of HMGR transcription. Black-Right-Pointing-Pointer Insulin acts to rapidly increase tristetraprolin in liver nuclear extracts. -- Abstract: Several AU-rich RNA binding element (ARE) proteins were investigated for their possible effects on transcription of hepatic 3-hydroxy-3-methyglutaryl coenzyme A reductase (HMGR) in normal rats. Using in vivo electroporation, four different siRNAs to each ARE protein were introduced together with HMGR promoter (-325 to +20) luciferase construct and compared to saline controls. All four siRNAs to tristetraprolin (TTP) completely eliminated transcription from the HMGR promoter construct. Since insulin acts to rapidly increase hepatic HMGR transcription, the effect of TTP siRNA on induction by insulin was tested. The 3-fold stimulation by insulin was eliminated by this treatment. In comparison, siRNA to AU RNA binding protein/enoyl coenzyme A hydratase (AUH) had no effect. These findings indicate a role for TTP in the insulin-mediated activation of hepatic HMGR transcription.

  12. Activity and mRNA Levels of Enzymes Involved in Hepatic Fatty Acid Synthesis in Rats Fed Naringenin.

    PubMed

    Hashimoto, Toru; Ide, Takashi

    2015-11-04

    We investigated the physiological activity of naringenin in affecting hepatic lipogenesis and serum and liver lipid levels in rats. Rats were fed diets containing 0, 1, or 2.5 g/kg naringenin for 15 d. Naringenin at a dietary level of 2.5 g/kg significantly decreased the activities and the mRNA levels of various lipogenic enzymes and sterol regulatory element binding protein-1c (SREBP-1c) mRNA level. The activities and the mRNA levels were also 9-22% and 12-38% lower, respectively, in rats fed a 1 g/kg naringenin diet than in the animals fed a naringenin-free diet, although the differences were not significant in many cases. Naringenin at 2.5 g/kg significantly lowered serum triacylglycerol, cholesterol, and phospholipid and hepatic triacylglycerol and cholesterol. This flavonoid at 1.0 g/kg also significantly lowered these parameters except for serum triacylglycerol. Naringenin levels in serum and liver dose-dependently increased, and hepatic concentrations reached levels that can affect various signaling pathways.

  13. Lack of correlation between hepatitis B virus infection and the increasing incidence of primary liver cancer in Sweden.

    PubMed

    Kaczynski, J; Hansson, G; Norkrans, G; Wallerstedt, S

    1991-01-01

    The incidence of primary carcinoma of the liver in Sweden has been reported to increase. In order to study the role of chronic hepatitis B virus (HBV) infection for liver cancer development 40 cases with hepatocellular carcinoma (HCC) were examined for the presence of HBV surface antigen and HBV core antigen in the cancer and in the surrounding non-neoplastic liver tissue. It was not possible to demonstrate a single case with tissue HBV antigen, indicating that HBV plays a minor role in the etiology of HCC in Sweden and thus does not seem to be responsible for the increasing incidence of this cancer.

  14. Nur77 modulates hepatic lipid metabolism through suppression of SREBP1c activity

    SciTech Connect

    Pols, Thijs W.H.; Ottenhoff, Roelof; Vos, Mariska; Levels, Johannes H.M.; Quax, Paul H.A.; Meijers, Joost C.M.; Pannekoek, Hans; Groen, Albert K.; Vries, Carlie J.M. de

    2008-02-22

    NR4A nuclear receptors are induced in the liver upon fasting and regulate hepatic gluconeogenesis. Here, we studied the role of nuclear receptor Nur77 (NR4A1) in hepatic lipid metabolism. We generated mice expressing hepatic Nur77 using adenoviral vectors, and demonstrate that these mice exhibit a modulation of the plasma lipid profile and a reduction in hepatic triglyceride. Expression analysis of >25 key genes involved in lipid metabolism revealed that Nur77 inhibits SREBP1c expression. This results in decreased SREBP1c activity as is illustrated by reduced expression of its target genes stearoyl-coA desaturase-1, mitochondrial glycerol-3-phosphate acyltransferase, fatty acid synthase and the LDL receptor, and provides a mechanism for the physiological changes observed in response to Nur77. Expression of LXR target genes Abcg5 and Abcg8 is reduced by Nur77, and may suggest involvement of LXR in the inhibitory action of Nur77 on SREBP1c expression. Taken together, our study demonstrates that Nur77 modulates hepatic lipid metabolism through suppression of SREBP1c activity.

  15. IRF5 governs liver macrophage activation that promotes hepatic fibrosis in mice and humans

    PubMed Central

    Alzaid, Fawaz; Lagadec, Floriane; Albuquerque, Miguel; Ballaire, Raphaëlle; Orliaguet, Lucie; Hainault, Isabelle; Blugeon, Corinne; Lemoine, Sophie; Lehuen, Agnès; Saliba, David G.; Udalova, Irina A.; Paradis, Valérie; Foufelle, Fabienne

    2016-01-01

    Hepatic fibrosis arises from inflammation in the liver initiated by resident macrophage activation and massive leukocyte accumulation. Hepatic macrophages hold a central position in maintaining homeostasis in the liver and in the pathogenesis of acute and chronic liver injury linked to fibrogenesis. Interferon regulatory factor 5 (IRF5) has recently emerged as an important proinflammatory transcription factor involved in macrophage activation under acute and chronic inflammation. Here, we revealed that IRF5 is significantly induced in liver macrophages from human subjects developing liver fibrosis from nonalcoholic fatty liver disease or hepatitis C virus infection. Furthermore, IRF5 expression positively correlated with clinical markers of liver damage, such as plasma transaminase and bilirubin levels. Interestingly, mice lacking IRF5 in myeloid cells (MKO) were protected from hepatic fibrosis induced by metabolic or toxic stresses. Transcriptional reprogramming of macrophages lacking IRF5 was characterized by immunosuppressive and antiapoptotic properties. Consequently, IRF5 MKO mice respond to hepatocellular stress by promoting hepatocyte survival, leading to complete protection from hepatic fibrogenesis. Our findings reveal a regulatory network, governed by IRF5, that mediates hepatocyte death and liver fibrosis in mice and humans. Therefore, modulating IRF5 function may be an attractive approach to experimental therapeutics in fibroinflammatory liver disease. PMID:27942586

  16. Prevalence of active hepatitis c virus infection in district mansehra pakistan

    PubMed Central

    2010-01-01

    Prevalence of active hepatitis C virus (HCV) infection in apparently healthy inhabitants of District Mansehra, Pakistan was surveyed during September, 2009 to May, 2010. Subjects of different age and gender groups were analyzed through random blood sampling from people of three areas viz; Tehsil Mansehra, Tehsil Balakot and Tehsil Oghi. Sum of 400 individuals, 300 male and 100 females with age groups from 10 years to 50 and above were included in the study. All the individuals were screened for antibodies against HCV. The positive samples thus screened, were subjected to polymerase chain reaction (PCR) analysis for detection of HCV-RNA. The results showed that 3.5% of the people of District Mansehra are actively infected with HCV whereas 7% of the population in general, has the presence of antibodies against HCV in their blood. It was also concluded that the prevalence of active HCV infection was high 4% in males as compared to females (2%). The prevalence of HCV proportionality increases with the increase in age of the people. Its incidence was highest (7.69%) in the people of the age group of 51 years and above, whereas no sign of infection was recorded for the age group of 10-20 years. PMID:21092143

  17. Glucagon-mediated impairments in hepatic and peripheral tissue nutrient disposal are not aggravated by increased lipid availability

    PubMed Central

    Chen, Sheng-Song; Santomango, Tammy S.; Williams, Phillip E.; Lacy, D. Brooks; McGuinness, Owen P.

    2009-01-01

    Glucose, fat, and glucagon availability are increased in diabetes. The normal response of the liver to chronic increases in glucose availability is to adapt to become a marked consumer of glucose. Yet this fails to occur in diabetes. The aim was to determine whether increased glucagon and lipid interact to impair the adaptation to increased glucose availability. Chronically catheterized well controlled depancreatized conscious dogs (n = 21) received 3 days of continuous parenteral nutrition (TPN) that was either high in glucose [C; 75% nonprotein calories (NPC)] or in lipid (HL; 75% NPC) in the presence or absence of a low dose (one-third basal) chronic intraportal infusion of glucagon (GN; 0.25 ng·kg−1·min−1). During the 3 days of TPN, all groups received the same insulin algorithm; the total amount of glucose infused (GIR) was varied to maintain isoglycemia (∼120 mg/dl). On day 3 of TPN, hepatic metabolism was assessed. Glucose and insulin levels were similar in all groups. GIR was decreased in HL and C + GN (∼30%) and was further decreased in HL + GN (55%). Net hepatic glucose uptake was decreased ∼15% in C + GN, and HL and was decreased ∼50% in HL + GN. Lipid alone or combined with glucagon decreased glucose uptake by peripheral tissues. Despite impairing whole body glucose utilization, HL did not limit whole body energy disposal. In contrast, glucagon suppressed whole body energy disposal irrespective of the diet composition. In summary, failure to appropriately suppress glucagon secretion adds to the dietary fat-induced impairment in both hepatic and peripheral glucose disposal. In addition, unlike increasing the percentage of calories as fat, inappropriate glucagon secretion in the absence of compensatory hyperinsulinemia limits whole body nutrient disposition. PMID:19208853

  18. Hepatic stellate cell is activated by microRNA-181b via PTEN/Akt pathway.

    PubMed

    Zheng, Jianjian; Wu, Cunzao; Xu, Ziqiang; Xia, Peng; Dong, Peihong; Chen, Bicheng; Yu, Fujun

    2015-01-01

    Activation of hepatic stellate cells (HSCs) is an essential event in the initiation and progression of liver fibrosis. MicroRNAs have been shown to play a pivotal role in regulating HSC functions such as cell proliferation, differentiation, and apoptosis. Recently, miR-181b has been reported to promote HSCs proliferation by targeting p27. But whether alpha-smooth muscle actin (α-SMA) or collagens could be promoted by miR-181b in activated HSCs is still not clear. Therefore, the understanding of the role of miR-181b in liver fibrosis remains limited. Our results showed that miR-181b expression was increased much higher than miR-181a expression in vitro in transforming growth factor-β1-induced HSC activation as well as in vivo in carbon tetrachloride-induced rat liver fibrosis. Of note, overexpression of miR-181b significantly increased the expressions level of α-SMA and type I collagen, and further promoted HSCs proliferation. Furthermore, phosphatase and tensin homologs deleted on chromosome 10 (PTEN), a negative regulator of PI3K/Akt pathway, were confirmed as a direct target of miR-181b. We demonstrated that miR-181b could suppress PTEN expression and increase Akt phosphorylation in HSCs. Interestingly, the effects of miR-181b on the activation of HSCs were blocked down by Akt inhibitor LY294002. Our results revealed a profibrotic role of miR-181b in HSC activation and demonstrated that miR-181b could activate HSCs, at least in part, via PTEN/Akt pathway.

  19. Effects of dietary tannic acid on the growth, hepatic gene expression, and antioxidant enzyme activity in Brandt's voles (Microtus brandti).

    PubMed

    Ye, Man-Hong; Nan, Yan-Lei; Ding, Meng-Meng; Hu, Jun-Bang; Liu, Qian; Wei, Wan-Hong; Yang, Sheng-Mei

    2016-01-01

    This study was designed to investigate the physiological and biochemical responses of Brandt's voles to the persistent presence of dietary tannic acid. The diet for animals in the experimental group was supplemented with 3% dietary tannic acid for 5weeks. The control group received a commercial lab chow. No significant differences were detected in body weight, organ (heart, kidney, and liver) weights, and organ parameters between animals from two groups. However, voles in the experimental group had significantly higher daily food intake, increased contents of proline and histidine in saliva and feces after protein hydrolysis, and elevated hepatic expression of transferrin than the control. Our results suggested the existence of adaptive strategies developed in Brandt's voles to overcome the adverse effects of dietary tannic acid. (1) Food consumption was increased to satisfy their nutritional demands. (2) The secretion of tannic-acid-binding salivary proteins was promoted. (3) The absorption of iron was enhanced. These alterations contributed to neutralize the negative effects of tannic acid and maintain body mass in animals supplemented with tannic acid. As the result of the consumption of tannic acid, hepatic expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase was significantly decreased, while the overall potential of the antioxidant system, characterized by increased hepatic enzymatic activities of catalase and glutathione peroxidase, was enhanced. Our results also implied the involvement of tannic acid in the regulation of lipid metabolism and oxidative stress in voles.

  20. School Programs to Increase Physical Activity

    ERIC Educational Resources Information Center

    Lee, Amelia; Solmon, Melinda

    2007-01-01

    A quality physical education program is at the heart of any plan to promote lifelong participation in physical activity, but it has become evident at many schools that physical education specialists alone cannot address the physical activity needs of children. This is why a series of studies were conducted to develop strategies for the…

  1. [Activity of liver mitochondrial NAD+-dependent dehydrogenases of the krebs cycle in rats with acetaminophen-induced hepatitis developed under conditions of alimentary protein deficiency].

    PubMed

    Voloshchuk, O N; Kopylchuk, G P

    2016-01-01

    Activity of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, malate dehydrogenase, and the NAD(+)/NADН ratio were studied in the liver mitochondrial fraction of rats with toxic hepatitis induced by acetaminophen under conditions of alimentary protein deprivation. Acetaminophen-induced hepatitis was characterized by a decrease of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase and malate dehydrogenase activities, while the mitochondrial NAD(+)/NADН ratio remained at the control level. Modeling of acetaminophen-induced hepatitis in rats with alimentary protein caused a more pronounced decrease in the activity of NAD(+)-dependent dehydrogenases studied and a 2.2-fold increase of the mitochondrial NAD(+)/NADН ratio. This suggests that alimentary protein deprivation potentiated drug-induced liver damage.

  2. Hydrogen peroxide induces La cytoplasmic shuttling and increases hepatitis C virus internal ribosome entry site-dependent translation.

    PubMed

    Chan, Shiu-Wan

    2016-09-01

    We have previously shown that physio/pathological levels of hydrogen peroxide (H2O2) stimulate translation from the hepatitis C virus (HCV) internal ribosome entry site (IRES) element in tissue-cultured cells. Here, using in vitro translation, we further show that H2O2 upregulates HCV IRES-dependent mRNA translation and correlates with an increase in intracellular oxidant level. Using Western blotting, immunocytochemistry, microscopy and affinity pulldown, we show that H2O2 stimulates HCV IRES-dependent translation and correlates with nuclear-cytoplasmic shuttling of the La autoantigen, resulting in enhanced binding of cytoplasmic La to HCV IRES RNA. The role of the La protein in H2O2-stimulated IRES-dependent translation is further confirmed by the ability of an anti-La antibody to suppress H2O2-activated IRES-dependent translation in vitro. This is further supported by the ability of an ectopically expressed dominant, negative La mutant protein to suppress H2O2-inducible IRES-mediated translation in Huh7 cells, transiently transfected with a bicistronic reporter and in a sub-genomic replicon cell line resembling a persistent infection. On the other hand, translation from the encephalomyocarditis virus IRES is diminished in the presence of H2O2, suggesting that H2O2 translational responsiveness is a specific property of the HCV IRES and is not a general phenomenon for all viral IRESs. Altogether, these results suggest that HCV adapts to physio/pathological oxidative stress in the host cell by mediating La cytoplasmic shuttling to enhance its IRES-dependent translation.

  3. Developmental changes in hepatic fructose 2,6-bisphosphate content and phosphofructokinase-1 activity in the transition of chicks from embryonic to neonatal nutritional environment.

    PubMed Central

    Hamer, M J; Dickson, A J

    1987-01-01

    Within 2 days of hatching in chicks, there are parallel increases in hepatic fructose 2,6-bisphosphate content and phosphofructokinase-1 activity. The changes observed are a consequence of feeding on the carbohydrate-rich diet of neonatal life: lack of access to food after hatching prevents changes for either parameter. The results are discussed in relation to changes in the activities of hepatic lipogenic enzymes during the embryonic/neonatal transition of chicks and the role of insulin in co-ordination of developmental processes. PMID:2959273

  4. Activated hepatic stellate cells impair NK cell anti-fibrosis capacity through a TGF-β-dependent emperipolesis in HBV cirrhotic patients.

    PubMed

    Shi, Jijing; Zhao, Juanjuan; Zhang, Xin; Cheng, Yongqian; Hu, Jinhua; Li, Yuanyuan; Zhao, Xin; Shang, Qinghua; Sun, Yanling; Tu, Bo; Shi, Lei; Gao, Bin; Wang, Fu-Sheng; Zhang, Zheng

    2017-03-14

    Natural killer (NK) cells can induce liver fibrosis remission by killing hepatic stellate cells (HSCs) and producing interferon (IFN)-γ in a mouse model; however, their anti-fibrotic immune-characteristics and regulatory mechanisms by HSCs remain to be determined, especially in livers from HBV-infected liver cirrhosis (LC) patients. We analyzed frequency, phenotype and anti-fibrotic function of hepatic and peripheral NK subsets in 43 HBV-LC patients. We found that hepatic NK subsets from LC patients displayed a decreased frequency, activation status and anti-fibrotic activity compared with those from chronic hepatitis B patients, which were mainly mediated by increased intrahepatic tumour-growth factor (TGF)-β because blockade of TGF-β significantly reversed NK anti-fibrotic function in vitro. In vivo, hepatic NK cells were enriched in proximity to the α-smooth muscle actin (α-SMA+) area within mild fibrosis regions; while in severe fibrotic areas, they were either directly attached to or separated from the α-SMA+ region. NK cells from LC patients could enter HSCs to form emperipolesis (a cell-in-cell structure) and become apoptotic; anti-TGF-β treatment ameliorated this emperipolesis. This finding suggested a novel mechanism by which activated HSCs impair NK cells' anti-fibrosis capacity through a TGF-β-dependent emperipolesis in LC patients, providing an anti-fibrotic rational by enhancing NK cell activity.

  5. Activated hepatic stellate cells impair NK cell anti-fibrosis capacity through a TGF-β-dependent emperipolesis in HBV cirrhotic patients

    PubMed Central

    Shi, Jijing; Zhao, Juanjuan; Zhang, Xin; Cheng, Yongqian; Hu, Jinhua; Li, Yuanyuan; Zhao, Xin; Shang, Qinghua; Sun, Yanling; Tu, Bo; Shi, Lei; Gao, Bin; Wang, Fu-Sheng; Zhang, Zheng

    2017-01-01

    Natural killer (NK) cells can induce liver fibrosis remission by killing hepatic stellate cells (HSCs) and producing interferon (IFN)-γ in a mouse model; however, their anti-fibrotic immune-characteristics and regulatory mechanisms by HSCs remain to be determined, especially in livers from HBV-infected liver cirrhosis (LC) patients. We analyzed frequency, phenotype and anti-fibrotic function of hepatic and peripheral NK subsets in 43 HBV-LC patients. We found that hepatic NK subsets from LC patients displayed a decreased frequency, activation status and anti-fibrotic activity compared with those from chronic hepatitis B patients, which were mainly mediated by increased intrahepatic tumour-growth factor (TGF)-β because blockade of TGF-β significantly reversed NK anti-fibrotic function in vitro. In vivo, hepatic NK cells were enriched in proximity to the α-smooth muscle actin (α-SMA+) area within mild fibrosis regions; while in severe fibrotic areas, they were either directly attached to or separated from the α-SMA+ region. NK cells from LC patients could enter HSCs to form emperipolesis (a cell-in-cell structure) and become apoptotic; anti-TGF-β treatment ameliorated this emperipolesis. This finding suggested a novel mechanism by which activated HSCs impair NK cells’ anti-fibrosis capacity through a TGF-β-dependent emperipolesis in LC patients, providing an anti-fibrotic rational by enhancing NK cell activity. PMID:28291251

  6. Aguamiel concentrate from Agave salmiana and its extracted saponins attenuated obesity and hepatic steatosis and increased Akkermansia muciniphila in C57BL6 mice

    PubMed Central

    Leal-Díaz, Ana María; Noriega, Lilia G.; Torre-Villalvazo, Ivan; Torres, Nimbe; Alemán-Escondrillas, Gabriela; López-Romero, Patricia; Sánchez-Tapia, Mónica; Aguilar-López, Miriam; Furuzawa-Carballeda, Janette; Velázquez-Villegas, Laura A.; Avila-Nava, Azalia; Ordáz, Guillermo; Gutiérrez-Uribe, Janet A.; Serna-Saldivar, Sergio O.; Tovar, Armando R.

    2016-01-01

    Obesity and its comorbidities are a severe public health problem worldwide. The use of bioactive compounds found in some foods has been demonstrated to ameliorate the metabolic abnormalities associated with obesity. The purpose of this study was to assess whether the bioactive compounds present in aguamiel concentrate (AC) from Agave salmiana could attenuate glucose intolerance and hepatic steatosis in mice fed a high fat (HF) diet. HPLC-ELSD analysis showed that AC contained several saponins. The consumption of an AC extract rich in saponins reduced weight gain and fat mass and lowered serum glucose, insulin and LDL-cholesterol levels in mice fed a HF diet. Additionally, mice fed the saponin extract exhibited a reduced HOMA index and hepatic lipid levels and increased expression of genes involved in fatty acid oxidation. Saponins increased white adipose tissue browning, AMPK phosphorylation, fatty acid oxidation, and mitochondrial activity in skeletal muscle and energy expenditure in mice fed the HF diet. These metabolic changes were accompanied by an increase in the abundance of Akkermansia muciniphila in the gut microbiota. Therefore, Agave salmiana saponins can be an alternative to attenuate the metabolic changes that accompany obesity. PMID:27678062

  7. Aguamiel concentrate from Agave salmiana and its extracted saponins attenuated obesity and hepatic steatosis and increased Akkermansia muciniphila in C57BL6 mice.

    PubMed

    Leal-Díaz, Ana María; Noriega, Lilia G; Torre-Villalvazo, Ivan; Torres, Nimbe; Alemán-Escondrillas, Gabriela; López-Romero, Patricia; Sánchez-Tapia, Mónica; Aguilar-López, Miriam; Furuzawa-Carballeda, Janette; Velázquez-Villegas, Laura A; Avila-Nava, Azalia; Ordáz, Guillermo; Gutiérrez-Uribe, Janet A; Serna-Saldivar, Sergio O; Tovar, Armando R

    2016-09-28

    Obesity and its comorbidities are a severe public health problem worldwide. The use of bioactive compounds found in some foods has been demonstrated to ameliorate the metabolic abnormalities associated with obesity. The purpose of this study was to assess whether the bioactive compounds present in aguamiel concentrate (AC) from Agave salmiana could attenuate glucose intolerance and hepatic steatosis in mice fed a high fat (HF) diet. HPLC-ELSD analysis showed that AC contained several saponins. The consumption of an AC extract rich in saponins reduced weight gain and fat mass and lowered serum glucose, insulin and LDL-cholesterol levels in mice fed a HF diet. Additionally, mice fed the saponin extract exhibited a reduced HOMA index and hepatic lipid levels and increased expression of genes involved in fatty acid oxidation. Saponins increased white adipose tissue browning, AMPK phosphorylation, fatty acid oxidation, and mitochondrial activity in skeletal muscle and energy expenditure in mice fed the HF diet. These metabolic changes were accompanied by an increase in the abundance of Akkermansia muciniphila in the gut microbiota. Therefore, Agave salmiana saponins can be an alternative to attenuate the metabolic changes that accompany obesity.

  8. Increased toll-like receptor 4 in cerebral endothelial cells contributes to the astrocyte swelling and brain edema in acute hepatic encephalopathy.

    PubMed

    Jayakumar, Arumugam R; Tong, Xiao Y; Curtis, Kevin M; Ruiz-Cordero, Roberto; Abreu, Maria T; Norenberg, Michael D

    2014-03-01

    Astrocyte swelling and the subsequent increase in intracranial pressure and brain herniation are major clinical consequences in patients with acute hepatic encephalopathy. We recently reported that conditioned media from brain endothelial cells (ECs) exposed to ammonia, a mixture of cytokines (CKs) or lipopolysaccharide (LPS), when added to astrocytes caused cell swelling. In this study, we investigated the possibility that ammonia and inflammatory agents activate the toll-like receptor 4 (TLR4) in ECs, resulting in the release of factors that ultimately cause astrocyte swelling. We found a significant increase in TLR4 protein expression when ECs were exposed to ammonia, CKs or LPS alone, while exposure of ECs to a combination of these agents potentiate such effects. In addition, astrocytes exposed to conditioned media from TLR4-silenced ECs that were treated with ammonia, CKs or LPS, resulted in a significant reduction in astrocyte swelling. TLR4 protein up-regulation was also detected in rat brain ECs after treatment with the liver toxin thioacetamide, and that thioacetamide-treated TLR4 knock-out mice exhibited a reduction in brain edema. These studies strongly suggest that ECs significantly contribute to the astrocyte swelling/brain edema in acute hepatic encephalopathy, likely as a consequence of increased TLR4 protein expression by blood-borne noxious agents.

  9. Macrophage Activation in Pediatric Nonalcoholic Fatty Liver Disease (NAFLD) Correlates with Hepatic Progenitor Cell Response via Wnt3a Pathway

    PubMed Central

    Renzi, Anastasia; De Stefanis, Cristiano; Stronati, Laura; Franchitto, Antonio; Alisi, Anna; Onori, Paolo; De Vito, Rita; Alpini, Gianfranco; Gaudio, Eugenio

    2016-01-01

    Non-alcoholic fatty liver disease is one of the most important causes of liver-related morbidity in children. In non-alcoholic fatty liver disease, the activation of liver resident macrophage pool is a central event in the progression of liver injury. The aims of the present study were to evaluate the polarization of liver macrophages and the possible role of Wnt3a production by macrophages in hepatic progenitor cell response in the progression of pediatric non-alcoholic fatty liver disease. 32 children with biopsy-proven non-alcoholic fatty liver disease were included. 20 out of 32 patients were treated with docosahexaenoic acid for 18 months and biopsies at the baseline and after 18 months were included. Hepatic progenitor cell activation, macrophage subsets and Wnt/β-catenin pathway were evaluated by immunohistochemistry and immunofluorescence. Our results indicated that in pediatric non-alcoholic fatty liver disease, pro-inflammatory macrophages were the predominant subset. Macrophage polarization was correlated with Non-alcoholic fatty liver disease Activity Score, ductular reaction, and portal fibrosis; docosahexaenoic acid treatment determined a macrophage polarization towards an anti-inflammatory phenotype in correlation with the reduction of serum inflammatory cytokines, with increased macrophage apoptosis, and with the up-regulation of macrophage Wnt3a expression; macrophage Wnt3a expression was correlated with β-catenin phosphorylation in hepatic progenitor cells and signs of commitment towards hepatocyte fate. In conclusion, macrophage polarization seems to have a key role in the progression of pediatric non-alcoholic fatty liver disease; the modulation of macrophage polarization could drive hepatic progenitor cell response by Wnt3a production. PMID:27310371

  10. Induction of rat hepatic cytochromes P450 by toxic ingredients in plants: lack of correlation between toxicity and inductive activity.

    PubMed

    Yamada, H; Nakamura, T; Oguri, K

    1998-12-01

    "Animal-Plant Warfare" is one of the hypotheses for the evolution of drug-metabolizing P450s. To address the validity of this hypothesis, we examined the induction of xenobiotic-metabolizing P450s by 12 plant toxins in rats, using hepatic activity for testosterone metabolism as the index. The compounds tested were aconitine, morphine, tubocurarine, physostigmine, pilocarpine, muscarine, cocaine, atropine, amygdalin, digitonin, nicotine and solanine. Drinking water containing a test compound was given to rats for 4 days, and the hepatic activity of testosterone metabolism was determined together with monitoring body weight gain and liver weight as the indices of toxicity. The results showed that while cocaine and nicotine have a minor ability to increase testosterone 16 beta-hydroxylase activity, a marker activity for the CYP2B1 and 2, all other compounds did not have any such effect. No correlation was observed between a change in 16 beta-hydroxylase and toxicity caused by toxins. Therefore, these results did not support the idea that the inducibility of the CYP2B subfamily in animals is acquired through "Animal-Plant Warfare". Several compounds examined here increased or decreased hepatic activities of testosterone 2 alpha-, 6 beta-, 7 alpha- and 16 alpha-hydroxylation and 17-oxidation, indicating a possible effect on the CYP2A, 2C and 3A subfamily. Of these effects, a moderate correlation (r < 0.49) was observed in the changes in the activities of 2 alpha-/16 alpha-hydroxylation and 17-oxidation vs. that in toxicity. It is therefore suggested that inhibition or suppression of the expression of CYP2C11 is one of the mechanisms in the toxicity of plant toxins for rats, although it comes from an examination using limited numbers of compounds.

  11. Does Pay-For-Performance Program Increase Providers Adherence to Guidelines for Managing Hepatitis B and Hepatitis C Virus Infection in Taiwan?

    PubMed Central

    Chen, Long-Sheng; Chou, Yiing-Jenq; Li, Chung-Pin; Wu, Chen-Yi; Chang, Yu-Chia

    2016-01-01

    Background Many people are concerned about that the quality of preventive care for patients with hepatitis B virus (HBV) and hepatitis C virus (HCV) infection is suboptimal. Taiwan, a hyperendemic area of chronic HBV and HCV infection, implemented a nationwide pay-for-performance (P4P) program in 2010, which aimed to improve the preventive care provided to HBV and HCV patients by increasing physicians’ adherence to guidelines through financial incentives. The objective of this study was to evaluate the early effects of the P4P program on utilization of preventive services by HBV and HCV patients. Methods Using a quasi-experimental design with propensity score matching method, we matched the HBV and HCV patients enrolled in the P4P program with non-enrollees in 2010, resulting in 21,643 patients in each group. Generalized estimating equations was applied to examine the difference-in-difference effects of P4P program enrollment on the utilization of three guideline-recommended preventive services (regular outpatient follow-up visits, abdominal ultrasonography (US) examinations, and aspartate aminotransferase and alanine aminotransferase (AST/ALT) tests by HBV and HCV patients. Results The P4P program enrollees were significantly more likely to attend twice-annual follow-up visits, to receive recommended US examinations and AST/ALT tests, than non-enrollees. Conclusions The results of our preliminary assessment indicate that financial incentives offered by the P4P program was associated with a modest improvement in adherence to guidelines for better chronic HBV and HBC management. PMID:27517172

  12. Trans-activation function of a 3 prime truncated X gene-cell fusion product from integrated hepatitis B virus DNA in chronic hepatitis tissues

    SciTech Connect

    Takada, Shinako; Koike, Katsuro )

    1990-08-01

    To investigate the expression and transactivation function of the X gene in integrated hepatitis B virus (HBV) DNA from chronic hepatitis tissues, a series of transfectants containing cloned integrated HBV DNAs was made and analyzed for X mRNA expression and trans-activation activity by using a chloramphenicol acetyltransferase assay. Most of the integrated HBV DNAs expressed X mRNA and encoded a product with trans-activation activity in spite of the loss of the 3{prime} end region of the X gene due to integration. From cDNA cloning and sequence analysis of X mRNA transcribed from native or integrated HBV DNA, the X protein was found to be translated from the X open reading frame without splicing. For integrated HBV DNA, transcription was extended to a cellular flanking DNA and an X gene-cell fusion transcript was terminated by using a cellular poly(A) signal. The amino acid sequence deduced from an X-cell fusion transcript indicated truncation of the carboxyl-terminal five amino acids, but the upstream region of seven amino acids conserved among hepadnaviruses was retained in the integrated HBV DNA, suggesting that this conserved region is essential for the transactivation function of the X protein. These findings support the following explanation for hepatocarcinogenesis by HBV DNA integration: the expression of a cellular oncogene(s) is transactivated at the time of chronic infection by the increasing amounts of the integrated HBV gene product(s), such as the X-cell fusion product.

  13. Mapping Metabolic Brain Activity in Three Models of Hepatic Encephalopathy

    PubMed Central

    Méndez, Marta; Fidalgo, Camino; Aller, María Ángeles; Arias, Jaime; Arias, Jorge L.

    2013-01-01

    Cirrhosis is a common disease in Western countries. Liver failure, hyperammonemia, and portal hypertension are the main factors that contribute to human cirrhosis that frequently leads to a neuropsychiatric disorder known as hepatic encephalopathy (HE). In this study, we examined the differential contribution of these leading factors to the oxidative metabolism of diverse brain limbic system regions frequently involved in memory process by histochemical labelling of cytochrome oxidase (COx). We have analyzed cortical structures such as the infralimbic and prelimbic cotices, subcortical structures such as hippocampus and ventral striatum, at thalamic level like the anterodorsal, anteroventral, and mediodorsal thalamus, and, finally, the hypothalamus, where the mammillary nuclei (medial and lateral) were measured. The severest alteration is found in the model that mimics intoxication by ammonia, followed by the thioacetamide-treated group and the portal hypertension group. No changes were found at the mammillary bodies for any of the experimental groups. PMID:23573412

  14. Prolyl oligopeptidase attenuates hepatic stellate cell activation through induction of Smad7 and PPAR-γ

    PubMed Central

    Zhou, Da; Wang, Jing; He, Ling-Nan; Li, Bing-Hang; Ding, Yong-Nian; Chen, Yuan-Wen; Fan, Jian-Gao

    2017-01-01

    Prolyl oligopeptidase (POP) is a serine endopeptidase widely distributed in vivo with high activity in the liver. However, its biological functions in the liver have remained largely elusive. A previous study by our group has shown that POP produced N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) and thereby exerted an anti-fibrogenic effect on hepatic stellate cells (HSCs) in vitro. It was therefore hypothesized that POP may affect the activation state of HSCs and has an important role in liver fibrosis. The HSC-T6 immortalized rat liver stellate cell line was treated with the POP inhibitor S17092 or transfected with recombinant lentivirus to overexpress POP. Cell proliferation and apoptosis were determined using a Cell Counting Kit-8 and flow cytometry, respectively. The activation status of HSCs was determined by examination of the expression of α-smooth muscle actin (α-SMA), collagen I, monocyte chemoattractant protein-1 (MCP-1), transforming growth factor (TGF)-β-Smad signaling and peroxisome proliferator activated receptor-γ (PPAR-γ). Inhibition by S17092 decreased, whereas lentiviral expression increased the activity of POP and cell proliferation, while neither of the treatments affected cell apoptosis. Of note, S17092 significantly increased, whereas POP overexpression decreased the expression of α-SMA and MCP-1 without affecting the expression of collagen I and TGF-β1. Furthermore, S17092 caused a reduction, whereas POP overexpression caused an upregulation of Smad7 protein and PPAR-γ, but not phosphorylated-Smad2/3 expression. In conclusion, POP attenuated the activation of HSCs through inhibition of TGF-β signaling and induction of PPAR-γ, which may have therapeutic potential in liver fibrosis. PMID:28352366

  15. FLUCONAZOLE-INDUCED HEPATIC CYTOCHROME P450 GENE EXPRESSION AND ENZYMATIC ACTIVITIES IN RATS AND MICE

    EPA Science Inventory

    This study was undertaken to examine the effects of the triazole antifungal agent fluconazole on the expression of hepatic cytochrome P450 (Cyp) genes and the activities of Cyp enzymes in male Sprague-Dawley rats and male CD-1 mice. Alkoxyresorufin O-dealkylation (AROD) methods w...

  16. Immune Activation Response in Chronic HIV-Infected Patients: Influence of Hepatitis C Virus Coinfection

    PubMed Central

    Márquez, Mercedes; Romero-Cores, Paula; Montes-Oca, Monserrat; Martín-Aspas, Andrés; Soto-Cárdenas, María-José; Guerrero, Francisca; Fernández-Gutiérrez, Clotilde; Girón-González, José-Antonio

    2015-01-01

    Objectives We have analyzed the parameters (bacterial translocation, immune activation and regulation, presence of HCV coinfection) which could be implicated in an inappropriate immune response from individuals with chronic HIV infection. The influence of them on the evolution of CD4+ T cell count has been investigated. Patients and methods Seventy HIV-infected patients [monoinfected by HIV (n = 20), HCV-coinfected (with (n = 25) and without (n = 25) liver cirrhosis)] and 25 healthy controls were included. Median duration of HIV infection was 20 years. HIV- and HCV-related parameters, as well as markers relative to bacterial translocation, monocyte and lymphocyte activation and regulation were considered as independent variables. Dependent variables were the increase of CD4+ T cell count during the follow-up (12 months). Results Increased values of bacterial translocation, measured by lipopolysaccharide-binding protein, monocyte and lymphocyte activation markers and T regulatory lymphocytes were detected in HIV-monoinfected and HIV/HCV coinfected patients. Serum sCD14 and IL-6 were increased in HIV/HCV-coinfected patients with liver cirrhosis in comparison with those with chronic hepatitis or HIV-monoinfected individuals. Time with undetectable HIV load was not related with these parameters. The presence of cirrhosis was negatively associated with a CD4+ T cell count increase. Conclusion In patients with a chronic HIV infection, a persistent increase of lipopolysaccharide-binding protein and monocyte and lymphocyte modifications are present. HCV-related cirrhosis is associated with more elevated serum concentrations of monocyte-derived markers. Cirrhosis influences the continued immune reconstitution of these patients. PMID:25775475

  17. The calcium-activated potassium channel KCa3.1 is an important modulator of hepatic injury.

    PubMed

    Sevelsted Møller, Linda; Fialla, Annette Dam; Schierwagen, Robert; Biagini, Matteo; Liedtke, Christian; Laleman, Wim; Klein, Sabine; Reul, Winfried; Koch Hansen, Lars; Rabjerg, Maj; Singh, Vikrant; Surra, Joaquin; Osada, Jesus; Reinehr, Roland; de Muckadell, Ove B Schaffalitzky; Köhler, Ralf; Trebicka, Jonel

    2016-06-29

    The calcium-activated potassium channel KCa3.1 controls different cellular processes such as proliferation and volume homeostasis. We investigated the role of KCa3.1 in experimental and human liver fibrosis. KCa3.1 gene expression was investigated in healthy and injured human and rodent liver. Effect of genetic depletion and pharmacological inhibition of KCa3.1 was evaluated in mice during carbon tetrachloride induced hepatic fibrogenesis. Transcription, protein expression and localisation of KCa3.1 was analysed by reverse transcription polymerase chain reaction, Western blot and immunohistochemistry. Hemodynamic effects of KCa3.1 inhibition were investigated in bile duct-ligated and carbon tetrachloride intoxicated rats. In vitro experiments were performed in rat hepatic stellate cells and hepatocytes. KCa3.1 expression was increased in rodent and human liver fibrosis and was predominantly observed in the hepatocytes. Inhibition of KCa3.1 aggravated liver fibrosis during carbon tetrachloride challenge but did not change hemodynamic parameters in portal hypertensive rats. In vitro, KCa3.1 inhibition leads to increased hepatocyte apoptosis and DNA damage, whereas proliferation of hepatic stellate cells was stimulated by KCa3.1 inhibition. Our data identifies KCa3.1 channels as important modulators in hepatocellular homeostasis. In contrast to previous studies in vitro and other tissues this channel appears to be anti-fibrotic and protective during liver injury.

  18. Long-term fructose consumption prolongs hepatic stearoyl-CoA desaturase 1 activity independent of upstream regulation in rats.

    PubMed

    Liu, Li; Wang, Shang; Yao, Ling; Li, Jin-Xiu; Ma, Peng; Jiang, Li-Rong; Ke, Da-Zhi; Pan, Yong-Quan; Wang, Jian-Wei

    2016-10-28

    Dietary fructose is considered a risk factor for metabolic disorders, such as fatty liver disease. However, the mechanism underlying the effects of fructose is not well characterized. We investigated the hepatic expression of key regulatory genes related to lipid metabolism following fructose feeding under well-defined conditions. Rats were fed standard chow supplemented with 10% w/v fructose solution for 5 weeks, and killed after chow-fasting and fructose withdrawal (fasting) or chow-fasting and continued fructose (fructose alone) for 14 h. Hepatic deposition of triglycerides was found in rats from both groups. As expected, fructose alone increased mRNA levels of lipogenesis-related genes and correspondingly decreased mRNA levels of lipid oxidative genes in the liver. Interesting, hepatic levels of stearoyl-CoA desaturase (SCD)1 mRNA remained elevated under fructose withdrawn conditions, although expression levels of other genes, including two key transcription factors (carbohydrate response element binding protein (ChREBP) and sterol regulatory element-binding protein (SREBP)-1c) fell to normal levels, indicating that long-term fructose intake increased SCD1 activity, independent of upstream regulatory genes, such as ChREBP and SREBP-1c. In conclusion, SCD1 overexpression in fatty liver disease is not affected by fasting after long-term fructose consumption in rats. Regulation of SCD1 plays an important role in fructose-induced hepatic steatosis.

  19. The calcium-activated potassium channel KCa3.1 is an important modulator of hepatic injury

    PubMed Central

    Sevelsted Møller, Linda; Fialla, Annette Dam; Schierwagen, Robert; Biagini, Matteo; Liedtke, Christian; Laleman, Wim; Klein, Sabine; Reul, Winfried; Koch Hansen, Lars; Rabjerg, Maj; Singh, Vikrant; Surra, Joaquin; Osada, Jesus; Reinehr, Roland; de Muckadell, Ove B. Schaffalitzky; Köhler, Ralf; Trebicka, Jonel

    2016-01-01

    The calcium-activated potassium channel KCa3.1 controls different cellular processes such as proliferation and volume homeostasis. We investigated the role of KCa3.1 in experimental and human liver fibrosis. KCa3.1 gene expression was investigated in healthy and injured human and rodent liver. Effect of genetic depletion and pharmacological inhibition of KCa3.1 was evaluated in mice during carbon tetrachloride induced hepatic fibrogenesis. Transcription, protein expression and localisation of KCa3.1 was analysed by reverse transcription polymerase chain reaction, Western blot and immunohistochemistry. Hemodynamic effects of KCa3.1 inhibition were investigated in bile duct-ligated and carbon tetrachloride intoxicated rats. In vitro experiments were performed in rat hepatic stellate cells and hepatocytes. KCa3.1 expression was increased in rodent and human liver fibrosis and was predominantly observed in the hepatocytes. Inhibition of KCa3.1 aggravated liver fibrosis during carbon tetrachloride challenge but did not change hemodynamic parameters in portal hypertensive rats. In vitro, KCa3.1 inhibition leads to increased hepatocyte apoptosis and DNA damage, whereas proliferation of hepatic stellate cells was stimulated by KCa3.1 inhibition. Our data identifies KCa3.1 channels as important modulators in hepatocellular homeostasis. In contrast to previous studies in vitro and other tissues this channel appears to be anti-fibrotic and protective during liver injury. PMID:27354175

  20. Central neural regulation by adrenergic nerves of the daily rhythm in hepatic tyrosine transaminase activity

    PubMed Central

    Black, Ira B.; Reis, Donald J.

    1971-01-01

    1. In adrenalectomized fasted rats transection of the spinal cord at C7-C8 or placement of bilateral electrolytic lesions in the lateral hypothalamus when performed in the morning interrupted the daily rhythm of hepatic tyrosine transaminase by elevating low (AM) enzyme activities to high (PM) levels; lesions placed in PM did not affect the late afternoon rise in enzyme activity. 2. Bilateral thalamic lesions had no affect on enzyme activity. 3. The activity of hepatic catechol-O-methyl transferase was unaffected by hypothalamic lesions. 4. The lesion-evoked rise of tyrosine transaminase activity was abolished by exogenously administered norepinephrine. 5. Cycloheximide blocked the rise of tyrosine transaminase activity caused by hypothalamic lesions. 6. The results suggest that rhythmic activity of sympathetic nerves governed by lateral hypothalamus contribute to regulation of the daily rhythm in tyrosine transaminase by regulating the release of norepinephrine peripherally; norepinephrine may block the daily rise of enzyme by interfering with protein synthesis, possibly of new enzyme, by competing with pyridoxal co-factor. 7. It is proposed that alternating activity of sympathetic-adrenergic and vagal-cholinergic nerves to liver, controlled by the C.N.S., contribute to rhythmic activity of hepatic tyrosine transaminase. ImagesFig. 2 PMID:4400586

  1. Increased depressive ratings in patients with hepatitis C receiving interferon-alpha-based immunotherapy are related to interferon-alpha-induced changes in the serotonergic system.

    PubMed

    Bonaccorso, Stefania; Marino, Valentina; Puzella, Antonella; Pasquini, Massimo; Biondi, Massimo; Artini, Marco; Almerighi, Cristiana; Verkerk, Robert; Meltzer, Herbert; Maes, Michael

    2002-02-01

    There is now evidence that repeated administration of interferon-alpha (IFN-alpha) to patients with chronic active hepatitis and cancers induces depressive symptoms. There is also evidence that induction of the cytokine network modulates the serotonergic system and that major depression is related to activation of the cytokine network and disturbances in the serotonergic metabolism. The aims of this study were to examine the effects of IFN-alpha-based immunotherapy on the development of depressive symptoms in relation to its effects on plasma tryptophan and kynurenine and serum serotonin (5-HT). Eighteen patients affected by chronic active hepatitis C were treated with IFN-alpha (3-6 million units subcutaneously three to six times a week for 6 months) and had measurements of the previous parameters before starting immunotherapy and 2, 4, 16, and 24 weeks later. Severity of depression and anxiety were measured with the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Rating Scale for Anxiety (HAM-A) scale, respectively. Immunochemotherapy with IFN-alpha (1) significantly increased the MADRS and HAM-A scores and serum kynurenine concentrations and (2) significantly reduced plasma tryptophan and serum 5-HT concentrations. IFN-alpha-based immunotherapy significantly increased the kynurenine per tryptophan quotient, which estimates the activity of indoleamine 2,3-dioxygenase, the major tryptophan-catabolizing enzyme, which is induced by IFNs. There are significant relationships between the IFN-alpha-induced changes in the MADRS score and serum kynurenine (positive) and 5-HT (negative) concentrations. Immunotherapy with IFN-alpha significantly increases the severity of depressive symptoms. The latter is related to changes in the serotonergic system, such as depletion of serum 5-HT and induction of the catabolism of tryptophan to kynurenine. It is suggested that the IFN-alpha-induced changes in the serotonergic turnover could play a role in the

  2. PPARδ activation induces hepatic long-chain acyl-CoA synthetase 4 expression in vivo and in vitro

    PubMed Central

    Kan, Chin Fung Kelvin; Singh, Amar Bahadur; Dong, Bin; Shende, Vikram Ravindra; Liu, Jingwen

    2017-01-01

    The arachidonic acid preferred long-chain acyl-CoA synthetase 4 (ACSL4) is a key enzyme for fatty acid metabolism in various metabolic tissues. In this study, we utilized hamsters fed a normal chow diet, a high-fat diet or a high cholesterol and high fat diet (HCHFD) as animal models to explore novel transcriptional regulatory mechanisms for ACSL4 expression under hyperlipidemic conditions. Through cloning hamster ACSL4 homolog and tissue profiling ACSL4 mRNA and protein expressions we observed a selective upregulation of ACSL4 in testis and liver of HCHFD fed animals. Examination of transcriptional activators of the ACSL family revealed an increased hepatic expression of PPARδ but not PPARα in HCHFD fed hamsters. To explore a role of PPARδ in dietary cholesterol-mediated upregulation of ACSL4, we administered a PPARδ specific agonist L165041 to normolipidemic and dyslipidemic hamsters. We observed significant increases of hepatic ACSL4 mRNA and protein levels in all L165041-treated hamsters as compared to control animals. The induction of ACSL4 expression by L165041 in liver tissue in vivo was recapitulated in human primary hepatocytes and hepatocytes isolated from hamster and mouse. Moreover, employing the approach of adenovirus-mediated gene knockdown, we showed that depletion of PPARδ in hamster hepatocytes specifically reduced ACSL4 expression. Finally, utilizing HepG2 as a model system, we demonstrate that PPARδ activation leads to increased ACSL4 promoter activity, mRNA and protein expression, and consequently higher arachidonoyl-CoA synthetase activity. Taken together, we have discovered a novel PPARδ-mediated regulatory mechanism for ACSL4 expression in liver tissue and cultured hepatic cells. PMID:25645621

  3. PPARδ activation induces hepatic long-chain acyl-CoA synthetase 4 expression in vivo and in vitro.

    PubMed

    Kan, Chin Fung Kelvin; Singh, Amar Bahadur; Dong, Bin; Shende, Vikram Ravindra; Liu, Jingwen

    2015-05-01

    The arachidonic acid preferred long-chain acyl-CoA synthetase 4 (ACSL4) is a key enzyme for fatty acid metabolism in various metabolic tissues. In this study, we utilized hamsters fed a normal chow diet, a high-fat diet or a high cholesterol and high fat diet (HCHFD) as animal models to explore novel transcriptional regulatory mechanisms for ACSL4 expression under hyperlipidemic conditions. Through cloning hamster ACSL4 homolog and tissue profiling ACSL4 mRNA and protein expressions we observed a selective upregulation of ACSL4 in testis and liver of HCHFD fed animals. Examination of transcriptional activators of the ACSL family revealed an increased hepatic expression of PPARδ but not PPARα in HCHFD fed hamsters. To explore a role of PPARδ in dietary cholesterol-mediated upregulation of ACSL4, we administered a PPARδ specific agonist L165041 to normolipidemic and dyslipidemic hamsters. We observed significant increases of hepatic ACSL4 mRNA and protein levels in all L165041-treated hamsters as compared to control animals. The induction of ACSL4 expression by L165041 in liver tissue in vivo was recapitulated in human primary hepatocytes and hepatocytes isolated from hamster and mouse. Moreover, employing the approach of adenovirus-mediated gene knockdown, we showed that depletion of PPARδ in hamster hepatocytes specifically reduced ACSL4 expression. Finally, utilizing HepG2 as a model system, we demonstrate that PPARδ activation leads to increased ACSL4 promoter activity, mRNA and protein expression, and consequently higher arachidonoyl-CoA synthetase activity. Taken together, we have discovered a novel PPARδ-mediated regulatory mechanism for ACSL4 expression in liver tissue and cultured hepatic cells.

  4. FGF19 as a postprandial, insulin-independent activator of hepatic protein and glycogen synthesis.

    PubMed

    Kir, Serkan; Beddow, Sara A; Samuel, Varman T; Miller, Paul; Previs, Stephen F; Suino-Powell, Kelly; Xu, H Eric; Shulman, Gerald I; Kliewer, Steven A; Mangelsdorf, David J

    2011-03-25

    Fibroblast growth factor (FGF) 19 is an enterokine synthesized and released when bile acids are taken up into the ileum. We show that FGF19 stimulates hepatic protein and glycogen synthesis but does not induce lipogenesis. The effects of FGF19 are independent of the activity of either insulin or the protein kinase Akt and, instead, are mediated through a mitogen-activated protein kinase signaling pathway that activates components of the protein translation machinery and stimulates glycogen synthase activity. Mice lacking FGF15 (the mouse FGF19 ortholog) fail to properly maintain blood concentrations of glucose and normal postprandial amounts of liver glycogen. FGF19 treatment restored the loss of glycogen in diabetic animals lacking insulin. Thus, FGF19 activates a physiologically important, insulin-independent endocrine pathway that regulates hepatic protein and glycogen metabolism.

  5. The Flavone Luteolin Suppresses SREBP-2 Expression and Post-Translational Activation in Hepatic Cells

    PubMed Central

    Wong, Tsz Yan; Lin, Shu-mei; Leung, Lai K.

    2015-01-01

    High blood cholesterol has been associated with cardiovascular diseases. The enzyme HMG CoA reductase (HMGCR) is responsible for cholesterol synthesis, and inhibitors of this enzyme (statins) have been used clinically to control blood cholesterol. Sterol regulatory element binding protein (SREBP) -2 is a key transcription factor in cholesterol metabolism, and HMGCR is a target gene of SREBP-2. Attenuating SREBP-2 activity could potentially minimize the expression of HMGCR. Luteolin is a flavone that is commonly detected in plant foods. In the present study, Luteolin suppressed the expression of SREBP-2 at concentrations as low as 1 μM in the hepatic cell lines WRL and HepG2. This flavone also prevented the nuclear translocation of SREBP-2. Post-translational processing of SREBP-2 protein was required for nuclear translocation. Luteolin partially blocked this activation route through increased AMP kinase (AMPK) activation. At the transcriptional level, the mRNA and protein expression of SREBP-2 were reduced through luteolin. A reporter gene assay also verified that the transcription of SREBF2 was weakened in response to this flavone. The reduced expression and protein processing of SREBP-2 resulted in decreased nuclear translocation. Thus, the transcription of HMGCR was also decreased after luteolin treatment. In summary, the results of the present study showed that luteolin modulates HMGCR transcription by decreasing the expression and nuclear translocation of SREBP-2. PMID:26302339

  6. Changes in the regional homogeneity of resting-state brain activity in minimal hepatic encephalopathy.

    PubMed

    Chen, Hua-Jun; Zhu, Xi-Qi; Yang, Ming; Liu, Bin; Zhang, Yi; Wang, Yu; Teng, Gao-Jun

    2012-01-17

    Resting-state functional magnetic resonance imaging (fMRI) has facilitated the study of spontaneous brain activity by measuring low-frequency oscillations in blood-oxygen-level-dependent signals. Analyses of regional homogeneity (ReHo), which reflects the local synchrony of neural activity, have been used to reveal the mechanisms underlying the brain dysfunction in various neuropsychiatric diseases. However, it is not known whether the ReHo is altered in cirrhotic patients with minimal hepatic encephalopathy (MHE). We recruited 18 healthy controls and 18 patients with MHE. The ReHo was calculated to assess the strength of the local signal synchrony. Compared with the healthy controls, the patients with MHE had significantly decreased ReHo in the cuneus and adjacent precuneus, and left inferior parietal lobe, whereas the regions showing increased ReHo in patients with MHE included the left parahippocampal gyrus, right cerebellar vermis, and bilateral anterior cerebellar lobes. We found a positive correlation between the mean ReHo in the cuneus and adjacent precuneus and the score on the digit-symbol test in the patient group. In conclusion, the analysis of the regional homogeneity of resting-state brain activity may provide additional information with respect to a clinical definition of MHE.

  7. Hepatic injury induces contrasting response in liver and kidney to chemicals that are metabolically activated: Role of male sex hormone

    SciTech Connect

    Kim, Young C. Yim, Hye K.; Jung, Young S.; Park, Jae H.; Kim, Sung Y.

    2007-08-15

    Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ. We examined the response of the liver and kidney to chemical substances that require metabolic activation for their toxicities in mice with a preceding liver injury. Carbon tetrachloride treatment 24 h prior to a challenging dose of carbon tetrachloride or acetaminophen decreased the resulting hepatotoxicity both in male and female mice as determined by histopathological examination and increases in serum enzyme activities. In contrast, the renal toxicity of the challenging toxicants was elevated markedly in male, but not in female mice. Partial hepatectomy also induced similar changes in the hepatotoxicity and nephrotoxicity of a challenging toxicant, suggesting that the contrasting response of male liver and kidney was associated with the reduction of the hepatic metabolizing capacity. Carbon tetrachloride pretreatment or partial hepatectomy decreased the hepatic xenobiotic-metabolizing enzyme activities in both sexes but elevated the renal p-nitrophenol hydroxylase, p-nitroanisole O-demethylase and aminopyrine N-demethylase activities significantly only in male mice. Increases in Cyp2e1 and Cyp2b expression were also evident in male kidney. Castration of males or testosterone administration to females diminished the sex-related differences in the renal response to an acute liver injury. The results indicate that reduction of the hepatic metabolizing capacity induced by liver injury may render secondary target organs susceptible to chemical substances activated in these organs. This effect may be sex-specific. It is also suggested that an integrated approach should be taken for proper assessment of chemical hazards.

  8. Salacia oblonga root improves postprandial hyperlipidemia and hepatic steatosis in Zucker diabetic fatty rats: Activation of PPAR-{alpha}

    SciTech Connect

    Hsun-Wei Huang, Tom; Peng Gang; Qian Li, George; Yamahara, Johji; Roufogalis, Basil D.; Li Yuhao . E-mail: yuhao@pharm.usyd.edu.au

    2006-02-01

    Salacia oblonga (SO) root is an Ayurvedic medicine with anti-diabetic and anti-obese properties. Peroxisome proliferator-activated receptor (PPAR)-{alpha}, a nuclear receptor, plays an important role in maintaining the homeostasis of lipid metabolism. Here, we demonstrate that chronic oral administration of the water extract from the root of SO to Zucker diabetic fatty (ZDF) rats, a genetic model of type 2 diabetes and obesity, lowered plasma triglyceride and total cholesterol (TC) levels, increased plasma high-density lipoprotein levels and reduced the liver contents of triglyceride, non-esterified fatty acids (NEFA) and the ratio of fatty droplets to total tissue. By contrast, the extract had no effect on plasma triglyceride and TC levels in fasted ZDF rats. After olive oil administration to ZDF the extract also inhibited the increase in plasma triglyceride levels. These results suggest that SO extract improves postprandial hyperlipidemia and hepatic steatosis in ZDF rats. Additionally, SO treatment enhanced hepatic expression of PPAR-{alpha} mRNA and protein, and carnitine palmitoyltransferase-1 and acyl-CoA oxidase mRNAs in ZDF rats. In vitro, SO extract and its main component mangiferin activated PPAR-{alpha} luciferase activity in human embryonic kidney 293 cells and lipoprotein lipase mRNA expression and enzyme activity in THP-1 differentiated macrophages; these effects were completely suppressed by a selective PPAR-{alpha} antagonist MK-886. The findings from both in vivo and in vitro suggest that SO extract functions as a PPAR-{alpha} activator, providing a potential mechanism for improvement of postprandial hyperlipidemia and hepatic steatosis in diabetes and obesity.

  9. CD4(+) T-cell activation and induction of autoimmune hepatitis following trichloroethylene treatment in MRL+/+ mice.

    PubMed

    Griffin, J M; Gilbert, K M; Lamps, L W; Pumford, N R

    2000-10-01

    Exposure to relatively high levels of trichloroethylene has recently been shown to accelerate the development of an autoimmune response in the autoimmune prone MRL+/+ mice. The trichloroethylene-induced autoimmune response was associated with an increase in activated CD4(+) T cells, producing Th(1)-like cytokines. The present study was conducted to determine whether lower, more occupationally relevant doses of trichloroethylene could also promote autoimmunity, in MRL+/+ mice, and if so, to investigate the mechanism of this accelerated autoimmune response. In addition, histological studies were performed to determine if trichloroethylene was capable of producing pathological markers consistent with an autoimmune disease. Trichloroethylene was administered to mice in the drinking water at 0, 0.1, 0.5, and 2.5 mg/ml for 4 and 32 weeks. There was a significant increase above controls in serum antinuclear antibody (ANA) levels following 4 weeks of both 0.1 and 0.5 mg/kg/day of trichloroethylene. After 32 weeks of treatment, ANA levels were elevated and equal in all groups. The kinetics of the ANA response indicated that trichloroethylene accelerated the innate autoimmune response in the MRL+/+ mice. There was a dose-related increase in the percentage of activated CD4(+) T cells in both the spleens and lymph nodes of mice treated for 32 weeks with trichloroethylene when compared to controls. CD4(+) T cells isolated from MRL+/+ mice after either 4 or 32 weeks of treatment with trichloroethylene secreted inflammatory or Th(1)-like cytokines. Following 32 weeks of trichloroethylene treatment, there was a significant increase in hepatic mononuclear infiltration localized to the portal region, a type of hepatic infiltration consistent with autoimmune hepatitis. Taken collectively, these data suggest that exposure to occupationally relevant concentrations of trichloroethylene can accelerate an autoimmune response and can lead to autoimmune disease. The mechanism of this

  10. Potential treatment options and future research to increase hepatitis C virus treatment response rate

    PubMed Central

    TenCate, Veronica; Sainz, Bruno; Cotler, Scott J; Uprichard, Susan L

    2010-01-01

    Hepatitis C virus (HCV) is a liver-tropic blood-borne pathogen that affects more than 170 million people worldwide. Although acute infections are usually asymptomatic, up to 90% of HCV infections persist with the possibility of long-term consequences such as liver fibrosis, cirrhosis, steatosis, insulin resistance, or hepatocellular carcinoma. As such, HCV-associated liver disease is a major public health concern. Although the currently available standard of care therapy of pegylated interferon α plus ribavirin successfully treats infection in a subset of patients, the development of more effective, less toxic HCV antivirals is a health care imperative. This review not only discusses the limitations of the current HCV standard of care but also evaluates upcoming HCV treatment options and how current research elucidating the viral life cycle is facilitating the development of HCV-specific therapeutics that promise to greatly improve treatment response rates both before and after liver transplantation. PMID:21331152

  11. Potential treatment options and future research to increase hepatitis C virus treatment response rate.

    PubMed

    Tencate, Veronica; Sainz, Bruno; Cotler, Scott J; Uprichard, Susan L

    2010-10-01

    Hepatitis C virus (HCV) is a liver-tropic blood-borne pathogen that affects more than 170 million people worldwide. Although acute infections are usually asymptomatic, up to 90% of HCV infections persist with the possibility of long-term consequences such as liver fibrosis, cirrhosis, steatosis, insulin resistance, or hepatocellular carcinoma. As such, HCV-associated liver disease is a major public health concern. Although the currently available standard of care therapy of pegylated interferon α plus ribavirin successfully treats infection in a subset of patients, the development of more effective, less toxic HCV antivirals is a health care imperative. This review not only discusses the limitations of the current HCV standard of care but also evaluates upcoming HCV treatment options and how current research elucidating the viral life cycle is facilitating the development of HCV-specific therapeutics that promise to greatly improve treatment response rates both before and after liver transplantation.

  12. Detergent-induced activation of the hepatitis C virus genotype 1b RNA polymerase.

    PubMed

    Weng, Leiyun; Kohara, Michinori; Wakita, Takaji; Shimotohno, Kunitada; Toyoda, Tetsuya

    2012-04-01

    Recently, we found that sphingomyelin bound and activated hepatitis C virus (HCV) 1b RNA polymerase (RdRp), thereby recruiting the HCV replication complex into lipid raft structures. Detergents are commonly used for resolving lipids and purifying proteins, including HCV RdRp. Here, we tested the effect of detergents on HCV RdRp activity in vitro and found that non-ionic (Triton X-100, NP-40, Tween 20, Tween 80, and Brij 35) and twitterionic (CHAPS) detergents activated HCV 1b RdRps by 8-16.6 folds, but did not affect 1a or 2a RdRps. The maximum effect of these detergents was observed at around their critical micelle concentrations. On the other hand, ionic detergents (SDS and DOC) completely inactivated polymerase activity at 0.01%. In the presence of Triton X-100, HCV 1b RdRp did not form oligomers, but recruited more template RNA and increased the speed of polymerization. Comparison of polymerase and RNA-binding activity between JFH1 RdRp and Triton X-100-activated 1b RdRp indicated that monomer RdRp showed high activity because JFH1 RdRp was a monomer in physiological conditions of transcription. Besides, 502H plays a key role on oligomerization of 1b RdRp, while 2a RdRps which have the amino acid S at position 502 are monomers. This oligomer formed by 502H was disrupted both by high salt and Triton X-100. On the contrary, HCV 1b RdRp completely lost fidelity in the presence of 0.02% Triton X-100, which suggests that caution should be exercised while using Triton X-100 in anti-HCV RdRp drug screening tests.

  13. Increase in the systemic exposure of primary metabolites of Midazolam in rat arising from CYP inhibition or hepatic dysfunction.

    PubMed

    Hasegawa, Tsubasa; Nakanishi, Satomi; Minami, Keiko; Higashino, Haruki; Kataoka, Makoto; Shitara, Yoshihisa; Yamashita, Shinji

    2017-02-01

    The main purpose of this study is to demonstrate the possibility of increase in the systemic exposure of drug metabolites by CYP-inhibition or acute hepatitis. Midazolam (MDZ) was used as a model substrate of CYP3A and 1-aminobenzotriazole (ABT) was used as a CYP-inhibitor. After oral pretreatment with ABT, MDZ was intravenously injected to rats and the plasma profiles of MDZ and its primary metabolites, 1'-hydroxy MDZ and 4-hydroxy MDZ, were observed. In the ABT-pretreatment rats, plasma AUCs of both metabolites were much larger than those in control rats, demonstrating a higher systemic exposure of metabolites under CYP-inhibited condition. Furthermore, kinetic analysis revealed that the amount of both metabolites entered into the systemic circulation increased significantly (about 5-times). Increases in the systemic exposure of the primary metabolites of MDZ were also observed in the acute hepatitis rats induced by CCl4-pretreatment. As underlying mechanisms, it was speculated that ABT inhibited the subsequent metabolism of primary metabolites of MDZ in the hepatocytes and enhanced their release to the systemic circulation. In vitro study with rat liver microsomes supported this speculation. In conclusion, this study showed the complexity of PK profiles of drug metabolites, which might lead to new aspects on their safety issue.

  14. Dietary Betaine Supplementation Increases Fgf21 Levels to Improve Glucose Homeostasis and Reduce Hepatic Lipid Accumulation in Mice

    PubMed Central

    Ejaz, Asma; Martinez-Guino, Laura; Goldfine, Allison B.; Ribas-Aulinas, Francesc; De Nigris, Valeria; Ribó, Sílvia; Gonzalez-Franquesa, Alba; Garcia-Roves, Pablo M.; Li, Elizabeth; Dreyfuss, Jonathan M.; Gall, Walt; Kim, Jason K.; Bottiglieri, Teodoro; Villarroya, Francesc; Gerszten, Robert E.

    2016-01-01

    Identifying markers of human insulin resistance may permit development of new approaches for treatment and prevention of type 2 diabetes. To this end, we analyzed the fasting plasma metabolome in metabolically characterized human volunteers across a spectrum of insulin resistance. We demonstrate that plasma betaine levels are reduced in insulin-resistant humans and correlate closely with insulin sensitivity. Moreover, betaine administration to mice with diet-induced obesity prevents the development of impaired glucose homeostasis, reduces hepatic lipid accumulation, increases white adipose oxidative capacity, and enhances whole-body energy expenditure. In parallel with these beneficial metabolic effects, betaine supplementation robustly increased hepatic and circulating fibroblast growth factor (Fgf)21 levels. Betaine administration failed to improve glucose homeostasis and liver fat content in Fgf21−/− mice, demonstrating that Fgf21 is necessary for betaine’s beneficial effects. Together, these data indicate that dietary betaine increases Fgf21 levels to improve metabolic health in mice and suggest that betaine supplementation merits further investigation as a supplement for treatment or prevention of type 2 diabetes in humans. PMID:26858359

  15. Brain glucagon-like peptide–1 increases insulin secretion and muscle insulin resistance to favor hepatic glycogen storage

    PubMed Central

    Knauf, Claude; Cani, Patrice D.; Perrin, Christophe; Iglesias, Miguel A.; Maury, Jean François; Bernard, Elodie; Benhamed, Fadilha; Grémeaux, Thierry; Drucker, Daniel J.; Kahn, C. Ronald; Girard, Jean; Tanti, Jean François; Delzenne, Nathalie M.; Postic, Catherine; Burcelin, Rémy

    2005-01-01

    Intestinal glucagon-like peptide–1 (GLP-1) is a hormone released into the hepatoportal circulation that stimulates pancreatic insulin secretion. GLP-1 also acts as a neuropeptide to control food intake and cardiovascular functions, but its neural role in glucose homeostasis is unknown. We show that brain GLP-1 controlled whole-body glucose fate during hyperglycemic conditions. In mice undergoing a hyperglycemic hyperinsulinemic clamp, icv administration of the specific GLP-1 receptor antagonist exendin 9–39 (Ex9) increased muscle glucose utilization and glycogen content. This effect did not require muscle insulin action, as it also occurred in muscle insulin receptor KO mice. Conversely, icv infusion of the GLP-1 receptor agonist exendin 4 (Ex4) reduced insulin-stimulated muscle glucose utilization. In hyperglycemia achieved by i.v. infusion of glucose, icv Ex4, but not Ex9, caused a 4-fold increase in insulin secretion and enhanced liver glycogen storage. However, when glucose was infused intragastrically, icv Ex9 infusion lowered insulin secretion and hepatic glycogen levels, whereas no effects of icv Ex4 were observed. In diabetic mice fed a high-fat diet, a 1-month chronic i.p. Ex9 treatment improved glucose tolerance and fasting glycemia. Our data show that during hyperglycemia, brain GLP-1 inhibited muscle glucose utilization and increased insulin secretion to favor hepatic glycogen stores, preparing efficiently for the next fasting state. PMID:16322793

  16. Increased hepatic CD36 expression with age is associated with enhanced susceptibility to nonalcoholic fatty liver disease

    PubMed Central

    Sheedfar, Fareeba; Sung, Miranda MY; Aparicio-Vergara, Marcela; Kloosterhuis, Niels J; Miquilena-Colina, Maria Eugenia; Vargas-Castrillón, Javier; Febbraio, Maria; Jacobs, René L; de Bruin, Alain; Vinciguerra, Manlio; García-Monzón, Carmelo; Hofker, Marten H; Dyck, Jason RB; Koonen, Debby PY

    2014-01-01

    CD36 has been associated with obesity and diabetes in human liver diseases, however, its role in age-associated nonalcoholic fatty liver disease (NAFLD) is unknown. Therefore, liver biopsies were collected from individuals with histologically normal livers (n=30), and from patients diagnosed with simple steatosis (NAS; n=26). Patients were divided into two groups according to age and liver biopsy samples were immunostained for CD36. NAFLD parameters were examined in young (12-week) and middle-aged (52-week) C57BL/6J mice, some fed with chow-diet and some fed with low-fat (LFD; 10% kcal fat) or high-fat diet (HFD; 60% kcal fat) for 12-weeks. CD36 expression was positively associated with age in individuals with normal livers but not in NAS patients. However, CD36 was predominantly located at the plasma membrane of hepatocytes in aged NAS patients as compared to young. In chow-fed mice, aging, despite an increase in hepatic CD36 expression, was not associated with the development of NAFLD. However, middle-aged mice did exhibit the development of HFD-induced NAFLD, mediated by an increase of CD36 on the membrane. Enhanced CD36-mediated hepatic fat uptake may contribute to an accelerated progression of NAFLD in mice and humans. Therapies to prevent the increase in CD36 expression and/or CD36 from anchoring at the membrane may prevent the development of NAFLD. PMID:24751397

  17. Brain glucagon-like peptide-1 increases insulin secretion and muscle insulin resistance to favor hepatic glycogen storage.

    PubMed

    Knauf, Claude; Cani, Patrice D; Perrin, Christophe; Iglesias, Miguel A; Maury, Jean François; Bernard, Elodie; Benhamed, Fadilha; Grémeaux, Thierry; Drucker, Daniel J; Kahn, C Ronald; Girard, Jean; Tanti, Jean François; Delzenne, Nathalie M; Postic, Catherine; Burcelin, Rémy

    2005-12-01

    Intestinal glucagon-like peptide-1 (GLP-1) is a hormone released into the hepatoportal circulation that stimulates pancreatic insulin secretion. GLP-1 also acts as a neuropeptide to control food intake and cardiovascular functions, but its neural role in glucose homeostasis is unknown. We show that brain GLP-1 controlled whole-body glucose fate during hyperglycemic conditions. In mice undergoing a hyperglycemic hyperinsulinemic clamp, icv administration of the specific GLP-1 receptor antagonist exendin 9-39 (Ex9) increased muscle glucose utilization and glycogen content. This effect did not require muscle insulin action, as it also occurred in muscle insulin receptor KO mice. Conversely, icv infusion of the GLP-1 receptor agonist exendin 4 (Ex4) reduced insulin-stimulated muscle glucose utilization. In hyperglycemia achieved by i.v. infusion of glucose, icv Ex4, but not Ex9, caused a 4-fold increase in insulin secretion and enhanced liver glycogen storage. However, when glucose was infused intragastrically, icv Ex9 infusion lowered insulin secretion and hepatic glycogen levels, whereas no effects of icv Ex4 were observed. In diabetic mice fed a high-fat diet, a 1-month chronic i.p. Ex9 treatment improved glucose tolerance and fasting glycemia. Our data show that during hyperglycemia, brain GLP-1 inhibited muscle glucose utilization and increased insulin secretion to favor hepatic glycogen stores, preparing efficiently for the next fasting state.

  18. Increased ABCA1 activity protects against atherosclerosis.

    PubMed

    Singaraja, Roshni R; Fievet, Catherine; Castro, Graciela; James, Erick R; Hennuyer, Nathalie; Clee, Susanne M; Bissada, Nagat; Choy, Jonathan C; Fruchart, Jean-Charles; McManus, Bruce M; Staels, Bart; Hayden, Michael R

    2002-07-01

    The ABC transporter ABCA1 plays a key role in the first steps of the reverse cholesterol transport pathway by mediating lipid efflux from macrophages. Previously, it was demonstrated that human ABCA1 overexpression in vivo in transgenic mice results in a mild elevation of plasma HDL levels and increased efflux of cholesterol from macrophages. In this study, we determined the effect of overexpression of ABCA1 on atherosclerosis development. Human ABCA1 transgenic mice (BAC(+)) were crossed with ApoE(-/-) mice, a strain that spontaneously develop atherosclerotic lesions. BAC(+)ApoE(-/-) mice developed dramatically smaller, less-complex lesions as compared with their ApoE(-/-) counterparts. In addition, there was increased efflux of cholesterol from macrophages isolated from the BAC(+)ApoE(-/-) mice. Although the increase in plasma HDL cholesterol levels was small, HDL particles from BAC(+)ApoE(-/-) mice were significantly better acceptors of cholesterol. Lipid analysis of HDL particles from BAC(+)ApoE(-/-) mice revealed an increase in phospholipid levels, which was correlated significantly with their ability to enhance cholesterol efflux.

  19. beta. -adrenergic receptor-mediated hepatic glycogenolysis is increased in aged male rats

    SciTech Connect

    Herring, P.A.; Graham, S.M.; Arinze, I.J.

    1986-03-05

    The effect of age on catecholamine-stimulated glycogenolysis was studied in isolated hepatocytes prepared from 3, 12, and 24 month-old rats. Glucose release was stimulated by epinephrine and norepinephrine, this was inhibited by phentolamine and prazosin. Isoproterenol (ISO) stimulated glycogenolysis only in cells from 24 month-old rats, this was blocked by propranolol. In liver plasma membranes, binding of (/sup 3/H)yohimbine (100-130 fmol/mg protein) did not change with age, whereas (/sup 3/H)prazosin binding decreased from 870 fmol/mg at 3 months to 435 fmol/mg at 12 months, but subsequently rose to 656 fmol/mg at 24 months. (/sup 125/I)Cyanopindolol binding increased from 8 fmol/mg at 3 months to 19 fmol/mg at 24 months. The proportion of ..beta..-receptors in the high affinity state increased from 28% at 3 months to 42% at 24 months. ISO stimulated adenylate cyclase at 24 months but not at 3 months. Basal, fluoride-, GTP-, and Gpp(NH)p-stimulated activities were 1.4- to 2.4-fold greater at 24 months than at 3 months. These results suggest an age-related increase in the sensitivity of adenylate cyclase to ..beta..-receptor stimulation.

  20. 17β-Estradiol protects against acetaminophen-overdose-induced acute oxidative hepatic damage and increases the survival rate in mice.

    PubMed

    Chandrasekaran, Victor Raj Mohan; Periasamy, Srinivasan; Liu, Li-Lian; Liu, Ming-Yie

    2011-01-01

    Acetaminophen overdose causes acute liver injury or even death in both humans and experimental animals. We investigated the effect of 17β-estradiol against acetaminophen-induced acute liver injury and mortality in mice. Male mice were given acetaminophen (p-acetamidophenol; 300 mg/kg; orally) to induce acute liver injury. Acetaminophen significantly increased the levels of aspartate transaminase, alanine transaminase, myeloperoxidase, lipid peroxidation, and glutathione reductase, but it decreased superoxide dismutase, catalase, and glutathione. In addition, acetaminophen-induced mortality began 4h post-treatment, and all mice died within 9h. 17β-Estradiol (200 μg/kg; i.p.) protected against acetaminophen-induced oxidative hepatic damage by inhibiting neutrophil infiltration and stimulating the antioxidant defense system. However, 17β-estradiol did not affect acetaminophen-induced glutathione depletion or increased glutathione reductase activity. We conclude that 17β-estradiol specifically attenuates acute hepatic damage and decreases mortality in acetaminophen-overdosed male mice.

  1. Therapeutic insulin and hepatic glucose-6-phosphatase activity in preterm infants

    PubMed Central

    Burchell, A; McGeechan, A; Hume, R

    2000-01-01

    BACKGROUND—Hepatic glucose-6-phosphatase activity is low at birth, and in term infants rises rapidly to adult levels. In contrast, in most preterm infants, it remains low postnatally making them vulnerable to repeated hypoglycaemic episodes, resultant cerebral damage, or risk of sudden and unexpected death.
AIMS—To investigate the clinical features of preterm infants with low glucose-6-phosphatase enzyme activity to determine the influencing factors.
METHODS—Clinical data from 36 preterm infants were correlated by stepwise multiple regression analysis with Vmax of hepatic glucose-6-phosphatase as the dependent variable.
RESULTS—The most significant correlation was with the administration of insulin (units/kg/h postnatal life) with lesser effects of respiratory distress syndrome and dopamine administration. The Vmax changes reflected changes in the level of expression of the glucose-6-phosphatase protein.
CONCLUSION—In a variety of animal models, hepatic glucose-6-phosphatase levels have been shown to decrease in response to insulin, which also decreases transcription of the glucose-6-phosphatase gene. The association of insulin administration with high levels of hepatic glucose-6-phosphatase activity and protein expression was therefore most unexpected. Results from model systems, or adults, must be extrapolated to the metabolism of preterm infants with caution.

 PMID:10794792

  2. Activation of PPARγ/P53 signaling is required for curcumin to induce hepatic stellate cell senescence

    PubMed Central

    Jin, H; Lian, N; Zhang, F; Chen, L; Chen, Q; Lu, C; Bian, M; Shao, J; Wu, L; Zheng, S

    2016-01-01

    Activation of quiescent hepatic stellate cells (HSCs) is the major event in hepatic fibrogenesis, along with enhancement of cell proliferation and overproduction of extracellular matrix. Although inhibition of cell proliferation and induction of apoptosis are potential strategies to block the activation of HSCs, a better understanding of the senescence of activated HSCs can provide a new therapeutic strategy for prevention and treatment of liver fibrosis. The antioxidant curcumin, a phytochemical from turmeric, has been shown to suppress HSC activation in vitro and in vivo. The current work was aimed to evaluate the effect of curcumin on senescence of activated HSCs and to elucidate the underlying mechanisms. In this study, curcumin promoted the expression of senescence marker Hmga1 in rat fibrotic liver. In addition, curcumin increased the number of senescence-associated β-galactosidase-positive HSCs in vitro. At the same time, curcumin induced HSC senescence by elevating the expression of senescence markers P16, P21 and Hmga1, concomitant with reduced abundance of HSC activation markers α-smooth muscle actin and α1(I)-procollagen in cultured HSCs. Moreover, curcumin affected the cell cycle and telomerase activity. We further demonstrated that P53 pharmacological inhibitor pifithrin-α (PFT-α) or transfection with P53 siRNA abrogated the curcumin-induced HSC senescence in vitro. Meanwhile, curcumin disruption of P53 leading to increased senescence of activated HSCs was further verified in vivo. Further studies indicated that curcumin promoted the expression of P53 through a PPARγ activation-dependent mechanism. Moreover, promoting PPARγ transactivating activity by a PPARγ agonist 15d-PGJ2 markedly enhanced curcumin induction of senescence of activated HSCs. However, the PPARγ antagonist PD68235 eliminated curcumin induction of HSC senescence. Taken together, our results provided a novel insight into the mechanisms underlying curcumin inhibition of HSC

  3. AMPK antagonizes hepatic glucagon-stimulated cyclic AMP signalling via phosphorylation-induced activation of cyclic nucleotide phosphodiesterase 4B

    PubMed Central

    Johanns, M.; Lai, Y.-C.; Hsu, M.-F.; Jacobs, R.; Vertommen, D.; Van Sande, J.; Dumont, J. E.; Woods, A.; Carling, D.; Hue, L.; Viollet, B.; Foretz, M; Rider, M H

    2016-01-01

    Biguanides such as metformin have previously been shown to antagonize hepatic glucagon-stimulated cyclic AMP (cAMP) signalling independently of AMP-activated protein kinase (AMPK) via direct inhibition of adenylate cyclase by AMP. Here we show that incubation of hepatocytes with the small-molecule AMPK activator 991 decreases glucagon-stimulated cAMP accumulation, cAMP-dependent protein kinase (PKA) activity and downstream PKA target phosphorylation. Moreover, incubation of hepatocytes with 991 increases the Vmax of cyclic nucleotide phosphodiesterase 4B (PDE4B) without affecting intracellular adenine nucleotide concentrations. The effects of 991 to decrease glucagon-stimulated cAMP concentrations and activate PDE4B are lost in hepatocytes deleted for both catalytic subunits of AMPK. PDE4B is phosphorylated by AMPK at three sites, and by site-directed mutagenesis, Ser304 phosphorylation is important for activation. In conclusion, we provide a new mechanism by which AMPK antagonizes hepatic glucagon signalling via phosphorylation-induced PDE4B activation. PMID:26952277

  4. Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity.

    PubMed

    El-Mansy, A A; Mazroa, S A; Hamed, W S; Yaseen, A H; El-Mohandes, E A

    2016-01-01

    The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.

  5. Ionone Derivatives from the Mycelium of Phellinus linteus and the Inhibitory Effect on Activated Rat Hepatic Stellate Cells

    PubMed Central

    Huang, Shiow-Chyn; Kuo, Ping-Chung; Hung, Hsin-Yi; Pan, Tai-Long; Chen, Fu-An; Wu, Tian-Shung

    2016-01-01

    Three new γ-ionylideneacetic acid derivatives, phellinulins A–C (1–3), were characterized from the mycelium extract of Phellinus linteus. The chemical structures were established based on the spectroscopic analysis. In addition, phellinulin A (1) was subjected to the examination of effects on activated rat hepatic stellate cells and exhibited significant inhibition of hepatic fibrosis. PMID:27164091

  6. Lessons to be learned: a case study approach: severe hyponatraemia induced by primary hypothyroidism and associated with possible increased hepatic sensitivity to thyroxine replacement.

    PubMed

    Olukoga, A; Horsman, G; Stewart, F

    1999-06-01

    The case is presented of a 74 year-old woman who was admitted with severe hypo-osmolar hyponatraemia associated with inappropriately raised urinary osmolality, and who was subsequently discovered to have primary hypothyroidism. A normal serum sodium concentration was restored by means of judicious fluid restriction and thyroid hormone replacement. Low dose thyroxine therapy led to rapid but modest increases in the serum activities of alanine aminotransferase (ALT) and alkaline phosphatase (ALP); both returned to normal over a period of three weeks. These sub-clinical enzyme changes may indicate tissue 'hyperthyroidism'; and in this case, the fact that they occurred acutely at only low doses of thyroxine possibly suggests an increased hepatic sensitivity to the hormone.

  7. Chronic hepatitis C infection–induced liver fibrogenesis is associated with M2 macrophage activation

    PubMed Central

    Bility, Moses T.; Nio, Kouki; Li, Feng; McGivern, David R.; Lemon, Stanley M.; Feeney, Eoin R.; Chung, Raymond T.; Su, Lishan

    2016-01-01

    The immuno-pathogenic mechanisms of chronic hepatitis C virus (HCV) infection remain to be elucidated and pose a major hurdle in treating or preventing chronic HCV-induced advanced liver diseases such as cirrhosis. Macrophages are a major component of the inflammatory milieu in chronic HCV–induced liver disease, and are generally derived from circulating inflammatory monocytes; however very little is known about their role in liver diseases. To investigate the activation and role of macrophages in chronic HCV–induced liver fibrosis, we utilized a recently developed humanized mouse model with autologous human immune and liver cells, human liver and blood samples and cell culture models of monocyte/macrophage and/or hepatic stellate cell activation. We showed that M2 macrophage activation was associated with liver fibrosis during chronic HCV infection in the livers of both humanized mice and patients, and direct-acting antiviral therapy attenuated M2 macrophage activation and associated liver fibrosis. We demonstrated that supernatant from HCV-infected liver cells activated human monocytes/macrophages with M2-like phenotypes. Importantly, HCV-activated monocytes/macrophages promoted hepatic stellate cell activation. These results suggest a critical role for M2 macrophage induction in chronic HCV-associated immune dysregulation and liver fibrosis. PMID:28000758

  8. Chronic hepatitis C infection-induced liver fibrogenesis is associated with M2 macrophage activation.

    PubMed

    Bility, Moses T; Nio, Kouki; Li, Feng; McGivern, David R; Lemon, Stanley M; Feeney, Eoin R; Chung, Raymond T; Su, Lishan

    2016-12-21

    The immuno-pathogenic mechanisms of chronic hepatitis C virus (HCV) infection remain to be elucidated and pose a major hurdle in treating or preventing chronic HCV-induced advanced liver diseases such as cirrhosis. Macrophages are a major component of the inflammatory milieu in chronic HCV-induced liver disease, and are generally derived from circulating inflammatory monocytes; however very little is known about their role in liver diseases. To investigate the activation and role of macrophages in chronic HCV-induced liver fibrosis, we utilized a recently developed humanized mouse model with autologous human immune and liver cells, human liver and blood samples and cell culture models of monocyte/macrophage and/or hepatic stellate cell activation. We showed that M2 macrophage activation was associated with liver fibrosis during chronic HCV infection in the livers of both humanized mice and patients, and direct-acting antiviral therapy attenuated M2 macrophage activation and associated liver fibrosis. We demonstrated that supernatant from HCV-infected liver cells activated human monocytes/macrophages with M2-like phenotypes. Importantly, HCV-activated monocytes/macrophages promoted hepatic stellate cell activation. These results suggest a critical role for M2 macrophage induction in chronic HCV-associated immune dysregulation and liver fibrosis.

  9. Trace element analysis by PIXE in liver samples from dogs with chronic active hepatitis and liver cirrhosis

    NASA Astrophysics Data System (ADS)

    Andersson, Marianne; Ekholm, Ann-Kristin; Sevelius, Ewa

    1990-04-01

    Trace element levels of liver samples obtained from necropsied dogs suffering from hepatitis and/or liver cirrhosis were determined by PIXE. Two different techniques for preparation of the samples were compared: the pellet press method and wet digestion. Both methods gave similar results, but the pellet press method was chosen for the subsequent routine analyses because of its simplicity due to few preparation steps and little risk of contamination. Preliminary results indicate elevated levels of Cu in chronic hepatitis and cirrhosis. In hereditary copper-induced hepatitis (Bedlington hepatitis) Fe and Br levels were increased as well.

  10. Involvement of AMP-activated protein kinase in beneficial effects of betaine on high-sucrose diet-induced hepatic steatosis.

    PubMed

    Song, Zhenyuan; Deaciuc, Ion; Zhou, Zhanxiang; Song, Ming; Chen, Theresa; Hill, Daniell; McClain, Craig J

    2007-10-01

    Although simple steatosis was originally thought to be a pathologically inert histological change, fat accumulation in the liver may play a critical role not only in disease initiation, but also in the progression to nonalcoholic steatohepatitis and cirrhosis. Therefore, prevention of fat accumulation in the liver may be an effective therapy for multiple stages of nonalcoholic fatty liver disease (NAFLD). Promising beneficial effects of betaine supplementation on human NAFLD have been reported in some pilot clinical studies; however, data related to betaine therapy in NAFLD are limited. In this study, we examined the effects of betaine on fat accumulation in the liver induced by high-sucrose diet and evaluated mechanisms by which betaine could attenuate or prevent hepatic steatosis in this model. Male C57BL/6 mice weighing 20 +/- 0.5 g (means +/- SE) were divided into four groups (8 mice per group) and started on one of four treatments: standard diet (SD), SD+betaine, high-sucrose diet (HS), and HS + betaine. Betaine was supplemented in the drinking water at a concentration of 1% (wt/vol) (anhydrous). Long-term feeding of high-sucrose diet to mice caused significant hepatic steatosis accompanied by markedly increased lipogenic activity. Betaine significantly attenuated hepatic steatosis in this animal model, and this change was associated with increased activation of hepatic AMP-activated protein kinase (AMPK) and attenuated lipogenic capability (enzyme activities and gene expression) in the liver. Our findings are the first to suggest that betaine might serve as a therapeutic tool to attenuate hepatic steatosis by targeting the hepatic AMPK system.

  11. Suberoylanilide hydroxamic acid suppresses hepatic stellate cells activation by HMGB1 dependent reduction of NF-κB1

    PubMed Central

    Wang, Wenwen; Yan, Min; Ji, Qiuhong; Lu, Jinbiao; Ji, Yuhua

    2015-01-01

    Hepatic stellate cells (HSCs) activation is essential to the pathogenesis of liver fibrosis. Exploring drugs targeting HSC activation is a promising anti-fibrotic strategy. In the present study, we found suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, prominently suppressed the activation phenotype of a human hepatic stellate cell line—LX2. The production of collagen type I and α-smooth muscle actin (α-SMA) as well as the proliferation and migration of LX2 cells were significantly reduced by SAHA treatment. To determine the molecular mechanisms underlying this suppression, genome wild gene regulation by SAHA was determined by Affymetrix 1.0 human cDNA array. Upon SAHA treatment, the abundance of 331 genes was up-regulated and 173 genes was down-regulated in LX2 cells. Bioinformatic analyses of these altered genes highlighted the high mobility group box 1 (HMGB1) pathway was one of the most relevant pathways that contributed to SAHA induced suppression of HSCs activation. Further studies demonstrated the increased acetylation of intracellular HMGB1 in SAHA treated HSCs, and this increasing is most likely to be responsible for SAHA induced down-regulation of nuclear factor kappa B1 (NF-κB1) and is one of the main underlying mechanisms for the therapeutic effect of SAHA for liver fibrosis. PMID:26557438

  12. Obesity resistance and increased hepatic expression of catabolism-related mRNAs in Cnot3+/− mice

    PubMed Central

    Morita, Masahiro; Oike, Yuichi; Nagashima, Takeshi; Kadomatsu, Tsuyoshi; Tabata, Mitsuhisa; Suzuki, Toru; Nakamura, Takahisa; Yoshida, Nobuaki; Okada, Mariko; Yamamoto, Tadashi

    2011-01-01

    Obesity is a life-threatening factor and is often associated with dysregulation of gene expression. Here, we show that the CNOT3 subunit of the CCR4–NOT deadenylase complex is critical to metabolic regulation. Cnot3+/− mice are lean with hepatic and adipose tissues containing reduced levels of lipids, and show increased metabolic rates and enhanced glucose tolerance. Cnot3+/− mice remain lean and sensitive to insulin even on a high-fat diet. Furthermore, introduction of Cnot3 haplodeficiency in ob/ob mice ameliorated the obese phenotype. Hepatic expression of most mRNAs is not altered in Cnot3+/− vis-à-vis wild-type mice. However, the levels of specific mRNAs, such as those coding for energy metabolism-related PDK4 and IGFBP1, are increased in Cnot3+/− hepatocytes, having poly(A) tails that are longer than those seen in control cells. We provide evidence that CNOT3 is involved in recruitment of the CCR4–NOT deadenylase to the 3′ end of specific mRNAs. Finally, as CNOT3 levels in the liver and white adipose tissues decrease upon fasting, we propose that CNOT3 responds to feeding conditions to regulate deadenylation-specific mRNAs and energy metabolism. PMID:21897366

  13. An oxygenated metabolite of benzo[a]pyrene increases hepatic β-oxidation of fatty acids in chick embryos.

    PubMed

    Westman, Ola; Larsson, Maria; Venizelos, Nikolaos; Hollert, Henner; Engwall, Magnus

    2014-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are well-known carcinogens to humans and ecotoxicological effects have been shown in several studies. However, PAHs can also be oxidized into more water soluble-oxygenated metabolites (Oxy-PAHs). The first purpose of the present project was to (1) assess the effects of a mixture containing three parent PAHs: anthracene, benz[a]anthracene, and benzo[a]pyrene versus a mixture of their oxygenated metabolites, namely: anthracene-9,10-dione, benz[a]anthracene-7,12-dione, and 9,10-dihydrobenzo[a]pyrene-7-(8H)-one on the hepatic fatty acid β-oxidation in chicken embryos (Gallus gallus domesticus) exposed in ovo. The second and also main purpose of the project was to (2) assess the effects of the parent PAHs versus their oxy-PAHs analogues when injected individually, followed by (3) additional testing of the individual oxy-PAHs. The hepatic β-oxidation was measured using a tritium release assay with [9,10-(3)H]-palmitic acid (16:0) as substrate. The result from the first part (1) showed reduced hepatic β-oxidation after exposure in ovo to a mixture of three PAHs, however, increased after exposure to the mixture of three oxy-PAHs compared to control. The result from the second part (2) and also the follow-up experiment (3) showed that 9,10-dihydrobenzo[a]pyrene-7-(8H)-one was the causative oxy-PAH. The implication of this finding on the risk assessment of PAH metabolite exposure in avian wildlife remains to be determined. To the best of our knowledge, no similar studies have been reported.

  14. Peroxisome proliferator-activated receptor alpha controls hepatic heme biosynthesis through ALAS1.

    PubMed

    Degenhardt, Tatjana; Väisänen, Sami; Rakhshandehroo, Maryam; Kersten, Sander; Carlberg, Carsten

    2009-05-01

    Heme is an essential prosthetic group of proteins involved in oxygen transport, energy metabolism and nitric oxide production. ALAS1 (5-aminolevulinate synthase) is the rate-limiting enzyme in heme synthesis in the liver and is highly regulated to adapt to the metabolic demand of the hepatocyte. In the present study, we describe human hepatic ALAS1 as a new direct target for the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha). In primary human hepatocytes and in HepG2 cells, PPARalpha agonists induced an increase in ALAS1 mRNA levels, which was abolished by PPARalpha silencing. These effects are mediated by two functional PPAR binding sites at positions -9 and -2.3 kb relative to the ALAS1 transcription start site. PPARalpha ligand treatment also up-regulated the mRNA levels of the genes ALAD (5-aminolevulinate dehydratase), UROS (uroporphyrinogen III synthase), UROD (uroporphyrinogen decarboxylase), CPOX (coproporphyrinogen oxidase) and PPOX (protoporphyrinogen oxidase) encoding for enzymes controlling further steps in heme biosynthesis. In HepG2 cells treated with PPARalpha agonists and in mouse liver upon fasting, the association of PPARalpha, its partner retinoid X receptor, PPARgamma co-activator 1alpha and activated RNA polymerase II with the transcription start site region of all six genes was increased, leading to higher levels of the metabolite heme. In conclusion, these data strongly support a role of PPARalpha in the regulation of human ALAS1 and of five additional genes of the pathway, consequently leading to increased heme synthesis.

  15. Amphiregulin activates human hepatic stellate cells and is upregulated in non alcoholic steatohepatitis

    PubMed Central

    McKee, Chad; Sigala, Barbara; Soeda, Junpei; Mouralidarane, Angelina; Morgan, Maelle; Mazzoccoli, Gianluigi; Rappa, Francesca; Cappello, Francesco; Cabibi, Daniela; Pazienza, Valerio; Selden, Claire; Roskams, Tania; Vinciguerra, Manlio; Oben, Jude A.

    2015-01-01

    Amphiregulin (AR) involvement in liver fibrogenesis and hepatic stellate cells (HSC) regulation is under study. Non-alcoholic fatty liver disease (NAFLD) and its more severe form non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular cancer (HCC). Our aim was to investigate ex vivo the effect of AR on human primary HSC (hHSC) and verify in vivo the relevance of AR in NAFLD fibrogenesis. hHSC isolated from healthy liver segments were analyzed for expression of AR and its activator, TNF-α converting enzyme (TACE). AR induction of hHSC proliferation and matrix production was estimated in the presence of antagonists. AR involvement in fibrogenesis was also assessed in a mouse model of NASH and in humans with NASH. hHSC time dependently expressed AR and TACE. AR increased hHSC proliferation through several mitogenic signaling pathways such as EGFR, PI3K and p38. AR also induced marked upregulation of hHSC fibrogenic markers and reduced hHSC death. AR expression was enhanced in the HSC of a murine model of NASH and of severe human NASH. In conclusion, AR induces hHSC fibrogenic activity via multiple mitogenic signaling pathways, and is upregulated in murine and human NASH, suggesting that AR antagonists may be clinically useful anti-fibrotics in NAFLD. PMID:25744849

  16. Delivery of methoxymorpholinyl doxorubicin by interleukin 2-activated NK cells: effect in mice bearing hepatic metastases

    PubMed Central

    Quintieri, L; Rosato, A; Amboldi, N; Vizler, C; Ballinari, D; Zanovello, P; Collavo, D

    1999-01-01

    The possibility of using interleukin 2 (IL-2)-activated natural killer cells (A-NK) to carry methoxymorpholinyl doxorubicin (MMDX; PNU 152243) to liver-infiltrating tumours was explored in mice bearing 2-day established M5076 reticulum cell sarcoma hepatic metastases. In vitro, MMDX was 5.5-fold more potent than doxorubicin against M5076 tumour cells. MMDX uptake by A-NK cells correlated linearly with drug concentration in the incubation medium [correlation coefficient (r) = 0.999]; furthermore, as MMDX incorporation was readily reproducible in different experiments, the amount of drug delivered by A-NK cells could be modulated. In vivo experiments showed that intravenous (i.v.) injection of MMDX-loaded A-NK cells exerted a greater therapeutic effect than equivalent or even higher doses of free drug. The increase in lifespan (ILS) following A-NK cell delivery of 53 μg kg−1 MMDX, a dosage that is ineffective when administered in free form, was similar to that observed in response to 92 μg kg−1 free drug, a dosage close to the 10% lethal dose (ILS 42% vs. 38% respectively). These results correlated with pharmacokinetic studies showing that MMDX encapsulation in A-NK cells strongly modifies its organ distribution and targets it to tissues in which IL-2 activated lymphocytes are preferentially entrapped after i.v. injection. © 1999 Cancer Research Campaign PMID:10098738

  17. Eastern region represents a worrying cluster of active hepatitis C in Algeria in 2012.

    PubMed

    Bensalem, Aïcha; Selmani, Karima; Hihi, Narjes; Bencherifa, Nesrine; Mostefaoui, Fatma; Kerioui, Cherif; Pineau, Pascal; Debzi, Nabil; Berkane, Saadi

    2016-08-01

    Algeria is the largest country of Africa, peopled with populations living a range of traditional/rural and modern/urban lifestyles. The variations of prevalence of chronic active hepatitis care poorly known on the Algerian territory. We conducted a retrospective survey on all patients (n = 998) referred to our institution in 2012 and confirmed by us for an active hepatitis C. Half of the hepatitis C virus (HCV) isolates were genotyped. Forty Algerian regions out of the 48 were represented in our study. Three geographical clusters (Aïn-Temouchent/SidiBelAbbes, Algiers, and a large Eastern region) with an excess of active hepatitis C were observed. Patients coming from the Eastern cluster (Batna, Khenchela, Oum el Bouaghi, and Tebessa) were strongly over-represented (49% of cases, OR = 14.5, P < 0.0001). The hallmarks of Eastern region were an excess of women (65% vs. 46% in the remaining population, P < 0.0001) and the almost exclusive presence of HCV genotype 1 (93% vs. 63%, P = 0.0001). The core of the epidemics was apparently located in Khenchela (odds ratio = 24.6, P < 0.0001). This situation is plausibly connected with nosocomial transmission or traditional practices as scarification (Hijama), piercing or tattooing, very lively in this region. Distinct hepatitis C epidemics are currently affecting Algerian population. The most worrying situation is observed in rural regions located east of Algeria. J. Med. Virol. 88:1394-1403, 2016. © 2016 Wiley Periodicals, Inc.

  18. Effects of thyroid hormone (thyroxine) and testosterone on hepatic 11beta-hydroxysteroid dehydrogenase mRNA and activity in pubertal hypothyroid male rats.

    PubMed

    Liu, Y J; Nakagawa, Y; Toya, K; Saegusa, H; Nasuda, K; Endoh, A; Ohzeki, T

    1998-04-01

    To investigate the effects of thyroid hormone and testosterone on 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), we measured changes in hepatic 11beta-dehydrogenase activity and its mRNA levels in pubertal methimazole (MMI)-induced hypothyroid male rats following treatment with thyroxine ([T4] 50 microg/kg/d) or testosterone (250 microg/d) for 14 days. Hypothyroidism in male rats markedly reduced hepatic 11beta-HSD1 mRNA levels and serum testosterone concentrations (P < .01). Subcutaneous injection of T4 in the hypothyroid rats significantly (P < .01) increased hepatic 11beta-HSD1 mRNA to approximately normal levels and simultaneously increased serum testosterone levels. However, the same daily dose of T4 administered to castrated male hypothyroid rats for 14 days did not elevate hepatic 11beta-HSD1 activity. Treatment with testosterone for 14 days in castrated hypothyroid male rats and rats without gonadectomy significantly (P < .01) increased the enzyme activity without administration of T4. Variations in hepatic 11beta-HSD1 activity were demonstrated to be accompanied by changes in serum testosterone levels in the rats following alteration of the thyroid hormone state. These results suggest that the effect of T4 in increasing the subnormal 11beta-HSD1 gene expression in hypothyroid male rats is mediated by its ability to increase testosterone production in these rats, because in castrated hypothyroid rats, T4 does not elevate 11beta-HSD1 gene expression.

  19. Hepatitis C virus non-structural protein-2 activates CXCL-8 transcription through NF-kappaB.

    PubMed

    Oem, J-K; Jackel-Cram, C; Li, Y-P; Kang, H-N; Zhou, Y; Babiuk, L A; Liu, Q

    2008-01-01

    Hepatitis C is a devastating disease worldwide. Proteins encoded by the etiologic agent, hepatitis C virus (HCV), are believed to play important roles in HCV-associated pathogenesis. However, the biological functions of the non-structural protein-2 (NS2) encoded by HCV are not well characterized. Here, we show that HCV NS2 protein activates CXCL-8 (interleukin-8, IL-8) transcription in HepG2 cells as measured by reverse transcription-polymerase chain reaction and IL-8 promoter-luciferase reporter assays. Furthermore, when the kappaB site on the IL-8 promoter was eliminated by mutagenesis or when intracellular NF-kappaB activity was suppressed by an inhibitor, NS2 did not activate the IL-8 promoter, suggesting a role of NF-kappaB in this process. These results prompted us to hypothesize that HCV NS2 might be able to activate NF-kappaB. This hypothesis was tested by determination of NF-kappaB-driven reporter gene expression and NF-kappaB p65 subunit subcellular localization after HCV NS2 expression. Indeed, NS2 could up-regulate NF-kappaB-driven luciferase activity and was associated with p65 nuclear localization. These results demonstrate that HCV NS2 up-regulates IL-8 transcription through NF-kappaB. This newly identified function increases our understanding of the role of HCV NS2 protein in virus-host interactions.

  20. The role of PTEN in regulation of hepatic macrophages activation and function in progression and reversal of liver fibrosis.

    PubMed

    Cheng, Yahui; Tian, Yuanyao; Xia, Jialu; Wu, Xiaoqin; Yang, Yang; Li, Xiaofeng; Huang, Cheng; Meng, Xiaoming; Ma, Taotao; Li, Jun

    2017-02-15

    Activation of Kupffer cells (KCs) plays a pivotal role in the pathogenesis of liver fibrosis. The progression and reversal of CCl4-induced mouse liver fibrosis showed a mixed induction of hepatic classical (M1) and alternative (M2) macrophage markers. Although the role of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in modulating myeloid cell activation has recently been identified, its function in macrophage activation during hepatic fibrosis remains to be fully appreciated. In our study, PTEN expression of KCs was remarkably decreased in CCl4-induced mice but increased to a near-normal level in reversed mice. Moreover, PTEN was significantly decreased in IL4-induced RAW 264.7 cells in vitro and lower expression of PTEN was observed in M2 macrophages in vivo. In addition, loss- and gain-of-function studies suggested that PTEN regulates M2 macrophages polarization via activation of PI3K/Akt/STAT6 signaling, but had a limited effect on M1 macrophages polarization in vitro. Additionally, Ly294002, a chemical inhibitor of PI3K/Akt, could dramatically down-regulate the hallmarks of M2 macrophages. In conclusion, PTEN mediates macrophages activation by PI3K/Akt/STAT6 signaling pathway, which provides novel compelling evidences on the potential of PTEN in liver injury and opens new cellular target for the pharmacological therapy of liver fibrosis.

  1. 8-Hydroxyeicosapentaenoic Acid Decreases Plasma and Hepatic Triglycerides via Activation of Peroxisome Proliferator-Activated Receptor Alpha in High-Fat Diet-Induced Obese Mice

    PubMed Central

    Yamada, Hidetoshi; Kikuchi, Sayaka; Hakozaki, Mayuka; Motodate, Kaori; Nagahora, Nozomi; Hirose, Masamichi

    2016-01-01

    PPARs regulate the expression of genes involved in lipid homeostasis. PPARs serve as molecular sensors of fatty acids, and their activation can act against obesity and metabolic syndromes. 8-Hydroxyeicosapentaenoic acid (8-HEPE) acts as a PPAR ligand and has higher activity than EPA. However, to date, the PPAR ligand activity of 8-HEPE has only been demonstrated in vitro. Here, we investigated its ligand activity in vivo by examining the effect of 8-HEPE treatment on high fat diet-induced obesity in mice. After the 4-week treatment period, the levels of plasma and hepatic triglycerides in the 8-HEPE-fed mice were significantly lower than those in the HFD-fed mice. The expression of genes regulated by PPARα was significantly increased in 8-HEPE-fed mice compared to those that received only HFD. Additionally, the level of hepatic palmitic acid in 8-HEPE-fed mice was significantly lower than in HFD-fed mice. These results suggested that intake of 8-HEPE induced PPARα activation and increased catabolism of lipids in the liver. We found no significant differences between EPA-fed mice and HFD-fed mice. We demonstrated that 8-HEPE has a larger positive effect on metabolic syndrome than EPA and that 8-HEPE acts by inducing PPARα activation in the liver. PMID:27239345

  2. Reduced genetic distance and high replication levels increase the RNA recombination rate of hepatitis delta virus.

    PubMed

    Lin, Chia-Chi; Yang, Zhi-Wei; Iang, Shan-Bei; Chao, Mei

    2015-01-02

    Hepatitis delta virus (HDV) replication is carried out by host RNA polymerases. Since homologous inter-genotypic RNA recombination is known to occur in HDV, possibly via a replication-dependent process, we hypothesized that the degree of sequence homology and the replication level should be related to the recombination frequency in cells co-expressing two HDV sequences. To confirm this, we separately co-transfected cells with three different pairs of HDV genomic RNAs and analyzed the obtained recombinants by RT-PCR followed by restriction fragment length polymorphism and sequencing analyses. The sequence divergence between the clones ranged from 24% to less than 0.1%, and the difference in replication levels was as high as 100-fold. As expected, significant differences were observed in the recombination frequencies, which ranged from 0.5% to 47.5%. Furthermore, varying the relative amounts of parental RNA altered the dominant recombinant species produced, suggesting that template switching occurs frequently during the synthesis of genomic HDV RNA. Taken together, these data suggest that during the host RNA polymerase-driven RNA recombination of HDV, both inter- and intra-genotypic recombination events are important in shaping the genetic diversity of HDV.

  3. Cultured Mycelium Cordyceps sinensis allevi¬ates CCl4-induced liver inflammation and fibrosis in mice by activating hepatic natural killer cells

    PubMed Central

    Peng, Yuan; Huang, Kai; Shen, Li; Tao, Yan-yan; Liu, Cheng-hai

    2016-01-01

    Aim: Recent evidence shows that cultured mycelium Cordyceps sinensis (CMCS) effectively protects against liver fibrosis in mice. Here, we investigated whether the anti-fibrotic action of CMCS was related to its regulation of the activity of hepatic natural killer (NK) cells in CCl4-treated mice. Methods: C57BL/6 mice were injected with 10% CCl4 (2 mL/kg, ip) 3 times per week for 4 weeks, and received CMCS (120 mg·kg−1·d−1, ig) during this period. In another part of experiments, the mice were also injected with an NK cell-deleting antibody ASGM-1 (20 μg, ip) 5 times in the first 3 weeks. After the mice were sacrificed, serum liver function, and liver inflammation, hydroxyproline content and collagen deposition were assessed. The numbers of hepatic NK cells and expression of NKG2D (activation receptor of NK cells) on isolated liver lymphocytes were analyzed using flow cytometry. Desmin expression and cell apoptosis in liver tissues were studied using desmin staining and TUNEL assay, respectively. The levels of α-SMA, TGF-β, RAE-1δ and RAE-1ε in liver tissues were determined by RT-qPCR. Results: In CCl4-treated mice, CMCS administration significantly improved liver function, attenuated liver inflammation and fibrosis, and increased the numbers of hepatic NK cells and expression level of NKG2D on hepatic NK cells. Furthermore, CMCS administration significantly decreased desmin expression in liver tissues, and increased TUNEL staining adjacent to hepatic stellate cells. Injection with NK cell-deleting ASGM-1 not only diminished the numbers of hepatic NK cells, but also greatly accelerated liver inflammation and fibrosis in CCl4-treated mice. In CCl4-treated mice with NK cell depletion, CMCS administration decelerated the rate of liver fibrosis development, and mildly upregulated the numbers of hepatic NK cells but without changing NKG2D expression. Conclusion: CMCS allevi¬ates CCl4-induced liver inflammation and fibrosis via promoting activation of hepatic

  4. Eriocitrin ameliorates diet-induced hepatic steatosis with activation of mitochondrial biogenesis

    PubMed Central

    Hiramitsu, Masanori; Shimada, Yasuhito; Kuroyanagi, Junya; Inoue, Takashi; Katagiri, Takao; Zang, Liqing; Nishimura, Yuhei; Nishimura, Norihiro; Tanaka, Toshio

    2014-01-01

    Lemon (Citrus limon) contains various bioactive flavonoids, and prevents obesity and obesity-associated metabolic diseases. We focused on eriocitrin (eriodictyol 7-rutinoside), a powerful antioxidative flavonoid in lemon with lipid-lowering effects in a rat model of high-fat diet. To investigate the mechanism of action of eriocitrin, we conducted feeding experiments on zebrafish with diet-induced obesity. Oral administration of eriocitrin (32 mg/kg/day for 28 days) improved dyslipidaemia and decreased lipid droplets in the liver. DNA microarray analysis revealed that eriocitrin increased mRNA of mitochondrial biogenesis genes, such as mitochondria transcription factor, nuclear respiratory factor 1, cytochrome c oxidase subunit 4, and ATP synthase. In HepG2 cells, eriocitrin also induced the corresponding orthologues, and reduced lipid accumulation under conditions of lipid loading. Eriocitrin increased mitochondrial size and mtDNA content, which resulted in ATP production in HepG2 cells and zebrafish. In summary, dietary eriocitrin ameliorates diet-induced hepatic steatosis with activation of mitochondrial biogenesis. PMID:24424211

  5. Açai (Euterpe oleracea Mart.) Upregulates Paraoxonase 1 Gene Expression and Activity with Concomitant Reduction of Hepatic Steatosis in High-Fat Diet-Fed Rats

    PubMed Central

    Lage, Nara Nunes; Lopes, Juliana Márcia Macedo; de Lima, Wanderson Geraldo

    2016-01-01

    Açai (Euterpe oleracea Mart.), a fruit from the Amazon region, has emerged as a promising source of polyphenols. Açai consumption has been increasing owing to ascribed health benefits and antioxidant properties; however, its effects on hepatic injury are limited. In this study, we evaluated the antioxidant effect of filtered açai pulp on the expression of paraoxonase (PON) isoforms and PON1 activity in rats with nonalcoholic fatty liver disease (NAFLD). The rats were fed a standard AIN-93M (control) diet or a high-fat (HF) diet containing 25% soy oil and 1% cholesterol with or without açai pulp (2 g/day) for 6 weeks. Our results show that açai pulp prevented low-density lipoprotein (LDL) oxidation, increased serum and hepatic PON1 activity, and upregulated the expression of PON1 and ApoA-I in the liver. In HF diet-fed rats, treatment with açai pulp attenuated liver damage, reducing fat infiltration and triglyceride (TG) content. In rats receiving açai, increased serum PON1 activity was correlated with a reduction in hepatic steatosis and hepatic injury. These findings suggest the use of açai as a potential therapy for liver injuries, supporting the idea that dietary antioxidants are a promising approach to enhance the defensive systems against oxidative stress. PMID:27642496

  6. Açai (Euterpe oleracea Mart.) Upregulates Paraoxonase 1 Gene Expression and Activity with Concomitant Reduction of Hepatic Steatosis in High-Fat Diet-Fed Rats.

    PubMed

    Pereira, Renata Rebeca; de Abreu, Isabel Cristina Mallosto Emerich; Guerra, Joyce Ferreira da Costa; Lage, Nara Nunes; Lopes, Juliana Márcia Macedo; Silva, Maísa; de Lima, Wanderson Geraldo; Silva, Marcelo Eustáquio; Pedrosa, Maria Lucia

    2016-01-01

    Açai (Euterpe oleracea Mart.), a fruit from the Amazon region, has emerged as a promising source of polyphenols. Açai consumption has been increasing owing to ascribed health benefits and antioxidant properties; however, its effects on hepatic injury are limited. In this study, we evaluated the antioxidant effect of filtered açai pulp on the expression of paraoxonase (PON) isoforms and PON1 activity in rats with nonalcoholic fatty liver disease (NAFLD). The rats were fed a standard AIN-93M (control) diet or a high-fat (HF) diet containing 25% soy oil and 1% cholesterol with or without açai pulp (2 g/day) for 6 weeks. Our results show that açai pulp prevented low-density lipoprotein (LDL) oxidation, increased serum and hepatic PON1 activity, and upregulated the expression of PON1 and ApoA-I in the liver. In HF diet-fed rats, treatment with açai pulp attenuated liver damage, reducing fat infiltration and triglyceride (TG) content. In rats receiving açai, increased serum PON1 activity was correlated with a reduction in hepatic steatosis and hepatic injury. These findings suggest the use of açai as a potential therapy for liver injuries, supporting the idea that dietary antioxidants are a promising approach to enhance the defensive systems against oxidative stress.

  7. Chrysin attenuates liver fibrosis and hepatic stellate cell activation through TGF-β/Smad signaling pathway.

    PubMed

    Balta, Cornel; Herman, Hildegard; Boldura, Oana Maria; Gasca, Ionela; Rosu, Marcel; Ardelean, Aurel; Hermenean, Anca

    2015-10-05

    We investigated the protective effect of chrysin on chronic liver fibrosis in mice and the potential mechanism underlying TGF-β1-mediated hepatic stellate cells (HSCs) activation on fibrogenesis. Experimental fibrosis was established by intraperitoneal injection of mice with 20% v/v, 2 ml/kg CCl4 twice a week, for 7 weeks. Mice were orally treated with 3 doses of chrysin (50, 100 and 200 mg/kg) or with vehicle as control. For the assessment of the spontaneous reversion of fibrosis, CCl4 treated animals were investigated after two weeks of recovery time. Silymarin was used as standard hepatoprotective flavonoid. Histopathological investigations showed that hepatic fibrosis grade was markedly reduced in the chrysin groups compared to the fibrotic one. Moreover, CCl4 activated HSCs induced an upregulation of smooth muscle actin (α-SMA), an increased number of TGF-β1 immunopositive cells and marked up-regulation of TGF-β1. α-SMA and TGF-β1 levels were significantly reduced in all chrysin treated groups in a dose-dependent manner, whereas the level of spontaneous reversal of fibrosis was lower compared to all flavonoid treated groups. Liver mRNA levels of Smad 2 in the 50, 100 and 200 mg/kg chrysin treated groups were significantly reduced by about 88.54%, 92.15% and 95.56% of the corresponding levels in the fibrosis mice group. The results were similar for mRNA levels of Smad 3. The protective response to silymarin was almost similar to that seen with the highest doses of chrysin. In this study, we have shown that chrysin has the efficacy to reverse CCl4-stimulated liver fibrosis by inhibition of HSCs activation and proliferation through TGF-β1/Smad pathway. These results suggest that chrysin may be useful in stopping or reversing the progression of liver fibrosis and might offer the possibility to develop a new therapeutic drug, useful in treatment of chronic liver diseases.

  8. Angiotensin-converting enzyme 2/angiotensin-(1–7)/Mas axis activates Akt signaling to ameliorate hepatic steatosis

    PubMed Central

    Cao, Xi; Yang, Fangyuan; Shi, Tingting; Yuan, Mingxia; Xin, Zhong; Xie, Rongrong; Li, Sen; Li, Hongbing; Yang, Jin-Kui

    2016-01-01

    The classical axis of renin-angiotensin system (RAS), angiotensin (Ang)-converting enzyme (ACE)/Ang II/AT1, contributes to the development of non-alcoholic fatty liver disease (NAFLD). However, the role of bypass axis of RAS (Angiotensin-converting enzyme 2 (ACE2)/Ang-(1–7)/Mas) in hepatic steatosis is still unclear. Here we showed that deletion of ACE2 aggravates liver steatosis, which is correlated with the increased expression of hepatic lipogenic genes and the decreased expression of fatty acid oxidation-related genes in the liver of ACE2 knockout (ACE2−/y) mice. Meanwhile, oxidative stress and inflammation were also aggravated in ACE2−/y mice. On the contrary, overexpression of ACE2 improved fatty liver in db/db mice, and the mRNA levels of fatty acid oxidation-related genes were up-regulated. In vitro, Ang-(1–7)/ACE2 ameliorated hepatic steatosis, oxidative stress and inflammation in free fatty acid (FFA)-induced HepG2 cells, and what’s more, Akt inhibitors reduced ACE2-mediated lipid metabolism. Furthermore, ACE2-mediated Akt activation could be attenuated by blockade of ATP/P2 receptor/Calmodulin (CaM) pathway. These results indicated that Ang-(1–7)/ACE2/Mas axis may reduce liver lipid accumulation partly by regulating lipid-metabolizing genes through ATP/P2 receptor/CaM signaling pathway. Our findings support the potential role of ACE2/Ang-(1–7)/Mas axis in prevention and treatment of hepatic lipid metabolism. PMID:26883384

  9. MicroR-146 blocks the activation of M1 macrophage by targeting signal transducer and activator of transcription 1 in hepatic schistosomiasis.

    PubMed

    He, Xing; Tang, Rui; Sun, Yue; Wang, Yan-Ge; Zhen, Kui-Yang; Zhang, Dong-Mei; Pan, Wei-Qing

    2016-11-01

    Schistosomiasis is a chronic disease caused by the parasite of the Schistosoma genus and is characterized by egg-induced hepatic granulomas and fibrosis. Macrophages play a central role in schistosomiasis with several studies highlighting their differentiation into M2 cells involved in the survival of infected mice through limitation of immunopathology. However, little is known regarding the mechanisms of regulating macrophage differentiation. Here, we showed that the early stage of infection by Schistosoma japonicum induced expression of type 1T-helper-cell (Th1) cytokine, interferon-γ (IFN-γ), leading to increase in M1 cells. However, the presence of liver-trapped eggs induced the expression of Th2 cytokines including interleukin-4 (IL-4), IL-10, and IL-13 that upregulated the transcription of miR-146b by activating signal transducer and activator of transcription 3/6 (STAT3/6) that bind to the promoter of the pre-miR-146b gene. We found that the miR-146a/b was significantly upregulated in macrophages during the progression of hepatic schistosomiasis. The elevated miR-146a/b inhibited the IFN-γ-induced differentiation of macrophages to M1 cells through targeting STAT1. Our data indicate the protective roles of miR-146a/b in hepatic schistosomiasis through regulating the differentiation of macrophages into M2 cells.

  10. Investigation of antiaromatase activity using hepatic microsomes of Nile tilapia (Oreochromis niloticus).

    PubMed

    Sassa-Deepaeng, Tanongsak; Chaisri, Wasana; Pikulkaew, Surachai; Okonogi, Siriporn

    2017-03-19

    Microsomal aromatase enzymes of humans and rats have been used in antiaromatase assays, but enzyme activity is species-specific. The current study extracted hepatic microsomes of Nile tilapia (Oreochromis niloticus) to investigate and compare the antiaromatase activity of chrysin, quercetin, and quercitrin. This activity was evaluated using a dibenzylfluorescein (DBF) assay. Results revealed that the age and body weight of Nile tilapia affected the yield of extracted microsomes. Extraction of hepatic microsomes of Nile tilapia was most effective when using a reaction medium with a pH of 8.0. A DBF assay using Nile tilapia microsomes revealed significant differences in levels of antiaromatase activity for chrysin, quercetin, and quercitrin. Chrysin was the most potent aromatase inhibitor, with an IC50 of 0.25 mg/mL. In addition, chrysin is an aromatase inhibitor that also inhibits the proliferation of cancer cells. Hepatic microsomes of Nile tilapia can be used to investigate and compare the antiaromatase activity of different compounds.

  11. Hepatic mTORC1 controls locomotor activity, body temperature, and lipid metabolism through FGF21.

    PubMed

    Cornu, Marion; Oppliger, Wolfgang; Albert, Verena; Robitaille, Aaron M; Trapani, Francesca; Quagliata, Luca; Fuhrer, Tobias; Sauer, Uwe; Terracciano, Luigi; Hall, Michael N

    2014-08-12

    The liver is a key metabolic organ that controls whole-body physiology in response to nutrient availability. Mammalian target of rapamycin (mTOR) is a nutrient-activated kinase and central controller of growth and metabolism that is negatively regulated by the tumor suppressor tuberous sclerosis complex 1 (TSC1). To investigate the role of hepatic mTOR complex 1 (mTORC1) in whole-body physiology, we generated liver-specific Tsc1 (L-Tsc1 KO) knockout mice. L-Tsc1 KO mice displayed reduced locomotor activity, body temperature, and hepatic triglyceride content in a rapamycin-sensitive manner. Ectopic activation of mTORC1 also caused depletion of hepatic and plasma glutamine, leading to peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α)-dependent fibroblast growth factor 21 (FGF21) expression in the liver. Injection of glutamine or knockdown of PGC-1α or FGF21 in the liver suppressed the behavioral and metabolic defects due to mTORC1 activation. Thus, mTORC1 in the liver controls whole-body physiology through PGC-1α and FGF21. Finally, mTORC1 signaling correlated with FGF21 expression in human liver tumors, suggesting that treatment of glutamine-addicted cancers with mTOR inhibitors might have beneficial effects at both the tumor and whole-body level.

  12. Hepatic mTORC1 controls locomotor activity, body temperature, and lipid metabolism through FGF21

    PubMed Central

    Cornu, Marion; Oppliger, Wolfgang; Albert, Verena; Robitaille, Aaron M.; Trapani, Francesca; Quagliata, Luca; Fuhrer, Tobias; Sauer, Uwe; Terracciano, Luigi; Hall, Michael N.

    2014-01-01

    The liver is a key metabolic organ that controls whole-body physiology in response to nutrient availability. Mammalian target of rapamycin (mTOR) is a nutrient-activated kinase and central controller of growth and metabolism that is negatively regulated by the tumor suppressor tuberous sclerosis complex 1 (TSC1). To investigate the role of hepatic mTOR complex 1 (mTORC1) in whole-body physiology, we generated liver-specific Tsc1 (L-Tsc1 KO) knockout mice. L-Tsc1 KO mice displayed reduced locomotor activity, body temperature, and hepatic triglyceride content in a rapamycin-sensitive manner. Ectopic activation of mTORC1 also caused depletion of hepatic and plasma glutamine, leading to peroxisome proliferator–activated receptor γ coactivator-1α (PGC-1α)–dependent fibroblast growth factor 21 (FGF21) expression in the liver. Injection of glutamine or knockdown of PGC-1α or FGF21 in the liver suppressed the behavioral and metabolic defects due to mTORC1 activation. Thus, mTORC1 in the liver controls whole-body physiology through PGC-1α and FGF21. Finally, mTORC1 signaling correlated with FGF21 expression in human liver tumors, suggesting that treatment of glutamine-addicted cancers with mTOR inhibitors might have beneficial effects at both the tumor and whole-body level. PMID:25082895

  13. Are municipal solid waste collectors at increased risk of Hepatitis A Virus infection? A Greek cross-sectional study.

    PubMed

    Rachiotis, George; Tsovili, Eva; Papagiannis, Dimitrios; Markaki, Adelais; Hadjichristodoulou, Christos

    2016-12-01

    Municipal solid waste collectors are reportedly at risk for Hepatitis A virus infection (HAV) as an occupational hazard. We aimed to investigate the prevalence and possible risk factors of HAV infection among solid waste collectors in a municipality of the broader region of Attica, Greece. A cross-sectional sero-prevalence study was conducted. Fifty (n=50) waste collectors participated in the study (response rate: 95%). The group of municipal waste collectors was compared to a convenient sample of workers not exposed to solid waste (n=83). Municipal solid waste collectors recorded a higher, but not statistically significant, prevalence of anti-HAV(+) in comparison to subjects without occupational exposure to waste (40% vs 34% respectively p=0,4). No significant associations were found between inappropriate work practices and anti- HAV (+). Education was the only factor independently associated with the risk of HAV infection. This study did not corroborate previous reports of an increased prevalence of Hepatitis A Virus infection among municipal solid waste collectors.

  14. The biphasic nature of hypoxia-induced directional migration of activated human hepatic stellate cells.

    PubMed

    Novo, Erica; Povero, Davide; Busletta, Chiara; Paternostro, Claudia; di Bonzo, Lorenzo Valfrè; Cannito, Stefania; Compagnone, Alessandra; Bandino, Andrea; Marra, Fabio; Colombatto, Sebastiano; David, Ezio; Pinzani, Massimo; Parola, Maurizio

    2012-03-01

    Liver fibrogenesis is sustained by pro-fibrogenic myofibroblast-like cells (MFs), mainly originating from activated hepatic stellate cells (HSC/MFs) or portal (myo)fibroblasts, and is favoured by hypoxia-dependent angiogenesis. Human HSC/MFs were reported to express vascular-endothelial growth factor (VEGF) and VEGF-receptor type 2 and to migrate under hypoxic conditions. This study was designed to investigate early and delayed signalling mechanisms involved in hypoxia-induced migration of human HSC/MFs. Signal transduction pathways and intracellular generation of reactive oxygen species (ROS) were evaluated by integrating morphological, cell, and molecular biology techniques. Non-oriented and oriented migration were evaluated by using wound healing assay and the modified Boyden's chamber assay, respectively. The data indicate that hypoxia-induced migration of HSC/MFs is a biphasic process characterized by the following sequence of events: (a) an early (15 min) and mitochondria-related increased generation of intracellular ROS which (b) was sufficient to switch on activation of ERK1/2 and JNK1/2 that were responsible for the early phase of oriented migration; (c) a delayed and HIF-1α-dependent increase in VEGF expression (facilitated by ROS) and its progressive, time-dependent release in the extracellular medium that (d) was mainly responsible for sustained migration of HSC/MFs. Finally, immunohistochemistry performed on HCV-related fibrotic/cirrhotic livers revealed HIF-2α and haem-oxygenase-1 positivity in hepatocytes and α-SMA-positive MFs, indicating that MFs were likely to be exposed in vivo to both hypoxia and oxidative stress. In conclusion, hypoxia-induced migration of HSC/MFs involves an early, mitochondrial-dependent ROS-mediated activation of ERK and JNK, followed by a delayed- and HIF-1α-dependent up-regulation and release of VEGF.

  15. Deep sequencing increases hepatitis C virus phylogenetic cluster detection compared to Sanger sequencing.

    PubMed

    Montoya, Vincent; Olmstead, Andrea; Tang, Patrick; Cook, Darrel; Janjua, Naveed; Grebely, Jason; Jacka, Brendan; Poon, Art F Y; Krajden, Mel

    2016-09-01

    Effective surveillance and treatment strategies are required to control the hepatitis C virus (HCV) epidemic. Phylogenetic analyses are powerful tools for reconstructing the evolutionary history of viral outbreaks and identifying transmission clusters. These studies often rely on Sanger sequencing which typically generates a single consensus sequence for each infected individual. For rapidly mutating viruses such as HCV, consensus sequencing underestimates the complexity of the viral quasispecies population and could therefore generate different phylogenetic tree topologies. Although deep sequencing provides a more detailed quasispecies characterization, in-depth phylogenetic analyses are challenging due to dataset complexity and computational limitations. Here, we apply deep sequencing to a characterized population to assess its ability to identify phylogenetic clusters compared with consensus Sanger sequencing. For deep sequencing, a sample specific threshold determined by the 50th percentile of the patristic distance distribution for all variants within each individual was used to identify clusters. Among seven patristic distance thresholds tested for the Sanger sequence phylogeny ranging from 0.005-0.06, a threshold of 0.03 was found to provide the maximum balance between positive agreement (samples in a cluster) and negative agreement (samples not in a cluster) relative to the deep sequencing dataset. From 77 HCV seroconverters, 10 individuals were identified in phylogenetic clusters using both methods. Deep sequencing analysis identified an additional 4 individuals and excluded 8 other individuals relative to Sanger sequencing. The application of this deep sequencing approach could be a more effective tool to understand onward HCV transmission dynamics compared with Sanger sequencing, since the incorporation of minority sequence variants improves the discrimination of phylogenetically linked clusters.

  16. Lacking of estradiol reduces insulin exocytosis from pancreatic β-cells and increases hepatic insulin degradation.

    PubMed

    Santos, Roberta S; Batista, Thiago M; Camargo, Rafael L; Morato, Priscila N; Borck, Patrícia C; Leite, Nayara C; Kurauti, Mirian A; Wanschel, Amarylis C B A; Nadal, Ángel; Clegg, Deborah J; Carneiro, Everardo M

    2016-10-01

    Low levels of plasma estrogens are associated with weight-gain, android fat distribution, and a high prevalence of obesity-related comorbidities such as glucose intolerance and type II diabetes. The mechanisms underlying the association between low levels of estrogens and impaired glucose homeostasis are not completely understood. To begin to test this, we used three-month-old female C57BL/6J mice that either underwent ovariectomy (OVX) or received a sham surgery (Sham), and we characterized glucose homeostasis. In a subsequent series of experiments, OVX mice received estradiol treatment (OVX+E2) or vehicle (OVX) for 6 consecutive days. As has been previously reported, lack of ovarian hormones resulted in dysregulated glucose homeostasis. To begin to explore the mechanisms by which this occurs, we characterized the impact of estrogens on insulin secretion and degradation in these mice. Insulin secretion and plasma insulin levels were lower in OVX mice. OVX mice had lower levels of pancreatic Syntaxin 1-A (Synt-1A) protein, which is involved in insulin extrusion from the pancreas. In the liver, OVX mice had higher levels of insulin-degrading enzyme (IDE) and this was associated with higher insulin clearance. Estradiol treatment improved glucose intolerance in OVX mice and restored insulin secretion, as well as normalized the protein content of pancreatic Synt-1A. The addition of estrogens to OVX mice reduced IDE protein to that of Sham mice. Our data suggest loss of ovarian estradiol following OVX led to impaired glucose homeostasis due to pancreatic β-cell dysfunction in the exocytosis of insulin, and upregulation of hepatic IDE protein content resulting in lower insulinemia, which was normalized by estradiol replacement.

  17. Hepatitis B infection is associated with an increased incidence of thrombocytopenia in healthy adults without cirrhosis.

    PubMed

    Joo, E-J; Chang, Y; Yeom, J-S; Lee, Y-G; Ryu, S

    2017-03-01

    The association between HBV infection and incident thrombocytopenia among subjects without cirrhosis or splenomegaly is unknown. Therefore, we sought to elucidate the association between HBV infection and the development of thrombocytopenia in a large cohort of apparently healthy men and women. A cohort study was performed in 122 200 participants without liver cirrhosis or splenomegaly who underwent comprehensive health examinations and were followed until December 2014. HBV infection was defined by the presence of hepatitis B surface antigen (HBsAg) at baseline. Thrombocytopenia was defined as a platelet count <150 000/μL. Cox proportional hazard models were used to estimate adjusted hazard ratios with 95% confidence intervals (CIs) for incident thrombocytopenia. HBsAg was positive in 4857 of 122 200 subjects (4.0%) at baseline. During 883 983 person-years of follow-up, 2037 incident cases of thrombocytopenia were identified (incident rate 2.3 per 1000 person-years). HBsAg-positive subjects had a higher incidence of thrombocytopenia than did healthy controls (11.2 vs 1.9 per 1000 person-years, respectively). The multivariate-adjusted hazard ratio (95% CI) for incident thrombocytopenia comparing HBsAg-positive to HBsAg-negative subjects was 5.71 (5.10-6.38). Strong associations between HBsAg positivity and thrombocytopenia were consistently observed across prespecified subgroups. In this large cohort study of an apparently healthy population, HBsAg positivity was strongly and independently associated with incident thrombocytopenia, indicating that mechanisms of thrombocytopenia other than portal hypertension may exist in healthy HBV carriers.

  18. Dietary protein-induced hepatic IGF-1 secretion mediated by PPARγ activation

    PubMed Central

    Wan, Xiaojuan; Wang, Songbo; Xu, Jingren; Zhuang, Lu; Xing, Kongping; Zhang, Mengyuan; Zhu, Xiaotong; Wang, Lina; Gao, Ping; Xi, Qianyun; Sun, Jiajie; Zhang, Yongliang; Li, Tiejun; Shu, Gang; Jiang, Qingyan

    2017-01-01

    Dietary protein or amino acid (AA) is a crucial nutritional factor to regulate hepatic insulin-like growth factor-1 (IGF-1) expression and secretion. However, the underlying intracellular mechanism by which dietary protein or AA induces IGF-1 expression remains unknown. We compared the IGF-1 gene expression and plasma IGF-1 level of pigs fed with normal crude protein (CP, 20%) and low-protein levels (LP, 14%). RNA sequencing (RNA-seq) was performed to detect transcript expression in the liver in response to dietary protein. The results showed that serum concentrations and mRNA levels of IGF-1 in the liver were higher in the CP group than in the LP group. RNA-seq analysis identified a total of 1319 differentially expressed transcripts (667 upregulated and 652 downregulated), among which the terms “oxidative phosphorylation”, “ribosome”, “gap junction”, “PPAR signaling pathway”, and “focal adhesion” were enriched. In addition, the porcine primary hepatocyte and HepG2 cell models also demonstrated that the mRNA and protein levels of IGF-1 and PPARγ increased with the increasing AA concentration in the culture. The PPARγ activator troglitazone increased IGF-1 gene expression and secretion in a dose dependent manner. Furthermore, inhibition of PPARγ effectively reversed the effects of the high AA concentration on the mRNA expression of IGF-1 and IGFBP-1 in HepG2 cells. Moreover, the protein levels of IGF-1 and PPARγ, as well as the phosphorylation of mTOR, significantly increased in HepG2 cells under high AA concentrations. mTOR phosphorylation can be decreased by the mTOR antagonist, rapamycin. The immunoprecipitation results also showed that high AA concentrations significantly increased the interaction of mTOR and PPARγ. In summary, PPARγ plays an important role in the regulation of IGF-1 secretion and gene expression in response to dietary protein. PMID:28257428

  19. Dietary protein-induced hepatic IGF-1 secretion mediated by PPARγ activation.

    PubMed

    Wan, Xiaojuan; Wang, Songbo; Xu, Jingren; Zhuang, Lu; Xing, Kongping; Zhang, Mengyuan; Zhu, Xiaotong; Wang, Lina; Gao, Ping; Xi, Qianyun; Sun, Jiajie; Zhang, Yongliang; Li, Tiejun; Shu, Gang; Jiang, Qingyan

    2017-01-01

    Dietary protein or amino acid (AA) is a crucial nutritional factor to regulate hepatic insulin-like growth factor-1 (IGF-1) expression and secretion. However, the underlying intracellular mechanism by which dietary protein or AA induces IGF-1 expression remains unknown. We compared the IGF-1 gene expression and plasma IGF-1 level of pigs fed with normal crude protein (CP, 20%) and low-protein levels (LP, 14%). RNA sequencing (RNA-seq) was performed to detect transcript expression in the liver in response to dietary protein. The results showed that serum concentrations and mRNA levels of IGF-1 in the liver were higher in the CP group than in the LP group. RNA-seq analysis identified a total of 1319 differentially expressed transcripts (667 upregulated and 652 downregulated), among which the terms "oxidative phosphorylation", "ribosome", "gap junction", "PPAR signaling pathway", and "focal adhesion" were enriched. In addition, the porcine primary hepatocyte and HepG2 cell models also demonstrated that the mRNA and protein levels of IGF-1 and PPARγ increased with the increasing AA concentration in the culture. The PPARγ activator troglitazone increased IGF-1 gene expression and secretion in a dose dependent manner. Furthermore, inhibition of PPARγ effectively reversed the effects of the high AA concentration on the mRNA expression of IGF-1 and IGFBP-1 in HepG2 cells. Moreover, the protein levels of IGF-1 and PPARγ, as well as the phosphorylation of mTOR, significantly increased in HepG2 cells under high AA concentrations. mTOR phosphorylation can be decreased by the mTOR antagonist, rapamycin. The immunoprecipitation results also showed that high AA concentrations significantly increased the interaction of mTOR and PPARγ. In summary, PPARγ plays an important role in the regulation of IGF-1 secretion and gene expression in response to dietary protein.

  20. Lysis of primary hepatic tumours by lymphokine activated killer cells.

    PubMed Central

    Hsieh, K H; Shu, S Y; Lee, C S; Chu, C T; Yang, C S; Chang, K J

    1987-01-01

    Lymphokine activated killer cell is a newly described lytic system against a variety of solid tumours and is distinct in several respects from the classic cytolytic T cell and the natural killer systems. This study was conducted to evaluate the lytic activity of lymphokine activated killer cells against fresh autologous and allogeneic, as well as cultured hepatocellular carcinoma cells. Lymphokine activated killer cell was generated by incubating peripheral blood mononuclear cells with various concentrations of recombinant IL-2 (rIL-2, Cetus, USA) for various periods of time. A four hour 51Cr release assay was used to measure cytotoxicity. The results show that fresh and cultured hepatocellular carcinoma cells were only slightly susceptible to natural killer cells. Normal hepatocytes were resistant to lymphokine activated killer-mediated lysis. Lymphokine activated killer cells could be generated from mononuclear cells of hepatocellular carcinoma patients and normal subjects with lytic activity against fresh autologous and allogeneic and cultured hepatocellular carcinoma cells, but lymphokine activated killer cells from the former was less efficient than that from the latter. It is concluded that the adoptive immunotherapy with combined rIL-2 and lymphokine activated killer may be worth trying in early cases of primary hepatocellular carcinoma. PMID:3030899

  1. Activation of AMPK/MnSOD signaling mediates anti-apoptotic effect of hepatitis B virus in hepatoma cells

    PubMed Central

    Li, Lei; Hong, Hong-Hai; Chen, Shi-Ping; Ma, Cai-Qi; Liu, Han-Yan; Yao, Ya-Chao

    2016-01-01

    AIM: To investigate the anti-apoptotic capability of the hepatitis B virus (HBV) in the HepG2 hepatoma cell line and the underlying mechanisms. METHODS: Cell viability and apoptosis were measured by MTT assay and flow cytometry, respectively. Targeted knockdown of manganese superoxide dismutase (MnSOD), AMP-activated protein kinase (AMPK) and hepatitis B virus X protein (HBx) genes as well as AMPK agonist AICAR and antagonist compound C were employed to determine the correlations of expression of these genes. RESULTS: HBV markedly protected the hepatoma cells from growth suppression and cell death in the condition of serum deprivation. A decrease of superoxide anion production accompanied with an increase of MnSOD expression and activity was found in HepG2.215 cells. Moreover, AMPK activation contributed to the up-regulation of MnSOD. HBx protein was identified to induce the expression of AMPK and MnSOD. CONCLUSION: Our results suggest that HBV suppresses mitochondrial superoxide level and exerts an anti-apoptotic effect by activating AMPK/MnSOD signaling pathway, which may provide a novel pharmacological strategy to prevent HCC. PMID:27158203

  2. MircoRNA-145 promotes activation of hepatic stellate cells via targeting krüppel-like factor 4

    PubMed Central

    Men, Ruoting; Wen, Maoyao; Zhao, Mingyue; Dan, Xuelian; Yang, Zongze; Wu, Wenchao; Wang, Maggie Haitian; Liu, Xiaojing; Yang, Li

    2017-01-01

    Krüppel-like Factor 4 (KLF4), a target gene of miR-145, can negatively regulate lung fibrosis. However, the potential role of KLF4 and miR-145 in hepatic stellate cells (HSCs) activation or in hepatic fibrosis keeps unclear. This study aims to characterize miR-145 and KLF4 in activated HSCs and liver cirrhotic, and the underlying molecular basis. miR-145 was significantly up-regulated, while KLF4 was dramatically down-regulated during the activation of rat primary HSCs and TGF-βtreated HSCs. Furthermore, miR-145 mimics induced and inhibition of miR-145 reduced α-SMA and COL-I expression in primary HSCs. Additionally, the mRNA and protein levels of KLF4 in the liver of cirrhotic patients and rats were significantly down-regulated. α-SMA and COL-I were increased after inhibition of KLF4 by specific shRNA in primary HSCs. Forced KLF4 expression led to a reduction of α-SMA and COL-I expression in HSCs. miR-145 promotes HSC activation and liver fibrosis by targeting KLF4. PMID:28091538

  3. Sertraline, an antidepressant, induces apoptosis in hepatic cells through the mitogen-activated protein kinase pathway.

    PubMed

    Chen, Si; Xuan, Jiekun; Wan, Liqing; Lin, Haixia; Couch, Letha; Mei, Nan; Dobrovolsky, Vasily N; Guo, Lei

    2014-02-01

    Sertraline is generally used for the treatment of depression and is also approved for the treatment of panic, obsessive-compulsive, and posttraumatic stress disorders. Previously, using rat primary hepatocytes and isolated mitochondria, we demonstrated that sertraline caused hepatic cytotoxicity and mitochondrial impairment. In the current study, we investigated and characterized molecular mechanisms of sertraline toxicity in human hepatoma HepG2 cells. Sertraline decreased cell viability and induced apoptosis in a dose- and time-dependent manner. Sertraline activated the intrinsic checkpoint protein caspase-9 and caused the release of cytochrome c from mitochondria to cytosol; this process was Bcl-2 family dependent because antiapoptotic Bcl-2 family proteins were decreased. Pretreatment of the HepG2 cells with caspase-3, caspase-8, and caspase-9 inhibitors partially but significantly reduced the release of lactate dehydrogenase, indicating that sertraline-induced apoptosis is mediated by both intrinsic and extrinsic apoptotic pathways. Moreover, sertraline markedly increased the expression of tumor necrosis factor (TNF) and the phosphorylation of JNK, extracellular signal-regulated kinase (ERK1/2), and p38. In sertraline-treated cells, the induction of apoptosis and cell death was shown to be the result of activation of JNK, but not ERK1/2 or p38 in the mitogen-activated protein kinase (MAPK) pathway. Furthermore, silencing MAP4K4, the upstream kinase of JNK, attenuated both apoptosis and cell death caused by sertraline. Taken together, our findings suggest that sertraline induced apoptosis in HepG2 cells at least partially via activation of the TNF-MAP4K4-JNK cascade signaling pathway.

  4. ER Stress-induced Inflammasome Activation Contributes to Hepatic Inflammation and Steatosis

    PubMed Central

    Zhang, Jinyu; Zhang, Kezhong; Li, Zihai; Guo, Beichu

    2016-01-01

    Endoplasmic reticulum (ER) stress functions as a protein folding and quality control mechanism to maintain cell homeostasis. Emerging evidence indicates that ER stress is also involved in metabolic and inflammatory diseases. However, the link between ER stress and inflammation remains not well characterized. In this study, we have demonstrated that ER stress-induced inflammasome activation plays a critical role in the pathogenesis of hepatic steatosis. By utilizing genetic and pharmacological agent-induced hepatic steatosis animal models, we found that hepatic steatosis was associated with inflammasome activation and ER stress. Our results show that caspase-1 ablation alleviated liver inflammation and injury. Liver tissues from caspase-1 KO mice had significantly reduced production of IL-1β under ER stress conditions. We also found that ER stress promoted inflammasome activation and IL-1β processing in both hepatocytes and Kupffer cells/macrophages. Moreover, lack of caspase-1 ameliorated cell death or pyropoptosis of hepatocytes induced by ER stress. Taken together, our findings suggest that ER stress-induced inflammasome activation and IL-1β production generate a positive feedback loop to amplify inflammatory response, eventually leading to liver steatosis and injury. PMID:27942420

  5. The Dipeptidyl Peptidase-4 Inhibitor Teneligliptin Attenuates Hepatic Lipogenesis via AMPK Activation in Non-Alcoholic Fatty Liver Disease Model Mice.

    PubMed

    Ideta, Takayasu; Shirakami, Yohei; Miyazaki, Tsuneyuki; Kochi, Takahiro; Sakai, Hiroyasu; Moriwaki, Hisataka; Shimizu, Masahito

    2015-12-08

    Non-alcoholic fatty liver disease (NAFLD), which is strongly associated with metabolic syndrome, is increasingly a major cause of hepatic disorder. Dipeptidyl peptidase (DPP)-4 inhibitors, anti-diabetic agents, are expected to be effective for the treatment of NAFLD. In the present study, we established a novel NAFLD model mouse using monosodium glutamate (MSG) and a high-fat diet (HFD) and investigated the effects of a DPP-4 inhibitor, teneligliptin, on the progression of NAFLD. Male MSG/HFD-treated mice were divided into two groups, one of which received teneligliptin in drinking water. Administration of MSG and HFD caused mice to develop severe fatty changes in the liver, but teneligliptin treatment improved hepatic steatosis and inflammation, as evaluated by the NAFLD activity score. Serum alanine aminotransferase and intrahepatic triglyceride levels were significantly decreased in teneligliptin-treated mice (p < 0.05). Hepatic mRNA levels of the genes involved in de novo lipogenesis were significantly downregulated by teneligliptin (p < 0.05). Moreover, teneligliptin increased hepatic expression levels of phosphorylated AMP-activated protein kinase (AMPK) protein. These findings suggest that teneligliptin attenuates lipogenesis in the liver by activating AMPK and downregulating the expression of genes involved in lipogenesis. DPP-4 inhibitors may be effective for the treatment of NAFLD and may be able to prevent its progression to non-alcoholic steatohepatitis.

  6. Diabetes mellitus increases the risk of hepatocellular carcinoma in treatment-naïve chronic hepatitis C patients in China

    PubMed Central

    Li, Xu; Xu, Hongqin; Gao, Yang; Pan, Meng; Wang, Le; Gao, Pujun

    2017-01-01

    Abstract We investigated the link between diabetes mellitus (DM) and hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) risk in treatment-naïve chronic hepatitis C (CHC) patients in China. To examine the association between DM and HCC, we conducted a case–control study of 300 Chinese CHC patients with HCC, compared to an age- and sex-matched control group of 517 CHC patients not diagnosed with HCC. We found that DM was more prevalent in the HCC patient group (18.7%) than in the CHC-only patient group (10.8%). We conducted logistic regression analyses adjusting for demographics features and other HCC risk factors and found that DM increased the risk of HCC development nearly 2-fold [adjusted odds ratio (AOR), 95% confidence interval (95% CI), 1.80 (1.17–2.75)]. Meanwhile, the proportion of HCC patients and CHC-only patients with liver cirrhosis were 79.3% and 46.2%, respectively, yielding an AOR of 4.62 (95% CI, 3.31–6.46). Multivariate analyses comparing the risk of HCV-related HCC development in DM patients with and without liver cirrhosis revealed that the estimated AOR (95% CI) for those with liver cirrhosis was 5.60 (2.25–13.96). However, the HCC risk decreased significantly with a later age of diabetes onset (AOR [95% CI], 0.94 [0.89–0.99]). DM was associated with an increased risk for HCC development in treatment-naïve CHC patients in China. Furthermore, liver cirrhosis and an early DM diagnoses further increased the risks of HCC development in patients diagnosed with both CHC and DM. PMID:28353605

  7. Xenobiotics in gametes of Lake Michigan lake trout (Salvelinus namaycush) induce hepatic monooxygenase activity in their offspring

    SciTech Connect

    Binder, R.L.; Lech, J.J.

    1984-12-01

    Eggs spawned from Lake Michigan lake trout contain a number of xenobiotic compounds, including polychlorinated biphenyls (PCBs). To assess whether this contamination is sufficient to induce hepatic cytochrome P-450-dependent monooxygenase (MO) activity during early development, the hepatic MO systems of laboratory-cultured offspring of Lake Michigan, Green Bay, and Marquette Hatchery lake trout were compared. Additionally, the induction of hepatic cytochrome P-450 systems in developing lake trout by the commercial PCB mixture, Aroclor 1254 (A1254), was characterized. During late embryonic development and at the swim-up stage, the hepatic MO systems of the feral lake trout offspring appeared induced, based on levels of aryl hydrocarbon hydroxylase (AHH) activity that were 3.5- to 8.6-fold higher than the hatchery control levels. Furthermore, at the swim-up stage the feral trout offspring resembled A1254-treated hatchery fry with regard to the degree of inhibition of hepatic AHH activity by alpha-naphthoflavone, and the presence of an inducible Mr . 58,000 polypeptide in hepatic microsomes. The levels of aminopyrine N-demethylase activity, which was relatively unresponsive to inducers, were moderately lower in the Lake Michigan and Green Bay swim-up fry compared to the hatchery control levels. After 7 months of posthatching laboratory culture, when residues of xenobiotics present at fertilization were greatly diluted by growth, the hepatic MO systems of the Lake Michigan and hatchery trout offspring appeared essentially indistinguishable with regard to a number of parameters.

  8. Effects of Chinese, Japanese and Western tea on hepatic P450 enzyme activities in rats.

    PubMed

    Niwattisaiwong, N; Luo, X X; Coville, P F; Wanwimolruk, S

    2004-01-01

    Previous studies have reported that green tea effectively protects against cancers caused by various dietary carcinogens. As P450 enzymes are the major system responsible for the metabolism of many carcinogens, we hypothesise that tea consumption may alter the catalytic activities of P450 enzymes. We conducted this study to screen the effects of four different teas on the activities of P450 enzymes. Tea solutions (2.5%) were prepared by adding boiling water to tea leaves and filtering. Female Wistar rats were divided into five groups (n = 4 each); each had free access to tea solutions while the control group was supplied with water for 4 weeks. Animals were sacrificed and livers were removed for preparation of microsomes. Enzyme activities were determined by incubation of liver microsomes with the appropriate CYP substrate. The activity of CYP1A1 in livers from rats receiving Oolong (Chinese) tea (185 +/- 63 pmol/mg/min), Japanese green tea (197 +/- 22 pmol/mg/min) and Earl Grey tea (228 +/- 40 pmol/mg/min) was significantly higher (p < 0.05) than in the control group (94 +/- 34 pmol/mg/min), whereas no change was observed in the activity of CYP1A2 in any of tested animals. The hepatic activity of CYP2D6 was greater only in rats drinking Earl Grey tea compared to the controls (235 +/- 37 vs 161 +/- 41 pmol/mg/min, p < 0.05). There were also significant increases (p < 0.05) in the activity of CYP3A in livers of animals given Oolong tea (653 +/- 174 vs 382 +/- 114 pmol/mg/min) and Earl Grey tea (751 +/- 202 pmol/mg/min), while Jasmine and Japanese green tea had no significant effect. These results indicate that not all types of tea cause alterations in liver CYP enzymes as some elevated activities and some did not. Further studies are needed to determine whether there is a relationship between the effect of tea on CYP activities and anti-carcinogenesis.

  9. Epigallocatechin-3-gallate enhances key enzymatic activities of hepatic thioredoxin and glutathione systems in selenium-optimal mice but activates hepatic Nrf2 responses in selenium-deficient mice.

    PubMed

    Dong, Ruixia; Wang, Dongxu; Wang, Xiaoxiao; Zhang, Ke; Chen, Pingping; Yang, Chung S; Zhang, Jinsong

    2016-12-01

    Selenium participates in the antioxidant defense mainly through a class of selenoproteins, including thioredoxin reductase. Epigallocatechin-3-gallate (EGCG) is the most abundant and biologically active catechin in green tea. Depending upon the dose and biological systems, EGCG may function either as an antioxidant or as an inducer of antioxidant defense via its pro-oxidant action or other unidentified mechanisms. By manipulating the selenium status, the present study investigated the interactions of EGCG with antioxidant defense systems including the thioredoxin system comprising of thioredoxin and thioredoxin reductase, the glutathione system comprising of glutathione and glutathione reductase coupled with glutaredoxin, and the Nrf2 system. In selenium-optimal mice, EGCG increased hepatic activities of thioredoxin reductase, glutathione reductase and glutaredoxin. These effects of EGCG appeared to be not due to overt pro-oxidant action because melatonin, a powerful antioxidant, did not influence the increase. However, in selenium-deficient mice, with low basal levels of thioredoxin reductase 1, the same dose of EGCG did not elevate the above-mentioned enzymes; intriguingly EGCG in turn activated hepatic Nrf2 response, leading to increased heme oxygenase 1 and NAD(P)H:quinone oxidoreductase 1 protein levels and thioredoxin activity. Overall, the present work reveals that EGCG is a robust inducer of the Nrf2 system only in selenium-deficient conditions. Under normal physiological conditions, in selenium-optimal mice, thioredoxin and glutathione systems serve as the first line defense systems against the stress induced by high doses of EGCG, sparing the activation of the Nrf2 system.

  10. Tuning a cellular lipid kinase activity adapts hepatitis C virus to replication in cell culture.

    PubMed

    Harak, Christian; Meyrath, Max; Romero-Brey, Inés; Schenk, Christian; Gondeau, Claire; Schult, Philipp; Esser-Nobis, Katharina; Saeed, Mohsan; Neddermann, Petra; Schnitzler, Paul; Gotthardt, Daniel; Perez-Del-Pulgar, Sofia; Neumann-Haefelin, Christoph; Thimme, Robert; Meuleman, Philip; Vondran, Florian W R; Francesco, Raffaele De; Rice, Charles M; Bartenschlager, Ralf; Lohmann, Volker

    2016-12-19

    With a single exception, all isolates of hepatitis C virus (HCV) require adaptive mutations to replicate efficiently in cell culture. Here, we show that a major class of adaptive mutations regulates the activity of a cellular lipid kinase, phosphatidylinositol 4-kinase IIIα (PI4KA). HCV needs to stimulate PI4KA to create a permissive phosphatidylinositol 4-phosphate-enriched membrane microenvironment in the liver and in primary human hepatocytes (PHHs). In contrast, in Huh7 hepatoma cells, the virus must acquire loss-of-function mutations that prevent PI4KA overactivation. This adaptive mechanism is necessitated by increased PI4KA levels in Huh7 cells compared with PHHs, and is conserved across HCV genotypes. PI4KA-specific inhibitors promote replication of unadapted viral isolates and allow efficient replication of patient-derived virus in cell culture. In summary, this study has uncovered a long-sought mechanism of HCV cell-culture adaptation and demonstrates how a virus can adapt to changes in a cellular environment associated with tumorigenesis.

  11. [Acquired partial lipodystrophy. Insulin resistance, hepatic lipase activity and small and dense LDL particles].

    PubMed

    Paglione, A M; Ferrari, N; Berg, G; Frechtel, G; Taverna, M; Fasulo, V; Lopez, G I; Gomez, R M; Bruno, O; Ruiz, M; Wikinski, R L

    2001-01-01

    Partial lipodystrophy (PLD) is an infrequent condition characterized by symmetric loss of subcutaneous adipose tissue in the upper or lower part of the body, although occasionally it affects only the extremities. In all cases it appears along with acantosis nigricans (AN), insulin resistance and impairment in the metabolism of lipids and carbohydrates. The case depicted pertains to a 49 year old female with no family history involving loss of adipose tissue in face and upper body. No fat in lower part of body was observed. The patient showed facial thinning at age 8, AN at 11 and gestational diabetes during her fourth pregnancy at 33. At present, the patient presents severe hyperglycemia and hyperinsulinemia with a marked insulin resistance. Type IV hyperlipoproteinemia (OMS), declined C-HDL and Apo A1 and low C-LDL but with a high proportion of small and dense LDL particles were present. Non esterified fatty acids were high. Lipoprotein lipase and hepatic lipase activities are in the lower limit and increased respectively. Fraction C3 of the complement was diminished. No mutations were observed either in codons 170, 809 and 972 of the IRS-1 receptor or in codon 276 of the adrenergic beta 2 gene.

  12. Survey of surveillance systems and select prevention activities for hepatitis B and C, European Union/European Economic Area, 2009.

    PubMed

    Duffell, E F; van de Laar, M J

    2015-04-02

    Hepatitis B and C viral infections are leading causes of hepatic cirrhosis and cancer. The incidence and prevalence of both hepatitis B and C varies across European countries. European wide surveillance data help to understand the dynamic epidemiology of hepatitis B and C, which is important for the implementation and effectiveness of prevention and control activities.Comparison of surveillance data between countries in Europe is hampered by the differences in national healthcare and reporting systems. This report presents the results of a survey in 2009 which was undertaken to collect baseline information on surveillance systems and core prevention programmes for hepatitis B and C in individual European Union/ European Economic Area countries. The results provide key information to aid the interpretation of surveillance data, and while indicating heterogeneity in national surveillance systems and programmes, they highlight the potential of these systems. This resource has supported the implementation of a standardised European enhanced surveillance programme.

  13. Paraproteins with antibody activity in acute viral hepatitis and chronic autoimmune liver diseases

    PubMed Central

    Roux, Maria E. B.; Florin-Christensen, A.; Arana, R. M.; Doniach, Deborah

    1974-01-01

    Of 27 patients with liver disease and cryoglobulinaemia 18 proved to have paraproteins. Six of these monoclonal immunoglobulins were shown to have antibody activity, directed to human gamma globulin, alpha1-fetoprotein, smooth muscle, and mitochondria. Eight of the patients suffered from acute viral hepatitis, five of whom were HB Ag positive; in all these cases the monoclonal spikes were transient and their antibody activities were directed against IgG in two cases and alpha1-fetoprotein in one. Seven of the patients had active chronic hepatitis and in these the paraproteinaemia persisted, though remaining quantitatively unchanged over several years. One of them had a cryoprecipitable monoclonal smooth muscle antibody. Three patients had primary biliary cirrhosis and in two of them monoclonal IgM mitochondrial antibodies were demonstrated. In three out of the 18 cases there was a double M-component. Since these monoclonal antibodies are directed to autoantigens not unlike the polyclonal ones usually seen in autoimmune hepatic diseases, it is suggested that the factor which triggers the uncontrolled plasma cell proliferation to produce paraproteins must meet cells from an already expanding clone. PMID:18668850

  14. How Active Are Your Students? Increasing Physical Activity in Schools

    ERIC Educational Resources Information Center

    Avery, Marybell; Brandt, Janet

    2010-01-01

    The U. S. Department of Health and Human Services recommends that youth engage in at least 60 minutes of physical activity each day, most of which should be either moderate- or vigorous-intensity aerobic physical activity. Half of this amount (30 minutes) should be achieved during the school day. NASPE provides guidance in the form of a…

  15. Capsaicin Inhibits Dimethylnitrosamine-Induced Hepatic Fibrosis by Inhibiting the TGF-β1/Smad Pathway via Peroxisome Proliferator-Activated Receptor Gamma Activation.

    PubMed

    Choi, Jae Ho; Jin, Sun Woo; Choi, Chul Yung; Kim, Hyung Gyun; Lee, Gi Ho; Kim, Yong An; Chung, Young Chul; Jeong, Hye Gwang

    2017-01-18

    Capsaicin (CPS) exerts many pharmacological effects, but any possible influence on liver fibrosis remains unclear. Therefore, we evaluated the inhibitory effects of CPS on dimethylnitrosamine (DMN) and TGF-β1-induced liver fibrosis in rats and hepatic stellate cells (HSCs). CPS inhibited DMN-induced hepatotoxicity, NF-κB activation, and collagen accumulation. CPS also suppressed the DMN-induced increases in α-SMA, collagen type I, MMP-2, and TNF-α. In addition, CPS inhibited DMN-induced TGF-β1 expression (from 2.3 ± 0.1 to 1.0 ± 0.1) and Smad2/3 phosphorylation (from 1.5 ± 0.1 to 1.1 ± 0.1 and from 1.6 ± 0.1 to 1.1 ± 0.1, respectively) by activating Smad7 expression (from 0.1 ± 0.0 to 0.9 ± 0.1) via PPAR-γ induction (from 0.2 ± 0.0 to 0.8 ± 0.0) (p < 0.05). Furthermore, in HSCs, CPS inhibited the TGF-β1-induced increases in α-SMA and collagen type I expression, via PPAR-γ activation. These results indicate that CPS can ameliorate hepatic fibrosis by inhibiting the TGF-β1/Smad pathway via PPAR-γ activation.

  16. Rapid Increase in Serum Low-Density Lipoprotein Cholesterol Concentration during Hepatitis C Interferon-Free Treatment

    PubMed Central

    Abiru, Seigo; Komori, Atsumasa; Nagaoka, Shinya; Saeki, Akira; Uchida, Shinjiro; Bekki, Shigemune; Kugiyama, Yuki; Nagata, Kazuyoshi; Nakamura, Minoru; Migita, Kiyoshi; Nakao, Kazuhiko

    2016-01-01

    Background & Aim We performed lipid analyses at the early period of therapy in patients with chronic hepatitis C who underwent interferon (IFN)-free direct-acting antiviral (DAA) treatment, and we attempted to identify the factors that contributed to a rapid increase in the patients’ serum low-density lipoprotein cholesterol (LDL-C) concentration. Methods We retrospectively analyzed the cases of 100 consecutive patients with HCV infection treated at the National Hospital Organization Nagasaki Medical Center: 24 patients underwent daclatasvir (DCV) and asunaprevir (ASV) combination therapy (DCV/ASV) for 24 weeks, and the other 76 patients underwent ledipasvir and sofosbuvir combination therapy (LDV/SOF) for 12 weeks. ΔLDL-C was defined as the changed in LDL-C level at 28 days from the start of therapy. To determine whether ΔLDL-C was associated with several kinds of factors including viral kinetics, we performed a stepwise multiple linear regression analysis. Results The LDL-C levels in patients treated with LDV/SOF were markedly and significantly elevated (87.45 to 122.5 mg/dl; p<10−10) compared to those in the DCV/ASV-treated patients (80.15 to 87.8 mg/dl; p = 0.0056). The median levels of ΔLDL-C in the LDV/SOF and DCV/ASV groups were 33.2 and 13.1, respectively. LDV/SOF combination therapy as an IFN-free regimen (p<0.001) and ΔHCV core antigen (0–1 day drop) (p<0.044) were identified as independent factors that were closely related to the ΔLDL-C. Conclusions A rapid increase in the serum LDL-C concentration during the IFN-free treatment of hepatitis C was associated with the type of HCV therapy and a decline of HCV core protein. PMID:27680885

  17. Activity of purified hepatitis C virus protease NS3 on peptide substrates.

    PubMed Central

    Steinkühler, C; Urbani, A; Tomei, L; Biasiol, G; Sardana, M; Bianchi, E; Pessi, A; De Francesco, R

    1996-01-01

    The protease domain of the hepatitis C virus (HCV) protein NS3 was expressed in Escherichia coli, purified to homogeneity, and shown to be active on peptides derived from the sequence of the NS4A-NS4B junction. Experiments were carried out to optimize protease activity. Buffer requirements included the presence of detergent, glycerol, and dithiothreitol, pH between 7.5 and 8.5, and low ionic strength. C- and N-terminal deletion experiments defined a peptide spanning from the P6 to the P4' residue as a suitable substrate. Cleavage kinetics were subsequently measured by using decamer P6-P4' peptides corresponding to all intermolecular cleavage sites of the HCV polyprotein. The following order of cleavage efficiency, in terms of kcat/Km, was determined: NS5A-NS5B > NS4A-NS4B >> NS4B-NS5A. A 14-mer peptide containing residues 21 to 34 of the protease cofactor NS4A (Pep4A 21-34), when added in stoichiometric amounts, was shown to increase cleavage rates of all peptides, the largest effect (100-fold) being observed on the hydrolysis of the NS4B-NS5A decamer. From the kinetic analysis of cleavage data, we conclude that (i) primary structure is an important determinant of the efficiency with which each site is cleaved during polyprotein processing, (ii) slow cleavage of the NS4B-NS5A site in the absence of NS4A is due to low binding affinity of the enzyme for this site, and (iii) formation of a 1:1 complex between the protease and Pep4A 21-34 is sufficient and required for maximum activation. PMID:8794305

  18. Imipramine blocks ethanol-induced ASMase activation, ceramide generation, and PP2A activation, and ameliorates hepatic steatosis in ethanol-fed mice.

    PubMed

    Liangpunsakul, Suthat; Rahmini, Yasmeen; Ross, Ruth A; Zhao, Zhenwen; Xu, Yan; Crabb, David W

    2012-03-01

    Our previous data showed the inhibitory effect of ethanol on AMP-activated protein kinase phosphorylation, which appears to be mediated, in part, through increased levels of hepatic ceramide and activation of protein phosphatase 2A (Liangpunsakul S, Sozio MS, Shin E, Zhao Z, Xu Y, Ross RA, Zeng Y, Crabb DW. Am J Physiol Gastrointest Liver Physiol 298: G1004-G1012, 2010). The effect of ethanol on AMP-activated protein kinase phosphorylation was reversed by imipramine, suggesting that the generation of ceramide via acid sphingomyelinase (ASMase) is stimulated by ethanol. In this study, we determined the effects of imipramine on the development of hepatic steatosis, the generation of ceramide, and downstream effects of ceramide on inflammatory, insulin, and apoptotic signaling pathways, in ethanol-fed mice. The effect of ethanol and imipramine (10 μg/g body wt ip) on ceramide levels, as well as inflammatory, insulin, and apoptotic signaling pathways, was studied in C57BL/6J mice fed the Lieber-DeCarli diet. Ethanol-fed mice developed the expected steatosis, and cotreatment with imipramine for the last 2 wk of ethanol feeding resulted in improvement in hepatic steatosis. Ethanol feeding for 4 wk induced impaired glucose tolerance compared with controls, and this was modestly improved with imipramine treatment. There was a significant decrease in total ceramide concentrations in response to imipramine in ethanol-fed mice treated with and without imipramine (287 ± 11 vs. 348 ± 12 pmol/mg tissue). The magnitude and specificity of inhibition on each ceramide species differed. A significant decrease was observed for C16 (28 ± 3 vs. 33 ± 2 pmol/mg tissue) and C24 (164 ± 9 vs. 201 ± 4 pmol/mg tissue) ceramide. Ethanol feeding increased the levels of the phosphorylated forms of ERK slightly and increased phospho-p38 and phospho-JNK substantially. The levels of phospho-p38 and phospho-JNK were reduced by treatment with imipramine. The activation of ASMase and generation

  19. Mice expressing reduced levels of hepatic glucose-6-phosphatase-α activity do not develop age-related insulin resistance or obesity.

    PubMed

    Kim, Goo-Young; Lee, Young Mok; Cho, Jun-Ho; Pan, Chi-Jiunn; Jun, Hyun Sik; Springer, Danielle A; Mansfield, Brian C; Chou, Janice Y

    2015-09-15

    Glycogen storage disease type-Ia (GSD-Ia) is caused by a lack of glucose-6-phosphatase-α (G6Pase-α or G6PC) activity. We have shown that gene therapy mediated by a recombinant adeno-associated virus (rAAV) vector expressing human G6Pase-α normalizes blood glucose homeostasis in the global G6pc knockout (G6pc(-/-)) mice for 70-90 weeks. The treated G6pc(-/-) mice expressing 3-63% of normal hepatic G6Pase-α activity (AAV mice) produce endogenous hepatic glucose levels 61-68% of wild-type littermates, have a leaner phenotype and exhibit fasting blood insulin levels more typical of young adult mice. We now show that unlike wild-type mice, the lean AAV mice have increased caloric intake and do not develop age-related obesity or insulin resistance. Pathway analysis shows that signaling by hepatic carbohydrate response element binding protein that improves glucose tolerance and insulin signaling is activated in AAV mice. In addition, several longevity factors in the calorie restriction pathway, including the NADH shuttle systems, NAD(+) concentrations and the AMP-activated protein kinase/sirtuin 1/peroxisome proliferator-activated receptor-γ coactivator 1α pathway are upregulated in the livers of AAV mice. The finding that partial restoration of hepatic G6Pase-α activity in GSD-Ia mice not only attenuates the phenotype of hepatic G6Pase-α deficiency but also prevents the development of age-related obesity and insulin resistance seen in wild-type mice may suggest relevance of the G6Pase-α enzyme to obesity and diabetes.

  20. Gas6/Axl pathway is activated in chronic liver disease and its targeting reduces fibrosis via hepatic stellate cell inactivation

    PubMed Central

    Bárcena, Cristina; Stefanovic, Milica; Tutusaus, Anna; Joannas, Leonel; Menéndez, Anghara; García-Ruiz, Carmen; Sancho-Bru, Pau; Marí, Montserrat; Caballeria, Joan; Rothlin, Carla V.; Fernández-Checa, José C.; de Frutos, Pablo García; Morales, Albert

    2015-01-01

    Background & Aims Liver fibrosis, an important health concern associated to chronic liver injury that provides a permissive environment for cancer development, is characterized by accumulation of extracellular matrix components mainly derived from activated hepatic stellate cells (HSCs). Axl, a receptor tyrosine kinase, and its ligand Gas6 are involved in cell differentiation, immune response and carcinogenesis. Methods HSCs were obtained from wild type and Axl−/− mice, treated with recombinant Gas6 protein (rGas6), Axl siRNAs or the Axl inhibitor BGB324, and analyzed by western blot and real-time PCR. Experimental fibrosis was studied in CCl4-treated wild type and Axl−/− mice, and in combination with Axl inhibitor. Gas6 and Axl serum levels were measured in alcoholic liver disease (ALD) and hepatitis C virus (HCV) patients. Results In primary mouse HSCs, Gas6 and Axl levels paralleled HSC activation. rGas6 phosphorylated Axl and AKT prior to HSC phenotypic changes, while Axl siRNA silencing reduced HSC activation. Moreover, BGB324 blocked Axl/AKT phosphorylation and diminished HSC activation. In addition, Axl KO mice displayed decreased HSC activation in vitro and liver fibrogenesis after chronic damage by CCl4 administration. Similarly, BGB324 reduced collagen deposition and CCl4-induced liver fibrosis in mice. Importantly, Gas6 and Axl serum levels increased in ALD and HCV patients, inversely correlating with liver functionality. Conclusions: The Gas6/Axl axis is required for full HSC activation. Gas6 and Axl serum levels increase in parallel to chronic liver disease progression. Axl targeting may be a therapeutic strategy for liver fibrosis management. PMID:25908269

  1. Role of hypoxia-inducible factor-{alpha} in hepatitis-B-virus X protein-mediated MDR1 activation

    SciTech Connect

    Han, Hyo-Kyung; Han, Chang Yeob; Cheon, Eun-Pa; Lee, Jaewon; Kang, Keon Wook . E-mail: kwkang@chosun.ac.kr

    2007-06-01

    The transition from chemotherapy-responsive cancer cells to chemotherapy-resistant cancer cells is mainly accompanied by the increased expression of multi-drug resistance 1 (MDR1). We found that hepatitis-B-virus X protein (HBx) increases the transcriptional activity and protein level of MDR1 in a hepatoma cell line, H4IIE. In addition, HBx overexpression made H4IIE cells more resistant to verapamil-uptake. HBx stabilized hypoxia-inducible factor-1{alpha} (HIF-1{alpha}) and induced the nuclear translocation of C/EBP{beta}. Reporter gene analyses showed that HBx increased the reporter activity in the cells transfected with the reporter containing MDR1 gene promoter. Moreover, the luciferase reporter gene activity was significantly inhibited by HIF-1{alpha} siRNA but not by overexpression of C/EBP dominant negative mutant. These results imply that HBx increases the MDR1 transporter activity through the transcriptional activation of the MDR1 gene with HIF-1{alpha} activation, and suggest HIF-1{alpha} for the therapeutic target of HBV-mediated chemoresistance.

  2. Gut microbiota are linked to increased susceptibility to hepatic steatosis in low aerobic capacity rats fed an acute high fat diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poor aerobic fitness is linked to nonalcoholic fatty liver disease and increased all-cause mortality. We previously found that low capacity running (LCR) rats fed acute high fat diet (HFD; 45% kcal from fat) for 3 days resulted in positive energy balance and increased hepatic steatosis compared with...

  3. Increased hepatic VLDL secretion, lipogenesis, and SREBP-1 expression in the corpulent JCR:LA-cp rat.

    PubMed

    Elam, M B; Wilcox, H G; Cagen, L M; Deng, X; Raghow, R; Kumar, P; Heimberg, M; Russell, J C

    2001-12-01

    The corpulent JCR:LA-cp rat (cp/cp) is a useful model for study of the metabolic consequences of obesity and hyperinsulinemia. To assess the effect of hyperinsulinemia on VLDL secretion in this model, we measured rates of secretion of VLDL in perfused livers derived from cp/cp rats and their lean littermates. Livers of cp/cp rats secreted significantly greater amounts of VLDL triglyceride and apolipoprotein, compared with lean littermates. The content of apoB, apoE, and apoCs in both perfusate and plasma VLDL was greater in the cp/cp rat, as was the apolipoprotein (apo)C, apoA-I, and apoA-IV content of plasma HDL. Triglyceride content was also greater in cp/cp livers, as was hepatic lipogenesis and expression of lipogenic enzymes and sterol regulatory element binding protein-1 (SREBP-1). Hepatic mRNAs for apoE, and apoA-I were higher in livers of cp/cp rats. In contrast, the steady state levels of apoC-II, apoC-III, and apoB mRNAs were unchanged. Thus, livers of obese hyperinsulinemic cp/cp JCR:LA-cp rats secrete a greater number of VLDL particles that are enriched in triglyceride, apoE, and apoC. Greater secretion of VLDL in the cp/cp rat in part results from higher endogenous fatty acid synthesis, which in turn may occur in response to increased expression of the lipogenic enzyme regulator SREBP-1c.

  4. Hepatitis C Virus Increases Free Fatty Acids Absorption and Promotes its Replication Via Down-Regulating GADD45α Expression

    PubMed Central

    Chen, Wei; Li, Xiao-ming; Li, An-ling; Yang, Gui; Hu, Han-ning

    2016-01-01

    Background Hepatitis C virus (HCV) infection, as a major cause of chronic hepatic diseases, is always accompanied with an abnormality of lipid metabolism. The aim of this study was to investigate the pathogenic role of free fatty acids (FFA) in human HCV infection. Material/Methods Peripheral blood lipid indexes among HCV patients with different viral loads (199 samples) and healthy donors (80 samples) were detected by clinical biochemistry tests. HCV replication and the expression of growth arrest and DNA-damage-inducible gene 45-α (GADD45α) in Huh7 cells and clinical samples were quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Lipid accumulation in Huh7 cells was detected by immunofluorescence. Results In this study, we found that FFA showed a significant positive correlation with viral load in peripheral blood of HCV patients, but not total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), or low-density lipoprotein cholesterol (LDL-C). GADD45α expression in HCV patients dramatically decreased with the increase of viral load. In Huh7 cells, FFA treatment significantly enhanced HCV replication. HCV infection inhibited GADD45α expression, and this effect was further enhanced with the presence of FFA treatment. Ectopic expression of GADD45α in HCV-infected Huh7 cells markedly inhibited the absorption of FFA and HCV replication. However, FFA significantly elevated GADD45α expression without HCV infection. Conclusions These results demonstrated that HCV down-regulates GADD45α expression to enhance FFA absorption and thus facilitate its replication. GADD45α is an essential mediator for the pathogenesis of HCV infection. Thus, our study provides potential clues in the search for novel therapeutics and fatty lipid control options for HCV patients. PMID:27381636

  5. Increased Hepatitis E Virus Seroprevalence Correlates with Lower CD4+ Cell Counts in HIV-Infected Persons in Argentina

    PubMed Central

    Debes, José D.; Martínez Wassaf, Maribel; Pisano, María Belén; Isa, María Beatriz; Lotto, Martin; Marianelli, Leonardo G.; Frassone, Natalia; Ballari, Estefania; Bohjanen, Paul R.; Hansen, Bettina E.; Ré, Viviana

    2016-01-01

    Hepatitis E virus (HEV) is a single-stranded RNA virus that can cause hepatitis in an epidemic fashion. HEV usually causes asymptomatic or limited acute infections in immunocompetent individuals, whereas in immunosuppressed individuals such as transplant recipients, HEV can cause chronic infections. The risks and outcomes of HEV co-infection in patients infected with human immunodeficiency virus (HIV) are poorly characterized. We used a third generation immunoassay to measure serum IgG antibodies specific for HEV in 204 HIV-infected individuals from Argentina and a control group of 433 HIV-negative individuals. We found 15 of 204 (7.3%, 95%CI 3.74–10.96%) individuals in the HIV-positive group to have positive HEV IgG levels suggestive of previous infection, compared to 19 of 433 (4.4%, 95% CI 2.5–6.3%) individuals in the HIV-negative control group (p = 0.12). Among HIV-positive individuals, those with HEV seropositivity had lower CD4 counts compared to those that were HEV seronegative (average CD4 count of 234 vs 422 mm3, p = 0.01), indicating that patients with lower CD4 counts were more likely to be HEV IgG positive. Moreover, HEV seropositivity in patients with CD4 counts <200 mm3 was 16%, compared to 4.5% in those with CD4 counts >200 mm3 (p = 0.012). We found a positive PCR result for HEV in one individual. Our study found that increased seroprevalence of HEV IgG correlated with lower CD4 counts in HIV-infected patients in Argentina. PMID:27467394

  6. The Dual Role of Exosomes in Hepatitis A and C Virus Transmission and Viral Immune Activation.

    PubMed

    Longatti, Andrea

    2015-12-17

    Exosomes are small nanovesicles of about 100 nm in diameter that act as intercellular messengers because they can shuttle RNA, proteins and lipids between different cells. Many studies have found that exosomes also play various roles in viral pathogenesis. Hepatitis A virus (HAV; a picornavirus) and Hepatitis C virus (HCV; a flavivirus) two single strand plus-sense RNA viruses, in particular, have been found to use exosomes for viral transmission thus evading antibody-mediated immune responses. Paradoxically, both viral exosomes can also be detected by plasmacytoid dendritic cells (pDCs) leading to innate immune activation and type I interferon production. This article will review recent findings regarding these two viruses and outline how exosomes are involved in their transmission and immune sensing.

  7. The Dual Role of Exosomes in Hepatitis A and C Virus Transmission and Viral Immune Activation

    PubMed Central

    Longatti, Andrea

    2015-01-01

    Exosomes are small nanovesicles of about 100 nm in diameter that act as intercellular messengers because they can shuttle RNA, proteins and lipids between different cells. Many studies have found that exosomes also play various roles in viral pathogenesis. Hepatitis A virus (HAV; a picornavirus) and Hepatitis C virus (HCV; a flavivirus) two single strand plus-sense RNA viruses, in particular, have been found to use exosomes for viral transmission thus evading antibody-mediated immune responses. Paradoxically, both viral exosomes can also be detected by plasmacytoid dendritic cells (pDCs) leading to innate immune activation and type I interferon production. This article will review recent findings regarding these two viruses and outline how exosomes are involved in their transmission and immune sensing. PMID:26694453

  8. Regulation of Human Hepatic Drug Transporter Activity and Expression by Diesel Exhaust Particle Extract

    PubMed Central

    Le Vee, Marc; Jouan, Elodie; Stieger, Bruno; Lecureur, Valérie; Fardel, Olivier

    2015-01-01

    Diesel exhaust particles (DEPs) are common environmental air pollutants primarily affecting the lung. DEPs or chemicals adsorbed on DEPs also exert extra-pulmonary effects, including alteration of hepatic drug detoxifying enzyme expression. The present study was designed to determine whether organic DEP extract (DEPe) may target hepatic drug transporters that contribute in a major way to drug detoxification. Using primary human hepatocytes and transporter-overexpressing cells, DEPe was first shown to strongly inhibit activities of the sinusoidal solute carrier (SLC) uptake transporters organic anion-transporting polypeptides (OATP) 1B1, 1B3 and 2B1 and of the canalicular ATP-binding cassette (ABC) efflux pump multidrug resistance-associated protein 2, with IC50 values ranging from approximately 1 to 20 μg/mL and relevant to environmental exposure situations. By contrast, 25 μg/mL DEPe failed to alter activities of the SLC transporter organic cation transporter (OCT) 1 and of the ABC efflux pumps P-glycoprotein and bile salt export pump (BSEP), whereas it only moderately inhibited those of sodium taurocholate co-transporting polypeptide and of breast cancer resistance protein (BCRP). Treatment by 25 μg/mL DEPe was next demonstrated to induce expression of BCRP at both mRNA and protein level in cultured human hepatic cells, whereas it concomitantly repressed mRNA expression of various transporters, including OATP1B3, OATP2B1, OCT1 and BSEP. Such changes in transporter expression were found to be highly correlated to those caused by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a reference activator of the aryl hydrocarbon receptor (AhR) pathway. This suggests that DEPe, which is enriched in known ligands of AhR like polycyclic aromatic hydrocarbons, alters drug transporter expression via activation of the AhR cascade. Taken together, these data established human hepatic transporters as targets of organic chemicals containing in DEPs, which may contribute to their

  9. Aerobic exercise increases peripheral and hepatic insulin sensitivity in sedentary adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increasing prevalence of obesity and its consequences is a serious public health concern. The present study was undertaken to determine whether a controlled aerobic exercise program (without weight loss) improves insulin sensitivity and glucose metabolism in sedentary adolescents. Twenty nine p...

  10. Hepatitis B

    MedlinePlus

    ... Home » Hepatitis B » Hepatitis B Entire Lesson Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... Enter ZIP code here Enter ZIP code here Hepatitis B Entire Lesson for Veterans and the Public ...

  11. Activation of class I major histocompatibility complex gene expression by hepatitis B virus.

    PubMed Central

    Zhou, D X; Taraboulos, A; Ou, J H; Yen, T S

    1990-01-01

    Normal hepatocytes express very few class I major histocompatibility complex (MHC I) molecules, but MHC I expression is elevated in hepatitis B virus (HBV) infection. We report here that hepatoblastoma cells with replicating HBV genomes express three- to fourfold-higher levels of MHC I protein and mRNA than do parent cells without HBV DNA. Transient transfection assays demonstrated that the HBV X protein trans activated transcription from an MHC I promoter and allowed identification of cis elements important for trans activation. Images PMID:2164611

  12. Biological or pharmacological activation of protein kinase C alpha constrains hepatitis E virus replication.

    PubMed

    Wang, Wenshi; Wang, Yijin; Debing, Yannick; Zhou, Xinying; Yin, Yuebang; Xu, Lei; Herrera Carrillo, Elena; Brandsma, Johannes H; Poot, Raymond A; Berkhout, Ben; Neyts, Johan; Peppelenbosch, Maikel P; Pan, Qiuwei

    2017-04-01

    Although hepatitis E has emerged as a global health issue, there is limited knowledge of its infection biology and no FDA-approved medication is available. Aiming to investigate the role of protein kinases in hepatitis E virus (HEV) infection and to identify potential antiviral targets, we screened a library of pharmacological kinase inhibitors in a cell culture model, a subgenomic HEV replicon containing luciferase reporter. We identified protein kinase C alpha (PKCα) as an essential cell host factor restricting HEV replication. Both specific inhibitor and shRNA-mediated knockdown of PKCα enhanced HEV replication. Conversely, over-expression of the activated form of PKCα or treatment with its pharmacological activator strongly inhibited HEV replication. Interestingly, upon the stimulation by its activator, PKCα efficiently activates its downstream Activator Protein 1 (AP-1) pathway, leading to the induction of antiviral interferon-stimulated genes (ISGs). This process is independent of the JAK-STAT machinery and interferon production. However, PKCα induced HEV inhibition appears independent of the AP1 cascade. The discovery that activated PKCα restricts HEV replication reveals new insight of HEV-host interactions and provides new target for antiviral drug development.

  13. Loss of ULK1 increases RPS6KB1-NCOR1 repression of NR1H/LXR-mediated Scd1 transcription and augments lipotoxicity in hepatic cells

    PubMed Central

    Sinha, Rohit Anthony; Singh, Brijesh K.; Zhou, Jin; Xie, Sherwin; Farah, Benjamin L.; Lesmana, Ronny; Ohba, Kenji; Tripathi, Madhulika; Ghosh, Sujoy; Hollenberg, Anthony N.; Yen, Paul M.

    2017-01-01

    ABSTRACT Lipotoxicity caused by saturated fatty acids (SFAs) induces tissue damage and inflammation in metabolic disorders. SCD1 (stearoyl-coenzyme A desaturase 1) converts SFAs to mono-unsaturated fatty acids (MUFAs) that are incorporated into triglycerides and stored in lipid droplets. SCD1 thus helps protect hepatocytes from lipotoxicity and its reduced expression is associated with increased lipotoxic injury in cultured hepatic cells and mouse models. To further understand the role of SCD1 in lipotoxicity, we examined the regulation of Scd1 in hepatic cells treated with palmitate, and found that NR1H/LXR (nuclear receptor subfamily 1 group H) ligand, GW3965, induced Scd1 expression and lipid droplet formation to improve cell survival. Surprisingly, ULK1/ATG1 (unc-51 like kinase) played a critical role in protecting hepatic cells from SFA-induced lipotoxicity via a novel mechanism that did not involve macroautophagy/autophagy. Specific loss of Ulk1 blocked the induction of Scd1 gene transcription by GW3965, decreased lipid droplet formation, and increased apoptosis in hepatic cells exposed to palmitate. Knockdown of ULK1 increased RPS6KB1 (ribosomal protein S6 kinase, polypeptide 1) signaling that, in turn, induced NCOR1 (nuclear receptor co-repressor 1) nuclear uptake, interaction with NR1H/LXR, and recruitment to the Scd1 promoter. These events abrogated the stimulation of Scd1 gene expression by GW3965, and increased lipotoxicity in hepatic cells. In summary, we have identified a novel autophagy-independent role of ULK1 that regulates NR1H/LXR signaling, Scd1 expression, and intracellular lipid homeostasis in hepatic cells exposed to a lipotoxic environment. PMID:27846372

  14. Increased hepatic Fatty Acid uptake and esterification contribute to tetracycline-induced steatosis in mice.

    PubMed

    Choi, You-Jin; Lee, Chae-Hyeon; Lee, Kang-Yo; Jung, Seung-Hwan; Lee, Byung-Hoon

    2015-06-01

    Tetracycline induces microvesicular steatosis, which has a poor long-term prognosis and a higher risk of steatohepatitis development compared with macrovesicular steatosis. Recent gene expression studies indicated that tetracycline treatment affects the expression of many genes associated with fatty acid transport and esterification. In this study, we investigated the role of fatty acid transport and esterification in tetracycline-induced steatosis. Intracellular lipid accumulation and the protein expression of fatty acid translocase (FAT or CD36) and diacylglycerol acyltransferase (DGAT) 2 were increased in both mouse liver and HepG2 cells treated with tetracycline at 50 mg/kg (intraperitoneal injection, i.p.) and 100 μM, respectively. Tetracycline increased the cellular uptake of boron-dipyrromethene-labeled C16 fatty acid, which was abolished by CD36 RNA interference. Oleate-induced cellular lipid accumulation was further enhanced by co-incubation with tetracycline. Tetracycline downregulated extracellular signal-regulated kinase (ERK) phosphorylation, which negatively regulated DGAT2 expression. U0126, a specific ERK inhibitor, also increased DGAT2 expression and cellular lipid accumulation. DGAT1 and 2 knock-down with specific small interfering (si)-RNA completely abrogated the steatogenic effect of tetracycline in HepG2 cells. Taken together, our data showed that tetracycline induces lipid accumulation by facilitating fatty acid transport and triglyceride esterification by upregulating CD36 and DGAT2, respectively.

  15. Blocking Notch signal in myeloid cells alleviates hepatic ischemia reperfusion injury by repressing the activation of NF-κB through CYLD

    PubMed Central

    Yu, Heng-Chao; Bai, Lu; Yang, Zhao-Xu; Qin, Hong-Yan; Tao, Kai-Shan; Han, Hua; Dou, Ke-Feng

    2016-01-01

    Ischemia-reperfusion (I/R) is a major reason of hepatocyte injury during liver surgery and transplantation. Myeloid cells including macrophages and neutrophils play important roles in sustained tissue inflammation and damage, but the mechanisms regulating myeloid cells activity have been elusive. In this study, we investigate the role of Notch signaling in myeloid cells during hepatic I/R injury by using a mouse model of myeloid specific conditional knockout of RBP-J. Myeloid-specific RBP-J deletion alleviated hepatic I/R injury. RBP-J deletion in myeloid cells decreased hepatocytes apoptosis after hepatic I/R injury. Furthermore, myeloid-specific RBP-J deletion led to attenuated inflammation response in liver after I/R injury. Consistently, Notch blockade reduced the production of inflammatory cytokines by macrophages in vitro. We also found that blocking Notch signaling reduced NF-κB activation and increased cylindromatosis (CYLD) expression and knockdown of CYLD rescued reduction of inflammatory cytokines induced by Notch blockade in macrophages during I/R injury in vitro. On the other hand, activation of Notch signaling in macrophages led to increased inflammatory cytokine production and NF-κB activation and decreased CYLD expression in vitro. These data suggest that activation of Notch signaling in myeloid cells aggravates I/R injury, by enhancing the inflammation response by NF-κB through down regulation of CYLD. PMID:27680285

  16. Physical properties, lipid composition and enzyme activities of hepatic subcellular membranes from chick embryo after ethanol treatment

    SciTech Connect

    Sanchez-Amate, M.C.; Marco, C.; Segovia, J.L. )

    1992-01-01

    Exposure of chick embryos to ethanol resulted in significant alterations to the lipid composition of various different hepatic subcellular membranes. A marked decrease in cholesterol levels and an increase in the phospholipid content of microsomes and mitochondria was observed. Ethanol also affected the fatty acid profiles, mainly by decreasing the percentage of oleic acid in phosphatidylcholine and phosphatidylethanolamine in the mitochondria and phosphatidylethanolamine in the microsomes. In spite of these changes ethanol only induced alterations in the fluidity of the mitochondrial membranes, which showed a more rigid core, in contrast to the phospholipid-head region, which was not affected. In accordance with the changes observed in the physical state of the membrane, the enzymes involved in the microsomal electron-transport systems were not modified by ethanol, while cytochrome oxidase activity decreased by 50% compared to the activity in the mitochondria from control chick embryos.

  17. SENESCENCE-ASSOCIATED DECLINE IN HEPATIC PEROXISOMAL ENZYME ACTIVITIES CORRESPONDS WITH DIMINISHED LEVELS OF RETINOID X RECEPTOR ALPHA, BUT NOT PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA1

    EPA Science Inventory

    Abstract

    Aging is associated with alterations in hepatic peroxisomal metabolism and susceptibility to hepatocarcinogenecity produced by agonists of peroxisome proliferator-activated receptor alpha (PPARa). Mechanisms involved in these effects are not well understood. Howev...

  18. Dried chicory root modifies the activity and expression of porcine hepatic CYP3A but not 2C--effect of in vitro and in vivo exposure.

    PubMed

    Rasmussen, Martin Krøyer; Zamaratskaia, Galia; Andersen, Bente; Ekstrand, Bo

    2012-11-01

    Hepatic cytochrome P450 expression and activity are dependent on many factors, including dietary ingredients. In the present study, we investigated the in vivo and in vitro effect of chicory root on hepatic CYP3A and 2C in male pigs. Chicory feeding increased the expression of CYP3A29 mRNA but not CYP2C33. Correspondingly, CYP3A activity was increased by chicory feeding, while CYP2C activity was not affected. Additionally, the in vitro effect of chicory extract on the CYP3A activity was investigated. It was shown that CYP3A activity in the microsomes from male pigs was inhibited, but this effect was eliminated by pre-incubation. In both male and female pigs the CYP3A activity was increased in the presence of chicory after pre-incubation. Furthermore, gender-related differences in mRNA expression and activity were observed. CYP3A mRNA expression was greater in female pigs; this was not reflected on activity. For CYP2C, no difference in mRNA expression was observed, while CYP2C activity was greater in female pigs. Surprisingly, the expression of the constitutive androstane receptor, pregnane X receptor and aryl hydrocarbon receptor did not differ with feed or gender. In conclusion, chicory root modifies the expression and activity of CYP3A in vivo and in vitro, while CYP2C is not affected.

  19. Trans-stilbene oxide administration increased hepatic glucuronidation of morphine but decreased biliary excretion of morphine glucuronide in rats

    SciTech Connect

    Fuhrman-Lane, C.; Fujimoto, J.M.

    1982-09-01

    The effect of the inducing agent trans-stilbene oxide (TSO) on the metabolism and biliary excretion of (/sup 14/C)morphine was studied in the isolated in situ perfused rat liver. After administration of morphine by intraportal injection or by the segmented retrograde intrabiliary injection technique, the TSO-treated group showed a marked decrease in the biliary recovery of morphine as its glucuronide conjugate (morphine-3-glucuronide (MG)). However, recovery of MG in the venous outflow of the single pass perfusate was greatly increased. These findings suggested that TSO treatment enhanced the formation of MG from morphine and changed the primary route of hepatic elimination of MG. TSO treatment also decreased the excretion of morphine (as MG) in the bile of anesthetized renal-ligated rats. This decreased biliary function required several days to develop and appeared closely associated with the inductive effect of TSO. After i.v. administration of (/sup 14/C)MG itself, biliary recovery was also markedly decreased in TSO-treated rats. It is postulated that the effect of the TSO treatment led to either a decrease in canalicular transport of MG into bile or an increase in the efficiency of transfer of MG to the blood at the sinusoidal side of the hepatocyte. Regardless of the mechanism, the results indicate the need to study compartmentalization of drug transport and metabolism functions.

  20. HIV Infection of Hepatocytes Results in a Modest Increase in Hepatitis C Virus Expression In Vitro

    PubMed Central

    Kong, Ling; Welge, Jeffrey A.; Powell, Eleanor A.; Blackard, Jason T.

    2014-01-01

    Previous studies demonstrate that soluble HIV proteins impact both hepatocyte function and HCV replication in vitro. It has also been reported that HIV can productively infect hepatocytes. We therefore investigated the impact of HIV infection of hepatocytes on HCV expression. The Huh7.5JFH1 cell line that constitutively expresses infectious HCV was infected with the lab-adapted strains HIVNL4-3 or HIVYK-JRCSF. HCV expression was quantified via HCV core antigen ELISA, Western blot, and strand-specific real-time PCR for positive-sense and negative-sense HCV RNA. After HIVNL4-3 infection of Huh7.5JFH1 cells, positive-sense and negative-sense HCV RNA levels were elevated compared to HIV uninfected cells. Increased HCV RNA synthesis was also observed after infection of Huh7.5JFH1 cells with HIVYK-JRCSF. HIV-induced HCV core production was decreased in the presence of the anti-HIV drugs AZT, T20, and raltegravir, although these medications had a minimal effect on HCV expression in the absence of HIV. HCV core, NS3, and NS5A protein expression were increased after HIV infection of Huh7.5JFH1 cells. Chemically inactivated HIV had a minimal effect on HCV expression in Huh7.5JFH1 cells suggesting that ongoing viral replication was critical. These data demonstrate that HIV induces HCV RNA synthesis and protein production in vitro and complement previous in vivo reports that HCV RNA levels are elevated in individuals with HIV/HCV co-infection compared to those with HCV mono-infection. These findings suggest that HIV suppression may be a critical factor in controlling liver disease, particularly if the underlying liver disease is not treated. PMID:24586227

  1. Activities of the enzymes of hepatic gluconeogenesis in periparturient dairy cows with induced fatty liver.

    PubMed

    Murondoti, Absolom; Jorritsma, Ruurd; Beynen, Anton C; Wensing, Theo; Geelen, Math J H

    2004-05-01

    The objective was to measure the activities of all the enzymes essential for hepatic gluconeogenesis in dairy cows with induced fatty liver. We aimed to induce severe fatty liver in ten experimental cows by overfeeding them during the dry period while seven control cows were maintained on a restricted diet. To induce a marked negative energy balance, the experimental cows were deprived of feed for 8 h immediately after parturition. In addition, the experimental cows were given a restricted amount of diet during the first 5 d of lactation. Liver samples were collected 1 week before and 1, 2 and 4 weeks after parturition. Before parturition, liver triacylglycerol concentrations did not differ between the two groups. After parturition, the experimental cows developed marked fatty liver as indicated by a higher level of triacylglycerols in the liver compared with the control cows. Before parturition, all gluconeogenic enzymes in the liver were lower in experimental cows than in control cows. Phosphoenolpyruvate carboxykinase, pyruvate carboxylase and propionyl-CoA carboxylase were significantly lower and fructose 1,6-bisphosphatase and glucose 6-phosphatase tended to be lower in the experimental cows. The activities of two crucial enzymes for gluconeogenesis in ruminants, i.e., phosphoenolpyruvate carboxykinase and propionyl-CoA carboxylase, remained low throughout the sampling period post partum. Activities of pyruvate carboxylase and glucose 6-phosphatase in the experimental cows post partum were upgraded to values similar to those of the control cows. The results showed that the capacity for hepatic gluconeogenesis before parturition was lower in cows with induced fatty liver than in control cows. After parturition, the low activities of crucial gluconeogenic enzymes indicated insufficient production of glucose. It is suggested that the low gluconeogenic capacity leads successively to low blood glucose concentrations, low insulin levels and high rates of

  2. Circulating lysosomal enzymes and acute hepatic necrosis.

    PubMed Central

    Gove, C D; Wardle, E N; Williams, R

    1981-01-01

    The activities of the lysosomal enzymes acid and neutral protease, N-acetylglucosaminidase, and acid phosphatase were measured in the serum of patients with fulminant hepatic failure. Acid protease (cathepsin D) activity was increased about tenfold in patients who died and nearly fourfold in those who survived fulminant hepatic failure after paracetamol overdose, whereas activities were increased equally in patients with fulminant hepatic failure due to viral hepatitis whether or not they survived. A correlation was found between serum acid protease activity and prothrombin time, and the increase in cathepsin D activity was sustained over several days compared with aspartate aminotransferase, which showed a sharp early peak and then a fall. Circulating lysosomal proteases can damage other organs, and measurement of their activity may therefore be of added value in assessing prognosis in this condition. PMID:7007443

  3. Preventive activity of banana peel polyphenols on CCl4-induced experimental hepatic injury in Kunming mice

    PubMed Central

    WANG, RUI; FENG, XIA; ZHU, KAI; ZHAO, XIN; SUO, HUAYI

    2016-01-01

    The aim of the present study was to evaluate the preventive effects of banana peel polyphenols (BPPs) against hepatic injury. Mice were divide into normal, control, 100 mg/kg and 200 mg/kg banana peel polyphenol and silymarin groups. All the mice except normal mice were induced with hepatic damage using CCl4. The serum and tissue levels of mice were determined by a kit and the tissues were further examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. BPPs reduced the serum levels of aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase in a CCl4-induced mouse model of hepatic injury. Furthermore, BPPs reduced the levels of malondialdehyde and triglyceride, while increasing glutathione levels in the serum and liver tissues of mice. In addition, the effects of 200 mg/kg treatment were more evident, and these effects were comparable to those of the drug silymarin. Serum levels of the cytokines, interleukin (IL)-6, IL-12, tumor necrosis factor (TNF)-α and interferon-γ, were reduced in the mice treated with BPPs compared with injury control group mice, and these levels were comparable to those of the normal and silymarin-treated groups. Histopathological examination indicated that BPPs were able to reduce the extent of CCl4-induced liver tissue injury and protect the liver cells. Furthermore, the mRNA and protein expression levels of the inflammation-associated factors cyclooxygenase-2, nitric oxide synthase, TNF-α and IL-1β were reduced in mice treated with BPPs compared with the control group mice. Mice that received 200 mg/kg BPP exhibited reduced expression levels of these factors compared with mice that received 100 mg/kg BPP. In conclusion, the results of the present study suggested that BPPs exert a good preventive effect against hepatic injury. PMID:27168833

  4. Lipopolysaccharide, immune activation, and liver abnormalities in HIV/hepatitis B virus (HBV)-coinfected individuals receiving HBV-active combination antiretroviral therapy.

    PubMed

    Crane, Megan; Avihingsanon, Anchalee; Rajasuriar, Reena; Velayudham, Pushparaj; Iser, David; Solomon, Ajantha; Sebolao, Baotuti; Tran, Andrew; Spelman, Tim; Matthews, Gail; Cameron, Paul; Tangkijvanich, Pisit; Dore, Gregory J; Ruxrungtham, Kiat; Lewin, Sharon R

    2014-09-01

    We investigated the relationship between microbial translocation, immune activation, and liver disease in human immunodeficiency virus (HIV)/hepatitis B virus (HBV) coinfection. Lipopolysaccharide (LPS), soluble CD14, CXCL10, and CCL-2 levels were elevated in patients with HIV/HBV coinfection. Levels of LPS, soluble CD14, and CCL-2 declined following receipt of HBV-active combination antiretroviral therapy (cART), but the CXCL10 level remained elevated. No markers were associated with liver disease severity on liver biopsy (n = 96), but CXCL10, interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor α, and interferon γ (IFN-γ) were all associated with elevated liver enzyme levels during receipt of HBV-active cART. Stimulation of hepatocyte cell lines in vitro with IFN-γ and LPS induced a profound synergistic increase in the production of CXCL10. LPS may contribute to liver disease via stimulating persistent production of CXCL10.

  5. The Efficacy of Social Role Models to Increase Motivation to Obtain Vaccination against Hepatitis B among Men Who Have Sex with Men

    ERIC Educational Resources Information Center

    Vet, R.; de Wit, J. B. F.; Das, E.

    2011-01-01

    This study assessed the effects of role models in persuasive messages about risk and social norms to increase motivation to obtain hepatitis B virus (HBV) vaccination in men who have sex with men (MSM). MSM at risk for HBV in The Netherlands (N = 168) were recruited online via a range of websites and were randomly assigned to one of four…

  6. Increased phosphoenolpyruvate carboxykinase gene expression and steatosis during hepatitis C virus subgenome replication: role of nonstructural component 5A and CCAAT/enhancer-binding protein β.

    PubMed

    Qadri, Ishtiaq; Choudhury, Mahua; Rahman, Shaikh Mizanoor; Knotts, Trina A; Janssen, Rachel C; Schaack, Jerome; Iwahashi, Mieko; Puljak, Livia; Simon, Francis R; Kilic, Gordan; Fitz, J Gregory; Friedman, Jacob E

    2012-10-26

    Chronic hepatitis C virus (HCV) infection greatly increases the risk for type 2 diabetes and nonalcoholic steatohepatitis; however, the pathogenic mechanisms remain incompletely understood. Here we report gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PEPCK) transcription and associated transcription factors are dramatically up-regulated in Huh.8 cells, which stably express an HCV subgenome replicon. HCV increased activation of cAMP response element-binding protein (CREB), CCAAT/enhancer-binding protein (C/EBPβ), forkhead box protein O1 (FOXO1), and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and involved activation of the cAMP response element in the PEPCK promoter. Infection with dominant-negative CREB or C/EBPβ-shRNA significantly reduced or normalized PEPCK expression, with no change in PGC-1α or FOXO1 levels. Notably, expression of HCV nonstructural component NS5A in Huh7 or primary hepatocytes stimulated PEPCK gene expression and glucose output in HepG2 cells, whereas a deletion in NS5A reduced PEPCK expression and lowered cellular lipids but was without effect on insulin resistance, as demonstrated by the inability of insulin to stimulate mobilization of a pool of insulin-responsive vesicles to the plasma membrane. HCV-replicating cells demonstrated increases in cellular lipids with insulin resistance at the level of the insulin receptor, increased insulin receptor substrate 1 (Ser-312), and decreased Akt (Ser-473) activation in response to insulin. C/EBPβ-RNAi normalized lipogenic genes sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor γ, and liver X receptor α but was unable to reduce accumulation of triglycerides in Huh.8 cells or reverse the increase in ApoB expression, suggesting a role for increased lipid retention in steatotic hepatocytes. Collectively, these data reveal an important role of NS5A, C/EBPβ, and pCREB in promoting HCV-induced gluconeogenic gene expression

  7. Factors associated with increased incidence of severe toxicities following yttrium-90 resin microspheres in the treatment of hepatic malignancies

    PubMed Central

    Roberson II, John D; McDonald, Andrew M; Baden, Craig J; Lin, Chee Paul; Jacob, Rojymon; Burnett III, Omer L

    2016-01-01

    AIM: To further define variables associated with increased incidences of severe toxicities following administration of yttrium-90 (90Y) microspheres. METHODS: Fifty-eight patients undergoing 79 treatments were retrospectively assessed for development of clinical and laboratory toxicity incidence following 90Y administration. Severe toxicity events were defined using Common Terminology Criteria for Adverse Events version 4.03 and defined as grade ≥ 3. Univariate logistic regression analyses were used to evaluate the effect of different factors on the incidence of severe toxicity events. Multicollinearity was assessed for all factors with P < 0.1 using Pearson correlation matrices. All factors not excluded due to multicollinearity were included in a multivariate logistic regression model for each measurement of severe toxicity. RESULTS: Severe (grade ≥ 3) toxicities occurred following 21.5% of the 79 treatments included in our analysis. The most common severe laboratory toxicities were severe alkaline phosphatase (17.7%), albumin (12.7%), and total bilirubin (10.1%) toxicities. Decreased pre-treatment albumin (OR = 26.2, P = 0.010) and increased pre-treatment international normalized ratio (INR) (OR = 17.7, P = 0.048) were associated with development of severe hepatic toxicity. Increased pre-treatment aspartate aminotransferase (AST; OR = 7.4, P = 0.025) and decreased pre-treatment hemoglobin (OR = 12.5, P = 0.025) were associated with severe albumin toxicity. Increasing pre-treatment model for end-stage liver disease (MELD) score (OR = 1.8, P = 0.033) was associated with severe total bilirubin toxicity. Colorectal adenocarcinoma histology was associated with severe alkaline phosphatase toxicity (OR = 5.4, P = 0.043). CONCLUSION: Clinicians should carefully consider pre-treatment albumin, INR, AST, hemoglobin, MELD, and colorectal histology when choosing appropriate candidates for 90Y microsphere therapy. PMID:26973396

  8. Suppression of hepatic stellate cell activation through downregulation of gremlin1 expression by the miR-23b/27b cluster

    PubMed Central

    Wang, Hu; Ni, Yi-Ran; Wang, Jie; Wu, Jiang-Feng; Liu, Chang-Bai

    2016-01-01

    The imbalance between transforming growth factor β and bone morphogenetic protein 7 signaling pathways is a critical step in promoting hepatic stellate cell activation during hepatic fibrogenesis. Gremlin1 may impair the balance. Something remains unclear about the regulatory mechanisms of gremlin1 action on hepatic stellate cell activation and hepatic fibrosis. In the current study, gremlin1 overexpression promotes activation of hepatic stellate cells. Knockdown of gremlin1 with siRNAs suppresses hepatic stellate cell activation and attenuates hepatic fibrosis in rat model. Our results also show that miR-23b/27b cluster members bind to 3′-untranslated region of gremlin1 resulting in reduction of transforming growth factor β, α-smooth muscle actin and collagenI α1/2 gene expression. Our findings suggest that gremlin1 promotes hepatic stellate cell activation and hepatic fibrogenesis through impairment of the balance between transforming growth factor β and bone morphogenetic protein 7 signaling pathways. The miR-23b/27b cluster suppresses activation of hepatic stellate cells through binding gremlin1 to rectify the imbalance. PMID:27863390

  9. The Older Woman: Increased Psychosocial Benefits from Physical Activity.

    ERIC Educational Resources Information Center

    Wakat, Diane; Odom, Sarah

    1982-01-01

    Older women who participate in physical activity programs find physical benefits in the improvement of cardiovascular and musculoskeletal systems. The psychosocial benefits which result from physical activity include an increase in self-esteem, increased social contacts, a counteraction to depression, and improved stress management. Suggestions…

  10. Differential effects of fenofibrate or simvastatin treatment of rats on hepatic microsomal overt and latent diacylglycerol acyltransferase activities.

    PubMed

    Waterman, Ian J; Zammit, Victor A

    2002-06-01

    Hepatic triacylglycerol secretion is elevated in insulin-resistant states. Microsomal diacylglycerol acyltransferase (DGAT) catalyzes the final reaction in the synthesis of triacylglycerol (TAG). We have previously described two DGAT activities in rat liver microsomes, one overt (cytosol-facing) and one latent (endoplasmic reticulum lumen-facing) (Owen MR, Corstorphine CG, Zammit VA: Overt and latent activities of diacylglycerol acytransferase in rat liver microsomes: possible roles in very-low-density lipoprotein triacylglycerol secretion. Biochem J 323:17-21, 1977). It was suggested that they are involved in the synthesis of TAG for the cytosolic droplet and VLDL lipidation, respectively. In the present study, we measured the overt and latent DGAT activities in rats fed diets containing one of two hypolipidemic drugs: fenofibrate (a peroxisome proliferator-activated receptor alpha [PPARalpha] agonist) and simvastatin (a 3-hydroxy-3-methylglutaryl [HMG]-CoA reductase inhibitor). We found that the activities of the two DGATs could be varied independently by these treatments. Fenofibrate raised overt DGAT activity but lowered that of latent DGAT. In contrast, simvastatin markedly lowered overt DGAT activity without affecting that of latent DGAT. The increase in overt DGAT activity induced by fenofibrate could not be mimicked by feeding a diet enriched in n-3 polyunsaturated fatty acids (PUFA), which lowered overt DGAT activity but did not affect latent DGAT, suggesting that n-3 PUFA act through a mechanism independent of PPARalpha activation. The fibrate-induced increase in overt DGAT activity and the inhibition of latent DGAT may provide a mechanism through which acyl moieties are retained within the liver for oxidation through the pathways concomitantly upregulated by PPARalpha activation.

  11. Endurance exercise training increases APPL1 expression and improves insulin signaling in the hepatic tissue of diet-induced obese mice, independently of weight loss.

    PubMed

    Marinho, R; Ropelle, E R; Cintra, D E; De Souza, C T; Da Silva, A S R; Bertoli, F C; Colantonio, E; D'Almeida, V; Pauli, J R

    2012-07-01

    Hepatic insulin resistance is the major contributor to fasting hyperglycemia in type 2 diabetes. The protein kinase Akt plays a central role in the suppression of gluconeogenesis involving forkhead box O1 (Foxo1) and peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1α), and in the control of glycogen synthesis involving the glycogen synthase kinase beta (GSK3β) in the liver. It has been demonstrated that endosomal adaptor protein APPL1 interacts with Akt and blocks the association of Akt with its endogenous inhibitor, tribbles-related protein 3 (TRB3), improving the action of insulin in the liver. Here, we demonstrated that chronic exercise increased the basal levels and insulin-induced Akt serine phosphorylation in the liver of diet-induced obese mice. Endurance training was able to increase APPL1 expression and the interaction between APPL1 and Akt. Conversely, training reduced both TRB3 expression and TRB3 and Akt association. The positive effects of exercise on insulin action are reinforced by our findings that showed that trained mice presented an increase in Foxo1 phosphorylation and Foxo1/PGC-1α association, which was accompanied by a reduction in gluconeogenic gene expressions (PEPCK and G6Pase). Finally, exercised animals demonstrated increased at basal and insulin-induced GSK3β phosphorylation levels and glycogen content at 24 h after the last session of exercise. Our findings demonstrate that exercise increases insulin action, at least in part, through the enhancement of APPL1 and the reduction of TRB3 expression in the liver of obese mice, independently of weight loss.

  12. Best Practices and Recommendations for Increasing Physical Activity in Youth

    ERIC Educational Resources Information Center

    Erwin, Heather; Beets, Michael W.; Centeio, Erin; Morrow, James R., Jr.

    2014-01-01

    Many efforts to increase the physical activity levels of Americans have been introduced and implemented over the past 20 years. National Physical Activity Guidelines have been established, and the National Physical Activity Plan (NPAP) is now in place, which includes a specific sector dedicated to education. This article addresses the Education…

  13. School-Based Health Promotion Initiative Increases Children's Physical Activity

    ERIC Educational Resources Information Center

    Cluss, Patricia; Lorigan, Devin; Kinsky, Suzanne; Nikolajski, Cara; McDermott, Anne; Bhat, Kiran B.

    2016-01-01

    Background: Childhood obesity increases health risk, and modest physical activity can impact that risk. Schools have an opportunity to help children become more active. Purpose: This study implemented a program offering extra school-day activity opportunities in a rural school district where 37% of students were obese or overweight in 2005 and…

  14. Alterations in hepatic mixed-function oxidase activity of rainbow trout after acute treatment with polybrominated biphenyl isomers and FireMaster BP-6.

    PubMed

    Franklin, R B; Vodicnik, M J; Elcombe, C R; Lech, J J

    1981-05-01

    The effects of FireMaster BP-6 and several pure isomers on hepatic microsomal mixed-function oxidase (MFO) activity in rainbow trout have been investigated. After one parenteral injection of these agents at 150 mg/kg and sacrifice 5 d later, there was no elevation of hepatic cytochrome P-450. The noncoplanar isomers 2,4,5,2',4',5'-hexa and 2,3,4,5,2',4',5'-heptabromobiphenyl did not increase any MFO activity generally associated with an increase in cytochrome P-450 levels, including the dealkylations of ethoxycoumarin and benzphetamine. The coplanar isomer 3,4,5,3',4',5'-hexabromobiphenyl produced an increase in O-deethylation of both ethoxycoumarin and ethoxyresorufin, suggesting enhancement of cytochrome P-448 associated activity, but produced no increase in benzphetamine N-dealkylation. The "mixed inducer" 2,4,5,3',4',5'-hexabromobiphenyl, produced a small but insignificant elevation of cytochrome P-448 associated MFO activities and no increase in cytochrome P-450 associated activities. At both 150 and 500 mg/kg, the commercial mixture of polybrominated biphenyls FireMaster BP-6 produced marked elevations of both ethoxycoumarin and ethoxy-resorufin dealkylations but had no effect on demethylation of benzphetamine. When microsomes from rainbow trout treated with FireMaster BP-6 were examined electrophoretically, A coomassie Blue-staining band at 57,000 daltons was intensified, as seen after treatment of fish with the cytochrome P-448 inducer beta-naphthoflavone. It is concluded that coplanar polybrominated isomers produce an induction of hepatic cytochrome P-448 associated activity, while noncoplanar isomers are ineffective as inducers of cytochrome P-450 related MFO activities in rainbow trout.

  15. Melatonin acts through MT1/MT2 receptors to activate hypothalamic Akt and suppress hepatic gluconeogenesis in rats.

    PubMed

    Faria, Juliana A; Kinote, Andrezza; Ignacio-Souza, Letícia M; de Araújo, Thiago M; Razolli, Daniela S; Doneda, Diego L; Paschoal, Lívia B; Lellis-Santos, Camilo; Bertolini, Gisele L; Velloso, Lício A; Bordin, Silvana; Anhê, Gabriel F

    2013-07-15

    Melatonin can contribute to glucose homeostasis either by decreasing gluconeogenesis or by counteracting insulin resistance in distinct models of obesity. However, the precise mechanism through which melatonin controls glucose homeostasis is not completely understood. Male Wistar rats were administered an intracerebroventricular (icv) injection of melatonin and one of following: an icv injection of a phosphatidylinositol 3-kinase (PI3K) inhibitor, an icv injection of a melatonin receptor (MT) antagonist, or an intraperitoneal (ip) injection of a muscarinic receptor antagonist. Anesthetized rats were subjected to pyruvate tolerance test to estimate in vivo glucose clearance after pyruvate load and in situ liver perfusion to assess hepatic gluconeogenesis. The hypothalamus was removed to determine Akt phosphorylation. Melatonin injections in the central nervous system suppressed hepatic gluconeogenesis and increased hypothalamic Akt phosphorylation. These effects of melatonin were suppressed either by icv injections of PI3K inhibitors and MT antagonists and by ip injection of a muscarinic receptor antagonist. We conclude that melatonin activates hypothalamus-liver communication that may contribute to circadian adjustments of gluconeogenesis. These data further suggest a physiopathological relationship between the circadian disruptions in metabolism and reduced levels of melatonin found in type 2 diabetes patients.

  16. Hepatic triacylglycerol hydrolysis regulates peroxisome proliferator-activated receptor alpha activity.

    PubMed

    Sapiro, Jessica M; Mashek, Mara T; Greenberg, Andrew S; Mashek, Douglas G

    2009-08-01

    Recent evidence suggests that fatty acids generated from intracellular triacylglycerol (TAG) hydrolysis may have important roles in intracellular signaling. This study was conducted to determine if fatty acids liberated from TAG hydrolysis regulate peroxisome proliferator-activated receptor alpha (PPARalpha). Primary rat hepatocyte cultures were treated with adenoviruses overexpressing adipose differentiation-related protein (ADRP) or adipose triacylglycerol lipase (ATGL) or treated with short interfering RNA (siRNA) targeted against ADRP. Subsequent effects on TAG metabolism and PPARalpha activity and target gene expression were determined. Overexpressing ADRP attenuated TAG hydrolysis, whereas siRNA-mediated knockdown of ADRP or ATGL overexpression resulted in enhanced TAG hydrolysis. Results from PPARalpha reporter activity assays demonstrated that decreasing TAG hydrolysis by ADRP overexpression resulted in a 35-60% reduction in reporter activity under basal conditions or in the presence of fatty acids. As expected, PPARalpha target genes were also decreased in response to ADRP overexpression. However, the PPARalpha ligand, WY-14643, was able to restore PPARalpha activity following ADRP overexpression. Despite its effects on PPARalpha, overexpressing ADRP did not affect PPARgamma activity. Enhancing TAG hydrolysis through ADRP knockdown or ATGL overexpression increased PPARalpha activity. These results indicate that TAG hydrolysis and the consequential release of fatty acids regulate PPARalpha activity.

  17. Activation and Exhaustion of Adaptive Immune Cells in Hepatitis B Infection.

    PubMed

    Gogoi, Dimpu; Borkakoty, Biswajyoti; Biswas, Dipankar; Mahanta, Jagadish

    2015-09-01

    In hepatitis B virus (HBV) infection, the immune reaction is responsible for viral clearance and preventing their spread within the host. However, the immune system is dysfunctional in patients with chronic HBV infection, leading to an inadequate immune response against the virus. A major factor contributing to inefficient immune function is the phenomenon of immune exhaustion. Hence, understanding immune activation and exhaustion during HBV infection is important, as it would provide insight in developing immunotherapy to control chronic HBV infection. The aim of this review is to highlight the existing information on immune effector functions and immune exhaustion in response to HBV infection.

  18. Activated hepatic stellate cells play pivotal roles in hepatocellular carcinoma cell chemoresistance and migration in multicellular tumor spheroids

    PubMed Central

    Song, Yeonhwa; Kim, Se-hyuk; Kim, Kang Mo; Choi, Eun Kyung; Kim, Joon; Seo, Haeng Ran

    2016-01-01

    Most Hepatocellular carcinoma (HCC) are resistant to conventional chemotherapeutic agents and remain an unmet medical need. Recently, multiple studies on the crosstalk between HCC and their tumor microenvironment have been conducted to overcome chemoresistance in HCC. In this study, we formed multicellular tumor spheroids (MCTS) to elucidate the mechanisms of environment-mediated chemoresistance in HCC. We observed that hepatic stellate cells (HSCs) in MCTS significantly increased the compactness of spheroids and exhibited strong resistance to sorafenib and cisplatin relative to other types of stromal cells. Increased collagen 1A1 (COL1A1) expression was apparent in activated HSCs but not in fibroblasts or vascular endothelial cells in MCTS. Additionally, COL1A1 deficiency, which was increased by co-culture with HSCs, decreased the cell-cell interactions and thereby increased the therapeutic efficacy of anticancer therapies in MCTS. Furthermore, losartan, which can inhibit collagen I synthesis, attenuated the compactness of spheroids and increased the therapeutic efficacy of anticancer therapies in MCTS. Meanwhile, activated HSCs facilitated HCC migration by upregulating matrix metallopeptidase 9 (MMP9) in MCTS. Collectively, crosstalk between HCC cells and HSCs promoted HCC chemoresistance and migration by increasing the expression of COL1A1 and MMP9 in MCTS. Hence, targeting HSCs might represent a promising therapeutic strategy for liver cancer therapy. PMID:27853186

  19. Sulfatide-Mediated Activation of Type II Natural Killer T Cells Prevents Hepatic Ischemic Reperfusion Injury In Mice

    PubMed Central

    Arrenberg, Philomena; Maricic, Igor; Kumar, Vipin

    2011-01-01

    Background & Aims Hepatic ischemic reperfusion injury (IRI) is a major complication of liver transplantation and resectional hepatic surgeries. Natural killer T (NKT) cells predominate in liver, where they recognize lipid antigens bound to CD1d molecules. Type I NKT cells utilize a semi-invariant T-cell receptor and react with α-galactosylceramide; type II NKT cells use diverse T-cell receptors. Some type II NKT cells recognize the self-glycolipid sulfatide. It is not clear whether or how these distinct NKT cell subsets mediate hepatocellular damage following IRI. Methods We examined the roles of type I and type II NKT cells in mice with partial hepatic, warm ischemia and reperfusion injury. Results Mice that lack type I NKT cells (Jα18−/−) were protected from hepatic IRI, indicated by reduced hepatocellular necrosis and serum levels of alanine aminotransferase. Sulfatide-mediated activation of type II NKT cells reduced IFN-γ secretion by type I NKT cells and prevented IRI. Protection from hepatic IRI by sulfatide-mediated inactivation of type I NKT cells was associated with significant reductions in hepatic recruitment of myeloid cell subsets, especially the CD11b+Gr-1int, Gr-1−, and NK cells. Conclusion In mice, subsets of NKT cells have opposing roles in hepatic IRI: type I NKT cells promote injury whereas sulfatide-reactive type II NKT cells protect against injury. CD1d activation of NKT cells is conserved from mice to humans, so strategies to modify these processes might be developed to treat patients with hepatic reperfusion injury. PMID:20950612

  20. Hepatic Fasting-Induced PPARα Activity Does Not Depend on Essential Fatty Acids.

    PubMed

    Polizzi, Arnaud; Fouché, Edwin; Ducheix, Simon; Lasserre, Frédéric; Marmugi, Alice P; Mselli-Lakhal, Laila; Loiseau, Nicolas; Wahli, Walter; Guillou, Hervé; Montagner, Alexandra

    2016-09-24

    The liver plays a central role in the regulation of fatty acid metabolism, which is highly sensitive to transcriptional responses to nutrients and hormones. Transcription factors involved in this process include nuclear hormone receptors. One such receptor, PPARα, which is highly expressed in the liver and activated by a variety of fatty acids, is a critical regulator of hepatic fatty acid catabolism during fasting. The present study compared the influence of dietary fatty acids and fasting on hepatic PPARα-dependent responses. Pparα(-/-) male mice and their wild-type controls were fed diets containing different fatty acids for 10 weeks prior to being subjected to fasting or normal feeding. In line with the role of PPARα in sensing dietary fatty acids, changes in chronic dietary fat consumption influenced liver damage during fasting. The changes were particularly marked in mice fed diets lacking essential fatty acids. However, fasting, rather than specific dietary fatty acids, induced acute PPARα activity in the liver. Taken together, the data imply that the potent signalling involved in triggering PPARα activity during fasting does not rely on essential fatty acid-derived ligand.

  1. Controlled trial of a thymic hormone extract (Thymostimulin) in 'autoimmune' chronic active hepatitis.

    PubMed Central

    Hegarty, J E; Nouri Aria, K T; Eddleston, A L; Williams, R

    1984-01-01

    A randomised controlled trial of thymic hormone extracts (Thymostimulin) (1 mg/kg/day for seven days; 1 mg/kg/weekly thereafter) was undertaken in 30 patients (21 women, nine men) with treated, apparently inactive 'autoimmune' chronic active hepatitis during withdrawal of maintenance corticosteroid and azathioprine therapy. Reactivation of disease occurred in 26 patients (86%) during or after treatment withdrawal and was as frequent in the Thymostimulin treated (11 of 13; 84%) and untreated (15 of 17; 88%; p greater than 0.05) groups. Reactivation of disease was accompanied by a severe defect in concanavalin A induced suppressor cell activity, the magnitude of which was similar in the Thymostimulin treated and untreated groups (mean % suppression = 16.4 and 3.2 respectively; p greater than 0.05 vs 84.4 in control subjects). Further studies assessing the optimal dose, duration of treatment, and mode of administration are required to establish a therapeutic role for thymic hormone extracts in 'autoimmune' chronic active hepatitis. PMID:6230296

  2. Tlr4-mutant mice are resistant to acute alcohol-induced sterol-regulatory element binding protein activation and hepatic lipid accumulation.

    PubMed

    Zhang, Zhi-Hui; Liu, Xiao-Qian; Zhang, Cheng; He, Wei; Wang, Hua; Chen, Yuan-Hua; Liu, Xiao-Jing; Chen, Xi; Xu, De-Xiang

    2016-09-15

    Previous studies demonstrated that acute alcohol intoxication caused hepatic lipid accumulation. The present study showed that acute alcohol intoxication caused hepatic lipid accumulation in Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic sterol-regulatory element binding protein (SREBP)-1, a transcription factor regulating fatty acid and triglyceride (TG) synthesis, was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic Fas, Acc, Scd-1 and Dgat-2, the key genes for fatty acid and TG synthesis, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Additional experiment showed that hepatic MyD88 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic NF-κB was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Moreover, hepatic GSH content was reduced and hepatic MDA level was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic CYP2E1 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic p67phox and gp91phox, two NADPH oxidase subunits, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Alpha-phenyl-N-t-butylnitrone (PBN), a free radical spin-trapping agent, protected against alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. In conclusion, Tlr4-mutant mice are resistant to acute alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation.

  3. Tlr4-mutant mice are resistant to acute alcohol-induced sterol-regulatory element binding protein activation and hepatic lipid accumulation

    PubMed Central

    Zhang, Zhi-Hui; Liu, Xiao-Qian; Zhang, Cheng; He, Wei; Wang, Hua; Chen, Yuan-Hua; Liu, Xiao-Jing; Chen, Xi; Xu, De-Xiang

    2016-01-01

    Previous studies demonstrated that acute alcohol intoxication caused hepatic lipid accumulation. The present study showed that acute alcohol intoxication caused hepatic lipid accumulation in Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic sterol-regulatory element binding protein (SREBP)-1, a transcription factor regulating fatty acid and triglyceride (TG) synthesis, was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic Fas, Acc, Scd-1 and Dgat-2, the key genes for fatty acid and TG synthesis, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Additional experiment showed that hepatic MyD88 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic NF-κB was activated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Moreover, hepatic GSH content was reduced and hepatic MDA level was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic CYP2E1 was elevated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Hepatic p67phox and gp91phox, two NADPH oxidase subunits, were up-regulated in alcohol-treated Tlr4-wild-type mice but not in Tlr4-mutant mice. Alpha-phenyl-N-t-butylnitrone (PBN), a free radical spin-trapping agent, protected against alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. In conclusion, Tlr4-mutant mice are resistant to acute alcohol-induced hepatic SREBP-1 activation and hepatic lipid accumulation. PMID:27627966

  4. Microbial translocation is associated with increased monocyte activation and dementia in AIDS patients.

    PubMed

    Ancuta, Petronela; Kamat, Anupa; Kunstman, Kevin J; Kim, Eun-Young; Autissier, Patrick; Wurcel, Alysse; Zaman, Tauheed; Stone, David; Mefford, Megan; Morgello, Susan; Singer, Elyse J; Wolinsky, Steven M; Gabuzda, Dana

    2008-06-25

    Elevated plasma lipopolysaccharide (LPS), an indicator of microbial translocation from the gut, is a likely cause of systemic immune activation in chronic HIV infection. LPS induces monocyte activation and trafficking into brain, which are key mechanisms in the pathogenesis of HIV-associated dementia (HAD). To determine whether high LPS levels are associated with increased monocyte activation and HAD, we obtained peripheral blood samples from AIDS patients and examined plasma LPS by Limulus amebocyte lysate (LAL) assay, peripheral blood monocytes by FACS, and soluble markers of monocyte activation by ELISA. Purified monocytes were isolated by FACS sorting, and HIV DNA and RNA levels were quantified by real time PCR. Circulating monocytes expressed high levels of the activation markers CD69 and HLA-DR, and harbored low levels of HIV compared to CD4(+) T-cells. High plasma LPS levels were associated with increased plasma sCD14 and LPS-binding protein (LBP) levels, and low endotoxin core antibody levels. LPS levels were higher in HAD patients compared to control groups, and were associated with HAD independently of plasma viral load and CD4 counts. LPS levels were higher in AIDS patients using intravenous heroin and/or ethanol, or with Hepatitis C virus (HCV) co-infection, compared to control groups. These results suggest a role for elevated LPS levels in driving monocyte activation in AIDS, thereby contributing to the pathogenesis of HAD, and provide evidence that cofactors linked to substance abuse and HCV co-infection influence these processes.

  5. Niemann-Pick Type C2 Protein Mediates Hepatic Stellate Cells Activation by Regulating Free Cholesterol Accumulation.

    PubMed

    Twu, Yuh-Ching; Lee, Tzong-Shyuan; Lin, Yun-Lian; Hsu, Shih-Ming; Wang, Yuan-Hsi; Liao, Chia-Yu; Wang, Chung-Kwe; Liang, Yu-Chih; Liao, Yi-Jen

    2016-07-13

    In chronic liver diseases, regardless of their etiology, the development of fibrosis is the first step toward the progression to cirrhosis, portal hypertension, and hepatocellular carcinoma. Hepatic stellate cells (HSCs) are the main profibrogenic cells that promote the pathogenesis of liver fibrosis, and so it is important to identify the molecules that regulate HSCs activation and liver fibrosis. Niemann-Pick type C2 (NPC2) protein plays an important role in the regulation of intracellular cholesterol homeostasis by directly binding with free cholesterol. However, the roles of NPC2 in HSCs activation and liver fibrosis have not been explored in detail. Since a high-cholesterol diet exacerbates liver fibrosis progression in both rodents and humans, we propose that the expression of NPC2 affects free cholesterol metabolism and regulates HSCs activation. In this study, we found that NPC2 is decreased in both thioacetamide- and carbon tetrachloride-induced liver fibrosis tissues. In addition, NPC2 is expressed in quiescent HSCs, but its activation status is down-regulated. Knockdown of NPC2 in HSC-T6 cells resulted in marked increases in transforming growth factor-β1 (TGF-β1)-induced collagen type 1 α1 (Col1a1), α-smooth muscle actin (α-SMA) expression, and Smad2 phosphorylation. In contrast, NPC2 overexpression decreased TGF-β1-induced HSCs activation. We further demonstrated that NPC2 deficiency significantly increased the accumulation of free cholesterol in HSCs, increasing Col1a1 and α-SMA expression and activating Smad2, and leading to sensitization of HSCs to TGF-β1 activation. In contrast, overexpression of NPC2 decreased U18666A-induced free cholesterol accumulation and inhibited the subsequent HSCs activation. In conclusion, our study has demonstrated that NPC2 plays an important role in HSCs activation by regulating the accumulation of free cholesterol. NPC2 overexpression may thus represent a new treatment strategy for liver fibrosis.

  6. Niemann-Pick Type C2 Protein Mediates Hepatic Stellate Cells Activation by Regulating Free Cholesterol Accumulation

    PubMed Central

    Twu, Yuh-Ching; Lee, Tzong-Shyuan; Lin, Yun-Lian; Hsu, Shih-Ming; Wang, Yuan-Hsi; Liao, Chia-Yu; Wang, Chung-Kwe; Liang, Yu-Chih; Liao, Yi-Jen

    2016-01-01

    In chronic liver diseases, regardless of their etiology, the development of fibrosis is the first step toward the progression to cirrhosis, portal hypertension, and hepatocellular carcinoma. Hepatic stellate cells (HSCs) are the main profibrogenic cells that promote the pathogenesis of liver fibrosis, and so it is important to identify the molecules that regulate HSCs activation and liver fibrosis. Niemann-Pick type C2 (NPC2) protein plays an important role in the regulation of intracellular cholesterol homeostasis by directly binding with free cholesterol. However, the roles of NPC2 in HSCs activation and liver fibrosis have not been explored in detail. Since a high-cholesterol diet exacerbates liver fibrosis progression in both rodents and humans, we propose that the expression of NPC2 affects free cholesterol metabolism and regulates HSCs activation. In this study, we found that NPC2 is decreased in both thioacetamide- and carbon tetrachloride-induced liver fibrosis tissues. In addition, NPC2 is expressed in quiescent HSCs, but its activation status is down-regulated. Knockdown of NPC2 in HSC-T6 cells resulted in marked increases in transforming growth factor-β1 (TGF-β1)-induced collagen type 1 α1 (Col1a1), α-smooth muscle actin (α-SMA) expression, and Smad2 phosphorylation. In contrast, NPC2 overexpression decreased TGF-β1-induced HSCs activation. We further demonstrated that NPC2 deficiency significantly increased the accumulation of free cholesterol in HSCs, increasing Col1a1 and α-SMA expression and activating Smad2, and leading to sensitization of HSCs to TGF-β1 activation. In contrast, overexpression of NPC2 decreased U18666A-induced free cholesterol accumulation and inhibited the subsequent HSCs activation. In conclusion, our study has demonstrated that NPC2 plays an important role in HSCs activation by regulating the accumulation of free cholesterol. NPC2 overexpression may thus represent a new treatment strategy for liver fibrosis. PMID:27420058

  7. O-GlcNAcylation Increases ChREBP Protein Content and Transcriptional Activity in the Liver

    PubMed Central

    Guinez, Céline; Filhoulaud, Gaëlle; Rayah-Benhamed, Fadila; Marmier, Solenne; Dubuquoy, Céline; Dentin, Renaud; Moldes, Marthe; Burnol, Anne-Françoise; Yang, Xiaoyong; Lefebvre, Tony; Girard, Jean; Postic, Catherine

    2011-01-01

    OBJECTIVE Carbohydrate-responsive element–binding protein (ChREBP) is a key transcription factor that mediates the effects of glucose on glycolytic and lipogenic genes in the liver. We have previously reported that liver-specific inhibition of ChREBP prevents hepatic steatosis in ob/ob mice by specifically decreasing lipogenic rates in vivo. To better understand the regulation of ChREBP activity in the liver, we investigated the implication of O-linked β-N-acetylglucosamine (O-GlcNAc or O-GlcNAcylation), an important glucose-dependent posttranslational modification playing multiple roles in transcription, protein stabilization, nuclear localization, and signal transduction. RESEARCH DESIGN AND METHODS O-GlcNAcylation is highly dynamic through the action of two enzymes: the O-GlcNAc transferase (OGT), which transfers the monosaccharide to serine/threonine residues on a target protein, and the O-GlcNAcase (OGA), which hydrolyses the sugar. To modulate ChREBPOG in vitro and in vivo, the OGT and OGA enzymes were overexpressed or inhibited via adenoviral approaches in mouse hepatocytes and in the liver of C57BL/6J or obese db/db mice. RESULTS Our study shows that ChREBP interacts with OGT and is subjected to O-GlcNAcylation in liver cells. O-GlcNAcylation stabilizes the ChREBP protein and increases its transcriptional activity toward its target glycolytic (L-PK) and lipogenic genes (ACC, FAS, and SCD1) when combined with an active glucose flux in vivo. Indeed, OGT overexpression significantly increased ChREBPOG in liver nuclear extracts from fed C57BL/6J mice, leading in turn to enhanced lipogenic gene expression and to excessive hepatic triglyceride deposition. In the livers of hyperglycemic obese db/db mice, ChREBPOG levels were elevated compared with controls. Interestingly, reducing ChREBPOG levels via OGA overexpression decreased lipogenic protein content (ACC, FAS), prevented hepatic steatosis, and improved the lipidic profile of OGA-treated db/db mice

  8. meso-Dihydroguaiaretic acid inhibits hepatic lipid accumulation by activating AMP-activated protein kinase in human HepG2 cells.

    PubMed

    Lee, Myoung-Su; Kim, Kyung Jin; Kim, Daeyoung; Lee, Kyung-Eun; Hwang, Jae-Kwan

    2011-01-01

    Hepatic lipid accumulation is a major risk factor for dyslipidemia, nonalcoholic fatty liver disease, and insulin resistance. The present study was conducted to evaluate hypolipidemic effects of meso-dihydroguaiaretic acid (MDA), anti-oxidative and anti-inflammatory compound isolated from the Myristica fragrans HOUTT., by oil red O staining, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot. MDA significantly inhibited insulin-induced hepatic lipid accumulation in a dose-dependent manner. The lipid-lowering effect of MDA was accompanied by increased expression of proteins involved in fatty acid oxidation and decreased expression of lipid synthetic proteins. In addition, MDA activated AMP-activated protein kinase (AMPK) as determined by phosphorylation of acetyl-CoA carboxylase (ACC), a downstream target of AMPK. The effects of MDA on lipogenic protein expression were suppressed by pretreatment with compound C, an AMPK inhibitor. Taken together, these findings show that MDA inhibits insulin-induced lipid accumulation in human HepG2 cells by suppressing expression of lipogenic proteins through AMPK signaling, suggesting a potent lipid-lowering agent.

  9. NS5ATP13 Promotes Liver Fibrogenesis via Activation of Hepatic Stellate Cells.

    PubMed

    Li, Yaru; Liu, Shunai; Han, Ming; Lu, Hongping; Wang, Qi; Zhang, Yu; Tursun, Kelbinur; Li, Zhongshu; Feng, Shenghu; Cheng, Jun

    2017-01-29

    Liver fibrosis is a reversible wound-healing response to any etiology of chronic hepatic injuries. Activation of hepatic stellate cells (HSCs) is the key event in liver fibrogenesis. Generally, persistent activation and proliferation of HSCs results in liver fibrosis progression, while primary mechanisms of liver fibrosis resolution are apoptosis and reversion to a quiescent phenotype of activated HSCs. NS5ATP13 (HCV NS5A-transactivated protein 13) is involved in nucleologenesis and tumorigenesis, but its role in liver fibrosis and HSC activation remains unclear. This study found that NS5ATP13 was upregulated in both fibrotic liver tissues and activated human HSCs induced by TGF-β1. Moreover, NS5ATP13 enhanced extracellular matrix (ECM) production and HSC activation, with or without TGF-β1 treatment, likely involving the TGF-β1/Smad3 signaling pathway. Additionally, NS5ATP13 boosted HSC proliferation by inhibiting cell apoptosis. Furthermore, HCV NS5A promoted the profibrogenic effect of NS5ATP13 partly through TGF-β1 and NF-κB p65 (RelA) upregulation. Meanwhile, NS5ATP13 was required for the pro-fibrogenic effect of NF-κB. Moreover, NS5ATP13 and NF-κB phosphorylation as well as HSC activation were reduced by CX-4945, a CK2 specific inhibitor. These findings indicated that NS5ATP13 acts as a profibrogenic factor, providing a potential target for antifibrotic therapies. This article is protected by copyright. All rights reserved.

  10. Infection does not increase long-term mortality in patients with acute severe alcoholic hepatitis treated with corticosteroids

    PubMed Central

    Dhanda, Ashwin D; Sinha, Ashish; Hunt, Vicky; Saleem, Sarah; Cramp, Matthew E; Collins, Peter L

    2017-01-01

    AIM To determine whether infection in patients with acute severe alcoholic hepatitis (AAH) treated with corticosteroids is associated with increased mortality. METHODS Consecutive patients with AAH were treated with steroids and recruited to the study. Clinically relevant infections (body temperature > 38 °C or < 36 °C for more than 4 h, ascitic neutrophil count > 0.25 ×109/L, consolidation on chest radiograph or clinically relevant positive microbiological culture of bodily fluid) were recorded prospectively. Clinical and laboratory parameters were recorded and survival at 90 d and 6 mo was determined. Univariate analysis of factors associated with 90-d mortality was performed and significant variables included in a multivariate analysis. RESULTS Seventy-two patients were included in the final analysis (mean age 47.9 years, 26% female, mean discriminant function 53.0). Overall mortality in the group occurred in 15 (21%), 23 (32%) and 31 (43%) at day 28, day 90 and 1 year respectively. 36 (50%) had a clinically relevant infection during their hospitalisation (23 after initiation of steroids). The median time to development of incident infection after commencement of steroids was 10 d. The commonest site of infection was ascites (31%) and bacteraemia (31%) followed by urinary tract (19%) and respiratory tract (8%). Forty-one separate organisms were isolated in 33 patients; the most frequent genus was Escherichia (22%) and Enterococcus (20%). Infection was not associated with 90-d or 1 year mortality but was associated with higher creatinine, model for end-stage liver disease and Lille score. Baseline urea was the only independent predictor of 90-d mortality. CONCLUSION Clinically relevant infections are common in patients with AAH but are not associated with increased 90-d or 1 year mortality. PMID:28373772

  11. Nrf2 pathway activation contributes to anti-fibrosis effects of ginsenoside Rg1 in a rat model of alcohol- and CCl4-induced hepatic fibrosis

    PubMed Central

    Li, Jian-ping; Gao, Yan; Chu, Shi-feng; Zhang, Zhao; Xia, Cong-yuan; Mou, Zheng; Song, Xiu-yun; He, Wen-bin; Guo, Xiao-feng; Chen, Nai-hong

    2014-01-01

    Aim: To investigate the anti-fibrosis effects of ginsenoside Rg1 on alcohol- and CCl4-induced hepatic fibrosis in rats and to explore the mechanisms of the effects. Methods: Rats were given 6% alcohol in water and injected with CCl4 (2 mL/kg, sc) twice a week for 8 weeks. Rg1 (10, 20 and 40 mg/kg per day, po) was administered in the last 2 weeks. Hepatic fibrosis was determined by measuring serum biochemical parameters, HE staining, Masson's trichromic staining, and hydroxyproline and α-SMA immunohistochemical staining of liver tissues. The activities of antioxidant enzymes, lipid peroxidation, and Nrf2 signaling pathway-related proteins (Nrf2, Ho-1 and Nqo1) in liver tissues were analyzed. Cultured hepatic stellate cells (HSCs) of rats were prepared for in vitro studies. Results: In the alcohol- and CCl4-treated rats, Rg1 administration dose-dependently suppressed the marked increases of serum ALT, AST, LDH and ALP levels, inhibited liver inflammation and HSC activation and reduced liver fibrosis scores. Rg1 significantly increased the activities of antioxidant enzymes (SOD, GSH-Px and CAT) and reduced MDA levels in liver tissues. Furthermore, Rg1 significantly increased the expression and nuclear translocation of Nrf2 that regulated the expression of many antioxidant enzymes. Treatment of the cultured HSCs with Rg1 (1 μmol/L) induced Nrf2 translocation, and suppressed CCl4-induced cell proliferation, reversed CCl4- induced changes in MDA, GPX, PCIII and HA contents in the supernatant fluid and α-SMA expression in the cells. Knockdown of Nrf2 gene diminished these actions of Rg1 in CCl4-treated HSCs in vitro. Conclusion: Rg1 exerts protective effects in a rat model of alcohol- and CCl4-induced hepatic fibrosis via promoting the nuclear translocation of Nrf2 and expression of antioxidant enzymes. PMID:24976156

  12. Technology to promote and increase physical activity in heart failure.

    PubMed

    Franklin, Nina C

    2015-01-01

    Regular physical activity is firmly recommended as part of a multifaceted approach to heart failure (HF) self-management. Unfortunately, research indicates that most patients are less likely to engage in and adhere to such activities. The widespread use of information and communication technology tools and resources offers an innovative and potentially beneficial avenue for increasing physical activity levels in HF patients. This article presents specific ways in which advances in information and communication technologies, including Internet- and mobile-based communications, social media platforms, and self-monitoring health devices, can serve as a means to broadly promote increasing levels of physical activity to improve health outcomes in the HF population.

  13. High-fat diet from perilla oil induces insulin resistance despite lower serum lipids and increases hepatic fatty acid oxidation in rats

    PubMed Central

    2014-01-01

    Background The purpose of this study is to investigate the effects of a high-fat diet from perilla oil on serum lipids, hepatic lipid metabolism and insulin sensitivity. Methods Male Sprague–Dawley (SD) rats were fed either a control (CT) diet or a diet high in perilla oil (HP). After 16 weeks of feeding, the serum lipids were measured, and the gene expressions involved in hepatic fatty acid oxidation and synthesis were determined. In addition, hepatic fat deposition was detected, and insulin sensitivity was evaluated by means of euglycemic-hyperinsulinemic clamp. Results Compared with the rats in the CT group, the HP-feeding significantly decreased the levels of triglyceride (TG), total cholesterol (TCH) and HDL-cholesterol (HDL-c). HP-feeding did not change the levels of LDL-cholesterol (LDL-c), free fatty acid (FFA), intrahepatic lipids or body weight. Moreover, the HP-feeding dramatically increased the mRNA expressions of fatty acid oxidation markers (PPAR-alpha, CPT1A) and fatty acid synthesis markers (SREBP-1, FASN and ACC) in the liver. The HP-feeding induced increased protein levels of CPT1A, while reducing the protein levels of FASN and ACC in the liver. However, the glucose infusion rate significantly increased in the HP group compared with the CT group. Conclusions Our data show that, in rats, excessive perilla oil intake may significantly lower serum lipids, strengthen hepatic fatty acid oxidation, and inhibit hepatic fatty acid synthesis, but at the same time may also lead to insulin resistance. PMID:24422660

  14. Asbestos exposure increases human bronchial epithelial cell fibrinolytic activity.

    PubMed

    Gross, T J; Cobb, S M; Gruenert, D C; Peterson, M W

    1993-03-01

    Chronic exposure to asbestos fibers results in fibrotic lung disease. The distal pulmonary epithelium is an early target of asbestos-mediated injury. Local plasmin activity may be important in modulating endoluminal inflammatory responses in the lung. We studied the effects of asbestos exposure on cell-mediated plasma clot lysis as a marker of pericellular plasminogen activation. Exposing human bronchial epithelial (HBE) cells to 100 micrograms/ml of asbestos fibers for 24 h resulted in increased plasma clot lysis. Fibrinolytic activity was augmented in a dose-dependent fashion, was not due to secreted protease, and occurred only when there was direct contact between the plasma clot and the epithelial monolayer. Further analysis showed that asbestos exposure increased HBE cell-associated urokinase-type plasminogen activator (uPA) activity in a time-dependent manner. The increased cell-associated PA activity could be removed by acid washing. The increase in PA activity following asbestos exposure required new protein synthesis because it was abrogated by treatment with either cycloheximide or actinomycin D. Therefore, asbestos exposure increases epithelial-mediated fibrinolysis by augmenting expression of uPA activity at the cell surface by mechanisms that require new RNA and protein synthesis. These observations suggest a novel mechanism whereby exposure of the distal epithelium to inhaled particulates may result in a chronic inflammatory response that culminates in the development of fibrotic lung disease.

  15. Alteration of N-glycoproteins/N-glycosites in human hepatic stellate cells activated with transforming growth factor-β1.

    PubMed

    Qin, Y; Wang, Q; Zhong, Y; Zhao, F; Wu, F; Wang, Y; Ma, T; Liu, C; Bian, H; Li, Z

    2016-03-20

    Proteins N-glycosylation is significantly increased in the activated human hepatic stellate cells (HSCs) stimulated by transforming growth factor-β1 (TGF-β1) compared to the quiescent HSCs according to our previous study. However, little is known about the alteration of N-glycoprotein profiles in the activated HSCs. Profiles of N-glycopeptides / N-glycoproteins / N-glycosites in LX-2 cells, with and without activation by TGF-β1, were identified and compared using hydrazide chemistry enrichment coupled with liquid chromatography - mass spectrometry analysis. Western blot and immunohistochemistry were further used for validation. A total of 103 non-redundant N-glycopeptides, with 107 glycosylation sites from 86 N-glycoproteins, were identified in activated and quiescent LX-2 cells respectively. Among these, 23 proteins were known N-glycoproteins, and 58 were newly identified N-glycoproteins. In addition, 43 proteins (e.g., pigment epithelium-derived factor and clathrin heavy chain 1) were solely identified or up-regulated in the activated LX-2 cells, which participated in focal adhesion and glycosaminoglycan degradation pathways and were involved in interaction clusters of cytoskeletal proteins (e.g., myosin light chains and keratins). The increased expression of glucosamine (N-acetyl)-6-sulfatase and phospholipase C beta 2 and the decreased expression of zinc finger and BTB domain-containing protein 1 were validated in the activated compared to the quiescent LX-2 cells. In conclusion, increased expression of N-glycoproteins and N-glycosites play important roles in cellular contractility, signal transduction, and responses to stimuli in the activated HSCs, which might provide useful information for discovering novel molecular mechanism of HSC activation and therapeutic targets in liver fibrosis.

  16. Polar bear hepatic cytochrome P450: Immunochemical quantitation, EROD/PROD activity and organochlorines

    SciTech Connect

    Letcher, R.J.; Norstrom, R.J. |

    1994-12-31

    Polar bears (Ursus maritimus) are an ubiquitous mammal atop the arctic marine food chain and bioaccumulate lipophilic environmental contaminants. Antibodies prepared against purified rat liver cytochrome P450-1 Al, -1 A2, -2Bl and -3Al enzymes have been found to cross-react with structurally-related orthologues present in the hepatic microsomes of wild polar bears, immunochemically determined levels of P450-1 A and -2B proteins in polar bear liver relative to liver of untreated rats suggested enzyme induction, probably as a result of exposure to xenobiotic contaminants. Optical density quantitation of the most immunochemically responsive isozymes P450-I Al, -IA2 and -2Bi to polygonal rabbit anti-rat P450-IA/IA2 sera and -2BI antibodies in hepatic microsomes of 13 adult male polar bars from the Resolute Bay area of the Canadian Arctic is presented. Correlations with EROD and PROD catalytic activities and levels of organochlorines, such as polychlorinated biphenyls (PCBs), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (p,p-DDE) and their methyl sulfone (MeSO2-) metabolites are made to determine if compound-specific enzyme induction linkages exist. Inter-species immunochemical quantitation of isozymic P450 cytochromes can serve as an indicator of exposure to biologically active contaminant.

  17. The influence of hepatic insufficiency due to alcoholic cirrhosis on the erythrocyte transketolase activity (ETKA).

    PubMed

    Graudal, N; Torp-Pedersen, K; Bonde, J; Hanel, H K; Kristensen, M; Milman, N; Thomsen, A C

    1987-04-01

    The erythrocyte transketolase activity (ETKA), the stimulated erythrocyte transketolase activity (ETKAS), and the thiaminepyrophosphate effect (TPPE) were measured in 21 alcoholic patients with cirrhosis and hepatic insufficiency, 13 alcoholic patients without cirrhosis and 21 non-alcoholic persons before and after oral treatment with 100 mg of thiamine daily for 2 weeks in order to investigate the influence of hepatic insufficiency on these variables. A statistically significant rise in ETKA and fall in TPPE were found in all three groups. ETKA, ETKAS and TPPE did not differ from each other in alcoholic patients with and without cirrhosis, but TPPE was significantly higher in these patients than in the non-alcoholic persons. The conclusions are that severe cirrhosis does not affect the erythrocyte transketolase apoenzyme, the ability of the tissues to convert thiamine to thiaminepyrophosphate for use in the erythrocytes or the absorption of thiamine from the gastrointestinal tract. Besides alcoholism seems to dispose to thiamine deficiency to a higher degree than cirrhosis, and the role of the liver as a thiamine store appears to be of minor importance in the development of thiamine deficiency. Finally, ETKA, ETKAS, and TPPE are considered to be usable as thiamine deficiency indicators in patients with cirrhosis as well as in patients without cirrhosis.

  18. Hemin potentiates the anti-hepatitis C virus activity of the antimalarial drug artemisinin

    SciTech Connect

    Paeshuyse, Jan; Coelmont, Lotte; Vliegen, Inge; Hemel, Johan van; Vandenkerckhove, Jan; Peys, Eric; Sas, Benedikt; Clercq, Erik De; Neyts, Johan . E-mail: johan.neyts@rega.kuleuven.be

    2006-09-15

    We report that the antimalarial drug artemisinin inhibits hepatitis C virus (HCV) replicon replication in a dose-dependent manner in two replicon constructs at concentrations that have no effect on the proliferation of the exponentially growing host cells. The 50% effective concentration (EC{sub 5}) for inhibition of HCV subgenomic replicon replication in Huh 5-2 cells (luciferase assay) by artemisinin was 78 {+-} 21 {mu}M. Hemin, an iron donor, was recently reported to inhibit HCV replicon replication [mediated by inhibition of the viral polymerase (C. Fillebeen, A.M. Rivas-Estilla, M. Bisaillon, P. Ponka, M. Muckenthaler, M.W. Hentze, A.E. Koromilas, K. Pantopoulos, Iron inactivates the RNA polymerase NS5B and suppresses subgenomic replication of hepatitis C virus, J. Biol. Chem. 280 (2005) 9049-9057.)] at a concentration that had no adverse effect on the host cells. When combined, artemisinin and hemin resulted, over a broad concentration range, in a pronounced synergistic antiviral activity. Also at a concentration (2 {mu}M) that alone had no effect on HCV replication, hemin still potentiated the anti-HCV activity of artemisinin.

  19. Comparative toxicology of tetrachlorobiphenyls in mink and rats. I. Changes in hepatic enzyme activity and smooth endoplasmic reticulum volume

    SciTech Connect

    Gillette, D.M.; Corey, R.D.; Helferich, W.G.; McFarland, J.M.; Lowenstine, L.J.; Moody, D.E.; Hammock, B.D.; Shull, L.R.

    1987-01-01

    Mink have been shown previously to be extraordinarily sensitive to polychlorinated biphenyls (PCBs) and related classes of halogenated hydrocarbons. This study explored several aspects of the acute response of mink to two purified tetrachlorobiphenyl (TCB) congeners and compared their response with that of the rat, a less sensitive and more thoroughly studied species. Young female pastel mink and young female Sprague-Dawley rats received three daily intraperitoneal injections with equimolar doses of either 2,4,2',4'-TCB or 3,4,3',4'-TCB, and were sacrificed after 7 days. Two control groups were used for each species; one was allowed free access to food and the other was pair-fed to the 3,4,3',4'-TCB treatment group. Rats remained clinically normal, while mink treated with 3,4,3',4'-TCB developed severe anorexia, diarrhea, and melena. Both species had significant increases in hepatic cytochrome P-450 content and the characteristic shift in the spectral maxima from 450 to 448 nm in the 3,4,3',4'-TCB- but not in the 2,4,2',4'-TCB-treated animals. Rats but not mink had increased activities of several hepatic monooxygenases in response to both congeners while microsomal epoxide hydrolase was increased in rats after 2,4,2',4'-TCB and in mink after 3,4,3',4'-TCB. Significant increases in the relative volume of smooth endoplasmic reticulum within hepatocytes of 2,4,2',4'-TCB-treated rats but not mink were confirmed by ultrastructural morphometry. Accumulation of both congeners was greater in adipose tissue than in the liver of either species. In both species, concentrations in adipose tissue were much greater for 2,4,2',4'-TCB than for 3,4,3',4'-TCB. PCB toxicosis in mink, as in other species, appeared to be dependent on isomeric arrangement of chlorine substituents. However, unlike other species, the toxicosis was not associated with biochemical or morphological evidence of hepatic enzyme induction.

  20. Hepatitis A

    MedlinePlus

    Hepatitis A Hepatitis A Hepatitis A is a contagious viral infection that can easily affect children and adults. It is one of the most common types of hepatitis virus. Often when you hear about hepatitis A ...

  1. Increased sternocleidomastoid, but not trapezius, muscle activity in response to increased chewing load.

    PubMed

    Häggman-Henrikson, Birgitta; Nordh, Erik; Eriksson, Per-Olof

    2013-10-01

    Previous findings, during chewing, that boluses of larger size and harder texture result in larger amplitudes of both mandibular and head-neck movements suggest a relationship between increased chewing load and incremental recruitment of jaw and neck muscles. The present report evaluated jaw (masseter and digastric) and neck [sternocleidomastoid (SCM) and trapezius] muscle activity during the chewing of test foods of different sizes and textures by 10 healthy subjects. Muscle activity was recorded by surface electromyography and simultaneous mandibular and head movements were recorded using an optoelectronic technique. Each subject performed continuous jaw-opening/jaw-closing movements whilst chewing small and large boluses of chewing gum and rubber silicone (Optosil). For jaw opening/jaw closing without a bolus, SCM activity was recorded for jaw opening concomitantly with digastric activity. During chewing, SCM activity was recorded for jaw closing concomitantly with masseter activity. Trapezius activity was present in some, but not all, cycles. For the masseter and SCM muscles, higher activity was seen with larger test foods, suggesting increased demand and recruitment of these muscles in response to an increased chewing load. This result reinforces the previous notion of a close functional connection between the jaw and the neck motor systems in jaw actions and has scientific and clinical significance for studying jaw function and dysfunction.

  2. Antioxidant activities of ginsenoside Rg1 against cisplatin-induced hepatic injury through Nrf2 signaling pathway in mice.

    PubMed

    Gao, Yan; Chu, Shifeng; Shao, Qianhang; Zhang, Meijin; Xia, Congyuan; Wang, Yingying; Li, Yueting; Lou, Yuxia; Huang, Huiyong; Chen, Naihong

    2017-01-01

    Oxidative stress is mainly caused by reactive oxygen species (ROS). The damage causes a net stress on normal organs, leading to a gradual loss of vital physiological function. ROS, such as free radicals, represent a class of molecules which are derived from the metabolism of oxygen and exist inherently. However, excessive produced ROS can damage all aerobic organisms. Ginseng is one of the most commonly used alternative herbal medicines, also as a traditional Chinese medicine. The aim of this study is to investigate the antioxidant potential function of ginsenoside Rg1 against cisplatin-caused hepatic damage. Male mice were treated with cisplatin to induce oxidative stress to mimic the side effect of anti-cancer drug cisplatin. Ginsenoside Rg1 effectively prevented against cisplatin-induced hepatotoxicity, alleviating histological lesions. Antioxidant functions of Rg1 were restrained by the activation of p62-Keap1-Nrf2 signaling pathway, simultaneously accompanied with expression of protein products. Accumulative p62 and increased activation of JNK in hepatocytes promoted the activation of Nrf2. For the other, degradation of Nrf2 was guided by tyrosine phosphorylation, ubiquitin, and Keap1. In summary, Rg1 prevents hepatotoxicity mainly by inhibiting the binding of Keap1 and Nrf2, partly by p62 accumulation, and more importantly by increasing the production of antioxidative proteins associated to Nrf2. Pharmacological activation of Nrf2 is an effective way in combating against liver injury.

  3. Long non-coding RNA APTR promotes the activation of hepatic stellate cells and the progression of liver fibrosis

    SciTech Connect

    Yu, Fujun; Zheng, Jianjian; Mao, Yuqing; Dong, Peihong; Li, Guojun; Lu, Zhongqiu; Guo, Chuanyong; Liu, Zhanju; Fan, Xiaoming

    2015-08-07

    In this study, we aimed at assessing a role of Alu-mediated p21 transcriptional regulator (APTR) in hepatofibrogenesis. APTR was upregulated in fibrotic liver samples and activated hepatic stellate cells (HSCs). Knockdown of APTR inhibited the activation of HSCs in vitro and mitigated the accumulation of collagen in vivo. Importantly, APTR silencing could abrogate TGF-β{sub 1}-induced upregulation of α-SMA in HSCs. In addition, inhibition of cell cycle and cell proliferation by APTR knockdown was attenuated by p21 siRNA1 in primary HSCs. Finally, serum APTR levels were increased in patients with liver cirrhosis, indicating a potential biomarker for liver cirrhosis. Collectively, evidence is proposed for a new biological role of APTR in hepatofibrogenesis. - Highlights: • APTR is upregulated in fibrotic liver tissues and activated HSCs. • APTR silencing inhibits HSC activation and the progression of liver fibrosis. • Antifibrotic effect of APTR silencing is achieved by increasing p21.

  4. DNMT1-mediated PTEN hypermethylation confers hepatic stellate cell activation and liver fibrogenesis in rats

    SciTech Connect

    Bian, Er-Bao; Huang, Cheng; Ma, Tao-Tao; Tao, Hui; Zhang, Hui; Cheng, Chang; Lv, Xiong-Wen; Li, Jun

    2012-10-01

    Hepatic stellate cell (HSC) activation is an essential event during liver fibrogenesis. Phosphatase and tension homolog deleted on chromosome 10 (PTEN), a tumor suppressor, is a negative regulator of this process. PTEN promoter hypermethylation is a major epigenetic silencing mechanism in tumors. The present study aimed to investigate whether PTEN promoter methylation was involved in HSC activation and liver fibrosis. Treatment of activated HSCs with the DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-azadC) decreased aberrant hypermethylation of the PTEN gene promoter and prevented the loss of PTEN expression that occurred during HSC activation. Silencing DNA methyltransferase 1 (DNMT1) gene also decreased the PTEN gene promoter methylation and upregulated the PTEN gene expression in activated HSC-T6 cells. In addition, knockdown of DNMT1 inhibited the activation of both ERK and AKT pathways in HSC-T6 cells. These results suggest that DNMT1-mediated PTEN hypermethylation caused the loss of PTEN expression, followed by the activation of the PI3K/AKT and ERK pathways, resulting in HSC activation. Highlights: ► PTEN methylation status and loss of PTEN expression ► DNMT1 mediated PTEN hypermethylation. ► Hypermethylation of PTEN contributes to the activation of ERK and AKT pathways.

  5. Mechanism of pyruvate dehydrogenase activation by increased cardiac work.

    PubMed

    Kobayashi, K; Neely, J R

    1983-06-01

    The effects of increased cardiac work, pyruvate and insulin on the state of pyruvate dehydrogenase (PDH) activation and rate of pyruvate decarboxylation was studied in the isolated perfused rat heart. At low levels of cardiac work, 61% of PDH was present in the active form when glucose was the only substrate provided. The actual rate of pyruvate decarboxylation was only 5% of the available capacity calculated from the percent of active PDH. Under this condition, the rate of pyruvate decarboxylation was restricted by the slow rate of pyruvate production from glycolysis. Increasing cardiac work accelerated glycolysis, but production of pyruvate remained rate limiting for pyruvate oxidation and only 40% of the maximal active PDH capacity was used. Addition of insulin along with glucose reduced the percent of active PDH to 16% of the total at low cardiac work. This effect of insulin was associated with increased mitochondria NADH/NAD and acetyl CoA/CoA ratios. With both glucose and insulin the calculated maximum capacity of active PDH was about the same as measured rates of pyruvate oxidation indicating that pyruvate oxidation was limited by the activation state of PDH. In this case, raising the level of cardiac work increased the active PDH to 85% and although pyruvate oxidation was accelerated, measured flux through PDH was only 73% of the maximal activity of active PDH. With pyruvate as added exogenous substrate, PDH was 82% of active at low cardiac work probably due to pyruvate inhibition of PDH kinase. In this case, the measured rate of pyruvate oxidation was 64% of the capacity of active PDH. However, increased cardiac work still caused further activation of PDH to 96% active. Thus, actual rates of pyruvate oxidation in the intact tissue were determined by (1) the supply of pyruvate in hearts receiving glucose alone, (2) by the percent of active PDH in hearts receiving both glucose and insulin at low work and (3) by end-product inhibition in hearts receiving

  6. Increased mutant frequency and altered mutation spectrum of the lacI transgene in Wilson disease rats with hepatitis.

    PubMed

    Sone, H; Li, Y J; Ishizuka, M; Aoki, Y; Nagao, M

    2000-09-15

    The mutant strain Long-Evans Cinnamon (LEC) rat, which accumulates copper in the liver because of a mutation in the Atp7b gene, encoding a copper-ATPase, is a model of Wilson disease. It spontaneously develops hepatitis, and subsequently hepatocellular carcinoma and cholangiofibrosis. Excess intracellular copper has been thought to induce DNA damage through reactive oxygen species produced by Cu (II)/Cu (I) redox cycling, and also by direct interaction with DNA. We have developed lacI transgenic Wilson disease (WND-B) rats by mating LEC with Big Blue F344 rats carrying a lambda shuttle vector harboring the lacI gene. lacI mutations of the livers of C-B heterozygous (Atp7b w/m, lacI) and WND-B homozygous (Atp7b m/m, lacI) rats at 6, 24, and 40 weeks of ages were analyzed. Mutant frequencies in the WND-B rats were 2.0 +/- 0.7 x 10(-5), 5.3 +/- 0.9 x 10(-5), and 5.3 +/- 1.0 x 10(-5), respectively, significantly higher than those of C-B rats. Nucleotide sequence analysis revealed that the frequency of deletion mutations of more than two nucleotides were much higher, 15% in WND-B rats, but only 2% in C-B rats. In addition, the average size of deletion was larger in the former. Loss of oligonucleotide-repeat units was specific and relatively frequent in WND-B rats. This type of mutation might be implicated in the induction of DNA strand scissions by reactive oxygen species. These findings suggest that the increase in mutant frequencies and/or the specific type of mutation according to copper accumulation play a crucial role in hepatocarcinogenesis in LEC rats.

  7. Chronic hepatitis, hepatocyte fragility, and increased soluble phosphoglycokeratins in transgenic mice expressing a keratin 18 conserved arginine mutant

    PubMed Central

    1995-01-01

    The two major intermediate filament proteins in glandular epithelia are keratin polypeptides 8 and 18 (K8/18). To evaluate the function and potential disease association of K18, we examined the effects of mutating a highly conserved arginine (arg89) of K18. Expression of K18 arg89-->his/cys and its normal K8 partner in cultured cells resulted in punctate staining as compared with the typical filaments obtained after expression of wild-type K8/18. Generation of transgenic mice expressing human K18 arg89-->cys resulted in marked disruption of liver and pancreas keratin filament networks. The most prominent histologic abnormalities were liver inflammation and necrosis that appeared at a young age in association with hepatocyte fragility and serum transaminase elevation. These effects were caused by the mutation since transgenic mice expressing wild-type human K18 showed a normal phenotype. A relative increase in the phosphorylation and glycosylation of detergent solubilized K8/18 was also noted in vitro and in transgenic animals that express mutant K18. Our results indicate that the highly conserved arg plays an important role in glandular keratin organization and tissue fragility as already described for epidermal keratins. Phosphorylation and glycosylation alterations in the arg mutant keratins may account for some of the potential changes in the cellular function of these proteins. Mice expressing mutant K18 provide a novel animal model for human chronic hepatitis, and for studying the tissue specific function(s) of K8/18. PMID:8522591

  8. Sedum mexicanum Britt. Induces Apoptosis of Primary Rat Activated Hepatic Stellate Cells.

    PubMed

    Lee, Shou-Lun; Chin, Ting-Yu; Lai, Ching-Long; Wang, Wen-Han

    2015-01-01

    Background. Liver fibrosis is a significant liver disease in Asian countries. Sedum mexicanum Britt. (SM) has been claimed to have antihepatitis efficacy. In traditional folk medicine, a solution of boiling water-extracted SM (SME) is consumed to prevent and treat hepatitis. However, its efficacy has not yet been verified. The purpose of this study was to investigate the in vitro effect of SME on hepatoprotection. Methods. Hepatic stellate cells (HSCs) and hepatocytes (HCs) were isolated from the livers of the rats by enzymatic digestion and density gradient centrifugation. Results. Treating the HCs and aHSCs with SME caused a dose-dependent decrease in the viability of aHSCs but not that of HCs. In addition, treatment with SME resulted in apoptosis of aHSCs, as determined by DAPI analysis and flow cytometry. SME also increased the amount of cleaved caspase-3, cleaved caspase-9, and cleaved poly ADP-ribose polymerase (PARP) in aHSCs. Furthermore, SME treatment induced a dose-dependent reduction in Bcl-2 expression and increased the expression of Bax in aHSCs. Conclusions. SME did not cause cytotoxicity in HCs, but it induced apoptosis in aHSCs through the mitochondria-dependent caspase-3 pathway. Therefore, SME may possess therapeutic potential for liver fibrosis.

  9. Hepatic hemangioma -review-.

    PubMed

    Bajenaru, N; Balaban, V; Săvulescu, F; Campeanu, I; Patrascu, T

    2015-01-01

    Hepatic hemangiomas are benign tumors of the liver consisting of clusters of blood-filled cavities, lined by endothelial cells, fed by the hepatic artery. The vast majority of HH are asymptomatic, most often being discovered incidentally during imaging investigations for various unrelated pathologies. Typical hemangiomas, the so-called capillary hemangiomas, range from a few mm to 3 cm, do not increase in size over time and therefore are unlikely to generate future symptomatology. Small (mm-3 cm) and medium (3 cm-10 cm) hemangiomas are well-defined lesions, requiring no active treatment beside regular follow-ups. However, the so-called giant liver hemangiomas, of up to 10 cm (most commonly) and even 20+ cm in size (according to occasional reports) can, and usually will develop symptoms and complications that require prompt surgical intervention or other kind of therapy. HH belong to the class of hepatic "incidentalomas", so-called because they are diagnosed incidentally, on imaging studies performed as routine examinations or for other reasons than the evaluation of a possible liver mass. Less than half of HH present with overt clinical symptoms, consisting, most often, of upper abdominal pain (this is usually the case for large lesions, which cause the distension of Glisson's capsule). Hepatic hemangiomas require a careful diagnosis to differentiate from other focal hepatic lesions, co-occurring diagnoses are also possible.

  10. Effect of copper chloride in vitro and in vivo on the hepatic EROD activity in the fish Dicentrarchus labrax

    SciTech Connect

    Stien, X.; Risso, C.; Gnassia-Barelli, M.; Romeo, M.; LaFaurie, M.

    1997-02-01

    The effect of copper chloride was studied on the hepatic microsomal 7-ethoxyresorufin-O-deethylase (EROD) activity of the fish Dicentrarchus labrax intraperitoneally injected with benzo[a]pyrene (BaP). In vitro experiments showed that copper significantly decreased EROD activity, and IC50 was estimated at 50 {micro}g Cu/L. The apparent Michaelis constant (K{sub m}) of cytochrome P4501A was constant, whereas maximum velocity (V{sub max}) decreased as a function of copper added to the incubation medium. (K{sub m}) of nicotinamide adenine dinucleotide phosphate [NADPH]-cytochrome P450 reductase increased as a function of copper concentration, whereas V{sub max} remained constant. Absorption spectra showed that the amount of cytochrome P420s increased as a function of copper concentrations added to the medium at the expense of cytochrome P450s. The injection of copper and BaP to fish decreased EROD activity compared with the injection of BaP alone. An increase of immunoquantified CYP1A content measured by Western blotting was noted in microsomes of fish injected with BaP compared with controls. In the case of fish treated with copper and BaP, the band was less intense and accompanied by another band of lower molecular weight. The destruction of the native P450s spectrophotometrically measured in the presence of copper implied that the catalytic activity would be diminished. This was confirmed by decreased EROD activity after either in vitro additions or in vivo treatment with copper. Moreover, immunodetection experiments suggested that the decrease of the catalytic activity resulted more from cytochrome P450s loss than from direct inhibition of EROD activity by copper.

  11. Long non-coding RNA PVT1 activates hepatic stellate cells through competitively binding microRNA-152

    PubMed Central

    Zheng, Jianjian; Yu, Fujun; Dong, Peihong; Wu, Limei; Zhang, Yuan; Hu, Yanwei; Zheng, Lei

    2016-01-01

    Epithelial-mesenchymal transition (EMT) process is considered as a key event in the activation of hepatic stellate cells (HSCs). Hedgehog (Hh) pathway is known to be required for EMT process. Long non-coding RNAs (lncRNAs) have been reported to be involved in a wide range of biological processes. Plasmacytoma variant translocation 1 (PVT1), a novel lncRNA, is often up-regulated in various human cancers. However, the role of PVT1 in liver fibrosis remains undefined. In this study, PVT1 was increased in fibrotic liver tissues and activated HSCs. Depletion of PVT1 attenuated collagen deposits in vivo. In vitro, PVT1 down-regulation inhibited HSC activation including the reduction of HSC proliferation, α-SMA and type I collagen. Further studies showed that PVT1 knockdown suppressed HSC activation was through inhibiting EMT process and Hh pathway. Patched1 (PTCH1), a negative regulator factor of Hh pathway, was enhanced by PVT1 knockdown. PTCH1 demethylation caused by miR-152 was responsible for the effects of PVT1 knockdown on PTCH1 expression. Notably, miR-152 inhibitor reversed the effects of PVT1 knockdown on HSC activation. Luciferase reporter assays and pull-down assays showed a direct interaction between miR-152 and PVT1. Collectively, we demonstrate that PVT1 epigenetically down-regulates PTCH1 expression via competitively binding miR-152, contributing to EMT process in liver fibrosis. PMID:27588491

  12. Current trends in the treatment of hepatitis C: interventions to avoid adverse effects and increase effectiveness of anti-HCV drugs

    PubMed Central

    Saleem, Ammara; Akhtar, Muhammad Furqan; Mushtaq, Muhammed Fahd; Saleem, Muhammad; Muhammad, Syed Taqi; Akhtar, Bushra; Sharif, Ali; Peerzada, Sohaib

    2016-01-01

    Viral hepatitis, an inflammatory liver disease, is caused by various genotypes of hepatitis C viruses (HCV). Hepatitis C slowly sprouts into fibrosis, which progresses to cirrhosis. Over a prolonged period of time compensated cirrhosis can advance to decompensated cirrhosis culminating in hepatic failure and death. Conventional treatment of HCV involves the administration of interferons. However, association of interferon with the adverse drug reactions led to the development of novel anti-HCV drugs given as monotherapy or in combination with the other drugs. Advances in drug delivery systems (DDS) improved the pharmacokinetic profile and stability of drugs, ameliorated tissue damages on extravasation and increased the targeting of affected sites. Liposomes and lipid based vehicles have been employed with polyethylene glycol (PEG) so as to stabilize the formulations as PEG drug complex. Sofosbuvir, a novel anti-HCV drug, is administered as monotherapy or in combination with daclatasvir, ledipasivir, protease inhibitors, ribavirin and interferon for the treatment of HCV genotypes 1, 2 and 3. These drug combinations are highly effective in eradicating the interferon resistance, recurrent HCV infection in liver transplant, concurrent HIV infection and preventing interferon related adverse effects. Further investigations to improve drug targeting and identification of new drug targets are highly warranted due to the rapid emergence of drug resistance in HCV. PMID:28096788

  13. Current trends in the treatment of hepatitis C: interventions to avoid adverse effects and increase effectiveness of anti-HCV drugs.

    PubMed

    Saleem, Ammara; Akhtar, Muhammad Furqan; Mushtaq, Muhammed Fahd; Saleem, Muhammad; Muhammad, Syed Taqi; Akhtar, Bushra; Sharif, Ali; Peerzada, Sohaib

    2016-01-01

    Viral hepatitis, an inflammatory liver disease, is caused by various genotypes of hepatitis C viruses (HCV). Hepatitis C slowly sprouts into fibrosis, which progresses to cirrhosis. Over a prolonged period of time compensated cirrhosis can advance to decompensated cirrhosis culminating in hepatic failure and death. Conventional treatment of HCV involves the administration of interferons. However, association of interferon with the adverse drug reactions led to the development of novel anti-HCV drugs given as monotherapy or in combination with the other drugs. Advances in drug delivery systems (DDS) improved the pharmacokinetic profile and stability of drugs, ameliorated tissue damages on extravasation and increased the targeting of affected sites. Liposomes and lipid based vehicles have been employed with polyethylene glycol (PEG) so as to stabilize the formulations as PEG drug complex. Sofosbuvir, a novel anti-HCV drug, is administered as monotherapy or in combination with daclatasvir, ledipasivir, protease inhibitors, ribavirin and interferon for the treatment of HCV genotypes 1, 2 and 3. These drug combinations are highly effective in eradicating the interferon resistance, recurrent HCV infection in liver transplant, concurrent HIV infection and preventing interferon related adverse effects. Further investigations to improve drug targeting and identification of new drug targets are highly warranted due to the rapid emergence of drug resistance in HCV.

  14. Endoplasmic reticulum stress in mice increases hepatic expression of genes carrying a premature termination codon via a nutritional status-independent GRP78-dependent mechanism.

    PubMed

    Harada, Nagakatsu; Okuyama, Maiko; Yoshikatsu, Aya; Yamamoto, Hironori; Ishiwata, Saori; Hamada, Chikako; Hirose, Tomoyo; Shono, Masayuki; Kuroda, Masashi; Tsutsumi, Rie; Takeo, Jiro; Taketani, Yutaka; Nakaya, Yutaka; Sakaue, Hiroshi

    2017-04-06

    Nonsense-mediated mRNA decay (NMD) degrades mRNAs carrying a premature termination codon (PTC) in eukaryotes. Cellular stresses, including endoplasmic reticulum (ER) stress, inhibit NMD and up-regulate PTC-containing mRNA (PTC-mRNA) levels in several cell lines. However, whether similar effects exist under in vivo conditions that involve systemic nutritional status is unclear. Here we compared the effects of pharmacological induction of ER stress with those of nutritional interventions on hepatic PTC-mRNA levels in mice. In mouse livers, the ER stress inducer tunicamycin increased PTC-mRNA levels of endogenous marker genes. Tunicamycin decreased body weight and perturbed nutrient metabolism in mice. Food restriction or deprivation mimicked the effect of tunicamycin on weight loss and metabolism, but did not increase PTC-mRNA levels. Hyperphagia-induced obesity also had little effect on hepatic PTC-mRNA levels. Meanwhile, in mouse liver phosphorylation of eIF2α, a factor that regulates NMD, was increased by both tunicamycin and nutritional interventions. Hepatic expression of GRP78, a central chaperone in ER stress responses, was increased by tunicamycin but not by the nutritional interventions. In cultured liver cells (Hepa), exogenous overexpression of a phosphomimetic eIF2α failed to increase PTC-mRNA levels. However, GRP78 overexpression in Hepa cells increased PTC-mRNA and PTC-mRNA-derived protein levels. ER stress promoted localization of GRP78 to mitochondria, and exogenous expression of a GRP78 fusion protein targeted to mitochondria mimicked the effect of wild type GRP78. These results indicate that GRP78, but not nutritional status, is a potent up-regulator of hepatic PTC-mRNA levels during induction of ER stress in vivo. This article is protected by copyright. All rights reserved.

  15. Building a better mousetrap (exergame) to increase youth physical activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While exergames have been demonstrated to induce moderate levels of physical activity (PA) if played as designed, there is conflicting evidence on use of exergaming leading to increased habitual PA. Exergames have increased PA in some home and school studies, but not others. Exergames have been us...

  16. The hypotriglyceridemic effect of biotin supplementation involves increased levels of cGMP and AMPK activation.

    PubMed

    Aguilera-Méndez, Asdrúbal; Fernández-Mejía, Cristina

    2012-01-01

    In addition to its role as a carboxylase cofactor, biotin modifies gene expression and has manifold effects on systemic processes. Several studies have shown that biotin supplementation reduces hypertriglyceridemia. We have previously reported that this effect is related to decreased expression of lipogenic genes. In the present work, we analyzed signaling pathways and posttranscriptional mechanisms involved in the hypotriglyceridemic effects of biotin. Male BALB/cAnN Hsd mice were fed a control or a biotin-supplemented diet (1.76 or 97.7 mg of free biotin/kg diet, respectively for 8 weeks after weaning. The abundance of mature sterol regulatory element-binding protein (SREBP-1c), fatty-acid synthase (FAS), total acetyl-CoA carboxylase-1 (ACC-1) and its phosphorylated form, and AMP-activated protein kinase (AMPK) were evaluated in the liver. We also determined the serum triglyceride concentrations and the hepatic levels of triglycerides and cyclic GMP (cGMP). Compared to the control group, biotin-supplemented mice had lower serum and hepatic triglyceride concentrations. Biotin supplementation increased the levels of cGMP and the phosphorylated forms of AMPK and ACC-1 and decreased the abundance of the mature form of SREBP-1c and FAS. These data provide evidence that the mechanisms by which biotin supplementation reduces lipogenesis involve increased cGMP content and AMPK activation. In turn, these changes lead to augmented ACC-1 phosphorylation and decreased expression of both the mature form of SREBP-1c and FAS. Our results demonstrate for the first time that AMPK is involved in the effects of biotin supplementation and offer new insights into the mechanisms of biotin-mediated hypotriglyceridemic effects.

  17. Enhancement of gene transactivation activity of androgen receptor by hepatitis B virus X protein

    SciTech Connect

    Zheng Yanyan; Chen Wenling; Ma, W.-L. Maverick; Chang Chawnshang; Ou, J.-H. James . E-mail: jamesou@hsc.usc.edu

    2007-07-05

    Hepatitis B virus (HBV) X protein (HBx) is a regulatory protein that is required for efficient replication of HBV in its natural host. In this report, we demonstrate by co-immunoprecipitation experiments that HBx can physically bind to the androgen receptor (AR), which is a nuclear hormone receptor that is expressed in many different tissues including the liver. This observation is further supported by confocal microscopy, which reveals that HBx can alter the subcellular localization of the AR both in the presence and in the absence of dihydrotestosterone (DHT). Further studies indicate that HBx can enhance the gene transactivation activity of AR by enhancing its DNA binding activity in a DHT-dependent manner. However, HBx does not remain associated with AR on the DNA. As AR can regulate the expression of a number of cellular genes, our results raise the possibility that HBV pathogenesis may be mediated in part via the interaction between HBx and AR.

  18. Increased ATG5-ATG12 in hepatitis B virus-associated hepatocellular carcinoma and their role in apoptosis

    PubMed Central

    Kunanopparat, Areerat; Kimkong, Ingorn; Palaga, Tanapat; Tangkijvanich, Pisit; Sirichindakul, Boonchoo; Hirankarn, Nattiya

    2016-01-01

    AIM To investigate autophagy-related genes, particularly ATG12, in apoptosis and cell cycle in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) and non-HBV-HCC cell lines. METHODS The expression of autophagy-related genes in HBV-associated hepatocellular carcinoma and non-HBV-HCC cell lines and human liver tissues was examined by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting. The silencing of target genes was used to examine the function of various genes in apoptosis and cell cycle progression. RESULTS The expression of autophagy related genes ATG5, ATG12, ATG9A and ATG4B expression was analyzed in HepG2.2.15 cells and compared with HepG2 and THLE cells. We found that ATG5 and ATG12 mRNA expression was significantly increased in HepG2.2.15 cells compared to HepG2 cells (P < 0.005). Moreover, ATG5-ATG12 protein levels were increased in tumor liver tissues compared to adjacent non-tumor tissues mainly from HCC patients with HBV infection. We also analyzed the function of ATG12 in cell apoptosis and cell cycle progression. The percentage of apoptotic cells increased by 11.4% in ATG12-silenced HepG2.2.15 cells (P < 0.005) but did not change in ATG12-silenced HepG2 cells under starvation with Earle’s balanced salt solution. However, the combination blockade of Notch signaling and ATG12 decreased the apoptotic rate of HepG2.2.15 cells from 55.6% to 50.4% (P < 0.05). CONCLUSION ATG12 is important for HBV-associated apoptosis and a potential drug target for HBV-HCC. Combination inhibition of ATG12/Notch signaling had no additional effect on HepG2.2.15 apoptosis. PMID:27729742

  19. Irisin inhibits hepatic gluconeogenesis and increases glycogen synthesis via the PI3K/Akt pathway in type 2 diabetic mice and hepatocytes.

    PubMed

    Liu, Tong-Yan; Shi, Chang-Xiang; Gao, Run; Sun, Hai-Jian; Xiong, Xiao-Qing; Ding, Lei; Chen, Qi; Li, Yue-Hua; Wang, Jue-Jin; Kang, Yu-Ming; Zhu, Guo-Qing

    2015-11-01

    Increased glucose production and reduced hepatic glycogen storage contribute to metabolic abnormalities in diabetes. Irisin, a newly identified myokine, induces the browning of white adipose tissue, but its effects on gluconeogenesis and glycogenesis are unknown. In the present study, we investigated the effects and underlying mechanisms of irisin on gluconeogenesis and glycogenesis in hepatocytes with insulin resistance, and its therapeutic role in type 2 diabetic mice. Insulin resistance was induced by glucosamine (GlcN) or palmitate in human hepatocellular carcinoma (HepG2) cells and mouse primary hepatocytes. Type 2 diabetes was induced by streptozotocin/high-fat diet (STZ/HFD) in mice. In HepG2 cells, irisin ameliorated the GlcN-induced increases in glucose production, phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) expression, and glycogen synthase (GS) phosphorylation; it prevented GlcN-induced decreases in glycogen content and the phosphoinositide 3-kinase (PI3K) p110α subunit level, and the phosphorylation of Akt/protein kinase B, forkhead box transcription factor O1 (FOXO1) and glycogen synthase kinase-3 (GSK3). These effects of irisin were abolished by the inhibition of PI3K or Akt. The effects of irisin were confirmed in mouse primary hepatocytes with GlcN-induced insulin resistance and in human HepG2 cells with palmitate-induced insulin resistance. In diabetic mice, persistent subcutaneous perfusion of irisin improved the insulin sensitivity, reduced fasting blood glucose, increased GSK3 and Akt phosphorylation, glycogen content and irisin level, and suppressed GS phosphorylation and PEPCK and G6Pase expression in the liver. Irisin improves glucose homoeostasis by reducing gluconeogenesis via PI3K/Akt/FOXO1-mediated PEPCK and G6Pase down-regulation and increasing glycogenesis via PI3K/Akt/GSK3-mediated GS activation. Irisin may be regarded as a novel therapeutic strategy for insulin resistance and type 2 diabetes.

  20. Exposure to human immunodeficiency virus/hepatitis C virus in hepatic and stellate cell lines reveals cooperative profibrotic transcriptional activation between viruses and cell types.

    PubMed

    Salloum, Shadi; Holmes, Jacinta A; Jindal, Rohit; Bale, Shyam S; Brisac, Cynthia; Alatrakchi, Nadia; Lidofsky, Anna; Kruger, Annie J; Fusco, Dahlene N; Luther, Jay; Schaefer, Esperance A; Lin, Wenyu; Yarmush, Martin L; Chung, Raymond T

    2016-12-01

    Human immunodeficiency virus (HIV)/hepatitis C virus (HCV) coinfection accelerates progressive liver fibrosis; however, the mechanisms remain poorly understood. HCV and HIV independently induce profibrogenic markers transforming growth factor beta-1 (TGFβ1) (mediated by reactive oxygen species [ROS]) and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) in hepatocytes and hepatic stellate cells in monoculture; however, they do not account for cellular crosstalk that naturally occurs. We created an in vitro coculture model and investigated the contributions of HIV and HCV to hepatic fibrogenesis. Green fluorescent protein reporter cell lines driven by functional ROS (antioxidant response elements), NFκB, and mothers against decapentaplegic homolog 3 (SMAD3) promoters were created in Huh7.5.1 and LX2 cells, using a transwell to generate cocultures. Reporter cell lines were exposed to HIV, HCV, or HIV/HCV. Activation of the 3 pathways was measured and compared according to infection status. Extracellular matrix products (collagen type 1 alpha 1 (CoL1A1) and tissue inhibitor of metalloproteinase 1 (TIMP1)) were also measured. Both HCV and HIV independently activated TGFβ1 signaling through ROS (antioxidant response elements), NFκB, and SMAD3 in both cell lines in coculture. Activation of these profibrotic pathways was additive following HIV/HCV coexposure. This was confirmed when examining CoL1A1 and TIMP1, where messenger RNA and protein levels were significantly higher in LX2 cells in coculture following HIV/HCV coexposure compared with either virus alone. In addition, expression of these profibrotic genes was significantly higher in the coculture model compared to either cell type in monoculture, suggesting an interaction and feedback mechanism between Huh7.5.1 and LX2 cells.

  1. Lipotoxicity in steatohepatitis occurs despite an increase in tricarboxylic acid cycle activity

    PubMed Central

    Patterson, Rainey E.; Kalavalapalli, Srilaxmi; Williams, Caroline M.; Nautiyal, Manisha; Mathew, Justin T.; Martinez, Janie; Reinhard, Mary K.; McDougall, Danielle J.; Rocca, James R.; Yost, Richard A.; Cusi, Kenneth; Garrett, Timothy J.

    2016-01-01

    The hepatic tricarboxylic acid (TCA) cycle is central to integrating macronutrient metabolism and is closely coupled to cellular respiration, free radical generation, and inflammation. Oxidative flux through the TCA cycle is induced during hepatic insulin resistance, in mice and humans with simple steatosis, reflecting early compensatory remodeling of mitochondrial energetics. We hypothesized that progressive severity of hepatic insulin resistance and the onset of nonalcoholic steatohepatitis (NASH) would impair oxidative flux through the hepatic TCA cycle. Mice (C57/BL6) were fed a high-trans-fat high-fructose diet (TFD) for 8 wk to induce simple steatosis and NASH by 24 wk. In vivo fasting hepatic mitochondrial fluxes were determined by 13C-nuclear magnetic resonance (NMR)-based isotopomer analysis. Hepatic metabolic intermediates were quantified using mass spectrometry-based targeted metabolomics. Hepatic triglyceride accumulation and insulin resistance preceded alterations in mitochondrial metabolism, since TCA cycle fluxes remained normal during simple steatosis. However, mice with NASH had a twofold induction (P < 0.05) of mitochondrial fluxes (μmol/min) through the TCA cycle (2.6 ± 0.5 vs. 5.4 ± 0.6), anaplerosis (9.1 ± 1.2 vs. 16.9 ± 2.2), and pyruvate cycling (4.9 ± 1.0 vs. 11.1 ± 1.9) compared with their age-matched controls. Induction of the TCA cycle activity during NASH was concurrent with blunted ketogenesis and accumulation of hepatic diacylglycerols (DAGs), ceramides (Cer), and long-chain acylcarnitines, suggesting inefficient oxidation and disposal of excess free fatty acids (FFA). Sustained induction of mitochondrial TCA cycle failed to prevent accretion of “lipotoxic” metabolites in the liver and could hasten inflammation and the metabolic transition to NASH. PMID:26814015

  2. Lipotoxicity in steatohepatitis occurs despite an increase in tricarboxylic acid cycle activity.

    PubMed

    Patterson, Rainey E; Kalavalapalli, Srilaxmi; Williams, Caroline M; Nautiyal, Manisha; Mathew, Justin T; Martinez, Janie; Reinhard, Mary K; McDougall, Danielle J; Rocca, James R; Yost, Richard A; Cusi, Kenneth; Garrett, Timothy J; Sunny, Nishanth E

    2016-04-01

    The hepatic tricarboxylic acid (TCA) cycle is central to integrating macronutrient metabolism and is closely coupled to cellular respiration, free radical generation, and inflammation. Oxidative flux through the TCA cycle is induced during hepatic insulin resistance, in mice and humans with simple steatosis, reflecting early compensatory remodeling of mitochondrial energetics. We hypothesized that progressive severity of hepatic insulin resistance and the onset of nonalcoholic steatohepatitis (NASH) would impair oxidative flux through the hepatic TCA cycle. Mice (C57/BL6) were fed a high-trans-fat high-fructose diet (TFD) for 8 wk to induce simple steatosis and NASH by 24 wk. In vivo fasting hepatic mitochondrial fluxes were determined by(13)C-nuclear magnetic resonance (NMR)-based isotopomer analysis. Hepatic metabolic intermediates were quantified using mass spectrometry-based targeted metabolomics. Hepatic triglyceride accumulation and insulin resistance preceded alterations in mitochondrial metabolism, since TCA cycle fluxes remained normal during simple steatosis. However, mice with NASH had a twofold induction (P< 0.05) of mitochondrial fluxes (μmol/min) through the TCA cycle (2.6 ± 0.5 vs. 5.4 ± 0.6), anaplerosis (9.1 ± 1.2 vs. 16.9 ± 2.2), and pyruvate cycling (4.9 ± 1.0 vs. 11.1 ± 1.9) compared with their age-matched controls. Induction of the TCA cycle activity during NASH was concurrent with blunted ketogenesis and accumulation of hepatic diacylglycerols (DAGs), ceramides (Cer), and long-chain acylcarnitines, suggesting inefficient oxidation and disposal of excess free fatty acids (FFA). Sustained induction of mitochondrial TCA cycle failed to prevent accretion of "lipotoxic" metabolites in the liver and could hasten inflammation and the metabolic transition to NASH.

  3. Identifying minimal hepatic encephalopathy in cirrhotic patients by measuring spontaneous brain activity.

    PubMed

    Chen, Hua-Jun; Zhang, Ling; Jiang, Long-Feng; Chen, Qiu-Feng; Li, Jun; Shi, Hai-Bin

    2016-08-01

    It has been demonstrated that minimal hepatic encephalopathy (MHE) is associated with aberrant regional intrinsic brain activity in cirrhotic patients. However, few studies have investigated whether altered intrinsic brain activity can be used as a biomarker of MHE among cirrhotic patients. In this study, 36 cirrhotic patients (with MHE, n = 16; without MHE [NHE], n = 20) underwent resting-state functional magnetic resonance imaging (fMRI). Spontaneous brain activity was measured by examining the amplitude of low-frequency fluctuations (ALFF) in the fMRI signal. MHE was diagnosed based on the Psychometric Hepatic Encephalopathy Score (PHES). A two-sample t-test was used to determine the regions of interest (ROIs) in which ALFF differed significantly between the two groups; then, ALFF values within ROIs were selected as classification features. A linear discriminative analysis was used to differentiate MHE patients from NHE patients. The leave-one-out cross-validation method was used to estimate the performance of the classifier. The classification analysis was 80.6 % accurate (81.3 % sensitivity and 80.0 % specificity) in terms of distinguishing between the two groups. Six ROIs were identified as the most discriminative features, including the bilateral medial frontal cortex/anterior cingulate cortex, posterior cingulate cortex/precuneus, left precentral and postcentral gyrus, right lingual gyrus, middle frontal gyrus, and inferior/superior parietal lobule. The ALFF values within ROIs were correlated with PHES in cirrhotic patients. Our findings suggest that altered regional brain spontaneous activity is a useful biomarker for MHE detection among cirrhotic patients.

  4. EGR1 regulates hepatic clock gene amplitude by activating Per1 transcription

    PubMed Central

    Tao, Weiwei; Wu, Jing; Zhang, Qian; Lai, Shan-Shan; Jiang, Shan; Jiang, Chen; Xu, Ying; Xue, Bin; Du, Jie; Li, Chao-Jun

    2015-01-01

    The mammalian clock system is composed of a master clock and peripheral clocks. At the molecular level, the rhythm-generating mechanism is controlled by a molecular clock composed of positive and negative feedback loops. However, the underlying mechanisms for molecular clock regulation that affect circadian clock function remain unclear. Here, we show that Egr1 (early growth response 1), an early growth response gene, is expressed in mouse liver in a circadian manner. Consistently, Egr1 is transactivated by the CLOCK/BMAL1 heterodimer through a conserved E-box response element. In hepatocytes, EGR1 regulates the transcription of several core clock genes, including Bmal1, Per1, Per2, Rev-erbα and Rev-erbβ, and the rhythm amplitude of their expression is dependent on EGR1’s transcriptional function. Further mechanistic studies indicated that EGR1 binds to the proximal region of the Per1 promoter to activate its transcription directly. When the peripheral clock is altered by light or feeding behavior transposition in Egr1-deficient mice, the expression phase of hepatic clock genes shifts normally, but the amplitude is also altered. Our data reveal a critical role for EGR1 in the regulation of hepatic clock circuitry, which may contribute to the rhythm stability of peripheral clock oscillators. PMID:26471974

  5. An interesting case of Lucio phenomenon triggered by activation of hepatitis C infection

    PubMed Central

    Mareen, Jacob; Madhukara, Jithendriya

    2016-01-01

    Lucio phenomenon (LP) or erythema necroticans is a rare type of reaction pattern found in untreated patients with diffuse non-nodular leprosy. It is important to distinguish this from vasculonecrotic erythema nodosum because thalidomide with high-dose steroids is the mainstay of treatment for the latter, whereas LP shows no response to thalidomide. We report a case of a 60-year-old man who presented with purpuric patches, hemorrhagic blisters, and ulcers over extremities of 15 days duration. On cutaneous examination, there were multiple stellate purpuric patches, hemorrhagic bullae, and deep necrotic ulcers, mainly over extremities. Slit-skin smear examination from six sites revealed bacteriological index 6+ with globi, and morphological index 5%. Histopathology revealed diffuse infiltration of bacilli in epidermis, dermis, and endothelial cells along with neutrophilic and lymphocytic infiltrate. Fibrinoid necrosis and thrombosis of blood vessels was also noted. The above clinicohistopathological features helped in making the diagnosis of LP. Concomitantly he was found to be infected with hepatitis C virus. Many triggering factors have been described in literature; however, activation of hepatitis C as a trigger for Lucio phenomenon has not been reported. In addition, IgM and IgG anticardiolipin antibodies were found to be positive. The patient was started on high-dose steroids along with multibacillary antileprosy therapy and improved within 2 weeks. PMID:27730040

  6. Increased hepatocellular carcinoma risk in chronic hepatitis B patients with persistently elevated serum total bile acid: a retrospective cohort study

    PubMed Central

    Wang, Haoliang; Shang, Xiaoyun; Wan, Xing; Xiang, Xiaomei; Mao, Qing; Deng, Guohong; Wu, Yuzhang

    2016-01-01

    To investigate the association between long-term changes of serum total bile acid and hepatocellular carcinoma in chronic hepatitis B patients, we did a retrospective cohort study of 2262 chronic hepatitis B patients with regular antiviral treatment using data from the Hepatitis Biobank at Southwest Hospital Program from 2004 to 2014. Patients in the study were classified into 3 groups according to persistence of elevated serum total bile acid during follow-up: none-low, medium, and high persistence of elevated serum total bile acid. The association between persistence of elevated serum total bile acid and hepatocellular carcinoma was estimated using Cox proportional hazard models and Kaplan-Meier analysis including information about patients’ demographic and clinical characteristics. There were 62 hepatocellular carcinoma cases during a total follow-up of 14756.5 person-years in the retrospective study. Compared to patients with none-low persistence of elevated total bile acid, the multivariate adjusted hazard ratios (95% confidence interval) were 2.37 (1.16–4.84), and 2.57 (1.28–5.16) for patients with medium, and high persistence of elevated total bile acid. Our findings identified persistence of elevated serum total bile acid as an independent risk factor of hepatocellular carcinoma in chronic hepatitis B patients. PMID:27905528

  7. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

    SciTech Connect

    Wu, Weibin; Zhu, Bo; Peng, Xiaomin; Zhou, Meiling; Jia, Dongwei; Gu, Jianxin

    2014-01-03

    Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activatio