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Sample records for reactivating hepatocyte nuclear

  1. Fibrates down-regulate IL-1-stimulated C-reactive protein gene expression in hepatocytes by reducing nuclear p50-NFκB-C/EBP-β complex formation

    NARCIS (Netherlands)

    Kleemann, R.; Gervois, P.P.; Verschuren, L.; Staels, B.; Princen, H.M.G.; Kooistra, T.

    2003-01-01

    C-reactive protein (CRP) is a major acute-phase protein in humans. Elevated plasma CRP levels are a risk factor for cardiovascular disease. CRP is predominantly expressed in hepatocytes and is induced by interleukin-1 (IL-1) and IL-6 under inflammatory situations, such as the acute phase. Fibrates

  2. Hepatocyte nuclear factor 4A improves hepatic differentiation of immortalized adult human hepatocytes and improves liver function and survival.

    Science.gov (United States)

    Hang, Hua-Lian; Liu, Xin-Yu; Wang, Hai-Tian; Xu, Ning; Bian, Jian-Min; Zhang, Jian-Jun; Xia, Lei; Xia, Qiang

    2017-11-15

    Immortalized human hepatocytes (IHH) could provide an unlimited supply of hepatocytes, but insufficient differentiation and phenotypic instability restrict their clinical application. This study aimed to determine the role of hepatocyte nuclear factor 4A (HNF4A) in hepatic differentiation of IHH, and whether encapsulation of IHH overexpressing HNF4A could improve liver function and survival in rats with acute liver failure (ALF). Primary human hepatocytes were transduced with lentivirus-mediated catalytic subunit of human telomerase reverse transcriptase (hTERT) to establish IHH. Cells were analyzed for telomerase activity, proliferative capacity, hepatocyte markers, and tumorigenicity (c-myc) expression. Hepatocyte markers, hepatocellular functions, and morphology were studied in the HNF4A-overexpressing IHH. Hepatocyte markers and karyotype analysis were completed in the primary hepatocytes using shRNA knockdown of HNF4A. Nuclear translocation of β-catenin was assessed. Rat models of ALF were treated with encapsulated IHH or HNF4A-overexpressing IHH. A HNF4A-positive IHH line was established, which was non-tumorigenic and conserved properties of primary hepatocytes. HNF4A overexpression significantly enhanced mRNA levels of genes related to hepatic differentiation in IHH. Urea levels were increased by the overexpression of HNF4A, as measured 24h after ammonium chloride addition, similar to that of primary hepatocytes. Chromosomal abnormalities were observed in primary hepatocytes transfected with HNF4A shRNA. HNF4α overexpression could significantly promote β-catenin activation. Transplantation of HNF4A overexpressing IHH resulted in better liver function and survival of rats with ALF compared with IHH. HNF4A improved hepatic differentiation of IHH. Transplantation of HNF4A-overexpressing IHH could improve the liver function and survival in a rat model of ALF. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Nuclear lactate dehydrogenase modulates histone modification in human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Castonguay, Zachary; Auger, Christopher; Thomas, Sean C.; Chahma, M’hamed; Appanna, Vasu D., E-mail: vappanna@laurentian.ca

    2014-11-07

    Highlights: • Nuclear LDH is up-regulated under oxidative stress. • SIRT1 is co-immunoprecipitated bound to nuclear LDH. • Nuclear LDH is involved in histone deacetylation and epigenetics. - Abstract: It is becoming increasingly apparent that the nucleus harbors metabolic enzymes that affect genetic transforming events. Here, we describe a nuclear isoform of lactate dehydrogenase (nLDH) and its ability to orchestrate histone deacetylation by controlling the availability of nicotinamide adenine dinucleotide (NAD{sup +}), a key ingredient of the sirtuin-1 (SIRT1) deacetylase system. There was an increase in the expression of nLDH concomitant with the presence of hydrogen peroxide (H{sub 2}O{sub 2}) in the culture medium. Under oxidative stress, the NAD{sup +} generated by nLDH resulted in the enhanced deacetylation of histones compared to the control hepatocytes despite no discernable change in the levels of SIRT1. There appeared to be an intimate association between nLDH and SIRT1 as these two enzymes co-immunoprecipitated. The ability of nLDH to regulate epigenetic modifications by manipulating NAD{sup +} reveals an intricate link between metabolism and the processing of genetic information.

  4. U.V.-enhanced reactivation of u.v.-irradiated herpes virus by primary cultures of rat hepatocytes

    International Nuclear Information System (INIS)

    Zurlo, J.; Yager, J.D.

    1984-01-01

    Carcinogen treatment of cultured mammalian cells prior to infection with u.v.-irradiated virus results in enhanced virus survival and mutagenesis suggesting the induction of SOS-type processes. In this paper, we report the development of a primary rat hepatocyte culture system to investigate cellular responses to DNA damage which may be relevant to hepatocarcinogenesis in vivo. We have obtained data demonstrating that enhanced reactivation of u.v.-irradiated Herpes simplex virus type 1 (HSV-1) occurs in hepatocytes irradiated with u.v. Cultured hepatocytes were pretreated with u.v. at the time of enhanced DNA synthesis. These treatments caused an inhibition followed by a recovery of DNA synthesis. At various times after pretreatment, the hepatocytes were infected with control or u.v.-irradiated HSV-1 at low multiplicity, and virus survival was measured by direct plaque assay. U.v.-irradiated HSV-1 exhibited the expected two-component survival curve in control or u.v. pretreated hepatocytes. The magnitude of enhanced reactivation of HSV-1 was dependent on the u.v. dose to the hepatocytes, the time of infection following u.v. pretreatment, and the level of DNA synthesis at the time of pretreatment. These results suggest that u.v. treatment of rat hepatocytes causes the induction of SOS-type functions that may have a role in the initiation of hepatocarcinogenesis

  5. Nuclear reactivity control configuration

    International Nuclear Information System (INIS)

    Bingham, B.E.; DeMars, R.V.

    1990-01-01

    This patent describes a neutron flux control component assembly for use in a nuclear reactor. It comprises: at least three V-shaped close fitting carrier sheets nested together to provide a Y-shaped cross section and which are movable relative to each other along their longitudinal axis; at least three substantially identical neutron poison segments, one of each of the carrier sheets, movable between overlapped and exposed positions in response to movement of the carrier sheets; and each of the poison segments having a width grater than three times the effective thickness of the assembly of overlapping poison segments and capable of absorbing at least eighty percent of the neutrons that strike its surface

  6. The role of hepatocyte nuclear factor 4 alpha in development and progression of liver diseases

    Directory of Open Access Journals (Sweden)

    YANG Jinlian

    2016-02-01

    Full Text Available Hepatocyte nuclear factor 4 alpha (HNF4α, a member of the nuclear receptor superfamily, has a high expression level in mature hepatocytes. HNF4α can regulate hepatocyte-specific gene expression at a transcriptional level, promote hepatocyte development and differentiation, participate in establishment and maintenance of hepatocyte polarity, and enhance the synthetic, metabolic, and detoxifying functions of the liver. Through inhibiting the activation of hepatic stellate cells, reversing epithelial-mesenchymal transition, and inhibiting the proliferation, invasion, and metastasis of hepatoma cells, HNF4α may be involved in the development and progression of various liver diseases including liver fibrosis, liver cirrhosis, and hepatocellular carcinoma. This paper elaborates on the biological functions of HNF4α, and summarizes and analyzes the research advances in the mechanisms of action of HNF4α in the pathological process of liver diseases, in order to provide references for further investigation of the potential targeted therapies for liver diseases.

  7. Trifluoperazine inhibits acetaminophen-induced hepatotoxicity and hepatic reactive nitrogen formation in mice and in freshly isolated hepatocytes

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    Sudip Banerjee

    Full Text Available The hepatotoxicity of acetaminophen (APAP occurs by initial metabolism to N-acetyl-p-benzoquinone imine which depletes GSH and forms APAP-protein adducts. Subsequently, the reactive nitrogen species peroxynitrite is formed from nitric oxide (NO and superoxide leading to 3-nitrotyrosine in proteins. Toxicity occurs with inhibited mitochondrial function. We previously reported that in hepatocytes the nNOS (NOS1 inhibitor NANT inhibited APAP toxicity, reactive nitrogen and oxygen species formation, and mitochondrial dysfunction. In this work we examined the effect of trifluoperazine (TFP, a calmodulin antagonist that inhibits calcium induced nNOS activation, on APAP hepatotoxicity and reactive nitrogen formation in murine hepatocytes and in vivo. In freshly isolated hepatocytes TFP inhibited APAP induced toxicity, reactive nitrogen formation (NO, GSNO, and 3-nitrotyrosine in protein, reactive oxygen formation (superoxide, loss of mitochondrial membrane potential, decreased ATP production, decreased oxygen consumption rate, and increased NADH accumulation. TFP did not alter APAP induced GSH depletion in the hepatocytes or the formation of APAP protein adducts which indicated that reactive metabolite formation was not inhibited. Since we previously reported that TFP inhibits the hepatotoxicity of APAP in mice without altering hepatic APAP-protein adduct formation, we examined the APAP treated mouse livers for evidence of reactive nitrogen formation. 3-Nitrotyrosine in hepatic proteins and GSNO were significantly increased in APAP treated mouse livers and decreased in the livers of mice treated with APAP plus TFP. These data are consistent with a hypothesis that APAP hepatotoxicity occurs with altered calcium metabolism, activation of nNOS leading to increased reactive nitrogen formation, and mitochondrial dysfunction. Keywords: Acetaminophen, Neuronal nitric oxide, Oxidative stress, Mitochondria

  8. Deletion of hepatocyte nuclear factor-1-beta in an infant with prune belly syndrome.

    Science.gov (United States)

    Haeri, Sina; Devers, Patricia L; Kaiser-Rogers, Kathleen A; Moylan, Vincent J; Torchia, Beth S; Horton, Amanda L; Wolfe, Honor M; Aylsworth, Arthur S

    2010-08-01

    Prune belly syndrome is a rare congenital disorder characterized by deficiency of abdominal wall muscles, cryptorchidism, and urinary tract anomalies. We have had the opportunity to study a baby with prune belly syndrome associated with an apparently de novo 1.3-megabase interstitial 17q12 microdeletion that includes the hepatocyte nuclear factor-1-beta gene at 17q12. One previous patient, an adult, has been reported with prune belly syndrome and a hepatocyte nuclear factor-1-beta microdeletion. Hepatocyte nuclear factor-1-beta is a widely expressed transcription factor that regulates tissue-specific gene expression and is expressed in numerous tissues including mesonephric duct derivatives, the renal tubule of the metanephros, and the developing prostate of the mouse. Mutations in hepatocyte nuclear factor-1-beta cause the "renal cysts and diabetes syndrome," isolated renal cystic dysplasia, and a variety of other malformations. Based on its expression pattern and the observation of two affected cases, we propose that haploinsufficiency of hepatocyte nuclear factor-1-beta may be causally related to the production of the prune belly syndrome phenotype through a mechanism of prostatic and ureteral hypoplasia that results in severe obstructive uropathy with urinary tract and abdominal distension. Copyright Thieme Medical Publishers.

  9. Formation of glutathione conjugates by reactive metabolites of vinylidene chloride in microsomes and isolated hepatocytes

    International Nuclear Information System (INIS)

    Liebler, D.C.; Meredith, M.J.; Guengerich, F.P.

    1985-01-01

    Oxidation of the vinyl halide carcinogen and hepatotoxin vinylidene chloride (VDC) by microsomal cytochrome P-450 yields 2,2-dichloroacetaldehyde, 2-chloroacetyl chloride, 2-chloroacetic acid, and 1,1-dichloroethylene oxide. The roles of these metabolites in covalent modification of proteins and reduced glutathione (GSH) were examined. 2-Chloroacetyl chloride reacted with model thiols at least 10(3)-fold faster than did 1,1-dichloroethylene oxide and at least 10(5)-fold faster than did 2,2-dichloroacetaldehyde or 2-chloroacetic acid. Microsomal covalent binding of [ 14 C]VDC was inhibited by GSH but not by lysine, suggesting that protein thiols, rather than amino groups, are major targets. Liver microsomes catalyzed the formation of three GSH:VDC metabolite conjugates, identified as S-(2,2-dichloro-1-hydroxy)ethylglutathione, 2-(S-glutathionyl)acetate, and S-(2-glutathionyl)acetylglutathione, a novel conjugate containing both stable (thioether) and labile (thioester) linkages. The latter two conjugates also were formed in isolated rat hepatocytes and measurable amounts of 2-(S-glutathionyl)acetate were released into the incubation medium. Both 2-(S-glutathionyl)acetate and S-(2-glutathionyl)acetylglutathione were formed with [ 35 S]GSH added to the hepatic medium, indicating that reactive VDC metabolites are capable of crossing the plasma membrane to react with extracellular targets. Unlabeled S-(2-glutathionyl)-acetylglutathione underwent carbonyl substitution with added [ 35 S]GSH, suggesting that this conjugate may participate in modification of protein thiols. This conjugate also underwent hydrolysis with a half-life of approximately 3 hr. GSH:VDC metabolite conjugates may serve as accessible models for labile covalent adducts formed between VDC metabolites and protein thiols

  10. Organization of the lamin scaffold in the internal nuclear matrix of normal and transformed hepatocytes

    International Nuclear Information System (INIS)

    Barboro, Paola; D'Arrigo, Cristina; Repaci, Erica; Patrone, Eligio; Balbi, Cecilia

    2010-01-01

    Nuclear lamins are among the more abundant proteins making up the internal nuclear matrix, but very little is known about their structure in the nucleoplasm. Using immunoelectron microscopy, we demonstrate the organization of lamins in the nuclear matrix isolated from rat hepatocytes for the first time. Lamin epitopes are arrayed both in locally ordered clusters and in quasi-regular rows. Fourier filtering of the images demonstrates that the epitopes are placed at the nodes and halfway between the nodes of square or rhombic lattices that are about 50 nm on each side, as well as along rows at regular ∼25-nm intervals. In addition, we have compared this structure with that of the internal nuclear matrix isolated from persistent hepatocyte nodules. In transformed hepatocytes, the islands of lamin lattice are lost, and only a partial regularity in the rows of gold particles remains. We suggest that orthogonal lattice assembly might be an intrinsic property of lamin molecules, and that the disassembly may be triggered by simple molecular events such as phosphorylation.

  11. Dysplastic hepatocytes develop nuclear inclusions in a mouse model of viral hepatitis.

    Directory of Open Access Journals (Sweden)

    Priyanka Thakur

    Full Text Available Viral hepatitis resulting in chronic liver disease is an important clinical challenge and insight into the cellular processes that drive pathogenesis will be critical in order to develop new diagnostic and therapeutic options. Nuclear inclusions in viral and non-viral hepatitis are well documented and have diagnostic significance in some disease contexts. However, the origins and functional consequences of these nuclear inclusions remain elusive. To date the clinical observation of nuclear inclusions in viral and non-viral hepatitis has not been explored at depth in murine models of liver disease. Herein, we report that in a transgenic model of hepatitis B surface antigen mediated hepatitis, murine hepatocytes exhibit nuclear inclusions. Cells bearing nuclear inclusions were more likely to express markers of cell proliferation. We also established a correlation between these inclusions and oxidative stress. N-acetyl cysteine treatment effectively reduced oxidative stress levels, relieved endoplasmic reticulum (ER stress, and the number of nuclear inclusions we observed in the transgenic mice. Our results suggest that the presence of nuclear inclusions in hepatocytes correlates with oxidative stress and cellular proliferation in a model of antigen mediated hepatitis.

  12. Induction of unscheduled DNA synthesis on the nuclear matrix of rat hepatocytes after whole-body γ-irradiation

    International Nuclear Information System (INIS)

    Bezlepkin, V.G.; Malinovskij, Yu.Yu.; Kuznetsova, E.A.; Namvar, R.A.; Gaziev, A.I.

    1986-01-01

    DNA synthesis in hepatocytes was studied by incorporation of [ 3 H]thymidine administered of portal vein of γ-irradiated (80 Gy) rats. It was shown that the rate of replicative DNA synthesis decreased in hepatocytes of the regenerating liver and unscheduled DNA synthesis was induced at the nuclear matrix of resting cells of the intact liver. In addition to repair synthesis, DNA synthesis resembling replicative one (''aberrant'' DNA synthesis) accounts for a considerable fraction of γ-radiation-induced synthesis of DNA at the nuclear matrix

  13. A Polymorphism in Hepatocyte Nuclear Factor 1 Alpha, rs7310409, Is Associated with Left Main Coronary Artery Disease

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    Rui Liu

    2014-01-01

    Full Text Available Coronary artery disease is the leading cause of mortality and morbidity in the world. Left main coronary artery disease (LMCAD is a particularly severe phenotypic form of CAD and has a genetic basis. We hypothesized that some inflammation- and hyperhomocysteinemia-related gene polymorphisms may contribute to LMCAD susceptibility in a Chinese population. We studied the association between polymorphisms in the genes hepatocyte nuclear factor 1 alpha (HNF1A; rs7310409, G/A, C-reactive protein (rs1800947 and rs3093059 T/C, methylenetetrahydrofolate reductase (rs1801133, C/T, and methylenetetrahydrofolate dehydrogenase (rs1076991, A/G in 402 LMCAD and 804 more peripheral CAD patients in a Chinese population. Genotyping was performed using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry method. When the HNF1A rs7310409 GG homozygote genotype was used as the reference group, both the individual, GA and AA, and combined GA/AA genotypes were associated with an increased risk of LMCAD. This single nucleotide polymorphism (rs7310409 is strongly associated with plasma CRP levels. In conclusion, the present study provides evidence that the HNF1A rs7310409 G/A functional polymorphism may contribute to the risk of LMCAD.

  14. Reversibility of hepatocyte nuclear modifications in mice fed on genetically modified soybean

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    M Malatesta

    2009-06-01

    Full Text Available In the literature, the reports on the effects of a genetically modified (GM diet are scanty and heterogeneous; in particular, no direct evidence has so far been reported that GM food may affect human or animal health. Hepatocytes represent a suitable model for monitoring the effects of a GM diet, the liver potentially being a primary target. In a previous study, we demonstrated that some modifications occur in hepatocyte nuclei of mice fed on GM soybean. In order to elucidate whether such modifications can be reversed, in the present study, 3 months old mice fed on GM soybean since their weaning were submitted to a diet containing wild type soybean only, for one month. In parallel, to investigate the influence of GM soybean on adult individuals, mice fed on wild type soybean were changed to a GM diet, for the same time. Using immunoelectron microscopy, we demonstrated that a one-month diet reversion can influence some nuclear features in adult mice, restoring typical characteristics of controls in GM-fed animals, and inducing in control mice modifications similar to those observed in animals fed on GM soybean from weaning. This suggests that the modifications related to GM soybean are potentially reversible, but also that some modifications are inducible in adult organisms in a short time.

  15. Molecular genetics and phenotypic characteristics of MODY caused by hepatocyte nuclear factor 4alpha mutations in a large European collection.

    NARCIS (Netherlands)

    Pearson, E.R.; Pruhova, S.; Tack, C.J.J.; Johansen, A.; Castleden, H.A.; Lumb, P.J.; Wierzbicki, A.S.; Clark, P.M.; Lebl, J.; Pedersen, O.; Ellard, S.; Hansen, T.; Hattersley, A.T.

    2005-01-01

    AIMS/HYPOTHESIS: Heterozygous mutations in the gene of the transcription factor hepatocyte nuclear factor 4alpha (HNF-4alpha) are considered a rare cause of MODY with only 14 mutations reported to date. The description of the phenotype is limited to single families. We investigated the genetics and

  16. A novel phenotype of a hepatocyte nuclear factor homeobox A (HNF1A) gene mutation, presenting with neonatal cholestasis

    NARCIS (Netherlands)

    de Vries, Aleida G. M.; Bakker-van Waarde, Willie M.; Dassel, Anne C. M.; Losekoot, Monique; Duiker, Evelien W.; Gouw, Annette S. H.; Bodewes, Frank A. J. A.

    We report a novel phenotype of a hepatocyte nuclear factor homeobox A (HNF1A) mutation (heterozygote c.130dup, p.Leu44fs) presenting with transient neonatal cholestasis, subsequently followed by persistent elevation of transaminases, maturity-onset diabetes of the young (MODY) type 3 and

  17. Hepatocyte DACH1 Is Increased in Obesity via Nuclear Exclusion of HDAC4 and Promotes Hepatic Insulin Resistance

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    Lale Ozcan

    2016-06-01

    Full Text Available Defective insulin signaling in hepatocytes is a key factor in type 2 diabetes. In obesity, activation of calcium/calmodulin-dependent protein kinase II (CaMKII in hepatocytes suppresses ATF6, which triggers a PERK-ATF4-TRB3 pathway that disrupts insulin signaling. Elucidating how CaMKII suppresses ATF6 is therefore essential to understanding this insulin resistance pathway. We show that CaMKII phosphorylates and blocks nuclear translocation of histone deacetylase 4 (HDAC4. As a result, HDAC4-mediated SUMOylation of the corepressor DACH1 is decreased, which protects DACH1 from proteasomal degradation. DACH1, together with nuclear receptor corepressor (NCOR, represses Atf6 transcription, leading to activation of the PERK-TRB3 pathway and defective insulin signaling. DACH1 is increased in the livers of obese mice and humans, and treatment of obese mice with liver-targeted constitutively nuclear HDAC4 or DACH1 small hairpin RNA (shRNA increases ATF6, improves hepatocyte insulin signaling, and protects against hyperglycemia and hyperinsulinemia. Thus, DACH1-mediated corepression in hepatocytes emerges as an important link between obesity and insulin resistance.

  18. Zyxin regulates migration of renal epithelial cells through activation of hepatocyte nuclear factor-1β.

    Science.gov (United States)

    Choi, Yun-Hee; McNally, Brian T; Igarashi, Peter

    2013-07-01

    Hepatocyte nuclear factor-1β (HNF-1β) is an epithelial tissue-specific transcription factor that regulates gene expression in the kidney, liver, pancreas, intestine, and other organs. Mutations of HNF-1β in humans produce renal cysts and congenital kidney anomalies. Here, we identify the LIM-domain protein zyxin as a novel binding partner of HNF-1β in renal epithelial cells. Zyxin shuttles to the nucleus where it colocalizes with HNF-1β. Immunoprecipitation of zyxin in leptomycin B-treated cells results in coprecipitation of HNF-1β. The protein interaction requires the second LIM domain of zyxin and two distinct domains of HNF-1β. Overexpression of zyxin stimulates the transcriptional activity of HNF-1β, whereas small interfering RNA silencing of zyxin inhibits HNF-1β-dependent transcription. Epidermal growth factor (EGF) induces translocation of zyxin into the nucleus and stimulates HNF-1β-dependent promoter activity. The EGF-mediated nuclear translocation of zyxin requires activation of Akt. Expression of dominant-negative mutant HNF-1β, knockdown of zyxin, or inhibition of Akt inhibits EGF-stimulated cell migration. These findings reveal a novel pathway by which extracellular signals are transmitted to the nucleus to regulate the activity of a transcription factor that is essential for renal epithelial differentiation.

  19. Growth hormone-specific induction of the nuclear localization of porcine growth hormone receptor in porcine hepatocytes.

    Science.gov (United States)

    Lan, H N; Hong, P; Li, R N; Shan, A S; Zheng, X

    2017-10-01

    The phenomenon of nuclear translocation of growth hormone receptor (GHR) in human, rat, and fish has been reported. To date, this phenomenon has not been described in a domestic animal (such as pig). In addition, the molecular mechanisms of GHR nuclear translocation have not been thoroughly elucidated. To this end, porcine hepatocytes were isolated and used as a cell model. We observed that porcine growth hormone (pGH) can induce porcine GHR's nuclear localization in porcine hepatocytes. Subsequently, the dynamics of pGH-induced pGHR's nuclear localization were analyzed and demonstrated that pGHR's nuclear localization occurs in a time-dependent manner. Next, we explored the mechanism of pGHR nuclear localization using different pGHR ligands, and we demonstrated that pGHR's nuclear translocation is GH(s)-dependent. We also observed that pGHR translocates into cell nuclei in a pGH dimerization-dependent fashion, whereas further experiments indicated that IMPα/β is involved in the nuclear translocation of the pGH-pGHR dimer. The pGH-pGHR dimer may form a pGH-GHR-JAK2 multiple complex in cell nuclei, which would suggest that similar to its function in the cell membrane, the nuclear-localized pGH-pGHR dimer might still have the ability to signal. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Carboxylesterase 1 Is Regulated by Hepatocyte Nuclear Factor 4α and Protects Against Alcohol- and MCD diet-induced Liver Injury.

    Science.gov (United States)

    Xu, Jiesi; Xu, Yang; Li, Yuanyuan; Jadhav, Kavita; You, Min; Yin, Liya; Zhang, Yanqiao

    2016-04-14

    The liver is a major organ that controls hepatic and systemic homeostasis. Dysregulation of liver metabolism may cause liver injury. Previous studies have demonstrated that carboxylesterase 1 (CES1) regulates hepatic triglyceride metabolism and protects against liver steatosis. In the present study, we investigated whether CES1 played a role in the development of alcoholic liver disease (ALD) and methionine and choline-deficient (MCD) diet-induced liver injury. Both hepatocyte nuclear factor 4α (HNF4α) and CES1 were markedly reduced in patients with alcoholic steatohepatitis. Alcohol repressed both HNF4α and CES1 expression in primary hepatocytes. HNF4α regulated CES1 expression by directly binding to the proximal promoter of CES1. Global inactivation of CES1 aggravated alcohol- or MCD diet-induced liver inflammation and liver injury, likely as a result of increased production of acetaldehyde and reactive oxygen species and mitochondrial dysfunctions. Knockdown of hepatic CES1 exacerbated ethanol-induced steatohepatitis. These data indicate that CES1 plays a crucial role in protection against alcohol- or MCD diet-induced liver injury.

  1. Phenotypic screening of hepatocyte nuclear factor (HNF) 4-γ receptor knockout mice

    International Nuclear Information System (INIS)

    Gerdin, Anna Karin; Surve, Vikas V.; Joensson, Marie; Bjursell, Mikael; Bjoerkman, Maria; Edenro, Anne; Schuelke, Meint; Saad, Alaa; Bjurstroem, Sivert; Lundgren, Elisabeth Jensen; Snaith, Michael; Fransson-Steen, Ronny; Toernell, Jan; Berg, Anna-Lena; Bohlooly-Y, Mohammad

    2006-01-01

    Using the mouse as a model organism in pharmaceutical research presents unique advantages as its physiology in many ways resembles the human physiology, it also has a relatively short generation time, low breeding and maintenance costs, and is available in a wide variety of inbred strains. The ability to genetically modify mouse embryonic stem cells to generate mouse models that better mimic human disease is another advantage. In the present study, a comprehensive phenotypic screening protocol is applied to elucidate the phenotype of a novel mouse knockout model of hepatocyte nuclear factor (HNF) 4-γ. HNF4-γ is expressed in the kidneys, gut, pancreas, and testis. First level of the screen is aimed at general health, morphologic appearance, normal cage behaviour, and gross neurological functions. The second level of the screen looks at metabolic characteristics and lung function. The third level of the screen investigates behaviour more in-depth and the fourth level consists of a thorough pathological characterisation, blood chemistry, haematology, and bone marrow analysis. When compared with littermate wild-type mice (HNF4-γ +/+ ), the HNF4-γ knockout (HNF4-γ -/- ) mice had lowered energy expenditure and locomotor activity during night time that resulted in a higher body weight despite having reduced intake of food and water. HNF4-γ -/- mice were less inclined to build nest and were found to spend more time in a passive state during the forced swim test

  2. Multiple post-translational modifications in hepatocyte nuclear factor 4α

    International Nuclear Information System (INIS)

    Yokoyama, Atsushi; Katsura, Shogo; Ito, Ryo; Hashiba, Waka; Sekine, Hiroki; Fujiki, Ryoji; Kato, Shigeaki

    2011-01-01

    Highlights: → We performed comprehensive PTM analysis for HNF4α protein. → We identified 8 PTMs in HNF4α protein including newly identified PTMs. → Among them, we found acetylation at lysine 458 was one of the prime PTMs for HNF4α function. → Acetylation at lysine 458 was inhibitory for HNF4α transcription function. → This modification fluctuated in response to extracellular condition. -- Abstract: To investigate the role of post-translational modifications (PTMs) in the hepatocyte nuclear factor 4α (HNF4α)-mediated transcription, we took a comprehensive survey of PTMs in HNF4α protein by massspectrometry and identified totally 8 PTM sites including newly identified ubiquitilation and acetylation sites. To assess the impact of identified PTMs in HNF4α-function, we introduced point mutations at the identified PTM sites and, tested transcriptional activity of the HNF4α. Among the point-mutations, an acetylation site at lysine 458 was found significant in the HNF4α-mediated transcriptional control. An acetylation negative mutant at lysine 458 showed an increased transcriptional activity by about 2-fold, while an acetylation mimic mutant had a lowered transcriptional activation. Furthermore, this acetylation appeared to be fluctuated in response to extracellular nutrient conditions. Thus, by applying an comprehensive analysis of PTMs, multiple PTMs were newly identified in HNF4α and unexpected role of an HNF4α acetylation could be uncovered.

  3. Fail-safe reactivity compensation method for a nuclear reactor

    Science.gov (United States)

    Nygaard, Erik T.; Angelo, Peter L.; Aase, Scott B.

    2018-01-23

    The present invention relates generally to the field of compensation methods for nuclear reactors and, in particular to a method for fail-safe reactivity compensation in solution-type nuclear reactors. In one embodiment, the fail-safe reactivity compensation method of the present invention augments other control methods for a nuclear reactor. In still another embodiment, the fail-safe reactivity compensation method of the present invention permits one to control a nuclear reaction in a nuclear reactor through a method that does not rely on moving components into or out of a reactor core, nor does the method of the present invention rely on the constant repositioning of control rods within a nuclear reactor in order to maintain a critical state.

  4. Formation for the calculation of reactivity without nuclear power history

    International Nuclear Information System (INIS)

    Suescun Diaz, Daniel; Senra Martinez, Aquilino; Carvalho Da Silva, Fernando

    2007-01-01

    This paper presents a new method for the solution of the inverse point kinetics equation. This method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. With the imposition of conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has very special characteristics, amongst which the possibility of using longer sampling period, and the possibility of restarting the calculation, after its interruption, allowing the calculation of reactivity in a non-continuous way. Beside that, the reactivity can be obtained independent of the nuclear power memory. (author)

  5. The role of hepatocyte nuclear factor 4-alpha in perfluorooctanoic acid- and perfluorooctanesulfonic acid-induced hepatocellular dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Beggs, Kevin M., E-mail: kbeggs2@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); McGreal, Steven R., E-mail: smcgreal@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); McCarthy, Alex [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); Gunewardena, Sumedha, E-mail: sgunewardena@kumc.edu [Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Blvd, 2027 HLSIC, Kansas City, KS 66160 (United States); Lampe, Jed N., E-mail: jlampe@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); Lau, Christoper, E-mail: lau.christopher@epa.gov [Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Apte, Udayan, E-mail: uapte@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States)

    2016-08-01

    Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), chemicals present in a multitude of consumer products, are persistent organic pollutants. Both compounds induce hepatotoxic effects in rodents, including steatosis, hepatomegaly and liver cancer. The mechanisms of PFOA- and PFOS-induced hepatic dysfunction are not completely understood. We present evidence that PFOA and PFOS induce their hepatic effects via targeting hepatocyte nuclear factor 4-alpha (HNF4α). Human hepatocytes treated with PFOA and PFOS at a concentration relevant to occupational exposure caused a decrease in HNF4α protein without affecting HNF4α mRNA or causing cell death. RNA sequencing analysis combined with Ingenuity Pathway Analysis of global gene expression changes in human hepatocytes treated with PFOA or PFOS indicated alterations in the expression of genes involved in lipid metabolism and tumorigenesis, several of which are regulated by HNF4α. Further investigation of specific HNF4α target gene expression revealed that PFOA and PFOS could promote cellular dedifferentiation and increase cell proliferation by down regulating positive targets (differentiation genes such as CYP7A1) and inducing negative targets of HNF4α (pro-mitogenic genes such as CCND1). Furthermore, in silico docking simulations indicated that PFOA and PFOS could directly interact with HNF4α in a similar manner to endogenous fatty acids. Collectively, these results highlight HNF4α degradation as novel mechanism of PFOA and PFOS-mediated steatosis and tumorigenesis in human livers. - Highlights: • PFOA and PFOS cause decreased HNF4α protein expression in human hepatocytes. • PFOA and PFOS promote changes associated with lipid metabolism and carcinogenesis. • PFOA and PFOS induced changes in gene expression associated with cellular dedifferentiation. • PFOA and PFOS induce expression of Nanog, a transcription factor involved in stem cell development.

  6. Hepatocyte nuclear factor 1-alpha mutation in normal glucose-tolerant subjects and early-onset type 2 diabetic patients

    OpenAIRE

    Lim, Dong Mee; Huh, Nam; Park, Keun Yong

    2008-01-01

    Background/Aims The prevalence of diabetes in Korea is reported to be approximately 10%, but cases of maturity-onset diabetes of the young (MODY) are rare in Korea. A diagnostic technique for autosomal dominant MODY is being actively sought. In this regard, we used a DNA chip to investigate the frequency of mutations of the MODY3 gene (hepatocyte nuclear factor-1?) in Korean patients with early-onset type 2 diabetes. Methods The genomic DNA of 30 normal individuals [age, 24.9?8.6 years] and 2...

  7. Increased expression of hepatocyte nuclear factor 4 alpha transcribed by promoter 2 indicates a poor prognosis in hepatocellular carcinoma

    OpenAIRE

    Cai, Shao-hang; Lu, Shi-xun; Liu, Li-li; Zhang, Chris Zhiyi; Yun, Jing-ping

    2017-01-01

    Background: Hepatocyte nuclear factor 4 alpha (HNF4α) plays an important role in tumourigenesis. There is growing evidence indicating that HNF4α transcribed by promoter 1 (P1-HNF4α) is expressed at relatively low levels in HCC and its presence predicts a favourable outcome for hepatocellular carcinoma (HCC) patients. However, the role of HNF4α transcribed by promoter 2 (P2-HNF4α) in HCC remains unclear. Methods: A total of 615 HCC specimens were obtained to construct tissue microarrays and pe...

  8. Transcriptional regulation of the human Liver X Receptor α gene by Hepatocyte Nuclear Factor 4α

    Energy Technology Data Exchange (ETDEWEB)

    Theofilatos, Dimitris; Anestis, Aristomenis [University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, Heraklion, 71003, Crete (Greece); Hashimoto, Koshi [Department of Preemptive Medicine and Metabolism, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-city, Tokyo, 113-8510 (Japan); Kardassis, Dimitris, E-mail: kardasis@imbb.forth.gr [University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology of Hellas, Heraklion, 71003, Crete (Greece)

    2016-01-15

    Liver X Receptors (LXRs) are sterol-activated transcription factors that play major roles in cellular cholesterol homeostasis, HDL biogenesis and reverse cholesterol transport. The aim of the present study was to investigate the mechanisms that control the expression of the human LXRα gene in hepatic cells. A series of reporter plasmids containing consecutive 5′ deletions of the hLXRα promoter upstream of the luciferase gene were constructed and the activity of each construct was measured in HepG2 cells. This analysis showed that the activity of the human LXRα promoter was significantly reduced by deleting the −111 to −42 region suggesting the presence of positive regulatory elements in this short proximal fragment. Bioinformatics data including motif search and ChIP-Seq revealed the presence of a potential binding motif for Hepatocyte Nuclear Factor 4 α (HNF-4α) in this area. Overexpression of HNF-4α in HEK 293T cells increased the expression of all LXRα promoter constructs except −42/+384. In line, silencing the expression of endogenous HNF-4α in HepG2 cells was associated with reduced LXRα protein levels and reduced activity of the −111/+384 LXRα promoter but not of the −42/+384 promoter. Using ChiP assays in HepG2 cells combined with DNAP assays we mapped the novel HNF-4α specific binding motif (H4-SBM) in the −50 to −40 region of the human LXRα promoter. A triple mutation in this H4-SBM abolished HNF-4α binding and reduced the activity of the promoter to 65% relative to the wild type. Furthermore, the mutant promoter could not be transactivated by HNF-4α. In conclusion, our data indicate that HNF-4α may have a wider role in cell and plasma cholesterol homeostasis by controlling the expression of LXRα in hepatic cells. - Highlights: • The human LXRα promoter contains a HNF-4α specific binding motif in the proximal −50/−40 region. • Mutations in this motif abolished HNF4α binding and transactivation of the h

  9. Transcriptional regulation of the human Liver X Receptor α gene by Hepatocyte Nuclear Factor 4α

    International Nuclear Information System (INIS)

    Theofilatos, Dimitris; Anestis, Aristomenis; Hashimoto, Koshi; Kardassis, Dimitris

    2016-01-01

    Liver X Receptors (LXRs) are sterol-activated transcription factors that play major roles in cellular cholesterol homeostasis, HDL biogenesis and reverse cholesterol transport. The aim of the present study was to investigate the mechanisms that control the expression of the human LXRα gene in hepatic cells. A series of reporter plasmids containing consecutive 5′ deletions of the hLXRα promoter upstream of the luciferase gene were constructed and the activity of each construct was measured in HepG2 cells. This analysis showed that the activity of the human LXRα promoter was significantly reduced by deleting the −111 to −42 region suggesting the presence of positive regulatory elements in this short proximal fragment. Bioinformatics data including motif search and ChIP-Seq revealed the presence of a potential binding motif for Hepatocyte Nuclear Factor 4 α (HNF-4α) in this area. Overexpression of HNF-4α in HEK 293T cells increased the expression of all LXRα promoter constructs except −42/+384. In line, silencing the expression of endogenous HNF-4α in HepG2 cells was associated with reduced LXRα protein levels and reduced activity of the −111/+384 LXRα promoter but not of the −42/+384 promoter. Using ChiP assays in HepG2 cells combined with DNAP assays we mapped the novel HNF-4α specific binding motif (H4-SBM) in the −50 to −40 region of the human LXRα promoter. A triple mutation in this H4-SBM abolished HNF-4α binding and reduced the activity of the promoter to 65% relative to the wild type. Furthermore, the mutant promoter could not be transactivated by HNF-4α. In conclusion, our data indicate that HNF-4α may have a wider role in cell and plasma cholesterol homeostasis by controlling the expression of LXRα in hepatic cells. - Highlights: • The human LXRα promoter contains a HNF-4α specific binding motif in the proximal −50/−40 region. • Mutations in this motif abolished HNF4α binding and transactivation of the h

  10. Nuclear reactivity control using laser induced polarization

    International Nuclear Information System (INIS)

    Bowman, C.D.

    1990-01-01

    This patent describes a control element for reactivity control of a fission source provides an atomic density of 3 He in a control volume which is effective to control criticality as the 3 He is spin-polarized. Spin-polarization of the 3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the 3 He for spin-polarizing the 3 He. An alkali-metal vapor may be included with the 3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with 3 He to spin-polarize the 3 He atoms

  11. Reactivation of the Argentine nuclear plan

    International Nuclear Information System (INIS)

    Rey, Francisco C.

    2007-01-01

    The Argentine Government, in a ceremony held at the Government House and headed by the President of the Republic, announced on the 23th. of August, 2006 a new plan for the nuclear activity. The Argentine Atomic Energy Commission considers this plan as the relaunching of the nuclear activity in the country, made with a clear strategic vision and based on the same premises took into account fifty seven years ago when the Atomic Energy Commission was created. (author) [es

  12. The nuclear higher-order structure defined by the set of topological relationships between DNA and the nuclear matrix is species-specific in hepatocytes.

    Science.gov (United States)

    Silva-Santiago, Evangelina; Pardo, Juan Pablo; Hernández-Muñoz, Rolando; Aranda-Anzaldo, Armando

    2017-01-15

    During the interphase the nuclear DNA of metazoan cells is organized in supercoiled loops anchored to constituents of a nuclear substructure or compartment known as the nuclear matrix. The stable interactions between DNA and the nuclear matrix (NM) correspond to a set of topological relationships that define a nuclear higher-order structure (NHOS). Current evidence suggests that the NHOS is cell-type-specific. Biophysical evidence and theoretical models suggest that thermodynamic and structural constraints drive the actualization of DNA-NM interactions. However, if the topological relationships between DNA and the NM were the subject of any biological constraint with functional significance then they must be adaptive and thus be positively selected by natural selection and they should be reasonably conserved, at least within closely related species. We carried out a coarse-grained, comparative evaluation of the DNA-NM topological relationships in primary hepatocytes from two closely related mammals: rat and mouse, by determining the relative position to the NM of a limited set of target sequences corresponding to highly-conserved genomic regions that also represent a sample of distinct chromosome territories within the interphase nucleus. Our results indicate that the pattern of topological relationships between DNA and the NM is not conserved between the hepatocytes of the two closely related species, suggesting that the NHOS, like the karyotype, is species-specific. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Diclofenac inhibits tumor necrosis factor-α-induced nuclear factor-κB activation causing synergistic hepatocyte apoptosis.

    Science.gov (United States)

    Fredriksson, Lisa; Herpers, Bram; Benedetti, Giulia; Matadin, Quraisha; Puigvert, Jordi C; de Bont, Hans; Dragovic, Sanja; Vermeulen, Nico P E; Commandeur, Jan N M; Danen, Erik; de Graauw, Marjo; van de Water, Bob

    2011-06-01

    Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by diclofenac and the proinflammatory cytokine tumor necrosis factor α (TNF-α). HepG2 cells were treated with diclofenac followed by TNF-α challenge and subsequent evaluation of necrosis and apoptosis. Diclofenac caused a mild apoptosis of HepG2 cells, which was strongly potentiated by TNF-α. A focused apoptosis machinery short interference RNA (siRNA) library screen identified that this TNF-α-mediated enhancement involved activation of caspase-3 through a caspase-8/Bid/APAF1 pathway. Diclofenac itself induced sustained activation of c-Jun N-terminal kinase (JNK) and inhibition of JNK decreased both diclofenac and diclofenac/TNF-α-induced apoptosis. Live cell imaging of GFPp65/RelA showed that diclofenac dampened the TNF-α-mediated nuclear factor kappaB (NF-κB) translocation oscillation in association with reduced NF-κB transcriptional activity. This was associated with inhibition by diclofenac of the TNF-α-induced phosphorylation of the inhibitor of NF-κB alpha (IκBα). Finally, inhibition of IκB kinase β (IKKβ) with BMS-345541 as well as stable lentiviral short hairpin RNA (shRNA)-based knockdown of p65/RelA sensitized hepatocytes towards diclofenac/TNF-α-induced cytotoxicity. Together, our data suggest a model whereby diclofenac-mediated stress signaling suppresses TNF-α-induced survival signaling routes and sensitizes cells to apoptosis. Copyright © 2011 American Association for the Study of Liver Diseases.

  14. Reactive adsorption: A cleaner technology in nuclear power plants

    International Nuclear Information System (INIS)

    Marton, G.; Szanya, T.; Hanak, L.

    1996-01-01

    Cleaner technology prefers work with minimal loss and the wastes cause the less environmental damages. In the spirit of the previous sentence in the present paper reactive adsorption is investigated for the removal of radioactive nuclides from nuclear power plant decontamination solutions. During alkaline, oxidative decontamination of nuclear power plant equipment a radioactive solution is produced. Owing to the storing difficulties of radioactive solutions it is necessary to develop a method for the in situ treatment of radioactive, alkaline, oxidative decontamination solutions, and for the concentration of radioactive components. Reactive adsorption seems to be promising for this purpose. 3 refs., 8 figs., 1 tab

  15. A digital instrument for reactivity measurements in a nuclear reactor

    International Nuclear Information System (INIS)

    Chwaszczewski, S.

    1979-01-01

    An instrument for digital determination of the reactivity in nuclear reactors is described. It is based on the CAMAC standard apparatus, suitable for the use of pulse or current type neutron detectors and operates with prompt response and an output signal proportional to the core neutron flux. The measured data of neutron flux and reactivity can be registered by a digital display unit, an indicator, or, by request of the operator, a paper type punch. The algorithms used for reactivity calculation are considered and the results of numerical studies on those algorithms are discussed. The instrument has been used for determining the reactivity of the control elements in the fast-thermal assembly ANNA and in the research reactor MARIA. Some results of these measurements are given. (author)

  16. Digital instrument for reactivity measurements in a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Chwaszczewski, S [Institute of Nuclear Research, Warsaw (Poland)

    1979-07-01

    An instrument for digital determination of the reactivity in nuclear reactors is described. It is based on the CAMAC standard apparatus, suitable for the use of pulse or current type neutron detectors and operates with prompt response and an output signal proportional to the core neutron flux. The measured data of neutron flux and reactivity can be registered by a digital display unit, an indicator, or, by request of the operator, a paper type punch. The algorithms used for reactivity calculation are considered and the results of numerical studies on those algorithms are discussed. The instrument has been used for determining the reactivity of the control elements in the fast-thermal assembly ANNA and in the research reactor MARIA. Some results of these measurements are given.

  17. Reactivity calculation with reduction of the nuclear power fluctuations

    International Nuclear Information System (INIS)

    Suescun Diaz, Daniel; Senra Martinez, Aquilino

    2009-01-01

    A new formulation is presented in this paper for the calculation of reactivity, which is simpler than the formulation that uses the Laplace and Z transforms. A treatment is also made to reduce the intensity of the noise found in the nuclear power signal used in the calculation of reactivity. Two classes of different filters are used for that. This treatment is based on the fact that the reactivity can be written by using the compose Simpson's rule resulting in a sum of two convolution terms with response to the impulse that is characteristic of a linear system. The linear part is calculated by using the filter named finite impulse response filter (FIR). The non-linear part is calculated using the filter exponentially adjusted by the least squares method, which does not cause attenuation in the reactivity calculation.

  18. Reactivity calculation with reduction of the nuclear power fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Suescun Diaz, Daniel [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914 RJ (Brazil)], E-mail: dsuescun@hotmail.com; Senra Martinez, Aquilino [COPPE/UFRJ, Programa de Engenharia Nuclear, Caixa Postal 68509, CEP 21941-914 RJ (Brazil)

    2009-05-15

    A new formulation is presented in this paper for the calculation of reactivity, which is simpler than the formulation that uses the Laplace and Z transforms. A treatment is also made to reduce the intensity of the noise found in the nuclear power signal used in the calculation of reactivity. Two classes of different filters are used for that. This treatment is based on the fact that the reactivity can be written by using the compose Simpson's rule resulting in a sum of two convolution terms with response to the impulse that is characteristic of a linear system. The linear part is calculated by using the filter named finite impulse response filter (FIR). The non-linear part is calculated using the filter exponentially adjusted by the least squares method, which does not cause attenuation in the reactivity calculation.

  19. Radiation enhanced reactivation of nuclear replicating mammalian viruses

    International Nuclear Information System (INIS)

    Bockstahler, L.E.; Lytle, C.D.

    1977-01-01

    When CV-1 monkey kidney cells were UV-irradiated (0 to 18 J/m 2 ) or X-irradiated (0 to 10 krads) before infection with UV-irradiated simian adenovirus 7 (SA7) or simian virus 40 (SV40), increases in the infectivity of these nuclear replicating viruses as measured by plaque formation were observed. These radiation enhanced reactivations, UV enhanced reactivation (UVER) and X-ray enhanced reactivation (X-ray ER), occurred both when virus infection immediately followed irradiation of the cells (except for X-ray ER with SA7) and when virus infection was delayed until 3 to 5 days after cell irradiation. While there was little difference in the levels of reactivation of UV-irradiated SV40 between immediate and delayed infection, delayed infection resulted in higher levels of reactivation of SA7. X-ray enhanced reactivation of UV-irradiated Herpes simplex virus persisted for several days but did not increase. Thus, X-ray enhanced and UV enhanced reactivations of these mammalian viruses were relatively long-lived effects. Essentially no UVER or X-ray ER was found in CV-1 cells for either immediate or delayed infection with UV-irradiated vaccinia virus or poliovirus, both of which replicate in the cell cytoplasm. These results suggest UVER and X-ray ER in mammalian cells may be restricted to viruses which are replicated in the cell nucleus. (author)

  20. Relations among several nuclear and electronic density functional reactivity indexes

    Science.gov (United States)

    Torrent-Sucarrat, Miquel; Luis, Josep M.; Duran, Miquel; Toro-Labbé, Alejandro; Solà, Miquel

    2003-11-01

    An expansion of the energy functional in terms of the total number of electrons and the normal coordinates within the canonical ensemble is presented. A comparison of this expansion with the expansion of the energy in terms of the total number of electrons and the external potential leads to new relations among common density functional reactivity descriptors. The formulas obtained provide explicit links between important quantities related to the chemical reactivity of a system. In particular, the relation between the nuclear and the electronic Fukui functions is recovered. The connection between the derivatives of the electronic energy and the nuclear repulsion energy with respect to the external potential offers a proof for the "Quantum Chemical le Chatelier Principle." Finally, the nuclear linear response function is defined and the relation of this function with the electronic linear response function is given.

  1. Nuclear data for the calculation of thermal reactor reactivity coefficients

    International Nuclear Information System (INIS)

    1989-01-01

    On its 15th meeting in Vienna, 16-20 June 1986, the International Nuclear Data Committee (INDC) considered it important to review the accuracy with which changes in thermal reactor reactivity resulting from changes in temperature and coolant density can be predicted. It was noted that reactor physicists in several countries had to adjust the thermal neutron cross-section data base in order to reproduce measured reactivity coefficients. Consequently, it appeared to be essential to examine the consistency of the integral and differential cross-section data and to make all the information available which has a bearing on reactivity coefficient prediction. Following the recommendation of the INDC, the Nuclear Data Section of the International Atomic Energy Agency, therefore, convened the Advisory Group Meeting on Nuclear Data for the Calculation of Thermal Reaction Reactivity Coefficients, in Vienna, Austria, 7-10 Dec. 1987. The Conclusions and Recommendations of the meeting together with the papers presented, are submitted in the present document. A separate abstract was prepared for each of these 12 papers. Refs, figs and tabs

  2. Study of reactivity of fluidized bed nuclear reactor

    International Nuclear Information System (INIS)

    Rammsy, J.E.M.

    1985-01-01

    The reactor physics calculations of a 19 module Fluidized Bed Nuclear Reactor using Leopard and Odog codes are performed. The behaviour of the reactor was studied by calculating the reactivity of the reactor as a function of the parameters governing the operational and accidental conditions of the reactor. The effects of temperature, pressure, and vapor generation in the core on the reactivity are calculated. Also the start up behaviour of the reactor is analyzed. For the purpose of the study of a prototype research reactor, the calculations on a one module reactor have been performed. (Author) [pt

  3. AIREKMOD-RR, Reactivity Transients in Nuclear Research Reactors

    International Nuclear Information System (INIS)

    Baggoura, B.; Mazrou, H.

    2001-01-01

    1 - Description of program or function: AIREMOD-RR is a point kinetics code which can simulate fast transients in nuclear research reactor cores. It can also be used for theoretical reactor dynamics studies. It is used for research reactor kinetic analysis and provides a point neutron kinetic capability. The thermal hydraulic behavior is governed by a one-dimensional heat balance equation. The calculations are restricted to a single equivalent unit cell which consists of fuel, clad and coolant. 2 - Method of solution: For transient reactor kinetic calculations a modified Runge Kutta numerical method is used. The external reactivity insertion, specified as a function of time, is converted in dollar ($) unit. The neutron density, energy release and feedback variables are given at each time step. The two types of reactivity feedback considered are: Doppler effect and moderator effect. A new expression for the reactivity dependence on the feedback variables has been introduced in the present version of the code. The feedback reactivities are fitted in power series expression. 3 - Restrictions on the complexity of the problem: The number of delayed neutron groups and the total number of equations are limited only by computer storage capabilities. - Coolant is always in liquid phase. - Void reactivity feedback is not considered

  4. Crystallization of hepatocyte nuclear factor 4α (HNF4α) in complex with the HNF1α promoter element

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Peng; Liu, Jianguo; Melikishvili, Manana; Fried, Michael G.; Chi, Young-In, E-mail: ychi@uky.edu [Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536 (United States)

    2008-04-01

    Sample preparation, characterization, crystallization and preliminary X-ray analysis are reported for the HNF4α–DNA binary complex. Hepatocyte nuclear factor 4α (HNF4α) is a member of the nuclear receptor superfamily that plays a central role in organ development and metabolic functions. Mutations on HNF4α cause maturity-onset diabetes of the young (MODY), a dominant monogenic cause of diabetes. In order to understand the molecular mechanism of promoter recognition and the molecular basis of disease-causing mutations, the recombinant HNF4α DNA-binding domain was prepared and used in a study of its binding properties and in crystallization with a 21-mer DNA fragment that contains the promoter element of another MODY gene, HNF1α. The HNF4α protein displays a cooperative and specific DNA-binding activity towards its target gene-recognition elements. Crystals of the complex diffract to 2.0 Å using a synchrotron-radiation source under cryogenic (100 K) conditions and belong to space group C2, with unit-cell parameters a = 121.63, b = 35.43, c = 70.99 Å, β = 119.36°. A molecular-replacement solution has been obtained and structure refinement is in progress. This structure and the binding studies will provide the groundwork for detailed functional and biochemical studies of the MODY mutants.

  5. Crystallization of hepatocyte nuclear factor 4α (HNF4α) in complex with the HNF1α promoter element

    International Nuclear Information System (INIS)

    Lu, Peng; Liu, Jianguo; Melikishvili, Manana; Fried, Michael G.; Chi, Young-In

    2008-01-01

    Sample preparation, characterization, crystallization and preliminary X-ray analysis are reported for the HNF4α–DNA binary complex. Hepatocyte nuclear factor 4α (HNF4α) is a member of the nuclear receptor superfamily that plays a central role in organ development and metabolic functions. Mutations on HNF4α cause maturity-onset diabetes of the young (MODY), a dominant monogenic cause of diabetes. In order to understand the molecular mechanism of promoter recognition and the molecular basis of disease-causing mutations, the recombinant HNF4α DNA-binding domain was prepared and used in a study of its binding properties and in crystallization with a 21-mer DNA fragment that contains the promoter element of another MODY gene, HNF1α. The HNF4α protein displays a cooperative and specific DNA-binding activity towards its target gene-recognition elements. Crystals of the complex diffract to 2.0 Å using a synchrotron-radiation source under cryogenic (100 K) conditions and belong to space group C2, with unit-cell parameters a = 121.63, b = 35.43, c = 70.99 Å, β = 119.36°. A molecular-replacement solution has been obtained and structure refinement is in progress. This structure and the binding studies will provide the groundwork for detailed functional and biochemical studies of the MODY mutants

  6. Thioesterase activity and acyl-CoA/fatty acid cross-talk of hepatocyte nuclear factor-4{alpha}.

    Science.gov (United States)

    Hertz, Rachel; Kalderon, Bella; Byk, Tamara; Berman, Ina; Za'tara, Ghadeer; Mayer, Raphael; Bar-Tana, Jacob

    2005-07-01

    Hepatocyte nuclear factor-4alpha (HNF-4alpha) activity is modulated by natural and xenobiotic fatty acid and fatty acyl-CoA ligands as a function of their chain length, unsaturation, and substitutions. The acyl-CoA site of HNF-4alpha is reported here to consist of the E-F domain, to bind long-chain acyl-CoAs but not the respective free acids, and to catalyze the hydrolysis of bound fatty acyl-CoAs. The free acid pocket, previously reported in the x-ray structure of HNF-4alpha E-domain, entraps fatty acids but excludes acyl-CoAs. The acyl-CoA and free acid sites are distinctive and noncongruent. Free fatty acid products of HNF-4alpha thioesterase may exchange with free acids entrapped in the fatty acid pocket of HNF-4alpha. Cross-talk between the acyl-CoA and free fatty acid binding sites is abrogated by high affinity, nonhydrolyzable acyl-CoA ligands of HNF-4alpha that inhibit its thioesterase activity. Hence, HNF-4alpha transcriptional activity is controlled by its two interrelated acyl ligands and two binding sites interphased in tandem by the thioesterase activity. The acyl-CoA/free-acid and receptor/enzyme duality of HNF-4alpha extends the paradigm of nuclear receptors.

  7. Identification of fast power reactivity effect in nuclear power reactor

    International Nuclear Information System (INIS)

    Efanov, A.I.; Kaminskas, V.A.; Lavrukhin, V.S.; Rimidis, A.P.; Yanitskene, D.Yu.

    1987-01-01

    A nuclear power reactor is an object of control with distributed parameters, characteristics of which vary during operation time. At the same time the reactor as the object of control has internal feedback circuits, which are formed as a result of the effects of fuel parameters and a coolant (pressure, temperature, steam content) on the reactor breeding properties. The problem of internal feedback circuit identification in a nuclear power reactor is considered. Conditions for a point reactor identification are obtained and algorithms of parametric identification are constructed. Examples of identification of fast power reactivity effect for the RBMK-1000 reactor are given. Results of experimental testing have shown that the developed method of fast power reactivity effect identification permits according to the data of normal operation to construct adaptive models for the point nuclear reactor, designed for its behaviour prediction in stationary and transition operational conditions. Therefore, the models considered can be used for creating control systems of nuclear power reactor thermal capacity (of RBMK type reactor, in particular) which can be adapted to the change in the internal feedback circuit characteristics

  8. Diclofenac inhibits tumor necrosis factor-a-induced nuclear factor-kB activation causing synergic hepatocyte apoptosis

    NARCIS (Netherlands)

    Frederiksson, L; Herpers, B; Benedetti, G; Matadin, Q; Puigvert, J.C.; de Bont, H; Dragovic, S.; Vermeulen, N.P.E.; Commandeur, J.N.M.; Danen, E; de Graauw, M; van de Water, B.

    2011-01-01

    Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by

  9. Microcystin-LR induced reactive oxygen species mediate cytoskeletal disruption and apoptosis of hepatocytes in Cyprinus carpio L.

    Directory of Open Access Journals (Sweden)

    Jinlin Jiang

    Full Text Available Microcystins (MCs are a group of cyclic hepatotoxic peptides produced by cyanobacteria. Microcystin-LR (MC-LR contains Leucine (L and Arginine (R in the variable positions, and is one of the most common and potently toxic peptides. MC-LR can inhibit protein phosphatase type 1 and type 2A (PP1 and PP2A activities and induce excessive production of reactive oxygen species (ROS. The underlying mechanism of the inhibition of PP1 and PP2A has been extensively studied. The over-production of ROS is considered to be another main mechanism behind MC-LR toxicity; however, the detailed toxicological mechanism involved in over-production of ROS in carp (Cyprinus carpio L. remains largely unclear. In our present study, the hydroxyl radical (•OH was significantly induced in the liver of carp after a relatively short-term exposure to MC-LR. The elevated reactive oxygen species (ROS production may play an important role in the disruption of microtubule structure. Pre-injection of the antioxidant N-acetyl-cysteine (NAC provided significant protection to the cytoskeleton, however buthionine sulfoximine (BSO exacerbated cytoskeletal destruction. In addition, the elevated ROS formation induced the expression of apoptosis-related genes, including p38, JNKa, and bcl-2. A significant increase in apoptotic cells was observed at 12-48 hours. Our study further supports evidence that ROS are involved in MC-LR induced damage to liver cells in carp, and indicates the need for further study of the molecular mechanisms behind MC-LR toxicity.

  10. Microcystin-LR Induced Reactive Oxygen Species Mediate Cytoskeletal Disruption and Apoptosis of Hepatocytes in Cyprinus carpio L.

    Science.gov (United States)

    Jiang, Jinlin; Shan, Zhengjun; Xu, Weili; Wang, Xiaorong; Zhou, Junying; Kong, Deyang; Xu, Jing

    2013-01-01

    Microcystins (MCs) are a group of cyclic hepatotoxic peptides produced by cyanobacteria. Microcystin-LR (MC-LR) contains Leucine (L) and Arginine (R) in the variable positions, and is one of the most common and potently toxic peptides. MC-LR can inhibit protein phosphatase type 1 and type 2A (PP1 and PP2A) activities and induce excessive production of reactive oxygen species (ROS). The underlying mechanism of the inhibition of PP1 and PP2A has been extensively studied. The over-production of ROS is considered to be another main mechanism behind MC-LR toxicity; however, the detailed toxicological mechanism involved in over-production of ROS in carp (Cyprinus carpio L.) remains largely unclear. In our present study, the hydroxyl radical (•OH) was significantly induced in the liver of carp after a relatively short-term exposure to MC-LR. The elevated reactive oxygen species (ROS) production may play an important role in the disruption of microtubule structure. Pre-injection of the antioxidant N-acetyl-cysteine (NAC) provided significant protection to the cytoskeleton, however buthionine sulfoximine (BSO) exacerbated cytoskeletal destruction. In addition, the elevated ROS formation induced the expression of apoptosis-related genes, including p38, JNKa, and bcl-2. A significant increase in apoptotic cells was observed at 12 - 48 hours. Our study further supports evidence that ROS are involved in MC-LR induced damage to liver cells in carp, and indicates the need for further study of the molecular mechanisms behind MC-LR toxicity. PMID:24376844

  11. Induction of Mkp-1 and Nuclear Translocation of Nrf2 by Limonoids from Khaya grandifoliola C.DC Protect L-02 Hepatocytes against Acetaminophen-Induced Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Arnaud F. Kouam

    2017-09-01

    Full Text Available Drug-induced liver injury (DILI is a major clinical problem where natural compounds hold promise for its abrogation. Khaya grandifoliola (Meliaceae is used in Cameroonian traditional medicine for the treatment of liver related diseases and has been studied for its hepatoprotective properties. Till date, reports showing the hepatoprotective molecular mechanism of the plant are lacking. The aim of this study was therefore to identify compounds from the plant bearing hepatoprotective activity and the related molecular mechanism by assessing their effects against acetaminophen (APAP-induced hepatotoxicity in normal human liver L-02 cells line. The cells were exposed to APAP (10 mM or co-treated with phytochemical compounds (40 μM over a period of 36 h and, biochemical and molecular parameters assessed. Three known limonoids namely 17-epi-methyl-6-hydroxylangolensate, 7-deacetoxy-7-oxogedunin and deacetoxy-7R-hydroxygedunin were identified. The results of cells viability and membrane integrity, reactive oxygen species generation and lipid membrane peroxidation assays, cellular glutathione content determination as well as expression of cytochrome P450 2E1 demonstrated the protective action of the limonoids. Immunoblotting analysis revealed that limonoids inhibited APAP-induced c-Jun N-terminal Kinase phosphorylation (p-JNK, mitochondrial translocation of p-JNK and Bcl2-associated X Protein, and the release of Apoptosis-inducing Factor into the cytosol. Interestingly, limonoids increased the expression of Mitogen-activated Protein Kinase Phosphatase (Mkp-1, an endogenous inhibitor of JNK phosphorylation and, induced the nuclear translocation of Nuclear Factor Erythroid 2-related Factor-2 (Nrf2 and decreased the expression of Kelch-like ECH-associated Protein-1. The limonoids also reversed the APAP-induced decreased mRNA levels of Catalase, Superoxide Dismutase-1, Glutathione-S-Transferase and Methionine Adenosyltransferase-1A. The obtained results

  12. Mutation in the factor VII hepatocyte nuclear factor 4α-binding site contributes to factor VII deficiency.

    Science.gov (United States)

    Zheng, Xing-Wu; Kudaravalli, Rama; Russell, Theresa T; DiMichele, Donna M; Gibb, Constance; Russell, J Eric; Margaritis, Paris; Pollak, Eleanor S

    2011-10-01

    Severe coagulant factor VII (FVII) deficiency in postpubertal dizygotic twin males results from two point mutations in the FVII gene, a promoter region T→C transition at -60 and a His-to-Arg substitution at amino acid 348; both mutations prevent persistence of plasma functional FVII. This report documents longitudinal laboratory measurements from infancy to adulthood of FVII coagulant activity (FVII:C) in the twin FVII-deficient patients; it also details specific biochemical analyses of the -60 T→C mutation. The results revealed FVII:C levels of less than 1% in infancy that remain severely decreased through puberty and into adulthood. In-vitro analyses utilizing hepatocyte nuclear factor 4α (HNF4α) co-transfection and a chromatin immunoprecipitation assay indicate that the -60 T→C mutation severely diminishes functional interaction between the FVII promoter and transcription factor HNF4α. The importance of interaction between the FVII gene and HNF4α in normal FVII expression provides an in-vivo illustration of the regulated expression of an autosomal gene encoding a coagulation protein. The constancy of FVII:C and peripubertal patient symptomatology reported here illustrates androgen-independent expression in contrast to expression with an analogous mutation in the promoter region of the gene encoding coagulation FIX.

  13. Evaluation of reactivity shutdown margin for nuclear fuel reload optimization

    International Nuclear Information System (INIS)

    Wong, Hing-Ip; Maldonado, G.I.

    1995-01-01

    The FORMOSA-P code is a nuclear fuel management optimization package that combines simulated annealing (SA) and nodal generalized perturbation theory (GPT). Recent studies at Electricite de France (EdF-Clamart) have produced good results for power-peaking minimizations under multiple limiting control rod configurations. However, since the reactivity shutdown margin is not explicitly treated as an objective or constraint function, then any optimal loading patterns (LPs) are not guaranteed to yield an adequate shutdown margin (SDM). This study describes the implementation of the SDM calculation within a FORMOSA-P optimization. Maintaining all additional computational requirements to a minimum was a key consideration

  14. Evaluation of reactivity shutdown margin for nuclear fuel reload optimization

    International Nuclear Information System (INIS)

    Engrand, P.; Wong, H. I.; Maldonado, G.I.

    1996-01-01

    The FORMOSA-P code is a nuclear fuel management optimization package which combines simulated annealing (SA) and nodal generalized perturbation theory (GPT). Recent studies at Electricite de France have produced good results for power peaking minimizations under multiple limiting control rod configurations. However, since the reactivity shutdown margin is not explicitly treated as an objective or constraint function, then any optimal loading patterns (LPs) are not guaranteed to yield an adequate shutdown margin (SDM). This study describes the implementation of the SDM calculation within a FORMOSA-P optimization. Maintaining all additional computational requirements to a minimum was a key consideration. (authors). 4 refs., 2 figs

  15. Nuclear Fuel Behaviour during Reactivity Initiated Accidents. Workshop Proceedings

    International Nuclear Information System (INIS)

    2010-01-01

    A reactivity initiated accident (RIA) is a nuclear reactor accident that involves an unwanted increase in fission rate and reactor power. The power increase may damage the reactor core. The main objective of the workshop was to review the current status of the experimental and analytical studies of the fuel behavior during the RIA transients in PWR and BWR reactors and the acceptance criteria for RIA in use and under consideration. The workshop was organized in an opening session and 5 technical sessions: 1) Recent experimental results and experimental techniques used; 2) Modelling and Data Interpretation; 3) Code Assessment; 4) RIA Core Analysis and 5) Revision and application of safety criteria

  16. Probabilistic method for evaluating reactivity margin of nuclear reactors

    International Nuclear Information System (INIS)

    Kaneko, Yoshihiko

    1984-01-01

    A probabilistic method is proposed that will permit in the design stage to estimate quantitatively the likelihood with which any or all design criteria applicable to a nuclear reactor are actually satisfied after its construction. The method is trially applied to the core reactivity balance problem of the experimental Very High Temperature Reactor, and calculations are performed on the probability with which a design study core will, upon construction, satisfy design criteria concerning (a) one rod stuck and (b) startup margin. The method should prove useful in making engineering judgments before approving reactor core design. (author)

  17. Reactivity control of nuclear power reactors: new options

    International Nuclear Information System (INIS)

    Alcala, F.

    1984-01-01

    Some actual aspects (referring to economy, non-proliferation and environmental impact) of nuclear power reactors has been analyzed from the point of view of the reactivity control physics. Specially studied have been the physical mechanisms related with the spectral shift control method and their general positive effects on those aspects. The analysis carried out suggested the application of the above method of control to reactors with non-hydrogenous fuel cells, which are mainly characterized by their high moderator/fuel ratio. Finally three different types of such fuel cells are presented and some results about one of them (belonging to a PHWR controlled by graphite rods) are given. (author)

  18. Multiplicity of nuclear receptor activation by PFOA and PFOS in primary human and rodent hepatocytes

    International Nuclear Information System (INIS)

    Bjork, J.A.; Butenhoff, J.L.; Wallace, K.B.

    2011-01-01

    Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) are surface active fluorochemicals that, due to their exceptional stability to degradation, are persistent in the environment. Both PFOA and PFOS are eliminated slowly in humans, with geometric mean serum elimination half-lives estimated at 3.5 and 4.8 years, respectively. The biological activity of PFOA and PFOS in rodents is attributed primarily to transactivation of the nuclear receptor peroxisome proliferator activated receptor alpha (PPARA), which is an important regulator of lipid and carbohydrate metabolism. However, there are significant species-specific differences in the response to PFOA and PFOS exposure; non-rodent species, including humans, are refractory to several but not all of these effects. Many of the metabolic effects have been attributed to the activation of PPARA; however, recent studies using PPARα knockout mice demonstrate residual PPARA-independent effects, some of which may involve the activation of alternate nuclear receptors, including NR1I2 (PXR), NR1I3 (CAR), NR1H3 (LXRA), and NR1H4 (FXR). The objective of this investigation was to characterize the activation of multiple nuclear receptors and modulation of metabolic pathways associated with exposure to PFOA and PFOS, and to compare and contrast the effects between rat and human primary liver cells using quantitative reverse transcription PCR (RT-qPCR). Our results demonstrate that multiple nuclear receptors participate in the metabolic response to PFOA and PFOS exposure resulting in a substantial shift from carbohydrate metabolism to fatty acid oxidation and hepatic triglyceride accumulation in rat liver cells. This shift in intermediary metabolism was more pronounced for PFOA than PFOS. Furthermore, while there is some similarity in the activation of metabolic pathways between rat and humans, particularly in PPARA regulated responses; the changes in primary human cells were more subtle and possibly reflect an adaptive

  19. Hepatocyte nuclear factor 4 alpha is a key factor related to depression and physiological homeostasis in the mouse brain.

    Directory of Open Access Journals (Sweden)

    Kyosuke Yamanishi

    Full Text Available Major depressive disorder (MDD is a common psychiatric disorder that involves marked disabilities in global functioning, anorexia, and severe medical comorbidities. MDD is associated with not only psychological and sociocultural problems, but also pervasive physical dysfunctions such as metabolic, neurobiological and immunological abnormalities. Nevertheless, the mechanisms underlying the interactions between these factors have yet to be determined in detail. The aim of the present study was to identify the molecular mechanisms responsible for the interactions between MDD and dysregulation of physiological homeostasis, including immunological function as well as lipid metabolism, coagulation, and hormonal activity in the brain. We generated depression-like behavior in mice using chronic mild stress (CMS as a model of depression. We compared the gene expression profiles in the prefrontal cortex (PFC of CMS and control mice using microarrays. We subsequently categorized genes using two web-based bioinformatics applications: Ingenuity Pathway Analysis and The Database for Annotation, Visualization, and Integrated Discovery. We then confirmed significant group-differences by analyzing mRNA and protein expression levels not only in the PFC, but also in the thalamus and hippocampus. These web tools revealed that hepatocyte nuclear factor 4 alpha (Hnf4a may exert direct effects on various genes specifically associated with amine synthesis, such as genes involved in serotonin metabolism and related immunological functions. Moreover, these genes may influence lipid metabolism, coagulation, and hormonal activity. We also confirmed the significant effects of Hnf4a on both mRNA and protein expression levels in the brain. These results suggest that Hnf4a may have a critical influence on physiological homeostasis under depressive states, and may be associated with the mechanisms responsible for the interactions between MDD and the dysregulation of

  20. Increased expression of hepatocyte nuclear factor 4 alpha transcribed by promoter 2 indicates a poor prognosis in hepatocellular carcinoma.

    Science.gov (United States)

    Cai, Shao-Hang; Lu, Shi-Xun; Liu, Li-Li; Zhang, Chris Zhiyi; Yun, Jing-Ping

    2017-10-01

    Hepatocyte nuclear factor 4 alpha (HNF4α) plays an important role in tumourigenesis. There is growing evidence indicating that HNF4α transcribed by promoter 1 (P1-HNF4α) is expressed at relatively low levels in HCC and its presence predicts a favourable outcome for hepatocellular carcinoma (HCC) patients. However, the role of HNF4α transcribed by promoter 2 (P2-HNF4α) in HCC remains unclear. A total of 615 HCC specimens were obtained to construct tissue microarrays and perform immunohistochemistry. The relationship between P2-HNF4α and clinical features of HCC patients were analysed. Kaplan-Meier analysis was conducted to assess the prognostic value of P2-HNF4α. The results showed that the expression of P2-HNF4α in HCC was noticeably increased in HCC tissues compared with the nontumourous tissues. In addition, P1-HNF4α expression was negatively correlated with P2-HNF4α expression ( p  = 0.023). High P2-HNF4α expression was significantly associated with poor differentiation of HCC ( p = 0.002) and vascular invasion ( p = 0.017). Kaplan-Meier analysis showed that P2-HNF4α expression was closely correlated with overall survival in the training group ( p = 0.01), validation group ( p = 0.034), and overall group of patients with HCC ( p P2-HNF4α, different from P1-HNF4α, is markedly upregulated and serves as an oncogene-associated protein in HCC. Our study therefore provides a promising biomarker for prognostic prediction and a potential therapeutic target for HCC.

  1. The Effects of Betaine on the Nuclear Fractal Dimension, Chromatin Texture, and Proliferative Activity in Hepatocytes in Mouse Model of Nonalcoholic Fatty Liver Disease.

    Science.gov (United States)

    Vesković, Milena; Labudović-Borović, Milica; Zaletel, Ivan; Rakočević, Jelena; Mladenović, Dušan; Jorgačević, Bojan; Vučević, Danijela; Radosavljević, Tatjana

    2018-04-01

    The effects of betaine on hepatocytes chromatin architecture changes were examined by using fractal and gray-level co-occurrence matrix (GLCM) analysis in methionine/choline-deficient (MCD) diet-induced, nonalcoholic fatty liver disease (NAFLD). Male C57BL/6 mice were divided into groups: (1) Control: standard diet; (2) BET: standard diet and betaine supplementation through drinking water (solution 1.5%); (3) MCD group: MCD diet for 6 weeks; (4) MCD+BET: fed with MCD diet + betaine for 6 weeks. Liver tissue was collected for histopathology, immunohistochemistry, and determination of fractal dimension and GLCM parameters. MCD diet induced diffuse micro- and macrovesicular steatosis accompanied with increased Ki67-positive hepatocyte nuclei. Steatosis and Ki67 immunopositivity were less prominent in the MCD+BET group compared with the MCD group. Angular second moment (ASM) and inverse difference moment (IDM) (textural homogeneity markers) were significantly increased in the MCD+BET group versus the MCD group (pMCD and the control group was evident. Heterogeneity parameters, contrast, and correlation were significantly increased in the MCD group versus the control (pMCD group (pMCD diet-induced NAFLD by reducing fat accumulation and inhibiting hepatocyte proliferation. Betaine supplementation increased nuclear homogeneity and chromatin complexity with reduction of entropy, contrast, and correlation.

  2. AB072. Novel mutation in the hepatocyte nuclear factor 1b/maturity-onset diabetes of the young type 5 gene—unreported Vietnamese case

    OpenAIRE

    Dung, Vu Chi; Thao, Bui Phuong; Ngoc, Can Thi Bich; Khanh, Nguyen Ngoc; Ellard, Sian

    2015-01-01

    Maturity-onset diabetes of the young type 5 (MODY5), a type of dominantly inherited diabetes mellitus and nephropathy, has been associated with mutations of the hepatocyte nuclear factor-1 (HNF-1β) gene, mostly generating truncated protein. Various phenotypes are related to HNF-1β mutations. Our aim to describe clinical and genetic findings in the unreported Vietnamese case identified with HNF-1β mutations. The proband with kidney failure from 7.5 years of age and diabetes diagnosed at 13.5 y...

  3. Development of an alternative reactivity meter for nuclear reactor control

    International Nuclear Information System (INIS)

    Ferreira, P.S.B.

    1991-01-01

    This work describes an alternative version of the IPEN-CNEN/SP reactivity-meter. This new version utilizes a programmable electrometer (to realize the data acquisition) and a IBM-PC microcomputer to process the reactivity calculation. The aim of development of this alternative reactivity-meter is to have available a equipment of measurements of reactivity in the case of the later version show any problem during an experiment. (author)

  4. Measurements and calculation of reactivity in the IEA-R1 nuclear reactor

    International Nuclear Information System (INIS)

    Ferreira, P.S.B.

    1988-01-01

    Techniques and experimentals procedures utilized in the measurement of some nuclear parameters related to reactivity are presented. Measurements of reactivity coefficients, such as void, temperature and power, and control rod worth were made in the IEA-R1 Research Reactor. The techniques used to perform the measurements were: i) stable period (control rod calibration), ii) inverse kinetics (digital reactivity meter), iii) aluminium slab insertion in the fuel element coolant channels (void reactivity), iv) nuclear reactor core temperature changes by means of the changes in the coolant systems of reactor core (isothermal reactivity coefficient) and v) by making perturbation in the core through the control rod motions (power reactivity coefficient and control rod calibration). By using the computer codes HAMMER, HAMMER-TECHNION and CITATION, the experiments realized in the IEA-R1 reactor were simulated. From this simulation, the theoretical reactivity parameters were estimated and compared with the respective experimental results. Furthermore, in the second fuel load of Angra-1 Nuclear Power Station, the IPEN-CNEN/SP digital reactivity - meter were used in the lower power test with the aim to assess the equipment performance. Among several tests, the reacticity-meter were used in parallel with a Westinghouse analogic reativimeter-meter) to measure the heat additiona point, critical boron concentration, control rod calibration, isothermal and moderator reactivity coefficient. These tests, and the results obtained by the digital reactivity-meter are described. The results were compared with those obtained by Westinghouse analogic reactivity meter, showing excellent agreement. (author) [pt

  5. Interaction of hepatocyte nuclear factors in transcriptional regulation of tissue specific hormonal expression of human multidrug resistance-associated protein 2 (abcc2)

    International Nuclear Information System (INIS)

    Qadri, Ishtiaq; Hu, L.-J.; Iwahashi, Mieko; Al-Zuabi, Subhi; Quattrochi, Linda C.; Simon, Francis R.

    2009-01-01

    Multidrug resistance-associated protein 2 (MRP2) (ABCC2) is an ATP-binding cassette membrane protein located primarily on apical surface of hepatocytes that mediates transport of conjugated xenobiotics and endogenous compounds into bile. MRP2 is highly expressed in hepatocytes, and at lower levels in small intestines, stomach and kidney. Previous reports have characterized mammalian MRP2 promoters, but none have established the molecular mechanism(s) involved in liver enriched expression. This study aims to investigate the mechanism of hepatic MRP2 regulation. A 2130 bp of MRP2 promoter was cloned from PAC-1 clone P108G1-7, to identify putative liver specific/hormone responsive functional DNA binding sites. Using deletion analysis, site specific mutagenesis and co-transfection studies, liver specific expression was determined. MRP2 promoter-LUC constructs were highly expressed in liver cell lines compared to non-liver cells. The region extending from - 3 to+ 458 bp of MRP2 promoter starting from AUG contained the potential binding sites for CAAATT box enhancer binding protein (C/EBP), hepatocytes nuclear factor 1, 3 and 4 (HNF1, HNF3, and HNF4. Only HNF1 and HNF4 co-transfection with MRP2 luciferase increased expression. Site specific mutational analysis of HNF1 binding site indicated an important role for HNF1α. HNF4α induction of MRP2 was independent of HNF1 binding site. C/EBP, HNF3, and HNF6 inhibited HNF1α while HNF4α induced MRP2 luciferase expression and glucocorticoids stimulated MRP2 expression. This study emphasizes the complex regulation of MRP2 with HNF1α and HNF4α playing a central role. The coordinated regulation of xenobiotic transporters and oxidative conjugation may determine the adaptive responses to cellular detoxification processes

  6. Measurement of xenon reactivity in the reactor of the nuclear ship 'MUTSU'

    International Nuclear Information System (INIS)

    Itagaki, Masafumi; Miyoshi, Yoshinori; Gakuhari, Kazuhiko; Okada, Noboru.

    1993-01-01

    This report deals with the measurement of reactivity changes caused by the increase and decrease of xenon concentration in the reactor core of the nuclear ship 'MUTSU' after a change from long-term operation at 70 % to zero power. The change in xenon reactivity was compensated by control-rod movements and the compensated reactivity was measured using a digital reactivity meter. The xenon override peak was recognized five and half hours after the start of power reduction. The equilibrium and peak reactivities of xenon were estimated by reading the initial and peak values of a theoretical curve which was fitted to the measured variation in xenon reactivity. The xenon reactivity results obtained by the present method can be considered to be accurate since no control-rod worth data were used and the measured quantity was the reactivity itself. (author)

  7. Modulation of nuclear T3 binding by T3 in a human hepatocyte cell-line (Chang-liver) - T3 stimulation of cell growth but not of malic enzyme, glucose-6-phosphatdehydrogenase or 6-phosphogluconate-dehydrogenase

    DEFF Research Database (Denmark)

    Matzen, L E; Kristensen, S R; Kvetny, J

    1991-01-01

    The T3 modulation of nuclear T3 binding (NBT3), the T3 effect on cell growth, and the T3 and insulin effects on malic enzyme (ME), glucose-6-phosphat-dehydrogenase (G6PD) and 6-phosphogluconat-dehydrogenase (G6PD) were studied in a human hepatocyte cell-line (Chang-liver). T3 was bound to a high ...

  8. Studies of the Ala/Val98 polymorphism of the hepatocyte nuclear factor-1alpha gene and the relationship to beta-cell function during an OGTT in glucose-tolerant women with and without previous gestational diabetes mellitus

    DEFF Research Database (Denmark)

    Lauenborg, J; Damm, P; Ek, J

    2004-01-01

    In pregnancies complicated by gestational diabetes mellitus (GDM) an increased demand for insulin is not met due to beta-cell dysfunction. An Ala/Val polymorphism at codon 98 of the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene has been associated with decreased serum insulin and C-peptide r...

  9. Chemical immobilization of fission products reactive with nuclear reactor components

    International Nuclear Information System (INIS)

    Grossman, L.N.; Kaznoff, A.I.; Clukey, H.V.

    1975-01-01

    This invention teaches a method of immobilizing deleterious fission products produced in nuclear fuel materials during nuclear fission chain reactions through the use of additives. The additives are disposed with the nuclear fuel materials in controlled quantities to form new compositions preventing attack of reactor components, especially nuclear fuel cld, by the deleterious fission products. (Patent Office Record)

  10. Reactivity Monitoring of Accelerator-Driven Nuclear Reactor Systems

    NARCIS (Netherlands)

    Uyttenhove, W.

    2016-01-01

    This thesis provides a methodology and set-up of a reactivity monitoring tool for Accelerator-Driven Systems (ADS). The reactivity monitoring tool should guarantee the operation of an ADS at a safe margin from criticality. Robustness is assured in different aspects of the monitoring tool: the choice

  11. The basic route of the nuclear translocation porcine growth hormone (GH)-growth hormone receptor (GHR) complex (pGH/GHR) in porcine hepatocytes.

    Science.gov (United States)

    Hainan, Lan; Huilin, Liu; Khan, Mahamad; Xin, Zheng; YuJiang, Yang; Hui, Zhang; Naiquan, Yao

    2018-06-08

    Traditional views suggest that growth hormone and the growth hormone receptor (GH/GHR complex) exert their functions only on the plasma membrane. This paradigm, however, has been challenged by recent new findings that the GH/GHR complex could translocate into cell nuclei where they could still exhibit important physiological functions. We also reported the nuclear localization of porcine GH/GHR and their potential functions in porcine hepatocytes. However, the basic path of pGH/GHR's nuclear translocation remains unclear. Combining previous research results and our current findings, we proposed two basic routes of pGH/GHR's nuclear transportation as follows: 1) after pGH binding to GHR, pGH/GHR enters into the cytoplasm though clathrin- or caveolin-mediated endocytosis, then the pGH/GHR complex enters into early endosomes (Rab5-positive), and the endosome carries the GH/GHR complex to the endoplasmic reticulum (ER). After endosome docking on the ER, the endosome starts fission, and the pGH/GHR complex enters into the ER lumen. Then the pGH/GHR complex transports into the cytoplasm, possibly by the ERAD pathway. Subsequently, the pGH/GHR complex interacts with IMPα/β, which, in turn, mediates GH/GHR nuclear localization; 2) pGH binds with the GHR on the cell membrane and, subsequently, pGH/GHR internalizes into the cell and enters into the endosome (this endosome may belong to a class of endosomes called envelope-associated endosomes (NAE)). Then, the endosome carries the pGH/GHR to the nuclear membrane. After docking on the nuclear membrane, the pGH/GHR complex fuses with the nuclear membrane and then enters into the cell nucleus. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Oxidative stress is involved in Dasatinib-induced apoptosis in rat primary hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Tao; Luo, Peihua; Zhu, Hong; Zhao, Yuqin [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Wu, Honghai; Gai, Renhua; Wu, Youping [Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); Yang, Bo [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaochun, E-mail: yangxiaochun@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); He, Qiaojun, E-mail: qiaojunhe@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China)

    2012-06-15

    Dasatinib, a multitargeted inhibitor of BCR–ABL and SRC kinases, exhibits antitumor activity and extends the survival of patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL). However, some patients suffer from hepatotoxicity, which occurs through an unknown mechanism. In the present study, we found that Dasatinib could induce hepatotoxicity both in vitro and in vivo. Dasatinib reduced the cell viability of rat primary hepatocytes, induced the release of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in vitro, and triggered the ballooning degeneration of hepatocytes in Sprague–Dawley rats in vivo. Apoptotic markers (chromatin condensation, cleaved caspase-3 and cleaved PARP) were detected to indicate that the injury induced by Dasatinib in hepatocytes in vitro was mediated by apoptosis. This result was further validated in vivo using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays. Here we found that Dasatinib dramatically increased the level of reactive oxygen species (ROS) in hepatocytes, reduced the intracellular glutathione (GSH) content, attenuated the activity of superoxide dismutase (SOD), generated malondialdehyde (MDA), a product of lipid peroxidation, decreased the mitochondrial membrane potential, and activated nuclear factor erythroid 2-related factor 2 (Nrf2) and mitogen-activated protein kinases (MAPK) related to oxidative stress and survival. These results confirm that oxidative stress plays a pivotal role in Dasatinib-mediated hepatotoxicity. N-acetylcysteine (NAC), a typical antioxidant, can scavenge free radicals, attenuate oxidative stress, and protect hepatocytes against Dasatinib-induced injury. Thus, relieving oxidative stress is a viable strategy for reducing Dasatinib-induced hepatotoxicity. -- Highlights: ►Dasatinib shows potential hepatotoxicity both in vitro and in vivo. ►Apoptosis plays a vital role in Dasatinib

  13. Simulation and study on reactivity disturbs dynamic character of HTR-10 nuclear power system

    International Nuclear Information System (INIS)

    Huang Xiaojin; Feng Yuankun

    2002-01-01

    In order to not only know 10 MW High Temperature Gas Cooled Reactor (HTR-10) nuclear power system's dynamic character more deeply but also to satisfy requirements of control system's design and analysis, the dynamic model of HTR-10 nuclear power system is established on the basis of dynamic model of HTR-10 nuclear system, which supplies turbine and generate electricity system model. Using this model, system's main variables' dynamic processes are simulated when control rod takes step reactivity disturb. The concussive progresses which is caused by reactivity disturb are analyzed. The results indicate that fuel temperature changing more slowly than nuclear power makes reactivity negative feedback not to restrain power changing, and then power concussive progress comes to being

  14. Mutations in the coding regions of the hepatocyte nuclear factor 4 alpha in Iranian families with maturity onset diabetes of the young

    Directory of Open Access Journals (Sweden)

    Tavakolafshari Jalil

    2009-12-01

    Full Text Available Abstract Hepatocyte nuclear factor 4α (HNF4α is a nuclear receptor involved in glucose homeostasis and is required for normal β cell function. Mutations in the HNF4α gene are associated with maturity onset diabetes of the young type 1 (MODY1. The aim of the present study was to determine the prevalence and nature of mutations in HNF4α gene in Iranian patients with a clinical diagnosis of MODY and their family members. Twelve families including 30 patients with clinically MODY diagnosis and 21 members of their family were examined using PCR-RFLP method and in case of mutation confirmed by sequencing techniques. Fifty age and sex matched subjects with normal fasting blood sugar (FBS and Glucose tolerance test (GTT were constituted the control group and investigated in the similar pattern. Single mutation of V255M in the HNF4α gene was detected. This known mutation was found in 8 of 30 patients and 3 of 21 individuals in relatives. Fifty healthy control subjects did not show any mutation. Here, it is indicated that the prevalence of HNF4α mutation among Iranian patients with clinical MODY is considerable. This mutation was present in 26.6% of our patients, but nothing was found in control group. In the family members, 3 subjects with the age of ≤25 years old carried this mutation. Therefore, holding this mutation in this range of age could be a predisposing factor for developing diabetes in future.

  15. Subcritical reactivity measurement at Angra 1 nuclear power plant

    International Nuclear Information System (INIS)

    Kuramoto, Renato Yoichi Ribeiro; Miranda, Anselmo Ferreira

    2011-01-01

    In order to speed up the Angra 1 NPP physics tests, this work intends to develop a digital reactivity meter combined with a methodology of the modified Neutron Source Multiplication (NSM) method with correction factors for subcriticality measurements at Angra 1 NPP. In the first part of this work, we have applied the Modified Neutron Source Multiplication (MNSM) Method with fundamental mode extraction, in order to improve the monitoring of the subcriticality at Angra 1 NPP during the criticality approach. In the second part, we developed a preliminary subcritical reactivity meter algorithm based on the point-reactor inverse kinetic model with six delayed neutron groups and external neutron source. The source strength was obtained through the Least Squares Inverse Kinetics Method (LSIKM). (author)

  16. A prevalent amino acid polymorphism at codon 98 (Ala98Val) of the hepatocyte nuclear factor-1alpha is associated with maturity-onset diabetes of the young and younger age at onset of type 2 diabetes in Asian Indians

    DEFF Research Database (Denmark)

    Anuradha, Shekher; Radha, Venkatesan; Deepa, Raj

    2005-01-01

    Among Europeans, mutations in the hepatocyte nuclear factor-1alpha (HNF1alpha) gene are associated with the most common form of maturity-onset diabetes of the young (MODY)3. In Asian Indians, type 2 diabetes occurs earlier and often overlaps with MODY, but the genetics of the latter are unknown....... The aim of this study was to estimate the prevalence of Ala98Val polymorphism of the HNF1alpha gene in different types of diabetes in Asian Indians....

  17. Calculation methods of reactivity using derivatives of nuclear power and Filter fir

    International Nuclear Information System (INIS)

    Diaz, Daniel Suescun

    2007-01-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  18. Nuclear data propagation with burnup. Impact on SFR reactivity coefficients

    International Nuclear Information System (INIS)

    Buiron, Laurent; Plisson-Rieunier, Daniele

    2017-01-01

    For the next generation fast reactor design, the Generation IV International Forum (GIF) defined global objectives in terms of safety improvement, sustainability, waste minimization and non-proliferation. Among the possibilities studied at CEA, Sodium cooled Fast Reactor (SFR) are studied as potential industrial tools for next decade's deployment. Many efforts have been made in the last years to obtain advanced industrial core designs that comply with these goals. Concerning safety issues, particular efforts have been made in order to obtain core designs that can be resilient to accidental transients. The 'safety' level of such new designs is often characterized by their 'natural' behavior under unprotected transients such as loss of flow or hypothetical transient over power. Transient analysis needs several accurate neutronic input data such as reactivity coefficient and kinetic parameters. Beside estimation of the level of 'absolute' values, associated uncertainties have also to be evaluated for the whole set of relevant data. These estimations have to be performed for different core state such as end of cycle core for feedback coefficient. This means that uncertainties have to be obtained not only a fixed time but also have to be propagated all through irradiation. To do so, we need to couple Boltzman and Bateman equations at sensitivities level. The coupling process could be done with the help of the perturbation theory which gives adapted framework suited for deterministic calculation codes. This coupling is currently in progress in ERANOS code system. The actual implementation gives access to estimation of sensitivities for both reactivity coefficients and mass balance. After a brief theoretical description of Boltzman/Bateman coupling capabilities in ERANOS, the study presented in this paper focuses on sensitivity and uncertainties estimation for the main feedback coefficients involved in fast reactor transients: the

  19. Calculation of reactivity for safety in nuclear reactors; Calculo de la reactividad para seguridad en reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Suescun D, D. [Universidad Surcolombiana, Av. Pastrana Borrero - Carrera 1, Neiva, Huila (Colombia); Rojas A, O., E-mail: daniel.suescun@usco.edu.co [Universidad Popular Autonoma del Estado de Puebla, Av. 9 Pte 1908, Barrio de Santiago, 72410 Puebla (Mexico)

    2017-09-15

    The measurement of reactivity is a function of time and its calculation results from the variation in nuclear power from the inverse equation of punctual kinetics. This equation is a differential integral, where the term of the integral conserves the historical power and the differential part is directly related to the period of the reactor. In practice, in a nuclear plant, sensors are required to record the signals. For example, the movements of the control rods that cause the fluctuations of nuclear power over time commonly generate signals with noise, an event that makes difficult to estimate the reactivity. Thus is necessary and very useful to build digital reactivity meters in real time, since allows a reactor to be operated with greater security. The calculation of the reactivity is carried out using punctual kinetics, especially the concentration of delayed neutron precursors. In this work we present a new way to reduce the fluctuations in the calculation of the reactivity, for the high precision we propose the generalization of the predictor and corrector of the Adams-Bashforth-Moulton (ABM) method of order 4 to solve numerically the equations of the point kinetics for the calculation of the reactivity, without using the power history, due to the nature of the equations of the punctual kinetics, the modifiers of the different predictors are used to increase the accuracy in the approximation obtained accompanied by the filter known as Savitzky-Golay (Sg), allow to reduce the fluctuations of reactivity. It is known that the Sg filter softens and does not attenuate the nuclear power regardless of its shape, guarantees to reduce noise levels up to σ = 0.01, with a calculation time step of σ = 0.01, s. This formulation uses a polynomial approximation of Gram, with a degree d = 2, to calculate the convolution coefficients by means of an analytical formula that is implemented computationally and avoids problems of bad conditioning, caused by the inversion of a

  20. Nuclear Nox4-Derived Reactive Oxygen Species in Myelodysplastic Syndromes

    Directory of Open Access Journals (Sweden)

    Marianna Guida

    2014-01-01

    Full Text Available A role for intracellular ROS production has been recently implicated in the pathogenesis and progression of a wide variety of neoplasias. ROS sources, such as NAD(PH oxidase (Nox complexes, are frequently activated in AML (acute myeloid leukemia blasts and strongly contribute to their proliferation, survival, and drug resistance. Myelodysplastic syndromes (MDS comprise a heterogeneous group of disorders characterized by ineffective hematopoiesis, with an increased propensity to develop AML. The molecular basis for MDS progression is unknown, but a key element in MDS disease progression is the genomic instability. NADPH oxidases are now recognized to have specific subcellular localizations, this targeting to specific compartments for localized ROS production. Local Nox-dependent ROS production in the nucleus may contribute to the regulation of redox-dependent cell growth, differentiation, senescence, DNA damage, and apoptosis. We observed that Nox1, 2, and 4 isoforms and p22phox and Rac1 subunits are expressed in MDS/AML cell lines and MDS samples, also in the nuclear fractions. Interestingly, Nox4 interacts with ERK and Akt1 within nuclear speckle domain, suggesting that Nox4 could be involved in regulating gene expression and splicing factor activity. These data contribute to the elucidation of the molecular mechanisms used by nuclear ROS to drive MDS evolution to AML.

  1. Functional defect of truncated hepatocyte nuclear factor-1{alpha} (G554fsX556) associated with maturity-onset diabetes of the young

    Energy Technology Data Exchange (ETDEWEB)

    Kooptiwut, Suwattanee, E-mail: S_kooptiwut@hotmail.com [Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Sujjitjoon, Jatuporn [Department of Immunology and Immunology Graduate Program, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Plengvidhya, Nattachet [Department of Immunology and Immunology Graduate Program, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Boonyasrisawat, Watip; Chongjaroen, Nalinee; Jungtrakoon, Prapapron [Department of Immunology and Immunology Graduate Program, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Semprasert, Namoiy [Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Furuta, Hiroto; Nanjo, Kishio [The First Department, Wakayama Medical University (Japan); Banchuin, Napatawn [Department of Immunology and Immunology Graduate Program, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Yenchitsomanus, Pa-thai [Division of Medical Molecular Biology, Medicine Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700 (Thailand); Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Bangkok (Thailand)

    2009-05-22

    A novel frameshift mutation attributable to 14-nucleotide insertion in hepatocyte nuclear factor-1{alpha} (HNF-1{alpha}) encoding a truncated HNF-1{alpha} (G554fsX556) with 76-amino acid deletion at its carboxyl terminus was identified in a Thai family with maturity-onset diabetes of the young (MODY). The wild-type and mutant HNF-1{alpha} proteins were expressed by in vitro transcription and translation (TNT) assay and by transfection in HeLa cells. The wild-type and mutant HNF-1{alpha} could similarly bind to human glucose-transporter 2 (GLUT2) promoter examined by electrophoretic mobility shift assay (EMSA). However, the transactivation activities of mutant HNF-1{alpha} on human GLUT2 and rat L-type pyruvate kinase (L-PK) promoters in HeLa cells determined by luciferase reporter assay were reduced to approximately 55-60% of the wild-type protein. These results suggested that the functional defect of novel truncated HNF-1{alpha} (G554fsX556) on the transactivation of its target-gene promoters would account for the {beta}-cell dysfunction associated with the pathogenesis of MODY.

  2. Functional defect of truncated hepatocyte nuclear factor-1α (G554fsX556) associated with maturity-onset diabetes of the young

    International Nuclear Information System (INIS)

    Kooptiwut, Suwattanee; Sujjitjoon, Jatuporn; Plengvidhya, Nattachet; Boonyasrisawat, Watip; Chongjaroen, Nalinee; Jungtrakoon, Prapapron; Semprasert, Namoiy; Furuta, Hiroto; Nanjo, Kishio; Banchuin, Napatawn; Yenchitsomanus, Pa-thai

    2009-01-01

    A novel frameshift mutation attributable to 14-nucleotide insertion in hepatocyte nuclear factor-1α (HNF-1α) encoding a truncated HNF-1α (G554fsX556) with 76-amino acid deletion at its carboxyl terminus was identified in a Thai family with maturity-onset diabetes of the young (MODY). The wild-type and mutant HNF-1α proteins were expressed by in vitro transcription and translation (TNT) assay and by transfection in HeLa cells. The wild-type and mutant HNF-1α could similarly bind to human glucose-transporter 2 (GLUT2) promoter examined by electrophoretic mobility shift assay (EMSA). However, the transactivation activities of mutant HNF-1α on human GLUT2 and rat L-type pyruvate kinase (L-PK) promoters in HeLa cells determined by luciferase reporter assay were reduced to approximately 55-60% of the wild-type protein. These results suggested that the functional defect of novel truncated HNF-1α (G554fsX556) on the transactivation of its target-gene promoters would account for the β-cell dysfunction associated with the pathogenesis of MODY.

  3. Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Mayra Domínguez-Pérez

    2016-01-01

    Full Text Available Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system.

  4. Impact of correlations between core configurations for the evaluation of nuclear data uncertainty propagation for reactivity

    International Nuclear Information System (INIS)

    Frosio, T.; Bonaccorsi, T.; Blaise, P.

    2017-01-01

    The precise estimation of Pearson correlations, also called 'representativity' coefficients, between core configurations is a fundamental quantity for properly assessing the nuclear data (ND) uncertainties propagation on integral parameters such as k-eff, power distributions, or reactivity coefficients. In this paper, a traditional adjoint method is used to propagate ND uncertainty on reactivity and reactivity coefficients and estimate correlations between different states of the core. We show that neglecting those correlations induces a loss of information in the final uncertainty. We also show that using approximate values of Pearson does not lead to an important error of the model. This calculation is made for reactivity at the beginning of life and can be extended to other parameters during depletion calculations. (authors)

  5. Calculation of nuclear reactivity using the generalised Adams-Bashforth-Moulton predictor corrector method

    Energy Technology Data Exchange (ETDEWEB)

    Suescun-Diaz, Daniel [Surcolombiana Univ., Neiva (Colombia). Groupo de Fisica Teorica; Narvaez-Paredes, Mauricio [Javeriana Univ., Cali (Colombia). Groupo de Matematica y Estadistica Aplicada Pontificia; Lozano-Parada, Jamie H. [Univ. del Valle, Cali (Colombia). Dept. de Ingenieria

    2016-03-15

    In this paper, the generalisation of the 4th-order Adams-Bashforth-Moulton predictor-corrector method is proposed to numerically solve the point kinetic equations of the nuclear reactivity calculations without using the nuclear power history. Due to the nature of the point kinetic equations, different predictor modifiers are used in order improve the precision of the approximations obtained. The results obtained with the prediction formulas and generalised corrections improve the precision when compared with previous methods and are valid for various forms of nuclear power and different time steps.

  6. Shutdown reactivity meter system for nuclear fuel storage cells

    International Nuclear Information System (INIS)

    Schultz, M.A.

    1981-01-01

    A system for determining whether a self-sustaining neutron chain reaction (I.E., criticality) may occur as each successive nuclear fuel element is added to a liquid-filled tank. This is accomplished by determining whether a multiplication factor, k, approaches unity after each element is added to the tank in accordance with the equation: cr ( Alpha s)/(1-k) where: S is the emission rate of the neutron source; alpha is a term that reflects the detector sensitivity as well as the attenuation of the neutron between source and detector and various geometric considerations in the tank; cr is the counting rate from a neutron detector; and K is a multiplication factor of the assembly at any given time for any given element configuration

  7. Selective insulin resistance in hepatocyte senescence

    International Nuclear Information System (INIS)

    Aravinthan, Aloysious; Challis, Benjamin; Shannon, Nicholas; Hoare, Matthew; Heaney, Judith; Alexander, Graeme J.M.

    2015-01-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance

  8. Selective insulin resistance in hepatocyte senescence

    Energy Technology Data Exchange (ETDEWEB)

    Aravinthan, Aloysious [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Challis, Benjamin [Institute of Metabolic Sciences, University of Cambridge, Cambridge (United Kingdom); Shannon, Nicholas [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Hoare, Matthew [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Heaney, Judith [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Foundation for Liver Research, Institute of Hepatology, London (United Kingdom); Alexander, Graeme J.M., E-mail: gja1000@doctors.org.uk [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom)

    2015-02-01

    Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

  9. Insertion of liver enriched transcription factor hepatocyte nuclear factor-4 (HNF-4) in a vector which contains simian virus (SV40) promoter

    International Nuclear Information System (INIS)

    Al-Nbaheen, M.; Pourzand, C.; Tyrrell, R.M.

    2006-01-01

    One way of targeting gene expression in vivo is to control transcription using a tissue-specific regulatory system. Tissue specific promoters or enhancers are in use in transgenic animals and could be utilized in medical for gene therapy. At present the usual method for selection of a tissue-specific promoter is to identify a gene, which is expressed at unusually high level in the target tissue, and then to use the promoter for this gene to drive expression of another therapeutic gene in the target tissue. This approach is logical but does not always lead to high levels of gene expression. A second approach is to investigate the scope for discovery of synthetic specific promoters using a target tissue. The objective of the work described in this paper was to use both approach to design plasmid DNA expression vectors that would carry liver-specific promoter/enhancer linked to reporter gene (i.e. luciferase). Then transfect these vectors to both liver-derived and non-liver cell lines. This is followed by evaluation of the liver-specificity of each construct by measuring the basal level expression of the reporter gene (i.e. luciferase activity) in both cell lines. Hepatocyte nuclear factor-4 (HNF-4) is liver-enriched transcription factor used to design new synthetic enhancers by inserting a tandem array of 1', 3' or 5' repeats of the HNF-4 binding site upstream of the SV40 promoter linked to the luciferase reporter gene within an Epstein-Barr virus (EBV)-based vector, p 706. The results of transfection revealed that unexpectedly the HNF-4 binding sites in these constructs act as a repressor rather than enhancer of the liver-specific expression of the luciferase gene. (author)

  10. Yes-associated protein/TEA domain family member and hepatocyte nuclear factor 4-alpha (HNF4α) repress reciprocally to regulate hepatocarcinogenesis in rats and mice.

    Science.gov (United States)

    Cai, Wang-Yu; Lin, Ling-Yun; Hao, Han; Zhang, Sai-Man; Ma, Fei; Hong, Xin-Xin; Zhang, Hui; Liu, Qing-Feng; Ye, Guo-Dong; Sun, Guang-Bin; Liu, Yun-Jia; Li, Sheng-Nan; Xie, Yuan-Yuan; Cai, Jian-Chun; Li, Bo-An

    2017-04-01

    Great progress has been achieved in the study of Hippo signaling in regulating tumorigenesis; however, the downstream molecular events that mediate this process have not been completely defined. Moreover, regulation of Hippo signaling during tumorigenesis in hepatocellular carcinoma (HCC) remains largely unknown. In the present study, we systematically investigated the relationship between Yes-associated protein/TEA domain family member (YAP-TEAD) and hepatocyte nuclear factor 4-alpha (HNF4α) in the hepatocarcinogenesis of HCC cells. Our results indicated that HNF4α expression was negatively regulated by YAP1 in HCC cells by a ubiquitin proteasome pathway. By contrast, HNF4α was found to directly associate with TEAD4 to compete with YAP1 for binding to TEAD4, thus inhibiting the transcriptional activity of YAP-TEAD and expression of their target genes. Moreover, overexpression of HNF4α was found to significantly compromise YAP-TEAD-induced HCC cell proliferation and stem cell expansion. Finally, we documented the regulatory mechanism between YAP-TEAD and HNF4α in rat and mouse tumor models, which confirmed our in vitro results. There is a double-negative feedback mechanism that controls TEAD-YAP and HNF4α expression in vitro and in vivo, thereby regulating cellular proliferation and differentiation. Given that YAP acts as a dominant oncogene in HCC and plays a crucial role in stem cell homeostasis and tissue regeneration, manipulating the interaction between YAP, TEADs, and HNF4α may provide a new approach for HCC treatment and regenerative medicine. (Hepatology 2017;65:1206-1221). © 2016 by the American Association for the Study of Liver Diseases.

  11. Studies of genetic variability of the hepatocyte nuclear factor-1α gene in an Indian maturity-onset diabetes of the young family.

    Science.gov (United States)

    Yang, Jing; Jiang, Feng; Guo, Hui; Soniya, Thadimacca; Yan, Chun-Xia; Tian, Zhu-Fang; Shi, Bing-Yin

    2016-01-01

    Maturity-onset diabetes of the young (MODY), one of the specific types of diabetes mellitus, is a monogenetic disorder characterized by an autosomal dominant (AD) inheritance and β-cell dysfunction. To study an Indian family with clinical diagnosis of MODY and detect the genetic mutations in the aspect of molecular mechanism, seven blood samples were obtained from the diabetic patients of this pedigree and genomic DNA was extracted from peripheral leukocytes. The exon1, exon2 and exon4 of hepatocyte nuclear factor-1α (HNF-1α) gene were amplified by polymerase chain reaction. Then the products were sequenced and compared with standard sequences on gene bank. As a result, two mutations were detected in exon1. That was CTC → CTG (Leu → Leu) in codon17 and ATC → CTC (Ile → Leu) in codon27. I27L was speculated to have a close relationship with the glycometabolism and the pathogenesis of diabetes mellitus together with the putative novel mutation existed in this Indian pedigree. Meanwhile, one mutation of GGG → GGC (Gly → Gly) in codon288 of exon4 was detected in the proband. No mutations were found in exon2 but a G → T base substitution in the intron4 region among all seven samples was detected. It may have some potential effects on the onset of diabetes in this family, but we do not have any evidence right now. Although it requires further investigation on the function of mutations found in the intron region, our research may provide some clue for this issue and it deserves more attention.

  12. Nuclear reactivity indices in the context of spin polarized density functional theory

    International Nuclear Information System (INIS)

    Cardenas, Carlos; Lamsabhi, Al Mokhtar; Fuentealba, Patricio

    2006-01-01

    In this work, the nuclear reactivity indices of density functional theory have been generalized to the spin polarized case and their relationship to electron spin polarized indices has been established. In particular, the spin polarized version of the nuclear Fukui function has been proposed and a finite difference approximation has been used to evaluate it. Applications to a series of triatomic molecules demonstrate the ability of the new functions to predict the geometrical changes due to a change in the spin multiplicity. The main equations in the different ensembles have also been presented

  13. Chemical Reactivity Testing for the National Spent Nuclear Fuel Program. Quality Assurance Project Plan

    International Nuclear Information System (INIS)

    Newsom, H.C.

    1999-01-01

    This quality assurance project plan (QAPjP) summarizes requirements used by Lockheed Martin Energy Systems, Incorporated (LMES) Development Division at Y-12 for conducting chemical reactivity testing of Department of Energy (DOE) owned spent nuclear fuel, sponsored by the National Spent Nuclear Fuel Program (NSNFP). The requirements are based on the NSNFP Statement of Work PRO-007 (Statement of Work for Laboratory Determination of Uranium Hydride Oxidation Reaction Kinetics.) This QAPjP will utilize the quality assurance program at Y-12, QA-101PD, revision 1, and existing implementing procedures for the most part in meeting the NSNFP Statement of Work PRO-007 requirements, exceptions will be noted

  14. Effect of 3-D moderator flow configurations on the reactivity of CANDU nuclear reactors

    International Nuclear Information System (INIS)

    Zadeh, Foad Mehdi; Etienne, Stephane; Chambon, Richard; Marleau, Guy; Teyssedou, Alberto

    2017-01-01

    Highlights: • 3-D CFD simulations of CANDU-6 moderator flows are presented. • A thermal-hydraulic code using thermal physical fluid properties is used. • The numerical approach and convergence is validated against available data. • Flow configurations are correlated using Richardson’s number. • The interaction between moderator temperatures with reactivity is determined. - Abstract: The reactivity of nuclear reactors can be affected by thermal conditions prevailing within the moderator. In CANDU reactors, the moderator and the coolant are mechanically separated but not necessarily thermally isolated. Hence, any variation of moderator flow properties may change the reactivity. Until now, nuclear reactor calculations have been performed by assuming uniform moderator flow temperature distribution. However, CFD simulations have predicted large time dependent flow fluctuations taking place inside the calandria, which can bring about local temperature variations that can exceed 50 °C. This paper presents robust CANDU 3-D CFD moderator simulations coupled to neutronic calculations. The proposed methodology makes it possible to study not only different moderator flow configurations but also their effects on the reactor reactivity coefficient.

  15. Reactivity worth measurements on the CALIBAN reactor: interpretation of integral experiments for the nuclear data validation

    International Nuclear Information System (INIS)

    Richard, B.

    2012-01-01

    The good knowledge of nuclear data, input parameters for the neutron transport calculation codes, is necessary to support the advances of the nuclear industry. The purpose of this work is to bring pertinent information regarding the nuclear data integral validation process. Reactivity worth measurements have been performed on the Caliban reactor, they concern four materials of interest for the nuclear industry: gold, lutetium, plutonium and uranium 238. Experiments which have been conducted in order to improve the characterization of the core are also described and discussed, the latter are necessary to the good interpretation of reactivity worth measurements. The experimental procedures are described with their associated uncertainties, measurements are then compared to numerical results. The methods used in numerical calculations are reported, especially the multigroup cross sections generation for deterministic codes. The modeling of the experiments is presented along with the associated uncertainties. This comparison led to an interpretation concerning the qualification of nuclear data libraries. Discrepancies are reported, discussed and justify the need of such experiments. (author) [fr

  16. A method for on-line reactivity monitoring in nuclear reactors

    International Nuclear Information System (INIS)

    Dulla, S.; Nervo, M.; Ravetto, P.

    2014-01-01

    Highlights: • The problem of the on-line monitoring of reactivity in a source-free nuclear reactor is considered. • A relationship between the system stable period and the power, its derivative and its integral is derived. • The reactivity can be reconstructed at each time instant from the measured power-related quantities. • A study on the sensitivity of the reactivity to the uncertainty on the values of the integral parameters is performed. • The spatial effects are investigated by applying the method to the interpretation of flux signals. - Abstract: In the present work the problem of the on-line monitoring of the reactivity in a source-free nuclear reactor is considered. The method is based on the classic point kinetic model of reactor physics. A relationship between the instantaneous value of the system stable period and the values of the neutron flux amplitude (or the power), of its derivative and of the integral convolution term determining the instantaneous value of the effective delayed neutron concentration is derived. The reactivity can then be evaluated through the application of the inhour equation, assuming the effective delayed neutron fraction and prompt generation time are known from independent measurements. Since the power related quantities can be assumed to be experimental observables at each instant, the reactivity can be easily reconstructed. The method is tested at first through the interpretation of power histories simulated by the solution of the point kinetic equations; the effect of the time interval between power detections on the accuracy is studied, proving the excellent performance of the procedure. The work includes also a study on the sensitivity of the reactivity forecast to the uncertainty on the values of the effective delayed neutron fraction and prompt generation time. The spatial effects are investigated by applying the method to the interpretation of flux evolution histories generated by a numerical code solving

  17. Nuclear Data Uncertainty Propagation to Reactivity Coefficients of a Sodium Fast Reactor

    Science.gov (United States)

    Herrero, J. J.; Ochoa, R.; Martínez, J. S.; Díez, C. J.; García-Herranz, N.; Cabellos, O.

    2014-04-01

    The assessment of the uncertainty levels on the design and safety parameters for the innovative European Sodium Fast Reactor (ESFR) is mandatory. Some of these relevant safety quantities are the Doppler and void reactivity coefficients, whose uncertainties are quantified. Besides, the nuclear reaction data where an improvement will certainly benefit the design accuracy are identified. This work has been performed with the SCALE 6.1 codes suite and its multigroups cross sections library based on ENDF/B-VII.0 evaluation.

  18. Diffuse glomerular nodular lesions in diabetic pigs carrying a dominant-negative mutant hepatocyte nuclear factor 1-alpha, an inheritant diabetic gene in humans.

    Directory of Open Access Journals (Sweden)

    Satoshi Hara

    Full Text Available Glomerular nodular lesions, known as Kimmelstiel-Wilson nodules, are a pathological hallmark of progressive human diabetic nephropathy. We have induced severe diabetes in pigs carrying a dominant-negative mutant hepatocyte nuclear factor 1-alpha (HNF1α P291fsinsC, a maturity-onset diabetes of the young type-3 (MODY3 gene in humans. In this model, glomerular pathology revealed that formation of diffuse glomerular nodules commenced as young as 1 month of age and increased in size and incidence until the age of 10 months, the end of the study period. Immunohistochemistry showed that the nodules consisted of various collagen types (I, III, IV, V and VI with advanced glycation end-product (AGE and Nε-carboxymethyl-lysine (CML deposition, similar to those in human diabetic nodules, except for collagen type I. Transforming growth factor-beta (TGF-β was also expressed exclusively in the nodules. The ultrastructure of the nodules comprised predominant interstitial-type collagen deposition arising from the mesangial matrices. Curiously, these nodules were found predominantly in the deep cortex. However, diabetic pigs failed to show any of the features characteristic of human diabetic nephropathy; e.g., proteinuria, glomerular basement membrane thickening, exudative lesions, mesangiolysis, tubular atrophy, interstitial fibrosis, and vascular hyalinosis. The pigs showed only Armanni-Ebstein lesions, a characteristic tubular manifestation in human diabetes. RT-PCR analysis showed that glomeruli in wild-type pigs did not express endogenous HNF1α and HNF1β, indicating that mutant HNF1α did not directly contribute to glomerular nodular formation in diabetic pigs. In conclusion, pigs harboring the dominant-negative mutant human MODY3 gene showed reproducible and distinct glomerular nodules, possibly due to AGE- and CML-based collagen accumulation. Although the pathology differed in several respects from that of human glomerular nodular lesions, the

  19. Role of the nuclear xenobiotic receptors CAR and PXR in induction of cytochromes P450 by non-dioxinlike polychlorinated biphenyls in cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Gährs, Maike; Roos, Robert; Andersson, Patrik L.; Schrenk, Dieter

    2013-01-01

    Polychlorinated biphenyls (PCBs) are among the most ubiquitously detectable ‘persistent organic pollutants’. In contrast to ‘dioxinlike’ (DL) PCBs, less is known about the molecular mode of action of the larger group of the ‘non-dioxinlike’ (NDL) PCBs. Owing to the life-long exposure of the human population, a carcinogenic, i.e., tumor-promoting potency of NDL-PCBs has to be considered in human risk assessment. A major problem in risk assessment of NDL-PCBs is dioxin-like impurities that can occur in commercially available NDL-PCB standards. In the present study, we analyzed the induction of CYP2B1 and CYP3A1 in primary rat hepatocytes using a number of highly purified NDL-PCBs with various degrees of chlorination and substitution patterns. Induction of these enzymes is mediated by the nuclear xenobiotic receptors CAR (Constitutive androstane receptor) and PXR (Pregnane X receptor). For CYP2B1 induction, concentration–response analysis revealed a very narrow window of EC 50 estimates, being in the range of 1–4 μM for PCBs 28 and 52, and between 0.4 and 1 μM for PCBs 101, 138, 153 and 180. CYP3A1 induction was less sensitive to NDL-PCBs, the most pronounced induction being achieved at 100 μM with the higher chlorinated congeners. Using okadaic acid and small interfering RNAs targeting CAR and PXR, we could demonstrate that CAR plays a major role and PXR a minor role in NDL-PCB-driven induction of CYPs, both effects showing no stringent structure–activity relationship. As the only obvious relevant determinant, the degree of chlorination was found to be positively correlated with the inducing potency of the congeners. - Highlights: • We analyzed six highly purified NDL-PCBs for CYP2B1 and CYP3A1 expression. • CAR plays a major, PXR a minor role in NDL-PCB-driven induction of CYPs. • The degree of chlorination seems to be the major parameter for the inducing potency. • There exists a competition between CAR and PXR. • Activated PXR may

  20. Role of the nuclear xenobiotic receptors CAR and PXR in induction of cytochromes P450 by non-dioxinlike polychlorinated biphenyls in cultured rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Gährs, Maike; Roos, Robert [University of Kaiserslautern, Food Chemistry and Toxicology, Erwin-Schroedinger-Str. 52, D-67663 Kaiserslautern (Germany); Andersson, Patrik L. [Umeå University, Department of Chemistry, Linnaeus väg 6, SE-901 87 Umeå (Sweden); Schrenk, Dieter, E-mail: schrenk@rhrk.uni-kl.de [University of Kaiserslautern, Food Chemistry and Toxicology, Erwin-Schroedinger-Str. 52, D-67663 Kaiserslautern (Germany)

    2013-10-01

    Polychlorinated biphenyls (PCBs) are among the most ubiquitously detectable ‘persistent organic pollutants’. In contrast to ‘dioxinlike’ (DL) PCBs, less is known about the molecular mode of action of the larger group of the ‘non-dioxinlike’ (NDL) PCBs. Owing to the life-long exposure of the human population, a carcinogenic, i.e., tumor-promoting potency of NDL-PCBs has to be considered in human risk assessment. A major problem in risk assessment of NDL-PCBs is dioxin-like impurities that can occur in commercially available NDL-PCB standards. In the present study, we analyzed the induction of CYP2B1 and CYP3A1 in primary rat hepatocytes using a number of highly purified NDL-PCBs with various degrees of chlorination and substitution patterns. Induction of these enzymes is mediated by the nuclear xenobiotic receptors CAR (Constitutive androstane receptor) and PXR (Pregnane X receptor). For CYP2B1 induction, concentration–response analysis revealed a very narrow window of EC{sub 50} estimates, being in the range of 1–4 μM for PCBs 28 and 52, and between 0.4 and 1 μM for PCBs 101, 138, 153 and 180. CYP3A1 induction was less sensitive to NDL-PCBs, the most pronounced induction being achieved at 100 μM with the higher chlorinated congeners. Using okadaic acid and small interfering RNAs targeting CAR and PXR, we could demonstrate that CAR plays a major role and PXR a minor role in NDL-PCB-driven induction of CYPs, both effects showing no stringent structure–activity relationship. As the only obvious relevant determinant, the degree of chlorination was found to be positively correlated with the inducing potency of the congeners. - Highlights: • We analyzed six highly purified NDL-PCBs for CYP2B1 and CYP3A1 expression. • CAR plays a major, PXR a minor role in NDL-PCB-driven induction of CYPs. • The degree of chlorination seems to be the major parameter for the inducing potency. • There exists a competition between CAR and PXR. • Activated PXR

  1. Reactivation of nuclear power plant construction projects. Plant status, policy issues and regulatory options

    International Nuclear Information System (INIS)

    Spangler, M.B.

    1986-07-01

    Prior to the TMI-2 accident on March 28, 1979, four nuclear power plant units that had previously been issued a construction permit were cancelled, principally because of reduced projections of regional power demand. Since that time, an additional 31 units with CPs have been cancelled and eight units deferred. On December 23, 1985 one of the deferred units (Limerick-2) was reactivated and construction resumed. The primary objective of this policy study is to identify the principal issues requiring office-level consideration in the event of reactivation of the construction of one or more of the nuclear power plants falling into two categories: (1) LWR units issued a construction permit whose construction has been cancelled, and (2) LWR units whose construction has been deferred. The study scope is limited to identifying regulatory issues or questions deserving analysis rather than providing, at this time, answers or recommended actions. Five tasks are addressed: a tabulation and discussion of the status of all cancelled and deferred LWR units; and identification of potential safety and environmental issues; an identification of regulatory or policy issues and needed information to determine the desirability of revising certain rules and policies; and identification of regulatory options and decision criteria; and an identification of decision considerations in determining staff requirements and organizational coordination of LWR reactivation policy and implementation efforts. 41 refs

  2. Neutron and thermo - hydraulic model of a reactivity transient in a nuclear power plant fuel element

    International Nuclear Information System (INIS)

    Oliva, Jose de Jesus Rivero

    2012-01-01

    A reactivity transient without reactor scram was modeled and calculated using analytical expressions for the space distributions of the temperature fields, combined with discrete numerical calculations for the time dependences of thermal power and temperatures. The transient analysis covered the time dependencies of reactivity, global thermal power, fuel heat flux and temperatures in fuel, cladding and cooling water. The model was implemented in Microsoft Office Excel, dividing the Excel file in several separated worksheets for input data, initial steady-state calculations, calculation of parameters non-depending on eigenvalues, eigenvalues determination, calculation of parameters depending on eigenvalues, transient calculation and graphical representation of intermediate and final results. The results show how the thermal power reaches a new equilibrium state due to the negative reactivity feedback derived from the fuel temperature increment. Nevertheless, the reactor mean power increases 40% during the first second and, in the hottest channel, the maximum fuel temperature goes to a significantly high value, slightly above 2100 deg C, after 8 seconds of transient. Consequently, the results confirm that certain degree of fuel damage could be expected in case of a reactor scram failure. Once the basic model has being established the scope of accidents for future analyses can be extended, modifying the nuclear power behavior (reactivity) during transient and the boundary conditions for coolant temperature. A more complex model is underway for an annular fuel element. (author)

  3. In vitro culture of functionally active buffalo hepatocytes isolated by using a simplified manual perfusion method.

    Directory of Open Access Journals (Sweden)

    Santanu Panda

    Full Text Available In farm animals, there is no suitable cell line available to understand liver-specific functions. This has limited our understanding of liver function and metabolism in farm animals. Culturing and maintenance of functionally active hepatocytes is difficult, since they survive no more than few days. Establishing primary culture of hepatocytes can help in studying cellular metabolism, drug toxicity, hepatocyte specific gene function and regulation. Here we provide a simple in vitro method for isolation and short-term culture of functionally active buffalo hepatocytes.Buffalo hepatocytes were isolated from caudate lobes by using manual enzymatic perfusion and mechanical disruption of liver tissue. Hepatocyte yield was (5.3 ± 0.66×107 cells per gram of liver tissue with a viability of 82.3 ± 3.5%. Freshly isolated hepatocytes were spherical with well contrasted border. After 24 hours of seeding onto fibroblast feeder layer and different extracellular matrices like dry collagen, matrigel and sandwich collagen coated plates, hepatocytes formed confluent monolayer with frequent clusters. Cultured hepatocytes exhibited typical cuboidal and polygonal shape with restored cellular polarity. Cells expressed hepatocyte-specific marker genes or proteins like albumin, hepatocyte nuclear factor 4α, glucose-6-phosphatase, tyrosine aminotransferase, cytochromes, cytokeratin and α1-antitrypsin. Hepatocytes could be immunostained with anti-cytokeratins, anti-albumin and anti α1-antitrypsin antibodies. Abundant lipid droplets were detected in the cytosol of hepatocytes using oil red stain. In vitro cultured hepatocytes could be grown for five days and maintained for up to nine days on buffalo skin fibroblast feeder layer. Cultured hepatocytes were viable for functional studies.We developed a convenient and cost effective technique for hepatocytes isolation for short-term culture that exhibited morphological and functional characteristics of active hepatocytes

  4. Reactive surface organometallic complexes observed using dynamic nuclear polarization surface enhanced NMR spectroscopy

    KAUST Repository

    Pump, Eva; Viger-Gravel, Jasmine; Abou-Hamad, Edy; Samantaray, Manoja; Hamzaoui, Bilel; Gurinov, Andrei; Anjum, Dalaver H.; Gajan, David; Lesage, Anne; Bendjeriou-Sedjerari, Anissa; Emsley, Lyndon; Basset, Jean-Marie

    2016-01-01

    Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) is an emerging technique that allows access to high-sensitivity NMR spectra from surfaces. However, DNP SENS usually requires the use of radicals as an exogenous source of polarization, which has so far limited applications for organometallic surface species to those that do not react with the radicals. Here we show that reactive surface species can be studied if they are immobilized inside porous materials with suitably small windows, and if bulky nitroxide bi-radicals (here TEKPol) are used as the polarization source and which cannot enter the pores. The method is demonstrated by obtaining significant DNP enhancements from highly reactive complelxes [(equivalent to Si-O-)W(Me)(5)] supported on MCM-41, and effects of pore size (6.0, 3.0 and 2.5 nm) on the performance are discussed.

  5. Reactive surface organometallic complexes observed using dynamic nuclear polarization surface enhanced NMR spectroscopy

    KAUST Repository

    Pump, Eva

    2016-08-15

    Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) is an emerging technique that allows access to high-sensitivity NMR spectra from surfaces. However, DNP SENS usually requires the use of radicals as an exogenous source of polarization, which has so far limited applications for organometallic surface species to those that do not react with the radicals. Here we show that reactive surface species can be studied if they are immobilized inside porous materials with suitably small windows, and if bulky nitroxide bi-radicals (here TEKPol) are used as the polarization source and which cannot enter the pores. The method is demonstrated by obtaining significant DNP enhancements from highly reactive complelxes [(equivalent to Si-O-)W(Me)(5)] supported on MCM-41, and effects of pore size (6.0, 3.0 and 2.5 nm) on the performance are discussed.

  6. Calculation-measurement comparison for control rods reactivity in RA-3 nuclear reactor

    International Nuclear Information System (INIS)

    Estryk, Guillermo; Gomez, Angel

    2002-01-01

    The RA-3 Nuclear Reactor of the Atomic Energy National Commission from Argentina, begun working with high enrichment fuel elements in 1967, and turned to low enrichment by 1990. During 1999 it was found out that several fuel elements had problems, so more than 50 % of them had to be removed from the core. Because of this, it was planned to go from core 93 to core 94 with special care from nuclear safety point of view. Core 94 was preceded by other five, T-1 to T-5, only as transitory ones. The care implied several nuclear parameters measurements: core reactivity excess, calibration of control rods, etc. Calculations were performed afterwards to simulate those measurements using the neutron diffusion code PUMA. The comparison shows a good agreement for more than 80% of the cases with differences lower than 10% in reactivity. The greatest differences were found in the last part of the control rods calibration and a better calculation of cell constants is planned to be done in order to improve the adjustment. (author)

  7. Billion-scale production of hepatocyte-like cells from human induced pluripotent stem cells.

    Science.gov (United States)

    Yamashita, Tomoki; Takayama, Kazuo; Sakurai, Fuminori; Mizuguchi, Hiroyuki

    2018-02-19

    Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells are expected to be utilized in drug screening and regenerative medicine. However, hepatocyte-like cells have not been fully used in such applications because it is difficult to produce such cells on a large scale. In this study, we tried to establish a method to mass produce hepatocyte-like cells using a three-dimensional (3D) cell culture bioreactor called the Rotary Cell Culture System (RCCS). RCCS enabled us to obtain homogenous hepatocyte-like cells on a billion scale (>10 9  cells). The gene expression levels of some hepatocyte markers (alpha-1 antitrypsin, cytochrome (CYP) 1A2, CYP2D6, and hepatocyte nuclear factor 4alpha) were higher in 3D-cultured hepatocyte-like cells than in 2D-cultured hepatocyte-like cells. This result suggests that RCCS could provide more suitable conditions for hepatocyte maturation than the conventional 2D cell culture conditions. In addition, more than 90% of hepatocyte-like cells were positive for albumin and could uptake low-density lipoprotein in the culture medium. We succeeded in the large-scale production of homogenous and functional hepatocyte-like cells from human iPS cells. This technology will be useful in drug screening and regenerative medicine, which require enormous numbers of hepatocyte-like cells. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Impacts of the turbogenerator reactive operation in the nuclear fuel burnup

    International Nuclear Information System (INIS)

    Oliveira, Helio Ricardo V. de; Martinez, Aquilino S.

    2002-01-01

    The parameterization of the losses in a turbogenerator in function of an operation with the electrical system reactive allowed to model in a simple and exact way the equations that define and they quantify the additional of nuclear potency that it should be generated by a reactor, in order to maintain the commitment with the national system operator, that is, the electric active power contracted. starting from this additional of nuclear power it was modeled the additional burn up of the fuel elements, as well as the numbers of effective days to full power wasted. it was promoted a safety analysis and some limitations due to the reactive operation of the electrical system. inside of this context it was made a financial evaluation in which we ask some questions to companies and government organs in order to define what losses are acceptable and also the reason why we don't use other technician resources such as: increase of the electrical mesh, electrical power injection in strategic points, capacitor banks and increase of the number the electrical plants. (author)

  9. Extended reactivity trace curves for nuclear power control with no power shooting

    International Nuclear Information System (INIS)

    Ratemi, W. M.; Elbuni, M. S.

    1995-01-01

    This paper introduces a new concept of reactivity trace curve (RTC) for nuclear power control with no power shooting. The concept is based on recent work of bernard et al. on the dynamic period of nuclear reactors. RTC-method is simulated for both a static effective decay constant corresponding to a one-group delayed neutrons model, and a dynamic effective decay constant corresponding to a six-group delayed neutrons model. A fitting to the RTC of a six-group reactor model resulted in a closed from formula for the RTC that couples the effect of both static and dynamic decay constants. Hence, introducing two 'fingerprints' for the reactor in concern to identify a closed from RTC formula capable of controlling the reactor power. Integration of the RTC with control rod integral curves results in the ρ-z-t diagram. This diagram relates the amount of recommended reactivity (RTC), the position of control rod, and the time required for power control. 8 figs

  10. Extended reactivity trace curves for nuclear power control with no power shooting

    Energy Technology Data Exchange (ETDEWEB)

    Ratemi, W M; Elbuni, M S [Faculty of engineering, Al Fateh universty Tripoli (Libyan Arab Jamahiriya)

    1995-10-01

    This paper introduces a new concept of reactivity trace curve (RTC) for nuclear power control with no power shooting. The concept is based on recent work of bernard et al. on the dynamic period of nuclear reactors. RTC-method is simulated for both a static effective decay constant corresponding to a one-group delayed neutrons model, and a dynamic effective decay constant corresponding to a six-group delayed neutrons model. A fitting to the RTC of a six-group reactor model resulted in a closed from formula for the RTC that couples the effect of both static and dynamic decay constants. Hence, introducing two `fingerprints` for the reactor in concern to identify a closed from RTC formula capable of controlling the reactor power. Integration of the RTC with control rod integral curves results in the {rho}-z-t diagram. This diagram relates the amount of recommended reactivity (RTC), the position of control rod, and the time required for power control. 8 figs.

  11. Reactivity variation's analysis in nuclear propulsion considering the operational real conditions requirements

    International Nuclear Information System (INIS)

    Pires, Leonardo Paredes; Santos, Rubens Souza dos; Lapa, Marcelo Franklin

    2015-01-01

    The work presented in this paper highlights the need for the study to determine the reactivity variation ramps needed and possible to meet the real operational conditions required by a nuclear submarine in this several operating phases. In accordance with the operational needs and necessary maneuvers in certain tactical situations, large power variations in the propulsion are demanded. As these sudden and severe changes in propulsion come from the thermal power of nuclear origin, the operation of the nuclear island has to know what kind of answers and criticality variations are necessary to meet each demand speed required. It should be noted that these criticality inserts are conditioned, not only by the propulsion needs, but fundamentally by the imperative need to ensure the core integrity and the chain reaction sustainability considering the phenomenons and complex effects, nonlinear and retro-fed involved. It has to be determined what is the past and required time for each criticality insertion is perceived as motor power. Considering the highlighted aspects, this article concludes and indicates to its end, the need to establish a base operating transitional agenda, according to the naval combat doctrine, to be tested and analyzed under the aspects and peculiarities of kinetic reactors, with the purpose of being generated the appropriate criticality curves for each real need and their respective times of anticipated action. (author)

  12. Reactivity variation's analysis in nuclear propulsion considering the operational real conditions requirements

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Leonardo Paredes; Santos, Rubens Souza dos; Lapa, Marcelo Franklin, E-mail: leonardo_paredes@icloud.com, E-mail: lapa@ien.gov.br, E-mail: rsantos@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The work presented in this paper highlights the need for the study to determine the reactivity variation ramps needed and possible to meet the real operational conditions required by a nuclear submarine in this several operating phases. In accordance with the operational needs and necessary maneuvers in certain tactical situations, large power variations in the propulsion are demanded. As these sudden and severe changes in propulsion come from the thermal power of nuclear origin, the operation of the nuclear island has to know what kind of answers and criticality variations are necessary to meet each demand speed required. It should be noted that these criticality inserts are conditioned, not only by the propulsion needs, but fundamentally by the imperative need to ensure the core integrity and the chain reaction sustainability considering the phenomenons and complex effects, nonlinear and retro-fed involved. It has to be determined what is the past and required time for each criticality insertion is perceived as motor power. Considering the highlighted aspects, this article concludes and indicates to its end, the need to establish a base operating transitional agenda, according to the naval combat doctrine, to be tested and analyzed under the aspects and peculiarities of kinetic reactors, with the purpose of being generated the appropriate criticality curves for each real need and their respective times of anticipated action. (author)

  13. Studies of the variability of the hepatocyte nuclear factor-1beta (HNF-1beta / TCF2) and the dimerization cofactor of HNF-1 (DcoH / PCBD) genes in relation to type 2 diabetes mellitus and beta-cell function

    DEFF Research Database (Denmark)

    Ek, J; Grarup, N; Urhammer, S A

    2001-01-01

    Mutations in the homeodomain-containing transcription factor hepatocyte nuclear factor-1beta (HNF-1beta) are known to cause a rare subtype of maturity-onset diabetes of the young (MODY5), which is associated with early-onset progressive non-diabetic renal dysfunction. To investigate whether...... mutations in HNF-1 are implicated in the pathogenesis of MODY or late-onset diabetes with and without nephropathy in Danish Caucasians we examined the HNF-1beta (TCF2) and the dimerization cofactor of HNF-1 (DCoH, PCBD) genes for mutations in 11 MODY probands, 28 type 2 diabetic patients with nephropathy...... comprising the DCoH gene revealed a previously described A-->G polymorphism located in the 3' untranslated region, which was not investigated further. In conclusion, mutations in HNF-1beta and DCoH are not a major cause of MODY or late onset type 2 diabetes in Danish Caucasian subjects....

  14. Importance weighting of local flux measurements to improve reactivity predictions in nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Dulla, Sandra; Hoh, Siew Sin; Nervo, Marta; Ravetto, Piero [Politecnico di Torino, Dipt. Energia (Italy)

    2015-07-15

    The reactivity monitoring is a key aspect for the safe operation of nuclear reactors, especially for subcritical source-driven systems. Various methods are available for both, off-line and on-line reactivity determination from direct measurements carried out on the reactor. Usually the methods are based on the inverse point kinetic model applied to signals from neutron detectors and results may be severely affected by space and spectral effects. Such effects need to be compensated and correction procedures have to be applied. In this work, a new approach is proposed, by using the full information from different local measurements to generate a global signal through a proper weighting of the signals provided by single neutron detectors. A weighting techique based on the use of the adjoint flux proves to be efficient in improving the prediction capability of inverse techniques. The idea is applied to the recently developed algorithm, named MAρTA, that can be used in both off-line and online modes.

  15. Radiation-induced PKC signaling system in cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Nakajima, Tetsuo; Yukawa, Osami

    1998-01-01

    Radiation effects on living organisms are mainly caused through reactive oxygen species (ROS) on living cells. It is known that ROS damages various membranes and the bio membranes play an important role in cellular signal transduction pathways. The effects of radiation on cellular signal transduction pathways in cultured rat hepatocytes have been studied

  16. RNA synthesis in primary cultures of adult rat hepatocytes

    International Nuclear Information System (INIS)

    Fugassa, E.; Gallo, G.; Voci, A.; Cordone, A.

    1983-01-01

    The ability of hepatocyte monolayers to synthesize RNA was investigated by measuring [3H]orotic acid incorporation into RNA and the total nuclear RNA polymerase activity as a function of the time in culture. The results demonstrate that primary cultures of hepatocytes maintained in a chemically defined serum- and hormone-free medium are able to synthesize RNA actively. This ability increases within the first 2 d of culture, despite the concomitant decrease in [3H]orotic acid uptake, and decreases only after 3 d. Factors such as serum, insulin, and dexamethasone, known to improve maintenance of functional hepatocytes, markedly stimulate the uptake of labeled precursor without apparently affecting the rate of RNA synthesis by cultured cells. It is suggested that the culture of adult rat hepatocytes provides a useful experimental model for the studies of hormonal regulation of transcription in liver

  17. Calculation methods of reactivity using derivatives of nuclear power and Filter fir; Metodos para o calculo da reatividade usando derivadas da potencia nuclear e o filtro FIR

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Daniel Suescun

    2007-07-01

    This work presents two new methods for the solution of the inverse point kinetics equation. The first method is based on the integration by parts of the integral of the inverse point kinetics equation, which results in a power series in terms of the nuclear power in time dependence. Applying some conditions to the nuclear power, the reactivity is represented as first and second derivatives of this nuclear power. This new calculation method for reactivity has special characteristics, amongst which the possibility of using different sampling periods, and the possibility of restarting the calculation, after its interruption associated it with a possible equipment malfunction, allowing the calculation of reactivity in a non-continuous way. Apart from this reactivity can be obtained with or without dependency on the nuclear power memory. The second method is based on the Laplace transform of the point kinetics equations, resulting in an expression equivalent to the inverse kinetics equation as a function of the power history. The reactivity can be written in terms of the summation of convolution with response to impulse, characteristic of a linear system. For its digital form the Z-transform is used, which is the discrete version of the Laplace transform. In this method it can be pointed out that the linear part is equivalent to a filter named Finite Impulse Response (Fir). The Fir filter will always be, stable and non-varying in time, and, apart from this, it can be implemented in the non-recursive way. This type of implementation does not require feedback, allowing the calculation of reactivity in a continuous way. The proposed methods were validated using signals with random noise and showing the relationship between the reactivity difference and the degree of the random noise. (author)

  18. Application of a Virtual Reactivity Feedback Control Loop in Non-Nuclear Testing of a Fast Spectrum Reactor

    International Nuclear Information System (INIS)

    Bragg-Sitton, Shannon M.; Forsbacka, Matthew

    2004-01-01

    For a compact, fast-spectrum reactor, reactivity feedback is dominated by core deformation at elevated temperature. Given the use of accurate deformation measurement techniques, it is possible to simulate nuclear feedback in non-nuclear electrically heated reactor tests. Implementation of simulated reactivity feedback in response to measured deflection is being tested at the Nasa Marshall Space Flight Center Early Flight Fission Test Facility (EFF-TF). During tests of the SAFE-100 reactor prototype, core deflection was monitored using a high resolution camera. 'Virtual' reactivity feedback was accomplished by applying the results of Monte Carlo calculations (MCNPX) to core deflection measurements; the computational analysis was used to establish the reactivity worth of various core deformations. The power delivered to the SAFE-100 prototype was then adjusted accordingly via kinetics calculations. The work presented in this paper will demonstrate virtual reactivity feedback as core power was increased from 1 kWt to 10 kWt, held approximately constant at 10 kWt, and then allowed to decrease based on the negative thermal reactivity coefficient. (authors)

  19. Factors affecting the differences in reactivity and dissolution rates between UO2 and spent nuclear fuel

    International Nuclear Information System (INIS)

    Shoesmith, D.W.; Tait, J.C.; Sunder, S.; Steward, S.; Russo, R.E.; Rudnicki, J.D.

    1996-08-01

    Strategies for the permanent disposal of spent nuclear fuel are being investigated by the U.S. Department of Energy at the Yucca Mountain site and by Atomic Energy of Canada Limited (AECL) in plutonic rock formations in the Canadian Shield. Uranium dioxide is the primary constituent of spent nuclear fuel and dissolution of the matrix is regarded as a necessary step for the release of radionuclides to repository groundwaters. In order to develop models to describe the dissolution of the U0 2 fuel matrix and subsequent release of radionuclides, it is necessary to understand both chemical and oxidative dissolution processes and how they can be affected by parameters such as groundwater composition, pH, temperature, surface area, radiolysis and redox potential. This report summarizes both published and on-going dissolution studies of U0 2 and both LWR and CANDU spent fuels being conducted at the Pacific Northwest Laboratory, Lawrence Livermore National Laboratory and Lawrence Berkeley Laboratory in the U.S. and at AECL's Whiteshell Laboratories in Canada. The studies include both dissolution tests and electrochemical experiments to measure uranium dissolution rates. The report focuses on identifying differences in reactivity towards aqueous dissolution between U0 2 and spent fuel samples as well as estimating bounding values for uranium dissolution rates. This review also outlines the basic tenets for the development of a dissolution model that is based on electrochemical principles. (author). 49 refs., 2 tabs., 11 figs

  20. Effects of hyperstoichiometry and fission products on the electrochemical reactivity of UO2 nuclear fuel

    International Nuclear Information System (INIS)

    Betteridge, J.S.; Scott, N.A.M.; Shoesmith, D.W.; Bahen, L.E.; Hocking, W.H.; Lucuta, P.G.

    1997-03-01

    The effects of hyperstoichiometry and fission products on the electrochemical reactivity Of UO 2 nuclear fuel have been systematically investigated using cyclic voltammetry and the O 2 reduction reaction. Significant constraints are placed on the active-site model for O 2 reduction by the modest impact of bulk hyperstoichiometry. Formation of the U 4 O 9 derivative phase was associated with a marked increase in transient surface oxidation/reduction processes, which probably involve localized attack and might be fostered by tensile stresses induced during oxidation. Electrocatalytic reduction Of O 2 on simulated nuclear fuel (SIMFUEL) has been determined to increase progressively with nominal burnup and pronounced enhancement of H 2 O reduction has been observed as well. Substitution of uranium by lower-valence (simulated) fission products, which was formerly considered the probable cause for this behaviour, has now been shown to merely provide good electrical conductivity. Instead, the enhanced reduction kinetics for O 2 and H 2 O on SIMFUEL can be fully accounted for by noble metals, which segregate to the UO 2 grain boundaries as micron-sized particles, despite their low effective surface area. Apparent convergence of the electrochemical properties Of UO 2 and SIMFUEL through natural corrosion likely reflects evolution toward a common active surface. (author)

  1. Nuclear criticality safety and time reactivity enhancement aspects of energy amplifier system devices

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, F [ENEA, Centro Ricerche Trisaia, Rotondelle, Matera (Italy). Direzione INFO

    1995-12-01

    As far as the Rubbia`s and colleagues proposal of innovating Energy Amplifier system (E.A.s.) device driven by a particle beam accelerator is concerned, four basic topics are comprised in the present paper: (1) A short outline of the nuclear aspects of Th-U and U-Pu fuel cycles regarding their general breeding and efficiency features. (2) The needed nuclear criticality control requirements have been studied in terms of safety regulating parameters on the basis of the ThO2 mixed oxides selected as fuel kind for the E.A.s. device technology development. Particular attention is devoted to time evolution of neutron multiplication factor since delayed development of the 233U buildup and so system reactivity are expected in the Th-U cycle. (3) Code E.A.s. device irradiation and post-irradiation modelling for determining higher actinides buildup, fission products formation and fuel consumption trends as function of time, system enrichment degree and flux level parameters. (4) The confirmation, on the basis of the same specific power irradiation, of expected actinides waste obtainment cleaner than the one deriving from the U-Pu cycle utilization. For this end, a model comparison of equivalent enriched fissile nuclides in both cycles has been devised as having, within the range of 0-700 days, ten irradiation periods of about 53 MW/ton specific power and equivalent cooling time post-irradiation periods.

  2. Simultaneous estimation of neutron density and reactivity in a nuclear reactor using a bank of Kalman filters

    International Nuclear Information System (INIS)

    Cortina, E.; D'Atellis, C.E.

    1990-01-01

    This paper reports on the problem of simultaneously estimating neutron density and reactivity while operating a nuclear reactor. It is solved by using a bank of Kalman filters as an estimator and applying a probabilistic test to determine which filter of the bank has the best performance

  3. Reactivity Impact of Difference of Nuclear Data Library for PWR Fuel Assembly Calculation by Using AEGIS Code

    International Nuclear Information System (INIS)

    Ohoka, Yasunori; Tatsumi, Masahiro; Sugimura, Naoki; Tabuchi, Masato

    2011-01-01

    In 2010, the latest version of the Japanese Evaluated Nuclear Data Library (JENDL-4.0) has been released by JAEA. JENDL-4.0 is major update from JENDL- 3.3, and confirmed to give good accuracy by integral test for fission reactor systems such as fast neutron system and thermal neutron system. In this study, we evaluated the reactivity impact due to difference between ENDF/B-VII.0 and JENDL-4.0 for PWR fuel assembly burnup calculation using AEGIS code which has been developed by Nuclear Engineering, Ltd. in cooperation with Nuclear Fuel Industries, Ltd. and Nagoya University

  4. Technical Basis for Peak Reactivity Burnup Credit for BWR Spent Nuclear Fuel in Storage and Transportation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, William BJ J [ORNL; Ade, Brian J [ORNL; Bowman, Stephen M [ORNL; Gauld, Ian C [ORNL; Ilas, Germina [ORNL; Mertyurek, Ugur [ORNL; Radulescu, Georgeta [ORNL

    2015-01-01

    Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission have initiated a multiyear project to investigate application of burnup credit for boiling-water reactor (BWR) fuel in storage and transportation casks. This project includes two phases. The first phase (1) investigates applicability of peak reactivity methods currently used in spent fuel pools (SFPs) to storage and transportation systems and (2) evaluates validation of both reactivity (keff) calculations and burnup credit nuclide concentrations within these methods. The second phase will focus on extending burnup credit beyond peak reactivity. This paper documents the first phase, including an analysis of lattice design parameters and depletion effects, as well as both validation components. Initial efforts related to extended burnup credit are discussed in a companion paper. Peak reactivity analyses have been used in criticality analyses for licensing of BWR fuel in SFPs over the last 20 years. These analyses typically combine credit for the gadolinium burnable absorber present in the fuel with a modest amount of burnup credit. Gadolinium burnable absorbers are used in BWR assemblies to control core reactivity. The burnable absorber significantly reduces assembly reactivity at beginning of life, potentially leading to significant increases in assembly reactivity for burnups less than 15–20 GWd/MTU. The reactivity of each fuel lattice is dependent on gadolinium loading. The number of gadolinium-bearing fuel pins lowers initial lattice reactivity, but it has a small impact on the burnup and reactivity of the peak. The gadolinium concentration in each pin has a small impact on initial lattice reactivity but a significant effect on the reactivity of the peak and the burnup at which the peak occurs. The importance of the lattice parameters and depletion conditions are primarily determined by their impact on the gadolinium depletion. Criticality code validation for BWR burnup

  5. Co-operation of the transcription factor hepatocyte nuclear factor-4 with Sp1 or Sp3 leads to transcriptional activation of the human haem oxygenase-1 gene promoter in a hepatoma cell line.

    Science.gov (United States)

    Takahashi, Shigeru; Matsuura, Naomi; Kurokawa, Takako; Takahashi, Yuji; Miura, Takashi

    2002-11-01

    We reported previously that the 5'-flanking region (nucleotides -1976 to -1655) of the human haem oxygenase-1 ( hHO-1 ) gene enhances hHO-1 promoter activity in human hepatoma HepG2 cells, but not in HeLa cells [Takahashi, Takahashi, Ito, Nagano, Shibahara and Miura (1999) Biochim. Biophys. Acta 1447, 231-235]. To define more precisely the regulatory elements involved, in the present study we have functionally dissected this region and localized the enhancer to a 50 bp fragment (-1793 to -1744). Site-direct mutagenesis analysis revealed that two regions were responsible for this enhancer activity, i.e. a hepatocyte nuclear factor-4 (HNF-4) homologous region and a GC box motif homologous region. Mutation in either region alone moderately decreased enhancer activity. However, mutations in both regions reduced promoter activity to the basal level. Electrophoretic mobility-shift assays demonstrated that the P5-2 fragment (-1793 to -1744) interacted with at least two nuclear factors, i.e. HNF-4 and Sp1/Sp3. Co-transfection experiments using Drosophila SL2 cells revealed that HNF-4 and Sp1/Sp3 synergistically stimulated the enhancer activity of the P5-2 fragment. These results indicate that co-operation of HNF-4 with Sp1 or Sp3 leads to the activation of hHO-1 gene expression in hepatoma cells.

  6. Repolarization of hepatocytes in culture.

    Science.gov (United States)

    Talamini, M A; Kappus, B; Hubbard, A

    1997-01-01

    We have evaluated the biochemical, morphological, and functional redevelopment of polarity in freshly isolated hepatocytes cultured using a double layer collagen gel sandwich technique. Western blot analysis showed increased cellular levels of the cell adhesion protein uvomorulin as cultured hepatocytes repolarized. Immunofluorescence studies using antibodies against domain-specific membrane proteins showed polarity as early as 48 hours, although the pattern of the polymeric Immunoglobulin-A receptor (pIgA-R) differed from in vivo liver. Electron microscopy showed developing bile canaliculi at 1 day. However, the functional presence of tight junctions was absent at 1 day, but present at 5 days. We further showed functional polarity to be present at 4 days by documenting the ability of cultured hepatocytes to metabolize and excrete fluorescein diacetate into visible bile canaliculi. We conclude that hepatocytes cultured appropriately develop morphological and functional polarity. Hepatocyte culture is therefore a useful tool for the study of mechanisms responsible for the development of polarized function.

  7. Nuclear data uncertainties propagation methods in Boltzmann/Bateman coupled problems: Application to reactivity in MTR

    International Nuclear Information System (INIS)

    Frosio, Thomas; Bonaccorsi, Thomas; Blaise, Patrick

    2016-01-01

    Highlights: • Hybrid methods are developed for uncertainty propagation. • These methods take into account the flux perturbation in the coupled problem. • We show that OAT and MC methods give coherent results, except for Pearson correlations. • Local sensitivity analysis is performed. - Abstract: A novel method has been developed to calculate sensitivity coefficients in coupled Boltzmann/Bateman problem for nuclear data (ND) uncertainties propagation on the reactivity. Different uncertainty propagation methodologies, such as One-At-a-Time (OAT) and hybrid Monte-Carlo/deterministic methods have been tested and are discussed on an actual example of ND uncertainty problem on a Material Testing Reactor (MTR) benchmark. Those methods, unlike total Monte Carlo (MC) sampling for uncertainty propagation and quantification (UQ), allow obtaining sensitivity coefficients, as well as Bravais–Pearson correlations values between Boltzmann and Bateman, during the depletion calculation for global neutronics parameters such as the effective multiplication coefficient. The methodologies are compared to a pure MC sampling method, usually considered as the “reference” method. It is shown that methodologies can seriously underestimate propagated variances, when Bravais–Pearson correlations on ND are not taken into account in the UQ process.

  8. National supply of reactivity control rods for Embalse nuclear power plant (CNE)

    International Nuclear Information System (INIS)

    Biondo, C.D.; Carloni, J.G.; Aba, J.A.

    1987-01-01

    The manufacture and supply on industrial scale of reactivity control rods for CNE (Embalse nuclear power plant) were developed by the National Atomic Energy Commission (CNEA) together with the private industry, as part of a program aimed to the substitution of imported supplies used in the operation of power plants by materials manufactured in Argentina. So far, the control rods were imported from Canada. In this work, the different development stages performed by CNEA and CONUAR S.A. are described, leading to the supply of a set of 21 cobalt rods to be included in a reactor of CNE in order to qualify this component. Among the main activities performed, the following stand out: specifications development, particularly those concerning to cobalt cores, evaluation of design documentation and elaboration of bidding conditions and a plan of manufacture and control. According to the results obtained during the service and the post-irradiation measurements, the design will be reviewed in order to undertake new manufacturing plans. (Author)

  9. Measurement and modelling of reactive transport in geological barriers for nuclear waste containment.

    Science.gov (United States)

    Xiong, Qingrong; Joseph, Claudia; Schmeide, Katja; Jivkov, Andrey P

    2015-11-11

    Compacted clays are considered as excellent candidates for barriers to radionuclide transport in future repositories for nuclear waste due to their very low hydraulic permeability. Diffusion is the dominant transport mechanism, controlled by a nano-scale pore system. Assessment of the clays' long-term containment function requires adequate modelling of such pore systems and their evolution. Existing characterisation techniques do not provide complete pore space information for effective modelling, such as pore and throat size distributions and connectivity. Special network models for reactive transport are proposed here using the complimentary character of the pore space and the solid phase. This balances the insufficient characterisation information and provides the means for future mechanical-physical-chemical coupling. The anisotropy and heterogeneity of clays is represented using different length parameters and percentage of pores in different directions. Resulting networks are described as mathematical graphs with efficient discrete calculus formulation of transport. Opalinus Clay (OPA) is chosen as an example. Experimental data for the tritiated water (HTO) and U(vi) diffusion through OPA are presented. Calculated diffusion coefficients of HTO and uranium species are within the ranges of the experimentally determined data in different clay directions. This verifies the proposed pore network model and validates that uranium complexes are diffusing as neutral species in OPA. In the case of U(vi) diffusion the method is extended to account for sorption and convection. Rather than changing pore radii by coarse grained mathematical formula, physical sorption is simulated in each pore, which is more accurate and realistic.

  10. Hepatocyte nuclear structure and subcellular distribution of copper in zebrafish Brachydanio rerio and roach Rutilus rutilus (Teleostei, Cyprinidae) exposed to copper sulphate

    Energy Technology Data Exchange (ETDEWEB)

    Paris-Palacios, Severine [Universite de Reims Champagne-Ardenne (URCA), UFR Sciences Exactes et Naturelles, Laboratoire d' Eco-Toxicologie, Institut International de Recherche sur les Ions Metalliques, B.P. 1039-51687 Reims cedex 2 (France)]. E-mail: severine.paris@univ-reims.fr; Biagianti-Risbourg, Sylvie [Universite de Reims Champagne-Ardenne (URCA), UFR Sciences Exactes et Naturelles, Laboratoire d' Eco-Toxicologie, Institut International de Recherche sur les Ions Metalliques, B.P. 1039-51687 Reims cedex 2 (France)]. E-mail: sylvie.biagianti@univ-reims.fr

    2006-05-10

    Copper is a trace element essential to life, but also a heavy metal with toxic effect clearly demonstrated. Cu induced perturbations in fish liver are well documented but the variability of the reported results is large. In this study two cyprinids, zebrafish and roach, were exposed to copper. Reported histocytological changes are either adaptative or degenerative depending on fish species, concentration of metal, and duration of exposure. Hepatic subcellular distribution of copper was determined by X-ray microanalysis in control and Cu-exposed roach and zebrafish. Sublethal copper sulphate contamination induced the development of a particular nucleolar alteration forming a network or honeycomb like structure in liver. This perturbation is observable in almost all the hepatocytes of zebrafish and roach exposed to copper for a minimum of 4 days of exposure. It seemed to concern more precisely the pars fibrosa. X-ray microanalysis showed that the appearance of network nucleolus was in relation to a Cu accumulation. Cu deposit was well located in the network as pars granulosa and nucloplasm showed very lower metal concentrations. The origin and consequence of network structure in nucleolus was discussed.

  11. Hepatocyte nuclear structure and subcellular distribution of copper in zebrafish Brachydanio rerio and roach Rutilus rutilus (Teleostei, Cyprinidae) exposed to copper sulphate

    International Nuclear Information System (INIS)

    Paris-Palacios, Severine; Biagianti-Risbourg, Sylvie

    2006-01-01

    Copper is a trace element essential to life, but also a heavy metal with toxic effect clearly demonstrated. Cu induced perturbations in fish liver are well documented but the variability of the reported results is large. In this study two cyprinids, zebrafish and roach, were exposed to copper. Reported histocytological changes are either adaptative or degenerative depending on fish species, concentration of metal, and duration of exposure. Hepatic subcellular distribution of copper was determined by X-ray microanalysis in control and Cu-exposed roach and zebrafish. Sublethal copper sulphate contamination induced the development of a particular nucleolar alteration forming a network or honeycomb like structure in liver. This perturbation is observable in almost all the hepatocytes of zebrafish and roach exposed to copper for a minimum of 4 days of exposure. It seemed to concern more precisely the pars fibrosa. X-ray microanalysis showed that the appearance of network nucleolus was in relation to a Cu accumulation. Cu deposit was well located in the network as pars granulosa and nucloplasm showed very lower metal concentrations. The origin and consequence of network structure in nucleolus was discussed

  12. Neutronic characterization of cylindrical core of minor excess reactivity in the nuclear reactor IPEN/MB-01 from the measure of neutron flux distribution and its reactivity ratio

    Energy Technology Data Exchange (ETDEWEB)

    Bitelli, Ulysses d' Utra; Aredes, Vitor O.G.; Mura, Luiz E.C.; Santos, Diogo F. dos; Silva, Alexandre P. da, E-mail: ubitelli@ipen.br, E-mail: vitoraredes@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    When compared to a rectangular parallelepiped configuration the cylindrical configuration of a nuclear reactor core has a better neutron economy because in this configuration the probability of the neutron leakage is smaller, causing an increase in overall reactivity in the system to the same amount of fuel used. In this work we obtained a critical cylindrical configuration with the control rods 89.50% withdraw from the active region of the IPEN/MB-01 core. This is the cylindrical configuration minimum possible excess of reactivity. Thus we obtained a cylindrical configuration with a diameter of only 28 fuel rods with lowest possible excess of reactivity. For this purpose, 112 peripheral fuel rods are removed from standard reactor core (rectangular parallelepiped of 28x28 fuel rods). In this configuration the excesses of reactivity is approximated 279 pcm. From there, we characterize the neutron field by measuring the spatial distribution of the thermal and epithermal neutron flux for the reactor operating power of 83 watts measured by neutron noise analysis technique and 92.08± 0.07 watts measured by activation technique [10]. The values of thermal and epithermal neutron flux in different directions, axial, radial north-south and radial east-west, are obtained in the asymptotic region of the reactor core, away from the disturbances caused by the reflector and control bar, by irradiating thin gold foils infinitely diluted (1% Au - 99% Al) with and without (bare) cadmium cover. In addition to the distribution of neutron flux, the moderator temperature coefficient, the void coefficient, calibration of the control rods were measured. (author)

  13. Determination of the excess of reactivity in a nuclear configuration and its influence on the power level

    International Nuclear Information System (INIS)

    Zuniga, Agustin; Tapia, Jose

    2014-01-01

    This work presents experimental results which show that the critical position of a given nuclear configuration changes with the reactor power (expressed by the current measurement). Thus, if the current is 0.6 x 10 -11 A (1 W), then the critical position is, BC1 = 0.0 % while 0.6 x 10 -9 A (100 W), BC1= 46.5 %. The difference is apparent because under a current of 10 -10 A, the reactivity is not significant. Therefore, it is recommended that for reactors like the RP-10 with a lot of neutrons at the 'background' level, the excess reactivity must be measured in current as 0.6 x 10 -9 A (100 W) not less. Finally, the excess of reactivity for the N o 42 configuration was determined, which was 3032 pcm with uncertainty less than 1 %. (authors).

  14. Development and validation of calculation schemes dedicated to the interpretation of small reactivity effects for nuclear data improvement

    International Nuclear Information System (INIS)

    Gruel, A.

    2011-01-01

    Reactivity measurements by the oscillation technique, as those performed in the Minerve reactor, enable to access various neutronic parameters on materials, fuels or specific isotopes. Usually, expected reactivity effects are small, about ten pcm at maximum. Then, the modeling of these experiments should be very precise, to obtain reliable feedback on the pointed parameters. Especially, calculation biases should be precisely identified, quantified and reduced to get precise information on nuclear data. The goal of this thesis is to develop a reference calculation scheme, with well quantified uncertainties, for in-pile oscillation experiments. In this work are presented several small reactivity calculation methods, based on deterministic and/or stochastic calculation codes. Those method are compared thanks to a numerical benchmark, against a reference calculation. Three applications of these methods are presented here: a purely deterministic calculation with exact perturbation theory formalism is used for the experimental validation of fission product cross sections, in the frame of reactivity loss studies for irradiated fuel; an hybrid method, based on a stochastic calculation and the exact perturbation theory is used for the readjustment of nuclear data, here 241 Am; and a third method, based on a perturbative Monte Carlo calculation, is used in a conception study. (author) [fr

  15. Reactivity determination in accelerator driven nuclear reactors by statistics from neutron detectors (Feynman-Alpha Method)

    International Nuclear Information System (INIS)

    Ceder, M.

    2002-03-01

    The Feynman-alpha method is used in traditional nuclear reactors to determine the subcritical reactivity of a system. The method is based on the measurement of the mean number and the variance of detector counts for different measurement times. The measurement is performed while a steady-state neutron flux is maintained in the reactor by an external neutron source, as a rule a radioactive source. From a plot of the variance-to-mean ratio as a function of measurement time ('gate length'), the reactivity can be determined by fitting the measured curve to the analytical solution. A new situation arises in the planned accelerator driven systems (ADS). An ADS will be run in a subcritical mode, and the steady flux will be maintained by an accelerator based source. Such a source has statistical properties that are different from those of a steady radioactive source. As one example, in a currently running European Community project for ADS research, the MUSE project, the source will be a periodically pulsed neutron generator. The theory of Feynman-alpha method needs to be extended to such nonstationary sources. There are two ways of performing and evaluating such pulsed source experiments. One is to synchronise the detector time gate start with the beginning of an incoming pulse. The Feynman-alpha method has been elaborated for such a case recently. The other method can be called stochastic pulsing. It means that there is no synchronisation between the detector time gate start and the source pulsing, i.e. the start of each measurement is chosen at a random time. The analytical solution to the Feynman-alpha formula from this latter method is the subject of this report. We have obtained an analytical Feynman-alpha formula for the case of stochastic pulsing by two different methods. One is completely based on the use of the symbolic algebra code Mathematica, whereas the other is based on complex function techniques. Closed form solutions could be obtained by both methods

  16. Reactivity determination in accelerator driven nuclear reactors by statistics from neutron detectors (Feynman-Alpha Method)

    Energy Technology Data Exchange (ETDEWEB)

    Ceder, M

    2002-03-01

    The Feynman-alpha method is used in traditional nuclear reactors to determine the subcritical reactivity of a system. The method is based on the measurement of the mean number and the variance of detector counts for different measurement times. The measurement is performed while a steady-state neutron flux is maintained in the reactor by an external neutron source, as a rule a radioactive source. From a plot of the variance-to-mean ratio as a function of measurement time ('gate length'), the reactivity can be determined by fitting the measured curve to the analytical solution. A new situation arises in the planned accelerator driven systems (ADS). An ADS will be run in a subcritical mode, and the steady flux will be maintained by an accelerator based source. Such a source has statistical properties that are different from those of a steady radioactive source. As one example, in a currently running European Community project for ADS research, the MUSE project, the source will be a periodically pulsed neutron generator. The theory of Feynman-alpha method needs to be extended to such nonstationary sources. There are two ways of performing and evaluating such pulsed source experiments. One is to synchronise the detector time gate start with the beginning of an incoming pulse. The Feynman-alpha method has been elaborated for such a case recently. The other method can be called stochastic pulsing. It means that there is no synchronisation between the detector time gate start and the source pulsing, i.e. the start of each measurement is chosen at a random time. The analytical solution to the Feynman-alpha formula from this latter method is the subject of this report. We have obtained an analytical Feynman-alpha formula for the case of stochastic pulsing by two different methods. One is completely based on the use of the symbolic algebra code Mathematica, whereas the other is based on complex function techniques. Closed form solutions could be obtained by both methods

  17. UDP-glucuronosyltransferase-dependent bioactivation of clofibric acid to a DNA-damaging intermediate in mouse hepatocytes.

    Science.gov (United States)

    Ghaoui, Roula; Sallustio, Benedetta C; Burcham, Philip C; Fontaine, Frank R

    2003-05-06

    Glucuronidation of a number of carboxyl-containing drugs generates reactive acyl glucuronide metabolites. These electrophilic species alkylate cell proteins and may be implicated in the pathogenesis of a number of toxic syndromes seen in patients receiving the parent aglycones. Whether acyl glucuronides also attack nuclear DNA is unknown, although the acyl glucuronide formed from clofibric acid was recently found to decrease the transfection efficiency of phage DNA and generate strand breaks in plasmid DNA in vitro. To determine if such a DNA damage occurs within a cellular environment, the comet assay (i.e. single-cell gel electrophoresis) was used to detect DNA lesions in the nuclear genome of isolated mouse hepatocytes cultured with clofibric acid. Overnight exposure to 50 microM and higher concentrations of clofibric acid produced concentration-dependent increases in the comet areas of hepatocyte nuclei, with 1 mM clofibrate producing a 3.6-fold elevation over controls. These effects closely coincided with culture medium concentrations of the glucuronide metabolite formed from clofibric acid, 1-O-beta-clofibryl glucuronide. Consistent with a role for glucuronidation in the DNA damage observed, the glucuronidation inhibitor borneol diminished glucuronide formation from 100 microM clofibrate by 98% and returned comet areas to baseline levels. Collectively, these results suggest that the acyl glucuronide formed from clofibric acid is capable of migrating from its site of formation within the endoplasmic reticulum to generate strand nicks in nuclear DNA.

  18. Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

    Directory of Open Access Journals (Sweden)

    Anayelly López-Islas

    2016-01-01

    Full Text Available Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

  19. Protective effects of hesperidin against oxidative stress of tert-butyl hydroperoxide in human hepatocytes.

    Science.gov (United States)

    Chen, Mingcang; Gu, Honggang; Ye, Yiyi; Lin, Bing; Sun, Lijuan; Deng, Weiping; Zhang, Jingzhe; Liu, Jianwen

    2010-10-01

    Increasing evidence regarding free radical generating agents and the inflammatory process suggest that accumulation of reactive oxygen species (ROS) could involve hepatotoxicity. Hesperidin, a naturally occurring flavonoid presents in fruits and vegetables, has been reported to exert a wide range of pharmacological effects that include antioxidant, anti-inflammatory, antihypercholesterolemic, and anticarcinogenic actions. However, the cytoprotection and mechanism of hesperidin to neutralize oxidative stress in human hepatic L02 cells remain unclear. In this work, we assessed the capability of hesperidin to prevent tert-butyl hydroperoxide (t-BuOOH)-induced cell damage by augmenting cellular antioxidant defense. Hesperidin significantly protected hepatocytes against t-BuOOH-induced cell cytotoxicity, such as mitochondrial membrane potential (MMP) deplete and lactate dehydrogenase (LDH) release. Hesperidin also remarkably prevented indicators of oxidative stress, such as the ROS and lipid peroxidation level in a dose-dependent manner. Western blot showed that hesperidin facilitated ERK/MAPK phosphorylation which appeared to be responsible for nuclear translocation of Nrf2, thereby inducing cytoprotective heme oxygenase-1 (HO-1) expression. Based on the results described above, it suggested that hesperidin has potential as a therapeutic agent in the treatment of oxidative stress-related hepatocytes injury and liver dysfunctions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. A novel -192c/g mutation in the proximal P2 promoter of the hepatocyte nuclear factor-4 alpha gene (HNF4A) associates with late-onset diabetes

    DEFF Research Database (Denmark)

    Ek, Jakob; Hansen, Sara P; Lajer, Maria

    2006-01-01

    Recently, it has been shown that mutations in the P2 promoter of the hepatocyte nuclear factor (HNF)-4 alpha gene (HNF4A) cause maturity-onset diabetes of the young (MODY), while single nucleotide polymorphisms in this locus are associated with type 2 diabetes. In this study, we examined 1,189 bp...... of the P2 promoter and the associated exon 1D of HNF4A for variations associated with diabetes in 114 patients with type 2 diabetes, 72 MODYX probands, and 85 women with previous gestational diabetes mellitus. A -192c/g mutation was found in five patients. We screened 1,587 diabetic subjects and 4......,812 glucose-tolerant subjects for the -192c/g mutation and identified 5 diabetic and 1 glucose-tolerant mutation carriers (P=0.004). Examination of the families showed that carriers of the -192c/g mutation had a significantly impaired glucose-stimulated insulin release and lower levels of serum total...

  1. High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) for Studies of Reactive Fabrics

    Science.gov (United States)

    2015-11-01

    spectroscopy (NMR) Self- decontaminating fabric Reactive fabric...reactions of reagents including chemical weapons on materials like concrete, soil , and sand, as well as reactive polymers.3,4,5,6,7 There are...sample. The rotor and cap can be cleaned by rinsing with solvent or decontamination solution and reused. 12.0 DATA ANALYSIS AND CALCULATIONS 12.1

  2. Analytical solution of point kinetics equations for linear reactivity variation during the start-up of a nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Palma, Daniel A.P. [CEFET QUIMICA de Nilopolis/RJ, 21941-914 Rio de Janeiro (Brazil)], E-mail: agoncalves@con.ufrj.br; Martinez, Aquilino S.; Goncalves, Alessandro C. [COPPE/UFRJ - Programa de Engenharia Nuclear, Rio de Janeiro (Brazil)

    2009-09-15

    The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting the variation of neutron density during the start-up of a nuclear reactor. In the practical case of an increase of nuclear reactor power resulting from the linear insertion of reactivity, the exact analytical solution cannot be obtained. Approximate solutions have been obtained in previous articles, based on considerations that need to be verifiable in practice. In the present article, an alternative analytic solution is presented for point kinetics equations in which the only approximation consists of disregarding the term of the second derivative for neutron density in relation to time. The results proved satisfactory when applied to practical situations in the start-up of a nuclear reactor through the control rods withdraw.

  3. Analytical solution of point kinetics equations for linear reactivity variation during the start-up of a nuclear reactor

    International Nuclear Information System (INIS)

    Palma, Daniel A.P.; Martinez, Aquilino S.; Goncalves, Alessandro C.

    2009-01-01

    The analytical solution of point kinetics equations with a group of delayed neutrons is useful in predicting the variation of neutron density during the start-up of a nuclear reactor. In the practical case of an increase of nuclear reactor power resulting from the linear insertion of reactivity, the exact analytical solution cannot be obtained. Approximate solutions have been obtained in previous articles, based on considerations that need to be verifiable in practice. In the present article, an alternative analytic solution is presented for point kinetics equations in which the only approximation consists of disregarding the term of the second derivative for neutron density in relation to time. The results proved satisfactory when applied to practical situations in the start-up of a nuclear reactor through the control rods withdraw.

  4. Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

    Science.gov (United States)

    Ikhtiar, Adnan M

    2015-07-01

    To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

  5. Comparison of para-aminophenol cytotoxicity in rat renal epithelial cells and hepatocytes.

    Science.gov (United States)

    Li, Ying; Bentzley, Catherine M; Tarloff, Joan B

    2005-04-01

    Several chemicals, including para-aminophenol (PAP), produce kidney damage in the absence of hepatic damage. Selective nephrotoxicity may be related to the ability of the kidney to reabsorb filtered water, thereby raising the intraluminal concentration of toxicants and exposing tubular epithelial cells to higher concentrations than would be present in other tissues. The present experiments tested the hypothesis that hepatocytes and renal epithelial cells exposed to equivalent concentrations of PAP would be equally susceptible to toxicity. Hepatocytes and renal epithelial cells were prepared by collagenase digestion of tissues obtained from female Sprague-Dawley rats. Toxicity was monitored using trypan blue exclusion, oxygen consumption and ATP content. We measured the rate of PAP clearance and formation of PAP-glutathione conjugate by HPLC. We found that renal epithelial cells accumulated trypan blue and showed declines in oxygen consumption and ATP content at significantly lower concentrations of PAP and at earlier time points than hepatocytes. The half-life of PAP in hepatocyte incubations was significantly shorter (0.71+/-0.07 h) than in renal epithelial cell incubations (1.33+/-0.23 h), suggesting that renal epithelial cells were exposed to PAP for longer time periods than hepatocytes. Renal epithelial cells formed significantly less glutathione conjugates of PAP (PAP-SG) than did hepatocytes, consistent with less efficient detoxification of reactive PAP intermediates by renal epithelial cells. Finally, hepatocytes contained significant more reduced glutathione (NPSH) than did renal epithelial cells, possibly explaining the enhanced formation of PAP-SG by this cell population. In conclusion, our data indicates that renal epithelial cells are intrinsically more susceptible to PAP cytotoxicity than are hepatocytes. This enhanced cytotoxicity may be due to longer exposure to PAP and/or reduced detoxification of reactive intermediates due to lower concentrations

  6. Reactive inspection response of NRC Region III to potential technical deficiencies identified in recent Nuclear Air Cleaning Conference papers

    International Nuclear Information System (INIS)

    Gill, C.F.

    1987-01-01

    In order to effectively meet its responsibility to protect the public health and safety, the Nuclear Regulatory Commission (NRC) nuclear power plant licensing and inspection programs respond to potential technical deficiencies identified by conference and professional society meeting papers when deemed appropriate. The NRC staff's response mechanisms for such technical deficiencies include: generic letters, Bulletins, Information Notices, Standard Review Plan (NUREG-0800) revisions, docketed Final Safety Analysis Report (FSAR) questions, special studies, special (reactive) inspection, and inspection program revisions. This paper describes reactive inspection efforts by Region III in response to potential technical deficiencies identified in recent air cleaning conference papers, including: post-accident effluent sample line deposition losses; failure to implement good engineering practices in the design, construction, and testing of Nuclear Air Treatment Systems (NATS); filter bypass via filter housing drain lines; spinster carbon degradation; use of silicone sealants and other temporary patching material in NATS; filter housing fire protection deluge system problems; lack of charcoal batch traceability; Quality Assurance records problems involving equipment, vendor, filter, and personnel qualifications; inadequate ANSI/ASME N510 acceptance criteria and tests; and failure to adequately demonstrate control room habitability per 10 CFR 50, Appendix A, General Design Criterion-19. Region III inspections indicate that many of these deficiencies appear to be prevalent. Inspection findings and utility responses to the findings are discussed. NRC Region III and Headquarters programmatic reactions to the identified generic problem areas are also discussed

  7. Buckling measurement in the IPEN/MB-01 nuclear reactor in cylindrical configuration of minor excess of reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Purgato, Rafael Turrini; Bitelli, Ulysses d' Utra; Aredes, Vitor Ottoni; Silva, Alexandre F. Povoa da; Santos, Diogo Feliciano dos; Lima, Ana Cecilia de Souza, E-mail: ubitelli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This work presents the results of experimental Buckling in the IPEN/MB-01 nuclear reactor in its cylindrical configuration with 28 fuel rods along its diameter. The IPEN/MB-01 is a zero power reactor designed to operate at a maximum power of 100 watts. It is a versatile nuclear facility, which allows for the simulation of all the characteristics of a nuclear power reactor making it an ideal test bed for this kind of measurement. A mapping of neutron flux inside the reactor is carried out in order to determine the total Buckling of the cylindrical configuration. The reactor was operated for one hour. Then, the activity of the fuel rods is measured by gamma ray spectrometry using a HPGe solid state detector and a suitable rod scanner. Photon energies of 276.6keV from {sup 239}Np (neutron capture (n,?) nuclear reaction) and 293.3keV from {sup 143}Ce (fission (n,f) nuclear reaction on both {sup 238}U and {sup 235}U) , are respectively along both axial and radial directions. Other measurements are performed using gold wires and foils along radial and axial directions of the reactor core. The three methods above resulted in a weighted average value of 93.18 ± 8.47 m-2 for the Total Buckling of this cylindrical core configuration with 28 control rods along its diameter with 568 fuel rods and only 271 pcm of excess reactivity. (author)

  8. Measurement of the CNA I's (Atucha I nuclear power plant) control rods reactivity during its commissioning on January 8th, 1990

    International Nuclear Information System (INIS)

    Waldman, R.M.; Gomez, A.

    1990-01-01

    Measurements were made on integral and differential calibration of rod 16, fuel racks RG and R3 and extinction reactivity during Atucha I nuclear power plant's commissioning on January 8th., 1990. These were the first physical measurements performed after the first critical nuclear power plant's commissioning. (Author) [es

  9. Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities

    International Nuclear Information System (INIS)

    MM Hall

    2006-01-01

    A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing

  10. No evidence for protective erythropoietin alpha signalling in rat hepatocytes

    Directory of Open Access Journals (Sweden)

    Frede Stilla

    2009-04-01

    Full Text Available Abstract Background Recombinant human erythropoietin alpha (rHu-EPO has been reported to protect the liver of rats and mice from ischemia-reperfusion injury. However, direct protective effects of rHu-EPO on hepatocytes and the responsible signalling pathways have not yet been described. The aim of the present work was to study the protective effect of rHu-EPO on warm hypoxia-reoxygenation and cold-induced injury to hepatocytes and the rHu-EPO-dependent signalling involved. Methods Loss of viability of isolated rat hepatocytes subjected to hypoxia/reoxygenation or incubated at 4°C followed by rewarming was determined from released lactate dehydrogenase activity in the absence and presence of rHu-EPO (0.2–100 U/ml. Apoptotic nuclear morphology was assessed by fluorescence microscopy using the nuclear fluorophores H33342 and propidium iodide. Erythropoietin receptor (EPOR, EPO and Bcl-2 mRNAs were quantified by real time PCR. Activation of JAK-2, STAT-3 and STAT-5 in hepatocytes and rat livers perfused in situ was assessed by Western blotting. Results In contrast to previous in vivo studies on ischemia-reperfusion injury to the liver, rHu-EPO was without any protective effect on hypoxic injury, hypoxia-reoxygenation injury and cold-induced apoptosis to isolated cultured rat hepatocytes. EPOR mRNA was identified in these cells but specific detection of the EPO receptor protein was not possible due to the lack of antibody specificity. Both, in the cultured rat hepatocytes (10 U/ml for 15 minutes and in the rat liver perfused in situ with rHu-EPO (8.9 U/ml for 15 minutes no evidence for EPO-dependent signalling was found as indicated by missing effects of rHu-EPO on phosphorylation of JAK-2, STAT-3 and STAT-5 and on the induction of Bcl-2 mRNA. Conclusion Together, these results indicate the absence of any protective EPO signalling in rat hepatocytes. This implies that the protection provided by rHu-EPO in vivo against ischemia-reperfusion and

  11. Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2016-11-01

    Full Text Available The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC. Levels of reactive oxygen species (ROS, malondialdehyde (MDA, and glutathione (GSH, activities of superoxide dismutase (SOD and catalase (CAT, mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

  12. The far and distal enhancers in the CYP3A4 gene co-ordinate the proximal promoter in responding similarly to the pregnane X receptor but differentially to hepatocyte nuclear factor-4alpha.

    Science.gov (United States)

    Liu, Fu-Jun; Song, Xiulong; Yang, Dongfang; Deng, Ruitang; Yan, Bingfang

    2008-01-01

    CYP3A4 (cytochrome P450 3A4) is involved in the metabolism of more than 50% of drugs and other xenobiotics. The expression of CYP3A4 is induced by many structurally dissimilar compounds. The PXR (pregnane X receptor) is recognized as a key regulator for the induction, and the PXR-directed transactivation of the CYP3A4 gene is achieved through a co-ordinated mechanism of the distal module with the proximal promoter. Recently, a far module was found to support constitutive expression of CYP3A4. The far module, like the distal module, is structurally clustered by a PXR response element (F-ER6) and elements recognized by HNF-4alpha (hepatocyte nuclear receptor-4alpha). We hypothesized that the far module supports PXR transactivation of the CYP3A4 gene. Consistent with the hypothesis, fusion of the far module to the proximal promoter of CYP3A4 markedly increased rifampicin-induced reporter activity. The increase was synergistically enhanced when both the far and distal modules were fused to the proximal promoter. The increase, however, was significantly reduced when the F-ER6 was disrupted. Chromatin immunoprecipitation detected the presence of PXR in the far module. Interestingly, HNF-4alpha increased the activity of the distal-proximal fused promoter, but decreased the activity of the far-proximal fused promoter. Given the fact that induction of CYP3A4 represents an important detoxification mechanism, the functional redundancy and synergistic interaction in supporting PXR transactivation suggest that the far and distal modules ensure the induction of CYP3A4 during chemical insults. The difference in responding to HNF-4alpha suggests that the magnitude of the induction is under control through various transcriptional networks.

  13. Exocrine pancreatic function in hepatocyte nuclear factor 1β-maturity-onset diabetes of the young (HNF1B-MODY) is only moderately reduced: compensatory hypersecretion from a hypoplastic pancreas.

    Science.gov (United States)

    Tjora, E; Wathle, G; Erchinger, F; Engjom, T; Molven, A; Aksnes, L; Haldorsen, I S; Dimcevski, G; Raeder, H; Njølstad, P R

    2013-08-01

    To examine the exocrine pancreatic function in carriers of the hepatocyte nuclear factor 1β gene (HNF1B) mutation by direct testing. Patients with HNF1B mutations and control subjects were assessed using rapid endoscopic secretin tests and secretin-stimulated magnetic resonance imaging. Seven patients and 25 controls underwent endoscopy, while eight patients and 20 controls had magnetic resonance imaging. Ductal function was assessed according to peak bicarbonate concentrations and acinar function was assessed according to peak digestive enzyme activities in secretin-stimulated duodenal juice. The association of pancreatic exocrine function and diabetes status with pancreatic gland volume was examined. The mean increase in secretin-stimulated duodenal fluid was smaller in patients than controls (4.0 vs 6.4 ml/min; P = 0.003). We found lower ductal function in patients than controls (median peak bicarbonate concentration: 73 vs 116 mEq/L; P function (median peak lipase activity: 6.4 vs 33.5 kU/ml; P = 0.01; median peak elastase activity: 0.056 vs 0.130 U/ml; P = 0.01). Pancreatic fluid volume outputs correlated significantly with pancreatic gland volumes (r² = 0.71, P = 0.008) in patients. The total fluid output to pancreatic gland volume ratios were higher in patients than controls (4.5 vs 1.3 ml/cm³; P = 0.03), suggesting compensatory hypersecretion in the remaining gland. Carriers of the HNF1B mutation have lower exocrine pancreatic function involving both ductal and acinar cells. Compensatory hypersecretion suggests that the small pancreas of HNF1B mutation carriers is attributable to hypoplasia, not atrophy. © 2013 The Authors. Diabetic Medicine © 2013 Diabetes UK.

  14. Implementation of New Reactivity Measurement System and New Reactor Noise Analysis Equipment in a VVER-440 Nuclear Power Plant

    Science.gov (United States)

    Vegh, János; Kiss, Sándor; Lipcsei, Sándor; Horvath, Csaba; Pos, István; Kiss, Gábor

    2010-10-01

    The paper deals with two recently developed, high-precision nuclear measurement systems installed at the VVER-440 units of the Hungarian Paks NPP. Both developments were motivated by the reactor power increase to 108%, and by the planned plant service time extension. The first part describes the RMR start-up reactivity measurement system with advanced services. High-precision picoampere meters were installed at each reactor unit and measured ionization chamber current signals are handled by a portable computer providing data acquisition and online reactivity calculation service. Detailed offline evaluation and analysis of reactor start-up measurements can be performed on the portable unit, too. The second part of the paper describes a new reactor noise diagnostics system using state-of-the-art data acquisition hardware and signal processing methods. Details of the new reactor noise measurement evaluation software are also outlined. Noise diagnostics at Paks NPP is a standard tool for core anomaly detection and for long-term noise trend monitoring. Regular application of these systems is illustrated by real plant data, e.g., results of standard reactivity measurements during a reactor startup session are given. Noise applications are also illustrated by real plant measurements; results of core anomaly detection are presented.

  15. Impacts of the turbogenerator reactive operation in the nuclear fuel burnup; Impactos da operacao reativa do turbogerador na queima do combustivel nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Helio Ricardo V. de; Martinez, Aquilino S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2002-07-01

    The parameterization of the losses in a turbogenerator in function of an operation with the electrical system reactive allowed to model in a simple and exact way the equations that define and they quantify the additional of nuclear potency that it should be generated by a reactor, in order to maintain the commitment with the national system operator, that is, the electric active power contracted. starting from this additional of nuclear power it was modeled the additional burn up of the fuel elements, as well as the numbers of effective days to full power wasted. it was promoted a safety analysis and some limitations due to the reactive operation of the electrical system. inside of this context it was made a financial evaluation in which we ask some questions to companies and government organs in order to define what losses are acceptable and also the reason why we don't use other technician resources such as: increase of the electrical mesh, electrical power injection in strategic points, capacitor banks and increase of the number the electrical plants. (author)

  16. The AEP Barnbook DATLIB. Nuclear Reaction Cross Sections and Reactivity Parameter Library and Files

    International Nuclear Information System (INIS)

    Feldbacher, R.

    1987-10-01

    Nuclear reaction data for light isotope charged particle reactions (Z<6) have been compiled. This hardcopy contains file headers, plots and an extended bibliography. Numerical data files and processing routines are available on tape at IAEA-NDS. (author). Refs

  17. Monitoring of the temperature reactivity coefficient at the PWR nuclear plant

    International Nuclear Information System (INIS)

    Kostic, Lj.

    1996-01-01

    For monitoring temperature coefficient of reactivity of pressurized water reactor a method based on the correction of fluctuation in signals of i-core neutron detectors and core-exit thermocouples and neural network paradigm is used it is shown that the moderator temperature coefficient of relativity can be predicted with the aid of the back propagation neural network technique by measuring the frequency response function between the in-core neutron flux and the core-exit coolant temperature

  18. Measurements of the Reactivity Properties of the Aagesta Nuclear Power Reactor at Zero Power

    Energy Technology Data Exchange (ETDEWEB)

    Bernander, G

    1967-07-15

    The moderator level and temperature coefficients of reactivity and control rod differential reactivity worths have been determined at zero power by means of period measurements. The moderator level coefficient and the corresponding critical level have been measured for the 32, 68 and 136 fuel assembly cores at room temperature for cores with and without control rods. From these results the worths of control rods have been derived. HETERO calculations give up to 15 % lower values than the experimental results. The cold fresh core has an excess reactivity of 9.0 {+-} 0.2 %. The temperature coefficient and differential control rod worths were measured for the fully loaded core with filled tank in the temperature range between 30 and 210 deg C. Critical positions as a function of temperature were obtained for the corresponding control rod groups. No relevant calculations of the temperature coefficient for comparison with the experimental values have yet been made, but the experimental results together with measured critical control rod positions give good opportunities to check calculational programs. HETERO has been shown in these cases to reproduce differential control rod worths and critical positions fairly well. However, a certain underestimation of the rod effectiveness is quite noticeable. The relative increase in control rod effectiveness with a temperature change from 20 to 220 deg C has been estimated to be 0.29 {+-} 0.06.

  19. A role for nuclear translocation of tripeptidyl-peptidase II in reactive oxygen species-dependent DNA damage responses

    Energy Technology Data Exchange (ETDEWEB)

    Preta, Giulio; Klark, Rainier de [Center for Molecular Medicine (CMM), Department of Medicine, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm (Sweden); Glas, Rickard, E-mail: rickard.glas@ki.se [Center for Molecular Medicine (CMM), Department of Medicine, Karolinska Institutet, Karolinska University Hospital, 171 76 Stockholm (Sweden)

    2009-11-27

    Responses to DNA damage are influenced by cellular metabolism through the continuous production of reactive oxygen species (ROS), of which most are by-products of mitochondrial respiration. ROS have a strong influence on signaling pathways during responses to DNA damage, by relatively unclear mechanisms. Previous reports have shown conflicting data on a possible role for tripeptidyl-peptidase II (TPPII), a large cytosolic peptidase, within the DNA damage response. Here we show that TPPII translocated into the nucleus in a p160-ROCK-dependent fashion in response to {gamma}-irradiation, and that nuclear expression of TPPII was present in most {gamma}-irradiated transformed cell lines. We used a panel of nine cell lines of diverse tissue origin, including four lymphoma cell lines (T, B and Hodgkins lymphoma), a melanoma, a sarcoma, a colon and two breast carcinomas, where seven out of nine cell lines showed nuclear TPPII expression after {gamma}-irradiation. Further, this required cellular production of ROS; treatment with either N-acetyl-Cysteine (anti-oxidant) or Rotenone (inhibitor of mitochondrial respiration) inhibited nuclear accumulation of TPPII. The local density of cells was important for nuclear accumulation of TPPII at early time-points following {gamma}-irradiation (at 1-4 h), indicating a bystander effect. Further, we showed that the peptide-based inhibitor Z-Gly-Leu-Ala-OH, but not its analogue Z-Gly-(D)-Leu-Ala-OH, excluded TPPII from the nucleus. This correlated with reduced nuclear expression of p53 as well as caspase-3 and -9 activation in {gamma}-irradiated lymphoma cells. Our data suggest a role for TPPII in ROS-dependent DNA damage responses, through alteration of its localization from the cytosol into the nucleus.

  20. Ultrastructure of hepatocyte nuclei in irradiated, adrenalectomized rats

    Energy Technology Data Exchange (ETDEWEB)

    Orkisz, S.; Bartel, H.; Kmiec, B. (Military Medical Academy, Lodz (Poland))

    1984-01-01

    A cytochemical study of hepatocyte nuclei of adrenalectomized and irradiated rats was performed. After irradiation alone, the behaviour of the ribonucleoprotein components was studied according to Bernhard. The findings suggest that a delay occurs in the synthesis of preribosomal RNA in the nucleoli and in the transport of messenger RNA to the cytoplasm. The indirect effect of ionizing radiation on nuclear RNA synthesis is assumed to occur through the influence of cortical steroid hormones on the transcription process.

  1. Hepatocyte growth factor profile with breast cancer

    Directory of Open Access Journals (Sweden)

    Hoda A EL-Attar

    2011-01-01

    Full Text Available Background: The multifunctional hepatocyte growth factor (HGF is the ligand of c-Met receptor; it plays important role in mammary differentiation. HGF-Met signaling is a critical downstream function of c-Src-Stat3 pathway in mammalian tumorigenesis. Aim: Evaluation of tissue c-Met receptor hepatocyte growth factor receptor (HGFR and serum level of HGF in female breast ductal carcinoma. Materials and Methods: Sixty-eight premenopausal females were divided as 30 control females subdivided into: [Group 1] 15 healthy volunteer females and [Group 2] five with fibrocystic disease and 10 having fibroadenoma of the breast and patients group [Group 3] consisted of 38 female patients with breast ductal carcinoma. Thorough clinical examination, preoperative fine needle aspiration cytology, estimation of fasting serum glucose, urea, creatinine, and uric acid levels, alanine aminotransferase activities, C-reactive protein, HGF level, before surgery and histopathological examination of the breast masses, and immunohistochemical detection of HGFR were done. Results and Conclusions: Significant increase in serum HGF levels were found in patients with breast cancer as compared with controls. Significant increase was also seen in patients with breast cancer with and without lymph node metastasis when each subgroup was compared with controls. Serum level of HGF is an independent prognostic indicator of breast cancer. Fibrocystic disease of the breast showed weak HGFR expression, while in normal tissue, HGFR was scanty; meanwhile, breast invasive ductal carcinoma showed homogenous strong reaction to HGFR. HGF is only one of a number of key factors involved in breast cancer and preoperative high serum HGF levels and malignancy occur usually together.

  2. Impact of nuclear data uncertainties on the reactivity of an AN ASTRID-like sodium fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Martínez, A.; García-Herranz, N.; Romojaro, P.; Alvarez-Velarde, F.; López, D.

    2015-07-01

    The EU 7 th Framework Project ESNII+ was launched in 2013 in support of the initiative ESNII (European Sustainable Nuclear Industrial Initiative) whose purpose is to design, license, construct and begin the operation of the Sodium Fast Reactor Prototype, ASTRID, before 2025. An ASTRID-like core design has been analyzed (see other paper in this conference) and it was found to have a global negative reactivity feedback to sodium voiding. Taking into account the importance of feedback coefficients on core safety, the influence of the uncertainties in nuclear data should be assessed to have an exhaustive picture of the actual safety margins of ASTRID design. The objective of this work is to contribute to the improvement of the safety of ASTRID nuclear design by assessing different uncertainty propagation methodologies of the TSUNAMI-3D module of the SCALE system [ 1 ]. In this work, TSUNAMI-3D is applied to a pin-cell of the inner zone of the ASTRID core in order to select the optimal TSUNAMI-3D parameters. These parameters will be applied in future works to the Sensitivity and Uncertainty (S/U) analysis of the full core. (Author)

  3. Predicting fissile content of spent nuclear fuel assemblies with the Passive Neutron Albedo Reactivity technique and Monte Carlo code emulation

    International Nuclear Information System (INIS)

    Conlin, Jeremy Lloyd; Tobin, Stephen J.

    2011-01-01

    There is a great need in the safeguards community to be able to nondestructively quantify the mass of plutonium of a spent nuclear fuel assembly. As part of the Next Generation of Safeguards Initiative, we are investigating several techniques, or detector systems, which, when integrated, will be capable of quantifying the plutonium mass of a spent fuel assembly without dismantling the assembly. This paper reports on the simulation of one of these techniques, the Passive Neutron Albedo Reactivity with Fission Chambers (PNAR-FC) system. The response of this system over a wide range of spent fuel assemblies with different burnup, initial enrichment, and cooling time characteristics is shown. A Monte Carlo method of using these modeled results to estimate the fissile content of a spent fuel assembly has been developed. A few numerical simulations of using this method are shown. Finally, additional developments still needed and being worked on are discussed. (author)

  4. Reactivity worth measurements on fast burst reactor Caliban - description and interpretation of integral experiments for the validation of nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Richard, B. [Commissariat a l' Energie Atomique et Aux Energies Alternatives CEA, DAM, VALDUC, F-21120 Is-sur-Tille (France)

    2012-07-01

    Reactivity perturbation experiments using various materials are being performed on the HEU fast core CALIBAN, an experimental device operated by the CEA VALDUC Criticality and Neutron Transport Research Laboratory. These experiments provide valuable information to contribute to the validation of nuclear data for the materials used in such measurements. This paper presents the results obtained in a first series of measurements performed with Au-197 samples. Experiments which have been conducted in order to improve the characterization of the core are also described and discussed. The experimental results have been compared to numerical calculation using both deterministic and Monte Carlo neutron transport codes with a simplified model of the reactor. This early work led to a methodology which will be applied to the future experiments which will concern other materials of interest. (authors)

  5. Technical and economic feasibility study for the reactivation of the integral test facility of IPEN/CNEN Nuclear Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    Biaty, Flávia P.; Rocha, Marcelo da S.; Oliveira, Otávio L. de, E-mail: flavia.biaty@usp.br, E-mail: msrocha@ipen.br, E-mail: otavioluis@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    The Integral Test Facility of Nuclear Engineering Center (CEN/IPEN/CNEN-SP), known as 'Loop 70', is a semi-industrial thermal-hydraulic test facility and can operate as a BWR (Boiling Water Reactor) or a PWR (Pressurizing Water Reactor) mode. Designed and built in the 1980's, it is currently disabled. The experimental circuits ('test loop') are facilities that reproduce the thermohydraulic and fluid dynamic conditions that occur inside a reactor and are used to simulate the practical reality which it is not possible to be obtained through mathematical models. In this context, this research project aims the development of a Business Plan to analyze the technical and economic feasibility related to the reactivation of the facility. This methodology (adapted to the government sector) is a decision-making tool that will offer a wide perspective of the project, set the guidelines and actions that will define the future of the facility and provide a general rule to make investments on it. This paper presents the historic aspects to better understand the Loop 70's current situation. It also presents information about similar facilities around the world, services that can be offered (thermal-hydraulics parameters measurements, equipment qualification and transient analysis due accident situations), results of the strategic analysis (SWOT) performed, specific goals for each critical success or failure factor of the facility, financial aspects related to the reactivation and an overview of the facility's perspectives. (author)

  6. Technical and economic feasibility study for the reactivation of the integral test facility of IPEN/CNEN Nuclear Engineering Center

    International Nuclear Information System (INIS)

    Biaty, Flávia P.; Rocha, Marcelo da S.; Oliveira, Otávio L. de

    2017-01-01

    The Integral Test Facility of Nuclear Engineering Center (CEN/IPEN/CNEN-SP), known as 'Loop 70', is a semi-industrial thermal-hydraulic test facility and can operate as a BWR (Boiling Water Reactor) or a PWR (Pressurizing Water Reactor) mode. Designed and built in the 1980's, it is currently disabled. The experimental circuits ('test loop') are facilities that reproduce the thermohydraulic and fluid dynamic conditions that occur inside a reactor and are used to simulate the practical reality which it is not possible to be obtained through mathematical models. In this context, this research project aims the development of a Business Plan to analyze the technical and economic feasibility related to the reactivation of the facility. This methodology (adapted to the government sector) is a decision-making tool that will offer a wide perspective of the project, set the guidelines and actions that will define the future of the facility and provide a general rule to make investments on it. This paper presents the historic aspects to better understand the Loop 70's current situation. It also presents information about similar facilities around the world, services that can be offered (thermal-hydraulics parameters measurements, equipment qualification and transient analysis due accident situations), results of the strategic analysis (SWOT) performed, specific goals for each critical success or failure factor of the facility, financial aspects related to the reactivation and an overview of the facility's perspectives. (author)

  7. Acidosis-induced downregulation of hepatocyte mitochondrial aquaporin-8 and ureagenesis from ammonia.

    Science.gov (United States)

    Molinas, Sara M; Soria, Leandro R; Marrone, Julieta; Danielli, Mauro; Trumper, Laura; Marinelli, Raúl A

    2015-08-01

    It has been proposed that, during metabolic acidosis, the liver downregulates mitochondrial ammonia detoxification via ureagenesis, a bicarbonate-consuming process. Since we previously demonstrated that hepatocyte mitochondrial aquaporin-8 channels (mtAQP8) facilitate the uptake of ammonia and its metabolism into urea, we studied whether mtAQP8 is involved in the liver adaptive response to acidosis. Primary cultured rat hepatocytes were adapted to acidosis by exposing them to culture medium at pH 7.0 for 40 h. Control cells were exposed to pH 7.4. Hepatocytes exposed to acid medium showed a decrease in mtAQP8 protein expression (-30%, p ammonia was assessed by incubating the cells with (15)N-labeled ammonia and measuring (15)N-labeled urea synthesis by nuclear magnetic resonance. Reduced ureagenesis was found in acidified hepatocytes (-31%, p ammonia in response to acidosis.

  8. Biological variation and reference intervals for circulating osteopontin, osteoprotegerin, total soluble receptor activator of nuclear factor kappa B ligand and high-sensitivity C-reactive protein

    DEFF Research Database (Denmark)

    Sennels, H P; Jacobsen, Søren; Jensen, T

    2007-01-01

    Objective. Monitoring inflammatory diseases and osteoclastogenesis with osteopontin (OPN), osteoprotegerin (OPG), total soluble receptor activator of nuclear factor kappa B ligand (total sRANKL) and high-sensitivity C-reactive protein (hsCRP) has recently attracted increased interest. The purpose...

  9. Structure-reactivity relationships in the interactions between humic substances, pollutants from the nuclear cycle, and mineral surfaces

    International Nuclear Information System (INIS)

    Reiller, Pascal

    2015-01-01

    This document proposes an analysis of the structure-reactivity relationships in the interaction between humic substances, metallic pollutants from the nuclear cycle, and mineral surfaces. It composes the scientific document, which allowed the author to defend a Habilitation degree. It is mainly focused on the research works into which the author have been involved in on this particular thematic. Humic substances are issued from the degradation of the living. They have an important influence onto migration of metals in the environment. They are showing particular intrinsic physic and chemical, metal complexation, and adsorption onto mineral surfaces properties, which render the global comprehension of the different mechanisms somehow difficult. These three aspects are covered in this document. The first part is dedicated to the studies on composition, structure, and organization of humic substances, which cannot be considered as a well-defined type of chemical. They are a heterogeneous degradation product with a supramolecular organization, which is showing fractal properties from fractions up to several nanometers. Second part is on the complexation reactions. The different modelling strategies come from the difficulties on apprehending composition, structure, and organization of humic substances. The different models used are showing more or less strongly empiric characteristics. They can be derived from the mass action law, or explicitly account for heterogeneity, acid-basic, or ionic strength related parameters. The third and latter part covers the adsorption studies. The main property is adsorptive fractionation, which induces modification of chemical composition of humic substances between the surface and the solution. It also induces modification of complexation properties between the adsorbed and non-adsorbed fractions. Because of adsorptive fractionation, and the particular influence of ionic strength on humic substances, and of complexed metals, adsorption

  10. Factor VIIa binding and internalization in hepatocytes

    DEFF Research Database (Denmark)

    Hjortoe, G; Sorensen, B B; Petersen, L C

    2005-01-01

    The liver is believed to be the primary clearance organ for coagulation proteases, including factor VIIa (FVIIa). However, at present, clearance mechanisms for FVIIa in liver are unknown. To obtain information on the FVIIa clearance mechanism, we investigated the binding and internalization...... no effect. HEPG2 cells internalized FVIIa with a rate of 10 fmol 10(-5) cells h(-1). In contrast to HEPG2 cells, FVIIa binding to primary rat hepatocytes was completely independent of TF, and excess unlabeled FVIIa partly reduced the binding of 125I-FVIIa to rat hepatocytes. Further, compared with HEPG2...... cells, three- to fourfold more FVIIa bound to rat primary hepatocytes, and the bound FVIIa was internalized at a faster rate. Similar FVIIa binding and internalization profiles were observed in primary human hepatocytes. Plasma inhibitors had no effect on FVIIa binding and internalization in hepatocytes...

  11. Hypoxia-inducible factor-dependent production of profibrotic mediators by hypoxic hepatocytes.

    Science.gov (United States)

    Copple, Bryan L; Bustamante, Juan J; Welch, Timothy P; Kim, Nam Deuk; Moon, Jeon-Ok

    2009-08-01

    During the development of liver fibrosis, mediators are produced that stimulate cells in the liver to differentiate into myofibroblasts and to produce collagen. Recent studies demonstrated that the transcription factor, hypoxia-inducible factor-1alpha (HIF-1alpha), is critical for upregulation of profibrotic mediators, such as platelet-derived growth factor-A (PDGF-A), PDGF-B and plasminogen activator inhibitor-1 (PAI-1) in the liver, during the development of fibrosis. What remains unknown is the cell type-specific regulation of these genes by HIF-1alpha in liver cell types. Accordingly, the hypothesis was tested that HIF-1alpha is activated in hypoxic hepatocytes and regulates the production of profibrotic mediators by these cells. In this study, hepatocytes were isolated from the livers of control and HIF-1alpha- or HIF-1beta-deficient mice and exposed to hypoxia. Exposure of primary mouse hepatocytes to 1% oxygen stimulated nuclear accumulation of HIF-1alpha and upregulated PAI-1, vascular endothelial cell growth factor and the vasoactive peptides adrenomedullin-1 (ADM-1) and ADM-2. In contrast, the levels of PDGF-A and PDGF-B mRNAs were unaffected in these cells by hypoxia. Exposure of HIF-1alpha-deficient hepatocytes to 1% oxygen only partially prevented upregulation of these genes, suggesting that other hypoxia-regulated transcription factors, such as HIF-2alpha, may also regulate these genes. In support of this, HIF-2alpha was activated in hypoxic hepatocytes, and exposure of HIF-1beta-deficient hepatocytes to 1% oxygen completely prevented upregulation of PAI-1, vascular endothelial cell growth factor and ADM-1, suggesting that HIF-2alpha may also contribute to upregulation of these genes in hypoxic hepatocytes. Collectively, our results suggest that HIFs may be important regulators of profibrotic and vasoactive mediators by hypoxic hepatocytes.

  12. The potential for using slags activated with near neutral salts as immobilisation matrices for nuclear wastes containing reactive metals

    Science.gov (United States)

    Bai, Y.; Collier, N. C.; Milestone, N. B.; Yang, C. H.

    2011-06-01

    The UK currently uses composite blends of Portland cement and other inorganic cementitious material such as blastfurnace slag and pulverised fuel ash to encapsulate or immobilise intermediate and low level radioactive wastes. Typically levels up 9:1 blast furnace slag:Portland cement or 4:1 pulverised fuel ash:Portland cement are used. Whilst these systems offer many advantages, their high pH causes corrosion of various metallic intermediate level radioactive wastes. To address this issue, lower pH/weakly alkaline cementitious systems have to be explored. While the blast furnace slag:Portland cement system is referred to as a composite cement system, the underlying reaction is actually an indirect activation of the slag hydration by the calcium hydroxide generated by the cement hydration, and by the alkali ions and gypsum present in the cement. However, the slag also can be activated directly with activators, creating a system known as alkali-activated slag. Whilst these activators used are usually strongly alkaline, weakly alkaline and near neutral salts can also be used. In this paper, the potential for using weakly alkaline and near neutral salts to activate slag in this manner is reviewed and discussed, with particular emphasis placed on the immobilisation of reactive metallic nuclear wastes.

  13. Efficient Generation of Functional Hepatocytes From Human Embryonic Stem Cells and Induced Pluripotent Stem Cells by HNF4α Transduction

    OpenAIRE

    Takayama, Kazuo; Inamura, Mitsuru; Kawabata, Kenji; Katayama, Kazufumi; Higuchi, Maiko; Tashiro, Katsuhisa; Nonaka, Aki; Sakurai, Fuminori; Hayakawa, Takao; Kusuda Furue, Miho; Mizuguchi, Hiroyuki

    2012-01-01

    Hepatocyte-like cells from human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are expected to be a useful source of cells drug discovery. Although we recently reported that hepatic commitment is promoted by transduction of SOX17 and HEX into human ESC- and iPSC-derived cells, these hepatocyte-like cells were not sufficiently mature for drug screening. To promote hepatic maturation, we utilized transduction of the hepatocyte nuclear factor 4α (HNF4α) gene, which is kn...

  14. Preventing hepatocyte oxidative stress cytotoxicity with Mangifera indica L. extract (Vimang).

    Science.gov (United States)

    Remirez, Diadelis; Tafazoli, Shahrzad; Delgado, Rene; Harandi, Asghar A; O'Brien, Peter J

    2005-01-01

    Vimang is an aqueous extract of Mangifera indica used in Cuba to improve the quality of life in patients suffering from inflammatory diseases. In the present study we evaluated the effects of Vimang at preventing reactive oxygen species (ROS) formation and lipid peroxidation in intact isolated rat hepatocytes. Vimang at 20, 50 and 100 microg/ml inhibited hepatocyte ROS formation induced by glucose-glucose oxidase. Hepatocyte cytotoxicity and lipid peroxidation induced by cumene hydroperoxide was also inhibited by Vimang in a dose and time dependent manner at the same concentration. Vimang also inhibited superoxide radical formation by xanthine oxidase and hypoxanthine. The superoxide radical scavenging and antioxidant activity of the Vimang extract was likely related to its gallates, catechins and mangiferin content. To our knowledge, this is the first report of cytoprotective antioxidant effects of Vimang in cellular oxidative stress models.

  15. Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes

    International Nuclear Information System (INIS)

    Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

    2003-01-01

    The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1α (HNF1α) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis

  16. Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes.

    Science.gov (United States)

    Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

    2003-09-01

    The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1alpha (HNF1alpha) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis.

  17. Results of Koo measurements of HTGR lattice by oscillated zero reactivity technique using the AGIP-NUCLEARE RB-2 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Benedetti, F; Brighenti, G.; Chiodi, P. L.; Ghilardotti, G.; Giuliani, C.

    1974-10-15

    This paper describes k-infinity measurements conducted using an assembly of loose HTGR coated particles in the BR-2 reactor by means of null reactivity oscillating method comparing the effect of poisoned and unpoisoned lattices like tests performed in the Physical Constants Test Reactor (PCTR) at Hanford. The RB-2 reactor was the property of the Italian firm AGIP NUCLEARE and operated at the Montecuccolino Center in Bologna.

  18. Endothelial cell-derived matrix promotes the metabolic functional maturation of hepatocyte via integrin-Src signalling.

    Science.gov (United States)

    Guo, Xinyue; Li, Weihong; Ma, Minghui; Lu, Xin; Zhang, Haiyan

    2017-11-01

    The extracellular matrix (ECM) microenvironment is involved in the regulation of hepatocyte phenotype and function. Recently, the cell-derived extracellular matrix has been proposed to represent the bioactive and biocompatible materials of the native ECM. Here, we show that the endothelial cell-derived matrix (EC matrix) promotes the metabolic maturation of human adipose stem cell-derived hepatocyte-like cells (hASC-HLCs) through the activation of the transcription factor forkhead box protein A2 (FOXA2) and the nuclear receptors hepatocyte nuclear factor 4 alpha (HNF4α) and pregnane X receptor (PXR). Reducing the fibronectin content in the EC matrix or silencing the expression of α5 integrin in the hASC-HLCs inhibited the effect of the EC matrix on Src phosphorylation and hepatocyte maturation. The inhibition of Src phosphorylation using the inhibitor PP2 or silencing the expression of Src in hASC-HLCs also attenuated the up-regulation of the metabolic function of hASC-HLCs in a nuclear receptor-dependent manner. These data elucidate integrin-Src signalling linking the extrinsic EC matrix signals and metabolic functional maturation of hepatocyte. This study provides a model for studying the interaction between hepatocytes and non-parenchymal cell-derived matrix. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  19. Generation of human hepatocytes by stem cell technology: definition of the hepatocyte.

    Science.gov (United States)

    Hengstler, Jan G; Brulport, Marc; Schormann, Wiebke; Bauer, Alexander; Hermes, Matthias; Nussler, Andreas K; Fandrich, Fred; Ruhnke, Maren; Ungefroren, Hendrik; Griffin, Louise; Bockamp, Ernesto; Oesch, Franz; von Mach, Marc-Alexander

    2005-06-01

    Since 1999, numerous articles have reported the generation of hepatocytes from different types of extrahepatic stem or precursor cells. This opens exciting new possibilities for pharmacology and toxicology, as well as for cell therapy. Hepatocyte marker expression, including albumin, cytokeratin 18, c-met, alpha-fetoprotein and cytochrome P450 3A4 and -2B6, has been observed after transplantation of different types of human stem cells into the liver of laboratory animals or in vitro after incubation with cytokines. These intriguing observations have prompted scientists to classify stem cell-derived cell populations as hepatocytes. However, this conclusion may be premature. It has been shown that factors of the liver microenvironment can induce expression of a limited number of hepatocyte marker genes in nonhepatic cell types. To conclude on the grounds of a limited number of markers that these cells are true hepatocytes is not indicated. In this case one should carefully evaluate crucial hepatocyte-defining enzymatic properties. The present article: i) reviews studies describing the fate of extrahepatic human stem and precursor cells in livers of laboratory animals, including the possibility of cell fusion; and ii) critically discusses the phenotype of stem cells after application of various differentiation protocols aimed at generating human hepatocytes. In addition, the necessary criteria needed for defining a true hepatocyte are suggested. Establishing the necessary properties for stem cell-derived hepatocytes is timely and reasonable, and thus avoids further misleading semantic confusion. Finally, it is essential to understand that the definition of a bona fide hepatocyte should not be limited to qualitative assays, such as reverse transcriptase polymerase chain reaction and immunohistochemistry, but has to include a quantitative analysis of enzymatic activities, which allows direct comparison with primary hepatocytes. Although the stem cell-derived-hepatocyte

  20. Comparison of the biological features between human fetal hepatocyte and immortalized L-02 hepatocyte in vitro

    International Nuclear Information System (INIS)

    Kong Weiwei; Teng Gaojun

    2004-01-01

    Objective: To evaluate the feasibilities of the potential donors in liver cell transplantation using the human fetal hepatocytes and immortalized L-02 hepatocytes by comparing their biological features. Methods: Human fetal hepatocytes were isolated from aborted fetal livers (gestational ages from 14 w to 24 w) by an improved two-stage perfusion method and cultured in a conditioned medium without any growth factors. α-fetal protein (AFP) and albumin (ALB) were detected by radioimmunoassay (RIA) and cytokeratin-19 (CK-19 ) was identified by cellular immunochemistry study. Immortalized L-02 hepatocytes were cultured in the same condition and the characteristic proteins were detected by the same methods. Results: The viability of human fetal hepatocytes was approximately 95% using the perfusion method, and the maximum survival time of the cultured hepatocytes was 3 weeks. The expression of AFP, ALB, and CK19 was detected at the same time, especially during Day 3 to Day 7 in the culture. By comparison, the proliferation ability of L-02 hepatocyte was greater, although with a lower level of ALB secretion. The expression of AFP and CK19 was not detected. Furthermore, during the long culture, L-02 hepatocytes may undergo a morphologic change and fail to express ALB. Conclusion: Human fetal hepatocyte may be a practical donor for hepatocyte transplantation with its high-level protein expression and potential bi-differentiation ability. In view of the absent expression of ALB and the morphologic change in culture, although with better proliferation, L-02 hepatocyte seems not useful for hepatocyte transplantation

  1. Lignans from Opuntia ficus-indica seeds protect rat primary hepatocytes and HepG2 cells against ethanol-induced oxidative stress.

    Science.gov (United States)

    Kim, Jung Wha; Yang, Heejung; Kim, Hyeon Woo; Kim, Hong Pyo; Sung, Sang Hyun

    2017-01-01

    Bioactivity-guided isolation of Opuntia ficus-indica (Cactaceae) seeds against ethanol-treated primary rat hepatocytes yielded six lignan compounds. Among the isolates, furofuran lignans 4-6, significantly protected rat hepatocytes against ethanol-induced oxidative stress by reducing intracellular reactive oxygen species levels, preserving antioxidative defense enzyme activities, and maintaining the glutathione content. Moreover, 4 dose-dependently induced the heme oxygenase-1 expression in HepG2 cells.

  2. Superoxide anions and hydrogen peroxide induce hepatocyte death by different mechanisms : Involvement of JNK and ERK MAP kinases

    NARCIS (Netherlands)

    Conde de la Rosa, L; Schoemaker, MH; Vrenken, TE; Buist-Homan, M; Havinga, R; Jansen, PLM; Moshage, H

    Background/Aims: In liver diseases, reactive oxygen species (ROS) are involved in cell death and liver injury, but the mechanisms are not completely elucidated. To elucidate the mechanisms of hepatocyte cell death induced by the ROS superoxide anions and hydrogen peroxide, primary cultures of

  3. Superoxide anions and hydrogen peroxide induce hepatocyte death by different mechanisms: involvement of JNK and ERK MAP kinases

    NARCIS (Netherlands)

    Conde de la Rosa, Laura; Schoemaker, Marieke H.; Vrenken, Titia E.; Buist-Homan, Manon; Havinga, Rick; Jansen, Peter L. M.; Moshage, Han

    2006-01-01

    BACKGROUND/AIMS: In liver diseases, reactive oxygen species (ROS) are involved in cell death and liver injury, but the mechanisms are not completely elucidated. To elucidate the mechanisms of hepatocyte cell death induced by the ROS superoxide anions and hydrogen peroxide, primary cultures of

  4. Development of a standard data base for FBR core nuclear design (XIII). Analysis of small sample reactivity experiments at ZPPR-9

    International Nuclear Information System (INIS)

    Sato, Wakaei; Fukushima, Manabu; Ishikawa, Makoto

    2000-09-01

    A comprehensive study to evaluate and accumulate the abundant results of fast reactor physics is now in progress at O-arai Engineering Center to improve analytical methods and prediction accuracy of nuclear design for large fast breeder cores such as future commercial FBRs. The present report summarizes the analytical results of sample reactivity experiments at ZPPR-9 core, which has not been evaluated by the latest analytical method yet. The intention of the work is to extend and further generalize the standard data base for FBR core nuclear design. The analytical results of the sample reactivity experiments (samples: PU-30, U-6, DU-6, SS-1 and B-1) at ZPPR-9 core in JUPITER series, with the latest nuclear data library JENDL-3.2 and the analytical method which was established by the JUPITER analysis, can be concluded as follows: The region-averaged final C/E values generally agreed with unity within 5% differences at the inner core region. However, the C/E values of every sample showed the radial space-dependency increasing from center to core edge, especially the discrepancy of B-1 was the largest by 10%. Next, the influence of the present analytical results for the ZPPR-9 sample reactivity to the cross-section adjustment was evaluated. The reference case was a unified cross-section set ADJ98 based on the recent JUPITER analysis. As a conclusion, the present analytical results have sufficient physical consistency with other JUPITER data, and possess qualification as a part of the standard data base for FBR nuclear design. (author)

  5. Whole-body X-irradiation of mice accelerates polyploidization of hepatocytes

    International Nuclear Information System (INIS)

    Shima, A.; Egami, N.

    1985-01-01

    Male C57BL/6 mice were whole-body irradiated with 4.75 gy of X-rays at the age of 2 months and killed at 2, 6, 12 and 19 months after irradiation. The percentage survival began to decline earlier and faster in the irradiated group than the controls up to 19 months after exposure when the study was terminated. The nuclear DNA content of individual hepatocytes was measured by a Feulgen-DNA microfluorometric method, and hepatocytes were classified into various ploidy classes. In the irradiated mice, the degree of polyploidization was significantly higher than the controls by 2 months after exposure and steadily increased up to 6 months after exposure. Thereafter, however, a slow return to the control level was found up to 19 months after irradiation. These results appear to support a hypothesis that radiation accelerates the ageing process as judged from hepatocyte polyploidization. (author)

  6. Cross-interference of two model peroxisome proliferators in peroxisomal and estrogenic pathways in brown trout hepatocytes.

    Science.gov (United States)

    Madureira, Tânia Vieira; Pinheiro, Ivone; Malhão, Fernanda; Lopes, Célia; Urbatzka, Ralph; Castro, L Filipe C; Rocha, Eduardo

    2017-06-01

    Peroxisome proliferators cause species-specific effects, which seem to be primarily transduced by peroxisome proliferator-activated receptor alpha (PPARα). Interestingly, PPARα has a close interrelationship with estrogenic signaling, and this latter has already been promptly activated in brown trout primary hepatocytes. Thus, and further exploring this model, we assess here the reactivity of two PPARα agonists in direct peroxisomal routes and, in parallel the cross-interferences in estrogen receptor (ER) mediated paths. To achieve these goals, three independent in vitro studies were performed using single exposures to clofibrate - CLF (50, 500 and 1000μM), Wy-14,643 - Wy (50 and 150μM), GW6471 - GW (1 and 10μM), and mixtures, including PPARα agonist or antagonist plus an ER agonist or antagonist. Endpoints included gene expression analysis of peroxisome/lipidic related genes (encoding apolipoprotein AI - ApoAI, fatty acid binding protein 1 - Fabp1, catalase - Cat, 17 beta-hydroxysteroid dehydrogenase 4 - 17β-HSD4, peroxin 11 alpha - Pex11α, PPARαBb, PPARαBa and urate oxidase - Uox) and those encoding estrogenic targets (ERα, ERβ-1 and vitellogenin A - VtgA). A quantitative morphological approach by using a pre-validated catalase immunofluorescence technique allowed checking possible changes in peroxisomes. Our results show a low responsiveness of trout hepatocytes to model PPARα agonists in direct target receptor pathways. Additionally, we unveiled interferences in estrogenic signaling caused by Wy, leading to an up-regulation VtgA and ERα at 150μM; these effects seem counteracted with a co-exposure to an ER antagonist. The present data stress the potential of this in vitro model for further exploring the physiological/toxicological implications related with this nuclear receptor cross-regulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Computation, measurement and analysis of the reactivity-to-power-transfer-function for the sodium cooled nuclear power plant KNK I

    International Nuclear Information System (INIS)

    Hoppe, P.; Mitzel, F.

    1977-02-01

    The Reactivity-to-Power-Transfer-Function for the sodium cooled nuclear power plant KNK I (Kompakte Natriumgekuehlte Kernenergieanlage) has been measured and compared with theoretical results. The measurements have been performed with the help of pseudostochastic reactivity perturbations. The transfer function has been determined by computing the auto- and cross-power-spectral-densities for the reactivity- and neutron flux signals. The agreement between the experimental and theoretical transfer function could be improved by adjusting the reactivity coefficients. The applications of these measurements with respect to reactor diagnosis and malfunction detection are discussed. For this purpose the accuracy of the measured transfer function is of great importance. Therefore an extensive error analysis has been performed. It turned out, that the inherent instability of the reactor without control system and the feedback by the primary coolant system were the reasons for comparatively big systematical errors. The conditions have been derived under which these types of errors can be considerably reduced. The conclusions can also be applied to analogical measurements at fast sodium cooled reactors. Because of their inherent stability the systematical errors will be reduced. (orig.) [de

  8. Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

    International Nuclear Information System (INIS)

    Liu, Cong; Sekine, Shuichi; Ito, Kousei

    2016-01-01

    Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.

  9. Cell proliferation studies in rodent hepatocytes during 1,4-dichlorobenzene administration

    International Nuclear Information System (INIS)

    Eldridge, S.R.; Tilbury, L.F.; Randall, H.; Goldsworthy, T.L.; Butterworth, B.E.

    1990-01-01

    In the NTP bioassay, 1,4-dichlorobenzene (DCB) induced hepatocellular carcinomas in mice, but not in rats. Because DCB is not DNA reactive, a cell proliferation study under conditions of the bioassay was undertaken to determine whether increased cell proliferation might play a role in DCB-induced hepatocarcinogenicity. DCB was administered in corn oil by gavage at the highest bioassay dose to male B6C3F1 mice (600 mg/kg) and male F344 rats (300 mg/kg) for five consecutive days. Cell proliferation was detected by labeling hepatocytes with either 5-bromo-2'-deoxyuridine (BRDU) or 3 H-thymidine delivered during the entire treatment period by subcutaneously implanted osmotic pumps. An increase in liver weight as a percentage of body weight was observed in treated mice (6.7±0.6 vs. 5.9±0.2) and rats (4.7±0.1 vs. 4.0±0.2) compared to controls. No significant elevations in plasma enzymes were found in either treated species, indicating a lack of overt hepatotoxicity. Histopathological evaluation revealed no evidence of hepatotoxicity in either species. The percentage of hepatocytes in S-phase was increased approximately 10-fold in both treated mice and rats compared to the respective control animals. Mice exhibited a centrilobular pattern of labeled hepatocytes, whereas rat hepatocytes were labeled hepatocytes, whereas rat hepatocytes were labeled throughout the lobules. These data demonstrate the hepatic mitogenic activity of DCB in mice and rats. However, this response dose not correlate with DCB-induced hepatocarcinogenicity. Further studies are required to examine the extent, duration and nature of the proliferative response in order to understand the species-specific effects of DCB

  10. Titanium Dioxide Nanoparticles Trigger Loss of Function and Perturbation of Mitochondrial Dynamics in Primary Hepatocytes.

    Directory of Open Access Journals (Sweden)

    Vaishaali Natarajan

    Full Text Available Titanium dioxide (TiO2 nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO2, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO2 coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO2 nanoparticles (commercially available rutile, anatase and P25 on primary rat hepatocytes. Specifically, we evaluated events related to hepatocyte functions and mitochondrial dynamics: (1 urea and albumin synthesis using colorimetric and ELISA assays, respectively; (2 redox signaling mechanisms by measuring reactive oxygen species (ROS production, manganese superoxide dismutase (MnSOD activity and mitochondrial membrane potential (MMP; (3 OPA1 and Mfn-1 expression that mediates the mitochondrial dynamics by PCR; and (4 mitochondrial morphology by MitoTracker Green FM staining. All three TiO2 nanoparticles induced a significant loss (p < 0.05 in hepatocyte functions even at concentrations as low as 50 ppm with commercially used P25 causing maximum damage. TiO2 nanoparticles induced a strong oxidative stress in primary hepatocytes. TiO2 nanoparticles exposure also resulted in morphological changes in mitochondria and substantial loss in the fusion process, thus impairing the mitochondrial dynamics. Although this study demonstrated that TiO2 nanoparticles exposure resulted in substantial damage to primary hepatocytes, more in vitro and in vivo studies are required to determine the complete toxicological mechanism in primary hepatocytes and subsequently liver function.

  11. Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cong; Sekine, Shuichi, E-mail: ssekine@faculty.chiba-u.jp; Ito, Kousei

    2016-07-01

    Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.

  12. BN600 reactivity definition

    International Nuclear Information System (INIS)

    Zheltyshev, V.; Ivanov, A.

    2000-01-01

    Since 1980, the fast BN600 reactor with sodium coolant has been operated at Beloyarsk Nuclear Power Plant. The periodic monitoring of the reactivity modifications should be implemented in compliance with the standards and regulations applied in nuclear power engineering. The reactivity measurements are carried out in order to confirm the basic neutronic features of a BN600 reactor. The reactivity measurements are aimed to justify that nuclear safety is provided in course of the in-reactor installation of the experimental core components. Two reactivity meters are to be used on BN600 operation: 1. Digital on-line reactivity calculated under stationary reactor operation on power (approximation of the point-wise kinetics is applied). 2. Second reactivity meter used to define the reactor control rod operating components efficiency under reactor startup and take account of the changing efficiency of the sensor, however, this is more time-consumptive than the on-line reactivity meter. The application of two reactivity meters allows for the monitoring of the reactor reactivity under every operating mode. (authors)

  13. Insulin-like growth factor-II receptors in cultured rat hepatocytes: regulation by cell density

    International Nuclear Information System (INIS)

    Scott, C.D.; Baxter, R.C.

    1987-01-01

    Insulin-like growth factor-II (IGF-II) receptors in primary cultures of adult rat hepatocytes were characterized and their regulation by cell density examined. In hepatocytes cultured at 5 X 10(5) cells per 3.8 cm2 plate [ 125 I]IGF-II bound to specific, high affinity receptors (Ka = 4.4 +/- 0.5 X 10(9) l/mol). Less than 1% cross-reactivity by IGF-I and no cross-reactivity by insulin were observed. IGF-II binding increased when cells were permeabilized with 0.01% digitonin, suggesting the presence of an intracellular receptor pool. Determined by Scatchard analysis and by polyacrylamide gel electrophoresis after affinity labeling, the higher binding was due solely to an increase in binding sites present on 220 kDa type II IGF receptors. In hepatocytes cultured at low densities, the number of cell surface receptors increased markedly, from 10-20,000 receptors per cell at a culture density of 6 X 10(5) cells/well to 70-80,000 receptors per cell at 0.38 X 10(5) cells/well. The increase was not due simply to the exposure of receptors from the intracellular pool, as a density-related increase in receptors was also seen in cells permeabilized with digitonin. There was no evidence that IGF binding proteins, either secreted by hepatocytes or present in fetal calf serum, had any effect on the measurement of receptor concentration or affinity. We conclude that rat hepatocytes in primary culture contain specific IGF-II receptors and that both cell surface and intracellular receptors are regulated by cell density

  14. Cross-interference of two model peroxisome proliferators in peroxisomal and estrogenic pathways in brown trout hepatocytes

    International Nuclear Information System (INIS)

    Madureira, Tânia Vieira; Pinheiro, Ivone; Malhão, Fernanda; Lopes, Célia; Urbatzka, Ralph; Castro, L. Filipe C.

    2017-01-01

    Highlights: • Brown trout hepatocytes seem to be a low responder to model peroxisome proliferators. • Most peroxisomal targets were not affected by Wy-14,643 and clofibrate exposures. • Some estrogenic-related genes were up-regulated after 150 μM of Wy-14,643. • Wy-14,643 increase VtgA and ERα mRNA levels, while ICI 182,780 revert the effect. • Cross-interference in peroxisomal and estrogenic pathways should be more explored. - Abstract: Peroxisome proliferators cause species-specific effects, which seem to be primarily transduced by peroxisome proliferator-activated receptor alpha (PPARα). Interestingly, PPARα has a close interrelationship with estrogenic signaling, and this latter has already been promptly activated in brown trout primary hepatocytes. Thus, and further exploring this model, we assess here the reactivity of two PPARα agonists in direct peroxisomal routes and, in parallel the cross-interferences in estrogen receptor (ER) mediated paths. To achieve these goals, three independent in vitro studies were performed using single exposures to clofibrate – CLF (50, 500 and 1000 μM), Wy-14,643 – Wy (50 and 150 μM), GW6471 – GW (1 and 10 μM), and mixtures, including PPARα agonist or antagonist plus an ER agonist or antagonist. Endpoints included gene expression analysis of peroxisome/lipidic related genes (encoding apolipoprotein AI – ApoAI, fatty acid binding protein 1 – Fabp1, catalase – Cat, 17 beta-hydroxysteroid dehydrogenase 4 – 17β-HSD4, peroxin 11 alpha – Pex11α, PPARαBb, PPARαBa and urate oxidase – Uox) and those encoding estrogenic targets (ERα, ERβ-1 and vitellogenin A – VtgA). A quantitative morphological approach by using a pre-validated catalase immunofluorescence technique allowed checking possible changes in peroxisomes. Our results show a low responsiveness of trout hepatocytes to model PPARα agonists in direct target receptor pathways. Additionally, we unveiled interferences in estrogenic

  15. Cross-interference of two model peroxisome proliferators in peroxisomal and estrogenic pathways in brown trout hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Madureira, Tânia Vieira, E-mail: tvmadureira@icbas.up.pt [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos (Portugal); Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto (Portugal); Pinheiro, Ivone; Malhão, Fernanda; Lopes, Célia [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos (Portugal); Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (U. Porto), Laboratory of Histology and Embryology, Department of Microscopy, Rua Jorge Viterbo Ferreira 228, P 4050-313 Porto (Portugal); Urbatzka, Ralph [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos (Portugal); Castro, L. Filipe C. [Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto (U. Porto), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos (Portugal); Faculty of Sciences (FCUP), University of Porto (U. Porto), Department of Biology, Rua do Campo Alegre, P 4169-007 Porto (Portugal); and others

    2017-06-15

    Highlights: • Brown trout hepatocytes seem to be a low responder to model peroxisome proliferators. • Most peroxisomal targets were not affected by Wy-14,643 and clofibrate exposures. • Some estrogenic-related genes were up-regulated after 150 μM of Wy-14,643. • Wy-14,643 increase VtgA and ERα mRNA levels, while ICI 182,780 revert the effect. • Cross-interference in peroxisomal and estrogenic pathways should be more explored. - Abstract: Peroxisome proliferators cause species-specific effects, which seem to be primarily transduced by peroxisome proliferator-activated receptor alpha (PPARα). Interestingly, PPARα has a close interrelationship with estrogenic signaling, and this latter has already been promptly activated in brown trout primary hepatocytes. Thus, and further exploring this model, we assess here the reactivity of two PPARα agonists in direct peroxisomal routes and, in parallel the cross-interferences in estrogen receptor (ER) mediated paths. To achieve these goals, three independent in vitro studies were performed using single exposures to clofibrate – CLF (50, 500 and 1000 μM), Wy-14,643 – Wy (50 and 150 μM), GW6471 – GW (1 and 10 μM), and mixtures, including PPARα agonist or antagonist plus an ER agonist or antagonist. Endpoints included gene expression analysis of peroxisome/lipidic related genes (encoding apolipoprotein AI – ApoAI, fatty acid binding protein 1 – Fabp1, catalase – Cat, 17 beta-hydroxysteroid dehydrogenase 4 – 17β-HSD4, peroxin 11 alpha – Pex11α, PPARαBb, PPARαBa and urate oxidase – Uox) and those encoding estrogenic targets (ERα, ERβ-1 and vitellogenin A – VtgA). A quantitative morphological approach by using a pre-validated catalase immunofluorescence technique allowed checking possible changes in peroxisomes. Our results show a low responsiveness of trout hepatocytes to model PPARα agonists in direct target receptor pathways. Additionally, we unveiled interferences in estrogenic

  16. Transcriptome of extracellular vesicles released by hepatocytes.

    Directory of Open Access Journals (Sweden)

    Felix Royo

    Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

  17. Activated Hepatic Stellate Cells Induce Tumor Progression of Neoplastic Hepatocytes in a TGF-β Dependent Fashion

    Science.gov (United States)

    MIKULA, M.; PROELL, V.; FISCHER, A.N.M.; MIKULITS, W.

    2010-01-01

    The development of hepatocellular carcinomas from malignant hepatocytes is frequently associated with intra- and peritumoral accumulation of connective tissue arising from activated hepatic stellate cells. For both tumorigenesis and hepatic fibrogenesis, transforming growth factor (TGF)-β signaling executes key roles and therefore is considered as a hallmark of these pathological events. By employing cellular transplantation we show that the interaction of neoplastic MIM-R hepatocytes with the tumor microenvironment, containing either activated hepatic stellate cells (M1-4HSCs) or myofibroblasts derived thereof (M-HTs), induces progression in malignancy. Cotransplantation of MIM-R hepatocytes with M-HTs yielded strongest MIM-R generated tumor formation accompanied by nuclear localization of Smad2/3 as well as of β-catenin. Genetic interference with TGF-β signaling by gain of antagonistic Smad7 in MIM-R hepatocytes diminished epithelial dedifferentiation and tumor progression upon interaction with M1-4HSCs or M-HTs. Further analysis showed that tumors harboring disrupted Smad signaling are devoid of nuclear β-catenin accumulation, indicating a crosstalk between TGF-β and β-catenin signaling. Together, these data demonstrate that activated HSCs and myofibroblasts directly govern hepatocarcinogenesis in a TGF-β dependent fashion by inducing autocrine TGF-β signaling and nuclear β-catenin accumulation in neoplastic hepatocytes. These results indicate that intervention with TGF-β signaling is highly promising in liver cancer therapy. PMID:16883581

  18. The measurement of subcritical reactivity in nuclear reactors by use of a high frequency sine-wave modulated neutron source

    International Nuclear Information System (INIS)

    Guppy, C.B.

    1964-11-01

    In this report the frequency response characteristics for phase and gain of the fundamental reactor mode of the zero power kinetics are given for various subcritical reactivities in a fast reactor and in a thermal reactor. Results, of a study on harmonic effects based on a small zero energy thermal reactor are presented which demonstrate the importance of spatial harmonic effects. A harmonic theory for thermal reactors is developed. A new method of measuring, subcritical reactivity at moderately high frequencies is suggested which circumvents the harmonic problem. It is shown that at high frequencies there is more sensitivity than at low frequencies and that this could lead to an increased range over which subcritical reactivity can be measured. (author)

  19. Study of Valproic Acid-Enhanced Hepatocyte Steatosis

    Science.gov (United States)

    Chang, Renin; Chou, Mei-Chia; Hung, Li-Ying; Wang, Mu-En; Hsu, Meng-Chieh; Chiu, Chih-Hsien

    2016-01-01

    Valproic acid (VPA) is one of the most widely used antiepilepsy drugs. However, several side effects, including weight gain and fatty liver, have been reported in patients following VPA treatment. In this study, we explored the molecular mechanisms of VPA-induced hepatic steatosis using FL83B cell line-based in vitro model. Using fluorescent lipid staining technique, we found that VPA enhanced oleic acid- (OLA-) induced lipid accumulation in a dose-dependent manner in hepatocytes; this may be due to upregulated lipid uptake, triacylglycerol (TAG) synthesis, and lipid droplet formation. Real-time PCR results showed that, following VPA treatment, the expression levels of genes encoding cluster of differentiation 36 (Cd36), low-density lipoprotein receptor-related protein 1 (Lrp1), diacylglycerol acyltransferase 2 (Dgat2), and perilipin 2 (Plin2) were increased, that of carnitine palmitoyltransferase I a (Cpt1a) was not affected, and those of acetyl-Co A carboxylase α (Acca) and fatty acid synthase (Fasn) were decreased. Furthermore, using immunofluorescence staining and flow cytometry analyses, we found that VPA also induced peroxisome proliferator-activated receptor γ (PPARγ) nuclear translocation and increased levels of cell-surface CD36. Based on these results, we propose that VPA may enhance OLA-induced hepatocyte steatosis through the upregulation of PPARγ- and CD36-dependent lipid uptake, TAG synthesis, and lipid droplet formation. PMID:27034954

  20. Study of Valproic Acid-Enhanced Hepatocyte Steatosis

    Directory of Open Access Journals (Sweden)

    Renin Chang

    2016-01-01

    Full Text Available Valproic acid (VPA is one of the most widely used antiepilepsy drugs. However, several side effects, including weight gain and fatty liver, have been reported in patients following VPA treatment. In this study, we explored the molecular mechanisms of VPA-induced hepatic steatosis using FL83B cell line-based in vitro model. Using fluorescent lipid staining technique, we found that VPA enhanced oleic acid- (OLA- induced lipid accumulation in a dose-dependent manner in hepatocytes; this may be due to upregulated lipid uptake, triacylglycerol (TAG synthesis, and lipid droplet formation. Real-time PCR results showed that, following VPA treatment, the expression levels of genes encoding cluster of differentiation 36 (Cd36, low-density lipoprotein receptor-related protein 1 (Lrp1, diacylglycerol acyltransferase 2 (Dgat2, and perilipin 2 (Plin2 were increased, that of carnitine palmitoyltransferase I a (Cpt1a was not affected, and those of acetyl-Co A carboxylase α (Acca and fatty acid synthase (Fasn were decreased. Furthermore, using immunofluorescence staining and flow cytometry analyses, we found that VPA also induced peroxisome proliferator-activated receptor γ (PPARγ nuclear translocation and increased levels of cell-surface CD36. Based on these results, we propose that VPA may enhance OLA-induced hepatocyte steatosis through the upregulation of PPARγ- and CD36-dependent lipid uptake, TAG synthesis, and lipid droplet formation.

  1. Transport of heparan sulfate into the nuclei of hepatocytes

    International Nuclear Information System (INIS)

    Ishihara, M.; Fedarko, N.S.; Conrad, H.E.

    1986-01-01

    A rat hepatocyte cell line which accumulates free heparan sulfate (HS) chains enriched in GlcA-2-SO 4 residues in the nucleus was labeled with 35 SO 4 2- and the rate of appearance of [ 35 SO 4 ]HS in the nucleus was measured. [ 35 SO 4 ]HS began to accumulate in the nucleus 2 h after the addition of 35 SO 42- and reached a steady state level after 20 h. HS was lost from the nuclei of prelabeled cells with a t/sub 1/2/ of 8 h. Chloroquine did not inhibit the transport of HS into the nucleus, but increased the t/sub 1/2/ for the exit of HS from the nucleus to 20 h. At both 37 0 C and 16 0 C exogenous [ 35 SO 4 ]proteoHS was taken up by the cells and converted to free chains and about 10% of the internalized [ 35 SO 4 ]HS was transported into the nucleus. The [ 35 SO 4 ]HS isolated from the nucleus was enriched in GlcA-2-SO 4 residues, whereas the [ 35 SO 4 ]HS remaining in the rest of the intra-cellular pool showed a corresponding depletion in GlcA-2-SO 4 residues. The results show that nuclear HS is derived from the pool of a secreted proteoHS and that metabolism of exogenous HS by hepatocytes does not involve lysosomal processing of the internalized HS

  2. Long-term culture and expansion of primary human hepatocytes

    NARCIS (Netherlands)

    Levy, G.; Bomze, D.; Heinz, S.; Ramachandran, S.D.; Noerenberg, A.; Cohen, M.; Shibolet, O.; Sklan, E.; Braspenning, J.C.; Nahmias, Y.

    2015-01-01

    Hepatocytes have a critical role in metabolism, but their study is limited by the inability to expand primary hepatocytes in vitro while maintaining proliferative capacity and metabolic function. Here we describe the oncostatin M (OSM)-dependent expansion of primary human hepatocytes by low

  3. Renal medullary AA amyloidosis, hepatocyte dissociation and multinucleated hepatocytes in a 14-year-old free-ranging lioness (Panthera leo

    Directory of Open Access Journals (Sweden)

    J.H. Williams

    2005-06-01

    Full Text Available A 14-year-old lioness, originating from Etosha in Namibia, and a member of a pride in Pilanesberg National Park since translocation in 1994, was euthanased due to fight-related vertebral fracture and spinal injury, incurred approximately 6-8 weeks previously. Blood specimens collected at the time of death showed mild anaemia and a leukogram reflecting stress and chronic infection. Necropsy conducted within 2 hours of death was on a dehydrated, emaciated animal with hindquarter wasting and chronic traumatic friction injuries from dragging her hindlegs. There was cellulitis in the region of bite-wounds adjacent to the thoraco-lumbar vertebral fracture, at which site there was spinal cord compression, and there was marked intestinal helminthiasis. The outer renal medullae appeared pale and waxy and the liver was macroscopically unremarkable. Histopathology and electron microscopy of the kidneys revealed multifocal to coalescing deposits of proximal medullary interstitial amyloid, which fluoresced strongly with thioflavine T, and was sensitive to potassium permanganate treatment prior to Congo Red staining, thus indicating inflammatory (AA origin. There was diffuse hepatocyte dissociation, as well as numerous binucleated and scattered multinucleated (up to 8 nuclei/cell hepatocytes, with swollen hepatocyte mitochondria, in liver examined light microscopically. Ultrastructurally, the mono-, bi- and multinucleated hepatocytes contained multifocal irregular membrane-bound accumulations of finely-granular, amorphous material both intra-cytoplasmically and intra-nuclearly, as well as evidence of irreversible mitochondrial injury. The incidence and relevance in cats and other species of amyloidosis, particularly with renal medullary distribution, as well as of hepatocyte dissociation and multinucleation, as reported in selected literature, is briefly overviewed and their occurrence in this lioness is discussed.

  4. Swelling of rat hepatocytes stimulates glycogen synthesis

    NARCIS (Netherlands)

    Baquet, A.; Hue, L.; Meijer, A. J.; van Woerkom, G. M.; Plomp, P. J.

    1990-01-01

    In hepatocytes from fasted rats, several amino acids are known to stimulate glycogen synthesis via activation of glycogen synthase. The hypothesis that an increase in cell volume resulting from amino acid uptake may be involved in the stimulation of glycogen synthesis is supported by the following

  5. Impaired mitochondrial functions contribute to 3-bromopyruvate toxicity in primary rat and mouse hepatocytes.

    Science.gov (United States)

    Sobotka, Ondřej; Endlicher, René; Drahota, Zdeněk; Kučera, Otto; Rychtrmoc, David; Raad, Marjan; Hakeem, Khurum; Červinková, Zuzana

    2016-08-01

    A compound with promising anticancer properties, 3-bromopyruvate (3-BP) is a synthetic derivative of a pyruvate molecule; however, its toxicity in non-malignant cells has not yet been fully elucidated. Therefore, we elected to study the effects of 3-BP on primary hepatocytes in monolayer cultures, permeabilized hepatocytes and isolated mitochondria. After a 1-h treatment with 100 μM 3-BP cell viability of rat hepatocytes was decreased by 30 % as measured by the WST-1 test (p < 0.001); after 3-h exposure to ≥200 μM 3-BP lactate dehydrogenase leakage was increased (p < 0.001). Reactive oxygen species production was increased in the cell cultures after a 1-h treatment at concentrations ≥100 μmol/l (p < 0.01), and caspase 3 activity was increased after a 20-h incubation with 150 μM and 200 μM 3-BP (p < 0.001). This toxic effect of 3-BP was also proved using primary mouse hepatocytes. In isolated mitochondria, 3-BP induced a dose- and time-dependent decrease of mitochondrial membrane potential during a 10-min incubation both with Complex I substrates glutamate + malate or Complex II substrate succinate, although this decrease was more pronounced with the latter. We also measured the effect of 3-BP on respiration of isolated mitochondria. ADP-activated respiration was inhibited by 20 μM 3-BP within 10 min. Similar effects were also found in permeabilized hepatocytes of both species.

  6. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    Science.gov (United States)

    Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. PMID:23026831

  7. Cadmium-induced apoptosis through the mitochondrial pathway in rainbow trout hepatocytes: involvement of oxidative stress

    International Nuclear Information System (INIS)

    Risso-de Faverney, C.; Orsini, N.; Sousa, G. de; Rahmani, R.

    2004-01-01

    Cadmium (Cd) induces oxidative stress and apoptosis in trout hepatocytes. We therefore investigated the involvement of the mitochondrial pathway in the initiation of apoptosis and the possible role of oxidative stress in that process. This study demonstrates that hepatocyte exposure to Cd (2, 5 and 10 μM) triggers significant caspase-3, but also caspase-8 and -9 activation in a dose-dependent manner. Western-blot analysis of hepatocyte mitochondrial and cytosolic fractions revealed that cytochrome c (Cyt c) was released in the cytosol in a dose-dependent manner, whereas the pro-apoptotic protein Bax was redistributed to mitochondria after 24 and 48 h exposure. We also found that the expression of anti-apoptotic protein Bcl-xL, known to be regulated under mild oxidative stress to protect cells from apoptosis, did not change after 3 and 6 h exposure to Cd, then increased after 24 and 48 h exposure to 10 μM Cd. In the second part of this work, two antioxidant agents, 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) (100 μM) and N-acetylcysteine (NAC, 100 μM) were used to determine the involvement of reactive oxygen species (ROS) in Cd-induced apoptosis. Simultaneously exposing trout hepatocytes to Cd and TEMPO or NAC significantly reduced caspase-3 activation after 48 h and had a suppressive effect on caspase-8 and -9 also, mostly after 24 h. Lastly, the presence of either one of these antioxidants in the treatment medium also attenuated Cd-induced Cyt c release in cytosol and the level of Bax in the mitochondria after 24 and 48 h, while high Bcl-xL expression was observed. Taken together, these data clearly evidenced the key role of mitochondria in the cascade of events leading to trout hepatocyte apoptosis in response to Cd and the relationship that exists between oxidative stress and cell death

  8. Acylcarnitine Profiles in Acetaminophen Toxicity in the Mouse: Comparison to Toxicity, Metabolism and Hepatocyte Regeneration

    Directory of Open Access Journals (Sweden)

    Jack Hinson

    2013-08-01

    Full Text Available High doses of acetaminophen (APAP result in hepatotoxicity that involves metabolic activation of the parent compound, covalent binding of the reactive intermediate N-acetyl-p-benzoquinone imine (NAPQI to liver proteins, and depletion of hepatic glutathione. Impaired fatty acid β-oxidation has been implicated in previous studies of APAP-induced hepatotoxicity. To better understand relationships between toxicity and fatty acid β-oxidation in the liver in APAP toxicity, metabolomic assays for long chain acylcarnitines were examined in relationship to established markers of liver toxicity, oxidative metabolism, and liver regeneration in a time course study in mice. Male B6C3F1 mice were treated with APAP (200 mg/kg IP or saline and sacrificed at 1, 2, 4, 8, 24 or 48 h after APAP. At 1 h, hepatic glutathione was depleted and APAP protein adducts were markedly increased. Alanine aminotransferase (ALT levels were elevated at 4 and 8 h, while proliferating cell nuclear antigen (PCNA expression, indicative of hepatocyte regeneration, was apparent at 24 h and 48 h. Elevations of palmitoyl, oleoyl and myristoyl carnitine were apparent by 2–4 h, concurrent with the onset of Oil Red O staining in liver sections. By 8 h, acylcarnitine levels were below baseline levels and remained low at 24 and 48 h. A partial least squares (PLS model suggested a direct association of acylcarnitine accumulation in serum to APAP protein adduct and hepatic glutathione levels in mice. Overall, the kinetics of serum acylcarnitines in APAP toxicity in mice followed a biphasic pattern involving early elevation after the metabolism phases of toxicity and later depletion of acylcarnitines.

  9. Chronic alcohol feeding potentiates hormone-induced calcium signalling in hepatocytes.

    Science.gov (United States)

    Bartlett, Paula J; Antony, Anil Noronha; Agarwal, Amit; Hilly, Mauricette; Prince, Victoria L; Combettes, Laurent; Hoek, Jan B; Gaspers, Lawrence D

    2017-05-15

    Chronic alcohol consumption causes a spectrum of liver diseases, but the pathogenic mechanisms driving the onset and progression of disease are not clearly defined. We show that chronic alcohol feeding sensitizes rat hepatocytes to Ca 2+ -mobilizing hormones resulting in a leftward shift in the concentration-response relationship and the transition from oscillatory to more sustained and prolonged Ca 2+ increases. Our data demonstrate that alcohol-dependent adaptation in the Ca 2+ signalling pathway occurs at the level of hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) production and does not involve changes in the sensitivity of the IP 3 receptor or size of internal Ca 2+ stores. We suggest that prolonged and aberrant hormone-evoked Ca 2+ increases may stimulate the production of mitochondrial reactive oxygen species and contribute to alcohol-induced hepatocyte injury. ABSTRACT: 'Adaptive' responses of the liver to chronic alcohol consumption may underlie the development of cell and tissue injury. Alcohol administration can perturb multiple signalling pathways including phosphoinositide-dependent cytosolic calcium ([Ca 2+ ] i ) increases, which can adversely affect mitochondrial Ca 2+ levels, reactive oxygen species production and energy metabolism. Our data indicate that chronic alcohol feeding induces a leftward shift in the dose-response for Ca 2+ -mobilizing hormones resulting in more sustained and prolonged [Ca 2+ ] i increases in both cultured hepatocytes and hepatocytes within the intact perfused liver. Ca 2+ increases were initiated at lower hormone concentrations, and intercellular calcium wave propagation rates were faster in alcoholics compared to controls. Acute alcohol treatment (25 mm) completely inhibited hormone-induced calcium increases in control livers, but not after chronic alcohol-feeding, suggesting desensitization to the inhibitory actions of ethanol. Hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) accumulation and phospholipase C

  10. Digital reactivity meter

    International Nuclear Information System (INIS)

    Jiang Zongbing

    1996-02-01

    The importance and the usual methods of reactivity measurement in a nuclear reactor are presented. Emphasis is put upon the calculation principle, software and hardware components, main specifications, application, as well as the features of the digital reactivity meter. The test results of operation in various reactors shown that the meter possess the following features: high accuracy, short response time, low output noise, high resolution, wide measuring range, simple and flexible to operate, high stability and reliability. In addition, the reactivity meter can save the measuring data automatically and have a perfect capability of self-verifying. It not only meet the requirement of the reactivity measurement in nuclear power plant, but also can be applied to various types of reactors. (1 tab.)

  11. The Hepatitis B Virus (HBV) HBx Protein Activates AKT To Simultaneously Regulate HBV Replication and Hepatocyte Survival

    Science.gov (United States)

    Rawat, Siddhartha

    2014-01-01

    ABSTRACT Chronic infection with hepatitis B virus (HBV) is a risk factor for developing liver diseases such as hepatocellular carcinoma (HCC). HBx is a multifunctional protein encoded by the HBV genome; HBx stimulates HBV replication and is thought to play an important role in the development of HBV-associated HCC. HBx can activate the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in some cell lines; however, whether HBx regulates PI3K/AKT signaling in normal hepatocytes has not been evaluated. In studies described here, we assessed HBx activation of PI3K/AKT signaling in an ex vivo model of cultured primary hepatocytes and determined how this HBx activity affects HBV replication. We report that HBx activates AKT in primary hepatocytes and that the activation of AKT decreases HBV replication and HBV mRNA and core protein levels. We show that the transcription factor hepatocyte nuclear factor 4α (HNF4α) is a target of HBx-regulated AKT, and we link HNF4α to HBx-regulated AKT modulation of HBV transcription and replication. Although we and others have shown that HBx stimulates and is likely required for HBV replication, we now report that HBx also activates signals that can diminish the overall level of HBV replication. While this may seem counterintuitive, we show that an important effect of HBx activation of AKT is inhibition of apoptosis. Consequently, our studies suggest that HBx balances HBV replication and cell survival by stimulating signaling pathways that enhance hepatocyte survival at the expense of higher levels of HBV replication. IMPORTANCE Chronic hepatitis B virus (HBV) infection is a common cause of the development of liver cancer. Regulation of cell signaling pathways by the HBV HBx protein is thought to influence the development of HBV-associated liver cancer. HBx stimulates, and may be essential for, HBV replication. We show that HBx activates AKT in hepatocytes to reduce HBV replication. While this seems contradictory to an

  12. AUTOFLUORESCENCE IN PRIMARY RAINBOW TROUT HEPATOCYTES INTERFERES WITH MEASUREMENT OF OXIDATIVE ACTIVITY VIA THE EXOGENOUS PROBE, DCF, BUT PROVIDES INTRINSIC MEASURE OF CELLULAR OXIDATIVE STATE

    Science.gov (United States)

    The compound 2', 7'-dichlorodihydrofluoroscein diacetate is a probe commonly used to detect oxidative activity in live cells. Studies were undertaken to measure reactive oxygen species generated in freshly isolated rainbow trout hepatocytes exposed to a variety of redox cycling c...

  13. Tributyltin induces apoptotic signaling in hepatocytes through pathways involving the endoplasmic reticulum and mitochondria

    International Nuclear Information System (INIS)

    Grondin, Melanie; Marion, Michel; Denizeau, Francine; Averill-Bates, Diana A.

    2007-01-01

    Tri-n-butyltin is a widespread environmental toxicant, which accumulates in the liver. This study investigates whether tri-n-butyltin induces pro-apoptotic signaling in rat liver hepatocytes through pathways involving the endoplasmic reticulum and mitochondria. Tri-n-butyltin activated the endoplasmic reticulum pathway of apoptosis, which was demonstrated by the activation of the protease calpain, its translocation to the plasma membrane, followed by cleavage of the calpain substrates, cytoskeletal protein vinculin, and caspase-12. Caspase-12 is localized to the cytoplasmic side of the endoplasmic reticulum and is involved in apoptosis mediated by the endoplasmic reticulum. Tri-n-butyltin also caused translocation of the pro-apoptotic proteins Bax and Bad from the cytosol to mitochondria, as well as changes in mitochondrial membrane permeability, events which can activate the mitochondrial death pathway. Tri-n-butyltin induced downstream apoptotic events in rat hepatocytes at the nuclear level, detected by chromatin condensation and by confocal microscopy using acridine orange. We investigated whether the tri-n-butyltin-induced pro-apoptotic events in hepatocytes could be linked to perturbation of intracellular calcium homeostasis, using confocal microscopy. Tri-n-butyltin caused changes in intracellular calcium distribution, which were similar to those induced by thapsigargin. Calcium was released from a subcellular compartment, which is likely to be the endoplasmic reticulum, into the cytosol. Cytosolic acidification, which is known to trigger apoptosis, also occurred and involved the Cl - /HCO 3 - exchanger. Pro-apoptotic events in hepatocytes were inhibited by the calcium chelator, Bapta-AM, and by a calpain inhibitor, which suggests that changes in intracellular calcium homeostasis are involved in tri-n-butyltin-induced apoptotic signaling in rat hepatocytes

  14. Metabolism of lipoproteins by human fetal hepatocytes

    International Nuclear Information System (INIS)

    Carr, B.R.

    1987-01-01

    The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [ 125 I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [ 125 I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues

  15. Boron and Tin in Nuclear Medicine: The Development of Reactive Solid-State Reagents for use in PET and SPECT. Final Report

    International Nuclear Information System (INIS)

    George W. Kabalka

    2006-01-01

    The research program was directed at the use of functionalized organometallic reagents that would rapidly react with radiolabeled agents generated by a medical cyclotron or reactor. The radioisotopes included fluorine-18, oxygen-15, nitrogen-13, carbon-11 and iodine-123; all short lived nuclides of importance in nuclear medicine imaging studies utilizing emission tomography techniques. The early studies led to the development of extensive new isotope incorporation chemistry. These studies validated the feasibility of using reactive intermediates, such as the organoboranes, and acted as a catalyst for others to investigate organometallic agents based on mercury, tin, and silicon. A large number of radiolabeling techniques and radiopharmaceuticals were developed. These included agents for use in oncology, neurology, and metabolism. The research resulted in the generation of one hundred and one journal articles, eighty seven refereed published abstracts and forty one invited lectures. Thirteen postdoctoral students, fourteen graduate students, and twenty eight undergraduate students were trained in the scientific aspects of nuclear medicine imaging under the auspices of this grant

  16. Final Report for "Boron and Tin in Nuclear Medicien: The Development of Reactive Solid-State Reagents for PET and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    George W. Kabalka

    2006-01-13

    The research program was directed at the use of functionalized organometallic reagents that would rapidly react with radiolabeled agents generated by a medical cyclotron or reactor. The radioisotopes included fluorine-18, oxgygen-15, nitrogen-13, carbon-11 and iodine-123; all short lived nuclides of importantce in nuclear medicine imaging studies utilizing emission tomography techniques. The early studies led to the development of extensive new isotope incorporation chemistry. These studies validated the feasibility of using reactive intermediates, such as the organoboranes, and acted as a catalyst for others to investigate organometallic agents based on mercury, tin, and silicon. A large number of radiolabeling techniques and radiopharmaceuticals were developed. These included agents for use in oncology, neurology, and metabolism. The research resulted in the generation of one hundred and one journal articles, eighty seven refereed published abstracts and forty one invited lectures. Thirteen postdoctoral students, fourteen graduate students, and twenty eight undergraduate students were trained in the scientific aspects of nuclear medicine imaging under the asupices of this grant.

  17. Induction of highly functional hepatocytes from human umbilical cord mesenchymal stem cells by HNF4α transduction.

    Directory of Open Access Journals (Sweden)

    Hualian Hang

    Full Text Available To investigate the differentiation potential of human umbilical mesenchymal stem cells (HuMSCs and the key factors that facilitate hepatic differentiation.HuMSCs were induced to become hepatocyte-like cells according to a previously published protocol. The differentiation status of the hepatocyte-like cells was examined by observing the morphological changes under an inverted microscope and by immunofluorescence analysis. Hepatocyte nuclear factor 4 alpha (HNF4α overexpression was achieved by plasmid transfection of the hepatocyte-like cells. The expression of proteins and genes of interest was then examined by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR or real-time RT-PCR methods.Our results demonstrated that HuMSCs can easily be induced into hepatocyte-like cells using a published differentiation protocol. The overexpression of HNF4α in the induced HuMSCs significantly enhanced the expression levels of hepatic-specific proteins and genes. HNF4α overexpression may be associated with liver-enriched transcription factor networks and the Wnt/β-Catenin pathway.The overexpression of HNF4α improves the hepatic differentiation of HuMSCs and is a simple way to improve cellular sources for clinical applications.

  18. Inhibition of hepatocyte gap junctional intercellular communication by tumor promoters

    International Nuclear Information System (INIS)

    Ruch, R.J.

    1988-01-01

    The mechanisms by which tumor promoters enhance neoplasia are poorly understood. One effect common to most tumor promoters is their ability to inhibit the cell-to-cell exchange of small molecules and ions through gap junctions, i.e., gap junctional intercellular communication (IC). IC maybe necessary for normal growth control and the loss of IC may predispose cells to enhanced growth. In the present studies, the effects of liver tumor promoters and other agents on IC between rodent hepatocytes in primary culture has been studied. IC was detected between hepatocytes: (1) autoradiographically following the passage and incorporation of [5- 3 H]uridine nucleotides from pre-labeled donor hepatocytes to non-labeled, adjacent recipient hepatocytes and (2) by fluorescence microscopy after microinjection of fluorescent Lucifer Yellow CH dye into hepatocytes and visualizing dye spread into adjacent hepatocytes

  19. Hepatocyte heterogeneity in the metabolism of carbohydrates.

    Science.gov (United States)

    Jungermann, K; Thurman, R G

    1992-01-01

    Periportal and perivenous hepatocytes possess different amounts and activities of the rate-generating enzymes of carbohydrate and oxidative energy metabolism and thus different metabolic capacities. This is the basis of the model of metabolic zonation, according to which periportal cells catalyze predominantly the oxidative catabolism of fatty and amino acids as well as glucose release and glycogen formation via gluconeogenesis, and perivenous cells carry out preferentially glucose uptake for glycogen synthesis and glycolysis coupled to liponeogenesis. The input of humoral and nervous signals into the periportal and perivenous zones is different; gradients of oxygen, substrates and products, hormones and mediators and nerve densities exist which are important not only for the short-term regulation of carbohydrate metabolism but also for the long-term regulation of zonal gene expression. The specialization of periportal and perivenous hepatocytes in carbohydrate metabolism has been well characterized. In vivo evidence is provided by the complex metabolic situation termed the 'glucose paradox' and by zonal flux differences calculated on the basis of the distribution of enzymes and metabolites. In vitro evidence is given by the different flux rates determined with classical invasive techniques, e.g. in periportal-like and perivenous-like hepatocytes in cell culture, in periportal- and perivenous-enriched hepatocyte populations and in perfused livers during orthograde and retrograde flow, as well as with noninvasive techniques using miniature oxygen electrodes, e.g. in livers perfused in either direction. Differences of opinion in the interpretation of studies with invasive and noninvasive techniques by the authors are discussed. The declining gradient in oxygen concentrations, the decreasing glucagon/insulin ratio and the different innervation could be important factors in the zonal expression of the genes of carbohydrate-metabolizing enzymes. While it is clear that

  20. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    International Nuclear Information System (INIS)

    Mohammad, Mohammad K.; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ► Human primary hepatocytes and cultured cell lines are used. ► Multiple cell death signaling pathways are activated by acrolein. ► Novel finding of

  1. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad, Mohammad K. [Department of Medicine, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Avila, Diana [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Zhang, Jingwen [Department of Medicine, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Barve, Shirish [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Arteel, Gavin [Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); McClain, Craig [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Robley Rex VAMC, Louisville, KY (United States); Joshi-Barve, Swati, E-mail: s0josh01@louisville.edu [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States)

    2012-11-15

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ► Human primary hepatocytes and cultured cell lines are used. ► Multiple cell death signaling pathways are activated by acrolein. ► Novel finding of

  2. Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

    International Nuclear Information System (INIS)

    Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa; Peterson, Darrell L.; Berrueta, Lisbeth; Salmen, Siham

    2016-01-01

    Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. - Highlights: • The expression and subcellular distribution of Foxp3, is modulated by PMA and preS1/2. • PMA and preS1/2 increase Foxp3 expression on HepG2. • PMA and preS1/2 induce foxp3 enrichment at mitochondrial, microsomal and nuclear compartments. • Results suggest a non-canonical function of Foxp3 or a mitochondrial transcriptional activity.

  3. Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Peterson, Darrell L. [Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA (United States); Berrueta, Lisbeth, E-mail: lberruet@ula.ve [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Division of Preventive Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Salmen, Siham, E-mail: sihamsa@ula.ve [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of)

    2016-05-01

    Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. - Highlights: • The expression and subcellular distribution of Foxp3, is modulated by PMA and preS1/2. • PMA and preS1/2 increase Foxp3 expression on HepG2. • PMA and preS1/2 induce foxp3 enrichment at mitochondrial, microsomal and nuclear compartments. • Results suggest a non-canonical function of Foxp3 or a mitochondrial transcriptional activity.

  4. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane.

    Science.gov (United States)

    Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M P; Albano, E; Bianchi, F B

    2000-04-01

    Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.

  5. Immortalized human hepatocytes as a tool for the study of hepatocytic (de-)differentiation

    NARCIS (Netherlands)

    Schippers, IJ; Moshage, H; Roelofsen, H; Muller, M; Heymans, HSA; Ruiters, M; Kuipers, F

    Primary human hepatocytes were immortalized by stable transfection with a recombinant plasmid containing the early region of simian virus (SV) 40. The cells were cultured in serum-free, hormonally defined medium during the immortalization procedure. Foci of dividing cells were seen after 3 months.

  6. Protective effect of kombucha tea against tertiary butyl hydroperoxide induced cytotoxicity and cell death in murine hepatocytes.

    Science.gov (United States)

    Bhattacharya, Semantee; Manna, Prasenjit; Gachhui, Ratan; Sil, Parames C

    2011-07-01

    Kombucha (KT), a fermented black tea (BT), is known to have many beneficial properties. In the present study, antioxidant property of KT has been investigated against tertiary butyl hydroperoxide (TBHP) induced cytotoxicity using murine hepatocytes. TBHP, a reactive oxygen species inducer, causes oxidative stress resulting in organ pathophysiology. Exposure to TBHP caused a reduction in cell viability, increased membrane leakage and disturbed the intra-cellular antioxidant machineries in hepatocytes. TBHP exposure disrupted mitochondrial membrane potential and induced apoptosis as evidenced by flow cytometric analyses. KT treatment, however, counteracted the changes in mitochondrial membrane potential and prevented apoptotic cell death of the hepatocytes. BT treatment also reverted TBHP induced hepatotoxicity, however KT was found to be more efficient. This may be due to the formation of antioxidant molecules like D-saccharic acid-1,4-lactone (DSL) during fermentation process and are absent in BT. Moreover, the radical scavenging activities of KT were found to be higher than BT. Results of the study showed that KT has the potential to ameliorate TBHP induced oxidative insult and cell death in murine hepatocytes more effectively than BT.

  7. Heart tissue of harlequin (hq)/Big Blue mice has elevated reactive oxygen species without significant impact on the frequency and nature of point mutations in nuclear DNA

    Energy Technology Data Exchange (ETDEWEB)

    Crabbe, Rory A. [Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Hill, Kathleen A., E-mail: khill22@uwo.ca [Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7 (Canada)

    2010-09-10

    Age is a major risk factor for heart disease, and cardiac aging is characterized by elevated mitochondrial reactive oxygen species (ROS) with compromised mitochondrial and nuclear DNA integrity. To assess links between increased ROS levels and mutations, we examined in situ levels of ROS and cII mutation frequency, pattern and spectrum in the heart of harlequin (hq)/Big Blue mice. The hq mouse is a model of premature aging with mitochondrial dysfunction and increased risk of oxidative stress-induced heart disease with the means for in vivo mutation detection. The hq mutation produces a significant downregulation in the X-linked apoptosis-inducing factor gene (Aif) impairing both the antioxidant and oxidative phosphorylation functions of AIF. Brain and skin of hq disease mice have elevated frequencies of point mutations in nuclear DNA and histopathology characterized by cell loss. Reports of associated elevations in ROS in brain and skin have mixed results. Herein, heart in situ ROS levels were elevated in hq disease compared to AIF-proficient mice (p < 0.0001) yet, mutation frequency and pattern were similar in hq disease, hq carrier and AIF-proficient mice. Heart cII mutations were also assessed 15 days following an acute exposure to an exogenous ROS inducer (10 mg paraquat/kg). Acute paraquat exposure with a short mutant manifestation period was insufficient to elevate mutation frequency or alter mutation pattern in the post-mitotic heart tissue of AIF-proficient mice. Paraquat induction of ROS requires mitochondrial complex I and thus is likely compromised in hq mice. Results of this preliminary survey and the context of recent literature suggest that determining causal links between AIF deficiency and the premature aging phenotypes of specific tissues is better addressed with assay of mitochondrial ROS and large-scale changes in mitochondrial DNA in specific cell types.

  8. Heart tissue of harlequin (hq)/Big Blue mice has elevated reactive oxygen species without significant impact on the frequency and nature of point mutations in nuclear DNA

    International Nuclear Information System (INIS)

    Crabbe, Rory A.; Hill, Kathleen A.

    2010-01-01

    Age is a major risk factor for heart disease, and cardiac aging is characterized by elevated mitochondrial reactive oxygen species (ROS) with compromised mitochondrial and nuclear DNA integrity. To assess links between increased ROS levels and mutations, we examined in situ levels of ROS and cII mutation frequency, pattern and spectrum in the heart of harlequin (hq)/Big Blue mice. The hq mouse is a model of premature aging with mitochondrial dysfunction and increased risk of oxidative stress-induced heart disease with the means for in vivo mutation detection. The hq mutation produces a significant downregulation in the X-linked apoptosis-inducing factor gene (Aif) impairing both the antioxidant and oxidative phosphorylation functions of AIF. Brain and skin of hq disease mice have elevated frequencies of point mutations in nuclear DNA and histopathology characterized by cell loss. Reports of associated elevations in ROS in brain and skin have mixed results. Herein, heart in situ ROS levels were elevated in hq disease compared to AIF-proficient mice (p < 0.0001) yet, mutation frequency and pattern were similar in hq disease, hq carrier and AIF-proficient mice. Heart cII mutations were also assessed 15 days following an acute exposure to an exogenous ROS inducer (10 mg paraquat/kg). Acute paraquat exposure with a short mutant manifestation period was insufficient to elevate mutation frequency or alter mutation pattern in the post-mitotic heart tissue of AIF-proficient mice. Paraquat induction of ROS requires mitochondrial complex I and thus is likely compromised in hq mice. Results of this preliminary survey and the context of recent literature suggest that determining causal links between AIF deficiency and the premature aging phenotypes of specific tissues is better addressed with assay of mitochondrial ROS and large-scale changes in mitochondrial DNA in specific cell types.

  9. Reactivity costs in MARIA reactor

    International Nuclear Information System (INIS)

    Marcinkowska, Zuzanna E.; Pytel, Krzysztof M.; Frydrysiak, Andrzej

    2017-01-01

    Highlights: • The methodology for calculating consumed fuel cost of excess reactivity is proposed. • Correlation between time integral of the core excess reactivity and released energy. • Reactivity price gives number of fuel elements required for given excess reactivity. - Abstract: For the reactor operation at high power level and carrying out experiments and irradiations the major cost of reactor operation is the expense of nuclear fuel. In this paper the methodology for calculating consumed fuel cost-relatedness of excess reactivity is proposed. Reactivity costs have been determined on the basis of operating data. A number of examples of calculating the reactivity costs for processes such as: strong absorbing material irradiation, molybdenium-99 production, beryllium matrix poisoning and increased moderator temperature illustrates proposed method.

  10. The potential of induced pluripotent stem cell derived hepatocytes.

    Science.gov (United States)

    Hannoun, Zara; Steichen, Clara; Dianat, Noushin; Weber, Anne; Dubart-Kupperschmitt, Anne

    2016-07-01

    Orthotopic liver transplantation remains the only curative treatment for liver disease. However, the number of patients who die while on the waiting list (15%) has increased in recent years as a result of severe organ shortages; furthermore the incidence of liver disease is increasing worldwide. Clinical trials involving hepatocyte transplantation have provided encouraging results. However, transplanted cell function appears to often decline after several months, necessitating liver transplantation. The precise aetiology of the loss of cell function is not clear, but poor engraftment and immune-mediated loss appear to be important factors. Also, primary human hepatocytes (PHH) are not readily available, de-differentiate, and die rapidly in culture. Hepatocytes are available from other sources, such as tumour-derived human hepatocyte cell lines and immortalised human hepatocyte cell lines or porcine hepatocytes. However, all these cells suffer from various limitations such as reduced or differences in functions or risk of zoonotic infections. Due to their significant potential, one possible inexhaustible source of hepatocytes is through the directed differentiation of human induced pluripotent stem cells (hiPSCs). This review will discuss the potential applications and existing limitations of hiPSC-derived hepatocytes in regenerative medicine, drug screening, in vitro disease modelling and bioartificial livers. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  11. Scintigraphic evidence of transplanted hepatocytes in spleen and liver

    International Nuclear Information System (INIS)

    Henne-Bruns, D.; Kremer, B.; Gramminger, K.; Broelsch, C.

    1986-01-01

    In rats suffering from hepatic enzymatic deficiency transplanted hepatocytes could be evidenced scintigraphically in liver, spleen and granulomas. In pigs, however, it is very difficult to demonstrate transplanted hepatocytes by scintiscanning because of the thickness of the tissues and the high background radiation in large animals

  12. Targeted deletion of hepatocyte Ikkβ confers growth advantages

    International Nuclear Information System (INIS)

    Koch, Katherine S.; Maeda, Shin; He, Guobin; Karin, Michael; Leffert, Hyam L.

    2009-01-01

    Mice lacking hepatocyte IKKβ (Ikkβ Δhep ) are defective in TNFα-activation of hepatocellular transcription factor NF-κB, and highly susceptible to hepatotoxicity. Following diethylnitrosamine (DEN) exposure, Ikkβ Δhep mice develop more hepatocellular carcinoma (HCC) than control mice due partly to enhanced DEN-induced hepatocyte death. Here we show that Ikkβ Δhep hepatocytes display growth advantages over normal hepatocytes consisting of precocious PCNA and cyclin D1 expression during liver regeneration (shortened hepatocyte G 0 → G 1 transitions), and enhanced recovery efficiency, cyclin D1 expression and cell proliferation after plating. Ex vivo deletion of Ikkβ also accelerates hepatocyte growth. Ikkβ Δhep hepatocyte proliferative responses show heightened sensitivity to TGFα and TNFα, and heightened expression of fibronectin, collagens I/III, nidogen, β-actin and integrin β1 mRNAs. These findings suggest that altered mitogen signaling and expression of extracellular matrix and its associated components underlie growth advantages. Increased HCC development in Ikkβ Δhep mice may also be caused by growth advantages of surviving Ikkβ-deleted hepatocytes.

  13. Cell swelling and glycogen metabolism in hepatocytes from fasted rats

    NARCIS (Netherlands)

    Gustafson, L. A.; Jumelle-Laclau, M. N.; van Woerkom, G. M.; van Kuilenburg, A. B.; Meijer, A. J.

    1997-01-01

    Cell swelling is known to increase net glycogen production from glucose in hepatocytes from fasted rats by activating glycogen synthase. Since both active glycogen synthase and phosphorylase are present in hepatocytes, suppression of flux through phosphorylase may also contribute to the net increase

  14. Stiffness of hyaluronic acid gels containing liver extracellular matrix supports human hepatocyte function and alters cell morphology.

    Science.gov (United States)

    Deegan, Daniel B; Zimmerman, Cynthia; Skardal, Aleksander; Atala, Anthony; Shupe, Thomas D

    2015-03-01

    Tissue engineering and cell based liver therapies have utilized primary hepatocytes with limited success due to the failure of hepatocytes to maintain their phenotype in vitro. In order to overcome this challenge, hyaluronic acid (HA) cell culture substrates were formulated to closely mimic the composition and stiffness of the normal liver cellular microenvironment. The stiffness of the substrate was modulated by adjusting HA hydrogel crosslinking. Additionally, the repertoire of bioactive molecules within the HA substrate was bolstered by supplementation with normal liver extracellular matrix (ECM). Primary human hepatocyte viability and phenotype were determined over a narrow physiologically relevant range of substrate stiffnesses from 600 to 4600Pa in both the presence and absence of liver ECM. Cell attachment, viability, and organization of the actin cytoskeleton improved with increased stiffness up to 4600Pa. These differences were not evident in earlier time points or substrates containing only HA. However, gene expression for the hepatocyte markers hepatocyte nuclear factor 4 alpha (HNF4α) and albumin significantly decreased on the 4600Pa stiffness at day 7 indicating that cells may not have maintained their phenotype long-term at this stiffness. Function, as measured by albumin secretion, varied with both stiffness and time in culture and peaked at day 7 at the 1200Pa stiffness, slightly below the stiffness of normal liver ECM at 3000Pa. Overall, gel stiffness affected primary human hepatocyte cell adhesion, functional marker expression, and morphological characteristics dependent on both the presence of liver ECM in gel substrates and time in culture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Ketose induced respiratory inhibition in isolated hepatocytes.

    Science.gov (United States)

    Martínez, P; Carrascosa, J M; Núñez de Castro, I

    1987-06-01

    The addition of 10 mM fructose or 10 mM tagatose to a suspension of hepatocytes caused respiratory inhibition, whereas no change in oxygen uptake was observed following the addition of glucose. However, incubations in the presence of fructose showed a high, aerobic glycolytic activity. Tagatose is phosphorylated to tagatose 1-phosphate but is not further metabolized by cell free liver extract. Moreover, the addition of fructose to glucagon treated cells also caused the Crabtree-like effect. The concentration of adenine nucleotides and inorganic phosphate (Pi) in the mitochondrial and cytosolic compartments during incubation (time 30 min) was determined by the digitonin fractionation procedure. In the presence of 10 mM fructose or tagatose, the total adenine nucleotide pools decreased by 40%; however, glucose produced no change. The addition of ketoses diminished the asymmetric distribution of extramitochondrial (ATP/ADP)e ratio and intramitochondrial (ATP/ADP)i ratio. At the same time the total mitochondrial Pi fell from 17 mM to 6-7 mM. The mitochondrial membrane potential (-161 mV) in the presence of fructose showed no changes during the 30 min experimental period. An increase in the NADH/NAD+ ratio was observed. These results suggest that in hepatocytes the inhibition of respiration is not necessarily linked with the enhanced aerobic glycolysis, by competition for common substrates.

  16. Insulin internalization in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Galan, J.; Trankina, M.; Noel, R.; Ward, W.

    1990-01-01

    This project was designed to determine whether neomycin, an aminoglycoside antibiotic, has a significant effect upon the pathways of ligand endocytosis in isolated rat hepatocytes. The pathways studied include receptor-mediated endocytosis and fluid-phase endocytosis. Neomycin causes a dose-dependent acceleration of 125 I-insulin internalization. Since fluid-phase endocytosis can also be a significant factor in 125 I-insulin internalization, lucifer yellow (LY), a marker for fluid-phase endocytosis, was incorporated into an assay similar to the 125 I-insulin internalization procedure. In the presence of 5 mM neomycin, a significant increase in LY uptake was evident at 0.2 and 0.4 mg/ml of LY. At 0.8 mg/ml, a decrease in LY uptake was observed. The increased rate of 125 I-insulin internalization in the presence of neomycin was intriguing. Since one action of neomycin is to inhibit phosphoinositidase C, it suggests that the phosphotidylinositol cycle may be involved in ligand internalization by hepatocytes. At low insulin concentrations, receptor-mediated uptake predominates. Fluid-phase uptake can become an important uptake route as insulin concentrations are increased. Since neomycin stimulates fluid-phase endocytosis, it must also be taken into account when measuring ligand internalization

  17. Property of hepatitis B virus replication in Tupaia belangeri hepatocytes

    International Nuclear Information System (INIS)

    Sanada, Takahiro; Tsukiyama-Kohara, Kyoko; Yamamoto, Naoki; Ezzikouri, Sayeh; Benjelloun, Soumaya; Murakami, Shuko; Tanaka, Yasuhito; Tateno, Chise; Kohara, Michinori

    2016-01-01

    The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3–6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10"5 copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10"4-10"6 copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10"3 copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. - Highlights: • Primary hepatocytes were established from tupaia that is a novel HBV infection model. • Tupaia primary hepatocytes were susceptible for HBV infection. • The immunodeficient chimeric mice with tupaia hepatocytes were established. • The chimeric mice with tupaia hepatocytes were susceptible for HBV infection.

  18. Property of hepatitis B virus replication in Tupaia belangeri hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Sanada, Takahiro [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Tsukiyama-Kohara, Kyoko, E-mail: kkohara@vet.kagoshima-u.ac.jp [Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima-city, Kagoshima 890-0065 (Japan); Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Yamamoto, Naoki [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Ezzikouri, Sayeh; Benjelloun, Soumaya [Viral Hepatitis Laboratory, Virology Unit, Institut Pasteur du Maroc, 1, Louis Pasteur, Casablanca 20360 (Morocco); Murakami, Shuko; Tanaka, Yasuhito [Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Kawasumi 1, Mizuho-ku, Nagoya, Aichi 467-8601 (Japan); Tateno, Chise [PhoenixBio Co. Ltd., 3-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan); Kohara, Michinori, E-mail: kohara-mc@igakuken.or.jp [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan)

    2016-01-08

    The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3–6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10{sup 5} copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10{sup 4}-10{sup 6} copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10{sup 3} copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. - Highlights: • Primary hepatocytes were established from tupaia that is a novel HBV infection model. • Tupaia primary hepatocytes were susceptible for HBV infection. • The immunodeficient chimeric mice with tupaia hepatocytes were established. • The chimeric mice with tupaia hepatocytes were susceptible for HBV infection.

  19. Effect of guava (Psidium guajava L.) leaf extract on glucose uptake in rat hepatocytes.

    Science.gov (United States)

    Cheng, Fang-Chi; Shen, Szu-Chuan; Wu, James Swi-Bea

    2009-06-01

    People in oriental countries, including Japan and Taiwan, boil guava leaves (Psidium guajava L.) in water and drink the extract as a folk medicine for diabetes. The present study investigated the enhancement of aqueous guava leaf extract on glucose uptake in rat clone 9 hepatocytes and searched for the active compound. The extract was eluted with MeOH-H(2)O solutions through Diaion, Sephadex, and MCI-gel columns to separate into fractions with different polarities. The uptake test of 2-[1-(14)C] deoxy-D-glucose in rat clone 9 hepatocytes was performed to evaluate the hypoglycemic effect of these fractions. The active compound was identified by nuclear magnetic resonance analysis and high-performance liquid chromatography (HPLC). The results revealed that phenolics are the principal component of the extract, that high polarity fractions of the guava leaf extract are enhancers to glucose uptake in rat clone 9 hepatocytes, and that quercetin is the major active compound. We suggest that quercetin in the aqueous extract of guava leaves promotes glucose uptake in liver cells, and contributes to the alleviation of hypoglycemia in diabetes as a consequence.

  20. Effects of hepatocyte growth factor on glutathione synthesis, growth, and apoptosis is cell density-dependent

    International Nuclear Information System (INIS)

    Yang Heping; Magilnick, Nathaniel; Xia Meng; Lu, Shelly C.

    2008-01-01

    Hepatocyte growth factor (HGF) is a potent hepatocyte mitogen that exerts opposing effects depending on cell density. Glutathione (GSH) is the main non-protein thiol in mammalian cells that modulates growth and apoptosis. We previously showed that GSH level is inversely related to cell density of hepatocytes and is positively related to growth. Our current work examined whether HGF can modulate GSH synthesis in a cell density-dependent manner and how GSH in turn influence HGF's effects. We found HGF treatment of H4IIE cells increased cell GSH levels only under subconfluent density. The increase in cell GSH under low density was due to increased transcription of GSH synthetic enzymes. This correlated with increased protein levels and nuclear binding activities of c-Jun, c-Fos, p65, p50, Nrf1 and Nrf2 to the promoter region of these genes. HGF acts as a mitogen in H4IIE cells under low cell density and protects against tumor necrosis factor α (TNFα)-induced apoptosis by limiting JNK activation. However, HGF is pro-apoptotic under high cell density and exacerbates TNFα-induced apoptosis by potentiating JNK activation. The increase in cell GSH under low cell density allows HGF to exert its full mitogenic effect but is not necessary for its anti-apoptotic effect

  1. Study on radioprotection of alliin and damage mechanism in hepatocyte after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Tae Jeong; Kim, Won Tae [Dept, of Radiological Science, Kaya University, Kimhae (Korea, Republic of)

    2016-12-15

    Liver tissue damage by a radiation exposure caused a jaundice and ascitic fluid e form harden atrophy. The reason for this lies in morphological damage of a liver cells. This study tried that observe damage mechanism of the cell organelles. It was especially observed mitochondria, endoplasmic reticulum and nuclear membrane associated with energy metabolizable. also, This study had with a radio-protector development research at the same time. Radio-protector was used to alliin that has an blood flow increase. Cell observation make used of transmission electron microscope(TEM). The result of an experiment, 7Gy of whole body irradiation was caused an inflammation in cell organelles and hypertrophy of the nucleus membrane. After 20 days, The hepatocyte has been observed in a damaged membrane on peroxisome, mitochondria and vacuole of the cell organelles. After 30 days, The hepatocyte has been observed in disconnected ribosomes on a rough endoplasmic reticulum. There was looked a giant lipoblast. There was clearly normal observed a mitochondria and nucleus membrane in the hepatocyte after alliin injection. aslo, It was no damaged the nucleus membrane. Therefore, It was identified portion a radio-protector effect from alliin.

  2. Trichostatin A, a critical factor in maintaining the functional differentiation of primary cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Henkens, Tom; Papeleu, Peggy; Elaut, Greetje; Vinken, Mathieu; Rogiers, Vera; Vanhaecke, Tamara

    2007-01-01

    Histone deacetylase inhibitors (HDI) have been shown to increase differentiation-related gene expression in several tumor-derived cell lines by hyperacetylating core histones. Effects of HDI on primary cultured cells, however, have hardly been investigated. In the present study, the ability of trichostatin A (TSA), a prototype hydroxamate HDI, to counteract the loss of liver-specific functions in primary rat hepatocyte cultures has been investigated. Upon exposure to TSA, it was found that the cell viability of the cultured hepatocytes and their albumin secretion as a function of culture time were increased. TSA-treated hepatocytes also better maintained cytochrome P450 (CYP)-mediated phase I biotransformation capacity, whereas the activity of phase II glutathione S-transferases (GST) was not affected. Western blot and qRT-PCR analysis of CYP1A1, CYP2B1 and CYP3A11 protein and mRNA levels, respectively, further revealed that TSA acts at the transcriptional level. In addition, protein expression levels of the liver-enriched transcription factors (LETFs) hepatic nuclear factor 4 alpha (HNF4α) and CCAAT/enhancer binding protein alpha (C/EBPα) were accordingly increased by TSA throughout culture time. In conclusion, these findings indicate that TSA plays a major role in the preservation of the differentiated hepatic phenotype in culture. It is suggested that the effects of TSA on CYP gene expression are mediated via controlling the expression of LETFs

  3. Prolyl hydroxylase-1 regulates hepatocyte apoptosis in an NF-κB-dependent manner

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, Susan F.; Fábián, Zsolt; Schaible, Bettina; Lenihan, Colin R.; Schwarzl, Thomas [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Rodriguez, Javier [Systems Biology Ireland, University College Dublin, Dublin 4 (Ireland); Zheng, Xingnan; Li, Zongwei [Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC (United States); Tambuwala, Murtaza M. [School of Pharmacy and Pharmaceutical Sciences, Ulster University, Coleraine, BT52 1SA, Northern Ireland (United Kingdom); Higgins, Desmond G.; O' Meara, Yvonne [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Slattery, Craig [School of Biomolecular and Biomedical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Manresa, Mario C. [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); Fraisl, Peter; Bruning, Ulrike [Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, University of Leuven, Vesalius Research Center, VIB, B-3000 (Belgium); Baes, Myriam [Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven (Belgium); Carmeliet, Peter; Doherty, Glen [Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, University of Leuven, Vesalius Research Center, VIB, B-3000 (Belgium); Kriegsheim, Alex von [Systems Biology Ireland, University College Dublin, Dublin 4 (Ireland); Cummins, Eoin P. [School of Medicine and Medical Science, The Conway Institute, University College Dublin, Belfield, Dublin 4 Ireland (Ireland); and others

    2016-06-03

    Hepatocyte death is an important contributing factor in a number of diseases of the liver. PHD1 confers hypoxic sensitivity upon transcription factors including the hypoxia inducible factor (HIF) and nuclear factor-kappaB (NF-κB). Reduced PHD1 activity is linked to decreased apoptosis. Here, we investigated the underlying mechanism(s) in hepatocytes. Basal NF-κB activity was elevated in PHD1{sup −/−} hepatocytes compared to wild type controls. ChIP-seq analysis confirmed enhanced binding of NF-κB to chromatin in regions proximal to the promoters of genes involved in the regulation of apoptosis. Inhibition of NF-κB (but not knock-out of HIF-1 or HIF-2) reversed the anti-apoptotic effects of pharmacologic hydroxylase inhibition. We hypothesize that PHD1 inhibition leads to altered expression of NF-κB-dependent genes resulting in reduced apoptosis. This study provides new information relating to the possible mechanism of therapeutic action of hydroxylase inhibitors that has been reported in pre-clinical models of intestinal and hepatic disease. -- Highlights: •Genetic ablation of PHD1 upregulates NF-kappaB (NF-κB) in hepatocytes. •Activation of NF-κB leads to differential DNA-binding of p50/p65 and results in differential regulation of apoptotic genes. •We identified proline 191 in the beta subunit of the I-kappaB kinase as a target for PHD1-mediated hydroxylation. •Blockade of prolyl-4-hydroxylases has been found cytoprotective in liver cells.

  4. Protective effect of curcumin and its analog on γ-radiation induced DNA damage and lipid peroxidation in cultured human lymphocytes and isolated rat hepatocytes in vitro

    International Nuclear Information System (INIS)

    Menon, Venugopal P.

    2007-01-01

    Ionizing radiation is known to induce oxidative stress through generation of reactive oxygen species (ROS) resulting in an imbalance of the pro-oxidant and antioxidant status in the cells, which is suggested to culminate in cell death. The present work was aimed to evaluate the radioprotective effect of curcumin and its analog on γ-radiation induced toxicity in cultured human lymphocytes and rat hepatocytes. Hepatocytes were isolated from the liver of rats by collagenase perfusion. The cellular changes were estimated using lipid peroxidative indices like thiobarbituric acid reactive substances (TBARS), the antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and reduced glutathione (GSH). The DNA damage was analyzed by comet assay, cytokinesis blocked micro nucleus assay, dicentric aberrations and translocation frequency. Cell cycle distribution and measurement of the percentage of apoptotic cells were performed by flow cytometry analysis. To investigate whether the dietary agents like curcumin and its analog have a role on cell cycle regulation, we analyzed the changes in cell cycle profiles by using fluorescence activated cell sorter. The increase in the severity of DNA damage was observed with the increase dose (1, 2 and 4 Gy) of γ-radiation in cultured lymphocytes and hepatocytes. TBARS were increased significantly, whereas the levels of GSH and antioxidant enzymes were significantly decreased in γ-irradiated hepatocytes and lymphocytes. On pretreatment with curcumin and its analog (1, 5 and 10 μg/ml) showed a significant decrease in the levels of TBARS and DNA damage. The antioxidant enzymes were increased significantly along with the levels of GSH. The maximum protection of hepatocytes and lymphocytes was observed at 10 μg/ml curcumin and 5 μg/ml curcumin analog pretreatment. Thus, pretreatment with curcumin and its analog helps in protecting the normal hepatocytes and lymphocytes against γ-radiation induced cellular

  5. Serum levels of pancreatic stone protein (PSP/reg1A as an indicator of beta-cell apoptosis suggest an increased apoptosis rate in hepatocyte nuclear factor 1 alpha (HNF1A-MODY carriers from the third decade of life onward

    Directory of Open Access Journals (Sweden)

    Bacon Siobhan

    2012-07-01

    Full Text Available Abstract Background Mutations in the transcription factor hepatocyte nuclear factor-1-alpha (HNF1A result in the commonest type of maturity onset diabetes of the young (MODY. HNF1A-MODY carriers have reduced pancreatic beta cell mass, partially due to an increased rate of apoptosis. To date, it has not been possible to determine when apoptosis is occurring in HNF1A-MODY.We have recently demonstrated that beta cell apoptosis stimulates the expression of the pancreatic stone protein/regenerating (PSP/reg gene in surviving neighbour cells, and that PSP/reg1A protein is subsequently secreted from these cells. The objective of this study was to determine whether serum levels of PSP/reg1A are elevated during disease progression in HNF1A-MODY carriers, and whether it may provide information regarding the onset of beta-cell apoptosis. Methods We analysed serum PSP/reg1A levels and correlated with clinical and biochemical parameters in subjects with HNF1A-MODY, glucokinase (GCK-MODY, and type 1 diabetes mellitus. A control group of normoglycaemic subjects was also analysed. Results PSP/reg1A serum levels were significantly elevated in HNF1A-MODY (n = 37 subjects compared to controls (n = 60 (median = 12.50 ng/ml, IQR = 10.61-17.87 ng/ml versus median = 10.72 ng/ml, IQR = 8.94-12.54 ng/ml, p = 0.0008. PSP/reg1A correlated negatively with insulin levels during OGTT, (rho = −0.40, p = 0.02. Interestingly we noted a significant positive correlation of PSP/reg1A with age of the HNF1A-MODY carriers (rho = 0.40 p = 0.02 with an age of 25 years separating carriers with low and high PSP/reg1A levels. Patients with type 1 diabetes mellitus also had elevated serum levels of PSP/reg1A compared to controls, however this was independent of the duration of diabetes. Conclusion Our data suggest that beta cell apoptosis contributes increasingly to the pathophysiology of HNF1A-MODY in patients 25 years and over

  6. Serum levels of pancreatic stone protein (PSP)/reg1A as an indicator of beta-cell apoptosis suggest an increased apoptosis rate in hepatocyte nuclear factor 1 alpha (HNF1A-MODY) carriers from the third decade of life onward

    LENUS (Irish Health Repository)

    Bacon, Siobhan

    2012-07-18

    AbstractBackgroundMutations in the transcription factor hepatocyte nuclear factor-1-alpha (HNF1A) result in the commonest type of maturity onset diabetes of the young (MODY). HNF1A-MODY carriers have reduced pancreatic beta cell mass, partially due to an increased rate of apoptosis. To date, it has not been possible to determine when apoptosis is occurring in HNF1A-MODY.We have recently demonstrated that beta cell apoptosis stimulates the expression of the pancreatic stone protein\\/regenerating (PSP\\/reg) gene in surviving neighbour cells, and that PSP\\/reg1A protein is subsequently secreted from these cells. The objective of this study was to determine whether serum levels of PSP\\/reg1A are elevated during disease progression in HNF1A-MODY carriers, and whether it may provide information regarding the onset of beta-cell apoptosis.MethodsWe analysed serum PSP\\/reg1A levels and correlated with clinical and biochemical parameters in subjects with HNF1A-MODY, glucokinase (GCK-MODY), and type 1 diabetes mellitus. A control group of normoglycaemic subjects was also analysed.ResultsPSP\\/reg1A serum levels were significantly elevated in HNF1A-MODY (n = 37) subjects compared to controls (n = 60) (median = 12.50 ng\\/ml, IQR = 10.61-17.87 ng\\/ml versus median = 10.72 ng\\/ml, IQR = 8.94-12.54 ng\\/ml, p = 0.0008). PSP\\/reg1A correlated negatively with insulin levels during OGTT, (rho = −0.40, p = 0.02). Interestingly we noted a significant positive correlation of PSP\\/reg1A with age of the HNF1A-MODY carriers (rho = 0.40 p = 0.02) with an age of 25 years separating carriers with low and high PSP\\/reg1A levels. Patients with type 1 diabetes mellitus also had elevated serum levels of PSP\\/reg1A compared to controls, however this was independent of the duration of diabetes.ConclusionOur data suggest that beta cell apoptosis contributes increasingly to the pathophysiology of HNF1A-MODY in patients 25 years and

  7. Monte Carlo analysis of KRITZ-2 critical benchmarks on the reactivity temperature coefficient using ENDF/B-VII.1 and JENDL-4.0 nuclear data libraries

    International Nuclear Information System (INIS)

    El Ouahdani, S.; Boukhal, H.; Erradi, L.; Chakir, E.; El Bardouni, T.; Hajjaji, O.; Boulaich, Y.; Benaalilou, K.; Kaddour, M.

    2016-01-01

    also analyzed the temperature effect on the leakage by calculating the non leakage probability and the associated temperature coefficient. The overestimation of the calculated non-leakage probability values using JENDL-4 relatively to the calculated one using ENDF/B-VII.1 for all configurations and all temperatures can be explained by the overestimation of the absorptions in the JENDL-4 library especially in the resonance of the heavy nuclides. We can note that this discrepancy between the libraries decreases in hot conditions. For the reactivity temperature coefficient, our analysis has shown that the tendency of a negative error (overestimation by calculation of the absolute value of the RTC) usually observed when analyzing similar UO 2 and MOX LWR lattices is confirmed. However, the level of the calculation error has been reduced significantly by using Monte Carlo modeling associated with the most recent nuclear data libraries.

  8. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver

    International Nuclear Information System (INIS)

    Reaiche-Miller, Georget Y.; Thorpe, Michael; Low, Huey Chi; Qiao, Qiao; Scougall, Catherine A.; Mason, William S.; Litwin, Samuel; Jilbert, Allison R.

    2013-01-01

    Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10 5 -fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis. - Highlights: • The hepatitis B virus nuclear template is covalently closed circular DNA (cccDNA). • cccDNA was studied during liver growth in duck hepatitis B virus infected ducks. • Virus DNA replication and new cccDNA synthesis were inhibited with Entecavir. • At least 49% of cccDNA appeared to survive hepatocyte mitosis. • Low level virus DNA synthesis may contribute to survival of cccDNA through mitosis

  9. Duck hepatitis B virus covalently closed circular DNA appears to survive hepatocyte mitosis in the growing liver

    Energy Technology Data Exchange (ETDEWEB)

    Reaiche-Miller, Georget Y.; Thorpe, Michael; Low, Huey Chi; Qiao, Qiao; Scougall, Catherine A. [School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005 (Australia); Mason, William S.; Litwin, Samuel [Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111 (United States); Jilbert, Allison R., E-mail: allison.jilbert@adelaide.edu.au [School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005 (Australia)

    2013-11-15

    Nucleos(t)ide analogues that inhibit hepatitis B virus (HBV) DNA replication are typically used as monotherapy for chronically infected patients. Treatment with a nucleos(t)ide analogue eliminates most HBV DNA replication intermediates and produces a gradual decline in levels of covalently closed circular DNA (cccDNA), the template for viral RNA synthesis. It remains uncertain if levels of cccDNA decline primarily through hepatocyte death, or if loss also occurs during hepatocyte mitosis. To determine if cccDNA survives mitosis, growing ducklings infected with duck hepatitis B virus (DHBV) were treated with the nucleoside analogue, Entecavir. Viremia was suppressed at least 10{sup 5}-fold, during a period when average liver mass increased 23-fold. Analysis of the data suggested that if cccDNA synthesis was completely inhibited, at least 49% of cccDNA survived hepatocyte mitosis. However, there was a large duck-to-duck variation in cccDNA levels, suggesting that low level cccDNA synthesis may contribute to this apparent survival through mitosis. - Highlights: • The hepatitis B virus nuclear template is covalently closed circular DNA (cccDNA). • cccDNA was studied during liver growth in duck hepatitis B virus infected ducks. • Virus DNA replication and new cccDNA synthesis were inhibited with Entecavir. • At least 49% of cccDNA appeared to survive hepatocyte mitosis. • Low level virus DNA synthesis may contribute to survival of cccDNA through mitosis.

  10. Role of nuclear factor kappa B and reactive oxygen species in the tumor necrosis factor-a-induced epithelial-mesenchymal transition of MCF-7 cells

    Directory of Open Access Journals (Sweden)

    R. Dong

    2007-08-01

    Full Text Available The microenvironment of the tumor plays an important role in facilitating cancer progression and activating dormant cancer cells. Most tumors are infiltrated with inflammatory cells which secrete cytokines such as tumor necrosis factor-a (TNF-a. To evaluate the role of TNF-a in the development of cancer we studied its effects on cell migration with a migration assay. The migrating cell number in TNF-a -treated group is about 2-fold of that of the control group. Accordingly, the expression of E-cadherin was decreased and the expression of vimentin was increased upon TNF-a treatment. These results showed that TNF-a can promote epithelial-mesenchymal transition (EMT of MCF-7 cells. Further, we found that the expression of Snail, an important transcription factor in EMT, was increased in this process, which is inhibited by the nuclear factor kappa B (NFkB inhibitor aspirin while not affected by the reactive oxygen species (ROS scavenger N-acetyl cysteine. Consistently, specific inhibition of NFkB by the mutant IkBa also blocked the TNF-a-induced upregulation of Snail promoter activity. Thus, the activation of NFkB, which causes an increase in the expression of the transcription factor Snail is essential in the TNF-a-induced EMT. ROS caused by TNF-a seemed to play a minor role in the TNF-a-induced EMT of MCF-7 cells, though ROS per se can promote EMT. These findings suggest that different mechanisms might be responsible for TNF-a - and ROS-induced EMT, indicating the need for different strategies for the prevention of tumor metastasis induced by different stimuli.

  11. Caspase 1 activation is protective against hepatocyte cell death by up-regulating beclin 1 protein and mitochondrial autophagy in the setting of redox stress.

    Science.gov (United States)

    Sun, Qian; Gao, Wentao; Loughran, Patricia; Shapiro, Rick; Fan, Jie; Billiar, Timothy R; Scott, Melanie J

    2013-05-31

    Caspase 1 activation can be induced by oxidative stress, which leads to the release of the proinflammatory cytokines IL1β and IL18 in myeloid cells and a potentially damaging inflammatory response. However, little is known about the role of caspase 1 in non-immune cells, such as hepatocytes, that express and activate the inflammasome but do not produce a significant amount of IL1β/IL18. Here we demonstrate that caspase 1 activation protects against cell death after redox stress induced by hypoxia/reoxygenation in hepatocytes. Mechanistically, we show that caspase 1 reduces mitochondrial respiration and reactive oxygen species by increasing mitochondrial autophagy and subsequent clearance of mitochondria in hepatocytes after hypoxia/reoxygenation. Caspase 1 increases autophagic flux through up-regulating autophagy initiator beclin 1 during redox stress and is an important cell survival factor in hepatocytes. We find that during hemorrhagic shock with resuscitation, an in vivo mouse model associated with severe hepatic redox stress, caspase 1 activation is also protective against liver injury and excessive oxidative stress through the up-regulation of beclin 1. Our findings suggest an alternative role for caspase 1 activation in promoting adaptive responses to oxidative stress and, more specifically, in limiting reactive oxygen species production and damage in cells and tissues where IL1β/IL18 are not highly expressed.

  12. Caspase 1 Activation Is Protective against Hepatocyte Cell Death by Up-regulating Beclin 1 Protein and Mitochondrial Autophagy in the Setting of Redox Stress*

    Science.gov (United States)

    Sun, Qian; Gao, Wentao; Loughran, Patricia; Shapiro, Rick; Fan, Jie; Billiar, Timothy R.; Scott, Melanie J.

    2013-01-01

    Caspase 1 activation can be induced by oxidative stress, which leads to the release of the proinflammatory cytokines IL1β and IL18 in myeloid cells and a potentially damaging inflammatory response. However, little is known about the role of caspase 1 in non-immune cells, such as hepatocytes, that express and activate the inflammasome but do not produce a significant amount of IL1β/IL18. Here we demonstrate that caspase 1 activation protects against cell death after redox stress induced by hypoxia/reoxygenation in hepatocytes. Mechanistically, we show that caspase 1 reduces mitochondrial respiration and reactive oxygen species by increasing mitochondrial autophagy and subsequent clearance of mitochondria in hepatocytes after hypoxia/reoxygenation. Caspase 1 increases autophagic flux through up-regulating autophagy initiator beclin 1 during redox stress and is an important cell survival factor in hepatocytes. We find that during hemorrhagic shock with resuscitation, an in vivo mouse model associated with severe hepatic redox stress, caspase 1 activation is also protective against liver injury and excessive oxidative stress through the up-regulation of beclin 1. Our findings suggest an alternative role for caspase 1 activation in promoting adaptive responses to oxidative stress and, more specifically, in limiting reactive oxygen species production and damage in cells and tissues where IL1β/IL18 are not highly expressed. PMID:23589298

  13. Reactive Arthritis

    Directory of Open Access Journals (Sweden)

    Eren Erken

    2013-06-01

    Full Text Available Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropaty which has occured as a result of an infectious processes, mostly after gastrointestinal and genitourinary tract infections. Reiter syndrome is a frequent type of reactive arthritis. Both reactive arthritis and Reiter syndrome belong to the group of seronegative spondyloarthropathies, associated with HLA-B27 positivity and characterized by ongoing inflammation after an infectious episode. The classical triad of Reiter syndrome is defined as arthritis, conjuctivitis and urethritis and is seen only in one third of patients with Reiter syndrome. Recently, seronegative asymmetric arthritis and typical extraarticular involvement are thought to be adequate for the diagnosis. However, there is no established criteria for the diagnosis of reactive arthritis and the number of randomized and controlled studies about the therapy is not enough. [Archives Medical Review Journal 2013; 22(3.000: 283-299

  14. Phenotypic and functional analyses show stem cell-derived hepatocyte-like cells better mimic fetal rather than adult hepatocytes.

    Science.gov (United States)

    Baxter, Melissa; Withey, Sarah; Harrison, Sean; Segeritz, Charis-Patricia; Zhang, Fang; Atkinson-Dell, Rebecca; Rowe, Cliff; Gerrard, Dave T; Sison-Young, Rowena; Jenkins, Roz; Henry, Joanne; Berry, Andrew A; Mohamet, Lisa; Best, Marie; Fenwick, Stephen W; Malik, Hassan; Kitteringham, Neil R; Goldring, Chris E; Piper Hanley, Karen; Vallier, Ludovic; Hanley, Neil A

    2015-03-01

    Hepatocyte-like cells (HLCs), differentiated from pluripotent stem cells by the use of soluble factors, can model human liver function and toxicity. However, at present HLC maturity and whether any deficit represents a true fetal state or aberrant differentiation is unclear and compounded by comparison to potentially deteriorated adult hepatocytes. Therefore, we generated HLCs from multiple lineages, using two different protocols, for direct comparison with fresh fetal and adult hepatocytes. Protocols were developed for robust differentiation. Multiple transcript, protein and functional analyses compared HLCs to fresh human fetal and adult hepatocytes. HLCs were comparable to those of other laboratories by multiple parameters. Transcriptional changes during differentiation mimicked human embryogenesis and showed more similarity to pericentral than periportal hepatocytes. Unbiased proteomics demonstrated greater proximity to liver than 30 other human organs or tissues. However, by comparison to fresh material, HLC maturity was proven by transcript, protein and function to be fetal-like and short of the adult phenotype. The expression of 81% phase 1 enzymes in HLCs was significantly upregulated and half were statistically not different from fetal hepatocytes. HLCs secreted albumin and metabolized testosterone (CYP3A) and dextrorphan (CYP2D6) like fetal hepatocytes. In seven bespoke tests, devised by principal components analysis to distinguish fetal from adult hepatocytes, HLCs from two different source laboratories consistently demonstrated fetal characteristics. HLCs from different sources are broadly comparable with unbiased proteomic evidence for faithful differentiation down the liver lineage. This current phenotype mimics human fetal rather than adult hepatocytes. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  15. Choline and methionine differentially alter methyl carbon metabolism in bovine neonatal hepatocytes.

    Science.gov (United States)

    Chandler, Tawny L; White, Heather M

    2017-01-01

    Intersections in hepatic methyl group metabolism pathways highlights potential competition or compensation of methyl donors. The objective of this experiment was to examine the expression of genes related to methyl group transfer and lipid metabolism in response to increasing concentrations of choline chloride (CC) and DL-methionine (DLM) in primary neonatal hepatocytes that were or were not exposed to fatty acids (FA). Primary hepatocytes isolated from 4 neonatal Holstein calves were maintained as monolayer cultures for 24 h before treatment with CC (61, 128, 2028, and 4528 μmol/L) and DLM (16, 30, 100, 300 μmol/L), with or without a 1 mmol/L FA cocktail in a factorial arrangement. After 24 h of treatment, media was collected for quantification of reactive oxygen species (ROS) and very low-density lipoprotein (VLDL), and cell lysates were collected for quantification of gene expression. No interactions were detected between CC, DLM, or FA. Both CC and DLM decreased the expression of methionine adenosyltransferase 1A (MAT1A). Increasing CC did not alter betaine-homocysteine S-methyltranferase (BHMT) but did increase 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) and methylenetetrahydrofolate reductase (MTHFR) expression. Increasing DLM decreased expression of BHMT and MTR, but did not affect MTHFR. Expression of both phosphatidylethanolamine N-methyltransferase (PEMT) and microsomal triglyceride transfer protein (MTTP) were decreased by increasing CC and DLM, while carnitine palmitoyltransferase 1A (CPT1A) was unaffected by either. Treatment with FA decreased the expression of MAT1A, MTR, MTHFR and tended to decrease PEMT but did not affect BHMT and MTTP. Treatment with FA increased CPT1A expression. Increasing CC increased secretion of VLDL and decreased the accumulation of ROS in media. Within neonatal bovine hepatocytes, choline and methionine differentially regulate methyl carbon pathways and suggest that choline may play a critical role in

  16. A characterization of the ZFL cell line and primary hepatocytes as in vitro liver cell models for the zebrafish (Danio rerio)

    International Nuclear Information System (INIS)

    Eide, Marta; Rusten, Marte; Male, Rune; Jensen, Knut Helge Midtbø; Goksøyr, Anders

    2014-01-01

    Highlights: •The ZFL cell line and primary hepatocytes were characterized. •Basic and induced expression of nuclear receptors and target genes were found. •The ZFL cell line expresses very low basic levels of most genes. •The ZFL cells have low induction of gene expression following exposures. •Primary hepatocytes show large sex-dependent differences in gene expression. -- Abstract: The zebrafish (Danio rerio) is a widely used model species in biomedical research. The ZFL cell line, established from zebrafish liver, and freshly isolated primary hepatocytes from zebrafish have been used in several toxicological studies. However, no previous report has compared and characterized these two systems at the level of gene expression. The aim of this study was to evaluate the ZFL cell line in comparison to primary hepatocytes as in vitro models for studying effects of environmental contaminants in zebrafish liver. Using quantitative real-time PCR, the basal level and transcriptional induction potential of key genes involved in toxic responses in the ZFL cell line, primary hepatocytes and whole liver from zebrafish were compared. The study showed that the ZFL cells have lower levels of mRNA of most selected genes compared to zebrafish liver. The induced gene transcription following exposure to ligand was much lower in ZFL cells compared to zebrafish primary hepatocytes at the doses tested. Importantly, oestrogen receptor and vitellogenin genes showed low basal transcription and no induction response in the ZFL cell line. In conclusion, it appears that primary hepatocytes are well suited for studying environmental contaminants including xenoestrogens, but may show large sex-dependent differences in gene transcription. The ZFL cell line shows potential in toxicological studies involving the aryl hydrocarbon receptor pathway. However, low potential for transcriptional induction of genes in general should be expected, especially notable when studying estrogenic

  17. Direct induction of hepatocyte-like cells from immortalized human bone marrow mesenchymal stem cells by overexpression of HNF4α

    International Nuclear Information System (INIS)

    Hu, Xiaojun; Xie, Peiyi; Li, Weiqiang; Li, Zhengran; Shan, Hong

    2016-01-01

    Hepatocytes from human bone marrow-derived mesenchymal stem cells (hBM-MSCs) are expected to be a useful source for cell transplantation. However, relatively low efficiency and repeatability of hepatic differentiation of human BM-MSCs remains an obstacle for clinical translation. Hepatocyte nuclear factor 4 alpha (HNF4α), a critical transcription factor, plays an essential role in the entire process of liver development. In this study, immortalized hBM-MSCs, UE7T-13 cells were transduced with a lentiviral vector containing HNF4α. The typical fibroblast-like morphology of the MSCs changed, and polygonal, epithelioid cells grew out after HNF4α transduction. In hepatocyte culture medium, HNF4α-transduced MSCs (E7-hHNF4α cells) strongly expressed the albumin (ALB), CYP2B6, alpha-1 antitrypsin (AAT), and FOXA2 mRNA and exhibited morphology markedly similar to that of mature hepatocytes. The E7-hHNF4α cells showed hepatic functions such as Indocyanine green (ICG) uptake and release, glycogen storage, urea production and ALB secretion. Approximately 28% of E7-hHNF4α cells expressed both ALB and AAT. Furthermore, these E7-hHNF4α cells via superior mesenteric vein (SMV) injection expressed human ALB in mouse chronic injured liver. In conclusion, this study represents a novel strategy by directly inducing hepatocyte-like cells from MSCs. - Highlights: • We overexpressed HNF4α in immortalized BM-MSCs by lentiviral transduction. • HNF4α-transduced MSCs transdifferentiated into hepatocytes with mature hepatic metabolic functions. • Our study represents a novel strategy by direct induction of hepatocyte-like cells from MSCs.

  18. A characterization of the ZFL cell line and primary hepatocytes as in vitro liver cell models for the zebrafish (Danio rerio)

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Marta, E-mail: marta.eide@bio.uib.no [Department of Biology, University of Bergen, Bergen (Norway); Rusten, Marte; Male, Rune [Department of Molecular Biology, University of Bergen, Bergen (Norway); Jensen, Knut Helge Midtbø; Goksøyr, Anders [Department of Biology, University of Bergen, Bergen (Norway)

    2014-02-15

    Highlights: •The ZFL cell line and primary hepatocytes were characterized. •Basic and induced expression of nuclear receptors and target genes were found. •The ZFL cell line expresses very low basic levels of most genes. •The ZFL cells have low induction of gene expression following exposures. •Primary hepatocytes show large sex-dependent differences in gene expression. -- Abstract: The zebrafish (Danio rerio) is a widely used model species in biomedical research. The ZFL cell line, established from zebrafish liver, and freshly isolated primary hepatocytes from zebrafish have been used in several toxicological studies. However, no previous report has compared and characterized these two systems at the level of gene expression. The aim of this study was to evaluate the ZFL cell line in comparison to primary hepatocytes as in vitro models for studying effects of environmental contaminants in zebrafish liver. Using quantitative real-time PCR, the basal level and transcriptional induction potential of key genes involved in toxic responses in the ZFL cell line, primary hepatocytes and whole liver from zebrafish were compared. The study showed that the ZFL cells have lower levels of mRNA of most selected genes compared to zebrafish liver. The induced gene transcription following exposure to ligand was much lower in ZFL cells compared to zebrafish primary hepatocytes at the doses tested. Importantly, oestrogen receptor and vitellogenin genes showed low basal transcription and no induction response in the ZFL cell line. In conclusion, it appears that primary hepatocytes are well suited for studying environmental contaminants including xenoestrogens, but may show large sex-dependent differences in gene transcription. The ZFL cell line shows potential in toxicological studies involving the aryl hydrocarbon receptor pathway. However, low potential for transcriptional induction of genes in general should be expected, especially notable when studying estrogenic

  19. Metabolism of para-aminophenol by rat hepatocytes.

    Science.gov (United States)

    Yan, Z; Nikelly, J G; Killmer, L; Tarloff, J B

    2000-08-01

    Autoxidation of para-aminophenol (PAP) has been proposed to account for the selective nephrotoxicity of this compound. However, other studies suggest that hepatic metabolites of PAP rather than the parent compound may be responsible for renal damage. These studies were designed to investigate PAP metabolism in isolated hepatocytes. We synthesized several proposed metabolites for analysis by HPLC/mass spectrometry and compared those results with HPLC/mass spectrometric analyses of metabolites found after incubating hepatocytes with PAP. Hepatocytes prepared from male Sprague-Dawley rats were incubated in Krebs-Henseleit buffer at 37 degrees C for 5 h with 2.3 mM PAP under an atmosphere of 5% CO2/95% O2. Aliquots were withdrawn at 0.1 h of incubation and then hourly through 5 h of incubation. Reactions were terminated by the addition of acetonitrile. Hepatocyte viability was unaltered with PAP present in the incubation medium. We found that hepatocytes converted PAP to two major metabolites (PAP-GSH conjugates and PAP-N-acetylcysteine conjugates) and several minor metabolites [PAP-O-glucuronide, acetaminophen (APAP), APAP-O-glucuronide, APAP-GSH conjugates, and 4-hydroxyformanilide]. Preincubating hepatoyctes with 1-aminobenzotriazole, an inhibitor of cytochromes P450, did not alter the pattern of PAP metabolism. In conclusion, we found that PAP was metabolized in hepatocytes predominantly to PAP-GSH conjugates and PAP-N-acetylcysteine conjugates in sufficient quantities to account for the nephrotoxicity of PAP.

  20. Hepatocyte polyploidization and its association with pathophysiological processes.

    Science.gov (United States)

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-05-18

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as much as 90% of the hepatocytes in mice and 40% in humans. Hepatocyte polyploidization is generally considered an indicator of terminal differentiation and cellular senescence, and related to the dysfunction of insulin and p53/p21 signaling pathways. Interestingly, the high prevalence of hepatocyte polyploidization in the aged mouse liver can be reversed when the senescent hepatocytes are serially transplanted into young mouse livers. Here we review the current knowledge on the mechanism of hepatocytes polyploidization during postnatal growth, aging, and liver diseases. The biologic significance of polyploidization in senescent reversal, within the context of new ways to think of liver aging and liver diseases is considered.

  1. Functional assessment of hepatocytes after transplantation into rat spleen

    International Nuclear Information System (INIS)

    Woods, R.J.; Fuller, B.J.; Attenburrow, V.D.; Nutt, L.H.; Hobbs, K.E.

    1982-01-01

    The retention of structural integrity and metabolic function by isolated hepatocytes after ectopic transplantation has been investigated in autografted rats. Rats were partially hepatectomized and isolated hepatocytes prepared from the excised liver lobes were implanted into their spleens. Histological examination of the spleens 7 or more weeks after implantation revealed aggregates of hepatocytes in the red pulp. Two tests of biochemical function were applied to the hepatocytes after transplantation. In the first the hepatobiliary imaging agent technetium-99m N-[N'-(2, 6-dimethylphenyl)carbamoylmethyl]iminodiacetic acid (99mTc HIDA), which was shown to be avidly taken up by isolated hepatocytes in vitro, was infused into the tail veins of autograft and control rats. Radioactivity accumulating in the spleens of autografted rats was markedly greater than that in controls implanted with lethally damaged cells or in nontransplanted rats. In the second the presence of bilirubin metabolites was sought in autograft spleens after intravenous infusion of bilirubin. Both mono- and diglucuronides of bilirubin were recovered from the spleens of autograft rats but no conjugates were recovered from the spleens of unoperated controls. We conclude that after autotransplantation isolated hepatocytes retain their morphology and at least some of their functional activities

  2. alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

    Directory of Open Access Journals (Sweden)

    Adam Szelag

    2010-06-01

    Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

  3. Nuclear

    International Nuclear Information System (INIS)

    2014-01-01

    This document proposes a presentation and discussion of the main notions, issues, principles, or characteristics related to nuclear energy: radioactivity (presence in the environment, explanation, measurement, periods and activities, low doses, applications), fuel cycle (front end, mining and ore concentration, refining and conversion, fuel fabrication, in the reactor, back end with reprocessing and recycling, transport), the future of the thorium-based fuel cycle (motivations, benefits and drawbacks), nuclear reactors (principles of fission reactors, reactor types, PWR reactors, BWR, heavy-water reactor, high temperature reactor of HTR, future reactors), nuclear wastes (classification, packaging and storage, legal aspects, vitrification, choice of a deep storage option, quantities and costs, foreign practices), radioactive releases of nuclear installations (main released radio-elements, radioactive releases by nuclear reactors and by La Hague plant, gaseous and liquid effluents, impact of releases, regulation), the OSPAR Convention, management and safety of nuclear activities (from control to quality insurance, to quality management and to sustainable development), national safety bodies (mission, means, organisation and activities of ASN, IRSN, HCTISN), international bodies, nuclear and medicine (applications of radioactivity, medical imagery, radiotherapy, doses in nuclear medicine, implementation, the accident in Epinal), nuclear and R and D (past R and D programmes and expenses, main actors in France and present funding, main R and D axis, international cooperation)

  4. Protective role of Urtica dioica L. (Urticaceae) extract on hepatocytes morphometric changes in STZ diabetic Wistar rats.

    Science.gov (United States)

    Golalipour, Mohammad Jafar; Ghafari, Soraya; Afshar, Mohammad

    2010-09-01

    The present investigation was carried out to evaluate the protective effect of the hydroalcoholic extract of Urtica dioica leaves on the quantitative morphometric changes in the liver of streptozotocin-induced diabetic rats. Thirty male Wistar rats were divided into control (G1), diabetic (G2), diabetic + Urtica dioica (G3) groups. The control group received only sham injections of intraperitoneal saline; the diabetic group received intraperitoneal saline for 5 days followed by streptozotocin (80 mg/kg) on the 6th day; and the diabetic + Urtica dioica group received 100 mg/kg Urtica dioica intraperitoneal (7) injections for 5 days and streptozotocin injection on the 6th day. After five weeks, the animals were sacrificed and whole livers removed. Liver specimens were used for quantitative morphometric analysis after hematoxylin and eosin staining. All data were statistically analyzed by one-way ANOVA and expressed as the mean with standard error of means. In the G3 (diabetic + Urtica diocia) group, the mean surface area of hepatocytes in the periportal zone (Z1) was greater than in G2 (diabetic) and G1 (control) groups, but this difference was not significant. No alteration was observed in the surface area of hepatocytes in the perivenous zone (Z3) in the diabetic + Urtica dioica (G3) group compared to the diabetic (G2) group. The mean nuclear area of hepatocytes of the rats in the diabetic + Urtica dioica (G3) group was higher in Z1 and lower in Z3 than that of rats in the diabetic (G2) group. The mean diameter of hepatocyte nuclei in the diabetic + Urtica dioica (G3) group was lower than that of diabetic (G2) and control (G1) groups in both Z1 and Z3. This study revealed that the administration of extract of Urtica dioica leaves before induction of diabetic with streptozotocin has a protective effect on the morphometric alterations of hepatocytes in the periportal and perivenous zones of the liver lobule in rats.

  5. Fuel Temperature Coefficient of Reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Loewe, W.E.

    2001-07-31

    A method for measuring the fuel temperature coefficient of reactivity in a heterogeneous nuclear reactor is presented. The method, which is used during normal operation, requires that calibrated control rods be oscillated in a special way at a high reactor power level. The value of the fuel temperature coefficient of reactivity is found from the measured flux responses to these oscillations. Application of the method in a Savannah River reactor charged with natural uranium is discussed.

  6. Uptake and disposition of mirex in hepatocytes and subcellular fractions in CD1 mouse liver

    International Nuclear Information System (INIS)

    Charles, A.K.; Rosenbaum, D.P.; Ashok, L.; Abraham, R.

    1985-01-01

    In vivo uptake and disposition of [ 14 C]mirex by CD1 mouse liver subcellular fractions and cells of different nuclear ploidy were examined following single or multiple doses of mirex injected intraperitoneally. Significant amounts of mirex were rapidly taken up by liver (21-29%), suggesting that liver is one of the primary sites of accumulation of the chemical. Among subcellular fractions, mirex was predominantly distributed in mitochondria and microsomes in the irreversibly bound form (about 20%), although its levels fluctuated considerably with time. Mirex was completely dissociated with trichloroacetic acid treatment from both nuclear and plasma membrane fractions, although the total uptake by these fractions was markedly high. The time course of uptake and concentration-dependent disposition of mirex revealed that polyploid hepatocytes selectively accumulated higher amounts of the chemical (two to three times) compared to diploid hepatocytes. The increased affinity of polyploid cells to mirex may indicate a greater susceptibility of this cell type to the chemical insult and also may suggest a possible early involvement of polyploids in the tumorigenic process in rodent livers

  7. The neuronal nitric oxide synthase inhibitor NANT blocks acetaminophen toxicity and protein nitration in freshly isolated hepatocytes.

    Science.gov (United States)

    Banerjee, Sudip; Melnyk, Stepan B; Krager, Kimberly J; Aykin-Burns, Nukhet; Letzig, Lynda G; James, Laura P; Hinson, Jack A

    2015-12-01

    3-Nitrotyrosine (3NT) in liver proteins of mice treated with hepatotoxic doses of acetaminophen (APAP) has been postulated to be causative in toxicity. Nitration is by a reactive nitrogen species formed from nitric oxide (NO). The source of the NO is unclear. iNOS knockout mice were previously found to be equally susceptible to APAP toxicity as wildtype mice and iNOS inhibitors did not decrease toxicity in mice or in hepatocytes. In this work we examined the potential role of nNOS in APAP toxicity in hepatocytes using the specific nNOS inhibitor NANT (10 µM)(N-[(4S)-4-amino-5-[(2-aminoethyl)amino]pentyl]-N'-nitroguanidinetris (trifluoroacetate)). Primary hepatocytes (1 million/ml) from male B6C3F1 mice were incubated with APAP (1mM). Cells were removed and assayed spectrofluorometrically for reactive nitrogen and oxygen species using diaminofluorescein (DAF) and Mitosox red, respectively. Cytotoxicity was determined by LDH release into media. Glutathione (GSH, GSSG), 3NT, GSNO, acetaminophen-cysteine adducts, NAD, and NADH were measured by HPLC. APAP significantly increased cytotoxicity at 1.5-3.0 h. The increase was blocked by NANT. NANT did not alter APAP mediated GSH depletion or acetaminophen-cysteine adducts in proteins which indicated that NANT did not inhibit metabolism. APAP significantly increased spectroflurometric evidence of reactive nitrogen and oxygen formation at 0.5 and 1.0 h, respectively, and increased 3NT and GSNO at 1.5-3.0 h. These increases were blocked by NANT. APAP dramatically increased NADH from 0.5-3.0 h and this increase was blocked by NANT. Also, APAP decreased the Oxygen Consumption Rate (OCR), decreased ATP production, and caused a loss of mitochondrial membrane potential, which were all blocked by NANT. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Oxidative stress, mitochondrial permeability transition, and cell death in Cu-exposed trout hepatocytes

    International Nuclear Information System (INIS)

    Krumschnabel, Gerhard; Manzl, Claudia; Berger, Christian; Hofer, Bettina

    2005-01-01

    We have previously shown that, in trout hepatocytes, exposure to a high dose of copper (Cu) leads to disruption of Ca 2+ homeostasis and elevated formation of reactive oxygen species (ROS), with the latter ultimately causing cell death. In the present study, we aimed at identifying, using a lower Cu concentration, the role of mitochondria in this scenario, the potential involvement of the mitochondrial permeability transition (MPT), and the mode of cell death induced by the metal. Incubation with 10 μM Cu resulted in a strong stimulation of ROS formation, and after 2 h of exposure a significant increase of both apoptotic and necrotic cells was seen. Co-incubation of Cu-treated hepatocytes with the iron-chelator deferoxamine significantly inhibited ROS production and completely prevented cell death. The origin of the radicals generated was at least partly mitochondrial, as visualized by confocal laser scanning microscopy. Furthermore, ROS production was diminished by inhibition of mitochondrial respiration, but since this also aggravated the elevation of intracellular Ca 2+ induced by Cu, it did not preserve cell viability. In a sub-population of cells, Cu induced a decrease of mitochondrial membrane potential and occurrence of the MPT. Cyclosporin A, which did not inhibit ROS formation, prevented the onset of the MPT and inhibited apoptotic, but not necrotic, cell death. Cu-induced apoptosis therefore appears to be dependent on induction of the MPT, but the prominent contribution of mitochondria to ROS generation also suggests an important role of mitochondria in necrotic cell death

  9. Force spectroscopy of hepatocytic extracellular matrix components

    Energy Technology Data Exchange (ETDEWEB)

    Yongsunthon, R., E-mail: YongsuntR@Corning.com [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States); Baker, W.A.; Bryhan, M.D.; Baker, D.E.; Chang, T.; Petzold, O.N.; Walczak, W.J.; Liu, J.; Faris, R.A.; Senaratne, W.; Seeley, L.A.; Youngman, R.E. [Corning Incorporated, SP-FR-01, R1S32D, Corning, NY 14831 (United States)

    2009-07-15

    We present atomic force microscopy and force spectroscopy data of live hepatocytes (HEPG2/C3A liver cell line) grown in Eagle's Minimum Essential Medium, a complex solution of salts and amino acids commonly used for cell culture. Contact-mode imaging and force spectroscopy of this system allowed correlation of cell morphology and extracellular matrix (ECM) properties with substrate properties. Force spectroscopy analysis of cellular 'footprints' indicated that the cells secrete large polymers (e.g., 3.5 {mu}m contour length and estimated MW 1000 kDa) onto their substrate surface. Although definitive identification of the polymers has not yet been achieved, fluorescent-labeled antibody staining has specified the presence of ECM proteins such as collagen and laminin in the cellular footprints. The stretched polymers appear to be much larger than single molecules of known ECM components, such as collagen and heparan sulfate proteoglycan, thus suggesting that the cells create larger entangled, macromolecular structures from smaller components. There is strong evidence which suggests that the composition of the ECM is greatly influenced by the hydrophobicity of the substrate surface, with preferential production and/or adsorption of larger macromolecules on hydrophobic surfaces.

  10. Evidence for the role of oxidative stress in the acetylation of histone H3 by ethanol in rat hepatocytes

    Science.gov (United States)

    Choudhury, Mahua; Park, Pil-Hoon; Jackson, Daniel; Shukla, Shivendra D.

    2010-01-01

    The relationship between ethanol induced oxidative stress and acetylation of histone H3 at lysine 9 (H3AcK9) remains unknown and was therefore investigated in primary cultures of rat hepatocytes. Cells were treated with ethanol and a select group of pharmacological agents and the status of H3AcK9 and reactive oxygen species (ROS) were monitored. When hepatocytes were exposed to ethanol (50 mM, 24 hr) in the presence of N-acetyl cystein (ROS reducer) or dietary antioxidants (quercetin, resveratrol), or NADPH oxidase inhibitor apocynin, ethanol induced increases in ROS and H3AcK9, both were significantly reduced. On the other hand, l-buthionine-sulfoximine (ROS inducer) and inhibitor of mitochondrial complex I (rotenone) and III (antimycin) increased ethanol induced H3AcK9 (p<0.01). Oxidative stress also affected ethanol induced alcohol dehydrogenase 1 (ADH1) mRNA expression. These results demonstrate for the first time that oxidative stress is involved in the ethanol induced histone H3 acetylation in hepatocytes. PMID:20705415

  11. Role of macrophages in the immune response to hepatocytes

    International Nuclear Information System (INIS)

    Bumgardner, G.L.; Chen, S.; Almond, S.P.; Ascher, N.L.; Payne, W.D.; Matas, A.J.

    1990-01-01

    The purpose of this study was to determine the role of host macrophages in the development of allospecific cytolytic T cells (allo-CTLs) in response to purified allogeneic MHC Class I+, Class II- hepatocytes in vivo in hepatocyte sponge matrix allografts (HC-SMA). Depletion of antigen-presenting cells (APCs) from responder splenocytes in mixed lymphocyte hepatocyte culture (MLHC) inhibits the development of allo-CTLs in response to purified hepatocytes. First the ability of sponge macrophages to function as accessory cells in indirect presentation of hepatocyte Class I antigen was tested in MLHC. We found that addition of irradiated sponge cells (a source of sponge macrophages) restored the development of allo-CTLs in MLHC depleted of responder APCs. Therefore, radioresistant sponge macrophages can function as accessory cells in MLHC. We next employed silica as an immunotherapy targeted against host macrophages and assessed the effect on development of allo-CTLs in HC-SMA. We found that local (intrasponge) silica treatment completely inhibited the development of allo-CTLs in HC-SMA. Combined local and systemic silica treatment resulted in inhibition of allocytotoxicity comparable to local silica treatment alone in the doses tested. We conclude that host macrophages which infiltrate HC-SMA can function as accessory cells in vitro in MLHC and that both infiltrating host macrophages and lymphocytes participate in the development of an alloimmune response to purified hepatocytes in vivo. This interaction may involve indirect antigen presentation of hepatocyte Class I antigen by macrophages to host lymphocytes which accumulate in HC-SMA

  12. Effects of edaravone, a radical scavenger, on hepatocyte transplantation.

    Science.gov (United States)

    Hayashi, Chihiro; Ito, Masahiro; Ito, Ryoutaro; Murakumo, Akiko; Yamamoto, Naoki; Hiramatsu, Noriko; Fox, Ira J; Horiguchi, Akihiko

    2014-12-01

    Hepatocyte transplantation (HTx) has yielded significant improvements in liver function and survival in experimentally induced acute liver failure and liver-based metabolic disease. However, transplantation is inefficient, and it is thought that transplanted hepatocytes have a shortened lifespan because of inflammation involving excess nitric oxide (NO). The present study aimed to clarify whether edaravone, a free radical scavenger used to treat ischemic stroke, could reduce ischemic changes in hepatocyte-transplanted livers. Edaravone (3 mg/kg) was administered intravenously 24 h before HTx to Nagase analbuminemic rats (NARs). Hepatocytes were isolated, and 30 × 10(6) cells were injected in a 1.0-ml volume directly into the spleens of NARs. All experimental groups studied received FK506 to control rejection. Animals in Group A received medium-only; Group B received HTx only; and Group C received HTx and edaravone. Forty-eight hours after transplantation, the hepatocytes from animals were isolated and analyzed for staining with propidium iodide- and annexin-V using flow cytometry. Liver sections were also studied by immunostaining for albumin, and TUNEL. Peripheral blood serum albumin levels were measured on post-transplant days 0, 3, 5, 7, 10 and 14 using ELISA. The edaravone-treated animals demonstrated an increased number of engrafted donor hepatocytes in the liver. The edaravone-treated liver sections also contained fewer TUNEL-positive cells and animals that received edaravone had higher serum albumin levels post-transplantation. Hepatocytes were also found to have increased in numbers 2 weeks following treatment with edaravone. Edaravone administration during HTx can suppress apoptosis near the transplanted cells, increasing engraftment. These studies indicate its potential usefulness for future clinical application. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  13. Water and nonelectrolyte permeability of isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Alpini, G.; Garrick, R.A.; Jones, M.J.; Nunes, R.; Tavoloni, N.

    1986-01-01

    We have measured the diffusive permeability coefficients of isolated rat hepatocytes to 3 H 2 O, [ 14 C]urea, [ 14 C]erythritol, [ 14 C]mannitol, [ 3 H]sucrose, and [ 3 H]inulin, employing a technique previously developed for erythrocytes (Redwood et al., J. Gen. Physiol 64:706-729, 1974). Diffusion coefficients for the tracer molecules were measured in packed hepatocytes, supernatant fluid, and intracellular medium (lysed hepatocytes) and were calculated assuming one-dimensional semi-infinite diffusion through a homogeneous medium. By applying the series-parallel pathway model, the following permeability coefficients (10(-5) cm/sec) for the hepatocyte plasma membrane were obtained. 3 H 2 O, 98.6 +/- 18.4; [ 14 C]urea, 18.2 +/- 5.3; [ 14 C]erythritol, 4.8 +/- 1.6; [ 14 C]mannitol, 3.1 +/- 1.4; [ 3 H]sucrose, 0; [ 3 H]inulin, 0. These results indicate that isolated rat hepatocytes are highly permeable to water and polar nonelectrolytes, when compared with other transporting epithelia. This relatively high cellular permeability is consistent with a model in which nonelectrolyte permeation is via an aqueous pathway of equivalent pore diameter of 8-12 A. The finding that [ 14 C]erythritol and [ 14 C]mannitol cross the hepatocyte plasma membrane indicates that these molecules enter the bile canaliculus through the transcellular route. Conversely, the failure of [ 3 H]sucrose and [ 3 H]inulin to permeate the hepatocyte in the isolated condition supports the concept that biliary entry of these large carbohydrates, at least that fraction which cannot be accounted for by a vesicular mechanism, must occur via the transjunctional shunt pathway

  14. Hepatocyte-specific deletion of the keap1 gene activates Nrf2 and confers potent resistance against acute drug toxicity

    International Nuclear Information System (INIS)

    Okawa, Hiromi; Motohashi, Hozumi; Kobayashi, Akira; Aburatani, Hiroyuki; Kensler, Thomas W.; Yamamoto, Masayuki

    2006-01-01

    Nrf2 is a key regulator of many detoxifying enzyme genes, and cytoplasmic protein Keap1 represses the Nrf2 activity under quiescent conditions. Germ line deletion of the keap1 gene results in constitutive activation of Nrf2, but the pups unexpectedly died before weaning. To investigate how constitutive activation of Nrf2 influences the detoxification system in adult mice, we generated mice bearing a hepatocyte-specific disruption of the keap1 gene. Homozygous mice were viable and their livers displayed no apparent abnormalities, but nuclear accumulation of Nrf2 is elevated. Microarray analysis revealed that, while many detoxifying enzyme genes are highly expressed, some of the typical Nrf2-dependent genes are only marginally increased in the Keap1-deficient liver. The mutant mice were significantly more resistant to toxic doses of acetaminophen than control animals. These results demonstrate that chronic activation of Nrf2 confers animals with resistance to xenobiotics without affecting the morphological and physiological integrity of hepatocytes

  15. Hepatocyte oxidant stress and alcoholic liver disease

    NARCIS (Netherlands)

    Conde de la Rosa, L.; Moshage, H.; Nieto, N.

    Acute and chronic alcohol consumption increases the production of reactive oxygen species (ROS), and enhances lipid peroxidation of lipids, proteins, and DNA. The mechanism by which alcohol causes cell injury is still not clear but a major role for ROS and lipid peroxidation-end products is

  16. Menadione-induced DNA fragmentation without 8-oxo-2'-deoxyguanosine formation in isolated rat hepatocytes

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Corcoran, G B; Poulsen, H E

    1995-01-01

    Menadione (2-methyl-1,4-naphthoquinone) induces oxidative stress in cells causing perturbations in the cytoplasm as well as nicking of DNA. The mechanisms by which DNA damage occurs are still unclear, but a widely discussed issue is whether menadione-generated reactive oxygen species (ROS) directly...... damage DNA. In the present study, we measured the effect of menadione on formation of 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodG), an index of oxidative DNA base modifications, and on DNA fragmentation. Isolated hepatocytes from phenobarbital-pretreated rats were exposed to menadione, 25-400 micro......M, for 15, 90 or 180 min with or without prior depletion of reduced glutathione (GSH) by diethyl maleate. Menadione caused profound GSH depletion and internucleosomal DNA fragmentation, which was demonstrated by a prominent fragmentation ladder on agarose gel electrophoresis. We found no oxidative...

  17. Synergistic Effect of Radiation and Interleukin-6 on Hepatitis B Virus Reactivation in Liver Through STAT3 Signaling Pathway

    International Nuclear Information System (INIS)

    Chou, C.H.; Chen, P.-J.; Jeng, Y.-M.; Cheng, A.-L.; Huang, L.-R.; Cheng, J.C.-H.

    2009-01-01

    Purpose: Hepatitis B virus (HBV) reactivation can occur after radiotherapy (RT) for hepatobiliary malignancies. Our previous in vitro culture study identified interleukin-6 (IL-6) as the main bystander mediator of RT-induced HBV replication. We attempted to examine the molecular mechanism in HBV-transgenic mice. Methods and materials: HBV transgenic mice were treated with whole liver RT (4 Gy daily for 5 days) with or without administration of IL-6 (400 ng twice daily for 15 days). The serum level of HBV DNA was measured using real-time polymerase chain reaction, and the IL-6 concentration was measured using enzyme-linked immunosorbent assay. The intensity of immunostaining with antibodies to HBV core protein and phosphorylated signal transducer and activator of transcription (STAT)3 in the mouse liver was qualitatively analyzed. HepG2.2.15 cells (a human hepatoblastoma cell line that persistently produces HBV DNA) were used to investigate the molecular role of IL-6 plus RT in HBV reactivation. Results: HBV reactivation was induced in vivo with IL-6 plus RT (5.58-fold) compared with RT alone (1.31-fold, p = .005), IL-6 alone (1.31-fold, p = .005), or sham treatment (1.22-fold, p = .004). HBV core protein staining confirmed augmentation of intrahepatic HBV replication. IL-6 plus RT-induced HBV DNA replication in HepG2.2.15 cells was suppressed by the STAT3 inhibitor AG490 and by transfection with dominant-negative STAT3 plasmid. Phosphorylated STAT3 staining was strongest in liver tissue from mice treated with IL-6 plus RT. The mobility shift assay demonstrated that reactivation was mediated through the interaction of phosphorylated STAT3/hepatocyte nuclear factor-3 complex with HBV enhancer 1. Conclusion: RT to the liver and longer sustained IL-6 induced HBV reactivation through the STAT3 signal transduction pathway.

  18. Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane

    Science.gov (United States)

    Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F

    2000-01-01

    BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack.
METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum.
RESULTS—Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes.
CONCLUSIONS—AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.


Keywords: liver/kidney microsomal antibody type 1; autoimmunity; autoimmune hepatitis; hepatitis C virus infection; confocal microscopy PMID:10716687

  19. Hepatocyte specific expression of human cloned genes

    Energy Technology Data Exchange (ETDEWEB)

    Cortese, R

    1986-01-01

    A large number of proteins are specifically synthesized in the hepatocyte. Only the adult liver expresses the complete repertoire of functions which are required at various stages during development. There is therefore a complex series of regulatory mechanisms responsible for the maintenance of the differentiated state and for the developmental and physiological variations in the pattern of gene expression. Human hepatoma cell lines HepG2 and Hep3B display a pattern of gene expression similar to adult and fetal liver, respectively; in contrast, cultured fibroblasts or HeLa cells do not express most of the liver specific genes. They have used these cell lines for transfection experiments with cloned human liver specific genes. DNA segments coding for alpha1-antitrypsin and retinol binding protein (two proteins synthesized both in fetal and adult liver) are expressed in the hepatoma cell lines HepG2 and Hep3B, but not in HeLa cells or fibroblasts. A DNA segment coding for haptoglobin (a protein synthesized only after birth) is only expressed in the hepatoma cell line HepG2 but not in Hep3B nor in non hepatic cell lines. The information for tissue specific expression is located in the 5' flanking region of all three genes. In vivo competition experiments show that these DNA segments bind to a common, apparently limiting, transacting factor. Conventional techniques (Bal deletions, site directed mutagenesis, etc.) have been used to precisely identify the DNA sequences responsible for these effects. The emerging picture is complex: they have identified multiple, separate transcriptional signals, essential for maximal promoter activation and tissue specific expression. Some of these signals show a negative effect on transcription in fibroblast cell lines.

  20. Citrus nobiletin suppresses inducible nitric oxide synthase gene expression in interleukin-1β-treated hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshigai, Emi [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Machida, Toru [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okuyama, Tetsuya [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Mori, Masatoshi; Murase, Hiromitsu; Yamanishi, Ryota [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan); Okumura, Tadayoshi [Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga (Japan); Department of Surgery, Kansai Medical University, Hirakata, Osaka (Japan); Ikeya, Yukinobu [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga (Japan); Nishino, Hoyoku [Ritsumeikan Global Innovation Research Organization (R-GIRO), Kusatsu, Shiga (Japan); Department of Biochemistry, Kyoto Prefectural University of Medicine, Kyoto (Japan); Nishizawa, Mikio, E-mail: nishizaw@sk.ritsumei.ac.jp [Department of Biomedical Sciences, College of Life Sciences, Kusatsu, Shiga (Japan)

    2013-09-13

    Highlights: •Nobiletin is a polymethoxylated flavone that is abundant in citrus peels. •Nobiletin is a major constituent of the Citrus unshiu peel extract. •Nobiletin suppresses induction of NO and reduces iNOS expression in hepatocytes. •Nobiletin reduces the iNOS promoter activity and the DNA-binding activity of NF-κB. -- Abstract: Background: Nobiletin is a polymethoxylated flavone that is abundant in the peels of citrus fruits, such as Citrus unshiu (Satsuma mandarin) and Citrus sinensis. The dried peels of C. unshiu (chinpi) have been included in several formulae of Japanese Kampo medicines. Nobiletin may suppress the induction of inducible nitric oxide synthase (iNOS), which synthesizes the inflammatory mediator nitric oxide (NO) in hepatocytes. Methods: A C. unshiu peel (CUP) extract was prepared. Primary cultured rat hepatocytes were treated with the CUP extract or nobiletin in the presence of interleukin 1β (IL-1β), which induces iNOS expression. NO production and iNOS gene expression were analyzed. Results: High-performance liquid chromatography analyses revealed that the nobiletin content in the CUP extract was 0.14%. Nobiletin dose-dependently reduced the NO levels and decreased iNOS expression at the protein, mRNA and antisense transcript levels. Flavone, which does not contain any methoxy groups, also suppressed iNOS induction. Nobiletin reduced the transcriptional activity of iNOS promoter-luciferase constructs and the DNA-binding activity of nuclear factor κB (NF-κB) in the nuclei. Conclusions: The suppression of iNOS induction by nobiletin suggests that nobiletin may be responsible for the anti-inflammatory effects of citrus peels and have a therapeutic potential for liver diseases.

  1. Regarding KUR Reactivity Measurement System

    International Nuclear Information System (INIS)

    Nakamori, Akira; Hasegawa, Kei; Tsuchiyama, Tatsuo; Yamamoto, Toshihiro; Okumura, Ryo; Sano, Tadafumi

    2012-01-01

    This article reported: (1) the outline of the reactivity measurement system of Kyoto University Research Reactor (KUR), (2) the calibration data of control rod, (3) the problems and the countermeasures for range switching of linear output meter. For the laptop PC for the reactivity measurement system, there are four input signals: (1) linear output meter, (2) logarithmic output meter, (3) core temperature gauge, and (4) control rod position. The hardware of reactivity measurement system is controlled with Labview installed on the laptop. Output, reactivity, reactor period, and the change in reactivity due to temperature effect or Xenon effect are internally calculated and displayed in real-time with Labview based on the four signals above. Calculation results are recorded in the form of a spreadsheet. At KUR, the reactor core arrangement was changed, so the control rod was re-calibrated. At this time, calculated and experimental values of reactivity based on the reactivity measurement system were compared, and it was confirmed that the reactivity calculation by Labview was accurate. The range switching of linear output meter in the nuclear instrumentation should automatically change within the laptop, however sometimes this did not function properly in the early stage. It was speculated that undefined percent values during the transition of percent value were included in the calculation and caused calculation errors. The range switching started working properly after fixing this issue. (S.K.)

  2. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  3. A refined characterisation of the NeoHepatocyte phenotype necessitates a reappraisal of the transdifferentiation hypothesis.

    Science.gov (United States)

    Riquelme, Paloma; Wundt, Judith; Hutchinson, James A; Brulport, Marc; Jun, Yu; Sotnikova, Anna; Girreser, Ulrich; Braun, Felix; Gövert, Felix; Soria, Bernat; Nüssler, Andreas; Clement, Bernd; Hengstler, Jan G; Fändrich, Fred

    2009-03-01

    Under certain culture conditions human peripheral blood monocytes may be induced to express phenotypic markers of non-haematopoietic lineages, including hepatocyte-defining traits. One such example, the NeoHepatocyte, was previously shown to express a broad panel of hepatocyte-like marker antigens and metabolic activities, both in vitro and following engraftment in the liver of immunodeficient mice. In this report, a refined description of NeoHepatocytes, with regard to their expression of xenobiotic-metabolising enzymes, morphology, hepatocyte marker expression and cell surface phenotype, is presented in comparison with human macrophages in defined states of activation. Contrary to prior assertions, it would seem more likely that NeoHepatocytes express particular hepatocyte-defining genes during a normal programme of macrophage differentiation rather than undergoing a process of transdifferentiation to become hepatocyte-like cells.

  4. Determination of metabolic stability using cryopreserved hepatocytes from rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Standard protocols for isolating, cryopreserving, and thawing rainbow trout hepatocytes are described, along with procedures for using fresh or cryopreserved hepatocytes to assess chemical metabolic stability in fish by means of a substrate depletion approach. Variations on thes...

  5. Alternative Cell Sources to Adult Hepatocytes for Hepatic Cell Therapy.

    Science.gov (United States)

    Pareja, Eugenia; Gómez-Lechón, María José; Tolosa, Laia

    2017-01-01

    Adult hepatocyte transplantation is limited by scarce availability of suitable donor liver tissue for hepatocyte isolation. New cell-based therapies are being developed to supplement whole-organ liver transplantation, to reduce the waiting-list mortality rate, and to obtain more sustained and significant metabolic correction. Fetal livers and unsuitable neonatal livers for organ transplantation have been proposed as potential useful sources of hepatic cells for cell therapy. However, the major challenge is to use alternative cell sources for transplantation that can be derived from reproducible methods. Different types of stem cells with hepatic differentiation potential are eligible for generating large numbers of functional hepatocytes for liver cell therapy to treat degenerative disorders, inborn hepatic metabolic diseases, and organ failure. Clinical trials are designed to fully establish the safety profile of such therapies and to define target patient groups and standardized protocols.

  6. Biogeochemical reactive-transport modelling of the interactions of medium activity long-lived nuclear waste in fractured argillite and the effect on redox conditions

    International Nuclear Information System (INIS)

    Small, J.S.; Steele, H.; Kwong, S.; Albrecht, A.

    2010-01-01

    Document available in extended abstract form only. The role of anaerobic microbial processes in mediating gas generation and redox reactions in organic (cellulose) containing low level activity nuclear wastes (LLW) is well established through monitoring of operational near-surface LLW disposal sites and municipal waste disposal sites. Modelling approaches based on Monod kinetic growth models to represent the complex suite of anaerobic processes have been developed and these models are able to reproduce the evolving biogeochemistry and gas generation of large scale and long term (10 year) experiments on cellulose waste degradation. In the case of geological disposal of medium activity long-lived nuclear waste (MAVL) microbial processes have the potential to exploit metabolic energy sources present in the waste, engineered barriers and host geological formation and as a consequence influence redox potential. Several electron donors and electron acceptors may be present in MAVL. Electron donors include; hydrogen (resulting from radiolysis and anaerobic corrosion of metals), and hydrolysis products of organic waste materials. Sulphate, nitrate and Fe(III) containing minerals and corrosion products are examples of electron acceptors present in intermediate level wastes. Significant amounts of organic matter, sulphate and iron minerals may also be present in host geological formations and have the potential to act as microbial energy sources once the system is perturbed by electron donors/acceptors from the waste. The construction of a geological disposal facility will physically disturb the host formation, potentially causing fracturing of the excavation damage zone (EDZ). The EDZ may thus provide environmental conditions, such as space and free water that together with nutrient and energy sources to promote microbial activity. In this study the Generalised Repository Model (GRM) developed to simulate the coupled microbiological, chemical and transport processes in near

  7. Property of hepatitis B virus replication in Tupaia belangeri hepatocytes.

    Science.gov (United States)

    Sanada, Takahiro; Tsukiyama-Kohara, Kyoko; Yamamoto, Naoki; Ezzikouri, Sayeh; Benjelloun, Soumaya; Murakami, Shuko; Tanaka, Yasuhito; Tateno, Chise; Kohara, Michinori

    2016-01-08

    The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3-6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10(5) copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10(4)-10(6) copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10(3) copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  8. A simple reactivity-meter system

    International Nuclear Information System (INIS)

    Ferreira, P.S.B.

    1992-01-01

    This paper describes a new version of a reactivity meter developed at the Institute of Nuclear Energy Research (IPEN) (Brazil). The reactivity meter computes the reactor reactivity utilizing a programmable electrometer that performs the data aquisition. The software commands the main functions of the electrometer, the data acquisition, data transfer, and reactivity calculation. The necessary hardware for this reactivity meter are a programmable electrometer, a microcomputer, and interfaces for the microcomputer to communicate with the electrometer. If it is necessary, it is possible to connect a graphic register to the microcomputer. With this conventional hardware, available in any nuclear reactor facility, one can build a powerful reactivity meter. Adding to these advantages, one can use the microcomputer on-line to analyze the data, store the data on diskettes, or create graphics

  9. Interspecies differences in metabolism of arsenic by cultured primary hepatocytes

    International Nuclear Information System (INIS)

    Drobna, Zuzana; Walton, Felecia S.; Harmon, Anne W.; Thomas, David J.; Styblo, Miroslav

    2010-01-01

    Biomethylation is the major pathway for the metabolism of inorganic arsenic (iAs) in many mammalian species, including the human. However, significant interspecies differences have been reported in the rate of in vivo metabolism of iAs and in yields of iAs metabolites found in urine. Liver is considered the primary site for the methylation of iAs and arsenic (+3 oxidation state) methyltransferase (As3mt) is the key enzyme in this pathway. Thus, the As3mt-catalyzed methylation of iAs in the liver determines in part the rate and the pattern of iAs metabolism in various species. We examined kinetics and concentration-response patterns for iAs methylation by cultured primary hepatocytes derived from human, rat, mice, dog, rabbit, and rhesus monkey. Hepatocytes were exposed to [ 73 As]arsenite (iAs III ; 0.3, 0.9, 3.0, 9.0 or 30 nmol As/mg protein) for 24 h and radiolabeled metabolites were analyzed in cells and culture media. Hepatocytes from all six species methylated iAs III to methylarsenic (MAs) and dimethylarsenic (DMAs). Notably, dog, rat and monkey hepatocytes were considerably more efficient methylators of iAs III than mouse, rabbit or human hepatocytes. The low efficiency of mouse, rabbit and human hepatocytes to methylate iAs III was associated with inhibition of DMAs production by moderate concentrations of iAs III and with retention of iAs and MAs in cells. No significant correlations were found between the rate of iAs methylation and the thioredoxin reductase activity or glutathione concentration, two factors that modulate the activity of recombinant As3mt. No associations between the rates of iAs methylation and As3mt protein structures were found for the six species examined. Immunoblot analyses indicate that the superior arsenic methylation capacities of dog, rat and monkey hepatocytes examined in this study may be associated with a higher As3mt expression. However, factors other than As3mt expression may also contribute to the interspecies differences

  10. Microencapsulation of Hepatocytes and Mesenchymal Stem Cells for Therapeutic Applications.

    Science.gov (United States)

    Meier, Raphael P H; Montanari, Elisa; Morel, Philippe; Pimenta, Joël; Schuurman, Henk-Jan; Wandrey, Christine; Gerber-Lemaire, Sandrine; Mahou, Redouan; Bühler, Leo H

    2017-01-01

    Encapsulated hepatocyte transplantation and encapsulated mesenchymal stem cell transplantation are newly developed potential treatments for acute and chronic liver diseases, respectively. Cells are microencapsulated in biocompatible semipermeable alginate-based hydrogels. Microspheres protect cells against antibodies and immune cells, while allowing nutrients, small/medium size proteins and drugs to diffuse inside and outside the polymer matrix. Microencapsulated cells are assessed in vitro and designed for experimental transplantation and for future clinical applications.Here, we describe the protocol for microencapsulation of hepatocytes and mesenchymal stem cells within hybrid poly(ethylene glycol)-alginate hydrogels.

  11. Inducibility of carbamoylphosphate synthetase (ammonia) in cultures of embryonic hepatocytes: ontogenesis of the responsiveness to hormones

    NARCIS (Netherlands)

    Lamers, W. H.; Zonneveld, D.; Charles, R.

    1984-01-01

    Glucocorticosteroids and cyclic AMP induce carbamoylphosphate synthetase (ammonia) (CPS) in rat hepatocytes. Using an enzyme immunoassay applied to hepatocyte cultures fixed in situ, it has been demonstrated that the capacity of hepatocytes to synthesize CPS in the presence of both hormones is

  12. File list: His.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: ALL.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Liv.20.AllAg.Hepatocytes hg19 All antigens Liver Hepatocytes SRX815538,SRX47792...RX1013893,SRX1013888,SRX1013891,SRX1013889 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Liv.20.AllAg.Hepatocytes.bed ...

  12. File list: InP.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Liv.50.AllAg.Hepatocytes mm9 Input control Liver Hepatocytes SRX019015,SRX55553...3,SRX1334843 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Liv.50.AllAg.Hepatocytes.bed ...

  13. File list: ALL.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Liv.05.AllAg.Hepatocytes hg19 All antigens Liver Hepatocytes ERX008749,SRX81553...RX1013893,SRX1013888,SRX1013889,SRX1013891 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Liv.05.AllAg.Hepatocytes.bed ...

  14. File list: InP.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Liv.20.AllAg.Hepatocytes mm9 Input control Liver Hepatocytes SRX019015,SRX13348...43,SRX555533 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Liv.20.AllAg.Hepatocytes.bed ...

  15. File list: NoD.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available NoD.Liv.05.AllAg.Hepatocytes hg19 No description Liver Hepatocytes ERX008749,SRX815...08760,ERX008728,ERX008736 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/NoD.Liv.05.AllAg.Hepatocytes.bed ...

  16. File list: InP.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Liv.50.AllAg.Hepatocytes hg19 Input control Liver Hepatocytes SRX530185,SRX5301...83 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Liv.50.AllAg.Hepatocytes.bed ...

  17. File list: Oth.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Liv.50.AllAg.Hepatocytes hg19 TFs and others Liver Hepatocytes SRX530184,SRX530...186 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Liv.50.AllAg.Hepatocytes.bed ...

  18. File list: InP.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Liv.10.AllAg.Hepatocytes mm9 Input control Liver Hepatocytes SRX019015,SRX55553...3,SRX1334843 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Liv.10.AllAg.Hepatocytes.bed ...

  19. File list: ALL.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Liv.10.AllAg.Hepatocytes hg19 All antigens Liver Hepatocytes SRX815538,SRX81553...RX1013893,SRX1013888,SRX1013889,SRX1013891 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Liv.10.AllAg.Hepatocytes.bed ...

  20. File list: ALL.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Liv.50.AllAg.Hepatocytes mm9 All antigens Liver Hepatocytes ERX113003,ERX112977...014,ERX008723 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Liv.50.AllAg.Hepatocytes.bed ...

  1. File list: ALL.Liv.50.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Liv.50.AllAg.Hepatocytes hg19 All antigens Liver Hepatocytes SRX815538,SRX47792...,SRX1013891,SRX1013889,ERX008736 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Liv.50.AllAg.Hepatocytes.bed ...

  2. File list: Pol.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Pol.Liv.10.AllAg.Hepatocytes mm9 RNA polymerase Liver Hepatocytes ERX204060,ERX2040...69,ERX204064 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Pol.Liv.10.AllAg.Hepatocytes.bed ...

  3. File list: Oth.Liv.05.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Liv.05.AllAg.Hepatocytes mm9 TFs and others Liver Hepatocytes SRX019007,SRX1169...19009,SRX116906,ERX204061,ERX204058,SRX019006,SRX555532,ERX204067,ERX204065 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/Oth.Liv.05.AllAg.Hepatocytes.bed ...

  4. File list: Oth.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.Liv.20.AllAg.Hepatocytes hg19 TFs and others Liver Hepatocytes SRX530184,SRX530...186 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Liv.20.AllAg.Hepatocytes.bed ...

  5. Nuclear

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The first text deals with a new circular concerning the collect of the medicine radioactive wastes, containing radium. This campaign wants to incite people to let go their radioactive wastes (needles, tubes) in order to suppress any danger. The second text presents a decree of the 31 december 1999, relative to the limitations of noise and external risks resulting from the nuclear facilities exploitation: noise, atmospheric pollution, water pollution, wastes management and fire prevention. (A.L.B.)

  6. Calcium-mediated signaling and calmodulin-dependent kinase regulate hepatocyte-inducible nitric oxide synthase expression.

    Science.gov (United States)

    Zhang, Baochun; Crankshaw, Will; Nesemeier, Ryan; Patel, Jay; Nweze, Ikenna; Lakshmanan, Jaganathan; Harbrecht, Brian G

    2015-02-01

    Induced nitric oxide synthase (iNOS) is induced in hepatocytes by shock and inflammatory stimuli. Excessive NO from iNOS mediates shock-induced hepatic injury and death, so understanding the regulation of iNOS will help elucidate the pathophysiology of septic shock. In vitro, cytokines induce iNOS expression through activation of signaling pathways including mitogen-activated protein kinases and nuclear factor κB. Cytokines also induce calcium (Ca(2+)) mobilization and activate calcium-mediated intracellular signaling pathways, typically through activation of calmodulin-dependent kinases (CaMK). Calcium regulates NO production in macrophages but the role of calcium and calcium-mediated signaling in hepatocyte iNOS expression has not been defined. Primary rat hepatocytes were isolated, cultured, and induced to produce NO with proinflammatory cytokines. Calcium mobilization and Ca(2+)-mediated signaling were altered with ionophore, Ca(2+) channel blockers, and inhibitors of CaMK. The Ca(2+) ionophore A23187 suppressed cytokine-stimulated NO production, whereas Ethylene glycol tetraacetic acid and nifedipine increased NO production, iNOS messenger RNA, and iNOS protein expression. Inhibition of CaMK with KN93 and CBD increased NO production but the calcineurin inhibitor FK 506 decreased iNOS expression. These data demonstrate that calcium-mediated signaling regulates hepatocyte iNOS expression and does so through a mechanism independent of calcineurin. Changes in intracellular calcium levels may regulate iNOS expression during hepatic inflammation induced by proinflammatory cytokines. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Effect of trifluoperazine on toxicity, HIF-1α induction and hepatocyte regeneration in acetaminophen toxicity in mice

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Shubhra, E-mail: SCHAUDHURI@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); McCullough, Sandra S., E-mail: mcculloughsandras@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Hennings, Leah, E-mail: lhennings@uams.edu [Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Brown, Aliza T., E-mail: brownalizat@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Li, Shun-Hwa [Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI (United States); Simpson, Pippa M., E-mail: psimpson@mcw.edu [Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI (United States); Hinson, Jack A., E-mail: hinsonjacka@uams.edu [Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); James, Laura P., E-mail: jameslaurap@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States); Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, Arkansas Children' s Hospital Research Institute, Little Rock, AR (United States)

    2012-10-15

    Oxidative stress and mitochondrial permeability transition (MPT) are important mechanisms in acetaminophen (APAP) toxicity. The MPT inhibitor trifluoperazine (TFP) reduced MPT, oxidative stress, and toxicity in freshly isolated hepatocytes treated with APAP. Since hypoxia inducible factor-one alpha (HIF-1α) is induced very early in APAP toxicity, a role for oxidative stress in the induction has been postulated. In the present study, the effect of TFP on toxicity and HIF-1α induction in B6C3F1 male mice treated with APAP was examined. Mice received TFP (10 mg/kg, oral gavage) prior to APAP (200 mg/kg IP) and at 7 and 36 h after APAP. Measures of metabolism (hepatic glutathione and APAP protein adducts) were comparable in the two groups of mice. Toxicity was decreased in the APAP/TFP mice at 2, 4, and 8 h, compared to the APAP mice. At 24 and 48 h, there were no significant differences in toxicity between the two groups. TFP lowered HIF-1α induction but also reduced the expression of proliferating cell nuclear antigen, a marker of hepatocyte regeneration. TFP can also inhibit phospholipase A{sub 2}, and cytosolic and secretory PLA{sub 2} activity levels were reduced in the APAP/TFP mice compared to the APAP mice. TFP also lowered prostaglandin E{sub 2} expression, a known mechanism of cytoprotection. In summary, the MPT inhibitor TFP delayed the onset of toxicity and lowered HIF-1α induction in APAP treated mice. TFP also reduced PGE{sub 2} expression and hepatocyte regeneration, likely through a mechanism involving PLA{sub 2}. -- Highlights: ► Trifluoperazine reduced acetaminophen toxicity and lowered HIF-1α induction. ► Trifluoperazine had no effect on the metabolism of acetaminophen. ► Trifluoperazine reduced hepatocyte regeneration. ► Trifluoperazine reduced phospholipase A{sub 2} activity and prostaglandin E{sub 2} levels.

  8. Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S., E-mail: frank.abbott@ubc.ca

    2012-11-01

    contributes to the toxicity of (E)-2-ene-VPA in PB-pretreated rat hepatocytes. -- Highlights: ► (E)-2,4-diene-valproic acid is a reactive and toxic metabolite of valproic acid (VPA). ► In situ, this metabolite is not responsible for VPA toxicity in rat hepatocytes. ► This metabolite enhances (E)-2-ene-VPA toxicity in PB-pretreated hepatocytes.

  9. Insulin infusion reduces hepatocyte growth factor in lean humans

    DEFF Research Database (Denmark)

    de Courten, Barbora; de Courten, Maximilian; Dougherty, Sonia

    2013-01-01

    OBJECTIVE: Plasma Hepatocyte Growth Factor (HGF) is significantly elevated in obesity and may contribute to vascular disease, metabolic syndrome or cancer in obese individuals. The current studies were done to determine if hyperinsulinemia increases plasma HGF. MATERIALS/METHODS: Twenty-two parti...

  10. The use of pig hepatocytes for biotransformation and toxicity studies

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.

    1991-01-01

    The three main objectives of this study were, (1) to investigate the possibility to isolate viable hepatocytes from liver samples of pigs, (2) to study their use for biotransformation and toxicity studies, and (3) to demonstrate the value of this model, in particular in the field of residue

  11. Hepatocytes in the development of liver support systems

    NARCIS (Netherlands)

    I.H.M. Borel Rinkes (Inne)

    1993-01-01

    textabstractThis thesis focuses on the development of alternative strategies in the treatment of patients with acute fulminant hepatic failure and inborn errors of metabolism, using hepatocytes as the basis of liver support. When compared with transplantation of the liver as an organ, the

  12. Hepatocyte heterogeneity in the metabolism of amino acids and ammonia

    NARCIS (Netherlands)

    Häussinger, D.; Lamers, W. H.; Moorman, A. F.

    1992-01-01

    With respect to hepatocyte heterogeneity in ammonia and amino acid metabolism, two different patterns of sublobular gene expression are distinguished: 'gradient-type' and 'strict- or compartment-type' zonation. An example for strict-type zonation is the reciprocal distribution of carbamoylphosphate

  13. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1992-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation. (authors). 8 refs., 4 figs., 5 tabs

  14. Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

    International Nuclear Information System (INIS)

    Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

    1990-01-01

    A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation

  15. Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

    International Nuclear Information System (INIS)

    Ilowski, Maren; Kleespies, Axel; Toni, Enrico N. de; Donabauer, Barbara; Jauch, Karl-Walter; Hengstler, Jan G.; Thasler, Wolfgang E.

    2011-01-01

    Research highlights: → ALR decreases cytochrome c release from mitochondria. → ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. → ALR exerts a liver-specific anti-apoptotic effect. → A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-β, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

  16. Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Ilowski, Maren [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Kleespies, Axel [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Toni, Enrico N. de [Department of Medicine II, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Donabauer, Barbara [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Jauch, Karl-Walter [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Hengstler, Jan G. [Leibniz Research Centre for Working Environment and Human Factors, Technical University, Dortmund (Germany); Thasler, Wolfgang E., E-mail: wolfgang.thasler@med.uni-muenchen.de [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany)

    2011-01-07

    Research highlights: {yields} ALR decreases cytochrome c release from mitochondria. {yields} ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. {yields} ALR exerts a liver-specific anti-apoptotic effect. {yields} A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-{beta}, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

  17. The use of cultured hepatocytes to investigate the metabolism of drugs and mechanisms of drug hepatotoxicity.

    Science.gov (United States)

    Gómez-Lechón, M J; Ponsoda, X; Bort, R; Castell, J V

    2001-01-01

    Hepatotoxins can be classified as intrinsic when they exert their effects on all individuals in a dose-dependent manner, and as idiosyncratic when their effects are the consequence of an abnormal metabolism of the drug by susceptible individuals (metabolic idiosyncrasy) or of an immune-mediated injury to hepatocytes (allergic hepatitis). Some xenobiotics are electrophilic, and others are biotransformed by the liver into highly reactive metabolites that are usually more toxic than the parent compound. This activation process is the key to many hepatotoxic phenomena. Mitochondria are a frequent target of hepatotoxic drugs, and the alteration of their function has immediate effects on the energy balance of cells (depletion of ATP). Lipid peroxidation, oxidative stress, alteration of Ca(2+) homeostasis, and covalent binding to cell macromolecules are the molecular mechanisms that are frequently involved in the toxicity of xenobiotics. Against these potential hazards, cells have their own defence mechanisms (for example, glutathione, DNA repair, suicide inactivation). Ultimately, toxicity is the balance between bioactivation and detoxification, which determines whether a reactive metabolite elicits a toxic effect. The ultimate goal of in vitro experiments is to generate the type of scientific information needed to identify compounds that are potentially toxic to man. For this purpose, both the design of the experiments and the interpretation of the results are critical.

  18. Efavirenz and 8-hydroxyefavirenz induce cell death via a JNK- and BimEL-dependent mechanism in primary human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Bumpus, Namandje N., E-mail: nbumpus1@jhmi.edu

    2011-12-15

    Chronic use of efavirenz (EFV) has been linked to incidences of hepatotoxicity in patients receiving EFV to treat HIV-1. While recent studies have demonstrated that EFV stimulates hepatic cell death a role for the metabolites of efavirenz in this process has yet to be examined. In the present study, incubation of primary human hepatocytes with synthetic 8-hydroxyEFV (8-OHEFV), which is the primary metabolite of EFV, resulted in cell death, caspase-3 activation and reactive oxygen species formation. The metabolite exerted these effects at earlier time points and using lower concentrations than were required for the parent compound. In addition, pharmacological inhibition of cytochrome P450-dependent metabolism of EFV using 1-aminobenzotriazole markedly decreased reactive oxygen species formation and cell death. Treatment of primary human hepatocytes with EFV and 8-OHEFV also stimulated phosphorylation of c-Jun N-terminal kinase (JNK) as well as phosphorylation of the JNK substrate c-Jun. Further, the mRNA and protein expression of an isoform of Bim (Bcl-2 interacting mediator of cell death) denoted as BimEL, which is proapoptotic and has been shown to be modulated by JNK, was increased. Inhibition of JNK using SP600125 prevented the EFV- and 8-OHEFV-mediated cell death. Silencing of Bim using siRNA transfected into hepatocytes also prevented cell death resulting from 8-OHEFV-treatment. These data suggest that the oxidative metabolite 8-OHEFV is a more potent inducer of hepatic cell death than the parent compound EFV. Further, activation of the JNK signaling pathway and BimEL mRNA expression appear to be required for EFV- and 8-OHEFV-mediated hepatocyte death. -- Highlights: Black-Right-Pointing-Pointer 8-Hydroxyefavirenz is a more potent stimulator of cell death than efavirenz. Black-Right-Pointing-Pointer Efavirenz and 8-hydroxyefavirenz increase JNK activity and BimEL mRNA expression. Black-Right-Pointing-Pointer JNK and Bim are required for efavirenz- and 8

  19. Contribution to the qualification of calculation methods of reactivity and of flux and power distributions in nuclear pressurized water reactor cores

    International Nuclear Information System (INIS)

    Abit, K.

    1984-01-01

    The last stage of the creation computer methods and calculations consists of verifying the running and qualifying the results obtained. The work of the present thesis consisted of improving a coupling method between radial and axial phenomena in a PWR core, refering to three-dimensional calculations, while ensuring a perfect coherence between the programmed physical models. The calculation results have been compared to measurements of reactivity and of flux distributions realized during start-up tests. Thus, the methods have been applied to the calculation of the evolution of a burnable poison (gadolinium) in view of operation in long campaign. 13 refs [fr

  20. Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

    International Nuclear Information System (INIS)

    Dever, Joseph T.; Elfarra, Adnan A.

    2009-01-01

    L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 o C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increases in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.

  1. Neutronic characterization of cylindrical core of minor excess reactivity in the nuclear reactor IPEN/MB-01 from the measure of spatial and energetic distribution of neutron flux distribution

    International Nuclear Information System (INIS)

    Aredes, Vitor Ottoni Garcia

    2014-01-01

    In this work was conducted the mapping of the thermal and epithermal neutrons flux and the energy spectrum of the neutrons in the reactor core IPEN/MB-01 for a cylindrical core configuration with minor excess reactivity, which is 28 x 28 fuel rods arranged in north-south and east-west directions. The calibration of control rods for this configuration determined their excess reactivity. The lower excess reactivity in the core decreased neutron flux disturbance caused by the neutron absorbing rods , given that the nuclear reactor was operated with the rods almost completely removed . Was used the 'Activation Analysis Technique' with the thin foil activation detectors ( infinitely diluted and hyper-pure), of different materials that work in different energy ranges, to calculate the saturation activity, used for determining the neutron flux and in the SANDBP code as input for the calculation of the neutrons energy spectrum. To discriminate thermal and epithermal flux , was used the 'Cadmium RatioTechnique' . The activation detectors were distributed in a total of 140 radial and axial positions in the reactor core and 16 irradiation, with bare and covered with cadmium activation foils. A model of this configuration was simulated by MCNP-5 code to determine the cadmium correction factor and comparison of the results obtained experimentally. The cylindrical configuration desired, with 17% less fuel than the standard rectangular configuration (28 x 26 fuel rods), reached criticality with the control rods approximately 90% removed, which decreased considerably the disturbance in neutron flux. Given the highest power density of the 28 x 28 cylindrical core, the neutron flux increased by over 50% in the central regions of the core compared to the values of the 28 x 26 standard rectangular core. (author)

  2. Med1 subunit of the mediator complex in nuclear receptor-regulated energy metabolism, liver regeneration, and hepatocarcinogenesis.

    Science.gov (United States)

    Jia, Yuzhi; Viswakarma, Navin; Reddy, Janardan K

    2014-01-01

    Several nuclear receptors regulate diverse metabolic functions that impact on critical biological processes, such as development, differentiation, cellular regeneration, and neoplastic conversion. In the liver, some members of the nuclear receptor family, such as peroxisome proliferator-activated receptors (PPARs), constitutive androstane receptor (CAR), farnesoid X receptor (FXR), liver X receptor (LXR), pregnane X receptor (PXR), glucocorticoid receptor (GR), and others, regulate energy homeostasis, the formation and excretion of bile acids, and detoxification of xenobiotics. Excess energy burning resulting from increases in fatty acid oxidation systems in liver generates reactive oxygen species, and the resulting oxidative damage influences liver regeneration and liver tumor development. These nuclear receptors are important sensors of exogenous activators as well as receptor-specific endogenous ligands. In this regard, gene knockout mouse models revealed that some lipid-metabolizing enzymes generate PPARα-activating ligands, while others such as ACOX1 (fatty acyl-CoA oxidase1) inactivate these endogenous PPARα activators. In the absence of ACOX1, the unmetabolized ACOX1 substrates cause sustained activation of PPARα, and the resulting increase in energy burning leads to hepatocarcinogenesis. Ligand-activated nuclear receptors recruit the multisubunit Mediator complex for RNA polymerase II-dependent gene transcription. Evidence indicates that the Med1 subunit of the Mediator is essential for PPARα, PPARγ, CAR, and GR signaling in liver. Med1 null hepatocytes fail to respond to PPARα activators in that these cells do not show induction of peroxisome proliferation and increases in fatty acid oxidation enzymes. Med1-deficient hepatocytes show no increase in cell proliferation and do not give rise to liver tumors. Identification of nuclear receptor-specific coactivators and Mediator subunits should further our understanding of the complexities of metabolic

  3. Structure and aqueous reactivity of silicate glasses high-resolution nuclear magnetic resonance contribution; Structure et reactivite aqueuse des verres silicates apport de la resonance magnetique nucleaire haute-resolution

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, F

    2000-10-25

    This research aims at getting a better understanding of the relations which may exist between the chemical composition of the oxide silicate glasses, the structure and the aqueous reactivity. We study the cations present in most glasses, more particularly the radioactive waste glasses, and those which are more liable to bring information both about structure and reactivity. Among the experimental methods used, the nuclear magnetic resonance of multi-quantum magic-angle spinning (NMR MQ-MAS) has been carried out for the structural characterization of the pristine and altered glasses. In the first part, we discuss the possibility of deducting a type of information from a quantitative approach of the {sup 23}Na, {sup 27}Al and {sup 17}O NMR MQ-MAS. In the second part, we apply this method to glasses containing between two and six oxides. The vitreous compositions studied permit to focus our attention on the influence of sodium, aluminum and calcium on their local structural environment. We point out an evolution of the distributions of bond distances and angles in relation to the glass chemical composition. We show the strong potentiality of the {sup 17}O used to probe the pristine and altered glasses. The influence of the different cations studied on the rate of glass dissolution is debated from the alterations made on short periods. On the basis of all these data, we discuss the importance of the structural effect which may influence the kinetic phenomena of alteration. (author)

  4. AMPK Activation Prevents and Reverses Drug-Induced Mitochondrial and Hepatocyte Injury by Promoting Mitochondrial Fusion and Function.

    Directory of Open Access Journals (Sweden)

    Sun Woo Sophie Kang

    Full Text Available Mitochondrial damage is the major factor underlying drug-induced liver disease but whether conditions that thwart mitochondrial injury can prevent or reverse drug-induced liver damage is unclear. A key molecule regulating mitochondria quality control is AMP activated kinase (AMPK. When activated, AMPK causes mitochondria to elongate/fuse and proliferate, with mitochondria now producing more ATP and less reactive oxygen species. Autophagy is also triggered, a process capable of removing damaged/defective mitochondria. To explore whether AMPK activation could potentially prevent or reverse the effects of drug-induced mitochondrial and hepatocellular damage, we added an AMPK activator to collagen sandwich cultures of rat and human hepatocytes exposed to the hepatotoxic drugs, acetaminophen or diclofenac. In the absence of AMPK activation, the drugs caused hepatocytes to lose polarized morphology and have significantly decreased ATP levels and viability. At the subcellular level, mitochondria underwent fragmentation and had decreased membrane potential due to decreased expression of the mitochondrial fusion proteins Mfn1, 2 and/or Opa1. Adding AICAR, a specific AMPK activator, at the time of drug exposure prevented and reversed these effects. The mitochondria became highly fused and ATP production increased, and hepatocytes maintained polarized morphology. In exploring the mechanism responsible for this preventive and reversal effect, we found that AMPK activation prevented drug-mediated decreases in Mfn1, 2 and Opa1. AMPK activation also stimulated autophagy/mitophagy, most significantly in acetaminophen-treated cells. These results suggest that activation of AMPK prevents/reverses drug-induced mitochondrial and hepatocellular damage through regulation of mitochondrial fusion and autophagy, making it a potentially valuable approach for treatment of drug-induced liver injury.

  5. AMPK Activation Prevents and Reverses Drug-Induced Mitochondrial and Hepatocyte Injury by Promoting Mitochondrial Fusion and Function

    Science.gov (United States)

    Taniane, Caitlin; Farrell, Geoffrey; Arias, Irwin M.; Lippincott-Schwartz, Jennifer; Fu, Dong

    2016-01-01

    Mitochondrial damage is the major factor underlying drug-induced liver disease but whether conditions that thwart mitochondrial injury can prevent or reverse drug-induced liver damage is unclear. A key molecule regulating mitochondria quality control is AMP activated kinase (AMPK). When activated, AMPK causes mitochondria to elongate/fuse and proliferate, with mitochondria now producing more ATP and less reactive oxygen species. Autophagy is also triggered, a process capable of removing damaged/defective mitochondria. To explore whether AMPK activation could potentially prevent or reverse the effects of drug-induced mitochondrial and hepatocellular damage, we added an AMPK activator to collagen sandwich cultures of rat and human hepatocytes exposed to the hepatotoxic drugs, acetaminophen or diclofenac. In the absence of AMPK activation, the drugs caused hepatocytes to lose polarized morphology and have significantly decreased ATP levels and viability. At the subcellular level, mitochondria underwent fragmentation and had decreased membrane potential due to decreased expression of the mitochondrial fusion proteins Mfn1, 2 and/or Opa1. Adding AICAR, a specific AMPK activator, at the time of drug exposure prevented and reversed these effects. The mitochondria became highly fused and ATP production increased, and hepatocytes maintained polarized morphology. In exploring the mechanism responsible for this preventive and reversal effect, we found that AMPK activation prevented drug-mediated decreases in Mfn1, 2 and Opa1. AMPK activation also stimulated autophagy/mitophagy, most significantly in acetaminophen-treated cells. These results suggest that activation of AMPK prevents/reverses drug-induced mitochondrial and hepatocellular damage through regulation of mitochondrial fusion and autophagy, making it a potentially valuable approach for treatment of drug-induced liver injury. PMID:27792760

  6. High-Affinity Low-Capacity and Low-Affinity High-Capacity N-Acetyl-2-Aminofluorene (AAF) Macromolecular Binding Sites Are Revealed During the Growth Cycle of Adult Rat Hepatocytes in Primary Culture.

    Science.gov (United States)

    Koch, Katherine S; Moran, Tom; Shier, W Thomas; Leffert, Hyam L

    2018-05-01

    Long-term cultures of primary adult rat hepatocytes were used to study the effects of N-acetyl-2-aminofluorene (AAF) on hepatocyte proliferation during the growth cycle; on the initiation of hepatocyte DNA synthesis in quiescent cultures; and, on hepatocyte DNA replication following the initiation of DNA synthesis. Scatchard analyses were used to identify the pharmacologic properties of radiolabeled AAF metabolite binding to hepatocyte macromolecules. Two classes of growth cycle-dependent AAF metabolite binding sites-a high-affinity low-capacity site (designated Site I) and a low-affinity high-capacity site (designated Site II)-associated with two spatially distinct classes of macromolecular targets, were revealed. Based upon radiolabeled AAF metabolite binding to purified hepatocyte genomic DNA or to DNA, RNA, proteins, and lipids from isolated nuclei, Site IDAY 4 targets (KD[APPARENT] ≈ 2-4×10-6 M and BMAX[APPARENT] ≈ 6 pmol/106 cells/24 h) were consistent with genomic DNA; and with AAF metabolized by a nuclear cytochrome P450. Based upon radiolabeled AAF binding to total cellular lysates, Site IIDAY 4 targets (KD[APPARENT] ≈ 1.5×10-3 M and BMAX[APPARENT] ≈ 350 pmol/106 cells/24 h) were consistent with cytoplasmic proteins; and with AAF metabolized by cytoplasmic cytochrome P450s. DNA synthesis was not inhibited by concentrations of AAF that saturated DNA binding in the neighborhood of the Site I KD. Instead, hepatocyte DNA synthesis inhibition required higher concentrations of AAF approaching the Site II KD. These observations raise the possibility that carcinogenic DNA adducts derived from AAF metabolites form below concentrations of AAF that inhibit replicative and repair DNA synthesis.

  7. Theoretical analysis of nuclear reactors (Phase III), I-V, Part IV, Influence of isotopic composition of nuclear fuel on the reactivity with constant flux; Razrada metoda teorijske analize nuklearnih reaktora (III faza) I-IV, IV Deo, Uticaj promene izotopnog sastava goriva na reaktivnost uz konstantan fluks

    Energy Technology Data Exchange (ETDEWEB)

    Pop-Jordanov, J [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1963-01-15

    Part one of this report presents a series of differential equations describing the nuclear fuel depletion during reactor operation. This series of differential equations is extended to describe the fission products. This part includes equations for effective multiplication factor k{sub eff} and reactivity {rho} as a function of irradiation {tau}. Part two includes results obtained on the analog computer PACE 231 R, and related to Calder Hall type reactor. Part three covers detailed preparation of the series of equations for solution by using the analog computer. Part four includes the list of references related to this task.

  8. The cytoskeleton of digitonin-treated rat hepatocytes.

    Science.gov (United States)

    Fiskum, G; Craig, S W; Decker, G L; Lehninger, A L

    1980-06-01

    Treatment of isolated rat hepatocptes with low concentrations of digitonin increases the permeability of the plsma membrane to cytosolic proteins without causing release of organelles such as mitochondria into the surrounding medium. Electron microscopy showed that treatment of the cells with increasing concentations of digitonin results in a progressive loss in the continuity of the plasma membrane, while most other aspects of cellular morphology remain normal. Depletion of background staining material from the cytosol by digitonin treatment of the cells greatly enhances the visualization of the cytoskeleton. The use of this technique, together with immunofluorescent light microscopy, has verified the presence of an actin-containing filamentous network at the hepatocyte cortex as well as intermediate filaments distributed throughout the cell. Digitonin is thus useful both for selectively permeabilizing the plasma membrane and for intensifying the appearance of intracellular structures such as microfilaments that are normally difficult to observe in cells such as hepatocytes.

  9. Metabolism of six CYP probe substrates in fetal hepatocytes

    Directory of Open Access Journals (Sweden)

    Abdul Naveed Shaik

    2016-06-01

    Full Text Available Cytochrome P-450 (CYP are the most common drug metabolizing enzymes and are abundantly expressed in liver apart from kidney, lungs, intestine, brain etc. Their expression levels change with physiological conditions and disease states. The expression of these CYPs is less in human foetus and neonates compared to adults, which results in lower clearance of xenobiotics in infants and neonates compared to adults. Hepatocytes are the cells which are largely used to study these CYPs. We have isolated hepatocytes from aborted foetus to study the metabolism of six probe substrates: phenacetin, diclofenac, S-mephenytoin, dextromethorphan, nifedipine and testosterone. The results obtained show the expression of various CYPs (CYP1A2, CYP2C19, CYP2C9, CYP2D6, and CYP3A4 in human foetus and their involvement in metabolism of CYP probe substrates.

  10. [Current status and future perspectives of hepatocyte transplantation].

    Science.gov (United States)

    Pareja, Eugenia; Cortés, Miriam; Gómez-Lechón, M José; Maupoey, Javier; San Juan, Fernando; López, Rafael; Mir, Jose

    2014-02-01

    The imbalance between the number of potential beneficiaries and available organs, originates the search for new therapeutic alternatives, such as Hepatocyte transplantation (HT).Even though this is a treatment option for these patients, the lack of unanimity of criteria regarding indications and technique, different cryopreservation protocols, as well as the different methodology to assess the response to this therapy, highlights the need of a Consensus Conference to standardize criteria and consider future strategies to improve the technique and optimize the results.Our aim is to review and update the current state of hepatocyte transplantation, emphasizing the future research attempting to solve the problems and improve the results of this treatment. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

  11. The reactivity meter and core reactivity

    International Nuclear Information System (INIS)

    Siltanen, P.

    1999-01-01

    This paper discussed in depth the point kinetic equations and the characteristics of the point kinetic reactivity meter, particularly for large negative reactivities. From a given input signal representing the neutron flux seen by a detector, the meter computes a value of reactivity in dollars (ρ/β), based on inverse point kinetics. The prompt jump point of view is emphasised. (Author)

  12. Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee [College of Veterinary Medicine, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Jeong, Jieun; Wi, Anjin; Park, Whoashig [Jeollanamdo Forest Resources Research Institute, Naju 520-833 (Korea, Republic of); Han, Ho-jae [College of Veterinary Medicine, Seoul National University, Seoul 151-741 (Korea, Republic of); Park, Soo-hyun, E-mail: parksh@chonnam.ac.kr [College of Veterinary Medicine, Chonnam National University, Gwangju 500-757 (Korea, Republic of)

    2015-06-05

    Previously, we reported that CARM1 undergoes ubiquitination-dependent degradation in renal podocytes. It was also reported that CARM1 is necessary for fasting-induced hepatic gluconeogenesis. Based on these reports, we hypothesized that treatment with insulin, a hormone typically present under the ‘fed’ condition, would inhibit gluconeogenesis via CARM1 degradation. HepG2 cells, AML-12 cells, and rat primary hepatocytes were treated with insulin to confirm CARM1 downregulation. Surprisingly, insulin treatment increased CARM1 expression in all cell types examined. Furthermore, treatment with insulin increased histone 3 methylation at arginine 17 and 26 in HepG2 cells. To elucidate the role of insulin-induced CARM1 upregulation, the HA-CARM1 plasmid was transfected into HepG2 cells. CARM1 overexpression did not increase the expression of lipogenic proteins generally increased by insulin signaling. Moreover, CARM1 knockdown did not influence insulin sensitivity. Insulin is known to facilitate hepatic proliferation. Like insulin, CARM1 overexpression increased CDK2 and CDK4 expression. In addition, CARM1 knockdown reduced the number of insulin-induced G2/M phase cells. Moreover, GFP-CARM1 overexpression increased the number of G2/M phase cells. Based on these results, we concluded that insulin-induced CARM1 upregulation facilitates hepatocyte proliferation. These observations indicate that CARM1 plays an important role in liver pathophysiology. - Highlights: • Insulin treatment increases CARM1 expression in hepatocytes. • CARM1 overexpression does not increase the expression of lipogenic proteins. • CARM1 knockdown does not influence insulin sensitivity. • Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation.

  13. Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

    International Nuclear Information System (INIS)

    Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee; Jeong, Jieun; Wi, Anjin; Park, Whoashig; Han, Ho-jae; Park, Soo-hyun

    2015-01-01

    Previously, we reported that CARM1 undergoes ubiquitination-dependent degradation in renal podocytes. It was also reported that CARM1 is necessary for fasting-induced hepatic gluconeogenesis. Based on these reports, we hypothesized that treatment with insulin, a hormone typically present under the ‘fed’ condition, would inhibit gluconeogenesis via CARM1 degradation. HepG2 cells, AML-12 cells, and rat primary hepatocytes were treated with insulin to confirm CARM1 downregulation. Surprisingly, insulin treatment increased CARM1 expression in all cell types examined. Furthermore, treatment with insulin increased histone 3 methylation at arginine 17 and 26 in HepG2 cells. To elucidate the role of insulin-induced CARM1 upregulation, the HA-CARM1 plasmid was transfected into HepG2 cells. CARM1 overexpression did not increase the expression of lipogenic proteins generally increased by insulin signaling. Moreover, CARM1 knockdown did not influence insulin sensitivity. Insulin is known to facilitate hepatic proliferation. Like insulin, CARM1 overexpression increased CDK2 and CDK4 expression. In addition, CARM1 knockdown reduced the number of insulin-induced G2/M phase cells. Moreover, GFP-CARM1 overexpression increased the number of G2/M phase cells. Based on these results, we concluded that insulin-induced CARM1 upregulation facilitates hepatocyte proliferation. These observations indicate that CARM1 plays an important role in liver pathophysiology. - Highlights: • Insulin treatment increases CARM1 expression in hepatocytes. • CARM1 overexpression does not increase the expression of lipogenic proteins. • CARM1 knockdown does not influence insulin sensitivity. • Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

  14. [Crabtree effect caused by ketoses in isolated rat hepatocytes].

    Science.gov (United States)

    Martínez, P; Carrascosa, J M; Núñez de Castro, I

    1982-01-01

    Oxygen uptake and glycolytic activity were studied in hepatocytes isolated from fed rats. The addition of fructose or tagatose resulted in a 38% and 31% inhibition of cellular respiration respectively. The addition of 10 mM D-glyceraldehyde caused a slight Crabtree effect. Glucose, L-sorbose, or glycerol failed to modify oxygen consumption. Only incubation in the presence of fructose showed a high aerobic glycolysis measured by lactate production.

  15. Hepatocyte polyploidization and its association with pathophysiological processes

    OpenAIRE

    Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

    2017-01-01

    A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as ...

  16. Functional activity of the rats’ hepatocytes under cancerogenesis

    Directory of Open Access Journals (Sweden)

    V. V. Ivchuk

    2007-10-01

    Full Text Available Enzymatic activity in rat’s hepatocytes under carcinoma Geuren T8 development as well as after introduction of rhenium compounds and cis-platin were studied. It has been determined that the decrease of enzymatic activity contrary to the control animals has been observed under simultaneous injection of cis-platin and cluster rhenium compounds in a liposome form. That confirms possible hepatoprotective properties of the rhenium compounds.

  17. Cholangiocarcinoma in Cirrhosis: Value of Hepatocyte Specific Magnetic Resonance Imaging.

    Science.gov (United States)

    Piscaglia, Fabio; Iavarone, Massimo; Galassi, Marzia; Vavassori, Sara; Renzulli, Matteo; Forzenigo, Laura Virginia; Granito, Alessandro; Salvatore, Veronica; Sangiovanni, Angelo; Golfieri, Rita; Colombo, Massimo; Bolondi, Luigi

    2015-10-01

    The diagnosis of intrahepatic cholangiocellular carcinoma (ICC) remains elusive at imaging, which is a critical issue in cirrhotic patients in whom a diagnosis of hepatocellular carcinoma (HCC) can be established only by imaging. The aim of the study was to evaluate the potential of MRI in the diagnosis of ICC in cirrhosis using 'hepatocyte-specific' Gadolinium (Gd)-based contrast agents. Sixteen histologically proven and retrospectively identified ICCs on cirrhosis were investigated with hepatocyte-specific magnetic resonance contrast agents (6 in Bologna with Gd-EOB-DTPA and 10 in Milan with Gd-BOPTA). The control group consisted of 41 consecutively and prospectively collected nodules (31 HCCs) imaged with Gd-EOB-DTPA. Fifteen ICC nodules (94%) displayed hypointensity in the hepatobiliary phase, suggesting malignancy. Thirteen cholangiocarcinomas (81%) showed hyperenhancement in the venous phase. Only 2 cholangiocarcinoma nodules showed hypoenhancement in the venous phase, corresponding to washout, in both cases preceded by rim enhancement in arterial phase. All the hepatocarcinomas showed hypointensity in hepatobiliary phase, but was always preceded by hypointensity in the venous phase; arterial rim enhancement was never observed in any hepatocarcinoma or regenerative nodule. MRI with hepatocyte-specific Gd-based contrast agents showed a pattern of malignancy in almost all the ICCs, concurrently avoiding misdiagnosis with hepatocarcinoma. These findings suggest a greater diagnostic capacity for this technique compared with the results of MRI with conventional contrast agents reported in the literature in this setting. © 2015 S. Karger AG, Basel.

  18. A fast and robust hepatocyte quantification algorithm including vein processing

    Directory of Open Access Journals (Sweden)

    Homeyer André

    2010-03-01

    Full Text Available Abstract Background Quantification of different types of cells is often needed for analysis of histological images. In our project, we compute the relative number of proliferating hepatocytes for the evaluation of the regeneration process after partial hepatectomy in normal rat livers. Results Our presented automatic approach for hepatocyte (HC quantification is suitable for the analysis of an entire digitized histological section given in form of a series of images. It is the main part of an automatic hepatocyte quantification tool that allows for the computation of the ratio between the number of proliferating HC-nuclei and the total number of all HC-nuclei for a series of images in one processing run. The processing pipeline allows us to obtain desired and valuable results for a wide range of images with different properties without additional parameter adjustment. Comparing the obtained segmentation results with a manually retrieved segmentation mask which is considered to be the ground truth, we achieve results with sensitivity above 90% and false positive fraction below 15%. Conclusions The proposed automatic procedure gives results with high sensitivity and low false positive fraction and can be applied to process entire stained sections.

  19. Adropin induction of lipoprotein lipase expression in tilapia hepatocytes.

    Science.gov (United States)

    Lian, Anji; Wu, Keqiang; Liu, Tianqiang; Jiang, Nan; Jiang, Quan

    2016-01-01

    The peptide hormone adropin plays a role in energy homeostasis. However, biological actions of adropin in non-mammalian species are still lacking. Using tilapia as a model, we examined the role of adropin in lipoprotein lipase (LPL) regulation in hepatocytes. To this end, the structural identity of tilapia adropin was established by 5'/3'-rapid amplification of cDNA ends (RACE). The transcripts of tilapia adropin were ubiquitously expressed in various tissues with the highest levels in the liver and hypothalamus. The prolonged fasting could elevate tilapia hepatic adropin gene expression, whereas no effect of fasting was observed on hypothalamic adropin gene levels. In primary cultures of tilapia hepatocytes, synthetic adropin was effective in stimulating LPL release, cellular LPL content, and total LPL production. The increase in LPL production also occurred with parallel rises in LPL gene levels. In parallel experiments, adropin could elevate cAMP production and up-regulate protein kinase A (PKA) and PKC activities. Using a pharmacological approach, cAMP/PKA and PLC/inositol trisphosphate (IP3)/PKC cascades were shown to be involved in adropin-stimulated LPL gene expression. Parallel inhibition of p38MAPK and Erk1/2, however, were not effective in these regards. Our findings provide, for the first time, evidence that adropin could stimulate LPL gene expression via direct actions in tilapia hepatocytes through the activation of multiple signaling mechanisms. © 2016 Society for Endocrinology.

  20. Homocysteine inhibits hepatocyte proliferation via endoplasmic reticulum stress.

    Directory of Open Access Journals (Sweden)

    Xue Yu

    Full Text Available Homocysteine is an independent risk factor for coronary, cerebral, and peripheral vascular diseases. Recent studies have shown that levels of homocysteine are elevated in patients with impaired hepatic function, but the precise role of homocysteine in the development of hepatic dysfunction is unclear. In this study, we examined the effect of homocysteine on hepatocyte proliferation in vitro. Our results demonstrated that homocysteine inhibited hepatocyte proliferation by up-regulating protein levels of p53 as well as mRNA and protein levels of p21(Cip1 in primary cultured hepatocytes. Homocysteine induced cell growth arrest in p53-positive hepatocarcinoma cell line HepG2, but not in p53-null hepatocarcinoma cell line Hep3B. A p53 inhibitor pifithrin-α inhibited the expression of p21(Cip1 and attenuated homocysteine-induced cell growth arrest. Homocysteine induced TRB3 expression via endoplasmic reticulum stress pathway, resulting in Akt dephosphorylation. Knock-down of endogenous TRB3 significantly suppressed the inhibitory effect of homocysteine on cell proliferation and the phosphorylation of Akt. LiCl reversed homocysteine-mediated cell growth arrest by inhibiting TRB3-mediated Akt dephosphorylation. These results demonstrate that both TRB3 and p21(Cip1 are critical molecules in the homocysteine signaling cascade and provide a mechanistic explanation for impairment of liver regeneration in hyperhomocysteinemia.

  1. Sea sand for reactive barriers

    International Nuclear Information System (INIS)

    Garcia R, G.; Ordonez R, E.; Ordonez R, En.

    2002-01-01

    Some phosphates have the property to suck in radioactive metals in solution, what it is taken in advance to make reactive barriers which are placed in the nuclear waste repositories. In an effort for contributing to the study of this type of materials, it has been obtained the zirconium silicate (ZrSiO 4 ) and the alpha zirconium hydrogen phosphate (Zr(HPO 4 ) 2H 2 O) starting from sea sand in an easy and economic way. (Author)

  2. Basal transcription of APOBEC3G is regulated by USF1 gene in hepatocyte

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yanli [Department of Infectious Diseases, Zhengzhou University People' s Hospital (Henan Provincial People' s Hospital), Zhengzhou, 450003 (China); Li, Hui [The Central Hospital of Wuhan, Tongji Medical College Huazhong University of Science Technology, Wuhan, 430000 (China); Zhang, Xiaoju [Department of Respiratory Medicine, Zhengzhou University People' s Hospital (Henan Provincial People' s Hospital), Zhengzhou, 450003 (China); Shang, Jia [Department of Infectious Diseases, Zhengzhou University People' s Hospital (Henan Provincial People' s Hospital), Zhengzhou, 450003 (China); Kang, Yi, E-mail: kykangyi@163.com [Department of Infectious Diseases, Zhengzhou University People' s Hospital (Henan Provincial People' s Hospital), Zhengzhou, 450003 (China)

    2016-01-29

    Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G, A3G) exert antiviral defense as an important factor of innate immunity. A variety of cytokines such as IFN-γ,IL2,IL15,IL7 could induce the transcription of A3G. However, the regulation of other nuclear factor on the transcription of A3G have not been reported at the present. To gain new insights into the transcriptional regulation of this restriction factor, we cloned and characterized the promoter region of A3G and investigate the modulation of USF1 gene on the transcription of A3G. We identified a 232 bp region that was sufficient to regulate the activity of full promoter. Transcriptional start sites (TSS) were identified by the luciferase reporter assays of plasmids containing full or shorter fragments of the A3G promoter. The results demonstrated that the core promoter of A3G is located within the region -159/-84 relative to the TSS. Transcriptional activity of A3G core promoter regulated by USF1 was dependent on an E-box (located at position -91/-86 relative to the major TSS) and was abolished after mutation of this DNA element. USF1 gene can take part in basal transcription regulation of the human A3G gene in hepatocyte, and the identified E-box represented a binding site for the USF1. - Highlights: • The core promoter of A3G is located within the region −159/−84 relative to the TSS. • Transcriptional activity of A3G core promoter regulated by USF1 was dependent on an E-box (located at position −91/−86 relative to the major TSS). • USF1 gene can take part in basal transcription regulation of the human A3G gene in hepatocyte.

  3. Basal transcription of APOBEC3G is regulated by USF1 gene in hepatocyte

    International Nuclear Information System (INIS)

    Zeng, Yanli; Li, Hui; Zhang, Xiaoju; Shang, Jia; Kang, Yi

    2016-01-01

    Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G, A3G) exert antiviral defense as an important factor of innate immunity. A variety of cytokines such as IFN-γ,IL2,IL15,IL7 could induce the transcription of A3G. However, the regulation of other nuclear factor on the transcription of A3G have not been reported at the present. To gain new insights into the transcriptional regulation of this restriction factor, we cloned and characterized the promoter region of A3G and investigate the modulation of USF1 gene on the transcription of A3G. We identified a 232 bp region that was sufficient to regulate the activity of full promoter. Transcriptional start sites (TSS) were identified by the luciferase reporter assays of plasmids containing full or shorter fragments of the A3G promoter. The results demonstrated that the core promoter of A3G is located within the region -159/-84 relative to the TSS. Transcriptional activity of A3G core promoter regulated by USF1 was dependent on an E-box (located at position -91/-86 relative to the major TSS) and was abolished after mutation of this DNA element. USF1 gene can take part in basal transcription regulation of the human A3G gene in hepatocyte, and the identified E-box represented a binding site for the USF1. - Highlights: • The core promoter of A3G is located within the region −159/−84 relative to the TSS. • Transcriptional activity of A3G core promoter regulated by USF1 was dependent on an E-box (located at position −91/−86 relative to the major TSS). • USF1 gene can take part in basal transcription regulation of the human A3G gene in hepatocyte.

  4. Differential Impacts of Soybean and Fish Oils on Hepatocyte Lipid Droplet Accumulation and Endoplasmic Reticulum Stress in Primary Rabbit Hepatocytes

    OpenAIRE

    Zhu, Xueping; Xiao, Zhihui; Xu, Yumin; Zhao, Xingli; Cheng, Ping; Cui, Ningxun; Cui, Mingling; Li, Jie; Zhu, Xiaoli

    2016-01-01

    Parenteral nutrition-associated liver disease (PNALD) is a severe ailment associated with long-term parenteral nutrition. Soybean oil-based lipid emulsions (SOLE) are thought to promote PNALD development, whereas fish oil-based lipid emulsions (FOLE) are thought to protect against PNALD. This study aimed to investigate the effects of SOLE and FOLE on primary rabbit hepatocytes. The results reveal that SOLE caused significant endoplasmic reticulum (ER) and mitochondrial damage, ultimately resu...

  5. Differential Impacts of Soybean and Fish Oils on Hepatocyte Lipid Droplet Accumulation and Endoplasmic Reticulum Stress in Primary Rabbit Hepatocytes

    Directory of Open Access Journals (Sweden)

    Xueping Zhu

    2016-01-01

    Full Text Available Parenteral nutrition-associated liver disease (PNALD is a severe ailment associated with long-term parenteral nutrition. Soybean oil-based lipid emulsions (SOLE are thought to promote PNALD development, whereas fish oil-based lipid emulsions (FOLE are thought to protect against PNALD. This study aimed to investigate the effects of SOLE and FOLE on primary rabbit hepatocytes. The results reveal that SOLE caused significant endoplasmic reticulum (ER and mitochondrial damage, ultimately resulting in lipid droplets accumulation and ER stress. While these deleterious events induce hepatocyte injury, FOLE at high doses cause only minor ER and mitochondrial damage, which has no effect on hepatic function. SOLE also significantly upregulated glucose-regulated protein 94 mRNA and protein expression. These data indicate that SOLE, but not FOLE, damage the ER and mitochondria, resulting in lipid droplets accumulation and ER stress and, finally, hepatocyte injury. This likely contributes to the differential impacts of SOLE and FOLE on PNALD development and progression.

  6. Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema

    Directory of Open Access Journals (Sweden)

    Marchal Joëlle

    2005-10-01

    Full Text Available Abstract Background Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. Methods Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. Results Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. Conclusion The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers.

  7. DNA synthesis in periportal and perivenous hepatocytes of intact and hepatectomized young mice.

    Science.gov (United States)

    Fernández-Blanco, A; Inda, A M; Errecalde, A L

    2015-01-01

    DNA synthesis of hepatocytes in two areas of Intact and Hepatectomized young mice liver along a circadian period was studied. DNA synthesis was significantly different at all analyzed time points in Intact and Hepatectomized animals. Differences between periportal and perivenous hepatocytes were found in hepatectomized animals at 04/42 and 08/46 hr of day/hour post-hepatectomy. DNAs peak in periportal hepatocytes regenerating liver occurs 4 hr earlier than in perivenous hepatocytes, probably reflecting their shorter G1 phase. Besides, daily mean values of regenerating livers were higher than those observed in Intact animals, as a consequence of surgical removal.

  8. Lack of direct mitogenic activity of dichloroacetate and trichloroacetate in cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Walgren, Jennie L.; Kurtz, David T.; McMillan, JoEllyn M.

    2005-01-01

    Dichloroacetate (DCA) and trichloroacetate (TCA) are hepatocarcinogenic metabolites of the common groundwater contaminant, 1,1,2-trichloroethylene. DCA and TCA have been shown to induce hepatocyte proliferation in vivo, but it is not known if this response is the result of direct mitogenic activity or whether cell replication occurs indirectly in response to tissue injury or inflammation. In this study we used primary cultures of rat hepatocytes, a species susceptible to DCA- but not TCA-induced hepatocarcinogenesis, to determine whether DCA and TCA are direct hepatocyte mitogens. Rat hepatocytes, cultured in growth factor-free medium, were treated with 0.01-1.0 mM DCA or TCA for 10-40 h; cell replication was then assessed by measuring incorporation of 3 H-thymidine into DNA and by cell counts. DCA or TCA treatment did not alter 3 H-thymidine incorporation in the cultured hepatocytes. Although an increase in cell number was not observed, DCA treatment significantly abrogated the normal background cell loss, suggesting an ability to inhibit apoptotic cell death in primary hepatocyte cultures. Furthermore, treatment with DCA synergistically enhanced the mitogenic response to epidermal growth factor. The data indicate that DCA and TCA are not direct mitogens in hepatocyte cultures, which is of interest in view of their ability to stimulate hepatocyte replication in vivo. Nevertheless, the synergistic enhancement of epidermal growth factor-induced hepatocyte replication by DCA is of particular interest and warrants further study

  9. Gel entrapment culture of rat hepatocytes for investigation of tetracycline-induced toxicity

    International Nuclear Information System (INIS)

    Shen Chong; Meng Qin; Schmelzer, Eva; Bader, Augustinus

    2009-01-01

    This paper aimed to explore three-dimensionally cultured hepatocytes for testing drug-induced nonalcoholic steatohepatitis. Gel entrapped rat hepatocytes were applied for investigation of the tetracycline-induced steatohepatitis, while hepatocyte monolayer was set as a control. The toxic responses of hepatocytes were systematically evaluated by measuring cell viability, liver-specific function, lipid accumulation, oxidative stress, adenosine triphosphate content and mitochondrial membrane potential. The results suggested that gel entrapped hepatocytes showed cell death after 96 h of tetracycline treatment at 25 μM which is equivalent to toxic serum concentration in rats, while hepatocyte monolayer showed cell death at a high dose of 200 μM. The concentration-dependent accumulation of lipid as well as mitochondrial damage were regarded as two early events for tetracycline hepatotoxicity in gel entrapment culture due to their detectability ahead of subsequent increase of oxidative stress and a final cell death. Furthermore, the potent protection of fenofibrate and fructose-1,6-diphosphate were evidenced in only gel entrapment culture with higher expressions on the genes related to β-oxidation than hepatocyte monolayer, suggesting the mediation of lipid metabolism and mitochondrial damage in tetracycline toxicity. Overall, gel entrapped hepatocytes in three-dimension reflected more of the tetracycline toxicity in vivo than hepatocyte monolayer and thus was suggested as a more relevant system for evaluating steatogenic drugs.

  10. A sensitivity analysis and assessment on the reactivity, economics and resorce implications of reactor systems and cycles with respect to uncertainity in nuclear data and other reactor parameters

    International Nuclear Information System (INIS)

    Quan, B.L.

    1980-01-01

    A general sensitivity analysis system for analyzing the effects of uncertainity in nuclear data and reactor parameters on fuel cycle economics, resources and physics has been developed. The sensitivity analysis has been performed on various reactor systems and cycles such as the thorium cycles, plutonium cycles, CANDU reactor fuel cycles and alternate once-through LWR cycles such as the 18 month cycle. Sensitivity coefficients were generated for a variety of materials pertinent to the LWR fuel cycle using a series of fast running codes developed for this purpose and running on a local PDP-15 computer. Their relative order of importance were assessed and the reasons explaining this difference were examined. This work is a result of EPRI project in determining the data needs for the LWR industry and should be valuable in identifying areas in which data improvements are worthwhile

  11. Nuclear criticality safety: general. 5. Reactivity Effect of Burnable Absorbers in Burnup Credit for the CASTOR X/32S Storage and Transport Cask

    International Nuclear Information System (INIS)

    Rombough, Charles T.; Lancaster, Dale B.; Diersch, Rudolf; Spilker, Harry

    2001-01-01

    When considering burnup credit in the licensing of storage and transportation casks, a significant effect is whether or not the burned fuel was depleted with burnable absorbers present. This paper presents the results of detailed calculations to quantitatively determine the burnable absorber effect for the CASTOR X/32S transport cask, which assumes burnup of the fuel in the criticality analysis. A radial view of the CASTOR X/32S cask is shown in Fig. 1. This is the actual plot of the geometry as modeled in KENO V.a. Note that there are no water-filled flux traps and the assemblies are tightly packed. This reduces the overall dimensions of the cask for a given number of fuel assemblies. Reactivity is held down by borated aluminum plates between the fuel assemblies and by placing absorber rod modules (ARMs) in the guide tubes of selected assemblies. If burnup of the fuel is not considered and the initial enrichment is 5.0 wt% 235 U, then 28 of the 32 fuel assemblies must contain an ARM to maintain a k eff 3 ; 4. moderator temperature of 604 K; 5. cooling time of 9.5 yr; 6. specific power of 60 W/g of U metal; 7. conservative axial and radial burnup shape distribution; 8. Westinghouse BP material containing 12.5 wt% B 4 C. Using the model described earlier, calculations were performed with varying numbers of BP fingers inserted for different exposure times. The results are shown in Tables I and II. The 1 s statistical error in these results is σ equals ±0.05%. Note that the BP finger and exposure effects decrease with fuel burnup and the effect is smaller when the cask contains ARMs. Conservatively combining the results from Tables I and II and interpolating, we can equate fewer BP fingers with longer BP exposure time as shown in Table III. The Table III results were checked by running the actual cases (for example, 20 BP fingers for 24 GWd/tonne exposure) to verify that the k eff 's for the cask were always less than the base-case values. These results can also be

  12. Magnetic cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of hepatocyte transplantation.

    Directory of Open Access Journals (Sweden)

    Dwayne R Roach

    Full Text Available Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this work, we describe culture conditions for magnetic cell labeling of cells from two different pig hepatocyte cell sources; primary pig hepatocytes (ppHEP and stem cell-derived hepatocytes (PICM-19FF. The magnetic particle is a micron-sized iron oxide particle (MPIO that has been extensively studied for magnetic cell labeling for MRI-based cell tracking. ppHEP could endocytose MPIO with labeling percentages as high as 70%, achieving iron content as high as ~55 pg/cell, with >75% viability. PICM-19FF had labeling >97%, achieving iron content ~38 pg/cell, with viability >99%. Extensive morphological and functional assays indicated that magnetic cell labeling was benign to the cells. The results encourage the use of MRI-based cell tracking for the development and clinical use of hepatocyte transplantation methodologies. Further, these results generally highlight the importance of functional cell assays in the evaluation of contrast agent biocompatibility.

  13. Leflunomide or A77 1726 protect from acetaminophen-induced cell injury through inhibition of JNK-mediated mitochondrial permeability transition in immortalized human hepatocytes

    International Nuclear Information System (INIS)

    Latchoumycandane, Calivarathan; Seah, Quee Ming; Tan, Rachel C.H.; Sattabongkot, Jetsumon; Beerheide, Walter; Boelsterli, Urs A.

    2006-01-01

    Leflunomide, a disease-modifying anti-rheumatic drug, protects against T-cell-mediated liver injury by poorly understood mechanisms. The active metabolite of leflunomide, A77 1726 (teriflunomide) has been shown to inhibit stress-activated protein kinases (JNK pathway), which are key regulators of mitochondria-mediated cell death. Therefore, we hypothesized that leflunomide may protect from drugs that induce the mitochondrial permeability transition (mPT) by blocking the JNK signaling pathway. To this end, we exposed cultured immortalized human hepatocytes (HC-04) to the standard protoxicant drug acetaminophen (APAP), which induces CsA-sensitive mPT-mediated cell death. We determined the effects of leflunomide on the extent of APAP-induced hepatocyte injury and the upstream JNK-mediated mitochondrial signaling pathways. We found that leflunomide or A77 1726 concentration-dependently protected hepatocytes from APAP (1 mM)-induced mitochondrial permeabilization and lethal cell injury. This was not due to proximal inhibition of CYP-catalyzed APAP bioactivation to its thiol-reactive metabolite. Instead, we demonstrate that leflunomide (20 μM) inhibited the APAP-induced early (3 h) activation (phosphorylation) of JNK1/2, thus inhibiting phosphorylation of the anti-apoptotic protein Bcl-2 and preventing P-Bcl-2-mediated induction of the mPT. This greatly attenuated mitochondrial cytochrome c release, which we used as a marker for mitochondrial permeabilization. The specific JNK2 inhibitor SP600125 similarly protected from APAP-induced cell death. In conclusion, these findings are consistent with our hypothesis that leflunomide protects from protoxicant-induced hepatocyte injury by inhibiting JNK signaling and preventing mPT induction

  14. Hepatocyte spheroids as a competent in vitro system for drug biotransformation studies: nevirapine as a bioactivation case study.

    Science.gov (United States)

    Pinheiro, Pedro F; Pereira, Sofia A; Harjivan, Shrika G; Martins, Inês L; Marinho, Aline T; Cipriano, Madalena; Jacob, Cristina C; Oliveira, Nuno G; Castro, Matilde F; Marques, M Matilde; Antunes, Alexandra M M; Miranda, Joana P

    2017-03-01

    The development of metabolically competent in vitro models is of utmost importance for predicting adverse drug reactions, thereby preventing attrition-related economical and clinical burdens. Using the antiretroviral drug nevirapine (NVP) as a model, this work aimed to validate rat hepatocyte 3D spheroid cultures as competent in vitro systems to assess drug metabolism and bioactivation. Hepatocyte spheroids were cultured for 12 days in a stirred tank system (3D cultures) and exposed to equimolar dosages of NVP and its two major Phase I metabolites, 12-OH-NVP and 2-OH-NVP. Phase I NVP metabolites were detected in the 3D cultures during the whole culture time in the same relative proportions reported in in vivo studies. Moreover, the modulation of SULT1A1 activity by NVP and 2-OH-NVP was observed for the first time, pointing their synergistic effect as a key factor in the formation of the toxic metabolite (12-sulfoxy-NVP). Covalent adducts formed by reactive NVP metabolites with N-acetyl-L-cysteine and bovine serum albumin were also detected by high-resolution mass spectrometry, providing new evidence on the relative role of the reactive NVP metabolites, 12-sulfoxy-NVP, and NVP quinone methide, in toxicity versus excretion pathways. In conclusion, these results demonstrate the validity of the 3D culture system to evaluate drug bioactivation, enabling the identification of potential biomarkers of bioactivation/toxicity, and providing new evidence to the mechanisms underlying NVP-induced toxic events. This model, integrated with the analytical strategies described herein, is of anticipated usefulness to the pharmaceutical industry, as an upstream methodology for flagging drug safety alerts in early stages of drug development.

  15. Study of the antioxidant effects of Eremostachys laciniata rhizome extracts in isolated rat hepatocytes

    Directory of Open Access Journals (Sweden)

    Haleh Vaez

    2015-09-01

    Full Text Available Eremostachys laciniata, having rich flavonoid content, is expected to have a considerable antioxidant effect. In this study We used ACMS (Accelerated cytotoxic or protective mechanism screening technique to evaluate the possible antioxidant effect of E. laciniata rhizome against oxidative cell damages induced by different types of oxidative stress such as iron-8-hydroxyquinolin (IQ complex and copper in freshly isolated liver cells. The extracts were prepared with n-hexane, dichloromethane and methanol. Hepatocytes were isolated from male Sprague-Dawley rats by a two-step collagenase perfusion. Cell viability was measured by trypan blue exclusion method. DPPH (2, 2-diphenyl-1-picrylhydrazyl assay was used to evaluate the antioxidant activity. ROS formation was measured by using DCFDA (2, 7-dichlorofluorescin diacetate probe, mitochondrial membrane potential (MMP was assessed by rhodamine 123 fluorescence and lipid peroxidation was determined by thiobarbituric acid reactive substances (TBARS assay. The MET extract was demonstrated to possess a significant radical scavenging activity (RC50%=0.212. Unlike MET extract, the n-hexane and dichloromethane extracts showed toxic effects in cell suspensions. The MET extract significantly decreased cell death and ROS formation induced by IQ complex and copper and demonstrated protective effects against copper-induced mitochondrial membrane potential collapse and lipid peroxidation. The protection induced by MET extract can be attributed to antioxidant characteristics of the phenylethanoids content.

  16. The partial pressure of oxygen affects biomarkers of oxidative stress in cultured rainbow trout (Oncorhynchus mykiss) hepatocytes.

    Science.gov (United States)

    Finne, E F; Olsvik, P A; Berntssen, M H G; Hylland, K; Tollefsen, K E

    2008-09-01

    Oxidative stress, the imbalance between production of reactive oxygen species and the cellular detoxification of these reactive compounds, is believed to be involved in the pathology of various diseases. Several biomarkers for oxidative stress have been proposed to serve as tools in toxicological and ecotoxicological research. Not only may exposure to various pro-oxidants create conditions of cellular oxidative stress, but hyperoxic conditions may also increase the production of reactive oxygen species. The objective of the current study was to determine the extent to which differences in oxygen partial pressure would affect biomarkers of oxidative stress in a primary culture of hepatocytes from rainbow trout (Oncorhynchus mykiss). Membrane integrity, metabolic activity, levels of total and oxidized glutathione (tGSH/GSSG) was determined, as well as mRNA expression levels of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), gamma-glutamyl-cystein synthetase (GCS) and thioredoxin (TRX). The results show that different biomarkers of oxidative stress are affected when the cell culture is exposed to atmospheric oxygen, and that changes such as increased GSSG content and induction of GSSG-R and GSH-Px can be reduced by culturing the cells under lower oxygen tension. Oxygen tension may thus influence results of in vitro based cell research and is particularly important when assessing parameters in the antioxidant defence system. Further research is needed to establish the magnitude of this effect in different cellular systems.

  17. Coactivator PGC-1α regulates the fasting inducible xenobiotic-metabolizing enzyme CYP2A5 in mouse primary hepatocytes

    International Nuclear Information System (INIS)

    Arpiainen, Satu; Jaervenpaeae, Sanna-Mari; Manninen, Aki; Viitala, Pirkko; Lang, Matti A.; Pelkonen, Olavi; Hakkola, Jukka

    2008-01-01

    The nutritional state of organisms and energy balance related diseases such as diabetes regulate the metabolism of xenobiotics such as drugs, toxins and carcinogens. However, the mechanisms behind this regulation are mostly unknown. The xenobiotic-metabolizing cytochrome P450 (CYP) 2A5 enzyme has been shown to be induced by fasting and by glucagon and cyclic AMP (cAMP), which mediate numerous fasting responses. Peroxisome proliferator-activated receptor γ coactivator (PGC)-1α triggers many of the important hepatic fasting effects in response to elevated cAMP levels. In the present study, we were able to show that cAMP causes a coordinated induction of PGC-1α and CYP2A5 mRNAs in murine primary hepatocytes. Furthermore, the elevation of the PGC-1α expression level by adenovirus mediated gene transfer increased CYP2A5 transcription. Co-transfection of Cyp2a5 5' promoter constructs with the PGC-1α expression vector demonstrated that PGC-1α is able to activate Cyp2a5 transcription through the hepatocyte nuclear factor (HNF)-4α response element in the proximal promoter of the Cyp2a5 gene. Chromatin immunoprecipitation assays showed that PGC-1α binds, together with HNF-4α, to the same region at the Cyp2a5 proximal promoter. In conclusion, PGC-1α mediates the expression of CYP2A5 induced by cAMP in mouse hepatocytes through coactivation of transcription factor HNF-4α. This strongly suggests that PGC-1α is the major factor mediating the fasting response of CYP2A5

  18. Reactivity estimation using digital nonlinear H∞ estimator for VHTRC experiment

    International Nuclear Information System (INIS)

    Suzuki, Katsuo; Nabeshima, Kunihiko; Yamane, Tsuyoshi

    2003-01-01

    On-line and real-time estimation of time-varying reactivity in a nuclear reactor in necessary for early detection of reactivity anomaly and safe operation. Using a digital nonlinear H ∞ estimator, an experiment of real-time dynamic reactivity estimation was carried out in the Very High Temperature Reactor Critical Assembly (VHTRC) of Japan Atomic Energy Research Institute. Some technical issues of the experiment are described, such as reactivity insertion, data sampling frequency, anti-aliasing filter, experimental circuit and digitalising nonlinear H ∞ reactivity estimator, and so on. Then, we discussed the experimental results obtained by the digital nonlinear H ∞ estimator with sampled data of the nuclear instrumentation signal for the power responses under various reactivity insertions. Good performances of estimated reactivity were observed, with almost no delay to the true reactivity and sufficient accuracy between 0.05 cent and 0.1 cent. The experiment shows that real-time reactivity for data sampling period of 10 ms can be certainly realized. From the results of the experiment, it is concluded that the digital nonlinear H ∞ reactivity estimator can be applied as on-line real-time reactivity meter for actual nuclear plants. (author)

  19. Manganese Transport and Toxicity in Polarized WIF-B Hepatocytes.

    Science.gov (United States)

    Thompson, Khristy J; Hein, Jennifer; Baez, Andrew; Sosa, Jose Carlo; Wessling-Resnick, Marianne

    2018-05-24

    Mn toxicity arises from nutritional problems, community and occupational exposures, and genetic risks. Mn blood levels are controlled by hepatobiliary clearance. The goals of this study were to determine the cellular distribution of Mn transporters in polarized hepatocytes, to establish an in vitro assay for hepatocyte Mn efflux, and to examine possible roles the Mn transporters would play in metal import and export. For these experiments, hepatocytoma WIF-B cells were grown for 12-14 days to achieve maximal polarity. Immunoblots showed that Mn transporters ZIP8, ZnT10, ferroportin (Fpn), and ZIP14 were present. Indirect immunofluorescence microscopy localized Fpn and ZIP14 to WIF-B cell basolateral domains while ZnT10 and ZIP8 associated with intracellular vesicular compartments. ZIP8-positive structures were distributed uniformly throughout the cytoplasm, but ZnT10-positive vesicles were adjacent to apical bile compartments. WIF-B cells were sensitive to Mn toxicity, showing decreased viability after 16 h exposure to > 250 M MnCl2. However, the hepatocytes were resistant to 4 h exposures of up to 500 M MnCl2 despite 50-fold increased Mn content. Washout experiments showed time-dependent efflux with 80% Mn released after a 4 h chase period. Hepcidin reduced levels of Fpn in WIF-B cells, clearing Fpn from the cell surface, but Mn efflux was unaffected. The secretory inhibitor brefeldin A did block release of Mn from WIF-B cells, suggesting vesicle fusion may be involved in export. These results point to a possible role of ZnT10 to import Mn into vesicles that subsequently fuse with the apical membrane and empty their contents into bile.

  20. Curcumin inhibits activation of TRPM2 channels in rat hepatocytes

    Directory of Open Access Journals (Sweden)

    E. Kheradpezhouh

    2016-04-01

    Full Text Available Oxidative stress is a hallmark of many liver diseases including viral and drug-induced hepatitis, ischemia-reperfusion injury, and non-alcoholic steatohepatitis. One of the consequences of oxidative stress in the liver is deregulation of Ca2+ homeostasis, resulting in a sustained elevation of the free cytosolic Ca2+ concentration ([Ca2+]c in hepatocytes, which leads to irreversible cellular damage. Recently it has been shown that liver damage induced by paracetamol and subsequent oxidative stress is, in large part, mediated by Ca2+ entry through Transient Receptor Potential Melastatin 2 (TRPM2 channels. Involvement of TRPM2 channels in hepatocellular damage induced by oxidative stress makes TRPM2 a potential therapeutic target for treatment of a range of oxidative stress-related liver diseases. We report here the identification of curcumin ((1E,6E-1,7-bis(4-hydroxy-3-methoxyphenyl-1,6-heptadiene-3,5-dione, a natural plant-derived polyphenol in turmeric spice, as a novel inhibitor of TRPM2 channel. Presence of 5 µM curcumin in the incubation medium prevented the H2O2- and paracetamol-induced [Ca2+]c rise in rat hepatocytes. Furthermore, in patch clamping experiments incubation of hepatocytes with curcumin inhibited activation of TRPM2 current by intracellular ADPR with IC50 of approximately 50 nM. These findings enhance understanding of the actions of curcumin and suggest that the known hepatoprotective properties of curcumin are, at least in part, mediated through inhibition of TRPM2 channels.

  1. Continuous reactivity calculation for subcritical system

    International Nuclear Information System (INIS)

    Silva, Cristiano; Goncalves, Alessandro C.; Martinez, Aquilino S.; Silva, Fernando C. da

    2011-01-01

    With the rise of a new generation of nuclear reactors as for existence the ADS (Accelerator-Driven System), it is important to have a fast and accurate prediction of the variation in reactivity during a possible variation in the intensity of external sources. This paper presents a formulation for the calculation of reactivity in subcritical systems using the inverse method related only to nuclear power derivatives. One of the applications of the proposed method is the possibility of developing reactimeters that allow the continuous monitoring of subcritical systems. (author)

  2. Continuous reactivity calculation for subcritical system

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cristiano; Goncalves, Alessandro C.; Martinez, Aquilino S.; Silva, Fernando C. da, E-mail: cristiano@herzeleid.net, E-mail: aquilino@lmp.ufrj.br, E-mail: fernando@con.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Palma, Daniel A.P., E-mail: dapalma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    With the rise of a new generation of nuclear reactors as for existence the ADS (Accelerator-Driven System), it is important to have a fast and accurate prediction of the variation in reactivity during a possible variation in the intensity of external sources. This paper presents a formulation for the calculation of reactivity in subcritical systems using the inverse method related only to nuclear power derivatives. One of the applications of the proposed method is the possibility of developing reactimeters that allow the continuous monitoring of subcritical systems. (author)

  3. Reactive Oxygen Species-Induced TXNIP Drives Fructose-Mediated Hepatic Inflammation and Lipid Accumulation Through NLRP3 Inflammasome Activation

    Science.gov (United States)

    Zhang, Xian; Zhang, Jian-Hua; Chen, Xu-Yang; Hu, Qing-Hua; Wang, Ming-Xing; Jin, Rui; Zhang, Qing-Yu; Wang, Wei; Wang, Rong; Kang, Lin-Lin; Li, Jin-Sheng; Li, Meng

    2015-01-01

    Abstract Aims: Increased fructose consumption predisposes the liver to nonalcoholic fatty liver disease (NAFLD), but the mechanisms are elusive. Thioredoxin-interacting protein (TXNIP) links oxidative stress to NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation and this signaling axis may be involved in fructose-induced NAFLD. Here, we explore the role of reactive oxygen species (ROS)-induced TXNIP overexpression in fructose-mediated hepatic NLRP3 inflammasome activation, inflammation, and lipid accumulation. Results: Rats were fed a 10% fructose diet for 8 weeks and treated with allopurinol and quercetin during the last 4 weeks. Five millimolars of fructose-exposed hepatocytes (primary rat hepatocytes, rat hepatic parenchymal cells [RHPCs], HLO2, HepG2) were co-incubated with antioxidants or caspase-1 inhibitor or subjected to TXNIP or NLRP3 siRNA interference. Fructose induced NLRP3 inflammasome activation and pro-inflammatory cytokine secretion, janus-activated kinase 2/signal transducers and activators of transcription 3-mediated inflammatory signaling, and expression alteration of lipid metabolism-related genes in cultured hepatocytes and rat livers. NLRP3 silencing and caspase-1 suppression blocked these effects in primary rat hepatocytes and RHPCs, confirming that inflammasome activation alters hepatocyte lipid metabolism. Hepatocellular ROS and TXNIP were increased in animal and cell models. TXNIP silencing blocked NLRP3 inflammasome activation, inflammation, and lipid metabolism perturbations but not ROS induction in fructose-exposed hepatocytes, whereas antioxidants addition abrogated TXNIP induction and diminished the detrimental effects in fructose-exposed hepatocytes and rat livers. Innovation and Conclusions: This study provides a novel mechanism for fructose-induced NAFLD pathogenesis by which the ROS-TXNIP pathway mediates hepatocellular NLRP3 inflammasome activation, inflammation and lipid accumulation. Antioxidant

  4. Reactive Kripke semantics

    CERN Document Server

    Gabbay, Dov M

    2013-01-01

    This text offers an extension to the traditional Kripke semantics for non-classical logics by adding the notion of reactivity. Reactive Kripke models change their accessibility relation as we progress in the evaluation process of formulas in the model. This feature makes the reactive Kripke semantics strictly stronger and more applicable than the traditional one. Here we investigate the properties and axiomatisations of this new and most effective semantics, and we offer a wide landscape of applications of the idea of reactivity. Applied topics include reactive automata, reactive grammars, rea

  5. Modeling Np and Pu transport with a surface complexation model and spatially variant sorption capacities: Implications for reactive transport modeling and performance assessments of nuclear waste disposal sites

    Science.gov (United States)

    Glynn, P.D.

    2003-01-01

    simulation conditions. Functional behaviors that cannot be fit include concentration trend reversals and radionuclide desorption spikes. Other simulation results are fit successfully but the fitted parameters (Kd and dispersivity) vary significantly depending on simulation conditions (e.g. "infiltration" vs. "cleanup" conditions). Notably, an increase in the variance of the specified sorption capacities results in a marked increase in the dispersion of the radionuclides. The results presented have implications for the simulation of radionuclide migration in performance assessments of nuclear waste-disposal sites, for the future monitoring of those sites, and more generally for modeling contaminant transport in ground-water environments. ?? 2003 Published by Elsevier Science Ltd.

  6. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

    Directory of Open Access Journals (Sweden)

    Elien Gevaert

    Full Text Available The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

  7. High Throughput Micro-Well Generation of Hepatocyte Micro-Aggregates for Tissue Engineering

    NARCIS (Netherlands)

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart A.; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the

  8. High efficient differentiation of functional hepatocytes from porcine induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Ying Ao

    Full Text Available Hepatocyte transplantation is considered to be a promising therapy for patients with liver diseases. Induced pluripotent stem cells (iPSCs provide an unlimited source for the generation of functional hepatocytes. In this study, we generated iPSCs from porcine ear fibroblasts (PEFs by overexpressing Sox2, Klf4, Oct4, and c-Myc (SKOM, and developed a novel strategy for the efficient differentiation of hepatocyte-like cells from porcine iPSCs by following the processes of early liver development. The differentiated cells displayed the phenotypes of hepatocytes, exhibited classic hepatocyte-associated bio-functions, such as LDL uptake, glycogen storage and urea secretion, as well as possessed the metabolic activities of cytochrome P-450 (CYP 3A and 2C. Furthermore, we compared the hepatocyte differentiation efficacy of our protocol with another published method, and the results demonstrated that our differentiation strategy could significantly improve the generation of morphological and functional hepatocyte-like cells from porcine iPSCs. In conclusion, this study establishes an efficient method for in vitro generation of functional hepatocytes from porcine iPSCs, which could represent a promising cell source for preclinical testing of cell-based therapeutics for liver failure and for pharmacological applications.

  9. Integrin-linked kinase is involved in matrix-induced hepatocyte differentiation

    International Nuclear Information System (INIS)

    Gkretsi, Vasiliki; Bowen, William C.; Yang, Yu; Wu, Chuanyue; Michalopoulos, George K.

    2007-01-01

    Hepatocytes have restricted proliferative capacity in culture and when cultured without matrix, lose the hepatocyte-specific gene expression and characteristic cellular micro-architecture. Overlay of matrix-preparations on de-differentiated hepatocytes restores differentiation. Integrin-linked kinase (ILK) is a cell-matrix-adhesion protein crucial in fundamental processes such as differentiation and survival. In this study, we investigated the role of ILK, and its binding partners PINCH, α-parvin, and Mig-2 in matrix-induced hepatocyte differentiation. We report here that ILK is present in the liver and localizes at cell-matrix adhesions of cultured hepatocytes. We also show that ILK, PINCH, α-parvin, and Mig-2 expression level is dramatically reduced in the re-differentiated hepatocytes. Interestingly, hepatocytes lacking ILK undergo matrix-induced differentiation but their differentiation is incomplete, as judged by monitoring cell morphology and production of albumin. Our results show that ILK and cell-matrix adhesion proteins play an important role in the process of matrix-induced hepatocyte differentiation

  10. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

    Science.gov (United States)

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

  11. Computational Topology Based Quantification Of Hepatocytes Nuclei In Lipopolysaccharide-Induced Liver Injury In Mice

    Directory of Open Access Journals (Sweden)

    Rodrigo Rojas Moraleda

    2016-06-01

    The computational topology approach proposed successfully detected hepatocyte cells under several natural variations. We evaluated on a per-pixel basis how the segmentation performs on: i all nuclei in the images, ii big round nuclei considered belonging to hepatocytes cells (accuracy 87.2%, recall 80.3%, and iii nuclei regarded to non-parenchymal cells.  

  12. Hepatic tissue environment in NEMO-deficient mice critically regulates positive selection of donor cells after hepatocyte transplantation.

    Directory of Open Access Journals (Sweden)

    Michaela Kaldenbach

    Full Text Available BACKGROUND: Hepatocyte transplantation (HT is a promising alternative treatment strategy for end-stage liver diseases compared with orthotopic liver transplantation. A limitation for this approach is the low engraftment of donor cells. The deletion of the I-kappa B kinase-regulatory subunit IKKγ/NEMO in hepatocytes prevents nuclear factor (NF-kB activation and triggers spontaneous liver apoptosis, chronic hepatitis and the development of liver fibrosis and hepatocellular carcinoma. We hypothesized that NEMOΔhepa mice may therefore serve as an experimental model to study HT. METHODS: Pre-conditioned NEMOΔhepa mice were transplanted with donor-hepatocytes from wildtype (WT and mice deficient for the pro-apoptotic mediator Caspase-8 (Casp8Δhepa. RESULTS: Transplantation of isolated WT-hepatocytes into pre-conditioned NEMOΔhepa mice resulted in a 6-7 fold increase of donor cells 12 weeks after HT, while WT-recipients showed no liver repopulation. The use of apoptosis-resistant Casp8Δhepa-derived donor cells further enhanced the selection 3-fold after 12-weeks and up to 10-fold increase after 52 weeks compared with WT donors. While analysis of NEMOΔhepa mice revealed strong liver injury, HT-recipient NEMOΔhepa mice showed improved liver morphology and decrease in serum transaminases. Concomitant with these findings, the histological examination elicited an improved liver tissue architecture associated with significantly lower levels of apoptosis, decreased proliferation and a lesser amount of liver fibrogenesis. Altogether, our data clearly support the therapeutic benefit of the HT procedure into NEMOΔhepa mice. CONCLUSION: This study demonstrates the feasibility of the NEMOΔhepa mouse as an in vivo tool to study liver repopulation after HT. The improvement of the characteristic phenotype of chronic liver injury in NEMOΔhepa mice after HT suggests the therapeutic potential of HT in liver diseases with a chronic inflammatory phenotype and

  13. Extracellular matrix components influence DNA synthesis of rat hepatocytes in primary culture

    International Nuclear Information System (INIS)

    Sawada, N.; Tomomura, A.; Sattler, C.A.; Sattler, G.L.; Kleinman, H.K.; Pitot, H.C.

    1986-01-01

    The effects of several extracellular matrix components (EMCs) - fibronectin (Fn), laminin (Ln), type I (C-I) and type IV (C-IV) collagen - on DNA synthesis in rat hepatocytes in primary culture were examined by both quantitative scintillation spectrometry and autoradiography of [ 3 H]thymidine incorporation. Hepatocytes cultured on Fn showed the most active DNA synthesis initiated by epidermal growth factor (EGF) with decreasing levels of [ 3 H]thymidine uptake exhibited in the cell cultured on C-IV, C-I, and Ln, respectively. The decreasing level of DNA synthesis in hepatocytes cultured on Fn, C-IV, C-I, and Ln respectively was not influenced by cell density. The number of EGF receptors of hepatocytes was also not influenced by EMCs. These data suggest that EMCs modify hepatocyte DNA synthesis by means of post-EGF-receptor mechanisms which are regulated by both growth factors and cell density

  14. Galactosylated DNA lipid nanocapsules for efficient hepatocyte targeting.

    Science.gov (United States)

    Morille, M; Passirani, C; Letrou-Bonneval, E; Benoit, J-P; Pitard, B

    2009-09-11

    The main objective of gene therapy via a systemic pathway is the development of a stable and non-toxic gene vector that can encapsulate and deliver foreign genetic materials into specific cell types with the transfection efficiency of viral vectors. With this objective, DNA complexed with cationic lipids of DOTAP/DOPE was encapsulated into lipid nanocapsules (LNCs) forming nanocarriers (DNA LNCs) with a size suitable for systemic injection (109+/-6 nm). With the goal of increasing systemic delivery, LNCs were stabilised with long chains of poly(ethylene glycol) (PEG), either from a PEG lipid derivative (DSPE-mPEG(2000)) or from an amphiphilic block copolymer (F108). In order to overcome internalisation difficulties encountered with PEG shield, a specific ligand (galactose) was covalently added at the distal end of the PEG chains, in order to provide active targeting of the asialoglycoprotein-receptor present on hepatocytes. This study showed that DNA LNCs were as efficient as positively charged DOTAP/DOPE lipoplexes for transfection. In primary hepatocytes, when non-galactosylated, the two polymers significantly decreased the transfection, probably by creating a barrier around the DNA LNCs. Interestingly, galactosylated F108 coated DNA LNCs led to a 18-fold increase in luciferase expression compared to non-galactosylated ones.

  15. Biotransformation of hydralazine (HDZ) in monolayer cultures of rabbit hepatocytes

    International Nuclear Information System (INIS)

    McQueen, C.A.; Rosado, R.R.

    1990-01-01

    Adverse reactions to HDZ have been associated with the acetylator polymorphism; slow acetylators are more likely to develop HDZ-induced lupus erythematosus. In studying the role of this polymorphism in susceptibility to HDZ toxicity, the biotransformation of HDZ was investigated in rabbit hepatocytes. New Zealand white rabbits, like humans, are classified as rapid or slow acetylators. Heptocytes were isolated from rapid acetylator rabbits by collagenase perfusion. Monolayer cultures were initiated and exposed to 14 C-HDZ. Since HDZ is unstable at neutral pH, parallel incubations were done in the absence of cells. Metabolites in the media were determined by reverse phase HPLC. Phthalazine (P), phthalazinone (PZ), triazoloph-thalazine (TP), methyl TP (MTP) and 3-hydroxy MTP were identified. In the absence of cells, more TP was formed than MTP, probably resulting from reaction of HDZ with components in the medium. In the presence of cells, there was a three-fold increase in MTP, while the amount of TP was relatively constant. Only trace amounts of P, PZ 3-hydroxy MTP were detected. These data indicate that monolayer cultures of rapid acetylator rabbit hepatocytes were capable of metabolizing HDZ with acetylation playing a major role. These studies are being extended to cells from slow acetylator rabbits

  16. Rapid and sensitive measure of gluconeogenesis in isolated bovine hepatocytes

    International Nuclear Information System (INIS)

    Azain, M.J.; Kasser, T.R.; Atwell, C.A.; Baile, C.A.

    1986-01-01

    Available methods for determining glucose synthesis from radiolabelled precursors using ion exchange column chromatography limit the number of samples that can be processed. To facilitate this process, a rapid method for determining glucose synthesis from 3-carbon precursors was developed using suspensions of anion and cation exchange resins. Hepatocytes were prepared from calf liver by collagenase perfusion of the caudate lobe. Isolated cells were incubated with 14 C-labelled lactate or propionate in the presence or absence of glucagen and/or palmitate. Glucose synthesis was determined by vortexing an aliquot of cell suspension with a 50% slurry of anion exchange resin (acetate form), followed by cation exchange resin. After centrifugation 14 C-glucose was recovered in the supernatant and measured by scintillation counting. Using this method, more than 95% of unused labelled precursor was bound to the ion exchange resin and essentially 100% of 14 C-glucose tracer was recovered in the supernatant. In hepatocyte suspensions, radioactivity recovered in the supernatants was confirmed to be glucose by pre-incubating aliquots of media with glucose oxidase prior to addition of ion exchange resins. The present system allows determination of hepatic gluconeogenesis, is sensitive to substrate and hormonal manipulations and has the capacity for processing several hundred samples per day

  17. Stimulation of glucose phosphorylation by fructose in isolated rat hepatocytes.

    Science.gov (United States)

    Van Schaftingen, E; Vandercammen, A

    1989-01-15

    The phosphorylation of glucose was measured by the formation of [3H]H2O from [2-3H]glucose in suspensions of freshly isolated rat hepatocytes. Fructose (0.2 mM) stimulated 2-4-fold the rate of phosphorylation of 5 mM glucose although not of 40 mM glucose, thus increasing the apparent affinity of the glucose phosphorylating system. A half-maximal stimulatory effect was observed at about 50 microM fructose. Stimulation was maximal 5 min after addition of the ketose and was stable for at least 40 min, during which period 60% of the fructose was consumed. The effect of fructose was reversible upon removal of the ketose. Sorbitol and tagatose were as potent as fructose in stimulating the phosphorylation of 5 mM glucose. D-Glyceraldehyde also had a stimulatory effect but at tenfold higher concentrations. In contrast, dihydroxyacetone had no significant effect and glycerol inhibited the detritiation of glucose. Oleate did not affect the phosphorylation of glucose, even in the presence of fructose, although it stimulated the formation of ketone bodies severalfold, indicating that it was converted to its acyl-CoA derivative. These results allow the conclusion that fructose stimulates glucokinase in the intact hepatocyte. They also suggest that this effect is mediated through the formation of fructose 1-phosphate, which presumably interacts with a competitive inhibitor of glucokinase other than long-chain acyl-CoAs.

  18. Hepatocytes polyploidization and cell cycle control in liver physiopathology.

    Science.gov (United States)

    Gentric, Géraldine; Desdouets, Chantal; Celton-Morizur, Séverine

    2012-01-01

    Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of "diploid-polyploid conversion" during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels), oxidative stress, toxic insult, and chronic hepatitis etc.). Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  19. Hepatocytes Polyploidization and Cell Cycle Control in Liver Physiopathology

    Directory of Open Access Journals (Sweden)

    Géraldine Gentric

    2012-01-01

    Full Text Available Most cells in mammalian tissues usually contain a diploid complement of chromosomes. However, numerous studies have demonstrated a major role of “diploid-polyploid conversion” during physiopathological processes in several tissues. In the liver parenchyma, progressive polyploidization of hepatocytes takes place during postnatal growth. Indeed, at the suckling-weaning transition, cytokinesis failure events induce the genesis of binucleated tetraploid liver cells. Insulin signalling, through regulation of the PI3K/Akt signalling pathway, is essential in the establishment of liver tetraploidization by controlling cytoskeletal organisation and consequently mitosis progression. Liver cell polyploidy is generally considered to indicate terminal differentiation and senescence, and both lead to a progressive loss of cell pluripotency associated to a markedly decreased replication capacity. Although adult liver is a quiescent organ, it retains a capacity to proliferate and to modulate its ploidy in response to various stimuli or aggression (partial hepatectomy, metabolic overload (i.e., high copper and iron hepatic levels, oxidative stress, toxic insult, and chronic hepatitis etc.. Here we review the mechanisms and functional consequences of hepatocytes polyploidization during normal and pathological liver growth.

  20. Metformin protects rat hepatocytes against bile acid-induced apoptosis.

    Directory of Open Access Journals (Sweden)

    Titia E Woudenberg-Vrenken

    Full Text Available BACKGROUND: Metformin is used in the treatment of Diabetes Mellitus type II and improves liver function in patients with non-alcoholic fatty liver disease (NAFLD. Metformin activates AMP-activated protein kinase (AMPK, the cellular energy sensor that is sensitive to changes in the AMP/ATP-ratio. AMPK is an inhibitor of mammalian target of rapamycin (mTOR. Both AMPK and mTOR are able to modulate cell death. AIM: To evaluate the effects of metformin on hepatocyte cell death. METHODS: Apoptotic cell death was induced in primary rat hepatocytes using either the bile acid glycochenodeoxycholic acid (GCDCA or TNFα in combination with actinomycin D (actD. AMPK, mTOR and phosphoinositide-3 kinase (PI3K/Akt were inhibited using pharmacological inhibitors. Apoptosis and necrosis were quantified by caspase activation, acridine orange staining and Sytox green staining respectively. RESULTS: Metformin dose-dependently reduces GCDCA-induced apoptosis, even when added 2 hours after GCDCA, without increasing necrotic cell death. Metformin does not protect against TNFα/ActD-induced apoptosis. The protective effect of metformin is dependent on an intact PI3-kinase/Akt pathway, but does not require AMPK/mTOR-signaling. Metformin does not inhibit NF-κB activation. CONCLUSION: Metformin protects against bile acid-induced apoptosis and could be considered in the treatment of chronic liver diseases accompanied by inflammation.

  1. Reactive perforating collagenosis

    Directory of Open Access Journals (Sweden)

    Yadav Mukesh

    2009-01-01

    Full Text Available Reactive perforating collagenosis is a rare cutaneous disorder of unknown etiology. We hereby describe a case of acquired reactive perforating collagenosis in a patient of diabetes and chronic renal failure.

  2. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Directory of Open Access Journals (Sweden)

    Marco De Santis Puzzonia

    Full Text Available In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  3. TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

    Science.gov (United States)

    De Santis Puzzonia, Marco; Cozzolino, Angela Maria; Grassi, Germana; Bisceglia, Francesca; Strippoli, Raffaele; Guarguaglini, Giulia; Citarella, Franca; Sacchetti, Benedetto; Tripodi, Marco; Marchetti, Alessandra; Amicone, Laura

    2016-01-01

    In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

  4. Decrease in Dengue virus-2 infection and reduction of cytokine/chemokine production by Uncaria guianensis in human hepatocyte cell line Huh-7

    Directory of Open Access Journals (Sweden)

    Cíntia da Silva Mello

    Full Text Available ABSTRACT BACKGROUND Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL and bark (UGB of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV infection and in immunological parameters associated with in vivo physiopathological features. METHODS Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7 were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA or flow cytometry. FINDINGS The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1, which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL. MAIN CONCLUSIONS The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.

  5. Decrease in Dengue virus-2 infection and reduction of cytokine/chemokine production by Uncaria guianensis in human hepatocyte cell line Huh-7.

    Science.gov (United States)

    Mello, Cíntia da Silva; Valente, Ligia Maria Marino; Wolff, Thiago; Lima-Junior, Raimundo Sousa; Fialho, Luciana Gomes; Marinho, Cintia Ferreira; Azeredo, Elzinandes Leal; Oliveira-Pinto, Luzia Maria; Pereira, Rita de Cássia Alves; Siani, Antonio Carlos; Kubelka, Claire Fernandes

    2017-06-01

    Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL) and bark (UGB) of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV) infection and in immunological parameters associated with in vivo physiopathological features. Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7) were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA) or flow cytometry. The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1), which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL. MAIN. The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.

  6. Reactivity on the Web

    OpenAIRE

    Bailey, James; Bry, François; Eckert, Michael; Patrânjan, Paula Lavinia

    2005-01-01

    Reactivity, the ability to detect simple and composite events and respond in a timely manner, is an essential requirement in many present-day information systems. With the emergence of new, dynamic Web applications, reactivity on the Web is receiving increasing attention. Reactive Web-based systems need to detect and react not only to simple events but also to complex, real-life situations. This paper introduces XChange, a language for programming reactive behaviour on the Web,...

  7. Monadic Functional Reactive Programming

    NARCIS (Netherlands)

    A.J. van der Ploeg (Atze); C Shan

    2013-01-01

    htmlabstractFunctional Reactive Programming (FRP) is a way to program reactive systems in functional style, eliminating many of the problems that arise from imperative techniques. In this paper, we present an alternative FRP formulation that is based on the notion of a reactive computation: a

  8. Controlled cell morphology and liver-specific function of engineered primary hepatocytes by fibroblast layer cell densities.

    Science.gov (United States)

    Sakai, Yusuke; Koike, Makiko; Kawahara, Daisuke; Hasegawa, Hideko; Murai, Tomomi; Yamanouchi, Kosho; Soyama, Akihiko; Hidaka, Masaaki; Takatsuki, Mitsuhisa; Fujita, Fumihiko; Kuroki, Tamotsu; Eguchi, Susumu

    2018-03-05

    Engineered primary hepatocytes, including co-cultured hepatocyte sheets, are an attractive to basic scientific and clinical researchers because they maintain liver-specific functions, have reconstructed cell polarity, and have high transplantation efficiency. However, co-culture conditions regarding engineered primary hepatocytes were suboptimal in promoting these advantages. Here we report that the hepatocyte morphology and liver-specific function levels are controlled by the normal human diploid fibroblast (TIG-118 cell) layer cell density. Primary rat hepatocytes were plated onto TIG-118 cells, previously plated 3 days before at 1.04, 5.21, and 26.1×10 3  cells/cm 2 . Hepatocytes plated onto lower TIG-118 cell densities expanded better during the early culture period. The hepatocytes gathered as colonies and only exhibited small adhesion areas because of the pushing force from proliferating TIG-118 cells. The smaller areas of each hepatocyte result in the development of bile canaliculi. The highest density of TIG-118 cells downregulated albumin synthesis activity of hepatocytes. The hepatocytes may have undergone apoptosis associated with high TGF-β1 concentration and necrosis due to a lack of oxygen. These occurrences were supported by apoptotic chromatin condensation and high expression of both proteins HIF-1a and HIF-1b. Three types of engineered hepatocyte/fibroblast sheets comprising different TIG-118 cell densities were harvested after 4 days of hepatocyte culture and showed a complete cell sheet format without any holes. Hepatocyte morphology and liver-specific function levels are controlled by TIG-118 cell density, which helps to design better engineered hepatocytes for future applications such as in vitro cell-based assays and transplantable hepatocyte tissues. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Digital reactivity meter

    International Nuclear Information System (INIS)

    Akkus, B.; Anac, H.; Alsan, S.; Erk, S.

    1991-01-01

    Nowadays, various digital methods making use of microcomputers for neutron detector signals and determining the reactivity by numerical calculations are used in reactor control systems in place of classical reactivity meters. In this work, a calculation based on the ''The Time Dependent Transport Equation'' has been developed for determining the reactivity numerically. The reactivity values have been obtained utilizing a computer-based data acquisition and control system and compared with the analog reactivity meter values as well as the values calculated from the ''Inhour Equation''

  10. Evidence of a DHA Signature in the Lipidome and Metabolome of Human Hepatocytes

    Directory of Open Access Journals (Sweden)

    Veronica Ghini

    2017-02-01

    Full Text Available Cell supplementation with bioactive molecules often causes a perturbation in the whole intracellular environment. Omics techniques can be applied for the assessment of this perturbation. In this study, the overall effect of docosahexaenoic acid (DHA supplementation on cultured human hepatocyte lipidome and metabolome has been investigated using nuclear magnetic resonance (NMR in combination with traditional techniques. The effect of two additional bioactives sharing with DHA the lipid-lowering effect—propionic acid (PRO and protocatechuic acid (PCA—has also been evaluated in the context of possible synergism. NMR analysis of the cell lipid extracts showed that DHA supplementation, alone or in combination with PCA or PRO, strongly altered the cell lipid profile. The perfect discrimination between cells receiving DHA (alone or in combination and the other cells reinforced the idea of a global rearrangement of the lipid environment induced by DHA. Notably, gas chromatography and fluorimetric analyses confirmed the strong discrimination obtained by NMR. The DHA signature was evidenced not only in the cell lipidome, but also in the metabolome. Results reported herein indicate that NMR, combined with other techniques, represents a fundamental approach to studying the effect of bioactive supplementation, particularly in the case of molecules with a broad spectrum of mechanisms of action.

  11. Cellular and molecular etiology of hepatocyte injury in a murine model of environmentally induced liver abnormality

    Directory of Open Access Journals (Sweden)

    M.A. Al-Griw

    2016-09-01

    Full Text Available Exposures to a wide variety of environmental substances are negatively associated with many biological cell systems both in humans and rodents. Trichloroethane (TCE, a ubiquitous environmental toxicant, is used in large quantities as a dissolvent, metal degreaser, chemical intermediate, and component of consumer products. This increases the likelihood of human exposure to these compounds through dermal, inhalation and oral routes. The present in vivo study was aimed to investigate the possible cellular and molecular etiology of liver abnormality induced by early exposure to TCE using a murine model. The results showed a significant increase in liver weight. Histopathological examination revealed a TCE-induced hepatotoxicity which appeared as heavily congested central vein and blood sinusoids as well as leukocytic infiltration. Mitotic figures and apoptotic changes such as chromatin condensation and nuclear fragments were also identified. Cell death analysis demonstrates hepatocellular apoptosis was evident in the treated mice compared to control. TCE was also found to induce oxidative stress as indicated by an increase in the levels of lipid peroxidation, an oxidative stress marker. There was also a significant decrease in the DNA content of the hepatocytes of the treated groups compared to control. Agarose gel electrophoresis also provided further biochemical evidence of apoptosis by showing internucleosomal DNA fragmentation in the liver cells, indicating oxidative stress as the cause of DNA damage. These results suggest the need for a complete risk assessment of any new chemical prior to its arrival into the consumer market.

  12. Method of controlling reactivity

    International Nuclear Information System (INIS)

    Tochihara, Hiroshi.

    1982-01-01

    Purpose: To improve the reactivity controlling characteristics by artificially controlling the leakage of neutron from a reactor and providing a controller for controlling the reactivity. Method: A reactor core is divided into several water gaps to increase the leakage of neutron, its reactivity is reduced, a gas-filled control rod or a fuel assembly is inserted into the gap as required, the entire core is coupled in a system to reduce the leakage of the neutron, and the reactivity is increased. The reactor shutdown is conducted by the conventional control rod, and to maintain critical state, boron density varying system is used together. Futher, a control rod drive is used with that similar to the conventional one, thereby enabling fast reactivity variation, and the positive reactivity can be obtained by the insertion, thereby improving the reactivity controlling characteristics. (Yoshihara, H.)

  13. Transplant of Hepatocytes, Undifferentiated Mesenchymal Stem Cells, and In Vitro Hepatocyte-Differentiated Mesenchymal Stem Cells in a Chronic Liver Failure Experimental Model: A Comparative Study.

    Science.gov (United States)

    El Baz, Hanan; Demerdash, Zeinab; Kamel, Manal; Atta, Shimaa; Salah, Faten; Hassan, Salwa; Hammam, Olfat; Khalil, Heba; Meshaal, Safa; Raafat, Inas

    2018-02-01

    Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure. Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed. Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group. Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.

  14. Circadian rhythms of Per2::Luc in individual primary mouse hepatocytes and cultures.

    Directory of Open Access Journals (Sweden)

    Casey J Guenthner

    Full Text Available BACKGROUND: Hepatocytes, the parenchymal cells of the liver, express core clock genes, such as Period2 and Cryptochrome2, which are involved in the transcriptional/translational feedback loop of the circadian clock. Whether or not the liver is capable of sustaining rhythms independent of a central pacemaker is controversial. Whether and how circadian information may be shared among cells in the liver in order to sustain oscillations is currently unknown. RESULTS: In this study we isolated primary hepatocytes from transgenic Per2(Luc mice and used bioluminescence as a read-out of the state of the circadian clock. Hepatocytes cultured in a collagen gel sandwich configuration exhibited persistent circadian rhythms for several weeks. The amplitude of the rhythms damped, but medium changes consistently reset the phase and amplitude of the cultures. Cry2(-/- Per2(Luc cells oscillated robustly and expressed a longer period. Co-culturing with wildtype cells did not significantly shorten the period, indicating that coupling among hepatocytes is insufficient to synchronize cells with significantly differing periods. However, spatial patterns revealed by cellular imaging of wildtype cultures provided evidence of weak local coupling among the hepatocytes. CONCLUSIONS: Our results with primary hepatocyte cultures demonstrate that cultured hepatocytes are weakly coupled. While this coupling is not sufficient to sustain global synchrony, it does increase local synchrony, which may stabilize the circadian rhythms of peripheral oscillators, such as the liver, against noise in the entraining signals.

  15. Sodium-independent, bicuculline-sensitive [3H]GABA binding to isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Minuk, G.Y.; Bear, C.E.; Sarjeant, E.J.

    1987-01-01

    To determine whether hepatocytes possess specific receptor sites for gamma-aminobutyric acid (GABA), a potent amino acid neurotransmitter, [ 3 H]GABA, was added to sodium-free suspensions of Percoll-purified hepatocytes derived from collagenase-perfused rat livers under various experimental conditions and in the presence or absence of specific GABA receptor agonists (muscimol) and antagonists (bicuculline). The effects of GABA, muscimol, and bicuculline on hepatocyte resting membrane potentials were also determined. Specific binding of [ 3 H]GABA to hepatocytes was a consistent finding. GABA-hepatocyte interactions were reversible and temperature dependent. Muscimol and bicuculline inhibited binding in a dose-dependent manner (IC50, 30 nM and 50 microM, respectively), whereas strychnine (1.0-100 microM), a nonspecific central nervous system stimulant, had no appreciable effect. Both GABA and muscimol (100 microM) caused significant hyperpolarization of hepatocyte resting membrane potential (delta PD 5.4 +/- 3.1 and 22.2 +/- 16.2 mV, respectively, means +/- SD, P less than 0.0005). Bicuculline (100 microM) inhibited the effect of muscimol (P less than 0.05). The results of this study suggest that specific GABA receptor sites exist on the surface of isolated rat hepatocytes. The presence of such sites raises the possibility that, in addition to adrenergic and cholinergic innervation, hepatic function may be influenced by GABA-ergic neurotransmitter mechanisms

  16. Dendritic cells and hepatocytes use distinct pathways to process protective antigen from plasmodium in vivo.

    Directory of Open Access Journals (Sweden)

    Ian A Cockburn

    2011-03-01

    Full Text Available Malaria-protective CD8+ T cells specific for the circumsporozoite (CS protein are primed by dendritic cells (DCs after sporozoite injection by infected mosquitoes. The primed cells then eliminate parasite liver stages after recognizing the CS epitopes presented by hepatocytes. To define the in vivo processing of CS by DCs and hepatocytes, we generated parasites carrying a mutant CS protein containing the H-2K(b epitope SIINFEKL, and evaluated the T cell response using transgenic and mutant mice. We determined that in both DCs and hepatocytes CS epitopes must reach the cytosol and use the TAP transporters to access the ER. Furthermore, we used endosomal mutant (3d and cytochrome c treated mice to address the role of cross-presentation in the priming and effector phases of the T cell response. We determined that in DCs, CS is cross-presented via endosomes while, conversely, in hepatocytes protein must be secreted directly into the cytosol. This suggests that the main targets of protective CD8+ T cells are parasite proteins exported to the hepatocyte cytosol. Surprisingly, however, secretion of the CS protein into hepatocytes was not dependent upon parasite-export (Pexel/VTS motifs in this protein. Together, these results indicate that the presentation of epitopes to CD8+ T cells follows distinct pathways in DCs when the immune response is induced and in hepatocytes during the effector phase.

  17. Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

    Science.gov (United States)

    Wang, Weimin; Cheng, Yan; Makarov, Edward; Ganesan, Murali; Gebhart, Catherine L.; Gorantla, Santhi; Osna, Natalia

    2018-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper. PMID:29361613

  18. Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

    Directory of Open Access Journals (Sweden)

    Raghubendra Singh Dagur

    2018-02-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper.

  19. Cell therapy from bench to bedside: Hepatocytes from fibroblasts - the truth and myth of transdifferentiation.

    Science.gov (United States)

    Sanal, Madhusudana Girija

    2015-06-07

    Hepatocyte transplantation is an alternative to liver transplantation in certain disorders such as inherited liver diseases and liver failure. It is a relatively less complicated surgical procedure, and has the advantage that it can be repeated several times if unsuccessful. Another advantage is that hepatocytes can be isolated from partly damaged livers which are not suitable for liver transplantation. Despite these advantages hepatocyte transplantation is less popular. Important issues are poor engraftment of the transplanted cells and the scarcity of donor hepatocytes. Generation of "hepatocyte like cells"/iHeps from embryonic stem cells (ES) and induced pluripotent stem cells (iPSCs) by directed differentiation is an emerging solution to the latter issue. Direct conversation or trans-differentiation of fibroblasts to "hepatocyte like cells" is another way which is, being explored. However this method has several inherent and technical disadvantages compared to the directed differentiation from ES or iPSC. There are several methods claiming to be "highly efficient" for generating "highly functional" "hepatocyte like cells". Currently different groups are working independently and coming up with differentiation protocols and each group claiming an advantage for their protocol. Directed differentiation protocols need to be designed, compared, analyzed and tweaked systematically and logically than empirically. There is a need for a well-coordinated global initiative comparable to the Human Genome Project to achieve this goal in the near future.

  20. Dual-energy precursor and nuclear erythroid-related factor 2 activator treatment additively improve redox glutathione levels and neuron survival in aging and Alzheimer mouse neurons upstream of reactive oxygen species.

    Science.gov (United States)

    Ghosh, Debolina; LeVault, Kelsey R; Brewer, Gregory J

    2014-01-01

    To determine whether glutathione (GSH) loss or increased reactive oxygen species (ROS) are more important to neuron loss, aging, and Alzheimer's disease (AD), we stressed or boosted GSH levels in neurons isolated from aging 3xTg-AD neurons compared with those from age-matched nontransgenic (non-Tg) neurons. Here, using titrating with buthionine sulfoximine, an inhibitor of γ-glutamyl cysteine synthetase (GCL), we observed that GSH depletion increased neuronal death of 3xTg-AD cultured neurons at increasing rates across the age span, whereas non-Tg neurons were resistant to GSH depletion until old age. Remarkably, the rate of neuron loss with ROS did not increase in old age and was the same for both genotypes, which indicates that cognitive deficits in the AD model were not caused by ROS. Therefore, we targeted for neuroprotection activation of the redox sensitive transcription factor, nuclear erythroid-related factor 2 (Nrf2) by 18 alpha glycyrrhetinic acid to stimulate GSH synthesis through GCL. This balanced stimulation of a number of redox enzymes restored the lower levels of Nrf2 and GCL seen in 3xTg-AD neurons compared with those of non-Tg neurons and promoted translocation of Nrf2 to the nucleus. By combining the Nrf2 activator together with the NADH precursor, nicotinamide, we increased neuron survival against amyloid beta stress in an additive manner. These stress tests and neuroprotective treatments suggest that the redox environment is more important for neuron survival than ROS. The dual neuroprotective treatment with nicotinamide and an Nrf2 inducer indicates that these age-related and AD-related changes are reversible. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. 3D hepatic cultures simultaneously maintain primary hepatocyte and liver sinusoidal endothelial cell phenotypes.

    Directory of Open Access Journals (Sweden)

    Yeonhee Kim

    Full Text Available Developing in vitro engineered hepatic tissues that exhibit stable phenotype is a major challenge in the field of hepatic tissue engineering. However, the rapid dedifferentiation of hepatic parenchymal (hepatocytes and non-parenchymal (liver sinusoidal endothelial, LSEC cell types when removed from their natural environment in vivo remains a major obstacle. The primary goal of this study was to demonstrate that hepatic cells cultured in layered architectures could preserve or potentially enhance liver-specific behavior of both cell types. Primary rat hepatocytes and rat LSECs (rLSECs were cultured in a layered three-dimensional (3D configuration. The cell layers were separated by a chitosan-hyaluronic acid polyelectrolyte multilayer (PEM, which served to mimic the Space of Disse. Hepatocytes and rLSECs exhibited several key phenotypic characteristics over a twelve day culture period. Immunostaining for the sinusoidal endothelial 1 antibody (SE-1 demonstrated that rLSECs cultured in the 3D hepatic model maintained this unique feature over twelve days. In contrast, rLSECs cultured in monolayers lost their phenotype within three days. The unique stratified structure of the 3D culture resulted in enhanced heterotypic cell-cell interactions, which led to improvements in hepatocyte functions. Albumin production increased three to six fold in the rLSEC-PEM-Hepatocyte cultures. Only rLSEC-PEM-Hepatocyte cultures exhibited increasing CYP1A1/2 and CYP3A activity. Well-defined bile canaliculi were observed only in the rLSEC-PEM-Hepatocyte cultures. Together, these data suggest that rLSEC-PEM-Hepatocyte cultures are highly suitable models to monitor the transformation of toxins in the liver and their transport out of this organ. In summary, these results indicate that the layered rLSEC-PEM-hepatocyte model, which recapitulates key features of hepatic sinusoids, is a potentially powerful medium for obtaining comprehensive knowledge on liver metabolism

  2. Peroxisomal abnormalities in the immortalized human hepatocyte (IHH) cell line.

    Science.gov (United States)

    Klouwer, Femke C C; Koster, Janet; Ferdinandusse, Sacha; Waterham, Hans R

    2017-04-01

    The immortalized human hepatocyte (IHH) cell line is increasingly used for studies related to liver metabolism, including hepatic glucose, lipid, lipoprotein and triglyceride metabolism, and the effect of therapeutic interventions. To determine whether the IHH cell line is a good model to investigate hepatic peroxisomal metabolism, we measured several peroxisomal parameters in IHH cells and, for comparison, HepG2 cells and primary skin fibroblasts. This revealed a marked plasmalogen deficiency and a deficient fatty acid α-oxidation in the IHH cells, due to a defect of PEX7, a cytosolic receptor protein required for peroxisomal import of a subset of peroxisomal proteins. These abnormalities have consequences for the lipid homeostasis of these cells and thus should be taken into account for the interpretation of data previously generated by using this cell line and when considering using this cell line for future research.

  3. Hepatocyte growth factor inhibitor-2 prevents shedding of matritpase

    DEFF Research Database (Denmark)

    Larsen, Brian R; Steffensen, Simon D; Nielsen, Nis V L

    2013-01-01

    Hepatocyte growth factor activator inhibitor-2 (HAI-2) is an inhibitor of many proteases in vitro, including the membrane-bound serine protease, matriptase. Studies of knock-out mice have shown that HAI-2 is essential for placental development only in mice expressing matriptase, suggesting that HAI......-2 is important for regulation of matriptase. Previous studies have shown that recombinant expression of matriptase was unsuccessful unless co-expressed with another HAI, HAI-1. In the present study we show that when human matriptase is recombinantly expressed alone in the canine cell line MDCK......, then human matriptase mRNA can be detected and the human matriptase ectodomain is shed to the media, suggesting that matriptase expressed alone is rapidly transported through the secretory pathway and shed. Whereas matriptase expressed together with HAI-1 or HAI-2 accumulates on the plasma membrane where...

  4. Interaction of propionate and carnitine metabolism in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Brass, E.P.; Beyerinck, R.A.

    1987-01-01

    Propionate (P) and its metabolic products P-CoA and methylmalonyl-CoA can disrupt normal hepatic metabolism. Carnitine (Cn) has been shown to partially restore cellular function in the presence of P. This effect of Cn may result from removal of propionyl groups as propionylcarnitine (P-Cn). The present study examined the kinetics of P-Cn formation in rat hepatocytes, and the consequence of P-Cn formation on P and Cn metabolism. 14 C-P was converted to CO 2 , glucose and P-Cn in the hepatocyte system. Increasing concentrations of Cn up to 10.0 mM increased P-Cn formation from P without affecting CO 2 or glucose formation. Thus, 10.0 mM Cn increased total P metabolism by 40%. Metabolism of P was associated with a decrease in Cn concentration and an increase in short chain acylcarnitines (SCCn). In the absence of added Cn, 60 min incubation with P decreased Cn from 6.8 to 2.5 μM with a corresponding increase in SCCn. This effect of P to deplete free Cn was not seen to the same degree with butyrate in place of P. Similar increases in the formation of SCCn in the presence of P at the expense of free Cn were seen when the incubation Cn concentration was increased to 50 μM or 150 μM. HPLC methodologies to study specific acylcarnitines demonstrated the accumulation of large amounts of P-Cn in the incubations containing P, accounting for the depletion of free Cn

  5. Glycogen synthase activation by sugars in isolated hepatocytes.

    Science.gov (United States)

    Ciudad, C J; Carabaza, A; Bosch, F; Gòmez I Foix, A M; Guinovart, J J

    1988-07-01

    We have investigated the activation by sugars of glycogen synthase in relation to (i) phosphorylase a activity and (ii) changes in the intracellular concentration of glucose 6-phosphate and adenine nucleotides. All the sugars tested in this work present the common denominator of activating glycogen synthase. On the other hand, phosphorylase a activity is decreased by mannose and glucose, unchanged by galactose and xylitol, and increased by tagatose, glyceraldehyde, and fructose. Dihydroxyacetone exerts a biphasic effect on phosphorylase. These findings provide additional evidence proving that glycogen synthase can be activated regardless of the levels of phosphorylase a, clearly establishing that a nonsequential mechanism for the activation of glycogen synthase occurs in liver cells. The glycogen synthase activation state is related to the concentrations of glucose 6-phosphate and adenine nucleotides. In this respect, tagatose, glyceraldehyde, and fructose deplete ATP and increase AMP contents, whereas glucose, mannose, galactose, xylitol, and dihydroxyacetone do not alter the concentration of these nucleotides. In addition, all these sugars, except glyceraldehyde, increase the intracellular content of glucose 6-phosphate. The activation of glycogen synthase by sugars is reflected in decreases on both kinetic constants of the enzyme, M0.5 (for glucose 6-phosphate) and S0.5 (for UDP-glucose). We propose that hepatocyte glycogen synthase is activated by monosaccharides by a mechanism triggered by changes in glucose 6-phosphate and adenine nucleotide concentrations which have been described to modify glycogen synthase phosphatase activity. This mechanism represents a metabolite control of the sugar-induced activation of hepatocyte glycogen synthase.

  6. Reactive Programming in Java

    CERN Document Server

    CERN. Geneva

    2017-01-01

    Reactive Programming in gaining a lot of excitement. Many libraries, tools, and frameworks are beginning to make use of reactive libraries. Besides, applications dealing with big data or high frequency data can benefit from this programming paradigm. Come to this presentation to learn about what reactive programming is, what kind of problems it solves, how it solves them. We will take an example oriented approach to learning the programming model and the abstraction.

  7. Impaired mitochondrial functions contribute to 3-bromopyruvate toxicity in primary rat and mouse hepatocytes

    Czech Academy of Sciences Publication Activity Database

    Sobotka, O.; Endlicher, R.; Drahota, Zdeněk; Kučera, O.; Rychtrmoc, D.; Raad, M.; Hakeem, K.; Červinková, Z.

    2016-01-01

    Roč. 48, č. 4 (2016), s. 363-373 ISSN 0145-479X Institutional support: RVO:67985823 Keywords : 3-bromopyruvate * toxicity * liver * hepatocyte * mitochondria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.576, year: 2016

  8. SELENIUM MODIFIES THE METABOLISM AND TOXICITY OF ARSENIC IN PRIMARY RAT HEPATOCYTES

    Science.gov (United States)

    ABSTRACTSelenium Modifies the Metabolism and Toxicity of Arsenic in Primary Rat Hepatocytes. Miroslav Styblo, David J. Thomas (2000) Toxicol. Appl. Pharmacol. Arsenic and selenium are metalloids with similar chemical properties and metabolic fates. Inorganic arsenic (iAs...

  9. DHA down-regulates phenobarbital-induced cytochrome P450 2B1 gene expression in rat primary hepatocytes by attenuating CAR translocation

    International Nuclear Information System (INIS)

    Li, C.-C.; Lii, C.-K.; Liu, K.-L.; Yang, J.-J.; Chen, H.-W.

    2007-01-01

    The constitutive androstane receptor (CAR) plays an important role in regulating the expression of detoxifying enzymes, including cytochrome P450 2B (CYP 2B). Phenobarbital (PB) induction of human CYP 2B6 and mouse CYP 2b10 has been shown to be mediated by CAR. Our previous study showed that PB-induced CYP 2B1 expression in rat primary hepatocytes is down-regulated by both n-6 and n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA); however, the mechanism for this down-regulation by DHA was previously unknown. The objective of the present study was to determine whether change in CAR translocation is involved in the down-regulation by n-6 and n-3 PUFAs of PB-induced CYP 2B1 expression in rat primary hepatocytes. We used 100 μM arachidonic acid, linoleic acid, eicosapentaenoic acid, and DHA to test this hypothesis. PB triggered the translocation of CAR from the cytosol into the nucleus in a dose-dependent and time-dependent manner in our hepatocyte system, and the CAR distribution in rat primary hepatocytes was significantly affected by DHA. DHA treatment decreased PB-inducible accumulation of CAR in the nuclear fraction and increased it in the cytosolic fraction in a dose-dependent manner. The down-regulation of CYP 2B1 expression by DHA occurred in a dose-dependent manner, and a similar pattern was found for the nuclear accumulation of CAR. The results of immunoprecipitation showed a CAR/RXR heterodimer bound to nuclear receptor binding site 1 (NR-1) of the PB-responsive enhancer module (PBREM) of the CYP 2B1gene. The EMSA results showed that PB-induced CAR binding to NR-1 was attenuated by DHA. Taken together, these results suggest that attenuation of CAR translocation and decreased subsequent binding to NR-1 are involved in DHA's down-regulation of PB-induced CYP 2B1 expression

  10. Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis.

    Science.gov (United States)

    Calabro, Sarah R; Maczurek, Annette E; Morgan, Alison J; Tu, Thomas; Wen, Victoria W; Yee, Christine; Mridha, Auvro; Lee, Maggie; d'Avigdor, William; Locarnini, Stephen A; McCaughan, Geoffrey W; Warner, Fiona J; McLennan, Susan V; Shackel, Nicholas A

    2014-01-01

    The classical paradigm of liver injury asserts that hepatic stellate cells (HSC) produce, remodel and turnover the abnormal extracellular matrix (ECM) of fibrosis via matrix metalloproteinases (MMPs). In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC. Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention. In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14) increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls. We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be targeted by

  11. Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis.

    Directory of Open Access Journals (Sweden)

    Sarah R Calabro

    Full Text Available The classical paradigm of liver injury asserts that hepatic stellate cells (HSC produce, remodel and turnover the abnormal extracellular matrix (ECM of fibrosis via matrix metalloproteinases (MMPs. In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC.Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention.In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14 increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls.We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be

  12. A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

    Energy Technology Data Exchange (ETDEWEB)

    Brückner, Sandra, E-mail: sandra.brueckner@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Tautenhahn, Hans-Michael, E-mail: hans-michael.tautenhahn@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103 (Germany); Winkler, Sandra, E-mail: sandra.pelz@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Stock, Peggy, E-mail: peggy.stock@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Dollinger, Matthias, E-mail: matthias.dollinger@uniklinik-ulm.de [University Hospital Ulm, First Department of Medicine, Albert-Einstein-Allee 23, Ulm D-89081 (Germany); Christ, Bruno, E-mail: bruno.christ@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103 (Germany)

    2014-02-15

    Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention in the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte

  13. A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

    International Nuclear Information System (INIS)

    Brückner, Sandra; Tautenhahn, Hans-Michael; Winkler, Sandra; Stock, Peggy; Dollinger, Matthias; Christ, Bruno

    2014-01-01

    Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention in the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte

  14. Activation of MEK 1/2 and p42/44 MAPK by Angiotensin II in Hepatocyte Nucleus and their Potentiation by Ethanol

    Science.gov (United States)

    Aroor, Annayya R.; Lee, Youn Ju; Shukla, Shivendra D.

    2009-01-01

    Hepato-subcellular effect of Ang II and ethanol on the p42/44 MAP Kinase and MEK1/2 were investigated in the nucleus of rat hepatocytes. Hepatocytes were treated with ethanol (100 mM) for 24 hr and stimulated with angiotensin II (Ang II, 100 nM, 5 min). The levels of p42/44 MAPK and MEK1/2 were monitored in the nuclear fraction using antibodies. Ang II itself caused significant accumulation of phospho-p42/44 MAPK in the nucleus without any significant translocation of p42/44 MAPK protein there by suggesting activation of p42/44 MAPK in the nucleus. Ang II caused marked accumulation of phospho-MEK 1/2 in the nucleus without any significant accumulation of MEK1/2 protein. Ratio of phospho-MEK 1/2 to MEK 1/2 protein in the nucleus after Ang II treatment was 2.4 times greater than control suggesting phosphorylation of MEK 1/2 inside the nucleus. Ethanol had no effect on the protein level or the activation of p42/44 MAPK in the nucleus. Ethanol treatment potentiated nuclear activation of p42/44 MPAK by Ang II but not translocation of p42/44 MAPK protein. This was accompanied by potentiation of Ang II stimulated accumulation of phospho-MEK 1/2 in the nucleus by ethanol. MEK 1/2 inhibitor, U-0126 inhibited Ang II response or its potentiation by ethanol. These results suggest that Ang II mediated accumulation of phospho-p42/44 MAPK in the hepatocyte nucleus involves MEK 1/2 dependent activation and this effect is potentiated by ethanol. PMID:19560630

  15. Arctigenin protects against steatosis in WRL68 hepatocytes through activation of phosphoinositide 3-kinase/protein kinase B and AMP-activated protein kinase pathways.

    Science.gov (United States)

    Chen, Kung-Yen; Lin, Jui-An; Yao, Han-Yun; Hsu, An-Chih; Tai, Yu-Ting; Chen, Jui-Tai; Hsieh, Mao-Chih; Shen, Tang-Long; Hsu, Ren-Yi; Wu, Hong-Tan; Wang, Guey Horng; Ho, Bing-Ying; Chen, Yu-Pei

    2018-04-01

    Arctigenin (ATG), a lignin extracted from Arctium lappa (L.), exerts antioxidant and anti-inflammatory effects. We hypothesized that ATG exerts a protective effect on hepatocytes by preventing nonalcoholic fatty liver disease (NAFLD) progression associated with lipid oxidation-associated lipotoxicity and inflammation. We established an in vitro NAFLD cell model by using normal WRL68 hepatocytes to investigate oleic acid (OA) accumulation and the potential bioactive role of ATG. The results revealed that ATG inhibited OA-induced lipid accumulation, lipid peroxidation, and inflammation in WRL68 hepatocytes, as determined using Oil Red O staining, thiobarbituric acid reactive substance assay, and inflammation antibody array assays. Quantitative RT-PCR analysis demonstrated that ATG significantly mitigated the expression of acetylcoenzyme A carboxylase 1 and sterol regulatory element-binding protein-1 and significantly increased the expression of carnitine palmitoyltransferase 1 and peroxisome proliferator-activated receptor alpha. The 40 targets of the Human Inflammation Antibody Array indicated that ATG significantly inhibited the elevation of the U937 lymphocyte chemoattractant, ICAM-1, IL-1β, IL-6, IL-6sR, IL-7, and IL-8. ATG could activate the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) and AMP-activated protein kinase (AMPK) pathways and could increase the phosphorylation levels of Akt and AMPK to mediate cell survival, lipid metabolism, oxidation stress, and inflammation. Thus, we demonstrated that ATG could inhibit NAFLD progression associated with lipid oxidation-associated lipotoxicity and inflammation, and we provided insights into the underlying mechanisms and revealed potential targets to enable a thorough understanding of NAFLD progression. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Genetic Nrf2 Overactivation Inhibits the Deleterious Effects Induced by Hepatocyte-Specific c-met Deletion during the Progression of NASH

    Directory of Open Access Journals (Sweden)

    Pierluigi Ramadori

    2017-01-01

    Full Text Available We have recently shown that hepatocyte-specific c-met deficiency accelerates the progression of nonalcoholic steatohepatitis in experimental murine models resulting in augmented production of reactive oxygen species and accelerated development of fibrosis. The aim of this study focuses on the elucidation of the underlying cellular mechanisms driven by Nrf2 overactivation in hepatocytes lacking c-met receptor characterized by a severe unbalance between pro-oxidant and antioxidant functions. Control mice (c-metfx/fx, single c-met knockouts (c-metΔhepa, and double c-met/Keap1 knockouts (met/Keap1Δhepa were then fed a chow or a methionine-choline-deficient (MCD diet, respectively, for 4 weeks to reproduce the features of nonalcoholic steatohepatitis. Upon MCD feeding, met/Keap1Δhepa mice displayed increased liver mass albeit decreased triglyceride accumulation. The marked increase of oxidative stress observed in c-metΔhepa was restored in the double mutants as assessed by 4-HNE immunostaining and by the expression of genes responsible for the generation of free radicals. Moreover, double knockout mice presented a reduced amount of liver-infiltrating cells and the exacerbation of fibrosis progression observed in c-metΔhepa livers was significantly inhibited in met/Keap1Δhepa. Therefore, genetic activation of the antioxidant transcription factor Nrf2 improves liver damage and repair in hepatocyte-specific c-met-deficient mice mainly through restoring a balance in the cellular redox homeostasis.

  17. Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Woolbright, Benjamin L.; Dorko, Kenneth [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Antoine, Daniel J.; Clarke, Joanna I. [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Gholami, Parviz [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Li, Feng [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson [Department of Surgery, University of Kansas Medical Center, Kansas City, KS (United States); Fan, Fang [Department of Pathology, University of Kansas Medical Center, Kansas City, KS (United States); Jenkins, Rosalind E.; Park, B. Kevin [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Hagenbuch, Bruno [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Olyaee, Mojtaba [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2015-03-15

    Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. - Highlights: • Cholestatic liver injury is due to cytoplasmic bile acid accumulation in hepatocytes. • Primary human hepatocytes are resistant to BA-induced injury

  18. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    OpenAIRE

    Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

    2012-01-01

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentration...

  19. Role of CYP2B in Phenobarbital-Induced Hepatocyte Proliferation in Mice.

    Science.gov (United States)

    Li, Lei; Bao, Xiaochen; Zhang, Qing-Yu; Negishi, Masahiko; Ding, Xinxin

    2017-08-01

    Phenobarbital (PB) promotes liver tumorigenesis in rodents, in part through activation of the constitutive androstane receptor (CAR) and the consequent changes in hepatic gene expression and increases in hepatocyte proliferation. A typical effect of CAR activation by PB is a marked induction of Cyp2b10 expression in the liver; the latter has been suspected to be vital for PB-induced hepatocellular proliferation. This hypothesis was tested here by using a Cyp2a(4/5)bgs -null (null) mouse model in which all Cyp2b genes are deleted. Adult male and female wild-type (WT) and null mice were treated intraperitoneally with PB at 50 mg/kg once daily for 5 successive days and tested on day 6. The liver-to-body weight ratio, an indicator of liver hypertrophy, was increased by 47% in male WT mice, but by only 22% in male Cyp2a(4/5)bgs -null mice, by the PB treatment. The fractions of bromodeoxyuridine-positive hepatocyte nuclei, assessed as a measure of the rate of hepatocyte proliferation, were also significantly lower in PB-treated male null mice compared with PB-treated male WT mice. However, whereas few proliferating hepatocytes were detected in saline-treated mice, many proliferating hepatocytes were still detected in PB-treated male null mice. In contrast, female WT mice were much less sensitive than male WT mice to PB-induced hepatocyte proliferation, and PB-treated female WT and PB-treated female null mice did not show significant difference in rates of hepatocyte proliferation. These results indicate that CYP2B induction plays a significant, but partial, role in PB-induced hepatocyte proliferation in male mice. U.S. Government work not protected by U.S. copyright.

  20. Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes

    OpenAIRE

    Yanhong, Fan; Chenghua, He; Guofang, Liu; Haibin, Zhang

    2008-01-01

    The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-st...

  1. Subtoxic Alterations in Hepatocyte-Derived Exosomes: An Early Step in Drug-Induced Liver Injury?

    Science.gov (United States)

    Holman, Natalie S; Mosedale, Merrie; Wolf, Kristina K; LeCluyse, Edward L; Watkins, Paul B

    2016-06-01

    Drug-induced liver injury (DILI) is a significant clinical and economic problem in the United States, yet the mechanisms that underlie DILI remain poorly understood. Recent evidence suggests that signaling molecules released by stressed hepatocytes can trigger immune responses that may be common across DILI mechanisms. Extracellular vesicles released by hepatocytes, principally hepatocyte-derived exosomes (HDEs), may constitute one such signal. To examine HDE alterations as a function of drug-induced stress, this work utilized prototypical hepatotoxicant acetaminophen (APAP) in male Sprague-Dawley (SD) rats, SD rat hepatocytes, and primary human hepatocytes. HDE were isolated using ExoQuick precipitation reagent and analyzed by quantification of the liver-specific RNAs albumin and microRNA-122 (miR-122). In vivo, significant elevations in circulating exosomal albumin mRNA were observed at subtoxic APAP exposures. Significant increases in exosomal albumin mRNA were also observed in primary rat hepatocytes at subtoxic APAP concentrations. In primary human hepatocytes, APAP elicited increases in both exosomal albumin mRNA and exosomal miR-122 without overt cytotoxicity. However, the number of HDE produced in vitro in response to APAP did not increase with exosomal RNA quantity. We conclude that significant drug-induced alterations in the liver-specific RNA content of HDE occur at subtoxic APAP exposures in vivo and in vitro, and that these changes appear to reflect selective packaging rather than changes in exosome number. The current findings demonstrate that translationally relevant HDE alterations occur in the absence of overt hepatocellular toxicity, and support the hypothesis that HDE released by stressed hepatocytes may mediate early immune responses in DILI. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Calculation of reactivity without Lagrange interpolation

    International Nuclear Information System (INIS)

    Suescun D, D.; Figueroa J, J. H.; Rodriguez R, K. C.; Villada P, J. P.

    2015-09-01

    A new method to solve numerically the inverse equation of punctual kinetics without using Lagrange interpolating polynomial is formulated; this method uses a polynomial approximation with N points based on a process of recurrence for simulating different forms of nuclear power. The results show a reliable accuracy. Furthermore, the method proposed here is suitable for real-time measurements of reactivity, with step sizes of calculations greater that Δt = 0.3 s; due to its precision can be used to implement a digital meter of reactivity in real time. (Author)

  3. Hamming generalized corrector for reactivity calculation

    International Nuclear Information System (INIS)

    Suescun-Diaz, Daniel; Ibarguen-Gonzalez, Maria C.; Figueroa-Jimenez, Jorge H.

    2014-01-01

    This work presents the Hamming method generalized corrector for numerically resolving the differential equation of delayed neutron precursor concentration from the point kinetics equations for reactivity calculation, without using the nuclear power history or the Laplace transform. A study was carried out of several correctors with their respective modifiers with different time step calculations, to offer stability and greater precision. Better results are obtained for some correctors than with other existing methods. Reactivity can be calculated with precision of the order h 5 , where h is the time step. (orig.)

  4. Effects of Cytochrome P 450 Inhibitors on Itraconazole and Fluconazole Induced Cytotoxicity in Hepatocytes

    International Nuclear Information System (INIS)

    Somchit, N.; Ngee, C.S.; Yaakob, A.; Ahmad, Z.; Zakaria, Z.A.

    2009-01-01

    Itraconazole and fluconazole have been reported to induce hepatotoxicity in patients. The present study was designed to investigate the role of cytochrome P450 inhibitors, SKF 525A, and curcumin pretreatment on the cytotoxicity of antifungal drugs fluconazole and itraconazole. For 3 consecutive days, female rats were administered daily SKF 525A or curcumin (5 and 25?mg/kg). Control rats received an equivalent amount of dosed vehicle. The animals were anaesthetised 24 hours after receiving the last dose for liver perfusion. Hepatocytes were then exposed to various concentrations of antifungal drugs. In vitro incubation of hepatocytes with itraconazole revealed significantly lower viability when compared to fluconazole as assessed by lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase activities. The cytotoxicity of itraconazole was enhanced when incubated with hepatocytes pretreated with SKF 525A. SKF 525A had no effects on the cytotoxicity of fluconazole. Curcumin failed to either increase or decrease the cytotoxicity of both antifungal drugs. ATP levels also showed significant decrease in both itraconazole and fluconazole incubated hepatocytes. However, SKF 525A pretreated hepatocytes had significantly lower ATP levels after itraconazole incubations. Collectively, these results confirm the involvement of cytochrome P450 in the cytoprotection in itraconazole induced hepatocyte toxicity. Differences of the effects of SKF 525A on the cytotoxicity induced by itraconazole and fluconazole may be due to the differences on the metabolism of each antifungal drug in vivo.

  5. YAP Inhibition Restores Hepatocyte Differentiation in Advanced HCC, Leading to Tumor Regression

    Directory of Open Access Journals (Sweden)

    Julien Fitamant

    2015-03-01

    Full Text Available Defective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC. Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. YAP functions as a rheostat in maintaining metabolic specialization, differentiation, and quiescence within the hepatocyte compartment. Increased or decreased YAP activity reprograms subsets of hepatocytes to different fates associated with deregulation of the HNF4A, CTNNB1, and E2F transcriptional programs that control hepatocyte quiescence and differentiation. Importantly, treatment with small interfering RNA-lipid nanoparticles (siRNA-LNPs targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model. Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of the positional identity of hepatocytes, supports targeting of YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype that is potentially responsive to this approach.

  6. [The polyploidization characteristics of the hepatocytes of the mouse-like hamster Calomyscus mystax].

    Science.gov (United States)

    Anatskaia, O V; Malikov, V G; Meĭer, M N; Kudriavtsev, B N

    1995-01-01

    A cytophotometric measurement of DNA content in hepatocytes of maturing mouse-like hamsters was made. Cells belonging to ordinary mammalian ploidy classes 2c, 2c x 2, 4c, and 4c x 2 made about 90% of the hepatocyte population. The share of binucleated cells wa high (about 80%), the majority of these cells being 2c X 2 hepatocytes. Binucleated cells with tetraploid and diploid nuclei occur in almost every animal. An average hepatocyte ploidy level in mouse-like hamster is 4.6c. The main peculiarity of parenchymal liver cell populations is that up 5% of hepatocytes contain 3--11 nuclei of different ploidy classes. Multinucleated cells increase in number from 1.5% to 4% within the period from one year (the age of maturation) to two years. Later on their percentage does not change. It is found that in binucleated and multinucleated hepatocytes DNA synthesis can proceed asynchronously. Asynchrony in DNA synthesis elevates as the number of nuclei increases. Among the 2c x 2 and 2c x 3 cells an uneven distribution of 3H-thymidine label can occur, respectively, in 5 and in 50% cases, whereas all the cells with more than 3 nuclei display an uneven an uneven 3H-thymidin label distribution. The formation of multinucleated cells is supposed to be associated with asynchrony in DNA-synthesis in binucleated cells and with the restitution of mitosis.

  7. Hepatocyte transplantation and advancements in alternative cell sources for liver-based regenerative medicine.

    Science.gov (United States)

    Lee, Charlotte A; Sinha, Siddharth; Fitzpatrick, Emer; Dhawan, Anil

    2018-06-01

    Human hepatocyte transplantation has been actively perused as an alternative to liver replacement for acute liver failure and liver-based metabolic defects. Current challenges in this field include a limited cell source, reduced cell viability following cryopreservation and poor engraftment of cells into the recipient liver with consequent limited life span. As a result, alternative stem cell sources such as pluripotent stem cells, fibroblasts, hepatic progenitor cells, amniotic epithelial cells and mesenchymal stem/stromal cells (MSCs) can be used to generate induced hepatocyte like cells (HLC) with each technique exhibiting advantages and disadvantages. HLCs may have comparable function to primary human hepatocytes and could offer patient-specific treatment. However, long-term functionality of transplanted HLCs and the potential oncogenic risks of using stem cells have yet to be established. The immunomodulatory effects of MSCs are promising, and multiple clinical trials are investigating their effect in cirrhosis and acute liver failure. Here, we review the current status of hepatocyte transplantation, alternative cell sources to primary human hepatocytes and their potential in liver regeneration. We also describe recent clinical trials using hepatocytes derived from stem cells and their role in improving the phenotype of several liver diseases.

  8. Design and Development of Virtual Reactivity System for PWR

    International Nuclear Information System (INIS)

    Anwar, M. I.

    2012-01-01

    The reactivity monitoring and investigation is an important mean to ensure the safety operation of a nuclear power plant. But the reactivity of the nuclear reactor usually cannot be directly measured. It should be computed with certain estimation method. In this thesis, an effort has been made using an artificial neural network and highly fluctuating experimental data for predicting the total reactivity of the nuclear reactor based on all components of net reactivity. This virtual reactivity system is designed by taking advantage of neural network's nonlinear mapping capability. Based on analysis of the reactivity contributing factors, several neural network models are built separately for control rod, boron, poisons, fuel Doppler Effect and moderator effect. Extensive simulation and validation tests for PWR show that satisfied results have been obtained with the proposed approach. It presents a new idea to estimate the PWR's reactivity using artificial intelligence. All the design and simulation work is carried out in MATLAB and a real time programming environment is chosen for the computation and prediction of reactivity. (author)

  9. Electrospinning of reactive mesogens

    NARCIS (Netherlands)

    Yao, J.; Picot, O.T.; Hughes-Brittain, N.F.; Bastiaansen, C.W.M.; Peijs, T.

    2016-01-01

    The reinforcement potential of reactive liquid crystals or reactive mesogens (RMs) in electrospun fibers was investigated through the blending of two types of RMs (RM257 and RM82) with two types of thermoplastics; polyamide 6 (PA6) and poly(methyl methacrylate) (PMMA). Polymer/RM blends were

  10. Chronic Ethanol Consumption in Mice Alters Hepatocyte Lipid Droplet Properties

    Science.gov (United States)

    Orlicky, David J.; Roede, James R.; Bales, Elise; Greenwood, Carrie; Greenberg, Andrew; Petersen, Dennis; McManaman, James L.

    2014-01-01

    Background Hepatosteatosis is a common pathological feature of impaired hepatic metabolism following chronic alcohol consumption. Although often benign and reversible, it is widely believed that steatosis is a risk factor for development of advanced liver pathologies, including steatohepatitis and fibrosis. The hepatocyte alterations accompanying the initiation of steatosis are not yet clearly defined. Methods Induction of hepatosteatosis by chronic ethanol consumption was investigated using the Lieber-DeCarli (LD) high fat diet model. Effects were assessed by immunohistochemistry and blood and tissue enzymatic assays. Cell culture models were employed for mechanistic studies. Results Pair feeding mice ethanol (LD-Et) or isocaloric control (LD-Co) diets for 6 weeks progressively increased hepatocyte triglyceride accumulation in morphological, biochemical, and zonally distinct cytoplasmic lipid droplets (CLD). The LD-Et diet induced zone 2-specific triglyceride accumulation in large CLD coated with perilipin, adipophilin (ADPH), and TIP47. In LD-Co- fed mice, CLD were significantly smaller than those in LD-Et-fed mice and lacked perilipin. A direct role of perilipin in formation of large CLD was further suggested by cell culture studies showing that perilipin-coated CLD were significantly larger than those coated with ADPH or TIP47. LD-Co- and LD-Et-fed animals also differed in hepatic metabolic stress responses. In LD-Et but not LD-Co-fed mice, inductions were observed in the following: microsomal ethanol-oxidizing system [cytochrome P-4502E1 (CYP2E1)], hypoxia response pathway (hypoxia-inducible factor 1 alpha, HIF1α), endoplasmic reticulum stress pathway (calreticulin), and synthesis of lipid peroxidation products [4-hydroxynonenal (4-HNE)]. CYP2E1 and HIF1 α immunostaining localized to zone 3 and did not correlate with accumulation of large CLD. In contrast, calreticulin and 4-HNE immunostaining closely correlated with large CLD accumulation. Importantly, 4

  11. Hepatocyte-protective effect of nectandrin B, a nutmeg lignan, against oxidative stress: Role of Nrf2 activation through ERK phosphorylation and AMPK-dependent inhibition of GSK-3β

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jae-Sook; Kim, Eun-Kyung; Choi, Yong-Won [Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Gyeonggi-do 15588 (Korea, Republic of); Oh, Won Keun [College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University (Korea, Republic of); Kim, Young-Mi, E-mail: ymikim12@hanyang.ac.kr [Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Gyeonggi-do 15588 (Korea, Republic of)

    2016-09-15

    Oxidative stress can contribute to the development and progression of liver diseases, such as drug-induced or alcoholic liver injury, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis. Nectandrin B is a bioactive lignan isolated from nutmeg extract. To date, little information is available about its pharmacological activities in the liver. This study investigated the hepatocyte-protective effect of nectandrin B against tert-butylhydroperoxide-induced oxidative injury and the underlying molecular mechanism. The cell viability assay revealed that nectandrin B prevents apoptosis stimulated by tert-butylhydroperoxide in both HepG2 cells and primary mouse hepatocytes. Nectandrin B also attenuated ROS production and restored the depleted glutathione level. Real-time PCR and immunoblot analyses showed that the expression of glutamate-cysteine ligase, an enzyme responsible for the glutathione biosynthesis, was induced by nectandrin B, indicating its indirect antioxidative effect. The NF-E2-related factor-2 (Nrf2) regulates gene expression of an array of antioxidant enzymes in hepatocytes. Nectandrin B stimulated Nrf2 activation as evidenced by its enhanced nuclear accumulation and increased antioxidant response element (ARE)-luciferase activity. Intriguingly, the hepatocyte-protective effect of nectandrin B against oxidative damage was completely abrogated by Nrf2 knockdown using Nrf2 specific siRNA. Nectandrin B promoted ERK activation, but inactivated GSK-3β through the AMPK-mediated inhibitory phosphorylation. The enforced overexpression of dominant-negative mutant of MEK1 or AMPKα, or wild-type GSK-3β inhibited the increase in the NQO1-ARE-luciferase activity stimulated by nectandrin B, suggesting that both ERK and AMPK-GSK-3β signalings are involved in the activation of Nrf2/ARE pathway by nectandrin B. Consistent with this, cytoprotection and restoration of glutathione level by nectandrin B was also blocked by the overexpression of dominant

  12. Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

    International Nuclear Information System (INIS)

    Jia, Rui; Cao, Li-Ping; Du, Jin-Liang; Wang, Jia-Hao; Liu, Ying-Juan; Jeney, Galina; Xu, Pao; Yin, Guo-Jun

    2014-01-01

    Highlights: • We explored the underlying toxicology of CCl 4 at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl 4 activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl 4 )-induced hepatotoxicity in fish was investigated by studying the effects of CCl 4 on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl 4 in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl 4 at 8 mM. The results showed that CCl 4 significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl 4 caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl 4 -induced hepatotoxicity in fish

  13. Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Rui [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Cao, Li-Ping; Du, Jin-Liang [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Wang, Jia-Hao; Liu, Ying-Juan [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Jeney, Galina [National Agricultural Research Center, Research Institute for Fisherie and, Aquaculture, Anna Light 8, Szarvas 5440 (Hungary); Xu, Pao, E-mail: xup@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Yin, Guo-Jun, E-mail: yingj@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China)

    2014-07-01

    Highlights: • We explored the underlying toxicology of CCl{sub 4} at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl{sub 4} activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl{sub 4})-induced hepatotoxicity in fish was investigated by studying the effects of CCl{sub 4} on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl{sub 4} in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl{sub 4} at 8 mM. The results showed that CCl{sub 4} significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl{sub 4} caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl{sub 4}-induced hepatotoxicity in fish.

  14. Effect of Brewing Duration on the Antioxidant and Hepatoprotective Abilities of Tea Phenolic and Alkaloid Compounds in a t-BHP Oxidative Stress-Induced Rat Hepatocyte Model

    Directory of Open Access Journals (Sweden)

    Laura Braud

    2015-08-01

    Full Text Available Tea is an interesting source of antioxidants capable of counteracting the oxidative stress implicated in liver diseases. We investigated the impact of antioxidant molecules provided by a mixture of teas’ leaves (green, oolong, pu-erh after different infusion durations in the prevention of oxidative stress in isolated rat hepatocytes, by comparison with pure epigallocatechin-3-gallate (EGCG, the main representative of tea catechins. Dried aqueous tea extracts (ATE obtained after 5, 15 and 30 min infusion time were characterized for total polyphenols (gallic acid equivalent, catechins, gallic acid and caffeine (HPLC-DAD/ESI-MS contents, and for scavenging ability against 2,2-diphenyl-1-picrylhydrazyl free radical. Hepatoprotection was evaluated through hepatocyte viability tests using tert-butyl hydroperoxide as a stress inducer, (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide, neutral red uptake, real-time cellular impedance and mitochondrial function tests. We showed that a 5-min incubation time is sufficient for an optimal bioaccessibility of tea compounds with the highest antioxidative ability, which decreases for longer durations. A 4-h pretreatment of cells with ATE significantly prevented cell death by regulating reactive oxygen species production and maintaining mitochondrial integrity. Pure EGCG, at doses similar in ATE (5–12 µM, was inefficient, suggesting a plausible synergy of several water-soluble tea compounds to explain the ATE beneficial effects.

  15. Requirements of glycerol and fatty acid for triglyceride synthesis and ketogenesis by hepatocytes from normal and triiodothyronine-treated rats

    International Nuclear Information System (INIS)

    Olubadewo, J.O.; Heimberg, M.

    1985-01-01

    Hepatocytes from T3-treated rats synthesized less triglyceride and more ketone bodies from [1- 14 C]oleate at all concentrations from 0-2 mM, than did hepatocytes from euthyroid animals; addition of 1.0 mM glycerol increased triglyceride synthesis and reduced ketogenesis in hepatocytes from T3-treated rats to the rates observed in euthyroid hepatocytes in the absence of added glycerol. Glycerol did not alter triglyceride synthesis, but reduced ketogenesis genesis by euthyroid hepatocytes. It is probable from these and other data that, in the hyperthyroid rat, glycero-3-P, and not fatty acid, is rate limiting for synthesis of triglyceride, and, secondarily for reducing rates of ketogenesis in the hepatocyte

  16. Somatomedin-C stimulates glycogen synthesis in fetal rat hepatocytes

    International Nuclear Information System (INIS)

    Freemark, M.; D'Ercole, A.J.; Handwerger, S.

    1985-01-01

    The effects of somatomedin-C/insulin-like growth factor I (Sm-C) on glycogen metabolism in cultured hepatocytes from 20-day-old rat fetuses have been examined and compared with the effects of insulin. Sm-C (25-375 ng/ml; 3.25-50 nM) stimulated dose-dependent increases in [ 14 C]glucose incorporation into glycogen (14.4-72.9% and total cell glycogen content (10.6-34.3%. Maximal stimulation of glycogen synthesis by Sm-C occurred at 2-4 h of incubation. Insulin (10 nM to 10 microM) also stimulated [ 14 C]glucose incorporation but its potency was only 1/20th that of Sm-C. The time course of stimulation of glucose incorporation by insulin was identical to that of Sm-C, the dose-response curves of the two hormones were parallel, and the maximal effects of insulin were not enhanced by simultaneous exposure of cells to Sm-C. These findings suggest that Sm-C and insulin stimulate glycogenesis in fetal liver through similar or identical mechanisms. Since the potency of Sm-C was 20 times greater than that of insulin, the glycogenic action of insulin in fetal liver may be mediated through binding to a hepatic receptor which also binds Sm-C. In addition to having mitogenic effects on fetal tissues, Sm-C may have direct anabolic effects on fetal carbohydrate metabolism

  17. Protein phosphorylation in isolated hepatocytes of septic and endotoxemic rats

    International Nuclear Information System (INIS)

    Deaciuc, I.V.; Spitzer, J.A.

    1989-01-01

    The purpose of this study was to investigate possible alterations induced by sepsis and endotoxicosis in the late phase of Ca2+-dependent signaling in rat liver. Hepatocytes isolated from septic or chronically endotoxin (ET)-treated rats were labeled with [32P]H3PO4 and stimulated with various agents. Proteins were resolved by one-dimensional polyacrylamide gel electrophoresis and autoradiographed. Vasopressin (VP)- and phenylephrine (PE)-induced responses were attenuated in both septic and ET-treated rats for cytosolic and membrane proteins compared with their respective controls. Glucagon and 12-O-myristate phorbol-13-acetate (TPA) affected only the phosphorylation of membrane proteins. Glucagon-induced changes in the phosphorylation of membrane proteins were affected by both sepsis and endotoxicosis, whereas TPA-stimulated phosphorylation was lowered only in endotoxicosis. Response to the Ca2+ ionophore A23187 was depressed in septic rats for cytosolic proteins. The phosphorylation of two cytosolic proteins, i.e., 93 and 61 kDa (previously identified as glycogen phosphorylase and pyruvate kinase, respectively), in response to VP, PE, and A23187 was severely impaired by endotoxicosis and sepsis. TPA did not affect the phosphorylation state of these two proteins. The results show that sepsis and endotoxicosis produce perturbations of the phosphorylation step in Ca2+ transmembrane signaling. Such changes can explain alterations of glycogenolysis and gluconeogenesis associated with sepsis and endotoxicosis

  18. Stabilization of glucocorticoid receptors in isolated rat hepatocytes by radioprotectants

    International Nuclear Information System (INIS)

    Karle, J.M.; Ridder, W.E.; Wright, N.; Olmeda, R.; Nielsen, C.J.

    1986-01-01

    Previous work has shown that glucocorticoid receptors in rat liver homogenate can be stabilized by the addition of MoO 4 plus the sulfhydryl-containing compounds dithiothreitol and WR 1065. The latter is the dephosphorylated, principal metabolite of the radioprotectant WR 2721 (or S-2-(3-aminopropylamino)ethanesphosphorothioic acid). The current work results from applying this knowledge to intact rat hepatocytes. Cells were isolated by collagenase perfusion and incubated in supplemented minimum essential medium at 37 0 C with various concentrations of WR 2721, WR 1065, or vehicle. Samples of these cell suspensions were analyzed at various times for steroid binding capacity by incubating homogenates (27,000 x g supernates) with 50 nM 3 H-triamcinolone acetonide in the presence or absence of excess unlabelled dexamethasone. Concentrations of 10 mM WR 2721 provided marked preservation of the binding capacity (>85% of the initial value at 5 hours) compared to control at 60% of the binding capacity. WR 1065 at 10 mM provided no such protection. This is consistent with the observation that WR 1065 does not pass cell membranes. The authors propose that supplying reducing equivalents to intracellular components such as the glucocorticoid receptor may be one mechanism of the radioprotection afforded by WR 2721

  19. Relationship of histochemically detectable altered hepatocyte foci to hepatic tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Peraino, C.; Staffeldt, E.F.; Carnes, B.A.; Ludeman, V.A.; Blomquist, J.A.; Vesselinovitch, S.D.

    1984-01-01

    A new experimental system was used to examine the stages of chemically induced hepatic neoplasia in the rat. The treatment protocol involved the intraperitoneal injection of a single non-necrogenic dose of carcinogen (N-nitrosodiethylamine (NDEA) or benzo(a)pyrene (BP)) into male and female rats within one day after birth, followed by dietary exposure to promoter (0.05% phenobarbital) from weaning. Rats were killed at intervals, and their livers were examined for tumors and for histochemically detectable foci of altered hepatocytes. The data showed that (1) the new treatment protocol was highly efficient in foci and tumor production; (2) growth rates and incidence levels of foci were directly related to hepatocarcinogenic effectiveness (NDEA > BP), whereas both carcinogens had similar effects on foci phenotypic properties; (3) after their formation, foci at a given level of phenotypic complexity did not become progressively more complex; (4) incidence levels of foci were sex-dependent (females > males), but growth rates of foci were the same for both sexes; (5) growth rates and growth capacities (ranges of possible growth rates) of foci were directly related to phenotypic complexity levels of foci; (6) frequencies and phenotypic complexities of foci were inversely related; the reverse was true for tumors, although 10% of the tumors were relatively simple (three markers or fewer); (7) marker frequency distribution patterns were completely different in foci and in tumors.

  20. Anabolic regulation of gluconeogenesis by insulin in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Mohan, C.; Bessman, S.P.

    1985-01-01

    The role of substrate availability in the regulation of gluconeogenesis in isolated rat hepatocytes was studied using [U- 14 C]alanine as a tracer in the presence of different concentrations of L-alanine in the incubation medium. At low alanine concentrations (0.5 mM) insulin decreased the 14 C incorporation into the glucose pool and increased the incorporation of tracer carbons into the protein and lipid pools and into CO 2 . The net radioactivity lost from the glucose pool was only a small percentage of the total increase in the activity of the protein, lipid, CO 2 , or glycogen pools, supporting the notion that the effect of insulin in diminishing gluconeogenesis is secondary to its effects on pathways using pyruvate. At higher concentrations of alanine (2.5, 5.0, and 10.0 mM) in the incubation medium insulin increased the movement of alanine carbons into protein and glucose. These results were further confirmed by using [U- 14 C]lactate. The increases in observed specific activity of glucose following insulin administration would not be possible if insulin acted by affecting the activity of any enzyme directly involved in the formation or utilization of pyruvate, most of which have been proposed as sites of insulin action. Data presented show that insulin inhibits gluconeogenesis by affecting a change in substrate availability

  1. Translation of mitochondrial proteins in digitonin-treated rat hepatocytes

    International Nuclear Information System (INIS)

    Kuzela, S.; Wielburski, A.; Nelson, B.D.

    1981-01-01

    Although it is now clear that up to 13 peptides may be encoded in mammalian mitochondrial DNA there is little agreement concerning the numbers of stable translation products detectable in these mitochondria. Part of this uncertainty is due to the low rates of labeling of mammalian mitochondrial translations products resulting from the relatively slow growth rates of mammalian cells. Indeed, it is often necessary to isolate mammalian mitochondria in order to analyze their translation products, and the isolation procedures could conceivably lead to artifacts from proteolysis or from the early release of nascent peptides. To circumvent this problem, it would be desirable to have available a mammalian system which combines the advantage of high rates of labeling of mitochondrial proteins with rapid preparation times. The authors report the novel use of digitonin-treated rat hepatocytes, which provide such a system. This preparation, which is complete in <10 min, does not carry out cytosolic protein synthesis, but labels mitochondrial translation products at rates much higher than intact cells or isolated, in vitro labeled mitochondria. (Auth.)

  2. Hepatocyte cotransport of taurocholate and bilirubin glucuronides: Role of microtubules

    International Nuclear Information System (INIS)

    Crawford, J.M.; Gollan, J.L.

    1988-01-01

    Modulation of bile pigment excretion by bile salts has been attributed to modification of canalicular membrane transport or a physical interaction in bile. Based on the observation that a microtubule-dependent pathway is involved in the hepatocellular transport of bile salts, the authors investigated the possibility that bilirubin glucuronides are associated with bile salts during intracellular transport. Experiments were conducted in intact rats (basal) or after overnight biliary diversion and intravenous reinfusion of taurocholate (depleted/reinfused). All rats were pretreated with intravenous low-dose colchicine or its inactive isomer lumicolchicine. Biliary excretion of radiolabeled bilirubin glucuronides derived from tracer [ 14 C]bilirubin-[ 3 H]bilirubin monoglucuronide (coinjected iv) was unchanged in basal rats but was consistently delayed in depleted/reinfused rats. This was accompanied by a significant shift toward bilirubin diglucuronide formation from both substrates. In basal Gunn rats, with deficient bilirubin glucuronidation, biliary excretion of intravenous [ 14 C]bilirubin monoglucuronide-[ 3 H]bilirubin diglucuronide was unaffected by colchicine but was retarded in depleted/reinfused Gunn rats. Colchicine had no effect on the rate of bilirubin glucuronidation in vitro in rat liver microsomes. They conclude that a portion of the bilirubin glucuronides generated endogenously in hepatocytes or taken up directly from plasma may be cotransported with bile salts to the bile canalicular membrane via a microtubule-dependent mechanism

  3. [Cadmium citotoxicity in mice hepatocytes and implications on tropical environments].

    Science.gov (United States)

    Marcano, Letty; Faría, Clarisa de R; Carruyo, Ingrid; Montiel, Xiomara

    2006-06-01

    We analyzed phenotypic, structural and ultrastructural alterations induced by Cd+2 in hepatocytes extracted from Swiss Albino mice. Cadmium was given orally in watery solution of CdCl2 during 100 days at concentrations of 50 ppm, 100 ppm and 150 ppm. In controls, distilled water alone was used. The samples were processed with the paraffin inclusion and hematoxilin-eosin coloration techniques for light microscopy. For transmission electron microscopy we used the conventional technique. We found phenotypic (size and weight differences) and physiologic changes (muscular weakness, unrest); at the structural level we noticed loss of trabecular disposition and of lobulillar architecture, lymphocyte agglomeration, vacuolization, dilatation of sinusoid and central vein, among others. The ultrastructural study evidenced alterations coincident with those seen with light microscopy, which were accentuated with the increase of metal concentration: nucleolus with a high number of fibrillar centers (50 ppm); voluminous lipidic drops in the cytoplasm, loose endoplasmic rough reticulum, citoplasmatic vacuolization, altered lisosomes and peroxisomes (100 ppm); contracted nuclei with condensed cromatine, dilatation of intracellular space and mitochondria, and loss of fibrillar areas (150 ppm). Cadmium produces a toxic effect in the hepatic cells; the effect is more severe at higher concentration, leading to cellular necrosis.

  4. Hepatocyte growth factor in renal failure: promise and reality.

    Science.gov (United States)

    Vargas, G A; Hoeflich, A; Jehle, P M

    2000-04-01

    Can science discover some secrets of Greek mythology? In the case of Prometheus, we can now suppose that his amazing hepatic regeneration was caused by a peptide growth factor called hepatocyte growth factor (HGF). Increasing evidence indicates that HGF acts as a multifunctional cytokine on different cell types. This review addresses the molecular mechanisms that are responsible for the pleiotropic effects of HGF. HGF binds with high affinity to its specific tyrosine kinase receptor c-met, thereby stimulating not only cell proliferation and differentiation, but also cell migration and tumorigenesis. The three fundamental principles of medicine-prevention, diagnosis, and therapy-may be benefited by the rational use of HGF. In renal tubular cells, HGF induces mitogenic and morphogenetic responses. In animal models of toxic or ischemic acute renal failure, HGF acts in a renotropic and nephroprotective manner. HGF expression is rapidly up-regulated in the remnant kidney of nephrectomized rats, inducing compensatory growth. In a mouse model of chronic renal disease, HGF inhibits the progression of tubulointerstitial fibrosis and kidney dysfunction. Increased HGF mRNA transcripts were detected in mesenchymal and tubular epithelial cells of rejecting kidney. In transplanted patients, elevated HGF levels may indicate renal rejection. When HGF is considered as a therapeutic agent in human medicine, for example, to stimulate kidney regeneration after acute injury, strategies need to be developed to stimulate cell regeneration and differentiation without an induction of tumorigenesis.

  5. Acylation and metabolism of (n-6) fatty acids in hepatocytes

    International Nuclear Information System (INIS)

    Voss, A.C.; Sprecher, H.

    1986-01-01

    Isolated hepatocytes (5 x 10 6 in 2ml) from chow fed rats were incubated from 20 to 60 min. with increasing concentrations of [1- 14 C] labeled 18:2 (n-6), 18:3 (n-6) or 20:3 (n-6) to define optimum conditions for measuring acylation and metabolism to other (n-6) acids with subsequent incorporation into lipids. The triglycerides (TG) and phospholipids (PL) contained 157 and 80 nmols of 18:2 (n-6) and 6.0 and 6.1 nmols of other (n-6) acids, respectively, when cells were incubated with 0.3mM [1- 14 C] 18:2 (n-6) for 40 min. When cells were incubated with 0.3mM [1- 14 C] 18:2 (n-6) plus 0.15 to 0.45mM 18:3 (n-6) or 20:3 (n-6), the metabolism of 18:2 (n-6) to other (n-6) acids was inhibited but not totally abolished. These results may suggest that (n-6) acid made from linoleate do not totally equilibrate with exogenous 18:3 (n-6) or 20:3

  6. The anti-inflammatory effects of flavanol-rich lychee fruit extract in rat hepatocytes.

    Directory of Open Access Journals (Sweden)

    Ryota Yamanishi

    Full Text Available Flavanol (flavan-3-ol-rich lychee fruit extract (FRLFE is a mixture of oligomerized polyphenols primarily derived from lychee fruit and is rich in flavanol monomers, dimers, and trimers. Supplementation with this functional food has been shown to suppress inflammation and tissue damage caused by high-intensity exercise training. However, it is unclear whether FRLFE has in vitro anti-inflammatory effects, such as suppressing the production of the proinflammatory cytokine tumor necrosis factor α (TNF-α and the proinflammatory mediator nitric oxide (NO, which is synthesized by inducible nitric oxide synthase (iNOS. Here, we analyzed the effects of FRLFE and its constituents on the expression of inflammatory genes in interleukin 1β (IL-1β-treated rat hepatocytes. FRLFE decreased the mRNA and protein expression of the iNOS gene, leading to the suppression of IL-1β-induced NO production. FRLFE also decreased the levels of the iNOS antisense transcript, which stabilizes iNOS mRNA. By contrast, unprocessed lychee fruit extract, which is rich in flavanol polymers, and flavanol monomers had little effect on NO production. When a construct harboring the iNOS promoter fused to the firefly luciferase gene was used, FRLFE decreased the luciferase activity in the presence of IL-1β, suggesting that FRLFE suppresses the promoter activity of the iNOS gene at the transcriptional level. Electrophoretic mobility shift assays indicated that FRLFE reduced the nuclear transport of a key regulator, nuclear factor κB (NF-κB. Furthermore, FRLFE inhibited the phosphorylation of NF-κB inhibitor α (IκB-α. FRLFE also reduced the mRNA levels of NF-κB target genes encoding cytokines and chemokines, such as TNF-α. Therefore, FRLFE inhibited NF-κB activation and nuclear translocation to suppress the expression of these inflammatory genes. Our results suggest that flavanols may be responsible for the anti-inflammatory and hepatoprotective effects of FRLFE and may be

  7. Finite differences with exponential filtering in the calculation of reactivity

    International Nuclear Information System (INIS)

    Suescun Diaz, Daniel; Senra Martinez, Aquilino

    2010-01-01

    A formulation for the calculation of reactivity using a recursive process is presented in this paper, as well as the treatment to reduce noise intensity that is found in the nuclear power signal. Using the history of nuclear power considered as the memory of such power and the filter exponentially adjusted with the least squares method, it is possible to reduce the nuclear power fluctuations without causing attenuation for the calculation of reactivity and with a smaller delay than that for low-pass filter of first order delay filter. (orig.)

  8. Finite differences with exponential filtering in the calculation of reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Suescun Diaz, Daniel; Senra Martinez, Aquilino [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). COPPE - Programa de Engenharia Nuclear

    2010-08-15

    A formulation for the calculation of reactivity using a recursive process is presented in this paper, as well as the treatment to reduce noise intensity that is found in the nuclear power signal. Using the history of nuclear power considered as the memory of such power and the filter exponentially adjusted with the least squares method, it is possible to reduce the nuclear power fluctuations without causing attenuation for the calculation of reactivity and with a smaller delay than that for low-pass filter of first order delay filter. (orig.)

  9. Technology Roadmaps: Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This nuclear energy roadmap has been prepared jointly by the IEA and the OECD Nuclear Energy Agency (NEA). Unlike most other low-carbon energy sources, nuclear energy is a mature technology that has been in use for more than 50 years. The latest designs for nuclear power plants build on this experience to offer enhanced safety and performance, and are ready for wider deployment over the next few years. Several countries are reactivating dormant nuclear programmes, while others are considering nuclear for the first time. China in particular is already embarking on a rapid nuclear expansion. In the longer term, there is great potential for new developments in nuclear energy technology to enhance nuclear's role in a sustainable energy future.

  10. Effect of remifentanil on mitochondrial oxygen consumption of cultured human hepatocytes.

    Directory of Open Access Journals (Sweden)

    Siamak Djafarzadeh

    Full Text Available During sepsis, liver dysfunction is common, and failure of mitochondria to effectively couple oxygen consumption with energy production has been described. In addition to sepsis, pharmacological agents used to treat septic patients may contribute to mitochondrial dysfunction. This study addressed the hypothesis that remifentanil interacts with hepatic mitochondrial oxygen consumption. The human hepatoma cell line HepG2 and their isolated mitochondria were exposed to remifentanil, with or without further exposure to tumor necrosis factor-α (TNF-α. Mitochondrial oxygen consumption was measured by high-resolution respirometry, Caspase-3 protein levels by Western blotting, and cytokine levels by ELISA. Inhibitory κBα (IκBα phosphorylation, measurement of the cellular ATP content and mitochondrial membrane potential in intact cells were analysed using commercial ELISA kits. Maximal cellular respiration increased after one hour of incubation with remifentanil, and phosphorylation of IκBα occurred, denoting stimulation of nuclear factor κB (NF-κB. The effect on cellular respiration was not present at 2, 4, 8 or 16 hours of incubation. Remifentanil increased the isolated mitochondrial respiratory control ratio of complex-I-dependent respiration without interfering with maximal respiration. Preincubation with the opioid receptor antagonist naloxone prevented a remifentanil-induced increase in cellular respiration. Remifentanil at 10× higher concentrations than therapeutic reduced mitochondrial membrane potential and ATP content without uncoupling oxygen consumption and basal respiration levels. TNF-α exposure reduced respiration of complex-I, -II and -IV, an effect which was prevented by prior remifentanil incubation. Furthermore, prior remifentanil incubation prevented TNF-α-induced IL-6 release of HepG2 cells, and attenuated fragmentation of pro-caspase-3 into cleaved active caspase 3 (an early marker of apoptosis. Our data suggest that

  11. Genome-wide binding and transcriptome analysis of human farnesoid X receptor in primary human hepatocytes.

    Directory of Open Access Journals (Sweden)

    Le Zhan

    Full Text Available Farnesoid X receptor (FXR, NR1H4 is a ligand-activated transcription factor, belonging to the nuclear receptor superfamily. FXR is highly expressed in the liver and is essential in regulating bile acid homeostasis. FXR deficiency is implicated in numerous liver diseases and mice with modulation of FXR have been used as animal models to study liver physiology and pathology. We have reported genome-wide binding of FXR in mice by chromatin immunoprecipitation - deep sequencing (ChIP-seq, with results indicating that FXR may be involved in regulating diverse pathways in liver. However, limited information exists for the functions of human FXR and the suitability of using murine models to study human FXR functions.In the current study, we performed ChIP-seq in primary human hepatocytes (PHHs treated with a synthetic FXR agonist, GW4064 or DMSO control. In parallel, RNA deep sequencing (RNA-seq and RNA microarray were performed for GW4064 or control treated PHHs and wild type mouse livers, respectively.ChIP-seq showed similar profiles of genome-wide FXR binding in humans and mice in terms of motif analysis and pathway prediction. However, RNA-seq and microarray showed more different transcriptome profiles between PHHs and mouse livers upon GW4064 treatment.In summary, we have established genome-wide human FXR binding and transcriptome profiles. These results will aid in determining the human FXR functions, as well as judging to what level the mouse models could be used to study human FXR functions.

  12. Modulation of hepatocyte growth factor gene expression by estrogen in mouse ovary.

    Science.gov (United States)

    Liu, Y; Lin, L; Zarnegar, R

    1994-09-01

    Hepatocyte growth factor (HGF) is expressed in a variety of tissues and cell types under normal conditions and in response to various stimuli such as tissue injury. In the present study, we demonstrate that the transcription of the HGF gene is stimulated by estrogen in mouse ovary. A single injection of 17 beta-estradiol results in a dramatic and transient elevation of the levels of mouse HGF mRNA. Sequence analysis has found that two putative estrogen responsive elements (ERE) reside at -872 in the 5'-flanking region and at +511 in the first intron, respectively, of the mouse HGF gene. To test whether these ERE elements are responsible for estrogen induction of HGF gene expression, chimeric plasmids containing variable regions of the 5'-flanking sequence of HGF gene and the coding region for chloramphenicol acetyltransferase (CAT) gene were transiently transfected into both human endometrial carcinoma RL 95-2 cells and mouse fibroblast NIH 3T3 cells to assess hormone responsiveness. Transfection results indicate that the ERE elements of the mouse HGF gene can confer estrogen action to either homologous or heterologous promoters. Nuclear protein extracts either from RL95-2 cells transfected with the estrogen receptor expression vector or from mouse liver bound in vitro to ERE elements specifically, as shown by band shift assay. Therefore, our results demonstrate that the HGF gene is transcriptionally regulated by estrogen in mouse ovary; and such regulation is mediated via a direct interaction of the estrogen receptor complex with cis-acting ERE elements identified in the mouse HGF gene.

  13. Effect of hepatocyte growth factor on radiation response of HeLa, V79, CHO and primary cultured parenchymal hepatocyte in vitro

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Inoue, Takehiro; Nose, Takayuki; Murayama, Shigeyuki; Teshima, Teruki; Ozeki, Syuji; Koizumi, Masahiko; Inoue, Toshihiko.

    1996-01-01

    Hepatocyte growth factor (HGF) is a multipotent cytokine enhancing regeneration of injured organs as liver, kidney and lung after injury. HGF enhances proliferation of various type of cells, inhibits proliferation of carcinoma cells, enhances motility of epithelial cells. We examined three cell lines (CHO, HeLa, V79) and primary cultured normal rat parenchymal hepatocytes to determine the effect of HGF on radiation response. HGF diminished survival of CHO and V79 cells determined by colony formation assay, whereas no significant change of survival was found in HeLa cells. No synergistic changes of survival were found when these three cell lines were irradiated with the addition of HGF. Thus, HGF did not enhance the radiation effect. We also analyzed the impact of irradiation with HGF on primary cultured normal rat parenchymal hepatocytes. At first, the release of glutamic-oxaloacetic amino-transaminase (GOT) in the supernatant was estimated. Irradiation (40 Gy) with or without HGF did not change GOT release in acute phase by 4 days after irradiation compared with the unirradiated control. Second, the DNA synthesis of rat parenchymal hepatocytes was analyzed using radioactive iodine-labeled deoxyuridine incorporation. HGF counteracted the suppression of DNA synthesis induced by irradiation. Thus, HGF may act as a mitogen even for irradiation-damaged normal cells. (author)

  14. Control rod drive of nuclear reactor

    International Nuclear Information System (INIS)

    Zhuchkov, I.I.; Gorjunov, V.S.; Zaitsev, B.I.

    1980-01-01

    This invention relates to nuclear reactors and, more particularly, to a drive of a control rod of a nuclear reactor and allows power control, excess reactivity compensation, and emergency shut-down of a reactor. (author)

  15. Hepatocyte polarization is essential for the productive entry of the hepatitis B virus.

    Science.gov (United States)

    Schulze, Andreas; Mills, Kerry; Weiss, Thomas S; Urban, Stephan

    2012-02-01

    Human hepatitis B virus (HBV) is characterized by a high species specificity and a distinct liver tropism. Within the liver, HBV replication occurs in differentiated and polarized hepatocytes. Accordingly, the in vitro HBV infection of primary human hepatocytes (PHHs) and the human hepatoma cell line, HepaRG, is restricted to differentiated, hepatocyte-like cells. Though preparations of PHH contain up to 100% hepatic cells, cultures of differentiated HepaRG cells are a mixture of hepatocyte-like and biliary-like epithelial cells. We used PHH and HepaRG cells and compared the influence of virus inoculation dose, cell differentiation, and polarization on productive HBV infection. At multiplicities of genome equivalents (mge) >8,000, almost 100% of PHHs could be infected. In contrast, only a subset of HepaRG cells stained positive for HBcAg at comparable or even higher mge. Infection predominantly occurred at the edges of islands of hepatocyte-like HepaRG cells. This indicates a limited accessibility of the HBV receptor, possibly as a result of its polar sorting. Multidrug resistance protein 2 (MRP2), a marker selectively transported to the apical (i.e., canalicular) cell membrane, revealed two polarization phenotypes of HepaRG cells. HBV infection within the islands of hepatocyte-like HepaRG cells preferentially occurred in cells that resemble PHH, exhibiting canalicular structures. However, disruption of cell-cell junctions allowed the additional infection of cells that do not display a PHH-like polarization. HBV enters hepatocytes via the basolateral membrane. This model, at least partially, explains the difference of PHH and HepaRG cells in infection efficacy, provides insights into natural HBV infection, and establishes a basis for optimization of the HepaRG infection system. Copyright © 2011 American Association for the Study of Liver Diseases.

  16. β-Adrenergic induction of lipolysis in hepatocytes is inhibited by ethanol exposure.

    Science.gov (United States)

    Schott, Micah B; Rasineni, Karuna; Weller, Shaun G; Schulze, Ryan J; Sletten, Arthur C; Casey, Carol A; McNiven, Mark A

    2017-07-14

    In liver steatosis ( i.e. fatty liver), hepatocytes accumulate many large neutral lipid storage organelles known as lipid droplets (LDs). LDs are important in the maintenance of energy homeostasis, but the signaling mechanisms that stimulate LD metabolism in hepatocytes are poorly defined. In adipocytes, catecholamines target the β-adrenergic (β-AR)/cAMP pathway to activate cytosolic lipases and induce their recruitment to the LD surface. Therefore, the goal of this study was to determine whether hepatocytes, like adipocytes, also undergo cAMP-mediated lipolysis in response to β-AR stimulation. Using primary rat hepatocytes and human hepatoma cells, we found that treatment with the β-AR agent isoproterenol caused substantial LD loss via activation of cytosolic lipases adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). β-Adrenergic stimulation rapidly activated PKA, which led to the phosphorylation of ATGL and HSL and their recruitment to the LD surface. To test whether this β-AR-dependent lipolysis pathway was altered in a model of alcoholic fatty liver, primary hepatocytes from rats fed a 6-week EtOH-containing Lieber-DeCarli diet were treated with cAMP agonists. Compared with controls, EtOH-exposed hepatocytes showed a drastic inhibition in β-AR/cAMP-induced LD breakdown and the phosphorylation of PKA substrates, including HSL. This observation was supported in VA-13 cells, an EtOH-metabolizing human hepatoma cell line, which displayed marked defects in both PKA activation and isoproterenol-induced ATGL translocation to the LD periphery. In summary, these findings suggest that β-AR stimulation mobilizes cytosolic lipases for LD breakdown in hepatocytes, and perturbation of this pathway could be a major consequence of chronic EtOH insult leading to fatty liver.

  17. Lipopolysaccharide stimulates p62-dependent autophagy-like aggregate clearance in hepatocytes.

    Science.gov (United States)

    Chen, Christine; Deng, Meihong; Sun, Qian; Loughran, Patricia; Billiar, Timothy R; Scott, Melanie J

    2014-01-01

    Impairment of autophagy has been associated with liver injury. TLR4-stimulation by LPS upregulates autophagy in hepatocytes, although the signaling pathways involved remain elusive. The objective of this study was to determine the signaling pathway leading to LPS-stimulated autophagy in hepatocytes. Cell lysates from livers of wild type (WT; C57BL/6) mice given LPS (5 mg/kg-IP) and hepatocytes from WT, TLR4ko, and MyD88ko mice treated with LPS (100 ng/mL) up to 24 h were collected. LC3II, p62/SQSTM1, Nrf2, and beclin1 levels were determined by immunoblot, immunofluorescence, and qPCR. Autophagy-like activation was measured by GFP-LC3-puncta formation and LC3II-expression. Beclin1, Nrf2, p62, MyD88, and TIRAP were knocked-down using siRNA. LC3II-expression increased in both liver and hepatocytes after LPS and was dependent on TLR4. Beclin1 expression did not increase after LPS in hepatocytes and beclin1-knockdown did not affect LC3II levels. In hepatocytes given LPS, expression of p62 increased and p62 colocalized with LC3. p62-knockdown prevented LC3II puncta formation. LPS-induced LC3II/p62-puncta also required MyD88/TIRAP signaling and localization of both Nrf2 and NF κ B transcription factors to the nucleus to upregulate p62-expression. Therefore, TLR4-activation by LPS in hepatocytes induces a p62-mediated, not beclin1-mediated, autophagy-like clearance pathway that is hepatoprotective by clearing aggregate-prone or misfolded proteins from the cytosol and preserving energy homeostasis under stress.

  18. DISTINCT FUNCTIONS OF JNK AND C-JUN IN OXIDANT-INDUCED HEPATOCYTE DEATH

    Science.gov (United States)

    Amir, Muhammad; Liu, Kun; Zhao, Enpeng; Czaja, Mark J.

    2013-01-01

    Overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling is a central mechanism of hepatocyte injury and death including that from oxidative stress. However, the functions of JNK and c-Jun are still unclear, and this pathway also inhibits hepatocyte death. Previous studies of menadione-induced oxidant stress demonstrated that toxicity resulted from sustained JNK/c-Jun activation as death was blocked by the c-Jun dominant negative TAM67. To further delineate the function of JNK/c-Jun signaling in hepatocyte injury from oxidant stress, the effects of direct JNK inhibition on menadione-induced death were examined. In contrast to the inhibitory effect of TAM67, pharmacological JNK inhibition by SP600125 sensitized the rat hepatocyte cell line RALA255-10G to death from menadione. SP600125 similarly sensitized mouse primary hepatocytes to menadione toxicity. Death from SP600125/menadione was c-J