WorldWideScience

Sample records for mouse liver microsomes

  1. Metabolism of ginger component [6]-shogaol in liver microsomes from mouse, rat, dog, monkey, and human.

    Science.gov (United States)

    Chen, Huadong; Soroka, Dominique; Zhu, Yingdong; Sang, Shengmin

    2013-05-01

    There are limited data on the metabolism of [6]-shogaol (6S), a major bioactive component of ginger. This study demonstrates metabolism of 6S in liver microsomes from mouse, rat, dog, monkey, and human. The in vitro metabolism of 6S was compared among five species using liver microsomes from mouse, rat, dog, monkey, and human. Following incubations with 6S, three major reductive metabolites 1-(4'-hydroxy-3'-methoxyphenyl)-4-decen-3-ol (M6), 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-ol (M9), and 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-one (M11), as well as two new oxidative metabolites (1E,4E)-1-(4'-hydroxy-3'-methoxyphenyl)-deca-1,4-dien-3-one (M14) and (E)-1-(4'-hydroxy-3'-methoxyphenyl)-dec-1-en-3-one (M15) were found in all species. The kinetic parameters of M6 in liver microsomes from each respective species were quantified using Michaelis-Menten theory. A broad CYP-450 inhibitor, 1-aminobenzotriazole, precluded the formation of oxidative metabolites, M14 and M15, and 18β-glycyrrhetinic acid, an aldo-keto reductase inhibitor, eradicated the formation of the reductive metabolites M6, M9, and M11 in all species. Metabolites M14 and M15 were tested for cancer cell growth inhibition and induction of apoptosis and both showed substantial activity, with M14 displaying greater potency than 6S. We conclude that 6S is metabolized extensively in mammalian species mouse, rat, dog, monkey, and human, and that there are significant interspecies differences to consider when planning preclinical trials toward 6S chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. [Immunosuppressant effect of cyclophosphamide activated in vitro by liver microsomes from different strains of mice].

    Science.gov (United States)

    Telegin, L Iu; Zhirnov, G F; Mazurov, A V; Pevnitskiĭ, L A

    1981-07-01

    The paper is concerned with activation of cyclophosphamide by mouse liver microsomes in vitro. Liver microsomes from BALB/c mice metabolize cyclophosphamide more effectively as compared with those from DBA/2 mice, which manifested by a more intense output of products having alkylating or immunodepressant properties. This seems likely to be a consequence of the increased P-450 cytochrome content in liver microsomes from BALB/c mice, as well as of its structural characteristics in the mouse. The relationship between the immunodepressant effect of cyclophosphamide in vivo and in vitro in mice of varied genotypes is discussed.

  3. The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Feng Li

    2018-05-01

    Full Text Available Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM using metabolomic approaches. In human liver microsomes (HLM, we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.

  4. High affinity binding of [3H]cocaine to rat liver microsomes

    International Nuclear Information System (INIS)

    El-Maghrabi, E.A.; Calligaro, D.O.; Eldefrawi, M.E.

    1988-01-01

    ] 3 H]cocaine bound reversible, with high affinity and stereospecificity to rat liver microsomes. Little binding was detected in the lysosomal, mitochondrial and nuclear fractions. The binding kinetics were slow and the kinetically calculated K/sub D/ was 2 nM. Induction of mixed function oxidases by phenobarbital did not produce significant change in [ 3 H]cocaine binding. On the other hand, chronic administration of cocaine reduced [ 3 H]cocaine binding drastically. Neither treatment affected the affinity of the liver binding protein for cocaine. Microsomes from mouse and human livers had less cocaine-binding protein and lower affinity for cocaine than those from rat liver. Binding of [ 3 H]cocaine to rat liver microsomes was insensitive to monovalent cations and > 10 fold less sensitive to biogenic amines than the cocaine receptor in rat striatum. However, the liver protein had higher affinity for cocaine and metabolites except for norcocaine. Amine uptake inhibitors displaced [ 3 H]cocaine binding to liver with a different rank order of potency than their displacement of [ 3 H]cocaine binding to striatum. This high affinity [ 3 H]cocaine binding protein in liver is not likely to be monooxygenase, but may have a role in cocaine-induced hepatotoxicity

  5. Biotransformation of a novel antimitotic agent, I-387, by mouse, rat, dog, monkey, and human liver microsomes and in vivo pharmacokinetics in mice.

    Science.gov (United States)

    Ahn, Sunjoo; Kearbey, Jeffrey D; Li, Chien-Ming; Duke, Charles B; Miller, Duane D; Dalton, James T

    2011-04-01

    3-(1H-Indol-2-yl)phenyl)(3,4,5-trimethoxyphenyl)methanone (I-387) is a novel indole compound with antitubulin action and potent antitumor activity in various preclinical models. I-387 avoids drug resistance mediated by P-glycoprotein and showed less neurotoxicity than vinca alkaloids during in vivo studies. We examined the pharmacokinetics and metabolism of I-387 in mice as a component of our preclinical development of this compound and continued interest in structure-activity relationships for antitubulin agents. After a 1 mg/kg intravenous dose, noncompartmental pharmacokinetic analysis in plasma showed that clearance (CL), volume of distribution at steady state (Vd(ss)), and terminal half-life (t(1/2)) of I-387 were 27 ml per min/kg, 5.3 l/kg, and 7 h, respectively. In the in vitro metabolic stability study, half-lives of I-387 were between 10 and 54 min by mouse, rat, dog, monkey, and human liver microsomes in the presence of NADPH, demonstrating interspecies variability. I-387 was most stable in rat liver microsomes and degraded quickly in monkey liver microsomes. Liquid chromatography-tandem mass spectrometry was used to identify phase I metabolites. Hydroxylation, reduction of a ketone group, and O-demethylation were the major metabolites formed by the liver microsomes of the five species. The carbonyl group of I-387 was reduced and identified as the most labile site in human liver microsomes. The results of these drug metabolism and pharmacokinetic studies provide the foundation for future structural modification of this pharmacophore to improve stability of drugs with potent anticancer effects in cancer patients.

  6. In vitro metabolism of [14C]-toluene by human and rat liver microsomes and liver slices

    International Nuclear Information System (INIS)

    Chapman, D.E.; Moore, T.J.; Michener, S.R.; Powis, G.

    1990-01-01

    Toluene metabolites produced by liver microsomes from six human donors included benzylalcohol (Balc), benzaldehyde (Bald) and benzoic acid (Bacid). Microsomes from only one human donor metabolized toluene to p-cresol and o-cresol. Human liver microsomes also metabolized Balc to Bald. Balc metabolism required NADPH, was inhibited by carbon monoxide, and was decreased at a buffer pH of 10. Balc metabolism was not inhibited by ADP-ribose or sodium azide. These results suggest that cytochrome P450 is responsible for the in vitro metabolism of Balc by human liver microsomes. Toluene metabolites formed by human liver slices and released into the incubation media included hippuric acid, and Bacid. Cresols or cresol-conjugates were not detected in liver slice incubation media from any human donor. Toluene metabolism by human liver was compared to metabolism by comparable liver preparations from male Fischer F344 rats. Rates of toluene metabolism by human liver microsomes and liver slices were 9-fold and 1.3-fold greater than for rat liver, respectively. Covalent binding of toluene to human liver microsomes and liver slices was 21-fold and 4-fold greater than for comparable rat liver preparations. Covalent binding of toluene to human microsomes required NADPH, was significantly decreased by coincubation with 4 mM cysteine or 4 mM glutathione, and radioactivity associated with microsomes was decreased by subsequent digestion of microsomes with protease. These results suggest that toluene metabolism and covalent binding of toluene are underestimated if the male Fischer 344 rat is used as a model for human toluene metabolism

  7. Activation and detoxification metabolism of urban air pollutants 2-nitrobenzanthrone and carcinogenic 3-nitrobenzanthrone by rat and mouse hepatic microsomes.

    Science.gov (United States)

    Stiborova, Marie; Cechova, Tereza; Borek-Dohalska, Lucie; Moserova, Michaela; Frei, Eva; Schmeiser, Heinz H; Paca, Jan; Arlt, Volker M

    2012-01-01

    2-Nitrobenzanthrone (2-NBA) has recently been detected in ambient air particulate matter. Its isomer 3-nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust. Understanding which enzymes are involved in metabolism of these toxicants is important in the assessment of individual susceptibility. Here, metabolism of 2-NBA and 3-NBA by rat and mouse hepatic microsomes containing cytochromes P450 (CYPs), their reductase (NADPH:CYP reductase), and NADH:cytochrome b5 reductase was investigated under anaerobic and aerobic conditions. In addition, using the same microsomal systems, 2-NBA and 3-NBA were evaluated to be enzymatically activated under anaerobic conditions to species generating 2-NBA- and 3-NBA-derived DNA adducts. High performance liquid chromatography (HPLC) with ultraviolet (UV) detection was employed for the separation and characterization of 2-NBA and 3-NBA metabolites formed by hepatic microsomes of rats and mice under the anaerobic and aerobic conditions. Microsomal systems isolated from the liver of the control (untreated) rats and rats pretreated with Sudan I, β-naphthoflavone (β-NF), phenobarbital (PB), ethanol and pregnenolon 16α-carbonitrile (PCN), the inducers of cytochromes P450 (CYP) 1A1, 1A1/2, 2B, 2E1 and 3A, respectively, were used in this study. Microsomes of mouse models, a control mouse line (wild-type, WT) and Hepatic Cytochrome P450 Reductase Null (HRN) mice with deleted gene of NADPH:CYP reductase in the liver, thus absenting this enzyme in their livers, were also employed. To detect and quantify the 2-NBA- and 3-NBA-derived DNA adducts, the 32P postlabeling technique was used. Both reductive metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), found to be formed predominantly under the anaerobic conditions, and two 3-NBA oxidative metabolites, whose structures have not yet been investigated, were formed by several microsomal systems used in the study. Whereas a 3-NBA reductive metabolite

  8. An integrated study for the utilization of anthraquinone compounds extract “Heshouwu” In vivo and their comparative metabolism in liver microsomes using UPLC-ESI-Q-TOF/MSn

    Directory of Open Access Journals (Sweden)

    Sha Chen

    2018-01-01

    Full Text Available Objective: Anthraquinone (AQ, a major bioactive component of the traditional Chinese medicine HeShouWu, has widespread applications in industry and medicine. The objective of the current study is to explore the differences in the bioavailability of anthraquinones in vivo and the metabolism in liver microsomes. Materials and Methods: In vivo, we used a reliable UPLC-ESI-QqQ-MS/MS method to measure seven AQ compounds in the jugular vein plasma of rats following oral administration of HeShouWu. Furthermore, in order to quantify the bioavailability of AQs in vivo and to further understand the metabolism of these compounds, we compared the in vitro metabolism of AQ in different species with respect to metabolic profiles, the enzymes involved, and catalytic efficiency using liver microsomes from human (HLM, mouse (MLM, rat (RLM, and beagle dog (DLM. Results: We identified two metabolic pathways, including the hydroxylation and glucuronidation of AQ, in the liver microsomes of humans and other species using UPLC-ESI-Q-TOF. We found that substitutions on the AQ ring were crucial to the activity and regioselectivity of its hydroxylation. In general, hydroxylation activity decreased greatly with β-COOH (rhein and enhanced dramatically with β-OH (emodin. We also found that glucuronidation of the compound emodin-8-O-β-D-glucoside acts as the main isoform in AQ hydroxylation in HLM and DLM. Total microsomal intrinsic clearance values for AQ were greatest in mouse microsomes, followed by those in dog, human, and rat microsomes. Conclusion: The absorption of different anthrquinone compounds varied based on the compound structure, the metabolism types and products of anthraquinones in liver microsomes were different in different species. These findings provide vital information for a deeper unuunderstanding of the metabolism of AQs.

  9. Photoeffects of near ultraviolet light upon a polycyclic aromatic hydrocarbon exposed to mouse skin microsomes

    International Nuclear Information System (INIS)

    Peirano, W.B.

    1991-01-01

    Near ultraviolet (UV) light has been reported to both enhance and inhibit the tumor incidence in mice dermally exposed to benzo(a)pyrene (BaP) or polycyclic aromatic hydrocarbon (PAH) mixtures. Near UV light interacts with PAHs producing a variety of oxygenated products such as phenols, endoperoxides and quinones. However, little is known about BaP products formed from near UV irradiation of BaP-exposed mouse skin. Therefore, 14 C-BaP was incubated with 3-methylcholanthrene (3-MC) induced C 3 H/HeJ and DBA/2J mouse skin microsomes with or without a 365 nm light source. The results indicated that the concurrent 365 nm light irradiation of induced mouse skin microsomes and BaP greatly enhanced the total conversion of BaP to its products, approximately 3-fold for the C 3 H/HeJ and approximately 7-fold for the DBA/2J mouse microsomes, compared to the induced mouse skin microsomes and BaP alone. HPLC analyses of organic extracts indicated a more than additive enhancement of the formation of most of the individual cochromatographed BaP metabolites due to the combined interaction of 365 nm light with BaP and skin microsomes. Similar interactions were observed using benz(a)anthracene (BaA) in this system. These data show that near UV light alters the metabolic profile of PAHs produced by mouse skin microsomes

  10. UPLC/MS MS data of testosterone metabolites in human and zebrafish liver microsomes and whole zebrafish larval microsomes

    Directory of Open Access Journals (Sweden)

    Moayad Saad

    2018-02-01

    Full Text Available This article represents data regarding a study published in Toxicology in vitro entitled “ in vitro CYP-mediated drug metabolism in the zebrafish (embryo using human reference compounds” (Saad et al., 2017 [1]. Data were acquired with ultra-performance liquid chromatography – accurate mass mass spectrometry (UPLC-amMS. A full spectrum scan was conducted for the testosterone (TST metabolites from the microsomal stability assay in zebrafish and humans. The microsomal proteins were extracted from adult zebrafish male (MLM and female (FLM livers, whole body homogenates of 96 h post fertilization larvae (EM and a pool of human liver microsomes from 50 donors (HLM. Data are expressed as the abundance from the extracted ion chromatogram of the metabolites.

  11. Microsomal UDP-glucuronyltransferase-catalyzed bilirubin diglucuronide formation in human liver

    NARCIS (Netherlands)

    Peters, W. H.; Jansen, P. L.

    1986-01-01

    Human liver microsomal bilirubin UDP-glucuronyltransferase catalyzes formation of bilirubin mono- and diglucuronide. KmUDPGA and Vmax of the enzyme are 0.6 mM and 1.69 nmol/mg protein X min. In vitro, bilirubin readily dissolves in the microsomal lipid phase. Taking this into account a Kmbilirubin

  12. Oxidation of esterified arachidonate by rat liver microsomes

    International Nuclear Information System (INIS)

    Davis, H.W.; Suzuki, T.; Schenkman, J.B.

    1986-01-01

    The authors have previously demonstrated a relationship between phospholipid arachidonate in liver microsomes and malondialdehyde (MDA) formation during lipid peroxidation. In this study arachidonic acid (U- 14 C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37 0 C for 15 minutes. The microsomes were pelleted by centrifugation and the labeled products in the supernatant were isolated by a solid phase method. Pellets were hydrolyzed with phospholipase A 2 and extracted with diethyl ether and the products from both fractions were separated by reverse phase HPLC. The results show that (1) oxidation occurs in all of the major phospholipids but that phosphatidylethanolamine is the most susceptible; (2) a linear correlation exists between MDA formation and supernatant radioactivity; (3) several different polar products are found in both the supernatant and the hydrolyzed pellet but that the ratios of product peaks in HPLC do not change during the peroxidation, indicating no secondary metabolism or propagation; and (4) cytochrome P-450 is not involved in the peroxidative reactions since no oxidation occurs in the absence of Fe 3+ and since product formation is unaffected in the presence of carbon monoxide

  13. Comparative Metabolism Study of Five Protoberberine Alkaloids in Liver Microsomes from Rat, Rhesus Monkey, and Human.

    Science.gov (United States)

    Li, Yan; Zhou, Yanyan; Si, Nan; Han, Lingyu; Ren, Wei; Xin, Shaokun; Wang, Hongjie; Zuo, Ran; Wei, Xiaolu; Yang, Jian; Zhao, Haiyu; Bian, Baolin

    2017-11-01

    Protoberberine alkaloids including berberine, palmatine, jatrorrhizine, coptisine, and epiberberine are major components in many medicinal plants. They have been widely used for the treatment of cancer, inflammation, diabetes, depression, hypertension, and various infectious areas. However, the metabolism of five protoberberine alkaloids among different species has not been clarified previously. In order to elaborate on the in vitro metabolism of them, a comparative analysis of their metabolic profile in rat, rhesus monkey, and human liver microsomes was carried out using ultrahigh-performance liquid chromatography coupled with a high-resolution linear trap quadrupole-Orbitrap mass spectrometer (UHPLC-electrospray ionization-Orbitrap MS) for the first time. Each metabolite was identified and semiquantified by its accurate mass data and peak area. Fifteen metabolites were characterized based on accurate MS/MS spectra and the proposed MS/MS fragmentation pathways including demethylation, hydroxylation, and methyl reduction. Among them, the content of berberine metabolites in human liver microsomes was similar with those in rhesus monkey liver microsomes, whereas berberine in rat liver microsomes showed no demethylation metabolites and the content of metabolites showed significant differences with that in human liver microsomes. On the contrary, the metabolism of palmatine in rat liver microsomes resembled that in human liver microsomes. The content of jatrorrhizine metabolites presented obvious differences in all species. The HR-ESI-MS/MS fragmentation behavior of protoberberine alkaloids and their metabolic profile in rat, rhesus monkey, and human liver microsomes were investigated for the first time. The results demonstrated that the biotransformation characteristics of protoberberine alkaloids among different species had similarities as well differences that would be beneficial for us to better understand the pharmacological activities of protoberberine alkaloids

  14. Trapping of cis-2-butene-1,4-dial to measure furan metabolism in human liver microsomes by cytochrome P450 enzymes.

    Science.gov (United States)

    Gates, Leah A; Lu, Ding; Peterson, Lisa A

    2012-03-01

    Furan is a liver toxicant and carcinogen in rodents. It is classified as a possible human carcinogen, but the human health effects of furan exposure remain unknown. The oxidation of furan by cytochrome P450 (P450) enzymes is necessary for furan toxicity. The product of this reaction is the reactive α,β-unsaturated dialdehyde, cis-2-butene-1,4-dial (BDA). To determine whether human liver microsomes metabolize furan to BDA, a liquid chromatography/tandem mass spectrometry method was developed to detect and quantify BDA by trapping this reactive metabolite with N-acetyl-l-cysteine (NAC) and N-acetyl-l-lysine (NAL). Reaction of NAC and NAL with BDA generates N-acetyl-S-[1-(5-acetylamino-5-carboxypentyl)-1H-pyrrol-3-yl]-l-cysteine (NAC-BDA-NAL). Formation of NAC-BDA-NAL was quantified in 21 different human liver microsomal preparations. The levels of metabolism were comparable to that observed in F-344 rat and B6C3F1 mouse liver microsomes, two species known to be sensitive to furan-induced toxicity. Studies with recombinant human liver P450s indicated that CYP2E1 is the most active human liver furan oxidase. The activity of CYP2E1 as measured by p-nitrophenol hydroxylase activity was correlated to the extent of NAC-BDA-NAL formation in human liver microsomes. The formation of NAC-BDA-NAL was blocked by CYP2E1 inhibitors but not other P450 inhibitors. These results suggest that humans are capable of oxidizing furan to its toxic metabolite, BDA, at rates comparable to those of species sensitive to furan exposure. Therefore, humans may be susceptible to furan's toxic effects.

  15. Studies on the transverse localization of lysophospholipase II in bovine liver microsomes by immunological techniques

    NARCIS (Netherlands)

    Moonen, H.; Bosch, H. van den

    1979-01-01

    1. 1. Lysophospholipase activity solubilized from bovine liver microsomes could be precipitated for more than 80% by antibodies evoked in rabbits against the purified bovine liver lysophospholipase II. 2. 2. After solubilization of the microsomes in 1.5% sodium deoxycholate, an immunoprecipitate

  16. Influence of acute and chronic administration of methadone hydrochloride on NADPH-cytochrome c reductase and cytochrome P-450 of mouse liver microsomes.

    Science.gov (United States)

    Datta, R K; Johnson, E A; Bhattacharjee, G; Stenger, R J

    1976-03-01

    Administration of a single acute dose (20 mg/kg body weight) of methadone hydrochloride to both male and female mice increased the specific activity of NADPH-cytochrome c reductase and did not change much the content of cytochrome P-450 of their liver microsomes. Administration of multiple acute doses of methadone in male mice increased the specific activity of cytochrome c reductase and the content of cytochrome P-450 of their liver microsomes. Chronic administration of progressively increasing doses of methadone (up to 40 mg/kg body weight) to male mice increased the specific activity of c reductase. Similar chronic administration of methadone up to 28 mg/kg body weight also increased the microsomal content of P-450, but with higher doses of methadone, the content of P-450 declined and finally dropped slightly below control levels. The levels of c reductase activity and P-450 content returned to normal about two weeks after discontinuation of methadone administration.

  17. In vitro metabolism studies of 18F-labeled 1-phenylpiperazine using mouse liver S9 fraction

    International Nuclear Information System (INIS)

    Ryu, Eun Kyoung; Choe, Yearn Seong; Kim, Dong Hyun; Ko, Bong-Ho; Choi, Yong; Lee, Kyung-Han; Kim, Byung-Tae

    2006-01-01

    The in vitro metabolism of 1-(4-[ 18 F]fluoromethylbenzyl)-4-phenylpiperazine ([ 18 F]1) and 1-(4-[ 18 F]fluorobenzyl)-4-phenylpiperazine ([ 18 F]2) was investigated using mouse liver S9 fraction. Results were compared to those of in vivo metabolism using mouse blood and bone and to in vitro metabolism using mouse liver microsomes. Defluorination was the main metabolic pathway for [ 18 F]1 in vitro and in vivo. Based on TLC, HPLC and LC-MS data, [ 18 F]fluoride ion and less polar radioactive metabolites derived from aromatic ring oxidation were detected in vitro, and the latter metabolites were rapidly converted into the former with time, whereas only the [ 18 F]fluoride ion was detected in vivo. Similarly, the in vitro metabolism of [ 18 F]2 using either S9 fraction or microsomes showed the same pattern as the in vivo method using blood; however, the radioactive metabolites derived from aromatic ring oxidation were not detected in vivo. These results demonstrate that liver S9 fraction can be widely used to investigate the intermediate radioactive metabolites and to predict the in vivo metabolism of radiotracers

  18. Purification and characterization of an amidohydrolase for N4-long-chain fatty acyl derivatives of 1-beta-D-arabinofuranosylcytosine from mouse liver microsomes.

    Science.gov (United States)

    Hori, K; Tsuruo, T; Tsukagoshi, S; Sakurai, Y

    1984-03-01

    N4-Long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase, a metabolizing enzyme for N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with long-chain fatty acids, was purified from mouse liver microsomes. The purification was accomplished by solubilization of liver microsomes with Triton X-100, diethylaminoethyl cellulose chromatography, gel filtrations, hydroxyapatite chromatography, and concanavalin A:Sepharose chromatography. On sodium dodecyl sulfate:polyacrylamide gel electrophoresis, the purified enzyme preparation produced a single protein band with a molecular weight of 54,000. The enzyme had an optimal pH of 9.0, and the Michaelis constant for N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was 67 microM. The thiols such as dithiothreitol or 2-mercaptoethanol stabilized the enzyme and stimulated its activity. p-Chloromercuribenzoate, N-ethylmaleimide, diisopropylfluorophosphate, and phenylmethylsulfonyl fluoride strongly inhibited the reaction. Bovine serum albumin markedly stimulated the enzyme activity, whereas detergents such as Triton X-100, deoxycholate, and sodium dodecyl sulfate had little effect. The enzyme did not require monovalent or divalent cations. Among the series of N4-acyl derivatives of 1-beta-D-arabinofuranosylcytosine with different chain lengths of acyl residues, the purified enzyme preferentially hydrolyzed the derivatives with long-chain fatty acids (C12 to C18), and N4-palmitoyl-1-beta-D-arabinofuranosylcytosine was the most susceptible. The purified enzyme was inactive on various N-acylamino acids, amides, oligopeptides, proteins, N-acylsphingosines (ceramides), triglyceride, lecithin, and lysolecithin. These results suggest that N4-long-chain fatty acyl-1-beta-D-arabinofuranosylcytosine amidohydrolase may be a new type of linear amidase.

  19. Metabolism of methylstenbolone studied with human liver microsomes and the uPA⁺/⁺-SCID chimeric mouse model.

    Science.gov (United States)

    Geldof, Lore; Lootens, Leen; Polet, Michael; Eichner, Daniel; Campbell, Thane; Nair, Vinod; Botrè, Francesco; Meuleman, Philip; Leroux-Roels, Geert; Deventer, Koen; Eenoo, Peter Van

    2014-07-01

    Anti-doping laboratories need to be aware of evolutions on the steroid market and elucidate steroid metabolism to identify markers of misuse. Owing to ethical considerations, in vivo and in vitro models are preferred to human excretion for nonpharmaceutical grade substances. In this study the chimeric mouse model and human liver microsomes (HLM) were used to elucidate the phase I metabolism of a new steroid product containing, according to the label, methylstenbolone. Analysis revealed the presence of both methylstenbolone and methasterone, a structurally closely related steroid. Via HPLC fraction collection, methylstenbolone was isolated and studied with both models. Using HLM, 10 mono-hydroxylated derivatives (U1-U10) and a still unidentified derivative of methylstenbolone (U13) were detected. In chimeric mouse urine only di-hydroxylated metabolites (U11-U12) were identified. Although closely related, neither methasterone nor its metabolites were detected after administration of isolated methylstenbolone. Administration of the steroid product resulted mainly in the detection of methasterone metabolites, which were similar to those already described in the literature. Methylstenbolone metabolites previously described were not detected. A GC-MS/MS multiple reaction monitoring method was developed to detect methylstenbolone misuse. In one out of three samples, previously tested positive for methasterone, methylstenbolone and U13 were additionally detected, indicating the applicability of the method. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Photoaffinity labeling of steroid 5 alpha-reductase of rat liver and prostate microsomes

    International Nuclear Information System (INIS)

    Liang, T.; Cheung, A.H.; Reynolds, G.F.; Rasmusson, G.H.

    1985-01-01

    21-Diazo-4-methyl-4-aza-5 alpha-pregnane-3,20-dione (Diazo-MAPD) inhibits steroid 5 alpha-reductase in liver microsomes of female rats with a K/sub i/ value of 8.7 +/- 1.7 nM, and the inhibition is competitive with testosterone. It also inhibits the binding of a 5 alpha-reductase inhibitor, [ 3 H] 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([ 3 H]4-MA), to the enzyme in liver microsomes. The inhibition of 5 alpha-reductase activity and of inhibitor binding activity by diazo-MAPD becomes irreversible upon UV irradiation. [1,2- 3 H]Diazo-MAPD binds to a single high affinity site in liver microsomes of female rats, and this binding requires NADPH. Without UV irradiation, this binding is reversible, and it becomes irreversible upon UV irradiation. Both the initial reversible binding and the subsequent irreversible conjugation after UV irradiation are inhibited by inhibitors (diazo-MAPD and 4-MA) and substrates (progesterone and testosterone) of 5 alpha-reductase, but they are not inhibited by 5 alpha-reduced steroids. Photoaffinity labeled liver microsomes of female rats were solubilized and fractionated by high performance gel filtration. The radioactive conjugate eluted in one major peak at Mr 50,000

  1. In vitro biotransformation of flavonoids by rat liver microsomes

    DEFF Research Database (Denmark)

    Nielsen, S. E.; Breinholt, V.; Justesen, U.

    1998-01-01

    1. Sixteen naturally occurring flavonoids were investigated as substrates for cytochrome P450 in uninduced and Aroclor 1254-induced rat liver microsomes. Naringenin, hesperetin, chrysin, apigenin, tangeretin, kaempferol, galangin and tamarixetin were all metabolized extensively by induced rat liver...... pathway leading to the corresponding 3',4'-dihydroxylated flavonoids either by hydroxylation or demethylation. Structural requirements for microsomal hydroxylation appeared to be a single or no hydroxy group on the B-ring of the flavan nucleus. The presence of two or more hydroxy groups on the B......-ring seemed to prevent further hydroxylation. The results indicate that demethylation only occurs in the B-ring when the methoxy group is positioned at C-4'-, and not at the C-3'-position. 3. The CYP1A isozymes were found to be the main enzymes involved in flavonoid hydroxylation, whereas other cytochrome P...

  2. A human cytochrome P-450 is recognized by anti-liver/kidney microsome antibodies in autoimmune chronic hepatitis.

    Science.gov (United States)

    Kiffel, L; Loeper, J; Homberg, J C; Leroux, J P

    1989-02-28

    1- Anti-liver/kidney microsome autoantibodies type 1 (anti-LKM1), observed in some children with chronic active hepatitis, were used to isolate their antigen in human liver microsomes. A protein, called P-LKM1 was thus purified. This protein was recognized by a rabbit antiserum directed against the related human cytochromes P-450 bufI and P-450 bufII. 2- A human liver microsomal protein immunoprecipitated with anti-LKM1 sera was also recognized by anti cytochromes P-450 bufI/II antibodies. 3- Anti-LKM1 antibodies potently inhibited microsomal bufuralol 1'-hydroxylation. These results displayed the possible identity between cytochrome P-450 bufI/II and LKM1 antigen.

  3. Glutathione delays varies as-tocopherol oxidation and subsequent lipid peroxidation in rat liver microsomes

    International Nuclear Information System (INIS)

    Robey, S.; Mavis, R.

    1986-01-01

    A method has been developed for in vitro trace radiolabeling of rat liver microsomes with 3 H-α-tocopherol (αT*) which allows virtually complete oxidation of the αT* under oxidizing conditions. The supernatant of a 16,000 xg centrifugation of homogenized rat liver, containing the cytosolic rat liver vitamin E (VE) transfer protein, was incubated with an ethanolic solution of αT* for 10 minutes at 37 0 C. Labeled microsomes were collected in the washed 100,000 xg pellet. Microsomes were then incubated with 30 μM Fe 2+ in an NADPH-generating system, and both production of malondialdehyde (MDA) (a product of lipid peroxidation) and oxidation of αT* were monitored over a time course in the presence and absence of glutathione (GSH). The results indicate virtually complete oxidation of αT* precedes significant membrane lipid peroxidation, and that addition of 5 mM GSH delays both αT* oxidation and subsequent MDA production. This suggests that the previously observed VE-dependent heat labile inhibition of microsomal lipid peroxidation by GSH involves maintaining membrane levels of α-tocopherol

  4. Three conazoles increase hepatic microsomal retinoic acid metabolism and decrease mouse hepatic retinoic acid levels in vivo

    International Nuclear Information System (INIS)

    Chen, P.-J.; Padgett, William T.; Moore, Tanya; Winnik, Witold; Lambert, Guy R.; Thai, Sheau-Fung; Hester, Susan D.; Nesnow, Stephen

    2009-01-01

    Conazoles are fungicides used in agriculture and as pharmaceuticals. In a previous toxicogenomic study of triazole-containing conazoles we found gene expression changes consistent with the alteration of the metabolism of all trans-retinoic acid (atRA), a vitamin A metabolite with cancer-preventative properties (Ward et al., Toxicol. Pathol. 2006; 34:863-78). The goals of this study were to examine effects of propiconazole, triadimefon, and myclobutanil, three triazole-containing conazoles, on the microsomal metabolism of atRA, the associated hepatic cytochrome P450 (P450) enzyme(s) involved in atRA metabolism, and their effects on hepatic atRA levels in vivo. The in vitro metabolism of atRA was quantitatively measured in liver microsomes from male CD-1 mice following four daily intraperitoneal injections of propiconazole (210 mg/kg/d), triadimefon (257 mg/kg/d) or myclobutanil (270 mg/kg/d). The formation of both 4-hydroxy-atRA and 4-oxo-atRA were significantly increased by all three conazoles. Propiconazole-induced microsomes possessed slightly greater metabolizing activities compared to myclobutanil-induced microsomes. Both propiconazole and triadimefon treatment induced greater formation of 4-hydroxy-atRA compared to myclobutanil treatment. Chemical and immuno-inhibition metabolism studies suggested that Cyp26a1, Cyp2b, and Cyp3a, but not Cyp1a1 proteins were involved in atRA metabolism. Cyp2b10/20 and Cyp3a11 genes were significantly over-expressed in the livers of both triadimefon- and propiconazole-treated mice while Cyp26a1, Cyp2c65 and Cyp1a2 genes were over-expressed in the livers of either triadimefon- or propiconazole-treated mice, and Cyp2b10/20 and Cyp3a13 genes were over-expressed in the livers of myclobutanil-treated mice. Western blot analyses indicated conazole induced-increases in Cyp2b and Cyp3a proteins. All three conazoles decreased hepatic atRA tissue levels ranging from 45-67%. The possible implications of these changes in hepatic atRA levels

  5. ROLE OF LEPTIN ON CYTOCHROME P-450 AND SOME LIVER MICROSOMAL ENZYMES ACTIVITIES IN THE OBESE AND LEAN MICE

    International Nuclear Information System (INIS)

    HEBEISHY, M.I.A.; MAZEN, G.M.A.; SHAHIN, M.I

    2008-01-01

    Leptin is a hormone that is secreted by adipocytes and regulates body weight through its effect on satiety and energy metabolism. The obese mouse is deficient in this protein and is characterized by obesity and other metabolic disorders. This study investigated the alterations of several hepatic cytochrome P 4 -5 0 (CYP), conjugation and antioxidant enzymes in lean and obese mice and the role of leptin in the modulation of these enzymes. Lean and obese male mice were injected with leptin (100 μg / rat) for 15 days. The obtained results revealed that administration of leptin to lean mice caused a significant elevation in the level of blood glucose, serum insulin, 6α, 6β, 16α- hydroxylation of testosterone, the activity of CYP 1 A 1 , CYP 4 A and GSH reductase in liver microsomes while serum corticosterone and the activity of total GSH were significantly decreased when compared to lean control mice. Moreover, obese mice treated with leptin recorded significant reduction in body weight, blood glucose concentration, serum levels of insulin and corticosterone, 7α and 16α- hydroxylation of testosterone, the activity of CYP 1A 1, CYP 2 B 1 and CYP 4 A and GST in liver microsomes. On the other hand, 6α, 6β-hydroxylation of testosterone, the activity of CYP 2 E 1 and GSH reductase in liver microsome were significantly increased when compared to obese control mice. The mechanism for the observed alterations may be due to direct leptin effects or via indirect alterations in insulin, corticosterone and/or growth hormone

  6. Incubation of 14C-trichloroethylene vapor with rat liver microsomes: uptake of radioactivity and covalent protein binding of metabolites

    International Nuclear Information System (INIS)

    Bolt, H.M.; Wolowski, L.; Buchter, A.; Bolt, W.; Gil, D.L.

    1977-01-01

    Microsomal uptake irreversible protein binding of labelled trichloroehtylene was measured following incubation with rat liver microsomes in an all-glass vacuum system. If the cofactor for oxidative metabolism, NADPH, is not added, the gaseous trichloroethylene rapidly equilibrates with the microsomal suspension. Addition of NADPH results in a further uptake of 14 C-trichloroethylene from the gas phase, linearly with time, which is due to enzymic metabolism. This part of uptake is inhibited by some arylimidazoles and 1.2.3-benzothiadiazoles. The compounds of greatest inhibitory potency were 6-chloro-1.2.3-benzothiadiazole and 5.6-dimethyl-1.2.3-benzothiadiazole. Part of the metabolites of 14 C-trichloroethylene formed by rat liver microsomes were irreversibly bound to microsomal protein, amounting up to 1 nmol per mg microsomal protein per hour. Model experiments on uptake of 14 C-trichloroethylene from the gas phase by albumin solutions and liposomal suspensions (from lecithin) showed a rapid equilibration of trichloroethylene also with these systems. Comparison with previous analogous data on vinyl chloride revealed an about 10 times higher affinity of trichloroethylene to albumin and lipid, consistent with the behaviour of both compounds in the rat liver microsomal system. (orig.) [de

  7. Cranberry juice suppressed the diclofenac metabolism by human liver microsomes, but not in healthy human subjects

    Science.gov (United States)

    Ushijima, Kentarou; Tsuruoka, Shu-ichi; Tsuda, Hidetoshi; Hasegawa, Gohki; Obi, Yuri; Kaneda, Tae; Takahashi, Masaki; Maekawa, Tomohiro; Sasaki, Tomohiro; Koshimizu, Taka-aki; Fujimura, Akio

    2009-01-01

    AIM To investigate a potential interaction between cranberry juice and diclofenac, a substrate of CYP2C9. METHODS The inhibitory effect of cranberry juice on diclofenac metabolism was determined using human liver microsome assay. Subsequently, we performed a clinical trial in healthy human subjects to determine whether the repeated consumption of cranberry juice changed the diclofenac pharmacokinetics. RESULTS Cranberry juice significantly suppressed diclofenac metabolism by human liver microsomes. On the other hand, repeated consumption of cranberry juice did not influence the diclofenac pharmacokinetics in human subjects. CONCLUSIONS Cranberry juice inhibited diclofenac metabolism by human liver microsomes, but not in human subjects. Based on the present and previous findings, we think that although cranberry juice inhibits CYP2C9 activity in vitro, it does not change the pharmacokinetics of medications metabolized by CYP2C9 in clinical situations. PMID:19694738

  8. Major antigen of liver kidney microsomal autoantibodies in idiopathic autoimmune hepatitis is cytochrome P450db1.

    OpenAIRE

    Manns, M P; Johnson, E F; Griffin, K J; Tan, E M; Sullivan, K F

    1989-01-01

    Type 1, liver kidney microsomal autoantibodies (LKM-1) are associated with a subgroup of idiopathic autoimmune type, chronic active hepatitis (CAH). The antigenic specificity of LKM-1 autoantibodies from 13 patients was investigated by immunoblot analysis of human liver microsomal proteins. Polypeptides of 50, 55, and 64 kD were detected with these antisera. A high titer LKM-1 serum was selected to screen a human liver lambda gt11 cDNA expression library, resulting in the isolation of several...

  9. Potent inhibition of cytochrome P450 2B6 by sibutramine in human liver microsomes.

    Science.gov (United States)

    Bae, Soo Hyeon; Kwon, Min Jo; Choi, Eu Jin; Zheng, Yu Fen; Yoon, Kee Dong; Liu, Kwang-Hyeon; Bae, Soo Kyung

    2013-09-05

    The present study was performed to evaluate the potency and specificity of sibutramine as an inhibitor of the activities of nine human CYP isoforms in liver microsomes. Using a cocktail assay, the effects of sibutramine on specific marker reactions of the nine CYP isoforms were measured in human liver microsomes. Sibutramine showed potent inhibition of CYP2B6-mediated bupropion 6-hydroxylation with an IC50 value of 1.61μM and Ki value of 0.466μM in a competitive manner at microsomal protein concentrations of 0.25mg/ml; this was 3.49-fold more potent than the typical CYP2B6 inhibitor thio-TEPA (Ki=1.59μM). In addition, sibutramine slightly inhibited CYP2C19 activity (Ki=16.6μM, noncompetitive inhibition) and CYP2D6 activity (Ki=15.7μM, noncompetitive inhibition). These observations indicated 35.6- and 33.7-fold decreases in inhibition potency, respectively, compared with that of CYP2B6 by sibutramine. However, no inhibition of CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6, or CYP2E1 activities was observed. In addition, the CYP2B6 inhibitory potential of sibutramine was enhanced at a lower microsomal protein concentration of 0.05mg/ml. After 30min preincubation of human liver microsomes with sibutramine in the presence of NADPH, no shift in IC50 was observed in terms of inhibition of the activities of the nine CYPs, suggesting that sibutramine is not a time-dependent inactivator. These observations suggest that sibutramine is a selective and potent inhibitor of CYP2B6 in vitro, whereas inhibition of other CYPs is substantially lower. These in vitro data support the use of sibutramine as a well-known inhibitor of CYP2B6 for routine screening of P450 reversible inhibition when human liver microsomes are used as the enzyme source. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  10. CHARACTERIZATION OF HUMAN LIVER MICROSOMAL UDP-GLYCOSYLTRANSFERASES USING PHOTOAFFINITY ANALOGS

    NARCIS (Netherlands)

    LITTLE, JM; DRAKE, RR; VONK, R; KUIPERS, F; LESTER, R; RADOMINSKA, A

    The photoaffinity analogs [beta-P-32]5-azido-UDP-glucuronic acid ([P-32]5N3UDP-GlcUA) and [beta-P-32]5-azido-UDP-glucose ([P-32]5N(3)UDP-Glc) were used to characterize UDP-glycosyl-transferases of microsomes prepared from human liver. Photoincorporation of both probes into proteins in the 50- to

  11. Metabolism of indole alkaloid tumor promoter, (-)-indolactam V, which has the fundamental structure of teleocidins, by rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, N.; Irie, K.; Tokuda, H.; Koshimizu, K.

    1987-07-01

    Metabolic activation and/or deactivation of indole alkaloid tumor promoter, (-)-indolactam V (ILV), was examined using rat liver microsomes. Reaction of ILV with the microsomes supplemented with NADPH and MgCl/sub 2/ gave three major metabolites, which were identified as (-)-N13-desmethylindolactam V and two diastereomers of (-)-2-oxyindolactam V at C-3. The tumor-promoting activities of these metabolites were evaluated by induction of Epstein-Barr virus early antigen and inhibition of specific binding of (/sup 3/H)-12-O-tetradecanoylphorbol-13-acetate to a mouse epidermal particulate fraction, and proved to be conspicuously lower than that of ILV. These results demonstrate that the metabolism of ILV results in detoxification, and that it itself is the tumor-promoting entity. Studies on the enzymes concerned with this metabolism suggested the involvement of cytochrome P-450-containing mixed-function oxidases. Similar deactivation seems to be possible by skin, where the mixed-function oxidases are known to exist.

  12. The effects of gender, age, ethnicity, and liver cirrhosis on cytochrome P450 enzyme activity in human liver microsomes and inducibility in cultured human hepatocytes

    International Nuclear Information System (INIS)

    Parkinson, Andrew; Mudra, Daniel R.; Johnson, Cory; Dwyer, Anne; Carroll, Kathleen M.

    2004-01-01

    We have measured cytochrome P450 (CYP) activity in nearly 150 samples of human liver microsomes and 64 samples of cryopreserved human hepatocytes, and we have performed induction studies in over 90 preparations of cultured human hepatocytes. We have analyzed these data to examine whether the expression of CYP enzyme activity in liver microsomes and isolated hepatocytes or the inducibility of CYP enzymes in cultured hepatocytes is influenced by the gender, age, or ethnicity of the donor (the latter being limited to Caucasians, African Americans, and Hispanics due to a paucity of livers from Asian donors). In human liver microsomes, there were no statistically significant differences (P > 0.05) in CYP activity as a function of age, gender, or ethnicity with one exception. 7-Ethoxyresorufin O-dealkylase (CYP1A2) activity was greater in males than females, which is consistent with clinical observation. Liver microsomal testosterone 6β-hydroxylase (CYP3A4) activity was slightly greater in females than males, but the difference was not significant. However, in cryopreserved human hepatocytes, the gender difference in CYP3A4 activity (females = twice males) did reach statistical significance, which supports the clinical observation that females metabolize certain CYP3A4 substrates faster than do males. Compared with those from Caucasians and African Americans, liver microsomes from Hispanics had about twice the average activity of CYP2A6, CYP2B6, and CYP2C8 and half the activity of CYP1A2, although this apparent ethnic difference may be a consequence of the relatively low number of Hispanic donors. Primary cultures of hepatocytes were treated with β-naphthoflavone, an inducer of CYP1A2, phenobarbital or rifampin, both of which induce CYP2B6, CYP2C9, CYP2C19, and CYP3A4, albeit it to different extents. Induction of these CYP enzymes in freshly cultured hepatocytes did not appear to be influenced by the gender or age of the donor. Furthermore, CYP3A4 induction in

  13. Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis

    OpenAIRE

    Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F

    1998-01-01

    Background—Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). 
Aims—Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. 
Patients—Twenty one patients with type 2 AIH were studied. 
Methods—A...

  14. Inhibition of rat liver microsomal lipid peroxidation by N-acyldehydroalanines: An in vitro comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Buc-Calderon, P.; Roberfroid, M. (Universite Catholique de Louvain, Brussels (Belgium))

    1989-09-01

    Captodative substituted olefins are radical scavengers which react with free radicals to form stabilized radical adducts. One of those compounds, N-(paramethoxyphenylacetyl)dehydroalanine (AD-5), may react and scavenge both superoxide anion (O-2) and alk-oxyl radicals (RO.), and in this way prevent the appearance of their mediated biological effects. Nitrofurantoin and tert-butyl hydroperoxide were used as model compounds to stimulate free radical production and their mediated lipid peroxidation in rat liver microsomes. In addition, lipid peroxidation was also initiated by exposure of rat liver microsomal suspensions to ionizing radiation (gamma rays). The microsomal lipid peroxidation induced by these chemicals and physical agents was inhibited by the addition of AD-5. These effects were dose-dependent in a millimolar range of concentration. In addition, AD-5 has no effect on microsomal electron transport, showing that NADPH-cytochrome P450 reductase activity was not modified. These data, together with the comparisons of the effects of AD-5 and some antioxidant molecules such as superoxide dismutase, uric acid, and mannitol, support the conclusion that inhibition of lipid peroxidation by AD-5 is the result of its free radical scavenger activity. In addition, the inhibitory effect of AD-5 on microsomal lipid peroxidation was dependent of the nature of the free radical species involved in the initiation of the process, suggesting that O-2 is scavenged more efficiently than RO.

  15. Identification of a tryptanthrin metabolite in rat liver microsomes by liquid chromatography/electrospray ionization-tandem mass spectrometry.

    Science.gov (United States)

    Lee, Sang Kyu; Kim, Ghee Hwan; Kim, Dong Hyeon; Kim, Dong Hyun; Jahng, Yurngdong; Jeong, Tae Cheon

    2007-10-01

    Tryptanthrin originally isolated from Isatis tinctoria L. has been characterized to have anti-inflammatory activities through the dual inhibition of cyclooxygenase-2 and 5-lipoxygenase mediated prostaglandin and leukotriene syntheses. To characterize phase I metabolite(s), tryptanthrin was incubated with rat liver microsomes in the presence of NADPH-generating system. One metabolite was identified by liquid chromatography/electrospray ionization-tandem mass spectrometry. M1 could be identified as a metabolite mono-hydroxylated on the aromatic ring of indole moiety from the MS(2) spectra of protonated tryptanthrin and M1. The structure of metabolite was confirmed as 8-hydroxytryptanthrin with a chemically synthesized authentic standard. The formation of M1 was NADPH-dependent and was inhibited by SKF-525A, a general CYP-inhibitor, indicating the cytochrome P450 (CYP)-mediated reaction. In addition, it was proposed that M1 might be formed by CYP 1A in rat liver microsomes from the experiments with enriched rat liver microsomes.

  16. Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoko, E-mail: y-watanabe@nichiyaku.ac.jp [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Kojima, Hiroyuki; Takeuchi, Shinji [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Uramaru, Naoto [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Sanoh, Seigo [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Sugihara, Kazumi [Faculty of Pharmaceutical Science, Hiroshima International University, Koshingai 5-1-1, Kure, Hiroshima 737-0112 (Japan); Kitamura, Shigeyuki [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Ohta, Shigeru [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)

    2015-01-15

    Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes. - Highlights: • Metabolic modification of the endocrine-disrupting activity of BP-3 was examined. • 2,4,5-TriOH BP and 3-OH BP-3 were identified as new BP-3 metabolites. • 2,4-DiOH BP and 2,3,4-triOH BP exhibited high or similar estrogenic activities. • Estrogenic activity of BP-3 was enhanced by incubation with rat liver

  17. Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis.

    Science.gov (United States)

    Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F B

    1998-05-01

    Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. Twenty one patients with type 2 AIH were studied. All sera were tested by indirect immunofluorescence, counterimmunoelectrophoresis, and immunoblotting visualised by enhanced chemiluminescence. To evaluate LKM1 and LC1 levels, the 50 kDa microsomal reactivity (corresponding to CYP2D6) and the 58 kDa cytosolic reactivity were quantified by densitometric analysis. Seven patients were positive for LKM1, nine for LC1, and five for both. Serial serum samples at onset and during immunosuppressive treatment were analysed in 13 patients (four positive for LKM1, six positive for LC1 and three positive for both). During remission, LKM1 concentration remained essentially unchanged in six of seven patients, and decreased in only one. Conversely, in two of nine patients, LC1 was completely lost, and, in the remaining seven, LC1 concentration was reduced by more than 50%. After immunosuppression tapering or withdrawal, flare ups of liver necrosis ensued with increasing LC1 concentration, but not LKM1. LC1 concentration, at variance with that of LKM1, parallels liver disease activity, and its participation in the pathogenic mechanisms of liver injury can be hypothesised.

  18. Metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy LSD (O-H-LSD) in human liver microsomes and cryopreserved human hepatocytes.

    Science.gov (United States)

    Klette, K L; Anderson, C J; Poch, G K; Nimrod, A C; ElSohly, M A

    2000-10-01

    The metabolism of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy lysergic acid diethylamide (O-H-LSD) was investigated in liver microsomes and cyropreserved hepatocytes from humans. Previous studies have demonstrated that O-H-LSD is present in human urine at concentrations 16-43 times greater than LSD, the parent compound. Additionally, these studies have determined that O-H-LSD is not generated during the specimen extraction and analytical processes or due to parent compound degradation in aqueous urine samples. However, these studies have not been conclusive in demonstrating that O-H-LSD is uniquely produced during in vivo metabolism. Phase I drug metabolism was investigated by incubating human liver microsomes and cryopreserved human hepatocytes with LSD. The reaction was quenched at various time points, and the aliquots were extracted using liquid partitioning and analyzed by liquid chromatography-mass spectrometry. O-H-LSD was positively identified in all human liver microsomal and human hepatocyte fractions incubated with LSD. In addition, O-H-LSD was not detected in any microsomal or hepatocyte fraction not treated with LSD nor in LSD specimens devoid of microsomes or hepatocytes. This study provides definitive evidence that O-H-LSD is produced as a metabolic product following incubation of human liver microsomes and hepatocytes with LSD.

  19. [Comparative metabolism of three amide alkaloids from Piper longum in five different species of liver microsomes].

    Science.gov (United States)

    He, Huan; Guo, Wei-Wei; Chen, Xiao-Qing; Zhao, Hai-Yu; Wu, Xia

    2016-08-01

    Piperine, piperlonguminine and pellitorine are three major amide alkaloids from Piper longum, showing a variety of pharmacological activities. In order to investigate the different metabolism pathways of these compounds in five species of liver microsomes in vitro, the data of full mass spectrum, and MS2, MS3 spectra of these three alkaloids were collected and analyzed by using ultra-high-performance liquid chromatography coupled with a LTQ-orbitrap mass spectrometer (UHPLC-LTQ-Orbitrap MS); gragment ion information was collected and combined with fragmentation regularities of mass spectra and accurate mass spectrometry data of metabolites, to compare the metabolism difference of three amide alkaloids in liver microsomes of human, rhesus monkey, Beagle dogs, rats and mice. 3 metabolites of piperine, 2 metabolites of piperlonguminine and 1 metabolite of pellitorine were identified quickly. The results showed that the major metabolic pathways of these amide alkaloids in liver microsomes were methylenedioxy group demethylation and oxidation reaction, and metabolic rates were different between species. This study provides basis for further research on in vivo metabolism of piperine analogues from Piper longum. Copyright© by the Chinese Pharmaceutical Association.

  20. Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes.

    Science.gov (United States)

    Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

    2014-01-21

    Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e., styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. A dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes relative to that in the wild-type mouse lung microsomes; however, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knockout and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed a susceptibility to lung toxicity of styrene similar to that of the wild-type animals; however, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene.

  1. Peroxisome proliferator activated receptor alpha regulates a male-specific cytochrome P450 in mouse liver.

    Science.gov (United States)

    Jeffery, Brett; Choudhury, Agharul I; Horley, Neill; Bruce, Mary; Tomlinson, Simon R; Roberts, Ruth A; Gray, Tim J B; Barrett, David A; Shaw, P Nicholas; Kendall, David; Bell, David R

    2004-09-15

    We set out to find if the strain-specific, male-specific hepatic expression of Cyp4a protein in mouse was due to expression of Cyp4a12 and to understand the genetic basis for reported differences in expression. 12-Lauric acid hydroxylase (LAH) activity was found to show higher levels in male ddY, but not C57Bl/6, mouse liver microsomes. The expression of Cyp4a12 mRNA was studied using RNAase protection assays in male and female liver and kidney of nine mouse strains. Cyp4a12 was found to be highly expressed in male liver and kidney, but at much lower levels in female liver and kidney, in all strains studied. Western blotting with an antibody specific for Cyp4a12 confirmed that Cyp4a12 was expressed in a male specific fashion in C57Bl/6 mouse liver. RNAase protection analysis for Cyp4a10 and 14 in ddY mice revealed that neither of these genes showed male-specific expression. To further investigate genetic factors that control male-specific Cyp4a12 expression, PPARalpha+/+ and -/- mice were studied, showing that total P450 and 12-LAH activity was male-specific in +/+, but not -/- mice. RNAase protection assays were used to confirm that Cyp4a12 was lower in -/- mice. However, the male-specific Slp and MUP-1 genes retained hepatic male-specific levels of expression in +/+ and -/- mice, showing that the decrease in Cyp4a12 was not a general effect on male-specific expression. Thus, PPARalpha has a specific effect on constitutive expression of Cyp4a12.

  2. Development of vitamin D3 25-hydroxylase activity in rat liver microsomes

    International Nuclear Information System (INIS)

    Thierry-Palmer, M.; Cullins, S.; Rashada, S.; Gray, T.K.; Free, A.

    1986-01-01

    The authors have determined the ontogeny of vitamin D 3 25-hydroxylase activity in rat liver microsomes. Microsomes from fetuses, neonates, and their mothers were incubated with 44 nM 3 H-vitamin D 3 in the presence of an NADPH generating system, oxygen, KCl, and MgCl 2 . Lipid extracts of the incubation samples were partially purified by thin-layer chromatography. Tritiated 25-hydroxy vitamin D 3 (250HD 3 ) was analyzed by high-pressure liquid chromatography using 94/6 hexane/isopropanol. Production rate for 250HD 3 in the mothers ranged from 0.22 to 0.30 pmol/mg protein/hr. Activities in the fetuses and neonates were 2.1, 12.9, 32.0, 35.8, and 71.0% of that of their mothers at -3, 0, 2, 7, and 15 days of age. The cytosolic fraction protected the substrate from degradation, stimulated the vitamin D 3 25-hydroxylase reaction in neonates and mothers (1.4 to 1.7 fold increase), and was absolutely required for 25-hydroxylase activity in fetuses. These data suggest that microsomal vitamin D 3 25-hydroxylase activity develops slowly and approaches full activity near the weaning stage. A cytosolic factor present as early as -3 days of age stimulates the activity of the microsomal vitamin D 3 25-hydroxylase

  3. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Reed, James R., E-mail: rreed@lsuhsc.edu [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Cawley, George F.; Ardoin, Taylor G. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Backes, Wayne L. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States)

    2014-06-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  4. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    International Nuclear Information System (INIS)

    Reed, James R.; Cawley, George F.; Ardoin, Taylor G.; Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W.; Backes, Wayne L.

    2014-01-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  5. [Peroxide modification of membranes and isomorphic composition of cytochrome P-450 of rat liver microsomes during antioxidant deficiency].

    Science.gov (United States)

    Gubskiy, Iu I; Paramonova, G I; Boldeskul, A E; Primak, R G; Bogdanova, L A; Zadorina, O V; Litvinova, N V

    1992-01-01

    Lipid peroxidation (LPO), physico-chemical properties of the membranes and isoformic composition of microsomal cytochrome P-450 from the rat liver were studied under conditions of antioxidant insufficiency (AOI) which was modelled by exclusion of alpha-tocopherol from the animals' ration. An insignificant accumulation of microsomal diene conjugates and schiff bases against a sharp increase of the ability to the prooxidant stimulated LPO in vitro took place. A significant decrease of membrane lipid microviscosity and a change in surface properties of microsomal membranes of rats with AOI was determined. Absence of alpha-tocopherol in the ration was accompanied by a significant change in the content of separate isoforms of cytochrome P-450 exhibited in growth of a polypeptide with m. w. 54 kDa and the lowering of proteins with m. w. 48 and 50 kDa. Less intensive quenching of tryptophan fluorescence by acrylamide was also revealed, which testified to a lower accessibility of the quencher to membrane proteins or their fluorophore sites. Modification of lipid composition and of physicochemical properties of the rat liver membrane microsomes which was observed at AOI was significantly correlated by pretreatment with the antioxidant 4-methyl-2,6-ditretbutylphenol (ionol).

  6. Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).

    Science.gov (United States)

    Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S

    2004-03-07

    The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.

  7. Hepatitis C virus infection associated with liver-kidney microsomal antibody type 1 (LKM1) autoantibodies in children.

    Science.gov (United States)

    Bortolotti, Flavia; Muratori, Luigi; Jara, Paloma; Hierro, Loreto; Verucchi, Gabriella; Giacchino, Raffaella; Barbera, Cristiana; Zancan, Lucia; Guido, Maria; Resti, Massimo; Pedditzi, Sabrina; Bianchi, Francesco; Gatta, Angelo

    2003-02-01

    To evaluate the clinical pattern and evolution of chronic hepatitis C in children with liver/kidney microsomal antibody type 1 autoantibodies (LKM1). A multicenter, retrospective study, including the following groups of children with hepatitis C virus infection: (1). 21 consecutive LKM1-positive patients, (2). 42 age- and sex- matched LKM1-negative patients, and (3). 4 interferon-induced LKM1-positive cases. LKM1 reactivity to human microsomes and recombinant cytochrome P450IID6 (CYP2D6) was assayed by immunoblotting. Clinical and biochemical features overlapped in LKM1-positive and LKM1-negative children, but a fibrosis score >3 (range 0-6) was significantly more frequent (P =.04) in the former. Reactivity to microsomal protein and CYP2D6 was significantly (P =.02) associated with LKM1 titers >or=1:320 and was found in 39% of patients, including severe cases and both children (of 4 treated) who achieved a sustained alanine aminotransferase (ALT) normalization after steroid treatment. Five of 7 LKM1-positive children treated with interferon had an ALT exacerbation. LKM1-positive hepatitis C in children is characterized by a wide spectrum of biochemical, serologic, and histologic features. Whether autoimmunity may contribute to liver damage in a subgroup of patients with more severe liver disease, high LKM1 titers, and reactivity to CYP2D6 is a question deserving further investigation.

  8. Lichen planus, liver kidney microsomal (LKM1) antibodies and hepatitis C virus antibodies.

    Science.gov (United States)

    Divano, M C; Parodi, A; Rebora, A

    1992-01-01

    No anti-liver kidney microsomal (LKM1) antibodies were detected in 46 patients with LP, 16 of whom had also a chronic liver disease (CLD). In contrast, anti-hepatitis C virus (HCV) antibodies were found in 10% of patients with LP and in 50% of those with LP and CLD. Anti-HCV antibodies may be considered as a false-positive reaction in 56% of cases, especially when anti-LKM1 antibodies are present. Our findings do not support such a hypothesis, but suggest that CLD in LP patients is, at least in Italy, mostly a postviral chronic active hepatitis.

  9. Effect of cholesterol feeding on tissue lipid perioxidation, glutathione peroxidase activity and liver microsomal functions in rats and guinea pigs

    NARCIS (Netherlands)

    TSAI, A. C.; THIE, G. M.; Lin, C. R.

    1977-01-01

    The effect of cholesterol feeding on liver and aortic nonenzymatic lipid peroxidation and glutathione peroxidase activities, and on liver microsomal NADPH-dependent lipid peroxidation, codeine hydroxylation and cytochrome P-450 levels was examined in rats and guinea pigs. One percent cholesterol was

  10. Roles of different forms of cytochrome P450 in the activation of the promutagen 6-aminochrysene to genotoxic metabolites in human liver microsomes.

    Science.gov (United States)

    Yamazaki, H; Mimura, M; Oda, Y; Inui, Y; Shiraga, T; Iwasaki, K; Guengerich, F P; Shimada, T

    1993-07-01

    We reported previously that the potent mutagen 6-aminochrysene is catalyzed principally by rat liver microsomal P4501A and P4502B enzymes to reactive metabolites that induce umu gene expression in O-acetyltransferase-over-expressing strain Salmonella typhimurium NM2009; the proposal was made that there are different mechanisms in the formation of reactive N-hydroxylated and diolepoxide metabolites by P450 enzymes (Yamazaki, H. and Shimada, T., Biochem. Pharmacol., 44, 913-920, 1992). Here we further examined the roles of human liver P450 enzymes and the mechanism of activation of 6-aminochrysene by rat and human P450 enzymes in the Salmonella tester strains. Liver microsomes from 18 different human samples catalyzed activation of 6-aminochrysene more efficiently in S. typhimurium NM2009 than in the original strain of S. typhimurium TA1535/pSK1002. The rates of 6-aminochrysene activation in 18 human liver samples showed good correlation to the contents of P4502B6 as well as contents of P4503A4 and the respective mono-oxygenase activities catalyzed by P4503A4. Among purified P450 enzymes examined, P4501A2 as well as P4503A4 were highly active in transforming 6-amino-chrysene to reactive metabolites, suggesting the involvement of different human P450 enzymes in the reaction. Four human samples that contained relatively high levels of particular P450 enzymes in their microsomes were selected and used for further characterization. Liver microsomes from human samples HL-13 and HL-4 that contained the highest levels of P4502B6 and P4503A4 respectively, were sensitive to the respective antibodies raised against monkey P4502B and human P4503A4; the activity in sample HL-16 having the highest level of P4501A2 was inhibited by anti-P4501A2 IgG. alpha-Naphthoflavone enhanced the activation of 6-aminochrysene very significantly in human liver microsomes enriched in P4503A4 and P4502B6 enzymes. Pentachlorophenol, an inhibitor of acetyltransferase activity, suppressed the

  11. 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

  12. Characterization of anti-liver-kidney microsome antibody (anti-LKM1) from hepatitis C virus-positive and -negative sera.

    Science.gov (United States)

    Yamamoto, A M; Cresteil, D; Homberg, J C; Alvarez, F

    1993-06-01

    Hepatitis C virus-related antibodies were found in sera positive for antibodies to liver/kidney microsome antibody, usually considered a marker of autoimmune hepatitis. The aim of this study was to analyze the specificity of this autoantibody in sera from patients with and without hepatitis C virus infection. Fifteen anti-hepatitis C virus- and anti-liver kidney microsome-positive sera were compared with 11 sera from patients with autoimmune hepatitis, for reactivity against rat and human liver microsomal proteins, P450IID6 recombinant proteins, and various synthetic peptides spanning the 241-429 amino acids sequence of the P450IID6. Ten of 11 sera from patients with autoimmune hepatitis bound to recombinant proteins spanning the P450IID6 region between amino acids 72 and 458. These sera bound to the 254-271 peptide, and some also recognized the 321-351, 373-389 and 410-429 peptides. Four of 15 antihepatitis C virus recognized the fusion protein coded by the full-length P450IID6 complementary DNA; 3 of them also reacted with the P450IID6 region between amino acids 72-456. Only 1 sera recognized the 321-351 peptide. P450IID6 antigenic sites recognized by anti-hepatitis C virus-positive sera were different from those recognized by sera from patients with autoimmune hepatitis.

  13. Role of metabolic activation by cytochrome P-450 in covalent binding of VP 16-213 to rat liver and HeLa cell microsomal proteins

    Energy Technology Data Exchange (ETDEWEB)

    van Maanen, J.M.; de Ruiter, C.; de Vries, J.; Kootstra, P.R.; Gobas, F.; Pinedo, H.M.

    1985-09-01

    Covalent binding of /sup 3/H-labeled VP 16-213 to rat liver and HeLa cell microsomal proteins was studied in vitro. Metabolic activation by cytochrome P-450 was found to play a role in the covalent binding of VP 16-213 to rat liver microsomal proteins, as shown by the need of NADPH cofactor, the increased binding after phenobarbital pretreatment and the inhibition by SFK-525A. Addition of ascorbic acid or alpha-phenyl-N-tert. butylnitrone to the incubation mixture depressed covalent binding by about 85%, suggesting that formation of a reactive metabolite from the phenolic structure may be involved in the binding process. VP 16-213 did not inhibit aminopyrine N-demethylase at the concentration used in the binding experiments (17 microM), indicating that metabolism of its methylenedioxy group does not play a role in binding to microsomal proteins. HeLa cell microsomes were found to possess aminopyrine N-demethylase activity. Covalent binding of radiolabeled VP 16-213 to HeLa cell microsomes decreased by about 64% if NADPH was omitted.

  14. Microsomal metabolism of trenbolone acetate metabolites ...

    Science.gov (United States)

    Trenbolone acetate (TBA) is a synthetic growth promoter widely used in animal agriculture, and its metabolites are suspected endocrine disrupting compounds in agriculturally impacted receiving waters. However, beyond the three widely recognized TBA metabolites (17-trenbolone, 17-trenbolone and trendione), little is known about other metabolites formed in vivo and subsequently discharged into the environment, with some evidence suggesting these unknown metabolites comprise a majority of the TBA mass dosed to the animal. Here, we explored the metabolism of the three known TBA metabolites using rat liver microsome studies. All TBA metabolites are transformed into a complex mixture of monohydroxylated products. Based on product characterization, the majority are more polar than the parent metabolites but maintain their characteristic trienone backbone. A minor degree of interconversion between known metabolites was also observed, as were higher order hydroxylated products with a greater extent of reaction. Notably, the distribution and yield of products were generally comparable across a series of variably induced rat liver microsomes, as well as during additional studies with human and bovine liver microsomes. Bioassays conducted with mixtures of these transformation products suggest that androgen receptor (AR) binding activity is diminished as a result of the microsomal treatment, suggesting that the transformation products are generally less potent than

  15. Rat liver microsomal cytochrome P450-dependent oxidation of 3,5-disubstituted analogues of paracetamol

    NARCIS (Netherlands)

    Bessems, J.G.M.; Koppele, J.M. te; Dijk, P.A. van; Stee, L.L.P. van; Commandeur, J.N.M.; Vermeulen, N.P.E.

    1996-01-01

    1. The cytochrome P450-dependent binding of paracetamol and a series of 3,5-disubstituted paracetamol analogues (R = -F, -Cl, -Br, -I, -C(H)3, -C2H5, -iC3H7) have been determined with β-naphthoflavone (βNF)-induced rat liver microsomes and produced reverse type I spectral changes. K(s,app) varied

  16. Glucuronidation of trans-resveratrol by human liver and intestinal microsomes and UGT isoforms.

    Science.gov (United States)

    Brill, Shirley S; Furimsky, Anna M; Ho, Mark N; Furniss, Michael J; Li, Yi; Green, Adam G; Bradford, Wallace W; Green, Carol E; Kapetanovic, Izet M; Iyer, Lalitha V

    2006-04-01

    Resveratrol (trans-resveratrol, trans-3,5,4'-trihydroxystilbene) is a naturally occurring stilbene analogue found in high concentrations in red wine. There is considerable research interest to determine the therapeutic potential of resveratrol, as it has been shown to have tumour inhibitory and antioxidant properties. This study was performed to investigate the glucuronidation of resveratrol and possible drug interactions via glucuronidation. Two glucuronide conjugates, resveratrol 3-O-glucuronide and resveratrol 4'-O-glucuronide, were formed by human liver and intestinal microsomes. UGT1A1 and UGT1A9 were predominantly responsible for the formation of the 3-O-glucuronide (Km = 149 microM) and 4'-O-glucuronide (Km = 365 microM), respectively. The glucuronide conjugates were formed at higher levels (up to 10-fold) by intestinal rather than liver microsomes. Resveratrol was co-incubated with substrates of UGT1A1 (bilirubin and 7-ethyl-10-hydroxycamptothecin (SN-38)) and UGT1A9 (7-hydroxytrifluoromethyl coumarin (7-HFC)). No major changes were noted in bilirubin glucuronidation in the presence of resveratrol. Resveratrol significantly inhibited the glucuronidation of SN-38 (Ki = 6.2 +/- 2.1 microM) and 7-HFC (Ki = 0.6 +/- 0.2 microM). Hence, resveratrol has the potential to inhibit the glucuronidation of concomitantly administered therapeutic drugs or dietary components that are substrates of UGT1A1 and UGT1A9.

  17. Age dependent in vitro metabolism of bifenthrin in rat and human hepatic microsomes.

    Science.gov (United States)

    Nallani, Gopinath C; Chandrasekaran, Appavu; Kassahun, Kelem; Shen, Li; ElNaggar, Shaaban F; Liu, Zhiwei

    2018-01-01

    Bifenthrin, a pyrethroid insecticide, undergoes oxidative metabolism leading to the formation of 4'-hydroxy-bifenthrin (4'-OH-BIF) and hydrolysis leading to the formation of TFP acid in rat and human hepatic microsomes. In this study, age-dependent metabolism of bifenthrin in rats and humans were determined via the rates of formation of 4'-OH-BIF and TFP acid following incubation of bifenthrin in juvenile and adult rat (PND 15 and PND 90) and human (18years) liver microsomes. Furthermore, in vitro hepatic intrinsic clearance (CL int ) of bifenthrin was determined by substrate consumption method in a separate experiment. The mean V max (±SD) for the formation of 4'-OH-BIF in juvenile rat hepatic microsomes was 25.0±1.5pmol/min/mg which was significantly lower (pbifenthrin occurs primarily via oxidative pathway with relatively lesser contribution (~30%) from hydrolytic pathway in both rat and human liver microsomes. The CL int values for bifenthrin, determined by monitoring the consumption of substrate, in juvenile and adult rat liver microsomes fortified with NADPH were 42.0±7.2 and 166.7±20.5μl/min/mg, respectively, and the corresponding values for human liver microsomes were 76.0±4.0 and 21.3±1.2μl/min/mg, respectively. The data suggest a major species difference in the age dependent metabolism of bifenthrin. In human liver microsomes, bifenthrin is metabolized at a much higher rate in juveniles than in adults, while the opposite appears to be true in rat liver microsomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. An update on the mouse liver proteome

    Directory of Open Access Journals (Sweden)

    Borlak Jürgen

    2009-09-01

    Full Text Available Abstract Background Decoding of the liver proteome is subject of intense research, but hampered by methodological constraints. We recently developed an improved protocol for studying rat liver proteins based on 2-DE-MALDI-TOF-MS peptide mass finger printing. This methodology was now applied to develop a mouse liver protein database. Results Liver proteins were extracted by two different lysis buffers in sequence followed by a liquid-phase IEF pre-fractionation and separation of proteins by 2 DE at two different pH ranges, notably 5-8 and 7-10. Based on 9600 in gel digests a total of 643 mouse liver proteins with high sequence coverage (> 20 peptides per protein could be identified by MALDI-TOF-MS peptide mass finger printing. Notably, 255 proteins are novel and have not been reported so far by conventional two-dimensional electrophoresis proteome mapping. Additionally, the results of the present findings for mouse liver were compared to published data of the rat proteome to compile as many proteins as possible in a rodent liver database. Conclusion Based on 2-DE MALDI-TOF-MS a significantly improved proteome map of mouse liver was obtained. We discuss some prominent members of newly identified proteins for a better understanding of liver biology.

  19. Hepatic mitochondrial and microsomal recovery of rats intoxicated with CCl/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, T.; Hirai, Y.; Koga, N.; Tomokuni, K.

    1983-01-01

    The hepatic mitochondrial and microsomal recovery of rats intoxicated with CCl/sub 4/ was investigated with specific reference to the oxygen utilization of liver slices. In control rats, the major oxygen utilization of the liver slices was attributed to mitochondrial particles. Since the mitochondrial oxygen utilization was inhibited by cyanide, the microsomal oxygen utilization was induced by NADPH and phenobarbital (a substrate for microsomal mixed function oxidase). Changes in oxygen utilization were observed in the recovery course of rats intoxicated with CCl/sub 4/, and the recovery of mitochondria was found to be faster than that of microsomes. A sex difference was present in the recovery mechanism of the microsomes.

  20. Stereoselective formation of a cholesterol ester conjugate from fenvalerate by mouse microsomal carboxyesterase(s).

    Science.gov (United States)

    Miyamoto, J; Kaneko, H; Takamatsu, Y

    1986-06-01

    In accordance with in vivo findings, of the four chiral isomers of fenvalerate (S-5602 Sumicidin, Pydrin, [RS]-alpha-cyano-3-phenoxybenzyl [RS]-2-(4-chlorophenyl)isovalerate), only the [2R, alpha S]-isomer (B-isomer) yielded cholesteryl [2R]-2-(4-chlorophenyl)isovalerate (CPIA-cholesterol ester) in the in vitro study using several tissue homogenates of mice, rats, dogs, and monkeys. There were species differences in the extent of CPIA-cholesterol-ester formation, with mouse tissues showing relatively higher activity than those of other animals. The kidney, brain, and spleen of mice showed relatively higher capacities to form this ester compared to other tissues, and the enzyme activity was mainly localized in microsomal fractions. The CPIA-cholesterol ester did not seem to be produced by three known biosynthetic pathways of endogenous cholesterol esters--acyl-CoA:cholesterol O-acyltransferase (ACAT), lecithin:cholesterol O-acyltransferase (LCAT), and cholesterol esterase. Carboxyesterase(s) of mouse kidney microsomes solubilized by digitonin hydrolyzed only the B alpha-isomer of fenvalerate, yielding CPIA, whereas they yielded the corresponding cholesterol ester in the presence of artificial liposomes containing cholesterol. Thus, it appears that the stereoselective formation of the CPIA-cholesterol ester results from the stereoselective formation of the CPIA-carboxyesterase complex only from the B alpha-isomer, which subsequently undergoes cleavage by cholesterol to yield the CPIA-cholesterol ester.

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

    OpenAIRE

    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 confo...

  2. Inhibitory Effects of Dimethyllirioresinol, Epimagnolin A, Eudesmin, Fargesin, and Magnolin on Cytochrome P450 Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Ju-Hyun Kim

    2017-05-01

    Full Text Available Magnolin, epimagnolin A, dimethyllirioresinol, eudesmin, and fargesin are pharmacologically active tetrahydrofurofuranoid lignans found in Flos Magnoliae. The inhibitory potentials of dimethyllirioresinol, epimagnolin A, eudesmin, fargesin, and magnolin on eight major human cytochrome P450 (CYP enzyme activities in human liver microsomes were evaluated using liquid chromatography–tandem mass spectrometry to determine the inhibition mechanisms and inhibition potency. Fargesin inhibited CYP2C9-catalyzed diclofenac 4’-hydroxylation with a Ki value of 16.3 μM, and it exhibited mechanism-based inhibition of CYP2C19-catalyzed [S]-mephenytoin 4’-hydroxylation (Ki, 3.7 μM; kinact, 0.102 min−1, CYP2C8-catalyzed amodiaquine N-deethylation (Ki, 10.7 μM; kinact, 0.082 min−1, and CYP3A4-catalyzed midazolam 1’-hydroxylation (Ki, 23.0 μM; kinact, 0.050 min−1 in human liver microsomes. Fargesin negligibly inhibited CYP1A2-catalyzed phenacetin O-deethylation, CYP2A6-catalyzed coumarin 7-hydroxylation, CYP2B6-catalyzed bupropion hydroxylation, and CYP2D6-catalyzed bufuralol 1’-hydroxylation at 100 μM in human liver microsomes. Dimethyllirioresinol weakly inhibited CYP2C19 and CYP2C8 with IC50 values of 55.1 and 85.0 μM, respectively, without inhibition of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, and CYP3A4 activities at 100 μM. Epimagnolin A, eudesmin, and magnolin showed no the reversible and time-dependent inhibition of eight major CYP activities at 100 μM in human liver microsomes. These in vitro results suggest that it is necessary to investigate the potentials of in vivo fargesin-drug interaction with CYP2C8, CYP2C9, CYP2C19, and CYP3A4 substrates.

  3. Isolation and structural elucidation of tiamulin metabolites formed in liver microsomes of pigs

    DEFF Research Database (Denmark)

    Lykkeberg, Anne Kruse; Cornett, Claus; Halling-Sørensen, Bent

    2006-01-01

    Although the antimicrobial tiamulin is extensively metabolized in pigs, the metabolism is not well investigated. In this work the NADPH dependent metabolism of tiamulin in liver microsomes from pigs has been studied. The tiamulin metabolites formed in the incubations were analysed using LC-MS, an...... 20% of tiamulin was deethylated, 10% was hydroxylated in the 2beta-position and 7% was hydroxylated in the 8alpha-position. About 40% of tiamulin was metabolized during the incubation conditions used. The protein precipitation in the incubations was performed using perchloric acid...

  4. Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

    Directory of Open Access Journals (Sweden)

    Menéndez R.

    2000-01-01

    Full Text Available The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS. When D002 (5-100 mg/kg body weight was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46% occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40% and brain (28-44% microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans.

  5. In vitro modulatory effects of Terminalia arjuna, arjunic acid, arjunetin and arjungenin on CYP3A4, CYP2D6 and CYP2C9 enzyme activity in human liver microsomes

    Directory of Open Access Journals (Sweden)

    Alice Varghese

    2015-01-01

    Full Text Available Terminalia arjuna is a tree having an extensive medicinal potential in cardiovascular disorders. Triterpenoids are mainly responsible for cardiovascular properties. Alcoholic and aqueous bark extracts of T. arjuna, arjunic acid, arjunetin and arjungenin were evaluated for their potential to inhibit CYP3A4, CYP2D6 and CYP2C9 enzymes in human liver microsomes. We have demonstrated that alcoholic and aqueous bark extract of T. arjuna showed potent inhibition of all three enzymes in human liver microsomes with IC50 values less than 50 μg/mL. Arjunic acid, arjunetin and arjungenin did not show significant inhibition of CYP enzymes in human liver microsomes. Enzyme kinetics studies suggested that the extracts of arjuna showed reversible non-competitive inhibition of all the three enzymes in human liver microsomes. Our findings suggest strongly that arjuna extracts significantly inhibit the activity of CYP3A4, CYP2D6 and CYP2C9 enzymes, which is likely to cause clinically significant drug–drug interactions mediated via inhibition of the major CYP isozymes.

  6. Hepatic microsomal metabolism of BDE-47 and BDE-99 by lesser snow geese and Japanese quail.

    Science.gov (United States)

    Krieger, Lisa K; Szeitz, András; Bandiera, Stelvio M

    2017-09-01

    In the present study, we investigated the oxidative biotransformation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) by liver microsomes from wild lesser snow geese (Chen caerulescens caerulescens) and domesticated Japanese quail (Coturnix japonica). Formation of hydroxy-metabolites was analyzed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with avian liver microsomes produced sixteen hydroxy-metabolites, eight of which were identified using authentic standards. The major metabolites formed by liver microsomes from individual lesser snow geese were 4-hydroxy-2,2',3,4'-tetrabromodiphenyl ether (4-OH-BDE-42), 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47), and 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether (4'-OH-BDE-49). By comparison, 4-OH-BDE-42 and 4'-OH-BDE-49, but not 3-OH-BDE-47, were major metabolites of Japanese quail liver microsomes. Unidentified metabolites included monohydroxy- and dihydroxy-tetrabromodiphenyl ethers. Incubation of BDE-99 with avian liver microsomes produced seventeen hydroxy-metabolites, twelve of which were identified using authentic standards. The major metabolites formed by lesser snow goose liver microsomes were 2,4,5-tribromophenol, 3-OH-BDE-47, 4'-OH-BDE-49, 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether (4-OH-BDE-90), and 5'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99). By comparison, the major metabolites produced by liver microsomes from Japanese quail included 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) and 2-hydroxy-2',3,4,4',5-pentabromodiphenyl ether (2-OH-BDE-123), but not 3-OH-BDE-47. Unidentified metabolites consisted of monohydroxy-pentabromodiphenyl ethers, monohydroxy-tetrabromodiphenyl ethers and dihydroxy-tetrabromodiphenyl ethers. Another difference between the two species was that formation rates of BDE-47 and BDE-99 metabolites were greater with liver

  7. Liver Transplantation in the Mouse: Insights Into Liver Immunobiology, Tissue Injury and Allograft Tolerance

    Science.gov (United States)

    Yokota, Shinichiro; Yoshida, Osamu; Ono, Yoshihiro; Geller, David A.; Thomson, Angus W.

    2016-01-01

    The surgically-demanding mouse orthotopic liver transplant model was first described in 1991. It has proved a powerful research tool for investigation of liver biology, tissue injury, the regulation of alloimmunity and tolerance induction and the pathogenesis of specific liver diseases. Liver transplantation in mice has unique advantages over transplantation of the liver in larger species, such as the rat or pig, since the mouse genome is well-characterized and there is much greater availability of both genetically-modified animals and research reagents. Liver transplant experiments using various transgenic or gene knockout mice has provided valuable mechanistic insights into the immuno- and pathobiology of the liver and the regulation of graft rejection and tolerance over the past 25 years. The molecular pathways identified in regulation of tissue injury and promotion of liver transplant tolerance provide new potential targets for therapeutic intervention to control adverse inflammatory responses/ immune-mediated events in the hepatic environment and systemically. Conclusion: Orthotopic liver transplantation in the mouse is a valuable model for gaining improved insights into liver biology, immunopathology and allograft tolerance that may result in therapeutic innovation in liver and other diseases. PMID:26709949

  8. 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

  9. Dietary saturated and monounsaturated fats protect against acute acetaminophen hepatotoxicity by altering fatty acid composition of liver microsomal membrane in rats

    Directory of Open Access Journals (Sweden)

    Shim Eugene

    2011-10-01

    Full Text Available Abstract Background Dietary polyunsaturated fats increase liver injury in response to ethanol feeding. We evaluated the effect of dietary corn oil (CO, olive oil (OO, and beef tallow (BT on fatty acid composition of liver microsomal membrane and acute acetaminophen hepatotoxicity. Methods Male Sprague-Dawley rats were fed 15% (wt/wt CO, OO or BT for 6 weeks. After treatment with acetaminophen (600 mg/kg, samples of plasma and liver were taken for analyses of the fatty acid composition and toxicity. Results Treatment with acetaminophen significantly elevated levels of plasma GOT and GPT as well as hepatic TBARS but reduced hepatic GSH levels in CO compared to OO and BT groups. Acetaminophen significantly induced protein expression of cytochrome P450 2E1 in the CO group. In comparison with the CO diet, lower levels of linoleic acid, higher levels of oleic acids and therefore much lower ratios of linoleic to oleic acid were detected in rats fed OO and BT diets. Conclusions Dietary OO and BT produces similar liver microsomal fatty acid composition and may account for less severe liver injury after acetaminophen treatment compared to animals fed diets with CO rich in linoleic acid. These findings imply that types of dietary fat may be important in the nutritional management of drug-induced hepatotoxicity.

  10. In vitro metabolism of the anti-androgenic fungicide vinclozolin by rat liver microsomes.

    Science.gov (United States)

    Sierra-Santoyo, Adolfo; Angeles-Soto, Esperanza; de Lourdes López-González, Ma; Harrison, Randy A; Hughes, Michael F

    2012-03-01

    Vinclozolin (V) is a fungicide used in agricultural settings. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1) and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2). V, M1 and M2 have antiandrogenic properties by interacting with the androgen receptor. Data on V, M1 and M2 biotransformation are limited. Our objective was to characterize V metabolism by rat liver microsomes. V was incubated with non-treated adult male Long-Evans rat liver microsomes and NADPH. Several metabolites were detected following the extraction of incubate with acetonitrile and analysis by HPLC/DAD/MSD. One metabolite was identified as [3-(3,5-dichlorophenyl)-5-methyl-5-(1,2-dihydroxyethyl)-1,3-oxazolidine-2,4-dione] (M4), which was gradually converted to 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (M5). Both co-eluted in the same HPLC peak. Another metabolite ([M7]) was detected by UV but was unstable for mass spectral analysis. The K(M app) for co-eluted M4/M5 and [M7] was 53.7 and 135.4 μM, the V(max app) was 0.812 and 0.669 nmoles/min/mg protein, and CL(int) was 15.1 and 4.9 ml/min/g protein, respectively. Pilocarpine, orphenadrine and proadifen and anti-rat cytochrome P450 (CYP)2A, 2B and 3A antibodies inhibited M4/M5 and [M7] formation. These results indicate that V is efficiently metabolized by CYP. Determination of the metabolites of V will provide further insight into the relationship between toxicity and tissue dose of V and its metabolites.

  11. Influence of whole body irradiation on induction of the hepatic microsomal system metabolizing drugs

    International Nuclear Information System (INIS)

    Szyszko, A.; Bitny-Szlachto, S.

    1977-01-01

    Effects of whole body irradiation (600 R) on rat liver aminophenazone demethylase activities of the liver homogenate 10,000 X g supernatant and its microsomal fraction were compared. Either activities were found to be decreased by irradiation by some 35%. The phenobarbital treatment (3 x 100 mg/kg i.p.) has turned out to provide higher relative augmentation of the liver demethylase activity in irradiated than in unirradiated rats. The cytoplasmic activity was found to be augmented by phenobarbital treatment 2,21-fold in unirradiated, and 3,20-fold in irradiated rats, and the microsomal activity increased 3,28-fold and 3,77-fold, respectively. Microsomal levels of cytochrome P-450 were found to be not affected by irradiation. (author)

  12. Activation of farnesoid X receptor induces RECK expression in mouse liver

    International Nuclear Information System (INIS)

    Peng, Xiaomin; Wu, Weibin; Zhu, Bo; Sun, Zhichao; Ji, Lingling; Ruan, Yuanyuan; Zhou, Meiling; Zhou, Lei; Gu, Jianxin

    2014-01-01

    Highlights: •RECK is a novel transcriptional target gene of FXR in mouse liver. •The FXR response element is located within the intron 1 of RECK gene. •FXR agonist reverses the down-regulation of RECK in the liver in mouse NASH model. -- Abstract: Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver

  13. Activation of farnesoid X receptor induces RECK expression in mouse liver

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Xiaomin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Wu, Weibin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China); Zhu, Bo; Sun, Zhichao; Ji, Lingling; Ruan, Yuanyuan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Zhou, Lei, E-mail: yhchloech@gmail.com [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Sciences, Fudan University, Shanghai 200032 (China)

    2014-01-03

    Highlights: •RECK is a novel transcriptional target gene of FXR in mouse liver. •The FXR response element is located within the intron 1 of RECK gene. •FXR agonist reverses the down-regulation of RECK in the liver in mouse NASH model. -- Abstract: Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver.

  14. A novel assay for detecting antibodies to cytochrome P4502D6, the molecular target of liver kidney microsomal antibody type 1.

    Science.gov (United States)

    Kerkar, N; Ma, Y; Hussain, M; Muratori, L; Targett, C; Williams, R; Bianchi, F B; Mieli-Vergani, G; Vergani, D

    1999-03-04

    Liver Kidney Microsomal type 1 (LKM1) antibody, the diagnostic marker of autoimmune hepatitis type 2, is also found in a proportion of patients with hepatitis C virus infection (HCV). It is detected conventionally by the subjective immunofluorescence technique. Our aim was to establish a simple and objective enzyme-linked immunosorbent assay (ELISA) that measures antibodies to cytochrome P4502D6 (CYP2D6), the target of LKM1. An indirect ELISA using eukaryotically expressed CYP2D6 was designed. Absorbance values obtained against a reference microsomal preparation were subtracted from those obtained against a microsomal preparation over-expressing CYP2D6, thus removing the non-CYP2D6-specific reaction. Sera from 51 LKM1 positive patients (21 autoimmune hepatitis and 30 with HCV infection), 111 LKM1 negative patients with chronic liver disease (including 20 with HCV infection) and 43 healthy controls were tested. Of 51 patients positive by immunofluorescence, 48 were also positive by ELISA while all the 154 LKM1 negative subjects were also negative by ELISA. There was a high degree of association between IFL and ELISA as demonstrated by a kappa reliability value of 0.96. The absorbance values by ELISA correlated with immunofluorescence LKM1 titres both in autoimmune hepatitis (r = 0.74, p < 0.001) and HCV infection (r = 0.67, p < 0.001). The simple, objective ELISA described has the potential to replace the standard immunofluorescence technique.

  15. Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

    Science.gov (United States)

    Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

    1989-03-15

    Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

  16. Transcriptomic profiling of trichloroethylene exposure in male mouse liver

    Directory of Open Access Journals (Sweden)

    Yan Jiang

    2015-03-01

    Full Text Available Chronic Trichloroethylene (TCE exposure could induce hepatocellular carcinoma in mice, and occupational exposure in humans was suggested to be associated with liver cancer. To understand the role of non-genotoxic mechanism(s for TCE action, we examined the gene expression and DNA methylation changes in the liver of B6C3F1 mice orally administered with TCE for 5 days. As a beginning step, we profiled gene expression alterations induced by the TCE in mouse livers. Here we describe in detail the experimental methods, quality controls, and other information associated with our data deposited into Gene Expression Omnibus (GEO under GSE58819. Our data provide useful information for gene expression responses to TCE in mouse liver.

  17. Age dependence of rat liver function measurements

    DEFF Research Database (Denmark)

    Fischer-Nielsen, A; Poulsen, H E; Hansen, B A

    1989-01-01

    Changes in the galactose elimination capacity, the capacity of urea-N synthesis and antipyrine clearance were studied in male Wistar rats at the age of 8, 20 and 44 weeks. Further, liver tissue concentrations of microsomal cytochrome P-450, microsomal protein and glutathione were measured. All...... liver function measurements increased from the age of 8 to 44 weeks when expressed in absolute values. In relation to body weight, these function measurements were unchanged or reduced from week 8 to week 20. At week 44, galactose elimination capacity and capacity of urea-N synthesis related to body...... weight were increased by 10% and 36%, respectively, and antipyrine plasma clearance was reduced to 50%. Liver tissue concentrations of microsomal cytochrome P-450 and microsomal protein increased with age when expressed in absolute values, but were unchanged per g liver, i.e., closely related to liver...

  18. Comparison of epoxide and free-radical mechanisms for activation of benzo[a]pyrene by Sprague-Dawley rat liver microsomes

    International Nuclear Information System (INIS)

    Selkirk, J.K.

    1980-01-01

    Coincubation of [6- 3 H]benzo[a]pyrene ([6- 3 H]BP) and [ 14 C]BP with SD rat liver microsomes produced metabolic profiles that showed that the C-6 of BP was not affected by formation of 4,5-dihydro-4,5-dihydroxy-BP, 7,8-dihydro-7,8-dihydroxy-BP, and 9,10-dihydro-9,10-dihydroxy-BP nor the 3- and 9-phenols of BP. Complete retention of tritium at C-6, except in the three quinones, confirmed the radical-cation model for formation of the 6-oxo-radical followed by oxidation to quinone. Epoxide formation at the carcinogenically active regions of BP appeared to biochemically isolate from 6-position activation and suggested that the microsomal epoxide pathway is unrelated to the radicalcation scheme. These molar ratios derived from double-label experiments reinforced the current literature that indicates the epoxide mechanism as the major pathway toward carcinogenic forms of BP

  19. Determination of the 4-monohydroxy metabolites of perhexiline in human plasma, urine and liver microsomes by liquid chromatography.

    Science.gov (United States)

    Davies, Benjamin J; Herbert, Megan K; Coller, Janet K; Somogyi, Andrew A; Milne, Robert W; Sallustio, Benedetta C

    2006-11-07

    The use of perhexiline (PHX) is limited by hepatic and neurological toxicity associated with elevated concentrations in plasma that are the result of polymorphism of the cytochrome P450 2D6 isoform (CYP2D6). PHX is cleared by hepatic oxidation that produces three 4-monohydroxy metabolites: cis-OH-PHX, trans1-OH-PHX and trans2-OH-PHX. The current study describes an HPLC-fluorescent method utilising pre-column derivatization with dansyl chloride. Following derivatization, the metabolites were resolved on a C18 column with a gradient elution using a mobile phase composed of methanol and water. The method described is suitable for the quantification of the metabolites in human plasma and urine following clinical doses and for kinetic studies using human liver microsomes. The method demonstrates sufficient sensitivity, accuracy and precision between 5.0 and 0.01, 50.0 and 0.2 and 1.0 and 0.005 mg/l in human plasma, urine and liver microsomes, respectively, with intra-assay coefficients of variation and bias D6 extensive metaboliser (EM) patients at steady state with respect to PHX dosing determined that the mean (+/-S.D.) renal clearances of trans1-OH-PHX and cis-OH-PHX were 1.58+/-0.35 and 0.16+/-0.06l/h, respectively. The mean (+/-S.D.) dose recovered in urine as free and glucuronidated 4-monohydroxy PHX metabolites was 20.6+/-11.6%.

  20. Metabolic activation of 2-methylfuran by rat microsomal systems

    International Nuclear Information System (INIS)

    Ravindranath, V.; Boyd, M.R.

    1985-01-01

    2-Methylfuran (2-MF), a constituent of cigarette smoke and coffee, causes necrosis of liver, lungs, and kidneys in rodents. 2-MF is metabolically activated by mixed-function oxidases to acetylacrolein, a reactive metabolite that binds covalently to microsomal protein. The hepatic microsomal metabolism of 2-MF to reactive metabolite required the presence of NADPH and oxygen and was dependent on incubation time and substrate concentration. The microsomal metabolism of 2-MF was inducible by pretreatment of rats with phenobarbital and was inhibited by piperonyl butoxide and N-octyl imidazole, which indicates that the metabolism of 2-MF may be mediated by cytochrome P-450. Acetylacrolein was a potent inhibitor of mixed-function oxidase and completely inhibited the microsomal metabolism of 2-MF, indicating that 2-MF is a suicide substrate for the enzyme. The sulfhydryl nucleophile cysteine was a better trapping agent of the reactive metabolite of 2-MF than N-acetylcysteine or glutathione. Lysine decreased the covalent binding of 2-MF metabolites, presumably by reacting with the aldehyde group of acetylacrolein. In addition, in the presence of NADPH, 2-MF was bioactivated by both pulmonary and renal cortical microsomes to reactive metabolites that were covalently bound to microsomal proteins

  1. Distinct ontogenic patterns of overt and latent DGAT activities of rat liver microsomes.

    Science.gov (United States)

    Waterman, Ian J; Price, Nigel T; Zammit, Victor A

    2002-09-01

    We have studied the ontogeny of the two functional diacylglycerol acyltransferase (DGAT) activities (overt and latent) during postnatal development in rat liver. We find that the ontogenic patterns of the two are highly distinct. Overt DGAT shows a transient rise in activity up to day 4 postnatally, after which it declines until weaning; thereafter, it increases steadily to reach high adult values that may contribute to the high rates of turnover of cytosolic triacylglycerol (TAG). By contrast, latent DGAT activity increases continuously during the suckling period but falls sharply upon weaning onto chow but not onto a high-fat diet. Rates of TAG secretion by hepatocytes are higher than in the adult during the first 7 days after birth, and are largely dependent on the mobilization of the abundant intrahepatocyte TAG as a source of acyl moieties. When the hepatic steatosis is cleared (after day 7) the TAG secretion rate declines by 80% to reach adult values. Quantification of the content of mRNA for the DGAT1 and DGAT2 genes does not show correlation with either of the DGAT activities. We conclude that post-translational modification may play an important role in the overt and latent distribution of DGAT activity in the liver microsomal membrane.

  2. The rabbit liver microsomal biotransformation of 1,1-dialkylethylenes: enantioface selection of epoxidation and enantioselectivity of epoxide hydrolysis.

    Science.gov (United States)

    Bellucci, G; Chiappe, C; Cordoni, A; Marioni, F

    1994-01-01

    The rabbit liver microsomal biotransformation of alpha-methylstyrene (1a), 2-methyl-1-hexene (1b), 2,4,4-trimethyl-1-pentene (1c), and 1,3,3-trimethyl-1-butene (1d) has been investigated with the aim at establishing the enantioface selection of the cytochrome P-450-promoted epoxidation of the double bond and the enantioselectivity of microsomal epoxide hydrolase(mEH)-catalyzed hydrolysis of the resulting epoxides. GLC on a Chiraldex G-TA (ASTEC) column was used to determine the enantiomeric composition of the products. The epoxides 2 first produced in incubations carried out in the presence of an NADPH regenerating system were not detected, being rapidly hydrolyzed by mEH to diols 3. The enantiomeric composition of the latter showed that no enantioface selection occurred in the epoxidation of 1c and 1d, and a very low (8%) ee of the (R)-epoxide was formed from 1b. Incubation of racemic epoxides 2b-d with the microsomal fraction showed that the mEH-catalyzed hydrolysis of 2c and 2d was practically nonenantioselective, while that of 2b exhibited a selectivity E = 4.9 favoring the hydrolysis of the (S)-enantiomer. A comparison of these results with those previously obtained for linear and branched chain alkyl monosubstituted oxiranes shows that the introduction of the second alkyl substituent suppresses the selectivity of the mEH reaction of the latter and reverses that of the former substrates.

  3. Microsomal lipid peroxidation as a mechanism of cellular damage. [Dissertation

    Energy Technology Data Exchange (ETDEWEB)

    Kornbrust, D.J.

    1979-01-01

    The NADPH/iron-dependent peroxidation of lipids in rat liver microsomes was found to be dependent on the presence of free ferrous ion and maintains iron in the reduced Fe/sup 2 +/ state. Chelation of iron by EDTA inhibited peroxidation. Addition of iron, after preincubation of microsomes in the absence of iron, did not enhance the rate of peroxidation suggesting that iron acts by initiating peroxidative decomposition of membrane lipids rather than by catalyzing the breakdown of pre-formed hydroperoxides. Liposomes also underwent peroxidation in the presence of ferrous iron at a rate comparable to intact microsomes and was stimulated by ascorbate. Carbon tetrachloride initiated lipid peroxidation in the absence of free metal ions. Rates of in vitro lipid peroxidation of microsomes and homogenates were found to vary widely between different tissues and species. The effects of paraquat on lipid peroxidation was also studied. (DC)

  4. UDP-Glucuronosyltransferase Expression in Mouse Liver Is Increased in Obesity- and Fasting-Induced Steatosis

    Science.gov (United States)

    Xu, Jialin; Kulkarni, Supriya R.; Li, Liya

    2012-01-01

    UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lepob/ob (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance. PMID:22031624

  5. UDP-glucuronosyltransferase expression in mouse liver is increased in obesity- and fasting-induced steatosis.

    Science.gov (United States)

    Xu, Jialin; Kulkarni, Supriya R; Li, Liya; Slitt, Angela L

    2012-02-01

    UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lep(ob/ob) (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance.

  6. Effects of thiol antioxidants on the atropselective oxidation of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) by rat liver microsomes.

    Science.gov (United States)

    Wu, Xianai; Lehmler, Hans-Joachim

    2016-02-01

    Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0-10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol), 4-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol), and 4,5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136, and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo.

  7. Isolation of Kupffer Cells and Hepatocytes from a Single Mouse Liver

    DEFF Research Database (Denmark)

    Aparicio-Vergara, Marcela; Tencerova, Michaela; Morgantini, Cecilia

    2017-01-01

    Liver perfusion is a common technique used to isolate parenchymal and non-parenchymal liver cells for in vitro experiments. This method allows hepatic cells to be separated based on their size and weight, by centrifugation using a density gradient. To date, other methods allow the isolation of only...... one viable hepatic cellular fraction from a single mouse; either parenchymal (hepatocytes) or non-parenchymal cells (i.e., Kupffer cells or hepatic stellate cells). Here, we describe a method to isolate both hepatocytes and Kupffer cells from a single mouse liver, thereby providing the unique...... advantage of studying different liver cell types that have been isolated from the same organism....

  8. Influence of sex hormones on relative quantities of multiple species of cytochrome P-450 in rat liver microsomes

    International Nuclear Information System (INIS)

    Fujita, S.; Peisach, J.; Chevion, M.; Hebrew Univ., Jerusalem

    1981-01-01

    EPR spectra of rat liver microsomes from male, female and hormonally-treated castrated hepatectomized rats were studied. The spectra, especially in the region of gsub(max) suggested a heterogeneity of local environments of the low spin ferric heme indicative of multiple structures for cytochrome P-450. Certain features in the spectrum correlated with sexual differences. It is suggested that the changes in the relative amplitudes of the EPR features represent differences in the relative abundance of the individual proteins in the mixture that, in turn, are related to the sexual differences of metabolic patterns for reactions catalyzed by cytochrome P-450. (author)

  9. Application of the relative activity factor approach in scaling from heterologously expressed cytochromes p450 to human liver microsomes: studies on amitriptyline as a model substrate.

    Science.gov (United States)

    Venkatakrishnan, K; von Moltke, L L; Greenblatt, D J

    2001-04-01

    The relative activity factor (RAF) approach is being increasingly used in the quantitative phenotyping of multienzyme drug biotransformations. Using lymphoblast-expressed cytochromes P450 (CYPs) and the tricyclic antidepressant amitriptyline as a model substrate, we have tested the hypothesis that the human liver microsomal rates of a biotransformation mediated by multiple CYP isoforms can be mathematically reconstructed from the rates of the biotransformation catalyzed by individual recombinant CYPs using the RAF approach, and that the RAF approach can be used for the in vitro-in vivo scaling of pharmacokinetic clearance from in vitro intrinsic clearance measurements in heterologous expression systems. In addition, we have compared the results of two widely used methods of quantitative reaction phenotyping, namely, chemical inhibition studies and the prediction of relative contributions of individual CYP isoforms using the RAF approach. For the pathways of N-demethylation (mediated by CYPs 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4) and E-10 hydroxylation (mediated by CYPs 2B6, 2D6, and 3A4), the model-predicted biotransformation rates in microsomes from a panel of 12 human livers determined from enzyme kinetic parameters of the recombinant CYPs were similar to, and correlated with the observed rates. The model-predicted clearance via N-demethylation was 53% lower than the previously reported in vivo pharmacokinetic estimates. Model-predicted relative contributions of individual CYP isoforms to the net biotransformation rate were similar to, and correlated with the fractional decrement in human liver microsomal reaction rates by chemical inhibitors of the respective CYPs, provided the chemical inhibitors used were specific to their target CYP isoforms.

  10. Radioprotection by dipyridamole in the aging mouse. Effects on lipid peroxidation in mouse liver, spleen and brain after whole-body X-ray irradiation

    International Nuclear Information System (INIS)

    Seino, Noritaka

    1995-01-01

    To investigate the radioprotective effect of dipyridamole in the aging mouse, the lipid peroxide content in aging mouse liver, spleen and brain irradiated by X-ray were measured both before and after injection of dipyridamole. The lipid peroxide content increased with aging from 2 months old to 16 months old in the mouse liver, spleen and brain. The content of lipid peroxide in the liver and spleen of the aging mouse was significantly increased in 7 days after whole-body irradiation with 8 Gy, but was unchanged in the brain. Dipyridamole, given before irradiation, significantly inhibited the increase of lipid peroxide after irradiation. These results suggest that dipyridamole may have radioprotective effects on aging mouse liver and spleen as well as on young mouse, and that inhibition of lipid peroxidation is a possible factor in the radioprotective effect of dipyridamole. (author)

  11. Characterization of in vitro glucuronidation clearance of a range of drugs in human kidney microsomes: comparison with liver and intestinal glucuronidation and impact of albumin.

    Science.gov (United States)

    Gill, Katherine L; Houston, J Brian; Galetin, Aleksandra

    2012-04-01

    Previous studies have shown the importance of the addition of albumin for characterization of hepatic glucuronidation in vitro; however, no reports exist on the effects of albumin on renal or intestinal microsomal glucuronidation assays. This study characterized glucuronidation clearance (CL(int, UGT)) in human kidney, liver, and intestinal microsomes in the presence and absence of bovine serum albumin (BSA) for seven drugs with differential UDP-glucuronosyltransferase (UGT) 1A9 and UGT2B7 specificity, namely, diclofenac, ezetimibe, gemfibrozil, mycophenolic acid, naloxone, propofol, and telmisartan. The impact of renal CL(int, UGT) on accuracy of in vitro-in vivo extrapolation (IVIVE) of glucuronidation clearance was investigated. Inclusion of 1% BSA for acidic drugs and 2% for bases/neutral drugs in incubations was found to be suitable for characterization of CL(int, UGT) in different tissues. Although BSA increased CL(int, UGT) in all tissues, the extent was tissue- and drug-dependent. Scaled CL(int, UGT) in the presence of BSA ranged from 2.22 to 207, 0.439 to 24.4, and 0.292 to 23.8 ml · min(-1) · g tissue(-1) in liver, kidney, and intestinal microsomes. Renal CL(int, UGT) (per gram of tissue) was up to 2-fold higher in comparison with that for liver for UGT1A9 substrates; in contrast, CL(int, UGT) for UGT2B7 substrates represented approximately one-third of hepatic estimates. Scaled renal CL(int, UGT) (in the presence of BSA) was up to 30-fold higher than intestinal glucuronidation for the drugs investigated. Use of in vitro data obtained in the presence of BSA and inclusion of renal clearance improved the IVIVE of glucuronidation clearance, with 50% of drugs predicted within 2-fold of observed values. Characterization and consideration of kidney CL(int, UGT) is particularly important for UGT1A9 substrates.

  12. Hepatic microsomal phospholipids in rats exposed intratracheally to coal fly ash

    International Nuclear Information System (INIS)

    Srivastava, P.K.; Chauhan, S.S.; Misra, U.K.

    1986-01-01

    The effects of intratracheal administration of fly ash (50 mg/kg body weight, daily for 7 days) on hepatic microsomal phospholipid metabolism has been studied in rats using various phospholipid precursors, viz NaH 2 32 PO 4 , (methyl- 14 C)-choline, and (methyl- 14 C)-methionine. Fly ash administration significantly increased microsomal phosphatidylcholine (PC), and lysophosphatidylcholine (LPC). The incorporation of NaH 2 32 PO 4 into total liver phospholipids, PC and Phosphatidyl ethanolamine (PE) was significantly increased in fly ash-treated rats as compared to the control. Fly ash administration also increased the incorporation of (methyl- 14 C)-choline into microsomal PC. Incorporation of (methyl- 14 C)-methionine into microsomal PC was not affected. Fly ash administration decreased the per cent distribution of arachidonic acid in PC and PE and increased that of oleic acid in PC and of linoleic acid in PE. (orig.)

  13. Haemozoin Detection in Mouse Liver Histology Using Simple Polarized Light Microscope

    OpenAIRE

    DWI RAMADHANI; SITI NURHAYATI; TUR RAHARDJO

    2014-01-01

    The presence of malarial pigment (haemozoin) due to Plasmodium infection is a common histopathological effect in mouse liver. Previous research showed that by using a polarized light microscope, researchers were better able to detect haemozoin in mouse liver histology section. Thus, the aim of this research was to compare the haemozoin area observed by a conventional vs. simple polarized light microscope by using image processing analysis. A total of 40 images produced from both conventional ...

  14. Genome-wide identification of estrogen receptor alpha-binding sites in mouse liver

    DEFF Research Database (Denmark)

    Gao, Hui; Fält, Susann; Sandelin, Albin

    2007-01-01

    We report the genome-wide identification of estrogen receptor alpha (ERalpha)-binding regions in mouse liver using a combination of chromatin immunoprecipitation and tiled microarrays that cover all nonrepetitive sequences in the mouse genome. This analysis identified 5568 ERalpha-binding regions...... genes. The majority of ERalpha-binding regions lie in regions that are evolutionarily conserved between human and mouse. Motif-finding algorithms identified the estrogen response element, and variants thereof, together with binding sites for activator protein 1, basic-helix-loop-helix proteins, ETS...... signaling in mouse liver, by characterizing the first step in this signaling cascade, the binding of ERalpha to DNA in intact chromatin....

  15. A reliable radiochromatographic assay technique for hepatic microsomal 16α-hydroxylase activity towards oestrone 3-sulphate

    International Nuclear Information System (INIS)

    Tsoutsoulis, C.J.; Hobkirk, R.

    1980-01-01

    A reliable procedure for the assay of liver microsomal 16α-hydroxylation of oestrone 3-sulphate has been developed for the guinea pig. It is based on the rapid, quantitative separation of oestradiol and oestriol by Sephadex LH-20 columns after the chemical reduction and enzymic hydrolysis of the incubation products. Microsomal preparations and incubation conditions that optimized 16α-hydroxylation of oestrone 3-sulphate were employed. Under these circumstances, reduction of the substrate at C-17 and hydrolysis of the sulphate were minimized. Conditions were established that yielded reaction linearity with respect to time and microsomal concentration. This hydroxylation had an absolute requirement for NADPH, which could not be satisfied by NADH. Apparent Ksub(m) values for oestrone 3-sulphate and NADPH, under the conditions used, were 14μM and 0.17mM respectively. 16α-hydroxylase activity was present in the liver microsomal fraction from heavily pigmented, female English Shorthaired guinea pigs. Much lower activity was detected in mature pigmented males and albino females. No activity could be demonstrated in mature, albino males. (author)

  16. Detection of liver kidney microsomal type 1 antibody using molecularly based immunoassays.

    Science.gov (United States)

    Kerkar, N; Ma, Y; Davies, E T; Cheeseman, P; Mieli-Vergani, G; Vergani, D

    2002-12-01

    To assess the diagnostic value of two commercial molecularly based immunoassays detecting liver kidney microsomal type 1 antibody (LKM1). The performance of Varelisa and LKM1 enzyme linked immunosorbent assay (ELISA) was compared with immunofluorescence, and two validated research techniques-an in house ELISA and a radioligand assay measuring antibodies to P4502D6. Thirty serum samples from three patients with autoimmune hepatitis type 2 covering immunofluorescence titres of 1/10 to 1/10 240 and 55 LKM1 negative controls were tested. All 30 sera that were LKM1 positive by immunofluorescence were positive by the in house ELISA, the radioligand assay, and LKM1-ELISA, and 29 were also positive by Varelisa. None of the 55 sera negative for LKM1 by immunofluorescence was positive by the in house ELISA and radioligand assay, but one was positive by Varelisa and 14 were positive using the LKM1-ELISA. Agreement between immunofluorescence, the in house ELISA, the radioligand assay, and Varelisa was high (kappa > 0.8), and agreement between immunofluorescence and LKM1-ELISA was moderate (kappa = 0.63). The assay kit marketed as Varelisa allows accurate detection of LKM1.

  17. Mouse models in liver cancer research: A review of current literature

    Science.gov (United States)

    Leenders, Martijn WH; Nijkamp, Maarten W; Rinkes, Inne HM Borel

    2008-01-01

    Primary liver cancer remains one of the most lethal malignancies worldwide. Due to differences in prevalence of etiological factors the incidence of primary liver cancer varies among the world, with a peak in East-Asia. As this disease is still lethal in most of the cases, research has to be done to improve our understanding of the disease, offering insights for possible treatment options. For this purpose, animal models are widely used, especially mouse models. In this review, we describe the different types of mouse models used in liver cancer research, with emphasis on genetically engineered mice used in this field. We focus on hepatocellular carcinoma (HCC), as this is by far the most common type of primary liver cancer, accounting for 70%-85% of cases. PMID:19058325

  18. Evidence of a genetic basis for the different geographic occurrences of liver/kidney microsomal antibody type 1 in hepatitis C.

    Science.gov (United States)

    Muratori, Paolo; Czaja, Albert J; Muratori, Luigi; Granito, Alessandro; Guidi, Marcello; Ferri, Silvia; Volta, Umberto; Mantovani, Wilma; Pappas, Georgios; Cassani, Fabio; Lenzi, Marco; Bianchi, Francesco B

    2007-01-01

    Antibodies to liver/kidney microsome type 1 occur in Italian patients with hepatitis C, but rarely develop in North American patients. Our goals were to compare the frequencies of the HLA markers associated with autoimmune expression in Italian and North American patients with chronic hepatitis C and to determine genetic bases for regional differences in antibody production. HLA B8, DR3, DR4, DR7, DR11, DR13, DQ2, and the B8-DR3-DQ2 haplotype were determined by microlymphocytotoxicity and polymerase chain reaction in 105 Italian patients (50 with microsomal antibodies), 100 North American patients (none with microsomal antibodies), and Italian and North American healthy control subjects. Italian patients with microsomal antibodies differed from North American patients without these antibodies by having a higher frequency of HLA DR7 (54% vs. 27%, P=0.002). HLA DR7 occurred more frequently in seropositive Italian patients than in seronegative counterparts (54% vs. 11% P < 0.0001), Italian healthy control subjects (54% vs. 29%, P=0.0009), and North American healthy control subjects (54% vs. 19%, P < 0.0001). The frequency of HLA DR7 was similar in North American patients and controls (27% vs. 19%, P=0.2), but it was lower than in Italian controls (19% vs. 29%, P=0.059). Seropositive Italian patients had a lower frequency of HLA DR11 than seronegative Italian patients and Italian controls (18% vs. 34%, P=0.07, and 18% vs. 35%, P=0.02, respectively). In contrast to seropositive Italian patients, North American patients had HLA DR4 (30% vs. 12%, P=0.02), HLA DR13 (29% vs. 10%, P=0.01), and the B8-DR3-DQ2 haplotype (23% vs. 6%, P=0.01) more often. Similarly, HLA DR4 and the B8-DR3-DQ2 phenotype were more frequent in North American patients than in Italian controls (30% vs. 16%, P=0.005, and 23% vs. 7%, P=0.00002, respectively). HLA DR7 is associated with the development of microsomal antibodies in Italian patients with chronic hepatitis C. The lower frequency of HLA DR7

  19. Hepatic and intestinal glucuronidation of mono(2-ethylhexyl) phthalate, an active metabolite of di(2-ethylhexyl) phthalate, in humans, dogs, rats, and mice: an in vitro analysis using microsomal fractions.

    Science.gov (United States)

    Hanioka, Nobumitsu; Isobe, Takashi; Kinashi, Yu; Tanaka-Kagawa, Toshiko; Jinno, Hideto

    2016-07-01

    Mono(2-ethylhexyl) phthalate (MEHP) is an active metabolite of di(2-ethylhexyl) phthalate (DEHP) and has endocrine-disrupting effects. MEHP is metabolized into glucuronide by UDP-glucuronosyltransferase (UGT) enzymes in mammals. In the present study, the hepatic and intestinal glucuronidation of MEHP in humans, dogs, rats, and mice was examined in an in vitro system using microsomal fractions. The kinetics of MEHP glucuronidation by liver microsomes followed the Michaelis-Menten model for humans and dogs, and the biphasic model for rats and mice. The K m and V max values of human liver microsomes were 110 µM and 5.8 nmol/min/mg protein, respectively. The kinetics of intestinal microsomes followed the biphasic model for humans, dogs, and mice, and the Michaelis-Menten model for rats. The K m and V max values of human intestinal microsomes were 5.6 µM and 0.40 nmol/min/mg protein, respectively, for the high-affinity phase, and 430 µM and 0.70 nmol/min/mg protein, respectively, for the low-affinity phase. The relative levels of V max estimated by Eadie-Hofstee plots were dogs (2.0) > mice (1.4) > rats (1.0) ≈ humans (1.0) for liver microsomes, and mice (8.5) > dogs (4.1) > rats (3.1) > humans (1.0) for intestinal microsomes. The percentages of the V max values of intestinal microsomes to liver microsomes were mice (120 %) > rats (57 %) > dogs (39 %) > humans (19 %). These results suggest that the metabolic abilities of UGT enzymes expressed in the liver and intestine toward MEHP markedly differed among species, and imply that these species differences are strongly associated with the toxicity of DEHP.

  20. 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.

  1. Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver.**

    Science.gov (United States)

    We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclo...

  2. Quantitative changes in endogenous DNA adducts correlate with conazole mutagenicity and tumorigenicity in mouse liver.

    Science.gov (United States)

    We have previously shown that the conazole fungicides triadimefon and propiconazole, which are tumorigenic in mouse liver, are in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses. The nontumorigenic conazole myclo...

  3. Interaction of rocuronium with human liver cytochromes P450

    OpenAIRE

    Anzenbacherova, Eva; Spicakova, Alena; Jourova, Lenka; Ulrichova, Jitka; Adamus, Milan; Bachleda, Petr; Anzenbacher, Pavel

    2015-01-01

    Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver micro...

  4. Withaferin A Suppresses Liver Tumor Growth in a Nude Mouse ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of withaferin A on tumor growth and metastasis in liver in a nude mouse model. Methods: Withaferin A was injected through a portal vein to the orthotopic liver tumor in a nude mice model. Xenogen in vivo imaging system was used to monitor tumor growth and metastasis. The effect of ...

  5. Radioprotection of liver lipids of whole-body gamma-irradiated female rats by cystamine

    International Nuclear Information System (INIS)

    Ramanathan, R.; Misra, U.K.

    1976-01-01

    The effect of administration of cystamine (5 mg/100 g body weight) before 1,200 R whole-body gamma irradiation has been studied on irradiation-induced changes in liver and its subcellular fractions'lipids of fasted female rats. Cystamine prevented the irradiation-induced increase in liver triglycerides and liver mitochondrial total phospholipids, but it decreased microsomal total phospholipids and proteins. Cystamine prevented the radiation-induced increased 32 P-radioactivity (counts/min/μmole phospholipid phosphorus) of microsomal phosphatidyl choline. Cystamine prevented the radiation-induced increased uptake of NaH 2 32 PO 4 (counts/min/g liver) in liver microsomal phosphatidyl ethanolamine and supernatant phosphatidyl choline; but in microsomal phosphatidyl choline, cystamine did not do so, but on the other hand it itself increased the uptake in control rats. Cystamine did not prevent the irradiation-induced decreased incorporation of (U- 14 C)glucose into liver triglycerides, total phospholipids and phosphatidyl choline. Cystamine itself decreased the incorporation of (U- 14 C)glucose into liver triglycerides and phosphoglycerides of control rats. (orig.) [de

  6. Liver BCATm transgenic mouse model reveals the important role of the liver in maintaining BCAA homeostasis.

    Science.gov (United States)

    Ananieva, Elitsa A; Van Horn, Cynthia G; Jones, Meghan R; Hutson, Susan M

    2017-02-01

    Unlike other amino acids, the branched-chain amino acids (BCAAs) largely bypass first-pass liver degradation due to a lack of hepatocyte expression of the mitochondrial branched-chain aminotransferase (BCATm). This sets up interorgan shuttling of BCAAs and liver-skeletal muscle cooperation in BCAA catabolism. To explore whether complete liver catabolism of BCAAs may impact BCAA shuttling in peripheral tissues, the BCATm gene was stably introduced into mouse liver. Two transgenic mouse lines with low and high hepatocyte expression of the BCATm transgene (LivTg-LE and LivTg-HE) were created and used to measure liver and plasma amino acid concentrations and determine whether the first two BCAA enzymatic steps in liver, skeletal muscle, heart and kidney were impacted. Expression of the hepatic BCATm transgene lowered the concentrations of hepatic BCAAs while enhancing the concentrations of some nonessential amino acids. Extrahepatic BCAA metabolic enzymes and plasma amino acids were largely unaffected, and no growth rate or body composition differences were observed in the transgenic animals as compared to wild-type mice. Feeding the transgenic animals a high-fat diet did not reverse the effect of the BCATm transgene on the hepatic BCAA catabolism, nor did the high-fat diet cause elevation in plasma BCAAs. However, the high-fat-diet-fed BCATm transgenic animals experienced attenuation in the mammalian target of rapamycin (mTOR) pathway in the liver and had impaired blood glucose tolerance. These results suggest that complete liver BCAA metabolism influences the regulation of glucose utilization during diet-induced obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

    Science.gov (United States)

    Kukiełka, E; Cederbaum, A I

    1995-04-15

    Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid DNA into the relaxed open circular state. The plasmid used was pBluescript II KS(-), and the forms of DNA were separated by agarose-gel electrophoresis. Incubation of rat liver microsomes with plasmid plus NADH plus ferric-ATP caused DNA strand cleavage. The addition of rifamycin SV produced a time- and concentration-dependent increase in DNA-strand cleavage. No stimulation by rifamycin SV occurred in the absence of microsomes, NADH or ferric-ATP. Stimulation occurred with other ferric complexes besides ferric-ATP, e.g. ferric-histidine, ferric-citrate, ferric-EDTA, and ferric-(NH4)2SO4. Rifamycin SV did not significantly increase the high rates of DNA strand cleavage found with NADPH as the microsomal reductant. The stimulation of NADH-dependent microsomal DNA strand cleavage was completely blocked by catalase, superoxide dismutase, GSH and a variety of hydroxyl-radical-scavenging agents, but not by anti-oxidants that prevent microsomal lipid peroxidation. Redox cycling agents, such as menadione and paraquat, in contrast with rifamycin SV, stimulated the NADPH-dependent reaction; menadione and rifamycin SV were superior to paraquat in stimulating the NADH-dependent reaction. These results indicate that rifamycin SV can, in the presence of an iron catalyst, increase microsomal production of reactive oxygen species which can cause DNA-strand cleavage. In contrast with other redox cycling agents, the stimulation by rifamycin SV is more pronounced with NADH than with NADPH as the

  8. Effect of ethionine on hepatic mitochondrial and microsomal calcium uptake

    International Nuclear Information System (INIS)

    Agarwal, A.K.; Zinermon, W.D.; Latoni, L.

    1988-01-01

    Ethionine, an ethyl analog of methionine, produces a variety of physiological and pathological effects in animals. These range from acute effects in the liver, kidney, pancreas, and other organs to liver carcinogenesis. Female rats when injected with ethionine exhibit a rapid decrease in hepatic adenosine triphosphate levels followed by a marked inhibition of RNA and protein synthesis and accumulation of triglycerides. Since calcium transport in mitochondria and microsomes is ATP dependent, it becomes interesting to find out if ethionine administration has any effect on subcellular calcium transport. Calcium has recently gained an increased controversy regarding its role in chemical induced lethal cell damage. Certain groups believe that influx of extracellular calcium across the damaged plasma membrane might actually mediate the irreversible damage to the cell, whereas according to other, entry of calcium into the cell is secondary to the damage. The present study was carried out to investigate the calcium [ 45 Ca] transport in mitochondria and microsomes following ethionine administration. The effect of carbon tetrachloride on calcium uptake in ethionine treated rats was also studied

  9. EFFECTS OF THIOL ANTIOXIDANTS ON THE ATROPSELECTIVE OXIDATION OF 2,2′,3,3′,6,6′-HEXACHLOROBIPHENYL (PCB 136) BY RAT LIVER MICROSOMES

    Science.gov (United States)

    Wu, Xianai; Lehmler, Hans-Joachim

    2015-01-01

    Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0–10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol), 4-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol) and 4,5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136 and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo. PMID:26155892

  10. Sex-related difference in the inductions by perfluoro-octanoic acid of peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase in rat liver.

    Science.gov (United States)

    Kawashima, Y; Uy-Yu, N; Kozuka, H

    1989-01-01

    Inductions by perfluoro-octanoic acid (PFOA) of hepatomegaly, peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase were compared in liver between male and female rats. Marked inductions of these four parameters were seen concurrently in liver of male rats, whereas the inductions in liver of female rats were far less pronounced. The sex-related difference in the response of rat liver to PFOA was much more marked than that seen with p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). Hormonal manipulations revealed that this sex-related difference in the inductions is strongly dependent on sex hormones, namely that testosterone is necessary for the inductions, whereas oestradiol prevented the inductions by PFOA. PMID:2570571

  11. Haemozoin Detection in Mouse Liver Histology Using Simple Polarized Light Microscope

    Directory of Open Access Journals (Sweden)

    DWI RAMADHANI

    2014-03-01

    Full Text Available The presence of malarial pigment (haemozoin due to Plasmodium infection is a common histopathological effect in mouse liver. Previous research showed that by using a polarized light microscope, researchers were better able to detect haemozoin in mouse liver histology section. Thus, the aim of this research was to compare the haemozoin area observed by a conventional vs. simple polarized light microscope by using image processing analysis. A total of 40 images produced from both conventional light microscope and simple polarized light microscope were collected. All images were analyzed using ImageJ 1.47 software to measure the haemozoin areas. Our results showed that non birefringent haemozoin and birefringent haemozoin area was significantly different. This was because when using conventional light microscope the brown area that contained images of non birefringent haemozoin images also contained Kupffer cells which appeared as the same brown color as haemozoin. In contrast, haemozoin gave bright effect and can be easily differentiated with Kupffer cells in the birefringent haemozoin images. This study concluded that haemozoin detection in mouse liver histology using a simple polarized light microscope was more accurate compared to that of conventional light microscope.

  12. Identification of AKB-48 and 5F-AKB-48 Metabolites in Authentic Human Urine Samples Using Human Liver Microsomes and Time of Flight Mass Spectrometry

    OpenAIRE

    Vikingsson, Svante; Josefsson, Martin; Green, Henrik

    2015-01-01

    The occurrence of structurally related synthetic cannabinoids makes the identification of unique markers of drug intake particularly challenging. The aim of this study was to identify unique and abundant metabolites of AKB-48 and 5F-AKB-48 for toxicological screening in urine. Investigations of authentic urine samples from forensic cases in combination with human liver microsome (HLM) experiments were used for identification of metabolites. HLM incubations of AKB-48 and 5F-AKB-48 along with 3...

  13. N-Hydroxylation of 4-Aminobiphenyl by CYP2E1 Produces Oxidative Stress in a Mouse Model of Chemically Induced Liver Cancer

    Science.gov (United States)

    Wang, Shuang; Sugamori, Kim S.; Tung, Aveline; McPherson, J. Peter; Grant, Denis M.

    2015-01-01

    4-Aminobiphenyl (ABP) is a trace component of cigarette smoke and hair dyes, a suspected human carcinogen and a potent rodent liver carcinogen. Postnatal exposure of mice to ABP results in a higher incidence of liver tumors in males than in females, paralleling the sex difference in human liver cancer incidence. A traditional model of ABP tumorigenesis involves initial CYP1A2-mediated N-hydroxylation, which eventually leads to production of mutagenic ABP-DNA adducts that initiate tumor growth. However, several studies have found no correlation between sex or CYP1A2 function and the DNA-damaging, mutagenic, or tumorigenic effects of ABP. Oxidative stress may be an important etiological factor for liver cancer, and it has also been linked to ABP exposure. The goals of this study were to identify novel enzyme(s) that contribute to ABP N-oxidation, and to investigate a potential role for oxidative stress in ABP liver tumorigenicity. Isozyme-selective inhibition experiments using liver microsomes from wild-type and genetically modified mice identified CYP2E1 as a major ABP N-hydroxylating enzyme. The N-hydroxylation of ABP by transiently expressed CYP2E1 produced oxidative stress in cultured mouse hepatoma cells. In vivo postnatal exposure of mice to a tumorigenic dose of ABP also produced oxidative stress in male wild-type mice, but not in male Cyp2e1(−/−) mice or in female mice. However, a stronger NRF2-associated antioxidant response was observed in females. Our results identify CYP2E1 as a novel ABP-N-oxidizing enzyme, and suggest that sex differences in CYP2E1-dependent oxidative stress and antioxidant responses to ABP may contribute to the observed sex difference in tumor incidence. PMID:25601990

  14. Strategy for Hepatotoxicity Prediction Induced by Drug Reactive Metabolites Using Human Liver Microsome and Online 2D-Nano-LC-MS Analysis.

    Science.gov (United States)

    Zhuo, Yue; Wu, Jian-Lin; Yan, Xiaojing; Guo, Ming-Quan; Liu, Ning; Zhou, Hua; Liu, Liang; Li, Na

    2017-12-19

    Hepatotoxicity is a leading cause of drug withdrawal from the market; thus, the assessment of potential drug induced liver injury (DILI) in preclinical trials is necessary. More and more research has shown that the covalent modification of drug reactive metabolites (RMs) for cellular proteins is a possible reason for DILI. Unfortunately, so far no appropriate method can be employed to evaluate this kind of DILI due to the low abundance of RM-protein adducts in complex biological samples. In this study, we proposed a mechanism-based strategy to solve this problem using human liver microsomes (HLMs) and online 2D nano-LC-MS analysis. First, RM modification patterns and potential modified AA residues are determined using HLM and model amino acids (AAs) by UHPLC-Q-TOF-MS. Then, a new online 2D-nano-LC-Q-TOF-MS method is established and applied to separate the digested modified microsomal peptides from high abundance peptides followed by identification of RM-modified proteins using Mascot, in which RM modification patterns on specific AA residues are added. Finally, the functions and relationship with hepatotoxicity of the RM-modified proteins are investigated using ingenuity pathway analysis (IPA) to predict the possible DILI. Using this strategy, 21 proteins were found to be modified by RMs of toosendanin, a hepatotoxic drug with complex structure, and some of them have been reported to be associated with hepatotoxicity. This strategy emphasizes the identification of drug RM-modified proteins in complex biological samples, and no pretreatment is required for the drugs. Consequently, it may serve as a valuable method to predict potential DILI, especially for complex compounds.

  15. Overexpression of Catalase Enhances Benzo(a)pyrene Detoxification in Endothelial Microsomes.

    Science.gov (United States)

    Yang, Fang; Yang, Hong; Ramesh, Aramandla; Goodwin, J Shawn; Okoro, Emmanuel U; Guo, ZhongMao

    2016-01-01

    We previously reported that overexpression of catalase upregulated xenobiotic- metabolizing enzyme (XME) expression and diminished benzo(a)pyrene (BaP) intermediate accumulation in mouse aortic endothelial cells (MAECs). Endoplasmic reticulum (ER) is the most active organelle involved in BaP metabolism. To examine the involvement of ER in catalase-induced BaP detoxification, we compared the level and distribution of XMEs, and the profile of BaP intermediates in the microsomes of wild-type and catalase transgenic endothelial cells. Our data showed that endothelial microsomes were enriched in cytochrome P450 (CYP) 1A1, CYP1B1 and epoxide hydrolase 1 (EH1), and contained considerable levels of quinone oxidoreductase-1 (NQO1) and glutathione S-transferase-pi (GSTP). Treatment of wild-type MAECs with 1μM BaP for 2 h increased the expression of microsomal CYP1A1, 1B1 and NQO1 by ~300, 64 and 116%, respectively. However, the same treatment did not significantly alter the expression of EH1 and GSTP. Overexpression of catalase did not significantly increase EH1, but upregulated BaP-induced expression of microsomal CYP1A1, 1B1, NQO1 and GSTP in the following order: 1A1>NQO1>GSTP>1B1. Overexpression of catalase did not alter the distribution of each of these enzymes in the microsomes. In contrast to our previous report showing lower level of BaP phenols versus BaP diols/diones in the whole-cell, this report demonstrated that the sum of microsomal BaP phenolic metabolites were ~60% greater than that of the BaP diols/diones after exposure of microsomes to BaP. Overexpression of catalase reduced the concentrations of microsomal BaP phenols and diols/diones by ~45 and 95%, respectively. This process enhanced the ratio of BaP phenol versus diol/dione metabolites in a potent manner. Taken together, upregulation of phase II XMEs and CYP1 proteins, but not EH1 in the ER might be the mechanism by which overexpression of catalase reduces the levels of all the BaP metabolites, and

  16. Effect of rat whole-body irradiation on oxidase chain and glucose-6-phosphatase of liver microsome: influence of cysteamine

    International Nuclear Information System (INIS)

    Bernard, Pierre.

    1979-11-01

    Three enzymatic systems of the male rat liver endoplasmic reticulum were studied by biochemical methods. Two means of investigation were used: - whole-body irradiation of the animal, - administration of cysteamine. The results obtained are discussed, in view of the functioning of these enzymatic systems, from two viewpoints: - the study of enzymatic radiolesions in relation to the radiobiological effect on the animal, the organ and the sub-cellular organite, - the study of chemical radioprotection. After a 900 R whole-body gamma irradiation a severe drop was observed in the enzymatic activity of two essential elements of the microsome oxydase chain: NADPH cytochrome P450 reductase and ethylmorphine N-demethylation. Glucose 6 phosphatase is also impaired by irradiation. Here it seems that the microsomal protein fraction could be responsible for the change in the enzyme activity. The irradiation effect is therefore not specific to one enzyme. The changes in these enzymatic activities correspond to the different phases of the acute irradiation syndrome which also affects the weight of the experimental animal and of the organ studied. Cysteamine used under chemical radioprotection conditions was found to be especially useful as a means of investigation complementary to the study of enzymatic radiolesions. From the combined action of irradiation and of the radioprotector it was possible to obtain a partial idea of the mechanisms of these radiolesions [fr

  17. 2'-Deoxyguanosine as a surrogate trapping agent for DNA reactive drug metabolites.

    Science.gov (United States)

    Häkkinen, Merja R; Laine, Jaana E; Juvonen, Risto O; Auriola, Seppo; Häyrinen, Jukka; Pasanen, Markku

    2011-11-10

    Drug metabolism can result in the production of highly reactive metabolites that may form adducts with cellular macromolecules, and thus initiate adverse drug reactions, cause toxicity, and even require the withdrawal of drug from the market. In this study, a 2'-deoxyguanosine (dG)-based chemical trapping test system was developed for use as a fast screening tool for DNA adducting metabolites of new drug candidates. Reactive metabolites were generated from parent compounds in in vitro incubations with phenobarbital-induced mouse liver microsomes, human liver microsomes and different recombinant human CYP enzymes in the presence of dG. The formed dG-adducts were separated, characterized and their stability was studied by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was evaluated with six test compounds, aflatoxin B1, estrone, clozapine, tolcapone, ticlopidine and imipramine. Estrone and aflatoxin B1 formed dG adducts with phenobarbital-induced mouse liver microsomes, human liver microsomes and human recombinant CYP enzymes. Adduct formation was also observed with tolcapone when phenobarbital-induced mouse liver microsomes were used as the enzyme source. The stability of each formed adduct was independent of the different enzyme sources. No dG-adducts were identified with ticlopidine, clozapine and imipramine. Compared to other classical DNA reactivity tests, e.g. Ames test, the present surrogate endpoint, the dG adduct, is faster, enables the characterization of the formed compounds, and also permits the investigation of more unstable adducts. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. The role of CYP2D6 in primary and secondary oxidative metabolism of dextromethorphan: in vitro studies using human liver microsomes.

    Science.gov (United States)

    Kerry, N L; Somogyi, A A; Bochner, F; Mikus, G

    1994-01-01

    1. The enzyme kinetics of dextromethorphan O-demethylation in liver microsomes from three extensive metabolisers (EM) with respect to CYP2D6 indicated high (Km1 2.2-9.4 microM) and low (Km2 55.5-307.3 microM) affinity sites whereas microsomes from two poor metabolisers (PM) indicated a single site (Km 560 and 157 microM). Similar differences were shown for 3-methoxymorphinan O-demethylation to 3-hydroxymorphinan (Km 6.9-9.6 microM in EM subjects; Km 307 and 213 microM in PM subjects). 2. Dextromethorphan O-demethylation was inhibited competitively by quinidine (Ki 0.1 microM), rac-perhexiline (Ki 0.4 microM), dextropropoxyphene (Ki 6 microM), rac-methadone (Ki 8 microM), and 3-methoxymorphinan (Ki 15 microM). These compounds were also potent inhibitors of 3-methoxymorphinan O-demethylation with IC50 values ranging from 0.02-12 microM. Anti-LKM1 serum inhibited both dextromethorphan and 3-methoxymorphinan O-demethylations in a titre-dependent manner. 3. The Michaelis-Menten constant for dextromethorphan N-demethylation to 3-methoxymorphinan (Km 632-977 microM) and dextrorphan N-demethylation to 3-hydroxymorphinan (Km 1571-4286 microM) did not differ between EM and PM microsomes. These N-demethylation reactions were not inhibited by quinidine and rac-methadone or LKM1 antibodies. 4. Dextromethorphan and 3-methoxymorphinan are metabolised by the same P450 isoform, CYP2D6, whereas the N-demethylation reactions are not carried out by CYP2D6. PMID:7826826

  19. Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by ( sup 3 H)flunitrazepam

    Energy Technology Data Exchange (ETDEWEB)

    Thomassin, J.; Tephly, T.R. (Univ. of Iowa, Iowa City (USA))

    1990-09-01

    Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of (3H)flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with (3H) flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000).

  20. Antibody to liver cytosol (anti-LC1) in patients with autoimmune chronic active hepatitis type 2.

    Science.gov (United States)

    Martini, E; Abuaf, N; Cavalli, F; Durand, V; Johanet, C; Homberg, J C

    1988-01-01

    A new autoantibody was detected by immunoprecipitation in the serum of 21 patients with chronic active hepatitis. The antibody reacted against a soluble cytosolic antigen in liver. The antibody was organ specific but not species specific and was therefore called anti-liver cytosol antibody Type 1 (anti-LC1). In seven of 21 cases, no other autoantibody was found; the remaining 14 cases had anti-liver/kidney microsome antibody Type 1 (anti-LKM1). With indirect immunofluorescence, a distinctive staining pattern was observed with the seven sera with anti-LC1 and without anti-LKM1. The antibody stained the cytoplasm of hepatocytes from four different animal species and spared the cellular layer around the central veins of mouse and rat liver that we have called juxtavenous hepatocytes. The immunofluorescence pattern disappeared after absorption of sera by a liver cytosol fraction. The 14 sera with both antibodies displayed anti-LC1 immunofluorescent pattern after absorption of anti-LKM1 by the liver microsomal fraction. The anti-LC1 was found in the serum only in patients with chronic active hepatitis of unknown cause. Anti-LC1 antibody was not found in sera from 100 patients with chronic active hepatitis associated with anti-actin antibody classic chronic active hepatitis Type 1, 100 patients with primary biliary cirrhosis, 157 patients with drug-induced hepatitis and a large number of patients with liver and nonliver diseases. This new antibody was considered a second marker of chronic active hepatitis associated with anti-LKM1 (anti-LKM1 chronic active hepatitis) or autoimmune chronic active hepatitis Type 2.

  1. In vitro investigation of cytochrome P450-mediated metabolism of dietary flavonoids

    DEFF Research Database (Denmark)

    Breinholt, Vibeke; Offord, E.A.; Brouwer, C.

    2002-01-01

    Human and mouse liver microsomes And membranes isolated from Escherichia coli, which expressed cytochrome P450 (CYP) 1A2, 3A4 2C9 or 2D6, were used to investigate CYP-mediated metabolism of five selected dietary flavonoids. In human and mouse liver microsomes kaempferol, apigenin and naringenin...... were hydroxylated at the 3'-position to yield their corresponding analogs quercetin, luteolin and eriodietyol, whereas hesperetin and tamarixetin were demethylated at the 4'-position to yield eriodictyol and quercetin. respectively, Microsomal flavonoid metabolism as potently inhibited by the CYP1A2...... inhibitors. fluvoxamine and alpha-naphthoflavone. Recombinant CYP1A2 as capable of metabolizing all five investigated flavonoids. CYP3A4 recombinant protein did not catalyze hesperetin demethylation. but showed similar metabolic profiles for the remaining compounds, as did human microsomes and recombinant...

  2. Therapeutic efficacy of human hepatocyte transplantation in a SCID/uPA mouse model with inducible liver disease.

    Directory of Open Access Journals (Sweden)

    Donna N Douglas

    2010-02-01

    Full Text Available Severe Combined Immune Deficient (SCID/Urokinase-type Plasminogen Activator (uPA mice undergo liver failure and are useful hosts for the propagation of transplanted human hepatocytes (HH which must compete with recipient-derived hepatocytes for replacement of the diseased liver parenchyma. While partial replacement by HH has proven useful for studies with Hepatitis C virus, complete replacement of SCID/uPA mouse liver by HH has never been achieved and limits the broader application of these mice for other areas of biomedical research. The herpes simplex virus type-1 thymidine kinase (HSVtk/ganciclovir (GCV system is a powerful tool for cell-specific ablation in transgenic animals. The aim of this study was to selectively eliminate murine-derived parenchymal liver cells from humanized SCID/uPA mouse liver in order to achieve mice with completely humanized liver parenchyma. Thus, we reproduced the HSVtk (vTK/GCV system of hepatic failure in SCID/uPA mice.In vitro experiments demonstrated efficient killing of vTK expressing hepatoma cells after GCV treatment. For in vivo experiments, expression of vTK was targeted to the livers of FVB/N and SCID/uPA mice. Hepatic sensitivity to GCV was first established in FVB/N mice since these mice do not undergo liver failure inherent to SCID/uPA mice. Hepatic vTK expression was found to be an integral component of GCV-induced pathologic and biochemical alterations and caused death due to liver dysfunction in vTK transgenic FVB/N and non-transplanted SCID/uPA mice. In SCID/uPA mice with humanized liver, vTK/GCV caused death despite extensive replacement of the mouse liver parenchyma with HH (ranging from 32-87%. Surprisingly, vTK/GCV-dependent apoptosis and mitochondrial aberrations were also localized to bystander vTK-negative HH.Extensive replacement of mouse liver parenchyma by HH does not provide a secure therapeutic advantage against vTK/GCV-induced cytotoxicity targeted to residual mouse hepatocytes

  3. Luminol-and lucigenin-amplified chemiluminescence with rat liver microsomes. Kinetics and influence of ascorbic acid, glutathione, dimethylsulfoxide, N-t-butyl-a-phenyl-nitrone, copper-ions and a copper complex, catalase, superoxide dismutase, hexobarbital and aniline.

    Science.gov (United States)

    Klinger, W; Karge, E; Kretzschmar, M; Rost, M; Schulze, H P; Dargel, R; Reinemann, C; Rein, H

    1996-07-01

    For the investigation of luminol (LM)-and lucigenin (LC)-amplified chemiluminescence (CL) in rat liver microsomes using both a liquid-scintillation counter (LKB/Wallac 1219 Rackbeta) and a Berthold luminometer (AutoLumat LB 953) optimal incubation mixtures and conditions and basic kinetics have been established. Whereas calibration curves for both LM- and LC-CL are performed with hydrogenperoxide (LC quantum yield is 6.25 fold higher as that of LM), distinct differences were revealed with microsomes, indicating that different reactive oxygen species (ROS) are determined: Both LM- and LC-CL follow the kinetics of enzymatic reactions in terms of dependence on protein and NADPH or NADH concentration, time course, temperature etc., but with differences. LM-CL does not work without addition of Fe2+, whereas LC-CL does. Both copper ions and copper bound in a complex abolish CL, LC-CL being much more sensitive. Isolated cytochrome P-450 (P450) and NADPH P450 reductase from liver of pheno-barbital treated rats alone proved to be inactive in LM-and LC-CL production, whereas te combination 1:1 without and with addition of lipid was highly active in both LM-and LC-CL. Ascorbic acid and glutathione as scavengers diminish both LM- and LC-CL in concentrations higher then 10(5). Dimethyl-sulfoxide (DMSO) was ineffective in LM-CL up to concentrations of 0.2 M, the very high concentration of 2 M diminished LM-CL only to 1/3. LC-CL was diminished starting at concentrations of 100 mM and at 2 M only 10% of maximum LC-CL was observed. The trap substance N-t-butyl-a-phenylnitrone (BNP) also diminished LC-CL more effectively than LM-CL. Clearcut differences were revealed by the addition of catalase and superoxide dismutase: both enzymes diminished LM-CL only, without any influence on LC-CL. Hexobarbital, a potent uncoupler of P450, enhances LM-CL fivefold, whereas LC-CL is barely influenced. Aniline (without uncoupling capability) decreased both LM-and LC-CL increasingly with increasing

  4. AM-2201 Inhibits Multiple Cytochrome P450 and Uridine 5′-Diphospho-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Ju-Hyun Kim

    2017-03-01

    Full Text Available AM-2201 is a synthetic cannabinoid that acts as a potent agonist at cannabinoid receptors and its abuse has increased. However, there are no reports of the inhibitory effect of AM-2201 on human cytochrome P450 (CYP or uridine 5′-diphospho-glucuronosyltransferase (UGT enzymes. We evaluated the inhibitory effect of AM-2201 on the activities of eight major human CYPs (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4 and six major human UGTs (1A1, 1A3, 1A4, 1A6, 1A9, and 2B7 enzymes in pooled human liver microsomes using liquid chromatography–tandem mass spectrometry to investigate drug interaction potentials of AM-2201. AM-2201 potently inhibited CYP2C9-catalyzed diclofenac 4′-hydroxylation, CYP3A4-catalyzed midazolam 1′-hydroxylation, UGT1A3-catalyzed chenodeoxycholic acid 24-acyl-glucuronidation, and UGT2B7-catalyzed naloxone 3-glucuronidation with IC50 values of 3.9, 4.0, 4.3, and 10.0 μM, respectively, and showed mechanism-based inhibition of CYP2C8-catalyzed amodiaquine N-deethylation with a Ki value of 2.1 μM. It negligibly inhibited CYP1A2, CYP2A6, CYP2B6, CYP2C19, CYP2D6, UGT1A1, UGT1A4, UGT1A6, and UGT1A9 activities at 50 μM in human liver microsomes. These in vitro results indicate that AM-2201 needs to be examined for potential pharmacokinetic drug interactions in vivo due to its potent inhibition of CYP2C8, CYP2C9, CYP3A4, UGT1A3, and UGT2B7 enzyme activities.

  5. PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

    Science.gov (United States)

    Tedeschi, Henry; James, Joseph M.; Anthony, William

    1963-01-01

    Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

  6. CYP2J2 and CYP2C19 are the major enzymes responsible for metabolism of albendazole and fenbendazole in human liver microsomes and recombinant P450 assay systems.

    Science.gov (United States)

    Wu, Zhexue; Lee, Doohyun; Joo, Jeongmin; Shin, Jung-Hoon; Kang, Wonku; Oh, Sangtaek; Lee, Do Yup; Lee, Su-Jun; Yea, Sung Su; Lee, Hye Suk; Lee, Taeho; Liu, Kwang-Hyeon

    2013-11-01

    Albendazole and fenbendazole are broad-spectrum anthelmintics that undergo extensive metabolism to form hydroxyl and sulfoxide metabolites. Although CYP3A and flavin-containing monooxygenase have been implicated in sulfoxide metabolite formation, the enzymes responsible for hydroxyl metabolite formation have not been identified. In this study, we used human liver microsomes and recombinant cytochrome P450s (P450s) to characterize the enzymes involved in the formation of hydroxyalbendazole and hydroxyfenbendazole from albendazole and fenbendazole, respectively. Of the 10 recombinant P450s, CYP2J2 and/or CYP2C19 was the predominant enzyme catalyzing the hydroxylation of albendazole and fenbendazole. Albendazole hydroxylation to hydroxyalbendazole is primarily mediated by CYP2J2 (0.34 μl/min/pmol P450, which is a rate 3.9- and 8.1-fold higher than the rates for CYP2C19 and CYP2E1, respectively), whereas CYP2C19 and CYP2J2 contributed to the formation of hydroxyfenbendazole from fenbendazole (2.68 and 1.94 μl/min/pmol P450 for CYP2C19 and CYP2J2, respectively, which are rates 11.7- and 8.4-fold higher than the rate for CYP2D6). Correlation analysis between the known P450 enzyme activities and the rate of hydroxyalbendazole and hydroxyfenbendazole formation in samples from 14 human liver microsomes showed that albendazole hydroxylation correlates with CYP2J2 activity and fenbendazole hydroxylation correlates with CYP2C19 and CYP2J2 activities. These findings were supported by a P450 isoform-selective inhibition study in human liver microsomes. In conclusion, our data for the first time suggest that albendazole hydroxylation is primarily catalyzed by CYP2J2, whereas fenbendazole hydroxylation is preferentially catalyzed by CYP2C19 and CYP2J2. The present data will be useful in understanding the pharmacokinetics and drug interactions of albendazole and fenbendazole in vivo.

  7. Magnetic circular dichroism studies on microsomal aryl hydrocarbon hydroxylase: comparison with cytochrome b/sub 5/ and cytochrome P-450/sub cam/

    Energy Technology Data Exchange (ETDEWEB)

    Vickery, L; Salmon, A; Sauer, K

    1975-01-01

    Magnetic circular dichroism spectra are reported for the visible and near ultraviolet spectral regions of liver microsomes from dimethylbenzanthracene-treated rats. The sequential addition of NADH, dithionite, and carbon monoxide enables us to determine contributions to the magnetic circular dichroism by cytochromes b/sub 5/ and P-450, which dominate the spectra. The magnetic circular dichroism of the microsomal preparation is compared with that of purified oxidized and reduced cytochrome b/sub 5/ from pig liver and with the camphor-complexed and camphor-free oxidized, reduced, and reduced carbonmonoxy cytochrome P-450/sub cam/ from Pseudomonas putida. The magnetic circular dichroism spectra of the membrane bound cytochrome b/sub 5/ are similar to those of the purified protein, indicating that little or no alteration in the environment of the heme occurs during the isolation procedure. The soluble bacterial cytochrome P-450/sub cam/ also appears to be a suitable model for microsomal P-450, although differences in the magnetic circular dichroism intensity are observed for the two enzymes. No effect of dimethylbenzanthracene on the magnetic circular dichroism spectra of induced compared to control rat microsomes could be observed.

  8. Proteomic profiling in incubation medium of mouse, rat and human precision-cut liver slices for biomarker detection regarding acute drug-induced liver injury

    NARCIS (Netherlands)

    van Swelm, Rachel P L; Hadi, Mackenzie; Laarakkers, Coby M M; Masereeuw, R.|info:eu-repo/dai/nl/155644033; Groothuis, Geny M M; Russel, Frans G M

    Drug-induced liver injury is one of the leading causes of drug withdrawal from the market. In this study, we investigated the applicability of protein profiling of the incubation medium of human, mouse and rat precision-cut liver slices (PCLS) exposed to liver injury-inducing drugs for biomarker

  9. Stereospecificity (ST) of the microsomal ethanol oxidizing system (MEOS)

    International Nuclear Information System (INIS)

    Alderman, J.; Kato, S.; Lasker, J.; Lieber, C.S.

    1987-01-01

    The ST of MEOS for the ethanol 1R hydrogen has been variously reported as absolute, partial or absent, with free radical involvement postulated in the latter case. To determine both the ST of MEOS and the participation of free radicals in the reaction, they investigated MEOS ST using 1R[1- 3 H] ethanol as substrate. ST is expressed as the fraction of 3 H labeling in acetaldehyde formed, relative to that in ethanol, and ranges from 0.5 to 0. Partial ST was observed using liver microsomes from both rats and hamsters; it significantly decreased after ethanol feeding. 0.1 mM desferrioxamine (dfx) did not increase ST in any of these microsomal preparations while ferric EDTA decreased it, suggesting that ethanol treatment induces a cytochrome P-450 with lower ST rather than increasing free radical involvement. This is supported by a virtual absence of ST observed in a reconstituted system containing purified hamster P-450/sub ALC/, a liver cytochrome P-450 isozyme induced in hamsters by ethanol treatment. Their results indicate that, unlike other enzymes that oxidize ethanol, MEOS has only partial ST. Thus, ST alone cannot be used as an index of free radical involvement but, when evaluated with the response of ST to dfx, it indicated that MEOS is unlikely to involve free radical attack on ethanol in solution

  10. Novel metabolic pathways for linoleic and arachidonic acid metabolism.

    Science.gov (United States)

    Moghaddam, M; Motoba, K; Borhan, B; Pinot, F; Hammock, B D

    1996-08-13

    Mouse liver microsomes oxidized linoleic acid to form 9,10- or 12,13-epoxyoctadecenoate. These monoepoxides were subsequently hydrolyzed to their corresponding diols in the absence of the microsomal epoxide hydrolase inhibitor, 1,2-epoxy-3,3,3-trichloropropane. Furthermore, both 9,10- and 12,13-epoxyoctadecenoates were oxidized to diepoxyoctadecanoate at apparently identical rates by mouse liver microsomal P-450 epoxidation. Both epoxyoctadecanoates and diepoxyoctadecanoates were converted to tetrahydrofuran-diols by microsomes. Tetrahydroxides of linoleate were produced as minor metabolites. Arachidonic acid was metabolized to epoxyeicosatrienoates, dihydroxyeicosatrienoates, and monohydroxyeicosatetraenoates by the microsomes. Microsomes prepared from clofibrate (but not phenobarbital) -treated mice exhibited much higher production rates for epoxyeicosatrienoates and vic-dihydroxyeicosatrienoates. This indicated an induction of P-450 epoxygenase(s) and microsomal epoxide hydrolase in mice by clofibrate and not by phenobarbital. Incubation of synthetic epoxyeicosatrienoates with microsomes led to the production of diepoxyeicosadienoates. Among chemically generated diepoxyeicosadienoate isomers, three of them possessing adjacent diepoxides were hydrolyzed to their diol epoxides which cyclized to the corresponding tetrahydrofuran-diols by microsomes as well as soluble epoxide hydrolase at a much higher rate. Larger cyclic products from non-adjacent diepoxides were not observed. The results of our in vitro experiments suggest that linoleic and arachidonic acid can be metabolized to their tetrahydrofuran-diols by two consecutive microsomal cytochrome P-450 epoxidations followed by microsomal or soluble epoxide hydrolase catalyzed hydrolysis of the epoxides. Incubation experiments with the S-9 fractions indicate that the soluble epoxide hydrolase is more important in this conversion. This manuscript is the first report of techniques for the separation and

  11. A novel method of mouse ex utero transplantation of hepatic progenitor cells into the fetal liver

    International Nuclear Information System (INIS)

    Shikanai, Mima; Asahina, Kinji; Iseki, Sachiko; Teramoto, Kenichi; Nishida, Tomohiro; Shimizu-Saito, Keiko; Ota, Masato; Eto, Kazuhiro; Teraoka, Hirobumi

    2009-01-01

    Avoiding the limitations of the adult liver niche, transplantation of hepatic stem/progenitor cells into fetal liver is desirable to analyze immature cells in a hepatic developmental environment. Here, we established a new monitor tool for cell fate of hepatic progenitor cells transplanted into the mouse fetal liver by using ex utero surgery. When embryonic day (ED) 14.5 hepatoblasts were injected into the ED14.5 fetal liver, the transplanted cells expressed albumin abundantly or α-fetoprotein weakly, and contained glycogen in the neonatal liver, indicating that transplanted hepatoblasts can proliferate and differentiate in concord with surrounding recipient parenchymal cells. The transplanted cells became mature in the liver of 6-week-old mice. Furthermore, this method was applicable to transplantation of hepatoblast-like cells derived from mouse embryonic stem cells. These data indicate that this unique technique will provide a new in vivo experimental system for studying cell fate of hepatic stem/progenitor cells and liver organogenesis.

  12. Studies on estradiol-2/4-hydroxylase activity in rat brain and liver

    International Nuclear Information System (INIS)

    Theron, C.N.

    1985-03-01

    A sensitive and specific radio-enzymatic assay was used to study estradiol-2/4-hydroxylase activity in rat liver microsomes and in microsomes obtained from 6 discrete brain areas of the rat. Kinetic parameters were determined for these enzyme activities. The effects of different P-450 inhibitors on estradiol-2/4-hydroxylase activity in brain and liver microsomes were also studied. In both organs these enzyme activities were found to be located mainly in the microsomal fraction and were inhibited by the 3 P-450 inhibitors tested. The hepatic estradiol-2/4-hydroxylase activity in adult male rats was significantly higher than that of females, but the enzyme activity in the brain did not exhibit a similar sex difference. Furthermore, estradiol-2/4-hydroxylase activity in rat liver was strongly induced by phenobarbitone treatment, but not in the brain. The phenobarbitone-induced activity in male and female rats exhibited significant kinetic differences. In female rats sexual maturation was associated with significant changes in the apparent Km of estradiol-2/4-hydroxylases in the liver and hypothalamus. Evidence was found that the in vitro estradiol-2/4-hydroxylase activity in rat brain and liver is due to more than one form of microsomal P-450. Kinetic studies showed important differences between the estradiol-2/4-hydroxylase activities in the hippocampus and hypothalamus. Significant differences in estradiol-2/4-hydroxylase activities were observed in the 6 brain areas studied, with the hippocampus showing the highest, and the hypothalamus the lowest activity at all developmental stages in both male and female rats

  13. Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

    Science.gov (United States)

    Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

    1982-01-01

    The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity. PMID:7103489

  14. Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

    OpenAIRE

    Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

    1982-01-01

    The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

  15. Lipid peroxidation in microsomes of murine bone marrow after low-dose γ-irradiation

    International Nuclear Information System (INIS)

    Schwenke, K.; Coslar, S.; Muehlensiepen, H.; Altman, K.I.; Feinendegen, L.E.

    1994-01-01

    The principal aim of the study was to investigate the effect of low-dose γ-irradiation on lipid peroxidation (LPO) in murine bone marrow. To this end, the degree of LPO in suspensions of microsomes of murine bone marrow cells (BMC) was determined in terms of malondialdehyde (MDA) formation after whole-body or in vitro exposure to various doses of γ-radiation. These effects were compared to some extent with similar effects in liver and spleen preparations. As to the effect of γ-irradiation on LPO in BMC, the response depends on the dose level and on whether whole-body or in vitro exposures are involved. Whole-body irradiation did not result in an increase in LPO in BMC microsomes, even at such high doses as 15 Gy, although hepatic microsomes showed a marked increase. In contrast, in vitro irradiation of BMC microsomes with 0.1, 10 and 50 Gy brought about an increase in LPO. This increase was already significant (P < 0.05) at 0.1 Gy following a post-irradiation incubation and substantial at 50 Gy, even without subsequent incubation. The results show that low doses of γ-irradiation are able to induce an elevation of LPO in murine BMC microsomes, but only after in vitro irradiation. In the case of whole-body irradiation cellular radical scavengers and other metabolic reactions may prevent a measurable increase in LPO. This is partly illustrated by the case of vitamin-E deficiency, where a substantial increase in LPO in BMC microsomes is observed even without γ-irradiation in comparison with euvitaminotic mice because normally occurring radicals are not scavenged sufficiently. (orig.)

  16. [125I]2-iodo-3,7,8-trichlorodibenzo-p-dioxin-binding species in mouse liver induced by agonists for the Ah receptor: Characterization and identification

    International Nuclear Information System (INIS)

    Poland, A.; Teitelbaum, P.; Glover, E.

    1989-01-01

    The admininistration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to C57BL/6J mice produces a dose-related increase in the hepatic uptake of [ 125 I]2-iodo-3,7,8-trichlorodibenzo-p-dioxin ([ 125 I]Cl3DpD) in vivo and the binding of the radioligand to liver homogenate in vitro. The TCDD-induced hepatic binding species was found to be predominantly in the microsomal fraction and was inactivated by heating at 60 degree, trypsin, and mercurials. The TCDD-induced binding species was found to have an apparent equilibrium dissociation constant, KD, ([ 125 I]Cl3DpD) of 56 +/- 16 nM and a pool size, Bmax, of 22 +/- 5 nmol/g of liver. A number of halogenated dibenzo-p-dioxins, biphenyls, and polycyclic aromatic hydrocarbons compete with [ 125 I]Cl3DpD binding to this species; all are aromatic and planar. The distinctive profile of this binding species, a protein of large pool size induced in the microsomal fraction of liver but not other tissues and induced by agonists for the Ah receptor, suggested that this moiety might be cytochrome P3-450. The coincidence of the major microsomal species covalently labeled with the photoaffinity ligand [ 125 I]2-iodo-3-azido-7,8-dibromodibenzo-p-dioxin and that immunochemically stained with polyclonal antiserum that binds to cytochrome P3-450 confirms this hypothesis. This is a novel role for a cytochrome P-450 isozyme, as an induced sequestration site that enhances the hepatic localization of the agonist drug

  17. Discrimination of tumorigenic triazole conazoles from phenobarbital by transcriptional analyses of mouse liver gene expression

    Science.gov (United States)

    Conazoles are fungicides used to control fungal growth in environmental settings and to treat humans with fungal infections. Mouse hepatotumorigenic conazoles display many of the same hepatic toxicologic responses as the mouse liver carcinogen phenobarbital (PB): constitutive and...

  18. Microsomal protein synthesis inhibition: an early manifestation of gentamicin nephrotoxicity

    International Nuclear Information System (INIS)

    Bennett, W.M.; Mela-Riker, L.M.; Houghton, D.C.; Gilbert, D.N.; Buss, W.C.

    1988-01-01

    Aminoglycoside antibiotics achieve bacterial killing by binding to bacterial ribosomes and inhibiting protein synthesis. To examine whether similar mechanisms could be present in renal tubular cells prior to the onset of overt proximal tubular necrosis due to these drugs, we isolated microsomes from Fischer rats given 20 mg/kg gentamicin every 12 h subcutaneously for 2 days and from vehicle-injected controls. Concomitant studies of renal structure, function, and mitochondrial respiration were carried out. [3H]leucine incorporation into renal microsomes of treated animals was reduced by 21.9% (P less than 0.01), whereas brain and liver microsomes from the same animals were unaffected. Gentamicin concentration in the renal microsomal preparation was 56 micrograms/ml, a value 7- to 10-fold above concentrations necessary to inhibit bacterial growth. Conventional renal function studies were normal (blood urea, serum creatinine, creatinine clearance). Treated animals showed only a mild reduction of inulin clearance, 0.71 compared with 0.93 ml.min-1.100 g-1 in controls (P less than 0.05), and an increase in urinary excretion of N-acetylglucosaminidase of 20 compared with 14.8 units/l (P less than 0.05). Renal slice transport of p-aminohippuric acid, tetraethylammonium, and the fractional excretion of sodium were well preserved. There was no evidence, as seen by light microscopy, of proximal tubular necrosis. Mitochondrial cytochrome concentrations were normal and respiratory activities only slightly reduced. Processes similar to those responsible for bacterial killing could be involved in experimental gentamicin nephrotoxicity before overt cellular necrosis

  19. The effect of fenbuconazole on cell proliferation and enzyme induction in the liver of female CD1 mice

    International Nuclear Information System (INIS)

    Juberg, Daland R.; Mudra, Daniel R.; Hazelton, George A.; Parkinson, Andrew

    2006-01-01

    Fenbuconazole, a triazole fungicide, has been associated with an increase in the incidence of liver adenomas in female mice following long-term dietary exposure. The aim of this study was to evaluate whether the mode of action for liver tumor formation by fenbuconazole is similar to that of phenobarbital. Treatment of CD1 mice with 0, 20, 60, 180 or 1300 ppm fenbuconazole for up to 4 weeks caused a dose-dependent increase in liver weight that was associated with centrilobular hepatocellular hypertrophy, cytoplasmic eosinophilia and panlobular hepatocellular vacuolation, as well as an initial increase in the cell proliferation labeling index. Fenbuconazole also caused a dose-dependent increase in liver microsomal cytochromes b 5 and P450 and the levels of immunoreactive CYP2B10 and its associated activity 7-pentoxyresorufin O-dealkylation (PROD). Treatment of mice with 1000 ppm phenobarbital elicited the same effects as treatment of mice with 1300 ppm fenbuconazole, except that phenobarbital was more effective than fenbuconazole at inducing PROD activity, even though fenbuconazole induced CYP2B10 to the same extent as did phenobarbital. This difference was attributed to the ability of fenbuconazole to bind tightly to CYP2B10 and partially mask its catalytic activity in liver microsomes, which is characteristic of several azole-containing drugs. All hepatocellular changes and induced enzyme activity returned to control levels within 4 weeks of discontinuing treatment with fenbuconazole or phenobarbital, indicating that the observed changes were fully reversible. We conclude that fenbuconazole is a phenobarbital-type inducer of mouse liver cytochrome P450, and the mode of action by which fenbuconazole induces liver adenomas in mice is similar to that of phenobarbital

  20. A physiologically based pharmacokinetic model for ethylene oxide in mouse, rat, and human.

    Science.gov (United States)

    Fennell, T R; Brown, C D

    2001-06-15

    Ethylene oxide (EO) is widely used as a gaseous sterilant and industrial intermediate and is a direct-acting mutagen and carcinogen. The objective of these studies was to develop physiologically based pharmacokinetic (PB-PK) models for EO to describe the exposure-tissue dose relationship in rodents and humans. We previously reported results describing in vitro and in vivo kinetics of EO metabolism in male and female F344 rats and B6C3F1 mice. These studies were extended by determining the kinetics of EO metabolism in human liver cytosol and microsomes. The results indicate enzymatically catalyzed GSH conjugation via cytosolic glutathione S-transferase (cGST) and hydrolysis via microsomal epoxide hydrolase (mEH) occur in both rodents and humans. The in vitro kinetic constants were scaled to account for cytosolic (cGST) and microsomal (mEH) protein content and incorporated into PB-PK descriptions for mouse, rat, and human. Flow-limited models adequately predicted blood and tissue EO levels, disposition, and elimination kinetics determined experimentally in rats and mice, with the exception of testis concentrations, which were overestimated. Incorporation of a diffusion-limited description for testis improved the ability of the model to describe testis concentrations. The model accounted for nonlinear increases in blood and tissue concentrations that occur in mice on exposure to EO concentrations greater than 200 ppm. Species differences are predicted in the metabolism and exposure-dose relationship, with a nonlinear relationship observed in the mouse as a result of GSH depletion. These models represent an essential step in developing a mechanistically based EO exposure-dose-response description for estimating human risk from exposure to EO. Copyright 2001 Academic Press.

  1. Isolation and structural elucidation of tiamulin metabolites formed in liver microsomes of pigs.

    Science.gov (United States)

    Lykkeberg, Anne Kruse; Cornett, Claus; Halling-Sørensen, Bent; Hansen, Steen Honoré

    2006-09-18

    Although the antimicrobial tiamulin is extensively metabolized in pigs, the metabolism is not well investigated. In this work the NADPH dependent metabolism of tiamulin in liver microsomes from pigs has been studied. The tiamulin metabolites formed in the incubations were analysed using LC-MS, and three major metabolites were isolated using solid phase extraction and preparative HPLC. The final structure elucidations were performed by tandem mass spectrometry and (1)H and (13)C NMR. The structures of the metabolites were found to be 2beta-hydroxy-tiamulin, 8alpha-hydroxy-tiamulin and N-deethyl-tiamulin. In addition, the LC-MS chromatograms revealed two other minor metabolites. From their chromatography and from MS(2) analysis the structures were estimated to be 2beta-hydroxy-N-deethyl-tiamulin and 8alpha-hydroxy-N-deethyl-tiamulin, but the structures were not confirmed by NMR. In these studies approximately 20% of tiamulin was deethylated, 10% was hydroxylated in the 2beta-position and 7% was hydroxylated in the 8alpha-position. About 40% of tiamulin was metabolized during the incubation conditions used. The protein precipitation in the incubations was performed using perchloric acid, and the preparative purification was performed under alkaline conditions. Therefore, the stability of the metabolites under these conditions was studied. The metabolites were found to be stable in the acid solution, but under alkaline conditions, particularly at room temperature, the stability of especially 8alpha-hydroxy-tiamulin was considerably reduced (40% loss after 1 week).

  2. CAR-mediated repression of Foxo1 transcriptional activity regulates the cell cycle inhibitor p21 in mouse livers

    International Nuclear Information System (INIS)

    Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O.

    2014-01-01

    Highlights: • CAR activation decreased the level of Foxo1 in mouse livers. • CAR activation decreased the level of p21 in mouse livers. • CAR activation inhibited Foxo1 transcriptional activity in mouse livers. - Abstract: 1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), an agonist of constitutive androstane receptor (CAR), is a well-known strong primary chemical mitogen for the mouse liver. Despite extensive investigation of the role of CAR in the regulation of cell proliferation, our knowledge of the intricate mediating mechanism is incomplete. In this study, we demonstrated that long-term CAR activation by TCPOBOP increased liver-to-body weight ratio and decreased tumour suppressor Foxo1 expression and transcriptional activity, which were correlated with reduced expression of genes regulated by Foxo1, including the cell-cycle inhibitor Cdkn1a(p21), and upregulation of the cell-cycle regulator Cyclin D1. Moreover, we demonstrated the negative regulatory effect of TCPOBOP-activated CAR on the association of Foxo1 with the target Foxo1 itself and Cdkn1a(p21) promoters. Thus, we identified CAR-mediated repression of cell cycle inhibitor p21, as mediated by repression of FOXO1 expression and transcriptional activity. CAR-FOXO1 cross-talk may provide new opportunities for understanding liver diseases and developing more effective therapeutic approaches to better drug treatments

  3. Inhibitory effect of gene combination in a mouse model of colon cancer with liver metastasis.

    Science.gov (United States)

    DU, Tong; Niu, Hongxin

    2014-09-01

    The aim of the present study was to establish an animal liver metastasis model with human colon cancer and investigate the inhibitory effect of the wild type (WT) p53 gene combined with thymidine kinase/ganciclovir (TK/GCV) and cytosine deaminase/5-fluorocytosine (CD/5-FC) systems on liver metastasis of colon cancer. A nude mouse liver metastasis model with human colon cancer was established via a spleen cultivation method. A total of 32 nude mice were randomly divided into four groups, each group with eight mice. Group 1 mice received splenic injections of SW480 cells (control group), while group 2 mice were injected with SW480/p53 cells in the spleen. Group 3 mice were administered splenic injections of SW480/TK-CD cells, and GCV and 5-FC were injected into the abdominal cavity. Finally, group 4 mice received splenic injections of SW480/p53 cells mixed in equal proportion with SW480/TK-CD cells, as well as GCV and 5-FC injections in the abdominal cavity. These cells described were constructed in our laboratory and other laboratories. The number of liver metastatic tumors, the liver metastasis rate, conventional pathology, electron microscopy and other indicators in the nude mice of each group were compared and observed. The nude mouse liver metastasis model with human colon cancer was successfully established; the liver metastasis rate of the control group was 100%. The results demonstrated that the rate of liver metastasis in the nude mice in each treatment group decreased, as well as the average number of liver metastatic tumors. Furthermore, the effect of the treatment group with genetic combination (group 4) was the most effective, demonstrating that WTp53 had a synergistic effect with TK/GCV and CD/5-FC. Therefore, the present study successfully established a mouse model of liver metastasis with colon cancer by injecting human colon cancer cells in the spleen. Combined gene therapy was shown to have a synergistic effect, which effectively inhibited the

  4. [The effect of alpha-tocopherol and ionol on the physical structure of the membranes of rat liver microsomes under conditions of antioxidant insufficiency].

    Science.gov (United States)

    Gubskiĭ, Iu I; Boldeskul, A E; Primak, R G; Zadorina, O V

    1989-01-01

    Physiochemical conformity of the alpha-tocopherol interaction with hepatic microsomal membranes has been studied by means of fluorescent probes (pyrene and 1-anilinonaphthalene-8-sulphonate). The microsomal membrane microviscosity is shown to sharply decrease under conditions of the antioxidant deficiency with vitamin E expelled into animals normalizes microviscosity, but feebly influences the microsomal surface charge. Microcalorimetry has been used to establish that penetration of tocopherol into microsomal membranes was accompanied by the exothermic effect.

  5. A mouse radiation-induced liver disease model for stereotactic body radiation therapy validated in patients with hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Wu, Zhi-Feng; Zhang, Jian-Ying; Shen, Xiao-Yun; Gao, Ya-Bo; Hu, Yong; Zeng, Zhao-Chong; Zhou, Le-Yuan

    2016-01-01

    Purpose: Lower radiation tolerance of the whole liver hinders dose escalations of stereotactic body radiation therapy (SBRT) in hepatocellular carcinoma (HCC) treatment. This study was conducted to define the exact doses that result in radiation-induced liver disease (RILD) as well as to determine dose constraints for the critical organs at risk (OARs) in mice; these parameters are still undefined in HCC SBRT. Methods: This study consisted of two phases. In the primary phase, mice treated with helical tomotherapy-based SBRT were stratified according to escalating radiation doses to the livers. The pathological differences, signs [such as mouse performance status (MPS)], and serum aspartate aminotransferase (AST)/alanine aminotransferase (ALT)/albumin levels were observed. Radiation-induced disease severities of the OARs were scored using systematic evaluation standards. In the validation phase in humans, 13 patients with HCC who had undergone radiotherapy before hepatectomy were enrolled to validate RILD pathological changes in a mouse study. Results: The evaluation criteria of the mouse liver radiotherapy-related signs were as follows: MPS ≥ 2.0 ± 0.52, AST/ALT ≥ 589.2 ± 118.5/137.4 ± 15.3 U/L, serum albumin ≤ 16.8 ± 2.29 g/L. The preliminary dose constraints of the OARs were also obtained, such as those for the liver (average dose ≤ 26.36 ± 1.71 Gy) and gastrointestinal tract (maximum dose ≤ 22.63 Gy). Mouse RILD models were able to be developed when the livers were irradiated with average doses of ≥31.76 ± 1.94 Gy (single fraction). RILD pathological changes in mice have also been validated in HCC patients. Conclusions: Mouse RILD models could be developed with SBRT based on the dose constraints for the OARs and evaluation criteria of mouse liver radiotherapy-related signs, and the authors’ results favor the study of further approaches to treat HCC with SBRT.

  6. Phenobarbital induces cell cycle transcriptional responses in mouse liver humanized for constitutive androstane and pregnane x receptors.

    Science.gov (United States)

    Luisier, Raphaëlle; Lempiäinen, Harri; Scherbichler, Nina; Braeuning, Albert; Geissler, Miriam; Dubost, Valerie; Müller, Arne; Scheer, Nico; Chibout, Salah-Dine; Hara, Hisanori; Picard, Frank; Theil, Diethilde; Couttet, Philippe; Vitobello, Antonio; Grenet, Olivier; Grasl-Kraupp, Bettina; Ellinger-Ziegelbauer, Heidrun; Thomson, John P; Meehan, Richard R; Elcombe, Clifford R; Henderson, Colin J; Wolf, C Roland; Schwarz, Michael; Moulin, Pierre; Terranova, Rémi; Moggs, Jonathan G

    2014-06-01

    The constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) are closely related nuclear receptors involved in drug metabolism and play important roles in the mechanism of phenobarbital (PB)-induced rodent nongenotoxic hepatocarcinogenesis. Here, we have used a humanized CAR/PXR mouse model to examine potential species differences in receptor-dependent mechanisms underlying liver tissue molecular responses to PB. Early and late transcriptomic responses to sustained PB exposure were investigated in liver tissue from double knock-out CAR and PXR (CAR(KO)-PXR(KO)), double humanized CAR and PXR (CAR(h)-PXR(h)), and wild-type C57BL/6 mice. Wild-type and CAR(h)-PXR(h) mouse livers exhibited temporally and quantitatively similar transcriptional responses during 91 days of PB exposure including the sustained induction of the xenobiotic response gene Cyp2b10, the Wnt signaling inhibitor Wisp1, and noncoding RNA biomarkers from the Dlk1-Dio3 locus. Transient induction of DNA replication (Hells, Mcm6, and Esco2) and mitotic genes (Ccnb2, Cdc20, and Cdk1) and the proliferation-related nuclear antigen Mki67 were observed with peak expression occurring between 1 and 7 days PB exposure. All these transcriptional responses were absent in CAR(KO)-PXR(KO) mouse livers and largely reversible in wild-type and CAR(h)-PXR(h) mouse livers following 91 days of PB exposure and a subsequent 4-week recovery period. Furthermore, PB-mediated upregulation of the noncoding RNA Meg3, which has recently been associated with cellular pluripotency, exhibited a similar dose response and perivenous hepatocyte-specific localization in both wild-type and CAR(h)-PXR(h) mice. Thus, mouse livers coexpressing human CAR and PXR support both the xenobiotic metabolizing and the proliferative transcriptional responses following exposure to PB.

  7. Ethosuximide: liver enzyme induction and D-glucaric acid excretion.

    Science.gov (United States)

    Gilbert, J C; Scott, A K; Galloway, D B; Petrie, J C

    1974-06-01

    1 A study has been carried out to determine if ethosuximide induces liver enzymes. 2 Ethosuximide did not affect the urinary excretion of D-glucaric acid by healthy adult subjects nor was the mean daily D-glucaric acid excretion of three epileptic children on long term ethosuximide therapy different from that of three matched controls. 3 Ethosuximide (10 mg/kg or 50 mg/kg daily) did not influence D-glucaric acid excretion or liver microsomal protein and cytochrome P450 contents of guinea pigs but at a dose of 100 mg/kg daily in rats it increased liver microsomal protein and cytochrome P450 without altering D-glucaric acid excretion. 4 These results suggest that at anticonvulsant doses ethosuximide is unlikely to induce liver enzymes. The precise relationship between D-glucaric acid excretion and liver enzyme induction remains in doubt.

  8. T cell progenitors in the mouse fetal liver

    International Nuclear Information System (INIS)

    Rabinowich, H.; Umiel, T.; Globerson, A.

    1983-01-01

    Fourteen-day mouse fetal liver was found to contain cells capable of giving rise to T as well as B cell functions. The experimental system consisted of congenic C3H/DiSn and (C3H/DiSn X C3H.SW)F1 lethally irradiated (900 R) mice reconstituted with C3H/DiSn fetal liver or bone marrow cells. Assays included thyroid allograft rejection as well as in vitro measurement of reactivity to phytohemagglutinin (PHA) and concanavalin A (Con A) and in a mixed lymphocyte culture (MLC) system in spleen, lymph node, and thymus cells. The fetal liver chimeras were found to become as capable as the bone marrow chimeras in responding in these various assays. The T cell responses lagged behind the responses to the B cell mitogens dextran sulfate (DXS) and lipopolysaccharide (LPS) (30 days after reconstitution, as compared with 14 days for DXS and 21 for LPS). The reacting cells were of the donor genotype, as revealed after treatment with C3H/DiSn (H-2k) anti-C3H.SW (H-2b) congenic sera. T cell responses were not manifest in thymectomized (TX) chimeras. Hence, the liver seems to contain cells capable of developing into T cell lineages in a thymus-dependent process

  9. Manifestation of Non-Alcoholic Fatty Liver Disease/Non-Alcoholic Steatohepatitis in Different Dietary Mouse Models

    Directory of Open Access Journals (Sweden)

    Vera HI Fengler

    2016-05-01

    Full Text Available Non-alcoholic fatty liver disease (NAFLD and non-alcoholic steatohepatitis (NASH, which are usually associated with obesity and metabolic syndrome, are considerable health and economic issues due to the rapid increase of their prevalence in Western society. Histologically, the diseases are characterised by steatosis, hepatic inflammation, and if further progressed, fibrosis. Dietary-induced mouse models are widely used in investigations of the development and progression of NAFLD and NASH; these models attempt to mimic the histological and metabolic features of the human diseases. However, the majority of dietary mouse models fail to reflect the whole pathophysiological spectrum of NAFLD and NASH. Some models exhibit histological features similar to those seen in humans while lacking the metabolic context, while others resemble the metabolic conditions leading to NAFLD in humans but fail to mimic the whole histological spectrum, including progression from steatosis to liver fibrosis, and thus fail to mimic NASH. This review summarises the advantages and disadvantages of the different dietary-induced mouse models of NAFLD and NASH, with a focus on the genetic background of several commonly used wild-type mouse strains as well as gender and age, which influence the development and progression of these liver diseases.

  10. Binding of bilirubin and its structural analogues to hepatic microsomal bilirubin UDP glucuronyltransferase

    International Nuclear Information System (INIS)

    Vanstapel, F.; Blanckaert, N.

    1987-01-01

    Hepatic glucuronidation of the asymmetrical natural bilirubin molecule results in formation of two different positional isomers, bilirubin C-8 monoglucuronide and bilirubin C-12 monoglucuronide. In view of the existence of multiple isoforms of UDPglucuronyltransferase, which is the microsomal enzyme system responsible for bilirubin esterification, the authors performed kinetic analysis of microsomal glucuronidation of bilirubin and a number of its structural congeners to determine whether synthesis of the two monoglucuronide isomers involved two distinct substrate-binding sites or reflected two different modes of binding to a single catalytic site. Both isomers were found in all tested species (man, rat, guinea pig, sheep), but there were marked species differences in the C-8/C-12 ratio of monoglucuronide found in bile or formed by liver microsomes. Correspondence between in vivo and in vitro results for such regioselectivity of glucuronidation was excellent in each species. On the basis of these results of kinetic analysis of bilirubin esterification at variable pigment substrate concentrations and inhibition studies with alternative substrates, the authors postulate that both natural monoglucuronide isomers are synthesized at a single binding site. Possible mechanisms responsible for the markedly regioselective esterification of bilirubin by rat and sheep liver were investigated by study of glucuronidation of selected structural analgoues of the pigment. Collectively, their findings suggest that the molecular from(s) of bilirubin able to engage in catalytically effective binding to UDPglucuronyltransferase does (do) not correspond with intramolecularly hydrogen-bonded conformers and that the nature of the β-substituents of the outer pyrromethenone rings is a key determinant of glucuronidation rate

  11. Induction of phosphatidylcholine biosynthesis via CDPcholine pathway in lung and liver of rats following intratracheal administration of DDT and endosulfan

    International Nuclear Information System (INIS)

    Narayan, S.; Dani, H.M.; Misra, U.K.

    1989-01-01

    The induction of phosphatidylcholine (PC) biosynthesis via the CDPcholine pathway in lung and liver of rats has been shown following the intratracheal administration of 1,1,1-trichloro-2m2-bis(p-chlorophenyl) ethane (DDT) (5 mg/100 g body weight) and endosulfan (1 mg/100 g body weight) for 3 days. Controls received only the vehicle solution (groundnut oil, 0.1 m1/100 g body weight). The treatment of DDT and endosulfan significantly increased the PC contents and the incorporation of radioactive [methyl-3H]choline into PC of lung and liver microsomes. The incorporation of radioactive [methyl-14C]methionine into microsomal PC of lung and liver was not affected significantly by treatment with either of the insecticides. 1,4,5,6,7-hexachloro-5-norbornene-2,3-dimethano cyclic sulfite (endosulfan) administration significantly increased the activity of choline kinase and phosphocholine cytidylyltransferase (both cytosolic and microsomal) of lung, whereas DDT increased the activity of only latter. In liver, both DDT and endosulfan administration significantly increased the activity of choline kinase and phosphocholine cytidylyltransferase (both cytosolic and microsomal). However, the activity of phosphocholinetransferase was not affected in both lung and liver microsomes of rats treated with these insecticides. The PC precursor pool sizes, choline and phosphorylcholine, of lung and liver tissues were not altered by DDT and endosulfan treatments. The present results suggest that the increased level of PC and incorporation of radioactive [methyl-3H]choline into microsomal PC could be the result of increased activity of choline kinase and phosphocholine cytidylyltransferase of lung and liver of rats following intratracheal administration of DDT and endosulfan

  12. Targeted induction of interferon-λ in humanized chimeric mouse liver abrogates hepatotropic virus infection.

    Science.gov (United States)

    Nakagawa, Shin-ichiro; Hirata, Yuichi; Kameyama, Takeshi; Tokunaga, Yuko; Nishito, Yasumasa; Hirabayashi, Kazuko; Yano, Junichi; Ochiya, Takahiro; Tateno, Chise; Tanaka, Yasuhito; Mizokami, Masashi; Tsukiyama-Kohara, Kyoko; Inoue, Kazuaki; Yoshiba, Makoto; Takaoka, Akinori; Kohara, Michinori

    2013-01-01

    The interferon (IFN) system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV) and hepatitis B virus (HBV). This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC). Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs) in the livers and sera of these humanized chimeric mice. Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level) of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic) tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS) and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1), suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection.

  13. In vitro formation of metabolic-intermediate cytochrome P450 complexes in rabbit liver microsomes by tiamulin and various macrolides.

    Science.gov (United States)

    Carletti, Monica; Gusson, Federica; Zaghini, Anna; Dacasto, Mauro; Marvasi, Luigi; Nebbia, Carlo

    2003-01-01

    Tiamulin and a number of macrolides were evaluated as to their ability in forming metabolic-intermediate (MI) complexes with cytochrome P450 in liver microsomes from rabbits bred for meat production. Complex formation, which occurred only in preparations where the expression of P450 3A was increased as the result of rifampicin pre-treatment and with different kinetics, was in the order tiamulin > erythromycin > TAO approximately roxithromycin approximately tylosin and did not take place with tilmicosin and spiramycin. Most of the tested compounds underwent an oxidative N-dealkylation and a good relationship could be found between the rate of N-dealkylase activity in induced preparations and the aptitude in generating MI complexes. Although the results from in vitro studies should be interpreted with caution, it is suggested that the potential for in vivo drug interactions also exists in the rabbit for tiamulin and for four out of the six tested macrolides.

  14. Clinical features and effect of antiviral therapy on anti-liver/kidney microsomal antibody type 1 positive chronic hepatitis C.

    Science.gov (United States)

    Ferri, Silvia; Muratori, Luigi; Quarneti, Chiara; Muratori, Paolo; Menichella, Rita; Pappas, Georgios; Granito, Alessandro; Ballardini, Giorgio; Bianchi, Francesco B; Lenzi, Marco

    2009-06-01

    Anti-liver/kidney microsomal antibody type 1 (anti-LKM1), a serological marker of type 2 autoimmune hepatitis, is also detected in a small proportion of patients with hepatitis C. This study aimed to evaluate clinical features and effect of antiviral therapy in patients with hepatitis C who are anti-LKM1 positive. Sixty consecutive anti-LKM1 positive and 120 age and sex-matched anti-LKM1 negative chronic hepatitis C patients were assessed at diagnosis and during follow-up. Of these, 26 anti-LKM1 positive and 72 anti-LKM1 negative received antiviral therapy. Anti-LKM1 was detected by indirect immunofluorescence and immunoblot. Number of HCV-infected hepatocytes and intrahepatic CD8+ lymphocytes was determined by immunohistochemistry. At diagnosis anti-LKM1 positive patients had higher IgG levels and more intrahepatic CD8+ lymphocytes (p 0.022 and 0.046, respectively). Viral genotypes distribution and response to therapy were identical. Hepatic flares during antiviral treatment only occurred in a minority of patients in concomitance with anti-LKM1 positivity. Immune system activation is more pronounced in anti-LKM1 positive patients with hepatitis C, possibly representing the expression of autoimmune mechanisms of liver damage. Antiviral treatment is as beneficial in these patients as in anti-LKM1 negative patients, and the rare necroinflammatory flares are effectively controlled by corticosteroids, allowing subsequent resumption of antiviral therapy.

  15. Pharmacokinetic study of isocorynoxeine metabolites mediated by cytochrome P450 enzymes in rat and human liver microsomes.

    Science.gov (United States)

    Zhao, Lizhu; Zang, Bin; Qi, Wen; Chen, Fangfang; Wang, Haibo; Kano, Yoshihiro; Yuan, Dan

    2016-06-01

    Isocorynoxeine (ICN) is one of the major bioactive tetracyclic oxindole alkaloids found in Uncaria rhynchophylla (Miq.) Jacks. that is widely used for the treatment of hypertension, vascular dementia, and stroke. The present study was undertaken to assess the plasma pharmacokinetic characteristics of major ICN metabolites, and the role of simulated gastric and intestinal fluid (SGF and SIF), human and rat liver microsomes (HLMs and RLMs), and seven recombinant human CYP enzymes in the major metabolic pathway of ICN. A rapid, sensitive and accurate UHPLC/Q-TOF MS method was validated for the simultaneous determination of ICN and its seven metabolites in rat plasma after oral administration of ICN at 40mg/kg. It was found that 18.19-dehydrocorynoxinic acid (DCA) and 5-oxoisocorynoxeinic acid (5-O-ICA) were both key and predominant metabolites, rather than ICN itself, due to the rapid and extensive metabolism of ICN in vivo. The further study indicated that ICN was mainly metabolized in human or rat liver, and CYPs 2C19, 3A4 and 2D6 were the major enzymes responsible for the biotransformation of ICN to DCA and 5-O-ICA in human. These findings are of significance in understanding of the pharmacokinetic nature of tetracyclic oxindole alkaloids, and provide helpful information for the clinical co-administration of the herbal preparations containing U. rhynchophylla with antihypertensive drugs that are mainly metabolized by CYP3A4 and CYP2C19. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Monkey liver cytochrome P450 2C19 is involved in R- and S-warfarin 7-hydroxylation.

    Science.gov (United States)

    Hosoi, Yoshio; Uno, Yasuhiro; Murayama, Norie; Fujino, Hideki; Shukuya, Mitsunori; Iwasaki, Kazuhide; Shimizu, Makiko; Utoh, Masahiro; Yamazaki, Hiroshi

    2012-12-15

    Cynomolgus monkeys are widely used as primate models in preclinical studies. However, some differences are occasionally seen between monkeys and humans in the activities of cytochrome P450 enzymes. R- and S-warfarin are model substrates for stereoselective oxidation in humans. In this current research, the activities of monkey liver microsomes and 14 recombinantly expressed monkey cytochrome P450 enzymes were analyzed with respect to R- and S-warfarin 6- and 7-hydroxylation. Monkey liver microsomes efficiently mediated both R- and S-warfarin 7-hydroxylation, in contrast to human liver microsomes, which preferentially catalyzed S-warfarin 7-hydroxylation. R-Warfarin 7-hydroxylation activities in monkey liver microsomes were not inhibited by α-naphthoflavone or ketoconazole, and were roughly correlated with P450 2C19 levels and flurbiprofen 4-hydroxylation activities in microsomes from 20 monkey livers. In contrast, S-warfarin 7-hydroxylation activities were not correlated with the four marker drug oxidation activities used. Among the 14 recombinantly expressed monkey P450 enzymes tested, P450 2C19 had the highest activities for R- and S-warfarin 7-hydroxylations. Monkey P450 3A4 and 3A5 slowly mediated R- and S-warfarin 6-hydroxylations. Kinetic analysis revealed that monkey P450 2C19 had high V(max) and low K(m) values for R-warfarin 7-hydroxylation, comparable to those for monkey liver microsomes. Monkey P450 2C19 also mediated S-warfarin 7-hydroxylation with V(max) and V(max)/K(m) values comparable to those for recombinant human P450 2C9. R-warfarin could dock favorably into monkey P450 2C19 modeled. These results collectively suggest high activities for monkey liver P450 2C19 toward R- and S-warfarin 6- and 7-hydroxylation in contrast to the saturation kinetics of human P450 2C9-mediated S-warfarin 7-hydroxylation. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Carbamazepine-hypersensitivity: assessment of clinical and in vitro chemical cross-reactivity with phenytoin and oxcarbazepine.

    Science.gov (United States)

    Pirmohamed, M; Graham, A; Roberts, P; Smith, D; Chadwick, D; Breckenridge, A M; Park, B K

    1991-01-01

    1. Seven patients clinically diagnosed as being hypersensitive to carbamazepine and one patient hypersensitive to both carbamazepine and oxcarbazepine have been identified. They have been compared with a control group (hereafter referred to as 'control subjects') comprising five patients on chronic carbamazepine therapy without adverse effects and 12 healthy volunteers who have never been exposed to anticonvulsants. 2. An in vitro cytotoxicity assay employing mononuclear leucocytes as target cells has been used first, to determine the ability of 10 different human livers to bioactivate carbamazepine to a cytotoxic metabolite, and secondly, to compare the cell defences of carbamazepine-hypersensitive patients and control subjects to oxidative drug metabolites generated by a murine microsomal system, using a blinded protocol. 3. With human liver microsomes, the metabolism-dependent cytotoxicity of carbamazepine increased with increasing microsomal protein concentration. At a protein concentration of 2 mg per incubation, the cytotoxicity of carbamazepine with human liver microsomes (n = 10 livers) increased from 7.2 +/- 0.8% (baseline) to 16.4 +/- 2.1% (with NADPH; P = 0.002). 4. In the presence of phenobarbitone-induced mouse microsomes and NADPH, the mean increase in cytotoxicity above the baseline with carbamazepine was significantly greater (P less than 0.001) for the cells from the carbamazepine-hypersensitive patients (7.9 +/- 0.8%) than from control subjects (2.6 +/- 0.3%). 5. In the presence of phenobarbitone-induced mouse microsomes and NADPH, there was no significant difference in cytotoxicity between the cells from carbamazepine hypersensitive patients and from control subjects in the presence of either phenytoin or oxcarbazepine.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1768568

  18. Frequency and significance of antibodies to liver/kidney microsome type 1 in adults with chronic active hepatitis.

    Science.gov (United States)

    Czaja, A J; Manns, M P; Homburger, H A

    1992-10-01

    To assess the frequency of antibodies to liver/kidney microsome type 1 (anti-LKM1) in patients with chronic active hepatitis, 131 such patients were tested by an indirect immunofluorescence assay. Of 62 patients with type 1 autoimmune hepatitis, none were seropositive. In contrast, 3 of 11 patients with autoimmune hepatitis and antimitochondrial antibodies (27%) were seropositive for anti-LKM1. Each had responded to corticosteroid therapy, and retesting of sera confirmed that each had been misclassified as antimitochondrial antibody positive. None of the patients with chronic active hepatitis B (14 patients) or C (24 patients) had anti-LKM1. Similarly, none of the 20 patients with cryptogenic disease had these antibodies. It is concluded that anti-LKM1 is specific for type 2 autoimmune hepatitis and is infrequent in adult patients seen at a referral center in the United States for chronic active hepatitis. Anti-LKM1 reactivity may be misinterpreted as antimitochondrial antibody reactivity by indirect immunofluorescence. Chronic hepatitis B and C virus infections are not important stimuli for the production of anti-LKM1, and testing for anti-LKM 1 is unlikely to clarify the nature of cryptogenic disease.

  19. Differences in both glycosylation and binding properties between rat and mouse liver prolactin receptors.

    Science.gov (United States)

    Lascols, O; Cherqui, G; Munier, A; Picard, J; Capeau, J

    1994-05-01

    To investigate whether glycanic chains of prolactin receptors (PRL-R) play a role in hormone binding activity, comparison was made of rat and mouse liver solubilized receptors with respect to both their affinity for the hormone and their glycosylation properties. As compared with rat receptors, mouse receptors exhibited a 2-fold higher affinity for human growth hormone (hGH), the hormone being bound by both tissues with a lactogenic specificity. Along with this increased affinity, mouse receptors had a 2 lower M(r) relative to rat receptors (62 kDa versus 64 kDa as measured on hGH cross-linked receptors). These differences could be ascribed to different glycosylation properties of the receptors from the two species, as supported by the followings. 1) After treatment with endoglycosidase F (endo F), rat and mouse PRL-R no longer exhibited any difference in their M(r) (54 kDa for both cross-linked receptors). 2) Neuraminidase treatment increased by 37% the binding of hGH to mouse receptors, but was ineffective on the hormone-binding to rat receptors. Conversely, wheat germ agglutinin (WGA), another sialic acid specific probe, decreased hGH binding to rat receptors by 25%, but had no effect on this process for mouse ones. 3) Marked differences were observed in the recoveries of rat and mouse hormone-receptor (HR) complexes from ricin-1- (RCA1-), concanavalin A- (ConA-) and WGA-immobilized lectins. These differences were reduced (RCA1 and ConA) or abolished (WGA) after rat and mouse receptor desialylation by neuraminidase, a treatment which decreased the M(r) of both receptors by 2 kDa. Taken together, these results strongly suggest that the PRL-R from rat and mouse liver contain biantennary N-linked oligosaccharidic chains with distinct type of sialylation, which may account for their differential hormone-binding affinities.

  20. Inhibition of the phospholipid transfer within the organelles of cells in the irradiated rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Kaznacheev, Yu S; Kolomiytseva, I K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki

    1975-01-01

    Phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) exchange between different subcellular fractions of liver has been studied in normal rats and 1 hr after gamma-irradiation of rats at a dose of 1200 R. The rate of PC transfer in microsome-mitochondrion and microsome-nucleus systems is 1.5 to 2 times higher than that of PE. Early after irradiation the rates of PE and PC transfer decrease in both microsome-mitochondrion and microsome-nucleus systems.

  1. Hepatitis B spliced protein (HBSP) promotes the carcinogenic effects of benzo [alpha] pyrene by interacting with microsomal epoxide hydrolase and enhancing its hydrolysis activity

    International Nuclear Information System (INIS)

    Chen, Jin-Yan; Chen, Wan-Nan; Jiao, Bo-Yan; Lin, Wan-Song; Wu, Yun-Li; Liu, Ling-Ling; Lin, Xu

    2014-01-01

    The risk of hepatocellular carcinoma (HCC) increases in chronic hepatitis B surface antigen (HBsAg) carriers who often have concomitant increase in the levels of benzo[alpha]pyrene-7,8-diol-9,10-epoxide(±) (BPDE)-DNA adduct in liver tissues, suggesting a possible co-carcinogenesis of Hepatitis B virus (HBV) and benzo[alpha]pyrene in HCC; however the exact mechanisms involved are unclear. The interaction between hepatitis B spliced protein (HBSP) and microsomal epoxide hydrolase (mEH) was confirmed using GST pull-down, co-immunoprecipitation and mammalian two-hybrid assay; the effects of HBSP on mEH-mediated B[alpha]P metabolism was examined by high performance liquid chromatography (HPLC); and the influences of HBSP on B[alpha]P carcinogenicity were evaluated by bromodeoxyuridine cell proliferation, anchorage-independent growth and tumor xenograft. HBSP could interact with mEH in vitro and in vivo, and this interaction was mediated by the N terminal 47 amino acid residues of HBSP. HBSP could greatly enhance the hydrolysis activity of mEH in cell-free mouse liver microsomes, thus accelerating the metabolism of benzo[alpha]pyrene to produce more ultimate carcinnogen, BPDE, and this effect of HBSP requires the intact HBSP molecule. Expression of HBSP significantly increased the formation of BPDE-DNA adduct in benzo[alpha]pyrene-treated Huh-7 hepatoma cells, and this enhancement was blocked by knockdown of mEH. HBSP could enhance the cell proliferation, accelerate the G1/S transition, and promote cell transformation and tumorigenesis of B[alpha]P-treated Huh-7 hepatoma cells. Our results demonstrated that HBSP could promote carcinogenic effects of B[alpha]P by interacting with mEH and enhancing its hydrolysis activity

  2. Stereoselective in vitro metabolism of rhynchophylline and isorhynchophylline epimers of Uncaria rhynchophylla in rat liver microsomes.

    Science.gov (United States)

    Wang, Xin; Qiao, Zhou; Liu, Jia; Zheng, Mei; Liu, Wenyuan; Wu, Chunyong

    2017-11-10

    1. The objective was to investigate the underlying mechanism of the stereoselectivity in the metabolism of rhynchophylline (RIN) and isorhynchophylline (IRN) epimers in rat liver microsomes (RLM). 2. After incubation, eight metabolites of RIN (M1-5) and IRN (M6-8) reacted at A- and C-ring were identified using LC-Q-TOF/MS. Metabolic pathways included oxidation, hydroxylation, N-oxidation and dehydrogenation. In addition, hydroxylation at A-ring was the major metabolic pathway for RIN whereas the oxidation at C-ring was the major one for IRN. 3. Enzyme kinetics showed that the intrinsic clearance (CL int ) for IRN elimination was 1.9-fold higher than RIN and the degradation half-life (T 1/2 ) of RIN was 4.7-fold higher than that of IRN, indicating IRN was more favorable to be metabolized than RIN in RLM. 4. Data from chemical inhibition study demonstrated CYP3A was the predominant isoform involved in the metabolic elimination of both epimers, as well as the formation of M1-8. 5. In conclusion, data revealed that due to the spatial configurations at C-7 position, RIN and IRN epimers possessed different hepatic metabolic pathways and elimination rates which were mainly mediated by CYP3A.

  3. CYP2B6, CYP2D6, and CYP3A4 catalyze the primary oxidative metabolism of perhexiline enantiomers by human liver microsomes.

    Science.gov (United States)

    Davies, Benjamin J; Coller, Janet K; Somogyi, Andrew A; Milne, Robert W; Sallustio, Benedetta C

    2007-01-01

    The cytochrome P450 (P450)-mediated 4-monohydroxylations of the individual enantiomers of the racemic antianginal agent perhexiline (PHX) were investigated in human liver microsomes (HLMs) to identify stereoselective differences in metabolism and to determine the contribution of the polymorphic enzyme CYP2D6 and other P450s to the intrinsic clearance of each enantiomer. The cis-, trans1-, and trans2-4-monohydroxylation rates of (+)- and (-)-PHX by human liver microsomes from three extensive metabolizers (EMs), two intermediate metabolizers (IMs), and two poor metabolizers (PMs) of CYP2D6 were measured with a high-performance liquid chromatography assay. P450 isoform-specific inhibitors, monoclonal antibodies directed against P450 isoforms, and recombinantly expressed human P450 enzymes were used to define the P450 isoform profile of PHX 4-monohydroxylations. The total in vitro intrinsic clearance values (mean +/- S.D.) of (+)- and (-)-PHX were 1376 +/- 330 and 2475 +/- 321, 230 +/- 225 and 482 +/- 437, and 63.4 +/- 1.6 and 54.6 +/- 1.2 microl/min/mg for the EM, IM, and PM HLMs, respectively. CYP2D6 catalyzes the formation of cis-OH-(+)-PHX and trans1-OH-(+)-PHX from (+)-PHX and cis-OH-(-)-PHX from (-)-PHX with high affinity. CYP2B6 and CYP3A4 each catalyze the trans1- and trans2-4-monohydroxylation of both (+)- and (-)-PHX with low affinity. Both enantiomers of PHX are subject to significant polymorphic metabolism by CYP2D6, although this enzyme exhibits distinct stereoselectivity with respect to the conformation of metabolites and the rate at which they are formed. CYP2B6 and CYP3A4 are minor contributors to the intrinsic P450-mediated hepatic clearance of both enantiomers of PHX, except in CYP2D6 PMs.

  4. RATE AND CAPACITY OF HEPATIC MICROSOMAL RING HYDROXYLATION OF PHENOL TO HYDROQUINONE AND CATECHOL IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

    Science.gov (United States)

    Rainbow trout liver microsomes were used to study the rate of ring-hydroxylation of phenol (PH) by directly measuring the production of hydroquinone (HQ), the primary metabolite, and catechol (CAT), a secondary metabolite. An HPLC method with integrated ultroviolet (UV) and elect...

  5. Acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in hepatic microsomes from induced mice.

    Science.gov (United States)

    Lewandowski, M; Chui, Y C; Levi, P; Hodgson, E

    1991-02-01

    A simple and sensitive method for the separation of 14C-labelled acetanilide, 4-hydroxyacetanilide, 3-hydroxyacetanilide and 2-hydroxyacetanilide was developed using thin-layer chromatography. This separation is the basis for the assay of acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in liver microsomes from DBA2/N male mice that had been treated with phenobarbital, 3-methylcholanthrene, isosafrole or n-butylbenzodioxole. Microsomes were incubated with [14C]acetanilide and extracted with benzene and ethyl acetate. The extract was applied to silica gel plates and developed with a hexane/isopropanol/ammonium hydroxide/water solvent system. The radiolabelled phenolic metabolites and the parent compound were detected using a Berthold Automatic TLC Linear Analyzer. Although the 4-hydroxylated metabolite was the primary product detected, this method can be used to detect other phenolic metabolites.

  6. Targeted induction of interferon-λ in humanized chimeric mouse liver abrogates hepatotropic virus infection.

    Directory of Open Access Journals (Sweden)

    Shin-ichiro Nakagawa

    Full Text Available BACKGROUND & AIMS: The interferon (IFN system plays a critical role in innate antiviral response. We presume that targeted induction of IFN in human liver shows robust antiviral effects on hepatitis C virus (HCV and hepatitis B virus (HBV. METHODS: This study used chimeric mice harboring humanized livers and infected with HCV or HBV. This mouse model permitted simultaneous analysis of immune responses by human and mouse hepatocytes in the same liver and exploration of the mechanism of antiviral effect against these viruses. Targeted expression of IFN was induced by treating the animals with a complex comprising a hepatotropic cationic liposome and a synthetic double-stranded RNA analog, pIC (LIC-pIC. Viral replication, IFN gene expression, IFN protein production, and IFN antiviral activity were analyzed (for type I, II and III IFNs in the livers and sera of these humanized chimeric mice. RESULTS: Following treatment with LIC-pIC, the humanized livers of chimeric mice exhibited increased expression (at the mRNA and protein level of human IFN-λs, resulting in strong antiviral effect on HBV and HCV. Similar increases were not seen for human IFN-α or IFN-β in these animals. Strong induction of IFN-λs by LIC-pIC occurred only in human hepatocytes, and not in mouse hepatocytes nor in human cell lines derived from other (non-hepatic tissues. LIC-pIC-induced IFN-λ production was mediated by the immune sensor adaptor molecules mitochondrial antiviral signaling protein (MAVS and Toll/IL-1R domain-containing adaptor molecule-1 (TICAM-1, suggesting dual recognition of LIC-pIC by both sensor adaptor pathways. CONCLUSIONS: These findings demonstrate that the expression and function of various IFNs differ depending on the animal species and tissues under investigation. Chimeric mice harboring humanized livers demonstrate that IFN-λs play an important role in the defense against human hepatic virus infection.

  7. Isolation and purification of rat liver morphine UDP-glucuronosyltransferase

    International Nuclear Information System (INIS)

    Puig, J.F.; Tephly, T.R.

    1986-01-01

    The enhancement of rat liver microsomal morphine (M) and 4-hydroxybiphenyl (4-HBP) UDP-glucuronyltransferase (UDPGT) activities by phenobarbital treatment has been proposed to represent increased activity of a single enzyme form, GT-2. They have separated M and 4-HBP UDPGT activities from Emulgen 911-solubilized microsomes obtained from livers of phenobarbital-treated Wistar rats. A sensitive assay procedure was developed to quantify M-UDPGT and 4-HBP-UDPGT activities using 14 C-UDP-glucuronic acid (UDPGA) and reversed phase C-18 minicolumns whereby the radioactive glucuronides were differentially eluted from labeled UDPGA. Trisacryl DEAE, and chromatofocusing procedures were employed to separate M-UDPGT and 4-HBP-UDPGT in the presence of exogenous phosphatidylcholine (PC). The PC is necessary to stabilize UDPGT activities. M-UDPGT was isolated to apparent homogeneity and displayed a monomeric molecular weight of 56,000 daltons on SDS-PAGE. It reacted with M but not with 4-HBP, bilirubin, p-nitrophenol, testosterone, androsterone, estrone, 4-aminobiphenyl or α-naphthylamine. 4-HBP-UDPGT did not react with M. Therefore, M and 4-HBP glucuronidations are catalyzed by separate enzymes in rat liver microsomes

  8. 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.

  9. 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

  10. Chromatographic separation of piracetam and its metabolite in a mixture of microsomal preparations, followed by an MS/MS analysis.

    Science.gov (United States)

    Sahu, Kapendra; Siddiqui, Anees A; Shaharyar, Mohammad; Ahmad, Niyaz; Anwar, Mohammad; Ahmad, Farhan J

    2013-07-01

    A rapid bioanalytical method was evaluated for the simultaneous determination of piracetam and its metabolite (M1) in human microsomal preparations by fast ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). In addition, a validated method of M1 in rat plasma was developed and successfully applied on pharmacokinetic studies. The present study was carried out to determine the metabolic pathways of piracetam for phase I metabolism and used cytochrome P450 isoforms responsible for the piracetam metabolism in human liver microsomes (HLMs). While additional potential metabolites of piracetam were suggested by computer-modeling. The resulting 2-(2-oxopyrrolidin-1-yl) acetic acid was the sole metabolite detected after the microsomal treatment. The amide hydrolysis mainly underwent to form a metabolite i.e., 2-(2-oxopyrrolidin-1-yl) acetic acid (M1). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  11. In vitro enantioselective human liver microsomal metabolism and prediction of in vivo pharmacokinetic parameters of tetrabenazine by DLLME-CE.

    Science.gov (United States)

    Bocato, Mariana Zuccherato; de Lima Moreira, Fernanda; de Albuquerque, Nayara Cristina Perez; de Gaitani, Cristiane Masetto; de Oliveira, Anderson Rodrigo Moraes

    2016-09-05

    A new capillary electrophoresis method for the enantioselective analysis of cis- and trans- dihydrotetrabenazine (diHTBZ) after in vitro metabolism by human liver microsomes (HLMs) was developed. The chiral electrophoretic separations were performed by using tris-phosphate buffer (pH 2.5) containing 1% (w/v) carboxymethyl-β-CD as background electrolyte with an applied voltage of +15kV and capillary temperature kept at 15°C. Dispersive liquid-liquid microextraction was employed to extract the analytes from HLMs. Dichloromethane was used as extraction solvent (75μL) and acetone as disperser solvent (150μL). The method was validated according to official guidelines and showed to be linear over the concentration range of 0.29-19.57μmolL(-1) (r=0.9955) for each metabolite enantiomer. Within- and between-day precision and accuracy evaluated by relative standard deviation and relative error were lower than 15% for all enantiomers. The stability assay showed that the analytes kept stable under handling, storage and in metabolism conditions. After method validation, an enantioselective in vitro metabolism and in vivo pharmacokinetic prediction was carried out. This study showed a stereoselective metabolism and the observed kinetic profile indicated a substrate inhibition behavior. DiHTBZ enantiomers were catalyzed mainly by CYP2C19 and the predicted clearance suggests that liver metabolism is the main route for TBZ elimination which supports the literature data. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Interaction of rocuronium with human liver cytochromes P450.

    Science.gov (United States)

    Anzenbacherova, Eva; Spicakova, Alena; Jourova, Lenka; Ulrichova, Jitka; Adamus, Milan; Bachleda, Petr; Anzenbacher, Pavel

    2015-02-01

    Rocuronium is a neuromuscular blocking agent acting as a competitive antagonist of acetylcholine. Results of an inhibition of eight individual liver microsomal cytochromes P450 (CYP) are presented. As the patients are routinely premedicated with diazepam, possible interaction of diazepam with rocuronium has been also studied. Results indicated that rocuronium interacts with human liver microsomal CYPs by binding to the substrate site. Next, concentration dependent inhibition of liver microsomal CYP3A4 down to 42% (at rocuronium concentration 189 μM) was found. This effect has been confirmed with two CYP3A4 substrates, testosterone (formation of 6β-hydroxytestosterone) and diazepam (temazepam formation). CYP2C9 and CYP2C19 activities were inhibited down to 75-80% (at the same rocuronium concentration). Activities of other microsomal CYPs have not been inhibited by rocuronium. To prove the possibility of rocuronium interaction with other drugs (diazepam), the effect of rocuronium on formation of main diazepam metabolites, temazepam (by CYP3A4) and desmethyldiazepam, (also known as nordiazepam; formed by CYP2C19) in primary culture of human hepatocytes has been examined. Rocuronium has caused inhibition of both reactions by 20 and 15%, respectively. The results open a possibility that interactions of rocuronium with drugs metabolized by CYP3A4 (and possibly also CYP2C19) may be observed. Copyright © 2014 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

  13. Comparative Analysis of the Relationship between Trichloroethylene Metabolism and Tissue-Specific Toxicity among Inbred Mouse Strains: Liver Effects

    Science.gov (United States)

    Yoo, Hong Sik; Bradford, Blair U.; Kosyk, Oksana; Shymonyak, Svitlana; Uehara, Takeki; Collins, Leonard B.; Bodnar, Wanda M.; Ball, Louise M.; Gold, Avram; Rusyn, Ivan

    2014-01-01

    Trichloroethylene (TCE) is a widely used organic solvent. Although TCE is classified as carcinogenic to humans, substantial gaps remain in our understanding of inter-individual variability in TCE metabolism and toxicity, especially in the liver. We tested a hypothesis that amounts of oxidative metabolites of TCE in mouse liver are associated with liver-specific toxicity. Oral dosing with TCE was conducted in sub-acute (600 mg/kg/d; 5 days; 7 inbred mouse strains) and sub-chronic (100 or 400 mg/kg/d; 1, 2, or 4 weeks; 2 inbred mouse strains) designs. We evaluated the quantitative relationship between strain-, dose-, and time-dependent formation of TCE metabolites from cytochrome P450-mediated oxidation [trichloroacetic acid (TCA), dichloroacetic acid (DCA), and trichloroethanol] and glutathione conjugation [S-(1,2-dichlorovinyl)-L-cysteine and S-(1,2-dichlorovinyl)glutathione] in serum and liver, and various liver toxicity phenotypes. In sub-acute study, inter-strain variability in TCE metabolite amounts was observed in serum and liver. No induction of Cyp2e1 protein levels in liver was detected. Serum and liver levels of TCA and DCA were correlated with increased transcription of peroxisome proliferator-marker genes Cyp4a10 and Acox1, but not with degree of induction in hepatocellular proliferation. In sub-chronic study, serum and liver levels of oxidative metabolites gradually decreased over time despite continuous dosing. Liver protein levels of Cyp2e1, Adh and Aldh2 were unaffected by treatment with TCE. While the magnitude of induction of peroxisome proliferator-marker genes also declined, hepatocellular proliferation increased. This study offers a unique opportunity to provide a scientific data-driven rationale for some of the major assumptions in human health assessment of TCE. PMID:25424544

  14. Activation of the microsomal glutathione-S-transferase and reduction of the glutathione dependent protection against lipid peroxidation by acrolein

    NARCIS (Netherlands)

    Haenen, G R; Vermeulen, N P; Tai Tin Tsoi, J N; Ragetli, H M; Timmerman, H; Blast, A

    1988-01-01

    Allyl alcohol is hepatotoxic. It is generally believed that acrolein, generated out of allyl alcohol by cytosolic alcohol dehydrogenase, is responsible for this toxicity. The effect of acrolein in vitro and in vivo on the glutathione (GSH) dependent protection of liver microsomes against lipid

  15. Perfluorodecanoic acid enhances the formation of oleic acid in rat liver.

    Science.gov (United States)

    Yamamoto, A; Kawashima, Y

    1997-01-01

    The feeding of perfluorodecanoic acid (PFDA) to male rats at a dietary concentration of 0.005% (w/w) for 7 days resulted in a marked increase in the activity of microsomal stearoyl-CoA desaturation in the liver. This increase in the overall desaturation activity was due to the induction of terminal desaturase among the components comprising the desaturation system. In contrast, PFDA inhibited desaturation in vitro, seemingly due to interference with electron transport through the desaturation system. Accordingly, PFDA can be an inducer and also an inhibitor of delta9-desaturation. PFDA feeding enhanced the conversion of radioactive stearic acid into oleic acid in the liver in vivo, indicating that the induction of delta9-desaturase by PFDA functions in vivo. PFDA feeding increased the mass of octadecenoic acid (C18:1) in the liver and the proportion of C18:1 in microsomal lipid. A highly significant linear correlation existed between the microsomal desaturase activity and the proportion of C18:1 in microsomal lipid when compared using rats in five different physiological states: control, PFDA-fed, p-chlorophenoxyisobutyric acid (clofibric acid)-fed, starved and starved/refed. These results suggest that the increase in the hepatic level of C18:1 caused by feeding of PFDA to rats can be explained by the common concept of regulation, i.e. the hepatic level of C18:1 is under the control of delta9-desaturase. The dietary administration of PFDA also increased the content of cytochrome P-450 and the activity of 7-ethoxycoumarin O-de-ethylase in the liver. PMID:9230124

  16. Hepatocyte Hypoxia Inducible Factor-1 Mediates the Development of Liver Fibrosis in a Mouse Model of Nonalcoholic Fatty Liver Disease.

    Directory of Open Access Journals (Sweden)

    Omar A Mesarwi

    Full Text Available Obstructive sleep apnea (OSA is associated with the progression of non-alcoholic fatty liver disease (NAFLD to steatohepatitis and fibrosis. This progression correlates with the severity of OSA-associated hypoxia. In mice with diet induced obesity, hepatic steatosis leads to liver tissue hypoxia, which worsens with exposure to intermittent hypoxia. Emerging data has implicated hepatocyte cell signaling as an important factor in hepatic fibrogenesis. We hypothesized that hepatocyte specific knockout of the oxygen sensing α subunit of hypoxia inducible factor-1 (HIF-1, a master regulator of the global response to hypoxia, may be protective against the development of liver fibrosis.Wild-type mice and mice with hepatocyte-specific HIF-1α knockout (Hif1a-/-hep were fed a high trans-fat diet for six months, as a model of NAFLD. Hepatic fibrosis was evaluated by Sirius red stain and hydroxyproline assay. Liver enzymes, fasting insulin, and hepatic triglyceride content were also assessed. Hepatocytes were isolated from Hif1a-/-hep mice and wild-type controls and were exposed to sustained hypoxia (1% O2 or normoxia (16% O2 for 24 hours. The culture media was used to reconstitute type I collagen and the resulting matrices were examined for collagen cross-linking.Wild-type mice on a high trans-fat diet had 80% more hepatic collagen than Hif1a-/-hep mice (2.21 μg collagen/mg liver tissue, versus 1.23 μg collagen/mg liver tissue, p = 0.03, which was confirmed by Sirius red staining. Body weight, liver weight, mean hepatic triglyceride content, and fasting insulin were similar between groups. Culture media from wild-type mouse hepatocytes exposed to hypoxia allowed for avid collagen cross-linking, but very little cross-linking was seen when hepatocytes were exposed to normoxia, or when hepatocytes from Hif1a-/-hep mice were used in hypoxia or normoxia.Hepatocyte HIF-1 mediates an increase in liver fibrosis in a mouse model of NAFLD, perhaps due to liver

  17. In vitro inactivation of hepatic microsomal phospholipase A2 by the marine natural product manoalide

    International Nuclear Information System (INIS)

    Master, M.M.; Jacobs, R.S.

    1986-01-01

    The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A 2 (PLA 2 ) activity was investigated. Microsomal PLA 2 , a membrane bound, Ca ++ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA 2 activity was assayed by preincubating MLD or analogs (2.5-100μM) with microsomes for 60 min. at 37 0 C, combining this mixture with 14 C-phosphatidylcholine and CaCl 2 , and incubating at 37 0 C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted 14 C-arachidonic acid product. MLD inhibited PLA 2 in a dose-dependent manner, with an IC 50 = 94μM. Lineweaver-Burk analysis suggests that MLD inhibits PLA 2 noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC 50 = 33μM). Another analog facilitated PLA 2 activity (15%) at 25μM, followed by inactivation at higher doses (IC 50 > 100 μM). Facilitation of PLA 2 activity was seen with concentrations as low as 2.5μM of a third analog, and significant inactivation of PLA 2 was evident. These results indicate that MLD is not as potent against microsomal PLA 2 as has been shown with purified bee venom and cobra venom PLA 2 's

  18. Early radiation impairment of the cholesterol metabolism in organelles of rat liver cells

    Energy Technology Data Exchange (ETDEWEB)

    Kaznacherev, Yu S; Kolomiitseva, I K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki

    1975-05-01

    The incorporation of 1-C/sup 14/-acetate into cholesterol of the nuclear, mitochondrial, microsomal and 105000 g-supernatant fractions isolated from the rat liver in norm and 60 min after the exposure to 1200 r has been investigated. An increase has been observed in the label uptake into liver cholesterol of irradiated rats. Intracellular distribution of the newly synthesized (labelled) cholesterol is substantially changed after irradiation: maximum label incorporation into the cholesterol is observed in the 105000 g-supernatant fraction, whereas, normally, the cholesterol of microsomal fraction has the highest specific activity.

  19. Protein phosphatases 2A as well as reactive oxygen species involved in tributyltin-induced apoptosis in mouse livers.

    Science.gov (United States)

    Zhang, Yali; Chen, Yonggang; Sun, Lijun; Liang, Jing; Guo, Zonglou; Xu, Lihong

    2014-02-01

    Tributyltin (TBT), a highly toxic environmental contaminant, has been shown to induce caspase-3-dependent apoptosis in human amniotic cells through protein phosphatase 2A (PP2A) inhibition and consequent JNK activation. This in vivo study was undertaken to further verify the results derived from our previous in vitro study. Mice were orally dosed with 0, 10, 20, and 60 mg/kg of body weight TBT, and levels of PP2A, reactive oxygen species (ROS), mitogen-activated protein kinase (MAPK), Bax/Bcl-2, and caspase-3 were detected in the mouse livers. Apoptosis was also evaluated using the TUNEL assay. The results showed that PP2A activity was inhibited, ROS levels were elevated, and MAPKs including ERK, JNK, and p38 were activated in mouse livers treated with the highest dose of TBT. Additionally, the ratio of Bax/Bcl-2 was increased, caspase-3 was activated, and apoptosis in mouse livers could be detected in the highest dose group. Therefore, a possible signaling pathway in TBT-induced apoptosis in mouse livers involves PP2A inhibition and ROS elevation serving a pivotal function as upstream activators of MAPKs; activation of MAPKs in turn leads to an increase in the Bax/Bcl-2 ratio, ultimately leading to the activation of caspase-3. The results give a comprehensive and novel description of the mechanism of TBT-induced toxicity. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

  20. Regulation of retinoid X receptor gamma expression by fed state in mouse liver

    International Nuclear Information System (INIS)

    Park, Sangkyu; Lee, Yoo Jeong; Ko, Eun Hee; Kim, Jae-woo

    2015-01-01

    Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα

  1. Regulation of retinoid X receptor gamma expression by fed state in mouse liver

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sangkyu, E-mail: 49park@cku.ac.kr [Department of Biochemistry, College of Medicine, Catholic Kwandong University, Gangneung 210-701 (Korea, Republic of); Lee, Yoo Jeong [Division of Metabolic Disease, Center for Biomedical Sciences, National Institute of Health Korea, Osong 361-709 (Korea, Republic of); Ko, Eun Hee [Department of Biochemistry and Molecular Biology, Integrated Genomic Research Center for Metabolic Regulation, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jae-woo [Department of Biochemistry and Molecular Biology, Integrated Genomic Research Center for Metabolic Regulation, Institute of Genetic Science, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul 120-752 (Korea, Republic of)

    2015-02-27

    Glucose metabolism is balanced by glycolysis and gluconeogenesis with precise control in the liver. The expression of genes related to glucose metabolism is regulated primarily by glucose and insulin at transcriptional level. Nuclear receptors play important roles in regulating the gene expression of glucose metabolism at transcriptional level. Some of these nuclear receptors form heterodimers with RXRs to bind to their specific regulatory elements on the target promoters. To date, three isotypes of RXRs have been identified; RXRα, RXRβ and RXRγ. However, their involvement in the interactions with other nuclear receptors in the liver remains unclear. In this study, we found RXRγ is rapidly induced after feeding in the mouse liver, indicating a potential role of RXRγ in controlling glucose or lipid metabolism in the fasting–feeding cycle. In addition, RXRγ expression was upregulated by glucose in primary hepatocytes. This implies that glucose metabolism governed by RXRγ in conjunction with other nuclear receptors. The luciferase reporter assay showed that RXRγ as well as RXRα increased SREBP-1c promoter activity in hepatocytes. These results suggest that RXRγ may play an important role in tight control of glucose metabolism in the fasting–feeding cycle. - Highlights: • Refeeding increases the RXRγ expression level in mouse liver. • RXRγ expression is induced by high glucose condition in primary hepatocytes. • RXRγ and LXRα have synergistic effect on SREBP-1c promoter activity. • RXRγ binds to LXRE(-299/-280) located within SREBP-1c promoter region and interacts with LXRα.

  2. Characterization of genetically engineered mouse hepatoma cells with inducible liver functions by overexpression of liver-enriched transcription factors.

    Science.gov (United States)

    Yamamoto, Hideaki; Tonello, Jane Marie; Sambuichi, Takanori; Kawabe, Yoshinori; Ito, Akira; Kamihira, Masamichi

    2018-01-01

    New cell sources for the research and therapy of organ failure could significantly alleviate the shortage of donor livers that are available to patients who suffer from liver disease. Liver carcinoma derived cells, or hepatoma cells, are the ideal cells for developing bioartificial liver systems. Such cancerous liver cells are easy to prepare in large quantities and can be maintained over long periods under standard culture conditions, unlike primary hepatocytes. However, hepatoma cells possess only a fraction of the functions of primary hepatocytes. In a previous study, by transducing cells with liver-enriched transcription factors that could be inducibly overexpressed-hepatocyte nuclear factor (HNF)1α, HNF1β, HNF3β [FOXA2], HNF4α, HNF6, CCAAT/enhancer binding protein (C/EBP)α, C/EBPβ and C/EBPγ-we created mouse hepatoma cells with high liver-specific gene expression called the Hepa/8F5 cell line. In the present study, we performed functional and genetic analyses to characterize the Hepa/8F5 cell line. Further, in three-dimensional cultures, the function of these cells improved significantly compared to parental cells. Ultimately, these cells might become a new resource that can be used in basic and applied hepatic research. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Maternal western diet primes non-alcoholic fatty liver disease in adult mouse offspring

    NARCIS (Netherlands)

    Pruis, M. G. M.; Lendvai, A.; Bloks, V. W.; Zwier, M. V.; Baller, J. F. W.; de Bruin, A.; Groen, A. K.; Plosch, T.

    AimMetabolic programming via components of the maternal diet during gestation may play a role in the development of different aspects of the metabolic syndrome. Using a mouse model, we aimed to characterize the role of maternal western-type diet in the development of non-alcoholic fatty liver

  4. Case Study: Polycystic Livers in a Transgenic Mouse Line

    Energy Technology Data Exchange (ETDEWEB)

    Lovaglio, Jamie A.; Artwohl, James E.; Ward, Christopher J.; Diekwisch, Thomas G. H.; Ito, Yoshihiro; Fortman, Jeffrey D.

    2014-04-01

    Three mice (2 male, 1 female; age, 5 to 16 mo) from a mouse line transgenic for keratin 14 (K14)-driven LacZ expression and on an outbred Crl:CD1(ICR) background, were identified as having distended abdomens and livers that were diffusely enlarged by numerous cysts (diameter, 0.1 to 2.0 cm). Histopathology revealed hepatic cysts lined by biliary type epithelium and mild chronic inflammation, and confirmed the absence of parasites. Among 21 related mice, 5 additional affected mice were identified via laparotomy. Breeding of these 5 mice (after 5 mo of age) did not result in any offspring; the K14 mice with olycystic livers failed to reproduce. Affected male mice had degenerative testicular lesions, and their sperm was immotile. Nonpolycystic K14 control male mice bred well, had no testicular lesions, and had appropriate sperm motility. Genetic analysis did not identify an association of this phenotype with the transgene or insertion site.

  5. Heme synthesis in normal mouse liver and mouse liver tumors

    International Nuclear Information System (INIS)

    Stout, D.L.; Becker, F.F.

    1990-01-01

    Hepatic cancers from mice and rats demonstrate decreased levels of delta-aminolevulinic acid synthase, the rate-limiting enzyme in the heme synthetic pathway, and increased heme oxygenase, the heme-catabolizing enzyme. These findings suggest that diminution of P-450, b5, and catalase in these lesions may result from a heme supply that is limited by decreased heme synthesis and increased heme catabolism. Heme synthesis was measured in mouse liver tumors (MLT) and adjacent tumor-free lobes (BKG) by administering the radiolabeled heme precursors 55 FeCl3 and [2- 14 C]glycine and subsequently extracting the heme for determination of specific activity. Despite reduced delta-aminolevulinic acid synthase activity in MLT, both tissues incorporated [2-14C]glycine into heme at similar rates. At early time points, heme extracted from MLT contained less 55Fe than that from BKG. This was attributed to the findings that MLT took up 55Fe at a slower rate than BKG and had larger iron stores than BKG. The amount of heme per milligram of protein was also similar in both tissues. These findings militate against the hypothesis that diminished hemoprotein levels in MLT result from limited availability of heme. It is probable, therefore, that decreased hemoprotein levels in hepatic tumors are linked to a general program of dedifferentiation associated with the cancer phenotype. Diminution of hemoprotein in MLT may result in a relatively increased intracellular heme pool. delta-Aminolevulinic acid synthase and heme oxygenase are, respectively, negatively and positively regulated by heme. Thus, their alteration in MLT may be due to the regulatory influences of the heme pool

  6. Antithyroid microsomal antibody

    Science.gov (United States)

    Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb ... Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also been linked with an increased risk ...

  7. Tbx3 Promotes Liver Bud Expansion During Mouse Development by Suppression of Cholangiocyte Differentiation

    NARCIS (Netherlands)

    Lüdtke, Timo H.-W.; Christoffels, Vincent M.; Petry, Marianne; Kispert, Andreas

    2009-01-01

    After specification of the hepatic endoderm, mammalian liver organogenesis progresses through a series of morphological stages that culminate in the migration of hepatocytes into the underlying mesenchyme to populate the hepatic lobes. Here, we show that in the mouse the transcriptional repressor

  8. Studies on the metabolism of chlorotrianisene to a reactive intermediate and subsequent covalent binding to microsomal proteins

    International Nuclear Information System (INIS)

    Juedes, M.J.

    1989-01-01

    The studies on chlorotrianisene were conducted to determine whether metabolism of chlorotrianisene occurs via the cytochrome P450 monooxygenase system and whether a reactive intermediate is being formed that is capable of binding covalently to microsomal proteins. [ 3 H]-chlorotrianisene was incubated with liver microsomes supplemented with NADPH. At the termination of the incubation, the protein was trapped on a glass filter and the unbound chlorotrianisene was removed by extensive washing of the protein with organic solvent. A dramatic stimulation of covalent binding was demonstrated in microsomes from rats treated with methylcholanthrene (60 fold increase) versus control or phenobarbital treatment. Verification of covalent binding was achieved by localization of radiolabeled bands following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the macromolecules in the incubation mixture. Further analysis of the radiolabeled macromolecules separated on SDS-PAGE revealed that these macromolecules were degraded by protease degradation indicating that the macromolecules were proteins. Further investigations were done to determine the cause of the dramatic stimulation of covalent binding detected in microsomes from methylcholanthrene treated rats versus control or phenobarbital treated rats. Further evidence for the participation of P-450c was obtained with a reconstituted cytochrome P-450 system. Incubations of chlorotrianisene with reconstituted P-450c and NADPH-cytochrome P-450 reductase exhibited covalent binding characteristics comparable to those seen in microsomal incubations. Investigations into the nature of the binding site and the reactive intermediate are currently being conducted. By analyzing the BSA adduct, the author intends to isolate the specific amino acid binding site(s)

  9. Thymidine kinase 2 deficiency-induced mtDNA depletion in mouse liver leads to defect β-oxidation.

    Directory of Open Access Journals (Sweden)

    Xiaoshan Zhou

    Full Text Available Thymidine kinase 2 (TK2 deficiency in humans causes mitochondrial DNA (mtDNA depletion syndrome. To study the molecular mechanisms underlying the disease and search for treatment options, we previously generated and described a TK2 deficient mouse strain (TK2(-/- that progressively loses its mtDNA. The TK2(-/- mouse model displays symptoms similar to humans harboring TK2 deficient infantile fatal encephalomyopathy. Here, we have studied the TK2(-/- mouse model to clarify the pathological role of progressive mtDNA depletion in liver for the severe outcome of TK2 deficiency. We observed that a gradual depletion of mtDNA in the liver of the TK2(-/- mice was accompanied by increasingly hypertrophic mitochondria and accumulation of fat vesicles in the liver cells. The levels of cholesterol and nonesterified fatty acids were elevated and there was accumulation of long chain acylcarnitines in plasma of the TK2(-/- mice. In mice with hepatic mtDNA levels below 20%, the blood sugar and the ketone levels dropped. These mice also exhibited reduced mitochondrial β-oxidation due to decreased transport of long chain acylcarnitines into the mitochondria. The gradual loss of mtDNA in the liver of the TK2(-/- mice causes impaired mitochondrial function that leads to defect β-oxidation and, as a result, insufficient production of ketone bodies and glucose. This study provides insight into the mechanism of encephalomyopathy caused by TK2 deficiency-induced mtDNA depletion that may be used to explore novel therapeutic strategies.

  10. Thymidine kinase 2 deficiency-induced mtDNA depletion in mouse liver leads to defect β-oxidation.

    Science.gov (United States)

    Zhou, Xiaoshan; Kannisto, Kristina; Curbo, Sophie; von Döbeln, Ulrika; Hultenby, Kjell; Isetun, Sindra; Gåfvels, Mats; Karlsson, Anna

    2013-01-01

    Thymidine kinase 2 (TK2) deficiency in humans causes mitochondrial DNA (mtDNA) depletion syndrome. To study the molecular mechanisms underlying the disease and search for treatment options, we previously generated and described a TK2 deficient mouse strain (TK2(-/-)) that progressively loses its mtDNA. The TK2(-/-) mouse model displays symptoms similar to humans harboring TK2 deficient infantile fatal encephalomyopathy. Here, we have studied the TK2(-/-) mouse model to clarify the pathological role of progressive mtDNA depletion in liver for the severe outcome of TK2 deficiency. We observed that a gradual depletion of mtDNA in the liver of the TK2(-/-) mice was accompanied by increasingly hypertrophic mitochondria and accumulation of fat vesicles in the liver cells. The levels of cholesterol and nonesterified fatty acids were elevated and there was accumulation of long chain acylcarnitines in plasma of the TK2(-/-) mice. In mice with hepatic mtDNA levels below 20%, the blood sugar and the ketone levels dropped. These mice also exhibited reduced mitochondrial β-oxidation due to decreased transport of long chain acylcarnitines into the mitochondria. The gradual loss of mtDNA in the liver of the TK2(-/-) mice causes impaired mitochondrial function that leads to defect β-oxidation and, as a result, insufficient production of ketone bodies and glucose. This study provides insight into the mechanism of encephalomyopathy caused by TK2 deficiency-induced mtDNA depletion that may be used to explore novel therapeutic strategies.

  11. Monkey liver cytochrome P450 2C9 is involved in caffeine 7-N-demethylation to form theophylline.

    Science.gov (United States)

    Utoh, Masahiro; Murayama, Norie; Uno, Yasuhiro; Onose, Yui; Hosaka, Shinya; Fujino, Hideki; Shimizu, Makiko; Iwasaki, Kazuhide; Yamazaki, Hiroshi

    2013-12-01

    Caffeine (1,3,7-trimethylxanthine) is a phenotyping substrate for human cytochrome P450 1A2. 3-N-Demethylation of caffeine is the main human metabolic pathway, whereas monkeys extensively mediate the 7-N-demethylation of caffeine to form pharmacological active theophylline. Roles of monkey P450 enzymes in theophylline formation from caffeine were investigated using individual monkey liver microsomes and 14 recombinantly expressed monkey P450 enzymes, and the results were compared with those for human P450 enzymes. Caffeine 7-N-demethylation activity in microsomes from 20 monkey livers was not strongly inhibited by α-naphthoflavone, quinidine or ketoconazole, and was roughly correlated with diclofenac 4'-hydroxylation activities. Monkey P450 2C9 had the highest activity for caffeine 7-N-demethylation. Kinetic analysis revealed that monkey P450 2C9 had a high Vmax/Km value for caffeine 7-N-demethylation, comparable to low Km value for monkey liver microsomes. Caffeine could dock favorably with monkey P450 2C9 modeled for 7-N-demethylation and with human P450 1A2 for 3-N-demethylation. The primary metabolite theophylline was oxidized to 8-hydroxytheophylline in similar ways by liver microsomes and by recombinant P450s in both humans and monkeys. These results collectively suggest a high activity for monkey liver P450 2C9 toward caffeine 7-N-demethylation, whereas, in humans, P450 1A2-mediated caffeine 3-N-demethylation is dominant.

  12. Evaluation of immunological escape mechanisms in a mouse model of colorectal liver metastases

    International Nuclear Information System (INIS)

    Grimm, Martin; Thalheimer, Andreas; Gasser, Martin; Bueter, Marco; Strehl, Johanna; Wang, Johann; Nichiporuk, Ekaterina; Meyer, Detlef; Germer, Christoph T; Waaga-Gasser, Ana M

    2010-01-01

    The local and systemic activation and regulation of the immune system by malignant cells during carcinogenesis is highly complex with involvement of the innate and acquired immune system. Despite the fact that malignant cells do have antigenic properties their immunogenic effects are minor suggesting tumor induced mechanisms to circumvent cancer immunosurveillance. The aim of this study is the analysis of tumor immune escape mechanisms in a colorectal liver metastases mouse model at different points in time during tumor growth. CT26.WT murine colon carcinoma cells were injected intraportally in Balb/c mice after median laparotomy using a standardized injection technique. Metastatic tumor growth in the liver was examined by standard histological procedures at defined points in time during metastatic growth. Liver tissue with metastases was additionally analyzed for cytokines, T cell markers and Fas/Fas-L expression using immunohistochemistry, immunofluorescence and RT-PCR. Comparisons were performed by analysis of variance or paired and unpaired t test when appropriate. Intraportal injection of colon carcinoma cells resulted in a gradual and time dependent metastatic growth. T cells of regulatory phenotype (CD4+CD25+Foxp3+) which might play a role in protumoral immune response were found to infiltrate peritumoral tissue increasingly during carcinogenesis. Expression of cytokines IL-10, TGF-β and TNF-α were increased during tumor growth whereas IFN-γ showed a decrease of the expression from day 10 on following an initial increase. Moreover, liver metastases of murine colon carcinoma show an up-regulation of FAS-L on tumor cell surface with a decreased expression of FAS from day 10 on. CD8+ T cells express FAS and show an increased rate of apoptosis at perimetastatic location. This study describes cellular and macromolecular changes contributing to immunological escape mechanisms during metastatic growth in a colorectal liver metastases mouse model simulating the

  13. Effect of radio-detoxified endotoxin on the liver microsomal drug metabolizing enzyme system in rats

    International Nuclear Information System (INIS)

    Bertok, L.; Szeberenyi, S.

    1983-01-01

    E. coli endotoxin (LPS) depresses the hepatic microsomal mono-oxygenase activity. Radio-detoxified LPS (TOLERIN: 60 Co irradiated endotoxin preparation) decreases this biotransforming activity to a smaller extent. Phenobarbital, an inducer of this mono-oxygenase system, failed to induce in LPS-treated animals. In radio-detoxified LPS-treated rats, phenobarbital induced the mono-oxygenase and almost fully restored the biotransformation

  14. Gene Expression Profile Change and Associated Physiological and Pathological Effects in Mouse Liver Induced by Fasting and Refeeding

    Science.gov (United States)

    Zhang, Fang; Xu, Xiang; Zhou, Ben; He, Zhishui; Zhai, Qiwei

    2011-01-01

    Food availability regulates basal metabolism and progression of many diseases, and liver plays an important role in these processes. The effects of food availability on digital gene expression profile, physiological and pathological functions in liver are yet to be further elucidated. In this study, we applied high-throughput sequencing technology to detect digital gene expression profile of mouse liver in fed, fasted and refed states. Totally 12162 genes were detected, and 2305 genes were significantly regulated by food availability. Biological process and pathway analysis showed that fasting mainly affected lipid and carboxylic acid metabolic processes in liver. Moreover, the genes regulated by fasting and refeeding in liver were mainly enriched in lipid metabolic process or fatty acid metabolism. Network analysis demonstrated that fasting mainly regulated Drug Metabolism, Small Molecule Biochemistry and Endocrine System Development and Function, and the networks including Lipid Metabolism, Small Molecule Biochemistry and Gene Expression were affected by refeeding. In addition, FunDo analysis showed that liver cancer and diabetes mellitus were most likely to be affected by food availability. This study provides the digital gene expression profile of mouse liver regulated by food availability, and demonstrates the main biological processes, pathways, gene networks and potential hepatic diseases regulated by fasting and refeeding. These results show that food availability mainly regulates hepatic lipid metabolism and is highly correlated with liver-related diseases including liver cancer and diabetes. PMID:22096593

  15. Clofibric acid increases the formation of oleic acid in endoplasmic reticulum of the liver of rats.

    Science.gov (United States)

    Hirose, Akihiko; Yamazaki, Tohru; Sakamoto, Takeshi; Sunaga, Katsuyoshi; Tsuda, Tadashi; Mitsumoto, Atsushi; Kudo, Naomi; Kawashima, Yoichi

    2011-01-01

    The effects of 2-(4-chlorophenoxy)-2-methylpropionic acid (clofibric acid) on the formation of oleic acid (18:1) from stearic acid (18:0) and utilization of the 18:1 formed for phosphatidylcholine (PC) formation in endoplasmic reticulum in the liver of rats were studied in vivo. [¹⁴C]18:0 was intravenously injected into control Wistar male rats and rats that had been fed on a diet containing 0.5% (w/w) clofibric acid for 7 days; and the distribution of radiolabeled fatty acids among subcellular organelles, microsomes, peroxisomes, and mitochondria, was estimated on the basis of correction utilizing the yields from homogenates of marker enzymes for these organelles. The radioactivity was mostly localized in microsomes and the radiolabeled fatty acids present in microsomes were significantly increased by the treatment of rats with clofibric acid. The formation of radiolabeled 18:1 in microsomes markedly increased and incorporations of the formed [¹⁴C]18:1 into PC and phosphatidylethanolamine in microsomes were augmented in response to clofibric acid. The [¹⁴C]18:1 incorporated into PC was mostly located at the C-2 position, but not the C-1 position, of PC, and the radioactivity in 18:1 at the C-2 position of PC was strikingly increased by clofibric acid. These results obtained from the in vivo experiments directly link the findings that clofibric acid treatment induces microsomal stearoyl-CoA desaturase and 1-acylglycerophosphocholine acyltransferase in the liver and the findings that the treatment with the drug elevated absolute mass and mass proportion of 18:1 at the C-2 position, but not the C-1 position, of PC in the liver together.

  16. Genome-Wide Profiling of Liver X Receptor, Retinoid X Receptor, and Peroxisome Proliferator-Activated Receptor α in Mouse Liver Reveals Extensive Sharing of Binding Sites

    DEFF Research Database (Denmark)

    Boergesen, Michael; Pedersen, Thomas Åskov; Gross, Barbara

    2012-01-01

    and correlate with an LXR-dependent hepatic induction of lipogenic genes. To further investigate the roles of RXR and LXR in the regulation of hepatic gene expression, we have mapped the ligand-regulated genome-wide binding of these factors in mouse liver. We find that the RXR agonist bexarotene primarily......The liver X receptors (LXRs) are nuclear receptors that form permissive heterodimers with retinoid X receptor (RXR) and are important regulators of lipid metabolism in the liver. We have recently shown that RXR agonist-induced hypertriglyceridemia and hepatic steatosis in mice are dependent on LXRs...

  17. The tobacco carcinogen NNK is stereoselectively reduced by human pancreatic microsomes and cytosols.

    Science.gov (United States)

    Trushin, Neil; Leder, Gerhard; El-Bayoumy, Karam; Hoffmann, Dietrich; Beger, Hans G; Henne-Bruns, Doris; Ramadani, Marco; Prokopczyk, Bogdan

    2008-07-01

    Cigarette smoking increases the risk of cancer of the pancreas. The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the only known environmental compound that induces pancreatic cancer in laboratory animals. Concentrations of NNK are significantly higher in the pancreatic juice of smokers than in that of nonsmokers. The chiral NNK metabolite, (R,S)-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is itself a potent pancreatic carcinogen in rats. The carcinogenicity of NNAL is related to its stereochemistry; (S)-NNAL is a more potent lung tumorigen in the A/J mouse than is (R)-NNAL. In this study, we determined the potential of the human pancreas to convert NNK into NNAL. Human pancreatic microsomes and cytosols were incubated with [5-(3)H]NNK, and the metabolic products were determined by high-performance liquid chromatography (HPLC). (S)-NNAL was the predominant isomer formed in all cytosolic incubations. In ten microsomal samples, NNAL was formed at an average rate of 3.8 +/- 1.6 pmol/mg/min; (R)-NNAL was the predominant isomer in this group. The average rate of NNAL formation in 18 other microsomal samples was significantly lower, 0.13 +/- 0.12 pmol/mg/min (p < 0.001); (S)-NNAL was the predominant isomer formed in this group. In human pancreatic tissues, there is intraindividual variability regarding the capacity for, and stereoselectivity of, carbonyl reduction of NNK.

  18. Autoimmune hepatitis-specific antibodies against soluble liver antigen and liver cytosol type 1 in patients with chronic viral hepatitis

    OpenAIRE

    Rigopoulou, Eirini I; Mytilinaiou, Maria; Romanidou, Ourania; Liaskos, Christos; Dalekos, George N

    2007-01-01

    Background Non-organ specific autoantibodies are highly prevalent in patients with chronic hepatitis C (HCV). Among them, anti-liver kidney microsomal type 1 (LKM1) antibody – the serological marker of type 2 autoimmune hepatitis (AIH-2)- is detected in up to 11% of the HCV-infected subjects. On the other hand, anti-liver cytosol type 1 antibodies (anti-LC1) – either in association with anti-LKM1, or in isolation- and anti-soluble liver antigen antibodies (anti-SLA) have been considered as us...

  19. MicroRNA regulation in Ames dwarf mouse liver may contribute to delayed aging.

    Science.gov (United States)

    Bates, David J; Li, Na; Liang, Ruqiang; Sarojini, Harshini; An, Jin; Masternak, Michal M; Bartke, Andrzej; Wang, Eugenia

    2010-02-01

    The Ames dwarf mouse is well known for its remarkable propensity to delay the onset of aging. Although significant advances have been made demonstrating that this aging phenotype results primarily from an endocrine imbalance, the post-transcriptional regulation of gene expression and its impact on longevity remains to be explored. Towards this end, we present the first comprehensive study by microRNA (miRNA) microarray screening to identify dwarf-specific lead miRNAs, and investigate their roles as pivotal molecular regulators directing the long-lived phenotype. Mapping the signature miRNAs to the inversely expressed putative target genes, followed by in situ immunohistochemical staining and in vitro correlation assays, reveals that dwarf mice post-transcriptionally regulate key proteins of intermediate metabolism, most importantly the biosynthetic pathway involving ornithine decarboxylase and spermidine synthase. Functional assays using 3'-untranslated region reporter constructs in co-transfection experiments confirm that miRNA-27a indeed suppresses the expression of both of these proteins, marking them as probable targets of this miRNA in vivo. Moreover, the putative repressed action of this miRNA on ornithine decarboxylase is identified in dwarf mouse liver as early as 2 months of age. Taken together, our results show that among the altered aspects of intermediate metabolism detected in the dwarf mouse liver--glutathione metabolism, the urea cycle and polyamine biosynthesis--miRNA-27a is a key post-transcriptional control. Furthermore, compared to its normal siblings, the dwarf mouse exhibits a head start in regulating these pathways to control their normality, which may ultimately contribute to its extended health-span and longevity.

  20. A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis.

    Directory of Open Access Journals (Sweden)

    Nina Fransén-Pettersson

    Full Text Available Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders.

  1. Evaluation of the Role of Peroxisome Proliferator-Activated Receptor α (PPARα) in Mouse Liver Tumor Induction by Trichloroethylene and Metabolites

    Science.gov (United States)

    Trichloroethylene (TCE) is an industrial solvent and a widespread environmental contaminant. Induction of liver cancer in mice by TCE is thought to be mediated by two metabolites, dichloroacetate (DCA) and trichloroacetate (TCA), both of which are themselves mouse liver carcinoge...

  2. In vitro inactivation of hepatic microsomal phospholipase A/sub 2/ by the marine natural product manoalide

    Energy Technology Data Exchange (ETDEWEB)

    Master, M.M.; Jacobs, R.S.

    1986-03-01

    The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A/sub 2/ (PLA/sub 2/) activity was investigated. Microsomal PLA/sub 2/, a membrane bound, Ca/sup + +/ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA/sub 2/ activity was assayed by preincubating MLD or analogs (2.5-100..mu..M) with microsomes for 60 min. at 37/sup 0/C, combining this mixture with /sup 14/C-phosphatidylcholine and CaCl/sub 2/, and incubating at 37/sup 0/C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted /sup 14/C-arachidonic acid product. MLD inhibited PLA/sub 2/ in a dose-dependent manner, with an IC/sub 50/ = 94..mu..M. Lineweaver-Burk analysis suggests that MLD inhibits PLA/sub 2/ noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC/sub 50/ = 33..mu..M). Another analog facilitated PLA/sub 2/ activity (15%) at 25..mu..M, followed by inactivation at higher doses (IC/sub 50/ > 100 ..mu..M). Facilitation of PLA/sub 2/ activity was seen with concentrations as low as 2.5..mu..M of a third analog, and significant inactivation of PLA/sub 2/ was evident. These results indicate that MLD is not as potent against microsomal PLA/sub 2/ as has been shown with purified bee venom and cobra venom PLA/sub 2/'s.

  3. Chimeric mice with humanized liver: Application in drug metabolism and pharmacokinetics studies for drug discovery.

    Science.gov (United States)

    Naritomi, Yoichi; Sanoh, Seigo; Ohta, Shigeru

    2018-02-01

    Predicting human drug metabolism and pharmacokinetics (PK) is key to drug discovery. In particular, it is important to predict human PK, metabolite profiles and drug-drug interactions (DDIs). Various methods have been used for such predictions, including in vitro metabolic studies using human biological samples, such as hepatic microsomes and hepatocytes, and in vivo studies using experimental animals. However, prediction studies using these methods are often inconclusive due to discrepancies between in vitro and in vivo results, and interspecies differences in drug metabolism. Further, the prediction methods have changed from qualitative to quantitative to solve these issues. Chimeric mice with humanized liver have been developed, in which mouse liver cells are mostly replaced with human hepatocytes. Since human drug metabolizing enzymes are expressed in the liver of these mice, they are regarded as suitable models for mimicking the drug metabolism and PK observed in humans; therefore, these mice are useful for predicting human drug metabolism and PK. In this review, we discuss the current state, issues, and future directions of predicting human drug metabolism and PK using chimeric mice with humanized liver in drug discovery. Copyright © 2017 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  4. In vitro screening of reversible and time-dependent inhibition on CYP3A by TM208 and TM209 in rat liver microsomes

    Directory of Open Access Journals (Sweden)

    Miaoran Ning

    2012-04-01

    Full Text Available TM208 and TM209, dithiocarbamate derivatives with potential anti-cancer effects, were evaluated in reversible and time-dependent cytochrome P450 (CYP 3A inhibition assays in rat liver microsomes using testosterone as probe substrate. Both compounds were found to be weak reversible inhibitors and moderate mechanism-based inhibitors of rat CYP3A. For reversible inhibition on rat CYP3A, the Ki values of competitive inhibition model were 12.10±1.75 and 13.94±1.31 μM, respectively. For time-dependent inhibition, the inactivation constants (Kl were 31.93±12.64 and 32.91±15.58 μM, respectively, and the maximum inactivation rates (kinact were 0.03497±0.0069 and 0.07259±0.0172 min−1 respectively. These findings would provide useful in vitro information for future in vivo DDI studies on TM208 or TM209.

  5. Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

    Energy Technology Data Exchange (ETDEWEB)

    Kazantseva, Yuliya A.; Yarushkin, Andrei A. [Institute of Molecular Biology and Biophysics SB RAMS, Novosibirsk, Timakova str., 2, 630117 (Russian Federation); Pustylnyak, Vladimir O., E-mail: pustylnyak@ngs.ru [Institute of Molecular Biology and Biophysics SB RAMS, Novosibirsk, Timakova str., 2, 630117 (Russian Federation); Novosibirsk State University, Novosibirsk, Pirogova str., 2, 630090 (Russian Federation)

    2013-09-01

    Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CAR and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell

  6. Dichlorodiphenyltrichloroethane technical mixture regulates cell cycle and apoptosis genes through the activation of CAR and ERα in mouse livers

    International Nuclear Information System (INIS)

    Kazantseva, Yuliya A.; Yarushkin, Andrei A.; Pustylnyak, Vladimir O.

    2013-01-01

    Dichlorodiphenyltrichloroethane (DDT) is a widely used organochlorine pesticide and a xenoestrogen that promotes rodent hepatomegaly and tumours. A recent study has shown significant correlation between DDT serum concentration and liver cancer incidence in humans, but the underlying mechanisms remain elusive. We hypothesised that a mixture of DDT isomers could exert effects on the liver through pathways instead of classical ERs. The acute effects of a DDT mixture containing the two major isomers p,p′-DDT (85%) and o,p′-DDT (15%) on CAR and ERα receptors and their cell cycle and apoptosis target genes were studied in mouse livers. ChIP results demonstrated increased CAR and ERα recruitment to their specific target gene binding sites in response to the DDT mixture. The results of real-time RT-PCR were consistent with the ChIP data and demonstrated that the DDT was able to activate both CAR and ERα in mouse livers, leading to target gene transcriptional increases including Cyp2b10, Gadd45β, cMyc, Mdm2, Ccnd1, cFos and E2f1. Western blot analysis demonstrated increases in cell cycle progression proteins cMyc, Cyclin D1, CDK4 and E2f1 and anti-apoptosis proteins Mdm2 and Gadd45β. In addition, DDT exposure led to Rb phosphorylation. Increases in cell cycle progression and anti-apoptosis proteins were accompanied by a decrease in p53 content and its transcriptional activity. However, the DDT was unable to stimulate the β-catenin signalling pathway, which can play an important role in hepatocyte proliferation. Thus, our results indicate that DDT treatment may result in cell cycle progression and apoptosis inhibition through CAR- and ERα-mediated gene activation in mouse livers. These findings suggest that the proliferative and anti-apoptotic conditions induced by CAR and ERα activation may be important contributors to the early stages of hepatocarcinogenesis as produced by DDT in rodent livers. - Highlights: • DDT activated both CAR and ERα and their cell

  7. Effect of Curcuma longa on CYP2D6- and CYP3A4-mediated metabolism of dextromethorphan in human liver microsomes and healthy human subjects.

    Science.gov (United States)

    Al-Jenoobi, Fahad Ibrahim; Al-Thukair, Areej A; Alam, Mohd Aftab; Abbas, Fawkeya A; Al-Mohizea, Abdullah M; Alkharfy, Khalid M; Al-Suwayeh, Saleh A

    2015-03-01

    Effect of Curcuma longa rhizome powder and its ethanolic extract on CYP2D6 and CYP3A4 metabolic activity was investigated in vitro using human liver microsomes and clinically in healthy human subjects. Dextromethorphan (DEX) was used as common probe for CYP2D6 and CYP3A4 enzymes. Metabolic activity of CYP2D6 and CYP3A4 was evaluated through in vitro study; where microsomes were incubated with NADPH in presence and absence of Curcuma extract. In clinical study phase-I, six healthy human subjects received a single dose (30 mg) of DEX syrup, and in phase-II DEX syrup was administered with Curcuma powder. The enzyme CYP2D6 and CYP3A4 mediated O- and N-demethylation of dextromethorphan into dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. Curcuma extract significantly inhibited the formation of DOR and 3-MM, in a dose-dependent and linear fashion. The 100 μg/ml dose of curcuma extract produced highest inhibition, which was about 70 % for DOR and 80 % for 3-MM. Curcuma significantly increases the urine metabolic ratio of DEX/DOR but the change in DEX/3-MM ratio was statistically insignificant. Present findings suggested that curcuma significantly inhibits the activity of CYP2D6 in in vitro as well as in vivo; which indicates that curcuma has potential to interact with CYP2D6 substrates.

  8. Selective inhibition by chloramphenicol of pregnenolone-16 α-carbonitrile-inducible rat liver cytochrome P-450 isozymes

    International Nuclear Information System (INIS)

    Graves, P.E.; Kaminsky, L.S.; Halpert, J.

    1986-01-01

    Pregnenolone-16 α-carbonitrile (PCN) has been shown to induce, in male rats, cytochrome P-450 isozymes responsible for the formation of R-10-hydroxywarfarin and R-dehydrowarfarin. Antibodies to the major PCN-inducible isozyme (PB/PCN-E) inhibit both activities in microsomal preparations. Recently the authors have shown that PCN treatment of female rats also induces the formation of both R-warfarin metabolites. However, in both sexes chloramphenicol (CAP) treatment selectively inhibits only the rate of formation of the R-dehydrowarfarin. A decrease in microsomal P-450 content occurs after in vivo administration of CAP to PCN-treated rats of both sexes. This is in contrast to the lack of effect of CAP on P-450 levels in phenobarbital-treated rats. Covalent binding of 14 C-CAP to microsomal protein in vitro was increased 3 to 4-fold following PCN treatment. Chromatographic evidences suggests the presence of at least two PCN-induced isozymes of similar molecular weights in both male and female rat liver microsomes. These data are consistent with the multiplicity of PCN-inducible P-450 in rat liver

  9. Promiscuous activity of the LXR antagonist GSK2033 in a mouse model of fatty liver disease

    International Nuclear Information System (INIS)

    Griffett, Kristine; Burris, Thomas P.

    2016-01-01

    The liver X receptor (LXR) functions as a receptor for oxysterols and plays a critical role in the regulation of glucose and lipid metabolism. We recently described a synthetic LXR inverse agonist that displayed efficacy in treatment of hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD). This compound, SR9238, was designed to display liver specificity so as to avoid potential detrimental effects on reverse cholesterol transport in peripheral tissues. Here, we examined the effects of a LXR antagonist/inverse agonist, GSK2033, which displays systemic exposure. Although GSK2033 performed as expected in cell-based models as a LXR inverse agonist, it displayed unexpected activity in the mouse NAFLD model. The expression of lipogenic enzyme genes such as fatty acid synthase and sterol regulatory binding protein 1c were induced rather than suppressed and no effect on hepatic steatosis was found. Further characterization of the specificity of GSK2033 revealed that it displayed a significant degree of promiscuity, targeting a number of other nuclear receptors that could clearly alter hepatic gene expression. - Highlights: • The LXR antagonist GSK2033 suppresses the expression of lipogenic genes FASN and SREBF1 in HepG2 cells. • GSK2033 exhibits sufficient exposure to perform animal experiments targeting the liver. • GSK2033 has fails to suppress hepatic Fasn and Srebf1 expression in an animal model of non-alcoholic fatty liver disease. • GSK2033 may regulate the activity of several nuclear receptors.

  10. Cytotoxicity of MEIC chemicals Nos. 11-30 in 3T3 mouse fibroblasts with and without microsomal activation

    DEFF Research Database (Denmark)

    Rasmussen, Eva

    1999-01-01

    acid, propranolol, thioridazine, lithium sulfate, copper sulfate and thallium sulfate, whereas the cytotoxicity of 1,1,1-trichloroethylene, phenol, nicotine, and paraquat was significantly increased by use of the microsomal activation mixture. These cytotoxicity data are in line with observations...

  11. Liver microsomal fraction is known to participate in:

    African Journals Online (AJOL)

    Abdullahi Balarabe

    Bayero Journal of Pure and Applied Sciences, 5(1): 11 – 16. Received: November 2011 ... of diet rich in fruit and vegetable may decrease the risk of cancer ((Steinmetz .... during analysis and experiment. The differences .... the liver mitochondrial membrane (Balzan et al.,. 1999). .... and Plasma Malondialdehyde in Human.

  12. Sera of children with hepatitis C infection and anti-liver-kidney microsome-1 antibodies recognize different CYP2D6 epitopes than adults with LKM+/HCV+ sera.

    Science.gov (United States)

    Herzog, D; Yamamoto, A M; Jara, P; Maggiore, G; Sarles, J; Alvarez, F

    1999-11-01

    Liver-kidney microsome type 1 (LKM1) antibodies are specific markers of autoimmune hepatitis (AIH) type 2. Antibodies to LKM1 have been found in 2% to 3% of adults infected with hepatitis C virus (HCV) without AIH. Thirty percent of these antibodies are directed against linear sequences of CYP2D6 protein. LKM1 antibodies in HCV+/LKM1+ sera and in sera of AIH patients do not recognize the same CYP2D6 epitopes. The current study was conducted to determine whether LKM1 antibodies in HCV+/LKM1+ children's sera are the result of the same immune response as the antibodies described in AIH type 2 and in HCV+/LKM1+ adult patients. Sera from 10 HCV+/LKM1+ children were tested against human liver microsomal and cytosolic proteins by Western blot analysis and against synthetic peptides of the CYP2D6 sequence between amino acids 200 and 429 by dot blot. The same sera were tested against radiolabeled CYP2D6 by immunoprecipitation. Four of 10 sera tested by Western blot analysis showed immunoglobulin (Ig) G-type antibodies against CYP2D6, and 2 had antibodies against proteins of 58, 66, and 84 kDa. One of the sera also contained IgM-type anti-66-kDa and 84-kDa proteins. The radioligand test detected anti-CYP2D6 antibodies in 9 of 10 patients. Five of the anti-CYP2D6-positive sera recognized a peptide between amino acids 200 and 429 including amino acids 254-271. Most HCV+/LKM1+ sera from children recognize conformational epitopes of the CYP2D6 antigen, and half recognize linear epitopes. Some HCV+/LKM1+ sera demonstrated antibodies against the AIH type 2 main antigenic site of the CYP2D6. Screening of HCV RNA should be performed before starting treatment of presumed autoimmune hepatitis associated with LKM1.

  13. Quantitative Characterization of Major Hepatic UDP-Glucuronosyltransferase Enzymes in Human Liver Microsomes: Comparison of Two Proteomic Methods and Correlation with Catalytic Activity.

    Science.gov (United States)

    Achour, Brahim; Dantonio, Alyssa; Niosi, Mark; Novak, Jonathan J; Fallon, John K; Barber, Jill; Smith, Philip C; Rostami-Hodjegan, Amin; Goosen, Theunis C

    2017-10-01

    Quantitative characterization of UDP-glucuronosyltransferase (UGT) enzymes is valuable in glucuronidation reaction phenotyping, predicting metabolic clearance and drug-drug interactions using extrapolation exercises based on pharmacokinetic modeling. Different quantitative proteomic workflows have been employed to quantify UGT enzymes in various systems, with reports indicating large variability in expression, which cannot be explained by interindividual variability alone. To evaluate the effect of methodological differences on end-point UGT abundance quantification, eight UGT enzymes were quantified in 24 matched liver microsomal samples by two laboratories using stable isotope-labeled (SIL) peptides or quantitative concatemer (QconCAT) standard, and measurements were assessed against catalytic activity in seven enzymes ( n = 59). There was little agreement between individual abundance levels reported by the two methods; only UGT1A1 showed strong correlation [Spearman rank order correlation (Rs) = 0.73, P quantitative proteomic data should be validated against catalytic activity whenever possible. In addition, metabolic reaction phenotyping exercises should consider spurious abundance-activity correlations to avoid misleading conclusions. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  14. Hepatoprotective Effects of Antrodia cinnamomea: The Modulation of Oxidative Stress Signaling in a Mouse Model of Alcohol-Induced Acute Liver Injury

    Directory of Open Access Journals (Sweden)

    Yange Liu

    2017-01-01

    Full Text Available In the present study, the components of A. cinnamomea (AC mycelia were systematically analyzed. Subsequently, its hepatoprotective effects and the underlying mechanisms were explored using a mouse model of acute alcohol-induced liver injury. AC contained 25 types of fatty acid, 16 types of amino acid, 3 types of nucleotide, and 8 types of mineral. The hepatoprotective effects were observed after 2 weeks of AC treatment at doses of 75 mg/kg, 225 mg/kg, and 675 mg/kg in the mouse model. These effects were indicated by the changes in the levels of aspartate aminotransferase, alanine aminotransferase, several oxidation-related factors, and inflammatory cytokines in serum and/or liver samples. AC reduced the incidence rate of necrosis, inflammatory infiltration, fatty droplets formation, and cell apoptosis in liver detecting via histological and TUNEL assay. In addition, AC reduced the expression of cleaved caspase-3, -8, and -9 and the levels of phosphor-protein kinase B (Akt and phosphor-nuclear factor-κB (NF-κB in the liver samples. Collectively, AC-mediated hepatoprotective effects in a mouse model of acute alcohol-induced liver injury are the result of reduction in oxidative stress. This may be associated with Akt/NF-κB signaling. These results provide valuable evidence to support the use of A. cinnamomea as a functional food and/or medicine.

  15. Toxicogenomic Dissection of the Perfluorooctanoic Acid Transcript Profile in Mouse Liver: Evidence for Involvement of the Nuclear Receptors PPARα and CAR

    Science.gov (United States)

    A number of perfluorinated alkyl acids including perfluorooctanoic acid (PFOA) elicit effects similar to peroxisome proliferator chemicals (PPC) in mouse and rat liver. There is strong evidence that PPC cause many of their effects related to liver carcinogenesis through the nucle...

  16. Role of cytochrome P450 IA2 in acetanilide 4-hydroxylation as determined with cDNA expression and monoclonal antibodies.

    Science.gov (United States)

    Liu, G; Gelboin, H V; Myers, M J

    1991-02-01

    The role of P450 IA2 in the hydroxylation of acetanilide was examined using an inhibitory monoclonal antibody (MAb) 1-7-1 and vaccinia cDNA expression producing murine P450 IA1 (mIA1), murine P450 IA2 (mIA2), or human P450 IA2 (hIA2). Acetanilide hydroxylase (AcOH) activity was measured using an HPLC method with more than 500-fold greater sensitivity than previously described procedures. This method, which does not require the use of radioactive acetanilide, was achieved by optimizing both the gradient system and the amount of enzyme needed to achieve detection by uv light. MAb 1-7-1 inhibits up to 80% of the AcOH activity in both rat liver microsomes and cDNA expressed mouse and human P450 IA2. MAb 1-7-1, which recognizes both P450 IA1 and P450 IA2, completely inhibits the aryl hydrocarbon hydroxylase (AHH) activity of cDNA expressed in IA1. The inhibition of only 80% of the AHH activity present in MC liver microsomes by MAb 1-7-1 suggests that additional P450 forms are contributing to the overall AHH activity present in methylcholanthrene (MC)-liver microsomes as MAb 1-7-1 almost completely inhibits the AHH activity of expressed mIA1. Maximal inhibition of IA2 by 1-7-1 results in an 80% decrease in acetanilide hydroxylase activity in both liver microsomes and expressed mouse and human IA2. The capacity of MAb 1-7-1 to produce identical levels of inhibition of acetanilide hydroxylase activity in rat MC microsomes (80%) and in expressed mouse (81%) and human P450 IA2 (80%) strongly suggests that P450 IA2 is the major and perhaps the only enzyme responsible for the metabolism of acetanilide. These results demonstrate the complementary utility of monoclonal antibodies and cDNA expression for defining the contribution of specific P450 enzymes to the metabolism of a given substrate. This complementary approach allows for a more precise determination of the inhibitory capacity of MAb with respect to the metabolic capacity of the target P450.

  17. Overexpression of the long noncoding RNA TUG1 protects against cold-induced injury of mouse livers by inhibiting apoptosis and inflammation.

    Science.gov (United States)

    Su, Song; Liu, Jiang; He, Kai; Zhang, Mengyu; Feng, Chunhong; Peng, Fangyi; Li, Bo; Xia, Xianming

    2016-04-01

    Hepatic injury provoked by cold storage is a major problem affecting liver transplantation, as exposure to cold induces apoptosis in hepatic tissues. Long noncoding RNAs (lncRNAs) are increasingly understood to regulate apoptosis, but the contribution of lncRNAs to cold-induced liver injury remains unknown. Using RNA-seq, we determined the differential lncRNA expression profile in mouse livers after cold storage and found that expression of the lncRNA TUG1 was significantly down-regulated. Overexpression of TUG1 attenuated cold-induced apoptosis in mouse hepatocytes and liver sinusoidal endothelial cells LSECs, in part by blocking mitochondrial apoptosis and endoplasmic reticulum (ER) stress pathways. Moreover, TUG1 attenuated apoptosis, inflammation, and oxidative stress in vivo in livers subjected to cold storage. Overexpression of TUG1 also improved hepatocyte function and prolonged hepatic graft survival rates in mice. These results suggest that the lncRNA TUG1 exerts a protective effect against cold-induced liver damage by inhibiting apoptosis in mice, and suggests a potential role for TUG1 as a target for the prevention of cold-induced liver damage in liver transplantation. RNA-seq data are available from GEO using accession number GSE76609. © 2016 Federation of European Biochemical Societies.

  18. Toxicogenomic Dissection of the Perfluorooctanoic Acid Transcript Profile in Mouse Liver: Evidence for the Involvement of Nuclear Receptors PPARα and CAR

    Science.gov (United States)

    A number of perfluorinated alkyl acids including perfluorooctanoic acid (PFOA) elicit effects similar to peroxisome proliferator chemicals (PPC) in mouse and rat liver. There is strong evidence that PPC cause many of their effects linked to liver cancer through the nuclear recep...

  19. Development of Murine Cyp3a Knockout Chimeric Mice with Humanized Liver.

    Science.gov (United States)

    Kato, Kota; Ohbuchi, Masato; Hamamura, Satoko; Ohshita, Hiroki; Kazuki, Yasuhiro; Oshimura, Mitsuo; Sato, Koya; Nakada, Naoyuki; Kawamura, Akio; Usui, Takashi; Kamimura, Hidetaka; Tateno, Chise

    2015-08-01

    We developed murine CYP3A knockout ko chimeric mice with humanized liver expressing human P450S similar to those in humans and whose livers and small intestines do not express murine CYP3A this: approach may overcome effects of residual mouse metabolic enzymes like Cyp3a in conventional chimeric mice with humanized liver, such as PXB-mice [urokinase plasminogen activator/severe combined immunodeficiency (uPA/SCID) mice repopulated with over 70% human hepatocytes] to improve the prediction of drug metabolism and pharmacokinetics in humans. After human hepatocytes were transplanted into Cyp3a KO/uPA/SCID host mice, human albumin levels logarithmically increased until approximately 60 days after transplantation, findings similar to those in PXB-mice. Quantitative real-time-polymerase chain reaction analyses showed that hepatic human P450s, UGTs, SULTs, and transporters mRNA expression levels in Cyp3a KO chimeric mice were also similar to those in PXB-mice and confirmed the absence of Cyp3a11 mRNA expression in mouse liver and intestine. Findings for midazolam and triazolam metabolic activities in liver microsomes were comparable between Cyp3a KO chimeric mice and PXB-mice. In contrast, these activities in the intestine of Cyp3a KO chimeric mice were attenuated compared with PXB-mice. Owing to the knockout of murine Cyp3a, hepatic Cyp2b10 and 2c55 mRNA levels in Cyp3a KO/uPA/SCID mice (without hepatocyte transplants) were 8.4- and 61-fold upregulated compared with PXB-mice, respectively. However, human hepatocyte transplantation successfully restored Cyp2b10 level nearly fully and Cyp2c55 level partly (still 13-fold upregulated) compared with those in PXB-mice. Intestinal Cyp2b10 and 2c55 were also repressed by human hepatocyte transplantation in Cyp3a KO chimeric mice. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  20. Imaging of pharmacokinetic rates of indocyanine green in mouse liver with a hybrid fluorescence molecular tomography/x-ray computed tomography system.

    Science.gov (United States)

    Zhang, Guanglei; Liu, Fei; Zhang, Bin; He, Yun; Luo, Jianwen; Bai, Jing

    2013-04-01

    Pharmacokinetic rates have the potential to provide quantitative physiological and pathological information for biological studies and drug development. Fluorescence molecular tomography (FMT) is an attractive imaging tool for three-dimensionally resolving fluorophore distribution in small animals. In this letter, pharmacokinetic rates of indocyanine green (ICG) in mouse liver are imaged with a hybrid FMT and x-ray computed tomography (XCT) system. A recently developed FMT method using structural priors from an XCT system is adopted to improve the quality of FMT reconstruction. In the in vivo experiments, images of uptake and excretion rates of ICG in mouse liver are obtained, which can be used to quantitatively evaluate liver function. The accuracy of the results is validated by a fiber-based fluorescence measurement system.

  1. The iron-responsive microsomal proteome of Aspergillus fumigatus.

    Science.gov (United States)

    Moloney, Nicola M; Owens, Rebecca A; Meleady, Paula; Henry, Michael; Dolan, Stephen K; Mulvihill, Eoin; Clynes, Martin; Doyle, Sean

    2016-03-16

    Aspergillus fumigatus is an opportunistic fungal pathogen. Siderophore biosynthesis and iron acquisition are essential for virulence. Yet, limited data exist with respect to the adaptive nature of the fungal microsomal proteome under iron-limiting growth conditions, as encountered during host infection. Here, we demonstrate that under siderophore biosynthetic conditions--significantly elevated fusarinine C (FSC) and triacetylfusarinine C (TAFC) production (pproteome remodelling occurs. Specifically, a four-fold enrichment of transmembrane-containing proteins was observed with respect to whole cell lysates following ultracentrifugation-based microsomal extraction. Comparative label-free proteomic analysis of microsomal extracts, isolated following iron-replete and -deplete growth, identified 710 unique proteins. Scatterplot analysis (MaxQuant) demonstrated high correlation amongst biological replicates from each growth condition (Pearson correlation >0.96 within groups; biological replicates (n=4)). Quantitative and qualitative comparison revealed 231 proteins with a significant change in abundance between the iron-replete and iron-deplete conditions (pAspergillus fumigatus must acquire iron to facilitate growth and pathogenicity. Iron-chelating non-ribosomal peptides, termed siderophores, mediate iron uptake via membrane-localised transporter proteins. Here we demonstrate for the first time that growth of A. fumigatus under iron-deplete conditions, concomitant with siderophore biosynthesis, leads to an extensive remodelling of the microsomal proteome which includes significantly altered levels of 231 constituent proteins (96 increased and 135 decreased in abundance), many of which have not previously been localised to the microsome. We also demonstrate the first synthesis of a fluorescent version of fusarinine C, an extracellular A. fumigatus siderophore, and its uptake and localization under iron-restricted conditions. This infers the use of an A. fumigatus

  2. Amelioration of radiation induced decrease in activity of catalase and superoxide dismutase in mouse liver by Punica granatum

    International Nuclear Information System (INIS)

    Sharma, Jaimala; Mathur, Aarti

    2013-01-01

    Ionizing radiation generates reactive oxygen species (ROS) in irradiated tissue. Cells of liver have their own defence system, the antioxidant system to deactivate ROS. Antioxidant system includes enzymatic and non-enzymatic components. Liver is rich in endogenous antioxidants and related enzymes. Catalase and Superoxide dismutase (SOD) are powerful antioxidant enzymes. In the present study Punica granatum fruit rind Ethanol extract (PGFRE) was tested against 60 Co gamma radiation induced alteration in Swiss albino mouse. Healthy adult (25±2) Swiss albino mouse were selected and divided into four groups. The first group was sham irradiated. The second group was irradiated with 8 Gy 60 Co gamma radiation only and served as control. The third group was administered with Ethanol extract of Punica granatum fruit rind one hour before irradiation at the dose rate of 10 mg/kg body weight orally. Animals were exposed to 8 Gy 60 Co gamma radiation. Fourth group was administered with Ethanol extract of Punica granatum fruit rind at the dose rate of 10 mg/kg body weight. Mice were sacrificed at various post irradiation intervals and liver was removed, weighed and analysed biochemically for Catalase and SOD activity. Catalase and SOD activity decreased up till 7th post irradiation day in 8 Gy irradiated group than normal. In PGFRE pretreated irradiated group catalase and SOD activity were higher than the corresponding control group at all the intervals. These results indicate that PGFRE extract protects damage to the catalase and SOD activity in liver of Swiss albino mouse against lethal dose of gamma radiation. (author)

  3. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    International Nuclear Information System (INIS)

    Sugumaran, G.; Silbert, J.E.

    1988-01-01

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

  4. Effect of adeturone on the concentration of endogenous sulfhydryl groups in mouse spleen and liver

    International Nuclear Information System (INIS)

    Pantev, T.; Bychvarova, K.

    1981-01-01

    Levels of endogenous sulfhydryl groups (total, protein, and non-protein) in mouse liver and spleen were studied for response to the radioprotective drug Adeturone (AET adenosine triphosphate) as recorded at various time intervals (5 - 90 min) following administration of a 300 mg/kg b.w. dose. Spleen sulfhydryl concentration levels tended to elevation, with the peak effect noted at 45 min post-treatment. In the liver, augmentation was observed only for non-protein sylfhydryl groups, at 10 and 15 min post-treatment (time intervals when Adeturone affords maximum protection against radiation); at the 60 min, however, there was a statistically reliable drop. The findings indicate that Adeturone treatment produces response patterns of opposite directions in liver and spleen endogenous thiols. (A.B.)

  5. Completion of hepatitis C virus replication cycle in heterokaryons excludes dominant restrictions in human non-liver and mouse liver cell lines.

    Directory of Open Access Journals (Sweden)

    Anne Frentzen

    2011-04-01

    Full Text Available Hepatitis C virus (HCV is hepatotropic and only infects humans and chimpanzees. Consequently, an immunocompetent small animal model is lacking. The restricted tropism of HCV likely reflects specific host factor requirements. We investigated if dominant restriction factors expressed in non-liver or non-human cell lines inhibit HCV propagation thus rendering these cells non-permissive. To this end we explored if HCV completes its replication cycle in heterokaryons between human liver cell lines and non-permissive cell lines from human non-liver or mouse liver origin. Despite functional viral pattern recognition pathways and responsiveness to interferon, virus production was observed in all fused cells and was only ablated when cells were treated with exogenous interferon. These results exclude that constitutive or virus-induced expression of dominant restriction factors prevents propagation of HCV in these cell types, which has important implications for HCV tissue and species tropism. In turn, these data strongly advocate transgenic approaches of crucial human HCV cofactors to establish an immunocompetent small animal model.

  6. Grapefruit juice intake does not enhance but rather protects against aflatoxin B1-induced liver DNA damage through a reduction in hepatic CYP3A activity.

    Science.gov (United States)

    Miyata, Masaaki; Takano, Hiroki; Guo, Lian Q; Nagata, Kiyoshi; Yamazoe, Yasushi

    2004-02-01

    Influence of grapefruit juice intake on aflatoxin B1 (AFB1)-induced liver DNA damage was examined using a Comet assay in F344 rats given 5 mg/kg AFB1 by gavage. Rats allowed free access to grapefruit juice for 5 days prior to AFB1 administration resulted in clearly reduced DNA damage in liver, to 65% of the level in rats that did not receive grapefruit juice. Furthermore, rats treated with grapefruit juice extract (100 mg/kg per os) for 5 days prior to AFB1 treatment also reduced the DNA damage to 74% of the level in rats that did not receive grapefruit juice. No significant differences in the portal blood and liver concentrations of AFB1 were observed between grapefruit juice intake rats and the controls. In an Ames assay with AFB1 using Salmonella typhimurium TA98, lower numbers of revertant colonies were detected with hepatic microsomes prepared from rats administered grapefruit juice, compared with those from control rats. Microsomal testosterone 6beta-hydroxylation was also lower with rats given grapefruit juice than with control rats. Immunoblot analyses showed a significant decrease in hepatic CYP3A content, but not CYP1A and CYP2C content, in microsomes of grapefruit juice-treated rats than in non-treated rats. No significant difference in hepatic glutathione S-transferase (GST) activity and glutathione content was observed in the two groups. GSTA5 protein was not detected in hepatic cytosol of the two groups. In microsomal systems, grapefruit juice extract inhibited AFB1-induced mutagenesis in the presence of a microsomal activation system from livers of humans as well as rats. These results suggest that grapefruit juice intake suppresses AFB1-induced liver DNA damage through inactivation of the metabolic activation potency for AFB1 in rat liver.

  7. Heterogenic transplantation of bone marrow-derived rhesus macaque mesenchymal stem cells ameliorates liver fibrosis induced by carbon tetrachloride in mouse

    Directory of Open Access Journals (Sweden)

    Xufeng Fu

    2018-02-01

    Full Text Available Liver fibrosis is a disease that causes high morbidity and has become a major health problem. Liver fibrosis can lead to the end stage of liver diseases (livercirrhosisand hepatocellularcarcinoma. Currently, liver transplantation is the only effective treatment for end-stage liver disease. However, the shortage of organ donors, high cost of medical surgery, immunological rejection and transplantation complications severely hamper liver transplantation therapy. Mesenchymal stem cells (MSCs have been regarded as promising cells for clinical applications in stem cell therapy in the treatment of liver diseases due to their unique multipotent differentiation capacity, immunoregulation and paracrine effects. Although liver fibrosis improvements by MSC transplantation in preclinical experiments as well as clinical trials have been reported, the in vivo fate of MSCs after transportation and their therapeutic mechanisms remain unclear. In this present study, we isolated MSCs from the bone marrow of rhesus macaques. The cells exhibited typical MSC markers and could differentiate into chondrocytes, osteocytes, and adipocytes, which were not affected by labeling with enhanced green fluorescent protein (EGFP. The harvested MSCs respond to interferon-γ stimulation and have the ability to inhibit lymphocyte proliferation in vitro. EGFP-labeled MSCs (1 × 106 cells were transplanted into mice with carbon tetrachloride-induced liver fibrosis via tail vein injection. The ability of the heterogenic MSC infusion to ameliorate liver fibrosis in mice was evaluated by a blood plasma chemistry index, pathological examination and liver fibrosis-associated gene expression. Additionally, a small number of MSCs that homed and engrafted in the mouse liver tissues were evaluated by immunofluorescence analysis. Our results showed that the transplantation of heterogenic MSCs derived from monkey bone marrow can be used to treat liver fibrosis in the mouse model and that the

  8. Cancer chemoprevention by ginseng in mouse liver and other organs.

    Science.gov (United States)

    Nishino, H; Tokuda, H; Ii, T; Takemura, M; Kuchide, M; Kanazawa, M; Mou, X Y; Bu, P; Takayasu, J; Onozuka, M; Masuda, M; Satomi, Y; Konoshima, T; Kishi, N; Baba, M; Okada, Y; Okuyama, T

    2001-01-01

    Oral administration of red ginseng extracts (1% in diet for 40 weeks) resulted in the significant suppression of spontaneous liver tumor formation in C3H/He male mice. Average number of tumors per mouse in control group was 1.06, while that in red ginseng extracts-treated group was 0.33 (p<0.05). Incidence of liver tumor development was also lower in red ginseng extracts-treated group, although the difference from control group was not statistically significant. Anti-carcinogenic activity of white ginseng extracts, besides red ginseng extracts, was also investigated. In the present study, the administration of white ginseng extracts was proven to suppress tumor promoter-induced phenomena in vitro and in vivo. It is of interest that oral administration of the extracts of Ren-Shen-Yang- Rong-Tang, a white ginseng-containing Chinese medicinal prescription, resulted in the suppression of skin tumor promotion by 12-o-tetradecanoylphorbol-13-acetate in 7,12-dimethylbenz[a]anthracene-initiated CD-1 mice. These results suggest the usefulness of ginseng in the field of cancer prevention. PMID:11748379

  9. Comparison of trapping profiles between d-peptides and glutathione in the identification of reactive metabolites

    Directory of Open Access Journals (Sweden)

    Jaana E. Laine

    2015-01-01

    Full Text Available Qualitative trapping profile of reactive metabolites arising from six structurally different compounds was tested with three different d-peptide isomers (Peptide 1, gly–tyr–pro–cys–pro–his-pro; Peptide 2, gly–tyr–pro–ala–pro–his–pro; Peptide 3, gly–tyr–arg–pro–cys–pro–his–lys–pro and glutathione (GSH using mouse and human liver microsomes as the biocatalyst. The test compounds were classified either as clinically “safe” (amlodipine, caffeine, ibuprofen, or clinically as “risky” (clozapine, nimesulide, ticlopidine; i.e., associated with severe clinical toxicity outcomes. Our working hypothesis was as follows: could the use of short different amino acid sequence containing d-peptides in adduct detection confer any add-on value to that obtained with GSH? All “risky” agents’ resulted in the formation of several GSH adducts in the incubation mixture and with at least one peptide adduct with both microsomal preparations. Amlodipine did not form any adducts with any of the trapping agents. No GSH and peptide 2 and 3 adducts were found with caffeine, but with peptide 1 one adduct with human liver microsomes was detected. Ibuprofen produced one Peptide 1-adduct with human and mouse liver microsomes but not with GSH. In conclusion, GSH still remains the gold trapping standard for reactive metabolites. However, targeted d-peptides could provide additional information about protein binding potential of electrophilic agents, but their clinical significance needs to be clarified using a wider spectrum of chemicals together with other safety estimates.

  10. SUPRESSION OF MICROSOMAL OXIDATION WEAKENS HISTOCHROME’S DIURETIC EFFECT AT RATS

    Directory of Open Access Journals (Sweden)

    O. S. Talalaeva

    2013-01-01

    Full Text Available Histochrome is the medicinal form of echinochrome (2, 3, 5, 6, 8-pentahydroxy-7-ethyl-1,4-naphthoquinone. Arisen during clinical application of the drug questions concerning its biotransformation have predetermined the aim of this research: to study participation liver monooxygenase system in maintenance of histochrome’s pharmacological activity.Simple and informative method of the lifetime control of liver monooxygenase systems influence on a metabolism of a medical product is the estimation of changes of pharmacological effect of a r esearched preparation on a background microsomal oxidations i nhibitor. In experiments on rats chloramphenicol action on diuretic effect of histochrome, as the most convenient for screening, was i nvestigated.To control group of animals during 10 days were hypodermically entered by histochrome in a doze of 10 mg/kg (n = 15. Experimental animals preliminary oral received 50 mg/kg of chloramphenicol before three hours of histochrome introduction (n = 16. In both groups of animals measured volume daily excretion of water, creathinin, sodium and potassium ions excretions in experimental rats each two days. The initial level of parameters of excretory kidneys functions were estimated before introduction of preparations at animals.Long-term histochrome’s injection was followed by a fivefold increasing of water excretion and simultaneously creathinin growth one. Allocation of ions of sodium was statistically significantly increased by 11-th day of experiment, and potassium ions – since the ninth day of histochrome injection. In conditions preliminary chloramphenicol applications volume daily daily urine output and creathinin excretion were essentially less control parameters. Allocation with urine of ions of sodium was decreased almost twice in comparison with the values, fixed at introduction histochrome. Excretion potassium ions ware corresponded to an initial level during all period of supervision.Taking into

  11. The comparison of lipid profiling in mouse brain and liver after starvation and a high-fat diet: A medical systems biology approach

    NARCIS (Netherlands)

    Ginneken, V.J.T. van; Verheij, E.; Hekman, M.; Greef, J. van der; Feskens, E.J.M.; Poelmann, R.E.

    2011-01-01

    We investigated with LC-MS techniques, measuring approximately 109 lipid compounds, in mouse brain and liver tissue after 48 hours of starvation and a High-Fat Diet if brain and liver lipid composition changed. We measured Cholesterolesters (ChE), Lysophosphatidyl-cholines (LPC), Phosphatidylcholine

  12. Metabolism of styrene in the human liver in vitro: interindividual variation and enantioselectivity

    NARCIS (Netherlands)

    Wenker, M. A.; Kezić, S.; Monster, A. C.; de Wolff, F. A.

    2001-01-01

    1. The interindividual variation and enantioselectivity of the in vitro styrene oxidation by cytochrome P450 have been investigated in 20 human microsomal liver samples. Liver samples were genotyped for the CYP2E1*6 and CYP2E1*5B alleles. 2. Kinetic analysis indicated the presence of at least two

  13. Distribution of sterol carrier protein2 (SCP2) in rat tissues and evidence for slow turnover in liver and adrenal cortex

    International Nuclear Information System (INIS)

    Kharroubi, A.; Chanderbhan, R.; Fiskum, G.; Noland, B.J.; Scallen, T.J.; Vahouny, G.V.

    1986-01-01

    Sterol carrier protein 2 (SCP 2 ) has been implicated in the regulation of the terminal stages of hepatic cholesterol biosynthesis, and in sterol utilization for adrenal steroid hormone and hepatic bile acid synthesis. In the present studies, a highly sensitive radioimmunoassay, using [ 125 I] SCP 2 , has been developed. Highest levels of SCP 2 were found in rat liver with progressively lower levels in intestinal mucosa, adrenal, kidney, lung and testis. SCP 2 levels were low or absent in heart, brain, skeletal muscle and serum. Liver SCP 2 was largely (44%) associated with the microsomal fraction, while in adrenal, 46% was associated with mitochondria, a distribution which is consistent with the proposed roles for SCP 2 in these tissues. Levels of SCP 2 in AS 30D hepatoma cells were only 5% of those in normal liver. In liver there was no indication of diurnal rhythm of SCP 2 in the cytosol and only slight variation of the microsomal SCP 2 levels. Fasting has only slight effects on SCP 2 concentration of rat liver microsomes and cytosol. Neither ACTH nor cycloheximide treatment of rats had a significant effect on SCP 2 distribution in the adrenal. In general, these findings indicate that SCP 2 has a low turn-over rate

  14. Dipeptidyl peptidase-4 greatly contributes to the hydrolysis of vildagliptin in human liver.

    Science.gov (United States)

    Asakura, Mitsutoshi; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

    2015-04-01

    The major metabolic pathway of vildagliptin in mice, rats, dogs, and humans is hydrolysis at the cyano group to produce a carboxylic acid metabolite M20.7 (LAY151), whereas the major metabolic enzyme of vildagliptin has not been identified. In the present study, we determined the contribution rate of dipeptidyl peptidase-4 (DPP-4) to the hydrolysis of vildagliptin in the liver. We performed hydrolysis assay of the cyano group of vildagliptin using mouse, rat, and human liver samples. Additionally, DPP-4 activities in each liver sample were assessed by DPP-4 activity assay using the synthetic substrate H-glycyl-prolyl-7-amino-4-methylcoumarin (Gly-Pro-AMC). M20.7 formation rates in liver microsomes were higher than those in liver cytosol. M20.7 formation rate was significantly positively correlated with the DPP-4 activity using Gly-Pro-AMC in liver samples (r = 0.917, P vildagliptin hydrolysis in the liver. Additionally, we established stable single expression systems of human DPP-4 and its R623Q mutant, which is the nonsynonymous single-nucleotide polymorphism of human DPP-4, in human embryonic kidney 293 (HEK293) cells to investigate the effect of R623Q mutant on vildagliptin-hydrolyzing activity. M20.7 formation rate in HEK293 cells expressing human DPP-4 was significantly higher than that in control HEK293 cells. Interestingly, R623Q mutation resulted in a decrease of the vildagliptin-hydrolyzing activity. Our findings might be useful for the prediction of interindividual variability in vildagliptin pharmacokinetics. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  15. Irreversible binding of 14C-labelled trichloroethylene to mice liver constituents in vivo and in vitro

    International Nuclear Information System (INIS)

    Uehleke, H.; Poplawski-Tabarelli, S.

    1977-01-01

    1) 14 C-labelled trichloroethylene was injected i.p. into male mice (10 μmole/g of b.w.). The radioactivity irreversibly bound to hepatic protein reached highest levels after 6 h : 2 nmole/mg in cytosol protein, 4.4 nmole/mg in mitochondrial protein, and 7.6 nmole/mg in microsomal protein. 2) The commercial trichloroethylene contained radioactive impurities binding to proteins without metabolic activation. Purification by various extraction removed 60-70% of those materials. In aerobic incubates of mice hepatic microsomes and NADPH the covalent binding rate of the purified trichloroethylene was 1.4 nmole/mg protein in 60 min. The activity of rat liver microsomes was approximately 40% less. Covalent binding increased 2-fold with microsomes of mice pretreated with phenobarbital. (orig.) [de

  16. Application of chimeric mice with humanized liver for study of human-specific drug metabolism.

    Science.gov (United States)

    Bateman, Thomas J; Reddy, Vijay G B; Kakuni, Masakazu; Morikawa, Yoshio; Kumar, Sanjeev

    2014-06-01

    Human-specific or disproportionately abundant human metabolites of drug candidates that are not adequately formed and qualified in preclinical safety assessment species pose an important drug development challenge. Furthermore, the overall metabolic profile of drug candidates in humans is an important determinant of their drug-drug interaction susceptibility. These risks can be effectively assessed and/or mitigated if human metabolic profile of the drug candidate could reliably be determined in early development. However, currently available in vitro human models (e.g., liver microsomes, hepatocytes) are often inadequate in this regard. Furthermore, the conduct of definitive radiolabeled human ADME studies is an expensive and time-consuming endeavor that is more suited for later in development when the risk of failure has been reduced. We evaluated a recently developed chimeric mouse model with humanized liver on uPA/SCID background for its ability to predict human disposition of four model drugs (lamotrigine, diclofenac, MRK-A, and propafenone) that are known to exhibit human-specific metabolism. The results from these studies demonstrate that chimeric mice were able to reproduce the human-specific metabolite profile for lamotrigine, diclofenac, and MRK-A. In the case of propafenone, however, the human-specific metabolism was not detected as a predominant pathway, and the metabolite profiles in native and humanized mice were similar; this was attributed to the presence of residual highly active propafenone-metabolizing mouse enzymes in chimeric mice. Overall, the data indicate that the chimeric mice with humanized liver have the potential to be a useful tool for the prediction of human-specific metabolism of xenobiotics and warrant further investigation.

  17. Time-dependent inhibition of CYP3A4 by gallic acid in human liver microsomes and recombinant systems.

    Science.gov (United States)

    Pu, Qiang-Hong; Shi, Liang; Yu, Chao

    2015-03-01

    1.Gallic acid is a main polyphenol in various fruits and plants. Inhibitory characteristics of gallic acid on CYP3A4 were still unclear. The objective of this work is hence to investigate inhibitory characteristics of gallic acid on CYP3A4 using testosterone as the probe substrate in human liver microsomes (HLMs) and recombinant CYP3A4 (rCYP3A4) systems. 2.Gallic acid caused concentration-dependent loss of CYP3A4 activity with IC50 values of 615.2 μM and 669.5 μM in HLM and rCYP3A4 systems, respectively. IC50-shift experiments showed that pre-incubation with gallic acid in the absence of NADPH contributed to 12- or 14-fold reduction of IC50 in HLM and rCYP3A4 systems, respectively, supporting a time-dependent inhibition. In HLM, time-dependent inactivation variables KI and Kinact were 485.8 μM and 0.05 min(-1), respectively. 3.Compared with the presence of NADPH, pre-incubation of gallic acid in the absence of NADPH markedly increased its inhibitory effects in HLM and rCYP3A4 systems. Those results indicate that CYP3A4 inactivation by gallic acid was independent on NADPH and was mainly mediated its oxidative products. 4.In conclusion, we showed that gallic acid weakly and time-dependently inactivated CYP3A4 via its oxidative products.

  18. Selective inhibition of CYP2C8 by fisetin and its methylated metabolite, geraldol, in human liver microsomes.

    Science.gov (United States)

    Shrestha, Riya; Kim, Ju-Hyun; Nam, Wongshik; Lee, Hye Suk; Lee, Jae-Mok; Lee, Sangkyu

    2018-04-01

    Fisetin is a flavonol compound commonly found in edible vegetables and fruits. It has anti-tumor, antioxidant, and anti-inflammatory effects. Geraldol, the O-methyl metabolite of fisetin in mice, is reported to suppress endothelial cell migration and proliferation. Although the in vivo and in vitro effects of fisetin and its metabolites are frequently reported, studies on herb-drug interactions have not yet been performed. This study was designed to investigate the inhibitory effect of fisetin and geraldol on eight isoforms of human cytochrome P450 (CYP) by using cocktail assay and LC-MS/MS analysis. The selective inhibition of CYP2C8-catalyzed paclitaxel hydroxylation by fisetin and geraldol were confirmed in pooled human liver microsomes (HLMs). In addition, an IC 50 shift assay under different pre-incubation conditions confirmed that fisetin and geraldol shows a reversible concentration-dependent, but not mechanism-based, inhibition of CYP2C8. Moreover, Michaelis-Menten, Lineweaver-burk plots, Dixon and Eadie-Hofstee showed a non-competitive inhibition mode with an equilibrium dissociation constant of 4.1 μM for fisetin and 11.5 μM for geraldol, determined from secondary plot of the Lineweaver-Burk plot. In conclusion, our results indicate that fisetin showed selective reversible and non-competitive inhibition of CYP2C8 more than its main metabolite, geraldol, in HLMs. Copyright © 2018 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  19. Development of Short-term Molecular Thresholds to Predict Long-term Mouse Liver Tumor Outcomes: Phthalate Case Study

    Science.gov (United States)

    Short-term molecular profiles are a central component of strategies to model health effects of environmental chemicals. In this study, a 7 day mouse assay was used to evaluate transcriptomic and proliferative responses in the liver for a hepatocarcinogenic phthalate, di (2-ethylh...

  20. PPARα activation differently affects microparticle content in atherosclerotic lesions and liver of a mouse model of atherosclerosis and NASH.

    Science.gov (United States)

    Baron, Morgane; Leroyer, Aurélie S; Majd, Zouher; Lalloyer, Fanny; Vallez, Emmanuelle; Bantubungi, Kadiombo; Chinetti-Gbaguidi, Giulia; Delerive, Philippe; Boulanger, Chantal M; Staels, Bart; Tailleux, Anne

    2011-09-01

    Atherosclerosis and non-alcoholic fatty liver disease (NAFLD) are complex pathologies characterized by lipid accumulation, chronic inflammation and extensive tissue remodelling. Microparticles (MPs), small membrane vesicles produced by activated and apoptotic cells, might not only be biomarkers, but also functional actors in these pathologies. The apoE2-KI mouse is a model of atherosclerosis and NAFLD. Activation of the nuclear receptor PPARα decreases atherosclerosis and components of non-alcoholic steatohepatitis (NASH) in the apoE2-KI mouse. (1) To determine whether MPs are present in atherosclerotic lesions, liver and plasma during atherosclerosis and NASH progression in apoE2-KI mice, and (2) to study whether PPARα activation modulates MP concentrations. ApoE2-KI mice were fed a Western diet to induce atherosclerosis and NASH. MPs were isolated from atherosclerotic lesions, liver and blood and quantified by flow cytometry. An increase of MPs was observed in the atherosclerotic lesions and in the liver of apoE2-KI mice upon Western diet feeding. PPARα activation with fenofibrate decreased MP levels in the atherosclerotic lesions in a PPARα-dependent manner, but did not influence MP concentrations in the liver. Here we report that MPs are present in atherosclerotic lesions and in the liver of apoE2-KI mice. Their concentration increased during atherosclerosis and NASH development. PPARα activation differentially modulates MP levels in a tissue-specific manner. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Immunologic analyses of mouse cystathionase in normal and leukemic cells

    International Nuclear Information System (INIS)

    Bikel, I.; Faibes, D.; Uren, J.R.; Livingston, D.M.

    1978-01-01

    Rabbit antisera have been raised against mouse liver cystathionase and shown to possess enzyme neutralizing activity. Agar gel double immunodiffusion analyses demonstrated that both mouse liver cystathionase and rat liver cystathionase react with the antisera, the latter enzyme being completely cross-reactive with the former. Following radioiodination of the purified rat liver enzyme, a double antibody radioimmunoassay was developed in which greater than 90% of the labeled protein could be specifically precipitated with the anti-mouse cystathionase antibodies. In this test the purified rat liver and mouse liver enzymes were virtually indistinguishable, generating superimposable competition displacement curves on a protein mass basis. These results indicate that both enzymes are immunologically identical, thus validating the use of the rat in lieu of the murine liver enzyme as radiolabeled tracer in an assay for mouse cystathionase. In addition, competition radioimmunoassays demonstrated that the immunological reactivities of both the purified rat liver and mouse liver enzymes were equally heat sensitive. The sensitivity of the assay was determined to be 1 ng of enzyme protein/0.22 mL of assay mixture, and the assay could be used to detect the presence of enzyme protein in tissue homogenates of single mouse organs. Mouse or rat cross-reactivity with human liver cystathionase was incomplete; but, with the exception of heart and spleen, parallel radioimmunoassay competition displacement curves were obtained for cystathionase from different mouse organs including thymus. Extracts of 7-, 9-, and 10-month-old spontaneous AKR mouse thymomas were tested in the radioimmunoassay along with extracts of age-matched thymuses which were grossly tumor free. A reaction of nonidentity was observed for all of the tumor extracts while a reaction identical with that of the pure liver enzyme was found with all of the normal thymus extracts

  2. Ectopic expression of the calcium-binding protein parvalbumin in mouse liver endothelial cells

    DEFF Research Database (Denmark)

    Castillo, M B; Berchtold, M W; Rülicke, T

    1997-01-01

    To elucidate the physiological role of the Ca2+ binding protein parvalbumin, we have generated transgenic mice carrying the full-length complementary DNA (cDNA) of rat parvalbumin under the control of the heavy-metal inducible metallothionein IIA promoter. Immunohistochemical and biochemical...... methods have been used to detect the presence of ectopic parvalbumin expression in different tissues. Here we show the expression of parvalbumin in endothelial cells lining the liver sinusoids in situ and after isolation in vitro. The hemodynamic effects of endothelin 1, a peptide hormone mediating potent...... vasoconstriction via calcium signalling, were investigated in the mouse liver perfused in situ. Vasoconstriction, thought to be mediated by the Ito cell, was not affected in the transgenic animals, whereas microvascular exchange, probed with the multiple indicator dilution technique, was markedly decreased...

  3. Cholesterol esterification by mouse liver homogenate. Contribution to the study of ACYL-CoA: Cholesterol ACYL transferase in mammalian liver

    International Nuclear Information System (INIS)

    Soares, M.G.C.B.

    1976-01-01

    A cholesterol- esterifying enzyme from mouse liver has been partially characterized. The enzyme which showed optimum activity at pH 7,1 and required ATP and CoA, was identified as an acyl CoA: cholesterol acyl transferase (E.C.2.3.1.26). As a fuction of time the percentage of esterified cholesterol increased linearly during the first hour of incubation and continued to increase but not linearly with 4 hours, after which time no further net esterefication was observed. The relative concentration of esterified cholesterol remained constant between the fourth and twelveth hours of incubation but afterwards decreased when the incubation continued until 24 hours. The cholesterol- esterifying activity was 24,0+- 2,9 nmoles cholesterol esterified per gram tissue wet weight per minute. The mean percentages of free cholesterol esterified in and 24 hours respectively were 14,8+- 1,6 e 21,9+- 4,5. The subfractionation of labelled cholesteryl esters after one hour incubation of liver homogenate with 4-C 14 -Cholesterol showed the order of preference for the formation of the different ester classes to be monounsatured > diunsatured ≥ saturated >> polyunsaturated. The properties of the enzyme frommouse liver do not markedly differ from those of the previously recorded ACAT activity of rat liver. (Author) [pt

  4. Detection on immunoblot of new proteins from the soluble fraction of the cell recognized either by anti-liver-kidney microsome antibodies type 1 or by anti-liver cytosol antibodies type 1--relationship with hepatitis C virus infection.

    Science.gov (United States)

    Ballot, E; Desbos, A; Monier, J C

    1996-09-01

    Antibodies directed against liver cytosol protein, called anti-liver cytosol type 1 (LC1 Ab), have been described by both immunofluorescence (IF) and immunodiffusion techniques in sera from patients with autoimmune hepatitis (AIH). They have never been found in association with antibodies directed against the hepatitis C virus (HCV), unlike the anti-liver-kidney microsome antibodies type 1 (LKM1 Ab), the serological marker of AIH type 2. This suggests that there are two subgroups of AIH type 2, i.e., HCV-related and non-HCV-related. In this study, immunoblotting experiments were performed using proteins from the soluble phase of the rat liver cell; 141 sera which tested positive for LKM1 Ab by IF, 24 identified as having LC1 Ab by IF, and 50 from blood donors as controls were analyzed. Three bands were stained by LC1 Ab sera more often than by the control sera, and with a statistically significant frequency. These 3 proteins were located at apparent Mr 50,000, 55,000, and 60,000. The LKM1 Ab-positive sera as defined by IF stained six bands with a statistically significant frequency compared to the controls. Their apparent Mr were 35,000, 39,000, 47,000, 50,000, 55,000, and 60,000. LKM1 Ab-positive sera which were anti-HCV negative recognized a 60,000 protein belonging to the soluble phase of the cell, with a statistically significant frequency compared to LKM1 Ab-positive sera which were anti-HCV positive. This 60,000 protein was also recognized by LC1 Ab-positive sera, which were almost always anti-HCV negative. The presence of antibodies against a 60,000 protein from the soluble phase of the cell is discussed in terms of the anti-HCV serological markers found in the sera from patients with AIH.

  5. Microsomal receptor for steroid hormones: functional implications for nuclear activity.

    Science.gov (United States)

    Muldoon, T G; Watson, G H; Evans, A C; Steinsapir, J

    1988-01-01

    Target tissues for steroid hormones are responsive by virtue of and to the extent of their content of functional intracellular receptors. Recent years have seen a shift in considerations of the cellular dynamics and distribution of these receptors, with current views favoring predominant intranuclear localization in the intact cell. This paper summarizes our analyses of the microsomal estrogen and androgen binding capability of rat uterine and ventral prostate tissue, respectively; these studies have revealed a set of high affinity sites that may act as a conduit for estrogen traversing the cell en route to the nucleus. These sites have many properties in common with cytosolic receptors, with the salient difference of a failure to activate to a more avid DNA-binding form under conditions which permit such activation of cytosolic receptors. The microsomal estrogen-binding proteins also have appreciable affinity for progesterone, another distinction from other known cellular estrogen receptor species. Various experimental approaches were employed to demonstrate that the microsomal receptors were not simply cytosol contaminants; the most convincing evidence is the recent successful separation of the cytosolic and microsomal forms by differential ammonium sulfate precipitation. Discrete subfractionation of subcellular components on successive sucrose gradients, with simultaneous assessments of binding capability and marker enzyme concentrations, indicates that the major portion of the binding is localized within the vesicles of the endoplasmic reticulum free of significant plasma membrane contamination. The microsomal receptors are readily solubilized by extraction with high- or low-salt-containing buffers or with steroid. The residual microsomes following such extraction have the characteristics of saturable acceptor sites for cytosolic estrogen-receptor complexes. The extent to which these sites will accept the cytosolic complexes is equal to the concentration of

  6. Identification of UGT2B9*2 and UGT2B33 isolated from female rhesus monkey liver.

    Science.gov (United States)

    Dean, Brian; Arison, Byron; Chang, Steve; Thomas, Paul E; King, Christopher

    2004-06-01

    Two UDP-glucuronosyltransferases (UGT2B9(*)2 and UGT2B33) have been isolated from female rhesus monkey liver. Microsomal preparations of the cell lines expressing the UGTs catalyzed the glucuronidation of the general substrate 7-hydroxy-4-(trifluoromethyl)coumarin in addition to selected estrogens (beta-estradiol and estriol) and opioids (morphine, naloxone, and naltrexone). UGT2B9(*)2 displayed highest efficiency for beta-estradiol-17-glucuronide production and did not catalyze the glucuronidation of naltrexone. UGT2B33 displayed highest efficiency for estriol and did not catalyze the glucuronidation of beta-estradiol. UGT2B9(*)2 was found also to catalyze the glucuronidation of 4-hydroxyestrone, 16-epiestriol, and hyodeoxycholic acid, while UGT2B33 was capable of conjugating 4-hydroxyestrone, androsterone, diclofenac, and hyodeoxycholic acid. Three glucocorticoids (cortisone, cortisol, and corticosterone) were not substrates for glucuronidation by liver or kidney microsomes or any expressed UGTs. Our current data suggest the use of beta-estradiol-3-glucuronidation, beta-estradiol-17-glucuronidation, and estriol-17-glucuronidation to assay UGT1A01, UGT2B9(*)2, and UGT2B33 activity in rhesus liver microsomes, respectively.

  7. Influence of Chloramphenicol and Amoxicillin on Rat Liver ...

    African Journals Online (AJOL)

    This study examined the effect of chloramphenicol and amoxicillin on liver microsomal enzymes Ca2+-ATPase and Glucose-6-Phosphatase (G-6-P) and lipid peroxidation in rats. Male Wistar strain rats weighing 120 – 195 g were divided into four groups. Group one, the control group, received physiological saline, group ...

  8. Immunological cross-reactivity to multiple autoantigens in patients with liver kidney microsomal type 1 autoimmune hepatitis.

    Science.gov (United States)

    Choudhuri, K; Gregorio, G V; Mieli-Vergani, G; Vergani, D

    1998-11-01

    We describe two patients with liver kidney microsomal antibody type 1 (LKM1)-positive autoimmune hepatitis (AIH) with associated endocrinopathies. The first patient had insulin-dependent diabetes (IDDM), and the second patient had Addison's disease and hypoparathyroidism, and is also positive for islet cell antibodies, without overt diabetes. To account for the existence of multiple endocrinopathy in these patients, we investigated whether there is sequence similarity between the target of LKM1 antibodies, cytochrome P4502D6 (CYP2D6), and other human proteins, and if so, whether this structural similarity produces a detectable cross-reactive immune response. Our database search identified two proteins, carboxypeptidase H, an autoantigen in insulin-dependent diabetes, and 21-hydroxylase, the major autoantigen in Addison's disease, that share sequence similarity to the second major LKM1 epitope on CYP2D6. We tested the reactivity of sera from these patients to the homologous regions of the three autoantigens using an enzyme-linked immunosorbent assay (ELISA). The cut-off for positivity was established by testing sera from 22 healthy children. To determine the significance of reactivity to the peptide homologues of the three autoantigens, we investigated 16 additional patients with LKM1 AIH and 20 children with chronic hepatitis B virus infection as pathological controls. We found that reactivity to the second major epitope of CYP2D6 is significantly associated with reactivity to the homologous regions of carboxypeptidase H (CPH) and 21-hydroxylase (21-OHase) in patients with LKM1 AIH, and that this simultaneous recognition is cross-reactive. We suggest that a cross-reactive immune response between homologous autoantigens may contribute to the development of multiple endocrinopathies in LKM1 AIH.

  9. The effect of ghee (clarified butter) on serum lipid levels and microsomal lipid peroxidation.

    Science.gov (United States)

    Sharma, Hari; Zhang, Xiaoying; Dwivedi, Chandradhar

    2010-04-01

    Ghee, also known as clarified butter, has been utilized for thousands of years in Ayurveda as a therapeutic agent. In ancient India, ghee was the preferred cooking oil. In the last several decades, ghee has been implicated in the increased prevalence of coronary artery disease (CAD) in Asian Indians due to its content of saturated fatty acids and cholesterol and, in heated ghee, cholesterol oxidation products. Our previous research on Sprague-Dawley outbred rats, which serve as a model for the general population, showed no effect of 5 and 10% ghee-supplemented diets on serum cholesterol and triglycerides. However, in Fischer inbred rats, which serve as a model for genetic predisposition to diseases, results of our previous research showed an increase in serum total cholesterol and triglyceride levels when fed a 10% ghee-supplemented diet. In the present study, we investigated the effect of 10% dietary ghee on microsomal lipid peroxidation, as well as serum lipid levels in Fischer inbred rats to assess the effect of ghee on free radical mediated processes that are implicated in many chronic diseases including cardiovascular disease. Results showed that 10% dietary ghee fed for 4 weeks did not have any significant effect on levels of serum total cholesterol, but did increase triglyceride levels in Fischer inbred rats. Ghee at a level of 10% in the diet did not increase liver microsomal lipid peroxidation or liver microsomal lipid peroxide levels. Animal studies have demonstrated many beneficial effects of ghee, including dose-dependent decreases in serum total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides; decreased liver total cholesterol, triglycerides, and cholesterol esters; and a lower level of nonenzymatic-induced lipid peroxidation in liver homogenate. Similar results were seen with heated (oxidized) ghee which contains cholesterol oxidation products. A preliminary clinical study showed that high doses of

  10. Modulation of catechol estrogen synthesis by rat liver microsomes: effects of treatment with growth hormone or testosterone

    International Nuclear Information System (INIS)

    Quail, J.A.; Jellinck, P.H.

    1987-01-01

    The ability of GH from various mammalian species, administered to normal mature male rats by constant infusion, to decrease the hepatic 2-hydroxylation of estradiol (E2) to female levels, as measured by the release of 3 H 2 O from [2-3H]E2, was determined. Rat and human GH (hGH) showed the highest activity while ovine GH was inactive. PRL (0.6 IU/h X kg) administered together with hGH (0.02 IU/h X kg) did not antagonize the feminizing action of GH. Infusion of hGH into male rats decreased the affinity of estradiol 2-hydroxylase for its steroid substrate and altered the linear Lineweaver-Burk plot towards a nonlinear hyperbolic plot characteristic of the female. The apparent Michaelis-Menten constant (Km) for the reaction was 1.69 microM for males and 2.75 microM for testosterone-treated ovariectomized females. An equal mixture of liver microsomes from male and female rats gave kinetic values similar to those observed with males alone. Neonatal imprinting with androgen did not alter the magnitude of the response of female rats to treatment with testosterone and/or GH at maturity and the androgen effect could only be shown in ovariectomized animals. The results with rats of different endocrine status were corroborated by the kinetic data and by the pattern of metabolites obtained with [4- 14 C]E2 when examined by TLC and autoradiography. The hormonal control of estradiol 2-hydroxylase, the key enzyme in catechol estrogen formation, and the contribution of sex-specific multiple forms of the enzyme to this reaction are discussed

  11. Oxidative metabolism of monensin in rat liver microsomes and interactions with tiamulin and other chemotherapeutic agents: evidence for the involvement of cytochrome P-450 3A subfamily.

    Science.gov (United States)

    Nebbia, C; Ceppa, L; Dacasto, M; Carletti, M; Nachtmann, C

    1999-09-01

    Monensin (MON) is an ionophore antibiotic widely used in veterinary practice as a coccidiostatic or a growth promoter. The aims of this study were to characterize the P-450 isoenzyme(s) involved in the biotransformation of the ionophore and to investigate how this process may be affected by tiamulin and other chemotherapeutic agents known to produce toxic interactions with MON when administered concurrently in vivo. In liver microsomes from untreated rats (UT) or from rats pretreated, respectively, with ethanol (ETOH), beta-naphthoflavone (betaNAF), phenobarbital (PB), pregnenolone 16alpha-carbonitrile (PCN), or dexamethasone (DEX), the rate of MON O-demethylation was the following: DEX > PCN > PB > UT = ETOH > betaNAF; similar results were obtained by measuring total MON metabolism. In addition, the extent of triacetyloleandomycin-mediated P-450 complexes was greatly reduced by the prior addition of 100 microM MON. In DEX-treated microsomes, MON O-demethylation was found to fit monophasic Michaelis-Menten kinetics (K(M) = 67.6 +/- 0.01 microM; V(max) = 4.75 +/- 0.76 nmol/min/mg protein). Tiamulin markedly inhibited this activity in an apparent competitive manner, with a calculated K(i) (Dixon plot) of 8.2 microM and an IC(50) of about 25 microM. At the latter concentration, only ketoconazole or metyrapone, which can bind P-450 3A, inhibited MON O-demethylase to a greater extent than tiamulin, whereas alpha-naphthoflavone, chloramphenicol, or sulphametasine was less effective. These results suggest that P-450 3A plays an important role in the oxidative metabolism of MON and that compounds capable of binding or inhibiting this isoenzyme could be expected to give rise to toxic interactions with the ionophore.

  12. Time-course comparison of xenobiotic activators of CAR and PPARα in mouse liver

    International Nuclear Information System (INIS)

    Ross, Pamela K.; Woods, Courtney G.; Bradford, Blair U.; Kosyk, Oksana; Gatti, Daniel M.; Cunningham, Michael L.; Rusyn, Ivan

    2009-01-01

    Constitutive androstane receptor (CAR) and peroxisome proliferator activated receptor (PPAR)α are transcription factors known to be primary mediators of liver effects, including carcinogenesis, by phenobarbital-like compounds and peroxisome proliferators, respectively, in rodents. Many similarities exist in the phenotypes elicited by these two classes of agents in rodent liver, and we hypothesized that the initial transcriptional responses to the xenobiotic activators of CAR and PPARα will exhibit distinct patterns, but at later time-points these biological pathways will converge. In order to capture the global transcriptional changes that result from activation of these nuclear receptors over a time-course in the mouse liver, microarray technology was used. First, differences in basal expression of liver genes between C57Bl/6J wild-type and Car-null mice were examined and 14 significantly differentially expressed genes were identified. Next, mice were treated with phenobarbital (100 mg/kg by gavage for 24 h, or 0.085% w/w diet for 7 or 28 days), and liver gene expression changes with regards to both time and treatment were identified. While several pathways related to cellular proliferation and metabolism were affected by phenobarbital in wild-type mice, no significant changes in gene expression were found over time in the Car-nulls. Next, we determined commonalities and differences in the temporal response to phenobarbital and WY-14,643, a prototypical activator of PPAR α. Gene expression signatures from livers of wild-type mice C57Bl6/J mice treated with PB or WY-14,643 were compared. Similar pathways were affected by both compounds; however, considerable time-related differences were present. This study establishes common gene expression fingerprints of exposure to activators of CAR and PPARα in rodent liver and demonstrates that despite similar phenotypic changes, molecular pathways differ between classes of chemical carcinogens

  13. Metabolomics (liver and blood profiling) in a mouse model in response to fasting: A study of hepatic steatosis

    NARCIS (Netherlands)

    Ginneken, V. van; Verhey, E.; Poelmann, R.; Ramakers, R.; Dijk, K.W. van; Ham, L.; Voshol, P.; Havekes, L.; Eck, M. van; Greef, J. van der

    2007-01-01

    A metabolomic approach was applied to a mouse model of starvation-induced hepatic steatosis. After 24 h of fasting it appears that starvation reduced the phospholipids (PL), free cholesterol (FC), and cholesterol esters (CE) content of low-density lipoproteins (LDL). In liver lipid profiles major

  14. Oxidative metabolism of BDE-47, BDE-99, and HBCDs by cat liver microsomes: Implications of cats as sentinel species to monitor human exposure to environmental pollutants.

    Science.gov (United States)

    Zheng, Xiaobo; Erratico, Claudio; Luo, Xiaojun; Mai, Bixian; Covaci, Adrian

    2016-05-01

    The in vitro oxidative metabolism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), and individual α-, β- and γ-hexabromocyclododecane (HBCD) isomers catalyzed by cytochrome P450 (CYP) enzymes was screened using cat liver microsomes (CLMs). Six hydroxylated metabolites, namely 4-hydroxy-2,2',3,4'-tetrabromodiphenyl ether (4-OH-BDE-42), 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47), 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE-47), 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47), 4'-hydroxy-2,2',4,5'- tetrabromodiphenyl ether (4'-OH-BDE-49), and 2'-hydroxy-2,3',4,4'-tetrabromodiphenyl ether (2'-OH-BDE-66), were identified and quantified after incubation of BDE-47. A di-OH-tetra-BDE was also found as metabolite of BDE-47 with CLMs. 5-OH-BDE-47 was the major metabolite formed. Five hydroxylated metabolites (3'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (3'-OH-BDE-99), 5'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99), 6-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (6-OH-BDE-99), 6'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (6'-OH-BDE-99), and 4'-hydroxy-2,2',4,5,5'-pentabromodiphenyl ether (4'-OH-BDE-101) were formed from BDE-99 incubated with CLMs. Concentrations of BDE-99 metabolites were lower than those of BDE-47. Four or more mono-hydroxylated HBCD (OH-HBCDs), four or more di-hydroxylated HBCD (di-OH-HBCDs), five or more mono-hydroxylated pentabromocyclododecanes (OH-PBCDs), and five or more di-hydroxylated pentabromocyclododecenes (di-OH-PBCDs) were detected after incubation of α-, β-, or γ-HBCD with CLMs. No diastereoisomeric or enantiomeric enzymatic isomerisation was observed incubating α-, β- or γ-HBCD with CLMs. Collectively, our data suggest that (i) BDE-47 is metabolized at a faster rate than BDE-99 by CLMs, (ii) OH-HBCDs are the major hydroxylated metabolites of α-, β- and γ-HBCD produced by CLMs, and (iii) the oxidative metabolism of BDE-47 and

  15. Adenosinetriphosphate content and adenosinetriphosphatase activity in cell fractions of the liver and brain of chick embryos and birds treated with gamma-rays

    International Nuclear Information System (INIS)

    Todorov, B.

    1977-01-01

    Studies are conducted on the level of ADP and the adenosinetriphosphatase in nuclei, mitochondria, and microsomes taken from the brain and liver of singly gamma-irradiated (1000 rd) chick embryos and birds. As a result of the treatment the ADP content dropped, while the activity of ADP rose. These changes were more strongly expressed in the nuclei, than in the mitochondria, and to a lesser extent - in the microsomes. Twelve-day chick embryos showed more markedly expressed radiosensitivity than newly hatched chicks. This embryonal stage is characterized by intense growth, differentiation and metabolic processes in the liver, which substantiate not only the higher radiosensitivity of this age group but the more strongly expressed changes in the liver as compared with the brain. (author)

  16. Proteomic and transcriptomic studies of HBV-associated liver fibrosis of an AAV-HBV-infected mouse model.

    Science.gov (United States)

    Kan, Fangming; Ye, Lei; Yan, Tao; Cao, Jiaqi; Zheng, Jianhua; Li, Wuping

    2017-08-22

    Human hepatitis B virus (HBV) infection is an important public health issue in the Asia-Pacific region and is associated with chronic hepatitis, liver fibrosis, cirrhosis and even liver cancer. However, the underlying mechanisms of HBV-associated liver fibrosis remain incompletely understood. In the present study, proteomic and transcriptomic approaches as well as biological network analyses were performed to investigate the differentially expressed molecular signature and key regulatory networks that were associated with HBV-mediated liver fibrosis. RNA sequencing and 2DE-MALDI-TOF/TOF were performed on liver tissue samples obtained from HBV-infected C57BL/6 mouse generated via AAV8-HBV virus. The results showed that 322 genes and 173 proteins were differentially expressed, and 28 HBV-specific proteins were identified by comprehensive proteomic and transcriptomic analysis. GO analysis indicated that the differentially expressed proteins were predominantly involved in oxidative stress, which plays a key role in HBV-related liver fibrosis. Importantly, CAT, PRDX1, GSTP1, NXN and BLVRB were shown to be associated with oxidative stress among the differentially expressed proteins. The most striking results were validated by Western blot and RT-qPCR. The RIG-I like receptor signaling pathway was found to be the major signal pathway that changed during HBV-related fibrosis. This study provides novel insights into HBV-associated liver fibrosis and reveals the significant role of oxidative stress in liver fibrosis. Furthermore, CAT, BLVRB, NXN, PRDX1, and IDH1 may be candidates for detection of liver fibrosis or therapeutic targets for the treatment of liver fibrosis.

  17. A positive feedback loop between progesterone and microsomal prostaglandin E synthase-1-mediated PGE2 promotes production of both in mouse granulosa cells.

    Science.gov (United States)

    Tamura, Kazuhiro; Naraba, Hiroaki; Hara, Takahiko; Nakamura, Kota; Yoshie, Mikihiro; Kogo, Hiroshi; Tachikawa, Eiichi

    2016-03-01

    Microsomal prostaglandin E synthase-1 (mPGES-1) is primarily expressed in granulosa cells (GCs) in the preovulatory follicle. Both prostaglandin E2 (PGE2) and progesterone (P4) are implicated in various reproductive functions. Here, we demonstrate that mPges-1 may be a direct downstream target gene of the P4 receptor and P4-stimulated PGE2 secretion can stimulate P4 production in a newly generated mouse GC line (GtsT). Treatment of GtsT cells with a P4 receptor agonist, norgestrel, markedly increased mPGES-1 expression detected by RT-PCR analysis. PGE2 secretion measured by an enzyme-linked immunosorbent assay was enhanced by P4 treatment. Luciferase assays revealed that the proximal promoter region of the mPges-1 gene was responsible for the effects of P4 treatment. Conversely, PGE2 treatment stimulated P4 secretion, which coordinated with mRNA expression of steroidogenic acute regulatory protein. Taken together, P4 may regulate mPGES-1 expression to increase PGE2 secretion and in turn P4 production. An autocrine loop between P4 and PGE2 might function to maintain the increased levels of both in GCs. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Effects of whole body x-ray irradiation on induction by phenobarbital of rat liver glucose-6-phosphate dehydrogenase and glutathione reductase

    Energy Technology Data Exchange (ETDEWEB)

    Bitny-Szlachto, S.; Szyszko, A. (Wojskowy Inst. Higieny i Epidemiologii, Warsaw (Poland))

    1979-01-01

    In rats treated with phenobarbital (3x100 mg/kg, i.p.), liver G-6-P dehydrogenase activity increased by 70% in the cytosol and in the 9.000xg supernatant, and only by 20% in microsomes. Moreover, the phenobarbital treatment increased rat liver GSSG reductase activity by 30%. On the other hand, activity of the liver microsomal G-6-P dehydrogenase was found to increase by some 20% in whole body irradiated, both control and phenobarbital treated rats. In rats irradiated with 600 R prior to the first dose of the inducer there was not noted any increase in G-6-P dehydrogenase of the 9.000xg supernatant, and increase in the cytosol activity dropped to 38%. Thus, induction of the soluble liver G-6-P dehydrogenase by phenobarbital has turned out to be radiosensitive, whereas phenobarbital induction of GSSG reductase was unaffected by irradiation.

  19. PEPCK-M expression in mouse liver potentiates, not replaces, PEPCK-C mediated gluconeogenesis

    Science.gov (United States)

    Méndez-Lucas, Andrés; Duarte, João; Sunny, Nishanth E.; Satapati, Santhosh; He, TianTeng; Fu, Xiaorong; Bermúdez, Jordi; Burgess, Shawn C.; Perales, Jose C.

    2013-01-01

    Background & Aims Hepatic gluconeogenesis helps maintain systemic energy homeostasis by compensating for discontinuities in nutrient supply. Liver specific deletion of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) abolishes gluconeogenesis from mitochondrial substrates, deregulates lipid metabolism and affects TCA cycle. While, mouse liver almost exclusively expresses PEPCK-C, humans equally present a mitochondrial isozyme (PEPCK-M). Despite clear relevance to human physiology, the role of PEPCK-M and its gluconeogenic potential remain unknown. Here, we test the significance of PEPCK-M in gluconeogenesis and TCA cycle function in liver-specific PEPCK-C knockout and WT mice. Methods The effects of the overexpression of PEPCK-M were examined by a combination of tracer studies and molecular biology techniques. Partial PEPCK-C re-expression was used as a positive control. Metabolic fluxes were evaluated in isolated livers by NMR using 2H and 13C tracers. Gluconeogenic potential, together with metabolic profiling, were investigated in vivo and in primary hepatocytes. Results PEPCK-M expression partially rescued defects in lipid metabolism, gluconeogenesis and TCA cycle function impaired by PEPCK-C deletion, while ~10% re-expression of PEPCK-C normalized most parameters. When PEPCK-M was expressed in the presence of PEPCK-C, the mitochondrial isozyme amplified total gluconeogenic capacity, suggesting autonomous regulation of oxaloacetate to phosphoenolpyruvate fluxes by the individual isoforms. Conclusions We conclude that PEPCK-M has gluconeogenic potential per se, and cooperates with PEPCK-C to adjust gluconeogenic/TCA flux to changes in substrate or energy availability, hinting at a role in the regulation of glucose and lipid metabolism in human liver. PMID:23466304

  20. Zonation of heme synthesis enzymes in mouse liver and their regulation by β-catenin and Ha-ras.

    Science.gov (United States)

    Braeuning, Albert; Schwarz, Michael

    2010-11-01

    Cytochrome P450 (CYP) hemoproteins play an important role in hepatic biotransformation. Recently, β-catenin and Ha-ras signaling have been identified as players controlling transcription of various CYP genes in mouse liver. The aim of the present study was to analyze the role of β-catenin and Ha-ras in the regulation of heme synthesis. Heme synthesis-related gene expression was analyzed in normal liver, in transgenic mice expressing activated β-catenin or Ha-ras, and in hepatomas. Regulation of the aminolevulinate dehydratase promoter was studied in vitro. Elevated expression of mRNAs and proteins involved in heme biosynthesis was linked to β-catenin activation in perivenous hepatocytes, in transgenic hepatocytes, and in hepatocellular tumors. Stimulation of the aminolevulinate dehydratase promoter by β-catenin was independent of the β-catenin/T-cell-specific transcription factor dimer. By contrast, activation of Ha-ras repressed heme synthesis-related gene expression. The present data suggest that β-catenin enhances the expression of both CYPs and heme synthesis-related genes, thus coordinating the availability of CYP apoprotein and its prosthetic group heme. The reciprocal regulation of heme synthesis by β-catenin and Ha-ras-dependent signaling supports our previous hypothesis that antagonistic action of these pathways plays a major role in the control of zonal gene expression in healthy mouse liver and aberrant expression patterns in hepatocellular tumors.

  1. Nuclear receptor CAR (NR1I3) is essential for DDC-induced liver injury and oval cell proliferation in mouse liver.

    Science.gov (United States)

    Yamazaki, Yuichi; Moore, Rick; Negishi, Masahiko

    2011-11-01

    The liver is endowed with the ability to regenerate hepatocytes in response to injury. When this regeneration ability is impaired during liver injury, oval cells, which are considered to be postnatal hepatic progenitors, proliferate and differentiate into hepatocytes. Here we have demonstrated that 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) activates the nuclear receptor constitutive active/androstane receptor (CAR), resulting in proliferation of oval cells in mouse liver. Activation of CAR by DDC was shown by hepatic nuclear CAR accumulation and cytochrome P450 (CYP)2B10 mRNA induction after feeding a 0.1% DDC-containing diet to Car(+/+) mice. After being fed the DDC diet, Car(+/+), but not Car(-/-) mice, developed severe liver injury and an A6 antibody-stained ductular reaction in an area around the portal tract. Oval cell proliferation was confirmed by laser capture microdissection and real-time PCR; mRNAs for the two oval cell markers epithelial cell adhesion molecule and TROP2 were specifically induced in the periportal region of DDC diet-fed Car(+/+), but not Car(-/-) mice. Although rates of both hepatocyte growth and death were initially enhanced only in DDC diet-fed Car(+/+) mice, growth was attenuated when oval cells proliferated, whereas death continued unabated. DDC-induced liver injury, which differs from other CAR activators such as phenobarbital, occurred in the periportal region where cells developed hypertrophy, accumulated porphyrin crystals and inflammation developed, all in association with the proliferation of oval cells. Thus, CAR provides an excellent experimental model for further investigations into its roles in liver regeneration, as well as the development of diseases such as hepatocellular carcinoma.

  2. Ursodeoxycholic Acid Suppresses Lipogenesis in Mouse Liver: Possible Role of the Decrease in β-Muricholic Acid, a Farnesoid X Receptor Antagonist.

    Science.gov (United States)

    Fujita, Kyosuke; Iguchi, Yusuke; Une, Mizuho; Watanabe, Shiro

    2017-04-01

    The farnesoid X receptor (FXR) is a major nuclear receptor of bile acids; its activation suppresses sterol regulatory element-binding protein 1c (SREBP1c)-mediated lipogenesis and decreases the lipid contents in the liver. There are many reports showing that the administration of ursodeoxycholic acid (UDCA) suppresses lipogenesis and reduces the lipid contents in the liver of experimental animals. Since UDCA is not recognized as an FXR agonist, these effects of UDCA cannot be readily explained by its direct activation of FXR. We observed that the dietary administration of UDCA in mice decreased the expression levels of SREBP1c and its target lipogenic genes. Alpha- and β-muricholic acids (MCA) and cholic acid (CA) were the major bile acids in the mouse liver but their contents decreased upon UDCA administration. The hepatic contents of chenodeoxycholic acid and deoxycholic acid (DCA) were relatively low but were not changed by UDCA. UDCA did not show FXR agonistic or antagonistic potency in in vitro FXR transactivation assay. Taking these together, we deduced that the above-mentioned change in hepatic bile acid composition induced upon UDCA administration might cause the relative increase in the FXR activity in the liver, mainly by the reduction in the content of β-MCA, a farnesoid X receptor antagonist, which suggests a mechanism by which UDCA suppresses lipogenesis and decreases the lipid contents in the mouse liver.

  3. An optimized method for mouse liver sinusoidal endothelial cell isolation

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Jeremy, E-mail: jeremy.meyer@hcuge.ch [Division of Digestive and Transplantation Surgery, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14 (Switzerland); Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Lacotte, Stéphanie, E-mail: stephanie.lacotte@unige.ch [Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Morel, Philippe, E-mail: philippe.morel@hcuge.ch [Division of Digestive and Transplantation Surgery, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14 (Switzerland); Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Gonelle-Gispert, Carmen, E-mail: carmen.gonelle@unige.ch [Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland); Bühler, Léo, E-mail: leo.buhler@hcuge.ch [Division of Digestive and Transplantation Surgery, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Genève 14 (Switzerland); Unit of Surgical Research, University of Geneva, Rue Michel-Servet 1, 1206 Genève (Switzerland)

    2016-12-10

    The objective of the present study was to develop an accurate and reproducible method for liver sinusoidal endothelial cell (LSEC) isolation in mice. Non-parenchymal cells were isolated using a modified two-step collagenase digestion combined with Optiprep density gradient centrifugation. LSEC were further purified using two prevalent methods, short-term selective adherence and CD146+ magnetic-activated cell sorting (MACS), and compared in terms of cell yield, viability and purity to our purification technique using CD11b cell depletion combined with long-term selective adherence. LSEC purification using our technique allowed to obtain 7.07±3.80 million LSEC per liver, while CD146+ MACS and short-term selective adherence yielded 2.94±1.28 and 0.99±0.66 million LSEC, respectively. Purity of the final cell preparation reached 95.10±2.58% when using our method. In contrast, CD146+ MACS and short-term selective adherence gave purities of 86.75±3.26% and 47.95±9.82%, respectively. Similarly, contamination by non-LSEC was the lowest when purification was performed using our technique, with a proportion of contaminating macrophages of only 1.87±0.77%. Further, isolated cells analysed by scanning electron microscopy presented typical LSEC fenestrations organized in sieve plates, demonstrating that the technique allowed to isolate bona fide LSEC. In conclusion, we described a reliable and reproducible technique for the isolation of high yields of pure LSEC in mice. This protocol provides an efficient method to prepare LSEC for studying their biological functions. - Highlights: • This protocol provides an efficient method to prepare primary mouse LSEC for studying their biological functions. • The liver cell dispersion step was improved by performing a retrograde cannulation of the liver. • The cell yield and the purity obtained were higher than comparative techniques in mice. • Contaminating macrophages were removed by introducing a CD11b- magnetic

  4. An optimized method for mouse liver sinusoidal endothelial cell isolation

    International Nuclear Information System (INIS)

    Meyer, Jeremy; Lacotte, Stéphanie; Morel, Philippe; Gonelle-Gispert, Carmen; Bühler, Léo

    2016-01-01

    The objective of the present study was to develop an accurate and reproducible method for liver sinusoidal endothelial cell (LSEC) isolation in mice. Non-parenchymal cells were isolated using a modified two-step collagenase digestion combined with Optiprep density gradient centrifugation. LSEC were further purified using two prevalent methods, short-term selective adherence and CD146+ magnetic-activated cell sorting (MACS), and compared in terms of cell yield, viability and purity to our purification technique using CD11b cell depletion combined with long-term selective adherence. LSEC purification using our technique allowed to obtain 7.07±3.80 million LSEC per liver, while CD146+ MACS and short-term selective adherence yielded 2.94±1.28 and 0.99±0.66 million LSEC, respectively. Purity of the final cell preparation reached 95.10±2.58% when using our method. In contrast, CD146+ MACS and short-term selective adherence gave purities of 86.75±3.26% and 47.95±9.82%, respectively. Similarly, contamination by non-LSEC was the lowest when purification was performed using our technique, with a proportion of contaminating macrophages of only 1.87±0.77%. Further, isolated cells analysed by scanning electron microscopy presented typical LSEC fenestrations organized in sieve plates, demonstrating that the technique allowed to isolate bona fide LSEC. In conclusion, we described a reliable and reproducible technique for the isolation of high yields of pure LSEC in mice. This protocol provides an efficient method to prepare LSEC for studying their biological functions. - Highlights: • This protocol provides an efficient method to prepare primary mouse LSEC for studying their biological functions. • The liver cell dispersion step was improved by performing a retrograde cannulation of the liver. • The cell yield and the purity obtained were higher than comparative techniques in mice. • Contaminating macrophages were removed by introducing a CD11b- magnetic

  5. A mouse model of alcoholic liver fibrosis-associated acute kidney injury identifies key molecular pathways

    International Nuclear Information System (INIS)

    Furuya, Shinji; Chappell, Grace A.; Iwata, Yasuhiro; Uehara, Takeki; Kato, Yuki; Kono, Hiroshi; Bataller, Ramon; Rusyn, Ivan

    2016-01-01

    Clinical data strongly indicate that acute kidney injury (AKI) is a critical complication in alcoholic hepatitis, an acute-on-chronic form of liver failure in patients with advanced alcoholic fibrosis. Development of targeted therapies for AKI in this setting is hampered by the lack of an animal model. To enable research into molecular drivers and novel therapies for fibrosis- and alcohol-associated AKI, we aimed to combine carbon tetrachloride (CCl 4 )-induced fibrosis with chronic intra-gastric alcohol feeding. Male C57BL/6J mice were administered a low dose of CCl 4 (0.2 ml/kg 2 × week/6 weeks) followed by alcohol intragastrically (up to 25 g/kg/day for 3 weeks) and with continued CCl 4 . We observed that combined treatment with CCl 4 and alcohol resulted in severe liver injury, more pronounced than using each treatment alone. Importantly, severe kidney injury was evident only in the combined treatment group. This mouse model reproduced distinct pathological features consistent with AKI in human alcoholic hepatitis. Transcriptomic analysis of kidneys revealed profound effects in the combined treatment group, with enrichment for damage-associated pathways, such as apoptosis, inflammation, immune-response and hypoxia. Interestingly, Havcr1 and Lcn2, biomarkers of AKI, were markedly up-regulated. Overall, this study established a novel mouse model of fibrosis- and alcohol-associated AKI and identified key mechanistic pathways. - Highlights: • Acute kidney injury (AKI) is a critical complication in alcoholic hepatitis • We developed a novel mouse model of fibrosis- and alcohol-associated AKI • This model reproduces key molecular and pathological features of human AKI • This animal model can help identify new targeted therapies for alcoholic hepatitis

  6. Positional specificity of saturated and unsaturated fatty acids in phosphatidic acid from rat liver

    NARCIS (Netherlands)

    Possmayer, F.; Scherphof, G.L.; Dubbelman, T.M.A.R.; Golde, L.M.G. van; Deenen, L.L.M. van

    1969-01-01

    1. 1. The relative incorporation of a number of radioactive fatty acids into the different glycerolipids of rat liver microsomes has been investigated. 2. 2. Studies on the distribution of the radioactivity incorporated into phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid

  7. 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

  8. A novel “humanized mouse” model for autoimmune hepatitis and the association of gut microbiota with liver inflammation

    Science.gov (United States)

    Yuksel, Muhammed; Wang, Yipeng; Tai, Ningwen; Peng, Jian; Guo, Junhua; Beland, Kathie; Lapierre, Pascal; David, Chella; Alvarez, Fernando; Colle, Isabelle; Yan, Huiping; Mieli-Vergani, Giorgina; Vergani, Diego; Ma, Yun; Wen, Li

    2016-01-01

    Background Autoimmune hepatitis (AIH) in humans is a severe inflammatory liver disease, characterized by interface hepatitis, the presence of circulating autoantibodies and hyper-gammaglobulinemia. There are two types of AIH, type-1 (AIH-1) and type-2 (AIH-2) characterized by distinct autoimmune serology. Patients with AIH-1 are positive for anti-smooth muscle and/or anti-nuclear (SMA/ANA) autoantibodies whereas patients with AIH-2 have anti-liver kidney microsomal type 1 (anti-LKM1) and/or anti-liver cytosol type 1 (anti-LC1) autoantibodies. Cytochrome P4502D6 (CYP2D6) is the antigenic target of anti-LKM1 and formiminotransferase cyclodeaminase (FTCD) is the antigenic target of anti-LC1. It is known that AIH, both type-1 and type-2, is strongly linked to the Human Leukocyte Antigen (HLA) alleles -DR3, -DR4 and -DR7. However, the direct evidence of the association of HLA with AIH is lacking. Methods We developed a novel mouse model of AIH using the HLA-DR3 transgenic mouse on the non-obese diabetic (NOD) background (HLA-DR3 NOD) by immunization of HLA-DR3− and HLA-DR3+ NOD mice with a DNA plasmid, coding for human CYP2D6/FTCD fusion protein. Results Immunization with CYP2D6/FTCD leads to a sustained elevation of alanine aminotransferase (ALT), development of ANA and anti-LKM1/anti-LC1 autoantibodies, chronic immune cell infiltration and parenchymal fibrosis on liver histology in HLA-DR3+ mice. Immunized mice also showed an enhanced Th1 immune response and paucity of the frequency of regulatory T-cell (Treg) in the liver. Moreover, HLA-DR3+ mice with exacerbated AIH showed reduced diversity and total load of gut bacteria. Conclusion Our humanized animal model has provided a novel experimental tool to further elucidate the pathogenesis of AIH and to evaluate the efficacy and safety of immunoregulatory therapeutic interventions in vivo. PMID:26185095

  9. Effect of treatment with cadmium on kinetic properties of Na+, K+-ATPase and glucose-6-phosphatase activity in rat liver microsomes

    International Nuclear Information System (INIS)

    Modi, Hiren R.; Patil, Nisha; Katyare, Surendra S.

    2008-01-01

    Studies on Cd hepatotoxicity have focused mainly on induction of cytochrome P 450 system and related enzymes. In the present study young adult male rats given a single intra-peritoneal injection of Cd (0.84 mg Cd/kg body weight) and effects on kinetic parameters rat liver microsomal Na + , K + -ATPase and G6Pase were evaluated at the end of 1 month and 1 week. The substrate and temperature kinetics parameters were examined and attempts were made to seek correlation with changes in lipid/phospholipid profiles. The Na + , K + ATPase activity decreased only in 1 week Cd-treated group but recovered at the end of 1 month. The activity resolved in two distinct kinetic components in control as well as the experimental groups. In 1 week Cd-treated group the K m value of both the components was unchanged, whereas V max value decreased. In 1-month Cd-treated group V max value only of component I increased. The catalytic efficiency of both the components was not affected in the experimental groups. In 1-week Cd-treated group the energy of activations at high-temperature range (E H ) and low-temperature range (E L ) decreased, whereas for 1-month Cd-treated group the energies of activations did not change. The G6Pase activity measured at 37 deg. C was high only in 1-month Cd-treated group. The activity resolved in two kinetically distinguishable components in control as well as in the experimental groups. K m value of component I decreased in both the Cd-treated groups. In 1-month Cd-treated group the V max value of component II increased. The catalytic efficiency of G6Pase was unchanged despite changes in K m and V max . In 1-week Cd-treated group the E H and E L decreased, whereas only E L showed decrease in 1-month Cd-treated group. Cholesterol (CHL) content increased in both the Cd-treated groups. Content of lysophospholipid (Lyso), spinghomyelin (SPM) and phosphatidic acid (PA) increased, whereas phosphatidylcholine (PC) and phosphatidylserine (PS) decreased in 1-week Cd

  10. Impact of associating liver partition and portal vein occlusion for staged hepatectomy on tumor growth in a mouse model of liver metastasis.

    Science.gov (United States)

    Kikuchi, Yutaro; Hiroshima, Yukihiko; Matsuo, Kenichi; Murakami, Takashi; Kawaguchi, Daisuke; Kasahara, Kohei; Tanaka, Kuniya

    2018-01-01

    The impact of associating liver partition and portal vein occlusion for staged hepatectomy (ALPPS) on tumor growth activity was investigated. A BALB/c mouse model (male, 8-10 weeks old) of liver metastasis labeled by red fluorescent protein was established. Changes in future liver remnant (FLR) volumes, tumor growth activity, and levels of cytokines and growth factors in liver tissues during the treatment period were compared among the models involving ALPPS, portal vein ligation (PVL), or sham operation. The ratio of the FLR volume to body weight at 24 h after the procedure was greater for ALPPS (4.45 ± 0.12 × 10 -2 ) than for PVL (3.79 ± 0.12 × 10 -2 ; P = 0.003) and sham operation (3.18 ± 0.16 × 10 -2 ; P < 0.001). No differences in tumor progression in the FLR were observed at any time point after the procedures. Within the deportalized liver (DL), although tumor progression was observed during a later period after ALPPS (9 days postoperative) and PVL (12 days postoperative), no acceleration of tumor growth after ALPPS was observed in an early period similar to PVL. ALPPS induces a rapid increase in FLR volume and avoids remnant tumor progression during the early postoperative period. Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

  11. Reductive metabolism of oxymatrine is catalyzed by microsomal CYP3A4

    Directory of Open Access Journals (Sweden)

    Liu W

    2015-10-01

    Full Text Available Wenqin Liu,1,2,* Jian Shi,1,2,* Lijun Zhu,2 Lingna Dong,1 Feifei Luo,2 Min Zhao,2 Ying Wang,2 Ming Hu,2,3 Linlin Lu,2 Zhongqiu Liu1,2 1Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China; 2International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, People’s Republic of China; 3Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, USA *These authors contributed equally to this work Abstract: Oxymatrine (OMT is a pharmacologically active primary quinolizidine alkaloid with various beneficial and toxic effects. It is confirmed that, after oral administration, OMT could be transformed to the more toxic metabolite matrine (MT, and this process may be through the reduction reaction, but the study on the characteristics of this transformation is limited. The aim of this study was to investigate the characteristics of this transformation of OMT in the human liver microsomes (HLMs and human intestinal microsomes (HIMs and the cytochrome P450 (CYP isoforms involved in this transformation. The current studies demonstrated that OMT could be metabolized to MT rapidly in HLMs and HIMs and CYP3A4 greatly contributed to this transformation. All HLMs, HIMs, and CYP3A4 isoform mediated reduction reaction followed typical biphasic kinetic model, and Km, Vmax, and CL were significant higher in HLMs than those in HIMs. Importantly, different oxygen contents could significantly affect the metabolism of OMT, and with the oxygen content decreased, the formation of metabolite was increased, suggesting this transformation was very likely a reduction reaction. Results of this in vitro study elucidated the metabolic pathways and characteristics of metabolism of OMT to MT and would provide a theoretical basis and guidance for the safe application of OMT

  12. Autoimmune liver disease 2007.

    Science.gov (United States)

    Muratori, Paolo; Granito, Alessandro; Pappas, Georgios; Muratori, Luigi; Lenzi, Marco; Bianchi, Francesco B

    2008-01-01

    Autoimmune liver disease (ALD) includes a spectrum of diseases which comprises both cholestatic and hepatitic forms: autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and the so called "overlap" syndromes where hepatitic and cholestatic damage coexists. All these diseases are characterized by an extremely high heterogeneity of presentation, varying from asymptomatic, acute (as in a subset of AIH) or chronic (with aspecific symptoms such as fatigue and myalgia in AIH or fatigue and pruritus in PBC and PSC). The detection and characterization of non organ specific autoantibodies plays a major role in the diagnostic approach of autoimmune liver disease; anti nuclear reactivities (ANA) and anti smooth muscle antibodies (SMA) mark type 1 AIH, liver kidney microsomal antibody type 1 (LKM1) and liver cytosol type 1 (LC1) are the serological markers of type 2 AIH; antimitochondrial antibodies (AMA) are associated with PBC, while no specific marker is found in PSC, since anticytoplasmic neutrophil antibodies with perinuclear pattern (atypical p-ANCA or p-ANNA) are also detected in a substantial proportion of type 1 AIH cases. Treatment options rely on immunosoppressive therapy (steroids and azathioprine) in AIH and on ursodeoxycholic acid in cholestatic conditions; in all these diseases liver transplantation remains the only therapeutical approach for the end stage of liver disease.

  13. IDH1 deficiency attenuates gluconeogenesis in mouse liver by impairing amino acid utilization.

    Science.gov (United States)

    Ye, Jing; Gu, Yu; Zhang, Feng; Zhao, Yuanlin; Yuan, Yuan; Hao, Zhenyue; Sheng, Yi; Li, Wanda Y; Wakeham, Andrew; Cairns, Rob A; Mak, Tak W

    2017-01-10

    Although the enzymatic activity of isocitrate dehydrogenase 1 (IDH1) was defined decades ago, its functions in vivo are not yet fully understood. Cytosolic IDH1 converts isocitrate to α-ketoglutarate (α-KG), a key metabolite regulating nitrogen homeostasis in catabolic pathways. It was thought that IDH1 might enhance lipid biosynthesis in liver or adipose tissue by generating NADPH, but we show here that lipid contents are relatively unchanged in both IDH1-null mouse liver and IDH1-deficient HepG2 cells generated using the CRISPR-Cas9 system. Instead, we found that IDH1 is critical for liver amino acid (AA) utilization. Body weights of IDH1-null mice fed a high-protein diet (HPD) were abnormally low. After prolonged fasting, IDH1-null mice exhibited decreased blood glucose but elevated blood alanine and glycine compared with wild-type (WT) controls. Similarly, in IDH1-deficient HepG2 cells, glucose consumption was increased, but alanine utilization and levels of intracellular α-KG and glutamate were reduced. In IDH1-deficient primary hepatocytes, gluconeogenesis as well as production of ammonia and urea were decreased. In IDH1-deficient whole livers, expression levels of genes involved in AA metabolism were reduced, whereas those involved in gluconeogenesis were up-regulated. Thus, IDH1 is critical for AA utilization in vivo and its deficiency attenuates gluconeogenesis primarily by impairing α-KG-dependent transamination of glucogenic AAs such as alanine.

  14. Mechanism of microsomal metabolism of benzene to phenol

    Energy Technology Data Exchange (ETDEWEB)

    Hinson, J.A.; Freeman, J.P.; Potter, D.W.; Mitchum, R.K.; Evans, F.E.

    1985-05-01

    The mechanism of microsomal hydroxylation of benzene to phenol has been studied by examining the microsomal metabolism of the specifically deuterated derivative 1,3,5-(/sub 2/H/sup 3/)benzene. Evidence for the formation of the following four products was obtained: 2,3,5-(/sub 2/H/sup 3/)phenol, 3,5-(/sub 2/H/sup 2/)phenol, 2,4,6-(/sub 2/H/sup 3/)phenol, and 2,4-(/sub 2/H/sup 2/)phenol. The presence of 2,3,5-(2H3)phenol and 2,4-(/sub 2/H/sup 2/)phenol shows that, in the microsomal metabolism of benzene to phenol, a NIH shift had occurred. A deuterium isotope effect (kH/kD) of approximately 4 was detected in both the meta- and para-deuterated phenols. This finding indicates that cyclohexadienone, formed either by isomerization of the epoxide or directly from the enzyme-substrate complex, is a major intermediate in the metabolism of benzene to phenol.

  15. Proteome analysis of a hepatocyte-specific BIRC5 (survivin)-knockout mouse model during liver regeneration.

    Science.gov (United States)

    Bracht, Thilo; Hagemann, Sascha; Loscha, Marius; Megger, Dominik A; Padden, Juliet; Eisenacher, Martin; Kuhlmann, Katja; Meyer, Helmut E; Baba, Hideo A; Sitek, Barbara

    2014-06-06

    The Baculoviral IAP repeat-containing protein 5 (BIRC5), also known as inhibitor of apoptosis protein survivin, is a member of the chromosomal passenger complex and a key player in mitosis. To investigate the function of BIRC5 in liver regeneration, we analyzed a hepatocyte-specific BIRC5-knockout mouse model using a quantitative label-free proteomics approach. Here, we present the analyses of the proteome changes in hepatocyte-specific BIRC5-knockout mice compared to wildtype mice, as well as proteome changes during liver regeneration induced by partial hepatectomy in wildtype mice and mice lacking hepatic BIRC5, respectively. The BIRC5-knockout mice showed an extensive overexpression of proteins related to cellular maintenance, organization and protein synthesis. Key regulators of cell growth, transcription and translation MTOR and STAT1/STAT2 were found to be overexpressed. During liver regeneration proteome changes representing a response to the mitotic stimulus were detected in wildtype mice. Mainly proteins corresponding to proliferation, cell cycle and cytokinesis were up-regulated. The hepatocyte-specific BIRC5-knockout mice showed impaired liver regeneration, which had severe consequences on the proteome level. However, several proteins with function in mitosis were found to be up-regulated upon the proliferative stimulus. Our results show that the E3 ubiquitin-protein ligase UHRF1 is strongly up-regulated during liver regeneration independently of BIRC5.

  16. [The effect of berberine administration of evaluation of the functional state of rat liver after ligation of common bile duct].

    Science.gov (United States)

    Zverinskiĭ, I V; Mel'nichenko, N G; Poplavskiĭ, V A; Sut'ko, I P; Telegin, P G; Shliakhtun, A G

    2013-01-01

    On the eighth day after ligation of the common bile duct in rats a significant increase in the serum content of total lipids, cholesterol bilirubin and ALT, alkaline phosphatase, and gamma-glutamyltransferase was observed. In the microsomal fraction there was a marked decrease in the content and activity of microsomal monooxygenases. Introperitoneal injection of berberine (10 mg/kg) for 6 days caused a partial normalization of permeability of hepatocytes plasma membranes and activity microsomal flavin-containing monooxygenases. It is suggested that berberine is a substrate and inducer of flavin-containing monooxygenases. Membrane-stabilizing effect of berberine is probably realized at the level of inhibition of prooxidant status of liver cells.

  17. A new liver function test using the asialoglycoprotein-receptor system on the liver cell membrane, 3

    International Nuclear Information System (INIS)

    Hazama, Hiroshi; Kawa, Soukichi; Kubota, Yoshitsugu

    1986-01-01

    We evaluated the vilidity of a new liver function test using liver scintigraphy based on the asialoglycoprotein (ASGP) receptor system on the liver cell membrane in rats with galactosamine-induced acute liver disorder and those with carbon tetra-chloride-induced chronic liver disorder. Neoglycoprotein (GHSA) produced by combining human serum albumin with 32 galactose units was labeled with 99m Tc and administered (50 μg/100 g body weight) to rats with acute or chronic liver disorder. Clearance curves were produced based on liver scintigrams and analysed using the two-compartment model to obtain parameters. In acute liver disorder, the prolongation of 99m Tc-GHSA clearance and the decrease in ASGP receptor activities correlated well to the increase in serum GOT and the decrease in the esterified to total cholesterol ratio (E/T ratio); in chronic liver disorder, they correlated significantly to the increase in the content of liver hydroxyproline (Hyp) which increased in proportion to the severity of liver fibrosis studied histologically, and to the decrease in the contents of cytochrome P-450 and cytochrome b 5 in liver microsomes. Significant correlation was observed between the prolongation of 99m Tc-GHSA clearance and the decrease in ASGP receptor activities in both acute and chronic liver disorders. These findings indicate that the measurement of 99m Tc-GHSA clearance can be a new liver function test sensitively reflecting the severity of liver damage. (author)

  18. The mouse liver displays daily rhythms in the metabolism of phospholipids and in the activity of lipid synthesizing enzymes.

    Science.gov (United States)

    Gorné, Lucas D; Acosta-Rodríguez, Victoria A; Pasquaré, Susana J; Salvador, Gabriela A; Giusto, Norma M; Guido, Mario Eduardo

    2015-02-01

    The circadian system involves central and peripheral oscillators regulating temporally biochemical processes including lipid metabolism; their disruption leads to severe metabolic diseases (obesity, diabetes, etc). Here, we investigated the temporal regulation of glycerophospholipid (GPL) synthesis in mouse liver, a well-known peripheral oscillator. Mice were synchronized to a 12:12 h light-dark (LD) cycle and then released to constant darkness with food ad libitum. Livers collected at different times exhibited a daily rhythmicity in some individual GPL content with highest levels during the subjective day. The activity of GPL-synthesizing/remodeling enzymes: phosphatidate phosphohydrolase 1 (PAP-1/lipin) and lysophospholipid acyltransferases (LPLATs) also displayed significant variations, with higher levels during the subjective day and at dusk. We evaluated the temporal regulation of expression and activity of phosphatidylcholine (PC) synthesizing enzymes. PC is mainly synthesized through the Kennedy pathway with Choline Kinase (ChoK) as a key regulatory enzyme or through the phosphatidylethanolamine (PE) N-methyltransferase (PEMT) pathway. The PC/PE content ratio exhibited a daily variation with lowest levels at night, while ChoKα and PEMT mRNA expression displayed maximal levels at nocturnal phases. Our results demonstrate that mouse liver GPL metabolism oscillates rhythmically with a precise temporal control in the expression and/or activity of specific enzymes.

  19. Monolignol biosynthesis in microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Guo, Dianjing; Chen, Fang; Dixon, Richard A

    2002-11-01

    Microsomal preparations from lignifying stems of alfalfa (Medicago sativa L.) contained coniferaldehyde 5-hydroxylase activity and immunodetectable caffeic acid 3-O-methyltransferase (COMT), and catalyzed the S-adenosyl L-methionine (SAM) dependent methylation of caffeic acid, caffeyl aldehyde and caffeyl alcohol. When supplied with NADPH and SAM, the microsomes converted caffeyl aldehyde to coniferaldehyde, 5-hydroxyconiferaldehyde, and traces of sinapaldehyde. Coniferaldehyde was a better precursor of sinapaldehyde than was 5-hydroxyconiferaldehyde. The alfalfa microsomes could not metabolize 4-coumaric acid, 4-coumaraldehyde, 4-coumaroyl CoA, or ferulic acid. No metabolism of monolignol precursors was observed in microsomal preparations from transgenic alfalfa down-regulated in COMT expression. In most microsomal preparations, the level of the metabolic conversions was independent of added recombinant COMT. Taken together, the data provide only limited support for the concept of metabolic channeling in the biosynthesis of S monolignols via coniferaldehyde.

  20. A mouse model of alcoholic liver fibrosis-associated acute kidney injury identifies key molecular pathways

    Energy Technology Data Exchange (ETDEWEB)

    Furuya, Shinji; Chappell, Grace A.; Iwata, Yasuhiro [Department of Veterinary Integrative Biosciences, Texas A& M University, College Station, TX (United States); Uehara, Takeki; Kato, Yuki [Laboratory of Veterinary Pathology, Osaka Prefecture University, Osaka (Japan); Kono, Hiroshi [First Department of Surgery, University of Yamanashi, Yamanashi (Japan); Bataller, Ramon [Division of Gastroenterology & Hepatology, Department of Medicine, University of North Carolina, Chapel Hill, NC (United States); Rusyn, Ivan, E-mail: irusyn@tamu.edu [Department of Veterinary Integrative Biosciences, Texas A& M University, College Station, TX (United States)

    2016-11-01

    Clinical data strongly indicate that acute kidney injury (AKI) is a critical complication in alcoholic hepatitis, an acute-on-chronic form of liver failure in patients with advanced alcoholic fibrosis. Development of targeted therapies for AKI in this setting is hampered by the lack of an animal model. To enable research into molecular drivers and novel therapies for fibrosis- and alcohol-associated AKI, we aimed to combine carbon tetrachloride (CCl{sub 4})-induced fibrosis with chronic intra-gastric alcohol feeding. Male C57BL/6J mice were administered a low dose of CCl{sub 4} (0.2 ml/kg 2 × week/6 weeks) followed by alcohol intragastrically (up to 25 g/kg/day for 3 weeks) and with continued CCl{sub 4}. We observed that combined treatment with CCl{sub 4} and alcohol resulted in severe liver injury, more pronounced than using each treatment alone. Importantly, severe kidney injury was evident only in the combined treatment group. This mouse model reproduced distinct pathological features consistent with AKI in human alcoholic hepatitis. Transcriptomic analysis of kidneys revealed profound effects in the combined treatment group, with enrichment for damage-associated pathways, such as apoptosis, inflammation, immune-response and hypoxia. Interestingly, Havcr1 and Lcn2, biomarkers of AKI, were markedly up-regulated. Overall, this study established a novel mouse model of fibrosis- and alcohol-associated AKI and identified key mechanistic pathways. - Highlights: • Acute kidney injury (AKI) is a critical complication in alcoholic hepatitis • We developed a novel mouse model of fibrosis- and alcohol-associated AKI • This model reproduces key molecular and pathological features of human AKI • This animal model can help identify new targeted therapies for alcoholic hepatitis.

  1. Mouse precision-cut liver slices as an ex vivo model to study idiosyncratic drug-induced liver injury.

    Science.gov (United States)

    Hadi, Mackenzie; Chen, Yixi; Starokozhko, Viktoriia; Merema, Marjolijn T; Groothuis, Geny M M

    2012-09-17

    Idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. IDILI may arise from the interaction of a drug's reactive metabolite with a mild inflammation that renders the liver more sensitive to injury resulting in increased toxicity (inflammatory stress hypothesis). Aiming to develop a robust ex vivo screening method to study inflammatory stress-related IDILI mechanisms and to find biomarkers that can detect or predict IDILI, mouse precision-cut liver slices (mPCLS) were coincubated for 24 h with IDILI-related drugs and lipopolysaccharide. Lipopolysaccharide exacerbated ketoconazole (15 μM) and clozapine (45 μM) toxicity but not their non-IDILI-related comparators, voriconazole (1500 μM) and olanzapine (45 μM). However, the other IDILI-related drugs tested [diclofenac (200 μM), carbamazepine (400 μM), and troglitazone (30 μM)] did not cause synergistic toxicity with lipopolysaccharide after 24 h of incubation. Lipopolysaccharide further decreased the reduced glutathione levels caused by ketoconazole or clozapine in mPCLS after 24 h of incubation, which was not the case for the other drugs. Lipopolysaccharide significantly increased nitric oxide (NO), cytokine, and chemokine release into the mPCLS media, while the treatment with the drugs alone did not cause any substantial change. All seven drugs drastically reduced lipopolysaccharide-induced NO production. Interestingly, only ketoconazole and clozapine increased the lipopolysaccharide-induced granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) release. Pilot experiments showed that diclofenac and troglitazone, but not carbamazepine, demonstrated synergistic toxicity with lipopolysaccharide after a longer incubation of 48 h in mPCLS. In conclusion, we have developed an ex vivo model to detect inflammatory stress-related liver toxicity and identified ketoconazole, clozapine

  2. Regulation of rat liver cytochrome P450j, a high affinity N-nitrosodimethylamine demethylase (NDMAD)

    International Nuclear Information System (INIS)

    Thomas, P.E.; Bandiera, S.; Maines, S.L.; Ryan, D.E.; Levin, W.

    1987-01-01

    Purified IgG from sera of rabbits immunized with homogeneous P450j was absorbed to produce monospecific anti-P450j. Results using anti-P450j in ELISA show that rat liver microsomal P450j content decreases between 3 and 6 wks of age in both sexes. Several xenobiotics (Aroclor 1254, mirex and 3-methylcholanthrene) repressed P450j levels when administered to male rats. In contrast, hepatic levels of P450j were induced by isoniazid, dimethylsulfoxide, pyrazole, 4-methylpyrazole, ethanol and chemically-induced diabetes. P450j levels were measurable in kidney, whereas this isozyme was barely detectable in lung, ovaries and testes; however, extra-hepatic P450j was inducible by isoniazid. Between 80-90% of microsomal NDMAD was inhibited by anti-P450j whether the microsomes were isolated from untreated rats or animals administered inducers or repressors of P450j. Results obtained with the reconstituted system suggest that the remaining microsomal NDMAD resistant to antibody inhibition is the result of the inaccessibility of a certain proportion of P450j due to interference by NADPH-P450 reductase. P450j content and NDMAD activity correlated well in microsomes from rats of all treatment groups. The evidence indicates that P450j is the primary, and possibly only, microsomal catalyst of NDMAD at substrate concentrations relevant to hepatocarcinogenesis induced by NDMA

  3. Preventive effect of Dioscorea japonica on squamous cell carcinoma of mouse skin involving down-regulation of prostaglandin E2 synthetic pathway.

    Science.gov (United States)

    Tsukayama, Izumi; Toda, Keisuke; Takeda, Yasunori; Mega, Takuto; Tanaka, Mitsuki; Kawakami, Yuki; Takahashi, Yoshitaka; Kimoto, Masumi; Yamamoto, Kei; Miki, Yoshimi; Murakami, Makoto; Suzuki-Yamamoto, Toshiko

    2018-03-01

    Hyperproduced prostaglandin E 2 by cyclooxygenase-2 and microsomal prostaglandin E synthase-1 evokes several pathophysiological responses such as inflammation and carcinogenesis. Our recent study demonstrated that Dioscorea japonica extract suppressed the expression of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 and induced apoptosis in lung carcinoma A549 cells. In the present study, we investigated the effects of Dioscorea japonica on squamous cell carcinoma of mouse skin. Dioscorea japonica feeding and Dioscorea japonica extract topical application suppressed the expression of cyclooxygenase-2, microsomal prostaglandin E synthase-1, interleukin-1β and interleukin-6 and inhibited tumor formation, hyperplasia and inflammatory cell infiltration. Immunohistochemical analyses showed the immunoreactivities of cyclooxygenase-2 and microsomal prostaglandin E synthase-1 in tumor keratinocytes and stronger immunoreactivities of cyclooxygenase-2 and hematopoietic prostaglandin D synthase in epidermal dendritic cells (Langerhans cells). Treatment with Dioscorea japonica decreased the immunoreactivity of cyclooxygenase-2 and microsomal prostaglandin E synthase-1. These results indicate that Dioscorea japonica may have inhibitory effects on inflammation and carcinogenesis via suppression of the prostaglandin E 2 synthetic pathway.

  4. Microarray data reveal relationship between Jag1 and Ddr1 in mouse liver.

    Directory of Open Access Journals (Sweden)

    Lara A Underkoffler

    Full Text Available Alagille syndrome is an autosomal dominant disorder involving bile duct paucity and cholestasis in addition to cardiac, skeletal, ophthalmologic, renal and vascular manifestations. Mutations in JAG1, encoding a ligand in the Notch signaling pathway, are found in 95% of patients meeting clinical criteria for Alagille syndrome. In order to define the role of Jag1 in the bile duct developmental abnormalities seen in ALGS, we previously created a Jag1 conditional knockout mouse model. Mice heterozygous for the Jag1 conditional and null alleles demonstrate abnormalities in postnatal bile duct growth and remodeling, with portal expansion and increased numbers of malformed bile ducts. In this study we report the results of microarray analysis and identify genes and pathways differentially expressed in the Jag1 conditional/null livers as compared with littermate controls. In the initial microarray analysis, we found that many of the genes up-regulated in the Jag1 conditional/null mutant livers were related to extracellular matrix (ECM interactions, cell adhesion and cell migration. One of the most highly up-regulated genes was Ddr1, encoding a receptor tyrosine kinase (RTK belonging to a large RTK family. We have found extensive co-localization of Jag1 and Ddr1 in bile ducts and blood vessels in postnatal liver. In addition, co-immunoprecipitation data provide evidence for a novel protein interaction between Jag1 and Ddr1. Further studies will be required to define the nature of this interaction and its functional consequences, which may have significant implications for bile duct remodeling and repair of liver injury.

  5. Silymarin attenuated hepatic steatosis through regulation of lipid metabolism and oxidative stress in a mouse model of nonalcoholic fatty liver disease (NAFLD).

    Science.gov (United States)

    Ni, Xunjun; Wang, Haiyan

    2016-01-01

    Silymarin, which derived from the milk thistle plant (silybum marianum), has been used for centuries as a natural remedy for diseases of the liver and biliary tract. Considering the therapeutic potential to liver disease, we tested efficacy of silymarin on hepatic steatosis with a high fat diet (HFD)-induced mouse model of non-alcoholic fatty liver disease (NAFLD), and investigated possible effects on lipid metabolic pathways. In our study, silymarin could attenuate the hepatic steatosis, which was proved by both Oil Red O staining and hepatic triglyceride (TG) level determination. Furthermore, compared with INT-747, a potent and selective FXR agonist, silymarin could preserve plasmatic high-density lipoprotein cholesterol (HDL-C) to a higher level and low-density lipoprotein cholesterol (LDL-C) to a lower level, which benefited more to the circulation system. Through real-time PCR analysis, we clarified a vital protective role of silymarin in mRNA regulation of genes involved in lipid metabolism and oxidative stress. It was also shown that silymarin had no effects on body weight, food intake, and liver transaminase. Taken together, silymarin could attenuate hepatic steatosis in a mouse model of NAFLD through regulation of lipid metabolism and oxidative stress, and benefit to the circulation system. All these findings shed new light on NAFLD treatment.

  6. Usage of adenovirus expressing thymidine kinase mediated hepatocellular damage for enabling mouse liver repopulation with allogenic or xenogenic hepatocytes.

    Directory of Open Access Journals (Sweden)

    Daniel Moreno

    Full Text Available It has been shown that the liver of immunodeficient mice can be efficiently repopulated with human hepatocytes when subjected to chronic hepatocellular damage. Mice with such chimeric livers represent useful reagents for medical and clinical studies. However all previously reported models of humanized livers are difficult to implement as they involve cross-breeding of immunodeficient mice with mice exhibiting genetic alterations causing sustained hepatic injury. In this paper we attempted to create chimeric livers by inducing persistent hepatocellular damage in immunodeficient Rag2(-/- γc(-/- mice using an adenovirus encoding herpes virus thymidine kinase (AdTk and two consecutive doses of ganciclovir (GCV. We found that this treatment resulted in hepatocellular damage persisting for at least 10 weeks and enabled efficient engraftment and proliferation within the liver of either human or allogenic hepatocytes. Interestingly, while the nodules generated from the transplanted mouse hepatocytes were well vascularized, the human hepatocytes experienced progressive depolarization and exhibited reduced numbers of murine endothelial cells inside the nodules. In conclusion, AdTk/GCV-induced liver damage licenses the liver of immunodeficient mice for allogenic and xenogenic hepatocyte repopulation. This approach represents a simple alternative strategy for chimeric liver generation using immunodeficient mice without additional genetic manipulation of the germ line.

  7. Obstructive Sleep Apnea and Non-alcoholic Fatty Liver Disease: Is the Liver Another Target?

    Directory of Open Access Journals (Sweden)

    Aibek eMirrakhimov

    2012-10-01

    Full Text Available Obstructive sleep apnea (OSA is recurrent obstruction of the upper airway during sleep leading to intermittent hypoxia (IH. OSA has been associated with all components of the metabolic syndrome as well as with non-alcoholic fatty liver disease (NAFLD. NAFLD is a common condition ranging in severity from uncomplicated hepatic steatosis to steatohepatitis (NASH, liver fibrosis and cirrhosis. The gold standard for the diagnosis and staging of NAFLD is liver biopsy. Obesity and insulin resistance lead to liver steatosis, but the causes of the progression to NASH are not known. Emerging evidence suggests that OSA may play a role in the progression of hepatic steatosis and the development of NASH. Several cross-sectional studies showed that the severity of IH in patients with OSA predicted the severity of NAFLD on liver biopsy. However, neither prospective nor interventional studies with continuous positive airway pressure (CPAP treatment have been performed. Studies in a mouse model showed that IH causes triglyceride accumulation in the liver and liver injury as well as hepatic inflammation. The mouse model provided insight in the pathogenesis of liver injury showing that (1 IH accelerates the progression of hepatic steatosis by inducing adipose tissue lipolysis and increasing free fatty acids (FFA flux into the liver; (2 IH up-regulates lipid biosynthetic pathways in the liver; (3 IH induces oxidative stress in the liver; (4 IH up-regulates hypoxia inducible factor 1 alpha and possibly HIF-2 alpha, which may increase hepatic steatosis and induce liver inflammation and fibrosis. However, the role of FFA and different transcription factors in the pathogenesis of IH-induced NAFLD is yet to be established. Thus, multiple lines of evidence suggest that IH of OSA may contribute to the progression of NAFLD but definitive clinical studies and experiments in the mouse model have yet to be done.

  8. The feasibility research of galactosyl-anti-mouse CD3 monoclonal antibody being used as carrier of immunotherapy after surgical operation of liver cancer

    International Nuclear Information System (INIS)

    Li Yunchun; Guan Changtian; Yang Xiaochuan; He Sheng; Jiang Ping; Yuan Lin

    2000-01-01

    Objective: To probe into the feasibility of galactosyl-anti-mouse CD 3 monoclonal antibody (Gal-Ant-CD 3 McAb) being used as carrier of immunotherapy after surgical operation of liver cancer. Methods: Gal-Ant-CD 3 McAb was prepared by the covalent coupling of anti-mouse CD 3 monoclonal antibody (Ant-CD 3 McAb) with a bifunctional reagent, 2-imino-2-methoxyethyl-1-thio-galactose. After Gal-Ant-CD 3 McAb and Ant-CD 3 McAb were labelled with 131 I or 125 I, the data of biodistribution in mice, and of imaging in rabbit were obtained. After tumour infiltrating lymphocytes (TIL) and Gal-Ant-CD 3 McAb were coupled into Gal-Ant-CD 3 McAb-TIL, its liver taxis and cytotoxic activity against autologous cancer cells were measured in vitro. Results: Gal-Ant-CD 3 McAb had remarkable livertaxis and its uptake in per gram liver was (59.0 +- 2.1)% that was more than two-fold higher than that of Ant-CD 3 McAb. Gal-Ant-CD 3 McAb-TIL had an obvious liver taxis and cytotoxic activity against autologous cancer cells in vitro. Conclusion: Gal-Ant-CD 3 McAb can be used as the carrier of immunotherapy after surgical operation of liver cancer

  9. Modification of nanocellulose by poly-lysine can inhibit the effect of fumonisin B1 on mouse liver cells.

    Science.gov (United States)

    Jebali, Ali; Yasini Ardakani, Seyed Ali; Shahdadi, Hossein; Balal Zadeh, Mohammad Hossein; Hekmatimoghaddam, Seyedhossein

    2015-02-01

    Fumonisin B1 is an important mycotoxin, mainly produced by Fusarium verticillioides. It has toxic effects on liver, brain, and kidney cells. The first aim of this study was to synthesize nanocellulose modified with poly-lysine (NMPL), and the second aim was to evaluate the adsorption of fumonisin B1 by NMPL. As third aim, the function of mouse liver cells was investigated after exposure to fumonisin B1, and fumonisin B1+ NMPL. In this study, NMPL was prepared using cross-linker, and then incubated with fumonisin B1 at controlled conditions. After incubation, the adsorption and release of fumonisin B1 were evaluated in each condition. Next, mouse liver cells were separately exposed to fumonisin B1, NMPL, and (fumonisin B1+NMPL). Then, the level of aniline aminotransferase (ALT) and aspartate aminotransferase (AST) was evaluated. It was found that both adsorption and release of fumonisin B1 were not affected by temperature and incubation time, but affected by pH and concentration of NMPL. Also, this study showed NMPL could adsorb fumonisin B1 in different foodstuffs. Importantly, although the levels of ALT and AST were increased when the cells were treated with fumonisin B1 alone, they were not affected when exposed to NMPL or (fumonisin B1+NMPL). The authors suggest that NMPL is a good adsorbent to remove and inhibit fumonisin B1. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Microsomal biotransformation of chlorpyrifos, parathion and fenthion in rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch): mechanistic insights into interspecific differences in toxicity

    Science.gov (United States)

    Lavado, Ramon

    2010-01-01

    Rainbow trout often serve as a surrogate species evaluating xenobiotic toxicity in cold-water species including other salmonids of the same genus, which are listed as threatened or endangered. Biotransformation tends to show species-specific patterns that influence susceptibility to xenobiotic toxicity, particularly organophoshpate insecticides (OPs). To evaluate the contribution of biotransformation in the mechanism of toxicity of three organophosphate (phosphorothionate) insecticides, chlorpyrifos, parathion and fenthion, microsomal bioactivation and detoxification pathways were measured in gills, liver and olfactory tissues in juvenile rainbow trout (Oncorhynchus mykiss) and compared to juvenile coho salmon (Oncorhynchus kisutch). Consistent with species differences in acute toxicity, significantly higher chlorpyrifos bioactivation was found in liver microsomes of rainbow trout (up to 2-fold) when compared with coho salmon. Although bioactivation to the oxon was observed, the catalytic efficiency towards chlorpyrifos dearylation (detoxification) was significantly higher in liver for both species (1.82 and 0.79 for trout and salmon, respectively) when compared to desulfuration (bioactivation). Bioactivation of parathion to paraoxon was significantly higher (up to 2.2-fold) than detoxification to p-nitrophenol in all tissues of both species with rates of conversion in rainbow trout, again significantly higher than coho salmon. Production of fenoxon and fenthion sulfoxides from fenthion was detected only in liver and gills of both species with activities in rainbow trout significantly higher than coho salmon. NADPH-Dependent hydrolysis of fenthion was observed in all tissues, and was the only activity detected in olfactory tissues. These results indicate rainbow trout are more sensitive than coho salmon to the acute toxicity of OP pesticides because trout have higher catalytic rates of oxon formation. Thus, rainbow trout may serve as a conservative surrogate

  11. Comparison of the subcellular distribution of monomeric 239Pu and 59Fe in the liver of rat, mouse, and Syrian and Chinese hamsters

    International Nuclear Information System (INIS)

    Winter, R.; Seidel, A.

    1982-01-01

    The subcellular distribution of 239 Pu and 59 Fe 10 days after intravenous injection as a citrate complex was investigated by sucrose density gradient centrifugation in the liver of rat, mouse, and Syrian and Chinese hamsters. Lysosomes were separated from other cell constituents by injection of the nonionic detergent Triton WR 1339 4 days before sacrifice. The Triton-induced decrease in the density of the lysosomes was very similar in all four animal species and was followed closely by a corresponding decrease of the median density of the 239 Pu profiles in rat, mouse, and, to a smaller extent, Syrian hamster. However, in Chinese hamster a clear correspondence between lysosomes and 239 Pu was not found 10 days after nuclide injection. It was concluded that lysosomes are the main storage organelles fo 239 Pu in the liver of rat and mouse and that in all four animal species mitochondria and endoplasmic reticulum do not play any significant role in binding the radionuclide. The relevance of pericellular membranes has to be checked. The distribution patterns of 59 Fe and 239 Pu were quite different

  12. Enantioselective N-demethylation and hydroxylation of sibutramine in human liver microsomes and recombinant cytochrome p-450 isoforms.

    Science.gov (United States)

    Shinde, Dhananjay D; Kim, Min-Jung; Jeong, Eun-Sook; Kim, Yang-Weon; Lee, Ji-Woo; Shin, Jae-Gook; Kim, Dong-Hyun

    2014-01-01

    The enantioselective metabolism of sibutramine was examined using human liver microsomes (HLM) and recombinant cytochrome P-450 (CYP) isoforms. This drug is metabolized to N-mono-desmethyl- (M1) and N,N-di-desmethylsibutramine (M2), and subsequent hydroxylation results in hydroxyl M1 (HM1) and hydroxyl M2 (HM2). No significant difference was noted in formation of M1from sibutramine between R- and S-sibutramine in HLM. However, S-enantiomers of M1 and M2 were preferentially metabolized to M2, HM1, and HM2compared to R-enantiomers in HLM, and intrinsic clearance (Clint) ratios of S-enantiomers/R-enantiomers were 1.97, 4.83, and 9.94 for M2, HM1, and HM2, respectively. CYP3A4 and CYP3A5 were only involved in the formation of M1, whereas CYP2B6 and CYP2C19 were responsible for all metabolic reactions of sibutramine. CYP2C19 and CYP3A5 displayed catalytic preference for S-sibutramine to S-M1, whereas CYP2B6 and CYP3A4 showed little or no stereoselectivity in metabolism of sibutramine to M1. In the case of M2 formation, CYP2B6 metabolized S-M1 more rapidly than R-M1 with a Clint ratio of 2.14. However, CYP2C19 catalyzed less S-M1 than R-M1 and the Clint ratio of S-M1 to R-M1 was 0.65. The most significant enantioselectivity was observed in formation of HM1 from M1, and HM2 from M2. CYP2B6 and CYP2C19 exhibited preferential catalysis of formation of hydroxyl metabolites from S-enantiomers rather than R-enantiomers. These results indicate that S-sibutramine was more rapidly metabolized by CYP isoforms than R-sibutramine, and that enantioselective metabolism needs to be considered in drug interactions involving sibutramine and co-administered drugs.

  13. Activation versus inhibition of microsomal glutathione S-transferase activity by acrolein. Dependence on the concentration and time of acrolein exposure.

    Science.gov (United States)

    Sthijns, Mireille M J P E; den Hartog, Gertjan J M; Scasso, Caterina; Haenen, Jan P; Bast, Aalt; Haenen, Guido R M M

    2017-09-25

    The toxicity of acrolein, an α,β-unsaturated aldehyde, is due to its soft electrophilic nature and primarily involves the adduction of protein thiols. The thiol glutathione (GSH) forms the first line of defense against acrolein. The present study confirms that acrolein added to isolated rat liver microsomes can increase microsomal GSH transferase (MGST) activity 2-3 fold, which can be seen as a direct adaptive increase in the protection against acrolein. At a relatively high exposure level, acrolein appeared to inhibit MGST. The activation is due to adduction of thiol groups, and the inactivation probably involves adduction of amino groups in the enzyme by acrolein. The preference of acrolein to react with thiol groups over amino groups can explain why the enzyme is activated at a low exposure level and inhibited at a high exposure level of acrolein. These opposite forms of direct adaptation on the level of enzyme activity further narrow the thin line between survival and promotion of cell death, governed by the level of exposure. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. 2,2',3,3',6,6'-Hexachlorobiphenyl (PCB 136) is Enantioselectively Oxidized to Hydroxylated Metabolites by Rat Liver Microsomes

    Science.gov (United States)

    Wu, Xianai; Pramanik, Ananya; Duffel, Michael W.; Hrycay, Eugene G.; Bandiera, Stelvio M.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela

    2011-01-01

    Developmental exposure to multiple-ortho substituted polychlorinated biphenyls (PCBs) causes adverse neurodevelopmental outcomes in laboratory animals and humans by mechanisms involving the sensitization of Ryanodine receptors (RyRs). In the case of PCB 136, the sensitization of RyR is enantiospecific, with only (-)-PCB 136 being active. However, the role of enantioselective metabolism in the developmental neurotoxicity of PCB 136 is poorly understood. The present study employed hepatic microsomes from phenobarbital (PB-), dexamethasone (DEX-) and corn oil (VEH-)treated male Sprague-Dawley rats to investigate the hypothesis that PCB 136 atropisomers are enantioselectively metabolized by P450 enzymes to potentially neurotoxic, hydroxylated PCB 136 metabolites. The results demonstrated the time- and isoform-dependent formation of three metabolites, with 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) being the major metabolite. The formation of 5-OH-PCB 136 increased with the activity of P450 2B enzymes in the microsomal preparation, which is consistent with PCB 136 metabolism by rat P450 2B1. The minor metabolite 4-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol) was produced by a currently unidentified P450 enzymes. An enantiomeric enrichment of (-)-PCB 136 was observed in microsomal incubations due to the preferential metabolism of (+)-PCB 136 to the corresponding 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) atropisomer. 4-OH-PCB 136 displayed an enrichment of the atropisomer formed from (-)-PCB 136; however, the enrichment of this metabolite atropisomer didn't affect the enantiomeric enrichment of the parent PCB because 4-OH-PCB 136 is only a minor metabolite. Although the formation of 5- and 4-OH-PCB 136 atropisomers increased with time, the enantioselective formation of the OH-PCB metabolites resulted in constant enantiomeric enrichment, especially at later incubation times. These observations not only demonstrate that the chiral signatures of

  15. Transmission electron microscopy of heart and liver tissues from rats fed with gums arabic and tragacanth.

    Science.gov (United States)

    Anderson, D M; Ashby, P; Busuttil, A; Kempson, S A; Lawson, M E

    1984-04-01

    Transmission electron microscopy has been used to examine the ultrastructure of rat hearts and livers after diet supplementation with (a) 0, 0.5, 1.5, 2.5 and 3.5% (w/w) gum tragacanth (GT) for 91 days, (b) 0 and 1% GT for 5 days (c) 0, 1, 4 and 8% (w/w) gum arabic (GA) for 28 days. The preparation and scrutiny of the electron micrographs was undertaken by two independent teams of specialists. There were no detectable abnormalities in any of the organelles in the heart and liver specimens from any of the test animals and no inclusions nor other pathological changes were observed. All micrographs showed normal, healthy tissues; particular attention was given to the mitochondria in hepatocytes as they serve as sensitive indicators of the health and state of activity of cells. In addition, the data obtained from assays of the microsomal protein and cytochrome P-450 content of the livers showed that GA and GT did not cause inductive effects. These results do not support earlier suggestions, based on in vitro assays, that GA and GT cause changes in the function of rat heart and liver mitochondria and liver microsomes; however, they confirm a report by Zbinden that the ingestion of GT does not produce abnormalities in the cardiac function of rats.

  16. Effect of diphenyl ether herbicides and oxadiazon on porphyrin biosynthesis in mouse liver, rat primary hepatocyte culture and HepG2 cells.

    Science.gov (United States)

    Krijt, J; van Holsteijn, I; Hassing, I; Vokurka, M; Blaauboer, B J

    1993-01-01

    The effects of the herbicides fomesafen, oxyfluorfen, oxadiazon and fluazifop-butyl on porphyrin accumulation in mouse liver, rat primary hepatocyte culture and HepG2 cells were investigated. Ten days of herbicide feeding (0.25% in the diet) increased the liver porphyrins in male C57B1/6J mice from 1.4 +/- 0.6 to 4.8 +/- 2.1 (fomesafen) 16.9 +2- 2.9 (oxyfluorfen) and 25.9 +/- 3.1 (oxadiazon) nmol/g wet weight, respectively. Fluazifop-butyl had no effect on liver porphyrin metabolism. Fomesafen, oxyfluorfen and oxadiazon increased the cellular porphyrin content of rat hepatocytes after 24 h of incubation (control, 3.2 pmol/mg protein, fomesafen, oxyfluorfen and oxadiazon at 0.125 mM concentration 51.5, 54.3 and 44.0 pmol/mg protein, respectively). The porphyrin content of HepG2 cells increased from 1.6 to 18.2, 10.6 and 9.2 pmol/mg protein after 24 h incubation with the three herbicides. Fluazifop-butyl increased hepatic cytochrome P450 levels and ethoxy- and pentoxyresorufin O-dealkylase (EROD and PROD) activity, oxyfluorfen increased PROD activity. Peroxisomal palmitoyl CoA oxidation increased after fomesafen and fluazifop treatment to about 500% of control values both in mouse liver and rat hepatocytes. Both rat hepatocytes and HepG2 cells can be used as a test system for the porphyrogenic potential of photobleaching herbicides.

  17. Overlapping but distinct specificities of anti-liver-kidney microsome antibodies in autoimmune hepatitis type II and hepatitis C revealed by recombinant native CYP2D6 and novel peptide epitopes

    Science.gov (United States)

    Klein, R; Zanger, U M; Berg, T; Hopf, U; Berg, P A

    1999-01-01

    Anti-liver-kidney microsome antibodies (anti-LKM) occur in autoimmune hepatitis (AIH) type II and in a subset of patients with hepatitis C. Anti-LKM1 in AIH are directed against cytochrome P4502D6 (CYP2D6), but conflicting data exist concerning the specificity of anti-LKM in hepatitis C. The aim of this study was to evaluate binding specificities of anti-LKM antibodies in both diseases using novel test antigens as well as their inhibitory capacity on CYP2D6 enzyme activity. Sera from 22 patients with AIH type II and 17 patients with hepatitis C being anti-LKM-positive in the immunofluorescence test were investigated for binding to native recombinant CYP2D6 and liver microsomes by ELISA and immunoblotting, and to synthetic peptides covering the region 254–339 (254–273, 257–269, 270–294, 291–310, 307–324, 321–339, 373–389) as well as the novel peptide 196–218 by ELISA. Furthermore, all sera were tested for inhibition of CYP2D6-dependent bufuralol 1′-hydroxylase activity. Twenty of the 22 AIH type II sera (91%) and nine of the 17 hepatitis C sera (53%) were positive for CYP2D6 by ELISA and/or immunoblotting. The previously described major peptide epitope comprising CYP2D6 amino acids 257–269 was recognized by 16 of the 22 AIH sera but by only one hepatitis C serum. A further epitope, 196–218, could be defined for the first time as another immunodominant epitope for AIH because it was recognized by 15 of the 22 AIH (68%) but only three of the 17 hepatitis C sera (18%). With the exception of the peptide 254–273, the other peptides showed no significant reactivity. Analysing the inhibitory properties of anti-LKM antibodies it emerged that 95% of AIH sera and 88% of hepatitis C sera inhibited enzyme function. These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257–269 a further immunodominant epitope exists on CYP2D6 which is recognized

  18. Changes induced by gamma radiation in microsomal membranes of storage of garlic

    International Nuclear Information System (INIS)

    Perez, M.B.; Croci, C.A.; Aveldano, M.I.

    2003-01-01

    This study evaluates the effects of the radio inhibition process on garlic bulbs in terms of phase properties of microsomal membranes and their lipid and fatty acid composition. Garlic bulbs were irradiated with an average dose of 60 Gy of 60 Co gamma rays 30-40 days after harvest. The treatment was carried out in the facilities of the National Atomic Energy Commission (CNEA). Rough and smooth microsomal membranes were isolated by ultracentrifugation from tissues of irradiated and non-irradiated storage leaves. Wide angle X-ray diffractograms of both fractions were recorded along 270 days of storage. Lipids were separated by thin layer chromatography. The fatty acid composition of major lipid fractions was studied by gas-liquid chromatography. The diffractograms featured peaks at Bragg spacing of 4.15 Armstrong and 3.75 Armstrong, revealing the presence of a gel (crystalline) phase, while the characteristic peak of the liquid-crystalline phase (4.6 Armstrong) was not observed in both sorts of membranes. Irradiation was found to bring about modifications in the intensity of 4.15 Armstrong and 3.75 Armstrong peaks from smooth microsomal membranes, but not in the behaviour along the studied period. Data from the rough microsomal fraction were erratic. Parallel to these changes, radiation induced significant modifications in the level of smooth microsomal membrane triacylglycerols in relation to phospholipids and their fatty acids. These findings indicate that the storage leaf tissues of garlic are radiosensitive both in terms of physical and chemical properties of their microsomal membranes. From the practical point of view, these results could be the basis for the development of techniques to be applied to storage garlic to evaluate if it was irradiated. (author)

  19. Inhibitory Effects of Aschantin on Cytochrome P450 and Uridine 5′-diphospho-glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Soon-Sang Kwon

    2016-04-01

    Full Text Available Aschantin is a bioactive neolignan found in Magnolia flos with antiplasmodial, Ca2+-antagonistic, platelet activating factor-antagonistic, and chemopreventive activities. We investigated its inhibitory effects on the activities of eight major human cytochrome P450 (CYP and uridine 5′-diphospho-glucuronosyltransferase (UGT enzymes of human liver microsomes to determine if mechanistic aschantin–enzyme interactions were evident. Aschantin potently inhibited CYP2C8-mediated amodiaquine N-de-ethylation, CYP2C9-mediated diclofenac 4′-hydroxylation, CYP2C19-mediated [S]-mephenytoin 4′-hydroxylation, and CYP3A4-mediated midazolam 1′-hydroxylation, with Ki values of 10.2, 3.7, 5.8, and 12.6 µM, respectively. Aschantin at 100 µM negligibly inhibited CYP1A2-mediated phenacetin O-de-ethylation, CYP2A6-mediated coumarin 7-hydroxylation, CYP2B6-mediated bupropion hydroxylation, and CYP2D6-mediated bufuralol 1′-hydroxylation. At 200 µM, it weakly inhibited UGT1A1-catalyzed SN-38 glucuronidation, UGT1A6-catalyzed N-acetylserotonin glucuronidation, and UGT1A9-catalyzed mycophenolic acid glucuronidation, with IC50 values of 131.7, 144.1, and 71.0 µM, respectively, but did not show inhibition against UGT1A3, UGT1A4, or UGT2B7 up to 200 µM. These in vitro results indicate that aschantin should be examined in terms of potential interactions with pharmacokinetic drugs in vivo. It exhibited potent mechanism-based inhibition of CYP2C8, CYP2C9, CYP2C19, and CYP3A4.

  20. Binding of Cimetidine to Balb/C Mouse Liver Catalase; Kinetics and Conformational Studies.

    Science.gov (United States)

    Jahangirvand, Mahboubeh; Minai-Tehrani, Dariush; Yazdi, Fatemeh; Minai-Tehrani, Arash; Razmi, Nematollah

    2016-01-01

    Catalase is responsible for converting hydrogen peroxide (H2O2) into water and oxygen in cells. This enzyme has high affinity for hydrogen peroxide and can protect the cells from oxidative stress damage. Catalase is a tetramer protein and each monomer contains a heme group. Cimetidine is a histamine H2 receptor blocker which inhibits acid release from stomach and is used for gasterointestinal diseases. In this research, effect of cimetidine on the activity of liver catalase was studied and the kinetic parameters of this enzyme and its conformational changes were investigated. Cell free extract of mouse liver was used for the catalase assay. The activity of the catalase was detected in the absence and presence of cimetidine by monitoring hydrogen peroxide reduction absorbance at 240 nm. The purified enzyme was used for conformational studies by Fluorescence spectrophotometry. The data showed that cimetidine could inhibit the enzyme in a non-competitive manner. Ki and IC50 values of the drug were determined to be about 0.75 and 0.85 uM, respectively. The Arrhenius plot showed that activation energy was 6.68 and 4.77 kJ/mol in the presence and absence of the drug, respectively. Fluorescence spectrophotometry revealed that the binding of cimetidine to the purified enzyme induced hyperchromicity and red shift which determined the conformational change on the enzyme. Cimetidine could non-competitively inhibit the liver catalase with high affinity. Binding of cimetidine to the enzyme induced conformational alteration in the enzyme.

  1. Soybean meal fermented by Aspergillus awamori increases the cytochrome P-450 content of the liver microsomes of mice.

    Science.gov (United States)

    Kishida, T; Ataki, H; Takebe, M; Ebihara, K

    2000-04-01

    The effect of soybean meal fermented by Aspergillus awamori on the acute lethality of acetaldehyde, pentobarbital sleeping time, and cytochrome P-450 content of the hepatic microsomes was studied in mice. Most of the daidzin and genistin in soybean meal (SBM) were converted into the respective aglycones, daidzein and genistein, by fermentation. In experiment 1, mice were fed isonitrogenic test diets with one of the following five protein sources for 28 d: casein, SBM, fermented and hot-air-dried SBM (FSBM-HD), fermented and freeze-dried SBM (FSBM-FD), or methanol-extracted FSBM-FD (FSMB-FD-R). The acute lethality of acetaldehyde in mice fed the FSBM-FD diet was significantly lower than that in mice fed the SBM, FSBM-HD, or FSBM-FD-R diet. In experiments 2 and 3, mice were fed isonitrogenic test diets with one of the following four protein sources for 28 d: casein, SBM, FSBM-FD, and FSBM-FD-R. The pentobarbital sleeping time was significantly shorter and the cytochrome P-450 content was significantly higher in the mice fed the FSBM-FD diet than the respective value in mice fed the other test diets. In experiment 4, mice were fed one of eight diets which contained different levels of aglycone obtained by varying the proportion of FSBM-FD and FSBM-FD-R, for 28 d. The cytochrome P-450 content in hepatic microsomes increased as the dietary level of isoflavonoid aglycones increased, but there was a saturation phenomenon. These results suggest that soy isoflavonoid aglycones are more potent inducers of cytochrome P-450 than isoflavonoid glycosides.

  2. Prediction of biotransformation products of the fungicide fluopyram by electrochemistry coupled online to liquid chromatography-mass spectrometry and comparison with in vitro microsomal assays.

    Science.gov (United States)

    Mekonnen, Tessema F; Panne, Ulrich; Koch, Matthias

    2018-04-01

    Biotransformation processes of fluopyram (FLP), a new succinate dehydrogenase inhibitor (SDHI) fungicide, were investigated by electrochemistry (EC) coupled online to liquid chromatography (LC) and electrospray mass spectrometry (ESI-MS). Oxidative phase I metabolite production was achieved using an electrochemical flow-through cell equipped with a boron-doped diamond (BDD) electrode. Structural elucidation and prediction of oxidative metabolism pathways were assured by retention time, isotopic patterns, fragmentation, and accurate mass measurements using EC/LC/MS, LC-MS/MS, and/or high-resolution mass spectrometry (HRMS). The results obtained by EC were compared with conventional in vitro studies by incubating FLP with rat and human liver microsomes (RLM, HLM). Known phase I metabolites of FLP (benzamide, benzoic acid, 7-hydroxyl, 8-hydroxyl, 7,8-dihydroxyl FLP, lactam FLP, pyridyl acetic acid, and Z/E-olefin FLP) were successfully simulated by EC/LC/MS. New metabolites including an imide, hydroxyl lactam, and 7-hydroxyl pyridyl acetic acid oxidative metabolites were predicted for the first time in our study using EC/LC/MS and liver microsomes. We found oxidation by dechlorination to be one of the major metabolism mechanisms of FLP. Thus, our results revealed that EC/LC/MS-based metabolic elucidation was more advantageous on time and cost of analysis and enabled matrix-free detection with valuable information about the mechanisms and intermediates of metabolism processes. Graphical abstract Oxidative metabolism of fluopyram.

  3. Hydrolysis of pyrethroids by human and rat tissues: Examination of intestinal, liver and serum carboxylesterases

    International Nuclear Information System (INIS)

    Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

    2007-01-01

    Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are ∼ 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts (∼ 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected

  4. Spaceflight Activates Lipotoxic Pathways in Mouse Liver.

    Directory of Open Access Journals (Sweden)

    Karen R Jonscher

    Full Text Available Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease.

  5. Spaceflight Activates Lipotoxic Pathways in Mouse Liver

    Science.gov (United States)

    Jonscher, Karen R.; Alfonso-Garcia, Alba; Suhalim, Jeffrey L.; Orlicky, David J.; Potma, Eric O.; Ferguson, Virginia L.; Bouxsein, Mary L.; Bateman, Ted A.; Stodieck, Louis S.; Levi, Moshe; Friedman, Jacob E.; Gridley, Daila S.; Pecaut, Michael J.

    2016-01-01

    Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease. PMID:27097220

  6. Metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, in mouse liver by alcohol dehydrogenase Adh1 and aldehyde reductase AKR1A4

    International Nuclear Information System (INIS)

    Short, Duncan M.; Lyon, Robert; Watson, David G.; Barski, Oleg A.; McGarvie, Gail; Ellis, Elizabeth M.

    2006-01-01

    The reductive metabolism of trans, trans-muconaldehyde, a cytotoxic metabolite of benzene, was studied in mouse liver. Using an HPLC-based stopped assay, the primary reduced metabolite was identified as 6-hydroxy-trans, trans-2,4-hexadienal (OH/CHO) and the secondary metabolite as 1,6-dihydroxy-trans, trans-2,4-hexadiene (OH/OH). The main enzymes responsible for the highest levels of reductase activity towards trans, trans-muconaldehyde were purified from mouse liver soluble fraction first by Q-sepharose chromatography followed by either blue or red dye affinity chromatography. In mouse liver, trans, trans-muconaldehyde is predominantly reduced by an NADH-dependent enzyme, which was identified as alcohol dehydrogenase (Adh1). Kinetic constants obtained for trans, trans-muconaldehyde with the native Adh1 enzyme showed a V max of 2141 ± 500 nmol/min/mg and a K m of 11 ± 4 μM. This enzyme was inhibited by pyrazole with a K I of 3.1 ± 0.57 μM. Other fractions were found to contain muconaldehyde reductase activity independent of Adh1, and one enzyme was identified as the NADPH-dependent aldehyde reductase AKR1A4. This showed a V max of 115 nmol/min/mg and a K m of 15 ± 2 μM and was not inhibited by pyrazole

  7. Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes.

    Science.gov (United States)

    Kot, Marta; Daniel, Władysława A

    2009-01-01

    The aim of the present study was to test the effect of diethyldithiocarbamate (DDC), which is regarded as a cytochrome P450 (CYP) CYP2A6 and CYP2E1 inhibitor, and ticlopidine, an efficient CYP2B6, CYP2C19 and CYP2D6 inhibitor, on the activity of human CYP1A2 and the metabolism of caffeine (1-N-, 3-N- and 7-N-demethylation, and C-8-hydroxylation). The experiment was carried out in vitro using human cDNA-expressed CYP1A2 (Supersomes) and human pooled liver microsomes. The effects of DDC and ticlopidine were compared to those of furafylline (a strong CYP1A2 inhibitor). A comparative in vitro study provides clear evidence that ticlopidine and DDC, applied at concentrations that inhibit the above-mentioned CYP isoforms, potently (as compared to furafylline) inhibit human CYP1A2 and caffeine metabolism, in particular 1-N- and 3-N-demethylation.

  8. Formation of DNA adducts in mouse tissues after 1-nitropyrene administration

    International Nuclear Information System (INIS)

    Mitchell, C.E.

    1986-01-01

    DNA adducts were isolated and characterized in mouse lung, liver and kidney after intratracheal instillation of [ 3 H]-1-nitropyrene (1-NP). HPLC analysis of the enzymatically digested DNA indicated the presence of multiple DNA adducts in mouse lung, liver and kidney. These results indicate that DNA adducts of 1-NP are formed in mouse lung, liver and kidney after intratracheal instillation of 1-NP; the HPLC profiles of the multiple adducts suggests that adducts may be formed via metabolic pathways that involve both nitroreduction and ring-oxidation. 6 references, 1 figure

  9. Oxidative stress-mediated mouse liver lesions caused by Clonorchis sinensis infection.

    Science.gov (United States)

    Maeng, Sejung; Lee, Hye Won; Bashir, Qudsia; Kim, Tae Im; Hong, Sung-Jong; Lee, Tae Jin; Sohn, Woon-Mok; Na, Byoung-Kuk; Kim, Tong-Soo; Pak, Jhang Ho

    2016-03-01

    Clonorchis sinensis is a high-risk pathogenic helminth that strongly provokes inflammation, epithelial hyperplasia, periductal fibrosis, and even cholangiocarcinoma in chronically infected individuals. Chronic inflammation is associated with an increased risk of various cancers due to the disruption of redox homeostasis. Accordingly, the present study was conducted to examine the time course relationship between histopathological changes and the appearance of oxidative stress markers, including lipid peroxidation, enzymes involved in lipid peroxidation, and mutagenic DNA adducts in the livers of mice infected with C. sinensis, as well as proinflammatory cytokines in infected mouse sera. Histopathological phenotypes such as bile duct epithelial hyperplasia, periductal fibrosis, edema and inflammatory infiltration increased in infected livers in a time-dependent manner. Intense immunoreactivity of lipid peroxidation products (4-hydroxy-2-nonenal; malondialdehyde), cyclooxygenase-2, 5-lipoxygenase and 8-oxo-7,8-dihydro-2'-deoxyguanosine were concomitantly observed in these injured regions. We also found elevated expressions of cyclooxygenase-2 and 5-lipoxygenase in C. sinensis excretory-secretory product-treated cholangiocarcinoma cells. Moreover, the levels of proinflammatory cytokines such as TNF-α, ILβ-1 and IL-6 were differentially upregulated in infected sera. With regard to oxidative stress-mediated carcinogenesis, our findings suggest that C. sinensis infestation may disrupt host redox homeostasis, creating a damaging environment that favors the development of advanced hepatobiliary diseases such as clonorchiasis-associated cholangiocarcinoma. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  10. Analyzing the temporal regulation of translation efficiency in mouse liver

    Directory of Open Access Journals (Sweden)

    Peggy Janich

    2016-06-01

    Full Text Available Mammalian physiology and behavior follow daily rhythms that are orchestrated by endogenous timekeepers known as circadian clocks. Rhythms in transcription are considered the main mechanism to engender rhythmic gene expression, but important roles for posttranscriptional mechanisms have recently emerged as well (reviewed in Lim and Allada (2013 [1]. We have recently reported on the use of ribosome profiling (RPF-seq, a method based on the high-throughput sequencing of ribosome protected mRNA fragments, to explore the temporal regulation of translation efficiency (Janich et al., 2015 [2]. Through the comparison of around-the-clock RPF-seq and matching RNA-seq data we were able to identify 150 genes, involved in ribosome biogenesis, iron metabolism and other pathways, whose rhythmicity is generated entirely at the level of protein synthesis. The temporal transcriptome and translatome data sets from this study have been deposited in NCBI's Gene Expression Omnibus under the accession number GSE67305. Here we provide additional information on the experimental setup and on important optimization steps pertaining to the ribosome profiling technique in mouse liver and to data analysis.

  11. Synthesis and evaluation of 4-[F-18]fluoro thalidomide for the in vivo studies of angiogenesis

    International Nuclear Information System (INIS)

    Kim, D. H.; Choi, Y. S.; Jeong, K. H.; Lee, K. H.; Choi, Y.; Kim, B. T.

    2005-01-01

    Thalidomide has been recently rediscovered for its possible utility as an antitumor agent, although it was marketed as a sedative in the 1950s and later found to be a potent teratogen. In this study, therefore, F-18 labeled thalidomide was synthesized and evaluated for the in vivo studies of angiogenesis. 4-[F-18]Fluoro thalidomide ([F-18]1) was prepared by labeling of 4-trimethylammonium thalidomide triflate with TBA[F-18]F in DMSO (90 .deg. C, 10 min) and purified by HPLC. The triflate salt was prepared from 3-fluoro phthalic anhydride in 3 steps. [F-18]1 was incubated with HUVEC cells at 37 .deg. C for 15, 30, 60, and 120 min, respectively. Dynamic PET images of [F-18]1 was obtained in mice implanted with LLC cells. In vitro metabolism study of [F-18]1 was carried out using mouse, rabbit, or human liver microsomes in the presence of NADPH, and the metabolites obtained from the mouse liver microsomal incubation of 1 were analyzed using LC-MS. Radiochemical yield of [F-18]1 was 50-60%, and the specific activity was 42-120 GBq/imol. The HUVEC cell uptake of [F-18]1 increased with time (100% at 15 min and 241% at 120 min). PET images showed that the radioactivity was accumulated in the liver, the kidneys and the bladder of the mice, and brain uptake was shown from 40 min postinjection. However, there was low level of radioactivity uptake in tumor. [F-18]1 was not metabolized by mouse, rabbit, or human liver microsomes but was hydrolyzed significantly at physiological pH. The hydrolyzed product was further analyzed by LC-MS, showing a mass peak corresponding to that of 4-fluoro-N-(o-carboxybenzoyl)glutamic acid imide. This result suggests that [F-18]1 is easily hydrolyzed at physiological pH and thus may not be suitable for the in vivo studies of tumor angiogenesis at least in rodents, although it was reported that the hydrolysis product of thalidomide may be responsible for its angiogenesis activity in humans

  12. The role of renal proximal tubule P450 enzymes in chloroform-induced nephrotoxicity: Utility of renal specific P450 reductase knockout mouse models

    International Nuclear Information System (INIS)

    Liu, Senyan; Yao, Yunyi; Lu, Shijun; Aldous, Kenneth; Ding, Xinxin; Mei, Changlin; Gu, Jun

    2013-01-01

    The kidney is a primary target for numerous toxic compounds. Cytochrome P450 enzymes (P450) are responsible for the metabolic activation of various chemical compounds, and in the kidney are predominantly expressed in proximal tubules. The aim of this study was to test the hypothesis that renal proximal tubular P450s are critical for nephrotoxicity caused by chemicals such as chloroform. We developed two new mouse models, one having proximal tubule-specific deletion of the cytochrome P450 reductase (Cpr) gene (the enzyme required for all microsomal P450 activities), designated proximal tubule-Cpr-null (PTCN), and the other having proximal tubule-specific rescue of CPR activity with the global suppression of CPR activity in all extra-proximal tubular tissues, designated extra-proximal tubule-Cpr-low (XPT-CL). The PTCN, XPT-CL, Cpr-low (CL), and wild-type (WT) mice were treated with a single oral dose of chloroform at 200 mg/kg. Blood, liver and kidney samples were obtained at 24 h after the treatment. Renal toxicity was assessed by measuring BUN and creatinine levels, and by pathological examination. The blood and tissue levels of chloroform were determined. The severity of toxicity was less in PTCN and CL mice, compared with that of WT and XPT-CL mice. There were no significant differences in chloroform levels in the blood, liver, or kidney, between PTCN and WT mice, or between XPT-CL and CL mice. These findings indicate that local P450-dependent activities play an important role in the nephrotoxicity induced by chloroform. Our results also demonstrate the usefulness of these novel mouse models for studies of chemical-induced kidney toxicity. - Highlights: • New mouse models were developed with varying P450 activities in the proximal tubule. • These mouse models were treated with chloroform, a nephrotoxicant. • Studies showed the importance of local P450s in chloroform-induced nephrotoxicity

  13. Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

    OpenAIRE

    Kukiełka, E; Cederbaum, A I

    1995-01-01

    Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid...

  14. Properties of the catalase molecule obtained from acatalasemic and hypocatalasemic mice Part I. Effects of denaturants on the catalase activity in the mouse liver

    OpenAIRE

    佐藤, 征紀

    1985-01-01

    Homogenates of mouse liver with isotonic sucrose solution were separated by the cell fractionation with repeating centrifugation. The supernatants were used for the inhibition test with the reagents such as 3,5 diiodosalicylic acid lithium salt (LIS), guanidine and azide, heat, acid and alkali. After various treatments, the remaining catalase activities were measured and showed as a relative enzyme activity. Stability of catalase in liver supernatants was compared normal (C3H/C(as)C(as)) and ...

  15. Cinnamon extract improves insulin sensitivity in the brain and lowers liver fat in mouse models of obesity.

    Science.gov (United States)

    Sartorius, Tina; Peter, Andreas; Schulz, Nadja; Drescher, Andrea; Bergheim, Ina; Machann, Jürgen; Schick, Fritz; Siegel-Axel, Dorothea; Schürmann, Annette; Weigert, Cora; Häring, Hans-Ulrich; Hennige, Anita M

    2014-01-01

    Treatment of diabetic subjects with cinnamon demonstrated an improvement in blood glucose concentrations and insulin sensitivity but the underlying mechanisms remained unclear. This work intends to elucidate the impact of cinnamon effects on the brain by using isolated astrocytes, and an obese and diabetic mouse model. Cinnamon components (eugenol, cinnamaldehyde) were added to astrocytes and liver cells to measure insulin signaling and glycogen synthesis. Ob/ob mice were supplemented with extract from cinnamomum zeylanicum for 6 weeks and cortical brain activity, locomotion and energy expenditure were evaluated. Insulin action was determined in brain and liver tissues. Treatment of primary astrocytes with eugenol promoted glycogen synthesis, whereas the effect of cinnamaldehyde was attenuated. In terms of brain function in vivo, cinnamon extract improved insulin sensitivity and brain activity in ob/ob mice, and the insulin-stimulated locomotor activity was improved. In addition, fasting blood glucose levels and glucose tolerance were greatly improved in ob/ob mice due to cinnamon extracts, while insulin secretion was unaltered. This corresponded with lower triglyceride and increased liver glycogen content and improved insulin action in liver tissues. In vitro, Fao cells exposed to cinnamon exhibited no change in insulin action. Together, cinnamon extract improved insulin action in the brain as well as brain activity and locomotion. This specific effect may represent an important central feature of cinnamon in improving insulin action in the brain, and mediates metabolic alterations in the periphery to decrease liver fat and improve glucose homeostasis.

  16. Subcellular distribution of styrene oxide in rat liver

    International Nuclear Information System (INIS)

    Pacifici, G.M.; Cuoci, L.; Rane, A.

    1984-01-01

    The subcellular distribution of ( 3 H)-styrene-7,8-oxide was studied in the rat liver. The compound was added to liver homogenate to give a final concentration of 2 X 10(-5); 2 X 10(-4) and 2 X 10(-3) M. Subcellular fractions were obtained by differential centrifugation. Most of styrene oxide (59-88%) was associated with the cytosolic fraction. Less than 15 percent of the compound was retrieved in each of the nuclear, mitochondrial and microsomal fractions. A considerable percentage of radioactivity was found unextractable with the organic solvents, suggesting that styrene oxide reacted with the endogenous compounds. The intracellular distribution of this epoxide was also studied in the perfused rat liver. Comparable results with those previously described were obtained. The binding of styrene oxide to the cytosolic protein was investigated by equilibrium dialysis and ultrafiltration. Only a small percentage of the compound was bound to protein

  17. Studies to further investigate the inhibition of human liver microsomal CYP2C8 by the acyl-β-glucuronide of gemfibrozil.

    Science.gov (United States)

    Jenkins, S M; Zvyaga, T; Johnson, S R; Hurley, J; Wagner, A; Burrell, R; Turley, W; Leet, J E; Philip, T; Rodrigues, A D

    2011-12-01

    In previous studies, gemfibrozil acyl-β-glucuronide, but not gemfibrozil, was found to be a mechanism-based inhibitor of cytochrome P450 2C8. To better understand whether this inhibition is specific for gemfibrozil acyl-β-glucuronide or whether other glucuronide conjugates are potential substrates for inhibition of this enzyme, we evaluated several pharmaceutical compounds (as their acyl glucuronides) as direct-acting and metabolism-dependent inhibitors of CYP2C8 in human liver microsomes. Of 11 compounds that were evaluated as their acyl glucuronide conjugates, only gemfibrozil acyl-β-glucuronide exhibited mechanism-based inhibition, indicating that CYP2C8 mechanism-based inhibition is very specific to certain glucuronide conjugates. Structural analogs of gemfibrozil were synthesized, and their glucuronide conjugates were prepared to further examine the mechanism of inhibition. When the aromatic methyl groups on the gemfibrozil moiety were substituted with trifluoromethyls, the resulting glucuronide conjugate was a weaker inhibitor of CYP2C8 and mechanism-based inhibition was abolished. However, the glucuronide conjugates of monomethyl gemfibrozil analogs were mechanism-based inhibitors of CYP2C8, although not as potent as gemfibrozil acyl-β-glucuronide itself. The ortho-monomethyl analog was a more potent inhibitor than the meta-monomethyl analog, indicating that CYP2C8 favors the ortho position for oxidation and potential inhibition. Molecular modeling of gemfibrozil acyl-β-glucuronide in the CYP2C8 active site is consistent with the ortho-methyl position being the favored site of covalent attachment to the heme. Moreover, hydrogen bonding to four residues (Ser100, Ser103, Gln214, and Asn217) is implicated.

  18. Modification of radiation-induced oxidative damage in liposomal and microsomal membrane by eugenol

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B.N. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Lathika, K.M. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, K.P. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)]. E-mail: kpm@magnum.barc.ernet.in

    2006-03-15

    Radiation-induced membrane oxidative damage, and their modification by eugenol, a natural antioxidant, was investigated in liposomes and microsomes. Liposomes prepared with DPH showed decrease in fluorescence after {gamma}-irradiation, which was prevented significantly by eugenol and correlated with magnitude of oxidation of phospholipids. Presence of eugenol resulted in substantial inhibition in MDA formation in irradiated liposomes/microsomes, which was less effective when added after irradiation. Similarly, the increase in phospholipase C activity observed after irradiation in microsomes was inhibited in samples pre-treated with eugenol. Results suggest association of radio- oxidative membrane damage with alterations in signaling molecules, and eugenol significantly prevented these membrane damaging events.

  19. Obese diet-induced mouse models of nonalcoholic steatohepatitis-tracking disease by liver biopsy

    Science.gov (United States)

    Kristiansen, Maria Nicoline Baandrup; Veidal, Sanne Skovgård; Rigbolt, Kristoffer Tobias Gustav; Tølbøl, Kirstine Sloth; Roth, Jonathan David; Jelsing, Jacob; Vrang, Niels; Feigh, Michael

    2016-01-01

    AIM: To characterize development of diet-induced nonalcoholic steatohepatitis (NASH) by performing liver biopsy in wild-type and genetically obese mice. METHODS: Male wild-type C57BL/6J (C57) mice (DIO-NASH) and male Lepob/Lepob (ob/ob) mice (ob/ob-NASH) were maintained on a diet high in trans-fat (40%), fructose (22%) and cholesterol (2%) for 26 and 12 wk, respectively. A normal chow diet served as control in C57 mice (lean chow) and ob/ob mice (ob/ob chow). After the diet-induction period, mice were liver biopsied and a blinded histological assessment of steatosis and fibrosis was conducted. Mice were then stratified into groups counterbalanced for steatosis score and fibrosis stage and continued on diet and to receive daily PO dosing of vehicle for 8 wk. Global gene expression in liver tissue was assessed by RNA sequencing and bioinformatics. Metabolic parameters, plasma liver enzymes and lipids (total cholesterol, triglycerides) as well as hepatic lipids and collagen content were measured by biochemical analysis. Non-alcoholic fatty liver disease activity score (NAS) (steatosis/inflammation/ballooning degeneration) and fibrosis were scored. Steatosis and fibrosis were also quantified using percent fractional area. RESULTS: Diet-induction for 26 and 12 wk in DIO-NASH and ob/ob-NASH mice, respectively, elicited progressive metabolic perturbations characterized by increased adiposity, total cholesterol and elevated plasma liver enzymes. The diet also induced clear histological features of NASH including hepatosteatosis and fibrosis. Overall, the metabolic NASH phenotype was more pronounced in ob/ob-NASH vs DIO-NASH mice. During the eight week repeated vehicle dosing period, the metabolic phenotype was sustained in DIO-NASH and ob/ob-NASH mice in conjunction with hepatomegaly and increased hepatic lipids and collagen accumulation. Histopathological scoring demonstrated significantly increased NAS of DIO-NASH mice (0 vs 4.7 ± 0.4, P NASH mice (2.4 ± 0.3 vs 6.3

  20. Effect of CAR activation on selected metabolic pathways in normal and hyperlipidemic mouse livers.

    Science.gov (United States)

    Rezen, Tadeja; Tamasi, Viola; Lövgren-Sandblom, Anita; Björkhem, Ingemar; Meyer, Urs A; Rozman, Damjana

    2009-08-19

    Detoxification in the liver involves activation of nuclear receptors, such as the constitutive androstane receptor (CAR), which regulate downstream genes of xenobiotic metabolism. Frequently, the metabolism of endobiotics is also modulated, resulting in potentially harmful effects. We therefore used 1,4-Bis [2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP) to study the effect of CAR activation on mouse hepatic transcriptome and lipid metabolome under conditions of diet-induced hyperlipidemia. Using gene expression profiling with a dedicated microarray, we show that xenobiotic metabolism, PPARalpha and adipocytokine signaling, and steroid synthesis are the pathways most affected by TCPOBOP in normal and hyperlipidemic mice. TCPOBOP-induced CAR activation prevented the increased hepatic and serum cholesterol caused by feeding mice a diet containing 1% cholesterol. We show that this is due to increased bile acid metabolism and up-regulated removal of LDL, even though TCPOBOP increased cholesterol synthesis under conditions of hyperlipidemia. Up-regulation of cholesterol synthesis was not accompanied by an increase in mature SREBP2 protein. As determined by studies in CAR -/- mice, up-regulation of cholesterol synthesis is however CAR-dependent; and no obvious CAR binding sites were detected in promoters of cholesterogenic genes. TCPOBOP also affected serum glucose and triglyceride levels and other metabolic processes in the liver, irrespective of the diet. Our data show that CAR activation modulates hepatic metabolism by lowering cholesterol and glucose levels, through effects on PPARalpha and adiponectin signaling pathways, and by compromising liver adaptations to hyperlipidemia.

  1. Sex-specific mouse liver gene expression: genome-wide analysis of developmental changes from pre-pubertal period to young adulthood

    Directory of Open Access Journals (Sweden)

    Conforto Tara L

    2012-04-01

    Full Text Available Abstract Background Early liver development and the transcriptional transitions during hepatogenesis are well characterized. However, gene expression changes during the late postnatal/pre-pubertal to young adulthood period are less well understood, especially with regards to sex-specific gene expression. Methods Microarray analysis of male and female mouse liver was carried out at 3, 4, and 8 wk of age to elucidate developmental changes in gene expression from the late postnatal/pre-pubertal period to young adulthood. Results A large number of sex-biased and sex-independent genes showed significant changes during this developmental period. Notably, sex-independent genes involved in cell cycle, chromosome condensation, and DNA replication were down regulated from 3 wk to 8 wk, while genes associated with metal ion binding, ion transport and kinase activity were up regulated. A majority of genes showing sex differential expression in adult liver did not display sex differences prior to puberty, at which time extensive changes in sex-specific gene expression were seen, primarily in males. Thus, in male liver, 76% of male-specific genes were up regulated and 47% of female-specific genes were down regulated from 3 to 8 wk of age, whereas in female liver 67% of sex-specific genes showed no significant change in expression. In both sexes, genes up regulated from 3 to 8 wk were significantly enriched (p p Ihh; female-specific Cdx4, Cux2, Tox, and Trim24 and may contribute to the developmental changes that lead to global acquisition of liver sex-specificity by 8 wk of age. Conclusions Overall, the observed changes in gene expression during postnatal liver development reflect the deceleration of liver growth and the induction of specialized liver functions, with widespread changes in sex-specific gene expression primarily occurring in male liver.

  2. Abetalipoproteinemia: A novel mutation of microsomal triglyceride ...

    African Journals Online (AJOL)

    Hager Barakizou

    2016-01-25

    Jan 25, 2016 ... Abetalipoproteinemia: A novel mutation of microsomal triglyceride transfer protein (MTP) gene in a young Tunisian patient. Hager Barakizou a,. *, Souha Gannouni a. , Khalil Messaoui a. , Mathilde Difilippo b. ,. Agne`s Sassolas b. , Fethi Bayoudh a a Department of Pediatrics, Military Hospital of Tunis, ...

  3. Postnatal liver growth and regeneration are independent of c-myc in a mouse model of conditional hepatic c-myc deletion

    Directory of Open Access Journals (Sweden)

    Sanders Jennifer A

    2012-03-01

    Full Text Available Abstract Background The transcription factor c-myc regulates genes involved in hepatocyte growth, proliferation, metabolism, and differentiation. It has also been assigned roles in liver development and regeneration. In previous studies, we made the unexpected observation that c-Myc protein levels were similar in proliferating fetal liver and quiescent adult liver with c-Myc displaying nucleolar localization in the latter. In order to investigate the functional role of c-Myc in adult liver, we have developed a hepatocyte-specific c-myc knockout mouse, c-mycfl/fl;Alb-Cre. Results Liver weight to body weight ratios were similar in control and c-myc deficient mice. Liver architecture was unaffected. Conditional c-myc deletion did not result in compensatory induction of other myc family members or in c-Myc's binding partner Max. Floxed c-myc did have a negative effect on Alb-Cre expression at 4 weeks of age. To explore this relationship further, we used the Rosa26 reporter line to assay Cre activity in the c-myc floxed mice. No significant difference in Alb-Cre activity was found between control and c-mycfl/fl mice. c-myc deficient mice were studied in a nonproliferative model of liver growth, fasting for 48 hr followed by a 24 hr refeeding period. Fasting resulted in a decrease in liver mass and liver protein, both of which recovered upon 24 h of refeeding in the c-mycfl/fl;Alb-Cre animals. There was also no effect of reducing c-myc on recovery of liver mass following 2/3 partial hepatectomy. Conclusions c-Myc appears to be dispensable for normal liver growth during the postnatal period, restoration of liver mass following partial hepatectomy and recovery from fasting.

  4. Nonstructural 5A Protein of Hepatitis C Virus Interferes with Toll-Like Receptor Signaling and Suppresses the Interferon Response in Mouse Liver.

    Directory of Open Access Journals (Sweden)

    Takeya Tsutsumi

    Full Text Available The hepatitis C virus nonstructural protein NS5A is involved in resistance to the host immune response, as well as the viral lifecycle such as replication and maturation. Here, we established transgenic mice expressing NS5A protein in the liver and examined innate immune responses against lipopolysaccharide (LPS in vivo. Intrahepatic gene expression levels of cytokines such as interleukin-6, tumor necrosis factor-α, and interferon-γ were significantly suppressed after LPS injection in the transgenic mouse liver. Induction of the C-C motif chemokine ligand 2, 4, and 5 was also suppressed. Phosphorylation of the signal transducer and activator of transcription 3, which is activated by cytokines, was also reduced, and expression levels of interferon-stimulated genes, 2'-5' oligoadenylate synthase, interferon-inducible double-stranded RNA-activated protein kinase, and myxovirus resistance 1 were similarly suppressed. Since LPS binds to toll-like receptor 4 and stimulates the downstream pathway leading to induction of these genes, we examined the extracellular signal-regulated kinase and IκB-α. The phosphorylation levels of these molecules were reduced in transgenic mouse liver, indicating that the pathway upstream of the molecules was disrupted by NS5A. Further analyses revealed that the interaction between interleukin-1 receptor-associated kinase-1 and tumor necrosis factor receptor associated factor-6 was dispersed in transgenic mice, suggesting that NS5A may interfere with this interaction via myeloid differentiation primary response gene 88, which was shown to interact with NS5A. Since the gut microbiota, a source of LPS, is known to be associated with pathological conditions in liver diseases, our results suggest the involvement of NS5A in the pathogenesis of HCV infected-liver via the suppression of innate immunity.

  5. Action of DTPA on hepatic plutonium. II. DTPA-induced removal of monomeric plutonium from mouse liver parenchymal cells

    International Nuclear Information System (INIS)

    Bhattacharyya, M.H.; Peterson, D.P.; Lindenbaum, A.

    1978-01-01

    Liver parenchymal cells were isolated 6 and 24 hr following the administration of diethylenetriaminepentaacetic acid (DTPA, 0.25 mmole/kg) to mice previously injected with 239 Pu-citrate (4.4 μCi/kg). Isolated parenchymal cells contained 440 dpm Pu/10 6 cells at 24 hr after Pu injection, just prior to DTPA administration. The PU content decreased to 330 dpm/10 6 cells at 6 hr and 140 dpm/10 6 cells at 24 hr after DTPA administration. Thus DTPA induced a striking decrease in the Pu content of isolated liver parenchymal cells. Parenchymal cells isolated from control mice not treated with DTPA changed little in Pu content from 24 to 48 hr after Pu injection. By 24 hr after DTPA treatment, the decrease in the Pu content of isolated liver parenchymal cells could account for the DTPA-induced release of Pu from the intact liver. Thus in the liver DTPA appears to act preferentially on the Pu associated with parenchymal cells. Liver parenchymal cells isolated 6 hr after DTPA administration and containing 330 dpm Pu/10 6 cells were incubated in vitro in the absence of added DTPA. After 18 hr of incubation the cells contained 130 dpm Pu/10 6 cells. This level corresponds to the level observed in cells isolated 24 hr after DTPA administration. Cells isolated from untreated mice lost only 15% of their Pu content during a similar in vitro incubation. Thus, by 6 hr after DTPA administration to the mouse, isolated liver parenchymal cells appeared to retain their ability to release Pu in vitro with no need for additional exposure to DTPA. The physiological significance of this finding is discussed

  6. The inward rectifier potassium channel Kir2.1 is expressed in mouse neutrophils from bone marrow and liver.

    Science.gov (United States)

    Masia, Ricard; Krause, Daniela S; Yellen, Gary

    2015-02-01

    Neutrophils are phagocytic cells that play a critical role in innate immunity by destroying bacterial pathogens. Channels belonging to the inward rectifier potassium channel subfamily 2 (Kir2 channels) have been described in other phagocytes (monocytes/macrophages and eosinophils) and in hematopoietic precursors of phagocytes. Their physiological function in these cells remains unclear, but some evidence suggests a role in growth factor-dependent proliferation and development. Expression of functional Kir2 channels has not been definitively demonstrated in mammalian neutrophils. Here, we show by RT-PCR that neutrophils from mouse bone marrow and liver express mRNA for the Kir2 subunit Kir2.1 but not for other subunits (Kir2.2, Kir2.3, and Kir2.4). In electrophysiological experiments, resting (unstimulated) neutrophils from mouse bone marrow and liver exhibit a constitutively active, external K(+)-dependent, strong inwardly rectifying current that constitutes the dominant current. The reversal potential is dependent on the external K(+) concentration in a Nernstian fashion, as expected for a K(+)-selective current. The current is not altered by changes in external or internal pH, and it is blocked by Ba(2+), Cs(+), and the Kir2-selective inhibitor ML133. The single-channel conductance is in agreement with previously reported values for Kir2.1 channels. These properties are characteristic of homomeric Kir2.1 channels. Current density in short-term cultures of bone marrow neutrophils is decreased in the absence of growth factors that are important for neutrophil proliferation [granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF)]. These results demonstrate that mouse neutrophils express functional Kir2.1 channels and suggest that these channels may be important for neutrophil function, possibly in a growth factor-dependent manner. Copyright © 2015 the American Physiological Society.

  7. Insulin receptors in the mammary gland

    International Nuclear Information System (INIS)

    Smith, D.H.

    1986-01-01

    Insulin binding studies were conducted using mammary membrane preparations to further the authors understanding of insulin's role in regulating mammary metabolism, particularly ruminant mammary metabolism. Specific objectives were to: (1) characterize insulin binding to bovine mammary microsomes and determine if the specificity and kinetics of binding indicate the presence of insulin receptors in bovine mammary gland; (2) examine and compare insulin binding by liver and mammary microsomes of the pig and dairy cow; (3) examine insulin binding to bovine milk fat globule membranes (MFGM) and evaluate this model's usefulness in assessing insulin receptor regulation in the mammary gland of the cow; (4) examine the effect of dietary fat in insulin binding by rat mammary and liver microsomes. The specificity and kinetics of 125 I-insulin binding of bovine mammary microsomes indicated the presence of insulin receptors in bovine mammary gland. Bovine liver and mammary microsomes specifically bound less 125 I-insulin than did the corresponding porcine microsomes, and mammary microsomes, regardless of species, specifically bound less 125 I-insulin than did liver microsomes. These differences in binding suggest differences in insulin responsiveness between pigs and cattle, as well as between the liver and mammary glands

  8. Genome-wide and phase-specific DNA-binding rhythms of BMAL1 control circadian output functions in mouse liver.

    Directory of Open Access Journals (Sweden)

    Guillaume Rey

    2011-02-01

    Full Text Available The mammalian circadian clock uses interlocked negative feedback loops in which the heterodimeric basic helix-loop-helix transcription factor BMAL1/CLOCK is a master regulator. While there is prominent control of liver functions by the circadian clock, the detailed links between circadian regulators and downstream targets are poorly known. Using chromatin immunoprecipitation combined with deep sequencing we obtained a time-resolved and genome-wide map of BMAL1 binding in mouse liver, which allowed us to identify over 2,000 binding sites, with peak binding narrowly centered around Zeitgeber time 6. Annotation of BMAL1 targets confirms carbohydrate and lipid metabolism as the major output of the circadian clock in mouse liver. Moreover, transcription regulators are largely overrepresented, several of which also exhibit circadian activity. Genes of the core circadian oscillator stand out as strongly bound, often at promoter and distal sites. Genomic sequence analysis of the sites identified E-boxes and tandem E1-E2 consensus elements. Electromobility shift assays showed that E1-E2 sites are bound by a dimer of BMAL1/CLOCK heterodimers with a spacing-dependent cooperative interaction, a finding that was further validated in transactivation assays. BMAL1 target genes showed cyclic mRNA expression profiles with a phase distribution centered at Zeitgeber time 10. Importantly, sites with E1-E2 elements showed tighter phases both in binding and mRNA accumulation. Finally, analyzing the temporal profiles of BMAL1 binding, precursor mRNA and mature mRNA levels showed how transcriptional and post-transcriptional regulation contribute differentially to circadian expression phase. Together, our analysis of a dynamic protein-DNA interactome uncovered how genes of the core circadian oscillator crosstalk and drive phase-specific circadian output programs in a complex tissue.

  9. The effect of trimethoprim on CYP2C8 mediated rosiglitazone metabolism in human liver microsomes and healthy subjects

    Science.gov (United States)

    Hruska, M W; Amico, J A; Langaee, T Y; Ferrell, R E; Fitzgerald, S M; Frye, R F

    2005-01-01

    Aims Rosiglitazone, a thiazolidinedione antidiabetic medication used in the treatment of Type 2 diabetes mellitus, is predominantly metabolized by the cytochrome P450 (CYP) enzyme CYP2C8. The anti-infective drug trimethoprim has been shown in vitro to be a selective inhibitor of CYP2C8. The purpose of this study was to evaluate the effect of trimethoprim on the CYP2C8 mediated metabolism of rosiglitazone in vivo and in vitro. Methods The effect of trimethoprim on the metabolism of rosiglitazone in vitro was assessed in pooled human liver microsomes. The effect in vivo was determined by evaluating rosiglitazone pharmacokinetics in the presence and absence of trimethoprim. Eight healthy subjects (four men and four women) completed a randomized, cross-over study. Subjects received single dose rosiglitazone (8 mg) in the presence and absence of trimethoprim 200 mg given twice daily for 5 days. Results Trimethoprim inhibited rosiglitazone metabolism both in vitro and in vivo. Inhibition of rosiglitazone para-hydroxylation by trimethoprim in vitro was found to be competitive with apparent Ki and IC50 values of 29 µm and 54.5 µm, respectively. In the presence of trimethoprim, rosiglitazone plasma AUC was increased by 31% (P = 0.01) from 2774 ± 645 µg l−1 h to 3643 ± 1051 µg l−1 h (95% confidence interval (Cl) for difference 189, 1549), and half-life was increased by 27% (P = 0.006) from 3.3 ± 0.5 to 4.2 ± 0.8 h (95% Cl for difference 0.36, 1.5). Trimethoprim reduced the para-O-sulphate rosiglitazone/rosiglitazone and the N-desmethylrosiglitazone/rosiglitazone AUC(0–24) ratios by 22% and 38%, respectively. Conclusions These results indicate that trimethoprim is a competitive inhibitor of CYP2C8-mediated rosiglitazone metabolism in vitro and that trimethoprim administration increases plasma rosiglitazone concentrations in healthy subjects. PMID:15606443

  10. Humanizing π-class glutathione S-transferase regulation in a mouse model alters liver toxicity in response to acetaminophen overdose.

    Directory of Open Access Journals (Sweden)

    Matthew P Vaughn

    Full Text Available Glutathione S-transferases (GSTs metabolize drugs and xenobiotics. Yet despite high protein sequence homology, expression of π-class GSTs, the most abundant of the enzymes, varies significantly between species. In mouse liver, hepatocytes exhibit high mGstp expression, while in human liver, hepatocytes contain little or no hGSTP1 mRNA or hGSTP1 protein. π-class GSTs are known to be critical determinants of liver responses to drugs and toxins: when treated with high doses of acetaminophen, mGstp1/2+/+ mice suffer marked liver damage, while mGstp1/2-/- mice escape liver injury.To more faithfully model the contribution of π-class GSTs to human liver toxicology, we introduced hGSTP1, with its exons, introns, and flanking sequences, into the germline of mice carrying disrupted mGstp genes. In the resultant hGSTP1+mGstp1/2-/- strain, π-class GSTs were regulated differently than in wild-type mice. In the liver, enzyme expression was restricted to bile duct cells, Kupffer cells, macrophages, and endothelial cells, reminiscent of human liver, while in the prostate, enzyme production was limited to basal epithelial cells, reminiscent of human prostate. The human patterns of hGSTP1 transgene regulation were accompanied by human patterns of DNA methylation, with bisulfite genomic sequencing revealing establishment of an unmethylated CpG island sequence encompassing the gene promoter. Unlike wild-type or mGstp1/2-/- mice, when hGSTP1+mGstp1/2-/- mice were overdosed with acetaminophen, liver tissues showed limited centrilobular necrosis, suggesting that π-class GSTs may be critical determinants of toxin-induced hepatocyte injury even when not expressed by hepatocytes.By recapitulating human π-class GST expression, hGSTP1+mGstp1/2-/- mice may better model human drug and xenobiotic toxicology.

  11. Subchronic effects of valproic acid on gene expression profiles for lipid metabolism in mouse liver

    International Nuclear Information System (INIS)

    Lee, Min-Ho; Kim, Mingoo; Lee, Byung-Hoon; Kim, Ju-Han; Kang, Kyung-Sun; Kim, Hyung-Lae; Yoon, Byung-Il; Chung, Heekyoung; Kong, Gu; Lee, Mi-Ock

    2008-01-01

    Valproic acid (VPA) is used clinically to treat epilepsy, however it induces hepatotoxicity such as microvesicular steatosis. Acute hepatotoxicity of VPA has been well documented by biochemical studies and microarray analysis, but little is known about the chronic effects of VPA in the liver. In the present investigation, we profiled gene expression patterns in the mouse liver after subchronic treatment with VPA. VPA was administered orally at a dose of 100 mg/kg/day or 500 mg/kg/day to ICR mice, and the livers were obtained after 1, 2, or 4 weeks. The activities of serum liver enzymes did not change, whereas triglyceride concentration increased significantly. Microarray analysis revealed that 1325 genes of a set of 32,996 individual genes were VPA responsive when examined by two-way ANOVA (P 1.5). Consistent with our previous results obtained using an acute VPA exposure model (Lee et al., Toxicol Appl Pharmacol. 220:45-59, 2007), the most significantly over-represented biological terms for these genes included lipid, fatty acid, and steroid metabolism. Biological pathway analysis suggests that the genes responsible for increased biosynthesis of cholesterol and triglyceride, and for decreased fatty acid β-oxidation contribute to the abnormalities in lipid metabolism induced by subchronic VPA treatment. A comparison of the VPA-responsive genes in the acute and subchronic models extracted 15 commonly altered genes, such as Cyp4a14 and Adpn, which may have predictive power to distinguish the mode of action of hepatotoxicants. Our data provide a better understanding of the molecular mechanisms of VPA-induced hepatotoxicity and useful information to predict steatogenic hepatotoxicity

  12. Bisphenol A sulfonation is impaired in metabolic and liver disease

    International Nuclear Information System (INIS)

    Yalcin, Emine B.; Kulkarni, Supriya R.; Slitt, Angela L.; King, Roberta

    2016-01-01

    Background: Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. Objectives: To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. Methods: The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. Results: In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Conclusion: Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. - Highlights: • Present study demonstrates that hepatic SULT 1A1/1A3 are primarily sulfonate BPA in mouse and human. • Hepatic BPA sulfonation is profoundly reduced steatosis, diabetes and cirrhosis. • With BPA-S detectable in urine under low or common exposures, these findings are novel and important.

  13. Bisphenol A sulfonation is impaired in metabolic and liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Yalcin, Emine B.; Kulkarni, Supriya R.; Slitt, Angela L., E-mail: angela_slitt@uri.edu; King, Roberta, E-mail: rking@uri.edu

    2016-02-01

    Background: Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. Objectives: To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. Methods: The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. Results: In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Conclusion: Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. - Highlights: • Present study demonstrates that hepatic SULT 1A1/1A3 are primarily sulfonate BPA in mouse and human. • Hepatic BPA sulfonation is profoundly reduced steatosis, diabetes and cirrhosis. • With BPA-S detectable in urine under low or common exposures, these findings are novel and important.

  14. Metabolism of polybrominated diphenyl ethers and tetrabromobisphenol A by fish liver subcellular fractions in vitro.

    Science.gov (United States)

    Shen, Mengnan; Cheng, Jie; Wu, Ruohan; Zhang, Shenghu; Mao, Liang; Gao, Shixiang

    2012-06-15

    Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are two major flame retardants that accumulate in fish tissues and are potentially toxic. Their debrominated and oxidated derivatives were also reported in fish tissues although the sources of theses derivatives were unidentified. Our study was to determine whether PBDEs and TBBPA could be metabolized by fish liver subcellular fractions in vitro and to identify what types of metabolites were formed. Liver microsomes and S9 fractions of crucian carp (Carassius auratus) were exposed to 4,4'-dibromodiphenyl ether (BDE 15), 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) or TBBPA solutions for 4h. Exposure of liver subcellular fractions to BDE 15 resulted in the formation of bromophenol and two monohydroxylated dibromodiphenyl ether metabolites. Neither in microsomes nor in S9 studies has revealed the presence of hydroxylated metabolites with BDE 47 exposure which indicated that the oxidation reactions in vitro were hindered by the increased number of bromine substituents on the PBDEs. TBBPA underwent an oxidative cleavage near the central carbon of the molecule, which led to the production of 2,6-dibromo-4-isopropyl-phenol and three unidentified metabolites. Another metabolite of TBBPA characterized as a hexa-brominated compound with three aromatic rings was also found in the liver subcellular fractions. These results suggest that the biotransformation of BDE 15 and TBBPA in fish liver is mediated by cytochrome P450 (CYP450) enzymes, as revealed by the formation of hydroxylated metabolites and oxidative bond cleavage products. Moreover, further studies on the identification of specific CYP450 isozymes involved in the biotransformation revealed that CYP1A was the major enzyme responsible for the biotransformation of BDE 15 and TBBPA in fish liver subcellular fractions and CYP3A4 also played a major role in metabolism of TBBPA. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Metabolites of 5F-AKB-48, a synthetic cannabinoid receptor agonist, identified in human urine and liver microsomal preparations using liquid chromatography high-resolution mass spectrometry.

    Science.gov (United States)

    Holm, Niels Bjerre; Pedersen, Anders Just; Dalsgaard, Petur Weihe; Linnet, Kristian

    2015-03-01

    New types of synthetic cannabinoid designer drugs are constantly introduced to the illicit drug market to circumvent legislation. Recently, N-​(1-Adamant​yl)-​1-​(5-​fluoropentyl)-​1H-​indazole-​3-​carboxamide (5F-AKB-48), also known as 5F-APINACA, was identified as an adulterant in herbal products. This compound deviates from earlier JHW-type synthetic cannabinoids by having an indazole ring connected to an adamantyl group via a carboxamide linkage. Synthetic cannabinoids are completely metabolized, and identification of the metabolites is thus crucial when using urine as the sample matrix. Using an authentic urine sample and high-resolution accurate-mass Fourier transform Orbitrap mass spectrometry, we identified 16 phase-I metabolites of 5F-AKB-48. The modifications included mono-, di-, and trihydroxylation on the adamantyl ring alone or in combination with hydroxylation on the N-fluoropentylindazole moiety, dealkylation of the N-fluoropentyl side chain, and oxidative loss of fluorine as well as combinations thereof. The results were compared to human liver microsomal (HLM) incubations, which predominantly showed time-dependent formation of mono-, di-, and trihydroxylated metabolites having the hydroxyl groups on the adamantyl ring. The results presented here may be used to select metabolites specific of 5F-AKB-48 for use in clinical and forensic screening. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Multiple viral/self immunological cross-reactivity in liver kidney microsomal antibody positive hepatitis C virus infected patients is associated with the possession of HLA B51.

    Science.gov (United States)

    Bogdanos, D-P; Lenzi, M; Okamoto, M; Rigopoulou, E I; Muratori, P; Ma, Y; Muratori, L; Tsantoulas, D; Mieli- Vergani, G; Bianchi, F B; Vergani, D

    2004-01-01

    Liver Kidney Microsomal autoantibody type 1(LKM1) directed to cytochrome P4502D6 (CYP2D6) characterises autoimmune hepatitis type-2 (AIH-2), but is also found in a proportion of chronic hepatitis C virus (HCV) infected patients, CYP2D6252-271 being a major B- cell autoepitope. Molecular mimicry and immunological cross-reactivity between CYP2D6252-271, HCV polyprotein and the infected cell protein 4 (ICP4) of herpes simplex virus type 1 (HSV-1) have been suggested as triggers for the induction of LKM1, but reactivity and cross-reactivity to the relevant sequences have not been investigated experimentally. CYP2D6252-271 and its viral homologues were constructed and tested by ELISA in the sera of 46 chronically infected HCV patients, 23 of whom were LKM1 positive. Reactivity to the E1 HCV and ICP4 HSV1 mimics was frequently found in HCV infected patients irrespectively of their LKM1 status; viral/self cross-reactivity (as indicated by inhibition studies), however, was present in the only 2 of the 23 LKM1 seropositive HCV patients, who possessed the HLA allotype B51. Our results indicate that in HCV infected patients virus/self cross-reactivity is dependent on a specific immunogenetic background, a finding awaiting confirmation by studies in larger series of patients.

  17. [Detection and the production mechanism of antinuclear antibodies (ANA) and anti-liver/kidney microsomal tpe 1 antibodies (anti-LKM1) in patients with chronic hepatitis C].

    Science.gov (United States)

    Bai, Li; Lu, Hai-Ying; Feng, Zhen-Ru; Yu, Min; Li, Wen-Gang; Gong, Wei-Bo; Zhao, Nu-en-ji-ya; Xu, Xiao-Yuan

    2009-08-01

    To investigate the prevalence of antinuclear antibodies (ANA) and anti-liver/ kidney microsomal type 1 antibodies (anti-LKM1) in patients with chronic hepatitis C (CHC)and to explore the mechanism of production of these autoantibodies. Serum samples were collected from 360 patients with CHC (case group), 69 patients with chronic hepatitis B (CHB) and 69 patients with autoimmune hepatitis (AIH) (control group). Serum ANA and anti-LKM1 were detected by indirect immunofluorescence (HF) technique and enzyme-linked immunosorbent assay (ELISA), respectively. Multi-factor analysis was performed to explore the correlations of the production of autoantibodies with some factors such as age, sex, viral loads, HCV genotype, biochemical parameters and clinical characteristics. Fifty-four (15%) of 360 patients infected with HCV were positive in autoantibodies. The prevalence of ANA and anti-LKM1 were 12.5% (45/360) and 2.5% (9/ 360), respectively. The positive rate of autoantibodies in patients with CHC was significantly higher than that in patients with CHB (15% vs 2.9%, P = 0.006), but significantly lower than that in patients with AIH (15% vs 47.9%, P 0.05). Autoantibodies related to AIH can be detected in CHC patients; interferon may not induce the production of autoantibodies; it is very likely that HCV infection induces the autoimmune reaction and the production of autoantibodies.

  18. Dietary Broccoli Lessens Development of Fatty Liver and Liver Cancer in Mice Given Diethylnitrosamine and Fed a Western or Control Diet.

    Science.gov (United States)

    Chen, Yung-Ju; Wallig, Matthew A; Jeffery, Elizabeth H

    2016-03-01

    The high-fat and high-sugar Westernized diet that is popular worldwide is associated with increased body fat accumulation, which has been related to the development of nonalcoholic fatty liver disease (NAFLD). Without treatment, NAFLD may progress to hepatocellular carcinoma (HCC), a cancer with a high mortality rate. The consumption of broccoli in the United States has greatly increased in the last 2 decades. Epidemiologic studies show that incorporating brassica vegetables into the daily diet lowers the risk of several cancers, although, to our knowledge, this is the first study to evaluate HCC prevention through dietary broccoli. We aimed to determine the impact of dietary broccoli on hepatic lipid metabolism and the progression of NAFLD to HCC. Our hypothesis was that broccoli decreases both hepatic lipidosis and the development of HCC in a mouse model of Western diet-enhanced liver cancer. Adult 5-wk-old male B6C3F1 mice received a control diet (AIN-93M) or a Western diet (high in lard and sucrose, 19% and 31%, wt:wt, respectively), with or without freeze-dried broccoli (10%, wt:wt). Starting the following week, mice were treated once per week with diethylnitrosamine (DEN; 45 mg/kg body weight intraperitoneally at ages 6, 7, 8, 10, 11, and 12 wk). Hepatic gene expression, lipidosis, and tumor outcomes were analyzed 6 mo later, when mice were 9 mo old. Mice receiving broccoli exhibited lower hepatic triglycerides (P broccoli feeding (P = 0.006), whereas microsomal triglyceride transfer protein was upregulated (P = 0.045), supporting the finding that dietary broccoli decreased hepatic triglycerides. Long-term consumption of whole broccoli countered both NAFLD development enhanced by a Western diet and hepatic tumorigenesis induced by DEN in male B6C3F1 mice. © 2016 American Society for Nutrition.

  19. Morphological Lesions in Mouse Liver and Lungs After Lung Exposure to Carbon Nanotubes

    DEFF Research Database (Denmark)

    Szarek, J.; Mortensen, Alicja; Jackson, P.

    2013-01-01

    Introduction: Engineered nanoparticles are smaller than 100 nm in at least one direction and designed to improve or achieve new physicochemical properties. Consequently, toxicological properties may also change. Carbon nanotubes have attracted industrial interest due to their unique properties....... Materials and Methods: One day before mating, 30 mice (C57BL/6BomTac, Taconic Europe, Denmark) were given 67 μg multi-walled carbon nanotubes (NM-400, Nanocyl, Belgium) intratracheally (group A). A further 30 control mice (group B) received vehicle (Millipore water with 2% mouse serum). Lungs and liver were...... taken from six animals from each group for histopathological examination (haematoxylin and eosin staining) 6 weeks (A1, B1 group) and 4 months (A2, B2) after exposure. Results: Lungs in A1 mice showed bronchiolar subepithelial oedema and perivascular oedema and sporadic hyperaemia and the presence...

  20. Molecular Pathogenesis of Liver Steatosis Induced by Hepatitis C Virus

    Directory of Open Access Journals (Sweden)

    Cheng Jun

    2012-09-01

    Full Text Available Liver steatosis is a pathological hallmark in patients with chronic hepatitis C (CHC. Increased lipid uptake, decreased lipid secretion, increased lipid synthesis and decreased lipid degradation are all involved in pathogenesis of steatosis induced by hepatitic C virus (HCV infection. Level of low density lipoprotein receptor (LDL-R and activity of peroxisome proliferator-activated receptor (PPAR α is related to liver uptake of lipid from circulation, and affected by HCV. Secretion via microsomal triglyceride transfer protein (MTTP, and formation of very low density lipoprotein (VLDL have been hampered by HCV infection. Up-regulation of lipid synthesis related genes, such as sterol regulatory element-binding protein (SREBP-1, SREBP-2, SREBP-1c, fatty acid synthase (FASN, HMG CoA reductase (HMGCR, liver X receptor (LXR, acetyl-CoA carboxylase 1 (ACC1, hepatic CB (1 receptors, retinoid X receptor (RXR α, were the main stay of liver steatosis pathogenesis. Degradation of lipid in liver is decreased in patients with CHC. There is strong evidence that heterogeneity of HCV core genes of different genotypes affect their effects of liver steatosis induction. A mechanism in which steatosis is involved in HCV life cycle is emerging.

  1. The interaction of representative members from two classes of antimycotics--the azoles and the allylamines--with cytochromes P-450 in steroidogenic tissues and liver.

    Science.gov (United States)

    Schuster, I

    1985-06-01

    Spectrophotometric studies with ketoconazole, clotrimazole and miconazole show strong type-II interactions with several cytochromes P-450, particularly (Ks greater than 10(7)M-1; pH7.4; 25 degrees C) with the 11 beta-hydroxylase of adrenal mitochondria, with the 17 alpha/20 lyase of testis microsomes and with some forms of cytochromes P-450 of liver. A tight binding of the azoles also occurs to the reduced cytochromes, giving rise to an impeded CO binding to the haem iron. The binding of the azoles to 11 beta-hydroxylase and 17 alpha/20 lyase is much tighter than the binding of endogenous substrates, and consequently inhibition of steroidogenesis will occur at these sites. The metabolism of xenobiotic substrates by the cytochromes P-450 of liver will also be severely impeded. In contrast, the allylamines naftifine and SF 86-327 are type-I substrates for a small portion of cytochromes P-450 of liver microsomes only and there is no spectral evidence for binding to the cytochromes P-450 involved in steroid biosynthesis.

  2. Exogenous iron and γ-irradiation induce NO-synthase synthesis in mouse liver

    International Nuclear Information System (INIS)

    Mikoyan, V.D.; Voevodskaya, N.V.; Kubrina, L.N.; Malenkova, I.V.; Vanin, A.F.

    1994-01-01

    Protein synthesis inhibitor (cycloheximide, CHI) and exogenous antioxidant (phenazan) suppress the synthesis of NO in mouse liver in vivo which is induced by administration to the animals of γ-irradiation, bacterial lipopolysaccharide (LPS), or Fe 2+ -citrate together with LPS. Biosynthesis of NO was monitored by the ESR signal of paramagnetic mononitrosyl iron complexes with the exogenous ligand diethyldithiocarbamate (MNIC-DETC) 30 min after addition of the ligand. The complexes arise from NO binding to DETC complexes with exogenous and endogenous Fe 2+ , which act as selective NO traps. The enhancement of NO biosynthesis after γ-irradiation or LPS or LPS + Fe 2+ -citrate is apparently due to the induction of the synthesis of NO-synthase, which is inhibited by cycloheximide. This process is triggered by reactive oxygen species, presumably through the activation of the transcription factor protein NFkB. The accumulation of free radical oxygen species is inhibited by the antioxidant phenazan

  3. A comparative study of precision cut liver slices, hepatocytes, and liver microsomes from the Wistar rat using metronidazole as a model substance

    DEFF Research Database (Denmark)

    Sidelmann, U. G.; Cornett, Claus; Tjornelund, J.

    1996-01-01

    1. Metronidazole is metabolized by rat liver in vitro models to form a hydroxy metabolite, an acetic acid metabolite, a glucuronic acid conjugate, and a sulphate conjugate. 2. Four different in vitro systems for investigation of drug metabolism based on liver preparations from the male Wistar rat...

  4. Lactobacillus rhamnosus CCFM1107 treatment ameliorates alcohol-induced liver injury in a mouse model of chronic alcohol feeding.

    Science.gov (United States)

    Tian, Fengwei; Chi, Feifei; Wang, Gang; Liu, Xiaoming; Zhang, Qiuxiang; Chen, Yongquan; Zhang, Hao; Chen, Wei

    2015-12-01

    Lactobacillus rhamnosus CCFM1107 was screened for high antioxidative activity from 55 lactobacilli. The present study attempted to explore the protective properties of L. rhamnosus CCFM1107 in alcoholic liver injury. A mouse model was induced by orally feeding alcohol when simultaneously treated with L. rhamnosus CCFM1107, the drug Hu-Gan- Pian (HGP), L. rhamnosus GG (LGG), and L. plantarum CCFM1112 for 3 months. Biochemical analysis was performed for both serum and liver homogenate. Detailed intestinal flora and histological analyses were also carried out. Our results indicated that the administration of L. rhamnosus CCFM1107 significantly inhibited the increase in the levels of serum aminotransferase and endotoxin, as well as the levels of triglyceride (TG) and cholesterol (CHO) in the serum and in the liver. Glutathione (GSH), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were elevated while the levels of malondialdehyde (MDA) were decreased. The enteric dysbiosis caused by alcohol was restored by increasing the numbers of both lactobacilli and bifidobacteria and decreasing the numbers of both enterococci and enterobacter. Histological analysis confirmed the protective effect of L. rhamnosus CCFM1107. Compared with the other lactobacilli and to the drug Hu-Gan-Pian, there is a high chance that L. rhamnosus CCFM1107 provides protective effects on alcoholic liver injury by reducing oxidative stress and restoring the intestinal flora.

  5. Trichloroethylene-induced gene expression and DNA methylation changes in B6C3F1 mouse liver.

    Directory of Open Access Journals (Sweden)

    Yan Jiang

    Full Text Available Trichloroethylene (TCE, widely used as an organic solvent in the industry, is a common contaminant in air, soil, and water. Chronic TCE exposure induced hepatocellular carcinoma in mice, and occupational exposure in humans was suggested to be associated with liver cancer. To understand the role of non-genotoxic mechanism(s for TCE action, we examined the gene expression and DNA methylation changes in the liver of B6C3F1 mice orally administered with TCE (0, 100, 500 and 1000 mg/kg b.w. per day for 5 days. After 5 days TCE treatment at a dose level of 1000 mg/kg b.w., a total of 431 differentially expressed genes were identified in mouse liver by microarray, of which 291 were up-regulated and 140 down-regulated. The expression changed genes were involved in key signal pathways including PPAR, proliferation, apoptosis and homologous recombination. Notably, the expression level of a number of vital genes involved in the regulation of DNA methylation, such as Utrf1, Tet2, DNMT1, DNMT3a and DNMT3b, were dysregulated. Although global DNA methylation change was not detected in the liver of mice exposed to TCE, the promoter regions of Cdkn1a and Ihh were found to be hypo- and hypermethylated respectively, which correlated negatively with their mRNA expression changes. Furthermore, the gene expression and DNA methylation changes induced by TCE were dose dependent. The overall data indicate that TCE exposure leads to aberrant DNA methylation changes, which might alter the expression of genes involved in the TCE-induced liver tumorgenesis.

  6. DNA damage in mouse and rat liver by caprolactam and benzoin, evaluated with three different methods.

    Science.gov (United States)

    Parodi, S; Abelmoschi, M L; Balbi, C; De Angeli, M T; Pala, M; Russo, P; Taningher, M; Santi, L

    1989-11-01

    Benzoin and caprolactam were examined for their capability of inducing alkaline DNA fragmentation in mouse and rat liver DNA after treatment in vivo. Three different methods were used. With the alkaline elution technique we measured an effect presumably related to the conformation of the DNA coil. With a viscometric and a fluorometric unwinding method we measured an effect presumably related to the number of unwinding points in DNA. For both compounds only the alkaline elution technique was clearly positive. The results suggest that both caprolactam and benzoin can induce an important change in the conformation of the DNA coil without inducing true breaks in DNA.

  7. The in vitro NADPH-dependent inhibition by CCl4 of the ATP-dependent calcium uptake of hepatic microsomes from male rats. Studies on the mechanism of the inactivation of the hepatic microsomal calcium pump by the CCl3 radical

    International Nuclear Information System (INIS)

    Srivastava, S.P.; Chen, N.Q.; Holtzman, J.L.

    1990-01-01

    The hepatotoxicity of CCl4 is mediated through its initial reduction by cytochrome P-450 to the CCl3 radical. This radical then damages important metabolic systems such as the ATP-dependent microsomal Ca2+ pump. Previous studies from our laboratory on isolated microsomes have shown that NADPH in the absence of toxic agents inhibits this pump. We have now found in in vitro incubations that CCl4 (0.5-2.5 mM) enhanced the NADPH-dependent inhibition of Ca2+ uptake from 28% without CCl4 to a maximum of 68%. These concentrations are in the range found in the livers and blood of lethally intoxicated animals and are toxic to cultured hepatocytes. The inhibition of Ca2+ uptake was due both to a decrease in the Ca2(+)-dependent ATPase and to an enhanced release of Ca2+ from the microsomes. The NADPH-dependent CCl4 inhibition was greater under N2 and was totally prevented by CO. GSH (1-10 mM) added during the incubation with CCl4 prevented the inhibition. This protection was also seen when the incubations were performed under nitrogen. When samples were preincubated with CCl4, the CCl4 metabolism was stopped, and then the Ca2+ uptake was determined; GSH reversed the CCl4 inhibition of Ca2+ uptake. This reversal showed saturation kinetics for GSH with two Km values of 0.315 and 93 microM when both the preincubation and the Ca2+ uptake were performed under air, and 0.512 and 31 microM when both were performed under nitrogen. Cysteine did not prevent the NADPH-dependent CCl4 inhibition of Ca2+ uptake. CCl4 increased lipid peroxidation in air, but no lipid peroxidation was seen under nitrogen. Lipid peroxidation was only modestly reversed by GSH. GSH did not remove 14C bound to samples preincubated with the 14CCl4

  8. Cardiac expression of microsomal triglyceride transfer protein is increased in obesity and serves to attenuate cardiac triglyceride accumulation

    DEFF Research Database (Denmark)

    Bartels, Emil D; Nielsen, Jan M; Hellgren, Lars I

    2009-01-01

    Obesity causes lipid accumulation in the heart and may lead to lipotoxic heart disease. Traditionally, the size of the cardiac triglyceride pool is thought to reflect the balance between uptake and beta-oxidation of fatty acids. However, triglycerides can also be exported from cardiomyocytes via...... secretion of apolipoproteinB-containing (apoB) lipoproteins. Lipoprotein formation depends on expression of microsomal triglyceride transfer protein (MTP); the mouse expresses two isoforms of MTP, A and B. Since many aspects of the link between obesity-induced cardiac disease and cardiac lipid metabolism...... remain unknown, we investigated how cardiac lipoprotein synthesis affects cardiac expression of triglyceride metabolism-controlling genes, insulin sensitivity, and function in obese mice. Heart-specific ablation of MTP-A in mice using Cre-loxP technology impaired upregulation of MTP expression...

  9. A balanced diet is necessary for proper entrainment signals of the mouse liver clock.

    Directory of Open Access Journals (Sweden)

    Akiko Hirao

    Full Text Available BACKGROUND: The peripheral circadian clock in mice is entrained not only by light-dark cycles but also by daily restricted feeding schedules. Behavioral and cell culture experiments suggest an increase in glucose level as a factor in such feeding-induced entrainment. For application of feeding-induced entrainment in humans, nutrient content and dietary variations should be considered. PRINCIPAL FINDING: To elucidate the food composition necessary for dietary entrainment, we examined whether complete or partial substitution of dietary nutrients affected phase shifts in liver clocks of mice. Compared with fasting mice or ad libitum fed mice, the liver bioluminescence rhythm advanced by 3-4 h on the middle day in Per2::luciferase knock-in mice that were administered a standard mouse diet, i.e. AIN-93M formula [0.6-0.85 g/10 g mouse BW] (composition: 14% casein, 47% cornstarch, 15% gelatinized cornstarch, 10% sugar, 4% soybean oil, and 10% other [fiber, vitamins, minerals, etc.], for 2 days. When each nutrient was tested alone (100% nutrient, an insignificant weak phase advance was found to be induced by cornstarch and soybean oil, but almost no phase advance was induced by gelatinized cornstarch, high-amylose cornstarch, glucose, sucrose, or casein. A combination of glucose and casein without oil, vitamin, or fiber caused a significant phase advance. When cornstarch in AIN-93M was substituted with glucose, sucrose, fructose, polydextrose, high-amylose cornstarch, or gelatinized cornstarch, the amplitude of phase advance paralleled the increase in blood glucose concentration. CONCLUSIONS: Our results strongly suggest the following: (1 balanced diets containing carbohydrates/sugars and proteins are good for restricted feeding-induced entrainment of the peripheral circadian clock and (2 a balanced diet that increases blood glucose, but not by sugar alone, is suitable for entrainment. These findings may assist in the development of dietary

  10. Identification of AKB-48 and 5F-AKB-48 Metabolites in Authentic Human Urine Samples Using Human Liver Microsomes and Time of Flight Mass Spectrometry.

    Science.gov (United States)

    Vikingsson, Svante; Josefsson, Martin; Gréen, Henrik

    2015-01-01

    The occurrence of structurally related synthetic cannabinoids makes the identification of unique markers of drug intake particularly challenging. The aim of this study was to identify unique and abundant metabolites of AKB-48 and 5F-AKB-48 for toxicological screening in urine. Investigations of authentic urine samples from forensic cases in combination with human liver microsome (HLM) experiments were used for identification of metabolites. HLM incubations of AKB-48 and 5F-AKB-48 along with 35 urine samples from authentic cases were analyzed with liquid chromatography quadrupole tandem time of flight mass spectrometry. Using HLMs 41 metabolites of AKB-48 and 37 metabolites of 5F-AKB-48 were identified, principally represented by hydroxylation but also ketone formation and dealkylation. Monohydroxylated metabolites were replaced by di- and trihydroxylated metabolites within 30 min. The metabolites from the HLM incubations accounted for on average 84% (range, 67-100) and 91% (range, 71-100) of the combined area in the case samples for AKB-48 and 5F-AKB-48, respectively. While defluorinated metabolites accounted for on average 74% of the combined area after a 5F-AKB-48 intake only a few identified metabolites were shared between AKB-48 and 5F-AKB-48, illustrating the need for a systematic approach to identify unique metabolites. HLMs in combination with case samples seem suitable for this purpose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Dietary Broccoli Lessens Development of Fatty Liver and Liver Cancer in Mice Given Diethylnitrosamine and Fed a Western or Control Diet123

    Science.gov (United States)

    Chen, Yung-Ju; Wallig, Matthew A; Jeffery, Elizabeth H

    2016-01-01

    Background: The high-fat and high-sugar Westernized diet that is popular worldwide is associated with increased body fat accumulation, which has been related to the development of nonalcoholic fatty liver disease (NAFLD). Without treatment, NAFLD may progress to hepatocellular carcinoma (HCC), a cancer with a high mortality rate. The consumption of broccoli in the United States has greatly increased in the last 2 decades. Epidemiologic studies show that incorporating brassica vegetables into the daily diet lowers the risk of several cancers, although, to our knowledge, this is the first study to evaluate HCC prevention through dietary broccoli. Objective: We aimed to determine the impact of dietary broccoli on hepatic lipid metabolism and the progression of NAFLD to HCC. Our hypothesis was that broccoli decreases both hepatic lipidosis and the development of HCC in a mouse model of Western diet–enhanced liver cancer. Methods: Adult 5-wk-old male B6C3F1 mice received a control diet (AIN-93M) or a Western diet (high in lard and sucrose, 19% and 31%, wt:wt, respectively), with or without freeze-dried broccoli (10%, wt:wt). Starting the following week, mice were treated once per week with diethylnitrosamine (DEN; 45 mg/kg body weight intraperitoneally at ages 6, 7, 8, 10, 11, and 12 wk). Hepatic gene expression, lipidosis, and tumor outcomes were analyzed 6 mo later, when mice were 9 mo old. Results: Mice receiving broccoli exhibited lower hepatic triglycerides (P broccoli feeding (P = 0.006), whereas microsomal triglyceride transfer protein was upregulated (P = 0.045), supporting the finding that dietary broccoli decreased hepatic triglycerides. Conclusion: Long-term consumption of whole broccoli countered both NAFLD development enhanced by a Western diet and hepatic tumorigenesis induced by DEN in male B6C3F1 mice. PMID:26865652

  12. Effects of Liver Fibrosis Progression on Tissue Relaxation Times in Different Mouse Models Assessed by Ultrahigh Field Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Andreas Müller

    2017-01-01

    Full Text Available Recently, clinical studies demonstrated that magnetic resonance relaxometry with determination of relaxation times T1 and T2⁎ may aid in staging and management of liver fibrosis in patients suffering from viral hepatitis and steatohepatitis. In the present study we investigated T1 and T2⁎ in different models of liver fibrosis to compare alternate pathophysiologies in their effects on relaxation times and to further develop noninvasive quantification methods of liver fibrosis. MRI was performed with a fast spin echo sequence for measurement of T1 and a multigradient echo sequence for determination of T2⁎. Toxic liver fibrosis was induced by injections of carbon tetrachloride (1.4 mL CCl4 per kg bodyweight and week, for 3 or 6 weeks in BALB/cJ mice. Chronic sclerosing cholangitis was mimicked using the ATP-binding cassette transporter B4 knockout (Abcb4 -/- mouse model. Untreated BALB/cJ mice served as controls. To assess hepatic fibrosis, we ascertained collagen contents and fibrosis scores after Sirius red staining. T1 and T2⁎ correlate differently to disease severity and etiology of liver fibrosis. T2⁎ shows significant decrease correlating with fibrosis in CCl4 treated animals, while demonstrating significant increase with disease severity in Abcb4 -/- mice. Measurements of T1 and T2⁎ may therefore facilitate discrimination between different stages and causes of liver fibrosis.

  13. Effect of sulfur dioxide inhalation on CYP2B1/2 and CYP2E1 in rat liver and lung

    Energy Technology Data Exchange (ETDEWEB)

    Guohua Qin; Ziqiang Meng [Shanxi University, Taiyuan (China). Institute of Environmental Medicine and Toxicology

    2006-07-15

    Sulfur dioxide (SO{sub 2}) is a ubiquitous air pollutant, present in low concentrations in the urban air and in higher concentrations in the working environment. In this study, we investigated the effects of inhaled SO{sub 2} on the O-dealkylase of pentoxyresorufin (PROD) and p-nitrophenol hydroxylases (p-NP) activities and mRNA levels of CYP2B1/2 and CYP2E1 in the lung and liver of Wistar rats. Male Wistar rats were housed in exposure chambers and treated with 14.11 {+-}1.53, 28.36 {+-} 2.12, and 56.25 {+-} 4.28 mg /m{sup 3}SO{sub 2} for 6 h/day for 7 days, while control rats were exposed to filtered air in the same condition. The mRNAs of CYP2B1/2 and -2E1 were analyzed in livers and lungs by using reverse-transcription polymerase chain reaction (RT-PCR). Results showed that the PROD activities and mRNA of CYP2B1/2 were decreased in livers and lungs of rats exposed to SO{sub 2}. The p-NP activities and mRNA of CYP2E1 were decreased in lungs but not in livers of rats exposed to SO{sub 2}. Total liver microsomal cytochrome P-450 (CYP) contents were diminished in SO{sub 2} -exposed rats. These results lead to two conclusions: (1) SO{sub 2} exposure can suppress CYP2B1/2 and CYP2E1 in lungs and CYP2B1/2 in livers of rats, thus modifying the liver and lung toxication/detoxication potential, and (2) the total liver microsomal CYP contents were diminished, although the activity and mRNA expression of CYP2E1 in rat livers were not affected by SO{sub 2} exposure.

  14. Type 2 iodothyronine deiodinase levels are higher in slow-twitch than fast-twitch mouse skeletal muscle and are increased in hypothyroidism.

    Science.gov (United States)

    Marsili, Alessandro; Ramadan, Waile; Harney, John W; Mulcahey, Michelle; Castroneves, Luciana Audi; Goemann, Iuri Martin; Wajner, Simone Magagnin; Huang, Stephen A; Zavacki, Ann Marie; Maia, Ana Luiza; Dentice, Monica; Salvatore, Domenico; Silva, J Enrique; Larsen, P Reed

    2010-12-01

    Because of its large mass, relatively high metabolic activity and responsiveness to thyroid hormone, skeletal muscle contributes significantly to energy expenditure. Despite the presence of mRNA encoding the type 2 iodothyronine-deiodinase (D2), an enzyme that activates T(4) to T3, very low or undetectable activity has been reported in muscle homogenates of adult humans and mice. With a modified D2 assay, using microsomal protein, overnight incubation and protein from D2 knockout mouse muscle as a tissue-specific blank, we examined slow- and fast-twitch mouse skeletal muscles for D2 activity and its response to physiological stimuli. D2 activity was detectable in all hind limb muscles of 8- to 12-wk old C57/BL6 mice. Interestingly, it was higher in the slow-twitch soleus than in fast-twitch muscles (0.40 ± 0.06 vs. 0.076 ± 0.01 fmol/min · mg microsomal protein, respectively, P Hypothyroidism caused a 40% (P hypothyroidism argue for a more important role for D2-generated T(3) in skeletal muscle physiology than previously assumed.

  15. Cytochrome P4502D6(193-212): a new immunodominant epitope and target of virus/self cross-reactivity in liver kidney microsomal autoantibody type 1-positive liver disease.

    Science.gov (United States)

    Kerkar, Nanda; Choudhuri, Kaushik; Ma, Yun; Mahmoud, Ayman; Bogdanos, Dimitrios P; Muratori, Luigi; Bianchi, Francesco; Williams, Roger; Mieli-Vergani, Giorgina; Vergani, Diego

    2003-02-01

    Cytochrome P4502D6 (CYP2D6), target of liver kidney microsomal autoantibody type 1 (LKM1), characterizes autoimmune hepatitis type 2 (AIH2) but is also found in patients with chronic hepatitis C virus (HCV) infection. To provide a complete linear epitope B cell map of CYP2D6, we tested peptides spanning the entire sequence of CYP2D6. In addition to confirming previously described antigenic sites, we identified four new epitopes (193-212, 238-257, 268-287, and 478-497). CYP2D6(193-212) is immunodominant and was the target of 12 of 13 (93%) patients with AIH2 and 5 of 10 (50%) HCV/LKM1-positive patients. Because LKM1 is present in both AIH2 and a viral infection, we tested whether Abs to CYP2D6(193-212) arise through cross-reactive immunity between virus and self. We identified a hexameric sequence "RLLDLA" sharing 5 of 6 aa with "RLLDLS" of HCV(2985-2990) and all 6 aa with CMV(130-135). Of 17 CYP2D6(193-212)-reactive sera, 11 (7 AIH and 4 HCV) reacted by ELISA with the HCV homologue, 8 (5 AIH and 3 HCV) with the CMV homologue, and 8 (5 AIH and 3 HCV) showed double reactivity. Autoantibody binding to CYP2D6(193-212) was inhibited by preincubation with HCV(2977-2996) or CMV(121-140). Recombinant HCV-nonstructural protein 5 and CMV-UL98 proteins also inhibited Ab binding to CYP2D6(193-212). Affinity-purified CYP2D6(193-212)-specific Ab inhibited the metabolic activity of CYP2D6. The demonstrated similarity and cross-reactivity between CYP2D6(193-212) and two unrelated viruses suggests that multiple exposure to viruses mimicking self may represent an important pathway to the development of autoimmunity.

  16. Influence of nutrition on liver oxidative metabolism.

    Science.gov (United States)

    Jorquera, F; Culebras, J M; González-Gallego, J

    1996-06-01

    The liver plays a major role in the disposition of the majority of drugs. This is due to the presence of several drug-metabolizing enzyme systems, including a group of membrane-bound mixed-function oxidative enzymes, mainly the cytochrome P450 system. Hepatic oxidative capacity can be assessed by changes in antipyrine metabolism. Different drugs and other factors may induce or inhibit the cytochrome P450-dependent system. This effect is important in terms of the efficacy or toxicity of drugs that are substrates for the system. Microsomal oxidation in animals fed with protein-deficient diets is depressed. The mixed-function oxidase activity recovers after a hyperproteic diet or the addition of lipids. Similar findings have been reported in patients with protein-calorie malnutrition, although results in the elderly are conflicting. Different studies have revealed that microsomal oxidation is impaired by total parenteral nutrition and that this effect is absent when changing the caloric source from carbohydrates to a conventional amino acid solution or after lipid addition, especially when administered as medium-chain/long-chain triglyceride mixtures. Peripheral parenteral nutrition appears to increase antipyrine clearance.

  17. 31P-NMR studies on perfused mouse liver

    International Nuclear Information System (INIS)

    McLaughlin, A.C.; Takeda, H.; Chance, B.

    1978-01-01

    From a metabolic viewpoint, the most important organ in the body is the liver. In contrast to more specialized organs such as heart and kidney which perform only one major function, the liver performs a number of major metabolic functions. Two of the most important functions are the catabolism and storage of foodstuffs (in the form of glycogen) and the control of most of the constituents of the blood (in particular, the blood glucose level). Most of these functions are localized within a single type of cell. One way that the liver is able to regulate these diverse reactions is by the control of the ATP level in the cell. Encouraged by the recent success of many groups in using 31 P-NMR to provide a continuous and non-destructive monitor of ATP levels in isolated cells, skeletal muscle, and perfused organs such as heart and kidney, 31 P-NMR was used to investigate ATP levels in perfused liver of mice

  18. Phosphatase and tensin homolog-β-catenin signaling modulates regulatory T cells and inflammatory responses in mouse liver ischemia/reperfusion injury.

    Science.gov (United States)

    Zhu, Qiang; Li, Changyong; Wang, Kunpeng; Yue, Shi; Jiang, Longfeng; Ke, Michael; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Zhang, Feng; Lu, Ling; Ke, Bibo

    2017-06-01

    The phosphatase and tensin homolog (PTEN) deleted on chromosome 10 plays an important role in regulating T cell activation during inflammatory response. Activation of β-catenin is crucial for maintaining immune homeostasis. This study investigates the functional roles and molecular mechanisms by which PTEN-β-catenin signaling promotes regulatory T cell (Treg) induction in a mouse model of liver ischemia/reperfusion injury (IRI). We found that mice with myeloid-specific phosphatase and tensin homolog knockout (PTEN M-KO ) exhibited reduced liver damage as evidenced by decreased levels of serum alanine aminotransferase, intrahepatic macrophage trafficking, and proinflammatory mediators compared with the PTEN-proficient (floxed phosphatase and tensin homolog [PTEN FL/FL ]) controls. Disruption of myeloid PTEN-activated b-catenin promoted peroxisome proliferator-activated receptor gamma (PPARγ)-mediated Jagged-1/Notch signaling and induced forkhead box P3 (FOXP3)1 Tregs while inhibiting T helper 17 cells. However, blocking of Notch signaling by inhibiting γ-secretase reversed myeloid PTEN deficiency-mediated protection in ischemia/reperfusion-triggered liver inflammation with reduced FOXP3 + and increased retinoid A receptor-related orphan receptor gamma t-mediated interleukin 17A expression in ischemic livers. Moreover, knockdown of β-catenin or PPARγ in PTEN-deficient macrophages inhibited Jagged-1/Notch activation and reduced FOXP3 + Treg induction, leading to increased proinflammatory mediators in macrophage/T cell cocultures. In conclusion, our findings demonstrate that PTEN-β-catenin signaling is a novel regulator involved in modulating Treg development and provides a potential therapeutic target in liver IRI. Liver Transplantation 23 813-825 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

  19. Understanding Liver Regeneration: From Mechanisms to Regenerative Medicine.

    Science.gov (United States)

    Gilgenkrantz, Hélène; Collin de l'Hortet, Alexandra

    2018-04-16

    Liver regeneration is a complex and unique process. When two-thirds of a mouse liver is removed, the remaining liver recovers its initial weight in approximately 10 days. The understanding of the mechanisms responsible for liver regeneration may help patients needing large liver resections or transplantation and may be applied to the field of regenerative medicine. All differentiated hepatocytes are capable of self-renewal, but different subpopulations of hepatocytes seem to have distinct proliferative abilities. In the setting of chronic liver diseases, a ductular reaction ensues in which liver progenitor cells (LPCs) proliferate in the periportal region. Although these LPCs have the capacity to differentiate into hepatocytes and biliary cells in vitro, their ability to participate in liver regeneration is far from clear. Their expansion has even been associated with increased fibrosis and poorer prognosis in chronic liver diseases. Controversies also remain on their origin: lineage studies in experimental mouse models of chronic injury have recently suggested that these LPCs originate from hepatocyte dedifferentiation, whereas in other situations, they seem to come from cholangiocytes. This review summarizes data published in the past 5 years in the liver regeneration field, discusses the mechanisms leading to regeneration disruption in chronic liver disorders, and addresses the potential use of novel approaches for regenerative medicine. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  20. In vitro Inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea, and Curcuma xanthorrhiza Extracts and Constituents on Human Liver Glucuronidation Activity.

    Science.gov (United States)

    Husni, Zulhilmi; Ismail, Sabariah; Zulkiffli, Mohd Halimhilmi; Afandi, Atiqah; Haron, Munirah

    2017-07-01

    Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza are commonly consumed as herbal medicines. However their effects on human liver glucuronidation activity are not yet evaluated. In this study, we evaluate the inhibitory Effects of Andrographis paniculata, Gynura procumbens, Ficus deltoidea and Curcuma xanthorrhiza extracts and their constituents on human liver glucuronidation activity. Herbal extracts (aqueous, methanolic and ethanolic extracts) and their constituents were incubated with human liver microsomes with the addition of UDPGA to initiate the reaction. Working concentrations of herbal extracts and their constituents ranged from 10 μg/mL to 1000 μg/mL and 10 μM to 300 μM respectively. IC50 was determined by monitoring the decrement of glucuronidation activity with the increment of herbal extracts or phytochemical constituent's concentrations. All herbal extracts inhibited human liver glucuronidation activity in range of 34.69 μg/mL to 398.10 μg/mL whereas for the constituents, only xanthorrhizol and curcumin (constituents of Curcuma xanthorrhiza ) inhibited human liver glucuronidation activity with IC50 of 538.50 and 32.26 μM respectively. In the present study, we have proved the capabilities of Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza to interfere with in vitro glucuronidation process in human liver microsomes. This study documented the capabilities of Andrographis paniculata , Gynura procumbens , Ficus deltoidea and Curcuma xanthorrhiza to inhibit human liver glucuronidation activity which may affect the metabolism of therapeutic drugs or hazardous toxicants that follow the same glucuronidation pathway. Abbreviations used: UGT: Uridine 5'-diphospho-glucuronosyltransferase; 4-MU: 4-methylumbelliferone; IC50: Half Maximal Inhibitory Concentration; Km: Michaelis constant; Vmax: Maximum velocity.

  1. Up-regulation of calreticulin in mouse liver tissues after long-term irradiation with low-dose-rate gamma rays.

    Science.gov (United States)

    Yi, Lan; Hu, Nan; Yin, Jie; Sun, Jing; Mu, Hongxiang; Dai, Keren; Ding, Dexin

    2017-01-01

    The biological effects of low-dose or low-dose-rate ionizing radiation on normal tissues has attracted attention. Based on previous research, we observed the morphology of liver tissues of C57BL/6J mice that received irradiation dose rates increased. Additionally, differential protein expression in liver tissues was analyzed using a proteomics approach. Compared with the matched group in the 2D gel analysis of the irradiated groups, 69 proteins had ≥ 1.5-fold changes in expression. Twenty-three proteins were selected based on ≥2.5-fold change in expression, and 22 of them were meaningful for bioinformatics and protein fingerprinting analysis. These molecules were relevant to cytoskeleton processes, cell metabolism, biological defense, mitochondrial damage, detoxification and tumorigenesis. The results from real-time PCR and western blot (WB) analyses showed that calreticulin (CRT) was up-regulated in the irradiated groups, which indicates that CRT may be relevant to stress reactions when mouse livers are exposed to low-dose irradiation and that low-dose-rate ionizing radiation may pose a cancer risk. The CRT protein can be a potential candidate for low-dose or low-dose-rate ionizing radiation early-warning biomarkers. However, the underlying mechanism requires further investigation.

  2. The antibiotic tiamulin is a potent inducer and inhibitor of cytochrome P4503A via the formation of a stable metabolic intermediate complex. Studies in primary hepatocyte cultures and liver microsomes of the pig.

    Science.gov (United States)

    Witkamp, R F; Nijmeijer, S M; Monshouwer, M; Van Miert, A S

    1995-05-01

    Tiamulin is a semisynthetic antibiotic frequently used in agricultural animals. The drug has been shown to produce clinically important--often lethal--interactions with other compounds that are simultaneously administered. To explain this, it has been suggested that tiamulin selectively inhibits oxidative drug metabolism via the formation of a cytochrome P450 metabolic intermediate complex. The aim of the present study was to provide further support for this hypothesis. When hepatic microsomes and cultured primary pig hepatocytes were incubated with tiamulin, a maximum in the absorbance spectrum at 455 nm was observed, which disappeared after adding KFe(CN)6. When hepatocytes were incubated with tiamulin for 72 hr, cytochrome P450 content and cytochrome P4503A apoprotein levels were increased. Tiamulin strongly inhibited and concentration dependently inhibited the hydroxylation rate of testosterone at the 6 beta-position in both microsomes and hepatocytes, and the microsomal N-demethylation rate of ethylmorphine. Other testosterone hydroxylations were inhibited to a lesser extent or not affected. The relative inhibition of the hydroxylation of testosterone at the 6 beta-position was more pronounced in microsomes from rifampicin- and triacetyloleandomycin-treated pigs. The results indicate that cytochrome P450 complex formation can at least partly explain the interactions observed with tiamulin. Tiamulin seems to be a strong, probably selective, inhibitor of the cytochrome P4503A subfamily and an interesting tool for further research.

  3. Characterization of binding of N'-nitrosonornicotine to protein

    International Nuclear Information System (INIS)

    Hughes, M.F.

    1986-01-01

    The NADPH-dependent activation of the carcinogenic nitrosamine, N'-nitrosonornicotine (NNN) to a reactive intermediate which binds covalently to protein was assessed using male Sprague-Dawley rat liver and lung microsomes. The NADPH-dependent covalent binding of [ 14 C]NNN to liver and lung microsomes was linear with time up to 90 and 45 min, respectively and was also linear with protein concentrations up to 3.0 and 2.0 mg/ml, respectively. The apparent K/sub m/ and V/sub max/ of the NADPH-dependent binding to liver microsomes were determined from the initial velocities. Addition of the thiols glutathione, cystein, N-acetylcysteine or 2-mercapthoethanol significantly decreased the non-NADPH-dependent binding to liver microsomal protein, but did not affect the NADPH-dependent binding. Glutathione was required in order to observe any NADPH-dependent binding to lung microsomal protein. In lung microsomes, SKF-525A significantly decreased the NADPH-dependent binding by 79%. Replacement of an air atmosphere with N 2 or CO:O 2 (8:2) significantly decreased the NADPH-dependent binding of [ 14 C]NNN to liver microsomal protein by 40% or 27% respectively. Extensive covalent binding of [ 14 C]NNN to liver and muscle microsomal protein occurred in the absence of an NADPH-generating system, in the presence of 50% methanol and also to bovine serum albumin, indicating a nonenzymatic reaction. These data indicate that cytochrome P-450 is at least in part responsible for the metabolic activation of the carcinogen NNN, but also suggest additional mechanisms of activation

  4. Identification and characterization of vilazodone metabolites in rats and microsomes by ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry.

    Science.gov (United States)

    Chavan, Balasaheb B; Kalariya, Pradipbhai D; Tiwari, Shristy; Nimbalkar, Rakesh D; Garg, Prabha; Srinivas, R; Talluri, M V N Kumar

    2017-12-15

    Vilazodone is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of major depressive disorder (MDD). An extensive literature search found few reports on the in vivo and in vitro metabolism of vilazodone. Therefore, we report a comprehensive in vivo and in vitro metabolic identification and structural characterization of vilazodone using ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS/MS) and in silico toxicity study of the metabolites. To identify in vivo metabolites of vilazodone, blood, urine and faeces samples were collected at different time intervals starting from 0 h to 48 h after oral administration of vilazodone to Sprague-Dawley rats. The in vitro metabolism study was conducted with human liver microsomes (HLM) and rat liver microsomes (RLM). The samples were prepared using an optimized sample preparation approach involving protein precipitation followed by solid-phase extraction. The metabolites have been identified and characterized by using LC/ESI-MS/MS. A total of 12 metabolites (M1-M12) were identified in in vivo and in vitro matrices and characterized by LC/ESI-MS/MS. The majority of the metabolites were observed in urine, while a few metabolites were present in faeces and plasma. Two metabolites were observed in the in vitro study. A semi-quantitative study based on percentage counts shows that metabolites M11, M6 and M8 were observed in higher amounts in urine, faeces and plasma, respectively. The structures of all the 12 metabolites were elucidated by using LC/ESI-MS/MS. The study suggests that vilazodone was metabolized via hydroxylation, dihydroxylation, glucuronidation, oxidative deamination, dealkylation, dehydrogenation and dioxidation. All the metabolites were screened for toxicity using an in silico tool. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Identification of metabolites of the tryptase inhibitor CRA-9249: observation of a metabolite derived from an unexpected hydroxylation pathway.

    Science.gov (United States)

    Yu, Walter; Dener, Jeffrey M; Dickman, Daniel A; Grothaus, Paul; Ling, Yun; Liu, Liang; Havel, Chris; Malesky, Kimberly; Mahajan, Tania; O'Brian, Colin; Shelton, Emma J; Sperandio, David; Tong, Zhiwei; Yee, Robert; Mordenti, Joyce J

    2006-08-01

    The metabolites of the tryptase inhibitor CRA-9249 were identified after exposure to liver microsomes. CRA-9249 was found to be degraded rapidly in liver microsomes from rabbit, dog, cynomolgus monkey, and human, and less rapidly in microsomes from rat. The key metabolites included cleavage of an aryl ether, in addition to an unexpected hydroxylation of the amide side chain adjacent to the amide nitrogen. The chemical structures of both metabolites were confirmed by synthesis and comparison to material isolated from the liver microsomes. Several suspected hydroxylated metabolites were also synthesized and analyzed as part of the structure identification process.

  6. Diagnosis and Management of Paediatric Autoimmune Liver Disease: ESPGHAN Hepatology Committee Position Statement.

    Science.gov (United States)

    Mieli-Vergani, Giorgina; Vergani, Diego; Baumann, Ulrich; Czubkowski, Piotr; Debray, Dominique; Dezsofi, Antal; Fischler, Björn; Gupte, Girish; Hierro, Loreto; Indolfi, Giuseppe; Jahnel, Jörg; Smets, Françoise; Verkade, Henkjan J; Hadzic, Nedim

    2017-11-03

    Paediatric autoimmune liver disease is characterised by inflammatory liver histology, circulating autoantibodies and increased levels of IgG, in the absence of a known etiology. Three conditions have a likely autoimmune pathogenesis: autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. Two types of paediatric AIH are recognized according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, AIH-1) or liver kidney microsomal type 1 and/or anti-liver cytosol type 1 antibodies (anti-LKM-1/anti-LC-1; AIH-2).Pertinent issues addressing the diagnosis, treatment and long term follow up were formulated by a core group of ESPGHAN members. They have commissioned the first authors with execution of this project. Initially, they have performed a systematic literature search on MEDLINE, ResearchGate and Mendeley databases over the last 30 years and produced a document focusing on prospective and retrospective studies in children. The ESPGHAN core group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique.

  7. Metabolic profiling of five flavonoids from Dragon's Blood in human liver microsomes using high-performance liquid chromatography coupled with high resolution mass spectrometry.

    Science.gov (United States)

    Li, Yujuan; Zhang, Yushi; Wang, Rui; Wei, Lizhong; Deng, Yulin; Ren, Wei

    2017-05-01

    Although much is known about the pharmacological activities of Dragon's Blood (DB, a traditional Chinese herb), its metabolism in human liver microsomes (HLMs) and the cytochrome P450 (CYP) enzymes has not been studied. This study aims to identify the metabolic profile of five flavonoids (loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone) from DB in HLMs as well as the CYP enzymes that are involved in the metabolism of them. High-resolution mass spectrometry was used to characterize the structures of their metabolites and 10 cDNA-expressed CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5) were used to verify which isozymes mediate in the metabolism of the metabolites. Totally, 29 metabolites including 10 metabolites of loureirin A, 10 metabolites of loureirin B, 4 metabolites of loureirin C, 2 metabolites of 7,4'-dihydroxyflavone and 3 metabolites of 5,7,4'-trihydroxyflavanone were elucidated and identified on the basis of the high-resolution MS n data. The metabolic profile of the five flavonoids in HLMs involved hydroxylation, oxidation and demethylation. Among them, hydroxylation was the predominant biotransformation of the five flavonoids in HLMs, occurring in combination with other metabolic reactions. Assay with recombinant P450s revealed that CYP2C9 and CYP2C19 played an important role in the hydroxylation of flavonoids in HLMs. To the best of our knowledge, this is the first in vitro evaluation of the metabolic profile of loureirin A, loureirin B, loureirin C, 7,4'-dihydroxyflavone and 5,7,4'-trihydroxyflavanone in HLMs. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Sorafenib metabolism is significantly altered in the liver tumor tissue of hepatocellular carcinoma patient.

    Directory of Open Access Journals (Sweden)

    Ling Ye

    Full Text Available BACKGROUND: Sorafenib, the drug used as first line treatment for hepatocellular carcinoma (HCC, is metabolized by cytochrome P450 (CYP 3A4-mediated oxidation and uridine diphosphate glucuronosyl transferase (UGT 1A9-mediated glucuronidation. Liver diseases are associated with reduced CYP and UGT activities, which can considerably affect drug metabolism, leading to drug toxicity. Thus, understanding the metabolism of therapeutic compounds in patients with liver diseases is necessary. However, the metabolism characteristic of sorafenib has not been systematically determined in HCC patients. METHODS: Sorafenib metabolism was tested in the pooled and individual tumor hepatic microsomes (THLMs and adjacent normal hepatic microsomes (NHLMs of HCC patients (n = 18. Commercial hepatic microsomes (CHLMs were used as a control. In addition, CYP3A4 and UGT1A9 protein expression in different tissues were measured by Western blotting. RESULTS: The mean rates of oxidation and glucuronidation of sorafenib were significantly decreased in the pooled THLMs compared with those in NHLMs and CHLMs. The maximal velocity (Vmax of sorafenib oxidation and glucuronidation were approximately 25-fold and 2-fold decreased in the pooled THLMs, respectively, with unchanged Km values. The oxidation of sorafenib in individual THLMs sample was significantly decreased (ranging from 7 to 67-fold than that in corresponding NHLMs sample. The reduction of glucuronidation in THLMs was observed in 15 out of 18 patients' samples. Additionally, the level of CYP3A4 and UGT1A9 expression were both notably decreased in the pooled THLMs. CONCLUSIONS: Sorafenib metabolism was remarkably decreased in THLMs. This result was associated with the down regulation of the protein expression of CYP3A4 and UGT1A9.

  9. Early effects of dietary orotic acid upon liver lipid synthesis and bile cholesterol secretion in rats

    International Nuclear Information System (INIS)

    Tokmakjian, S.D.; Haines, D.S.

    1985-01-01

    Dietary orotic acid is known to cause impaired fatty acid synthesis and increased cholesterol synthesis in rats. The authors found that the impaired fatty acid synthesis occurs during the first day of orotic acid feeding and, in studies with albumin-bound [1- 14 C]palmitic acid, an associated decrease in the rate of esterification of this fatty acid into triacylglycerol, phospholipid, and cholesteryl ester was observed. These changes may result from the known decreases in liver levels of adenine nucleotides or, as reported here, from decreased liver CoASH levels in orotic acid-fed rats. The increase in hepatic cholesterol synthesis occurred during the second day of orotic acid feeding. It was detected by increased incorporation of [1,2- 14 C]acetate into cholesterol by liver slices and by a 7-fold increase in HMG-CoA reductase activity. At the same time the biliary output of cholesterol was increased 2-fold and studies using 3 H 2 O revealed that the output of newly synthesized cholesterol in bile was increased 5-fold. The content of cholesteryl ester in hepatic microsomes decreased during orotic acid feeding but free cholesterol was unchanged. The findings are interpreted to suggest that the increased bile cholesterol secretion caused by orotic acid is a result of impaired hepatic cholesterol esterification and that the increase in HMG-CoA reductase activity is a result of diminished negative feedback due to the depleted content of cholesteryl ester in the hepatic microsomes

  10. MEK kinase 1 activity is required for definitive erythropoiesis in the mouse fetal liver

    DEFF Research Database (Denmark)

    Bonnesen, Barbara; Ørskov, Cathrine; Rasmussen, Susanne

    2005-01-01

    for MEKK1 in definitive mouse erythropoiesis. Although Mekk1(DeltaKD) mice are alive and fertile on a 129 x C57/BL6 background, the frequency of Mekk1(DeltaKD) embryos that develop past embryonic day (E) 14.5 is dramatically reduced when backcrossed into the C57/BL6 background. At E13.5, Mekk1(Delta......KD) embryos have normal morphology but are anemic due to failure of definitive erythropoiesis. When Mekk1(DeltaKD) fetal liver cells were transferred to lethally irradiated wild-type hosts, mature red blood cells were generated from the mutant cells, suggesting that MEKK1 functions in a non......-cell-autonomous manner. Based on immunohistochemical and hemoglobin chain transcription analysis, we propose that the failure of definitive erythropoiesis is due to a deficiency in enucleation activity caused by insufficient macrophage-mediated nuclear DNA destruction....

  11. Calmodulin stimulation of calcium transport in carrot microsomal vesicles

    International Nuclear Information System (INIS)

    Pierce, W.S.; Sze, H.

    1987-01-01

    ATP-dependent 45 Ca 2+ uptake into microsomal vesicles isolated from cultured carrot cells (Daucus carota Danvers) was stimulated 2-3 fold by 5 ug/ml calmodulin (CaM). Microsomal vesicles separated with a linear sucrose gradient showed two peaks with CaM-stimulated Ca 2+ uptake activities. One peak (at 1.12 g/cc) comigrated with the activity of the antimycin A-insensitive NADH-dependent cytochrome c reductase. This transport activity was enhanced 10-20 fold by 10 mM oxalate and appeared to be associates with vesicles derived primarily from the ER. The other peak of CaM-stimulated Ca 2+ uptake (at 1.17 g/cc) was not affected by oxalate. These vesicles are probably derived from the plasma membrane. Preliminary experiments with the low-density vesicles (ER) vesicles, indicate that inositol-1,4,5-trisphosphate caused a transient reduction in intravesicular Ca 2+ . These results are consistent with the ER being an important site of intracellular Ca 2+ regulation

  12. Differential response of the liver to bile acid treatment in a mouse model of Niemann-Pick disease type C [version 2; referees: 2 approved, 1 not approved

    Directory of Open Access Journals (Sweden)

    Elena-Raluca Nicoli

    2018-04-01

    Full Text Available Niemann-Pick disease type C (NPC disease is a neurodegenerative lysosomal storage disease caused by mutations in the NPC1 or NPC2 genes. Liver disease is also a common feature of NPC that can present as cholestatic jaundice in the neonatal period. Liver enzymes can remain elevated above the normal range in some patients as they age. We recently reported suppression of the P450 detoxification system in a mouse model of NPC disease and also in post-mortem liver from NPC patients. We demonstrated the ability of the hydrophobic bile acid ursodeoxycholic acid (UDCA (3α, 7β-dihydroxy-5β-cholanic acid to correct the P450 system suppression. UDCA is used to treat several cholestatic disorders and was tested in NPC due to the P450 system being regulated by bile acids. Here, we compare the effect of UDCA and cholic acid (CA, another bile acid, in the NPC mouse model. We observed unexpected hepatotoxicity in response to CA treatment of NPC mice. No such hepatotoxicity was associated with UDCA treatment. These results suggest that CA treatment is contraindicated in NPC patients, whilst supporting the use of UDCA as an adjunctive therapy in NPC patients.

  13. Effect of dietary advanced glycation end products on mouse liver.

    Directory of Open Access Journals (Sweden)

    Raza Patel

    Full Text Available UNLABELLED: The exact pathophysiology of non-alcoholic steatohepatitis (NASH is not known. Previous studies suggest that dietary advanced glycation end products (AGEs can cause oxidative stress in liver. We aim to study the effects of dietary AGEs on liver health and their possible role in the pathogenesis of NASH. METHODS: Two groups of mice were fed the same diet except the AGE content varied. One group was fed a high AGE diet and the second group was fed a regular AGE diet. Liver histology, alanine aminotransferase, aspartate aminotransferase, fasting glucose, fasting insulin, insulin resistance and glucose tolerance were assessed. RESULTS: Histology revealed that neutrophil infiltration occurred in the livers of the high AGE group at week 26; steatosis did not accompany liver inflammation. At week 39 livers from both groups exhibited macro- or micro-steatosis, yet no inflammation was detected. Higher insulin levels were detected in the regular AGE group at week 26 (P = 0.034, compared to the high AGE group. At week 39, the regular AGE group showed higher levels of alanine aminotransferase (P<0.01 and aspartate aminotransferase (P = 0.02 than those of the high AGE group. CONCLUSIONS: We demonstrate that a high AGE diet can cause liver inflammation in the absence of steatosis. Our results show that dietary AGEs could play a role in initiating liver inflammation contributing to the disease progression of NASH. Our observation that the inflammation caused by high AGE alone did not persist suggests interesting future directions to investigate how AGEs contribute to pro-oxidative and anti-oxidative pathways in the liver.

  14. Aetiology and pathogenesis of alcoholic liver disease.

    Science.gov (United States)

    Lieber, C S

    1993-09-01

    Until the 1960s, liver disease of the alcoholic patient was attributed exclusively to dietary deficiencies. Since then, however, our understanding of the impact of alcoholism on nutritional status has undergone a progressive evolution. Alcohol, because of its high energy content, was at first perceived to act exclusively as 'empty calories' displacing other nutrients in the diet, and causing primary malnutrition through decreased intake of essential nutrients. With improvement in the overall nutrition of the population, the role of primary malnutrition waned and secondary malnutrition was emphasized as a result of a better understanding of maldigestion and malabsorption caused by chronic alcohol consumption and various diseases associated with chronic alcoholism. At the same time, the concept of the direct toxicity of alcohol came to the forefront as an explanation for the widespread cellular injury. Some of the hepatotoxicity was found to result from the metabolic disturbances associated with the oxidation of ethanol via the liver alcohol dehydrogenase (ADH) pathway and the redox changes produced by the generated NADH, which in turn affects the metabolism of lipids, carbohydrates, proteins and purines. Exaggeration of the redox change by the relative hypoxia which prevails physiologically in the perivenular zone contributes to the exacerbation of the ethanol-induced lesions in zone 3. In addition to ADH, ethanol can be oxidized by liver microsomes: studies over the last twenty years have culminated in the molecular elucidation of the ethanol-inducible cytochrome P450IIE1 (CYP2E1) which contributes not only to ethanol metabolism and tolerance, but also to the selective hepatic perivenular toxicity of various xenobiotics. Their activation by CYP2E1 now provides an understanding for the increased susceptibility of the heavy drinker to the toxicity of industrial solvents, anaesthetic agents, commonly prescribed drugs, 'over the counter' analgesics, chemical

  15. Autoimmune liver disease in children.

    Science.gov (United States)

    Mieli-Vergani, G; Vergani, D

    2003-03-01

    Autoimmune liver disorders are characterised by an inflammatory liver histology, circulating non-organ specific autoantibodies and increased levels of immunoglobulin G (IgG) in the absence of a known aetiology. They respond to immunosuppressive treatment, which should be instituted as soon as diagnosis is made. Liver disorders with a likely autoimmune pathogenesis include autoimmune hepatitis (AIH) and autoimmune sclerosing cholangitis (ASC). Two types of AIH are recognised according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1) or liver kidney microsomal antibody (LKM1, type 2). There is a female predominance in both. LKM1-positive patients tend to present more acutely, at a younger age, and commonly have immunoglobulin A (IgA) deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment and long-term prognosis are similar in both groups. The most common type of paediatric sclerosing cholangitis is ASC. The clinical, biochemical, immunological and histological presentation of ASC is often indistinguishable from that of AIH. In both, there are high IgG, non-organ specific autoantibodies and interface hepatitis. Diagnosis is made by cholangiography. Children with ASC respond to immunosuppression satisfactorily and similarly to AIH in respect to remission and relapse rates, times to normalisation of biochemical parameters and decreased inflammatory activity on follow-up liver biopsies. However, the cholangiopathy can progress and there may be an evolution from AIH to ASC over the years, despite treatment. Whether the juvenile autoimmune form of sclerosing cholangitis and AIH are 2 distinct entities, or different aspects of the same condition, remains to be elucidated.

  16. CYP1A1 and CYP1A2 expression: Comparing 'humanized' mouse lines and wild-type mice; comparing human and mouse hepatoma-derived cell lines

    International Nuclear Information System (INIS)

    Uno, Shigeyuki; Endo, Kaori; Ishida, Yuji; Tateno, Chise; Makishima, Makoto; Yoshizato, Katsutoshi; Nebert, Daniel W.

    2009-01-01

    Human and rodent cytochrome P450 (CYP) enzymes sometimes exhibit striking species-specific differences in substrate preference and rate of metabolism. Human risk assessment of CYP substrates might therefore best be evaluated in the intact mouse by replacing mouse Cyp genes with human CYP orthologs; however, how 'human-like' can human gene expression be expected in mouse tissues? Previously a bacterial-artificial-chromosome-transgenic mouse, carrying the human CYP1A1 C YP1A2 locus and lacking the mouse Cyp1a1 and Cyp1a2 orthologs, was shown to express robustly human dioxin-inducible CYP1A1 and basal versus inducible CYP1A2 (mRNAs, proteins, enzyme activities) in each of nine mouse tissues examined. Chimeric mice carrying humanized liver have also been generated, by transplanting human hepatocytes into a urokinase-type plasminogen activator(+/+) s evere-combined-immunodeficiency (uPA/SCID) line with most of its mouse hepatocytes ablated. Herein we compare basal and dioxin-induced CYP1A mRNA copy numbers, protein levels, and four enzymes (benzo[a]pyrene hydroxylase, ethoxyresorufin O-deethylase, acetanilide 4-hydroxylase, methoxyresorufin O-demethylase) in liver of these two humanized mouse lines versus wild-type mice; we also compare these same parameters in mouse Hepa-1c1c7 and human HepG2 hepatoma-derived established cell lines. Most strikingly, mouse liver CYP1A1-specific enzyme activities are between 38- and 170-fold higher than human CYP1A1-specific enzyme activities (per unit of mRNA), whereas mouse versus human CYP1A2 enzyme activities (per unit of mRNA) are within 2.5-fold of one another. Moreover, both the mouse and human hepatoma cell lines exhibit striking differences in CYP1A mRNA levels and enzyme activities. These findings are relevant to risk assessment involving human CYP1A1 and CYP1A2 substrates, when administered to mice as environmental toxicants or drugs.

  17. Improved Resection and Outcome of Colon-Cancer Liver Metastasis with Fluorescence-Guided Surgery Using In Situ GFP Labeling with a Telomerase-Dependent Adenovirus in an Orthotopic Mouse Model.

    Directory of Open Access Journals (Sweden)

    Shuya Yano

    Full Text Available Fluorescence-guided surgery (FGS of cancer is an area of intense development. In the present report, we demonstrate that the telomerase-dependent green fluorescent protein (GFP-containing adenovirus OBP-401 could label colon-cancer liver metastasis in situ in an orthotopic mouse model enabling successful FGS. OBP-401-GFP-labeled liver metastasis resulted in complete resection with FGS, in contrast, conventional bright-light surgery (BLS did not result in complete resection of the metastasis. OBP-401-FGS reduced the recurrence rate and prolonged over-all survival compared with BLS. In conclusion, adenovirus OBP-401 is a powerful tool to label liver metastasis in situ with GFP which enables its complete resection, not possible with conventional BLS.

  18. Chemical and Hormonal Effects on STAT5b-Dependent Sexual Dimorphism of the Liver Transcriptome.

    Directory of Open Access Journals (Sweden)

    Keiyu Oshida

    Full Text Available The growth hormone (GH-activated transcription factor signal transducer and activator of transcription 5b (STAT5b is a key regulator of sexually dimorphic gene expression in the liver. Suppression of hepatic STAT5b signaling is associated with lipid metabolic dysfunction leading to steatosis and liver cancer. In the companion publication, a STAT5b biomarker gene set was identified and used in a rank-based test to predict both increases and decreases in liver STAT5b activation status/function with high (≥ 97% accuracy. Here, this computational approach was used to identify chemicals and hormones that activate (masculinize or suppress (feminize STAT5b function in a large, annotated mouse liver and primary hepatocyte gene expression compendium. Exposure to dihydrotestosterone and thyroid hormone caused liver masculinization, whereas glucocorticoids, fibroblast growth factor 15, and angiotensin II caused liver feminization. In mouse models of diabetes and obesity, liver feminization was consistently observed and was at least partially reversed by leptin or resveratrol exposure. Chemical-induced feminization of male mouse liver gene expression profiles was a relatively frequent phenomenon: of 156 gene expression biosets from chemically-treated male mice, 29% showed feminization of liver STAT5b function, while <1% showed masculinization. Most (93% of the biosets that exhibited feminization of male liver were also associated with activation of one or more xenobiotic-responsive receptors, most commonly constitutive activated receptor (CAR or peroxisome proliferator-activated receptor alpha (PPARα. Feminization was consistently associated with increased expression of peroxisome proliferator-activated receptor gamma (Pparg but not other lipogenic transcription factors linked to steatosis. GH-activated STAT5b signaling in mouse liver is thus commonly altered by diverse chemicals, and provides a linkage between chemical exposure and dysregulated gene

  19. Gene expression of drug metabolizing enzymes in adult and aged mouse liver: A modulation by immobilization stress

    International Nuclear Information System (INIS)

    Mikhailova, O.N.; Gulyaeva, L.F.; Filipenko, M.L.

    2005-01-01

    The role of stress in the regulation of enzymatic systems involved in the biotransformation of xenobiotics, as well as endogenous substrates in the liver was investigated using single immobilization stress as a model. Adult (3 months of age) and aged (26 months) C3H/a male mice were used. Cytochrome P450 1A1 and 1A2 (CYP1A1 and CYP1A2), glutathione S-transferase M1 (GSTM1), aryl hydrocarbon receptor (AHR), aryl hydrocarbon receptor nuclear translocator (ARNT) and catechol-O-methyltransferase (COMT) mRNA levels in the mouse liver were measured by a semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. Excluding CYP1A1, experiments revealed significant differences in the expression of these genes between adult- and aged-control animals. The influence of stress on the expression of genes studied was shown to be higher in adult mice than in aged ones. Our results clearly demonstrate the lack of response or even the attenuation of gene expression in aged animals that may play an important role in age-related pathologies and diseases

  20. Extractive biotransformation for production of metabolites of poorly soluble compounds: synthesis of 32-hydroxy-rifalazil.

    Science.gov (United States)

    Mozhaev, Vadim V; Mozhaeva, Lyudmila V; Michels, Peter C; Khmelnitsky, Yuri L

    2008-10-01

    A novel reaction system was developed for the production of metabolites of poorly water-soluble parent compounds using mammalian liver microsomes. The system includes the selection and use of an appropriate hydrophobic polymeric resin as a reservoir for the hydrophobic parent compounds and its metabolites. The utility of the extractive biotransformation approach was shown for the production of a low-yielding, synthetically challenging 32-hydroxylated metabolite of the antibiotic rifalazil using mouse liver microsomes. To address the low solubility and reactivity of rifalazil in the predominantly aqueous microsomal catalytic system, a variety of strategies were tested for the enhanced delivery of hydrophobic substrates, including the addition of mild detergents, polyvinylpyrrolidone, glycerol, bovine serum albumin, and hydrophobic polymeric resins. The latter strategy was identified as the most suitable for the production of 32-hydroxy-rifalazil, resulting in up to 13-fold enhancement of the volumetric productivity compared with the standard aqueous system operating at the solubility limit of rifalazil. The production process was optimized for a wide range of reaction parameters; the most important for improving volumetric productivity included the type and amount of the polymeric resin, cofactor recycling system, concentrations of the biocatalyst and rifalazil, reaction temperature, and agitation rate. The optimized extractive biotransformation system was used to synthesize 32-hydroxy-rifalazil on a multimilligram scale.

  1. Antimutagenic activity of some naturally occurring compounds towards cigarette-smoke condensate and benzo(a)pyrene in the Salmonella/microsome assay

    Energy Technology Data Exchange (ETDEWEB)

    Terwel, L.; van der Hoeven, J.C.

    1985-10-01

    Several compounds, occurring in food, were tested for antimutagenic activity towards cigarette-smoke condensate (CSC) and benzo(a)pyrene (BaP). Antimutagenicity was determined in the Salmonella/microsome test, with tester strain TA98, in the presence of rat-liver homogenate. Dose-response curves did show reduction of CSC- and BaP-induced mutagenicity by ellagic acid, riboflavin and chlorophyllin. Chlorophyll a and chlorophyll b, although less distinct, also inhibited CSC- and BaP-induced mutagenicity. Ascorbic acid, beta-carotene, tocopherol acetate, chlorogenic acid and butyl hydroxyanisole did not have any influence on the mutagenicity of CSC and BaP. The similarity in results for cigarette-smoke condensate and for BaP indicates that a general mechanism may be involved in the inhibition of CSC- and BaP-induced mutagenicity.

  2. Protoporphyrinogen oxidase: high affinity tetrahydrophthalimide radioligand for the inhibitor/herbicide-binding site in mouse liver mitochondria.

    Science.gov (United States)

    Birchfield, N B; Casida, J E

    1996-01-01

    Protoporphyrinogen oxidase (protox), the last common enzyme in heme and chlorophyll biosynthesis, is the target of several classes of herbicides acting as inhibitors in both plants and mammals. N-(4-Chloro-2-fluoro-5-(propargyloxy)phenyl)-3,4,5,6-tetrahydro phthalimide (a potent protox inhibitor referred to as THP) was synthesized as a candidate radioligand ([3H]-THP) by selective catalytic reduction of 3,6-dihydrophthalic anhydride (DHPA) with tritium gas followed by condensation in 45% yield with 4-chloro-2-fluoro-5-(propargyloxy)aniline. Insertion of tritium at the 3 and 6 carbons of DHPA as well as the expected 4 and 5 carbons resulted in high specific activity [3H]THP (92 Ci/mmol). This radioligand undergoes rapid, specific, saturable, and reversible binding to the inhibitor/herbicide binding site of the protox component of cholate-solubilized mouse liver mitochondria with an apparent Kd of 0.41 nM and Bmax of 0.40 pmol/mg of protein. In the standard assay, mouse preparation (150 micrograms of protein) and [3H]THP (0.5 nM) are incubated in 500 microL of phosphate buffer at pH 7.2 for 15 min at 25 degrees C followed by addition of ammonium sulfate and filtration with glass fiber filters. The potencies of five nitrodiphenyl ethers and two other herbicides as inhibitors of [3H]THP binding correlate well with those for inhibition of protox activity (r2 = 0.97, n = 7), thus validating the binding assay as relevant to enzyme inhibition. It is also suitable to determine in vivo block as illustrated by an approximately 50% decrease in [3H]THP binding in liver mitochondria from mice treated ip with oxyfluorfen at 4 mg/kg. This is the first report of a binding assay for protox in mammals. The high affinity and specific activity of [3H]THP facilitate quantitation of protox and therefore research on a sensitive inhibition site for porphyrin biosynthesis.

  3. Genetic disruption of NRF2 promotes the development of necroinflammation and liver fibrosis in a mouse model of HFE-hereditary hemochromatosis.

    Science.gov (United States)

    Duarte, Tiago L; Caldas, Carolina; Santos, Ana G; Silva-Gomes, Sandro; Santos-Gonçalves, Andreia; Martins, Maria João; Porto, Graça; Lopes, José Manuel

    2017-04-01

    In hereditary hemochromatosis, iron deposition in the liver parenchyma may lead to fibrosis, cirrhosis and hepatocellular carcinoma. Most cases are ascribed to a common mutation in the HFE gene, but the extent of clinical expression is greatly influenced by the combined action of yet unidentified genetic and/or environmental modifying factors. In mice, transcription factor NRF2 is a critical determinant of hepatocyte viability during exposure to acute dietary iron overload. We evaluated if the genetic disruption of Nrf2 would prompt the development of liver damage in Hfe -/- mice (an established model of human HFE-hemochromatosis). Wild-type, Nrf2 -/- , Hfe -/- and double knockout (Hfe/Nrf2 -/- ) female mice on C57BL/6 genetic background were sacrificed at the age of 6 (young), 12-18 (middle-aged) or 24 months (old) for evaluation of liver pathology. Despite the parenchymal iron accumulation, Hfe -/- mice presented no liver injury. The combination of iron overload (Hfe -/- ) and defective antioxidant defences (Nrf2 -/- ) increased the number of iron-related necroinflammatory lesions (sideronecrosis), possibly due to the accumulation of toxic oxidation products such as 4-hydroxy-2-nonenal-protein adducts. The engulfment of dead hepatocytes led to a gradual accumulation of iron within macrophages, featuring large aggregates. Myofibroblasts recruited towards the injury areas produced substantial amounts of collagen fibers involving the liver parenchyma of double-knockout animals with increased hepatic fibrosis in an age-dependent manner. The genetic disruption of Nrf2 promotes the transition from iron accumulation (siderosis) to liver injury in Hfe -/- mice, representing the first demonstration of spontaneous hepatic fibrosis in the long term in a mouse model of hereditary hemochromatosis displaying mildly elevated liver iron. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Autoimmune paediatric liver disease.

    Science.gov (United States)

    Mieli-Vergani, Giorgina; Vergani, Diego

    2008-06-07

    Liver disorders with a likely autoimmune pathogenesis in childhood include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is divided into two subtypes according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1) or liver kidney microsomal antibody (LKM1, type 2). There is a female predominance in both. LKM1 positive patients tend to present more acutely, at a younger age, and commonly have partial IgA deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment, and long-term prognosis are similar in both groups. The most common type of paediatric sclerosing cholangitis is ASC. The clinical, biochemical, immunological, and histological presentation of ASC is often indistinguishable from that of AIH type 1. In both, there are high IgG, non-organ specific autoantibodies, and interface hepatitis. Diagnosis is made by cholangiography. Children with ASC respond to immunosuppression satisfactorily and similarly to AIH in respect to remission and relapse rates, times to normalization of biochemical parameters, and decreased inflammatory activity on follow up liver biopsies. However, the cholangiopathy can progress. There may be evolution from AIH to ASC over the years, despite treatment. De novo AIH after liver transplantation affects patients not transplanted for autoimmune disorders and is strikingly reminiscent of classical AIH, including elevated titres of serum antibodies, hypergammaglobulinaemia, and histological findings of interface hepatitis, bridging fibrosis, and collapse. Like classical AIH, it responds to treatment with prednisolone and azathioprine. De novo AIH post liver transplantation may derive from interference by calcineurin inhibitors with the intrathymic physiological mechanisms of T-cell maturation and selection. Whether this condition is a

  5. Enantioselective metabolism of hydroxychloroquine employing rats and mice hepatic microsomes

    Directory of Open Access Journals (Sweden)

    Carmem Dickow Cardoso

    2009-12-01

    Full Text Available Hydroxychloroquine (HCQ is an important chiral drug used, mainly, in the treatment of rheumatoid arthritis, systemic lupus erythematosus and malaria, and whose pharmacokinetic and pharmacodynamic properties look to be stereoselective. Respecting the pharmacokinetic properties, some previous studies indicate that the stereoselectivity could express itself in the processes of metabolism, distribution and excretion and that the stereoselective metabolism looks to be a function of the studied species. So, the in vitro metabolism of HCQ was investigated using hepatic microsomes of rats and mice. The microsomal fraction of livers of Wistar rats and Balb-C mice was separated by ultracentrifugation and 500 μL were incubated for 180 minutes with 10 μL of racemic HCQ 1000 μg mL-1. Two stereospecific analytical methods, high performance liquid chromatography (HPLC and capillary electrophoresis (CE, were used to separate and quantify the formed metabolites. It was verified that the main formed metabolite is the (--(R-desethyl hydroxychloroquine for both animal species.A hidroxicloroquina (HCQ é um importante fármaco quiral usado, principalmente, no tratamento de artrite reumatóide, lupus eritematoso sistêmico e malária e cujas propriedades farmacocinéticas e farmacodinâmicas parecem ser estereosseletivas. Em relação às propriedades farmacocinéticas, alguns estudos prévios indicam que a estereosseletividade pode se expressar nos processos de metabolismo, distribuição e excreção e que o metabolismo estereosseletivo parece ser função da espécie estudada. Sendo assim, o metabolismo in vitro da HCQ foi investigado usando microssomas de fígado de ratos e de camundongos. A fração microssômica de fígados de ratos Wistar e de camundongos Balb-C foi isolada por ultracentrifugação e 500 μL foram incubados por 180 minutos com 10 μL de HCQ racêmica 1000 μg mL-1. Dois métodos analíticos estereoespecíficos, por cromatografia líquida de

  6. The effects of multiply ionizing gamma irradiations on the xenobiotic metabolizing system in the liver of rats

    International Nuclear Information System (INIS)

    Zavodnik, L.B.; Buko, V.U.

    2009-01-01

    The aim of the work was the studying the effect of multiply low doses of gamma-irradiation in a total doze 1 and 2 Gy on processes lipid peroxidation and xenobiotics metabolizing in rat liver. It was shown the multiply irradiation causes the expressed activation of lipid peroxidation, by increase of TBARS level and dien conjugates. The system of microsomal oxidations was broken at the same time. (authors)

  7. Moderate activation of IKK2-NF-kB in unstressed adult mouse liver induces cytoprotective genes and lipogenesis without apparent signs of inflammation or fibrosis.

    Science.gov (United States)

    Lu, Hong; Lei, Xiaohong; Zhang, Qinghao

    2015-07-30

    The NF-kB signaling, regulated by IKK1-p52/RelB and IKK2-p65, is activated by various stresses to protect or damage the liver, in context-specific manners. Two previous studies of liver-specific expression of constitutive active IKK2 (IKK2ca) showed that strong activation of IKK2-NF-kB in mouse livers caused inflammation, insulin resistance, and/or fibrosis. The purpose of this study was to understand how moderate activation of IKK2-NF-kB in adult mouse livers alters hepatic gene expression and pathophysiology. We generated mice with adult hepatocyte-specific activation of Ikk2 (Liv-Ikk2ca) using Alb-cre mice and Ikk2ca Rosa26 knockin mice in which a moderate expression of Ikk2ca transgene was driven by the endogenous Rosa26 promoter. Surprisingly, compared to wild-type mice, adult male Liv-Ikk2ca mice had higher hepatic mRNA expression of Ikk2 and classical NF-kB targets (e.g. Lcn2 and A20), as well as IKK1, NIK, and RelB, but no changes in markers of inflammation or fibrosis. Blood levels of IL-6 and MCP-1 remained unchanged, and histology analysis showed a lack of injury or infiltration of inflammatory cells in livers of Liv-Ikk2ca mice. Moreover, Liv-Ikk2ca mice had lower mRNA expression of prooxidative enzymes Cyp2e1 and Cyp4a14, higher expression of antioxidative enzymes Sod2, Gpx1, and Nqo1, without changes in key enzymes for fatty acid oxidation, glucose utilization, or gluconeogenesis. In parallel, Liv-Ikk2ca mice and wild-type mice had similar levels of hepatic reduced glutathione, endogenous reactive oxygen species, and lipid peroxidation. Additionally, Liv-Ikk2ca mice had higher Cyp3a11 without down-regulation of most drug processing genes. Regarding nuclear proteins of NF-kB subunits, Liv-Ikk2ca mice had moderately higher p65 and p50 but much higher RelB. Results of ChIP-qPCR showed that the binding of p50 to multiple NF-kB-target genes was markedly increased in Liv-Ikk2ca mice. Additionally, Liv-Ikk2ca mice had moderate increase in triglycerides in

  8. Inhibition of tumor necrosis factor alpha reduces the outgrowth of hepatic micrometastasis of colorectal tumors in a mouse model of liver ischemia-reperfusion injury.

    Science.gov (United States)

    Jiao, Shu-Fan; Sun, Kai; Chen, Xiao-Jing; Zhao, Xue; Cai, Ning; Liu, Yan-Jun; Xu, Long-Mei; Kong, Xian-Ming; Wei, Li-Xin

    2014-01-08

    Patients with colorectal cancer (CRC) often develop liver metastases, in which case surgery is considered the only potentially curative treatment option. However, liver surgery is associated with a risk of ischemia-reperfusion (IR) injury, which is thought to promote the growth of colorectal liver metastases. The influence of IR-induced tumor necrosis factor alpha (TNF-α) elevation in the process still is unknown. To investigate the role of TNF-α in the growth of pre-existing micrometastases in the liver following IR, we used a mouse model of colorectal liver metastases. In this model, mice received IR treatment seven days after intrasplenic injections of colorectal CT26 cells. Prior to IR treatment, either TNF-α blocker Enbrel or low-dose TNF-α, which could inhibit IR-induced TNF-α elevation, was administered by intraperitoneal injection. Hepatic IR treatment significantly promoted CT26 tumor growth in the liver, but either Enbrel or low-dose TNF-α pretreatment reversed this trend. Further studies showed that the CT26 + IR group prominently increased the levels of ALT and AST, liver necrosis, inflammatory infiltration and the expressions of hepatic IL-6, MMP9 and E-selectin compared to those of CT26 group. Inhibition of TNF-α elevation remarkably attenuated the increases of these liver inflammatory damage indicators and tumor-promoting factors. These findings suggested that inhibition of TNF-α elevation delayed the IR-enhanced outgrowth of colorectal liver metastases by reducing IR-induced inflammatory damage and the formation of tumor-promoting microenvironments. Both Enbrel and low-dose TNF-α represented the potential therapeutic approaches for the protection of colorectal liver metastatic patients against IR injury-induced growth of liver micrometastases foci.

  9. Metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Ohhira, Shuji; Watanabe, Masatomo; Matsui, Hisao [Department of Hygiene, Dokkyo University School of Medicine, Mibu-machi, 321-0293, Tochigi (Japan)

    2003-03-01

    Tributyltin and triphenyltin are metabolized by cytochrome P-450 system enzymes, and their metabolic fate may contribute to the toxicity of the chemicals. In the current study, the in vitro metabolism of tributyltin and triphenyltin by rat, hamster and human hepatic microsomes was investigated to elucidate the metabolic competence for these compounds in humans. The metabolic reaction using microsome-NADPH system that is usually conducted was not applicable to in vitro metabolism of organotins, especially triphenyltin. We therefore examined the effects of dithiothreitol (DTT), one of the antioxidants for sulfhydryl groups, to determine the in vitro metabolism of tributyltin and triphenyltin. As a result, the treatment with 0.1 mM DTT in vitro increased the activity of the microsomal monooxygenase system for metabolism of tributyltin as well as triphenyltin; the total yield of tributyltin and triphenyltin metabolites as tin increased, respectively, by approximately 1.8 and 8.9 times for rat, 2.1 and 1.2 times for hamster, and 1.6 and 1.5 times for human. It is suggested that the organotins directly inactivate cytochrome P-450 because of the interaction with critical sulfhydryl groups of the hemoprotein. We confirmed the utility of this in vitro metabolic system using DTT in the hepatic microsomes of phenobarbital (PB)-pretreated and untreated hamsters. Thus, the in vitro metabolic system described here was applied to a comparative study of the metabolism of organotins in rats, hamsters and humans. Tributyltin was metabolized more readily than triphenyltin in all the species. In humans, the in vitro metabolic pattern resembled that of hamsters, which were susceptible to in vivo triphenyltin toxicity because of incompetent metabolism. It is possible that the hamster is a qualitatively and quantitatively suitable animal model for exploring the influence of tributyltin and triphenyltin in humans. (orig.)

  10. Effect of p-amino-diphenyl ethers on hepatic microsomal cytochrome P450.

    Science.gov (United States)

    Jiang, Huidi; Xuan, Guida

    2003-09-01

    The present paper aims to investigate whether p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450. Mice were given daily intraperitoneal (ip) injections of p-amino-2',4'-dichlorodiphenyl ether (0.25 mmol/kg) or p-amino-4'-methyldiphenyl ether (0.25 mmol/kg) for 4 days and tested at 24 h and 48 h after the last dose injection. The results showed the mice pentobarbital sleeping time was shorter and the P450 content of hepatic microsome increased significantly in the group pretreated with p-amino-4'-methyldiphenyl ether when compared with the control group, while in mice pretreated with p-amino-2',4'-dichlorodiphenyl ether the hepatic microsome P450 content increased but the pentobarbital sleeping time was extended in clear contrast to the control group. The sleeping time of the phenobarbital group (80 mg/kg daily ip injection for 4 days) was shortened at 24 h after the last injection with increased P450 content of hepatic microsome, but it showed no difference at 48 h. The zoxazolamine-paralysis times of mice treated with p-amino-2',4'-dichlorodiphenyl ether were longer than those of the control mice, while the same dose of zoxazolamine did not lead to paralysis in mice pretreated with BNF. p-Amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether inhibited the activity of 7-ethoxyresorufin O-deethylase from rat hepatic microsome induced by BNF in vitro by 70.0% and 50.1% respectively. These results suggest that p-amino-2',4'-dichlorodiphenyl ether and p-amino-4'-methyldiphenyl ether are inhibitors as well as inducers of P450.

  11. Enzymes and Inhibitors in Neonicotinoid Insecticide Metabolism

    Science.gov (United States)

    Shi, Xueyan; Dick, Ryan A.; Ford, Kevin A.; Casida, John E.

    2009-01-01

    Neonicotinoid insecticide metabolism involves considerable substrate specificity and regioselectivity of the relevant CYP450, aldehyde oxidase, and phase II enzymes. Human CYP450 recombinant enzymes carry out the following conversions: CYP3A4, 2C19 and 2B6 for thiamethoxam (TMX) to clothianidin (CLO); 3A4, 2C19 and 2A6 for CLO to desmethyl-CLO; 2C19 for TMX to desmethyl-TMX. Human liver aldehyde oxidase reduces the nitro substituent of CLO to nitroso much more rapidly than that of TMX. Imidacloprid (IMI), CLO and several of their metabolites do not give detectable N-glucuronides but 5-hydroxy-IMI, 4,5-diol-IMI and 4-hydroxy-thiacloprid are converted to O-glucuronides in vitro with mouse liver microsomes and UDP-glucuronic acid or in vivo in mice. Mouse liver cytosol with S-adenosylmethionine converts desmethyl-CLO to CLO but not desmethyl-TMX to TMX. Two organophosphorus CYP450 inhibitors partially block IMI, thiacloprid and CLO metabolism in vivo in mice, elevating the brain and liver levels of the parent compounds while reducing amounts of the hydroxylated metabolites. PMID:19391582

  12. Identification and analysis of cytochrome P450IID6 antigenic sites recognized by anti-liver-kidney microsome type-1 antibodies (LKM1).

    Science.gov (United States)

    Yamamoto, A M; Cresteil, D; Boniface, O; Clerc, F F; Alvarez, F

    1993-05-01

    Anti-liver-kidney microsome type-1 antibodies (LKM1), present in sera from a group of patients with autoimmune hepatitis, are directed against P450IID6. Previous work, using cDNA constructions spanning most of the P450IID6 protein defined the main immunogenic site between the amino acids (aa), 254-271 and predicted the presence of other putative immunogenic sites in the molecule. Fusion proteins from new cDNA constructions, spanning so-far-untested regions between aa 1-125 and 431-522, were not recognized by LKM1-positive sera. Synthetic peptides, representing sequences from putative immunogenic regions or previously untested regions, allowed a precise definition of four antigenic sites located between peptides 257-269, 321-351, 373-389 and 410-429, which were recognized, respectively, by 14, 8, 1 and 2 out of 15 LKM1-positive sera tested. The minimal sequence of the main antigenic site (peptide 257-269) recognized by the autoantibody was established to be WDPAQPPRD (peptide 262-270). In addition, deletion and replacement experiments showed that aa 263 (Asp) was essential for the binding of the autoantibody to peptide 262-270. Analysis of the second most frequently recognized peptide between aa 321-351, was performed using peptides 321-339 and 340-351 in competitive inhibition studies. Complete elimination of antibody binding to peptide 321-351 obtained by absorption of both shorter peptides indicated that peptide 321-351 is a discontinuous antigenic site. LKM1-positive sera reacting against peptide 321-351 recognized either both the shorter peptides or just one of them preferentially. Results of the present study suggest that the production of LKM1 antibodies is an antigen-driven, poly- or oligoclonal B cell response. The identification of antigenic sites will allow: (i) the development of specific diagnostic tests and (ii) further studies on the pathogenic value of LKM1 antibodies in autoimmune hepatitis.

  13. Effect of a New Prokinetic Agent DA-9701 Formulated with Corydalis Tuber and Pharbitidis Semen on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Hye Young Ji

    2012-01-01

    Full Text Available DA-9701 is a new botanical drug composed of the extracts of Corydalis tuber and Pharbitidis semen, and it is used as an oral therapy for the treatment of functional dyspepsia in Korea. The inhibitory potentials of DA-9701 and its component herbs, Corydalis tuber and Pharbitidis semen, on the activities of seven major human cytochrome P450 (CYP enzymes and four UDP-glucuronosyltransferase (UGT enzymes in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. DA-9701 and Corydalis tuber extract slightly inhibited UGT1A1-mediated etoposide glucuronidation, with 50% inhibitory concentration (IC50 values of 188 and 290 μg/mL, respectively. DA-9701 inhibited CYP2D6-catalyzed bufuralol 1′-hydroxylation with an inhibition constant (Ki value of 6.3 μg/mL in a noncompetitive manner. Corydalis tuber extract competitively inhibited CYP2D6-mediated bufuralol 1′-hydroxylation, with a Ki value of 3.7 μg/mL, whereas Pharbitidis semen extract showed no inhibition. The volume in which the dose could be diluted to generate an IC50 equivalent concentration (volume per dose index value of DA-9701 for inhibition of CYP2D6 activity was 1.16 L/dose, indicating that DA-9701 may not be a potent CYP2D6 inhibitor. Further clinical studies are warranted to evaluate the in vivo extent of the observed in vitro interactions.

  14. Genotoxicity of 3-nitrobenzanthrone and 3-aminobenzanthrone in MutaMouse and lung epithelial cells derived from MutaMouse.

    Science.gov (United States)

    Arlt, Volker M; Gingerich, John; Schmeiser, Heinz H; Phillips, David H; Douglas, George R; White, Paul A

    2008-11-01

    FE1 lung epithelial cells derived from MutaMouse are a new model system to provide in vitro mutagenicity data with the potential to predict the outcome of an in vivo MutaMouse test. 3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and urban air pollution. We investigated the mutagenicity and DNA binding of 3-NBA and its main metabolite 3-aminobenzanthrone (3-ABA) in vitro and in vivo in the MutaMouse assay. Mice were treated with 3-NBA or 3-ABA (0, 2 or 5 mg/kg body weight/day) by gavage for 28 days and 28 days later lacZ mutant frequency (MF) was determined in liver, lung and bone marrow. For both compounds, dose-related increases in MF were seen in liver and bone marrow, but not in lung; mutagenic activity was approximately 2-fold lower for 3-ABA than for 3-NBA. With 3-NBA, highest DNA adduct levels (measured by (32)P-post-labelling) were found in liver (approximately 230 adducts per 10(8) nucleotides) with levels 20- to 40-fold lower in bone marrow and lung. With 3-ABA, DNA adduct levels were again highest in the liver, but approximately 4-fold lower than for 3-NBA. FE1 cells were exposed to up to 10 microg/ml 3-NBA or 3-ABA for 6 h with or without exogenous activation (S9) and harvested after 3 days. For 3-NBA, there was a dose-related increase in MF both with and without S9 mix, which was >10 times higher than observed in vivo. At the highest concentration of 3-ABA (10 microg/ml), we found only around a 2-fold increase in MF relative to controls. DNA adduct formation in FE1 cells was dose-dependent for both compounds, but 10- to 20-fold higher for 3-NBA compared to 3-ABA. Collectively, our data indicate that MutaMouse FE1 cells are well suited for cost-effective testing of suspected mutagens with different metabolic activation pathways as a guide for subsequent in vivo MutaMouse testing.

  15. Etiology of fatty liver in dairy cattle: effects of nutritional and hormonal status on hepatic microsomal triglyceride transfer protein.

    Science.gov (United States)

    Bremmer, D R; Trower, S L; Bertics, S J; Besong, S A; Bernabucci, U; Grummer, R R

    2000-10-01

    We conducted three experiments to determine the effects of nutritional and hormonal status on microsomal triglyceride transfer protein (MTP) activity and mass. In experiment 1, 18 nonlactating Holstein cows, 75 d before expected calving date, in their second gestation or greater were monitored from d 75 to 55 prepartum. Cows were fed a control diet from d 75 to 62 prepartum for covariable measurements. From d 61 to 55 prepartum, six cows continued to receive the control diet, six cows were restricted to 2.3 kg of grass hay/d, and six cows were fed the control diet plus 1.8 kg of concentrate/d and 500 ml of propylene glycol given 2 times/d as an oral drench. Plasma glucose and serum insulin concentrations were highest in cows that received propylene glycol and lowest in feed restricted cows. Plasma nonesterified fatty acids (NEFA) and liver triglyceride (TG) concentrations were highest in feed restricted cows and not different between cows that received the control diet and cows that received propylene glycol. Hepatic MTP activity and mass were not affected by treatment in experiment 1. In experiment 2, bovine hepatocytes isolated from the caudate process of five preruminating Holstein bull calves were incubated with either 0, 0.5, 1.0, or 2.0 mM NEFA for 48 h. Intracellular TG increased linearly as NEFA concentration in the media increased. Concentration of NEFA in the incubation media had no effect on MTP activity or mass. There was a quadratic effect of concentration of NEFA in the incubation media on MTP mRNA. In experiment 3, bovine hepatocytes isolated from the caudate process of five preruminating Holstein bull calves were incubated with 2 mM [1-14C]oleate for 24 h to accumulate TG, followed by a 36-h period of TG depletion, during which hepatocytes were incubated with no hormone, 10 nM insulin, or 10 nM glucagon. There was no effect of insulin or glucagon on intracellular TG, MTP activity or mass. Cells incubated with no hormone had higher levels of MTP m

  16. In vitro biotransformation of tris(2-butoxyethyl) phosphate (TBOEP) in human liver and serum

    Energy Technology Data Exchange (ETDEWEB)

    Van den Eede, Nele, E-mail: nele.vandeneede@uantwerpen.be [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Erratico, Claudio [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Exarchou, Vassiliki [Natural Products & Food Research and Analysis (NatuRA), Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Maho, Walid; Neels, Hugo [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium); Covaci, Adrian, E-mail: adrian.covaci@uantwerpen.be [Toxicological Center, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Antwerp (Belgium)

    2015-04-15

    Tris(2-butoxyethyl) phosphate (TBOEP) is a plasticizer present in indoor dust, reaching levels of several micrograms per gram. Such levels could lead to significant daily exposure of adults and children. Currently, no toxicokinetic data are available to estimate TBOEP clearance in humans after uptake and therefore, one objective of this study was to investigate intrinsic clearance of TBOEP by human liver microsome (HLM) and serum enzymes. Another objective was to generate information to identify and prioritize several metabolites of TBOEP for investigation of human exposure by biomonitoring. 1D and 2D-NMR methodologies were successfully applied on a mixture of the metabolites to confirm the structure of 3-HO-TBOEP (bis(2-butoxyethyl) 3-hydroxyl-2-butoxyethyl phosphate) and to tentatively assign structures to 1-HO-TBOEP and 2-HO-TBOEP. HO-TBOEP isomers and bis(2-butoxyethyl) phosphate (BBOEP), bis(2-butoxyethyl) hydroxyethyl phosphate (BBOEHEP) were further monitored by liquid chromatography–tandem mass spectrometry. Rates of formation of BBOEHEP and HO-TBOEP metabolites by liver enzymes were best described by the Michaelis–Menten model. Apparent K{sub m} values for BBOEHEP, 3-HO-TBOEP, and sum of 1- and 2-HO-TBOEP isomer formation were 152, 197 and 148 μM, respectively. Apparent V{sub max} values for the formation of BBOEHEP, 3-HO-TBOEP, and the sum of 1- and 2-HO-TBOEP isomers were 2560, 643, and 254 pmol/min/mg protein, respectively. No detectable formation of BBOEP occurred with liver or serum enzymes. Our findings indicate that intrinsic clearance of TBOEP is mainly catalyzed by oxidative enzymes in the liver and that its major in vitro metabolite is BBOEHEP. These findings can be applied in human biomonitoring studies and risk assessment. - Highlights: • First steps in the elucidation of TBOEP toxicokinetics • Quantification of TBOEP metabolites in human serum and liver microsomes • No detectable formation of BBOEP occurred with liver or serum

  17. CRISPR/Cas9 Engineering of Adult Mouse Liver Demonstrates That the Dnajb1-Prkaca Gene Fusion Is Sufficient to Induce Tumors Resembling Fibrolamellar Hepatocellular Carcinoma.

    Science.gov (United States)

    Engelholm, Lars H; Riaz, Anjum; Serra, Denise; Dagnæs-Hansen, Frederik; Johansen, Jens V; Santoni-Rugiu, Eric; Hansen, Steen H; Niola, Francesco; Frödin, Morten

    2017-12-01

    Fibrolamellar hepatocellular carcinoma (FL-HCC) is a primary liver cancer that predominantly affects children and young adults with no underlying liver disease. A somatic, 400 Kb deletion on chromosome 19 that fuses part of the DnaJ heat shock protein family (Hsp40) member B1 gene (DNAJB1) to the protein kinase cAMP-activated catalytic subunit alpha gene (PRKACA) has been repeatedly identified in patients with FL-HCC. However, the DNAJB1-PRKACA gene fusion has not been shown to induce liver tumorigenesis. We used the CRISPR/Cas9 technique to delete in mice the syntenic region on chromosome 8 to create a Dnajb1-Prkaca fusion and monitored the mice for liver tumor development. We delivered CRISPR/Cas9 vectors designed to juxtapose exon 1 of Dnajb1 with exon 2 of Prkaca to create the Dnajb1-Prkaca gene fusion associated with FL-HCC, or control Cas9 vector, via hydrodynamic tail vein injection to livers of 8-week-old female FVB/N mice. These mice did not have any other engineered genetic alterations and were not exposed to liver toxins or carcinogens. Liver tissues were collected 14 months after delivery; genomic DNA was analyzed by PCR to detect the Dnajb1-Prkaca fusion, and tissues were characterized by histology, immunohistochemistry, RNA sequencing, and whole-exome sequencing. Livers from 12 of the 15 mice given the vectors to induce the Dnajb1-Prkaca gene fusion, but none of the 11 mice given the control vector, developed neoplasms. The tumors contained the Dnajb1-Prkaca gene fusion and had histologic and cytologic features of human FL-HCCs: large polygonal cells with granular, eosinophilic, and mitochondria-rich cytoplasm, prominent nucleoli, and markers of hepatocytes and cholangiocytes. In comparing expression levels of genes between the mouse tumor and non-tumor liver cells, we identified changes similar to those detected in human FL-HCC, which included genes that affect cell cycle and mitosis regulation. Genomic analysis of mouse neoplasms induced by

  18. Anti-CD25 mAb administration prevents spontaneous liver transplant tolerance.

    Science.gov (United States)

    Li, W; Carper, K; Liang, Y; Zheng, X X; Kuhr, C S; Reyes, J D; Perkins, D L; Thomson, A W; Perkins, J D

    2006-12-01

    Liver allografts are accepted spontaneously in all mouse strain combinations without immunosuppressive therapy. The mechanisms underlying this phenomenon remain largely undefined. In this study, we examined the effect of CD4+ CD25+ T regulatory cells (Treg) on the induction of mouse liver transplant tolerance. Orthotopic liver transplantation was performed from B10 (H2b) to C3H (H2k) mice. Depleting rat anti-mouse CD25 mAb (PC61) was given to the donors or recipients (250 microg/d IP) pretransplant or to the recipients postoperatively. At day 5 posttransplantation, both effector T cells (mainly CD8) and CD4+ CD25+ Treg were increased in the liver allografts and host spleens compared to naïve mice. Anti-CD25 mAb administration, either pretransplantation or posttransplantation, reduced the ratio of CD4+ CD25+ Treg to the CD3 T cells of liver grafts and recipient spleens and induced liver allograft acute rejection compared to IgG treatment. Anti-CD25 mAb administration elevated anti-donor T-cell proliferative responses and CTL and NK activities of graft infiltrates and host splenocytes; reduced CTLA4, Foxp3, and IDO mRNA levels; increased IL-10 and IFN-gamma; and decreased IL-4 mRNA levels in the livers or host spleens. The number of apoptotic T cells was reduced significantly in the liver grafts and treated host spleens. Therefore, anti-CD25 mAb administration changed the balance of CD4+ CD25+ Treg to activated T cells of liver graft recipients, preventing liver transplant tolerance. This was associated with enhanced anti-donor immune reactivity, downregulated Treg gene expression, and reduced T cell apoptosis in the grafts and host spleens.

  19. NMR-based Metabolomics Analysis of Liver from C57BL/6 Mouse Exposed to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Xiongjie [Pacific Northwest National Laboratory, Richland, Washington 99352; State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, China; Hu, Mary [Pacific Northwest National Laboratory, Richland, Washington 99352; Zhang, Xu [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, PR China; Hu, Jian Zhi [Pacific Northwest National Laboratory, Richland, Washington 99352

    2017-07-01

    The health effects of exposing to ionizing radiation are attracting great interest in the space exploration community and patients considering radiotherapy. However, the impact to metabolism after exposure to high dose radiation has not yet been clearly defined in livers. In the present study, 1H nuclear magnetic resonance (NMR) based metabolomics combined with multivariate data analysis are applied to study the changes of metabolism in the liver of C57BL/6 mouse after whole body exposure to either gamma (3.0 and 7.8 Gy) or proton (3.0 Gy) radiation. Principal component analysis (PCA) and orthogonal projection to latent structures analysis (OPLS) are employed for classification and identification of potential biomarkers associated with gamma and proton irradiation. The results show that the radiation exposed groups can be well separated from the control group. At the same radiation dosage, the group exposed to proton radiation is well separated from the group exposed to gamma radiation, indicating different radiation sources induce different alterations based on metabolic profiling. Common to both gamma and proton radiation at the high radiation doses studied in this work, compared with the control groups the concentrations of choline, O-phosphocholine and trimethylamine N-oxide are decreased statistically, while those of glutamine, glutathione, malate, creatinine, phosphate, betaine and 4-hydroxyphenylacetate are statistically and significantly elevated after exposure to radiation. Since these altered metabolites are associated with multiple biological pathways, the changes suggest that the exposure to radiation induce abnormality in multiple biological pathways. In particular, metabolites such as 4-hydroxyphenylacetate, betaine, glutamine, choline and trimethylamine N-oxide may be good candidates of pre-diagnose biomarkers for ionizing radiation in liver.

  20. Night-time restricted feeding normalises clock genes and Pai-1 gene expression in the db/db mouse liver.

    Science.gov (United States)

    Kudo, T; Akiyama, M; Kuriyama, K; Sudo, M; Moriya, T; Shibata, S

    2004-08-01

    An increase in PAI-1 activity is thought to be a key factor underlying myocardial infarction. Mouse Pai-1 (mPai-1) activity shows a daily rhythm in vivo, and its transcription seems to be controlled not only by clock genes but also by humoral factors such as insulin and triglycerides. Thus, we investigated daily clock genes and mPai-1 mRNA expression in the liver of db/db mice exhibiting high levels of glucose, insulin and triglycerides. Locomotor activity was measured using an infrared detection system. RT-PCR or in situ hybridisation methods were applied to measure gene expression. Humoral factors were measured using measurement kits. The db/ db mice showed attenuated locomotor activity rhythms. The rhythmic expression of mPer2 mRNA was severely diminished and the phase of mBmal1 oscillation was advanced in the db/db mouse liver, whereas mPai-1 mRNA was highly and constitutively expressed. Night-time restricted feeding led to a recovery not only from the diminished locomotor activity, but also from the diminished Per2 and advanced mBmal1 mRNA rhythms. Expression of mPai-1 mRNA in db/db mice was reduced to levels far below normal. Pioglitazone treatment slightly normalised glucose and insulin levels, with a slight reduction in mPai-1 gene expression. We demonstrated that Type 2 diabetes impairs the oscillation of the peripheral oscillator. Night-time restricted feeding rather than pioglitazone injection led to a recovery from the diminished locomotor activity, and altered oscillation of the peripheral clock and mPai-1 mRNA rhythm. Thus, we conclude that scheduled restricted food intake may be a useful form of treatment for diabetes.

  1. Automation of metabolic stability studies in microsomes, cytosol and plasma using a 215 Gilson liquid handler.

    Science.gov (United States)

    Linget, J M; du Vignaud, P

    1999-05-01

    A 215 Gilson liquid handler was used to automate enzymatic incubations using microsomes, cytosol and plasma. The design of automated protocols are described. They were based on the use of 96 deep well plates and on HPLC-based methods for assaying the substrate. The assessment of those protocols was made with comparison between manual and automated incubations, reliability and reproducibility of automated incubations in microsomes and cytosol. Examples of the use of those programs in metabolic studies in drug research, i.e. metabolic screening in microsomes and plasma were shown. Even rapid processes (with disappearance half lives as low as 1 min) can be analysed. This work demonstrates how stability studies can be automated to save time, render experiments involving human biological media less hazardous and may be improve inter-laboratory reproducibility.

  2. The nutritional geometry of liver disease including non-alcoholic fatty liver disease.

    Science.gov (United States)

    Simpson, Stephen J; Raubenheimer, David; Cogger, Victoria C; Macia, Laurence; Solon-Biet, Samantha M; Le Couteur, David G; George, Jacob

    2018-02-01

    Nutrition has a profound effect on chronic liver disease, especially non-alcoholic fatty liver disease (NAFLD). Most observational studies and clinical trials have focussed on the effects of total energy intake, or the intake of individual macronutrients and certain micronutrients, such as vitamin D, on liver disease. Although these studies have shown the importance of nutrition on hepatic outcomes, there is not yet any unifying framework for understanding the relationship between diet and liver disease. The Geometric Framework for Nutrition (GFN) is an innovative model for designing nutritional experiments or interpreting nutritional data that can determine the effects of nutrients and their interactions on animal behaviour and phenotypes. Recently the GFN has provided insights into the relationship between dietary energy and macronutrients on obesity and ageing in mammals including humans. Mouse studies using the GFN have disentangled the effects of macronutrients on fatty liver and the gut microbiome. The GFN is likely to play a significant role in disentangling the effects of nutrients on liver disease, especially NAFLD, in humans. Copyright © 2017 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  3. Development of achiral and chiral 2D HPLC methods for analysis of albendazole metabolites in microsomal fractions using multivariate analysis for the in vitro metabolism.

    Science.gov (United States)

    Belaz, Kátia Roberta A; Pereira-Filho, Edenir Rodrigues; Oliveira, Regina V

    2013-08-01

    In this work, the development of two multidimensional liquid chromatography methods coupled to a fluorescence detector is described for direct analysis of microsomal fractions obtained from rat livers. The chiral multidimensional method was then applied for the optimization of the in vitro metabolism of albendazole by experimental design. Albendazole was selected as a model drug because of its anthelmintics properties and recent potential for cancer treatment. The development of two fully automated achiral-chiral and chiral-chiral high performance liquid chromatography (HPLC) methods for the determination of albendazole (ABZ) and its metabolites albendazole sulphoxide (ABZ-SO), albendazole sulphone (ABZ-SO2) and albendazole 2-aminosulphone (ABZ-SO2NH2) in microsomal fractions are described. These methods involve the use of a phenyl (RAM-phenyl-BSA) or octyl (RAM-C8-BSA) restricted access media bovine serum albumin column for the sample clean-up, followed by an achiral phenyl column (15.0×0.46cmI.D.) or a chiral amylose tris(3,5-dimethylphenylcarbamate) column (15.0×0.46cmI.D.). The chiral 2D HPLC method was applied to the development of a compromise condition for the in vitro metabolism of ABZ by means of experimental design involving multivariate analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Liver cytosolic 1 antigen-antibody system in type 2 autoimmune hepatitis and hepatitis C virus infection.

    Science.gov (United States)

    Lenzi, M; Manotti, P; Muratori, L; Cataleta, M; Ballardini, G; Cassani, F; Bianchi, F B

    1995-01-01

    Within the multiform liver/kidney microsomal (LKM) family, a subgroup of sera that reacts with a liver cytosolic (LC) protein has been isolated and the new antigen-antibody system is called LC1. Unlike LKM antibody type 1 (anti-LKM1), anti-LC1 is said to be unrelated to hepatitis C virus (HCV) infection and has therefore been proposed as a marker of 'true' autoimmune hepatitis type 2. Altogether 100 LKM1 positive sera were tested by immunodiffusion (ID). Twenty five gave a precipitation line with human liver cytosol; 17 of the 25 also reacted with rat liver cytosol. Thirteen of the 25 sera were anti-HCV positive by second generation ELISA: anti-HCV positive patients were significantly older (p LKM1, and that it is an additional marker of juvenile autoimmune hepatitis type 2. It does not, however, discriminate between patients with and without HCV infection. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7797126

  5. Clearance Prediction Methodology Needs Fundamental Improvement: Trends Common to Rat and Human Hepatocytes/Microsomes and Implications for Experimental Methodology.

    Science.gov (United States)

    Wood, F L; Houston, J B; Hallifax, D

    2017-11-01

    Although prediction of clearance using hepatocytes and liver microsomes has long played a decisive role in drug discovery, it is widely acknowledged that reliably accurate prediction is not yet achievable despite the predominance of hepatically cleared drugs. Physiologically mechanistic methodology tends to underpredict clearance by several fold, and empirical correction of this bias is confounded by imprecision across drugs. Understanding the causes of prediction uncertainty has been slow, possibly reflecting poor resolution of variables associated with donor source and experimental methods, particularly for the human situation. It has been reported that among published human hepatocyte predictions there was a tendency for underprediction to increase with increasing in vivo intrinsic clearance, suggesting an inherent limitation using this particular system. This implied an artifactual rate limitation in vitro, although preparative effects on cell stability and performance were not yet resolved from assay design limitations. Here, to resolve these issues further, we present an up-to-date and comprehensive examination of predictions from published rat as well as human studies (where n = 128 and 101 hepatocytes and n = 71 and 83 microsomes, respectively) to assess system performance more independently. We report a clear trend of increasing underprediction with increasing in vivo intrinsic clearance, which is similar both between species and between in vitro systems. Hence, prior concerns arising specifically from human in vitro systems may be unfounded and the focus of investigation in the future should be to minimize the potential in vitro assay limitations common to whole cells and subcellular fractions. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  6. Ozagrel hydrochloride, a selective thromboxane A2 synthase inhibitor, alleviates liver injury induced by acetaminophen overdose in mice

    Directory of Open Access Journals (Sweden)

    Tomishima Yoshiro

    2013-01-01

    Full Text Available Abstract Background Overdosed acetaminophen (paracetamol, N-acetyl-p-aminophenol; APAP causes severe liver injury. We examined the effects of ozagrel, a selective thromboxane A2 (TXA2 synthase inhibitor, on liver injury induced by APAP overdose in mice. Methods Hepatotoxicity was induced to ICR male mice by an intraperitoneal injection with APAP (330 mg/kg. The effects of ozagrel (200 mg/kg treatment 30 min after the APAP injection were evaluated with mortality, serum alanine aminotransferase (ALT levels and hepatic changes, including histopathology, DNA fragmentation, mRNA expression and total glutathione contents. The impact of ozagrel (0.001-1 mg/mL on cytochrome P450 2E1 (CYP2E1 activity in mouse hepatic microsome was examined. RLC-16 cells, a rat hepatocytes cell line, were exposed to 0.25 mM N-acetyl-p-benzoquinone imine (NAPQI, a hepatotoxic metabolite of APAP. In this model, the cytoprotective effects of ozagrel (1–100 muM were evaluated by the WST-1 cell viability assay. Results Ozagel treatment significantly attenuated higher mortality, elevated serum alanine aminotransferase levels, excessive hepatic centrilobular necrosis, hemorrhaging and DNA fragmentation, as well as increase in plasma 2,3-dinor thromboxane B2 levels induced by APAP injection. Ozagrel also inhibited the hepatic expression of cell death-related mRNAs induced by APAP, such as jun oncogene, FBJ osteosarcoma oncogene (fos and C/EBP homologous protein (chop, but did not suppress B-cell lymphoma 2-like protein11 (bim expression and hepatic total glutathione depletion. These results show ozagrel can inhibit not all hepatic changes but can reduce the hepatic necrosis. Ozagrel had little impact on CYP2E1 activity involving the NAPQI production. In addition, ozagrel significantly attenuated cell injury induced by NAPQI in RLC-16. Conclusions We demonstrate that the TXA2 synthase inhibitor, ozagrel, dramatically alleviates liver injury induced by APAP in mice, and suggest

  7. Cytochrome P450 2C8 and flavin-containing monooxygenases are involved in the metabolism of tazarotenic acid in humans.

    Science.gov (United States)

    Attar, Mayssa; Dong, Dahai; Ling, Kah-Hiing John; Tang-Liu, Diane D-S

    2003-04-01

    Upon oral administration, tazarotene is rapidly converted to tazarotenic acid by esterases. The main circulating agent, tazarotenic acid is subsequently oxidized to the inactive sulfoxide metabolite. Therefore, alterations in the metabolic clearance of tazarotenic acid may have significant effects on its systemic exposure. The objective of this study was to identify the human liver microsomal enzymes responsible for the in vitro metabolism of tazarotenic acid. Tazarotenic acid was incubated with 1 mg/ml pooled human liver microsomes, in 100 mM potassium phosphate buffer (pH 7.4), at 37 degrees C, over a period of 30 min. The microsomal enzymes that may be involved in tazarotenic acid metabolism were identified through incubation with microsomes containing cDNA-expressed human microsomal isozymes. Chemical inhibition studies were then conducted to confirm the identity of the enzymes potentially involved in tazarotenic acid metabolism. Reversed-phase high performance liquid chromatography was used to quantify the sulfoxide metabolite, the major metabolite of tazarotenic acid. Upon incubation of tazarotenic acid with microsomes expressing CYP2C8, flavin-containing monooxygenase 1 (FMO1), or FMO3, marked formation of the sulfoxide metabolite was observed. The involvement of these isozymes in tazarotenic acid metabolism was further confirmed by inhibition of metabolite formation in pooled human liver microsomes by specific inhibitors of CYP2C8 or FMO. In conclusion, the in vitro metabolism of tazarotenic acid to its sulfoxide metabolite in human liver microsomes is mediated by CYP2C8 and FMO.

  8. Complete Plasmodium falciparum liver-stage development in liver-chimeric mice

    Science.gov (United States)

    Vaughan, Ashley M.; Mikolajczak, Sebastian A.; Wilson, Elizabeth M.; Grompe, Markus; Kaushansky, Alexis; Camargo, Nelly; Bial, John; Ploss, Alexander; Kappe, Stefan H.I.

    2012-01-01

    Plasmodium falciparum, which causes the most lethal form of human malaria, replicates in the host liver during the initial stage of infection. However, in vivo malaria liver-stage (LS) studies in humans are virtually impossible, and in vitro models of LS development do not reconstitute relevant parasite growth conditions. To overcome these obstacles, we have adopted a robust mouse model for the study of P. falciparum LS in vivo: the immunocompromised and fumarylacetoacetate hydrolase–deficient mouse (Fah–/–, Rag2–/–, Il2rg–/–, termed the FRG mouse) engrafted with human hepatocytes (FRG huHep). FRG huHep mice supported vigorous, quantifiable P. falciparum LS development that culminated in complete maturation of LS at approximately 7 days after infection, providing a relevant model for LS development in humans. The infections allowed observations of previously unknown expression of proteins in LS, including P. falciparum translocon of exported proteins 150 (PTEX150) and exported protein-2 (EXP-2), components of a known parasite protein export machinery. LS schizonts exhibited exoerythrocytic merozoite formation and merosome release. Furthermore, FRG mice backcrossed to the NOD background and repopulated with huHeps and human red blood cells supported reproducible transition from LS infection to blood-stage infection. Thus, these mice constitute reliable models to study human LS directly in vivo and demonstrate utility for studies of LS–to–blood-stage transition of a human malaria parasite. PMID:22996664

  9. Development of a Representative Mouse Model with Nonalcoholic Steatohepatitis.

    Science.gov (United States)

    Verbeek, Jef; Jacobs, Ans; Spincemaille, Pieter; Cassiman, David

    2016-06-01

    Non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease in the Western world. It represents a disease spectrum ranging from isolated steatosis to non-alcoholic steatohepatitis (NASH). In particular, NASH can evolve to fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. The development of novel treatment strategies is hampered by the lack of representative NASH mouse models. Here, we describe a NASH mouse model, which is based on feeding non-genetically manipulated C57BL6/J mice a 'Western style' high-fat/high-sucrose diet (HF-HSD). HF-HSD leads to early obesity, insulin resistance, and hypercholesterolemia. After 12 weeks of HF-HSD, all mice exhibit the complete spectrum of features of NASH, including steatosis, hepatocyte ballooning, and lobular inflammation, together with fibrosis in the majority of mice. Hence, this model closely mimics the human disease. Implementation of this mouse model will lead to a standardized setup for the evaluation of (i) underlying mechanisms that contribute to the progression of NAFLD to NASH, and (ii) therapeutic interventions for NASH. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  10. A novel animal model for in vivo study of liver cancer metastasis

    Institute of Scientific and Technical Information of China (English)

    Shinsuke Fujiwara; Katsutoshi Yoshizato; Hikaru Fujioka; Chise Tateno; Ken Taniguchi; Masahiro Ito; Hiroshi Ohishi; Rie Utoh; Hiromi Ishibashi; Takashi Kanematsu

    2012-01-01

    AIM:To establish an animal model with human hepatocyte-repopulated liver for the study of liver cancer metastasis.METHODS:Cell transplantation into mouse livers was conducted using alpha-fetoprotein (AFP)-producing human gastric cancer cells (h-GCCs) and h-hepatocytes as donor cells in a transgenic mouse line expressing urokinase-type plasminogen activator (uPA) driven by the albumin enhancer/promoter crossed with a severe combined immunodeficient (SCID) mouse line (uPA/SCID mice).Host mice were divided into two groups (A and B).Group A mice were transplanted with h-GCCs alone,and group B mice were transplanted with h-GCCs and h-hepatocytes together.The replacement index (RI),which is the ratio of transplanted h-GCCs and h-hepatocytes that occupy the examined area of a histological section,was estimated by measuring h-AFP and h-albumin concentrations in sera,respectively,as well as by immunohistochemical analyses of h-AFP and human cytokeratin 18 in histological sections.RESULTS:The h-GCCs successfully engrafted,repopulated,and colonized the livers of mice in group A (RI =22.0% ± 2.6%).These mice had moderately differentiated adenocarcinomatous lesions with disrupted glandular structures,which is a characteristics feature of gastric cancers.The serum h-AFP level reached 211.0 ± 142.2 g/mL (range,7.1-324.2 g/mL).In group B mice,the h-GCCs and h-hepatocytes independently engrafted,repopulated the host liver,and developed colonies (RI =12.0% ± 6.8% and 66.0% ± 12.3%,respectively).h-GCC colonies also showed typical adenocarcinomatous glandular structures around the h-hepatocyte-colonies.These mice survived for the full 56day-study and did not exhibit any metastasis of h-GCCs in the extrahepatic regions during the observational period.The mice with an h-hepatocyte-repopulated liver possessed metastasized h-GCCs and therefore could be a useful humanized liver animal model for studying liver cancer metastasis in vivo.CONCLUSION:A novel animal model of

  11. Hepatocyte-specific deletion of Cdc42 results in delayed liver regeneration after partial hepatectomy in mice

    DEFF Research Database (Denmark)

    Yuan, Haixin; Zhang, Hong; Wu, Xunwei

    2009-01-01

    Cdc42, a member of the Rho guanosine triphosphatase (GTPase) family, plays important roles in the regulation of the cytoskeleton, cell proliferation, cell polarity, and cellular transport, but little is known about its specific function in mammalian liver. We investigated the function of Cdc42...... in regulating liver regeneration. Using a mouse model with liver-specific knockout of Cdc42 (Cdc42LK), we studied liver regeneration after partial hepatectomy. Histological analysis, immunostaining, and western blot analysis were performed to characterize Cdc42LK livers and to explore the role of Cdc42 in liver...... regeneration. In control mouse livers, Cdc42 became activated between 3 and 24 hours after partial hepatectomy. Loss of Cdc42 led to a significant delay of liver recovery after partial hepatectomy, which was associated with reduced and delayed DNA synthesis indicated by 5-bromo-2'-deoxyuridine staining...

  12. In vitro metabolism of 2,2',3,4',5,5',6-heptachlorobiphenyl(CB187) with liver microsomes of rats, hamsters and guinea pigs

    Energy Technology Data Exchange (ETDEWEB)

    Koga, N.; Ohta, C.; Kanamaru, T. [Nakamura Gakuen Univ., Fukuoka (Japan); Haraguchi, K. [Daiichi Coll. of Pharmaceutical Sciences, Fukuoka (Japan); Kato, Y.; Yamada, S. [Univ. of Shizuoka, Shizuoka (Japan)

    2004-09-15

    PCB congeners possess extremely high lipophilicity and biological stability, and as a result they are not easily eliminated from the body once ingested. In particular, not only 2,4,5-trichlorosubstituted but also 6 or more chlorine-substituted PCBs such as 2,2',3',4,4',5-hexa-chlorobiphenyl (hexaCB) (CB138), 2,2',4,4',5,5'-hexaCB (CB153), 2,2',3,4,4',5,5'-heptachloro-biphenyl (heptaCB) (CB180) and 2,2',3,4',5,5',6-heptaCB (CB187) have been detected in blood and adipose tissues of mammals and human mother's milk at higher concentration. In addition, the 4-hydroxy (OH)-metabolite of CB187 has been reported to be present in human blood at the highest concentration of that derived from other PCB congeners. Although CB187, a tri-ortho-PCB, is one of the minor component in the commercial PCB preparations such as Clophen, Aroclor and Kanechlor, the toxic equivalency factor (TEF) which is used for dioxin-like PCB congeners including coplanar-PCBs and mono-ortho-PCBs to assess the potency of the toxicity has not been set up for di- and tri-ortho-PCB congeners. These facts indicate that 4-OH-PCB187 become more persistent and more important toxicologically than the parent CB187. However, there is little report about biotransformation in vivo or in vitro of CB187 in animals. Therefore, we examined CB187 metabolism by liver microsomes of rats, hamsters and guinea pigs.

  13. Maraviroc, a CCR5 antagonist, ameliorates the development of hepatic steatosis in a mouse model of non-alcoholic fatty liver disease (NAFLD).

    Science.gov (United States)

    Pérez-Martínez, Laura; Pérez-Matute, Patricia; Aguilera-Lizarraga, Javier; Rubio-Mediavilla, Susana; Narro, Judit; Recio, Emma; Ochoa-Callejero, Laura; Oteo, José-Antonio; Blanco, José-Ramón

    2014-07-01

    Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the general population. The NAFLD spectrum ranges from simple steatosis to cirrhosis. The chemokine CCL5/RANTES plays an important role in the progression of hepatic inflammation and fibrosis. The objective of this study was to examine the effects of maraviroc, a CCR5 antagonist, on liver pathology in a NAFLD mouse model. A total of 32 male C57BL/6 mice were randomly assigned to one of four groups: (i) control group (chow diet plus tap water); (ii) maraviroc group (chow diet plus maraviroc in drinking water); (iii) high-fat diet (HFD) group (HFD plus tap water); and (iv) maraviroc/HFD group (HFD plus maraviroc). All mice were sacrificed 16 weeks after the beginning of the experiment. Biochemical analyses and liver examinations were performed. Mice in the HFD group showed a tendency towards increased body mass gain and liver damage compared with the maraviroc/HFD group. Moreover, liver weight in the HFD group was significantly higher than in the maraviroc/HFD group. Hepatic triglyceride concentration in the maraviroc/HFD group was significantly lower than in the HFD group. Interestingly, the maraviroc/HFD group exhibited a lower degree of steatosis. Furthermore, hepatic CCL5/RANTES expression was significantly lower in the maraviroc/HFD group than in the HFD group. Overall, no differences were observed between the control group and the maraviroc group. Maraviroc ameliorates hepatic steatosis in an experimental model of NAFLD. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Cross-activating invariant NKT cells and kupffer cells suppress cholestatic liver injury in a mouse model of biliary obstruction.

    Directory of Open Access Journals (Sweden)

    Caroline C Duwaerts

    Full Text Available Both Kupffer cells and invariant natural killer T (iNKT cells suppress neutrophil-dependent liver injury in a mouse model of biliary obstruction. We hypothesize that these roles are interdependent and require iNKT cell-Kupffer cell cross-activation. Female, wild-type and iNKT cell-deficient C57Bl/6 mice were injected with magnetic beads 3 days prior to bile duct ligation (BDL in order to facilitate subsequent Kupffer cell isolation. On day three post-BDL, the animals were euthanized and the livers dissected. Necrosis was scored; Kupffer cells were isolated and cell surface marker expression (flow cytometry, mRNA expression (qtPCR, nitric oxide (NO (. production (Griess reaction, and protein secretion (cytometric bead-array or ELISAs were determined. To address the potential role of NO (. in suppressing neutrophil accumulation, a group of WT mice received 1400W, a specific inducible nitric oxide synthase (iNOS inhibitor, prior to BDL. To clarify the mechanisms underlying Kupffer cell-iNKT cell cross-activation, WT animals were administered anti-IFN-γ or anti-lymphocyte function-associated antigen (LFA-1 antibody prior to BDL. Compared to their WT counterparts, Kupffer cells obtained from BDL iNKT cell-deficient mice expressed lower iNOS mRNA levels, produced less NO (. , and secreted more neutrophil chemoattractants. Both iNOS inhibition and IFN-γ neutralization increased neutrophil accumulation in the livers of BDL WT mice. Anti-LFA-1 pre-treatment reduced iNKT cell accumulation in these same animals. These data indicate that the LFA-1-dependent cross-activation of iNKT cells and Kupffer cells inhibits neutrophil accumulation and cholestatic liver injury.

  15. MALDI Mass Spectral Imaging of Bile Acids Observed as Deprotonated Molecules and Proton-Bound Dimers from Mouse Liver Sections

    Science.gov (United States)

    Rzagalinski, Ignacy; Hainz, Nadine; Meier, Carola; Tschernig, Thomas; Volmer, Dietrich A.

    2018-02-01

    Bile acids (BAs) play two vital roles in living organisms, as they are involved in (1) the secretion of cholesterol from liver, and (2) the lipid digestion/absorption in the intestine. Abnormal bile acid synthesis or secretion can lead to severe liver disorders. Even though there is extensive literature on the mass spectrometric determination of BAs in biofluids and tissue homogenates, there are no reports on the spatial distribution in the biliary network of the liver. Here, we demonstrate the application of high mass resolution/mass accuracy matrix-assisted laser desorption/ionization (MALDI)-Fourier-transform ion cyclotron resonance (FTICR) to MS imaging (MSI) of BAs at high spatial resolutions (pixel size, 25 μm). The results show chemical heterogeneity of the mouse liver sections with a number of branching biliary and blood ducts. In addition to ion signals from deprotonation of the BA molecules, MALDI-MSI generated several further intense signals at larger m/z for the BAs. These signals were spatially co-localized with the deprotonated molecules and easily misinterpreted as additional products of BA biotransformations. In-depth analysis of accurate mass shifts and additional electrospray ionization and MALDI-FTICR experiments, however, confirmed them as proton-bound dimers. Interestingly, dimers of bile acids, but also unusual mixed dimers of different taurine-conjugated bile acids and free taurine, were identified. Since formation of these complexes will negatively influence signal intensities of the desired [M - H]- ions and significantly complicate mass spectral interpretations, two simple broadband techniques were proposed for non-selective dissociation of dimers that lead to increased signals for the deprotonated BAs. [Figure not available: see fulltext.

  16. A small population of liver endothelial cells undergoes endothelial-to-mesenchymal transition in response to chronic liver injury.

    Science.gov (United States)

    Ribera, Jordi; Pauta, Montse; Melgar-Lesmes, Pedro; Córdoba, Bernat; Bosch, Anna; Calvo, Maria; Rodrigo-Torres, Daniel; Sancho-Bru, Pau; Mira, Aurea; Jiménez, Wladimiro; Morales-Ruiz, Manuel

    2017-11-01

    Rising evidence points to endothelial-to-mesenchymal transition (EndMT) as a significant source of the mesenchymal cell population in fibrotic diseases. In this context, we hypothesized that liver endothelial cells undergo EndMT during fibrosis progression. Cirrhosis in mice was induced by CCl 4 A transgenic mouse expressing a red fluorescent protein reporter under the control of Tie2 promoter (Tie2-tdTomato) was used to trace the acquisition of EndMT. Sinusoidal vascular connectivity was evaluated by intravital microscopy and high-resolution three-dimensional confocal microscopy. A modest but significant fraction of liver endothelial cells from both cirrhotic patients and CCl 4 -treated Tie2-tdTomato mice acquired an EndMT phenotype characterized by the coexpression of CD31 and α-smooth muscle actin, compared with noncirrhotic livers. Bone morphogenetic protein-7 (BMP-7) inhibited the acquisition of EndMT induced by transforming growth factor-β1 (TGF-β1) treatment in cultured primary mouse liver endothelial cells from control mice. EndMT was also reduced significantly in vivo in cirrhotic Tie2-tdTomato mice treated intraperitoneally with BMP-7 compared with untreated mice (1.9 ± 0.2 vs. 3.8 ± 0.3%, respectively; P livers correlated with a significant decrease in liver fibrosis ( P livers in both animal models and patients. BMP-7 treatment decreases the occurrence of the EndMT phenotype and has a positive impact on the severity of disease by reducing fibrosis and sinusoidal vascular disorganization. NEW & NOTEWORTHY A subpopulation of liver endothelial cells from cirrhotic patients and mice with liver fibrosis undergoes endothelial-to-mesenchymal transition. Liver endothelial cells from healthy mice could transition into a mesenchymal phenotype in culture in response to TGF-β1 treatment. Fibrotic livers treated chronically with BMP-7 showed lower EndMT acquisition, reduced fibrosis, and improved vascular organization. Copyright © 2017 the American

  17. Liver cancer induction by 241Am and thorotrast in deer mice and grasshopper mice

    International Nuclear Information System (INIS)

    Taylor, G.N.; Mays, C.W.; Lloyd, R.D.; Jones, C.W.; Rojas, J.; Wrenn, M.E.; Ayoroa, G.; Kaul, A.; Riedel, W.

    1986-01-01

    The carcinogenicity of 241 Am, relative to thorotrast, has been determined in two species of mice: the grasshopper mouse (Onychomys leucogaster) and the deer mouse (Peromyscus maniculatus). These species were used since both have high uptakes of Pu and Am and, unlike conventional mice and rats, both retain relatively high concentrations of plutonium and americium in their livers. The study indicated that the liver carcinogenicity of comparable rad doses of 241 Am or thorotrast is approximately equal. The toxicity ratio ( 241 Am/thorotrast) for liver cancer induction approximated 1.2 with a range of about 0.6 to 1.6. This suggested that nonradiation factors of thorotrast were not significant in liver tumor induction. (orig.)

  18. Rex3 (reduced in expression 3) as a new tumor marker in mouse hepatocarcinogenesis

    International Nuclear Information System (INIS)

    Braeuning, Albert; Jaworski, Maike; Schwarz, Michael; Koehle, Christoph

    2006-01-01

    In a previous microarray expression analysis, Rex3, a gene formerly not linked to tumor formation, was found to be highly overexpressed in both Ctnnb1-(β-Catenin) and Ha-ras-mutated mouse liver tumors. Subsequent analyses by in situ hybridization and real-time PCR confirmed a general liver tumor-specific overexpression of the gene (up to 400-fold). To investigate the role of Rex3 in liver tumors, hepatoma cells were transfected with FLAG- and Myc-tagged Rex3 expression vectors. Rex3 was shown to be exclusively localized to the cytoplasm, as determined by fluorescence microscopy and Western blotting. However, forced overexpression of Rex3 did not significantly affect proliferation or stress-induced apoptosis of transfected mouse hepatoma cells. Rex3 mRNA was determined in primary hepatocytes in culture by real-time PCR. In primary mouse hepatocytes, expression of Rex3 increased while cells dedifferentiated in culture. This effect was abolished when hepatocytes were maintained in a differentiated state. Furthermore, expression of Rex3 decreased in mouse liver with age of mice and the expression profile was highly correlated to that of the tumor markers α-fetoprotein and H19. The findings suggest a role of Rex3 as a marker for hepatocyte differentiation/dedifferentiation processes and tumor formation

  19. Altered cytochrome P450 activities and expression levels in the liver and intestines of the monosodium glutamate-induced mouse model of human obesity.

    Science.gov (United States)

    Tomankova, Veronika; Liskova, Barbora; Skalova, Lenka; Bartikova, Hana; Bousova, Iva; Jourova, Lenka; Anzenbacher, Pavel; Ulrichova, Jitka; Anzenbacherova, Eva

    2015-07-15

    Cytochromes P450 (CYPs) are enzymes present from bacteria to man involved in metabolism of endogenous and exogenous compounds incl. drugs. Our objective was to assess whether obesity leads to changes in activities and expression of CYPs in the mouse liver, small intestine and colon. An obese mouse model with repeated injection of monosodium glutamate (MSG) to newborns was used. Controls were treated with saline. All mice were sacrificed at 8 months. In the liver and intestines, levels of CYP mRNA and proteins were analyzed using RT-PCR and Western blotting. Activities of CYP enzymes were measured with specific substrates of human orthologous forms. At the end of the experiment, body weight, plasma insulin and leptin levels as well as the specific content of hepatic CYP enzymes were increased in obese mice. Among CYP enzymes, hepatic CYP2A5 activity, protein and mRNA expression increased most significantly in obese animals. Higher activities and protein levels of hepatic CYP2E1 and 3A in the obese mice were also found. No or a weak effect on CYPs 2C and 2D was observed. In the small intestine and colon, no changes of CYP enzymes were detected except for increased expression of CYP2E1 and decreased expression of CYP3A mRNAs in the colon of the obese mice. Results of our study suggest that the specific content and activities of some liver CYP enzymes (especially CYP2A5) can be increased in obese mice. Higher activity of CYP2A5 (CYP2A6 human ortholog) could lead to altered metabolism of drug substrates of this enzyme (valproic acid, nicotine, methoxyflurane). Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Continuous recording of long-chain acyl-coenzyme A synthetase activity using fluorescently labeled bovine serum albumin

    DEFF Research Database (Denmark)

    Demant, Erland J.F.; Nystrøm, Birthe T.

    2001-01-01

    acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes......acyl-Coenzyme A, synthetase, activity assay, fluorescence recording, fatty acid probe, serum albumin, hydroxycoumarin, detergent, micelles, Pseudomonas fragi, rat liver microsomes...

  1. Genotoxic, epigenetic, and transcriptomic effects of tamoxifen in mouse liver

    International Nuclear Information System (INIS)

    Conti, Aline de; Tryndyak, Volodymyr; Churchwell, Mona I.; Melnyk, Stepan; Latendresse, John R.; Muskhelishvili, Levan; Beland, Frederick A.; Pogribny, Igor P.

    2014-01-01

    Highlights: • Treatment of female mice with tamoxifen caused genotoxic changes in the livers. • Tamoxifen treatment did not affect the hepatic epigenome. • Tamoxifen caused over-expression of hepatic Lcn13 and Pparγ genes. • Mice are resistant to tamoxifen-induced liver carcinogenesis and fatty liver injury. - Abstract: Tamoxifen is a non-steroidal anti-estrogenic drug widely used for the treatment and prevention of breast cancer in women; however, there is evidence that tamoxifen is hepatocarcinogenic in rats, but not in mice. Additionally, it has been reported that tamoxifen may cause non-alcoholic fatty liver disease (NAFLD) in humans and experimental animals. The goals of the present study were to (i) investigate the mechanisms of the resistance of mice to tamoxifen-induced hepatocarcinogenesis, and (ii) clarify effects of tamoxifen on NAFLD-associated liver injury. Feeding female WSB/EiJ mice a 420 p.p.m. tamoxifen-containing diet for 12 weeks resulted in an accumulation of tamoxifen-DNA adducts, (E)-α-(deoxyguanosin-N 2 -yl)-tamoxifen (dG-TAM) and (E)-α-(deoxyguanosin-N 2 -yl)-N-desmethyltamoxifen (dG-DesMeTAM), in the livers. The levels of hepatic dG-TAM and dG-DesMeTAM DNA adducts in tamoxifen-treated mice were 578 and 340 adducts/108 nucleotides, respectively, while the extent of global DNA and repetitive elements methylation and histone modifications did not differ from the values in control mice. Additionally, there was no biochemical or histopathological evidence of NAFLD-associated liver injury in mice treated with tamoxifen. A transcriptomic analysis of differentially expressed genes demonstrated that tamoxifen caused predominantly down-regulation of hepatic lipid metabolism genes accompanied by a distinct over-expression of the lipocalin 13 (Lcn13) and peroxisome proliferator receptor gamma (Pparγ), which may prevent the development of NAFLD. The results of the present study demonstrate that the resistance of mice to tamoxifen

  2. Elevation of liver endoplasmic reticulum stress in a modified choline-deficient l-amino acid-defined diet-fed non-alcoholic steatohepatitis mouse model.

    Science.gov (United States)

    Muraki, Yo; Makita, Yukimasa; Yamasaki, Midori; Amano, Yuichiro; Matsuo, Takanori

    2017-05-06

    Endoplasmic reticulum (ER) stress caused by accumulation of misfolded proteins is observed in several kinds of diseases. Since ER stress is reported to be involved in the progression of non-alcoholic steatohepatitis (NASH), highly sensitive and simple measurement methods are required for research into developing novel therapy for NASH. To investigate the involvement of ER stress in NASH pathogenesis in a mouse model, an assay for liver ER stress was developed using ER stress activated indicator-luciferase (ERAI-Luc) mice. To establish the assay method for detection of ER stress in the liver, tunicamycin (TM) (0.3 mg/kg i. p.) was administered to ERAI-Luc mice, and the luciferase activity was measured in ex vivo and in vivo. To evaluate ER stress in the NASH model, ERAI-Luc mice were fed a modified choline-deficient l-amino acid-defined (mCDAA) diet for 14 weeks. After measurement of ER stress by luminescence imaging, levels of liver lipids and pro-fibrotic and pro-inflammatory gene expression were measured as NASH-related indexes. In non-invasive whole-body imaging, TM elevated luciferase activity in the liver, induced by activation of ER stress. The highest luminescence in the liver was confirmed by ex vivo imaging of isolated tissues. In parallel with progression of NASH, elevated luminescence induced by ER stress in liver was observed in mCDAA diet-fed ERAI-Luc mice. Luciferase activity was significantly and positively correlated to levels of triglyceride and free cholesterol in the liver, as well as to the mRNA expression of type 1 collagen α1 chain and tumor necrosis factor α. These data indicated that the use of ERAI-Luc mice was effective in the detection of ER stress in the liver. Moreover, the NASH model using ERAI-Luc mice can be a useful tool to clarify the role of ER stress in pathogenesis of NASH and to evaluate effects of drugs targeted against ER stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Metabolism and binding of cyclophosphamide and its metabolite acrolein to rat hepatic microsomal cytochrome P-450

    International Nuclear Information System (INIS)

    Marinello, A.J.; Bansal, S.K.; Paul, B.; Koser, P.L.; Love, J.; Struck, R.F.; Gurtoo, H.L.

    1984-01-01

    The hepatic cytochrome P-450-mediated metabolism and metabolic activation of [chloroethyl-3H]cyclophosphamide [( chloroethyl-3H]CP) and [4-14C]cyclophosphamide [( 4-14C]CP) were investigated in vitro in the reconstituted system containing cytochrome P-450 isolated from phenobarbital-treated rats. In addition, hepatic microsomal binding and the hepatic microsome-mediated metabolism of [14C]acrolein, a metabolite of [4-14C]CP, were also investigated. The metabolism of [chloroethyl-3H]CP and [4-14C]CP to polar metabolites was found to depend on the presence of NADPH and showed concentration dependence with respect to cytochrome P-450 and NADPH:cytochrome P-450 reductase. Km and Vmax values were essentially similar. The patterns of inhibition by microsomal mixed-function oxidase inhibitors, anti-cytochrome P-450 antibody, and heat denaturation of the cytochrome P-450 were essentially similar, with subtle differences between [4-14C]CP and [chloroethyl-3H]CP metabolism. The in vitro metabolic activation of CP in the reconstituted system demonstrated predominant binding of [chloroethyl-3H]CP to nucleic acids and almost exclusive binding of [4-14C]CP to proteins. Gel electrophoresis-fluorography of the proteins in the reconstituted system treated with [4-14C]CP demonstrated localization of the 14C label in the cytochrome P-450 region. To examine this association further, hepatic microsomes were modified with [14C]acrolein in the presence and the absence of NADPH. The results confirmed covalent association between [14C]acrolein and cytochrome P-450 in the microsomes and also demonstrated further metabolism of [14C]acrolein, apparently to an epoxide, which is capable of binding covalently to proteins. The results of these investigations not only confirm the significance of primary metabolism but also emphasize the potential role of the secondary metabolism of cyclophosphamide in some of its toxic manifestations

  4. Inhibition of rat mammary microsomal oxidation of ethanol to acetaldehyde by plant polyphenols.

    Science.gov (United States)

    Maciel, María Eugenia; Castro, José Alberto; Castro, Gerardo Daniel

    2011-07-01

    We previously reported that the microsomal fraction from rat mammary tissue is able to oxidize ethanol to acetaldehyde, a mutagenic-carcinogenic metabolite, depending on the presence of NADPH and oxygen but not inhibited by carbon monoxide or other cytochrome P450 inhibitors. The process was strongly inhibited by diphenyleneiodonium, a known inhibitor of NADPH oxidase, and by nordihydroguaiaretic acid, an inhibitor of lipoxygenases. This led us to suggest that both enzymes could be involved. With the purpose of identifying natural compounds present in food with the ability to decrease the production of acetaldehyde in mammary tissue, in the present studies, several plant polyphenols having inhibitory effects on lipoxygenases and of antioxidant nature were tested as potential inhibitors of the rat mammary tissue microsomal pathway of ethanol oxidation. We included in the present screening study 32 polyphenols having ready availability and that were also tested against the rat mammary tissue cytosolic metabolism of ethanol to acetaldehyde. Several polyphenols were also able to inhibit the microsomal ethanol oxidation at concentrations as low was 10-50 μM. The results of these screening experiments suggest the potential of several plant polyphenols to prevent in vivo production and accumulation of acetaldehyde in mammary tissue.

  5. Uptake of [3H]colchicine into brain and liver of mouse, rat, and chick

    International Nuclear Information System (INIS)

    Bennett, E.L.; Alberti, M.H.; Flood, J.F.

    1981-01-01

    The uptake of [ring A-4- 3 H] colchicine and [ring C-methoxy- 3 H]colchicine has been compared in mice from 1 to 24 hr after administration. Less radioactivity was found in brain after administration of ring-labeled colchicine than after administration of the methoxy-labeled colchicine. Three hr after administration of ring-labeled colchicine, 5% of the label was in liver and about 0.01% of the label was present in brain. Forty percent of the brain radioactivity was bound to tubulin as determined by vinblastine precipitation. After 3 hr, an average of 8% of the radioactivity from methoxy-labeled colchicine was found in the liver and 0.16% in brain. However, less than 5% of the activity in brain was precipitated by vinblastine, and the colchicine equivalent was comparable to that found after administration of the ring-labeled colchicine. The amount of colchicine entering mouse brain after subcutaneous injection is comparable to the minimum behaviorally effective dose when administered to the caudate. The metabolism of [ring C-methoxy- 3 H] and [ring A- 3 H]colchicine was also studied in rats. The general pattern was similar to mice; less radioactivity was found in brain after administration of the ring-labeled alkaloid than after administration of methoxy-labeled colchicine. Again, 40-50% of ring-labeled colchicine was precipitated by vinblastine. A much smaller percentage of the methoxy-labeled drug was precipitated by vinblastine than of the ring A-labeled colchicine. These experiments, together with behavioral experiments, support the hypotheses that structural alterations in synapses by recently synthesized proteins which are transported down the axons and dendrites may be an essential process for long-term memory formation

  6. Pyrethroid activity-based probes for profiling cytochrome P450 activities associated with insecticide interactions.

    Science.gov (United States)

    Ismail, Hanafy M; O'Neill, Paul M; Hong, David W; Finn, Robert D; Henderson, Colin J; Wright, Aaron T; Cravatt, Benjamin F; Hemingway, Janet; Paine, Mark J I

    2013-12-03

    Pyrethroid insecticides are used to control diseases spread by arthropods. We have developed a suite of pyrethroid mimetic activity-based probes (PyABPs) to selectively label and identify P450s associated with pyrethroid metabolism. The probes were screened against pyrethroid-metabolizing and nonmetabolizing mosquito P450s, as well as rodent microsomes, to measure labeling specificity, plus cytochrome P450 oxidoreductase and b5 knockout mouse livers to validate P450 activation and establish the role for b5 in probe activation. Using PyABPs, we were able to profile active enzymes in rat liver microsomes and identify pyrethroid-metabolizing enzymes in the target tissue. These included P450s as well as related detoxification enzymes, notably UDP-glucuronosyltransferases, suggesting a network of associated pyrethroid-metabolizing enzymes, or "pyrethrome." Considering the central role P450s play in metabolizing insecticides, we anticipate that PyABPs will aid in the identification and profiling of P450s associated with insecticide pharmacology in a wide range of species, improving understanding of P450-insecticide interactions and aiding the development of unique tools for disease control.

  7. Hypophysectomy eliminates and growth hormone (GH) maintains the midpregnancy elevation in GH receptor and serum binding protein in the mouse

    International Nuclear Information System (INIS)

    Sanchez-Jimenez, F.; Fielder, P.J.; Martinez, R.R.; Smith, W.C.; Talamantes, F.

    1990-01-01

    [ 125 I]Iodomouse GH [( 125 I]iodo-mGH) binding to samples of serum and hepatic microsomal membranes was measured in hypophysectomized pregnant, sham-operated pregnant, intact pregnant, and intact adult virgin mice. Surgeries were carried out on day 11 of pregnancy, and the animals were killed on day 14. The binding of mGH to both serum and hepatic microsomal membranes of intact virgin mice was much lower than to those of intact pregnant mice. In hypophysectomized mice, the mGH-binding capacity of both serum and hepatic microsomes decreased to values similar to those of nonpregnant mice. No significant differences were observed between intact and sham-operated pregnant animals in the maternal serum mGH concentration, the serum GH-binding protein concentration, or the hepatic GH receptor concentration. GH receptor and binding protein-encoding mRNAs were also higher in intact and sham-operated pregnant mice than in virgin and hypophysectomized mice. Hypophysectomized mice were treated with 200 micrograms/day bovine GH, administered by osmotic minipump; after 3 days of treatment, a significant elevation of hepatic GH receptor and serum GH-binding protein levels was observed. These results demonstrate an up-regulation of hepatic GH receptors and serum GH-binding protein by GH during pregnancy in the mouse

  8. [Glucose-6-phosphatase from nuclear envelope in rat liver].

    Science.gov (United States)

    González-Mujica, Freddy

    2008-06-01

    Nuclear envelope (NE) and microsomal glucosa-6-phosphatase (G-6-Pase) activities were compared. Intact microsomes were unable to hydrolyze mannose-6-phosphate (M-6-P), on the other hand, intact NE hydrolyzes this substrate. Galactose-6-phosphate showed to be a good substrate for both NE and microsomal enzymes, with similar latency to that obtained with M-6-P using microsomes. In consequence, this substrate was used to measure the NE integrity. The kinetic parameters (Kii and Kis) of the intact NE G-6-Pase for the phlorizin inhibition using glucose-6-phosphate (G-6-P) and M-6-P as substrates, were very similar. The NE T1 transporter was more sensitive to amiloride than the microsomal T1. The microsomal system was more sensitive to N-ethylmalemide (NEM) than the NE and the latter was insensitive to anion transport inhibitors DIDS and SITS, which strongly affect the microsomal enzyme. The above results allowed to postulate the presence of a hexose-6-phosphate transporter in the NE which is able to carry G-6-P and M-6-P, and perhaps other hexose-6-phosphate which could be different from that present in microsomes or, if it is the same, its activity could by modified by the membrane system where it is included. The higher PPi hydrolysis activity of the intact NE G-6-Pase in comparison to the intact microsomal, suggests differences between the Pi/PPi transport (T2) of both systems. The lower sensitivity of the NE G-6-Pase to NEM suggests that the catalytic subunit of this system has some differences with the microsomal isoform.

  9. Altered carbohydrate, lipid, and xenobiotic metabolism by liver from rats flown on Cosmos 1887

    Science.gov (United States)

    Merrill, A. H. Jr; Hoel, M.; Wang, E.; Mullins, R. E.; Hargrove, J. L.; Jones, D. P.; Popova, I. A.; Merrill AH, J. r. (Principal Investigator)

    1990-01-01

    To determine the possible biochemical effects of prolonged weightlessness on liver function, samples of liver from rats that had flown aboard Cosmos 1887 were analyzed for protein, glycogen, and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the glycogen content and hydroxymethylglutaryl-CoA (HMG-CoA) reductase activities for the rats flown on Cosmos 1887 and decreases in the amount of microsomal cytochrome P-450 and the activities of aniline hydroxylase and ethylmorphine N-demethylase, cytochrome P-450-dependent enzymes. These results support the earlier finding of differences in these parameters and suggest that altered hepatic function could be important during spaceflight and/or the postflight recovery period.

  10. In vitro differentiation of mouse embryonic stem cells into functional ...

    African Journals Online (AJOL)

    Studies have shown that embryonic stem (ES) cells can be successfully differentiated into liver cells, which offer the potential unlimited cell source for a variety of end-stage liver disease. In our study, in order to induce mouse ES cells to differentiate into hepatocyte-like cells under chemically defined conditions, ES cells ...

  11. In vitro metabolism and stability of the actinide chelating agent 3,4,3-LI(1,2-HOPO).

    Science.gov (United States)

    Choi, Taylor A; Furimsky, Anna M; Swezey, Robert; Bunin, Deborah I; Byrge, Patricia; Iyer, Lalitha V; Chang, Polly Y; Abergel, Rebecca J

    2015-05-01

    The hydroxypyridinonate ligand 3,4,3-LI(1,2-HOPO) is currently under development for radionuclide chelation therapy. The preclinical characterization of this highly promising ligand comprised the evaluation of its in vitro properties, including microsomal, plasma, and gastrointestinal fluid stability, cytochrome P450 inhibition, plasma protein binding, and intestinal absorption using the Caco-2 cell line. When mixed with active human liver microsomes, no loss of parent compound was observed after 60 min, indicating compound stability in the presence of liver microsomal P450. At the tested concentrations, 3,4,3-LI(1,2-HOPO) did not significantly influence the activities of any of the cytochromal isoforms screened. Thus, 3,4,3-LI(1,2-HOPO) is unlikely to cause drug-drug interactions by inhibiting the metabolic clearance of coadministered drugs metabolized by these enzymes. Plasma protein-binding assays revealed that the compound is protein-bound in dogs and less extensively in rats and humans. In the plasma stability study, the compound was stable after 1 h at 37°C in mouse, rat, dog, and human plasma samples. Finally, a bidirectional permeability assay demonstrated that 3,4,3-LI(1,2-HOPO) is not permeable across the Caco-2 monolayer, highlighting the need to further evaluate the effects of various compounds with known permeability enhancement properties on the permeability of the ligand in future studies. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  12. Establishment of a novel radioligand assay using eukaryotically expressed cytochrome P4502D6 for the measurement of liver kidney microsomal type 1 antibody in patients with autoimmune hepatitis and hepatitis C virus infection.

    Science.gov (United States)

    Ma, Y; Gregorio, G; Gäken, J; Muratori, L; Bianchi, F B; Mieli-Vergani, G; Vergani, D

    1997-06-01

    Liver kidney microsomal type 1 antibody (LKM1) is the diagnostic marker of autoimmune hepatitis (AIH) type 2 and is also found in patients with hepatitis C virus (HCV) infection. Cytochrome P4502D6 (CYP2D6) is the documented target antigen of LKM1 in AIH, but not in HCV infection. To compare the reactivity in the two conditions, we established a radioligand assay using eukaryotically expressed CYP2D6 as target. A 1.2-kb human CYP2D6 cDNA was isolated from a human liver cDNA library and subcloned into an in vitro transcription vector pSP64 Poly(A). Recombinant CYP2D6 was then produced by in vitro transcription/translation, metabolically labelled with 35S methionine and used in the immunoprecipitation assay. Antibodies that bound radiolabelled CYP2D6 were immunoprecipitated and their levels assessed as cpm. Sera from 50 LKM1-positive patients (26 with AIH; 24 with HCV infection), 128 LKM1-negative patients and 57 normal controls were tested. Reactivity to 35S labelled CYP2D6 was observed in all LKM1-positive sera from patients with AIH and HCV infection, but in none of the controls. The cpm in both conditions were significantly higher than in normal controls (pLKM1 (r 0.87, p<0.001 and r=0.64, p<0.001 for AIH and HCV infection, respectively). Reactivity to 35S labelled CYP2D6 was inhibited by addition of an excess of eukaryotically expressed CYP2D6. CYP2D6 is a major target antigen of both AIH and HCV infection. The novel radioligand assay is highly sensitive and specific.

  13. Investigation of the roles of exosomes in colorectal cancer liver metastasis.

    Science.gov (United States)

    Wang, Xia; Ding, Xiaoling; Nan, Lijuan; Wang, Yiting; Wang, Jing; Yan, Zhiqiang; Zhang, Wei; Sun, Jihong; Zhu, Wei; Ni, Bing; Dong, Suzhen; Yu, Lei

    2015-05-01

    The leading cause of death among cancer patients is tumor metastasis. Tumor-derived exosomes are emerging as mediators of metastasis. In the present study, we demonstrated that exosomes play a pivotal role in the metastatic progression of colorectal cancer. First, a nude mouse model of colorectal cancer liver metastasis was established and characterized. Then, we demonstrated that exosomes from a highly liver metastatic colorectal cancer cell line (HT-29) could significantly increase the metastatic tumor burden and distribution in the mouse liver of Caco-2 colorectal cancer cells, which ordinarily exhibit poor liver metastatic potential. We further investigated the mechanisms by which HT-29-derived-exosomes influence the liver metastasis of colorectal cancer and found that mice treated with HT-29-derived exosomes had a relatively higher level of CXCR4 in the metastatic microenvironment, indicating that exosomes may promote colorectal cancer metastasis by recruiting CXCR4-expressing stromal cells to develop a permissive metastatic microenvironment. Finally, the migration of Caco-2 cells was significantly increased following treatment with HT-29-derived exosomes in vitro, further supporting a role for exosomes in modulating colorectal tumor-derived liver metastasis. The data from the present study may facilitate further translational medicine research into the prevention and treatment of colorectal cancer liver metastasis.

  14. Sex-related differences in NADPH-dependent lipid peroxidation induced by cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Masao; Nagai, Yasushi

    1986-10-01

    Male and female rats were dosed once a day for 2 days with injections of 1.5 mg Cd/kg. Formation of thiobarbituric acid reactive substances (TBA-RS) was significantly increased in male rat liver but not in the females. NADPH-dependent lipid peroxidation in vitro in microsomes derived from untreated rat liver was greater in males than in females. Furthermore, addition of cadmium (Cd) to microsomes isolated from male rat liver produced a dose-dependent potentiation of NADPH-dependent lipid peroxidation from low concentrations of CD. In microsomes derived from females a significant increase in lipid peroxidation was observed only at high Cd concentrations. NADPH-dependent lipid peroxidation enhanced by Cd was greater in the males than in the females. These data suggest that a sex-related difference in the ability of Cd to induce lipid peroxidation in vivo in rat liver appears to be mediated partly through differences in hepatic microsomal NADPH-dependent lipid peroxidation.

  15. Lineage fate of ductular reactions in liver injury and carcinogenesis.

    Science.gov (United States)

    Jörs, Simone; Jeliazkova, Petia; Ringelhan, Marc; Thalhammer, Julian; Dürl, Stephanie; Ferrer, Jorge; Sander, Maike; Heikenwalder, Mathias; Schmid, Roland M; Siveke, Jens T; Geisler, Fabian

    2015-06-01

    Ductular reactions (DRs) are observed in virtually all forms of human liver disease; however, the histogenesis and function of DRs in liver injury are not entirely understood. It is widely believed that DRs contain bipotential liver progenitor cells (LPCs) that serve as an emergency cell pool to regenerate both cholangiocytes and hepatocytes and may eventually give rise to hepatocellular carcinoma (HCC). Here, we used a murine model that allows highly efficient and specific lineage labeling of the biliary compartment to analyze the histogenesis of DRs and their potential contribution to liver regeneration and carcinogenesis. In multiple experimental and genetic liver injury models, biliary cells were the predominant precursors of DRs but lacked substantial capacity to produce new hepatocytes, even when liver injuries were prolonged up to 12 months. Genetic modulation of NOTCH and/or WNT/β-catenin signaling within lineage-tagged DRs impaired DR expansion but failed to redirect DRs from biliary differentiation toward the hepatocyte lineage. Further, lineage-labeled DRs did not produce tumors in genetic and chemical HCC mouse models. In summary, we found no evidence in our system to support mouse biliary-derived DRs as an LPC pool to replenish hepatocytes in a quantitatively relevant way in injury or evidence that DRs give rise to HCCs.

  16. Imaging of Herpes Simplex Virus Type 1 Thymidine Kinase Gene Expression with Radiolabeled 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in Liver by Hydrodynamic-based Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Song, In Ho; Lee, Tae Sup; Kang, Joo Hyun; Lee, Yong Jin; Kim, Kwang Il; An, Gwang Il; Chung, Wee Sup; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2009-10-15

    Hydrodynamic-based procedure is a simple and effective gene delivery method to lead a high gene expression in liver tissue. Non-invasive imaging reporter gene system has been used widely with herpes simplex virus type 1 thymidine kinase (HSV1-tk) and its various substrates. In the present study, we investigated to image the expression of HSV1-tk gene with 5-(2-iodovinyl)-2'-deoxyuridine (IVDU) in mouse liver by the hydrodynamicbased procedure. HSV1-tk or enhanced green fluorescence protein (EGFP) encoded plasmid DNA was transferred into the mouse liver by hydrodynamic injection. At 24 h post-injection, RT-PCR, biodistribution, fluorescence imaging, nuclear imaging and digital wholebody autoradiography (DWBA) were performed to confirm transferred gene expression. In RT-PCR assay using mRNA from the mouse liver, specific bands of HSV1-tk and EGFP gene were observed in HSV1-tk and EGFP expressing plasmid injected mouse, respectively. Higher uptake of radiolabeled IVDU was exhibited in liver of HSV1-tk gene transferred mouse by biodistribution study. In fluorescence imaging, the liver showed specific fluorescence signal in EGFP gene transferred mouse. Gamma-camera image and DWBA results showed that radiolabeled IVDU was accumulated in the liver of HSV1-tk gene transferred mouse. In this study, hydrodynamic-based procedure was effective in liver-specific gene delivery and it could be quantified with molecular imaging methods. Therefore, co-expression of HSV1-tk reporter gene and target gene by hydrodynamic-based procedure is expected to be a useful method for the evaluation of the target gene expression level with radiolabeled IVDU.

  17. Chemotactic and inflammatory responses in the liver and brain are associated with pathogenesis of Rift Valley fever virus infection in the mouse.

    Directory of Open Access Journals (Sweden)

    Kimberly K Gray

    Full Text Available Rift Valley fever virus (RVFV is a major human and animal pathogen associated with severe disease including hemorrhagic fever or encephalitis. RVFV is endemic to parts of Africa and the Arabian Peninsula, but there is significant concern regarding its introduction into non-endemic regions and the potentially devastating effect to livestock populations with concurrent infections of humans. To date, there is little detailed data directly comparing the host response to infection with wild-type or vaccine strains of RVFV and correlation with viral pathogenesis. Here we characterized clinical and systemic immune responses to infection with wild-type strain ZH501 or IND vaccine strain MP-12 in the C57BL/6 mouse. Animals infected with live-attenuated MP-12 survived productive viral infection with little evidence of clinical disease and minimal cytokine response in evaluated tissues. In contrast, ZH501 infection was lethal, caused depletion of lymphocytes and platelets and elicited a strong, systemic cytokine response which correlated with high virus titers and significant tissue pathology. Lymphopenia and platelet depletion were indicators of disease onset with indications of lymphocyte recovery correlating with increases in G-CSF production. RVFV is hepatotropic and in these studies significant clinical and histological data supported these findings; however, significant evidence of a pro-inflammatory response in the liver was not apparent. Rather, viral infection resulted in a chemokine response indicating infiltration of immunoreactive cells, such as neutrophils, which was supported by histological data. In brains of ZH501 infected mice, a significant chemokine and pro-inflammatory cytokine response was evident, but with little pathology indicating meningoencephalitis. These data suggest that RVFV pathogenesis in mice is associated with a loss of liver function due to liver necrosis and hepatitis yet the long-term course of disease for those that

  18. Role of CYP2B6 and CYP3A4 in the in vitro N-dechloroethylation of (R)- and (S)-ifosfamide in human liver microsomes.

    Science.gov (United States)

    Granvil, C P; Madan, A; Sharkawi, M; Parkinson, A; Wainer, I W

    1999-04-01

    The central nervous system toxicity of ifosfamide (IFF), a chiral antineoplastic agent, is thought to be dependent on its N-dechloroethylation by hepatic cytochrome P-450 (CYP) enzymes. The purpose of this study was to identify the human CYPs responsible for IFF-N-dechloroethylation and their corresponding regio- and enantioselectivities. IFF exists in two enantiomeric forms, (R) - and (S)-IFF, which can be dechloroethylated at either the N2 or N3 positions, producing the corresponding (R,S)-2-dechloroethyl-IFF [(R, S)-2-DCE-IFF] and (R,S)-3-dechloroethyl-IFF [(R,S)-3-DCE-IFF]. The results of the present study suggest that the production of (R)-2-DCE-IFF and (S)-3-DCE-IFF from (R)-IFF is catalyzed by different CYPs as is the production of (S)-2-DCE-IFF and (R)-3-DCE-IFF from (S)-IFF. In vitro studies with a bank of human liver microsomes revealed that the sample-to-sample variation in the production of (S)-3-DCE-IFF from (R)-IFF and (S)-2-DCE-IFF from (S)-IFF was highly correlated with the levels of (S)-mephenytoin N-demethylation (CYP2B6), whereas (R)-2-DCE-IFF production from (R)-IFF and (R)-3-DCE-IFF production from (S)-IFF were both correlated with the activity of testosterone 6beta-hydroxylation (CYP3A4/5). Experiments with cDNA-expressed P-450 and antibody and chemical inhibition studies supported the conclusion that the formation of (S)-3-DCE-IFF and (S)-2-DCE-IFF is catalyzed primarily by CYP2B6, whereas (R)-2-DCE-IFF and (R)-3-DCE-IFF are primarily the result of CYP3A4/5 activity.

  19. Fenproporex N-dealkylation to amphetamine--enantioselective in vitro studies in human liver microsomes as well as enantioselective in vivo studies in Wistar and Dark Agouti rats.

    Science.gov (United States)

    Kraemer, Thomas; Pflugmann, Thomas; Bossmann, Michael; Kneller, Nicole M; Peters, Frank T; Paul, Liane D; Springer, Dietmar; Staack, Roland F; Maurer, Hans H

    2004-09-01

    Fenproporex (FP) is known to be N-dealkylated to R(-)-amphetamine (AM) and S(+)-amphetamine. Involvement of the polymorphic cytochrome P450 (CYP) isoform CYP2D6 in metabolism of such amphetamine precursors is discussed controversially in literature. In this study, the human hepatic CYPs involved in FP dealkylation were identified using recombinant CYPs and human liver microsomes (HLM). These studies revealed that not only CYP2D6 but also CYP1A2, CYP2B6 and CYP3A4 catalyzed this metabolic reaction for both enantiomers with slight preference for the S(+)-enantiomer. Formation of amphetamine was not significantly changed by quinidine and was not different in poor metabolizer HLM compared to pooled HLM. As in vivo experiments, blood levels of R(-)-amphetamine and S(+)-amphetamine formed after administration of FP were determined in female Dark Agouti rats (fDA), a model of the human CYP2D6 poor metabolizer phenotype (PM), male Dark Agouti rats (mDA), an intermediate model, and in male Wistar rats (WI), a model of the human CYP2D6 extensive metabolizer phenotype. Analysis of the plasma samples showed that fDA exhibited significantly higher plasma levels of both amphetamine enantiomers compared to those of WI. Corresponding plasma levels in mDA were between those in fDA and WI. Furthermore, pretreatment of WI with the CYP2D inhibitor quinine resulted in significantly higher amphetamine plasma levels, which did not significantly differ from those in fDA. The in vivo studies suggested that CYP2D6 is not crucial to the N-dealkylation but to another metabolic step, most probably to the ring hydroxylation. Further studies are necessary for elucidating the role of CYP2D6 in FP hydroxylation.

  20. Kinetics of naphthalene metabolism in target and non-target tissues of rodents and in nasal and airway microsomes from the Rhesus monkey

    Energy Technology Data Exchange (ETDEWEB)

    Buckpitt, Alan, E-mail: arbuckpitt@ucdavis.edu [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Morin, Dexter [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Murphy, Shannon; Edwards, Patricia; Van Winkle, Laura [Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Center for Health and the Environment, UC Davis, Davis, CA 95616 United States (United States)

    2013-07-15

    Naphthalene produces species and cell selective injury to respiratory tract epithelial cells of rodents. In these studies we determined the apparent K{sub m}, V{sub max}, and catalytic efficiency (V{sub max}/K{sub m}) for naphthalene metabolism in microsomal preparations from subcompartments of the respiratory tract of rodents and non-human primates. In tissues with high substrate turnover, major metabolites were derived directly from naphthalene oxide with smaller amounts from conjugates of diol epoxide, diepoxide, and 1,2- and 1,4-naphthoquinones. In some tissues, different enzymes with dissimilar K{sub m} and V{sub max} appeared to metabolize naphthalene. The rank order of V{sub max} (rat olfactory epithelium > mouse olfactory epithelium > murine airways ≫ rat airways) correlated well with tissue susceptibility to naphthalene. The V{sub max} in monkey alveolar subcompartment was 2% that in rat nasal olfactory epithelium. Rates of metabolism in nasal compartments of the monkey were low. The catalytic efficiencies of microsomes from known susceptible tissues/subcompartments are 10 and 250 fold higher than in rat airway and monkey alveolar subcompartments, respectively. Although the strong correlations between catalytic efficiencies and tissue susceptibility suggest that non-human primate tissues are unlikely to generate metabolites at a rate sufficient to produce cellular injury, other studies showing high levels of formation of protein adducts support the need for additional studies. - Highlights: • Naphthalene is metabolized with high catalytic efficiency in susceptible tissue. • Naphthalene is metabolized at low catalytic efficiency in non-susceptible tissue. • Respiratory tissues of the non human primate metabolize naphthalene slowly.

  1. Sensitivity of mitochondria of the mouse liver cells to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shima, A [Tokyo Univ. (Japan). Faculty of Science

    1974-06-01

    In order to study the sensitivity of mitochondria (Mt) of the liver cells to radiation, 0.4 mg of riboflavine (RF) was intraperitoneally injected into mice which had been fed RF deficient food for 13 weeks. Three hours later 400 R of X-ray (190 KVP, 25 mA, 0.5 mmCu, 0.5 mmAl filter, FSD 61.5 cm, and HVL 0.80 mmCu) were irradiated to the whole body, and giant Mt of the liver cells were observed. When the liver cells were observed 24 hours after injection, neither giant Mt nor mitotic findings of Mt were found. All Mt observed were small (1.2 ..mu..), although mice received 400 R of X-ray.

  2. Renal Impairment with Sublethal Tubular Cell Injury in a Chronic Liver Disease Mouse Model.

    Directory of Open Access Journals (Sweden)

    Tokiko Ishida

    Full Text Available The pathogenesis of renal impairment in chronic liver diseases (CLDs has been primarily studied in the advanced stages of hepatic injury. Meanwhile, the pathology of renal impairment in the early phase of CLDs is poorly understood, and animal models to elucidate its mechanisms are needed. Thus, we investigated whether an existing mouse model of CLD induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC shows renal impairment in the early phase. Renal injury markers, renal histology (including immunohistochemistry for tubular injury markers and transmission electron microscopy, autophagy, and oxidative stress were studied longitudinally in DDC- and standard diet-fed BALB/c mice. Slight but significant renal dysfunction was evident in DDC-fed mice from the early phase. Meanwhile, histological examinations of the kidneys with routine light microscopy did not show definitive morphological findings, and electron microscopic analyses were required to detect limited injuries such as loss of brush border microvilli and mitochondrial deformities. Limited injuries have been recently designated as sublethal tubular cell injury. As humans with renal impairment, either with or without CLD, often show almost normal tubules, sublethal injury has been of particular interest. In this study, the injuries were associated with mitochondrial aberrations and oxidative stress, a possible mechanism for sublethal injury. Intriguingly, two defense mechanisms were associated with this injury that prevent it from progressing to apparent cell death: autophagy and single-cell extrusion with regeneration. Furthermore, the renal impairment of this model progressed to chronic kidney disease with interstitial fibrosis after long-term DDC feeding. These findings indicated that DDC induces renal impairment with sublethal tubular cell injury from the early phase, leading to chronic kidney disease. Importantly, this CLD mouse model could be useful for studying the

  3. Curcumin ameliorates liver damage and progression of NASH in NASH-HCC mouse model possibly by modulating HMGB1-NF-κB translocation.

    Science.gov (United States)

    Afrin, Rejina; Arumugam, Somasundaram; Rahman, Azizur; Wahed, Mir Imam Ibne; Karuppagounder, Vengadeshprabhu; Harima, Meilei; Suzuki, Hiroshi; Miyashita, Shizuka; Suzuki, Kenji; Yoneyama, Hiroyuki; Ueno, Kazuyuki; Watanabe, Kenichi

    2017-03-01

    Curcumin, a phenolic compound, has a wide spectrum of therapeutic effects such as antitumor, anti-inflammatory, anti-cancer and so on. The study aimed to investigate the underlying mechanisms of curcumin to protect liver damage and progression of non-alcoholic steatohepatitis (NASH) in a novel NASH-hepatocellular carcinoma (HCC) mouse model. To induce this model neonatal C57BL/6J male mice were exposed to low-dose streptozotocin and were fed a high-fat diet (HFD) from the age of 4weeks to 14weeks. Curcumin was given at 100mg/kg dose daily by oral gavage started at the age of 10weeks and continued until 14weeks along with HFD feeding. We found that curcumin improved the histopathological changes of the NASH liver via reducing the level of steatosis, fibrosis associated with decreasing serum aminotransferases. In addition, curcumin treatment markedly reduced the hepatic protein expression of oxidative stress, pro-inflammatory cytokines, and chemokines including interferon (IFN) γ, interleukin-1β and IFNγ-inducible protein 10, in NASH mice. Furthermore, curcumin treatment significantly reduced the cytoplasmic translocation of high mobility group box 1 (HMGB1) and the protein expression of toll like receptor 4. Nuclear translocation of nuclear factor kappa B (NF-κB) was also dramatically attenuated by the curcumin in NASH liver. Curcumin treatment effectively reduced the progression of NASH to HCC by suppressing the protein expression of glypican-3, vascular endothelial growth factor, and prothrombin in the NASH liver. Our data suggest that curcumin reduces the progression of NASH and liver damage, which may act via inhibiting HMGB1-NF-κB translocation. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Pyrroloquinoline-quinone suppresses liver fibrogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Dongwei Jia

    Full Text Available Liver fibrosis represents the consequences of a sustained wound healing response to chronic liver injuries, and its progression toward cirrhosis is the major cause of liver-related morbidity and mortality worldwide. However, anti-fibrotic treatment remains an unconquered area for drug development. Accumulating evidence indicate that oxidative stress plays a critical role in liver fibrogenesis. In this study, we found that PQQ, a natural anti-oxidant present in a wide variety of human foods, exerted potent anti-fibrotic and ROS-scavenging activity in Balb/C mouse models of liver fibrosis. The antioxidant activity of PQQ was involved in the modulation of multiple steps during liver fibrogenesis, including chronic liver injury, hepatic inflammation, as well as activation of hepatic stellate cells and production of extracellular matrix. PQQ also suppressed the up-regulation of RACK1 in activated HSCs in vivo and in vitro. Our data suggest that PQQ suppresses oxidative stress and liver fibrogenesis in mice, and provide rationale for the clinical application of PQQ in the prevention and treatment of liver fibrosis.

  5. Alcohol extract of North American ginseng (Panax quinquefolius) reduces fatty liver, dyslipidemia, and other complications of metabolic syndrome in a mouse model.

    Science.gov (United States)

    Singh, Ratnesh K; Lui, Edmund; Wright, David; Taylor, Adrian; Bakovic, Marica

    2017-09-01

    We investigated whether North American ginseng (Panax quinquefolius) could reduce development of the metabolic syndrome phenotype in a mouse model (ETKO) of the disease. Young ETKO mice have no disease but similar to humans start to develop the fatty liver, hypertriglyceridemia, obesity, and insulin resistance at 25-30 weeks of age, and the disease continues to progress with ageing. ETKO mice were orally given an ethanol extract of ginseng roots at 4 and 32 weeks of age. Treatments with ginseng eliminated the ETKO fatty liver, reduced hepatic and intestinal lipoprotein secretion, and reduced the level of circulating lipids. Improvements by ginseng treatments were manifested as a reduction in the expression of genes involved in the regulation of fatty acid and triglyceride (fat) synthesis and secretion by the lipoproteins on one hand, and the stimulation of fatty acid oxidation and triglyceride degradation by lipolysis on the other hand. These processes altogether improved glucose, fatty acid, and triglyceride metabolism, reduced liver fat load, and reversed the progression of metabolic syndrome. These data confirm that treatments with North American ginseng could alleviate metabolic syndrome through the maintenance of a better balance between glucose and fatty acid metabolism, lipoprotein secretion, and energy homeostasis in disease-prone states.

  6. Hydrogen isotope ratios of mouse tissues are influenced by a variety of factors other than diet

    International Nuclear Information System (INIS)

    DeNiro, M.J.; Epstein, S.

    1981-01-01

    Hydrogen isotopes are fractionated during biochemical reactions in a variety of organisms. A number of experiments have shown that the D/H ratios of animals and their tissues are not controlled solely by the D/H ratios of their food. The authors performed a simple experiment which indicated that the D/H ratios of a significant fraction of the organically bonded hydrogen in animal tissues must be determined by the isotopic composition of water that the samples encounter. Aliquots of dried mouse brain and liver and mouse food were exposed to water vapors of different D/H ratios prior to isotopic analysis. The results of the experiment showed that at least 16 percent of the hydrogen in mouse brain is exchangeable with the hydrogen of water; the corresponding values for mouse liver and mouse food were 25 to 29 percent

  7. Sex-dependent differences in phenobarbitane-induced oestradiol-2-hydroxylase activity in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Theron, C.N.; Neethling, A.C.; Taljaard, J.J.F. (Stellenbosch Univ. (South Africa). Dept. of Chemical Pathology)

    1981-08-15

    Oestradiol-2-hydroxylase (E/sub 2/-OH) activity was measured in liver and brain microsomes of 6-8-week-old Wistar rats. Phenobarbitone (75 mg/kg daily for 3 days) significantly increased enzyme activity in the liver of males and females, but there were striking differences between the two sexes. In males the enzyme activity was increased by 37% over control values and in females by 200%. The total microsomol cytochrome P-450 content was increased by 75% in males and by 82% in females. The apparent Michaelis constant (K(m)) of E/sub 2/-OH for 17..beta..-oestradiol in untreated males (9,8 ..mu..M) and females (9,2 ..mu..M) did not differ significantly. Phenobarbitone treatment, however, tended to reduce the apparent K(m) in males (8,2 ..mu..M) and to increase it in females (18,7 ..mu..M). E/sub 2/-OH activity was also detected in brain tissue of both sexes, but it was 50-200-fold lower than in the liver and was not increased by phenobarbitone.

  8. Sex-dependent differences in phenobarbitane-induced oestradiol-2-hydroxylase activity in rat liver

    International Nuclear Information System (INIS)

    Theron, C.N.; Neethling, A.C.; Taljaard, J.J.F.

    1981-01-01

    Oestradiol-2-hydroxylase (E 2 -OH) activity was measured in liver and brain microsomes of 6-8-week-old Wistar rats. Phenobarbitone (75 mg/kg daily for 3 days) significantly increased enzyme activity in the liver of males and females, but there were striking differences between the two sexes. In males the enzyme activity was increased by 37% over control values and in females by 200%. The total microsomol cytochrome P-450 content was increased by 75% in males and by 82% in females. The apparent Michaelis constant (K(m)) of E 2 -OH for 17β-oestradiol in untreated males (9,8 μM) and females (9,2 μM) did not differ significantly. Phenobarbitone treatment, however, tended to reduce the apparent K(m) in males (8,2 μM) and to increase it in females (18,7 μM). E 2 -OH activity was also detected in brain tissue of both sexes, but it was 50-200-fold lower than in the liver and was not increased by phenobarbitone

  9. NAD(P)H:quinone oxidoreductase expression in Cyp1a-knockout and CYP1A-humanized mouse lines and its effect on bioactivation of the carcinogen aristolochic acid I

    Energy Technology Data Exchange (ETDEWEB)

    Levova, Katerina; Moserova, Michaela [Department of Biochemistry, Faculty of Science, Charles University, Prague (Czech Republic); Nebert, Daniel W. [Department of Environmental Health, University of Cincinnati Medical Center, Cincinnati (United States); Phillips, David H. [Analytical and Environmental Sciences Division, MRC-HPA Centre for Environment and Health, King' s College London, London (United Kingdom); Frei, Eva [Division of Preventive Oncology, National Center for Tumor Diseases, German Cancer Research Center (DKFZ), Heidelberg (Germany); Schmeiser, Heinz H. [Research Group Genetic Alterations in Carcinogenesis, German Cancer Research Center (DKFZ), Heidelberg (Germany); Arlt, Volker M. [Analytical and Environmental Sciences Division, MRC-HPA Centre for Environment and Health, King' s College London, London (United Kingdom); Stiborova, Marie, E-mail: stiborov@natur.cuni.cz [Department of Biochemistry, Faculty of Science, Charles University, Prague (Czech Republic)

    2012-12-15

    Aristolochic acid causes a specific nephropathy (AAN), Balkan endemic nephropathy, and urothelial malignancies. Using Western blotting suitable to determine protein expression, we investigated in several transgenic mouse lines expression of NAD(P)H:quinone oxidoreductase (NQO1)—the most efficient cytosolic enzyme that reductively activates aristolochic acid I (AAI). The mouse tissues used were from previous studies [Arlt et al., Chem. Res. Toxicol. 24 (2011) 1710; Stiborova et al., Toxicol. Sci. 125 (2012) 345], in which the role of microsomal cytochrome P450 (CYP) enzymes in AAI metabolism in vivo had been determined. We found that NQO1 levels in liver, kidney and lung of Cyp1a1(−/−), Cyp1a2(−/−) and Cyp1a1/1a2(−/−) knockout mouse lines, as well as in two CYP1A-humanized mouse lines harboring functional human CYP1A1 and CYP1A2 and lacking the mouse Cyp1a1/1a2 orthologs, differed from NQO1 levels in wild-type mice. NQO1 protein and enzymic activity were induced in hepatic and renal cytosolic fractions isolated from AAI-pretreated mice, compared with those in untreated mice. Furthermore, this increase in hepatic NQO1 enzyme activity was associated with bioactivation of AAI and elevated AAI-DNA adduct levels in ex vivo incubations of cytosolic fractions with DNA and AAI. In conclusion, AAI appears to increase its own metabolic activation by inducing NQO1, thereby enhancing its own genotoxic potential. Highlights: ► NAD(P)H:quinone oxidoreductase expression in Cyp1a knockout and humanized CYP1A mice ► Reductive activation of the nephrotoxic and carcinogenic aristolochic acid I (AAI) ► NAD(P)H:quinone oxidoreductase is induced in mice treated with AAI. ► Induced hepatic enzyme activity resulted in elevated AAI-DNA adduct levels.

  10. NAD(P)H:quinone oxidoreductase expression in Cyp1a-knockout and CYP1A-humanized mouse lines and its effect on bioactivation of the carcinogen aristolochic acid I

    International Nuclear Information System (INIS)

    Levova, Katerina; Moserova, Michaela; Nebert, Daniel W.; Phillips, David H.; Frei, Eva; Schmeiser, Heinz H.; Arlt, Volker M.; Stiborova, Marie

    2012-01-01

    Aristolochic acid causes a specific nephropathy (AAN), Balkan endemic nephropathy, and urothelial malignancies. Using Western blotting suitable to determine protein expression, we investigated in several transgenic mouse lines expression of NAD(P)H:quinone oxidoreductase (NQO1)—the most efficient cytosolic enzyme that reductively activates aristolochic acid I (AAI). The mouse tissues used were from previous studies [Arlt et al., Chem. Res. Toxicol. 24 (2011) 1710; Stiborova et al., Toxicol. Sci. 125 (2012) 345], in which the role of microsomal cytochrome P450 (CYP) enzymes in AAI metabolism in vivo had been determined. We found that NQO1 levels in liver, kidney and lung of Cyp1a1(−/−), Cyp1a2(−/−) and Cyp1a1/1a2(−/−) knockout mouse lines, as well as in two CYP1A-humanized mouse lines harboring functional human CYP1A1 and CYP1A2 and lacking the mouse Cyp1a1/1a2 orthologs, differed from NQO1 levels in wild-type mice. NQO1 protein and enzymic activity were induced in hepatic and renal cytosolic fractions isolated from AAI-pretreated mice, compared with those in untreated mice. Furthermore, this increase in hepatic NQO1 enzyme activity was associated with bioactivation of AAI and elevated AAI-DNA adduct levels in ex vivo incubations of cytosolic fractions with DNA and AAI. In conclusion, AAI appears to increase its own metabolic activation by inducing NQO1, thereby enhancing its own genotoxic potential. Highlights: ► NAD(P)H:quinone oxidoreductase expression in Cyp1a knockout and humanized CYP1A mice ► Reductive activation of the nephrotoxic and carcinogenic aristolochic acid I (AAI) ► NAD(P)H:quinone oxidoreductase is induced in mice treated with AAI. ► Induced hepatic enzyme activity resulted in elevated AAI-DNA adduct levels.

  11. Conditional loss of heparin-binding EGF-like growth factor results in enhanced liver fibrosis after bile duct ligation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, Takayo; Yoshida, Yuichi [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Kiso, Shinichi, E-mail: kiso@gh.med.osaka-u.ac.jp [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Kizu, Takashi; Furuta, Kunimaro; Ezaki, Hisao; Hamano, Mina; Egawa, Mayumi; Chatani, Norihiro; Kamada, Yoshihiro [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Imai, Yasuharu [Department of Gastroenterology, Ikeda Municipal Hospital, Ikeda, Osaka (Japan); Higashiyama, Shigeki [Department of Biochemistry and Molecular Genetics, Ehime University, Graduate School of Medicine and Department of Cell Growth and Tumor Regulation, Proteo-Medicine Research Center (ProMRes), Ehime University, Shitsukawa, Toon, Ehime (Japan); Iwamoto, Ryo; Mekada, Eisuke [Department of Cell Biology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka (Japan); Takehara, Tetsuo [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan)

    2013-07-26

    Highlights: •HB-EGF expression was increased during the development of liver fibrosis. •Conditional HB-EGF knockout mouse showed enhanced experimental liver fibrosis. •HB-EGF antagonized TGF-β-induced activation of hepatic stellate cells. •We report a possible protective role of HB-EGF in cholestatic liver fibrosis. -- Abstract: Our aims were to evaluate the involvement of heparin-binding EGF-like growth factor (HB-EGF) in liver fibrogenesis of humans and mice and to elucidate the effect of HB-EGF deficiency on cholestatic liver fibrosis using conditional HB-EGF knockout (KO) mice. We first demonstrated that gene expression of HB-EGF had a positive significant correlation with that of collagen in human fibrotic livers, and was increased in bile duct ligation (BDL)-induced fibrotic livers in mouse. We then generated conditional HB-EGF knockout (KO) mice using the interferon inducible Mx-1 promoter driven Cre recombinase transgene and wild type (WT) and KO mice were subjected to BDL. After BDL, KO mice exhibited enhanced liver fibrosis with increased expression of collagen, compared with WT mice. Finally, we used mouse hepatic stellate cells (HSCs) to examine the role of HB-EGF in the activation of these cells and showed that HB-EGF antagonized TGF-β-induced gene expression of collagen in mouse primary HSCs. Interestingly, HB-EGF did not prevent the TGF-β-induced nuclear accumulation of Smad3, but did lead to stabilization of the Smad transcriptional co-repressor TG-interacting factor. In conclusion, our data suggest a possible protective role of HB-EGF in cholestatic liver fibrosis.

  12. Conditional loss of heparin-binding EGF-like growth factor results in enhanced liver fibrosis after bile duct ligation in mice

    International Nuclear Information System (INIS)

    Takemura, Takayo; Yoshida, Yuichi; Kiso, Shinichi; Kizu, Takashi; Furuta, Kunimaro; Ezaki, Hisao; Hamano, Mina; Egawa, Mayumi; Chatani, Norihiro; Kamada, Yoshihiro; Imai, Yasuharu; Higashiyama, Shigeki; Iwamoto, Ryo; Mekada, Eisuke; Takehara, Tetsuo

    2013-01-01

    Highlights: •HB-EGF expression was increased during the development of liver fibrosis. •Conditional HB-EGF knockout mouse showed enhanced experimental liver fibrosis. •HB-EGF antagonized TGF-β-induced activation of hepatic stellate cells. •We report a possible protective role of HB-EGF in cholestatic liver fibrosis. -- Abstract: Our aims were to evaluate the involvement of heparin-binding EGF-like growth factor (HB-EGF) in liver fibrogenesis of humans and mice and to elucidate the effect of HB-EGF deficiency on cholestatic liver fibrosis using conditional HB-EGF knockout (KO) mice. We first demonstrated that gene expression of HB-EGF had a positive significant correlation with that of collagen in human fibrotic livers, and was increased in bile duct ligation (BDL)-induced fibrotic livers in mouse. We then generated conditional HB-EGF knockout (KO) mice using the interferon inducible Mx-1 promoter driven Cre recombinase transgene and wild type (WT) and KO mice were subjected to BDL. After BDL, KO mice exhibited enhanced liver fibrosis with increased expression of collagen, compared with WT mice. Finally, we used mouse hepatic stellate cells (HSCs) to examine the role of HB-EGF in the activation of these cells and showed that HB-EGF antagonized TGF-β-induced gene expression of collagen in mouse primary HSCs. Interestingly, HB-EGF did not prevent the TGF-β-induced nuclear accumulation of Smad3, but did lead to stabilization of the Smad transcriptional co-repressor TG-interacting factor. In conclusion, our data suggest a possible protective role of HB-EGF in cholestatic liver fibrosis

  13. Osteopontin regulates the cross-talk between phosphatidylcholine and cholesterol metabolism in mouse liver.

    Science.gov (United States)

    Nuñez-Garcia, Maitane; Gomez-Santos, Beatriz; Buqué, Xabier; García-Rodriguez, Juan L; Romero, Marta R; Marin, Jose J G; Arteta, Beatriz; García-Monzón, Carmelo; Castaño, Luis; Syn, Wing-Kin; Fresnedo, Olatz; Aspichueta, Patricia

    2017-09-01

    Osteopontin (OPN) is involved in different liver pathologies in which metabolic dysregulation is a hallmark. Here, we investigated whether OPN could alter liver, and more specifically hepatocyte, lipid metabolism and the mechanism involved. In mice, lack of OPN enhanced cholesterol 7α-hydroxylase (CYP7A1) levels and promoted loss of phosphatidylcholine (PC) content in liver; in vivo treatment with recombinant (r)OPN caused opposite effects. rOPN directly decreased CYP7A1 levels through activation of focal adhesion kinase-AKT signaling in hepatocytes. PC content was also decreased in OPN-deficient (OPN-KO) hepatocytes in which de novo FA and PC synthesis was lower, whereas cholesterol (CHOL) synthesis was higher, than in WT hepatocytes. In vivo inhibition of cholesterogenesis normalized liver PC content in OPN-KO mice, demonstrating that OPN regulates the cross-talk between liver CHOL and PC metabolism. Matched liver and serum samples showed a positive correlation between serum OPN levels and liver PC and CHOL concentration in nonobese patients with nonalcoholic fatty liver. In conclusion, OPN regulates CYP7A1 levels and the metabolic fate of liver acetyl-CoA as a result of CHOL and PC metabolism interplay. The results suggest that CYP7A1 is a main axis and that serum OPN could disrupt liver PC and CHOL metabolism, contributing to nonalcoholic fatty liver disease progression in nonobese patients.

  14. UPTAKE OF [3H]-COLCHICINE INTO BRAIN AND LIVER OF MOUSE, RAT, AND CHICK

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Edward L.; Alberti, Marie Hebert; Flood, James F.

    1980-07-01

    The uptake of [ring A-4-{sup 3}H] colchicine and [ring C-methoxy-{sup 3}H]colchicine has been compared in mice from 1 to 24 hr after administration. Less radioactivity was found in brain after administration of ring-labeled colchicine than after administration of the methoxy-labeled colchicine. Three hr after administration of ring-labeled colchicine, 5% of the label was in liver and about 0.01% of the label was present in brain. Forty percent of the brain radioactivity was bound to tubulin as determined by vinblastine precipitation. After 3 hr, an average of 8% of the radioactivity from methoxy-labeled colchicine was found in the liver and 0.16% in brain. However, less than 5% of the activity in brain was precipitated by vinblastine, and the colchicine equivalent was comparable to that found after administration of the ring-labeled colchicine. The amount of colchicine entering mouse brain after subcutaneous injection is comparable to the minimum behaviorally effective dose when administered to the caudate. The metabolism of [ring C-methoxy-{sup 3}H] and [ring A-{sup 3}H]colchicine was also studied in rats. the general pattern was similar to mice; less radioactivity was found in brain after administration of the ring-labeled alkoloid than after administration of methoxy-labeled colchicine. Again, 40-50% of ring-labeled colchicine was precipitated by vinblastine. A much smaller percentage of the methoxy-labeled drug was precipitated by vinblastine than of the ring A-labeled colchicine. These experiments, together with behavioral experiments [7], support the hypotheses that structural alteration in synapses by recently synthesized proteins which are transported down the axons and dendrites may be an essential process for long-term memory formation.

  15. Sensitivity of mitochondria of the mouse liver cells to radiation

    International Nuclear Information System (INIS)

    Shima, Akihiro

    1974-01-01

    In order to study the sensitivity of mitochondria (Mt) of the liver cells to radiation, 0.4 mg of riboflavine (RF) was intraperitoneally injected into mice which had been fed RF deficient food for 13 weeks. Three hours later 400 R of X-ray (190 KVP, 25 mA, 0.5 mmCu, 0.5 mmAl filter, FSD 61.5 cm, and HVL 0.80 mmCu) were irradiated to the whole body, and giant Mt of the liver cells were observed. When the liver cells were observed 24 hours after injection, neither giant Mt nor mitotic findings of Mt were found. All Mt observed were small (1.2 μ), although mice received 400 R of X-ray. (Serizawa, K.)

  16. Autoimmune liver serology: current diagnostic and clinical challenges.

    Science.gov (United States)

    Bogdanos, Dimitrios-P; Invernizzi, Pietro; Mackay, Ian-R; Vergani, Diego

    2008-06-07

    Liver-related autoantibodies are crucial for the correct diagnosis and classification of autoimmune liver diseases (AiLD), namely autoimmune hepatitis types 1 and 2 (AIH-1 and 2), primary biliary cirrhosis (PBC), and the sclerosing cholangitis variants in adults and children. AIH-1 is specified by anti-nuclear antibody (ANA) and smooth muscle antibody (SMA). AIH-2 is specified by antibody to liver kidney microsomal antigen type-1 (anti-LKM1) and anti-liver cytosol type 1 (anti-LC1). SMA, ANA and anti-LKM antibodies can be present in de-novo AIH following liver transplantation. PBC is specified by antimitochondrial antibodies (AMA) reacting with enzymes of the 2-oxo-acid dehydrogenase complexes (chiefly pyruvate dehydrogenase complex E2 subunit) and disease-specific ANA mainly reacting with nuclear pore gp210 and nuclear body sp100. Sclerosing cholangitis presents as at least two variants, first the classical primary sclerosing cholangitis (PSC) mostly affecting adult men wherein the only (and non-specific) reactivity is an atypical perinuclear antineutrophil cytoplasmic antibody (p-ANCA), also termed perinuclear anti-neutrophil nuclear antibodies (p-ANNA) and second the childhood disease called autoimmune sclerosing cholangitis (ASC) with serological features resembling those of type 1 AIH. Liver diagnostic serology is a fast-expanding area of investigation as new purified and recombinant autoantigens, and automated technologies such as ELISAs and bead assays, become available to complement (or even compete with) traditional immunofluorescence procedures. We survey for the first time global trends in quality assurance impacting as it does on (1) manufacturers/purveyors of kits and reagents, (2) diagnostic service laboratories that fulfill clinicians' requirements, and (3) the end-user, the physician providing patient care, who must properly interpret test results in the overall clinical context.

  17. Human mesenchymal stem cells towards non-alcoholic steatohepatitis in an immunodeficient mouse model

    International Nuclear Information System (INIS)

    Winkler, Sandra; Borkham-Kamphorst, Erawan; Stock, Peggy; Brückner, Sandra; Dollinger, Matthias; Weiskirchen, Ralf; Christ, Bruno

    2014-01-01

    Non-alcoholic steatohepatitis (NASH) is a frequent clinical picture characterised by hepatic inflammation, lipid accumulation and fibrosis. When untreated, NASH bears a high risk of developing liver cirrhosis and consecutive hepatocellular carcinoma requiring liver transplantation in its end-stage. However, donor organ scarcity has prompted the search for alternatives, of which hepatocyte or stem cell-derived hepatocyte transplantation are regarded auspicious options of treatment. Mesenchymal stem cells (MSC) are able to differentiate into hepatocyte-like cells and thus may represent an alternative cell source to primary hepatocytes. In addition these cells feature anti-inflammatory and pro-regenerative characteristics, which might favour liver recovery from NASH. The aim of this study was to investigate the potential benefit of hepatocyte-like cells derived from human bone marrow MSC in a mouse model of diet-induced NASH. Seven days post-transplant, human hepatocyte-like cells were found in the mouse liver parenchyma. Triglyceride depositions were lowered in the liver but restored to normal in the blood. Hepatic inflammation was attenuated as verified by decreased expression of the acute phase protein serum amyloid A, inflammation-associated markers (e.g. lipocalin 2), as well as the pro-inflammatory cytokine TNFα. Moreover, the proliferation of host hepatocytes that indicate the regenerative capacity in livers receiving cell transplants was enhanced. Transplantation of MSC-derived human hepatocyte-like cells corrects NASH in mice by restoring triglyceride depositions, reducing inflammation and augmenting the regenerative capacity of the liver. - Highlights: • First time to show NASH in an immune-deficient mouse model. • Human MSC attenuate NASH and improve lipid homeostasis. • MSC act anti-fibrotic and augment liver regeneration by stimulation of proliferation. • Pre-clinical assessment of human MSC for stem cell-based therapy of NASH

  18. Human mesenchymal stem cells towards non-alcoholic steatohepatitis in an immunodeficient mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, Sandra, E-mail: sandra.pelz@medizin.uni-leipzig.de [Applied Molecular Hepatology Laboratory, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, University Hospital Leipzig, Liebigstraße 21, D-04103 Leipzig (Germany); Borkham-Kamphorst, Erawan, E-mail: ekamphorst@ukaachen.de [Institute of Clinical Chemistry and Pathobiochemistry, RWTH University Hospital Aachen, Pauwelsstraße 30, D-52074 Aachen (Germany); Stock, Peggy, E-mail: peggy.stock@medizin.uni-leipzig.de [Applied Molecular Hepatology Laboratory, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, University Hospital Leipzig, Liebigstraße 21, D-04103 Leipzig (Germany); Brückner, Sandra, E-mail: sandra.brueckner@medizin.uni-leipzig.de [Applied Molecular Hepatology Laboratory, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, University Hospital Leipzig, Liebigstraße 21, D-04103 Leipzig (Germany); Dollinger, Matthias, E-mail: matthias.dollinger@uniklinik-ulm.de [Department for Internal Medicine I, University Hospital Ulm, Albert-Einstein-Allee 23, D-89081 Ulm (Germany); Weiskirchen, Ralf, E-mail: rweiskirchen@ukaachen.de [Institute of Clinical Chemistry and Pathobiochemistry, RWTH University Hospital Aachen, Pauwelsstraße 30, D-52074 Aachen (Germany); Christ, Bruno, E-mail: bruno.christ@medizin.uni-leipzig.de [Applied Molecular Hepatology Laboratory, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, University Hospital Leipzig, Liebigstraße 21, D-04103 Leipzig (Germany); Translational Centre for Regenerative Medicine (TRM), University of Leipzig, Leipzig (Germany)

    2014-08-15

    Non-alcoholic steatohepatitis (NASH) is a frequent clinical picture characterised by hepatic inflammation, lipid accumulation and fibrosis. When untreated, NASH bears a high risk of developing liver cirrhosis and consecutive hepatocellular carcinoma requiring liver transplantation in its end-stage. However, donor organ scarcity has prompted the search for alternatives, of which hepatocyte or stem cell-derived hepatocyte transplantation are regarded auspicious options of treatment. Mesenchymal stem cells (MSC) are able to differentiate into hepatocyte-like cells and thus may represent an alternative cell source to primary hepatocytes. In addition these cells feature anti-inflammatory and pro-regenerative characteristics, which might favour liver recovery from NASH. The aim of this study was to investigate the potential benefit of hepatocyte-like cells derived from human bone marrow MSC in a mouse model of diet-induced NASH. Seven days post-transplant, human hepatocyte-like cells were found in the mouse liver parenchyma. Triglyceride depositions were lowered in the liver but restored to normal in the blood. Hepatic inflammation was attenuated as verified by decreased expression of the acute phase protein serum amyloid A, inflammation-associated markers (e.g. lipocalin 2), as well as the pro-inflammatory cytokine TNFα. Moreover, the proliferation of host hepatocytes that indicate the regenerative capacity in livers receiving cell transplants was enhanced. Transplantation of MSC-derived human hepatocyte-like cells corrects NASH in mice by restoring triglyceride depositions, reducing inflammation and augmenting the regenerative capacity of the liver. - Highlights: • First time to show NASH in an immune-deficient mouse model. • Human MSC attenuate NASH and improve lipid homeostasis. • MSC act anti-fibrotic and augment liver regeneration by stimulation of proliferation. • Pre-clinical assessment of human MSC for stem cell-based therapy of NASH.

  19. Immunohistochemical examination of effects of kefir, koumiss and commercial probiotic capsules on platelet derived growth factor-c and platelet derived growth factor receptor-alpha expression in mouse liver and kidney.

    Science.gov (United States)

    Bakir, B; Sari, E K; Aydin, B D; Yildiz, S E

    2015-04-01

    We investigated using immunohistochemistry the effects of kefir, koumiss and commercial probiotic capsules on the expression of platelet derived growth factor-c (PDGF-C) and platelet derived growth factor receptor-alpha (PDGFR-α) in mouse liver and kidney. Mice were assigned to four groups: group 1 was given commercial probiotic capsules, group 2 was given kefir, group 3 was given koumiss and group 4 was untreated. After oral administration for 15 days, body weights were recorded and liver and kidney tissue samples were obtained. Hematoxylin and eosin staining was used to examine histology. PDGF-C and PDGFR-α in liver and kidney were localized using the streptavidin-biotin peroxidase complex method (ABC). We found that the weights of the mice in the kefir, koumiss and commercial probiotic capsules groups increased compared to the control group. No differences in liver and kidney histology were observed in any of the experimental groups. Kefir, koumiss and the commercial probiotic preparation increased PDGF-C and PDGFR-α expression.

  20. Pharmacokinetic studies on the hepatotoxicity of luteoskyrin, 1. Intracellular distribution of radioactivity in the liver of mice administered /sup 3/H-luteoskyrin

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, I [Tokyo Univ. (Japan). Inst. for Medical Science; Hayashi, T; Ueno, Y

    1974-08-01

    Intracellular distribution of the radioactivity derived from /sup 3/H-luteoskyrin in mouse liver was investigated. It was revealed that luteoskyrin has a high affinity to mitochondria and cell debris of mouse liver cells. This characteristic distribution pattern in the liver cells may be responsible for the mitochondrial impairment and the age and sex differences in the susceptibility of mice to this mycotoxin. (auth)

  1. Fungal microsomes in a biotransformation perspective: protein nature of membrane-associated reactions

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Kateřina; Mikesková, Hana; Petráčková, Denisa

    2013-01-01

    Roč. 97, č. 24 (2013), s. 10263-10273 ISSN 0175-7598 R&D Projects: GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Fungal microsomes * Cytochrome P450 * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 3.811, year: 2013

  2. Differential gene expression in mouse liver associated with the hepatoprotective effect of clofibrate

    International Nuclear Information System (INIS)

    Moffit, Jeffrey S.; Koza-Taylor, Petra H.; Holland, Ricky D.; Thibodeau, Michael S.; Beger, Richard D.; Lawton, Michael P.; Manautou, Jose E.

    2007-01-01

    Pretreatment of mice with the peroxisome proliferator clofibrate (CFB) protects against acetaminophen (APAP)-induced hepatotoxicity. Previous studies have shown that activation of the nuclear peroxisome proliferator activated receptor-alpha (PPARα) is required for this effect. The present study utilizes gene expression profile analysis to identify potential pathways contributing to PPARα-mediated hepatoprotection. Gene expression profiles were compared between wild type and PPARα-null mice pretreated with vehicle or CFB (500 mg/kg, i.p., daily for 10 days) and then challenged with APAP (400 mg/kg, p.o.). Total hepatic RNA was isolated 4 h after APAP treatment and hybridized to Affymetrix Mouse Genome MGU74 v2.0 GeneChips. Gene expression analysis was performed utilizing GeneSpring (registered) software. Our analysis identified 53 genes of interest including vanin-1, cell cycle regulators, lipid-metabolizing enzymes, and aldehyde dehydrogenase 2, an acetaminophen binding protein. Vanin-1 could be important for CFB-mediated hepatoprotection because this protein is involved in the synthesis of cysteamine and cystamine. These are potent antioxidants capable of ameliorating APAP toxicity in rodents and humans. HPLC-ESI/MS/MS analysis of liver extracts indicates that enhanced vanin-1 gene expression results in elevated cystamine levels, which could be mechanistically associated with CFB-mediated hepatoprotection

  3. Effects of phenobarbital pretreatment on the in vivo metabolism of carbaryl in rats

    International Nuclear Information System (INIS)

    Knight, E.V.; Alvares, A.P.; Chin, B.H.

    1987-01-01

    Phenobarbital (PB) pretreatment of animals is known to induce the activity of drug-metabolizing enzymes in liver microsomes. Previous studies showed that incubation of carbaryl with microsomes obtained from livers of untreated or PB-treated rats resulted in little or no oxidative metabolism of the substrate. In addition, no spectral interactions were observed when carbaryl was added to hepatic microsomal suspensions. The present study was carried out to determine the effect of PB pretreatment on the in vivo metabolism of carbaryl in rats

  4. Mechanism of impaired regeneration of fatty liver in mouse partial hepatectomy model.

    Science.gov (United States)

    Murata, Hiroshi; Yagi, Takahito; Iwagaki, Hiromi; Ogino, Tetsuya; Sadamori, Hiroshi; Matsukawa, Hiroyoshi; Umeda, Yuzoh; Haga, Sanae; Takaka, Noriaki; Ozaki, Michitaka

    2007-12-01

    The mechanism of injury in steatotic liver under pathological conditions been extensively examined. However, the mechanism of an impaired regeneration is still not well understood. The aim of this study was to analyze the mechanism of impaired regeneration of steatotic liver after partial hepatectomy (PH). db/db fatty mice and lean littermates were used for the experiments. Following 70% PH, the survival rate and recovery of liver mass were examined. Liver tissue was histologically examined and analyzed by western blotting and RT-PCR. Of 35 db/db mice, 25 died within 48 h of PH, while all of the control mice survived. Liver regeneration of surviving db/db mice was largely impaired. In db/db mice, mitosis of hepatocytes after PH was disturbed, even though proliferating cell nuclear antigen (PCNA) expression (G1 to S phase marker) in hepatocytes was equally observed in both mice groups. Interestingly, phosphorylation of Cdc2 in db/db mice was suppressed by reduced expression of Wee1 and Myt1, which phosphorylate Cdc2 in S to G2 phase. In steatotic liver, cell-cycle-related proliferative disorders occurred at mid-S phase after PCNA expression. Reduced expression of Wee1 and Myt1 kinases may therefore maintain Cdc2 in an unphosphorylated state and block cell cycle progression in mid-S phase. These kinases may be critical factors involved in the impaired liver regeneration in fatty liver.

  5. Genetic polymorphism of human cytochrome P-450 (S)-mephenytoin 4-hydroxylase. Studies with human autoantibodies suggest a functionally altered cytochrome P-450 isozyme as cause of the genetic deficiency

    International Nuclear Information System (INIS)

    Meier, U.T.; Meyer, U.A.

    1987-01-01

    The metabolism of the anticonvulsant mephenytoin is subject to a genetic polymorphism. In 2-5% of Caucasians and 18-23% of Japanese subjects a specific cytochrome P-450 isozyme, P-450 meph, is functionally deficient or missing. The authors have accumulated evidence that autoimmune antibodies observed in sera of patients with tienilic acid induced hepatitis (anti-liver kidney microsome 2 or anti-LKM2 antibodies) specifically recognize the cytochrome P-450 involved in the mephrenytoin hydroxylation polymorphism. This is demonstrated by immunoinhibition and immunoprecipitation of microsomal (S)-mephenytoin 4-hydroxylation activity and by the recognition by anti-LKM2 antibodies of a single [ 125 I]-protein band on immunoblots of human liver microsomes after sodium dodecyl sulfate-polyacrylamide gel electrophoresis or isoelectric focusing. The cytochrome P-450 recognized by anti-LKM2 antibodies was immunopurified from microsomes derived from livers of extensive (EM) or poor metabolizers (PM) of (S)-mephenytoin. Comparison of the EM-type cytochrome P-450 to that isolated from PM livers revealed no difference in regard to immuno-cross-reactivity, molecular weight, isoelectric point, relative content in microsomes, two-dimensional tryptic peptide maps, one-dimensional peptide maps with three proteases, amino acid composition, and amino-terminal protein sequence. Finally, the same protein was precipitated from microsomes prepared from the liver biopsy of a subject phenotyped in vivo as a poor metabolizer of mephenytoin. These data strongly suggest that the mephenytoin hydroxylation deficiency is caused by a minor structural change leading to a functionally altered cytochrome P-450 isozyme

  6. Continuous cell injury promotes hepatic tumorigenesis in cdc42-deficient mouse liver

    DEFF Research Database (Denmark)

    van Hengel, Jolanda; D'Hooge, Petra; Hooghe, Bart

    2008-01-01

    be required for liver function. METHODS: Mice in which Cdc42 was ablated in hepatocytes and bile duct cells were generated by Cre-loxP technology. Livers were examined by histologic, immunohistochemical, ultrastructural, and serum analysis to define the effect of loss of Cdc42 on liver structure. RESULTS...... of 2 months, the canaliculi between hepatocytes were greatly enlarged, although the tight junctions flanking the canaliculi appeared normal. Regular liver plates were absent. E-cadherin expression pattern and gap junction localization were distorted. Analysis of serum samples indicated cholestasis...

  7. Effect of bullfrog (Rana catesbeiana oil administered by gavage on the fatty acid composition and oxidative stress of mouse liver

    Directory of Open Access Journals (Sweden)

    L.P. Silva

    2004-10-01

    Full Text Available The aim of the present study was to investigate the effects of daily intragastric administration of bullfrog oil (oleic, linoleic and palmitoleic acid-rich oil, corresponding to 0.4% of body weight for four weeks, on fatty acid composition and oxidative stress (lipid peroxidation and catalase activity in mouse liver. The activities of aspartate aminotransferase (AST, alkaline phosphatase (ALP, alanine aminotransferase (ALT, and gamma-glutamyltransferase (GGT, biomarkers of tissue injury, were determined in liver homogenates and serum. The proportions of 18:2n-6, 20:4n-6, 20:5n-3, and 22:6n-3 (polyunsaturated fatty acids, from 37 to 60% in the total fatty acid content were increased in the liver of the bullfrog oil-treated group (P < 0.05 compared to control. At the same time, a significant decrease in the relative abundance of 14:0, 16:0, and 18:0 (saturated fatty acids, from 49 to 25% was observed. The hepatic content of thiobarbituric acid reactive substances (TBARS was increased from 2.3 ± 0.2 to 12.3 ± 0.3 nmol TBA-MDA/mg protein and catalase activity was increased from 840 ± 32 to 1110 ± 45 µmol reduced H2O2 min-1 mg protein-1 in the treated group. Bullfrog oil administration increased AST and ALP activities in the liver (from 234.10 ± 0.12 to 342.84 ± 0.13 and 9.38 ± 0.60 to 20.06 ± 0.27 U/g, respectively and in serum (from 95.41 ± 6.13 to 120.32 ± 3.15 and 234.75 ± 11.5 to 254.41 ± 2.73 U/l, respectively, suggesting that this treatment induced tissue damage. ALT activity was increased from 287.28 ± 0.29 to 315.98 ± 0.34 U/g in the liver but remained unchanged in serum, whereas the GGT activity was not affected by bullfrog oil treatment. Therefore, despite the interesting modulation of fatty acids by bullfrog oil, a possible therapeutic use requires care since some adverse effects were observed in liver.

  8. Mouse Precision-Cut Liver Slices as an ex Vivo Model To Study Idiosyncratic Drug-Induced Liver Injury

    NARCIS (Netherlands)

    Hadi, Mackenzie; Chen, Yixi; Starokozhko, Viktoriia; Groothuis, Geny M. M.; Merema, M.T.

    Idiosyncratic drug-induced liver injury (IDILI) has been the top reason for withdrawing drugs from the market or for black box warnings. IDILI may arise from the interaction of a drug's reactive metabolite with a mild inflammation that renders the liver more sensitive to injury resulting in

  9. [Structural reorganization and change in the lipid composition of rat liver microsomes in chlorophos poisoning].

    Science.gov (United States)

    Boldeskul, A E; Gubskiĭ, Iu I; Mel'nik, A A; Fal'kovskaia, E N

    1993-01-01

    The influence of chlorophos on the endoplasmatic reticulum of rat liver has been studied using the methods of gas-liquid chromatography and fluorescence. Experiments have demonstrated an increase of lysophosphatidylethanolamine, total phospholipids, unsaturated fatty acids (C20:4 n6, C18:1 n11, C18:1 n7) and a decrease of phosphatidylserine and phosphatidylethanolamine. Changes in microviscosity and surface charge were also shown.

  10. Microsomal prostaglandin E synthase-1 in rheumatic diseases

    Directory of Open Access Journals (Sweden)

    Marina eKorotkova

    2011-01-01

    Full Text Available Microsomal prostaglandin E synthase-1 (mPGES-1 is a well recognized target for the development of novel anti-inflammatory drugs that can reduce symptoms of inflammation in rheumatic diseases and other inflammatory conditions. In this review, we focus on mPGES-1 in rheumatic diseases with the aim to cover the most recent advances in the understanding of mPGES-1 in rheumatoid arthritis, osteoarthritis and inflammatory myopathies. Novel findings regarding regulation of mPGES1 cell expression as well as enzyme inhibitors are also summarized.

  11. Deciphering the Developmental Dynamics of the Mouse Liver Transcriptome.

    Directory of Open Access Journals (Sweden)

    Sumedha S Gunewardena

    Full Text Available During development, liver undergoes a rapid transition from a hematopoietic organ to a major organ for drug metabolism and nutrient homeostasis. However, little is known on a transcriptome level of the genes and RNA-splicing variants that are differentially regulated with age, and which up-stream regulators orchestrate age-specific biological functions in liver. We used RNA-Seq to interrogate the developmental dynamics of the liver transcriptome in mice at 12 ages from late embryonic stage (2-days before birth to maturity (60-days after birth. Among 21,889 unique NCBI RefSeq-annotated genes, 9,641 were significantly expressed in at least one age, 7,289 were differently regulated with age, and 859 had multiple (> = 2 RNA splicing-variants. Factor analysis showed that the dynamics of hepatic genes fall into six distinct groups based on their temporal expression. The average expression of cytokines, ion channels, kinases, phosphatases, transcription regulators and translation regulators decreased with age, whereas the average expression of peptidases, enzymes and transmembrane receptors increased with age. The average expression of growth factors peak between Day-3 and Day-10, and decrease thereafter. We identified critical biological functions, upstream regulators, and putative transcription modules that seem to govern age-specific gene expression. We also observed differential ontogenic expression of known splicing variants of certain genes, and 1,455 novel splicing isoform candidates. In conclusion, the hepatic ontogeny of the transcriptome ontogeny has unveiled critical networks and up-stream regulators that orchestrate age-specific biological functions in liver, and suggest that age contributes to the complexity of the alternative splicing landscape of the hepatic transcriptome.

  12. Protracted elimination of gold nanoparticles from mouse liver

    DEFF Research Database (Denmark)

    Sadauskas, Evaldas; Wallin, Håkan; Stoltenberg, Meredin

    2009-01-01

    The present study aims at revealing the fate of 40-nm gold nanoparticles after intravenous injections. The gold nanoparticles were traced histochemically with light and transmission electron microscopy using autometallographic (AMG) staining, and the gold content in the liver was determined with ...

  13. Glutamate Cysteine Ligase—Modulatory Subunit Knockout Mouse Shows Normal Insulin Sensitivity but Reduced Liver Glycogen Storage

    KAUST Repository

    Lavoie, Suzie

    2016-04-21

    Glutathione (GSH) deficits have been observed in several mental or degenerative illness, and so has the metabolic syndrome. The impact of a decreased glucose metabolism on the GSH system is well-known, but the effect of decreased GSH levels on the energy metabolism is unclear. The aim of the present study was to investigate the sensitivity to insulin in the mouse knockout (KO) for the modulatory subunit of the glutamate cysteine ligase (GCLM), the rate-limiting enzyme of GSH synthesis. Compared to wildtype (WT) mice, GCLM-KO mice presented with reduced basal plasma glucose and insulin levels. During an insulin tolerance test, GCLM-KO mice showed a normal fall in glycemia, indicating normal insulin secretion. However, during the recovery phase, plasma glucose levels remained lower for longer in KO mice despite normal plasma glucagon levels. This is consistent with a normal counterregulatory hormonal response but impaired mobilization of glucose from endogenous stores. Following a resident-intruder stress, during which stress hormones mobilize glucose from hepatic glycogen stores, KO mice showed a lower hyperglycemic level despite higher plasma cortisol levels when compared to WT mice. The lower hepatic glycogen levels observed in GCLM-KO mice could explain the impaired glycogen mobilization following induced hypoglycemia. Altogether, our results indicate that reduced liver glycogen availability, as observed in GCLM-KO mice, could be at the origin of their lower basal and challenged glycemia. Further studies will be necessary to understand how a GSH deficit, typically observed in GCLM-KO mice, leads to a deficit in liver glycogen storage.

  14. Glutamate Cysteine Ligase—Modulatory Subunit Knockout Mouse Shows Normal Insulin Sensitivity but Reduced Liver Glycogen Storage

    KAUST Repository

    Lavoie, Suzie; Steullet, Pascal; Kulak, Anita; Preitner, Frederic; Do, Kim Q.; Magistretti, Pierre J.

    2016-01-01

    Glutathione (GSH) deficits have been observed in several mental or degenerative illness, and so has the metabolic syndrome. The impact of a decreased glucose metabolism on the GSH system is well-known, but the effect of decreased GSH levels on the energy metabolism is unclear. The aim of the present study was to investigate the sensitivity to insulin in the mouse knockout (KO) for the modulatory subunit of the glutamate cysteine ligase (GCLM), the rate-limiting enzyme of GSH synthesis. Compared to wildtype (WT) mice, GCLM-KO mice presented with reduced basal plasma glucose and insulin levels. During an insulin tolerance test, GCLM-KO mice showed a normal fall in glycemia, indicating normal insulin secretion. However, during the recovery phase, plasma glucose levels remained lower for longer in KO mice despite normal plasma glucagon levels. This is consistent with a normal counterregulatory hormonal response but impaired mobilization of glucose from endogenous stores. Following a resident-intruder stress, during which stress hormones mobilize glucose from hepatic glycogen stores, KO mice showed a lower hyperglycemic level despite higher plasma cortisol levels when compared to WT mice. The lower hepatic glycogen levels observed in GCLM-KO mice could explain the impaired glycogen mobilization following induced hypoglycemia. Altogether, our results indicate that reduced liver glycogen availability, as observed in GCLM-KO mice, could be at the origin of their lower basal and challenged glycemia. Further studies will be necessary to understand how a GSH deficit, typically observed in GCLM-KO mice, leads to a deficit in liver glycogen storage.

  15. Metabolism, genomics, and DNA repair in the mouse aging liver

    DEFF Research Database (Denmark)

    Lebel, Michel; de Souza-Pinto, Nadja C; Bohr, Vilhelm A

    2011-01-01

    hepatic metabolic and detoxification activities, with implications for systemic aging and age-related disease. It has become clear, using rodent models as biological tools, that genetic instability in the form of gross DNA rearrangements or point mutations accumulate in the liver with age. DNA lesions......The liver plays a pivotal role in the metabolism of nutrients, drugs, hormones, and metabolic waste products, thereby maintaining body homeostasis. The liver undergoes substantial changes in structure and function within old age. Such changes are associated with significant impairment of many......, such as oxidized bases or persistent breaks, increase with age and correlate well with the presence of senescent hepatocytes. The level of DNA damage and/or mutation can be affected by changes in carcinogen activation, decreased ability to repair DNA, or a combination of these factors. This paper covers some...

  16. The acute effects of ethanol on acetanilide disposition in normal subjects, and in patients with liver disease.

    Science.gov (United States)

    McKay, J; Rawlings, M D; Cobden, I; James, O F

    1982-10-01

    1 The effects of single doses (25 g and 50 g) oral ethanol on the disposition of acetanilide (50 mg/kg metabolic active mass) has been studied in normal subjects, and in patients with chronic non-alcoholic liver disease. 2 In normal subjects, ethanol produced a dose-dependent increase in acetanilide half-life, and a decrease in acetenilide clearance. There was a significant correlation (rs = 0.71, P less than 0.01) between the 90 min blood ethanol concentration and the reduction in acetanilide clearance. 3 In patients with liver disease, ethanol produced a similar proportional change in acetanilide half-life and clearance, but these were less consistent. Moreover, liver disease itself was associated with an increase in acetenilide half-life, and a reduction in clearance. 4 It is concluded that single oral doses of ethanol, comparable to those consumed during social drinking, may inhibit some forms of microsomal oxidation and thus have important clinical implications.

  17. Biosynthesis of intestinal microvillar proteins. Processing of aminopeptidase N by microsomal membranes

    DEFF Research Database (Denmark)

    Danielsen, E M; Norén, Ove; Sjöström, H

    1983-01-01

    -bound rather than a soluble form, indicating that synthesis of the enzyme takes place on ribosomes attached to the rough endoplasmic reticulum. The microsomal fractions process the Mr-115 000 polypeptide, which is the primary translation product of aminopeptidase N, to a polypeptide of Mr 140 000...

  18. Mesenchymal stem cells improve mouse non-heart-beating liver graft survival by inhibiting Kupffer cell apoptosis via TLR4-ERK1/2-Fas/FasL-caspase3 pathway regulation

    Directory of Open Access Journals (Sweden)

    Yang Tian

    2016-10-01

    Full Text Available Abstract Background Liver transplantation is the optimal treatment option for end-stage liver disease, but organ shortages dramatically restrict its application. Donation after cardiac death (DCD is an alternative approach that may expand the donor pool, but it faces challenges such as graft dysfunction, early graft loss, and cholangiopathy. Moreover, DCD liver grafts are no longer eligible for transplantation after their warm ischaemic time exceeds 30 min. Mesenchymal stem cells (MSCs have been proposed as a promising therapy for treatment of certain liver diseases, but the role of MSCs in DCD liver graft function remains elusive. Methods In this study, we established an arterialized mouse non-heart-beating (NHB liver transplantation model, and compared survival rates, cytokine and chemokine expression, histology, and the results of in vitro co-culture experiments in animals with or without MSC infusion. Results MSCs markedly ameliorated NHB liver graft injury and improved survival post-transplantation. Additionally, MSCs suppressed Kupffer cell apoptosis, Th1/Th17 immune responses, chemokine expression, and inflammatory cell infiltration. In vitro, PGE2 secreted by MSCs inhibited Kupffer cell apoptosis via TLR4-ERK1/2-caspase3 pathway regulation. Conclusion Our study uncovers a protective role for MSCs and elucidates the underlying immunomodulatory mechanism in an NHB liver transplantation model. Our results suggest that MSCs are uniquely positioned for use in future clinical studies owing to their ability to protect DCD liver grafts, particularly in patients for whom DCD organs are not an option according to current criteria.

  19. Comparative Effects of Phosphoenolpyruvate, a Glycolytic Intermediate, as an Organ Preservation Agent with Glucose and N-Acetylcysteine against Organ Damage during Cold Storage of Mouse Liver and Kidney

    OpenAIRE

    Ishitsuka, Yoichi; Fukumoto, Yusuke; Kondo, Yuki; Irikura, Mitsuru; Kadowaki, Daisuke; Narita, Yuki; Hirata, Sumio; Moriuchi, Hiroshi; Maruyama, Toru; Hamasaki, Naotaka; Irie, Tetsumi

    2013-01-01

    We evaluated the usefulness of phosphoenolpyruvate (PEP), a glycolytic intermediate with antioxidative and energy supplementation potentials, as an organ preservation agent. Using ex vivo mouse liver and kidney of a static cold storage model, we compared the effects of PEP against organ damage and oxidative stress during cold preservation with those of glucose or N-acetylcysteine (NAC). Lactate dehydrogenase (LDH) leakage, histological changes, and oxidative stress parameters (measured as thi...

  20. Nicotine affects hydrogen sulfide concentrations in mouse kidney and heart but not in brain and liver tissues.

    Science.gov (United States)

    Wiliński, Jerzy; Wiliński, Bogdan; Somogyi, Eugeniusz; Piotrowska, Joanna; Kameczura, Tomasz; Zygmunt, Małgorzata

    2017-01-01

    Nicotine, a potent parasympathomimetic alkaloid with stimulant effects, is contributing to addictive properties of tobacco smoking and is though used in the smoking cessation therapy. Hydrogen sulfide (H2S) is involved in physiology and pathophysiology of various systems in mammals. The interactions between nicotine and H2S are not fully recognized. The aim of the study is to assess the influence of nicotine on the H2S tissue concentrations in different mouse organs. Adult CBA male mice were administered intraperitoneally 1.5 mg/kg b.w. per day of nicotine (group D1, n = 10) or 3 mg/ kg b.w. per day of nicotine (group D2, n = 10). The control group (n = 10) received physiological saline. The measurements of the free and acid-labile H2S tissue concentrations were performed with the Siegel spectrophotometric modi ed method. ere was a significant increase in H2S concentrations in both nicotine doses groups in the kidney (D1 by 54.2%, D2 by 40.0%). In the heart the higher nicotine dose caused a marked decrease in H2S tissue level (by 65.4%), while the lower dose did not affect H2S content. Nicotine administration had no effect on H2S concentrations in the brain and liver. In conclusion, nicotine affects H2S tissue concentrations in kidney and heart but not in the liver and brain tissues.

  1. Distribution of trans-resveratrol and its metabolites after acute or sustained administration in mouse heart, brain, and liver.

    Science.gov (United States)

    Menet, Marie-Claude; Baron, Stephanie; Taghi, Meryam; Diestra, Remi; Dargère, Delphine; Laprévote, Olivier; Nivet-Antoine, Valérie; Beaudeux, Jean-Louis; Bédarida, Tatiana; Cottart, Charles-Henry

    2017-08-01

    Trans-resveratrol is widely studied for its potentially beneficial effects on numerous disorders. It is rapidly metabolized and its metabolites can exhibit biological activity. The present study aimed to investigate whether acute or sustained trans-resveratrol administration impacted on the distribution of trans-resveratrol and its metabolites in brain, heart, and liver. We used ultra-HPLC quadrupole-TOF (UHPLC-Q-TOF) in a full-scan mode to identify and assess large numbers of resveratrol metabolites. For acute intake, mice were overfed with a single dose of trans-resveratrol (150 mg/kg) and organs were collected after 30 and 60 min. For sustained intake, trans-resveratrol was given in the chow (0.04% w/w corresponding to 40 mg/kg/day), and plasma and the organs were collected after 3 months of this resveratrol diet. We found that trans-resveratrol-3-O-glucuronide and resveratrol-3-sulfate were the main metabolites found after acute intake, and free trans-resveratrol (in the brain and heart) and dihydroresveratrol derivatives were found after sustained administration CONCLUSIONS: Our results show notable differences between acute and sustained administration of trans-resveratrol and distribution of trans-resveratrol and its metabolites in mouse heart, brain, and liver. The results suggest a strategy for development of galenic forms of resveratrol. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Hepatoprotective effect of kaempferol against alcoholic liver injury in mice.

    Science.gov (United States)

    Wang, Meng; Sun, Jianguo; Jiang, Zhihui; Xie, Wenyan; Zhang, Xiaoying

    2015-01-01

    Kaempferol is a biologically active component present in various plants. The hepatoprotective effect of kaempferol in drug-induced liver injury has been proven, while its effect against alcoholic liver injury (ALI) remains unclear. Hence, the present study aimed to evaluate the effect of kaempferol against ALI in mice. The experimental ALI mice model was developed and the mice were treated with different doses of kaempferol for 4 weeks. The liver functions were observed by monitoring the following parameters: Aspartate aminotransferase (AST/GOT) and alanine aminotransferase (ALT/GPT) levels in serum; histopathological studies of liver tissue; oxidative stress by hydrogen peroxide (H2O2), superoxide dismutase (SOD) and glutathione (GSH); the lipid peroxidation status by malondialdehyde (MDA) and lipid accumulation by triglyceride (TG) level in serum; and the expression levels and activities of a key microsomal enzyme cytochrome 2E1 (CYP2E1), by both in vitro and in vivo methods. The ALI mice (untreated) showed clear symptoms of liver injury, such as significantly increased levels of oxidative stress, lipid peroxidation and excessive CYP2E1 expression and activity. The mice treated with different kaempferol dosages exhibited a significant decrease in the oxidative stress as well as lipid peroxidation, and increased anti-oxidative defense activity. The kaempferol treatment has significantly reduced the expression level and activity of hepatic CYP2E1, thus indicating that kaempferol could down regulate CYP2E1. These findings show the hepatoprotective properties of kaempferol against alcohol-induced liver injury by attenuating the activity and expression of CYP2E1 and by enhancing the protective role of anti-oxidative defense system.

  3. Proadifen-sensitive high affinity binding of 3H-alaproclate to liver membranes

    International Nuclear Information System (INIS)

    Ross, S.B.

    1987-01-01

    3 H-alaproclate, a selective 5 h ydroxytryptamine uptake inhibitor, was found to bind to microsomal membranes from the rat liver with high affinity (K D -=3 nM) and large capacity (B max about 2 nmol/g liver). This binding was stereoselective since S-( - )-alaproclate was 30 times more potent than the R-( + )-enantiomer to displace the 3 H-labelled racemate. Proadifen (SKF 525A), an inhibitor of cytochrome P-450, displaced the 3 H-alaproclate binding with the same, high affinity (K i =3 nM) as alaproclate itself. Repeated treatment with phenobarbital sodium (5x75 mg/kg intraperitoneally) increased the number of alaproclate binding sites 7-8 times without changing the affinity. However, most of the phenobarbital induced 3 H-alaproclate binding was not displaceable by proadifen, showing the presence of at least two different high affinity binding sites. The possible involvement of cytochrome P-450 in the alaproclate binding is discussed. (author)

  4. Role of certain plant natural products or gamma radiation in the control of mutagenic activity of some heterocyclic amines

    International Nuclear Information System (INIS)

    Abu Ghadeer, A.R.M.; El-Sedeek, A.B.A.; Salem, A.M.; Abu Zaid, M.M.

    1999-01-01

    The present study was designed to use ames test to evaluate the antimutagenic effect of some natural products on the lever microsomes extracted from rats and incubated with some chemical mutagens (heterocyclic compounds). Male swiss albino rats (120-140 g) were used as the source of liver microsomes. Three natural products (Nigella extract, garlic powder and sesame oil) were used to evaluate their antimutagenic activities on six heterocyclic amines. All the tested natural products exhibited their antimutagenic activities when added to the investigated heterocyclic compounds and the most effective product was nigella sativa. another group of rats was exposed to gamma-radiation (6.5 Gy) for testing the validity of ames test in quantitating mutagenicity using liver microsomes of irradiated rats. Liver microsomes from irradiated rats showed to lose ability for metabolic activation needed for heterocyclic amines to exert their mutagenic effect on salmonella typhimurium

  5. Characterisation of the cytochrome P450 enzymes involved in the in vitro metabolism of granisetron.

    OpenAIRE

    Bloomer, J C; Baldwin, S J; Smith, G J; Ayrton, A D; Clarke, S E; Chenery, R J

    1994-01-01

    1. The metabolism of granisetron was investigated in human liver microsomes to identify the specific forms of cytochrome P450 responsible. 2. 7-hydroxy and 9'-desmethyl granisetron were identified as the major products of metabolism following incubation of granisetron with human liver microsomes. At low, clinically relevant, concentrations of granisetron the 7-hydroxy metabolite predominated. Rates of granisetron 7-hydroxylation varied over 100-fold in the human livers investigated. 3. Enzyme...

  6. Subcellular distribution of curium in beagle liver

    International Nuclear Information System (INIS)

    Bruenger, F.W.; Grube, B.J.; Atherton, D.R.; Taylor, G.N.; Stevens, W.

    1976-01-01

    The subcellular distribution of curium ( 243 244 Cm) was studied in canine liver from 2 hr to 47 days after injection of 3 μCi 243 244 Cm/kg of body weight. The pattern of distribution for Cm was similar to other trivalent actinide elements studied previously (Am, Cf). Initially (2 hr), most of the nuclide was found in the cytosol and at least 90 percent was protein bound. About 70 percent of the Cm was bound to ferritin, approximately 5 percent was associated with a protein of MW approximately 200,000, and approximately 25 percent was found in the low-molecular-weight region (approximately 5000). The decrease in the Cm content of cytosol, nuclei, and microsomes coincided with an increase in the amount associated with mitochondria and lysosomes. The concentration of the Cm in the mitochondrial fraction was higher than it was in the lysosomal fraction at each time studied. In the mitochondrial fraction approximately 30 percent of the Cm was bound to membranous or granular material, and 70 percent was found in the soluble fraction. The Cm concentration initially associated with cell nuclei was high but had diminished to 20 percent of the 2 hr concentration by 20 days post injection (PI). The subcellular distribution of Cm in the liver of a dog which had received the same dose and was terminated because of severe liver damage was studied at 384 days PI. The liver weighed 130 g and contained approximately 30 percent of the injected Cm. In contrast, a normal liver weighs 280 g and at 2 hr PI contains approximately 40 percent of the injected dose. The subcellular distribution of Cm in this severely damaged liver differed from the pattern observed at earlier times after injection. The relative concentration of Cm in the cytosol was doubled; it was higher in the nuclei-debris fraction; and it was lower in the mitochondrial and lysosomal fractions when compared to earlier times

  7. Metabolism of the insecticidally active GABA sub A receptor antagonist 4-sec-(3,4- sup 3 H sub 2 )butyl-1-(4-cyanophenyl)-2,6,7-trioxabicyclo(2. 2. 2)octane

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yanli; Palmer, C.J.; Toia, R.F.; Casida, J.E. (Univ. of California, Berkeley (USA))

    1990-03-01

    4-sec-(3,4-{sup 3}H{sub 2})Butyl-1-(4-cyanophenyl)-2,6,7-trioxabicyclo(2.2.2)octane (referred to as ({sup 3}H)COB) was examined as an example of a new class of insecticidally active compounds that block the {gamma}-aminobutyric acid gated chloride channel. Metabolites were identified by thin-layer cochromatography with standards from synthesis and by consideration of their hydrolytic and oxidative degradation products formed in situ on two-dimensional silica gel chromatoplates. Metabolism of ({sup 3}H)COB by mouse liver and housefly abdomen microsomes is dependent on fortification with NADPH. The O-methylene and sec-butyl sites are sensitive to oxidation. Each carbon of the sec-butyl group is individually functionalized with strong preference for the methylene site in the mouse but not the housefly microsomal system. O-Methylene hydroxylation initiates spontaneous cage opening to form an aldehyde that undergoes metabolic reduction, ultimately yielding the same cyanobenzoate ester of 2,2-bis-(hydroxymethyl)-3-methylpentan-1-ol formed by direct hydrolysis. Houseflies injected with ({sup 3}H)COB form many if not all of the same metabolites, with major products being the aforementioned cyanobenzoate, the orthoester oxidized at the sec-butyl methylene site, and polar conjugates.

  8. Metabolism of the insecticidally active GABAA receptor antagonist 4-sec-[3,4-3H2]butyl-1-(4-cyanophenyl)-2,6,7-trioxabicyclo[2.2.2]octane

    International Nuclear Information System (INIS)

    Deng, Yanli; Palmer, C.J.; Toia, R.F.; Casida, J.E.

    1990-01-01

    4-sec-[3,4- 3 H 2 ]Butyl-1-(4-cyanophenyl)-2,6,7-trioxabicyclo[2.2.2]octane (referred to as [ 3 H]COB) was examined as an example of a new class of insecticidally active compounds that block the γ-aminobutyric acid gated chloride channel. Metabolites were identified by thin-layer cochromatography with standards from synthesis and by consideration of their hydrolytic and oxidative degradation products formed in situ on two-dimensional silica gel chromatoplates. Metabolism of [ 3 H]COB by mouse liver and housefly abdomen microsomes is dependent on fortification with NADPH. The O-methylene and sec-butyl sites are sensitive to oxidation. Each carbon of the sec-butyl group is individually functionalized with strong preference for the methylene site in the mouse but not the housefly microsomal system. O-Methylene hydroxylation initiates spontaneous cage opening to form an aldehyde that undergoes metabolic reduction, ultimately yielding the same cyanobenzoate ester of 2,2-bis-(hydroxymethyl)-3-methylpentan-1-ol formed by direct hydrolysis. Houseflies injected with [ 3 H]COB form many if not all of the same metabolites, with major products being the aforementioned cyanobenzoate, the orthoester oxidized at the sec-butyl methylene site, and polar conjugates

  9. Ultrastructural study of Rift Valley fever virus in the mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Christopher; Steele, Keith E.; Honko, Anna; Shamblin, Joshua; Hensley, Lisa E. [United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD (United States); Smith, Darci R., E-mail: darci.smith1@us.army.mil [United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD (United States)

    2012-09-15

    Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed in the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV-host interactions and further characterize the mouse model of RVF.

  10. Ultrastructural study of Rift Valley fever virus in the mouse model

    International Nuclear Information System (INIS)

    Reed, Christopher; Steele, Keith E.; Honko, Anna; Shamblin, Joshua; Hensley, Lisa E.; Smith, Darci R.

    2012-01-01

    Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed in the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV–host interactions and further characterize the mouse model of RVF.

  11. Metabolites of the 1',2'-dimethylheptyl analogue of delta-8-tetrahydrocannabinol in the mouse and their identification by gas chromatography/mass spectrometry.

    Science.gov (United States)

    Harvey, D J; Brown, N K

    1990-10-01

    Metabolism of the 1,2-dimethylheptyl analogue of delta-8-tetrahydrocannabinol (delta-8-DMHP) was studied in vitro using mouse hepatic microsomes and in vivo in mouse liver. Metabolites were extracted with ethyl acetate, concentrated by chromatography on Sephadex LH-20 and examined by low-resolution mass spectrometry as trimethylsilyl (TMS), (2H9)TMS and methyl ester/TMS derivatives. Reduction of metabolites with lithium aluminium deuteride also provided structural information. The electron-impact-induced mass spectrum of the TMS derivative of DMHP differed from that of its unbranched side-chain analogues in that prominent ions were produced by fragmentation of the side-chain at the expense of the retro-Diels-Alder fragmentation that was prominent in the spectra of the latter compounds. This, however, was found to reduce the relative abundance of ions diagnostic of side-chain hydroxy substitution in the spectra of the metabolites. In vitro, the only significant metabolite was 11-hydroxy-delta-8-DMHP. This is in contrast with metabolism of the corresponding delta-8-tetrahydrocannabinol (delta-8-THC, n-C5-side-chain) where a number of other monohydroxy metabolites are produced. Fifteen metabolites were found in vivo, of which nine were identified. Mass spectral information was not sufficient to determine the position of one of the hydroxy groups in the other six metabolites. The major site of hydroxylation was at C-11 and the resulting hydroxy metabolite was oxidized to delta-8-DMHP-11-oic acid. In this respect metabolism paralleled that of delta-8-THC. Dihydroxylation of the double bond also occurred, presumably via the epoxide.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Differential metabolism of 4-hydroxynonenal in liver, lung and brain of mice and rats

    International Nuclear Information System (INIS)

    Zheng, Ruijin; Dragomir, Ana-Cristina; Mishin, Vladimir; Richardson, Jason R.; Heck, Diane E.; Laskin, Debra L.; Laskin, Jeffrey D.

    2014-01-01

    The lipid peroxidation end-product 4-hydroxynonenal (4-HNE) is generated in tissues during oxidative stress. As a reactive aldehyde, it forms Michael adducts with nucleophiles, a process that disrupts cellular functioning. Liver, lung and brain are highly sensitive to xenobiotic-induced oxidative stress and readily generate 4-HNE. In the present studies, we compared 4-HNE metabolism in these tissues, a process that protects against tissue injury. 4-HNE was degraded slowly in total homogenates and S9 fractions of mouse liver, lung and brain. In liver, but not lung or brain, NAD(P)+ and NAD(P)H markedly stimulated 4-HNE metabolism. Similar results were observed in rat S9 fractions from these tissues. In liver, lung and brain S9 fractions, 4-HNE formed protein adducts. When NADH was used to stimulate 4-HNE metabolism, the formation of protein adducts was suppressed in liver, but not lung or brain. In both mouse and rat tissues, 4-HNE was also metabolized by glutathione S-transferases. The greatest activity was noted in livers of mice and in lungs of rats; relatively low glutathione S-transferase activity was detected in brain. In mouse hepatocytes, 4-HNE was rapidly taken up and metabolized. Simultaneously, 4-HNE-protein adducts were formed, suggesting that 4-HNE metabolism in intact cells does not prevent protein modifications. These data demonstrate that, in contrast to liver, lung and brain have a limited capacity to metabolize 4-HNE. The persistence of 4-HNE in these tissues may increase the likelihood of tissue injury during oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a highly reactive aldehyde. • Rodent liver, but not lung or brain, is efficient in degrading 4-hydroxynonenal. • 4-hydroxynonenal persists in tissues with low metabolism, causing tissue damage

  13. Differential metabolism of 4-hydroxynonenal in liver, lung and brain of mice and rats

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Ruijin; Dragomir, Ana-Cristina; Mishin, Vladimir [Pharmacology and Toxicology, Rutgers University-Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Richardson, Jason R. [Environmental and Occupational Medicine, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ (United States); Heck, Diane E. [Environmental Science, School of Health Sciences and Practice, New York Medical College, Valhalla, NY (United States); Laskin, Debra L. [Pharmacology and Toxicology, Rutgers University-Ernest Mario School of Pharmacy, Piscataway, NJ (United States); Laskin, Jeffrey D., E-mail: jlaskin@eohsi.rutgers.edu [Environmental and Occupational Medicine, Rutgers University-Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2014-08-15

    The lipid peroxidation end-product 4-hydroxynonenal (4-HNE) is generated in tissues during oxidative stress. As a reactive aldehyde, it forms Michael adducts with nucleophiles, a process that disrupts cellular functioning. Liver, lung and brain are highly sensitive to xenobiotic-induced oxidative stress and readily generate 4-HNE. In the present studies, we compared 4-HNE metabolism in these tissues, a process that protects against tissue injury. 4-HNE was degraded slowly in total homogenates and S9 fractions of mouse liver, lung and brain. In liver, but not lung or brain, NAD(P)+ and NAD(P)H markedly stimulated 4-HNE metabolism. Similar results were observed in rat S9 fractions from these tissues. In liver, lung and brain S9 fractions, 4-HNE formed protein adducts. When NADH was used to stimulate 4-HNE metabolism, the formation of protein adducts was suppressed in liver, but not lung or brain. In both mouse and rat tissues, 4-HNE was also metabolized by glutathione S-transferases. The greatest activity was noted in livers of mice and in lungs of rats; relatively low glutathione S-transferase activity was detected in brain. In mouse hepatocytes, 4-HNE was rapidly taken up and metabolized. Simultaneously, 4-HNE-protein adducts were formed, suggesting that 4-HNE metabolism in intact cells does not prevent protein modifications. These data demonstrate that, in contrast to liver, lung and brain have a limited capacity to metabolize 4-HNE. The persistence of 4-HNE in these tissues may increase the likelihood of tissue injury during oxidative stress. - Highlights: • Lipid peroxidation generates 4-hydroxynonenal, a highly reactive aldehyde. • Rodent liver, but not lung or brain, is efficient in degrading 4-hydroxynonenal. • 4-hydroxynonenal persists in tissues with low metabolism, causing tissue damage.

  14. Liver-derived systemic factors drive β-cell hyperplasia in insulin resistant states

    Energy Technology Data Exchange (ETDEWEB)

    El Ouaamari, Abdelfattah; Kawamori, Dan; Dirice, Ercument; Liew, Chong Wee; Shadrach, Jennifer L.; Hu, Jiang; Katsuta, Hitoshi; Hollister-Lock, Jennifer; Qian, Weijun; Wagers, Amy J.; Kulkarni, Rohit N.

    2013-02-21

    Integrative organ cross-talk regulates key aspects of energy homeostasis and its dysregulation may underlie metabolic disorders such as obesity and diabetes. To test the hypothesis that cross-talk between the liver and pancreatic islets modulates β-cell growth in response to insulin resistance, we used the Liver-specific Insulin Receptor Knockout (LIRKO) mouse, a unique model that exhibits dramatic islet hyperplasia. Using complementary in vivo parabiosis and transplantation assays, and in vitro islet culture approaches, we demonstrate that humoral, non-neural, non-cell autonomous factor(s) induce β-cell proliferation in LIRKO mice. Furthermore, we report that a hepatocyte-derived factor(s) stimulates mouse and human β-cell proliferation in ex vivo assays, independent of ambient glucose and insulin levels. These data implicate the liver as a critical source of β-cell growth factors in insulin resistant states.

  15. Modeling toxicodynamic effects of trichloroethylene on liver in mouse model of autoimmune hepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Kathleen M., E-mail: gilbertkathleenm@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States); Reisfeld, Brad, E-mail: brad.reisfeld@colostate.edu [Colorado State University, Fort Collins, CO (United States); Zurlinden, Todd J., E-mail: tjzurlin@rams.colostate.edu [Colorado State University, Fort Collins, CO (United States); Kreps, Meagan N., E-mail: MNKreps@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States); Erickson, Stephen W., E-mail: serickson@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States); Blossom, Sarah J., E-mail: blossomsarah@uams.edu [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital Research Institute, Little Rock, AR 72202 (United States)

    2014-09-15

    Chronic exposure to industrial solvent and water pollutant trichloroethylene (TCE) in female MRL +/+ mice generates disease similar to human autoimmune hepatitis. The current study was initiated to investigate why TCE-induced autoimmunity targeted the liver. Compared to other tissues the liver has an unusually robust capacity for repair and regeneration. This investigation examined both time-dependent and dose-dependent effects of TCE on hepatoprotective and pro-inflammatory events in liver and macrophages from female MRL +/+ mice. After a 12-week exposure to TCE in drinking water a dose-dependent decrease in macrophage production of IL-6 at both the transcriptional and protein level was observed. A longitudinal study similarly showed that TCE inhibited macrophage IL-6 production. In terms of the liver, TCE had little effect on expression of pro-inflammatory genes (Tnfa, Saa2 or Cscl1) until the end of the 40-week exposure. Instead, TCE suppressed hepatic expression of genes involved in IL-6 signaling (Il6r, gp130, and Egr1). Linear regression analysis confirmed liver histopathology in the TCE-treated mice correlated with decreased expression of Il6r. A toxicodynamic model was developed to estimate the effects of TCE on IL-6 signaling and liver pathology under different levels of exposure and rates of repair. This study underlined the importance of longitudinal studies in mechanistic evaluations of immuntoxicants. It showed that later-occurring liver pathology caused by TCE was associated with early suppression of hepatoprotection rather than an increase in conventional pro-inflammatory events. This information was used to create a novel toxicodynamic model of IL-6-mediated TCE-induced liver inflammation. - Highlights: • We developed a toxicodynamic model to study effects of trichloroethylene on liver. • We examined protective as well as pro-inflammatory events in the liver. • Trichloroethylene inhibits IL-6 production by macrophages. • Trichloroethylene

  16. Modeling toxicodynamic effects of trichloroethylene on liver in mouse model of autoimmune hepatitis

    International Nuclear Information System (INIS)

    Gilbert, Kathleen M.; Reisfeld, Brad; Zurlinden, Todd J.; Kreps, Meagan N.; Erickson, Stephen W.; Blossom, Sarah J.

    2014-01-01

    Chronic exposure to industrial solvent and water pollutant trichloroethylene (TCE) in female MRL +/+ mice generates disease similar to human autoimmune hepatitis. The current study was initiated to investigate why TCE-induced autoimmunity targeted the liver. Compared to other tissues the liver has an unusually robust capacity for repair and regeneration. This investigation examined both time-dependent and dose-dependent effects of TCE on hepatoprotective and pro-inflammatory events in liver and macrophages from female MRL +/+ mice. After a 12-week exposure to TCE in drinking water a dose-dependent decrease in macrophage production of IL-6 at both the transcriptional and protein level was observed. A longitudinal study similarly showed that TCE inhibited macrophage IL-6 production. In terms of the liver, TCE had little effect on expression of pro-inflammatory genes (Tnfa, Saa2 or Cscl1) until the end of the 40-week exposure. Instead, TCE suppressed hepatic expression of genes involved in IL-6 signaling (Il6r, gp130, and Egr1). Linear regression analysis confirmed liver histopathology in the TCE-treated mice correlated with decreased expression of Il6r. A toxicodynamic model was developed to estimate the effects of TCE on IL-6 signaling and liver pathology under different levels of exposure and rates of repair. This study underlined the importance of longitudinal studies in mechanistic evaluations of immuntoxicants. It showed that later-occurring liver pathology caused by TCE was associated with early suppression of hepatoprotection rather than an increase in conventional pro-inflammatory events. This information was used to create a novel toxicodynamic model of IL-6-mediated TCE-induced liver inflammation. - Highlights: • We developed a toxicodynamic model to study effects of trichloroethylene on liver. • We examined protective as well as pro-inflammatory events in the liver. • Trichloroethylene inhibits IL-6 production by macrophages. • Trichloroethylene

  17. Activation of cellular immunity and marked inhibition of liver cancer in a mouse model following gene therapy and tumor expression of GM-SCF, IL-21, and Rae-1.

    Science.gov (United States)

    Cheng, Mingrong; Zhi, Kangkang; Gao, Xiaoyan; He, Bing; Li, Yingchun; Han, Jiang; Zhang, Zhiping; Wu, Yan

    2013-12-18

    Cancer is both a systemic and a genetic disease. The pathogenesis of cancer might be related to dampened immunity. Host immunity recognizes nascent malignant cells - a process referred to as immune surveillance. Augmenting immune surveillance and suppressing immune escape are crucial in tumor immunotherapy. A recombinant plasmid capable of co-expressing granulocyte-macrophage colony- stimulating factor (GM-SCF), interleukin-21 (IL-21), and retinoic acid early transcription factor-1 (Rae-1) was constructed, and its effects determined in a mouse model of subcutaneous liver cancer. Serum specimens were assayed for IL-2 and INF-γ by ELISA. Liver cancer specimens were isolated for Rae-1 expression by RT-PCR and Western blot, and splenocytes were analyzed by flow cytometry. The recombinant plasmid inhibited the growth of liver cancer and prolonged survival of tumor-loaded mice. Activation of host immunity might have contributed to this effect by promoting increased numbers and cytotoxicity of natural killer (NK) cells and cytotoxic T lymphocytes (CTL) following expression of GM-SCF, IL-21, and Rae-1. By contrast, the frequency of regulatory T cells was decreased, Consequently, activated CTL and NK cells enhanced their secretion of INF-γ, which promoted cytotoxicity of NK cells and CTL. Moreover, active CTL showed dramatic secretion of IL-2, which stimulates CTL. The recombinant expression plasmid also augmented Rae-1 expression by liver cancer cells. Rae-1 receptor expressing CTL and NK cells removed liver cancer. The recombinant expression plasmid inhibited liver cancer by a mechanism that involved activation of cell-mediated immunity and Rae-1 in liver cancer.

  18. Circulating extracellular vesicles with specific proteome and liver microRNAs are potential biomarkers for liver injury in experimental fatty liver disease.

    Directory of Open Access Journals (Sweden)

    Davide Povero

    Full Text Available Nonalcoholic fatty liver disease (NAFLD is the most common chronic liver disease in both adult and children. Currently there are no reliable methods to determine disease severity, monitor disease progression, or efficacy of therapy, other than an invasive liver biopsy.Choline Deficient L-Amino Acid (CDAA and high fat diets were used as physiologically relevant mouse models of NAFLD. Circulating extracellular vesicles were isolated, fully characterized by proteomics and molecular analyses and compared to control groups. Liver-related microRNAs were isolated from purified extracellular vesicles and liver specimens.We observed statistically significant differences in the level of extracellular vesicles (EVs in liver and blood between two control groups and NAFLD animals. Time-course studies showed that EV levels increase early during disease development and reflect changes in liver histolopathology. EV levels correlated with hepatocyte cell death (r2 = 0.64, p<0.05, fibrosis (r2 = 0.66, p<0.05 and pathological angiogenesis (r2 = 0.71, p<0.05. Extensive characterization of blood EVs identified both microparticles (MPs and exosomes (EXO present in blood of NAFLD animals. Proteomic analysis of blood EVs detected various differentially expressed proteins in NAFLD versus control animals. Moreover, unsupervised hierarchical clustering identified a signature that allowed for discrimination between NAFLD and controls. Finally, the liver appears to be an important source of circulating EVs in NAFLD animals as evidenced by the enrichment in blood with miR-122 and 192--two microRNAs previously described in chronic liver diseases, coupled with a corresponding decrease in expression of these microRNAs in the liver.These findings suggest a potential for using specific circulating EVs as sensitive and specific biomarkers for the noninvasive diagnosis and monitoring of NAFLD.

  19. Proadifen-sensitive high affinity binding of /sup 3/H-alaproclate to liver membranes

    Energy Technology Data Exchange (ETDEWEB)

    Ross, S.B.

    1987-01-01

    /sup 3/H-alaproclate, a selective 5/sub h/ydroxytryptamine uptake inhibitor, was found to bind to microsomal membranes from the rat liver with high affinity (K/sub D/-=3 nM) and large capacity (B/sub max/ about 2 nmol/g liver). This binding was stereoselective since S-( - )-alaproclate was 30 times more potent than the R-( + )-enantiomer to displace the /sup 3/H-labelled racemate. Proadifen (SKF 525A), an inhibitor of cytochrome P-450, displaced the /sup 3/H-alaproclate binding with the same, high affinity (K/sub i/=3 nM) as alaproclate itself. Repeated treatment with phenobarbital sodium (5x75 mg/kg intraperitoneally) increased the number of alaproclate binding sites 7-8 times without changing the affinity. However, most of the phenobarbital induced /sup 3/H-alaproclate binding was not displaceable by proadifen, showing the presence of at least two different high affinity binding sites. The possible involvement of cytochrome P-450 in the alaproclate binding is discussed.

  20. Targeting the vascular and perivascular niches as a regenerative therapy for lung and liver fibrosis.

    Science.gov (United States)

    Cao, Zhongwei; Ye, Tinghong; Sun, Yue; Ji, Gaili; Shido, Koji; Chen, Yutian; Luo, Lin; Na, Feifei; Li, Xiaoyan; Huang, Zhen; Ko, Jane L; Mittal, Vivek; Qiao, Lina; Chen, Chong; Martinez, Fernando J; Rafii, Shahin; Ding, Bi-Sen

    2017-08-30

    The regenerative capacity of lung and liver is sometimes impaired by chronic or overwhelming injury. Orthotopic transplantation of parenchymal stem cells to damaged organs might reinstate their self-repair ability. However, parenchymal cell engraftment is frequently hampered by the microenvironment in diseased recipient organs. We show that targeting both the vascular niche and perivascular fibroblasts establishes "hospitable soil" to foster the incorporation of "seed," in this case, the engraftment of parenchymal cells in injured organs. Specifically, ectopic induction of endothelial cell (EC)-expressed paracrine/angiocrine hepatocyte growth factor (HGF) and inhibition of perivascular NOX4 [NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidase 4] synergistically enabled reconstitution of mouse and human parenchymal cells in damaged organs. Reciprocally, genetic knockout of Hgf in mouse ECs ( Hgf iΔEC/iΔEC ) aberrantly up-regulated perivascular NOX4 during liver and lung regeneration. Dysregulated HGF and NOX4 pathways subverted the function of vascular and perivascular cells from an epithelially inductive niche to a microenvironment that inhibited parenchymal reconstitution. Perivascular NOX4 induction in Hgf iΔEC/iΔEC mice recapitulated the phenotype of human and mouse liver and lung fibrosis. Consequently, EC-directed HGF and NOX4 inhibitor GKT137831 stimulated regenerative integration of mouse and human parenchymal cells in chronically injured lung and liver. Our data suggest that targeting dysfunctional perivascular and vascular cells in diseased organs can bypass fibrosis and enable reparative cell engraftment to reinstate lung and liver regeneration. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.