L'exposition humaine aux contaminants environnementaux est inévitable du fait de leur présence dans l'eau, l'air et l'alimentation. La plupart d'entre eux sont reconnus comme étant mutagènes et/ou carcinogènes chez l'animal mais ils sont souvent seulement suspectés de l'être chez l'Homme. Le manque de connaissance vis-à-vis des substances chimiques a conduit l'UE à lancer le programme REACH avec l'objectif d'évaluer la toxicité d'environ 30 000 molécules. Cette évaluation nécessiterait l'utilisation de plus de 4 millions d'animaux et la pertinence controversée de ces modèles pourrait aboutir à des conclusions discutables. Les méthodes in vitro sont considérées comme une alternative potentielle à l'expérimentation animale. Néanmoins, le choix du modèle cellulaire et des conditions expérimentales restent à préciser. Les hépatocytes humains en culture primaire représentent le modèle le plus pertinent en toxicologie malgré de nombreuses contraintes (variabilité inter-individuelle, changements phénotypique précoces, obtention aléatoire). La lignée HepaRG constitue une alternative intéressante puisque ces cellules peuvent proliférer de manière illimitée et expriment les EMXs à des niveaux proches des hépatocytes humains. L'expression de ces enzymes restant stable pendant plusieurs semaines, ce modèle permet l'évaluation du risque lié à une exposition chronique aux contaminents environnementaux, essentielle en génotoxicité. Il reste cependant nécessaire de caractériser plus amplement cette lignée vis-à-vis des EMXs et de l'adapter aux tests de toxicologie actuels. Dans ces travaux, nous avons développé un test haut débit utilisant la quantification in situ des histones phosphorylées γH2AX avec l'objectif de pouvoir évaluer le risque génotoxique d'une exposition unique ou répétée aux contaminants environnementaux. Ce test a été validé avec succès par l'évaluation de la génotoxicité associée à une exposition de 1, 7 et 14 jours pour 10 polluants. Nous avons ensuite généré des lignées recombinantes biosenseurs, dérivées du modèle HepaRG et permettant d'identifier les xénobiotiques altérant l'expression transcriptionnelle des EMXs. Par transfection transitoire, nous avons dans un premier temps validé à l'aide d'inducteurs prototypiques et de nos 10 contaminants nos constructions contenant le gène rapporteur de la luciférase sous le contrôle des promoteurs de plusieurs EMXs. Ensuite, nous avons généré des lignées stables exprimant la GFP comme gène rapporteur et permettant une détection rapide des xénobiotiques capables d'induire l'expression des EMXs. Parmi les EMXs, le CYP2E1 joue un rôle important en santé humaine. En effet, cette enzyme induite dans certaines conditions physiopathologiques comme le diabète et l'obésité est responsable de l'activation de nombreux procarcinogènes et est à l'origine d'une production d'EROs. Les cellules HepaRG pourraient constituer un modèle pertinent pour l'étude du CYP2E1. Cependant, l'expression et l'activité de cette enzyme au sein de ce modèle nécessitent d'être mieux caractérisées en regard des données discordantes de la littérature. A l'aide de la chlorzoxazone, un marqueur spécifique de l'activité du CYP2E1, nous avons démontré l'influence du métabolisme de phase II sur l'activité apparente du CYP2E1. Nous proposons ici quelques recommandations afin de mieux quantifier l'activité du CYP2E1 sur les hépatocytes humains et sur le modèle HepaRG à l'aide la chlorzoxazone. / Human exposure to toxic chemicals is virtually unavoidable due to contamination of air, water and food. A number of environmental contaminants are recognized as mutagenic and/or carcinogenic in animal but they are often only suspected to have similar effects in Humans. The lack of knowledge on the effects of most industrial-made chemicals has led the EU to launch the REACH program with the aim of evaluating the toxicity of more than 30.000 molecules. Such evaluation would require the use of at least 4 millions of animals for an estimated cost of 2.8 billions €. While the relevance of these in vivo models remains controversial.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Made available in DSpace on 2016-08-10T10:39:12Z (GMT). No. of bitstreams: 1 JHENEFFER SONARA AGUIAR RAMOS.pdf: 3001795 bytes, checksum: 76b7e24451f0b40a66c4247eec7df460 (MD5) Previous issue date: 2016-03-14 / The Cytochrome P4502E1 (CYP2E1) gene encodes an enzyme which is the main constituent of microsomal ethanol oxidizing system. Genetic variation present in the CYP2E1 gene result in significant differences in enzyme activity, however the functional significance of these variations in the metabolism of ethanol remains controversial, since there is not yet a clear correlation with differences in catalytic activity of the enzyme. In this study, the variability of the promoter region of the CYP2E1 gene was analyzed in samples of alcoholics of a Psychosocial Attention Center (CAPS) in the state of Goiás, in the city of Goiânia and the results were compared with the data obtained by the 1000 Genomes project. We conducted a study of association between polymorphisms of the promoter region of the CYP2E1 and genotoxic damage in alcoholics, for this sequencing reaction and the comet assay were performed. In our analysis there was no correlation of data polymorphisms found with genotoxic damage. However, genotoxicity analysis of the groups showed greater genotoxic damage in the case group (alcoholic) compared to the control group (p<0,05). Considering all populations evaluated, 17 points of variation were found. These points of variation are arranged in 22 different haplotypes. A high linkage disequilibrium was observed between the variants at positions -1295 and -1055, in the case and control groups and the American, European and Asian populations. Considering the complex interaction between genetic and environmental factors in response of interindividual alcoholic beverages, it is desirable to conduct studies about this interaction in populations with different genetic characteristics. / O gene citocromo P4502E1 (CYP2E1) codifica uma enzima que é a principal constituinte do Sistema microssomal de oxidação do etanol. Variações genéticas presentes no gene CYP2E1 resultam em diferenças significativas na atividade enzimática, entretanto o significado funcional dessas variações no metabolismo do etanol permanece controverso, uma vez que ainda não existe uma correlação evidente com diferenças na atividade catalítica da enzima. No presente estudo, a variabilidade da região promotora do gene CYP2E1 foi analisada em amostras de alcoolistas de um Centro de Atenção Psicossocial (CAPS) do Estado de Goiás, da cidade de Goiânia e os resultados foram comparados com os dados obtidos pelo projeto 1000 Genomas. Foi realizado um estudo de associação entre polimorfismos da região promotora do CYP2E1 e o dano genotóxico em alcoolistas, para isso foram realizados a reação de sequenciamento e o ensaio cometa. Nas nossas análises não houve relação dos dados de polimorfismos encontrados com o dano genotóxico. Entretanto, a análise de genotoxidade dos grupos analisados mostrou maior dano genotóxico no grupo caso (alcoolistas) em relação ao grupo controle (p<0,05). Considerando todas as populações avaliadas, 17 pontos de variação foram encontrados. Estes pontos de variação estão arranjados em 22 haplótipos diferentes. Um elevado desequilíbrio de ligação foi observado entre as variantes nas posições -1295 e - 1055, nos grupos caso e controle e nas populações americana, europeia e asiática. Considerando a complexa interação entre fatores genéticos e ambientais na resposta interindividual ao uso de bebidas alcoólicas, é desejável a realização de estudos acerca dessa interação em populações com características genéticas distintas.

INTRODUCTION: The liver is the primary organ responsible for the removal of toxic substances from the body by means of a variety of metabolic pathways. One class of proteins responsible for much of the body’s xenobiotic drug and alcohol metabolism is the Cytochrome P450 family of proteins. One protein, Cytochrome P450 Class E Subclass 2 (Cyp2E1), has an integral role in alcohol metabolism by the liver. Cyp2E1 becomes fully activated after an organism has consumed excessive amounts of alcohol excessive alcohol and works with aldehyde dehydrogenase (ALDH) to metabolize ethanol to acetaldehyde. Another metabolic protein, C1q TNF Related Protein 3 (CTRP3), has been shown to effectively prevent alcoholic fatty liver disease (AFLD), specifically with long-term alcohol-induced lipid accumulation. METHODS: In this experiment, 12-week old male mice were fed a Lieber-Decarli alcohol diet (5% ETOH by volume) for 6-weeks. The food intake and body weight of the mice was recorded each day. The mice in the experiment included both wild type and transgenic CTRP3 overexpressing mice. At the end of the 6-week period the mice were euthanized, and the liver was carefully removed, flash-frozen, and prepared for immunoblot analysis of the proteins. RESULTS: Cyp2E1 levels increased significantly in response to ethanol consumption. Cyp2E1 levels were further elevated in ethanol-fed CTRP3 transgenic overexpressing mice. Cyp2E1 levels in CTRP3 transgenic mice were nearly twice that of wild type ethanol-fed mice. CONCLUSIONS: The results of the experiment show a significant increase in Cyp2E1 in mice which overexpress CTRP3. This upregulation of Cyp2E1 with CTRP3 overexpression could explain the mechanism for reduced hepatic lipid accumulation in ethanol-fed CTRP3 transgenic mice.

Obesity is linked to nonalcoholic steatohepatitis. Peroxisome proliferator-activated receptor-a (PPARa) regulates lipid metabolism. Cytochrome P-450 2A5 (CYP2A5) is a potential antioxidant and CYP2A5 induction by ethanol is CYP2E1 dependent. High-fat diet (HFD)-induced obesity and steatosis are more severe in CYP2A5 knockout (cyp2a5 -/- ) mice than in wild-type mice although PPARa is elevated in cyp2a5 -/- mice. To examine why the upregulated PPARa failed to prevent the enhanced steatosis in cyp2a5 -/- mice, we abrogate the upregulated PPARa in cyp2a5 -/- mice by cross-breeding cyp2a5 -/- mice with PPARa knockout (ppara-/- ) mice to create ppara-/- /cyp2a5 -/- mice. The ppara-/- /cyp2a5 -/- mice, ppara-/- mice, and cyp2a5 -/- mice were fed HFD to induce steatosis. After HFD feeding, more severe steatosis was developed in ppara-/- /cyp2a5 -/- mice than in ppara-/- mice and cyp2a5 -/- mice. The ppara-/- /cyp2a5 -/- mice and ppara-/- mice exhibited comparable and impaired lipid metabolism. Elevated serum alanine transaminase and liver interleukin-1β, liver inflammatory cell infiltration, and foci of hepatocellular ballooning were observed in ppara-/- /cyp2a5 -/- mice but not in ppara-/- mice and cyp2a5 -/- mice. In ppara-/- /cyp2a5 -/- mice, although redox-sensitive transcription factor nuclear factor erythroid 2-related factor 2 and its target antioxidant genes were upregulated as a compensation, thioredoxin was suppressed, and phosphorylation of JNK and formation of nitrotyrosine adduct were increased. Liver glutathione was decreased, and lipid peroxidation was increased. Interestingly, inflammation and fibrosis were all observed within the clusters of lipid droplets, and these lipid droplet clusters were all located inside the area with CYP2E1-positive staining. These results suggest that HFD-induced fibrosis in ppara-/- /cyp2a5 -/- mice is associated with steatosis, and CYP2A5 interacts with PPARa to participate in regulating steatohepatitis-associated fibrosis.

Muitos autores associam as doenças alcoólicas hepáticas às deficiências nutricionais. Por outro lado, trabalhos experimentais estabelecem que a hepatotoxidade alcoólica relaciona-se especialmente à geração de espécies reativas através do sistema microsomal que oxida etanol via citocromo 450, principalmente o CYP2E1. O CYP2E1 hepático tem a capacidade de ativar algumas drogas comumente utilizadas, como o acetaminofeno, em seus metabólitos mais tóxicos e promover carcinogênese. Além. disso, o metabolismo pelo CYP2E1 resulta num aumento na produção de espécies reativas, com diminuição nos sistemas de defesa antioxidantes, estabelecendo o estresse oxidativo. Como a expressão do CYP2E1 é muito influenciada por fatores nutricionais e hormonais, este trabalho descreve os efeitos do tratamento com etanol nos níveis de CYP2E1 e sua relação com alguns parâmetros pró- e antioxidantes, considerando três modelos experimentais diferentes. Ratos machos Sprague Dawley com cerca de três meses de idade receberam ad lib. ração Purina (Purina Ind., Brasil) e, separadamente, uma solução 25 % etanol-20%sacarose durante 1, 2, 3 ou 4 semanas. Os grupos controles foram isocaloricamente pareados aos animais que consumiram etanol, ou receberam quantidades de sacarose equivalentes às calorias recebidas com o consumo de etanol. 18 h antes do sacrifício os animais foram mantidos em abstinência alcoólica, recebendo água e ração ou apenas água ad lib. Os resultados indicam que o consumo de etanol pode ser associado à estabilização do CYP2E1. No entanto, nas nossas condições experimentais, a presença da isoforma não está associada ao estresse oxidativo. Esses resultados indicam que as deficiências nutricionais, especialmente o baixo consumo de carboidratos, são fundamentais na potenciação do estresse oxidativo induzido pelo etanol. / Many authors have attributed alcoholic liver disease to dietary deficiencies. On the other hand, experimental studies have established that alcohol hepatotoxicity is especially related to the generation of oxidant species through its microsomal metabolism via cytochrome P-450, mainly CYP2E1. Liver CYP2E1 has a high capacity to activate some commonly used drugs, such as acetaminophen, to their toxic metabolites, and to promote carcinogenesis. Moreover, metabolism by CYP2E1 results in a significant reactive oxygen species (ROS) release, accompanied by the defense systems decrease against oxidative stress. Since the expression of CYP2E1 is very much influenced by hormonal and nutritional factors, this study describes the effects of ethanol treatment on CYP2E 1 levels and their relationship with some pro and antioxidant parameters considering three experimental models. Male Sprague-Dawley rats were fed ad. lib. for 1, 2, 3 or 4 weeks a commercial diet (Purina Ind., Brazil) plus a 25% ethanol-20% sucrose solution. Control groups were isocalorically pair-feed to the leading ethanol-consuming animals, or received isocaloric amounts of sucrose for pairing only ethanol calories. Eighteen hours before sacrifice ethanol was withdrawal and animals had only free access to tap water or they were offered food and water ad. lib. Results have shown that ethanol administration was associated with CYP2E1 stabilization although under our experimental condition it was not associated with any oxidative stress. These findings indicate that dietary deficiencies, especially low carbohydrate intake are crucial in the potentiation of the ethanol-induced oxidative stress.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 200-205).

L'obésité et les maladies du foie associées (NAFLD) augmentent le risque et la sévérité de l’hépatotoxicité induite par certains xénobiotiques, mais les mécanismes impliqués sont encore mal compris. Pour l'éthanol et le paracétamol (APAP), le rôle du cytochrome P450 2E1 (CYP2E1) hépatique est suspecté car l'activité de cette enzyme est augmentée au cours de ces pathologies dysmétaboliques. Le 1er objectif de notre travail expérimental a été de mettre au point un modèle cellulaire de NAFLD caractérisé non seulement par l'accumulation de triglycérides mais aussi par l’augmentation de l'activité du CYP2E1. Pour cela, des cellules humaines HepaRG différenciées ont été incubées pendant une semaine avec de l'acide stéarique ou de l'acide oléique, en présence de 3 concentrations différentes d'insuline. Les triglycérides cellulaires et l'expression de gènes induits au cours de la stéatose étaient similaires avec les deux acides gras. Cependant, l'activité du CYP2E1 était significativement augmentée uniquement par le stéarate et ceci était associé à une diminution de l'activité du CYP3A4, une autre caractéristique des NAFLD. L’activité du CYP2E1 dans les cellules HepaRG était réduite par l'insuline d'une manière concentration-dépendante et cet effet était reproduit sur des hépatocytes humains en culture primaire. Ainsi, l'activité du CYP2E1 était la plus élevée dans les cellules HepaRG cultivées avec du stéarate et sans insuline. Le 2ème but de notre étude était ensuite d'évaluer la cytotoxicité de l’APAP sur des cellules HepaRG présentant ou non une stéatose et une induction du CYP2E1. Des expériences avec une large gamme de concentrations d’APAP (de 1 à 20 mM) indiquaient que la perte cellulaire d'ATP et du glutathion (GSH) était presque toujours plus forte en présence de stéarate. Dans les cellules prétraitées avec le chlorméthiazole (CMZ, un inhibiteur du CYP2E1), la moindre diminution d’ATP était plus importante en présence de stéarate, avec de faibles (2,5 mM) ou de fortes (20 mM) concentrations d’APAP. Cependant, en l'absence d'insuline, la moindre chute d’ATP induite par le CMZ était significativement plus forte uniquement pour 20 mM d’APAP. Étonnamment, suite au prétraitement par le CMZ, il n'y avait pas de protection vis-à-vis de la diminution du GSH et de la formation des adduits APAP-protéines. Enfin, les concentrations du métabolite APAP-glucuronide étaient significativement augmentées en présence d'insuline. Ainsi, lorsqu’elle est étudiée dans des conditions spécifiques de culture, la lignée cellulaire HepaRG semble être un modèle intéressant de NAFLD, notamment en ce qui concerne les activités du CYP2E1 et du CYP3A4. Nos données suggèrent aussi que l’induction du CYP2E1 observée au cours des NAFLD pourrait être secondaire à l'accumulation de certains acides gras et à la présence d’une faible signalisation insulinique dans le foie. Ainsi, ce modèle cellulaire peut être utilisé pour mettre en évidence les principaux facteurs métaboliques et hormonaux favorisant hépatotoxicité de l’APAP chez les personnes obèses. Cette thèse inclut également une revue de la littérature sur l’hépatotoxicité de l’APAP dans le contexte de l’obésité et des NAFLD (Michaut et al., Liver Int 2014). / Obesity and nonalcoholic fatty liver disease (NAFLD) are able to increase the risk and the severity of hepatotoxicity induced by some xenobiotics including drugs, but the involved mechanisms are still poorly understood. For toxic compounds such as ethanol and acetaminophen (APAP), a role of hepatic cytochrome P450 2E1 (CYP2E1) is suspected since the activity of this enzyme is consistently enhanced during obesity and NAFLD. The first aim of our experimental study was to set up a cellular model of NAFLD characterized not only by triglyceride accumulation but also by higher CYP2E1 activity. To this end, differentiated human HepaRG cells were incubated during one week with stearic acid, or oleic acid, in the presence of 3 different concentrations of insulin. Cellular triglycerides and the expression of lipid-responsive genes were similar with both fatty acids. However, CYP2E1 activity was significantly increased only by stearate and this was associated with lower CYP3A4 activity, another metabolic feature reported in NAFLD. CYP2E1 activity in HepaRG cells was reduced by insulin in a concentration-dependent manner and this effect was reproduced in cultured primary human hepatocytes. Hence, the highest CYP2E1 activity was observed in HepaRG cells with stearate and without insulin. Next, the second aim of our study was to assess APAP cytotoxicity in HepaRG cells presenting or not lipid accretion and CYP2E1 induction. Experiments with a large range of APAP concentrations (1 to 20 mM) showed that the cellular loss of ATP and glutathione (GSH) was almost always stronger in the presence of stearic acid. In cells pretreated with the CYP2E1 inhibitor chlormethiazole (CMZ), recovery of cellular ATP was significantly higher in the presence of stearic acid with both low (2.5 mM) and high (20 mM) concentrations of APAP. However, in the absence of insulin, CMZ-induced ATP recovery was significantly greater only for 20 mM of APAP. Surprisingly, there was no recovery of cellular GSH and no reduction of APAP-protein adducts following CMZ pretreatment. Finally, levels of APAP-glucuronide were significantly enhanced in the presence of insulin. Hence, when studied in specific conditions of culture, the HepaRG cell line can be a valuable model of human NAFLD, especially regarding CYP2E1 and CYP3A4 activity. Our data also suggest that higher CYP2E1 activity in NAFLD could be secondary to the hepatic accumulation of some fatty acids and to the presence of low insulin signaling. This cellular model can be thus used to unveil the main metabolic and hormonal factors favoring APAP hepatotoxicity in obese individuals. This thesis also includes a review on APAP hepatotoxicity in the context of obesity and NAFLD (Michaut et al., Liver Int 2014).

Muitos autores associam as doenças alcoólicas hepáticas às deficiências nutricionais. Por outro lado, trabalhos experimentais estabelecem que a hepatotoxidade alcoólica relaciona-se especialmente à geração de espécies reativas através do sistema microsomal que oxida etanol via citocromo 450, principalmente o CYP2E1. O CYP2E1 hepático tem a capacidade de ativar algumas drogas comumente utilizadas, como o acetaminofeno, em seus metabólitos mais tóxicos e promover carcinogênese. Além. disso, o metabolismo pelo CYP2E1 resulta num aumento na produção de espécies reativas, com diminuição nos sistemas de defesa antioxidantes, estabelecendo o estresse oxidativo. Como a expressão do CYP2E1 é muito influenciada por fatores nutricionais e hormonais, este trabalho descreve os efeitos do tratamento com etanol nos níveis de CYP2E1 e sua relação com alguns parâmetros pró- e antioxidantes, considerando três modelos experimentais diferentes. Ratos machos Sprague Dawley com cerca de três meses de idade receberam ad lib. ração Purina (Purina Ind., Brasil) e, separadamente, uma solução 25 % etanol-20%sacarose durante 1, 2, 3 ou 4 semanas. Os grupos controles foram isocaloricamente pareados aos animais que consumiram etanol, ou receberam quantidades de sacarose equivalentes às calorias recebidas com o consumo de etanol. 18 h antes do sacrifício os animais foram mantidos em abstinência alcoólica, recebendo água e ração ou apenas água ad lib. Os resultados indicam que o consumo de etanol pode ser associado à estabilização do CYP2E1. No entanto, nas nossas condições experimentais, a presença da isoforma não está associada ao estresse oxidativo. Esses resultados indicam que as deficiências nutricionais, especialmente o baixo consumo de carboidratos, são fundamentais na potenciação do estresse oxidativo induzido pelo etanol. / Many authors have attributed alcoholic liver disease to dietary deficiencies. On the other hand, experimental studies have established that alcohol hepatotoxicity is especially related to the generation of oxidant species through its microsomal metabolism via cytochrome P-450, mainly CYP2E1. Liver CYP2E1 has a high capacity to activate some commonly used drugs, such as acetaminophen, to their toxic metabolites, and to promote carcinogenesis. Moreover, metabolism by CYP2E1 results in a significant reactive oxygen species (ROS) release, accompanied by the defense systems decrease against oxidative stress. Since the expression of CYP2E1 is very much influenced by hormonal and nutritional factors, this study describes the effects of ethanol treatment on CYP2E 1 levels and their relationship with some pro and antioxidant parameters considering three experimental models. Male Sprague-Dawley rats were fed ad. lib. for 1, 2, 3 or 4 weeks a commercial diet (Purina Ind., Brazil) plus a 25% ethanol-20% sucrose solution. Control groups were isocalorically pair-feed to the leading ethanol-consuming animals, or received isocaloric amounts of sucrose for pairing only ethanol calories. Eighteen hours before sacrifice ethanol was withdrawal and animals had only free access to tap water or they were offered food and water ad. lib. Results have shown that ethanol administration was associated with CYP2E1 stabilization although under our experimental condition it was not associated with any oxidative stress. These findings indicate that dietary deficiencies, especially low carbohydrate intake are crucial in the potentiation of the ethanol-induced oxidative stress.

Yang Lei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 141-148). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abstract (Chinese Version) --- p.iv / Table of Contents --- p.vi / List of Abbreviations --- p.xii / List of Figures --- p.xiii / List of Tables --- p.xviii / Chapter Chapter 1 --- Literature review --- p.1 / Chapter 1.1 --- Carbon tetrachloride (CC14) --- p.1 / Chapter 1.2 --- Major uses of CC14 --- p.1 / Chapter 1.3 --- Potential human exposure pathways to CC14 --- p.2 / Chapter 1.4 --- Toxicity of CC14 --- p.3 / Chapter 1.5 --- Mechanism of CCl4-induced hepatotoxicity --- p.5 / Chapter 1.6 --- Role of CYP2E1 involved in CCl4-induced hepatotoxicity --- p.7 / Chapter 1.7 --- Definite proof of the involvement of CYP2E1 in CCl4-induced hepatotoxicity by CYP2El-null mouse in vivo model --- p.10 / Chapter 1.8 --- Identification of CYP2E1 -dependent genes involved in CCl4-induced hepatotoxicity by fluorescent differential display (FDD) --- p.11 / Chapter 1.9 --- Objectives of the study --- p.14 / Chapter Chapter 2 --- Materials and methods --- p.16 / Chapter 2.1 --- Animals and treatments --- p.16 / Chapter 2.1.1 --- Materials --- p.16 / Chapter 2.1.2 --- Methods --- p.16 / Chapter 2.2 --- Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) analyses --- p.17 / Chapter 2.2.1 --- Materials --- p.17 / Chapter 2.2.2 --- Methods --- p.17 / Chapter 2.2.2.1 --- Serum preparation --- p.17 / Chapter 2.2.2.2 --- Activity determination --- p.18 / Chapter 2.3 --- Tail-genotyping by PCR --- p.18 / Chapter 2.3.1 --- Materials --- p.18 / Chapter 2.3.2 --- Methods --- p.20 / Chapter 2.3.2.1 --- Preparation of genomic DNA from mouse tail --- p.20 / Chapter 2.3.2.2 --- PCR reaction --- p.20 / Chapter 2.4 --- Total RNA isolation --- p.21 / Chapter 2.4.1 --- Materials --- p.21 / Chapter 2.4.2 --- Methods --- p.21 / Chapter 2.5 --- DNase I treatment --- p.23 / Chapter 2.5.1 --- Materials --- p.23 / Chapter 2.5.2 --- Methods --- p.23 / Chapter 2.6 --- Reverse transcnption of mRNA and amplification by fluorescent PCR amplification --- p.26 / Chapter 2.6.1 --- Materials --- p.27 / Chapter 2.6.2 --- Methods --- p.27 / Chapter 2.7 --- Fluorescent differential display (FDD) --- p.28 / Chapter 2.7.1 --- Materials --- p.28 / Chapter 2.7.2 --- Methods --- p.28 / Chapter 2.8 --- Excision of differentially expressed cDNA fragments --- p.29 / Chapter 2.8.1 --- Materials --- p.29 / Chapter 2.8.2 --- Methods --- p.29 / Chapter 2.9 --- Reamplification of differentially expressed cDNA fragments --- p.34 / Chapter 2.9.1 --- Materials --- p.34 / Chapter 2.9.2 --- Methods --- p.34 / Chapter 2.10 --- Subcloning of reamplified cDNA fragments --- p.36 / Chapter 2.10.1 --- Materials --- p.36 / Chapter 2.10.2 --- Methods --- p.37 / Chapter 2.11 --- Purification of plasmid DNA from recombinant clones --- p.39 / Chapter 2.11.1 --- Materials --- p.39 / Chapter 2.11.2 --- Methods --- p.39 / Chapter 2.12 --- DNA sequencing of differentially expressed cDNA fragments --- p.40 / Chapter 2.12.1 --- Materials --- p.40 / Chapter 2.12.2 --- Methods --- p.40 / Chapter 2.12.3 --- BLAST search against the GenBank DNA databases --- p.41 / Chapter 2.13 --- Northern blot analysis of differentially expressed cDNA fragments --- p.41 / Chapter 2.13.1 --- Formaldehyde gel electrophoresis of total RNA --- p.41 / Chapter 2.13.1.1 --- Materials --- p.42 / Chapter 2.13.1.2 --- Methods --- p.42 / Chapter 2.13.2 --- Preparation of cDNA probes for hybridization --- p.42 / Chapter 2.13.2.1 --- EcoRI digestion of cDNA inserts from plasmid DNA --- p.42 / Chapter 2.13.2.1.1 --- Materials --- p.42 / Chapter 2.13.2.1.2 --- Methods --- p.43 / Chapter 2.13.2.2 --- Purification of DNA from agarose gel --- p.43 / Chapter 2.13.2.2.1 --- Materials --- p.43 / Chapter 2.13.2.2.2 --- Methods --- p.43 / Chapter 2.13.2.3 --- DIG labeling of cDNA --- p.44 / Chapter 2.13.2.3.1 --- Materials --- p.44 / Chapter 2.13.2.3.2 --- Methods --- p.44 / Chapter 2.13.3 --- Hybridization --- p.45 / Chapter 2.13.3.1 --- Materials --- p.45 / Chapter 2.13.3.2 --- Methods --- p.45 / Chapter Chapter 3 --- Results --- p.47 / Chapter 3.1 --- Liver morphology --- p.47 / Chapter 3.2 --- Serum ALT and AST activities --- p.47 / Chapter 3.3 --- Tail-genotyping by PCR --- p.51 / Chapter 3.4 --- DNase I treatment --- p.51 / Chapter 3.5 --- FDD RT-PCR and excision of differentially expressed cDNA fragments --- p.51 / Chapter 3.6 --- Reamplification of excised cDNA fragments --- p.61 / Chapter 3.7 --- Subcloning of reamplified cDNA fragments --- p.61 / Chapter 3.8 --- DNA sequencing of subcloned cDNA fragments --- p.69 / Chapter 3.9 --- Confirmation of differentially expressed patterns by Northern blot analysis --- p.106 / Chapter 3.10 --- Temporal expression of differentially expressed genes --- p.113 / Chapter 3.11 --- Tissue distribution of differentially expressed genes --- p.117 / Chapter Chapter 4 --- Discussion --- p.125 / Chapter 4.1 --- Liver morphology and serum ALT and AST activities --- p.126 / Chapter 4.2 --- Identification of CYP2E1 -dependent genes involved in CCl4-induced hepatotoxicity --- p.127 / Chapter 4.3 --- Functional roles of the identified differentially expressed genes --- p.129 / Chapter 4.3.1 --- Fragment B4 --- p.129 / Chapter 4.3.2 --- Fragment C12 --- p.130 / Chapter 4.3.3 --- Fragment B13 --- p.131 / Chapter 4.3.4 --- Fragment A5 --- p.132 / Chapter 4.4 --- Temporal expression of differentially expressed genes --- p.133 / Chapter 4.4.1 --- Fragment B4 --- p.133 / Chapter 4.4.2 --- Fragment C12 --- p.134 / Chapter 4.4.3 --- Fragment B13 --- p.134 / Chapter 4.4.4 --- Fragment A5 --- p.135 / Chapter 4.5 --- Tissue distribution of differentially expressed genes --- p.136 / Chapter 4.5.1 --- Fragment B4 --- p.136 / Chapter 4.5.2 --- Fragment C12 --- p.136 / Chapter 4.5.3 --- Fragment B13 --- p.137 / Chapter 4.5.4 --- Fragment A5 --- p.137 / Chapter 4.5.5 --- Roles of the identified genes involved in CCl4-induced hepatotoxicity --- p.138 / Chapter 4.6 --- Normalization of Northern blot analysis --- p.13 8 / Chapter 4.7 --- Limitations of FDD technique to identify differentially expressed genes --- p.138 / Chapter 4.8 --- Future studies --- p.139 / Chapter 4.8.1 --- Investigation of the differential expression patterns of the identified genes in acetaminophen-induced liver injury --- p.139 / Chapter 4.8.2 --- Dot blot analysis --- p.140 / Chapter 4.8.3 --- DNA microarray --- p.140 / References --- p.141