RESUMEN
AIMS/HYPOTHESIS: The pancreas and hypothalamus are critical for maintaining nutrient and energy homeostasis, and combined disorders in these organs account for the onset of the metabolic syndrome. Activating transcription factor 3 (ATF3) is an adaptive response transcription factor. The physiological role of ATF3 in the pancreas has been controversial, and its role in the hypothalamus remains unknown. To elucidate the roles of ATF3 in these organs, we generated pancreas- and hypothalamus-specific Atf3 knockout (PHT-Atf3-KO) mice in this study. METHODS: We crossed mice bearing floxed Atf3 alleles with Pdx1-cre mice, in which cre is specifically expressed in the pancreas and hypothalamus, and analysed metabolic variables, pancreatic morphology, food intake, energy expenditure and sympathetic activity in adipose tissue. We also used a hypothalamic cell line to investigate the molecular mechanism by which ATF3 regulates transcription of the gene encoding agouti-related protein (Agrp). RESULTS: Although PHT-Atf3-KO mice displayed better glucose tolerance, neither plasma glucagon nor insulin level was altered in these mice. However, these mice exhibited higher insulin sensitivity, which was accompanied by a leaner phenotype due to decreased food intake and increased energy expenditure. We also observed decreased hypothalamic Agrp expression in PHT-Atf3-KO mice. Importantly, an increase in ATF3 levels is induced by fasting or low glucose in the hypothalamus. We also showed that ATF3 interacts with forkhead box-containing protein, O subfamily 1 (FoxO1) on the Agrp promoter and activates Agrp transcription. CONCLUSIONS/INTERPRETATION: Our results suggest that ATF3 plays an important role in the control of glucose and energy metabolism by regulating Agrp.
Asunto(s)
Factor de Transcripción Activador 3/metabolismo , Proteína Relacionada con Agouti/metabolismo , Metabolismo Energético , Glucosa/metabolismo , Hipotálamo/metabolismo , Alelos , Animales , Línea Celular , Proteína Forkhead Box O1 , Factores de Transcripción Forkhead/metabolismo , Insulina/metabolismo , Integrasas/metabolismo , Islotes Pancreáticos/metabolismo , Síndrome Metabólico/genética , Ratones , Ratones Noqueados , Fenotipo , Regiones Promotoras Genéticas , Factores de TiempoRESUMEN
OBJECTIVE: To evaluate the effectiveness of disease-modifying antirheumatic drugs, namely, methotrexate (MTX), sulfasalazine (SSZ) and bucillamine (BUC) at low-doses (4, 6 or 8 mg MTX, 500 or 1,000 mg SSZ, and 100 or 200 mg BUC) in 1,358 patients with a follow-up of at least 12 months and more than 120 months. METHODS: Clinical assessments were based on the number of painful joints (NPJ) and that of swollen joints (NSJ), CRP level, erythrocyte sedimentation rate, rheumatoid factor level and morning stiffness before and after treatment. Results were evaluated on the basis of the duration of treatment for each drug with inefficacy or inadequate efficacy as one endpoint for discontinuation and adverse drug reactions (ADRs) as the other in single agent and combination therapy. The incidence and nature of ADRs in single and combination treatment are described. RESULTS: The effects of MTX, SSZ and BUC on clinical parameters were monitored over the first three months, and in particular, NPJs and NSJs were found to decrease significantly during single agent MTX or BUC treatment over 108 months. CRP levels remained significantly improved for more than 120 months with MTX. In the single and combination long-term treatments, continuation rate with inefficacy or inadequate efficacy as the end point achieved for each of the treatments were 83.1% for MTX, 76.0% for BUC, 68.5% for SSZ, and in the case of the combination treatments, these rates were 83.3% for MTX + BUC and 71.0% for MTX+SSZ. Continuation rates using ADRs as the end point were 88% for SSZ, 79.6% for BUC and 79.4% for MTX. The incidences of ADRs for the various treatments were: MTX 22.2%, SSZ 11.0%, BUC 20.6%, MTX + BUC 30.0% and MTX + SSZ 31.2%. CONCLUSION: MTX showed the highest efficacy even though it was administrated at a low dose (6-8 mg), as a single agent or in combination with other treatment. However, in combination treatments, the continuous duration of treatment ending in ADRs as the end point were lower than those in single treatments with MTX, SSZ and BUC.
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Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Cisteína/análogos & derivados , Metotrexato/uso terapéutico , Sulfasalazina/uso terapéutico , Artritis Reumatoide/fisiopatología , Cisteína/uso terapéutico , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Quimioterapia Combinada , Femenino , Humanos , Articulaciones/efectos de los fármacos , Articulaciones/patología , Articulaciones/fisiopatología , Masculino , Persona de Mediana Edad , Dolor/tratamiento farmacológico , Dolor/patología , Dolor/fisiopatología , Prednisolona/uso terapéutico , Resultado del TratamientoRESUMEN
Monkey P450 1A1 cDNA (MKah1) was isolated from the lambda gt11 cDNA library of a liver from a 3-methylcholanthrene (3MC)-treated crab-eating monkey using a dog P450 1A1 cDNA fragment as a probe. MKah1 was 2453 bp long and contained an entire coding region for a polypeptide of 512 residues. The nucleotide and deduced amino acid sequences of MKah1 displayed 95% and 94% identity with those of the human P450 1A1 gene, respectively. Even in the 3' noncoding region, MKah1 showed 94% homology with human P450 1A1, whereas it showed less than 69% homology with other mammalian P450 1A1. Monkey P450 1A1 mRNA was not detectable in untreated livers, but was induced by polychlorinated biphenyl and 3MC. The expression plasmid (designated as pMKC-1) was constructed by introduction of the coding region of MKah1 into a yeast expression vector (pAM82) containing the promoter of acid phosphatase (APase). Northern blot analysis revealed that monkey P450 1A1 mRNA was expressed in yeast under the control of the APase promoter. Microsomes from yeast transformed by pMKC-1 catalyzed 7-ethoxycoumarin O-deethylation, benzo(a)pyrene hydroxylation and the mutagenic activation of 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ), 3-amino-1-methyl-5H-pyrido(4,3-b)-indole acetate (Trp-P-2) and 2-amino-6-methyldipyrido(1,2-a:3',2'-d)imidazole acetate (Glu-P-1).
Asunto(s)
Sistema Enzimático del Citocromo P-450/genética , Haplorrinos/genética , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Codón/análisis , ADN/aislamiento & purificación , Femenino , Hígado/enzimología , Metilcolantreno , Datos de Secuencia Molecular , ARN Mensajero/aislamiento & purificación , Saccharomyces cerevisiae/enzimologíaRESUMEN
Three cDNAs coding for monkey cytochrome P-450 (P450) 2C, 2E and 3A (MKmp13, MKj1 and MKnf2, respectively) were isolated from a lambda gt11 cDNA library of a liver from a 3-methylcholanthrene (3MC)-treated crab-eating monkey, using cDNA fragments for human P450 2C, 2E and 3A as respective probes. MKmp13 and MKnf2 were 1901 and 2032 bp long, containing entire coding regions for polypeptides of 490 and 503 residues, respectively. The deduced N-terminal amino acid sequences of MKmp13 and MKnf2 were identical with those of P450-MK1 and P450-MK2, which had been purified from liver microsomes of untreated and polychlorinated biphenyl (PCB)-treated crab-eating monkeys, respectively. MKj1 was 1508 bp long, encoding a polypeptide of 449 residues, which is presumed to lack N-terminal 45 residues as compared with the sequence for human P450 2E1. Northern blot analysis indicated that monkey P450 2C, 2E and 3A mRNAs were expressed constitutively in monkey livers. P450 2E and 3A mRNAs were induced by both 3MC and PCB, while P450 2C mRNA was induced only by PCB. The deduced amino acid sequences of four monkey cytochrome P-450 cDNAs, including P450 1A1 (MKah1) which we isolated previously, were more than 92% identical with those of corresponding human cytochrome P-450 cDNAs.
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Sistema Enzimático del Citocromo P-450/genética , ADN/genética , Hígado/enzimología , Familia de Multigenes , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Biblioteca de Genes , Humanos , Macaca fascicularis , Datos de Secuencia Molecular , ARN/genética , ARN/aislamiento & purificación , Homología de Secuencia de AminoácidoRESUMEN
The steric contact spaces associated with the reaction of the enantiomeric isomers of 7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (I) with the exocyclic amino group of guanine of dinucleoside dimer structures were examined for a fixed transition-state geometry. This reaction is sterically prohibited for the B form DNA conformation. If, however, the nucleic acid structure is deformed, such that the distance between two adjacent base pairs (one containing guanine and cytosine) is maximized, sterically allowed transition-state geometries can be identified. It was not possible to uniquely identify the preferred transition-state complex with respect to nucleic acid structure or isomer of I. However, two types of general transition-state geometries were observed. In one, I was located "outside" the nucleic acid structure; in the other geometry, I was intercalated between adjacent base pairs in the transition state. The intercalation process might serve as a physical catalyst for the alkylation of NH2-guanine by I.
Asunto(s)
Benzopirenos/metabolismo , ADN/metabolismo , 7,8-Dihidro-7,8-dihidroxibenzo(a)pireno 9,10-óxido , Alquilación , Fenómenos Químicos , Química Física , Conformación de Ácido Nucleico , EstereoisomerismoRESUMEN
Gilvocarcin V was chemically transformed to alter its biological activities as well as its solubility by mainly focusing on the vinyl side chain. The oxirane and oxime derivatives showed slightly decreased in vivo antitumor activity, while the aminoethylmorpholine derivative turned out to be soluble in some organic solvents.
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Aminoglicósidos , Antibacterianos/química , Antibióticos Antineoplásicos/química , Animales , Antibacterianos/farmacología , Antibióticos Antineoplásicos/farmacología , Cumarinas , Glicósidos , Leucemia P388/tratamiento farmacológico , Ratones , SolubilidadAsunto(s)
ADN/metabolismo , Alquilantes/metabolismo , Alquilación , Secuencia de Bases , Doxorrubicina/metabolismo , Etidio/metabolismo , Sustancias Intercalantes/metabolismo , Modelos Biológicos , Modelos Moleculares , Conformación de Ácido Nucleico , Oligodesoxirribonucleótidos/metabolismo , Teoría Cuántica , TermodinámicaRESUMEN
The NDDO semiempirical molecular orbital method (Kikuchi, 1977; Kikuchi and Maeda, 1977) was used to model proposed nonenzymatic metabolic pathways for the decomposition of methazoxymethanol (MAM) to a methyldiazonium ion. It was found that the lowest transition path involved protonation of the azoxy oxygen atom to form a six-membered transition state structure which decomposes to the methyldiazonium ion, CH2O, and a hydroxyl ion. This metabolic pathway is consistent with models proposed by Druckrey and Lange (1972) and Miyadera (1975). The calculations also suggest that methylazoxyformaldehyde, an enzymatic product of MAM, may directly alkylate to nucleic acid base sites.
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Compuestos Azo/metabolismo , Acetato de Metilazoximetanol/metabolismo , Animales , Biotransformación , Fenómenos Químicos , Química , Acetato de Metilazoximetanol/análogos & derivados , Conformación MolecularRESUMEN
The NDDO semiempirical molecular orbital method (Kikuchi, 1977; Kikuchi and Maeda, 1977) was used to characterize the reactivities of methylazoxy-methanol (MAM) and its metabolites with DNA nucleophilic base sites. The physical association of MAM was found to occur at the guanine N7 and 06 atoms, while the ultimate alkylation reaction by MAM was predicted to occur at the guanine N7 atom more easily than at the 06 atom of guanine. These trends were also observed in the results for MAM metabolites, methylazoxy formaldehyde (MAF) and methyloazoxy carboxylic acid (MAA), and can explain the experimentally observed selectivity of MAM alkylation on DNA bases (Matsumoto and Higa, 1966; Schank and Magee, 1967). Although the methyldiazonium ion has the highest reactivity with the guanine N7 atom among the MAM metabolites, it is proposed that MAF is another candidate to react directly with the N7 atom of guanine.
Asunto(s)
Compuestos Azo , ADN , Acetato de Metilazoximetanol , Citosina , Guanina , Enlace de Hidrógeno , Metilación , Conformación Molecular , TermodinámicaRESUMEN
Vase solution containing 2% sucrose prevented the deterioration of chrysanthemum (Dendranthema grandiflorum Kitamura) cut flowers induced by gamma-rays at 750 Gy. Glucose, fructose, and sucrose in florets and leaves of irradiated chrysanthemums decreased more rapidly than those of unirradiated ones, when the cut chrysanthemums were held in a vase solution without sucrose. The sugar contents of florets and leaves and the respiratory rate of irradiated chrysanthemums held with sucrose remained at higher levels than those of unirradiated ones. Incorporation of (14)C from [(14)C]sucrose into CO2 was increased by irradiation. Incorporation of [α-(32)P]dTTP into trichloroacetic acid (TCA) insoluble substances in florets was increased by irradiation and by exogenous sucrose supply. These results suggest that sucrose in a vase solution was used as a respiratory substrate and facilitated the repair of radiation-induced damage, resulting in the extension of longevity of irradiated chrysanthemums.
RESUMEN
We describe a 10-year-old girl with systemic lupus erythematosus (SLE) who first presented with hemolytic uremic syndrome (HUS). Diagnoses were based on the classic HUS triad, including the observation of fragmented red blood cells, and on the American College of Rheumatology criteria for SLE. Plasma exchange may have been effective against both HUS and SLE in this patient, as it was associated with improvement of platelet counts, renal function, and serological findings.