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1.
J Vet Pharmacol Ther ; 37(6): 589-94, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24903569

RESUMO

Closantel (CLS) is currently used in programs for the strategic control of gastrointestinal nematodes. CLS is extralabel used in different dairy goat production systems. From available data in dairy cows, it can be concluded that residues of CLS persist in milk. The current work evaluated the concentration profiles of CLS in plasma and milk from lactating orally treated dairy goats to assess the residues pattern in dairy products such as cheese and ricotta. Six (6) female Saanen dairy goats were treated orally with CLS administered at 10 mg/kg. Blood and milk samples were collected between 0 and 36 days post-treatment. The whole milk production was collected at 1, 4, 7, and 10 days post-treatment to produce soft cheese and ricotta. CLS concentrations in plasma, milk, cheese, whey, and ricotta were determined by HPLC. The concentrations of CLS measured in plasma were higher than those measured in milk at all sampling times. However, the calculated withdrawal time for CLS in milk was between 39 and 43 days postadministration to dairy goats. CLS residual concentrations in cheese (between 0.93 and 1.8 µg/g) were higher than those measured in the milk used for its production. CLS concentrations in ricotta were sixfold higher than those in the milk and 20-fold higher than those in the whey used for its production. The persistent and high residual concentrations of CLS in the milk and in the cheese and ricotta should be seriously considered before issuing any recommendation on the extralabel use of CLS in dairy goat farms.


Assuntos
Antinematódeos/farmacocinética , Queijo/análise , Resíduos de Drogas/análise , Cabras/metabolismo , Leite/química , Salicilanilidas/farmacocinética , Animais , Antinematódeos/análise , Antinematódeos/sangue , Feminino , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Doenças das Cabras/prevenção & controle , Salicilanilidas/análise , Salicilanilidas/sangue
2.
Cell Death Differ ; 15(3): 515-20, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18049476

RESUMO

X-linked inhibitor of apoptosis protein (XIAP) is a member of the inhibitor of apoptosis proteins family that selectively binds and inhibits caspase-3, -7 and -9. As such, XIAP is an extremely potent suppressor of apoptosis and an attractive target for cancer treatment. Che-1 is an antiapoptotic agent involved in the control of gene transcription and cell proliferation. Recently, we showed that the checkpoint kinases ATM/ATR and checkpoint kinase 2 physically and functionally interact with Che-1 and promote its phosphorylation and accumulation in response to DNA damage. These Che-1 modifications induce transcription of p53, and Che-1 depletion strongly sensitizes tumor cells to anticancer drugs. Here we show that Che-1 activates XIAP expression in response to DNA damage. This effect is mediated by Che-1 phosphorylation and requires NF-kappaB. Notably, we found that XIAP expression is necessary for antiapoptotic activity of Che-1 and that in vivo downregulation of Che-1 by small interference RNA strongly enhanced the cytotoxicity of anticancer drugs.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Apoptose , Dano ao DNA , Proteínas Repressoras/fisiologia , Fatores de Transcrição/fisiologia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/biossíntese , Animais , Proteínas Reguladoras de Apoptose/antagonistas & inibidores , Proteínas Reguladoras de Apoptose/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Masculino , Camundongos , Camundongos Nus , NF-kappa B/metabolismo , Células NIH 3T3 , Interferência de RNA , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/genética , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética , Ativação Transcricional , Regulação para Cima , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética
3.
Mol Cell Biol ; 21(17): 6080-9, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11486045

RESUMO

HERP1 and -2 are members of a new basic helix-loop-helix (bHLH) protein family closely related to HES/E(spl), the only previously known Notch effector. Like that of HES, HERP mRNA expression is directly up-regulated by Notch ligand binding without de novo protein synthesis. HES and HERP are individually expressed in certain cells, but they are also coexpressed within single cells after Notch stimulation. Here, we show that HERP has intrinsic transcriptional repression activity. Transcriptional repression by HES/E(spl) entails the recruitment of the corepressor TLE/Groucho via a conserved WRPW motif, whereas unexpectedly the corresponding-but modified-tetrapeptide motif in HERP confers marginal repression. Rather, HERP uses its bHLH domain to recruit the mSin3 complex containing histone deacetylase HDAC1 and an additional corepressor, N-CoR, to mediate repression. HES and HERP homodimers bind similar DNA sequences, but with distinct sequence preferences, and they repress transcription from specific DNA binding sites. Importantly, HES and HERP associate with each other in solution and form a stable HES-HERP heterodimer upon DNA binding. HES-HERP heterodimers have both a greater DNA binding activity and a stronger repression activity than do the respective homodimers. Thus, Notch signaling relies on cooperation between HES and HERP, two transcriptional repressors with distinctive repression mechanisms which, either as homo- or as heterodimers, regulate target gene expression.


Assuntos
Sequências Hélice-Alça-Hélice , Proteínas de Homeodomínio/metabolismo , Proteínas de Membrana/metabolismo , Proteínas , Proteínas Repressoras/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Células 3T3 , Sequência de Aminoácidos , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Sítios de Ligação , Células COS , Chlorocebus aethiops , Proteínas Correpressoras , DNA/metabolismo , Dimerização , Regulação da Expressão Gênica , Células HeLa , Histona Desacetilases/metabolismo , Humanos , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase , Camundongos , Dados de Sequência Molecular , Proteínas Nucleares/metabolismo , Correpressor 1 de Receptor Nuclear , Receptores Notch , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/genética , Complexo Correpressor Histona Desacetilase e Sin3 , Soluções , Fatores de Transcrição HES-1 , Transcrição Gênica
4.
Eura Medicophys ; 42(2): 97-102, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16767057

RESUMO

AIM: Chronic fatigue syndrome (CFS) is an illness characterised by disabling fatigue of uncertain aetiology and other nonspecific symptoms. Typically CFS patients complain of a severe fatigue made worse by exercise, with a consistent reduction of working activity. A physical deconditioning could explain CFS features as well as a neuromuscular dysfunction, of central or peripheric origin. METHODS: Ten CFS patients were enrolled in a protocol of a rehabilitative treatment over a six-month period: they underwent a submaximal and predominantly aerobic exercise with a reduced O2 consumption using a Galileo 2000 system that provides mechanical vibrations characterised by sinusoid vertical sollecitations. Before and after such treatment, all patients underwent a pressure pain thresholds profile, an evaluation of physical and psychosocial parameters using the visual analogue scale (VAS) of Scott-Huskisson, and a muscle performance analysis by the CIBEX 6000 dynamometer. RESULTS: After the six-month period of study there was an overall improvement of the above described parameters as compared to the basal determinations. CONCLUSION: We conclude that the rehabilitative exertion provides an useful treatment for CFS patients particularly to realize an effective training of the explosive strength.


Assuntos
Terapia por Exercício/métodos , Síndrome de Fadiga Crônica/reabilitação , Vibração/uso terapêutico , Adulto , Síndrome de Fadiga Crônica/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Medição da Dor , Limiar da Dor , Estatísticas não Paramétricas , Resultado do Tratamento
5.
Cell Death Dis ; 6: e1764, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25996291

RESUMO

The tumor suppressor p53 is mainly involved in the transcriptional regulation of a large number of growth-arrest- and apoptosis-related genes. However, a clear understanding of which factor/s influences the choice between these two opposing p53-dependent outcomes remains largely elusive. We have previously described that in response to DNA damage, the RNA polymerase II-binding protein Che-1/AATF transcriptionally activates p53. Here, we show that Che-1 binds directly to p53. This interaction essentially occurs in the first hours of DNA damage, whereas it is lost when cells undergo apoptosis in response to posttranscriptional modifications. Moreover, Che-1 sits in a ternary complex with p53 and the oncosuppressor Brca1. Accordingly, our analysis of genome-wide chromatin occupancy by p53 revealed that p53/Che1 interaction results in preferential transactivation of growth arrest p53 target genes over its pro-apoptotic target genes. Notably, exposure of Che-1(+/-) mice to ionizing radiations resulted in enhanced apoptosis of thymocytes, compared with WT mice. These results confirm Che-1 as an important regulator of p53 activity and suggest Che-1 to be a promising yet attractive drug target for cancer therapy.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose/genética , Proteína BRCA1/metabolismo , Pontos de Checagem do Ciclo Celular/genética , Proteínas Repressoras/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Linhagem Celular Tumoral , Dano ao DNA/genética , Reparo do DNA/genética , Ativação Enzimática/genética , Regulação da Expressão Gênica , Células HCT116 , Humanos , Células MCF-7 , Camundongos , Camundongos Transgênicos , Ligação Proteica/genética , Interferência de RNA , RNA Interferente Pequeno , Proteínas Repressoras/genética , Timócitos/patologia , Timócitos/efeitos da radiação , Ativação Transcricional/genética , Proteína Supressora de Tumor p53/genética
6.
Pain ; 71(2): 187-97, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9211480

RESUMO

Pain symptoms of many disorders are reported to vary with menstrual stage. This study investigated how pain thresholds to electrical stimulation of the skin, subcutis and muscle tissue varied with menstrual stage in normal women and compared these variations with those in women with dysmenorrhea and in healthy men at matched intervals. Thresholds of the three tissues were measured four times during the course of one menstrual cycle at four sites. Two of the sites were on the abdomen within the uterine viscerotome (abdomen-rectus abdominis, left and right) and two were outside it on the limbs (leg-quadriceps, arm-deltoid). Calculated from the beginning of menstruation (day 0), the menstrual phases studied were menstrual (days 2-6), periovulatory (days 12-16), luteal (days 17-22) and premenstrual (days 25-28). Spontaneous pain associated with menstruation was measured from diary estimates on a VAS scale. Whereas the highest thresholds always occurred in the luteal phase regardless of segmental site or stimulus depth, the lowest thresholds occurred in the periovulatory stage for skin, whereas those for muscle/subcutis occurred perimenstrually. Dysmenorrhea accentuated the impact of menstrual phase. For non-dysmenorrheic women menstrual trends were significant only in abdominal muscle and subcutis, but for dysmenorrheic women the trends were also significant in abdominal skin and in limb muscle and subcutis. Dysmenorrhea also lowered thresholds mainly in muscle and sometimes in subcutis, but never in skin, with the greatest hyperalgesic effects in left abdominis muscle. Abdominal sites were more vulnerable to menstrual influences than limb sites. Muscle thresholds, but not skin or subcutis thresholds, were significantly lower in abdomen than in limbs, particularly in dysmenorrheic women. The amount of abdominal muscle hyperalgesia correlated significantly with the amount of spontaneous menstrual pain. Only minor sex differences were observed for pain thresholds of the arm and leg, but there was a unanimous refusal by men, but not by women, to be tested at abdominal sites. These results indicate that menstrual phase, dysmenorrhea status, segmental site, tissue depth and sex all have unique interacting effects on pain thresholds, thus adding more items to the lengthy and still-growing list of biological factors that enter into an individual's judgment of whether or not a stimulus is painful.


Assuntos
Dismenorreia/fisiopatologia , Ciclo Menstrual/fisiologia , Limiar da Dor/fisiologia , Músculos Abdominais , Adulto , Dismenorreia/psicologia , Estimulação Elétrica , Feminino , Humanos , Masculino , Medição da Dor , Caracteres Sexuais
7.
Brain Res ; 774(1-2): 234-8, 1997 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-9452216

RESUMO

This study examined estrous differences in the characteristics of behavioral crises of visceral pain in female rats video-taped throughout a 4-day period after implantation of an artificial stone in one ureter. All animals continued to have a regular cycle after ureteral surgery. In the recording period, the percentage of time spent in crises was significantly higher during metestrus/diestrus (M/D) than during proestrus/estrus (P/E) (P < 0.001, chi2-test). Mean duration and complexity of crises were slightly higher in M/D than in P/E, but the difference was not significant. The results in this animal model show an enhancement of ureteral pain sensitivity in M/D, a finding in line with the clinical observation, in fertile women with urinary calculosis, of a greater incidence of colics in the perimenstrual period (equivalent to M/D in rats).


Assuntos
Estro/fisiologia , Dor/fisiopatologia , Cálculos Ureterais/fisiopatologia , Vísceras/fisiopatologia , Animais , Diestro/fisiologia , Feminino , Metestro/fisiologia , Proestro/fisiologia , Ratos , Ratos Sprague-Dawley
8.
Eur J Pharmacol ; 278(2): 97-101, 1995 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-7672006

RESUMO

Rats with artificial calculosis of one ureter develop hyperalgesia in the ipsilateral oblique musculature as evidenced by decreased vocalization threshold to electrical muscle stimulation lasting over a week. The aim of the study was to evaluate the effect on this hyperalgesia of spasmolytic anticholinergic and/or non-steroidal antiinflammatory drugs, common therapies for colic pain in humans. Rats implanted with a unilateral ureteral stone were treated for 10 days with: (1) saline; (2) hyoscine-N-butylbromide (15 mg/kg/day i.p.); (3) ketoprofen (15 mg/kg/day); or (4) hyoscine-N-butylbromide + ketoprofen (15 + 15 mg/kg/day). Oblique muscle vocalization thresholds were measured daily for 3 days before and 10 days after operation. Ipsilateral thresholds decreased significantly after stone implantation on: (1) seven days (max. 32%) for saline; (2) one day (max. 20%) for hyoscine-N-butylbromide; (3) one day (max. 18%) for ketoprofen, but did not change significantly for hyoscine-N-butylbromide + ketoprofen. These results indicate a protective effect against muscle hyperalgesia of ureteral origin by spasmolytic and antiinflammatory drugs, maximal when the two treatments are combined.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Hiperalgesia/tratamento farmacológico , Hiperalgesia/etiologia , Doenças Musculares/tratamento farmacológico , Doenças Musculares/etiologia , Parassimpatolíticos/uso terapêutico , Doenças Ureterais/complicações , Animais , Brometo de Butilescopolamônio/uso terapêutico , Estimulação Elétrica , Feminino , Hiperalgesia/patologia , Cetoprofeno/uso terapêutico , Doenças Musculares/patologia , Medição da Dor/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Doenças Ureterais/patologia
9.
Neurosci Lett ; 208(2): 117-20, 1996 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-8859904

RESUMO

Patients with chronic fatigue syndrome (CFS) mainly complain of symptoms in the musculoskeletal domain (myalgias, fatigue). In 21 CFS patients the deep (muscle) versus superficial (skin, subcutis) sensitivity to pain was explored by measuring pain thresholds to electrical stimulation unilaterally in the deltoid, trapezius and quadriceps and overlying skin and subcutis in comparison with normal subjects. Thresholds in patients were normal in skin and subcutis but significantly lower than normal (hyperalgesia) in muscles (P < 0.001) in all sites. The selective muscle hypersensitivity corresponded also to fiber abnormalities at muscle biopsy (quadriceps) performed in nine patients which were absent in normal subjects (four cases): morphostructural alterations of the sarchomere, fatty degeneration and fibrous regeneration, inversion of the cytochrome oxidase/succinate dehydrogenase ratio, pleio/polymorphism and monstruosity of mitochondria, reduction of some mitochondrial enzymatic activities and increments of common deletion of 4977 bp of mitochondrial DNA 150-3000 times the normal values. By showing both sensory (diffuse hyperalgesia) and anatomical (degenerative picture) changes at muscle level, the results suggest a role played by peripberal mechanisms in the genesis of CFS symptoms. They would exclude the heightened perception of physiological signals from all districts hypothesized by some authors, especially as the hyperalgesia is absent in skin/subcutis.


Assuntos
Síndrome de Fadiga Crônica/fisiopatologia , Limiar da Dor/fisiologia , Lobo Parietal/fisiologia , Córtex Somatossensorial/fisiologia , Adulto , Biópsia , Estimulação Elétrica , Feminino , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Músculo Esquelético/inervação , Músculo Esquelético/patologia , Músculo Esquelético/ultraestrutura , Pele/inervação
10.
Drugs Exp Clin Res ; 27(2): 69-76, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11392056

RESUMO

The aim of this study was to determine whether topical application of diclofenac hydroxyethylpyrrolidine (DHEP) modifies somatic pain sensitivity in subjects without spontaneous pain. Twenty male subjects (aged 19-40 years), who had not reported any pain for at least 1 month, underwent measurement of pain thresholds to bilateral electrical stimulation in the quadriceps muscle and overlying subcutis and skin. Following the double-blind study design, one diclofenac adhesive plaster (13 x 10 cm; 180 mg DHEP) was then applied over one quadriceps while a matched placebo plaster was placed contralaterally. Each subject was given two other plasters (diclofenac and placebo) and instructed to substitute those over the quadriceps after 12 h and to wear them for a further 12 h. Thirty minutes after removal of the second plasters, thresholds. were remeasured in all subjects as on the previous day. Thresholds at the first evaluation were within normal range in nine subjects (group 1) and below normal in muscle (hyperalgesia) in the remaining 11 (group 2). No significant changes were observed in skin or subcutis thresholds after diclofenac or placebo treatment in either group. In contrast, muscle thresholds significantly increased after diclofenac compared with placebo treatment (group 1: p < 0.05; group 2: p < 0.007); the increase was significantly higher in group 2 than in group 1 (p < 0.002). Topical application of diclofenac had a selective hypoalgesic effect on muscles, which was more pronounced in the case of hyperalgesia. These results suggest that the preparation is particularly effective in the treatment of algogenic conditions of deep somatic tissues.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Diclofenaco/farmacologia , Limiar da Dor/efeitos dos fármacos , Administração Tópica , Adolescente , Adulto , Diclofenaco/administração & dosagem , Método Duplo-Cego , Humanos , Masculino , Músculo Esquelético/efeitos dos fármacos , Pele/efeitos dos fármacos
11.
Cell Death Dis ; 5: e1414, 2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-25210797

RESUMO

Che-1/AATF is an RNA polymerase II-binding protein that is involved in the regulation of gene transcription, which undergoes stabilization and accumulation in response to DNA damage. We have previously demonstrated that following apoptotic induction, Che-1 protein levels are downregulated through its interaction with the E3 ligase HDM2, which leads to Che-1 degradation by ubiquitylation. This interaction is mediated by Pin1, which determines a phosphorylation-dependent conformational change. Here we demonstrate that HIPK2, a proapoptotic kinase, is involved in Che-1 degradation. HIPK2 interacts with Che-1 and, upon genotoxic stress, phosphorylates it at specific residues. This event strongly increases HDM2/Che-1 interaction and degradation of Che-1 protein via ubiquitin-dependent proteasomal system. In agreement with these findings, we found that HIPK2 depletion strongly decreases Che-1 ubiquitylation and degradation. Notably, Che-1 overexpression strongly counteracts HIPK2-induced apoptosis. Our results establish Che-1 as a new HIPK2 target and confirm its important role in the cellular response to DNA damage.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Proteínas de Transporte/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Reguladoras de Apoptose/genética , Proteínas de Transporte/genética , Dano ao DNA , Humanos , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteólise , Proteínas Repressoras/genética , Ubiquitina/metabolismo , Ubiquitinação
12.
Artigo em Inglês | MEDLINE | ID: mdl-21337234

RESUMO

Triclabendazole (TCBZ) is a flukicidal halogenated benzimidazole compound extensively used in veterinary medicine. Liver fluke control in lactating dairy cattle is difficult because treatment should be implemented only during the dry period to avoid milk residues. However, control in endemic areas is usually implemented as regular treatments three to four times a year, even during the lactating period. Thus, information on TCBZ milk excretion and the risk of the presence of drug residues in fluid milk and milk-derivate products is essential. The experimental aims were to evaluate the comparative disposition kinetics of TCBZ and its sulpho-metabolites in plasma and milk in lactating dairy cattle after the oral administration (12 mg kg(-1)) of TCBZ and to assess the pattern of residues in cheese made with milk from treated dairy cows. Both TCBZ sulphoxide and sulphone metabolites but not TCBZ were detected in milk (up to 36 and 144 h, respectively) and plasma (up to 144 h) after oral administration of TCBZ. Residual concentrations of TCBZ sulpho-metabolites were found in cheese made with milk from treated animals. The total average residual concentration in fresh cheese was 13.0-fold higher than that obtained in milk used for its elaboration. The high concentrations of TCBZ sulpho-metabolites recovered in fresh cheese should be seriously considered before milk from treated cows is used for making dairy products.


Assuntos
Anti-Helmínticos/análise , Benzimidazóis/análise , Bovinos/metabolismo , Queijo/análise , Resíduos de Drogas/análise , Leite/química , Drogas Veterinárias/análise , Animais , Anti-Helmínticos/sangue , Anti-Helmínticos/farmacocinética , Benzimidazóis/sangue , Benzimidazóis/farmacocinética , Biotransformação , Cromatografia Líquida de Alta Pressão/veterinária , Feminino , Contaminação de Alimentos , Meia-Vida , Lactação , Limite de Detecção , Reprodutibilidade dos Testes , Sulfonas/análise , Sulfóxidos/análise , Distribuição Tecidual , Triclabendazol , Drogas Veterinárias/sangue , Drogas Veterinárias/farmacocinética
13.
Radiat Prot Dosimetry ; 137(3-4): 306-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19889799

RESUMO

In 2004, contaminated water was found inside the safety interspace around the spent fuel pool; therefore, an ample monitoring programme of the structure, soils and shallow groundwater was started in order to detect any radioactive leakage into the environment. A first group of piezometers was installed. In the one nearest to the pool, an anomalous activity of (90)Sr ( approximately 10(-2) Bq l(-1)) was found, calling for the following actions: gradual enlarging of the monitoring network, implementation of in situ permeability tests and groundwater tracer test and study of groundwater mobility of the main radionuclides contained in the pool water: (90)Sr, (137)Cs, (241)Am and (239/240)Pu. Because (90)Sr is the only artificial radionuclide detected in groundwater, this study mainly focused on this one. All the investigations demonstrated that (90)Sr coming from the pool is not detectable any longer just some tens of metres from the building and allow the correlation of (90)Sr concentration to flow and water-table fluctuations. Moreover, such a wide mass of hydrogeological and radiological data allows the estimation of an environmental value for environmental radiological significance.


Assuntos
Centrais Nucleares , Monitoramento de Radiação/métodos , Proteção Radiológica/métodos , Resíduos Radioativos , Radioisótopos/análise , Poluentes Radioativos da Água/análise , Geologia/métodos , Itália , Doses de Radiação
14.
FASEB J ; 14(7): 904-12, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10783144

RESUMO

hRPB11 is a core subunit of RNA polymerase II (pol II) specifically down-regulated on doxorubicin (dox) treatment. Levels of this protein profoundly affect cell differentiation, cell proliferation, and tumorigenicity in vivo. Here we describe Che-1, a novel human protein that interacts with hRPB11. Che-1 possesses a domain of high homology with Escherichia coli RNA polymerase final sigma-factor 70 and SV40 large T antigen. In addition, we report that Che-1 interacts with the retinoblastoma susceptibility gene (Rb) by two distinct domains. Functionally, we demonstrate that Che-1 represses the growth suppression function of Rb, counteracting the inhibitory action of Rb on the trans-activation function of E2F1. These results identify a novel protein that binds Rb and the core of pol II, and suggest that Che-1 may be part of transcription regulatory complex.


Assuntos
Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , RNA Polimerase II/metabolismo , Proteína do Retinoblastoma/metabolismo , Sequência de Aminoácidos , Ciclo Celular/fisiologia , Divisão Celular/fisiologia , Linhagem Celular , Clonagem Molecular , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Humanos , Dados de Sequência Molecular , Ligação Proteica , RNA Polimerase II/química , Proteína do Retinoblastoma/antagonistas & inibidores , Proteína do Retinoblastoma/fisiologia , Proteína 1 de Ligação ao Retinoblastoma , Homologia de Sequência de Aminoácidos , Fator de Transcrição DP1 , Fatores de Transcrição/metabolismo
15.
Mol Cell ; 8(4): 885-97, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11684023

RESUMO

We describe a functional and biochemical link between the myogenic activator MyoD, the deacetylase HDAC1, and the tumor suppressor pRb. Interaction of MyoD with HDAC1 in undifferentiated myoblasts mediates repression of muscle-specific gene expression. Prodifferentiation cues, mimicked by serum removal, induce both downregulation of HDAC1 protein and pRb hypophosphorylation. Dephosphorylation of pRb promotes the formation of pRb-HDAC1 complex in differentiated myotubes. pRb-HDAC1 association coincides with disassembling of MyoD-HDAC1 complex, transcriptional activation of muscle-restricted genes, and cellular differentiation of skeletal myoblasts. A single point mutation introduced in the HDAC1 binding domain of pRb compromises its ability to disrupt MyoD-HDAC1 interaction and to promote muscle gene expression. These results suggest that reduced expression of HDAC1 accompanied by its redistribution in alternative nuclear protein complexes is critical for terminal differentiation of skeletal muscle cells.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Histona Desacetilases/metabolismo , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/crescimento & desenvolvimento , Proteína MyoD/metabolismo , Proteína do Retinoblastoma/metabolismo , Animais , Diferenciação Celular/fisiologia , Linhagem Celular , Meios de Cultura Livres de Soro , Proteínas de Ligação a DNA/metabolismo , Genes Reporter , Histona Desacetilase 1 , Histona Desacetilases/genética , Fatores de Transcrição MEF2 , Microscopia de Fluorescência , Modelos Biológicos , Músculo Esquelético/citologia , Músculo Esquelético/fisiologia , Proteína MyoD/genética , Fatores de Regulação Miogênica , Fosforilação , Testes de Precipitina , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteína do Retinoblastoma/genética , Fatores de Transcrição/metabolismo
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