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1.
Clin Exp Rheumatol ; 32(6 Suppl 86): S-167-70, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25189168

RESUMO

OBJECTIVES: High-resolution MR angiography (HR-MRA) demonstrates blood flow in the digital arteries, which correlates with the severity of Raynaud's phenomenon (RP). This study investigates whether baseline HR-MRA of the hand can predict the treatment response to udenafil, a new PDE5-inhibitor, in patients with secondary RP. METHODS: Baseline MRA and Doppler ultrasound were obtained in 12 patients with secondary RP. The patients were treated with udenafil 100 mg/day for 4 weeks and changes in blood flow were measured. Blood flow on MRA was scored on a 4-point scale: 0, no visible flow; 1, visible flow to the proximal phalanx; 2, to the middle phalanx; and 3, to the distal phalanx. Peak systolic velocity (PSV) was measured to determine blood flow. Paired t-test and ANOVA were used to determine the treatment response of the different MRA scores. RESULTS: On baseline MRA, 53.3% of digital arteries had an MRA score of 0, 25.8% MRA score of 1, 9.2% MRA score of 2, and 11.6% MRA score of 3. Overall, 4-week udenafil treatment improved digital flow (p<0.05) in all MRA scores. Digital arteries with MRA score 2 showed the best response with improvement in PSV by 14.5 mm/sec (p<0.01), whereas improvement in arteries of MRA scores 1 and 3 were not better than an MRA score of 0 (all, p>0.05). CONCLUSIONS: Digital arteries with moderate blood flow observed on MRA respond best to treatment with udenalfil. Therefore, baseline MRA may help predict treatment response in patients with secondary RP.


Assuntos
Dedos/irrigação sanguínea , Angiografia por Ressonância Magnética , Inibidores da Fosfodiesterase 5/uso terapêutico , Pirimidinas/uso terapêutico , Doença de Raynaud/tratamento farmacológico , Fluxo Sanguíneo Regional , Sulfonamidas/uso terapêutico , Adulto , Estudos de Coortes , Doenças do Tecido Conjuntivo/complicações , Feminino , Dedos/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Doença de Raynaud/diagnóstico , Doença de Raynaud/etiologia , Resultado do Tratamento , Ultrassonografia
2.
Gene Ther ; 20(7): 717-22, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23151518

RESUMO

The purpose of this phase I clinical trial was to evaluate the safety, tolerability and potential efficacy of VM202, naked DNA expressing two isoforms of hepatocyte growth factor, as an adjunct therapy to coronary artery bypass grafting (CABG) in patients with ischemic heart disease (IHD). Nine patients were assigned to receive increasing doses (0.5 to 2.0 mg) of VM202 injected into the right coronary artery (RCA) territory following completion of CABG for the left coronary artery territory. Patients were evaluated for safety and tolerability, and changes in myocardial functions were monitored via echocardiography, cardiac magnetic resonance imaging and myocardial single photon emission computed tomography throughout 6-month follow-up period. No serious complication related to VM202 was observed throughout the 6-month follow-up period. Global myocardial functions (wall motion score index, P=0.0084; stress perfusion, P=0.0002) improved during the follow-up period. In the RCA region, there was an increase in the stress perfusion (baseline vs 3-month, P=0.024; baseline vs 6-month, P=0.024) and also in the wall thickness of the diastolic and systolic phases. Intramyocardial injection of VM202 can be safely used in IHD patients with the tolerable dose of 2.0 mg. In addition, VM202 might appear to have improved regional myocardial perfusion and wall thickness in the injected region.


Assuntos
Ponte de Artéria Coronária , Técnicas de Transferência de Genes , Coração/diagnóstico por imagem , Fator de Crescimento de Hepatócito/genética , Isquemia Miocárdica/terapia , Vacinas de DNA/administração & dosagem , Idoso , Feminino , Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/genética , Isquemia Miocárdica/cirurgia , Miocárdio , Neovascularização Fisiológica/genética , Radiografia , Tomografia Computadorizada de Emissão de Fóton Único , Vacinas de DNA/genética
3.
Phlebology ; 27(5): 235-41, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22037280

RESUMO

OBJECTIVE: To define the anatomical variations of small saphenous vein (SSV) for varicose vein (VV) surgery by three-dimensional computed tomography venography (3D-CTV) and to analyse the impact of this preoperative evaluation on surgical outcomes. METHODS: A total of 120 consecutive limbs with SSV insufficiency having undergone VV surgery from January 2005 until December 2007 were enrolled. The medical records and images were analysed retrospectively. RESULTS: The relationship between SSV and gastrocnemial vein (GNV) were categorized into two: (a) SSV and GNV drained to popliteal vein (PV) separately (100 limbs, 87%) and (b) SSV and GNV made common channel which drained to PV (15 limbs, 13%). Saphenopopliteal junction morphology was normal (75 limbs), severe tortuosity near PV (19 limbs), ampullary ectasia (4 limbs) and duplicated drainage to PV (2 limbs). No recurrence of VV was noted. CONCLUSIONS: CTV can provide thorough preoperative anatomic information of the SSV variations and reduce the recurrence of VV.


Assuntos
Imageamento Tridimensional , Angiografia por Ressonância Magnética , Veia Safena/diagnóstico por imagem , Varizes/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Radiografia , Estudos Retrospectivos , Veia Safena/cirurgia , Varizes/cirurgia
4.
Mini Rev Med Chem ; 9(3): 329-39, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19275726

RESUMO

The heptahelical G protein coupling receptors oligomerize extensively via transmembrane domains, in association with heterotrimeric G proteins. This provides higher affinity for agonists, conformational stability necessary for signal transduction, and protection from intracellular proteinases. The oligomerization is relevant to organismic pathophysiology and could be targeted by natural or modified agonists.


Assuntos
Multimerização Proteica , Estrutura Quaternária de Proteína , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Animais , Humanos , Domínios e Motivos de Interação entre Proteínas/fisiologia , Subunidades Proteicas/química , Subunidades Proteicas/fisiologia , Transdução de Sinais/fisiologia
5.
Clin Radiol ; 64(2): 127-32, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19103341

RESUMO

AIM: To evaluate the differences in the characterization and recommendation for follow-up of subcentimetre solitary pulmonary nodules (SSPNs) between 5 and 1mm section CT, and to compare the assessments generated by four radiologists MATERIALS AND METHODS: Five hundred and twenty-nine patients who had SSPNs on chest CT reconstructed using both 5 and 1mm sections were enrolled. Two image subsets of 5 and 1mm CT images of each nodule were interpreted independently by four radiologists. Nodule size, consistency (solid, partly solid, non-solid), the presence of calcification, and recommendations for follow-up were evaluated. If a non-calcified solid nodule was confirmed using CT, recommendation for follow-up was based on Fleischner Society guidelines. Data assessed by each radiologist were compared, and interobserver agreements were determined using the intraclass correlation coefficients and kappa value. RESULTS: Using 1mm CT images, the nodule sizes were significantly larger than on 5mm CT images (paired t-test, p<0.01). The presence of calcification and nodule consistency were significantly different between 5 and 1mm CT images (McNemar test for the presence of calcification, p<0.01; Wilcoxon signed test for nodule consistency, p<0.01). On 1mm CT images there was significantly higher agreement regarding nodule consistency than on 5mm CT (kappa=0.78 and 0.67, respectively). CONCLUSIONS: Concurrent use of thin-section and thick-section CT can provide more accurate nodule assessment and higher interobserver agreement in SSPN.


Assuntos
Nódulo Pulmonar Solitário/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Calcinose/diagnóstico por imagem , Calcinose/patologia , Feminino , Humanos , Assistência de Longa Duração , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Nódulo Pulmonar Solitário/patologia , Tomografia Computadorizada por Raios X/métodos
6.
J Parasitol ; 95(3): 768-71, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19071966

RESUMO

Parasitological examination of samples from tombs of the Korean Joseon Dynasty (1392-1910) could be helpful to researchers in understanding parasitic infection prevalence in pre-industrial Korean society. Whereas most of our previous parasitological studies revealed the presence of ancient parasite eggs in coprolites of Korean mummies, a sample from a man living in late 17th century Korea proved to be relatively unique in possessing what appeared to be several species of parasite larvae. The larvae identified included Strongyloides stercoralis and Trichostrongylus spp., along with eggs of Ascaris lumbricoides, Trichuris trichiura, and Paragonimus westermani. Since ancient parasite larvae retain enough morphology to make proper species identification possible, even after long burial times, the examination of parasite larvae within ancient samples will be conducted more carefully in our future work.


Assuntos
Múmias/parasitologia , Estrongiloidíase/história , Tricostrongilose/história , Animais , Fezes/parasitologia , História do Século XVII , Humanos , Coreia (Geográfico) , Larva/classificação , Masculino , Óvulo/classificação , Strongyloides stercoralis/classificação , Strongyloides stercoralis/isolamento & purificação , Trichostrongylus/classificação , Trichostrongylus/isolamento & purificação
7.
J Recept Signal Transduct Res ; 28(5): 437-51, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18946765

RESUMO

In conditions precluding activation of G proteins, the binding of agonists to dimers of the neuropeptide Y (NPY) Y2 receptor shows two components of similar size, but differing in affinity. The dimers of all NPY receptors are solubilized as approximately 180-kDa complexes containing one G protein alpha beta gamma trimer. These heteropentamers are stable to excess agonists, chelators, and alkylators. However, dispersion in the weak surfactant cholate releases approximately 300-kDa complexes. These findings indicate that both protomers in the Y2 dimer are associated with G protein heterotrimers, but the extent of interaction depends on affinity for the agonist peptide. The G protein in contact with the first-liganded, higher-affinity protomer should have a stronger interaction with the receptor and a larger probability of activation.


Assuntos
Proteínas de Ligação ao GTP/agonistas , Proteínas de Ligação ao GTP/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Estrenos/farmacologia , Guanosina 5'-O-(3-Tiotrifosfato)/farmacologia , Humanos , Camundongos , Inibidores de Fosfodiesterase/farmacologia , Multimerização Proteica , Pirrolidinonas/farmacologia , Coelhos , Receptores de Neuropeptídeo Y/química
8.
J Recept Signal Transduct Res ; 28(3): 245-63, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18569526

RESUMO

The neuropeptide Y(NPY) Y2 receptors are detected largely as dimers in the clonal expressions in CHO cells and in particulates from rabbit kidney cortex. However, in two areas of the forebrain (rat or rabbit piriform cortex and hypothalamus), these receptors are found mainly as monomers. Evidence is presented that this difference relates to large levels of G proteins containing the Gi alpha -subunit in the forebrain areas. The predominant monomeric status of these Y2 receptors should also be physiologically linked to large synaptic inputs of the agonist NPY. The rabbit kidney and the human CHO cell-expressed Y2 dimers are converted by agonists to monomers in vitro at a similar rate in the presence of divalent cations.


Assuntos
Rim/metabolismo , Prosencéfalo/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Animais , Células CHO , Cátions Bivalentes/farmacologia , Cricetinae , Cricetulus , Dimerização , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Masculino , Ligação Proteica/efeitos dos fármacos , Coelhos , Ratos , Receptores de Neuropeptídeo Y/agonistas , Transdução de Sinais/efeitos dos fármacos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo
9.
J Hum Hypertens ; 21(11): 868-74, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17476289

RESUMO

Size at birth and early postnatal growth rates appear to be important determinants of cardiovascular diseases. We examined whether intrauterine growth restriction or the subsequent catch-up postnatal weight gain leads to higher blood pressure in early life to confirm that size at birth and early postnatal growth rates appear to be important determinants of blood pressure changes in early life. Of 407 children born between December 2001 and November 2002 in hospital based-birth cohorts, 102 were followed up at 3 years of age (24.2%) at Ewha Womans University Hospital in Seoul, Korea. At 3 years of age, those who had a low birth weight still belonged in the lower-weight group than the others. The subjects' systolic blood pressure was correlated with their current weight (r=0.41) and weight gain (r=0.39), but not with their birth weight. Those with a higher current weight and higher weight gain based on birth weight (conditional weight gain) had the highest blood pressure. Systolic blood pressure increased by 0.2 mm Hg for every 100-g increase in weight at 3 years and, independently, by 1.5 mm Hg for every 100-unit increase in conditional weight gain. This study suggests that birth weight is not directly associated with blood pressure, but accelerated growth, which occurs mostly in those born with a low birth weight, seems to affect blood pressure in early life.


Assuntos
Peso ao Nascer , Pressão Sanguínea , Crescimento , Índice de Massa Corporal , Doenças Cardiovasculares/etiologia , Pré-Escolar , Feminino , Seguimentos , Humanos , Recém-Nascido , Masculino , Análise de Regressão , Aumento de Peso
10.
Eur J Clin Nutr ; 58(10): 1365-71, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15054416

RESUMO

OBJECTIVE: It has been known that maternal oxidative stress during pregnancy plays an important role in fetal growth. However, the association between antioxidant vitamin levels and birth outcomes is not conclusive. We investigated the relationship between maternal serum levels of vitamins C and E during the second trimester and birth weight and length. DESIGN: Prospective cohort study. SETTING: Outpatient-clinic of obstetrics, Ewha Womans University Hospital, South Korea. SUBJECTS AND METHODS: The study subjects were 239 healthy, pregnant women who visited an obstetric clinic for antenatal care, and their singleton live births, in Seoul, Korea, between August 2001 and March 2003. We measured the levels of vitamins C and E in maternal serum during the period 24-28 gestational weeks. Each woman was interviewed for dietary intake by trained interviewers during the second trimester. RESULTS: The serum concentration of maternal vitamin C during the second trimester was significantly associated with birth weight and length in the group of full-term deliveries. An increase of 1 microg/ml in the serum vitamin C level increased the birth weight by 27.2 g and the birth length by 0.17 cm. When we considered the levels of vitamins C and E together in the relationship with birth weight and length, we found that the heaviest birth weight and the longest birth length belonged to the group of upper vitamin C/upper vitamin E. However, dietary intake estimated by 24-h recall method was not a predictor of the levels of serum vitamins C and E. CONCLUSION: We found that maternal serum vitamin C levels during the second trimester were positively correlated with birth weight and length in full-term babies. We also found that birth weight and length were highest when the levels of both vitamins C and E were high. Our results indicate the importance of antioxidant nutrient balance for pregnant women who are exposed to various oxidants through food, drinking water, or inhaled air.


Assuntos
Ácido Ascórbico/sangue , Peso ao Nascer , Estatura , Desenvolvimento Fetal/efeitos dos fármacos , Segundo Trimestre da Gravidez/sangue , Vitamina E/sangue , Antioxidantes/administração & dosagem , Antioxidantes/análise , Ácido Ascórbico/administração & dosagem , Peso ao Nascer/efeitos dos fármacos , Estatura/efeitos dos fármacos , Estudos de Coortes , Dieta , Sinergismo Farmacológico , Feminino , Humanos , Recém-Nascido , Masculino , Troca Materno-Fetal , Rememoração Mental , Gravidez , Resultado da Gravidez , Estudos Prospectivos , Vitamina E/administração & dosagem
11.
J Korean Med Sci ; 16(1): 127-9, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11289392

RESUMO

Infantile hemangioendothelioma is a severe disease with a high mortality. It is characterized by multiple hemangioma affecting the skin and visceral organs. We report that high doses of methylprednisolone pulse therapy improved symptoms and signs of infantile hemangioendothelioma in a male neonate, and completely resolved the hepatic and cutaneous hemangioendothelioma on follow up.


Assuntos
Hemangioendotelioma/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Metilprednisolona/administração & dosagem , Neoplasias Cutâneas/tratamento farmacológico , Humanos , Recém-Nascido , Masculino
12.
Biochem J ; 354(Pt 1): 189-97, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11171094

RESUMO

Liver carnitine palmitoyltransferase I (L-CPT I) catalyses the transfer of long-chain fatty acid (LCFA) for translocation across the mitochondrial membrane. Expression of the L-CPT I gene is induced by LCFAs as well as by lipid-lowering compounds such as clofibrate. Previous studies have suggested that the peroxisome-proliferator-activated receptor alpha (PPARalpha) is a common mediator of the transcriptional effects of LCFA and clofibrate. We found that free LCFAs rather than acyl-CoA esters are the signal metabolites responsible for the stimulation of L-CPT I gene expression. Using primary culture of hepatocytes we found that LCFAs failed to stimulate L-CPT I gene expression both in wild-type and PPARalpha-null mice. These results suggest that the PPARalpha-knockout mouse does not represent a suitable model for the regulation of L-CPT I gene expression by LCFAs in the liver. Finally, we determined that clofibrate stimulates L-CPT I through a classical direct repeat 1 (DR1) motif in the promoter of the L-CPT I gene while LCFAs induce L-CPT I via elements in the first intron of the gene. Our results demonstrate that LCFAs can regulate gene expression through PPARalpha-independent pathways and suggest that the regulation of gene expression by dietary lipids is more complex than previously proposed.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Ácidos Graxos/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Fígado/enzimologia , Receptores Citoplasmáticos e Nucleares/fisiologia , Fatores de Transcrição/fisiologia , Animais , Sequência de Bases , Células Cultivadas , Clofibrato/farmacologia , Primers do DNA , Inibidores Enzimáticos/farmacologia , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores Citoplasmáticos e Nucleares/genética , Fatores de Transcrição/genética , Células Tumorais Cultivadas
13.
J Mol Cell Cardiol ; 33(2): 317-29, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11162136

RESUMO

Carnitine palmitoyltransferase-I (CPT-I) is a major control point for fatty acid oxidation. Two kinetically different isoforms, CPT-I alpha and CPT-I beta, have been identified. Cardiac ventricular myocytes are the only cells known to express both CPT-I isoforms. In this study, we characterized the differential regulation of CPT-I alpha and CPT-I beta expression in the heart. Expression of the CPT-I alpha gene was very high in the fetal heart and declined following birth. CPT-I beta was also highly expressed in fetal myocytes and remained so throughout development. CPT-I alpha mRNA abundance was increased in both the liver and heart of diabetic or fasted rats, but CPT-I beta mRNA levels were not altered in these states. A high fat diet elevated expression of the CPT-I alpha gene in the liver but not in the heart. The fat content of the diet did not affect the expression of CPT-I beta. Cultures of neonatal rat cardiac myocytes were transfected with luciferase reporter genes driven by CPT-I alpha or CPT-I beta promoters. Two regions of the CPT-I alpha promoter, including an upstream region (-1300/-960) and a region in the proximal promoter (-193/-52) contributed equally to basal expression in cardiac myocytes. Basal transcription of CPT-I alpha was dependent on Sp1 sites and a CCAAT box in the proximal promoter. Our data indicate that the CPT-I beta gene is expressed in a tissue specific manner, but that it is not subject to the same developmental or hormonal controls imposed on CPT-I alpha. In addition some aspects of CPT-I alpha expression are confined to the liver. The data presented here thus suggest that two types of differential regulation of CPT-I genes exist: (a) differential control of CPT-I alpha and CPT-I beta gene expression in the heart and (b) differential regulation of CPT-I alpha expression in the heart and liver.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Regulação Enzimológica da Expressão Gênica , Miocárdio/enzimologia , Fatores Etários , Animais , Sítios de Ligação , Carcinoma Hepatocelular/metabolismo , Carnitina O-Palmitoiltransferase/química , Núcleo Celular/metabolismo , Células Cultivadas , Diabetes Mellitus Experimental/enzimologia , Gorduras na Dieta/farmacologia , Ácidos Graxos/metabolismo , Feminino , Genes Reporter , Vetores Genéticos , Coração/embriologia , Hipertireoidismo/enzimologia , Cinética , Fígado/enzimologia , Neoplasias Hepáticas/metabolismo , Luciferases/metabolismo , Masculino , Miocárdio/citologia , Regiões Promotoras Genéticas , Isoformas de Proteínas , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Transcrição Sp1/genética , Fatores de Tempo , Distribuição Tecidual , Transfecção , Células Tumorais Cultivadas
14.
J Biol Chem ; 275(45): 34989-97, 2000 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-10956641

RESUMO

Carnitine palmitoyltransferase I (CPT-I) catalyzes the transfer of long chain fatty acyl groups from CoA to carnitine for translocation across the mitochondrial inner membrane. CPT-Ialpha is a key regulatory enzyme in the oxidation of fatty acids in the liver. CPT-Ialpha is expressed in all tissues except skeletal muscle and adipose tissue, which express CPT-Ibeta. Expression of CPT-Ialpha mRNA and enzyme activity are elevated in the liver in hyperthyroidism, fasting, and diabetes. CPT-Ialpha mRNA abundance is increased 40-fold in the liver of hyperthyroid compared with hypothyroid rats. Here, we examine the mechanisms by which thyroid hormone (T3) stimulates CPT-Ialpha gene expression. Four potential T3 response elements (TRE), which contain direct repeats separated by four nucleotides, are located 3000-4000 base pairs 5' to the start site of transcription in the CPT-Ialpha gene. However, only one of these elements functions as a TRE. This TRE binds the T3 receptor as well as other nuclear proteins. Surprisingly, the first intron of the CPT-Ialpha gene is required for the T3 induction of CPT-Ialpha expression, but this region of the gene does not contain a TRE. In addition, we show that CPT-Ialpha is induced by T3 in cell lines of hepatic origin but not in nonhepatic cell lines.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Carnitina O-Palmitoiltransferase/metabolismo , Regulação Enzimológica da Expressão Gênica , Íntrons , Regiões Promotoras Genéticas , Hormônios Tireóideos/metabolismo , Sequência de Aminoácidos , Animais , Animais Recém-Nascidos , Linhagem Celular , Núcleo Celular/metabolismo , Células Cultivadas , Desoxirribonuclease I/metabolismo , Escherichia coli/metabolismo , Ácidos Graxos/metabolismo , Humanos , Fígado/enzimologia , Luciferases/metabolismo , Modelos Genéticos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Miocárdio/metabolismo , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Ratos , Proteínas Recombinantes/metabolismo , Elementos de Resposta , Análise de Sequência de DNA , Transfecção , Tri-Iodotironina/metabolismo
15.
Am J Med Sci ; 318(1): 43-8, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10408760

RESUMO

Two genes control expression of mitochondrial carnitine palmitoyltransferase-I (CPT-I), the enzyme that catalyzes the primary rate-controlling step in fatty acid oxidation. Two CPT-I isoforms have been found--a "liver" isoform (CPT-Ialpha) expressed in most tissues, but not in skeletal muscles, and a "muscle" isoform (CPT-Ibeta) expressed in muscles and adipocytes. Liver CPT-Ialpha increases dramatically at birth, but heart CPT-Ialpha is abundant in the fetus and diminishes at birth. Insulin, thyroid hormone, and fatty acids regulate expression of CPT-Ialpha in liver, whereas electrical stimulation increases CPT-Ibeta and decreases CPT-Ialpha in cardiac myocytes. Both genes are TATA-less and contain Sp1 transcription factor binding sites upstream of the start site of transcription. Multiple transcripts of both CPT-Ialpha and CPT-Ibeta exist, some of which may have roles in regulating fatty acid oxidation.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Ácidos Graxos/metabolismo , Regulação Enzimológica da Expressão Gênica , Mitocôndrias/enzimologia , Animais , Humanos , Isoenzimas/genética , Mitocôndrias Cardíacas/enzimologia , Mitocôndrias Hepáticas/enzimologia , Oxirredução
16.
Biochem J ; 340 ( Pt 2): 425-32, 1999 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10333485

RESUMO

Carnitine palmitoyltransferase (CPT)-I catalyses the transfer of long-chain fatty acids from CoA to carnitine for translocation across the mitochondrial inner membrane. Expression of the 'liver' isoform of the CPT-I gene (CPT-Ialpha) is subject to developmental, hormonal and tissue-specific regulation. To understand the basis for control of CPT-Ialpha gene expression, we have characterized the proximal promoter of the CPT-Ialpha gene. Here, we report the sequence of 6839 base pairs of the promoter and the localization of the rat CPT-Ialpha gene to region q43 on chromosome 1. Our studies show that the first 200 base pairs of the promoter are sufficient to drive transcription of the CPT-Ialpha gene. Within this region are two sites that bind both Sp1 and Sp3 transcription factors. In addition, nuclear factor Y (NF-Y) binds the proximal promoter. Mutation at the Sp1 or NF-Y sites severely decreases transcription from the CPT-Ialpha promoter. Other protein binding sites were identified within the first 200 base pairs of the promoter by DNase I footprinting, and these elements contribute to CPT-Ialpha gene expression. Our studies demonstrate that CPT-Ialpha is a TATA-less gene which utilizes NF-Y and Sp proteins to drive basal expression.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Mapeamento Cromossômico , Proteínas de Ligação a DNA/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Fígado/enzimologia , Regiões Promotoras Genéticas , Fator de Transcrição Sp1/fisiologia , Animais , Sequência de Bases , Proteínas Estimuladoras de Ligação a CCAAT , DNA , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Ratos , Células Tumorais Cultivadas
17.
J Biol Chem ; 274(1): 211-7, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9867832

RESUMO

Transcription of the gene for phosphoenolpyruvate carboxykinase (PEPCK) is stimulated by thyroid hormone (T3) and cAMP. Two DNA elements in the PEPCK promoter are required for T3 responsiveness including a thyroid hormone response element and a binding site called P3(I) for the CCAAT enhancer-binding protein (C/EBP). Both the alpha and beta isoforms of C/EBP are highly expressed in the liver. C/EBPalpha contributes to the liver-specific expression and cAMP responsiveness of the PEPCK gene. In this study, we examined the ability of C/EBPbeta when bound to the P3(I) site to regulate PEPCK gene expression. We report that C/EBPbeta can stimulate basal expression and participate in the induction of PEPCK gene transcription by T3 and cAMP. The cAMP-responsive element-binding protein and AP1 proteins that contribute to the induction by cAMP are not involved in the stimulation by T3. A small region of the transactivation domain of C/EBPbeta is sufficient for the stimulation of basal expression and cAMP responsiveness. Our results suggest that C/EBPalpha and C/EBPbeta are functionally interchangeable when bound to the P3(I) site of the PEPCK promoter.


Assuntos
AMP Cíclico/fisiologia , Proteínas de Ligação a DNA/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Proteínas Nucleares/fisiologia , Fosfoenolpiruvato Carboxiquinase (ATP)/genética , Hormônios Tireóideos/fisiologia , Transcrição Gênica/fisiologia , Sequência de Bases , Proteínas Estimuladoras de Ligação a CCAAT , Linhagem Celular , DNA , Proteínas de Ligação a DNA/genética , Humanos , Proteínas Nucleares/genética , Transfecção
18.
J Biol Chem ; 273(24): 14950-7, 1998 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-9614100

RESUMO

The alpha isoform of CCAAT/enhancer-binding protein (C/EBPalpha) is a transcription factor that regulates expression of genes linked to adipose differentiation and hepatic nutrient metabolism. Recently, our laboratory has characterized a role for C/EBPalpha in mediating hormonal responsiveness. For example, the cAMP responsiveness of the phosphoenolpyruvate carboxykinase gene promoter in liver requires synergism among the cAMP response element-binding protein (CREB), C/EBPalpha, and activator protein-1. In the present study, we show that C/EBPalpha can functionally substitute for CREB in this cAMP response unit, i.e. cAMP responsiveness can occur in the absence of CREB. This observation is physiologically relevant since both CREB and C/EBPalpha have been shown to bind with high affinity to the cAMP response element in this particular promoter. Structure/function analysis of C/EBPalpha identified specific mutations that differentially affected its constitutive and protein kinase A-inducible activities. This finding suggests that the mechanism whereby C/EBPalpha mediates constitutive transactivation is distinct from that whereby it mediates cAMP responsiveness. These data support the hypothesis that C/EBPalpha plays a critical role in metabolism, in part by participating in the hormonal regulation of expression of metabolically important genes.


Assuntos
Núcleo Celular/fisiologia , AMP Cíclico/farmacologia , Proteínas de Ligação a DNA/fisiologia , Proteínas Nucleares/fisiologia , Proteínas Estimuladoras de Ligação a CCAAT , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/genética , Mutação/genética , Proteínas Nucleares/genética , Fosfoenolpiruvato Carboxiquinase (GTP)/genética , Regiões Promotoras Genéticas/genética , Relação Estrutura-Atividade , Fator de Transcrição AP-1/fisiologia , Fatores de Transcrição/fisiologia , Ativação Transcricional/genética , Células Tumorais Cultivadas
19.
Biochem J ; 330 ( Pt 1): 217-24, 1998 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9461513

RESUMO

Carnitine palmitoyltransferase I (CPTI) catalyses the transfer of long chain fatty acids to carnitine for translocation across the mitochondrial inner membrane. The cDNAs of two isoforms of CPT I, termed the hepatic and muscle isoforms, have been cloned. Expression of the hepatic CPT I gene (L-CPT I) is subject to developmental, hormonal and tissue specific regulation. We have cloned the promoter of the L-CPTI gene from a rat genomic library. In the L-CPTI gene, there are two exons 5' to the exon containing the ATG that initiates translation. Exon 1 and the 5' end of exon 2 contain sequences that were not previously described in the rat L-CPTI cDNA. There is an alternatively spliced form of the L-CPTI mRNA in which exon 2 is skipped. The proximal promoter of the L-CPTI gene is extremely GC rich and does not contain a TATA box. There are several putative Sp1 binding sites near the transcriptional start site. A 190 base pair fragment of the promoter can efficiently drive transcription of luciferase and CAT (chloramphenicol acetyltransferase) reporter genes transiently transfected into HepG2 cells. Sequences in both the first intron and the promoter contribute to basal expression. Our results provide the foundation for further studies into the regulation of L-CPTI gene expression.


Assuntos
Carnitina O-Palmitoiltransferase/genética , Isoenzimas/genética , Fígado/enzimologia , Processamento Alternativo , Animais , Sequência de Bases , Sítios de Ligação , DNA Complementar/genética , Regulação Enzimológica da Expressão Gênica , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Ratos , Mapeamento por Restrição , Distribuição Tecidual , Transcrição Gênica
20.
Mol Cell Biochem ; 178(1-2): 1-8, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9546576

RESUMO

The transcription rate of many genes, and particularly those which code for metabolically important proteins, is regulated by various hormones. Detailed analysis of the promoters of these genes has shown that, while functional 'Hormone response elements' exist, the hormonal responsiveness of many promoters is often synergistically mediated by several cis-elements, collectively referred to as a hormone response unit. The utilization of a hormone response unit to mediate a response offers several regulatory advantages, including an expansion of the range of transcriptional responses and modulation of the response by tissue- and developmental-specific cues. Furthermore, the presence of Hormone Response Units may provide a mechanism for the coordination of information from two or more signaling pathways into a single, integrated and exquisitely controlled transcriptional response. The protein-protein interactions that likely mediate many of the synergistic functional characteristics of Hormone Response Units may provide unique targets for therapeutic intervention.


Assuntos
Regulação da Expressão Gênica , Hormônios/fisiologia , Regiões Promotoras Genéticas , Animais , Humanos , Transcrição Gênica
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