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

RESUMEN

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.


Asunto(s)
Dedos/irrigación sanguínea , Angiografía por Resonancia Magnética , Inhibidores de Fosfodiesterasa 5/uso terapéutico , Pirimidinas/uso terapéutico , Enfermedad de Raynaud/tratamiento farmacológico , Flujo Sanguíneo Regional , Sulfonamidas/uso terapéutico , Adulto , Estudios de Cohortes , Enfermedades del Tejido Conjuntivo/complicaciones , Femenino , Dedos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Enfermedad de Raynaud/diagnóstico , Enfermedad de Raynaud/etiología , Resultado del Tratamiento , Ultrasonografía
2.
Gene Ther ; 20(7): 717-22, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23151518

RESUMEN

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.


Asunto(s)
Puente de Arteria Coronaria , Técnicas de Transferencia de Gen , Corazón/diagnóstico por imagen , Factor de Crecimiento de Hepatocito/genética , Isquemia Miocárdica/terapia , Vacunas de ADN/administración & dosificación , Anciano , Femenino , Corazón/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/genética , Isquemia Miocárdica/cirugía , Miocardio , Neovascularización Fisiológica/genética , Radiografía , Tomografía Computarizada de Emisión de Fotón Único , Vacunas de ADN/genética
3.
Phlebology ; 27(5): 235-41, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22037280

RESUMEN

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.


Asunto(s)
Imagenología Tridimensional , Angiografía por Resonancia Magnética , Vena Safena/diagnóstico por imagen , Várices/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios , Radiografía , Estudios Retrospectivos , Vena Safena/cirugía , Várices/cirugía
4.
Mini Rev Med Chem ; 9(3): 329-39, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19275726

RESUMEN

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.


Asunto(s)
Multimerización de Proteína , Estructura Cuaternaria de Proteína , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Animales , Humanos , Dominios y Motivos de Interacción de Proteínas/fisiología , Subunidades de Proteína/química , Subunidades de Proteína/fisiología , Transducción de Señal/fisiología
5.
Clin Radiol ; 64(2): 127-32, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19103341

RESUMEN

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.


Asunto(s)
Nódulo Pulmonar Solitario/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Calcinosis/diagnóstico por imagen , Calcinosis/patología , Femenino , Humanos , Cuidados a Largo Plazo , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Estudios Retrospectivos , Nódulo Pulmonar Solitario/patología , Tomografía Computarizada por Rayos X/métodos
6.
J Parasitol ; 95(3): 768-71, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19071966

RESUMEN

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.


Asunto(s)
Momias/parasitología , Estrongiloidiasis/historia , Tricostrongiliasis/historia , Animales , Heces/parasitología , Historia del Siglo XVII , Humanos , Corea (Geográfico) , Larva/clasificación , Masculino , Óvulo/clasificación , Strongyloides stercoralis/clasificación , Strongyloides stercoralis/aislamiento & purificación , Trichostrongylus/clasificación , Trichostrongylus/aislamiento & purificación
7.
J Recept Signal Transduct Res ; 28(5): 437-51, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18946765

RESUMEN

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.


Asunto(s)
Proteínas de Unión al GTP/agonistas , Proteínas de Unión al GTP/metabolismo , Receptores de Neuropéptido Y/metabolismo , Animales , Células CHO , Cricetinae , Cricetulus , Estrenos/farmacología , Guanosina 5'-O-(3-Tiotrifosfato)/farmacología , Humanos , Ratones , Inhibidores de Fosfodiesterasa/farmacología , Multimerización de Proteína , Pirrolidinonas/farmacología , Conejos , Receptores de Neuropéptido Y/química
8.
J Recept Signal Transduct Res ; 28(3): 245-63, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18569526

RESUMEN

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.


Asunto(s)
Riñón/metabolismo , Prosencéfalo/metabolismo , Receptores de Neuropéptido Y/metabolismo , Animales , Células CHO , Cationes Bivalentes/farmacología , Cricetinae , Cricetulus , Dimerización , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Humanos , Masculino , Unión Proteica/efectos de los fármacos , Conejos , Ratas , Receptores de Neuropéptido Y/agonistas , Transducción de Señal/efectos de los fármacos , Fracciones Subcelulares/efectos de los fármacos , Fracciones Subcelulares/metabolismo
9.
J Hum Hypertens ; 21(11): 868-74, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17476289

RESUMEN

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.


Asunto(s)
Peso al Nacer , Presión Sanguínea , Crecimiento , Índice de Masa Corporal , Enfermedades Cardiovasculares/etiología , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Masculino , Análisis de Regresión , Aumento de Peso
10.
Eur J Clin Nutr ; 58(10): 1365-71, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15054416

RESUMEN

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.


Asunto(s)
Ácido Ascórbico/sangre , Peso al Nacer , Estatura , Desarrollo Fetal/efectos de los fármacos , Segundo Trimestre del Embarazo/sangre , Vitamina E/sangre , Antioxidantes/administración & dosificación , Antioxidantes/análisis , Ácido Ascórbico/administración & dosificación , Peso al Nacer/efectos de los fármacos , Estatura/efectos de los fármacos , Estudios de Cohortes , Dieta , Sinergismo Farmacológico , Femenino , Humanos , Recién Nacido , Masculino , Intercambio Materno-Fetal , Recuerdo Mental , Embarazo , Resultado del Embarazo , Estudios Prospectivos , Vitamina E/administración & dosificación
11.
J Korean Med Sci ; 16(1): 127-9, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11289392

RESUMEN

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.


Asunto(s)
Hemangioendotelioma/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Metilprednisolona/administración & dosificación , Neoplasias Cutáneas/tratamiento farmacológico , Humanos , Recién Nacido , Masculino
12.
Biochem J ; 354(Pt 1): 189-97, 2001 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-11171094

RESUMEN

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.


Asunto(s)
Carnitina O-Palmitoiltransferasa/genética , Ácidos Grasos/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Hígado/enzimología , Receptores Citoplasmáticos y Nucleares/fisiología , Factores de Transcripción/fisiología , Animales , Secuencia de Bases , Células Cultivadas , Clofibrato/farmacología , Cartilla de ADN , Inhibidores Enzimáticos/farmacología , Femenino , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Receptores Citoplasmáticos y Nucleares/genética , Factores de Transcripción/genética , Células Tumorales Cultivadas
13.
J Mol Cell Cardiol ; 33(2): 317-29, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11162136

RESUMEN

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.


Asunto(s)
Carnitina O-Palmitoiltransferasa/genética , Carnitina O-Palmitoiltransferasa/metabolismo , Regulación Enzimológica de la Expresión Génica , Miocardio/enzimología , Factores de Edad , Animales , Sitios de Unión , Carcinoma Hepatocelular/metabolismo , Carnitina O-Palmitoiltransferasa/química , Núcleo Celular/metabolismo , Células Cultivadas , Diabetes Mellitus Experimental/enzimología , Grasas de la Dieta/farmacología , Ácidos Grasos/metabolismo , Femenino , Genes Reporteros , Vectores Genéticos , Corazón/embriología , Hipertiroidismo/enzimología , Cinética , Hígado/enzimología , Neoplasias Hepáticas/metabolismo , Luciferasas/metabolismo , Masculino , Miocardio/citología , Regiones Promotoras Genéticas , Isoformas de Proteínas , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Factor de Transcripción Sp1/genética , Factores de Tiempo , Distribución Tisular , Transfección , Células Tumorales Cultivadas
14.
J Biol Chem ; 275(45): 34989-97, 2000 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-10956641

RESUMEN

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.


Asunto(s)
Carnitina O-Palmitoiltransferasa/genética , Carnitina O-Palmitoiltransferasa/metabolismo , Regulación Enzimológica de la Expresión Génica , Intrones , Regiones Promotoras Genéticas , Hormonas Tiroideas/metabolismo , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Línea Celular , Núcleo Celular/metabolismo , Células Cultivadas , Desoxirribonucleasa I/metabolismo , Escherichia coli/metabolismo , Ácidos Grasos/metabolismo , Humanos , Hígado/enzimología , Luciferasas/metabolismo , Modelos Genéticos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Miocardio/metabolismo , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Ratas , Proteínas Recombinantes/metabolismo , Elementos de Respuesta , Análisis de Secuencia de ADN , Transfección , Triyodotironina/metabolismo
15.
Am J Med Sci ; 318(1): 43-8, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10408760

RESUMEN

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.


Asunto(s)
Carnitina O-Palmitoiltransferasa/genética , Ácidos Grasos/metabolismo , Regulación Enzimológica de la Expresión Génica , Mitocondrias/enzimología , Animales , Humanos , Isoenzimas/genética , Mitocondrias Cardíacas/enzimología , Mitocondrias Hepáticas/enzimología , Oxidación-Reducción
16.
Biochem J ; 340 ( Pt 2): 425-32, 1999 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-10333485

RESUMEN

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.


Asunto(s)
Carnitina O-Palmitoiltransferasa/genética , Mapeo Cromosómico , Proteínas de Unión al ADN/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Hígado/enzimología , Regiones Promotoras Genéticas , Factor de Transcripción Sp1/fisiología , Animales , Secuencia de Bases , Proteínas Potenciadoras de Unión a CCAAT , ADN , Hibridación Fluorescente in Situ , Datos de Secuencia Molecular , Ratas , Células Tumorales Cultivadas
17.
J Biol Chem ; 274(1): 211-7, 1999 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-9867832

RESUMEN

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.


Asunto(s)
AMP Cíclico/fisiología , Proteínas de Unión al ADN/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Proteínas Nucleares/fisiología , Fosfoenolpiruvato Carboxiquinasa (ATP)/genética , Hormonas Tiroideas/fisiología , Transcripción Genética/fisiología , Secuencia de Bases , Proteínas Potenciadoras de Unión a CCAAT , Línea Celular , ADN , Proteínas de Unión al ADN/genética , Humanos , Proteínas Nucleares/genética , Transfección
18.
J Biol Chem ; 273(24): 14950-7, 1998 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-9614100

RESUMEN

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.


Asunto(s)
Núcleo Celular/fisiología , AMP Cíclico/farmacología , Proteínas de Unión al ADN/fisiología , Proteínas Nucleares/fisiología , Proteínas Potenciadoras de Unión a CCAAT , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/fisiología , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica/genética , Mutación/genética , Proteínas Nucleares/genética , Fosfoenolpiruvato Carboxiquinasa (GTP)/genética , Regiones Promotoras Genéticas/genética , Relación Estructura-Actividad , Factor de Transcripción AP-1/fisiología , Factores de Transcripción/fisiología , Activación Transcripcional/genética , Células Tumorales Cultivadas
19.
Biochem J ; 330 ( Pt 1): 217-24, 1998 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-9461513

RESUMEN

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.


Asunto(s)
Carnitina O-Palmitoiltransferasa/genética , Isoenzimas/genética , Hígado/enzimología , Empalme Alternativo , Animales , Secuencia de Bases , Sitios de Unión , ADN Complementario/genética , Regulación Enzimológica de la Expresión Génica , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Ratas , Mapeo Restrictivo , Distribución Tisular , Transcripción Genética
20.
Mol Cell Biochem ; 178(1-2): 1-8, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9546576

RESUMEN

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.


Asunto(s)
Regulación de la Expresión Génica , Hormonas/fisiología , Regiones Promotoras Genéticas , Animales , Humanos , Transcripción Genética
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