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1.
Cytotherapy ; 7(3): 282-91, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16081355

RESUMEN

Animal and early clinical studies have provided evidence suggesting that intracoronary administration of autologous bone marrow-derived cells results in improved outcome following myocardial infarction. Animal studies with cultured marrow stromal cells (MSC) have provided similar data. Cells with properties that are similar to MSC have been identified in adipose tissue. Other groups have demonstrated in vivo differentiation of adipose tissue-derived cells (ADC) into cells exhibiting biochemical and functional markers of cardiac myocytes, including spontaneous beating. Based on these observations, the objective of the present study was to determine whether ADC might undergo similar differentiation in vivo in the context of myocardial injury.ADC were isolated from subcutaneous adipose tissue of Rosa26 mice (which express the beta-galactosidase transgene in almost every tissue) and injected into the intraventricular chamber of B6129S recipient mice immediately following induction of myocardial cryoinjury. Groups of recipients were euthanized at 24 hours, 7 and 14 days post surgery and examined for the presence of donor-derived cells within the heart.Beta-gal positive cells were identified in the infarcts of ADC-treated animals. No staining was observed in uninjured myocardium or in infarcts of control animals. Immunohistochemical analysis revealed co-expression of beta-gal with Myosin Heavy Chain, Nkx2.5 and with Troponin I. Co-expression of beta-galactosidase with Connexin 43, CD31, von Willebrand factor, MyoD or CD45 was not detected.Thus, these data indicate that adipose tissue contains a population of cells that has the ability to engraft injured myocardium and that this engraftment is associated with expression of cardiomyocytic markers by donor-derived cells.


Asunto(s)
Adipocitos/citología , Adipocitos/trasplante , Células Madre Multipotentes/citología , Infarto del Miocardio/terapia , Miocardio/citología , Adipocitos/metabolismo , Animales , Biomarcadores/metabolismo , Diferenciación Celular , Células Cultivadas , Células Endoteliales/citología , Ratones , Infarto del Miocardio/patología , Miocardio/metabolismo , Miocitos Cardíacos/citología
2.
Mol Cell Biol ; 25(6): 2486-97, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15743840

RESUMEN

The pocket protein family of tumor suppressors, and Rb specifically, have been implicated as controlling terminal differentiation in many tissues, including the heart. To establish the biological functions of Rb in the heart and overcome the early lethality caused by germ line deletion of Rb, we used a Cre/loxP system to create conditional, heart-specific Rb-deficient mice. Mice that are deficient in Rb exclusively in cardiac myocytes (CRbL/L) are born with the expected Mendelian distribution, and the adult mice displayed no change in heart size, myocyte cell cycle distribution, myocyte apoptosis, or mechanical function. Since both Rb and p130 are expressed in the adult myocardium, we created double-knockout mice (CRbL/L p130-/-) to determine it these proteins have a shared role in regulating cardiac myocyte cell cycle progression. Adult CRbL/L p130-/- mice demonstrated a threefold increase in the heart weight-to-body weight ratio and showed increased numbers of bromodeoxyuridine- and phosphorylated histone H3-positive nuclei, consistent with persistent myocyte cycling. Likewise, the combined deletion of Rb plus p130 up-regulated myocardial expression of Myc, E2F-1, and G1 cyclin-dependent kinase activities, synergistically. Thus, Rb and p130 have overlapping functional roles in vivo to suppress cell cycle activators, including Myc, and maintain quiescence in postnatal cardiac muscle.


Asunto(s)
Miocitos Cardíacos/fisiología , Proteínas/fisiología , Proteína de Retinoblastoma/fisiología , Animales , Ciclo Celular/genética , Ciclo Celular/fisiología , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Núcleo Celular/metabolismo , Ciclina G , Ciclina G1 , Quinasas Ciclina-Dependientes/genética , Quinasas Ciclina-Dependientes/metabolismo , Ciclinas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Factores de Transcripción E2F , Factor de Transcripción E2F1 , Eliminación de Gen , Mutación de Línea Germinal , Histonas/metabolismo , Ratones , Ratones Noqueados , Mutación/genética , Miocardio/química , Miocardio/citología , Miocardio/metabolismo , Miocitos Cardíacos/metabolismo , Fosforilación , Regiones Promotoras Genéticas/genética , Proteínas/análisis , Proteínas/genética , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteína de Retinoblastoma/análisis , Proteína de Retinoblastoma/genética , Proteína p130 Similar a la del Retinoblastoma , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/fisiología , Regulación hacia Arriba
3.
Circ Res ; 89(12): 1122-9, 2001 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-11739276

RESUMEN

c-Myc, a protooncogene, mediates both proliferative and cellular growth in many cell types. Although not expressed in the adult heart under normal physiological conditions, Myc expression is rapidly upregulated in response to hypertrophic stimuli. Although Myc is capable of sustaining hyperplastic growth in fetal myocytes, the effects of its re-expression in adult postmitotic myocardium and its role in mediating cardiac hypertrophy are unknown. To determine the effects of de novo Myc activity in adult postmitotic myocardium in vivo, we created a novel transgenic model in which Myc is expressed and inducibly activated specifically in cardiac myocytes. Activation of Myc in adult myocardium was sufficient to reproduce the characteristic changes in myocyte size, protein synthesis, and cardiac-specific gene expression seen in cardiac hypertrophy. Despite the increased cardiac mass, left ventricular function remained normal. Activation of Myc also provoked cell cycle reentry in postmitotic myocytes, which led to increased nuclei per myocyte and DNA content per nuclei.


Asunto(s)
Cardiomegalia/metabolismo , ADN/biosíntesis , Miocardio/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Tamoxifeno/análogos & derivados , Animales , Cardiomegalia/patología , Ciclo Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/efectos de los fármacos , Corazón/efectos de los fármacos , Humanos , Ligandos , Ratones , Ratones Endogámicos C3H , Ratones Transgénicos , Miocardio/patología , Cadenas Pesadas de Miosina/genética , Tamaño de los Órganos/efectos de los fármacos , Especificidad de Órganos/efectos de los fármacos , Ploidias , Proteínas Proto-Oncogénicas c-myc/genética , Receptores de Estrógenos/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Tamoxifeno/farmacología , Regulación hacia Arriba/efectos de los fármacos , Miosinas Ventriculares/genética
4.
J Am Coll Cardiol ; 38(3): 789-95, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11527635

RESUMEN

OBJECTIVES: The study aimed to evaluate the role of obesity in the prognosis of patients with heart failure (HF). BACKGROUND: Previous reports link obesity to the development of HF. However, the impact of obesity in patients with established HF has not been studied. METHODS: We analyzed 1,203 patients with advanced HF followed in a comprehensive HF management program. The patients were subclassified into categories of body mass index (BMI) defined as: underweight BMI <20.7 (n = 164), recommended BMI 20.7 to 27.7 (n = 692), overweight BMI 27.8 to 31 (n = 168) and obese BMI >31 (n = 179). This sample size allows the detection of small effects (0.02), with a power of 0.80 and an alpha level of 0.05 for comparing one-year survival between BMI groups. RESULTS: The four BMI groups had similar profiles in terms of ejection fraction (mean 0.22), sodium, creatinine and smoking. The obese and overweight groups had significantly higher rates of hypertension and diabetes, as well as higher levels of cholesterol, triglycerides and low density lipoprotein cholesterol. The four BMI groups had similar survival rates. Ejection fraction, HF etiology and angiotensin-converting enzyme inhibitor use predicted survival on univariate analysis (p < 0.01), although BMI did not. On multivariate analysis, cardiopulmonary exercise tests, pulmonary capillary wedge pressure and serum sodium were strong predictors of survival (p < 0.05). Higher BMI was not a risk factor for increased mortality, but was associated with a trend toward improved survival. CONCLUSIONS: In a large cohort of patients with advanced HF of multiple etiologies, obesity is not associated with increased mortality and may confer a more favorable prognosis. Further studies need to delineate whether weight loss promotion in medically optimized patients with HF is a worthwhile therapeutic goal.


Asunto(s)
Insuficiencia Cardíaca/mortalidad , Obesidad/epidemiología , Adulto , Índice de Masa Corporal , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/tratamiento farmacológico , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Presión Esfenoidal Pulmonar , Análisis de Regresión
5.
Circulation ; 104(7): 826-31, 2001 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-11502710

RESUMEN

BACKGROUND: The mechanisms responsible for tumor necrosis factor (TNF)-induced LV structural remodeling in the adult heart are not known. METHODS AND RESULTS: We generated a line of transgenic mice (MHCsTNF) with cardiac restricted overexpression of TNF that develop progressive LV dilation/remodeling from 4 to 12 weeks of age. During the early phases of LV structural remodeling, there was a significant increase in total matrix metalloproteinase (MMP) activity that corresponded to a decrease in total myocardial fibrillar collagen content. As the MHCsTNF mice aged, there was a significant decrease in total MMP zymographic activity that was accompanied by an increase in total fibrillar collagen content. The changes in total MMP activity and myocardial fibrillar collagen content were related to a time- dependent increase in myocardial tissue inhibitor of metalloproteinases (TIMP)-1 levels, resulting in a significant time-dependent decrease in the MMP activity/TIMP level ratio in the MHCsTNF mice. To determine a possible mechanism for the increase in myocardial fibrosis, we also measured levels of TGF-beta(1) and TGF-beta(2) protein levels, which were shown to be significantly elevated in the hearts of the MHCsTNF mice. CONCLUSIONS: Our results suggest that progressive time-dependent changes in the balance between MMP activity and TIMP activity are responsible, at least in part, for the spectrum of TNF-induced changes in the myofibrillar collagen content that occur during LV structural remodeling in the MHCsTNF mice.


Asunto(s)
Cardiomegalia/metabolismo , Expresión Génica/fisiología , Miocardio/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Remodelación Ventricular , Envejecimiento/metabolismo , Animales , Northern Blotting , Cardiomegalia/genética , Cardiomegalia/patología , Colágeno/metabolismo , Citocinas/genética , Citocinas/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miocardio/ultraestructura , Miofibrillas/metabolismo , Miofibrillas/ultraestructura , Especificidad de Órganos/fisiología , ARN Mensajero/metabolismo , Inhibidores Tisulares de Metaloproteinasas/metabolismo , Factor de Necrosis Tumoral alfa/genética , Remodelación Ventricular/fisiología
7.
Mol Cell Biol ; 20(23): 8903-15, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11073990

RESUMEN

The retinoblastoma protein (Rb) regulates both the cell cycle and tissue-specific transcription, by modulating the activity of factors that associate with its A-B and C pockets. In skeletal muscle, Rb has been reported to regulate irreversible cell cycle exit and muscle-specific transcription. To identify factors interacting with Rb in muscle cells, we utilized the yeast two-hybrid system, using the A-B and C pockets of Rb as bait. A novel protein we have designated E1A-like inhibitor of differentiation 1 (EID-1), was the predominant Rb-binding clone isolated. It is preferentially expressed in adult cardiac and skeletal muscle and encodes a 187-amino-acid protein, with a classic Rb-binding motif (LXCXE) in its C terminus. Overexpression of EID-1 in skeletal muscle inhibited tissue-specific transcription. Repression of skeletal muscle-restricted genes was mediated by a block to transactivation by MyoD independent of G(1) exit and, surprisingly, was potentiated by a mutation that prevents EID-1 binding to Rb. Inhibition of MyoD may be explained by EID-1's ability to bind and inhibit p300's histone acetylase activity, an essential MyoD coactivator. Thus, EID-1 binds both Rb and p300 and is a novel repressor of MyoD function.


Asunto(s)
Proteínas E1A de Adenovirus/metabolismo , Músculo Esquelético/metabolismo , Proteína MioD/metabolismo , Proteínas Nucleares/metabolismo , Proteína de Retinoblastoma/metabolismo , Proteínas de Saccharomyces cerevisiae , Transactivadores/metabolismo , Activación Transcripcional , Acetiltransferasas/antagonistas & inhibidores , Proteínas E1A de Adenovirus/genética , Secuencia de Aminoácidos , Proteínas de Ciclo Celular , Clonación Molecular , Regulación de la Expresión Génica , Histona Acetiltransferasas , Datos de Secuencia Molecular , Unión Proteica , Proteínas Represoras , Distribución Tisular , Técnicas del Sistema de Dos Híbridos
8.
Curr Opin Cardiol ; 15(3): 128-35, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10952417

RESUMEN

Congestive heart failure is a common clinical problem resulting in significant morbidity and mortality. Although considerable progress has been made in elucidating the pathophysiologic mechanisms that lead to the development of this process, much remains unknown. The techniques of modern molecular biology now allow a detailed and systematic analysis of this disease. Recent data linking cardiac hypertrophy, aberrant signaling, or cytoskeletal abnormalities to the development of heart failure have provided new insights into this process. These studies have confirmed the importance of many classical pathways but also revealed novel pathways. This review will focus on the recent advances that have been made and will highlight the importance they have had in our understanding and treatment of heart failure.


Asunto(s)
Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/fisiopatología , Biología Molecular , Transducción de Señal , Angiotensinas/fisiología , Antígenos CD/fisiología , Apoptosis/fisiología , Calcineurina/fisiología , Cardiomegalia/complicaciones , Receptor gp130 de Citocinas , Citocinas/fisiología , Citoesqueleto/fisiología , Expresión Génica/fisiología , Sustancias de Crecimiento/fisiología , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/terapia , Hemodinámica , Humanos , Glicoproteínas de Membrana/fisiología , Proteínas Quinasas/fisiología , Transducción de Señal/fisiología
9.
Annu Rev Physiol ; 62: 289-319, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10845093

RESUMEN

Cardiac muscle cells exhibit two related but distinct modes of growth that are highly regulated during development and disease. Cardiac myocytes rapidly proliferate during fetal life but exit the cell cycle irreversibly soon after birth, following which the predominant form of growth shifts from hyperplastic to hypertrophic. Much research has focused on identifying the candidate mitogens, hypertrophic agonists, and signaling pathways that mediate these processes in isolated cells. What drives the proliferative growth of embryonic myocardium in vivo and the mechanisms by which adult cardiac myocytes hypertrophy in vivo are less clear. Efforts to answer these questions have benefited from rapid progress made in techniques to manipulate the murine genome. Complementary technologies for gain- and loss-of-function now permit a mutational analysis of these growth control pathways in vivo in the intact heart. These studies have confirmed the importance of suspected pathways, have implicated unexpected pathways as well, and have led to new paradigms for the control of cardiac growth.


Asunto(s)
Corazón/crecimiento & desarrollo , Transducción de Señal/genética , Animales , Humanos , Miocardio/citología , Miocardio/patología
12.
Circ Res ; 81(2): 137-44, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9242174

RESUMEN

Programmed cell death (apoptosis) is recognized, increasingly, as a contributing cause of cardiac myocyte loss with ischemia/reperfusion injury, myocardial infarction, and long-standing heart failure. Although the exact mechanisms initiating apoptosis in these in vivo settings remain unproven, insights into the molecular circuitry controlling apoptosis more widely suggest the potential to protect mammalian ventricular muscle from apoptosis through one or more of these pathways, by pharmacological means or, conceivably, gene transfer.


Asunto(s)
Apoptosis/fisiología , Enfermedades Cardiovasculares , Sistema Cardiovascular , Animales , Humanos
13.
J Biol Chem ; 271(18): 10827-33, 1996 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-8631897

RESUMEN

"Fetal" gene transcription, including activation of the skeletal alpha-actin (SkA) promoter, is provoked in cardiac myocytes by mechanical stress and trophic ligands. Induction of the promoter by transforming growth factor beta or norepinephrine requires serum response factor (SRF) and TEF-1; expression is inhibited by YY1. We and others postulated that immediate-early transcription factors might couple trophic signals to this fetal program. However, multiple Fos/Jun proteins exist, and the exact relationship between control by Fos/Jun versus SRF, TEF-1, and YY1 is unexplained. We therefore cotransfected ventricular myocytes with Fos, Jun, or JunB, and SkA reporter genes. SkA transcription was augmented by Jun, Fos/Jun, Fos/JunB, and Jun/JunB; Fos and JunB alone were neutral or inhibitory. Mutation of the SRF site, SRE1, impaired activation by Jun; YY1, TEF-1, and Sp1 sites were dispensable. SRE1 conferred Jun activation to a heterologous promoter, as did the c-fos SRE. Deletions of DNA binding, dimerization, or trans-activation domains of Jun and SRF abolished activation by Jun and synergy with SRF. Neither direct binding of Fos/Jun to SREs, nor physical interaction between Fos/Jun and SRF, was detected in mobility-shift assays. Thus, AP-1 factors activate a hypertrophy-associated gene via SRF, without detectable binding to the promoter or to SRF.


Asunto(s)
Actinas/genética , Proteínas de Unión al ADN/metabolismo , Ventrículos Cardíacos/metabolismo , Músculo Esquelético/metabolismo , Proteínas Nucleares/metabolismo , Regiones Promotoras Genéticas , Factor de Transcripción AP-1/metabolismo , Animales , Secuencia de Bases , Células Cultivadas , Ventrículos Cardíacos/citología , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Ratas , Ratas Sprague-Dawley , Factor de Respuesta Sérica , TATA Box , Activación Transcripcional
14.
Mol Reprod Dev ; 39(1): 112-7, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7528025

RESUMEN

Skeletal alpha-actin (SkA) is representative of the cardiac genes that are expressed at high levels in embryonic myocardium, downregulated after birth, and reactivated by tropic signals including basic fibroblast growth factor (FGF-2) and type beta transforming growth factors (TGF beta). To investigate the molecular basis for cardiac-restricted and growth factor-induced SkA transcription, we have undertaken a mutational analysis of the SkA promoter in neonatal ventricular myocytes, with emphasis on the role of three nominal serum response elements. Serum response factor (SRF) and the bifunctional factor YY1 are the predominant cardiac proteins contacting the proximal SRE (SRE1). Mutations of SRE1 that prevent recognition by SRF and YY1. or SRF alone, virtually abolish SkA transcription; mutation of distal SREs was ineffective. A mutation which selectively abrogates YY1 binding increases expression, substantiating the predicted role of YY1 as an inhibitor of SRF effects. SkA transcription requires combinational action of SRE1 with consensus sites for Sp1 and the SV40 enhancer binding protein, TEF-1. As an isolated motif, SRE1 can confer responsiveness to both FGF-2 and TGF beta to a heterologous promoter. Whether TEF-1 binding sites likewise can function as FGF response elements is unknown. Molecular dissection of mechanisms that govern the differentiated cardiac phenotype has largely been undertaken to date in neonatal ventricular myocytes, as the adult ventricular myocyte has been refractory to conventional procedures for gene transfer. To circumvent expected limitations of other methods, we have used replication-deficient adenovirus to achieve efficient gene transfer to adult cardiac cells in culture.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Actinas/biosíntesis , Factor 1 de Crecimiento de Fibroblastos/farmacología , Factor 2 de Crecimiento de Fibroblastos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Miocardio/metabolismo , Transcripción Genética/efectos de los fármacos , Animales , Técnicas de Transferencia de Gen , Regiones Promotoras Genéticas , Receptores de Factores de Crecimiento Transformadores beta/fisiología , Factor de Crecimiento Transformador beta/farmacología
15.
J Biol Chem ; 269(22): 15423-6, 1994 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-8195182

RESUMEN

The molecular mechanisms for signaling by receptor serine/threonine kinases are incompletely understood. To test the potential involvement of p21 H-Ras proteins in signal transduction for type beta transforming growth factors (TGF beta), TGF beta-responsive and constitutive reporter genes were cotransfected into cardiac myocytes and mink lung epithelial cells, with dominant inhibitory (Asn-17) or activated (Arg-12) Ras expression vectors. Asn-17 Ras inhibited both TGF beta-dependent and basal expression of inducible promoters (skeletal alpha-actin and plasminogen activator inhibitor-1), with equivalent dose-response relations. All seven reporter constructs were comparably sensitive to down-regulation by Asn-17 Ras, including those driven by nominally constitutive viral control regions or a TATA-less initiator element. All constructs were up-regulated by Arg-12 Ras more variably. Wild-type Ras had intermediate effects and could rescue a minimal thymidine kinase promoter from inhibition by dominant negative Ras. Thus, a Ras-dependent event is required for efficient expression of an unexpectedly global or inclusive set of genes.


Asunto(s)
Regulación de la Expresión Génica , Miocardio/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Factor de Crecimiento Transformador beta/biosíntesis , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Línea Celular , Células Cultivadas , Luciferasas/biosíntesis , Luciferasas/metabolismo , Pulmón , Visón , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Prenilación de Proteína , Proteínas Proto-Oncogénicas p21(ras)/biosíntesis , Conejos , Transducción de Señal , Simplexvirus/enzimología , Simplexvirus/genética , Timidina Quinasa/biosíntesis , Timidina Quinasa/genética , Transfección , beta-Galactosidasa/biosíntesis , beta-Galactosidasa/metabolismo
16.
J Biol Chem ; 269(24): 16754-60, 1994 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-8206998

RESUMEN

Skeletal alpha-actin (SkA) is representative of the cardiac genes that are expressed at high levels in embryonic myocardium, down-regulated after birth, and reactivated by trophic signals including type beta-transforming growth factors (TGF beta). To investigate the molecular basis for cardiac-restricted and TGF beta-induced SkA transcription, we have undertaken a mutational analysis of the SkA promoter in ventricular myocytes, with emphasis on the role of three nominal serum response elements. Serum response factor (SRF) and the bifunctional factor YY1 are the predominant cardiac proteins contacting the proximal SRE (SRE1). Mutations of SRE1 that prevent recognition by SRF and YY1, or SRF alone, virtually abolish SkA transcription in both TGF beta- and vehicle-treated cells; mutation of distal SREs was ineffective. A mutation which selectively abrogates YY1 binding increases both basal and TGF beta-dependent expression, substantiating the predicted role of YY1 as an inhibitor of SRF effects. However, efficient SkA transcription requires combinatorial action of SRE1 with consensus sites for Sp1 and the SV40 enhancer-binding protein, TEF-1. As isolated motifs, either SRE1- or TEF-1-binding sites function as TGF beta response elements. Induction of the SkA promoter by TGF beta required SRF and TEF-1 in concert, unlike other pathways for TGF beta-dependent gene expression.


Asunto(s)
Actinas/genética , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Elementos de Facilitación Genéticos , Músculos/metabolismo , Proteínas Nucleares , Factores de Transcripción/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Actinas/biosíntesis , Animales , Animales Recién Nacidos , Secuencia de Bases , Sitios de Unión , Células Cultivadas , Pollos , Secuencia de Consenso , Factores de Unión al ADN Específico de las Células Eritroides , Datos de Secuencia Molecular , Miocardio/metabolismo , Oligodesoxirribonucleótidos/metabolismo , Ratas , Virus 40 de los Simios/metabolismo , TATA Box , Factores de Transcripción de Dominio TEA , Transfección , Factor de Crecimiento Transformador beta/farmacología , Factor de Transcripción YY1 , Dedos de Zinc
18.
Circ Res ; 73(5): 783-91, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8403249

RESUMEN

The transforming growth factor-beta (TGF-beta) superfamily comprises a set of regulatory peptides with multiple effects on cell growth and differentiation. The elaborate regulation of TGF-beta s during embryonic development of the heart, the upregulation of TGF-beta after hemodynamic stress, and the impact of TGF-beta on cardiac gene expression together imply a prominent functional role for this family of growth factors in cardiac organogenesis and hypertrophy. Basal and TGF-beta-induced expression of skeletal alpha-actin, one of several genes specifically associated with developing or hypertrophied myocardium, each are contingent on transcriptional activation by serum response factor. A truncated form of the type II TGF-beta receptor, created by deletion of the cytoplasmic kinase domain, acts as a dominant suppressor of TGF-beta signal transduction in cultured cardiac muscle cells and may provide a suitable means to establish the functions of TGF-beta in vivo.


Asunto(s)
Adaptación Fisiológica , Corazón/embriología , Factor de Crecimiento Transformador beta/fisiología , Animales , Regulación de la Expresión Génica , Corazón/fisiología , Humanos , Morfogénesis , Isquemia Miocárdica/etiología , Receptores de Factores de Crecimiento Transformadores beta/análisis , Receptores de Factores de Crecimiento Transformadores beta/fisiología
19.
J Clin Invest ; 92(1): 381-7, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8326005

RESUMEN

Molecular dissection of mechanisms that govern the differentiated cardiac phenotype has, for cogent technical reasons, largely been undertaken to date in neonatal ventricular myocytes. To circumvent expected limitations of other methods, the present study was initiated to determine whether replication-deficient adenovirus would enable efficient gene transfer to adult cardiac cells in culture. Adult rat ventricular myocytes were infected, 24 h after plating, with adenovirus type 5 containing a cytomegalovirus immediate-early promoter-driven lacZ reporter gene and were assayed for the presence of beta-galactosidase 48 h after infection. The frequency of lacZ+ rod-shaped myocytes was half-maximal at 4 x 10(5) plaque-forming units (PFU) and approached 90% at 1 x 10(8) PFU. Uninfected cells and cells infected with lacZ- virus remained colorless. Beta-galactosidase activity concurred with the proportion of lacZ+ cells and was contingent on the exogenous lacZ gene. At 10(8) PFU/dish, cell number, morphology, and viability each were comparable to uninfected cells. Thus, adult ventricular myocytes are amenable to efficient gene transfer with recombinant adenovirus. The relative uniformity for gene transfer by adenovirus should facilitate tests to determine the impact of putative regulators upon the endogenous genes and gene products of virally modified adult ventricular muscle cells.


Asunto(s)
Adenovirus Humanos/genética , Vectores Genéticos , Miocardio/citología , Transfección/métodos , Animales , Células Cultivadas , ADN Recombinante , Técnicas In Vitro , Masculino , Ratas , Ratas Sprague-Dawley
20.
J Biol Chem ; 268(16): 11500-3, 1993 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-8389353

RESUMEN

To prove the postulated role of type beta transforming growth factors (TGF beta) in cardiac development and other events, specific inhibitors of TGF beta signal transduction are needed. We truncated the type II TGF beta receptor cDNA (delta kT beta RII), to delete the predicted serine/threonine kinase cytoplasmic domain. delta kT beta RII was co-transfected into neonatal cardiac myocytes, together with reporter constructs for two cardiac-restricted genes that are regulated antithetically by TGF beta. delta kT beta RII impaired activation of the skeletal alpha-actin promoter by TGF beta 1, -2, and -3 and, conversely, impaired TGF beta inhibition of alpha-myosin heavy chain transcription. Thus, a kinase-defective T beta RII blocks signaling by all three mammalian TGF beta isoforms, and can disrupt both positive and negative control of transcription by TGF beta.


Asunto(s)
Miocardio/metabolismo , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Animales , Animales Recién Nacidos , Células Cultivadas , Regulación hacia Abajo/efectos de los fármacos , Humanos , Luciferasas/genética , Luciferasas/metabolismo , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Proteínas Serina-Treonina Quinasas/genética , Ratas , Receptores de Factores de Crecimiento Transformadores beta , Eliminación de Secuencia , Supresión Genética , Transcripción Genética/efectos de los fármacos , Transfección , Factor de Crecimiento Transformador beta/metabolismo , beta-Galactosidasa/genética , beta-Galactosidasa/metabolismo
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