RESUMEN
Notch is a ligand-receptor interaction-triggered signaling cascade highly conserved, that influences multiple lineage decisions within the hematopoietic and the immune system. It is a recognized model of intercellular communication that plays an essential role in embryonic as well as in adult immune cell development and homeostasis. Four members belong to the family of Notch receptors (Notch1-4), and each of them plays nonredundant functions at several developmental stages. Canonical and noncanonical pathways of Notch signaling are multifaceted drivers of immune cells biology. In fact, increasing evidence highlighted Notch as an important modulator of immune responses, also in cancer microenvironment. In these contexts, multiple transduction signals, including canonical and alternative NF-κB pathways, play a relevant role. In this chapter, we will first describe the critical role of Notch and NF-κB signals in lymphoid lineages developing in thymus: natural killer T cells, thymocytes, and thymic T regulatory cells. We will address also the role played by ligand expressing cells. Given the importance of Notch/NF-κB cross talk, its role in T-cell leukemia development and progression will be discussed.
Asunto(s)
Linaje de la Célula , Linfocitos/citología , Linfocitos/metabolismo , FN-kappa B/metabolismo , Receptores Notch/metabolismo , Transducción de Señal , Animales , HumanosRESUMEN
AIM: Ischemic stroke represents a major health problem and it is an important cause of long-term disability. The aim of this study was to compare short-term and mid-term results of carotid endarterectomy and stenting. METHODS: During a three-year period, we enrolled 300 patients with carotid stenosis that fit with Stroke Prevention and Educational Awareness Diffusion (SPREAD) guidelines and we performed 150 carotid endarterectomy operations (CEA) and 150 carotid artery stenting procedures (CAS) with distal protection devices. All patients underwent preoperative and postoperative: neurological examination, ultrasound imaging, magnetic resonance imaging (MRI) and cognitive tests; moreover all patients were submitted to preoperative, intraoperative and postoperative Transcranial Doppler (TCD) monitoring, in order to detect microembolic signals (MES). RESULTS: Mortality was zero; two patients developed myocardial infarction in the CEA group during follow-up. The main post-operative results after endarterectomy versus CAS were respectively: neurological deficit: 1.3% vs. 3.3%, embolic lesions at postoperative MRI: 4% vs. 34% and worsening of cognitive tests: 4% vs. 25.3%. CONCLUSION: CEA seems to be the treatment of choice for carotid stenosis, due to its low rate of mortality and morbidity, especially in asymptomatic patients; CAS should be carried out only in particular subgroup of cases, such as: restenosis, previous neck surgery or radian therapy, anatomical high bifurcation or extended lesions. Ongoing multicenter randomized trials may give a definitive answer to this matter.
Asunto(s)
Angioplastia de Balón/instrumentación , Estenosis Carotídea/terapia , Endarterectomía Carotidea , Stents , Accidente Cerebrovascular/prevención & control , Angioplastia de Balón/efectos adversos , Angioplastia de Balón/mortalidad , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico , Estenosis Carotídea/mortalidad , Estenosis Carotídea/psicología , Estenosis Carotídea/cirugía , Cognición , Imagen de Difusión por Resonancia Magnética , Endarterectomía Carotidea/efectos adversos , Endarterectomía Carotidea/mortalidad , Humanos , Infarto del Miocardio/etiología , Examen Neurológico , Pruebas Neuropsicológicas , Selección de Paciente , Valor Predictivo de las Pruebas , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/psicología , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía Doppler TranscranealRESUMEN
BACKGROUND: The true aneurysms of the infrapopliteal arteries are an unusual pathology with low incidence in the general population. They appear in the literature only as isolated case reports. True aneurysms of the infrapopliteal arteries represent a surgical problem, especially when a bifurcation is involved and when the distal vessels are affected by occlusive disease. CASE REPORT: A 67 year old man with an aneurysm which involved the tibioperoneal trunk and the origin of peroneal and posterior tibial arteries was surgical treated. At three months follow up, a duplex ultrasonography (DUS) control showed the bypass patency and the total exclusion of the aneurismal sac. DISCUSSION: Although the aneurysms of the infrapopliteal arteries are very uncommon and often asymptomatic, their associated vascular lesions and/or ischemic complications can lead to high risk of limb loss. When the aneurysm is large and/or symptomatic, the surgical treatment becomes mandatory. A conservative treatment and DUS follow up could be reserved to elderly patients and when the aneurysm is small and asymptomatic.
Asunto(s)
Aneurisma/cirugía , Arteria Poplítea/cirugía , Arterias Tibiales/cirugía , Anciano , Aneurisma/complicaciones , Aneurisma/diagnóstico por imagen , Implantación de Prótesis Vascular , Síndrome del Dedo Azul/etiología , Humanos , Masculino , Arteria Poplítea/diagnóstico por imagen , Radiografía , Vena Safena/trasplante , Arterias Tibiales/diagnóstico por imagen , UltrasonografíaRESUMEN
Cannabis is the one of the most frequently detected drug in workplace drug testing and in cases of driving under influence of drugs, and there is a greater demand for sensitive, rapid and reliable methods for confirming the presence of this drug in biological samples. This paper describes an LC-MS-MS procedure for direct analysis of cTHC and cTHC-glucuronide in urine, without hydrolysis of the samples or derivatisation. The sample preparation is very simple and consist only in a dilution of urine with methanol 1:1 (v/v) after adding the deuterated internal standard (cTHC-d3); then 10µl of the final solution is injected in LC-MS-MS. Chromatographic separation was performed using a reversed-phase column and gradient elution with 0.01% formic acid/acetonitrile/methanol and two MS-MS transitions for each substance were monitored. The method was fully validated and proved to be accurate (RSD <15%), precise (intra-day CV <10%) and sensitive with a limit of detection (LOD) of 5ng/ml for both the compounds studied. Linearity was tested in the range 5-1000ng/ml and the values of R(2) resulted >0.99. The developed method was applied to several authentic samples of urine which tested positive in the immunoassay screening and 98% of them was confirmed.
Asunto(s)
Dronabinol/análogos & derivados , Dronabinol/orina , Empleo , Fumar Marihuana , Detección de Abuso de Sustancias/métodos , Cromatografía Liquida , Humanos , Límite de Detección , Espectrometría de MasasRESUMEN
Endovascular treatment of thoracic and thoraco-abdominal aortic aneurysm with celiac artery ostium coverage, seems to be safe according to the literature. We present a case in which the endograft deployement was achieved through a right common carotid artery access because four years before the patient was submitted to an axillo-bifemoral bypass with aortic graft removal and aortic stump ligature for infection. After endovascular repair the patient suffered from spinal cord ischemia, acute pancreatitis and spleen infarction. Probably, the new pancreatic event has been triggered by temporary visceral ischemia, acting on a pancreas damaged by a previous acute hemorrhagic pancreatitis.
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Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/métodos , Arteria Carótida Común/cirugía , Arteria Celíaca/cirugía , Enfermedad Aguda , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aortografía/métodos , Implantación de Prótesis Vascular/efectos adversos , Arteria Carótida Común/diagnóstico por imagen , Arteria Celíaca/diagnóstico por imagen , Resultado Fatal , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia Multiorgánica/etiología , Pancreatitis/etiología , Isquemia de la Médula Espinal/etiología , Infarto del Bazo/etiología , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
The Notch3 gene was identified, at the beginning of 90s, as the third mammalian Notch and was initially reported as being expressed in proliferating neuroepithelium. Since then, increasing evidence has demonstrated a number of structural and functional differences between Notch3 and both Notch1 and Notch2, which exhibit the highest structural similarity among the four mammalian Notch receptors. Possibly due to its more restricted tissue distribution, targeted deletion of murine Notch3 does not lead to embryonic lethality as is observed with targeted deletion of Notch1 and Notch2. However, genetic mutation, amplification and deregulated expression of Notch3 have been correlated with the disruption of cell differentiation in transgenic mice and to development of diseases in mice and humans. This review discusses the possible relationships between the structural differences and the nonredundant roles that Notch3 plays in the pathogenesis of the human disease cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy and in the regulation of murine T-cell differentiation and leukemogenesis.
Asunto(s)
CADASIL/genética , Transformación Celular Neoplásica/genética , Leucemia Experimental/genética , Receptores Notch/fisiología , Animales , CADASIL/fisiopatología , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica , Humanos , Proteína de Unión a la Señal Recombinante J de las Inmunoglobulinas/metabolismo , Leucemia Experimental/fisiopatología , Ratones , Ratones Transgénicos , Mutación , Especificidad de Órganos , Unión Proteica , Dominios y Motivos de Interacción de Proteínas/genética , Dominios y Motivos de Interacción de Proteínas/fisiología , Receptor Notch3 , Receptores Notch/química , Receptores Notch/deficiencia , Receptores Notch/genética , Relación Estructura-Actividad , Especificidad por Sustrato , Transactivadores/metabolismo , Factores de TranscripciónRESUMEN
Several studies have highlighted that nutritional supplements may contain undeclared substances that are banned by the International Olympic Committee (IOC)/World Anti-Doping Agency (WADA). This paper describes a qualitative liquid chromatography coupled with tandem mass spectrometry detection (LC-MS/MS) method to detect anabolic androgenic steroids (4-androsten-3,17-dion, 4-oestren-3,17-dion, 5alpha-androsten-17beta-ol-3-one, boldenone, nandrolone, nandrolone decanoate, testosterone, and testosterone decanoate) and ephedrine in food supplements. The products are dissolved in methanol and analysed by gas chromatography-mass spectrometry (GC-MS). The methanolic solution was added to testosterone-d(3), evaporated to dryness, mixed with NaOH and extracted with n-pentane:diethylether (9:1). LC-MS/MS analyses were performed in selected reaction monitoring (SRM) on an ion-trap equipped with an atmospheric pressure chemical ionization (APCI) probe operating in positive-ion mode. The method was applied to 64 nutritional supplements. A total of 12.5% of the nutritional supplements analysed contained banned substances not declared on the label (anabolic steroids and ephedrine). Detection limits were in the range 1-25 ng g(-1).
Asunto(s)
Anabolizantes/análisis , Suplementos Dietéticos/análisis , Doping en los Deportes , Efedrina/análisis , Contaminación de Alimentos/análisis , Cromatografía Liquida/métodos , Análisis de los Alimentos/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Espectrometría de Masas/métodos , Reproducibilidad de los ResultadosRESUMEN
AIM: Isolated iliac artery aneurysm is a rare pathology that is often asymptomatic for long periods; this late diagnosis exposes patients to a high risk of death following aneurysm rupture. The aim of this study was to establish the most suitable diagnostic approach, the correct indications for treatment, and the most appropriate tactics and surgical technique. METHODS: Twenty-eight patients were observed over 13 years. Aneurysmal involvement was unilateral in 22 cases and bilateral in the remaining 6 patients. Preoperative diagnostic tests included eco-colour Doppler (ECD) and angio-CT in all cases, with angio-MR and angiography as more selective procedures. Seventeen patients underwent conventional open surgery with prosthetic replacement of the aneurysmatic tract, 7 patients were treated using endovascular exclusion, and lastly 4 were monitored over time. RESULTS: There was no perioperative mortality for either treatment. During the postoperative period following conventional open surgery, complications included one case of severe respiratory failure, one microembolism of the lower limb, and 2 periprosthetic hematoma. During the follow-up, we observed one pseudo-aneurysm, 3 cases of retrograde ejaculation and one patient with erectile dysfunction after traditional surgery; there was one minor endoleak after endovascular exclusion. CONCLUSIONS: Our experience suggests that ECD is a useful method for arriving at an early diagnosis, while angio-CT imaging is essential for a correct preoperative study. Aneurysms with a diameter equal or greater than 3 cm or that present annual increases in excess of 5 mm represent a correct indication for treatment. Conventional open surgery is the treatment of choice for young patients in good general conditions. Endovascular exclusion is indicated when the patient's clinical conditions contraindicate open surgery and the morphology of the aneurysmal arterial district allows the endoprosthesis to be safely implanted.
Asunto(s)
Aneurisma Ilíaco/diagnóstico , Aneurisma Ilíaco/cirugía , Procedimientos Quirúrgicos Vasculares/métodos , Anciano , Anciano de 80 o más Años , Angiografía/métodos , Implantación de Prótesis Vascular , Femenino , Estudios de Seguimiento , Humanos , Aneurisma Ilíaco/diagnóstico por imagen , Aneurisma Ilíaco/fisiopatología , Arteria Ilíaca/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Stents , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Ultrasonografía Doppler en Color , Grado de Desobstrucción Vascular , Procedimientos Quirúrgicos Vasculares/efectos adversosRESUMEN
Preschoolers' social adaptation is related to their degree of exposure to environnemental risks. However, the mechanisms through which the environmental risks operate their influence on social adaptation are still poorly documented. Thus, the first goal of this study is to investigate the main effect of family adversity on preschoolers' behavioral problems and attachment security. The second goal is to test the mediating effect of family functionning in the relationship between family adversity and behavioral problems or attachment security. Five hundred and seventy-two participants (n=572) were assessed on family adversity between the age of 5 and 42 months. Behavioral problems and family functionning were assesed at 42 months. Eighty of the participants were assessed on attachment security at the age of 48 months. The results show a main effect of family adversity on behavioral problems as well as a mediating effect of family functionning in the relationship of family adversity and behavioral problems. No significant effect was found for security of attachment.
RESUMEN
In this work the study of the disappearance of cocaine in hair is reported. The subject of the study is a woman who stopped the consumption of cocaine after a period of drug abuse of over 1 year. Hair samples were collected over a period of 10 months. During this time the absence of cocaine intake was monitored by the toxicological analysis of urine, performed every 2 days. After decontamination with methanol, the hair sample, cut in two segments (0-1.5 and 1.5-3 cm from the hair root) was added with cocaine-D(3) (internal standard), hydrolyzed and extracted with chloroform/isopropanol (9:1). The extract was evaporated to dryness, reconstituted in 25 microl of ethyl acetate and analyzed by GC-MS in SIM mode. The obtained results show that the incorporation of cocaine in hair decreased during the first 3 months after the last consumption and after this period of time no cocaine was found in the hair sections closest to the root.
Asunto(s)
Trastornos Relacionados con Cocaína/rehabilitación , Cocaína/análisis , Inhibidores de Captación de Dopamina/análisis , Cabello/química , Adulto , Cocaína/farmacocinética , Inhibidores de Captación de Dopamina/farmacocinética , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Detección de Abuso de Sustancias/métodos , Factores de TiempoRESUMEN
Zilpaterol is an adrenergic drug currently licensed in Mexico and South Africa as a feed additive for cattle close to consignment. In this study an analytical method to detect zilpaterol in commercial feeds was set up. The influence of extraction solvent and matrix was evaluated. The drug as a trimethylsilyl derivative was characterized by GC-MS, on a quadrupole detector, in the electron impact mode. Acidic extraction, solid-phase extraction C(18) non-endcapped clean-up and mass characterization on ions m/z 308, 291, 405, 390 provided zilpaterol recoveries >75.3% and repeatability <3.3% in feeds spiked in the range 30.0-120.0 ng/g. The limits of detection and quantification were 7.5 and 25.0 ng/g, respectively. Such limits are well below the dose of 5.0-20.0 microgram/g proposed as effective.
Asunto(s)
Alimentación Animal/análisis , Cromatografía de Gases y Espectrometría de Masas/métodos , Compuestos de Trimetilsililo/análisis , Animales , Bovinos , Cromatografía Líquida de Alta Presión , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
RT-PCR combined with immunoblotting showed the expression of group-I (mGlu1 and 5) and group-II (mGlu2 and 3) metabotropic glutamate receptors in whole mouse thymus, isolated thymocytes and TC-1S thymic stromal cell line. Cytofluorimetric analysis showed that mGlu-5 receptors were absent in CD4(-)/CD8(-) but present in more mature CD4(+) CD8(+) and CD4(+)CD8(-) thymocytes. mGlu-1a receptors showed an opposite pattern of expression with respect to mGlu5, whereas mGlu2/3 receptor expression did not differ between double negative and double positive cells. mGlu receptors expressed in both thymic cell components were functional, as indicated by measurements of polyphosphoinositide hydrolysis or cAMP formation. These data suggest a possible role for mGlu receptor signalling in the thymus.
Asunto(s)
Neuroinmunomodulación/genética , Receptores de Glutamato Metabotrópico/genética , Células del Estroma/inmunología , Timo/citología , Animales , Western Blotting , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/inmunología , Línea Celular , AMP Cíclico/metabolismo , Cicloleucina/análogos & derivados , Cicloleucina/farmacología , Citometría de Flujo , Expresión Génica/inmunología , Hidrólisis , Masculino , Ratones , Ratones Endogámicos C57BL , Neuroinmunomodulación/inmunología , Fármacos Neuroprotectores/farmacología , Fosfatos de Fosfatidilinositol/metabolismo , ARN Mensajero/análisis , Receptores de Glutamato Metabotrópico/agonistas , Receptores de Glutamato Metabotrópico/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/inmunología , Células del Estroma/química , Células del Estroma/citología , Timo/inmunologíaRESUMEN
The multiplicity of Notch receptors raises the question of the contribution of specific isoforms to T-cell development. Notch3 is expressed in CD4(-)8(-) thymocytes and is down-regulated across the CD4(-)8(-) to CD4(+)8(+) transition, controlled by pre-T-cell receptor signaling. To determine the effects of Notch3 on thymocyte development, transgenic mice were generated, expressing lck promoter-driven intracellular Notch3. Thymuses of young transgenics showed an increased number of thymocytes, particularly late CD4(-)8(-) cells, a failure to down-regulate CD25 in post-CD4(-)8(-) subsets and sustained activity of NF-kappaB. Subsequently, aggressive multicentric T-cell lymphomas developed with high penetrance. Tumors sustained characteristics of immature thymocytes, including expression of CD25, pTalpha and activated NF-kappaB via IKKalpha-dependent degradation of IkappaBalpha and enhancement of NF-kappaB-dependent anti-apoptotic and proliferative pathways. Together, these data identify activated Notch3 as a link between signals leading to NF-kappaB activation and T-cell tumorigenesis. The phenotypes of pre-malignant thymocytes and of lymphomas indicate a novel and particular role for Notch3 in co-ordinating growth and differentiation of thymocytes, across the pre-T/T cell transition, consistent with the normal expression pattern of Notch3.
Asunto(s)
Proteínas I-kappa B , Leucemia de Células T/metabolismo , Linfoma de Células T/metabolismo , FN-kappa B/metabolismo , Proteínas Proto-Oncogénicas/fisiología , Receptores de Superficie Celular/fisiología , Animales , Apoptosis/fisiología , Secuencia de Bases , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/citología , Supervivencia Celular , Cartilla de ADN , Proteínas de Unión al ADN/fisiología , Leucemia de Células T/patología , Linfoma de Células T/patología , Ratones , Ratones Transgénicos , Inhibidor NF-kappaB alfa , FN-kappa B/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/genética , Receptor Notch3 , Receptor Notch4 , Receptores de Superficie Celular/genética , Receptores Notch , Timo/patologíaRESUMEN
To investigate the estrogenic effects on the transcriptional regulation of the epidermal growth factor (EGF) receptor (EGFR) gene, we assayed its promoter ability to direct transcription of the luciferase reporter gene after transfection into HeLa cells. Our studies demonstrated a dose-dependent activation of the EGFR gene transcription by ligand-bound estrogen receptor alpha (ERalpha). This action was retained by the 36-bp core promoter fragment and did not require the receptor DNA binding domain, as demonstrated by analyzing the role of ERalpha deletion mutants on EGFR gene promoter-derived constructs. The 36-bp promoter fragment does not contain an estrogen response element but an imperfect thyroid hormone response element half-site that overlaps the Sp1 binding site. ERalpha does not bind this imperfect thyroid hormone response element half-site but is able to enhance binding of Sp1 to its site, in gel mobility shift assays, suggesting that the mechanism by which the receptor stimulated the transcription involved protein-protein interactions that replaced DNA binding. To explain this action, we propose a model in which induction of the EGFR gene expression by estrogens in HeLa cells is dependent upon the formation of a transcriptionally active ERalpha-Sp1 complex that binds to the GC-rich (Sp1) region of the minimal promoter.
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ADN/metabolismo , Receptores ErbB/genética , Estradiol/farmacología , Regiones Promotoras Genéticas , Receptores de Estrógenos/metabolismo , Activación Transcripcional , Sitios de Unión , Receptor alfa de Estrógeno , Eliminación de Gen , Células HeLa , Humanos , Mutagénesis , Receptores de Estrógenos/genética , Factor de Transcripción Sp1/metabolismo , Transcripción Genética , TransfecciónRESUMEN
The numerous relationships existing between the nervous and the immune systems suggest that the neural networks present in the intrathymic microenvironment may influence T-cell development. We previously reported that thymic neural-crest-derived stromal cells are involved in a neural differentiation pathway and are able to produce neurotrophic factors and neurokines that are in turn able to increase and/or modulate thymic-stromal cell neuronal phenotype. We also showed that EGF promotes a neural phenotype in thymic epithelial cells by enhancing the expression of neuronal-specific markers, neurotransmitters, and neuropoietic cytokines, such as IL-6 and CNTF. More recently we showed that the effect of EGF in directing thymic epithelial cells toward a neural-oriented cell fate is mediated by modulating the expression of genes directly involved in neurotypic differentiation (i.e., thrombospondin-1). EGF-induced regulation of stromal cells may also affect T-cell differentiation, as we observed that an EGF-pretreatment reduces the ability of thymic epithelial cells to sustain thymocyte differentiation in vitro. Finally, we demonstrated that a complex network involving the neurotrophin BDNF and its specific receptors may have a role in sustaining thymocyte precursor survival and supporting the thymocyte differentiation process. All together, our results suggest that the thymus may be the site of integration of different neuroimmune networks that are potentially involved in the regulation of thymocyte survival and/or differentiation.
Asunto(s)
Neuroinmunomodulación , Timo/fisiología , Animales , Humanos , Linfocitos T/fisiologíaRESUMEN
The suggested role of Notch1 or its mutants in thymocyte differentiation and T cell tumorigenesis raises the question of how the different members of the Notch family influence distinct steps in T cell development and the role played by Notch ligands in the thymus. We report here that different Notch receptor-ligand partnerships may occur inside the thymus, as we observed differential expression of Notch1, 2 and 3 receptors, their ligands Jagged1 and 2, and downstream intracellular effectors hairy and Enhancer of Split homolog 1 (HES-1) and hairy and Enhancer of Split homolog 5 (HES-5), depending on ontogenetic stage and thymic cell populations. Indeed, while Jagged2 is expressed in both stromal cells and thymocytes, Jagged1 expression is restricted to stromal cells. Moreover, a differential distribution of Notch3, with respect to Notch1, was observed in distinct age-related thymocyte subsets. Finally, Notch3 was preferentially up-regulated in thymocytes, following the induction of their differentiation by interaction with thymic epithelial cells expressing the cognate Jagged1 and 2 ligands, suggesting that, besides Notch1, Notch3 may also be involved in distinct steps of thymocyte development. Our results suggest that the Notch signaling pathway is involved in a complex interplay of T cell developmental stages, as a consequence of the heterogeneity and specific expression of members of the Notch receptor family and their cognate ligands, in distinct thymic cell compartments.
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Proteínas Portadoras/fisiología , Proteínas de la Membrana/fisiología , Proteínas/fisiología , Receptores de Superficie Celular/fisiología , Linfocitos T/citología , Timo/citología , Timo/metabolismo , Factores de Transcripción , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Proteínas de Unión al Calcio , Proteínas Portadoras/biosíntesis , Proteínas Portadoras/metabolismo , Diferenciación Celular/inmunología , Proteínas de Unión al ADN/biosíntesis , Secuencias Hélice-Asa-Hélice , Proteínas de Homeodominio/biosíntesis , Péptidos y Proteínas de Señalización Intercelular , Proteína Jagged-1 , Proteína Jagged-2 , Ligandos , Tejido Linfoide/citología , Tejido Linfoide/metabolismo , Masculino , Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Biosíntesis de Proteínas , Proteínas/metabolismo , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/fisiología , ARN Mensajero/biosíntesis , ARN Mensajero/metabolismo , Receptor Notch1 , Receptor Notch2 , Receptor Notch3 , Receptor Notch4 , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/metabolismo , Receptores Notch , Proteínas Represoras/biosíntesis , Proteínas Serrate-Jagged , Transducción de Señal/inmunología , Células del Estroma/metabolismo , Subgrupos de Linfocitos T/citología , Linfocitos T/metabolismo , Factor de Transcripción HES-1RESUMEN
Prostaglandins, mainly those of the E series (PGE), are modulators of immune responses. Indeed PGE2 inhibits T cell activation and the transcription of the interleukin-2 (IL-2) gene, the major T cell growth factor. We observed that PGE2 inhibits IL-2 promoter transcription activity by interfering with signals activating the (-96 to -66 bp) octamer motif. This motif binds Oct-1 and Oct-2 as well as the phorbol ester and calcium ionophore-inducible jun and fos AP-1 factors. The PGE2-dependent down-modulation is observed in the presence of either the endogenous transacting factor Oct-1 or the exogenously expressed Oct-2. PGE2 does not regulate octamer function by influencing the jun and fos mRNA or Oct-1 protein levels or their DNA-binding abilities. Functional dissection of the octamer motif, through mutations of either the AP-1 or the octamer sites, revealed that the AP-1 site is dispensable for PGE2-dependent inhibition which instead may occur through the interference with the Oct-mediated transactivation of the octamer element. Our data suggest that the Oct-octamer interaction is a novel target of the PGE2-induced down-regulation of the IL-2 promoter.
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Dinoprostona/fisiología , Regulación hacia Abajo/genética , Proteínas de Homeodominio/genética , Interleucina-2/genética , Regiones Promotoras Genéticas/inmunología , Factores de Transcripción/genética , Transcripción Genética/inmunología , Proteínas de Unión al ADN/fisiología , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/inmunología , Proteínas de Homeodominio/biosíntesis , Factor C1 de la Célula Huésped , Humanos , Interleucina-2/antagonistas & inhibidores , Células Jurkat , Factor 1 de Transcripción de Unión a Octámeros , Regiones Promotoras Genéticas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-fos/biosíntesis , Proteínas Proto-Oncogénicas c-jun/biosíntesis , Factor de Transcripción AP-1/biosíntesis , Factores de Transcripción/biosíntesis , Transcripción Genética/efectos de los fármacosRESUMEN
Both androgen and antiandrogen treatments enhance the proliferation rate of the hormone-dependent prostate cancer cell line LNCaP, expressing a mutated androgen receptor (AR). We studied the modification of the expression of epidermal growth factor (EGF), of its receptor (EGF-R), and of androgen receptor (AR) in the LNCaP cell line, under basal conditions and during androgen (R1881) and antiandrogen hydroxy-flutamide (OH-FLU) treatment. After prolonged R1881 administration, a marked increase of EGF release was observed, completely blocked by the addition of OH-FLU. The Scatchard plot analysis of EGF-R binding revealed two classes of binding sites with high and low affinity. The administration of OH-FLU alone or combined with R1881 did not modify the affinity constants, while the low-affinity component disappeared after androgen administration. Both androgen and antiandrogen administration led to a significant increase of the EGF-R high-affinity component. AR mRNA and protein levels were downregulated by R1881 treatment. Following OH-FLU administration, AR mRNA was slightly downregulated, and there was not a strict parallelism between AR mRNA levels and AR binding capacity. When combined with R1881, OH-FLU partially counteracted the androgen-induced AR downregulation. Our data show that EGF-R binding capacity is the only parameter constantly raised in cell proliferation with respect to quiescent cells, and highlights the nonunivocal action of OH-FLU on androgen-induced effects.
Asunto(s)
Factor de Crecimiento Epidérmico/biosíntesis , Receptores ErbB/biosíntesis , Flutamida/análogos & derivados , Metribolona/farmacología , Neoplasias de la Próstata/metabolismo , Receptores Androgénicos/biosíntesis , Antagonistas de Andrógenos/farmacología , Northern Blotting , Regulación hacia Abajo/efectos de los fármacos , Factor de Crecimiento Epidérmico/efectos de los fármacos , Receptores ErbB/efectos de los fármacos , Flutamida/farmacología , Expresión Génica/efectos de los fármacos , Humanos , Masculino , Metribolona/antagonistas & inhibidores , Unión Proteica , ARN Mensajero/análisis , Radioinmunoensayo , Receptores Androgénicos/efectos de los fármacos , Factores de Tiempo , Células Tumorales CultivadasRESUMEN
The differentiating agent retinoic acid (RA) has been previously reported to interfere with 12-O-tetradecanoyl-phorbol-13-acetate (TPA)/Ca2+-induced signals for the regulation of the -96 to -66-bp octamer motif found in the enhancer for the interleukin (IL)-2 gene, which encodes a major T lymphocyte growth factor. The IL-2 octamer motif is a composite cis-element which binds Oct-1 and Oct-2 as well as a TPA/Ca2+-inducible nuclear factor, previously termed octamer-associated protein (OAP40). We show here that Oct-2, despite the presence of an active transcriptional activation domain, requires TPA/Ca2+-induced signals to strongly transactivate the IL-2 octamer motif in Jurkat T cells. This Oct-2-dependent transactivation is inhibited by RA. The presence of an intact COOH-terminal domain of Oct-2 contributes to both TPA/Ca2+-induced transactivation and the RA-mediated repression. We also show that both Fos and Jun components of the AP-1 factors participate in the OAP40 complex. Furthermore, transfected c-jun, jun-B, jun-D, c-fos, or Fos-B expression vectors partially substitute for TPA and Ca2+ and cooperate with Oct-2 for the transactivation of the combined OAP/octamer cis-element. Mutations of the genuine octamer-binding site abrogate both the binding of Oct-1 and Oct-2 and the TPA/Ca2+-induced transactivation of the OAP/octamer motif. OAP confers to Oct-2 responsivity to both TPA/Ca2+ and RA, since specific mutations of the AP-1/OAP-binding site significantly reduce the transactivation by Oct-2 in response to TPA and Ca2+ and abolish the inhibition by RA. Furthermore, retinoic acid receptor (RAR) alpha is able to inhibit in vitro the formation of the complex between the nuclear AP-1/OAP and its specific binding site, resulting in the interference with Oct-2-dependent cis-regulatory function of this AP-1 element. Therefore, we propose that the TPA/calcium-activated AP-1/OAP element is the main target of positive or negative regulatory signals influencing the IL-2 octamer motif, through synergism with Oct-2 and antagonism by RAR.