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OBJECTIVES: We investigated whether physical activity is associated with greater well-being in people with multiple long-term conditions or limiting long-term illness (LLI). STUDY DESIGN: Cross-sectional analysis of data from the Health Survey for England 2016. METHODS: The Warwick-Edinburgh mental well-being score (WEMWBS) was evaluated according to number of days per week with >30 min moderate or vigorous activity. LLI and number of long-term conditions were evaluated as effect modifiers, adjusting for age, sex, smoking, body mass index and education. Marginal effects were estimated for female non-smokers, aged 45-54 years. RESULTS: Data were analyzed for 5952 adults (female, 3275; male, 2677) including 1104 (19%) with non-limiting long-term illness and 1486 (25%) with LLI. There were 2065 (35%) with 1-2 long-term conditions, 461 (8%) with 3-4 and 58 (1%) with 5-6 long-term conditions. Participants with LLI were less likely to engage in physical activity on 5 or more days per week (LLI, 24%; No LLI, 47%) and more likely to be inactive (LLI, 41%; No LLI 13%). The adjusted marginal mean WEMWBS for inactive participants with no long-term illness was 49.0 (95% confidence interval 48.1 to 50.0), compared with 51.1 (50.4-51.8) if active on 5+ days per week. In LLI, the adjusted marginal mean WEMWBS was 41.6 (40.7-42.5) if inactive but 47.6 (46.6-48.6) if active on 5+ days per week. Similar associations were observed for the number of long-term conditions. CONCLUSIONS: Physical activity may be associated with greater increments in well-being among people with multiple long-term conditions or LLI than those without.
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Enfermedad Crónica/epidemiología , Ejercicio Físico , Estado de Salud , Adolescente , Adulto , Anciano , Índice de Masa Corporal , Estudios Transversales , Inglaterra/epidemiología , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Salud Mental , Persona de Mediana Edad , Conducta Sedentaria , Adulto JovenRESUMEN
There is interest in developing potent, selective, and cell-permeable inhibitors of human ferrous iron and 2-oxoglutarate (2OG) oxygenases for use in functional and target validation studies. The 3-component Betti reaction enables efficient one-step C-7 functionalisation of modified 8-hydroxyquinolines (8HQs) to produce cell-active inhibitors of KDM4 histone demethylases and other 2OG oxygenases; the work exemplifies how a template-based metallo-enzyme inhibitor approach can be used to give biologically active compounds.
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Inhibidores Enzimáticos/farmacología , Oxigenasas/antagonistas & inhibidores , Oxiquinolina/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estructura Molecular , Oxigenasas/metabolismo , Oxiquinolina/síntesis química , Oxiquinolina/química , Relación Estructura-ActividadRESUMEN
Correction to: Oncogene (2015) 34, 44824490; doi:10.1038/onc.2014.378; published online 24 November 2014. Following the online publication of this article, the authors have noticed a misspelt surname: S Hider should read S Haider. There is also an addition to the acknowledgements to read 'This study makes use of data generated by the Molecular Taxonomy of Breast Cancer International Consortium, which was funded by Cancer Research UK and the British Columbia Cancer Agency Branch'. The corrected article appears in this issue. The authors would like to apologise for any inconvenience this may cause.
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Activation of cellular transcriptional responses, mediated by hypoxia-inducible factor (HIF), is common in many types of cancer, and generally confers a poor prognosis. Known to induce many hundreds of protein-coding genes, HIF has also recently been shown to be a key regulator of the non-coding transcriptional response. Here, we show that NEAT1 long non-coding RNA (lncRNA) is a direct transcriptional target of HIF in many breast cancer cell lines and in solid tumors. Unlike previously described lncRNAs, NEAT1 is regulated principally by HIF-2 rather than by HIF-1. NEAT1 is a nuclear lncRNA that is an essential structural component of paraspeckles and the hypoxic induction of NEAT1 induces paraspeckle formation in a manner that is dependent upon both NEAT1 and on HIF-2. Paraspeckles are multifunction nuclear structures that sequester transcriptionally active proteins as well as RNA transcripts that have been subjected to adenosine-to-inosine (A-to-I) editing. We show that the nuclear retention of one such transcript, F11R (also known as junctional adhesion molecule 1, JAM1), in hypoxia is dependent upon the hypoxic increase in NEAT1, thereby conferring a novel mechanism of HIF-dependent gene regulation. Induction of NEAT1 in hypoxia also leads to accelerated cellular proliferation, improved clonogenic survival and reduced apoptosis, all of which are hallmarks of increased tumorigenesis. Furthermore, in patients with breast cancer, high tumor NEAT1 expression correlates with poor survival. Taken together, these results indicate a new role for HIF transcriptional pathways in the regulation of nuclear structure and that this contributes to the pro-tumorigenic hypoxia-phenotype in breast cancer.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Neoplasias de la Mama/patología , Hipoxia de la Célula , ARN Largo no Codificante/fisiología , Activación Transcripcional , Animales , Apoptosis , Neoplasias de la Mama/metabolismo , Moléculas de Adhesión Celular/genética , Proliferación Celular , Supervivencia Celular , Femenino , Humanos , Ratones , Receptores de Superficie Celular/genéticaRESUMEN
OBJECTIVE: To evaluate the agreement between OperaVOX and MDVP. DESIGN: Cross sectional reliability study. SETTING: University teaching hospital. METHODS: Fifty healthy volunteers and 50 voice disorder patients had supervised recordings in a quiet room using OperaVOX by the iPod's internal microphone with sampling rate of 45 kHz. A five-seconds recording of vowel/a/was used to measure fundamental frequency (F0), jitter, shimmer and noise-to-harmonic ratio (NHR). All healthy volunteers and 21 patients had a second recording. The recorded voices were also analysed using the MDVP. The inter- and intrasoftware reliability was analysed using intraclass correlation (ICC) test and Bland-Altman (BA) method. Mann-Whitney test was used to compare the acoustic parameters between healthy volunteers and patients. RESULTS: Nine of 50 patients had severe aperiodic voice. The ICC was high with a confidence interval of >0.75 for the inter- and intrasoftware reliability except for the NHR. For the intersoftware BA analysis, excluding the severe aperiodic voice data sets, the bias (95% LOA) of F0, jitter, shimmer and NHR was 0.81 (11.32, -9.71); -0.13 (1.26, -1.52); -0.52 (1.68, -2.72); and 0.08 (0.27, -0.10). For the intrasoftware reliability, it was -1.48 (18.43, -21.39); 0.05 (1.31, -1.21); -0.01 (2.87, -2.89); and 0.005 (0.20, -0.18), respectively. Normative data from the healthy volunteers were obtained. There was a significant difference in all acoustic parameters between volunteers and patients measured by the Opera-VOX (P < 0.001) except for F0 in females (P = 0.87). CONCLUSION: OperaVOX is comparable to MDVP and has high internal consistency for measuring the F0, jitter and shimmer of voice except for the NHR.
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Aplicaciones Móviles , Acústica del Lenguaje , Trastornos de la Voz/diagnóstico , Trastornos de la Voz/fisiopatología , Calidad de la Voz/fisiología , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores SexualesRESUMEN
In February 2008, a primary care trust in Cheshire Merseyside was notified of failures in the infection control practises of a dentist working in a large group practice. On advice from national experts, a look-back was undertaken to identify any patients infected with hepatitis followed by a notification exercise of patients who had received invasive treatment immediately afterwards. One patient with hepatitis C (HCV) was identified. Sixty patients were notified by letter and offered advice and HCV screening. The total cost of the patient notification exercise (PNE) was estimated at £85,936, equating to £1,562.47 per patient who responded to the notification (55), or £2,455.31 per patient screened (35). All results were negative. While this adds to evidence that the risk to patients in such incidents is small, failing to investigate the possibility that BBV transmission has occurred would carry public health, reputational and legal risks. Conducting a PNE in the first instance for those patients at highest risk, with the option of extending it if evidence of patient-to-patient transmission is found, ensures that the total costs of dealing appropriately with such incidents - while still substantial - are at least kept to a minimum.
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Trazado de Contacto/economía , Infección Hospitalaria/transmisión , Hepatitis C/transmisión , Control de Infección Dental , Patógenos Transmitidos por la Sangre , Costos y Análisis de Costo , Consejo/economía , Instrumentos Dentales/virología , Notificación de Enfermedades/economía , Inglaterra , Contaminación de Equipos , Personal de Salud/economía , Hepacivirus , Líneas Directas/economía , Humanos , Tamizaje Masivo/economía , Gestión de Riesgos/economía , Odontología Estatal/economíaRESUMEN
Cellular and systemic oxygen homeostasis is regulated by an oxygen-sensitive signalling pathway centred on a transcription factor known as Hypoxia Inducible Factor (HIF). Regulation of HIF activity and protein stability is mediated by a family of hydroxylases that act as oxygen sensors due to the dependence of the hydroxylation reaction on oxygen. The transcriptional activity of HIF is at least in part determined by asparaginyl hydroxylation by Factor Inhibiting HIF (FIH) of a C-terminal residue that regulates co-activator recruitment. The activity of FIH on HIF is limiting; emerging data suggest this may be due to competition from a large family of alternative FIH substrates that act as a 'sink' for FIH activity. These alternative substrates are targeted for hydroxylation at conserved Asn residues within a protein interaction domain known as the Ankyrin Repeat Domain (ARD). Many ARD-containing proteins bind to FIH more tightly than does HIF. Furthermore, ARD proteins are common within the proteome and in some cases are highly abundant. Since ARD substrates bind to FIH in a similar manner to HIF it is thought that these properties of the ARD family lead to competitive inhibition of FIH-dependent HIF hydroxylation. We summarise the current literature here and discuss the possible role of cross-talk between the FIH, HIF and ARD systems in fine tuning hypoxia responses.
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Repetición de Anquirina , Factor 1 Inducible por Hipoxia/metabolismo , Proteínas Represoras/metabolismo , Homeostasis , Humanos , Hidroxilación , Oxigenasas de Función Mixta , Oxígeno/metabolismo , Unión Proteica , Transducción de Señal/fisiologíaRESUMEN
Intracellular responses to hypoxia are coordinated by the von Hippel-Lindau--hypoxia-inducible factor (VHL-HIF) transcriptional system. This study investigated the potential role of the VHL-HIF pathway in human systems-level physiology. Patients diagnosed with Chuvash polycythaemia, a rare disorder in which VHL signalling is specifically impaired, were studied during acute hypoxia and hypercapnia. Subjects breathed through a mouthpiece and ventilation was measured while pulmonary vascular tone was assessed echocardiographically. The patients were found to have elevated basal ventilation and pulmonary vascular tone, and ventilatory, pulmonary vasoconstrictive and heart rate responses to acute hypoxia were greatly increased, as were heart rate responses to hypercapnia. The patients also had abnormal pulmonary function on spirometry. This study's findings demonstrate that the VHL-HIF signalling pathway, which is so central to intracellular oxygen sensing, also regulates the organ systems upon which cellular oxygen delivery ultimately depends.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Corazón/fisiopatología , Mutación , Policitemia/fisiopatología , Fenómenos Fisiológicos Respiratorios , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Dióxido de Carbono/sangre , Volumen Espiratorio Forzado , Humanos , Hipercapnia/genética , Hipercapnia/fisiopatología , Hipoxia/genética , Hipoxia/fisiopatología , Policitemia/genética , Valores de Referencia , Pruebas de Función Respiratoria , Transducción de SeñalRESUMEN
Inactivation of the von Hippel-Lindau tumour suppressor in renal cell carcinoma (RCC) leads to failure of proteolytic regulation of the alpha subunits of hypoxia-inducible factor (HIF), constitutive upregulation of the HIF complex, and overexpression of HIF target genes. However, recent studies have indicated that in this setting, upregulation of the closely related HIF-alpha isoforms, HIF-1alpha and HIF-2alpha, have contrasting effects on tumour growth, and activate distinct sets of target genes. To pursue these findings, we sought to elucidate the mechanisms underlying target gene selectivity for HIF-1alpha and HIF-2alpha. Using chromatin immunoprecipitation to probe binding to hypoxia response elements in vivo, and expression of chimaeric molecules bearing reciprocal domain exchanges between HIF-1alpha and HIF-2alpha molecules, we show that selective activation of HIF-alpha target gene expression is not dependent on selective DNA-binding at the target locus, but depends on non-equivalent C-terminal portions of these molecules. Our data indicate that post-DNA binding mechanisms that are dissimilar for HIF-1alpha and HIF-2alpha determine target gene selectivity in RCC cells.
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ADN/metabolismo , Regulación Neoplásica de la Expresión Génica , Neoplasias Renales/genética , Factores de Transcripción/fisiología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Inmunoprecipitación de Cromatina , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/fisiología , Factores de Transcripción/químicaRESUMEN
OBJECTIVE: To investigate the feasibility and benefits of placing dental undergraduates into a general dental practice setting for part of their clinical programme. SETTING: Two six-surgery general dental practices in the North West of England operating within the personal dental service of the NHS. METHOD: Six volunteer final year students worked within the practices for one-day-per week for 11 weeks. Evaluation included patients', practitioners' and students' views obtained from questionnaires and/or interviews and an analysis of students' clinical records. RESULTS: The students saw a large positive impact from: working alongside a dental nurse; developing their clinical skills; working in a busy practice environment; and developing interpersonal skills. Patients were very positive with 98% (44/45) being complimentary about the treatment they received, and commenting that they would be willing to participate in future student training programmes. The practice principals would also welcome continuation of the programme. CONCLUSION: The programme was both feasible and educationally beneficial. The financial implications need further research.
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Prácticas Clínicas , Servicios de Salud Dental , Educación en Odontología , Atención Individual de Salud , Actitud del Personal de Salud , Actitud Frente a la Salud , Competencia Clínica , Auditoría Odontológica , Inglaterra , Estudios de Factibilidad , Odontología General , Humanos , Relaciones Interpersonales , Administración de la Práctica Odontológica , Evaluación de Programas y Proyectos de Salud , Odontología EstatalRESUMEN
Gene expression analysis was performed on a human renal cancer cell line (786-0) with mutated VHL gene and a transfectant with wild-type VHL to analyse genes regulated by VHL and to compare with the gene programme regulated by hypoxia. There was a highly significant concordance of the global gene response to hypoxia and genes suppressed by VHL. Cyclin D1 was the most highly inducible transcript and 14-3-3 epsilon was downregulated. There were some genes regulated by VHL but not hypoxia in the renal cell line, suggesting a VHL role independent of hypoxia. However in nonrenal cell lines they were hypoxia regulated. These included several new pathways regulated by hypoxia, including RNase 6PL, collagen type 1 alpha 1, integrin alpha 5, ferritin light polypeptide, JM4 protein, transgelin and L1 cell adhesion molecule. These were not found in a recent SAGE analysis of the same cell line. Hypoxia induced downregulation of Cyclin D1 in nonrenal cells via an HIF independent pathway. The selective regulation of Cyclin D1 by hypoxia in renal cells may therefore contribute to the tissue selectivity of VHL mutation.
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Carcinoma de Células Renales/genética , Ciclina D1/farmacología , Perfilación de la Expresión Génica , Neoplasias Renales/genética , Proteínas Supresoras de Tumor/genética , Ubiquitina-Proteína Ligasas/genética , Carcinoma de Células Renales/patología , Hipoxia de la Célula , Humanos , Neoplasias Renales/patología , Células Tumorales Cultivadas , Proteína Supresora de Tumores del Síndrome de Von Hippel-LindauRESUMEN
Hypoxia and pH influence gene expression in tumours, and it is becoming increasingly clear that the pattern of genes expressed by a tumour determines its growth and survival characteristics. Hypoxia-inducible factor-1 (HIF-1) is a key mediator of the cellular response to hypoxia and high HIF-1 expression has been identified as a poor prognostic factor in tumours. Recently, we identified the tumour-associated carbonic anhydrases (CA), CA9 and CA12 as hypoxia-inducible in tumour cell lines. Furthermore, we identified CA IX to be a poor prognostic factor in breast cancer. The aim of this study was to assess the prognostic significance of CA XII. CA XII expression was studied by immunohistochemistry in a series of 103 cases of invasive breast cancer and any association with recognised prognostic factors or relation with the outcome was examined. CA XII expression was present in 77 out of 103 (75%) cases and was associated with lower grade (P=0.001), positive estrogen receptor status (P<0.001), and negative epidermal growth factor receptor status (P<0.001). Furthermore, although CA XII expression was associated with an absence of necrosis (P<0.001), expression of CA XII in some high-grade tumours was induced in regions directly adjacent to morphological necrosis. Additionally, using univariate analysis, CA XII positive tumours were associated with a lower relapse rate (P=0.04) and a better overall survival (P=0.01). In conclusion, CA XII expression is influenced both by factors related to differentiation and hypoxia in breast cancer in vivo and CA XII expression is associated with a better prognosis in an unselected series of invasive breast carcinoma patients.
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Neoplasias de la Mama/enzimología , Anhidrasas Carbónicas/análisis , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Femenino , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Pronóstico , Tasa de SupervivenciaRESUMEN
AIMS: To assess the heritability (i.e. relative contribution of genetic factors to the variability) of continuous measures of left ventricular hypertrophy determined by electrocardiography and echocardiography. METHODS AND RESULTS: We studied 955 members of 229 Caucasian families, ascertained through a hypertensive proband. Electrocardiographic measurements were performed manually on resting 12-lead electrocardiograms, and echocardiographic measurements were made on M-mode images. Sex-specific residuals for the left ventricular phenotypes were calculated, adjusted for age, systolic blood pressure, weight, height, waist-hip ratio, and presence of diabetes. Heritability was estimated in two ways: firstly, from familial correlations with adjustment for spouse resemblance; and secondly by using variance components methods with ascertainment correction for proband status. The heritability estimates (given as a range derived from the two methods) were higher for Sokolow-Lyon voltage (39-41%) than for echocardiographic left ventricular mass (23-29%). Electrocardiographic left ventricular mass, Cornell voltage, and Cornell product had heritability estimates of 12-18%, 19-25%, and 28-32%, respectively. CONCLUSIONS: Genetic factors may explain a substantial proportion of variability in quantitative electrocardiographic and echocardiographic measures of left ventricular hypertrophy. The greater heritability of Sokolow-Lyon voltage suggests that electrocardiographic phenotypes may be particularly important for the molecular investigation of the genetic susceptibility to cardiac hypertrophy.
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Hipertrofia Ventricular Izquierda/genética , Ecocardiografía/métodos , Electrocardiografía/métodos , Composición Familiar , Femenino , Humanos , Hipertrofia Ventricular Izquierda/patología , Masculino , Persona de Mediana Edad , Linaje , FenotipoRESUMEN
Helicobacter pylori (HP) is an accepted cause of chronic active gastritis and has a major causative role in peptic ulcers. It is a gastric carcinogen. Its role in nonulcer dyspepsia (NUD) is less clear, yet 50% of patients with NUD are infected with HP, and some recent literature demonstrates long-term improvement of symptoms following eradication. HP has been investigated in several other organ systems, but has not been investigated to any major degree in laryngeal disorders, a region that could be directly exposed to the bacterium from pharyngolaryngeal reflux. This study represents one arm of a larger study designed to investigate such a relationship. Of 101 patients with nonmalignant voice disorders presenting to our voice clinics, 54.5% tested positive for the H. pylori organism. Of the controls, 47.1% tested positive. When striated into age groups of < 45 years, 46-61 years, and > 62 years, and then age-matched with the controls, the likelihood of infection with the H. pylori organism was greater in both the experimental middle group, and in the middle group when combined with the elder group, than in the matched controls, and this difference demonstrated a trend approaching statistical significance. This finding is discussed in the light of other studies on HP and on gastroesophageal reflex (GER).
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Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori , Enfermedades de la Laringe/epidemiología , Enfermedades de la Laringe/microbiología , Adulto , Femenino , Reflujo Gastroesofágico/diagnóstico , Reflujo Gastroesofágico/epidemiología , Reflujo Gastroesofágico/etiología , Humanos , Enfermedades de la Laringe/complicaciones , Masculino , Persona de Mediana Edad , Prevalencia , Índice de Severidad de la Enfermedad , Trastornos de la Voz/diagnóstico , Trastornos de la Voz/epidemiología , Trastornos de la Voz/etiologíaRESUMEN
Regulation by hypoxia may underlie the expression of vascular endothelial growth factor in bladder cancer. We have compared the distribution of vascular endothelial growth factor mRNA with a hypoxia marker, carbonic anhydrase 9 (CA IX). vascular endothelial growth factor mRNA was analysed by in situ hybridisation and CA IX by immunochemistry in 22 cases of bladder cancer. The relationship of microvessels to the distribution of CA IX was determined. In a separate series of 49 superficial tumours, CA IX immunostaining was compared with clinico-pathological outcome. In superficial and invasive disease there was overlap in the expression of vascular endothelial growth factor and CA IX, CA IX being more widespread. Both were expressed predominantly on the luminal surface, and surrounding areas of necrosis (invasive tumours). Expression of both factors was greater in superficial disease. Expression was absent within approximately 80 microm of microvessels. Unlike vascular endothelial growth factor, CA IX did not predict outcome in superficial disease. Differential responses to reoxygenation provide one explanation: vascular endothelial growth factor mRNA declined rapidly, while CA IX expression was sustained for >72 h. Expression of vascular endothelial growth factor mRNA in bladder tumours is consistent with hypoxic regulation and suggests differential regulation in superficial vs invasive disease. The expression of CA IX on the luminal surface justifies investigation of its utility as a therapeutic target/prognostic indicator.
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Antígenos de Neoplasias , Anhidrasas Carbónicas/genética , Anhidrasas Carbónicas/metabolismo , Factores de Crecimiento Endotelial/genética , Factores de Crecimiento Endotelial/metabolismo , Regulación Neoplásica de la Expresión Génica , Linfocinas/genética , Linfocinas/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/patología , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Western Blotting , Anhidrasa Carbónica IX , Humanos , Inmunohistoquímica , Hibridación in Situ , Invasividad Neoplásica , Pronóstico , ARN Mensajero/genética , ARN Mensajero/metabolismo , Recurrencia , Células Tumorales Cultivadas , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/fisiopatología , Factor A de Crecimiento Endotelial Vascular , Factores de Crecimiento Endotelial VascularRESUMEN
Regulation of the growth and metabolism of large organisms is tightly constrained by the need for precise oxygen homeostasis. Work on control of the haematopoietic growth factor erythropoietin has led to the recognition of a widespread transcriptional response to hypoxia which provides insights into how this is achieved. The central mediator of this response is a DNA binding complex termed hypoxia inducible factor 1 (HIF-1), which plays a key role in the regulation by oxygen of a large and rapidly growing panel of genes. In cancer, activity of the HIF system is up-regulated both by microenvironmental hypoxia and by genetic changes. The clearest example of genetic activation is seen in the hereditary cancer syndrome von Hippel-Lindau (VHL) disease. In normal cells the product of the VHL tumour suppressor gene targets the regulatory HIF subunits (HIF-1alpha and HIF-2alpha) for oxygen-dependent proteolysis, acting as the substrate recognition component of an E3 ubiquitin ligase. In pVHL defective cells this process is blocked leading to constitutive up-regulation of HIF-1alpha subunits, activation of the HIF complex and overexpression of HIF target genes. Using gene array screens we have defined a large number of VHL-regulated genes. The majority of these show hypoxia-inducible responses, supporting the central involvement of pVHL in gene regulation by oxygen. In addition to known HIF target genes involved in angiogenesis, glucose metabolism and vasomotor control, these new targets include examples with functions in matrix metabolism, apoptosis, carbon dioxide metabolism and secondary cascades of transcriptional control. Thus activation of HIF provides insights into the classical metabolic alterations in cancer cells, and into the mechanisms by which microenvironmental hypoxia might influence tumour behaviour. In the case of VHL disease, this activation can be linked to mutations in a defined tumour suppressor gene. Equally regulation of the HIF-1alpha/pVHL interaction in normal cells should provide insights into the physiological mechanisms operating in cellular oxygen sensing.
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Proteínas de Unión al ADN/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias/genética , Proteínas Nucleares/genética , Factores de Transcripción/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Hipoxia de la Célula , Proteínas de Unión al ADN/metabolismo , Eritropoyetina/genética , Espacio Extracelular/fisiología , Secuencias Hélice-Asa-Hélice , Humanos , Factor 1 Inducible por Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia , Neoplasias/metabolismo , Neoplasias/fisiopatología , Proteínas Nucleares/metabolismo , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Enfermedad de von Hippel-Lindau/genéticaRESUMEN
BACKGROUND: The acute respiratory distress syndrome (ARDS) represents a form of severe acute inflammatory lung disease. We have previously demonstrated significantly raised interleukin-8 (IL-8) levels in the lungs of at-risk patients that progress to ARDS, and identified the alveolar macrophage as an important source of this chemokine. We wished to extend this study in a well-defined group of patients with major trauma, and to investigate potential mechanisms for rapid intrapulmonary IL-8 generation. MATERIALS AND METHODS: Patients with major trauma underwent bronchoalveolar lavage (BAL) and IL-8 levels were measured in BAL fluid by ELISA. Human macrophages were derived from peripheral blood monocytes from healthy volunteers. Rabbit alveolar macrophages were obtained from ex-vivo lavage of healthy rabbit lungs. Macrophages were culture under normoxic or hypoxic (PO2 26 mmHg) conditions. IL-8 and other proinflammatory mediator expression was measured by ELISA, northern blotting or multi-probe RNase protection assay. RESULTS: In patients with major trauma, IL-8 levels were significantly higher in patients that progressed to ARDS compared to those that did not (n = 56, P = 0.0001). High IL-8 levels negatively correlated with PaO2/FiO2 (r = -0.56, P < 0.001). In human monocyte derived macrophages hypoxia rapidly upregulated IL-8 protein (within 2 hours) and mRNA expression (within 30 mins). Acute hypoxia also increased rabbit alveolar macrophage IL-8 expression. Hypoxia increased DNA binding activity of AP-1 and C/EBP but not NF-kappaB. Hypoxia induced HIF-1 expression, but cobaltous ions and desferrioxamine did not mimic hypoxic IL-8 induction. Hypoxia downregulated a range of other proinflammatory mediators, including MCP-1 and TNF-alpha. Both the pattern of cytokine expression and transcription factor activation by hypoxia was different to that seen with endotoxin. CONCLUSIONS: Rapidly raised intrapulmonary IL-8 levels are associated with ARDS progression in patients with major trauma. Acute hypoxia, a clinically relevant stimulus, rapidly and selectively upregulates IL-8 in macrophages associated with a novel pattern of transcription factor activation. Acute hypoxia may represent one of potentially several proinflammatory stimuli responsible for rapid intrapulmonary IL-8 generation in patients at-risk of ARDS.
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Hipoxia/metabolismo , Interleucina-8/metabolismo , Macrófagos/metabolismo , Síndrome de Dificultad Respiratoria/metabolismo , Factores de Transcripción , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Northern Blotting , Líquido del Lavado Bronquioalveolar/química , Células Cultivadas , Cartilla de ADN/química , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Factor 1 Inducible por Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia , Immunoblotting , Interleucina-8/genética , Masculino , Persona de Mediana Edad , FN-kappa B/genética , FN-kappa B/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , ARN/metabolismo , Conejos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismoRESUMEN
HIF is a transcriptional complex that plays a central role in mammalian oxygen homeostasis. Recent studies have defined posttranslational modification by prolyl hydroxylation as a key regulatory event that targets HIF-alpha subunits for proteasomal destruction via the von Hippel-Lindau ubiquitylation complex. Here, we define a conserved HIF-VHL-prolyl hydroxylase pathway in C. elegans, and use a genetic approach to identify EGL-9 as a dioxygenase that regulates HIF by prolyl hydroxylation. In mammalian cells, we show that the HIF-prolyl hydroxylases are represented by a series of isoforms bearing a conserved 2-histidine-1-carboxylate iron coordination motif at the catalytic site. Direct modulation of recombinant enzyme activity by graded hypoxia, iron chelation, and cobaltous ions mirrors the characteristics of HIF induction in vivo, fulfilling requirements for these enzymes being oxygen sensors that regulate HIF.