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1.
Mol Cell ; 83(22): 4017-4031.e9, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37820732

RESUMEN

The MCM motor of the replicative helicase is loaded onto origin DNA as an inactive double hexamer before replication initiation. Recruitment of activators GINS and Cdc45 upon S-phase transition promotes the assembly of two active CMG helicases. Although work with yeast established the mechanism for origin activation, how CMG is formed in higher eukaryotes is poorly understood. Metazoan Downstream neighbor of Son (DONSON) has recently been shown to deliver GINS to MCM during CMG assembly. What impact this has on the MCM double hexamer is unknown. Here, we used cryoelectron microscopy (cryo-EM) on proteins isolated from replicating Xenopus egg extracts to identify a double CMG complex bridged by a DONSON dimer. We find that tethering elements mediating complex formation are essential for replication. DONSON reconfigures the MCM motors in the double CMG, and primordial dwarfism patients' mutations disrupting DONSON dimerization affect GINS and MCM engagement in human cells and DNA synthesis in Xenopus egg extracts.


Asunto(s)
Proteínas de Ciclo Celular , ADN Helicasas , Proteínas Nucleares , Animales , Humanos , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Microscopía por Crioelectrón , ADN/genética , ADN/metabolismo , ADN Helicasas/metabolismo , Replicación del ADN , Proteínas de Mantenimiento de Minicromosoma/genética , Proteínas de Mantenimiento de Minicromosoma/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Saccharomyces cerevisiae/genética , Activación Enzimática
2.
Genes Dev ; 33(5-6): 333-347, 2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30796017

RESUMEN

SUMOylation (small ubiquitin-like modifier) in the DNA double-strand break (DSB) response regulates recruitment, activity, and clearance of repair factors. However, our understanding of a role for deSUMOylation in this process is limited. Here we identify different mechanistic roles for deSUMOylation in homologous recombination (HR) and nonhomologous end joining (NHEJ) through the investigation of the deSUMOylase SENP2. We found that regulated deSUMOylation of MDC1 prevents excessive SUMOylation and its RNF4-VCP mediated clearance from DSBs, thereby promoting NHEJ. In contrast, we show that HR is differentially sensitive to SUMO availability and SENP2 activity is needed to provide SUMO. SENP2 is amplified as part of the chromosome 3q amplification in many cancers. Increased SENP2 expression prolongs MDC1 focus retention and increases NHEJ and radioresistance. Collectively, our data reveal that deSUMOylation differentially primes cells for responding to DSBs and demonstrates the ability of SENP2 to tune DSB repair responses.


Asunto(s)
Cisteína Endopeptidasas/metabolismo , Reparación del ADN por Unión de Extremidades/genética , Reparación del ADN/genética , Recombinación Homóloga/genética , Sumoilación/genética , Proteínas Adaptadoras Transductoras de Señales , Proteínas de Ciclo Celular , Línea Celular Tumoral , Supervivencia Celular/efectos de la radiación , Cisteína Endopeptidasas/genética , Roturas del ADN de Doble Cadena , Células HEK293 , Células HeLa , Humanos , Rayos Infrarrojos , Proteínas Nucleares/metabolismo , Tolerancia a Radiación/genética , Transducción de Señal/genética , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Proteína que Contiene Valosina/metabolismo
3.
Nature ; 571(7766): 521-527, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31270457

RESUMEN

The integrity of genomes is constantly threatened by problems encountered by the replication fork. BRCA1, BRCA2 and a subset of Fanconi anaemia proteins protect stalled replication forks from degradation by nucleases, through pathways that involve RAD51. The contribution and regulation of BRCA1 in replication fork protection, and how this role relates to its role in homologous recombination, is unclear. Here we show that BRCA1 in complex with BARD1, and not the canonical BRCA1-PALB2 interaction, is required for fork protection. BRCA1-BARD1 is regulated by a conformational change mediated by the phosphorylation-directed prolyl isomerase PIN1. PIN1 activity enhances BRCA1-BARD1 interaction with RAD51, thereby increasing the presence of RAD51 at stalled replication structures. We identify genetic variants of BRCA1-BARD1 in patients with cancer that exhibit poor protection of nascent strands but retain homologous recombination proficiency, thus defining domains of BRCA1-BARD1 that are required for fork protection and associated with cancer development. Together, these findings reveal a BRCA1-mediated pathway that governs replication fork protection.


Asunto(s)
Proteína BRCA1/química , Proteína BRCA1/metabolismo , Replicación del ADN , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Proteína BRCA1/genética , Línea Celular Tumoral , Replicación del ADN/genética , Inestabilidad Genómica/genética , Humanos , Isomerismo , Mutación , Peptidilprolil Isomerasa de Interacción con NIMA/metabolismo , Fosforilación , Fosfoserina/metabolismo , Unión Proteica , Recombinasa Rad51/metabolismo
4.
COPD ; 21(1): 2321379, 2024 12.
Artículo en Inglés | MEDLINE | ID: mdl-38655897

RESUMEN

INTRODUCTION: Spirometry is the gold standard for COPD diagnosis and severity determination, but is technique-dependent, nonspecific, and requires administration by a trained healthcare professional. There is a need for a fast, reliable, and precise alternative diagnostic test. This study's aim was to use interpretable machine learning to diagnose COPD and assess severity using 75-second carbon dioxide (CO2) breath records captured with TidalSense's N-TidalTM capnometer. METHOD: For COPD diagnosis, machine learning algorithms were trained and evaluated on 294 COPD (including GOLD stages 1-4) and 705 non-COPD participants. A logistic regression model was also trained to distinguish GOLD 1 from GOLD 4 COPD with the output probability used as an index of severity. RESULTS: The best diagnostic model achieved an AUROC of 0.890, sensitivity of 0.771, specificity of 0.850 and positive predictive value (PPV) of 0.834. Evaluating performance on all test capnograms that were confidently ruled in or out yielded PPV of 0.930 and NPV of 0.890. The severity determination model yielded an AUROC of 0.980, sensitivity of 0.958, specificity of 0.961 and PPV of 0.958 in distinguishing GOLD 1 from GOLD 4. Output probabilities from the severity determination model produced a correlation of 0.71 with percentage predicted FEV1. CONCLUSION: The N-TidalTM device could be used alongside interpretable machine learning as an accurate, point-of-care diagnostic test for COPD, particularly in primary care as a rapid rule-in or rule-out test. N-TidalTM also could be effective in monitoring disease progression, providing a possible alternative to spirometry for disease monitoring.


Asunto(s)
Capnografía , Aprendizaje Automático , Enfermedad Pulmonar Obstructiva Crónica , Índice de Severidad de la Enfermedad , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Humanos , Persona de Mediana Edad , Masculino , Femenino , Capnografía/métodos , Anciano , Modelos Logísticos , Sensibilidad y Especificidad , Volumen Espiratorio Forzado , Algoritmos , Valor Predictivo de las Pruebas , Área Bajo la Curva , Estudios de Casos y Controles , Espirometría/instrumentación
5.
Respir Res ; 24(1): 150, 2023 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-37268935

RESUMEN

BACKGROUND: Although currently most widely used in mechanical ventilation and cardiopulmonary resuscitation, features of the carbon dioxide (CO2) waveform produced through capnometry have been shown to correlate with V/Q mismatch, dead space volume, type of breathing pattern, and small airway obstruction. This study applied feature engineering and machine learning techniques to capnography data collected by the N-Tidal™ device across four clinical studies to build a classifier that could distinguish CO2 recordings (capnograms) of patients with COPD from those without COPD. METHODS: Capnography data from four longitudinal observational studies (CBRS, GBRS, CBRS2 and ABRS) was analysed from 295 patients, generating a total of 88,186 capnograms. CO2 sensor data was processed using TidalSense's regulated cloud platform, performing real-time geometric analysis on CO2 waveforms to generate 82 physiologic features per capnogram. These features were used to train machine learning classifiers to discriminate COPD from 'non-COPD' (a group that included healthy participants and those with other cardiorespiratory conditions); model performance was validated on independent test sets. RESULTS: The best machine learning model (XGBoost) performance provided a class-balanced AUROC of 0.985 ± 0.013, positive predictive value (PPV) of 0.914 ± 0.039 and sensitivity of 0.915 ± 0.066 for a diagnosis of COPD. The waveform features that are most important for driving classification are related to the alpha angle and expiratory plateau regions. These features correlated with spirometry readings, supporting their proposed properties as markers of COPD. CONCLUSION: The N-Tidal™ device can be used to accurately diagnose COPD in near-real-time, lending support to future use in a clinical setting. TRIAL REGISTRATION: Please see NCT03615365, NCT02814253, NCT04504838 and NCT03356288.


Asunto(s)
Dióxido de Carbono , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Capnografía/métodos , Volumen Espiratorio Forzado , Capacidad Vital
6.
Crit Rev Biochem Mol Biol ; 55(1): 17-32, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32069425

RESUMEN

AMP-activated protein kinase (AMPK) is a master regulator of energy homeostasis that functions to restore the energy balance by phosphorylating its substrates during altered metabolic conditions. AMPK activity is tightly controlled by diverse regulators including its upstream kinases LKB1 and CaMKK2. Recent studies have also identified the localization of AMPK at different intracellular compartments as another key mechanism for regulating AMPK signaling in response to specific stimuli. This review discusses the AMPK signaling associated with different subcellular compartments, including lysosomes, endoplasmic reticulum, mitochondria, Golgi apparatus, nucleus, and cell junctions. Because altered AMPK signaling is associated with various pathologic conditions including cancer, targeting AMPK signaling in different subcellular compartments may present attractive therapeutic approaches for treatment of disease.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/enzimología , Orgánulos/enzimología , Transducción de Señal , Quinasas de la Proteína-Quinasa Activada por el AMP , Animales , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/metabolismo , Humanos , Neoplasias/patología , Orgánulos/patología , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo
7.
Eur Heart J ; 42(37): 3844-3852, 2021 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-34269376

RESUMEN

AIMS: Fractional flow reserve (FFRCT) using computed tomography coronary angiography (CTCA) determines both the presence of coronary artery disease and vessel-specific ischaemia. We tested whether an evaluation strategy based on FFRCT would improve economic and clinical outcomes compared with standard care. METHODS AND RESULTS: Overall, 1400 patients with stable chest pain in 11 centres were randomized to initial testing with CTCA with selective FFRCT (experimental group) or standard clinical care pathways (standard group). The primary endpoint was total cardiac costs at 9 months. Secondary endpoints were angina status, quality of life, major adverse cardiac and cerebrovascular events, and use of invasive coronary angiography. Randomized groups were similar at baseline. Most patients had an initial CTCA: 439 (63%) in the standard group vs. 674 (96%) in the experimental group, 254 of whom (38%) underwent FFRCT. Mean total cardiac costs were higher by £114 (+8%) in the experimental group, with a 95% confidence interval from -£112 (-8%) to +£337 (+23%), though the difference was not significant (P = 0.10). Major adverse cardiac and cerebrovascular events did not differ significantly (10.2% in the experimental group vs. 10.6% in the standard group) and angina and quality of life improved to a similar degree over follow-up in both randomized groups. Invasive angiography was reduced significantly in the experimental group (19% vs. 25%, P = 0.01). CONCLUSION: A strategy of CTCA with selective FFRCT in patients with stable angina did not differ significantly from standard clinical care pathways in cost or clinical outcomes, but did reduce the use of invasive coronary angiography.


Asunto(s)
Angina Estable , Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Angina Estable/diagnóstico por imagen , Angina Estable/terapia , Angiografía por Tomografía Computarizada , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios , Humanos , Valor Predictivo de las Pruebas , Calidad de Vida
8.
FASEB J ; 33(2): 2957-2970, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30335546

RESUMEN

AMPK is a crucial regulator of energy homeostasis that acts downstream of its upstream kinase liver kinase B1 (LKB1) and calcium/calmodulin-dependent protein kinase 2 (CaMKK2). LKB1 primarily phosphorylates AMPK after energy stress, whereas calcium-mediated activation of AMPK requires CaMKK2, although the regulatory mechanisms of calcium-mediated AMPK activation remain unclear. Using biochemical, microscopic, and genetic approaches, we demonstrate that the stromal interaction molecule (STIM)2, a calcium sensor, acts as a novel regulator of CaMKK2-AMPK signaling. We reveal that STIM2 interacts with AMPK and CaMKK2 and that the increase in intracellular calcium levels promotes AMPK colocalization and interaction with STIM2. We further show that STIM2 deficiency attenuates calcium-induced but not energy stress-induced AMPK activation, possibly by regulating the CaMKK2-AMPK interaction. Together, our results identify a previously unappreciated mechanism that modulates calcium-mediated AMPK activation.-Chauhan, A. S., Liu, X., Jing, J., Lee, H., Yadav, R. K., Liu, J., Zhou, Y., Gan B. STIM2 interacts with AMPK and regulates calcium-induced AMPK activation.


Asunto(s)
Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/metabolismo , Calcio/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Dominios y Motivos de Interacción de Proteínas/efectos de los fármacos , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Molécula de Interacción Estromal 2/metabolismo , Quinasas de la Proteína-Quinasa Activada por el AMP , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/genética , Células HEK293 , Células HeLa , Humanos , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/genética , Molécula de Interacción Estromal 2/genética
9.
FASEB J ; 33(4): 5626-5640, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30640524

RESUMEN

During physiologic stresses, like micronutrient starvation, infection, and cancer, the cytosolic moonlighting protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is trafficked to the plasma membrane (PM) and extracellular milieu (ECM). Our work demonstrates that GAPDH mobilized to the PM, and the ECM does not utilize the classic endoplasmic reticulum-Golgi route of secretion; instead, it is first selectively translocated into early and late endosomes from the cytosol via microautophagy. GAPDH recruited to this common entry point is subsequently delivered into multivesicular bodies, leading to its membrane trafficking through secretion via exosomes and secretory lysosomes. We present evidence that both pathways of GAPDH membrane trafficking are up-regulated upon iron starvation, potentially by mobilization of intracellular calcium. These pathways also play a role in clearance of misfolded intracellular polypeptide aggregates. Our findings suggest that cells build in redundancy for vital cellular pathways to maintain micronutrient homeostasis and prevent buildup of toxic intracellular misfolded protein refuse.-Chauhan, A. S., Kumar, M., Chaudhary, S., Dhiman, A., Patidar, A., Jakhar, P., Jaswal, P., Sharma, K., Sheokand, N., Malhotra, H., Raje, C. I., Raje. M. Trafficking of a multifunctional protein by endosomal microautophagy: linking two independent unconventional secretory pathways.


Asunto(s)
Endosomas/metabolismo , Microautofagia/fisiología , Transporte de Proteínas/fisiología , Vías Secretoras/fisiología , Animales , Autofagia/fisiología , Línea Celular , Membrana Celular/metabolismo , Movimiento Celular/fisiología , Citosol/metabolismo , Retículo Endoplásmico/metabolismo , Exosomas/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Aparato de Golgi/metabolismo , Lisosomas/metabolismo , Ratones , Cuerpos Multivesiculares/metabolismo , Regulación hacia Arriba/fisiología
10.
J Med Internet Res ; 22(11): e19180, 2020 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-33180025

RESUMEN

BACKGROUND: Patients with malignant pleural mesothelioma (MPM) have a life-limiting illness and short prognosis and experience many debilitating symptoms from early in the illness. Innovations such as remote symptom monitoring are needed to enable patients to maintain wellbeing and manage symptoms in a proactive and timely manner. The Advanced Symptom Management System (ASyMS) has been successfully used to monitor symptoms associated with cancer. OBJECTIVE: This study aimed to determine the feasibility and acceptability of using an ASyMS adapted for use by patients with MPM, called ASyMSmeso, enabling the remote monitoring of symptoms using a smartphone. METHODS: This was a convergent mixed methods study using patient-reported outcome measures (PROMs) at key time points over a period of 2-3 months with 18 patients. The Sheffield Profile for Assessment and Referral for Care (SPARC), Technology Acceptance Model (TAM) measure for eHealth, and Lung Cancer Symptom Scale-Mesothelioma (LCSS-Meso) were the PROMs used in the study. Patients were also asked to complete a daily symptom questionnaire on a smartphone throughout the study. At the end of the study, semistructured interviews with 11 health professionals, 8 patients, and 3 carers were conducted to collect their experience with using ASyMSmeso. RESULTS: Eighteen patients with MPM agreed to participate in the study (33.3% response rate). The completion rates of study PROMs were high (97.2%-100%), and completion rates of the daily symptom questionnaire were also high, at 88.5%. There were no significant changes in quality of life, as measured by LCSS-Meso. There were statistically significant improvements in the SPARC psychological need domain (P=.049) and in the "Usefulness" domain of the TAM (P=.022). End-of-study interviews identified that both patients and clinicians found the system quick and easy to use. For patients, in particular, the system provided reassurance about symptom experience and the feeling of being listened to. The clinicians largely viewed the system as feasible and acceptable, and areas that were mentioned included the early management of symptoms and connectivity between patients and clinicians, leading to enhanced communication. CONCLUSIONS: This study demonstrates that remote monitoring and management of symptoms of people with MPM using a mobile phone are feasible and acceptable. The evidence supports future trials using remote symptom monitoring to support patients with MPM at home.


Asunto(s)
Mesotelioma Maligno/terapia , Calidad de Vida/psicología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Mesotelioma Maligno/mortalidad , Mesotelioma Maligno/patología , Persona de Mediana Edad , Pronóstico , Análisis de Supervivencia
11.
J Allergy Clin Immunol ; 143(2): 577-590, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-29902480

RESUMEN

BACKGROUND: Although several studies link high levels of IL-6 and soluble IL-6 receptor (sIL-6R) to asthma severity and decreased lung function, the role of IL-6 trans-signaling (IL-6TS) in asthmatic patients is unclear. OBJECTIVE: We sought to explore the association between epithelial IL-6TS pathway activation and molecular and clinical phenotypes in asthmatic patients. METHODS: An IL-6TS gene signature obtained from air-liquid interface cultures of human bronchial epithelial cells stimulated with IL-6 and sIL-6R was used to stratify lung epithelial transcriptomic data (Unbiased Biomarkers in Prediction of Respiratory Disease Outcomes [U-BIOPRED] cohorts) by means of hierarchical clustering. IL-6TS-specific protein markers were used to stratify sputum biomarker data (Wessex cohort). Molecular phenotyping was based on transcriptional profiling of epithelial brushings, pathway analysis, and immunohistochemical analysis of bronchial biopsy specimens. RESULTS: Activation of IL-6TS in air-liquid interface cultures reduced epithelial integrity and induced a specific gene signature enriched in genes associated with airway remodeling. The IL-6TS signature identified a subset of patients with IL-6TS-high asthma with increased epithelial expression of IL-6TS-inducible genes in the absence of systemic inflammation. The IL-6TS-high subset had an overrepresentation of frequent exacerbators, blood eosinophilia, and submucosal infiltration of T cells and macrophages. In bronchial brushings Toll-like receptor pathway genes were upregulated, whereas expression of cell junction genes was reduced. Sputum sIL-6R and IL-6 levels correlated with sputum markers of remodeling and innate immune activation, in particular YKL-40, matrix metalloproteinase 3, macrophage inflammatory protein 1ß, IL-8, and IL-1ß. CONCLUSIONS: Local lung epithelial IL-6TS activation in the absence of type 2 airway inflammation defines a novel subset of asthmatic patients and might drive airway inflammation and epithelial dysfunction in these patients.


Asunto(s)
Asma/inmunología , Biomarcadores/metabolismo , Células Epiteliales/fisiología , Inflamación/inmunología , Interleucina-6/metabolismo , Pulmón/fisiología , Esputo/metabolismo , Adulto , Remodelación de las Vías Aéreas (Respiratorias) , Células Cultivadas , Estudios de Cohortes , Estudios Transversales , Regulación de la Expresión Génica , Humanos , Masculino , Fenotipo , Receptores de Interleucina-6/metabolismo , Hipersensibilidad Respiratoria , Transducción de Señal , Transcriptoma
12.
Semin Cancer Biol ; 50: 65-76, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29309929

RESUMEN

FoxO transcription factors serve as the central regulator of cellular homeostasis and are tumor suppressors in human cancers. Recent studies have revealed that, besides their classic functions in promoting cell death and inducing cell cycle arrest, FoxOs also regulate cancer metabolism, an emerging hallmark of cancer. In this review, we summarize the regulatory mechanisms employed to control FoxO activities in the context of cancer biology, and discuss FoxO function in metabolism reprogramming in cancer and interaction with other key cancer metabolism pathways. A deeper understanding of FoxOs in cancer metabolism may reveal novel therapeutic opportunities in cancer treatment.


Asunto(s)
Factores de Transcripción Forkhead/genética , Redes y Vías Metabólicas/genética , Neoplasias/metabolismo , Apoptosis/genética , Factores de Transcripción Forkhead/metabolismo , Homeostasis , Humanos , Neoplasias/genética , Neoplasias/patología
13.
Thorax ; 74(4): 354-361, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30661019

RESUMEN

PURPOSE: Malignant pleural mesothelioma (MPM) has a high symptom burden and poor survival. Evidence from other cancer types suggests some benefit in health-related quality of life (HRQoL) with early specialist palliative care (SPC) integrated with oncological services, but the certainty of evidence is low. METHODS: We performed a multicentre, randomised, parallel group controlled trial comparing early referral to SPC versus standard care across 19 hospital sites in the UK and one large site in Western Australia. Participants had newly diagnosed MPM; main carers were additionally recruited. INTERVENTION: review by SPC within 3 weeks of allocation and every 4 weeks throughout the study. HRQoL was assessed at baseline and every 4 weeks with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30. PRIMARY OUTCOME: change in EORTC C30 Global Health Status 12 weeks after randomisation. RESULTS: Between April 2014 and October 2016, 174 participants were randomised. There was no significant between group difference in HRQoL score at 12 weeks (mean difference 1.8 (95% CI -4.9 to 8.5; p=0.59)). HRQoL did not differ at 24 weeks (mean difference -2.0 (95% CI -8.6 to 4.6; p=0.54)). There was no difference in depression/anxiety scores at 12 weeks or 24 weeks. In carers, there was no difference in HRQoL or mood at 12 weeks or 24 weeks, although there was a consistent preference for care, favouring the intervention arm. CONCLUSION: There is no role for routine referral to SPC soon after diagnosis of MPM for patients who are cared for in centres with good access to SPC when required. TRIAL REGISTRATION NUMBER: ISRCTN18955704.


Asunto(s)
Neoplasias Pulmonares/rehabilitación , Mesotelioma/rehabilitación , Cuidados Paliativos/organización & administración , Neoplasias Pleurales/rehabilitación , Calidad de Vida , Anciano , Cuidadores/psicología , Femenino , Humanos , Masculino , Mesotelioma Maligno , Cooperación del Paciente , Psicometría , Derivación y Consulta/organización & administración , Factores de Tiempo , Reino Unido , Australia Occidental
14.
Cell Physiol Biochem ; 52(3): 517-531, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30897319

RESUMEN

BACKGROUND/AIMS: Hypoxia triggers a rapid increase in iron demand to meet the requirements of enhanced erythropoiesis. The mobilization of iron stores from macrophage to plasma as holo-transferrin (Tf) from where it is accessible to erythroid precursor cells impacts iron homeostasis. Despite the immediate need for enhanced iron uptake by bone marrow cells, numerous studies have shown that transferrin receptor levels do not rise until more than 24 hours after the onset of hypoxia, suggesting the existence of heretofore unknown rapid response cellular machinery for iron acquisition in the early stages of cellular hypoxia. METHODS: We performed flow cytometry to measure cell surface levels of TfR1, GAPDH, and Tf binding after hypoxia treatment. We utilized FRET analysis and co-immunoprecipitation methods to establish the interaction between Tf and GAPDH. RESULTS: In the current study, we demonstrated that hypoxia induces K562 cells to translocate the cytosolic moonlighting protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH) onto cell surfaces and into the extracellular milieu to acquire transferrin-bound iron, even while levels of the classical transferrin receptor TfR1 (CD71) remain suppressed. GAPDH knockdown confirmed this protein's role in transferrin acquisition. Interestingly, macrophages did not show enhanced levels of extracellular GAPDH under hypoxia. CONCLUSION: Our results suggest the role of GAPDH-mediated Tf uptake as a rapid response mechanism by which cells acquire iron during the early stages of hypoxia. This is a tissue-specific phenomenon for the distinct requirements of cells that are consumers of iron versus cells that play a role in iron storage and recycling. This rapid deployment of an abundantly available multipurpose molecule allows hypoxic cells to internalize more Tf and maintain enhanced iron supplies in the early stages of hypoxia before specialized receptors can be synthesized and deployed to the cell membrane.


Asunto(s)
Hipoxia de la Célula , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Hierro/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Membrana Celular/metabolismo , Citosol/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/antagonistas & inhibidores , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Humanos , Células K562 , Macrófagos/citología , Macrófagos/metabolismo , Unión Proteica , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Receptores de Transferrina/genética , Receptores de Transferrina/metabolismo , Transferrina/metabolismo
15.
J Cell Sci ; 129(4): 843-53, 2016 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26743084

RESUMEN

Iron (Fe), a vital micronutrient for all organisms, must be managed judiciously because both deficiency or excess can trigger severe pathology. Although cellular Fe import is well understood, its export is thought to be limited to transmembrane extrusion through ferroportin (also known as Slc40a1), the only known mammalian Fe exporter. Utilizing primary cells and cell lines (including those with no discernible expression of ferroportin on their surface), we demonstrate that upon Fe loading, the multifunctional enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH), which is recruited to the cell surface, 'treadmills' apotransferrin in and out of the cell. Kinetic analysis utilizing labeled ligand, GAPDH-knockdown cells, (55)Fe-labeled cells and pharmacological inhibitors of endocytosis confirmed GAPDH-dependent apotransferrin internalization as a prerequisite for cellular Fe export. These studies define an unusual rapid recycling process of retroendocytosis for cellular Fe extrusion, a process mirroring receptor mediated internalization that has never before been considered for maintenance of cellular cationic homeostasis. Modulation of this unusual pathway could provide insights for management of Fe overload disorders.


Asunto(s)
Apoproteínas/metabolismo , Endocitosis , Hierro/metabolismo , Transferrina/metabolismo , Animales , Línea Celular , Ratones , Transporte de Proteínas
16.
Eur Respir J ; 52(6)2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30361247

RESUMEN

Previous publications have highlighted the disparity between research trial populations and those in clinical practice, but it has not been established how this relates to randomised controlled trials (RCTs) of phenotype-targeted biological therapies in severe asthma.Detailed characterisation data for 342 severe asthma patients within the Wessex Severe Asthma Cohort (WSAC) was compared against comprehensive trial eligibility criteria for published phase IIB and phase III RCTs evaluating biological therapies in severe asthma since 2000.37 RCTs evaluating 20 biological therapies were identified. Only a median of 9.8% (range 3.5-17.5%) of severe asthma patients were found to be eligible for enrolment in the phase III trials. Stipulations for airflow obstruction, bronchodilator reversibility and smoking history excluded significant numbers of patients. A median of 78.9% (range 73.2-86.6%) of patients with severe eosinophilic asthma would have been excluded from participation in the phase III licensing trials of interleukin (IL)-5/IL-5R targeted therapies.Despite including only well characterised and optimally treated severe asthmatics under specialist care within the WSAC study, the vast majority were excluded from trial participation by criteria designed to re-confirm diagnostic labels rather than by biomarker criteria that predict the characteristic addressed by the treatment.


Asunto(s)
Asma/terapia , Selección de Paciente , Fenotipo , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Adulto , Antiasmáticos/uso terapéutico , Asma/fisiopatología , Terapia Biológica , Biomarcadores , Broncodilatadores/uso terapéutico , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Estudios Transversales , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad
17.
FASEB J ; 31(6): 2638-2648, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28298336

RESUMEN

Prokaryotic pathogens establish infection in mammals by capturing the proteolytic enzyme plasminogen (Plg) onto their surface to digest host extracellular matrix (ECM). One of the bacterial surface Plg receptors is the multifunctional glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In a defensive response, the host mounts an inflammatory response, which involves infiltration of leukocytes to sites of inflammation. This requires macrophage exit from the blood and migration across basement membranes, a phenomenon dependent on proteolytic remodeling of the ECM utilizing Plg. The ability of Plg to facilitate inflammatory cell recruitment critically depends on receptors on the surface of phagocyte cells. Utilizing a combination of biochemical, cellular, knockdown, and in vivo approaches, we demonstrated that upon inflammation, macrophages recruit GAPDH onto their surface to carry out the same task of capturing Plg to digest ECM to aid rapid phagocyte migration and combat the invading pathogens. We propose that GAPDH is an ancient, evolutionarily conserved receptor that plays a key role in the Plg-dependent regulation of macrophage recruitment in the inflammatory response to microbial aggression, thus pitting prokaryotic GAPDH against mammalian GAPDH, with both involved in a conserved role of Plg activation on the surface of their respective cells, to conflicting ends.-Chauhan, A. S., Kumar, M., Chaudhary, S., Patidar, A., Dhiman, A., Sheokand, N., Malhotra, H., Raje, C. I., Raje, M. Moonlighting glycolytic protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH): an evolutionarily conserved plasminogen receptor on mammalian cells.


Asunto(s)
Evolución Molecular , Gliceraldehído-3-Fosfato Deshidrogenasa (Fosforilante)/metabolismo , Macrófagos/metabolismo , Plasminógeno/metabolismo , Animales , Línea Celular , Movimiento Celular , Regulación Enzimológica de la Expresión Génica/fisiología , Gliceraldehído-3-Fosfato Deshidrogenasa (Fosforilante)/genética , Ratones , Receptores de Superficie Celular , Receptores del Activador de Plasminógeno Tipo Uroquinasa/genética , Receptores del Activador de Plasminógeno Tipo Uroquinasa/metabolismo , Regulación hacia Arriba
18.
J Allergy Clin Immunol ; 138(1): 61-75, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-26851968

RESUMEN

BACKGROUND: Disease heterogeneity in patients with severe asthma and its relationship to inflammatory mechanisms remain poorly understood. OBJECTIVE: We aimed to identify and replicate clinicopathologic endotypes based on analysis of blood and sputum parameters in asthmatic patients. METHODS: One hundred ninety-four asthmatic patients and 21 control subjects recruited from 2 separate centers underwent detailed clinical assessment, sputum induction, and phlebotomy. One hundred three clinical, physiologic, and inflammatory parameters were analyzed by using topological data analysis and Bayesian network analysis. RESULTS: Severe asthma was associated with anxiety and depression, obesity, sinonasal symptoms, decreased quality of life, and inflammatory changes, including increased sputum chitinase 3-like protein 1 (YKL-40) and matrix metalloproteinase (MMP) 1, 3, 8, and 12 levels. Topological data analysis identified 6 clinicopathobiologic clusters replicated in both geographic cohorts: young, mild paucigranulocytic; older, sinonasal disease; obese, high MMP levels; steroid resistant TH2 mediated, eosinophilic; mixed granulocytic with severe obstruction; and neutrophilic, low periostin levels, severe obstruction. Sputum IL-5 levels were increased in patients with severe particularly eosinophilic forms, whereas IL-13 was suppressed and IL-17 levels did not differ between clusters. Bayesian network analysis separated clinical features from intricately connected inflammatory pathways. YKL-40 levels strongly correlated with neutrophilic asthma and levels of myeloperoxidase, IL-8, IL-6, and IL-6 soluble receptor. MMP1, MMP3, MMP8, and MMP12 levels were associated with severe asthma and were correlated positively with sputum IL-5 levels but negatively with IL-13 levels. CONCLUSION: In 2 distinct cohorts we have identified and replicated 6 clinicopathobiologic clusters based on blood and induced sputum measures. Our data underline a disconnect between clinical features and underlying inflammation, suggest IL-5 production is relatively steroid insensitive, and highlight the expression of YKL-40 in patients with neutrophilic inflammation and the expression of MMPs in patients with severe asthma.


Asunto(s)
Asma/diagnóstico , Asma/metabolismo , Proteína 1 Similar a Quitinasa-3/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Adulto , Anciano , Asma/tratamiento farmacológico , Teorema de Bayes , Biomarcadores , Estudios de Casos y Controles , Citocinas/metabolismo , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Masculino , Inhibidores de la Metaloproteinasa de la Matriz/metabolismo , Persona de Mediana Edad , Pruebas de Función Respiratoria , Factores de Riesgo , Índice de Severidad de la Enfermedad , Esputo/metabolismo , Adulto Joven
19.
J Cell Sci ; 127(Pt 19): 4279-91, 2014 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-25074810

RESUMEN

Iron (Fe(2+), Fe(3+)) homeostasis is a tightly regulated process, involving precise control of iron influx and egress from cells. Although the mechanisms of its import into cells by iron carrier molecules are well characterized, iron export remains poorly understood. The current paradigm envisages unique functions associated with specialized macromolecules for its cellular import (transferrin receptors) or export (ferroportin, also known as SLC40A1). Previous studies have revealed that iron-depleted cells recruit glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a multitasking, 'moonlighting' protein, to their surface for internalization of the iron carrier holotransferrin. Here, we report that under the converse condition of intracellular iron excess, cells switch the isoform of GAPDH on their surface to one that now recruits iron-free apotransferrin in close association with ferroportin to facilitate the efflux of iron. Increased expression of surface GAPDH correlated with increased apotransferrin binding and enhanced iron export from cells, a capability lost in GAPDH-knockdown cells. These findings were confirmed in vivo utilizing a rodent model of iron overload. Besides identifying for the first time an apotransferrin receptor, our work uncovers the two-way switching of multifunctional molecules to manage cellular micronutrient requirements.


Asunto(s)
Apoproteínas/metabolismo , Compuestos Férricos/metabolismo , Compuestos Ferrosos/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Transferrina/metabolismo , Animales , Humanos , Conejos , Ratas , Ratas Sprague-Dawley
20.
JAMA ; 314(24): 2641-53, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26720026

RESUMEN

IMPORTANCE: For treatment of malignant pleural effusion, nonsteroidal anti-inflammatory drugs (NSAIDs) are avoided because they may reduce pleurodesis efficacy. Smaller chest tubes may be less painful than larger tubes, but efficacy in pleurodesis has not been proven. OBJECTIVE: To assess the effect of chest tube size and analgesia (NSAIDs vs opiates) on pain and clinical efficacy related to pleurodesis in patients with malignant pleural effusion. DESIGN, SETTING, AND PARTICIPANTS: A 2×2 factorial phase 3 randomized clinical trial among 320 patients requiring pleurodesis in 16 UK hospitals from 2007 to 2013. INTERVENTIONS: Patients undergoing thoracoscopy (n = 206; clinical decision if biopsy was required) received a 24F chest tube and were randomized to receive opiates (n = 103) vs NSAIDs (n = 103), and those not undergoing thoracoscopy (n = 114) were randomized to 1 of 4 groups (24F chest tube and opioids [n = 28]; 24F chest tube and NSAIDs [n = 29]; 12F chest tube and opioids [n = 29]; or 12F chest tube and NSAIDs [n = 28]). MAIN OUTCOMES AND MEASURES: Pain while chest tube was in place (0- to 100-mm visual analog scale [VAS] 4 times/d; superiority comparison) and pleurodesis efficacy at 3 months (failure defined as need for further pleural intervention; noninferiority comparison; margin, 15%). RESULTS: Pain scores in the opiate group (n = 150) vs the NSAID group (n = 144) were not significantly different (mean VAS score, 23.8 mm vs 22.1 mm; adjusted difference, -1.5 mm; 95% CI, -5.0 to 2.0 mm; P = .40), but the NSAID group required more rescue analgesia (26.3% vs 38.1%; rate ratio, 2.1; 95% CI, 1.3-3.4; P = .003). Pleurodesis failure occurred in 30 patients (20%) in the opiate group and 33 (23%) in the NSAID group, meeting criteria for noninferiority (difference, -3%; 1-sided 95% CI, -10% to ∞; P = .004 for noninferiority). Pain scores were lower among patients in the 12F chest tube group (n = 54) vs the 24F group (n = 56) (mean VAS score, 22.0 mm vs 26.8 mm; adjusted difference, -6.0 mm; 95% CI, -11.7 to -0.2 mm; P = .04) and 12F chest tubes vs 24F chest tubes were associated with higher pleurodesis failure (30% vs 24%), failing to meet noninferiority criteria (difference, -6%; 1-sided 95% CI, -20% to ∞; P = .14 for noninferiority). Complications during chest tube insertion occurred more commonly with 12F tubes (14% vs 24%; odds ratio, 1.91; P = .20). CONCLUSIONS AND RELEVANCE: Use of NSAIDs vs opiates resulted in no significant difference in pain scores but was associated with more rescue medication. NSAID use resulted in noninferior rates of pleurodesis efficacy at 3 months. Placement of 12F chest tubes vs 24F chest tubes was associated with a statistically significant but clinically modest reduction in pain but failed to meet noninferiority criteria for pleurodesis efficacy. TRIAL REGISTRATION: isrctn.org Identifier: ISRCTN33288337.


Asunto(s)
Analgésicos Opioides/uso terapéutico , Antiinflamatorios no Esteroideos/uso terapéutico , Tubos Torácicos/efectos adversos , Manejo del Dolor/métodos , Derrame Pleural Maligno/terapia , Pleurodesia/métodos , Anciano , Algoritmos , Analgesia/métodos , Analgésicos Opioides/efectos adversos , Antiinflamatorios no Esteroideos/efectos adversos , Intervalos de Confianza , Diseño de Equipo , Femenino , Humanos , Masculino , Dimensión del Dolor/métodos , Derrame Pleural Maligno/complicaciones , Terapia Recuperativa/métodos , Terapia Recuperativa/estadística & datos numéricos , Toracoscopía/instrumentación , Insuficiencia del Tratamiento
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