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1.
Appl Opt ; 63(7): 1839-1846, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38437288

RESUMEN

The spectral information contained in the reflective imaging bands can be exploited for specific tasks. Whether targeting or mapping, the visible (VIS), near-infrared (NIR), shortwave infrared (SWIR), extended shortwave infrared (eSWIR) bands perform very differently for every application. For any imaging project, high contrast is very important for good imagery. High contrast leads to more recognizable features within a scene and easier identifiable objects. For mapping, good background scene contrast gives prominent features more detail and their locations can be easily identified. For targeting, low background scene contrast reduces clutter, making it easier to detect objects of interest. The VIS, NIR, SWIR, and eSWIR bands are popular reflective bands to design daytime imaging systems for either task. Deciding on which band will have the best contrast for a specific task is one of the first things to study when designing an imaging system. By measuring urban and rural scenes in terms of equivalent reflectivity (ER), a direct comparison of these four bands can show the utility they provide. The systems used to measure scene contrast are designed to have the same spatial resolution and field of view (FOV). With these instantaneous FOV (IFOV) matched systems, the variance and 1D power spectral densities (PSDs) provide a quantitative comparison for the contrast among the four bands. The ER differences and resulting contrast measured among these four bands show that the eSWIR has the highest contrast in both urban and rural scenes.

2.
Opt Express ; 30(1): 563-575, 2022 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-35201231

RESUMEN

The signal to noise ratio and corresponding visibility of power cables as seen by military aircrafts is critical for crew safety. During low altitude operations, rotorcraft systems must be able to navigate these power lines during flight. Many of these military missions are flown at night which means the reflective bands including the visible, near infrared and short-wave infrared do not provide sufficient light. However, the emissive bands of the mid-wave infrared (MWIR) and long-wave infrared (LWIR) can be used to distinguish the location of these wires. LWIR sensors are typically used for pilotage applications. In both the LWIR and MWIR, the signal to noise depends on the wire emissivity and reflectivity as well as the ground and sky background path radiance. The signal to noise ratio is strongly dependent on the elevation of the viewing angle. In this paper, we model the signal to noise ratio as a function of elevation viewing angle using wire reflectivity and emissivity as well as MODTRAN calculations for path radiance. We also take MWIR and LWIR measurements to compare these two bands to the modelling results. We provide a summary of both model and measurements and make conclusions.

3.
J Gambl Stud ; 37(2): 529-549, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32410048

RESUMEN

The prevalence of gambling harm among active duty military personnel is a largely unexplored topic. With different forms of social gambling often found within (or in close proximity to) military bases around the world, understanding the extent of gambling activities and consequent harms occurring within military contexts warrants further attention. This review aims to identify, describe and thematically synthesise published literature on gambling harm and related issues among active duty military personnel. Scoping review methods were applied in order to understand this relatively under-researched population and understand appropriate avenues for future research. A systematic multi-database text word search, incorporating search results from Scopus, Pubmed, Web of Science, PsychInfo, and the Journal Military Medicine, was conducted. A total of 11 sources met inclusion criteria, all originating from the United States of America. The results suggest a distinct gap in the current international literature on this topic. Despite gambling's long and colourful association with defence downtime, research into gambling harm prevalence rates in relation to what could be considered a high-risk group is limited. Findings reveal that strategies to identify and address gambling harm within this population are severely lacking from the published literature and non-existent outside North America. Implications for understanding and addressing gambling harm among active duty personnel and directions for future research are discussed.


Asunto(s)
Conducta Adictiva/psicología , Juego de Azar/psicología , Salud Militar/estadística & datos numéricos , Personal Militar/psicología , Conducta Adictiva/epidemiología , Juego de Azar/epidemiología , Humanos , Personal Militar/estadística & datos numéricos , Prevalencia , Estados Unidos
4.
Sensors (Basel) ; 21(21)2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34770382

RESUMEN

Atmospheric path radiance in the infrared is an extremely important quantity in calculating system performance in certain infrared detection systems. For infrared search and track (IRST) system performance calculations, the path radiance competes with the target for precious detector well electrons. In addition, the radiance differential between the target and the path radiance defines the signal level that must be detected. Long-range, high-performance, offensive IRST system design depends on accurate path radiance predictions. In addition, in new applications such as drone detection where a dim unresolved target is embedded into a path radiance background, sensor design and performance are highly dependent on atmospheric path radiance. Being able to predict the performance of these systems under particular weather conditions and locations has long been an important topic. MODTRAN has been a critical tool in the analysis of systems and prediction of electro-optical system performance. The authors have used MODTRAN over many years for an average system performance using the typical "pull-down" conditions in the software. This article considers the level of refinement required for a custom MODTRAN atmosphere profile to satisfactorily model an infrared camera's performance for a specific geographic location, date, and time. The average difference between a measured sky brightness temperature and a MODTRAN predicted value is less than 0.5 °C with sufficient atmosphere profile updates. The agreement between experimental results and MODTRAN predictions indicates the effectiveness of including updated atmospheric composition, radiosonde, and air quality data from readily available Internet sources to generate custom atmosphere profiles.


Asunto(s)
Contaminación del Aire , Atmósfera , Atmósfera/análisis , Programas Informáticos , Temperatura
5.
FASEB J ; 32(7): 3892-3902, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29465311

RESUMEN

Sustained endoplasmic reticulum (ER) stress plays a major role in the development of many metabolic diseases, including cardiovascular disease, nonalcoholic fatty liver disease, insulin resistance, obesity, and diabetes. p32 is a multicompartmental protein involved in the regulation of oxidative phosphorylation and glucose oxidation. p32 ablation is associated with resistance to age-associated and diet-induced obesity through a mechanism that remains largely unknown. Here, we show that p32 promotes lipid biosynthesis by modulating fatty acid-induced ER stress. We found that p32 interacts with endoplasmic reticulum-anchored enzyme mannosyl-oligosaccharide glucosidase I (GCS1), an ER lumen-anchored glucosidase that is essential for the processing of N-linked glycoproteins, and reduces GCS1 in a lysosome-dependent manner. We demonstrate that increased GCS1 expression alleviates fatty acid-induced ER stress and is critical for suppressing ER stress-associated lipogenic gene activation, as demonstrated by the down-regulation of Srebp1, Fasn, and Acc. Consistently, suppression of p32 leads to increased GCS1 expression and alleviates fatty acid-induced ER stress, resulting in reduced lipid accumulation. Thus, p32 and GCS1 are regulators of ER function and lipid homeostasis and are potential therapeutic targets for the treatment of obesity and diabetes.-Liu, Y., Leslie, P. L., Jin, A., Itahana, K., Graves, L. M., Zhang, Y. p32 regulates ER stress and lipid homeostasis by down-regulating GCS1 expression.


Asunto(s)
Estrés del Retículo Endoplásmico , Metabolismo de los Lípidos , Proteínas Mitocondriales/metabolismo , alfa-Glucosidasas/metabolismo , Células 3T3 , Acetil-CoA Carboxilasa/genética , Acetil-CoA Carboxilasa/metabolismo , Animales , Línea Celular Tumoral , Células Cultivadas , Regulación hacia Abajo , Acido Graso Sintasa Tipo I/genética , Acido Graso Sintasa Tipo I/metabolismo , Homeostasis , Humanos , Ratones , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , alfa-Glucosidasas/genética
6.
Proc Natl Acad Sci U S A ; 111(23): E2414-22, 2014 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-24872453

RESUMEN

The tumor suppressor p53 has recently been shown to regulate energy metabolism through multiple mechanisms. However, the in vivo signaling pathways related to p53-mediated metabolic regulation remain largely uncharacterized. By using mice bearing a single amino acid substitution at cysteine residue 305 of mouse double minute 2 (Mdm2(C305F)), which renders Mdm2 deficient in binding ribosomal proteins (RPs) RPL11 and RPL5, we show that the RP-Mdm2-p53 signaling pathway is critical for sensing nutrient deprivation and maintaining liver lipid homeostasis. Although the Mdm2(C305F) mutation does not significantly affect growth and development in mice, this mutation promotes fat accumulation under normal feeding conditions and hepatosteatosis under acute fasting conditions. We show that nutrient deprivation inhibits rRNA biosynthesis, increases RP-Mdm2 interaction, and induces p53-mediated transactivation of malonyl-CoA decarboxylase (MCD), which catalyzes the degradation of malonyl-CoA to acetyl-CoA, thus modulating lipid partitioning. Fasted Mdm2(C305F) mice demonstrate attenuated MCD induction and enhanced malonyl-CoA accumulation in addition to decreased oxidative respiration and increased fatty acid accumulation in the liver. Thus, the RP-Mdm2-p53 pathway appears to function as an endogenous sensor responsible for stimulating fatty acid oxidation in response to nutrient depletion.


Asunto(s)
Fenómenos Fisiológicos Nutricionales de los Animales/fisiología , Carboxiliasas/metabolismo , Ácidos Grasos/metabolismo , Metabolismo de los Lípidos/fisiología , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Ribosómicas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Células Cultivadas , Embrión de Mamíferos/citología , Ayuno , Hígado Graso/genética , Hígado Graso/fisiopatología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Immunoblotting , Metabolismo de los Lípidos/genética , Ratones , Ratones Noqueados , Análisis de Secuencia por Matrices de Oligonucleótidos , Oxidación-Reducción , Unión Proteica , Proteínas Proto-Oncogénicas c-mdm2/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estrés Fisiológico/fisiología , Tamoxifeno/análogos & derivados , Tamoxifeno/farmacología , Transcriptoma/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética , Pérdida de Peso/genética , Pérdida de Peso/fisiología
7.
J Biol Chem ; 290(20): 12941-50, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25809483

RESUMEN

The oncoprotein murine double minute 2 (MDM2) is an E3 ligase that plays a prominent role in p53 suppression by promoting its polyubiquitination and proteasomal degradation. In its active form, MDM2 forms homodimers as well as heterodimers with the homologous protein murine double minute 4 (MDMX), both of which are thought to occur through their respective C-terminal RING (really interesting new gene) domains. In this study, using multiple MDM2 mutants, we show evidence suggesting that MDM2 homo- and heterodimerization occur through distinct mechanisms because MDM2 RING domain mutations that inhibit MDM2 interaction with MDMX do not affect MDM2 interaction with WT MDM2. Intriguingly, deletion of a portion of the MDM2 central acidic domain selectively inhibits interaction with MDM2 while leaving intact the ability of MDM2 to interact with MDMX and to ubiquitinate p53. Further analysis of an MDM2 C-terminal deletion mutant reveals that the C-terminal residues of MDM2 are required for both MDM2 and MDMX interaction. Collectively, our results suggest a model in which MDM2-MDMX heterodimerization requires the extreme C terminus and proper RING domain structure of MDM2, whereas MDM2 homodimerization requires the extreme C terminus and the central acidic domain of MDM2, suggesting that MDM2 homo- and heterodimers utilize distinct MDM2 domains. Our study is the first to report mutations capable of separating MDM2 homo- and heterodimerization.


Asunto(s)
Modelos Biológicos , Proteínas Nucleares/metabolismo , Multimerización de Proteína/fisiología , Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Secuencia de Aminoácidos , Proteínas de Ciclo Celular , Línea Celular Tumoral , Humanos , Proteínas Nucleares/genética , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-mdm2/genética , Eliminación de Secuencia , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Ubiquitinación/fisiología
8.
Trends Cancer ; 7(3): 226-239, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33199193

RESUMEN

The tumor-suppressor protein p53 is mutated in approximately half of all cancers, whereas the p53 signaling network is perturbed in almost all cancers. In response to different stress stimuli, p53 selectively activates genes to elicit a cell survival or cell death response. How p53 makes the decision between life and death remains a fascinating question and an exciting field of research. Understanding how this decision is made has major implications for improving cancer treatments, particularly in recently evolved immune checkpoint inhibition therapy. We highlight progress and challenges in understanding the mechanisms governing the p53 life and death decision-making process, and discuss how this decision is relevant to immune system regulation. Finally, we discuss how knowledge of the p53 pro-survival and pro-death decision node can be applied to optimize immune checkpoint inhibitor therapy for cancer treatment.


Asunto(s)
Inhibidores de Puntos de Control Inmunológico/farmacología , Muerte Celular Inmunogénica/efectos de los fármacos , Inmunoterapia Adoptiva/métodos , Neoplasias/terapia , Proteína p53 Supresora de Tumor/metabolismo , Animales , Antígenos de Neoplasias/genética , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/genética , Supervivencia Celular/inmunología , Daño del ADN , Reparación del ADN/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/inmunología , Humanos , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Muerte Celular Inmunogénica/genética , Ratones , MicroARNs/metabolismo , Mutación , Neoplasias/genética , Neoplasias/inmunología , Procesamiento Proteico-Postraduccional , Receptores Quiméricos de Antígenos/inmunología , Proteína p53 Supresora de Tumor/genética
9.
Nat Commun ; 10(1): 4192, 2019 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-31519896

RESUMEN

Lymph node (LN) metastases correspond with a worse prognosis in nearly all cancers, yet the occurrence of cancer spreading from LNs remains controversial. Additionally, the mechanisms explaining how cancers survive and exit LNs are largely unknown. Here, we show that breast cancer patients frequently have LN metastases that closely resemble distant metastases. In addition, using a microsurgical model, we show how LN metastasis development and dissemination is regulated by the expression of a chromatin modifier, histone deacetylase 11 (HDAC11). Genetic and pharmacologic blockade of HDAC11 decreases LN tumor growth, yet substantially increases migration and distant metastasis formation. Collectively, we reveal a mechanism explaining how HDAC11 plasticity promotes breast cancer growth as well as dissemination from LNs and suggest caution with the use of HDAC inhibitors.


Asunto(s)
Neoplasias de la Mama/metabolismo , Histona Desacetilasas/metabolismo , Ganglios Linfáticos/metabolismo , Animales , Western Blotting , Neoplasias de la Mama/genética , Línea Celular Tumoral , Movimiento Celular/genética , Movimiento Celular/fisiología , Inmunoprecipitación de Cromatina , Metilación de ADN/genética , Metilación de ADN/fisiología , Citometría de Flujo , Células HEK293 , Histona Desacetilasas/genética , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Reacción en Cadena en Tiempo Real de la Polimerasa
10.
Oncogene ; 38(26): 5191-5210, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30918328

RESUMEN

Angiogenesis is critical to cancer development and metastasis. However, anti-angiogenic agents have only had modest therapeutic success, partly due to an incomplete understanding of tumor endothelial cell (EC) biology. We previously reported that the microRNA (miR)-200 family inhibits metastasis through regulation of tumor angiogenesis, but the underlying molecular mechanisms are poorly characterized. Here, using integrated bioinformatics approaches, we identified the RNA-binding protein (RBP) quaking (QKI) as a leading miR-200b endothelial target with previously unappreciated roles in the tumor microenvironment in lung cancer. In lung cancer samples, both miR-200b suppression and QKI overexpression corresponded with tumor ECs relative to normal ECs, and QKI silencing phenocopied miR-200b-mediated inhibition of sprouting. Additionally, both cancer cell and endothelial QKI expression in patient samples significantly corresponded with poor survival and correlated with angiogenic indices. QKI supported EC function by stabilizing cyclin D1 (CCND1) mRNA to promote EC G1/S cell cycle transition and proliferation. Both nanoparticle-mediated RNA interference of endothelial QKI expression and palbociclib blockade of CCND1 function potently inhibited metastasis in concert with significant effects on tumor vasculature. Altogether, this work demonstrates the clinical relevance and therapeutic potential of a novel, actionable miR/RBP axis in tumor angiogenesis and metastasis.


Asunto(s)
Ciclo Celular/genética , Redes Reguladoras de Genes/genética , Células Endoteliales de la Vena Umbilical Humana/fisiología , Neoplasias/patología , Neovascularización Patológica/genética , Proteínas de Unión al ARN/fisiología , Animales , Ciclo Celular/fisiología , Movimiento Celular/genética , Proliferación Celular/genética , Células Cultivadas , Ciclina D1/genética , Progresión de la Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Células HEK293 , Humanos , Ratones , Ratones Desnudos , Metástasis de la Neoplasia/genética , Neoplasias/irrigación sanguínea , Neoplasias/genética , Neovascularización Patológica/patología , Interferencia de ARN/fisiología
11.
Cell Rep ; 24(6): 1484-1495, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-30089260

RESUMEN

Understanding how p53 activates certain gene programs and not others is critical. Here, we identify low-density lipoprotein receptor-related protein 1 (LRP1), a transmembrane endocytic receptor, as a p53 target gene. We show that, although LRP1 transcript expression is upregulated in response to both sub-lethal and lethal doses of p53-activating stress, LRP1 protein is only upregulated in response to sub-lethal stress. Interestingly, lethal doses of p53-activating stress inhibit LRP1 de novo translation through an miRNA-based translational repression mechanism. We show that the p53-regulated miRNAs miR-103 and miR-107 are significantly upregulated by lethal doses of stress, resulting in suppression of LRP1 translation and cell death. Our results define a negative feedback loop involving the p53-regulated coding gene LRP1 and p53-regulated miRNA genes. These findings provide mechanistic insight into the selective expression of p53 target genes in response to different stress intensities to elicit either cell survival or cell death.


Asunto(s)
Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , MicroARNs/genética , Proteína p53 Supresora de Tumor/metabolismo , Apoptosis , Humanos , Transfección
12.
Nat Commun ; 9(1): 1988, 2018 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-29777108

RESUMEN

Lung cancer is the leading cause of cancer-related deaths worldwide, and lung squamous carcinomas (LUSC) represent about 30% of cases. Molecular aberrations in lung adenocarcinomas have allowed for effective targeted treatments, but corresponding therapeutic advances in LUSC have not materialized. However, immune checkpoint inhibitors in sub-populations of LUSC patients have led to exciting responses. Using computational analyses of The Cancer Genome Atlas, we identified a subset of LUSC tumors characterized by dense infiltration of inflammatory monocytes (IMs) and poor survival. With novel, immunocompetent metastasis models, we demonstrated that tumor cell derived CCL2-mediated recruitment of IMs is necessary and sufficient for LUSC metastasis. Pharmacologic inhibition of IM recruitment had substantial anti-metastatic effects. Notably, we show that IMs highly express Factor XIIIA, which promotes fibrin cross-linking to create a scaffold for LUSC cell invasion and metastases. Consistently, human LUSC samples containing extensive cross-linked fibrin in the microenvironment correlated with poor survival.


Asunto(s)
Carcinoma de Células Escamosas/inmunología , Factor XIIIa/inmunología , Fibrina/química , Neoplasias Pulmonares/inmunología , Monocitos/inmunología , Animales , Biomarcadores de Tumor/química , Biomarcadores de Tumor/inmunología , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Quimiocina CCL2/genética , Quimiocina CCL2/inmunología , Factor XIIIa/genética , Femenino , Fibrina/inmunología , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Masculino , Ratones , Ratones Endogámicos DBA , Invasividad Neoplásica
13.
Sci Rep ; 7(1): 5754, 2017 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-28720899

RESUMEN

Obesity is increasing in prevalence and has become a global public health problem. The main cause of obesity is a perturbation in energy homeostasis, whereby energy intake exceeds energy expenditure. Although mitochondrial dysfunction has been linked to the deregulation of energy homeostasis, the precise mechanism is poorly understood. Here, we identify mitochondrial p32 (also known as C1QBP) as an important regulator of lipid homeostasis that regulates both aerobic and anaerobic energy metabolism. We show that while whole-body deletion of the p32 results in an embryonic lethal phenotype, mice heterozygous for p32 are resistant to age- and high-fat diet-induced ailments, including obesity, hyperglycemia, and hepatosteatosis. Notably, p32 +/- mice are apparently healthy, demonstrate an increased lean-to-fat ratio, and show dramatically improved insulin sensitivity despite prolonged high-fat diet feeding. The p32 +/- mice show increased oxygen consumption and heat production, indicating that they expend more energy. Our analysis revealed that haploinsufficiency for p32 impairs glucose oxidation, which results in a compensatory increase in fatty acid oxidation and glycolysis. These metabolic alterations increase both aerobic and anaerobic energy expenditure. Collectively, our data show that p32 plays a critical role in energy homeostasis and represents a potential novel target for the development of anti-obesity drugs.


Asunto(s)
Metabolismo Energético/genética , Hiperglucemia/genética , Proteínas Mitocondriales/genética , Obesidad/genética , Animales , Dieta Alta en Grasa/efectos adversos , Ingestión de Energía/genética , Glucólisis/genética , Heterocigoto , Homeostasis/genética , Hiperglucemia/etiología , Hiperglucemia/metabolismo , Resistencia a la Insulina/genética , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Mitocondriales/metabolismo , Obesidad/etiología , Obesidad/metabolismo , Consumo de Oxígeno/genética
14.
Sci Rep ; 6: 38067, 2016 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-27901115

RESUMEN

Activation of p53 in response to DNA damage is essential for tumor suppression. Although previous studies have emphasized the importance of p53-dependent cell cycle arrest and apoptosis for tumor suppression, recent studies have suggested that other areas of p53 regulation, such as metabolism and DNA damage repair (DDR), are also essential for p53-dependent tumor suppression. However, the intrinsic connections between p53-mediated DDR and metabolic regulation remain incompletely understood. Here, we present data suggesting that p53 promotes nucleotide biosynthesis in response to DNA damage by repressing the expression of the phosphofructokinase-2 (PFK2) isoform 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a rate-limiting enzyme that promotes glycolysis. PFKFB3 suppression increases the flux of glucose through the pentose phosphate pathway (PPP) to increase nucleotide production, which results in more efficient DNA damage repair and increased cell survival. Interestingly, although p53-mediated suppression of PFKFB3 could increase the two major PPP products, NADPH and nucleotides, only nucleotide production was essential to promote DDR. By identifying the novel p53 target PFKFB3, we report an important mechanistic connection between p53-regulated metabolism and DDR, both of which play crucial roles in tumor suppression.


Asunto(s)
Reparación del ADN , Glucosa/metabolismo , Nucleósidos/biosíntesis , Vía de Pentosa Fosfato , Fosfofructoquinasa-2/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Línea Celular Tumoral , Glucosa/genética , Humanos , Nucleósidos/genética , Fosfofructoquinasa-2/genética , Proteína p53 Supresora de Tumor/genética
15.
Arthritis Rheumatol ; 67(11): 2978-89, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26200652

RESUMEN

OBJECTIVE: Glycans attached to the Fc portion of IgG are important modulators of IgG effector functions. Interindividual differences in IgG glycome composition are large and they associate strongly with different inflammatory and autoimmune diseases. IKZF1, HLA-DQ2A/B, and BACH2 genetic loci that affect IgG glycome composition show pleiotropy with systemic lupus erythematosus (SLE), indicating a potentially causative role of aberrant IgG glycosylation in SLE. We undertook this large multicenter case-control study to determine whether SLE is associated with altered IgG glycosylation. METHODS: Using ultra-performance liquid chromatography analysis of released glycans, we analyzed the composition of the IgG glycome in 261 SLE patients and 247 matched controls of Latin American Mestizo origin (the discovery cohort) and in 2 independent replication cohorts of different ethnicity (108 SLE patients and 193 controls from Trinidad, and 106 SLE patients and 105 controls from China). RESULTS: Multiple statistically significant differences in IgG glycome composition were observed between patients and controls. The most significant changes included decreased galactosylation and sialylation of IgG (which regulate proinflammatory and antiinflammatory actions of IgG) as well as decreased core fucose and increased bisecting N-acetylglucosamine (which affect antibody-dependent cell-mediated cytotoxicity). CONCLUSION: The IgG glycome in SLE patients is significantly altered in a way that decreases immunosuppressive action of circulating immunoglobulins. The magnitude of observed changes is associated with the intensity of the disease, indicating that aberrant IgG glycome composition or changes in IgG glycosylation may be an important molecular mechanism in SLE.


Asunto(s)
Predisposición Genética a la Enfermedad , Inmunoglobulina G/genética , Lupus Eritematoso Sistémico/inmunología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina G/metabolismo , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/metabolismo , Masculino , Persona de Mediana Edad , Adulto Joven
16.
Springerplus ; 3: 80, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24570851

RESUMEN

Stem cells have emerged as important players in the generation and maintenance of many tissues. However, the accurate in vitro simulation of the native stem cell niche remains difficult due at least in part to the lack of a comprehensive definition of the critical factors of the stem cell niche based on in vivo models. Three-dimensional (3D) cell culture systems have allowed the development of useful models for investigating stem cell physiology particularly with respect to their ability to sense and generate mechanical force in response to their surrounding environment. We review the use of 3D culture systems for stem cell culture and discuss the relationship between stem cells and 3D growth matrices including the roles of the extracellular matrix, scaffolds, soluble factors, cell-cell interactions and shear stress effects within this environment. We also discuss the potential for novel methods that mimic the native stem cell niche in vitro as well as the current associated challenges.

17.
Oncotarget ; 5(4): 860-71, 2014 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-24658219

RESUMEN

Ribosomal proteins (RPs) have gained much attention for their extraribosomal functions particularly with respect to p53 regulation. To date, about fourteen RPs have shown to bind to MDM2 and regulate p53. Upon binding to MDM2, the RPs suppress MDM2 E3 ubiquitin ligase activity resulting in the stabilization and activation of p53. Of the RPs that bind to MDM2, RPL5 and RPL11 are the most studied and RPL11 appears to have the most significant role in p53 regulation. Considering that more than 17% of RP species have been shown to interact with MDM2, one of the questions remains unresolved is why so many RPs bind MDM2 and modulate p53. Genes encoding RPs are widely dispersed on different chromosomes in both mice and humans. As components of ribosome, RP expression is tightly regulated to meet the appropriate stoichiometric ratio between RPs and rRNAs. Once genomic instability (e.g. aneuploidy) occurs, transcriptional and translational changes due to change of DNA copy number can result in an imbalance in the expression of RPs including those that bind to MDM2. Such an imbalance in RP expression could lead to failure to assemble functional ribosomes resulting in ribosomal stress. We propose that RPs have evolved ability to regulate MDM2 in response to genomic instability as an additional layer of p53 regulation. Full understanding of the biological roles of RPs could potentially establish RPs as a novel class of therapeutic targets in human diseases such as cancer.


Asunto(s)
Proteínas Proto-Oncogénicas c-mdm2/metabolismo , Proteínas Ribosómicas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Línea Celular Tumoral , Inestabilidad Genómica , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-mdm2/genética , Proteínas Ribosómicas/genética , Proteína p53 Supresora de Tumor/genética
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