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1.
Front Immunol ; 14: 1192028, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37483631

RESUMEN

Introduction: The RNA-binding protein AU-rich-element factor-1 (AUF-1) participates to posttranscriptional regulation of genes involved in inflammation and cellular senescence, two pathogenic mechanisms of chronic obstructive pulmonary disease (COPD). Decreased AUF-1 expression was described in bronchiolar epithelium of COPD patients versus controls and in vitro cytokine- and cigarette smoke-challenged human airway epithelial cells, prompting the identification of epithelial AUF-1-targeted transcripts and function, and investigation on the mechanism of its loss. Results: RNA immunoprecipitation-sequencing (RIP-Seq) identified, in the human airway epithelial cell line BEAS-2B, 494 AUF-1-bound mRNAs enriched in their 3'-untranslated regions for a Guanine-Cytosine (GC)-rich binding motif. AUF-1 association with selected transcripts and with a synthetic GC-rich motif were validated by biotin pulldown. AUF-1-targets' steady-state levels were equally affected by partial or near-total AUF-1 loss induced by cytomix (TNFα/IL1ß/IFNγ/10 nM each) and siRNA, respectively, with differential transcript decay rates. Cytomix-mediated decrease in AUF-1 levels in BEAS-2B and primary human small-airways epithelium (HSAEC) was replicated by treatment with the senescence- inducer compound etoposide and associated with readouts of cell-cycle arrest, increase in lysosomal damage and senescence-associated secretory phenotype (SASP) factors, and with AUF-1 transfer in extracellular vesicles, detected by transmission electron microscopy and immunoblotting. Extensive in-silico and genome ontology analysis found, consistent with AUF-1 functions, enriched RIP-Seq-derived AUF-1-targets in COPD-related pathways involved in inflammation, senescence, gene regulation and also in the public SASP proteome atlas; AUF-1 target signature was also significantly represented in multiple transcriptomic COPD databases generated from primary HSAEC, from lung tissue and from single-cell RNA-sequencing, displaying a predominant downregulation of expression. Discussion: Loss of intracellular AUF-1 may alter posttranscriptional regulation of targets particularly relevant for protection of genomic integrity and gene regulation, thus concurring to airway epithelial inflammatory responses related to oxidative stress and accelerated aging. Exosomal-associated AUF-1 may in turn preserve bound RNA targets and sustain their function, participating to spreading of inflammation and senescence to neighbouring cells.


Asunto(s)
Células Epiteliales , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Senescencia Celular/genética , Células Epiteliales/metabolismo , Epitelio/metabolismo , Inflamación/metabolismo , Enfermedad Pulmonar Obstructiva Crónica/patología , ARN/metabolismo , Proteínas de Unión al ARN/metabolismo
2.
Front Oncol ; 10: 1462, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32983978

RESUMEN

Tumor hypoxia represents a severe microenvironmental stress that is frequently associated with acidosis. Cancer cells respond to these stresses with changes in gene expression that promote survival at least in part through pH regulation and metabolic reprogramming. Hypoxia-induced carbonic anhydrase IX (CA IX) plays a critical adaptive role in response to hypoxic and acidic environments by catalytically hydrating extracellular CO2 to produce bicarbonate for buffering intracellular pH (pHi). We used proteome-wide profiling to study the cellular response to transient CA IX knockdown in hypoxia and found a decrease in the levels of key glycolytic enzymes and lactate dehydrogenase A (LDHA). Interestingly, the activity of LDH was also decreased as demonstrated by native in-gel activity assay. These changes led to a significant reduction in glycolytic flux and extracellular lactate levels in cancer cells in vitro, contributing to a decrease in proliferation. Interestingly, addition of the alternative LDH substrate alpha-ketobutyrate restored LDHA activity, extracellular acidification, pHi, and cellular proliferation. These results indicate that in the absence of CA IX, reduction of pHi disrupts LDHA activity and hinders the cellular capacity to regenerate NAD+ and secrete protons to the extracellular space. Hypoxia-induced CA IX therefore mediates adaptation to microenvironmental hypoxia and acidosis directly, by enzymatically converting extracellular CO2 to bicarbonate, and indirectly, by maintaining glycolysis-permissive intracellular milieu.

3.
Br J Cancer ; 120(6): 601-611, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30765875

RESUMEN

BACKGROUND: Sorafenib is the first targeted agent proven to improve survival of patients with advanced hepatocellular carcinoma (HCC) and it has been used in first line treatments with heterogeneous response across patients. Most of the promising agents evaluated in first-line or second-line phase III trials for HCC failed to improve patient survival. The absence of molecular characterisation, including the identification of pathways driving resistance might be responsible for these disappointing results. METHODS: 2D DIGE and MS analyses were used to reveal proteomic signatures resulting from Notch3 inhibition in HepG2 cells, combined with brivanib treatment. The therapeutic potential of Notch3 inhibition combined with brivanib treatment was also demonstrated in a rat model of HCC and in cell lines derived from different human cancers. RESULTS: Using a proteomic approach, we have shown that Notch3 is strongly involved in brivanib resistance through a p53-dependent regulation of enzymes of the tricarboxylic acid (TCA), both in vitro and in vivo. CONCLUSION: We have demonstrated that regulation of the TCA cycle is a common mechanism in different human cancers, suggesting that Notch3 inhibitors combined with brivanib treatment may represent a strong formulation for the treatment of HCC as well as Notch3-driven cancers.


Asunto(s)
Alanina/análogos & derivados , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/terapia , Receptor Notch3/antagonistas & inhibidores , Triazinas/farmacología , Alanina/farmacología , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Línea Celular Tumoral , Resistencia a Antineoplásicos , Electroforesis en Gel de Poliacrilamida , Técnicas de Silenciamiento del Gen , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/genética , Neoplasias Hepáticas Experimentales/terapia , Células MCF-7 , Terapia Molecular Dirigida , Proteómica , ARN Interferente Pequeño/administración & dosificación , Ratas , Ratas Wistar , Receptor Notch3/deficiencia , Receptor Notch3/genética , Electroforesis Bidimensional Diferencial en Gel
4.
Front Plant Sci ; 10: 71, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30778366

RESUMEN

Actinidia deliciosa cv. Hayward fruit is renowned for its micro- and macronutrients, which vary in their levels during berry physiological development and postharvest processing. In this context, we have recently described metabolic pathways/molecular effectors in fruit outer endocarp characterizing the different stages of berry physiological maturation. Here, we report on the kiwifruit postharvest phase through an integrated approach consisting of pomological analysis combined with NMR/LC-UV/ESI-IT-MSn- and 2D-DIGE/nanoLC-ESI-LIT-MS/MS-based proteometabolomic measurements. Kiwifruit samples stored under conventional, cold-based postharvest conditions not involving the use of dedicated chemicals were sampled at four stages (from fruit harvest to pre-commercialization) and analyzed in comparison for pomological features, and outer endocarp metabolite and protein content. About 42 metabolites were quantified, together with corresponding proteomic changes. Proteomics showed that proteins associated with disease/defense, energy, protein destination/storage, cell structure and metabolism functions were affected at precise fruit postharvest times, providing a justification to corresponding pomological/metabolite content characteristics. Bioinformatic analysis of variably represented proteins revealed a central network of interacting species, modulating metabolite level variations during postharvest fruit storage. Kiwifruit allergens were also quantified, demonstrating in some cases their highest levels at the fruit pre-commercialization stage. By lining up kiwifruit postharvest processing to a proteometabolomic depiction, this study integrates previous observations on metabolite and protein content in postharvest berries treated with specific chemical additives, and provides a reference framework for further studies on the optimization of fruit storage before its commercialization.

5.
Front Immunol ; 10: 3135, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32082304

RESUMEN

Mutual interactions between cancer cells and the tumor microenvironment importantly contribute to the development of tyrosine kinase inhibitor (TKI) resistance in patients affected by EGFR-mutant NSCLC. In particular, immune recognition-associated proteins with impact on tumor cell clearance through phagocytosis, such as CD47 and calreticulin, could contribute to adaptive resistance and immune escape. Preclinical studies targeting the anti-phagocytic CD47 molecule showed promising results in different cancer types including lung cancer, but no data are available on its role in patients acquiring resistance to EGFR TKI treatment. We analyzed the functional contribution of CD47 and calreticulin to immune surveillance and evasion in a panel of NSCLC cell lines carrying sensitizing or resistant mutations in the EGFR gene, following treatment with the TKI gefitinib and after in vitro development of gefitinib resistance. While CD47 and calreticulin protein levels were markedly variable in both EGFR-mutant and wild-type cell lines, analysis of NSCLC transcriptomic dataset revealed selective overexpression of CD47 in patients carrying EGFR mutations. EGFR inhibition significantly reduced CD47 expression on the surface of pre-apoptotic cells, favoring more efficient engulfment of cancer cells by monocyte-derived dendritic cells. This was not necessarily associated with augmented surface exposure of calreticulin or other molecular markers of immunogenic cell death. Moreover, CD47 expression became up-regulated following in vitro drug resistance development, and blocking of this protein by a specific monoclonal antibody increased the clearance of EGFR-TKI resistant cells by phagocytes. Our study supports CD47 neutralization by specific monoclonal antibody as a promising immunotherapeutic option for naïve and resistant EGFR-mutant NSCLCs.


Asunto(s)
Antígeno CD47/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Resistencia a Antineoplásicos/inmunología , Gefitinib/farmacología , Neoplasias Pulmonares/inmunología , Escape del Tumor/inmunología , Antineoplásicos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Mutación , Inhibidores de Proteínas Quinasas/farmacología
7.
J Proteomics ; 162: 86-98, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28478307

RESUMEN

Durum wheat (Triticum turgidum ssp. durum (Desf.) Husn.) is an economically important crop used for the production of semolina, which is the basis of pasta and other food products. Its grains provide proteins and starch for human consumption. Grain development is a key process in wheat physiology; it is highly affected by a number of enzymes that control the metabolic processes governing accumulation of starch and storage proteins and ultimately grain weight. Most of these enzymes are present in the albumin/globulin grain fraction, which represents about a quarter of total seed proteins. With the aim to describe the dynamic profile of the albumin/globulin fraction during durum wheat grain development, we performed a proteomic analysis of this subproteome using a two-dimensional differential gel electrophoresis (2D-DIGE)-based approach and compared six developmental stages. A total of 285 differentially (237 over- and 48 under-) represented spots was identified by nanoLC-ESI-LIT-MS/MS, which were associated with 217 non-redundant Triticum sequence entries. Quantitative protein dynamics demonstrated that carbon metabolism, energy, protein destination/storage, disease/defense and cell growth/division functional categories were highly affected during grain development, concomitantly with progressive grain size increase and starch/protein reserve accumulation. Bioinformatic interaction prediction revealed a complex network of differentially represented proteins mainly centered at enzymes involved in carbon and protein metabolism. A description of 18 proteins associated with wheat flour human allergies was also obtained; these components showed augmented levels at the last developmental stages. By providing a comprehensive understanding of the molecular basis of durum wheat grain development, yield and quality formation, this study provides the foundation and reveals potential biomarkers for further investigations of durum wheat breeding and semolina quality. BIOLOGICAL SIGNIFICANCE: A 2D-DIGE-based comparative analysis of the albumin/globulin fraction from durum wheat caryopses at six developmental stages was performed to describe the dynamic subproteomic changes associated with grain development. Quantitative variations of 217 differentially proteins demonstrated that highly affected are the functional categories of carbon metabolism, energy, protein destination/storage, disease/defense and cell growth/division, which displayed a general over-representation, consistently with concomitant occurrence of grain size increase and starch/protein reserve accumulation. Bioinformatics revealed a complex protein network centered mainly at enzymes involved in carbon and protein metabolism. Differentially represented proteins and corresponding functional categories highly resembled those previously identified as variable in developing bread wheat grain. This suggests that the main differences in kernel hardness between durum and bread wheat probably do not depend on proteomic changes in corresponding albumins/globulins, but on other specific factors affecting the interaction between the starch granules and the endosperm protein matrix in the kernel.


Asunto(s)
Albúminas/análisis , Grano Comestible/metabolismo , Globulinas/análisis , Proteoma/análisis , Triticum/metabolismo , Biología Computacional , Grano Comestible/química , Grano Comestible/crecimiento & desarrollo , Electroforesis en Gel Bidimensional , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/análisis , Proteínas de Plantas/fisiología , Espectrometría de Masas en Tándem
8.
BMC Plant Biol ; 17(1): 40, 2017 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-28183294

RESUMEN

BACKGROUND: Drought is a major constraint for plant growth and crop productivity that is receiving an increased attention due to global climate changes. Chloroplasts act as environmental sensors, however, only partial information is available on stress-induced mechanisms within plastids. Here, we investigated the chloroplast response to a severe drought treatment and a subsequent recovery cycle in tomato through physiological, metabolite and proteomic analyses. RESULTS: Under stress conditions, tomato plants showed stunted growth, and elevated levels of proline, abscisic acid (ABA) and late embryogenesis abundant gene transcript. Proteomics revealed that water deficit deeply affects chloroplast protein repertoire (31 differentially represented components), mainly involving energy-related functional species. Following the rewatering cycle, physiological parameters and metabolite levels indicated a recovery of tomato plant functions, while proteomics revealed a still ongoing adjustment of the chloroplast protein repertoire, which was even wider than during the drought phase (54 components differentially represented). Changes in gene expression of candidate genes and accumulation of ABA suggested the activation under stress of a specific chloroplast-to-nucleus (retrograde) signaling pathway and interconnection with the ABA-dependent network. CONCLUSIONS: Our results give an original overview on the role of chloroplast as enviromental sensor by both coordinating the expression of nuclear-encoded plastid-localised proteins and mediating plant stress response. Although our data suggest the activation of a specific retrograde signaling pathway and interconnection with ABA signaling network in tomato, the involvement and fine regulation of such pathway need to be further investigated through the development and characterization of ad hoc designed plant mutants.


Asunto(s)
Cloroplastos/metabolismo , Sequías , Proteínas de Plantas/metabolismo , Solanum lycopersicum/fisiología , Ácido Abscísico/metabolismo , Núcleo Celular/metabolismo , Cloroplastos/fisiología , Deshidratación , Regulación de la Expresión Génica de las Plantas , Solanum lycopersicum/metabolismo , Proteínas de Plantas/genética , Prolina/metabolismo
9.
J Proteome Res ; 15(10): 3643-3655, 2016 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-27596920

RESUMEN

Hypoxia inducible factor (HIF)-2α protein expression in solid tumors promotes stem-like phenotype in cancer stem cells and increases tumorigenic potential in nonstem cancer cells. Recently, we have shown that HIF-1/2α gene expression is correlated to neuroblastoma (NB) poor survival and to undifferentiated tumor state; HIF-2α protein was demonstrated to enhance aggressive features of the disease. In this study, we used proteomic experiments on NB cells to investigate HIF-2α downstream-regulated proteins or pathways with the aim of providing novel therapeutic targets or bad prognosis markers. We verified that pathways mostly altered by HIF-2α perturbation are involved in tumor progression. In particular, HIF-2α induces alteration of central metabolism and splicing control pathways. Simultaneously, WNT, RAS/MAPK, and PI3K/AKT activity or expression are affected and may impact the sensitivity and the intensity of HIF-2α-regulated pathways. Furthermore, genes coding the identified HIF-2α-related markers built a signature able to stratify NB patients with unfavorable outcome. Taken together, our findings underline the relevance of dissecting the downstream effects of a poor survival marker in developing targeted therapy and improving patient stratification. Future prospective studies are needed to translate the use of these data into the clinical practice.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Regulación Neoplásica de la Expresión Génica , Neuroblastoma/metabolismo , Proteómica/métodos , Biomarcadores de Tumor , Progresión de la Enfermedad , Humanos , Redes y Vías Metabólicas , Neuroblastoma/patología , Análisis de Supervivencia
10.
J Enzyme Inhib Med Chem ; 31(sup4): 45-53, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27535298

RESUMEN

The PID1/NYGGF4/PCLI1 gene encodes for a protein with a phosphotyrosine-binding domain, which interacts with the lipoprotein receptor-related protein 1. Previous work by us and others suggested a function of the gene in cell proliferation of NIH3T3 fibroblasts and 3T3-L1 pre-adipocytes. The molecular characterization of PCLI1 protein, ectopically expressed in NIH3T3 fibroblasts, revealed two phosphorylation sites at Ser154 and Ser165. In order to clarify the functions of this gene, we analyzed the effects of its downregulation on cellular proliferation and cell cycle progression in NIH3T3 cell cultures. Downregulation of PID1/NYGGF4/PCLI1 mRNA levels by short hairpin RNAs (shRNAs) elicited decreased proliferation rate in mammalian cell lines; cell cycle analysis of serum-starved, synchronized NIH3T3 fibroblasts showed an increased accumulation of shRNA-interfered cells in the G1 phase. Decreased levels of FOS and MYC mRNAs were accordingly associated with these events. The molecular scenario emerging from our data suggests that PID1/NYGGF4/PCLI1 controls cellular proliferation and cell cycle progression in NIH3T3 cells.


Asunto(s)
Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Ciclo Celular , Regulación hacia Abajo , Fibroblastos/citología , Fibroblastos/metabolismo , Animales , Proteínas Portadoras/biosíntesis , Ciclo Celular/genética , Proliferación Celular/genética , Regulación hacia Abajo/genética , Ratones , Células 3T3 NIH , Interferencia de ARN , ARN Interferente Pequeño/genética , Relación Estructura-Actividad
11.
Biomed Res Int ; 2015: 674920, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25793203

RESUMEN

Carbonic anhydrase IX (CA IX) is a surrogate marker of hypoxia, involved in survival and pH regulation in hypoxic cells. We have recently characterized its interactome, describing a set of proteins interacting with CA IX, mainly in hypoxic cells, including several members of the nucleocytoplasmic shuttling apparatuses. Accordingly, we described complex subcellular localization for this enzyme in human cells, as well as the redistribution of a carbonic anhydrase IX pool to nucleoli during hypoxia. Starting from this evidence, we analyzed the possible contribution of carbonic anhydrase IX to transcription of the 45 S rDNA genes, a process occurring in nucleoli. We highlighted the binding of carbonic anhydrase IX to nucleolar chromatin, which is regulated by oxygen levels. In fact, CA IX was found on 45 S rDNA gene promoters in normoxic cells and less represented on these sites, in hypoxic cells and in cells subjected to acetazolamide-induced acidosis. Both conditions were associated with increased representation of carbonic anhydrase IX/exportin-1 complexes in nucleoli. 45 S rRNA transcript levels were accordingly downrepresented. Inhibition of nuclear export by leptomycin B suggests a model in which exportin-1 acts as a decoy, in hypoxic cells, preventing carbonic anhydrase IX association with 45 S rDNA gene promoters.


Asunto(s)
Antígenos de Neoplasias/metabolismo , Anhidrasas Carbónicas/metabolismo , Hipoxia de la Célula/fisiología , ADN Ribosómico/metabolismo , Carioferinas/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Acidosis/genética , Acidosis/metabolismo , Antígenos de Neoplasias/genética , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Anhidrasa Carbónica IX , Anhidrasas Carbónicas/genética , Hipoxia de la Célula/genética , Línea Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , ADN Ribosómico/genética , Células HEK293 , Humanos , Carioferinas/genética , Regiones Promotoras Genéticas/efectos de los fármacos , Receptores Citoplasmáticos y Nucleares/genética , Transcripción Genética/genética , Proteína Exportina 1
12.
FASEB J ; 28(8): 3720-33, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24823364

RESUMEN

Cellular senescence is a permanent cell cycle arrest triggered by different stimuli. We recently identified up-regulation of microRNA (miR)-494 as a component of the genetic program leading to senescence of human diploid IMR90 fibroblasts. Here, we used 2-dimensional differential gel electrophoresis (2D-DIGE) coupled to mass spectrometry to profile protein expression changes induced by adoptive overexpression of miR-494 in IMR90 cells. miR-494 induced robust perturbation of the IMR90 proteome by significantly (P≤0.05) down-regulating a number of proteins. Combination of mass spectrometry-based identification of down-regulated proteins and bioinformatic prediction of the miR-494 binding sites on the relevant mRNAs identified 26 potential targets of miR-494. Among them, computational analysis identified 7 potential evolution-conserved miR-494 targets. Functional miR-494 binding sites were confirmed in 3'-untranslated regions (UTRs) of 4 of them [heterogeneous nuclear ribonucleoprotein A3 (hnRNPA3), protein disulfide isomerase A3 (PDIA3), UV excision repair protein RAD23 homolog B (RAD23B), and synaptotagmin-binding cytoplasmic RNA-interacting protein (SYNCRIP)/heterogeneous nuclear ribonucleoprotein Q (hnRNPQ)]. Their reduced expression correlated with miR-494 up-regulation in senescent cells. RNA interference-mediated knockdown of hnRNPA3 and, to a lesser extent, RAD23B mirrored the senescent phenotype induced by miR-494 overexpression, blunting cell proliferation and causing up-regulation of SA-ß-galactosidase and DNA damage. Ectopic expression of hnRNPA3 or RAD23B slowed the appearance of the senescent phenotype induced by miR-494. Overall, these findings identify novel miR-494 direct targets that are involved in cellular senescence.


Asunto(s)
Senescencia Celular/genética , Enzimas Reparadoras del ADN/biosíntesis , Proteínas de Unión al ADN/biosíntesis , Fibroblastos/citología , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B/biosíntesis , Ribonucleoproteínas Nucleares Heterogéneas/biosíntesis , MicroARNs/fisiología , Proteína Disulfuro Isomerasas/biosíntesis , Línea Celular , Senescencia Celular/fisiología , Enzimas Reparadoras del ADN/genética , Enzimas Reparadoras del ADN/fisiología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/fisiología , Electroforesis en Gel Bidimensional , Perfilación de la Expresión Génica , Células HEK293 , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B/fisiología , Ribonucleoproteínas Nucleares Heterogéneas/genética , Ribonucleoproteínas Nucleares Heterogéneas/fisiología , Humanos , Espectrometría de Masas , Proteína Disulfuro Isomerasas/genética , Proteína Disulfuro Isomerasas/fisiología , Proteoma , Interferencia de ARN , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Transfección , Regulación hacia Arriba
13.
Biol Open ; 2(10): 1070-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24167717

RESUMEN

Exploitation of embryonic stem cells (ESC) for therapeutic use and biomedical applications is severely hampered by the risk of teratocarcinoma formation. Here, we performed a screen of selected epi-modulating compounds and demonstrate that a transient exposure of mouse ESC to MS-275 (Entinostat), a class I histone deacetylase inhibitor (HDAC), modulates differentiation and prevents teratocarcinoma formation. Morphological and molecular data indicate that MS-275-primed ESCs are committed towards neural differentiation, which is supported by transcriptome analyses. Interestingly, in vitro withdrawal of MS-275 reverses the primed cells to the pluripotent state. In vivo, MS275-primed ES cells injected into recipient mice give only rise to benign teratomas but not teratocarcinomas with prevalence of neural-derived structures. In agreement, MS-275-primed ESC are unable to colonize blastocysts. These findings provide evidence that a transient alteration of acetylation alters the ESC fate.

14.
Proteomics ; 13(5): 866-77, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23281225

RESUMEN

Cetuximab is a chimeric antibody approved for the treatment of metastatic colorectal cancer that selectively targets epidermal growth factor receptor (EGFR) signaling. Treatment efficacy with this drug is often impaired by acquired resistance and poor information has been accumulated on the mechanisms underlying such a phenomenon. By taking advantage of a syngenic cellular system of sensitivity and acquired resistance to anti-EGFR therapy in the colorectal carcinoma GEO cell line, we profiled protein expression differences between Cetuximab-sensitive and -resistant cells. Combined 2D DIGE and MS analyses revealed a main proteomic signature resulting from selective deregulation of various metabolic enzymes, including glucose-6-phosphate dehydrogenase, transketolase, lactate dehydrogenase B, and pyruvate dehydrogenase E1, which was also confirmed by Western blotting experiments. Lactate dehydrogenase B downregulation has been already related to an increased anaerobic utilization of glucose by tumor cells; accordingly, we verified that Cetuximab-resistant cells have a significantly higher production of lactate. Resistant cells also showed decreased nicotinamide adenine dinucleotide phosphate (NADPH) levels. Observed protein deregulations were not related to functional alterations of the hypoxia-inducible factor 1-associated pathways. Our data demonstrate that increased anaerobic metabolism is a prominent feature observed in the GEO syngenic model of acquired resistance to anti-EGFR therapy in colorectal cancer.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Antineoplásicos/farmacología , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Anaerobiosis , Animales , Línea Celular Tumoral , Cetuximab , Resistencia a Antineoplásicos , Electroforesis en Gel Bidimensional , Humanos , Ratones , Proteoma/análisis , Proteoma/efectos de los fármacos , Proteoma/metabolismo , Proteómica , Reproducibilidad de los Resultados , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Ensayos Antitumor por Modelo de Xenoinjerto
15.
PLoS One ; 8(12): e84403, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24391952

RESUMEN

BACKGROUND: Celiac disease is an inflammatory condition of the small intestine that affects genetically predisposed individuals after dietary wheat gliadin ingestion. Type 2-transglutaminase (TG2) activity seems to be responsible for a strong autoimmune response in celiac disease, TG2 being the main autoantigen. Several studies support the concept that celiac anti-TG2 antibodies may contribute to disease pathogenesis. Our recent findings on the ability of anti-TG2 antibodies to induce a rapid intracellular mobilization of calcium ions, as well as extracellular signal-regulated kinase phosphorylation, suggest that they potentially act as signaling molecules. In line with this concept, we have investigated whether anti-TG2 antibodies can induce phosphoproteome modification in an intestinal epithelial cell line. METHODS AND PRINCIPAL FINDINGS: We studied phosphoproteome modification in Caco-2 cells treated with recombinant celiac anti-TG2 antibodies. We performed a two-dimensional electrophoresis followed by specific staining of phosphoproteins and mass spectrometry analysis of differentially phosphorylated proteins. Of 14 identified proteins (excluding two uncharacterized proteins), three were hypophosphorylated and nine were hyperphosphorylated. Bioinformatics analyses confirmed the presence of phosphorylation sites in all the identified proteins and highlighted their involvement in several fundamental biological processes, such as cell cycle progression, cell stress response, cytoskeletal organization and apoptosis. CONCLUSIONS: Identification of differentially phosphorylated proteins downstream of TG2-antibody stimulation suggests that in Caco-2 cells these antibodies perturb cell homeostasis by behaving as signaling molecules. We hypothesize that anti-TG2 autoantibodies may destabilize the integrity of the intestinal mucosa in celiac individuals, thus contributing to celiac disease establishment and progression. Since several proteins here identified in this study were already known as TG2 substrates, we can also suppose that transamidating activity and differential phosphorylation of the same targets may represent a novel regulatory mechanism whose relevance in celiac disease pathogenesis is still unexplored.


Asunto(s)
Anticuerpos/farmacología , Enfermedad Celíaca/enzimología , Proteínas de Unión al GTP/inmunología , Mucosa Intestinal/metabolismo , Fosfoproteínas/metabolismo , Transglutaminasas/inmunología , Anticuerpos/inmunología , Western Blotting , Células CACO-2 , Biología Computacional , Electroforesis en Gel Bidimensional , Humanos , Procesamiento de Imagen Asistido por Computador , Proteína Glutamina Gamma Glutamiltransferasa 2 , Proteómica
16.
J Proteome Res ; 12(1): 282-92, 2013 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-23181366

RESUMEN

Carbonic anhydrase IX (CA IX) is a transmembrane protein affecting pH regulation, cell migration/invasion, and survival in hypoxic tumors. Although the pathways related to CA IX have begun to emerge, molecular partners mediating its functions remain largely unknown. Here we characterize the CA IX interactome in hypoxic HEK-293 cells. Most of the identified CA IX-binding partners contain the HEAT/ARM repeat domain and belong to the nuclear transport machinery. We show that the interaction with two of these proteins, namely XPO1 exportin and TNPO1 importin, occurs via the C-terminal region of CA IX and increases with protein phosphorylation. We also demonstrate that nuclear CA IX is enriched in hypoxic cells and is present in renal cell carcinoma tissues. These data place CA IX among the cell-surface signal transducers undergoing nuclear translocation. Accordingly, CA IX interactome involves also CAND1, which participates in both gene transcription and assembly of SCF ubiquitin ligase complexes. It is noteworthy that down-regulation of CAND1 leads to decreased CA IX protein levels apparently via affecting its stability. Our findings provide the first evidence that CA IX interacts with proteins involved in nuclear/cytoplasmic transport, gene transcription, and protein stability, and suggest the existence of nuclear CA IX protein subpopulations with a potential intracellular function, distinct from the crucial CA IX role at the cell surface.


Asunto(s)
Antígenos de Neoplasias , Anhidrasas Carbónicas , Carcinoma de Células Renales , Proteínas , Factores de Transcripción , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Anhidrasa Carbónica IX , Anhidrasas Carbónicas/genética , Anhidrasas Carbónicas/metabolismo , Carcinoma de Células Renales/genética , Carcinoma de Células Renales/metabolismo , Carcinoma de Células Renales/patología , Hipoxia de la Célula , Células HEK293 , Humanos , Fosforilación , Mapas de Interacción de Proteínas , Estabilidad Proteica , Proteínas/química , Proteínas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
17.
J Biomed Biotechnol ; 2012: 728178, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22619496

RESUMEN

A dominant mutation in the ITM2B/BRI2 gene causes familial Danish dementia (FDD) in humans. To model FDD in animal systems, a knock-in approach was recently implemented in mice expressing a wild-type and mutant allele, which bears the FDD-associated mutation. Since these FDD(KI) mice show behavioural alterations and impaired synaptic function, we characterized their synaptosomal proteome via two-dimensional differential in-gel electrophoresis. After identification by nanoliquid chromatography coupled to electrospray-linear ion trap tandem mass spectrometry, the differentially expressed proteins were classified according to their gene ontology descriptions and their predicted functional interactions. The Dlg4/Psd95 scaffold protein and additional signalling proteins, including protein phosphatases, were revealed by STRING analysis as potential players in the altered synaptic function of FDD(KI) mice. Immunoblotting analysis finally demonstrated the actual downregulation of the synaptosomal scaffold protein Dlg4/Psd95 and of the dual-specificity phosphatase Dusp3 in the synaptosomes of FDD(KI) mice.


Asunto(s)
Catarata/metabolismo , Ataxia Cerebelosa/metabolismo , Sordera/metabolismo , Demencia/metabolismo , Modelos Animales de Enfermedad , Proteoma/análisis , Animales , Western Blotting , Electroforesis en Gel Bidimensional , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteómica , Reproducibilidad de los Resultados , Espectrometría de Masa por Ionización de Electrospray
18.
J Biomed Biotechnol ; 2011: 706746, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21960740

RESUMEN

Common variable immunodeficiency is the most common form of symptomatic primary antibody failure in adults and children. Replacement immunoglobulin is the standard treatment of these patients. By using a differential proteomic approach based on 2D-DIGE, we examined serum samples from normal donors and from matched, naive, and immunoglobulin-treated patients. The results highlighted regulated expression of serum proteins in naive patients. Among the identified proteins, clusterin/ApoJ serum levels were lower in naive patients, compared to normal subjects. This finding was validated in a wider collection of samples from newly enrolled patients. The establishment of a cellular system, based on a human hepatocyte cell line HuH7, allowed to ascertain a potential role in the regulation of CLU gene expression by immunoglobulins.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Inmunodeficiencia Variable Común/sangre , Inmunodeficiencia Variable Común/terapia , Inmunoglobulinas Intravenosas/uso terapéutico , Proteómica , Adulto , Anticuerpos/metabolismo , Proteínas Sanguíneas/genética , Línea Celular , Clusterina/genética , Clusterina/metabolismo , Femenino , Expresión Génica , Hepatocitos/metabolismo , Humanos , Inmunoglobulinas/metabolismo , Masculino
19.
Am J Infect Control ; 38(10): 799-805, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21093697

RESUMEN

BACKGROUND: The decrease in reported sharps injuries (SI) in the United States has markedly slowed. Additional devices and strategies need investigation. Sharps containers are associated with SI, and more than 90% of these injuries are related to container design. This study addresses the hypothesis that containers with enhanced engineering can reduce SI. METHODS: In a before/after intervention study from 2006 to 2008, we examined the impact of conversion to a sharps container with enhanced engineering (the Device) on SI categories in 14 Ascension Health hospitals (study group). The Device's safety features included large horizontal aperture, sensitive counterbalanced door, large atrium, and passive overfill prevention. Study group results were also compared with a control cohort of 14 contemporaneous size-matched, Ascension Health hospitals (control group). RESULTS: The Device was associated with significant reductions in after-procedure (-30%), disposal-related (-57%), and container-associated (-81%) SI in the study group. No significant reductions occurred in container-associated sharps injuries in the control group. Hospitals using the Device had significantly fewer total SI than control hospitals. CONCLUSION: Enhanced aperture design can significantly reduce container-associated sharps injuries. Other factors contributing to reduced injuries may include 1-hand deposit, safe closure, hand restriction, and preassembly. These results, from a country where sharps safety devices are widespread, are particularly applicable to countries where safety devices are not extensively used.


Asunto(s)
Accidentes de Trabajo/prevención & control , Eliminación de Residuos Sanitarios/métodos , Lesiones por Pinchazo de Aguja/prevención & control , Accidentes de Trabajo/estadística & datos numéricos , Tecnología Biomédica , Estudios de Cohortes , Diseño de Equipo , Hospitales , Estados Unidos
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