Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
Más filtros

Base de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Int J Cardiol ; 383: 8-14, 2023 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-37085119

RESUMEN

BACKGROUND: Revascularization of left main coronary artery (LMCA) stenosis is mostly based on angiography. Indices based on angiography might increase accuracy of the decision, although they have been scarcely used in LMCA. The objective of this study is to study the diagnostic agreement of QFR (quantitative flow ratio) with wire-based fractional flow reserve (FFR) in LMCA lesions and to compare with visual severity assessment. METHODS: In a series of patients with invasive FFR assessment of intermediate LMCA stenoses we retrospectively compared the measured value of QFR with that of FFR and the estimate of significance from angiography. RESULTS: 107 QFR studies were included. The QFR intra-observer and inter-observer agreement was 87% and 82% respectively. The mean QFR-FFR difference was 0.047 ± 0.05 with a concordance of 90.7%, sensitivity 88.1%, specificity 92.3%, positive predictive value 88.1% and negative predictive value 92.3%. All these values were superior to those observed with the visual estimation which showed an intra- and inter-observer agreement of 73% and 72% respectively, besides 78% with the FFR value. The low diagnostic performance of the visual estimation and the acceptable performance of the QFR index measurement were observed in all subgroups analysed. CONCLUSIONS: QFR allows an acceptable estimate of the FFR obtained with intracoronary pressure guidewire in intermediate LMCA lesions, and clearly superior to the assessment based on angiography alone. The decision to revascularize patients with moderate LMCA lesions should not be based solely on the degree of angiographic stenosis.


Asunto(s)
Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Humanos , Vasos Coronarios/diagnóstico por imagen , Constricción Patológica , Estudios Retrospectivos , Angiografía Coronaria , Índice de Severidad de la Enfermedad , Estenosis Coronaria/diagnóstico por imagen , Estenosis Coronaria/cirugía , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/cirugía
2.
Cancers (Basel) ; 14(16)2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-36010852

RESUMEN

There is a great need for non-invasive tools that inform of an early molecular response to cancer therapeutic treatment. Here, we tested the hypothesis that proteolytically resistant proteins could be candidate circulating tumor biomarkers for cancer therapy. Proteins resistant to proteolysis are drastically under-sampled by current proteomic workflows. These proteins could be reliable sensors for the response to therapy since they are likely to stay longer in circulation. We selected manganese superoxide dismutase (SOD2), a mitochondrial redox enzyme, from a screening of proteolytic resistant proteins in breast cancer (BC). First, we confirmed the robustness of SOD2 and determined that its proteolytic resistance is mediated by its quaternary protein structure. We also proved that the release of SOD2 upon chemotherapy treatment correlates with cell death in BC cells. Then, after confirming that SOD2 is very stable in human serum, we sought to measure its circulating levels in a cohort of BC patients undergoing neoadjuvant therapy. The results showed that circulating levels of SOD2 increased when patients responded to the treatment according to the tumor shrinkage during neoadjuvant chemotherapy. Therefore, the measurement of SOD2 levels in plasma could improve the non-invasive monitoring of the therapeutic treatment in breast cancer patients. The identification of circulating biomarkers linked to the tumor cell death induced by treatment could be useful for monitoring the action of the large number of cancer drugs currently used in clinics. We envision that our approach could help uncover candidate tumor biomarkers to measure a tumor's response to cancer therapy in real time by sampling the tumor throughout the course of treatment.

3.
Nature ; 607(7920): 756-761, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35859172

RESUMEN

Oocytes form before birth and remain viable for several decades before fertilization1. Although poor oocyte quality accounts for most female fertility problems, little is known about how oocytes maintain cellular fitness, or why their quality eventually declines with age2. Reactive oxygen species (ROS) produced as by-products of mitochondrial activity are associated with lower rates of fertilization and embryo survival3-5. Yet, how healthy oocytes balance essential mitochondrial activity with the production of ROS is unknown. Here we show that oocytes evade ROS by remodelling the mitochondrial electron transport chain through elimination of complex I. Combining live-cell imaging and proteomics in human and Xenopus oocytes, we find that early oocytes exhibit greatly reduced levels of complex I. This is accompanied by a highly active mitochondrial unfolded protein response, which is indicative of an imbalanced electron transport chain. Biochemical and functional assays confirm that complex I is neither assembled nor active in early oocytes. Thus, we report a physiological cell type without complex I in animals. Our findings also clarify why patients with complex-I-related hereditary mitochondrial diseases do not experience subfertility. Complex I suppression represents an evolutionarily conserved strategy that allows longevity while maintaining biological activity in long-lived oocytes.


Asunto(s)
Complejo I de Transporte de Electrón , Mitocondrias , Oocitos , Especies Reactivas de Oxígeno , Animales , Transporte de Electrón , Complejo I de Transporte de Electrón/antagonistas & inhibidores , Complejo I de Transporte de Electrón/metabolismo , Femenino , Humanos , Mitocondrias/metabolismo , Oocitos/citología , Oocitos/enzimología , Oocitos/metabolismo , Proteómica , Respuesta de Proteína Desplegada , Xenopus laevis
4.
J Cell Sci ; 135(1)2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34897463

RESUMEN

Oocytes spend the majority of their lifetime in a primordial state. The cellular and molecular biology of primordial oocytes is largely unexplored; yet, it is necessary to study them to understand the mechanisms through which oocytes maintain cellular fitness for decades, and why they eventually fail with age. Here, we develop enabling methods for live-imaging-based comparative characterization of Xenopus, mouse and human primordial oocytes. We show that primordial oocytes in all three vertebrate species contain active mitochondria, Golgi and lysosomes. We further demonstrate that human and Xenopus oocytes have a Balbiani body characterized by a dense accumulation of mitochondria in their cytoplasm. However, despite previous reports, we did not find a Balbiani body in mouse oocytes. Instead, we demonstrate that what was previously used as a marker for the Balbiani body in mouse primordial oocytes is in fact a ring-shaped Golgi that is not functionally associated with oocyte dormancy. This study provides the first insights into the organization of the cytoplasm in mammalian primordial oocytes, and clarifies the relative advantages and limitations of choosing different model organisms for studying oocyte dormancy.


Asunto(s)
Oocitos , Orgánulos , Animales , Citoplasma , Ratones , Mitocondrias , Oocitos/metabolismo , Xenopus laevis
6.
J Cell Biol ; 219(9)2020 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-32573693

RESUMEN

In vitro experiments have shown that GRASP65 (GORASP1) and GRASP55 (GORASP2) proteins function in stacking Golgi cisternae. However, in vivo depletion of GORASPs in metazoans has given equivocal results. We have generated a mouse lacking both GORASPs and find that Golgi cisternae remained stacked. However, the stacks are disconnected laterally from each other, and the cisternal cross-sectional diameters are significantly reduced compared with their normal counterparts. These data support earlier findings on the role of GORASPs in linking stacks, and we suggest that unlinking of stacks likely affects dynamic control of COPI budding and vesicle fusion at the rims. The net result is that cisternal cores remain stacked, but cisternal diameter is reduced by rim consumption.


Asunto(s)
Aparato de Golgi/metabolismo , Proteínas de la Matriz de Golgi/metabolismo , Animales , Vesículas Cubiertas por Proteínas de Revestimiento/metabolismo , Femenino , Membranas Intracelulares/metabolismo , Fusión de Membrana/fisiología , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL
7.
Sci Eng Ethics ; 26(3): 1709-1741, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32239384

RESUMEN

When one wants to use citizen input to inform policy, what should the standards of informedness on the part of the citizens be? While there are moral reasons to allow every citizen to participate and have a voice on every issue, regardless of education and involvement, designers of participatory assessments have to make decisions about how to structure deliberations as well as how much background information and deliberation time to provide to participants. After assessing different frameworks for the relationship between science and society, we use Philip Kitcher's framework of Well-Ordered Science to propose an epistemic standard on how citizen deliberations should be structured. We explore what potential standards follow from this epistemic framework focusing on significance versus scientific and engineering expertise. We argue that citizens should be tutored on the historical context of why scientific questions became significant and deemed scientifically and socially valuable, and if citizens report that they are capable of weighing in on an issue then they should be able to do so. We explore what this standard can mean by looking at actual citizen deliberations tied to the 2014 NASA ECAST Asteroid Initiative Citizen forums. We code different vignettes of citizens debating alternative approaches for Mars exploration based upon what level of information seemed to be sufficient for them to feel comfortable in making a policy position. The analysis provides recommendations on how to design and assess future citizen assessments grounded in properly conveying the historical value context surrounding a scientific issue and trusting citizens to seek out sufficient information to deliberate.


Asunto(s)
Tecnología , Humanos
8.
J Cell Biol ; 216(9): 2691-2700, 2017 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-28794127

RESUMEN

The nutrient starvation-specific unconventional secretion of Acb1 in Saccharomyces cerevisiae requires ESCRT-I, -II, and -III and Grh1. In this study, we report that another signal sequence lacking cytoplasmic protein, superoxide dismutase 1 (SOD1), and its mutant form linked to amyotrophic lateral sclerosis (ALS), is also secreted by yeast upon nutrient starvation in a Grh1- and ESCRT-I-, -II-, and -III-dependent process. Our analyses reveal that a conserved diacidic motif (Asp-Glu) in these proteins is necessary for their export. Importantly, secretion of wild-type human SOD1 and the ALS-linked mutant in human cells also require the diacidic residues. Altogether, these findings reveal information encoded within the cytoplasmic proteins required for their unconventional secretion and provide a means to unravel the significance of the cytoplasmic versus the secreted form of mutant SOD1 in the pathology of ALS. We also propose how cells, based on a signal-induced change in cytoplasmic physiology, select a small pool of a subset of cytoplasmic proteins for unconventional secretion.

9.
Catheter Cardiovasc Interv ; 88(3): E67-73, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26526783

RESUMEN

OBJECTIVES: In this study we sought to evaluate coverage and apposition of Synergy™ stent at 3 and 6 months after implantation. BACKGROUND: The Pt-Cr everolimus-eluting stent with abluminal bioabsorbable polymer (Synergy™) is a new generation drug-eluting stent with features potentially favoring an early healing process which could make safe a shorter period of dual antiplatelet-therapy treatment. METHODS: Prospective, two-centers study enrolling patients with similar lesions treated with Synergy™ stents undergoing examination with OCT at 3 and 6 months in the respective centers. Blinded analysis was done at a core lab. Co-primary endpoints were proportion of struts with coverage and with apposition at 3 and 6 months. RESULTS: Finally, 22 patients (30 stents) in the 3 months group and 20 patients (30 stents) in the 6 months group were included. There were no significant differences between groups regarding clinical, angiographic measurements, and procedural data. The rate of strut coverage was 94.5% at 3 months and 96.6% at 6 months (P < 0.001), the rates of apposition were 93.8% and 96.2%, respectively, (P < 0.001), the proportion of uncovered but apposed struts was 2.5% and 1.9% (P = 0.03) and the proportion of uncovered and malapposed struts was 3% and 1.8%, respectively (P < 0.001). The maximal area of malapposition related with uncovered struts was 0.43 ± 0.4 mm(2) at 3 months and 0.14 ± 0.2 mm(2) at 6 months (P = 0.001). CONCLUSIONS: The everolimus-eluting stent with absorbable polymer, Synergy™, is associated to a high degree of intimal coverage and apposition at 3 months after implantation with additional increase at 6 months. © 2015 Wiley Periodicals, Inc.


Asunto(s)
Implantes Absorbibles , Fármacos Cardiovasculares/administración & dosificación , Enfermedad de la Arteria Coronaria/terapia , Vasos Coronarios/efectos de los fármacos , Stents Liberadores de Fármacos , Everolimus/administración & dosificación , Intervención Coronaria Percutánea/instrumentación , Polímeros/química , Tomografía de Coherencia Óptica , Cicatrización de Heridas/efectos de los fármacos , Anciano , Fármacos Cardiovasculares/efectos adversos , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Everolimus/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neointima , Intervención Coronaria Percutánea/efectos adversos , Inhibidores de Agregación Plaquetaria/administración & dosificación , Valor Predictivo de las Pruebas , Estudios Prospectivos , Diseño de Prótesis , España , Factores de Tiempo , Resultado del Tratamiento
10.
J Cell Biol ; 207(6): 695-703, 2014 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-25512390

RESUMEN

Upon starvation, Grh1, a peripheral membrane protein located at endoplasmic reticulum (ER) exit sites and early Golgi in Saccharomyces cerevisiae under growth conditions, relocates to a compartment called compartment for unconventional protein secretion (CUPS). Here we report that CUPS lack Golgi enzymes, but contain the coat protein complex II (COPII) vesicle tethering protein Uso1 and the Golgi t-SNARE Sed5. Interestingly, CUPS biogenesis is independent of COPII- and COPI-mediated membrane transport. Pik1- and Sec7-mediated membrane export from the late Golgi is required for complete assembly of CUPS, and Vps34 is needed for their maintenance. CUPS formation is triggered by glucose, but not nitrogen starvation. Moreover, upon return to growth conditions, CUPS are absorbed into the ER, and not the vacuole. Altogether our findings indicate that CUPS are not specialized autophagosomes as suggested previously. We suggest that starvation triggers relocation of secretory and endosomal membranes, but not their enzymes, to generate CUPS to sort and secrete proteins that do not enter, or are not processed by enzymes of the ER-Golgi pathway of secretion.


Asunto(s)
Vesículas Cubiertas por Proteínas de Revestimiento/metabolismo , Saccharomyces cerevisiae/metabolismo , Vesículas Secretoras/metabolismo , 1-Fosfatidilinositol 4-Quinasa/metabolismo , Fosfatidilinositol 3-Quinasas Clase III/metabolismo , Medios de Cultivo , Retículo Endoplásmico/metabolismo , Glucosa/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Transporte de Proteínas , Proteínas Qa-SNARE/metabolismo , Saccharomyces cerevisiae/citología , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo
11.
EMBO J ; 31(24): 4535-46, 2012 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-23178595

RESUMEN

Sphingomyelin and cholesterol can assemble into domains and segregate from other lipids in the membranes. These domains are reported to function as platforms for protein transport and signalling. Do similar domains exist in the Golgi membranes and are they required for protein secretion? We tested this hypothesis by using D-ceramide-C6 to manipulate lipid homeostasis of the Golgi membranes. Lipidomics of the Golgi membranes isolated from D-ceramide-C6-treated HeLa cells revealed an increase in the levels of C6-sphingomyelin, C6-glucosylceramide, and diacylglycerol. D-ceramide-C6 treatment in HeLa cells inhibited transport carrier formation at the Golgi membranes without affecting the fusion of incoming carriers. The defect in protein secretion as a result of D-ceramide-C6 treatment was alleviated by knockdown of the sphingomyelin synthases 1 and 2. C6-sphingomyelin prevented liquid-ordered domain formation in giant unilamellar vesicles and reduced the lipid order in the Golgi membranes of HeLa cells. These findings highlight the importance of a regulated production and organization of sphingomyelin in the biogenesis of transport carriers at the Golgi membranes.


Asunto(s)
Aparato de Golgi/química , Aparato de Golgi/fisiología , Lípidos de la Membrana/análisis , Microdominios de Membrana/fisiología , Proteínas/metabolismo , Esfingomielinas/metabolismo , Vesículas Transportadoras/fisiología , Ceramidas/farmacología , Diglicéridos , Técnicas de Silenciamiento del Gen , Células HeLa , Humanos , Lípidos de la Membrana/aislamiento & purificación , Microdominios de Membrana/química , Microscopía Electrónica , Microscopía Fluorescente , Oligonucleótidos/genética , Interferencia de ARN , Espectrometría de Fluorescencia , Transferasas (Grupos de Otros Fosfatos Sustitutos)/genética , Transferasas (Grupos de Otros Fosfatos Sustitutos)/metabolismo , Vesículas Transportadoras/química
12.
J Cell Biol ; 195(6): 979-92, 2011 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-22144692

RESUMEN

The endoplasmic reticulum (ER)-Golgi-independent, unconventional secretion of Acb1 requires many different proteins. They include proteins necessary for the formation of autophagosomes, proteins necessary for the fusion of membranes with the endosomes, proteins of the multivesicular body pathway, and the cell surface target membrane SNARE Sso1, thereby raising the question of what achieves the connection between these diverse proteins and Acb1 secretion. In the present study, we now report that, upon starvation in Saccharomyces cerevisiae, Grh1 is collected into unique membrane structures near Sec13-containing ER exit sites. Phosphatidylinositol 3 phosphate, the ESCRT (endosomal sorting complex required for transport) protein Vps23, and the autophagy-related proteins Atg8 and Atg9 are recruited to these Grh1-containing membranes, which lack components of the Golgi apparatus and the endosomes, and which we call a novel compartment for unconventional protein secretion (CUPS). We describe the cellular proteins required for the biogenesis of CUPS, which we believe is the sorting station for Acb1's release from the cells.


Asunto(s)
Autofagia/fisiología , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Familia de las Proteínas 8 Relacionadas con la Autofagia , Proteínas Relacionadas con la Autofagia , Proteínas Portadoras/metabolismo , Retículo Endoplásmico/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Proteínas de Complejo Poro Nuclear/metabolismo , Fagosomas , Proteínas SNARE/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo
13.
J Cell Biol ; 188(4): 527-36, 2010 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-20156967

RESUMEN

Starving Dictyostelium discoideum cells secrete AcbA, an acyl coenzyme A-binding protein (ACBP) that lacks a conventional signal sequence for entering the endoplasmic reticulum (ER). Secretion of AcbA in D. discoideum requires the Golgi-associated protein GRASP. In this study, we report that starvation-induced secretion of Acb1, the Saccharomyces cerevisiae ACBP orthologue, also requires GRASP (Grh1). This highlights the conserved function of GRASP in unconventional secretion. Although genes required for ER to Golgi or Golgi to cell surface transport are not required for Acb1 secretion in yeast, this process involves autophagy genes and the plasma membrane t-SNARE, Sso1. Inhibiting transport to vacuoles does not affect Acb1 secretion. In sum, our experiments reveal a unique secretory pathway where autophagosomes containing Acb1 evade fusion with the vacuole to prevent cargo degradation. We propose that these autophagosome intermediates fuse with recycling endosomes instead to form multivesicular body carriers that then fuse with the plasma membrane to release cargo.


Asunto(s)
Autofagia , Proteínas Portadoras/metabolismo , Fagosomas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/metabolismo , Secuencia de Aminoácidos , Autofagia/genética , Proteínas Portadoras/química , Membrana Celular/metabolismo , Genes Fúngicos/genética , Aparato de Golgi/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Fusión de Membrana , Modelos Biológicos , Datos de Secuencia Molecular , Cuerpos Multivesiculares/metabolismo , Péptidos/metabolismo , Proteínas Qa-SNARE/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Vías Secretoras , Vacuolas/metabolismo
14.
J Cell Biol ; 187(7): 1055-69, 2009 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-20026655

RESUMEN

Knockdown of the actin-severing protein actin-depolymerizing factor (ADF)/cofilin inhibited export of an exogenously expressed soluble secretory protein from Golgi membranes in Drosophila melanogaster and mammalian tissue culture cells. A stable isotope labeling by amino acids in cell culture mass spectrometry-based protein profiling revealed that a large number of endogenous secretory proteins in mammalian cells were not secreted upon ADF/cofilin knockdown. Although many secretory proteins were retained, a Golgi-resident protein and a lysosomal hydrolase were aberrantly secreted upon ADF/cofilin knockdown. Overall, our findings indicate that inactivation of ADF/cofilin perturbed the sorting of a subset of both soluble and integral membrane proteins at the trans-Golgi network (TGN). We suggest that ADF/cofilin-dependent actin trimming generates a sorting domain at the TGN, which filters secretory cargo for export, and that uncontrolled growth of this domain causes missorting of proteins. This type of actin-dependent compartmentalization and filtering of secretory cargo at the TGN by ADF/cofilin could explain sorting of proteins that are destined to the cell surface.


Asunto(s)
Factores Despolimerizantes de la Actina/fisiología , Actinas/metabolismo , Drosophila melanogaster/metabolismo , Red trans-Golgi/metabolismo , Factores Despolimerizantes de la Actina/genética , Animales , Células Cultivadas , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiología , Células HeLa , Humanos , Membranas Intracelulares/metabolismo , Espectrometría de Masas , Proteínas de la Membrana/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas de Microfilamentos/fisiología , Fosforilación , Transporte de Proteínas , Inhibidor Tisular de Metaloproteinasa-1/metabolismo
15.
Mech Ageing Dev ; 130(4): 227-33, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19150623

RESUMEN

The kidney synthesizes L-carnitine and reabsorbs it via the Na(+)/L-carnitine cotransporter OCTN2. This study investigates the ontogeny of OCTN2, gamma-trimethylaminobutyraldehyde dehydrogenase (TMABA-DH) and gamma-butyrobetaine hydroxylase (BBH) in rat kidneys. Foetuses, newborn, suckling, weaning and adult rats were used. The apical membranes of foetal and newborn rat kidneys express OCTN2 transport activity, which is up-regulated by age. Maturation significantly increased the V(max) of this transport system without changing the apparent K(t), which excludes a maturation-related expression of different transporter isoforms. Northern analysis showed a 3.7kb transcript for OCTN2 in all the ages tested. Northern and RT-PCR assays revealed that maturation increased renal expression of OCTN2 mRNA. Foetuses express TMABA-DH mRNA and this expression increased during postnatal life. BBH mRNA, however, was detected during the suckling period onwards and its abundance was not changed significantly by maturation. This study reports for the first time that, in rat kidneys: (i) an apical OCTN2 transporter is active in rat foetuses, (ii) ontogeny up-regulates OCTN2 activity by increasing the density and/or turnover of the transporters, (iii) the maturation-related changes in OCTN2 are in part mediated by transcriptional mechanism(s) and (iv) the expression of both, TMABA-DH and BBH mRNA is ontogenically regulated. Some of these results were published as an abstract (García-Delgado et al., 2003).


Asunto(s)
Aldehído Oxidorreductasas/metabolismo , Regulación de la Expresión Génica/genética , Riñón/enzimología , Proteínas de Transporte de Catión Orgánico/metabolismo , gamma-Butirobetaína Dioxigenasa/metabolismo , Envejecimiento/fisiología , Aldehído Oxidorreductasas/genética , Animales , Carnitina/metabolismo , Cinética , Proteínas de Transporte de Catión Orgánico/genética , ARN Mensajero/genética , Ratas , Ratas Wistar , Miembro 5 de la Familia 22 de Transportadores de Solutos , gamma-Butirobetaína Dioxigenasa/genética
16.
Rev Esp Cardiol ; 57(3): 201-8, 2004 Mar.
Artículo en Español | MEDLINE | ID: mdl-15056423

RESUMEN

INTRODUCTION AND OBJECTIVES: Experimental and clinical studies suggest that necrotic myocardium may have the capacity to regenerate. We have started a clinical study to demonstrate that the intracoronary implantation of stem cells is feasible and safe. The results in our first 5 patients are presented here. PATIENTS AND METHOD: We included patients with anterior acute myocardial infarction and isolated stenosis of the left anterior descending artery that was successfully repaired by primary or facilitated angioplasty. Patients received an intracoronary infusion of bone marrow-derived cells 10-15 days after the infarction. The follow-up protocol included low-dose dobutamine echocardiography, magnetic resonance studies and ECG Holter monitoring. RESULTS: The procedure was carried out with no complications. No patient had a cardiac event during the first 6 months. One patient had a transient ischemic attack without sequelae. No arrhythmias were found. Left ventricular end-diastolic volume remained the same at 6 months (159+/-25 ml, 157+/-16 ml), left ventricular end-systolic volume decreased (77+/-22 ml, 65+/-16 ml), and the ejection fraction increased (53+/-7%, 58+/-8%) although no statistically significant differences were found. In the 3 patients in whom dobutamine echocardiography ruled out viability, we found a significant reduction in both volumes. CONCLUSIONS: Intracoronary bone marrow-derived cell transplantation after an acute myocardial infarction seems to be safe and feasible, and might lead to favorable remodeling.


Asunto(s)
Infarto del Miocardio/terapia , Trasplante de Células Madre/métodos , Disfunción Ventricular Izquierda/terapia , Anciano , Vasos Coronarios/fisiopatología , Estudios de Factibilidad , Humanos , Masculino , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Radiografía , Resultado del Tratamiento , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular Izquierda/fisiología , Remodelación Ventricular/fisiología
17.
FEBS Lett ; 563(1-3): 59-65, 2004 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-15063723

RESUMEN

Sphingolipids are basic constituents of cellular membranes and are essential for numerous functions such as intracellular signalling. They are transported along the exocytic and endocytic pathways in eukaryotic cells. After endocytosis, fluorescent-labelled sphingolipids are sorted to distinct intracellular organelles prior to recycling (via early/recycling endosomes) or degradation (late endosomes/lysosomes). Here we examine, in primary cultures of rat astrocytes, the internalisation routes followed by C(6)-NBD-glucosylceramide (NBD-GlcCer) and C(6)-NBD-sphingomyelin (NBD-SM) and the effects of ethanol on their endocytic trafficking. Endocytosed plasma membrane NBD-GlcCer and NBD-SM are diverted to the Golgi apparatus and lysosomes, respectively. These different internalisation pathways are maintained regardless of the differentiation stage of astrocytes. Chronic ethanol exposure did not alter this endocytic sorting, but delayed the internalisation of both NBD-sphingolipids. Moreover, ethanol also stimulated the in situ metabolism of NBD-ceramide to NBD-GlcCer and NBD-SM. We conclude that in rat astrocytes internalised plasma membrane NBD-sphingolipids are sorted to different subcellular compartments. The exposure to chronic ethanol perturbed the lipid endocytic process and stimulated the de novo synthesis of NBD-sphingolipids, shifting the balance of sphingolipid metabolism in favour of the sphingomyelin pathway.


Asunto(s)
Astrocitos/metabolismo , Membrana Celular/metabolismo , Etanol/farmacología , Membranas Intracelulares/metabolismo , Esfingolípidos/metabolismo , Animales , Anticuerpos Monoclonales/metabolismo , Astrocitos/citología , Transporte Biológico/efectos de los fármacos , Brefeldino A/farmacología , Compartimento Celular/efectos de los fármacos , Diferenciación Celular , Membrana Celular/química , Células Cultivadas , Endocitosis/efectos de los fármacos , Feto , Colorantes Fluorescentes/química , Colorantes Fluorescentes/metabolismo , Aparato de Golgi/metabolismo , Lisosomas/metabolismo , Lípidos de la Membrana/química , Lípidos de la Membrana/metabolismo , Nocodazol/farmacología , Inhibidores de la Síntesis de la Proteína/farmacología , Ratas , Esfingolípidos/química , Factores de Tiempo
18.
Glycobiology ; 14(6): 495-500, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15033941

RESUMEN

D-mannose transport and metabolism has been studied in enterocytes isolated from chicken small intestine. In the presence of Na(+), the mannose taken up by the cells either remains free, is phosphorylated, is catabolized to H(2)O, or becomes part of membrane components. The mannose remaining free in the cytosol is released when the cells are transferred to an ice bath. The Na(+)-dependent D-mannose transport is electrogenic and inhibited by ouabain and dinitrophenol; its substrate specificity differs from SGLT-1 transporter. The Glut2 transporter inhibitors phloretin and cytochalasin B added following 30-min mannose uptake reduced the previously accumulated D-mannose, whereas these two agents increased the cell to external medium 3-O-methyl-glucose (3-OMG) concentration ratio. D-mannose efflux rate from preloaded D-[2-(3)H]-mannose enterocytes is Na(+)-independent. Phloretin did not affect D-mannose efflux rate, whereas it inhibited that of 3-OMG. Neither mannose uptake nor efflux rate were affected by fructose. It is concluded that part of the mannose taken up by the enterocytes is rapidly metabolized and that enterocytes have two D- mannose transport systems: one is concentrative and Na(+)-dependent and the other is Na(+)-independent and passive.


Asunto(s)
Enterocitos/metabolismo , Manosa/metabolismo , Animales , Transporte Biológico , Pollos , Citocalasina B/farmacología , Enterocitos/enzimología , Técnicas In Vitro , Iones , Cinética , Manosa-6-Fosfato Isomerasa , Floretina/farmacología , Fosforilación
19.
Rev Esp Cardiol ; 56(11): 1105-18, 2003 Nov.
Artículo en Español | MEDLINE | ID: mdl-14622542

RESUMEN

The results of the Registry of the Working Group on Cardiac Catheterization and Interventional Cardiology of the Spanish Society of Cardiology for 2002 are presented. Data were obtained from 101 centers representing all cardiac catheterization laboratories in Spain; 95 centers performed mainly adult catheterization and 6 carried out only pediatric procedures. In 2002, 97,609 diagnostic catheterization procedures were performed, including 83,667 coronary angiograms, representing a total increase of 5.1% in comparison to 2001. The population-adjusted rate was 2,053 coronary angiograms per 106 inhabitants. Coronary interventions increased by 11% in comparison to 2001, with a total of 34,723 procedures and a rate of coronary interventions of 850 per 106 inhabitants. Coronary stents were the devices used most frequently, with 47,249 implanted in 2002, for a total increase of 20% in comparison to 2001. Stenting accounted for 91.7% of all procedures. Direct stenting was done in 13 768 procedures (43.2%). IIb-IIIa glycoprotein inhibitors were used in 9966 procedures (28.7%). Multivessel percutaneous coronary interventions were performed in 9,830 patients (28%), and ad hoc interventions were done in the course of diagnostic coronary angiography in 26,341 patients (76%).A total of 4,766 percutaneous coronary interventions were done in patients with acute myocardial infarction, representing an increase of 23.9% in comparison to 2001, and accounting for 13.7% of all interventional procedures. Of the noncoronary interventions recorded, we note the decrease in percutaneous mitral valvuloplasties (21.2%) and atrial septal defect closures (11.1%), and the slight increase in pediatric interventions (3.7%). In conclusion, we emphasize the high rate of reporting by laboratories, which allows the Registry to compile data that are highly representative of the activity at cardiac catheterization laboratories in Spain


Asunto(s)
Cateterismo Cardíaco/estadística & datos numéricos , Angiografía Coronaria/estadística & datos numéricos , Cardiopatías/diagnóstico , Cardiopatías/terapia , Sistema de Registros/estadística & datos numéricos , Adulto , Angioplastia Coronaria con Balón/estadística & datos numéricos , Servicio de Cardiología en Hospital/estadística & datos numéricos , Niño , Cardiopatías/fisiopatología , Hemodinámica/fisiología , Humanos , Radiología Intervencionista/estadística & datos numéricos , España , Encuestas y Cuestionarios
20.
J Neurochem ; 87(1): 220-9, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12969268

RESUMEN

Ethanol induces severe alterations in membrane trafficking in hepatocytes and astrocytes, the molecular basis of which is unclear. One of the main candidates is the cytoskeleton and the molecular components that regulate its organization and dynamics. Here, we examine the effect of chronic exposure to ethanol on the organization and dynamics of actin and microtubule cytoskeletons and glucose uptake in rat astrocytes. Ethanol-treated cells cultured in either the presence or absence of fetal calf serum showed a significant increase in 2-deoxyglucose uptake. Ethanol also caused alterations in actin organization, consisting of the dissolution of stress fibres and the appearance of circular filaments beneath the plasma membrane. When lysophosphatidic acid (LPA), which is a normal constituent of serum and a potent intercellular lipid mediator with growth factor and actin rearrangement activities, was added to ethanol-treated astrocytes cultured without fetal calf serum, it induced the re-appearance of actin stress fibres and the normalization of 2-deoxyglucose uptake. Furthermore, ethanol also perturbed the microtubule dynamics, which delayed the recovery of the normal microtubule organization following removal of the microtubule-disrupting agent nocodazole. Again, pre-treatment with LPA prevented this alteration. Ethanol-treated rodent fibroblast NIH3T3 cells that constitutively express an activated Rho mutant protein (GTP-bound form) were insensitive to ethanol, as they showed no alteration either in actin stress-fibre organization or in 2-deoxyglucose uptake. We discuss the putative signalling targets by which ethanol could alter the cytoskeleton and hexose uptake and the cytoprotective effect of LPA against ethanol-induced damages. The latter opens the possibility that LPA or a similar non-hydrolysable lipid derivative could be used as a cytoprotective agent against the noxious effects of ethanol.


Asunto(s)
Astrocitos/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Etanol/toxicidad , Glucosa/farmacocinética , Lisofosfolípidos/farmacología , Células 3T3 , Citoesqueleto de Actina/metabolismo , Animales , Astrocitos/citología , Astrocitos/metabolismo , Transporte Biológico/efectos de los fármacos , Células Cultivadas , Medio de Cultivo Libre de Suero/farmacología , Desoxiglucosa/farmacocinética , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Ratones , Microtúbulos/metabolismo , Ratas , Proteína de Unión al GTP rhoA/biosíntesis , Proteína de Unión al GTP rhoA/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA