Efectos del TGF-Beta en células monocíticas: regulación funcional de las glicoproteínas Pecam-1 (CD31) y endoglina (CD105)

El TGF-beta es una citoquina multifuncional con capacidad de modular muchas funciones en diferentes tipos celulares. En este trabajo se han estudiado algunas de las respuestas que el factor induce en el linaje celular monocítico. Tres puntos constituyen el núcleo de dicho estudio: 1. La regulación funcional de la proteína de adhesión pecam-1 presente en la membrana de las células monocíticas. 2. La regulación de la expresión y del estado de fosforilación de endoglina, un receptor del TGF-beta de función desconocida y también presente en las células del linaje monocítico-macrofágico. 3. Estudio de la implicación de endoglina en las respuestas celulares inducidas por el factor en dicho linaje celular. nuestros resultados indican que ambas glicoproteínas son reguladas funcionalmente por el factor y que endoglina es un modulador negativo de algunas de las respuestas que dicho factor induce

Involvement of ERK1/2, p38 and PI3K in megakaryocytic differentiation of K562 cells

22 p.-7 fig.Megakaryocytic differentiation of myelogenous leukemia cell lines induced by a number of chemical compounds mimics, in part, the physiological process that takes place in the bone marrow in response to a variety of stimuli. We have investigated the involvement of mitogen-activated protein kinases (MAPKs) [extracellular signal-regulated protein kinase (ERK1/2) and p38] and phosphoinositide 3-kinase (PI3K) signaling pathways in the differentiated phenotypes of K562 cells promoted by phorbol 12-myristate 13-acetate, staurosporine (STA), and the p38 MAPK inhibitor SB202190. In our experimental conditions, only STA-treated cells showed the phenotype of mature megakaryocytes (MKs) including GPIbα expression, DNA endoreduplication, and formation of platelet-like structures. We provide evidence supporting that basal activity, but not sustained activation, of ERK1/2 is required for expression of MK surface markers. Moreover, ERK1/2 signaling is not involved in cell endomitosis. The PI3K pathway exerts dual regulatory effects on K562 cell differentiation: it is intimately connected with ERK1/2 cascade to stimulate expression of surface markers and it is also necessary, but not sufficient, for polyploidization. Finally, apoptosis and megakaryocytic differentiation exhibit different sensitivity to p38 down-regulation: it is required for expression of early specific markers but is not involved in cell apoptosis. The present work with K562 cells provides new insights into the molecular mechanisms regulating MK differentiation. The results indicate that a precise orchestration of signals, including ERK1/2 and p38 MAPKs as well as PI3K pathway, is necessary for acquisition of features of mature MKs.This work was supported by grants from the Dirección General de Investigación del Ministerio de Educación y Ciencia (BMC2003-01409 and BFU2006-00914). A. Jayo was recipient of a fellowship from the Ministerio de Educación y Ciencia. I. Conde holds a research contract from the Consejo Superior de Investigaciones CientíficasPeer Reviewe

Geopolitik und sicherheitspolitisches Potenzial neuer regionaler Führungsmächte

Endolysins comprise a novel class of selective antibacterials refractory to develop resistances. The Cpl-7 endolysin, encoded by the Streptococcus pneumoniae bacteriophage Cp-7, consists of a catalytic module (CM) with muramidase activity and a cell wall-binding module (CWBM) made of three fully conserved CW_7 repeats essential for activity. Firstly identified in the Cpl-7 endolysin, CW_7 motifs are also present in a great variety of cell wall hydrolases encoded, among others, by human and live-stock pathogens. However, the nature of CW_7 receptors on the bacterial envelope remains unknown. In the present study, the structural stability of Cpl-7 and the target recognized by CW_7 repeats, relevant for exploitation of Cpl-7 as antimicrobial, have been analyzed, and transitions from the CM and the CWBM assigned, using circular dichroism and differential scanning calorimetry. Cpl-7 stability is maximum around 6.0-6.5, near the optimal pH for activity. Above pH 8.0 the CM becomes extremely unstable, probably due to deprotonation of the N-terminal amino-group, whereas the CWBM is rather insensitive to pH variation and its structural stabilization by GlcNAc-MurNAc-l-Ala-d-isoGln points to the cell wall muropeptide as the cell wall target recognized by the CW_7 repeats. Denaturation data also revealed that Cpl-7 is organized into two essentially independent folding units, which will facilitate the recombination of the CM and the CWBM with other catalytic domains and/or cell wall-binding motifs to yield new tailored chimeric lysins with higher bactericidal activities or new pathogen specificities

New insights into the expression and role of platelet FXIII-A

25 p.-6 fig.Background: The A subunit of factor XIII (FXIII-A) functions as an intracellular transglutaminase (TG) in the megakaryocyte/platelet lineage, where it probably participates in the cytoskeletal remodeling associated with cell activation. However, so far, the precise role of cellular FXIII (cFXIII) and the functional consequences of its absence in FXIII-A-deficient patients are unknown. Objectives and methods: In this study, we used platelets from four patients with congenital deficiency of FXIII-A to study the role of cFXIII in platelet functions. Results: We found that FXIII-A represents the only detectable source of TG activity in platelets and that the binding of fibrinogen in response to thrombin receptor agonist peptide (TRAP) stimulation was significantly reduced in platelets from the patients. In agreement with this, in control platelets, monodansyl-cadaverine (MDC), a competitive amino-donor for TGs, inhibited fibrinogen binding induced by TRAP in a dose-dependent manner. Moreover, upon adhesion to fibrinogen, normal platelets incubated with MDC as well as FXIII-A-deficient platelets showed a distinct extension pattern with reduced lamellipodia and increased filopodia formation, suggesting a delay in spreading. Conclusions: These findings provide evidence for the direct involvement of cFXIII-dependent TG activity in the regulation of platelet functionsThis work was supported by grants from the Dirección General de Investigación del Ministerio de Educación y Ciencia (BFU2006-00914) and Fundación Rodríguez Pascual. A. Jayo was recipient of a fellowship from the Ministerio de Educación y Ciencia. I. Conde holds a research contract from the Consejo Superior de Investigaciones Científica

Substrate recognition and catalysis by LytB, a pneumococcal peptidoglycan hydrolase involved in virulence

17 p.-7 fig.-2 tab. Rico-Lastres, Palma et al.Streptococcus pneumoniae is a major cause of life-threatening diseases worldwide. Here we provide an in-depth functional characterization of LytB, the peptidoglycan hydrolase responsible for physical separation of daughter cells. Identified herein as an N-acetylglucosaminidase, LytB is involved also in colonization and invasion of the nasopharynx, biofilm formation and evasion of host immunity as previously demonstrated. We have shown that LytB cleaves the GlcNAc-β-(1,4)-MurNAc glycosidic bond of peptidoglycan building units. The hydrolysis occurs at sites with fully acetylated GlcNAc moieties, with preference for uncross-linked muropeptides. The necessity of GlcN acetylation and the presence of a single acidic moiety (Glu585) essential for catalysis strongly suggest a substrate-assisted mechanism with anchimeric assistance of the acetamido group of GlcNAc moieties. Additionally, modelling of the catalytic region bound to a hexasaccharide tripentapeptide provided insights into substrate-binding subsites and peptidoglycan recognition. Besides, cell-wall digestion products and solubilisation rates might indicate a tight control of LytB activity to prevent unrestrained breakdown of the cell wall. Choline-independent localization at the poles of the cell, mediated by the choline-binding domain, peptidoglycan modification, and choline-mediated (lipo) teichoic-acid attachment contribute to the high selectivity of LytB. Moreover, so far unknown chitin hydrolase and glycosyltransferase activities were detected using GlcNAc oligomers as substrate.Research was funded by grants from the Ministerio de Ciencia e Innovación (MICINN) and the Ministerio de Economía y Competitividad (MINECO) to P. García (SAF2009-10824 and SAF2012-39444-C02-01) and M. Menéndez (BFU2009-10052 and BFU2012-36825), the Consejería de Educación de la Comunidad de Madrid (S2010/BMD/2457) to M. Menéndez. The work in the United Kingdom and the US was supported by grants from the BBSRC (BB/G015902/1) to W. Vollmer and from the National Institutes of Health (GM61629) to S. Mobashery. Additional funding was provided by the CIBER de Enfermedades Respiratorias (CIBERES), an initiative of the Instituto de Salud Carlos III (ISCIII). Palma Rico-Lastres and Roberto Díez-Martínez were the recipients of fellowships from the MICINN (FPI program).Peer reviewe

IDT-3D: Identification and tracking in controlled environments using a 3D unified user interface

Identification and tracking of objects in specific environments such as harbors or security areas is a matter of great importance nowadays. With this purpose, numerous systems based on different technologies have been developed, resulting in a great amount of gathered data displayed through a variety of interfaces. Such amount of information has to be evaluated by human operators in order to take the correct decisions, sometimes under highly critical situations demanding both speed and accuracy. In order to face this problem we describe IDT-3D, a platform for identification and tracking of vessels in a harbour environment able to represent fused information in real time using a Virtual Reality application. The effectiveness of using IDT-3D as an integrated surveillance system is currently under evaluation. Preliminary results point to a significant decrease in the times of reaction and decision making of operators facing up a critical situation. Although the current application focus of IDT-3D is quite specific, the results of this research could be extended to the identification and tracking of targets in other controlled environments of interest as coastlines, borders or even urban areas

Virtual Domotic Systems: a 3D Interaction Technique to Control Virtual Building Devices Using Residential Gateways

Residential gateways are systems based on different control technologies that provide a unified way of communication for various devices and appliances present in homes and buildings (sensors, control systems, electronic devices, etc.). The massive introduction of residential gateways in the market is often hindered by the lack of intuitive configuration and visualization interfaces. Moreover, users frequently obtain very limited feedback about the status of the building after the actions carried out by the residential gateway, what reduces the confidence in such systems. This paper presents a Virtual Domotic System (VDS), an innovative solution to provide a Virtual Reality interface to manage residential gateways. VDS comprises three main blocks. The first of them is the residential gateway and the associated control devices of the building. The second element is an advanced 3D Virtual Environment that reliably represents the building, the state of control devices and the environmental characteristics (such as lighting or temperature). Finally, the system includes the software that enables the communication and synchronization between the virtual environment and the control technologies and appliances of the building. The VDS introduces a new 3D interaction technique, where the inputs that modify and configure the 3D virtual environment come directly from the sensors and actuators installed in the buildin

La importancia de los intereses académicos en la política científica y tecnológica catalana

Publicado en: 'Papers: Revista de Sociología', 70: 11-40, 2003Este artículo describe la emergencia y orientación de las políticas de I+D e innovación en Cataluña. Se analizan cuáles son los factores más influyentes en la orientación de estas políticas y, en definitiva, en las opciones políticas que se toman. La política de ciencia y tecnología desarrollada por el gobierno regional catalán desde principios de los años ochenta ha sido una política en la que, a pesar de las preferencias manifestadas en el discurso político, ha predominado un modelo de política académico sobre el de orientación empresarial. Asimismo, en términos organizativos e institucionales, en la Administración autonómica, la política científica ha estado separada y diferenciada de la política tecnológica a pesar del diseño inicial de instituciones interdepartamentales. La principal razón de que la política de I+D catalana no siguiera un modelo más industrial, ligado al mundo empresarial, fue la presión que ejercieron las universidades catalanas para que, tanto el diseño institucional como el contenido de la política se adaptara a sus necesidades. La trayectoria académica previa de los gestores también contribuyó a la reorientación de las preferencias políticas. A pesar de la importancia de las empresas catalanas en la I+D, éstas no se movilizaron ni presionaron a los gobiernos suficientemente. Analíticamente, este caso ilustra cómo la sola creación política de instituciones no garantiza la realización de las preferencias políticas. También pone de manifiesto cómo el horizonte temporal de la toma de decisiones gubernamental tiene un efecto en las expectativas de los actores, que desarrollan procesos de aprendizaje a partir de las experiencias en arenas políticas similares a otros niveles. Por último, destaca la importancia del poder en las instituciones de gestión en este tipo de política distributiva.Peer reviewe

La importancia de los intereses académicos en la política científica y tecnológica catalana

Publicado en: 'Papers: Revista de Sociología', 70: 11-40, 2003Este artículo describe la emergencia y orientación de las políticas de I+D e innovación en Cataluña. Se analizan cuáles son los factores más influyentes en la orientación de estas políticas y, en definitiva, en las opciones políticas que se toman. La política de ciencia y tecnología desarrollada por el gobierno regional catalán desde principios de los años ochenta ha sido una política en la que, a pesar de las preferencias manifestadas en el discurso político, ha predominado un modelo de política académico sobre el de orientación empresarial. Asimismo, en términos organizativos e institucionales, en la Administración autonómica, la política científica ha estado separada y diferenciada de la política tecnológica a pesar del diseño inicial de instituciones interdepartamentales. La principal razón de que la política de I+D catalana no siguiera un modelo más industrial, ligado al mundo empresarial, fue la presión que ejercieron las universidades catalanas para que, tanto el diseño institucional como el contenido de la política se adaptara a sus necesidades. La trayectoria académica previa de los gestores también contribuyó a la reorientación de las preferencias políticas. A pesar de la importancia de las empresas catalanas en la I+D, éstas no se movilizaron ni presionaron a los gobiernos suficientemente. Analíticamente, este caso ilustra cómo la sola creación política de instituciones no garantiza la realización de las preferencias políticas. También pone de manifiesto cómo el horizonte temporal de la toma de decisiones gubernamental tiene un efecto en las expectativas de los actores, que desarrollan procesos de aprendizaje a partir de las experiencias en arenas políticas similares a otros niveles. Por último, destaca la importancia del poder en las instituciones de gestión en este tipo de política distributiva.Este trabajo se ha realizado gracias a la financiación del Programa Marco de I+D, del PRICIT de la Comunidad de Madrid y del III Plan Nacional de I+D de la CICYT (SEC 1999-0829-C02-01).Peer reviewe

Endoglin is expressed in the chicken vasculature and is involved in angiogenesis

AbstractEndoglin is a component of the transforming growth factor β (TGF-β) receptor complex, highly expressed by endothelial cells. Mutations in the endoglin gene are responsible for hereditary hemorrhagic telangiectasia type 1 (HHT1), an autosomal dominant vascular disorder caused by a haploinsufficiency mechanism. Vascular lesions (telangiectasia and arteriovenous malformations) in HHT1 are associated with loss of the capillary network, suggesting the involvement of endoglin in vascular repair processes. Using the chick chorioallantoic membrane (CAM) as an angiogenic model, we have analyzed the expression and function of chicken endoglin. A pan-specific polyclonal antibody (pAb) recognized chicken endoglin as demonstrated by immunostaining and Western blot analysis. In ovo treatment of chicken embryos with this pAb resulted in a significantly increased area of CAM. This effect was likely mediated by modulation of the ligand binding to endoglin as this pAb was able to inhibit TGF-β1 binding. These results support the involvement of endoglin in the angiogenic process