Short telomeres protect from diet-induced atherosclerosis in apolipoprotein E-null mice

16 páginas, 6 figuras.-- Artículo presentado al Wokshop on “Telomeres and telomearase: therapeutical targets for cancer and aging” celebrado en Madrid (España) del 17 al 19 de Nov. del 2003.By imposing a replicative defect in most somatic cells, gradual telomere attrition during aging is thought to progressively impair cellular function and viability and may contribute to age-related disease. Immune cells play important roles in all phases of atherosclerosis, a multifactorial disease that prevails within the elderly. Because shorter telomeres have been found in circulating blood leukocytes of human patients with advanced coronary atherosclerosis, it has been suggested that telomere shortening may predispose the organism to atheroma development. In this study, we assessed the impact of telomere attrition on atherogenesis induced by dietary cholesterol in apolipoprotein E (apoE)-deficient mice, a well-established model of experimental atherosclerosis that recapitulates important aspects of the human disease. Our study shows that late-generation mice doubly deficient in apoE and telomerase RNA experience telomere attrition and a substantial reduction of atherosclerosis compared with control mice with intact telomerase, in spite of sustained hypercholesterolemia in response to the atherogenic diet. Short telomeres impaired the proliferation of both lymphocytes and macrophages, an important step in atherosclerosis development. Therefore, telomere exhaustion resulting in replicative immunosenescence may serve as a mechanism for restricting atheroma progression.Peer reviewe

Short telomeres protect from diet-induced atherosclerosis in apolipoprotein E-null mice

16 páginas, 6 figuras.-- Artículo presentado al Wokshop on “Telomeres and telomearase: therapeutical targets for cancer and aging” celebrado en Madrid (España) del 17 al 19 de Nov. del 2003.By imposing a replicative defect in most somatic cells, gradual telomere attrition during aging is thought to progressively impair cellular function and viability and may contribute to age-related disease. Immune cells play important roles in all phases of atherosclerosis, a multifactorial disease that prevails within the elderly. Because shorter telomeres have been found in circulating blood leukocytes of human patients with advanced coronary atherosclerosis, it has been suggested that telomere shortening may predispose the organism to atheroma development. In this study, we assessed the impact of telomere attrition on atherogenesis induced by dietary cholesterol in apolipoprotein E (apoE)-deficient mice, a well-established model of experimental atherosclerosis that recapitulates important aspects of the human disease. Our study shows that late-generation mice doubly deficient in apoE and telomerase RNA experience telomere attrition and a substantial reduction of atherosclerosis compared with control mice with intact telomerase, in spite of sustained hypercholesterolemia in response to the atherogenic diet. Short telomeres impaired the proliferation of both lymphocytes and macrophages, an important step in atherosclerosis development. Therefore, telomere exhaustion resulting in replicative immunosenescence may serve as a mechanism for restricting atheroma progression.Peer reviewe

Analyzing Moodle/LMS logs to measure mobile access

Most Educational Institutions worldwide have deployed web based Learning Management Systems (LMS) as a means to provide support for their presence-based lectures and offer online-exclusive learning. These LMSs were designed and developed for users accessing the system through web browsers on desktop computers or laptops. However, over the last years, an increasing percentage of the registered accesses to various LMS platforms have been from mobile devices such as smartphones. While tackling the problems arising through the design of a mobile client for the Open Source LMS Moodle called Moodbile, the question of how to decide which services of Moodle could be accessed from smartphones became very relevant. This paper presents a data analysis study conducted on the Moodle server logs of the Universitat Politècnica de Catalunya-Barcelona Tech (UPC) virtual campus, Atenea, and the insight gained regarding the particular characteristics of the accesses from mobile devices. The main achievement of this study is that it provides insight of the use of the university LMS from mobile devices.Peer ReviewedPostprint (published version

Extending Moodle services to mobile devices: The Moodbile Project

Learning Management Systems (LMS) are widespread among most education and training institutions. Even though LMS are a mature technology, they have left the vanguard of innovation in e-learning to mobile devices and tablets. Mobile Learning (M-learning)may enhance e-learning by increasing communication and conversation opportunities to convents the learning process more collaborative and learner-centred. This paper describes a way to integrate mobile devices and educational applications with a LMS as Moodle through web services: The Moodbile Project. Rather than just creating mobile apps that replicates LMS functionalities on a mobile device, Moodbile provides to m-learning developers with the necessary tools to allow mobile devices to interact with the LMS. In this paper, we describe our proposal of an open specification of web services to support the integration of mobile external applications with Moodle.Peer ReviewedPostprint (published version

PeroxisomeDB: a database for the peroxisomal proteome, functional genomics and disease

Peroxisomes are essential organelles of eukaryotic origin, ubiquitously distributed in cells and organisms, playing key roles in lipid and antioxidant metabolism. Loss or malfunction of peroxisomes causes more than 20 fatal inherited conditions. We have created a peroxisomal database () that includes the complete peroxisomal proteome of Homo sapiens and Saccharomyces cerevisiae, by gathering, updating and integrating the available genetic and functional information on peroxisomal genes. PeroxisomeDB is structured in interrelated sections ‘Genes’, ‘Functions’, ‘Metabolic pathways’ and ‘Diseases’, that include hyperlinks to selected features of NCBI, ENSEMBL and UCSC databases. We have designed graphical depictions of the main peroxisomal metabolic routes and have included updated flow charts for diagnosis. Precomputed BLAST, PSI-BLAST, multiple sequence alignment (MUSCLE) and phylogenetic trees are provided to assist in direct multispecies comparison to study evolutionary conserved functions and pathways. Highlights of the PeroxisomeDB include new tools developed for facilitating (i) identification of novel peroxisomal proteins, by means of identifying proteins carrying peroxisome targeting signal (PTS) motifs, (ii) detection of peroxisomes in silico, particularly useful for screening the deluge of newly sequenced genomes. PeroxisomeDB should contribute to the systematic characterization of the peroxisomal proteome and facilitate system biology approaches on the organelle

High cut-off membrane for in- vivo dialysis of free plasma hemoglobin in a patient with massive hemolysis

Background: The possibility of clearing Cell-free Plasma Hemoglobin (CPH) from human plasma may appear attractive, especially when considering the noxious effects that CPH has on the immune function and the renal damage caused by its filtration. The existence of the so-called High Cut-Off (HCO) filters, possessing pores as big as 60 kDa, could potentially allow the clearance of the αβ dimers (31.3 kDa), the form in which the α2β2 hemoglobin tetramers (62.6 kDa) physiologically dissociate in plasma. We present herein the first reported case in which such an attempt was made. Case presentation: The patient was a 51-year-old man with hemolytic crisis due to glucose-6-phosphate dehydrogenase deficiency, further complicated by pigment-induced nephropathy. He underwent a 48-h CVVHD session, in which a HCO filter was used. The Sieving Coefficient (SC) for CPH was initially 0.08 and decreased to 0.02 after 24 h. This unexpected low SC was due to the initial high concentration of CPH (4.24 g/L). At such concentrations, the α2β2 tetramer poorly dissociates into the αβ dimer; but increases exponentially at concentrations lower than 1 g/L. Conclusions: Clearance of CPH through a HCO filter is technically feasible but its performance markedly relies on the initial concentration of CPH. Critically ill patients with smoldering hemolysis, as it happens during septic shock or ECMO treatment, may benefit the most from the use of this membrane in order to clear CPH

Clustering projects for eLearning interoperability

Since the beginning of the discipline, eLearning has been about innovation. New software, systems, contents and tools are being created and experimented with and in constant evolution. But when systems, contents and tools become successful and part of the regular infrastructure of educational institutions, interoperability becomes an issue. Systems that are consolidated and regularly used need to be able to interoperate with new ones. And the new tendencies need to fit within the current infrastructure. This paper states how several research and development projects with heterogeneous funding sources and locations worldwide, gathered together to find a solution to this common problem, providing open specifications and standards, plus Free/Libre, Open Source reference implementations.This work has been funded by the “Spanish Ministry of Science and Innovation” (http://micinn.es) in project LearningApps in the program INNPACTO 2010, the project MiPLE code TIN2010-21695-C02-02.8 and Google Research Award.Peer ReviewedPostprint (published version

Thrombotic microangiopathies assessment: mind the complement.

When faced withmicroangiopathic haemolytic anaemia, thrombocytopenia and organ dysfunction, clinicians should suspect thrombotic microangiopathy (TMA). The endothelial damage that leads to this histological lesion can be triggered by several conditions or diseases, hindering an early diagnosis and aetiological treatment. However, due to systemic involvement in TMA and its lowincidence, an accurate early diagnosis is often troublesome. In the last few decades,major improvements have been made in the pathophysiological knowledge of TMAs such as thrombotic thrombocytopenic purpura [TTP, caused by ADAMTS-13 (a disintegrin andmetalloproteinase with a thrombospondin Type 1motif,member 13) deficiency] and atypical haemolytic uraemic syndrome (aHUS, associated with dysregulation of the alternative complement pathway), together with enhancements in patientmanagement due to newdiagnostic tools and treatments. However, diagnosis of aHUS requires the exclusion of all the other entities that can cause TMA, delaying the introduction of terminal complement blockers, which have shown high efficacy in haemolysis control and especially in avoiding organ damage if used early. Importantly, there is increasing evidence that other forms of TMA could present overactivation of the complement system, worsening their clinical progression. This review addresses the diagnostic and therapeutic approach when there is clinical suspicion of TMA, emphasizing complement evaluation as a potential tool for the inclusive diagnosis of aHUS, as well as for the improvement of current knowledge of its pathophysiological involvement in other TMAs. The development of both new complement activation biomarkers and inhibitory treatments will probably improve themanagement of TMA patients in the near future, reducing response times and improving patient outcomes

RhoE is required for contact inhibition and negatively regulates tumor initiation and progression

RhoE is a small GTPase involved in the regulation of actin cytoskeleton dynamics, cell cycle and apoptosis. The role of RhoE in cancer is currently controversial, with reports of both oncogenic and tumor-suppressive functions for RhoE. Using RhoE-deficient mice, we show here that the absence of RhoE blunts contact-inhibition of growth by inhibiting p27 Kip1 nuclear translocation and cooperates in oncogenic transformation of mouse primary fibroblasts. Heterozygous RhoE +/gt mice are more susceptible to chemically induced skin tumors and RhoE knock-down results in increased metastatic potential of cancer cells. These results indicate that RhoE plays a role in suppressing tumor initiation and progression

Bortezomib decreases Rb phosphorylation and induces caspase-dependent apoptosis in Imatinib-sensitive and -resistant Bcr-Abl1-expressing cells

The use of c-abl-specific inhibitors such as Imatinib (IM) or Dasatinib has revolutionized the treatment of chronic myeloid leukemia (CML). However, a significant percentage of patients become resistant to IM. In this report, we have analyzed the possibility of using the proteasome as a molecular target in CML. Our results show that cells that express Bcr-Abl1 are more sensitive to the inhibition of the proteasome with Bortezomib (Btz) than control cells. This treatment reduces the proliferation of Bcr-Abl1- expressing cells, by inactivating NF-jB2 and decreasing the phosphorylation of Rb, eventually leading to an increase in caspase-dependent apoptosis. Furthermore, we show that Btz also induces cell-cycle arrest and apoptosis in cells expressing Bcr-Abl1 mutants that are resistant to IM. These results unravel a new molecular target of Btz, that is the Rb pathway, and open new possibilities in the treatment of CML especially for patients that become resistant to IM because of the presence of the T315I mutation