214 research outputs found

    UNA POLAROID DAL FUTURO: UNA NOTTE A SAN JUNIPERO

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    Un genere musicale (la dance), una serata al mese (nata per gioco) e un ricordo“eterno

    Direct conversion of human pluripotent stem cells into cranial motor neurons using a piggyBac vector

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    Human pluripotent stem cells (PSCs) are widely used for in vitro disease modeling. One of the challenges in the field is represented by the ability of converting human PSCs into specific disease-relevant cell types. The nervous system is composed of a wide variety of neuronal types with selective vulnerability in neurodegenerative diseases. This is particularly relevant for motor neuron diseases, in which different motor neurons populations show a different susceptibility to degeneration. Here we developed a fast and efficient method to convert human induced Pluripotent Stem Cells into cranial motor neurons of the branchiomotor and visceral motor subtype. These populations represent the motor neuron subgroup that is primarily affected by a severe form of amyotrophic lateral sclerosis with bulbar onset and worst prognosis. This goal was achieved by stable integration of an inducible vector, based on the piggyBac transposon, allowing controlled activation of Ngn2, Isl1 and Phox2a (NIP). The NIP module effectively produced electrophysiologically active cranial motor neurons. Our method can be easily extended to PSCs carrying disease-associated mutations, thus providing a useful tool to shed light on the cellular and molecular bases of selective motor neuron vulnerability in pathological conditions

    Importin-beta and CRM1 control a RANBP2 spatiotemporal switch essential for mitotic kinetochore function

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    Protein conjugation with small ubiquitin-related modifier (SUMO) is a post-translational modification that modulates protein interactions and localisation. RANBP2 is a large nucleoporin endowed with SUMO E3 ligase and SUMO-stabilising activity, and is implicated in some cancer types. RANBP2 is part of a larger complex, consisting of SUMO-modified RANGAP1, the GTP-hydrolysis activating factor for the GTPase RAN. During mitosis, the RANBP2–SUMO-RANGAP1 complex localises to the mitotic spindle and to kinetochores after microtubule attachment. Here, we address the mechanisms that regulate this localisation and how they affect kinetochore functions. Using proximity ligation assays, we find that nuclear transport receptors importin-β and CRM1 play essential roles in localising the RANBP2–SUMO-RANGAP1 complex away from, or at kinetochores, respectively. Using newly generated inducible cell lines, we show that overexpression of nuclear transport receptors affects the timing of RANBP2 localisation in opposite ways. Concomitantly, kinetochore functions are also affected, including the accumulation of SUMO- conjugated topoisomerase-IIα and stability of kinetochore fibres. These results delineate a novel mechanism through which nuclear transport receptors govern the functional state of kinetochores by regulating the timely deposition of RANBP2

    FUS mutant human motoneurons display altered transcriptome and microRNA pathways with implications for ALS pathogenesis

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    The FUS gene has been linked to amyotrophic lateral sclerosis (ALS). FUS is a ubiquitous RNA-binding protein, and the mechanisms leading to selective motoneuron loss downstream of ALS-linked mutations are largely unknown. We report the transcriptome analysis of human purified motoneurons, obtained from FUS wild-type or mutant isogenic induced pluripotent stem cells (iPSCs). Gene ontology analysis of differentially expressed genes identified significant enrichment of pathways previously associated to sporadic ALS and other neurological diseases. Several microRNAs (miRNAs) were also deregulated in FUS mutant motoneurons, including miR-375, involved in motoneuron survival. We report that relevant targets of miR-375, including the neural RNA-binding protein ELAVL4 and apoptotic factors, are aberrantly increased in FUS mutant motoneurons. Characterization of transcriptome changes in the cell type primarily affected by the disease contributes to the definition of the pathogenic mechanisms of FUS-linked ALS

    Quantum median filter for total variation image denoising

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    In this new computing paradigm, named quantum computing, researchers from all over the world are taking their first steps in designing quantum circuits for image process- ing, through a difficult process of knowledge transfer. This effort is named quantum image processing, an emerging research field pushed by powerful parallel comput- ing capabilities of quantum computers. This work goes in this direction and proposes the challenging development of a powerful method of image denoising, such as the total variation (TV) model, in a quantum environment. The proposed quantum TV is described and its sub-components are analysed. Despite the natural limitations of the current capabilities of quantum devices, the experimental results show a competitive denoising performance compared to the classical variational TV counterpar

    ALS mutant FUS proteins are recruited into stress granules in induced pluripotent stem cells- derived motoneurons

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    Patient-derived induced Pluripotent Stem Cells (iPSCs) provide an opportunity to study human diseases mainly in those cases where no suitable model systems are available. Here we have taken advantage of in vitro iPSCs derived from patients affected by Amyotrophic Lateral Sclerosis and carrying mutations in the RNA-binding proteins FUS to study the cellular behavior of the mutant proteins in the appropriate genetic background. Moreover, the ability to differentiate iPSCs into spinal cord neural cells provides an in vitro model mimicking the physiological conditions. iPSCs were derived from FUS(R514S) and FUS(R521C) patients' fibroblasts, while in the case of the severe FUS(P525L) mutation, where fibroblasts were not available, a heterozygous and a homozygous iPSC lines were raised by TALEN-directed mutagenesis. We show that aberrant localization and recruitment of FUS into stress granules (SGs) is a prerogative of the FUS mutant proteins and occurs only upon induction of stress in both undifferentiated iPSCs and spinal cord neural cells. Moreover, we show that the incorporation into SGs is proportional to the amount of cytoplasmic FUS, nicely correlating with the cytoplasmic delocalization phenotype of the different mutants. Therefore, the available iPSCs represent a very powerful system for understanding the correlation between FUS mutations, the molecular mechanisms of SG formation and ALS ethiopathogenesis

    Lab on a chip genotyping for Brucella spp. based on 15-loci multi locus VNTR analysis

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    <p>Abstract</p> <p>Background</p> <p>Brucellosis is an important zoonosis caused by the genus <it>Brucella</it>. In addition <it>Brucella </it>represents potential biological warfare agents due to the high contagious rates for humans and animals. Therefore, the strain typing epidemiological tool may be crucial for tracing back source of infection in outbreaks and discriminating naturally occurring outbreaks versus bioterroristic event. A Multiple Locus Variable-number tandem repeats (VNTR) Analysis (MLVA) assay based on 15 polymorphic markers was previously described. The obtained MLVA band profiles may be resolved by techniques ranging from low cost manual agarose gels to the more expensive capillary electrophoresis sequencing. In this paper a rapid, accurate and reproducible system, based on the Lab on a chip technology was set up for <it>Brucella </it>spp. genotyping.</p> <p>Results</p> <p>Seventeen DNA samples of <it>Brucella </it>strains isolated in Sicily, previously genotyped, and twelve DNA samples, provided by MLVA <it>Brucella </it>VNTR ring trial, were analyzed by MLVA-15 on Agilent 2100. The DNA fragment sizes produced by Agilent, compared with those expected, showed discrepancies; therefore, in order to assign the correct alleles to the Agilent DNA fragment sizes, a conversion table was produced. In order to validate the system twelve unknown DNA samples were analyzed by this method obtaining a full concordance with the VNTR ring trial results.</p> <p>Conclusion</p> <p>In this paper we described a rapid and specific detection method for the characterization of <it>Brucella </it>isolates. The comparison of the MLVA typing data produced by Agilent system with the data obtained by standard sequencing or ethidium bromide slab gel electrophoresis showed a general concordance of the results. Therefore this platform represents a fair compromise among costs, speed and specificity compared to any conventional molecular typing technique.</p

    Molecular evidence of Plasmodium vivax infection in Duffy negative symptomatic individuals from Dschang, West Cameroon

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    Background: Plasmodium vivax infection is known to be rare in West/Central Africa, the most accepted explanation being the lack of expression of erythroid Duffy antigen in the local human populations. Duffy negativity prevents the parasite to exploit the entry mechanism on the red blood cell surface. However, there are a growing number of reported vivax infections in Duffy-negative individuals. Data on P. vivax circulation in Cameroon are limited. The aim of the study was to evaluate the P. vivax presence, and its association with the Duffy genotype in West Cameroon. Results: Overall, 484 blood samples were collected consecutively from febrile outpatients attending the Dschang’s Hospital (West Cameroon) during a 3-months period. Plasmodium vivax infection was detected by PCR in 5.6% (n = 27/484) of the cases, representing 38.6% (n = 27/70) of all Plasmodium infections detected. All P. vivax infected individuals showed a Duffy-negative genotype, and the frequency of Duffy-positive individuals in the whole tested population was 1.7%. Conclusions: The results of this study confirm the circulation of P. vivax in Cameroon, as well as that the lack of expression of Duffy-antigen does not confer full protection against vivax malaria acquisition
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