47 research outputs found

    RNA Docking and Local Translation Regulate Site-Specific Axon Remodeling In Vivo

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    Nascent proteins can be positioned rapidly at precise subcellular locations by local protein synthesis (LPS) to facilitate localized growth responses. Axon arbor architecture, a major determinant of synaptic connectivity, is shaped by localized growth responses, but it is unknown whether LPS influences these responses in vivo. Using high-resolution live imaging, we examined the spatiotemporal dynamics of RNA and LPS in retinal axons during arborization in vivo. Endogenous RNA tracking reveals that RNA granules dock at sites of branch emergence and invade stabilized branches. Live translation reporter analysis reveals that de novo ß-actin hotspots colocalize with docked RNA granules at the bases and tips of new branches. Inhibition of axonal ß-actin mRNA translation disrupts arbor dynamics primarily by reducing new branch emergence and leads to impoverished terminal arbors. The results demonstrate a requirement for LPS in building arbor complexity and suggest a key role for pre-synaptic LPS in assembling neural circuits.This work was supported by Cambridge Trust, Croucher Foundation, Sir Edward Youde Memorial Fund (H.H.-W.W.), Gates Cambridge (J.Q.L.), Fundac¸ a˜ o para a Cieˆ ncia e Tecnologia (C.M.R.), Wellcome Trust Senior Investigator Award (100329/Z/ 12/Z) (W.A.H.), EPSRC Grant (EP/H018301/1), MRC Grant (MR/K015850/1 and MR/K02292X/1), Wellcome Trust (089703/Z/09/Z) (C.F.K.), Wellcome Trust Programme Grant (085314/Z/08/Z), and ERC Advanced Grant (322817) (C.E.H.)

    Linking Hydrothermal Geochemistry to Organismal Physiology: Physiological Versatility in Riftia pachyptila from Sedimented and Basalt-hosted Vents

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    Much of what is known regarding Riftia pachyptila physiology is based on the wealth of studies of tubeworms living at diffuse flows along the fast-spreading, basalt-hosted East Pacific Rise (EPR). These studies have collectively suggested that Riftia pachyptila and its chemoautotrophic symbionts are physiologically specialized, highly productive associations relying on hydrogen sulfide and oxygen to generate energy for carbon fixation, and the symbiont's nitrate reduction to ammonia for energy and biosynthesis. However, Riftia also flourish in sediment-hosted vents, which are markedly different in geochemistry than basalt-hosted systems. Here we present data from shipboard physiological studies and global quantitative proteomic analyses of Riftia pachyptila trophosome tissue recovered from tubeworms residing in the EPR and the Guaymas basin, a sedimented, hydrothermal vent field. We observed marked differences in symbiont nitrogen metabolism in both the respirometric and proteomic data. The proteomic data further suggest that Riftia associations in Guaymas may utilize different sulfur compounds for energy generation, may have an increased capacity for energy storage, and may play a role in degrading exogenous organic carbon. Together these data reveal that Riftia symbionts are far more physiologically plastic than previously considered, and that -contrary to previous assertions- Riftia do assimilate reduced nitrogen in some habitats. These observations raise new hypotheses regarding adaptations to the geochemical diversity of habitats occupied by Riftia, and the degree to which the environment influences symbiont physiology and evolution

    IL-10 from CD4+CD25−Foxp3−CD127− Adaptive Regulatory T Cells Modulates Parasite Clearance and Pathology during Malaria Infection

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    The outcome of malaria infection is determined, in part, by the balance of pro-inflammatory and regulatory immune responses. Failure to develop an effective pro-inflammatory response can lead to unrestricted parasite replication, whilst failure to regulate this response leads to the development of severe immunopathology. IL-10 and TGF-β are known to be important components of the regulatory response, but the cellular source of these cytokines is still unknown. Here we have examined the role of natural and adaptive regulatory T cells in the control of malaria infection and find that classical CD4+CD25hi (and Foxp3+) regulatory T cells do not significantly influence the outcome of infections with the lethal (17XL) strain of Plasmodium yoelii (PyL). In contrast, we find that adaptive IL-10-producing, CD4+ T cells (which are CD25−, Foxp3−, and CD127− and do not produce Th1, Th2, or Th17 associated cytokines) that are generated during both PyL and non-lethal P. yoelii 17X (PyNL) infections are able to down-regulate pro-inflammatory responses and impede parasite clearance. In summary, we have identified a population of induced Foxp3− regulatory (Tr1) T cells, characterised by production of IL-10 and down regulation of IL-7Rα, that modulates the inflammatory response to malaria

    A survey of the clinicopathological and molecular characteristics of patients with suspected Lynch syndrome in Latin America

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    Background: Genetic counselling and testing for Lynch syndrome (LS) have recently been introduced in several Latin America countries. We aimed to characterize the clinical, molecular and mismatch repair (MMR) variants spectrum of patients with suspected LS in Latin America. Methods: Eleven LS hereditary cancer registries and 34 published LS databases were used to identify unrelated families that fulfilled the Amsterdam II (AMSII) criteria and/or the Bethesda guidelines or suggestive of a dominant colorectal (CRC) inheritance syndrome. Results: We performed a thorough investigation of 15 countries and identified 6 countries where germline genetic testing for LS is available and 3 countries where tumor testing is used in the LS diagnosis. The spectrum of pathogenic MMR variants included MLH1 up to 54%, MSH2 up to 43%, MSH6 up to 10%, PMS2 up to 3% and EPCAM up to 0.8%. The Latin America MMR spectrum is broad with a total of 220 different variants which 80% were private and 20% were recurrent. Frequent regions included exons 11 of MLH1 (15%), exon 3 and 7 of MSH2 (17 and 15%, respectively), exon 4 of MSH6 (65%), exons 11 and 13 of PMS2 (31% and 23%, respectively). Sixteen international founder variants in MLH1, MSH2 and MSH6 were identified and 41 (19%) variants have not previously been reported, thus representing novel genetic variants in the MMR genes. The AMSII criteria was the most used clinical criteria to identify pathogenic MMR carriers although microsatellite instability, immunohistochemistry and family history are still the primary methods in several countries where no genetic testing for LS is available yet. Conclusion: The Latin America LS pathogenic MMR variants spectrum included new variants, frequently altered genetic regions and potential founder effects, emphasizing the relevance implementing Lynch syndrome genetic testing and counseling in all of Latin America countries.Radium Hospital Foundation (Oslo, Norway) in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, Helse Sør-Øst (Norway) in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, the French Association Recherche contre le Cancer (ARC) in the analysis, and interpretation of data, the Groupement des Entreprises Françaises dans la Lutte contre le Cancer (Gefluc) in the analysis, and interpretation of data, the Association Nationale de la Recherche et de la Technologie (ANRT, CIFRE PhD fellowship to H.T.) in the analysis, and interpretation of data and by the OpenHealth Institute in the analysis, and interpretation of data. Barretos Cancer Hospital received financial support by FINEP-CT-INFRA (02/2010)info:eu-repo/semantics/publishedVersio

    2 nd Brazilian Consensus on Chagas Disease, 2015

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    Abstract Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research
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