37 research outputs found

    Hypoxic and pharmacological activation of HIF inhibits SARS-CoV-2 infection of lung epithelial cells

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    COVID-19, caused by the novel coronavirus SARS-CoV-2, is a global health issue with more than 2 million fatalities to date. Viral replication is shaped by the cellular microenvironment, and one important factor to consider is oxygen tension, in which hypoxia inducible factor (HIF) regulates transcriptional responses to hypoxia. SARS-CoV-2 primarily infects cells of the respiratory tract, entering via its spike glycoprotein binding to angiotensin-converting enzyme 2 (ACE2). We demonstrate that hypoxia and the HIF prolyl hydroxylase inhibitor Roxadustat reduce ACE2 expression and inhibit SARS-CoV-2 entry and replication in lung epithelial cells via an HIF-1α-dependent pathway. Hypoxia and Roxadustat inhibit SARS-CoV-2 RNA replication, showing that post-entry steps in the viral life cycle are oxygen sensitive. This study highlights the importance of HIF signaling in regulating multiple aspects of SARS-CoV-2 infection and raises the potential use of HIF prolyl hydroxylase inhibitors in the prevention or treatment of COVID-19

    Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

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    We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

    Pollen morphology of the genus Eremanthus Less. (Vernonieae, Asteraceae)

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    In order to evaluate the significance of the pollen morphology for generic and infrageneric taxonomy of the genus Eremanthus (Vernonieae, Asteraceae), and to provide additional data for its phylogenetic reconstruction, the pollen of 20 of the 23 species of the genus was examined using light and scanning electron microscopy. Acetolysed pollen grains were measured, described, and illustrated using light microscopy, while non-acetolysed pollen grains were analyzed using scanning electron microscopy. Pollen grains of these species are isopolar, oblate-spheroidal in most of the species, more rarely prolate spheroidal or suboblate, subtriangular amb, tricolporate and subechinolophate. The variation among quantitative characters does not correlate with the macromorphological subdivision of the genus or with the generic or specific limits

    Adaptações de plantas submersas à absorção do carbono inorgânico Adaptations of submerged plants to inorganic carbon uptake

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    No presente trabalho são discutidos alguns aspectos teóricos dos mecanismos e adaptações empregados pela vegetação submersa para maximizar o aproveitamento do carbono inorgânico na água. O tipo de estratégia utilizada pelas macrófitas aquáticas submersas deve-se a diferenças genéticas entre as espécies e também às condições ambientais predominantes. Vários mecanismos fisiológicos e morfológicos, como a utilização do metabolismo C4, do ácido das crassuláceas (CAM), a utilização do bicarbonato (HCO3-), a utilização do CO2 da água intersticial do sedimento e o desenvolvimento de folhas aéreas foram considerados as principais adaptações para evitar a limitação do carbono no ambiente aquático. De relevância ecológica, a utilização destas diferentes estratégias pode compensar baixas ofertas de CO2 às taxas fotossintéticas de várias espécies submersas e suprimir a fotorrespiração por garantir altas concentrações intracelulares de CO2. Assim, estes mecanismos são responsáveis, em parte, pelo sucesso das macrófitas aquáticas submersas em ambientes oligotróficos, com baixas concentrações de CO2.<br>In this paper, the main theoretical aspects of the mechanisms and adaptations used by submerged vegetation to maximize the utilization of inorganic carbon are discussed. The type of strategy used by submerged plants is related to both genetic differences among species and environmental conditions. The use of C4 metabolism and crassulacean acid metabolism (CAM), uptake of bicarbonate (HCO3-), uptake of CO2 from interstitial (sediment) water and the development of aerial leaves are considered the main physiological and morphological adaptations to avoid CO2 limitation. These mechanisms are ecologically important given that their utilization overcome the low CO2 availability to several submerged species. In addition, they suppress the photorespiration by increasing the intracellular CO2 concentrations. Thus, these mechanisms are considered among the main reasons to explain the success of submerged plants even in CO2-poor, oligotrophic aquatic ecosystems
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