149 research outputs found
Similar Microbial Communities Found on Two Distant Seafloor Basalts.
The oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the LĆ'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR; 9°N). Phylogenetic analysis indicates the presence of a total of 43 bacterial and archaeal mono-phyletic groups, dominated by Alpha- and Gammaproteobacteria, as well as Thaumarchaeota. Functional gene analysis suggests that these Thaumarchaeota play an important role in ammonium oxidation on seafloor basalts. In addition to ammonium oxidation, the seafloor basalt habitat reveals a wide spectrum of other metabolic potentials, including CO2 fixation, denitrification, dissimilatory sulfate reduction, and sulfur oxidation. Basalt communities from LĆ'ihi and the EPR show considerable metabolic and phylogenetic overlap down to the genus level despite geographic distance and slightly different seafloor basalt mineralogy
Identification of a transporter complex responsible for the cytosolic entry of nitrogen-containing bisphosphonates
Nitrogen-containing-bisphosphonates (N-BPs) are widely prescribed to treat osteoporosis and other bone-related diseases. Although previous studies established that N-BPs function by inhibiting the mevalonate pathway in osteoclasts, the mechanism by which N-BPs enter the cytosol from the extracellular space to reach their molecular target is not understood. Here we implemented a CRISPRi-mediated genome-wide screen and identified SLC37A3 (solute carrier family 37 member A3) as a gene required for the action of N-BPs in mammalian cells. We observed that SLC37A3 forms a complex with ATRAID (all-trans retinoic acid-induced differentiation factor), a previously identified genetic target of N-BPs. SLC37A3 and ATRAID localize to lysosomes and are required for releasing N-BP molecules that have trafficked to lysosomes through fluid-phase endocytosis into the cytosol. Our results elucidate the route by which N-BPs are delivered to their molecular target, addressing a key aspect of the mechanism of action of N-BPs that may have significant clinical relevance
Meter-Scale Early Diagenesis of Organic Matter Buried Within Deep-Sea Sediments Beneath the Amazon River Plume
Gravity cores and multi-cores were collected from the Demerara Abyssal plain to examine meter-scale downcore features of early diagenesis in the sediments and relate them to the location of the Amazon River plume in the North Atlantic Ocean. At all sites, the oxygen penetration depth, inferred from nitrate and dissolved manganese profiles, was ~10â20 cm and nitrate was depleted within ~50 cm. However, most of the cores also had a secondary nitrate maximum (4â13 ÎŒM) at ~50 cm, at a location where we observed changes in gradients of dissolved manganese, iron, and ammonium. Although there is spatial heterogeneity in the profile behavior across the study, we do find subtle diagenetic profile patterns that occur in sediments in relation to their position below the Amazon plume. Dissolved silica profiles show an initial increase downcore, but then all show a decrease to depths of 30â100 cm, thereafter concentrations increase. We suggest this zone of silica uptake is due to reverse weathering processes, possibly involving iron oxidation. A semi-lithified iron crust appeared at nearly all sites, and its position is relict, likely an indicator of the transition from glacial to interglacial sediments
Notch regulates BMP responsiveness and lateral branching in vessel networks via SMAD6
Functional blood vessel growth depends on generation of distinct but coordinated responses from endothelial cells. Bone morphogenetic proteins (BMP), part of the TGFÎČ superfamily, bind receptors to induce phosphorylation and nuclear translocation of SMAD transcription factors (R-SMAD1/5/8) and regulate vessel growth. However, SMAD1/5/8 signalling results in both pro- and anti-angiogenic outputs, highlighting a poor understanding of the complexities of BMP signalling in the vasculature. Here we show that BMP6 and BMP2 ligands are pro-angiogenic in vitro and in vivo, and that lateral vessel branching requires threshold levels of R-SMAD phosphorylation. Endothelial cell responsiveness to these pro-angiogenic BMP ligands is regulated by Notch status and Notch sets responsiveness by regulating a cell-intrinsic BMP inhibitor, SMAD6, which affects BMP responses upstream of target gene expression. Thus, we reveal a paradigm for Notch-dependent regulation of angiogenesis: Notch regulates SMAD6 expression to affect BMP responsiveness of endothelial cells and new vessel branch formation
sFDvent: A global trait database for deepâsea hydrothermalâvent fauna
Motivation: Traits are increasingly being used to quantify global biodiversity patterns,
with trait databases growing in size and number, across diverse taxa. Despite growâ
ing interest in a traitâbased approach to the biodiversity of the deep sea, where the
impacts of human activities (including seabed mining) accelerate, there is no single reâ
pository for species traits for deepâsea chemosynthesisâbased ecosystems, including
hydrothermal vents. Using an international, collaborative approach, we have compiled
the first globalâscale trait database for deepâsea hydrothermalâvent fauna â sFDâ
vent (sDivâfunded trait database for the Functional Diversity of vents). We formed a
funded working group to select traits appropriate to: (a) capture the performance of
vent species and their influence on ecosystem processes, and (b) compare traitâbased
diversity in different ecosystems. Forty contributors, representing expertise across
most known hydrothermalâvent systems and taxa, scored species traits using online
collaborative tools and shared workspaces. Here, we characterise the sFDvent daâ
tabase, describe our approach, and evaluate its scope. Finally, we compare the sFDâ
vent database to similar databases from shallowâmarine and terrestrial ecosystems to
highlight how the sFDvent database can inform crossâecosystem comparisons. We
also make the sFDvent database publicly available online by assigning a persistent,
unique DOI.
Main types of variable contained: Six hundred and fortyâsix vent species names,
associated location information (33 regions), and scores for 13 traits (in categories:
community structure, generalist/specialist, geographic distribution, habitat use, life
history, mobility, species associations, symbiont, and trophic structure). Contributor
IDs, certainty scores, and references are also provided.
Spatial location and grain: Global coverage (grain size: ocean basin), spanning eight
ocean basins, including vents on 12 midâocean ridges and 6 backâarc spreading
centres.
Time period and grain: sFDvent includes information on deepâsea vent species, and
associated taxonomic updates, since they were first discovered in 1977. Time is not
recorded. The database will be updated every 5 years.
Major taxa and level of measurement: Deepâsea hydrothermalâvent fauna with speâ
ciesâlevel identification present or in progress.
Software format: .csv and MS Excel (.xlsx).This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
Mapping genetic vulnerabilities reveals BTK as a novel therapeutic target in oesophageal cancer
Objective Oesophageal cancer is the seventh most common cause of cancer-related death worldwide. Disease relapse is frequent and treatment options are limited. Design To identify new biomarker-defined therapeutic approaches for patients with oesophageal cancer, we integrated the genomic profiles of 17 oesophageal tumour-derived cell lines with drug sensitivity data from small molecule inhibitor profiling, identifying drug sensitivity effects associated with cancer driver gene alterations. We also interrogated recently described RNA interference screen data for these tumour cell lines to identify candidate genetic dependencies or vulnerabilities that could be exploited as therapeutic targets. Results By integrating the genomic features of oesophageal tumour cell lines with siRNA and drug screening data, we identified a series of candidate targets in oesophageal cancer, including a sensitivity to inhibition of the kinase BTK in MYC amplified oesophageal tumour cell lines. We found that this genetic dependency could be elicited with the clinical BTK/ERBB2 kinase inhibitor, ibrutinib. In both MYC and ERBB2 amplified tumour cells, ibrutinib downregulated ERK-mediated signal transduction, cMYC Ser-62 phosphorylation and levels of MYC protein, and elicited G(1) cell cycle arrest and apoptosis, suggesting that this drug could be used to treat biomarker-selected groups of patients with oesophageal cancer. Conclusions BTK represents a novel candidate therapeutic target in oesophageal cancer that can be targeted with ibrutinib. On the basis of this work, a proof-of-concept phase II clinical trial evaluating the efficacy of ibrutinib in patients with MYC and/or ERBB2 amplified advanced oesophageal cancer is currently underway (NCT02884453). Trial registration number NCT02884453; Pre-result
Brentuximab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone as frontline treatment for patients with CD30-positive B-cell lymphomas
We conducted a phase I/II multicenter trial using 6 cycles of brentuximab vedotin (BV) in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHP) for treatment of patients with CD30-positive (+) B-cell lymphomas. Thirty-one patients were evaluable for toxicity and 29 for efficacy including 22 with primary mediastinal B-cell lymphoma (PMBCL), 5 with diffuse large B-cell lymphoma (DLBCL), and 2 with gray zone lymphoma (GZL). There were no treatment-related deaths; 32% of patients had non-hematological grade 3/4 toxicities. The overall response rate was 100% (95% CI: 88-100) with 86% (95% CI: 68-96) of patients achieving complete response at the end of systemic treatment. Consolidative radiation following end of treatment response assessment was permissible and used in 52% of all patients including 59% of patients with PMBCL. With a median follow-up of 30 months, the 2-year progression-free survival (PFS) and overall survival (OS) were 85% (95% CI: 66-94) and 100%, respectively. In the PMBCL cohort, 2-year PFS was 86% (95% CI: 62-95). In summary, BV-R-CHP with or without consolidative radiation is a feasible and active frontline regimen for CD30+ B-cell lymphomas (NCT01994850)
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