94 research outputs found

    Lutetium(III) cyclo­tetra­phosphate

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    Single crystals of the title compound, tetra­lutetium(III) tris­(cyclo­tetra­phosphate), Lu4(P4O12)3, were obtained by solid-state reaction. The cubic structure is isotypic with its AlIII and ScIII analogues and is built up from four-membered (P4O12)4− phosphate ring anions ( symmetry), isolated from each other and further linked through isolated LuO6 octa­hedra (.3. symmetry) via corner sharing. Each LuO6 octa­hedron is linked to six (P4O12)4− rings, while each (P4O12)4− ring is linked to eight LuO6 octa­hedra

    An Inducible Expression System of the Calcium-Activated Potassium Channel 4 to Study the Differential Impact on Embryonic Stem Cells

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    Rationale. The family of calcium-activated potassium channels consists of four members with varying biological functions and conductances. Besides membrane potential modulation, SK channels have been found to be involved in cardiac pacemaker cell development from ES cells and morphological shaping of neural stem cells. Objective. Distinct SK channel subtype expression in ES cells might elucidate their precise impact during cardiac development. We chose SK channel subtype 4 as a potential candidate influencing embryonic stem cell differentiation. Methods. We generated a doxycycline inducible mouse ES cell line via targeted homologous recombination of a cassette expressing a bicistronic construct encoding SK4 and a fluorophore from the murine HPRT locus. Conclusion. We characterized the mouse ES cell line iSK4-AcGFP. The cassette is readily expressed under the control of doxycycline, and the overexpression of SK4 led to an increase in cardiac and pacemaker cell differentiation thereby serving as a unique tool to characterize the cell biological variances due to specific SK channel overexpression

    A defect in molybdenum cofactor binding causes an attenuated form of sulfite oxidase deficiency

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    Isolated sulfite oxidase deficiency (ISOD) is a rare recessive and infantile lethal metabolic disorder, which is caused by functional loss of sulfite oxidase (SO) due to mutations of the SUOX gene. SO is a mitochondrially localized molybdenum cofactor (Moco)- and heme-dependent enzyme, which catalyzes the vital oxidation of toxic sulfite to sulfate. Accumulation of sulfite and sulfite-related metabolites such as S-sulfocysteine (SSC) are drivers of severe neurodegeneration leading to early childhood death in the majority of ISOD patients. Full functionality of SO is dependent on correct insertion of the heme cofactor and Moco, which is controlled by a highly orchestrated maturation process. This maturation involves the translation in the cytosol, import into the intermembrane space (IMS) of mitochondria, cleavage of the mitochondrial targeting sequence, and insertion of both cofactors. Moco insertion has proven as the crucial step in this maturation process, which enables the correct folding of the homodimer and traps SO in the IMS. Here, we report on a novel ISOD patient presented at 17 months of age carrying the homozygous mutation NM_001032386.2 (SUOX):c.1097G > A, which results in the expression of SO variant R366H. Our studies show that histidine substitution of Arg366, which is involved in coordination of the Moco-phosphate, causes a severe reduction in Moco insertion efficacy in vitro and in vivo. Expression of R366H in HEK SUOX-/- cells mimics the phenotype of patient's fibroblasts, representing a loss of SO expression and specific activity. Our studies disclose a general paradigm for a kinetic defect in Moco insertion into SO caused by residues involved in Moco coordination resulting in the case of R366H in an attenuated form of ISO

    Wartime globalization in Asia, 1937-1945, conflicted connections and convergences

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    Given war's propensity for trampling over and demolishing borders—its literal, one might even say primordial, function as a motor of deterritorialization and reterritorialization—the scant scholarly attention paid to it as a globalizing force remains surprising. An extensive body of literature has responded to the complex role of globalization in the making, as well as the supposed unmaking, of conflict. Liberal economists and political theorists, in an intellectual lineage that dates back to the writings of the European Enlightenment, have made bold claims about global economic integration and the emergence of a ‘capitalist peace’. Critics of their arguments have pointed to the Western imperial violence which, from the mid-eighteenth century on, cleared the ground (and perhaps, more importantly, the seas) to make way for the so-called ‘free’ market world economy, a process which established several of those fundamental worldwide inequalities that have been perpetuated to this day. The hard evidence of a more recent past makes a mockery of the presumption that global capitalist enterprises such as Starbucks and McDonalds might bring about some kind of Big Mac and Frappuccino-mediated universal fraternity. Critical observers of globalization during the ‘Noughties’ (2000–2010) now recognize it as both one of the most interconnected decades in world history, and also one of the bloodiest.</jats:p

    Protein Kinase D2 Is an Essential Regulator of Murine Myoblast Differentiation

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    Muscle differentiation is a highly conserved process that occurs through the activation of quiescent satellite cells whose progeny proliferate, differentiate, and fuse to generate new myofibers. A defined pattern of myogenic transcription factors is orchestrated during this process and is regulated via distinct signaling cascades involving various intracellular signaling pathways, including members of the protein kinase C (PKC) family. The protein kinase D (PKD) isoenzymes PKD1, -2, and -3, are prominent downstream targets of PKCs and phospholipase D in various biological systems including mouse and could hence play a role in muscle differentiation. In the present study, we used a mouse myoblast cell line (C2C12) as an in vitro model to investigate the role of PKDs, in particular PKD2, in muscle stem cell differentiation. We show that C2C12 cells express all PKD isoforms with PKD2 being highly expressed. Furthermore, we demonstrate that PKD2 is specifically phosphorylated/activated during the initiation of mouse myoblast differentiation. Selective inhibition of PKCs or PKDs by pharmacological inhibitors blocked myotube formation. Depletion of PKD2 by shRNAs resulted in a marked inhibition of myoblast cell fusion. PKD2-depleted cells exhibit impaired regulation of muscle development-associated genes while the proliferative capacity remains unaltered. Vice versa forced expression of PKD2 increases myoblast differentiation. These findings were confirmed in primary mouse satellite cells where myotube fusion was also decreased upon inhibition of PKDs. Active PKD2 induced transcriptional activation of myocyte enhancer factor 2D and repression of Pax3 transcriptional activity. In conclusion, we identify PKDs, in particular PKD2, as a major mediator of muscle cell differentiation in vitro and thereby as a potential novel target for the modulation of muscle regeneration

    Structural Evolution of CO2-Filled Pure Silica LTA Zeolite under High-Pressure High-Temperature Conditions

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    [EN] The crystal structure of CO2-filled pure-SiO2 LTA zeolite has been studied at high pressures and temperatures using synchrotron-based X-ray powder diffraction. Its structure consists of 13 CO2 guest molecules, 12 of them accommodated in the large alpha-cages and one in the beta-cages, giving a SiO2/CO2 stoichiometric ratio smaller than 2. The structure remains stable under pressure up to 20 GPa with a slight pressure-dependent rhombohedral distortion, indicating that pressure-induced amorphization is prevented by the insertion of guest species in this open framework. The ambient temperature lattice compressibility has been determined. In situ high-pressure resistive-heating experiments up to 750 K allow us to estimate the thermal expansivity at P approximate to 5 GPa. Our data confirm that the insertion of CO2 reverses the negative thermal expansion of the empty zeolite structure. No evidence of any chemical reaction was observed. The possibility of synthesizing a silicon carbonate at high temperatures and higher pressures is discussed in terms of the evolution of C-O and Si-O distances between molecular and framework atoms.The authors thank the financial support of the Spanish Ministerio de Economia y Competitividad (MINECO), the Spanish Research Agency (AEI), and the European Fund for Regional Development (FEDER) under Grant Nos. MAT2016-75586-C4-1-P, MAT2015-71842-P, Severo Ochoa SEV-2012-0267, and No.MAT2015-71070-REDC (MALTA Consolider). D.S.-P. and J.R.-F. acknowledge MINECO for a Ramon y Cajal and a Juan de la Cierva contract, respectively. Portions of this work were performed at GeoSoilEnviroCARS (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory. GeoSoilEnviroCARS is supported by the National Science Foundation - Earth Sciences (EAR-1128799) and Department of Energy- GeoSciences (DE-FG02-94ER14466). This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Use of the COMPRES-GSECARS gas loading system was supported by COMPRES under NSF Cooperative Agreement EAR 11-57758. CO2 gas was also loaded at Diamond Light Source. Authors thank synchrotron ALBA-CELLS for beamtime allocation at MSPD line. British Crown Owned Copyright 2017/AWE. Published with permission of the Controller of Her Britannic Majesty's Stationery Office.Santamaria-Perez, D.; Marqueño, T.; Macleod, S.; Ruiz-Fuertes, J.; Daisenberger, D.; Chulia-Jordan, R.; Errandonea, D.... (2017). Structural Evolution of CO2-Filled Pure Silica LTA Zeolite under High-Pressure High-Temperature Conditions. Chemistry of Materials. 29(10):4502-4510. https://doi.org/10.1021/acs.chemmater.7b01158S45024510291

    The glutathione biosynthetic pathway of Plasmodium is essential for mosquito transmission

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    1Infection of red blood cells (RBC) subjects the malaria parasite to oxidative stress. Therefore, efficient antioxidant and redox systems are required to prevent damage by reactive oxygen species. Plasmodium spp. have thioredoxin and glutathione (GSH) systems that are thought to play a major role as antioxidants during blood stage infection. In this report, we analyzed a critical component of the GSH biosynthesis pathway using reverse genetics. Plasmodium berghei parasites lacking expression of gamma-glutamylcysteine synthetase (γ-GCS), the rate limiting enzyme in de novo synthesis of GSH, were generated through targeted gene disruption thus demonstrating, quite unexpectedly, that γ-GCS is not essential for blood stage development. Despite a significant reduction in GSH levels, blood stage forms of pbggcs− parasites showed only a defect in growth as compared to wild type. In contrast, a dramatic effect on development of the parasites in the mosquito was observed. Infection of mosquitoes with pbggcs− parasites resulted in reduced numbers of stunted oocysts that did not produce sporozoites. These results have important implications for the design of drugs aiming at interfering with the GSH redox-system in blood stages and demonstrate that de novo synthesis of GSH is pivotal for development of Plasmodium in the mosquito

    Primary cilia contribute to the aggressiveness of atypical teratoid/rhabdoid tumors

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    Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant brain tumor in infants that is characterized by loss of nuclear expression of SMARCB1 or SMARCA4 proteins. Recent studies show that AT/RTs comprise three molecular subgroups, namely AT/RT-TYR, AT/RT-MYC and AT/RT-SHH. The subgroups show distinct expression patterns of genes involved in ciliogenesis, however, little is known about the functional roles of primary cilia in the biology of AT/RT. Here, we show that primary cilia are present across all AT/RT subgroups with specific enrichment in AT/RT-TYR patient samples. Furthermore, we demonstrate that primary ciliogenesis contributes to AT/RT biology in vitro and in vivo. Specifically, we observed a significant decrease in proliferation and clonogenicity following disruption of primary ciliogenesis in AT/RT cell line models. Additionally, apoptosis was significantly increased via the induction of STAT1 and DR5 signaling, as detected by proteogenomic profiling. In a Drosophila model of SMARCB1 deficiency, concomitant knockdown of several cilia-associated genes resulted in a substantial shift of the lethal phenotype with more than 20% of flies reaching adulthood. We also found significantly extended survival in an orthotopic xenograft mouse model of AT/RT upon disruption of primary ciliogenesis. Taken together, our findings indicate that primary ciliogenesis or its downstream signaling contributes to the aggressiveness of AT/RT and, therefore, may constitute a novel therapeutic target

    Potential of Core-Collapse Supernova Neutrino Detection at JUNO

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    JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

    Detection of the Diffuse Supernova Neutrino Background with JUNO

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    As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
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