Arsenate Incorporation in Gypsum Probed by Neutron, X-ray Scattering and Density Functional Theory Modeling

International audienceThe ability of gypsum, a common sulfate mineral, to host arsenic atoms in its crystalline structure, is demonstrated through experimental structural studies of the solid solutions formed upon synthetic coprecipitation of gypsum (CaSO4 ·2H2O) and arsenic. Neutron and X-ray diffraction methods show an enlargement of the gypsum unit cell proportional to the concentration of arsenic in the solids and to the pH solution value. The substitution of sulfate ions (SO42-) by arsenate ions is shown to be more likely under alkaline conditions, where the HAsO42- species predominates. A theoretical Density Functional Theory model of the arsenicdoped gypsum structure reproduces the experimental volume expansion. Extended X-ray Absorption Fine Structure (EXAFS) measurements of the local structure around the arsenic atom in the coprecipitated solids confirm solid state substitution and allow some refinement of the local structure, corroborating the theoretical structure found in the simulations. The charge redistribution within the structure upon substitutions of either the protonated or the unprotonated arsenate species studied by means of Mulliken Population Analyses demonstrates an increase in the covalency in the interaction between Ca2+ and AsO4 3-, whereas the interaction between Ca2+ and HAsO4 2- remains predominantly ionic

Near-infrared fluorescence imaging as an alternative to bioluminescent bacteria to monitor biomaterial-associated infections

Biomaterial-associated infection is one of the most common complications related with the implantation of any biomedical device. Several in vivo imaging platforms have emerged as powerful diagnostic tools to longitudinally monitor biomaterial-associated infections in small animal models. In this study, we directly compared two imaging approaches: bacteria engineered to produce luciferase to generate bioluminescence and reactive oxygen species (ROS) imaging of the inflammatory response associated with the infected implant. We performed longitudinal imaging of bioluminescence associated with bacteria strains expressing plasmid-integrated luciferase driven by different promoters or a strain with the luciferase gene integrated into the chromosome. These luminescent strains provided adequate signal for acute (0–4 days) monitoring of the infection, but the bioluminescence signal decreased over time and leveled off by 7 days post-implantation. This loss in bioluminescence signal was attributed to changes in the metabolic activity of the bacteria. In contrast, near-infrared fluorescence imaging of ROS associated with inflammation to the implant provided sensitive and dose-dependent signals of biomaterialassociated bacteria. ROS imaging exhibited higher sensitivity than the bioluminescence imaging and was independent of the bacteria strain. Near-infrared fluorescence imaging of inflammatory responses represents a powerful alternative to bioluminescence imaging for monitoring biomaterial-associated bacterial infections.This work was supported by the Ministerio of Economía y Competitividad (BIO2010-21049, 201120E092), the U.S.A. National Institutes of Health grant R21 AI094624 (A.J.G.), the Georgia Tech/Emory Center for the Engineering of Living Tissues, the Atlanta Clinical and Translational Science Institute under PHS Grant UL RR025008 from the Clinical and Translational Science Award Program

Platelet releasate promotes skeletal myogenesis by increasing muscle stem cell commitment to differentiation and accelerates muscle regeneration following acute injury

Aim: The use of platelets as biomaterials has gained intense research interest. However, the mechanisms regarding platelet-mediated skeletal myogenesis remain to be established. The aim of this study was to determine the role of platelet releasate in skeletal myogenesis and muscle stem cell fate in vitro and ex vivo respectively. Methods: We analysed the effect of platelet releasate on proliferation and differentiation of C2C12 myoblasts by means of cell proliferation assays, immunohistochemistry, gene expression and cell bioenergetics. We expanded in vitro findings on single muscle fibres by determining the effect of platelet releasate on murine skeletal muscle stem cells using protein expression profiles for key myogenic regulatory factors. Results: TRAP6 and collagen used for releasate preparation had a more pronounced effect on myoblast proliferation versus thrombin and sonicated platelets (P<0.05). In addition, platelet concentration positively correlated with myoblast proliferation. Platelet releasate increased myoblast and muscle stem cell proliferation in a dose-dependent manner, which was mitigated by VEGFR and PDGFR inhibition. Inhibition of VEGFR and PDGFR ablated MyoD expression on proliferating muscle stem cells, compromising their commitment to differentiation in muscle fibres (P<0.001). Platelet releasate was detrimental for myoblast fusion and affected differentiation of myoblasts in a temporal manner. Most importantly we show that platelet releasate promotes skeletal myogenesis through the PDGF/VEGF-Cyclin D1-MyoD-Scrib-Myogenin axis and accelerates skeletal muscle regeneration after acute injury. Conclusion: This study provides novel mechanistic insights on the role of platelet releasate in skeletal myogenesis and set the physiological basis for exploiting platelets as biomaterials in regenerative medicine

Intensifying the manufacture of hiPSC therapy products through metabolic and process understanding

In vitro differentiation of human induced pluripotent stem cells into specific lineages such as cardiomyocytes (hPSC-CM) and hepatocytes (hPCS-Hep) is a crucial process to enable their application in cell therapy and drug discovery. Nevertheless, despite the remarkable efforts over the last decade towards the implementation of protocols for hPSC expansion and differentiation, there are some technological challenges remaining include the low scalability and differentiation yields. Additionally, generated cells are still immature, closely reminiscent of fetal/embryonic cells in what regards phenotype and function. In this study, we aim to overcome this hurdle by devising bioinspired and integrated strategies to improve the generation and functionality of these hiPSC-derivatives. We also applied robust multi-parametric techniques including proteomics, transcriptomics, metabolomics and fluxomics as complementary analytical tools to support bioprocess optimization and product characterization. We cultured hiPSC as 3D aggregates in stirred-tank bioreactors (STB) operated in perfusion and used a capacitance probe for in situ monitoring of cell growth/differentiation. After cell expansion, the hepatic differentiation step was integrated by addition of key soluble factors and controlling the dissolved oxygen concentration at various stages of the process to generate populations enriched for definitive endoderm, hepatocyte progenitors and mature hepatocytes. The analyses of hepatic markers expression throughout the stages of the differentiation confirmed that hepatocyte differentiation was improved in 3D spheroids when compared to 2D culture. Noteworthy, these hiPSC-HLC exhibited functional characteristics typical of hepatocytes (albumin production, glycogen storage and CYP450 activity). We also demonstrate the potential of dielectric spectroscopy to monitor cell expansion and hepatic differentiation in STB. For CM differentiation, we relied on the aggregation of hPSC-derived cardiac progenitors to establish a scalable differentiation protocol capable of generating highly pure CM aggregate cultures. We assessed if alteration of culture medium composition to mimic in vivo substrate usage during cardiac development improved further hPSC-CM maturation in vitro. Our results showed that shifting hPSC-CMs from glucose-containing to galactose- and fatty acid-containing medium promotes their fast maturation into adult-like CMs with higher oxidative metabolism, transcriptional signatures closer to those of adult ventricular tissue, higher myofibril density and alignment, improved calcium handling, enhanced contractility, and more physiological action potential kinetics. “-Omics” analyses showed that addition of galactose to culture medium and culturing the cells under perfusion improves total oxidative capacity of the cells and ameliorates fatty acid oxidation. This study demonstrated that metabolic shifts during differentiation/maturation of hPSC-CM are a cause, rather than a consequence, of the phenotypic and functional alterations observed. The metabolic-based strategy established herein holds technical and economic advantages over the existing protocols due to its scalability, simplicity and ease of application. Funding: This work was supported by FCT-funded projects NETDIAMOND (SAICTPAC/0047/2015), MetaCardio (Ref.032566) and FCT/ERA-Net (ERAdicatPH; Ref. E-Rare3/0002/2015). iNOVA4Health Research Unit (LISBOA-01-0145-FEDER-007344) is also acknowledged

The pharmaceutical use of permethrin: Sources and behavior during municipal sewage treatment

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 Springer Science+Business Media, LLC.Permethrin entered use in the 1970s as an insecticide in a wide range of applications, including agriculture, horticultural, and forestry, and has since been restricted. In the 21st century, the presence of permethrin in the aquatic environment has been attributed to its use as a human and veterinary pharmaceutical, in particular as a pedeculicide, in addition to other uses, such as a moth-proofing agent. However, as a consequence of its toxicity to fish, sources of permethrin and its fate and behavior during wastewater treatment are topics of concern. This study has established that high overall removal of permethrin (approximately 90%) was achieved during wastewater treatment and that this was strongly dependent on the extent of biological degradation in secondary treatment, with more limited subsequent removal in tertiary treatment processes. Sources of permethrin in the catchment matched well with measured values in crude sewage and indicated that domestic use accounted for more than half of the load to the treatment works. However, removal may not be consistent enough to achieve the environmental quality standards now being derived in many countries even where tertiary treatment processes are applied.United Utilities PL

Signaling pathways responsible for the rapid antidepressant-like effects of a GluN2A-preferring NMDA receptor antagonist

In a previous study we found that the preferring GluN2A receptor antagonist, NVP-AAM077, elicited rapid antidepressant-like effects in the forced swim test that was related to the release of glutamate and serotonin in the medial prefrontal cortex. In the present work we sought to examine the duration of this behavioral effect as well as the molecular readouts involved. Our results showed that NVP-AAM077 reduced the immobility in the forced swim test 30?min and 24?h after its administration. However, this effect waned 7 days later. The rapid antidepressant-like response seems to be associated with increases in the GluA1 subunit of ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, mammalian target of rapamycin (mTOR) signaling, glia markers such as glial fibrillary acidic protein (GFAP) and excitatory amino acid transporter 1 (EAAT1), and a rapid mobilization of intracellular stores of brain-derived neurotrophic factor (BDNF) in the medial prefrontal cortex.Acknowledgements: M.G.-S. was recipient of a contract from the Sistema Nacional de Garantía Juvenil co-funded by the European Social Fund. We also thank Novartis for the generous gift of NVP-AAM077. This work was supported by the Instituto de Salud Carlos III, Subdirección General del Evaluación y Fomento de la Investigación (FIS Grants PI13/00038 and PI16/00217) that were co-funded by the European Regional Development Fund (‘A way to build Europe’). Funding from the Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III is also acknowledged

The analysis of latent fingermarks on polymer banknotes using MALDI-MS

In September 2016, the UK adopted a new Bank of England (BoE) £5 polymer banknote, followed by the £10 polymer banknote in September 2017. They are designed to be cleaner, stronger and have increased counterfeit resilience; however, fingermark development can be problematic from the polymer material as various security features and coloured/textured areas have been found to alter the effectiveness of conventional fingermark enhancement techniques (FETs). As fingermarks are one of the most widely used forms of identification in forensic cases, it is important that maximum ridge detail be obtained in order to allow for comparison. This research explores the use of matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) profiling and imaging for the analysis of fingermarks deposited on polymer banknotes. The proposed methodology was able to obtain both physical and chemical information from fingermarks deposited in a range of scenarios including; different note areas, depletion series, aged samples and following conventional FETs. The analysis of forensically important molecular targets within these fingermarks was also explored, focussing specifically on cocaine. The ability of MALDI-MS to provide ridge detail and chemical information highlights the forensic applicability of this technique and potential for the analysis of fingermarks deposited onto this problematic surface

Transcriptional Evidence for the Role of Chronic Venlafaxine Treatment in Neurotrophic Signaling and Neuroplasticity Including also Glutatmatergic- and Insulin-Mediated Neuronal Processes.

OBJECTIVES: Venlafaxine (VLX), a serotonine-noradrenaline reuptake inhibitor, is one of the most commonly used antidepressant drugs in clinical practice for the treatment of major depressive disorder (MDD). Despite being more potent than its predecessors, similarly to them, the therapeutical effect of VLX is visible only 3-4 weeks after the beginning of treatment. Furthermore, recent papers show that antidepressants, including also VLX, enhance the motor recovery after stroke even in non depressed persons. In the present, transcriptomic-based study we looked for changes in gene expressions after a long-term VLX administration. METHODS: Osmotic minipumps were implanted subcutaneously into Dark Agouti rats providing a continuous (40 mg/kg/day) VLX delivery for three weeks. Frontal regions of the cerebral cortex were isolated and analyzed using Illumina bead arrays to detect genes showing significant chances in expression. Gene set enrichment analysis was performed to identify specific regulatory networks significantly affected by long term VLX treatment. RESULTS: Chronic VLX administration may have an effect on neurotransmitter release via the regulation of genes involved in vesicular exocytosis and receptor endocytosis (such as Kif proteins, Myo5a, Sv2b, Syn2 or Synj2). Simultaneously, VLX activated the expression of genes involved in neurotrophic signaling (Ntrk2, Ntrk3), glutamatergic transmission (Gria3, Grin2b and Grin2a), neuroplasticity (Camk2g/b, Cd47), synaptogenesis (Epha5a, Gad2) and cognitive processes (Clstn2). Interestingly, VLX increased the expression of genes involved in mitochondrial antioxidant activity (Bcl2 and Prdx1). Additionally, VLX administration also modulated genes related to insulin signaling pathway (Negr1, Ppp3r1, Slc2a4 and Enpp1), a mechanism that has recently been linked to neuroprotection, learning and memory. CONCLUSIONS: Our results strongly suggest that chronic VLX treatment improves functional reorganization and brain plasticity by influencing gene expression in regulatory networks of motor cortical areas. These results are consonant with the synaptic (network) hypothesis of depression and antidepressant-induced motor recovery after stroke

Base pairing interaction between 5′- and 3′-UTRs controls icaR mRNA translation in Staphylococcus aureus

UPNa. Instituto de Agrobiotecnología. Laboratorio de Biofilms Microbianos.Incluye 10 ficheros de datosThe presence of regulatory sequences in the 39 untranslated region (39-UTR) of eukaryotic mRNAs controlling RNA stability and translation efficiency is widely recognized. In contrast, the relevance of 39-UTRs in bacterial mRNA functionality has been disregarded. Here, we report evidences showing that around one-third of the mapped mRNAs of the major human pathogen Staphylococcus aureus carry 39-UTRs longer than 100-nt and thus, potential regulatory functions. We selected the long 39-UTR of icaR, which codes for the repressor of the main exopolysaccharidic compound of the S. aureus biofilm matrix, to evaluate the role that 39-UTRs may play in controlling mRNA expression. We showed that base pairing between the 39- UTR and the Shine-Dalgarno (SD) region of icaR mRNA interferes with the translation initiation complex and generates a double-stranded substrate for RNase III. Deletion or substitution of the motif (UCCCCUG) within icaR 39-UTR was sufficient to abolish this interaction and resulted in the accumulation of IcaR repressor and inhibition of biofilm development. Our findings provide a singular example of a new potential post-transcriptional regulatory mechanism to modulate bacterial gene expression through the interaction of a 39-UTR with the 59-UTR of the same mRNA.This work was supported by grants from Spanish Ministry of Economy and Competitiveness (BFU2011-23222, BIO2008-05284-C02-01 and ERA-NET Pathogenomics PIM2010EPA-00606) and from Fundação para a Ciência e Tecnologia - Portugal (ERA-PTG/0002/2010 and PEst-OE/EQB/LA0004/2011). IRdlM and JV were supported by F.P.I. (BES-2009-017410) and Ramón y Cajal (RYC-2009-03948) contracts, respectively, from the Spanish Ministry of Economy and Competitiveness