71 research outputs found

    Knock-in of Human BACE1 Cleaves Murine APP and Reiterates Alzheimer-like PhenoTypes

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    Footnotes We thank Roemex and the College for Life Science and Medicine at the University of Aberdeen for their generous support. The authors declare no competing financial interests.Peer reviewedPublisher PD

    Increasing levels of the endocannabinoid 2-AG is neuroprotective in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of Parkinson's disease

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    Date of Acceptance: 28/07/2015 The authors are grateful to the staff of the Medical Research Facility for their help with the animal care. This work was supported by the NHS Endowment fund 09/03 and the Wellcome Trust (WT080782MF). We thank Merck & Co. Inc., Rathway NJ, USA for the supply of DFU.Peer reviewedPublisher PD

    Apathy-like behaviour in tau mouse models of Alzheimer’s disease and frontotemporal dementia

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    Open Access via the Elsevier agreement This study was sponsored by WisTa Laboratories Ltd., Singapore. (grant PAR1577).Peer reviewedPublisher PD

    Knock-in of human BACE1 cleaves murine APP and reiterates alzheimer-like phenotypes

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    Key neuropathological hallmarks of Alzheimer's disease (AD) are elevated levels of amyloid β-peptide (Aβ) species generated via amyloid precursor protein (APP) endoproteolysis and cleavage by the rate-limiting β-site enzyme 1 (BACE1). Because rodents do not develop amyloid pathologies, we here investigated whether AD-like endophenotypes can be created in mice by expression of human bace1. To avoid pitfalls of existing models, we introduced hbace1 via knock-in under the control of the CaMKII α promoter into the safe HPRT locus. We report amyloidogenic processing of murine APP in the hBACE1 mice (termed PLB4), resulting in the formation of toxic APP metabolites that accumulate intra- and extraneuronally in hippocampus and cortex. Pronounced accumulation of Aβ*56 and Aβ hexamers in the absence of plaque deposition was detected in brain tissue from symptomatic PLB4 mice. Heightened levels of inflammation (gliosis) also appeared in several AD-related brain regions (dentate gyrus, hippocampal area CA1, piriform and parietal cortices) at 6 and 12 months of age. Behaviorally, deficits in habituation to a novel environment and semantic-like memory (social transmission of food preference) were detected from 3 to 4 months of age. Impairments in spatial learning strategies in long-term reference (water maze) and working memory (Y-maze) tasks presented at 6 months, and were distinct from reductions in locomotor activity and anxiety. Overall, our data indicate for the first time that targeted, subtle forebrain-specific expression through single gene knock-in of hBACE1 is sufficient to generate AD-relevant cognitive impairments amid corresponding histopathologies, confirming human BACE as the key parameter in amyloid pathogenesis.</p

    Mutant Tau knock-in mice display frontotemporal dementia relevant behaviour and histopathology

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    Models of Tau pathology related to frontotemporal dementia (FTD) are essential to determine underlying neurodegenerative pathologies and resulting tauopathy relevant behavioural changes. However, existing models are often limited in their translational value due to Tau overexpression, and the frequent occurrence of motor deficits which prevent comprehensive behavioural assessments. In order to address these limitations, a forebrain-specific (CaMKIIα promoter), human mutated Tau (hTauP301L + R406W) knock-in mouse was generated out of the previously characterised PLB1Triple mouse, and named PLB2Tau. After confirmation of an additional hTau species (~60 kDa) in forebrain samples, we identified age-dependent progressive Tau phosphorylation which coincided with the emergence of FTD relevant behavioural traits. In line with the non-cognitive symptomatology of FTD, PLB2Tau mice demonstrated early emerging (~6 months) phenotypes of heightened anxiety in the elevated plus maze, depressive/apathetic behaviour in a sucrose preference test and generally reduced exploratory activity in the absence of motor impairments. Investigations of cognitive performance indicated prominent dysfunctions in semantic memory, as assessed by social transmission of food preference, and in behavioural flexibility during spatial reversal learning in a home cage corner-learning task. Spatial learning was only mildly affected and task-specific, with impairments at 12 months of age in the corner learning but not in the water maze task. Electroencephalographic (EEG) investigations indicated a vigilance-stage specific loss of alpha power during wakefulness at both parietal and prefrontal recording sites, and site-specific EEG changes during non-rapid eye movement sleep (prefrontal) and rapid eye movement sleep (parietal). Further investigation of hippocampal electrophysiology conducted in slice preparations indicated a modest reduction in efficacy of synaptic transmission in the absence of altered synaptic plasticity. Together, our data demonstrate that the transgenic PLB2Tau mouse model presents with a striking behavioural and physiological face validity relevant for FTD, driven by the low level expression of mutant FTD hTau.</p

    Long-term home cage activity scans reveal lowered exploratory behaviour in symptomatic female Rett mice

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    &lt;p&gt;Numerous experimental models have been developed to reiterate endophenotypes of Rett syndrome, a neurodevelopmental disorder with a multitude of motor, cognitive and vegetative symptoms. Here, female Mecp2Stop mice [1] were characterised at mild symptomatic conditions in tests for anxiety (open field, elevated plus maze) and home cage observation systems for food intake, locomotor activity and circadian rhythms.&lt;/p&gt; &lt;p&gt;Aged 8–9 months, Mecp2Stop mice presented with heightened body weight, lower overall activity in the open field, but no anxiety phenotype. Although home cage activity scans conducted in two different observation systems, PhenoMaster and PhenoTyper, confirmed normal circadian activity, they revealed severely compromised habituation to a novel environment in all parameters registered including those derived from a non-linear decay model such as initial exploration maximum, decay half-life of activity and span, as well as plateau. Furthermore, overall activity was significantly reduced in nocturnal periods due to reductions in both fast ambulatory movements, but also a slow lingering. In contrast, light-period activity profiles during which the amount of sleep was highest remained normal in Mecp2Stop mice.&lt;/p&gt; &lt;p&gt;These data confirm the slow and progressive development of Rett-like symptoms in female Mecp2Stop mice resulting in a prominent reduction of overall locomotor activity, while circadian rhythms are maintained. Alterations in the time-course of habituation may indicate deficiencies in cognitive processing.&lt;/p&gt

    Synthesis of biolabile thioalkyl-protected phosphates from an easily accessible phosphotriester precursor

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    Robust methods for the synthesis of mixed phosphotriesters are essential to accelerate the development of novel phosphate-containing bioactive molecules. To enable efficient cellular uptake, phosphate groups are commonly masked with biolabile protecting groups, such as S-acyl-2-thioethyl (SATE) esters, that are removed once the molecule is inside the cell. Typically, bis-SATE-protected phosphates are synthesised through phosphoramidite chemistry. This approach, however, suffers from issues with hazardous reagents and can give unreliable yields, especially when applied to the synthesis of sugar-1-phosphate derivatives as tools for metabolic oligosaccharide engineering. Here, we report the development of an alternative approach that gives access to bis-SATE phosphotriesters in two steps from an easy to synthesise tri(2-bromoethyl)phosphotriester precursor. We demonstrate the viability of this strategy using glucose as a model substrate, onto which a bis-SATE-protected phosphate is introduced either at the anomeric position or at C6. We show compability with various protecting groups and further explore the scope and limitations of the methodology on different substrates, including N-acetylhexosamine and amino acid derivatives. The new approach facilitates the synthesis of bis-SATE-protected phosphoprobes and prodrugs and provides a platform that can boost further studies aimed at exploring the unique potential of sugar phosphates as research tools

    Genomewide association study of acute anterior uveitis identifies new susceptibility loci

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    Acknowledgments The authors thank all participating subjects with AS and healthy individuals who provided the DNA and clinical information necessary for this study. We would like to acknowledge the contributions of Anna Deminger, Sahlgrenska Academy at University of Gothenburg, and Urban Hellman, Umeå University, for their assistance in case recruitment and assessment and handling biological samples Funding Information: The survey was conducted by NatCen and the genomewide scan data were analyzed and deposited by the Wellcome Trust Sanger Institute. Information on how to access the data can be found on the Understanding Society website https: www. understandingsociety.ac.uk/ . We acknowledge and thank the TCRA AS Group for their support in recruiting patients for the study. M.A.B. is funded by a National Health and Medical Research Council (Australia) Senior Principal Research Fellowship, and support for this study was received from a National Health and Medical Research Council (Australia) program Grant (566938) and project Grant (569829), and from the Australian Cancer Research Foundation and Rebecca Cooper Medical Research Foundation. We are also very grateful for the invaluable support received from the National Ankylosing Spondylitis Society (UK) and Spondyloarthritis Association of America in case recruitment. Additional financial and technical support for patient recruitment was provided by the National Institute for Health Research Oxford Musculoskeletal Biomedical Research Unit and NIHR Thames Valley Comprehensive Local Research and an unrestricted educational grant from Abbott Laboratories. The authors acknowledge the sharing of data and samples by the BSRBR-AS Register in Aberdeen. Chief Investigator, Prof Gary Macfarlane and Dr Gareth Jones, Deputy Chief Investigator, created the BSRBR-AS study, which was commissioned by the British Society for Rheumatology, funded in part by Abbvie, Pfizer, and UCB. We are grateful to every patient, past and present staff of the BSRBR-AS register team, and to all clinical staff who recruited patients, followed them up and entered data – details here: https://www.abdn.ac.uk/iahs/research/ epidemiology/spondyloarthritis.php#panel1011. Funding was also received from the Swedish Research Council and The Swedish state under the agreement between the Swedish government and the county councils, the ALF agreement. The Irish data was derived from participants in ASRI – The Ankylosing Spondylitis Registry of Ireland, which is funded by unrestricted grants from Abbvie and Pfizer. Funding bodies involved played no role in the study design, performance, or preparation of this manuscript. Funding Information: X.F.H. was funded by the National Natural Science Foundation of China (31771390). The TASC study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) grants P01-052915, R01-AR046208. Funding was also received from the University of Texas Health Science Center at Houston CTSA grant UL1RR02418, Cedars-Sinai GCRC grant MO1-RR00425, Intramural Research Program, NIAMS/NIH, and Rebecca Cooper Foundation (Australia). This study was funded, in part, by Arthritis Research UK (Grants 19536 and 18797), by the Wellcome Trust (Grant number 076113), and by the Oxford Comprehensive Biomedical Research Centre ankylosing spondylitis chronic disease cohort (Theme Code: A91202). The New Zealand data was derived from participants in the Spondyloarthritis Genetics and the Environment Study (SAGE) and was funded by The Health Research Council, New Zealand. H.X. was funded by the National Natural Science Foundation of China Grant 81020108029 and 30872339. French sample collection was performed by the Groupe Française d’Etude Génétique des Spondylarthrites, coordinated by Professor Maxime Breban, and funded by the Agence Nationale de Recherche GEMISA grant reference ANR-10-MIDI-0002. We acknowledge the Understanding Society: The UK Household Longitudinal Study. This is led by the Institute for Social and Economic Research at the University of Essex and funded by the Economic and Social Research Council. Publisher Copyright: © 2020 Association for Research in Vision and Ophthalmology Inc.. All rights reserved.Peer reviewedPublisher PD
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