699 research outputs found

    Longitudinal performance of senescence accelerated mouse prone-strain 8 (SAMP8) mice in an olfactory-visual water maze challenge

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    © 2018 Lam, Takechi, Albrecht, D’Alonzo, Graneri, Hackett, Coulson, Fimognari, Nesbit and Mamo. Morris water maze (MWM) is widely used to assess cognitive deficits in pre-clinical rodent models. Latency time to reach escape platform is frequently reported, but may be confounded by deficits in visual acuity, or differences in locomotor activity. This study compared performance of Senescence Accelerated Mouse Prone-Strain 8 (SAMP8) and control Senescence Accelerated Mouse Resistant-Strain 1 (SAMR1) mice in classical MWM, relative to performance in a newly developed olfactory-visual maze testing protocol. Performance indicated as the escape time to rescue platform for classical MWM testing showed that SAMP8 mice as young as 6 weeks of age did poorly relative to age-matched SAMR1 mice. The olfactory-visual maze challenge described better discriminated SAMP8 vs. SAMR1 mice than classical MWM testing, based on latency time measures. Consideration of the distance traveled rather than latency time in the classical MWM found no treatment effects between SAMP8 and SAMR1 at 40 weeks of age and the olfactory-visual measures of performance confirmed the classical MWM findings. Longitudinal (repeat) assessment of SAMP8 and SAMR1 performance at 6, 20, 30, and 40 weeks of age in the olfactory-visual testing protocol showed no age-associated deficits in SAMP8 mice to the last age end-point indicated. Collectively, the results from this study suggest the olfactory-visual testing protocol may be advantageous compared to classical MWM as it avoids potential confounders of visual impairment in some strains of mice and indeed, may offer insight into cognitive and behavioral deficits that develop with advanced age in the widely used SAMP8 murine model

    CRISPR/Cas9 DNA cleavage at SNP-derived PAM enables both in vitro and in vivo KRT12 mutation-specific targeting

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    CRISPR/Cas9-based therapeutics hold the possibility for permanent treatment of genetic disease. The potency and specificity of this system has been used to target dominantly inherited conditions caused by heterozygous missense mutations through inclusion of the mutated base in the short-guide RNA (sgRNA) sequence. This research evaluates a novel approach for targeting heterozygous single-nucleotide polymorphisms (SNPs) using CRISPR/Cas9. We determined that a mutation within KRT12, which causes Meesmann's epithelial corneal dystrophy (MECD), leads to the occurrence of a novel protospacer adjacent motif (PAM). We designed an sgRNA complementary to the sequence adjacent to this SNP-derived PAM and evaluated its potency and allele specificity both in vitro and in vivo. This sgRNA was found to be highly effective at reducing the expression of mutant KRT12 mRNA and protein in vitro. To assess its activity in vivo we injected a combined Cas9/sgRNA expression construct into the corneal stroma of a humanized MECD mouse model. Sequence analysis of corneal genomic DNA revealed non-homologous end-joining repair resulting in frame-shifting deletions within the mutant KRT12 allele. This study is the first to demonstrate in vivo gene editing of a heterozygous disease-causing SNP that results in a novel PAM, further highlighting the potential for CRISPR/Cas9-based therapeutics

    Development of DYNAMIX Policy Mixes - Deliverable 4.2, revised version, of the DYNAMIX project

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    This report documents the development of the initial dynamic policy mixes that were developed for assessment in the DYNAMIX project. The policy mixes were designed within three different policy areas: overarching policy, land-use and food, and metals and other materials. The policy areas were selected to address absolute decoupling in general and, specifically, the DYNAMIX targets related to the use of virgin metals, the use of arable land and freshwater, the input of the nutrients nitrogen and phosphorus, and emissions of greenhouse gases. Each policy mix was developed within a separate author team, using a common methodological framework that utilize previous findings in the project. Specific drivers and barriers for resource use and resource efficiency are discussed in each policy area. Specific policy objectives and targets are also discussed before the actual policy mix is presented. Each policy mix includes a set of key instruments, which can be embedded in a wider set of supporting and complementary policy instruments. All key instruments are described in the report through responses to a set of predefined questions. The overarching mix includes a broad variety of key instruments. The land-use policy mix emphasizes five instruments to improve food production through, for example, revisions of already existing policy documents. It also includes three instruments to influence the food consumption and food waste. The policy mix on metals and other materials primarily aims at reducing the use of virgin metals through increased recycling, increased material efficiency and environmentally justified material substitution. To avoid simply shifting of burdens, it includes several instruments of an overarching character

    E–H Bond Activations and Hydrosilylation Catalysis with Iron and Cobalt Metalloboranes

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    An exciting challenge in transition metal catalyst design is to explore whether earth-abundant base metals such as Fe, Co, and Ni can mediate two-electron reductive transformations that their precious metal counterparts (e.g., Ru, Rh, Ir, and Pd) are better known to catalyze. Organometallic metalloboranes are an interesting design concept in this regard because they can serve as organometallic frustrated Lewis pairs. To build on prior studies with nickel metalloboranes featuring the DPB and ^(Ph)DPB^(Mes) ligands in the context of H_2 and silane activation and catalysis (DPB = bis(o-diisopropylphosphinophenyl)phenylborane, ^(Ph)DPB^(Mes) = bis(o-diphenylphosphinophenyl)mesitylborane), we now explore the reactivity of iron, [(DPB)Fe]_2(N_2), 1, and cobalt, (DPB)Co(N_2), 2, metalloboranes toward a series of substrates with E–H bonds (E = O, S, C, N) including phenol, thiophenol, benzo[h]quinoline, and 8-aminoquinoline. In addition to displaying high stoichiometric E–H bond activation reactivity, complexes 1 and 2 prove to be more active catalysts for the hydrosilylation of ketones and aldehydes with diphenylsilane relative to (^(Ph)DPB^(Mes))Ni. Indeed, 2 appears to be the most active homogeneous cobalt catalyst reported to date for the hydrosilylation of acetophenone under the conditions studied

    SEDLIN Forms Homodimers: Characterisation of SEDLIN Mutations and Their Interactions with Transcription Factors MBP1, PITX1 and SF1

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    BACKGROUND: SEDLIN, a 140 amino acid subunit of the Transport Protein Particle (TRAPP) complex, is ubiquitously expressed and interacts with the transcription factors c-myc promoter-binding protein 1 (MBP1), pituitary homeobox 1 (PITX1) and steroidogenic factor 1 (SF1). SEDLIN mutations cause X-linked spondyloepiphyseal dysplasia tarda (SEDT). METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effects of 4 missense (Asp47Tyr, Ser73Leu, Phe83Ser and Val130Asp) and the most C-terminal nonsense (Gln131Stop) SEDT-associated mutations on interactions with MBP1, PITX1 and SF1 by expression in COS7 cells. Wild-type SEDLIN was present in the cytoplasm and nucleus and interacted with MBP1, PITX1 and SF1; the SEDLIN mutations did not alter these subcellular localizations or the interactions. However, SEDLIN was found to homodimerize, and the formation of dimers between wild-type and mutant SEDLIN would mask a loss in these interactions. A mammalian SEDLIN null cell-line is not available, and the interactions between SEDLIN and the transcription factors were therefore investigated in yeast, which does not endogenously express SEDLIN. This revealed that all the SEDT mutations, except Asp47Tyr, lead to a loss of interaction with MBP1, PITX1 and SF1. Three-dimensional modelling studies of SEDLIN revealed that Asp47 resides on the surface whereas all the other mutant residues lie within the hydrophobic core of the protein, and hence are likely to affect the correct folding of SEDLIN and thereby disrupt protein-protein interactions. CONCLUSIONS/SIGNIFICANCE: Our studies demonstrate that SEDLIN is present in the nucleus, forms homodimers and that SEDT-associated mutations cause a loss of interaction with the transcription factors MBP1, PITX1 and SF1

    A novel role for CRIM1 in the corneal response to UV and pterygium development

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    Pterygium is a pathological proliferative condition of the ocular surface, characterised by formation of a highly vascularised, fibrous tissue arising from the limbus that invades the central cornea leading to visual disturbance and, if untreated, blindness. Whilst chronic ultraviolet (UV) light exposure plays a major role in its pathogenesis, higher susceptibility to pterygium is observed in some families, suggesting a genetic component. In this study, a Northern Irish family affected by pterygium but reporting little direct exposure to UV was identified carrying a missense variant in CRIM1 NM_016441.2: c.1235 A > C (H412P) through whole-exome sequencing and subsequent analysis. CRIM1 is expressed in the developing eye, adult cornea and conjunctiva, having a role in cell differentiation and migration but also in angiogenesis, all processes involved in pterygium formation. We demonstrate elevated CRIM1 expression in pterygium tissue from additional individual Northern Irish patients compared to unaffected conjunctival controls. UV irradiation of HCE-S cells resulted in an increase in ERK phosphorylation and CRIM1 expression, the latter further elevated by the addition of the MEK1/2 inhibitor, U0126. Conversely, siRNA knockdown of CRIM1 led to decreased UV-induced ERK phosphorylation and increased BCL2 expression. Transient expression of the mutant H412P CRIM1 in corneal epithelial HCE-S cells showed that, unlike wild-type CRIM1, it was unable to reduce the cell proliferation, increased ERK phosphorylation and apoptosis induced through a decrease of BCL2 expression levels. We propose here a series of intracellular events where CRIM1 regulation of the ERK pathway prevents UV-induced cell proliferation and may play an important role in the in the pathogenesis of pterygium

    Gα11 mutation in mice causes hypocalcemia rectifiable by calcilytic therapy

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    Heterozygous germline gain-of-function mutations of G-protein subunit α11 (Gα11), a signaling partner for the calcium-sensing receptor (CaSR), result in autosomal dominant hypocalcemia type 2 (ADH2). ADH2 may cause symptomatic hypocalcemia with low circulating parathyroid hormone (PTH) concentrations. Effective therapies for ADH2 are currently not available and a mouse model for ADH2 would help in assessment of potential therapies. We hypothesised that a previously reported dark skin mouse mutant (Dsk7), which has a germline hypermorphic Gα11 mutation, Ile62Val, may be a model for ADH2 and allow evaluation of calcilytics, which are CaSR negative allosteric modulators, as a targeted therapy for this disorder. Mutant Dsk7/+ and Dsk7/Dsk7 mice were shown to have hypocalcemia and reduced plasma PTH concentrations, similar to ADH2 patients. In vitro studies showed the mutant Val62 Gα11 to upregulate CaSR-mediated intracellular calcium and MAPK signaling, consistent with a gain-offunction. Treatment with NPS-2143, a calcilytic compound, normalised these signaling responses. In vivo, NPS-2143 induced a rapid and marked rise in plasma PTH and calcium concentrations in Dsk7/Dsk7 and Dsk7/+ mice, which became normocalcemic. Thus, these studies have established Dsk7 mice, which harbor a germline gain-of-function Gα11 mutation, as a model for ADH2; and demonstrated calcilytics as a potential targeted therapy

    Professionalism, Golf Coaching and a Master of Science Degree: A commentary

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    As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues
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