• Treating reading difficulties with colour [Editorial]

      Henderson, L.M.; Taylor, R.H.; Barrett, Brendan T.; Griffiths, P.G. (2014-08)
      Around 3-6% of children in the United Kingdom have substantial difficulties learning to read, a condition often referred to as dyslexia. They are at high risk of educational underachievement. In a 1996 editorial in The BMJ, Margaret Snowling argued that dyslexia is a verbal (not a visual) disorder.1 An accumulation of evidence supports this position and shows that reading difficulties are best dealt with by interventions that target underlying weaknesses in phonological language skills and letter knowledge.2 The 2009 Rose report, which provides guidance for professionals in schools on identifying and teaching young people with dyslexia and reading difficulties, stresses the importance of early, phonological interventions.3 Despite this evidence, dyslexia is often associated with subjective experiences of visual distortions that lead to discomfort during reading (sometimes termed visual stress). It has been argued that these symptoms can be alleviated by using coloured overlays and lenses.4 Symptoms of visual stress are not unique to dyslexia, and proponents do not claim that the use of colour directly addresses the underlying cause of the reading difficulty. However, they argue that the reduction in visual distortion brought about by a change in colour can improve reading accuracy and fluency.4
    • Treating reading difficulties with colour: Authors’ reply to Evans and Allen

      Griffiths, P.G.; Henderson, L.M.; Taylor, R.H.; Barrett, Brendan T. (2014-09-30)
      We thank Professors Evans and Allen for their interest in our article.1 2 The charity websites we reviewed refer to colour as though it offers a scientific, evidence based treatment; none referred to feedback from the membership. For example, one charity website makes the claim that “Research in the UK and in Australia shows that people who need coloured filters, who are said to have visual stress, need to have exactly the right colour.” This is incorrect. The research overwhelmingly shows little advantage, or at best conflicting results.3 4 5
    • Trends in pig product processing at British Neolithic Grooved Ware sites traced through organic residues in potsherds

      Mukherjee, A.J.; Gibson, Alex M.; Evershed, R.P. (2008)
      Gas chromatography (GC), GC-mass spectrometry (GC-MS) and GC-combustion-isotope ratio MS (GC-C-IRMS) analyses of absorbed and surface lipid residues preserved in potsherds were used to explore the extent of pig product processing exploitation in the later British Neolithic Grooved Ware tradition. Assessments were made regarding whether porcine lipids were associated with specific Grooved Ware traits, i.e. decoration, substyle, geographical area and type of site. Two hundred and twenty-two Grooved Ware potsherds were analysed, 70% of which contained lipid concentrations considered significant (>5 μg g−1). All the lipid residues were dominated by animal fats, although plant and beeswax were also detected in a small number of extracts. δ13C values of the major fatty acid components of degraded animal fats (C16:0 and C18:0) were determined for 126 extracts and used to assign ruminant or porcine origins to the residues; 16% of these were found to have a predominantly porcine isotope signature. Statistical associations with pig exploitation were shown to exist with substyle, geographical area and site type, whereas, no relationship was seen between decoration and the type of commodity processed. Intact triacylglycerols were preserved in 19% of the sherds; half of these had distributions consistent with the identifications based on δ13C values, the remainder differed either due to the presence of mixed commodities or because lower molecular weight homologues had been lost due to degradation. In addition to the detection of pig exploitation, results from lipid residue analysis showed a good correlation with faunal assemblages, suggesting that stable isotope analysis may be used as a proxy for animal exploitation at sites where bones have not survived.
    • Triad3A Regulates Synaptic Strength by Ubiquitination of Arc

      Mabb, A.M.; Je, H.S.; Wall, M.J.; Robinson, C.G.; Larsen, R.S.; Qiang, Y.; Corrêa, Sonia A.L.; Ehlers, M.D.; (2014-06-18)
      Activity-dependent gene transcription and protein synthesis underlie many forms of learning-related synaptic plasticity. At excitatory glutamatergic synapses, the immediate early gene product Arc/ Arg3.1 couples synaptic activity to postsynaptic endocytosis of AMPA-type glutamate receptors. Although the mechanisms for Arc induction have been described, little is known regarding the molecular machinery that terminates Arc function. Here, we demonstrate that the RING domain ubiquitin ligase Triad3A/RNF216 ubiquitinates Arc, resulting in its rapid proteasomal degradation. Triad3A associates with Arc, localizes to clathrin-coated pits, and is associated with endocytic sites in dendrites and spines. In the absence of Triad3A, Arc accumulates, leading to the loss of surface AMPA receptors. Furthermore, loss of Triad3A mimics and occludes Arc-dependent forms of synaptic plasticity. Thus, degradation of Arc by clathrin-localized Triad3A regulates the availability of synaptic AMPA receptors and temporally tunes Arc-mediated plasticity at glutamatergic synapses.
    • Trichohyalin is a potential major autoantigen in human alopecia areata

      Leung, Man Ching; Sutton, Chris W.; Fenton, D.A.; Tobin, Desmond J. (2010)
      Several lines of evidence support an autoimmune basis for alopecia areata (AA), a common putative autoimmune hair loss disorder. However, definitive support is lacking largely because the identity of hair follicle (HF) autoantigen(s) involved in its pathogenesis remains unknown. Here, we isolated AA-reactive HF-specific antigens from normal human scalp anagen HF extracts by immunoprecipitation using serum antibodies from 10 AA patients. Samples were analyzed by LC-MALDI-TOF/TOF mass spectrometry, which indicated strong reactivity to the hair growth phase-specific structural protein trichohyalin in all AA sera. Keratin 16 (K16) was also identified as another potential AA-relevant target HF antigen. Double immunofluorescence studies using AA (and control sera) together with a monoclonal antibody to trichohyalin revealed that AA sera contained immunoreactivity that colocalized with trichohyalin in the growth phase-specific inner root sheath of HF. Furthermore, a partial colocalization of AA serum reactivity with anti-K16 antibody was observed in the outer root sheath of the HF. In summary, this study supports the involvement of an immune response to anagen-specific HFs antigens in AA and specifically suggests that an immune response to trichohyalin and K16 may have a role in the pathogenesis of the enigmatic disorder.
    • Tristearin bilayers: structure of the aqueous interface and stability in the presence of surfactants

      Hughes, Zak E.; Walsh, T.R. (2015-05-29)
      We report results of atomistic molecular dynamics simulations of an industrially-relevant, exemplar triacylglycerol (TAG), namely tristearin (TS), under aqueous conditions, at different temperatures and in the presence of an anionic surfactant, sodium dodecylbenzene sulphonate (SDBS). We predict the TS bilayers to be stable and in a gel phase at temperatures of 350 K and below. At 370 K the lipid bilayer was able to melt, but does not feature a stable liquid–crystalline phase bilayer at this elevated temperature. We also predict the structural characteristics of TS bilayers in the presence of SDBS molecules under aqueous conditions, where surfactant molecules are found to spontaneously insert into the TS bilayers. We model TS bilayers containing different amounts of SDBS, with the presence of SDBS imparting only a moderate effect on the structure of the system. Our study represents the first step in applying atomistic molecular dynamics simulations to the investigation of TAG-aqueous interfaces. Our results suggest that the CHARMM36 force-field appears suitable for the simulation of such systems, although the phase behaviour of the system may be shifted to lower temperatures than is the case for the actual system. Our findings provide a foundation for further simulation studies of the TS-aqueous interface.
    • TRPA1- FGFR2 binding event is a regulatory oncogenic driver modulated by miRNA-142-3p

      Berrout, J.; Kyriakopoulou, E.; Moparthi, L.; Hogea, A.S.; Berrout, L.; Ivan, C.; Lorger, M.; Boyle, J.; Peers, C.; Muench, S.; et al. (2017-10)
      Recent evidence suggests that the ion channel TRPA1 is implicated in lung adenocarcinoma (LUAD) where its role and mechanism of action remain unknown. We have previously established that the membrane receptor FGFR2 drives LUAD progression through aberrant protein-protein interactions mediated via its C-terminal proline rich motif. Here, we report that the N-terminal ankyrin repeats of TRPA1 directly bind to the C-terminal proline rich motif of FGFR2 inducing the constitutive activation of the receptor, thereby prompting LUAD progression and metastasis. Furthermore, we show that upon metastasis to the brain, TRPA1 gets depleted, an effect triggered by the transfer of TRPA1-targeting exosomal microRNA (miRNA-142-3p) from brain astrocytes to cancer cells. This downregulation, in turn, inhibits TRPA1-mediated activation of FGFR2 hindering the metastatic process. Our study reveals a direct binding event and characterizes the role of TRPA1 ankyrin repeats in regulating FGFR2-driven oncogenic process; a mechanism that is hindered by miRNA-142-3p.
    • Truncated azinomycin analogues intercalate into DNA.

      Casely-Hayford, M.A.; Pors, Klaus; Patterson, Laurence H.; Gerner, C.; Neidle, S.; Searcey, M. (2005)
      The design and synthesis of a potentially more therapeutically-viable azinomycin analogue 4 based upon 3 has been completed. It involved coupling of a piperidine mustard to the acid chloride of the azinomycin chromophore. Both the designed azinomycin analogue 4 and the natural product 3 bind to DNA and cause unwinding, supporting an intercalative mode of binding. Graphical abstract A designed analogue of the left half of azinomycin has been synthesized and unwinds supercoiled DNA.
    • Tuberculosis resistance-conferring mutations with fitness cost among HIV-positive individuals in Uganda

      Ssengooba, W.; Lukoye, D.; Meehan, Conor J.; Kateete, D.P.; Joloba, M.L.; de Jong, B.C.; Cobelens, F.G.; van Leth, F. (2017-05-01)
      BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is considered to be less transmissible due to the fitness cost associated with drug resistance-conferring mutations in essential genes. OBJECTIVE: To test the hypothesis that TB drug resistance-conferring mutations with fitness cost are more frequent among human immunodeficiency virus (HIV) positive than among HIV-negative patients. DESIGN: We analysed all strains from the two TB drug resistance surveys conducted in Uganda between 2008 and 2011. Strains phenotypically susceptible to rifampicin and/or isoniazid were assumed to be wild-type; in all other cases, we performed whole-genome sequencing. Mutations at the rpoB531 and katG315 codons were considered without fitness loss, whereas other rpoB codons and non-katG were considered with fitness loss. RESULTS: Of the 897 TB patients, 286 (32.1%) were HIV-positive. Mutations with fitness loss in HIV-positive and HIV-negative patients were respectively as follows: non-531 rpoB: 1.03% (n = 3), 0.71% (n = 4) (OR 1.46, 95%CI 0.58-3.68); non-katG: 0.40% (n = 1), 1.0% (n = 6) (OR 0.40, 95%CI 0.07-2.20); rpoB531: 1.49% (n = 4), 0.69% (n = 4) (OR 2.29, 95%CI 0.83-5.77); katG315: 3.86% (n = 11), 2.55% (n = 15) (OR 1.54, 95%CI 0.81-2.90). The odds of mutations with and without fitness cost were higher for patients with a history of previous anti-tuberculosis treatment. CONCLUSIONS: Our data do not support the hypothesis that resistance-conferring mutations with fitness cost are likely to be often present in HIV-positive individuals.
    • Tubulin-binding dibenz[c,e]oxepines. Part 2. 1 Structural variation and biological evaluation as tumour vasculature disrupting agents

      Rossington, S.B.; Hadfield, J.A.; Shnyder, Steven D.; Wallace, T.W.; Williams, K.J. (2017-03-01)
      5,7-Dihydro-3,9,10,11-tetramethoxybenz[c,e]oxepin-4-ol 1, prepared from a dibenzyl ether precursor via Pd-catalysed intramolecular direct arylation, possesses broad-spectrum in vitro cytotoxicity towards various tumour cell lines, and induces vascular shutdown, necrosis and growth delay in tumour xenografts in mice at sub-toxic doses. The biological properties of 1 and related compounds can be attributed to their ability to inhibit microtubule assembly at the micromolar level, by binding reversibly to the same site of the tubulin αβ-heterodimer as colchicine 2 and the allocolchinol, N-acetylcolchinol 4.
    • Tumor growth suppression using a combination of taxol-based therapy and GSK3 inhibition in non-small cell lung cancer

      O'Flaherty, L.; Shnyder, Steven D.; Cooper, Patricia A.; Cross, S.J.; Wakefield, J.G.; Pardo, O.E.; Seckl, M.J.; Tavare, J.M. (2019-04-10)
      Glycogen synthase kinase-3 (GSK3) is over-expressed and hyperactivated in non-small cell lung carcinoma (NSCLC) and plays a role in ensuring the correct alignment of chromosomes on the metaphase plate during mitosis through regulation of microtubule stability. This makes the enzyme an attractive target for cancer therapy. We examined the effects of a selective cell-permeant GSK3 inhibitor (CHIR99021), used alone or in combination with paclitaxel, using an in vitro cell growth assay, a quantitative chromosome alignment assay, and a tumor xenograft model. CHIR99021 inhibits the growth of human H1975 and H1299 NSCLC cell lines in a synergistic manner with paclitaxel. CHIR99021 and paclitaxel promoted a synergistic defect in chromosomal alignment when compared to each compound administered as monotherapy. Furthermore, we corroborated our in vitro findings in a mouse tumor xenograft model. Our results demonstrate that a GSK3 inhibitor and paclitaxel act synergistically to inhibit the growth of NSCLC cells in vitro and in vivo via a mechanism that may involve converging modes of action on microtubule spindle stability and thus chromosomal alignment during metaphase. Our findings provide novel support for the use of the GSK3 inhibitor, CHIR99021, alongside taxol-based chemotherapy in the treatment of human lung cancer.
    • Tumor matrix stiffness promotes metastatic cancer cell interaction with the endothelium

      Reid, SE; Kay, EJ; Neilson, LJ; Henze, AT; Serneels, J; McGhee, EJ; Dhayade, S; Nixon, C; Mackey, JB; Santi, A; et al. (2017-08-15)
      Tumor progression alters the composition and physical properties of the extracellular matrix. Particularly, increased matrix stiffness has profound effects on tumor growth and metastasis. While endothelial cells are key players in cancer progression, the influence of tumor stiffness on the endothelium and the impact on metastasis is unknown. Through quantitative mass spectrometry, we find that the matricellular protein CCN1/CYR61 is highly regulated by stiffness in endothelial cells. We show that stiffness-induced CCN1 activates β-catenin nuclear translocation and signaling and that this contributes to upregulate N-cadherin levels on the surface of the endothelium, in vitro This facilitates N-cadherin-dependent cancer cell-endothelium interaction. Using intravital imaging, we show that knockout of Ccn1 in endothelial cells inhibits melanoma cancer cell binding to the blood vessels, a critical step in cancer cell transit through the vasculature to metastasize. Targeting stiffness-induced changes in the vasculature, such as CCN1, is therefore a potential yet unappreciated mechanism to impair metastasis.
    • Tumor-Targeted Prodrug ICT2588 Demonstrates Therapeutic Activity Against Solid Tumors and Reduced Potential For Cardiovascular Toxicity

      Gill, Jason H.; Loadman, Paul M.; Shnyder, Steven D.; Cooper, Patricia A.; Atkinson, Jennifer M.; Ribeiro Morais, Goreti; Patterson, Laurence H.; Falconer, Robert A. (2014-03-18)
      Development of therapeutic strategies for tumor-selective delivery of therapeutics through exploitation of the proteolytic tumor phenotype has significant scope for improvement of cancer treatment. ICT2588 is a peptide-conjugated prodrug of the vascular disrupting agent (VDA) azademethylcolchicine developed to be selectively hydrolyzed by matrix metalloproteinase-14 (MMP-14) within the tumor. In this report, we extend our previous proof-of-concept studies and demonstrate the therapeutic potential of this agent against models of human colorectal, lung, breast, and prostate cancer. In all tumor types, ICT2588 was superior to azademethylcolchicine and was greater or comparable to standard clinically used agents for the respective tumor type. Prodrug activation in clinical human lung tumor homogenates relative to stability in human plasma and liver was observed, supporting clinical translation potential. A major limiting factor to the clinical value of VDAs is their inherent cardiovascular toxicity. No increase in plasma von Willebrand factor (vWF) levels, an indicator of systemic vascular dysfunction and acute cardiovascular toxicity, was detected with ICT2588, thereby supporting the tumor-selective activation and reduced potential of ICT2588 to cause cardiovascular toxicity. Our findings reinforce the improved therapeutic index and tumorselective approach offered by ICT2588 and this nanotherapeutic approach.
    • Tumour necrosis factor alpha induces rapid reduction in AMPA receptor-mediated calcium entry in motor neurones by increasing cell surface expression of the GluR2 subunit: relevance to neurodegeneration

      Rainey-Smith, S.R.; Andersson, D.A.; Williams, R.J.; Rattray, Marcus (2010)
      The alpha-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (AMPAR) subunit GluR2, which regulates excitotoxicity and the inflammatory cytokine tumour necrosis factor alpha (TNFalpha) have both been implicated in motor neurone vulnerability in amyotrophic lateral sclerosis/motor neurone disease. TNFalpha has been reported to increase cell surface expression of AMPAR subunits to increase synaptic strength and enhance excitotoxicity, but whether this mechanism occurs in motor neurones is unknown. We used primary cultures of mouse motor neurones and cortical neurones to examine the interaction between TNFalpha receptor activation, GluR2 availability, AMPAR-mediated calcium entry and susceptibility to excitotoxicity. Short exposure to a physiologically relevant concentration of TNFalpha (10 ng/mL, 15 min) caused a marked redistribution of both GluR1 and GluR2 to the cell surface as determined by cell surface biotinylation and immunofluorescence. Using fura-2-acetoxymethyl ester microfluorimetry, we showed that exposure to TNFalpha caused a rapid reduction in the peak amplitude of AMPA-mediated calcium entry in a PI3-kinase and p38 kinase-dependent manner, consistent with increased insertion of GluR2-containing AMPAR into the plasma membrane. This resulted in a protection of motor neurones against kainate-induced cell death. Our data therefore, suggest that TNFalpha acts primarily as a physiological regulator of synaptic activity in motor neurones rather than a pathological drive in amyotrophic lateral sclerosis.
    • Tunable supramolecular gel properties by varying thermal history

      Debnath, S.; Roy, S.; Abul-Haija, Y.M.; Frederix, P.W.J.M.; Ramalhete, S.M.; Hirst, A.R.; Javid, Nadeem; Hunt, N.T.; Kelly, S.M.; Angulo, J.; et al. (2019-06-12)
      The possibility of using differential pre‐heating prior to supramolecular gelation to control the balance between hydrogen‐bonding and aromatic stacking interactions in supramolecular gels and obtain consequent systematic regulation of structure and properties is demonstrated. Using a model aromatic peptide amphiphile, Fmoc‐tyrosyl‐leucine (Fmoc‐YL) and a combination of fluorescence, infrared, circular dichroism and NMR spectroscopy, it is shown that the balance of these interactions can be adjusted by temporary exposure to elevated temperatures in the range 313–365 K, followed by supramolecular locking in the gel state by cooling to room temperature. Distinct regimes can be identified regarding the balance between H‐bonding and aromatic stacking interactions, with a transition point at 333 K. Consequently, gels can be obtained with customizable properties, including supramolecular chirality and gel stiffness. The differential supramolecular structures also result in changes in proteolytic stability, highlighting the possibility of obtaining a range of supramolecular architectures from a single molecular structure by simply controlling the pre‐assembly temperature.
    • Tunable Supramolecular Hydrogels for Selection of Lineage-Guiding Metabolites in Stem Cell Cultures

      Alakpa, E.V.; Jayawarna, V.; Lampel, A.; Burgess, K.V.; West, C.C.; Bakker, S.C.J.; Roy, S.; Javid, Nadeem; Fleming, S.; Lamprou, D.A.; et al. (2016-08-11)
      Stem cells are known to differentiate in response to the chemical and mechanical properties of the substrates on which they are cultured. Thus, supramolecular biomaterials with tunable properties are well suited for the study of stem cell differentiation. In this report, we exploited this phenomenon by combining stem cell differentiation in hydrogels with variable stiffness and metabolomics analysis to identify specific bioactive lipids that are uniquely used up during differentiation. To achieve this, we cultured perivascular stem cells on supramolecular peptide gels of different stiffness, and metabolite depletion followed. On soft (1 kPa), stiff (13 kPa), and rigid (32 kPa) gels, we observed neuronal, chondrogenic, and osteogenic differentiation, respectively, showing that these stem cells undergo stiffness-directed fate selection. By analyzing concentration variances of >600 metabolites during differentiation on the stiff and rigid gels (and focusing on chondrogenesis and osteogenesis as regenerative targets, respectively), we identified that specific lipids (lysophosphatidic acid and cholesterol sulfate, respectively), were significantly depleted. We propose that these metabolites are therefore involved in the differentiation process. In order to unequivocally demonstrate that the lipid metabolites that we identified play key roles in driving differentiation, we subsequently demonstrated that these individual lipids can, when fed to standard stem cell cultures, induce differentiation toward chondrocyte and osteoblast phenotypes. Our concept exploits the design of supramolecular biomaterials as a strategy for discovering cell-directing bioactive metabolites of therapeutic relevance.
    • Tuning proton behavior in a ternary molecular complex.

      Thomas, L.H.; Blagden, Nicholas; Gutmann, M.J.; Kallay, A.A.; Parkin, A.; Seaton, Colin C.; Wilson, C.C. (2010-06)
      The multicomponent ternary complex of 4-dimethylaminobenzoic acid (4-DABA), 3,5-dinitrobenzoic acid (3,5-DNBA), and 4,40-bipyridine (BIPY) has been studied by variable temperature X-ray and neutron diffraction. Proton disorder is observed within the 4-DABA homodimers present and quantitatively evaluated from neutron data. The effect of the crystal environment and in particular the pyramidalization of the nitrogen atom within the 4-DABA molecule and the consequential effect on the presence of hydrogen atom disorder are discussed with reference to the previously determined pure 4-DABA structure and the binary cocrystal with 3,5-DNBA.
    • Tuning the aggregation behavior of pH-responsive micelles by copolymerization

      Wright, D.B.; Patterson, J.P.; Pitto-Barry, Anaïs; Cotenda, P.; Chassenieux, C.; Colombani, O.; O'Reilly, R.K. (2015-04-14)
      Amphiphilic diblock copolymers, poly(2-(diethylamino)ethyl methacrylate-co-2-(dimethylamino)ethyl methacrylate)-b-poly(2-(dimethylamino)ethyl methacrylate), P(DEAEMA-co-DMAEMA)-b-PDMAEMA with various amounts of DEAEMA have been synthesized by RAFT polymerization. Their micellization in water has been investigated by scattering measurements over a wide pH range. It appeared that the polymers self-assembled into pH sensitive star like micelles. For a given composition, when the pH is varied the extent of aggregation can be tuned reversibly by orders of magnitude. By varying the copolymer composition in the hydrophobic block, the onset and extent of aggregation were shifted with respect to pH. This class of diblock copolymer offers the possibility to select the range of stimuli-responsiveness that is useful for a given application, which can rarely be achieved with conventional diblock copolymers consisting of homopolymeric blocks.
    • Two Heterometallic Ionic Compounds with Isolated [3d] and [4f] Complex Units: Field-Induced Single-Ion Magnet (SIM) Behavior Observed from a Mononuclear Dysprosium(III) Complex

      Nayak, Sanjit; Novitchi, G.; Holynska, M.; Dehnen, S. (2014-09)
      This article corrects http://onlinelibrary.wiley.com/enhanced/doi/10.1002/ejic.201402114. 2014(19): 3065-3071.