FAD binding overcomes defects in activity and stability displayed by cancer-associated variants of human NQO1

NAD(P)H quinone oxidoreductase 1 is involved in antioxidant defence and protection from cancer, stabilizing the apoptosis regulator p53 towards degradation. Here, we studied the enzymological, biochemical and biophysical properties of two cancer-associated variants (p.R139W and p.P187S). Both variants (especially p.187S) have lower thermal stability and greater susceptibility to proteolysis compared to the wild-type. p.P187S also has reduced activity due to a lower binding affinity for the FAD cofactor as assessed by activity measurements and direct titrations. Native gel electrophoresis and dynamic light scattering also suggest that p.P187S has a higher tendency to populate unfolded states under native conditions. Detailed thermal stability studies showed that all variants irreversibly denature causing dimer dissociation, while addition of FAD restores the stability of the polymorphic forms to wild-type levels. The kinetic destabilization induced by polymorphisms as well as the kinetic protection exerted by FAD was confirmed by measuring denaturation kinetics at temperatures close to physiological. Our data suggest that the main molecular mechanisms associated with these cancer-related variants are their low binding affinity for FAD and/or kinetic instability. Thus, pharmacological chaperones may be useful in the treatment of patients bearing these polymorphisms.

The metastability of human UDP-galactose 4'-epimerase (GALE) is increased by variants associated with type III galactosemia but decreased by substrate and cofactor binding

Type III galactosemia is an inherited disease caused by mutations which affect the activity of UDP-galactose 4'-epimerase (GALE). We evaluated the impact of four disease-associated variants (p.N34S, p.G90E, p.V94M and p.K161N) on the conformational stability and dynamics of GALE. Thermal denaturation studies showed that wild-type GALE denatures at temperatures close to physiological, and disease-associated mutations often reduce GALE's thermal stability. This denaturation is under kinetic control and results partly from dimer dissociation. The natural ligands, NAD(+) and UDP-glucose, stabilize GALE. Proteolysis studies showed that the natural ligands and disease-associated variations affect local dynamics in the N-terminal region of GALE. Proteolysis kinetics followed a two-step irreversible model in which the intact protein is cleaved at Ala38 forming a long-lived intermediate in the first step. NAD(+) reduces the rate of the first step, increasing the amount of undigested protein whereas UDP-glucose reduces the rate of the second step, increasing accumulation of the intermediate. Disease-associated variants affect these rates and the amounts of protein in each state. Our results also suggest communication between domains in GALE. We hypothesize that, in vivo, concentrations of natural ligands modulate GALE stability and that it should be possible to discover compounds which mimic the stabilising effects of the natural ligands overcoming mutation-induced destabilization.

Efficient tracking of human poses using a manifold hierarchy

In this paper a 3D human pose tracking framework is presented. A new dimensionality reduction method (Hierarchical Temporal Laplacian Eigenmaps) is introduced to represent activities in hierarchies of low dimensional spaces. Such a hierarchy provides increasing independence between limbs, allowing higher flexibility and adaptability that result in improved accuracy. Moreover, a novel deterministic optimisation method (Hierarchical Manifold Search) is applied to estimate efficiently the position of the corresponding body parts. Finally, evaluation on public datasets such as HumanEva demonstrates that our approach achieves a 62.5mm-65mm average joint error for the walking activity and outperforms state-of-the-art methods in terms of accuracy and computational cost.

The Development of the Contextual Analysis of Human Remains in Ireland

The colonial experience has been a dominant factor in the production of culture in Ireland, including narratives of the past. In the context of nineteenth century British imperialism, physical anthropology and archaeology were just two of a number of scientific discourses recruited to rationalise and justify colonialist policies. Legitimation was in part provided by racialised and sectarian conceptualisations of local populations in both past and present. After the partition of the island in the early twentieth century, racialised notions of the Irish population were embraced by both nationalist movements (green and orange) on the island. Changes came with the impact of processual archaeology and the appearance of bioarchaeology in the early 1980s, the latter directly influenced by the North American tradition. The last two decades have seen considerable achievements in bioarchaeology in Ireland. The profile of the discipline has been raised, and despite the impact of the recent economic downturn, the number of archaeologists gaining the necessary specialist skills has finally reached critical mass. The focus in Irish bioarchaeology is now on synthetic and thematic projects, and a number of initiatives are currently underway which will go some way towards furthering understanding of the past populations of Ireland.

Differentiation of human pluripotent stem cells to cells similar to cord-blood endothelial colony-forming cells

The ability to differentiate human pluripotent stem cells into endothelial cells with properties of cord-blood endothelial colony–forming cells (CB-ECFCs) may enable the derivation of clinically relevant numbers of highly proliferative blood vessel–forming cells to restore endothelial function in patients with vascular disease. We describe a protocol to convert human induced pluripotent stem cells (hiPSCs) or embryonic stem cells (hESCs) into cells similar to CB-ECFCs at an efficiency of >10⁸ ECFCs produced from each starting pluripotent stem cell. The CB-ECFC-like cells display a stable endothelial phenotype with high clonal proliferative potential and the capacity to form human vessels in mice and to repair the ischemic mouse retina and limb, and they lack teratoma formation potential. We identify Neuropilin-1 (NRP-1)-mediated activation of KDR signaling through VEGF₁₆₅ as a critical mechanism for the emergence and maintenance of CB-ECFC-like cells.

The European Court of Human Rights and Domestic Violence: Valiuliene v Lithuania

This article analyses the recent jurisprudence of the European Court of Human Rights on the issue of domestic violence, with a particular focus on Valiuliene v Lithuania. It seems that to date the Court’s jurisprudence on this issue is somewhat inconsistent, and with Valiuliene v Lithuania the Court was given an opportunity to clarify its approach in this area. There are certainly a number of positive aspects to the Court’s judgment, however there are also difficulties with the approach of the Court in this case. Overall it is to be hoped that the judgment in Valiuliene v Lithuania will mark the beginning of a more coherent jurisprudence as regards domestic violence.

Contractile properties of human renal cell carcinoma recruited arteries and their response to nicotinamide

Background and purpose: The manipulation of tumour blood supply and thus oxygenation is a potentially important strategy for improving the treatment of solid tumours by radiation. Increased knowledge about the characteristics that distinguish the tumour vasculature from its normal counterparts may enable tumour blood flow to be more selectively modified, Nicotinamide (NA) causes relaxation of preconstricted normal and tumour-supply arteries in rats. It has also been shown to affect microregional blood flow in human tumours. Direct effects of NA on human tumour supply arteries have not previously been reported. This paper describes our evaluation of the effects of NA on two parameters: 'spontaneous', oscillatory contractile activity and agonist (phenylephrine)-induced constriction in the arteries supplying human renal cell carcinomas.

Materials and methods: Isolated renal cell carcinoma feeder vessels were perfused in an organ bath with the alpha(1)-adrenoceptor agonist phenylephrine (PE). When the arteries had reached a plateau of constriction, nicotinamide (8.2 mM) was added to the perfusate and changes in perfusion pressure were measured.

Results: PE (10 mu M) induced a sustained constriction in the majority of the renal cell carcinoma feeder vessels examined, demonstrating that they retain contractile characteristics, at least in response to this alpha(1)-adrenoceptor agonist. In combination with NA (8.2 mM) the constriction was significantly attenuated in half of the preparations. In addition, seven arteries exhibited spontaneous contractile activity which was significantly attenuated by NA in six of them.

Conclusions: NA can significantly attenuate both 'spontaneous' and agonist-induced constrictions in tumour-recruited human arteries, though not all arteries are sensitive. Published by Elsevier Science Ireland Ltd.

The EU Charter of Fundamental Rights in the case law of the European Court of Human Rights

The European Court of Human Rights has begun to refer to the EU Charter of Fundamental Rights in order to support its reasoning for interpreting the European Convention on Human Rights in a particular way. But the EU Charter does not yet have any special status in that regard, being treated by the Court as on a par with numerous other documents of international law. The Court’s use of the Charter began in connection with arts 8 and 12 of the Convention (the right to a family life and the right to marry) but in subsequent years it has been extended to many other Articles of the Convention. It is in relation to art.6 (the right to a fair trial) that the Charter’s influence has been most noticeable so far, the Court having changed its position on two important aspects of Article 6 partly because of the wording of the EU Charter. But the influence on art.3 (in relation to the rights of asylum seekers), art.7 (in relation to retroactive penal laws), art.9 (in relation to the right to conscientious objection) and art.11 (in relation to rights of trades unions) has also been significant. The potential for the Charter to have greater influence on the Court’s jurisprudence in years to come remains considerable.

DEAD-box helicase DP103 defines metastatic potential of human breast cancers

Despite advancement in breast cancer treatment, 30% of patients with early breast cancers experience relapse with distant metastasis. It is a challenge to identify patients at risk for relapse; therefore, the identification of markers and therapeutic targets for metastatic breast cancers is imperative. Here, we identified DP103 as a biomarker and metastasis-driving oncogene in human breast cancers and determined that DP103 elevates matrix metallopeptidase 9 (MMP9) levels, which are associated with metastasis and invasion through activation of NF-κB. In turn, NF-κB signaling positively activated DP103 expression. Furthermore, DP103 enhanced TGF-β-activated kinase-1 (TAK1) phosphorylation of NF-κB-activating IκB kinase 2 (IKK2), leading to increased NF-κB activity. Reduction of DP103 expression in invasive breast cancer cells reduced phosphorylation of IKK2, abrogated NF-κB-mediated MMP9 expression, and impeded metastasis in a murine xenograft model. In breast cancer patient tissues, elevated levels of DP103 correlated with enhanced MMP9, reduced overall survival, and reduced survival after relapse. Together, these data indicate that a positive DP103/NF-κB feedback loop promotes constitutive NF-κB activation in invasive breast cancers and activation of this pathway is linked to cancer progression and the acquisition of chemotherapy resistance. Furthermore, our results suggest that DP103 has potential as a therapeutic target for breast cancer treatment.

Metabolic signatures of human Alzheimer's disease (AD): H-1 NMR analysis of the polar metabolome of post-mortem brain tissue

Brain tissue from so-called Alzheimer's disease (AD) mouse models has previously been examined using H-1 NMR-metabolomics, but comparable information concerning human AD is negligible. Since no animal model recapitulates all the features of human AD we undertook the first H-1 NMR-metabolomics investigation of human AD brain tissue. Human post-mortem tissue from 15 AD subjects and 15 age-matched controls was prepared for analysis through a series of lyophilised, milling, extraction and randomisation steps and samples were analysed using H-1 NMR. Using partial least squares discriminant analysis, a model was built using data obtained from brain extracts. Analysis of brain extracts led to the elucidation of 24 metabolites. Significant elevations in brain alanine (15.4 %) and taurine (18.9 %) were observed in AD patients (p ≤ 0.05). Pathway topology analysis implicated either dysregulation of taurine and hypotaurine metabolism or alanine, aspartate and glutamate metabolism. Furthermore, screening of metabolites for AD biomarkers demonstrated that individual metabolites weakly discriminated cases of AD [receiver operating characteristic (ROC) AUC <0.67; p < 0.05]. However, paired metabolites ratios (e.g. alanine/carnitine) were more powerful discriminating tools (ROC AUC = 0.76; p < 0.01). This study further demonstrates the potential of metabolomics for elucidating the underlying biochemistry and to help identify AD in patients attending the memory clinic

Untargeted Metabolomic Analysis of Human Plasma Indicates Differentially Affected Polyamine and L-Arginine Metabolism in Mild Cognitive Impairment Subjects Converting to Alzheimer’s Disease

This study combined high resolution mass spectrometry (HRMS), advanced chemometrics and pathway enrichment analysis to analyse the blood metabolome of patients attending the memory clinic: cases of mild cognitive impairment (MCI; n = 16), cases of MCI who upon subsequent follow-up developed Alzheimer's disease (MCI_AD; n = 19), and healthy age-matched controls (Ctrl; n = 37). Plasma was extracted in acetonitrile and applied to an Acquity UPLC HILIC (1.7μm x 2.1 x 100 mm) column coupled to a Xevo G2 QTof mass spectrometer using a previously optimised method. Data comprising 6751 spectral features were used to build an OPLS-DA statistical model capable of accurately distinguishing Ctrl, MCI and MCI_AD. The model accurately distinguished (R2 = 99.1%; Q2 = 97%) those MCI patients who later went on to develop AD. S-plots were used to shortlist ions of interest which were responsible for explaining the maximum amount of variation between patient groups. Metabolite database searching and pathway enrichment analysis indicated disturbances in 22 biochemical pathways, and excitingly it discovered two interlinked areas of metabolism (polyamine metabolism and L-Arginine metabolism) were differentially disrupted in this well-defined clinical cohort. The optimised untargeted HRMS methods described herein not only demonstrate that it is possible to distinguish these pathologies in human blood but also that MCI patients 'at risk' from AD could be predicted up to 2 years earlier than conventional clinical diagnosis. Blood-based metabolite profiling of plasma from memory clinic patients is a novel and feasible approach in improving MCI and AD diagnosis and, refining clinical trials through better patient stratification.