bluuebunny/crossref_metadata_2025_split huggingface dataset:
The chromatin remodeller RSF1 is essential for PLK1 deposition and function at mitotic kinetochores
Authors: Lee Ho-Soo , Park Yong-Yea , Cho Mi-Young , Chae Sunyoung , Yoo Young-Suk , Kwon Myung-Hee , Lee Chang-Woo , Cho Hyeseong 
Published: August 2015

AbstractAccumulation of PLK1 at kinetochores is essential for chromosome alignment and segregation; however, the mechanism underlying PLK1 recruitment to kinetochores remains unresolved. The chromatin remodeller RSF1 tightly associates with centromere proteins, but its mitotic function is unknown. Here we show that RSF1 localizes at mitotic kinetochores and directly binds PLK1. RSF1 depletion disrupts localization of PLK1 at kinetochores; the C-terminal fragment of RSF1, which can bind PLK1, is sufficient to restore PLK1 localization. Moreover, CDK1 phosphorylates RSF1 at Ser1375, and this phosphorylation is necessary for PLK1 recruitment. Subsequently, PLK1 phosphorylates RSF1 at Ser1359, stabilizing PLK1 deposition. Importantly, RSF1 depletion mimicks the chromosome misalignment phenotype resulting from PLK1 knockdown; these defects are rescued by RSF1 S1375D or RSF1 S1359D but not RSF1 S1375A, showing a functional link between phosphorylation of RSF1 and chromosome alignment. Together, these data show that RSF1 is an essential centromeric component that recruits PLK1 to kinetochores and plays a crucial role in faithful cell division.
Longer-term outcome in the prevention of psychotic disorders by the Vienna omega-3 study
Authors: Amminger G. Paul , Schäfer Miriam R. , Schlögelhofer Monika , Klier Claudia M. , McGorry Patrick D. 
Published: August 2015

AbstractLong-chain omega-3 polyunsaturated fatty acids (PUFAs) are essential for neural development and function. As key components of brain tissue, omega-3 PUFAs play critical roles in brain development and function, and a lack of these fatty acids has been implicated in a number of mental health conditions over the lifespan, including schizophrenia. We have previously shown that a 12-week intervention with omega-3 PUFAs reduced the risk of progression to psychotic disorder in young people with subthreshold psychotic states for a 12-month period compared with placebo. We have now completed a longer-term follow-up of this randomized, double-blind, placebo-controlled trial, at a median of 6.7 years. Here we show that brief intervention with omega-3 PUFAs reduced both the risk of progression to psychotic disorder and psychiatric morbidity in general in this study. The majority of the individuals from the omega-3 group did not show severe functional impairment and no longer experienced attenuated psychotic symptoms at follow-up.
Adiabatic far-field sub-diffraction imaging
Authors: Cang Hu , Salandrino Alessandro , Wang Yuan , Zhang Xiang 
Published: August 2015

AbstractThe limited resolution of a conventional optical imaging system stems from the fact that the fine feature information of an object is carried by evanescent waves, which exponentially decays in space and thus cannot reach the imaging plane. We introduce here an adiabatic lens, which utilizes a geometrically conformal surface to mediate the interference of slowly decompressed electromagnetic waves at far field to form images. The decompression is satisfying an adiabatic condition, and by bridging the gap between far field and near field, it allows far-field optical systems to project an image of the near-field features directly. Using these designs, we demonstrated the magnification can be up to 20 times and it is possible to achieve sub-50 nm imaging resolution in visible. Our approach provides a means to extend the domain of geometrical optics to a deep sub-wavelength scale.
Multifunctional luminescent nanomaterials from NaLa(MoO4)2:Eu3+/Tb3+ with tunable decay lifetimes, emission colors and enhanced cell viability
Authors: Yang Mei , Liang Youlong , Gui Qingyuan , Zhao Bingxin , Jin Dayong , Lin Mimi , Yan Lu , You Hongpeng , Dai Liming , Liu Yong 
Published: August 2015

AbstractA facile, but effective, method has been developed for large-scale preparation of NaLa(MoO4)2 nanorods and microflowers co-doped with Eu3+ and Tb3+ ions (abbreviated as: NLM:Ln3+). The as-synthesized nanomaterials possess a pure tetragonal phase with variable morphologies from shuttle-like nanorods to microflowers by controlling the reaction temperature and the amount of ethylene glycol used. Consequently, the resulting nanomaterials exhibit superb luminescent emissions over the visible region from red through yellow to green by simply changing the relative doping ratios of Eu3+ to Tb3+ ions. Biocompatibility study indicates that the addition of NLM:Ln3+ nanomaterials can stimulate the growth of normal human retinal pigment epithelium (ARPE-19) cells. Therefore, the newly-developed NaLa(MoO4)2 nanomaterials hold potentials for a wide range of multifunctional applications, including bioimaging, security protection, optical display, optoelectronics for information storage and cell stimulation.
Impaired coherence of life narratives of patients with schizophrenia
Authors: Allé Mélissa C. , Potheegadoo Jevita , Köber Christin , Schneider Priscille , Coutelle Romain , Habermas Tilmann , Danion Jean-Marie , Berna Fabrice 
Published: August 2015

AbstractSelf-narratives of patients have received increasing interest in schizophrenia since they offer unique material to study patients’ subjective experience related to their illness, in particular the alteration of self that accompanies schizophrenia. In this study, we investigated the life narratives and the ability to integrate and bind memories of personal events into a coherent narrative in 27 patients with schizophrenia and 26 controls. Four aspects of life narratives were analyzed: coherence with cultural concept of biography, temporal coherence, causal-motivational coherence and thematic coherence. Results showed that in patients cultural biographical knowledge is preserved, whereas temporal coherence is partially impaired. Furthermore, causal-motivational and thematic coherence are significantly impaired: patients have difficulties explaining how events have modeled their identity and integrating different events along thematic lines. Impairment of global causal-motivational and thematic coherence was significantly correlated with patients’ executive dysfunction, suggesting that cognitive impairment observed in patients could affect their ability to construct a coherent narrative of their life by binding important events to their self. This study provides new understanding of the cognitive deficits underlying self-disorders in patients with schizophrenia. Our findings suggest the potential usefulness of developing new therapeutic interventions to improve autobiographical reasoning skills.
High frequency of deficient consumption and low blood levels of 25-hydroxyvitamin D in HIV-1-infected adults from São Paulo city, Brazil
Authors: Sales Stephanie Hael , Matta Sandra Maria , Silva Daniela Cardeal da , Assone Tatiane , Fonseca Luiz Augusto M. , Duarte Alberto J. S. , Casseb Jorge 
Published: August 2015

AbstractMicronutrient deficiency is common in patients with HIV/AIDS, usually caused by mal-absorption and/or drug interactions. 25-hydroxyvitamin D is of fundamental importance for the homeostasis of musculoskeletal health. The current study aimed to evaluate the nutritional status of HIV-infected subjects in order to make their nutritional diagnoses, including their vitamin D blood levels and to estimate their consumption of vitamin D. The study included 98 HIV-1-infected subjects, followed at University of São Paulo Medical School - HC-FMUSP. We performed a nutritional evaluation, along with the determination of patients’ serum 25-hydroxyvitamin D and calcium concentration, biochemical analyses and an anthropometric assessment. In the medical interview a 24-hour food recall was used (R24) to estimate daily calorie intake, macronutrients, calcium and vitamin D. A high level of vitamin D deficiency was observed in our patients: 83.4% of them had levels below 30 ng/ml; they also presented an increased risk of cardiovascular disease, along with a high consumption of dietary fat. Factors related to the virus itself and to the use of antiretroviral drugs may have contributed for the low vitamin D levels seen in our HIV-1-infected patients.
Mitochondrial respiratory chain and thioredoxin reductase regulate intermembrane Cu,Zn-superoxide dismutase activity: implications for mitochondrial energy metabolism and apoptosis
Authors: Iñarrea Pedro , Moini Hadi , Han Derick , Rettori Daniel , Aguiló Ignacio , Alava Maria Angeles , Iturralde María , Cadenas Enrique 
Published: August 2015

IMS (intermembrane space) SOD1 (Cu/Zn-superoxide dismutase) is inactive in isolated intact rat liver mitochondria and is activated following oxidative modification of its critical thiol groups. The present study aimed to identify biochemical pathways implicated in the regulation of IMS SOD1 activity and to assess the impact of its functional state on key mitochondrial events. Exogenous H2O2 (5 μM) activated SOD1 in intact mitochondria. However, neither H2O2 alone nor H2O2 in the presence of mitochondrial peroxiredoxin III activated SOD1, which was purified from mitochondria and subsequently reduced by dithiothreitol to an inactive state. The reduced enzyme was activated following incubation with the superoxide generating system, xanthine and xanthine oxidase. In intact mitochondria, the extent and duration of SOD1 activation was inversely correlated with mitochondrial superoxide production. The presence of TxrR-1 (thioredoxin reductase-1) was demonstrated in the mitochondrial IMS by Western blotting. Inhibitors of TxrR-1, CDNB (1-chloro-2,4-dinitrobenzene) or auranofin, prolonged the duration of H2O2-induced SOD1 activity in intact mitochondria. TxrR-1 inactivated SOD1 purified from mitochondria in an active oxidized state. Activation of IMS SOD1 by exogenous H2O2 delayed CaCl2-induced loss of transmembrane potential, decreased cytochrome c release and markedly prevented superoxide-induced loss of aconitase activity in intact mitochondria respiring at state-3. These findings suggest that H2O2, superoxide and TxrR-1 regulate IMS SOD1 activity reversibly, and that the active enzyme is implicated in protecting vital mitochondrial functions.
Induction of fatty acid synthase and S14 gene expression by glucose, xylitol and dihydroxyacetone in cultured rat hepatocytes is closely correlated with glucose 6-phosphate concentrations
Authors: MOURRIERAS Florence , FOUFELLE Fabienne , FORETZ Marc , MORIN Joëlle , BOUCHE Sandrine , FERRE Pascal 
Published: August 2015

It is now well established that the transcription of several genes belonging to the glycolytic and lipogenic pathway is stimulated in the presence of a high glucose concentration in adipocytes and hepatocytes. We have previously proposed that glucose 6-phosphate could be the signal metabolite that transduces the glucose effect. This proposal has recently been challenged and both an intermediate of the pentose phosphate pathway, xylulose 5-phosphate, and metabolites of the later part of glycolysis (3-phosphoglycerate and phosphoenolpyruvate) have been proposed. To discriminate between these possibilities, we have measured concomitantly, in primary cultures of adult rat hepatocytes, the expression of the fatty acid synthase (FAS) and S14 genes and the concentration of glucose metabolites. We have used various substrates entering at different steps of the glycolytic pathway (glucose, dihydroxyacetone) and the pentose phosphate pathway (xylitol). When compared with 5 mM glucose, 25 mM glucose induces a marked increase in both S14 and FAS gene expression, detectable as early as 2 h and peaking at 6 h. Increasing concentrations (1–5 mM) of xylitol and dihydroxyacetone in the presence of 5 mM glucose are also able to induce S14 and FAS gene expression progressively. Among the various glucose metabolites measured, glucose 6-phosphate, in contrast with xylulose 5-phosphate and metabolites of the lower part of glycolysis, is the only one that shows a clear-cut parallelism between its concentration and the degree of S14 and FAS gene expression. We conclude that glucose 6-phosphate is the most likely signal metabolite for the glucose-induced transcription of this group of genes.
Chicken vigilin gene: a distinctive pattern of hypersensitive sites is characteristic for its transcriptional activity
Authors: GRÜNWELLER Arnold , PURSCHKE Werner G. , KÜGLER Sebastian , KRUSE Charli , MÜLLER Peter K. 
Published: August 2015

Vigilin, a multidomain hn-ribonucleo-K-homologous protein, is part of a ribonucleoprotein complex with cognate tRNA and is found in both the nucleus and the cytoplasm. In an approach to identify genomic regions involved in regulation of the chicken vigilin gene, we carried out transfection studies with a reporter gene in suitable chicken cells. After including a distantly positioned 5′-sequence in the construct, we observed a 10.5-fold increase in luciferase (EC 1.13.12.7) expression compared with basal promoter activity. Accordingly, chromatin analysis of freshly isolated embryonic tendon fibroblasts with high levels of vigilin mRNA expression shows a DNase-I-hypersensitive site (DHS1) localized 2.2 kb upstream of the transcriptional start site. Similarly, phytohaemagglutinin-stimulated lymphocytes with a 4-fold elevated expression of vigilin mRNA compared with resting lymphocytes also exhibited this unique DHS, having switched from that found at 3.3 kb (DHS2) in resting lymphocytes. Furthermore, using gel-retardation experiments with DNA representing either DHS1 or DHS2, a specific interaction with chicken nuclear extracts was seen.
Role of ATP and Pi in the mechanism of insulin secretion in the mouse insulinoma βTC3 cell line
Authors: PAPAS Klearchos K. , LONG Robert C. , CONSTANTINIDIS Ioannis , SAMBANIS Athanassios 
Published: August 2015

Understanding the biochemical events associated with glucose-stimulated insulin secretion by pancreatic β cells is of importance in gaining insight into both the pathophysiology of diabetes and the development of tissue-engineered bioartificial pancreatic substitutes. We have investigated the effects of glucose concentration on the bioenergetic status and on the metabolic and secretory functions exhibited by mouse insulinoma βTC3 cells entrapped in calcium alginate/poly-L-lysine/alginate (APA) beads. Cells entrapped in APA beads constitute a possible implantable bioartificial pancreas for the long-term treatment of insulin-dependent diabetes mellitus. Our results show that, in entrapped βTC3 cells, the oxygen consumption rate and the intracellular nucleotide triphosphate levels are unaffected by a step change in glucose concentration from 16 mM to 0 mM for 4.5 h and then back to 16 mM. The intracellular Pi level and the ammonia production rate were doubled, while insulin secretion was decreased 10-fold, upon switching from 16 mM to 0 mM glucose. The implications of these findings in the context of pancreatic β cell biochemistry and the mechanism of the ‘Fuel Hypothesis’ are discussed.
Oxidation of high-density lipoprotein HDL3 leads to exposure of apo-AI and apo-AII epitopes and to formation of aldehyde protein adducts, and influences binding of oxidized low-density lipoprotein to type I and type III collagen in vitro
Authors: GREILBERGER Joachim , JÜRGENS Günther 
Published: August 2015

The changes in the immunological properties of apolipoprotein AI (apo-AI) and AII (apo-AII) during the oxidation of the high-density lipoprotein HDL3 and its influence on the binding of heavily oxidized low-density lipoprotein (LDL) to type I and III collagen were investigated. Oxidation of HDL3 or Eu3+-labelled HDL3 was performed with CuSO4, varying the time of oxidation. Oxidation of HDL3 resulted in an increase in lipid hydroperoxides and enhanced the negative charge of this lipoprotein. Immunological studies with a solid-phase sandwich immunoassay revealed a strong increase in binding of Eu3+-labelled HDL3 to polyclonal antibodies against apo-AI and apo-AII within the first 4 h of oxidation. Neo-epitopes were also formed by interaction of the apolipoproteins with degradation products from the lipid peroxidation of polyunsaturated fatty acids, as evidenced by an immunoreaction of oxidized Eu3+-labelled HDL3 with antibodies to 4-hydroxynonenal (4-HNE)– and malondialdehyde (MDA)–protein adducts. Western blot analysis of oxidized HDL3 samples showed, as well as apo-AI and apo-AII bands, larger aggregated apolipoproteins, occurring after 0.5–2.5 h of oxidation. These aggregates were recognized by antibodies to apo-AI and apo-AII as well as by antibodies to 4-HNE- and MDA-protein adducts. Furthermore the original apo-AI monomers and apo-AII dimers decreased during the oxidation. The ability of native and oxidized HDL3 to prevent the binding of Eu3+-labelled 24 h-oxidized LDL to collagen on microtitration plates was estimated. Interestingly, 2 h-oxidized HDL3 competed most with the binding of 24 h-oxidized LDL on collagen type I and type III, followed by native HDL3. However, 24 h-oxidized HDL3 was a weaker competitor. Thus oxidative modification of HDL3 strongly alters the immunological properties of this lipoprotein and its binding affinity for collagen.
The reaction of halides with pulsed cytochrome bo from Escherichia coli
Authors: MOODY A. John , BUTLER Clive S. , WATMOUGH Nicholas J. , THOMSON Andrew J. , RICH Peter R. 
Published: August 2015

Cytochrome bo forms complexes with chloride, bromide and iodide in which haem o remains high-spin and in which the ‘630 nm ’ charge-transfer band is red-shifted by 7–8 nm. The chloride and bromide complexes each have a characteristic set of integer-spin EPR signals arising from spin coupling between haem o and CuB. The rate and extent of chloride binding decreases as the pH increases from 5.5 to 8.5. At pH 5.5 the dissociation constant for chloride is 2 mM and the first-order rate constant for dissociation is 2×10-4 s-1. The order of rate of binding, and of affinity, at pH 5.5 is chloride (1) &gt; bromide (0.3) &gt; iodide (0.1). It is suggested that the halides bind in the binuclear site but, unlike fluoride, they are not direct ligands of the iron of haem o. In addition, both the stability of the halide complexes and the rate of halide binding seem to be increased by the co-binding of a proton.
The negative charge of glutamic acid-820 in the gastric H+,K+-ATPase α-subunit is essential for K+ activation of the enzyme activity
Authors: HERMSEN Harm P. H. , SWARTS Herman G. P. , KOENDERINK Jan B. , De PONT Jan Joep H. H. M. 
Published: August 2015

To investigate the role of Glu820, located in transmembrane domain M6 of the α-subunit of gastric H+,K+-ATPase, a number of mutants was prepared and expressed in Sf9 cells using a baculovirus encoding for both H+,K+-ATPase subunits. The wild-type enzyme and the E820D (Glu820 → Asp) mutant showed a similar biphasic activation by K+ on the ATPase activity (maximum at 1 mM). The mutant E820A had a markedly decreased K+ affinity (maximum at 40–100 mM). The other mutants, E820Q, E820N, E820L and E820K, showed no K+-activated ATPase activity at all, whereas all mutants formed a phosphorylated intermediate. After preincubation with K+ before phosphorylation mutant E820D showed a similar K+-sensitivity as the wild-type enzyme. The mutants E820N and E820Q had a 10–20 times lower sensitivity, whereas the other three mutants were hardly sensitive towards K+. Upon preincubation with 3-(cyanomethyl)-2-methyl-8-(phenylmethoxy)imidazo[1,2a] pyridine (SCH 28080), all mutants showed similar sensitivity for this drug as the wild-type enzyme, except mutant E820Q, which could only partly be inhibited, and mutant E820K, which was completely insensitive towards SCH 28080. These experiments suggest that, with a relatively large residue at position 820, the binding of SCH 28080 is obstructed. The various mutants showed a behaviour in K+-stimulated-dephosphorylation experiments similar to that for K+-activated-ATPase-activity measurements. These results indicate that K+ binding, and indirectly the transition to the E2 form, is only fully possible when a negatively charged residue is present at position 820 in the α-subunit.
Iron loading of isolated rat hepatocytes inhibits asialoglycoprotein receptor dynamics and induces formation of rat hepatic leptin-1 (RHL-1) oligomers
Authors: McABEE Douglas D. , LING Yuan Yuan , STICH Charles 
Published: August 2015

The major subunit [rat hepatic lectin-1 (RHL-1)] of the asialoglycoprotein (ASGP) receptor mediates endocytosis of the iron-binding protein lactoferrin (Lf) by isolated rat hepatocytes, yet iron loading of cultured adult rat hepatocytes increases the binding and endocytosis of Lf while greatly inhibiting the uptake of desialylated ligand. In the present study, we determined whether the iron-induced Lf-binding site is RHL-1 and examined the nature of the iron-induced block in ASGP receptor endocytic function. Isolated rat hepatocytes increased their non-haem iron content from 70 to 470 p.p.b. following incubation with ferric ammonium citrate (⩽ 100 µg/ml). These conditions blocked internalization of 125I-asialo-orosomucoid (ASOR) by ≈ 90% but increased 125I-Lf endocytosis by 40%. ASOR and anti-RHL-1 sera blocked the binding and endocytosis of 125I-Lf on control cells but not on iron-loaded cells, indicating that the iron-induced Lf-binding site on hepatocytes is not RHL-1. Iron-loading of hepatocytes in the presence or absence of excess ASOR did not significantly alter the number of active ASGP receptors on the cell surface. In contrast, iron-loading decreased the number of active intracellular receptors by 40% and blocked the uptake of 125I-ASOR prebound to the cells by ≈ 80%. Under these conditions, we found an iron-dependent evolution of 88 and 140 kDa RHL-1-containing, β-mercaptoethanol-sensitive multimers that constituted up to 34 and 23%, respectively, of total immunodetectable RHL-1. We propose that iron-induced formation of cystinyl-linked RHL-1-containing multimers inhibits ASGP receptor movement between cell surface and interior and disrupts acylation of intracellular receptors.
Thiol-independent interaction of protein disulphide isomerase with type X collagen during intra-cellular folding and assembly
Authors: McLAUGHLIN Stephen H. , BULLEID Neil J. 
Published: August 2015

Protein disulphide isomerase (PDI) has been shown to be a multifunctional protein capable of catalysing disulphide-bond formation and isomerization, and of participating as a non-catalytic subunit of prolyl 4-hydroxylase (P4-H) and microsomal triacylglycerol transfer protein. It has also been proposed to function as a molecular chaperone during the refolding of denatured proteins in vitro. To investigate its potential role as a molecular chaperone within a cellular context, we studied the folding, modification and assembly of type X collagen in semi-permeabilized cells. Using this approach, we demonstrate that depletion of ATP has no effect on the rate or extent of helix formation, indicating that the individual triple helical regions do not interact with the molecular chaperone immunoglobulin heavy-chain binding protein (BiP). However, PDI was shown to interact transiently with type X during helix formation in a role related to its function as the β subunit of P4-H. Once the collagen triple helix was formed, PDI re-associated, indicating a role in preventing the premature assembly of this molecule into higher-order structures. This interaction was not thiol dependent, as a type X polypeptide that did not contain any cysteine residues was able to fold correctly and interact with PDI. Both PDI and the collagen-binding protein hsp47 showed a similar pH-dependent interaction with folded collagen, dissociating when the pH was lowered to pH 6.0. These results suggest a role for PDI in chaperoning type X collagen during its transport through the cell.