bluuebunny/crossref_metadata_2025_split huggingface dataset:
Self-association and domain rearrangements between complement C3 and C3u provide insight into the activation mechanism of C3
Authors: Li Keying , Gor Jayesh , Perkins Stephen J. 
Published: August 2010

Component C3 is the central protein of the complement system. During complement activation, the thioester group in C3 is slowly hydrolysed to form C3u, then the presence of C3u enables the rapid conversion of C3 into functionally active C3b. C3u shows functional similarities to C3b. To clarify this mechanism, the self-association properties and solution structures of C3 and C3u were determined using analytical ultracentrifugation and X-ray scattering. Sedimentation coefficients identified two different dimerization events in both proteins. A fast dimerization was observed in 50 mM NaCl but not in 137 mM NaCl. Low amounts of a slow dimerization was observed for C3u and C3 in both buffers. The X-ray radius of gyration RG values were unchanged for both C3 and C3u in 137 mM NaCl, but depend on concentration in 50 mM NaCl. The C3 crystal structure gave good X-ray fits for C3 in 137 mM NaCl. By randomization of the TED (thioester-containing domain)/CUB (for complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domains in the C3b crystal structure, X-ray fits showed that the TED/CUB domains in C3u are extended and differ from the more compact arrangement of C3b. This TED/CUB conformation is intermediate between those of C3 and C3b. The greater exposure of the TED domain in C3u (which possesses the hydrolysed reactive thioester) accounts for the greater self-association of C3u in low-salt conditions. This conformational variability of the TED/CUB domains would facilitate their interactions with a broad range of antigenic surfaces. The second dimerization of C3 and C3u may correspond to a dimer observed in one of the crystal structures of C3b.
Musashi 1‐positive cells derived from mouse embryonic stem cells can differentiate into neural and intestinal epithelial‐like cells in vivo
Authors: Lan Shao‐Yang , Yu Tao , Xia Zhong‐Sheng , Yuan Yu‐Hong , Shi Liu , Lin Ying , Huang Kai‐Hong , Chen Qi‐Kui 
Published: August 2010

AbstractMsi1 (Musashi 1) is regarded as a marker for neural and intestinal epithelial stem cells. However, it is still unclear whether Msi1‐positive cells derived from mouse embryonic stem cells have the ability to differentiate into neural or intestinal epithelial cells. A pMsi1–GFP (green fluorescent protein) reporter plasmid was constructed in order to sort Msi1‐positive cells out of the differentiated cell population. The GFP‐positive cells (i.e. Msi1‐positive cells) were sorted by FACS and were hypodermically engrafted into the backs of NOD/SCID (non‐obese diabetic/severe combined immunodeficient) mice. The presence of neural and intestinal epithelial cells in the grafts was detected. Msi1 was highly expressed in the GFP‐positive cells, but not in the GFP‐negative cells. The markers for neural cells (Nestin and Tubulin β III) and intestinal epithelial cells [FABP2 (fatty acid binding protein 2), Lyz (lysozyme) and ChA (chromogranin A)] were more highly expressed in the grafts from Msi1‐positive cells than those from Msi1‐negative cells (P<0.05). The grafts from the Msi1‐negative cells contained more mesodermal‐like tissues than those from the Msi1‐positive cells. The pMsi1–GFP vector can be used to sort Msi1‐positive cells from a cell population derived from mouse embryonic stem cells. The Msi1‐positive cells can differentiate into neural and intestinal epithelial‐like cells in vivo.
Preparation of Very-High-Yield Recombinant Proteins Using Novel High-Cell-Density Bacterial Expression Methods
Authors: Murray Victoria , Chen Jianglei , Huang Yuefei , Li Qianqian , Wang Jianjun 
Published: August 2010

INTRODUCTIONUsing bacterial hosts such as Escherichia coli to produce recombinant proteins is a common practice in many laboratories. Here, we describe a protocol for preparing very-high-yield recombinant proteins using novel high-cell-density bacterial expression methods. By combining strictly regulated traditional isopropyl-β-D-thiogalactopyranoside (IPTG) induction with high-cell-density auto-induction, we have developed an efficient bacterial expression method that can be used widely and does not require changing expression vectors or fermentation. Beginning with a newly created bacterial expression vector, we outline the specific steps to determine whether the vector expresses the target protein, select high-expression colonies of the target protein, and optimize expression conditions for very-high-yield protein production. This method routinely produces 15-35 mg of pure protein from 50-mL bacterial cell cultures.
High-Throughput Microscopy Using Live Mammalian Cells
Authors: Terjung Stefan , Walter Thomas , Seitz Arne , Neumann Beate , Pepperkok Rainer , Ellenberg Jan 
Published: August 2010

INTRODUCTIONSince the complete sequencing of several genomes, the systematic understanding of protein function and interaction has become one of the most important tasks in current molecular biology. Recent advances in light microscopy equipment regarding automation and acquisition speed offer the possibility to perform hundreds of experiments in parallel to study protein function and interaction in intact cells. In this context, live cell imaging is an excellent tool that may be used to investigate dynamic or rarely occurring cellular processes, to distinguish between primary and secondary phenotypes, and to study the phenotype kinetics. In this article, we present a guideline for high-throughput microscopy for functional screening in living cells. We shall examine each aspect of the general screening process and consider specific examples in the processing of time-lapse experiments. Although this article is largely based on examples from cultured mammalian cells, many of its considerations apply to cultured cells from other species such as Drosophila and to some extent to microscopy-based screening in small organisms such as Caenorhabditis elegans.
Obtusilactone A and (−)‐sesamin induce apoptosis in human lung cancer cells by inhibiting mitochondrial Lon protease and activating DNA damage checkpoints
Authors: Wang Hui‐Min , Cheng Kuo‐Chen , Lin Cheng‐Jung , Hsu Shu‐Wei , Fang Wei‐Cheng , Hsu Tai‐Feng , Chiu Chien‐Chih , Chang Hsueh‐Wei , Hsu Chun‐Hua , Lee Alan Yueh‐Luen 
Published: August 2010

Several compounds from Cinnamomum kotoense show anticancer activities. However, the detailed mechanisms of most compounds from C. kotoense remain unknown. In this study, we investigated the anticancer activity of obtusilactone A (OA) and (−)‐sesamin in lung cancer. Our results show that human Lon is upregulated in non‐small‐cell lung cancer (NSCLC) cell lines, and downregulation of Lon triggers caspase‐3 mediated apoptosis. Through enzyme‐based screening, we identified two small‐molecule compounds, obtusilactone A (OA) and (−)‐sesamin from C. kotoense, as potent Lon protease inhibitors. Obtusilactone A and (−)‐sesamin interact with Ser855 and Lys898 residues in the active site of the Lon protease according to molecular docking analysis. Thus, we suggest that cancer cytotoxicity of the compounds is partly due to the inhibitory effects on Lon protease. In addition, the compounds are able to cause DNA double‐strand breaks and activate checkpoints. Treatment with OA and (−)‐sesamin induced p53‐independent DNA damage responses in NSCLC cells, including G1/S checkpoint activation and apoptosis, as evidenced by phosphorylation of checkpoint proteins (H2AX, Nbs1, and Chk2), caspase‐3 cleavage, and sub‐G1 accumulation. In conclusion, OA and (−)‐sesamin act as both inhibitors of human mitochondrial Lon protease and DNA damage agents to activate the DNA damage checkpoints as well induce apoptosis in NSCLC cells. These dual functions open a bright avenue to develop more selective chemotherapy agents to overcome chemoresistance and sensitize cancer cells to other chemotherapeutics. (Cancer Sci 2010; 101: 2612–2620)
Mite allergen induces nitric oxide production in alveolar macrophage cell lines via CD14/toll‐like receptor 4, and is inhibited by surfactant protein D
Authors: Liu C.‐F. , Chen Y.‐L. , Chang W.‐T. , Shieh C.‐C. , Yu C.‐K. , Reid K. B. M. , Wang J.‐Y. 
Published: August 2010

SummaryBackground
Previously, we have found that dust mite allergens can directly activate alveolar macrophages (AMs), induce inflammatory cytokines, and enhance T‐helper type 2 cytokine production. A molecule of innate immunity in the lung, surfactant protein D (SP‐D), is able to bind mite allergens and alleviates allergen‐induced airway inflammation.Objectives
This study was aimed at investigating the activation pathway of mite allergen (Dermatophagoides pteronyassinus, Der p)‐induced nitric oxide (NO) production by AMs, and the role of SP‐D in the modulation of activated AMs by mite allergens.Methods
Porcine SP‐D was purified from bronchoalveolar lavage fluids of Lan‐Yu mini‐pigs, by affinity chromatography on maltose‐sepharose. NO production, inducible expression of lipopolysaccharides (LPS)‐related binding and responding surface receptors complex, CD14 and toll‐like receptor 4 (TLR4), as well as inducible NO synthase (iNOs) and nuclear factor‐κB activation were studied in two AMs cell lines, MH‐S (BALB/c strain),and AMJ2‐C11 (C57BL/6 strain), and one peritoneal macrophage cell line (RAW264.7), after stimulation with LPS, or Der p.Results
LPS and Der p elicited different responses of NO production in the different cell lines, and the response might depend upon the expression of the cell surface CD14/TLR4 complex in different genetic backgrounds of macrophage cell lines. Pretreatment of macrophages with SP‐D could inhibit NO production from Der p or LPS‐stimulated alveolar macrophages.Conclusion
Mite allergen‐induced alveolar macrophage activation is mediated by CD14/TLR4 receptors and can be inhibited by SP‐D; it further supports the concept that SP‐D may be an important modulator of allergen‐induced pulmonary inflammation.
High titre of anti‐Ascaris immunoglobulin E associated with bronchial asthma symptoms in 5‐year‐old rural Bangladeshi children
Authors: Takeuchi H. , Zaman K. , Takahashi J. , Yunus M. , Chowdhury H. R. , Arifeen S. El , Baqui A. , Wakai S. , Iwata T. 
Published: August 2010

SummaryBackground
Increasing interest has arisen whether helminthic infections protect against asthma and allergy. The prevalence of wheezing among Bangladeshi children is higher in rural areas where helminthic infectious burden is greater, which is contrary to the general assumption.Objective
We therefore examined the association between Ascaris infection, serum level of anti‐Ascaris IgE, which should be investigated differently from the infection, and wheezing in 5‐year‐old children from rural Bangladesh.Methods
A total of 219 children who reported wheezing during the previous 12 months and 122 randomly selected age‐matched individuals who had never experienced wheezing were tested for serum levels of total and specific Ascaris, Dermatophagoides pteronyssinus, alternaria and cockroach IgEs, and for intestinal helminth infection as well.Results
Anti‐Ascaris IgE levels were significantly and independently associated with current wheezing during the previous 12 months [odds ratio (OR) per loge increment is 1.31 (95% confidence interval (CI) 1.08–1.60), P=0.007], a history of at least four episodes of wheezing [OR per loge increment is 1.52 (95% CI 1.18–1.96), P=0.001], wheezing with sleep disturbances [OR per loge increment is 1.35 (95% CI 1.10–1.64), P=0.011] and wheezing with speech disturbances [OR per loge increment is 1.57 (95% CI 1.19–2.08), P=0.001]. These were adjusted for gender, pneumonia history, parental asthma, Trichuris infection, use of dry leaves as fuel and other specific IgE levels. The prevalence of Ascaris infection by the presence of wheezing was not significantly different (76% vs. 72%, respectively).Conclusion
We conclude that a high titre of anti‐Ascaris IgE is associated with an increased risk of asthma symptoms among 5‐year‐old rural Bangladeshi children with a high helminthic infectious load.
Glutamine preferentially inhibits T‐helper type 2 cell‐mediated airway inflammation and late airway hyperresponsiveness through the inhibition of cytosolic phospholipase A2 activity in a murine asthma model
Authors: Ko H. M. , Kang N. I. , Kim Y. S. , Lee Y. M. , Jin Z. W. , Jung Y. J. , Im S. Y. , Kim J. H. , Shin Y. H. , Cho B. H. , Lee H. K. 
Published: August 2010

SummaryBackground
The non‐essential amino acid, l‐glutamine (Gln), is abundant in the human body. Gln exhibits beneficial effects on endotoxic shock through the inhibition of cytosolic phospholipase A2 (cPLA2) activity. cPLA2 has been reported to be implicated in the pathogenesis of asthma, but the effects of Gln on asthma have not yet been defined.Objective
To investigate the effects of Gln on allergic bronchial inflammation and airway hyperresponsiveness (AHR), and to determine the possible action mechanisms of Gln in a murine model of asthma.Methods
cPLA2 phosphorylation was assessed by immunoprecipitation and Western blotting. Smears of bronchoalveolar lavage cells were stained with Diff‐Quik solution for differential cell counting. Airway levels of the proteins [T‐helper type‐1 (Th1) and Th2 cytokines, and mucin] were measured by ELISA. mRNA expression of cytokines was assessed by real‐time RT‐PCR. AHR was assessed as a change in airway resistance (RL). Histological studies were performed to assess the levels of mucin and pulmonary inflammation.Results
Systemic Gln administration inhibited cPLA2 phosphorylation and its enzymatic activity in the lungs. Additionally, Gln effectively suppressed the key features of Th2‐dependent asthmatic features, such as airway eosinophilia, mucus formation, and airway type 2 cytokine production, as well as late AHR.Conclusion
Gln was found to be effective in the suppression of Th2‐dependent phenotypes and late AHR, and this effect of Gln appeared to be at least partially attributable to its ability to suppress cLPA2 activity in the airway. Our results suggest that clinical use of Gln for patients with asthma may be beneficial.
Characterization of IgE epitopes of Cuc m 2, the major melon allergen, and their role in cross‐reactivity with pollen profilins
Authors: Tordesillas L. , Pacios L. F. , Palacín A. , Cuesta‐Herranz J. , Madero M. , Díaz‐Perales A. 
Published: August 2010

SummaryBackground
Plant profilins are described as minor allergens, although with some exceptions in foods such as melon, watermelon or orange. In fact, they could be responsible for many cross‐reactions among distantly related species. This is likely to be a consequence of the presence of common epitopes.Objective
To characterize the B epitopes of Cuc m 2, a model of plant food profilin, using phage display techniques and to compare with other profilins, such as those of timothy grass and birch pollen, and human I profilin, to understand the mechanism of cross‐reaction among members of this family.Methods
IgE of melon‐allergic patients was used to select clones from a phage display 12 mer peptide library. After two rounds of screening, Cuc m 2‐specific clones were eluted and the DNA insertion sequenced. The residues of each clone were mapped on the Cuc m 2 surface to define a mimotope, which was also localized on the three‐dimensional surfaces of other profilins.Results
Seventeen melon‐allergic patients were selected. Sera from each of them recognized the melon profilin, Cuc m 2, but the majority also recognized Phl p 12 or Bet v 2, timothy grass‐, and birch‐pollen profilins, respectively. A Cuc m 2 mimotope was defined and mapped onto its surface giving the following sequence: S2W3A5Y6D9H10T111P112G113Q114N116M117R121L122. The homologous residues in Phl p 12 and Bet v 2 had almost identical sequences. By contrast, the homologous sequence in human profilin showed many differences.Conclusions
The identified mimotope could be involved in cross‐reactions among food and pollen profilins. Many of these cross‐reactions observed in the clinical realm could be explained by the presence of a common epitope found in food and pollen allergens. A new strategy of immunotherapy based on this IgE region could be used in alternative immunotherapy strategies. Cite this as: L. Tordesillas, L. F. Pacios, A. Palacín, J. Cuesta‐Herranz, M. Madero and A. Díaz‐Perales, Clinical & Experimental Allergy, 2010 (40) 174–181.
The A to E of airway disease
Authors: Pavord I. D. , Wardlaw A. J. 
Published: August 2010

SummaryThe terms asthma and chronic obstructive pulmonary disease have evolved from their original very specific physiology‐based definition to describe additional disease entities such as symptoms, airway inflammation and airway structure. We argue that as a result there is widespread confusion about what the terms mean. This has become a significant hurdle to optimal disease management and drug development. We propose that these disease labels should be replaced with a new alphabetical assessment tool for characterizing airway disease, which provides a checklist of five relatively independent factors potentially responsible for morbidity in patients with airway disease: Airway hyperresponsiveness, Bronchitis, Cough reflex hypersensitivity, Damage to the airway and surrounding lung and Extrapulmonary factors. We speculate that the use of this system to characterize airway disease will improve outcomes by promoting better targeting of new and existing treatments. Cite this as: I. D. Pavord and A. J. Wardlaw, Clinical & Experimental Allergy, 2010 (40) 62–67.
The role of interleukin‐4Rα in the induction of glutamic acid decarboxylase in airway epithelium following acute house dust mite exposure
Authors: Hirota J. A. , Budelsky A. , Smith D. , Lipsky B. , Ellis R. , Xiang Y‐Y. , Lu W‐Y. , Inman M. D. 
Published: August 2010

SummaryBackground
Asthma is a disease characterized by airway inflammation, remodelling and dysfunction. Airway inflammation contributes to remodelling, a term that is used to describe structural changes including goblet cell metaplasia (GCM), matrix deposition, and smooth muscle hyperplasia/hypertrophy. GCM has been implicated in asthma mortality by contributing to mucus plugs and leading to asphyxiation. In animal models, this process is highly dependent on IL‐13. Recently, we have described an IL‐13‐dependent up‐regulation of a GABAergic signalling system in airway epithelium that contributes to GCM. The mechanism by which IL‐13 up‐regulates GABA signalling in airway epithelium is unknown.Objectives
To test the hypothesis that IL‐4Rα signalling is required for allergen induced up‐regulation of GABAergic signalling and GCM.Methods
BALB/c mice were exposed to an acute house dust mite (HDM) protocol and received vehicle, anti‐IL‐4Rα‐monoclonal antibody, or control antibody. Outcomes included airway responses to inhaled methacholine (MCh), histology for eosinophilia and GCM, phosphorylated STAT6 levels using immunohistochemistry and immunoblot, and glutamic acid decarboxylase (GAD) 65/67 and GABAAβ2/3 receptor subunit expression using confocal microscopy.Results
Acute HDM exposure resulted in increased airway responses to MCh, lung eosinophilia, STAT6 phosphorylation, elevations in GAD65/67 and GABAAβ2/3 receptor expression, and GCM that were inhibited with anti‐IL‐4Rα‐monoclonal treatment. Control antibody had no effect.Conclusion
The IL‐4Rα is required for allergen‐induced up‐regulation of a GABAergic system in airway epithelium implicated in GCM following acute HDM exposure. Cite this as: J. A. Hirota, A. Budelsky, D. Smith, B. Lipsky, R. Ellis, Y‐Y. Xiang, W‐Y. Lu and M. D. Inman, Clinical & Experimental Allergy, 2010 (40) 820–830.
Chemical and spectroscopic characterization of soil organic matter fractions isolated by sequential extraction procedure
Authors: SENESI N. , TESTINI C. , POLEMIO M. 
Published: August 2010

SummarySoil organic matter fractions were isolated from three soils by the application of a sequential extraction procedure employing a series of 10 mild organic solvents of different polarity.The isolated organic materials were characterized by elemental, infrared and electron spin resonance analyses. They showed different chemical and structural properties which varied according to the progression of the solvent series, with some similarities between two successive extracts. The corresponding fractions extracted from the three soils were substantially similar to each other in chemical character. Along each series of extracts aliphaticity appeared to decrease, whilst aromaticity, polar oxygenated and nitrogenated functional groups, transition metal ion content and organic free radical concentrations increased. ESR spectra were structured and were put in four different classes, according to their characteristic resonances.Although the yields of extracted organic material were not high, the fractions could be considered representative of the soil organic matter composition and furnish new chemical information on its nature and properties.
Granitic weathering: a Brazilian study
Authors: MELFI A. J. , CERRI C. C. , KRONBERG B. I. , FYFE W. S. , McKINNON B. 
Published: August 2010

SummaryChemical and mineral studies were carried out on weathered materials from six profiles developed on granites located in different areas of Brazil.Quartz and K‐feldspar are the most abundant minerals overall. Kaolinite is the most common secondary mineral and is principally a feldspar weathering product. Mica breakdown is associated with smectite formation in semi‐arid regions. In more humid regions mica weathering products include interlayered mica‐vermiculite, vermiculite and kaolinite. Changes in the concentrations of Si, Al and K reflect the weathering behaviour of quartz, kaolinite, K‐feldspar respectively, although K mobilities sometimes appear to be governed by processes related to the formation of secondary minerals. Ca and Mg are the first elements to exhibit depletion and their removal rates are very fast relative to K. P is also among the most mobile elements. Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba and Pb concentrations were measured. The first row transition metals are the most depleted. Rb and Sr are retained relative to Na, Mg, and Ca, and Ba accumulates as weathering proceeds. Y, Zr, Nb and Pb concentrations show little variation.The conclusion is that the factors controlling deep leaching are complex and the common notion that weathering rates are higher at lower latitudes should be reassessed.
Dissolution of feldspars in the presence of natural, organic solutes
Authors: LUNDSTRÖM U. , ÖHMAN L‐O. 
Published: August 2010

SUMMARYThe dissolution rates of feldspars in the presence of naturally occurring organic solutes were compared at pH 5.1. Natural silt or ground feldspar minerals were suspended in water, streamwater, soil water, water extracts of peat and mor and a citrate solution for approximately 100 d. The increase of major cations and silicic acid in the aqueous phase was determined by periodic sampling and rates of dissolution were calculated when concentration increased linearly with time.The dissolution rate for the major cations was 2.7±0.9 (n= 3) times greater for stream‐water and 2.4±0.4 (n= 5) times greater for mor and peat extract than for distilled water. For citrate, the rate was greater by 1.7±0.3 (n=3) times.By inoculating the suspensions with microorganisms weathering rates decreased to the value for distilled water. This suggests that the microorganisms consumed some ‘active’ fraction of the organic solutes.