Induction of transcription factor Egr-1 gene expression in astrocytoma cells by Murine coronavirus infection

AbstractMouse hepatitis virus (MHV) causes encephalitis and demyelination in the central nervous system (CNS) of susceptible rodents. Astrocytes are one of the major targets for MHV infection in the CNS, and respond to MHV infection by expressing diverse molecules that may contribute to CNS pathogenesis. Here we characterized the activation of an immediate-early transcription factor Egr-1 by MHV infection in an astrocytoma cell line. We found that the expression of Egr-1 was dramatically increased following virus infection. Using various inhibitors of mitogen-activated protein kinases, we identified that the extracellular signal-regulated kinases 1/2 were involved in the activation of Egr-1 transcription by MHV infection. Experiments with ultraviolet light-inactivated virus revealed that the induction of Egr-1 did not require virus replication and was likely mediated during cell entry. We further found that over-expression of Egr-1 suppressed the expression of BNip3, a pro-apoptotic member of the Bcl-2 family. This finding may provide an explanation for our previously observed down-regulation of BNip3 by MHV infection in astrocytoma cells (Cai, Liu, Yu, and Zhang, Virology 316:104–115, 2003). Furthermore, knockdown of Egr-1 by an siRNA inhibited MHV propagation, suggesting the biological relevance of Egr-1 induction to virus replication. In addition, the persistence/demylinating-positive strains (JHM and A59) induced Egr-1 expression, whereas the persistence/demylinating-negative strain (MHV-2) did not. These results indicate a correlation between the ability of MHVs to induce Egr-1 expression and their ability to cause demyelination in the CNS, which may suggest a potential role for the induction of Egr-1 in viral pathogenesis

Pyrolytic Characteristics and Kinetics of Phragmites australis

The pyrolytic kinetics of Phragmites australis was investigated using thermogravimetric analysis (TGA) method with linear temperature programming process under an inert atmosphere. Kinetic expressions for the degradation rate in devolatilization and combustion steps have been obtained for P. australis with Dollimore method. The values of apparent activation energy, the most probable mechanism functions, and the corresponding preexponential factor were determined. The results show that the model agrees well with the experimental data and provide useful information for the design of pyrolytic processing system using P. australis as feedstock to produce biofuel

Reduced RING finger protein 10 expression in macrophages is associated with aging‐related inflammation

Age‐associated decline of the immune system is referred to as immunosenescence. The E3 ligase RING finger 10 (RNF10) has long been associated with the innate immune response, although a potential role in immunosenescence has not previously been reported. In the present study, we identified that RNF10 expression is lower in aged mouse macrophages than in young cells. After lipopolysaccharide stimulation, RNF10 expression remained at a basal low level in aged mouse cells, but declined sharply in young mouse cells. Knockdown of RNF10 enhanced both the nuclear factor‐κB and interferon regulatory factor 3 signaling pathways and thus enhanced proinflammatory cytokines and type I interferons in macrophages, promoting clearance of Listeria monocytogenes. These findings indicate that dysregulated expression of RNF10 is associated with age‐associated immune dysfunction, and RNF10 may thus be a potential target for the treatment of age‐related inflammatory diseases

DNA-binding domain of GCN4 induces bending of both the ATF/CREB and AP-1 binding sites of DNA

The interaction of proteins with DNA results, in some cases, in DNA bending, and this might have functional importance. However, when the protein-induced bending of DNA is small, its measurement presents a problem. It is shown that the fluorescence resonance energy transfer between fluorophores placed on the ends of the specially designed U-shaped DNA, which contains the DNA-binding sites at its central part, can be successfully used for this purpose. The lever effect of the arms of such U-shaped DNA ensures that the distance between the fluorophores is very sensitive to bending of the central part. Using this technique, it was shown that (i) the AP-1 and ATF/CREB binding sites of GCN4 transcription factor are pre-bent to the same extent (∼12° toward the major groove) and (ii) binding of the GCN4 DNA-binding domain (GCN4-bZIP) results in additional bending of both these target sites but to a greater extent at the ATF/CREB site. In total, in the complex with GCN4-bZIP, the ATF/CREB site is bent by (25 ± 2)° and the AP-1 site by (20 ± 2)° toward the minor groove

An optimum method for latticed shells based on concept of the compression line

To improve the load-carrying capacity latticed shells, an innovative optimum method based on the concept of compression line is proposed in this paper. The basic principle of this method is using the character without moment in compression line. The arc line which forms the contour line of sphere and latticed shell structures is substituted by compression line in this method. Then the latticed shell structures are in the state of compression, and the influence of bending stress reduces greatly. As a result, the load-carrying capacity of the latticed shell structure is increased. Through the geometrical nonlinear analysis of a sunflower-patterned single-layer latticed shell structure with a span of 48m, it is found that the load-carrying capacity of the single-layer latticed shell structure can be improved by 5.48%. Furthermore, the results of 84 structural analyses of single-layer or double-layer sphere and cylinder latticed shell structures show that the optimum method is right and effective. And especially, it is applicable to single-layer latticed shell structure with rise-span ratio 1/5 with the max improvement 6.4% of load-carrying capacity

Ordered Mesoporous Ni-Fe-Al Catalysts for CO Methanation with Enhanced Activity and Resistance to Deactivation

A series of ordered mesoporous Ni-Fe-Al ternary oxide composites were prepared via a one-pot evaporation-induced self-assembly (EISA) method and applied in a CO methanation reaction to produce synthetic natural gas. The results showed that the ordered mesoporous Ni-Fe-Al catalyst with proper amount of Fe species (10N1FOMA) had better both CO conversion and CH4 selectivity than the impregnation-derived 10N1FA catalyst with unordered mesopores and identical component, owing to the higher Ni dispersion and larger H-2 uptake. In a 120 h atmospheric-pressure lifetime test, the ordered mesoporous 10N1FOMA catalyst showed significant enhancement in both antisintering and anticoking properties in comparison with the unordered mesoporous 10N1FA, mainly because of the confinement effect of the mesopore channels, the weak acidity of ordered mesoporous alumina support, and the smaller Ni particle size (&lt;5.0 nm).</p

Catalytic conversion of gaseous tars using land, coastal and marine biomass-derived char catalysts in a bench-scale downstream combined fixed bed system

The catalytic activity of biochar for tar removal was evaluated in a bench-scale combined fixed bed reactor by comparison of gaseous tar catalytic cracking behaviors over land (Corn stalks, Cs), coastal (Reed, Re) and marine (Sargassum horneri, Sh) char catalyst. The experiments demonstrated that the tar yield after addition of the biochar was reduced significantly; the tar conversion efficiency reached to 94.6% for catalytic at 850 degrees C with 50 mm char bed length using Re char. And the yield and composition of gas also changed markedly. The percentage of H-2 and CO in the product gas were obviously increased. Sh has a higher H-2 content (49.3% of the total gas content), whereas, CO dominated in the gas products for Cs (45.4%) and Re (48.1%). The results from GC-MS analysis illustrated that the increase in temperature promoted the tar cracking and also promotes the polymerization of some tar components

An optimum method for latticed shells based on concept of the compression line

To improve the load-carrying capacity latticed shells, an innovative optimum method based on the concept of compression line is proposed in this paper. The basic principle of this method is using the character without moment in compression line. The arc line which forms the contour line of sphere and latticed shell structures is substituted by compression line in this method. Then the latticed shell structures are in the state of compression, and the influence of bending stress reduces greatly. As a result, the load-carrying capacity of the latticed shell structure is increased. Through the geometrical nonlinear analysis of a sunflower-patterned single-layer latticed shell structure with a span of 48m, it is found that the load-carrying capacity of the single-layer latticed shell structure can be improved by 5.48%. Furthermore, the results of 84 structural analyses of single-layer or double-layer sphere and cylinder latticed shell structures show that the optimum method is right and effective. And especially, it is applicable to single-layer latticed shell structure with rise-span ratio 1/5 with the max improvement 6.4% of load-carrying capacity