Tumor necrosis factor regulates intestinal epithelial cell migration by receptor-dependent mechanisms

Altered mucosal integrity andincreased cytokine production, including tumor necrosis factor (TNF),are the hallmarks of inflammatory bowel disease (IBD). In this study,we addressed the role of TNF receptors (TNFR) on intestinal epithelialcell migration in an in vitro wound closure model. With mouse TNFR1 orTNFR2 knockout intestinal epithelial cells, gene transfection, andpharmacological inhibitors, we show a concentration-dependentreceptor-mediated regulation of intestinal cell migration by TNF. Aphysiological TNF level (1 ng/ml) enhances migration through TNFR2,whereas a pathological level (100 ng/ml) inhibits wound closure through TNFR1. Increased rate of wound closure by TNFR2 or inhibition by TNFR1cannot be explained by either increased proliferation orapoptosis, respectively. Furthermore, inhibiting Src tyrosine kinase decreases TNF-induced focal adhesion kinase (FAK) tyrosine phosphorylation and cellular migration. We therefore conclude thatTNFR2 activates a novel Src-regulated pathway involving FAK tyrosinephosphorylation that enhances migration of intestinal epithelial cells.

     

Specific binding of activated Vip3Aa10 to Helicoverpa armigera brush border membrane vesicles results in pore formation

Helicoverpa armigera is one of the most harmful pests in China. Although it had been successfully controlled by Cry1A toxins, some H. armigera populations are building up resistance to Cry1A toxins in the laboratory. Vip3A, secreted by Bacillus thuringiensis, is another potential toxin against H. armigera. Previous reports showed that activated Vip3A performs its function by inserting into the midgut brush border membrane vesicles (BBMV) of susceptible insects. To further investigate the binding of Vip3A to BBMV of H. armigera, the full-length Vip3Aa10 toxin expressed in Escherichia coli was digested by trypsin or midgut juice extract, respectively. Among the fragments of digested Vip3Aa10, only a 62 kDa fragment (Vip3Aa10-T) exhibited binding to BBMV of H. armigera and has insecticidal activity. Moreover, this interaction was specific and was not affected by the presence of Cry1Ab toxin. Binding of Vip3Aa10-T to BBMV resulted in the formation of an ion channel. Unlike Cry1A toxins, Vip3Aa10-T was just slightly associated with lipid rafts of BBMV. These data suggest that although activated Vip3Aa10 specifically interacts with BBMV of H. armigera and forms an ion channel, the mode of action of it may be different from that of Cry1A toxins.     

Life cycle energy and GHG emissions of PET recycling: change-oriented effects

Purpose  

The demand of PET bottles has increased rapidly in the past decades. The purpose of this study is to understand the environmental impact of PET recycling system, in which used bottles are recycled into both fibre and bottles, and to compare the recycling system with single-use PET.     

Genes "waiting" for recruitment by the adaptive immune system: the insights from amphioxus

In seeking evidence of the existence of adaptive immune system (AIS) in ancient chordate, cDNA clones of six libraries from a protochordate, the Chinese amphioxus, were sequenced. Although the key molecules such as TCR, MHC, Ig, and RAG in AIS have not been identified from our database, we demonstrated in this study the extensive molecular evidence for the presence of genes homologous to many genes that are involved in AIS directly or indirectly, including some of which may represent the putative precursors of vertebrate AIS-related genes. The comparative analyses of these genes in different model organisms revealed the different fates of these genes during evolution. Their gene expression pattern suggested that the primitive digestive system is the pivotal place of the origin and evolution of the AIS. Our studies support the general statement that AIS appears after the jawless/jawed vertebrate split. However our study further reveals the fact that AIS is in its twilight in amphioxus and the evolution of the molecules in amphioxus are waiting for recruitment by the emergence of AIS.     

Antimicrobial and cytotoxic activities of neolignans from Magnolia officinalis

In the light of the steady increase of infections related to vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA), the medicinal plant Magnolia officinalis was subjected to bioassay-directed fractionation, which led to the isolation of the known neolignans piperitylmagnolol (1), magnolol (2), and honokiol (3) from the MeOH extract. In broth-microdilution assays, 1-3 exhibited antibacterial activities against VRE and MRSA at minimum-inhibitory concentrations (MIC) in the range of 6.25-25 microg/ml, compound 1 being the most-potent antibiotic. The ratio of MBC/MIC (MBC = minimum bactericidal concentration) was < or = 2 for all compounds. The kinetics of the antibacterial action of 1 and 3 were studied by means of time-kill assays; both compounds were bactericidal against VRE and MRSA, their actions being time dependent, or both time and concentration dependent. Magnolol (2) was acetylated to magnolol monoacetate (4) and magnolol diacetate (5) (partial or full masking of the phenolic OH functions). The cytotoxic properties of 1-5 against human OVCAR-3 (ovarian adenocarcinoma), HepG2 (hepatocellular carcinoma), and HeLa (cervical epitheloid carcinoma) cell lines were evaluated. The CD50 values for compounds 1-3 were in the range of 3.3-13.3 microg/ml, derivatives 4 and 5 being much less potent. This study indicates that piperitylmagnolol (= 3-[(1S,6S)-6-isopropyl-3-methylcyclohex-2-enyl]-5,5'-di(prop-2-enyl)[1,1'-biphenyl]-2,2'-diol; 1) possesses both significant anti-VRE activity and moderate cytotoxicity against the above cancer cell lines.     

Analysis of Protein Three-Dimension Structure Using Amino Acids Depths

The issue of amino acid depth in proteins gives important insights to our understanding of protein’s three-dimensional structure. There has already been much research done in mathematical and statistical sciences regarding the general definitions, properties and algorithms describing the particle depth of spatially extended systems. We constructed a method of calculating the amino acids depths and applied it to a set of 527 protein structures. We propose the introduction of amino acid depth tendency factors for three-dimensional structures of proteins. The depth tendency factors relate not only to the hydrophobicity indices but also to the electrostatic charge. We found a relationship between the protein size and the number of residues using the distance between the deepest residue and surface residues. We made a prediction regarding the number of residues on the surface of a protein, the deepest amino acid, and the average depth, all of which are fitted well to a linear functional relationship with the length of the protein. Finally, we have predicted the depths of multiple peptides in protein’s three-dimension structure. Electronic supplementary material The online version of this article () contains supplementary material, which is available to authorized users.     

Plasma Adiponectin Levels and Metabolic Factors in Nondiabetic Adolescents

Objectives: The relationship of plasma adiponectin levels with various anthropometric and metabolic factors has been surveyed extensively in adults. However, how plasma adiponectin levels are related to various anthropometric indices and cardiovascular risk factors in adolescents is not as vigorously studied. In this study, we investigated this among healthy nondiabetic adolescents. Research Methods and Procedures: Two hundred thirty nondiabetic subjects (125 boys and 105 girls, ～10 to 19 years old) were included. The plasma adiponectin, fasting plasma glucose, insulin, lipids and anthropometric indices including body height, weight, waist circumference, and hip circumference were examined. Body fat mass (FM) and percentage were obtained from DXA scan. The homeostasis model assessment was applied to estimate the degree of insulin resistance. Results: The plasma adiponectin levels were significantly higher in girls (30.79 ± 14.48 μg/mL) than boys (22.87 ± 11.41 μg/mL). The plasma adiponectin levels were negatively related to BMI, FM, FM percentage, waist circumference, waist‐to‐hip ratio, insulin resistance, plasma insulin, triglycerides, and uric acid levels, but positively with high‐density lipoprotein cholesterol (HDL‐C) with the adjustment for age and gender. Using different multivariate linear regression models, only age and HDL‐C were consistently related to the plasma adiponectin levels after adjustment for the other variables. Discussion: The relationship between plasma adiponectin and various anthropometric indices and metabolic factors, especially HDL‐C, previously reported in adults was present in the healthy nondiabetic adolescents. Whether variation of plasma adiponectin levels in healthy nondiabetic adolescents may influence their future coronary artery disease risk warrants further investigation.     

Status of water environment pollution in the Xixi Wetland and its ecological treatment countermeasures

In this paper,the water quality of the Xixi Wetland was evaluated and the characteristics of water pollution were described according to the survey data.Based on the status of water quality and its functional requirements as an urban wetland,biological-ecological countermeasures were suggested.The experimental use of ecological technologies,such as artificial wetlands,ecological aquiculture and artificial floating island,were done in several fish ponds in the Xixi Wetland.Water monitoring results show that the quality of the treated water has improved significantly and the measures to purify the eutrophic water in the wetland have been effective.