Characterization of ß-glucosidase from Aspergillus terreus and its application in the hydrolysis of soybean isoflavones.

An extracellular ß-glucosidase produced by Aspergillus terreus was identified, purified, characterized and was tested for the hydrolysis of soybean isoflavone. Matrix-assisted laser desorption/ionization with tandem time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS) revealed the protein to be a member of the glycosyl hydrolase family 3 with an apparent molecular mass of about 120 kDa. The purified ß-glucosidase showed optimal activity at pH 5.0 and 65 °C and was very stable at 50 °C. Moreover, the enzyme exhibited good stability over pH 3.0-8.0 and possessed high tolerance towards pepsin and trypsin. The kinetic parameters Km (apparent Michaelis-Menten constant) and Vmax (maximal reaction velocity) for p-nitrophenyl-ß-D-glucopyranoside (pNPG) were 1.73 mmol/L and 42.37 U/mg, respectively. The Km and Vmax for cellobiose were 4.11 mmol/L and 5.7 U/mg, respectively. The enzyme efficiently converted isoflavone glycosides to aglycones, with a hydrolysis rate of 95.8% for daidzin, 86.7% for genistin, and 72.1% for glycitin. Meanwhile, the productivities were 1.14 mmol/(L·h) for daidzein, 0.72 mmol/(L·h) for genistein, and 0.19 mmol/(L·h) for glycitein. This is the first report on the application of A. terreus ß-glucosidase for converting isoflavone glycosides to their aglycones in soybean products.

[Attachment and spreading of fibroblasts on titanium coatings by different micro-arc oxidation time].

PURPOSE: To investigate the attachment and spreading of fibroblasts on titanium coatings by different micro-arc oxidation(MAO) time. METHODS: Micro-arc oxidation film was formed on the titanium surface by using micro-arc oxidation. The film morphology and the cell shape on the samples were observed by scanning electron microscopy (SEM) and the surface roughness of film with different time was analyzed by surface coarseness profiling instrument. SPSS11.5 software package was used to analyze the data. RESULTS: The experiment result showed, the coatings were rough and porous, the longer oxidation time, the larger diameter of porous but the less porous numbers. As the treatment time increased, the surface roughness of micro-arc oxidation specimens increased (P<0.05). Compared with titanium, fibroblasts on titanium MAO coatings had more abundant spreading and adhesion. At 24 h, 48 h and 72 h, the cell number on coatings adhesion increased, but with different oxidation time, the cell shape, number and adhesion weren't obviously changed. CONCLUSIONS: The results indicate that microarc oxidation increases the surface roughness, have a good influence on cell adhesion and spreading.

CRTH2 antagonist ameliorates airway inflammation in rats with asthma / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effect of prostaglandin D2 receptor antagonists on the airway inflammation in rats with asthma.</p><p><b>METHODS</b>Forty male SD rats were randomly divided into four groups: Group A (normal control), Group B (asthma group), Group C (CRTH2 antagonist BAYu3405 treatment group), Group D (DP1 antagonist BWA868C treatment group). Asthma was induced by ovalbumin (OVA) challenge. The rats in each group were sacrificed 24 h after the last challenge of OVA.DP1/CRTH2 receptors on eosinophils (EOS) were measured by radiological binding assay (RBA). The left lungs were used for histological examinations and bronchoalveolar lavage fluid (BALF) was collected from the right lungs. The total cell numbers, EOS absolute count and differential cell counts in BALF were performed. Serum concentrations of IL-4, 5 and IFN-gamma were measured by ELISA.</p><p><b>RESULTS</b>Rats in BAYu3405 treatment group showed profoundly decreased infiltrates of EOS and lymphocytes in the wall of bronchus when compared with those of asthma group and BWA868C treatment group. Serum concentrations of IFN-gamma in rats of BAYu3405 treatment group increased, but IL-4 and IL-5 decreased significantly when compared with those in rats of asthma group and BWA868C treatment group (P<0.01), and BALF EOS count was decreased significantly (P<0.01). Peripheral blood EOS count was higher than that in rats of normal control group, but was not significantly different from that in rats of asthma group and BWA868C treatment group. The combining capacity of CRTH2 and DP total combining capacity on EOS in asthma group, BAYu3405 treatment group and BWA868C treatment group were significantly higher than those in Group A (P<0.01). There was no significant difference in DP1 among all the groups (P>0.05).</p><p><b>CONCLUSION</b>CRTH2, but not DP1 antagonist can effectively ameliorate airway inflammation in rats with asthma.</p>

Changes of prostaglandin D2 receptor on T cells in peripheral blood of children with asthma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Chronic airway inflammation is associated with the polarization of TH2 cells in asthma. Prostaglandin D2 (PGD2) plays an important role in the polarization of TH2 cells. This study aimed to investigate the changes of PGD2 receptors (DP1/CRTH2) on T lymphocytes and their significance in asthma.</p><p><b>METHODS</b>Seventy-two children with asthma were assigned to two groups: acute attack (n=42) and remission (n=30). Thirty-five healthy children were used as the control group. Plasma levels of TH2 cytokines IL-4 and IL-5, and TH1 cytokine INF-gamma were detected using ELISA. Radiological binding assay (RBA) was used to measure the contents of DP1/CRTH2 receptors on T cells in peripheral blood (PPB).</p><p><b>RESULTS</b>The total combining contents of DP and CRTH2 on T cells in PPB in the acute attack and the remission groups were significantly higher than those in the control group (p<0.01). There was no significant difference in the DP1 content among the three groups. Serum levels of IL-4 and IL-5 significantly increased (p<0.01), in contrast, serum levels of TH1 cytokine IFN-gamma were significantly reduced in the acute attack and the remission groups compared with those in the control group (p<0.01).</p><p><b>CONCLUSIONS</b>The total combining contents of DP and CRTH2 on T cells increased, serum levels of TH2 cytokines also increased, but serum levels of TH1 cytokine decreased significantly in the acute attack and the remission phases in children with asthma. This showed that a polarization of TH2 cells occurred in children with asthma and suggested that CRTH2 antagonism may be a new target for the treatment of asthma.</p>

Hemangiopoietin, a novel human growth factor for the primitive cells of both hematopoietic and endothelial cell lineages.

The cells of hematopoietic and vascular endothelial cell lineages are believed to share a common precursor, termed hemangioblast. However, the existence of a growth factor acting relatively specifically on hemangioblasts remains unclear. Here we report the identification of hemangiopoietin (HAPO), a novel growth factor acting on both hematopoietic and endothelial cell lineages. In vitro in the human system, recombinant human HAPO (rhHAPO) significantly stimulated the proliferation and hematopoietic and/or endothelial differentiation of human bone marrow mononuclear cells and of purified CD34+, CD133+, kinase domain receptor-positive (KDR+), or CD34+/KDR+ cell populations. In the murine system, rhHAPO stimulated the proliferation of long-term culture-initiating cells (LTC-ICs) as well as CD34+ and stem cell antigen-1 (Sca-1+) cell subsets. In vivo, subcutaneous injection of rhHAPO into normal mice resulted in a significant increase in bone marrow hematopoietic cells. Furthermore, irradiated mice injected with rhHAPO had an enhanced survival rate and accelerated hematopoiesis. Our data suggest that HAPO is a novel growth factor acting on the primitive cells of both hematopoietic and endothelial cell lineages and that HAPO may have a clinical potential in the treatment of various cytopenias and radiation injury and in the expansion of hematopoietic and endothelial stem/progenitor cells.