Saccharomycopsis fibuligera possesses high alpha-amylase and glucoamylase activities that enable it to utilize raw starch as a carbon source. A expression cassette containing the promoter sequence of 3-phosphogylycerate kinase gene (PGK1p), the alpha factor signal sequence from Saccharomyces cerevisiae and the alpha-amylase coding sequence of S. fibuligera was constructed. The alpha-amylase expression cassette was inserted in the ILV2 locus of industrial brewer's yeast strain YSF-5 encoding alpha-acetolactate synthase (AHAS) by homologous recombination. The transformed yeast strain was selected on the media with starch as the sole carbon source and verified by PCR. The transformant exhibited secretive alpha-amylase activity, low AHAS activity and reduced diacetyl production. Effects of temperature, pH, and metal ions on the activity of the alpha-amylase expressed by the transformant were examined. The fermentation performance of host strain YSF-5 and the transformant was also examined.
Beer ; microbiology ; Diacetyl ; metabolism ; Glycogen Synthase Kinase 3 ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Recombination, Genetic ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomycopsis ; enzymology ; genetics ; alpha-Amylases ; biosynthesis ; genetics ; metabolism

The recombinant adenoviruses expressing miR-22 (Ad-miR-22) was constructed and the effect of Ad-miR-22 on insulin signal pathway and glucose uptake in HepG2 cells was analyzed. MiR-22 gene was amplified by PCR from human hepatocytes and cloned into the pAdTrack-CMV vector to generate the shuttle plasmid pAdT-22. The positive colonies were confirmed by PCR and sequencing. The resultant shuttle plasmid was linearized with Pme I, followed by co-transformation into competent BJ5183 cells containing an adenoviral backbone plasmid (pAdEasy-1) to create the recombinant plasmid pAd-miR-22. After digested with Pac I, the linearized pAd-miR-22 was transfected into 293A packaging cell line to generate recombinant adenoviruses Ad-miR-22. HepG2 cells were infected with Ad-miR-22 or control Ad-GFP (adenoviruses expressing green fluorescent protein), and then the miR-22 expression levels were analyzed by qPCR. The result shows that adenovirus-mediated overexpression of miR-22 significantly decreased insulin-induced glucose uptake in HepG2 cells. Moreover, overexpression of miR-22 markedly decreased insulin-induced phosphorylation of GSK-3β. miR-22 also increased the mRNA levels of gluconeogenic genes in HepG2 cells. Furthermore, Western blotting results indicate that the protein expression of SIRT1 decreased in Ad-miR-22 infected HepG2 cells as compared with Ad-GFP infected HepG2 cells. In summary, overexpressing of miR-22 significantly increased gluconeogenesis while decreased glucose uptake in HepG2 cells. The effect of miR-22 on glucose metabolism may be mediated by SIRT1.
Adenoviridae ; genetics ; Glucose ; metabolism ; Glycogen Synthase Kinase 3 beta ; metabolism ; Hep G2 Cells ; Humans ; MicroRNAs ; genetics ; metabolism ; Signal Transduction ; genetics ; Transfection

OBJECTIVETo explore the association of Snail expression and Lauren classification of gastric cancer.

METHODSThe protein levels of Snail and E-cadherin were detected by Western blot in N87 (intestinal-type gastric cancer cell line) and AGS(diffuse-type gastric cancer cell line) cell lines and those after transfection of GSK-3β plasmid. The study included a total of 77 patients with primary gastric cancer who underwent curative gastrectomy in the Zhongshan Hospital from February 2000 to December 2005 without any chemotherapy or radiation therapy before surgery. Tissues of gastric cancer specimens were stained using immunohistochemistry to determine Snail expression.

RESULTSSnail expression was low in N78 and high in AGS. E-cadherin expression showed reverse expression pattern. After transfection with GSK-3β, the expression of Snail was significantly suppressed and that of E-cadherin elevated (P<0.01). Different concentrations of GSK-3β inhibitor lithion chloride were used to treat the cell lines and Snail expression was significantly up-regulated in a dose-dependent manner (P<0.01). Snail expression was elevated in 16 out of 21 N78 cell lines, and in 21 out of 56 AGS cell lines, and the difference was statistically significant (P<0.01).

CONCLUSIONThe expression of Snail is closely associated with the Lauren classification of gastric cancer, and it may be a potential marker of the gastric cancer classification.

Cadherins ; metabolism ; Cell Line, Tumor ; Glycogen Synthase Kinase 3 ; genetics ; Humans ; Plasmids ; genetics ; Snail Family Transcription Factors ; Stomach Neoplasms ; classification ; metabolism ; pathology ; Transcription Factors ; metabolism ; Transfection

OBJECTIVETo observe the effect of Sam68 gene silencing on proliferation of nasopharyngeal carcinoma (NPC) cell line 5-8F and explore its possible molecular mechanism.

METHODSThe NPC cell line 5-8F was transfected with a small interfering RNA (siRNA) targeting Sam68 and the cell proliferation changes were observed. Quantitative RT-PCR and Western blotting were used to examine the changes in the expressions of Sam68, cell cycle-related proteins, and some up-stream proteins in the transfected cells.

RESULTSTransfection of 5-8F cells with Sam68-specific siRNA significantly lowered the mRNA and proteins levels of Sam68, suppressed cell proliferation, decreased the expression of Cyclin D1, and increased the expression of p27. The transfected cells showed obviously decreased expressions of p-FOXO3a, p-Akt and p-GSK-3β, but the expressions of FOXO3a, Akt and GSK-3β were not obviously affected.

CONCLUSIONSSam68 modulates the proliferation of NPC cells probably by activating Akt/FOXO3a pathway and regulating the cell proliferation-related molecules.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Carcinoma ; Cell Line, Tumor ; Cell Proliferation ; DNA-Binding Proteins ; genetics ; metabolism ; Forkhead Box Protein O3 ; Forkhead Transcription Factors ; metabolism ; Gene Silencing ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; RNA-Binding Proteins ; genetics ; metabolism

BACKGROUND: Sjögren's syndrome (SS) is an autoimmune disorder characterized by sicca syndrome and/or systemic manifestations. The treatment is still challenging. This study aimed to explore the therapeutic role and mechanism of exosomes obtained from the supernatant of stem cells derived from human exfoliated deciduous teeth (SHED-exos) in sialadenitis caused by SS. METHODS: SHED-exos were administered to the submandibular glands (SMGs) of 14-week-old non-obese diabetic (NOD) mice, an animal model of the clinical phase of SS, by local injection or intraductal infusion. The saliva flow rate was measured after pilocarpine intraperitoneal injection in 21-week-old NOD mice. Protein expression was examined by western blot analysis. Exosomal microRNA (miRNAs) were identified by microarray analysis. Paracellular permeability was evaluated by transepithelial electrical resistance measurement. RESULTS: SHED-exos were injected into the SMG of NOD mice and increased saliva secretion. The injected SHED-exos were taken up by glandular epithelial cells, and further increased paracellular permeability mediated by zonula occluden-1 (ZO-1). A total of 180 exosomal miRNAs were identified from SHED-exos, and Kyoto Encyclopedia of Genes and Genomes analysis suggested that the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathway might play an important role. SHED-exos treatment down-regulated phospho-Akt (p-Akt)/Akt, phospho-glycogen synthase kinase 3β (p-GSK-3β)/GSK-3β, and Slug expressions and up-regulated ZO-1 expression in SMGs and SMG-C6 cells. Both the increased ZO-1 expression and paracellular permeability induced by SHED-exos were abolished by insulin-like growth factor 1, a PI3K agonist. Slug bound to the ZO-1 promoter and suppressed its expression. For safer and more effective clinical application, SHED-exos were intraductally infused into the SMGs of NOD mice, and saliva secretion was increased and accompanied by decreased levels of p-Akt/Akt, p-GSK-3β/GSK-3β, and Slug and increased ZO-1 expression. CONCLUSION Local application of SHED-exos in SMGs can ameliorate Sjögren syndrome-induced hyposalivation by increasing the paracellular permeability of glandular epithelial cells through Akt/GSK-3β/Slug pathway-mediated ZO-1 expression.
Mice ; Animals ; Humans ; Sjogren's Syndrome/therapy* ; Proto-Oncogene Proteins c-akt/metabolism* ; Tight Junctions/metabolism* ; Glycogen Synthase Kinase 3 beta ; Mice, Inbred NOD ; Phosphatidylinositol 3-Kinases/metabolism* ; Exosomes/metabolism* ; Xerostomia ; Phosphatidylinositol 3-Kinase ; MicroRNAs/genetics*

OBJECTIVETo investigate the effect of risperidone, an antipsychotic drug, on the Akt-GSK3β pathway and the role of PI3K in dopamine D2 receptor (DRD2) expression and Akt-GSK3β signal pathway.

METHODSHuman glioma cells (U251) were cultured in vitro. Cells without any treatment as control, Western blotting was used for measuring the expression of Akt (Thr308 and Ser473) and GSK3β (Ser9) protein phosphorylation by risperidone and LY294002 in U251 cell, and real-time PCR was used for detecting the expression of DRD2 mRNA.

RESULTSRisperidone has significantly enhanced the expression of phosphorylated Akt and phosphorylated GSK3β (P< 0.05), but did not alter the mRNA expression of DRD2. LY294002 could reduce the phosphorylation of Akt and GSK3β (P< 0.01, P< 0.05), and also decrease the DRD2 mRNA (P<0 .05).

CONCLUSIONRisperidone can activate the Akt-GSK3β signaling pathway in the U251 cells, and PI3K is a common regulatory site in Akt-GSK3β signaling and D2 receptor gene expression.

Antipsychotic Agents ; pharmacology ; Cell Line, Tumor ; Glioma ; drug therapy ; genetics ; metabolism ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Phosphatidylinositol 3-Kinases ; genetics ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Risperidone ; pharmacology ; Signal Transduction ; drug effects

OBJECTIVETo discuss the changes in Wnt pathway inhibiting factors in esophageal precancerosis lesions induced by methyl benzyl nitrosamine (MBNA) and the effect of Gexia Zhuyu decoction.

METHODWistar rats were subcutaneously injected with MBNA (3.5 mg x kg(-1) for twice per week to establish the model. Since the 1st day after the model establishment, they were orally administered with Gexia Zhuyu decoction (16, 8 mg x kg(-1)). At the 10th week, esophageal tissues were collected to observe the pathological changes of esophageal mucosa, detect SFRP1, sFRP4, Axin1, Axin2 and GSK-3β mRNA levels.by fluorescent quantitation PCR analysis and β-catenin protein level by Western blotting.

RESULTBeing induced by MBNA, rats in the model group showed slight atypical hyperplasia in the histopathological examination. Compared with the normal group, Gexia Zhuyu decoction dose high and low groups showed no significant pathomorphological and histological changes. The model group showed lower gene transcription levels of esophageal tissues sFRP1, sFRP4, Axin1 and Axin2 (P < 0.05 or P < 0.01) and higher β-catenin protein expression level (P < 0.01) than the normal control group. The Gexia Zhuyu decoction low dose group showed higher gene transcription levels of esophageal tissues sFRP1, sFRP4, Axin1 and Axin2 (P < 0.05 or P < 0.01) and lower β-catenin protein expression level (P < 0.01) than the normal control group.

CONCLUSIONUp-regulated β-catenin protein level and down-regulated Wnt pathway could enhance Wnt pathway activity of MBNA-induced esophageal precancerous lesions. Gexia Zhuyu decoction could down-regulate the β-catenin protein level and up-regulate the transcription level of Wnt pathway inhibiting factors, but could not block MBNA-induced esophageal precancerosis lesions.

Animals ; Axin Protein ; genetics ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; Esophageal Diseases ; drug therapy ; genetics ; metabolism ; pathology ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Male ; Necrosis ; Nitrosamines ; adverse effects ; Proteins ; genetics ; metabolism ; Rats ; Rats, Wistar ; Wnt Proteins ; genetics ; metabolism ; Wnt Signaling Pathway ; drug effects

OBJECTIVETo investigate the effect of glycogen synthase kinase-3beta (GSK-3beta) on the proliferation of human ovarian cancer cells.

METHODSTwo human ovarian cancer cell lines SKOV3 and ES-2 were analysed for the expression of GSK-3beta and phosphorylated GSK-3beta (pGSK-3beta) by Western blot analysis. Cell growth curve analysis done by cell count was used to investigate the effect of GSK-3beta inhibitors on the growth of SKOV3 and ES-2 cells. Four plasmids, namely, GSK-3betaS9A, GID5-6, GID5-6LP and the control vector, were cotransfected respectively with the green fluorescent protein (GFP) into SKOV3 cells by electroporation, and then BrdU incorporation assay was adopted to analyse the role of GSK-3beta activity in the proliferation of ovarian cancer cells. After transfection, G418 was added to the medium to select those stably transfected cells, which were used to investigate the long term effect of GSK-3beta activity change on the proliferation of ovarian cancer cells by colony formation assay.

RESULTSBoth SKOV3 and ES-2 cells expressed GSK-3beta, though the expression level of pGSK-3beta was lower in SKOV3 than in ES-2 cells. GSK-3beta inhibitors attenuated the growth of SKOV3 and ES-2 cells. Transfection with GSK-3betaS9A to upregulate the GSK-3beta activity resulted in the increase of BrdU incorporation in SKOV3 cells compared with that in the control vector. On the contrary, transfection with GID5-6 to downregulate GSK-3beta activity decreased the BrdU incorporation in SKOV3 cells, compared with that in GID5-6LP, which is a control vector of GID5-6. Stable transfection with GSK-3betaS9A increased the colony number while stable transfection with GID5-6 decreased the colony number, compared with each control vector.

CONCLUSIONGSK-3beta can promote the proliferation of ovarian cancer cells. Inhibition of GSK-3 p may become a potential theraputic

Blotting, Western ; Cell Line, Tumor ; Cell Proliferation ; Female ; Glycogen Synthase Kinase 3 ; antagonists & inhibitors ; genetics ; metabolism ; Glycogen Synthase Kinase 3 beta ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Indoles ; pharmacology ; Lithium Chloride ; pharmacology ; Maleimides ; pharmacology ; Microscopy, Fluorescence ; Ovarian Neoplasms ; enzymology ; genetics ; pathology ; Phosphorylation ; drug effects ; Plasmids ; genetics ; Serine ; genetics ; metabolism ; Time Factors ; Transfection ; beta Catenin ; metabolism

Aortic valve calcification (AVC) is a pathological process correlated with multiple disease causes and actively regulated by cardiac valve cells. In this study, porcine aortic valve myofibroblasts cultured in vitro were treated with 50 μg z L(-1) of pathological factor tumor necrosis factor α (TNF-α). Tanshinone II A (TSN) with the concentration of 50 mg x L(-1) and TNF-α were combined in incubating cells for 72 h (3 d) and 120 h (5 d). The Western blotting and Real-time PCR were adopted to detect the changes in smooth muscle α actin (α-SMA), bone morphogenetic protein 2 ( BMP2), alkaline phosphatase (ALP) in cells, and expressions of key effect proteins GSK-3β and β-catenin on Wnt/β-catenin signal pathway. According to the findings, TNF-α can significantly increase the expression of myofibroblasts α-SMA and add the transformation activity to them, with nearly no expression of BMP2, ALP and mRNA in the control group and the TSN group but significant increase in their expressions in the TNF-α group (P < 0.01), which showed osteoblast-like phenotype. Moreover, TNF-α down-regulated the expression of up-streaming regulator GSK-3β and mRNA expression (P < 0. 01) , notably increased the expression of key effect protein β-catenin, but with no significant difference in mRNA with the control group and the TSN group. The result demonstrated that TSN showed a certain inhibitory effect on TNF-α's pathological impact (P < 0.05) in a time-dependent manner. Inflammatory factor TNF-α may promote the transformation of aortic valvular myofibroblasts to osteoblast-like phenotype by activating Wnt/β-catenin signal pathway in aortic valvular myofibroblasts, so as to cause AVC. Tanshinone II A can have a preventive effect in AVC by activating GSK-3β proteins and regulating signal transduction of Wnt/β-catenin signal pathway.
Animals ; Aortic Valve ; cytology ; drug effects ; metabolism ; Cells, Cultured ; Diterpenes, Abietane ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Glycogen Synthase Kinase 3 beta ; Myofibroblasts ; cytology ; drug effects ; metabolism ; Osteoblasts ; cytology ; drug effects ; metabolism ; Swine ; Tumor Necrosis Factor-alpha ; genetics ; metabolism ; beta Catenin ; genetics ; metabolism

OBJECTIVETo study the effect of ginsenoside Rb1 on GSKbeta/IDE signal transduction pathway and Abeta protein secretion in hippocampal neurons of high glucose-treated rats.

METHODHippocampal neurons of 24 h-old newly born SD rats were primarily cultured, inoculated in culture medium under different conditions, and then divided into the normal group, the high glucose group, the LiCl group and the Rb1 group. After being cultured for 72 h, the expressions of their phosphorylated GSK3beta, total GSK3beta and IDE protein were detected by Western blotting analysis. The mRNA expressions of GSK3beta and IDE were determined by RT-PCR. The ELISA assay was used to detect the secretion of Abeta protein in cell supernatant.

RESULTCompared with the normal group, the high glucose group showed increase in the p/tGSK3beta protein ratio and the secretion of Abeta protein and decrease in IDE protein and mRNA (P < 0.05). Compared with the high glucose group, both Rb1 and LiCl groups showed decrease in the p/tGSK3beta protein ratio and the expression of Abeta protein and increase in IDE protein and mRNA expression (P < 0.05). Compared with the LiCl group, the Rb1 group showed no significant difference in the expressions of p/tGSK3beta protein, IDE protein, mRNA and Abeta protein expression. In addition, the GSK3beta mRNA expression of the four groups had no significant difference.

CONCLUSIONGinsenoside Rb1 may reduce the secretion of Abeta protein in hippocampal neurons by reducing the phosphorylation of GSK3beta, down-regulating the ratio of pGSK3beta/GSK3beta and upregulating the expression of IDE.

Amyloid beta-Peptides ; genetics ; metabolism ; secretion ; Animals ; Dietary Carbohydrates ; adverse effects ; Gene Expression Regulation ; drug effects ; Ginsenosides ; pharmacology ; Glucose ; adverse effects ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Glycogen Synthase Kinase 3 beta ; Hippocampus ; cytology ; Insulin ; metabolism ; Insulysin ; genetics ; metabolism ; Neurons ; cytology ; drug effects ; metabolism ; secretion ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects