Biomedical subjects

Qing Xiang Shen

Publications and source records attributed to Qing Xiang Shen.

6 recordsLinked to original sources

PubMed2006

[Uterine expression of adenovirus E4 promoter-binding protein 4 (E4BP4) during the embryo implantation period in mice].

Adenovirus E4 promoter-binding protein 4 (E4BP4), a mammalian basic leucine zipper (bZIP) nuclear transcription factor, was identified to be involved in cell survival and proliferation. Previous research data showed that the expression of E4BP4 gene was up-regulated at the implantation sites on day 5 pregnancy of mouse. The aim of the present study was to examine the expression pattern of E4BP4 gene in uterus during pre-implantation period, and at the implantation sites and inter-implantation sites during the implantation process, through the Northern blot, in situ hybridization, Western blot and immunohistochemistry analyses. It was found that, (1) during the pre-implantation period, the expression of E4BP4 gene was gradually increased; (2) its expression was sharply up-regulated at the implantation sites compared with that at the inter-implantation sites during the embryo implantation process; (3) the uterine expression of E4BP4 gene was not embryo-dependent, but observed in artificially induced decidulization of pseudopregnant mouse; (4) both E4BP4 mRNA and E4BP4 protein were localized in stromal cells and decidual cells around the uterine lumen. These results indicated that E4BP4 may play a critical role in embryo implantation process by promoting stromal cell proliferation and inhibiting decidual cell apoptosis.

Animals↗

PubMed2005

[Expression of HCGbeta-CTP polymeride by the methylotropic yeast, pichia pastoris and structure prediction of the expressed products].

To investigate the expression of CTP encoding gene in the methylotropic yeast, pichia pastoris and the possibility of CTP acting as an antifertility vaccine or anti-cancer vaccine, we strung two, three or four CTP cDNA to construct CTP polymeric cDNA in order to enhance the immunogenicity of the CTP. Then, the recombinant genes were subcloned into a pichia pastoris expression vector pPIC9K to construct pPIC9K-(hCGbeta-CTP37)n(n = 2,3,4). After identified by restriction endonuclease digestion and DNA sequencing, the recombinant vectors were linearized and transferred into GS115 by electroporation. The induced culture supernatant was precipitated by PEG6000 and the precipitate was washed by 75% alcohol. SDS-PAGE and RIA analysis suggested GS115 expressed the recombinant genes successfully and the recombinant protein had anti-hCG antibody binding activity. In addition, ANTHEPROT 4.3 software was used to analyze the protein structure of CTP quadrigeminum. We found that CTP quadrigeminum had similar secondary structure with hCGbeta, but the speciality of antigen better than that of the latter. Therefore, we conclude that this study prepared basic necessary data for developing antifertility vaccines or anticancer vaccines basing on hCGbeta--CTP37.

Blotting, Western↗

PubMed2005

[The study on the construction of expression plasmid containing rHO-1 cDNA, analysis of rHO-1 activity and function of anti-apoptosis in HUVEC].

Xenograft rejection are due to the activation of endothelial cells and the expression of a series of proinflammatory genes encoding adhesion molecules, cytokines/chemokines and procoagulant molecules,leading to endothelial cell injury and apoptosis. HO-1 which acts as a cytoprotective gene can suppress a variety of inflammatory responses to prevent graft rejection. In this study, The plasmid containing HO-1 cDNA was constructed and transfected into human vascular endothelial cells (HUVEC) for expression using DOTAP lipsomal transfection reagents. Cells were homogenized in cell culture lysis reagent (CCLR) and the activity of HO-1 was measured. The apoptosis of HUVEC induced by tumor necrosis factor (TNF)-alpha was analyzed by flow cytometry. Meanwhile, Heme and Sn-protoporphyrin (SnPP) were added respectively to evaluate the apoptosis rate of HUVEC. The results showed that the expression of HO-1 gene can be significantly up-regulated in HUVEC transfected with pcDNA3HO1. The apoptosis rate of cells treated with Heme was less than 20% but significantly increased when cells treated with SnPP, the maximum arrived at 95%. The apoptosis rate in heme induced cells was 5-20 times lower than that in SnPP inhibited cells. The apoptosis rate was a negative relation to HO-1 expression. HO-1 protein can inhibit apoptosis in HUVEC. The results provide evidence to support the essential role of HO-1 in the cytoprotective function.

Animals↗

PubMed2004

[Expression of human follicle stimulating hormone in insect cells].

To study the expression of hFSH in insect cells, the cDNA encoding the hFSH beta chain was cloned by overlapping-PCR using human chromosome DNA extracted from placental tissue as template. Then we constructed expression vector pVL1393/hFSH beta using an unfused protein nuclear polyhedrosis virus (AcNPV) expression vector. The insect cells (SF9) were cotransfected with the expression vector and nuclear polyhedrosis linearized virus DNA, and recombinant viruses AcNPV-hFSH beta were collected. The beta subunit of hFSH expressed in plasma of the SF9 cells was detected by Western blot analysis, and showed apparent molecular masses of 21 kDa. After coinfecting SF9 cells with recombinant viruses AcNPV-hFSH beta and AcNPV-hCG alpha, secreted heterodimer of hFSH was detected by Western blot under non-reducing conditions. The apparent molecular weight of heterodimer was about 33 kDa.

Animals↗

PubMed2004

[hHO-1 structure prediction and its mutant construct, expression, purification and activity analysis].

Human Heme Oxygenase-1 (hHO-1) is the rate-limiting enzyme in the catabolism reaction of heme, which directly regulates the concentration of bilirubin in human body. The mutant structure was simulated by Swiss-pdbviewer procedure, which showed that the structure of active pocket was changed distinctly after Ala25 substituted for His25 in active domain, but the mutated enzyme still binded with heme. On the basis of the results, the expression vectors, pBHO-1 and pBHO-1(M), were constructed, induced by IPTG and expressed in E. coli DH5alpha strain. The expression products were purified with 30%-60% saturation (NH4)2SO4 and Q-Sepharose Fast Flow column chromatography. The concentration of hHO-1 in 30%-60% saturation (NH4)2SO4 components and in fractions through twice column chromatography was 3.6-fold and 30-fold higher than that in initial product, respectively. The activity of wild hHO-1 (whHO-1) and mutant hHO-1 (deltahHO-1) showed that the activity of deltahHO-1 was reduced 91.21% compared with that of whHO-1. The study shows that His25 is of importance for the mechanism of hHO-1, and provides the possibility for effectively regulating the activity to exert biological function.

Blotting, Western↗

PubMed2002

[Expression of monoclonal nonspecific suppressor factor beta in E. coli, preparation of its antibodies and its tissue orientation in the mouse endometrium].

In order to explore the role of MNSFbeta in the process of implantaion, MNSFbeta and its antibodies are required. The expression plasmid pBV220/MNSFbeta-hCGbeta was constructed, and then transferred into E. coli to express the fusion protein MNSFbeta-hCGbeta. The anti-hCGbeta antibody was used to identify the fusion protein. The result demonstrated that MNSFbeta-hCGbeta was expressed correctly and its molecular weight was consistent with the anticipated one. Finally the expression product MNSFbeta-hCGbeta was preliminarily purified and used to immunize Balb/C mouse to generate the antibodies. In the meantime, the expression plasmid pGEX-4T-2/MNSFbeta was also constructed and transferred into E. coli to express the fusion protein GST-MNSFbeta. GST-MNSFbeta was purified and used to stimulate the immunized mouse before the preparation of hybridomas cells. The prepared polyclonal and monoclonal antibodies against MNSFbeta were checked and measured by fusion protein GST-MNSFbeta. The prepared polyclonal antibody was then used to perform the immunohistochemistry analysis. The result suggested that the level of MNSFbeta in interimplantation sites was significantly higher as compared with implantation sites in the mouse uterine on Day 4.5 of pregnancy.

Animals↗