Immunoneutralization of endometrial monoclonal nonspecific suppressor factor beta (MNSFbeta) inhibits mouse embryo implantation in vivo.

Successful embryo implantation and pregnancy in mammals depends on the establishment of immune tolerance between the maternal immune system and fetal cells. Monoclonal nonspecific suppressor factor beta (MNSFbeta), a cytokine produced by suppressor T cells in various tissues, possesses an antigen-nonspecific immune-suppressive function, and may be involved in the regulation of the uterine immune response during embryo implantation. In this study, anti-MNSFbeta IgG administered directly into the uterine lumen, significantly inhibited mouse embryo implantation in a dose-dependent manner in vivo, and this effect was reversed by co-administration of recombinant MNSFbeta. The effects of anti-MNSFbeta IgG on the gene pattern profiles in mouse uterine tissues were examined by cDNA microarray and several changes were confirmed by real-time PCR. Anti-MNSFbeta IgG caused up-regulation (> or = 2-fold) of 71 known genes and 17 unknown genes, and decreased expression (> or = 2-fold) of 74 known genes and 43 unknown genes, including several genes previously associated with embryo implantation or fetal development. Most of the known genes are involved in immune regulation, cell cycle/proliferation, cell differentiation/apoptosis, and lipid/glucose metabolism. These results demonstrate that MNSFbeta plays critical roles during the early pregnancy via multiple pathways.

[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.

[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.

[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.

[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.

Effect of chronic treatment of ohmefentanyl stereoisomers on cyclic AMP formation in Sf9 insect cells expressing human mu-opioid receptors.

The binding affinity of ohmefentanyl stereoisomers for mu-opioid receptors and the effect of chronic ohmefentanyl stereoisomers pretreatments on intracellular cAMP formation were investigated in Sf9 insect cells expressing human mu-opioid receptors (Sf9-mu cells). Competitive assay of [3H]ohmefentanyl binding revealed that these isomers had high affinity for micro-opioid receptors in Sf9-mu cells. Isomer F9204 had the highest affinity for mu-opioid receptors with the Ki value of 1.66 +/- 0.28 nM. After pretreated Sf9-mu cells with increasing concentrations of these isomers for 6 h, addition of naloxone (1 microM) precipitated an overshoot of foskolin-stimulated cAMP accumulation. The ability of these isomers to induce cAMP overshoot differed greatly with the order of F9202>F9205>F9208>F9206>F9204>F9207. Of these isomers, F9202 was 2.7-fold less potent than F9204 in receptor binding affinity, but 71.5-fold more potent in ability to induce cAMP overshoot. These results suggested that there was a significant stereo-structural difference among ohmefentanyl stereoisomers in ability to induce naloxone-precipitated cAMP overshoot in Sf9-mu cells.

Binding affinity to and dependence on some opioids in Sf9 insect cells expressing human mu-opioid receptor.

AIM: To investigate the receptor binding affinity and naloxone-precipitated cAMP overshoot of dihydroetorphine, fentanyl, heroin, and pethidine in Sf9 insect cells expressing human mu-opioid receptor (Sf9-mu cells). METHODS: Competitive binding assay of [3H]ohmefentanyl was used to reveal the affinity for mu-opioid receptor in Sf9-mu cells. [3H]cAMP RIA was used to determine cAMP level. Antinociceptive activity was evaluated using degree 55 mouse hot plate test. Naloxone-precipitated withdrawal jumping was used to reflect physical dependence in mice. RESULTS: All drugs displayed antinociceptive activity and produced physical dependence in mice. The K(i) values of dihydroetorphine, fentanyl, heroin, and pethidine in competitive binding assay were (0.85+/-0.20) nmol, (59.1+/-11.7) nmol, (0.36+/-0.13) micromol, and (12.2+/-3.8) micromol respectively. The binding affinities of these drugs for mu-opioid receptor in Sf9-mu cells were paralleled to their antinociceptive activities in mice. After chronic pretreatment with these drugs, naloxone induced cAMP withdrawal overshoot in Sf9-mu cells. The dependence index in Sf9-mu cells was calculated as K(i) value in competitive binding assay over EC(50) value in naloxone-precipitated cAMP assay. The physical dependence index in mice was calculated as antinociceptive ED(50)/withdrawal jumping cumulative ED(50). There was a good linear correlation between dependence index in Sf9-mu cells and physical dependence index in mice. CONCLUSION: The Sf9-mu cells could be used as a cell model to evaluate the receptor binding affinity and physical dependent liability of analgesic agents.

Expression of dopamine D1 receptor in Sf9 insect cells and agonism of l-12-chloroscoulerine on recombinant D1 receptor.

AIM: To express dopamine D1 receptor in baculovirus-Sf9 cell system, and to investigate the effects of l-12-chloroscoulerine (l-CSL) on the recombinant D1 receptor (D1R). METHODS: The recombinant baculovirus, Autographa californica nuclear polyhedrosis virus bearing D1R (AcNPV- D1R) was generated, and then was used to produce recombinant D1R in Sf9 insect cells. Expression of D1R in Sf9 cells was monitored by [3H]SCH23390 binding assay. The effects of l-CSL on recombinant D1R were investigated by [3H]SCH23390 binding assay and cAMP assay. RESULTS: The recombinant baculovirus AcNPV bearing D1R cDNA was generated, and was successfully expressed in Sf9 insect cells. The expression level of (Bmax) was (0.94+/-0.06) nmol/g protein. The Kd value of [3H]SCH23390 was (1.9+/-0.3) nmol/L, which was consistent with the previous results from calf striatum tissues. l-CSL had a high affinity to recombinant D1R with Ki value of (6.3+/-1.4) nmol/L, and increased the intracellular cAMP level in a concentration-dependent manner with EC50 value of 0.72 micromol/L and 95 % confidence limit was 0.67-0.77 micromol/L. Thus l-CSL has the D1 receptor agonism. CONCLUSION: An efficient baculovirus-Sf9 insect cell system for dopamine D1 receptor was constructed and l-CSL presented the D1 receptor agonism on cellular-molecular level directly.

[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.