PPARγ up-regulates TGFβ/smad signal pathway repressor c-Ski / 生理学报

TGFβ/smad pathway is recognized as an important signal pathway to promote the pathogenesis of atherosclerosis (AS). Peroxisome proliferator-activated receptor γ (PPARγ) activation is considered to be important in modulating AS. Herein, we investigated the regulation of PPARγ on c-Ski, the repressor of TGFβ/smad pathway, in rat AS model and cultured vascular smooth muscle cells (VSMCs). c-Ski mRNA and protein expression were detected by real-time PCR and Western blot, respectively, in vivo and in vitro with treatment of PPARγ agonist rosiglitazone and antagonist GW9662. The proliferation and collagen secretion of VSMCs after c-Ski transfection were investigated. The underlying mechanism was further investigated by online program NUBIScan and luciferase reporter gene analysis. Results showed that both mRNA and protein expressions of c-Ski in the AS lesions was down-regulated in vivo, while in cultured VSMCs, c-Ski transfection significantly suppressed the proliferation and collagen secretion of rat VSMCs. Rosiglitazone significantly up-regulated mRNA and protein levels of c-Ski in VSMCs, which could be blocked by GW9662. Online NUBIScan analysis suggested possible PPARγ binding sites in the promoter region of c-Ski. In addition, luciferase activity of c-Ski reporter gene was also increased obviously in the presence of rosiglitazone. These results indicate that c-Ski is one of the newly found target genes of PPARγ and thus involved in the anti-AS effect of PPARγ.

Effect of androsterone on scavenger receptor class B type I in human vascular endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of FXR on scavenger receptor class B type I (SR-BI) expression.</p><p><b>METHODS</b>Human vascular endothelium Eahy926 cells were treated with FXR agonist androsterone, and the specific target gene of FXR SHP mRNA was detected by RT-PCR. SR-BI mRNA and protein were determined using RT-PCR, real-time PCR and Western blotting.</p><p><b>RESULTS</b>The level of SHP mRNA in Eahy926 cells increased after androsterone treatment at different concentrations for 24 h, demonstrating FXR activation in the cells. RT-PCR, real-time PCR and Western blotting detected increased SR-BI expression at both mRNA and protein levels after FXR activation.</p><p><b>CONCLUSION</b>FXR increases the expression of SR-BI in human vascular endothelium cells.</p>

Expression and activity analysis of human 67kD laminin receptor in Pichia pastoris / 生物工程学报

To carry out the secretive expression of human 67 kD laminin receptor (67LR), recombinant expression plasmid pPIC9K-67LR was constructed by inserting of 67LR cDNA into yeast expression vector pPIC9K. The 67LR protein was expressed in Pichia pastoris after induced by methanol, and about 12.56 mg electrophoresis purity 67LR could be obtained after the purification of 1L culture using affinity chromatograph column. In vitro competitive binding assay showed that target protein has an excellent biological activity. The successful expression of 67LR has placed a solid foundation for the research on structure and functions of 67LR.

Expression of human LNalpha4LG4-5 in Pichia yeast / 生物工程学报

To carry out the secretive expression of human laminin alpha4 chain LG4-5 module (hLNalpha4LG4-5), recombinant expression plasmid pPICZalphaA-LG45 was constructed by inserting of hLNalpha4LG4-5 cDNA into yeast expression vector pPICZaA. The hLNalpha4LG4-5 protein was expressed in GS115 Pichia yeast strain after induced by methanol, and purified target protein can obviously promote the expansion and adhesion of 293 cells.

The cloning, high level expression in Escherichia coli of human beta-defensin 3 and its antimicrobial activity analysis / 生物工程学报

In recent years, Bacterial resistance is more and more serious for the irrational use of antibiotics produces resistant strains and other reasons. Human are trying to solve the problem from different ways, including the study of antimicrobial peptides. Defensin is one of the most important of antimicrobial peptides. A novel antimicrobial peptide, human beta-defensin 3, was isolated and demonstrated a salt-insensitive broad spectrum of potent antimicrobial activity against many potentially pathogenic microbes. The total RNA was extracted from human tonsil and the hbetaD-3 specific cDNA sequence was amplified with RT-PCR. After sequenced, the target DNA fragment was cloned into pQE-80L vector together with the DNA fragment encoding carrier protein DHFR. The recombinant vectors were transformed into E. coli M15 and the expression was induced based on the optimal values of the IPTG concentration incubation temperature and induction time determined in the previous section. The expressed proteins were analyzed by SDS-PAGE and Western-blotting. The mass of the recombinant protein was about 40% of total bacteria protein. Isolate and purify the target protein. The recombinant hbetaD-3 fusion proteins possess the antimicrobial activity to staphylococcus aureus, multiresistant staphylococcus aureus (only vancomycin-sensitive) and Candida albicans in the assay of drug susceptibility. Advanced study can be continued based on our experiments.

Generation of antiidiotypic antibody to monoclonal antibody MGd1 directed against gastric carcinoma by phage antibody library technique / 第三军医大学学报

Objective To pave the way for developing recombinant antiidiotypic antibody(antiId)vaccine of gastric carcinoma by generating phagedisplayed antiId to monoclonal antibody MGd1 directed against the cancer. Methods Balb/c mice were immunized i.p. with MGd1 conjugated with KLH, and mRNA was isolated from the spleens of the immunized mice. VH and VL DNAs of the antibody were amplified separately by RTPCR and assembled into ScFv DNAs with a linker DNA by PCR. The ScFv DNAs were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E.coli TG1. The transformed cells were infected with M13KO7 helper phage to yield phage antibody ScFv library. After four rounds of panning to the library with MGd1, the MGd1positive clones were selected by ELISA from the enriched phages. The types of the antiId ScFv displayed on the selected phage clones were preliminary identified by competition ELISA. Results The VH,VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. After four rounds of panning to the antibody library, 17 MGd1positive phage clones displayed antiId ScFv were selected from 40 enriched phage clones, among which 3 displayed ? or ? type antiId ScFv. Conclusion The successful generation of antiId ScFv to monoclonal antibody MGd1 by recombinant phage antibody library technology might lay a foundation for screening of novel candidate molecules for developing recombinant antiId vaccine of gastric carcinoma.

Expression of the immune inhibitors of human B cell activating factor belonging to the tumor necrosis factor family and evaluation of immune response in vaccinated mice / 中华风湿病学杂志

Objective To prepare T-helper cell(Th)epitnpe-modified human soluble B cell activating factor belonging to the tumor necrosis factor family(BAFF)mutants and evaluate their immune response in vaccinated mice.Methods Recombinant cDNAs were cloned and ligated into the prokaryotie expression vec- tor pQE-80L respectively.The recombinant proteins were induced to express by IPTG in E.coli DH5?and purified with Ni-NTA chromatography.BALB/c mice were immunized with recombinant proteins respectively and the titres of the antibodies that were cross-reactive with BAFF in sera were analyzed by ELISA.Inhibiting ability of the antibodies in sera was analyzed by MTT assay.Results The recombinant proteins were highly expressed in E.coli DH5?.After purification,the purity of recombinant proteins was more than 90%.BALB/c mice immunized with recombinant proteins produced high levels of BAFF-specific antibodies.Cell proliferation assay showed that the sera of immunized mice could inhibit the proliferation-inducing activity of recombinant sBAFF and natural sBAFF.Conclusion The immune inhibitors of human BAFF which can induce polyclonal antibodies that are cross-reactive with BAFF are successfully prepared.These results may provide the basis for further study of their therapeutic effects.