Effect of danshensu on activation of JNK pathway in hepatic stellate cells(HSCs) induced by IL-1 beta / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To investigate the inhibitory effect of danshensu on the activation of JNK signaling in rat hepatic stellate cells (HSCs) induced by IL-1beta.</p><p><b>METHODS</b>The proliferation of primary rat HSCs treated with different concentration of Danshensu was checked by MTT colorimetric assay. The expression and phosphorylation of JNK and P-JNK was detected by western blotting. Synthesis and secretion of collagen I were detected by the quantitative immunocytochemical assay and ELISA.</p><p><b>RESULTS</b>Danshensu inhibited the proliferation of HSCs in a dose-dependent manner. At the concentration of 0.0625 to 0.25 mmol/L, Danshensu significantly repressed the proliferation of HSC induced by IL-1beta (P < 0.05). Synthesis and secretion of Type I collagen was significantly decreased 24 hours after 0.25 mmol/L Danshensu treatment (P < 0.01). The phosphorylation of JNK induced by IL-1beta was significantly inhibited by Danshensu treatment (P < 0.05), however, the expression of JNK was not regulated by Danshensu.</p><p><b>CONCLUSION</b>Danshensu represses the activation and proliferation of HSCs, and inhibits the synthesis and secretion of Type I collagen, possibly via the repression of the JNK signal transduction.</p>

Construction of a eukaryotic expression vector of the gene encoding rat interferon-gamma-inducible protein and its expression in NIH 3T3 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct an expression vector of the gene encoding rat interferon-gamma-inducible protein (IP-10) and identify its expression in NIH 3T3 cells.</p><p><b>METHODS</b>IP-10 gene was amplified by polymerase chain reaction (PCR) and inserted into the eukaryotic expression vector pcDNA3.1(+). After identification by PCR, restriction endonuclease digestion and sequence analysis, the recombinant expression vector pcDNA3.1(+)-IP-10 was transfected into NIH 3T3 cells via liposome. Immunofluorescence method was used to confirm the expression of pcDNA3.1(+)-IP-10 in the transfected NIH 3T3 cells. The expression of IP-10 protein in the supernatant of the transfected cells was examined by Western blotting.</p><p><b>RESULTS</b>PCR, restriction endonuclease digestion and sequence analyses confirmed successful construction of the recombinant vector pcDNA3.1(+)-IP-10. Immunofluorescence assay identified the expression of pcDNA3.1(+)-IP-10 in NIH 3T3 cells, and the expression of IP-10 protein was detected by Western blotting in the supernatant of the transfected cells.</p><p><b>CONCLUSION</b>A eukaryotic expression vector pcDNA3.1(+)-IP-10 has been successfully constructed, which provides the basis for investigating the therapeutic effect of IP-10 on Th1 type autoimmune disease.</p>

Cloning of ureI gene from Helicobacter pylori and its expression in E. coli / 南方医科大学学报

<p><b>OBJECTIVE</b>To clone the urea membrane channel gene (ureI) from Helicobacter pylori (Hp) for its expression in E. coli, and evaluate the expression conditions and immunological features of the fusion protein.</p><p><b>METHODS</b>ureI gene cloned by PCR from Hp was inserted into the plasmid pET32a (+) to construct the recombinant plasmid pET32a/ureI, followed by identification by BglII and HindIII digestion and sequencing. E. coli BL-21+(DE3) was transformed with pET32a/ureI to obtain the engineered bacterium BL21+/UreI, which was cultured at different temperatures and induced with 1.0 mmol/L IPTG for expression of the recombinant protein. The expressed proteins were identified by SDS-PAGE and analyzed by Pro-gel analyzer 4.0. Western blotting was performed to evaluate the immunogenicity of the expressed protein.</p><p><b>RESULTS</b>The cloned gene fragment was about 650 bp in length, and BglII and HindIII digestion of pET32a/ureI yielded a 650-bp band. Sequence analysis revealed that the cloned ureI gene contained 646 bp without reading frame alterations. Comparison against GenBank indicated a homology of 100% of the cloned gene with ureI gene of the corresponding Hp strains, and also one no less than 98.5% with ureI gene from other strains. The engineered E. coli BL21+/UreI could express recombinant UreI (rUreI) with His tag, and the target protein accounted for 20.2% of the total bacterial proteins after 1.0 mmol/L IPTG induction of the bacterium at 37 degrees C for 14 h. SDS-PAGE and Western blotting showed that the recombinant UreI protein was produced mainly in the inclusion bodies and fused with his-tag (rUreI/his), which could react with human anti-Hp and mAb to his tag but not with mAb to Hp UreB.</p><p><b>CONCLUSIONS</b>We have successfully cloned ureI gene and constructed the prokaryotic expression plasmid for efficient rUreI expression, and the fusion protein rUreI/his expressed in the inclusion bodies can react specifically with both Hp antibody and his-tag antibody.</p>

ST6Gal I siRNA and antisense oligonucleotide-mediated gene silencing lowers the invasiveness potential of colonic carcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of small interfering RNA (siRNA) and antisense oligonucleotides (ASOs) targeting ST6Gal I on adhesion and invasiveness of human colonic carcinoma cell line SW480 over-expressing ST6Gal I.</p><p><b>METHODS</b>siRNA and ASOs targeting ST6Gal I were constructed and transfected into SW480 cells via lipofectmine 2000. SW480 cells were cultured and divided into 7 groups, namely the blank control group, liposome group, siRNA group (transfected with ST6Gal I siRNA), ASO(1) group (transfected with ST6Gal I ASO whose target site is different from the siRNA), ASO(2) group (transfected with ST6Gal I ASO targeting the same site as siRNA), siRNA+ASO(1) group (transfected with siRNA and ASO(1)), siRNA+ASO(2) group (transfected with siRNA and ASO(2)). RT-PCR was used to examine ST6Gal I mRNA expression following the treatment. Flow cytometry was used to examine the amount of alpha2,6-sialylation on SW480 cell surface. SW480 cell adhesion and invasiveness to the extracellular matrix (ECM) were analyzed using CytoMatrix kit and cell invasion assay kit, respectively.</p><p><b>RESULTS</b>The expression of ST6Gal I mRNA, the amount of alpha2,6-sialylation on the cell surface and cell adhesion and invasion to ECM decreased remarkably in groups siRNA, ASO(1), ASO(2), siRNA+ASO(1) and siRNA+ASO(2), all significantly lower than those of the blank control and liposome groups (all P<0.05), especially in siRNA+ASO(1) group. Significant difference was noted between siRNA+ASO(1) and siRNA groups (P<0.05), but not between siRNA+ASO(2) and siRNA groups, or between blank control and liposome groups (all P>0.05).</p><p><b>CONCLUSION</b>Chemically synthesized specific siRNA targeting ST6Gal I effectively inhibits SW480 cell ST6Gal I expression and leads to diminished cell adhesion and invasiveness to ECM, suggesting a combined effect of siRNA and ASO with different targeting sites.</p>

Optimized isolation and purification of non-typeable Haemophilus influenzae Haps protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To optimize the isolation and purification conditions for Hap(s) protein of non-typeable Haemophilus influenzae.</p><p><b>METHODS</b>Hap(s) protein was purified by ammonium sulfate precipitation, dialysis desalting and Hitrap weak cation exchange columns of CM Sepharose Fast Flow. The condition of the elution was optimized for pH and ionic strength, the absorbance at 280 nm of the elution samples were detected, and the targeted protein band in the collected samples was observed by SDS-PAGE electrophoresis.</p><p><b>RESULTS</b>The Hitrap ion exchange column was eluted with buffer 1, which resulted in a baseline distribution of absorbance at 280 nm. Buffer 2 elution of the column resulted in the presence of peak absorbance with trails, which was identified to be constituted by some low molecular weight bands by subsequent SDS-PAGE. In serial column elution with buffer 3 with different ionic strength, a peak absorbance was observed with the ionic strength of 100 mmol/L NaCl, and SDS-PAGE confirmed that the peak was generated by the target protein. No obvious peaks or bands in SDS-PAGE occurred with the other ionic strengths.</p><p><b>CONCLUSION</b>The pH of the buffer only affect the elution of the irrelevant proteins rather than the Hap(s) protein, and elution with the buffer containing 100 mmol/L NaCl can be optimal for eluting the Hap(s) protein.</p>

Effects of ST6Gal I antisense oligonucleotide-mediated gene silencing on cell adhesion and invasiveness of hela cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effects of antisense oligonucleotide (ASODN) targeting ST6Gal I on cell adhesion and invasiveness of human cervical carcinoma cell line HeLa which over-expressed ST6Gal I .</p><p><b>METHODS</b>ASODN and sense oligonucleotide (SODN) targeting ST6Gal I were designed and constructed, and transfected into a cervical cancer cell line, HeLa, by lipofectmine 2000. HeLa cells were cultured and divided into 4 groups: blank control group, liposome group, SODN group and ASODN group. RT-PCR was used to examine the ST6Gal I mRNA expression. Flow cytometry was used to examine the amount of alpha2, 6-sialylation on the HeLa cell surface. The HeLa cell adhesion and invasiveness to extracellular matrix ( ECM) were analyzed by using CytoMatrixTM kit and cell invasion assay kit, respectively.</p><p><b>RESULTS</b>The expression of ST6Gal I mRNA in HeLa cells at 48 hrs after transfection in the ASODN group was significantly decreased in comparison with that in the blank control group, liposome group, and SODN group(P <0. 01). The amount of alpha2,6-sialylation on cell surface in ASODN group was significantly lower than that of the other 3 groups ( P <0. 05). The adhesion and invasiveness of the cells in the ASODN group decreased remarkably, both significantly lower than those of the other 3 groups ( all P < 0. 05).</p><p><b>CONCLUSION</b>Specific ASODN targeting ST6Gal I effectively inhibits HeLa cell ST6Gal I expression, decreases the amount of alpha2,6-sialylation on cell surface and leads to a decline of cell adhesion and invasiveness to ECM. This result also established a fine base for further studying on anti-tumor treatment with antisense oligonucleotide.</p>

Therapeutic effect of a new recombinant immunotoxin mMIP-1alpha-DT390 on experimental autoimmune encephalomyelitis / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the therapeutic effect of a new recombinant immunotoxin mMIP-1alpha-DT390 on experimental autoimmune encephalomyelitis (EAE).</p><p><b>METHODS</b>EAE was induced in the low-sensitive strain C57BL/6 mice with intraperitoneal injection of myelin basic protein (MBP) to simulate the human disease multiple sclerosis, followed by intramuscular injection of cationic liposome carrying the plasmid DNA SRalpha-mMIP-1alpha-DT390 in the leg muscle to elicit resistance to EAE development. The mice were then examined daily for clinical signs of EAE by an observer blind to the treatment protocol. For immunohistochemistry the mice were anesthetized and perfused with sterile PBS and paraformaldehyde, and the cerebrum, cerebellum, medulla and spinal cord were removed for preparation of serial sections. The mononuclear cells (MNCs) from the EAE mouse spleens were prepared for three-color flow cytometry analysis of the surface markers with appropriate antibodies following the BD Pharmingen cytokine staining protocol.</p><p><b>RESULTS</b>EAE model was successfully established by active MBP immunization in C57BL/6 mice. Administration of the immunotoxin mMIP-1alpha-DT390 significantly delayed the disease onset and lowered the mean clinical score for EAE as compared with the control mice. Immunohistochemistry demonstrated much less CCR5(+) infiltrating cells in the central nervous system in mMIP-1alpha-DT390-treated mice than in the control. The treatment also eliminated reactive T cells in the periphery blood without affecting the number of B cells.</p><p><b>CONCLUSION</b>The immunotoxin mMIP-1alpha-DT390 can attenuate the disease activity of EAE in mice, suggesting its potential use in the treatment of other autoimmune disorders.</p>

Prokaryotic expression and identification of human papillomavirus type 16 E5 protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct the prokaryotic and eukaryotic expression vectors pET32/E5 and pcDNA3.1/E5 for transformation into E. coli BL21 and NIH(3)T(3) cells respectively to observe the expression of human papillomavirus type 16 E5 protein (HPV16 E5).</p><p><b>METHODS</b>HPV16 E5 gene was amplified by PCR from clinical isolates of HPV 16 and inserted into the plasmid pET32a(+) followed by digestion with BamH I and Hind III. The recombinant plasmid pET32/E5 was transformed into E. coli JM109 and selected with ampicillin. The positive clones containing the recombinant plasmid pET32/E5 were verified by restriction endonucleases BamH I and Xho and sequence analysis. The expression of HPV16 E5-TRX fusion protein in E. coli BL21(ED3) was identified by SDS-PAGE and Western blotting. The digestion product of BamH I and Xho was purified and inserted into the eukaryotic expression vector pcDNA3.1(+) to construct pcDNA3.1/E5, which was identified by sequencing and transfected into NIH3T3 cells. The NIH(3)T(3) cells with stable expression of HPV16 E5 were selected by G418 and confirmed by RT-PCR.</p><p><b>RESULTS</b>The pET32/E5 and pcDNA3.1/E5 vectors were constructed successfully. E.coli BL21(DE3) transformed by the recombinant plasmid pET32/E5 expressed HPV16 E5-TRX fusion protein efficiently. In the presence of 1 mmol/L IPTG at 28 degrees C, HPV16 E5-TRX recombinant protein accounted for about 10% of the total bacterial proteins. NIH3T3 cells stably expressing HPV16 E5 were harvested by selection with 250 g/ml of G418. HPV16 E5 gene from pcDNA3.1/E5-transfected NIH(3)T(3) cells was amplified by RT-PCR, and sequence analysis demonstrated the acquisition of the full-length gene fragment.</p><p><b>CONCLUSIONS</b>The prokaryotic and eukaryotic vectors for the HPV16 E5 gene have been successfully constructed. The acquisition of E .coli and NIH(3)T(3) cells with stable expression of HPV16 E5 protein may facilitate subsequent research of the biological properties and the transformation mechanism of HPV16 E5 protein on specific cells.</p>

Purification of Recombinant Fusion Protein Staphylokinase-Hirudin Expressed by Escherichia coli and Analysis of its Dimer / 中国生物工程杂志

The recombinant fusion protein staphylokinase-hirudin(rSFH) was purified from the high density-fermented engineered E.coli by means of ion-exchange chromatography (IEC) and gel filtration (GF). The purity of rSFH reached to more than 98% determined by RP-HPLC and SDS-PAGE, and the yield was up to 0.7g per liter of fermentation broth. The analysis of homologous dimmer of rSFH appeared during the purification and calculation of the surface hydrophobic area had been carried out by means of hydrophobic chromatography and MALD-TOF. The influence of sodium chloride and temperature on the behavior of rSFH reversible dimerization was analyzed by high performance sized- exclusive chromatography(HPSEC). It is concluded that the hydrophobic interaction played an important role in the reversible dimerization of rSFH.

Construction and expression of a fusion protein made of tissue-type plasminogen activator and hirudin in Pichia pastoris / 生物工程学报

To combine the fibrinolytic with anticoagulant activities for therapy of thrombotic deseases, a fusion protein made of tissue-type plasminogen activator (t-PA) and hirudin was constructed and expressed in chia pastoris. To improve thrombolytic properties of t-PA and reduce bleeding side effect of hirudin, FXa-recognition sequence was introduced between t-PA and hirudin molecules.The anticoagulant activity of hirudin can be target-released through cleavage of FXa at thrombus site. t-PA gene and hirudin gene with FXa-recognition sequence at its 5'-terminal were obtained by RT-PCR and PCR respectively. The fusion protein gene was cloned into plasmid pIC9K and electroporated into the genome of Pichia pastoris GS115. The expression of fusion protein was induced by methanol in shaking flask and secreted into the culture medium. Two forms of the fusion protein, single-chain and double-chain linked by a disulfide bond (due to the cleveage of t-PA at Arg275-Ile276), were obtained. The intact fusion protein retained the fibrinolytic activity but lacked any anticoagulant activity. After cleavage by FXa, the fusion protein liberated intact free hirudin to exert its anticoagulant activity. So, the fusion protein is a bifunctional molecule having good prospect to develop into a new targeted therapeutic agent with reduced bleeding side effect for thrombotic diseases.