[The Establishment and Identification of Stable CHO Cell Line with Canine Transferrin Receptor Expression].

OBJECTIVES: To construct eukaryotic expressing recombinant vector of canine transferrin receptor gene (TfR ), then to transfect Chinese hamster ovary (CHO) cells with the vector for establishment of stable expression of TfR in CHO cell line. METHODS: The full-length TfR fragment was amplified by RT-PCR from the canine cells (walter reed dog cell, WRD) and then inserted into eukaryotic expression vector pCDNA3. After identification with enzyme digestion and sequencing, the recombinant vector was transfected into CHO cells by TransLipid Transfection Reagent. The stable transfected CHO cell line was then established by screening cultures with G418, and the expression of TfR was identified by RT-PCR, Western blot and immunofluorescence, respectively. RESULTS: The eukaryotic expression vector pCDNA3-TfR was constructed successfully by checking with enzyme digestion and sequencing, and the highly expressed canine TfR was observed in CHO cells transfected with pCDNA3-TfR by using RT-PCR, Western blot and immunofluorescence, respectively. The stable CHO cell line with canine TfR expression was established. CONCLUSIONS: The construction of the eukaryotic expression vector pCDNA3-TfR and the establishment of stable CHO cell line with TfR expression provide solid foundation for further experimental studies on the function of TfR.

Construction and expression of human scFv-Fc against interleukin-33.

Interleukin-33 (IL-33) is a member of the IL-1 family and the ligand of orphan ST2 molecules. IL-33 is widely expressed in multiple tissues and cells, and mainly involved in regulating Th2 immune and inflammatory responses. Inhibiting IL-33 signaling pathways relieves the symptoms of allergic inflammation, indicating that IL-33 is a potential target for the treatment of allergic diseases. In this study, the recombinant vectors SP-scFv-Fc/pcDNA3.1 and SP-scFv-Fc/PMH3(EN) were constructed to express a human scFv-Fcs against IL-33. The size of the inserted SP-scFv-Fc was approximately 1540bp. The RT-PCR results showed that SP-scFv-Fcs were successfully transfected into CHO K1 cells. Western blot analysis indicated specific binding of the expressed scFv-Fcs fusion protein (approximately 60kDa under reduced condition) with a goat anti-human IgG1 Fc antibody. The expression level of the scFv-Fcs from SP-scFv-Fc/PMH3(EN) was higher than that from SP-scFv-Fc/pcDNA3.1. A single high-expressing cell line was selected after three rounds of screening and the fusion protein was expressed in a suspension culture in serum-free medium. The level of expression products reached 20mg/L and the expressed and purified scFvs was further characterized and analyzed for bioactivity and functionality. The recombinant vectors for eukaryotic expression of scFv-Fcs against IL-33 were successfully constructed and the expressed scFv-Fcs was shown to be a suitable candidate for the development of a new therapy for allergic and autoimmune diseases.

Construction of PR domain eukaryotic expression vector and its inhibitory effect on esophageal cancer cells.

OBJECTIVE: PR domain is responsible for the tumor suppressing activity of RIZ1. The study aimed to construct human PR domain eukaryotic expression vectors, transfect human esophageal cancer cells (TE13), and evaluate the anticancer activity of PR domain on human esophageal cancer TE13 cells. METHODS: First, mRNA was extracted from human esophageal cancer tissue by RT-PCR, then reverse-transcribed to cDNA. After amplifying from the DNA template, PR domain was linked to T vector. Second, after extraction, PR domain was cut using enzyme and linked to pcDNA3.1(+). Then, the plasmid was transfered to Trans1-T1 phage resistant competent cells, following by extracting the ultrapure plasmid, and transfecting into TE13 cells. In the end, the protein expression of pcDNA3.1(+)/PR domain in TE13 was detected by Western blot, and the apoptosis of TE13 by technique of flow cytometry. RESULTS: More than 5,000 bp purposed band of pcDNA3.1(+)/PR domain plasmid was found by agarose gel electrophoresis. After transfection, the PR domain (molecular weight of about 28 Da) was found only in 3, 4 and 5 groups by Western blot. Flow cytometry assay showed apoptosis in experimental group was significantly more than that in the control group (P<0.05). CONCLUSIONS: The PR domain eukaryotic expression vector was constructed successfully. The protein of the PR domain could be expressed in esophageal cancer TE13 cells firmly after transfection, and a single PR domain could promote apoptosis of TE13 cells.

Expression and Purification of a PEDV-Neutralizing Antibody and Its Functional Verification.

Porcine epidemic diarrhea virus (PEDV) is a highly infectious and pathogenic virus causing high morbidity and mortality, especially in newborn piglets. There remain problems with contemporary PEDV vaccines, in part because of the rapid variation of PEDV, poor conferred immunity, and numerous side effects. The ability to produce PEDV-neutralizing antibodies suggests that we may be able to increase the success rate of PEDV prevention in piglets using these antibodies. In this study, we produced an anti-PEDV S protein monoclonal antibody (anti-PEDV mAb-2) that neutralized PEDV-CV777 (a G1 strain), PEDV-SDSX16 and PEDV-Aj1102 (two G2 strains). In vivo challenge experiments demonstrated that anti-PEDV mAb-2 inhibited the PEDV infection in piglets. We also produced three HEK293 cell lines that expressed anti-PEDV mAb-2. Overall, our study showed that anti-PEDV mAb-2 produced from hybridoma supernatants effectively inhibited PEDV infection in piglets, and the recombinant HEK293 cell lines expressed anti-PEDV mAb-2 genes.

Production of Zika Virus Virus-Like Particles.

Zika virus (ZIKV) is a mosquito-transmitted virus that has caused major outbreaks of disease around the world over the last few years. The infectious ZIKV consists of a structural protein outer shell surrounding a nucleocapsid. Virus-like particles (VLP) consist of the outer structural protein shell, but without the nucleocapsid, and are hence noninfectious. VLP, however, are structurally equivalent to the native virus and thus present a similar antigenic profile. These properties make them good candidates for vaccine development. ZIKV VLP can be generated on a laboratory scale by cloning the relevant structural proteins into a eukaryotic expression vector and transfecting the construct into mammalian cells. The secreted VLP can be harvested from the culture medium and purified by sucrose cushion ultracentrifugation. Validation of the VLP is achieved through western blotting and electron microscopy.

Effects of melanoma differentiation associated gene-7 (MDA-7/IL-24) on apoptosis of liver cancer cells via regulating the expression of B-cell lymphoma-2.

The present study investigated the mechanism of selective killing of liver cancer cells of melanoma differentiation associated gene-7 (MDA-7, also called IL-24α) in order to provide a theoretical basis for gene therapy of liver cancer. A recombinant eukaryotic expression vector (pcDNA3-MDA-7) containing human MDA-7 gene was constructed, which was then delivered to liver cancer cell line HepG2 and normal liver cell line L02. The positive cell clone was screened by G418. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was performed to confirm the occurrence of MDA-7 transcription in the transfected cells. The protein expression of MDA-7 was determined by western blot analysis. The effects of MDA-7 on liver cancer cell proliferation and apoptosis were investigated through MTT assay and flow cytometry by Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double-staining. The mitochondrial protein was extracted from the normal liver cell line L02 and liver cancer cell line HepG2 at 3 day post-culture, in which the alterations of anti-apoptotic B-cell lymphoma-2 (Bcl-2), pro-apoptotic Bcl-2 associated X protein (Bax), mitochondria-released cytochrome c and caspase 9 were determined by western blot analysis. pcDNA3-MDA-7 mediated the expression of foreign gene MDA-7 in HepG2 and L02 cells. MDA-7 promoted liver cancer cell apoptosis and inhibited cell proliferation; while no effect was exerted on normal liver cells, as determined by the MTT assay and flow cytometry. Relative to the L02 cells, the protein expression of Bcl-2 was downregulated in the HepG2 cells, while that of Bax, cytochrome c and caspase 9 were upregulated. In the study, the eukaryotic expression vector pcDNA3-MDA-7 was successfully constructed, it can mediate the expression of MDA-7 in human liver cancer cells and normal liver cells and inhibits the proliferation of human liver cancer cells through the restored expression of mitochondrial pro-apoptotic Bcl-2.

Influence of NDR1 on prognosis of patients with hepatocellular carcinoma and effect on proliferation and migration of hepatocellular carcinoma cells / 安徽医科大学学报

Objective@#To analyze the expression and clinical prognostic significance of nuclear Dbf2-related kinase 1 ( NDR1 ) in hepatocellular carcinoma ，and to investigate the biological function and regulatory mechanism of NDR1 in hepatocellular carcinoma cells．@*Methods@#ENCORI database was used to analyze the correlation of NDR1 and c-Myc．Cycloheximide ( CHX) experiment analyzed the relationship between NDR1 and c-Myc protein stability．The expression levels of NDR1 in liver cancer tissues and normal tissues and its relationship with the survival rate of liver cancer patients were analyzed using the ENCORI database．MYC-NDR1 eukaryotic expression vector was constructed，transfected with hepatocellular carcinoma HepG2 cells，and its expression was verified by protein immuno blotting (Western blot) ; cell proliferation and migration ability were detected by CCK-8 assay，cell clone formation assay and scratch assay，respectively．The correlation between NDR1 and c-Myc expression was analyzed using the ENCORI database，and the relationship between NDR1 and c-Myc protein was investigated using a protein synthesis inhibitor CHX dosing assay. @*Results@#The results of the ENCORI database showed that the expression of NDR1 in liver cancer tissues was higher than that in normal tissues and the overall survival rate of patients with high NDR1 expression was lower than that of patients with low NDR1 expression，and the difference was statistically significant (P＜0. 001) ．The results of the CCK-8 assay showed that the MYC-NDR1 group grew faster than the empty vector group (P＜0. 001) ．The clone formation assay showed that the number of clones in the MYC-NDR1 group was higher than that in the empty vector group (P＜0. 001) ．The cell scratch assay showed that the mean migration distance in the MYC-NDR1 group was greater than that in the empty vector group (P＜0. 001) ．ENCORI database analysis showed that NDR1 correlated with c-Myc expression (R = 0. 184，P＜0. 001) ; CHX dosing assay showed that the reduction of c-Myc protein in the MYC-NDR1 group was lower than that in the empty vector group during the same time．@*Conclusion@#NDR1 is highly expressed in hepatocellular carcinoma tissues，closely correlated with poor prognosis of hepatocellular carcinoma patients ，and positively correlated with the expression of c-Myc gene. The study successfully constructes MYC-NDR1 eukaryotic expression vector ，and the expression product MYC- NDR1 can increase the stability of c-Myc protein and promote the proliferation and migration of human hepatocellu- lar carcinoma cells.

Effect of SLC34A2 gene mutation on extracellular phosphorus transport in PAM alveolar epithelial cells.

A mutation in the IIb sodium phosphate transporter SLC34A2 gene has recently been described in pulmonary alveolar microlithiasis (PAM) patients. Experiments in this study were aimed at confirming the role of the gene product in PAM by comparing phosphorylated products in extracellular fluid of alveolar epithelial cells overexpressing the SLC34A2 gene or its mutated version. Eukaryotic expression vectors were constructed and transfected into A549 human alveolar epithelial cells. There were three groups of cells including those transfected with empty vector plasmid pcDNA3.1(+) (plasmid control group), those transfected with normal SLC34A2 gene expressed from pcDNA3.1 (normal control group), and those transfected with a version of the PAM SLC34A2 gene linked to the pcDNA3.1(+) (PAM group). Transfection efficiencies were detected by reverse transcription-polymerase chain reaction (RT-PCR). At 48 h after transfection, the concentration of inorganic phosphorus in the culture medium was detected using an automatic biochemical analyzer. Our results showed the concentration of inorganic phosphorus in the supernatant of the normal control group was significantly lower than that in the plasmid control and PAM groups (P<0.01), and the concentration in the PAM group was significantly lower than that in the plasmid control group (P<0.01). Based on our findings it is possible that the SLC34A2 gene mutation is the cause of the pathogenic changes observed in PAM patients, given that the function of the phosphate transporter seems to be affected and it is conceivable that it would lead to extracellular fluid alterations in vivo.

[Eukaryotic expression of human NOVA1 protein and identification of its anti-hypoxia activity].

The aim of this study was to construct the eukaryotic expression vector of pCMV-Myc-NOVA1 based on NOVA1 gene, and to screen the optimum expression condition after transfecting to PC12 cells, and further to explore the distribution of NOVA1 protein in PC12 cells using cell immunohistochemistry, and to identifyits anti-hypoxia activity. According to the NOVA1 gene sequence of NCBI database, we designed the upstream and downstream primers, and performed polymerase chain reaction (PCR) to amplify the full length cDNA coding sequence using pCR4-TOPO-NOVA1 as a template. The products were digested by restriction endonuclease SalⅠand XhoⅠ, and conjugated to the eukaryotic expression vector ofpCMV-Myc followed by validating by digestion and direct sequencing. Subsequently, the validated pCMV-Myc-NOVA1 was transfected to PC12 cells followed by optimizing of transfection ratio and transfection time, and identified by qPCR, Western blotting and cell immunohistochemistry respectively. After validation by digestion and direct sequencing, the eukaryotic expression vector of pCMV-Myc-NOVA1 was correctly constructed. The optimum transfection ratio of plasmid to Lipo 2000 was 1:2.5, and the optimum transfection time was 72 h. At the optimum transfection condition, the expression level of NOVA1 mRNA and protein significantly increased, and after transfection of pCMV-Myc-NOVA1, NOVA1 protein mainly distributed in cell nucleus and cytoplasm. After 6 h hypoxia, the cell proliferation activity was significantly increased compared to that of the control and pCMV-Myc group. Our findings provided a reference for exploring the mechanism of NOVA1, and also a technical support for potential drug development of NOVA1.

Construction of recombinant pEGFP-N1-hPer2 plasmid and its expression in osteosarcoma cells.

The aim of this study was to construct the eukaryotic expression vector pEGFP-N1-hPer2 and assess its expression in the human osteosarcoma cell line MG63. Total mRNA was extracted from human osteosarcoma MG63 cells, the human period 2 (hPer2) gene was obtained by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into the pEGFP-N1 vector, then the recombinant pEGFP-N1-hPer2 plasmid was constructed and transfected into MG63 cells using Lipofectamine 2000. The expression of hPer2 in MG63 cells was measured by quantitative RT-PCR and western blot analysis. The accurate construction of pEGFP-N1-hPer2 was verified by double enzyme digestion and DNA sequencing. hPer2 gene expression in the transfected cells was assessed by RT-qPCR and western blot analysis. In conclusion, the recombinant pEGFP-N1-hPer2 plasmid was constructed successfully, and expressed effectively in MG63 cells.

MicroRNA-126 Overexpression Inhibits Proliferation and Invasion in Osteosarcoma Cells.

This study investigated the biological effects of microRNA-126 overexpression in human MG63 osteosarcoma cells. A recombinant plasmid expressing microRNA-126, pcDNA6.2-microRNA-126, was constructed and transfected into MG63 cells. Using real-time fluorogenic quantitative polymerase chain reaction, the microRNA-126 expression was measured in microRNA-126-MG63 group, Ctrl-MG63 group, and blank group. Cell proliferation, cell cycle distribution, cell migration, and invasion were analyzed using methyl thiazolyl tetrazolium assay, flow cytometer, wound-healing assay, and transwell assay, respectively. As expected, microRNA-126 expression was higher in microRNA-126-MG63 group than in Ctrl-MG63 group and blank group (both P < .05). After 48/72 hours of transfection, cell proliferation in microRNA-126-MG63 group was significantly reduced compared to blank group (both P < .05). Compared to blank group, cell population in G0/G1 stage was significantly higher in microRNA-126-MG63 group, accompanied by lower cell numbers in the S and G2/M phases and decreased proliferation index (all P < .05). Wound-healing assay showed a wider scratch width in microRNA-126-MG63 group and reduced cell migration than blank group (both P < .05). Cells overexpressing microRNA-126 exhibited reduced ADAM9 expression levels compared to other 2 groups (all P < .05), suggesting ADAM9 is a target of microRNA-126. Cell proliferation, migration, and invasion rates were reduced in microRNA-126 group after 48/72 hours of transfection, compared with blank group (all P < .05). Cotransfection of pcDNA6.2-microRNA-126 and pMIR-ADAM9 into MG63 cells led to higher cell proliferation, invasion, and migration rates, compared with transfection of pcDNA6.2-microRNA-126 alone (all P < .05). In summary, our data show that microRNA-126 inhibits cell proliferation, migration, and invasion in human osteosarcoma cells by targeting ADAM9.

DNA Damage-Inducible Transcript 4 (Ddit4) Overexpression Could Inhibit Proliferation and Promote Apoptosis of HT-22 Cells through the Wnt / β-catenin Signaling Pathway / 中国生物化学与分子生物学报

Neural tube defects (NTDs) are congenital defect diseases caused by cell proliferation and apoptosis disorders. Using RNA-Seq assays, we found the increased expression of DNA damage-inducible transcript 4 (Ddit4) in embryonic brain tissues from NTD fetuses. In this study, we intend to explore the effects of Ddit4 overexpression on the proliferation and apoptosis of HT-22 cells and related mechanisms to lay the foundation for the study of the role of Ddit4 in NTDs. According to the mouse Ddit4 sequence, we constructed the eukaryotic expression vector pEX-3-Ddit4. The results of restriction enzyme analysis and sequencing showed that the eukaryotic expression vector pEX-3-Ddit4 was successfully constructed. qRT-PCR and Western blotting results showed that the expression level of Ddit4 in HT-22 cells was significantly increased after transfection of PEX-3-Ddit4 (P < 0. 01) . CCK-8 and Western blotting results showed that Ddit4 overexpression decreased the proliferation of HT-22 cells (P < 0. 01) . Flow cytometry showed that Ddit4 overexpression increased the proportion of cells in the G

miR-145 downregulates the expression of cyclin-dependent kinase 6 in human cervical carcinoma cells.

The present study aimed to investigate the effect of the inhibition of miR-145 on cyclin-dependent protein kinase 6 (CDK6) and the proliferation of human cervical carcinoma cells. The miR-145 sequence was synthesized and cloned into pcDNA™6.2-GW to construct the recombinant plasmid pcDNA6.2-GW-miR-145. HeLa cells were divided into the micro (mi)R-145, normal control and blank groups. The transcription levels of miR-145 and CDK6 were detected using quantitative polymerase chin reaction and western blot analysis was used to examine the CDK6 protein expression. In addition, the inhibitory effect of miR-145 on the proliferation of HeLa cells was measured by an MTT assay. The recombinant plasmid pcDNA6.2-GW-miR-145 was successfully constructed and used to transfect the HeLa cells in the MiR-145 group. The miR-145 expression level in the miR-145 group was significantly higher than that in the blank group. The CDK6 expression level in miR-145 group was significantly lower than that in the blank group. Furthermore, miR-145 inhibited the proliferation of HeLa cells. In conclusion, miR-145 overexpression suppresses the expression of CDK6 and inhibits the proliferative ability of HeLa cells.

Construction and characterization of a eukaryotic expression vector of full-length and mature IL-37b / 中国比较医学杂志

Objective To construct a eukaryotic expression vector pEGFP N1/IL-37b of full-length and mature IL-37b,and to detect the expression of both full-length and mature IL-37b in RAW 264.7 cells, a mouse macrophage cell line. Methods To construct the eukaryotic vectors of full-length and mature IL-37b by using plasmid pUBC/IL-37b as a template containing the coding region of IL-37b full-length gene. To detect the expression of IL-37b by western blot and confocal microscopy after transfected the recombinant plasmid into RAW 264.7 cells, and to detect the inhibition of full-length and mature IL-37b on IL-6 production by real-time PCR. Results Eukaryotic vectors pEGFP N1/IL-37b expressed full-length and mature IL-37b after transfection in cells, which inhibited LPS-induced IL-6 production. Conclusions Eukaryotic vectors of full-length and mature IL-37b can be successfully constructed,and lays a foundation for further study of anti-inflammation functions and mechanisms of IL-37b.

hsa-miR-203 enhances the sensitivity of leukemia cells to arsenic trioxide.

The aim of this study was to investigate the effect of a eukaryotic expression vector expressing hsa-miR-203 on the sensitivity of K562 leukemia cells to arsenic trioxide (ATO) and the possible mechanism of action. The eukaryotic expression vector expressing the hsa-miR-203 plasmid (PmiR-203) was transfected into K562 cells using Lipofectamine 2000. bcr/abl 3' untranslated region (UTR) and bcr/abl mutated 3'UTR dual luciferase report vectors (psi-CHECK-2) were used to validate the regulation of bcr/abl by miR-203. The inhibitory effects of ATO and PmiR-203, used singly or in combination, on cell proliferation were detected by MTT assay. Apoptosis of the K562 cells was detected by flow cytometry using double-staining with Annexin V and propidium iodide (PI). The activities of caspase-3 and caspase-9 were detected by a colorimetric method and the cytochrome c protein levels were detected by western blotting. When used in combination with PmiR-203, the IC50 of ATO was reduced from 6.49 to 2.45 µg/ml and the sensitivity of cells to ATO increased 2.64-fold. In addition, PmiR-203 and ATO caused growth inhibition, apoptosis and G1-phase arrest in K562 cells. Furthermore, PmiR-203 significantly promoted ATO-mediated growth inhibition and apoptosis, affecting the G1 phase. JC-1 fluorescent staining revealed that the membrane potential of the mitochondria had changed. The activities of caspase-3 and caspase-9 increased, the expression levels of cytochrome c were upregulated and the expression level of bcr/abl mRNA was significantly suppressed. Furthermore, the dual-luciferase reporter vector, containing tandem miR-203 binding sites from the bcr/abl 3'UTR, demonstrated that bcr/abl was directly regulated by miR-203. PmiR-203 sensitized K562 leukemia cells to ATO by inducing apoptosis and downregulating bcr/ abl gene levels. The induction of apoptosis may occur through the mitochondrial pathway. The combination of ATO and PmiR-203 presents therapeutic potential for chronic myelogenous leukemia.

Site-directed mutagenesis of neonatal convulsions associated KCNQ2 gene and its protein expression.

OBJECTIVE: To study the protocol of construction of a KCNQ2-c.812G>T mutant and its eukaryotic expression vector, the c.812G>T (p.G271V) mutation, which was detected in a Chinese pedigree of benign familial infantile convulsions (BFIC), and to examine the expression of mutant protein in human embyonic kidney (HEK) 293 cells. METHODS: A KCNQ2 mutation c.812G>T was engineered on KCNQ2 cDNAs cloned into pcDNA3.0 by sequence overlap extension PCR and restriction enzymes. HEK293 cells were co-transfected with pRK5-GFP and KCNQ2 plasmid (the wild type or mutant) using lipofectamine and then subjected to confocal microscopy. The transfected cells were immunostained to visualize the intracellular expression of the mutant molecules. RESULTS: Direct sequence analysis revealed a G to T transition at position 812. The c.812G>T mutation was correctly combined to eukaryotic expressive vector pcDNA3.0 and expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both the wild type and mutant molecules on the plasma membrane, which suggested that the c.812G>T mutation at the pore forming region of KCNQ2 channel did not impair normal protein expression in HEK293 cells. CONCLUSIONS: Successful construction of mutant KCNQ2 eukaryotic expression vector and expression of KCNQ2 protein in HEK293 cells provide a basis for further study on the functional effects of convulsion-causing KCNQ2 mutations and for understanding the molecular pathogenesis of epilepsy.

Overexpression of the mTERT gene by adenoviral vectors promotes the proliferation of neuronal stem cells in vitro and stimulates neurogenesis in the hippocampus of mice.

We sought to construct the adenoviral vector carrying the gene encoding mouse telomerase reverse transcriptase (mTERT), as well as detect its expression and effect on the proliferation of neuronal stem cells. mTERT was amplified by RT-PCR and then the eukaryotic expression vector of pDC-EGFP-TERT was constructed. After DNA sequence analysis, we detected that there were 293 cells transfected with pDC-EGFP-TERT and helper adenovirus plasmid pBHG lox ΔE1, and three Cre using Lipofectamine 2000 mediation, named Ad-mTERT-GFP, to package adenoviral particles. The Ad-mTERT-GFP was used to infect neuronal stem cells and then the expression and activity of mTERT were detected. In addition, Bromodeoxyuridine labeling test identified the impact of mTERT overexpression on proliferation of neuronal stem cells. The recombinant adenoviral vector confirmed that mTERT was successfully constructed. Overexpression of mTERT stimulated the proliferation of neuronal stem cells both in vitro and in vivo. mTERT overexpression via adenoviral vector carrying mTERT cDNA upregulated the ability of proliferation in neuronal stem cells.

Role of B7-H6 over-expression in NK cell-mediated apoptosis of hepato-cytes / 中国病理生理杂志

AIM:To investigate the role of B7 homologue 6 (B7-H6) over-expression in natural killer (NK) cell-mediated hepatocyte apoptosis. METHODS:The full-length fragment of B7-H6 gene was amplified by PCR and sub-cloned into linearized eukaryotic expression vector pIRES2-EGFP to construct recombinant B7-H6 over-expression vector pIRES2-EGFP-B7-H6. The recombinant plasmid was identified by double digestion, PCR and sequencing, and was then transfected into L02 cells. The expression of EGFP was observed by fluorescence microscopy and the transfection efficiency was evaluated by flow cytometry. B7-H6 expression was confirmed by qRT-PCR and Western blot. The L02 cells transfect-ed with pIRES2-EGFP-B7-H6 recombinant plasmid were co-cultured with NK-92 cells at different effector/target ratios,and the cytotoxicity of NK-92 cells was evaluated by CCK-8 assay.RESULTS:The strong green fluorescence in the L02 cells was observed under fluorescence microscope 48 h after transfection. The transfection efficiency reached 92.6%. The ex-pression of B7-H6 at mRNA and protein levels was remarkably increased 48 h after transfection. The cytotoxicity of NK-92 cells against L02 cells transfected with pIRES2-EGFP-B7-H6 plasmid was significantly higher than that of the null vector transfection group (P<0.05).CONCLUSION:The recombinant eukaryotic expression vector pIRES2-EGFP-B7-H6 was constructed successfully. The cytotoxic effect of NK-92 cells against L02 cells can be enhanced by transfecting L02 cells with pIRES2-EGFP-B7-H6 plasmid.

Construction of rat beta defensin-2 eukaryotic expression vector and expression in the transfected rat corneal epithelial cell / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To construct a recombinant eukaryotic expression vector of rat beta defensin-2(rBD-2), transfect it into the rat corneal epithelial cells with lipofection, determine the expression of target gene in the transfected cells, and discuss the potentiality of recombinant plasmid expressed in corneal epithelial cells, hoping to provide an experimental foundation for further study on the antimicrobial activity of rBD-2 <i>in vitro </i>and <i>in vivo</i> and to assess the probability of defensins as a new application for infectious corneal diseases in the future. <p>METHODS: The synthetic rBD-2 DNA fragment was inserted between the <i>Xho</i>I and <i>BamHI</i> restriction enzyme cutting sites of eukaryotic expression vector pIRES2-ZsGreen1 to construct the recombinant plasmid pIRES2-ZsGreen1-rBD-2, then transformed it into <i>E.coli DH5α</i>, positive clones were screened by kanamycin and identified with restriction endonucleases and sequencing analysis. Transfection into the rat corneal epithelial cells was performed by lipofection. Then the experiment was divided into three groups: rat corneal epithelial cell was transfected with the recombinant plasmid pIRES2- ZsGreen1-rBD-2, rat corneal epithelial cell was transfected with the empty plasmid pIRES2-ZsGreen1 and the non-transfected group. The inverted fluorescence microscope was used to observe the transfection process. At last, the level of rBD-2 mRNA expressed in the transfected cells and the control groups are compared by the real-time fluoresence relative quantitative PCR. <p>RESULTS: The recombinant eukaryotic expression vector of pIRES2-ZsGreen1-rBD-2 was successfully constructed. The level of rBD-2 mRNA in transfected cells was significantly higher than that in control groups through the real-time fluorescence relative quantitative PCR. <p>CONCLUSION: The recombinant eukaryotic expression vector pIRES2-ZsGreen1-rBD-2 could be transfected into rat corneal epithelial cells, and exogenous rBD-2 gene could be transcripted into mRNA in the transfected cells.

Construction of eukaryotic expression vector of TSLC1 gene.

INTRODUCTION: To construct a eukaryotic expression vector of the tumour suppressor in lung cancer 1 (TSLC1) gene, so as to explore the mechanisms of tumour suppression of the gene theoretically. MATERIAL AND METHODS: The open reading frame (ORF) of TSLC1 gene was amplified with RT-PCR from normal human foreskin acrobystia, and cloned to pMD19-T simple vector (TA Clone method). The resultant plasmid was transformed into Escherichia coli JM109 for amplification. The TA Clone recombinant was digested by double restriction enzyme (Bgl II/EcoR I) and analysed with agarose gel electrophoresis. The positive one was sequenced. The inserted DNA fragment was recovered, and then it was mounted into the eukaryotic expression vector pIRES2-EGFP, transformed into E. coli JM109 for amplification. A positive recombinant plasmid named pIRES2-EGFP-TSLC1 was confirmed by Bgl II/EcoR I double-enzyme digestion analysis. RESULTS: RT-PCR amplified the ORF of the TSLC1 gene. It was approximately 1400 base pairs. The obtained DNA was confirmed a high degree of homology with the sequence of TSLC1 cDNA sequence (AY358334) stored at GenBank. CONCLUSIONS: Construction of a TSLC1 eukaryotic expression vector was successful, and it has established a solid foundation for further study.