Transfection and expression of murine interleukin-12 gene in B16F10 melanoma cells

AIM:To study the expression of murine interleukin-12(mIL-12) gene in B16F10 melanoma cells.METHODS:mIL-12 gene was inserted into pcDNA3.1 eukaryotic expression vector by DNA recombination and then transfected into B16F10 melanoma cells by electroporation. The integration and expression of mIL-12 gene in B16F10 melanoma cells were detected by PCR, RT-PCR and Western blot after positive cell clones had been screened.RESULTS:mIL-12 gene was confirmed to have been transfected and expressed in B16F10 cells on three levels of DNA, mRNA and protein.CONCLUSION:mIL-12 gene can successfully be transfected and expressed in B16F10 melanoma cells in vitro, which lays a foundation for the further investigation of mIL-12 gene tumor vaccine.     

Construction of eukaryotic expression vector and expression of outer membrane lipoprotein LipL41 gene of Leptospiria lai

AIM:To construct a eukaryotic expression vector expressing outer membrane lipoprotein LipL41 of Leptospira lai and express it in mammalian cell. METHODS:LipL41 gene was amplified by PCR from genome of Leptospira lai 017 strain, and was subcloned into vector pGEX-4T-1. After sequencing, LipL41 gene digested by restriction endonuclease and cloned into vector pcDNA3. After confirming the correctness of the eukaryotic recombinant vector by restrication enzyme digestion, it was transfected into COS7 cells by liposome. Its expression was analyzed by RT-PCR. RESULTS:A fragment of 1 011 bp was amplified, and sequence analysis showed it had a 98% homology with Leptospira kirschneri. The analysis of restriction enzyme indicated that the eukaryotic recombinant vector was correctly constructed. A specific amplified fragment was showed in the cells transfected with recombinant plasmid by RT-PCR, but the cell transfected with blank plasmid did not show this band. CONCLUSIONS:The LipL41 gene of Leptospira lai was successfully inserted into eukaryotic expression plasmid and the recombinant plasmid expressed the LipL41 mRNA.     

Construction and expression of reconstructive plasmids with human thrombomodulin gene

AIM: To provide experimental evidence for gene therapy of thrombophilia disease, we constructed the eukaryotic expression plasmid with human thrombomodulin (hTM) gene and observed the alteration of hTM expression on the surface of human umbilical vein endothelial cells (HUVECs) with and without the reconstructive plasmid. METHODS: The whole expressive fragment of hTM gene was amplified by PCR from human genome. Both hTM gene and pcDNA3.1(+)/neo empty vector was digested by HindⅢ and EcoRⅠ. Two digested fragments were ligated into pcDNA3.1/hTM with T₄DNA ligase. After identifying, the reconstructive plasmid transfected into HUVECs using lipofectin. The hTM antigen on the HUVECs was detected by immunohistochemistry. RESULTS: The hTM reconstructive plasmid was confirmed by double endonuclease redigesting and sequencing. About 10% HUVECs were transfected by pcDNA3.1/hTM plasmid with lipofectin and the high-level hTM was detected on the transfected cells. CONCLUSION: We constructed the pcDNA3.1/hTM plasmid successfully, and it could be expressed on the HUVECs.     

韧皮部特异启动子驱动密码子优化的抗菌肽D基因的植物表达载体构建

根据177个GenBank中登录的柑橘编码蛋白密码子用法的分析结果,优化并重新设计和合成了含柑橘偏爱密码子、对柑橘黄龙病有杀灭作用的柞蚕抗菌肽D基因(命名为CAPD),克隆入pUC19克隆载体并经测序验证后,获得了含新抗病基因的重组质粒pUC19-CAPD。用限制性内切酶BamHI和SacI双酶切pUC19-CAPD克隆载体和pBI121植物表达载体的质粒DNA,回收pUC19-CAPD克隆载体中的CAPD基因小片段和pBI121植物表达载体中去掉GUS报告基因的大片段,经连接、转化和鉴定后,构建了由CaMV35S组成型启动子(35SP)驱动CAPD目的基因的新植物表达载体(命名为pHZ05);用限制性内切酶BamHI和HindIII双酶切含笋瓜韧皮部特异启动子(PSP)的pUCm-PSP克隆载体和pHZ05植物表达载体的质粒DNA,分别回收pUCm-PSP克隆载体中的PSP小片段和pHZ05植物表达载体中去掉CAPD目的基因上游35SP的大片段,经连接、转化和鉴定后,构建了由PSP驱动CAPD目的基因的新植物表达载体(命名为pHZ06)。利用细胞感受态法直接将2个由不同启动子驱动的含CAPD目的基因的新重组植物表达载体分别导入根癌农杆菌LBA4404、GV3101、EHA105和发根农杆菌Ri15834等4个农杆菌菌株中,为利用农杆菌介导的遗传转化技术培育抵抗由韧皮部传导的毁灭性和检疫性病害柑橘黄龙病的新种质奠定了基础。     

Construction of human anti-HBc ScFv eukaryotic expression vector and expression of anti-HBc ScFv in HepG2 cells

AIM: To construct an eukaryotic expression vector of human single-chain variable fragment against hepatitis B virus core protein (anti-HBc ScFv) and detect its expression in HepG2 cells. METHODS: Anti-HBc ScFv genes were amplified from the plasmids abstracted from positive clone and inserted into pEGFP-c1 vector that contained green fluorescent protein gene. The recombinant plasmids were transfected into HepG2 cells, and resistant clones were obtained by G418 selection. The expression of the gene of fusion protein was determined by fluorescent invert microscope and ELISA. RESULTS: Recombinant plasmids were successfully constructed. The plasmid transfected HepG2 cells were obtained by G418 selection. Specific fluorescence was observed in HepG2 cells 48 hours after transfection. ELISA analysis confirmed the expression of anti-HBc ScFv in the cells. CONCLUSION: The construction of human anti-HBc ScFv eukaryotic expression vector and its expression in HepG2 cells lay the foundation for advanced research of intracellular anti-HBc ScFv.     

Construction and in vitro analysis of recombinant adenovirus vector carrying red fluorescent protein reporter gene

AIM: To provide important tools for gene therapy and gene vaccine research by constructing an adenovirus vector containing red fluorescent protein ( RFP ) reporter gene with the approach of in vitro recombinant ligation. METHODS: The RFP gene fragment of pTurboRFP-N was digested and ligated into pShuttle transfer vector to construct recombinant vector pShuttle-TurboRFP-N. I- Ceu I/PI- Sce I were used to double digest recombinant vector pShuttle-TurboRFP-N and backbone of vector pH5'040.pkGFP-II. The target fragment was collected and ligated, and recombinant adenovirus vector AdH5'.040.CMV.RFP-N was obtained. After linearization, the vector was transfected into AD293 cells by liposome for virus packaging. The efficiency of virus packaging and RFP expression level in AD293 cells were examined using fluorescent microscope. In addition, the biological activity and titer of the virus were tested. Human lung cancer cell line A549 and breast cancer cell line MDA-MB-231 were infected with recombinant adenovirus vector AdH5'.040.CMV.RFP-N and control adenovirus vector AdH5.CMV.EGFP respectively. The infection efficiencies of the 2 vectors to different cell lines were compared by evaluating the expression levels of RFP and enhanced green fluorescent protein (EGFP). RESULTS: The recombinant adenovirus vector AdH5'.040.CMV.RFP-N was correctly constructed and confirmed by enzyme digestion. The virus was packaged by the vector in AD293 cells and had the ability to infect the target cells. The target gene in eukaryotic cells was also expressed. The number of recombinant adenoviruses and the titer of the virus after amplification and purification were 3.6×10¹⁵ vp/L and 1×10¹³ pfu/L,respectively. The infection efficiencies of recombinant adenovirus vector Ad5'.040.CMV.RFP-N to human lung cancer cell line A549 and breast cancer cell line MDA-MB-231 were higher than those in control adenovirus vector AdH5.CMV.EGFP (P<0.05). CONCLUSION: We have constructed recombinant virus vector carrying RFP reporter gene and provide an important tool for gene therapy and gene vaccine research. The reporter gene can be highly expressed in AD293 cells and has high infection efficiency to cancer cells. RFP is a good substitution and supplement to green fluorescent protein.     

Construction of recombinant retroviral vector of short interfering RNAs specific for macrophage migration inhibitory factor (MIF) and establishment of stable HeLa cell line with a persistent knockdown of MIF

AIM: To construct recombinant retroviral vector of short interfering RNAs (siRNA) specific for macrophage migration inhibitory factor (MIF) and to establish the stable knockdown of MIF cell line of mammalian cells by transfecting the recombinant retroviral vectors. METHODS: We synthesized oligo-nucleotides for MIF in vitro, and cloned them into retroviral vector pSuper.retro. Subsequently the plasmids were sequenced and digested to identify the construction of the recombinant retroviral vectors. The vectors RNAi were transfected into packing cell line PHOENIX, which was selected by puromycin later. HeLa cell line was infected by the virus supernatant of stable PHOENIX cell lines, and the stable HeLa cell line showed significantly to silence MIF was established by selecting with puromycin. We also compare the characters of HeLa-pSuper-mock to HeLa-pSuper-MIF cells by using migration assay, adhesion assay, soft agar assay and FACS analysis of the cell-cycle progression. RESULTS: The recombinant retroviral vectors were constructed successfully. The HeLa cell line infected by the supernatant containing the retrovirus of package PHOENIX cells was persistent knockdown of MIF confirmed by Western blotting. Knockdown of MIF in HeLa cells inhibited the migration and adhesion, and decreased the clone formation. FACS analysis revealed that knockdown of MIF arrested HeLa cells in G0/G1 phase. CONCLUSION: We establish the stable HeLa cell line with a persistent knockdown of MIF. Our current studies reveal that MIF is necessary for HeLa cell migration and anchorage-independent growth.     

Construction of FAK-shRNA retroviral vector and screening of stable HCC-LM3 cell line with persistent knockdown of FAK

AIM: To construct a recombinant retroviral vector of short interfering RNA targeting focal adhesion kinase (FAK) gene and to establish a cell line with stable knockdown of FAK.METHODS: The oligonucleotides that transcribed to short hairpin RNA (shRNA) targeting FAK gene were synthesized in vitro, cloned into retroviral vector pSuper.retro and transfected into Phoenix cell line. The stable clones were screened and high-titer virus was produced. The human hepatocellular carcinoma cell line HCC-LM3 was infected with the virus-rich supernatant. The stable LM3 cell line, which showed significantly to silence FAK and associated proteins, was selected by puromycin.RESULTS: The recombinant retroviral vector was successfully constructed. Persistent knockdown of FAK in the LM3 cell line infected with the supernatant containing the retrovirus was confirmed by Western blotting. Down-regulation of FAK resulted in the inhibition of p-Akt and p-MAPK1/2 expression and led to decreased migration and invasion of the cells. The cell cycle was blocked at G₀/G₁ phase, and apoptosis was increased. The proliferation rate also decreased significantly.CONCLUSION: FAK-shRNA virus generated by recombinant retroviral vector pSuper-FAK can inhibit the protein expression of FAK and phosphorylation of Akt and MAPK1/2 in HCC-LM3 cells. Down-regulation of FAK shows a significant impact on biological behaviors of tumor cells.     

Using antisense nucleic acid technology to study the influence of POLκ on genetic stability

AIM:To establish cell line FL-POLκ^- and to study the role ofPOLκ(polymerase kappa) on genetic stability.METHODS:A mammalian expression vector expressing antisense POLκ gene fragment pMAMneo -amp^--POLκ was constructed by cloning the 1 690-1 918 fragment of POLκ gene into the mammalian expression vector pMAMneo-amp^- in antisense orientation. FL cells were fransfected with this antisense RNA expressing vector and selected by G418. Based on the shuttle-plasmid pZ189, the mutation assay was made.RESULTS:The spontaneous mutation frequency of supF tRNA gene in the plasmid replicated in the FL- POLκ^- was 11.2×10^-4, while it was 4.9×10^-4 and 3.7×10^-4 in the control cells FL and FL-M, respectively.CONCLUSION: POLκ playes an important role in maintenance of genetic stability.     

Construction of the retroviral vector recombinant of HBV-S gene and its expression in antigen presenting cells

AIM: To investigate the effectiveness of recombinanted retrovirus vector in gene therapy. METHODS: The retroviral vector pLXSN-S was constructed and transferred into PA317 by means of electroporation, then HepG₂、RAW264.7 and EL₄ cells were infected with the pseudovirus produced from PA317, which highly expressed HBsAg. HBsAg expression was tested by RT-PCR and ELISA. RESULTS: HBsAg was expressed variously in the eukaryotic cells mentioned above. HBsAg ( A value) of the cell supernatants (48 hours) were 0.92,0.53,0.42, respectively. CONCLUSION: The vector used in this study was an effective vector to carry genes of interest to target cells and macrophage, and high level HBsAg was expressed in antigen presenting cell such as macrophage, It indicated that plasmid immunity can induce the B lymphocyte and T lymphocyte response to hepatitis B virus surface antigen by stimulating macrophage. As a vector, it may be useful in the test for gene immunity and gene therapy.     

Preparation of gfp-bcl-XL-contained recombinant adenovirus vector by the homologous recombination in bacteria

AIM: To prepare gfp-bcl-X_L-contained recombinant adenovirus(rAd-gfp-bcl-X_L).METHODS: Bcl-X_L gene was amplified from pEGFP-C₃-bcl-X_L, subcloned into shuttle plasmid and formed transfer plasmid of pAdTrack-CMV-bcl-X_L. Then pAdTrack-CMV-bcl-X_L was linealinzed with PmeI and co-transformed into BJ5183 bacteria with adenovirus genomic plasmid of pAdEasy-1. The identified recombinant adenovirus plasmid was digested with PacI and transfected into 293 cells to package recombinant adenovirus particles. The target gene was detected by PCR.RESULTS: There were about 35% positive recombinant bacterial clones after the co-transformation of pAdTrack-CMV-bcl-X_L and pAdEasy-1 into BJ5183. Recombinant adenovirus particle were produced and further amplified after the transfection of pAdEasy-1-gfp-bcl-X_L into 293 cells. PCR test indicated that the recombinant Ad contained bcl-X_L gene. The titer of the purified rAd-gfp-bcl-X_L was 6.5×10¹² PFU/L. CONCLUSIONS: The homologous recombination in bacteria is a convenient and high efficient method to prepare rAd-gfp-bcl-X_L. This affords a good gene transfer vector for the gene therapy in human’s diseases.     

Cloning and expression of NK4 gene in Raji cells

AIM: To clone NK4 gene and to construct recombinant eukaryotic expression vector for observing its expression in transfected Raji cells. METHODS: Total RNA was extracted from human hepatic tissue. NK4 gene cDNA was amplified by RT-PCR, and then cloned into vector pVITRO2-mcs to construct the recombinant eukaryotic expression vector pVITRO2-mcs-NK4. Raji cells were transfected by recombinant vector pVITRO2-mcs-NK4 and screened by homomycin B. The stable strain of NK4 gene expression was screened by real-time fluorescent quantitative PCR, ELISA, immunocytohistochemistry and semisolid culture. RESULTS: The specific DNA fragment was detected by RT-PCR in Raji cells transfected with NK4 gene. The transfected Raji cells expressed NK4 mRNA and protein stably, which inhibited Raji cell proliferation, metastasis and invasion. CONCLUSION: NK4 gene is cloned and recombined to construct recombinant eukaryotic expression vector pVITRO2-mcs-NK4 successfully. NK4 gene in Raji cells expresses stably.     

Role of B7-H6 over-expression in NK cell-mediated apoptosis of hepatocytes

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 subcloned 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 transfected 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 expression 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 lentiviral vector-mediated siRNA knockdown of ER-α36and its action on gastric cancer cell growth

AIM: To construct a lentiviral vector for stable delivery of the ER-α36gene and to detect its effect on SGC7901 cell growth. METHODS: The efficient RNAi targeting sequences identified for the ER-α36gene were screened. The Oligo DNA was synthesized with target sequences and annealed to form double-stranded DNA. Then it was digested by XhoI and EcoR I and connected with GV307 vector to produce LV-ER-α36-RNAi lentiviral vector. PCR was used to screen the positive clones and sequence. The LV-ER-α36-RNAi, pHelper 1.0 and pHelper 2.0 plasmids were co-transfected into 293T cells for producing lentiviral vector and infecting SGC7901 cell line. Fluorescence microscopy, real-time PCR and Western blotting were used to detect the transfection efficiency and gene silencing effect. 17β-estrodial at concentration of 1×10-10 mol/L was used to stimulate the recombinant cell line, and the action on the growth of gastric cancer cells and the expression of Src, ERK1/2 and cyclin D1 were determined. RESULTS: DNA sequencing analysis confirmed the identity of recombinant shRNA expression vectors. Immunofluorescence assay demonstrated that transfection efficiency was above 80%. Transfection of LV-ER-α36-RNAi significantly knocked down the expression of ER-α36 at mRNA and protein levels with tetracycline (TeT) simulating as revealed by real-time PCR and Western blotting. Compared with control group, the growth of the recombinant cell line declined and the expression of Src, ERK1/2 and cyclin D1 and the activation of Src decreased (P<0.05).CONCLUSION: Lentiviral vectors that silenceER-α36expression are constructed successfully and can be used to study the role of ER-α36 in gastric cancer. The ER-α36is related with many kinds of cancer cell growth, including gastric cancer cells.     

Construction of mouse pdx-1 gene eukaryotic expression vector and its expression in embryonic stem cells

AIM: To clone mouse pdx-1 gene and construct its eukaryotic expression vector for expression of pdx-1 in mouse embryonic stem cells.METHODS: Mouse pdx-1 cDNA fragment was amplified with polymerase chain reaction (PCR) from mouse pancreatic cDNA. The purified fragment was recombinated with a eukaryotic expression vector carrying enhanced green fluorescent protein, pEGFP-N1. The pdx-1 cDNA fragment was inserted into the multi-clone sites of the vector to construct a new plasmid, pEGFP/pdx-1. E.colli strain DH5α was transfected with the new recombinant plasmid to expand it. Plasmid DNA extracted from the expanded DH5α was identifed by cutting with Hind Ⅲ, BamHⅠ nuclease and by DNA sequencing. Identified plasmid DNA was transfected into mouse embryonic stem cell line MESPU13 by carrying with liposome. RESULTS: A 876 bp cDNA fragment was amplified from mouse pancreatic cDNA by PCR and it was inserted into the vector pEGFP-N1 correctly. The fragment was defined to be pdx-1 gene by nuclease digestion and DNA sequencing. Mouse embryonic stem cell line MESPU13 was transfected with the new recombinant plasmid DNA. The green fluorescent protein report gene and pdx-1 gene expressed in transfected mouse embryonic stem cells within 24 h. CONCLUSION: Mouse pdx-1 gene is cloned and its recombinant eukaryotic expression vector carrying green fluorescent protein is constructed successfully. It provides a useful tool for further research on the function of pdx-1.     

Construction of recombinant retrovirus vector carrying hTERT and transfected to MSCs in human cord blood

AIM:To construct a recombinant retrovirus vector carrying hTERT for establishing UCBMSCs with hTERT (hTERT-MSCs) to overcome their limited life span and detecting whether telomerized UCBMSCs line maintained long-term self-renewal and differentiation capacity. METHODS:The whole cDNA was generated by PCR amplifications from the plasmid pEGFP-hTERT-C1. The hTERT segments were subcloned into pLNCX2. The target cells were infected with these retroviral particles. The stably transfected cells were selected by neomycin and expanded life span which were designated hTERT-MSCs was observed. The expression of hTERT in mRNA level was detected by RT-PCR and the telomerase activity was measured by TRAP (PCR)-ELISA assay. The hTERT-MSCs were induced with 5-azacytidine to cardiac muscle cells and the specific marker of myocardiocyte was detected. RESULTS:The constructed plasmids were digested with restriction endonucleases (BglⅡand NotⅠ). Two characteristic segments including 6.1 kb and 3.6 kb were obtained. The hTERT-MSCs expressed hTERT in mRNA level. The telomerase activity of hTERT-MSCs was positive. The growth kinetics of hTERT-MSCs was higher than those in UCBMSCs. The hTERT-MSCs were induced to myocardiocyte. CONCLUSION:The hTERT recombinant retrovirus vector has been successfully constructed. The hTERT gene activates the telomerase and prolongs the life-span of cells. No effect of hTERT gene on some type of differentiation potential of MSCs is present.     

Construction of shRNA targeting AGR2 gene and effect of AGR2 on biological function of nasopharyngeal carcinoma cells

AIM: To construct the shRNA targeting anterior gradient protein 2 (AGR2) gene for exploring the effect of AGR2 on the biological behavior of nasopharyngeal carcinoma (NPC) cells.METHODS: The expression of AGR2 at mRNA and protein levels in NPC cell lines 6-10B and 5-8F was detected by real-time PCR and Western blot. The pSR-GFP/Neo-AGR2-shRNA expression vector targeting AGR2 was constructed. Based on the interference targeting AGR2, the cell migration and motility were determined by Transwell migration and motility assays.RESULTS: The expression of AGR2 was increased in NPC cell line 5-8F compared with NPC cell line 6-10B (P<0.05). When the AGR2 expression in 5-8F cells was interfered, the cell migration, invasion and tumorigenicity were weakened.CONCLUSION: The expression of AGR2 is up-regulated in NPC cell line 5-8F. pSR-GFP/Neo-CLU-shRNA successfully inhibits the expression of AGR2 in NPC cell line 5-8F. AGR2 inhibits the migration, invasion and tumorigenicity of 5-8F cells in vivo.     

小西葫芦黄花叶病毒外壳蛋白基因植物表达载体的构建

小西葫芦黄花叶病毒(Zucchiniyellowmosaicvirus,ZYMV)是危害中国葫芦科作物主要病毒之一。试验以该病毒中国分离物外壳蛋白基因的克隆载体pZCP-87(含ZYMV的CP基因)为材料,经SalⅠ和BamHⅠ双酶切,从胶上回收目的基因,与经过同两种酶酶切的植物表达载体pBIN438连接,转化感受态的大肠杆菌细胞,提取质粒,经PCR和SalⅠ/BamHⅠ双酶切验证,已将该病毒外壳蛋白基因克隆到植物表达载体上(重组质粒命名为pBZCP5),采用冻融法完成了对pBZCP5质粒的农杆菌转化。该工作是通过转基因获得抗ZYMV病毒研究的基础。     

Construction of recombinant adenovirus expressing BDNF and its expression in expanded rat mesenchymal stem cells in vitro

AIM:To construct recombinant adenovirus vector containing brain derived neurotrophic factor, (BDNF) gene using bacterial homogenous recombination, and investigate the expression in expanded rat mesenchymal stem cells (rMSC) in vitro.METHODS:BDNF gene and proBDNF gene were subcloned into adenovirus shuttle plasmid pAdTrack-CMV containing enhanced green fluorescent protein gene (EGFP) expression cassette, forming shuttle vector of pAdTrack-BDNF, and pAdTrack-proBDNF, and co-transformed into BJ5183 bacterial cells with adenovirus backbone vector pAdEasy-1 using chemical transformation. After the recombinant adenovirus vector was obtained, the identified recombinant adenovirus plasmid DNA was digested with Pac I and transfected to 293 cells to package recombinant adenovirus particles. rMSC were infected by recombinant adenovirus and EGFP expression was detected using fluorescent microscope. Infection efficiency was assessed by flow cytometrics. Western blotting identified expression of Ad -proBDNF and Ad-BDNF in rMSC. rMSC infected with Ad -proBDNF and Ad-BDNF were induced to differentiate into neuron-like cells. rMSC infected with Ad -proBDNF and Ad-BDNF were injected into nude mice and assessd in vivo.RESULTS:We successfully constructed the recombinant adenovirus Ad -proBDNF and Ad-BDNF that expressed in expanded rMSC in vitro.CONCLUSION:Recombinant adenovirus high-effectively mediates Ad -proBDNF and Ad-BDNF expression in expanded rMSC in vitro and in vivo.     

Construction of lentiviral vector carrying the Ang-1 gene and its expression in the rMSCs

AIM: To construct lentiviral vector carrying the angiopoietin-1 (Ang-1) gene,and make it express Ang-1 in the rat mesenchymal stem cells (rMSCs).METHODS: The cDNA encoding the CDS of Ang-1 gene was obtained from the placenta of the adult Fisher 344 rats with RT-PCR.After digestion with restrication endonuclease,the Ang-1 gene was recombined to construct the transfer plasmid PNL-Ang1-IRES2-EGFP.The three-plasmid system of lentiviral vector was consisted of PNL-Ang1-IRES2-EGFP,the packaging plasmid HELPER,and the envelope plasmid VSVG,which were co-transfected to 293T cells mediated by lipofectamin2000 to produce lentiviral particles.The rMSCs were infected by obtained lentiviral particles.The insertion of Ang-1 gene was detected by PCR,the mRNA expression of Ang-1 in rMSCs was detected with RT-PCR,the protein expression of Ang-1 was observed with immunocytochemistry and Western blotting methods.RESULTS: The result of sequencing showed that the cloned Ang-1 gene was consistent with the sequence reported in GenBank.After digestion with restrication endonuclease,the 1 512 bp fragment of Ang-1 gene and the 10.5 kb vector fragment of PNL-IRES2-EGFP were observed with gel electrophoresis.The insertion of Ang-1 gene in viral genome was confirmed.The EGFP expression was observed with the fluorescent microscope.In infected rMSCs,the mRNA and protein expressions of Ang-1 were confirmed.CONCLUSION: Lentiviral vector carrying Ang-1 gene has been successfully constructed.The infected rMSCs are able to express the Ang-1 mRNA and Ang-1 abundantly.This will facilitate the following exploratory development of Ang-1 gene-modified rMSCs.