Objective To study the feasibility of core-binding factor α1 (Cbfa1) gene modified marrow mesenchymal stem cells (MSCs) composed with porcine acellular bone extracellular matrix in repairing the radial defects. Methods Radial defects of 1.2 cm in length were created in 40 Japanese white rabbits and they were divided into four groups. In group A, MSCs isolated from homogeneous rabbits were infected with Cbfa1 recombinant adenovirus and implanted into acellular bone exteracellular matrix, and then the complexes were implanted into defects. In group B, the complexes including the MSCs without Cbfa1 gene-modified and scaffoldmaterial were implanted into defects. In group C, only the scaffold material was implanted. In group D, defects were not treated as the control. The macroscopic, X-ray and histologic analysis were performed to evaluate the repair effect at 4, 8 and 12 weeks postoperatively. The repaired radius were examined by biomechanical test at 12 weeks postoperatively. Results By gross examination，mature hard new bone formed at grafted areas at 12 weeks postoperativelyin group A, osteotomized ends connected by much callus in group B and less callus in group C at grafted areas. In contrast, bone nonunion formed in group D. X-ray and histological examination showed that the repaired results of defects in the group A were better than those in others groups evidently in extracellular matrix degradation, new bone remodeling and marrow cavity rebuilding at 4 and 8 weeks postoperatively. At 12 weeks postoperatively, the cortical bone became mature lamellar bone, new bone remolding was complete and marrow cavity was smooth in group A. Only proximal end of defects showed that marrow cavity was remolded partially in group B. The continuous callus could be observed in bone defect, and no obvious marrow cavity remolding was observed in group C. Lots of fibrous connective tissue filled in defect and bone nonunion was shown in group D. There was no significant difference in the damage compress loading of repaired radius between groups A, B and D (Pgt;0.05), but there was significant difference between groups C and D(Plt;0.01).Conclusion These results demonstrate that Cbfa1 gene modified MSCs combined with acellular bone extracellular matrix can be used to repair rabbit radial defects.
Objective To investigate the expression of micro-dystrophin gene in myoblast cultured in vitro, to explore the possibil ity of combining myoblast transplantation with gene transfer for Duchenne muscular dystrophy therapy. Methods Competent Escherichia coli JM109 was prepared, which transformed with plasmid pSL139, and positive clones were picked to cultivate. Plasmid was extracted with Alkal ine lysis method and cutted with both Pvu I and Cla I enzyme. Agarose gel electrophoresis was employed to take pictures. Ten healthy 5-7 days old male C57/BL10 mice were selected, weighing4-5 g, the primary and subcultured myoblasts were cultured with multi-step enzymatic digestion and differential adhesionmethod, and Desmin immunofluorescent method was used to identfy. The 3rd generation myoblasts that were transfected with plasmid pSL139 mediated by l iposome served as the experimental group, untransfected cells served as the control group. After 48 hours of transfection, the expressions of micro-dystrophin mRNA and protein in myoblasts were detected with RTPCR and cell immunofluorescent methods, and the transfection efficiency was caculated. Results After pSL139 plasmids being digested and for 40 minutes agarose gel of electrophoresis, 3.75 kb fragment of target gene and vector were observed. The cells were almost uniform, and triangular or diamond shape after 24-48 hours of culture; the cells turned to fusion manner and could be passaged after 4-6 days. Desmin immunofluorescent result showed that green fluorescence was seen in cytoplasm of most 2nd myoblasts, and the purity of the myoblasts was above 90%. At 48 hours after transfection of myoblasts with plasmid pSL139, RT- PCR results showed that about 300 bp fragment was seen in the experimental group and the control group, and the brightness was higher in experimental group. Immunofluorescent staining displayed that green fluorescence was seen in the cytoplasm of the myoblasts in the experimental group and no green fluorescence in the control group; the expression efficiency of positive cells for micro-dystrophin was 45%-55% in experimental group. Conclusion Micro-dystrophin gene can highly express at the levels of mRNA and protein respectively in myoblasts transfected with plasmid pSL139 mediated by l iposome.
ObjectiveTo observe the effect of adenovirus-mediated Tum5 (rAd-Tum5) inhibiting retinal neovascularization (RNV) of oxygen-induced retinopathy (OIR) mouse model.
MethodsThe OIR model was induced in 96 C57BL/6J mice aged of 7 days according to the literature. These mice were divided randomly into control group, OIR group, OIR rAd-green fluorescent grotein (GFP) group and OIR rAd-Tum5 group, each group had 24 mice. The rAd-GFP and rAd-Tum5 were injected into the vitreous cavity of mice aged of 12 days in OIR rAd-GFP group and OIR rAd-Tum5 group, respectively. Meanwhile, OIR group and the control group received the injection of physiological saline solution of same volume. The relatively non-perfusion area was evaluated by fluorescence angiography, and the number of pre-retinal nucleus breaking through internal limiting membranes was observed by hematoxylin-eosin staining. The expression of vascular endothelial growth factor (VEGF) was estimated by immunofluorescent (IF) and Western blot.
ResultsThe retinal avascular areas of all groups were significantly different (F=61.224, P<0.01). The retinal avascular area of the rAd-Tum5 group was decreased significantly comparing with that in the OIR group and rAd-GFP group (P<0.01). However, there are no significant differences between the OIR group and rAd-GFP group (P=0.827). The number of pre-retinal nucleus breaking through ILM of all groups was significantly different (F=635.738, P<0.01), but no significantly difference was observed in OIR group and rAd-GFP group (P=0.261). Significant differences could also been seen between OIR rAd-Tum5 group and OIR group as well as OIR rAd-Tum5 group and OIR rAd-GFP group (P<0.01). The results of IF and Western blot indicated that expression of VEGF in the OIR group and rAd-GFP group was obviously up-regulated, compared with that in the control group. But the expression was declined in the rAd-Tum5 group compared with that in the OIR group and rAd-GFP group.
ConclusionTum-5 peptide can efficiently prevent RNV probably by down-regulating expression of VEGF.
【Abstract】ObjectiveTo study the effect of transfection with antisense DNMT3b gene eukaryotic expression vector on the expression of DNMT3b gene in human cholangiocarcinoma cell line QBC-939. MethodsThe constructed antisense DNMT3b gene eukaryotic expression vector was transfected into the human cholangiocarcinoma cell line QBC-939 by using lipofectamine transfection reagents, and positive cell clones were obtained by using G418 selection after transfection. Whether the constructed recombinant vector was transfected into QBC-939 cells successfully was confirmed by amplifying the exogenous neoR gene with PCR method. The expression of DNMT3b gene mRNA and protein were detected by semi-quantitative RT-PCR and FCM methods respectively. ResultsFollowing the transfection of antisense DNMT3b gene eukaryotic expression vector, the mRNA level of DNMT3b gene in QBC-939 cells of human cholangiocarcinoma decreased from 0.956±0.053 to 0.209±0.023, and the protein level of DNMT3b gene also decreased from (75.38±3.22)% to (29.87±3.46)%. There were very significant differences on the expression levels of DNMT3b gene between non-tranfections group and the antisense DNMT3b gene eukaryotic expression vector transfection group (P＜0.01). ConclusionTransfection with antisense DNMT3b gene eukaryotic expression vector significantly reduces the expression level of DNMT3b gene in human cholangiocarcinoma cell line QBC-939, and this study may provide a valid tool and method to investigate the function of DNMT3b gene and its role in cholangiocarcinoma.
ObjectiveTo elucidate whether hypoxia induced factor-1α (HIF-1α) gene improved hypoxia tolerant capability of bone marrow mesenchymal stem cells uptake(MSCs) or not and whether the capability was related to glucose uptake increase in hypoxia MSCs ex vivo or not. MethodsMSCs were randomly divided into normoxia non-HIF-1α transfection group (control group), normoxia HIF-1α transfection group, hypoxia non-HIF-1α transfection group, and hypoxia HIF-1α transfection group and then each group was cultured with normoxia (5% CO2 at 37 ℃) or hypoxia (94% N2, 1% O2, 5% CO2 at 37 ℃) for 8 h, respectively. Finally, the expressions of HIF-1α were detected by immunocytochemistry, RT-PCR, and Western blot methods, respectively. Apoptosis ratio (AR) and death ratio (DR) were tested by flow cytometry. The proliferation was detected by MTT method. Glucose uptake was assayed by radiation isotope method. Results① Compared with the normoxia non-HIF-1α transfection group, the expression of HIF-1α mRNA significantly increased (Plt;0.01) in the normoxia HIF-1α transfection group except for its protein (P=0.187); Both of mRNA and protein expressions of HIF-1α in the hypoxia HIF-1α transfection group were significantly higher than those in the hypoxia non-HIF-1α transfection group (Plt;0.01). ② The AR (P=0.001) and DR (P=0.003) in the hypoxia HIF-1α transfection group were significantly lower thanthose in the hypoxia non-HIF-1α transfection group, both of which were significantly higher than those in the normoxia non-HIF-1α transfection group (Plt;0.01). ③ The proliferation of MSCs in the hypoxia HIF-1α transfection group was significantly higher than that in the hypoxia non-HIF-1α transfection group (P=0.004), which significantly lower than that in the normoxia non-HIF-1α transfection group (P=0.001). ④ Compared with the hypoxia non-HIF-1α transfection group, the 3H-G uptake capability (P=0.004) of MSCs significantly increased in the hypoxia HIF-1α transfection group, which was significantly lower than that in the normoxia non-HIF-1α transfection group (P=0.001). ⑤ There were significantly negative relation between AR and HIF-1α protein (r=－0.71，P=0.005) or 3H-G uptake (r=－0.65，P=0.004), and significantly positive relation between HIF-1α protein expression and 3H-G uptake (r=0.77, P=0.003). ConclusionHIF-1α gene significantly improves anti-hypoxia capability of MSCs, which is fulfilled by increasing glucose upake.
Objective To construct a recombinant adenovirus vector containing human vascular endothelial growth factor 165 (hVEGF165) [pAdxsi-enhanced green fluorescent protein (EGFP)-hVEGF165], and to observe the expression ofhVEGF165 by transfecting pAdxsi-EGFP-hVEGF165 into rat bone marrow mesenchymal stem cells (BMSCs) in vitro so as to lay a foundation for further research on gene therapy of blood vessel regeneration. Methods hVEGF165 was l iberated from plasmid and was subcloned into pShuttle-EGFP. The pShuttle-cytomegalo-virus-EGFP was then transferred to pAdxsi vector, by which pAdxsi-EGFP-hVEGF165 virus plasmid was obtained and was identified by enzymes restriction analysis and gene sequencing. The pAdxsi-EGFP-hVEGF165 was l inearized by digestion with restriction endonuclease PacI, and was then transfected into human embryonic kidney cells (HEK293). The retrieved recombinant adenovirus was titrated by using 50% tissue culture infective dose assay. The rat BMSCs were cultured and were infected with recombinant adenovirus containing EGFP (pAdxsi-EGFP). The multipl icities of infection (MOI) of transfection were determined by fluorescent inverted phase contrast microscope and flow cytometry (FCM), by which the most optimal value of MOI was confirmed and was used for transfecting pAdxsi-EGFP-hVEGF165 into BMSCs. The expression of hVEGF165 gene was indentified by performing Western blot, RT-PCR, and ELISA. The effect of transfection on BMSCs prol iferation was assessed by MTT. Results The expression of hVEGF165 cDNA in recombinant adenovirus plasmid was indentified by enzymes restriction analysis and gene sequencing. The titer of virus could be up to 1 ×1010 pfu/mL after several rounds of transfection and ampl ification. The efficiency of transfection on FCM was 88% when MOI being 150 pfu/ cell, at which the most optimal of MOI was achieved, as observed on fluorescence. The expressions of hVEGF165 at both mRNA and protein levels were detected after 48 hours of the transfection. The results of ELISA showed the expression ofhVEGF165 peaked at 7 days, and the production was found even after 20 days. Furthermore, the expression of hVEGF165 protein at 1, 3, 5, 7, 9, 11, 13, 15, and 20 days in the group transfected with pAdxsi-EGFP-hVEGF165 was significantly higher than that in the group transfected with pAdxsi-EGFP and in untransfected group (P lt; 0.05). The results of MTT demonstrated that here was no significant difference in absorbance (A) value between transfected with pAdxsi-EGFP-hVEGF165 group and untransfected group (P gt; 0.05). Conclusion BMSCs are suitable for gene transfection, and hVEGF165 gene can be transferred into BMSCs with high efficiency using pAdxsi-EGFP-hVEGF165 at a MOI of 150 pfu/cell. The transfected BMSCs can highly express hVEGF165, which has no effect on BMSCs growth and prol iferation.
Objective To identify glial cell line-derived neurotrophic factor (GDNF) recombinant retroviral vector and to establish its packaging cell line PA317. Methods PA317 cells were transfected with recombinant retroviral vector pLXSN-GDNF using liposomes. The recombinant retroviral particles were then harvested from culture media of G418 resistant transfected cells and analyzed using RT-PCR. Virus titers in supernatants were investigated. Results Sequencing date indicated that GDNF gene was exactly identical to the sequence in the GeneBank. PA317 cells were transfected with recombinant retroviral vector pLXSN-GDNF using liposomes, and virus titers insupernatants harvested from culture media of G418 resistant transfected cells were 104-105 CFU/ml. Conclusion Packaging cell line PA317/pLXSN-GDNF was established.
Objective To observe the effects of vascular endothelial growth factor antisense oligonucleotide (VEGF-ASODN) on expression of vascular endothelial growth factor (VEGF) and growth in gastric cancer cells. Methods The VEGF-ASODN was synthesized artificially with phosphorothioic acid. After transfecting with VEGF-ASODN in gastric cancer cells SGC-7901, the initial copy number of mRNA was detected by real-time RT-PCR, and the quantity of VEGF protein in both cell and supernatant were detected by ELISA. The levels of expression of survivin protein in cells were measured by Western blot. FCM and MTT method were used to detect cellular apoptosis and the activity of cells, respectively. The effect of transfection on the growth of cells was evaluated by growth curve. Results The copy number of VEGR mRNA, protein levels of VEGF in the cells and in culture fluid all decreased when the concentration of transfected VEGF-ASODN increased, as well as the levels of survivin protein （P＜0.05）. The ratio of apoptosis increased, the activity of cells also decreased as the concentration of transfected VEGF-ASODN increased （P＜0.05）. Conclusion Transfection with VEGF-ASODN in gastric cancer cells SGC-7901 can inhibit the expressions of VEGF and survivin remarkably. It can enhance cellular apoptosis and suppress growth of cells.
Objective According to heparanase’s gene sequence of GenBank, to construct heparanase gene-targeted small interfering RNA (siRNA) and its expression vector and to observe its interference effect on the expression of heparanase gene in human malignant breast cancer MDA-MB-231 cell. Methods Heparanase gene-targeted hairpin siRNA was designed, two complementary oligonucleotide strands were synthesized and inserted into pGPU6/GFP/Neo vector, which was identified by sequence identify. Human malignant breast cancer MDA-MB-231 cell was transfected with the constructed vector with lipofectamine method. Fluorescence photograph was taken. Real-time PCR (RT-PCR) was performed to evaluate the level of heparanase mRNA expression. Results Four kinds of heparanase gene-targeted hairpin siRNA were designed, then were inserted into pGPU6/GFP/Neo vector after annealing. Sequencing indicated the construction was successful. Fluorescence photographs showed MDA-MB-231 cells were transfected successfully. RT-PCR showed that heparanase mRNA expression levels were inhibited significantly （Plt;0.05）. Conclusion The heparanase gene-targeted siRNA and its vector are successfully constructed and MDA-MB-231 cells are transfected successfully. Heparanase mRNA expression levels are significantly inhibited by siRNA vector, which provide a new method for the treatment of cancer.
ObjectiveTo determine the optimizing parameters in transfecting the SV-40-PED cells mediated by oligofectamine. Methods With a change of Decoy oligodeoxynucleotides(ODNs)/oligofectamine in ratio and the transfection time, the uptake rate and the mean fluorescence intensity of SP1 ODNs in the SV-40-PED cells were measured by flow cytometry to evaluate the transfection efficiencies. 4 μl oligofectamine with different concentrations of ODNs(2.5，5.0，7.5，10.0 and 12.5 μl) were put into 100 μl of DMEM without serum and antibiotics. the (SV-40-PED) cells were transfected after 20 min at room temperature. the final concentration of SP1 decay ODNs were 50，100，150，200 and 250 nmol/L. Transfection effieiency was detected at 26 h after transfection. The intracellular distribution ofSP1 ODNs was determined with a fluorescence microscope. The lactate dehydrogenase (LDH) activity in the supernatant was measured to assess the cytotoxicity.Results The uptake of SP1 ODNs into the SV-40-PED cells was significantly improved by oligofectamine. The cell appearance did not change much in the groups of 50, 100 and 150 nmol/L. In the groups of 200 and 250 nmol/L, the cell reverted after being shrinked and altered to round. At 26 h after the transfection, there was no marked change in the cell form at the concentration of 250 nmol/L. There was floatation at 48 and 72 h after the transfection. Under the fluorescence microscope, we observed fluorescent materials distributed in the cell nucleus in the successfully-transferred groups. We could see the nucleoli clearly in the groups of 200 nmol/L and 250 nmol/L. There was a ber fluorescence intensitywith a higher concentration and the fluorescent materials gathered at the cell nucleus. At the final concentration of 250 nmol/L, the LDH level was 137.12±3.92 U/L in the 72hgroup, which was significantly higher those that in the 26h group（49.61±17.13 U/L）and the 48h group（120.26±8.42 U/L）(Plt;0.01). At 26 h after the transfection, there were no statistical differences at the above LDHlevels in the different-concentration groups（Pgt;0.05）. Conclusion Transfection efficiency is the highest when the final concentration of the SP1 decoy ODNs is 250 nmol/L during the incubation of for 24 h in transfecting the SV-40-PED cells.
