Objective To study the transfection and expression of pleiotrophin (Ptn) gene in mice adipose-derived stem cells (ADSCs) so as to provide a new approach for the treatment of ischemic injury. Methods ADSCs from clean inbred C57BL/6W mice (weighing, 15-20 g) were isolated and cultured in vitro. The cell surface markers (CD29 and CD44) of ADSCs were identified by flow cytometry. The ADSCs were transfected with plasmid pIRES2-LEGFPN1 (containing Ptn gene coding sequence) as experimental group (group A) and with plasmid pLEGFP-N1 (containing GFP gene coding sequence) as control group (group B). After ADSCs were transfected by different plasmids respectively, the cells containing Ptn gene were selected by G418 (the best selected concentration was 200 μg/mL), and the immunophenotype of the cells was identified by flow cytometry after transfection. Meanwhile, real-time fluorescence quantitative PCR and Western blot were used to analyse the expression levels of Ptn mRNA and PTN protein in selected cells. Results The mice ADSCs were isolated and cultured successfully in vitro. The positive rates of the cell surface markers CD29 and CD44 of ADSCs were 99.5% and 95.8%, respectively; the double positive rate of CD44 and CD29 was 93.6%. The positive rates of the cell surface markers CD29 and CD44 of ADSCs were 99.1% and 95.6%, respectively after transfection of Ptn gene; the double positive rate of CD44 and CD29 was 93.4%. The expression levels of Ptn gene and PTN protein in group A were significantly higher than those in group B (P lt; 0.05). Conclusion The ADSCs can be stablely transfected by Ptn gene, the transfected ADSCs can express PTN protein highly, which is a new idea for tissue engineering of vascular reconstruction.
Objective To observe the the inhibitory effect of recombined adenovirus mediated delivery of p21 (rAd-p21) on oxygen-induced retinal neovascularization in mice. Methods A total of 56 C57BL/6 mice at the age of seven days were divided into control group, phosphate buffer solution (PBS) group, rAd-p21 group and rAdno purpose gene control (rAd-NC) group, 14 mice in each group. The retinal neovascularization of PBS, rAd-p21and rAd-NC group were induced by oxygen, and received an intravitreal injection 1 mu;l PBS, rAd-p21 and rAd-NC at postnatal day 11, respectively.The rats of control group were not intervened. At postnatal day 17,RNV was determined by retinal flat mounts and retinal section; non-perfusion areas of retina were analyzed by Image-Pro plus 6.0 software; reverse transcription-polymerase chain reaction (RT-PCR) and Western blot was used to measure the mRNA and protein expression of p21 and CDK2. Results Compared with PBS and rAdNC groups, the retinal nonperfusion areas, neovascularization and the numbers of endothelial cell nuclei breaking through the internal limiting membrane in rAd-p21 group were reduced significantly. Nonperfusion areas of retina in rAd-p21 group was less than that in PBS and rAd-NC groups, the difference among these three groups was significantly (F=101.634，P＜0.05). Compared with the other three groups, the level of p21 mRNA and protein in rAd-p21 group increased significantly (F=839.664, 509.817;P＜0.05); the level of CDK2 mRNA and protein in rAd-p21 group decreased significantly (F=301.858, 592.882;P＜0.05). Conclusion rAd-p21can inhibit oxygen-induced retinal neovascularization, up-regulated p21 expression and down-regulated CDK2 expression may be the mechanism.
Objective The biological treatment of intervertebral disc degeneration becomes a research hotspot in recentyears. It is necessary to find an effective approach to induce bone marrow mesenchymal stem cells (BMSCs) differentiate to disc cells which could make appl ication of cell transplantation as a treatment of intervertebral disc degeneration. To investigate the effects of the recombinant plasmid pcDNA3.1IE-SOX9Flag on differentiation of rabbit BMSCs into nucleus pulposus-l ike cells. Methods The eukaryotic expression vector of pcDNA3.1IE-SOX9Flag was constructed. Rabbit BMSCs were isolated and cultured from one-month-old New Zealand white rabbits and were induced into osteogenetic cells in the osteogenesis supplement medium; and the cell surface markers were detected by flow cytometry. The cells at the 3rd passage were randomly divided into 3 groups: in transfected group, the cells were transfected with recombinant plasmid pcDNA3.1IE-SOX9Flag; in negative control group, the cells were transfected with plasmid pcDNA3.1; and in blank control group, the cells were treated with the media without recombinant plasmid. After selected by G418 for 7 days, the cells were harvested and RT-PCR was employed to assay SOX9 mRNA and collagen type II gene (Col2al) mRNA expressions in BMSCs. The expression of SOX9 protein was assayed by Western blot and collagen type II expression was also observed by immunohistochemical staining. Results The SOX9 eukaryotic expression vector was constructed successfully. The BMSCs after 5 days of osteogenetic induction were positive for the alkal ine phosphatase staining. What was more, CD44 expression was positive but CD34 and CD45 expressions were negative. The transfection efficiency was 34.32% ± 1.75% at 72 hours after transfection. After 2 weeks of transfection, BMSCs turned to polygonal and ell iptical. And the cell prol iferation was gradually slow which was similar to the growth characteristic of nucleus pulposus cells. RT-PCR identification showed that SOX9 mRNA and Col2al mRNA expressions were positive in transfected group, and were negative in 2 control groups. Western blot detection showed that SOX9 protein expressed in transfected group but did not express in the control groups. At 2 weeks after transfection, the result of the immunohistochemicalstaining for collagen type II was positive in transfected group. Conclusion The recombinant plasmid pcDNA3.1IE-SOX9Flag can be successfully transfected into rabbit BMSCs, the transfected BMSCs can differentiate into nucleus pulposus-l ike cells, which lays a theoretical foundation for treatment of intervertebral disc degeneration with BMSCs transplantation.
ObjectiveTo investigate the bone regeneration potential of cell-tissue engineered bone constructed by human bone marrow mesenchymal stem cells (hBMSCs) expressing the transduced human bone morphogenetic protein 2 (hBMP-2) gene stably. MethodsThe full-length hBMP-2 gene was cloned from human muscle tissues by RT-PCR and connected into a vector to consturct a eukaryotic expression system. And then the gene expression system was transduced to hBMSCs with lipidosome. hBMSCs were transfected by hBMP-2 gene (experimental group) and by empty plasmid (negative control group), untransfected hBMP-2 served as blank control group. RT-PCR, dot-ELISA, immunohistochemical analysis and ALP activity were performed to compare and evaluate the situation of hBMP-2 expression and secretion after transfection. hBMSCs transfected by hBMP-2 gene were seeded on hydroxyapatite (HA) and incubated for 4 days to construct the hBMP-2 gene modified tissue engineered bone, and then the tissue engineered bone was observed by the inverted phase contrast microscope and scanning electron microscope. Then the hBMP-2 gene modified tissue engineered bone (group A, n=3), empty plasmid transfected hBMSCs seeded on HA (group B, n=3), hBMSCs suspension transfected by hBMP-2 gene (group C, n=3), and hBMP-2 plasmids and lipidosome (group D, n=3) were implanted into bilateral back muscles of nude mice. The osteogenic activity was detected by HE staining and alcian blue staining after 4 weeks. ResultsAt 48 hours and 3 weeks after transfection, RT-PCR and dot-ELISA results indicated that the transfected hBMSCs could express and secrete active and exogenous hBMP-2 stably. The immunohistochemical staining was positive, and the ALP activity in the transfected hBMSCs was significantly higher than that in two control groups (P < 0.05). The transfected hBMSCs had a good attaching and growing on the three-demension suface of HA under inverted phase contrast microscope and scanning electron microscope. In vivo study indicated that a lot of new bone formation was obviously found at 4 out of 6 sides of back muscles in group A. Some new bone formation at both sides of back muscles was observed in 1 of 3 mice in group B. No new bone formation was found in group C. A few new bone formation was observed at one side of back muscles in group D. ConclusionThe tissue engineered bone constructed by hBMP-2 gene modified hBMSCs and HA is able to express and secrete active hBMP2 stably and can promote new bone formation effectively in muscles of nude mice.
OBJECTIVE: To elongate the proliferation life-span of human umbilicus vein endothelial cell (HUVEC). METHODS: We synthesized the human telomerase reverse transcriptase mRNA (hTERT mRNA) by in vitro transcription, then transferred the hTERT mRNA into HUVEC in quicent stage by lipofect introduction. RESULTS: Telomerase expressed transiently in HUVEC, and the cell life-span was elongated for 7 population doublings. CONCLUSION: Telomerase can be reconstructed controllably and transiently in HUVEC by hTERT mRNA introduction, this method has the potential to be used to elongate the lifespan of cells cultured in vitro.
ObjectiveTo compare four different transfection reagents for transfection efficiency of rat heart myoblast cells H9C2, to choose the optimal transfection method.MethodsThe plasmids of enhanced green fluorescent protein (EGFP) gene were transfected as exogenous genes to H9C2 cells from four different transfection regents including FuGENE HD, DNA-In CRISPR, Lipofectamine 3000 and Lipofectamine 2000. Fluorescence intensity was measured by fluorescence microscopy and fluorescence microplate reader to evaluate transfection efficiency. The effects of four transfection reagents on cell viability were measured by Cell Counting Kit-8 (CCK-8) reagents.ResultsTransfection efficiency of Lipofectamine 3000 was the highest (>50%), while that of DNA-In CRISPR was the lowest (<1%). The cytotoxicity of Lipofectamine 3000 was the lowest in the four transfection reagents and the cell viability was 94.55% after 48-hour transfection.ConclusionTransfection regent Lipofectamine 3000 has the relatively high transfection efficiency as well as the lowest cytotoxicity, which is more suitable for use in H9C2 cells by transfection.
Objective To verify the potential of the recombinant adeno-associated virus 2 (rAAV2) vector as a strategy for human transforming growth factor β1 (hTGF-β1) gene transfer in degenerative intervertebral discs of rabbit, to investigate the gene transduction efficacy and to quantify the biologic effects on the proteoglycan level after gene transferring. Methods Rabbit models of disc degeneration were established by injecting the 25 μL fibronectin fragment (Fn-f, 1 mmol/ L), 4 weeks later,saline with or without virus was injected directly into 96 lumbar discs of 24 mature New Zealand white rabbits (male or female and weighing 1.7-2.2 kg) which were divided into 3 groups (n=8). Group A received the 25 μL rAAV2-hTGF-β1 (1 × 1012 vg/mL); group B received rAAV2-enhanced green fluorescent protein (rAAV2-EGFP); and group C received PBS. Two rabbits of groups A, C were killed 1 week after injection, the immunohistochemical staining for hTGF-β1 was performed on the sl ices of nucleus pulposus (NP) tissues. At 4, 8, and 12 weeks after gene transferring, NP tissues were harvested and cultured to quantify the changes of the proteoglycan level using 35S-sulfate incorporation assay. The expression of EGFP in group B was observed 12 weeks after injection. Results Immunohistochemical staining showed that extensive and intense positive immunohisochemical staining for hTGF-β1 were seen in group A when compared with group C 1 week after gene transferring. The nucleus pulposus tissues from the group A exhibited an increased synthesis of proteoglycan, which was significantly more than that from groups B and C (P lt; 0.05), and no significant difference was observed between group B and group C. The expression of EGFP in group B was high at 12 weeks. Conclusion The discs injected with rAAV2-hTGF-β1 can highly expressed the therapeutic proteins for more than 12 weeks, it is suggested that rAAV2 should be an valid vector for transferring exogenous genes in the degenerative disc. The therapeutic factors hTGF-β1 can efficiently increase the proteoglycan synthesis of the degenerative NP cells.
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.
【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.
Objective To investigate the effect s of T lymphoma invasion and metastasis inducing factor 1 ( Tiam 1) antisense oligonucleotides (ASODN) on morphological remodeling of gast ric cancer cells. Methods The high-invasive and metastastic subgroup (MH ) was separated f rom human gast ric cancer cell line MKN245 (M0 ) by laminin adhesion method in vi t ro. And they were divided into four group s according to different further t reatment s : no t ransfection group (cont rol group ) , liposome t ransfection group , sense oligonucleotides2liposome t ransfection group ( SODN t ransfection with liposome group ) and antisense oligonucleotides2liposome t ransfection group (ASODN t ransfection with liposome group) . Then the expressions of Tiam 1 mRNA and protein were detected by RT-PCR and flowcytomet ry , respectively. The morphology changes between Tima 1 ASODN t ransfected MH cells and no t ransfected cells were observed by using HE stain , cytoskeletal protein stain and scanning elect ronic microscope (SEM) . Results Compared with the other group s , the expressions of Tiam 1 mRNA and protein in MH cells were significantly decreased af ter the cells were t ransfected with 0. 43 μmol/ L Tiam 1 ASODN ( P lt; 0. 01) . Additionally , it was observed that the t ransfected MH cells had less membrane surface projections , fewer or shortener pseudopodia , less irregular cytoskeletal network and less spotted-like actin bodys than no t ransfected MH cells did. Conclusion ASODN t ransfection could effectively suppress the expression of Tiam 1 and the remodeling in gast ric cancer cells , which may play an important role in the invasion and metastasis of gast ric cancer cells.