Green fluorescent protein as marker in chondrocytes overexpressing human insulin-like growth factor-1 for repair of articular cartilage defects in rabbits

Objective:To label the primary articular chondrocytes overexpressing human insulin-like growth factor (hIGF-1) with green fluorescent protein (GFP) for repair of articular cartilage defects in rabbits. Methods: GFP cDNA was inserted into pcDNA3. 1-hIGF-1 to label the expression vector. The recombinant vector, pcGI, a mammalian expression vector with multiple cloning sites under two respective cytomegalovirus promoters/enhancers, was transfected into the primary articular chondrocytes with the help of lipofectamine. After the positive cell clones were selected by G418, G418-resistant chondrocytes were cultured in medium for 4 weeks. The stable expression of hIGF-1 in the articular chondrocytes was determined by in situ hybridization and immunocytochemical analysis and the GFP was confirmed under a fluorescence microscope. Methyl thiazolyl tetrazolium ( MTT) and flow cytometer methods were employed to determine the effect of transfection on proliferation of chondrocytes. Gray value was used to analyze quantitatively the expression of type II collagen. Results: The expression of hIGF-1 and GFP was confirmed in transfected chondrocytes by in situ hybridization, immunocytochemical analysis and fluorescence microscope observation. Green articular chondrocytes overexpressing hIGF-1 could expand and maintain their chondrogenic phenotypes for more than 4 weeks. After the transfection of IGF-1, the proliferation of chondrocytes was enhanced and the chondrocytes could effectively maintain the expression of typeⅡcollagen. Conclusions: The hIGF-1 eukaryotic expression vector containing GFP marker gene has been successfully constructed. GFP, which can be visualized in real time and in situ, is stably expressed in articular chondrocytes overexpressing hIGF-1. The labeled articular chondrocytes overexpressing hIGF-1 can be applied in cell-mediated gene therapy as well as for other biomedical purposes of transgenic chondrocytes.     

可体内、外示踪的BMP2真核表达载体的构建和表达

Objective To construct green fluorescent protein (GFP)-labeled pSELECT-GFP zeohBMP2 eukaryotic expression vector. Methods The encoding fragment of hBMP2 gene was obtained from a recombinant plasmid pcDNA3.1/CT-hBMP2 by using polymerase chain reaction (PCR). hBMP2 gene was inserted into pTA2-T-easy and pSELECT-GFPzeo-MCS eukaryotic expression vector, and then transferred into competence DHSα cells. After screening, pSELEC-GFPzeo-hBMP2 was obtained and identified by sequence analysis. The recombinant vector pSELECT-GFP zeo-rhBMP2 was transfected into CHO cells. The successful trasfection was verified by fluorescence microscope in 48-72 hours. The RT-PCR and immunofluorescence was used to confirm the hBMP2 expression. Western Blotting was used to detect the secretion of hBMP2.Results A 1216 bp fragment was obtained by PCR, the same as expectant fragment. The recombined pSE-LECT-GFPzeo-hBMP2 eukaryotic expression vector was identified by restriction mapping and sequence analysis. The results were identical with that of reported hBMP2 sequence (Genebank NM-001200). The successful transfection was verified by fluorescence microscope in 48-72 hours. The stable expression in eukaryotic cells was confirmed by immunofluorescence and RT-PCR which showed an obvious band between 1000-2000 bp. Western Blotting identified the immunogenicity of recombinant human BMP2 with the molecular weight of about 17×103. Conclusion The pSELECT-GFPzeo-hBMP2 eukaryotic expression vector was constructed successfully.     

Green fluorescent protein as marker in chondrocytes overexpressing human insulin-like growth factor-l for repair of articular cartilage defects in rabbits

Objective： To label the primary articular chondrocytes overexpressing human insulin-like growth factor （ IdGF-1 ） with green fluorescent protein （GFP） for repair of articular cartilage defects in rabbits. Methods： GFP cDNA was inserted into PeDNA3.1- hlGF-1 to label the expression vector. The recombinnnt vector, pcGI, a mammalian expression vector with multiple cloning sites under two respective cytomegalovirus promoters/enhancers, was transfected into the primary articular chondrocytes with the help of lipofectamine. After the positive cell clones were selected by G418, G418- resistant chondrocytes were cultured in medium for 4 weeks. The stable expression of hlGF-1 in the articular chondrocytes was determined by in situ hybridization and immunocytochemical analysis and the GFP was confirmed under a fluorescence microscope. Methyl thiazolyl tetrazolium （MTT） and flow cytometer methods were employed to determine the effect of transfection on proliferation of chondrocytes. Gray value was used to analyze quantitatively the expression of type lI collagen. Results： The expression of hlGF-1 and GFP was confirmed in transfected chondrocytes by in situ hybridization, immunocytochemical analysis and fluorescence microscope observation. Green articular chondrocytes overexpressing hlGF-1 could expand and maintain their chondrogenic phenotypes for more than 4 weeks. After the transfectton of IGF-1, the proliferation of chondrocytes was enhanced and the chondrocytes could effectively maintain the expression of type lI collagen. Conclusions： The hlGF-1 eukaryotic expression vector containing GFP marker gene has been successfully constructed. GFP, which can be visualized in real time and in situ, is stably expressed in articular chondrocytes overexpressing hlGF-1. The labeled articular chondrocytes overexpressing hlGF-1 can be applied in cell-mediated gene therapy as well as for other biomedical purposes of transgenic chondrocytes.     

Reciprocal action between BMP-2 and BMP-3 in cultured fibroblast in vitro

Objective:To explore reciprocal action between BMP-2 (bone morphogenetic protein-2)and BMP-3 for better understanding of the mechanism of BMP during bone fracture union.Methods:rhBMB-2 was added into the cultured fibroblasts with the concentration of 1200 ng/ml.The expression of BMP-3 in fibroblasts was detected by immunohistochemistry.Eukaryotic expression vector pcDNA3-BMP-3 was transfected into the fibroblasts.After the effective expression of BMP-3 was identified,BMP-2 was also detected by immunohistochemistry in BMP-3 expression cells.The fibroblasts transfected with empty vector pcDNA3 were used as the control.Results:Exogenous rhBMP-2 could promote the expression of BMP-3 in fibroblasts. BMP-3 also could be detected in these cells.Conclusions:BMP-2 and BMP-3 could reciprocally adjust the expression in fibroblasts.     

Heterologous expression of rat testis GABA_A receptor P3t variant in Chinese hamster ovary cells

Aim: To study the characteristics and possible retention function of specific sequence in the 5'-end of rat testis GABAA receptor β 3t variant. Methods: Rat testis GABAA receptor β 3t variant cDNA was cloned and inserted into two eukaryotic expression vectors of pEGFP-Nl and pEGFP-Cl respectively, which have EGFP reporter gene. The recombinant plasmids were transfected into Chinese hamster ovary (CHO) cells with the calcium phosphate co-precipitation method. Fluorescence microscope and laser confocal microscope were used to analyze the transfected cells. ConA-Texas-Red was used to label cell endoplasmic reticulum (ER) and study the located area of rat testis β 3t variant in the CHO cells. Results: When the rat testis β 3t variant express in CHO cells, there were two expression pattern, the even and the concentrated expression pattern. Although rat brain β 3 can reach cell membrane, the rat testis β 3t variant can't target to the cell membrane. It may be retained in the ER of CHO cells. Conclusion:     

HCCR-2反义核酸对肝癌HepG2细胞的作用

Objective To investigate the effects of antisense recombinant euraryotic expression vector of HCCR-2 on the proliferation and apoptosis of HepG2. Methods The antisense recombinant eukaryotic expression vector of HCCR-2 was constructed. The vector was stably transfected to the HepG2 cells, and positive clones were selected by G418 (antiseuse vector group), pIRES2-EGFP vector was transfected into the HepG2 cells in the same way (pIRES2-EGFP group). The conditions of the nontransfected HepG2 cells were used as control (HepG2 group). Changes in cell growth curve, cell cycle, cell apoptosis and morphology of HepG2 cells after the transfec-tion were detected by MTT method, flow cytometry and transmission electron microscopy, respectively. All the data were analyzed by one-way ANOVA and chi-square test. Results The expression level of HCCR-2 mRNA was down-regulated to 0.39±0.04 in antisense vector group, and the expression level of HCCR-2 mRNA in pIRES2-EGFP group and HepG2 group were 0.62±0.06 and 0.72±0.03, respectively, with significant difference among the 3 groups (F=43.701, P<0.05). The apoptotic rate of HepG2 cells in antisense vector group, pIRES2-EGFP grop and HepG2 group were 13.30%, 2.51% and 2.07%, respectively, with significant difference among the 3 group (χ2=6.793, 8.721, P<0.05). The growth of HepG2 cells in antisense vector group was retarded, and was blocked in G0/G1 stage. Conclusions The HCCR-2 antisense recombinant eukaryotic expression vector can inhibit the mRNA expression of HCCR-2 and promote the apoptosis of cells. HCCR-2 may be involved in cell regulation and the proliferation of hepatocellular carcinoma cells.     

RhoA基因沉默对肝癌HepG2细胞增殖和迁移能力的影响

Objective To construct a RhoA-siRNA expression vector and determine its role on the malig-nant behavior of HepG2 cells.Methods A RhoA-siRNA DNA fragment was synthesized and cloned into the expression vector of pGenesil-1.The constructed Rhon-siRNA DNA plasmid was stably transfected into HerG2 cells by lipofectamine,and then HepG2 cells were divided into the HepG2/RhoA-siRNA group (HepG2 cells were transfected with pGenesil-1-RhoA-siRNA),HepG2/control group(HepG2 cells were transfected with control plasmid) and HepG2 group (without plasmid transfection).The inbibitory effect of RhoA-siRNA on RhoA protein expression was shown by Western blot.The proliferation,migration,growth potentiality and cell cycle of transfected HepG2 cells were evaluated by MTT assay,wounded healing,the plate cloning formation test and flow cytometry,respectively.All data were analyzed by one-way analysis of variance (ANOVA) and chi-square test.Results The expression of RhoA protein in the HepG2/RhoA-siRNA group was,significantly decreased compared with that in the other two groups (F=178.19,P<0.05).Scratched cells were healed within 48 hours in the HepG2/control group and HepG2 group,but not in the HepG2/RhoA-siRNA group.The clone formation rates in the HepG2/RhoA-siRNA group,HepG2 group and HepG2/control group were 39%±3%,67%±5%and 70%±6%,respectively,with a significant difference among the three groups(χ2=33.34,38.69,P<0.05).Flow cytometry showed that the number of cells transfected with RhoA-siRNA was highest in the G0/G1 phase and lowest in the S phase(F=70.46,76.57.P<0.05).Conclusion The RhoA-siRNA expression vector can effectively suppress the proliferation and migration of HepG2 cells,which may provide a novel gene therapy for hepatocellular carcinoma.     

HCCR-2反义核酸对肝癌HepG2细胞的作用

Objective To investigate the effects of antisense recombinant euraryotic expression vector of HCCR-2 on the proliferation and apoptosis of HepG2. Methods The antisense recombinant eukaryotic expression vector of HCCR-2 was constructed. The vector was stably transfected to the HepG2 cells, and positive clones were selected by G418 (antiseuse vector group), pIRES2-EGFP vector was transfected into the HepG2 cells in the same way (pIRES2-EGFP group). The conditions of the nontransfected HepG2 cells were used as control (HepG2 group). Changes in cell growth curve, cell cycle, cell apoptosis and morphology of HepG2 cells after the transfec-tion were detected by MTT method, flow cytometry and transmission electron microscopy, respectively. All the data were analyzed by one-way ANOVA and chi-square test. Results The expression level of HCCR-2 mRNA was down-regulated to 0.39±0.04 in antisense vector group, and the expression level of HCCR-2 mRNA in pIRES2-EGFP group and HepG2 group were 0.62±0.06 and 0.72±0.03, respectively, with significant difference among the 3 groups (F=43.701, P<0.05). The apoptotic rate of HepG2 cells in antisense vector group, pIRES2-EGFP grop and HepG2 group were 13.30%, 2.51% and 2.07%, respectively, with significant difference among the 3 group (χ2=6.793, 8.721, P<0.05). The growth of HepG2 cells in antisense vector group was retarded, and was blocked in G0/G1 stage. Conclusions The HCCR-2 antisense recombinant eukaryotic expression vector can inhibit the mRNA expression of HCCR-2 and promote the apoptosis of cells. HCCR-2 may be involved in cell regulation and the proliferation of hepatocellular carcinoma cells.     

Labeling of human insulin-like growth factor-I eukaryotic expression vector with green fluorescent protein

Articularcartilageinjuriesinadultsarecommon.Theintrinsicrepairisgenerallyminimalandcartilageinjuriescanfurtherdevelopintoosteoarthritis.Insulin likegrowthfactor I(IGF I)is regardedasoneofthemostimportantgrowthfactorsin cartilagedevelopmentandhomeostasis.Theadditionof IGF Itochondrocytesinvitroenhanceschondrocyte metabolism,maintainsadifferentiatedchondrocyte morphologyandpromotessynthesisofmajorcartilage matrixproteins,includingtype IIcollagenand proteoglycans.1,2IGF Iinlowconcentrationi…     

人骨形态发生蛋白—2真核表达载体的构建

目的 构建人骨形态发生蛋白－2（hBMP-2）真核表达载体,并观察其在真核细胞内表达的可能性。方法 Sal Ⅰ和Xba Ⅰ双酶切含有hBMP－2全长cDNA的pUC19,回收1.24kb片段,将其连入真核表达载体pcDNA3,构建重组子pcDNA3-hBMP-2。将重组子转化细菌,扩增后提取质粒,分别用Ecor Ⅰ和Xba Ⅰ双酶切和Xho Ⅰ单酶切后琼脂糖凝胶电泳鉴定。将重组子转染成纤维细胞,G418筛选形成阳性克隆后继续培养4周行细胞原位杂交和免疫组织化学染色。结果 琼脂糖电泳显示：用EcoR Ⅰ和Xba Ⅰ双酶切后可形成两条带,大小分别为1.3kb和5.38kb,而Xbo Ⅰ酶切位点消失,符合物理图谱,表明载体构建成功,转染后G418筛选所获阳性克隆,继续培养4周,的位杂交和免疫组织化学染色,结果表明hBMP-1基因在mRNA水平和蛋白水平均有表达。结论 成功构建hBMP-2真核表达载体,该载体可在真核细胞内表达,为将来骨损伤的基因治疗奠定了一定的实验基础。     

绿色荧光蛋白标记神经干细胞的体外研究

目的　构建携带绿色荧光蛋白 (GFP)基因的逆转录病毒载体pLNCX2 GFP ,用GFP对神经干细胞进行标记示踪。方法　应用基因克隆的方法 ,制备 pLNCX2 GFP ,借助阳离子脂质体转染包装细胞PA3 17,G418筛选阳性克隆 ,获取病毒上清 ;从胚胎大鼠脑中解剖分离和培养神经干细胞 ,用病毒上清感染大鼠胚胎神经干细胞。结果　经酶切电泳和DNA测序表明成功构建了重组GFP逆转录病毒 ,pLNCX2 GFP转染包装细胞后可以产生GFP逆转录病毒 ,病毒感染大鼠胚胎神经干细胞可以长期表达绿色荧光。结论　逆转录病毒能够快速、稳定、长期地将GFP基因转入神经干细胞 ,这种标记方法非常有利于神经干细胞移植后结构和功能的研究     

大鼠Uqcrfs1重组质粒的构建及其在HEK293T细胞中的表达

目的:构建大鼠Uqcrfs1的重组质粒并检测其在人胚胎肾293T细胞中的表达。方法:应用RT-PCR方法从大鼠肾脏组织总RNA中扩增出编码Uqcrfs1的cDNA,克隆至pUM-T载体并测序,然后亚克隆至真核表达载体pcDNA3.1/V5-His,酶切鉴定及测序正确后以磷酸钙共沉淀法瞬时转染HEK 293T细胞,使用RT-PCR、Western Blot方法检测重组质粒在转录及蛋白水平的表达。结果:测序结果证实PCR扩增得到编码Uqcrfs1的cDNA序列正确;磷酸钙共沉淀法转染HEK293T细胞后,在基因转录与蛋白表达水平,结果达到预期。结论:成功构建大鼠Uqcrfs1的重组质粒,该重组质粒可在HEK293T中过表达。     

大鼠ETFβ基因过表达对NADPH氧化酶基因表达的影响

目的:构建大鼠ETFβ的重组质粒并检测其在人胚胎肾293T细胞中的表达和对NADPH氧化酶的影响。方法:应用RT-PCR方法从大鼠肾脏组织总RNA中扩增出编码ETFβ的cDNA,克隆至pUM-T载体并测序,然后亚克隆至真核表达载体pcDNA3.1/V5-His,酶切鉴定后测序,测序正确后用磷酸钙共沉淀法瞬时转染HEK293T细胞,使用RT-PCR方法检测空载体组和重组质粒转染组的NADPH氧化酶各亚基mRNA水平的表达变化。结果:(1)测序结果证实PCR扩增得到编码ETFβ的cDNA序列正确;(2)磷酸钙共沉淀法转染HEK293T细胞后,ETFβ融合蛋白成功表达;(3)RT-PCR结果显示重组质粒转染组的NADPH氧化酶5个亚基中的NOX3,NOX4的mRNA表达降低(P<0.05),空载体组和重组质粒转染组之间比较NOX1,NOX2,NOX5的mRNA表达差异无统计学意义。结论:成功构建大鼠ETFβ的重组质粒,该重组质粒可在HEK293T中过表达,并且降低了NADPH氧化酶NOX3,NOX4的mRNA表达水平。     

荧光蛋白表达对小鼠成纤维细胞系NIH3T3体外增殖能力的影响

目的观察不同荧光蛋白表达对体外培养的小鼠成纤维细胞系NIH3T3增殖能力的影响,为细胞示踪技术提供理论依据。方法将体外扩增培养的NIH3T3细胞随机分为对照组、pLEGFP-N1组、pEGFP-N1组、pDsRed2-C1组。对照组不作任何处理,其他3组分别采用逆转录病毒载体pLEGFP-N1和真核表达载体pEGFP-N1、pDsRed2-C1两种转染方式进行增强型绿色荧光蛋白(EGFP)和红色荧光蛋白(RFP)标记,经G418筛选培养后,观察各组细胞荧光蛋白表达情况,并计算其阳性表达率;观察各组细胞贴壁率,绘制生长曲线并测定倍增时间。结果对照组NIH3T3细胞未见荧光蛋白表达;pLEGFP-N1、pEGFP-N1组均表达EFGP,pDsRed2-C1组表达RFP,而pLEGFP-N1组阳性表达率高于另外两组(P<0.01).各组细胞均有较高的贴壁率。pEGFP-N1组细胞倍增时间为(39.6±0.6)h,pDsRed2-C1组(40.3±0.7)h,pLEGFP-N1组(36.5±0.7)h,均明显晚于对照组(27.9±0.6)h(P<0.01).结论荧光蛋白表达对NIH3T3细胞体外增殖有一定程度的影响,但逆转录病毒载体抑制作用低于普通真核表达载体,可作为细胞移植时荧光蛋白标记的较好选择。     

分泌型凋亡素真核表达载体的构建及对肝癌细胞HepG2凋亡的影响

目的 构建含有NT4和HA2-TAT的分泌型VP3真核表达载体,并观察其表达对人肝癌细胞HepG2和小鼠成纤维细胞NIH3T3的影响.方法 构建了含鸡贫血病毒VP3基因和NT4、HA2-TAT基因的分泌型真核表达载体--NT4-Apoptin-HA2-TAT重组腺相关病毒载体.体外转染人肝癌细胞HepG2和小鼠成纤维细胞NIH3T3,用MTT法和流式细胞学,检测凋亡素融合基因诱导细胞凋亡的效果.结果 携带融合基因的重组腺相关病毒感染人肝癌HepG2细胞48 h后,显示了很强的诱导肿瘤细胞凋亡的能力.而对小鼠成纤维细胞NIH3T3细胞无明显凋亡作用.结论 分泌型NT4-Apoptin-HA2-TAT重组腺相关病毒载体转染细胞后能够被正常分泌、穿膜并特异性诱导肿瘤细胞凋亡,为肿瘤的基因治疗提供了新的思路.     

分泌型凋亡素真核表达载体的构建及对肝癌细胞HepG2凋亡的影响

目的 构建含有NT4和HA2-TAT的分泌型VP3真核表达载体,并观察其表达对人肝癌细胞HepG2和小鼠成纤维细胞NIH3T3的影响.方法 构建了含鸡贫血病毒VP3基因和NT4、HA2-TAT基因的分泌型真核表达载体--NT4-Apoptin-HA2-TAT重组腺相关病毒载体.体外转染人肝癌细胞HepG2和小鼠成纤维细胞NIH3T3,用MTT法和流式细胞学,检测凋亡素融合基因诱导细胞凋亡的效果.结果 携带融合基因的重组腺相关病毒感染人肝癌HepG2细胞48 h后,显示了很强的诱导肿瘤细胞凋亡的能力.而对小鼠成纤维细胞NIH3T3细胞无明显凋亡作用.结论 分泌型NT4-Apoptin-HA2-TAT重组腺相关病毒载体转染细胞后能够被正常分泌、穿膜并特异性诱导肿瘤细胞凋亡,为肿瘤的基因治疗提供了新的思路.