Construction of recombinant adeno-associated virus vector co-expressing hVEGF_(165) and hBMP_7 gene

Objective: To construct recombinant adeno-associated virus co-expressing human vascular epithelial growth factor 165(hVEGF165) and bone morphogenetic protein 7(hBMP7),measure the virus titer and verify the recombination. Methods:The AAV helper-free system was used as basis to generate recombinant AAV. The IRES sequence of plasmid pIRES was cut down and subcloned into ITR/MCS containing vector pAAV-MCS to construct recombinant plasmid pAAV-MCSa-IRES-MCSb. The hVEGF165 and hBMP7 gene was amplified by PCR and inserted into upstream MCSa and downstream MCSb respectively. Then,recombinant plasmid pAAV-hVEGF165-IRES-hBMP7,pAAV-RC and pHelper were co-transfected into AAV-293 cells to complete rAAV-hVEGF165-IRES-hBMP7 packaging. The GFP labeled rAAV-IRES-GFP was simultaneously packaged by using the parallel plasmid pAAV-IRES-hrGFP. The efficiency of AAV packaging was monitored under fluorescent microscope and recombinant viral particles were harvested from infected AAV-293 cells. The virus titer was measured by infecting AAV-HT1080 cells,and the recombinant AAV-hVEGF165-IRES-hBMP7 was verified by PCR of the exogenous interest genes. Results:Recombinant pAAV-hVEGF165-IRES-hBMP7 was verified by double digestion. GFP expression in AAV-293 could be observed under fluorescent microscope 72 h after transfection and the system provided a high packing ratio of 95%. The recombinant adeno-associated virus has a high titer of 5.5×1011vp/ml,and AAV-HT 1080 was infected at a ratio of 90%. The recombinant virus was confirmed by PCR of exogenous hBMP7 and hVEGF165 gene. Conclusion:Recombinant rAAV-hVEGF165-IRES-hBMP7 was successfully constructed with a high virus titer,which may offer foundation for in vitro and in vivo experiments of hVEGF165 and hBMP7 co-expression and provide a new method for gene therapy of bone regeneration.     

BM P-7成熟肽基因克隆及序列测定

目的 克隆人骨形态发生蛋白-7成熟肽基因。方法 根据Genebank人骨形态发生蛋白-7基因序列合成两条引物，从培养的人胎儿软骨细胞中提取mRNA，利用One step RT—PCR技术扩增出人骨形态发生蛋白-7成熟肽的基因序列，将PCR扩增产物基因片段连接克隆载体质粒中转化大肠杆菌DH5α进行克隆筛选鉴定及测序。结果 琼脂糖凝胶电泳检测RT—PCR产物显示一长约451bp的条带。阳性克隆质粒经双酶切可切出约451bp的片段，DNA测序结果与Genebank中的序列相符。结论 利用RT—PCR技术可成功的从人胎儿软骨细胞中克隆出人BMP-7成熟肽基因。     

Osteogenic potential of the human bone morphogenetic protein 2 gene activated nanobone putty

Background Nanobone putty is an injectable and bioresorbable bone substitute. The neutral-pH putty resembles hard bone tissue, does not contain polymers or plasticizers, and is self-setting and nearly isothermic, properties which are helpful for the adhesion, proliferation, and function of bone cells. The aim of this study was to investigate the osteogenic potential of human bone morphogenetic protein 2 （hBMP2） gene activated nanobone putty in inducing ectopic bone formation, and the effects of the hBMP2 gene activated nanobone putty on repairing bone defects.
Methods Twenty four Kunming mice were randomly divided into two groups. The nanobone putty ＋ hBMP2 plasmid was injected into the right thigh muscle pouches of the mice （experiment side）. The nanobone putty ＋ blank plasmid or nanobone putty was injected into the left thigh muscle pouches of the group 1 （control side 1） or group 2 （control side 2）, respectively. The effects of ectopic bone formation were evaluated by radiography, histology, and molecular biology analysis at 2 and 4 weeks after operation. Bilateral 15 mm radial defects were made in forty-eight rabbits. These rabbits were randomly divided into three groups： Group A, nanobone putty ＋ hBMP2 plasmid; Group B, putty ＋ blank plasmid; Group C, nanobone putty only. Six rabbits with left radial defects served as blank controls. The effect of bone repairing was evaluated by radiography, histology, molecular biology, and biomechanical analysis at 4, 8, and 12 weeks after operation.
Results The tissue from the experimental side of the mice expressed hBMP2. Obvious cartilage and island-distributed immature bone formation in implants of the experiment side were observed at 2 weeks after operation, and massive mature bone observed at 4 weeks. No bone formation was observed in the control side of the mice. The ALP activity in the experiment side of the mice was higher than that in the control side. The tissue of Group A rabbits expressed hBMP2 protein and higher ALP level. The ne     

HSV1-TK基因重组腺相关病毒载体的构建及表达

目的:构建含单纯疱疹病毒Ⅰ型胸苷激酶(HSV1-TK)基因的重组腺相关病毒载体质粒pSNAV2.0-TK,制备重组腺相关病毒rAAV2/HSV1-TK,并检测HSV1-TK基因在转染晶状体上皮细胞中的整合和表达,为后囊膜混浊的基因治疗奠定基础.方法:用基因重组技术构建含HSV1-TK基因的重组腺相关病毒载体质粒pSNAV2.0-TK,并通过PCR和酶切鉴定;将该质粒转染BHK-21细胞,经G418筛选出携带该质粒的载体细胞株BHK-21/TK,在辅助病毒的参与下包装成重组病毒rAAV2/HSV1-TK;用SDS-聚丙烯酰胺凝胶电泳(SDS-PAGE)法和高效液相色谱(HPLC)法检测重组病毒rAAV2/HSV1-TK的纯度,用斑点杂交法检测重组病毒的滴度;重组病毒rAAV2/HSV1-TK转染兔晶状体上皮细胞N/N1003A,用PCR和RT-PCR检测HSV1-TK基因的整合和表达.结果:经PCR和酶切鉴定重组质粒pSNAV2.0-TK构建成功;成功制备了重组病毒rAAV2/HSV1-TK,病毒滴度达1×1012v.g./mL;重组病毒转染N/N1003A细胞后,PCR和RT-PCR检测显示HSV1-TK基因在细胞中整合并且有效表达.结论:成功构建了含HSV1-TK基因的重组腺相关病毒载体质粒,制备了高滴度重组病毒rAAV2/HSV1-TK,HSV1-TK基因在转染该病毒的晶状体上皮细胞中可有效表达.     

表达人骨形成蛋白2的成纤维细胞系的建立与鉴定

目的:建立能稳定表达BMP2的成纤维细胞系.方法:运用阳离子聚合物转染试剂,将含有人BMP2基因的真核表达载体pcDNA3.1-B2导入NIH3T3细胞,通过G418筛选获得阳性细胞克隆,RT-PCR、免疫组化和酶联免疫吸附试验(ELISA)检测BMP2基因的稳定转染和蛋白表达.结果:转染细胞内有BMP2mRNA的转录,胞内及胞外有BMP2蛋白的表达.结论:采用阳离子聚合物转染法可成功地将外源性hBMP2基因导入NIH3T3细胞,为进一步研究诱导牙周膜细胞骨化分化建立基础.     

重组人骨形成蛋白2基因在大肠杆菌中的克隆

目的：在大肠杆菌中克隆人骨形成蛋白2基因,方法：由人成骨细胞中提取细胞总RNA,利用逆转录PCR方法扩增获得人骨形成蛋白2基因cDNA;将获得基因片段重组到pCI质粒中,转化到大肠杆菌Top10后挑选克隆,利用限制性酶切和核苷酸序列分析鉴定重组质粒。结果：质粒DNA酶切分析及核酸序列分析证实,获得的基因片段为人BMP2全编码序列,结论：克隆获得人骨形成蛋白2基因,为表达骨形成蛋白2奠定了基础。     

Construction of adeno-associated virus coexpression system for human angiopoietin-1 and VEGF gene

Background Ischemic disease is one of the leading causes of death in the world. In order to further study gene therapy for ischemic disease, we constructed a recombinant plasmid for co-expression of human angiopoietin-1 and vascular endothelial growth factor 165 (VEGF165) gene in adeno-associated virus (AAV) gene delivery system.Methods Human angiopoietin 1 and VEGF165 gene were obtained using PCR. The upstream of angiopoietin 1 contained restriction enzyme site Hind Ⅲ,contained restriction enzyme site BamH Ⅰ. The upstreamand the downstream of angiopoietin 1 of VEGF165 contained restriction enzyme site Bgl Ⅱ, and the downstream of VEGF165 contained restriction enzyme site BamH Ⅰ, Using the multiple cloning sites (MCS) in plasmid pZero such as BamH Ⅰ , Bgl Ⅱ, Hind Ⅲ, Not Ⅰ , Xho Ⅰ ,Xba Ⅰ , Sal Ⅰ , BspH Ⅰ , Ksp Ⅰ and the corresponding MCS in plasmid pAAV-MCS, angiopoietin 1 and VEGF165 gene were subcloned into pAAV-MCS.Results DNA sequencing revealed that the PCR- amplified angiopoietin 1 and VEGF165 were consistent with NCBI Gene Bank. The recombinant plasmid was identified using PCR and digestion,which proved to be consistent with our hypothesis. In recombinant plasmid, angiopoietinl and VEGF possessed a CMV promoter and polyA terminator system respectively, thus assuring co-expression of the two genes.Conclusion Successful construction of AAV co-expression system for human angiopoietin 1 and VEGF165 gene will provide the foundation for gene therapy to cure severe ischemic disease.     

重组人骨形成蛋白－2与异种骨复合移植的扫描电镜观察

目的：明确含有重组人骨形成蛋白－２（ｒｈＢＭＰ－２）的新型复合异种骨的骨修复能力。方法：将ｒｈＢＭＰ－２与经综合化学处理的新生小羊骨松质（ＣＢ）结合，制备成复合异种骨．将复合异种骨植人兔下颌骨缺损，并以单纯松质骨移植、自体骨移植作为对照组，术后２、４、８、１２周分别取材做扫描电镜观察。结果：复合异种骨移植后，植骨区有大量新骨形成，新骨的量随移植时间延长而逐渐增多。自体骨移植组扫描电镜下表现与复合异种骨组基本相同。而单纯骨松质载体移植后，植入区多为纤维结缔组织，新骨形成少．结论：ｒｈＢＭＰ－２可显著促进复合异种骨内的新骨形成。这种新型复合异种骨可能是一种较理想的植骨材料，可望用于人体植骨     

BMP-7/GFP融合基因在人肾小管上皮细胞的表达与定位

目的 构建骨成形蛋白-7(BMP-7)／绿色荧光蛋白(GFP)融合基因，观察其在人肾小管上皮细胞的表达与定位。方法 将小鼠BMP-7全长eDNA与GFP融合，连接进入真核细胞表达质粒pEGFP-C1中，以脂质体介导的方法将重组表达质粒pEGFP-C1-BMP-7转染入人肾小管上皮细胞。采用Western blot方法检测BMP-7在肾小管上皮细胞的表达；激光共聚焦荧光显微镜观察BMP-7在人肾小管上皮细胞中的定位情况。结果 限制性酶切以及DNA测序结果均说明所构建的重组质粒为BMP-7／GFP融合基因表达质粒。瞬时转染入肾小管上皮细胞BMP-7蛋白表达量较空载体转染组明显增加；GFP转染的细胞荧光均匀分布在整个细胞中，而pEGFP-C1-BMP-7转染的细胞荧光主要集中在细胞浆和细胞膜表面。结论 重组BMP-7／GFP融合蛋白具有GTP自发荧光的特性，且不影响BMP-7在细胞内的正确表达。     

重组腺相关病毒载体介导的绿色荧光蛋白在急性髓性白血病患者骨髓间充质干细胞中的表达

目的 探讨重组腺相关病毒载体(rAAV-2-eGFP)是否可高效转导入骨髓间充质干细胞(BMSCs)。方法 从初发的急性髓性白血病(AML)患者骨髓中分离培养出BMSCs,在不同的感染复数(MOI =102, 103, 104, 105, 106,107)下用包含增强型绿色荧光蛋白(eGFP)的rAAV-2-eGFP感染BMSCs,寻找最佳的感染条件,并在转染后的不同时间点用倒置荧光显微镜以及流式细胞仪观察其表达情况。结果 转染后10~14 d, eGFP在BMSCs中表达,转染效率为0.3%~2%,增加MOI亦不能明显增加转染效率。在MOI=105的条件下转染后观察了61 d, eGFP保持低水平长期稳定表达,在转染后的12~ 33 d,eGFP阳性的BMSCs从起始时的1.16%下降到(0.5~0.6)%,33~61 d一直维持在这一水平。结论 rAAV-2-eGFP和BMSCs可用于体外基因治疗,但极低的转染效率可能是其进一步应用的障碍。     

骨形成蛋白体外对培养的人牙髓组织的诱导作用

骨形成蛋白可促进牙髓细胞增殖的诱发修复性牙本质形成，作应用体外组织培养技术，分别通过光镜和透射电镜观察了牛骨形成蛋白对体外培养的人牙髓组织的诱导作用，结果发现，培养３ｄ后可见增殖的星形细胞，其胞浆少，细胞小器不发达，培养７ｄ后，可见透明基质中埋有一些软骨样细胞，该细胞胞浆丰富，细胞小器发达，并含有丰富的分泌小泡，说明骨形成蛋白可促进牙髓细胞从低分化状态向高分化状态分化。     

人骨形成蛋白7基因的克隆及其在兔骨髓基质干细胞中的瞬时表达

目的克隆人骨形成蛋白7(BMP-7基因,并构建其真核表达载体,观察其在兔骨髓基质干细胞(rBMSC)中的表达并探讨其应用于骨科局部基因治疗的可能性.方法用RT-PCR法从人胎肾组织中克隆人BMP-7基因全长cDNA并测序.将BMP-7基因cDNA克隆到穿梭载体pShuttle中构建表达载体pShuttle-BMP-7,经鉴定后利用LipofectAMINE2000瞬时转染rBMSC,用RT-PCR方法及免疫组化检测BMP-7基因的表达.结果用RT-PCR法从胎肾组织中克隆出1296 bp的cDNA,测序证实为人BMP-7基因.RT-PCR方法及免疫组化检测证实其能在rBMSC中表达.结论成功克隆人BMP-7基因并证实其在rBMSC的表达,为下一步腺病毒介导的局部基因治疗打下基础.     

hBMP-7基因转染对骨髓间充质干细胞增殖和碱性磷酸酶合成的影响

目的探讨逆转录病毒介导的人骨形态发生蛋白7(humanbonemorphogeneticprotein7,hBMP-7)基因转染对兔骨髓间充质干细胞(bonemarrowmesenchymalstemcell,BMSc)增殖和向成骨细胞分化的影响。方法构建hBMP-7逆转录病毒载体,使用含目的基因的病毒液感染BMSc,免疫组织化学方法检测hBMP-7蛋白的表达,MTT法检测细胞增殖能力,使用流式细胞仪检测细胞周期,NPP法检测碱性磷酸酶合成情况。结果经BMP-7基因转染的兔BMSc有hBMP-7的阳性表达,增殖能力无明显改变(P>0.05),但其合成碱性磷酸酶的能力得到显著提高,与空载体病毒液转染、未经转染的BMSc相比差异有显著性(P<0.01)。结论经BMP-7基因转染的BMSc能够表达外源BMP-7,hBMP-7基因转染能够促进体外培养的BMSc向成骨细胞转化,可用于以BMSc为种子细胞的组织工程化骨组织的构建。     

骨形态发生蛋白7改善糖代谢的作用及其机制

目的 探索骨形态发生蛋白7(bone morphogenetic protein 7,BMP7)对2型糖尿病小鼠糖代谢的影响及其机制.方法 将8周龄雄性C57BL/6小鼠,采用小剂量链脲佐菌素注射联合高脂喂养建立2型糖尿病小鼠模型.将建模成功的小鼠分为4组(n=20)∶2型糖尿病模型组,PBS对照组(PBS腹腔注射),BMP7低剂量组(BMP7,100 μg/kg,隔日腹腔注射),BMP7高剂量组(BMP7,200 μg/kg,隔日腹腔注射).4周后,分别检测血糖、血总胆固醇、甘油三酯、血清胰岛素水平、体质量的变化,并计算胰岛素分泌指数HOMA-β和胰岛素抵抗指数HOMA-IR.取小鼠胰腺,Western blot检测蛋白激酶D1(protein kinase D1,PKD1)及磷酸化PKD1的表达变化.结果 与2型糖尿病模型组和PBS对照组相比,BMP7高剂量组和低剂量组的血糖、甘油三酯均明显降低(P＜0.05),而血清胰岛素水平、HOMA-β均显著升高(P＜0.05).BMP7低剂量组和BMP7高剂量组的体质量均低于对照组(P＜0.05),BMP7高剂量组的HOMA-IR低于对照组(P＜0.05).Western blot检测发现BMP7处理组的PKD1蛋白表达量与对照组相比差异均无统计学意义(P＞0.05),但磷酸化PKD1水平均明显升高(P＜0.05).结论 BMP7可以促进2型糖尿病小鼠的胰岛素分泌和改善其胰岛素敏感性,从而降低血糖,其改善胰岛素分泌作用可能与增加PKD1磷酸化有关.     

逆转录病毒介导人重组骨形态发生蛋白基因转染骨骼肌卫星细胞mRNA的表达

目的探讨逆转录病毒介导重组人骨形态发生蛋白7(recombinant human bone morphogenetic protein 7, rhBMP7)基因转染骨骼肌卫星细胞的可行性及目的基因的表达情况。方法体外获取和培养大鼠骨骼肌卫星细胞,构建rhBMP7逆转录病毒载体,利用脂质体介导的基因转移技术转染包装细胞PT67,经G418筛选后,制备含目的基因的重组逆转录病毒液,病毒液感染骨骼肌卫星细胞,使用RT-PCR方法检测rhBMP7 mRNA的表达情况。结果成功地构建了逆转录病毒真核表达载体,逆转录病毒介导rhBM7基因转染的骨骼肌卫星细胞能有效地表达外源性rhBMP7 的mRNA。结论采用逆转录病毒介导的方法可将rhBMP7转染至骨骼肌卫星细胞中,目的基因可在mRNA水平有效表达。     

稳定表达人骨形成蛋白2成纤维细胞的建立与鉴定

目的 探讨ＢＭＰ对细胞分化的调节作用,为ＢＭＰ基因疗法的建立提供依据。方法 构建了含有人ＢＭＰ２开放阅读框（１．２ｋｂ）的真核表达载体ｐＢＫ－Ｂ２利用脂质本转染方法将其导入ＮＩＨ３Ｔ３细胞,通过Ｇ－４１８筛选获得了性细胞克隆,细胞原位杂交和免疫组化检测ＢＭＰ２基因的稳定转染及表达情况。结果 转染细胞内有ＢＭＰ２ｍＲＮＡ的转录及其蛋白的表达,结论：人ＢＭＰ２基因ＮＩＨ３Ｔ３细胞中得到稳定有效的方法。     

Inductive effect of bovinc bone morphogenetic protein on human dental pulp tissue in vitro

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人骨形态发生蛋白-2基因腺病毒载体异位成骨

目的：评价人骨形态发生蛋白2(hBMP-2)基因腺病毒表达载体(recombinant adenoviral vector carrying the human BMP-2 gene, AdBMP-2)成骨能力并探讨其成骨机制。方法：应用 AdBMP-2体外感染兔骨髓间质干细胞（BMSC），7 d后观察hBMP-2和碱性磷酸酶(ALP)的表达,21 d后观察感染细胞钙结节形成能力。同时将AdBMP-2行裸鼠腓 肠肌组织内注射，术后20 d取材，观察hBMP-2的表达及肌组织内异位成骨情况。结果：AdBMP-2可高效感 染BMSC并获得hBMP-2的有效表达，ALP表达增高并形成钙结节。AdBMP-2在体内同样表达hBMP-2， 并且以软骨化骨的方式启动成骨。结论：感染AdBMP-2的BMSC向成骨细胞分化，AdBMP-2在体内有着良好的成骨能力。     

rAAV2载体介导GFP基因转染树突状细胞

目的:在诱导人骨髓CD34 细胞分化成树突状细胞(dendritic cells,DCs)的基础上,探讨2型重组腺相关病毒(Type 2 recombinant adeno-associated virus,rAAV2)载体介导绿色荧光蛋白(green fluorescent protein,GFP)基因转染DCs的条件.方法:采用免疫磁珠法分离纯化人骨髓来源的CD34 细胞.在含有IL-4和GM-CSF的培养体系中体外诱导CD34 细胞生成DCs,于第5天加入TNF-α诱导DCs成熟,在不同时间用rAAV2载体介导GFP基因转染未成熟和成熟的DCs.通过电子显微镜和流式细胞仪鉴定树突状细胞,荧光显微镜及流式细胞仪检测GFP的表达.结果:人骨髓CD34 细胞经诱导分化后,在光镜及透射电镜下均可观察到DCs的形态特征,流式细胞仪检测到DCs表型;荧光显微镜及流式细胞仪检测细胞培养第3天、第5天和加入TNF-α后的rAAV2-GFP转染率分别为0.45%,13.54%和0.25%.结论:本实验中所采用的培养体系可成功将人骨髓CD34 细胞诱导分化成DCs,rAAV2/GFP转染DCs效率随细胞诱导分化时间的延长而增高,且转染未成熟DCs的效率高于转染成熟DCs.