人端粒酶逆转录酶慢病毒载体的构建及人肝细胞的初步筛选

目的： 构建人端粒酶逆转录酶（hTERT）慢病毒表达载体,将其转染人肝细胞L02并且通过杀稻瘟筛选出阳性克隆细胞。方法：以PBABE-puro-hTERT质粒为模板PCR法获取目的基因attB1- hTERT-attB2,通过BP反应克隆至pDONR221;采用LR重组酶将pDONR221-hTERT和pLenti6/V5-DEST进行重组反应,形成pLenti6/V5-DEST- hTERT。将重组载体pLenti6/V5-DEST- hTERT与包装质粒充分混合,利用脂质体共转染293FT细胞,获得重组慢病毒颗粒。将其感染人肝细胞L02,通过杀稻瘟筛选获得阳性克隆。结果：测序发现入门载体pDONR221包含的目的基因hTERT 1547位点存在点突变(原碱基A变成G）,通过定点突变技术成功诱变并鉴定慢病毒表达载体pLenti6/V5-DEST- hTERT成功构建。重组慢病毒滴度为1×108 TU/L,获得20株稳定抗性的单克隆细胞。结论：成功构建人端粒酶逆转录酶的慢病毒表达载体,获得稳定抗性的单克隆肝细胞,为进一步建立永生化肝细胞系奠定了基础。     

线粒体细胞色素C氧化酶RNAi慢病毒载体的构建

目的：通过构建携带细胞色素C氧化酶基因的RNAi慢病毒载体，获得可供转染的滴度，为下一步研究该基因缺陷在真核细胞中的影响提供物质基础。 方法： 根据线粒体细胞色素C氧化酶设计的两条互补的单链寡核苷酸退火后形成双链，插入到pENTR/U6质粒缺口末端，连接在质粒上生成含RNAi盒的pENTR/U6载体；通过重组作用将pENTR/U6载体的RNAi盒重组到pLenti6/BLOCK-iT-Dest 载体上,构建含U6启动子、靶序列和Pol Ⅲ终止子表达框的MTCOX-I shRNA表达重组体；经脂质体导入293FT细胞，包装成慢病毒，收集病毒上清并检测其滴度。Western blotting检测干扰后细胞内线粒体细胞色素C氧化酶I亚基的表达。 结果： 将目的序列成功连接到载体上，并经测序分析证实载体构建成功；成功包装成高滴度的慢病毒。Western blotting检测结果证实构建的MTCOX-I shRNA表达重组体可显著抑制线粒体细胞色素C氧化酶I亚基的表达。 结论： 成功构建了携带细胞色素C氧化酶基因的RNAi慢病毒载体。     

人Hes1-shRNA,Hes5-shRNA慢病毒表达载体的构建、包装及鉴定

目的 构建人Hes1-shRNA和Hes5-shRNA慢病毒表达载体,为Notch-Hes信号通路的相关研究奠定基础.方法 根据人Hes1,Hes5基因mRNA序列分别设计、合成多对互补的DNA单链寡核苷酸,退火后克隆至pENTR /U6入门载体.通过入门载体瞬时转染神经胶质瘤U251细胞筛选有效干扰序列.将含有效干扰序列的入门载体与pLenti6/BLOCK-iT-DEST载体进行LR重组构建Hes1-shRNA和Hes5-shRNA慢病毒表达载体,经脂质体介导入293FT细胞,包装成慢病毒.用该慢病毒感染U251细胞,Western印迹法分别检测Hes1,Hes5蛋白的表达.结果 分别构建了针对Hes1和Hes5基因的特异性shRNA慢病毒表达载体,其包装获得慢病毒可有效感染U251细胞并分别对Hes1,Hes5蛋白的表达有显著抑制作用.结论 成功构建了Hes1-shRNA和Hes5-shRNA慢病毒表达载体.     

胞嘧啶脱氨酶和血管内皮抑素基因慢病毒载体的构建与鉴定

目的 构建携带胞嘧啶脱氨酶(CD)和血管内皮抑素(ES)基因的慢病毒载体.方法 根据GenBank提供大肠杆菌源CD和ES基因序列设计、合成2个基因并构建与荧光蛋白融合的真核表达载体pEGFP-CD和pDS-RED-ES.酶切和测序鉴定后,将载体瞬时转染HEK293细胞,运用实时PCR检测CD和KS基因表达情况.把载体中基因片段EGFP-CD和DS-RED-ES通过BP/LR重组分别构建慢病毒载体,并利用293FT细胞进行慢病毒的包装.将病毒原液浓缩,并测定病毒滴度.结果 酶切、测序及PCR鉴定证实构建出慢病毒载体pLenti6.3-CD-EGFP和pLenti6.3- ES- Monomer - DsRed.感染293FT细胞后荧光显微镜下观察到GFP和DsRed的表达.浓缩慢病毒滴度分别为2.2× 108 TU/ml和6.5×107 TU/ml.结论 成功构建了CD和ES基因慢病毒载体.     

构建携带重组人胰岛素基因慢病毒表达载体及其病毒包装

背景:腺病毒载体作为脂肪组织工程转基因载体,在应用中存在转导细胞免疫排斥及炎症反应等问题。应用慢病毒作为载体转染干细胞尤其是应用含胰岛素基因的慢病毒载体转染干细胞可避免腺病毒载体的诸多问题。目的:实验拟构建含有人重组胰岛素(insulin)与增强型绿色荧光蛋白(enhanced green fluorescent protein,EGFP)基因慢病毒表达载体pLenti6.3-insulin-IRES-EGFP,并进行病毒颗粒包装。方法:应用聚合酶链反应方法获得目的基因,在目的基因上、下游分别加上BamHⅠ,AscⅠ两个酶切位点,进行T载体克隆,转化入感受态DH5α细胞中,通过筛选获得重组质粒。用限制性内切酶酶切,将目的基因片段和pLenti6.3-IRES-EGFP载体连接,转化入感受态DH5α细胞中,通过筛选获得慢病毒表达载体pLenti6.3-insulin-IRES-EGFP,并进行测序。抽提慢病毒载体,转染293T细胞,包装病毒,测定病毒滴度。结果与结论:通过聚合酶链反应获得长度为347bp带有BamHⅠ和AscⅠ序列的目的基因。pMD18-T载体和慢病毒表达载体pLenti6.3-IRES-EGFP连接,慢病毒表达载体pLenti6.3-insulin-IRES-EGFP构建与预期相匹配,成功包装慢病毒颗粒。     

携eGFP及表达人gp100-TCR基因的慢病毒表达载体的构建与鉴定

目的构建携eGFP的人gp100-TCR基因慢病毒表达载体。方法应用基因重组手段,从pGCsamgp100APB质粒上扩增出人gp100-TCR片段,将其插入到pLentiLox3.7(pLL3.7)慢病毒表达载体中,同时将其U6启动子替换为EF-1a启动子,形成慢病毒表达载体pLL3.7-gp100TCR-pEf-1a。将其与包装质粒混合,采用磷酸钙转染法转染293FT细胞,包装产生慢病毒,荧光显微镜观察GFP蛋白的表达水平。检测病毒滴度。结果 PCR、酶切及测序表明慢病毒表达载体pLL3.7-gp100TCR-pEf-1a构建成功。转染后的293FT细胞在荧光显微镜观察可见强绿色荧光,形成的慢病毒可感染293FT细胞,包装的慢病毒浓缩后滴度为4.5×106 TU/ml。结论成功构建eGFP和gp100-TCR共同表达的慢病毒表达载体,为gp100-TCR在肿瘤治疗中的功能研究提供了有效平台。     

Nesprin基因RNAi慢病毒载体的构建

背景：Nesprin蛋白缺失将影响细胞骨架组织和动态平衡,引起细胞骨架刚性丧失或导致细胞过早成熟老化,其对间充质干细胞的作用如何？ 目的：构建Nesprin蛋白siRNA慢病毒载体,并转染骨髓间充质干细胞。 方法：针对Nesprin靶基因序列设计并合成4对miRNA oligo,将4种miRNA干扰质粒转入大鼠血管平滑肌细胞,筛选最有效干扰序列;将最佳干扰序列和pDONR221载体进行重组反应,获得含干扰序列的入门载体,再将入门载体和慢病毒表达目的载体pLenti6/V5-DEST进行重组反应,获得含干扰序列的慢病毒表达载体,转染包装细胞293T细胞,包装慢病毒,以293T细胞GFP蛋白水平测定病毒滴度。慢病毒转染大鼠骨髓间充质干细胞。 结果与结论：测序证实合成的4对miRNA oligo正确,RT-PCR和western-blot筛选出最佳干扰miRNA质粒为SR-3,成功构建了Nesprin siRNA的慢病毒载体LV-siNesprin。包装慢病毒,浓缩病毒悬液的活性滴度为10⁶ TU/mL。慢病毒成功了转染骨髓间充质干细胞细胞。     

携人PTHLH基因慢病毒表达载体的构建

目的构建携带人甲状旁腺相关激素（PTHLH）基因的慢病毒表达载体pGC-FU/PTHLH。方法酶切载体pGC-FU,根据人PTHLH基因合成特定引物,扩增目的基因片段,将其克隆到pGC-FU质粒（含EGFP基因）上,菌落PCR鉴定及测序分析重组载体,使用Lipofectamine 2000诱导转染pGC-FU、pHelper1.0和pHelper2.0载体三质粒进入293T细胞包装慢病毒,并用带PTHLH的慢病毒感染293T细胞和鼻咽癌CEN1细胞确认慢病毒包装是否成功。结果菌液PCR产物琼脂糖凝胶电泳鉴定显示,与理论预计值阳性转化子735bp,阴性转化子198bp基本相吻合;PCR鉴定阳性的克隆进行测序和比对分析,结果完全匹配,进一步鉴定载体构建成功。分别将质粒包装系统共转染293T细胞,包装产生空白对照慢病毒（pGC-FU）和过表达PTHLH的慢病毒（pGC-FU/PTHLH）;或用携带PTHLH和EGFP基因的病毒上清感染CNE1细胞,48h后,倒置荧光显微镜下观察293T和CNE1细胞,均可见绿色荧光,转染成功。结论成功构建携人PTHLH基因慢病毒表达载体,为进一步研究PTHLH基因在鼻咽癌转移中的作用及鼻咽癌发病分子机制奠定了基础。     

构建人端粒酶催化亚单位基因慢病毒表达载体转染人骨髓基质细胞

背景：骨髓基质细胞不表达端粒酶,因而在体外传代扩增过程中端粒长度逐渐缩短,导致细胞衰老,这是限制其用于细胞治疗应用的一个重要因素。 目的：构建人端粒酶催化亚单位基因慢病毒表达载体,探讨以慢病毒介导的人端粒酶催化亚单位基因修饰人骨髓基质细胞的可行性。 方法：以pReceiver-M02-hTERT质粒为模板PCR扩增获得目的基因。用BP重组系统将目的片段重组到载体pDONR221上。然后使用LR重组系统将目的序列重组到载体pLenti6.3/V5-DEST上。将重组载体与包装质粒充分混合,利用脂质体共转染293FT细胞获得慢病毒颗粒。 结果与结论：成功构建人端粒酶催化亚单位慢病毒表达载体,病毒的平均物理滴度为1.07×10¹² LP/L。以之转染人骨髓基质细胞,目的基因表达水平有显著提升,细胞正确表达人端粒酶反转录酶蛋白。说明以慢病毒介导的人端粒酶催化亚单位基因修饰人骨髓基质细胞能强化细胞表达人端粒酶催化亚单位。     

人EGFL7基因RNA干扰慢病毒载体的构建及其在人喉癌细胞中的表达

 目的：构建人表皮生长因子样结构域7（epidermal growth factor-like domain 7, EGFL7）基因RNA干扰（RNA interference, RNAi）慢病毒表达载体,并建立稳定干扰EGFL7基因表达的喉癌细胞亚系,为研究EGFL7蛋白在喉癌发生发展中的功能奠定基础。方法：针对人EGFL7基因序列,设计特异性RNAi靶序列,与pcDNA6.2-GW/EmGFP-miR线性载体定向连接,得到的阳性重组子再与pLenti6.3-MCS/V5-DEST慢病毒载体进行重组,获得真核表达慢病毒干扰载体。在POLOdelivererTM 3000介导下将慢病毒包装质粒和EGFL7基因重组慢病毒载体导入293T细胞包装病毒,测定病毒滴度,感染人喉癌细胞HEp-2,杀稻瘟菌素筛选获得稳定干扰EGFL7基因的细胞亚系。结果：成功构建EGFL7 pLenti6.3-EGFL7-miR真核表达慢病毒干扰载体并获得相应慢病毒,经测定病毒滴度为5×1011 TU/L,实时荧光定量PCR证实pLenti6.3-EGFL7-miR慢病毒载体对喉癌细胞HEp-2 EGFL7基因的沉默效率为97%。结论：成功构建人EGFL7基因特异性的慢病毒干扰载体,并获得EGFL7基因稳定干扰的喉癌细胞亚系。     

胱硫醚合酶基因及其在人群中的多态性

胱硫醚合酶的活性降低或丧失是心脑血管系统等系统疾病独立的危险因子或易感因素.目前研究发现使酶活性降低或丧失的胱硫醚合酶基因的变异在人群中存在多态性.     

eNOS基因和MTHFR基因多态性与子痫前期发病关系的研究

目的探讨内皮型一氧化氮合酶(eNOS)基因第7外显子G894T突变和N5,N10-亚甲基四氢叶酸还原酶(MTHFR)基因C677T突变与子痫前期的关系。方法应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术,对53例子痫前期患者(子痫前期组)和49例正常妊娠妇女(对照组)的eNOS基因G894T突变和MTHFR基因C677T突变进行检测。结果子痫前期组eNOS基因Glu/Glu、Glu/Asp、Asp/Asp基因型频率分别为71.7%、28.3%、0.0%;MTH-FR基因CC、CT、TT基因型频率分别为22.7%、39.6%、37.7%。对照组eNOS基因Glu/Glu、Glu/Asp、Asp/Asp基因型频率分别为83.7%、16.3%、0.0%;MTHFR基因CC、CT、TT基因型频率分别为20.4%、61.2%、18.4%。子痫前期患者TT基因型频率(37.7%)显著高于对照组(18.4%)(P<0.05),而CT基因型频率子痫前期组(39.6%)显著低于对照组(61.2%)(P<0.05),而eNOS基因型和等位基因频率两组比较差异均无显著性(P>0.05)。携带TT基因型个体发生子痫前期的风险增加2.69。结论eNOS基因G894T突变与子痫前期发病无关;MTHFR基因TT基因型能增加子痫前期的患病风险;eNOS基因和MTHFR基因在子痫前期发病中无协同作用。     

载体与基因转染的研究进展

基因载体是指将基因或其它核酸物质运载到细胞中的工具.其化学本质可以是蛋白质或多肽、核酸、脂类、糖类、其它有机分子或它们的复合物.基因传递系统是基因治疗的重要组成部分,也是目前基因治疗的瓶颈.现有的基因载体包括两类.即病毒载体和非病毒载体.病毒载体转染效率高,但由于其转染具有免疫原性和致突变性限制了它的应用;非病毒载体系统具有低毒、低免疫原性和相对靶向性等优点,是新兴发展起来的基因转移系统.就各种载体的最新研究进展作一综述.     

Correlations between gene expression and gene conservation in fission yeast

Genes can be expressed at a wide range of levels, and they show different degrees of cross-species conservation. We compared gene expression levels to gene conservation by integrating microarray data from fission yeast (Schizosaccharomyces pombe) with lists of "core" genes (present in worm and budding and fission yeasts), "yeast-specific" genes (present in budding and fission yeasts, but not in worm), and "pombe-specific" genes (present in fission yeast only). Whereas a disproportionate number of core genes are highly expressed in vegetatively growing cells, many pombe-specific genes are expressed at lower levels. This bias is less pronounced in cells undergoing sexual development, when many pombe-specific genes become highly expressed. This implies that organism-specific proteins are more likely to function during specialized processes such as cellular differentiation. Accordingly, pombe-specific genes were overrepresented among genes induced during sexual development; they were particularly enriched in a group of genes induced during meiotic prophase, when homologous chromosomes pair and recombine. This raises the possibility that organism-specific genes with functions in meiotic prophase favor speciation by preventing fruitful meiosis between closely related organisms. Finally, the set of genes induced late during sexual differentiation, at the time of spore formation, was enriched in yeast-specific genes, indicating that these genes play specialized roles in ascospore development.     

Gene- and evidence-based candidate gene selection for schizophrenia and gene feature analysis

ObjectiveSchizophrenia is a chronic psychiatric disorder that affects about 1% of the population globally. A tremendous amount of effort has been expended in the past decade, including more than 2400 association studies, to identify genes influencing susceptibility to the disorder. However, few genes or markers have been reliably replicated. The wealth of this information calls for an integration of gene association data, evidence-based gene ranking, and follow-up replication in large sample. The objective of this study is to develop and evaluate evidence-based gene ranking methods and to examine the features of top-ranking candidate genes for schizophrenia.MethodsWe proposed a gene-based approach for selecting and prioritizing candidate genes by combining odds ratios (ORs) of multiple markers in each association study and then combining ORs in multiple studies of a gene. We named it combination–combination OR method (CCOR). CCOR is similar to our recently published method, which first selects the largest OR of the markers in each study and then combines these ORs in multiple studies (i.e., selection–combination OR method, SCOR), but differs in selecting representative OR in each study. Features of top-ranking genes were examined by Gene Ontology terms and gene expression in tissues.ResultsOur evaluation suggested that the SCOR method overall outperforms the CCOR method. Using the SCOR, a list of 75 top-ranking genes was selected for schizophrenia candidate genes (SZGenes). We found that SZGenes had strong correlation with neuro-related functional terms and were highly expressed in brain-related tissues.ConclusionThe scientific landscape for schizophrenia genetics and other complex disease studies is expected to change dramatically in the next a few years, thus, the gene-based combined OR method is useful in candidate gene selection for follow-up association studies and in further artificial intelligence in medicine. This method for prioritization of candidate genes can be applied to other complex diseases such as depression, anxiety, nicotine dependence, alcohol dependence, and cardiovascular diseases.     

FHIT基因研究进展

早在1979年，Cohen等就发现一家族性早发、双侧、多灶的肾透明细胞癌与t(3：8)染色体易位有关。此后，人们在肺癌、食管癌、胃癌、乳腺癌等多种肿瘤组织中观察到3号染色体短臂的高频率缺失，提示在3p上可能存在抑癌基因。1996年，Ohta等用差异显示分析探针和外显子捕获法在3p14、2上确定了一个新的基因，     

Hypertension and gene polymorphisms

For our understanding of the genetic factors of human essential hypertension, gene polymorphisms have played a significant role as DNA markers in association and linkage studies. We found positive linkages between hypertension and 4 gene polymorphisms including angiotensinogen Met235Thr, angiotensin converting enzyme I/D, aldosterone synthase CYP11B2 T-344C, and endothelial nitric oxide synthase Glu298Asp in the Aomori population. These results suggest that the 4 gene polymorphisms might be genetic risk factors for hypertension in this district. However, there has been a frustration with the inconsistencies of accumulated evidence. Because, the genetic associations tend to vary across race, ethnicity, and ecological states. Thus, the rates of racial inter-mixture can explain regional differences in disease susceptibility. We emphasize that human lineage based analysis across populations may lead to the better understanding of the variability.     

Introns and gene evolution

In one scenario of gene evolution, exon shuffling has a fundamental role in increasing gene diversity. As DNA sequences accumulate in the databases, the picture of the intron/exon structures of genes becomes more and more clear. We discuss in this review some features of this picture that suggest that introns have been present since the early stages of evolution, and that exon shuffling was a fundamental process in the construction of ancient as well as modern genes.