人血小板因子4基因cDNA的克隆与序列测定

为研究人血小板因子4（hPF4)的生物学性能和用于肿瘤生物治疗的可能性,运用反转录聚合酶链反应（RT－PCR）从人工白血病细胞系HEL细胞总RNA中扩增出hPF4基因cDNA序列,将其克隆至pUC18载体中。序列分析证实克隆片段与献报道的hPF4基因cDNA序列完全一致,说明已成为克隆到hPF4基因cDNA。     

筛选代表小鼠植入前胚胎紧密化相关基因的EST

分别收集181及241枚昆明白小鼠8细胞早期胚胎及8细胞紧密化胚胎,采用SMART PCR方法直接合成胚胎双链cDNA.进而运用抑制消减杂交技术(SSH)对8细胞早期胚胎及8细胞紧密化胚胎的基因表达进行研究,并将所获得的差异表达产物按片段大小分段分离纯化后克隆入pUCm-T载体中,经PCR鉴定后挑选阳性克隆进行测序,筛选出27个代表8细胞早期胚胎和紧密化8细胞胚胎差别表达基因的cDNA片段;经与GenBank中收录的序列进行同源性匹配分析,证实其中17个eDNA片段为新的EST,提交GenBank后被接受并给予了新序列编号.这1 7个片段均可能为与紧密化密切相关的新基因的表达片段,为今后进一步克隆新的紧密化相关基因的全长cDNA及后续新基因的结构和功能研究打下基础.通过采用不同长度大小片段分别克隆的方法,可获得较长片段的EST,避免差异表达大片段的丢失.     

人AADC基因在cos-7细胞中的表达和活性检测

目的　研究人芳香族左旋氨基酸脱羧酶 (AADC)基因在多巴胺代谢过程中的作用。方法　从人胎儿黑质组织中提取总RNA ,以RT PCR法扩增AADCcDNA片段 ,克隆于 pGEM T载体中。测序正确后再构建真核表达载体 ,转染猴肾成纤维细胞COS 7,原位杂交检测AADC表达 ,加入L DOPA后 ,用高效液湘色谱测定转AADC细胞的多巴胺(DA)生成量 ,以了解转基因细胞AADC基因的功能活性。结果　RT PCR扩增出 144 2bp的cDNA片段与Genbank[NM 0 0 0 790 ]登录的序列相同 ,构建真核表达载体 pBK RSV AADC ,原位杂交证实其在COS 7表达阳性率为 70 % - 80 % ,在AADC活性作用下实验组的DA生成量是对照组的 4倍以上 (P <0 0 1)。结论　所克隆的AADC基因可在真核细胞中表达并具有生物活性。可望用于帕金森病的基因治疗。     

传染性支气管炎病毒核衣壳蛋白基因克隆及在E.coli中的表达

核衣壳蛋白基因 (N基因 )是传染性支气管炎病毒的重要结构基因 .根据已报道的序列设计引物 ,利用RT PCR技术从病毒RNA中扩增和克隆到了N基因的cDNA ,并测定了核苷酸序列 .克隆的N基因片段ORF全长 12 30bp ,编码 4 0 9个氨基酸 .将该片段序列与其他IBV病毒株比较 ,核苷酸的同一性为 87 0 %～ 98 6 %,氨基酸的同一性为 91 0 %～ 98 1%.将该cDNA亚克隆到pBV2 2 0表达载体 ,转化大肠杆菌DH5α菌株 ,Western印迹检测 ,获得了分子量约 4 5kD表达蛋白     

人同源盒基因NKX3.1对前列腺癌细胞的诱导凋亡作用

构建人同源盒基因NKX3.1 cDNA真核表达载体,研究其在前列腺癌细胞PC-3、LNCaP 中的表达及对细胞的促凋亡作用.以人前列腺癌细胞LNCaP细胞中的总RNA为模板,RT-PCR扩增NKX3.1基因全长编码片段,将NKX3.1 cDNA重组到真核表达载体pcDNA3.1（+）中; 将pcDNA3.1-NKX3.1表达载体瞬时转染前列腺癌细胞PC-3和LNCaP 细胞,用RT-PCR和Western印迹检测NKX3.1 cDNA在转录水平和蛋白水平的表达;绘制细胞生长曲线,观察NKX3.1对前列腺癌细胞增殖的抑制作用;用DNA/ladder和流式细胞术检测NKX3.1对前列腺癌细胞凋亡的影响,进一步用RT PCR检测凋亡相关基因caspase3、caspase8、caspase9、Apaf1、survivin和Bcl2表达的变化.人同源盒基因NKX3.1 cDNA真核表达载体pcDNA3.1-NKX3.1经酶切及测序鉴定正确. pcDNA3.1-NKX3.1转染PC-3和LNCaP细胞后,经RT-PCR和Western印迹证明能有效表达NKX3.1.生长曲线显示,前列腺癌细胞转染NKX3.1 cDNA后细胞增殖受到抑制;前列腺癌细胞转染NKX3.1 cDNA 48 h后,DNA电泳呈现具有凋亡特征的DNA ladder;流式细胞术检测出现明显凋亡峰;RT-PCR检测凋亡相关基因.结果显示,caspase3、caspase8、caspase9基因表达明显增加,Bcl2基因表达明显减少.本研究成功构建了真核表达载体pcDNA3.1 NKX3.1, 转染PC3和LNCaP细胞后能有效表达,并对细胞具有诱导凋亡作用     

SSH技术筛选β干扰素真核表达载体转染细胞的下调基因

筛选β-干扰素质粒转染下调相关基因.以β-干扰素表达质粒pcDNA3.1(-)-IFN β转染HepG2细胞,同时以空载体pcDNA3.1(-)为对照;制备转染后的细胞裂解液,从中提取mRNA并合成cDNA,经RsaI酶切后将来自pcDNA3.1(-)转染的cDNA分成两组,分别与两种不同的接头adaptor1和adaptor2衔接,再与来自pcDNA3.1(-)-IFNβ转染的cDNA进行两次消减杂交及两次抑制性PCR,将产物与T/A载体连接,构建cDNA消减文库,并转染大肠杆菌进行文库扩增,随机挑选克隆PCR后进行测序及同源性分析.成功构建人β-干扰素质粒转染下调相关基因差异表达的cDNA.所获得的50个克隆中,随机挑选37个克隆均含有插入片段,将这些克隆进行序列测定,并通过生物信息学分析获得其全长基因序列,结果共获得22种编码基因,其中3种为未知功能的基因.筛选到的cDNA序列,包括与细胞生长调节、物质代谢和细胞凋亡密切相关的一些蛋白编码基因.     

TRAIL在细胞中的表达及其诱导凋亡的活性分析

以PCR方法克隆了Trail cDNA全长,构建了其真核表达载体,通过脂质转染HeLa细胞,48小时后利用流式细胞仪分析Trail诱导细胞凋亡的比率,发现发生凋亡的细胞为总细胞数的19％。证实了Trail真核4表达系统的产物的生物学活性高,为从真核表达的途径获得Trail基因工程产品奠定了基础。     

血小板生成素改构体基因的克隆和序列分析

采用PCR技术,根据文献报道的鼠TPO成熟肽基因序列,设计并合成两对引物,以鼠TPO cDNA为模板,扩增获得mTPO N端153个氨基酸的478bp cDNA片段及鼠TPO全长1032bp cDNA片段,mTPO153片段与合成的碱性成纤维生长因子序列中Lys119-Lys135as的51bp肝素结合位点DNA片段连接,克隆到M13mp18及M13mp19载体中进行双向测序;同时将扩增的鼠TPO全长cDNA片段克隆到M13mp18及M13mp19载体中进行双向测序。证明获得鼠血小板生成素与肝素结合位点基因及鼠TPO全长基因,继之以pMAL-C2X为表达载体构建表达质粒,并经PCR及酶切鉴定。     

核苷酸切除修复基因XPA反义RNA表达载体的构建及其抑瘤功能

采用RT PCR方法扩增出 4 2 6bp着色性干皮病A(xerodermapigmentosumgroupA ,XPA)cDNA片段 (2～ 4 2 7bp) ,反向插入pcDNA3 1质粒构建XPA反义RNA表达载体 .经测序证实 ,该片段序列与XPAmRNA对应片段完全互补 .通过脂质体Lipofectamine 2 0 0 0将重组质粒转染肺癌A5 4 9细胞 ,RT PCR检测表明转染XPA反义RNA重组质粒能够抑制肺癌细胞XPAmRNA表达 ;MTT实验表明转染XPA反义RNA的肺癌细胞对顺铂敏感性增强 .本研究为深入探讨NER途径基因功能及临床克服肿瘤耐药提出了一个新的思路     

人钠/碘同向转运体基因cDNA的克隆与序列测定

为研究人钠／碘同向转运体(hNIS)的生物学性能和用于肿瘤放射性碘治疗的可能性,运用反转录聚合酶链反应(RT—PCR)从人甲状腺组织总RNA中扩增出hNIS基因cDNA序列,将其克隆至pUCm-T载体中。序列分析证实克隆片段与献报道的hNIS基因cDNA序列完全一致,说明已成功克隆到hNIS基因cDNA。     

表达超抗原SEA基因的溶瘤腺病毒载体的构建与鉴定

目的:构建表达超抗原SEA基因的溶瘤腺病毒载体并鉴定.方法:采用PCR技术,从产SEA的葡萄球菌标准菌株ATCC13565基因组DNA中获得SEA全长基因序列,酶切后克隆入pCA13质粒,构建重组病毒质粒pCA13-SEA.将鉴定正确的pCA13-SEA与含有腺病毒右臂的质粒pBHGE3通过Lipofectamine2000共转染HEK293细胞,经同源重组产生重组腺病毒Ad-SEA.Ad-SEA在293细胞中大量扩增并通过氯化铯密度梯度离心法纯化、测定其滴度.结果:经PCR扩增、酶切鉴定、序列测定证实,SEA基因成功克隆到溶瘤腺病毒载体中,可实现SEA基因的表达.结论:成功构建了表达超抗原SEA基因的溶瘤腺病毒载体,为进一步研究该病毒对膀胱肿瘤靶向治疗的作用奠定了基础.     

Fas is expressed early in human thymocyte development but does not transmit an apoptotic signal.

We investigated the expression and function of Fas on human thymocytes prepared from fetal and pediatric tissue specimens and from SCID-hu Thy/Liv grafts. Unlike mouse thymocytes, human thymocytes exhibited a pattern of Fas expression skewed to immature cells, in that the highest expression was seen on double negative thymocytes and on intrathymic T progenitor cells. Fas expression was intermediate on double positive human thymocytes, and low or negative on mature single positive CD4 and CD8 medullary thymocytes. In spite of this relatively abundant surface expression, cross-linking of Fas with agonist mAb was incapable of triggering an apoptotic signal in human thymocytes. Apoptotic signaling was not enhanced by treatment with cycloheximide, nor by restoring a cosignaling milieu by addition of thymic stromal cells. Mouse thymocytes were induced to apoptosis by cross-linked recombinant soluble human Fas ligand both in vitro and in vivo, though human thymocytes were also resistant to this mode of receptor ligation. Membrane-bound Fas ligand also induced apoptotic death in murine thymocytes but not in human thymocytes. Human thymocytes were as sensitive as Jurkat cells, however, to apoptosis induced by TNF-alpha, suggesting that these cells have a signaling defect before activation of the earliest caspases. These data demonstrate a durable and specific resistance of human thymocytes to apoptosis induced through Fas receptor engagement, and reveal significant species-specific differences in the biology of thymocyte-programmed cell death.     

Soluble Fas (FasB) regulates luteal cell apoptosis during luteolysis in murine ovaries

During luteolysis, luteal cell apoptosis is induced by the Fas ligand (FasL)/Fas system. In murine luteal bodies, we demonstrated the expression of mRNA of soluble form of Fas (FasB), which binds to FasL and prevents apoptosis induction. By in situ hybridization, strong expression of FasB mRNA was observed in normal luteal bodies, in which no apoptotic cells were detected, but negative/trace expression in regressing luteal bodies, in which many apoptotic cells were observed. Immunohistochemical staining revealed that Fas and TNF-alpha were localized in both normal and regressing luteal bodies, but IFN-gamma was localized only in regressing luteal bodies. Apoptosis was induced in primary cultured luteal cells, when they were pretreated with TNF-alpha and IFN-gamma and then incubated with TNF-alpha, IFN-gamma, and mouse recombinant FasL (rFasL). However, no apoptosis was detected in the cells, when they were treated with rFasL alone, TNF-alpha alone, IFN-gamma alone, TNF-alpha and rFasL, IFN-gamma and rFasL, or TNF-alpha and IFN-gamma. Fas mRNA expression in cultured luteal cells was up-regulated by the treatment of TNF-alpha, IFN-gamma, or TNF-alpha and IFN-gamma. The expression of FasB mRNA was down-regulated, when the cells were treated with TNF-alpha and IFN-gamma, but its expression was not changed by the treatment of TNF-alpha alone or IFN-gamma alone. We conclude that FasB inhibits the apoptosis induction in luteal cells of normal luteal bodies, and that decreased FasB production induced by TNF-alpha and IFN-gamma made possible the apoptosis induction in the luteal cells of regressing luteal bodies.     

SCG10基因重组质粒的构建及蛋白表达和定位

目的构建SCG10真核表达载体并证实融合蛋白在细胞内表达及定位。方法以人胎脑cDNA文库为模板,PCR扩增SCG10全长编码基因,亚克隆至pEGFP-C1表达载体中。将构建的重组质粒测序并转染到人胚肾HEK293中,提取细胞蛋白进行Western blot检测。利用共聚焦激光扫描显微镜观察pEGFP-SCG10在HEK293细胞内定位。结果 SCG10全长基因序列克隆到了真核表达载体pEGFP-C1中,酶切鉴定片段大小540bp。Western blot检测到了融合蛋白表达,分子量约为48kD。pEGFP-SCG10在细胞内定位以细胞浆为主,在细胞核少量表达。结论成功构建了SCG10全长基因真核表达载体,pEGFP-SCG10蛋白主要定位于HEK293细胞浆内。     

Higher susceptibility to Fas ligand induced apoptosis and altered modulation of cell death by tumor necrosis factor-alpha in periarticular tenocytes from patients with knee joint osteoarthritis

The aim of the present study was to investigate the expression of Fas in periarticular tenocytes of patients with osteoarthritis (OA) and to study their susceptibility to Fas ligand-mediated apoptosis. Tendon samples were obtained from the quadriceps femoris muscle of patients with knee OA and used for histological evaluation, for immunohistochemical detection of Fas, and to establish tenocyte cultures. The expression of Fas mRNA was determined by quantitative PCR. Levels of soluble Fas and soluble tumour necrosis factor (TNF) receptor I were measured using ELISA. Apoptosis was induced with recombinant human Fas ligand and measured by a histone fragmentation assay and flow cytometry. The effects of TNF-alpha were studied by stimulation with TNF-alpha alone or 24 hours before the induction of apoptosis. Tendon samples from non-OA patients were used as controls. Histological evaluation revealed degenerative changes in the tendons of all OA patients but not in the controls. Fas was detected by immunohistochemistry in all specimens, but quantitative PCR revealed significantly higher levels of Fas mRNA in OA tenocytes. In contrast, lower levels of soluble Fas were found in OA tenocytes by ELISA. OA tenocytes were significantly more susceptible to Fas ligand induced apoptosis than were control cells. TNF-alpha reduced the Fas ligand induced apoptosis in OA tenocytes but had no effects on control tenocytes. These data suggest that knee OA is associated with higher susceptibility of periarticular tenocytes to Fas ligand induced apoptosis because of higher expression of Fas but lower levels of apoptosis-inhibiting soluble Fas. These changes may contribute to decreased cellularity in degenerative tendons and promote their rupturing. The antiapoptotic effects of TNF-alpha in OA tenocytes most likely reflect regenerative attempts and must be taken into account when anti-TNF strategies are considered for OA.     

鼠重组磷脂酶D2腺病毒的构建及功能的初步研究

将磷脂酰胆碱专一性磷脂酶D2基因及其功能缺陷点突变基因 (K75 8R)从真核表达载体pCGN中克隆至带有绿色荧光标记蛋白的穿梭质粒pAdTrack CMV中 ;再与腺病毒骨架载体一起在大肠杆菌BJ5183中进行同源重组 ,成功构建磷脂酶D2重组腺病毒。该病毒颗粒感染人胚肾 2 93细胞 ,高效表达磷脂酶D2及其功能缺陷蛋白。这种表达对M3乙酰胆碱受体介导的细胞内磷脂酶D激活无影响。但磷脂酶D2功能缺陷蛋白对蛋白激酶C介导的胞内磷脂酶D激活有显著抑制作用 ;相反 ,磷脂酶D2蛋白有显著增强作用。结果表明     

Interpreting interest in interferon-α

The aim of the present study was to investigate the expression of Fas in periarticular tenocytes of patients with osteoarthritis (OA) and to study their susceptibility to Fas ligand-mediated apoptosis. Tendon samples were obtained from the quadriceps femoris muscle of patients with knee OA and used for histological evaluation, for immunohistochemical detection of Fas, and to establish tenocyte cultures. The expression of Fas mRNA was determined by quantitative PCR. Levels of soluble Fas and soluble tumour necrosis factor (TNF) receptor I were measured using ELISA. Apoptosis was induced with recombinant human Fas ligand and measured by a histone fragmentation assay and flow cytometry. The effects of TNF-α were studied by stimulation with TNF-α alone or 24 hours before the induction of apoptosis. Tendon samples from non-OA patients were used as controls. Histological evaluation revealed degenerative changes in the tendons of all OA patients but not in the controls. Fas was detected by immunohistochemistry in all specimens, but quantitative PCR revealed significantly higher levels of Fas mRNA in OA tenocytes. In contrast, lower levels of soluble Fas were found in OA tenocytes by ELISA. OA tenocytes were significantly more susceptible to Fas ligand induced apoptosis than were control cells. TNF-α reduced the Fas ligand induced apoptosis in OA tenocytes but had no effects on control tenocytes. These data suggest that knee OA is associated with higher susceptibility of periarticular tenocytes to Fas ligand induced apoptosis because of higher expression of Fas but lower levels of apoptosis-inhibiting soluble Fas. These changes may contribute to decreased cellularity in degenerative tendons and promote their rupturing. The antiapoptotic effects of TNF-α in OA tenocytes most likely reflect regenerative attempts and must be taken into account when anti-TNF strategies are considered for OA.     

肿瘤坏死因子相关的凋亡诱导配体(TRAIL)cDNA的克隆、表达和活性测定

肿瘤坏死因子相关的凋亡诱导配体 (TRAIL)能选择性诱导肿瘤细胞凋亡 .为利用基因工程技术获得重组TRAIL蛋白可溶性片段 (sTRAIL) ,设计 1对引物 .利用PCR技术特异性扩增出sTRAIL的cDNA ,克隆于质粒pGEM 3Zf( )的EcoRⅠ和PstⅠ位点 .经测序证明序列正确后克隆于表达质粒pBV2 2 0的EcoRⅠ和PstⅠ位点 ,转化大肠杆菌DH5α .转化菌株经温度诱导 ,SDS PAGE检测和Western印迹鉴定 ,获得重组sTRAIL的高水平非融合表达菌株 .表达量占菌体总蛋白的 2 0 % .对其表达产物进行了初步纯化 ,SDS PAGE结果显示纯度可达 90 %以上 .用L92 9细胞测定其生物学活性表明 ,重组蛋白在体外能明显诱导肿瘤细胞凋亡     

犬细小病毒NS1 非结构蛋白可诱导细胞凋亡

【目的】研究犬细小病毒(Canine parvovirus,CPV)非结构蛋白NS1在CPV引起宿主细胞凋亡中的作用,初步探讨CPV引起细胞凋亡的机制。【方法】首先采用PCR方法从犬细小病毒基因组中扩增NS1编码基因,然后利用pcDNA3.1A质粒构建NS1真核表达载体pcDNA-NS1,并通过HEK293FT细胞瞬时表达NS1重组蛋白,用Western-blot检测以确定重组NS1蛋白能否在真核细胞中表达。然后用CPV感染和用pcDNA-NS1表达载体转染F81宿主细胞,通过AnnexinV/PI双染法检测磷脂酰丝氨酸外翻和通过化学发光法检测caspase-3/7活性,分析感染CPV或转染NS1基因对F81宿主细胞凋亡的影响。【结果】结果表明,本实验扩增的NS1基因序列与GenBank的序列一致,构建的表达载体结构正确,并能够介导NS1基因在真核细胞中表达。感染CPV和转染NS1基因均能诱导F81细胞膜磷脂酰丝氨酸外翻和明显提高细胞内caspase-3/7的活性,表明CPV和NS1蛋白均能引起细胞的凋亡。【结论】CPV诱导宿主细胞凋亡与其编码的NS1非结构蛋白有关。     

携带siSPK1重组腺病毒的构建及其对N2a细胞凋亡的影响

应用AdMax腺病毒载体系统构建携带siSPK1基因的重组腺病毒,进一步研究SPK1基因对N2a细胞凋亡的影响。设计可形成小发夹结构的SPK1-siRNA模板cDNA序列,克隆至质粒pDC316-siRNA,构建SPK1-siRNA穿梭质粒pDC316-SPK1,经鉴定正确后,将pDC316-SPK1与辅助包装质粒（pBHG loxΔE1,3 Cre）共转染至HEK293细胞,包装纯化并扩增重组腺病毒颗粒,终点稀释法测定病毒滴度;病毒感染N2a细胞,Western blot法检测SPK1蛋白的表达;Hoechst33258染色检测SPK1基因对N2a细胞凋亡的影响。酶切后PCR分析、测序鉴定表明,pDC316-SPK1构建成功,病毒纯化后滴度为2.50E＋10 PFU/mL;重组病毒可在蛋白水平抑制SPK1的表达;SPK1基因抑制后,N2a细胞凋亡增加（P〈0.001）。上述结果表明,含有SPK1-siRNA的重组腺病毒构建成功,且具有抑制SPK1蛋白表达的功能,该基因沉默后,N2a细胞凋亡增加。