携带绿色荧光蛋白基因的APP695真核细胞表达载体的构建及鉴定

目的 构建大鼠淀粉样前体蛋白(APP)695基因真核细胞荧光表达载体,进行细胞转染、表达,为阿尔茨海默病(AD)治疗药物的研究提供一种有效的细胞模型.方法 设计并合成APP695基因的引物,以携带APP695基因的真核细胞表达载体pCB6质粒为模板,PCR扩增得到APP695基因全序列:将APP695基因连接到携带绿色荧光蛋白基因的载体pIRES2-EGFP上;应用酶切分析、PCR检测及DNA测序分析等鉴定所构建的真核细胞表达载体.结果 以重组载体为模板扩增得到的片段大小与已知APP695基因大小相同,酶切也得到目的 基因片段,测序结果显示与已知APP695基因序列相同.结论 成功构建了携带绿色荧光蛋白基因的APP695基因真核细胞表达载体,为AD治疗药物的研究提供了一种有效的分子工具.     

BDNF基因重组逆转录病毒表达载体pLEGFP-BDNF的构建与鉴定

目的构建脑源性神经营养因子(BDNF)基因重组逆转录病毒表达载体。方法根据 BDNF基因已知序列,设计合成一对引物并导入HindⅢ和BamH Ⅰ酶切位点;从大鼠海马组织提取总 RNA,逆转录聚合酶链反应(RT-PCR)获得编码BDNF的基因片段,与克隆载体pMD 18-T Simple连接构建pMDT-BDNF质粒;经HindⅢ、BamHⅠ双酶切,获得BDNF基因片断再克隆至逆转录病毒载体 pLEGFP-N1中构建重组质粒pLEGFP-BDNF。结果限制性内切酶酶切分析和PCR法鉴定表明为正确重组子,测序结果证实与已知序列吻合。结论构建的重组逆转录病毒表达载体 pLEGFP-BDNF含有序列正确的大鼠BDNF基因,可以作为今后治疗老年性痴呆动物模型转基因实验的基因来源。     

携带DREAM基因小分子干扰RNA重组质粒的构建☆

背景：DREAM是一种多功能蛋白,在细胞中不同位置与不同靶蛋白结合,体外细胞培养和动物实验均证明DREAM参与了许多疾病的发病机制。 目的：构建携带DREAM基因的小分子干扰RNA重组质粒。 方法：设计并合成shRNA对应的两条互补的寡核苷酸链,pDC316-EGFP-U6质粒经BamHⅠ和HindⅢ双酶切与退火后的寡核苷酸连接,转化感受态E.coli DH5α,获得阳性克隆进行PCR和测序鉴定。 结果与结论：经PCR、酶切及测序证实,重组质粒pDC316-EGFP-DREAM-shRNA-U6片段大小为473 bp,其中插入的片断序列和位点与预期完全一致,说明pDC316-EGFP-DREAM-shRNA-U6重组质粒构建成功。     

小干扰RNA对人淀粉样前体蛋白基因的沉默作用

目的观察小干扰RNA(siRNA)对人淀粉样前体蛋白(APP)基因的沉默作用.方法将设计好的一对寡核苷酸在细胞内源性地转录成小发夹RNA(shRNA),同时构建了携带2个APP亚型的增强型绿色荧光蛋白(EGFP)的GFP-APP重组质粒;利用EGFP作为报告基因,在COS-7细胞内通过共转染siRNA 表达质粒和GFP-APP重组质粒来观察沉默效应.结果针对APP的siRNA可有效地下调APP基因.结论针对APP的siRNA将不仅在研究APP基因功能和深入研究阿尔茨海默病(AD)的病理分子机制上,而且在运用siRNA这种新型的反义核酸药物治疗AD方面扮演重要角色.     

靶向人血管紧张素原小干扰RNA表达质粒的构建和鉴定

背景：RNA干扰技术通过将具有一定结构特点、长19~25 bp的双链小干扰RNA导入哺乳动物细胞,特异性降解与其序列具有同源性的mRNA分子,导致目的基因表达抑制。 目的：拟构建针对人血管紧张素原mRNA的小干扰RNA表达载体,从而抑制肾素基因在脂肪细胞的表达。 方法：从NCBI中查找人血管紧张素原基因全长mRNA序列(NM000029),利用GeneScript公司提供的在线小干扰RNA模板序列设计软件,自行设计靶向血管紧张素原的两条shRNA的DNA模板单链,合成靶向血管紧张素原基因转录可形成茎环结构的寡聚核苷酸,退火后与酶切后的psiRNAT-U6.1/Neo质粒连接,在TOP10菌株中扩增,并测序鉴定。 结果与结论：将含有血管紧张素原-mRNA目标序列19 bp的双链DNA插入片段,连接到pRNAT-U6.1/Neo质粒形成重组质粒。EcoRⅠ和Hind Ⅲ双酶切后,空载体得到351 bp小片段,而人重组质粒得到397 bp小片段,与预期相符。EcoRⅠ和Kpn Ⅰ双酶切后,空载体得到1条345 bp小片段,而人重组载体没有得到小片段条带,与预期相符。测序结果表明psiRNAT-U6.1/Neo质粒已经插入人脂肪细胞的干扰合成片段,无碱基突变,成功构建了靶向血管紧张素原-小干扰RNA表达载体。     

分子伴侣辅因子热休克蛋白70羧基末端相互作用蛋白真核表达载体pDsRed2-N1(+)/CHIP构建及在COS-7细胞中的表达*******

背景：热休克蛋白70羧基末端相互作用蛋白与许多神经退行性疾病的相关蛋白质存在相互作用,并促进这些蛋白质的降解,因此对热休克蛋白70羧基末端相互作用蛋白功能的研究具有非常重要的意义。 目的：构建分子伴侣辅因子热休克蛋白70羧基末端相互作用蛋白真核表达载体pDsRed2-N1(+)/CHIP,检测其转染COS-7细胞后的表达。 设计、时间及地点：单一样本观察,于2007-05/2008-02在广东省人民医院医学研究中心完成。 材料：大肠杆菌E coli DH5α,质粒pDsRed2-N1(+)为广东省人民医院医学研究中心肖定璋主任馈赠;人cDNA文库为中南大学湘雅医院神经内科馈赠。 方法：用聚合酶链反应方法从人cDNA文库DNA中扩增热休克蛋白70羧基末端相互作用蛋白全长cDNA,该基因片段两端设计了Hind Ⅲ 和BamH Ⅰ限制性酶切位点。将所得片段连接到T载体上测序证实。利用重组DNA技术将热休克蛋白70羧基末端相互作用蛋白的cDNA构建到真核表达载体pDsRed2-N1(+)上,酶切鉴定。通过脂质体介导的转染技术将所构建的载体导入COS-7细胞中,体外培养,于转染48 h后利用反转录-聚合酶链反应和Western Blotting方法检测目的基因的表达情况。 主要观察指标：①热休克蛋白70羧基末端相互作用蛋白 cDNA扩增产物检测。②pDsRed2-N1(+)/CHIP重组体酶切鉴定。③反转录-聚合酶链反应。④免疫荧光及Western-blotting。 结果：经琼脂糖凝胶电泳及测序证实,聚合酶链反应获得的片段与GenBank中登记的热休克蛋白70羧基末端相互作用蛋白序列完全相同;pDsRed2-N1/CHIP酶切片段的长度与理论大小相符;转染48 h后的COS-7细胞在mRNA和蛋白质水平均可检测到热休克蛋白70羧基末端相互作用蛋白的表达。 结论：热休克蛋白70羧基末端相互作用蛋白真核表达载体构建成功,在COS-7细胞中可获得表达。     

变异链球菌表面蛋白SpaP P区真核表达质粒的构建及表达

背景：变异链球菌是龋病的主要致龋菌,针对介导变异链球菌非蔗糖依赖性黏附的重要毒力因子SpaP的基因疫苗在理论上能对抗变异链球菌黏附于牙面和进一步破坏牙体硬组织。 目的：构建变异链球菌表面蛋白P 区(SpaP/P)真核表达质粒pVAX1-spap/P,并观察其在哺乳动物细胞COS-7中的表达。 方法：通过基因重组技术,构建真核表达质粒pVAX1-spap/P,并经酶切分析、测序分析鉴定正确后,采用脂质体转染法,将其转染至COS-7细胞中,然后经免疫组织化学SABC法检测其在细胞中的表达。 结果与结论：真核表达质粒pVAX1-spap/P经 EcoR Ⅰ和 Xba Ⅰ双酶切分析,证实携带1.2 kb的目的基因spap/P片段,经测序分析,目的基因正向插入到预先设计的载体位点处。pVAX1-spap/P转染的细胞胞质呈褐色,pVAX1空载体质粒转染的细胞胞质中无着色。证实实验成功构建真核表达质粒pVAX1-spap/P,所携带的基因序列正确,能够在真核细胞COS-7中正确表达目的蛋白。     

构建人HCN4基因重组腺病毒载体及其对大鼠骨髓间充质干细胞的感染效率

背景：超极化激活及环化核苷酸门控阳离子通道(hyperpolarization-activated cyclic nucleotide-gated cation channel, HCN)基因由于具有不增加诱发心律失常的风险、能够接受自主神经系统调节等优势,成为目前最受关注的生物起搏备选基因。 目的：构建携带人HCN4基因的重组腺病毒载体,并测定其对大鼠骨髓间充质干细胞的感染效率。 设计、时间及地点：细胞-基因学体外实验,于2008-02/09在中山大学附属第二医院林百欣实验中心完成。 材料：SD大鼠10只,由中山大学实验动物中心提供。携带目的基因人HCN4 cDNA的质粒pcDNA3.1-HCN4、人胚肾293细胞、大肠杆菌DH5α由中山大学附属第二医院林百欣实验中心保存。腺病毒穿梭质粒pShuttle-CMV、骨架质粒pAdxsi购自北京诺赛基因组研究中心有限公司。 方法：质粒pcDNA3.1-HCN4用Hind Ⅲ+Xba Ⅰ双酶切后回收HCN4片段,亚克隆至pShuttle-CMV中,得到重组穿梭质粒;I-Ceu Ⅰ+I-Sce Ⅰ双酶切处理pShuttle-CMV-HCN4,回收CMV-HCN4片段,亚克隆至腺病毒骨架载体pAdxsi,得到重组腺病毒质粒;重组腺病毒质粒酶切线性化后,应用脂质体法转染293细胞进行包装扩增,得到重组腺病毒AdHCN4;应用AdHCN4转染大鼠骨髓间充质干细胞。 主要观察指标：重组腺病毒质粒载体的鉴定,重组腺病毒的鉴定及滴度测定,重组腺病毒的感染效率。 结果：构建的重组穿梭质粒pShuttle-CMV-HCN4用Hind Ⅲ+Xho Ⅰ双酶切,得到大小为3 600 bp(HCN4)和5 100 bp (pShuttle-CMV)两个片段,DNA测序结果证实人HCN4基因的全长序列已正确插入到pShuttle-CMV穿梭质粒中;重组腺病毒质粒pAdxsi-CMV-HCN4用XhoⅠ酶切得到7个片段,而作为对照的空腺病毒质粒只得到6个片段;重组腺病毒质粒在293细胞中包装后产生的重组腺病毒对293细胞有致病作用;重组腺病毒AdHCN4 PCR鉴定可见657 bp的阳性扩增条带;经多次重复感染后,病毒滴度检测达2.5×1011PFU/mL。成功转染AdHCN4的大鼠骨髓间充质干细胞可表达绿色荧光蛋白,当病毒感染复数值为800,转染效率最高,达90%。 结论：实验成功构建携带人HCN4基因的重组腺病毒载体,并可在体外有效转染大鼠骨髓间充质干细胞。     

增强型绿色荧光蛋白-神经标识真核表达载体构建及在细胞内的表达

目的 构建可转染神经胶质细胞和神经元的增强型绿色荧光蛋白-神经标识(EGFP-ID)真核表达载体,为神经突起损伤活体研究提供技术方法. 方法 采用PCR方法分别从质粒pEGFP-N1载体和大鼠脑组织基因组DNA中扩增EGFP和ID序列.通过T4 DNA连接酶将纯化后的PCR产物EGFP与经过BamH Ⅰ和EcoR Ⅰ双酶切的pcDNA4.1-hisB载体连接.将经克隆测序确定的pcDNA4.1-EGFP经由NotⅠ和Xba Ⅰ双酶切并与纯化的PCR产物ID连接,再次克隆测序确定为pcDNA4.1-EGFP-ID.将pcDNA4.1-EGFP与pcDNA4.1-EGFP-ID在转染试剂Fugene6 介导下转染人神经胶质瘤U87细胞和小鼠原代培养神经元,通过倒置荧光显微镜观察EGFP在2种细胞内的分布.此外,用50 μmol/L核苷类似物司他夫定处理神经元8d,第8天末观察EGFP-ID 示踪细胞突起发育情况,并与免疫荧光检测结果作比较. 结果 成功扩增得到EGFP和ID基因片段,重组得到EGFP-ID真核表达载体,该载体携带的EGFP基因在U87细胞和神经元内表达并布满细胞突起,示踪神经元突起形态变化的结果与免疫荧光观察结果一致. 结论 pcDNA4.1-EGFP-ID能够介导EGFP基因在神经元和胶质细胞突起内表达,从而直观再现神经突起形态特征.     

重组质粒pEGFP-mDlX5的构建及其在SVZa神经干细胞中的表达研究

目的构建真核表达重组质粒pEGFP-mDlx5,并了解它在室管膜前下区(SVZa)神经干细胞(NSCs)中的mRNA及融合蛋白表达情况。方法运用DNA重组技术自原核表达载体上将小鼠来源的mDlx5基因克隆到增强型绿色荧光蛋白(EGFP)载体上,并用双酶切、测序进行鉴定;将重组质粒用电穿孔的方法转染SVZa NSCs,荧光显微镜下动态观察荧光变化情况;培养24h后提取转染细胞的总RNA及总蛋白,通过逆转录-多聚酶链反应(RT-PCR)了解其mRNA表达情况,用Western blot 检测其蛋白表达情况。结果重组质粒通过双酶切产生了0．78 kb目的插入片段及4．68 kb载体片段;测序后证实0．78 kb片段碱基序列与mDlx5基因完全同源;重组质粒转染SVZa NSCs 8 h后在荧光显微镜下观察到绿色荧光,12 h后逐渐增多,24-48 h达高峰,且稳定表达较长时间;24 h后通过 RT-PCR检测到mRNA表达,Western blot检测到58 kD目的蛋白表达。结论新构建的真核表达重组质粒pEGFP-mDlx5通过鉴定,结构正确:转染到SVZa NSCs后能在其中表达、发挥功能,为后续研究奠定了基础。     

Protein microarray analysis identifies human cellular prion protein interactors

Aims: To obtain an insight into the function of cellular prion protein (PrPC), we studied PrPC‐interacting proteins (PrPIPs) by analysing a protein microarray. Methods: We identified 47 novel PrPIPs by probing an array of 5000 human proteins with recombinant human PrPC spanning amino acid residues 23–231 named PR209. Results: The great majority of 47 PrPIPs were annotated as proteins involved in the recognition of nucleic acids. Coimmunoprecipitation and cell imaging in a transient expression system validated the interaction of PR209 with neuronal PrPIPs, such as FAM64A, HOXA1, PLK3 and MPG. However, the interaction did not generate proteinase K‐resistant proteins. KeyMolnet, a bioinformatics tool for analysing molecular interaction on the curated knowledge database, revealed that the complex molecular network of PrPC and PrPIPs has a significant relationship with AKT, JNK and MAPK signalling pathways. Conclusions: Protein microarray is a useful tool for systematic screening and comprehensive profiling of the human PrPC interactome. Because the network of PrPC and interactors involves signalling pathways essential for regulation of cell survival, differentiation, proliferation and apoptosis, these observations suggest a logical hypothesis that dysregulation of the PrPC interactome might induce extensive neurodegeneration in prion diseases.     

Protein aggregate myopathies

Protein aggregate myopathies (PAMs) based on the morphologic phenomenon of aggregation of proteins within muscle fibers may occur in children (selenoproteinopathies, actinopathies, and myosinopathies) or adults (certain myofibrillar myopathies and myosinopathies). They may be mutation related, which includes virtually all childhood forms but certain other forms as well, or sporadic, which are largely seen in adults. Their classification as myofibrillar or desmin-related myopathies, actinopathies, or myosinopathies is based on the identification of respective mutant proteins, most of them components of the sarcomeres. Recognition of PAM requires muscle biopsy and an extensive immunohistochemical and electron microscopic workup of the biopsied muscle tissue after which molecular analysis of morphologically ascertained proteins should ensue to permit recognition of individual entities and genetic counseling of patients and families. Because pathogenetic principles in PAMs are still incompletely known, causative therapy, at this time, is not available.     

P53蛋白在脑胶质细胞瘤中的表达

用SP免疫组化方法检测79例脑胶质细胞瘤中P53蛋白的表达,总阳性率为21.52%.其中星形细胞瘤及室管膜瘤阳性率分别为26%及25%,且Ⅲ、Ⅳ级肿瘤阳性率及表达量均显著高于Ⅰ、Ⅱ级肿瘤.表明P53蛋白的表达与这两型肿瘤的恶性程度密切相关.但临床上恶性程度很高的髓母细胞瘤反而未见表达.     

急性脑卒中患者血清神经元特异性烯醇化酶、S-100B蛋白、髓鞘碱性蛋白水平的变化

目的探讨急性脑卒中患者血清神经元特异性烯醇化酶(NSE)、S-100B蛋白、髓鞘碱性蛋白(MBP)水平变化及其临床意义。方法回顾性对照分析发病在48 h内的45例急性脑卒中患者(其中脑梗死组19例,脑出血组15例,短暂性脑缺血发作组11例)血清NSE、S-100B蛋白、MBP水平变化及其与脑梗死、脑出血患者神经功能缺损程度的相关性。结果脑梗死组和脑出血组患者血清NSE、S-100B蛋白、MBP水平均较对照组有不同程度增高(P<0.05),而短暂性脑缺血发作组与正常对照组比较均无明显变化。脑梗死组和脑出血组患者中神经功能缺损较重的中重型亚组患者血清NSE、S-100B蛋白、MBP水平较轻型亚组水平高(P<0.05)。结论血清NSE、S-100B蛋白、MBP水平可作为急性脑卒中患者病情判断、预后评估的指标之一,对早期脑梗死与短暂性脑缺血发作也有鉴别诊断价值,尤其适用于无法进行影像学检查的脑卒中患者。     

Protein synthesis in the mammalian retina following the intravenous administration of LSD

Polysomes in the retina of the rabbit eye are disaggregated to monosomes following the intravenous injection of LSD. The effect is rapid in onset with maximal disaggregation by 1 h ande transient in duration with recovery to normal polysome levels by 4 h. Analysis of the mechanism of LSD-induced polysome disaggregation indicates that it is not the result of RNAase degradation of polysomal mRNS. In vivo labeling studies demonstrate that LSD induces an increased synthesis of retinal proteins of molecular weight 74,000 (74K) and 95,000 (95K) at a time when overall protein synthesis in the retina is reduced. Translation of purified retinal polysomes in a cell-free protein synthesis system and resolution of labeled proteins by two-dimensional gel electrophoresis and fluorography reveals that LSD selectively increases the relative abundance of polysomal mRNA coding for the 74K and 95K retinal proteins.     

Protein C activity in renal disease

Protein C activity was determined in 19 healthy controls and in 52 patients with renal diseases, clinically divided into three groups I) Nephrotic syndrome, II) Renal insufficiency, III) Terminal uremia, requiring maintenance dialysis. In the nephrotic syndrome protein C levels were found to be normal, but in renal insufficiency and terminal uremia the protein C activity was significantly decreased. A correlation between decreasing protein C and progressive renal failure is suggested. The reduced protein C activity may play an important role in the thrombotic tendency seen in renal diseases and uremia.     

蛋白质转导及在神经科学研究中的应用

蛋白质转导或蛋白质治疗是通过表达载体法或化学交联法将具有治疗作用的外源性蛋白质与称为蛋白质转导域的氨基酸片段相连，以非受体和非温度依赖的方式穿越细胞膜进入胞内达到治疗疾病的目的，这种内在化的异质蛋白质不仅依旧保持了原有的生物学活性和功能。而且能在保持血脑屏障完整的情况下进入脑内。目前，蛋白质转导技术除了用于转导肿瘤特异抗体和药物进行抗肿瘤治疗以及制备抗感染或抗病毒的疫苗外。也已广泛应用于神经科学和与神经疾病相关的研究。     

多药耐药蛋白及其在难治性癫痈中作用的研究进展

难治性癫痫的耐药性研究已取得了许多突破性进展。近年发现,难治性癫痫与多药物耐药蛋白存在着密切联系。文中介绍3种主要多药耐药蛋白（P-糖蛋白、多药耐药相关蛋白1、主穹窿蛋白）的结构和功能,并对其近年在难治性癫痫耐药中作用的研究进展作一综述。     

Protein microarray analysis identifies cyclic nucleotide phosphodiesterase as an interactor of Nogo‐A

Nogo‐A, a neurite outgrowth inhibitor, is expressed exclusively on oligodendrocytes and neurons in the CNS. The central domain of Amino‐Nogo spanning amino acids 567–748 in the human Nogo‐A designated NIG, mediates persistent inhibition of axonal outgrowth and induces growth cone collapse by signaling through an as yet unidentified NIG receptor. We identified 82 NIG‐interacting proteins by screening a high‐density human protein microarray composed of 5000 proteins with a recombinant NIG protein as a probe. Following an intensive database search, we selected 12 neuron/oligodendrocyte‐associated NIG interactors. Among them, we verified the molecular interaction of NIG with 2′, 3′‐cyclic nucleotide 3′‐phosphodiesterase (CNP), a cell type‐specific marker of oligodendrocytes, by immunoprecipitation and cell imaging analysis. Although CNP located chiefly in the cytoplasm of oligodendrocytes might not serve as a cell‐surface NIG receptor, it could act as a conformational stabilizer for the intrinsically unstructured large segment of Amino‐Nogo.     

Protein kinases modulate the sensitivity of hippocampal neurons to nitric oxide toxicity and anoxia

Multiple processes lead to neuronal death after ischemia, but the generation of nitric oxide (NO) is a key component in this cascade of events. The mechanisms that regulate the extent of neuronal degeneration during anoxia and NO toxicity are multifactorial. Neuronal death may be modulated by the activity of signal transduction systems that influence the toxicity of NO or its metabolic products such as cGMP. The enzyme responsible for the production of NO, nitric oxide synthase (NOS), is phosphorylated by protein kinase C (PKC), the cAMP-dependent protein kinase (PKA), and the calcium/calmodulin-dependent protein kinase II (CaM-II). We examined in primary cultured hippocampal neurons whether the protein kinases PKC, PKA, CaM-II, and cGMP-dependent protein kinase modified the toxic effects of anoxia and NO. Down-regulation of PKC activity with PMA (1μM) increased hippocampal neuronal survival during anoxia and NO exposure from approximately 22% to 88%. Inhibitors of PKC activity 9H-7, H-8, sphingosine, and staurosporine also were neuroprotective. Down-regulation of PKC activity increased survival during anoxia even in the presence of the NOS inhibitor, N^ω-methyl-L-arginine. Thus, although down-regulation of PKC activity may increase neuronal survival by decreasing NOS activity, it also is likely that PKC contributes to ischemic neuronal death by mechanisms that are independent of NOS. Inhibition of the cGMP-dependent protein kinase activity, but not the activity of the CaM-II also was neuroprotective during NO administration. In contrast to the protective effects of inhibition of PKC and the cGMP-dependent protein kinase, activation rather than inhibition of PKA increased hippocampal neuronal survival during NO exposure. These results indicate that neuronal survival during anoxia and NO exposure is linked to the modulation of PKC, PKA, and cGMP-dependent protein kinase activity but is not dependent on the CaM-II pathway. Understanding the involvement of PKC, PKA, and the cGMP-dependent protein kinase in modulating the effect of neuronal death during ischemia and NO toxicity may help in directing future therapeutic modalities for cerebrovascular disease. © 1993 Wiley-Liss, Inc.