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1.
端粒酶通过催化端粒合成,保持端粒长度,从而保证细胞的持续分裂能力。其活性与生殖细胞和干细胞的增殖,体细胞的衰老和异常增殖、癌变等病理生理过程密切相关。逆转录催化亚单位hTERT的转录调节是端粒酶活性调节中的限速步骤,然而,目前对hTERT基因表达的具体机制仍不明了。研究基因转录调控的体内方法多通过瞬时转染及检测报告基因表达情况来分析启动子活性。由于众多因素的存在,这种瞬时转染的敏感性较低、重复性差。如将报告基因整合细胞基因组则容易受到基因组本身的影响。复制子Episome是一类可以在细胞中以染色体外形式独立复制的环状质粒。本研究中,我们运用EB病毒的复制子载体p220,建立了稳定的hTERT启动子介导-荧光素酶报告细胞系,并以此分析了c—MYC,p53基因对hTERT启动子的转录调节作用。  相似文献   

2.
目的 构建系列截短及缺失的hTERT启动子荧光素酶报告载体并验证其活性.方法 PCR扩增系列截短及缺失的hTERT启动子基因,克隆人pGL3-Basic质粒,构建荧光素酶报告载体.分别与pRL-TK内参照质粒共转染HepG2和COS-7细胞,48h后裂解细胞,双荧光素酶分析法检测启动子的活性.结果 成功构建系列截短及缺失的hTERT启动子报告载体,分别命名为pGL3B-895、pGL3B-371、pGL3B-DELS2、pGL3B-349、pGL3B-329、pGL3B-318、pGL3B-306.双荧光素酶报告基因检测结果显示在肝癌细胞和工程细胞中上述报告载体均具有启动子活性.结论 成功构建具有启动子活性的系列截短及缺失的hTERT启动子荧光素酶报告载体,为进一步探讨肝癌发生中人端粒酶逆转录酶表达调控机制提供必要的实验材料.  相似文献   

3.
目的探讨腺病毒介导的反义hTERT和野生型PTEN联合基因转染对恶性胶质瘤细胞生长的影响。方法用细菌内高效同源重组系统构建的含有hTERT反义序列及野生型PTEN的腺病毒在体内外单独或联合转染恶性胶质瘤细胞系U251,检测肿瘤细胞生长情况、端粒酶活性、蛋白表达、细胞周期变化等。结果在体外试验中单独或联合转染都能明显抑制肿瘤细胞的生长,以联合转染效果最明显,转染后第6天联合转染组的细胞生存率为37.6%,端粒酶活性水平和hTERT蛋白表达水平明显下降,分别为28.8TPG、0.2106,PIEN蛋白表达水平上升为0.9630;在体内试验中肿瘤生长也明显减慢。结论腺病毒介导的反义hTERT和野生型PTEN联合转染能明显抑制恶性胶质瘤细胞的生长。  相似文献   

4.
目的:克隆大鼠肺表面活性蛋白A(SPA)基因启动子并构建该启动子的荧光报告系统,探讨该启动子的活性及转录靶向性,为进一步研究SPA 基因的表达调控机制和探讨靶向性基因治疗奠定基础。方法:①从GenBank中获取大鼠SPA 基因序列,对其上游基因组序列进行计算机生物信息学分析,推断其上游序列约163bp的区域具有启动子功能。②利用PCR技术扩增SPA 基因上游启动子序列,将其亚克隆入pGL3-basic 中,构建pGL3-SPA 质粒,将其亚克隆于pGL3-control 中,构建pGL3-SPA-enhancer 质粒。③将构建pGL3-SPA质粒、pGL3-SPA-enhancer 质粒、pGL3-control质粒和pGL3-basic 质粒分别与内参质粒pRL-TK共转染入A549细胞和H441细胞, 用双荧光素酶报告系统检测该质粒在两种细胞中的荧光素酶活性表达。 结果:酶切及测序结果均证实成功克隆了SPA基因启动子序列,并已将该序列正确插入到荧光素酶报告基因系列载体中。重组的pGL3-SPA-enhancer 质粒、pGL3-SPA质粒转染H441 细胞后可以检测到荧光素酶的高表达。结论:成功构建了含有SPA 基因启动子序列的荧光素酶基因报告系统,证实了它在高表达SPA蛋白的细胞中有较高的转录活性, 为下一步研究SPA 基因功能及其转录调控以及探讨基因治疗的靶向性奠定了基础。  相似文献   

5.
本研究旨在克隆并分析阴道毛滴虫LAG1基因启动子,为进一步研究在细胞衰老过程中LAG1基因的转录调控提供实验资料。预测启动子所在区域,用PCR技术扩增启动子区序列,并分别克隆入荧光素酶报告基因载体pGL3-Basic及增强型绿色荧光蛋白报告基因载体pEGFP-1,用脂质体介导的方法瞬时转染EC109细胞,然后测定荧光素酶表达活性及观察绿色荧光蛋白的表达情况。结果表明在构建的6种荧光素酶报告基因表达体系及2种增强型绿色荧光蛋白报告基因表达体系中,表达载体pGL3-455(-455~ 55bp)、pGL3-417(-417~ 55bp)、pGL3-280(-280~ 55bp)、pGL3-202(-202~ 55bp)、pGL3-81(-81~ 55bp)的荧光素酶表达活性相近,均明显高于表达载体pGL3-47(-47~ 55bp)荧光素酶表达活性,而pGL3-47表达载体荧光素酶表达活性极低,与阴性对照活性相近,提示-47~ 55bp区无启动子活性。绿色荧光蛋白的表达情况也类似,pEGFP-81(-81~ 55bp)有明显的绿色荧光蛋白表达,而pEGFP-47(-47~ 55bp)和空载体pEGFP-1未见表达。因此-81~-47bp区域含有阴道毛滴虫LAG1基因转录所必需的基本启动子序列。  相似文献   

6.
人GDDR基因启动子的克隆和报告基因载体构建   总被引:2,自引:0,他引:2  
目的:克隆人GDDR基因的启动子;构建GDDR启动子的报告基因载体并进行活性分析.方法:设计合成GD-DR启动子引物,采用PCR技术从人基因组DNA中扩增GD-DR启动子;将扩增片段插入T载体并利用酶切与测序进行鉴定;亚克隆该基因至pGL3-Basic荧光报告基因载体;瞬时转染细胞,用双荧光素酶报告基因系统检测报告基因载体的活性.结果:PCR扩增得到人GDDR基因启动子;成功构建pGL3-GDDR-promoter 报告基因载体,测序结果表明启动子序列正确;双荧光素酶报告基因检测系统证实构建的报告基因载体具有启动子活性.结论:成功地构建人GDDR基因启动子的克隆及其报告基因载体的构建,为深入研究GDDR转录表达的调控机制提供基础.  相似文献   

7.
Wilson病ATP7B基因启动子区突变对基因表达的影响   总被引:5,自引:0,他引:5  
目的 探讨Wilson病ATP7B基因启动子区突变与Wilson发病的关系。方法 在48例患者中发现2例存在-183(C→T)突变,对发现存在突变的样本的DNA片段进行分离,克隆入pGL2荧光素酶报告基因,转染细胞,测定荧光素酶的活性,以野生型的ATP7B基因启动子作为对照,分析ATP7B基因启动子点突变对转录活性的影响。结果 含正常与含突变ATP7B启动子区序列的pGL2载体的荧光素酶转录活性相比较差异无统计学意义(n=3,P〉0.05)。结论 启动子区-183(C→T)突变不影响基因转录活性。提示该突变的意义有待进一步的探讨。  相似文献   

8.
目的探讨miR-98在涎腺腺样囊性癌组织中的表达及其对腺样囊性癌细胞系ACC-M增殖以及迁移能力的影响。方法通过实时PCR检测5例涎腺腺样囊性涎组织及癌旁正常组织miR-98的表达水平;将miR-98模拟物瞬时转入高转移腺样囊性癌细胞系(ACC-M)使miR-98过表达,并通过实时PCR方法验证;流式细胞仪分析转染后ACC-M细胞周期的改变,甲基噻唑基四唑比色法检测转染后ACC-M细胞的增殖,划痕实验检测转染后ACC-M细胞的迁移能力,免疫印迹法检测转染后ACC-M细胞细胞周期蛋白CyclinB与CDC2的表达变化。结果 miR-98在涎腺腺样囊性癌组织中的表达水平显著低于癌旁正常组织,P0.01。转染miR-98模拟物能够显著上调ACC-M细胞miR-98的表达水平,ACC-M细胞的S期比例明显下降,而G 0/G 1期的细胞明显增多,增殖受到明显抑制,迁移能力下降,显著降低ACC-M细胞CyclinB与CDC2的蛋白表达水平。结论过表达miR-98能够抑制涎腺腺样囊性癌细胞的增殖与迁移能力。  相似文献   

9.
目的构建干扰素调节因子3(IRF-3)rs2304204野生型及突变型重组质粒并比较二者启动子活性。为进一步研究IRF-3对HBV感染的影响打下基础。方法以人全血DNA为模板,扩增含rs2304204位点的IRF-3启动子区1355bp目的序列,插入pGL3-Basic载体中,构建rs2304204野生型的重组质粒(wIRF-3)。以wIRF-3为模板,利用基因定点突变试剂盒构建rs2304204突变型重组质粒(mIRF-3)。wIRF.3、mIRF-3和pGL3-Basic质粒分别转染HEK293细胞,采用双荧光素酶报告基因检测试剂盒检测荧光素酶活性,并计算荧光素酶相对活性单位(RLU)。结果成功构建IRF-3rs2304204野生型及突变型重组质粒,且wIRF-3质粒转染组RLU明显高于mIRF-3质粒转染组(P〈0.005)。结论野生型重组质粒的启动子活性明显高于突变型重组质粒,启动子活性的不同可能进而影响机体抗HBV感染的临床结局。  相似文献   

10.
目的构建含有p53蛋白结合位点的p21或survivin基因启动子区的荧光素酶报告基因重组质粒,并获得稳定转染的细胞模型用于抗肿瘤化合物筛选。方法将含有p53蛋白结合位点的p21或survivin启动子区序列连接到pGL4.17-basic载体上,分别获得报告基因重组质粒pGL4.17-p21和pGL4.17-survivin;将两种重组质粒分别转染A549细胞,经G418筛选获得稳定转染细胞株A549-p21和A549-survivin;对该细胞模型进行条件优化,并将可调节p53蛋白表达的多种抗肿瘤药物作用于稳定转染细胞,通过荧光素酶检测和western blot方法验证细胞模型用于药物筛选的可行性。结果成功建立了分别含有p21或survivin启动子报告基因的A549-p21和A549-survivin稳定细胞模型,多种抗肿瘤药物作用该细胞后能够通过调节p53蛋白表达而影响报告基因荧光素酶活性。结论构建的稳定转染细胞模型可以用于筛选以p53为靶点的抗肿瘤化合物。  相似文献   

11.
Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc2 (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.  相似文献   

12.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.  相似文献   

13.
About 1900, modern food selection and processing caused widespread epidemics of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse endemic disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for primates. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.  相似文献   

14.
15.
Newton H 《Medical history》2011,55(2):153-182
Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.  相似文献   

16.
Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.  相似文献   

17.
The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.  相似文献   

18.
HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.  相似文献   

19.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   

20.
Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.  相似文献   

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