基因芯片检测自噬与凋亡的基因表达谱改变

目的:利用基因芯片研究自噬与凋亡关系,阐明两者间的分子调控机制.方法:采用4096条人类基因的cDNA芯片检测3-MA自噬抑制剂在诱导凋亡的人肝细胞株L02基因表达谱的改变,以探讨在自噬被抑制的情况下,凋亡的发生及其相关基因的变化.结果:L02细胞株cisplain凋亡诱导16小时的实验模型中,实验组在诱导凋亡前加入3-MA自噬抑制剂,诱导前后对照组与实验组相比,差异表达基因共151条.其中上调基因74条;下调基因77条.APG5基因无变化.结论:用基因表达芯片对3-MA自噬抑制剂在凋亡诱导的L02细胞株基因表达谱的改变进行高通量分析,能够有效地观察出凋亡基因及相关基因的表达.自噬被抑制的状态下,凋亡相关基因同样表达,说明3-MA自噬抑制剂并不能阻止凋亡的发生.     

Functional Divergence of Two Zebrafish Midkine Growth Factors Following Fish-Specific Gene Duplication

In mammals, the unique midkine (mdk) gene encodes a secreted heparin-binding growth factor with neurotrophic activity. Here, we show the presence of two functional mdk genes named mdka and mdkb in zebrafish and rainbow trout. Both midkine proteins are clearly different from the related pleiotrophin, which was also identified in zebrafish and other fishes. Zebrafish mdka and mdkb genes map to linkage groups LG7 and LG25, respectively, both presenting synteny to human chromosome 11, in which the unique human ortholog mdk is located. At least four other genes unique in mammals are also present as duplicates on LG7 and LG25. Phylogenetic and divergence analyses suggested that LG7/LG25 paralogs including mdka and mdkb have been formed at approximately the same time, early during the evolution of the fish lineage. Hence, zebrafish and rainbow trout mdka and mdkb might have been generated by an ancient block duplication, and might be remnants of the proposed fish-specific whole-genome duplication. In contrast to the ubiquitous expression of their mammalian counterpart, zebrafish mdka and mdkb are expressed in spatially restricted, mostly nonoverlapping patterns during embryonic development and strongly in distinct domains in the adult brain. Ectopic ubiquitous expression of both mdk genes in early zebrafish embryos caused completely distinct effects on neural crest and floorplate development. These data indicate that mdka and mdkb underwent functional divergence after duplication. This provides an outstanding model to analyze the molecular mechanisms that lead to differences in pathways regulating the formation of homologous embryonic structures in different vertebrates.     

建立cDNA微矩阵基因芯片技术并分析食管癌细胞系Eca109基因表达谱

为筛选食管癌相关基因,建立并应用cDNA微矩阵技术分析了食管癌细胞系ECa109基因表达谱.结果显示,在886条基因中,ECa109细胞系与正常食管上皮细胞间存在显著差异表达的基因有107条(12.08%),其中表达上调的51条(5.76%),表达下调的56条(6.32%).定量RT-PCR验证其中2个基因的表达水平,结果一致.建立T7 RNA聚合酶扩增技术,并对比分析了无扩增样品的基因表达谱,两者表现了较好的吻合性,这为cDNA微阵技术分析原发性食管癌微量肿瘤细胞的基因差异表达谱提供了方法学.食管癌细胞株ECa109基因表达谱的分析也使我们对食管癌病变机制有了一个初步的了解.     

人脂联素球状结构域基因在昆虫杆状病毒表达系统中的表达

目的利用杆状病毒表达系统表达人脂联素球状结构域（gAd）基因。方法以人基因组为模板,PCR法扩增人gad基因,将gAd基因与供体质粒pFastBacHTB连接,转化含有穿梭载体Bacmid的大肠杆菌DH10Bac。筛选转座成功的重组穿梭载体Bacmid—gAd,通过脂质体介导,转染昆虫细胞Sf9,经SDS-PAGE、免疫印迹法检测表达产物。结果重组杆状病毒感染的Sf9细胞形态变化明显,SDS-PAGE电泳结果显示,BacmidgAd组和对照组相比．在相对分子质量15000～25000之间多出一清晰的蛋白条带．免疫印迹法证实该条带能与相应的抗His标签抗体结合。结论人gAd基因成功在真核细胞中表达,为后续的实验研究奠定了基础。     

Gene Expression Profiles and Retinal Potential of Stem/Progenitor Cells Derived from Human Iris and Ciliary Pigment Epithelium

The aim of our study was to isolate and characterize the properties of neurospheres and differentiated cellular progeny derived from iris and ciliary pigment epithelial (IPE and CPE) cells of human cadaveric eyes. In this study we investigated the gene expression profiles of the stem/progenitor cells and the differentiated progeny derived from IPE and CPE cells, as the changes underlying differentiation of the stem/progenitor derived from the IPE and CPE cells from human cadaveric eye are essentially unknown. The IPE and CPE cells from human cadaver eyes were cultured in the presence of mitogens to generate neurospheres (NS) and the growth characteristics were evaluated. The Neurospheres (NS) were plated under conditions inducing differentiation and their potential was analyzed by RT-PCR, immunocytochemistry, calcium imaging studies and microarray studies to measure the changes involved in the process of differentiation. The IPE and CPE cells can generate NS containing progenitor cells in the presence of mitogens and were capable of producing different retinal cell types as demonstrated by RT-PCR and immunocytochemistry. The cluster analyses of the differentially expressed genes show the dynamic changes that occur during the course of IPE and CPE neurospheres differentiating into retinal progeny. The study gives clues towards the changes that occur during differentiation from NS into retinal progeny. In the present study we have demonstrated the expansion and maintenance of SCs from IPE and CPE of cadaveric eyes. These cells maintain their self-renewal properties and the ability to differentiate along retinal cell lineages and hence could be a practical source of donor cells for ex-vivo stem cell therapy during retinal degeneration.     

Interleukin Gene Expression in Mouse Preimplantation Development

Control of growth and differentiation during mammalian embryogenesis is regulated by growth factors from embryonic and/or maternal sources. Cytokines are polypeptide growth factors that are released by a variety of activated immune and nonimmune cells. To identify novel members of the cytokine family that could be involved in the growth and differentiation of the preimplantation embryo, we studied the expression pattern of several genes encoding cytokines and their receptors during mouse preimplantation development in vitro We found that poly(A)⁺ mRNAs for IL-1, IL-3, IL-6, IL-7, and TNFα are differentially expressed at several stages of mouse preimplantation development, including unfertilized oocytes. Immunostaining of preimplantation embryos using monoclonal antibodies specific for several cytokines and their receptors revealed that at least some of these mRNAs are translated into mature proteins during preimplantation development (IL-1, IL-6, and TNFα). Positive staining for IL-1 and IL-6 receptors was also detected at these stages of development. The controlled expression of these “inflammatory-type” cytokines and their receptors suggests a role for these growth factors during the early phases of mouse ontogeny.     

急性白血病的基因表达谱分析与亚型分类特征的鉴别

本研究基于生物信息学理论，运用模式识别方法和计算技术，对急性白血病的基因表达谱数据进行分析，研究急性白血病的亚型识别与分类信息基因选取问题。首先去除无关基因，然后利用浮动顺序搜索算法搜索特征空间生成候选特征子集，最后以支持向量机作为分类器进行急性白血病的亚型识别，并以误识率为依据鉴别出了5个包含完整分类信息的基因。实验结果表明，本研究鉴别出的5个信息基因能以100％的正确率准确识别急性白血病亚型。     

Longitudinal Immune Responses and Gene Expression Profiles in Type 1 Leprosy Reactions

Purpose

Leprosy, a chronic disease initiated by Mycobacterium leprae, is often complicated by acute inflammatory reactions. Although such episodes occur in at least 50 % of all leprosy patients and may cause irreversible nerve damage, no laboratory tests are available for early diagnosis or prediction of reactions. Since immune- and genetic host factors are critical in leprosy reactions, we hypothesize that identification of host-derived biomarkers correlated to leprosy reactions can provide the basis for new tests to facilitate timely diagnosis and treatment thereby helping to prevent tissue damage.

Methods

The longitudinal host response of a leprosy patient, who was affected by a type 1 reaction (T1R) after MDT-treatment, was studied in unprecedented detail, measuring cellular and humoral immunity and gene expression profiles to identify biomarkers specific for T1R.

Results

Cytokine analysis in response to M. leprae revealed increased production of IFN-γ, IP-10, CXCL9, IL-17A and VEGF at diagnosis of T1R compared to before T1R, whereas a simultaneous decrease in IL-10 and G-CSF was observed at T1R. Cytokines shifts coincided with a reduction in known regulatory CD39⁺CCL4⁺ and CD25^high T-cell subsets. Moreover, RNA expression profiles revealed that IFN-induced genes, (V)EGF, and genes associated with cytotoxic T-cell responses (GNLY, GZMA/B, PRF1) were upregulated during T1R, whereas expression of T-cell regulation-associated genes were decreased.

Conclusions

These data show that increased inflammation, vasculoneogenesis and cytotoxicity, perturbed T-cell regulation as well as IFN-induced genes play an important role in T1R and provide potential T1R-specific host biomarkers.     

人肺癌中多药抗性基因的表达

临床上肿瘤细胞的抗药性常与编码Ｐ－糖蛋白的多药抗性基因有关，为测定肿瘤中多药抗生基因的表达，我们用地高辛标记的ｃＤＮＡ探针通过原位杂交检测了２５例肺癌组织中多药抗性基因的表达，发现在１２例中多药性基因过度表达。结果提示临床上这些肿瘤对化疗水敏感可以用Ｐ－糖蛋白介导的药物外流来解释。     

小鼠IL-23基因的克隆和在逆转录病毒中的表达

从肿瘤组织 (含有活化的淋巴细胞 )提取总RNA ,经逆转录多聚酶链反应 (RT PCR )获得小鼠IL 2 3cDNA。经DNA测序分析 ,证实该片段与GeneBank记载的IL 2 3cDNA序列一致。将该目的基因插入LXSN逆转录病毒载体 ,并转染大肠杆菌DH5α中扩增 ,再感染 ψ2 (ecotropic )和PA317(amphotropic )两种包装细胞 ,经G4 18筛选后获得表达IL 2 3分子的PA317阳性细胞克隆。通过用PCR、RT PCR及Northernblot技术检测目的基因表达 ,结果表明 ,成功地将鼠IL 2 3cDNA插入逆转录病毒载体 ,经转染两种包装细胞产生了高表达IL 2 3的PA317细胞克隆。该克隆细胞产生的逆转录病毒可进一步用于转染肿瘤细胞 ,为制备肿瘤疫苗奠定了基础     

人GM－CSF基因在昆虫细胞中表达的研究

本工作构建的昆虫表达重组体ｐＡＣ６１０－ＧＭＴ，是在ＡｃＭＮＰＶ的Ｐｏｌｙｈｅｄｒｉｎ启动子控制下，表达去除了信号肽编码顺序的人ＧＭ－ＣＳＦ基因（ｃＤＮＡ）的转染载体。它与野生ＡｃＭＮＰＶ病毒ＤＮＡ共转染Ｓｆ２１细胞，经过筛选得到纯化的可表达人ＧＭ－ＣＳＦ的重组病毒株ｖＡｃＧＭＴ。其感染细胞总ＲＮＡ的Ｎｏｒｔｈｅｒｎ分析结果表明，重组病毒在ｍＲＮＡ水平有人ＧＭ－ＣＳＰ特异性表达，其表达水平在感染后４８ｈ时达高峰，７２ｈ未见明显下降。感染细胞裂解物的Ｗｅｓｔｅｒｎ－Ｂｌｏｔ分析和活性测定也证实其蛋白水平的表达，并有人ＧＭ－ＣＳＦ的生物学活性。