共查询到20条相似文献，搜索用时 15 毫秒
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黄汉军 《甘肃农业大学学报》2003,38(2):127-132,139
胚胎干细胞(embryonic stem cells, ES)是指从桑椹胚或附植前囊胚内细胞团分离的多潜能细胞,它具有体外培养无限增殖、自我更新和多向分化的特性。无论在体外还是体内环境,ES细胞都能被诱导分化为机体几乎所有的细胞类型。自1981年Evans和Kaufman首次成功分离小鼠ES细胞,国内外研究人员已在仓鼠、大鼠、兔、猪、牛、绵羊、山羊、水貂、恒河猴、美洲长尾猴以及人类都分离获得了ES细胞,而且已经证明小鼠ES细胞可以分化为心肌细胞、造血细胞、卵黄囊细胞、骨髓细胞、平滑肌细胞、脂肪细胞、软骨细胞、成骨细胞、内皮细胞、黑素细胞、神经细胞、神经胶质细胞、少突胶质细胞、淋巴细胞、胰岛细胞、滋养层细胞等。人类ES细胞也可以分化为滋养层细胞、神经细胞、神经胶质细胞、造血细胞、心肌细胞等。ES细胞不仅可以作为体外研究细胞分化和发育调控机制的模型,而且还可以作为一种载体,将通过同源重组产生的基因组的定点突变导入个体,更重要的是,ES细胞将会给人类移植医学带来一场革命。 相似文献
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Phillips RL Ernst RE Brunk B Ivanova N Mahan MA Deanehan JK Moore KA Overton GC Lemischka IR 《Science (New York, N.Y.)》2000,288(5471):1635-1640
Blood cell production originates from a rare population of multipotent, self-renewing stem cells. A genome-wide gene expression analysis was performed in order to define regulatory pathways in stem cells as well as their global genetic program. Subtracted complementary DNA libraries from highly purified murine fetal liver stem cells were analyzed with bioinformatic and array hybridization strategies. A large percentage of the several thousand gene products that have been characterized correspond to previously undescribed molecules with properties suggestive of regulatory functions. The complete data, available in a biological process-oriented database, represent the molecular phenotype of the hematopoietic stem cell. 相似文献
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The immune system develops in waves during ontogeny; it is initially populated by cells generated from fetal hematopoietic stem cells (HSCs) and later by cells derived from adult HSCs. Remarkably, the genetic programs that control these two distinct stem cell fates remain poorly understood. We report that Lin28b is specifically expressed in mouse and human fetal liver and thymus, but not in adult bone marrow or thymus. We demonstrate that ectopic expression of Lin28 reprograms hematopoietic stem/progenitor cells (HSPCs) from adult bone marrow, which endows them with the ability to mediate multilineage reconstitution that resembles fetal lymphopoiesis, including increased development of B-1a, marginal zone B, gamma/delta (γδ) T cells, and natural killer T (NKT) cells. 相似文献
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Expression of a retrovirus encoding human HPRT in mice 总被引：32，自引：0，他引：32
A D Miller R J Eckner D J Jolly T Friedmann I M Verma 《Science (New York, N.Y.)》1984,225(4662):630-632
Transmissible retroviruses encoding human hypoxanthine phosphoribosyltransferase (HPRT) were used to infect mouse bone marrow cells in vitro, and the infected cells were transplanted into mice. Both active human HPRT-protein and chronic HPRT-virus production were detected in hematopoietic tissue of the mice, showing transfer of the gene. These results indicate the possible use of retroviruses for somatic cell therapy. 相似文献
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Ramalho-Santos M Yoon S Matsuzaki Y Mulligan RC Melton DA 《Science (New York, N.Y.)》2002,298(5593):597-600
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Clinically successful hematopoietic cell transplantation is dependent on hematopoietic stem and progenitor cells. Here we identify the matricellular protein Nephroblastoma Overexpressed (Nov, CCN3) as being essential for their functional integrity. Nov expression is restricted to the primitive (CD34) compartments of umbilical vein cord blood, and its knockdown in these cells by lentivirus-mediated RNA interference abrogates their function in vitro and in vivo. Conversely, forced expression of Nov and addition of recombinant Nov protein both enhance primitive stem and/or progenitor activity. Taken together, our results identify Nov (CCN3) as a regulator of human hematopoietic stem or progenitor cells. 相似文献
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The members of the ADAR (adenosine deaminase acting on RNA) gene family are involved in site-selective RNA editing that changes adenosine residues of target substrate RNAs to inosine. Analysis of staged chimeric mouse embryos with a high contribution from embryonic stem cells with a functional null allele for ADAR1 revealed a heterozygous embryonic-lethal phenotype. Most ADAR1+/- chimeric embryos died before embryonic day 14 with defects in the hematopoietic system. Our results suggest the importance of regulated levels of ADAR1 expression, which is critical for embryonic erythropoiesis in the liver. 相似文献
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The SCID-hu mouse: murine model for the analysis of human hematolymphoid differentiation and function 总被引：143，自引：0，他引：143
J M McCune R Namikawa H Kaneshima L D Shultz M Lieberman I L Weissman 《Science (New York, N.Y.)》1988,241(4873):1632-1639
The study of human hematopoietic cells and the human immune system is hampered by the lack of a suitable experimental model. Experimental data are presented showing that human fetal liver hematopoietic cells, human fetal thymus, and human fetal lymph node support the differentiation of mature human T cells and B cells after engraftment into mice with genetically determined severe combined immunodeficiency. The resultant SCID-hu mice are found to have a transient wave of human CD4+ and CD8+ T cells and human IgG (immunoglobulin G) in the peripheral circulation. The functional status of the human immune system within this mouse model is not yet known. 相似文献
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Aoi T Yae K Nakagawa M Ichisaka T Okita K Takahashi K Chiba T Yamanaka S 《Science (New York, N.Y.)》2008,321(5889):699-702
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MicroRNAs modulate hematopoietic lineage differentiation 总被引：8，自引：0，他引：8
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Transplantation of normal bone marrow cells to a gray collie dog with cyclic neutropenia resulted in normal granulocytopoiesis. The finding suggests that cyclic neutropenia occurs because the hematopoietic stem cells are defective. Because of the similarity of human and canine cyclic neutropenia, it also suggests that the human disease may be curable by marrow transplantation. 相似文献
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Somatic cell hybrid between the established human line D98 (presumptive HeLa) and 3T3 总被引：15，自引：0，他引：15
Somatic cell hybrids have been made between an established human cell line with a long culture history and established mouse fibroblast line. When first analyzed, the hybrid cells contained nearly twice as many mouse chromosomes as the mouse parent line and a human chromosome complemnent of about half that of the human parent. There was further loss of human chromosomes on continued cultivation. This behavior resembles that of other human mouse hybrids and appears to be characteristic of the human-mouse combination. However, the number of human chromosomes is greater than in hybrids made from human diploid fibroblasts. Some clones contain more than a haptoid quantity of human DNA per cell and should synthesize a much greater number of human gene products. 相似文献
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Cheng T Rodrigues N Shen H Yang Y Dombkowski D Sykes M Scadden DT 《Science (New York, N.Y.)》2000,287(5459):1804-1808
Relative quiescence is a defining characteristic of hematopoietic stem cells, while their progeny have dramatic proliferative ability and inexorably move toward terminal differentiation. The quiescence of stem cells has been conjectured to be of critical biologic importance in protecting the stem cell compartment, which we directly assessed using mice engineered to be deficient in the G1 checkpoint regulator, cyclin-dependent kinase inhibitor, p21cip1/waf1 (p21). In the absence of p21, hematopoietic stem cell proliferation and absolute number were increased under normal homeostatic conditions. Exposing the animals to cell cycle-specific myelotoxic injury resulted in premature death due to hematopoietic cell depletion. Further, self-renewal of primitive cells was impaired in serially transplanted bone marrow from p21-/- mice, leading to hematopoietic failure. Therefore, p21 is the molecular switch governing the entry of stem cells into the cell cycle, and in its absence, increased cell cycling leads to stem cell exhaustion. Under conditions of stress, restricted cell cycling is crucial to prevent premature stem cell depletion and hematopoietic death. 相似文献
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Gene transfer and expression of human phenylalanine hydroxylase 总被引：18，自引：0，他引：18
Phenylketonuria (PKU) is caused by a genetic deficiency of the enzyme phenylalanine hydroxylase (PAH). A full-length complementary DNA clone of human PAH was inserted into a eukaryotic expression vector and transferred into mouse NIH3T3 cells which do not normally express PAH. The transformed mouse cells expressed PAH messenger RNA, immunoreactive protein, and enzymatic activity that are characteristic of the normal human liver products, demonstrating that a single gene contains all of the necessary genetic information to code for functional PAH. These results support the use of the human PAH probe in prenatal diagnosis and detection of carriers, to provide new opportunities for the biochemical characterization of normal and mutant enzymes, and in the investigation of alternative genetic therapies for PKU. 相似文献
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诱导性多能干细胞的研究及应用 总被引：1，自引：0，他引：1
自从小鼠的胚胎成纤维细胞和鼠尾成纤维细胞重编程成为诱导多能干细胞（induced pluripotent stem cells,iPSCs）以来,iPS的研究成了干细胞研究领域的热点。与胚胎干细胞相比,iPS细胞有操作简便和高稳定性等优点可以应用于,如创建人类疾病的遗传模型,培育转基因动物用于器官移植,改善动物生产性状和抗病性,以及生物制药等领域。另外,iPSCs的产生对于解决长期以来干细胞研究领域的伦理问题和免疫排斥问题有巨大的意义,iPS结合基因治疗和细胞移植疗法的成果已经应用到了动物疾病模型上。iPS细胞技术给病人特定细胞治疗和基因针对性药品研制带来了巨大的前景。此外,该技术也提供了iPS细胞重编程机制和人类疾病的病理过程研究的新平台。然而,现阶段多能干细胞的研究只是开辟了一个新的领域,iPS技术要应用于临床还有很多工作要做。本文主要针对iPSCs的研究现状与应用前景进行讨论。 相似文献
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Our understanding of leukemia development and progression has been hampered by the lack of in vivo models in which disease is initiated from primary human hematopoietic cells. We showed that upon transplantation into immunodeficient mice, primitive human hematopoietic cells expressing a mixed-lineage leukemia (MLL) fusion gene generated myeloid or lymphoid acute leukemias, with features that recapitulated human diseases. Analysis of serially transplanted mice revealed that the disease is sustained by leukemia-initiating cells (L-ICs) that have evolved over time from a primitive cell type with a germline immunoglobulin heavy chain (IgH) gene configuration to a cell type containing rearranged IgH genes. The L-ICs retained both myeloid and lymphoid lineage potential and remained responsive to microenvironmental cues. The properties of these cells provide a biological basis for several clinical hallmarks of MLL leukemias. 相似文献
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试验尝试构建成体细胞同小鼠早期胚胎的嵌合共生胚胎.取成年人皮肤组织的成纤维细胞,慢病毒转染皮肤成纤维细胞标记EGFP荧光蛋白,同小鼠早期8-细胞胚胎进行嵌合.结果显示慢病毒高效标记人皮肤成纤维细胞表达EGFP荧光蛋白,通过皮肤成纤维细胞与小鼠胚胎干细胞形成的拟胚体环境作用后,皮肤成纤维细胞成功与小鼠胚胎形成嵌合胚,嵌合囊胚形成率为38.08%,表达EGFP荧光蛋白的皮肤成纤维细胞能够嵌合到小鼠胚胎的不同部位.嵌合胚在胚胎干细胞分离培养环境下进行培养,嵌合到小鼠内细胞团的皮肤成纤维细胞参与小鼠内细胞团的组成,参与小鼠内细胞团组成的胚胎占嵌合胚比率为1.74%.小鼠胚胎干细胞拟胚体环境作用可以成功介导人皮肤成纤维细胞同小鼠早期胚胎形成嵌合共生体系. 相似文献
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Organization of the human and mouse low-affinity Fc gamma R genes: duplication and recombination 总被引：19，自引：0，他引：19
W Q Qiu D de Bruin B H Brownstein R Pearse J V Ravetch 《Science (New York, N.Y.)》1990,248(4956):732-735
Receptors for immunoglobulin G immune complexes (Fc gamma RII and Fc gamma RIII) are expressed on most hematopoietic cells and show much structural and functional diversity. In order to determine the genetic basis for this diversity, a family of genes encoding the human and mouse receptors was isolated and characterized. Humans have five distinct genes for low-affinity Fc gamma Rs, in contrast to two in the mouse. With the use of yeast artificial chromosomes, the genes encoding the human receptors were oriented and linked, which established the structure of this complex locus. Comparison of the human and mouse genes generated a model for the evolutionary amplification of this locus. 相似文献