共查询到20条相似文献，搜索用时 15 毫秒
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Okita K Nakagawa M Hyenjong H Ichisaka T Yamanaka S 《Science (New York, N.Y.)》2008,322(5903):949-953
Induced pluripotent stem (iPS) cells have been generated from mouse and human somatic cells by introducing Oct3/4 and Sox2 with either Klf4 and c-Myc or Nanog and Lin28 using retroviruses or lentiviruses. Patient-specific iPS cells could be useful in drug discovery and regenerative medicine. However, viral integration into the host genome increases the risk of tumorigenicity. Here, we report the generation of mouse iPS cells without viral vectors. Repeated transfection of two expression plasmids, one containing the complementary DNAs (cDNAs) of Oct3/4, Sox2, and Klf4 and the other containing the c-Myc cDNA, into mouse embryonic fibroblasts resulted in iPS cells without evidence of plasmid integration, which produced teratomas when transplanted into mice and contributed to adult chimeras. The production of virus-free iPS cells, albeit from embryonic fibroblasts, addresses a critical safety concern for potential use of iPS cells in regenerative medicine. 相似文献
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Stadtfeld M Nagaya M Utikal J Weir G Hochedlinger K 《Science (New York, N.Y.)》2008,322(5903):945-949
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Induced pluripotent stem cells generated from patients with ALS can be differentiated into motor neurons 总被引：3，自引：0，他引：3
Dimos JT Rodolfa KT Niakan KK Weisenthal LM Mitsumoto H Chung W Croft GF Saphier G Leibel R Goland R Wichterle H Henderson CE Eggan K 《Science (New York, N.Y.)》2008,321(5893):1218-1221
The generation of pluripotent stem cells from an individual patient would enable the large-scale production of the cell types affected by that patient's disease. These cells could in turn be used for disease modeling, drug discovery, and eventually autologous cell replacement therapies. Although recent studies have demonstrated the reprogramming of human fibroblasts to a pluripotent state, it remains unclear whether these induced pluripotent stem (iPS) cells can be produced directly from elderly patients with chronic disease. We have generated iPS cells from an 82-year-old woman diagnosed with a familial form of amyotrophic lateral sclerosis (ALS). These patient-specific iPS cells possess properties of embryonic stem cells and were successfully directed to differentiate into motor neurons, the cell type destroyed in ALS. 相似文献
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猪L-Myc基因的分子克隆及在细胞重编程中的应用 总被引：1，自引：1，他引：0
【目的】克隆猪L-Myc基因,并在蛋白水平表达的情况下探索其在细胞重编程中的作用,为深入研究猪L-Myc基因替代c-Myc诱导多能干细胞（induced pluripotent stem cell,iPSC）奠定基础。【方法】先通过NCBI序列比对,采用RT-PCR克隆猪L-Myc基因cDNA,生物信息学分析猪L-Myc基因与人和小鼠的同源性,构建融合表达载体pEGFP/L-Myc-C1,通过载体转染和免疫印记检测猪L-Myc基因cDNA的蛋白水平表达;再将L-Myc基因装入逆转录病毒载体中,分别使用不同的转录因子诱导猪胎儿成纤维细胞（porcine embryo fibroblast,PEF）,通过形态变化和碱性磷酸酶（AP）染色验证猪L-Myc基因在细胞重编程中的作用。【结果】①获得了1 113 bp的猪L-Myc基因cDNA,编码364个氨基酸,理论分子质量为40 kD;②生物信息学分析显示猪L-Myc基因与人和小鼠高度同源;③免疫印记检测结果说明猪L-Myc基因cDNA能够在蛋白水平表达;④细胞诱导试验和AP染色结果显示转录因子Oct4、Sox2、Klf4和L-Myc（OSKL）组合诱导的细胞阳性克隆率明显高于Oct4、Sox2和Klf4（OSK）组合的阳性克隆率。【结论】获得了猪L-Myc基因,并且该基因在蛋白水平表达且在细胞重编程过程中起到了重要的作用。 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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诱导多能干细胞（induced pluripotent stem cells, iPS）是借助基因导入技术将某些转录因子导入人或动物的体细胞,使体细胞重编程而得到的多能性细胞。iPS细胞来源丰富,研究表明利用不同的载体诱导系统或不同的转录因子组合,多种体细胞都可被重编程为iPS细胞,如成纤维细胞、肝细胞、角质细胞及脐带血细胞等。作为干细胞中新的一员,iPS细胞在克隆形态、基因表达模式、表面标志物、拟胚体形成、畸胎瘤及嵌合体形成（小鼠）、分化能力等方面与胚胎干细胞（embryonic stem cell, ESC）非常相似。与胚胎干细胞一样,在特定的诱导条件下,iPS细胞在体外可被诱导分化为多种细胞,如心肌细胞、血细胞、生殖细胞等,进一步拉近了干细胞和临床疾病治疗的距离,iPS细胞也成为细胞治疗及组织器官再生最有前景的种子细胞,在细胞替代性治疗、发病机理研究及新药筛选方面具有潜在价值。雄性不育不仅影响人类正常健康生活,对畜牧业的发展也极为不利。国内外的研究成果表明,给予适当的诱导物及诱导条件,人和小鼠的iPS细胞体外可被诱导分化为原始生殖细胞（primordial germ cells, PGCs）、精子细胞及其前体细胞。这些研究不仅避免了胚胎干细胞研究领域存在的取材困难、免疫排斥和伦理道德等问题,还为揭示雄性生殖细胞的发育机制及研究雄性不育提供了较好的研究平台。由人iPS细胞诱导得到的雄性配子可为患者提供自身的雄性配子产生后代,避免了免疫排斥问题,为未来治疗雄性不育带来曙光。iPS细胞体外诱导分化技术对现代畜牧业发展也具有巨大的潜在应用价值,可进行转基因动物的生产。现从不同的诱导剂、不同的培养条件及iPS细胞体外诱导分化优势等方面,对iPS细胞体外定向诱导分化为雄性生殖细胞的研究进展及应用前景进行综述和展望。 相似文献
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Retroviral DNA integration is catalyzed by the viral protein integrase. Here, it is shown that DNA-dependent protein kinase (DNA-PK), a host cell protein, also participates in the reaction. DNA-PK-deficient murine scid cells infected with three different retroviruses showed a substantial reduction in retroviral DNA integration and died by apoptosis. Scid cell killing was not observed after infection with an integrase-defective virus, suggesting that abortive integration is the trigger for death in these DNA repair-deficient cells. These results suggest that the initial events in retroviral integration are detected as DNA damage by the host cell and that completion of the integration process requires the DNA-PK-mediated repair pathway. 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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Generalized potential of adult neural stem cells 总被引：1，自引：0，他引：1
Clarke DL Johansson CB Wilbertz J Veress B Nilsson E Karlström H Lendahl U Frisén J 《Science (New York, N.Y.)》2000,288(5471):1660-1663
The differentiation potential of stem cells in tissues of the adult has been thought to be limited to cell lineages present in the organ from which they were derived, but there is evidence that some stem cells may have a broader differentiation repertoire. We show here that neural stem cells from the adult mouse brain can contribute to the formation of chimeric chick and mouse embryos and give rise to cells of all germ layers. This demonstrates that an adult neural stem cell has a very broad developmental capacity and may potentially be used to generate a variety of cell types for transplantation in different diseases. 相似文献
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Primordial germ cells (PGCs) are regarded as unipotent cells that can produce only either spermatogonia or oocytes. However, PGCs can be converted into the pluripotent state by first dedifferentiation to embryonic germ cells and then by reprogramming to induce them to become pluripotent stem cells (iPSCs). These two stages can be completely implemented with mouse cells. However, authentic porcine iPSCs have not been established. Here, we discuss recent advances in the stem cell field for obtaining iPSCs from PGCs. This knowledge will provide some clues which will contribute to the regulation of reprogramming to pluripotency in farm species. 相似文献
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Wakayama T Tabar V Rodriguez I Perry AC Studer L Mombaerts P 《Science (New York, N.Y.)》2001,292(5517):740-743
Embryonic stem (ES) cells are fully pluripotent in that they can differentiate into all cell types, including gametes. We have derived 35 ES cell lines via nuclear transfer (ntES cell lines) from adult mouse somatic cells of inbred, hybrid, and mutant strains. ntES cells contributed to an extensive variety of cell types, including dopaminergic and serotonergic neurons in vitro and germ cells in vivo. Cloning by transfer of ntES cell nuclei could result in normal development of fertile adults. These studies demonstrate the full pluripotency of ntES cells. 相似文献
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采用大鼠心肌条件培养基对昆明白小鼠胚胎干细胞进行分离、消化传代、培养鉴定等,研究大鼠心肌条件培养基在昆明白小鼠胚胎干细胞分离培养中的作用效果。结果显示,SD大鼠心肌条件培养基在昆明白小鼠3.5d囊胚胚胎干细胞集落分离中,所分离的昆明白小鼠胚胎干细胞集落具有岛屿状生长,隆起于饲养层上;碱性磷酸酶染色为强阳性;体外分化可形成类胚体状结构,贴壁的类胚体周边会出现许多分化的上皮样细胞或单个散在的细胞;经过常规冻存传代的胚胎干细胞集落具有较为一致的生长形态,并呈现胚胎干细胞集落所特有的岛屿状生长形态;对传至第5代的小鼠胚胎干细胞集落进行核型分析,小鼠胚胎干细胞核型正常率大于75%。试验证实,SD大鼠心肌条件培养基在昆明白小鼠胚胎干细胞分离培养过程中效果较好。 相似文献
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Induced pluripotent stem cell lines derived from human somatic cells 总被引：10，自引：0，他引：10
Yu J Vodyanik MA Smuga-Otto K Antosiewicz-Bourget J Frane JL Tian S Nie J Jonsdottir GA Ruotti V Stewart R Slukvin II Thomson JA 《Science (New York, N.Y.)》2007,318(5858):1917-1920
Somatic cell nuclear transfer allows trans-acting factors present in the mammalian oocyte to reprogram somatic cell nuclei to an undifferentiated state. We show that four factors (OCT4, SOX2, NANOG, and LIN28) are sufficient to reprogram human somatic cells to pluripotent stem cells that exhibit the essential characteristics of embryonic stem (ES) cells. These induced pluripotent human stem cells have normal karyotypes, express telomerase activity, express cell surface markers and genes that characterize human ES cells, and maintain the developmental potential to differentiate into advanced derivatives of all three primary germ layers. Such induced pluripotent human cell lines should be useful in the production of new disease models and in drug development, as well as for applications in transplantation medicine, once technical limitations (for example, mutation through viral integration) are eliminated. 相似文献
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Differentiation of embryonic stem cells to insulin-secreting structures similar to pancreatic islets
Lumelsky N Blondel O Laeng P Velasco I Ravin R McKay R 《Science (New York, N.Y.)》2001,292(5520):1389-1394
Although the source of embryonic stem (ES) cells presents ethical concerns, their use may lead to many clinical benefits if differentiated cell types can be derived from them and used to assemble functional organs. In pancreas, insulin is produced and secreted by specialized structures, islets of Langerhans. Diabetes, which affects 16 million people in the United States, results from abnormal function of pancreatic islets. We have generated cells expressing insulin and other pancreatic endocrine hormones from mouse ES cells. The cells self-assemble to form three-dimensional clusters similar in topology to normal pancreatic islets where pancreatic cell types are in close association with neurons. Glucose triggers insulin release from these cell clusters by mechanisms similar to those employed in vivo. When injected into diabetic mice, the insulin-producing cells undergo rapid vascularization and maintain a clustered, islet-like organization. 相似文献
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A karyotypic analysis was performed on seven independently derived clones of primary rat embryo cells transformed by the ras oncogene plus the cooperating oncogene myc. The transfected oncogenes were sometimes present in amplified copy number, with heterogeneity in the levels of amplification. Some chromosomal features, such as aberrantly banding regions and double-minute chromosomes, typical of cells carrying amplified genes, were also seen in three of the seven cell lines. Underlying this heterogeneity there was an unexpected finding. All seven lines showed a common integration site for ras on the q arm of rat chromosome 3 (3q12), though some lines also had other sites of integration. In four of the lines integration of ras was accompanied by deletion of the p arm of chromosome 3 or its possible translocation to chromosome 12. 相似文献
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Specific expression of a tyrosine kinase gene, blk, in B lymphoid cells 总被引：36，自引：0，他引：36
Several pathways of transmembrane signaling in lymphocytes involve protein-tyrosine phosphorylation. With the exception of p56lck, a tyrosine kinase specific to T lymphoid cells that associates with the T cell transmembrane proteins CD4 and CD8, the kinases that function in these pathways are unknown. A murine lymphocyte complementary DNA that represents a new member of the src family has now been isolated and characterized. This complementary DNA, termed blk (for B lymphoid kinase), specifies a polypeptide of 55 kilodaltons that is related to, but distinct from, previously identified retroviral or cellular tyrosine kinases. The protein encoded by blk exhibits tyrosine kinase activity when expressed in bacterial cells. In the mouse and among cell lines, blk is specifically expressed in the B cell lineage. The tyrosine kinase encoded by blk may function in a signal transduction pathway that is restricted to B lymphoid cells. 相似文献