摘要
端粒对于细胞保持染色体的稳定性和分裂能力有着重要的作用。在人类退行性疾病的发生中,端粒酶的活性降低或者缺失所导致的细胞端粒的逐渐缩短产生了非常重要的影响。体细胞重编程作为一种可能的再生医疗的手段,未来将对退行性疾病的临床治疗产生重要的影响。体细胞核移植(Somatic cell nuclear transfer, SCNT)和诱导型重编程(Induced pluripotent stem cell, iPS)是体细胞重编程最主要的两种技术。然而这两种技术重编程具有端粒功能障碍及相关病症的供体细胞的能力还有待探索。
端粒延长对体细胞重获多能性有重要的意义。iPS细胞诱导过程中端粒酶是端粒延长的主要机制。iPS细胞诱导过程中端粒延长十分缓慢,iPS细胞在建系后还需要数代的细胞传代才能使端粒长度达到与胚胎干细胞相似的水平。最近的研究表明在iPS细胞诱导过程中过表达早期胚胎重编程因子Zscan4可显著提高iPS细胞端粒的延长效率和iPS细胞的诱导效率,同时显著提高所获得的iPS细胞的分化潜能。SCNT技术利用卵母细胞的重编程因子进行体细胞重编程,而iPS技术则利用的是有限的几个重编程因子。因此SCNT技术重编程具有端粒功能障碍及相关病症的供体细胞的能力有可能比iPS技术更强。本研究利用端粒酶敲除(Terc-/-)小鼠作为模型来验证这个推测。第三代Terc-/-小鼠表现出明显的与端粒缩短相关的缺陷,主要表型有体型减小、寿命缩短,以及很多重要的器官如小肠、脾脏发生提早萎缩。本研究分别建立了来自第二代(Generation2, G2)和第三代(Generation3, G3) Terc-/小鼠的核移植胚胎干细胞(Nuclear transfer embryonic stem cells, ntESCs)和诱导型多能干细胞(Induced pluripotent stem cells, iPSCs)。与Terc-/-iPSCs相比,Terc-/-ntESCs表现出更强的分化能力和自我更新能力。实验结果表明在端粒酶缺失的情况下核移植克隆胚胎的发育过程中端粒有显著的延长,而在iPSCs诱导过程中端粒的长度没有显著的变化。G3Terc-/-ntESCs的端粒功能较来源的体细胞有明显的改善,而G3Terc-/-iPSCs的端粒功能较来源的体细胞发生了进一步的损伤,表现为极短端粒和染色体末端连接的比例增加。此外,G3Terc-/-iPSCs的线粒体功能也发生了进一步的损伤。G3Terc-/iPSCs的线粒体呼吸能力下降,细胞内积累了大量的活性氧并导致线粒体基因组的突变频率增加。而在G3Terc-/-ntESCs中,这些线粒体的功能缺陷是有明显改善的。有趣的是,G3Terc-/-iPSCs的线粒体功能异常不是由PGC-1α的表达抑制引起的。但是在G3Terc-/-iPSCs的分化过程中,PGC-1α的激活被抑制影响了线粒体的成熟。而在G3Terc-/-ntESCs的分化过程中,PGC-1α的表达升高足以使细胞内的线粒体分化为成熟的线粒体。
以上的实验结果表明在端粒酶缺失的情况下,核移植技术能激活不依赖于端粒酶的机制进行端粒延长,并且能显著改善线粒体功能缺陷。因此核移植技术重编程有端粒和线粒体功能缺陷的供体细胞的能力比诱导型重编程技术更强。将来的研究可利用核移植技术发现新的重编程因子,从而优化现在的诱导型重编程技术,并且提高来自端粒和线粒体功能异常的病人的iPSCs的质量。
Telomeres play key roles in maintaining chromosome stability and cell replicative capacity. Progressive telomere shortening due to absent or insufficient telomerase activity plays important roles in driving degenerative pathologies in humans. Somatic cell reprogramming holds great promise in future clinical applications, especially in the treatment of degeneration disorders. Somatic cell nuclear transfer (SCNT) and induced pluripotent stem cells (iPSCs) represent two major approaches for cell reprogramming. However, little is known regarding the ability of these two strategies to rejuvenate cells from donors with telomere dysfunction-related syndromes.
Telomere re-elongation is of great importance for the acquisition of pluripotency during reprogramming. Telomere lengthening during iPSCs induction mainly relies on telomerase, the action of which is a very time consuming process, and iPSCs telomeres need postreprogramming to reach the length resembling that of ESCs. Recently, oocyte-derived factor Zscan4has been shown to dramatically elongates telomeres during iPSCs induction and thus improves the reprogramming efficiency and the quality of iPSCs. Therefore, we speculate that SCNT utilizing factors in occytes to reprogramming somatic cells may rejuvenate cells with dysfuntioncal telomeres in a manner superior to that of iPSCs technology with only a few reprogramming factors. Here, we utilized late generation telomerase-deficient(Terc-/-) mice as a model to probe this question. In the third generation Terc-/-mice, disease states associated with short telomeres become evident, with a reduced body size, a decreased life span and atrophy of multiple tissues such as small intestine, spleen and testicles. SCNT-derived embryonic stem cells (ntESCs) and iPSCs were successfully derived from second generation (G2) and third generation (G3) Terc-/-mice, and ntESCs showed better differentiation potential and self-renewal ability. Telomeres lengthened extensively in cloned embryos while remained or slightly increased in the process of iPSCs induction. Furthermore, G3Terc-/-ntESCs exhibited improvement of telomere capping function as evidenced by decreased signal free ends and chromosome end-to-end fusion events. In contrast, there was a further decline of telomere capping function in G3Terc-/-iPSCs. In addition to telomere dysfunction, mitochondria function was severely impaired in G3Terc-/-iPSCs as evidenced by oxygen consumption rate (OCR) decline, reactive oxygen species (ROS) accumulation and dramatically increased mitochondria genome mutations while these deficiencies were greatly mitigated in G3Terc-/-ntESCs. Interestingly, PGC-la expression appeared to be irrelevant to the mitochondrial dysfunction in G3Terc-/-iPSCs. However, impaired mitochondrial maturation in differentiating G3Tern-/-iPSCs was associated with a failure of PGC-1α reactivation, which was mitigated in G3Terc-/-ntESCs.
In summary, this study demonstrates that SCNT is superior to transcription factors mediated reprogramming in rejuvenating somatic cells with telomere and mitochondria defects. The breakthrough recently achieved in human SCNT studies further suggests that the identification of novel reprogramming factors might greatly improve the current iPSCs technology and enhance the quality of human iPSCs derived particularly from patients with telomere and mitochondria defects.
引文
Aasen, T., Raya, A., Barrero, M.J., Garreta, E., Consiglio, A., Gonzalez, F., Vassena, R., Bilic, J., Pekarik, V., Tiscornia, G., et al. (2008). Efficient and rapid generation of induced pluripotent stem cells from human keratinocytes. Nat Biotechnol 26,1276-1284.
Atzmon, G., Cho, M., Cawthon, R.M., Budagov, T., Katz, M., Yang, X.M., Siegel, G., Bergman, A., Huffman, D.M., Schechter, C.B., et al. (2010). Genetic variation in human telomerase is associated with telomere length in Ashkenazi centenarians. Proc Natl Acad Sci USA 107,1710-1717.
Ayyasamy, V., Owens, K.M., Desouki, M.M., Liang, P., Bakin, A., Thangaraj, K., Buchsbaum, D.J., LoBuglio, A.F., and Singh, K.K. (2011). Cellular model of Warburg effect identifies tumor promoting function of UCP2 in breast cancer and its suppression by genipin. PLoS One 6, e24792.
Azuara, V., Perry, P., Sauer, S., Spivakov, M., Jorgensen, H.F., John, R.M., Gouti, M., Casanova, M., Warnes, G., Merkenschlager, M., et al. (2006). Chromatin signatures of pluripotent cell lines. Nat Cell Biol 8,532-538.
Bae, B.I., Xu, H., Igarashi, S., Fujimuro, M., Agrawal, N., Taya, Y., Hayward, S.D., Moran, T.H., Montell, C, Ross, C.A., et al. (2005). p53 mediates cellular dysfunction and behavioral abnormalities in Huntington's disease. Neuron 47,29-41.
Batista, L.F., Pech, M.F., Zhong, F.L., Nguyen, H.N., Xie, K.T., Zaug, A.J., Crary, S.M., Choi, J., Sebastiano, V., Cherry, A., et al. (2011). Telomere shortening and loss of self-renewal in dyskeratosis congenita induced pluripotent stem cells. Nature 474,399-402.
Ben-Shushan, E., Sharir, H., Pikarsky, E., and Bergman, Y. (1995). A dynamic balance between ARP-1/COUP-TFII, EAR-3/COUP-TFI, and retinoic acid receptonretinoid X receptor heterodimers regulates Oct-3/4 expression in embryonal carcinoma cells. Mol Cell Biol 15,1034-1048.
Bernstein, B.E., Mikkelsen, T.S., Xie, X., Kamal, M., Huebert, D.J., Cuff, J., Fry, B., Meissner, A., Wernig, M., Plath, K., et al. (2006). A bivalent chromatin structure marks key developmental genes in embryonic stem cells. Cell 125,315-326.
Birket, M.J., Orr, A.L., Gerencser, A.A., Madden, D.T., Vitelli, C., Swistowski, A., Brand, M.D., and Zeng, X. (2011). A reduction in ATP demand and mitochondrial activity with neural differentiation of human embryonic stem cells. J Cell Sci 124,348-358.
Blackburn, E.H. (2001). Switching and signaling at the telomere. Cell 106,661-673.
Blasco, M.A. (2005). Telomeres and human disease:ageing, cancer and beyond. Nat Rev Genet 6, 611-622.
Blasco, M.A., Lee, H.W., Hande, M.P., Samper, E., Lansdorp, P.M., DePinho, R.A., and Greider, C.W. (1997). Telomere shortening and tumor formation by mouse cells lacking telomerase RNA. Cell 91, 25-34.
Boyer, L.A., Lee, T.I., Cole, M.F., Johnstone, S.E., Levine, S.S., Zucker, J.P., Guenther, M.G., Kumar, R.M., Murray, H.L., Jenner, R.G., et al. (2005). Core transcriptional regulatory circuitry in human embryonic stem cells. Cell 122,947-956.
Boyer, L.A., Plath, K., Zeitlinger, J., Brambrink, T., Medeiros, L.A., Lee, T.I., Levine, S.S., Wernig, M., Tajonar, A., Ray, M.K., et al. (2006). Polycomb complexes repress developmental regulators in murine embryonic stem cells. Nature 441,349-353.
Buehr, M., Meek, S., Blair, K., Yang, J., Ure, J., Silva, J., McLay, R., Hall, J., Ying, Q.L., and Smith, A. (2008). Capture of authentic embryonic stem cells from rat blastocysts. Cell 135,1287-1298.
Byrne, J.A., Pedersen, D.A., Clepper, L.L., Nelson, M., Sanger, W.G., Gokhale, S., Wolf, D.P., and Mitalipov, S.M. (2007). Producing primate embryonic stem cells by somatic cell nuclear transfer. Nature 450,497-502.
Chambers, I., Colby, D., Robertson, M., Nichols, J., Lee, S., Tweedie, S., and Smith, A. (2003). Functional expression cloning of Nanog, a pluripotency sustaining factor in embryonic stem cells. Cell 113, 643-655.
Chambers, I., and Smith, A. (2004). Self-renewal of teratocarcinoma and embryonic stem cells. Oncogene 25,7150-7160.
Chin, M.H., Mason, M.J., Xie, W., Volinia, S., Singer, M., Peterson, C., Ambartsumyan, G., Aimiuwu, O., Richter, L., Zhang, J., et al. (2009). Induced pluripotent stem cells and embryonic stem cells are distinguished by gene expression signatures. Cell Stem Cell 5,111-123.
Chung, S., Dzeja, P.P., Faustino, R.S., Perez-Terzic, C., Behfar, A., and Terzic, A. (2007). Mitochondrial oxidative metabolism is required for the cardiac differentiation of stem cells. Nat Clin Pract Cardiovasc Med 4 Suppl I, S60-67.
Clark, A.J., Ferrier, P., Aslam, S., Burl, S., Denning, C., Wylie, D., Ross, A., de Sousa, P., Wilmut, I., and Cui, W. (2003). Proliferative lifespan is conserved after nuclear transfer. Nat Cell Biol 5,535-538.
Collins, K., and Mitchell, J.R. (2002). Telomerase in the human organism. Oncogene 21,564-579.
Costa, V., and Scorrano, L. (2012). Shaping the role of mitochondria in the pathogenesis of Huntington's disease. EMBO J 31,1853-1864.
Davis, R.L., Weintraub, H., and Lassar, A.B. (1987). Expression of a single transfected cDNA converts fibroblasts to myoblasts. Cell 51,987-1000.
de Lange, T. (2002). Protection of mammalian telomeres. Oncogene 21,532-540.
DeBerardinis, R.J., Lum, J.J., Hatzivassiliou, G., and Thompson, C.B. (2008). The biology of cancer: metabolic reprogramming fuels cell growth and proliferation. Cell Metab 7,11-20.
Donald, S.P., Sun, X.Y., Hu, C.A., Yu, J., Mei, J.M., Valle, D., and Phang, J.M. (2001). Proline oxidase, encoded by p53-induced gene-6, catalyzes the generation of proline-dependent reactive oxygen species. Cancer Res 61,1810-1815.
Dunham, M.A., Neumann, A.A., Fasching, C.L., and Reddel, R.R. (2000). Telomere maintenance by recombination in human cells. Nat Genet 26,447-450.
Egli, D., Rosains, J., Birkhoff, G., and Eggan, K. (2007). Developmental reprogramming after chromosome transfer into mitotic mouse zygotes. Nature 447,679-685.
Epel, E.S., Blackburn, E.H., Lin, J., Dhabhar, F.S., Adler, N.E., Morrow, J.D., and Cawthon, R.M. (2004). Accelerated telomere shortening in response to life stress. Proc Natl Acad Sci U S A 101, 17312-17315.
Epel, E.S., Lin, J., Wilhelm, F.H., Wolkowitz, O.M., Cawthon, R., Adler, N.E., Dolbier, C., Mendes, W.B., and Blackburn, E.H. (2006). Cell aging in relation to stress arousal and cardiovascular disease risk factors. Psychoneuroendocrinology 31,277-287.
Evans, M.J., and Kaufman, M.H. (1981). Establishment in culture of pluripotential cells from mouse embryos. Nature 292,154-156.
Exner, N., Lutz, A.K., Haass, C., and Winklhofer, K.F. (2012). Mitochondrial dysfunction in Parkinson's disease:molecular mechanisms and pathophysiological consequences. EMBO J 31,3038-3062.
Facucho-Oliveira, J.M., and St John, J.C. (2009). The relationship between pluripotency and mitochondrial DNA proliferation during early embryo development and embryonic stem cell differentiation. Stem Cell Rev 5,140-158.
Falco, G., Lee, S.L., Stanghellini, I., Bassey, U.C., Hamatani, T., and Ko, M.S. (2007). Zscan4:a novel gene expressed exclusively in late 2-cell embryos and embryonic stem cells. Dev Biol 307,539-550.
Fan, L., Crodian, J., Liu, X., Alestrom, A., Alestrom, P., and Collodi, P. (2004). Zebrafish embryo cells remain pluripotent and germ-line competent for multiple passages in culture. Zebrafish 1,21-26.
Feldman, N., Gerson, A., Fang, J., Li, E., Zhang, Y., Shinkai, Y., Cedar, H., and Bergman, Y. (2006). G9a-mediated irreversible epigenetic inactivation of Oct-3/4 during early embryogenesis. Nat Cell Biol 8,188-194.
Folmes, C.D., Dzeja, P.P., Nelson, T.J., and Terzic, A. (2012). Metabolic plasticity in stem cell homeostasis and differentiation. Cell Stem Cell 11,596-606.
Folmes, C.D., Nelson, T.J., Martinez-Fernandez, A., Arrell, D.K., Lindor, J.Z., Dzeja, P.P., Ikeda, Y., Perez-Terzic, C., and Terzic, A. (2011). Somatic oxidative bioenergetics transitions into pluripotency-dependent glycolysis to facilitate nuclear reprogramming. Cell Metab 14,264-271.
Garcia-Cao, M., O'Sullivan, R., Peters, A.H., Jenuwein, T., and Blasco, M.A. (2004). Epigenetic regulation of telomere length in mammalian cells by the Suv39h1 and Suv39h2 histone methyltransferases. Nat Genet 36,94-99.
Gehring, W.J. (1996). The master control gene for morphogenesis and evolution of the eye. Genes Cells 7, 11-15.
Gonzalo, S., Garcia-Cao, M., Fraga, M.F., Schotta, G., Peters, A.H., Cotter, S.E., Eguia, R., Dean, D.C., Esteller, M., Jenuwein, T., et al. (2005). Role of the RBI family in stabilizing histone methylation at constitutive heterochromatin. Nat Cell Biol 7,420-428.
Greider, C.W., and Blackburn, E.H. (1989). A telomeric sequence in the RNA of Tetrahymena telomerase required for telomere repeat synthesis. Nature 337,331-337.
Gu, P., Le Menuet, D., Chung, A.C., and Cooney, A.J. (2006). Differential recruitment of methylated CpG binding domains by the orphan receptor GCNF initiates the repression and silencing of Oct4 expression. Mol Cell Biol 26,9471-9483.
Gu, P., LeMenuet, D., Chung, A.C., Mancini, M., Wheeler, D.A., and Cooney, A.J. (2005). Orphan nuclear receptor GCNF is required for the repression of pluripotency genes during retinoic acid-induced embryonic stem cell differentiation. Mol Cell Biol 25,8507-8519.
Hanna, J., Wernig, M., Markoulaki, S., Sun, C.W., Meissner, A., Cassady, J.P., Beard, C., Brambrink, T., Wu, L.C., Townes, T.M., et al. (2007). Treatment of sickle cell anemia mouse model with iPS cells generated from autologous skin. Science 318,1920-1923.
Harley, C.B., Futcher, A.B., and Greider, C.W. (1990). Telomeres shorten during ageing of human fibroblasts. Nature 345,458-460.
Hayflick, L., and Moorhead, P.S. (1961). The serial cultivation of human diploid cell strains. Exp Cell Res 25,585-621.
Herrera, E., Samper, E., and Blasco, M.A. (1999a). Telomere shortening in mTR-/- embryos is associated with failure to close the neural tube. EMBO J 18,1172-1181.
Herrera, E., Samper, E., Martin-Caballero, J., Flores, J.M., Lee, H.W., and.Blasco, M.A. (1999b). Disease states associated with telomerase deficiency appear earlier in mice with short telomeres. EMBO J 18, 2950-2960.
Hochedlinger, K., and Jaenisch, R. (2002). Monoclonal mice generated by nuclear transfer from mature B and T donor cells. Nature 415,1035-1038.
Hochedlinger, K., and Plath, K. (2009). Epigenetic reprogramming and induced pluripotency. Development 136,509-523.
Hong, H., Takahashi, K., Ichisaka, T., Aoi, T., Kanagawa, O., Nakagawa, M., Okita, K., and Yamanaka, S. (2009). Suppression of induced pluripotent stem cell generation by the p53-p21 pathway. Nature 460, 1132-1135.
Hu, J., Hwang, S.S., Liesa, M., Gan, B., Sahin, E., Jaskelioff, M., Ding, Z., Ying, H., Boutin, A.T., Zhang, H., et al. (2012). Antitelomerase therapy provokes ALT and mitochondrial adaptive mechanisms in cancer. Cell 148,651-663.
Huang, J., Wang, F., Okuka, M., Liu, N., Ji, G., Ye, X., Zuo, B., Li, M., Liang, P., Ge, W.W., et al. (2011). Association of telomere length with authentic pluripotency of ES/iPS cells. Cell Res 21,779-792.
Jaenisch, R., and Young, R. (2008). Stem cells, the molecular circuitry of pluripotency and nuclear reprogramming. Cell 132,567-582.
Johnson, M.T., Mahmood, S., and Patel, M.S. (2003). Intermediary metabolism and energetics during murine early embryogenesis. J Biol Chem 278,31457-31460.
Kawamura, T., Suzuki, J., Wang, Y.V., Menendez, S., Morera, L.B., Raya, A., Wahl, G.M., and Izpisua Belmonte, J.C. (2009). Linking the p53 tumour suppressor pathway to somatic cell reprogramming. Nature 460,1140-1144.
Lange, K., Holm, L., Vang Nielsen, K., Hahn, A., Hofmann, W., Kreipe, H., Schlegelberger, B., and Gohring, G. (2010). Telomere shortening and chromosomal instability in myelodysplastic syndromes. Genes Chromosomes Cancer 49,260-269.
Lanza, R.P., Cibelli, J.B., Blackwell, C., Cristofalo, V.J., Francis, M.K., Baerlocher, G.M., Mak, J., Schertzer, M., Chavez, E.A., Sawyer, N., et al. (2000). Extension of cell life-span and telomere length in animals cloned from senescent somatic cells. Science 288,665-669.
Lee, H.W., Blasco, M.A., Gottlieb, G.J., Homer, J.W.,2nd, Greider, C.W., and DePinho, R.A. (1998). Essential role of mouse telomerase in highly proliferative organs. Nature 392,569-574.
Lee, T.I., Jenner, R.G., Boyer, L.A., Guenther, M.G., Levine, S.S., Kumar, R.M., Chevalier, B., Johnstone, S.E., Cole, M.F., Isono, K., et al. (2006). Control of developmental regulators by Polycomb in human embryonic stem cells. Cell 125,301-313.
Li, H., Collado, M., Villasante, A., Strati, K., Ortega, S., Canamero, M., Blasco, M.A., and Serrano, M. (2009). The Ink4/Arf locus is a barrier for iPS cell reprogramming. Nature 460,1136-1139.
Liu, L., Bailey, S.M., Okuka, M., Munoz, P., Li, C., Zhou, L., Wu, C., Czerwiec, E., Sandler, L., Seyfang, A., et al. (2007). Telomere lengthening early in development. Nat Cell Biol P.,1436-1441.
Locasale, J.W., and Cantley, L.C. (2011). Metabolic flux and the regulation of mammalian cell growth. Cell Metab 14,443-451.
Maherali, N., Sridharan, R., Xie, W., Utikal, J., Eminli, S., Arnold, K., Stadtfeld, M., Yachechko, R., Tchieu, J., Jaenisch, R., et al. (2007). Directly reprogrammed fibroblasts show global epigenetic remodeling and widespread tissue contribution. Cell Stem Cell 1,55-70.
Mandal, S., Lindgren, A.G, Srivastava, A.S., Clark, A.T., and Banerjee, U. (2011). Mitochondrial function controls proliferation and early differentiation potential of embryonic stem cells. Stem Cells 29, 486-495.
Marion, R.M., Strati, K., Li, H., Murga, M., Blanco, R., Ortega, S., Fernandez-Capetillo, O., Serrano, M., and Blasco, M.A. (2009a). A p53-mediated DNA damage response limits reprogramming to ensure iPS cell genomic integrity. Nature 460,1149-1153.
Marion, R.M., Strati, K., Li, H., Tejera, A., Schoeftner, S., Ortega, S., Serrano, M., and Blasco, M.A. (2009b). Telomeres acquire embryonic stem cell characteristics in induced pluripotent stem cells. Cell Stem Cell 4,141-154.
Marrone, A., Stevens, D., Vulliamy, T., Dokal, I., and Mason, P.J. (2004). Heterozygous telomerase RNA mutations found in dyskeratosis congenita and aplastic anemia reduce telomerase activity via haploinsufficiency. Blood 104,3936-3942.
Martin, G.M. (2005). Genetic modulation of senescent phenotypes in Homo sapiens. Cell 120,523-532.
Martin, G.R. (1981). Isolation of a pluripotent cell line from early mouse embryos cultured in medium conditioned by teratocarcinoma stem cells. Proc Natl Acad Sci U S A 78,7634-7638.
Matoba, S., Kang, J.G., Patino, W.D., Wragg, A., Boehm, M., Gavrilova,O., Hurley, P.J., Bunz, F., and Hwang, P.M. (2006). p53 regulates mitochondrial respiration. Science 312,1650-1653.
Meissner, A., Wernig, M., and Jaenisch, R. (2007). Direct reprogramming of genetically unmodified fibroblasts into pluripotent stem cells. Nat Biotechnol 25,1177-1181.
Mitchell, J.R., Wood, E., and Collins, K. (1999). A telomerase component is defective in the human disease dyskeratosis congenita. Nature 402,551-555.
Mitsui, K., Tokuzawa, Y., Itoh, H., Segawa, K., Murakami, M., Takahashi, K., Maruyama, M., Maeda, M., and Yamanaka, S. (2003). The homeoprotein Nanog is required for maintenance of pluripotency in mouse epiblast and ES cells. Cell 113,631-642.
Mizutani, E., Ono, T., Li, C., Maki-Suetsugu, R., and Wakayama, T. (2008). Propagation of senescent mice using nuclear transfer embryonic stem cell lines. Genesis 46,478-483.
Nichols, J., Zevnik, B., Anastassiadis, K., Niwa, H., Klewe-Nebenius, D., Chambers, I., Scholer, H., and Smith, A. (1998). Formation of pluripotent stem cells in the mammalian embryo depends on the POU transcription factor Oct4. Cell 95,379-391.
O'Sullivan, J.N., Bronner, M.P., Brentnall, T.A., Finley, J.C., Shen, W.T., Emerson, S., Emond, M.J., Gollahon, K.A., Moskovitz, A.H., Crispin, D.A., et al. (2002). Chromosomal instability in ulcerative colitis is related to telomere shortening. Nat Genet 32,280-284.
Odom, D.T., Dowell, R.D., Jacobsen, E.S., Nekludova, L., Rolfe, P.A., Danford, T.W., Gifford, D.K., Fraenkel, E., Bell, G.I., and Young, R.A. (2006). Core transcriptional regulatory circuitry in human hepatocytes. Mol Syst Biol 2,2006 0017.
Oh, H., Wang, S.C., Prahash, A., Sano, M., Moravec, C.S., Taffet, G.E., Michael, L.H., Youker, K.A., Entman, M.L., and Schneider, M.D. (2003). Telomere attrition and Chk2 activation in human heart failure. Proc Natl Acad Sci U S A 700,5378-5383.
Okamoto, K., Okazawa, H., Okuda, A., Sakai, M., Muramatsu, M., and Hamada, H. (1990). A novel octamer binding transcription factor is differentially expressed in mouse embryonic cells. Cell 60, 461-472.
Okita, K., Ichisaka, T., and Yamanaka, S. (2007). Generation of germline-competent induced pluripotent stem cells. Nature 448,313-317.
Okita, K., and Yamanaka, S. (2006). Intracellular signaling pathways regulating pluripotency of embryonic stem cells. Curr Stem Cell Res Ther 1,103-111.
Panopoulos, A.D., Yanes, O., Ruiz, S., Kida, Y.S., Diep, D., Tautenhahn, R., Herrerias, A., Batchelder, E.M., Plongthongkum, N., Lutz, M., et al. (2012). The metabolome of induced pluripotent stem cells reveals metabolic changes occurring in somatic cell reprogramming. Cell Res 22,168-177.
Park, I.H., Zhao, R., West, J.A., Yabuuchi, A., Huo, H., Ince, T.A., Lerou, P.H., Lensch, M.W., and Daley, G.Q. (2008). Reprogramming of human somatic cells to pluripotency with defined factors. Nature 451, 141-146.
Prigione, A., Fauler, B., Lurz, R., Lehrach, H., and Adjaye, J. (2010). The senescence-related mitochondrial/oxidative stress pathway is repressed in human induced pluripotent stem cells. Stem Cells 28,721-733.
Ranganathan, V., Heine, W.F., Ciccone, D.N., Rudolph, K.L., Wu, X., Chang, S., Hai, H., Ahearn, I.M., Livingston, D.M., Resnick, I., et al. (2001). Rescue of a telomere length defect of Nijmegen breakage syndrome cells requires NBS and telomerase catalytic subunit. Curr Biol 11,962-966.
Rideout, W.M.,3rd, Hochedlinger, K., Kyba, M., Daley, G.Q., and Jaenisch, R. (2002). Correction of a genetic defect by nuclear transplantation and combined cell and gene therapy. Cell 109,17-27.
Rudolph, K.L., Chang, S., Lee, H.W., Blasco, M., Gottlieb, G.J., Greider, C, and DePinho, R.A. (1999). Longevity, stress response, and cancer in aging telomerase-deficient mice. Cell 96,701-712.
Sahin, E., Colla, S., Liesa, M., Moslehi, J., Muller, F.L., Guo, M., Cooper, M., Kotton, D., Fabian, A.J., Walkey, C., et al. (2011). Telomere dysfunction induces metabolic and mitochondrial compromise. Nature 470,359-365.
Sahin, E., and Depinho, R.A. (2010). Linking functional decline of telomeres, mitochondria and stem cells during ageing. Nature 464,520-528.
Samani, N.J., Boultby, R., Butler, R., Thompson, J.R., and Goodall, A.H. (2001). Telomere shortening in atherosclerosis. Lancet 358,472-473.
Samper, E., Flores, J.M., and Blasco, M.A. (2001). Restoration of telomerase activity rescues chromosomal instability and premature aging in Terc-/- mice with short telomeres. EMBO Rep 2,800-807.
Samudio, I., Fiegl, M., and Andreeff, M. (2009). Mitochondrial uncoupling and the Warburg effect: molecular basis for the reprogramming of cancer cell metabolism. Cancer Res 69,2163-2166.
Sancho-Martinez, I., and Izpisua Belmonte, J.C. (2013). Will SCNT-ESCs be better than iPSCs for personalized regenerative medicine? Cell Stem Cell 13,141-142.
Saretzki, G., Walter, T., Atkinson, S., Passos, J.F., Bareth, B., Keith, W.N., Stewart, R., Hoare, S., Stojkovic, M., Armstrong, L., et al. (2008). Downregulation of multiple stress defense mechanisms during differentiation of human embryonic stem cells. Stem Cells 26,455-464.
Schaetzlein, S., Lucas-Hahn, A., Lemme, E., Kues, W.A., Dorsch, M., Manns, M.P., Niemann, H., and Rudolph, K.L. (2004). Telomere length is reset during early mammalian embryogenesis. Proc Natl Acad Sci U S A 101,8034-8038.
Schneuwly, S., Klemenz, R., and Gehring, W.J. (1987). Redesigning the body plan of Drosophila by ectopic expression of the homoeotic gene Antennapedia. Nature 325,816-818.
Shen, J., Liu, X., Yu, W.M., Liu, J., Nibbelink, M.G., Guo, C, Finkel, T., and Qu, C.K. (2011). A critical role of mitochondrial phosphatase Ptpmtl in embryogenesis reveals a mitochondrial metabolic stress-induced differentiation checkpoint in embryonic stem cells. Mol Cell Biol 31,4902-4916.
Shiels, P.G., Kind, A.J., Campbell, K.H., Waddington, D., Wilmut, I., Colman, A., and Schnieke, A.E. (1999). Analysis of telomere lengths in cloned sheep. Nature 399,316-317.
Shoubridge, E.A., and Wai, T. (2008). Medicine. Sidestepping mutational meltdown. Science 319,914-915.
Shyh-Chang, N., Zheng, Y., Locasale, J.W., and Cantley, L.C. (2011). Human pluripotent stem cells decouple respiration from energy production. EMBO J 30,4851-4852.
Simon, N.M., Smoller, J.W., McNamara, K.L., Maser, R.S., Zalta, A.K., Pollack, M.H., Nierenberg, A.A.. Fava, M., and Wong, K.K. (2006). Telomere shortening and mood disorders:preliminary support for a chronic stress model of accelerated aging. Biol Psychiatry 60,432-435.
Smith, A.G., Heath, J.K., Donaldson, D.D., Wong, G.G., Moreau, J., Stahl, M., and Rogers, D. (1988). Inhibition of pluripotential embryonic stem cell differentiation by purified polypeptides. Nature 336, 688-690.
Smogorzewska, A., and de Lange, T. (2004). Regulation of telomerase by telomeric proteins. Annu Rev Biochem 73,177-208.
Sperka, T., Song, Z., Morita, Y., Nalapareddy, K., Guachalla, L.M., Lechel, A., Begus-Nahrmann, Y., Burkhalter, M.D., Mach, M., Schlaudraff, F., et al. (2012). Puma and p21 represent cooperating checkpoints limiting self-renewal and chromosomal instability of somatic stem cells in response to telomere dysfunction. Nat Cell Biol 14,73-79.
Stock, J.K., Giadrossi, S., Casanova, M., Brookes, E., Vidal, M., Koseki, H., Brockdorff, N., Fisher, A.G., and Pombo, A. (2007). Ring 1-mediated ubiquitination of H2A restrains poised RNA polymerase II at bivalent genes in mouse ES cells. Nat Cell Biol 9,1428-1435.
Tachibana, M., Amato, P., Sparman, M., Gutierrez, N.M., Tippner-Hedges, R., Ma, H., Kang, E., Fulati, A., Lee, H.S., Sritanaudomchai, H., et al. (2013). Human embryonic stem cells derived by somatic cell nuclear transfer. Cell 153,1228-1238.
Tahara, H., Tokutake, Y., Maeda, S., Kataoka, H., Watanabe, T., Satoh, M., Matsumoto, T., Sugawara, M., Ide, T., Goto, M., et al. (1997). Abnormal telomere dynamics of B-Iymphoblastoid cell strains from Werner's syndrome patients transformed by Epstein-Barr virus. Oncogene 15,1911-1920.
Takahashi, K., Tanabe, K., Ohnuki, M., Narita, M., Ichisaka, T., Tomoda, K., and Yamanaka, S. (2007). Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell 131, 861-872.
Takahashi, K., and Yamanaka, S. (2006). Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors. Cell 126,663-676.
Taylor, A.M., Groom, A., and Byrd, P.J. (2004). Ataxia-telangiectasia-like disorder (ATLD)-its clinical presentation and molecular basis. DNA Repair (Amst) 3,1219-1225.
Tchirkov, A., and Lansdorp, P.M. (2003). Role of oxidative stress in telomere shortening in cultured fibroblasts from normal individuals and patients with ataxia-telangiectasia. Hum Mol Genet 12, 227-232.
Thomson, J.A., Itskovitz-Eldor, J., Shapiro, S.S., Waknitz, M.A., Swiergiel, J.J., Marshall, V.S., and Jones, J.M. (1998). Embryonic stem cell lines derived from human blastocysts. Science 282,1145-1147.
Thomson, J.A., Kalishman, J., Golos, T.G., Durning, M., Harris, C.P., Becker, R.A., and Hearn, J.P. (1995). Isolation of a primate embryonic stem cell line. Proc Natl Acad Sci U S A 92,7844-7848.
Thomson, J.A., Kalishman, J., Golos, T.G., Durning, M., Harris, C.P., and Hearn, J.P. (1996). Pluripotent cell lines derived from common marmoset (Callithrix jacchus) blastocysts. Biol Reprod 55,254-259.
Thuan, N.V., Kishigami, S., and Wakayama, T. (2010). How to improve the success rate of mouse cloning technology. J Reprod Dev 56,20-30.
Tian, X.C., Xu, J., and Yang, X. (2000). Normal telomere lengths found in cloned cattle. Nat Genet 26, 272-273.
Utikal, J., Polo, J.M., Stadtfeld, M., Maherali, N., Kulalert, W., Walsh, R.M., Khalil, A., Rheinwald, J.G., and Hochedlinger, K. (2009). Immortalization eliminates a roadblock during cellular reprogramming into iPS cells. Nature 460,1145-1148.
Van Blerkom, J. (2009). Mitochondria in early mammalian development. Semin Cell Dev Biol 20, 354-364.
Vaziri, H., Chapman, K.B., Guigova, A., Teichroeb, J., Lacher, M.D., Sternberg, H., Singec, I., Briggs, L. Wheeler, J., Sampathkumar, J., et al. (2010). Spontaneous reversal of the developmental aging of normal human cells following transcriptional reprogramming. Regen Med 5,345-363.
Vulliamy, T., Marrone, A., Goldman, F., Dearlove, A., Bessler, M., Mason, P.J., and Dokal, I. (2001). The RNA component of telomerase is mutated in autosomal dominant dyskeratosis congenita. Nature 413, 432-435.
Vulliamy, T., Marrone, A., Szydlo, R., Walne, A., Mason, P.J., and Dokal, I. (2004). Disease anticipation is associated with progressive telomere shortening in families with dyskeratosis congenita due to mutations in TERC. Nat Genet 36,447-449.
Wakayama, S., Ohta, H., Hikichi, T., Mizutani, E., Iwaki, T., Kanagawa,O., and Wakayama, T. (2008). Production of healthy cloned mice from bodies frozen at-20 degrees for 16 years. Proc Natl Acad Sci USA 105,17318-17322.
Wakayama, T., Perry, A.C., Zuccotti, M., Johnson, K.R., and Yanagimachi, R. (1998). Full-term development of mice from enucleated oocytes injected with cumulus cell nuclei. Nature 394,369-374.
Wakayama, T., Shinkai, Y., Tamashiro, K.L., Niida, H., Blanchard, D.C., Blanchard, R.J., Ogura, A., Tanemura, K., Tachibana, M., Perry, A.C., et al. (2000). Cloning of mice to six generations. Nature 407,318-319.
Wang, F., Yin, Y., Ye, X., Liu, K., Zhu, H., Wang, L., Chiourea, M., Okuka, M., Ji, G, Dan, J., et al. (2012). Molecular insights into the heterogeneity of telomere reprogramming in induced pluripotent stem cells. Cell Res 22,757-768.
Wang, Y., Erdmann, N., Giannone, R.J., Wu, J., Gomez, M., and Liu, Y. (2005). An increase in telomere sister chromatid exchange in murine embryonic stem cells possessing critically shortened telomeres. Proc Natl Acad Sci U S A 102,10256-10260.
Wernig, M., Meissner, A., Cassady, J.P., and Jaenisch, R. (2008). c-Myc is dispensable for direct reprogramming of mouse fibroblasts. Cell Stem Cell 2,10-12.
Wernig, M., Meissner, A., Foreman, R., Brambrink, T., Ku, M., Hochedlinger, K., Bernstein, B.E., and Jaenisch, R. (2007). In vitro reprogramming of fibroblasts into a pluripotent ES-cell-like state. Nature 448,318-324.
Wick, G., and Grubeck-Loebenstein, B. (1997). Primary and secondary alterations of immune reactivity in the elderly:impact of dietary factors and disease. Immunol Rev 160,171-184.
Wilmut, I., Schnieke, A.E., McWhir, J., Kind, A.J., and Campbell, K.H. (1997). Viable offspring derived from fetal and adult mammalian cells. Nature 385,810-813.
Wyllie, F.S., Jones, C.J., Skinner, J.W., Haughton, M.F., Wallis, C., Wynford-Thomas, D., Faragher, R.G., and Kipling, D. (2000). Telomerase prevents the accelerated cell ageing of Werner syndrome fibroblasts. Nat Genet 24,16-17.
Yamaguchi, H., Calado, R.T., Ly, H., Kajigaya, S., Baerlocher, G.M., Chanock, S.J., Lansdorp, P.M., and Young, N.S. (2005). Mutations in TERT, the gene for telomerase reverse transcriptase, in aplastic anemia. N Engl J Med 352,1413-1424.
Yamanaka, S., and Blau, H.M. (2010). Nuclear reprogramming to a pluripotent state by three approaches. Nature 465,704-712.
Yang, C., Przyborski, S., Cooke, M.J., Zhang, X., Stewart, R., Anyfantis, G., Atkinson, S.P., Saretzki, G., Armstrong, L., and Lako, M. (2008). A key role for telomerase reverse transcriptase unit in modulating human embryonic stem cell proliferation, cell cycle dynamics, and in vitro differentiation. Stem Cells 26,850-863.
Yu, G.L., Bradley, J.D., Attardi, L.D., and Blackburn, E.H. (1990). In vivo alteration of telomere sequences and senescence caused by mutated Tetrahymena telomerase RNAs. Nature 344,126-132.
Yu, J., Vodyanik, M.A., Smuga-Otto, K., Antosiewicz-Bourget, J., Frane, J.L., Tian, S., Nie, J., Jonsdottir, G.A., Ruotti, V., Stewart, R., et al. (2007). Induced pluripotent stem cell lines derived from human somatic cells. Science 318,1917-1920.
Zalzman, M., Falco, G., Sharova, L.V., Nishiyama, A., Thomas, M., Lee, S.L., Stagg, C.A., Hoang, H.G., Yang, H.T., Indig, F.E., et al. (2010). Zscan4 regulates telomere elongation and genomic stability in ES cells. Nature 464,858-863.
Zhang, J., Khvorostov, I., Hong, J.S., Oktay, Y., Vergnes, L., Nuebel, E., Wahjudi, P.N., Setoguchi, K., Wang, G., Do, A., et al. (2011). UCP2 regulates energy metabolism and differentiation potential of human pluripotent stem cells. EMBO J 30,4860-4873.
Zhang, J., Nuebel, E., Daley, G.Q., Koehler, C.M., and Teitell, M.A. (2012). Metabolic Regulation in Pluripotent Stem Cells during Reprogramming and Self-Renewal. Cell Stem Cell 11,589-595.
Zhu, H., Shyh-Chang, N., Segre, A.V., Shinoda, G., Shah, S.P., Einhorn, W.S., Takeuchi, A., Engreitz, J.M., Hagan, J.P., Kharas, M.G., et al. (2011). The Lin28/let-7 axis regulates glucose metabolism. Cell 147, 81-94.
