Talk:Embryology History - Shinya Yamanaka
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Cite this page: Hill, M.A. (2019, December 12) Embryology Embryology History - Shinya Yamanaka. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Embryology_History_-_Shinya_Yamanaka
Generation of Naive-like Porcine Induced Pluripotent Stem Cells Capable of Contributing to Embryonic and Fetal Development
Stem Cells Dev. 2012 Aug 13. [
Fujishiro SH, Nakano K, Mizukami Y, Azami T, Arai Y, Matsunari H, Ishino R, Nishimura T, Watanabe M, Abe T, Furukawa Y, Umeyama K, Yamanaka S, Ema M, Nagashima H, Hanazono Y.
In pluripotent stem cells (PSCs), there are two types: naive and primed. Only the naive type has the capacity for producing chimeric offspring. Mouse PSCs are naive, but human PSCs are in the primed state. Previously reported porcine PSCs appear in the primed state. In this study, putative naive porcine induced pluripotent stem cells (iPSCs) were generated. Porcine embryonic fibroblasts were transduced with retroviral vectors expressing Yamanaka's four genes. Emergent colonies were propagated in the presence of porcine leukemia inhibitory factor (pLIF) and forskolin. The cells expressed pluripotency markers, and formed embryoid bodies which gave rise to cell types from all 3 embryonic germ layers. The naive state of the cells was demonstrated by pLIF-dependency, two active X chromosomes (when female), absent MHC class I expression, and characteristic gene expression profiles. The porcine iPSCs contributed to the in vitro embryonic development (11/24, 45.8%). They also contributed to the in utero fetal development (11/71, 15.5% at day 23; 1/13, 7.7% at day 65). This is the first demonstration of macroscopic, fluorescent chimeras derived from naive-like porcine PSCs, although adult chimeras remain to be produced.
Donor-dependent variations in hepatic differentiation from human-induced pluripotent stem cells
Proc Natl Acad Sci U S A. 2012 Jul 31;109(31):12538-43. Epub 2012 Jul 16.
Kajiwara M, Aoi T, Okita K, Takahashi R, Inoue H, Takayama N, Endo H, Eto K, Toguchida J, Uemoto S, Yamanaka S. Source Center for Induced Pluripotent Stem Cell Research and Application, Department of Surgery, Graduate School of Medicine, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
Hepatocytes generated from human induced pluripotent stem cells (hiPSCs) are unprecedented resources for pharmaceuticals and cell therapy. However, the in vitro directed differentiation of human pluripotent stem cells into mature hepatocytes remains challenging. Little attention has so far been paid to variations among hiPSC lines in terms of their hepatic differentiation. In the current study, we developed an improved hepatic differentiation protocol and compared 28 hiPSC lines originated from various somatic cells and derived using retroviruses, Sendai viruses, or episomal plasmids. This comparison indicated that the origins, but not the derivation methods, may be a major determinant of variation in hepatic differentiation. The hiPSC clones derived from peripheral blood cells consistently showed good differentiation efficiency, whereas many hiPSC clones from adult dermal fibroblasts showed poor differentiation. However, when we compared hiPSCs from peripheral blood and dermal fibroblasts from the same individuals, we found that variations in hepatic differentiation were largely attributable to donor differences, rather than to the types of the original cells. These data underscore the importance of donor differences when comparing the differentiation propensities of hiPSC clones.
Induced pluripotent stem cells: past, present, and future
Cell Stem Cell. 2012 Jun 14;10(6):678-84.
Center for iPS Cell Research and Application, Kyoto University, Kyoto 606-8507, Japan. email@example.com
The development of iPSCs reflected the merging of three major scientific streams and has in turn led to additional new branches of investigation. However, there is still debate about whether iPSCs are functionally equivalent to ESCs. This question should be answered only by science, not by politics or business. Copyright © 2012 Elsevier Inc. All rights reserved.
Human induced pluripotent stem cells on autologous feeders
PLoS One. 2009 Dec 2;4(12):e8067.
Takahashi K, Narita M, Yokura M, Ichisaka T, Yamanaka S. Source Center for iPS cell Research and Application, Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, Japan. firstname.lastname@example.org
BACKGROUND: For therapeutic usage of induced Pluripotent Stem (iPS) cells, to accomplish xeno-free culture is critical. Previous reports have shown that human embryonic stem (ES) cells can be maintained in feeder-free condition. However, absence of feeder cells can be a hostile environment for pluripotent cells and often results in karyotype abnormalities. Instead of animal feeders, human fibroblasts can be used as feeder cells of human ES cells. However, one still has to be concerned about the existence of unidentified pathogens, such as viruses and prions in these non-autologous feeders. METHODOLOGY/PRINCIPAL FINDINGS: This report demonstrates that human induced Pluripotent Stem (iPS) cells can be established and maintained on isogenic parental feeder cells. We tested four independent human skin fibroblasts for the potential to maintain self-renewal of iPS cells. All the fibroblasts tested, as well as their conditioned medium, were capable of maintaining the undifferentiated state and normal karyotypes of iPS cells. Furthermore, human iPS cells can be generated on isogenic parental fibroblasts as feeders. These iPS cells carried on proliferation over 19 passages with undifferentiated morphologies. They expressed undifferentiated pluripotent cell markers, and could differentiate into all three germ layers via embryoid body and teratoma formation. CONCLUSIONS/SIGNIFICANCE: These results suggest that autologous fibroblasts can be not only a source for iPS cells but also be feeder layers. Our results provide a possibility to solve the dilemma by using isogenic fibroblasts as feeder layers of iPS cells. This is an important step toward the establishment of clinical grade iPS cells.
Nanog is the gateway to the pluripotent ground state
Cell. 2009 Aug 21;138(4):722-37.
Silva J, Nichols J, Theunissen TW, Guo G, van Oosten AL, Barrandon O, Wray J, Yamanaka S, Chambers I, Smith A. Source Wellcome Trust Centre for Stem Cell Research, University of Cambridge, Cambridge CB2 1QR, UK. email@example.com
Pluripotency is generated naturally during mammalian development through formation of the epiblast, founder tissue of the embryo proper. Pluripotency can be recreated by somatic cell reprogramming. Here we present evidence that the homeodomain protein Nanog mediates acquisition of both embryonic and induced pluripotency. Production of pluripotent hybrids by cell fusion is promoted by and dependent on Nanog. In transcription factor-induced molecular reprogramming, Nanog is initially dispensable but becomes essential for dedifferentiated intermediates to transit to ground state pluripotency. In the embryo, Nanog specifically demarcates the nascent epiblast, coincident with the domain of X chromosome reprogramming. Without Nanog, pluripotency does not develop, and the inner cell mass is trapped in a pre-pluripotent, indeterminate state that is ultimately nonviable. These findings suggest that Nanog choreographs synthesis of the naive epiblast ground state in the embryo and that this function is recapitulated in the culmination of somatic cell reprogramming.
Science. 2008 Nov 7;322(5903):949-53. Epub 2008 Oct 9.
Okita K, Nakagawa M, Hyenjong H, Ichisaka T, Yamanaka S. Source Center for iPS Cell Research and Application (CiRA), Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507, Japan.
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.
Pluripotency and nuclear reprogramming
Philos Trans R Soc Lond B Biol Sci. 2008 Jun 27;363(1500):2079-87.
Yamanaka S. Source Center for iPS Cell Research & Application, Kyoto University, Kyoto 606-8507, Japan. firstname.lastname@example.org
Embryonic stem cells are promising donor cell sources for cell transplantation therapy, which may in the future be used to treat various diseases and injuries. However, as is the case for organ transplantation, immune rejection after transplantation is a potential problem with this type of therapy. Moreover, the use of human embryos presents serious ethical difficulties. These issues may be overcome if pluripotent stem cells are generated from patients' somatic cells. Here, we review the molecular mechanisms underlying pluripotency and the currently known methods of inducing pluripotency in somatic cells.
B-MYB is essential for normal cell cycle progression and chromosomal stability of embryonic stem cells
PLoS One. 2008 Jun 25;3(6):e2478.
Tarasov KV, Tarasova YS, Tam WL, Riordon DR, Elliott ST, Kania G, Li J, Yamanaka S, Crider DG, Testa G, Li RA, Lim B, Stewart CL, Liu Y, Van Eyk JE, Wersto RP, Wobus AM, Boheler KR. Source Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America.
BACKGROUND: The transcription factor B-Myb is present in all proliferating cells, and in mice engineered to remove this gene, embryos die in utero just after implantation due to inner cell mass defects. This lethal phenotype has generally been attributed to a proliferation defect in the cell cycle phase of G1. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we show that the major cell cycle defect in murine embryonic stem (mES) cells occurs in G2/M. Specifically, knockdown of B-Myb by short-hairpin RNAs results in delayed transit through G2/M, severe mitotic spindle and centrosome defects, and in polyploidy. Moreover, many euploid mES cells that are transiently deficient in B-Myb become aneuploid and can no longer be considered viable. Knockdown of B-Myb in mES cells also decreases Oct4 RNA and protein abundance, while over-expression of B-MYB modestly up-regulates pou5f1 gene expression. The coordinated changes in B-Myb and Oct4 expression are due, at least partly, to the ability of B-Myb to directly modulate pou5f1 gene promoter activity in vitro. Ultimately, the loss of B-Myb and associated loss of Oct4 lead to an increase in early markers of differentiation prior to the activation of caspase-mediated programmed cell death. CONCLUSIONS/SIGNIFICANCE: Appropriate B-Myb expression is critical to the maintenance of chromosomally stable and pluripotent ES cells, but its absence promotes chromosomal instability that results in either aneuploidy or differentiation-associated cell death.
Generation of pluripotent stem cells from adult mouse liver and stomach cells
Science. 2008 Aug 1;321(5889):699-702. Epub 2008 Feb 14.
Aoi T, Yae K, Nakagawa M, Ichisaka T, Okita K, Takahashi K, Chiba T, Yamanaka S. Source Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan. Erratum in Science.2008 Aug 1;321(5889): 641.
Induced pluripotent stem (iPS) cells have been generated from mouse and human fibroblasts by the retroviral transduction of four transcription factors. However, the cell origins and molecular mechanisms of iPS cell induction remain elusive. This report describes the generation of iPS cells from adult mouse hepatocytes and gastric epithelial cells. These iPS cell clones appear to be equivalent to embryonic stem cells in gene expression and are competent to generate germline chimeras. Genetic lineage tracings show that liver-derived iPS cells are derived from albumin-expressing cells. No common retroviral integration sites are found among multiple clones. These data suggest that iPS cells are generated by direct reprogramming of lineage-committed somatic cells and that retroviral integration into specific sites is not required.