1
|
Zhou M, Zhang M, Guo T, Zhao L, Guo X, Yin Z, Cheng L, Liu H, Zhao L, Li X, Li R. Species origin of exogenous transcription factors affects the activation of endogenous pluripotency markers and signaling pathways of porcine induced pluripotent stem cells. Front Cell Dev Biol 2023; 11:1196273. [PMID: 37152293 PMCID: PMC10160484 DOI: 10.3389/fcell.2023.1196273] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 04/12/2023] [Indexed: 05/09/2023] Open
Abstract
The incomplete silencing of exogenous transcription factors (TFs) and the lack of endogenous counterpart activation hampers the application of porcine induced pluripotent stem cells (piPSCs). We used porcine, bovine and murine TFs to reprogram porcine fetal fibroblasts. Porcine TFs-derived piPSCs (ppiPSCs) showed the highest levels of endogenous pluripotency markers activation, were able to differentiate into three germ layers and primordial germ cell-like cells (PGCLCs) and integrated into neural ectoderm of E7.5 mouse embryos in vitro. The bovine TFs derived piPSCs (bpiPSCs) expressed endogenous pluripotency markers higher than murine TFs derived piPSCs (mpiPSCs), but both had limited differentiation ability in vitro and depended on continuous expression of exogenous TFs for the maintenance. RNA sequencing confirmed ppiPSCs had distinct global transcriptional profiling, upregulated Hippo, PI3K-Akt, MAPK and relevant pluripotency signaling pathways as porcine blastocyst inner cell mass and expressed PGC early related genes. In addition, a positive and a negative correlation between exogenous and endogenous TFs' expression level were observed in ppiPSCs and bpiPSCs lines, respectively. The TFs' protein structures in pig were more similar to cattle than to mouse. In conclusion, the species affinity of the exogenous TFs is a key element, and the own species origin of TFs is optimal for iPSCs generation and application.
Collapse
Affiliation(s)
- Meng Zhou
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Manling Zhang
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Tianxu Guo
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Lihua Zhao
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, China
| | - Xiyun Guo
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Zhibao Yin
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Linxin Cheng
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Han Liu
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
| | - Lixia Zhao
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Xihe Li
- The State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Science, Inner Mongolia University, Hohhot, Inner Mongolia, China
| | - Rongfeng Li
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, China
- Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, China
- *Correspondence: Rongfeng Li,
| |
Collapse
|
2
|
Epithelial Cell Transformation and Senescence as Indicators of Genome Aging: Current Advances and Unanswered Questions. Int J Mol Sci 2021; 22:ijms22147544. [PMID: 34299168 PMCID: PMC8303760 DOI: 10.3390/ijms22147544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 02/06/2023] Open
Abstract
The recent advances in deciphering the human genome allow us to understand and evaluate the mechanisms of human genome age-associated transformations, which are largely unclear. Genome sequencing techniques assure comprehensive mapping of human genetics; however, understanding of gene functional interactions, specifically of time/age-dependent modifications, remain challenging. The age of the genome is defined by the sum of individual (inherited) and acquired genomic traits, based on internal and external factors that impact ontogenesis from the moment of egg fertilization and embryonic development. The biological part of genomic age opens a new perspective for intervention. The discovery of single cell-based mechanisms for genetic change indicates the possibility of influencing aging and associated disease burden, as well as metabolism. Cell populations with transformed genetic background were shown to serve as the origin of common diseases during extended life expectancy (superaging). Consequently, age-related cell transformation leads to cancer and cell degeneration (senescence). This article aims to describe current advances in the genomic mechanisms of senescence and its role in the spatiotemporal spread of epithelial clones and cell evolution.
Collapse
|
3
|
Giallongo S, Rehakova D, Raffaele M, Lo Re O, Koutna I, Vinciguerra M. Redox and Epigenetics in Human Pluripotent Stem Cells Differentiation. Antioxid Redox Signal 2021; 34:335-349. [PMID: 32567336 DOI: 10.1089/ars.2019.7983] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Significance: Since their discovery, induced pluripotent stem cells (iPSCs) had generated considerable interest in the scientific community for their great potential in regenerative medicine, disease modeling, and cell-based therapeutic approach, due to their unique characteristics of self-renewal and pluripotency. Recent Advances: Technological advances in iPSC genome-wide epigenetic profiling led to the elucidation of the epigenetic control of cellular identity during nuclear reprogramming. Moreover, iPSC physiology and metabolism are tightly regulated by oxidation-reduction events that mainly occur during the respiratory chain. In theory, iPSC-derived differentiated cells would be ideal for stem cell transplantation as autologous cells from donors, as the risks of rejection are minimal. Critical Issues: However, iPSCs experience high oxidative stress that, in turn, confers a high risk of increased genomic instability, which is most often linked to DNA repair deficiencies. Genomic instability has to be assessed before iPSCs can be used in therapeutic designs. Future Directions: This review will particularly focus on the links between redox balance and epigenetic modifications-in particular based on the histone variant macroH2A1-that determine DNA damage response in iPSCs and derived differentiated cells, and that might be exploited to decrease the teratogenic potential on iPSC transplantation. Antioxid. Redox Signal. 34, 335-349.
Collapse
Affiliation(s)
- Sebastiano Giallongo
- International Clinical Research Center, St' Anne's University Hospital, Brno, Czech Republic.,Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Daniela Rehakova
- International Clinical Research Center, St' Anne's University Hospital, Brno, Czech Republic.,Faculty of Informatics, Centre for Biomedical Image Analysis, Masaryk University, Brno, Czech Republic
| | - Marco Raffaele
- International Clinical Research Center, St' Anne's University Hospital, Brno, Czech Republic
| | - Oriana Lo Re
- International Clinical Research Center, St' Anne's University Hospital, Brno, Czech Republic
| | - Irena Koutna
- International Clinical Research Center, St' Anne's University Hospital, Brno, Czech Republic.,Faculty of Informatics, Centre for Biomedical Image Analysis, Masaryk University, Brno, Czech Republic
| | - Manlio Vinciguerra
- International Clinical Research Center, St' Anne's University Hospital, Brno, Czech Republic.,Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| |
Collapse
|
4
|
Scarfone RA, Pena SM, Russell KA, Betts DH, Koch TG. The use of induced pluripotent stem cells in domestic animals: a narrative review. BMC Vet Res 2020; 16:477. [PMID: 33292200 PMCID: PMC7722595 DOI: 10.1186/s12917-020-02696-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/24/2020] [Indexed: 02/07/2023] Open
Abstract
Induced pluripotent stem cells (iPSCs) are undifferentiated stem cells characterized by the ability to differentiate into any cell type in the body. iPSCs are a relatively new and rapidly developing technology in many fields of biology, including developmental anatomy and physiology, pathology, and toxicology. These cells have great potential in research as they are self-renewing and pluripotent with minimal ethical concerns. Protocols for their production have been developed for many domestic animal species, which have since been used to further our knowledge in the progression and treatment of diseases. This research is valuable both for veterinary medicine as well as for the prospect of translation to human medicine. Safety, cost, and feasibility are potential barriers for this technology that must be considered before widespread clinical adoption. This review will analyze the literature pertaining to iPSCs derived from various domestic species with a focus on iPSC production and characterization, applications for tissue and disease research, and applications for disease treatment.
Collapse
Affiliation(s)
- Rachel A Scarfone
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Samantha M Pena
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Keith A Russell
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - Dean H Betts
- Department of Physiology and Pharmacology, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | - Thomas G Koch
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada.
| |
Collapse
|
5
|
Cherdyntseva V, Gagos S. Chromosome extremities under the microscopy lens: molecular cytogenetics in telomere research. Curr Opin Genet Dev 2020; 60:69-76. [PMID: 32193147 DOI: 10.1016/j.gde.2020.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 02/03/2020] [Accepted: 02/06/2020] [Indexed: 02/07/2023]
Abstract
At the crossroads of DNA damage repair and genomic instability, telomere research significantly expands our knowledge on fundamental mechanisms involved in cancer initiation and progression, pledging novel tools for targeted and universal onco-therapies. Molecular cytogenetics through the application of a battery of fluorescent hybridization technologies plays an important role toward understanding telomere homeostasis. Herein, we review distinct molecular cytogenetic phenotypes associated with telomere repair, functionality, and elongation. We discuss the underlying mechanisms responsible for their formation or repair, focusing on Break-induced-Replication (BIR)-mediated conservative telomeric neo-synthesis, recently shown to drive the enigmatic Alternative Lengthening of Telomeres in neoplasia.
Collapse
Affiliation(s)
- Veronica Cherdyntseva
- Laboratory of Genetics, Center of Clinical Research, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, 11527, Greece
| | - Sarantis Gagos
- Laboratory of Genetics, Center of Clinical Research, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, 11527, Greece.
| |
Collapse
|
6
|
Pessôa LVDF, Bressan FF, Freude KK. Induced pluripotent stem cells throughout the animal kingdom: Availability and applications. World J Stem Cells 2019; 11:491-505. [PMID: 31523369 PMCID: PMC6716087 DOI: 10.4252/wjsc.v11.i8.491] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023] Open
Abstract
Up until the mid 2000s, the capacity to generate every cell of an organism was exclusive to embryonic stem cells. In 2006, researchers Takahashi and Yamanaka developed an alternative method of generating embryonic-like stem cells from adult cells, which they coined induced pluripotent stem cells (iPSCs). Such iPSCs possess most of the advantages of embryonic stem cells without the ethical stigma associated with derivation of the latter. The possibility of generating “custom-made” pluripotent cells, ideal for patient-specific disease models, alongside their possible applications in regenerative medicine and reproduction, has drawn a lot of attention to the field with numbers of iPSC studies published growing exponentially. IPSCs have now been generated for a wide variety of species, including but not limited to, mouse, human, primate, wild felines, bovines, equines, birds and rodents, some of which still lack well-established embryonic stem cell lines. The paucity of robust characterization of some of these iPSC lines as well as the residual expression of transgenes involved in the reprogramming process still hampers the use of such cells in species preservation or medical research, underscoring the requirement for further investigations. Here, we provide an extensive overview of iPSC generated from a broad range of animal species including their potential applications and limitations.
Collapse
Affiliation(s)
- Laís Vicari de Figueiredo Pessôa
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg 1870, Denmark
| | - Fabiana Fernandes Bressan
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga 13635-000, São Paulo, Brazil
| | - Kristine Karla Freude
- Group of Stem Cell Models for Studies of Neurodegenerative Diseases, Section for Pathobiological Sciences, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg 1870, Denmark
| |
Collapse
|
7
|
Donaires FS, Alves-Paiva RM, Gutierrez-Rodrigues F, da Silva FB, Tellechea MF, Moreira LF, Santana BA, Traina F, Dunbar CE, Winkler T, Calado RT. Telomere dynamics and hematopoietic differentiation of human DKC1-mutant induced pluripotent stem cells. Stem Cell Res 2019; 40:101540. [PMID: 31479877 DOI: 10.1016/j.scr.2019.101540] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 08/08/2019] [Accepted: 08/19/2019] [Indexed: 02/07/2023] Open
Abstract
Telomeropathies are a group of phenotypically heterogeneous diseases molecularly unified by pathogenic mutations in telomere-maintenance genes causing critically short telomeres. X-linked dyskeratosis congenita (DC), the prototypical telomere disease, manifested with ectodermal dysplasia, cancer predisposition, and severe bone marrow failure, is caused by mutations in DKC1, encoding a protein responsible for telomerase holoenzyme complex stability. To investigate the effects of pathogenic DKC1 mutations on telomere repair and hematopoietic development, we derived induced pluripotent stem cells (iPSCs) from fibroblasts of a DC patient carrying the most frequent mutation: DKC1 p.A353V. Telomeres eroded immediately after reprogramming in DKC1-mutant iPSCs but stabilized in later passages. The telomerase activity of mutant iPSCs was comparable to that observed in human embryonic stem cells, and no evidence of alternative lengthening of telomere pathways was detected. Hematopoietic differentiation was carried out in DKC1-mutant iPSC clones that resulted in increased capacity to generate hematopoietic colony-forming units compared to controls. Our study indicates that telomerase-dependent telomere maintenance is defective in pluripotent stem cells harboring DKC1 mutation and unable to elongate telomeres, but sufficient to maintain cell proliferation and self-renewal, as well as to support the primitive hematopoiesis, the program that is recapitulated with our differentiation protocol.
Collapse
Affiliation(s)
- Flavia S Donaires
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Raquel M Alves-Paiva
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Fernanda Gutierrez-Rodrigues
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Fernanda Borges da Silva
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Maria Florencia Tellechea
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Lilian Figueiredo Moreira
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Barbara A Santana
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Fabiola Traina
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Cynthia E Dunbar
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Thomas Winkler
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Rodrigo T Calado
- Department of Medical Imaging, Hematology, and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.
| |
Collapse
|
8
|
Fukuda T, Doi K, Donai K, Takahashi K, Kobayashi H, Hirano T, Nishimori K, Yasue H. Global transcriptome analysis of pig induced pluripotent stem cells derived from six and four reprogramming factors. Sci Data 2019; 6:190034. [PMID: 30806635 PMCID: PMC6390709 DOI: 10.1038/sdata.2019.34] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 01/17/2019] [Indexed: 12/17/2022] Open
Abstract
Pigs are important, both for agriculture and as animal models for human diseases. However, due to the lack of embryonic stem cells, the possibility of genetic modification is quite limited. To overcome this limitation, induced pluripotent stem (iPS) cells have been derived from pigs. Despite the public availability of a large number of expression datasets from mice, rats, and primates-derived iPS cells, the expression profile of pig-derived iPS cells is quite limited. Furthermore, there is no dataset focused on the profiling of pig-derived iPS cell with six reprogramming factors (Oct3/4, Sox2, Klf4, c-Myc, Lin28, and Nanog). Here, we used Illumina RNA sequencing platform to characterize the mRNA expression of four-factor derived and six-factor derived pig iPS cells. We observed that the expression levels of whole genes in our established six factors derived iPS cells and parent fibroblast, and compared with that of iPS cells with four factors in public database. These data are valuable in understanding species difference in the reprogramming process of stem cells, and could help identify the key regulating genes involved in the process.
Collapse
Affiliation(s)
- Tomokazu Fukuda
- Graduate School of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate, 020-8551 Japan.,Soft Path Engineering Research Center (SPERC), Iwate University, 4-3-5 Ueda, Morioka, Iwate, 020-8551 Japan
| | - Koji Doi
- Tsukuba Gene Technology Laboratories Inc., Tsuchiura, 6-320 Arakawaoki, 300-0873 Japan
| | - Kenichiro Donai
- Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572 Japan
| | - Kouhei Takahashi
- Graduate School of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate, 020-8551 Japan
| | - Hisato Kobayashi
- NODAI Genome Research Center, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo, 156-8502 Japan.,Department of Embryology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, 634-8521 Japan
| | - Takashi Hirano
- Faculty of Agriculture, Tokyo University of Agriculture, 1737 Funako, Atsugi-shi, Kanagawa, 243-0034 Japan
| | - Katsuhiko Nishimori
- Graduate School of Agricultural Science, Tohoku University, 468-1, Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572 Japan
| | - Hiroshi Yasue
- Tsukuba Gene Technology Laboratories Inc., Tsuchiura, 6-320 Arakawaoki, 300-0873 Japan
| |
Collapse
|
9
|
DNA repair and replication links to pluripotency and differentiation capacity of pig iPS cells. PLoS One 2017; 12:e0173047. [PMID: 28253351 PMCID: PMC5333863 DOI: 10.1371/journal.pone.0173047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 02/14/2017] [Indexed: 01/05/2023] Open
Abstract
Pigs are proposed to be suitable large animal models for test of the efficacy and safety of induced pluripotent stem cells (iPSCs) for stem cell therapy, but authentic pig ES/iPS cell lines with germline competence are rarely produced. The pathways or signaling underlying the defective competent pig iPSCs remain poorly understood. By improving induction conditions using various small chemicals, we generated pig iPSCs that exhibited high pluripotency and differentiation capacity that can contribute to chimeras. However, their potency was reduced with increasing passages by teratoma formation test, and correlated with declined expression levels of Rex1, an important marker for naïve state. By RNA-sequencing analysis, genes related to WNT signaling were upregulated and MAPK signaling and TGFβ pathways downregulated in pig iPSCs compared to fibroblasts, but they were abnormally expressed during passages. Notably, pathways involving in DNA repair and replication were upregulated at early passage, but downregulated in iPSCs during prolonged passage in cluster with fibroblasts. Our data suggests that reduced DNA repair and replication capacity links to the instability of pig iPSCs. Targeting these pathways may facilitate generation of truly pluripotent pig iPSCs, with implication in translational studies.
Collapse
|
10
|
Mao J, Zhang Q, Deng W, Wang H, Liu K, Fu H, Zhao Q, Wang X, Liu L. Epigenetic Modifiers Facilitate Induction and Pluripotency of Porcine iPSCs. Stem Cell Reports 2016; 8:11-20. [PMID: 28041878 PMCID: PMC5233437 DOI: 10.1016/j.stemcr.2016.11.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 11/27/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022] Open
Abstract
Inadequate silencing of exogenous genes represents a major obstacle to complete epigenetic reprogramming of porcine-induced pluripotent stem cells (piPSCs) by conventional pluripotency transcription factors (OSKM). We tested the hypothesis that epigenetic modification by active DNA or histone demethylation or by inhibition of histone deacetylase would enhance reprogramming and exogenous gene silencing in piPSCs. piPSCs induced by OSKM in combination with epigenetic factors, specifically Ten-Eleven Translocation (Tet1 or Tet3) or lysine (K)-specific demethylase 3A (Kdm3a), expressed higher levels of Rex1 and other genes representing naive state and exhibited more open chromatin status, compared with those of OSKM controls. Tet1 also improved differentiation capacity. Conversion with inhibitors of histone deacetylases (HDACi), NaB, TSA, or VPA, further increased Rex1 expression, while decreasing expression of exogenous genes. piPSCs induced by Tet1+OSKM followed by conversion with HDACi show high pluripotency. Together, epigenetic modifiers enhance generation of piPSCs and reduce their reliance on exogenous genes. Epigenetic modifiers facilitate induction and quality of porcine iPSCs Tet1, Tet3, or Kdm3a increases naive pluripotency network in association with Rex1 Unlike cytoplasmic Rex1, nuclear expression of Rex1 is associated with high pluripotency HDAC inhibitors further activate Rex1 and reduce reliance on the exogenous genes
Collapse
Affiliation(s)
- Jian Mao
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Qian Zhang
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Wei Deng
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hua Wang
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Kai Liu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Haifeng Fu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Qiang Zhao
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xumin Wang
- Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China.
| |
Collapse
|
11
|
Fukuda T, Tani T, Haraguchi S, Donai K, Nakajima N, Uenishi H, Eitsuka T, Miyagawa M, Song S, Onuma M, Hoshino Y, Sato E, Honda A. Expression of Six Proteins Causes Reprogramming of Porcine Fibroblasts Into Induced Pluripotent Stem Cells With Both Active X Chromosomes. J Cell Biochem 2016; 118:537-553. [DOI: 10.1002/jcb.25727] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 09/06/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Tomokazu Fukuda
- United Graduate School of Agricultural Sciences; Iwate University; 4-3-5, Ueda Morioka 020-8551 Iwate Japan
| | - Tetsuya Tani
- Laboratory of Animal Reproduction; Department of Advanced Bioscience; Faculty of Agriculture; Kindai University; 3327-204 Nakamachi Nara 631-8505 Japan
| | - Seiki Haraguchi
- Division of Animal Sciences; Animal Biotechnology Unit; Institute of Agrobiological Sciences; National Agriculture and Food Research Organization (NARO); Tsukuba Ibaraki 305-0901 Japan
| | - Kenichiro Donai
- Graduate School of Agricultural Science; Tohoku University; Sendai 981-8555 Japan
| | - Nobuyoshi Nakajima
- Center for Environmental Biology and Ecosystem Studies; National Institute of Environmental Studies; Tsukuba Japan
| | - Hirohide Uenishi
- Animal Bioregulation Unit; Division of Animal Sciences; Institute of Agrobiological Sciences; National Agriculture and Food Research Organization (NARO); 1-2 Owashi Tsukuba Ibaraki 305-8634 Japan
| | - Takahiro Eitsuka
- Faculty of Applied Life Sciences; Niigata University of Pharmacy and Applied Life Sciences; Niigata Japan
| | - Makoto Miyagawa
- Central Experimental Animal Center; Teikyo University School of Medicine; Japan
| | - Sanghoun Song
- Faculty of Life and Environmental Science; Shimane University; Matsue Shimane Japan
| | - Manabu Onuma
- Center for Environmental Biology and Ecosystem Studies; National Institute of Environmental Studies; Tsukuba Japan
| | - Yumi Hoshino
- Laboratory of Reproductive Endocrinology, Graduate School of Biosphere Science; Hiroshima University; Higashi-Hiroshima, Kagamiyama 1-4-4 Hiroshima 739-8528 Japan
| | - Eimei Sato
- National Livestock Breeding Center; Odakurahara, Odakura, Nishigo-mura, Nishishirakawa-gun Fukushima 961-8511 Japan
| | - Arata Honda
- Organization for Promotion of Tenure Track; University of Miyazaki; 5200 Kihara Kiyotake Miyazaki 889-1692 Japan
| |
Collapse
|
12
|
Apoptosis in Porcine Pluripotent Cells: From ICM to iPSCs. Int J Mol Sci 2016; 17:ijms17091533. [PMID: 27626414 PMCID: PMC5037808 DOI: 10.3390/ijms17091533] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 08/04/2016] [Accepted: 09/08/2016] [Indexed: 01/28/2023] Open
Abstract
Pigs have great potential to provide preclinical models for human disease in translational research because of their similarities with humans. In this regard, porcine pluripotent cells, which are able to differentiate into cells of all three primary germ layers, might be a suitable animal model for further development of regenerative medicine. Here, we describe the current state of knowledge on apoptosis in pluripotent cells including inner cell mass (ICM), epiblast, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs). Information is focused on the apoptotic phenomenon in pluripotency, maintenance, and differentiation of pluripotent stem cells and reprogramming of somatic cells in pigs. Additionally, this review examines the multiple roles of apoptosis and summarizes recent progress in porcine pluripotent cells.
Collapse
|
13
|
Du X, Feng T, Yu D, Wu Y, Zou H, Ma S, Feng C, Huang Y, Ouyang H, Hu X, Pan D, Li N, Wu S. Barriers for Deriving Transgene-Free Pig iPS Cells with Episomal Vectors. Stem Cells 2016; 33:3228-38. [PMID: 26138940 DOI: 10.1002/stem.2089] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/23/2015] [Accepted: 06/15/2015] [Indexed: 12/11/2022]
Abstract
To date no authentic embryonic stem cell (ESC) line or germline-competent-induced pluripotent stem cell (iPSC) line has been established for large animals. Despite this fact, there is an impression in the field that large animal ESCs or iPSCs are as good as mouse counterparts. Clarification of this issue is important for a healthy advancement of the stem cell field. Elucidation of the causes of this failure in obtaining high quality iPSCs/ESCs may offer essential clues for eventual establishment of authentic ESCs for large animals including humans. To this end, we first generated porcine iPSCs using nonintegrating replicating episomal plasmids. Although these porcine iPSCs met most pluripotency criteria, they could neither generate cloned piglets through nuclear transfer, nor contribute to later stage chimeras through morula injections or aggregations. We found that the reprogramming genes in iPSCs could not be removed even under negative selection, indicating they are required to maintain self-renewal. The persistent expression of these genes in porcine iPSCs in turn caused differentiation defects in vivo. Therefore, incomplete reprogramming manifested by a reliance on sustained expression of exogenous-reprogramming factors appears to be the main reason for the inability of porcine iPSCs to form iPSC-derived piglets.
Collapse
Affiliation(s)
- Xuguang Du
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Tao Feng
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Dawei Yu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Yuanyuan Wu
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Huiying Zou
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Shuangyu Ma
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Chong Feng
- Department of Gene and Cell Engineering, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Yongye Huang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, People's Republic of China
| | - Hongsheng Ouyang
- Jilin Provincial Key Laboratory of Animal Embryo Engineering, College of Animal Sciences, Jilin University, Changchun, People's Republic of China
| | - Xiaoxiang Hu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Dengke Pan
- Department of Gene and Cell Engineering, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Ning Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Sen Wu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| |
Collapse
|
14
|
Roberts RM, Yuan Y, Genovese N, Ezashi T. Livestock models for exploiting the promise of pluripotent stem cells. ILAR J 2016; 56:74-82. [PMID: 25991700 DOI: 10.1093/ilar/ilv005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Livestock species are widely used as biomedical models. Pigs, in particular, are beginning to have a significant role in regenerative medicine for testing the applicability, success, and safety of grafts derived from induced pluripotent stem cells. Animal testing must always be performed before any clinical trials are performed in humans, and pigs may sometimes be the species of choice because of their physiological and anatomical similarities to humans. Induced pluripotent stem cells (iPSC) have been generated with some success from livestock species by a variety of reprogramming procedures, but authenticated embryonic stem cells (ESC) have not. There are now several studies in which porcine iPSC have been tested for their ability to provide functional grafts in pigs. Pigs have also served as recipients for grafts derived from human iPSC. There have also been recent advances in creating pigs with severe combined immunodeficiency (SCID). Like SCID mice, these pigs are expected to be graft tolerant. Additionally, chimeric, partially humanized pigs could be sources of human organs. Another potential application of pluripotent stem cells from livestock is for the purpose of differentiating the cells into skeletal muscle, which, in turn, could be used either to produce cultured meat or to engraft into damaged muscle. None of these technologies has advanced to a stage that they have become mainstream, however. Despite the value of livestock models in regenerative medicine, only a limited number of institutions are able to use these animals.
Collapse
Affiliation(s)
- R Michael Roberts
- R. Michael Roberts, DPhil, is a Curators' Professor in the Division of Animal Sciences and Department of Biochemistry at the University of Missouri. Ye Yuan, PhD, is a research scientist; Nicholas Genovese, PhD, is a postdoctoral fellow; and Toshihiko Ezashi, DVM, PhD, is a research associate professor in the Division of Animal Sciences at the University of Missouri
| | - Ye Yuan
- R. Michael Roberts, DPhil, is a Curators' Professor in the Division of Animal Sciences and Department of Biochemistry at the University of Missouri. Ye Yuan, PhD, is a research scientist; Nicholas Genovese, PhD, is a postdoctoral fellow; and Toshihiko Ezashi, DVM, PhD, is a research associate professor in the Division of Animal Sciences at the University of Missouri
| | - Nicholas Genovese
- R. Michael Roberts, DPhil, is a Curators' Professor in the Division of Animal Sciences and Department of Biochemistry at the University of Missouri. Ye Yuan, PhD, is a research scientist; Nicholas Genovese, PhD, is a postdoctoral fellow; and Toshihiko Ezashi, DVM, PhD, is a research associate professor in the Division of Animal Sciences at the University of Missouri
| | - Toshihiko Ezashi
- R. Michael Roberts, DPhil, is a Curators' Professor in the Division of Animal Sciences and Department of Biochemistry at the University of Missouri. Ye Yuan, PhD, is a research scientist; Nicholas Genovese, PhD, is a postdoctoral fellow; and Toshihiko Ezashi, DVM, PhD, is a research associate professor in the Division of Animal Sciences at the University of Missouri
| |
Collapse
|
15
|
Petkov S, Glage S, Nowak-Imialek M, Niemann H. Long-Term Culture of Porcine Induced Pluripotent Stem-Like Cells Under Feeder-Free Conditions in the Presence of Histone Deacetylase Inhibitors. Stem Cells Dev 2016; 25:386-94. [PMID: 26691930 DOI: 10.1089/scd.2015.0317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) is a complex process that involves significant epigenetic alterations in the reprogrammed cells. Epigenetic modifiers such as histone deacetylase (HDAC) inhibitors have been shown to increase the efficiency of derivation of iPSCs in humans and mice. In this study, we used three HDAC inhibitors, valproic acid, sodium butyrate, and suberoylanilide hydroxamic acid, together with ascorbic acid, for derivation and long-term feeder-free culture of porcine iPS-like cells. In the absence of exogenous growth factors and/or small molecules, these inhibitors were able to maintain the expression of key pluripotency markers, including genes known to be specific for naive pluripotent state in mouse stem cells, for over 60 passages under feeder-free conditions. Surprisingly, the cells became dependent on HDAC inhibitors for the maintenance of proliferation. Moreover, despite showing successful integration into blastocysts upon injection, the cells were unable to undergo normal differentiation in vitro and in vivo in the form of teratomas. Our results suggest that HDAC inhibitors maintain pluripotency gene expression of porcine iPSC-like cells in long-term culture, but prevent lineage specification, requiring further optimization of culture conditions for porcine iPSC derivation.
Collapse
Affiliation(s)
- Stoyan Petkov
- 1 Department of Biotechnology, Institute for Farm Animal Genetics (FLI) , Neustadt, Germany
| | - Silke Glage
- 2 Department of Experimental Pathology, Institute for Laboratory Animal Science , Hannover Medical School (MHH), Hannover, Germany
| | - Monika Nowak-Imialek
- 1 Department of Biotechnology, Institute for Farm Animal Genetics (FLI) , Neustadt, Germany
| | - Heiner Niemann
- 1 Department of Biotechnology, Institute for Farm Animal Genetics (FLI) , Neustadt, Germany
| |
Collapse
|
16
|
Teichroeb JH, Kim J, Betts DH. The role of telomeres and telomerase reverse transcriptase isoforms in pluripotency induction and maintenance. RNA Biol 2016; 13:707-19. [PMID: 26786236 DOI: 10.1080/15476286.2015.1134413] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Telomeres are linear guanine-rich DNA structures at the ends of chromosomes. The length of telomeric DNA is actively regulated by a number of mechanisms in highly proliferative cells such as germ cells, cancer cells, and pluripotent stem cells. Telomeric DNA is synthesized by way of the ribonucleoprotein called telomerase containing a reverse transcriptase (TERT) subunit and RNA component (TERC). TERT is highly conserved across species and ubiquitously present in their respective pluripotent cells. Recent studies have uncovered intricate associations between telomeres and the self-renewal and differentiation properties of pluripotent stem cells. Interestingly, the past decade's work indicates that the TERT subunit also has the capacity to modulate mitochondrial function, to remodel chromatin structure, and to participate in key signaling pathways such as the Wnt/β-catenin pathway. Many of these non-canonical functions do not require TERT's catalytic activity, which hints at possible functions for the extensive number of alternatively spliced TERT isoforms that are highly expressed in pluripotent stem cells. In this review, some of the established and potential routes of pluripotency induction and maintenance are highlighted from the perspectives of telomere maintenance, known TERT isoform functions and their complex regulation.
Collapse
Affiliation(s)
- Jonathan H Teichroeb
- a Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry , The University of Western Ontario , London , Ontario , Canada
| | - Joohwan Kim
- a Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry , The University of Western Ontario , London , Ontario , Canada
| | - Dean H Betts
- a Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry , The University of Western Ontario , London , Ontario , Canada.,b Children's Health Research Institute, Lawson Health Research Institute , London , Ontario , Canada
| |
Collapse
|
17
|
Shimamoto A, Yokote K, Tahara H. Werner Syndrome-specific induced pluripotent stem cells: recovery of telomere function by reprogramming. Front Genet 2015; 6:10. [PMID: 25688260 PMCID: PMC4310323 DOI: 10.3389/fgene.2015.00010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/10/2015] [Indexed: 01/10/2023] Open
Abstract
Werner syndrome (WS) is a rare human autosomal recessive premature aging disorder characterized by early onset of aging-associated diseases, chromosomal instability, and cancer predisposition. The function of the DNA helicase encoded by WRN, the gene responsible for WS, has been studied extensively. WRN helicase is involved in the maintenance of chromosome integrity through DNA replication, repair, and recombination by interacting with a variety of proteins associated with DNA repair and telomere maintenance. The accelerated aging associated with WS is reportedly caused by telomere dysfunction, and the underlying mechanism of the disease is yet to be elucidated. Although it was reported that the life expectancy for patients with WS has improved over the last two decades, definitive therapy for these patients has not seen much development. Severe symptoms of the disease, such as leg ulcers, cause a significant decline in the quality of life in patients with WS. Therefore, the establishment of new therapeutic strategies for the disease is of utmost importance. Induced pluripotent stem cells (iPSCs) can be established by the introduction of several pluripotency genes, including Oct3/4, Sox2, Klf4, and c-myc into differentiated cells. iPSCs have the potential to differentiate into a variety of cell types that constitute the human body, and possess infinite proliferative capacity. Recent studies have reported the generation of iPSCs from the cells of patients with WS, and they have concluded that reprogramming represses premature senescence phenotypes in these cells. In this review, we summarize the findings of WS patient-specific iPSCs (WS iPSCs) and focus on the roles of telomere and telomerase in the maintenance of these cells. Finally, we discuss the potential use of WS iPSCs for clinical applications.
Collapse
Affiliation(s)
- Akira Shimamoto
- Department of Cellular and Molecular Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan
| | - Koutaro Yokote
- Department of Clinical Cell Biology and Medicine, Graduate School of Medicine, Chiba University Chiba, Japan
| | - Hidetoshi Tahara
- Department of Cellular and Molecular Biology, Graduate School of Biomedical and Health Sciences, Hiroshima University Hiroshima, Japan
| |
Collapse
|
18
|
Kong Q, Ji G, Xie B, Li J, Mao J, Wang J, Liu S, Liu L, Liu Z. Telomere elongation facilitated by trichostatin a in cloned embryos and pigs by somatic cell nuclear transfer. Stem Cell Rev Rep 2014; 10:399-407. [PMID: 24510582 DOI: 10.1007/s12015-014-9499-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Telomere attrition and genomic instability are associated with organism aging. Concerns still exist regarding telomere length resetting in cloned embryos and ntES cells, and possibilities of premature aging of cloned animals achieved by somatic cell nuclear transfer (SCNT). Trichostatin A (TSA), a histone deacetylase inhibitor, effectively improves the developmental competence of cloned embryos and animals, and recently contributes to successful generation of human ntES cells by SCNT. To test the function of TSA on resetting telomere length, we analyzed telomeres in cloned blastocysts and pigs following treatment of SCNT embryos with TSA. Here, we show that telomeres of cloned pigs generated by standard SCNT methods are not effectively restored, compared with those of donor cells, however TSA significantly increases telomere lengths in cloned pigs. Telomeres elongate in cloned porcine embryos during early cleavage from one-cell to four-cell stages. Notably, TSA facilitates telomere lengthening of cloned embryos mainly at morula-blastocyst stages. Knockdown of pTert by shRNA in donor cells reduces telomerase activity in cloned blastocysts but does not abrogate telomere elongation in the TSA-treated embryos (p > 0.05). However, genes associated with recombination or telomerase-independent mechanism of alternative lengthening of telomeres (ALT) Rad50 and BLM show increased expression in TSA-treated embryos. These data suggest that TSA may promote telomere elongation of cloned porcine embryos by ALT. Together, TSA can elongate telomeres in cloned embryos and piglets, and this could be one of the mechanisms underlying improved development of cloned embryos and animals treated with TSA.
Collapse
Affiliation(s)
- Qingran Kong
- Laboratory of Embryo Biotechnology, College of Life Science, Northeast Agricultural University, Harbin, China,
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
Pluripotent stem cells (PSCs) have the potential to produce any types of cells from all three basic germ layers and the capacity to self-renew and proliferate indefinitely in vitro. The two main types of PSCs, embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), share common features such as colony morphology, high expression of Oct4 and Nanog, and strong alkaline phosphatase activity. In recent years, increasing evidences suggest that telomere length represents another important internal factor in maintaining stem cell pluripotency. Telomere length homeostasis and its structural integrity help to protect chromosome ends from recombination, end fusion, and DNA damage responses, ensuring the divisional ability of mammalian cells. PSCs generally exhibit high telomerase activity to maintain their extremely long and stable telomeres, and emerging data indicate the alternative lengthening of telomeres (ALT) pathway may play an important role in telomere functions too. Such characteristics are likely key to their abilities to differentiate into diverse cell types in vivo. In this review, we will focus on the function and regulation of telomeres in ESCs and iPSCs, thereby shedding light on the importance of telomere length to pluripotency and the mechanisms that regulate telomeres in PSCs.
Collapse
|