1
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Tsai LK, Peng M, Chang CC, Wen L, Liu L, Liang X, Chen YE, Xu J, Sung LY. ZSCAN4 interacts with PARP1 to promote DNA repair in mouse embryonic stem cells. Cell Biosci 2023; 13:193. [PMID: 37875990 PMCID: PMC10594928 DOI: 10.1186/s13578-023-01140-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 10/05/2023] [Indexed: 10/26/2023] Open
Abstract
BACKGROUND In eukaryotic cells, DNA double strand breaks (DSB) are primarily repaired by canonical non-homologous end joining (c-NHEJ), homologous recombination (HR) and alternative NHEJ (alt-NHEJ). Zinc finger and SCAN domain containing 4 (ZSCAN4), sporadically expressed in 1-5% mouse embryonic stem cells (mESCs), is known to regulate genome stability by promoting HR. RESULTS Here we show that ZSCAN4 promotes DNA repair by acting with Poly (ADP-ribose) polymerase 1 (PARP1), which is a key member of the alt-NHEJ pathway. In the presence of PARP1, ZSCAN4-expressing mESCs are associated with lower extent of endogenous or chemical induced DSB comparing to ZSCAN4-negative ones. Reduced DSBs associated with ZSCAN4 are abolished by PARP1 inhibition, achieved either through small molecule inhibitor or gene knockout in mESCs. Furthermore, PARP1 binds directly to ZSCAN4, and the second ⍺-helix and the fourth zinc finger motif of ZSCAN4 are critical for this binding. CONCLUSIONS These data reveal that PARP1 and ZSCAN4 have a protein-protein interaction, and shed light on the molecular mechanisms by which ZSCAN4 reduces DSB in mESCs.
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Affiliation(s)
- Li-Kuang Tsai
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Min Peng
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Chia-Chun Chang
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC
| | - Luan Wen
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Xiubin Liang
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Y Eugene Chen
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Jie Xu
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC.
- Center for Developmental Biology and Regenerative Medicine, Taipei, 106, Taiwan, ROC.
- Center for Biotechnology, National Taiwan University, Taipei, 106, Taiwan, ROC.
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 115, Taiwan, ROC.
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2
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Udroiu I, Marinaccio J, Sgura A. Many Functions of Telomerase Components: Certainties, Doubts, and Inconsistencies. Int J Mol Sci 2022; 23:ijms232315189. [PMID: 36499514 PMCID: PMC9736166 DOI: 10.3390/ijms232315189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/23/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
A growing number of studies have evidenced non-telomeric functions of "telomerase". Almost all of them, however, investigated the non-canonical effects of the catalytic subunit TERT, and not the telomerase ribonucleoprotein holoenzyme. These functions mainly comprise signal transduction, gene regulation and the increase of anti-oxidative systems. Although less studied, TERC (the RNA component of telomerase) has also been shown to be involved in gene regulation, as well as other functions. All this has led to the publication of many reviews on the subject, which, however, are often disseminating personal interpretations of experimental studies of other researchers as original proofs. Indeed, while some functions such as gene regulation seem ascertained, especially because mechanistic findings have been provided, other ones remain dubious and/or are contradicted by other direct or indirect evidence (e.g., telomerase activity at double-strand break site, RNA polymerase activity of TERT, translation of TERC, mitochondrion-processed TERC). In a critical study of the primary evidence so far obtained, we show those functions for which there is consensus, those showing contradictory results and those needing confirmation. The resulting picture, together with some usually neglected aspects, seems to indicate a link between TERT and TERC functions and cellular stemness and gives possible directions for future research.
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3
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Tsai LK, Ou-Yang H, Xu J, Chen CM, Chang WF, Sung LY. Effects of Recloning on the Telomere Lengths of Mouse Terc+/- Nuclear Transfer-Derived Embryonic Stem Cells. Stem Cells Dev 2022; 31:720-729. [PMID: 35801658 DOI: 10.1089/scd.2022.0115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Haploinsufficiency of genes that participate in the telomere elongation and maintenance processes, such as Terc and Tert, often lead to premature aging related diseases such as dyskeratosis congenita and aplastic anemia. Previously we reported that when mouse Terc+/- tail tip fibroblasts (TTFs) were used as the donor cells for somatic cell nuclear transfer (SCNT, also known as "cloning"), the derivative embryonic stem cells (ntESCs) had elongated telomeres. In the present work, we are interested to know if an additional round of SCNT, or recloning, could bring further elongation of the telomeres. Terc+/- TTFs were used to derive the first generation (G1) ntESCs, followed by a second round SCNT using G1-Terc+/- ntESCs as donor cells to derive G2-Tert+/- ntESCs. Multiple lines of G1- and G2-Terc+/- ntESCs were efficiently established, and all expressed major pluripotent markers and supported efficient chondrocyte differentiation in vitro. Comparing to the donor TTFs, telomere lengths of G1-ntESCs were elongated to the level comparable to that in wildtype ntESCs. Interestingly, recloning did not further elongate telomere lengths of the Terc+/- ntESCs. Together, our work demonstrates that while a single round of SCNT is a viable means to reprogram Terc haploinsufficient cells to the ESC state, and to elongate these cells' telomere lengths, a second round of SCNT does not necessarily further elongate the telomeres.
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Affiliation(s)
- Li-Kuang Tsai
- National Taiwan University, 33561, Institute of Biotechnology, Taipei, Taiwan;
| | - Huan Ou-Yang
- National Taiwan University, 33561, Institute of Biotechnology, Taipei, Taiwan;
| | - Jie Xu
- University of Michigan Medical Center, 166144, Ann Arbor, Michigan, United States;
| | - Chuan-Mu Chen
- National Chung Hsing University, 34916, Taichung, Taiwan;
| | - Wei-Fang Chang
- National Taiwan University, 33561, Institute of Biotechnology, Taipei, Taiwan;
| | - Li-Ying Sung
- National Taiwan University, 33561, Institute of Biotechnology, Taipei, Taiwan, 10617;
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4
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Wang H, Li B, Lu Y, Han K, Sheng H, Zhou J, Qi Y, Wang X, Huang Z, Song L, Hua Y. Real-time threshold determination of auditory brainstem responses by cross-correlation analysis. iScience 2021; 24:103285. [PMID: 34765914 PMCID: PMC8571499 DOI: 10.1016/j.isci.2021.103285] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/25/2021] [Accepted: 10/13/2021] [Indexed: 12/02/2022] Open
Abstract
Auditory brainstem response (ABR) serves as an objective indication of auditory perception at a given sound level and is nowadays widely used in hearing function assessment. Despite efforts for automation over decades, ABR threshold determination by machine algorithms remains unreliable and thereby one still relies on visual identification by trained personnel. Here, we described a procedure for automatic threshold determination that can be used in both animal and human ABR tests. The method terminates level averaging of ABR recordings upon detection of time-locked waveform through cross-correlation analysis. The threshold level was then indicated by a dramatic increase in the sweep numbers required to produce “qualified” level averaging. A good match was obtained between the algorithm outcome and the human readouts. Moreover, the method varies the level averaging based on the cross-correlation, thereby adapting to the signal-to-noise ratio of sweep recordings. These features empower a robust and fully automated ABR test. Automatic threshold determination of auditory brainstem response (ABR) Detection of “clear” responses from iteratively averaged level representation Wide application in both animal and human ABR tests Stop on-going level averaging based on detection outcome
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Affiliation(s)
- Haoyu Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.,Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bei Li
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China
| | - Yan Lu
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Kun Han
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China
| | - Haibin Sheng
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Jialei Zhou
- Department of Otorhinolaryngology-Head & Neck Surgery, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yumeng Qi
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xueling Wang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Zhiwu Huang
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Lei Song
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Yunfeng Hua
- Department of Otolaryngology-Head and Neck Surgery, Shanghai Ninth People's Hospital, Shanghai, China.,Ear Institute, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.,Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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5
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Simpson DJ, Olova NN, Chandra T. Cellular reprogramming and epigenetic rejuvenation. Clin Epigenetics 2021; 13:170. [PMID: 34488874 PMCID: PMC8419998 DOI: 10.1186/s13148-021-01158-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
Ageing is an inevitable condition that afflicts all humans. Recent achievements, such as the generation of induced pluripotent stem cells, have delivered preliminary evidence that slowing down and reversing the ageing process might be possible. However, these techniques usually involve complete dedifferentiation, i.e. somatic cell identity is lost as cells are converted to a pluripotent state. Separating the rejuvenative properties of reprogramming from dedifferentiation is a promising prospect, termed epigenetic rejuvenation. Reprogramming-induced rejuvenation strategies currently involve using Yamanaka factors (typically transiently expressed to prevent full dedifferentiation) and are promising candidates to safely reduce biological age. Here, we review the development and potential of reprogramming-induced rejuvenation as an anti-ageing strategy.
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Affiliation(s)
- Daniel J Simpson
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, EH4 2XU, UK.
| | - Nelly N Olova
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, EH4 2XU, UK.
| | - Tamir Chandra
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, EH4 2XU, UK.
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6
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Chang WF, Wu YH, Xu J, Sung LY. Compromised Chondrocyte Differentiation Capacity in TERC Knockout Mouse Embryonic Stem Cells Derived by Somatic Cell Nuclear Transfer. Int J Mol Sci 2019; 20:ijms20051236. [PMID: 30870992 PMCID: PMC6429130 DOI: 10.3390/ijms20051236] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/26/2019] [Accepted: 03/07/2019] [Indexed: 12/18/2022] Open
Abstract
Mammalian telomere lengths are primarily regulated by telomerase, consisting of a reverse transcriptase protein (TERT) and an RNA subunit (TERC). We previously reported the generation of mouse Terc+/- and Terc-/- embryonic stem cells (ntESCs) by somatic cell nuclear transfer. In the present work, we investigated the germ layer development competence of Terc-/-, Terc+/- and wild-type (Terc+/+) ntESCs. The telomere lengths are longest in wild-type but shortest in Terc-/- ntESCs, and correlate reversely with the population doubling time. Interestingly, while in vitro embryoid body (EB) differentiation assay reveals EB size difference among ntESCs of different genotypes, the more stringent in vivo teratoma assay demonstrates that Terc-/- ntESCs are severely defective in differentiating into the mesodermal lineage cartilage. Consistently, in a directed in vitro chondrocyte differentiation assay, the Terc-/- cells failed in forming Collagen II expressing cells. These findings underscore the significance in maintaining proper telomere lengths in stem cells and their derivatives for regenerative medicine.
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Affiliation(s)
- Wei-Fang Chang
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan.
| | - Yun-Hsin Wu
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan.
| | - Jie Xu
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA.
| | - Li-Ying Sung
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan.
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan.
- Animal Resource Center, National Taiwan University, Taipei 106, Taiwan.
- Center for Biotechnology, National Taiwan University, Taipei 106, Taiwan.
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7
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Liu FW, Liao HF, Lin SP, Lu YW. DNA methylation assay using droplet-based DNA melting curve analysis. LAB ON A CHIP 2018; 18:514-521. [PMID: 29327010 DOI: 10.1039/c7lc01240c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
DNA methylation is an epigenetic regulation of gene expression, which has drawn great attention in biomedical research due to its association with various diseases. A robust, inexpensive platform to detect and quantify the methylation status in a specific genomic region is necessary. In this study, an on-chip analytical technique of cytosine methylation with droplets in a microchannel is proposed. Genomic DNA samples are encapsulated into a series of droplets and transported through a detection region, where a stable temperature gradient is created. As the temperature is elevated from 60 °C to 85 °C, the DNA samples denature and the associated fluorescence signals decay, with the relationship being acquired as the melting curve. The droplets serve as discrete reactors for conducting DNA melting curve analysis in the liquid phase, thereby eliminating the need for immobilization of reagents. Due to a high heating rate and greater enhanced thermal stability, this microchip allows larger melting temperature differences for the samples at different percentages of methylated DNA. It has an enhanced discrimination ability and lower volume consumption, compared to the commercial qPCR machine. This chip enables quantification of the methylation levels of the pluripotent stem cell factor Oct-4 in its distal enhancer (DE) region, with a designed probe after bisulfite treatment and asymmetric PCR.
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Affiliation(s)
- F-W Liu
- Dept. of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan, ROC.
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8
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Wang H, Zhang K, Liu Y, Fu Y, Gao S, Gong P, Wang H, Zhou Z, Zeng M, Wu Z, Sun Y, Chen T, Li S, Liu L. Telomere heterogeneity linked to metabolism and pluripotency state revealed by simultaneous analysis of telomere length and RNA-seq in the same human embryonic stem cell. BMC Biol 2017; 15:114. [PMID: 29216888 PMCID: PMC5721592 DOI: 10.1186/s12915-017-0453-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 11/08/2017] [Indexed: 12/13/2022] Open
Abstract
Background Telomere length heterogeneity has been detected in various cell types, including stem cells and cancer cells. Cell heterogeneity in pluripotent stem cells, such as embryonic stem cells (ESCs), is of particular interest; however, the implication and mechanisms underlying the heterogeneity remain to be understood. Single-cell analysis technology has recently been developed and effectively employed to investigate cell heterogeneity. Yet, methods that can simultaneously measure telomere length and analyze the global transcriptome in the same cell have not been available until now. Results We have established a robust method that can simultaneously measure telomere length coupled with RNA-sequencing analysis (scT&R-seq) in the same human ESC (hESC). Using this method, we show that telomere length varies with pluripotency state. Compared to those with long telomere, hESCs with short telomeres exhibit the lowest expressions of TERF1/TRF1, and ZFP42/REX1, PRDM14 and NANOG markers for pluripotency, suggesting that these hESCs are prone to exit from the pluripotent state. Interestingly, hESCs ubiquitously express NOP10 and DKC1, stabilizing components of telomerase complexes. Moreover, new candidate genes, such as MELK, MSH6, and UBQLN1, are highly expressed in the cluster of cells with long telomeres and higher expression of known pluripotency markers. Notably, short telomere hESCs exhibit higher oxidative phosphorylation primed for lineage differentiation, whereas long telomere hESCs show elevated glycolysis, another key feature for pluripotency. Conclusions Telomere length is a marker of the metabolic activity and pluripotency state of individual hESCs. Single cell analysis of telomeres and RNA-sequencing can be exploited to further understand the molecular mechanisms of telomere heterogeneity. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0453-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hua Wang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Kunshan Zhang
- Stem Cell Translational Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
| | - Yifei Liu
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Yudong Fu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Shan Gao
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Peng Gong
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Haiying Wang
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Zhongcheng Zhou
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Ming Zeng
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China.,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Zhenfeng Wu
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Yu Sun
- Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Tong Chen
- EHBIO Gene Technology co., LTD, Beijing, 100029, China
| | - Siguang Li
- Stem Cell Translational Research Center, Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China.
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300071, China. .,Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, 300071, China.
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9
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Liu L. Linking Telomere Regulation to Stem Cell Pluripotency. Trends Genet 2016; 33:16-33. [PMID: 27889084 DOI: 10.1016/j.tig.2016.10.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Revised: 10/18/2016] [Accepted: 10/31/2016] [Indexed: 12/31/2022]
Abstract
Embryonic stem cells (ESCs), somatic cell nuclear transfer ESCs, and induced pluripotent stem cells (iPSCs) represent the most studied group of PSCs. Unlimited self-renewal without incurring chromosomal instability and pluripotency are essential for the potential use of PSCs in regenerative therapy. Telomere length maintenance is critical for the unlimited self-renewal, pluripotency, and chromosomal stability of PSCs. While telomerase has a primary role in telomere maintenance, alternative lengthening of telomere pathways involving recombination and epigenetic modifications are also required for telomere length regulation, notably in mouse PSCs. Telomere rejuvenation is part of epigenetic reprogramming to pluripotency. Insights into telomere reprogramming and maintenance in PSCs may have implications for understanding of aging and tumorigenesis. Here, I discuss the link between telomere elongation and homeostasis to the acquisition and maintenance of stem cell pluripotency, and their regulatory mechanisms by epigenetic modifications.
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Affiliation(s)
- Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Department of Cell Biology and Genetics, College of Life Sciences, Collaborative Innovation Center for Biotherapy, Nankai University, Tianjin 300071, China.
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10
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Zhang Q, Dan J, Wang H, Guo R, Mao J, Fu H, Wei X, Liu L. Tcstv1 and Tcstv3 elongate telomeres of mouse ES cells. Sci Rep 2016; 6:19852. [PMID: 26816107 PMCID: PMC4728397 DOI: 10.1038/srep19852] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/18/2015] [Indexed: 02/05/2023] Open
Abstract
Mouse embryonic stem cell (ESC) cultures exhibit a heterogeneous mixture of metastable cells sporadically entering the 2-cell (2C)-embryo-like state, critical for ESC potency. One of 2-cell genes, Zscan4, has been shown to be responsible for telomere maintenance, genomic stability and pluripotency of mouse ESCs. Functions of other 2C-genes in ESCs remain elusive. Here we show that 2C-genes Tcstv1 and Tcstv3 play a role in regulation of telomere lengths. Overexpression or knockdown Tcstv1 and Tcstv3 does not immediately affect proliferation, pluripotency and differentiation in vitro of ESCs. However, ectopic expression of Tcstv1 or Tcstv3 results in telomere elongation, whereas Tcstv1/3 knockdown shortens telomeres of ESCs. Overexpression of Tcstv1 or Tcstv3 does not alter telomere stability. Furthermore, Tcstv1 can increase Zscan4 protein levels and telomere recombination by telomere sister chromatid exchange (T-SCE). Depletion of Tcstv1/3 reduces Zscan4 protein levels. Together, Tcstv1 and Tcstv3 are involved in telomere maintenance that is required for long-term self-renewal of mouse ESCs. Our data also suggests that Tcstv1/3 may co-operate and stabilize Zscan4 protein but the molecular bases remain to be determined.
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Affiliation(s)
- Qian Zhang
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jiameng Dan
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Hua Wang
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Renpeng Guo
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jian Mao
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Haifeng Fu
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xiawei Wei
- State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology; 2011 Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin 300071, China
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11
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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: 29] [Impact Index Per Article: 3.6] [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.
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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
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12
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Dan J, Yang J, Liu Y, Xiao A, Liu L. Roles for Histone Acetylation in Regulation of Telomere Elongation and Two-cell State in Mouse ES Cells. J Cell Physiol 2015; 230:2337-44. [PMID: 25752831 DOI: 10.1002/jcp.24980] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 03/02/2015] [Indexed: 01/18/2023]
Abstract
Mammalian telomeres and subtelomeres are marked by heterochromatic epigenetic modifications, including repressive DNA methylation and histone methylation (e.g., H3K9me3 and H4K20me3). Loss of these epigenetic marks results in increased rates of telomere recombination and elongation. Other than these repressive epigenetic marks, telomeric and subtelomeric H3 and H4 are underacetylated. Yet, whether histone acetylation also regulates telomere length has not been directly addressed. We thought to test the effects of histone acetylation levels on telomere length using histone deacetylase (HDAC) inhibitor (sodium butyrate, NaB) that mediates histone hyperacetylation and histone acetyltransferase (HAT) inhibitor (C646) that mediates histone hypoacetylation. We show that histone hyperacetylation dramatically elongates telomeres in wild-type ES cells, and only slightly elongates telomeres in Terc(-/-) ES cells, suggesting that Terc is involved in histone acetylation-induced telomere elongation. In contrast, histone hypoacetylation shortens telomeres in both wild-type and Terc(-/-) ES cells. Additionally, histone hyperacetylation activates 2-cell (2C) specific genes including Zscan4, which is involved in telomere recombination and elongation, whereas histone hypoacetylation represses Zscan4 and 2C genes. These data suggest that histone acetylation levels affect the heterochromatic state at telomeres and subtelomeres, and regulate gene expression at subtelomeres, linking histone acetylation to telomere length maintenance.
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Affiliation(s)
- Jiameng Dan
- State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Jiao Yang
- State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
| | - Yifei Liu
- Yale Stem Cell Center and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Andrew Xiao
- Yale Stem Cell Center and Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | - Lin Liu
- State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center for Biotherapy, Department of Cell Biology and Genetics, College of Life Sciences, Nankai University, Tianjin, China
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