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Kim SM, Wada KI, Ueki M, Hosokawa K, Maeda M, Sakai Y, Ito Y. Cytoplasmic fusion between an enlarged embryonic stem cell and a somatic cell using a microtunnel device. Biochem Biophys Res Commun 2019; 520:257-262. [PMID: 31594640 DOI: 10.1016/j.bbrc.2019.09.131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 09/28/2019] [Indexed: 11/19/2022]
Abstract
Based on a previous finding that fusion of a somatic cell with an embryonic stem (ES) cell reprogrammed the somatic cell, genes for reprogramming transcription factors were selected and induced pluripotent stem (iPS) cell technology was developed. The cell fusion itself produced a tetraploid cell. To avoid nuclear fusion, a method for cytoplasmic fusion using a microtunnel device was developed. However, the ES cell was too small for cell pairing at the device. Therefore, in the present study, ES cell enlargement was carried out with the colchicine derivative demecolcine (DC). DC induced enlargement of ES cells without loss of their stemness. When an enlarged ES cell was paired with a somatic cell in the microtunnel device, cytoplasmic fusion was observed. The present method may be useful for further development of reprogramming techniques for iPS cell preparation without gene transfection.
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Affiliation(s)
- Seong Min Kim
- Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Ken-Ichi Wada
- Bioengineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Masashi Ueki
- Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Kazuo Hosokawa
- Bioengineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Mizuo Maeda
- Bioengineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Yasuyuki Sakai
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoshihiro Ito
- Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan; Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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Fujikawa-Yamamoto K, Miyagoshi M, Yamagishi H. Dodecaploid H1 embryonic stem cells abolished pluripotency in L15F10 medium both with and without leukemia inhibitory factor. Hum Cell 2013; 26:97-104. [PMID: 23460370 DOI: 10.1007/s13577-013-0063-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 02/04/2013] [Indexed: 10/27/2022]
Abstract
Two lines of dodecaploid H1 embryonic stem cells, 12H1 and 12H1(-) cells (mouse-originated cells), were established through polyploidization of two hexaploid H1 cells, 6H1 and 6H1(-) cells, which were cultured in L15F10 (7:3) medium with and without leukemia inhibitory factor (LIF), respectively. The G1, S, and G2/M phase fractions of 12H1 and 12H1(-) cells were almost the same as those of 6H1 and 6H1(-) cells, respectively, but the doubling time of cell proliferation was prolonged, suggesting that cell death occurred in 12H1 and 12H1(-)cells. The cell volumes of 12H1 and 12H1(-) cells were about double those of 6H1 and 6H1(-) cells, respectively. 12H1 and 12H1(-) cells showed near-negative activity of alkaline phosphatase and no ability to form teratocarcinomas in mouse abdomen, suggesting that 12H1 and 12H1(-) cells lost pluripotency. The DNA contents of 12H1 and 12H1(-) cells decayed in long-term culturing, suggesting that 12H1 and 12H1(-) cells were DNA-unstable. Possible explanations for the lost pluripotency and for the DNA decay in 12H1 and 12H1(-) cells are presented.
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Affiliation(s)
- Kohzaburo Fujikawa-Yamamoto
- Division of Cell Medicine, Research Institute of Medical Science, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.
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Fujikawa-Yamamoto K, Ota T, Miyagoshi M, Yamagishi H. Effects of etoposide on the proliferation of hexaploid H1 (ES) cells. Hum Cell 2012; 25:45-50. [PMID: 22614914 DOI: 10.1007/s13577-012-0043-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 02/07/2012] [Indexed: 11/26/2022]
Abstract
Etoposide is a specific inhibitor of topoisomerase II, which is an enzyme that enables double-stranded DNA to pass through another double-stranded DNA. Topoisomerase II is a major constituent of chromosome scaffold, existing at appreciable amounts in cells. To examine the effects of etoposide on the cell cycle, hexaploid H1 (ES) cells (6H1 cells) were used with diploid H1 (ES) cells (2H1 cells) as a control. Exponentially growing 2H1 and 6H1 cells were exposed to etoposide at various concentrations, and cultured for about 60 days in L15F10 medium with leukemia inhibitory factor. With a high concentration of etoposide (1 μM), the DNA histograms showed G(2)/M accumulation, suggesting that etoposide arrested the cell cycle at the G(2)/M phase. With a low concentration of etoposide (50 nM), the cell proliferation was suppressed with a doubling time of 98.4 h for 2H1 cells and 51.6 h for 6H1 cells, and without significant alteration in DNA histograms. Time-lapse videography revealed that 6H1 cells survived in the medium containing 50 nM etoposide had a cell cycle time of 18.8 h, which was equivalent to 19.2 h of the doubling time for the 6H1 cell population in drug-free medium, suggesting that a part of the cell population died and was excluded from the cell system. It was concluded that etoposide affected the cell cycle at a wide range of concentrations.
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Affiliation(s)
- Kohzaburo Fujikawa-Yamamoto
- Division of Cell Medicine, Research Institute of Medical Science, Kanazawa Medical University, Uchinada, Ishikawa, 920-0293, Japan.
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Fujikawa-Yamamoto K, Ota T, Miyagoshi M, Yamagishi H. Pluripotency of a polyploid H1 (ES) cell system without leukaemia inhibitory factor. Cell Prolif 2012; 45:140-7. [PMID: 22288737 DOI: 10.1111/j.1365-2184.2011.00805.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES Tetraploid cells are strictly biologically inhibited from composition of embryos; by the same token, only diploid cells compose embryos. However, the distinction between diploid and tetraploid cells in development has not been well explained. To examine pluripotency of polyploid ES cells, a polyploid embryonic stem (ES)-cell system was prepared. MATERIALS AND METHODS Diploid, tetraploid, pentaploid, hexaploid, octaploid and decaploid H1 (ES) cells (2H1, 4H1, 5H1, 6H1, 8H1 and 10H1 cells, respectively) were cultured for about 460 days in L15F10 medium without leukaemia inhibitory factor (LIF). The cells cultured under LIF-free conditions were denoted as 2H1(-), 4H1(-), 5H1(-), 6H1(-), 8H1(-) and 10H1(-) cells, respectively. Pluripotency and gene expression were examined. RESULTS Ploidy alteration of H1(-) cells was similar to that of H1 cells. The polyploid H1(-) cells showed positive activity of alkaline phosphatase, suggesting that they maintained pluripotency in vitro without LIF. The polyploid H1(-) cells formed teratocarcinomas in mouse abdomen, suggesting they could differentiate in mouse abdomen in vivo. 2H1, 4H1 and polyploid H1(-) cells expressed nanog, oct3/4 and sox2 genes, suggesting that they fulfilled the criteria of ES cells. Nanog gene was significantly over-expressed in 4H1 and polyploid H1(-) cells, suggesting that overexpression of nanog gene was a characteristic of polyploid H1 cells. CONCLUSION Polyploid H1 (ES) cells retained pluripotency in vitro, without LIF with nanog over-expression.
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Affiliation(s)
- K Fujikawa-Yamamoto
- Divisions of Cell MedicineTumor Biology, Research Institute of Medical Science, Kanazawa Medical University, Uchinada, Ishikawa, Japan
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Fujikawa-Yamamoto K, Miyagoshi M, Luo X, Yamagishi H. DNA-unstable decaploid mouse H1 (ES) cells established from DNA-stable pentaploid H1 (ES) cells polyploidized using demecolcine. Cell Prolif 2011; 44:111-9. [PMID: 21401752 DOI: 10.1111/j.1365-2184.2011.00734.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES DNA content of diploid H1 (ES) cells (2H1 cells) has been shown to be stable in long-term culture; however, tetraploid and octaploid H1 (ES) cells (4H1 and 8H1 cells, respectively) were DNA-unstable. Pentaploid H1 (ES) cells (5H1 cells) established recently have been found to be DNA-stable; how, then is cell DNA stability determined? To discuss ploidy stability, decaploid H1 (ES) cells (10H1 cells) were established from 5H1 cells and examined for DNA stability. MATERIALS AND METHODS 5H1 cells were polyploidized using demecolcine (DC) and 10H1 cells were obtained by one-cell cloning. RESULTS Number of chromosomes of 10H1 cells was 180 and durations of their G(1), S, and G(2)/M phases were 3, 7 and 6 h respectively. Volume of 10H1 cells was double that of 5H1 cells and morphology of 10H1 cells was flagstone-like in shape. 10H1 cells exhibited alkaline phosphatase activity and their DNA content decayed in 91 days of culture. 10H1 cells injected into mouse abdomen formed solid tumours that contained several kinds of differentiated cells with lower DNA content, suggesting that 10H1 cells were pluripotent and DNA-unstable. Loss of DNA stability was explained using a hypothesis concerning DNA structure of polyploid cells as DNA reconstructed through ploidy doubling was arranged in mirror symmetry in a new configuration. CONCLUSION In the pentaploid-decaploid transition of H1 cells, cell cycle parameters and pluripotency were retained, but morphology and DNA stability were altered.
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Affiliation(s)
- K Fujikawa-Yamamoto
- Division of Cell Medicine, Research Institute of Medical Science, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
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Haploid unit-ploidy transition of tetraploid and octaploid H1 (ES) cells in long-term culturing. Hum Cell 2011; 24:78-85. [DOI: 10.1007/s13577-011-0017-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 04/19/2011] [Indexed: 10/18/2022]
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Hexaploid H1 (ES) cells established from octaploid H1 cells are as DNA stable as pentaploid H1 cells. Hum Cell 2010; 24:13-20. [PMID: 21547691 DOI: 10.1007/s13577-010-0003-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 10/22/2010] [Indexed: 10/18/2022]
Abstract
Hexaploid H1 (ES) cells (6H1 cells) were established from octaploid H1 cells (8H1 cells), as were pentaploid H1 cells (5H1 cells). 6H1 cells were compared with 5H1 cells. The number of chromosomes of 6H1 cells was 115, 20 more than the 95 of 5H1 cells. The durations of G(1), S, and G(2)/M phases of 6H1 cells were 3, 7, and 6 h, respectively, almost the same as those of 5H1 cells. The cell volume of 6H1 cells was equivalent that of 5H1 cells. The morphology of 6H1 cells was flattened circular cluster, different from the spherical cluster of 5H1 cells. 6H1 cells exhibited alkaline phosphatase activity as well as 5H1 cells. The DNA content of 6H1 cells was stable and maintained for 300 days of culturing, the same as that of 5H1 cells. The DNA stability of 6H1 cells was explained using a hypothesis concerning the DNA structure of polyploid cells because the asymmetric configuration of homologous chromosomes in 6H1 cells inhibited chromosome loss.
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Fujikawa-Yamamoto K, Luo X, Miyagoshi M, Yamagishi H. DNA stable pentaploid H1 (ES) cells obtained from an octaploid cell induced from tetraploid cells polyploidized using demecolcine. J Cell Physiol 2010; 223:369-75. [PMID: 20082301 DOI: 10.1002/jcp.22042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Pentaploid H1 (ES) cells (5H1 cells) were accidentally obtained through one-cell cloning of octaploid H1 (ES) cells (8H1 cells) that were established from tetraploid H1 (ES) cells (4H1 cells) polyploidized using demecolcine. The number of chromosomes of 5H1 cells was 100, unlike the 40 of diploid H1 (ES) cells (2H1 cells), 80 of 4H1, and 160 of 8H1 cells. The durations of G(1), S, and G(2)/M phases of 5H1 cells were 3, 7, and 6 h, respectively, almost the same as those of 2H1, 4H1, and 8H1 cells. The cell volume of 5H1 cells was half of that of 8H1 cells, suggesting that 5H1 cells were created through abnormal cell divisions of 8H1 cells. The morphology of growing 5H1 cells was a spherical cluster similar to that of 2H1 cells and differing from the flagstone-like shape of 4H1 and 8H1 cells. Pentaploid solid tumors were formed from 5H1 cells after interperitoneal injection into the mouse abdomen, and they contained endodermal, mesodermal, and ectodermal cells as well as undifferentiated cells, suggesting both that the DNA content of 5H1 cells was retained during tumor formation and that the 5H1 cells were pluripotent. The DNA content of 5H1 cells was stable in long-term culturing as 2H1 cells, meaning that 5H1 and 2H1 cells shared similarities in DNA structure. The excellent stability of the DNA content of 5H1 cells was explained using a hypothesis for the DNA structure of polyploid cells because the pairing of homologous chromosomes in 5H1 cells is spatially forbidden.
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Affiliation(s)
- Kohzaburo Fujikawa-Yamamoto
- Division of Cell Medicine, Research Institute of Medical Science, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan.
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