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Uno N, Satofuka H, Miyamoto H, Honma K, Suzuki T, Yamazaki K, Ito R, Moriwaki T, Hamamichi S, Tomizuka K, Oshimura M, Kazuki Y. Treatment of CHO cells with Taxol and reversine improves micronucleation and microcell-mediated chromosome transfer efficiency. Mol Ther Nucleic Acids 2023; 33:391-403. [PMID: 37547291 PMCID: PMC10403731 DOI: 10.1016/j.omtn.2023.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 07/11/2023] [Indexed: 08/08/2023]
Abstract
Microcell-mediated chromosome transfer is an attractive technique for transferring chromosomes from donor cells to recipient cells and has enabled the generation of cell lines and humanized animal models that contain megabase-sized gene(s). However, improvements in chromosomal transfer efficiency are still needed to accelerate the production of these cells and animals. The chromosomal transfer protocol consists of micronucleation, microcell formation, and fusion of donor cells with recipient cells. We found that the combination of Taxol (paclitaxel) and reversine rather than the conventional reagent colcemid resulted in highly efficient micronucleation and substantially improved chromosomal transfer efficiency from Chinese hamster ovary donor cells to HT1080 and NIH3T3 recipient cells by up to 18.3- and 4.9-fold, respectively. Furthermore, chromosome transfer efficiency to human induced pluripotent stem cells, which rarely occurred with colcemid, was also clearly improved after Taxol and reversine treatment. These results might be related to Taxol increasing the number of spindle poles, leading to multinucleation and delaying mitosis, and reversine inducing mitotic slippage and decreasing the duration of mitosis. Here, we demonstrated that an alternative optimized protocol improved chromosome transfer efficiency into various cell lines. These data advance chromosomal engineering technology and the use of human artificial chromosomes in genetic and regenerative medical research.
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Affiliation(s)
- Narumi Uno
- Laboratory of Bioengineering, Faculty of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Hiroyuki Satofuka
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Hitomaru Miyamoto
- Department of Chromosome Biomedical Engineering, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Kazuhisa Honma
- Department of Chromosome Biomedical Engineering, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Teruhiko Suzuki
- Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Kyotaro Yamazaki
- Department of Chromosome Biomedical Engineering, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
- Chromosome Engineering Research Group, The Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
| | - Ryota Ito
- Laboratory of Bioengineering, Faculty of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Takashi Moriwaki
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
- Department of Chromosome Biomedical Engineering, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Shusei Hamamichi
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Kazuma Tomizuka
- Laboratory of Bioengineering, Faculty of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Mitsuo Oshimura
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
| | - Yasuhiro Kazuki
- Chromosome Engineering Research Center, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
- Department of Chromosome Biomedical Engineering, School of Life Science, Faculty of Medicine, Tottori University, 86 Nishi-cho, Yonago, Tottori 683-8503, Japan
- Chromosome Engineering Research Group, The Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan
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Goto K, Osaki M, Izutsu R, Tanaka H, Sasaki R, Tanio A, Satofuka H, Kazuki Y, Yamamoto M, Kugoh H, Ito H, Oshimura M, Fujiwara Y, Okada F. Establishment of an antibody specific for AMIGO2 improves immunohistochemical evaluation of liver metastases and clinical outcomes in patients with colorectal cancer. Diagn Pathol 2022; 17:16. [PMID: 35094710 PMCID: PMC8802484 DOI: 10.1186/s13000-021-01176-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/26/2021] [Indexed: 12/11/2022] Open
Abstract
Abstract
Instruction
The human amphoterin-induced gene and open reading frame (AMIGO) was identified as a novel cell adhesion molecule of type I transmembrane protein. AMIGO2 is one of three members of the AMIGO family (AMIGO1, 2, and 3), and the similarity between them is approximately 40% at the amino acid level. We have previously shown that AMIGO2 functions as a driver of liver metastasis. Immunohistochemical analysis of AMIGO2 expression in colorectal cancer (CRC) using a commercially available anti-AMIGO2 mouse monoclonal antibody clone sc-373699 (sc mAb) correlated with liver metastasis and poor prognosis. However, the sc mAb was found to be cross-reactive with all three molecules in the AMIGO family.
Methods
We generated a rat monoclonal antibody clone rTNK1A0012 (rTNK mAb) for human AMIGO2. The rTNK mAb was used to re-evaluate the association between AMIGO2 expression and liver metastases/clinical outcomes using the same CRC tissue samples previously reported with sc mAb.
Results
Western blot analysis revealed that a rTNK mAb was identified as being specific for AMIGO2 protein and did not cross-react with AMIGO1 and AMIGO3. The rTNK mAb and sc mAb showed higher AMIGO2 expression, which correlates with a high frequency of liver metastases (65.3% and 47.5%, respectively), while multivariate analysis showed that AMIGO2 expression was an independent prognostic factor for liver metastases (p = 7.930E-10 and p = 1.707E-5). The Kaplan-Meier analyses showed that the rTNK mAb (p = 0.004), but not sc mAb (p = 0.107), predicted worse overall survival in patients with high AMIGO2 expression. The relationship between AMIGO2 expression and poor disease-specific survival showed a higher level of significance for rTNK mAb (p = 0.00004) compared to sc mAb (p = 0.001).
Conclusions
These results indicate that the developed rTNK1A0012 mAb is an antibody that specifically recognizes AMIGO2 by immunohistochemistry and can be a more reliable and applicable method for the diagnostic detection of liver metastases and worse prognosis in patients with high AMIGO2-expressing CRC.
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Onodera T, Kita S, Adachi Y, Moriyama S, Sato A, Nomura T, Sakakibara S, Inoue T, Tadokoro T, Anraku Y, Yumoto K, Tian C, Fukuhara H, Sasaki M, Orba Y, Shiwa N, Iwata N, Nagata N, Suzuki T, Sasaki J, Sekizuka T, Tonouchi K, Sun L, Fukushi S, Satofuka H, Kazuki Y, Oshimura M, Kurosaki T, Kuroda M, Matsuura Y, Suzuki T, Sawa H, Hashiguchi T, Maenaka K, Takahashi Y. A SARS-CoV-2 antibody broadly neutralizes SARS-related coronaviruses and variants by coordinated recognition of a virus-vulnerable site. Immunity 2021; 54:2385-2398.e10. [PMID: 34508662 PMCID: PMC8382582 DOI: 10.1016/j.immuni.2021.08.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/02/2021] [Accepted: 08/19/2021] [Indexed: 11/23/2022]
Abstract
Potent neutralizing SARS-CoV-2 antibodies often target the spike protein receptor-binding site (RBS), but the variability of RBS epitopes hampers broad neutralization of multiple sarbecoviruses and drifted viruses. Here, using humanized mice, we identified an RBS antibody with a germline VH gene that potently neutralized SARS-related coronaviruses, including SARS-CoV and SARS-CoV-2 variants. X-ray crystallography revealed coordinated recognition by the heavy chain of non-RBS conserved sites and the light chain of RBS with a binding angle mimicking the angiotensin-converting enzyme 2 (ACE2) receptor. The minimum footprints in the hypervariable region of RBS contributed to the breadth of neutralization, which was enhanced by immunoglobulin G3 (IgG3) class switching. The coordinated binding resulted in broad neutralization of SARS-CoV and emerging SARS-CoV-2 variants of concern. Low-dose therapeutic antibody treatment in hamsters reduced the virus titers and morbidity during SARS-CoV-2 challenge. The structural basis for broad neutralizing activity may inform the design of a broad spectrum of therapeutics and vaccines.
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Affiliation(s)
- Taishi Onodera
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Shunsuke Kita
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Yu Adachi
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Saya Moriyama
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Akihiko Sato
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan; Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Osaka 561-0825, Japan
| | - Takao Nomura
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Shuhei Sakakibara
- Laboratory of Immune Regulation, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Takeshi Inoue
- Laboratory of Lymphocyte Differentiation, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Takashi Tadokoro
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Yuki Anraku
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Kohei Yumoto
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Cong Tian
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
| | - Hideo Fukuhara
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan; Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Sapporo 060-0812, Japan
| | - Michihito Sasaki
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
| | - Yasuko Orba
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
| | - Nozomi Shiwa
- Department of Pathology, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Naoko Iwata
- Department of Pathology, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Noriyo Nagata
- Department of Pathology, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Tateki Suzuki
- Department of Virology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan
| | - Jiei Sasaki
- Department of Virology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan
| | - Tsuyoshi Sekizuka
- Pathogen Genomic Center, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Keisuke Tonouchi
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo 162-8640, Japan; Department of Life Science and Medical Bioscience, Waseda University, Tokyo 162-8480, Japan
| | - Lin Sun
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Shuetsu Fukushi
- Department of Virology I, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Hiroyuki Satofuka
- Chromosome Engineering Research Center, Tottori University, Tottori 683-8503, Japan
| | - Yasuhiro Kazuki
- Chromosome Engineering Research Center, Tottori University, Tottori 683-8503, Japan; Division of Genome and Cellular Functions, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, Tottori 683-8503, Japan
| | | | - Tomohiro Kurosaki
- Laboratory of Lymphocyte Differentiation, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Makoto Kuroda
- Pathogen Genomic Center, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Yoshiharu Matsuura
- Laboratory of Virus Control, Center for Infectious Diseases Education and Research, Osaka University, Osaka 565-0871, Japan
| | - Tadaki Suzuki
- Department of Pathology, National Institute of Infectious Diseases, Tokyo 208-0011, Japan
| | - Hirofumi Sawa
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0020, Japan
| | - Takao Hashiguchi
- Department of Virology, Faculty of Medicine, Kyushu University, Fukuoka 812-8582, Japan; Laboratory of Medical Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Katsumi Maenaka
- Laboratory of Biomolecular Science, and Center for Research and Education on Drug Discovery, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan; Global Station for Biosurfaces and Drug Discovery, Hokkaido University, Sapporo 060-0812, Japan.
| | - Yoshimasa Takahashi
- Research Center for Drug and Vaccine Development, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
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Satofuka H, Okabe Y, Takano Y, Utsugi T, Ohtsu M, Murakami Y. Immunization method for multi-pass membrane proteins using highly metastatic cell lines. Biochem Biophys Res Commun 2014; 450:99-104. [PMID: 24866236 DOI: 10.1016/j.bbrc.2014.05.065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 05/17/2014] [Indexed: 01/28/2023]
Abstract
A novel method using metastatic breast cancer cell lines was established for producing monoclonal antibodies (mAbs) against multi-span membrane proteins. Grafting of metastatic cells (MCF7-14) into the mammary gland of BALB/cJ/nu/nu mice induced splenic hypertrophy (1.6-3.0×10(8)cells/spleen [n=6]). More than half of the mAbs against MCF7-14 cells reacted with the cell membrane. Inducing production of antibodies against the extracellular domain of multi-pass membrane proteins is difficult. Because the protein structure becomes more complex as the number of transmembrane domains increases, preparing antigens for immunization in which the original structure is maintained is challenging. Using highly metastatic MDA-MB231 cells as the host cell line, we produced mAbs against a 12 transmembrane protein, solute carrier family 6 member 6 (SLC6A6), as a model antigen. When SLC6A6-overexpressing MDA-MB231 cells were grafted into nude mice, the number of splenocytes increased to 2.7-11.4×10(8)cells/spleen (n=10). Seven mAb-producing clones that not only recognized the extracellular domain of SLC6A6 but also were of the IgG subclass were obtained. Immunocytochemistry and flow cytometry analyses revealed that these mAbs recognized the native form of the extracellular domain of SLC6A6 on the cell surface. Our novel immunization method involving highly metastatic cells could be used to develop therapeutic mAbs against other multi-pass membrane proteins.
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Affiliation(s)
- Hiroyuki Satofuka
- Research and Development Division, Order-made Medical Research Inc., A-18 Green House, 2639 Yamazaki, Noda, Chiba 278-0022, Japan
| | - Yoko Okabe
- Research and Development Division, Order-made Medical Research Inc., A-18 Green House, 2639 Yamazaki, Noda, Chiba 278-0022, Japan
| | - Yuki Takano
- Department of Biological Science and Technology, Graduate School of Industrial Science and Technology, Tokyo University of Science, 3-1, Niijyuku 6-chome, Katsushika-ku, Tokyo 125-8585, Japan
| | - Takahiko Utsugi
- Research and Development Division, Order-made Medical Research Inc., A-18 Green House, 2639 Yamazaki, Noda, Chiba 278-0022, Japan
| | - Masaya Ohtsu
- Department of Biological Science and Technology, Graduate School of Industrial Science and Technology, Tokyo University of Science, 3-1, Niijyuku 6-chome, Katsushika-ku, Tokyo 125-8585, Japan
| | - Yasufumi Murakami
- Research and Development Division, Order-made Medical Research Inc., A-18 Green House, 2639 Yamazaki, Noda, Chiba 278-0022, Japan; Department of Biological Science and Technology, Graduate School of Industrial Science and Technology, Tokyo University of Science, 3-1, Niijyuku 6-chome, Katsushika-ku, Tokyo 125-8585, Japan.
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Uchino M, Kojima H, Wada K, Imada M, Onoda F, Satofuka H, Utsugi T, Murakami Y. Nuclear beta-catenin and CD44 upregulation characterize invasive cell populations in non-aggressive MCF-7 breast cancer cells. BMC Cancer 2010; 10:414. [PMID: 20696077 PMCID: PMC3087322 DOI: 10.1186/1471-2407-10-414] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 08/10/2010] [Indexed: 01/18/2023] Open
Abstract
Background In breast cancer cells, the metastatic cell state is strongly correlated to epithelial-to-mesenchymal transition (EMT) and the CD44+/CD24- stem cell phenotype. However, the MCF-7 cell line, which has a luminal epithelial-like phenotype and lacks a CD44+/CD24- subpopulation, has rare cell populations with higher Matrigel invasive ability. Thus, what are the potentially important differences between invasive and non-invasive breast cancer cells, and are the differences related to EMT or CD44/CD24 expression? Methods Throughout the sequential selection process using Matrigel, we obtained MCF-7-14 cells of opposite migratory and invasive capabilities from MCF-7 cells. Comparative analysis of epithelial and mesenchymal marker expression was performed between parental MCF-7, selected MCF-7-14, and aggressive mesenchymal MDA-MB-231 cells. Furthermore, using microarray expression profiles of these cells, we selected differentially expressed genes for their invasive potential, and performed pathway and network analysis to identify a set of interesting genes, which were evaluated by RT-PCR, flow cytometry or function-blocking antibody treatment. Results MCF-7-14 cells had enhanced migratory and invasive ability compared with MCF-7 cells. Although MCF-7-14 cells, similar to MCF-7 cells, expressed E-cadherin but neither vimentin nor fibronectin, β-catenin was expressed not only on the cell membrane but also in the nucleus. Furthermore, using gene expression profiles of MCF-7, MCF-7-14 and MDA-MB-231 cells, we demonstrated that MCF-7-14 cells have alterations in signaling pathways regulating cell migration and identified a set of genes (PIK3R1, SOCS2, BMP7, CD44 and CD24). Interestingly, MCF-7-14 and its invasive clone CL6 cells displayed increased CD44 expression and downregulated CD24 expression compared with MCF-7 cells. Anti-CD44 antibody treatment significantly decreased cell migration and invasion in both MCF-7-14 and MCF-7-14 CL6 cells as well as MDA-MB-231 cells. Conclusions MCF-7-14 cells are a novel model for breast cancer metastasis without requiring constitutive EMT and are categorized as a "metastable phenotype", which can be distinguished from both epithelial and mesenchymal cells. The alterations and characteristics of MCF-7-14 cells, especially nuclear β-catenin and CD44 upregulation, may characterize invasive cell populations in breast cancer.
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Affiliation(s)
- Masahiro Uchino
- Neo-Technology Development Division, Bio Matrix Research Inc., 105 Higashifukai, Nagareyama, Chiba 270-0101, Japan.
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Takagi M, Satofuka H, Amano S, Mizuno H, Eguchi Y, Hirata K, Miyamoto K, Fukui K, Imanaka T. Cellular toxicity of cadmium ions and their detoxification by heavy metal-specific plant peptides, phytochelatins, expressed in Mammalian cells. J Biochem 2002; 131:233-9. [PMID: 11820937 DOI: 10.1093/oxfordjournals.jbchem.a003093] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The apoptotic cell death of Jurkat cells due to Cd(2+) toxicity was studied by fluorescence microscopic observation and DNA fragmentation assaying. It was suggested that the apoptotic response to Cd(2+) was less clear than that to a typical apoptosis inducer, ultraviolet light (254 nm). Examination of MAP kinase phosphorylation (p38, JNKs, and c-Jun) due to Cd(2+) toxicity indicated that the phosphorylation was very slowly activated (4 h after stimulation), while UV light could activate the phosphorylation immediately. Therefore, it was suggested that Cd(2+) may not be a typical apoptosis inducer. Antioxidants [glutathione (GSH) and N-acetylcysteine (NAC)] could detoxify Cd(2+), indicating that the toxicity is a kind of oxidative stress. The detoxification effect of antioxidants showed cooperation with Bcl-2, suggesting that Cd(2+)-treatment causes diversified toxic signals including oxidative stress. On the addition of a plant-specific peptide, phytochelatin [PC(7), (gammaGlu-Cys)(7)-Gly], to the medium, the detoxification of Cd(2+) and cooperation with Bcl-2 were more intense than in the cases of GSH and NAC. Using an appropriate vector, a PC synthase gene was transferred from Arabidopsis thaliana to the Jurkat cell. The transfectant exhibited resistance to Cd(2+) and production of plant-specific PC (PC(2-6)).
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Affiliation(s)
- Masahiro Takagi
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Tatsunokuchi, Ishikawa 923-1292, Japan
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Abstract
Phytochelatins (PCs, (gamma Glu-Cys)(n)-Gly, n=2-11) are produced by higher plants, algae and some fungi in order to detoxify Cd(2+) by sequestration to form Cd-PCs complexes. In order to investigate what chemical structures of PCs are responsible for their metal-binding ability, various cysteine-rich peptides ((X-Cys)(7)-Gly, X=Glu, Asp, Lys, Gly, Ser and Gln) were chemically synthesized. Water-solubility, metal-binding property, and detoxification effect toward Cd(2+) were analyzed and compared with those of (gamma EC)(7)G. (SC)(7)G and (QC)(7)G were insoluble at pH below 10, and (GC)(7)G was not soluble at any pH between 1 and 12, indicating that charged side chains were at least required for the molecules to be solubilized in aqueous solution. By spectroscopic analyses using DTNB method and UV method, we found that (EC)(7)G and (DC)(7)G had almost equivalent abilities of Cd(2+)-binding as PC ((gamma EC)(7)G), indicating that the distance between each thiol group was not a major factor for the binding to Cd(2+). (beta DC)(7)G and (KC)(7)G interacted to Cd(2+) with fourth coordination as in the case of other soluble PC-related peptides. However, compared to (gamma EC)(7)G, (beta DC)(7)G displayed a slightly weaker binding to Cd(2+), and (KC)(7)G showed a drastic decrease in binding ability. The affinities of PC-related peptides toward Cd(2+) were evaluated as below; (gamma EC)(7)G=(EC)(7)G=(DC)(7)G>(beta DC)(7)G>>(KC)(7)G=weak binding. The results of Cd(2+)-detoxification assays were consistent with the affinity between Cd(2+) and the peptides. We concluded that the structure consisting of thiol and carboxyl groups were essential for the formation of a tight Cd-peptides complex such as Cd-PCs.
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Affiliation(s)
- H Satofuka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
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Satofuka H, Amano S, Atomi H, Takagi M, Hirata K, Miyamoto K, Imanaka T. Rapid method for detection and detoxification of heavy metal ions in water environments using phytochelation. J Biosci Bioeng 1999; 88:287-92. [PMID: 16232613 DOI: 10.1016/s1389-1723(00)80011-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/1999] [Accepted: 06/16/1999] [Indexed: 10/18/2022]
Abstract
Phytochelatins (PCs, (gammaGlu-Cys)n-Gly (n = 2-11)) are produced by higher plants, algae, and some fungi in response to heavy metal ion exposure. A rapid and convenient method for quantifying heavy metal ion concentrations in water environments was developed using a chemically synthesized PC as a mediator. The chelating ability of the PC and quantification of the thiol group were utilized to measure heavy metal ions at low concentrations. The method requires only ten minutes for measurement and only 1 ml of a liquid sample. A range of homogeneous PCs (n = 4-7) were chemically synthesized using a peptide synthesizer. These, especially PC7, exhibited higher sensitivity and consistency of measurement than the native PC from Silene cucubalus, which produced a mixture of PC2, PC3, and PC4. Detoxification of heavy metal ions in vitro by PC was also investigated. Using the paper disc method, the cell growth inhibition zone caused by cadmium ion against Salmonella typhimurium TA1538 was significantly decreased by addition of PC. Furthermore, at the minimum inhibitory concentration of cadmium ion (200 microM) in a nutrient broth culture of S. typhimurium, cell growth was almost completely recovered by addition of PC to the medium.
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Affiliation(s)
- H Satofuka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
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