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Ohtsuka H, Kawai S, Otsubo Y, Shimasaki T, Yamashita A, Aiba H. Metarhizium robertsii COH1 functionally complements Schizosaccharomyces pombe Ecl family proteins. J GEN APPL MICROBIOL 2024; 69:335-338. [PMID: 37813640 DOI: 10.2323/jgam.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
The fission yeast Schizosaccharomyces pombe ecl family genes respond to various starvation signals and induce appropriate intracellular responses, including the extension of chronological lifespan and induction of sexual differentiation. Herein, we propose that the colonization of hemocoel 1 (COH1) protein of Metarhizium robertsii, an insect-pathogenic fungus, is a functional homolog of S. pombe Ecl1 family proteins.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Sawa Kawai
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Yoko Otsubo
- Interdisciplinary Research Unit, National Institute for Basic Biology
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Akira Yamashita
- Interdisciplinary Research Unit, National Institute for Basic Biology
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University
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2
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Ohtsuka H, Shimasaki T, Aiba H. Low-Molecular Weight Compounds that Extend the Chronological Lifespan of Yeasts, Saccharomyces cerevisiae, and Schizosaccharomyces pombe. Adv Biol (Weinh) 2024; 8:e2400138. [PMID: 38616173 DOI: 10.1002/adbi.202400138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/04/2024] [Indexed: 04/16/2024]
Abstract
Yeast is an excellent model organism for research for regulating aging and lifespan, and the studies have made many contributions to date, including identifying various factors and signaling pathways related to aging and lifespan. More than 20 years have passed since molecular biological perspectives are adopted in this research field, and intracellular factors and signal pathways that control aging and lifespan have evolutionarily conserved from yeast to mammals. Furthermore, these findings have been applied to control the aging and lifespan of various model organisms by adjustment of the nutritional environment, genetic manipulation, and drug treatment using low-molecular weight compounds. Among these, drug treatment is easier than the other methods, and research into drugs that regulate aging and lifespan is consequently expected to become more active. Chronological lifespan, a definition of yeast lifespan, refers to the survival period of a cell population under nondividing conditions. Herein, low-molecular weight compounds are summarized that extend the chronological lifespan of Saccharomyces cerevisiae and Schizosaccharomyces pombe, along with their intracellular functions. The low-molecular weight compounds are also discussed that extend the lifespan of other model organisms. Compounds that have so far only been studied in yeast may soon extend lifespan in other organisms.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
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3
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Maekawa Y, Matsui K, Okamoto K, Shimasaki T, Ohtsuka H, Tani M, Ihara K, Aiba H. Identification of plb1 mutation that extends longevity via activating Sty1 MAPK in Schizosaccharomyces pombe. Mol Genet Genomics 2024; 299:20. [PMID: 38424265 DOI: 10.1007/s00438-024-02107-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 12/04/2023] [Indexed: 03/02/2024]
Abstract
To understand the lifespan of higher organisms, including humans, it is important to understand lifespan at the cellular level as a prerequisite. So, fission yeast is a good model organism for the study of lifespan. To identify the novel factors involved in longevity, we are conducting a large-scale screening of long-lived mutant strains that extend chronological lifespan (cell survival in the stationary phase) using fission yeast. One of the newly acquired long-lived mutant strains (No.98 mutant) was selected for analysis and found that the long-lived phenotype was due to a missense mutation (92Phe → Ile) in the plb1+ gene. plb1+ gene in fission yeast is a nonessential gene encoding a homolog of phospholipase B, but its functions under normal growth conditions, as well as phospholipase B activity, remain unresolved. Our analysis of the No.98 mutant revealed that the plb1 mutation reduces the integrity of the cellular membrane and cell wall and activates Sty1 via phosphorylation.
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Affiliation(s)
- Yasukichi Maekawa
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Kotaro Matsui
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Keisuke Okamoto
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Motohiro Tani
- Department of Chemistry, Faculty of Sciences, Kyushu University, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan.
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4
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Ohtsuka H, Otsubo Y, Shimasaki T, Yamashita A, Aiba H. ecl family genes: Factors linking starvation and lifespan extension in Schizosaccharomyces pombe. Mol Microbiol 2023; 120:645-657. [PMID: 37525511 DOI: 10.1111/mmi.15134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
In the fission yeast Schizosaccharomyces pombe, the duration of survival in the stationary phase, termed the chronological lifespan (CLS), is affected by various environmental factors and the corresponding gene activities. The ecl family genes were identified in the genomic region encoding non-coding RNA as positive regulators of CLS in S. pombe, and subsequently shown to encode relatively short proteins. Several studies revealed that ecl family genes respond to various nutritional starvation conditions via different mechanisms, and they are additionally involved in stress resistance, autophagy, sexual differentiation, and cell cycle control. Recent studies reported that Ecl family proteins strongly suppress target of rapamycin complex 1, which is a conserved eukaryotic nutrient-sensing kinase complex that also regulates longevity in a variety of organisms. In this review, we introduce the regulatory mechanisms of Ecl family proteins and discuss their emerging findings.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Yoko Otsubo
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Akira Yamashita
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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5
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Ohtsuka H, Sakata H, Kitazaki Y, Tada M, Shimasaki T, Otsubo Y, Maekawa Y, Kobayashi M, Imada K, Yamashita A, Aiba H. The ecl family gene ecl3+ is induced by phosphate starvation and contributes to sexual differentiation in fission yeast. J Cell Sci 2023; 136:287015. [PMID: 36779416 PMCID: PMC10038150 DOI: 10.1242/jcs.260759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 02/07/2023] [Indexed: 02/14/2023] Open
Abstract
In Schizosaccharomyces pombe, ecl family genes are induced by several signals, such as starvation of various nutrients, including sulfur, amino acids and Mg2+, and environmental stress, including heat or oxidative stress. These genes mediate appropriate cellular responses and contribute to the maintenance of cell viability and induction of sexual differentiation. Although this yeast has three ecl family genes with overlapping functions, any environmental conditions that induce ecl3+ remain unidentified. We demonstrate that ecl3+ is induced by phosphate starvation, similar to its chromosomally neighboring genes, pho1+ and pho84+, which respectively encode an extracellular acid phosphatase and an inorganic phosphate transporter. ecl3+ expression was induced by the transcription factor Pho7 and affected by the cyclin-dependent kinase (CDK)-activating kinase Csk1. Phosphate starvation induced G1 arrest and sexual differentiation via ecl family genes. Biochemical analyses suggested that this G1 arrest was mediated by the stabilization of the CDK inhibitor Rum1, which was dependent on ecl family genes. This study shows that ecl family genes are required for appropriate responses to phosphate starvation and provides novel insights into the diversity and similarity of starvation responses.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Hiroki Sakata
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Yuto Kitazaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Masanobu Tada
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Yoko Otsubo
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Aichi 444-858, Japan
- National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
- Center for Novel Science Initiatives, National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan
| | - Yasukichi Maekawa
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Mikuto Kobayashi
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Kazuki Imada
- Department of Chemistry and Biochemistry, National Institute of Technology (KOSEN), Suzuka College, Suzuka 510-0294, Japan
- Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Akira Yamashita
- Interdisciplinary Research Unit, National Institute for Basic Biology, Okazaki, Aichi 444-858, Japan
- Center for Low-temperature Plasma Sciences, Nagoya University, Nagoya, Aichi 464-8603, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
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6
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Maruyama T, Hayashi K, Matsui K, Maekawa Y, Shimasaki T, Ohtsuka H, Shigeaki S, Aiba H. Characterization of hexose transporter genes in the views of the chronological life span and glucose uptake in fission yeast. J GEN APPL MICROBIOL 2023; 68:270-277. [PMID: 35781263 DOI: 10.2323/jgam.2022.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Fission yeast, Schizosaccharomyces pombe, possesses eight hexose transporters, Ght1~8. In order to clarify the role of each hexose transporter on glucose uptake, a glucose uptake assay system was established and the actual glucose uptake activity of each hexose transporter-deletion mutant was measured. Under normal growth condition containing 2% glucose, ∆ght5 and ∆ght2 mutants showed large and small decrease in glucose uptake activity, respectively. On the other hand, the other deletion mutants did not show any decrease in glucose uptake activity indicating that, in the presence of Ght5 and Ght2, the other hexose transporters do not play a significant role in glucose uptake. To understand the relevance between glucose uptake and lifespan regulation, we measured the chronological lifespan of each hexose transporter deletion mutant, and found that only ∆ght5 mutant showed a significant lifespan extension. Based on these results we showed that Ght5 is mainly involved in the glucose uptake in Schizosaccharomyces pombe, and suggested that the ∆ght5 mutant has prolonged lifespan due to physiological changes similar to calorie restriction.
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Affiliation(s)
- Teppei Maruyama
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Kanako Hayashi
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Kotaro Matsui
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Yasukichi Maekawa
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
| | | | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University
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7
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Ohtsuka H, Imada K, Shimasaki T, Aiba H. Sporulation: A response to starvation in the fission yeast Schizosaccharomyces pombe. Microbiologyopen 2022; 11:e1303. [PMID: 35765188 PMCID: PMC9214231 DOI: 10.1002/mbo3.1303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/08/2022] [Accepted: 06/08/2022] [Indexed: 12/02/2022] Open
Abstract
The fission yeast Schizosaccharomyces pombe employs two main strategies to adapt to the environment and survive when starved for nutrients. The strategies employ sporulation via sexual differentiation and extension of the chronological lifespan. When a cell is exposed to nutrient starvation in the presence of a cell of the opposite sex, the cells undergo fusion through conjugation and sporulation through meiosis. S. pombe spores are highly resistant to diverse stresses and may survive for a very long time. In this minireview, among the various sexual differentiation processes induced by starvation, we focused on and summarized the findings of the molecular mechanisms of spore formation in fission yeast. Furthermore, comparative measurements of the chronological lifespan of stationary phase cells and G0 cells and the survival period of spore cells revealed that the spore cells survived for a long period, indicating the presence of an effective mechanism for survival. Currently, many molecules involved in sporulation and their functions are being discovered; however, our understanding of these is not complete. Further understanding of spores may not only deepen our comprehension of sexual differentiation but may also provide hints for sustaining life.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Kazuki Imada
- Department of Chemistry and Biochemistry, National Institute of Technology (KOSEN), Suzuka College, Suzuka, Japan.,Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
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8
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Ohtsuka H, Matsumoto T, Mochida T, Shimasaki T, Shibuya M, Yamamoto Y, Aiba H. Tschimganine has different targets for chronological lifespan extension and growth inhibition in fission yeast. Biosci Biotechnol Biochem 2022; 86:775-779. [PMID: 35416247 DOI: 10.1093/bbb/zbac051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/19/2022] [Accepted: 03/25/2022] [Indexed: 11/14/2022]
Abstract
Tschimganine inhibits growth and extends the chronological lifespan in Schizosaccharomyces pombe. We synthesized a Tschimganine analog, Mochimganine, which extends the lifespan similar to Tschimganine but exhibits a significantly weaker growth inhibition effect. Based on the comparative analysis of these compounds, we propose that Tschimganine has at least 2 targets: one extends the lifespan and the other inhibits growth.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Takuma Matsumoto
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Takahiro Mochida
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
| | - Masatoshi Shibuya
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Yoshihiko Yamamoto
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Aichi, Japan
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9
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Ohtsuka H, Shimasaki T, Aiba H. Response to leucine in Schizosaccharomyces pombe (fission yeast). FEMS Yeast Res 2022; 22:6553821. [PMID: 35325114 PMCID: PMC9041340 DOI: 10.1093/femsyr/foac020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/08/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Leucine (Leu) is a branched-chain, essential amino acid in animals, including humans. Fungi, including the fission yeast Schizosaccharomyces pombe, can biosynthesize Leu, but deletion of any of the genes in this biosynthesis leads to Leu auxotrophy. In this yeast, although a mutation in the Leu biosynthetic pathway, leu1-32, is clearly inconvenient for this species, it has increased its usefulness as a model organism in laboratories worldwide. Leu auxotrophy produces intracellular responses and phenotypes different from those of the prototrophic strains, depending on the growing environment, which necessitates a certain degree of caution in the analysis and interpretation of the experimental results. Under amino acid starvation, the amino acid-auxotrophic yeast induces cellular responses, which are conserved in higher organisms without the ability of synthesizing amino acids. This mini-review focuses on the roles of Leu in S. pombe and discusses biosynthetic pathways, contribution to experimental convenience using a plasmid specific for Leu auxotrophic yeast, signaling pathways, and phenotypes caused by Leu starvation. An accurate understanding of the intracellular responses brought about by Leu auxotrophy can contribute to research in various fields using this model organism and to the understanding of intracellular responses in higher organisms that cannot synthesize Leu.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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10
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Matsui K, Okamoto K, Hasegawa T, Ohtsuka H, Shimasaki T, Ihara K, Goto Y, Aoki K, Aiba H. Identification of ksg1 mutation showing long-lived phenotype in fission yeast. Genes Cells 2021; 26:967-978. [PMID: 34534388 DOI: 10.1111/gtc.12897] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/03/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/19/2022]
Abstract
Fission yeast is a good model organism for the study of lifespan. To elucidate the mechanism, we screened for long-lived mutants. We found a nonsense mutation in the ksg1+ gene, which encodes an ortholog of mammalian PDK1 (phosphoinositide-dependent protein kinase). The mutation was in the PH domain of Ksg1 and caused defect in membrane localization and protein stability. Analysis of the ksg1 mutant revealed that the reduced amounts and/or activity of the Ksg1 protein are responsible for the increased lifespan. Ksg1 is essential for growth and known to phosphorylate multiple substrates, but the substrate responsible for the long-lived phenotype of ksg1 mutation is not yet known. Genetic analysis showed that deletion of pck2 suppressed the long-lived phenotype of ksg1 mutant, suggesting that Pck2 might be involved in the lifespan extension caused by ksg1 mutation.
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Affiliation(s)
- Kotaro Matsui
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Keisuke Okamoto
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Tomoka Hasegawa
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | - Yuhei Goto
- Division of Quantitative Biology, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Aichi, Japan.,Quantitative Biology Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi, Japan.,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Aichi, Japan
| | - Kazuhiro Aoki
- Division of Quantitative Biology, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Aichi, Japan.,Quantitative Biology Research Group, Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi, Japan.,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Aichi, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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Abstract
Sulfur is an essential component of various biologically important molecules, including methionine, cysteine and glutathione, and it is also involved in coping with oxidative and heavy metal stress. Studies using model organisms, including budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe), have contributed not only to understanding various cellular processes but also to understanding the utilization and response mechanisms of each nutrient, including sulfur. Although fission yeast can use sulfate as a sulfur source, its sulfur metabolism pathway is slightly different from that of budding yeast because it does not have a trans-sulfuration pathway. In recent years, it has been found that sulfur starvation causes various cellular responses in S. pombe, including sporulation, cell cycle arrest at G2, chronological lifespan extension, autophagy induction and reduced translation. This MiniReview identifies two sulfate transporters in S. pombe, Sul1 (encoded by SPBC3H7.02) and Sul2 (encoded by SPAC869.05c), and summarizes the metabolic pathways of sulfur assimilation and cellular response to sulfur starvation. Understanding these responses, including metabolism and adaptation, will contribute to a better understanding of the various stress and nutrient starvation responses and chronological lifespan regulation caused by sulfur starvation.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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12
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Kurauchi T, Matsui K, Shimasaki T, Ohtsuka H, Tsubouchi S, Ihara K, Tani M, Aiba H. Identification of sur2 mutation affecting the lifespan of fission yeast. FEMS Microbiol Lett 2021; 368:6296417. [PMID: 34114004 DOI: 10.1093/femsle/fnab070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 04/16/2021] [Accepted: 06/09/2021] [Indexed: 11/14/2022] Open
Abstract
Yeast is a suitable model system to analyze the mechanism of lifespan. In this study, to identify novel factors involved in chronological lifespan, we isolated a mutant with a long chronological lifespan and found a missense mutation in the sur2+ gene, which encodes a homolog of Saccharomyces cerevisiae sphingolipid C4-hydroxylase in fission yeast. Characterization of the mutant revealed that loss of sur2 function resulted in an extended chronological lifespan. The effect of caloric restriction, a well-known signal for extending lifespan, is thought to be dependent on the sur2+ gene.
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Affiliation(s)
- Tatsuhiro Kurauchi
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Kotaro Matsui
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Satoshi Tsubouchi
- Laboratory of Molecular Microbiology, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Motohiro Tani
- Department of Chemistry, Faculty of Sciences, Kyushu University, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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Ohtsuka H, Shimasaki T, Aiba H. Extension of chronological lifespan in Schizosaccharomyces pombe. Genes Cells 2021; 26:459-473. [PMID: 33977597 PMCID: PMC9290682 DOI: 10.1111/gtc.12854] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 01/08/2023]
Abstract
There are several examples in the nature wherein the mechanism of longevity control of unicellular organisms is evolutionarily conserved with that of higher multicellular organisms. The present microreview focuses on aging and longevity studies, particularly on chronological lifespan (CLS) concerning the unicellular eukaryotic fission yeast Schizosaccharomyces pombe. In S. pombe, >30 compounds, 8 types of nutrient restriction, and >80 genes that extend CLS have been reported. Several CLS control mechanisms are known to be involved in nutritional response, energy utilization, stress responses, translation, autophagy, and sexual differentiation. In unicellular organisms, the control of CLS is directly linked to the mechanism by which cells are maintained in limited‐resource environments, and their genetic information is left to posterity. We believe that this important mechanism may have been preserved as a lifespan control mechanism for higher organisms.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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Ohtsuka H, Kobayashi M, Shimasaki T, Sato T, Akanuma G, Kitaura Y, Otsubo Y, Yamashita A, Aiba H. Magnesium depletion extends fission yeast lifespan via general amino acid control activation. Microbiologyopen 2021; 10:e1176. [PMID: 33970532 PMCID: PMC8088111 DOI: 10.1002/mbo3.1176] [Citation(s) in RCA: 6] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/31/2022] Open
Abstract
Nutrients including glucose, nitrogen, sulfur, zinc, and iron are involved in the regulation of chronological lifespan (CLS) of yeast, which serves as a model of the lifespan of differentiated cells of higher organisms. Herein, we show that magnesium (Mg2+) depletion extends CLS of the fission yeast Schizosaccharomyces pombe through a mechanism involving the Ecl1 gene family. We discovered that ecl1+ expression, which extends CLS, responds to Mg2+ depletion. Therefore, we investigated the underlying intracellular responses. In amino acid auxotrophic strains, Mg2+ depletion robustly induces ecl1+ expression through the activation of the general amino acid control (GAAC) pathway—the equivalent of the amino acid response of mammals. Polysome analysis indicated that the expression of Ecl1 family genes was required for regulating ribosome amount when cells were starved, suggesting that Ecl1 family gene products control the abundance of ribosomes, which contributes to longevity through the activation of the evolutionarily conserved GAAC pathway. The present study extends our understanding of the cellular response to Mg2+ depletion and its influence on the mechanism controlling longevity.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Mikuto Kobayashi
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Teppei Sato
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Genki Akanuma
- Department of Life Science, College of Sciences, Rikkyo University, Tokyo, Japan.,Department of Life Science, Graduate School of Science, Gakushuin University, Tokyo, Japan
| | - Yasuyuki Kitaura
- Laboratory of Nutritional Biochemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yoko Otsubo
- Laboratory of Cell Responses, National Institute for Basic Biology, Okazaki, Japan.,National Institute for Fusion Science, Toki, Japan.,Center for Novel Science Initiatives, National Institutes of Natural Sciences, Okazaki, Japan
| | - Akira Yamashita
- Laboratory of Cell Responses, National Institute for Basic Biology, Okazaki, Japan.,Center for Novel Science Initiatives, National Institutes of Natural Sciences, Okazaki, Japan.,Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies, Okazaki, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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Shimasaki T, Okamoto K, Ohtsuka H, Aiba H. Sulfur depletion induces autophagy through Ecl1 family genes in fission yeast. Genes Cells 2020; 25:825-830. [PMID: 33064910 DOI: 10.1111/gtc.12815] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/09/2020] [Accepted: 10/09/2020] [Indexed: 11/28/2022]
Abstract
Autophagy is an intracellular degradation system widely conserved among various species. Autophagy is induced by the depletion of various nutrients, and this degradation mechanism is essential for adaptation to such conditions. In this study, we demonstrated that sulfur depletion induces autophagy in the fission yeast Schizosaccharomyces pombe. Based on the finding that autophagy induced by sulfur depletion was completely abolished in a mutant in which the ecl1, ecl2 and ecl3 genes were deleted (Δecls), we report that these three genes are essential for the induction of autophagy by sulfur depletion. Furthermore, autophagy-defective mutant cells exhibited poor growth and short lifespan (compared with wild-type cells) under the sulfur-depleted condition. These results indicated that the mechanism of autophagy is necessary for the appropriate adaptation to sulfur depletion.
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Affiliation(s)
- Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Keisuke Okamoto
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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Ohtsuka H, Shimasaki T, Aiba H. Genes affecting the extension of chronological lifespan in Schizosaccharomyces pombe (fission yeast). Mol Microbiol 2020; 115:623-642. [PMID: 33064911 PMCID: PMC8246873 DOI: 10.1111/mmi.14627] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/17/2020] [Accepted: 10/11/2020] [Indexed: 02/06/2023]
Abstract
So far, more than 70 genes involved in the chronological lifespan (CLS) of Schizosaccharomyces pombe (fission yeast) have been reported. In this mini‐review, we arrange and summarize these genes based on the reported genetic interactions between them and the physical interactions between their products. We describe the signal transduction pathways that affect CLS in S. pombe: target of rapamycin complex 1, cAMP‐dependent protein kinase, Sty1, and Pmk1 pathways have important functions in the regulation of CLS extension. Furthermore, the Php transcription complex, Ecl1 family proteins, cyclin Clg1, and the cyclin‐dependent kinase Pef1 are important for the regulation of CLS extension in S. pombe. Most of the known genes involved in CLS extension are related to these pathways and genes. In this review, we focus on the individual genes regulating CLS extension in S. pombe and discuss the interactions among them.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Nagoya, Japan
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Imai Y, Shimasaki T, Enokimura C, Ohtsuka H, Tsubouchi S, Ihara K, Aiba H. gas1 mutation extends chronological lifespan via Pmk1 and Sty1 MAPKs in Schizosaccharomyces pombe. Biosci Biotechnol Biochem 2019; 84:330-337. [PMID: 31601154 DOI: 10.1080/09168451.2019.1676695] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In the longevity research by using yeasts, chronological lifespan is defined as the survival time after entry into stationary phase. Previously, screening for long lived mutants of Schizosaccharomyces pombe was performed to identify the novel factors involved in longevity. From this screening, one long lived mutant called as No.36 was obtained. In this study, we identified the mutation caused in gas1+, which encodes glucanosyltransferase (gas1-287 mutation) is responsible for the longevity of No.36 mutant. Through the analysis of this mutant, we found that cell wall perturbing agent micafungin also extends chronological lifespan in fission yeast. This lifespan extension depended on both Pmk1 and Sty1 MAP kinases, and longevity caused by the gas1-287 mutation also depended on these kinases. In summary, we propose that the gas1-287 mutation causes longevity as the similar mechanism as cell wall stress depending on Pmk1 and Sty1 MAPK pathways.
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Affiliation(s)
- Yuki Imai
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Chihiro Enokimura
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Satoshi Tsubouchi
- Laboratory of Molecular Microbiology, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
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Ohtsuka H, Kato T, Sato T, Shimasaki T, Kojima T, Aiba H. Leucine depletion extends the lifespans of leucine-auxotrophic fission yeast by inducing Ecl1 family genes via the transcription factor Fil1. Mol Genet Genomics 2019; 294:1499-1509. [PMID: 31456006 DOI: 10.1007/s00438-019-01592-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [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: 03/17/2019] [Accepted: 06/28/2019] [Indexed: 11/30/2022]
Abstract
Many studies show that lifespans of various model organisms can be extended by limiting the quantities of nutrients that are necessary for proliferation. In Schizosaccharomyces pombe, the Ecl1 family genes have been associated with lifespan control and are necessary for cell responses to nutrient depletion, but their functions and mechanisms of action remain uncharacterized. Herein, we show that leucine depletion extends the chronological lifespan (CLS) of leucine-auxotrophic cells. Furthermore, depletion of leucine extended CLS and caused cell miniaturization and cell cycle arrest at the G1 phase, and all of these processes depended on Ecl1 family genes. Although depletion of leucine raises the expression of ecl1+ by about 100-fold in leucine-auxotrophic cells, these conditions did not affect ecl1+ expression in leucine-auxotrophic fil1 mutants that were isolated in deletion set screens using 79 mutants disrupting a transcription factor. Fil1 is a GATA-type zinc finger transcription factor that reportedly binds directly to the upstream regions of ecl1+ and ecl2+. Accordingly, we suggest that Ecl1 family genes are induced in response to environmental stresses, such as oxidative stress and heat stress, or by nutritional depletion of nitrogen or sulfur sources or the amino acid leucine. We also propose that these genes play important roles in the maintenance of cell survival until conditions that favor proliferation are restored.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takanori Kato
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Teppei Sato
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takaaki Kojima
- Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan.
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Hibi T, Ohtsuka H, Shimasaki T, Inui S, Shibuya M, Tatsukawa H, Kanie K, Yamamoto Y, Aiba H. Tschimganine and its derivatives extend the chronological life span of yeast via activation of the Sty1 pathway. Genes Cells 2018; 23:620-637. [PMID: 29900664 DOI: 10.1111/gtc.12604] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [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: 12/23/2017] [Revised: 05/01/2018] [Accepted: 05/15/2018] [Indexed: 12/13/2022]
Abstract
Most antiaging factors or life span extenders are associated with calorie restriction (CR). Very few of these factors function independently of, or additively with, CR. In this study, we focused on tschimganine, a compound that was reported to extend chronological life span (CLS). Although tschimganine led to the extension of CLS, it also inhibited yeast cell growth. We acquired a Schizosaccharomyces pombe mutant with a tolerance for tschimganine due to the gene crm1. The resulting Crm1 protein appears to export the stress-activated protein kinase Sty1 from the nucleus to the cytosol even under stressful conditions. Furthermore, we synthesized two derivative compounds of tschimganine, α-hibitakanine and β-hibitakanine; these derivatives did not inhibit cell growth, as seen with tschimganine. α-hibitakanine extended the CLS, not only in S. pombe but also in Saccharomyces cerevisiae, indicating the possibility that life span regulation by tschimganine derivative may be conserved across various yeast species. We found that the longevity induced by tschimganine was dependent on the Sty1 pathway. Based on our results, we propose that tschimganine and its derivatives extend CLS by activating the Sty1 pathway in fission yeast, and CR extends CLS via two distinct pathways, one Sty1-dependent and the other Sty1-independent. These findings provide the potential for creating an additive life span extension effect when combined with CR, as well as a better understanding of the mechanism of CLS.
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Affiliation(s)
- Takahide Hibi
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Shougo Inui
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Masatoshi Shibuya
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hideki Tatsukawa
- Laboratory of Cellular Biochemistry, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Kei Kanie
- Laboratory of Cell and Molecular Bioengineering, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Yoshihiko Yamamoto
- Laboratory of Molecular Design, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, Japan
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Ohtsuka H, Takinami M, Shimasaki T, Hibi T, Murakami H, Aiba H. Sulfur restriction extends fission yeast chronological lifespan through Ecl1 family genes by downregulation of ribosome. Mol Microbiol 2017; 105:84-97. [PMID: 28388826 DOI: 10.1111/mmi.13686] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 03/20/2017] [Accepted: 03/30/2017] [Indexed: 01/11/2023]
Abstract
Nutritional restrictions such as calorie restrictions are known to increase the lifespan of various organisms. Here, we found that a restriction of sulfur extended the chronological lifespan (CLS) of the fission yeast Schizosaccharomyces pombe. The restriction decreased cellular size, RNA content, and ribosomal proteins and increased sporulation rate. These responses depended on Ecl1 family genes, the overexpression of which results in the extension of CLS. We also showed that the Zip1 transcription factor results in the sulfur restriction-dependent expression of the ecl1+ gene. We demonstrated that a decrease in ribosomal activity results in the extension of CLS. Based on these observations, we propose that sulfur restriction extends CLS through Ecl1 family genes in a ribosomal activity-dependent manner.
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Affiliation(s)
- Hokuto Ohtsuka
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Masahiro Takinami
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takahide Hibi
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Hiroshi Murakami
- Department of Biological Science, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan
| | - Hirofumi Aiba
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
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Shimasaki T, Ohtsuka H, Naito C, Murakami H, Aiba H. Ecl1 is activated by the transcription factor Atf1 in response to H2O2 stress in Schizosaccharomyces pombe. Mol Genet Genomics 2014; 289:685-93. [PMID: 24696293 DOI: 10.1007/s00438-014-0845-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 03/21/2014] [Indexed: 11/29/2022]
Abstract
The Ecl1 family genes extend the lifespan of fission yeast when overexpressed. They also cause resistance against H(2)O(2) stress. In this study, we found that the bZip transcription factor Atf1 is a direct activator of the induction of extender of chronological lifespan (ecl1 (+)) by H(2)O(2) stress. Based on ChIP analysis, we identified that Atf1 binds to the upstream DNA region of ecl1(+). Previously, we reported that overexpression of ecl1(+) increased the expression of the catalase-encoding ctt1(+). This ecl1(+)-dependent increase of ctt1(+) expression occurred in ∆atf1 mutant. On the other hand, the activation of ctt1 (+) caused by the ∆pyp1 mutation, which enhances Sty1-Atf1 activity, could occur in ∆ecl1 mutant. Based on these results, we propose that Atf1 can regulate ctt1(+) in both an Ecl1-dependent and an Ecl1-independent manner.
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Affiliation(s)
- Takafumi Shimasaki
- Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Chikusa-ku, Nagoya, 464-8601, Japan
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Gotoh K, Masaki T, Chiba S, Ando H, Fujiwara K, Shimasaki T, Mitsutomi K, Katsuragi I, Kakuma T, Sakata T, Yoshimatsu H. Hypothalamic brain-derived neurotrophic factor regulates glucagon secretion mediated by pancreatic efferent nerves. J Neuroendocrinol 2013; 25:302-11. [PMID: 23157205 DOI: 10.1111/jne.12003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 10/18/2012] [Accepted: 11/10/2012] [Indexed: 01/10/2023]
Abstract
Understanding the molecular mechanism of the regulation of glucagon secretion is critical for treating the dysfunction of α cells observed in diabetes. Glucagon-like peptide (GLP)-1 analogues reduce plasma glucagon and are assumed to contribute to their action to lower blood glucose. It has previously been demonstrated that the central administration of brain-derived neurotrophic factor (BDNF) improves glucose metabolism by a mechanism independent of feeding behaviour in obese subjects. Using male rats, we examined whether BDNF influences glucagon secretion from α cells via the the central nervous system. We investigate whether: (i) the central infusion of BDNF stimulates glucagon and/or insulin secretion via the pancreatic efferent nerve from the hypothalamus; (ii) the intraportal infusion of GLP-1 regulates glucose metabolism via the central and peripheral nervous system; and (iii) BDNF receptor and/or BDNF-positive fibres are localised near α cells of islets. The portal glucagon level decreased with the central administration of BDNF (n = 6, in each; P < 0.05); in contrast, there was no significant change in portal insulin, peripheral glucagon and insulin levels with the same treatment. This reduction of glucagon secretion was abolished by pancreatic efferent denervation (n = 6, in each; P < 0.05). In an immunohistochemical study, pancreatic α cells were stained specifically with BDNF and tyrosine-related kinase B, a specific receptor for BDNF, and α cells were also co-localised with BDNF. Moreover, intraportal administration of GLP-1 decreased glucagon secretion, as well as blood glucose, whereas it increased the BDNF content in the pancreas; these effects were inhibited with the central infusion of BDNF antibody (n = 6, in each; P < 0.05). BDNF and GLP-1 affect glucose metabolism and modulate glucagon secretion from pancreatic α cells via the central and peripheral nervous systems.
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Affiliation(s)
- K Gotoh
- Department of Internal Medicine 1, Faculty of Medicine, Oita University, Yufu, Japan.
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Gotoh K, Inoue M, Masaki T, Chiba S, Shiraishi K, Shimasaki T, Matsuoka K, Ando H, Fujiwara K, Fukunaga N, Aoki K, Nawata T, Katsuragi I, Kakuma T, Seike M, Yoshimatsu H. Obesity-related chronic kidney disease is associated with spleen-derived IL-10. Nephrol Dial Transplant 2012; 28:1120-30. [DOI: 10.1093/ndt/gfs440] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Hokkoku K, Kitade H, Yoshimitsu Y, Okuda M, Mori M, Shintaku K, Shimasaki T. A Case of Colon Cancer with Chronic Renal Dysfunction Responding to Effective Retreatment with Folfiri. Ann Oncol 2012. [DOI: 10.1016/s0923-7534(20)32503-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Abstract
The DNA double strand breaks (DSBs) induced by X ray and carbon ion beam irradiation in scid cells were analysed using pulsed-field gel electrophoresis. Scid cells and hybrid cells were ideal to study the DNA DSB repair mechanisms, because their genetic backgrounds were identical except DNA-PK activity. Induction of DNA DSBs was determined after exposure to X rays and carbon beams. DNA DSB repair was by biphasic kinetics with a fast and a slow component. For scid cells only a slow component was observed, whereas the kinetics of DSBs repair was biphasic with a fast and a slow component. It was concluded from the experimental data that the induced DSB rejoining in scid cells was due to the lack of DNA-PK activity.
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Affiliation(s)
- T Shimasaki
- Research Centre for Isotope Science, Kumamoto University, 2-2-1 Honjo, 860-0811 Kumamoto, Japan.
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Ihara M, Suwa A, Komatsu K, Shimasaki T, Okaichi K, Hendrickson EA, Okumura Y. Heat sensitivity of double-stranded DNA-dependent protein kinase (DNA-PK) activity. Int J Radiat Biol 1999; 75:253-8. [PMID: 10072187 DOI: 10.1080/095530099140717] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [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: 02/04/2023]
Abstract
PURPOSE The heat sensitivity of DNA-PK activity in hybrid cells and the possible restoration of this activity with extracts from scid cells (defective in DNA-PKcs), sxi-3 cells (defective in Ku80) and V794 (sxi-3 parental wild-type cells) was analysed. MATERIALS AND METHODS Heat treatment of cells was performed in a water bath at 44 degrees C. The cell extract from scid cells or sxi-3 cells was added to heat-treated hybrid cell extracts, and the DNA-PK activity was assayed. RESULTS When hybrid cells were heated at 44 degrees C for 15 min, DNA-PK activity was reduced to undetectable levels. The decreased DNA-PK activity could be restored in a concentration-dependent manner with the addition of scid cell extract. The sxi-3 cell extract could not restore heat-inactivated DNA-PK activity. CONCLUSIONS DNA-PK was inactivated by heat treatment at 44 degrees C. Ku70/Ku80, but not Ku70 alone, could restore heat-inactivated DNA-PK.
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Affiliation(s)
- M Ihara
- Department of Radiation Biophysics, Atomic Bomb Disease Institute, Nagasaki University School of Medicine, Japan.
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Sugimoto T, Shimasaki T, Abe H, Orita H, Watanabe T, Washio M. [A case report on a reconstructive operation of a traumatic tricuspid regurgitation with a congenital defect of the left pericardium]. Nihon Kyobu Geka Gakkai Zasshi 1995; 43:1977-80. [PMID: 8551083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We reported a successful tricuspid valve replacement in a 58-years old man, who had easy fatiguability after 14 years of a blunt chest trauma. The preoperative examination revealed a marked cardiomegaly with deformation of both ventricles and grade 4 tricuspid regurgitation caused by the prolapse of the anterior leaflet. The operative inspection revealed a left pericardial defect with a diameter of 10 cm and a torn anterior papillary muscle. Since a usual plastic procedure did not improve the regurgitation, a Carpentier-Edward bioprosthetic valve was implanted in the supra annular position. Atrioventricular conduction was preserved. The tricuspid valve was not resected to preserve the ventricular function. The patient recovered his own activity.
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Affiliation(s)
- T Sugimoto
- Second Department of Surgery, Yamagata University School of Medicine, Japan
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29
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Kuraoka S, Orita H, Watanabe T, Shimasaki T, Abe H, Abe K, Inui K, Gotoh S, Minowa T, Washio M. [Antegrade or retrograde blood cardioplegic method: comparison of postsurgical right ventricular function and conduction disturbances]. Kyobu Geka 1995; 48:363-6. [PMID: 7745857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This study was undertaken to compare postsurgical right ventricular function and the occurrence of conduction disturbances after employing cold blood antegrade or retrograde cardioplegia during open heart surgery. Thirty-four patients were divided into AC (antegrade) and RC (retrograde) groups for the difference of route for delivery of cardioplegic solutions. Preoperative evaluation of cardiac and respiratory function revealed to be equal characteristics between the groups. Postoperatively, A-aDO2 and respiratory index (RI) as functional parameters of oxygenation capacity, LVSWI, RVSWI, dosage of dopamine and conduction disturbances were monitored at 0, 3, 6, 12 hours after termination of cardiopulmonary bypass and at extubation period. Although the recovery of respiratory function and left ventricular function were similar in both groups, temporal suppression of right ventricular function was indicated in RC group during early period after surgery, and then recovered to the same values of AC group within 3 hours. In RC group, several type of conduction disturbances were detected in 28 per cent of patients. But none of the persistent conduction disturbances were remained in all patients. We suggest retrograde coronary sinus perfusion may emerge as a valuable alternative to antegrade methods for delivery of cardioplegia.
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Affiliation(s)
- S Kuraoka
- Second Department of Surgery, Yamagata University School of Medicine, Japan
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30
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Kobayashi J, Asahi T, Ichiki M, Saito K, Shimasaki T, Yoshii H, Itagaki Y, Ikawa H. Optical study on the phase transition of lead lanthanum zirconate titanate Pb0.92La0.08(Zr0.70Ti0.30)0.98O3 ceramics. Phys Rev B Condens Matter 1995; 51:763-778. [PMID: 9978225 DOI: 10.1103/physrevb.51.763] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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31
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Shimasaki T, Watanabe T, Nishimura K, Nemoto H, Goto S, Washio M. [A case of nontraumatic rupture of ascending aorta]. Kyobu Geka 1994; 47:749-51. [PMID: 8057564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A 34-year-old man became shock caused by nontraumatic ascending aortic rupture. He was urgently operated. The aortic annulus was mildly ectatic and right coronary cusp was aneurysmal but not perforated. There was a small laceration in the anterior aortic wall without dissection. Cabrol operation was performed.
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Affiliation(s)
- T Shimasaki
- 2nd Department of Surgery, Yamagata University School of Medicine, Japan
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32
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Kuraoka S, Orita H, Watanabe T, Shimasaki T, Nakamura C, Washio M. [Reoperations for complications after mechanical valve replacement]. Kyobu Geka 1994; 47:672-5. [PMID: 7967287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Among 310 patients with mechanical valve replacement, 24 patients required reoperations for three types of complications; 12 disc immobilizations on 10 patients, 9 prosthetic valve endocarditis (PVE) on 8 patients and 8 perivalvular leakage or aortic pseudoaneurysm on 7 patients. Long-term survival was 71 percent for PVE and leakage, and 20 percent for emergency surgery of disc immobilization with mean follow up of 67 months. We suggest a few compromised patients with healed fungal endocarditis might show various types of prosthetic valve complications such as tissue ingrowth, late perivalvular leakage or pseudoaneurysmal formation.
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Affiliation(s)
- S Kuraoka
- Second Department of Surgery, Yamagata University School of Medicine, Japan
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33
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Shimasaki T, Oshikiri T, Uchino H, Washio M. [The relation between the time and the fatigue of skeletal muscle ventricle]. Nihon Kyobu Geka Gakkai Zasshi 1993; 41:2029-33. [PMID: 8228405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
It is generally recognized that if skeletal muscle is stimulated corresponding with the heart rate to assist the cardiac performance, the contraction power of the skeletal muscle decreases in a few minutes. It becomes necessary that the skeletal muscle is electrically stimulated in 6-9 weeks to lead into the transformation or that the muscle is laid without working after operation in 6-9 weeks to wait for growing of the collateral vessels. The observation time of the fatigue phenomenon in many studies is, however, short and it is not understandable that the contraction power decreases near to zero although the type I fibers remain. So we studied the relationship between the time and the pressure assist of the skeletal muscle ventricle (SMV). It was concluded that 1) the cause of the power decrease is not only the fatigue but the operative invasion. 2) in our setting, when SMV was stimulated in the ratio of 1:4 or 1:10 to the heart rate, the power recovered within 3 hours. 3) if the initial setting of the drive is light enough, the preconditioning or the vascular delay will be unnecessary and the working transformation or the in situ training will practicable.
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Affiliation(s)
- T Shimasaki
- Second Department of Surgery, Yamagata University School of Medicine, Japan
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34
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Shimasaki T, Ohira H, Hosaka J, Nagae N, Washio M. [A hanger for thoracic surgery]. Kyobu Geka 1993; 46:856-7. [PMID: 8377312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A new hanger for thoracic operation is introduced. This hanger for draping cloth is made for the purpose 1) of isolating the operative field from the anesthetist, 2) of keeping the broad hygienic area around the operator, 3) of keeping the area to handle the endotracheal tube for the anesthetist, 4) of keeping the area on the cranial side of the patient where the second assistant is able to stand, 5) of keeping the area for the watcher to stand.
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Affiliation(s)
- T Shimasaki
- Department of Cardiovascular Surgery, General Hobara Central Hospital, Fukushima, Japan
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35
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Kaneko S, Shimasaki T, Kusakabe I. Purification and some properties of intracellular alpha-L-arabinofuranosidase from Aspergillus niger 5-16. Biosci Biotechnol Biochem 1993; 57:1161-5. [PMID: 7763988 DOI: 10.1271/bbb.57.1161] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [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: 01/27/2023]
Abstract
alpha-L-Arabinofuranosidase was purified from a cell-free extract of Aspergillus niger 5-16 by chromatographies on DEAE-Toyopearl, SP-Toyopearl, Ultro-gel AcA 44, Mono P, and TSK-Gel G3000SW. The final preparation thus obtained showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were 67,000 by SDS-polyacrylamide gel electrophoresis and pH 3.5 by isoelectric focusing. The alpha-L-arabinofuranosidase contained amino acids in the order of Asx > Gly > Ala > Thr > Glx = Ser. The enzyme had maximum activity at pH 4.0 and 60 degrees C, and was stable from pH 4 to 7 and at temperatures up to 30 degrees C. The enzyme activity was not affected considerably by either metal ions or chemical reagents. The enzyme released arabinose from p-nitrophenyl-alpha-L-arabinofuranoside, O-alpha-L-arabinofuranosyl-(1-->3)-O-beta-D-xylopyranosyl-(1-->4)-D- xylopyranose, and arabinan, but not from O-beta-D-xylopyranosyl-(1-->4)-O-[alpha-L-arabinofuranosyl- (1-->3)]-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose, O-beta-D-xylopyranosyl-(1-->2)-O-alpha-L-arabinofuranosyl-(1-->3)-O-beta -D- xylopyranosyl-(1-->4)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose, gum arabic, or arabinoxylan. The limit of hydrolysis of arabinan was about 58% even when the enzyme was sufficiently in excess.
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Affiliation(s)
- S Kaneko
- Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan
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36
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Shimasaki T, Masaoka T, Hirooka S, Abe H, Watanabe T, Washio M. [Hygienic handling in cardiac surgery]. Kyobu Geka 1993; 46:319-20. [PMID: 8468855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Some points regarding the hygienic handling in cardiac surgery are mentioned. The sternal infection or mediastinitis is still one of the most important complications after cardiac operation especially when ITA is used for CABG. After we paid much attention to these points, the postoperative sternal infection has decreased obviously.
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Affiliation(s)
- T Shimasaki
- Second Department of Surgery, Yamagata University School of Medicine, Japan
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37
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Watanabe T, Shimasaki T, Kuraoka S, Abe H, Iijima Y, Washio M. Retrograde cerebral perfusion against massive air embolism during cardiopulmonary bypass. J Thorac Cardiovasc Surg 1992; 104:532-3. [PMID: 1495324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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38
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Watanabe H, Maeda K, Minowa T, Shimasaki T, Shimanuki T, Kasuya S, Sakashita I, Takano S, Kato K. [A case of tricuspid pouch associated with ventricular septal defect and functional left ventricular-right atrial communication]. Kyobu Geka 1992; 45:271-4. [PMID: 1552688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We reported a 60-year-old woman with tricuspid pouch associated with ventricular septal defect and subsequent left ventricular-right atrial communication. Preoperative angiographic findings suggested the presence of membranous septal aneurysm, ventricular and atrial septal defects, and tricuspid insufficiency. However, at operation, besides perimembranous inlet type ventricular septal defect, a pouch, 1.5 cm in diameter was found in the adjacent part to the septal leaflet within the anterior one of the tricuspid valve. The ventricular septal defect was closed with a patch. From these findings, it is speculated that the tricuspid pouch was formed by the effect of jet stream through the ventricular septal defect.
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Affiliation(s)
- H Watanabe
- Department of Thoracic and Cardiovascular Surgery, Tachikawa General Hospital
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Kuraoka S, Nakamura C, Watanabe T, Orita H, Shimanuki T, Shimasaki T, Fukasawa M, Abe H, Iijima Y, Washio M. [Mechanical factors of a severe type of ventricular arrhythmia after Cabrol's operation]. Kyobu Geka 1991; 44:629-35. [PMID: 1895598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Severe type of ventricular arrhythmia was noticed after Cabrol's operation more frequently than usual reperfusion arrhythmia. Nine patients received Cabrol's operation and 2 of Bentall's were divided into 2 groups according to the occurrence of postsurgical ventricular arrhythmia (Lown's classification grade 0-3: 5 cases, grade 4 A-5: 6 cases), and then the factors contributed to the arrhythmia were analyzed. There were no significant differences between the 2 groups on the point of the characteristics of the cases with or without emergent surgery for, such as ruptured or dissecting thoracic aortic aneurysms or other complicated lesions, the degree of surgical damage, or preoperative cardiac function. The only significant difference between the groups was the angle overheading to the central point of left coronary orifice anastomosed with intermediate tube from the extensive line of the prosthetic flange obtained in the left anterior oblique views on the angiography. The mean value of the angle of the severe group (grade 4 A-5) was 41 +/- 6.8 degrees (mean +/- SD) and significantly acute than the angle of the other group (grade 0-3: 57 +/- 6.4 degrees). This fact suggested that the main reason of the ventricular arrhythmia was coronary ischemia caused by compression of the intermediate tube after formation of massive hematoma within the aneurysmal capsule wrapped over the composite graft.
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Affiliation(s)
- S Kuraoka
- Second Department of Surgery, Yamagata University School of Medicine
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40
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Shimasaki T, Washio M. [A newly designed curved venous cannula with cuff for cardiopulmonary bypass]. Kyobu Geka 1991; 44:477-8. [PMID: 2072586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new venous cannula for CPB was designed. This cannula is curved at right angles to connect to line directly and has cuff to prevent sliding out. We have no trouble with venous return and operative field is not disturbed with CPB lines by using this cannula.
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Affiliation(s)
- T Shimasaki
- Second Department of Surgery, Yamagata University School of Medicine
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41
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Shimasaki T, Minami K, Koerfer R, Gleichmann U. [Transaortic myectomy for hypertrophic obstructive cardiomyopathy--efficacy of intraoperative pressure measurement]. Nihon Kyobu Geka Gakkai Zasshi 1990; 38:2091-6. [PMID: 2266283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The many aspects of postoperative course of hypertrophic obstructive cardiomyopathy (HOCM) have been apparent, while many studies concerning long-term follow up have been published in recent years. Many surgical approaches have been performed but recently transaortic subvalvular myectomy is most common. This study reviews 22 patients with HOCM operated on between 1984 and 1989. Transaortic approach was used for all adult patients. One patient had a complication with an iatrogenic VSD, which was closed by Dacron patch during the procedure. There was one hospital death; She is a 67 year-old woman who died due to an acute abdomen. All 14 patients followed up over 3 months had significant functional improvement. Our retrospective study suggests that myectomy in patient with HOCM seems to be not only palliative but curative operative method. Left atrial- and left ventricular dimension tended to normalize in the postoperative course. The intraoperative estimation of Brockenbrough phenomenon is effective to assess the release of left ventricular outflow obstruction.
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Affiliation(s)
- T Shimasaki
- Department of Thoracic and Cardiovascular Surgery, Herzzentrum Nordrhein-Westfalen, West Germany
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Mochizuki M, Tamura M, Shimasaki T, Niizeki K, Shimouchi A. A new indirect method for measuring arteriovenous O2 content difference and cardiac output from O2 and CO2 concentrations by rebreathing air. Jpn J Physiol 1984; 34:295-306. [PMID: 6433092 DOI: 10.2170/jjphysiol.34.295] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A new indirect method for measuring the arteriovenous O2 content difference (avDO2) was developed. The avDO2 was calculated by dividing the gradient of the CO2 dissociation curve by that of a gas exchange ratio against PCO2. The latter slope was obtained from O2 and CO2 concentrations in rebreathing air. The validity of the method was tested preliminarily in human subjects by comparing the cardiac output calculated from avDO2 and O2 uptake (VO2) with that measured hitherto by other authors, and then in dogs by comparing the calculated avDO2 with the measured value. In the dog experiments, the rebreathing was performed 7 times in each of 7 dogs. Immediately after the rebreathing arterial and mixed venous blood were sampled and analyzed for avDO2. For each rebreathing period the avDO2 was calculated by using the CO2 dissociation curve obtained in the individual dogs. The correlation coefficient between the measured and calculated avDO2 was 0.87, demonstrating reasonable validity of the method. The VO2 was further measured from the time interval during which a known amount of pure O2 was consumed. Then, the cardiac output was calculated by dividing the VO2 by the measured and calculated avDO2. The correlation coefficient between the respective cardiac output values was 0.88, indicating the reliability of using the calculated avDO2.
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