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Honda S, Imamura A, Seki Y, Chigira K, Iwasa M, Hayami K, Nomura T, Ohkubo S, Ookawa T, Nagano AJ, Matsuoka M, Tanaka Y, Adachi S. Genome-wide association study of leaf photosynthesis using a high-throughput gas exchange system in rice. Photosynth Res 2024; 159:17-28. [PMID: 38112862 DOI: 10.1007/s11120-023-01065-3] [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] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 11/13/2023] [Indexed: 12/21/2023]
Abstract
Enhancing leaf photosynthetic capacity is essential for improving the yield of rice (Oryza sativa L.). Although the exploitation of natural genetic resources is considered a promising approach to enhance photosynthetic capacity, genomic factors related to the genetic diversity of leaf photosynthetic capacity have yet to be fully elucidated due to the limitation of measurement efficiency. In this study, we aimed to identify novel genomic regions for the net CO2 assimilation rate (A) by combining genome-wide association study (GWAS) and the newly developed rapid closed gas exchange system MIC-100. Using three MIC-100 systems in the field at the vegetative stage, we measured A of 168 temperate japonica rice varieties with six replicates for three years. We found that the modern varieties exhibited higher A than the landraces, while there was no significant relationship between the release year and A among the modern varieties. Our GWAS scan revealed two major peaks located on chromosomes 4 and 8, which were repeatedly detected in the different experiments and in the generalized linear modelling approach. We suggest that high-throughput gas exchange measurements combined with GWAS is a reliable approach for understanding the genetic mechanisms underlying photosynthetic diversities in crop species.
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Affiliation(s)
- Sotaro Honda
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Ayumu Imamura
- Graduate School of Agriculture, Ibaraki University, Ibaraki, 300-0393, Japan
| | - Yoshiaki Seki
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Koki Chigira
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Marina Iwasa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Kentaro Hayami
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Tomohiro Nomura
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Satoshi Ohkubo
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Taiichiro Ookawa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan
| | - Atsushi J Nagano
- Faculty of Agriculture, Ryukoku University, Shiga, 520-2194, Japan
- Institute for Advanced Biosciences, Keio University, Yamagata, 997-0017, Japan
| | - Makoto Matsuoka
- Faculty of Food and Agricultural Sciences, Institute of Fermentation Sciences, Fukushima University, Fukushima, 960-1296, Japan
| | - Yu Tanaka
- Graduate School of Environment and Life Science, Okayama University, Okayama, 700-8530, Japan
| | - Shunsuke Adachi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan.
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Miyagi A, Mori K, Ishikawa T, Ohkubo S, Adachi S, Yamaguchi M, Ookawa T, Kotake T, Kawai-Yamada M. Metabolomic analysis of rice brittle culm mutants reveals each mutant- specific metabolic pattern in each organ. Metabolomics 2022; 18:95. [PMID: 36409428 DOI: 10.1007/s11306-022-01958-9] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 11/11/2022] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Plant cell walls play an important role in providing physical strength and defence against abiotic stress. Rice brittle culm (bc) mutants are a strength-decreased mutant because of abnormal cell walls, and it has been reported that the causative genes of bc mutants affect cell wall composition. However, the metabolic alterations in each organ of bc mutants have remained unknown. OBJECTIVES To evaluate the metabolic changes in rice bc mutants, comparative analysis of the primary metabolites was conducted. METHODS The primary metabolites in leaves, internodes, and nodes of rice bc mutants and wild-type control were measured using CE- and LC-MS/MS. Multivariate analyses using metabolomic data was performed. RESULTS We found that mutations in each bc mutant had different effects on metabolism. For example, higher oxalate content was observed in bc3 and bc1 bc3 mutants, suggesting that surplus carbon that was not used for cell wall components might be used for oxalate synthesis. In addition, common metabolic alterations such as a decrease of sugar nucleotides in nodes were found in bc1 and Bc6, in which the causative genes are involved in cellulose accumulation. CONCLUSION These results suggest that metabolic analysis of the bc mutants could elucidate the functions of causative gene and improve the cell wall components for livestock feed or bioethanol production.
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Affiliation(s)
- Atsuko Miyagi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama, 338-8570, Japan.
- Faculty of Agriculture, Yamagata University, 1-23 Wakaba-Machi, Tsuruoka, Yamagata, 997-8555, Japan.
| | - Kazuhisa Mori
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama, 338-8570, Japan
| | - Toshiki Ishikawa
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama, 338-8570, Japan
| | - Satoshi Ohkubo
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3‑5‑8 Saiwai‑cho, Fuchu-City, Tokyo, 183‑8509, Japan
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai-City, Miyagi, 980-8577, Japan
| | - Shunsuke Adachi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3‑5‑8 Saiwai‑cho, Fuchu-City, Tokyo, 183‑8509, Japan
| | - Masatoshi Yamaguchi
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama, 338-8570, Japan
| | - Taiichiro Ookawa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3‑5‑8 Saiwai‑cho, Fuchu-City, Tokyo, 183‑8509, Japan
| | - Toshihisa Kotake
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama, 338-8570, Japan
| | - Maki Kawai-Yamada
- Graduate School of Science and Engineering, Saitama University, 225 Shimo-Okubo, Sakura-Ku, Saitama-City, Saitama, 338-8570, Japan.
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Arashida H, Odake H, Sugawara M, Noda R, Kakizaki K, Ohkubo S, Mitsui H, Sato S, Minamisawa K. Evolution of rhizobial symbiosis islands through insertion sequence-mediated deletion and duplication. ISME J 2022; 16:112-121. [PMID: 34272493 PMCID: PMC8692435 DOI: 10.1038/s41396-021-01035-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 05/27/2021] [Accepted: 06/03/2021] [Indexed: 11/08/2022]
Abstract
Symbiosis between organisms influences their evolution via adaptive changes in genome architectures. Immunity of soybean carrying the Rj2 allele is triggered by NopP (type III secretion system [T3SS]-dependent effector), encoded by symbiosis island A (SymA) in B. diazoefficiens USDA122. This immunity was overcome by many mutants with large SymA deletions that encompassed T3SS (rhc) and N2 fixation (nif) genes and were bounded by insertion sequence (IS) copies in direct orientation, indicating homologous recombination between ISs. Similar deletion events were observed in B. diazoefficiens USDA110 and B. japonicum J5. When we cultured a USDA122 strain with a marker gene sacB inserted into the rhc gene cluster, most sucrose-resistant mutants had deletions in nif/rhc gene clusters, similar to the mutants above. Some deletion mutants were unique to the sacB system and showed lower competitive nodulation capability, indicating that IS-mediated deletions occurred during free-living growth and the host plants selected the mutants. Among 63 natural bradyrhizobial isolates, 2 possessed long duplications (261-357 kb) harboring nif/rhc gene clusters between IS copies in direct orientation via homologous recombination. Therefore, the structures of symbiosis islands are in a state of flux via IS-mediated duplications and deletions during rhizobial saprophytic growth, and host plants select mutualistic variants from the resultant pools of rhizobial populations. Our results demonstrate that homologous recombination between direct IS copies provides a natural mechanism generating deletions and duplications on symbiosis islands.
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Affiliation(s)
- Haruka Arashida
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Haruka Odake
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Masayuki Sugawara
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Ryota Noda
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Kaori Kakizaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Satoshi Ohkubo
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Hisayuki Mitsui
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Shusei Sato
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan
| | - Kiwamu Minamisawa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai, 980-8577, Japan.
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Kashima M, Sakamoto RL, Saito H, Ohkubo S, Tezuka A, Deguchi A, Hashida Y, Kurita Y, Iwayama K, Adachi S, Nagano AJ. Genomic Basis of Transcriptome Dynamics in Rice under Field Conditions. Plant Cell Physiol 2021; 62:1436-1445. [PMID: 34131748 PMCID: PMC8600290 DOI: 10.1093/pcp/pcab088] [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] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/09/2021] [Accepted: 06/15/2021] [Indexed: 05/07/2023]
Abstract
How genetic variations affect gene expression dynamics of field-grown plants remains unclear. Expression quantitative trait loci (eQTL) analysis is frequently used to find genomic regions underlying gene expression polymorphisms. This approach requires transcriptome data for the complete set of the QTL mapping population under the given conditions. Therefore, only a limited range of environmental conditions is covered by a conventional eQTL analysis. We sampled sparse time series of field-grown rice from chromosome segment substitution lines (CSSLs) and conducted RNA sequencing (RNA-Seq). Then, by using statistical analysis integrating meteorological data and the RNA-Seq data, we identified 1,675 eQTLs leading to polymorphisms in expression dynamics under field conditions. A genomic region on chromosome 11 influences the expression of several defense-related genes in a time-of-day- and scaled-age-dependent manner. This includes the eQTLs that possibly influence the time-of-day- and scaled-age-dependent differences in the innate immunity between Koshihikari and Takanari. Based on the eQTL and meteorological data, we successfully predicted gene expression under environments different from training environments and in rice cultivars with more complex genotypes than the CSSLs. Our novel approach of eQTL identification facilitated the understanding of the genetic architecture of expression dynamics under field conditions, which is difficult to assess by conventional eQTL studies. The prediction of expression based on eQTLs and environmental information could contribute to the understanding of plant traits under diverse field conditions.
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Affiliation(s)
- Makoto Kashima
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194, Japan
| | | | - Hiroki Saito
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwake, Sakyo-ku, Kyoto 606-8317, Japan
- Tropical Agriculture Research Front, Japan International Research Center for Agricultural Sciences, Maezato 1091-1, Ishigaki, Okinawa 907-0002, Japan
| | - Satoshi Ohkubo
- Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwake, Sakyo-ku, Kyoto 606-8317, Japan
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509, Japan
| | - Ayumi Tezuka
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194, Japan
| | - Ayumi Deguchi
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194, Japan
| | - Yoichi Hashida
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194, Japan
| | - Yuko Kurita
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194, Japan
| | - Koji Iwayama
- Faculty of Data Science, Shiga University, Bamba 1-1-1, Hikone, Shiga 522-0069, Japan
| | - Shunsuke Adachi
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Saiwaicho 3-5-8, Fuchu, Tokyo 183-8509, Japan
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Honda S, Ohkubo S, San NS, Nakkasame A, Tomisawa K, Katsura K, Ookawa T, Nagano AJ, Adachi S. Maintaining higher leaf photosynthesis after heading stage could promote biomass accumulation in rice. Sci Rep 2021; 11:7579. [PMID: 33828128 PMCID: PMC8027620 DOI: 10.1038/s41598-021-86983-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
Leaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO2 assimilation rate (A) of two elite rice (Oryza sativa) cultivars and 76 inbred lines across the whole growing season. The integrated A value after heading was positively associated with crop growth rate (CGR) from heading to harvest, but that before heading was not. A curve-smoothing analysis of A after heading showed that accumulated A at > 80% of its maximum (A80) was positively correlated with CGR in analyses of all lines mixed and of lines grouped by genetic background, while the maximum A and accumulated A at ≤ 80% were less strongly correlated with CGR. We also found a genomic region (~ 12.2 Mb) that may enhance both A80 and aboveground biomass at harvest. We propose that maintaining a high A after heading, rather than having high maximum A, is a potential target for enhancing rice biomass accumulation.
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Affiliation(s)
- Sotaro Honda
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Satoshi Ohkubo
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Nan Su San
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Anothai Nakkasame
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Kazuki Tomisawa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Keisuke Katsura
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Taiichiro Ookawa
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan
| | - Atsushi J Nagano
- Faculty of Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga, 520-2194, Japan
| | - Shunsuke Adachi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
- College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Inashiki, Ibaraki, 300-0393, Japan.
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Matsuda Y, Ohkubo S, Nakano-Narusawa Y, Fukumura Y, Hirabayashi K, Yamaguchi H, Sahara Y, Kawanishi A, Takahashi S, Arai T, Kojima M, Mino-Kenudson M. Objective assessment of tumor regression in post-neoadjuvant therapy resections for pancreatic ductal adenocarcinoma: comparison of multiple tumor regression grading systems. Sci Rep 2020; 10:18278. [PMID: 33106543 PMCID: PMC7588464 DOI: 10.1038/s41598-020-74067-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [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: 03/25/2020] [Accepted: 09/24/2020] [Indexed: 12/11/2022] Open
Abstract
Neoadjuvant therapy is increasingly used to control local tumor spread and micrometastasis of pancreatic ductal adenocarcinoma (PDAC). Pathology assessments of treatment effects might predict patient outcomes after surgery. However, there are conflicting reports regarding the reproducibility and prognostic performance of commonly used tumor regression grading systems, namely College of American Pathologists (CAP) and Evans' grading system. Further, the M.D. Anderson Cancer Center group (MDA) and the Japan Pancreas Society (JPS) have introduced other grading systems, while we recently proposed a new, simple grading system based on the area of residual tumor (ART). Herein, we aimed to assess and compare the reproducibility and prognostic performance of the modified ART grading system with those of the four grading systems using a multicenter cohort. The study cohort consisted of 97 patients with PDAC who had undergone post-neoadjuvant pancreatectomy at four hospitals. All patients were treated with gemcitabine and S-1 (GS)-based chemotherapies with/without radiation. Two pathologists individually evaluated tumor regression in accordance with the CAP, Evans', JPS, MDA and ART grading systems, and interobserver concordance was compared between the five systems. The ART grading system was a 5-tiered system based on a number of 40× microscopic fields equivalent to the surface area of the largest ART. Furthermore, the final grades, which were either the concordant grades of the two observers or the majority grades, including those given by the third observer, were correlated with patient outcomes in each system. The interobserver concordance (kappa value) for Evans', CAP, MDA, JPS and ART grading systems were 0.34, 0.50, 0.65, 0.33, and 0.60, respectively. Univariate analysis showed that higher ART grades were significantly associated with shorter overall survival (p = 0.001) and recurrence-free survival (p = 0.005), while the other grading systems did not show significant association with patient outcomes. The present study revealed that the ART grading system that was designed to be simple and more objective has achieved high concordance and showed a prognostic value; thus it may be most practical for assessing tumor regression in post-neoadjuvant resections for PDAC.
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Affiliation(s)
- Yoko Matsuda
- Oncology Pathology, Department of Pathology and Host-Defense, Faculty of Medicine, Kagawa University, Kagawa, Japan.,Department of Pathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Satoshi Ohkubo
- Division of Hepatobiliary and Pancreatic Surgery, National Cancer Center Hospital East, Chiba, Japan
| | - Yuko Nakano-Narusawa
- Oncology Pathology, Department of Pathology and Host-Defense, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yuki Fukumura
- Department of Human Pathology, Juntendo University, School of Medicine, Tokyo, Japan
| | - Kenichi Hirabayashi
- Department of Pathology, Tokai University School of Medicine, Kanagawa, Japan
| | - Hiroshi Yamaguchi
- Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan
| | - Yatsuka Sahara
- Department of Gastrointestinal and Pediatric Surgery, Tokyo Medical University, Tokyo, Japan
| | - Aya Kawanishi
- Department of Gastroenterology and Hepatology, Tokai University School of Medicine, Kanagawa, Japan
| | - Shinichiro Takahashi
- Division of Hepatobiliary and Pancreatic Surgery, National Cancer Center Hospital East, Chiba, Japan
| | - Tomio Arai
- Department of Pathology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Motohiro Kojima
- Division of Pathology, Research Center for Innovative Oncology, National Cancer Center Hospital East, 6-5-1, Kashiwanoha, Kashiwa-shi, Chiba, Japan.
| | - Mari Mino-Kenudson
- Department of Pathology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Warren 122, Boston, MA, USA.
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Ohkubo S, Tanaka Y, Yamori W, Adachi S. Rice Cultivar Takanari Has Higher Photosynthetic Performance Under Fluctuating Light Than Koshihikari, Especially Under Limited Nitrogen Supply and Elevated CO 2. Front Plant Sci 2020; 11:1308. [PMID: 32983198 PMCID: PMC7490297 DOI: 10.3389/fpls.2020.01308] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/11/2020] [Indexed: 05/31/2023]
Abstract
Plants in the field experience dynamic changes of sunlight rather than steady-state irradiation. Therefore, increasing the photosynthetic rate of an individual leaf under fluctuating light is essential for improving crop productivity. The high-yielding indica rice (Oryza sativa L.) cultivar Takanari is considered a potential donor of photosynthesis genes because of its higher steady-state photosynthesis at both atmospheric and elevated CO2 concentrations than those of several Japanese commercial cultivars, including Koshihikari. Photosynthetic induction after a sudden increase in light intensity is faster in Takanari than in Koshihikari, but whether the daily carbon gain of Takanari outperforms that of Koshihikari under fluctuating light in the field is unclear. Here we report that Takanari has higher non-steady-state photosynthesis, especially under low nitrogen (N) supply, than Koshihikari. In a pot experiment, Takanari had greater leaf carbon gain during the initial 10 min after a sudden increase in irradiation and higher daily CO2 assimilation under simulated natural fluctuating light, at both atmospheric (400 ppm) and elevated (800 ppm) CO2 concentrations. The electron transport rate during a day under field conditions with low N supply was also higher in Takanari than in Koshihikari. Although the advantages of Takanari were diminished under high N supply, photosynthetic N use efficiency was consistently higher in Takanari than in Koshihikari, under both low and high N supply. This study demonstrates that Takanari is a promising donor parent to use in breeding programs aimed at increasing CO2 assimilation in a wide range of environments, including future higher CO2 concentrations.
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Affiliation(s)
- Satoshi Ohkubo
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Yu Tanaka
- Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Wataru Yamori
- Graduate School of Agricultural and Life Sciences, Institute for Sustainable Agro-Ecosystem Services, The University of Tokyo, Nishitokyo, Japan
| | - Shunsuke Adachi
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Fuchu, Japan
- College of Agriculture, Ibaraki University, Inashiki, Japan
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Adachi S, Tanaka Y, Miyagi A, Kashima M, Tezuka A, Toya Y, Kobayashi S, Ohkubo S, Shimizu H, Kawai-Yamada M, Sage RF, Nagano AJ, Yamori W. High-yielding rice Takanari has superior photosynthetic response to a commercial rice Koshihikari under fluctuating light. J Exp Bot 2019; 70:5287-5297. [PMID: 31257443 PMCID: PMC6793460 DOI: 10.1093/jxb/erz304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 06/20/2019] [Indexed: 05/13/2023]
Abstract
Leaves within crop canopies experience variable light over the course of a day, which greatly affects photosynthesis and crop productivity. Little is known about the mechanisms of the photosynthetic response to fluctuating light and their genetic control. Here, we examined gas exchange, metabolite levels, and chlorophyll fluorescence during the photosynthetic induction response in an Oryza sativa indica cultivar with high yield (Takanari) and a japonica cultivar with lower yield (Koshihikari). Takanari had a faster induction response to sudden increases in light intensity than Koshihikari, as demonstrated by faster increases in net CO2 assimilation rate, stomatal conductance, and electron transport rate. In a simulated light regime that mimicked a typical summer day, the faster induction response in Takanari increased daily CO2 assimilation by 10%. The faster response of Takanari was explained in part by its maintenance of a larger pool of Calvin-Benson cycle metabolites. Together, the rapid responses of electron transport rate, metabolic flux, and stomatal conductance in Takanari contributed to the greater daily carbon gain under fluctuating light typical of natural environments.
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Affiliation(s)
- Shunsuke Adachi
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Saiwaicho, Fuchu, Tokyo, Japan
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Japan
| | - Yu Tanaka
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Japan
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan
| | - Atsuko Miyagi
- Graduate School of Science and Engineering, Saitama University, Shimo-Okubo, Sakura-ku, Saitama, Japan
| | - Makoto Kashima
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani, Seta Oe-cho, Otsu, Shiga, Japan
| | - Ayumi Tezuka
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani, Seta Oe-cho, Otsu, Shiga, Japan
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Yamadaoka, Suita, Osaka, Japan
| | - Shunzo Kobayashi
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan
| | - Satoshi Ohkubo
- Institute of Global Innovation Research, Tokyo University of Agriculture and Technology, Saiwaicho, Fuchu, Tokyo, Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, Yamadaoka, Suita, Osaka, Japan
| | - Maki Kawai-Yamada
- Graduate School of Science and Engineering, Saitama University, Shimo-Okubo, Sakura-ku, Saitama, Japan
| | - Rowan F Sage
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Atsushi J Nagano
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Japan
- Faculty of Agriculture, Ryukoku University, Yokotani, Seta Oe-cho, Otsu, Shiga, Japan
| | - Wataru Yamori
- Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
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9
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Ohkubo S, Miyashita H. A niche for cyanobacteria producing chlorophyll f within a microbial mat. ISME J 2017; 11:2368-2378. [PMID: 28622287 PMCID: PMC5607378 DOI: 10.1038/ismej.2017.98] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/03/2017] [Accepted: 05/15/2017] [Indexed: 11/09/2022]
Abstract
Acquisition of additional photosynthetic pigments enables photosynthetic organisms to survive in particular niches. To reveal the ecological significance of chlorophyll (Chl) f, we investigated the distribution of Chl and cyanobacteria within two microbial mats. In a 7-mm-thick microbial mat beneath the running water of the Nakabusa hot spring, Japan, Chl f was only distributed 4.0-6.5 mm below the surface, where the intensity of far-red light (FR) was higher than that of photosynthetically active radiation (PAR). In the same mat, two ecotypes of Synechococcus and two ecotypes of Chl f-producing Leptolyngbya were detected in the upper and deeper layers, respectively. Only the Leptolyngbya strains could grow when FR was the sole light source. These results suggest that the deeper layer of the microbial mat was a habitat for Chl f-producing cyanobacteria, and Chl f enabled them to survive in a habitat with little PAR.
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Affiliation(s)
- Satoshi Ohkubo
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Hideaki Miyashita
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
- Graduate School of Global and Environmental Studies, Kyoto University, Kyoto, Japan
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10
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Limaye R, Ballard A, Futrell E, Ahmed N, Ohkubo S. New Narratives in Global Health: Using Stories and Storytelling to
Promote Family Planning. Ann Glob Health 2017. [DOI: 10.1016/j.aogh.2017.03.236] [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: 10/19/2022] Open
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11
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Ohkubo S, Limaye R, Ahmed N, Ballard A. Blended Learning on Family Planning Policy Requirements: Key Findings and
Implications from a Mixed Methods Study. Ann Glob Health 2017. [DOI: 10.1016/j.aogh.2017.03.279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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12
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Muraoka H, Yoshimura C, Tsuji S, Hashimoto A, Mizutani T, Ohkubo S, Matsuo K, Utsugi T, Iwasawa Y. TAS4464, a novel highly potent NEDD8 activating enzyme inhibitor, demonstrates anti-tumor efficacy in rituximab-resistant double-hit lymphoma models. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)33052-0] [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: 11/25/2022]
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13
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Ashida K, Ohtani M, Yokoyama T, Kosai K, Ohkubo S. Full Scale Investigation of The Fire Performance of Urethane Foam Cushions Using Novoloid Fiber Products as Interlayer. J CELL PLAST 2016. [DOI: 10.1177/0021955x7801400602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- K. Ashida
- Market Development Research Laboratories Research Center, Mitsubishi Chemical Industries Limited
| | - M. Ohtani
- Market Development Research Laboratories Research Center, Mitsubishi Chemical Industries Limited
| | - T. Yokoyama
- Market Development Research Laboratories Research Center, Mitsubishi Chemical Industries Limited
| | - K. Kosai
- Market Development Research Laboratories Research Center, Mitsubishi Chemical Industries Limited
| | - S. Ohkubo
- Market Development Research Laboratories Research Center, Mitsubishi Chemical Industries Limited
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14
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Ashida K, Ohtani M, Yokoyama T, Ohkubo S. Novel Methods of Smoke Suppression in Isocyanurate Foams (II) Modification by Silicon-containing Compounds. J CELL PLAST 2016. [DOI: 10.1177/0021955x7801400503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- K. Ashida
- Market Development Research Laboratories, Mitsubishi Chemical Ind. Ltd. 1000 Kamoshida-cho, Midori-ku, Yokohama, 227, Japan
| | - M. Ohtani
- Market Development Research Laboratories, Mitsubishi Chemical Ind. Ltd. 1000 Kamoshida-cho, Midori-ku, Yokohama, 227, Japan
| | - T. Yokoyama
- Market Development Research Laboratories, Mitsubishi Chemical Ind. Ltd. 1000 Kamoshida-cho, Midori-ku, Yokohama, 227, Japan
| | - S. Ohkubo
- Market Development Research Laboratories, Mitsubishi Chemical Ind. Ltd. 1000 Kamoshida-cho, Midori-ku, Yokohama, 227, Japan
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15
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Saito T, Hamamoto S, Ueki T, Ohkubo S, Moldrup P, Kawamoto K, Komatsu T. Temperature change affected groundwater quality in a confined marine aquifer during long-term heating and cooling. Water Res 2016; 94:120-127. [PMID: 26938497 DOI: 10.1016/j.watres.2016.01.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
Global warming and urbanization together with development of subsurface infrastructures (e.g. subways, shopping complexes, sewage systems, and Ground Source Heat Pump (GSHP) systems) will likely cause a rapid increase in the temperature of relatively shallow groundwater reservoirs (subsurface thermal pollution). However, potential effects of a subsurface temperature change on groundwater quality due to changed physical, chemical, and microbial processes have received little attention. We therefore investigated changes in 34 groundwater quality parameters during a 13-month enhanced-heating period, followed by 14 months of natural or enhanced cooling in a confined marine aquifer at around 17 m depth on the Saitama University campus, Japan. A full-scale GSHP test facility consisting of a 50 m deep U-tube for circulating the heat-carrying fluid and four monitoring wells at 1, 2, 5, and 10 m from the U-tube were installed, and groundwater quality was monitored every 1-2 weeks. Rapid changes in the groundwater level in the area, especially during the summer, prevented accurate analyses of temperature effects using a single-well time series. Instead, Dual-Well Analysis (DWA) was applied, comparing variations in subsurface temperature and groundwater chemical concentrations between the thermally-disturbed well and a non-affected reference well. Using the 1 m distant well (temperature increase up to 7 °C) and the 10 m distant well (non-temperature-affected), the DWA showed an approximately linear relationships for eight components (B, Si, Li, dissolved organic carbon (DOC), Mg(2+), NH4(+), Na(+), and K(+)) during the combined 27 months of heating and cooling, suggesting changes in concentration between 4% and 31% for a temperature change of 7 °C.
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Affiliation(s)
- Takeshi Saito
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan.
| | - Shoichiro Hamamoto
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8567, Japan
| | - Takashi Ueki
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Satoshi Ohkubo
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Per Moldrup
- Department of Civil Engineering, Aalborg University, Sofiendalsvej 11, 9200, Aalborg SV, Denmark
| | - Ken Kawamoto
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
| | - Toshiko Komatsu
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, 338-8570, Japan
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16
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Ohkubo S, Muraoka H, Kodama Y, Ito K, Ito S, Hashimoto A, Yoshimura C, Utsugi T. 592 TAS-116, a highly selective inhibitor of heat shock protein 90a/β, inhibits tumor growth in biliary tract cancer mouse models. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70718-x] [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: 11/24/2022]
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17
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Aburai N, Ohkubo S, Miyashita H, Abe K. Composition of carotenoids and identification of aerial microalgae isolated from the surface of rocks in mountainous districts of Japan. ALGAL RES 2013. [DOI: 10.1016/j.algal.2013.03.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Yano Y, Numata M, Hachiya H, Ito S, Masadome T, Ohkubo S, Asano Y, Imato T. Application of a microbial sensor to the quality control of meat freshness. Talanta 2013; 54:255-62. [PMID: 18968247 DOI: 10.1016/s0039-9140(00)00637-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2000] [Revised: 10/23/2000] [Accepted: 10/25/2000] [Indexed: 10/18/2022]
Abstract
Samples of fresh meat stored at 5 degrees C were periodically removed from storage and washed with water for periods of up to 2 weeks. The amount of amino acids, polyamines and viable counts (number of bacteria) in the washed water were measured by using an HPLC system and a colony counting method. At the same time, the washed water was charged into a flow injection analysis (FIA) system combined a microbial sensor using yeast (Trichosporon cutaneum), which was developed in this work for monitoring the freshness of meat. A relationship between the sensor signals obtained by the FIA system and the amounts of polyamines and amino acids produced from the meat and the number of bacteria which had multiplied in the meat during the aging process was investigated. The sensor signal was found to correspond to increases in amino acid levels and viable counts in the meat with the storage time in the course of the first stage of aging. This is due to the fact that amino acids produced initially by enzymes in the meat serve as a source of nutrition for septic bacteria during the aging process, and as a result, the level of bacterial cells increases with increasing amounts of amino acids with the passage of days. A good correlation, with a correlation factor of 0.908, was obtained between the sensor signal and viable counts obtained by the colony counting method. The present sensor method was more sensitive than the colony counting method at the early stage of the aging process, where viable counts were in the vicinity of 10(4) g(-1).
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Affiliation(s)
- Y Yano
- Central Institute of Itoham Foods Inc, Kubogaoka, Moriya-machi, Ibaraki 302-0104, Japan
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19
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Ichikawa T, Maruhn JA, Itagaki N, Matsuyanagi K, Reinhard PG, Ohkubo S. Existence of an exotic torus configuration in high-spin excited states of 40Ca. Phys Rev Lett 2012; 109:232503. [PMID: 23368188 DOI: 10.1103/physrevlett.109.232503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Indexed: 06/01/2023]
Abstract
We investigate the possibility of the existence of the exotic torus configuration in the high-spin excited states of (40)Ca. We here consider the spin alignments about the symmetry axis. To this end, we use a three-dimensional cranked Skyrme Hartree-Fock method and search for stable single-particle configurations. We find one stable state with the torus configuration at the total angular momentum J=60 ħ and an excitation energy of about 170 MeV in all calculations using various Skyrme interactions. The total angular momentum J=60 ħ consists of aligned 12 nucleons with the orbital angular momenta Λ=+4, +5, and +6 for spin-up or -down neutrons and protons. The obtained results strongly suggest that a macroscopic amount of circulating current breaking the time-reversal symmetry emerges in the high-spin excited state of (40)Ca.
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Affiliation(s)
- T Ichikawa
- Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
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20
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Yoshimura C, Kitade M, Oshiumi H, Uno T, Chong-Takata K, Kawai Y, Yamashita S, Mizutani T, Ohkubo S, Utsugi T. 292 Evolution of Highly Selective HSP90a/β Inhibitors with Unique Binding Mode. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)72090-7] [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: 11/27/2022]
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21
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Yamada S, Ohkubo S, Miyashita H, Setoguchi H. Genetic diversity of symbiotic cyanobacteria in Cycas revoluta (Cycadaceae). FEMS Microbiol Ecol 2012; 81:696-706. [PMID: 22537413 DOI: 10.1111/j.1574-6941.2012.01403.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 04/17/2012] [Accepted: 04/19/2012] [Indexed: 11/28/2022] Open
Abstract
The diversity of cyanobacterial species within the coralloid roots of an individual and populations of Cycas revoluta was investigated based on 16S rRNA gene sequences. Sixty-six coralloid roots were collected from nine natural populations of cycads on Kyushu and the Ryukyu Islands, covering the entire distribution range of the species. Approximately 400 bp of the 5'-end of 16S rRNA genes was amplified, and each was identified by denaturing gradient gel electrophoresis. Most coralloid roots harbored only one cyanobiont, Nostoc, whereas some contained two or three, representing cyanobiont diversity within a single coralloid root isolated from a natural habitat. Genotypes of Nostoc within a natural population were occasionally highly diverged and lacked DNA sequence similarity, implying genetic divergence of Nostoc. On the other hand, Nostoc genotypes showed no phylogeographic structure across the distribution range, while host cycads exhibited distinct north-south differentiation. Cycads may exist in symbiosis with either single or multiple Nostoc strains in natural soil habitats.
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Affiliation(s)
- Shuntaro Yamada
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsucho, Sakyo-ku, Kyoto, Japan
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22
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Ohkubo S, Miyashita H. Selective detection and phylogenetic diversity of Acaryochloris spp. that exist in association with didemnid ascidians and sponge. Microbes Environ 2012; 27:217-25. [PMID: 22353766 PMCID: PMC4036056 DOI: 10.1264/jsme2.me11295] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [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] [Indexed: 11/12/2022] Open
Abstract
Acaryochloris spp. are unique cyanobacteria which contain chlorophyll d as the predominant pigment. The phylogenetic diversity of Acaryochloris spp. associated with 7 Prochloron- or Synechocystis-containing didemnid ascidians and 1 Synechococcus-containing sponge obtained from the coast of the Republic of Palau was analyzed; we established a PCR primer set designed to selectively amplify the partial 16S rRNA gene of Acaryochloris spp. even in DNA samples containing a large amount of other cyanobacterial and algal DNAs. Polymerase chain reaction-denaturing gradient gel electrophoresis with this primer set enabled detection of the phyogenetic diversity of Acaryochloris spp. All the ascidian and sponge samples contained Acaryochloris spp. Fourteen phylotypes that were highly homologous (98–100%) with A. marina MBIC11017 were detected, while only 2 phylotypes were detected with our previously developed method for detecting cyanobacteria. The results also revealed that many uncultured phylotypes of Acaryochloris spp. were associated with those didemnid ascidians, since a clonal culture of only 1 phylotype has been established thus far. No specific relationship was found among the Acaryochloris phylotypes and the genera of the ascidians even when sample localities were identical; therefore, these invertebrates may provide a favorable habitat for Acaryochloris spp. rather than hosts showing any specific symbiotic relationships.
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Affiliation(s)
- Satoshi Ohkubo
- Graduate School of Human and Environmental Studies, Kyoto University, Japan
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23
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Ichikawa T, Itagaki N, Loebl N, Maruhn J, Oberacker V, Ohkubo S, Schuetrumpf B, Umar A. Static and Dynamic Chain Structures in the Mean-Field Theory. EPJ Web of Conferences 2011. [DOI: 10.1051/epjconf/20111707002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Abstract
We investigate the linear chain configurations of four-α clusters in 16O using a Skyrme cranked Hartree-Fock method and discuss the relationship between the stability of such states and angular momentum. We show the existence of a region of angular momentum (13-18ℏ) where the linear chain configuration is stabilized. For the first time we demonstrate that stable exotic states with a large moment of inertia (ℏ2/2Θ∼0.06-0.08 MeV) can exist.
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Affiliation(s)
- T Ichikawa
- Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
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25
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Kashiyama Y, Miyashita H, Ohkubo S, Ogawa NO, Chikaraishi Y, Takano Y, Suga H, Toyofuku T, Nomaki H, Kitazato H, Nagata T, Ohkouchi N. Evidence of global chlorophyll d. Science 2008; 321:658. [PMID: 18669855 DOI: 10.1126/science.1158761] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Although analyses of chlorophyll d (Chl d)-dominated oxygenic photosystems have been conducted since their discovery 12 years ago, Chl d distribution in the environment and quantitative importance for aquatic photosynthesis remain to be investigated. We analyzed the pigment compositions of surface sediments and detected Chl d and its derivatives from diverse aquatic environments. Our data show that the viable habitat for Chl d-producing phototrophs extends across salinities of 0 to 50 practical salinity units and temperatures of 1 degrees to 40 degrees C, suggesting that Chl d production can be ubiquitously observed in aquatic environments that receive near-infrared light. The relative abundances of Chl d derivatives over that of Chl a derivatives in the studied samples are up to 4%, further suggesting that Chl d-based photosynthesis plays a quantitatively important role in the aquatic photosynthesis.
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Affiliation(s)
- Y Kashiyama
- Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan.
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26
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Inoue K, Ikeda Y, Yamanaka S, Kumon Y, Ohkubo S, Morita T, Suehiro T, HAshimoto K. SERUM FETUIN-A LEVELS IN PATIENTS WITH RHEUMATOID ARTHRITIS. ATHEROSCLEROSIS SUPP 2008. [DOI: 10.1016/s1567-5688(08)70930-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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Ohkubo S, Miyashita H, Murakami A, Takeyama H, Tsuchiya T, Mimuro M. Molecular detection of epiphytic Acaryochloris spp. on marine macroalgae. Appl Environ Microbiol 2006; 72:7912-5. [PMID: 17028237 PMCID: PMC1694208 DOI: 10.1128/aem.01148-06] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [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: 11/20/2022] Open
Abstract
A molecular method for detecting the epiphyte community on marine macroalgae was developed by using PCR-denaturing gradient gel electrophoresis. Selective amplification of 16S rRNA gene fragments from either cyanobacteria or algal plastids improved the detection of minor epiphytes. Two phylotypes of Acaryochloris, a chlorophyll d-containing cyanobacterium, were found not only on red macroalgae but also on green and brown macroalgae.
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Affiliation(s)
- Satoshi Ohkubo
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
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28
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Watanabe A, Nagaseki Y, Ohkubo S, Ohhashi Y, Horikoshi T, Nishigaya K, Nukui H. Anatomical variations of the ten triangles around the cavernous sinus. Clin Anat 2003; 16:9-14. [PMID: 12486732 DOI: 10.1002/ca.10072] [Citation(s) in RCA: 28] [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] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The dimensions of the 10 triangles around the cavernous sinus were measured to define the anatomical characteristics of the triangles and to compare their consistency in shape and area. Twelve tissue blocks containing the bilateral cavernous sinuses and medial two-thirds of the middle cranial fossae were obtained from Japanese adults at autopsy, fixed to a stereotactic frame, and examined with an operative microscope. The dimensions of each triangle were measured with calipers and compared, based on the same point and border. The anteromedial triangle and the superolateral (Parkinson's) triangle were more consistent in shape than the paramedial and oculomotor triangles, but the oculomotor triangle was larger in area than these other triangles. The posteromedial (Kawase's) triangle was more consistent in shape and larger than the anterolateral, lateral, and the posterolateral (Glasscock's) triangles. The anteromedial and superolateral (Parkinson's) triangles are important for the combined epi- and subdural approach to cavernous sinus lesions. The posteromedial (Kawase's) triangle is important for gaining access to the posterior cranial fossa from the middle cranial fossa.
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Affiliation(s)
- A Watanabe
- Department of Neurosurgery, Yamanashi Medical University, Yamanashi, Japan.
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29
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Abstract
The physical interpretation of nuclear rainbow scattering within the frame of the optical model is critically investigated. Starting from the properties of the Luneburg lens, a gradient index device that displays refractive features similar to those of the nuclear potential, important differences between the mechanisms producing the nuclear and optical rainbows are pointed out.
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Affiliation(s)
- F Michel
- Faculté des Sciences, Université de Mons-Hainaut, Belgium
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30
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Masadome T, Asano Y, Imato T, Ohkubo S, Tobita T, Tabei H, Iwasaki Y, Niwa O, Fushinuki Y. Preparation of refractive index matching polymer film alternative to oil for use in a portable surface-plasmon resonance phenomenon-based chemical sensor method. Anal Bioanal Chem 2002; 373:222-6. [PMID: 12110971 DOI: 10.1007/s00216-002-1329-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2001] [Revised: 04/16/2002] [Accepted: 04/18/2002] [Indexed: 10/27/2022]
Abstract
In order to simplify the procedure for assembling a surface-plasmon resonance (SPR) sensor, a refractive index matching polymer film was prepared as an alternative to the conventionally used matching oil. The refractive index matching polymer film, the refractive index of which was nearly equal to the prism and sensor chip material (a cover glass) of the SPR sensor, was prepared by casting a tetrahydrofuran solution of poly (vinyl chloride) (PVC) containing equal weights of dioctyl phthalate and tricresyl phosphate. The refractive index matching polymer film was found to have a refractive index of 1.516, which is identical to that of the prism and the cover glass used for the present SPR sensor. The utility of the matching polymer film for the SPR sensor was confirmed by the detection of anti-human albumin, based on an antigen-antibody reaction.
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Affiliation(s)
- Takashi Masadome
- Department of Chemical Science and Engineering, Ariake National College of Technology, Omuta, Fukuoka 836-8585, Japan
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31
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Nakanishi H, Matsuoka I, Ono T, Ohkubo S, Nakahata N. Qualitatively different response of isolated rabbit aorta to methylene blue administered from intimal and adventitial surface. Fukushima J Med Sci 2001; 47:63-73. [PMID: 11989620 DOI: 10.5387/fms.47.63] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 11/12/2022] Open
Abstract
An isolated rabbit aortic preparation, on which administered drugs act selectively from intimal or adventitial surface, was made. Epinephrine (0.1 nM approximately 10 microM) produced concentration-dependent increase of intraluminal pressure, which is due to increase of contraction of the vascular smooth muscle. Sensitivity of contractile response to epinephrine administered from intimal surface was significantly higher than that administered from adventitial surface. The contractile response to epinephrine administered from intimal surface was reduced by removal of the endothelium. Cocaine (100 microM) potentiated the contractile response to epinephrine administered from adventitial surface. Cocaine also potentiated the contractile response to high concentration of epinephrine administered from intimal surface, while the drug reduced the contractile response to low concentration of epinephrine. Methylene blue (100 microM) administered from adventitial surface produced a marked contraction, while methylene blue administered from intimal surface produced a marked relaxation. The relaxing response to methylene blue administered from intimal surface was reduced by the removal of endothelium. Prazosin (1 microM) suppressed the contractile response to methylene blue administered from adventitial surface, indicating that methylene blue released norepinephrine from adrenergic nerve terminals. The contractile response to epinephrine administered from intimal surface was reduced by methylene blue administered from intimal surface. The present study clearly demonstrated variation in mechanical response of isolated rabbit aortic preparation with intimal or adventitial surface of drug entry.
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Affiliation(s)
- H Nakanishi
- Fukushima Gakuin Junior College, Fukushima City, Japan
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Ohkubo S, Miyadera K, Sugimoto Y, Matsuo K, Wierzba K, Yamada Y. Substrate phage as a tool to identify novel substrate sequences of proteases. Comb Chem High Throughput Screen 2001; 4:573-83. [PMID: 11562260 DOI: 10.2174/1386207013330788] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [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: 11/22/2022]
Abstract
Combinatorial phage peptide libraries have been used to identify the ligands for specific target molecules. These libraries are also useful for identification of the specific substrates of various proteases. A substrate phage library has a random peptide sequence at the N-terminus of the phage coat protein and an additional tag sequence that enables attachment of the phage to an immobile phase. When these libraries are incubated with a specific enzyme, such as a protease, the uncleaved phage is excluded from the solution with tag-binding macromolecules. This provides a novel approach to define substrate specificity. The aim of this review is to summarize recent progress on the application of the substrate phage technique to identify specific substrates of proteolytic enzymes. As an example, some of our own experimental data on the selection and characterization of substrate sequences for thrombin, a serine protease, and membrane type-1 matrix metalloproteinase (MT1-MMP) will be presented. Using this approach, the canonical consensus substrate sequence for thrombin was deduced from the selected clones. As expected from the collagenolytic activity of MT1-MMP, a collagen-like sequence was identified in the case of MT1-MMP. A more selective substrate sequence for MT1-MMP was identified during a substrate phage screen. The delineation of the substrate specificity of proteases will help to elucidate the enzymatic properties and the physiological roles of these enzymes. Comprehensive screening of very large numbers of potential substrate sequences is possible with substrate phage libraries. Thus, this approach allows novel substrate sequences and previously unknown target molecules to be defined.
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Affiliation(s)
- S Ohkubo
- Cancer Research Laboratory, Hanno Research Center, Taiho Pharmaceutical Co., Ltd., 1-27 Misugi-dai, Hanno, Saitama 357-8527, Japan.
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Onda H, Ohkubo S, Shintani Y, Ogi K, Kikuchi K, Tanaka H, Yamamoto K, Tsuji I, Ishibashi Y, Yamada T, Kitada C, Suzuki N, Sawada H, Nishimura O, Fujino M. A novel secreted tumor antigen with a glycosylphosphatidylinositol-anchored structure ubiquitously expressed in human cancers. Biochem Biophys Res Commun 2001; 285:235-43. [PMID: 11444831 DOI: 10.1006/bbrc.2001.5149] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 12/11/2022]
Abstract
In a search for novel genes expressed in human cancers, we identified one gene from an assembled expressed sequence tag database. Northern blot analysis revealed that the gene, termed alcan, was expressed in various types of human cancer cell lines and in the fetus, but not in normal tissues. The alcan gene is located on chromosome 6 and is encoded on a 246-amino-acid protein with weak homology to classical major histocompatibility complex class I. Its gene product, ALCAN, had hydrophobic amino acid clusters at both the N- and C-terminal regions and was predicted to be a glycosylphosphatidylinositol (GPI)-anchored membrane protein. Flow cytometric analysis revealed that ALCAN was detected on the surface of human cancer cells and on alcan-transfected CHO-K1 cells. ALCAN was also secreted from these cells, suggesting that some portion of the molecules was secreted by enzymatic cleavage by, for example, phospholipases. Mutational analysis of ALCAN suggested that the GPI-anchored position was the Ser(216) residue. These findings indicate that ALCAN may be a potential target for cancer diagnosis or therapy.
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Affiliation(s)
- H Onda
- Discovery Research Laboratories I, Pharmaceutical Research Division, Takeda Chemical Industries, Ltd., 10 Wadai Tsukuba, Ibaraki 300-4293, Japan.
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Ohkubo S, Kumazawa K, Sagawa K, Kimura J, Matsuoka I. Beta,gamma-methylene ATP-induced cAMP formation in C6Bu-1 cells: involvement of local metabolism and subsequent stimulation of adenosine A2B receptor. J Neurochem 2001; 76:872-80. [PMID: 11158259 DOI: 10.1046/j.1471-4159.2001.00098.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [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: 01/07/2023]
Abstract
The mechanism underlying beta,gamma-methylene ATP (beta,gamma-MeATP)-induced cAMP elevation was investigated in rat glioma C6Bu-1 cells. Beta,gamma-MeATP increased forskolin-stimulated cAMP formation in a manner sensitive to both the P1 antagonist xanthine amine congener (XAC) and the P2 antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). Adenosine deaminase (ADA; 1 U/mL), which abolished the adenosine-induced response, did not eliminate the beta,gamma-MeATP-induced response. However, combination of ADA with alpha,beta-methylene ADP (alpha,beta-MeADP), an ecto-5'-nucleotidase inhibitor, blocked the beta,gamma-MeATP-induced response. AMP, the substrate for ecto-5'-nucleotidase, also induced cAMP formation in a manner sensitive to XAC and alpha,beta-MeADP inhibition. However, the AMP-induced response was not blocked by PPADS. HPLC analyses revealed that adenosine was generated from beta,gamma-MeATP and AMP. In addition, alpha,beta-MeADP inhibited the conversion of beta,gamma-MeATP and AMP to adenosine, whereas PPADS blocked adenosine formation from beta,gamma-MeATP but not from AMP. [3H]Adenosine generated from [3H]AMP was preserved on the cell surface environment even in the presence of ADA. The mRNAs for ecto-phosphodiesterase/pyrophosphatase 1 (EC 3.1.4.1), ecto-5'-nucleotidase (EC 3.1.3.5) and adenosine A2B receptor were detected by RT-PCR. These results suggest that C6Bu-1 cells possess ecto-enzymes converting beta,gamma-MeATP to adenosine, and the locally accumulated adenosine in this mechanism efficiently stimulates A2B receptors in a manner resistant to exogenous ADA.
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Affiliation(s)
- S Ohkubo
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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Ohkubo S, Kimura J, Matsuoka I. Correlation between adenine nucleotide-induced cyclic AMP elevation and extracellular adenosine formation in NG108-15 cells. Jpn J Pharmacol 2000; 84:325-33. [PMID: 11138734 DOI: 10.1254/jjp.84.325] [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] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We previously demonstrated that extracellular adenine nucleotides induced cyclic AMP elevation in NG108-15 cells. This response was resistant to adenosine deaminase (ADA) and the ecto-5'-nucleotidase (CD73) inhibitor alpha,beta-methylene ADP (alpha,beta-MeADP), but was inhibited by both P1- and P2-receptor antagonists. In the present study, we investigated the relationship between adenine nucleotide-induced cyclic AMP elevation and extracellular adenosine formation. ATP, AMP and beta,gamma-methylene ATP (beta,gamma-MeATP) were time-dependently metabolized to adenosine in NG108-15 cells. Adenosine formations from ATP, AMP and beta,gamma-MeATP were not affected by alpha,beta-MeADP, but suppressed by the P2-receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). A close correlation between extracellular adenosine formation and cyclic AMP increasing effects were obtained with several adenine nucleotide agonists in NG108-15 cells as well as their parent cell line C6Bu-1 and N18TG-2 cells, all of which possess functional adenosine A2 receptors. When NG108-15 cells were incubated with [3H]ATP or [3H]AMP in the presence of ADA, [3H]adenosine was found to distribute dominantly on the cell surface. NG108-15 cells expressed mRNA for the ecto-ATPase and nucleotide pyrophosphatase, but not for CD73. These results suggest that local adenosine formation by an ecto-enzyme distinct from CD73 is involved in adenine nucleotide-induced cyclic AMP formation in NG108-15 cells.
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Affiliation(s)
- S Ohkubo
- Department of Cellular Signaling, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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Hosoya M, Moriya T, Kawamata Y, Ohkubo S, Fujii R, Matsui H, Shintani Y, Fukusumi S, Habata Y, Hinuma S, Onda H, Nishimura O, Fujino M. Identification and functional characterization of a novel subtype of neuromedin U receptor. J Biol Chem 2000; 275:29528-32. [PMID: 10887190 DOI: 10.1074/jbc.m004261200] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [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: 11/06/2022] Open
Abstract
Neuromedin U is a bioactive peptide isolated originally from the porcine spinal cord. We recently identified neuromedin U as the cognate ligand for the orphan G protein-coupled receptor FM-3. In this study, we isolated cDNA coding for a novel G protein-coupled receptor, TGR-1, which was highly homologous with FM-3. We found that neuromedin U specifically and clearly elevated the extracellular acidification rates, arachidonic acid metabolite release, and intracellular Ca(2+) mobilization in Chinese hamster ovary cells expressing TGR-1. Radiolabeled neuromedin U specifically bound with high affinity to membrane fractions prepared from these cells. These results show that TGR-1, like FM-3, is a specific and functional receptor for neuromedin U. We analyzed TGR-1 mRNA tissue distribution in rats using quantitative reverse transcription-polymerase chain reaction and found it to considerably differ from that of FM-3 mRNA. TGR-1 mRNA was primarily expressed in the uterus, suggesting that TGR-1 mediates the contractile activity of neuromedin U in this tissue. The identification of specific and functional receptor subtypes for neuromedin U will facilitate the study of their physiological roles and the search for their specific agonists and antagonists.
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Affiliation(s)
- M Hosoya
- Pharmaceutical Discovery Research Division, Takeda Chemical Industries, Ltd., Wadai 10, Tsukuba, Ibaraki 300-4293, Japan
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Okamoto M, Ohe G, Oshikawa T, Nishikawa H, Furuichi S, Bando T, Yoshida H, Sakai T, Himeno K, Sato M, Ohkubo S. Purification and characterization of cytokine-inducing protein of seed extract from Aeginetia indica L., a parasitic plant. Immunopharmacology 2000; 49:377-89. [PMID: 10996035 DOI: 10.1016/s0162-3109(00)00253-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have isolated 55 kDa protein from the seed extract of Aeginetia indica L. (AIL), a parasitic plant, by an affinity chromatography on N-hydroxysuccinimide (NHS)-activated Sepharose High Performance column bound F3 monoclonal antibody which neutralizes cytokine-inducing and antitumor effect of AIL. In in vitro model using human peripheral blood mononuclear cells (PBMC), the 55 kDa protein (AILb-A) induced multiple cytokines, such as IFN-gamma, tumor necrosis factor (TNF)-alpha, granulocyte macrophage-colony stimulating factor (GM-CSF), IL-2, IL-6, IL-10, IL-12 and IL-18, and also accelerated killer cell activities of PBMC. When compared with a commonly used immunotherapeutic agent OK-432, AILb-A induced Th1 cytokines are greater than OK-432. Of the Th2 cytokines, the amounts of IL-6 and IL-10 induced by AILb-A were lower than those by OK-432. No significant induction of IL-4 and IL-13 was observed in AILb-A-stimulated PBMC. TNF family including TNF-alpha, TNF-beta, Fas ligand (FasL) and TNF-related apoptosis-inducing ligand (TRAIL) were suggested to be important for AILb-A-induced killing activity of PBMC by reverse transcription-polymerase chain reaction (RT-PCR) analysis. Furthermore, the neutralizing test using cytokine-specific antibodies demonstrated that IL-18 plays a most significant role for IFN-gamma- and killer cell-inducing ability of AILb-A among the cytokines tested. These findings clearly indicated that AILb-A, a 55 kDa protein of AIL, is a potent Th1 cytokine inducer and may be a useful immunotherapeutic agent for the patients with malignancies.
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MESH Headings
- Adjuvants, Immunologic/isolation & purification
- Adjuvants, Immunologic/metabolism
- Adjuvants, Immunologic/pharmacology
- Antibodies, Monoclonal/metabolism
- Caspase 1/metabolism
- Cells, Cultured
- Cytokines/biosynthesis
- Cytokines/immunology
- Cytokines/metabolism
- Enzyme Activation/drug effects
- Humans
- Immune Sera/pharmacology
- Interleukin-18/metabolism
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Lymphocyte Activation/drug effects
- Picibanil/pharmacology
- Plant Proteins/isolation & purification
- Plant Proteins/metabolism
- Plant Proteins/pharmacology
- Seeds/chemistry
- Th1 Cells/immunology
- Th1 Cells/metabolism
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Affiliation(s)
- M Okamoto
- Second Department of Oral and Maxillofacial Surgery, Tokushima University School of Dentistry, 3-18-15 Kuramoto-cho, 7708504, Tokushima, Japan.
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Michel F, Brau F, Reidemeister G, Ohkubo S. Barrier-wave-internal-wave interference and airy minima in 16O16+O elastic scattering. Phys Rev Lett 2000; 85:1823-1826. [PMID: 10970623 DOI: 10.1103/physrevlett.85.1823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2000] [Indexed: 05/23/2023]
Abstract
Taking 16O+16O elastic scattering at 124 MeV as an example, we show that a barrier-wave-internal-wave decomposition of the elastic scattering amplitude provides valuable information on the light heavy-ion interaction and complements the more conventional nearside-farside decomposition. In particular, we show that the Airy minima present in the angular distributions are due to a barrier-wave-internal-wave interference mechanism, which sheds additional light on the exceptional transparency displayed by some light heavy-ion scattering systems. Extension of these ideas to other fields, like atomic and molecular collision physics, could prove rewarding.
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Affiliation(s)
- F Michel
- Faculte des Sciences, Universite de Mons-Hainaut, B-7000 Mons, Belgium
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Kakikawa M, Ohkubo S, Sakate T, Sayama M, Taketo A, Kodaira K. Purification and DNA-binding properties of the cro-type regulatory repressor protein cng encoded by the Lactobacillus plantarum phage phi g1e. Gene 2000; 249:161-9. [PMID: 10831850 DOI: 10.1016/s0378-1119(00)00146-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [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: 10/18/2022]
Abstract
The putative repressor protein Cng (10kDa on an SDS gel) for the lytic pathway of Lactobacillus plantarum phage φg1e was purified using the Escherichia coli Pt7 system, and its DNA-binding ability for the seven operator-like sequences, the GATAC-boxes (Gb1 to Gb7), was investigated in vitro. In gel-shift assays, Cng selectively bound to the DNA fragments containing the GATAC-box(es). In addition, DNase I footprinting analysis with supercoiled DNA demonstrated that Cng can specifically cover about a 25bp region centered around each of the GATAC-boxes, although two boxes, Gb4 and Gb6, were only partially protected. Moreover, protein crosslinking experiments using glutaraldehyde suggested that Cng most likely functions as a dimer. On the other hand, the binding ability of Cpg for the GATAC-boxes in supercoiled DNA was also examined under the same conditions as in Cng; unlike Cng, Cpg covered Gb4 and Gb6 completely sufficiently as well as the other five boxes. Thus, the present and previous [Kakikawa et al., Gene 215 (1998) 371-379; 242 (2000) 155-166] results indicate a possibility that the two proteins Cng and Cpg selectively bind to the GATAC-boxes that act as operators, and can decide between the lytic or lysogenic pathways through repression of the promoter activity of P(R) as well as P(L).
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Affiliation(s)
- M Kakikawa
- Molecular Biology Group, Toyama University, Gofuku, Japan
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Ohkubo S, Nakanishi H, Kimura J, Matsuoka I. Effects of AMP derivatives on cyclic AMP levels in NG108-15 cells. Br J Pharmacol 2000; 129:1244-50. [PMID: 10725274 PMCID: PMC1571947 DOI: 10.1038/sj.bjp.0703168] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [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] [Received: 05/28/1999] [Revised: 11/01/1999] [Accepted: 12/17/1999] [Indexed: 11/10/2022] Open
Abstract
1. In NG108-15 neuroblastomaxglioma hybrid cells, ATP stimulates intracellular cyclic AMP formation, which is inhibited by both adenosine (P(1)) and P2 receptor antagonists. In the present study, we examined the effects of several AMP derivatives in NG108-15 cells and mouse neuroblastoma N18TG-2 cells. 2. Adenosine 2'-monophosphate (A2P), adenosine 3'-monophosphate (A3P) and adenosine 5'-phosphosulphate (A5PS) increased cyclic AMP levels with similar concentration-dependencies in NG108-15 cells. 3. Increases in cyclic AMP by AMP derivatives were inhibited by the P2 receptor antagonist PPADS, but not by suramin. Effects of AMP derivatives were also inhibited by P(1) receptor antagonists ZM241385, XAC, DPCPX and partially by alloxazine. The ecto-nucleotidase inhibitor alpha, beta-methyleneADP was without effect. 4. In contrast, AMP derivatives did not change cyclic AMP levels in N18TG-2 cells. Accumulation of cyclic AMP in N18TG-2 cells was stimulated by adenosine A(2) receptor agonists CGS21680 and NECA, but not by ATP or beta, gamma-methyleneATP, agonists for cyclic AMP production in NG108-15 cells. 5. Reverse transcription-coupled polymerase chain reaction (RT - PCR) analyses revealed that N18TG-2 cells express both A(2A) and A(2B) receptors, while NG108-15 cells express mainly A(2A) receptors. 6. AMP derivatives did not affect the P2X and P2Y receptors expressed in NG108-15 cells. 7. These results suggest that A2P, A3P and A5PS act as agonists for cyclic AMP production and that these compounds are valuable tools for determinating the mechanism of ATP-stimulated cyclic AMP response in NG108-15 cells.
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Affiliation(s)
- S Ohkubo
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Fukushima 960-1295, Japan.
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Kakikawa M, Ohkubo S, Syama M, Taketo A, Kodaira KI. The genetic switch for the regulatory pathway of Lactobacillus plantarum phage (phi)g1e: characterization of the promoter P(L), the repressor gene cpg, and the cpg-encoded protein Cpg in Escherichia coli. Gene 2000; 242:155-66. [PMID: 10721708 DOI: 10.1016/s0378-1119(99)00531-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [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: 10/18/2022]
Abstract
The structural and functional features of the approximately 530 bp P(L)/Gb5-Gb6-cpg-Gb7 region (P(L) overlaps Gb5) for the lysogenic pathway of L. plantarum phage (phi)gle were investigated using the cat gene of E. coli plasmid pKK232-8 as a reporter. In E. coli XL1-Blue, a recombinant plasmid pKPL2 (cat under P(L)/Gb5-Gb6) exhibited distinct CAT activity, whereas the activity of pKPLCP1 (cat under P(L)/Gb5-Gb6-cpg) was only marginal. When pKPL2 was coexistent with a compatible derivative of plasmid pACYC177 carrying P(L)/Gb5-Gb6-cpg, the CAT activity was declined to the level of pKPLCP1. On the other hand, the cpg-encoded protein Cpg was overproduced in E. coli under P(T7). The molecular mass of the purified Cpg (14.5 kDa on a SDS gel) corresponded well with that (15.1 kDa) predicted from the DNA sequence. Gel-shift and footprinting assays demonstrated that Cpg selectively binds to about 25 bp bases centered around the GATAC-box (from 1 to 7). Moreover, protein crosslinking experiments using glutaraldehyde showed that Cpg most likely functions as a dimeric form. Thus, the present results indicate that Cpg probably represses P(L) through binding to the operator GATAC-box(es), and the P(L)/cpg region might participate in the lysogenic pathway.
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Affiliation(s)
- M Kakikawa
- Molecular Biology Group, Faculty of Engineering, Toyama University, Japan
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Ohkubo S, Kimura J, Nakanishi H, Matsuoka I. Effects of P(1) and P2 receptor antagonists on beta, gamma-methyleneATP- and CGS21680-induced cyclic AMP formation in NG108-15 cells. Br J Pharmacol 2000; 129:291-8. [PMID: 10694235 PMCID: PMC1571837 DOI: 10.1038/sj.bjp.0703053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 11/08/2022] Open
Abstract
1. We have previously shown that ATP increased cyclic AMP in NG108-15 cells, which was inhibited by P(1) receptor antagonist methylxanthines. In the present study, we examined the effects of P(1) and P2 receptor antagonists on cyclic AMP formation induced by beta,gamma-methyleneATP (beta,gamma-MeATP) and CGS21680, an A(2A) adenosine receptor agonist, in NG108-15 cells. 2. beta,gamma-MeATP and CGS21680 increased intracellular cyclic AMP with EC(50) values of 8. 0+/-0.98 microM (n=4) and 42+/-7.5 nM (n=4), respectively. 3. Several P(1) receptor antagonists inhibited both beta,gamma-MeATP- and CGS21680-induced cyclic AMP increase with a similar rank order of potency; ZM241385>CGS15943>XAC>DPCPX. However, the pK(i) values of these antagonists for beta,gamma-MeATP were larger than those for CGS21680. 4. Alloxazine, a P(1) receptor antagonist, and several P2 receptor antagonists (PPADS, iPPADS, reactive blue-2) inhibited beta, gamma-MeATP-induced response, while these antagonists little affected CGS21680-induced one. Suramin was effective only for beta, gamma-MeATP-induced response at 1 mM. 5. 2-chloroadenosine (2CADO) and 2-chloroATP (2ClATP) increased cyclic AMP with similar potencies. The effects of these agonists were both inhibited by ZM241385, but only 2ClATP-induced response was inhibited by PPADS. 6. ATP- and beta, gamma-MeATP-induced responses were little affected by alpha, beta-methyleneADP, a 5'-nucleotidase inhibitor. 7. These results clearly demonstrate that ATP-stimulated cyclic AMP formation can be distinguished from the A(2A) receptor agonist-induced one by using the several P(1) and P2 receptor antagonists.
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Affiliation(s)
- S Ohkubo
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Hikarigaoka 1, Fukushima 960-1295, Japan.
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Ohkubo S, Miyadera K, Sugimoto Y, Matsuo K, Wierzba K, Yamada Y. Identification of substrate sequences for membrane type-1 matrix metalloproteinase using bacteriophage peptide display library. Biochem Biophys Res Commun 1999; 266:308-13. [PMID: 10600499 DOI: 10.1006/bbrc.1999.1816] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [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: 11/22/2022]
Abstract
Membrane type-1 matrix metalloproteinase (MT1-MMP) has been reported to mediate the activation of progelatinase A (proMMP-2) which is associated with tumor invasion and metastasis, and also known to have an ability to digest extracellular matrix components. To clarify substrate specificity of MT1-MMP, we have searched for amino acid sequences cleaved by this protease using the hexamer substrate phage library consisting of a large number of randomized amino acids sequences. The consensus substrate sequences for MT1-MMP were deduced from the selected clones and appeared to be P-X-G/P-L at the P3-P1' sites. Peptide cleavage assay revealed that MT1-MMP preferentially digested a synthetic substrate containing Pro of the P1 position compared to that being substituted with Gly. Our results may have an important implication to identifying new target proteins for MT1-MMP and leading to the design of its selective inhibitors suitable for cancer chemotherapy.
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Affiliation(s)
- S Ohkubo
- Hanno Research Center, Taiho Pharmaceutical Company, Ltd., 1-27 Misugi-dai, Hanno, Saitama, 357-8527, Japan.
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Abstract
Maitotoxin (MTX), a Ca2+ channel-activating marine toxin, caused shape change followed by aggregation in rabbit platelets, like U46619, a thromboxane A2 analogue. Although both drugs failed to cause aggregation in the absence of external Ca2+, U46619, but not maitotoxin, elicited shape change in the absence of external Ca2+. The observations of platelets with a scanning electron microscope showed that both drugs caused contraction of platelets and extension of pseudopodia (shape change) followed by aggregation with a clot in the presence of Ca2+. It is noteworthy that long term exposure to MTX caused the lysis of platelets in the presence of Ca2+. While U46619 transiently increased the internal Ca2+ concentration ([Ca2+]i), maitotoxin slowly but irreversibly increased [Ca2+]i in an external Ca2(+)-dependent manner. MTX-induced phosphoinositide hydrolysis was totally dependent on the presence of external Ca2+, but U46619-induced phosphoinositide hydrolysis was still observed in the absence of external Ca2+. MTX-induced phosphoinositide hydrolysis was partly inhibited by SK&F96365, a voltage-independent Ca2+ channel antagonist, or by genistein, a tyrosine kinase inhibitor. MTX caused phosphorylation of tyrosine residues of several proteins, like U46619. Thus, MTX is similar to U46619 in functions of Ca2+ mobilization, phosphoinositide hydrolysis and tyrosine phosphorylation, but MTX-induced actions are strictly dependent on the presence of external Ca2+.
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Affiliation(s)
- N Nakahata
- Department of Pharmaceutical Molecular Biology, Faculty of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
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Sakata H, Kouhara T, Takeda M, Yamada A, Ohkubo S, Sasaoka Y, Tashiro M. Measles outbreak in a junior high school in November-December 1998. Jpn J Infect Dis 1999; 52:172-3. [PMID: 10592902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Affiliation(s)
- H Sakata
- Department of Viral Disease and Vaccine Control, National Institute of Infectious Diseases, Tokyo.
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Ono T, Matsuoka I, Ohkubo S, Kimura J, Nakanishi H. Effects of YT-146 [2-(1-octynyl) adenosine], an adenosine A2A receptor agonist, on cAMP production and noradrenaline release in PC12 cells. Jpn J Pharmacol 1998; 78:269-77. [PMID: 9869260 DOI: 10.1254/jjp.78.269] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Effects of YT-146 [2-(1-octynyl) adenosine], an adenosine A2 receptor agonist, on cAMP production and noradrenaline (NA) release were investigated in PC12 cells. YT-146 caused a concentration-dependent cAMP accumulation (EC50: 1.2+/-0.9 nM). In [3H]NA-prelabeled cells, YT-146 increased the basal NA release and enhanced ATP-evoked NA release in a concentration-dependent manner (EC50: 0.23+/-0.15 nM). YT-146 augmented the maximal response to ATP without affecting the EC50 value of ATP. These effects of YT-146 were inhibited by several adenosine receptor antagonists with a characteristic of adenosine A2A receptor subtype. The effects of YT-146 were mimicked by forskolin, dibutylyl cAMP and Sp-cAMPS, and inhibited by H-89, a cAMP-dependent protein kinase inhibitor. YT-146 had little effect on ATP-induced increase in intracellular Ca2+ concentration. YT-146 enhanced the NA release induced by several different stimuli including Ca2+ ionophore A23187. The present results suggest that YT-146 is a potent agonist on adenosine A2A receptors in PC12 cells and causes a cAMP-dependent enhancement of NA release by affecting the exocytosis process at a point downstream of the intracellular Ca2+ increase.
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Affiliation(s)
- T Ono
- Department of Pharmacology, Fukushima Medical College, Japan
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Ohkubo S, Matsuoka I, Kimura J, Nakanishi H. Inhibition of ATP-induced cAMP formation by 5'-p-fluorosulfonylbenzoyladenosine in NG108-15 cells. Naunyn Schmiedebergs Arch Pharmacol 1998; 358:153-9. [PMID: 9749999 DOI: 10.1007/pl00005237] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
ATP is known to increase intracellular cAMP levels in NG108-15 cells via a novel purinoceptor and this response is inhibited by the P1 purinoceptor antagonist methylxanthine. In the present study, we examined the effects of 5'-p-fluorosulfonylbenzoyladenosine (FSBA), an affinity ligand for ATP-binding proteins, on cAMP formation mediated by activation of adenylate cyclase (AC)-linked purinoceptors in NG108-15 cells. cAMP levels were determined by RIA using an anti-succinyl-cAMP antiserum. FSBA (100 microM) increased intracellular cAMP about 2.6-fold. However, FSBA-induced cAMP formation was abolished by pretreatment with adenosine deaminase, suggesting that adenosine, a breakdown product of FSBA, is involved in FSBA-induced cAMP formation. In contrast, pretreatment of cells with FSBA in the presence of adenosine deaminase inhibited cAMP formation induced by ATP and beta,gamma-methylene-ATP (beta,gamma-MeATP), without affecting the prostaglandin E1 (PGE1)-induced response. The inhibitory effect of FSBA on ATP-induced cAMP formation was concentration-dependent with a concentration required for half-maximal inhibition (IC50) of around 3 microM. The inhibitory effect of FSBA was not affected by pertussis toxin (PTX)-treatment. Pretreatment with FSBA (10 microM) depressed the maximal response to beta,gamma-MeATP by 60%, but did not affect the response to 5'-N-ethylcarboxamidoadenosine. The inhibitory effect of FSBA (100 microM) increased time-dependently during pretreatment and partly resisted wash-out. The inhibition by FSBA was protected by simultaneous addition of beta,gamma-MeATP during the FSBA pretreatment, indicating that both FSBA and the ATP analogue interacted with the same receptor site. The pretreatment with FSBA did not affect the increase in [Ca2+]i induced by ATP, UTP or benzoylbenzoic ATP. These results suggest that FSBA inhibits cAMP accumulation induced in NG108-15 cells by ATP or related agonists by selective modification of an AC-linked purinoceptor.
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MESH Headings
- Adenosine/analogs & derivatives
- Adenosine/metabolism
- Adenosine/pharmacology
- Adenosine Triphosphate/analogs & derivatives
- Adenosine Triphosphate/metabolism
- Adenosine Triphosphate/pharmacology
- Adenylate Cyclase Toxin
- Affinity Labels/metabolism
- Affinity Labels/pharmacology
- Animals
- Binding, Competitive
- Calcium/metabolism
- Cyclic AMP/metabolism
- Dose-Response Relationship, Drug
- Hybrid Cells/cytology
- Hybrid Cells/drug effects
- Hybrid Cells/metabolism
- Pertussis Toxin
- Protein Binding
- Purinergic P2 Receptor Agonists
- Receptors, Purinergic/metabolism
- Receptors, Purinergic/physiology
- Receptors, Purinergic P2X7
- Receptors, Purinergic P2Y2
- Tumor Cells, Cultured/cytology
- Tumor Cells, Cultured/drug effects
- Tumor Cells, Cultured/metabolism
- Uridine Triphosphate/pharmacology
- Virulence Factors, Bordetella/pharmacology
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Affiliation(s)
- S Ohkubo
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Hikarigaoka, Japan
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Ohishi K, Kamata H, Ohkubo S, Yamanouchi K, Kai C. Construction of recombinant vaccinia virus expressing Rinderpest Virus nucleocapsid protein and its immunogenicity in mice. J Vet Med Sci 1998; 60:655-6. [PMID: 9637306 DOI: 10.1292/jvms.60.655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 11/22/2022] Open
Abstract
Recombinant vaccinia virus (rVV) was constructed by inserting Rinderpest Virus (RPV) nucleocapsid (N) protein gene. The rVV expressed RPV-N protein in the rVV-infected cells. The rVV was shown to produce RPV-N-specific antibody in mice.
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Affiliation(s)
- K Ohishi
- Nippon Institute for Biological Science, Tokyo, Japan
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Oguchi S, Saida T, Koganehira Y, Ohkubo S, Ishihara Y, Kawachi S. Characteristic epiluminescent microscopic features of early malignant melanoma on glabrous skin. A videomicroscopic analysis. Arch Dermatol 1998; 134:563-8. [PMID: 9606325 DOI: 10.1001/archderm.134.5.563] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To investigate the characteristic epiluminescent microscopic features of early lesions of malignant melanoma affecting glabrous skin, which is the most prevalent site of the neoplasm in nonwhite populations. DESIGN The epiluminescent microscopic features of various kinds of melanocytic lesions affecting glabrous skin were investigated using a videomicroscope. All the diagnoses were determined clinically and histopathologically using the standard criteria. SETTING A dermatology clinic at a university hospital. PATIENTS The following 130 melanocytic lesions consecutively diagnosed at our department were examined: 16 lesions of acral lentiginous melanoma, 6 lesions of malignant melanoma in situ, and 108 lesions of benign melanocytic nevus (acquired or congenital). MAIN OUTCOME MEASURE The incidence of each characteristic epiluminescent feature was compared among disease categories. RESULTS On epiluminescent microscopy, malignant melanoma in situ and the macular portions of invasive malignant melanoma showed accentuated pigmentation on the ridges of the skin markings, which are arranged in parallel patterns on glabrous skin. This "parallel ridge pattern" was found in 5 (83%) of 6 lesions of malignant melanoma in situ and in 15 (94%) of 16 lesions of malignant melanoma. The parallel ridge pattern was rarely found in the lesions of benign melanocytic nevus. Most benign melanocytic nevi showed 1 of the following 3 typical epiluminescent patterns: (1) a parallel furrow pattern exhibiting pigmentation on the parallel sulci of [he skin markings (54%), (2) a latticelike pattern (21%), and (3) a fibrillar pattern showing filamentous or meshlike pigmentation (15%). The remaining 11 benign nevi (10%) showed a nontypical pattern. CONCLUSION Because epiluminescent microscopic features of early malignant melanoma on glabrous skin are characteristic, we can effectively detect early lesions using this noninvasive method.
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Affiliation(s)
- S Oguchi
- Department of Dermatology, Shinshi University School of Medicine, Matsumoto, Japan
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Affiliation(s)
- A Nambu
- Department of Radiology, Yamanashi Medical College, Nakakoma-gun, Japan
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