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Shimizu Y, Tamiya-Koizumi K, Tsutsumi T, Kyogashima M, Kannagi R, Iwaki S, Aoyama M, Tokumura A. Hypoxia increases cellular levels of phosphatidic acid and lysophospholipids in undifferentiated Caco-2 cells. Lipids 2023; 58:93-103. [PMID: 36708255 DOI: 10.1002/lipd.12366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/29/2023]
Abstract
Cancer cells are known to survive in a hypoxic microenvironment by altering their lipid metabolism as well as their energy metabolism. In this study, Caco-2 cells derived from human colon cancer, were found to have elevated intracellular levels of phosphatidic acid and its lysoform, lysophosphatidic acid (LPA), under hypoxic conditions. Our results suggested that the elevation of LPA in Caco-2 cells was mainly due to the combined increases in cellular levels of lysophosphatidylcholine and lysophosphatidylethanolamine by phospholipase A2 and subsequent hydrolysis to LPA by lysophospholipase D. We detected the Ca2+ -stimulated choline-producing activities toward exogenous lysophosphatidylcholines in whole Caco-2 cell homogenates, indicating their involvement in the LPA production in intact Caco-2 cells.
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Affiliation(s)
- Yoshibumi Shimizu
- Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan
| | - Keiko Tamiya-Koizumi
- Department of Pathobiology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Toshihiko Tsutsumi
- Graduate School of Clinical Pharmacy, Kyushu University of Health and Welfare, Nobeoka, Japan
| | - Mamoru Kyogashima
- Department of Microbiology and Molecular Cell Biology, Nihon Pharmaceutical University, Saitama, Japan
| | - Reiji Kannagi
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Soichiro Iwaki
- Department of Pathobiology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Mineyoshi Aoyama
- Department of Pathobiology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Akira Tokumura
- Graduate School of Biomedical Sciences, Tokushima University, Tokushima, Japan.,Department of Pharmacy, Yasuda Women's University, Hiroshima, Japan
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2
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Tamiya-Koizumi K, Otoki Y, Nakagawa K, Kannagi R, Mizutani N, Suzuki M, Kyogashima M, Iwaki S, Aoyama M, Murate T, Kitatani K, Kuga T, Mizutani Y, Tokumura A. Cellular concentrations of plasmalogen species containing a polyunsaturated fatty acid significantly increase under hypoxia in human colorectal cancer, Caco2 cells. Biochem Biophys Res Commun 2022; 611:1-7. [DOI: 10.1016/j.bbrc.2022.04.061] [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] [Received: 04/06/2022] [Accepted: 04/13/2022] [Indexed: 11/02/2022]
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3
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Suzuki M, Cao K, Kato S, Mizutani N, Tanaka K, Arima C, Tai MC, Nakatani N, Yanagisawa K, Takeuchi T, Shi H, Mizutani Y, Niimi A, Taniguchi T, Fukui T, Yokoi K, Wakahara K, Hasegawa Y, Mizutani Y, Iwaki S, Fujii S, Satou A, Tamiya-Koizumi K, Murate T, Kyogashima M, Tomida S, Takahashi T. CERS6 required for cell migration and metastasis in lung cancer. J Cell Mol Med 2020; 24:11949-11959. [PMID: 32902157 PMCID: PMC7579715 DOI: 10.1111/jcmm.15817] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/19/2020] [Accepted: 07/30/2020] [Indexed: 02/01/2023] Open
Abstract
Sphingolipids constitute a class of bio‐reactive molecules that transmit signals and exhibit a variety of physical properties in various cell types, though their functions in cancer pathogenesis have yet to be elucidated. Analyses of gene expression profiles of clinical specimens and a panel of cell lines revealed that the ceramide synthase gene CERS6 was overexpressed in non–small‐cell lung cancer (NSCLC) tissues, while elevated expression was shown to be associated with poor prognosis and lymph node metastasis. NSCLC profile and in vitro luciferase analysis results suggested that CERS6 overexpression is promoted, at least in part, by reduced miR‐101 expression. Under a reduced CERS6 expression condition, the ceramide profile became altered, which was determined to be associated with decreased cell migration and invasion activities in vitro. Furthermore, CERS6 knockdown suppressed RAC1‐positive lamellipodia/ruffling formation and attenuated lung metastasis efficiency in mice, while forced expression of CERS6 resulted in an opposite phenotype in examined cell lines. Based on these findings, we consider that ceramide synthesis by CERS6 has important roles in lung cancer migration and metastasis.
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Affiliation(s)
- Motoshi Suzuki
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan.,Department of Molecular Oncology, Fujita Health University, Toyoake, Japan
| | - Ke Cao
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Seiichi Kato
- Department of Pathology and Laboratory Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Naoki Mizutani
- Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Nagoya, Japan
| | - Kouji Tanaka
- Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Nagoya, Japan
| | - Chinatsu Arima
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mei Chee Tai
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Norie Nakatani
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kiyoshi Yanagisawa
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Toshiyuki Takeuchi
- Department of Molecular Oncology, Fujita Health University, Toyoake, Japan
| | - Hanxiao Shi
- Department of Molecular Oncology, Fujita Health University, Toyoake, Japan
| | - Yasuyoshi Mizutani
- Department of Molecular Oncology, Fujita Health University, Toyoake, Japan
| | - Atsuko Niimi
- Department of Molecular Oncology, Fujita Health University, Toyoake, Japan
| | - Tetsuo Taniguchi
- Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takayuki Fukui
- Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Kohei Yokoi
- Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Keiko Wakahara
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshinori Hasegawa
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukiko Mizutani
- Laboratory of Biomembrane and Biofunctional Chemistry, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Soichiro Iwaki
- Department of Molecular and Cellular Pathobiology and Therapeutics, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Satoshi Fujii
- Department of Molecular and Cellular Pathobiology and Therapeutics, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Akira Satou
- Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Nagoya, Japan
| | - Keiko Tamiya-Koizumi
- Department of Molecular and Cellular Pathobiology and Therapeutics, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Takashi Murate
- Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Nagoya, Japan
| | - Mamoru Kyogashima
- Division of Microbiology and Molecular Cell Biology, Nihon Pharmaceutical University, Saitama, Japan
| | - Shuta Tomida
- Department of Biobank, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takashi Takahashi
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
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4
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Suzuki M, Cao K, Kato S, Komizu Y, Mizutani N, Tanaka K, Arima C, Tai MC, Yanagisawa K, Togawa N, Shiraishi T, Usami N, Taniguchi T, Fukui T, Yokoi K, Wakahara K, Hasegawa Y, Mizutani Y, Igarashi Y, Inokuchi JI, Iwaki S, Fujii S, Satou A, Matsumoto Y, Ueoka R, Tamiya-Koizumi K, Murate T, Nakamura M, Kyogashima M, Takahashi T. Targeting ceramide synthase 6-dependent metastasis-prone phenotype in lung cancer cells. J Clin Invest 2019; 129:5050. [PMID: 31674925 DOI: 10.1172/jci133806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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5
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Suzuki M, Cao K, Kato S, Komizu Y, Mizutani N, Tanaka K, Arima C, Tai MC, Yanagisawa K, Togawa N, Shiraishi T, Usami N, Taniguchi T, Fukui T, Yokoi K, Wakahara K, Hasegawa Y, Mizutani Y, Igarashi Y, Inokuchi JI, Iwaki S, Fujii S, Satou A, Matsumoto Y, Ueoka R, Tamiya-Koizumi K, Murate T, Nakamura M, Kyogashima M, Takahashi T. Targeting ceramide synthase 6-dependent metastasis-prone phenotype in lung cancer cells. J Clin Invest 2019; 129:3464. [PMID: 31264973 DOI: 10.1172/jci131245] [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: 11/17/2022] Open
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6
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Mizutani N, Omori Y, Tanaka K, Ito H, Takagi A, Kojima T, Nakatochi M, Ogiso H, Kawamoto Y, Nakamura M, Suzuki M, Kyogashima M, Tamiya-Koizumi K, Nozawa Y, Murate T. Increased SPHK2 Transcription of Human Colon Cancer Cells in Serum-Depleted Culture: The Involvement of CREB Transcription Factor. J Cell Biochem 2016; 116:2227-38. [PMID: 25808826 DOI: 10.1002/jcb.25173] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/20/2015] [Indexed: 02/05/2023]
Abstract
Sphingosine kinases (SPHK) are important to determine cells' fate by producing sphingosine 1-phosphate. Reportedly, exogenous SPHK2 overexpression induces cell cycle arrest or cell death. However, the regulatory mechanism of SPHK2 expression has not been fully elucidated. Here, we analyzed this issue using human colon cancer cell lines under various stress conditions. Serum depletion (FCS(-)) but not hypoxia and glucose depletion increased mRNA, protein and enzyme activity of SPHK2 but not SPHK1. In HCT116 cells mostly used, SPHK2 activity was predominant over SPHK1, and serum depletion increased both nuclear and cytoplasmic SPHK2 activity. Based on previous reports analyzing cellular response after serum depletion, the temporal changes of intracellular signaling molecules and candidate transcription factors for SPHK2 were examined using serum-depleted HCT116 cells, and performed transfection experiments with siRNA or cDNA of candidate transcription factors. Results showed that the rapid and transient JNK activation followed by CREB activation was the major regulator of increased SPHK2 transcription in FCS(-) culture. EMSA and ChIP assay confirmed the direct binding of activated CREB to the CREB binding site of 5' SPHK2 promoter region. Colon cancer cells examined continued to grow in FCS(-) culture, although mildly, while hypoxia and glucose depletion suppressed cell proliferation or induced cell death, suggesting the different role of SPHK2 in different stress conditions. Because of the unique relationship observed after serum depletion, we examined effects of siRNA for SPHK2, and found the role of SPHK2 as a growth or survival factor but not a cell proliferation inhibitor in FCS(-) culture.
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Affiliation(s)
- Naoki Mizutani
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukari Omori
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koji Tanaka
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiromi Ito
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akira Takagi
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tetsuhito Kojima
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahiro Nakatochi
- Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya, Japan
| | - Hideo Ogiso
- Department of Hematology, Kanazawa Medical University, Kanazawa, Japan
| | | | - Mitsuhiro Nakamura
- Department of Drug Information, Gifu Pharmaceutical University, Gifu, Japan
| | - Motoshi Suzuki
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mamoru Kyogashima
- Department of Microbiology and Molecular Biology, Nihon Pharmaceutical University, Saitama, Japan
| | - Keiko Tamiya-Koizumi
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | | | - Takashi Murate
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
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7
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Mizutani N, Omori Y, Kawamoto Y, Sobue S, Ichihara M, Suzuki M, Kyogashima M, Nakamura M, Tamiya-Koizumi K, Nozawa Y, Murate T. Resveratrol-induced transcriptional up-regulation of ASMase (SMPD1) of human leukemia and cancer cells. Biochem Biophys Res Commun 2016; 470:851-6. [PMID: 26809095 DOI: 10.1016/j.bbrc.2016.01.134] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [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: 01/15/2016] [Accepted: 01/21/2016] [Indexed: 11/18/2022]
Abstract
Resveratrol (RSV) is a plant-derived phytoalexin present in plants, whose pleiotropic effects for health benefits have been previously reported. Its anti-cancer activity is among the current topics for novel cancer treatment. Here, effects of RSV on cell proliferation and the sphingolipid metabolism of K562, a human leukemia cell line, were analyzed. Some experiments were also performed in HCT116, a human colon cancer cell line. RSV inhibited cell proliferation of both cell lines. Increased cellular ceramide and decreased sphingomyelin and S1P by RSV were observed in RSV-treated K562 cells. Further analysis revealed that acid sphingomyelinase mRNA and enzyme activity levels were increased by RSV. Desipramine, a functional ASMase inhibitor, prevented RSV-induced ceramide increase. RSV increased ATF3, EGR1, EGR3 proteins and phosphorylated c-Jun and FOXO3. However, co-transfection using these transcription factor expression vectors and ASMase promoter reporter vector revealed positive effects of EGR1 and EGR3 but not others. Electrophoresis mobility shift assay (EMSA) and Chromatin immunoprecipitation (ChIP) assay demonstrated the direct binding of EGR1/3 transcription factors with ASMase 5'-promoter. These results indicate that increased EGR1/3 and ASMase expression play an important role in cellular ceramide increase by RSV treatment.
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Affiliation(s)
- Naoki Mizutani
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan; College of Life and Health Sciences, Chubu University, Kasugai, Japan
| | - Yukari Omori
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | | | - Sayaka Sobue
- College of Life and Health Sciences, Chubu University, Kasugai, Japan
| | | | - Motoshi Suzuki
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mamoru Kyogashima
- Department of Microbiology and Molecular Biology, Nihon Pharmaceutical University, Saitama, Japan
| | - Mitsuhiro Nakamura
- Department of Drug Information, Gifu Pharmaceutical University, Gifu, Japan
| | | | | | - Takashi Murate
- College of Life and Health Sciences, Chubu University, Kasugai, Japan.
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8
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Suzuki M, Cao K, Kato S, Komizu Y, Mizutani N, Tanaka K, Arima C, Tai MC, Yanagisawa K, Togawa N, Shiraishi T, Usami N, Taniguchi T, Fukui T, Yokoi K, Wakahara K, Hasegawa Y, Mizutani Y, Igarashi Y, Inokuchi JI, Iwaki S, Fujii S, Satou A, Matsumoto Y, Ueoka R, Tamiya-Koizumi K, Murate T, Nakamura M, Kyogashima M, Takahashi T. Targeting ceramide synthase 6-dependent metastasis-prone phenotype in lung cancer cells. J Clin Invest 2015; 126:254-65. [PMID: 26650179 DOI: 10.1172/jci79775] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/03/2015] [Indexed: 01/28/2023] Open
Abstract
Sphingolipids make up a family of molecules associated with an array of biological functions, including cell death and migration. Sphingolipids are often altered in cancer, though how these alterations lead to tumor formation and progression is largely unknown. Here, we analyzed non-small-cell lung cancer (NSCLC) specimens and cell lines and determined that ceramide synthase 6 (CERS6) is markedly overexpressed compared with controls. Elevated CERS6 expression was due in part to reduction of microRNA-101 (miR-101) and was associated with increased invasion and poor prognosis. CERS6 knockdown in NSCLC cells altered the ceramide profile, resulting in decreased cell migration and invasion in vitro, and decreased the frequency of RAC1-positive lamellipodia formation while CERS6 overexpression promoted it. In murine models, CERS6 knockdown in transplanted NSCLC cells attenuated lung metastasis. Furthermore, combined treatment with l-α-dimyristoylphosphatidylcholine liposome and the glucosylceramide synthase inhibitor D-PDMP induced cell death in association with ceramide accumulation and promoted cancer cell apoptosis and tumor regression in murine models. Together, these results indicate that CERS6-dependent ceramide synthesis and maintenance of ceramide in the cellular membrane are essential for lamellipodia formation and metastasis. Moreover, these results suggest that targeting this homeostasis has potential as a therapeutic strategy for CERS6-overexpressing NSCLC.
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9
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Mizutani N, Inoue M, Omori Y, Ito H, Tamiya-Koizumi K, Takagi A, Kojima T, Nakamura M, Iwaki S, Nakatochi M, Suzuki M, Nozawa Y, Murate T. Increased acid ceramidase expression depends on upregulation of androgen-dependent deubiquitinases, USP2, in a human prostate cancer cell line, LNCaP. J Biochem 2015; 158:309-19. [PMID: 25888580 DOI: 10.1093/jb/mvv039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 03/25/2015] [Indexed: 01/03/2023] Open
Abstract
Acid ceramidase (ACDase) metabolizes ceramide to sphingosine, leading to sphingosine 1-phosphate production. Reportedly, ACDase has been upregulated in prostate cancer. However, its regulatory mechanism remains unclear. LNCaP (androgen-sensitive prostate cancer cell line) but not PC3 and DU-145, (androgen-unresponsive cell lines) exhibited the highest ACDase protein. Among three cell lines, ASAH1 mRNA level was not correlated with ACDase protein expression, and the 5'-promoter activity did not show androgen dependency, suggesting the post-transcriptional regulation of ACDase in LNCaP cells. Based on these results, LNCaP was analysed further. Casodex, androgen receptor antagonist, and charcoal-stripped FCS (CS-FCS) decreased ACDase protein and activity, whereas dihydrotestosterone in CS-FCS culture increased ACDase protein and enzyme activity. MG132, a proteasome inhibitor, prevented the decrease of ACDase protein when cultured in CS-FCS, suggesting the involvement of ubiquitin/proteasome system. Reportedly, USP2, a deubiquitinase, plays an important role in LNCaP cells. USP2 siRNA decreased ACDase protein, whereas USP2 overexpression increased ACDase protein of LNCaP cells. However, SKP2, an ubiquitin E3 ligase known to be active in prostate cancer, did not affect androgen-dependent ACDase expression in LNCaP cells. Thus, ACDase regulation by androgen in androgen-sensitive LNCaP cells is mainly due to its prolonged protein half-life by androgen-stimulated USP2 expression.
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Affiliation(s)
- Naoki Mizutani
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Minami Inoue
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Yukari Omori
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Hiromi Ito
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Keiko Tamiya-Koizumi
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Akira Takagi
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Tetsuhito Kojima
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673
| | - Mitsuhiro Nakamura
- Department of Drug Information, Gifu Pharmaceutical University, Gifu 501-1196
| | - Soichiro Iwaki
- Department of Molecular and Cellular Pathophysiology and Therapeutics, Graduate School of Pharmaceutical Science, Nagoya City University, Nagoya 467-8603
| | - Masahiro Nakatochi
- Bioinformatics Section, Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya 466-8550
| | - Motoshi Suzuki
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya 466-8560; and
| | - Yoshinori Nozawa
- Department of Food and Health Science, Tokai Gakuin University, Kakamigahara 504-8511, Japan
| | - Takashi Murate
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673;
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Nishida Y, Mizutani N, Inoue M, Omori Y, Tamiya-Koizumi K, Takagi A, Kojima T, Suzuki M, Nozawa Y, Minami Y, Ohnishi K, Naoe T, Murate T. Phosphorylated Sp1 is the regulator of DNA-PKcs and DNA ligase IV transcription of daunorubicin-resistant leukemia cell lines. Biochim Biophys Acta 2014; 1839:265-74. [PMID: 24530422 DOI: 10.1016/j.bbagrm.2014.02.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2013] [Revised: 02/01/2014] [Accepted: 02/06/2014] [Indexed: 01/29/2023]
Abstract
Multidrug resistance (MDR) is a serious problem faced in the treatment of malignant tumors. In this study, we characterized the expression of non-homologous DNA end joining (NHEJ) components, a major DNA double strand break (DSB) repair mechanism in mammals, in K562 cell and its daunorubicin (DNR)-resistant subclone (K562/DNR). K562/DNR overexpressed major enzymes of NHEJ, DNA-PKcs and DNA ligase IV, and K562/DNR repaired DSB more rapidly than K562 after DNA damage by neocarzinostatin (MDR1-independent radiation-mimetic). Overexpressed DNA-PKcs and DNA ligase IV were also observed in DNR-resistant HL60 (HL60/DNR) cells as compared with parental HL60 cells. Expression level of DNA-PKcs mRNA paralleled its protein level, and the promoter activity of DNA-PKcs of K562/DNR was higher than that of K562, and the 5'-region between -49bp and the first exon was important for its activity. Because this region is GC-rich, we tried to suppress Sp1 family transcription factor using mithramycin A (MMA), a specific Sp1 family inhibitor, and siRNAs for Sp1 and Sp3. Both MMA and siRNAs suppressed DNA-PKcs expression. Higher serine-phosphorylated Sp1 but not total Sp1 of both K562/DNR and HL60/DNR was observed compared with their parental K562 and HL60 cells. DNA ligase IV expression of K562/DNR was also suppressed significantly with Sp1 family protein inhibition. EMSA and ChIP assay confirmed higher binding of Sp1 and Sp3 with DNA-PKcs 5'-promoter region of DNA-PKcs of K562/DNR than that of K562. Thus, the Sp1 family transcription factor affects important NHEJ component expressions in anti-cancer drug-resistant malignant cells, leading to the more aggressive MDR phenotype.
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Affiliation(s)
- Yayoi Nishida
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Naoki Mizutani
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Minami Inoue
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yukari Omori
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Keiko Tamiya-Koizumi
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akira Takagi
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tetsuhito Kojima
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Motoshi Suzuki
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | | | - Yosuke Minami
- Division of Blood Transfusion/Division of Oncology and Hematology, Kobe University Hospital, Kobe, Japan
| | - Kazunori Ohnishi
- Oncology Center, Hamamatsu University Graduate School of Medicine, Hamamatsu, Japan
| | - Tomoki Naoe
- National Hospital Organization, Nagoya Medical Center, Nagoya, Japan
| | - Takashi Murate
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya, Japan.
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11
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Tanaka K, Tamiya-Koizumi K, Yamada M, Murate T, Kannagi R, Kyogashima M. Individual profiles of free ceramide species and the constituent ceramide species of sphingomyelin and neutral glycosphingolipid and their alteration according to the sequential changes of environmental oxygen content in human colorectal cancer Caco-2 cells. Glycoconj J 2013; 31:209-19. [PMID: 24310545 DOI: 10.1007/s10719-013-9511-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/01/2013] [Accepted: 11/03/2013] [Indexed: 12/27/2022]
Abstract
We previously performed a systematic analysis of free ceramide (Cers) species, the constituent ceramide species of sphingomyelins and neutral glycosphingolipids (NGSLs) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with high-energy collision-induced dissociation. As a result, distinct species differences were found among Cers, sphingomyelins and NGSLs in the kidneys. Using this method, we investigated various sphingolipid species from human colon cancer Caco-2 cells as well as the influence of environmental oxygen on these species in detail. Unexpectedly, even in normoxia, all Cers species were composed of dihydrosphingosine (d18:0) and non-hydroxy fatty acid (NFA), and 34% of sphingomyelins were composed of dihydrosphingomyelins with NFA. In contrast, major constituent ceramide species of NGSLs were composed of the usual long-chain base of sphingosine (d18:1) and hydroxy fatty acid (HFA). When the cells were cultured under hypoxic condition for 3 days, all the Cers and nearly 80% of the sphingomyelins were dihydrosphingolipids composed of d18:0-NFAs, but a significant proportion of d18:1-HFAs still remained in the NGSLs. When the cells were transferred from conditions of hypoxia to normoxia again (reoxygenation), Cer species composed of d18:1-NFAs, which were not found in Cers under the original normoxic conditions, appeared. Such Cers were probably synthesized as precursors for the constituent ceramides of sphingomyelins and NGSLs.
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Affiliation(s)
- Kouji Tanaka
- Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Daiko-Minami 1-1-20, Higashi-ku, Nagoya, 461-8673, Japan
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Mizutani N, Kobayashi M, Sobue S, Ichihara M, Ito H, Tanaka K, Iwaki S, Fujii S, Ito Y, Tamiya-Koizumi K, Takagi A, Kojima T, Naoe T, Suzuki M, Nakamura M, Banno Y, Nozawa Y, Murate T. Sphingosine kinase 1 expression is downregulated during differentiation of Friend cells due to decreased c-MYB. Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 2013; 1833:1006-16. [DOI: 10.1016/j.bbamcr.2013.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Revised: 12/23/2012] [Accepted: 01/02/2013] [Indexed: 12/19/2022]
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Ito H, Tanaka K, Hagiwara K, Kobayashi M, Hoshikawa A, Mizutani N, Takagi A, Kojima T, Sobue S, Ichihara M, Suzuki M, Tamiya-Koizumi K, Nakamura M, Banno Y, Nozawa Y, Murate T. Transcriptional regulation of neutral sphingomyelinase 2 in all-trans retinoic acid-treated human breast cancer cell line, MCF-7. J Biochem 2012; 151:599-610. [PMID: 22496486 DOI: 10.1093/jb/mvs037] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Effects of all-trans retinoic acid (ATRA) on sphingomyelinase expression were examined using MCF-7 (ATRA-sensitive) and MDA-MB-231 (ATRA-resistant) breast cancer cells. Increased NSMase activity, NSMase2 mRNA and protein were observed in ATRA-treated MCF-7 but not in ATRA-treated MDA-MB-231. Increased NSMase2 mRNA of ATRA-treated MCF-7 was mostly due to enhanced transcription. Promoter analysis revealed the important 5'-promoter region of NSMase2 between -148 and -42 bp containing three Sp1 sites but no retinoic acid responsive elements. Experiments using mutated Sp1 sites of the NSMase2 promoter, Mithramycin A (a Sp inhibitor) and Sp family over-expression demonstrated the importance of Sp family protein and the three Sp1 sites for ATRA-induced NSMase2 transcription of MCF-7 cells. Although no quantitative change of bound Sp1 on NSMase2 promoter region after ATRA treatment was detected, Sp1 phosphorylation (activation) by ATRA was observed. Interestingly, PKCδ was involved in ATRA-induced increased NSMase2 transcription. ATRA-induced PKCδ phosphorylation and then activated PKCδ phosphorylated Sp1. Chromatin immunoprecipitation (ChIP) assay showed Sp1, RARα and RXRα complex formation in MCF-7 cells regardless of ATRA treatment and ATRA-induced acetylated histone H3 of the 5'-promoter. Thus, NSMase2 mRNA expression enhanced by ATRA was due to increased transcription via phosphorylated Sp1 caused by PKCδ activation, followed by chromatin remodelling with histone H3 acetylation.
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Affiliation(s)
- Hiromi Ito
- Department of Medical Technology, Nagoya University School of Health Sciences, Nagoya, Japan
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Tanaka K, Tamiya-Koizumi K, Hagiwara K, Ito H, Takagi A, Kojima T, Suzuki M, Iwaki S, Fujii S, Nakamura M, Banno Y, Kannagi R, Tsurumi T, Kyogashima M, Murate T. Role of down-regulated neutral ceramidase during all-trans retinoic acid-induced neuronal differentiation in SH-SY5Y neuroblastoma cells. ACTA ACUST UNITED AC 2012; 151:611-20. [DOI: 10.1093/jb/mvs033] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Murakami M, Ito H, Hagiwara K, Kobayashi M, Hoshikawa A, Takagi A, Kojima T, Tamiya-Koizumi K, Sobue S, Ichihara M, Suzuki M, Banno Y, Nozawa Y, Murate T. Sphingosine kinase 1/S1P pathway involvement in the GDNF-induced GAP43 transcription. J Cell Biochem 2012; 112:3449-58. [PMID: 21769916 DOI: 10.1002/jcb.23275] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is important for the development and maintenance of dopamine neurons (Lin et al. [1993] Science 260: 1130-1132). GDNF is neuroprotective in animal models of Parkinson disease, where dopamine neurons show selective degeneration. We previously reported GDNF-induced SPHK1 gene expression in a neuroblastoma cell line, TGW (Murakami et al. [2007] J Neurochem 102: 1585-1594). In the present study, we focused on the regulatory mechanism of GAP43 (GDNF-induced neuronal phenotype) transcription to further elucidate physiological roles of GDNF-induced SPHK1 expression and activity. Stable wild-type (SPHK1-WT) but not dominant-negative SPHK1 (SPHK1-DN) overexpression increased both control- and GDNF-induced GAP43 expression. SPHK1-WT cells showed enhanced GDNF-induced sphingosine 1-phosphate (S1P) secretion compared with mock- and SPHK1-DN cells. Exogenous S1P also increased GAP43 expression. In TGW cells, PD98059, a MEK inhibitor, but not SB203580 (a p38 MAPK inhibitor) and LY294002 (a PI3K inhibitor) inhibited GDNF-induced GAP43 expression, suggesting the MEK/ERK pathway has a major role in GDNF-induced GAP43 transcription. A G-protein-coupled receptor inhibitor, pertussis toxin, and S1P(1) and S1P(3) receptor antagonists (VPC23019 and CAY10444) also inhibited ERK activation. Moreover, both S1P1 and S1P3 were serine-phosphorylated by GDNF, suggesting their activated states. C/EBPβ transcription factor was induced by GDNF, and DNA pull-down and chromatin immunoprecipitation assays revealed the C/EBP binding site between -131 bp and -98 bp from the first exon of GAP43. Taken together, our results showed that in TGW cells, GDNF increased SPHK1 transcription, leading to the production and secretion of S1P. Through MEK/ERK pathway, S1P stimulates GAP43 transcription with increased binding of C/EBPβ to the 5'-promoter.
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Affiliation(s)
- Masashi Murakami
- Department of Oral Disease Research, National Center for Geriatrics and Gerontology, Obu, Japan
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Cao K, Tanaka K, Komizu Y, Tamiya-Koizumi K, Murate T, Ueoka R, Kyogashima M, Usukura J, Takahashi T, Suzuki M. Hybrid liposomes affect cellular lipid constituents and caveolae structures. Bioorg Med Chem Lett 2011; 22:1731-3. [PMID: 22248855 DOI: 10.1016/j.bmcl.2011.12.093] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [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: 10/25/2011] [Revised: 12/05/2011] [Accepted: 12/20/2011] [Indexed: 01/15/2023]
Abstract
We examined alterations of lipid constituents induced by hybrid liposomes (HLs) in cancer cells. As early as 1h after HL treatment, amounts of the raft/caveolae lipids sphingomyelin, ceramide, and ether-type PC were altered. In addition, the structures of caveolae on the cytoplasmic surface of the cell membrane were significantly changed. Our results suggest that alterations of lipid composition in caveolae mediate HL signaling for apoptosis.
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Affiliation(s)
- Ke Cao
- Division of Molecular Carcinogenesis, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Tanaka K, Yamada M, Tamiya-Koizumi K, Kannagi R, Aoyama T, Hara A, Kyogashima M. Systematic analyses of free ceramide species and ceramide species comprising neutral glycosphingolipids by MALDI-TOF MS with high-energy CID. Glycoconj J 2011; 28:67-87. [DOI: 10.1007/s10719-011-9325-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 01/11/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
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Ito H, Yoshida K, Murakami M, Hagiwara K, Sasaki N, Kobayashi M, Takagi A, Kojima T, Sobue S, Suzuki M, Tamiya-Koizumi K, Nakamura M, Banno Y, Nozawa Y, Murate T. Heterogeneous sphingosine-1-phosphate lyase gene expression and its regulatory mechanism in human lung cancer cell lines. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1811:119-28. [PMID: 21184844 DOI: 10.1016/j.bbalip.2010.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [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: 06/26/2010] [Revised: 12/11/2010] [Accepted: 12/15/2010] [Indexed: 11/19/2022]
Abstract
The role of sphingolipid metabolic pathway has been recognized in determining cellular fate. Although sphingolipid degradation has been extensively studied, gene expression of human sphingosine 1-phosphate lyase (SPL) catalyzing sphingosine 1-phosphate (S1P) remains to be determined. Among 5 human lung cancer cell lines examined, SPL protein levels paralleled the respective mRNA and enzyme activities. Between H1155 and H1299 cells used for further experiments, higher cellular S1P was observed in H1155 with higher SPL activity compared with H1299 with low SPL activity. GATA-4 has been reported to affect SPL transcription in Dictyostelium discoideum. GATA-4 was observed in H1155 but not in other cell lines. Overexpression of GATA-4 in H1299 increased SPL expression. However, promoter analysis of human SPL revealed that the most important region was located between -136bp and -88bp from the first exon, where 2 Sp1 sites exist but no GATA site. DNA pull-down assay of H1155 showed increased DNA binding of Sp1 and GATA-4 within this promoter region compared with H1299. Electrophoresis mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP) assay, reporter assay using mutated binding motif, and mithramycin A, a specific Sp1 inhibitor, suggest the major role of Sp1 in SPL transcription and no direct binding of GATA-4 with this 5' promoter region. The collaborative role of GATA-4 was proved by showing coimmunoprecipitation of Sp1 and GATA-4 using GST-Sp1 and overexpressed GATA-4. Thus, high SPL transcription of H1155 cells was regulated by Sp1 and GATA-4/Sp1 complex formation, both of which bind to Sp1 sites of the 5'-SPL promoter.
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Affiliation(s)
- Hiromi Ito
- Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Nagoya, Japan
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Murate T, Yoshida K, Ito H, Murakami M, Hagiwara K, Sasaki N, Takagi A, Kojima T, Sobue S, Suzuki M, Tamiya-Koizumi K, Nakamura M, Banno Y, Nozawa Y. Heterogeneous sphingosine-1-phosphate lyase gene expression and its regulatory mechanism in human lung cancer cell lines. Chem Phys Lipids 2010. [DOI: 10.1016/j.chemphyslip.2010.05.159] [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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Ito H, Murakami M, Hagiwara K, Sasaki N, Kobayashi M, Hoshikawa A, Takagi A, Kojima T, Banno Y, Tamiya-Koizumi K, Nakamura M, Nozawa Y, Murate T. The regulatory mechanism of NSMase2 gene expression by ATRA in MCF7 cells. Chem Phys Lipids 2010. [DOI: 10.1016/j.chemphyslip.2010.05.155] [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]
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Murakami M, Ito H, Hagiwara K, Yoshida K, Sobue S, Ichihara M, Takagi A, Kojima T, Tanaka K, Tamiya-Koizumi K, Kyogashima M, Suzuki M, Banno Y, Nozawa Y, Murate T. ATRA inhibits ceramide kinase transcription in a human neuroblastoma cell line, SH-SY5Y cells: the role of COUP-TFI. J Neurochem 2009; 112:511-20. [PMID: 19903244 DOI: 10.1111/j.1471-4159.2009.06486.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Ceramide is the central lipid in the sphingolipid metabolism. Ceramide kinase (CERK) and its product, ceramide 1-phosphate, have been implicated in various cellular functions. However, the regulatory mechanism of CERK gene expression remains to be determined. Here, we examined CERK mRNA level during all-trans retinoic acid (ATRA)-induced differentiation of a human neuroblastoma cell line, SH-SY5Y. ATRA reduced CERK mRNA and protein levels. Over-expression and small interfering RNA (siRNA) of CERK revealed that CERK is inhibitory against ATRA-induced neuronal differentiation and cell growth arrest. ATRA inhibited the transcriptional activity of 5'-promoter of CERK. Truncation and mutation study suggests that ATRA-responsible region was mainly located in the tandem retinoic acid responsive elements (RARE) between -40 bp and the first exon. The electrophoresis mobility shift assay revealed that ATRA produced two retarded bands, which were erased by antibody against chicken ovalbumin upstream promoter transcription factor I (COUP-TFI), RARalpha, and RXRalpha, respectively. DNA pull-down assay confirmed increased binding of these transcription factors to RARE. Transient expression of RAR, RXR, and COUP-TFI and siRNA transfection of these genes revealed that COUP-TFI inhibited CERK mRNA. Furthermore, chromatin immunoprecipitation assay showed the recruitment of co-repressors as well as three transcription factors. These results suggest that COUP-TFI was the ATRA-responsive suppressive transcription factor of CERK gene transcription.
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Affiliation(s)
- Masashi Murakami
- Research Fellow of the Japanese Society for the Promotion of Sciences, Nagoya, Japan
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Ito H, Murakami M, Furuhata A, Gao S, Yoshida K, Sobue S, Hagiwara K, Takagi A, Kojima T, Suzuki M, Banno Y, Tanaka K, Tamiya-Koizumi K, Kyogashima M, Nozawa Y, Murate T. Transcriptional regulation of neutral sphingomyelinase 2 gene expression of a human breast cancer cell line, MCF-7, induced by the anti-cancer drug, daunorubicin. Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms 2009; 1789:681-90. [DOI: 10.1016/j.bbagrm.2009.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2009] [Revised: 08/08/2009] [Accepted: 08/10/2009] [Indexed: 11/29/2022]
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Ito H, Murakami M, Hagiwara K, Yoshida K, Tagawa Y, Sasaki N, Takagi A, Kojima T, Banno Y, Tamiya-Koizumi K, Nozawa Y, Murate T. Daunorubicin-induced neutral sphingomyelinase 2 gene expression in MCF7 cells. Chem Phys Lipids 2009. [DOI: 10.1016/j.chemphyslip.2009.06.045] [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: 10/20/2022]
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Kyogashima M, Tadano-Aritomi K, Aoyama T, Yusa A, Goto Y, Tamiya-Koizumi K, Ito H, Murate T, Kannagi R, Hara A. Chemical and Apoptotic Properties of Hydroxy-Ceramides Containing Long-Chain Bases with Unusual Alkyl Chain Lengths. ACTA ACUST UNITED AC 2008; 144:95-106. [DOI: 10.1093/jb/mvn050] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Akutagawa A, Fukami K, Banno Y, Takenawa T, Kannagi R, Yokoyama Y, Oda K, Nagino M, Nimura Y, Yoshida S, Tamiya-Koizumi K. Disruption of Phospholipase Cδ4 Gene Modulates the Liver Regeneration in Cooperation with Nuclear Protein Kinase C. ACTA ACUST UNITED AC 2006; 140:619-25. [PMID: 16998201 DOI: 10.1093/jb/mvj194] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Phospholipase Cdelta4 (PLC delta4) gene has been cloned from the cDNA library of regenerating rat liver. Using PLC delta4 gene-disrupted mice (PLC delta4(-/-)), we studied a role of PLC delta4 during liver regeneration after partial hepatectomy (PH). In PLC delta4(-/-), liver regeneration occurred in an apparently normal way. However, BrdU-indices indicated that PLC delta4 gene disruption delayed the onset of DNA synthesis by 2 h. Noticeably, the BrdU-indices in PLC delta4(+/+) remained rather constant throughout S phase, 25-35%, whereas in PLC delta4(-/-), it fluctuated drastically from 25% at 34 h to 65% at late S, 42 h after PH. This fact showed that PLC delta4 gene disruption caused a higher synchronization of cell proliferation. The mRNA for PLC delta4 in PLC delta4(+/+) appeared at late G1, and the expression continued throughout S phase. PLC activity increased transiently in chromatin at the late G1 and S phases in only PLC delta4(+/+), but not in PLC delta4(-/-). The specific increases in PLC activity well correlated with the transient increases of protein kinase C (PKC) alpha in chromatin of PLC delta4(+/+). PKC epsilon also increased transiently in chromatin from PLC delta4(+/+) at late S. It is concluded that PLC delta4 regulates the liver regeneration in cooperation with nuclear PKC alpha and epsilon.
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Affiliation(s)
- Atsushi Akutagawa
- Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, 65, Tsurumai-cho, Showa-ku, Nagoya 466-8550
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Kyogashima M, Tamiya-Koizumi K, Ehara T, Li G, Hu R, Hara A, Aoyama T, Kannagi R. Rapid demonstration of diversity of sulfatide molecular species from biological materials by MALDI-TOF MS. Glycobiology 2006; 16:719-28. [PMID: 16670104 DOI: 10.1093/glycob/cwj122] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [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: 01/08/2023] Open
Abstract
By combining the partition method for enrichment of sulfatides without any chromatographic procedures and the preparation method of lysosulfatides, we succeeded in analyzing these sulfated glycosphingolipids from biological materials by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) to reduce the complexity of mass fragmentation patterns within a day. We found that sulfated GalCer (HSO3-3Gal beta 1Cer) (SM4s [galactosylsulfatide]) was composed of different species. While composition of SM4s specifically depended on source materials, it always contained hydroxy fatty acids of various degrees. In addition to the common sphingoid 4-sphingenine (d18:1), uncommon/unusual sphingoids phytosphingosine (4-hydroxysphinganine) (t18:0), eicosasphinganine (d20:0), 4-eicosasphingenine (d20:1), and sphingadienine (d18:2) were easily detected. Finally, in addition to SM4s, sulfatide sulfated LacCer (HSO3-3Gal beta 4Glc beta 1Cer) (SM3 [sulfated lactosylceramide]) and sulfated Gg3Cer (GalNAc beta 4(HSO3-3)Gal beta 4Glc beta 1Cer) (SM2 [sulfated gangliotriaosylceramide]) were clearly detected in renal tubule cells. The major SM4s was composed of ceramides possessing d18:1 with C22 hydroxy fatty acids (C22:0 h), C23:0 h, and C24:0 h, whereas the major SM3/SM2 were composed of ceramides possessing t18:0 with C22 normal fatty acids (C22:0), C23:0, C24:0. Namely, in these two series of sulfatides, either fatty acids or sphingoids were hydroxylated, and chain lengths of these components were exactly the same, consequently resulting in a similar polarity of ceramide moieties in these sulfatide species. These results demonstrated diversities of sulfatide molecular species, not only with respect to sugar moieties but also to ceramide moieties, which are probably important for specific effective functions in particular microenvironments such as lipid membrane microdomains.
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Affiliation(s)
- Mamoru Kyogashima
- Department of Metabolic Regulation, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine, 3-1-1, Asahi, Matsumoto, Nagano, 390-8621, Japan.
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Nakamura N, Banno Y, Tamiya-Koizumi K. Arf1-dependent PLD1 is localized to oleic acid-induced lipid droplets in NIH3T3 cells. Biochem Biophys Res Commun 2005; 335:117-23. [PMID: 16054594 DOI: 10.1016/j.bbrc.2005.07.050] [Citation(s) in RCA: 34] [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] [Received: 06/22/2005] [Accepted: 07/13/2005] [Indexed: 11/20/2022]
Abstract
Phospholipase D (PLD) is known to play a role in vesicle transport through the hydrolysis of phosphatidylcholine (PC) to produce the bioactive lipid, phosphatidic acid. Lipid droplets (LDs) are surrounded by a monolayer of phospholipids, including PC and its lyso derivative, and exhibit a number of signaling proteins. Our recent report suggests that the association of adipose differentiation-related protein (ADRP) to LDs is regulated by an ADP-ribosylation factor 1 (Arf1)-dependent mechanism. In the present study, we found an increase in PLD activity accompanied with LD formation in oleic acid-treated NIH3T3 cells. Brefeldin A, an inhibitor of ARF-GEFs, suppressed both PLD activation and LD formation in oleic acid-treated cells. PLD1, but not PLD2, was found to exist in LDs by immunocytochemical analysis. Furthermore, co-existence of PLD1, Arf1, and ADRP was observed in the LD-enriched subcellular fractions obtained from oleic acid-treated NIH3T3 cells by Western blot analysis. PLD1 activity in the LD-enriched fractions was stimulated by exogenously added Arf1. Although LDs were induced in either PLD1- or PLD2-overexpressing CHO cells by oleic acid treatment, the stimulation of PLD activity was observed only in PLD1-CHO cells. Taken together, the data suggest that the activation of Arf1-dependent PLD1 occurs in LDs and may be involved in their physiological function.
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Affiliation(s)
- Noriko Nakamura
- Department of Anatomy and Molecular Cell Biology, Nagoya University, Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
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Sobue S, Hagiwara K, Banno Y, Tamiya-Koizumi K, Suzuki M, Takagi A, Kojima T, Asano H, Nozawa Y, Murate T. Transcription factor specificity protein 1 (Sp1) is the main regulator of nerve growth factor-induced sphingosine kinase 1 gene expression of the rat pheochromocytoma cell line, PC12. J Neurochem 2005; 95:940-9. [PMID: 16135093 DOI: 10.1111/j.1471-4159.2005.03399.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [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: 11/30/2022]
Abstract
Sphingosine kinase (SPHK) is known to exert an anti-apoptic role in various cells and cell lines. We previously reported that human brain is rich in SPHK1 (Murate et al. 2001). After showing a high expression of SPHK1 in rat brain, we examined the gene expression mechanism using nerve growth factor (NGF)-stimulated rat PC12 cells. With RT-PCR, we found that both rat brain and PC12 utilized exon 1d mostly out of eight untranslated first exons. NGF induced an increase in SPHK enzyme activity and protein about double those in PC12 cells, and NGF-induced SPHK1 mRNA was three times higher than in the control. The minimal 5' promoter was determined, and TrkA specific inhibitor K252a inhibited the NGF-induced promoter activity of SPHK1. The truncation or mutation of putative transcription factor-binding motifs revealed that one specificity protein 1 (Sp1) binding motif of the 5' region of exon 1d is prerequisite. Electrophoresis mobility shift assay confirmed the promoter analysis, indicating increased Sp1 protein binding to this motif after NGF treatment. Chromatin immunoprecipitation assay also showed the binding of Sp1 and the promoter region in vivo. These results suggest the signal transduction pathway from NGF receptor TrkA to transcription factor Sp1 protein binding to the promoter Sp1-like motif in NGF-induced rat SPHK1 gene expression.
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Affiliation(s)
- S Sobue
- Nagoya University Graduate School of Medicine, Nagoya University School of Health Sciences, Daiko-minami, Nagoya, Japan
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Koda M, Murate T, Wang S, Ohguchi K, Sobue S, Ikeda M, Tamiya-Koizumi K, Igarashi Y, Nozawa Y, Banno Y. Sphingosine kinase 1 is involved in dibutyryl cyclic AMP-induced granulocytic differentiation through the upregulation of extracellular signal-regulated kinase, but not p38 MAP kinase, in HL60 cells. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1733:101-10. [PMID: 15863357 DOI: 10.1016/j.bbalip.2004.12.006] [Citation(s) in RCA: 10] [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] [Received: 03/23/2004] [Revised: 10/19/2004] [Accepted: 12/16/2004] [Indexed: 01/31/2023]
Abstract
The role of sphingosine kinase (SPHK) in the dibutyryl cyclic AMP (dbcAMP)-induced granulocytic differentiation of HL60 cells was investigated. During differentiation, SPHK activity was increased, as were mRNA and protein levels of SPHK1, but not of SPHK2. Pretreatment of HL60 cells with N,N-dimethylsphingosine (DMS), a potent SPHK inhibitor, completely blocked dbcAMP-induced differentiation. The phosphorylation of mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 MAPK was also increased during dbcAMP-induced differentiation. Pretreatment of HL60 cells with the MEK inhibitor, U0126, but not the p38 MAPK inhibitor, SB203580, completely suppressed dbcAMP-induced ERK1/2 activation and granulocytic differentiation, but did not affect the increase in SPHK activity. DMS inhibited dbcAMP-induced ERK1/2 activation, but had little effect on p38 MAPK activation. DMS had no effect on the dbcAMP-induced membrane translocation of protein kinase C (PKC) isozymes, and PKC inhibitors had no significant effect on ERK activation. The overexpression of wild-type SPHK1, but not dominant negative SPHK1, resulted in high basal levels of ERK1/2 phosphorylation and stimulated granulocytic differentiation in HL60 cells. These data show that SPHK1 participates in the dbcAMP-induced differentiation of HL60 cells by activating the MEK/ERK pathway.
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Affiliation(s)
- Masahiro Koda
- Department of Cell Signaling, Gifu University Graduate School of Medicine, Japan
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30
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Abstract
Evidence has been accumulating that nuclear lipid metabolism is involved in the regulation of nuclear functions. Here I describe an autonomous nuclear lipid signaling that has been found to be associated with the metabolism of such lipids as phosphoinositides, choline phospholipids, and the acylation and deacylation cycle. Some lipid signals from the plasma membrane ultimately reach the nucleus and regulate the nuclear function. In this case, however, generated lipids and their metabolites may not directly act on the nuclear factors involved in nuclear function. The unique and direct effects of nuclear lipids and their metabolites on nuclear factors are also discussed.
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Affiliation(s)
- Keiko Tamiya-Koizumi
- Laboratory of Cancer Cell Biology, Research Institute for Disease Mechanism and Control, Nagoya University Graduate School and Faculty of Medicine, Nagoya 464-8550, Japan.
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31
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Akao Y, Kusakabe S, Banno Y, Kito M, Nakagawa Y, Tamiya-Koizumi K, Hattori M, Sawada M, Hirabayasi Y, Ohishi N, Nozawa Y. Ceramide accumulation is independent of camptothecin-induced apoptosis in prostate cancer LNCaP cells. Biochem Biophys Res Commun 2002; 294:363-70. [PMID: 12051721 DOI: 10.1016/s0006-291x(02)00462-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 11/24/2022]
Abstract
We have investigated to determine the source of ceramide produced during the genotoxic apoptosis induced by the anti-cancer drug, camptothecin (CPT), in human prostate cancer LNCaP cells by measuring the activities of acid and neutral sphingomyelinases (SMase) and by using fumonisinB(1) (FB(1)), the inhibitor of ceramide synthase involving de novo synthesis of ceramide. In contrast to time-dependent elevation of intracellular ceramide level after CPT-treatment, the activities of both SMases were not increased but rather decreased. Instead, pretreatment for 3 h with FB(1) (100 microM), an inhibitor of ceramide synthase, almost completely abrogated ceramide accumulation observed in cells exposed to CPT for 18 h. These results indicate that ceramide is produced via de novo pathway but not via sphingomyelin hydrolysis pathway. Furthermore, it is to be noted that the pretreatment with FB(1) did not affect the CPT-induced apoptosis as assessed by DNA ladder formation, Hoechst 33342 staining, flow cytometry, and mitochondrial potential thereby leading us to propose that ceramide accumulation is independent of apoptosis in this system.
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Affiliation(s)
- Yukihiro Akao
- Gifu International Institute of Biotechnology, Mitake-cho 2193-128, Kani-gun, Gifu 505-0116, Japan
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32
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Murate T, Suzuki M, Hattori M, Takagi A, Kojima T, Tanizawa T, Asano H, Hotta T, Saito H, Yoshida S, Tamiya-Koizumi K. Up-regulation of acid sphingomyelinase during retinoic acid-induced myeloid differentiation of NB4, a human acute promyelocytic leukemia cell line. J Biol Chem 2002; 277:9936-43. [PMID: 11788605 DOI: 10.1074/jbc.m111594200] [Citation(s) in RCA: 40] [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: 11/06/2022] Open
Abstract
All-trans-retinoic acid (ATRA) induces myeloid differentiation of a human promyelocytic leukemia cell line, NB4, but does not affect its subclone NB4/RA harboring a point-mutated ligand-binding domain (AF2) in retinoic acid receptor alpha (RARalpha) gene. We found that ATRA induced the 4-fold elevation of acid sphingomyelinase (ASMase) activity 24 h after treatment in NB4 cells, but not in NB4/RA cells. ATRA did not affect neutral sphingomyelinase activity in either NB4 or NB4/RA. Upon treatment with ATRA, ceramide, the product of an ASMase reaction, accumulated in NB4 cells. Northern blot analysis showed a marked elevation of the ASMase mRNA 8 h after ATRA treatment, reaching a plateau at 24 h. Regulation of ASMase gene expression was studied by a promoter analysis using luciferase reporter assay. The 5'-upstream flanking region of human ASMase gene (-519/+300) conjugated with the luciferase gene was introduced into COS-7 cells. Luciferase activity in transformed cells markedly increased in response to ATRA stimulation when the wild type RARalpha or the PML/RARalpha hybrid protein was co-expressed. Deletion experiments revealed that a short sequence at the 5'-end (-519/-485) was indispensable for the ATRA response. Within this short region, two retinoic acid-responsive element-like motifs (TGCCCG and TCTCCT) and one AP2-like motif (CCCTTCCC) were identified. Deletion and base-substitution experiments showed that all three motifs are required for the full expression induced by ATRA. Electrophoresis mobility shift assays with the nuclear extract of ATRA-treated NB4 cells showed that proteins were bound specifically to the probe being mediated by all three motifs in the promoter sequence.
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MESH Headings
- Amino Acid Motifs
- Animals
- Base Sequence
- Blotting, Northern
- COS Cells
- Cell Differentiation
- Cell Nucleus/metabolism
- Ceramides/pharmacology
- Dose-Response Relationship, Drug
- Gene Deletion
- Genes, Reporter
- Humans
- Leukemia, Promyelocytic, Acute/enzymology
- Luciferases/metabolism
- Molecular Sequence Data
- Mutation
- Plasmids/metabolism
- Protein Binding
- Protein Structure, Tertiary
- Receptors, Retinoic Acid/genetics
- Retinoic Acid Receptor alpha
- Reverse Transcriptase Polymerase Chain Reaction
- Spectrometry, Mass, Electrospray Ionization
- Sphingomyelin Phosphodiesterase/biosynthesis
- Sphingomyelin Phosphodiesterase/genetics
- Sphingomyelin Phosphodiesterase/metabolism
- Time Factors
- Transfection
- Tretinoin/metabolism
- Tumor Cells, Cultured
- Up-Regulation
- beta-Galactosidase/metabolism
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Affiliation(s)
- Takashi Murate
- Nagoya University School of Health Science, Nagoya 466-8550, Japan.
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33
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Tamiya-Koizumi K. [Localization of sphingomyelinase to Triton X-100-insoluble microdomain and its functional importance]. Tanpakushitsu Kakusan Koso 2002; 47:463-9. [PMID: 11915343] [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] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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34
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Mizutani Y, Tamiya-Koizumi K, Nakamura N, Kobayashi M, Hirabayashi Y, Yoshida S. Nuclear localization of neutral sphingomyelinase 1: biochemical and immunocytochemical analyses. J Cell Sci 2001; 114:3727-36. [PMID: 11707524 DOI: 10.1242/jcs.114.20.3727] [Citation(s) in RCA: 38] [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
To examine the intracellular localization of neutral sphingomyelinase 1 (nSMase 1), a rabbit polyclonal antibody was raised against a recombinant form of the enzyme expressed in E. coli. It has been reported that, in rat liver or in ascites hepatoma AH7974, high activity of neutral sphingomyelinase (SMase) is found at the plasma membrane, with a lesser but significant amount in nucleus and cytoplasm. The biochemical properties, dithiothreitol requirement and high salt concentration dependency, of cloned and expressed nSMase 1 resemble those of previously described nuclear neutral SMase of AH7974. The present study was therefore focused on the nuclear localization of this enzyme. Western blotting of subcellular fractions using anti-rat nSMase 1 antibody revealed most nSMase 1 to be associated with the nuclei and some with microsomes, but not with plasma membranes. Consistently, neutral SMase activity in nuclear extract was immunoprecipitated by the antibody, while that of plasma membranes was not. The results indicate that nSMase 1 mainly resides in the nucleus and may thus differ from neutral SMase in plasma membrane. On gel-filtration column chromatography of nuclear extract, the profile of neutral SMase activity corresponded well with immunoreactive protein bands on western blotting, suggesting that a large part of nuclear neutral SMase may be nSMase 1. Removal of the nuclear envelope by treatment with Triton X-100 did not significantly decrease the amount of nuclear nSMase 1, and western blotting of subnuclear fractions (i.e. nuclear envelope, chromatin, and nuclear matrix) revealed nSMase 1 signal exclusively in the nuclear matrix. Immunocytochemistry with AH7974, as well as rat fibroblast cell line 3Y1, demonstrated nSMase 1 to be localized mainly in the nucleus, with some in the cytoplasm. Moreover, immuno-electron microscopy clearly showed the signal of nSMase 1 to be more dense in the nucleus than in the cytoplasm of AH7974.
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Affiliation(s)
- Y Mizutani
- Laboratory of Cancer Cell Biology, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Showa-ku, Nagoya, 466-8550, Japan
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35
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Ito Y, Tamiya-Koizumi K, Koide Y, Nakagawa M, Kawade T, Nishida A, Murate T, Takemura M, Suzuki M, Yoshida S. Structural requirements of sphingosine molecules for inhibition of DNA primase: biochemical and computational analyses. Biochemistry 2001; 40:11571-7. [PMID: 11560507 DOI: 10.1021/bi010722i] [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: 11/30/2022]
Abstract
Using 28 chemically well-defined compounds containing D-erythro-sphingosine and its analogues, we analyzed structure-activity relationships for DNA primase inhibition. Biochemical studies demonstrated a positively charged amino group at C2 and a long aliphatic chain to be absolutely required for inhibition. Whereas C2-amino group is intact, sphingosine 1-phosphate was totally inactive. This result could be due to cancellation of positive charge of the amino group by the interaction with negatively charged C1-phosphate, since simulations with the software INSIGHT II showed these two groups to be close enough to interact. The hydroxyl group at C3 and trans-double bond at C4-C5 were also found to be important for the inhibition. Dehydroxylation of C3, as well as saturation or cis-conversion of the trans-double bond led to decrease of inhibitory activity. Despite saturation of the double bond, introduction of a hydroxyl group into C4 of dihydrosphingosine resulted in restoration of inhibition. Conversion of the double bond into a triple bond did not abolish but rather enhanced the inhibitory activity. Among sphingosine stereoisomers, the naturally occurring D-erythro-sphingosine proved to be the strongest inhibitor. To ascertain the contribution of the total conformation to the inhibition, especially of the long aliphatic chain, we constructed a 3D-quantitative structure-activity relationship model using the computer program Catalyst/HipHop on the basis of information described above. Analysis of the hypothesis model for active compounds revealed that the orientation of aliphatic chain, represented by the dihedral angle of C2-3-4-5, correlated well with the inhibition. Modifications such as deletion of the hydroxyl group at C3 or saturation of the C4-C5 double bond caused shifts in the dihedral angle of C2-3-4-5, with concomitant decrease in inhibitory activity.
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Affiliation(s)
- Y Ito
- Equipment Center for Research and Education, Laboratory of Cancer Cell Biology, School of Health Science, Nagoya University School of Medicine, Showa-ku, Nagoya, Japan.
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36
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Mizutani Y, Tamiya-Koizumi K, Irie F, Hirabayashi Y, Miwa M, Yoshida S. Cloning and expression of rat neutral sphingomyelinase: enzymological characterization and identification of essential histidine residues. Biochim Biophys Acta 2000; 1485:236-46. [PMID: 10832103 DOI: 10.1016/s1388-1981(00)00059-7] [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: 10/17/2022]
Abstract
Using cross-species sequence homology, we cloned a cDNA for rat neutral sphingomyelinase (nSMase) composed of 422 amino acids that shares 87.6 and 79.0% identity with the mouse and human forms respectively. The rat nSMase expressed in Escherichia coli catalyzed sphingomyelin hydrolysis at neutral pH in a Mg(2+)-dependent manner, and required Triton X-100, dithiothreitol, and KCl for its full activity. The cloned rat enzyme shares conserved sequences with nSMases from both eukaryotes and prokaryotes. Introduction of single mutations into either of the histidine residues at positions 136 and 272, putative active sites, entirely abolished the activity, supporting a common mechanism for the nSMase family independent of the species. However, mutation in histidine 151, conserved only in eukaryotes, also abolished the activity, suggesting eukaryote-specific control of nSMase linked to this histidine 151. This enzyme also catalyzed the hydrolysis of lyso-platelet activating factor to yield 1-alkylglycerol at a rate that is slightly lower than that with sphingomyelin.
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Affiliation(s)
- Y Mizutani
- Laboratory of Cancer Cell Biology, Research Institute for Disease Mechanisms and Control, Nagoya University School of Medicine, Japan
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37
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Abstract
BACKGROUND/AIMS Portal vein branch ligation induces apoptosis of hepatocytes in the ligated lobes in rat liver. Sphingomyelin degradation was studied during the process to evaluate its possible involvement in apoptosis in vivo. METHODS DNA scissions were detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and an agarose gel electrophoresis of DNA. Using both ligated and non-ligated lobes, we measured activities of sphingomyelin degradation enzymes and contents of their products in purified nuclei and plasma membrane. RESULTS DNA fragmentation was detectable in the ligated lobes at 90 min after the portal vein branch ligation by gel electrophoresis. At 15 h after the ligation, 27% of hepatocytes became TUNEL-positive. Prior to the onset of apoptosis, the activity of neutral sphingomyelinase increased in the nuclei of hepatocytes in ligated lobes (30 min after the ligation). The increase in sphingomyelinase paralleled its reaction product, ceramide. This was followed by the elevation of ceramidase activity in nuclei (60 min after the ligation) in association with an increase of its reaction product, sphingosine. Activities of these two enzymes and their products increased for at least 90 min. These changes were not observed in nuclei of the non-ligated lobes, or in the plasma membranes from either ligated or non-ligated lobes. CONCLUSIONS These results, specific to the liver where apoptosis is being generated, suggest that nuclear sphingomyelin breakdown with an accumulation of ceramide and/or sphingosine in nuclei may induce the apoptosis of hepatocytes in vivo.
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Affiliation(s)
- K Tsugane
- First Department of Surgery, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Japan
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38
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Isogai C, Murate T, Tamiya-Koizumi K, Yoshida S, Ito T, Nagai H, Kinoshita T, Kagami Y, Hotta T, Hamaguchi M, Saito H. Analysis of bax protein in sphingosine-induced apoptosis in the human leukemic cell line TF1 and its bcl-2 transfectants. Exp Hematol 1998; 26:1118-25. [PMID: 9808050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Sphingosine, a sphingolipid breakdown product, has been proposed as an apoptosis-inducing agent. In this study, we examined the effect of sphingosine in bcl-2-overexpressing cells compared with cells that do not express the bcl-2 gene. The human erythroleukemic cell line TF1, which lacks bcl-2 expression, was easily induced to undergo apoptotic cell death by a variety of stimuli, including depletion of granulocyte-macrophage colony-stimulating factor (GM-CSF) or exposure to methylmethane sulfonate (MMS) (100 microg/mL), ultraviolet light (15 J/m2), X-ray irradiation (20 Gy), or sphingosine, a sphingolipid breakdown product (5 microM). In contrast, bcl-2 transfectants of TF1 (TF1-bcl2), which we established, were resistant to most of these treatments but remained sensitive to sphingosine. Neither C2- nor C6-ceramide (short-chain ceramide) induced apoptosis in TF1-mock and TF1-bcl2 cells. Sphingosine-induced apoptosis could not be inhibited by fumonisin B1, which can prevent conversion of sphingosine to ceramide, suggesting that sphingosine itself, not ceramide, possesses apoptosis-inducing capability. Western blotting, which revealed a 21-kDa bax protein in untreated cells, revealed the presence of an additional 18-kDa protein in GM-CSF-depleted and MMS- or sphingosine-treated TF1-mock cells. In TF1-bcl2 cells, this protein was not detected after GM-CSF depletion or MMS treatment, but was observed after sphingosine treatment. Immunoprecipitation with anti-bcl2 antibody, followed by immunoblotting with anti-bax antibody, showed that both the 21-kDa bax protein and the 18-kDa protein heterodimerized with bcl-2 protein. These results suggest that sphingosine is a unique reagent for apoptosis and that it can overcome bcl-2 gene expression. Furthermore, induction of 18-kDa bax-related protein may play an important role in apoptosis. Sphingosine, but not ceramide, may prove applicable as a reagent for future cytotoxic drugs used to treat intractable tumors overexpressing bcl-2.
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Affiliation(s)
- C Isogai
- First Department of Internal Medicine, Nagoya University School of Medicine, Japan
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39
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Tamiya-Koizumi K, Murate T, Suzuki M, Simbulan CM, Nakagawa M, Takemura M, Furuta K, Izuta S, Yoshida S. Inhibition of DNA primase by sphingosine and its analogues parallels with their growth suppression of cultured human leukemic cells. Biochem Mol Biol Int 1997; 41:1179-89. [PMID: 9161713 DOI: 10.1080/15216549700202271] [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] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sphingosine is a potent inhibitor of a mammalian DNA primase in vitro (Simbulan et al., Biochemistry 33, 9007-9012, 1994). Here we measured the inhibition of DNA primase in vitro by 9 sphingosine-analogues with respect to RNA primer synthesis and DNA primase-dependent DNA synthesis, and their potencies of inhibition in vitro were compared with their in vivo effects on human leukemic cells. Sphingosine, phytosphingosine and N, N-dimethylsphingosine strongly inhibited the activity of purified calf thymus DNA primase, and also inhibited the growth of human leukemic cell line HL-60, exerting strong cytotoxicity. Dihydrosphingosine and cis-sphingosine, which showed more subtle inhibition of DNA primase in vitro, moderately inhibited the cell growth in vivo and caused cell death. In contrast, N-acyl-, N-octyl-, and N-acetylsphingosine (ceramides) showing little inhibition of DNA primase suppressed cell growth only slightly. HL 60 cell was arrested at Go/G1 phase by exogenously added sphingosine. From these results, it is suggested that DNA primase is one of targets of sphingosine, an effector molecule in apoptosis.
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Affiliation(s)
- K Tamiya-Koizumi
- Laboratory of Cancer Cell Biology, Nagoya University School of Medicine, Japan
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40
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Banno Y, Tamiya-Koizumi K, Oshima H, Morikawa A, Yoshida S, Nozawa Y. Nuclear ADP-ribosylation factor (ARF)- and oleate-dependent phospholipase D (PLD) in rat liver cells. Increases of ARF-dependent PLD activity in regenerating liver cells. J Biol Chem 1997; 272:5208-13. [PMID: 9030590 DOI: 10.1074/jbc.272.8.5208] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Two forms of phospholipase D (PLD) have been found to be present in nuclei isolated from rat hepatocytes by measuring phosphatidylbutanol produced from exogenous radiolabeled phosphatidylcholine in the presence of butanol. In nuclear lysates from either rat liver or ascites hepatoma AH 7974 cells, the PLD activity was markedly stimulated by a recombinant ADP-ribosylation factor (rARF) in the presence of the guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) and phosphatidylinositol 4, 5-bisphosphate. ATP and phorbol-12-myristate 13-acetate had no synergistic effect on this PLD activity. On the other hand, the nuclear PLD was stimulated by unsaturated fatty acids, especially by oleic acid. The ARF-dependent nuclear PLD activity was increased in the S-phase of the regenerating rat liver after partial hepatectomy and also was much higher in AH 7974 cells than in the resting rat liver. In contrast, the levels of the oleate-dependent PLD activity remained constant throughout the cell cycle in liver regeneration. The intranuclear levels of the stimulating proteins of the nuclear PLD activity, e.g. ARF, RhoA, and protein kinase Cdelta increased in the S-phase of the regenerating liver. These results suggested that the nuclear ARF-dependent PLD activity may be associated with cell proliferation.
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Affiliation(s)
- Y Banno
- Department of Biochemistry, Gifu University School of Medicine, Tsukasamachi-40, Gifu 500, Japan
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41
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Suzuki M, Tamiya-Koizumi K, Takemura M, Furuta K, Izuta S, Savoysky E, Miura A, Yoshida S. Replication protein-A mediates the association of calf thymus DNA polymerase alpha-DNA primase complex with guanine-rich DNA sequence. J Biochem 1996; 120:766-72. [PMID: 8947839 DOI: 10.1093/oxfordjournals.jbchem.a021477] [Citation(s) in RCA: 3] [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: 02/03/2023] Open
Abstract
We have shown that calf thymus DNA polymerase alpha-DNA primase complex (pol alpha-primase) preferentially binds to pyrimidine-rich sequences and initiates RNA primer synthesis [Suzuki, M. et al. (1993) Biochemistry 32, 12782-12792]. Here we tested the association of pol alpha-primase with a guanine-rich DNA fragment (SVG, 30-mer) containing in vivo initiation sites of simian virus 40 DNA replication. While pyrimidine-rich fragment (CTPPS 1, 30-mer), that is a preferred sequence for calf thymus DNA primase, was well co-precipitated with pol alpha-primase using anti-pol alpha antibody, SVG was hardly precipitated under the same conditions. Competition studies in either gel-retardation assay or during de novo DNA synthesis by pol alpha-primase demonstrated that the interaction of pol alpha-primase with SVG was much weaker than that with CTPPS-1. On the other hand, replication protein-A (RP-A) could bind SVG, although less efficiently than CTPPS 1. After preincubation with RP-A, SVG could bind pol alpha-primase that was immobilized on Sepharose beads. The simian virus 40 large T antigen also enhanced association of SVG to pol alpha-primase, while Escherichia coli single-stranded DNA-binding protein did not. However, pol alpha-primase, bound to SVG in the presence of RP-A, failed to synthesize RNA primers. When SVG was extended 10 nucleotides at its 5'-end, pol alpha-primase synthesized trace amounts of RNA primers, and this activity was stimulated more than 10-fold by adding RP-A. These results suggest a new role for RP-A, i.e., as a molecular tether that allows pol alpha-primase to bind guanine-rich regions of DNA in order to initiate RNA primer synthesis.
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Affiliation(s)
- M Suzuki
- Laboratory of Cancer Cell Biology, Nagoya University School of Medicine
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42
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Oishi T, Tamiya-Koizumi K, Kudo I, Iino S, Takagi K, Yoshida S. Purification and characterization of nuclear alkaline phospholipase A2 in rat ascites hepatoma cells. FEBS Lett 1996; 394:55-60. [PMID: 8925928 DOI: 10.1016/0014-5793(96)00929-5] [Citation(s) in RCA: 9] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The alkaline phospholipase A2 (PLA2) was purified from nuclei of rat ascites hepatoma cells (AH7974) by column chromatography with a Sephacryl S-300 column and an immunoadsorbent using anti-group II PLA2 monoclonal antibody. From these two columns, the alkaline PLA2 was eluted in parallel with a 17-kDa protein which is reactive to another anti-group II PLA2 polyclonal antibody. Approximately 80% of nuclear PLA2 was inhibited by this antibody. The alkaline PLA2 was found in association with the chromatin fraction among subnuclear fractions. By an immunocytochemical staining, the nuclei of AH7974 were stained more strongly than other parts of cells with anti-group II PLA2 antiserum.
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Affiliation(s)
- T Oishi
- Second Department of Internal Medicine, Nagoya University School of Medicine, Japan
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43
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Tamiya-Koizumi K. [Sphingomyelin and its catabolism in cell nucleus: their possible roles in regulation mechanism of DNA replication]. Seikagaku 1996; 68:453-63. [PMID: 8741291] [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] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- K Tamiya-Koizumi
- Laboratory of Cancer Cell Biology, Nagoya University School of Medicine, Aichi
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44
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Abstract
We studied the effects of various phospholipids on the DNA synthesizing reactions by calf thymus DNA polymerases alpha, delta, and epsilon. Of these three enzymes, DNA polymerase epsilon was most sensitive to acidic phospholipids, i.e., phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PIP), phosphatidylserine (PS), phosphatidic acid (PA), and cardiolipin (CAR). Of these acidic phospholipids, PI (from bovine liver) is of special interest because it inhibited DNA polymerase epsilon much strongly than DNA polymerase alpha and delta. The inhibition of DNA polymerase epsilon by PI was competitive with the DNA template-primer and was noncompetitive with dTTP substrate. The Ki value was estimated to be 16 microM. These results indicate that PI from bovine liver can be used as a specific inhibitor for DNA polymerase epsilon to analyze its role in DNA replication. Interestingly, the PI isolated from soybean, which has a different fatty acid composition, inhibited not only DNA polymerase epsilon but also DNA polymerase alpha.
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Affiliation(s)
- M Shoji-Kawaguchi
- Laboratory of Cancer Cell Biology, Nagoya University School of Medicine
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45
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Abstract
We have previously shown the presence of sphingomyelin and sphingomyelinase in cell nuclei, suggesting that they may play a role in the intranuclear production of sphingosine, a potent bioactive molecule modulating diverse cellular functions. In the present study, the direct effects of sphingosine (C18:1) on the activity of DNA replication/repair polymerases were studied in vitro. Sphingosine had no effect on DNA polymerases alpha and beta and slightly inhibited DNA polymerases gamma, delta, and epsilon. In contrast, sphingosine strongly inhibited the activity of primase in a dose-dependent manner. On the other hand, dihydrosphingosine (C18:0), glycolipids, sphingomyelin, and ceramide had no effect on primase activity. Sphingosine equally inhibited the activity of primase complexed with DNA polymerase alpha, as well as its free form, with a Ki value of 4 microM. A gel-retardation analysis showed that the binding of primase with 32P-labeled template DNA was suppressed by sphingosine. Inhibition by sphingosine was competitive with the DNA template, but not with the substrate NTPs. After product analysis, a dose-dependent decrease in the amount of RNA primer products, consisting mainly of 10- and 11-mers, was observed in the presence of sphingosine, indicating that it inhibits the synthesis of RNA primers by primase. Sphingosine, however, had no effect on T7 RNA polymerase.
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Affiliation(s)
- C M Simbulan
- Laboratory of Cancer Cell Biology, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Aichi, Japan
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46
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Asano M, Tamiya-Koizumi K, Homma Y, Takenawa T, Nimura Y, Kojima K, Yoshida S. Purification and characterization of nuclear phospholipase C specific for phosphoinositides. J Biol Chem 1994; 269:12360-6. [PMID: 8163540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
A phosphoinositide-specific phospholipase C (PLC) was solubilized from the isolated nuclei of rat ascites hepatoma AH7974 cells by ultrasonication in 2 M KCl. The extract was then subjected to five steps of column chromatographies in the order of Sephacryl S-300, phosphocellulose, Mono Q, Mono S, and Superose 6. Four forms of PLC (tentatively designated as N1, N2, N3, and N4) were purified 440-1400-fold. N1, N2, N3, and N4 showed apparent molecular masses of 85, 83, 80, and 88 kDa, respectively, on SDS-polyacrylamide gel electrophoresis. N1 cross-reacted with the antibody against the delta 1 isoform, while the other three forms did not cross-react with any of the antibodies against PLC-delta 1, -gamma 1, -gamma 2, and -beta 1. They hydrolyzed phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PIP), and phosphatidylinositol 4,5-bisphosphate (PIP2) but did not show any activities against phosphatidylcholine and phosphatidylethanolamine. They showed the same optimal pH:pH 6.5 for PI hydrolysis and pH 7.0 for both PIP and PIP2 hydrolyses. They absolutely required Ca2+ for activity, with optimal concentrations of 10(-3)-10(-5) M for PIP and 10(-4)-10(-5) M for PIP2. For PI hydrolysis, N1, N2, and N3 required a Ca2+ concentration higher than 10(-2) M whereas N4 revealed significant activity even at 10(-5) M Ca2+ concentrations. Two forms of plasma membrane PLC and three forms of cytosolic PLC were purified from AH7974 cells by the same procedure as for nuclear PLC. Comparative study with these three groups revealed that all of the purified PLC isoforms shared similar enzymological properties except N4, which showed an exceptionally high affinity to Mono S column and was active at low concentrations of Ca2+ for PI as substrate. Furthermore, when PLC isoforms of nuclei from adult resting rat liver were compared with those from regenerating rat liver after partial hepatectomy, a PLC isoform corresponding to N4 of AH7974 cells was found only in regenerating liver nuclei. From these results, it was suggested that the nuclei of growing liver cells possessed a unique form of PLC (N4).
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Affiliation(s)
- M Asano
- First Department of Surgery, Nagoya University School of Medicine, Japan
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47
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Asano M, Tamiya-Koizumi K, Homma Y, Takenawa T, Nimura Y, Kojima K, Yoshida S. Purification and characterization of nuclear phospholipase C specific for phosphoinositides. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32724-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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48
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Simbulan CM, Taki T, Tamiya-Koizumi K, Suzuki M, Savoysky E, Shoji M, Yoshida S. Sulfate- and sialic acid-containing glycolipids inhibit DNA polymerase alpha activity. Biochim Biophys Acta 1994; 1205:68-74. [PMID: 8142486 DOI: 10.1016/0167-4838(94)90093-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effects of various glycolipids on the activity of immunoaffinity-purified calf thymus DNA polymerase alpha were studied in vitro. Preincubation with sialic acid-containing glycolipids, such as sialosylparagloboside (SPG), GM3, GM1, and GD1a, and sulfatide (cerebroside sulfate ester, CSE) dose-dependently inhibited the activity of DNA polymerase alpha, while other glycolipids, as well as free sphingosine and ceramide did not. About 50% inhibition was achieved by preincubating the enzyme with 2.5 microM of CSE, 50 microM of SPG or GM3, and 80 microM of GM1. Inhibition was noncompetitive with both the DNA template and the substrate dTTP, as well as with the other dNTPs. Since the inhibition was largely reversed by the addition of 0.05% Nonidet P40, these glycolipids may interact with the hydrophobic region of the enzyme protein. Apparently, the sulfate moiety in CSE and the sialic acid moiety in gangliosides were essential for the inhibition since neither neutral glycolipids (i.e., glucosylceramide, galactosylceramide, lactosylceramide) nor asialo-gangliosides (GA1 and GA2) showed any inhibitory effect. Furthermore, the ceramide backbone was also found to be necessary for maximal inhibition since the inhibition was largely abolished by substituting the lipid backbone with cholesterol. Increasing the number of sialic acid moieties per molecule further enhanced the inhibition, while elongating the sugar chain diminished it. It was clearly shown that the N-acetyl residue of the sialic acid moiety is particularly essential for inhibition by both SPG and GM3 because the loss of this residue or substitution with a glycolyl residue completely negated their inhibitory effect on DNA polymerase alpha activity.
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Affiliation(s)
- C M Simbulan
- Laboratory of Cancer Cell Biology, Nagoya University School of Medicine, Aichi, Japan
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Isomura T, Tamiya-Koizumi K, Suzuki M, Yoshida S, Taniguchi M, Matsuyama M, Ishigaki T, Sakuma S, Takahashi M. RFP is a DNA binding protein associated with the nuclear matrix. Nucleic Acids Res 1992; 20:5305-10. [PMID: 1437549 PMCID: PMC334335 DOI: 10.1093/nar/20.20.5305] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [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: 12/27/2022] Open
Abstract
We reported that the RFP gene encodes a protein with putative zinc finger domains and was involved in the activation of the ret proto-oncogene. To further characterize the RFP protein, we developed a polyclonal antibody against the product synthesized from a fragment of the RFP cDNA expressed in Escherichia coli. Western blot analysis showed that RFP was identified as a 58 kDa protein in cell lysates from four human and rodent cell lines and from mouse testis. In addition, a unique 68 kDa protein was detected in the testis. Using AH7974 (rat ascites hepatoma) and Raji (human Burkitt lymphoma) cells, we demonstrated strong association of RFP with the nuclear matrix. Furthermore, RFP solubilized from the nuclear matrix had DNA-binding activity although it appears to bind more preferentially to double-stranded DNA than to single-stranded DNA. These results thus suggest that RFP may play a role in molecular processes which occur in the nuclear matrix.
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Affiliation(s)
- T Isomura
- Department of Pathology, Nagoya University School of Medicine, Japan
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50
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Kuriki H, Tamiya-Koizumi K, Asano M, Yoshida S, Kojima K, Nimura Y. Existence of phosphoinositide-specific phospholipase C in rat liver nuclei and its change during liver regeneration. J Biochem 1992; 111:283-6. [PMID: 1316890 DOI: 10.1093/oxfordjournals.jbchem.a123750] [Citation(s) in RCA: 41] [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: 12/26/2022] Open
Abstract
We found phosphoinositide-specific phospholipase C (PtdIns-PLC) activity in nuclei isolated from rat liver. The enzyme hydrolyzed phosphatidylinositol, phosphatidylinositol 4-monophosphate (PIP) and phosphatidylinositol 4,5-bisphosphate in a Ca(2+)-dependent manner, and produced inositol mono-, bis-, and triphosphate, respectively. Neither phosphatidylcholine, phosphatidylethanolamine, nor phosphatidylserine was utilized as a substrate. After partial hepatectomy, the PtdIns-PLC activity in isolated nuclei increased transiently in the S phase (20-22 h post-hepatectomy), to 2.5-fold higher than in the control, when measured with PIP. This result suggests a close relationship between the nuclear PtdIns-PLC, especially its PIP-hydrolyzing activity, and cell proliferation.
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Affiliation(s)
- H Kuriki
- First Department of Surgery, Nagoya University School of Medicine, Aichi
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