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Katane M, Homma H. Biosynthesis and Degradation of Free D-Amino Acids and Their Physiological Roles in the Periphery and Endocrine Glands. Biol Pharm Bull 2024; 47:562-579. [PMID: 38432912 DOI: 10.1248/bpb.b23-00485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
It was long believed that D-amino acids were either unnatural isomers or laboratory artifacts, and that the important functions of amino acids were exerted only by L-amino acids. However, recent investigations have revealed a variety of D-amino acids in mammals that play important roles in physiological functions, including free D-serine and D-aspartate that are crucial in the central nervous system. The functions of several D-amino acids in the periphery and endocrine glands are also receiving increasing attention. Here, we present an overview of recent advances in elucidating the physiological roles of D-amino acids, especially in the periphery and endocrine glands.
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Affiliation(s)
- Masumi Katane
- Medicinal Research Laboratories, Graduate School of Pharmaceutical Sciences, Kitasato University
| | - Hiroshi Homma
- Laboratory of Analytical Chemistry, Graduate School of Pharmaceutical Sciences, Kitasato University
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Usiello A, Di Fiore MM, De Rosa A, Falvo S, Errico F, Santillo A, Nuzzo T, Chieffi Baccari G. New Evidence on the Role of D-Aspartate Metabolism in Regulating Brain and Endocrine System Physiology: From Preclinical Observations to Clinical Applications. Int J Mol Sci 2020; 21:E8718. [PMID: 33218144 PMCID: PMC7698810 DOI: 10.3390/ijms21228718] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
The endogenous amino acids serine and aspartate occur at high concentrations in free D-form in mammalian organs, including the central nervous system and endocrine glands. D-serine (D-Ser) is largely localized in the forebrain structures throughout pre and postnatal life. Pharmacologically, D-Ser plays a functional role by acting as an endogenous coagonist at N-methyl-D-aspartate receptors (NMDARs). Less is known about the role of free D-aspartate (D-Asp) in mammals. Notably, D-Asp has a specific temporal pattern of occurrence. In fact, free D-Asp is abundant during prenatal life and decreases greatly after birth in concomitance with the postnatal onset of D-Asp oxidase expression, which is the only enzyme known to control endogenous levels of this molecule. Conversely, in the endocrine system, D-Asp concentrations enhance after birth during its functional development, thereby suggesting an involvement of the amino acid in the regulation of hormone biosynthesis. The substantial binding affinity for the NMDAR glutamate site has led us to investigate the in vivo implications of D-Asp on NMDAR-mediated responses. Herein we review the physiological function of free D-Asp and of its metabolizing enzyme in regulating the functions of the brain and of the neuroendocrine system based on recent genetic and pharmacological human and animal studies.
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Affiliation(s)
- Alessandro Usiello
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania «L. Vanvitelli», Via Vivaldi 43, 81100 Caserta, Italy; (M.M.D.F.); (S.F.); (A.S.); (T.N.)
- CEINGE Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy;
| | - Maria Maddalena Di Fiore
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania «L. Vanvitelli», Via Vivaldi 43, 81100 Caserta, Italy; (M.M.D.F.); (S.F.); (A.S.); (T.N.)
| | - Arianna De Rosa
- CEINGE Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy;
- Department of Experimental Medicine, Sapienza University of Rome, 00185 Rome, Italy
| | - Sara Falvo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania «L. Vanvitelli», Via Vivaldi 43, 81100 Caserta, Italy; (M.M.D.F.); (S.F.); (A.S.); (T.N.)
| | - Francesco Errico
- Dipartimento di Agraria, Università degli Studi di Napoli Federico II, Via Università, 100, 80055 Portici, Italy;
| | - Alessandra Santillo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania «L. Vanvitelli», Via Vivaldi 43, 81100 Caserta, Italy; (M.M.D.F.); (S.F.); (A.S.); (T.N.)
| | - Tommaso Nuzzo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania «L. Vanvitelli», Via Vivaldi 43, 81100 Caserta, Italy; (M.M.D.F.); (S.F.); (A.S.); (T.N.)
- CEINGE Biotecnologie Avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy;
| | - Gabriella Chieffi Baccari
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania «L. Vanvitelli», Via Vivaldi 43, 81100 Caserta, Italy; (M.M.D.F.); (S.F.); (A.S.); (T.N.)
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Chieffi Baccari G, Falvo S, Santillo A, Di Giacomo Russo F, Di Fiore MM. D-Amino acids in mammalian endocrine tissues. Amino Acids 2020; 52:1263-1273. [PMID: 32930873 DOI: 10.1007/s00726-020-02892-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/07/2020] [Indexed: 01/05/2023]
Abstract
D-Aspartate, D-serine and D-alanine are a regular occurrence in mammalian endocrine tissues, though in amounts varying with the type of gland. The pituitary gland, pineal gland, thyroid, adrenal glands and testis contain relatively large amounts of D-aspartate in all species examined. D-alanine is relatively abundant in the pituitary gland and pancreas. High levels of D-serine characterize the hypothalamus. D-leucine, D-proline and D-glutamate are generally low. The current knowledge of physiological roles of D-amino acids in endocrine tissues is far from exhaustive, yet the topic is attracting increasing interest because of its potential in pharmacological application. D-aspartate is known to act at all levels of the hypothalamus-pituitary-testis axis, playing a key role in reproductive biology in several vertebrate classes. An involvement of D-amino acids in the endocrine function of the pancreas is emerging. D-Aspartate has been immunolocalized in insulin-containing secretory granules in INS-1 E clonal β cells and is co-secreted with insulin by exocytosis. Specific immunolocalization of D-alanine in pituitary ACTH-secreting cells and pancreatic β-cells suggests that this amino acid participates in blood glucose regulation in mammals. By modulating insulin secretion, D-serine probably participates in the control of systemic glucose metabolism by modulating insulin secretion. We anticipate that future investigation will significantly increase the functional repertoire of D-amino acids in homeostatic control.
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Affiliation(s)
- Gabriella Chieffi Baccari
- Dip. Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Via Vivaldi, 43, 81100, Caserta, Italy
| | - Sara Falvo
- Dip. Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Via Vivaldi, 43, 81100, Caserta, Italy
| | - Alessandra Santillo
- Dip. Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Via Vivaldi, 43, 81100, Caserta, Italy
| | - Federica Di Giacomo Russo
- Dip. Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Via Vivaldi, 43, 81100, Caserta, Italy
| | - Maria Maddalena Di Fiore
- Dip. Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Via Vivaldi, 43, 81100, Caserta, Italy.
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Lin CE, Chang WS, Lee JA, Chang TY, Huang YS, Hirasaki Y, Chen HS, Imai K, Chen SM. Proteomics analysis of altered proteins in kidney of mice with aristolochic acid nephropathy using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method. Biomed Chromatogr 2018; 32. [PMID: 29088495 DOI: 10.1002/bmc.4127] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/03/2017] [Accepted: 10/18/2017] [Indexed: 01/22/2023]
Abstract
Aristolochic acid (AA) causes interstitial renal fibrosis, called aristolochic acid nephropathy (AAN). There is no specific indicator for diagnosing AAN, so this study aimed to investigate the biomarkers for AAN using a proteomics method. The C3H/He female mice were given ad libitum AA-distilled water (0.5 mg/kg/day) and distilled water for 56 days in the AA and normal groups, respectively. The AA-induced proteins in the kidney were investigated using a proteomics study, including fluorogenic derivatization with 7-chloro-N-[2-(dimethylamino)ethyl]-2,1,3-benzoxadiazole-4-sulfonamide, followed by high-performance liquid chromatography analysis and liquid chromatography tandem mass spectrometry with a MASCOT database searching system. There were two altered proteins, thrombospondin type 1 (TSP1) and G protein-coupled receptor 87 (GPR87), in the kidney of AA-group mice on day 56. GPR87, a tumorigenesis-related protein, is reported for the first time in the current study. The renal interstitial fibrosis was certainly induced in the AA-group mice under histological examination. Based on the results of histological examination and the proteomics study, this model might be applied to AAN studies in the future. TSP1 might be a novel biomarker for AAN, and the further role of GPR87 leading to AA-induced tumorigenesis should be researched in future studies.
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Affiliation(s)
- Chia-En Lin
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Wen-Shin Chang
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Jen-Ai Lee
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Ting-Ya Chang
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Yu-Shen Huang
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Yoshiro Hirasaki
- Department of Japanese-oriental Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Hung-Shing Chen
- Graduate Institute of Electro-optical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan
| | - Kazuhiro Imai
- Research Institute of Pharmaceutical Sciences, Musashino University, Tokyo, Japan
| | - Shih-Ming Chen
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
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Tomita K, Tanaka H, Kageyama S, Nagasawa M, Wada A, Murai R, Kobayashi K, Hanada E, Agata Y, Kawauchi A. The Effect of d-Aspartate on Spermatogenesis in Mouse Testis1. Biol Reprod 2016; 94:30. [DOI: 10.1095/biolreprod.115.134692] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/07/2015] [Indexed: 11/01/2022] Open
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Abousaab A, Warsi J, Elvira B, Lang F. Caveolin-1 Sensitivity of Excitatory Amino Acid Transporters EAAT1, EAAT2, EAAT3, and EAAT4. J Membr Biol 2015; 249:239-49. [PMID: 26690923 DOI: 10.1007/s00232-015-9863-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022]
Abstract
Excitatory amino acid transporters EAAT1 (SLC1A3), EAAT2 (SLC1A2), EAAT3 (SLC1A1), and EAAT4 (SLC1A6) serve to clear L-glutamate from the synaptic cleft and are thus important for the limitation of neuronal excitation. EAAT3 has previously been shown to form complexes with caveolin-1, a major component of caveolae, which participate in the regulation of transport proteins. The present study explored the impact of caveolin-1 on electrogenic transport by excitatory amino acid transporter isoforms EAAT1-4. To this end cRNA encoding EAAT1, EAAT2, EAAT3, or EAAT4 was injected into Xenopus oocytes without or with additional injection of cRNA encoding caveolin-1. The L-glutamate (2 mM)-induced inward current (I Glu) was taken as a measure of glutamate transport. As a result, I Glu was observed in EAAT1-, EAAT2-, EAAT3-, or EAAT4-expressing oocytes but not in water-injected oocytes, and was significantly decreased by coexpression of caveolin-1. Caveolin-1 decreased significantly the maximal transport rate. Treatment of EAATs-expressing oocytes with brefeldin A (5 µM) was followed by a decrease in conductance, which was similar in oocytes expressing EAAT together with caveolin-1 as in oocytes expressing EAAT1-4 alone. Thus, caveolin-1 apparently does not accelerate transporter protein retrieval from the cell membrane. In conclusion, caveolin-1 is a powerful negative regulator of the excitatory glutamate transporters EAAT1, EAAT2, EAAT3, and EAAT4.
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Affiliation(s)
- Abeer Abousaab
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Jamshed Warsi
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Bernat Elvira
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Florian Lang
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany.
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Abousaab A, Warsi J, Elvira B, Alesutan I, Hoseinzadeh Z, Lang F. Down-Regulation of Excitatory Amino Acid Transporters EAAT1 and EAAT2 by the Kinases SPAK and OSR1. J Membr Biol 2015; 248:1107-19. [PMID: 26233565 DOI: 10.1007/s00232-015-9826-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/24/2015] [Indexed: 11/27/2022]
Abstract
SPAK (SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase 1) are cell volume-sensitive kinases regulated by WNK (with-no-K[Lys]) kinases. SPAK/OSR1 regulate several channels and carriers. SPAK/OSR1 sensitive functions include neuronal excitability. Orchestration of neuronal excitation involves the excitatory glutamate transporters EAAT1 and EAAT2. Sensitivity of those carriers to SPAK/OSR1 has never been shown. The present study thus explored whether SPAK and/or OSR1 contribute to the regulation of EAAT1 and/or EAAT2. To this end, cRNA encoding EAAT1 or EAAT2 was injected into Xenopus oocytes without or with additional injection of cRNA encoding wild-type SPAK or wild-type OSR1, constitutively active (T233E)SPAK, WNK insensitive (T233A)SPAK, catalytically inactive (D212A)SPAK, constitutively active (T185E)OSR1, WNK insensitive (T185A)OSR1 or catalytically inactive (D164A)OSR1. The glutamate (2 mM)-induced inward current (I Glu) was taken as a measure of glutamate transport. As a result, I Glu was observed in EAAT1- and in EAAT2-expressing oocytes but not in water-injected oocytes, and was significantly decreased by coexpression of SPAK and OSR1. As shown for EAAT2, SPAK, and OSR1 decreased significantly the maximal transport rate but significantly enhanced the affinity of the carrier. The effect of wild-type SPAK/OSR1 on EAAT1 and EAAT2 was mimicked by (T233E)SPAK and (T185E)OSR1, but not by (T233A)SPAK, (D212A)SPAK, (T185A)OSR1, or (D164A)OSR1. Coexpression of either SPAK or OSR1 decreased the EAAT2 protein abundance in the cell membrane of EAAT2-expressing oocytes. In conclusion, SPAK and OSR1 are powerful negative regulators of the excitatory glutamate transporters EAAT1 and EAAT2.
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Affiliation(s)
- Abeer Abousaab
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Jamshed Warsi
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Bernat Elvira
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Ioana Alesutan
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Zohreh Hoseinzadeh
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Florian Lang
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany.
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Warsi J, Luo D, Elvira B, Jilani K, Shumilina E, Hosseinzadeh Z, Lang F. Upregulation of excitatory amino acid transporters by coexpression of Janus kinase 3. J Membr Biol 2014; 247:713-20. [PMID: 24928228 DOI: 10.1007/s00232-014-9695-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/26/2014] [Indexed: 10/25/2022]
Abstract
Janus kinase 3 (JAK3) contributes to cytokine receptor signaling, confers cell survival and stimulates cell proliferation. The gain of function mutation JAK3(A572V) is found in acute megakaryoplastic leukemia. Replacement of ATP coordinating lysine by alanine yields inactive JAK3(K855A). Most recent observations revealed the capacity of JAK3 to regulate ion transport. This study thus explored whether JAK3 regulates glutamate transporters EAAT1-4, carriers accomplishing transport of glutamate and aspartate in a variety of cells including intestinal cells, renal cells, glial cells, and neurons. To this end, EAAT1, 2, 3, or 4 were expressed in Xenopus oocytes with or without additional expression of mouse wild-type JAK3, constitutively active JAK3(A568V) or inactive JAK3(K851A), and electrogenic glutamate transport was determined by dual electrode voltage clamp. Moreover, Ussing chamber was employed to determine electrogenic glutamate transport in intestine from mice lacking functional JAK3 (jak3(-/-)) and from corresponding wild-type mice (jak3(+/+)). As a result, in EAAT1, 2, 3, or 4 expressing oocytes, but not in oocytes injected with water, addition of glutamate to extracellular bath generated an inward current (Ig), which was significantly increased following coexpression of JAK3. Ig in oocytes expressing EAAT3 was further increased by JAK3(A568V) but not by JAK3(K851A). Ig in EAAT3 + JAK3 expressing oocytes was significantly decreased by JAK3 inhibitor WHI-P154 (22 µM). Kinetic analysis revealed that JAK3 increased maximal Ig and significantly reduced the glutamate concentration required for half maximal Ig (Km). Intestinal electrogenic glutamate transport was significantly lower in jak3(-/-) than in jak3(+/+) mice. In conclusion, JAK3 is a powerful regulator of excitatory amino acid transporter isoforms.
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Affiliation(s)
- Jamshed Warsi
- Department of Physiology I, University of Tuebingen, Gmelinstr. 5, 72076, Tuebingen, Germany
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Current knowledge of d-aspartate in glandular tissues. Amino Acids 2014; 46:1805-18. [DOI: 10.1007/s00726-014-1759-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 04/28/2014] [Indexed: 12/24/2022]
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Hosseinzadeh Z, Bhavsar SK, Sopjani M, Alesutan I, Saxena A, Dërmaku-Sopjani M, Lang F. Regulation of the glutamate transporters by JAK2. Cell Physiol Biochem 2011; 28:693-702. [PMID: 22178881 DOI: 10.1159/000335763] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2011] [Indexed: 01/13/2023] Open
Abstract
The Janus-activated kinase-2 JAK2 is involved in the signaling of leptin and erythropoietin receptors and mediates neuroprotective effects of the hormones. In theory, JAK2 could be effective through modulation of the glutamate transporters, carriers accounting for the clearance of glutamate released during neurotransmission. The present study thus elucidated the effect of JAK2 on the glutamate transporters EAAT1, EAAT2, EAAT3 and EAAT4. To this end, cRNA encoding the carriers was injected into Xenopus oocytes with or without cRNA encoding JAK2 and glutamate transport was estimated from glutamate induced current (I(glu)). I(glu) was observed in Xenopus oocytes expressing EAAT1 or EAAT2 or EAAT3 or EAAT4, but not in water injected oocytes. Coexpression of JAK2 resulted in an increase of I(glu) by 83% (EAAT1), 67% (EAAT2), 42% (EAAT3) and 126% (EAAT4). As shown for EAAT4 expressing Xenopus oocytes, the effect of JAK2 was mimicked by gain of function mutation (V617F)JAK2 but not by the inactive mutant (K882E)JAK2. Incubation with JAK2 inhibitor AG490 (40 μM) resulted in a gradual decrease of I(glu) by 53%, 79% and 92% within 3, 6 and 24 hours. Confocal microscopy and chemiluminescence analysis revealed that JAK2 coexpression increased EAAT4 protein abundance in the cell membrane. Disruption of transcription did not appreciably modify the up-regulation of I(glu) in EAAT4 expressing oocytes. The decay of I(glu) following inhibition of carrier insertion with brefeldin A was similar in oocytes expressing EAAT4 + JAK2 and oocytes expressing EAAT4 alone, indicating that JAK2 did not appreciably affect carrier retrieval from the membrane. In conclusion, JAK2 is a novel powerful regulator of glutamate transporters and thus participates in the protection against excitotoxicity.
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Affiliation(s)
- Zohreh Hosseinzadeh
- Department of Physiology, University of Tübingen, Gmelinstrasse 5, Tübingen, Germany
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Katane M, Homma H. D-Aspartate--an important bioactive substance in mammals: a review from an analytical and biological point of view. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3108-21. [PMID: 21524944 DOI: 10.1016/j.jchromb.2011.03.062] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 03/23/2011] [Accepted: 03/30/2011] [Indexed: 01/08/2023]
Abstract
It was long believed that D-amino acids were either unnatural isomers or laboratorial artifacts and that the important functions of amino acids were exerted only by l-amino acids. However, recent investigations have shown that a variety of D-amino acids are present in mammals and that they play important roles in physiological functions in the body. Among the free d-amino acids that have been identified in mammals, D-aspartate (D-Asp) has been shown to play a crucial role in the neuroendocrine and endocrine systems as well as in the central nervous system. Here, we present an overview of recent studies of free D-Asp, focusing on the analytical methods in real biological matrices, expression and localization in tissues and cells, biological and physiological activities, biosynthesis, degradation, cellular transport, and possible relevance to disease. In addition to frequently used techniques for the enantiomeric determination of amino acids, including high-performance liquid chromatography and enzymatic methods, the recent development of analytical methods is also described.
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Affiliation(s)
- Masumi Katane
- Laboratory of Biomolecular Science, Department of Pharmaceutical Life Sciences, Kitasato University, 5-9-1 Shirokane, Tokyo 108-8641, Japan
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Oliván A, Pérez-Rodríguez R, Roncero C, Arce C, González M, Oset-Gasque M. Plasma membrane and vesicular glutamate transporter expression in chromaffin cells of bovine adrenal medulla. J Neurosci Res 2010; 89:44-57. [DOI: 10.1002/jnr.22529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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13
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D-Aspartate Oxidase: The Sole Catabolic Enzyme Acting on Free D-Aspartate in Mammals. Chem Biodivers 2010; 7:1435-49. [DOI: 10.1002/cbdv.200900250] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Evidence for the involvement of d-aspartic acid in learning and memory of rat. Amino Acids 2009; 38:1561-9. [DOI: 10.1007/s00726-009-0369-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2009] [Accepted: 10/10/2009] [Indexed: 10/20/2022]
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15
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Ji X, Jin Y, Chen Y, Li C, Guo L. Existence of an endogenous glutamate and aspartate transporter in Chinese hamster ovary cells. Acta Biochim Biophys Sin (Shanghai) 2007; 39:851-6. [PMID: 17989876 DOI: 10.1111/j.1745-7270.2007.00354.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Chinese hamster ovary cells show endogenous high-affinity Na(+)-dependent glutamate transport activity. This transport activity is kinetically similar to a glutamate transporter family strategically expressed in the central nervous system and is pharmacologically unlike glutamate transporter-1 or excitatory amino acid carrier 1. The cDNA of a glutamate/aspartate transporter (GLAST)-like transporter was obtained and analyzed. The deduced amino acid sequence showed high similarity to human, mouse, and rat GLAST. We concluded that a GLAST-like glutamate transporter exists in Chinese hamster ovary cells that might confer the endogenous high-affinity Na(+)-dependent glutamate transport activity evident in these cells.
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Affiliation(s)
- Xunhe Ji
- Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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16
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D'Aniello A. d-Aspartic acid: An endogenous amino acid with an important neuroendocrine role. ACTA ACUST UNITED AC 2007; 53:215-34. [PMID: 17118457 DOI: 10.1016/j.brainresrev.2006.08.005] [Citation(s) in RCA: 197] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 07/14/2006] [Accepted: 08/04/2006] [Indexed: 12/01/2022]
Abstract
D-Aspartic acid (d-Asp), an endogenous amino acid present in vertebrates and invertebrates, plays an important role in the neuroendocrine system, as well as in the development of the nervous system. During the embryonic stage of birds and the early postnatal life of mammals, a transient high concentration of d-Asp takes place in the brain and in the retina. d-Asp also acts as a neurotransmitter/neuromodulator. Indeed, this amino acid has been detected in synaptosomes and in synaptic vesicles, where it is released after chemical (K(+) ion, ionomycin) or electric stimuli. Furthermore, d-Asp increases cAMP in neuronal cells and is transported from the synaptic clefts to presynaptic nerve cells through a specific transporter. In the endocrine system, instead, d-Asp is involved in the regulation of hormone synthesis and release. For example, in the rat hypothalamus, it enhances gonadotropin-releasing hormone (GnRH) release and induces oxytocin and vasopressin mRNA synthesis. In the pituitary gland, it stimulates the secretion of the following hormones: prolactin (PRL), luteinizing hormone (LH), and growth hormone (GH) In the testes, it is present in Leydig cells and is involved in testosterone and progesterone release. Thus, a hypothalamus-pituitary-gonads pathway, in which d-Asp is involved, has been formulated. In conclusion, the present work is a summary of previous and current research done on the role of d-Asp in the nervous and endocrine systems of invertebrates and vertebrates, including mammals.
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Affiliation(s)
- Antimo D'Aniello
- Laboratory of Neurobiology, Stazione Zoologica A Dohrn, Villa Comunale 1, 80121 Napoli, Italy.
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17
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Iharada M, Hiasa M, Kobara A, Moriyama Y. Exocytosis of D-Aspartate from INS-1E Clonal .BETA. Cells. Biol Pharm Bull 2007; 30:1329-31. [PMID: 17603175 DOI: 10.1248/bpb.30.1329] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
D-Aspartate is present in the central nervous system and various endocrine organs, and modulates their neuroendocrine function. In islets of Langerhans, alpha and beta cells contain D-aspartate. Here we show that INS-1E clonal beta cells contain the highest amount of D-aspartate. Immunohistochemical analysis with specific antibodies against D-aspartate indicated that D-aspartate is co-localized with insulin. Upon the addition of K(+), both D-aspartate and insulin are secreted from the cells in a Ca(2+)-dependent manner. A Ca(2+) ionophore, A23187, also triggers the release of D-aspartate and insulin in the presence of Ca(2+). Bafilomycin A(1), a specific inhibitor of V-ATPase and V-ATPase-linked secondary transport, inhibits the secretion of D-aspartate. These results support the idea that D-aspartate is present in insulin-containing secretory granules and co-secreted with insulin through exocytosis.
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Affiliation(s)
- Masafumi Iharada
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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18
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Ohgusu T, Hamase K, Tanaka H, Shoyama Y, Zaitsu K. High-throughput determination of free d-aspartic acid in mammals by enzyme immunoassay using specific monoclonal antibody. Anal Biochem 2006; 357:15-20. [PMID: 16920063 DOI: 10.1016/j.ab.2006.06.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2006] [Revised: 06/29/2006] [Accepted: 06/30/2006] [Indexed: 10/24/2022]
Abstract
A method for rapid determination of free D-aspartic acid (D-Asp) in mammals has been established using a highly specific mouse monoclonal antibody against D-Asp for the first time. An anti-D-Asp monoclonal antibody was obtained by the immunization of bovine-serum-albumin-conjugated D-Asp to BALB/c mice. The obtained antibody has a high specificity toward D-Asp but shows a slight cross-reactivity to all other D- and L- amino acids including L-Asp. The calibration range of the competitive enzyme linked immunosorbent assay (ELISA) is 0.016-16 micromol/mL D-Asp in rat serum samples. The precisions of this method were evaluated by inter-plate and intraplate assays, and the relative standard deviation values were 4.8% and 4.5%, respectively. The values of D-Asp determined by the present ELISA have a good correlation to those determined by high-performance liquid chromatography with the correlation coefficient of 0.963. Using this ELISA, the time course of D-Asp in the rat serum after intravenous administration was successfully demonstrated. The present method provides a simple and high-throughput determination of D-Asp in mammals, and is a useful tool for clarifying the physiological roles and diagnostic values of this D-amino acid.
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Affiliation(s)
- Tomohiro Ohgusu
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Fukuoka 812-8582, Japan
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19
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Morikawa A, Hamase K, Inoue T, Konno R, Zaitsu K. Alterations in D-amino acid levels in the brains of mice and rats after the administration of D-amino acids. Amino Acids 2006; 32:13-20. [PMID: 16755370 DOI: 10.1007/s00726-005-0357-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Accepted: 11/29/2005] [Indexed: 11/26/2022]
Abstract
To mutant ddY/DAO(-) mice lacking D-amino-acid oxidase activity and normal ddY/DAO(+) mice, five D-amino acids (D-Asp, D-Ser, D-Ala, D-Leu and D-Pro) were orally administered for two weeks, and the D-amino acid levels were examined in seven brain regions. The levels of D-Asp markedly increased in the pituitary and pineal glands in both strains. In the ddY/DAO(+) mice, the levels of the other D-amino acids did not significantly change in most of the brain regions. While in the ddY/DAO(-) mice the levels of D-Ser significantly increased in most of the brain regions except for the cerebrum and hippocampus. The levels of D-Ala and D-Leu increased in all regions but the levels of D-Pro did not significantly change. The same five D-amino acids were intravenously injected into Wistar rats and the D-amino acid levels in their brains were examined for 60 min after the administration. The levels of D-Asp markedly increased in the pineal gland 3 min after the administration, while the levels of D-Ser, D-Ala, and D-Pro increased both in the pineal and pituitary glands, the levels of D-Leu increased in all brain regions. These results are useful for the elucidation of the origins and regulation of D-amino acids in the mammalian body.
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Affiliation(s)
- A Morikawa
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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20
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Homma H. Biochemistry of D-aspartate in mammalian cells. Amino Acids 2006; 32:3-11. [PMID: 16755369 DOI: 10.1007/s00726-006-0354-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Accepted: 01/10/2006] [Indexed: 12/23/2022]
Abstract
Recent investigations have shown that D-aspartate (D-Asp) plays an important physiological role(s) in the mammalian body. Here, several recent studies of free D-Asp metabolism in mammals, focusing on cellular localization in tissues, intracellular localization, biosynthesis, efflux, uptake and degradation are reviewed. D-Asp in mammalian tissues is present in specific cells, indicating the existence of specific molecular components that regulate D-Asp levels and localization in tissues. In the rat pheochromocytoma cell line (PC12) and its subclones, D-Asp is synthesized intracellularly, most likely by Asp racemase(s). Endogenous D-Asp apparently has two different intracellular localization patterns: cytoplasmic and vesicular. In PC12 cells, D-Asp release can occur through three distinct pathways: 1) spontaneous, continuous release of cytoplasmic D-Asp, which is not associated with a specific stimulus; 2) release of cytoplasmic D-Asp via a volume-sensitive organic anion channel that connects the cytoplasm and extracellular space; 3) exocytotic discharge of vesicular D-Asp. Under certain conditions, D-Asp can be released via a mechanism that involves the L-Glu transporter. D-Asp is thus apparently in dynamic flux at the cellular level to carry out its physiological function(s) in mammals.
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Affiliation(s)
- H Homma
- Laboratory of Biomolecular Science, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan.
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21
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Buschiazzo A, Goytia M, Schaeffer F, Degrave W, Shepard W, Grégoire C, Chamond N, Cosson A, Berneman A, Coatnoan N, Alzari PM, Minoprio P. Crystal structure, catalytic mechanism, and mitogenic properties of Trypanosoma cruzi proline racemase. Proc Natl Acad Sci U S A 2006; 103:1705-10. [PMID: 16446443 PMCID: PMC1413642 DOI: 10.1073/pnas.0509010103] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Indexed: 11/18/2022] Open
Abstract
Amino acid racemases catalyze the stereoinversion of the chiral C alpha to produce the d-enantiomers that participate in biological processes, such as cell wall construction in prokaryotes. Within this large protein family, bacterial proline racemases have been extensively studied as a model of enzymes acting with a pyridoxal-phosphate-independent mechanism. Here we report the crystal structure of the proline racemase from the human parasite Trypanosoma cruzi (TcPRACA), a secreted enzyme that triggers host B cell polyclonal activation, which prevents specific humoral immune responses and is crucial for parasite evasion and fate. The enzyme is a homodimer, with each monomer folded in two symmetric alpha/beta subunits separated by a deep crevice. The structure of TcPRACA in complex with a transition-state analog, pyrrole-2-carboxylic acid, reveals the presence of one reaction center per monomer, with two Cys residues optimally located to perform acid/base catalysis through a carbanion stabilization mechanism. Mutation of the catalytic Cys residues abolishes the enzymatic activity but preserves the mitogenic properties of the protein. In contrast, inhibitor binding promotes the closure of the interdomain crevice and completely abrogates B cell proliferation, suggesting that the mitogenic properties of TcPRACA depend on the exposure of transient epitopes in the ligand-free enzyme.
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Affiliation(s)
| | - Maira Goytia
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - Francis Schaeffer
- *Unité de Biochimie Structurale, Unité de Recherche Associeé 2185, and
| | - Wim Degrave
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - William Shepard
- European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, F-38043 Grenoble, France
| | - Christophe Grégoire
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - Nathalie Chamond
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - Alain Cosson
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - Armand Berneman
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - Nicolas Coatnoan
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
| | - Pedro M. Alzari
- *Unité de Biochimie Structurale, Unité de Recherche Associeé 2185, and
| | - Paola Minoprio
- Unité d’Immunophysio-pathologie Infectieuse, Unité de Recherche Associeé 1961, Centre National de la Recherche Scientifique/Institut Pasteur, 25 Rue du Dr. Roux, F-75724 Paris, France; and
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22
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Koyama H, Adachi M, Sekine M, Katane M, Furuchi T, Homma H. Cytoplasmic localization and efflux of endogenous d-aspartate in pheochromocytoma 12 cells. Arch Biochem Biophys 2006; 446:131-9. [PMID: 16427600 DOI: 10.1016/j.abb.2005.12.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 12/09/2005] [Accepted: 12/15/2005] [Indexed: 11/16/2022]
Abstract
In our previous reports [Z. Long, H. Homma, J.-A. Lee, T. Fukushima, T. Santa, T. Iwatsubo, R. Yamada, K. Imai, FEBS Lett. 434 (1998) 231-235; Z. Long, M. Sekine, M. Adachi, T. Furuchi, K. Imai, N. Nimura, H. Homma, Arch. Biochem. Biophys. 404 (2002) 92-97], we demonstrated for the first time that D-aspartate (D-Asp) is actually synthesized in cultured mammalian cells such as PC12, MPT1, and GH3 cells. After its synthesis, this unique amino acid is spontaneously and continuously released into the extracellular space during cell culture. In the current study, we characterized two different types of D-Asp efflux in PC12 cells. One is a spontaneous and continuous form of release of cytoplasmic origin that does not involve exocytotic efflux of vesicular origin. Endogenous D-Asp is predominantly localized to the cytoplasm of cells, and this form of D-Asp release presents a striking contrast to exocytotic, quantal discharge of vesicular dopamine. The other form of efflux is also of cytoplasmic origin and occurs through volume-sensitive organic anion channels that are opened upon hyposmotic stimuli. Interestingly, this latter form of efflux is potentiated by acetylcholine stimulation.
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Affiliation(s)
- H Koyama
- Laboratory of Biomolecular Science, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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23
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Hiasa M, Moriyama Y. Immunohistochemical Localization of D-Aspartate in Islets of Langerhans. Biol Pharm Bull 2006; 29:1251-3. [PMID: 16755027 DOI: 10.1248/bpb.29.1251] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
D-aspartate is a putative modulator of neuroendocrine functions, and is present in various neuroendocrine cells as well as the central nervous system. Here we show that the islet of Langerhans is a D-aspartate-containing endocrine organ. Immunohistochemical analysis with specific antibodies against D-aspartate indicated that D-aspartate is present in all islet cells, and predominantly present in alpha cells and a subpopulation of F-cells. Since these cells are glutamatergic in nature, it is possible that D-aspartate is involved in the glutamate signaling pathways in the islets.
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Affiliation(s)
- Miki Hiasa
- Laboratory of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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24
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Kalariti N, Pissimissis N, Koutsilieris M. The glutamatergic system outside the CNS and in cancer biology. Expert Opin Investig Drugs 2005; 14:1487-96. [PMID: 16307489 DOI: 10.1517/13543784.14.12.1487] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Glutamate is a major excitatory neurotransmitter in the CNS. The signalling machinery consists of: glutamate receptors, which are responsible for signal input; plasma glutamate transporters, which are responsible for signal termination; and vesicular glutamate transporters for signal output through exocytic release. Recently, data have suggested that the glutamatergic system plays an important role in non-neuronal tissues. In addition, the expression of glutamatergic system has been implicated in tumour biology. This review outlines the evidence, which suggests that the glutamatergic system may have an important role in cancer biology.
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Affiliation(s)
- Niki Kalariti
- Department of Experimental Physiology, Medical School, University of Athens, 75 Micras Asias, Goudi-Athens, Greece
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25
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Koyama H, Sekine M, Furuchi T, Katane M, Nimura N, Shimamoto K, Nakajima T, Homma H. A novel L-glutamate transporter inhibitor reveals endogenous D-aspartate homeostasis in rat pheochromocytoma MPT1 cells. Life Sci 2005; 76:2933-44. [PMID: 15820504 DOI: 10.1016/j.lfs.2004.10.057] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Accepted: 10/26/2004] [Indexed: 11/20/2022]
Abstract
We previously reported for the first time that D-aspartate (D-Asp) is biosynthesized by cultured mammalian cells such as pheochromocytoma (PC)12 cells and its subclone MPT1 (FEBS Lett. 434 (1998) 231, Arch. Biochem. Biophys. 404 (2002) 92). We speculated that D-Asp levels in the intra- and extracellular spaces of the cultured cells are maintained in a dynamic state of homeostasis. To test this here, we utilized a novel and potent L-Glu transporter inhibitor, TFB-TBOA. This inhibitor proved to be a genuine nontransportable blocker of the transporter even during long periods of culture. Use of this inhibitor with MPT1 cells confirmed that D-Asp levels are in a dynamic steady state where it is constantly released into the extracellular space by a yet undefined mechanism as well as being constantly and intensively taken up by the cells via the L-Glu transporter. We estimated the rate with which D-Asp is constitutively released from MPT1 cells is approx. 3.8 pmol/h/1x10(5) cells.
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Affiliation(s)
- Hayato Koyama
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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26
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Abstract
D-Aspartate (D-Asp) is an endogenous amino acid present in nervous and endocrine tissues in mammals. A high concentration of D-Asp is observed in embryos, which disappears in nervous tissues after delivery, but increases temporarily in endocrine glands, particularly in the pituitary, pineal and adrenal glands at the specific stages. In the pineal gland, D-Asp that is apparently derived from other tissues suppresses melatonin secretion from parenchymal cells. Additionally, D-Asp levels increase in the testis just before birth and during maturation. The amino acid is presumed to be synthesized by the pituitary gland and testis. In the testis, D-Asp produced inside the seminiferous tubules acts on Leydig cells following release to enhance testosterone synthesis by activating the expression of Steroidogenic Acute Regulatory protein. Mammalian cells appear to contain all the molecular components required to regulate D-Asp homeostasis, as they can synthesize, release, take up, and degrade the amino acid. These findings collectively indicate that D-Asp is a novel type of messenger in the mammalian body.
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Affiliation(s)
- Takemitsu Furuchi
- Laboratory of Biomolecular Science, School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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27
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Adachi M, Koyama H, Long Z, Sekine M, Furuchi T, Imai K, Nimura N, Shimamoto K, Nakajima T, Homma H. l-Glutamate in the extracellular space regulates endogenous d-aspartate homeostasis in rat pheochromocytoma MPT1 cells. Arch Biochem Biophys 2004; 424:89-96. [PMID: 15019840 DOI: 10.1016/j.abb.2004.01.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2003] [Revised: 01/24/2004] [Indexed: 12/25/2022]
Abstract
In previous studies [FEBS Lett. 434 (1998) 231, Arch. Biochem. Biophys. 404 (2002) 92], we demonstrated for the first time that D-aspartate (D-Asp) is synthesized in cultured mammalian cell lines, such as pheochromocytoma 12 (PC12) and its subclone, MPT1. Our current focus is analysis of the dynamics of D-Asp homeostasis in these cells. In this communication, we show that L-glutamate (Glu) and L-Glu transporter substrates in the extracellular space regulate the homeostasis of endogenous D-Asp in MPT1 cells. D-Asp is apparently in dynamic homeostasis, whereby endogenous D-Asp is constantly released into the extracellular space by an undefined mechanism, and continuously and intensively taken up into cells by an L-Glu transporter. Under these conditions, L-Glu and its transporter substrates in the medium may competitively inhibit the uptake of D-Asp via the transporter, resulting in accumulation of the amino acid in the extracellular space. We additionally demonstrate that DL-TBOA, a well-established L-Glu transporter inhibitor, is taken up by the transporter during long time intervals, but not on a short time-scale.
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Affiliation(s)
- Minako Adachi
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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28
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Hinoi E, Takarada T, Ueshima T, Tsuchihashi Y, Yoneda Y. Glutamate signaling in peripheral tissues. ACTA ACUST UNITED AC 2004; 271:1-13. [PMID: 14686914 DOI: 10.1046/j.1432-1033.2003.03907.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The hypothesis that l-glutamate (Glu) is an excitatory amino acid neurotransmitter in the mammalian central nervous system is now gaining more support after the successful cloning of a number of genes coding for the signaling machinery required for this neurocrine at synapses in the brain. These include Glu receptors (signal detection), Glu transporters (signal termination) and vesicular Glu transporters (signal output through exocytotic release). Relatively little attention has been paid to the functional expression of these molecules required for Glu signaling in peripheral neuronal and non-neuronal tissues; however, recent molecular biological analyses show a novel function for Glu as an extracellular signal mediator in the autocrine and/or paracrine system. Emerging evidence suggests that Glu could play a dual role in mechanisms underlying the maintenance of cellular homeostasis - as an excitatory neurotransmitter in the central neurocrine system and an extracellular signal mediator in peripheral autocrine and/or paracrine tissues. In this review, the possible Glu signaling methods are outlined in specific peripheral tissues including bone, testis, pancreas, and the adrenal, pituitary and pineal glands.
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Affiliation(s)
- Eiichi Hinoi
- Laboratory of Molecular Pharmacology, Kanazawa University Graduate School of Natural Science and Technology, Kanazawa, Ishikawa, Japan
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29
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30
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Boehmer C, Henke G, Schniepp R, Palmada M, Rothstein JD, Bröer S, Lang F. Regulation of the glutamate transporter EAAT1 by the ubiquitin ligase Nedd4-2 and the serum and glucocorticoid-inducible kinase isoforms SGK1/3 and protein kinase B. J Neurochem 2003; 86:1181-8. [PMID: 12911626 DOI: 10.1046/j.1471-4159.2003.01937.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Surface expression of the glial glutamate transporter EAAT1 is stimulated by insulin-like growth factor 1 through activation of phosphatidylinositol-3-kinase. Downstream targets include serum and glucocorticoid-sensitive kinase isoforms SGK1, SGK2 and SGK3, and protein kinase B. SGK1 regulates Nedd4-2, a ubiquitin ligase that prepares cell membrane proteins for degradation. To test whether Nedd4-2, SGK1, SGK3 and protein kinase B regulate EAAT1, cRNA encoding EAAT1 was injected into Xenopus oocytes with or without additional injection of wild-type Nedd4-2, constitutively active S422DSGK1, inactive K127NSGK1, wild-type SGK3 and/or constitutively active T308D,S473DPKB. Glutamate induces a current in Xenopus oocytes expressing EAAT1, but not in water-injected oocytes, which is decreased by co-expression of Nedd4-2, an effect reversed by additional co-expression of S422DSGK1, SGK3 and T308D,S473DPKB, but not K127NSGK1. Site-directed mutagenesis of the SGK1 phosphorylation sites in the Nedd4-2 protein (S382A,S468ANedd4-2) and in the EAAT1 protein (T482AEAAT1, T482DEAAT1) significantly blunts the effect of S422DSGK1. Moreover, the current is significantly larger in T482DEAAT1- than in T482AEAAT1-expressing oocytes, indicating that a negative charge mimicking phosphorylation at T482 increases transport. The experiments reveal a powerful novel mechanism that regulates the activity of EAAT1. This mechanism might participate in the regulation of neuronal excitability and glutamate transport in other tissues.
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Affiliation(s)
- Christoph Boehmer
- Department of Physiology I, University of Tübingen, Gmelinstrasse 5, D-72076 Tübingen, Germany
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31
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Nimura N, Fujiwara T, Watanabe A, Sekine M, Furuchi T, Yohda M, Yamagishi A, Oshima T, Homma H. A novel chiral thiol reagent for automated precolumn derivatization and high-performance liquid chromatographic enantioseparation of amino acids and its application to the aspartate racemase assay. Anal Biochem 2003; 315:262-9. [PMID: 12689836 DOI: 10.1016/s0003-2697(02)00705-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A novel optically active thiol compound, N-(tert-butylthiocarbamoyl)-L-cysteine ethyl ester (BTCC), is synthesized as a chiral derivatization reagent. This compound and o-phthalaldehyde react with amino acid enantiomers to produce fluorescent diastereomers that are readily separable on a reverse-phase column by HPLC. Enantioseparation of acidic amino acids in particular is markedly improved using BTCC. In this study, the HPLC method for enantioseparation with the novel compound is applied to the aspartate (Asp) racemase assay. Derivatized D-Asp is eluted before the L-Asp derivative. Consequently, a small amount of D-Asp produced by the activity of racemase on a large quantity of L-Asp substrate may be quantified accurately, even at very low activity. Since the derivatization reaction proceeds rapidly at room temperature, a fully automated system is established for derivatization and sample injection. The automated method is practical and successfully applied to the archaeal Asp racemase assay. We presume that the procedure is additionally applicable to the enantioseparation of other amino acids, amino alcohols, and catecholamines.
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Affiliation(s)
- Noriyuki Nimura
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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32
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Imai K. Analytical Chemical Studies on High-Performance Recognition and Detection of Bio-molecules in Life. YAKUGAKU ZASSHI 2003; 123:901-17. [PMID: 14631753 DOI: 10.1248/yakushi.123.901] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In order to understand the mechanism for maintaining life of animals based on the search of dynamics of biomolecules, I have developed several sensitive and selective methods for their quantification. Using the methods of derivatization with the developed benzofurazan fluorogenic reagents (4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), ammonium 7-fluoro-2,1,3-benzoxadiazole 4-sulfonate (SBD-F) and etc.) followed by high-performance liquid chromatography (HPLC)--fluorescence detection, a certain kind of biological and clinical importance was demonstrated of chiral bio-molecules (D-amino acids, D-lactic acid and so on), peptides and proteins. The proposed method (derivatization with SBD-F, isolation of the fluorescent proteins by two-dimensional HPLC, enzymatic digestion and identification of the altered proteins by HPLC-mass spectrometry (MS)/MS with database-searching algorithm) for proteomics studies revealed the changed proteins in the islets of Langerhans of the dexamethazone-induced diabetic rats. An importance of catecholamine metabolism on the blood pressure regulation was also suggested by the method of HPLC-chemiluminescence detection of catecholamines and their 3-O-methylmetabolites. A new field of Analytical Chemistry, i.e., Bio-Analytical Chemistry, was also proposed.
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Affiliation(s)
- Kazuhiro Imai
- Center for Research and Development, Kyoritsu College of Pharmacy, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan.
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Hamase K, Morikawa A, Zaitsu K. D-Amino acids in mammals and their diagnostic value. J Chromatogr B Analyt Technol Biomed Life Sci 2002; 781:73-91. [PMID: 12450654 DOI: 10.1016/s1570-0232(02)00690-6] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Substantial amounts of D-amino acids are present in mammalian tissues; their function, origin and relationship between pathophysiological processes have been of great interest over the last two decades. In the present article, analytical methods including chromatographic, electrophoretic and enzymatic methods to determine D-amino acids in mammalian tissues are reviewed, and the distribution of these D-amino acids in mammals is discussed. An overview of the function, origin and relationship between the amino acids and pathophysiological processes is also given.
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Affiliation(s)
- Kenji Hamase
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Sekine M, Fukuda H, Nimura N, Furuchi T, Homma H. Automated column-switching high-performance liquid chromatography system for quantifying N-methyl-D- and -L-aspartate. Anal Biochem 2002; 310:114-21. [PMID: 12413481 DOI: 10.1016/s0003-2697(02)00315-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The occurrence and biological significance of the D-amino acids, N-methyl-D-aspartate (NMDA) and N-methyl-L-aspartate (NMLA), have been recently studied in a variety of living organisms. In this study, we established a highly sensitive and reliable fluorometric HPLC system for determining levels of N-methyl-aspartate (NMA). The system comprises fluorescent derivatization of NMA with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and two chromatographic steps: one that separates NMA from other primary amino acids in reverse-phase mode and another that enantioseparates NMDA and NMLA in a normal-phase mode. These two steps are linked by an automated column-switching system. A simple pretreatment step with o-phthalaldehyde to remove primary amino acids that can interfere with sensitivity is also described. The detection limit for NMDA is as low as 5fmol and the correlation between peak heights and concentrations between 5fmol and 1pmol is satisfactory (r=0.999). Following sample preparation and separation using the column-switching HPLC system, more than 80% of NMDA was recovered from rat liver homogenates spiked with NMDA. This method was employed to determine the levels of NMDA in tissues from bivalves and the results obtained were consistent with the values reported previously.
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Affiliation(s)
- Masae Sekine
- Kitasato University, School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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Long Z, Sekine M, Adachi M, Furuchi T, Imai K, Nimura N, Homma H. Cell density inversely regulates D- and L-aspartate levels in rat pheochromocytoma MPT1 cells. Arch Biochem Biophys 2002; 404:92-7. [PMID: 12127073 DOI: 10.1016/s0003-9861(02)00241-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In a previous report (FEBS Lett. 434 (1998) 231), we demonstrated for the first time that D-aspartate (D-Asp) is synthesized in rat pheochromocytoma 12 (PC12) cells. This unique amino acid is believed to act as a novel messenger in mammalian cell regulation. However, the dynamics of D-Asp homeostasis in mammalian cells is yet to be elucidated. In this communication, we demonstrate that D-Asp is also synthesized in MPT1 cells (a subclone of PC12 cells) and that the D- and L-Asp levels in cells are regulated by cell density of the culture. Our data show that D-Asp levels increase, while in contrast, L-Asp levels decrease as a function of increased cell density. Conversely, in PC12 cells, which do not express the glutamate transporter involved in the incorporation of D- and L-Asp into cells, L-Asp levels decrease upon cell density increase while D-Asp concentrations remain almost unchanged. The results indicate that the biochemical behaviors of D- and L-Asp in mammalian cells are distinct and that the cellular levels of these stereoisomers appear to be under different control mechanisms.
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Affiliation(s)
- Zhiqun Long
- School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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