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Afraei S, D’Aniello A, Sedaghat R, Ekhtiari P, Azizi G, Tabrizian N, Magliozzi L, Aghazadeh Z, Mirshafiey A. Therapeutic effects of D-aspartate in a mouse model of multiple sclerosis. J Food Drug Anal 2017; 25:699-708. [PMID: 28911655 PMCID: PMC9328824 DOI: 10.1016/j.jfda.2016.10.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 10/21/2016] [Accepted: 10/30/2016] [Indexed: 11/30/2022] Open
Abstract
Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis. EAE is mainly mediated by adaptive and innate immune responses that leads to an inflammatory demyelization and axonal damage. The aim of the present research was to examine the therapeutic efficacy of D-aspartic acid (D-Asp) on a mouse EAE model. EAE induction was performed in female C57BL/6 mice by myelin 40 oligodendrocyte glycoprotein (35-55) in a complete Freund's adjuvant emulsion, and D-Asp was used to test its efficiency in the reduction of EAE. During the course of study, clinical evaluation was assessed, and on Day 21, post-immunization blood samples were taken from the heart of mice for the evaluation of interleukin 6 and other chemical molecules. The mice were sacrificed, and their brain and cerebellum were removed for histological analysis. Our findings indicated that D-Asp had beneficial effects on EAE by attenuation in the severity and delay in the onset of the disease. Histological analysis showed that treatment with D-Asp can reduce inflammation. Moreover, in D-Asp-treated mice, the serum level of interleukin 6 was significantly lower than that in control animals, whereas the total antioxidant capacity was significantly higher. The data indicates that D-Asp possess neuroprotective property to prevent the onset of the multiple sclerosis.
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Affiliation(s)
- Sanaz Afraei
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran,
Iran
| | - Antimo D’Aniello
- Laboratory of Neurobiology, Zoological Station of Naples “Anton Dohrn”, Villa Comunale, Napoli,
Italy
| | - Reza Sedaghat
- Departments of Anatomy and Pathology, Faculty of Medicine, Shahed University, Tehran,
Iran
| | - Parvin Ekhtiari
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran,
Iran
| | - Gholamreza Azizi
- Imam Hassan Mojtaba Hospital, Alborz University of Medical Sciences, Karaj,
Iran
- Research Centre for Immunodeficiencies, Pediatrics Centre of Excellence, Children's Medical Centre, Tehran University of Medical Sciences, Tehran,
Iran
| | - Nakisa Tabrizian
- Department of Cellular and Molecular Biology, Kish International Campus, University of Tehran, Tehran,
Iran
| | - Laura Magliozzi
- Department of Biology, University of Naples, “Federico II” Via Cinthia, MSA Campus, bldg. 7, Naples,
Italy
| | - Zahra Aghazadeh
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran,
Iran
| | - Abbas Mirshafiey
- Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran,
Iran
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Fontanarosa C, Pane F, Sepe N, Pinto G, Trifuoggi M, Squillace M, Errico F, Usiello A, Pucci P, Amoresano A. Quantitative determination of free D-Asp, L-Asp and N-methyl-D-aspartate in mouse brain tissues by chiral separation and Multiple Reaction Monitoring tandem mass spectrometry. PLoS One 2017; 12:e0179748. [PMID: 28662080 PMCID: PMC5491048 DOI: 10.1371/journal.pone.0179748] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 06/02/2017] [Indexed: 02/02/2023] Open
Abstract
Several studies have suggested that free d-Asp has a crucial role in N-methyl d-Asp receptor-mediated neurotransmission playing very important functions in physiological and pathological processes. This paper describes the development of an analytical procedure for the direct and simultaneous determination of free d-Asp, l-Asp and N-methyl d-Asp in specimens of different mouse brain tissues using chiral LC-MS/MS in Multiple Reaction Monitoring scan mode. After comparing three procedures and different buffers and extraction solvents, a simple preparation procedure was selected the analytes of extraction. The method was validated by analyzing l-Asp, d-Asp and N-methyl d-Asp recovery at different spiked concentrations (50, 100 and 200 pg/μl) yielding satisfactory recoveries (75–110%), and good repeatability. Limits of detection (LOD) resulted to be 0.52 pg/μl for d-Asp, 0.46 pg/μl for l-Asp and 0.54 pg/μl for NMDA, respectively. Limits of quantification (LOQ) were 1.57 pg/μl for d-Asp, 1.41 pg/μl for l-Asp and 1.64 pg/μl for NMDA, respectively. Different concentration levels were used for constructing the calibration curves which showed good linearity. The validated method was then successfully applied to the simultaneous detection of d-Asp, l-Asp and NMDA in mouse brain tissues. The concurrent, sensitive, fast, and reproducible measurement of these metabolites in brain tissues will be useful to correlate the amount of free d-Asp with relevant neurological processes, making the LC-MS/MS MRM method well suited, not only for research work but also for clinical analyses.
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Affiliation(s)
- Carolina Fontanarosa
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
- Istituto Nazionale Biostrutture e Biosistemi, Roma, Italy
| | - Francesca Pane
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
- Istituto Nazionale Biostrutture e Biosistemi, Roma, Italy
| | - Nunzio Sepe
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Gabriella Pinto
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Marco Trifuoggi
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
| | - Marta Squillace
- CEINGE Advanced Biotechnology, University of Naples “Federico II”, Naples, Italy
| | - Francesco Errico
- CEINGE Advanced Biotechnology, University of Naples “Federico II”, Naples, Italy
- Department of Molecular Medicine and Medical Biotechnology, University of Naples “Federico II”, Naples, Italy
| | - Alessandro Usiello
- CEINGE Advanced Biotechnology, University of Naples “Federico II”, Naples, Italy
| | - Piero Pucci
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
- CEINGE Advanced Biotechnology, University of Naples “Federico II”, Naples, Italy
| | - Angela Amoresano
- Department of Chemical Sciences, University of Naples “Federico II”, Naples, Italy
- Istituto Nazionale Biostrutture e Biosistemi, Roma, Italy
- * E-mail:
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53
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Weatherly CA, Du S, Parpia C, Santos PT, Hartman AL, Armstrong DW. d-Amino Acid Levels in Perfused Mouse Brain Tissue and Blood: A Comparative Study. ACS Chem Neurosci 2017; 8:1251-1261. [PMID: 28206740 DOI: 10.1021/acschemneuro.6b00398] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The l-enantiomer is the predominant type of amino acid in all living systems. However, d-amino acids, once thought to be "unnatural", have been found to be indigenous even in mammalian systems and increasingly appear to be functioning in essential biological and neurological roles. Both d- and l-amino acid levels in the hippocampus, cortex, and blood samples from NIH Swiss mice are reported. Perfused brain tissues were analyzed for the first time, thereby eliminating artifacts due to endogenous blood, and decreased the mouse-to-mouse variability in amino acid levels. Total amino acid levels (l- plus d-enantiomers) in brain tissue are up to 10 times higher than in blood. However, all measured d-amino acid levels in brain tissue are typically ∼10 to 2000 times higher than blood levels. There was a 13% reduction in almost all measured d-amino acid levels in the cortex compared to those in the hippocampus. There is an approximate inverse relationship between the prevalence of an amino acid and the percentage of its d-enantiomeric form. Interestingly, glutamic acid, unlike all other amino acids, had no quantifiable level of its d-antipode. The bioneurological reason for the unique and conspicuous absence/removal of this d-amino acid is yet unknown. However, results suggest that d-glutamate metabolism is likely a unidirectional process and not a cycle, as per the l-glutamate/glutamine cycle. The results suggest that there might be unreported d-amino acid racemases in mammalian brains. The regulation and function of specific other d-amino acids are discussed.
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Affiliation(s)
- Choyce A. Weatherly
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Siqi Du
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Curran Parpia
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Polan T. Santos
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
| | - Adam L. Hartman
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- Department of Molecular Microbiology and Immunology, Johns Hopkins Blomberg School of Public Health, Baltimore, Maryland 21205, United States
| | - Daniel W. Armstrong
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
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Do PH, Tran PV, Bahry MA, Yang H, Han G, Tsuchiya A, Asami Y, Furuse M, Chowdhury VS. Oral administration of a medium containing both D-aspartate-producing live bacteria and D-aspartate reduces rectal temperature in chicks. Br Poult Sci 2017; 58:569-577. [DOI: 10.1080/00071668.2017.1335858] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- P. H. Do
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - P. V. Tran
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - M. A. Bahry
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - H. Yang
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - G. Han
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - A. Tsuchiya
- R&D Division, Meiji Co., Ltd., Kanagawa, Japan
| | - Y. Asami
- R&D Division, Meiji Co., Ltd., Kanagawa, Japan
| | - M. Furuse
- Laboratory of Regulation in Metabolism and Behavior, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
| | - V. S. Chowdhury
- Division for Experimental Natural Science, Faculty of Arts and Science, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, Fukuoka, Japan
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55
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Farajkhoda T. An overview on ethical considerations in stem cell research in Iran and ethical recommendations. Int J Reprod Biomed 2017. [DOI: 10.29252/ijrm.15.2.67] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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56
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Roshanzamir F, Safavi SM. The putative effects of D-Aspartic acid on blood testosterone levels: A systematic review. Int J Reprod Biomed 2017. [DOI: 10.29252/ijrm.15.1.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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57
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Koga R, Miyoshi Y, Sato Y, Mita M, Konno R, Lindner W, Hamase K. Enantioselective determination of citrulline and ornithine in the urine of d -amino acid oxidase deficient mice using a two-dimensional high-performance liquid chromatographic system. J Chromatogr A 2016; 1467:312-317. [DOI: 10.1016/j.chroma.2016.07.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/06/2016] [Accepted: 07/19/2016] [Indexed: 12/20/2022]
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Reddy BS, Chary VN, Pavankumar P, Prabhakar S. Characterization of N-methylated amino acids by GC-MS after ethyl chloroformate derivatization. JOURNAL OF MASS SPECTROMETRY : JMS 2016; 51:638-650. [PMID: 28239971 DOI: 10.1002/jms.3788] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 06/06/2023]
Abstract
Methylation is an essential metabolic process in the biological systems, and it is significant for several biological reactions in living organisms. Methylated compounds are known to be involved in most of the bodily functions, and some of them serve as biomarkers. Theoretically, all α-amino acids can be methylated, and it is possible to encounter them in most animal/plant samples. But the analytical data, especially the mass spectral data, are available only for a few of the methylated amino acids. Thus, it is essential to generate mass spectral data and to develop mass spectrometry methods for the identification of all possible methylated amino acids for future metabolomic studies. In this study, all N-methyl and N,N-dimethyl amino acids were synthesized by the methylation of α-amino acids and characterized by a GC-MS method. The methylated amino acids were derivatized with ethyl chloroformate and analyzed by GC-MS under EI and methane/CI conditions. The EI mass spectra of ethyl chloroformate derivatives of N-methyl (1-18) and N,N-dimethyl amino acids (19-35) showed abundant [M-COOC2 H5 ]+ ions. The fragment ions due to loss of C2 H4 , CO2 , (CO2 + C2 H4 ) from [M-COOC2 H5 ]+ were of structure indicative for 1-18. The EI spectra of 19-35 showed less number of fragment ions when compared with those of 1-18. The side chain group (R) caused specific fragment ions characteristic to its structure. The methane/CI spectra of the studied compounds showed [M + H]+ ions to substantiate their molecular weights. The detected EI fragment ions were characteristic of the structure that made easy identification of the studied compounds, including isomeric/isobaric compounds. Fragmentation patterns of the studied compounds (1-35) were confirmed by high-resolution mass spectra data and further substantiated by the data obtained from 13 C2 -labeled glycines and N-ethoxycarbonyl methoxy esters. The method was applied to human plasma samples for the identification of amino acids and methylated amino acids. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- B Sudarshana Reddy
- Academy of Scientific and Innovative Research, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - V Naresh Chary
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - P Pavankumar
- Academy of Scientific and Innovative Research, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
| | - S Prabhakar
- Academy of Scientific and Innovative Research, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
- National Centre for Mass Spectrometry, CSIR-Indian Institute of Chemical Technology, Hyderabad, 500 007, Telangana, India
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Molecular Mechanisms Elicited by d-Aspartate in Leydig Cells and Spermatogonia. Int J Mol Sci 2016; 17:ijms17071127. [PMID: 27428949 PMCID: PMC4964501 DOI: 10.3390/ijms17071127] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/08/2016] [Accepted: 07/08/2016] [Indexed: 12/11/2022] Open
Abstract
A bulk of evidence suggests that d-aspartate (d-Asp) regulates steroidogenesis and spermatogenesis in vertebrate testes. This review article focuses on intracellular signaling mechanisms elicited by d-Asp possibly via binding to the N-methyl-d-aspartate receptor (NMDAR) in both Leydig cells, and spermatogonia. In Leydig cells, the amino acid upregulates androgen production by eliciting the adenylate cyclase-cAMP and/or mitogen-activated protein kinase (MAPK) pathways. d-Asp treatment enhances gene and protein expression of enzymes involved in the steroidogenic cascade. d-Asp also directly affects spermatogonial mitotic activity. In spermatogonial GC-1 cells, d-Asp induces phosphorylation of MAPK and AKT serine-threonine kinase proteins, and stimulates expression of proliferating cell nuclear antigen (PCNA) and aurora kinase B (AURKB). Further stimulation of spermatogonial GC-1 cell proliferation might come from estradiol/estrogen receptor β (ESR2) interaction. d-Asp modulates androgen and estrogen levels as well as the expression of their receptors in the rat epididymis by acting on mRNA levels of Srd5a1 and Cyp19a1 enzymes, hence suggesting involvement in spermatozoa maturation.
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Ito T, Hayashida M, Kobayashi S, Muto N, Hayashi A, Yoshimura T, Mori H. Serine racemase is involved in d-aspartate biosynthesis. J Biochem 2016; 160:345-353. [DOI: 10.1093/jb/mvw043] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 06/08/2016] [Indexed: 02/02/2023] Open
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61
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d-Aspartate drinking solution alleviates pain and cognitive impairment in neuropathic mice. Amino Acids 2016; 48:1553-67. [DOI: 10.1007/s00726-016-2205-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/23/2016] [Indexed: 12/15/2022]
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Santillo A, Falvo S, Chieffi P, Di Fiore MM, Senese R, Chieffi Baccari G. D-Aspartate Induces Proliferative Pathways in Spermatogonial GC-1 Cells. J Cell Physiol 2016; 231:490-5. [PMID: 26189884 DOI: 10.1002/jcp.25095] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 07/17/2015] [Indexed: 01/10/2023]
Abstract
D-aspartate (D-Asp) is an endogenous amino acid present in vertebrate tissues, with particularly high levels in the testis. In vivo studies indicate that D-Asp indirectly stimulates spermatogenesis through the hypothalamic-pituitary-gonadal axis. Moreover, in vitro studies have demonstrated that D-Asp up-regulates testosterone production in Leydig cells by enhancing expression of the steroidogenic acute regulatory protein. In this study, a cell line derived from immortalized type-B mouse spermatogonia retaining markers of mitotic germ cells (GC-1) was employed to explore more direct involvement of D-Asp in spermatogenesis. Activity and protein expression of markers of cell proliferation were determined at intervals during incubation in D-Asp-containing medium. D-Asp induced phosphorylation of ERK and Akt proteins, stimulated expression of PCNA and Aurora B, and enhanced mRNA synthesis and protein expression of P450 aromatase and protein expression of Estrogen Receptor β (ERβ). These results are the first demonstration of a direct effect of D-Asp on spermatogonial mitotic activity. Considering that spermatogonia express the NR1 subunit of the N-Methyl-D-Aspartic Acid receptor (NMDAR), we suggest that their response to D-Asp depends on NMDAR-mediated activation of the ERK and Akt pathways and is further enhanced by activation of the P450 aromatase/ERβ pathway.
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Affiliation(s)
- Alessandra Santillo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Caserta, Italy
| | - Sara Falvo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Caserta, Italy
| | - Paolo Chieffi
- Dipartimento di Psicologia, Seconda Università di Napoli, Caserta, Italy
| | - Maria Maddalena Di Fiore
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Caserta, Italy
| | - Rosalba Senese
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Caserta, Italy
| | - Gabriella Chieffi Baccari
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Caserta, Italy
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Krashia P, Ledonne A, Nobili A, Cordella A, Errico F, Usiello A, D'Amelio M, Mercuri NB, Guatteo E, Carunchio I. Persistent elevation of D-Aspartate enhances NMDA receptor-mediated responses in mouse substantia nigra pars compacta dopamine neurons. Neuropharmacology 2016; 103:69-78. [DOI: 10.1016/j.neuropharm.2015.12.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 12/11/2015] [Accepted: 12/14/2015] [Indexed: 01/06/2023]
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64
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Di Nisio A, De Toni L, Ferigo M, Rocca MS, Speltra E, Ferlin A, Foresta C. D-Aspartic acid stimulates steroidogenesis through the delay of LH receptor internalization in a mammalian Leydig cell line. J Endocrinol Invest 2016; 39:207-13. [PMID: 26122485 DOI: 10.1007/s40618-015-0333-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/06/2015] [Indexed: 11/25/2022]
Abstract
PURPOSE Recent experimental evidence on non-mammalian animal models showed that D-Aspartic acid (d-Asp) administration increases testosterone levels through upregulation of StAR in Leydig cells. In this study, we aimed to investigate in vitro the signaling pathway associated with d-Asp stimulation in MA-10 murine Leydig cells. METHODS MA-10 cells were stimulated with different concentrations of d-Asp, in presence or absence of hCG. Then total testosterone (T) levels in the culture medium were evaluated by electrochemiluminescence immunoassay, and StAR and LHR protein expressions were quantified by the means of Western blotting. LHR cellular localization after hormonal stimulation was assessed by immunofluorescence. RESULTS Stimulation with the sole d-Asp did not induce any relevant increase of T release from cultured cells. On the other hand, stimulation with hCG induced significant increase of T (P = 0.045). Concomitant stimulation with hCG and d-Asp, at the concentration of 0.1 and 1 nM, induced additional and significant increase of released T (P = 0.03 and P = 0.04, respectively). StAR protein levels increased after concomitant stimulation with hCG and d-Asp 0.1 nM, compared with stimulation with the sole hCG (P = 0.02), whereas no variation in LHR protein expression was observed. Finally, d-Asp attenuated displacement of LHR staining, from cell membrane to cytoplasm, subsequent to hCG stimulation. CONCLUSIONS In this study, we confirmed a steroidogenic role for d-Asp, in concert with hCG, on murine Leydig cells, which is mediated by an increase in StAR protein levels. In addition, we showed that the possible mechanism subtending the effect of d-Asp could rely on the modulation of LHR exposure on the cell membrane.
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Affiliation(s)
- A Di Nisio
- Department of Medicine, Section of Endocrinology and Centre for Human Reproduction Pathology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - L De Toni
- Department of Medicine, Section of Endocrinology and Centre for Human Reproduction Pathology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - M Ferigo
- Department of Molecular Medicine, University of Padova, Padua, Italy
| | - M S Rocca
- Department of Medicine, Section of Endocrinology and Centre for Human Reproduction Pathology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - E Speltra
- Department of Medicine, Section of Endocrinology and Centre for Human Reproduction Pathology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - A Ferlin
- Department of Medicine, Section of Endocrinology and Centre for Human Reproduction Pathology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy
| | - C Foresta
- Department of Medicine, Section of Endocrinology and Centre for Human Reproduction Pathology, University of Padova, Via Giustiniani, 2, 35128, Padua, Italy.
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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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66
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Kiriyama Y, Nochi H. D-Amino Acids in the Nervous and Endocrine Systems. SCIENTIFICA 2016; 2016:6494621. [PMID: 28053803 PMCID: PMC5178360 DOI: 10.1155/2016/6494621] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/14/2016] [Indexed: 05/12/2023]
Abstract
Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA) receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. H2S generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS), such as Alzheimer's disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-amino acids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-amino acids in the nervous and endocrine systems.
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Affiliation(s)
- Yoshimitsu Kiriyama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki, Kagawa 769-2193, Japan
| | - Hiromi Nochi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Shido 1314-1, Sanuki, Kagawa 769-2193, Japan
- *Hiromi Nochi:
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Falvo S, Di Fiore MM, Burrone L, Baccari GC, Longobardi S, Santillo A. Androgen and oestrogen modulation by D-aspartate in rat epididymis. Reprod Fertil Dev 2016; 28:1865-1872. [DOI: 10.1071/rd15092] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 05/05/2015] [Indexed: 11/23/2022] Open
Abstract
Testosterone (T) synthesised in Leydig cells enters the epididymis and may there be converted into dihydrotestosterone (DHT) by 5α-reductase (5α-red) or into 17β-oestradiol (E2) by P450 aromatase (P450-aro). D-aspartate (D-Asp) is known to induce T synthesis in the testis. In this study, we investigated the effects of in vivo D-Asp administration in two major regions of the rat epididymis (Region I: initial segment, caput, corpus; Region II: cauda). The results suggest that exogenous D-Asp was taken up by both regions of rat epididymis. D-Asp administration induced a rapid increase in T, followed by a more gradual decrease in the T : DHT ratio in Region I. In Region II, T levels rapidly decreased and the T : DHT ratio was consistently lower relative to the control. Expression of 5α-red and androgen receptor genes showed a good correlation with DHT levels in both regions. D-Asp treatment also induced an increase of both E2 levels and oestradiol receptor-α (ERα) expression in Region I, whereas neither E2 levels nor ERα expression were affected in Region II. The early increase of P450-aro expression in Region I and late increase in Region II suggests a direct involvement of D-Asp modulation in P450-aro gene expression. Our results suggest that D-Asp modulates androgen and oestrogen levels and expression of androgen and oestrogen receptors in the rat epididymis by acting on the expression of 5α-red and P450-aro genes.
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Cai B, Chen H, Sun H, Sun H, Wan P, Chen D, Pan J. Lactogenic Activity of an Enzymatic Hydrolysate from Octopus vulgaris and Carica papaya in SD Rats. J Med Food 2015; 18:1262-9. [DOI: 10.1089/jmf.2014.3355] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Bingna Cai
- Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Meteria Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Hua Chen
- Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Meteria Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Han Sun
- Rutgers University, New Jersey, USA
| | - Huili Sun
- Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Meteria Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Peng Wan
- Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Meteria Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Deke Chen
- Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Meteria Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Jianyu Pan
- Key Laboratory of Tropical Marine Bio-resources and Ecology/Guangdong Key Laboratory of Marine Meteria Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
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Melville GW, Siegler JC, Marshall PW. Three and six grams supplementation of d-aspartic acid in resistance trained men. J Int Soc Sports Nutr 2015; 12:15. [PMID: 25844073 PMCID: PMC4384294 DOI: 10.1186/s12970-015-0078-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/05/2015] [Indexed: 12/02/2022] Open
Abstract
Background Although abundant research has investigated the hormonal effects of d-aspartic acid in rat models, to date there is limited research on humans. Previous research has demonstrated increased total testosterone levels in sedentary men and no significant changes in hormonal levels in resistance trained men. It was hypothesised that a higher dosage may be required for experienced lifters, thus this study investigated the effects of two different dosages of d-aspartic acid on basal hormonal levels in resistance trained men and explored responsiveness to d-aspartic acid based on initial testosterone levels. Methods Twenty-four males, with a minimum of two years’ experience in resistance training, (age, 24.5 ± 3.2 y; training experience, 3.4 ± 1.4 y; height, 178.5 ± 6.5 cm; weight, 84.7 ± 7.2 kg; bench press 1-RM, 105.3 ± 15.2 kg) were randomised into one of three groups: 6 g.d−1 plain flour (D0); 3 g.d−1 of d-aspartic acid (D3); and 6 g.d−1 of d-aspartic acid (D6). Participants performed a two-week washout period, training four days per week. This continued through the experimental period (14 days), with participants consuming the supplement in the morning. Serum was analysed for levels of testosterone, estradiol, sex hormone binding globulin, albumin and free testosterone was determined by calculation. Results D-aspartic acid supplementation revealed no main effect for group in: estradiol; sex-hormone-binding-globulin; and albumin. Total testosterone was significantly reduced in D6 (P = 0.03). Analysis of free testosterone showed that D6 was significantly reduced as compared to D0 (P = 0.005), but not significantly different to D3. Analysis did not reveal any significant differences between D3 and D0. No significant correlation between initial total testosterone levels and responsiveness to d-aspartic acid was observed (r = 0.10, P = 0.70). Conclusions The present study demonstrated that a daily dose of six grams of d-aspartic acid decreased levels of total testosterone and free testosterone (D6), without any concurrent change in other hormones measured. Three grams of d-aspartic acid had no significant effect on either testosterone markers. It is currently unknown what effect this reduction in testosterone will have on strength and hypertrophy gains.
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Affiliation(s)
- Geoffrey W Melville
- School of Science & Health, University of Western Sydney, Campbelltown Campus, Locked Bag 1797, Penrith, NSW 2751 Australia
| | - Jason C Siegler
- School of Science & Health, University of Western Sydney, Campbelltown Campus, Locked Bag 1797, Penrith, NSW 2751 Australia
| | - Paul Wm Marshall
- School of Science & Health, University of Western Sydney, Campbelltown Campus, Locked Bag 1797, Penrith, NSW 2751 Australia
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Is D-aspartate produced by glutamic-oxaloacetic transaminase-1 like 1 (Got1l1): a putative aspartate racemase? Amino Acids 2014; 47:79-86. [PMID: 25287256 PMCID: PMC4282708 DOI: 10.1007/s00726-014-1847-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/25/2014] [Indexed: 12/23/2022]
Abstract
D-Aspartate is an endogenous free amino acid in the brain, endocrine tissues, and exocrine tissues in mammals, and it plays several physiological roles. In the testis, D-aspartate is detected in elongate spermatids, Leydig cells, and Sertoli cells, and implicated in the synthesis and release of testosterone. In the hippocampus, D-aspartate strongly enhances N-methyl-D-aspartate receptor-dependent long-term potentiation and is involved in learning and memory. The existence of aspartate racemase, a candidate enzyme for D-aspartate production, has been suggested. Recently, mouse glutamic-oxaloacetic transaminase 1-like 1 (Got1l1) has been reported to synthesize substantially D-aspartate from L-aspartate and to be involved in adult neurogenesis. In this study, we investigated the function of Got1l1 in vivo by generating and analyzing Got1l1 knockout (KO) mice. We also examined the enzymatic activity of recombinant Got1l1 in vitro. We found that Got1l1 mRNA is highly expressed in the testis, but it is not detected in the brain and submandibular gland, where D-aspartate is abundant. The D-aspartate contents of wild-type and Got1l1 KO mice were not significantly different in the testis and hippocampus. The recombinant Got1l1 expressed in mammalian cells showed L-aspartate aminotransferase activity, but lacked aspartate racemase activity. These findings suggest that Got1l1 is not the major aspartate racemase and there might be an as yet unknown D-aspartate-synthesizing enzyme.
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Raucci F, D'Aniello A, Di Fiore MM. Stimulation of androgen production by D-aspartate through the enhancement of StAR, P450scc and 3β-HSD mRNA levels in vivo rat testis and in culture of immature rat Leydig cells. Steroids 2014; 84:103-10. [PMID: 24713504 DOI: 10.1016/j.steroids.2014.03.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 03/18/2014] [Accepted: 03/25/2014] [Indexed: 11/23/2022]
Abstract
Previous studies have shown a role of d-aspartic acid (d-Asp) in testicular steroidogenesis. Here, we evaluated the effects of d-Asp on androgen production and on expression levels of mRNAs encoding specific steroidogenic key molecules. d-Asp was endogenously present in adult rat testis and its content paralleled to serum luteinizing hormone (LH) and, local and circulating androstenedione and testosterone levels. In vivod-Asp administration induced serum LH release, causing an indirect increase of androstenedione and testosterone levels by enhancing steroidogenic acute regulatory protein (StAR), cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) and 3β-hydroxysteroid dehydrogenase/D5-D4 isomerases (3β-HSD) mRNA levels. The direct endocrine role of d-Asp was evaluated using cultured immature Leydig cells (ILCs) obtained from 35days old rats. Cytoplasm and nucleus of ILCs localized d-Asp, while StAR marked the cytoplasm only. After 12h from d-Asp in vitro administration, ILCs resulted intensely d-Asp stained, and StaR protein level, evaluated by Western blotting, significantly increased. After 24h, significant androstenedione and testosterone syntheses were induced. At molecular level, d-Asp administration significantly increased StAR, P450scc and 3β-HSD mRNAs at 2, 4 and 12h, respectively. The temporal shift on relative mRNA expression levels indicated that d-Asp exerted its physiological role through sequential gene cascade activation of those molecules implicated in the synthesis of androgens. Conclusively, our findings demonstrated that d-Asp is a local messenger in testis and give a contribution in understanding the complexity of local endocrine regulation as well as the molecular events leading the acquisition to a steroidogenic competence by ILCs.
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Affiliation(s)
- Franca Raucci
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100 Caserta, Italy.
| | - Antimo D'Aniello
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100 Caserta, Italy
| | - Maria Maddalena Di Fiore
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Seconda Università di Napoli, Via Vivaldi 43, 81100 Caserta, Italy
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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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73
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Santillo A, Falvo S, Chieffi P, Burrone L, Chieffi Baccari G, Longobardi S, Di Fiore MM. d-aspartate affects NMDA receptor-extracellular signal–regulated kinase pathway and upregulates androgen receptor expression in the rat testis. Theriogenology 2014; 81:744-51. [DOI: 10.1016/j.theriogenology.2013.12.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 11/28/2013] [Accepted: 12/09/2013] [Indexed: 10/25/2022]
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Errico F, Napolitano F, Squillace M, Vitucci D, Blasi G, de Bartolomeis A, Bertolino A, D'Aniello A, Usiello A. Decreased levels of D-aspartate and NMDA in the prefrontal cortex and striatum of patients with schizophrenia. J Psychiatr Res 2013; 47:1432-7. [PMID: 23835041 DOI: 10.1016/j.jpsychires.2013.06.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 06/10/2013] [Accepted: 06/18/2013] [Indexed: 01/24/2023]
Abstract
The potential implication of a decrease in the function of N-methyl-d-aspartate receptors (NMDARs) in the pathophysiology of schizophrenia has long been hypothesised. Accordingly, compounds that inhibit the glycine-1 transporter or target the glycine-binding site of NMDARs, including the co-agonists D-serine and glycine, have shown promise in treating the symptoms of schizophrenia. Clinical interest for d-serine has also been supported by evidence for its abnormal metabolism in schizophrenic patients. Together with D-serine, another D-form amino acid, D-aspartate, exists in the brain of mammals. Synthesised by the enzyme aspartate racemase, D-aspartate is highly concentrated in the prenatal brain; after birth, its levels sharply decrease due to the catabolising activity of the enzyme D-aspartate oxidase. D-aspartate is able to stimulate NMDAR-dependent neurotransmission through direct action at the glutamate-binding site of NMDARs, thus functioning as an endogenous agonist for this subclass of glutamate receptors. In this study, we evaluated for the first time the content of D-aspartate and of its derivative, NMDA, in the post-mortem prefrontal cortex and striatum of schizophrenic patients. Moreover, in the same brain samples, we analysed the expression levels of the subunits that form NMDARs, which are the in vivo targets of D-aspartate and NMDA. Interestingly, we found that D-aspartate and NMDA are consistently decreased in schizophrenia brains compared to control brains. In the prefrontal cortex, this decrease is correlated with a marked downregulation of NMDAR subunits. Overall, these results agree with the innovative therapeutic research in schizophrenia that is aimed at targeting glutamatergic transmission via D-amino acids.
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d-Aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained men. Nutr Res 2013; 33:803-10. [DOI: 10.1016/j.nutres.2013.07.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/11/2013] [Accepted: 07/13/2013] [Indexed: 11/23/2022]
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76
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Two-dimensional high-performance liquid chromatographic determination of day–night variation of d-alanine in mammals and factors controlling the circadian changes. Anal Bioanal Chem 2013; 405:8083-91. [DOI: 10.1007/s00216-013-7071-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/04/2013] [Accepted: 05/16/2013] [Indexed: 11/29/2022]
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77
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Raucci F, Di Fiore MM. The maturation of oocyte follicular epithelium of Podarcis s. sicula is promoted by D-aspartic acid. J Histochem Cytochem 2013; 58:157-71. [PMID: 19826072 DOI: 10.1369/jhc.2009.954636] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 09/25/2009] [Indexed: 11/22/2022] Open
Abstract
We investigated whether the maturation of oocyte follicular epithelium of lizard is affected by d-aspartic acid (d-Asp). Our results demonstrated that d-Asp is endogenously present in the oocytes, and its distribution varies during the reproductive cycle and following intraperitoneal administration. At previtellogenesis, it is observed in the cytoplasm and nucleus of pyriform cells, in intermediate cells, in some small cells of the granulosa, in the ooplasm, and in some thecal elements. At vitellogenesis, d-Asp is localized in the proximity of the zona pellucida, in the theca, and in the ooplasm. Injected d-Asp is mainly captured by pyriform cells and ooplasm of previtellogenic oocytes, but a moderate accumulation is evident in the cytoplasm of some small granulosa cells and in the theca. d-Asp also increases the ovarian and plasmatic levels of 17β-estradiol and decreases those of testosterone. As a direct and/or indirect consequence of d-Asp, previtellogenic oocytes grow up and mature, resulting in a higher accumulation of carbohydrates in the granulosa, zona pellucida, and ooplasm, but also a reduction in the thickness of the granulosa layer and an increase of the theca stratum. Taken together, our results show that d-Asp may be related to the synchrony of reproduction, either enhancing the growth and maturation of follicular epithelium or influencing its endocrine functions.
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Affiliation(s)
- Franca Raucci
- Department of Life Sciences, Second University of Naples, Caserta, Italy.
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Oral Administration of D-aspartate, but not of L-aspartate, Reduces Food Intake in Chicks. J Poult Sci 2013. [DOI: 10.2141/jpsa.0120116] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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79
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Enantioselective two-dimensional high-performance liquid chromatographic determination of N-methyl-d-aspartic acid and its analogues in mammals and bivalves. J Chromatogr A 2012; 1269:255-61. [DOI: 10.1016/j.chroma.2012.08.075] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 08/22/2012] [Accepted: 08/24/2012] [Indexed: 12/21/2022]
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Komarova NV, Golubev IV, Khoronenkova SV, Chubar’ TA, Tishkov VI. Engineering of substrate specificity of D-amino acid oxidase from the yeast Trigonopsis variabilis: Directed mutagenesis of Phe258 residue. BIOCHEMISTRY (MOSCOW) 2012; 77:1181-9. [DOI: 10.1134/s0006297912100100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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81
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D-Aspartate acts as a signaling molecule in nervous and neuroendocrine systems. Amino Acids 2012; 43:1873-86. [PMID: 22872108 DOI: 10.1007/s00726-012-1364-1] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/06/2012] [Indexed: 10/28/2022]
Abstract
D-Aspartate (D-Asp) is an endogenous amino acid in the central nervous and reproductive systems of vertebrates and invertebrates. High concentrations of D-Asp are found in distinct anatomical locations, suggesting that it has specific physiological roles in animals. Many of the characteristics of D-Asp have been documented, including its tissue and cellular distribution, formation and degradation, as well as the responses elicited by D-Asp application. D-Asp performs important roles related to nervous system development and hormone regulation; in addition, it appears to act as a cell-to-cell signaling molecule. Recent studies have shown that D-Asp fulfills many, if not all, of the definitions of a classical neurotransmitter-that the molecule's biosynthesis, degradation, uptake, and release take place within the presynaptic neuron, and that it triggers a response in the postsynaptic neuron after its release. Accumulating evidence suggests that these criteria are met by a heterogeneous distribution of enzymes for D-Asp's biosynthesis and degradation, an appropriate uptake mechanism, localization within synaptic vesicles, and a postsynaptic response via an ionotropic receptor. Although D-Asp receptors remain to be characterized, the postsynaptic response of D-Asp has been studied and several L-glutamate receptors are known to respond to D-Asp. In this review, we discuss the current status of research on D-Asp in neuronal and neuroendocrine systems, and highlight results that support D-Asp's role as a signaling molecule.
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Burrone L, Santillo A, Pinelli C, Baccari GC, Di Fiore MM. Induced synthesis of P450 aromatase and 17β-estradiol by D-aspartate in frog brain. ACTA ACUST UNITED AC 2012; 215:3559-65. [PMID: 22771744 DOI: 10.1242/jeb.073296] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
D-Aspartic acid is an endogenous amino acid occurring in the endocrine glands as well as in the nervous system of various animal phyla. Our previous studies have provided evidence that D-aspartate plays a role in the induction of estradiol synthesis in gonads. Recently, we have also demonstrated that D-aspartic acid induces P450 aromatase mRNA expression in the frog (Pelophylax esculentus) testis. P450 aromatase is the key enzyme in the estrogen synthetic pathway and irreversibly converts testosterone into 17β-estradiol. In this study, we firstly investigated the immunolocalisation of P450 aromatase in the brain of P. esculentus, which has never previously been described in amphibians. Therefore, to test the hypothesis that d-aspartate mediates a local synthesis of P450 aromatase in the frog brain, we administered D-aspartate in vivo to male frogs and then assessed brain aromatase expression, sex hormone levels and sex hormone receptor expression. We found that D-aspartate enhances brain aromatase expression (mRNA and protein) through the CREB pathway. Then, P450 aromatase induces 17β-estradiol production from testosterone, with a consequent increase of its receptor. Therefore, the regulation of d-aspartate-mediated P450 aromatase expression could be an important step in the control of neuroendocrine regulation of the reproductive axis. Accordingly, we found that the sites of P450 aromatase immunoreactivity in the frog brain correspond to the areas known to be involved in neurosteroid synthesis.
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Affiliation(s)
- Lavinia Burrone
- Dipartimento di Scienze della Vita, Seconda Università degli Studi di Napoli, Via Vivaldi 43, 81100, Caserta, Italy
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Senda M, Yamamoto A, Tanaka H, Ishida T, Horiike K, Senda T. Crystallization and preliminary crystallographic analysis of D-aspartate oxidase from porcine kidney. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:644-6. [PMID: 22684060 PMCID: PMC3370900 DOI: 10.1107/s1744309112013243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 03/27/2012] [Indexed: 11/10/2022]
Abstract
D-Aspartate oxidase (DDO) from porcine kidney was crystallized by the sitting-drop vapour-diffusion method using PEG 8000 as a precipitant. The crystal belonged to space group P2(1), with unit-cell parameters a = 79.38, b = 144.0, c = 80.46 Å, β = 101.1°, and diffracted to 1.80 Å resolution. Molecular-replacement trials using the structure of human D-amino-acid oxidase, which is 42% identical in sequence to DDO, as a search model provided a satisfactory solution.
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Affiliation(s)
- Miki Senda
- Structure Guided Drug Development Project, JBIC Research Institute, Japan Biological Informatics Consortium, 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan.
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Erwan E, Tomonaga S, Yoshida J, Nagasawa M, Ogino Y, Denbow DM, Furuse M. Central administration of l- and d-aspartate attenuates stress behaviors by social isolation and CRF in neonatal chicks. Amino Acids 2012; 43:1969-76. [DOI: 10.1007/s00726-012-1272-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 03/13/2012] [Indexed: 11/28/2022]
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85
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Nguyen DT, Kim KR, Lee G, Paik MJ. Chiral separation ofN-methyl-dl-aspartic acid in rat brain tissue asN-ethoxycarbonylated (S)-(+)-2-octyl ester derivatives by GC-MS. Biomed Chromatogr 2012; 26:1353-6. [DOI: 10.1002/bmc.2703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 12/16/2011] [Accepted: 12/16/2011] [Indexed: 11/05/2022]
Affiliation(s)
- Duc-Toan Nguyen
- Department of Molecular Science and Technology; Ajou University; Suwon; 443-721; Republic of Korea
| | - Kyoung-Rae Kim
- College of Pharmacy; Sungkyunkwan University; Suwon; 440-746; Republic of Korea
| | | | - Man-Jeong Paik
- Department of Molecular Science and Technology; Ajou University; Suwon; 443-721; Republic of Korea
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Fisher GH, Tsesarskaia M. HPLC methods for determination of D-aspartate and N-methyl-D-aspartate. Methods Mol Biol 2012; 794:253-264. [PMID: 21956568 DOI: 10.1007/978-1-61779-331-8_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
D-Amino acids are stereoisomers or optical isomers of naturally occurring L-amino acids and thus possess the same chemical structure, but may differ in their biological/physiological properties. Until a half century ago, D-amino acids had been considered to be unnatural substances found only in microorganisms. However, improvements in analytical instruments and methods have revealed that D-amino acids are present in invertebrates and vertebrates, including humans, and that they possess important physiological functions. D-Aspartate (D-Asp) and its methylated form N-methyl-D-aspartate (NMDA) possess neuroendocrine properties in many species. Several methods have been developed for determination of D- and L-enantiomers of amino acids by high performance liquid chromatography (HPLC). We report here improved HPLC methods for the specific determination of D-Asp and NMDA in biological tissues.
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Affiliation(s)
- George H Fisher
- Department of Chemistry, Barry University, Miami Shores, FL, USA.
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Burrone L, Raucci F, Di Fiore MM. Steroidogenic gene expression following D-aspartate treatment in frog testis. Gen Comp Endocrinol 2012; 175:109-17. [PMID: 22036840 DOI: 10.1016/j.ygcen.2011.10.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 10/09/2011] [Accepted: 10/11/2011] [Indexed: 11/30/2022]
Abstract
Previous studies have provided evidence that D-Asp plays a role in steroid-mediated reproductive biology in amphibians, reptiles, birds and mammals. To examine the molecular involvement of D-Asp on steroidogenic pathway regulation, we analysed the expression of StAR, P450 aromatase and 5αRed2 mRNAs in Pelophylax esculentus testis, either in relation to the reproductive cycle or D-Asp treatment. Basal StAR mRNA levels, as well as D-Asp and testosterone concentrations, were higher in reproductive than in post-reproductive frogs. D-Asp treatment increased StAR mRNA expression and immunolocalisation in both the reproductive and post-reproductive periods. In control testis, aromatase mRNA levels were higher in the post-reproductive period, but following D-Asp administration, they increased only in the reproductive period. The level of 5αRed2 mRNA was higher in reproductive frogs than in post-reproductive frogs, and it increased after D-Asp treatment only in the post-reproductive phase. Our results suggest that, in P. esculentus testis, D-Asp increases StAR mRNA in both periods, and P450 aromatase and 5αRed2 mRNAs at different points during the reproductive cycle.
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Affiliation(s)
- Lavinia Burrone
- Dipartimento di Scienze della Vita, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy
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88
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Errico F, Nisticò R, Napolitano F, Mazzola C, Astone D, Pisapia T, Giustizieri M, D’Aniello A, Mercuri NB, Usiello A. Increased d-aspartate brain content rescues hippocampal age-related synaptic plasticity deterioration of mice. Neurobiol Aging 2011; 32:2229-43. [DOI: 10.1016/j.neurobiolaging.2010.01.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 01/04/2010] [Accepted: 01/07/2010] [Indexed: 12/31/2022]
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89
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Errico F, Nisticò R, Napolitano F, Oliva AB, Romano R, Barbieri F, Florio T, Russo C, Mercuri NB, Usiello A. Persistent increase of d-aspartate in d-aspartate oxidase mutant mice induces a precocious hippocampal age-dependent synaptic plasticity and spatial memory decay. Neurobiol Aging 2011; 32:2061-74. [DOI: 10.1016/j.neurobiolaging.2009.12.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 10/20/2009] [Accepted: 12/08/2009] [Indexed: 11/29/2022]
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90
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Effect of d-aspartate uptake on uncoupling protein-3 and α-tubulin expressions in rat Harderian gland. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3344-8. [DOI: 10.1016/j.jchromb.2011.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 03/23/2011] [Accepted: 04/01/2011] [Indexed: 11/18/2022]
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91
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Shibata K, Sugaya N, Ono W, Abe K, Takahashi S, Kera Y. Determination of d-aspartate N-methyltransferase activity in the starfish by direct analysis of N-methyl-d-aspartate with high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3229-34. [DOI: 10.1016/j.jchromb.2011.02.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Revised: 02/16/2011] [Accepted: 02/22/2011] [Indexed: 11/25/2022]
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92
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Han H, Miyoshi Y, Oyama T, Konishi R, Mita M, Hamase K. Enantioselective micro-2D-HPLC determination of aspartic acid in the pineal glands of rodents with various melatonin contents. J Sep Sci 2011; 34:2847-53. [DOI: 10.1002/jssc.201100609] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 08/10/2011] [Accepted: 08/11/2011] [Indexed: 12/23/2022]
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93
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Conti P, Tamborini L, Pinto A, Blondel A, Minoprio P, Mozzarelli A, De Micheli C. Drug Discovery Targeting Amino Acid Racemases. Chem Rev 2011; 111:6919-46. [DOI: 10.1021/cr2000702] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Paola Conti
- Dipartimento di Scienze Farmaceutiche “P. Pratesi”, via Mangiagalli 25, 20133 Milano, Italy
| | - Lucia Tamborini
- Dipartimento di Scienze Farmaceutiche “P. Pratesi”, via Mangiagalli 25, 20133 Milano, Italy
| | - Andrea Pinto
- Dipartimento di Scienze Farmaceutiche “P. Pratesi”, via Mangiagalli 25, 20133 Milano, Italy
| | - Arnaud Blondel
- Institut Pasteur, Unité de Bioinformatique Structurale, CNRS-URA 2185, Département de Biologie Structurale et Chimie, 25 rue du Dr. Roux, 75724 Paris, France
| | - Paola Minoprio
- Institut Pasteur, Laboratoire des Processus Infectieux à Trypanosoma; Département d’Infection et Epidémiologie; 25 rue du Dr. Roux, 75724 Paris, France
| | - Andrea Mozzarelli
- Dipartimento di Biochimica e Biologia Molecolare, via G. P. Usberti 23/A, 43100 Parma, Italy
- Istituto di Biostrutture e Biosistemi, viale Medaglie d’oro, Roma, Italy
| | - Carlo De Micheli
- Dipartimento di Scienze Farmaceutiche “P. Pratesi”, via Mangiagalli 25, 20133 Milano, Italy
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94
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Baldassarre M, Scirè A, Tanfani F. Turning pyridoxal-5'-phosphate-dependent enzymes into thermostable binding proteins: D-Serine dehydratase from baker's yeast as a case study. Biochimie 2011; 94:479-86. [PMID: 21896305 DOI: 10.1016/j.biochi.2011.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 08/24/2011] [Indexed: 12/21/2022]
Abstract
D-serine dehydratase from Saccharomyces cerevisae is a recently discovered dimeric enzyme catalyzing the β-elimination of D-serine to pyruvate and ammonia. The reaction is highly enantioselective and depends on cofactor pyridoxal-5'-phosphate (PLP) and Zn(2+). In our work, the aldimine linkage tethering PLP to recombinant, tagged D-serine dehydratase (Dsd) has been reduced by treatment with NaBH(4) so as to yield an inactive form of the holoenzyme (DsdR), which was further treated with a protease in order to remove the amino-terminal purification tag. Fourier Transform infrared (FT-IR) spectroscopic analysis revealed that both the reduced form (DsdR) and the reduced/detagged form (DsdRD) maintain the overall secondary structure of Dsd, but featured a significant increased thermal stability. The observed T(m) values for DsdR and for DsdRD shifted to 71.5 °C and 73.3 °C, respectively, resulting in nearly 11 °C and 13 °C higher than the one measured for Dsd. Furthermore, the analysis of the FT-IR spectra acquired in the presence of D-serine and L-serine indicates that, though catalytically inert, DsdRD retains the ability to enantioselectively bind its natural substrate. Sequence analysis of D-serine dehydratase and other PLP-dependent enzymes also highlighted critical residues involved in PLP binding. In virtue of its intrinsic properties, DsdRD represents an ideal candidate for the design of novel platforms based on stable, non-consuming binding proteins aimed at measuring d-serine levels in biological fluids.
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Affiliation(s)
- Maurizio Baldassarre
- Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Ranieri, 60131 Ancona, Italy
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95
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Chervyakov AV, Gulyaeva NV, Zakharova MN. D-amino acids in normal ageing and pathogenesis of neurodegenerative diseases. NEUROCHEM J+ 2011. [DOI: 10.1134/s1819712411020036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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96
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Raucci F, Di Fiore MM. D-Asp: a new player in reproductive endocrinology of the amphibian Rana esculenta. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:3268-76. [PMID: 21531634 DOI: 10.1016/j.jchromb.2011.04.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 03/24/2011] [Accepted: 04/01/2011] [Indexed: 11/18/2022]
Abstract
We investigated the involvement of D-Aspartic acid (D-Asp) on ovarian and testicular morphology of the green frog, Rana esculenta, and its effect on the testosterone production. The study has been performed throughout the reproductive cycle. In both ovary and testis a substantial amount of D-Asp is endogenously present and its concentration varies as function of reproduction. In the frog, D-Asp content is differently correlated with gonadal and plasmatic levels of testosterone, depending on the sex. In fact, the amount of the D-Asp is inversely linked with that of the testosterone in the ovary, while this correlation directly matched in the testis. In vivo short-term experiments, consisting of a single intra-peritoneal injection of D-Asp (2.0 μmol/g body weight), demonstrated that the enantiomer is significantly accumulated by both the ovary and testis, reaching after 3 h the highest uptake and thereafter decreasing to baseline values within 24 h. Furthermore, D-Asp influences the synthesis and/or the release of testosterone, causing a decrease of its level in the female, and an increase in the male, respectively. In vivo long-term experiments, D-Asp, chronically administered to the frogs of both sexes, enhances the maturation of both gonads, determining in the oocytes an higher accumulation of carbohydrate yolk plates in the ooplasm, and stimulating the spermatogenesis in the testis. Taken altogether, our results show that D-Asp operates differently in female and male frog gonads, indicating that it has different targets in the reproductive machinery depending on the sex.
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Affiliation(s)
- Franca Raucci
- Department of Life Sciences, Second University of Naples (SUN), Via Vivaldi 43, 81100 Caserta, Italy
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97
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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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98
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D'Aniello S, Somorjai I, Garcia-Fernàndez J, Topo E, D'Aniello A. D-Aspartic acid is a novel endogenous neurotransmitter. FASEB J 2010; 25:1014-27. [PMID: 21163862 DOI: 10.1096/fj.10-168492] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
D-aspartic acid (D-Asp) is present in invertebrate and vertebrate neuroendocrine tissues, where it carries out important physiological functions and is implicated in nervous system development. We show here that D-Asp is a novel endogenous neurotransmitter in two distantly related animals, a mammal (Rattus norvegicus) and a mollusk (Loligo vulgaris). Our main findings demonstrate that D-Asp is present in high concentrations in the synaptic vesicles of axon terminals; synthesis for this amino acid occurs in neurons by conversion of L-Asp to D-Asp via D-aspartate racemase; depolarization of nerve endings with K(+) ions evokes an immediate release of D-Asp in a Ca(2+) dependent manner; specific receptors for D-Asp occur at the postsynaptic membrane, as demonstrated by binding assays and by the expansion of squid skin chromatophores; D-aspartate oxidase, the specific enzyme that oxidizes D-Asp, is present in the postsynaptic membranes; and stimulation of nerve endings with D-Asp triggers signal transduction by increasing the second messenger cAMP. Taken together, these data demonstrate that D-Asp fulfills all criteria necessary to be considered a novel endogenous neurotransmitter. Given its known role in neurogenesis, learning, and neuropathologies, our results have important implications for biomedical and clinical research.
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Affiliation(s)
- Salvatore D'Aniello
- Departament de Genètica, Institut de Biomedicina, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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99
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Wang Y, Denisova JV, Kang KS, Fontes JD, Zhu BT, Belousov AB. Neuronal gap junctions are required for NMDA receptor-mediated excitotoxicity: implications in ischemic stroke. J Neurophysiol 2010; 104:3551-6. [PMID: 20943940 PMCID: PMC3007655 DOI: 10.1152/jn.00656.2010] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 10/12/2010] [Indexed: 11/22/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) play an important role in cell survival versus cell death decisions during neuronal development, ischemia, trauma, and epilepsy. Coupling of neurons by electrical synapses (gap junctions) is high or increases in neuronal networks during all these conditions. In the developing CNS, neuronal gap junctions are critical for two different types of NMDAR-dependent cell death. However, whether neuronal gap junctions play a role in NMDAR-dependent neuronal death in the mature CNS was not known. Using Fluoro-Jade B staining, we show that a single intraperitoneal administration of NMDA (100 mg/kg) to adult wild-type mice induces neurodegeneration in three forebrain regions, including rostral dentate gyrus. However, the NMDAR-mediated neuronal death is prevented by pharmacological blockade of neuronal gap junctions (with mefloquine, 30 mg/kg) and does not occur in mice lacking neuronal gap junction protein, connexin 36. Using Western blots, electrophysiology, calcium imaging, and gas chromatography-mass spectrometry in wild-type and connexin 36 knockout mice, we show that the reduced level of neuronal death in knockout animals is not caused by the reduced expression of NMDARs, activity of NMDARs, or permeability of the blood-brain barrier to NMDA. In wild-type animals, this neuronal death is not caused by upregulation of connexin 36 by NMDA. Finally, pharmacological and genetic inactivation of neuronal gap junctions in mice also dramatically reduces neuronal death caused by photothrombotic focal cerebral ischemia. The results indicate that neuronal gap junctions are required for NMDAR-dependent excitotoxicity and play a critical role in ischemic neuronal death.
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Affiliation(s)
- Yongfu Wang
- Dept. of Molecular and Integrative Physiology, Univ. of Kansas Medical Center, 2146 W. 39th Ave., Kansas City, KS 66160, USA
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100
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Scanlan C, Shi T, Hatcher NG, Rubakhin SS, Sweedler JV. Synthesis, accumulation, and release of d-aspartate in the Aplysia californica CNS. J Neurochem 2010; 115:1234-44. [PMID: 20874765 PMCID: PMC2972370 DOI: 10.1111/j.1471-4159.2010.07020.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
d-Aspartate (d-Asp) is an endogenous molecule that is often detected in CNS and endocrine tissues. Using capillary electrophoresis and a variety of radionuclide detection techniques, we examine the synthesis, release, and uptake/accumulation of d-Asp in the CNS of the marine mollusk Aplysia californica. We observe the preferential synthesis and accumulation of d-Asp over l-aspartate (l-Asp) in neuron-containing ganglia compared to surrounding sheath tissues. Little conversion of d-Asp to l-Asp is detected. The Ca(2+) ionophore ionomycin and elevated extracellular potassium stimulates release of d-Asp from the cerebral ganglia. Lastly, radioactive d-Asp in the extracellular media is efficiently taken up and accumulated by individual F-cluster neurons. These observations point to a role for d-Asp in cell-to-cell signaling with many characteristics similar to classical transmitters.
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Affiliation(s)
- Cory Scanlan
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, USA
| | - Ting Shi
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, USA
| | - Nathan G. Hatcher
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, USA
| | - Stanislav S. Rubakhin
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, USA
| | - Jonathan V. Sweedler
- Department of Chemistry and the Beckman Institute, University of Illinois at Urbana-Champaign, USA
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