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Xin JX, Wei DX, Ren Y, Wang JL, Yang G, Zhang H, Li J, Fu C, Yao YF. Distinguishing glutamate and glutamine in in vivo 1 H MRS based on nuclear spin singlet order filtering. Magn Reson Med 2023; 89:1728-1740. [PMID: 36572961 DOI: 10.1002/mrm.29562] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 12/28/2022]
Abstract
PURPOSE The signals of glutamate (Glu) and glutamine (Gln) are often significantly overlapped in routine 1 H-MR spectra of human brain in vivo. Selectively probing the signals of Glu and Gln in vivo is very important for the study of the metabolisms in which Glu and Gln are involved. METHODS The Glu-/Gln- targeted pulse sequences are developed to selectively probe the signals of Glu and Gln. The core part of the Glu-/Gln- targeted pulse sequences lies on the preparation of the nuclear spin singlet orders (SSOs) of the five-spin systems of Glu and Gln. The optimal control method is used to prepare the SSOs of Glu and Gln with high efficiency. RESULTS The Glu-/Gln- targeted pulse sequences have been applied on phantoms to selectively probe the signals of Glu and Gln. Moreover, in the in vivo experiments, the signals of Glu and Gln in human brains of healthy subjects have been successfully probed separately. CONCLUSION The developed Glu-/Gln- targeted pulse sequences can be used to distinguish the 1 H-MR signals of Glu and Gln in human brains in vivo. The optimal control method provides an effective way to prepare the SSO of a specific spin system with high efficiency and in turn selectively probe the signals of a targeted molecule.
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Affiliation(s)
- Jia-Xiang Xin
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
| | - Da-Xiu Wei
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
| | - Yan Ren
- Department of Radiology, Huashan Hospital of Fudan University, Shanghai, China
| | - Jun-Long Wang
- Department of Radiology, Huashan Hospital of Fudan University, Shanghai, China
| | - Guang Yang
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
| | - Huojun Zhang
- Department of Radiation Oncology, Shanghai Changhai Hospital, The Second Military Medical University, Shanghai, China
| | - Jianqi Li
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
| | - Caixia Fu
- Application Developments, Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China
| | - Ye-Feng Yao
- Physics Department & Shanghai Key Laboratory of Magnetic Resonance, School of Physics and Electronic Science, East China Normal University, Shanghai, China
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Chang CH, Chen KC, Liaw KC, Peng CC, Peng RY. Astaxanthin Protects PC12 Cells against Homocysteine- and Glutamate-Induced Neurotoxicity. Molecules 2020; 25:E214. [PMID: 31948056 DOI: 10.3390/molecules25010214] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/05/2019] [Accepted: 12/11/2019] [Indexed: 12/15/2022] Open
Abstract
Memory impairment has been shown to be associated with glutamate (Glu) excitotoxicity, homocysteine (Hcy) accumulation, and oxidative stress. We hypothesize that Glu and Hcy could damage neuronal cells, while astaxanthin (ATX) could be beneficial to alleviate the adverse effects. Using PC12 cell model, we showed that Glu and Hcy provoked a huge amount of reactive oxygen species (ROS) production, causing mitochondrial damage at EC50 20 and 10 mm, respectively. The mechanisms of action include: (1) increasing calcium influx; (2) producing ROS; (3) initiating lipid peroxidation; (4) causing imbalance of the Bcl-2/Bax homeostasis; and (5) activating cascade of caspases involving caspases 12 and 3. Conclusively, the damages caused by Glu and Hcy to PC12 cells can be alleviated by the potent antioxidant ATX.
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Mao Y, Zhuang Z, Chen Y, Zhang X, Shen Y, Lin G, Wu R. Imaging of glutamate in acute traumatic brain injury using chemical exchange saturation transfer. Quant Imaging Med Surg 2019; 9:1652-1663. [PMID: 31728309 DOI: 10.21037/qims.2019.09.08] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Background Chemical exchange saturation transfer (CEST) is an important contrast mechanism in the field of magnetic resonance imaging. Herein, we used CEST for glutamate (GluCEST) imaging to evaluate the Glu alterations in acute mild to moderate traumatic brain injury (TBI) and correlated such alterations with the cognitive outcome at 1-month postinjury. Methods Thirty-two patients with well-documented mild-to-moderate TBI and 15 healthy controls (HC group) underwent 3.0-Tesla magnetic resonance imaging (MRI) with GluCEST, and magnetic resonance spectroscopy (MRS) scans. The Montreal Cognitive Assessment (MoCA) examination was administered to all study subjects at 1-month postinjury for cognitive outcome acquisition and divided TBI patients into patients with good cognitive outcome (GCO group) and with poor cognitive outcome (PCO group). Results The GluCEST% values for the occipital gray matter (OGM) and bilateral parietooccipital white matter (PWM) were higher in the PCO group compared with the HC and GCO groups (P<0.05), whereas the GluCEST% value showed no significant differences between the GCO and HC groups (P>0.05). In comparison with HCs, TBI patients had a significantly increased GluCEST% value for the OGM and bilateral PWM (P<0.05). GluCEST performed better than MRS in the prediction of cognitive outcome for TBI patients (P<0.05). Conclusions Glu is significantly increased in acute TBI and strongly correlates with the cognitive outcome at 1month postinjury. GluCEST may supply new insight into TBI and help to improve the accuracy of short-term outcome prediction.
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Affiliation(s)
- Yifei Mao
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China.,Department of Radiology, Shenzhen Maternity and Child Healthcare Hospital, Shenzhen 518028, China
| | - Zerui Zhuang
- Department of Neurosurgery, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Yanzi Chen
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Xiaolei Zhang
- Department of Neurosurgery, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Yuanyu Shen
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Guisen Lin
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
| | - Renhua Wu
- Department of Medical Imaging, The Second Affiliated Hospital, Medical College of Shantou University, Shantou 515041, China
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Abstract
Pain is an essential protective mechanism meant to prevent tissue damages in organisms. On the other hand, chronic or persistent pain caused, for example, by inflammation or nerve injury is long lasting and responsible for long-term disability in patients. Therefore, chronic pain and its management represents a major public health problem. Hence, it is critical to better understand chronic pain molecular mechanisms to develop innovative and efficient drugs. Over the past decades, accumulating evidence has demonstrated a pivotal role of glutamate in pain sensation and transmission, supporting glutamate receptors as promising potential targets for pain relieving drug development. Glutamate is the most abundant excitatory neurotransmitter in the brain. Once released into the synapse, glutamate acts through ionotropic glutamate receptors (iGluRs), which are ligand-gated ion channels triggering fast excitatory neurotransmission, and metabotropic glutamate receptors (mGluRs), which are G protein-coupled receptors modulating synaptic transmission. Eight mGluRs subtypes have been identified and are divided into three classes based on their sequence similarities and their pharmacological and biochemical properties. Of note, all mGluR subtypes (except mGlu6 receptor) are expressed within the nociceptive pathways where they modulate pain transmission. This review will address the role of mGluRs in acute and persistent pain processing and emerging pharmacotherapies for pain management.
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Affiliation(s)
- Vanessa Pereira
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, France
| | - Cyril Goudet
- IGF, CNRS, INSERM, Univ. de Montpellier, Montpellier, France
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Abadie C, Lothier J, Boex-Fontvieille E, Carroll A, Tcherkez G. Direct assessment of the metabolic origin of carbon atoms in glutamate from illuminated leaves using 13 C-NMR. New Phytol 2017; 216:1079-1089. [PMID: 28771732 DOI: 10.1111/nph.14719] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 06/25/2017] [Indexed: 05/21/2023]
Abstract
Glutamate (Glu) is the cornerstone of nitrogen assimilation and photorespiration in illuminated leaves. Despite this crucial role, our knowledge of the flux to Glu de novo synthesis is rather limited. Here, we used isotopic labelling with 13 CO2 and 13 C-NMR analyses to examine the labelling pattern and the appearance of multi-labelled species of Glu molecules to trace the origin of C-atoms found in Glu. We also compared this with 13 C-labelling patterns in Ala and Asp, which reflect citrate (and thus Glu) precursors, that is, pyruvate and oxaloacetate. Glu appeared to be less 13 C-labelled than Asp and Ala, showing that the Glu pool was mostly formed by 'old' carbon atoms. There were modest differences in intramolecular 13 C-13 C couplings between Glu C-2 and Asp C-3, showing that oxaloacetate metabolism to Glu biosynthesis did not involve C-atom redistribution by the Krebs cycle. The apparent carbon allocation increased with carbon net photosynthesis. However, when expressed relative to CO2 fixation, it was clearly higher at low CO2 while it did not change in 2% O2 , as compared to standard conditions. We conclude that Glu production from current photosynthetic carbon represents a small flux that is controlled by the gaseous environment, typically upregulated at low CO2 .
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Affiliation(s)
- Cyril Abadie
- Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, 2601, Australia
| | - Jérémy Lothier
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, SFR 4207 QuaSaV, 42 Rue Georges Morel, Beaucouzé, 49071, France
| | - Edouard Boex-Fontvieille
- Laboratoire de Police Scientifique de Lyon, Institut National de Police Scientifique, 31 Avenue Franklin Roosevelt, Écully Cedex, 69134, France
| | - Adam Carroll
- Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, 2601, Australia
| | - Guillaume Tcherkez
- Research School of Biology, College of Medicine, Biology and Environment, Australian National University, Canberra, ACT, 2601, Australia
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Wermter FC, Bock C, Dreher W. Investigating GluCEST and its specificity for pH mapping at low temperatures. NMR Biomed 2015; 28:1507-17. [PMID: 26412088 DOI: 10.1002/nbm.3416] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 08/19/2015] [Accepted: 08/24/2015] [Indexed: 05/17/2023]
Abstract
Chemical exchange saturation transfer (CEST) from glutamate to water (GluCEST) is a powerful tool for mapping glutamate concentration and intracellular pH. GluCEST could also be helpful to understand the physiology of lower aquatic vertebrates and invertebrates. Therefore, this study aimed to investigate the GluCEST effect and the exchange rate ksw from amine protons of glutamate to water in a broad range of temperatures (1-37°C) and pH (5.5-8.0). Z-spectra were measured from glutamate solutions at different pH values and temperatures and analysed by numerically solving the Bloch-McConnell equation. As expected, a strong dependence of the GluCEST effect and the determined ksw values on pH and temperature was observed. In addition, a strong dependence of the GluCEST effect on phosphate buffer concentration was confirmed. The in vitro data show that GluCEST is detectable in the whole temperature range, even at 1°C. An interpolation function for the exchange rate ksw was determined for the considered range of temperatures and pH values, showing a bijective relation between the exchange rate and pH at a given temperature. To investigate the specificity of GluCEST imaging at low temperatures, the CEST effect was investigated for several metabolites relevant for CEST imaging of the brain. As an example, the contribution of GluCEST to the total CEST effect at 3 ppm was estimated for zebrafish (Danio rerio). It is shown that also at lower temperatures glutamate is the major contributor to the total CEST effect, particularly if the experimental parameters are optimized.
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Affiliation(s)
- Felizitas C Wermter
- University of Bremen, Department of Chemistry, in-vivo-MR Group, Bremen, Germany
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Department of Integrative Ecophysiology, Bremerhaven, Germany
| | - Christian Bock
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Department of Integrative Ecophysiology, Bremerhaven, Germany
| | - Wolfgang Dreher
- University of Bremen, Department of Chemistry, in-vivo-MR Group, Bremen, Germany
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