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Gujar V, Pande RD, Hardas BM, Das S. Nerve Growth Factor Signaling Modulates the Expression of Glutaminase in Dorsal Root Ganglion Neurons during Peripheral Inflammation. Int J Mol Sci 2024; 25:6053. [PMID: 38892241 PMCID: PMC11172420 DOI: 10.3390/ijms25116053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/28/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
Glutamate functions as the major excitatory neurotransmitter for primary sensory neurons and has a crucial role in sensitizing peripheral nociceptor terminals producing sensitization. Glutaminase (GLS) is the synthetic enzyme that converts glutamine to glutamate. GLS-immunoreactivity (-ir) and enzyme activity are elevated in dorsal root ganglion (DRG) neuronal cell bodies during chronic peripheral inflammation, but the mechanism for this GLS elevation is yet to be fully characterized. It has been well established that, after nerve growth factor (NGF) binds to its high-affinity receptor tropomyosin receptor kinase A (TrkA), a retrograde signaling endosome is formed. This endosome contains the late endosomal marker Rab7GTPase and is retrogradely transported via axons to the cell soma located in the DRG. This complex is responsible for regulating the transcription of several critical nociceptive genes. Here, we show that this retrograde NGF signaling mediates the expression of GLS in DRG neurons during the process of peripheral inflammation. We disrupted the normal NGF/TrkA signaling in adjuvant-induced arthritic (AIA) Sprague Dawley rats by the pharmacological inhibition of TrkA or blockade of Rab7GTPase, which significantly attenuated the expression of GLS in DRG cell bodies. The results indicate that NGF/TrkA signaling is crucial for the production of glutamate and has a vital role in the development of neurogenic inflammation. In addition, our pain behavioral data suggest that Rab7GTPase can be a potential target for attenuating peripheral inflammatory pain.
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Affiliation(s)
- Vikramsingh Gujar
- Department of Anatomy and Cell Biology, Oklahoma State University, Center for Health Sciences, Tulsa, OK 74107, USA
| | - Radhika D. Pande
- Department of Biochemistry and Microbiology, Oklahoma State University, Center for Health Sciences, Tulsa, OK 74107, USA; (R.D.P.); (S.D.)
| | - Bhalchandra M. Hardas
- Department of Electronics Engineering, Shri Ramdeobaba College of Engineering and Management, Nagpur 440013, India;
| | - Subhas Das
- Department of Biochemistry and Microbiology, Oklahoma State University, Center for Health Sciences, Tulsa, OK 74107, USA; (R.D.P.); (S.D.)
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2
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Glutamate changes in healthy young adulthood. Eur Neuropsychopharmacol 2013; 23:1484-90. [PMID: 23245833 DOI: 10.1016/j.euroneuro.2012.11.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/31/2012] [Accepted: 11/09/2012] [Indexed: 11/20/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system and has been associated with several cognitive functions that are known to change with age. In rodents and humans age-related glutamate changes have been found in several brain areas. In this cross-sectional study the presence and extent of age-associated glutamate changes in the medial frontal cortex of healthy young adults were measured. Proton magnetic resonance spectroscopy ((1)H-MRS) and brain imaging were performed at 7 T in a 2 × 2 × 2 cm(3) voxel in 33 participants between 18 and 31 years old. Glutamate concentrations and grey and white matter volume could be successfully determined at an ultra-high magnetic field strength. Glutamate concentrations were lower in older individuals (0.33 mM/year). This decline is in line with grey matter thinning in the medial frontal cortex, but could not be explained by cortical thinning alone. Therefore, the decrease in glutamate in young adulthood may be due to physiological changes rather than anatomical changes.
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3
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Hädel S, Wirth C, Rapp M, Gallinat J, Schubert F. Effects of age and sex on the concentrations of glutamate and glutamine in the human brain. J Magn Reson Imaging 2013; 38:1480-7. [DOI: 10.1002/jmri.24123] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 02/20/2013] [Indexed: 11/08/2022] Open
Affiliation(s)
- Sven Hädel
- Department of Psychiatry and Psychotherapy; Psychiatric University Hospital St. Hedwig, Charité - University Medicine Berlin; Campus Mitte Berlin Germany
| | - Christoph Wirth
- Department of Psychiatry and Psychotherapy; Psychiatric University Hospital St. Hedwig, Charité - University Medicine Berlin; Campus Mitte Berlin Germany
| | - Michael Rapp
- Department of Psychiatry and Psychotherapy; Psychiatric University Hospital St. Hedwig, Charité - University Medicine Berlin; Campus Mitte Berlin Germany
- Geriatric Psychiatry Center; Psychiatric University Hospital St. Hedwig, Charité - University Medicine Berlin; Campus Mitte Berlin Germany
| | - Jürgen Gallinat
- Department of Psychiatry and Psychotherapy; Psychiatric University Hospital St. Hedwig, Charité - University Medicine Berlin; Campus Mitte Berlin Germany
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Kvamme E, Torgner IA, Roberg B. Kinetics and localization of brain phosphate activated glutaminase. J Neurosci Res 2001; 66:951-8. [PMID: 11746423 DOI: 10.1002/jnr.10041] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The cellular concentration of phosphate, the main activator of phosphate activated glutaminase (PAG) is rather constant in brain and kidney. The enzyme activity, however, is modulated by a variety of compounds affecting the binding of phosphate, such as glutamate, calcium, certain long chain fatty acids, fatty acyl CoA derivatives, members of the tricarboxylic acid cycle and protons (Kvamme et al. [2000] Neurochem. Res. 25:1407-1419). Therefore, the kinetic and allosteric properties of the enzyme are essential for regulating the enzyme activity in situ, especially because the enzymically active pool of PAG is assumed to have an external localization in the inner mitochondrial membrane, being exposed to cytosolic variation in the content of effectors. This has largely been overlooked. A hypothetical model for the allosteric interactions based on the sequential induced fit allosteric model by Koshland et al. ([1966] Biochemistry 5:365-385) is presented. Furthermore, it has been generally accepted that there exist only two isoforms of PAG, the kidney PAG that is similar to brain PAG, and the liver PAG. Therefore, the immunoreactivity of brain cells against kidney PAG antibodies has been considered a measure of PAG protein. Gomez-Fabre et al. ([2000] Biochem. J. 345:365-375) recently found, however, that a PAG mRNA from human breast cancer ZR75 cells is present in human brain and liver, but not in the kidney. We observed only traces of PAG immunoreactivity in cultured astrocytes and cultured neuroblastoma cells, regardless whether antibodies against the C- and N-termini of kidney PAG or antibodies against liver PAG were used, but considerable enzyme activity, demonstrating hitherto unknown isoforms of PAG (Torgner et al. [2001] FEBS Lett. 268(Suppl 1):PS2-031).
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Affiliation(s)
- E Kvamme
- Neurochemical Section, Institute of Medical Biochemistry, P.O. Box 1115, Blindern, Domus Medica, University of Oslo, Norway.
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Håberg A, Qu H, Saether O, Unsgård G, Haraldseth O, Sonnewald U. Differences in neurotransmitter synthesis and intermediary metabolism between glutamatergic and GABAergic neurons during 4 hours of middle cerebral artery occlusion in the rat: the role of astrocytes in neuronal survival. J Cereb Blood Flow Metab 2001; 21:1451-63. [PMID: 11740207 DOI: 10.1097/00004647-200112000-00010] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Astrocytes are intimately involved in both glutamate and gamma-aminobutyric acid (GABA) synthesis, and ischemia-induced disruption of normal neuroastrocytic interactions may have important implications for neuronal survival. The effects of middle cerebral artery occlusion (MCAO) on neuronal and astrocytic intermediary metabolism were studied in rats 30, 60, 120, and 240 minutes after MCAO using in vivo injection of [1-13C]glucose and [1,2- 13C]acetate combined with ex vivo 13C magnetic resonance spectroscopy and high-performance liquid chromatography analysis of the ischemic core (lateral caudoputamen and lower parietal cortex) and penumbra (upper frontoparietal cortex). In the ischemic core, both neuronal and astrocytic metabolism were impaired from 30 minutes MCAO. There was a continuous loss of glutamate from glutamatergic neurons that was not replaced as neuronal glucose metabolism and use of astrocytic precursors gradually declined. In GABAergic neurons astrocytic precursors were not used in GABA synthesis at any time after MCAO, and neuronal glucose metabolism and GABA-shunt activity declined with time. No flux through the tricarboxylic acid cycle was found in GABAergic neurons at 240 minutes MCAO, indicating neuronal death. In the penumbra, the neurotransmitter pool of glutamate coming from astrocytic glutamine was preserved while neuronal metabolism progressively declined, implying that glutamine contributed significantly to glutamate excitotoxicity. In GABAergic neurons, astrocytic precursors were used to a limited extent during the initial 120 minutes, and tricarboxylic acid cycle activity was continued for 240 minutes. The present study showed the paradoxical role that astrocytes play in neuronal survival in ischemia, and changes in the use of astrocytic precursors appeared to contribute significantly to neuronal death, albeit through different mechanisms in glutamatergic and GABAergic neurons.
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Affiliation(s)
- A Håberg
- Departments of Clinical Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
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Ye ZC, Ransom BR, Sontheimer H. (1R,3S)-1-Aminocyclopentane-1,3-dicarboxylic acid (RS-ACPD) reduces intracellular glutamate levels in astrocytes. J Neurochem 2001; 79:756-66. [PMID: 11723168 DOI: 10.1046/j.1471-4159.2001.00581.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
(+/-)-1-Aminocyclopentane-trans-1,3-dicarboxylic acid (t-ACPD) is an equimolar mixture of two enantiomers: (1S,3R)-1-Aminocyclopentane-1,3-dicarboxylic acid (SR-ACPD) and 1R,3S-1-Aminocyclopentane-1,3-dicarboxylic acid (RS-ACPD). t-ACPD and SR-ACPD have been commonly used as agonists for metabotropic glutamate receptors (mGluR). Here we demonstrated that RS-ACPD, but not SR-ACPD, is transported into astrocytes with a K(m) of 6.51 +/- 2.38 mM and V(max) of 22.8 +/- 3.4 nmol/mg/min. This low-affinity transport is Na(+)-dependent and is competitively blocked by glutamate or other substrates for the glutamate transporter. RS-ACPD therefore is probably taken up by the glutamate transporter. Prolonged incubation with high levels of RS-ACPD (> 500 microM) induced significant swelling of astrocytes. At lower concentrations (100 microM), RS-ACPD reduced intracellular glutamate content ([Glu](i)) by > 50% without obvious morphological changes. The reduction in [Glu](i) was accompanied by an increase in [glutamine](i). The RS-ACPD's effect on [Glu](i) required glutamine and high levels of phosphate, suggesting that RS-ACPD inhibited phosphate-activated glutaminase (PAG). These data suggest that astrocytic PAG is actively involved in determining the equilibrium between intracellular glutamate and glutamine. By reducing [Glu](i), RS-ACPD reduces the amount of glutamate available for release.
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Affiliation(s)
- Z C Ye
- Department of Neurology, University of Washington, Seattle, Washington, USA
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Segovia G, Del Arco A, Prieto L, Mora F. Glutamate-glutamine cycle and aging in striatum of the awake rat: effects of a glutamate transporter blocker. Neurochem Res 2001; 26:37-41. [PMID: 11358280 DOI: 10.1023/a:1007624531077] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study investigated the effects of aging on the actions of a specific glutamate reuptake blocker, L-trans-pyrrolidine-2, 4-dicarboxylic acid (PDC), in extracellular glutamate and glutamine in striatum of the awake rat. Microdialysis experiments were performed on young (2-3 months), middle-aged (12-14 months), aged (27-32 months) and very aged (37 months) male Wistar rats. Local infusion of PDC (1-4 mM) in striatum increased the dialysate concentration of glutamate and decreased dialysate concentration of glutamine in all the age-groups. In young rats, decreases of dialysate glutamine were correlated with increases of dialysate glutamate. The same profile glutamine/glutamate as in young rats was found in middle-aged, aged and very aged rats, which suggests that the action of glutamate on the glutamate-glutamine cycle in striatum of the awake rat is not modified as a consequence of aging. We also found a significant correlation between the increases of glutamate produced by PDC and the basal dialysate concentration of glutamine, a relationship that did show a significant change with age. Although the significance of this latter finding remains to be elucidated, it may be important to understand the changes in glutamate-glutamine cycle during aging.
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Affiliation(s)
- G Segovia
- Department of Physiology, Faculty of Medicine, Universidad Complutense, Madrid, Spain
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Segovia G, Porras A, Del Arco A, Mora F. Glutamatergic neurotransmission in aging: a critical perspective. Mech Ageing Dev 2001; 122:1-29. [PMID: 11163621 DOI: 10.1016/s0047-6374(00)00225-6] [Citation(s) in RCA: 254] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The effects of aging on glutamate neurotransmission in the brain is reviewed and evaluated. Glutamate is the neurotransmitter in most of the excitatory synapses and appears to be involved in functions such as motor behaviour, cognition and emotion, which alter with age. However, relatively few studies have been conducted to study the relationship between glutamate and aging of the brain. The studies presented here indicate the existence of a number of changes in the glutamatergic system during the normal process of aging. First, an age-related decrease of glutamate content in tissue from cerebral cortex and hippocampus has been reported, although it may be mainly a consequence of changes in metabolic activity rather than glutamatergic neurotransmission. On the other hand, studies in vitro and in vivo have shown no changes in glutamate release during aging. Since glutamate sampled in most of these studies is the result of a balance between release and uptake processes, the lack of changes in glutamate release may be due to compensatory changes in glutamate uptake. In fact, a reduced glutamate uptake capacity, as well as a loss in the number of high affinity glutamate transporters in glutamatergic terminals of aged rats, have been described. However, the most significant and consistent finding is the decrease in the density of glutamatergic NMDA receptors with age. A new perspective, in which glutamate interacts with other neurotransmitters to conform the substrates of specific circuits of the brain and its relevance to aging, is included in this review. In particular, studies from our laboratory suggest the existence of age-related changes in the interaction between glutamate and other neurotransmitters, e.g. dopamine and GABA, which are regionally specific.
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Affiliation(s)
- G Segovia
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Av. Complutense s/n, 28040, Madrid, Spain
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9
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Kvamme E, Roberg B, Torgner IA. Phosphate-activated glutaminase and mitochondrial glutamine transport in the brain. Neurochem Res 2000; 25:1407-19. [PMID: 11059811 DOI: 10.1023/a:1007668801570] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A review of the properties of purified and tissue bound phosphate activated glutaminase (PAG) in brain and kidney (pig and rat) is presented, based on kinetic, electron microscopic and immunocytochemical studies. PAG is a mitochondrial enzyme and two pools can be separated, a soluble and membrane associated one. Intact mitochondria appear to express PAG accessible only to the outer phase of the inner mitochondrial membrane. This PAG has properties similar to that of the membrane fraction and polymeric form of purified enzyme. PAG in the soluble fraction has properties similar to that of the monomeric form of purified enzyme and is assumed to be dormant due to the high matrix concentration of the inhibitor glutamate. A hypothetical model for the localization of PAG in the mitochondria is presented. The activity of PAG in vivo is assumed to be regulated by cytosolic glutamate and other compounds, that affect the activation by phosphate. Glutamine is transported into brain and kidney mitochondria by a protein catalyzed energy requiring process, which may be mediated by more than one protein. There is no correlation between glutamine hydrolysis and transport.
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Affiliation(s)
- E Kvamme
- Neurochemical Laboratory, University of Oslo, Blindern.
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10
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Affiliation(s)
- E Kvamme
- Neurochemical Laboratory, University of Oslo, Norway
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11
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12
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Assessment of regional phosphate-activated glutaminase (PAG) activity and kinetics in adult and aged Fischer-344 rats. J Am Aging Assoc 1994. [DOI: 10.1007/bf02434895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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