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Akçay G, Aslan M, Kipmen Korgun D, Çeker T, Akan E, Derin N. Effects of transcranial direct current stimulation on the glutamatergic pathway in the male rat hippocampus after experimental focal cerebral ischemia. J Neurosci Res 2024; 102:e25247. [PMID: 37800665 DOI: 10.1002/jnr.25247] [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: 07/13/2023] [Revised: 08/22/2023] [Accepted: 09/10/2023] [Indexed: 10/07/2023]
Abstract
This study aimed to assess the focal cerebral ischemia-induced changes in learning and memory together with glutamatergic pathway in rats and the effects of treatment of the animals with transcranial Direct Current Stimulation (tDCS). One hundred male rats were divided into five groups as sham, tDCS, Ischemia/Reperfusion (IR), IR + tDCS, and IR + E-tDCS groups. Learning, memory, and locomotor activity functions were evaluated by behavioral experiments in rats. Glutamate and glutamine levels, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate receptor (AMPAR1), N-Methyl-D-Aspartate receptors (NMDAR1 and NMDAR2A), vesicular glutamate transporter-1 (VGLUT-1), and excitatory amino acid transporters (EAAT1-3) mRNA expressions in hippocampus tissues were measured. Ischemic areas were analyzed by TTC staining. The increase was observed in IR + tDCS, and IR + E-tDCS groups compared to the IR group while a significant decrease was observed in IR group compared to the sham in the locomotor activity, learning, and memory tests. While glutamate and glutamine levels, AMPAR1, NMDAR1, NMDAR2A, VGLUT1, and EAAT1 mRNA expressions were significantly higher in IR group compared to the sham group, it was found to be significantly lower in IR + tDCS and IR + E-tDCS groups compared to the IR group. EAAT2 and EAAT3 mRNA expressions were significantly higher in IR + tDCS and IR + E-tDCS groups compared to the IR group. Ischemic areas were significantly decreased in IR + tDCS and IR + E-tDCS groups compared to the IR group. Current results suggest that tDCS application after ischemia improves learning and memory disorders and these effects of tDCS may be provided through transporters that regulate glutamate levels.
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Affiliation(s)
- Guven Akçay
- Faculty of Medicine, Department of Biophysics, Hitit University, Çorum, Turkey
| | - Mutay Aslan
- Faculty of Medicine, Department of Biochemistry, Akdeniz University, Antalya, Turkey
| | - Dijle Kipmen Korgun
- Faculty of Medicine, Department of Biochemistry, Akdeniz University, Antalya, Turkey
| | - Tugçe Çeker
- Faculty of Medicine, Department of Biochemistry, Akdeniz University, Antalya, Turkey
| | - Ezgi Akan
- Faculty of Medicine, Department of Biochemistry, Akdeniz University, Antalya, Turkey
| | - Narin Derin
- Faculty of Medicine, Department of Biophysics, Akdeniz University, Antalya, Turkey
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Baranovicova E, Kalenska D, Kaplan P, Kovalska M, Tatarkova Z, Lehotsky J. Blood and Brain Metabolites after Cerebral Ischemia. Int J Mol Sci 2023; 24:17302. [PMID: 38139131 PMCID: PMC10743907 DOI: 10.3390/ijms242417302] [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: 10/27/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
The study of an organism's response to cerebral ischemia at different levels is essential to understanding the mechanism of the injury and protection. A great interest is devoted to finding the links between quantitative metabolic changes and post-ischemic damage. This work aims to summarize the outcomes of the most studied metabolites in brain tissue-lactate, glutamine, GABA (4-aminobutyric acid), glutamate, and NAA (N-acetyl aspartate)-regarding their biological function in physiological conditions and their role after cerebral ischemia/reperfusion. We focused on ischemic damage and post-ischemic recovery in both experimental-including our results-as well as clinical studies. We discuss the role of blood glucose in view of the diverse impact of hyperglycemia, whether experimentally induced, caused by insulin resistance, or developed as a stress response to the cerebral ischemic event. Additionally, based on our and other studies, we analyze and critically discuss post-ischemic alterations in energy metabolites and the elevation of blood ketone bodies observed in the studies on rodents. To complete the schema, we discuss alterations in blood plasma circulating amino acids after cerebral ischemia. So far, no fundamental brain or blood metabolite(s) has been recognized as a relevant biological marker with the feasibility to determine the post-ischemic outcome or extent of ischemic damage. However, studies from our group on rats subjected to protective ischemic preconditioning showed that these animals did not develop post-ischemic hyperglycemia and manifested a decreased metabolic infringement and faster metabolomic recovery. The metabolomic approach is an additional tool for understanding damaging and/or restorative processes within the affected brain region reflected in the blood to uncover the response of the whole organism via interorgan metabolic communications to the stressful cerebral ischemic challenge.
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Affiliation(s)
- Eva Baranovicova
- Biomedical Center BioMed, Jessenius Faculty of Medicine, Comenius University in Bratislava, Mala Hora 4, 036 01 Martin, Slovakia;
| | - Dagmar Kalenska
- Department of Anatomy, Jessenius Faculty of Medicine, Comenius University in Bratislava, Mala Hora 4, 036 01 Martin, Slovakia
| | - Peter Kaplan
- Department of Medical Biochemistry, Jessenius Faculty of Medicine, Comenius University in Bratislava, Mala Hora 4, 036 01 Martin, Slovakia (Z.T.)
| | - Maria Kovalska
- Department of Histology and Embryology, Jessenius Faculty of Medicine, Comenius University in Bratislava, Mala Hora 4, 036 01 Martin, Slovakia
| | - Zuzana Tatarkova
- Department of Medical Biochemistry, Jessenius Faculty of Medicine, Comenius University in Bratislava, Mala Hora 4, 036 01 Martin, Slovakia (Z.T.)
| | - Jan Lehotsky
- Department of Medical Biochemistry, Jessenius Faculty of Medicine, Comenius University in Bratislava, Mala Hora 4, 036 01 Martin, Slovakia (Z.T.)
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Dąbrowska-Bouta B, Strużyńska L, Sidoryk-Węgrzynowicz M, Sulkowski G. Memantine Improves the Disturbed Glutamine and γ-Amino Butyric Acid Homeostasis in the Brain of Rats Subjected to Experimental Autoimmune Encephalomyelitis. Int J Mol Sci 2023; 24:13149. [PMID: 37685956 PMCID: PMC10488185 DOI: 10.3390/ijms241713149] [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: 07/19/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
Glutamine (Gln), glutamate (Glu), and γ-amino butyric acid (GABA) are essential amino acids for brain metabolism and function. Astrocyte-derived Gln is the precursor for the two most important neurotransmitters in the central nervous system (CNS), which are the excitatory neurotransmitter Glu and the inhibitory neurotransmitter GABA. In addition to their roles in neurotransmission, these amino acids can be used as alternative substrates in brain metabolism that enable metabolic coupling between astrocytes and neurons in the glutamate-glutamine cycle (GGC). The disturbed homeostasis of these amino acids within the tripartite synapse may be involved in the pathogenesis of various neurological diseases. Interactions between astrocytes and neurons in terms of Gln, Glu, and GABA homeostasis were studied in different phases of experimental allergic encephalomyelitis (EAE) in Lewis rats. The results of the study showed a decrease in the transport (uptake and release) of Gln and GABA in both neuronal and astrocyte-derived fractions. These effects were fully or partially reversed when the EAE rats were treated with memantine, a NMDA receptor antagonist. Changes in the expression and activity of selected glutamine/glutamate metabolizing enzymes, such as glutamine synthase (GS) and phosphate-activated glutaminase (PAG), which were affected by memantine, were observed in different phases of EAE. The results suggested perturbed homeostasis of Gln, Glu, and GABA during EAE, which may indicate alterations in neuron-astrocyte coupling and dysfunction of the tripartite synapse. Memantine appears to partially regulate the disturbed relationships between Gln, Glu, and GABA.
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Affiliation(s)
| | | | | | - Grzegorz Sulkowski
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Institute, Polish Academy of Sciences, 5 Pawińskiego Str., 02-106 Warsaw, Poland; (B.D.-B.); (L.S.); (M.S.-W.)
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Fernandes J, Uppal K, Liu KH, Hu X, Orr M, Tran V, Go YM, Jones DP. Antagonistic Interactions in Mitochondria ROS Signaling Responses to Manganese. Antioxidants (Basel) 2023; 12:804. [PMID: 37107179 PMCID: PMC10134992 DOI: 10.3390/antiox12040804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 03/29/2023] Open
Abstract
Antagonistic interaction refers to opposing beneficial and adverse signaling by a single agent. Understanding opposing signaling is important because pathologic outcomes can result from adverse causative agents or the failure of beneficial mechanisms. To test for opposing responses at a systems level, we used a transcriptome-metabolome-wide association study (TMWAS) with the rationale that metabolite changes provide a phenotypic readout of gene expression, and gene expression provides a phenotypic readout of signaling metabolites. We incorporated measures of mitochondrial oxidative stress (mtOx) and oxygen consumption rate (mtOCR) with TMWAS of cells with varied manganese (Mn) concentration and found that adverse neuroinflammatory signaling and fatty acid metabolism were connected to mtOx, while beneficial ion transport and neurotransmitter metabolism were connected to mtOCR. Each community contained opposing transcriptome-metabolome interactions, which were linked to biologic functions. The results show that antagonistic interaction is a generalized cell systems response to mitochondrial ROS signaling.
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Affiliation(s)
- Jolyn Fernandes
- Section of Neonatal-Perinatal Medicine, Department of Pediatrics, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Karan Uppal
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Ken H. Liu
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Xin Hu
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Michael Orr
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - ViLinh Tran
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Young-Mi Go
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Dean P. Jones
- Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, Department of Medicine, Emory University, Atlanta, GA 30322, USA
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Shaghaghi M, Cai K. Toward In Vivo MRI of the Tissue Proton Exchange Rate in Humans. BIOSENSORS 2022; 12:bios12100815. [PMID: 36290953 PMCID: PMC9599426 DOI: 10.3390/bios12100815] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/19/2022] [Accepted: 09/29/2022] [Indexed: 05/28/2023]
Abstract
Quantification of proton exchange rate (kex) is a challenge in MR studies. Current techniques either have low resolutions or are dependent on the estimation of parameters that are not measurable. The Omega plot method, on the other hand, provides a direct way for determining kex independent of the agent concentration. However, it cannot be used for in vivo studies without some modification due to the contributions from the water signal. In vivo tissue proton exchange rate (kex) MRI, based on the direct saturation (DS) removed Omega plot, quantifies the weighted average of kex of the endogenous tissue metabolites. This technique has been successfully employed for imaging the variation in the kex of ex vivo phantoms, as well as in vivo human brains in healthy subjects, and stroke or multiple sclerosis (MS) patients. In this paper, we present a brief review of the methods used for kex imaging with a focus on the development of in vivo kex MRI technique based on the DS-removed Omega plot. We then review the recent clinical studies utilizing this technique for better characterizing brain lesions. We also outline technical challenges for the presented technique and discuss its prospects for detecting tissue microenvironmental changes under oxidative stress.
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Affiliation(s)
- Mehran Shaghaghi
- Department of Radiology, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Kejia Cai
- Department of Radiology, University of Illinois at Chicago, Chicago, IL 60612, USA
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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Wu Z, Qian S, Zhao L, Zhang Z, Song C, Chen L, Gao H, Zhu W. Metabolomics-based study of the potential interventional effects of Xiao-Xu-Ming Decoction on cerebral ischemia/reperfusion rats. JOURNAL OF ETHNOPHARMACOLOGY 2022; 295:115379. [PMID: 35595221 DOI: 10.1016/j.jep.2022.115379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 05/07/2022] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Xiao-Xu-Ming Decoction (XXMD) is a classical Chinese medicinal compound for the treatment of ischemic stroke, which has good efficacy in clinical studies and also plays a neuroprotective role in pharmacological studies. AIM OF THE STUDY The purpose of this study is to investigate the potential and integral interventional effects of XXMD on cerebral ischemia/reperfusion rat model. MATERIALS AND METHODS In this study, 1H NMR metabolomics was used, combined with neurological functional assessments, cerebral infarct area measurements, and pathological staining including Nissl staining, immunofluorescence staining of NeuN and TUNEL, and immunohistochemical staining of MCT2, to analyze the metabolic effects of XXMD in the treatment of an ischemia/reperfusion rat model. RESULTS It's observed that XXMD treatment could improve the neurological deficit scores and reduce the cerebral infarct areas on cerebral ischemia/reperfusion rat model. The pathological staining results performed that XXMD treatment could improve the decrease of Nissl bodies and the expression of NeuN and MCT2, reduce the high expression of TUNEL. In 1H NMR study, it revealed that the metabolic patterns among three experimental groups were different, the level of lactate, acetate, NAA, glutamate, and GABA were improved to varying degrees in different brain area. CONCLUSION Our findings indicated that XXMD has positive effect on neuroprotection and improvement of metabolism targeting cerebral ischemic injury in rats, which showed great potential for ischemic stroke.
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Affiliation(s)
- Ziqian Wu
- Department of Neurology, Wenzhou Hospital of Traditional Chinese Medicine Affiliated to Zhejiang Chinese Medical University, Wenzhou, China
| | - Shiyan Qian
- The Third School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Liangcai Zhao
- Institute of Metabonomics & Medical NMR, School of Pharmaceutical Sciences, Wenzhou Medical University, China
| | - Zaiheng Zhang
- The Third School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Chengcheng Song
- Department of Neurology, Wenzhou Hospital of Traditional Chinese Medicine Affiliated to Zhejiang Chinese Medical University, Wenzhou, China
| | - Ling Chen
- Department of Neurology, Wenzhou Hospital of Traditional Chinese Medicine Affiliated to Zhejiang Chinese Medical University, Wenzhou, China
| | - Hongchang Gao
- Institute of Metabonomics & Medical NMR, School of Pharmaceutical Sciences, Wenzhou Medical University, China.
| | - Wenzong Zhu
- Department of Neurology, Wenzhou Hospital of Traditional Chinese Medicine Affiliated to Zhejiang Chinese Medical University, Wenzhou, China.
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Kim BJ, Youn DH, Chang IB, Kang K, Jeon JP. Identification of Differentially-Methylated Genes and Pathways in Patients with Delayed Cerebral Ischemia Following Subarachnoid Hemorrhage. J Korean Neurosurg Soc 2021; 65:4-12. [PMID: 34320780 PMCID: PMC8752893 DOI: 10.3340/jkns.2021.0035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 05/14/2021] [Indexed: 11/27/2022] Open
Abstract
Objective We reported the differentially methylated genes in patients with subarachnoid hemorrhage (SAH) using bioinformatics analyses to explore the biological characteristics of the development of delayed cerebral ischemia (DCI). Methods DNA methylation profiles obtained from 40 SAH patients from an epigenome-wide association study were analyzed. Functional enrichment analysis, protein-protein interaction (PPI) network, and module analyses were carried out. Results A total of 13 patients (32.5%) experienced DCI during the follow-up. In total, we categorized the genes into the two groups of hypermethylation (n=910) and hypomethylation (n=870). The hypermethylated genes referred to biological processes of organic cyclic compound biosynthesis, nucleobase-containing compound biosynthesis, heterocycle biosynthesis, aromatic compound biosynthesis and cellular nitrogen compound biosynthesis. The hypomethylated genes referred to biological processes of carbohydrate metabolism, the regulation of cell size, and the detection of a stimulus, and molecular functions of amylase activity, and hydrolase activity. Based on PPI network and module analysis, three hypermethylation modules were mainly associated with antigen-processing, Golgi-to-ER retrograde transport, and G alpha (i) signaling events, and two hypomethylation modules were associated with post-translational protein phosphorylation and the regulation of natural killer cell chemotaxis. VHL, KIF3A, KIFAP3, RACGAP1, and OPRM1 were identified as hub genes for hypermethylation, and ALB and IL5 as hub genes for hypomethylation. Conclusion This study provided novel insights into DCI pathogenesis following SAH. Differently methylated hub genes can be useful biomarkers for the accurate DCI diagnosis.
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Affiliation(s)
- Bong Jun Kim
- Institute of New Frontier Stroke Research, Hallym University College of Medicine, Chuncheon, Korea
| | - Dong Hyuk Youn
- Institute of New Frontier Stroke Research, Hallym University College of Medicine, Chuncheon, Korea
| | - In Bok Chang
- Department of Neurosurgery, Hallym University College of Medicine, Chuncheon, Korea
| | - Keunsoo Kang
- Department of Microbiology, College of Science & Technology, Dankook University, Cheonan, Korea
| | - Jin Pyeong Jeon
- Department of Neurosurgery, Hallym University College of Medicine, Chuncheon, Korea.,Genetic and Research Inc., Chuncheon, Korea
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Wu QJ, Jiao C, Liu ZH, Cheng BY, Liao JH, Zhu DD, Ma Y, Li YX, Li W. Effect of glutamine on the growth performance, digestive enzyme activity, absorption function, and mRNA expression of intestinal transporters in heat-stressed chickens. Res Vet Sci 2020; 134:51-57. [PMID: 33296811 DOI: 10.1016/j.rvsc.2020.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 10/22/2020] [Accepted: 12/01/2020] [Indexed: 11/24/2022]
Abstract
To explore the effect of glutamine (Gln) on the growth performance, digestive enzyme activity, absorption function and mRNA expression of intestinal transporters in heat-stressed chickens, 540 21-day-old Arbor Acres broilers were randomly assigned to a control group (no stress, NS), Gln group (Chickens were administered 0.5% and 1.0% Gln, respectively), heat stress group (HT), and Gln + HT group (Chickens were administered 0.5% and 1.0% Gln, respectively). The chickens in the HT and Gln + HT groups were reared under HT (36 ± 1 °C for 10 h/d and 22 ± 1 °C for 14 h/d), for 21 days. In contrast to the NS group, heat stress caused a reduction in the body weight gain (BWG); feed intake (FI); activity of trypsin, lipase, alkaline phosphatases, Ca2+ and Mg2+ adenosine triphosphatases, and Na+-K+-ATPase; and content of glutathione and d-xylose (P < 0.05) in the other groups. In addition, compared to the F:G and expression levels in the NS group, the heat stress increased the feed intake:body weight gain (F:G) and mRNA expression levels of SGLT1, CaBP-D28k, and L-GSBP (P < 0.05). Furthermore, HT-challenged birds were pretreated with Gln, the BWG; FI; activity of trypsin, lipase, alkaline phosphatase, Ca2+ and Mg2+ adenosine triphosphatases, and Na+-K+-ATPase; and content of glutathione and d-xylose (P < 0.05) were dramatically increased, but it decreased the F:G and mRNA expression levels of SGLT1, CaBP-D28k, and L-GSBP (P < 0.05) in the HT group. In summary, Gln can effectively improve growth performance and may promote digestion and absorption in the gastrointestinal tract by mediating the mRNA expression level of nutrient transporters and Gln metabolism in heat-stressed broilers.
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Affiliation(s)
- Qiu Jue Wu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China.
| | - Chong Jiao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Zhi Hao Liu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Bin Yao Cheng
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Jia Hui Liao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Dou Dou Zhu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Yan Ma
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Yuan Xiao Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
| | - Wang Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang 471003, Henan, PR China
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Novel proton exchange rate MRI presents unique contrast in brains of ischemic stroke patients. J Neurosci Methods 2020; 346:108926. [PMID: 32896540 DOI: 10.1016/j.jneumeth.2020.108926] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/23/2020] [Accepted: 08/31/2020] [Indexed: 01/03/2023]
Abstract
BACKGROUND To map and quantify the proton exchange rate (kex) of brain tissues using improved omega plots in ischemic stroke patients and to investigate whether kex can serve as a potential endogenous surrogate imaging biomarker for detecting the metabolic state and the pathologic changes due to ischemic stroke. NEW METHOD Three sets of Z-spectra were acquired from seventeen ischemic stroke patients using a spin echo-echo planar imaging sequence with pre-saturation chemical exchange saturation transfer (CEST) pulse at B1 of 1.5, 2.5, and 3.5 μT, respectively. Pixel-wise kex was calculated from improved omega plot of water direct saturation (DS)-removed Z-spectral signals. RESULTS The derived kex maps can differentiate infarcts from contralateral normal brain tissues with significantly increased signal (893 ± 52 s-1vs. 739 ± 34 s-1, P < 0.001). COMPARISON WITH EXISTING METHOD(S) The kex maps were found to be different from conventional contrasts from diffusion-weighted imaging (DWI), CEST, and semi-solid magnetization transfer (MT) MRI. In brief, kex MRI showed larger lesion areas than DWI with different degrees and different lesion contrast compared to CEST and MT. CONCLUSIONS In this preliminary translational research, the kex MRI based on DS-removed omega plots has been demonstrated for in vivo imaging of clinical ischemic stroke patients. As a noninvasive and unique MRI contrast, kex MRI at 3 T may serve as a potential surrogate imaging biomarker for the metabolic changes of stroke and help for monitoring the evolution and the treatment of stroke.
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Yon M, Decoville M, Sarou-Kanian V, Fayon F, Birman S. Spatially-resolved metabolic profiling of living Drosophila in neurodegenerative conditions using 1H magic angle spinning NMR. Sci Rep 2020; 10:9516. [PMID: 32528106 PMCID: PMC7289880 DOI: 10.1038/s41598-020-66218-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
Drosophila flies are versatile animal models for the study of gene mutations in neuronal pathologies. Their small size allows performing in vivo Magic Angle Spinning (MAS) experiments to obtain high-resolution 1H nuclear magnetic resonance (NMR) spectra. Here, we use spatially-resolved 1H high-resolution MAS NMR to investigate in vivo metabolite contents in different segments of the fly body. A comparative study of metabolic changes was performed for three neurodegenerative disorders: two cell-specific neuronal and glial models of Huntington disease (HD) and a model of glutamate excitotoxicity. It is shown that these pathologies are characterized by specific and sometimes anatomically localized variations in metabolite concentrations. In two cases, the modifications of 1H MAS NMR spectra localized in fly heads were significant enough to allow the creation of a predictive model.
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Affiliation(s)
- Maxime Yon
- CEMHTI UPR3079, CNRS, Université d'Orléans, F-45071, Orléans, France
| | | | | | - Franck Fayon
- CEMHTI UPR3079, CNRS, Université d'Orléans, F-45071, Orléans, France
| | - Serge Birman
- GCRN-LPC UMR8249, CNRS, ESPCI Paris, PSL Research University, F-75005, Paris, France
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Piccirillo S, Magi S, Castaldo P, Preziuso A, Lariccia V, Amoroso S. NCX and EAAT transporters in ischemia: At the crossroad between glutamate metabolism and cell survival. Cell Calcium 2020; 86:102160. [PMID: 31962228 DOI: 10.1016/j.ceca.2020.102160] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 01/29/2023]
Abstract
Energy metabolism impairment is a central event in the pathophysiology of ischemia. The limited availability of glucose and oxygen strongly affects mitochondrial activity, thus leading to ATP depletion. In this setting, the switch to alternative energy sources could ameliorate cells survival by enhancing ATP production, thus representing an attractive strategy for ischemic treatment. In this regard, some studies have recently re-evaluated the metabolic role of glutamate and its potential to promote cell survival under pathological conditions. In the present review, we discuss the ability of glutamate to exert an "energizing role" in cardiac and neuronal models of hypoxia/reoxygenation (H/R) injury, focusing on the Na+/Ca2+ exchanger (NCX) and the Na+-dependent excitatory amino acid transporters (EAATs) as key players in this metabolic pathway.
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Affiliation(s)
- Silvia Piccirillo
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Simona Magi
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy.
| | - Pasqualina Castaldo
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Alessandra Preziuso
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Vincenzo Lariccia
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Salvatore Amoroso
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
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Magi S, Piccirillo S, Amoroso S. The dual face of glutamate: from a neurotoxin to a potential survival factor-metabolic implications in health and disease. Cell Mol Life Sci 2019; 76:1473-1488. [PMID: 30599069 PMCID: PMC11105246 DOI: 10.1007/s00018-018-3002-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/12/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system. Beyond this function, glutamate also plays a key role in intermediary metabolism in all organs and tissues, linking carbohydrate and amino acid metabolism via the tricarboxylic acid cycle. Under both physiological and pathological conditions, we have recently found that the ability of glutamate to fuel cell metabolism selectively relies on the activity of two main transporters: the sodium-calcium exchanger (NCX) and the sodium-dependent excitatory amino-acid transporters (EAATs). In ischemic settings, when glutamate is administered at the onset of the reoxygenation phase, the coordinate activity of EAAT and NCX allows glutamate to improve cell viability by stimulating ATP production. So far, this phenomenon has been observed in both cardiac and neuronal models. In this review, we focus on the most recent findings exploring the unusual activity of glutamate as a potential survival factor in different settings.
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Affiliation(s)
- Simona Magi
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy.
| | - Silvia Piccirillo
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Salvatore Amoroso
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
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13
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Glutamate as a potential "survival factor" in an in vitro model of neuronal hypoxia/reoxygenation injury: leading role of the Na +/Ca 2+ exchanger. Cell Death Dis 2018; 9:731. [PMID: 29955038 PMCID: PMC6023866 DOI: 10.1038/s41419-018-0784-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/04/2018] [Accepted: 06/11/2018] [Indexed: 12/23/2022]
Abstract
In brain ischemia, reduction in oxygen and substrates affects mitochondrial respiratory chain and aerobic metabolism, culminating in ATP production impairment, ionic imbalance, and cell death. The restoration of blood flow and reoxygenation are frequently associated with exacerbation of tissue injury, giving rise to ischemia/reperfusion (I/R) injury. In this setting, the imbalance of brain bioenergetics induces important metabolic adaptations, including utilization of alternative energy sources, such as glutamate. Although glutamate has long been considered as a neurotoxin, it can also be used as intermediary metabolite for ATP synthesis, and both the Na+/Ca2+ exchanger (NCX) and the Na+-dependent excitatory amino-acid transporters (EAATs) are essential in this pathway. Here we analyzed the role of NCX in the potential of glutamate to improve metabolism and survival of neuronal cells subjected to hypoxia/reoxygenation (H/R). In SH-SY5Y neuroblastoma cells differentiated into a neuron-like state, H/R produced a significant cell damage, a decrease in ATP cellular content, and intracellular Ca2+ alterations. Exposure to glutamate at the onset of the reoxygenation phase attenuated H/R-induced cell damage and evoked a significant raise in intracellular ATP levels. Furthermore, we found that in H/R cells NCX reverse-mode activity was reduced, and that glutamate limited such reduction. All the effects induced by glutamate supplementation were lost when cells were transfected with small interfering RNA against NCX1 and EAAT3, suggesting the need of a specific functional interplay between these proteins for glutamate-induced protection. Collectively, our results revealed the potential beneficial effect of glutamate in an in vitro model of H/R injury and focused on the essential role exerted by NCX1. Although preliminary, these findings could be a starting point to further investigate in in vivo systems such protective effect in ischemic settings, shedding a new light on the classical view of glutamate as detrimental factor.
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14
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Profilo E, Peña-Altamira LE, Corricelli M, Castegna A, Danese A, Agrimi G, Petralla S, Giannuzzi G, Porcelli V, Sbano L, Viscomi C, Massenzio F, Palmieri EM, Giorgi C, Fiermonte G, Virgili M, Palmieri L, Zeviani M, Pinton P, Monti B, Palmieri F, Lasorsa FM. Down-regulation of the mitochondrial aspartate-glutamate carrier isoform 1 AGC1 inhibits proliferation and N-acetylaspartate synthesis in Neuro2A cells. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1422-1435. [DOI: 10.1016/j.bbadis.2017.02.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/02/2017] [Accepted: 02/20/2017] [Indexed: 12/26/2022]
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15
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Acosta C, Anderson HD, Anderson CM. Astrocyte dysfunction in Alzheimer disease. J Neurosci Res 2017; 95:2430-2447. [PMID: 28467650 DOI: 10.1002/jnr.24075] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/07/2017] [Accepted: 04/10/2017] [Indexed: 12/11/2022]
Abstract
Astrocytes are glial cells that are distributed throughout the central nervous system in an arrangement optimal for chemical and physical interaction with neuronal synapses and brain blood supply vessels. Neurotransmission modulates astrocytic excitability by activating an array of cell surface receptors and transporter proteins, resulting in dynamic changes in intracellular Ca2+ or Na+ . Ionic and electrogenic astrocytic changes, in turn, drive vital cell nonautonomous effects supporting brain function, including regulation of synaptic activity, neuronal metabolism, and regional blood supply. Alzheimer disease (AD) is associated with aberrant oligomeric amyloid β generation, which leads to extensive proliferation of astrocytes with a reactive phenotype and abnormal regulation of these processes. Astrocytic morphology, Ca2+ responses, extracellular K+ removal, glutamate transport, amyloid clearance, and energy metabolism are all affected in AD, resulting in a deleterious set of effects that includes glutamate excitotoxicity, impaired synaptic plasticity, reduced carbon delivery to neurons for oxidative phosphorylation, and dysregulated linkages between neuronal energy demand and regional blood supply. This review summarizes how astrocytes are affected in AD and describes how these changes are likely to influence brain function. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Crystal Acosta
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Research, Winnipeg, Manitoba, Canada
| | - Hope D Anderson
- Canadian Centre for Agri-food Research in Health and Medicine, St. Boniface Hospital Research, Winnipeg, Manitoba, Canada.,College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Christopher M Anderson
- Department of Pharmacology and Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, Manitoba, Canada
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16
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Cerdán S. Twenty-seven Years of Cerebral Pyruvate Recycling. Neurochem Res 2017; 42:1621-1628. [PMID: 28101749 DOI: 10.1007/s11064-017-2173-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/02/2017] [Accepted: 01/02/2017] [Indexed: 10/20/2022]
Abstract
Cerebral pyruvate recycling is a metabolic pathway deriving carbon skeletons and reducing equivalents from mitochondrial oxaloacetate and malate, to the synthesis of mitochondrial and cytosolic pyruvate, lactate and alanine. The pathway allows both, to provide the tricarboxylic acid cycle with pyruvate molecules produced from alternative substrates to glucose and, to generate reducing equivalents necessary for the operation of NADPH requiring processes. At the cellular level, pyruvate recycling involves the activity of malic enzyme, or the combined activities of phosphoenolpyruvate carboxykinase and pyruvate kinase, as well as of those transporters of the inner mitochondrial membrane exchanging the corresponding intermediates. Its cellular localization between the neuronal or astrocytic compartments of the in vivo brain has been controversial, with evidences favoring either a primarily neuronal or glial localizations, more recently accepted to occur in both environments. This review provides a brief history on the detection and characterization of the pathway, its relations with the early developments of cerebral high resolution 13C NMR, and its potential neuroprotective functions under hypoglycemic conditions or ischemic redox stress.
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Affiliation(s)
- Sebastián Cerdán
- Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC/UAM, c/ Arturo Duperier 4, 28029, Madrid, Spain.
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17
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Kim AY, Jeong KH, Lee JH, Kang Y, Lee SH, Baik EJ. Glutamate dehydrogenase as a neuroprotective target against brain ischemia and reperfusion. Neuroscience 2016; 340:487-500. [PMID: 27845178 DOI: 10.1016/j.neuroscience.2016.11.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 11/02/2016] [Accepted: 11/06/2016] [Indexed: 01/13/2023]
Abstract
Deregulation of glutamate homeostasis is associated with degenerative neurological disorders. Glutamate dehydrogenase (GDH) is important for glutamate metabolism and plays a central role in expanding the pool of tricarboxylic acid (TCA) cycle intermediate alpha-ketoglutarate (α-KG), which improves overall bioenergetics. Under high energy demand, maintenance of ATP production results in functionally active mitochondria. Here, we tested whether the modulation of GDH activity can rescue ischemia/reperfusion-induced neuronal death in an in vivo mouse model of middle artery occlusion and an in vitro oxygen/glucose depletion model. Iodoacetate, an inhibitor of glycolysis, was also used in a model of energy failure, remarkably depleting ATP and α-KG. To stimulate GDH activity, the GDH activator 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid and potential activator beta-lapachone were used. The GDH activators restored α-KG and ATP levels in the injury models and provided potent neuroprotection. We also found that beta-lapachone increased glutamate utilization, accompanied by a reduction in extracellular glutamate. Thus, our hypothesis that mitochondrial GDH activators increase α-KG production as an alternative energy source for use in the TCA cycle under energy-depleted conditions was confirmed. Our results suggest that increasing GDH-mediated glutamate oxidation represents a new therapeutic intervention for neurodegenerative disorders, including stoke.
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Affiliation(s)
- A Young Kim
- Department of Physiology, Ajou University School of Medicine, Suwon 16499, Republic of Korea; Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Kyeong-Hoon Jeong
- Gachon University of Medicine and Science, Incheon 406-840, Republic of Korea
| | - Jae Ho Lee
- Department of Biochemistry, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Yup Kang
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Soo Hwan Lee
- Department of Physiology, Ajou University School of Medicine, Suwon 16499, Republic of Korea
| | - Eun Joo Baik
- Department of Physiology, Ajou University School of Medicine, Suwon 16499, Republic of Korea; Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 16499, Republic of Korea.
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18
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Thibodeau A, Geng X, Previch LE, Ding Y. Pyruvate dehydrogenase complex in cerebral ischemia-reperfusion injury. Brain Circ 2016; 2:61-66. [PMID: 30276274 PMCID: PMC6126256 DOI: 10.4103/2394-8108.186256] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 06/02/2016] [Accepted: 06/14/2016] [Indexed: 11/11/2022] Open
Abstract
Pyruvate dehydrogenase (PDH) complex is a mitochondrial matrix enzyme that serves a critical role in the conversion of anaerobic to aerobic cerebral energy. The regulatory complexity of PDH, coupled with its significant influence in brain metabolism, underscores its susceptibility to, and significance in, ischemia-reperfusion injury. Here, we evaluate proposed mechanisms of PDH-mediated neurodysfunction in stroke, including oxidative stress, altered regulatory enzymatic control, and loss of PDH activity. We also describe the neuroprotective influence of antioxidants, dichloroacetate, acetyl-L-carnitine, and combined therapy with ethanol and normobaric oxygen, explained in relation to PDH modulation. Our review highlights the significance of PDH impairment in stroke injury through an understanding of the mechanisms by which it is modulated, as well as an exploration of neuroprotective strategies available to limit its impairment.
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Affiliation(s)
- Alexa Thibodeau
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Xiaokun Geng
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA.,China-America Institute of Neuroscience, Luhe Hospital, Capital Medical University, Beijing, China.,Department of Neurology, Luhe Hospital, Capital Medical University, Beijing, China
| | - Lauren E Previch
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Yuchuan Ding
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA.,China-America Institute of Neuroscience, Luhe Hospital, Capital Medical University, Beijing, China
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19
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Hu H, Bai X, Shah AA, Dai S, Wang L, Hua J, Che C, He S, Wen A, Jiang J. Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment. INTERNATIONAL JOURNAL OF BIOMETEOROLOGY 2016; 60:907-915. [PMID: 26493197 DOI: 10.1007/s00484-015-1084-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 10/10/2015] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased (P < 0.05) daily weight gain (DWG), daily feed consumption (DFC), the concentrations of Gln, glutamate (Glu), and GABA, and the activities of glutaminase and glutamic acid decarboxylase (GAD) in breast muscle at 28, 35, and 42 days, while it increased (P < 0.05) the activities of glutamine synthetase (GS) and gamma-aminobutyric acid transaminase (GABA-T) at 28, 35, and 42 days. Dietary Gln and GABA improved (P < 0.05) DWG and DFC of broilers under cyclic HS during 28-42 days. In breast muscle, the Gln supplementation increased (P < 0.05) the concentrations of Gln (28, 35, and 42 days), Glu (28, 35, and 42 days), and GABA (42 days) and the activities of glutaminase (28, 35, and 42 days) and GAD (28, 35, and 42 days) but decreased (P < 0.05) GS activities at 28, 35, and 42 days and GABA-T activities at 28 days. The addition of GABA increased (P < 0.05) the concentrations of Gln and Glu and activities of glutaminase and GAD, while it decreased (P < 0.05) GABA-T activities at 28, 35, and 42 days. Significant interactions (P < 0.05) between Gln and GABA were found on breast skeletal muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA metabolism of broilers.
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Affiliation(s)
- Hong Hu
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
| | - Xi Bai
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Assar Ali Shah
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China
| | - Sifa Dai
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China.
| | - Like Wang
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
| | - Jinling Hua
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
| | - Chuanyan Che
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
| | - Shaojun He
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
| | - Aiyou Wen
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
| | - Jinpeng Jiang
- College of Animal Science, Anhui Science and Technology University, No. 9 Donghua road, Fengyang, 233100, People's Republic of China
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20
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Jayakumar AR, Norenberg MD. Glutamine Synthetase: Role in Neurological Disorders. ADVANCES IN NEUROBIOLOGY 2016; 13:327-350. [PMID: 27885636 DOI: 10.1007/978-3-319-45096-4_13] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Glutamine synthetase (GS) is an ATP-dependent enzyme found in most species that synthesizes glutamine from glutamate and ammonia. In brain, GS is exclusively located in astrocytes where it serves to maintain the glutamate-glutamine cycle, as well as nitrogen metabolism. Changes in the activity of GS, as well as its gene expression, along with excitotoxicity, have been identified in a number of neurological conditions. The literature describing alterations in the activation and gene expression of GS, as well as its involvement in different neurological disorders, however, is incomplete. This review summarizes changes in GS gene expression/activity and its potential contribution to the pathogenesis of several neurological disorders, including hepatic encephalopathy, ischemia, epilepsy, Alzheimer's disease, amyotrophic lateral sclerosis, traumatic brain injury, Parkinson's disease, and astroglial neoplasms. This review also explores the possibility of targeting GS in the therapy of these conditions.
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Affiliation(s)
| | - Michael D Norenberg
- Laboratory of Neuropathology, Veterans Affairs Medical Center, Miami, FL, USA.
- Departments of Pathology, University of Miami School of Medicine, 016960, Miami, FL, 33101, USA.
- Departments of Biochemistry & Molecular Biology, University of Miami School of Medicine, Miami, FL, USA.
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21
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Salminen A, Jouhten P, Sarajärvi T, Haapasalo A, Hiltunen M. Hypoxia and GABA shunt activation in the pathogenesis of Alzheimer's disease. Neurochem Int 2015; 92:13-24. [PMID: 26617286 DOI: 10.1016/j.neuint.2015.11.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 11/16/2015] [Accepted: 11/18/2015] [Indexed: 12/21/2022]
Abstract
We have previously observed that the conversion of mild cognitive impairment to definitive Alzheimer's disease (AD) is associated with a significant increase in the serum level of 2,4-dihydroxybutyrate (2,4-DHBA). The metabolic generation of 2,4-DHBA is linked to the activation of the γ-aminobutyric acid (GABA) shunt, an alternative energy production pathway activated during cellular stress, when the function of Krebs cycle is compromised. The GABA shunt can be triggered by local hypoperfusion and subsequent hypoxia in AD brains caused by cerebral amyloid angiopathy. Succinic semialdehyde dehydrogenase (SSADH) is a key enzyme in the GABA shunt, converting succinic semialdehyde (SSA) into succinate, a Krebs cycle intermediate. A deficiency of SSADH activity stimulates the conversion of SSA into γ-hydroxybutyrate (GHB), an alternative route from the GABA shunt. GHB can exert not only acute neuroprotective activities but unfortunately also chronic detrimental effects which may lead to cognitive impairment. Subsequently, GHB can be metabolized to 2,4-DHBA and secreted from the brain. Thus, the activation of the GABA shunt and the generation of GHB and 2,4-DHBA can have an important role in the early phase of AD pathogenesis.
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Affiliation(s)
- Antero Salminen
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, P.O. Box 1627, FIN-70211 Kuopio, Finland.
| | - Paula Jouhten
- VTT Technical Research Centre of Finland, FIN-00014 Helsinki, Finland; EMBL European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Timo Sarajärvi
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, P.O. Box 1627, FIN-70211 Kuopio, Finland; Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FIN-70211 Kuopio, Finland
| | - Annakaisa Haapasalo
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, P.O. Box 1627, FIN-70211 Kuopio, Finland; Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, Neulaniementie 2, P.O. Box 1627, FIN-70211 Kuopio, Finland; Department of Neurology, Kuopio University Hospital, P.O. Box 100, FI-70029 KYS, Finland
| | - Mikko Hiltunen
- Institute of Clinical Medicine - Neurology, University of Eastern Finland, P.O. Box 1627, FIN-70211 Kuopio, Finland; Department of Neurology, Kuopio University Hospital, P.O. Box 100, FI-70029 KYS, Finland; Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FIN-70211 Kuopio, Finland
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22
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Chauhan A, Sharma U, Jagannathan NR, Gupta YK. Rapamycin ameliorates brain metabolites alterations after transient focal ischemia in rats. Eur J Pharmacol 2015; 757:28-33. [DOI: 10.1016/j.ejphar.2015.03.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 02/19/2015] [Accepted: 03/01/2015] [Indexed: 11/30/2022]
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23
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YAN GEN, DAI ZHUOZHI, XUAN YINGHUA, WU RENHUA. Early metabolic changes following ischemia onset in rats: an in vivo diffusion-weighted imaging and 1H-magnetic resonance spectroscopy study at 7.0 T. Mol Med Rep 2015; 11:4109-14. [PMID: 25634261 PMCID: PMC4394971 DOI: 10.3892/mmr.2015.3283] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 01/02/2015] [Indexed: 02/05/2023] Open
Abstract
Despite improvements in imaging techniques, it remains challenging to quantitatively assess the time of ischemic onset of an acute ischemic stroke. It is crucial to evaluate the early signs of infarction, which are predictive of responses to recombinant tissue plasminogen activator within a treatment window of 4.5 h after stroke induction. The aim of the present study was to assess and quantify the onset time for hyperacute middle cerebral artery occlusion (MCAO) ischemic stroke by measuring the apparent diffusion coefficient (ADC) of diffusion‑weighted imaging (DWI) and 1H‑magnetic resonance spectroscopy (MRS) at 7.0 T. DWI, conventional T2‑weighted imaging (T2WI) and subsequent focal ADCs were employed to evaluate ischemic brain lesions in a rat model of MCAO (n=20) at different time‑points following a stroke. A quantitation of local changes in metabolite concentrations within the lesions was performed using MRS. Proton metabolites were quantified automatically using LCModel software. At 30 min after MCAO, intense signals were observed in the DWI spectra of all animals. No abnormal signal was observed within 3 h by T2WI. ADC images of the central area, peripheral striping and on the fringes of the infarction demonstrated a lower signal than that of the normal side. The ADC decreased significantly within 30 min after infarction, followed by a gradual elevation in volatility levels and then becoming relatively stable at a lower level 3 h later. MRS exhibited a consistent elevation of lactate and reduced N‑acetyl aspartic acid. Glutamate and taurine reached a maximum 2 h after MCAO and began to decrease 1 h later. In conclusion, the present study demonstrated that hyperacute ischemic stroke can be quantitatively detected with the application of ADC, DWI and MRS. These methods may also be used to quantitatively assess the ischemic onset time of a hyperacute stroke.
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Affiliation(s)
- GEN YAN
- Department of Radiology, Affiliated Hospital, Jiangnan University, Wuxi, Jiangsu 214062, P.R. China
- Department of Radiology, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China
| | - ZHUOZHI DAI
- Department of Radiology, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China
- Provincial Key Laboratory of Medical Molecular Imaging, Shantou, Guangdong 515041, P.R. China
| | - YINGHUA XUAN
- Department of Basic Medicine, Jiangnan University Medical School, Wuxi, Jiangsu 214122, P.R. China
| | - RENHUA WU
- Department of Radiology, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong 515041, P.R. China
- Provincial Key Laboratory of Medical Molecular Imaging, Shantou, Guangdong 515041, P.R. China
- Correspondence to: Professor Renhua Wu, Department of Radiology, The Second Affiliated Hospital, Shantou University Medical College, 22 Dongxiabei Road, Shantou, Guangdong 515041, P.R. China, E-mail:
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Welcome MO, Mastorakis NE, Pereverzev VA. Sweet taste receptor signaling network: possible implication for cognitive functioning. Neurol Res Int 2015; 2015:606479. [PMID: 25653876 PMCID: PMC4306214 DOI: 10.1155/2015/606479] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 12/20/2014] [Indexed: 01/01/2023] Open
Abstract
Sweet taste receptors are transmembrane protein network specialized in the transmission of information from special "sweet" molecules into the intracellular domain. These receptors can sense the taste of a range of molecules and transmit the information downstream to several acceptors, modulate cell specific functions and metabolism, and mediate cell-to-cell coupling through paracrine mechanism. Recent reports indicate that sweet taste receptors are widely distributed in the body and serves specific function relative to their localization. Due to their pleiotropic signaling properties and multisubstrate ligand affinity, sweet taste receptors are able to cooperatively bind multiple substances and mediate signaling by other receptors. Based on increasing evidence about the role of these receptors in the initiation and control of absorption and metabolism, and the pivotal role of metabolic (glucose) regulation in the central nervous system functioning, we propose a possible implication of sweet taste receptor signaling in modulating cognitive functioning.
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Affiliation(s)
- Menizibeya O. Welcome
- World Scientific and Engineering Academy and Society, Ag. Ioannou Theologou 17-23, Zografou, 15773 Athens, Greece
| | - Nikos E. Mastorakis
- World Scientific and Engineering Academy and Society, Ag. Ioannou Theologou 17-23, Zografou, 15773 Athens, Greece
- Department of Industrial Engineering, Technical University of Sofia, 8 Kl. Ohridski Boulevard, 1000 Sofia, Bulgaria
| | - Vladimir A. Pereverzev
- Department of Normal Physiology, Belarusian State Medical University, Dzerzhinsky Avenue 83, 220116 Minsk, Belarus
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25
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Marin-Valencia I, Hooshyar MA, Pichumani K, Sherry AD, Malloy CR. The ratio of acetate-to-glucose oxidation in astrocytes from a single 13C NMR spectrum of cerebral cortex. J Neurochem 2014; 132:99-109. [PMID: 25231025 DOI: 10.1111/jnc.12948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 08/13/2014] [Accepted: 09/15/2014] [Indexed: 11/30/2022]
Abstract
The (13) C-labeling patterns in glutamate and glutamine from brain tissue are quite different after infusion of a mixture of (13) C-enriched glucose and acetate. Two processes contribute to this observation, oxidation of acetate by astrocytes but not neurons, and preferential incorporation of α-ketoglutarate into glutamate in neurons, and incorporation of α-ketoglutarate into glutamine in astrocytes. The acetate:glucose ratio, introduced previously for analysis of a single (13) C NMR spectrum, provides a useful index of acetate and glucose oxidation in the brain tissue. However, quantitation of relative substrate oxidation at the cell compartment level has not been reported. A simple mathematical method is presented to quantify the ratio of acetate-to-glucose oxidation in astrocytes, based on the standard assumption that neurons do not oxidize acetate. Mice were infused with [1,2-(13) C]acetate and [1,6-(13) C]glucose, and proton decoupled (13) C NMR spectra of cortex extracts were acquired. A fit of those spectra to the model indicated that (13) C-labeled acetate and glucose contributed approximately equally to acetyl-CoA (0.96) in astrocytes. As this method relies on a single (13) C NMR spectrum, it can be readily applied to multiple physiologic and pathologic conditions. Differences in (13) C labeling of brain glutamate and glutamine have been attributed to metabolic compartmentation. The acetate:glucose ratio, introduced for description of a (13) C NMR (nuclear magnetic resonance) spectrum, is an index of glucose and acetate oxidation in brain tissue. A simple mathematical method is presented to quantify the ratio of acetate-to-glucose oxidation in astrocytes from a single NMR spectrum. As kinetic analysis is not required, the method is readily applicable to analysis of tissue extracts. α-KG = alpha-ketoglutarate; CAC = citric acid cycle; GLN = glutamine; GLU = glutamate.
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Affiliation(s)
- Isaac Marin-Valencia
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA; Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA
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Brose SA, Marquardt AL, Golovko MY. Fatty acid biosynthesis from glutamate and glutamine is specifically induced in neuronal cells under hypoxia. J Neurochem 2013; 129:400-12. [PMID: 24266789 DOI: 10.1111/jnc.12617] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 10/27/2013] [Accepted: 11/14/2013] [Indexed: 12/12/2022]
Abstract
Hypoxia is involved in many neuronal and non-neuronal diseases, and defining the mechanisms for tissue adaptation to hypoxia is critical for the understanding and treatment of these diseases. One mechanism for tissue adaptation to hypoxia is increased glutamine and/or glutamate (Gln/Glu) utilization. To address this mechanism, we determined incorporation of Gln/Glu and other lipogenic substrates into lipids and fatty acids in both primary neurons and a neuronal cell line under normoxic and hypoxic conditions and compared this to non-neuronal primary cells and non-neuronal cell lines. Incorporation of Gln/Glu into total lipids was dramatically and specifically increased under hypoxia in neuronal cells including both primary (2.0- and 3.0-fold for Gln and Glu, respectively) and immortalized cultures (3.5- and 8.0-fold for Gln and Glu, respectively), and 90% to 97% of this increase was accounted for by incorporation into fatty acids (FA) depending upon substrate and cell type. All other non-neuronal cells tested demonstrated decreased or unchanged FA synthesis from Gln/Glu under hypoxia. Consistent with these data, total FA mass was also increased in neuronal cells under hypoxia that was mainly accounted for by the increase in saturated and monounsaturated FA with carbon length from 14 to 24. Incorporation of FA synthesized from Gln/Glu was increased in all major lipid classes including cholesteryl esters, triacylglycerols, diacylglycerols, free FA, and phospholipids, with the highest rate of incorporation into triacylglycerols. These results indicate that increased FA biosynthesis from Gln/Glu followed by esterification may be a neuronal specific pathway for adaptation to hypoxia. We identified a novel neuronal specific pathway for adaptation to hypoxia through increased fatty acid biosynthesis from glutamine and glutamate (Gln/Glu) followed by esterification into lipids. All other non-neuronal cells tested demonstrated decreased or unchanged lipid synthesis from Gln/Glu under hypoxia. Incorporation of other lipogenic substrates into lipids was decreased under hypoxia in neuronal cells. We believe that this finding will provide a novel strategy for treatment of oxygen and energy deficient conditions in the neuronal system.
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Affiliation(s)
- Stephen A Brose
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, Grand Forks, ND, USA
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27
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Bartnik-Olson BL, Harris NG, Shijo K, Sutton RL. Insights into the metabolic response to traumatic brain injury as revealed by (13)C NMR spectroscopy. FRONTIERS IN NEUROENERGETICS 2013; 5:8. [PMID: 24109452 PMCID: PMC3790078 DOI: 10.3389/fnene.2013.00008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/12/2013] [Indexed: 12/11/2022]
Abstract
The present review highlights critical issues related to cerebral metabolism following traumatic brain injury (TBI) and the use of (13)C labeled substrates and nuclear magnetic resonance (NMR) spectroscopy to study these changes. First we address some pathophysiologic factors contributing to metabolic dysfunction following TBI. We then examine how (13)C NMR spectroscopy strategies have been used to investigate energy metabolism, neurotransmission, the intracellular redox state, and neuroglial compartmentation following injury. (13)C NMR spectroscopy studies of brain extracts from animal models of TBI have revealed enhanced glycolytic production of lactate, evidence of pentose phosphate pathway (PPP) activation, and alterations in neuronal and astrocyte oxidative metabolism that are dependent on injury severity. Differential incorporation of label into glutamate and glutamine from (13)C labeled glucose or acetate also suggest TBI-induced adaptations to the glutamate-glutamine cycle.
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Jha S, Bhagwat A, Pandita N. Method development and validation of GABA using high-performance thin-layer chromatography in brain homogenate. JPC-J PLANAR CHROMAT 2013. [DOI: 10.1556/jpc.26.2013.5.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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29
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El Hage M, Baverel G, Conjard-Duplany A, Martin G. Effect of glucose on glutamine metabolism in rat brain slices: a cellular metabolomic study with Effect of glucose ¹³C NMR. Neuroscience 2013; 248:243-51. [PMID: 23769890 DOI: 10.1016/j.neuroscience.2013.05.064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/27/2013] [Accepted: 05/29/2013] [Indexed: 11/30/2022]
Abstract
To examine the effect of glucose on the cerebral metabolism of glutamine, rat brain slices were incubated with 5mM [3-(13)C]glutamine without and with 5mM unlabeled glucose. Tissue plus medium extracts were analyzed by using enzymatic and (13)C NMR techniques and fluxes through the enzymatic steps involved were calculated with a mathematical model. We demonstrate that glucose increased alanine, pyruvate and glutamate accumulations and decreased ammonium ions accumulation, aspartate accumulation and labeling, and GABA labeling. In order to determine the participation of glutamine synthetase when glucose was added to the incubation medium, we incubated rat brain slices with 5mM [3-(13)C]glutamine plus 5mM unlabeled glucose without and with 2mM methionine sulfoximine (MSO). The results indicate that 77% of the newly appeared glutamine was formed via glutamine synthetase and 23% from endogenous sources; the stimulation of [3-(13)C]glutamine removal by MSO also strongly suggests the existence of a cycle between [3-(13)C]glutamine and [3-(13)C]glutamate. This work also demonstrates that glucose increased fluxes through hexokinase, pyruvate kinase, lactate dehydrogenase, alanine aminotransferase, pyruvate carboxylase, pyruvate dehydrogenase, citrate synthase, flux from α-ketoglutarate to glutamate and flux through glutamine synthetase whereas it inhibited fluxes through aspartate aminotransferase, glutamic acid decarboxylase and GABA aminotransferase.
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Affiliation(s)
- M El Hage
- Metabolys Inc., Laennec Faculty of Medicine, 69372 Lyon Cedex 08, France.
| | - G Baverel
- Metabolys Inc., Laennec Faculty of Medicine, 69372 Lyon Cedex 08, France
| | - A Conjard-Duplany
- EA 4611, Biochimie et Physiopathologie Métaboliques, Laennec Faculty of Medicine, 69372 Lyon Cedex 08, France
| | - G Martin
- EA 4611, Biochimie et Physiopathologie Métaboliques, Laennec Faculty of Medicine, 69372 Lyon Cedex 08, France
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Stobart JL, Anderson CM. Multifunctional role of astrocytes as gatekeepers of neuronal energy supply. Front Cell Neurosci 2013; 7:38. [PMID: 23596393 PMCID: PMC3622037 DOI: 10.3389/fncel.2013.00038] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 03/26/2013] [Indexed: 01/01/2023] Open
Abstract
Dynamic adjustments to neuronal energy supply in response to synaptic activity are critical for neuronal function. Glial cells known as astrocytes have processes that ensheath most central synapses and express G-protein-coupled neurotransmitter receptors and transporters that respond to neuronal activity. Astrocytes also release substrates for neuronal oxidative phosphorylation and have processes that terminate on the surface of brain arterioles and can influence vascular smooth muscle tone and local blood flow. Membrane receptor or transporter-mediated effects of glutamate represent a convergence point of astrocyte influence on neuronal bioenergetics. Astrocytic glutamate uptake drives glycolysis and subsequent shuttling of lactate from astrocytes to neurons for oxidative metabolism. Astrocytes also convert synaptically reclaimed glutamate to glutamine, which is returned to neurons for glutamate salvage or oxidation. Finally, astrocytes store brain energy currency in the form of glycogen, which can be mobilized to produce lactate for neuronal oxidative phosphorylation in response to glutamatergic neurotransmission. These mechanisms couple synaptically driven astrocytic responses to glutamate with release of energy substrates back to neurons to match demand with supply. In addition, astrocytes directly influence the tone of penetrating brain arterioles in response to glutamatergic neurotransmission, coordinating dynamic regulation of local blood flow. We will describe the role of astrocytes in neurometabolic and neurovascular coupling in detail and discuss, in turn, how astrocyte dysfunction may contribute to neuronal bioenergetic deficit and neurodegeneration. Understanding the role of astrocytes as a hub for neurometabolic and neurovascular coupling mechanisms is a critical underpinning for therapeutic development in a broad range of neurodegenerative disorders characterized by chronic generalized brain ischemia and brain microvascular dysfunction.
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Affiliation(s)
- Jillian L Stobart
- Division of Neurodegenerative Disorders, Department of Pharmacology and Therapeutics, St. Boniface Hospital Research, University of Manitoba Winnipeg, MB, Canada ; Department of Nuclear Medicine, Institute of Pharmacology and Toxicology, University of Zürich Zürich, Switzerland
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31
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Dai S, Gao F, Xu X, Zhang W, Song S, Zhou G. Effects of dietary glutamine and gamma-aminobutyric acid on meat colour, pH, composition, and water-holding characteristic in broilers under cyclic heat stress. Br Poult Sci 2012; 53:471-81. [DOI: 10.1080/00071668.2012.719148] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- S.F. Dai
- a Key Laboratory of Meat Processing and Quality Control of Ministry of Education , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing 210095 , PR China
- b College of Animal Science, Anhui Science and Technology University , Fengyang 233100 , PR China
| | - F. Gao
- a Key Laboratory of Meat Processing and Quality Control of Ministry of Education , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing 210095 , PR China
| | - X.L. Xu
- a Key Laboratory of Meat Processing and Quality Control of Ministry of Education , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing 210095 , PR China
| | - W.H. Zhang
- a Key Laboratory of Meat Processing and Quality Control of Ministry of Education , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing 210095 , PR China
| | - S.X. Song
- a Key Laboratory of Meat Processing and Quality Control of Ministry of Education , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing 210095 , PR China
| | - G.H. Zhou
- a Key Laboratory of Meat Processing and Quality Control of Ministry of Education , College of Animal Science and Technology, Nanjing Agricultural University , Nanjing 210095 , PR China
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32
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Yang M, Wang S, Hao F, Li Y, Tang H, Shi X. NMR analysis of the rat neurochemical changes induced by middle cerebral artery occlusion. Talanta 2011; 88:136-44. [PMID: 22265479 DOI: 10.1016/j.talanta.2011.10.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/09/2011] [Accepted: 10/16/2011] [Indexed: 11/26/2022]
Abstract
Stroke is a leading cause of death and disability, affecting millions of people worldwide with almost 80% of them as ischemic stroke and understanding the multiple mechanisms underlying cerebral ischemia is essential for development of effective treatments. To understand metabolic changes induced by focal brain ischemia, we conducted a comparative analysis of metabolic composition of cerebral tissue from rats with sham-operation and middle cerebral artery occlusion (MCAO) using high-resolution nuclear magnetic resonance (NMR) spectroscopy. More than 40 metabolites were assigned including organic acids, amino acids, carbohydrates, choline, pyrimidine and purine metabolites. Our results showed that MCAO led to significant level decreases for glutamate, glutamine, aspartate, γ-aminobutyrate (GABA), taurine, malate, fumarate, acetate, phosphocreatine, and purine and pyrimidine metabolites such as inosine, hypoxanthine, xanthine, uracil and UDP/UTP, together with significant level increases for glucose in focal brain tissue extracts. This demonstrated that experimental ischemic stroke in rats caused extensive perturbation in tricarboxylic acid cycle, GABA shunt, and metabolisms of choline and nucleic acids. These findings provided essential information for our understandings of MCAO-caused biochemical alterations and demonstrated the metabolite composition analysis as a useful tool for understanding the neurochemistry of stroke.
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Affiliation(s)
- Mingxing Yang
- First Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China.
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33
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Effects of dietary glutamine and gamma-aminobutyric acid on performance, carcass characteristics and serum parameters in broilers under circular heat stress. Anim Feed Sci Technol 2011. [DOI: 10.1016/j.anifeedsci.2011.03.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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34
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Stelmashook EV, Isaev NK, Lozier ER, Goryacheva ES, Khaspekov LG. Role of Glutamine in Neuronal Survival and Death During Brain Ischemia and Hypoglycemia. Int J Neurosci 2011; 121:415-22. [DOI: 10.3109/00207454.2011.570464] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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35
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Saravana Babu C, Kesavanarayanan KS, Kalaivani P, Ranju V, Ramanathan M. A Simple Densitometric Method for the Quantification of Inhibitory Neurotransmitter Gamma-Aminobutyric Acid (GABA) in Rat Brain Tissue. ACTA ACUST UNITED AC 2011. [DOI: 10.4061/2011/732409] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian central nervous system which is involved in various physiological and pathological processes. The present study demonstrates a simple high-performance thin-layer chromatography (HPTLC) method which was developed for the estimation of GABA in rat brain tissue. The method was validated in terms of precision, recovery, reproducibility, and variability. Instrumental precision was found to be 0.5891% CV and reproducibility of the method was found to be 0.4141% CV. Interday and intraday precision of the method was found to be 0.9453% and 1.3236% CV, respectively. Accuracy of the method was checked by the recovery study, and the average recovery of GABA was found to be 97.98% at 40 ng and 96.15% at 80 ng levels. The present HPTLC method for GABA estimation was found to be simple, precise, reproducible, sensitive, and accurate. No doubt, this proposed method will be a useful tool for the estimation of GABA in rat brain tissue.
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Affiliation(s)
- Chidambaram Saravana Babu
- Centre for Toxicology and Developmental Research, Sri Ramachandra University, Chennai, TN-600 116, India
| | | | - Periyathambi Kalaivani
- Centre for Toxicology and Developmental Research, Sri Ramachandra University, Chennai, TN-600 116, India
| | - Vijayan Ranju
- Centre for Toxicology and Developmental Research, Sri Ramachandra University, Chennai, TN-600 116, India
| | - Muthiah Ramanathan
- PSG College of Pharmacy, Post Box No 1674, Peelamedu, Coimbatore, TN 641 004, India
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36
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El Hage M, Conjard-Duplany A, Baverel G, Martin G. Metabolic fate of a high concentration of glutamine and glutamate in rat brain slices: a ¹³C NMR study. Neurochem Int 2011; 58:896-903. [PMID: 21338644 DOI: 10.1016/j.neuint.2011.02.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 02/02/2011] [Accepted: 02/15/2011] [Indexed: 10/18/2022]
Abstract
This study was performed to analyze the metabolic fate of a high concentration (5 mM) of glutamine and glutamate in rat brain slices and the participation of these amino acids in the glutamine-glutamate cycle. For this, brain slices were incubated for 60 min with [3-¹³C]glutamine or [3-¹³C]glutamate. Tissue plus medium extracts were analyzed by enzymatic and ¹³C NMR measurements and fluxes through pathways of glutamine and glutamate metabolism were calculated. We demonstrate that both substrates were utilized and oxidized at high rates by rat brain slices and served as precursors of neurotransmitters, tricarboxylic acid (TCA) cycle intermediates and alanine. In order to determine the participation of glutamine synthetase in the appearance of new glutamine molecules with glutamine as substrate, brain slices were incubated with [3-¹³C]glutamine in the presence of methionine sulfoximine, a specific inhibitor of glutamine synthetase. Our results indicate that 36.5% of the new glutamine appeared was glutamine synthetase-dependent and 63.5% was formed from endogenous substrates. Flux through glutamic acid decarboxylase was higher with glutamine than with glutamate as substrate whereas fluxes from α-ketoglutarate to glutamate and through glutamine synthetase, malic enzyme, pyruvate dehydrogenase, pyruvate carboxylase and citrate synthase were in the same range with both substrates.
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Affiliation(s)
- Maha El Hage
- Institut National de la Santé et de la Recherche Médicale, Unit # 820 (Métabolomique et Maladies Métaboliques), 69372 Lyon Cedex 08, France.
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37
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Amaral AI, Teixeira AP, Sonnewald U, Alves PM. Estimation of intracellular fluxes in cerebellar neurons after hypoglycemia: Importance of the pyruvate recycling pathway and glutamine oxidation. J Neurosci Res 2011; 89:700-10. [DOI: 10.1002/jnr.22571] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 11/02/2010] [Accepted: 11/05/2010] [Indexed: 11/06/2022]
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38
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Glutamine-mediated protection from neuronal cell death depends on mitochondrial activity. Neurosci Lett 2010; 482:151-5. [DOI: 10.1016/j.neulet.2010.07.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 07/12/2010] [Accepted: 07/12/2010] [Indexed: 01/21/2023]
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Scafidi S, Fiskum G, Lindauer SL, Bamford P, Shi D, Hopkins I, McKenna MC. Metabolism of acetyl-L-carnitine for energy and neurotransmitter synthesis in the immature rat brain. J Neurochem 2010; 114:820-31. [PMID: 20477950 DOI: 10.1111/j.1471-4159.2010.06807.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Acetyl-L-carnitine (ALCAR) is an endogenous metabolic intermediate that facilitates the influx and efflux of acetyl groups across the mitochondrial inner membrane. Exogenously administered ALCAR has been used as a nutritional supplement and also as an experimental drug with reported neuroprotective properties and effects on brain metabolism. The aim of this study was to determine oxidative metabolism of ALCAR in the immature rat forebrain. Metabolism was studied in 21-22 day-old rat brain at 15, 60 and 120 min after an intraperitoneal injection of [2-(13)C]acetyl-L-carnitine. The amount, pattern, and fractional enrichment of (13)C-labeled metabolites were determined by ex vivo(13)C-NMR spectroscopy. Metabolism of the acetyl moiety from [2-(13)C]ALCAR via the tricarboxylic acid cycle led to incorporation of label into the C4, C3 and C2 positions of glutamate (GLU), glutamine (GLN) and GABA. Labeling patterns indicated that [2-(13)C]ALCAR was metabolized by both neurons and glia; however, the percent enrichment was higher in GLN and GABA than in GLU, demonstrating high metabolism in astrocytes and GABAergic neurons. Incorporation of label into the C3 position of alanine, both C3 and C2 positions of lactate, and the C1 and C5 positions of glutamate and glutamine demonstrated that [2-(13)C]ALCAR was actively metabolized via the pyruvate recycling pathway. The enrichment of metabolites with (13)C from metabolism of ALCAR was highest in alanine C3 (11%) and lactate C3 (10%), with considerable enrichment in GABA C4 (8%), GLN C3 (approximately 4%) and GLN C5 (5%). Overall, our (13)C-NMR studies reveal that the acetyl moiety of ALCAR is metabolized for energy in both astrocytes and neurons and the label incorporated into the neurotransmitters glutamate and GABA. Cycling ratios showed prolonged cycling of carbon from the acetyl moiety of ALCAR in the tricarboxylic acid cycle. Labeling of compounds formed from metabolism of [2-(13)C]ALCAR via the pyruvate recycling pathway was higher than values reported for other precursors and may reflect high activity of this pathway in the developing brain. This is, to our knowledge, the first study to determine the extent and pathways of ALCAR metabolism for energy and neurotransmitter biosynthesis in the brain.
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Affiliation(s)
- Susanna Scafidi
- Department of Pediatrics, University of Maryland, Baltimore, Maryland 21201, USA
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40
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Amaral AI, Teixeira AP, Martens S, Bernal V, Sousa MFQ, Alves PM. Metabolic alterations induced by ischemia in primary cultures of astrocytes: merging 13C NMR spectroscopy and metabolic flux analysis. J Neurochem 2010; 113:735-48. [PMID: 20141568 DOI: 10.1111/j.1471-4159.2010.06636.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Disruption of brain energy metabolism is the hallmark of cerebral ischemia, a major cause of death worldwide. Astrocytes play a key role in the regulation of brain metabolism and their vulnerability to ischemia has been described. Aiming to quantify the effects of an ischemic insult in astrocytic metabolism, primary cultures of astrocytes were subjected to 5 h of oxygen and glucose deprivation in a bioreactor. Flux distributions, before and after ischemia, were estimated by metabolic flux analysis using isotopic information and the consumption/secretion rates of relevant extracellular metabolites as constraints. During ischemia and early recovery, 30% of cell death was observed; several metabolic alterations were also identified reflecting a metabolic response by the surviving cells. In the early recovery ( approximately 10 h), astrocytes up-regulated glucose utilization by 30% and increased the pentose phosphate pathway and tricarboxylic acid cycle fluxes by three and twofold, respectively. Additionally, a two to fivefold enhancement in branched-chain amino acids catabolism suggested the importance of anaplerotic molecules to the fast recovery of the energetic state, which was corroborated by measured cellular ATP levels. Glycolytic metabolism was predominant in the late recovery. In summary, this work demonstrates that changes in fluxes of key metabolic pathways are implicated in the recovery from ischemia in astrocytes.
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Affiliation(s)
- Ana I Amaral
- Instituto de Tecnologia Química e Biológica - Universidade Nova de Lisboa, and Instituto de Biologia Experimental e Tecnológica, Oeiras, Portugal
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41
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Zielke HR, Zielke CL, Baab PJ. Direct measurement of oxidative metabolism in the living brain by microdialysis: a review. J Neurochem 2009; 109 Suppl 1:24-9. [PMID: 19393005 DOI: 10.1111/j.1471-4159.2009.05941.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
This review summarizes microdialysis studies that address the question of which compounds serve as energy sources in the brain. Microdialysis was used to introduce 14C-labeled glucose, lactate, pyruvate, glutamate, glutamine, and acetate into the interstitial fluid of the brain to observe their metabolism to 14CO2. Although glucose uptake from the systemic system supplies the carbon source for these compounds, compounds synthesized from glucose by the brain are subject to recycling including complete metabolism to CO2. Therefore, the brain utilizes multiple compounds in its domain to provide the energy needed to fulfill its function. The physiological conditions controlling metabolism and the contribution of compartmentation into different brain regions, cell types, and subcellular spaces are still unresolved. The aconitase inhibitor fluorocitrate, with a lower inhibition threshold in glial cells, was used to identify the proportion of lactate and glucose that was oxidized in glial cells versus neurons. The fluorocitrate data suggest that glial and neuronal cells are capable of utilizing both lactate and glucose for energy metabolism.
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Affiliation(s)
- H Ronald Zielke
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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42
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Håberg AK, Qu H, Sonnewald U. Acute changes in intermediary metabolism in cerebellum and contralateral hemisphere following middle cerebral artery occlusion in rat. J Neurochem 2009; 109 Suppl 1:174-81. [DOI: 10.1111/j.1471-4159.2009.05940.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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43
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Pre-ischemic treadmill training affects glutamate and gamma aminobutyric acid levels in the striatal dialysate of a rat model of cerebral ischemia. Life Sci 2009; 84:505-11. [DOI: 10.1016/j.lfs.2009.01.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 12/05/2008] [Accepted: 01/26/2009] [Indexed: 11/17/2022]
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44
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Hertz L. Bioenergetics of cerebral ischemia: a cellular perspective. Neuropharmacology 2008; 55:289-309. [PMID: 18639906 DOI: 10.1016/j.neuropharm.2008.05.023] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 05/14/2008] [Accepted: 05/14/2008] [Indexed: 12/27/2022]
Abstract
In cerebral ischemia survival of neurons, astrocytes, oligodendrocytes and endothelial cells is threatened during energy deprivation and/or following re-supply of oxygen and glucose. After a brief summary of characteristics of different cells types, emphasizing the dependence of all on oxidative metabolism, the bioenergetics of focal and global ischemia is discussed, distinguishing between events during energy deprivation and subsequent recovery attempt after re-circulation. Gray and white matter ischemia are described separately, and distinctions are made between mature and immature brains. Next comes a description of bioenergetics in individual cell types in culture during oxygen/glucose deprivation or exposure to metabolic inhibitors and following re-establishment of normal aerated conditions. Due to their expression of NMDA and non-NMDA receptors neurons and oligodendrocytes are exquisitely sensitive to excitotoxicity by glutamate, which reaches high extracellular concentrations in ischemic brain for several reasons, including failing astrocytic uptake. Excitotoxicity kills brain cells by energetic exhaustion (due to Na(+) extrusion after channel-mediated entry) combined with mitochondrial Ca(2+)-mediated injury and formation of reactive oxygen species. Many (but not all) astrocytes survive energy deprivation for extended periods, but after return to aerated conditions they are vulnerable to mitochondrial damage by cytoplasmic/mitochondrial Ca(2+) overload and to NAD(+) deficiency. Ca(2+) overload is established by reversal of Na(+)/Ca(2+) exchangers following Na(+) accumulation during Na(+)-K(+)-Cl(-) cotransporter stimulation or pH regulation, compensating for excessive acid production. NAD(+) deficiency inhibits glycolysis and eventually oxidative metabolism, secondary to poly(ADP-ribose)polymerase (PARP) activity following DNA damage. Hyperglycemia can be beneficial for neurons but increases astrocytic death due to enhanced acidosis.
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Affiliation(s)
- Leif Hertz
- College of Basic Medical Sciences, China Medical University, Shenyang, PR China.
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Rodrigues TB, Granado N, Ortiz O, Cerdán S, Moratalla R. Metabolic interactions between glutamatergic and dopaminergic neurotransmitter systems are mediated through D(1) dopamine receptors. J Neurosci Res 2008; 85:3284-93. [PMID: 17455302 DOI: 10.1002/jnr.21302] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Interactions between the dopaminergic and glutamatergic neurotransmission systems were investigated in the adult brain of wild-type (WT) and transgenic mice lacking the dopamine D(1) or D(2) receptor subtypes. Activity of the glutamine cycle was evaluated by using (13)C NMR spectroscopy, and striatal activity was assessed by c-Fos expression and motor coordination. Brain extracts from (1,2-(13)C(2)) acetate-infused mice were prepared and analyzed by (13)C NMR to determine the incorporation of the label into the C4 and C5 carbons of glutamate and glutamine. D(1)R(-/-) mice showed a significantly higher concentration of cerebral (4,5-(13)C(2)) glutamine, consistent with an increased activity of the glutamate-glutamine cycle and of glutamatergic neurotransmission. Conversely, D(2)R(-/-) mice did not show any significant changes in (4,5-(13)C(2)) glutamate or (4,5-(13)C(2)) glutamine, suggesting that alterations in glutamine metabolism are mediated through D(1) receptors. This was confirmed with D(1)R(-/-) and WT mice treated with reserpine, a dopamine-depleting drug, or with reserpine followed by L-DOPA, a dopamine precursor. Exposure to reserpine increased (4,5-(13)C(2)) glutamine in WT to levels similar to those found in untreated D(1)R(-/-) mice. These values were the same as those reached in the reserpine-treated D(1)R(-/-) mice. Treatment of WT animals with L-DOPA returned (4,5-(13)C(2)) glutamine levels to normal, but this was not verified in D(1)R(-/-) animals. Reserpine impaired motor coordination and decreased c-Fos expression, whereas L-DOPA restored both variables to normal values in WT but not in D(1)R(-/-). Together, our results reveal novel neurometabolic interactions between glutamatergic and dopaminergic systems that are mediated through the D(1), but not the D(2), dopamine receptor subtype.
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Affiliation(s)
- Tiago B Rodrigues
- Instituto de Investigaciones Biomédicas Alberto Sols, CSIC/UAM, Madrid, Spain
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van der Zijden JP, van Eijsden P, de Graaf RA, Dijkhuizen RM. 1H/13C MR spectroscopic imaging of regionally specific metabolic alterations after experimental stroke. Brain 2008; 131:2209-19. [DOI: 10.1093/brain/awn139] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sun D, Vingrys AJ, Kalloniatis M. Metabolic and functional profiling of the ischemic/reperfused rat retina. J Comp Neurol 2008; 505:114-30. [PMID: 17729266 DOI: 10.1002/cne.21481] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We quantitatively tracked the recovery in amino acid labeling and cation channel functionality within distinct retinal elements for up to 2 weeks after an ischemic insult. Pattern recognition analysis of multiple amino acid and agmatine (a cation channel probe; 1-amino-4-guanidobutane; AGB) immunocytochemical patterns was used to classify all neural elements within the retina. This classification was spatially complete and with single-cell resolution. By 48 hours of reperfusion the amino acid labeling pattern of virtually all cell populations had returned to near preischemic levels, with the exception of glutamine and alanine levels, which remained significantly higher in many cell populations. Classification resulted in a total of 18 statistically separable theme classes (including neurons, glia, and extraretinal classes), a reduction of 10 theme classes from the normal retina (Sun et al. [ 2007a, b] J Comp Neurol, this issue). In addition to the known selective losses of amacrine cell types within the inner nuclear layer, we now demonstrate a selective loss of theme classes representing cone bipolar cells within the bipolar cell population. While there was a recovery in the amino acid labeling pattern, there were persistent cation channel gating anomalies (as reflected by AGB labeling) within several theme classes, including the theme class representing all the remaining rod bipolar cells, suggesting aberrant neuronal function secondary to metabolic insult.
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Affiliation(s)
- Daniel Sun
- Department of Optometry and Vision Science, University of Auckland, New Zealand
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Peng L, Gu L, Zhang H, Huang X, Hertz E, Hertz L. Glutamine as an energy substrate in cultured neurons during glucose deprivation. J Neurosci Res 2007; 85:3480-6. [PMID: 17410598 DOI: 10.1002/jnr.21262] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
During glucose deprivation an increase in aspartate formation from glutamine has been observed in different brain preparations, including synaptosomes and cultured astrocytes. To what extent this reaction, which provides a substantial amount of energy, occurs in different types of neurons is unknown. The present study shows that (14)CO(2) formation from [U-(14)C]glutamine in cerebellar granule neurons, a glutamatergic preparation, increased by 60% during glucose deprivation, indicating enhanced aspartate formation or increased complete oxidative degradation of glutamine. In primary cultures of cerebrocortical interneurons, a GABAergic preparation, the rate of (14)CO(2) production from [U-(14) C] glutamine was four times lower and not stimulated by glucose deprivation. During incubation with glutamine (0.8 mM) as the only metabolic substrate, cerebellar granule cells maintained an oxygen consumption rate of 12 nmol/min/mg protein, corresponding to an aspartate formation of 8 nmol/min/mg protein (three oxidations occur between glutamine and aspartate) or to a total oxidative degradation of 3 nmol/min/mg protein. During glucose deprivation, the rate of aspartate formation increased, and during a 20-min incubation in phosphate-buffered saline it amounted to 3.3 nmol/min/mg protein at 0.2 mM glutamine, which might have been more if measured at 0.8 mM glutamine. These values are consistent with the rate of glutamine utilization calculated based on oxygen consumption and leaves open the possibility that some glutamine is completely degraded oxidatively, as has been shown by other authors based on pyruvate recycling and labeling of lactate from aspartate in cerebellar granule neurons.
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Affiliation(s)
- Liang Peng
- Department of Clinical Pharmacology, China Medical University, Shenyang, China
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Pascual JM, Solivera J, Prieto R, Barrios L, López-Larrubia P, Cerdán S, Roda JM. Time Course of Early Metabolic Changes following Diffuse Traumatic Brain Injury in Rats as Detected by1H NMR Spectroscopy. J Neurotrauma 2007; 24:944-59. [PMID: 17600512 DOI: 10.1089/neu.2006.0190] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Experimental models of traumatic brain injury (TBI) provide a useful tool for understanding the cerebral metabolic changes induced by this pathological condition. Here, we report on the time course of changes in cerebral metabolites after TBI and its correlation with early brain morphological changes using a combination of high-resolution proton magnetic resonance spectroscopy ((1)H MRS) and magnetic resonance imaging (MRI). Adult male Sprague-Dawley rats were subjected to closed head impact and examined by MRI at 1, 9, 24, 48, and and 72 h after the injury. Extracts from funnel frozen rat brains were then obtained and analyzed quantitatively by high-resolution (1)H MRS. Finally, statistical multivariate analysis was carried out to identify the combination of cerebral metabolites that best described the time evolution of diffuse TBI. The temporal changes observed in the concentration of cerebral metabolites followed three different patterns. The first pattern included taurine, threonine, and glycine, with concentrations peaking 24 h after the injury. The second pattern included glutamate, GABA, and alanine, with concentrations remaining elevated between 24 and 48 h post-injury. The third one involved creatine-phosphocreatine, N-acetylaspartate, and myo-inositol, with concentrations peaking 48 h after the injury. A multivariate stepwise discriminant analysis revealed that the combination of the organic osmolytes taurine and myo-inositol allowed optimal discrimination among the different time groups. Our findings suggest that the profile of some specific brain molecules that play a role as organic osmolytes can be used to follow-up the progression of the early diffuse brain edema response induced by TBI.
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Affiliation(s)
- José M Pascual
- Department of Neurosurgery, La Princesa University Hospital, Madrid, Spain.
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50
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Richards EM, Fiskum G, Rosenthal RE, Hopkins I, McKenna MC. Hyperoxic reperfusion after global ischemia decreases hippocampal energy metabolism. Stroke 2007; 38:1578-84. [PMID: 17413048 PMCID: PMC2601708 DOI: 10.1161/strokeaha.106.473967] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND PURPOSE Previous reports indicate that compared with normoxia, 100% ventilatory O(2) during early reperfusion after global cerebral ischemia decreases hippocampal pyruvate dehydrogenase activity and increases neuronal death. However, current standards of care after cardiac arrest encourage the use of 100% O(2) during resuscitation and for an undefined period thereafter. Using a clinically relevant canine cardiac arrest model, in this study we tested the hypothesis that hyperoxic reperfusion decreases hippocampal glucose metabolism and glutamate synthesis. METHODS After 10 minutes of cardiac arrest, animals were resuscitated and ventilated for 1 hour with 100% O(2) (hyperoxic) or 21% to 30% O(2) (normoxic). At 30 minutes reperfusion, [1-(13)C]glucose was infused, and at 2 hours, brains were rapidly removed and frozen. Extracted metabolites were analyzed by (13)C nuclear magnetic resonance spectroscopy. RESULTS Compared with nonischemic controls, the hippocampi from hyperoxic animals had elevated levels of unmetabolized (13)C-glucose and decreased incorporation of (13)C into all isotope isomers of glutamate. These findings indicate impaired neuronal metabolism via the pyruvate dehydrogenase pathway for carbon entry into the tricarboxylic acid cycle and impaired glucose metabolism via the astrocytic pyruvate carboxylase pathway. No differences were observed in the cortex, indicating that the hippocampus is more vulnerable to metabolic changes induced by hyperoxic reperfusion. CONCLUSIONS These results represent the first direct evidence that hyperoxia after cardiac arrest impairs hippocampal oxidative energy metabolism in the brain and challenge the rationale for using excessively high resuscitative ventilatory O(2).
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Affiliation(s)
- Erica M Richards
- Program in Neuroscience, the Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, USA
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