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Li K, Zheng Y, Wang X. Self-Regulation of Cerebral Metabolism and Its Neuroprotective Effect After Hypoxic-Ischemic Injury: Evidence From 1H-MRS. Front Neuroanat 2021; 15:672412. [PMID: 34220456 PMCID: PMC8247914 DOI: 10.3389/fnana.2021.672412] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/24/2021] [Indexed: 12/27/2022] Open
Abstract
1H-MRS technology can be used to non-invasively detect the content of cerebral metabolites, to assess the severity of hypoxic-ischemic (HI) injury, and to predict the recovery of compromised neurological function. However, changes to the cerebral self-regulation process after HI are still unclear. This study investigated the changes in cerebral metabolites and the potential relationship with the number of neurons and neural stem/progenitor cells (NSPC) using 1H-MRS, and finally clarifies the self-regulation of cerebral metabolism and neuroprotection after HI injury. Newborn Yorkshire pigs (28 males, 1.0–1.5 kg) aged 3–5 days were used for the HI model in this study. The pigs were randomly divided into the HI group (n = 24) and the control group (n = 4), then the experimental group was subdivided according to different recovery time after HI into the following groups: 0–2 h (n = 4), 2–6 h (n = 4), 6–12 h (n = 4), 12–24 h (n = 4), 24–48 h (n = 4), and 48–72 h (n = 4). Following the HI timepoints, 1H-MRS scans were performed and processed using LCModel software, and brain tissue was immunohistochemically stained for Nestin and NeuN. Immunofluorescence staining of creatine phosphokinase-BB (CK-BB), N-acetylaspartylglutamate synthetase (NAAGS), glutamate carboxypeptidase II (GCP-II), glutamate-cysteine ligase catalytic subunit (GCLC), glutathione synthase (GS), and excitatory amino acid carrier 1 (EAAC1) was then performed. The 1H-MRS results showed that cerebral N-acetylaspartylglutamate (NAAG), glutathione (GSH), and creatine (Cr) content reached their peaks at 12–24 h, which was consistent with the recovery time of hippocampal NSPCs and neurons, indicating a potential neuroprotective effect of NAAG, GSH, and Cr after HI injury.
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Affiliation(s)
- Kexin Li
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yang Zheng
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiaoming Wang
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, China
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Zhang S, Lachance BB, Mattson MP, Jia X. Glucose metabolic crosstalk and regulation in brain function and diseases. Prog Neurobiol 2021; 204:102089. [PMID: 34118354 DOI: 10.1016/j.pneurobio.2021.102089] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 04/08/2021] [Accepted: 06/01/2021] [Indexed: 01/11/2023]
Abstract
Brain glucose metabolism, including glycolysis, the pentose phosphate pathway, and glycogen turnover, produces ATP for energetic support and provides the precursors for the synthesis of biological macromolecules. Although glucose metabolism in neurons and astrocytes has been extensively studied, the glucose metabolism of microglia and oligodendrocytes, and their interactions with neurons and astrocytes, remain critical to understand brain function. Brain regions with heterogeneous cell composition and cell-type-specific profiles of glucose metabolism suggest that metabolic networks within the brain are complex. Signal transduction proteins including those in the Wnt, GSK-3β, PI3K-AKT, and AMPK pathways are involved in regulating these networks. Additionally, glycolytic enzymes and metabolites, such as hexokinase 2, acetyl-CoA, and enolase 2, are implicated in the modulation of cellular function, microglial activation, glycation, and acetylation of biomolecules. Given these extensive networks, glucose metabolism dysfunction in the whole brain or specific cell types is strongly associated with neurologic pathology including ischemic brain injury and neurodegenerative disorders. This review characterizes the glucose metabolism networks of the brain based on molecular signaling and cellular and regional interactions, and elucidates glucose metabolism-based mechanisms of neurological diseases and therapeutic approaches that may ameliorate metabolic abnormalities in those diseases.
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Affiliation(s)
- Shuai Zhang
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, 21201, United States
| | - Brittany Bolduc Lachance
- Program in Trauma, Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States
| | - Mark P Mattson
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States
| | - Xiaofeng Jia
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, MD, 21201, United States; Department of Orthopedics, University of Maryland School of Medicine, Baltimore, MD, 21201, United States; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, 21201, United States; Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States; Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States.
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Soto‐Heredero G, Gómez de las Heras MM, Gabandé‐Rodríguez E, Oller J, Mittelbrunn M. Glycolysis - a key player in the inflammatory response. FEBS J 2020; 287:3350-3369. [PMID: 32255251 PMCID: PMC7496292 DOI: 10.1111/febs.15327] [Citation(s) in RCA: 254] [Impact Index Per Article: 63.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/06/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
The inflammatory response involves the activation of several cell types to fight insults caused by a plethora of agents, and to maintain the tissue homoeostasis. On the one hand, cells involved in the pro-inflammatory response, such as inflammatory M1 macrophages, Th1 and Th17 lymphocytes or activated microglia, must rapidly provide energy to fuel inflammation, which is essentially accomplished by glycolysis and high lactate production. On the other hand, regulatory T cells or M2 macrophages, which are involved in immune regulation and resolution of inflammation, preferentially use fatty acid oxidation through the TCA cycle as a main source for energy production. Here, we discuss the impact of glycolytic metabolism at the different steps of the inflammatory response. Finally, we review a wide variety of molecular mechanisms which could explain the relationship between glycolytic metabolites and the pro-inflammatory phenotype, including signalling events, epigenetic remodelling, post-transcriptional regulation and post-translational modifications. Inflammatory processes are a common feature of many age-associated diseases, such as cardiovascular and neurodegenerative disorders. The finding that immunometabolism could be a master regulator of inflammation broadens the avenue for treating inflammation-related pathologies through the manipulation of the vascular and immune cell metabolism.
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Affiliation(s)
- Gonzalo Soto‐Heredero
- Immunometabolism and Inflammation LaboratoryCellular Communication & Inflammation UnitCentro de Biología Molecular Severo OchoaMadridSpain
- Department of Molecular BiologyFaculty of SciencesUniversidad Autónoma de Madrid (UAM)Spain
- Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12)MadridSpain
| | - Manuel M. Gómez de las Heras
- Immunometabolism and Inflammation LaboratoryCellular Communication & Inflammation UnitCentro de Biología Molecular Severo OchoaMadridSpain
- Department of Molecular BiologyFaculty of SciencesUniversidad Autónoma de Madrid (UAM)Spain
| | - Enrique Gabandé‐Rodríguez
- Immunometabolism and Inflammation LaboratoryCellular Communication & Inflammation UnitCentro de Biología Molecular Severo OchoaMadridSpain
- Department of Molecular BiologyFaculty of SciencesUniversidad Autónoma de Madrid (UAM)Spain
- Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12)MadridSpain
| | - Jorge Oller
- Immunometabolism and Inflammation LaboratoryCellular Communication & Inflammation UnitCentro de Biología Molecular Severo OchoaMadridSpain
- Department of Molecular BiologyFaculty of SciencesUniversidad Autónoma de Madrid (UAM)Spain
- Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12)MadridSpain
| | - María Mittelbrunn
- Immunometabolism and Inflammation LaboratoryCellular Communication & Inflammation UnitCentro de Biología Molecular Severo OchoaMadridSpain
- Department of Molecular BiologyFaculty of SciencesUniversidad Autónoma de Madrid (UAM)Spain
- Instituto de Investigación Sanitaria Hospital 12 de Octubre (imas12)MadridSpain
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Rana P, Rama Rao KV, Ravula A, Trivedi R, D'Souza M, Singh AK, Gupta RK, Chandra N. Oxidative stress contributes to cerebral metabolomic profile changes in animal model of blast-induced traumatic brain injury. Metabolomics 2020; 16:39. [PMID: 32166461 DOI: 10.1007/s11306-020-1649-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 02/02/2020] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Blast-induced neurotrauma (BINT) has been recognized as the common mode of traumatic brain injury amongst military and civilian personnel due to an increased insurgent activity domestically and abroad. Previous studies from this laboratory have identified three major pathological events following BINT which include blood brain barrier disruption the earliest event, followed by oxidative stress and neuroinflammation as secondary events occurring a few hours following blast. OBJECTIVES Our recent studies have also identified an increase in oxidative stress mediated by the activation of superoxide producing enzyme NADPH oxidase (NOX) in different brain regions at varying levels with neurons displaying higher oxidative stress (NOX activation) compared to any other neural cell. Since neurons have higher energy demands in brain and are more prone to oxidative damage, this study evaluated the effect of oxidative stress on blast-blast induced changes in metabolomics profiles in different brain regions. METHODS Animals were exposed to mild/moderate blast injury (180 kPa) and examined the metabolites of energy metabolism, amino acid metabolism as well as the profiles of plasma membrane metabolites in different brain regions at different time points (24 h, 3 day and 7 day) after blast using 1H NMR spectroscopy. Effect of apocynin, an inhibitor of superoxide producing enzyme NADPH oxidase on cerebral metabalomics profiles was also examined. RESULTS Several metabolomic profile changes were observed in frontal cortex and hippocampus with concomitant decrease in energy metabolism. In addition, glutamate/glutamine and other amino acid metabolism as well as metabolites involved in plasma membrane integrity were also altered. Hippocampus appears metabolically more vulnerable than the frontal cortex. A post-treatment of animals with apocynin, an inhibitor of NOX activation significantly prevented the changes in metabolite profiles. CONCLUSION Together these studies indicate that blast injury reduces both cerebral energy and neurotransmitter amino acid metabolism and that oxidative stress contributes to these processes. Thus, strategies aimed at reducing oxidative stress can have a therapeutic benefit in mitigating metabolic changes following BINT.
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Affiliation(s)
- Poonam Rana
- Metabolomics Research Facility, Division of Behavioral Neuroscience, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Kakulavarapu V Rama Rao
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA
| | - Arunreddy Ravula
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA
| | - Richa Trivedi
- Metabolomics Research Facility, Division of Behavioral Neuroscience, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Maria D'Souza
- Department of NMR, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Ajay K Singh
- Metabolomics Research Facility, Division of Behavioral Neuroscience, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Raj K Gupta
- US Department of Defense Blast Injury Research Program Coordinating Office, US Army MRMC, 504 Scott Street, Fort Detrick, MD, USA.
| | - Namas Chandra
- US Department of Defense Blast Injury Research Program Coordinating Office, US Army MRMC, 504 Scott Street, Fort Detrick, MD, USA.
- Center for Injury Biomechanics, Materials and Medicine (CIBM3), Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102-1982, USA.
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Kadri S, El Ayed M, Cosette P, Jouenne T, Elkhaoui S, Zekri S, Limam F, Aouani E, Mokni M. Neuroprotective effect of grape seed extract on brain ischemia: a proteomic approach. Metab Brain Dis 2019; 34:889-907. [PMID: 30796716 DOI: 10.1007/s11011-019-00396-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/04/2019] [Indexed: 01/01/2023]
Abstract
Stroke is one of the leading causes of long-lasting disability in human and oxidative stress an important underlying cause. Molecular insights into pathophysiology of ischemic stroke are still obscure, and the present study investigated the protective effect of high dosage Grape Seed Extract (GSE 2.5 g/kg) on brain ischemia-reperfusion (I/R) injury using a proteomic approach. Ischemia was realized by occlusion of the common carotid arteries for 30 min followed by 1 h reperfusion on control or GSE pre-treated rats, and a label-free quantification followed by mass spectrometry analysis used to evaluate I/R induced alterations in protein abundance and metabolic pathways as well as the protection afforded by GSE. I/R-induced whole brain ionogram dyshomeostasis, ultrastructural alterations, as well as inflammation into hippocampal dentate gyrus area, which were evaluated using ICP-OES, transmission electron microscopy and immuno-histochemistry respectively. I/R altered the whole brain proteome abundance among which 108 proteins were significantly modified (35 up and 73 down-regulated proteins). Eighty-four proteins were protected upon GSE treatment among which 27 were up and 57 down-regulated proteins, suggesting a potent protective effect of GSE close to 78%of the disturbed proteome. Furthermore, GSE efficiently prevented the brain from I/R-induced ion dyshomeostasis, ultrastructural alterations, inflammatory biomarkers as CD56 or CD68 and calcium burst within the hippocampus. To conclude, a potent protective effect of GSE on brain ischemia is evidenced and clinical trials using high dosage GSE should be envisaged on people at high risk for stroke.
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Affiliation(s)
- Safwen Kadri
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia.
| | - Mohamed El Ayed
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Pascal Cosette
- Plateforme Protéomique PISSARO, Institut de Recherche et d'Innovation Biomédicale, Normandie Université, Mont Saint Aignan, France
| | - Thierry Jouenne
- Plateforme Protéomique PISSARO, Institut de Recherche et d'Innovation Biomédicale, Normandie Université, Mont Saint Aignan, France
| | - Salem Elkhaoui
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Sami Zekri
- Common Services Unit on Transmission Electron Microscopy, Faculty of Medicineof Tunis, University of Tunis El Manar, Bab Saâdoun, Tunis, Tunisia
| | - Ferid Limam
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Ezzedine Aouani
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
| | - Meherzia Mokni
- Bioactive Substances Laboratory, Biotechnology Centre, TechnopolisBorj-Cedria, BP-901, 2050, Hammam-Lif, Tunis, Tunisia
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Oligodendrocytes: Development, Physiology and Glucose Metabolism. ADVANCES IN NEUROBIOLOGY 2018; 13:275-294. [PMID: 27885633 DOI: 10.1007/978-3-319-45096-4_10] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The glutamate-glutamine cycle is an outstanding example of how essential neuronal-glial interactions are for brain function. For several decades, this and other metabolic cycles in the brain have only included neurons and astrocytes but not oligodendrocytes, the myelinating cells of the central nervous system (CNS). Recent data revealed that oligodendrocytes are highly metabolically active cells in the brain and, therefore, should not be ignored. Using 13C-labelled glucose in combination with nuclear magnetic resonance spectroscopy (MRS) and/or mass spectrometry (MS) it is possible to characterize metabolic functions in primary oligodendrocyte cultures. Mature rat oligodendrocytes avidly metabolize glucose in the cytosol and pyruvate derived from glucose in mitochondria. Moreover, they seem to have the ability of performing anaplerosis from pyruvate, which might enable them to synthesize metabolites de novo and transfer them to neighbouring cells. All these original findings highlight the importance of investigating oligodendrocyte metabolism separately from that of astrocytes and neurons to be able to discern the roles played by the individual partners. This is of particular importance in the white matter where the number of oligodendrocytes is considerable. The present book chapter provides some background on oligodendrocyte biology and physiology and summarizes the not very extensive information published on glucose metabolism in oligodendrocytes.
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7
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Zheng Y, Wang XM. Expression Changes in Lactate and Glucose Metabolism and Associated Transporters in Basal Ganglia following Hypoxic-Ischemic Reperfusion Injury in Piglets. AJNR Am J Neuroradiol 2018; 39:569-576. [PMID: 29326137 DOI: 10.3174/ajnr.a5505] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 10/30/2017] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE The neonatal brain has active energy metabolism, and glucose oxidation is the major energy source of brain tissue. Lactate is produced by astrocytes and released to neurons. In the central nervous system, lactate is transported between neurons and astrocytes via the astrocyte-neuron lactate shuttle. The aim of this study was to investigate the regulatory mechanisms of energy metabolism in neurons and astrocytes in the basal ganglia of a neonatal hypoxic-ischemic brain injury piglet model. MATERIALS AND METHODS A total of 35 healthy piglets (3-5 days of age; 1.0-1.5 kg) were assigned to a control group (n = 5) or a hypoxic-ischemic model group (n = 30). The hypoxic-ischemic model group was further divided into 6 groups according to the 1H-MR spectroscopy and PET/CT scan times after hypoxia-ischemia (0-2, 2-6, 6-12, 12-24, 24-48, and 48-72 hours; n = 5/group). 1H-MR spectroscopy data were processed with LCModel software. Maximum standard uptake values refer to the maximum standard uptake values for glucose (or FDG). The maximum standard uptake values of the basal ganglia-to-occipital cortex ratio were analyzed. The expression levels of glucose transporters and monocarboxylate transporters were detected by immunohistochemical analysis. RESULTS Lactate levels decreased after an initial increase, with the maximal level occurring around 2-6 hours following hypoxia-ischemia. After hypoxia-ischemia, the maximum standard uptake values of the basal ganglia and basal ganglia/occipital cortex initially increased then decreased, with the maximum occurring at approximately 6-12 hours. The lactate and glucose uptake (basal ganglia/occipital cortex maximum standard uptake values) levels were positively correlated. The expression levels of glucose transporter-1 and glucose transporter-3 were positively correlated with the basal ganglia/occipital cortex. The expression levels of monocarboxylic acid transporter-2 and monocarboxylic acid transporter-4 were positively correlated with lactate content. CONCLUSIONS The results indicate that lactate and glucose transporters have a synergistic effect on the energy metabolism of neurons and astrocytes following hypoxic-ischemic reperfusion brain injury.
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Affiliation(s)
- Y Zheng
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China
| | - X-M Wang
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China.
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Use of CellNetAnalyzer in biotechnology and metabolic engineering. J Biotechnol 2017; 261:221-228. [DOI: 10.1016/j.jbiotec.2017.05.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/28/2017] [Accepted: 05/03/2017] [Indexed: 01/28/2023]
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The Applicability of Amide Proton Transfer Imaging in the Nervous System: Focus on Hypoxic-Ischemic Encephalopathy in the Neonate. Cell Mol Neurobiol 2017; 38:797-807. [DOI: 10.1007/s10571-017-0552-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 09/16/2017] [Indexed: 12/29/2022]
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10
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Liu S, Dai Q, Hua R, Liu T, Han S, Li S, Li J. Determination of Brain-Regional Blood Perfusion and Endogenous cPKCγ Impact on Ischemic Vulnerability of Mice with Global Ischemia. Neurochem Res 2017; 42:2814-2825. [DOI: 10.1007/s11064-017-2294-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 04/19/2017] [Accepted: 05/06/2017] [Indexed: 01/12/2023]
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Zheng Y, Wang XM. Measurement of Lactate Content and Amide Proton Transfer Values in the Basal Ganglia of a Neonatal Piglet Hypoxic-Ischemic Brain Injury Model Using MRI. AJNR Am J Neuroradiol 2017; 38:827-834. [PMID: 28154122 DOI: 10.3174/ajnr.a5066] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 11/06/2016] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE As amide proton transfer imaging is sensitive to protein content and intracellular pH, it has been widely used in the nervous system, including brain tumors and stroke. This work aimed to measure the lactate content and amide proton transfer values in the basal ganglia of a neonatal piglet hypoxic-ischemic brain injury model by using MR spectroscopy and amide proton transfer imaging. MATERIALS AND METHODS From 58 healthy neonatal piglets (3-5 days after birth; weight, 1-1.5 kg) selected initially, 9 piglets remained in the control group and 43 piglets, in the hypoxic-ischemic brain injury group. Single-section amide proton transfer imaging was performed at the coronal level of the basal ganglia. Amide proton transfer values of the bilateral basal ganglia were measured in all piglets. The ROI of MR spectroscopy imaging was the right basal ganglia, and the postprocessing was completed with LCModel software. RESULTS After hypoxic-ischemic insult, the amide proton transfer values immediately decreased, and at 0-2 hours, they remained at their lowest level. Thereafter, they gradually increased and finally exceeded those of the control group at 48-72 hours. After hypoxic-ischemic insult, the lactate content increased immediately, was maximal at 2-6 hours, and then gradually decreased to the level of the control group. The amide proton transfer values were negatively correlated with lactate content (r = -0.79, P < .05). CONCLUSIONS This observation suggests that after hypoxic-ischemic insult, the recovery of pH was faster than that of lactate homeostasis.
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Affiliation(s)
- Y Zheng
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China
| | - X-M Wang
- From the Department of Radiology, Shengjing Hospital of China Medical University, Shenyang, PR China.
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Functional metabolic interactions of human neuron-astrocyte 3D in vitro networks. Sci Rep 2016; 6:33285. [PMID: 27619889 PMCID: PMC5020407 DOI: 10.1038/srep33285] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 08/19/2016] [Indexed: 01/27/2023] Open
Abstract
The generation of human neural tissue-like 3D structures holds great promise for disease modeling, drug discovery and regenerative medicine strategies. Promoting the establishment of complex cell-cell interactions, 3D culture systems enable the development of human cell-based models with increased physiological relevance, over monolayer cultures. Here, we demonstrate the establishment of neuronal and astrocytic metabolic signatures and shuttles in a human 3D neural cell model, namely the glutamine-glutamate-GABA shuttle. This was indicated by labeling of neuronal GABA following incubation with the glia-specific substrate [2-(13)C]acetate, which decreased by methionine sulfoximine-induced inhibition of the glial enzyme glutamine synthetase. Cell metabolic specialization was further demonstrated by higher pyruvate carboxylase-derived labeling in glutamine than in glutamate, indicating its activity in astrocytes and not in neurons. Exposure to the neurotoxin acrylamide resulted in intracellular accumulation of glutamate and decreased GABA synthesis. These results suggest an acrylamide-induced impairment of neuronal synaptic vesicle trafficking and imbalanced glutamine-glutamate-GABA cycle, due to loss of cell-cell contacts at synaptic sites. This work demonstrates, for the first time to our knowledge, that neural differentiation of human cells in a 3D setting recapitulates neuronal-astrocytic metabolic interactions, highlighting the relevance of these models for toxicology and better understanding the crosstalk between human neural cells.
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Iizumi T, Takahashi S, Mashima K, Minami K, Izawa Y, Abe T, Hishiki T, Suematsu M, Kajimura M, Suzuki N. A possible role of microglia-derived nitric oxide by lipopolysaccharide in activation of astroglial pentose-phosphate pathway via the Keap1/Nrf2 system. J Neuroinflammation 2016; 13:99. [PMID: 27143001 PMCID: PMC4855896 DOI: 10.1186/s12974-016-0564-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/26/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Toll-like receptor 4 (TLR4) plays a pivotal role in the pathophysiology of stroke-induced inflammation. Both astroglia and microglia express TLR4, and endogenous ligands produced in the ischemic brain induce inflammatory responses. Reactive oxygen species (ROS), nitric oxide (NO), and inflammatory cytokines produced by TLR4 activation play harmful roles in neuronal damage after stroke. Although astroglia exhibit pro-inflammatory responses upon TLR4 stimulation by lipopolysaccharide (LPS), they may also play cytoprotective roles via the activation of the pentose phosphate pathway (PPP), reducing oxidative stress by glutathione peroxidase. We investigated the mechanisms by which astroglia reduce oxidative stress via the activation of PPP, using TLR4 stimulation and hypoxia in concert with microglia. METHODS In vitro experiments were performed using cells prepared from Sprague-Dawley rats. Coexisting microglia in the astroglial culture were chemically eliminated using L-leucine methyl ester (LME). Cells were exposed to LPS (0.01 μg/mL) or hypoxia (1 % O2) for 12-15 h. PPP activity was measured using [1-(14)C]glucose and [6-(14)C]glucose. ROS and NO production were measured using 2',7'-dichlorodihydrofluorescein diacetate and diaminofluorescein-FM diacetate, respectively. The involvement of nuclear factor-erythroid-2-related factor 2 (Nrf2), a cardinal transcriptional factor under stress conditions that regulates glucose 6-phosphate dehydrogenase, the rate-limiting enzyme of PPP, was evaluated using immunohistochemistry. RESULTS Cultured astroglia exposed to LPS elicited 20 % increases in PPP flux, and these actions of astroglia appeared to involve Nrf2. However, the chemical depletion of coexisting microglia eliminated both increases in PPP and astroglial nuclear translocation of Nrf2. LPS induced ROS and NO production in the astroglial culture containing microglia but not in the microglia-depleted astroglial culture. LPS enhanced astroglial ROS production after glutathione depletion. U0126, an upstream inhibitor of mitogen-activated protein kinase, eliminated LPS-induced NO production, whereas ROS production was unaffected. U0126 also eliminated LPS-induced PPP activation in astroglial-microglial culture, indicating that microglia-derived NO mediated astroglial PPP activation. Hypoxia induced astroglial PPP activation independent of the microglia-NO pathway. Elimination of ROS and NO production by sulforaphane, a natural Nrf2 activator, confirmed the astroglial protective mechanism. CONCLUSIONS Astroglia in concert with microglia may play a cytoprotective role for countering oxidative stress in stroke.
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Affiliation(s)
- Takuya Iizumi
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Shinichi Takahashi
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan.
| | - Kyoko Mashima
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Kazushi Minami
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Yoshikane Izawa
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
| | - Takato Abe
- Department of Neurology, Osaka City University Graduate School of Medicine, Osaka-shi, 545-8585, Osaka , Japan
| | - Takako Hishiki
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,Clinical and Translational Research Center, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Shinjuku-ku, 160-8582, Tokyo , Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Shinjuku-ku, 160-8582, Tokyo , Japan
| | - Mayumi Kajimura
- Department of Biochemistry, Keio University School of Medicine, Shinjuku-ku, 160-8582, Tokyo, Japan.,JST Exploratory Research for Advanced Technology (ERATO) Suematsu Gas Biology Project, Shinjuku-ku, 160-8582, Tokyo , Japan
| | - Norihiro Suzuki
- Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
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Iglesias J, Morales L, Barreto GE. Metabolic and Inflammatory Adaptation of Reactive Astrocytes: Role of PPARs. Mol Neurobiol 2016; 54:2518-2538. [PMID: 26984740 DOI: 10.1007/s12035-016-9833-2] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/04/2016] [Indexed: 01/10/2023]
Abstract
Astrocyte-mediated inflammation is associated with degenerative pathologies such as Alzheimer's and Parkinson's diseases and multiple sclerosis. The acute inflammation and morphological and metabolic changes that astrocytes develop after the insult are known as reactive astroglia or astrogliosis that is an important response to protect and repair the lesion. Astrocytes optimize their metabolism to produce lactate, glutamate, and ketone bodies in order to provide energy to the neurons that are deprived of nutrients upon insult. Firstly, we review the basis of inflammation and morphological changes of the different cell population implicated in reactive gliosis. Next, we discuss the more active metabolic pathways in healthy astrocytes and explain the metabolic response of astrocytes to the insult in different pathologies and which metabolic alterations generate complications in these diseases. We emphasize the role of peroxisome proliferator-activated receptors isotypes in the inflammatory and metabolic adaptation of astrogliosis developed in ischemia or neurodegenerative diseases. Based on results reported in astrocytes and other cells, we resume and hypothesize the effect of peroxisome proliferator-activated receptor (PPAR) activation with ligands on different metabolic pathways in order to supply energy to the neurons. The activation of selective PPAR isotype activity may serve as an input to better understand the role played by these receptors on the metabolic and inflammatory compensation of astrogliosis and might represent an opportunity to develop new therapeutic strategies against traumatic brain injuries and neurodegenerative diseases.
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Affiliation(s)
- José Iglesias
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia.
| | - Ludis Morales
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
- Universidad Científica del Sur, Lima, Peru
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15
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Amaral AI, Hadera MG, Tavares JM, Kotter MRN, Sonnewald U. Characterization of glucose-related metabolic pathways in differentiated rat oligodendrocyte lineage cells. Glia 2016; 64:21-34. [PMID: 26352325 PMCID: PMC4832329 DOI: 10.1002/glia.22900] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/22/2015] [Indexed: 12/24/2022]
Abstract
Although oligodendrocytes constitute a significant proportion of cells in the central nervous system (CNS), little is known about their intermediary metabolism. We have, therefore, characterized metabolic functions of primary oligodendrocyte precursor cell cultures at late stages of differentiation using isotope-labelled metabolites. We report that differentiated oligodendrocyte lineage cells avidly metabolize glucose in the cytosol and pyruvate derived from glucose in the mitochondria. The labelling patterns of metabolites obtained after incubation with [1,2-(13)C]glucose demonstrated that the pentose phosphate pathway (PPP) is highly active in oligodendrocytes (approximately 10% of glucose is metabolized via the PPP as indicated by labelling patterns in phosphoenolpyruvate). Mass spectrometry and magnetic resonance spectroscopy analyses of metabolites after incubation of cells with [1-(13)C]lactate or [1,2-(13)C]glucose, respectively, demonstrated that anaplerotic pyruvate carboxylation, which was thought to be exclusive to astrocytes, is also active in oligodendrocytes. Using [1,2-(13)C]acetate, we show that oligodendrocytes convert acetate into acetyl CoA which is metabolized in the tricarboxylic acid cycle. Analysis of labelling patterns of alanine after incubation of cells with [1,2-(13)C]acetate and [1,2-(13)C]glucose showed catabolic oxidation of malate or oxaloacetate. In conclusion, we report that oligodendrocyte lineage cells at late differentiation stages are metabolically highly active cells that are likely to contribute considerably to the metabolic activity of the CNS.
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Affiliation(s)
- Ana I. Amaral
- Anne McLaren LaboratoryWellcome Trust‐Medical Research Council Cambridge Stem Cell Institute and Department of Clinical Neurosciences, University of CambridgeCambridgeCB2 0SZUnited Kingdom
| | - Mussie G. Hadera
- Department of Neuroscience, Faculty of MedicineNorwegian University of Science and TechnologyTrondheim7491Norway
| | - Joana M. Tavares
- Anne McLaren LaboratoryWellcome Trust‐Medical Research Council Cambridge Stem Cell Institute and Department of Clinical Neurosciences, University of CambridgeCambridgeCB2 0SZUnited Kingdom
| | - Mark R. N. Kotter
- Anne McLaren LaboratoryWellcome Trust‐Medical Research Council Cambridge Stem Cell Institute and Department of Clinical Neurosciences, University of CambridgeCambridgeCB2 0SZUnited Kingdom
| | - Ursula Sonnewald
- Department of Neuroscience, Faculty of MedicineNorwegian University of Science and TechnologyTrondheim7491Norway
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagen2100Denmark
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16
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Kleiderman S, Sá JV, Teixeira AP, Brito C, Gutbier S, Evje LG, Hadera MG, Glaab E, Henry M, Sachinidis A, Alves PM, Sonnewald U, Leist M. Functional and phenotypic differences of pure populations of stem cell-derived astrocytes and neuronal precursor cells. Glia 2015; 64:695-715. [DOI: 10.1002/glia.22954] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 11/19/2015] [Accepted: 11/23/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Susanne Kleiderman
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| | - João V. Sá
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Ana P. Teixeira
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Catarina Brito
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Simon Gutbier
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
| | - Lars G. Evje
- Department of Earth Science, University of Bergen; Allégaten 41 5007 Bergen Norway
| | - Mussie G. Hadera
- Department of Pharmacy; College of Health Sciences; Mekelle University, Tigray Ethiopia
| | - Enrico Glaab
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg; Belvaux L-4366 Luxembourg
| | - Margit Henry
- Institute of Neurophysiology and Center for Molecular Medicine, Cologne (CMMC), University of Cologne; Cologne Germany
| | - Agapios Sachinidis
- Institute of Neurophysiology and Center for Molecular Medicine, Cologne (CMMC), University of Cologne; Cologne Germany
| | - Paula M. Alves
- Instituto de Tecnologia Química e Biológica António Xavier; Universidade Nova de Lisboa; Av. da República 2780-157 Oeiras Portugal
- IBET; Instituto de Biologia Experimental e Tecnológica; Apartado 12 2780-901 Oeiras Portugal
| | - Ursula Sonnewald
- Department of Drug Design and Pharmacology; Faculty of Health and Medical Sciences; Copenhagen Denmark
- Department of Neuroscience; Norwegian University of Science and Technology; Faculty of Medicine; Trondheim Norway
| | - Marcel Leist
- The Doerenkamp-Zbinden Chair of in-Vitro Toxicology and Biomedicine/Alternatives to Animal Experimentation; University of Konstanz; Konstanz Germany
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17
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Lv Y, Zhang B, Zhai C, Qiu J, Zhang Y, Yao W, Zhang C. PFKFB3-mediated glycolysis is involved in reactive astrocyte proliferation after oxygen-glucose deprivation/reperfusion and is regulated by Cdh1. Neurochem Int 2015; 91:26-33. [PMID: 26498254 DOI: 10.1016/j.neuint.2015.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 10/09/2015] [Accepted: 10/15/2015] [Indexed: 01/13/2023]
Abstract
Reactive astrocyte proliferation is involved in many central degenerative diseases. The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoform 3 (PFKFB3), an allosteric activator of 6-phosphofructo-1-kinase (PFK1), controls glycolytic flux. Furthermore, APC/C-Cdh1 plays a crucial role in brain metabolism by regulating PFKFB3 expression. Previous studies have defined the roles of PFKFB3-mediated glycolysis in pathological angiogenesis, cell autophagy, and amyloid plaque deposition in proliferating cells. However, the role of PFKFB3 in reactive astrocyte proliferation after cerebral ischemia is unknown. In this study, we cultured rat primary cortical astrocytes and established an oxygen-glucose deprivation/reperfusion (OGD/R) model to mimic cerebral ischemia in vivo. Astrocyte proliferation was measured by western blotting for proliferating cell nuclear antigen (PCNA) and by EdU incorporation. We found that OGD/R up-regulated PFKFB3 and PFK1 expression, which was accompanied by reactive astrocyte proliferation. Knockdown of PFKFB3 by siRNA transfection significantly inhibited reactive astrocyte proliferation and lactate release, an indicator of glycolysis. We found that PFKFB3 and PFK1 expression were down-regulated and lactate release was decreased when OGD/R-induced astrocyte proliferation was inhibited by a Cdh1-expressing lentivirus. Thus, reactive astrocyte proliferation can be effectively suppressed by down-regulation of PFKFB3 through control of glycolytic flux, which is downstream of APC/C-Cdh1.
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Affiliation(s)
- Youyou Lv
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Bo Zhang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Chunchun Zhai
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jin Qiu
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yue Zhang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wenlong Yao
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Chuanhan Zhang
- Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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18
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Sá JV, Duarte TM, Carrondo MJT, Alves PM, Teixeira AP. Metabolic Flux Analysis: A Powerful Tool in Animal Cell Culture. CELL ENGINEERING 2015. [DOI: 10.1007/978-3-319-10320-4_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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19
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Hypoxia and oxygenation induce a metabolic switch between pentose phosphate pathway and glycolysis in glioma stem-like cells. Acta Neuropathol 2013; 126:763-80. [PMID: 24005892 DOI: 10.1007/s00401-013-1173-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/14/2013] [Accepted: 08/25/2013] [Indexed: 12/12/2022]
Abstract
Fluctuations in oxygen tension during tissue remodeling impose a major metabolic challenge in human tumors. Stem-like tumor cells in glioblastoma, the most common malignant brain tumor, possess extraordinary metabolic flexibility, enabling them to initiate growth even under non-permissive conditions. We identified a reciprocal metabolic switch between the pentose phosphate pathway (PPP) and glycolysis in glioblastoma stem-like (GS) cells. Expression of PPP enzymes is upregulated by acute oxygenation but downregulated by hypoxia, whereas glycolysis enzymes, particularly those of the preparatory phase, are regulated inversely. Glucose flux through the PPP is reduced under hypoxia in favor of flux through glycolysis. PPP enzyme expression is elevated in human glioblastomas compared to normal brain, especially in highly proliferative tumor regions, whereas expression of parallel preparatory phase glycolysis enzymes is reduced in glioblastomas, except for strong upregulation in severely hypoxic regions. Hypoxia stimulates GS cell migration but reduces proliferation, whereas oxygenation has opposite effects, linking the metabolic switch to the "go or grow" potential of the cells. Our findings extend Warburg's observation that tumor cells predominantly utilize glycolysis for energy production, by suggesting that PPP activity is elevated in rapidly proliferating tumor cells but suppressed by acute severe hypoxic stress, favoring glycolysis and migration to protect cells against hypoxic cell damage.
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20
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Amaral AI. Effects of hypoglycaemia on neuronal metabolism in the adult brain: role of alternative substrates to glucose. J Inherit Metab Dis 2013; 36:621-34. [PMID: 23109064 DOI: 10.1007/s10545-012-9553-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 10/02/2012] [Accepted: 10/11/2012] [Indexed: 12/22/2022]
Abstract
Hypoglycaemia is characterized by decreased blood glucose levels and is associated with different pathologies (e.g. diabetes, inborn errors of metabolism). Depending on its severity, it might affect cognitive functions, including impaired judgment and decreased memory capacity, which have been linked to alterations of brain energy metabolism. Glucose is the major cerebral energy substrate in the adult brain and supports the complex metabolic interactions between neurons and astrocytes, which are essential for synaptic activity. Therefore, hypoglycaemia disturbs cerebral metabolism and, consequently, neuronal function. Despite the high vulnerability of neurons to hypoglycaemia, important neurochemical changes enabling these cells to prolong their resistance to hypoglycaemia have been described. This review aims at providing an overview over the main metabolic effects of hypoglycaemia on neurons, covering in vitro and in vivo findings. Recent studies provided evidence that non-glucose substrates including pyruvate, glycogen, ketone bodies, glutamate, glutamine, and aspartate, are metabolized by neurons in the absence of glucose and contribute to prolong neuronal function and delay ATP depletion during hypoglycaemia. One of the pathways likely implicated in the process is the pyruvate recycling pathway, which allows for the full oxidation of glutamate and glutamine. The operation of this pathway in neurons, particularly after hypoglycaemia, has been re-confirmed recently using metabolic modelling tools (i.e. Metabolic Flux Analysis), which allow for a detailed investigation of cellular metabolism in cultured cells. Overall, the knowledge summarized herein might be used for the development of potential therapies targeting neuronal protection in patients vulnerable to hypoglycaemic episodes.
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Affiliation(s)
- Ana I Amaral
- Anne McLaren Laboratory for Regenerative Medicine, Department of Clinical Neurosciences, MRC Centre for Stem Cell Biology and Regenerative Medicine, University of Cambridge, West Forvie Building, Robinson Way, CB2 0SZ Cambridge, UK.
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21
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Bak LK, Waagepetersen HS, Sørensen M, Ott P, Vilstrup H, Keiding S, Schousboe A. Role of branched chain amino acids in cerebral ammonia homeostasis related to hepatic encephalopathy. Metab Brain Dis 2013; 28:209-15. [PMID: 23371316 DOI: 10.1007/s11011-013-9381-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 01/17/2013] [Indexed: 12/30/2022]
Abstract
Hepatic encephalopathy (HE) is associated with increased ammonia levels in plasma and brain. Different treatment strategies have been developed to ameliorate the detrimental effects of the ammonia load. One such strategy is based on the finding of a low level of the branched chain amino acids (BCAAs) in plasma of patients suffering from HE and the assumption that in particular isoleucine could be beneficial to brain energy metabolism as it is metabolized to the tricarboxylic acid cycle intermediate and precursor succinyl-CoA and acetyl-CoA, respectively. This would enable de novo synthesis of glutamine via α-ketoglutarate and glutamate and at the same time stimulate oxidative metabolism. The present mini-review summarizes the metabolic basis for this hypothesis delineating studies in the brain in vivo as well as in cultured neural cells aimed at elucidating the metabolism of the BCAAs focusing on isoleucine. The conclusion is that isoleucine appears at least partially to act in this fashion albeit its metabolism is quantitatively relatively modest. In addition, a short section on the role of the BCAAs in synaptic ammonia homeostasis is included along with some thoughts on the role of the BCAAs in other pathologies such as cancer.
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Affiliation(s)
- Lasse K Bak
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark.
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22
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Riganti C, Gazzano E, Polimeni M, Aldieri E, Ghigo D. The pentose phosphate pathway: an antioxidant defense and a crossroad in tumor cell fate. Free Radic Biol Med 2012; 53:421-36. [PMID: 22580150 DOI: 10.1016/j.freeradbiomed.2012.05.006] [Citation(s) in RCA: 286] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Revised: 04/14/2012] [Accepted: 05/03/2012] [Indexed: 01/10/2023]
Abstract
The pentose phosphate pathway, one of the main antioxidant cellular defense systems, has been related for a long time almost exclusively to its role as a provider of reducing power and ribose phosphate to the cell. In addition to this "traditional" correlation, in the past years multiple roles have emerged for this metabolic cascade, involving the cell cycle, apoptosis, differentiation, motility, angiogenesis, and the response to anti-tumor therapy. These findings make the pentose phosphate pathway a very interesting target in tumor cells. This review summarizes the latest discoveries relating the activity of the pentose phosphate pathway to various aspects of tumor metabolism, such as cell proliferation and death, tissue invasion, angiogenesis, and resistance to therapy, and discusses the possibility that drugs modulating the pathway could be used as potential tools in tumor therapy.
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Affiliation(s)
- Chiara Riganti
- Department of Genetics, Biology, and Biochemistry, University of Torino, Turin, Italy.
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23
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Crean D, Felice L, Taylor CT, Rabb H, Jennings P, Leonard MO. Glucose reintroduction triggers the activation of Nrf2 during experimental ischemia reperfusion. Mol Cell Biochem 2012; 366:231-8. [DOI: 10.1007/s11010-012-1300-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 03/17/2012] [Indexed: 12/01/2022]
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de Mas IM, Selivanov VA, Marin S, Roca J, Orešič M, Agius L, Cascante M. Compartmentation of glycogen metabolism revealed from 13C isotopologue distributions. BMC SYSTEMS BIOLOGY 2011; 5:175. [PMID: 22034837 PMCID: PMC3292525 DOI: 10.1186/1752-0509-5-175] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2011] [Accepted: 10/28/2011] [Indexed: 11/24/2022]
Abstract
Background Stable isotope tracers are used to assess metabolic flux profiles in living cells. The existing methods of measurement average out the isotopic isomer distribution in metabolites throughout the cell, whereas the knowledge of compartmental organization of analyzed pathways is crucial for the evaluation of true fluxes. That is why we accepted a challenge to create a software tool that allows deciphering the compartmentation of metabolites based on the analysis of average isotopic isomer distribution. Results The software Isodyn, which simulates the dynamics of isotopic isomer distribution in central metabolic pathways, was supplemented by algorithms facilitating the transition between various analyzed metabolic schemes, and by the tools for model discrimination. It simulated 13C isotope distributions in glucose, lactate, glutamate and glycogen, measured by mass spectrometry after incubation of hepatocytes in the presence of only labeled glucose or glucose and lactate together (with label either in glucose or lactate). The simulations assumed either a single intracellular hexose phosphate pool, or also channeling of hexose phosphates resulting in a different isotopic composition of glycogen. Model discrimination test was applied to check the consistency of both models with experimental data. Metabolic flux profiles, evaluated with the accepted model that assumes channeling, revealed the range of changes in metabolic fluxes in liver cells. Conclusions The analysis of compartmentation of metabolic networks based on the measured 13C distribution was included in Isodyn as a routine procedure. The advantage of this implementation is that, being a part of evaluation of metabolic fluxes, it does not require additional experiments to study metabolic compartmentation. The analysis of experimental data revealed that the distribution of measured 13C-labeled glucose metabolites is inconsistent with the idea of perfect mixing of hexose phosphates in cytosol. In contrast, the observed distribution indicates the presence of a separate pool of hexose phosphates that is channeled towards glycogen synthesis.
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Affiliation(s)
- Igor Marin de Mas
- Department of Biochemistry and Molecular Biology, Faculty of Biology, Universitat de Barcelona, Av Diagonal 643, 08028 Barcelona, Spain
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Amaral AI, Teixeira AP, Håkonsen BI, Sonnewald U, Alves PM. A comprehensive metabolic profile of cultured astrocytes using isotopic transient metabolic flux analysis and C-labeled glucose. FRONTIERS IN NEUROENERGETICS 2011; 3:5. [PMID: 21941478 PMCID: PMC3171112 DOI: 10.3389/fnene.2011.00005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 08/04/2011] [Indexed: 12/21/2022]
Abstract
Metabolic models have been used to elucidate important aspects of brain metabolism in recent years. This work applies for the first time the concept of isotopic transient 13C metabolic flux analysis (MFA) to estimate intracellular fluxes in primary cultures of astrocytes. This methodology comprehensively explores the information provided by 13C labeling time-courses of intracellular metabolites after administration of a 13C-labeled substrate. Cells were incubated with medium containing [1-13C]glucose for 24 h and samples of cell supernatant and extracts collected at different time points were then analyzed by mass spectrometry and/or high performance liquid chromatography. Metabolic fluxes were estimated by fitting a carbon labeling network model to isotopomer profiles experimentally determined. Both the fast isotopic equilibrium of glycolytic metabolite pools and the slow labeling dynamics of TCA cycle intermediates are described well by the model. The large pools of glutamate and aspartate which are linked to the TCA cycle via reversible aminotransferase reactions are likely to be responsible for the observed delay in equilibration of TCA cycle intermediates. Furthermore, it was estimated that 11% of the glucose taken up by astrocytes was diverted to the pentose phosphate pathway. In addition, considerable fluxes through pyruvate carboxylase [PC; PC/pyruvate dehydrogenase (PDH) ratio = 0.5], malic enzyme (5% of the total pyruvate production), and catabolism of branched-chained amino acids (contributing with ∼40% to total acetyl-CoA produced) confirmed the significance of these pathways to astrocytic metabolism. Consistent with the need of maintaining cytosolic redox potential, the fluxes through the malate–aspartate shuttle and the PDH pathway were comparable. Finally, the estimated glutamate/α-ketoglutarate exchange rate (∼0.7 μmol mg prot−1 h−1) was similar to the TCA cycle flux. In conclusion, this work demonstrates the potential of isotopic transient MFA for a comprehensive analysis of energy metabolism.
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Affiliation(s)
- Ana I Amaral
- Instituto de Tecnologia Química e Biológica - Universidade Nova de Lisboa Oeiras, Portugal
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26
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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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27
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Niklas J, Heinzle E. Metabolic flux analysis in systems biology of mammalian cells. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2011; 127:109-32. [PMID: 21432052 DOI: 10.1007/10_2011_99] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Reaction rates or metabolic fluxes reflect the integrated phenotype of genome, transcriptome and proteome interactions, including regulation at all levels of the cellular hierarchy. Different methods have been developed in the past to analyse intracellular fluxes. However, compartmentation of mammalian cells, varying utilisation of multiple substrates, reversibility of metabolite uptake and production, unbalanced growth behaviour and adaptation of cells to changing environment during cultivation are just some reasons that make metabolic flux analysis (MFA) in mammalian cell culture more challenging compared to microorganisms. In this article MFA using the metabolite balancing methodology and the advantages and disadvantages of (13)C MFA in mammalian cell systems are reviewed. Application examples of MFA in the optimisation of cell culture processes for the production of biopharmaceuticals are presented with a focus on the metabolism of the main industrial workhorse. Another area in which mammalian cell culture plays a key role is in medical and toxicological research. It is shown that MFA can be used to understand pathophysiological mechanisms and can assist in understanding effects of drugs or other compounds on cellular metabolism.
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Affiliation(s)
- Jens Niklas
- Biochemical Engineering Institute, Saarland University, Campus A 1.5, 66123, Saarbrücken, Germany
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