1
|
Denker N, Dringen R. Modulation of Pyruvate Export and Extracellular Pyruvate Concentration in Primary Astrocyte Cultures. Neurochem Res 2024; 49:1331-1346. [PMID: 38376749 PMCID: PMC10991036 DOI: 10.1007/s11064-024-04120-0] [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: 11/10/2023] [Revised: 02/02/2024] [Accepted: 02/02/2024] [Indexed: 02/21/2024]
Abstract
Astrocyte-derived pyruvate is considered to have neuroprotective functions. In order to investigate the processes that are involved in astrocytic pyruvate release, we used primary rat astrocyte cultures as model system. Depending on the incubation conditions and medium composition, astrocyte cultures established extracellular steady state pyruvate concentrations in the range between 150 µM and 300 µM. During incubations for up to 2 weeks in DMEM culture medium, the extracellular pyruvate concentration remained almost constant for days, while the extracellular lactate concentration increased continuously during the incubation into the millimolar concentration range as long as glucose was present. In an amino acid-free incubation buffer, glucose-fed astrocytes released pyruvate with an initial rate of around 60 nmol/(h × mg) and after around 5 h an almost constant extracellular pyruvate concentration was established that was maintained for several hours. Extracellular pyruvate accumulation was also observed, if glucose had been replaced by mannose, fructose, lactate or alanine. Glucose-fed astrocyte cultures established similar extracellular steady state concentrations of pyruvate by releasing pyruvate into pyruvate-free media or by consuming excess of extracellular pyruvate. Inhibition of the monocarboxylate transporter MCT1 by AR-C155858 lowered extracellular pyruvate accumulation, while inhibition of mitochondrial pyruvate uptake by UK5099 increased the extracellular pyruvate concentration. Finally, the presence of the uncoupler BAM15 or of the respiratory chain inhibitor antimycin A almost completely abolished extracellular pyruvate accumulation. The data presented demonstrate that cultured astrocytes establish a transient extracellular steady state concentration of pyruvate which is strongly affected by modulation of the mitochondrial pyruvate metabolism.
Collapse
Affiliation(s)
- Nadine Denker
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry) and Centre for Environmental Research and Sustainable Technologies, University of Bremen, P.O. Box 330440, 28334, Bremen, Germany
| | - Ralf Dringen
- Centre for Biomolecular Interactions Bremen, Faculty 2 (Biology/Chemistry) and Centre for Environmental Research and Sustainable Technologies, University of Bremen, P.O. Box 330440, 28334, Bremen, Germany.
| |
Collapse
|
2
|
Rae CD, Baur JA, Borges K, Dienel G, Díaz-García CM, Douglass SR, Drew K, Duarte JMN, Duran J, Kann O, Kristian T, Lee-Liu D, Lindquist BE, McNay EC, Robinson MB, Rothman DL, Rowlands BD, Ryan TA, Scafidi J, Scafidi S, Shuttleworth CW, Swanson RA, Uruk G, Vardjan N, Zorec R, McKenna MC. Brain energy metabolism: A roadmap for future research. J Neurochem 2024; 168:910-954. [PMID: 38183680 PMCID: PMC11102343 DOI: 10.1111/jnc.16032] [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: 05/27/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 01/08/2024]
Abstract
Although we have learned much about how the brain fuels its functions over the last decades, there remains much still to discover in an organ that is so complex. This article lays out major gaps in our knowledge of interrelationships between brain metabolism and brain function, including biochemical, cellular, and subcellular aspects of functional metabolism and its imaging in adult brain, as well as during development, aging, and disease. The focus is on unknowns in metabolism of major brain substrates and associated transporters, the roles of insulin and of lipid droplets, the emerging role of metabolism in microglia, mysteries about the major brain cofactor and signaling molecule NAD+, as well as unsolved problems underlying brain metabolism in pathologies such as traumatic brain injury, epilepsy, and metabolic downregulation during hibernation. It describes our current level of understanding of these facets of brain energy metabolism as well as a roadmap for future research.
Collapse
Affiliation(s)
- Caroline D. Rae
- School of Psychology, The University of New South Wales, NSW 2052 & Neuroscience Research Australia, Randwick, New South Wales, Australia
| | - Joseph A. Baur
- Department of Physiology and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, Australia
| | - Gerald Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - Carlos Manlio Díaz-García
- Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | - Kelly Drew
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - João M. N. Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, & Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Jordi Duran
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL), Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Tibor Kristian
- Veterans Affairs Maryland Health Center System, Baltimore, Maryland, USA
- Department of Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research (S.T.A.R.), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dasfne Lee-Liu
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Región Metropolitana, Chile
| | - Britta E. Lindquist
- Department of Neurology, Division of Neurocritical Care, Gladstone Institute of Neurological Disease, University of California at San Francisco, San Francisco, California, USA
| | - Ewan C. McNay
- Behavioral Neuroscience, University at Albany, Albany, New York, USA
| | - Michael B. Robinson
- Departments of Pediatrics and System Pharmacology & Translational Therapeutics, Children’s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Douglas L. Rothman
- Magnetic Resonance Research Center and Departments of Radiology and Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Benjamin D. Rowlands
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Timothy A. Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, New York, USA
| | - Joseph Scafidi
- Department of Neurology, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Susanna Scafidi
- Anesthesiology & Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - C. William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine Albuquerque, Albuquerque, New Mexico, USA
| | - Raymond A. Swanson
- Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Gökhan Uruk
- Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Nina Vardjan
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology—Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology—Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Mary C. McKenna
- Department of Pediatrics and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
3
|
Kann O. Lactate as a supplemental fuel for synaptic transmission and neuronal network oscillations: Potentials and limitations. J Neurochem 2024; 168:608-631. [PMID: 37309602 DOI: 10.1111/jnc.15867] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/14/2023]
Abstract
Lactate shuttled from the blood circulation, astrocytes, oligodendrocytes or even activated microglia (resident macrophages) to neurons has been hypothesized to represent a major source of pyruvate compared to what is normally produced endogenously by neuronal glucose metabolism. However, the role of lactate oxidation in fueling neuronal signaling associated with complex cortex function, such as perception, motor activity, and memory formation, is widely unclear. This issue has been experimentally addressed using electrophysiology in hippocampal slice preparations (ex vivo) that permit the induction of different neural network activation states by electrical stimulation, optogenetic tools or receptor ligand application. Collectively, these studies suggest that lactate in the absence of glucose (lactate only) impairs gamma (30-70 Hz) and theta-gamma oscillations, which feature high energy demand revealed by the cerebral metabolic rate of oxygen (CMRO2, set to 100%). The impairment comprises oscillation attenuation or moderate neural bursts (excitation-inhibition imbalance). The bursting is suppressed by elevating the glucose fraction in energy substrate supply. By contrast, lactate can retain certain electric stimulus-induced neural population responses and intermittent sharp wave-ripple activity that features lower energy expenditure (CMRO2 of about 65%). Lactate utilization increases the oxygen consumption by about 9% during sharp wave-ripples reflecting enhanced adenosine-5'-triphosphate (ATP) synthesis by oxidative phosphorylation in mitochondria. Moreover, lactate attenuates neurotransmission in glutamatergic pyramidal cells and fast-spiking, γ-aminobutyric acid (GABA)ergic interneurons by reducing neurotransmitter release from presynaptic terminals. By contrast, the generation and propagation of action potentials in the axon is regular. In conclusion, lactate is less effective than glucose and potentially detrimental during neural network rhythms featuring high energetic costs, likely through the lack of some obligatory ATP synthesis by aerobic glycolysis at excitatory and inhibitory synapses. High lactate/glucose ratios might contribute to central fatigue, cognitive impairment, and epileptic seizures partially seen, for instance, during exhaustive physical exercise, hypoglycemia and neuroinflammation.
Collapse
Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| |
Collapse
|
4
|
Kostyuk AI, Rapota DD, Morozova KI, Fedotova AA, Jappy D, Semyanov AV, Belousov VV, Brazhe NA, Bilan DS. Modern optical approaches in redox biology: Genetically encoded sensors and Raman spectroscopy. Free Radic Biol Med 2024; 217:68-115. [PMID: 38508405 DOI: 10.1016/j.freeradbiomed.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/10/2024] [Accepted: 03/13/2024] [Indexed: 03/22/2024]
Abstract
The objective of the current review is to summarize the current state of optical methods in redox biology. It consists of two parts, the first is dedicated to genetically encoded fluorescent indicators and the second to Raman spectroscopy. In the first part, we provide a detailed classification of the currently available redox biosensors based on their target analytes. We thoroughly discuss the main architecture types of these proteins, the underlying engineering strategies for their development, the biochemical properties of existing tools and their advantages and disadvantages from a practical point of view. Particular attention is paid to fluorescence lifetime imaging microscopy as a possible readout technique, since it is less prone to certain artifacts than traditional intensiometric measurements. In the second part, the characteristic Raman peaks of the most important redox intermediates are listed, and examples of how this knowledge can be implemented in biological studies are given. This part covers such fields as estimation of the redox states and concentrations of Fe-S clusters, cytochromes, other heme-containing proteins, oxidative derivatives of thiols, lipids, and nucleotides. Finally, we touch on the issue of multiparameter imaging, in which biosensors are combined with other visualization methods for simultaneous assessment of several cellular parameters.
Collapse
Affiliation(s)
- Alexander I Kostyuk
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Pirogov Russian National Research Medical University, 117997, Moscow, Russia
| | - Diana D Rapota
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia
| | - Kseniia I Morozova
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - Anna A Fedotova
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia
| | - David Jappy
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, 117997, Russia
| | - Alexey V Semyanov
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia; Sechenov First Moscow State Medical University, Moscow, 119435, Russia; College of Medicine, Jiaxing University, Jiaxing, Zhejiang Province, 314001, China
| | - Vsevolod V Belousov
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Pirogov Russian National Research Medical University, 117997, Moscow, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, 117997, Russia; Life Improvement by Future Technologies (LIFT) Center, Skolkovo, Moscow, 143025, Russia
| | - Nadezda A Brazhe
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119234, Russia.
| | - Dmitry S Bilan
- M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, 117997, Russia; Pirogov Russian National Research Medical University, 117997, Moscow, Russia.
| |
Collapse
|
5
|
Delgado MG, Delgado R. Transient Synaptic Enhancement Triggered by Exogenously Supplied Monocarboxylate in Drosophila Motoneuron Synapse. Neuroscience 2024; 539:66-75. [PMID: 38220128 DOI: 10.1016/j.neuroscience.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 01/05/2024] [Accepted: 01/09/2024] [Indexed: 01/16/2024]
Abstract
Current evidence suggests that glial cells provide C3 carbon sources to fuel neuronal activity; however, this notion has become challenged by biosensor studies carried out in acute brain slices or in vivo, showing that neuronal activity does not rely on the import of astrocyte-produced L-lactate. Rather, stimulated neurons become net lactate exporters, as it was also shown in Drosophila neurons, in which astrocyte-provided lactate returns as lipid droplets to be stored in glial cells. In this view, we investigate whether exogenously supplied monocarboxylates can support Drosophila motoneuron neurotransmitter release (NTR). By assessing the excitatory post-synaptic current (EPSC) amplitude under voltage-clamp as NTR indicative, we found that both pyruvate and L-lactate, as the only carbon sources in the synapses bathing-solution, cause a large transient NTR enhancement, which declines to reach a synaptic depression state, from which the synapses do not recover. The FM1-43 pre-synaptic loading ability, however, is maintained under monocarboxylate, suggesting that SV cycling should not contribute to the synaptic depression state. The NTR recovery was reached by supplementing the monocarboxylate medium with sucrose. However, monocarboxylate addition to sucrose medium does not enhance NTR, but it does when the disaccharide concentration becomes too reduced. Thus, when pyruvate concentrations become too reduced, exogenously supplied L-lactate could be converted to pyruvate and metabolized by the neural mitochondria, triggering the NTR enhancement. SIGNIFICANCE STATEMENT: The question of whether monocarboxylic acids can fuel the Drosophila motoneuron NTR was challenged. Our findings show that exogenously supplied monocarboxylates trigger a large transient synaptic enhancement just under extreme glycolysis reduction but fail to maintain NTR under sustained synaptic demand, still at low frequency stimulation, driven to the synapses to a synaptic depression state. Glycolysis activation, by adding sucrose to the monocarboxylate bath solution, restores the motoneuron NTR ability, giving place to a hexoses role in SV recruitment. Moreover these results suggest exogenously supplied C3 carbon sources could have an additional role beyond providing energetic support for neural activity.
Collapse
Affiliation(s)
- María-Graciela Delgado
- Department of Biology, Faculty of Sciences, University of Chile, Las Palmeras 3425, 7800001 Santiago, Chile.
| | - Ricardo Delgado
- Department of Biology, Faculty of Sciences, University of Chile, Las Palmeras 3425, 7800001 Santiago, Chile.
| |
Collapse
|
6
|
Schurr A. How the 'Aerobic/Anaerobic Glycolysis' Meme Formed a 'Habit of Mind' Which Impedes Progress in the Field of Brain Energy Metabolism. Int J Mol Sci 2024; 25:1433. [PMID: 38338711 PMCID: PMC10855259 DOI: 10.3390/ijms25031433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
The division of glycolysis into two separate pathways, aerobic and anaerobic, depending on the presence or absence of oxygen, respectively, was formulated over eight decades ago. The former ends with pyruvate, while the latter ends with lactate. Today, this division is confusing and misleading as research over the past 35 years clearly has demonstrated that glycolysis ends with lactate not only in cancerous cells but also in healthy tissues and cells. The present essay offers a review of the history of said division and the more recent knowledge that has been gained about glycolysis and its end-product, lactate. Then, it presents arguments in an attempt to explain why separating glycolysis into aerobic and anaerobic pathways persists among scientists, clinicians and teachers alike, despite convincing evidence that such division is not only wrong scientifically but also hinders progress in the field of energy metabolism.
Collapse
Affiliation(s)
- Avital Schurr
- Department of Anesthesiology and Perioperative Medicine, University of Louisville School of Medicine, Louisville, KY 40202, USA
| |
Collapse
|
7
|
Roosterman D, Cottrell GS. Discovery of a second citric acid cycle complex. Heliyon 2023; 9:e15968. [PMID: 37251852 PMCID: PMC10209337 DOI: 10.1016/j.heliyon.2023.e15968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/31/2023] Open
Abstract
Together, Nobel Prize honoured work, mathematics, physics and the laws of nature have drawn a concept of clockwise cycling carboxylic acids in Krebs' Citric Acid Cycle. A Citric Acid Cycle complex is defined by specific substrate, product and regulation. Recently, the Citric Acid Cycle 1.1 complex was introduced as an NAD+-regulated cycle with the substrate, lactic acid and the product, malic acid. Here, we introduce the concept of the Citric Acid Cycle 2.1 complex as an FAD-regulated cycle with the substrate, malic acid and the products, succinic acid or citric acid. The function of the Citric Acid Cycle 2.1 complex is to balance stress situations within the cell. We propose that the biological function of Citric Acid Cycle 2.1 in muscles is to accelerate recovery of ATP; whereas in white tissue adipocytes our testing of the theoretical concept led to the storage of energy as lipids.
Collapse
|
8
|
Zhang D, Lü J, Ren Z, Zhang X, Wu H, Sa R, Wang X, Wang Y, Lin Z, Zhang B. Potential cardiotoxicity induced by Euodiae Fructus: In vivo and in vitro experiments and untargeted metabolomics research. Front Pharmacol 2022; 13:1028046. [PMID: 36353487 PMCID: PMC9637925 DOI: 10.3389/fphar.2022.1028046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/05/2022] [Indexed: 09/16/2023] Open
Abstract
Background: Euodiae Fructus, a well-known herbal medicine, is widely used in Asia and has also gained in popularity in Western countries over the last decades. It has known side effects, which have been observed in clinical settings, but few studies have reported on its cardiotoxicity. Methods: In the present study, experiments using techniques of untargeted metabolomics clarify the hazardous effects of Euodiae Fructus on cardiac function and metabolism in rats in situations of overdosage and unsuitable syndrome differentiation. In vitro assays are conducted to observe the toxic effects of evodiamine and rutaecarpine, two main chemical constituents of Euodiae Fructus, in H9c2 and neonatal rat cardiomyocytes (NRCMs), with their signaling mechanisms analyzed accordingly. Results: The cardiac cytotoxicity of evodiamine and rutaecarpine in in vivo experiments is associated with remarkable alterations in lactate dehydrogenase, creatine kinase, and mitochondrial membrane potential; also with increased intensity of calcium fluorescence, decreased protein expression of the cGMP-PKG pathway in H9c2 cells, and frequency of spontaneous beat in NRCMs. Additionally, the results in rats with Yin deficiency receiving a high-dosage of Euodiae Fructus suggest obvious cardiac physiological dysfunction, abnormal electrocardiogram, pathological injuries, and decreased expression of PKG protein. At the level of endogenous metabolites, the cardiac side effects of overdose and irrational usage of Euodiae Fructus relate to 34 differential metabolites and 10 metabolic pathways involving among others, the purine metabolism, the glycerophospholipid metabolism, the glycerolipid metabolism, and the sphingolipid metabolism. Conclusion: These findings shed new light on the cardiotoxicity induced by Euodiae Fructus, which might be associated with overdose and unsuitable syndrome differentiation, that comes from modulating the cGMP-PKG pathway and disturbing the metabolic pathways of purine, lipid, and amino acid. Continuing research is needed to ensure pharmacovigilance for the safe administration of Chinese herbs in the future.
Collapse
Affiliation(s)
- Dan Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Jintao Lü
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Zhixin Ren
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Xiaomeng Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
- Centre for Pharmacovigilance and Rational Use of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Huanzhang Wu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Rina Sa
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
- Gansu Provincial Hospital, Lanzhou, China
| | - Xiaofang Wang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Yu Wang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
- Centre for Pharmacovigilance and Rational Use of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Zhijian Lin
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
- Centre for Pharmacovigilance and Rational Use of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Bing Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
- Centre for Pharmacovigilance and Rational Use of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| |
Collapse
|
9
|
Manoj KM, Nirusimhan V, Parashar A, Edward J, Gideon DA. Murburn precepts for lactic-acidosis, Cori cycle, and Warburg effect: Interactive dynamics of dehydrogenases, protons, and oxygen. J Cell Physiol 2021; 237:1902-1922. [PMID: 34927737 DOI: 10.1002/jcp.30661] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 12/24/2022]
Abstract
It is unresolved why lactate is transported to the liver for further utilization within the physiological purview of Cori cycle, when muscles have more lactate dehydrogenase (LDH) than liver. We point out that the answer lies in thermodynamics/equilibriums. While the utilization of NADH for the reduction of pyruvate to lactate can be mediated via the classical mechanism, the oxidation of lactate (with/without the uphill reduction of NAD+ ) necessitates alternative physiological approaches. The latter pathway occurs via interactive equilibriums involving the enzyme, protons and oxygen or diffusible reactive oxygen species (DROS). Since liver has high DROS, the murburn activity at LDH would enable the cellular system to tide over the unfavorable energy barriers of the forward reaction (~476 kJ/mol; earlier miscalculated as ~26 kJ/mole). Further, the new mechanism does not necessitate any "smart decision-making" or sophisticated control by/of proteins. The DROS-based murburn theory explains the invariant active-site structure of LDH isozymes and their multimeric nature. The theoretical insights, in silico evidence and analyses of literature herein also enrich our understanding of the underpinnings of "lactic acidosis" (lowering of physiological pH accompanied by lactate production), Warburg effect (increased lactate production at high pO2 by cancer cells) and approach for cancer therapy.
Collapse
Affiliation(s)
- Kelath Murali Manoj
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
| | - Vijay Nirusimhan
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
| | - Abhinav Parashar
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
| | - Jesucastin Edward
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
| | - Daniel Andrew Gideon
- Department of Biochemistry, Satyamjayatu: The Science & Ethics Foundation, Palakkad, Kerala, India
| |
Collapse
|
10
|
Guo E, Guo L, An C, Zhang C, Song K, Wang G, Duan C, Zhang X, Yang X, Yuan Z, Guo J, Sun J, Meng H, Chang R, Li X, Xiu C, Mao X, Miao S. Prognostic Significance of Lactate Dehydrogenase in Patients Undergoing Surgical Resection for Laryngeal Squamous Cell Carcinoma. Cancer Control 2021; 27:1073274820978795. [PMID: 33297727 PMCID: PMC8480349 DOI: 10.1177/1073274820978795] [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] [Indexed: 12/03/2022] Open
Abstract
The aim is to estimate the prognostic value of lactate dehydrogenase (LDH) in patients undergoing surgical resection for laryngeal squamous cell carcinoma (LSCC). A total of 640 resected LSCC patients were included. Preoperative lactate dehydrogenase (LDH) was assessed. Kaplan-Meier survival analysis and Cox regression analysis were conducted for overall survival (OS) and recurrence-free survival (RFS). Kaplan-Meier analysis, univariate analysis and multivariate analysis demonstrated significant prognostic value for preoperative LDH. Although LDH was predictor of OS, it failed to be a predictor of RFS. The univariate HR and 95% CI of LDH were 0.484 and 0.357-0.658 (P < 0.0001). The multivariate analysis showed that LDH (HR = 0.518, 95% CI: 0.380-0.705, p < 0.0001) was related to OS. Elevated preoperative LDH >132 IU/L was significantly associated with better survival. Preoperative LDH might be an independent prognostic marker of OS in LSCC patients undergoing surgical resection.
Collapse
Affiliation(s)
- Erliang Guo
- Department of Surgery, The 2nd Affiliated Hospital of Harbin Medical University, Harbin 150081, China.,* These two authors have contributed equally to the work
| | - Lunhua Guo
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China.,* These two authors have contributed equally to the work
| | - Changming An
- Department of Head and Neck Surgery, Chinese National Cancer Center & Chinese Academy of Medical Sciences Cancer Hospital. Beijing 100000, China
| | - Cong Zhang
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Kaibin Song
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Guohui Wang
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Chunbin Duan
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Xiwei Zhang
- Department of Head and Neck Surgery, Chinese National Cancer Center & Chinese Academy of Medical Sciences Cancer Hospital. Beijing 100000, China
| | - Xianguang Yang
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Zhennan Yuan
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Junnan Guo
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Ji Sun
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Hongxue Meng
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Rui Chang
- Department of Head and Neck Surgery, Anyang Cancer Hospital, Anyang 455000, China
| | - Xiaomei Li
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Cheng Xiu
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Xionghui Mao
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| | - Susheng Miao
- Department of Head and Neck Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China
| |
Collapse
|
11
|
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.
Collapse
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.
| |
Collapse
|
12
|
Purba TS, Berriche L, Paus R. Compartmentalised metabolic programmes in human anagen hair follicles: New targets to modulate epithelial stem cell behaviour, keratinocyte proliferation and hair follicle immune status? Exp Dermatol 2021; 30:645-651. [PMID: 33548088 DOI: 10.1111/exd.14300] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/12/2021] [Accepted: 02/02/2021] [Indexed: 01/09/2023]
Abstract
Human scalp hair follicles (HF) preferentially engage in glycolysis followed by lactate production in the presence of oxygen (i.e. the Warburg effect). Through the spatiotemporally controlled expression of key metabolic proteins, we hypothesise that the Warburg effect and other HF metabolic programmes are compartmentalised by region in order to regulate regional cell fate and phenotypes, such as epithelial stem cell quiescence in the bulge or keratinocyte proliferation in the hair matrix. We further propose that metabolic conditions in the HF are organised in accordance with the lactate shuttle, hypothesised to occur in other tissue systems and tumours, but never before described in the HF. Specifically, we argue that lactate is produced and exported by glycolytic GLUT1+ lower outer root sheath (ORS) keratinocytes. We further propose that lactate is then utilised by neighbouring highly proliferative matrix keratinocytes to fuel oxidative metabolism via MCT1-mediated uptake. Furthermore, as lactate has been described to be immunomodulatory, its production and accumulation could enhance immune tolerance in the HF bulb. Here we delineate how to experimentally probe this hypothesis, define major open questions and present preliminary immunohistological evidence in support of metabolic compartmentalisation and lactate shuttling. Overall, we argue that basic and translational hair research needs to rediscover the importance of lactate in human HF biology, well beyond its recognised role in murine HF epithelial stem cells, and should explore how HF metabolism can be therapeutically targeted to modulate hair growth and the immunological HF microenvironment as a novel strategy for managing hair loss disorders.
Collapse
Affiliation(s)
- Talveen S Purba
- Centre for Dermatology Research, School of Biological Sciences, University of Manchester & NIHR Biomedical Research Centre, Manchester, UK
| | - Leïla Berriche
- Centre for Dermatology Research, School of Biological Sciences, University of Manchester & NIHR Biomedical Research Centre, Manchester, UK.,Claude Bernard Lyon 1, Lyon, France
| | - Ralf Paus
- Centre for Dermatology Research, School of Biological Sciences, University of Manchester & NIHR Biomedical Research Centre, Manchester, UK.,Monasterium Laboratory, Münster, Germany.,Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
13
|
Kiran D, Basaraba RJ. Lactate Metabolism and Signaling in Tuberculosis and Cancer: A Comparative Review. Front Cell Infect Microbiol 2021; 11:624607. [PMID: 33718271 PMCID: PMC7952876 DOI: 10.3389/fcimb.2021.624607] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/13/2021] [Indexed: 12/16/2022] Open
Abstract
Infection with Mycobacterium tuberculosis (Mtb) leading to tuberculosis (TB) disease continues to be a major global health challenge. Critical barriers, including but not limited to the development of multi-drug resistance, lack of diagnostic assays that detect patients with latent TB, an effective vaccine that prevents Mtb infection, and infectious and non-infectious comorbidities that complicate active TB, continue to hinder progress toward a TB cure. To complement the ongoing development of new antimicrobial drugs, investigators in the field are exploring the value of host-directed therapies (HDTs). This therapeutic strategy targets the host, rather than Mtb, and is intended to augment host responses to infection such that the host is better equipped to prevent or clear infection and resolve chronic inflammation. Metabolic pathways of immune cells have been identified as promising HDT targets as more metabolites and metabolic pathways have shown to play a role in TB pathogenesis and disease progression. Specifically, this review highlights the potential role of lactate as both an immunomodulatory metabolite and a potentially important signaling molecule during the host response to Mtb infection. While long thought to be an inert end product of primarily glucose metabolism, the cancer research field has discovered the importance of lactate in carcinogenesis and resistance to chemotherapeutic drug treatment. Herein, we discuss similarities between the TB granuloma and tumor microenvironments in the context of lactate metabolism and identify key metabolic and signaling pathways that have been shown to play a role in tumor progression but have yet to be explored within the context of TB. Ultimately, lactate metabolism and signaling could be viable HDT targets for TB; however, critical additional research is needed to better understand the role of lactate at the host-pathogen interface during Mtb infection before adopting this HDT strategy.
Collapse
Affiliation(s)
| | - Randall J. Basaraba
- Metabolism of Infectious Diseases Laboratory, Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, United States
| |
Collapse
|
14
|
Glancy B, Kane DA, Kavazis AN, Goodwin ML, Willis WT, Gladden LB. Mitochondrial lactate metabolism: history and implications for exercise and disease. J Physiol 2021; 599:863-888. [PMID: 32358865 PMCID: PMC8439166 DOI: 10.1113/jp278930] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 03/25/2020] [Indexed: 12/31/2022] Open
Abstract
Mitochondrial structures were probably observed microscopically in the 1840s, but the idea of oxidative phosphorylation (OXPHOS) within mitochondria did not appear until the 1930s. The foundation for research into energetics arose from Meyerhof's experiments on oxidation of lactate in isolated muscles recovering from electrical contractions in an O2 atmosphere. Today, we know that mitochondria are actually reticula and that the energy released from electron pairs being passed along the electron transport chain from NADH to O2 generates a membrane potential and pH gradient of protons that can enter the molecular machine of ATP synthase to resynthesize ATP. Lactate stands at the crossroads of glycolytic and oxidative energy metabolism. Based on reported research and our own modelling in silico, we contend that lactate is not directly oxidized in the mitochondrial matrix. Instead, the interim glycolytic products (pyruvate and NADH) are held in cytosolic equilibrium with the products of the lactate dehydrogenase (LDH) reaction and the intermediates of the malate-aspartate and glycerol 3-phosphate shuttles. This equilibrium supplies the glycolytic products to the mitochondrial matrix for OXPHOS. LDH in the mitochondrial matrix is not compatible with the cytoplasmic/matrix redox gradient; its presence would drain matrix reducing power and substantially dissipate the proton motive force. OXPHOS requires O2 as the final electron acceptor, but O2 supply is sufficient in most situations, including exercise and often acute illness. Recent studies suggest that atmospheric normoxia may constitute a cellular hyperoxia in mitochondrial disease. As research proceeds appropriate oxygenation levels should be carefully considered.
Collapse
Affiliation(s)
- Brian Glancy
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Daniel A. Kane
- Department of Human Kinetics, St. Francis Xavier University, NS B2G 2W5, Antigonish, Canada
| | | | - Matthew L. Goodwin
- Department of Orthopaedic Surgery, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Wayne T. Willis
- College of Medicine, Department of Medicine, University of Arizona, Tucson, AZ 85724-5099, USA
| | - L. Bruce Gladden
- School of Kinesiology, Auburn University, Auburn, AL 36849-5323, USA
| |
Collapse
|
15
|
Goodwin ML, Gladden LB, Nijsten MWN. Lactate-Protected Hypoglycemia (LPH). Front Neurosci 2020; 14:920. [PMID: 33013305 PMCID: PMC7497796 DOI: 10.3389/fnins.2020.00920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/10/2020] [Indexed: 11/09/2022] Open
Abstract
Here, we provide an overview of the concept of a lactate-protected hypoglycemia (“LPH”), originally proposed as lowering glucose while simultaneously increasing lactate concentration as a method by which tumors might be targeted. Central to this hypothesis is that lactate can act as a critical salvage fuel for the central nervous system, allowing for wide perturbations in whole body and central nervous system glucose concentrations. Further, many tumors exhibit “the Warburg” effect, consuming glucose and producing and exporting lactate despite adequate oxygenation. While some recent data have provided evidence for a “reverse-Warburg,” where some tumors may preferentially consume lactate, many of these experimental methods rely on a significant elevation in lactate in the tumor microenvironment. To date it remains unclear how various tumors behave in vivo, and how they might respond to perturbations in lactate and glucose concentrations or transport inhibition. By exploiting and targeting lactate transport and metabolism in tumors (with a combination of changes in lactate and glucose concentrations, transport inhibitors, etc.), we can begin developing novel methods for targeting otherwise difficult to treat pathologies in the brain and spinal cord. Here we discuss evidence both experimental and observational, and provide direction for next steps in developing therapies based on these concepts.
Collapse
Affiliation(s)
- Matthew L Goodwin
- Department of Orthopedic Surgery, Washington University in St. Louis, St. Louis, MO, United States
| | - L Bruce Gladden
- School of Kinesiology, Auburn University, Auburn, AL, United States
| | - Maarten W N Nijsten
- Critical Care Department, University Medical Center Groningen, Groningen, Netherlands
| |
Collapse
|
16
|
Ammonium Salts Increase Physical Performance and Reduce Blood Lactate Level in Rats in a Model of Forced Swimming. Bull Exp Biol Med 2020; 168:610-613. [PMID: 32249402 DOI: 10.1007/s10517-020-04762-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Indexed: 02/06/2023]
Abstract
We compared the effects of two doses of ammonium chloride and ammonium carbonate (10 and 20 mg/kg) on the duration of swimming and blood lactate level. Ammonium chloride in a dose of 20 mg/kg was more efficient than in a dose of 10 mg/kg. The efficiency of ammonium carbonate in a dose of 10 mg/kg was similar to that of ammonium chloride in a dose of 20 mg/kg. Increasing the dose of ammonium carbonate to 20 mg/kg led to a decrease in the duration of swimming. On the last day of the experiment, lactate level in 5 min after exhausting load was maximum in control rats, while in rats treated with 10 mg/kg ammonium carbonate and 20 mg/kg ammonium chloride it was lower by 27 and 33%, respectively. In the control group, the amplitude of the decrease in lactate concentration in 1 h after load was 2-fold greater than in the group receiving ammonium chloride in a dose of 20 mg/kg and 1.6-fold greater that in groups treated with ammonium carbonate in a dose of 10 mg/kg and ammonium chloride in a dose of 20 mg/kg.
Collapse
|
17
|
Lynch MA. Can the emerging field of immunometabolism provide insights into neuroinflammation? Prog Neurobiol 2019; 184:101719. [PMID: 31704314 DOI: 10.1016/j.pneurobio.2019.101719] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 10/18/2019] [Accepted: 10/30/2019] [Indexed: 12/29/2022]
Abstract
In the past few years it has become increasingly clear that an understanding of the interaction between metabolism and immune function can provide an insight into cellular responses to challenges. Significant progress has been made in terms of how macrophages are metabolically re-programmed in response to inflammatory stimuli but, to date, little emphasis has been placed on evaluating equivalent changes in microglia. The need to make progress is driven by the fact that, while microglial activation and the cell's ability to adopt an inflammatory phenotype is necessary to fulfil the neuroprotective function of the cell, persistent activation of microglia and the associated neuroinflammation is at the heart of several neurodegenerative diseases. Understanding the metabolic changes that accompany microglial responses may broaden our perspective on how dysfunction might arise and be tempered. This review will evaluate the current literature that addresses the interplay between inflammation and metabolic reprogramming in microglia, reflecting on the parallels that exist with macrophages. It will consider the changes that take place with age including those that have been reported in neurons and astrocytes with the development of non-invasive imaging techniques, and reflect on the literature that is currently available relating to metabolic reprogramming of microglia with age and in neurodegeneration. Finally it will consider the possibility that manipulating microglial metabolism may provide a valuable approach to modulating neuroinflammation.
Collapse
Affiliation(s)
- Marina A Lynch
- Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland.
| |
Collapse
|
18
|
Goodwin ML, Pennington Z, Westbroek EM, Cottrill E, Ahmed AK, Sciubba DM. Lactate and cancer: a "lactatic" perspective on spinal tumor metabolism (part 1). ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:220. [PMID: 31297385 DOI: 10.21037/atm.2019.02.32] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Spine tumors are among the most difficult tumors to treat given their proximity to the spinal cord. Despite advances in adjuvant therapies, surgery remains a critical component of treatment, both in primary tumors and metastatic disease. Given the significant morbidity of these surgeries and with other current adjuvant therapies (e.g., radiation, chemotherapy), interest has grown in other methods of targeting tumors of the spine. Recent efforts have highlighted the tumor microenvironment, and specifically lactate, as central to tumorigenesis. Once erroneously considered a waste product that indicated hypoxia/hypoperfusion, lactate is now known to be at the center of whole-body metabolism, shuttling between tissues and being used as a fuel. Diffusion-driven transporters and the near-equilibrium enzyme lactate dehydrogenase (LDH) allow rapid mobilization of large stores of muscle glycogen in the form of lactate. In times of stress, catecholamines can bind muscle cell receptors and trigger the breakdown of glycogen to lactate, which can then diffuse out into circulation and be used as a fuel where needed. Hypoxia, in contrast, is rarely the reason for an elevated arterial [lactate]. Tumors were originally described in the 1920's as being "glucose-avid" and "lactate-producing" even in normoxia (the "Warburg effect"). We now know that a broad range of metabolic behaviors likely exist, including cancer cells that consume lactate as a fuel, others that may produce it, and still others that may change their behavior based on the local microenvironment. In this review we will examine the relationship between lactate and tumor metabolism with a brief look at spine-specific tumors. Lactate is a valuable fuel and potent signaling molecule that has now been implicated in multiple steps in tumorigenesis [e.g., driving vascular endothelial growth factor (VEGF) expression in normoxia]. Future work should utilize translational animal models to target tumors by altering the local tumor microenvironment, of which lactate is a critical part.
Collapse
Affiliation(s)
- Matthew L Goodwin
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Zach Pennington
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Erick M Westbroek
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ethan Cottrill
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - A Karim Ahmed
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Daniel M Sciubba
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| |
Collapse
|
19
|
Gladden LB. Lactate as a key metabolic intermediate in cancer. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:210. [PMID: 31302666 PMCID: PMC6595195 DOI: 10.21037/atm.2019.01.60] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 01/24/2019] [Indexed: 11/06/2022]
|
20
|
Astrocyte Signaling in the Neurovascular Unit After Central Nervous System Injury. Int J Mol Sci 2019; 20:ijms20020282. [PMID: 30642007 PMCID: PMC6358919 DOI: 10.3390/ijms20020282] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 12/24/2018] [Accepted: 01/07/2019] [Indexed: 12/20/2022] Open
Abstract
Astrocytes comprise the major non-neuronal cell population in the mammalian neurovascular unit. Traditionally, astrocytes are known to play broad roles in central nervous system (CNS) homeostasis, including the management of extracellular ion balance and pH, regulation of neurotransmission, and control of cerebral blood flow and metabolism. After CNS injury, cell–cell signaling between neuronal, glial, and vascular cells contribute to repair and recovery in the neurovascular unit. In this mini-review, we propose the idea that astrocytes play a central role in organizing these signals. During CNS recovery, reactive astrocytes communicate with almost all CNS cells and peripheral progenitors, resulting in the promotion of neurogenesis and angiogenesis, regulation of inflammatory response, and modulation of stem/progenitor response. Reciprocally, changes in neurons and vascular components of the remodeling brain should also influence astrocyte signaling. Therefore, understanding the complex and interdependent signaling pathways of reactive astrocytes after CNS injury may reveal fundamental mechanisms and targets for re-integrating the neurovascular unit and augmenting brain recovery.
Collapse
|
21
|
Gan W, Zhang MX, Wang JX, Fu YP, Huang JL, Yi Y, Jing CY, Fan J, Zhou J, Qiu SJ. Prognostic impact of lactic dehydrogenase to albumin ratio in hepatocellular carcinoma patients with Child-Pugh I who underwent curative resection: a prognostic nomogram study. Cancer Manag Res 2018; 10:5383-5394. [PMID: 30464634 PMCID: PMC6225921 DOI: 10.2147/cmar.s176317] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background Radical resection is the treatment of choice for hepatocellular carcinoma (HCC). However, even with this treatment, HCC prognosis and the efficacy of current predictive models for such patients remain unsatisfactory. Here, we describe an accurate and easy-to-use prognostic index for patients with HCC who have undergone curative resection. Methods The study population comprised of 1,041 patients with HCC who underwent curative resection at Zhongshan Hospital. This population was reduced to 768 patients who were treated in 2012 analyzed as the training cohort and 273 patients treated in 2007 who were used as a validation cohort. Results The lactic dehydrogenase to albumin ratio (LAR) was identified as a significant prognostic index for both overall survival and recurrence-free survival in two independent cohorts. The optimal cutoff value for LAR was determined to be 5.5. The C-index of LAR was superior to other inflammatory scores and serum parameters. This biomarker was also shown to be a stable predictive index in the validation cohort. The new nomogram combining LAR with the Barcelona Clinic Liver Cancer staging system had an improved ability to discriminate overall survival and recurrence-free survival. Nomogram predictions were consistent with observations based on calibration and decisive curve analysis in both independent cohorts. Conclusion LAR is a novel, convenient, reliable, and accurate prognostic predictor in patients with HCC undergoing curative resection. Our results suggest the recommendation of LAR to be used in routine clinical practice.
Collapse
Affiliation(s)
- Wei Gan
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Mei-Xia Zhang
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China, .,Biomedical Research Center, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China,
| | - Jia-Xing Wang
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Yi-Peng Fu
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Jin-Long Huang
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Yong Yi
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Chu-Yu Jing
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Jia Fan
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Jian Zhou
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China,
| | - Shuang-Jian Qiu
- Department of Liver Surgery and Liver Transplantation, Liver Cancer Institute, Zhongshan Hospital and Shanghai Medical School, Fudan University, Key Laboratory for Carcinogenesis and Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China, .,Biomedical Research Center, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China,
| |
Collapse
|
22
|
Yellen G. Fueling thought: Management of glycolysis and oxidative phosphorylation in neuronal metabolism. J Cell Biol 2018; 217:2235-2246. [PMID: 29752396 PMCID: PMC6028533 DOI: 10.1083/jcb.201803152] [Citation(s) in RCA: 213] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 01/02/2023] Open
Abstract
Yellen reviews how cellular metabolism responds acutely to the intense energy requirements of neurons when they are stimulated. The brain’s energy demands are remarkable both in their intensity and in their moment-to-moment dynamic range. This perspective considers the evidence for Warburg-like aerobic glycolysis during the transient metabolic response of the brain to acute activation, and it particularly addresses the cellular mechanisms that underlie this metabolic response. The temporary uncoupling between glycolysis and oxidative phosphorylation led to the proposal of an astrocyte-to-neuron lactate shuttle whereby during stimulation, lactate produced by increased glycolysis in astrocytes is taken up by neurons as their primary energy source. However, direct evidence for this idea is lacking, and evidence rather supports that neurons have the capacity to increase their own glycolysis in response to stimulation; furthermore, neurons may export rather than import lactate in response to stimulation. The possible cellular mechanisms for invoking metabolic resupply of energy in neurons are also discussed, in particular the roles of feedback signaling via adenosine diphosphate and feedforward signaling by calcium ions.
Collapse
Affiliation(s)
- Gary Yellen
- Department of Neurobiology, Harvard Medical School, Boston, MA
| |
Collapse
|
23
|
Bak LK, Walls AB. CrossTalk opposing view: lack of evidence supporting an astrocyte-to-neuron lactate shuttle coupling neuronal activity to glucose utilisation in the brain. J Physiol 2018; 596:351-353. [PMID: 29292507 DOI: 10.1113/jp274945] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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
| | - Anne B Walls
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100, Copenhagen, Denmark
| |
Collapse
|
24
|
Dienel GA, Behar KL, Rothman DL. Cellular Origin of [ 18F]FDG-PET Imaging Signals During Ceftriaxone-Stimulated Glutamate Uptake: Astrocytes and Neurons. Neuroscientist 2017; 24:316-328. [PMID: 29276856 DOI: 10.1177/1073858417749375] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ceftriaxone stimulates astrocytic uptake of the excitatory neurotransmitter glutamate, and it is used to treat glutamatergic excitotoxicity that becomes manifest during many brain diseases. Ceftriaxone-stimulated glutamate transport was reported to drive signals underlying [18F]fluorodeoxyglucose-positron emission tomographic ([18F]FDG-PET) metabolic images of brain glucose utilization and interpreted as supportive of the notion of lactate shuttling from astrocytes to neurons. This study draws attention to critical roles of astrocytes in the energetics and imaging of brain activity, but the results are provocative because (1) the method does not have cellular resolution or provide information about downstream pathways of glucose metabolism, (2) neuronal and astrocytic [18F]FDG uptake were not separately measured, and (3) strong evidence against lactate shuttling was not discussed. Evaluation of potential metabolic responses to ceftriaxone suggests lack of astrocytic specificity and significant contributions by pre- and postsynaptic neuronal compartments. Indeed, astrocytic glycolysis may not make a strong contribution to the [18F]FDG-PET signal because partial or complete oxidation of one glutamate molecule on its uptake generates enough ATP to fuel uptake of 3 to 10 more glutamate molecules, diminishing reliance on glycolysis. The influence of ceftriaxone on energetics of glutamate-glutamine cycling must be determined in astrocytes and neurons to elucidate its roles in excitotoxicity treatment.
Collapse
Affiliation(s)
- Gerald A Dienel
- 1 Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.,2 Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, USA
| | - Kevin L Behar
- 3 Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Douglas L Rothman
- 4 Departments of Radiology and Biomedical Engineering, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
25
|
Nortley R, Attwell D. Control of brain energy supply by astrocytes. Curr Opin Neurobiol 2017; 47:80-85. [PMID: 29054039 DOI: 10.1016/j.conb.2017.09.012] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 09/15/2017] [Accepted: 09/20/2017] [Indexed: 01/03/2023]
Abstract
Astrocytes form an anatomical bridge between the vasculature and neuronal synapses. Recent work suggests that they play a key role in regulating brain energy supply by increasing blood flow to regions where neurons are active, and setting the baseline level of blood flow. Controversy persists over whether lactate derived from astrocyte glycolysis is used to power oxidative phosphorylation in neurons, but astrocytes sustain neuronal ATP production by recycling neurotransmitter glutamate that would otherwise need to be resynthesised from glucose, and by providing a short-term energy store in the form of glycogen that can be mobilised when neurons are active.
Collapse
Affiliation(s)
- Ross Nortley
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower Street, London WC1E 6BT, UK
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
| |
Collapse
|
26
|
Bak LK. Astrocytes take the stage in a tale of signaling-metabolism coupling. J Biol Chem 2017; 292:9439-9440. [PMID: 28576887 DOI: 10.1074/jbc.h117.777243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Astrocytes are crucial cells in the brain that are intimately coupled with neuronal metabolism. A new paper from San Martín et al. provides evidence that physiological levels of the gaseous signal molecule NO can rapidly and reversibly increase astrocyte metabolism of glucose and production of lactate. A proposed neurological coupling-from the potential source of NO, endothelial cells, to the potential beneficiary from the lactate, neurons-prompts new questions regarding the controversial role of lactate in the brain.
Collapse
Affiliation(s)
- Lasse K Bak
- From the Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark
| |
Collapse
|