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Späte E, Zhou B, Sun T, Kusch K, Asadollahi E, Siems SB, Depp C, Werner HB, Saher G, Hirrlinger J, Möbius W, Nave KA, Goebbels S. Downregulated expression of lactate dehydrogenase in adult oligodendrocytes and its implication for the transfer of glycolysis products to axons. Glia 2024; 72:1374-1391. [PMID: 38587131 DOI: 10.1002/glia.24533] [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: 11/04/2023] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/09/2024]
Abstract
Oligodendrocytes and astrocytes are metabolically coupled to neuronal compartments. Pyruvate and lactate can shuttle between glial cells and axons via monocarboxylate transporters. However, lactate can only be synthesized or used in metabolic reactions with the help of lactate dehydrogenase (LDH), a tetramer of LDHA and LDHB subunits in varying compositions. Here we show that mice with a cell type-specific disruption of both Ldha and Ldhb genes in oligodendrocytes lack a pathological phenotype that would be indicative of oligodendroglial dysfunctions or lack of axonal metabolic support. Indeed, when combining immunohistochemical, electron microscopical, and in situ hybridization analyses in adult mice, we found that the vast majority of mature oligodendrocytes lack detectable expression of LDH. Even in neurodegenerative disease models and in mice under metabolic stress LDH was not increased. In contrast, at early development and in the remyelinating brain, LDHA was readily detectable in immature oligodendrocytes. Interestingly, by immunoelectron microscopy LDHA was particularly enriched at gap junctions formed between adjacent astrocytes and at junctions between astrocytes and oligodendrocytes. Our data suggest that oligodendrocytes metabolize lactate during development and remyelination. In contrast, for metabolic support of axons mature oligodendrocytes may export their own glycolysis products as pyruvate rather than lactate. Lacking LDH, these oligodendrocytes can also "funnel" lactate through their "myelinic" channels between gap junction-coupled astrocytes and axons without metabolizing it. We suggest a working model, in which the unequal cellular distribution of LDH in white matter tracts facilitates a rapid and efficient transport of glycolysis products among glial and axonal compartments.
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Affiliation(s)
- Erik Späte
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Baoyu Zhou
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Laboratory of Molecular Neurobiology, Department of Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Ebrahim Asadollahi
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sophie B Siems
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Constanze Depp
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Johannes Hirrlinger
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, Leipzig University, Leipzig, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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2
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Peng CS, Zhang Y, Liu Q, Marti GE, Huang YWA, Südhof TC, Cui B, Chu S. Nanometer-resolution tracking of single cargo reveals dynein motor mechanisms. Nat Chem Biol 2024:10.1038/s41589-024-01694-2. [PMID: 39090313 DOI: 10.1038/s41589-024-01694-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 07/09/2024] [Indexed: 08/04/2024]
Abstract
Cytoplasmic dynein is essential for intracellular transport. Despite extensive in vitro characterizations, how the dynein motors transport vesicles by processive steps in live cells remains unclear. To dissect the molecular mechanisms of dynein, we develop optical probes that enable long-term single-particle tracking in live cells with high spatiotemporal resolution. We find that the number of active dynein motors transporting cargo switches stochastically between one and five dynein motors during long-range transport in neuronal axons. Our very bright optical probes allow the observation of individual molecular steps. Strikingly, these measurements reveal that the dwell times between steps are controlled by two temperature-dependent rate constants in which two ATP molecules are hydrolyzed sequentially during each dynein step. Thus, our observations uncover a previously unknown chemomechanical cycle of dynein-mediated cargo transport in living cells.
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Affiliation(s)
- Chunte Sam Peng
- Department of Physics, Stanford University, Stanford, CA, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Yunxiang Zhang
- Department of Physics, Stanford University, Stanford, CA, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, China
| | - Qian Liu
- Department of Physics, Stanford University, Stanford, CA, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, China
| | - G Edward Marti
- Department of Physics, Stanford University, Stanford, CA, USA
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Yu-Wen Alvin Huang
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI, USA
| | - Thomas C Südhof
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, CA, USA
| | - Steven Chu
- Department of Physics, Stanford University, Stanford, CA, USA.
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA.
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3
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Padamsey Z, Katsanevaki D, Maeso P, Rizzi M, Osterweil EE, Rochefort NL. Sex-specific resilience of neocortex to food restriction. eLife 2024; 12:RP93052. [PMID: 38976495 PMCID: PMC11230624 DOI: 10.7554/elife.93052] [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] [Indexed: 07/10/2024] Open
Abstract
Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing in V1 revealed that in males, but not in females, food restriction significantly modulated canonical, energy-regulating pathways, including pathways associated waith AMP-activated protein kinase, peroxisome proliferator-activated receptor alpha, mammalian target of rapamycin, and oxidative phosphorylation. Moreover, we found that in contrast to males, food restriction in females did not significantly affect V1 ATP usage or visual coding precision (assessed by orientation selectivity). Decreased serum leptin is known to be necessary for triggering energy-saving changes in V1 during food restriction. Consistent with this, we found significantly decreased serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to food restriction.
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Affiliation(s)
- Zahid Padamsey
- Wellcome-MRC Institute of Metabolic Science, University of CambridgeCambridgeUnited Kingdom
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Danai Katsanevaki
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of EdinburghEdinburghUnited Kingdom
- Simons Initiative for the Developing Brain, University of EdinburghEdinburghUnited Kingdom
| | - Patricia Maeso
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Manuela Rizzi
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Emily E Osterweil
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of EdinburghEdinburghUnited Kingdom
- Simons Initiative for the Developing Brain, University of EdinburghEdinburghUnited Kingdom
- Rosamund Stone Zander Translational Neuroscience Center, F.M. Kirby Center, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Nathalie L Rochefort
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of EdinburghEdinburghUnited Kingdom
- Simons Initiative for the Developing Brain, University of EdinburghEdinburghUnited Kingdom
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4
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Tancreda G, Ravera S, Panfoli I. Exploring the Therapeutic Potential: Bioactive Molecules and Dietary Interventions in Multiple Sclerosis Management. Curr Issues Mol Biol 2024; 46:5595-5613. [PMID: 38921006 PMCID: PMC11202103 DOI: 10.3390/cimb46060335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/27/2024] Open
Abstract
Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease of the central nervous system, the etiology of which is still unclear. Its hallmarks are inflammation and axonal damage. As a disease primarily impacting younger individuals, the social cost of MS is high. It has been proposed that environmental factors, smoking, and dietary habits acting on a genetic susceptibility play a role in MS. Recent studies indicate that diet can significantly influence the onset and progression of MS. This review delves into the impact of natural bioactive molecules on MS development and explores the dietary interventions that hold promise in managing the disease. Dietary patterns, including ketogenic and Mediterranean diets, are discussed. Theories about the potential mechanistic associations beneath the noted effects are also proposed. Several dietary components and patterns demonstrated the potential for a significant impact on MS. However, extensive prospective clinical trials are necessary to fully understand the role of natural bioactive molecules as disease modifiers in MS.
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Affiliation(s)
- Gabriele Tancreda
- Department of Experimental Medicine, University of Genoa, 16132 Genoa, Italy
| | - Silvia Ravera
- Department of Experimental Medicine, University of Genoa, 16132 Genoa, Italy
| | - Isabella Panfoli
- Department of Pharmacy (DIFAR), University of Genoa, 16132 Genoa, Italy
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5
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Koveal D. Functional principles of genetically encoded fluorescent biosensors for metabolism and their quantitative use. J Neurochem 2024; 168:496-505. [PMID: 37314388 DOI: 10.1111/jnc.15878] [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: 04/18/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023]
Abstract
Genetically encoded fluorescent biosensors provide an attractive means of measuring chemical changes in single cells on fast timescales (milliseconds to seconds). While their most prominent application has been in tracking neural activity and neurotransmitter release, there has been growing interest in developing and deploying new versions of these tools to study brain metabolism. However, the careful use of these tools and the interpretation of the data they provide remain challenging. Many biosensors are subject to interferences that can alter sensor responses within a single cell or between cells, producing ambiguous results. This presents a challenge for quantitation and for our ability to accurately interpret sensor responses. This review describes current methods of sensor quantitation, with a focus on cellular interferences that commonly affect sensor performance, ways to avoid false inferences, and recent advances in sensor optimization to make them more robust.
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Affiliation(s)
- Dorothy Koveal
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, Georgia, USA
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6
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Peper CJ, Kilgore MD, Jiang Y, Xiu Y, Xia W, Wang Y, Shi M, Zhou D, Dumont AS, Wang X, Liu N. Tracing the path of disruption: 13C isotope applications in traumatic brain injury-induced metabolic dysfunction. CNS Neurosci Ther 2024; 30:e14693. [PMID: 38544365 PMCID: PMC10973562 DOI: 10.1111/cns.14693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 02/25/2024] [Accepted: 03/12/2024] [Indexed: 05/14/2024] Open
Abstract
Cerebral metabolic dysfunction is a critical pathological hallmark observed in the aftermath of traumatic brain injury (TBI), as extensively documented in clinical investigations and experimental models. An in-depth understanding of the bioenergetic disturbances that occur following TBI promises to reveal novel therapeutic targets, paving the way for the timely development of interventions to improve patient outcomes. The 13C isotope tracing technique represents a robust methodological advance, harnessing biochemical quantification to delineate the metabolic trajectories of isotopically labeled substrates. This nuanced approach enables real-time mapping of metabolic fluxes, providing a window into the cellular energetic state and elucidating the perturbations in key metabolic circuits. By applying this sophisticated tool, researchers can dissect the complexities of bioenergetic networks within the central nervous system, offering insights into the metabolic derangements specific to TBI pathology. Embraced by both animal studies and clinical research, 13C isotope tracing has bolstered our understanding of TBI-induced metabolic dysregulation. This review synthesizes current applications of isotope tracing and its transformative potential in evaluating and addressing the metabolic sequelae of TBI.
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Affiliation(s)
- Charles J. Peper
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Mitchell D. Kilgore
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yinghua Jiang
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yuwen Xiu
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Winna Xia
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Yingjie Wang
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Mengxuan Shi
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Di Zhou
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Aaron S. Dumont
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
| | - Xiaoying Wang
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
- Neuroscience Program, Tulane Brain InstituteTulane UniversityNew OrleansLouisianaUSA
| | - Ning Liu
- Clinical Neuroscience Research Center, Departments of Neurosurgery and NeurologyTulane University School of MedicineNew OrleansLouisianaUSA
- Neuroscience Program, Tulane Brain InstituteTulane UniversityNew OrleansLouisianaUSA
- Tulane University Translational Sciences InstituteNew OrleansLouisianaUSA
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7
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Fenelon KD, Krause J, Koromila T. Opticool: Cutting-edge transgenic optical tools. PLoS Genet 2024; 20:e1011208. [PMID: 38517915 PMCID: PMC10959397 DOI: 10.1371/journal.pgen.1011208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2024] Open
Abstract
Only a few short decades have passed since the sequencing of GFP, yet the modern repertoire of transgenically encoded optical tools implies an exponential proliferation of ever improving constructions to interrogate the subcellular environment. A myriad of tags for labeling proteins, RNA, or DNA have arisen in the last few decades, facilitating unprecedented visualization of subcellular components and processes. Development of a broad array of modern genetically encoded sensors allows real-time, in vivo detection of molecule levels, pH, forces, enzyme activity, and other subcellular and extracellular phenomena in ever expanding contexts. Optogenetic, genetically encoded optically controlled manipulation systems have gained traction in the biological research community and facilitate single-cell, real-time modulation of protein function in vivo in ever broadening, novel applications. While this field continues to explosively expand, references are needed to assist scientists seeking to use and improve these transgenic devices in new and exciting ways to interrogate development and disease. In this review, we endeavor to highlight the state and trajectory of the field of in vivo transgenic optical tools.
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Affiliation(s)
- Kelli D. Fenelon
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Julia Krause
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Theodora Koromila
- Department of Biology, University of Texas at Arlington, Arlington, Texas, United States of America
- School of Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece
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8
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Looser ZJ, Faik Z, Ravotto L, Zanker HS, Jung RB, Werner HB, Ruhwedel T, Möbius W, Bergles DE, Barros LF, Nave KA, Weber B, Saab AS. Oligodendrocyte-axon metabolic coupling is mediated by extracellular K + and maintains axonal health. Nat Neurosci 2024; 27:433-448. [PMID: 38267524 PMCID: PMC10917689 DOI: 10.1038/s41593-023-01558-3] [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: 11/08/2022] [Accepted: 12/13/2023] [Indexed: 01/26/2024]
Abstract
The integrity of myelinated axons relies on homeostatic support from oligodendrocytes (OLs). To determine how OLs detect axonal spiking and how rapid axon-OL metabolic coupling is regulated in the white matter, we studied activity-dependent calcium (Ca2+) and metabolite fluxes in the mouse optic nerve. We show that fast axonal spiking triggers Ca2+ signaling and glycolysis in OLs. OLs detect axonal activity through increases in extracellular potassium (K+) concentrations and activation of Kir4.1 channels, thereby regulating metabolite supply to axons. Both pharmacological inhibition and OL-specific inactivation of Kir4.1 reduce the activity-induced axonal lactate surge. Mice lacking oligodendroglial Kir4.1 exhibit lower resting lactate levels and altered glucose metabolism in axons. These early deficits in axonal energy metabolism are associated with late-onset axonopathy. Our findings reveal that OLs detect fast axonal spiking through K+ signaling, making acute metabolic coupling possible and adjusting the axon-OL metabolic unit to promote axonal health.
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Affiliation(s)
- Zoe J Looser
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Zainab Faik
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Luca Ravotto
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Henri S Zanker
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dwight E Bergles
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - L Felipe Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Bruno Weber
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland.
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9
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Brüll M, Geese N, Celardo I, Laumann M, Leist M. Preparation of Viable Human Neurites for Neurobiological and Neurodegeneration Studies. Cells 2024; 13:242. [PMID: 38334634 PMCID: PMC10854604 DOI: 10.3390/cells13030242] [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: 12/21/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024] Open
Abstract
Few models allow the study of neurite damage in the human central nervous system. We used here dopaminergic LUHMES neurons to establish a culture system that allows for (i) the observation of highly enriched neurites, (ii) the preparation of the neurite fraction for biochemical studies, and (iii) the measurement of neurite markers and metabolites after axotomy. LUHMES-based spheroids, plated in culture dishes, extended neurites of several thousand µm length, while all somata remained aggregated. These cultures allowed an easy microscopic observation of live or fixed neurites. Neurite-only cultures (NOC) were produced by cutting out the still-aggregated somata. The potential application of such cultures was exemplified by determinations of their protein and RNA contents. For instance, the mitochondrial TOM20 protein was highly abundant, while nuclear histone H3 was absent. Similarly, mitochondrial-encoded RNAs were found at relatively high levels, while the mRNA for a histone or the neuronal nuclear marker NeuN (RBFOX3) were relatively depleted in NOC. Another potential use of NOC is the study of neurite degeneration. For this purpose, an algorithm to quantify neurite integrity was developed. Using this tool, we found that the addition of nicotinamide drastically reduced neurite degeneration. Also, the chelation of Ca2+ in NOC delayed the degeneration, while inhibitors of calpains had no effect. Thus, NOC proved to be suitable for biochemical analysis and for studying degeneration processes after a defined cut injury.
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Affiliation(s)
- Markus Brüll
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Nils Geese
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Ivana Celardo
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Michael Laumann
- Electron Microscopy Centre, University of Konstanz, 78457 Konstanz, Germany;
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
- Center for Alternatives to Animal Testing in Europe (CAAT-Europe), University of Konstanz, 78457 Konstanz, Germany
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10
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Nave KA, Asadollahi E, Sasmita A. Expanding the function of oligodendrocytes to brain energy metabolism. Curr Opin Neurobiol 2023; 83:102782. [PMID: 37703600 DOI: 10.1016/j.conb.2023.102782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 09/15/2023]
Abstract
Oligodendrocytes are best known for wrapping myelin, a unique specialization that enables energy-efficient and fast axonal impulse propagation in white matter tracts and fibers of the cortical circuitry. However, myelinating oligodendrocytes have additional metabolic functions that are only gradually understood, including the regulated release of pyruvate/lactate and extracellular vesicles, both of which are in support of the axonal energy balance. The axon-supportive functions of glial cells are older than myelin in nervous system evolution and implicate oligodendrocyte dysfunction and loss of myelin integrity as a risk factor for progressive neurodegeneration in brain diseases.
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Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen.
| | - Ebrahim Asadollahi
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen. https://twitter.com/EbrahimAsadoll3
| | - Andrew Sasmita
- Department of Neurogenetics, Max Planck Institute of Multidisciplinary Sciences, Göttingen. https://twitter.com/AOSasmita
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Ehrenreich H, Gassmann M, Poustka L, Burtscher M, Hammermann P, Sirén AL, Nave KA, Miskowiak K. Exploiting moderate hypoxia to benefit patients with brain disease: Molecular mechanisms and translational research in progress. NEUROPROTECTION 2023; 1:9-19. [PMID: 37671067 PMCID: PMC7615021 DOI: 10.1002/nep3.15] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/17/2022] [Indexed: 09/07/2023]
Abstract
Hypoxia is increasingly recognized as an important physiological driving force. A specific transcriptional program, induced by a decrease in oxygen (O2) availability, for example, inspiratory hypoxia at high altitude, allows cells to adapt to lower O2 and limited energy metabolism. This transcriptional program is partly controlled by and partly independent of hypoxia-inducible factors. Remarkably, this same transcriptional program is stimulated in the brain by extensive motor-cognitive exercise, leading to a relative decrease in O2 supply, compared to the acutely augmented O2 requirement. We have coined the term "functional hypoxia" for this important demand-responsive, relative reduction in O2 availability. Functional hypoxia seems to be critical for enduring adaptation to higher physiological challenge that includes substantial "brain hardware upgrade," underlying advanced performance. Hypoxia-induced erythropoietin expression in the brain likely plays a decisive role in these processes, which can be imitated by recombinant human erythropoietin treatment. This article review presents hints of how inspiratory O2 manipulations can potentially contribute to enhanced brain function. It thereby provides the ground for exploiting moderate inspiratory plus functional hypoxia to treat individuals with brain disease. Finally, it sketches a planned multistep pilot study in healthy volunteers and first patients, about to start, aiming at improved performance upon motor-cognitive training under inspiratory hypoxia.
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Affiliation(s)
- Hannelore Ehrenreich
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Max Gassmann
- Institute of Veterinary Physiology and Zürich Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland
| | - Luise Poustka
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Martin Burtscher
- Faculty of Sports Science, University of Innsbruck, Innsbruck, Austria
| | | | - Anna-Leena Sirén
- Departments of Neurophysiology and Neurosurgery, University of Würzburg, Würzburg, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Kamilla Miskowiak
- Psychiatric Centre, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
- Department of Psychology, University of Copenhagen, Copenhagen, Denmark
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12
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Tai YH, Engels D, Locatelli G, Emmanouilidis I, Fecher C, Theodorou D, Müller SA, Licht-Mayer S, Kreutzfeldt M, Wagner I, de Mello NP, Gkotzamani SN, Trovò L, Kendirli A, Aljović A, Breckwoldt MO, Naumann R, Bareyre FM, Perocchi F, Mahad D, Merkler D, Lichtenthaler SF, Kerschensteiner M, Misgeld T. Targeting the TCA cycle can ameliorate widespread axonal energy deficiency in neuroinflammatory lesions. Nat Metab 2023; 5:1364-1381. [PMID: 37430025 PMCID: PMC10447243 DOI: 10.1038/s42255-023-00838-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 06/05/2023] [Indexed: 07/12/2023]
Abstract
Inflammation in the central nervous system can impair the function of neuronal mitochondria and contributes to axon degeneration in the common neuroinflammatory disease multiple sclerosis (MS). Here we combine cell-type-specific mitochondrial proteomics with in vivo biosensor imaging to dissect how inflammation alters the molecular composition and functional capacity of neuronal mitochondria. We show that neuroinflammatory lesions in the mouse spinal cord cause widespread and persisting axonal ATP deficiency, which precedes mitochondrial oxidation and calcium overload. This axonal energy deficiency is associated with impaired electron transport chain function, but also an upstream imbalance of tricarboxylic acid (TCA) cycle enzymes, with several, including key rate-limiting, enzymes being depleted in neuronal mitochondria in experimental models and in MS lesions. Notably, viral overexpression of individual TCA enzymes can ameliorate the axonal energy deficits in neuroinflammatory lesions, suggesting that TCA cycle dysfunction in MS may be amendable to therapy.
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Affiliation(s)
- Yi-Heng Tai
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Daniel Engels
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
| | - Giuseppe Locatelli
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
- Novartis Institutes for BioMedical Research (NIBR), Basel, Switzerland
| | - Ioanna Emmanouilidis
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Caroline Fecher
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Department of Cell Biology and Physiology, Washington University in St Louis, St. Louis, MO, USA
| | - Delphine Theodorou
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
| | - Stephan A Müller
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Simon Licht-Mayer
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Mario Kreutzfeldt
- Department of Pathology and Immunology, Division of Clinical Pathology, University & University Hospitals of Geneva, Geneva, Switzerland
| | - Ingrid Wagner
- Department of Pathology and Immunology, Division of Clinical Pathology, University & University Hospitals of Geneva, Geneva, Switzerland
| | | | - Sofia-Natsouko Gkotzamani
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
| | - Laura Trovò
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Arek Kendirli
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
| | - Almir Aljović
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
| | - Michael O Breckwoldt
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Department of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Ronald Naumann
- Transgenic Core Facility, Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Florence M Bareyre
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Fabiana Perocchi
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Don Mahad
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Doron Merkler
- Department of Pathology and Immunology, Division of Clinical Pathology, University & University Hospitals of Geneva, Geneva, Switzerland
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität (LMU) München, Munich, Germany.
- Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Martinsried, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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13
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Pape N, Rose CR. Activation of TRPV4 channels promotes the loss of cellular ATP in organotypic slices of the mouse neocortex exposed to chemical ischemia. J Physiol 2023; 601:2975-2990. [PMID: 37195195 DOI: 10.1113/jp284430] [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: 03/14/2023] [Accepted: 05/15/2023] [Indexed: 05/18/2023] Open
Abstract
The vertebrate brain has an exceptionally high energy need. During ischemia, intracellular ATP concentrations decline rapidly, resulting in the breakdown of ion gradients and cellular damage. Here, we employed the nanosensor ATeam1.03YEMK to analyse the pathways driving the loss of ATP upon transient metabolic inhibition in neurons and astrocytes of the mouse neocortex. We demonstrate that brief chemical ischemia, induced by combined inhibition of glycolysis and oxidative phosphorylation, results in a transient decrease in intracellular ATP. Neurons experienced a larger relative decline and showed less ability to recover from prolonged (>5 min) metabolic inhibition than astrocytes. Blocking voltage-gated Na+ channels or NMDA receptors ameliorated the ATP decline in neurons and astrocytes, while blocking glutamate uptake aggravated the overall reduction in neuronal ATP, confirming the central role of excitatory neuronal activity in the cellular energy loss. Unexpectedly, pharmacological inhibition of transient receptor potential vanilloid 4 (TRPV4) channels significantly reduced the ischemia-induced decline in ATP in both cell types. Imaging with Na+ -sensitive indicator dye ING-2 furthermore showed that TRPV4 inhibition also reduced ischemia-induced increases in intracellular Na+ . Altogether, our results demonstrate that neurons exhibit a higher vulnerability to brief metabolic inhibition than astrocytes. Moreover, they reveal an unexpected strong contribution of TRPV4 channels to the loss of cellular ATP and suggest that the demonstrated TRPV4-related ATP consumption is most likely a direct consequence of Na+ influx. Activation of TRPV4 channels thus provides a hitherto unacknowledged contribution to the cellular energy loss during energy failure, generating a significant metabolic cost in ischemic conditions. KEY POINTS: In the ischemic brain, cellular ATP concentrations decline rapidly, which results in the collapse of ion gradients and promotes cellular damage and death. We analysed the pathways driving the loss of ATP upon transient metabolic inhibition in neurons and astrocytes of the mouse neocortex. Our results confirm the central role of excitatory neuronal activity in the cellular energy loss and demonstrate that neurons experience a larger decline in ATP and are more vulnerable to brief metabolic stress than astrocytes. Our study also reveals a new, previously unknown involvement of osmotically activated transient receptor potential vanilloid 4 (TRPV4) channels to the reduction in cellular ATP in both cell types and indicates that this is a consequence of TRPV4-mediated Na+ influx. We conclude that activation of TRPV4 channels provides a considerable contribution to the cellular energy loss, thereby generating a significant metabolic cost in ischemic conditions.
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Affiliation(s)
- Nils Pape
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, Düsseldorf, Germany
| | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Universitätsstraße 1, Düsseldorf, Germany
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14
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Barros LF, Ruminot I, Sandoval PY, San Martín A. Enlightening brain energy metabolism. Neurobiol Dis 2023:106211. [PMID: 37352985 DOI: 10.1016/j.nbd.2023.106211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/06/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023] Open
Abstract
Brain tissue metabolism is distributed across several cell types and subcellular compartments, which activate at different times and with different temporal patterns. The introduction of genetically-encoded fluorescent indicators that are imaged using time-lapse microscopy has opened the possibility of studying brain metabolism at cellular and sub-cellular levels. There are indicators for sugars, monocarboxylates, Krebs cycle intermediates, amino acids, cofactors, and energy nucleotides, which inform about relative levels, concentrations and fluxes. This review offers a brief survey of the metabolic indicators that have been validated in brain cells, with some illustrative examples from the literature. Whereas only a small fraction of the metabolome is currently accessible to fluorescent probes, there are grounds to be optimistic about coming developments and the application of these tools to the study of brain disease.
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Affiliation(s)
- L F Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Medicina y Ciencia, Universidad San Sebastián, Valdivia, Chile.
| | - I Ruminot
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Ciencias para el Cuidado de La Salud, Universidad San Sebastián, Valdivia, Chile
| | - P Y Sandoval
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Ciencias para el Cuidado de La Salud, Universidad San Sebastián, Valdivia, Chile
| | - A San Martín
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Facultad de Ciencias para el Cuidado de La Salud, Universidad San Sebastián, Valdivia, Chile
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15
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Li S, Sheng ZH. Oligodendrocyte-derived transcellular signaling regulates axonal energy metabolism. Curr Opin Neurobiol 2023; 80:102722. [PMID: 37028201 PMCID: PMC10225329 DOI: 10.1016/j.conb.2023.102722] [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: 11/22/2022] [Revised: 02/28/2023] [Accepted: 03/07/2023] [Indexed: 04/08/2023]
Abstract
The unique morphology and functionality of central nervous system (CNS) neurons necessitate specialized mechanisms to maintain energy metabolism throughout long axons and extensive terminals. Oligodendrocytes (OLs) enwrap CNS axons with myelin sheaths in a multilamellar fashion. Apart from their well-established function in action potential propagation, OLs also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes consisting of proteins, lipids, and RNAs. OL-derived metabolic support is crucial for the maintenance of axonal integrity; its dysfunction has emerged as an important player in neurological disorders that are associated with axonal energy deficits and degeneration. In this review, we discuss recent advances in how these transcellular signaling pathways maintain axonal energy metabolism in health and neurological disorders.
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Affiliation(s)
- Sunan Li
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA. https://twitter.com/@sunan_li
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA.
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16
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Arinrad S, Depp C, Siems SB, Sasmita AO, Eichel MA, Ronnenberg A, Hammerschmidt K, Lüders KA, Werner HB, Ehrenreich H, Nave KA. Isolated catatonia-like executive dysfunction in mice with forebrain-specific loss of myelin integrity. eLife 2023; 12:70792. [PMID: 36892455 PMCID: PMC9998085 DOI: 10.7554/elife.70792] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 01/24/2023] [Indexed: 03/10/2023] Open
Abstract
A key feature of advanced brain aging includes structural defects of intracortical myelin that are associated with secondary neuroinflammation. A similar pathology is seen in specific myelin mutant mice that model 'advanced brain aging' and exhibit a range of behavioral abnormalities. However, the cognitive assessment of these mutants is problematic because myelin-dependent motor-sensory functions are required for quantitative behavioral readouts. To better understand the role of cortical myelin integrity for higher brain functions, we generated mice lacking Plp1, encoding the major integral myelin membrane protein, selectively in ventricular zone stem cells of the mouse forebrain. In contrast to conventional Plp1 null mutants, subtle myelin defects were restricted to the cortex, hippocampus, and underlying callosal tracts. Moreover, forebrain-specific Plp1 mutants exhibited no defects of basic motor-sensory performance at any age tested. Surprisingly, several behavioral alterations reported for conventional Plp1 null mice (Gould et al., 2018) were absent and even social interactions appeared normal. However, with novel behavioral paradigms, we determined catatonia-like symptoms and isolated executive dysfunction in both genders. This suggests that loss of myelin integrity has an impact on cortical connectivity and underlies specific defects of executive function. These observations are likewise relevant for human neuropsychiatric conditions and other myelin-related diseases.
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Affiliation(s)
- Sahab Arinrad
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Constanze Depp
- Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sophie B Siems
- Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | | | - Maria A Eichel
- Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Anja Ronnenberg
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | | | - Katja A Lüders
- Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hauke B Werner
- Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Hannelore Ehrenreich
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Klaus-Armin Nave
- Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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17
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Yang Z, Yu Z, Xiao B. Coordinated Regulation of Myelination by Growth Factor and Amino-acid Signaling Pathways. Neurosci Bull 2023; 39:453-465. [PMID: 36352321 PMCID: PMC10043148 DOI: 10.1007/s12264-022-00967-x] [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: 03/11/2022] [Accepted: 06/27/2022] [Indexed: 11/11/2022] Open
Abstract
Myelin-forming oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) are essential for structural and functional homeostasis of nervous tissue. Albeit with certain similarities, the regulation of CNS and PNS myelination is executed differently. Recent advances highlight the coordinated regulation of oligodendrocyte myelination by amino-acid sensing and growth factor signaling pathways. In this review, we discuss novel insights into the understanding of differential regulation of oligodendrocyte and Schwann cell biology in CNS and PNS myelination, with particular focus on the roles of growth factor-stimulated RHEB-mTORC1 and GATOR2-mediated amino-acid sensing/signaling pathways. We also discuss recent progress on the metabolic regulation of oligodendrocytes and Schwann cells and the impact of their dysfunction on neuronal function and disease.
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Affiliation(s)
- Zhiwen Yang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Zongyan Yu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China.
| | - Bo Xiao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, 518000, China.
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18
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Köhler S, Winkler U, Junge T, Lippmann K, Eilers J, Hirrlinger J. Gray and white matter astrocytes differ in basal metabolism but respond similarly to neuronal activity. Glia 2023; 71:229-244. [PMID: 36063073 DOI: 10.1002/glia.24268] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/12/2022] [Accepted: 08/22/2022] [Indexed: 11/10/2022]
Abstract
Astrocytes are a heterogeneous population of glial cells in the brain, which adapt their properties to the requirements of the local environment. Two major groups of astrocytes are protoplasmic astrocytes residing in gray matter as well as fibrous astrocytes of white matter. Here, we compared the energy metabolism of astrocytes in the cortex and corpus callosum as representative gray matter and white matter regions, in acute brain slices taking advantage of genetically encoded fluorescent nanosensors for the NADH/NAD+ redox ratio and for ATP. Astrocytes of the corpus callosum presented a more reduced basal NADH/NAD+ redox ratio, and a lower cytosolic concentration of ATP compared to cortical astrocytes. In cortical astrocytes, the neurotransmitter glutamate and increased extracellular concentrations of K+ , typical correlates of neuronal activity, induced a more reduced NADH/NAD+ redox ratio. While application of glutamate decreased [ATP], K+ as well as the combination of glutamate and K+ resulted in an increase of ATP levels. Strikingly, a very similar regulation of metabolism by K+ and glutamate was observed in astrocytes in the corpus callosum. Finally, strong intrinsic neuronal activity provoked by application of bicuculline and withdrawal of Mg2+ caused a shift of the NADH/NAD+ redox ratio to a more reduced state as well as a slight reduction of [ATP] in gray and white matter astrocytes. In summary, the metabolism of astrocytes in cortex and corpus callosum shows distinct basal properties, but qualitatively similar responses to neuronal activity, probably reflecting the different environment and requirements of these brain regions.
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Affiliation(s)
- Susanne Köhler
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Ulrike Winkler
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Tabea Junge
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Kristina Lippmann
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Jens Eilers
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany
| | - Johannes Hirrlinger
- Faculty of Medicine, Carl-Ludwig-Institute for Physiology, Leipzig University, Leipzig, Germany.,Department of Neurogenetics, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
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19
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Natsubori A, Hirai S, Kwon S, Ono D, Deng F, Wan J, Miyazawa M, Kojima T, Okado H, Karashima A, Li Y, Tanaka KF, Honda M. Serotonergic neurons control cortical neuronal intracellular energy dynamics by modulating astrocyte-neuron lactate shuttle. iScience 2023; 26:105830. [PMID: 36713262 PMCID: PMC9881222 DOI: 10.1016/j.isci.2022.105830] [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: 02/13/2022] [Revised: 08/15/2022] [Accepted: 12/12/2022] [Indexed: 01/07/2023] Open
Abstract
The central serotonergic system has multiple roles in animal physiology and behavior, including sleep-wake control. However, its function in controlling brain energy metabolism according to the state of animals remains undetermined. Through in vivo monitoring of energy metabolites and signaling, we demonstrated that optogenetic activation of raphe serotonergic neurons increased cortical neuronal intracellular concentration of ATP, an indispensable cellular energy molecule, which was suppressed by inhibiting neuronal uptake of lactate derived from astrocytes. Raphe serotonergic neuronal activation induced cortical astrocytic Ca2+ and cAMP surges and increased extracellular lactate concentrations, suggesting the facilitation of lactate release from astrocytes. Furthermore, chemogenetic inhibition of raphe serotonergic neurons partly attenuated the increase in cortical neuronal intracellular ATP levels as arousal increased in mice. Serotonergic neuronal activation promoted an increase in cortical neuronal intracellular ATP levels, partly mediated by the facilitation of the astrocyte-neuron lactate shuttle, contributing to state-dependent optimization of neuronal intracellular energy levels.
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Affiliation(s)
- Akiyo Natsubori
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan,Corresponding author
| | - Shinobu Hirai
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Soojin Kwon
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Daisuke Ono
- Department of Neuroscience Ⅱ, Research Institute of Environmental Medicine, Nagoya University, Nagoya 464-8601, Japan,Department of Neural Regulation, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Fei Deng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China,PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Jinxia Wan
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China,PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Momoka Miyazawa
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan,Faculty of Science Division Ⅱ, Tokyo University of Science, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Takashi Kojima
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Haruo Okado
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
| | - Akihiro Karashima
- Department of Electronics, Graduate School of Engineering, Tohoku Institute of Technology, Sendai 982-8577, Japan
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing 100871, China,PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
| | - Kenji F. Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Makoto Honda
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo 156-8506, Japan
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20
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Paclitaxel Inhibits KCNQ Channels in Primary Sensory Neurons to Initiate the Development of Painful Peripheral Neuropathy. Cells 2022; 11:cells11244067. [PMID: 36552832 PMCID: PMC9776748 DOI: 10.3390/cells11244067] [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: 11/29/2022] [Revised: 12/11/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Cancer patients undergoing paclitaxel infusion usually experience peripheral nerve degeneration and serious neuropathic pain termed paclitaxel-induced peripheral neuropathy (PIPN). However, alterations in the dose or treatment schedule for paclitaxel do not eliminate PIPN, and no therapies are available for PIPN, despite numerous studies to uncover the mechanisms underlying the development/maintenance of this condition. Therefore, we aimed to uncover a novel mechanism underlying the pathogenesis of PIPN. Clinical studies suggest that acute over excitation of primary sensory neurons is linked to the pathogenesis of PIPN. We found that paclitaxel-induced acute hyperexcitability of primary sensory neurons results from the paclitaxel-induced inhibition of KCNQ potassium channels (mainly KCNQ2), found abundantly in sensory neurons and axons. We found that repeated application of XE-991, a specific KCNQ channel blocker, induced PIPN-like alterations in rats, including mechanical hypersensitivity and degeneration of peripheral nerves, as detected by both morphological and behavioral assays. In contrast, genetic deletion of KCNQ2 from peripheral sensory neurons in mice significantly attenuated the development of paclitaxel-induced peripheral sensory fiber degeneration and chronic pain. These findings may lead to a better understanding of the causes of PIPN and provide an impetus for developing new classes of KCNQ activators for its therapeutic treatment.
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21
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Dembitskaya Y, Piette C, Perez S, Berry H, Magistretti PJ, Venance L. Lactate supply overtakes glucose when neural computational and cognitive loads scale up. Proc Natl Acad Sci U S A 2022; 119:e2212004119. [PMID: 36375086 PMCID: PMC9704697 DOI: 10.1073/pnas.2212004119] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 10/10/2022] [Indexed: 07/23/2023] Open
Abstract
Neural computational power is determined by neuroenergetics, but how and which energy substrates are allocated to various forms of memory engram is unclear. To solve this question, we asked whether neuronal fueling by glucose or lactate scales differently upon increasing neural computation and cognitive loads. Here, using electrophysiology, two-photon imaging, cognitive tasks, and mathematical modeling, we show that both glucose and lactate are involved in engram formation, with lactate supporting long-term synaptic plasticity evoked by high-stimulation load activity patterns and high attentional load in cognitive tasks and glucose being sufficient for less demanding neural computation and learning tasks. Indeed, we show that lactate is mandatory for demanding neural computation, such as theta-burst stimulation, while glucose is sufficient for lighter forms of activity-dependent long-term potentiation (LTP), such as spike timing-dependent plasticity (STDP). We find that subtle variations of spike number or frequency in STDP are sufficient to shift the on-demand fueling from glucose to lactate. Finally, we demonstrate that lactate is necessary for a cognitive task requiring high attentional load, such as the object-in-place task, and for the corresponding in vivo hippocampal LTP expression but is not needed for a less demanding task, such as a simple novel object recognition. Overall, these results demonstrate that glucose and lactate metabolism are differentially engaged in neuronal fueling depending on the complexity of the activity-dependent plasticity and behavior.
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Affiliation(s)
- Yulia Dembitskaya
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Charlotte Piette
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Sylvie Perez
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, 75005 Paris, France
| | - Hugues Berry
- AIStroSight Lab, INRIA, Hospices Civils de Lyon, Université Claude Bernard Lyon 1, 69603 Villeurbanne, France
- University of Lyon, LIRIS UMR5205, 69622 Villeurbanne, France
| | - Pierre J. Magistretti
- Biological and Environmental Sciences and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), 23955-6900 Thuwal, Saudi Arabia
- Brain Mind Institute, EPFL, 1015 Lausanne, Switzerland
| | - Laurent Venance
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, 75005 Paris, France
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22
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A new mouse model of Charcot-Marie-Tooth 2J neuropathy replicates human axonopathy and suggest alteration in axo-glia communication. PLoS Genet 2022; 18:e1010477. [DOI: 10.1371/journal.pgen.1010477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 11/29/2022] [Accepted: 10/13/2022] [Indexed: 11/10/2022] Open
Abstract
Myelin is essential for rapid nerve impulse propagation and axon protection. Accordingly, defects in myelination or myelin maintenance lead to secondary axonal damage and subsequent degeneration. Studies utilizing genetic (CNPase-, MAG-, and PLP-null mice) and naturally occurring neuropathy models suggest that myelinating glia also support axons independently from myelin. Myelin protein zero (MPZ or P0), which is expressed only by Schwann cells, is critical for myelin formation and maintenance in the peripheral nervous system. Many mutations in MPZ are associated with demyelinating neuropathies (Charcot-Marie-Tooth disease type 1B [CMT1B]). Surprisingly, the substitution of threonine by methionine at position 124 of P0 (P0T124M) causes axonal neuropathy (CMT2J) with little to no myelin damage. This disease provides an excellent paradigm to understand how myelinating glia support axons independently from myelin. To study this, we generated targeted knock-in MpzT124M mutant mice, a genetically authentic model of T124M-CMT2J neuropathy. Similar to patients, these mice develop axonopathy between 2 and 12 months of age, characterized by impaired motor performance, normal nerve conduction velocities but reduced compound motor action potential amplitudes, and axonal damage with only minor compact myelin modifications. Mechanistically, we detected metabolic changes that could lead to axonal degeneration, and prominent alterations in non-compact myelin domains such as paranodes, Schmidt-Lanterman incisures, and gap junctions, implicated in Schwann cell-axon communication and axonal metabolic support. Finally, we document perturbed mitochondrial size and distribution along MpzT124M axons suggesting altered axonal transport. Our data suggest that Schwann cells in P0T124M mutant mice cannot provide axons with sufficient trophic support, leading to reduced ATP biosynthesis and axonopathy. In conclusion, the MpzT124M mouse model faithfully reproduces the human neuropathy and represents a unique tool for identifying the molecular basis for glial support of axons.
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23
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Déli É, Peters JF, Kisvárday Z. How the Brain Becomes the Mind: Can Thermodynamics Explain the Emergence and Nature of Emotions? ENTROPY (BASEL, SWITZERLAND) 2022; 24:1498. [PMID: 37420518 DOI: 10.3390/e24101498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/07/2022] [Accepted: 10/11/2022] [Indexed: 07/09/2023]
Abstract
The neural systems' electric activities are fundamental for the phenomenology of consciousness. Sensory perception triggers an information/energy exchange with the environment, but the brain's recurrent activations maintain a resting state with constant parameters. Therefore, perception forms a closed thermodynamic cycle. In physics, the Carnot engine is an ideal thermodynamic cycle that converts heat from a hot reservoir into work, or inversely, requires work to transfer heat from a low- to a high-temperature reservoir (the reversed Carnot cycle). We analyze the high entropy brain by the endothermic reversed Carnot cycle. Its irreversible activations provide temporal directionality for future orientation. A flexible transfer between neural states inspires openness and creativity. In contrast, the low entropy resting state parallels reversible activations, which impose past focus via repetitive thinking, remorse, and regret. The exothermic Carnot cycle degrades mental energy. Therefore, the brain's energy/information balance formulates motivation, sensed as position or negative emotions. Our work provides an analytical perspective of positive and negative emotions and spontaneous behavior from the free energy principle. Furthermore, electrical activities, thoughts, and beliefs lend themselves to a temporal organization, an orthogonal condition to physical systems. Here, we suggest that an experimental validation of the thermodynamic origin of emotions might inspire better treatment options for mental diseases.
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Affiliation(s)
- Éva Déli
- Department of Anatomy, Histology, and Embryology, University of Debrecen, 4032 Debrecen, Hungary
| | - James F Peters
- Department of Electrical & Computer Engineering, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Mathematics, Adiyaman University, Adiyaman 02040, Turkey
| | - Zoltán Kisvárday
- Department of Anatomy, Histology, and Embryology, University of Debrecen, 4032 Debrecen, Hungary
- ELKH Neuroscience Research Group, University of Debrecen, 4032 Debrecen, Hungary
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24
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Düking T, Spieth L, Berghoff SA, Piepkorn L, Schmidke AM, Mitkovski M, Kannaiyan N, Hosang L, Scholz P, Shaib AH, Schneider LV, Hesse D, Ruhwedel T, Sun T, Linhoff L, Trevisiol A, Köhler S, Pastor AM, Misgeld T, Sereda M, Hassouna I, Rossner MJ, Odoardi F, Ischebeck T, de Hoz L, Hirrlinger J, Jahn O, Saher G. Ketogenic diet uncovers differential metabolic plasticity of brain cells. SCIENCE ADVANCES 2022; 8:eabo7639. [PMID: 36112685 PMCID: PMC9481126 DOI: 10.1126/sciadv.abo7639] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
To maintain homeostasis, the body, including the brain, reprograms its metabolism in response to altered nutrition or disease. However, the consequences of these challenges for the energy metabolism of the different brain cell types remain unknown. Here, we generated a proteome atlas of the major central nervous system (CNS) cell types from young and adult mice, after feeding the therapeutically relevant low-carbohydrate, high-fat ketogenic diet (KD) and during neuroinflammation. Under steady-state conditions, CNS cell types prefer distinct modes of energy metabolism. Unexpectedly, the comparison with KD revealed distinct cell type-specific strategies to manage the altered availability of energy metabolites. Astrocytes and neurons but not oligodendrocytes demonstrated metabolic plasticity. Moreover, inflammatory demyelinating disease changed the neuronal metabolic signature in a similar direction as KD. Together, these findings highlight the importance of the metabolic cross-talk between CNS cells and between the periphery and the brain to manage altered nutrition and neurological disease.
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Affiliation(s)
- Tim Düking
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Stefan A. Berghoff
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lars Piepkorn
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Annika M. Schmidke
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Miso Mitkovski
- City Campus Light Microscopy Facility, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Nirmal Kannaiyan
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Leon Hosang
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, Göttingen, Germany
| | - Patricia Scholz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
| | - Ali H. Shaib
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute for Neuro- and Sensory Physiology, Center for Biostructural Imaging of Neurodegeneration, University Medical Center Göttingen, Göttingen, Germany
| | - Lennart V. Schneider
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Dörte Hesse
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Electron Microscopy Core Unit, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lisa Linhoff
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Translational Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Andrea Trevisiol
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Susanne Köhler
- Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Adrian Marti Pastor
- Institute of Neuronal Cell Biology, Technische Universität München, Cluster for Systems Neurology (SyNergy), German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technische Universität München, Cluster for Systems Neurology (SyNergy), German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Michael Sereda
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Translational Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Imam Hassouna
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Moritz J. Rossner
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Francesca Odoardi
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, Göttingen, Germany
| | - Till Ischebeck
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences and Göttingen Center for Molecular Biosciences (GZMB), University of Göttingen, Göttingen, Germany
- Institute of Plant Biology and Biotechnology (IBBP), Green Biotechnology, University of Münster, Münster, Germany
| | - Livia de Hoz
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Neurowissenschafliches Forschungszentrum, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Johannes Hirrlinger
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Carl-Ludwig-Institute for Physiology, Medical Faculty, University of Leipzig, Leipzig, Germany
| | - Olaf Jahn
- Neuroproteomics Group, Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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25
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Henn RE, Noureldein MH, Elzinga SE, Kim B, Savelieff MG, Feldman EL. Glial-neuron crosstalk in health and disease: A focus on metabolism, obesity, and cognitive impairment. Neurobiol Dis 2022; 170:105766. [PMID: 35584728 PMCID: PMC10071699 DOI: 10.1016/j.nbd.2022.105766] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/28/2022] [Accepted: 05/11/2022] [Indexed: 12/12/2022] Open
Abstract
Dementia is a complex set of disorders affecting normal cognitive function. Recently, several clinical studies have shown that diabetes, obesity, and components of the metabolic syndrome (MetS) are associated with cognitive impairment, including dementias such as Alzheimer's disease. Maintaining normal cognitive function is an intricate process involving coordination of neuron function with multiple brain glia. Well-orchestrated bioenergetics is a central requirement of neurons, which need large amounts of energy but lack significant energy storage capacity. Thus, one of the most important glial functions is to provide metabolic support and ensure an adequate energy supply for neurons. Obesity and metabolic disease dysregulate glial function, leading to a failure to respond to neuron energy demands, which results in neuronal damage. In this review, we outline evidence for links between diabetes, obesity, and MetS components to cognitive impairment. Next, we focus on the metabolic crosstalk between the three major glial cell types, oligodendrocytes, astrocytes, and microglia, with neurons under physiological conditions. Finally, we outline how diabetes, obesity, and MetS components can disrupt glial function, and how this disruption might impair glia-neuron metabolic crosstalk and ultimately promote cognitive impairment.
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Affiliation(s)
- Rosemary E Henn
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Mohamed H Noureldein
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Sarah E Elzinga
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Bhumsoo Kim
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
| | - Masha G Savelieff
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America.
| | - Eva L Feldman
- NeuroNetwork for Emerging Therapies, University of Michigan, Ann Arbor, MI, United States of America; Department of Neurology, University of Michigan, Ann Arbor, MI, United States of America.
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26
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Hu M, Santin JM. Transformation to ischaemia tolerance of frog brain function corresponds to dynamic changes in mRNA co-expression across metabolic pathways. Proc Biol Sci 2022; 289:20221131. [PMID: 35892220 PMCID: PMC9326273 DOI: 10.1098/rspb.2022.1131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Neural activity is costly and requires continuous ATP from aerobic metabolism. Brainstem motor function of American bullfrogs normally collapses after minutes of ischaemia, but following hibernation, it becomes ischaemia-tolerant, generating output for up to 2 h without oxygen or glucose delivery. Transforming the brainstem to function during ischaemia involves a switch to anaerobic glycolysis and brain glycogen. We hypothesized that improving neural performance during ischaemia involves a transcriptional program for glycogen and glucose metabolism. Here we measured mRNA copy number of genes along the path from glycogen metabolism to lactate production using real-time quantitative PCR. The expression of individual genes did not reflect enhanced glucose metabolism. However, the number of co-expressed gene pairs increased early into hibernation, and by the end, most genes involved in glycogen metabolism, glucose transport and glycolysis exhibited striking linear co-expression. By contrast, co-expression of genes in the Krebs cycle and electron transport chain decreased throughout hibernation. Our results uncover reorganization of the metabolic transcriptional network associated with a shift to ischaemia tolerance in brain function. We conclude that modifying gene co-expression may be a critical step in synchronizing storage and use of glucose to achieve ischaemia tolerance in active neural circuits.
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Affiliation(s)
- Min Hu
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, USA
| | - Joseph M. Santin
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, USA
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27
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Chaker-Margot M, Werten S, Dunzendorfer-Matt T, Lechner S, Ruepp A, Scheffzek K, Maier T. Structural basis of activation of the tumor suppressor protein neurofibromin. Mol Cell 2022; 82:1288-1296.e5. [PMID: 35353986 DOI: 10.1016/j.molcel.2022.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/14/2022] [Accepted: 03/03/2022] [Indexed: 12/15/2022]
Abstract
Mutations in the NF1 gene cause the familial genetic disease neurofibromatosis type I, as well as predisposition to cancer. The NF1 gene product, neurofibromin, is a GTPase-activating protein and acts as a tumor suppressor by negatively regulating the small GTPase, Ras. However, structural insights into neurofibromin activation remain incompletely defined. Here, we provide cryoelectron microscopy (cryo-EM) structures that reveal an extended neurofibromin homodimer in two functional states: an auto-inhibited state with occluded Ras-binding site and an asymmetric open state with an exposed Ras-binding site. Mechanistically, the transition to the active conformation is stimulated by nucleotide binding, which releases a lock that tethers the catalytic domain to an extended helical repeat scaffold in the occluded state. Structure-guided mutational analysis supports functional relevance of allosteric control. Disease-causing mutations are mapped and primarily impact neurofibromin stability. Our findings suggest a role for nucleotides in neurofibromin regulation and may lead to therapeutic modulation of Ras signaling.
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Affiliation(s)
| | - Sebastiaan Werten
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | | | - Stefan Lechner
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Angela Ruepp
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria
| | - Klaus Scheffzek
- Institute of Biological Chemistry, Biocenter, Medical University of Innsbruck, Innsbruck 6020, Austria.
| | - Timm Maier
- Biozentrum, University of Basel, 4056 Basel, Switzerland.
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28
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Morató L, Astori S, Zalachoras I, Rodrigues J, Ghosal S, Huang W, Guillot de Suduiraut I, Grosse J, Zanoletti O, Cao L, Auwerx J, Sandi C. eNAMPT actions through nucleus accumbens NAD +/SIRT1 link increased adiposity with sociability deficits programmed by peripuberty stress. SCIENCE ADVANCES 2022; 8:eabj9109. [PMID: 35235362 PMCID: PMC8890725 DOI: 10.1126/sciadv.abj9109] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/05/2022] [Indexed: 05/15/2023]
Abstract
Obesity is frequently associated with impairments in the social domain, and stress at puberty can lead to long-lasting changes in visceral fat deposition and in social behaviors. However, whether stress-induced changes in adipose tissue can affect fat-to-brain signaling, thereby orchestrating behavioral changes, remains unknown. We found that peripubertally stressed male-but not female-mice exhibit concomitant increased adiposity and sociability deficits. We show that reduced levels of the adipokine nicotinamide phosphoribosyltransferase (NAMPT) in fat and its extracellular form eNAMPT in blood contribute to lifelong reductions in sociability induced by peripubertal stress. By using a series of adipose tissue and brain region-specific loss- and gain-of-function approaches, we implicate impaired nicotinamide adenine dinucleotide (NAD+)/SIRT1 pathway in the nucleus accumbens. Impairments in sociability and accumbal neuronal excitability are prevented by normalization of eNAMPT levels or treatment with nicotinamide mononucleotide (NMN), a NAD+-boosting compound. We propose NAD+ boosters to treat social deficits of early life stress origin.
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Affiliation(s)
- Laia Morató
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Simone Astori
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Ioannis Zalachoras
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Joao Rodrigues
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Sriparna Ghosal
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Wei Huang
- The Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Isabelle Guillot de Suduiraut
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jocelyn Grosse
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Olivia Zanoletti
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Lei Cao
- The Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Johan Auwerx
- Laboratory of Integrative Systems Physiology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Carmen Sandi
- Laboratory of Behavioral Genetics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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29
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San Martín A, Arce-Molina R, Aburto C, Baeza-Lehnert F, Barros LF, Contreras-Baeza Y, Pinilla A, Ruminot I, Rauseo D, Sandoval PY. Visualizing physiological parameters in cells and tissues using genetically encoded indicators for metabolites. Free Radic Biol Med 2022; 182:34-58. [PMID: 35183660 DOI: 10.1016/j.freeradbiomed.2022.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/07/2023]
Abstract
The study of metabolism is undergoing a renaissance. Since the year 2002, over 50 genetically-encoded fluorescent indicators (GEFIs) have been introduced, capable of monitoring metabolites with high spatial/temporal resolution using fluorescence microscopy. Indicators are fusion proteins that change their fluorescence upon binding a specific metabolite. There are indicators for sugars, monocarboxylates, Krebs cycle intermediates, amino acids, cofactors, and energy nucleotides. They permit monitoring relative levels, concentrations, and fluxes in living systems. At a minimum they report relative levels and, in some cases, absolute concentrations may be obtained by performing ad hoc calibration protocols. Proper data collection, processing, and interpretation are critical to take full advantage of these new tools. This review offers a survey of the metabolic indicators that have been validated in mammalian systems. Minimally invasive, these indicators have been instrumental for the purposes of confirmation, rebuttal and discovery. We envision that this powerful technology will foster metabolic physiology.
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Affiliation(s)
- A San Martín
- Centro de Estudios Científicos (CECs), Valdivia, Chile.
| | - R Arce-Molina
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - C Aburto
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | | | - L F Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - Y Contreras-Baeza
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - A Pinilla
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - I Ruminot
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - D Rauseo
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - P Y Sandoval
- Centro de Estudios Científicos (CECs), Valdivia, Chile
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30
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Mayorga-Weber G, Rivera FJ, Castro MA. Neuron-glia (mis)interactions in brain energy metabolism during aging. J Neurosci Res 2022; 100:835-854. [PMID: 35085408 DOI: 10.1002/jnr.25015] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/08/2021] [Accepted: 12/06/2021] [Indexed: 02/06/2023]
Abstract
Life expectancy in humans is increasing, resulting in a growing aging population, that is accompanied by an increased disposition to develop cognitive deterioration. Hypometabolism is one of the multiple factors related to inefficient brain function during aging. This review emphasizes the metabolic interactions between glial cells (astrocytes, oligodendrocytes, and microglia) and neurons, particularly, during aging. Glial cells provide support and protection to neurons allowing adequate synaptic activity. We address metabolic coupling from the expression of transporters, availability of substrates, metabolic pathways, and mitochondrial activity. In aging, the main metabolic exchange machinery is altered with inefficient levels of nutrients and detrimental mitochondrial activity that results in high reactive oxygen species levels and reduced ATP production, generating a highly inflammatory environment that favors deregulated cell death. Here, we provide an overview of the glial-to-neuron mechanisms, from the molecular components to the cell types, emphasizing aging as the crucial risk factor for developing neurodegenerative/neuroinflammatory diseases.
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Affiliation(s)
- Gonzalo Mayorga-Weber
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Francisco J Rivera
- Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile.,Laboratory of Stem Cells and Neuroregeneration, Instituto de Anatomía, Histología y Patología, Facultad de Medicina, Universidad Austral de Chile, Valdivia, Chile.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Maite A Castro
- Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.,Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile.,Janelia Research Campus, HHMI, Ashburn, VA, USA
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31
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Padamsey Z, Katsanevaki D, Dupuy N, Rochefort NL. Neocortex saves energy by reducing coding precision during food scarcity. Neuron 2022; 110:280-296.e10. [PMID: 34741806 PMCID: PMC8788933 DOI: 10.1016/j.neuron.2021.10.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/07/2021] [Accepted: 10/15/2021] [Indexed: 11/21/2022]
Abstract
Information processing is energetically expensive. In the mammalian brain, it is unclear how information coding and energy use are regulated during food scarcity. Using whole-cell recordings and two-photon imaging in layer 2/3 mouse visual cortex, we found that food restriction reduced AMPA receptor conductance, reducing synaptic ATP use by 29%. Neuronal excitability was nonetheless preserved by a compensatory increase in input resistance and a depolarized resting potential. Consequently, neurons spiked at similar rates as controls but spent less ATP on underlying excitatory currents. This energy-saving strategy had a cost because it amplified the variability of visually-evoked subthreshold responses, leading to a 32% broadening of orientation tuning and impaired fine visual discrimination. This reduction in coding precision was associated with reduced levels of the fat mass-regulated hormone leptin and was restored by exogenous leptin supplementation. Our findings reveal that metabolic state dynamically regulates the energy spent on coding precision in neocortex.
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Affiliation(s)
- Zahid Padamsey
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK.
| | - Danai Katsanevaki
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Nathalie Dupuy
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Nathalie L Rochefort
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK.
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Abstract
Bipolar disorder (BD) is a complex group of neuropsychiatric disorders, typically comprising both manic and depressive episodes. The underlying neuropathology of BD is not established, but a consistent feature is progressive thinning of cortical grey matter (GM) and white matter (WM) in specific pathways, due to loss of subpopulations of neurons and astrocytes, with accompanying disturbance of connectivity. Dysregulation of astrocyte homeostatic functions are implicated in BD, notably regulation of glutamate, calcium signalling, circadian rhythms and metabolism. Furthermore, the beneficial therapeutic effects of the frontline treatments for BD are due at least in part to their positive actions on astrocytes, notably lithium, valproic acid (VPA) and carbamazepine (CBZ), as well as antidepressants and antipsychotics that are used in the management of this disorder. Treatments for BD are ineffective in a large proportion of cases, and astrocytes represent new therapeutic targets that can also serve as biomarkers of illness progression and treatment responsiveness in BD.
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Strachan EL, Mac White-Begg D, Crean J, Reynolds AL, Kennedy BN, O'Sullivan NC. The Role of Mitochondria in Optic Atrophy With Autosomal Inheritance. Front Neurosci 2021; 15:784987. [PMID: 34867178 PMCID: PMC8634724 DOI: 10.3389/fnins.2021.784987] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/22/2021] [Indexed: 11/13/2022] Open
Abstract
Optic atrophy (OA) with autosomal inheritance is a form of optic neuropathy characterized by the progressive and irreversible loss of vision. In some cases, this is accompanied by additional, typically neurological, extra-ocular symptoms. Underlying the loss of vision is the specific degeneration of the retinal ganglion cells (RGCs) which form the optic nerve. Whilst autosomal OA is genetically heterogenous, all currently identified causative genes appear to be associated with mitochondrial organization and function. However, it is unclear why RGCs are particularly vulnerable to mitochondrial aberration. Despite the relatively high prevalence of this disorder, there are currently no approved treatments. Combined with the lack of knowledge concerning the mechanisms through which aberrant mitochondrial function leads to RGC death, there remains a clear need for further research to identify the underlying mechanisms and develop treatments for this condition. This review summarizes the genes known to be causative of autosomal OA and the mitochondrial dysfunction caused by pathogenic mutations. Furthermore, we discuss the suitability of available in vivo models for autosomal OA with regards to both treatment development and furthering the understanding of autosomal OA pathology.
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Affiliation(s)
- Elin L Strachan
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Delphi Mac White-Begg
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - John Crean
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland.,UCD Diabetes Complications Research Centre, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Alison L Reynolds
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Breandán N Kennedy
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD Conway Institute, University College Dublin, Dublin, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
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Chamberlain KA, Huang N, Xie Y, LiCausi F, Li S, Li Y, Sheng ZH. Oligodendrocytes enhance axonal energy metabolism by deacetylation of mitochondrial proteins through transcellular delivery of SIRT2. Neuron 2021; 109:3456-3472.e8. [PMID: 34506725 PMCID: PMC8571020 DOI: 10.1016/j.neuron.2021.08.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 07/21/2021] [Accepted: 08/11/2021] [Indexed: 10/20/2022]
Abstract
Neurons require mechanisms to maintain ATP homeostasis in axons, which are highly vulnerable to bioenergetic failure. Here, we elucidate a transcellular signaling mechanism by which oligodendrocytes support axonal energy metabolism via transcellular delivery of NAD-dependent deacetylase SIRT2. SIRT2 is undetectable in neurons but enriched in oligodendrocytes and released within exosomes. By deleting sirt2, knocking down SIRT2, or blocking exosome release, we demonstrate that transcellular delivery of SIRT2 is critical for axonal energy enhancement. Mass spectrometry and acetylation analyses indicate that neurons treated with oligodendrocyte-conditioned media from WT, but not sirt2-knockout, mice exhibit strong deacetylation of mitochondrial adenine nucleotide translocases 1 and 2 (ANT1/2). In vivo delivery of SIRT2-filled exosomes into myelinated axons rescues mitochondrial integrity in sirt2-knockout mouse spinal cords. Thus, our study reveals an oligodendrocyte-to-axon delivery of SIRT2, which enhances ATP production by deacetylating mitochondrial proteins, providing a target for boosting axonal bioenergetic metabolism in neurological disorders.
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Affiliation(s)
- Kelly A Chamberlain
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA
| | - Ning Huang
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA
| | - Yuxiang Xie
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA
| | - Francesca LiCausi
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA
| | - Sunan Li
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA
| | - Yan Li
- Proteomics Core Facility, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 1B-1014, 35 Convent Drive, Bethesda, MD 20892-3706, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706, USA.
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35
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Abe Y, Kwon S, Oishi M, Unekawa M, Takata N, Seki F, Koyama R, Abe M, Sakimura K, Masamoto K, Tomita Y, Okano H, Mushiake H, Tanaka KF. Optical manipulation of local cerebral blood flow in the deep brain of freely moving mice. Cell Rep 2021; 36:109427. [PMID: 34320360 DOI: 10.1016/j.celrep.2021.109427] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/07/2021] [Accepted: 06/29/2021] [Indexed: 11/18/2022] Open
Abstract
An artificial tool for manipulating local cerebral blood flow (CBF) is necessary for understanding how CBF controls brain function. Here, we generate vascular optogenetic tools whereby smooth muscle cells and endothelial cells express optical actuators in the brain. The illumination of channelrhodopsin-2 (ChR2)-expressing mice induces a local reduction in CBF. Photoactivated adenylyl cyclase (PAC) is an optical protein that increases intracellular cyclic adenosine monophosphate (cAMP), and the illumination of PAC-expressing mice induces a local increase in CBF. We target the ventral striatum, determine the temporal kinetics of CBF change, and optimize the illumination intensity to confine the effects to the ventral striatum. We demonstrate the utility of this vascular optogenetic manipulation in freely and adaptively behaving mice and validate the task- and actuator-dependent behavioral readouts. The development of vascular optogenetic animal models will help accelerate research linking vasculature, circuits, and behavior to health and disease.
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Affiliation(s)
- Yoshifumi Abe
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan; Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan
| | - Soojin Kwon
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan; Department of Physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan
| | - Mitsuhiro Oishi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Miyuki Unekawa
- Department of Neurology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Norio Takata
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan; Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan
| | - Fumiko Seki
- Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan; Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Ryuta Koyama
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kenji Sakimura
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Kazuto Masamoto
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo 182-8585, Japan
| | - Yutaka Tomita
- Department of Neurology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Hideyuki Okano
- Live Imaging Center, Central Institute for Experimental Animals, Kawasaki 210-0821, Japan; Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan; Laboratory for Marmoset Neural Architecture, RIKEN Center for Brain Science, Saitama 351-0198, Japan
| | - Hajime Mushiake
- Department of Physiology, Tohoku University School of Medicine, Sendai 980-8575, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan.
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36
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Aghanoori MR, Margulets V, Smith DR, Kirshenbaum LA, Gitler D, Fernyhough P. Sensory neurons derived from diabetic rats exhibit deficits in functional glycolysis and ATP that are ameliorated by IGF-1. Mol Metab 2021; 49:101191. [PMID: 33592336 PMCID: PMC7940986 DOI: 10.1016/j.molmet.2021.101191] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE The distal dying-back of the longest nerve fibres is a hallmark of diabetic neuropathy, and impaired provision of energy in the form of adenosine triphosphate (ATP) may contribute to this neurodegenerative process. We hypothesised that energy supplementation via glycolysis and/or mitochondrial oxidative phosphorylation is compromised in cultured dorsal root ganglion (DRG) sensory neurons from diabetic rodents, thus contributing to axonal degeneration. Functional analysis of glycolysis and mitochondrial respiration and real-time measurement of ATP levels in live cells were our specific means to test this hypothesis. METHODS DRG neuron cultures from age-matched control or streptozotocin (STZ)-induced type 1 diabetic rats were used for in vitro studies. Three plasmids containing ATP biosensors of varying affinities were transfected into neurons to study endogenous ATP levels in real time. The Seahorse XF analyser was used for glycolysis and mitochondrial respiration measurements. RESULTS Fluorescence resonance energy transfer (FRET) efficiency (YFP/CFP ratio) of the ATP biosensors AT1.03 (low affinity) and AT1.03YEMK (medium affinity) were significantly higher than that measured using the ATP-insensitive construct AT1.03R122/6K in both cell bodies and neurites of DRG neurons (p < 0.0001). The ATP level was homogenous along the axons but higher in cell bodies in cultured DRG neurons from both control and diabetic rats. Treatment with oligomycin (an ATP synthase inhibitor in mitochondria) decreased the ATP levels in cultured DRG neurons. Likewise, blockade of glycolysis using 2-deoxy-d-glucose (2-DG: a glucose analogue) reduced ATP levels (p < 0.001). Cultured DRG neurons derived from diabetic rats showed a diminishment of ATP levels (p < 0.01), glycolytic capacity, glycolytic reserve and non-glycolytic acidification. Application of insulin-like growth factor-1 (IGF-1) significantly elevated all the above parameters in DRG neurons from diabetic rats. Oligomycin pre-treatment of DRG neurons, to block oxidative phosphorylation, depleted the glycolytic reserve and lowered basal respiration in sensory neurons derived from control and diabetic rats. Depletion was much higher in sensory neurons from diabetic rats compared to control rats. In addition, an acute increase in glucose concentration, in the presence or absence of oligomycin, elevated parameters of glycolysis by 1.5- to 2-fold while having no impact on mitochondrial respiration. CONCLUSION We provide the first functional evidence for decreased glycolytic capacity in DRG neurons derived from type 1 diabetic rats. IGF-1 protected against the loss of ATP supplies in DRG cell bodies and axons in neurons derived from diabetic rats by augmenting various parameters of glycolysis and mitochondrial respiration.
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Affiliation(s)
- Mohamad-Reza Aghanoori
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada; Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Vicky Margulets
- Department of Physiology & Pathophysiology, University of Manitoba, Winnipeg, MB, Canada
| | - Darrell R Smith
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
| | - Lorrie A Kirshenbaum
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada; Department of Physiology & Pathophysiology, University of Manitoba, Winnipeg, MB, Canada; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
| | - Daniel Gitler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Paul Fernyhough
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada; Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada.
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Grainger N, Guarina L, Cudmore RH, Santana LF. The Organization of the Sinoatrial Node Microvasculature Varies Regionally to Match Local Myocyte Excitability. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab031. [PMID: 34250490 PMCID: PMC8259512 DOI: 10.1093/function/zqab031] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/28/2021] [Accepted: 06/10/2021] [Indexed: 01/06/2023]
Abstract
The cardiac cycle starts when an action potential is produced by pacemaking cells in the sinoatrial node. This cycle is repeated approximately 100 000 times in humans and 1 million times in mice per day, imposing a monumental metabolic demand on the heart, requiring efficient blood supply via the coronary vasculature to maintain cardiac function. Although the ventricular coronary circulation has been extensively studied, the relationship between vascularization and cellular pacemaking modalities in the sinoatrial node is poorly understood. Here, we tested the hypothesis that the organization of the sinoatrial node microvasculature varies regionally, reflecting local myocyte firing properties. We show that vessel densities are higher in the superior versus inferior sinoatrial node. Accordingly, sinoatrial node myocytes are closer to vessels in the superior versus inferior regions. Superior and inferior sinoatrial node myocytes produce stochastic subthreshold voltage fluctuations and action potentials. However, the intrinsic action potential firing rate of sinoatrial node myocytes is higher in the superior versus inferior node. Our data support a model in which the microvascular densities vary regionally within the sinoatrial node to match the electrical and Ca2+ dynamics of nearby myocytes, effectively determining the dominant pacemaking site within the node. In this model, the high vascular density in the superior sinoatrial node places myocytes with metabolically demanding, high-frequency action potentials near vessels. The lower vascularization and electrical activity of inferior sinoatrial node myocytes could limit these cells to function to support sinoatrial node periodicity with sporadic voltage fluctuations via a stochastic resonance mechanism.
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Ravera S, Bartolucci M, Calzia D, Morelli AM, Panfoli I. Efficient extra-mitochondrial aerobic ATP synthesis in neuronal membrane systems. J Neurosci Res 2021; 99:2250-2260. [PMID: 34085315 DOI: 10.1002/jnr.24865] [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: 05/13/2020] [Revised: 04/29/2021] [Accepted: 05/10/2021] [Indexed: 11/09/2022]
Abstract
The nervous system displays high energy consumption, apparently not fulfilled by mitochondria, which are underrepresented therein. The oxidative phosphorylation (OxPhos) activity, a mitochondrial process that aerobically provides ATP, has also been reported also in the myelin sheath and the rod outer segment (OS) disks. Thus, commonalities and differences between the extra-mitochondrial and mitochondrial aerobic metabolism were evaluated in bovine isolated myelin (IM), rod OS, and mitochondria-enriched fractions (MIT). The subcellular fraction quality and the absence of contamination fractions have been estimated by western blot analysis. Oxygen consumption and ATP synthesis were stimulated by conventional (pyruvate + malate or succinate) and unconventional (NADH) substrates, observing that oxygen consumption and ATP synthesis by IM and rod OS are more efficient than by MIT, in the presence of both kinds of respiratory substrates. Mitochondria did not utilize NADH as a respiring substrate. When ATP synthesis by either sample was assayed in the presence of 10-100 µM ATP in the assay medium, only in IM and OS it was not inhibited, suggesting that the ATP exportation by the mitochondria is limited by extravesicular ATP concentration. Interestingly, IM and OS but not mitochondria appear able to synthesize ATP at a later time with respect to exposure to respiratory substrates, supporting the hypothesis that the proton gradient produced by the electron transport chain is buffered by membrane phospholipids. The putative transfer mode of the OxPhos molecular machinery from mitochondria to the extra-mitochondrial structures is also discussed, opening new perspectives in the field of neurophysiology.
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Affiliation(s)
- Silvia Ravera
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Martina Bartolucci
- Laboratory of Mass Spectrometry - Core Facilities, Istituto Giannina Gaslini, Genoa, Italy.,Department of Pharmacy, Biochemistry Lab., University of Genoa, Genoa, Italy
| | - Daniela Calzia
- Department of Pharmacy, Biochemistry Lab., University of Genoa, Genoa, Italy
| | | | - Isabella Panfoli
- Department of Pharmacy, Biochemistry Lab., University of Genoa, Genoa, Italy
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39
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Jung S, Harris N, Niyonshuti II, Jenkins SV, Hayar AM, Watanabe F, Jamshidi-Parsian A, Chen J, Borrelli MJ, Griffin RJ. Photothermal Response Induced by Nanocage-Coated Artificial Extracellular Matrix Promotes Neural Stem Cell Differentiation. NANOMATERIALS 2021; 11:nano11051216. [PMID: 34064443 PMCID: PMC8147862 DOI: 10.3390/nano11051216] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 12/11/2022]
Abstract
Strategies to increase the proportion of neural stem cells that differentiate into neurons are vital for therapy of neurodegenerative disorders. In vitro, the extracellular matrix composition and topography have been found to be important factors in stem cell differentiation. We have developed a novel artificial extracellular matrix (aECM) formed by attaching gold nanocages (AuNCs) to glass coverslips. After culturing rat neural stem cells (rNSCs) on these gold nanocage-coated surfaces (AuNC-aECMs), we observed that 44.6% of rNSCs differentiated into neurons compared to only 27.9% for cells grown on laminin-coated glass coverslips. We applied laser irradiation to the AuNC-aECMs to introduce precise amounts of photothermally induced heat shock in cells. Our results showed that laser-induced thermal stimulation of AuNC-aECMs further enhanced neuronal differentiation (56%) depending on the laser intensity used. Response to these photothermal effects increased the expression of heat shock protein 27, 70, and 90α in rNSCs. Analysis of dendritic complexity showed that this thermal stimulation promoted neuronal maturation by increasing dendrite length as thermal dose was increased. In addition, we found that cells growing on AuNC-aECMs post laser irradiation exhibited action potentials and increased the expression of voltage-gated Na+ channels compared to laminin-coated glass coverslips. These results indicate that the photothermal response induced in cells growing on AuNC-aECMs can be used to produce large quantities of functional neurons, with improved electrochemical properties, that can potentially be transplanted into a damaged central nervous system to provide replacement neurons and restore lost function.
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Affiliation(s)
- Seunghyun Jung
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (S.J.); (M.J.B.)
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (S.V.J.); (A.J.-P.)
| | - Nathaniel Harris
- Mechanical Engineering, University of Arkansas, Fayetteville, AR 72701, USA;
| | - Isabelle I. Niyonshuti
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA; (I.I.N.); (J.C.)
| | - Samir V. Jenkins
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (S.V.J.); (A.J.-P.)
| | - Abdallah M. Hayar
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA;
| | - Fumiya Watanabe
- Center for Integrative Nanotechnology Sciences, University of Arkansas, Little Rock, AR 72204, USA;
| | - Azemat Jamshidi-Parsian
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (S.V.J.); (A.J.-P.)
| | - Jingyi Chen
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA; (I.I.N.); (J.C.)
| | - Michael J. Borrelli
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (S.J.); (M.J.B.)
- Department of Radiology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Robert J. Griffin
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (S.V.J.); (A.J.-P.)
- Correspondence: ; Tel.: +1-501-526-7873
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Rivera AD, Chacon-De-La-Rocha I, Pieropan F, Papanikolau M, Azim K, Butt AM. Keeping the ageing brain wired: a role for purine signalling in regulating cellular metabolism in oligodendrocyte progenitors. Pflugers Arch 2021; 473:775-783. [PMID: 33712969 PMCID: PMC8076121 DOI: 10.1007/s00424-021-02544-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/04/2021] [Accepted: 02/19/2021] [Indexed: 02/07/2023]
Abstract
White matter (WM) is a highly prominent feature in the human cerebrum and is comprised of bundles of myelinated axons that form the connectome of the brain. Myelin is formed by oligodendrocytes and is essential for rapid neuronal electrical communication that underlies the massive computing power of the human brain. Oligodendrocytes are generated throughout life by oligodendrocyte precursor cells (OPCs), which are identified by expression of the chondroitin sulphate proteoglycan NG2 (Cspg4), and are often termed NG2-glia. Adult NG2+ OPCs are slowly proliferating cells that have the stem cell-like property of self-renewal and differentiation into a pool of 'late OPCs' or 'differentiation committed' OPCs(COPs) identified by specific expression of the G-protein-coupled receptor GPR17, which are capable of differentiation into myelinating oligodendrocytes. In the adult brain, these reservoirs of OPCs and COPs ensure rapid myelination of new neuronal connections formed in response to neuronal signalling, which underpins learning and cognitive function. However, there is an age-related decline in myelination that is associated with a loss of neuronal function and cognitive decline. The underlying causes of myelin loss in ageing are manifold, but a key factor is the decay in OPC 'stemness' and a decline in their replenishment of COPs, which results in the ultimate failure of myelin regeneration. These changes in ageing OPCs are underpinned by dysregulation of neuronal signalling and OPC metabolic function. Here, we highlight the role of purine signalling in regulating OPC self-renewal and the potential importance of GPR17 and the P2X7 receptor subtype in age-related changes in OPC metabolism. Moreover, age is the main factor in the failure of myelination in chronic multiple sclerosis and myelin loss in Alzheimer's disease, hence understanding the importance of purine signalling in OPC regeneration and myelination is critical for developing new strategies for promoting repair in age-dependent neuropathology.
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Affiliation(s)
- Andrea D Rivera
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, UK
- Department of Neuroscience, Institute of Human Anatomy, University of Padua, Padua, Italy
| | | | - Francesca Pieropan
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, UK
| | - Maria Papanikolau
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, UK
| | - Kasum Azim
- Department of Neurology, Neuroregeneration, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Arthur M Butt
- School of Pharmacy and Biomedical Science, University of Portsmouth, Portsmouth, UK.
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41
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Duncan GJ, Simkins TJ, Emery B. Neuron-Oligodendrocyte Interactions in the Structure and Integrity of Axons. Front Cell Dev Biol 2021; 9:653101. [PMID: 33763430 PMCID: PMC7982542 DOI: 10.3389/fcell.2021.653101] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/15/2021] [Indexed: 12/12/2022] Open
Abstract
The myelination of axons by oligodendrocytes is a highly complex cell-to-cell interaction. Oligodendrocytes and axons have a reciprocal signaling relationship in which oligodendrocytes receive cues from axons that direct their myelination, and oligodendrocytes subsequently shape axonal structure and conduction. Oligodendrocytes are necessary for the maturation of excitatory domains on the axon including nodes of Ranvier, help buffer potassium, and support neuronal energy metabolism. Disruption of the oligodendrocyte-axon unit in traumatic injuries, Alzheimer's disease and demyelinating diseases such as multiple sclerosis results in axonal dysfunction and can culminate in neurodegeneration. In this review, we discuss the mechanisms by which demyelination and loss of oligodendrocytes compromise axons. We highlight the intra-axonal cascades initiated by demyelination that can result in irreversible axonal damage. Both the restoration of oligodendrocyte myelination or neuroprotective therapies targeting these intra-axonal cascades are likely to have therapeutic potential in disorders in which oligodendrocyte support of axons is disrupted.
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Affiliation(s)
- Greg J. Duncan
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
| | - Tyrell J. Simkins
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
- Vollum Institute, Oregon Health & Science University, Portland, OR, United States
- Department of Neurology, VA Portland Health Care System, Portland, OR, United States
| | - Ben Emery
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health & Science University, Portland, OR, United States
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42
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Calkins DJ. Adaptive responses to neurodegenerative stress in glaucoma. Prog Retin Eye Res 2021; 84:100953. [PMID: 33640464 DOI: 10.1016/j.preteyeres.2021.100953] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/08/2021] [Accepted: 02/19/2021] [Indexed: 12/12/2022]
Abstract
Glaucoma causes loss of vision through degeneration of the retinal ganglion cell (RGC) projection to the brain. The disease is characterized by sensitivity to intraocular pressure (IOP) conveyed at the optic nerve head, through which RGC axons pass unmyelinated to form the optic nerve. From this point, a pathogenic triumvirate comprising inflammatory, oxidative, and metabolic stress influence both proximal structures in the retina and distal structures in the optic projection. This review focuses on metabolic stress and how the optic projection may compensate through novel adaptive mechanisms to protect excitatory signaling to the brain. In the retina and proximal nerve head, the unmyelinated RGC axon segment is energy-inefficient, which leads to increased demand for adenosine-5'-triphosphate (ATP) at the risk of vulnerability to Ca2+-related metabolic and oxidative pressure. This vulnerability may underlie the bidirectional nature of progression. However, recent evidence highlights that the optic projection in glaucoma is not passive but rather demonstrates adaptive processes that may push back against neurodegeneration. In the retina, even as synaptic and dendritic pruning ensues, early progression involves enhanced excitability of RGCs. Enhancement involves depolarization of the resting membrane potential and increased response to light, independent of RGC morphological type. This response is axogenic, arising from increased levels and translocation of voltage-gated sodium channels (NaV) in the unmyelinated segment. During this same early period, large-scale networks of gap-junction coupled astrocytes redistribute metabolic resources to the optic projection stressed by elevated IOP to slow loss of axon function. This redistribution may reflect more local remodeling, as astrocyte processes respond to focal metabolic duress by boosting glycogen turnover in response to axonal activity in an effort to promote survival of the healthiest axons. Both enhanced excitability and metabolic redistribution are transient, indicating that the same adaptive mechanisms that apparently serve to slow progression ultimately may be too expensive for the system to sustain over longer periods.
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Affiliation(s)
- David J Calkins
- The Vanderbilt Eye Institute, Nashville, TN, USA; Vanderbilt Vision Research Center, Vanderbilt University Medical Center, 1161 21st Ave S, AA7100 Medical Center North Nashville, Tennessee, 37232, USA.
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Bergaglio T, Luchicchi A, Schenk GJ. Engine Failure in Axo-Myelinic Signaling: A Potential Key Player in the Pathogenesis of Multiple Sclerosis. Front Cell Neurosci 2021; 15:610295. [PMID: 33642995 PMCID: PMC7902503 DOI: 10.3389/fncel.2021.610295] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022] Open
Abstract
Multiple Sclerosis (MS) is a complex and chronic disease of the central nervous system (CNS), characterized by both degenerative and inflammatory processes leading to axonal damage, demyelination, and neuronal loss. In the last decade, the traditional outside-in standpoint on MS pathogenesis, which identifies a primary autoimmune inflammatory etiology, has been challenged by a complementary inside-out theory. By focusing on the degenerative processes of MS, the axo-myelinic system may reveal new insights into the disease triggering mechanisms. Oxidative stress (OS) has been widely described as one of the means driving tissue injury in neurodegenerative disorders, including MS. Axonal mitochondria constitute the main energy source for electrically active axons and neurons and are largely vulnerable to oxidative injury. Consequently, axonal mitochondrial dysfunction might impair efficient axo-glial communication, which could, in turn, affect axonal integrity and the maintenance of axonal, neuronal, and synaptic signaling. In this review article, we argue that OS-derived mitochondrial impairment may underline the dysfunctional relationship between axons and their supportive glia cells, specifically oligodendrocytes and that this mechanism is implicated in the development of a primary cytodegeneration and a secondary pro-inflammatory response (inside-out), which in turn, together with a variably primed host's immune system, may lead to the onset of MS and its different subtypes.
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Affiliation(s)
| | | | - Geert J. Schenk
- Department of Anatomy and Neurosciences, Amsterdam Neuroscience, Amsterdam University Medical Center, Amsterdam MS Center, Amsterdam, Netherlands
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44
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Adams S, Zubov T, Bueschke N, Santin JM. Neuromodulation or energy failure? Metabolic limitations silence network output in the hypoxic amphibian brainstem. Am J Physiol Regul Integr Comp Physiol 2021; 320:R105-R116. [PMID: 33175586 PMCID: PMC7948128 DOI: 10.1152/ajpregu.00209.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/10/2020] [Accepted: 11/02/2020] [Indexed: 11/22/2022]
Abstract
Hypoxia tolerance in the vertebrate brain often involves chemical modulators that arrest neuronal activity to conserve energy. However, in intact networks, it can be difficult to determine whether hypoxia triggers modulators to stop activity in a protective manner or whether activity stops because rates of ATP synthesis are insufficient to support network function. Here, we assessed the extent to which neuromodulation or metabolic limitations arrest activity in the respiratory network of bullfrogs-a circuit that survives moderate periods of oxygen deprivation, presumably, by activating an inhibitory noradrenergic pathway. We confirmed that hypoxia and norepinephrine (NE) reduce network output, consistent with the view that hypoxia may cause the release of NE to inhibit activity. However, these responses differed qualitatively; hypoxia, but not NE, elicited a large motor burst and silenced the network. The stereotyped response to hypoxia persisted in the presence of both NE and an adrenergic receptor blocker that eliminates sensitivity to NE, indicating that noradrenergic signaling does not cause the arrest. Pharmacological inhibition of glycolysis and mitochondrial respiration recapitulated all features of hypoxia on network activity, implying that reduced ATP synthesis underlies the effects of hypoxia. Finally, activating modulatory mechanisms that dampen neuronal excitability when ATP levels fall, KATP channels and AMP-dependent protein kinase, did not resemble the hypoxic response. These results suggest that energy failure-rather than inhibitory modulation-silences the respiratory network during hypoxia and emphasize the need to account for metabolic limitations before concluding that modulators arrest activity as an adaptation for energy conservation in the nervous system.
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Affiliation(s)
- Sasha Adams
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Tanya Zubov
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Nikolaus Bueschke
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
| | - Joseph M Santin
- Department of Biology, The University of North Carolina at Greensboro, Greensboro, North Carolina
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45
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Deli E, Peters J, Kisvárday Z. The thermodynamics of cognition: A mathematical treatment. Comput Struct Biotechnol J 2021; 19:784-793. [PMID: 33552449 PMCID: PMC7843413 DOI: 10.1016/j.csbj.2021.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 10/26/2022] Open
Abstract
There is a general expectation that the laws of classical physics must apply to biology, particularly the neural system. The evoked cycle represents the brain's energy/information exchange with the physical environment through stimulus. Therefore, the thermodynamics of emotions might elucidate the neurological origin of intellectual evolution, and explain the psychological and health consequences of positive and negative emotional states based on their energy profiles. We utilized the Carnot cycle and Landauer's principle to analyze the energetic consequences of the brain's resting and evoked states during and after various cognitive states. Namely, positive emotional states can be represented by the reversed Carnot cycle, whereas negative emotional reactions trigger the Carnot cycle. The two conditions have contrasting energetic and entropic aftereffects with consequences for mental energy. The mathematics of the Carnot and reversed Carnot cycles, which can explain recent findings in human psychology, might be constructive in the scientific endeavor in turning psychology into hard science.
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Affiliation(s)
- Eva Deli
- Institute for Consciousness Studies (ICS), Benczur ter 9, Nyiregyhaza 4400, Hungary
| | - James Peters
- Department of Electrical and Computer Engineering, University of Manitoba, 75A Chancellor's Circle, Winnipeg, MB R3T 5V6, Canada
- Department of Mathematics Faculty of Arts and Sciences, Adiyaman University, Adiyaman, Turkey
| | - Zoltán Kisvárday
- MTA-Debreceni Egyetem, Neuroscience Research Group, 4032 Debrecen, Nagyerdei krt.98., Hungary
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Köhler S, Schmidt H, Fülle P, Hirrlinger J, Winkler U. A Dual Nanosensor Approach to Determine the Cytosolic Concentration of ATP in Astrocytes. Front Cell Neurosci 2020; 14:565921. [PMID: 33192312 PMCID: PMC7530325 DOI: 10.3389/fncel.2020.565921] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 08/26/2020] [Indexed: 11/17/2022] Open
Abstract
Adenosine triphosphate (ATP) is the central energy carrier of all cells and knowledge on the dynamics of the concentration of ATP ([ATP]) provides important insights into the energetic state of a cell. Several genetically encoded fluorescent nanosensors for ATP were developed, which allow following the cytosolic [ATP] at high spatial and temporal resolution using fluorescence microscopy. However, to calibrate the fluorescent signal to [ATP] has remained challenging. To estimate basal cytosolic [ATP] ([ATP]0) in astrocytes, we here took advantage of two ATP nanosensors of the ATeam-family (ATeam1.03; ATeam1.03YEMK) with different affinities for ATP. Altering [ATP] by external stimuli resulted in characteristic pairs of signal changes of both nanosensors, which depend on [ATP]0. Using this dual nanosensor strategy and epifluorescence microscopy, [ATP]0 was estimated to be around 1.5 mM in primary cultures of cortical astrocytes from mice. Furthermore, in astrocytes in acutely isolated cortical slices from mice expressing both nanosensors after stereotactic injection of AAV-vectors, 2-photon microscopy revealed [ATP]0 of 0.7 mM to 1.3 mM. Finally, the change in [ATP] induced in the cytosol of cultured cortical astrocytes by application of azide, glutamate, and an increased extracellular concentration of K+ were calculated as −0.50 mM, −0.16 mM, and 0.07 mM, respectively. In summary, the dual nanosensor approach adds another option for determining the concentration of [ATP] to the increasing toolbox of fluorescent nanosensors for metabolites. This approach can also be applied to other metabolites when two sensors with different binding properties are available.
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Affiliation(s)
- Susanne Köhler
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University Leipzig, Leipzig, Germany
| | - Hartmut Schmidt
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University Leipzig, Leipzig, Germany
| | - Paula Fülle
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University Leipzig, Leipzig, Germany.,Wilhelm-Ostwald-Schule, Gymnasium der Stadt Leipzig, Leipzig, Germany
| | - Johannes Hirrlinger
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University Leipzig, Leipzig, Germany.,Department of Neurogenetics, Max-Planck-Institute for Experimental Medicine, Göttingen, Germany
| | - Ulrike Winkler
- Carl-Ludwig-Institute for Physiology, Faculty of Medicine, University Leipzig, Leipzig, Germany
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Structural myelin defects are associated with low axonal ATP levels but rapid recovery from energy deprivation in a mouse model of spastic paraplegia. PLoS Biol 2020; 18:e3000943. [PMID: 33196637 PMCID: PMC7704050 DOI: 10.1371/journal.pbio.3000943] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 11/30/2020] [Accepted: 10/22/2020] [Indexed: 11/19/2022] Open
Abstract
In several neurodegenerative disorders, axonal pathology may originate from impaired oligodendrocyte-to-axon support of energy substrates. We previously established transgenic mice that allow measuring axonal ATP levels in electrically active optic nerves. Here, we utilize this technique to explore axonal ATP dynamics in the Plpnull/y mouse model of spastic paraplegia. Optic nerves from Plpnull/y mice exhibited lower and more variable basal axonal ATP levels and reduced compound action potential (CAP) amplitudes, providing a missing link between axonal pathology and a role of oligodendrocytes in brain energy metabolism. Surprisingly, when Plpnull/y optic nerves are challenged with transient glucose deprivation, both ATP levels and CAP decline slower, but recover faster upon reperfusion of glucose. Structurally, myelin sheaths display an increased frequency of cytosolic channels comprising glucose and monocarboxylate transporters, possibly facilitating accessibility of energy substrates to the axon. These data imply that complex metabolic alterations of the axon–myelin unit contribute to the phenotype of Plpnull/y mice. Imaging of ATP dynamics in the optic nerve axons of mice lacking the major myelin protein PLP (a model of spastic paraplegia) reveals complex alterations in the metabolic interaction between oligodendrocytes and axons, associated with structural deficits of myelin.
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Moore S, Meschkat M, Ruhwedel T, Trevisiol A, Tzvetanova ID, Battefeld A, Kusch K, Kole MHP, Strenzke N, Möbius W, de Hoz L, Nave KA. A role of oligodendrocytes in information processing. Nat Commun 2020; 11:5497. [PMID: 33127910 PMCID: PMC7599337 DOI: 10.1038/s41467-020-19152-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Myelinating oligodendrocytes enable fast propagation of action potentials along the ensheathed axons. In addition, oligodendrocytes play diverse non-canonical roles including axonal metabolic support and activity-dependent myelination. An open question remains whether myelination also contributes to information processing in addition to speeding up conduction velocity. Here, we analyze the role of myelin in auditory information processing using paradigms that are also good predictors of speech understanding in humans. We compare mice with different degrees of dysmyelination using acute multiunit recordings in the auditory cortex, in combination with behavioral readouts. We find complex alterations of neuronal responses that reflect fatigue and temporal acuity deficits. We observe partially discriminable but similar deficits in well myelinated mice in which glial cells cannot fully support axons metabolically. We suggest a model in which myelination contributes to sustained stimulus perception in temporally complex paradigms, with a role of metabolically active oligodendrocytes in cortical information processing.
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Affiliation(s)
- Sharlen Moore
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- International Max Planck Research School for Neurosciences, Göttingen, Germany
- Göttingen Graduate Center for Neurosciences, Biophysics and Molecular Biosciences, Georg-August-Universität Göttingen, Göttingen, Germany
- Department of Psychological and Brain Sciences, Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, USA
| | - Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Andrea Trevisiol
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Canada
| | - Iva D Tzvetanova
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Section of Pharmacology, School of Medicine, European University Cyprus, Nicosia, Cyprus
| | - Arne Battefeld
- Department of Axonal Signaling, Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Institut des Maladies Neurodégénératives, Université de Bordeaux, Bordeaux, France
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Maarten H P Kole
- Department of Axonal Signaling, Netherlands Institute for Neurosciences, Royal Netherlands Academy of Arts and Science, Amsterdam, The Netherlands
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, University of Utrecht, Utrecht, The Netherlands
| | - Nicola Strenzke
- Institute for Auditory Neuroscience, University Medical Center, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Livia de Hoz
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.
- Charité Medical University, Neuroscience Research Center, Berlin, Germany.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
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Ravera S, Morelli AM, Panfoli I. Myelination increases chemical energy support to the axon without modifying the basic physicochemical mechanism of nerve conduction. Neurochem Int 2020; 141:104883. [PMID: 33075435 DOI: 10.1016/j.neuint.2020.104883] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/28/2020] [Accepted: 10/12/2020] [Indexed: 01/31/2023]
Abstract
The existence of different conductive patterns in unmyelinated and myelinated axons is uncertain. It seems that considering exclusively physical electrical phenomena may be an oversimplification. A novel interpretation of the mechanism of nerve conduction in myelinated nerves is proposed, to explain how the basic mechanism of nerve conduction has been adapted to myelinated conditions. The neurilemma would bear the voltage-gated channels and Na+/K+-ATPase in both unmyelinated and myelinated conditions, the only difference being the sheath wrapping it. The dramatic increase in conduction speed of the myelinated axons would essentially depend on an increment in ATP availability within the internode: myelin would be an aerobic ATP supplier to the axoplasm, through connexons. In fact, neurons rely on aerobic metabolism and on trophic support from oligodendrocytes, that do not normally duplicate after infancy in humans. Such comprehensive framework of nerve impulse propagation in axons may shed new light on the pathophysiology of nervous system disease in humans, seemingly strictly dependent on the viability of the pre-existing oligodendrocyte.
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Affiliation(s)
- Silvia Ravera
- Department of Experimental Medicine, University of Genoa, Genoa, I 16132, Italy
| | - Alessandro Maria Morelli
- Laboratory of Biochemistry, Department of Pharmacy-DIFAR, University of Genoa, Genoa, I 16132, Italy.
| | - Isabella Panfoli
- Laboratory of Biochemistry, Department of Pharmacy-DIFAR, University of Genoa, Genoa, I 16132, Italy
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Mozafari S, Baron-Van Evercooren A. Human stem cell-derived oligodendrocytes: From humanized animal models to cell therapy in myelin diseases. Semin Cell Dev Biol 2020; 116:53-61. [PMID: 33082116 DOI: 10.1016/j.semcdb.2020.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/21/2020] [Accepted: 09/22/2020] [Indexed: 12/15/2022]
Abstract
Oligodendrocytes are main targets in demyelinating and dysmyelinating diseases of the central nervous system (CNS), but are also involved in accidental, neurodegenerative and psychiatric disorders. The underlying pathology of these diseases is not fully understood and treatments are still lacking. The recent discovery of the induced pluripotent stem cell (iPSC) technology has open the possibility to address the biology of human oligodendroglial cells both in the dish and in vivo via engraftment in animal models, and paves the way for the development of treatment for myelin disorders. In this review, we make a short overview of the different sources human oligodendroglial cells, and animal models available for pre-clinical cell therapy. We discuss the anatomical and functional benefit of grafted iPSC-progenitors over their brain counterparts, their use in disease modeling and the missing gaps that still prevent to study their biology in the most integrated way, and to translate iPSC-stem cell based therapy to the clinic.
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Affiliation(s)
- Sabah Mozafari
- Institut du Cerveau et de la Moelle Epinière-Groupe Hospitalier Pitié-Salpêtrière, INSERM, U1127, CNRS, UMR 7225, Sorbonne Université UM75, F-75013 Paris, France; CNRS, UMR 7225, Paris, France; Sorbonne Universités, Université Pierre et MarieCurie Paris 06, UM-75, Paris, France
| | - Anne Baron-Van Evercooren
- Institut du Cerveau et de la Moelle Epinière-Groupe Hospitalier Pitié-Salpêtrière, INSERM, U1127, CNRS, UMR 7225, Sorbonne Université UM75, F-75013 Paris, France; CNRS, UMR 7225, Paris, France; Sorbonne Universités, Université Pierre et MarieCurie Paris 06, UM-75, Paris, France.
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