1
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Osso LA, Hughes EG. Dynamics of mature myelin. Nat Neurosci 2024:10.1038/s41593-024-01642-2. [PMID: 38773349 DOI: 10.1038/s41593-024-01642-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 04/05/2024] [Indexed: 05/23/2024]
Abstract
Myelin, which is produced by oligodendrocytes, insulates axons to facilitate rapid and efficient action potential propagation in the central nervous system. Traditionally viewed as a stable structure, myelin is now known to undergo dynamic modulation throughout life. This Review examines these dynamics, focusing on two key aspects: (1) the turnover of myelin, involving not only the renewal of constituents but the continuous wholesale replacement of myelin membranes; and (2) the structural remodeling of pre-existing, mature myelin, a newly discovered form of neural plasticity that can be stimulated by external factors, including neuronal activity, behavioral experience and injury. We explore the mechanisms regulating these dynamics and speculate that myelin remodeling could be driven by an asymmetry in myelin turnover or reactivation of pathways involved in myelin formation. Finally, we outline how myelin remodeling could have profound impacts on neural function, serving as an integral component of behavioral adaptation.
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Affiliation(s)
- Lindsay A Osso
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ethan G Hughes
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, USA.
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2
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Osipenko S, Bashilov A, Vishnevskaya A, Rumiantseva L, Levashova A, Kovalenko A, Tupertsev B, Kireev A, Nikolaev E, Kostyukevich Y. Investigating the Metabolism of Plants Germinated in Heavy Water, D 2O, and H 218O-Enriched Media Using High-Resolution Mass Spectrometry. Int J Mol Sci 2023; 24:15396. [PMID: 37895078 PMCID: PMC10607710 DOI: 10.3390/ijms242015396] [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: 08/08/2023] [Revised: 08/23/2023] [Accepted: 08/30/2023] [Indexed: 10/29/2023] Open
Abstract
Mass spectrometry has been an essential technique for the investigation of the metabolic pathways of living organisms since its appearance at the beginning of the 20th century. Due to its capability to resolve isotopically labeled species, it can be applied together with stable isotope tracers to reveal the transformation of particular biologically relevant molecules. However, low-resolution techniques, which were used for decades, had limited capabilities for untargeted metabolomics, especially when a large number of compounds are labelled simultaneously. Such untargeted studies may provide new information about metabolism and can be performed with high-resolution mass spectrometry. Here, we demonstrate the capabilities of high-resolution mass spectrometry to obtain insights on the metabolism of a model plant, Lepidium sativum, germinated in D2O and H218O-enriched media. In particular, we demonstrated that in vivo labeling with heavy water helps to identify if a compound is being synthesized at a particular stage of germination or if it originates from seed content, and tandem mass spectrometry allows us to highlight the substructures with incorporated isotope labels. Additionally, we found in vivo labeling useful to distinguish between isomeric compounds with identical fragmentation patterns due to the differences in their formation rates that can be compared by the extent of heavy atom incorporation.
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Affiliation(s)
- Sergey Osipenko
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Anton Bashilov
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
- Institute for Translational Medicine and Biotechnology, First Moscow State Medical University, 119991 Moscow, Russia
| | - Anna Vishnevskaya
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Lidiia Rumiantseva
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Anna Levashova
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Anna Kovalenko
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Boris Tupertsev
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Albert Kireev
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Eugene Nikolaev
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
| | - Yury Kostyukevich
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia; (S.O.); (A.B.); (A.V.); (L.R.); (A.L.); (A.K.); (B.T.); (A.K.); (E.N.)
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3
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Cardona Quiñones RA, Salem Hernández SA, Sekimitsu S, Antongiorgi Torres J, Yerstein O, Safar LT. A neuropsychiatric case of delayed post-hypoxic leukoencephalopathy from opioid intoxication resulting in Anton-Babinski syndrome and quadriplegia. Neurocase 2023; 29:160-166. [PMID: 38713498 DOI: 10.1080/13554794.2024.2350103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/22/2024] [Indexed: 05/08/2024]
Abstract
This is the case of a 26-year-old male who developed Anton Babinski syndrome (ABS), quadriplegia, and delayed post-hypoxic leukoencephalopathy (DPHL) after an opioid overdose. He exhibited cortical blindness, visual anosognosia, and confabulation upon awakening. Several days later, he experienced acute psychosis and agitation. T2-FSE MRI revealed extensive supratentorial leukoencephalopathy involving both cerebral hemispheres, extending to the posterior corpus callosum due to cerebral anoxia. This case report will discuss different types of encephalopathy from opioid abuse, ABS, visual anosognosia, and confabulation's pathogenic mechanisms. It underscores the necessity of researching substance-induced neuropsychiatric disorders and their pathogenic mechanisms for effective treatments.
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Affiliation(s)
| | | | | | | | - Oleg Yerstein
- School of Medicine, Tufts University, Boston, USA
- Neurology, Beth Israel Lahey Medical Center, Burlington, USA
| | - Laura T Safar
- Neurology, Beth Israel Lahey Medical Center, Burlington, USA
- Psychiatry and Behavioral Medicine, Harvard Medical School, Boston, USA
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4
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Kostyukevich Y, Stekolshikova E, Levashova A, Kovalenko A, Vishnevskaya A, Bashilov A, Kireev A, Tupertsev B, Rumiantseva L, Khaitovich P, Osipenko S, Nikolaev E. Untargeted Lipidomics after D 2O Administration Reveals the Turnover Rate of Individual Lipids in Various Organs of Living Organisms. Int J Mol Sci 2023; 24:11725. [PMID: 37511483 PMCID: PMC10380497 DOI: 10.3390/ijms241411725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
The administration of low doses of D2O to living organisms was used for decades for the investigation of metabolic pathways and for the measurement of the turnover rate for specific compounds. Usually, the investigation of the deuterium uptake in lipids is performed by measuring the deuteration level of the palmitic acid residue using GC-MS instruments, and to our knowledge, the application of the modern untargeted LC-MS/MS lipidomics approaches was only reported a few times. Here, we investigated the deuterium uptake for >500 lipids for 13 organs and body liquids of mice (brain, lung, heart, liver, kidney, spleen, plasma, urine, etc.) after 4 days of 100% D2O administration. The maximum deuteration level was observed in the liver, plasma, and lung, while in the brain and heart, the deuteration level was lower. Using MS/MS, we demonstrated the incorporation of deuterium in palmitic and stearic fragments in lipids (PC, PE, TAG, PG, etc.) but not in the corresponding free forms. Our results were analyzed based on the metabolic pathways of lipids.
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Affiliation(s)
- Yury Kostyukevich
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Elena Stekolshikova
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Anna Levashova
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
- Scientific Center of Biomedical Technologies of the Federal Medical and Biological Agency, Krasnogorsky District, Village Light Mountains, Bld. 1, 143442 Moscow, Russia
| | - Anna Kovalenko
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Anna Vishnevskaya
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Anton Bashilov
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Albert Kireev
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Boris Tupertsev
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Lidiia Rumiantseva
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Philipp Khaitovich
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Sergey Osipenko
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
| | - Eugene Nikolaev
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, 121205 Moscow, Russia
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5
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Abstract
All mammalian cell membranes contain cholesterol to maintain membrane integrity. The transport of this hydrophobic lipid is mediated by lipoproteins. Cholesterol is especially enriched in the brain, particularly in synaptic and myelin membranes. Aging involves changes in sterol metabolism in peripheral organs and also in the brain. Some of those alterations have the potential to promote or to counteract the development of neurodegenerative diseases during aging. Here, we summarize the current knowledge of general principles of sterol metabolism in humans and mice, the most widely used model organism in biomedical research. We discuss changes in sterol metabolism that occur in the aged brain and highlight recent developments in cell type-specific cholesterol metabolism in the fast-growing research field of aging and age-related diseases, focusing on Alzheimer's disease. We propose that cell type-specific cholesterol handling and the interplay between cell types critically influence age-related disease processes.
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Affiliation(s)
- Gesine Saher
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany;
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6
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Depp C, Sun T, Sasmita AO, Spieth L, Berghoff SA, Nazarenko T, Overhoff K, Steixner-Kumar AA, Subramanian S, Arinrad S, Ruhwedel T, Möbius W, Göbbels S, Saher G, Werner HB, Damkou A, Zampar S, Wirths O, Thalmann M, Simons M, Saito T, Saido T, Krueger-Burg D, Kawaguchi R, Willem M, Haass C, Geschwind D, Ehrenreich H, Stassart R, Nave KA. Myelin dysfunction drives amyloid-β deposition in models of Alzheimer's disease. Nature 2023; 618:349-357. [PMID: 37258678 PMCID: PMC10247380 DOI: 10.1038/s41586-023-06120-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 04/21/2023] [Indexed: 06/02/2023]
Abstract
The incidence of Alzheimer's disease (AD), the leading cause of dementia, increases rapidly with age, but why age constitutes the main risk factor is still poorly understood. Brain ageing affects oligodendrocytes and the structural integrity of myelin sheaths1, the latter of which is associated with secondary neuroinflammation2,3. As oligodendrocytes support axonal energy metabolism and neuronal health4-7, we hypothesized that loss of myelin integrity could be an upstream risk factor for neuronal amyloid-β (Aβ) deposition, the central neuropathological hallmark of AD. Here we identify genetic pathways of myelin dysfunction and demyelinating injuries as potent drivers of amyloid deposition in mouse models of AD. Mechanistically, myelin dysfunction causes the accumulation of the Aβ-producing machinery within axonal swellings and increases the cleavage of cortical amyloid precursor protein. Suprisingly, AD mice with dysfunctional myelin lack plaque-corralling microglia despite an overall increase in their numbers. Bulk and single-cell transcriptomics of AD mouse models with myelin defects show that there is a concomitant induction of highly similar but distinct disease-associated microglia signatures specific to myelin damage and amyloid plaques, respectively. Despite successful induction, amyloid disease-associated microglia (DAM) that usually clear amyloid plaques are apparently distracted to nearby myelin damage. Our data suggest a working model whereby age-dependent structural defects of myelin promote Aβ plaque formation directly and indirectly and are therefore an upstream AD risk factor. Improving oligodendrocyte health and myelin integrity could be a promising target to delay development and slow progression of AD.
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Affiliation(s)
- Constanze Depp
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Andrew Octavian Sasmita
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, Munich, Germany
| | - Stefan A Berghoff
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, Munich, Germany
| | - Taisiia Nazarenko
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Katharina Overhoff
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Agnes A Steixner-Kumar
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Swati Subramanian
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sahab Arinrad
- Clinical Neuroscience, 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
| | - Sandra Göbbels
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Gesine Saher
- 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
| | - Alkmini Damkou
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, Munich, Germany
| | - Silvia Zampar
- Department of Psychiatry and Psychotherapy, University Medical Center, Georg-August University, Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, University Medical Center, Georg-August University, Göttingen, Germany
| | - Maik Thalmann
- Department of German Philology, Georg-August University, Göttingen, Germany
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
- German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Takashi Saito
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Dilja Krueger-Burg
- Department of Psychiatry and Psychotherapy, University Medical Center, Georg-August University, Göttingen, Germany
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Riki Kawaguchi
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael Willem
- German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians University of Munich, Munich, Germany
| | - Christian Haass
- German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians University of Munich, Munich, Germany
| | - Daniel Geschwind
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Hannelore Ehrenreich
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Ruth Stassart
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Paul-Flechsig-Institute of Neuropathology, University Clinic Leipzig, Leipzig, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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7
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Schidlitzki A, Stanojlovic M, Fournier C, Käufer C, Feja M, Gericke B, Garzotti M, Welford RWD, Steiner MA, Angot E, Richter F. Double-Edged Effects of Venglustat on Behavior and Pathology in Mice Overexpressing α-Synuclein. Mov Disord 2023. [PMID: 37050861 DOI: 10.1002/mds.29398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 03/01/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
BACKGROUND Venglustat is a brain-penetrant, small molecule inhibitor of glucosylceramide synthase used in clinical testing for treatment of Parkinson's disease (PD). Despite beneficial effects in certain cellular and rodent models, patients with PD with mutations in GBA, the gene for lysosomal glucocerebrosidase, experienced worsening of their motor function under venglustat treatment (NCT02906020, MOVES-PD, phase 2 trial). OBJECTIVE The objective of this study was to evaluate venglustat in mouse models of PD with overexpression of wild-type α-synuclein. METHODS Mice overexpressing α-synuclein (Thy1-aSyn line 61) or Gba-mutated mice with viral vector-induced overexpression of α-synuclein in the substantia nigra were administered venglustat as food admixture. Motor and cognitive performance, α-synuclein-related pathology, and microgliosis were compared with untreated controls. RESULTS Venglustat worsened motor function in Thy1-aSyn transgenics on the challenging beam and the pole test. Although venglustat did not alter the cognitive deficit in the Y-maze test, it alleviated anxiety-related behavior in the novel object recognition test. Venglustat reduced soluble and membrane-bound α-synuclein in the striatum and phosphorylated α-synuclein in limbic brain regions. Although venglustat reversed the loss of parvalbumin immunoreactivity in the basolateral amygdala, it tended to increase microgliosis and phosphorylated α-synuclein in the substantia nigra. Furthermore, venglustat also partially worsened motor performance and tended to increase neurofilament light chain in the cerebrospinal fluid in the Gba-deficient model with nigral α-synuclein overexpression and neurodegeneration. CONCLUSIONS Venglustat treatment in two mouse models of α-synuclein overexpression showed that glucosylceramide synthase inhibition had differential detrimental or beneficial effects on behavior and neuropathology possibly related to brain region-specific effects. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Alina Schidlitzki
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Milos Stanojlovic
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Céline Fournier
- CNS Pharmacology and Drug Discovery, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
- Roche Pharma Research and Early Development (pRED), F. Hoffman/La Roche Ltd, Basel, Switzerland
| | - Christopher Käufer
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Malte Feja
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Birthe Gericke
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Marco Garzotti
- CNS Pharmacology and Drug Discovery, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
- Matterhorn Biosciences AG, Basel, Switzerland
| | - Richard W D Welford
- CNS Pharmacology and Drug Discovery, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
- Roche Pharma Research and Early Development (pRED), F. Hoffman/La Roche Ltd, Basel, Switzerland
| | | | - Elodie Angot
- CNS Pharmacology and Drug Discovery, Idorsia Pharmaceuticals Ltd., Allschwil, Switzerland
- Roche Pharma Research and Early Development (pRED), F. Hoffman/La Roche Ltd, Basel, Switzerland
| | - Franziska Richter
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience Hannover, Hannover, Germany
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8
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Barnes-Vélez JA, Aksoy Yasar FB, Hu J. Myelin lipid metabolism and its role in myelination and myelin maintenance. Innovation (N Y) 2023; 4:100360. [PMID: 36588745 PMCID: PMC9800635 DOI: 10.1016/j.xinn.2022.100360] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Myelin is a specialized cell membrane indispensable for rapid nerve conduction. The high abundance of membrane lipids is one of myelin's salient features that contribute to its unique role as an insulator that electrically isolates nerve fibers across their myelinated surface. The most abundant lipids in myelin include cholesterol, glycosphingolipids, and plasmalogens, each playing critical roles in myelin development as well as function. This review serves to summarize the role of lipid metabolism in myelination and myelin maintenance, as well as the molecular determinants of myelin lipid homeostasis, with an emphasis on findings from genetic models. In addition, the implications of myelin lipid dysmetabolism in human diseases are highlighted in the context of hereditary leukodystrophies and neuropathies as well as acquired disorders such as Alzheimer's disease.
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Affiliation(s)
- Joseph A. Barnes-Vélez
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR 00936-5067, USA
| | - Fatma Betul Aksoy Yasar
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
| | - Jian Hu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
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9
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Hillen AEJ, Hruzova M, Rothgangl T, Breur M, Bugiani M, van der Knaap MS, Schwank G, Heine VM. In vivo targeting of a variant causing vanishing white matter using CRISPR/Cas9. Mol Ther Methods Clin Dev 2022; 25:17-25. [PMID: 35317047 PMCID: PMC8917273 DOI: 10.1016/j.omtm.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 02/19/2022] [Indexed: 11/17/2022]
Abstract
Vanishing white matter (VWM) is a leukodystrophy caused by recessive variants in subunits of eIF2B. At present, no curative treatment is available and patients often die at young age. Due to its monogenic nature, VWM is a promising candidate for the development of CRISPR/Cas9-mediated gene therapy. Here we tested a dual-AAV approach in VWM mice encoding CRISPR/Cas9 and a DNA donor template to correct a pathogenic variant in Eif2b5. We performed sequencing analysis to assess gene correction rates and examined effects on the VWM phenotype, including motor behavior. Sequence analysis demonstrated that over 90% of CRISPR/Cas9-induced edits at the targeted locus are insertion or deletion (indel) mutations, rather than precise corrections from the DNA donor template by homology-directed repair. Around half of the CRISPR/Cas9-treated animals died prematurely. VWM mice showed no improvement in motor skills, weight, or neurological scores at 7 months of age, and CRISPR/Cas9-treated controls displayed an induced VWM phenotype. In conclusion, CRISPR/Cas9-induced DNA double-strand breaks (DSBs) at the Eif2b5 locus did not lead to sufficient correction of the VWM variant. Moreover, indel formation in Eif2b5 induced an exacerbated VWM phenotype. Therefore, DSB-independent strategies like base- or prime editing might better suited for VWM correction.
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Affiliation(s)
- Anne E J Hillen
- Department of Pediatrics and Child Neurology, Emma Children's Hospital, Amsterdam Neuroscience, Amsterdam UMC, De Boelelaan 1117, 1081 Amsterdam, the Netherlands
| | - Martina Hruzova
- Department of Biology, Institute for Molecular Health Sciences, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland.,Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Tanja Rothgangl
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Marjolein Breur
- Department of Pediatrics and Child Neurology, Emma Children's Hospital, Amsterdam Neuroscience, Amsterdam UMC, De Boelelaan 1117, 1081 Amsterdam, the Netherlands
| | - Marianna Bugiani
- Department of Pediatrics and Child Neurology, Emma Children's Hospital, Amsterdam Neuroscience, Amsterdam UMC, De Boelelaan 1117, 1081 Amsterdam, the Netherlands
| | - Marjo S van der Knaap
- Department of Pediatrics and Child Neurology, Emma Children's Hospital, Amsterdam Neuroscience, Amsterdam UMC, De Boelelaan 1117, 1081 Amsterdam, the Netherlands.,Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, De Boelelaan 1085, 1081 Amsterdam, the Netherlands
| | - Gerald Schwank
- Department of Biology, Institute for Molecular Health Sciences, ETH Zurich, Otto-Stern-Weg 7, 8093 Zurich, Switzerland.,Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Vivi M Heine
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University, De Boelelaan 1085, 1081 Amsterdam, the Netherlands.,Department of Child and Adolescence Psychiatry, Emma Children's Hospital, Amsterdam Neuroscience, Amsterdam UMC, De Boelelaan 1085, 1081 Amsterdam, the Netherlands
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10
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Narine M, Colognato H. Current Insights Into Oligodendrocyte Metabolism and Its Power to Sculpt the Myelin Landscape. Front Cell Neurosci 2022; 16:892968. [PMID: 35573837 PMCID: PMC9097137 DOI: 10.3389/fncel.2022.892968] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/06/2022] [Indexed: 12/20/2022] Open
Abstract
Once believed to be part of the nervenkitt or “nerve glue” network in the central nervous system (CNS), oligodendroglial cells now have established roles in key neurological functions such as myelination, neuroprotection, and motor learning. More recently, oligodendroglia has become the subject of intense investigations aimed at understanding the contributions of its energetics to CNS physiology and pathology. In this review, we discuss the current understanding of oligodendroglial metabolism in regulating key stages of oligodendroglial development and health, its role in providing energy to neighboring cells such as neurons, as well as how alterations in oligodendroglial bioenergetics contribute to disease states. Importantly, we highlight how certain inputs can regulate oligodendroglial metabolism, including extrinsic and intrinsic mediators of cellular signaling, pharmacological compounds, and even dietary interventions. Lastly, we discuss emerging studies aimed at discovering the therapeutic potential of targeting components within oligodendroglial bioenergetic pathways.
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Affiliation(s)
- Mohanlall Narine
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, United States
- Department of Neurobiology, & Behavior, Stony Brook University, Stony Brook, NY, United States
| | - Holly Colognato
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, United States
- *Correspondence: Holly Colognato
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11
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Furber KL, Lacombe RJS, Caine S, Thangaraj MP, Read S, Rosendahl SM, Bazinet RP, Popescu BF, Nazarali AJ. Biochemical Alterations in White Matter Tracts of the Aging Mouse Brain Revealed by FTIR Spectroscopy Imaging. Neurochem Res 2022; 47:795-810. [PMID: 34820737 DOI: 10.1007/s11064-021-03491-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 05/31/2021] [Accepted: 11/17/2021] [Indexed: 11/25/2022]
Abstract
White matter degeneration in the central nervous system (CNS) has been correlated with a decline in cognitive function during aging. Ultrastructural examination of the aging human brain shows a loss of myelin, yet little is known about molecular and biochemical changes that lead to myelin degeneration. In this study, we investigate myelination across the lifespan in C57BL/6 mice using electron microscopy and Fourier transform infrared (FTIR) spectroscopic imaging to better understand the relationship between structural and biochemical changes in CNS white matter tracts. A decrease in the number of myelinated axons was associated with altered lipid profiles in the corpus callosum of aged mice. FTIR spectroscopic imaging revealed alterations in functional groups associated with phospholipids, including the lipid acyl, lipid ester and phosphate vibrations. Biochemical changes in white matter were observed prior to structural changes and most predominant in the anterior regions of the corpus callosum. This was supported by biochemical analysis of fatty acid composition that demonstrated an overall trend towards increased monounsaturated fatty acids and decreased polyunsaturated fatty acids with age. To further explore the molecular mechanisms underlying these biochemical alterations, gene expression profiles of lipid metabolism and oxidative stress pathways were investigated. A decrease in the expression of several genes involved in glutathione metabolism suggests that oxidative damage to lipids may contribute to age-related white matter degeneration.
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Affiliation(s)
- Kendra L Furber
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
- Division of Medical Sciences, University of Northern British Columbia, Prince George, BC, Canada.
| | - R J Scott Lacombe
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Sally Caine
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Merlin P Thangaraj
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Stuart Read
- Canadian Light Source, Saskatoon, SK, Canada
| | | | - Richard P Bazinet
- Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Bogdan F Popescu
- Department of Anatomy, Physiology and Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Adil J Nazarali
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
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12
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Pappaianni E, Borsarini B, Doucet GE, Hochman A, Frangou S, Micali N. Initial evidence of abnormal brain plasticity in anorexia nervosa: an ultra-high field study. Sci Rep 2022; 12:2589. [PMID: 35173174 PMCID: PMC8850617 DOI: 10.1038/s41598-022-06113-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/05/2022] [Indexed: 11/09/2022] Open
Abstract
Anorexia Nervosa has been associated with white matter abnormalities implicating subcortical abnormal myelination. Extending these findings to intracortical myelin has been challenging but ultra-high field neuroimaging offers new methodological opportunities. To test the integrity of intracortical myelin in AN we used 7 T neuroimaging to acquire T1-weighted images optimized for intracortical myelin from seven females with AN (age range: 18-33) and 11 healthy females (age range: 23-32). Intracortical T1 values (inverse index of myelin concentration) were extracted from 148 cortical regions at ten depth-levels across the cortical ribbon. Across all cortical regions, these levels were averaged to generate estimates of total intracortical myelin concentration and were clustered using principal component analyses into two clusters; the outer cluster comprised T1 values across depth-levels ranging from the CSF boundary to the middle of the cortical regions and the inner cluster comprised T1 values across depth-levels ranging from the middle of the cortical regions to the gray/white matter boundary. Individuals with AN exhibited higher T1 values (i.e., decreased intracortical myelin concentration) in all three metrics. It remains to be established if these abnormalities result from undernutrition or specific lipid nutritional imbalances, or are trait markers; and whether they may contribute to neurobiological deficits seen in AN.
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Affiliation(s)
- Edoardo Pappaianni
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 2 Rue Verte, 1205, Geneva, Switzerland
| | - Bianca Borsarini
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 2 Rue Verte, 1205, Geneva, Switzerland
| | | | - Ayelet Hochman
- Department of Psychology, St. John's University, Queens, NY, USA
| | - Sophia Frangou
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Nadia Micali
- Department of Psychiatry, Faculty of Medicine, University of Geneva, 2 Rue Verte, 1205, Geneva, Switzerland. .,Great Ormond Street Institute of Child Health, University College London, London, UK. .,Department of Pediatrics, Gynecology and Obstetrics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
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13
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Berghoff SA, Spieth L, Saher G. Local cholesterol metabolism orchestrates remyelination. Trends Neurosci 2022; 45:272-283. [DOI: 10.1016/j.tins.2022.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 01/07/2022] [Accepted: 01/21/2022] [Indexed: 12/19/2022]
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14
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Baumann A, Denninger AR, Domin M, Demé B, Kirschner DA. Metabolically-incorporated deuterium in myelin localized by neutron diffraction and identified by mass spectrometry. Curr Res Struct Biol 2022; 4:231-245. [PMID: 35941866 PMCID: PMC9356250 DOI: 10.1016/j.crstbi.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/25/2022] Open
Abstract
Myelin is a natural and dynamic multilamellar membrane structure that continues to be of significant biological and neurological interest, especially with respect to its biosynthesis and assembly during its normal formation, maintenance, and pathological breakdown. To explore the usefulness of neutron diffraction in the structural analysis of myelin, we investigated the use of in vivo labeling by metabolically incorporating non-toxic levels of deuterium (2H; D) via drinking water into a pregnant dam (D-dam) and her developing embryos. All of the mice were sacrificed when the pups (D-pups) were 55 days old. Myelinated sciatic nerves were dissected, fixed in glutaraldehyde and examined by neutron diffraction. Parallel samples that were unfixed (trigeminal nerves) were frozen for mass spectrometry (MS). The diffraction patterns of the nerves from deuterium-fed mice (D-mice) vs. the controls (H-mice) had major differences in the intensities of the Bragg peaks but no appreciable differences in myelin periodicity. Neutron scattering density profiles showed an appreciable increase in density at the center of the lipid-rich membrane bilayer. This increase was greater in D-pups than in D-dam, and its localization was consistent with deuteration of lipid hydrocarbon, which predominates over transmembrane protein in myelin. MS analysis of the lipids isolated from the trigeminal nerves demonstrated that in the pups the percentage of lipids that had one or more deuterium atoms was uniformly high across lipid species (97.6% ± 2.0%), whereas in the mother the lipids were substantially less deuterated (60.6% ± 26.4%) with levels varying among lipid species and subspecies. The mass distribution pattern of deuterium-containing isotopologues indicated the fraction (in %) of each lipid (sub-)species having one or more deuteriums incorporated: in the D-pups, the pattern was always bell-shaped, and the average number of D atoms ranged from a low of ∼4 in fatty acid to a high of ∼9 in cerebroside. By contrast, in D-dam most lipids had more complex, overlapping distributions that were weighted toward a lower average number of deuteriums, which ranged from a low of ∼3–4 in fatty acid and in one species of sulfatide to a high of 6–7 in cerebroside and sphingomyelin. The consistently high level of deuteration in D-pups can be attributed to their de novo lipogenesis during gestation and rapid, postnatal myelination. The widely varying levels of deuteration in D-dam, by contrast, likely depends on the relative metabolic stability of the particular lipid species during myelin maintenance. Our current findings demonstrate that stably-incorporated D label can be detected and localized using neutron diffraction in a complex tissue such as myelin; and moreover, that MS can be used to screen a broad range of deuterated lipid species to monitor differential rates of lipid turnover. In addition to helping to develop a comprehensive understanding of the de novo synthesis and turnover of specific lipids in normal and abnormal myelin, our results also suggest application to studies on myelin proteins (which constitute only 20–30% by dry mass of the myelin, vs. 70–80% for lipid), as well as more broadly to the molecular constituents of other biological tissues. Deuterium metabolically assimilated into gestating mouse pups via drinking water. Neutron diffraction localized deuterium to middle of myelin membrane bilayers. Mass spectrometry identified 26 deuterated lipid species as myelinic. Myelin of pups substantially more deuterated than that of their dam. Deuterium differentially distributed among lipid species and subspecies. De novo lipid biogenesis vs. steady-state maintenance readily distinguished. Novel paradigm suggests application to animal models of human myelinopathies.
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15
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Sanchez-Molina P, Almolda B, Benseny-Cases N, González B, Perálvarez-Marín A, Castellano B. Specific microglial phagocytic phenotype and decrease of lipid oxidation in white matter areas during aging: Implications of different microenvironments. Neurobiol Aging 2021; 105:280-295. [PMID: 34139605 DOI: 10.1016/j.neurobiolaging.2021.03.015] [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: 10/11/2020] [Revised: 03/25/2021] [Accepted: 03/28/2021] [Indexed: 12/25/2022]
Abstract
Physiological aging is characterized by an imbalance of pro-inflammatory and anti-inflammatory mediators leading to neuroinflammation. Microglial cells, which are highly regulated by the local microenvironment, undergo specific changes depending upon the brain area during aging. The aim of this study was to evaluate the influence of age over microglial cells along different brain areas and microenvironments. For this purpose, transgenic mice with overproduction of either the anti-inflammatory IL-10 cytokine or the pro-inflammatory IL-6 cytokine were used. Our results show that, during aging, microglial cells located in white matter (WM) areas maintain their phagocytic capacity but present a specific phagocytic phenotype with receptors involved in myelin recognition, arguing for aging-derived myelin damage. Whereas IL-10 overproduction anticipates the age-related microglial phagocytic phenotype, maintaining it over time, IL-6 overproduction exacerbates this phenotype in aging. These modifications were linked with a higher efficiency of myelin engulfment by microglia in aged transgenic animals. Moreover, we show, in a novel way, lower lipid oxidation during aging in WM areas, regardless of the genotype. The novelty of the insights presented in this study open a window to deeply investigate myelin lipid oxidation and the role of microglial cells in its regulation during physiological aging.
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Affiliation(s)
- Paula Sanchez-Molina
- Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Beatriz Almolda
- Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain.
| | - Núria Benseny-Cases
- ALBA Synchrotron Light Source, Carrer de la Llum 2-26, Cerdanyola del Vallès, Catalonia, Spain
| | - Berta González
- Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Alex Perálvarez-Marín
- Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; Department of Biochemistry and Molecular Biology. Universitat Autònoma de Barcelona, Bellaterra, Catalonia, Spain
| | - Bernardo Castellano
- Institute of Neurosciences, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
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16
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Zhou X, Shin S, He C, Zhang Q, Rasband MN, Ren J, Dai C, Zorrilla-Veloz RI, Shingu T, Yuan L, Wang Y, Chen Y, Lan F, Hu J. Qki regulates myelinogenesis through Srebp2-dependent cholesterol biosynthesis. eLife 2021; 10:60467. [PMID: 33942715 PMCID: PMC8139834 DOI: 10.7554/elife.60467] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 05/01/2021] [Indexed: 01/14/2023] Open
Abstract
Myelination depends on timely, precise control of oligodendrocyte differentiation and myelinogenesis. Cholesterol is the most abundant component of myelin and essential for myelin membrane assembly in the central nervous system. However, the underlying mechanisms of precise control of cholesterol biosynthesis in oligodendrocytes remain elusive. In the present study, we found that Qki depletion in neural stem cells or oligodendrocyte precursor cells in neonatal mice resulted in impaired cholesterol biosynthesis and defective myelinogenesis without compromising their differentiation into Aspa+Gstpi+ myelinating oligodendrocytes. Mechanistically, Qki-5 functions as a co-activator of Srebp2 to control transcription of the genes involved in cholesterol biosynthesis in oligodendrocytes. Consequently, Qki depletion led to substantially reduced concentration of cholesterol in mouse brain, impairing proper myelin assembly. Our study demonstrated that Qki-Srebp2-controlled cholesterol biosynthesis is indispensable for myelinogenesis and highlights a novel function of Qki as a transcriptional co-activator beyond its canonical function as an RNA-binding protein.
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Affiliation(s)
- Xin Zhou
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States.,Cancer Research Institute of Jilin University, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Seula Shin
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States.,Cancer Biology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
| | - Chenxi He
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, and Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qiang Zhang
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, United States
| | - Jiangong Ren
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Congxin Dai
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States.,Department of Neurosurgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Rocío I Zorrilla-Veloz
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States.,Cancer Biology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
| | - Takashi Shingu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Liang Yuan
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States.,Graduate School of Biomedical Sciences, Tufts University, Boston, United States
| | - Yunfei Wang
- Clinical Science Division, H. Lee Moffitt Cancer Center & Research Institute, Tampa, United States
| | - Yiwen Chen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Fei Lan
- Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology, Institutes of Biomedical Sciences, Fudan University, and Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jian Hu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, United States.,Cancer Biology Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States.,Neuroscience Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, United States
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17
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Grieb P, Świątkiewicz M, Kamińska A, Jünemann A, Rejdak R, Rejdak K. Citicoline: A Candidate for Adjunct Treatment of Multiple Sclerosis. Pharmaceuticals (Basel) 2021; 14:ph14040326. [PMID: 33918331 PMCID: PMC8066453 DOI: 10.3390/ph14040326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 12/13/2022] Open
Abstract
In remitting–relapsing multiple sclerosis (RR-MS), relapses are driven by autoreactive immune cells that enter the brain and spinal cord and damage myelin sheaths of axons in white and grey matter, whereas during remissions myelin is repaired by activated oligodendroglial cells. Disease-modifying therapies (DMTs) may either retard/attenuate myelin damage or promote/enhance/speed up myelin repair. Almost all currently approved DMTs inhibit myelin damage and are considerably toxic. Enhancement of myelin repair is considered an unmet medical need of MS patients. Citicoline, known for many years as a nootropic and neuroprotective drug and recently pronounced food supplement, has been found to be significantly efficacious in two complementary rodent models of MS, experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced myelin toxicity. Moreover, citicoline treatment improves visual evoked potentials (VEPs) in glaucoma patients, which is relevant because VEP monitoring is frequently used as an indicator of remyelination in MS. Although over-the-counter availability of citicoline may impede its formal translation to the clinic of MS, evaluation of its efficacy for supporting remyelination in this disease is strongly indicated.
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Affiliation(s)
- Paweł Grieb
- Department of Experimental Pharmacology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 02-106 Warsaw, Poland;
| | - Maciej Świątkiewicz
- Department of Experimental Pharmacology, Mossakowski Medical Research Institute, Polish Academy of Sciences, 02-106 Warsaw, Poland;
- Correspondence:
| | - Agnieszka Kamińska
- Faculty of Medical Sciences, Collegium Medicum, Cardinal Stefan Wyszynski University, 01-938 Warsaw, Poland;
| | - Anselm Jünemann
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-079 Lublin, Poland; (A.J.); (R.R.)
| | - Robert Rejdak
- Chair and Department of General and Pediatric Ophthalmology, Medical University of Lublin, 20-079 Lublin, Poland; (A.J.); (R.R.)
| | - Konrad Rejdak
- Department of Neurology, Medical University of Lublin, 20-954 Lublin, Poland;
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18
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Tepavčević V. Oligodendroglial Energy Metabolism and (re)Myelination. Life (Basel) 2021; 11:238. [PMID: 33805670 PMCID: PMC7998845 DOI: 10.3390/life11030238] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/04/2021] [Accepted: 03/09/2021] [Indexed: 12/12/2022] Open
Abstract
Central nervous system (CNS) myelin has a crucial role in accelerating the propagation of action potentials and providing trophic support to the axons. Defective myelination and lack of myelin regeneration following demyelination can both lead to axonal pathology and neurodegeneration. Energy deficit has been evoked as an important contributor to various CNS disorders, including multiple sclerosis (MS). Thus, dysregulation of energy homeostasis in oligodendroglia may be an important contributor to myelin dysfunction and lack of repair observed in the disease. This article will focus on energy metabolism pathways in oligodendroglial cells and highlight differences dependent on the maturation stage of the cell. In addition, it will emphasize that the use of alternative energy sources by oligodendroglia may be required to save glucose for functions that cannot be fulfilled by other metabolites, thus ensuring sufficient energy input for both myelin synthesis and trophic support to the axons. Finally, it will point out that neuropathological findings in a subtype of MS lesions likely reflect defective oligodendroglial energy homeostasis in the disease.
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Affiliation(s)
- Vanja Tepavčević
- Achucarro Basque Center for Neuroscience, University of the Basque Country, Parque Cientifico de la UPV/EHU, Barrio Sarriena s/n, Edificio Sede, Planta 3, 48940 Leioa, Spain
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19
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Zhou X, He C, Ren J, Dai C, Stevens SR, Wang Q, Zamler D, Shingu T, Yuan L, Chandregowda CR, Wang Y, Ravikumar V, Rao AU, Zhou F, Zheng H, Rasband MN, Chen Y, Lan F, Heimberger AB, Segal BM, Hu J. Mature myelin maintenance requires Qki to coactivate PPARβ-RXRα-mediated lipid metabolism. J Clin Invest 2021; 130:2220-2236. [PMID: 32202512 DOI: 10.1172/jci131800] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 01/17/2020] [Indexed: 12/25/2022] Open
Abstract
Lipid-rich myelin forms electrically insulating, axon-wrapping multilayers that are essential for neural function, and mature myelin is traditionally considered metabolically inert. Surprisingly, we discovered that mature myelin lipids undergo rapid turnover, and quaking (Qki) is a major regulator of myelin lipid homeostasis. Oligodendrocyte-specific Qki depletion, without affecting oligodendrocyte survival, resulted in rapid demyelination, within 1 week, and gradually neurological deficits in adult mice. Myelin lipids, especially the monounsaturated fatty acids and very-long-chain fatty acids, were dramatically reduced by Qki depletion, whereas the major myelin proteins remained intact, and the demyelinating phenotypes of Qki-depleted mice were alleviated by a high-fat diet. Mechanistically, Qki serves as a coactivator of the PPARβ-RXRα complex, which controls the transcription of lipid-metabolism genes, particularly those involved in fatty acid desaturation and elongation. Treatment of Qki-depleted mice with PPARβ/RXR agonists significantly alleviated neurological disability and extended survival durations. Furthermore, a subset of lesions from patients with primary progressive multiple sclerosis were characterized by preferential reductions in myelin lipid contents, activities of various lipid metabolism pathways, and expression level of QKI-5 in human oligodendrocytes. Together, our results demonstrate that continuous lipid synthesis is indispensable for mature myelin maintenance and highlight an underappreciated role of lipid metabolism in demyelinating diseases.
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Affiliation(s)
- Xin Zhou
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Chenxi He
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, and Key Laboratory of Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jiangong Ren
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Congxin Dai
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Department of Neurosurgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Sharon R Stevens
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - Qianghu Wang
- Department of Bioinformatics, and Collaborative Innovation Center for Cancer Personalized Medicine, Nanjing Medical University, Nanjing, China
| | - Daniel Zamler
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
| | - Takashi Shingu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Liang Yuan
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
| | - Chythra R Chandregowda
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Yunfei Wang
- Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Visweswaran Ravikumar
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA
| | - Arvind Uk Rao
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA.,Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Feng Zhou
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, and Institutes of Biomedical Sciences, Shanghai, China
| | - Hongwu Zheng
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, USA
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
| | - Yiwen Chen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Fei Lan
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, and Key Laboratory of Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Amy B Heimberger
- Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Benjamin M Segal
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,The Neurological Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Jian Hu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, Texas, USA
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20
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Diet, Exercise, Lifestyle, and Mental Distress among Young and Mature Men and Women: A Repeated Cross-Sectional Study. Nutrients 2020; 13:nu13010024. [PMID: 33374693 PMCID: PMC7822407 DOI: 10.3390/nu13010024] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/21/2020] [Accepted: 12/21/2020] [Indexed: 12/28/2022] Open
Abstract
Customization of mental health therapies needs to consider the differences in degree of brain maturity between young (18–29 years) and mature (30 years or older) adults as well as brain morphology among men and women. The aim of this study was to identify the significant dietary and lifestyle contributors to mental distress in these sub-populations. Independent repeated cross-sectional sampling was performed for over a 5-year period (2014–2019) to collect data from different populations at different time-points and seasons. A backward stepwise regression analysis was used on 2628 records. Mental distress in young women was associated with high consumption of caffeine and fast-food, and it was negatively correlated with moderate-high levels of exercise as well as frequent breakfast consumption. Mature women shared several common factors with young women; however, high fruit consumption was negatively associated with mental distress. For young men, high exercise, moderate consumption of dairy, and moderate-high intake of meat were negatively associated with mental distress. In addition, high fast-food and caffeine consumption were positively associated with mental distress in young men. For mature men, strong negative associations between higher education, moderate intake of nuts and mental distress surfaced. Our results support the need to customize dietary and lifestyle recommendations to improve mental wellbeing.
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21
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Moise N, Friedman A. A mathematical model of the multiple sclerosis plaque. J Theor Biol 2020; 512:110532. [PMID: 33152395 DOI: 10.1016/j.jtbi.2020.110532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/15/2022]
Abstract
Multiple sclerosis is an autoimmune disease that affects white matter in the central nervous system. It is one of the primary causes of neurological disability among young people. Its characteristic pathological lesion is called a plaque, a zone of inflammatory activity and tissue destruction that expands radially outward by destroying the myelin and oligodendrocytes of white matter. The present paper develops a mathematical model of the multiple sclerosis plaques. Although these plaques do not provide reliable information of the clinical disability in MS, they are nevertheless useful as a primary outcome measure of Phase II trials. The model consists of a system of partial differential equations in a simplified geometry of the lesion, consisting of three domains: perivascular space, demyelinated plaque, and white matter. The model describes the activity of various pro- and anti-inflammatory cells and cytokines in the plaque, and quantifies their effect on plaque growth. We show that volume growth of plaques are in qualitative agreement with reported clinical studies of several currently used drugs. We then use the model to explore treatments with combinations of such drugs, and with experimental drugs. We finally consider the benefits of early vs. delayed treatment.
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Affiliation(s)
- Nicolae Moise
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania; Department of Biomedical Engineering, Ohio State University, Columbus, OH, USA
| | - Avner Friedman
- Mathematical Biosciences Institute & Department of Mathematics, Ohio State University, Columbus, OH, USA.
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22
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Chew H, Solomon VA, Fonteh AN. Involvement of Lipids in Alzheimer's Disease Pathology and Potential Therapies. Front Physiol 2020; 11:598. [PMID: 32581851 PMCID: PMC7296164 DOI: 10.3389/fphys.2020.00598] [Citation(s) in RCA: 154] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022] Open
Abstract
Lipids constitute the bulk of the dry mass of the brain and have been associated with healthy function as well as the most common pathological conditions of the brain. Demographic factors, genetics, and lifestyles are the major factors that influence lipid metabolism and are also the key components of lipid disruption in Alzheimer's disease (AD). Additionally, the most common genetic risk factor of AD, APOE ϵ4 genotype, is involved in lipid transport and metabolism. We propose that lipids are at the center of Alzheimer's disease pathology based on their involvement in the blood-brain barrier function, amyloid precursor protein (APP) processing, myelination, membrane remodeling, receptor signaling, inflammation, oxidation, and energy balance. Under healthy conditions, lipid homeostasis bestows a balanced cellular environment that enables the proper functioning of brain cells. However, under pathological conditions, dyshomeostasis of brain lipid composition can result in disturbed BBB, abnormal processing of APP, dysfunction in endocytosis/exocytosis/autophagocytosis, altered myelination, disturbed signaling, unbalanced energy metabolism, and enhanced inflammation. These lipid disturbances may contribute to abnormalities in brain function that are the hallmark of AD. The wide variance of lipid disturbances associated with brain function suggest that AD pathology may present as a complex interaction between several metabolic pathways that are augmented by risk factors such as age, genetics, and lifestyles. Herewith, we examine factors that influence brain lipid composition, review the association of lipids with all known facets of AD pathology, and offer pointers for potential therapies that target lipid pathways.
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Affiliation(s)
- Hannah Chew
- Huntington Medical Research Institutes, Pasadena, CA, United States
- University of California, Los Angeles, Los Angeles, CA, United States
| | | | - Alfred N. Fonteh
- Huntington Medical Research Institutes, Pasadena, CA, United States
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23
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Poitelon Y, Kopec AM, Belin S. Myelin Fat Facts: An Overview of Lipids and Fatty Acid Metabolism. Cells 2020; 9:cells9040812. [PMID: 32230947 PMCID: PMC7226731 DOI: 10.3390/cells9040812] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/11/2022] Open
Abstract
Myelin is critical for the proper function of the nervous system and one of the most complex cell–cell interactions of the body. Myelination allows for the rapid conduction of action potentials along axonal fibers and provides physical and trophic support to neurons. Myelin contains a high content of lipids, and the formation of the myelin sheath requires high levels of fatty acid and lipid synthesis, together with uptake of extracellular fatty acids. Recent studies have further advanced our understanding of the metabolism and functions of myelin fatty acids and lipids. In this review, we present an overview of the basic biology of myelin lipids and recent insights on the regulation of fatty acid metabolism and functions in myelinating cells. In addition, this review may serve to provide a foundation for future research characterizing the role of fatty acids and lipids in myelin biology and metabolic disorders affecting the central and peripheral nervous system.
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24
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Hartley MD, Shokat MD, DeBell MJ, Banerji T, Kirkemo LL, Scanlan TS. Pharmacological Complementation Remedies an Inborn Error of Lipid Metabolism. Cell Chem Biol 2020; 27:551-559.e4. [PMID: 32169163 DOI: 10.1016/j.chembiol.2020.02.008] [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: 11/20/2019] [Revised: 01/27/2020] [Accepted: 02/26/2020] [Indexed: 01/06/2023]
Abstract
X-linked adrenoleukodystrophy (X-ALD) is a rare, genetic disease in which increased very long chain fatty acids (VLCFAs) in the central nervous system (CNS) cause demyelination and axonopathy, leading to neurological deficits. Sobetirome, a potent thyroid hormone agonist, has been shown to lower VLCFAs in the periphery and CNS. In this study, two pharmacological strategies for enhancing the effects of sobetirome were tested in Abcd1 KO mice, a murine model with the same inborn error of metabolism as X-ALD patients. First, a sobetirome prodrug (Sob-AM2) with increased CNS penetration lowered CNS VLCFAs more potently than sobetirome and was better tolerated with reduced peripheral exposure. Second, co-administration of thyroid hormone with sobetirome enhanced VLCFA lowering in the periphery but did not produce greater lowering in the CNS. These data support the conclusion that CNS VLCFA lowering in Abcd1 knockout mice is limited by a mechanistic threshold related to slow lipid turnover.
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Affiliation(s)
- Meredith D Hartley
- Program in Chemical Biology and Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97206, USA
| | - Mitra D Shokat
- Program in Chemical Biology and Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97206, USA
| | - Margaret J DeBell
- Program in Chemical Biology and Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97206, USA
| | - Tania Banerji
- Program in Chemical Biology and Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97206, USA
| | - Lisa L Kirkemo
- Program in Chemical Biology and Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97206, USA
| | - Thomas S Scanlan
- Program in Chemical Biology and Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97206, USA.
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25
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Comorbidities of HIV infection: role of Nef-induced impairment of cholesterol metabolism and lipid raft functionality. AIDS 2020; 34:1-13. [PMID: 31789888 PMCID: PMC6903377 DOI: 10.1097/qad.0000000000002385] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Combination antiretroviral therapy has dramatically changed the outcome of HIV infection, turning it from a death sentence to a manageable chronic disease. However, comorbidities accompanying HIV infection, such as metabolic and cardio-vascular diseases, as well as cognitive impairment, persist despite successful virus control by combination antiretroviral therapy and pose considerable challenges to clinical management of people living with HIV. These comorbidities involve a number of pathological processes affecting a variety of different tissues and cells, making it challenging to identify a common cause(s) that would link these different diseases to HIV infection. In this article, we will present evidence that impairment of cellular cholesterol metabolism may be a common factor driving pathogenesis of HIV-associated comorbidities. Potential implications for therapeutic approaches are discussed.
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26
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Neuronal activity and microglial activation support corticospinal tract and proprioceptive afferent sprouting in spinal circuits after a corticospinal system lesion. Exp Neurol 2019; 321:113015. [PMID: 31326353 DOI: 10.1016/j.expneurol.2019.113015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 05/12/2019] [Accepted: 07/17/2019] [Indexed: 12/17/2022]
Abstract
Spared corticospinal tract (CST) and proprioceptive afferent (PA) axons sprout after injury and contribute to rewiring spinal circuits, affecting motor recovery. Loss of CST connections post-injury results in corticospinal signal loss and associated reduction in spinal activity. We investigated the role of activity loss and injury on CST and PA sprouting. To understand activity-dependence after injury, we compared CST and PA sprouting after motor cortex (MCX) inactivation, produced by chronic MCX muscimol microinfusion, with sprouting after a CST lesion produced by pyramidal tract section (PTx). Activity suppression, which does not produce a lesion, is sufficient to trigger CST axon outgrowth from the active side to cross the midline and to enter the inactivated side of the spinal cord, to the same extent as PTx. Activity loss was insufficient to drive significant CST gray matter axon elongation, an effect of PTx. Activity suppression triggered presynaptic site formation, but less than PTx. Activity loss triggered PA sprouting, as PTx. To understand injury-dependent sprouting further, we blocked microglial activation and associated inflammation after PTX by chronic minocycline administration after PTx. Minocycline inhibited myelin debris phagocytosis contralateral to PTx and abolished CST axon elongation, formation of presynaptic sites, and PA sprouting, but not CST axon outgrowth from the active side to cross the midline. Our findings suggest sprouting after injury has a strong activity dependence and that microglial activation after injury supports axonal elongation and presynaptic site formation. Combining spinal activity support and inflammation control is potentially more effective in promoting functional restoration than either alone.
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27
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Kleinridders A, Ferris HA, Reyzer ML, Rath M, Soto M, Manier ML, Spraggins J, Yang Z, Stanton RC, Caprioli RM, Kahn CR. Regional differences in brain glucose metabolism determined by imaging mass spectrometry. Mol Metab 2018; 12:113-121. [PMID: 29681509 PMCID: PMC6001904 DOI: 10.1016/j.molmet.2018.03.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/15/2018] [Accepted: 03/24/2018] [Indexed: 12/29/2022] Open
Abstract
Objective Glucose is the major energy substrate of the brain and crucial for normal brain function. In diabetes, the brain is subject to episodes of hypo- and hyperglycemia resulting in acute outcomes ranging from confusion to seizures, while chronic metabolic dysregulation puts patients at increased risk for depression and Alzheimer's disease. In the present study, we aimed to determine how glucose is metabolized in different regions of the brain using imaging mass spectrometry (IMS). Methods To examine the relative abundance of glucose and other metabolites in the brain, mouse brain sections were subjected to imaging mass spectrometry at a resolution of 100 μm. This was correlated with immunohistochemistry, qPCR, western blotting and enzyme assays of dissected brain regions to determine the relative contributions of the glycolytic and pentose phosphate pathways to regional glucose metabolism. Results In brain, there are significant regional differences in glucose metabolism, with low levels of hexose bisphosphate (a glycolytic intermediate) and high levels of the pentose phosphate pathway (PPP) enzyme glucose-6-phosphate dehydrogenase (G6PD) and PPP metabolite hexose phosphate in thalamus compared to cortex. The ratio of ATP to ADP is significantly higher in white matter tracts, such as corpus callosum, compared to less myelinated areas. While the brain is able to maintain normal ratios of hexose phosphate, hexose bisphosphate, ATP, and ADP during fasting, fasting causes a large increase in cortical and hippocampal lactate. Conclusion These data demonstrate the importance of direct measurement of metabolic intermediates to determine regional differences in brain glucose metabolism and illustrate the strength of imaging mass spectrometry for investigating the impact of changing metabolic states on brain function at a regional level with high resolution. Utilization of glucose for glycolysis or the pentose phosphate pathway (PPP) is region-specific. IMS allows simultaneous measurement of glucose metabolites across brain regions. PPP is high in thalamus, while glycolysis predominates in cortex and amygdala. Fasting induces changes in lactate distribution but not glucose metabolites or ATP.
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Affiliation(s)
- André Kleinridders
- Department of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA; German Institute of Human Nutrition, Central Regulation of Metabolism, Arthur-Scheunert-Allee 114-116, Potsdam-Rehbruecke, Nuthetal, Germany; German Center for Diabetes Research (DZD), Ingolstaedter Land Str. 1, 85764 Neuherberg, Germany.
| | - Heather A Ferris
- Department of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Michelle L Reyzer
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37240, USA
| | - Michaela Rath
- German Institute of Human Nutrition, Central Regulation of Metabolism, Arthur-Scheunert-Allee 114-116, Potsdam-Rehbruecke, Nuthetal, Germany; German Center for Diabetes Research (DZD), Ingolstaedter Land Str. 1, 85764 Neuherberg, Germany
| | - Marion Soto
- Department of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - M Lisa Manier
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37240, USA
| | - Jeffrey Spraggins
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37240, USA
| | - Zhihong Yang
- Department of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Robert C Stanton
- Department of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Richard M Caprioli
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37240, USA
| | - C Ronald Kahn
- Department of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA.
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28
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Bergholt MS, Serio A, McKenzie JS, Boyd A, Soares RF, Tillner J, Chiappini C, Wu V, Dannhorn A, Takats Z, Williams A, Stevens MM. Correlated Heterospectral Lipidomics for Biomolecular Profiling of Remyelination in Multiple Sclerosis. ACS CENTRAL SCIENCE 2018; 4:39-51. [PMID: 29392175 PMCID: PMC5785772 DOI: 10.1021/acscentsci.7b00367] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Indexed: 05/22/2023]
Abstract
Analyzing lipid composition and distribution within the brain is important to study white matter pathologies that present focal demyelination lesions, such as multiple sclerosis. Some lesions can endogenously re-form myelin sheaths. Therapies aim to enhance this repair process in order to reduce neurodegeneration and disability progression in patients. In this context, a lipidomic analysis providing both precise molecular classification and well-defined localization is crucial to detect changes in myelin lipid content. Here we develop a correlated heterospectral lipidomic (HSL) approach based on coregistered Raman spectroscopy, desorption electrospray ionization mass spectrometry (DESI-MS), and immunofluorescence imaging. We employ HSL to study the structural and compositional lipid profile of demyelination and remyelination in an induced focal demyelination mouse model and in multiple sclerosis lesions from patients ex vivo. Pixelwise coregistration of Raman spectroscopy and DESI-MS imaging generated a heterospectral map used to interrelate biomolecular structure and composition of myelin. Multivariate regression analysis enabled Raman-based assessment of highly specific lipid subtypes in complex tissue for the first time. This method revealed the temporal dynamics of remyelination and provided the first indication that newly formed myelin has a different lipid composition compared to normal myelin. HSL enables detailed molecular myelin characterization that can substantially improve upon the current understanding of remyelination in multiple sclerosis and provides a strategy to assess remyelination treatments in animal models.
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Affiliation(s)
- Mads S. Bergholt
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
| | - Andrea Serio
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
| | - James S. McKenzie
- Computational
and Systems Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Amanda Boyd
- MRC
Centre for Regenerative Medicine, University
of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Renata F. Soares
- Computational
and Systems Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jocelyn Tillner
- Computational
and Systems Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Ciro Chiappini
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
| | - Vincen Wu
- Computational
and Systems Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Andreas Dannhorn
- Computational
and Systems Medicine, Imperial College London, London SW7 2AZ, United Kingdom
| | - Zoltan Takats
- Computational
and Systems Medicine, Imperial College London, London SW7 2AZ, United Kingdom
- E-mail:
| | - Anna Williams
- MRC
Centre for Regenerative Medicine, University
of Edinburgh, Edinburgh EH16 4UU, United Kingdom
- E-mail:
| | - Molly M. Stevens
- Department
of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- Department
of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
- Institute
of Biomedical Engineering, Imperial College
London, London SW7 2AZ, United Kingdom
- E-mail:
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29
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Figlia G, Gerber D, Suter U. Myelination and mTOR. Glia 2017; 66:693-707. [PMID: 29210103 PMCID: PMC5836902 DOI: 10.1002/glia.23273] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/08/2017] [Accepted: 11/17/2017] [Indexed: 02/06/2023]
Abstract
Myelinating cells surround axons to accelerate the propagation of action potentials, to support axonal health, and to refine neural circuits. Myelination is metabolically demanding and, consistent with this notion, mTORC1—a signaling hub coordinating cell metabolism—has been implicated as a key signal for myelination. Here, we will discuss metabolic aspects of myelination, illustrate the main metabolic processes regulated by mTORC1, and review advances on the role of mTORC1 in myelination of the central nervous system and the peripheral nervous system. Recent progress has revealed a complex role of mTORC1 in myelinating cells that includes, besides positive regulation of myelin growth, additional critical functions in the stages preceding active myelination. Based on the available evidence, we will also highlight potential nonoverlapping roles between mTORC1 and its known main upstream pathways PI3K‐Akt, Mek‐Erk1/2, and AMPK in myelinating cells. Finally, we will discuss signals that are already known or hypothesized to be responsible for the regulation of mTORC1 activity in myelinating cells. Myelination is metabolically demanding. The metabolic regulator mTORC1 controls differentiation of myelinating cells and promotes myelin
growth. mTORC1‐independent targets of the PI3K‐Akt and Mek‐Erk1/2 pathways may also be significant in myelination.
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Affiliation(s)
- Gianluca Figlia
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH 8093, Switzerland
| | - Daniel Gerber
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH 8093, Switzerland
| | - Ueli Suter
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH 8093, Switzerland
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30
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Chevalier AC, Rosenberger TA. Increasing acetyl-CoA metabolism attenuates injury and alters spinal cord lipid content in mice subjected to experimental autoimmune encephalomyelitis. J Neurochem 2017; 141:721-737. [PMID: 28369944 DOI: 10.1111/jnc.14032] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 03/15/2017] [Accepted: 03/19/2017] [Indexed: 12/28/2022]
Abstract
Acetate supplementation increases brain acetyl-CoA metabolism, alters histone and non-histone protein acetylation, increases brain energy reserves, and is anti-inflammatory and neuroprotective in rat models of neuroinflammation and neuroborreliosis. To determine the impact acetate supplementation has on a mouse model of multiple sclerosis, we quantified the effect treatment had on injury progression, spinal cord lipid content, phospholipase levels, and myelin structure in mice subjected to experimental autoimmune encephalomyelitis (EAE). EAE was induced by inoculating mice with a myelin oligodendrocyte glycoprotein peptide fragment (MOG35-55 ), and acetate supplementation was maintained with 4 g/kg glyceryl triacetate by a daily oral gavage. Acetate supplementation prevented the onset of clinical signs in mice subject to EAE compared to control-treated mice. Furthermore, acetate supplementation prevented the loss of spinal cord ethanolamine and choline glycerophospholipid and phosphatidylserine in mice subjected to EAE compared to EAE animals treated with water. Treatment increased saturated and monounsaturated fatty acid levels in phosphatidylserine compared to controls suggesting that acetate was utilized to increase spinal cord fatty acid content. Also, acetate supplementation prevented the loss of spinal cord cholesterol in EAE animals but did not change cholesteryl esters. Treatment significantly increased GD3 and GD1a ganglioside levels in EAE mice when compared to EAE mice treated with water. Treatment returned levels of phosphorylated and non-phosphorylated cytosolic phospholipase A2 (cPLA2 ) levels back to baseline and based on FluoroMyelin™ histochemistry maintained myelin structural characteristics. Overall, these data suggest that acetate supplementation may modulate lipid metabolism in mice subjected to EAE.
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Affiliation(s)
- Amber C Chevalier
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
| | - Thad A Rosenberger
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota, USA
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31
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Hartley MD, Kirkemo LL, Banerji T, Scanlan TS. A Thyroid Hormone-Based Strategy for Correcting the Biochemical Abnormality in X-Linked Adrenoleukodystrophy. Endocrinology 2017; 158:1328-1338. [PMID: 28200172 PMCID: PMC5460829 DOI: 10.1210/en.2016-1842] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/09/2017] [Indexed: 02/05/2023]
Abstract
X-linked adrenoleukodystrophy (X-ALD) is a rare, genetic disorder characterized by adrenal insufficiency and central nervous system (CNS) demyelination. All patients with X-ALD have the biochemical abnormality of elevated blood and tissue levels of very long chain fatty acids (VLCFAs), saturated fatty acids with 24 to 26 carbons. X-ALD results from loss of function mutations in the gene encoding the peroxisomal transporter ABCD1, which is responsible for uptake of VLCFAs into peroxisomes for degradation by oxidation. One proposed therapeutic strategy for genetic complementation of ABCD1 is pharmacologic upregulation of ABCD2, a gene encoding a homologous peroxisomal transporter. Here, we show that thyroid hormone or sobetirome, a clinical-stage selective thyroid hormone receptor agonist, increases cerebral Abcd2 and lowers VLCFAs in blood, peripheral organs, and brains of mice with defective Abcd1. These results support an approach to treating X-ALD that involves a thyromimetic agent that reactivates VLCFA disposal both in the periphery and the CNS.
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Affiliation(s)
- Meredith D. Hartley
- Department of Physiology and Pharmacology and Program in Chemical Biology, Oregon Health & Science University, Portland, Oregon 92739
| | - Lisa L. Kirkemo
- Department of Physiology and Pharmacology and Program in Chemical Biology, Oregon Health & Science University, Portland, Oregon 92739
| | - Tapasree Banerji
- Department of Physiology and Pharmacology and Program in Chemical Biology, Oregon Health & Science University, Portland, Oregon 92739
| | - Thomas S. Scanlan
- Department of Physiology and Pharmacology and Program in Chemical Biology, Oregon Health & Science University, Portland, Oregon 92739
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32
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Yehuda S, Rabinovitz S. The Role of Essential Fatty Acids in Anorexia Nervosa and Obesity. Crit Rev Food Sci Nutr 2017; 56:2021-35. [PMID: 26068122 DOI: 10.1080/10408398.2013.809690] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The two basic questions in food intake study are what we eat, and how much do we eat. Most research is directed toward the control of how much is eaten. This is likely the result of the increased number of individuals with eating disorders in the Western world. Feeding behavior is highly complex, and is controlled by many psychological, physiological, biochemical, and immunological factors. The aim of this review is to clarify the involvement of fatty acids in eating disorders such as anorexia and binge eating disorder. The review will describe the modified fatty acid profile observed in individuals with anorexia or binge eating disorder, and discuss on what factors fatty acids can exert beneficial effects. In addition, the differences and similarities between anorexia and binge eating disorder will be discussed. We suggest that beneficial effects of essential fatty acids on both anorexia and binge eating disorder can be explained by the stabilizing effect of those fatty acids on the neuronal membrane fluidity index.
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Affiliation(s)
- Shlomo Yehuda
- a Psychopharmacology Lab , Department of Psychology, Bar Ilan University , Ramat Gan , Israel
| | - Sharon Rabinovitz
- a Psychopharmacology Lab , Department of Psychology, Bar Ilan University , Ramat Gan , Israel.,b School of Criminology, University of Haifa , Mount Carmel , Israel
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33
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Kanhai K, Goulooze SC, Stevens J, Hay JL, Dent G, Verma A, Hankemeier T, de Boer T, Meijering H, Chavez JC, Cohen AF, Groeneveld GJ. Quantifying Beta-Galactosylceramide Kinetics in Cerebrospinal Fluid of Healthy Subjects Using Deuterium Labeling. Clin Transl Sci 2016; 9:321-327. [PMID: 27743499 PMCID: PMC5351000 DOI: 10.1111/cts.12424] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/08/2016] [Indexed: 12/12/2022] Open
Abstract
Therapeutics promoting myelin synthesis may enhance recovery in demyelinating diseases, such as multiple sclerosis. However, no suitable method exists to quantify myelination. The turnover of galactosylceramide (myelin component) is indicative of myelination in mice, but its turnover has not been determined in humans. Here, six healthy subjects consumed 120 mL 70% D2O daily for 70 days to label galactosylceramide. We then used mass spectrometry and compartmental modeling to quantify the turnover rate of galactosylceramide in cerebrospinal fluid. Maximum deuterium enrichment of body water ranged from 1.5–3.9%, whereas that of galactosylceramide was much lower: 0.05–0.14%. This suggests a slow turnover rate, which was confirmed by the model‐estimated galactosylceramide turnover rate of 0.00168 day−1, which corresponds to a half‐life of 413 days. Additional studies in patients with multiple sclerosis are needed to investigate whether galactosylceramide turnover could be used as an outcome measure in clinical trials with remyelination therapies.
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Affiliation(s)
- Kms Kanhai
- Centre for Human Drug Research, Leiden, The Netherlands
| | - S C Goulooze
- Centre for Human Drug Research, Leiden, The Netherlands
| | - J Stevens
- Centre for Human Drug Research, Leiden, The Netherlands
| | - J L Hay
- Centre for Human Drug Research, Leiden, The Netherlands
| | - G Dent
- Experimental Medicine, Biogen Cambridge, Massachusetts, USA
| | - A Verma
- Experimental Medicine, Biogen Cambridge, Massachusetts, USA
| | - T Hankemeier
- Netherlands Metabolomics Centre, Leiden, The Netherlands
| | - T de Boer
- Analytical Biochemical Laboratory BV, Assen, The Netherlands
| | - H Meijering
- Analytical Biochemical Laboratory BV, Assen, The Netherlands
| | - J C Chavez
- Experimental Medicine, Biogen Cambridge, Massachusetts, USA
| | - A F Cohen
- Centre for Human Drug Research, Leiden, The Netherlands
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Abstract
Fish oil originates from fish tissue rich in omega-3 fatty acids. These include eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Healthy individuals are advised to consume foods rich in fish oil at least twice a week. However, such intake varies depending on cultural or personal preference, and socio-economic status. Many families and patients with chronic neurological conditions consume supplements containing omega-3 fatty acids. We are frequently requested to give advice and recommendations on using such agents to help improve neurological developmental and cognitive functions. The objective of this review is to discuss the available literature supporting the role of fish oils on brain development and function. There is a growing body of literature suggesting a potential benefit of long chain polyunsaturated fatty acids; however it is still unclear if there are response variations according to the developmental stage, age, and dose. L'influence de l'huile de poisson sur le développement et la fonction neurologique. L'huile de poisson provient de tissus de poisson riches en acides gras oméga-3, l'acide eicosapentaéno&IUque (EPA) et l'acide docosahexaénoïque (DHA). On conseille aux individus en bonne santé de consommer des aliments riches en huiles de poisson au moins deux fois par semaine. Cependant, leur consommation varie selon les préférences culturelles ou personnelles ainsi que selon le statut socio-économique. Plusieurs familles et plusieurs patients atteints de maladies neurologiques chroniques consomment des suppléments contenant des acides gras oméga-3. On nous demande souvent des conseils et des recommandations sur l'utilisation de ces agents pour aider à améliorer le développement neurologique et les fonctions cognitives. L'objectif de cette revue est de discuter de la littérature disponible en faveur du rôle des huiles de poisson dans le développement et le fonctionnement du cerveau. Il existe une documentation de plus en plus importante qui suggère que les acides gras polyinsaturés à longue chaîne pourraient ětre bénéfiques. Cependant, on ne sait pas si la réponse peut varier selon le stade du développement, l'âge et la dose.
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Reis MM, Bermingham EN, Reis MG, Deb-Choudhury S, MacGibbon A, Fong B, McJarrow P, Bibiloni R, Bassett SA, Roy NC. Effect of Dietary Complex Lipids on the Biosynthesis of Piglet Brain Gangliosides. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:1245-1255. [PMID: 26808587 DOI: 10.1021/acs.jafc.5b05211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Gangliosides, found in mammalian milk, are known for their roles in brain development of the newborn. However, the mechanism involved in the impact of dietary gangliosides on brain metabolism is not fully understood. The impact of diets containing complex lipids rich in milk-derived ganglioside GD3 on the biosynthesis of gangliosides (assessed from the incorporation of deuterium) in the frontal lobe of a piglet model is reported. Higher levels of incorporation of deuterium was observed in the GM1 and GD1a containing stearic acid in samples from piglets fed milk containing 18.2 μg/mL of GD3 compared to that in those fed milk containing 25 μg/mL of GD3. This could suggest that the gangliosides from the diet may be used as a precursor for de novo biosynthesis of brain gangliosides or lead to the reduction of de novo biosynthesis of these gangliosides. This effect was more pronounced in the left compared to that in the right brain hemisphere.
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Affiliation(s)
- Marlon M Reis
- Food Assurance & Meat Quality Team, Food & Bio-Based Products Group, AgResearch Ruakura , Hamilton 3240, New Zealand
| | - Emma N Bermingham
- Food Nutrition & Health Team, Food & Bio-Based Products Group, AgResearch Grasslands , Palmerston North 4442, New Zealand
| | - Mariza G Reis
- Dairy Foods Team, Food & Bio-Based Products Group, AgResearch Ruakura , Hamilton 3240, New Zealand
| | | | - Alastair MacGibbon
- Fonterra Research and Development Centre , Palmerston North 4442, New Zealand
| | - Bertram Fong
- Fonterra Research and Development Centre , Palmerston North 4442, New Zealand
| | - Paul McJarrow
- Fonterra Research and Development Centre , Palmerston North 4442, New Zealand
| | - Rodrigo Bibiloni
- Food Nutrition & Health Team, Food & Bio-Based Products Group, AgResearch Grasslands , Palmerston North 4442, New Zealand
| | - Shalome A Bassett
- Food Nutrition & Health Team, Food & Bio-Based Products Group, AgResearch Grasslands , Palmerston North 4442, New Zealand
| | - Nicole C Roy
- Food Nutrition & Health Team, Food & Bio-Based Products Group, AgResearch Grasslands , Palmerston North 4442, New Zealand
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Raddatz BB, Sun W, Brogden G, Sun Y, Kammeyer P, Kalkuhl A, Colbatzky F, Deschl U, Naim HY, Baumgärtner W, Ulrich R. Central Nervous System Demyelination and Remyelination is Independent from Systemic Cholesterol Level in Theiler's Murine Encephalomyelitis. Brain Pathol 2015; 26:102-19. [PMID: 25959295 DOI: 10.1111/bpa.12266] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/29/2015] [Indexed: 12/18/2022] Open
Abstract
High dietary fat and/or cholesterol intake is a risk factor for multiple diseases and has been debated for multiple sclerosis. However, cholesterol biosynthesis is a key pathway during myelination and disturbances are described in demyelinating diseases. To address the possible interaction of dyslipidemia and demyelination, cholesterol biosynthesis gene expression, composition of the body's major lipid repositories and Paigen diet-induced, systemic hypercholesterolemia were examined in Theiler's murine encephalomyelitis (TME) using histology, immunohistochemistry, serum clinical chemistry, microarrays and high-performance thin layer chromatography. TME-virus (TMEV)-infected mice showed progressive loss of motor performance and demyelinating leukomyelitis. Gene expression associated with cholesterol biosynthesis was overall down-regulated in the spinal cord of TMEV-infected animals. Spinal cord levels of galactocerebroside and sphingomyelin were reduced on day 196 post TMEV infection. Paigen diet induced serum hypercholesterolemia and hepatic lipidosis. However, high dietary fat and cholesterol intake led to no significant differences in clinical course, inflammatory response, astrocytosis, and the amount of demyelination and remyelination in the spinal cord of TMEV-infected animals. The results suggest that down-regulation of cholesterol biosynthesis is a transcriptional marker for demyelination, quantitative loss of myelin-specific lipids, but not cholesterol occurs late in chronic demyelination, and serum hypercholesterolemia exhibited no significant effect on TMEV infection.
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Affiliation(s)
- Barbara B Raddatz
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Wenhui Sun
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Graham Brogden
- Fish Disease Research Unit, University of Veterinary Medicine Hannover, Hannover, Germany.,Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Yanyong Sun
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Patricia Kammeyer
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Arno Kalkuhl
- Department of Non-Clinical Drug Safety, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach (Riß), Germany
| | - Florian Colbatzky
- Department of Non-Clinical Drug Safety, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach (Riß), Germany
| | - Ulrich Deschl
- Department of Non-Clinical Drug Safety, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach (Riß), Germany
| | - Hassan Y Naim
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Reiner Ulrich
- Department of Pathology, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany
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Vanmierlo T, Bogie JF, Mailleux J, Vanmol J, Lütjohann D, Mulder M, Hendriks JJ. Plant sterols: Friend or foe in CNS disorders? Prog Lipid Res 2015; 58:26-39. [DOI: 10.1016/j.plipres.2015.01.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 12/21/2022]
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38
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Saher G, Stumpf SK. Cholesterol in myelin biogenesis and hypomyelinating disorders. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1083-94. [PMID: 25724171 DOI: 10.1016/j.bbalip.2015.02.010] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/05/2015] [Accepted: 02/12/2015] [Indexed: 02/05/2023]
Abstract
The largest pool of free cholesterol in mammals resides in myelin membranes. Myelin facilitates rapid saltatory impulse propagation by electrical insulation of axons. This function is achieved by ensheathing axons with a tightly compacted stack of membranes. Cholesterol influences myelination at many steps, from the differentiation of myelinating glial cells, over the process of myelin membrane biogenesis, to the functionality of mature myelin. Cholesterol emerged as the only integral myelin component that is essential and rate-limiting for the development of myelin in the central and peripheral nervous system. Moreover, disorders that interfere with sterol synthesis or intracellular trafficking of cholesterol and other lipids cause hypomyelination and neurodegeneration. This review summarizes recent results on the roles of cholesterol in CNS myelin biogenesis in normal development and under different pathological conditions. This article is part of a Special Issue entitled Brain Lipids.
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Affiliation(s)
- Gesine Saher
- Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
| | - Sina Kristin Stumpf
- Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
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39
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Transcriptional analysis of glial cell differentiation in the postnatal murine spinal cord. Int J Dev Neurosci 2015; 42:24-36. [PMID: 25702526 DOI: 10.1016/j.ijdevneu.2015.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/28/2015] [Accepted: 02/14/2015] [Indexed: 11/20/2022] Open
Abstract
Postnatal murine spinal cord represents a good model system to study mammalian central nervous system myelination in vivo as a basis for further studies in demyelinating diseases. Transcriptional changes were analyzed in SJL/J mice on postnatal day 0, 14, 49 and 231 (P0, P14, P49, P231) employing Affymetrix GeneChip Mouse Genome 430 2.0 Arrays. Additionally, marker gene signatures for astrocyte and oligodendrocyte lineage-stages were defined to study their gene expression in more detail. In addition, immunohistochemistry was used to quantify the abundance of commonly used glial cell markers. 6092 differentially regulated genes (DEGs) were identified. The up-regulated DEGs at P14, P49 and P231 compared to P0 exhibited significantly enriched associations to gene ontology terms such as myelination and lipid metabolic transport and down-regulated DEGs to neurogenesis and axonogenesis. Expression values of marker gene signatures for neural stem cells, oligodendrocyte precursor cells, and developing astrocytes were constantly decreasing, whereas myelinating oligodendrocyte and mature astrocyte markers showed a steady increase. Molecular findings were substantiated by immunohistochemical observations. The transcriptional changes observed are an important reference for future analysis of degenerative and inflammatory conditions in the spinal cord.
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40
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Heinecke KA, Luoma A, d'Azzo A, Kirschner DA, Seyfried TN. Myelin abnormalities in the optic and sciatic nerves in mice with GM1-gangliosidosis. ASN Neuro 2015; 7:7/1/1759091415568913. [PMID: 25694553 PMCID: PMC4342369 DOI: 10.1177/1759091415568913] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
GM1-gangliosidosis is a glycosphingolipid lysosomal storage disease involving accumulation of GM1 and its asialo form (GA1) primarily in the brain. Thin-layer chromatography and X-ray diffraction were used to analyze the lipid content/composition and the myelin structure of the optic and sciatic nerves from 7- and 10-month old β-galactosidase (β-gal) +/? and β-gal −/− mice, a model of GM1gangliosidosis. Optic nerve weight was lower in the β-gal −/− mice than in unaffected β-gal +/? mice, but no difference was seen in sciatic nerve weight. The levels of GM1 and GA1 were significantly increased in both the optic nerve and sciatic nerve of the β-gal −/− mice. The content of myelin-enriched cerebrosides, sulfatides, and plasmalogen ethanolamines was significantly lower in optic nerve of β-gal −/− mice than in β-gal +/? mice; however, cholesteryl esters were enriched in the β-gal −/− mice. No major abnormalities in these lipids were detected in the sciatic nerve of the β-gal −/− mice. The abnormalities in GM1 and myelin lipids in optic nerve of β-gal −/− mice correlated with a reduction in the relative amount of myelin and periodicity in fresh nerve. By contrast, the relative amount of myelin and periodicity in the sciatic nerves from control and β-gal −/− mice were indistinguishable, suggesting minimal pathological involvement in sciatic nerve. Our results indicate that the greater neurochemical pathology observed in the optic nerve than in the sciatic nerve of β-gal −/− mice is likely due to the greater glycolipid storage in optic nerve.
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Affiliation(s)
| | - Adrienne Luoma
- Department of Biology, Boston College, Chestnut Hill, MA, USA Department of Biochemistry and Molecular Biology, Committee on Immunology, University of Chicago, IL, USA
| | - Alessandra d'Azzo
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, USA
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41
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Role of ERK1/2 MAPK signaling in the maintenance of myelin and axonal integrity in the adult CNS. J Neurosci 2015; 34:16031-45. [PMID: 25429144 DOI: 10.1523/jneurosci.3360-14.2014] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Oligodendrocytes form myelin during postnatal development and then maintain a functional myelin sheath throughout adult life. While many regulators of developmental myelination have been identified, the signal transduction mechanisms that regulate oligodendrocyte functions in adulthood are not well understood. The extracellular signal-regulated kinases-1 and -2 (ERK1/2), downstream mediators of mitogen-activated protein kinases (MAPKs), have emerged as prominent regulators of myelin formation. Here, we investigated whether these signaling molecules are also required for myelin maintenance in the adult CNS. Inducible conditional ablation of Erk1/2 in oligodendrocytes of the adult CNS resulted in a downregulation of myelin gene expression. Although myelin thickness was reduced and some axons were demyelinated, the majority of axons were wrapped by intact myelin sheaths that appeared structurally normal. However, late onset of progressive axonal degeneration, accompanied by astrogliosis, microglial activation, partial loss of oligodendrocytes, and functional impairment, occurred in the adult mice lacking ERK1/2 activity. Conditional ablation of Fibroblast Growth Factor receptors-1 and -2 (FGFR1/2) in oligodendrocytes also resulted in downregulation of myelin gene expression and development of axonal degeneration as the mice aged. Further, the level of the key transcription factor myelin gene regulatory factor (Myrf) was downregulated or upregulated in mice with genetic loss or gain of ERK1/2 function, respectively. Together, our studies demonstrate that ERK1/2-MAPK signaling is required for the long-term maintenance of myelin and axonal integrity in the adult CNS and suggest that FGFR1/2 and Myrf may, in part, contribute to signaling upstream and downstream of ERK1/2 in maintaining these oligodendrocyte functions during adulthood.
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42
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Wong JH, Halliday GM, Kim WS. Exploring myelin dysfunction in multiple system atrophy. Exp Neurobiol 2014; 23:337-44. [PMID: 25548533 PMCID: PMC4276804 DOI: 10.5607/en.2014.23.4.337] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 10/15/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022] Open
Abstract
Multiple system atrophy (MSA) is a rare, yet fatal neurodegenerative disease that presents clinically with autonomic failure in combination with parkinsonism or cerebellar ataxia. MSA impacts on the autonomic nervous system affecting blood pressure, heart rate and bladder function, and the motor system affecting balance and muscle movement. The cause of MSA is unknown, no definitive risk factors have been identified, and there is no cure or effective treatment. The definitive pathology of MSA is the presence of α-synuclein aggregates in the brain and therefore MSA is classified as an α-synucleinopathy, together with Parkinson's disease and dementia with Lewy bodies. Although the molecular mechanisms of misfolding, fibrillation and aggregation of α-synuclein partly overlap with other α-synucleinopathies, the pathological pathway of MSA is unique in that the principal site for α-synuclein deposition is in the oligodendrocytes rather than the neurons. The sequence of pathological events of MSA is now recognized as abnormal protein redistributions in oligodendrocytes first, followed by myelin dysfunction and then neurodegeneration. Oligodendrocytes are responsible for the production and maintenance of myelin, the specialized lipid membrane that encases the axons of all neurons in the brain. Myelin is composed of lipids and two prominent proteins, myelin basic protein and proteolipid protein. In vitro studies suggest that aberration in protein distribution and lipid transport may lead to myelin dysfunction in MSA. The purpose of this perspective is to bring together available evidence to explore the potential role of α-synuclein, myelin protein dysfunction, lipid dyshomeostasis and ABCA8 in MSA pathogenesis.
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Affiliation(s)
- Joanna H Wong
- Neuroscience Research Australia, Sydney, NSW 2031, Australia. ; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Glenda M Halliday
- Neuroscience Research Australia, Sydney, NSW 2031, Australia. ; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Woojin Scott Kim
- Neuroscience Research Australia, Sydney, NSW 2031, Australia. ; School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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43
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Hypomyelination, memory impairment, and blood-brain barrier permeability in a model of sleep apnea. Brain Res 2014; 1597:28-36. [PMID: 25482664 DOI: 10.1016/j.brainres.2014.11.052] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/16/2014] [Accepted: 11/24/2014] [Indexed: 01/28/2023]
Abstract
We investigated the effect of intermittent hypoxia, mimicking sleep apnea, on axonal integrity, blood-brain barrier permeability, and cognitive function of mice. Forty-seven C57BL mice were exposed to intermittent or sham hypoxia, alternating 30s of progressive hypoxia and 30s of reoxigenation, during 8h/day. The axonal integrity in cerebellum was evaluated by transmission electron microscopy. Short- and long-term memories were assessed by novel object recognition test. The levels of endothelin-1 were measured by ELISA. Blood-brain barrier permeability was quantified by Evans Blue dye. After 14 days, animals exposed to intermittent hypoxia showed hypomyelination in cerebellum white matter and higher serum levels of endothelin-1. The short and long-term memories in novel object recognition test was impaired in the group exposed to intermittent hypoxia as compared to controls. Blood-brain barrier permeability was similar between the groups. These results indicated that hypomyelination and impairment of short- and long-term working memories occurred in C57BL mice after 14 days of intermittent hypoxia mimicking sleep apnea.
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44
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Denninger AR, Demé B, Cristiglio V, LeDuc G, Feller WB, Kirschner DA. Neutron scattering from myelin revisited: bilayer asymmetry and water-exchange kinetics. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:3198-211. [PMID: 25478838 PMCID: PMC4257619 DOI: 10.1107/s1399004714023815] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/28/2014] [Indexed: 11/18/2022]
Abstract
Rapid nerve conduction in the central and peripheral nervous systems (CNS and PNS, respectively) of higher vertebrates is brought about by the ensheathment of axons with myelin, a lipid-rich, multilamellar assembly of membranes. The ability of myelin to electrically insulate depends on the regular stacking of these plasma membranes and on the presence of a number of specialized membrane-protein assemblies in the sheath, including the radial component, Schmidt-Lanterman incisures and the axo-glial junctions of the paranodal loops. The disruption of this fine-structure is the basis for many demyelinating neuropathies in the CNS and PNS. Understanding the processes that govern myelin biogenesis, maintenance and destabilization requires knowledge of myelin structure; however, the tight packing of internodal myelin and the complexity of its junctional specializations make myelin a challenging target for comprehensive structural analysis. This paper describes an examination of myelin from the CNS and PNS using neutron diffraction. This investigation revealed the dimensions of the bilayers and aqueous spaces of myelin, asymmetry between the cytoplasmic and extracellular leaflets of the membrane, and the distribution of water and exchangeable hydrogen in internodal multilamellar myelin. It also uncovered differences between CNS and PNS myelin in their water-exchange kinetics.
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Affiliation(s)
| | - Bruno Demé
- Institut Laue–Langevin (ILL), CS 20156, F-38042 Grenoble CEDEX 9, France
| | - Viviana Cristiglio
- Institut Laue–Langevin (ILL), CS 20156, F-38042 Grenoble CEDEX 9, France
| | - Géraldine LeDuc
- European Synchrotron Radiation Facility (ESRF), CS 40220, F-38043 Grenoble CEDEX 9, France
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45
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Abstract
The mammalian target of rapamycin (mTOR) pathway integrates multiple signals and regulates crucial cell functions via the molecular complexes mTORC1 and mTORC2. These complexes are functionally dependent on their raptor (mTORC1) or rictor (mTORC2) subunits. mTOR has been associated with oligodendrocyte differentiation and myelination downstream of the PI3K/Akt pathway, but the functional contributions of individual complexes are largely unknown. We show, by oligodendrocyte-specific genetic deletion of Rptor and/or Rictor in the mouse, that CNS myelination is mainly dependent on mTORC1 function, with minor mTORC2 contributions. Myelin-associated lipogenesis and protein gene regulation are strongly reliant on mTORC1. We found that also oligodendrocyte-specific overactivation of mTORC1, via ablation of tuberous sclerosis complex 1 (TSC1), causes hypomyelination characterized by downregulation of Akt signaling and lipogenic pathways. Our data demonstrate that a delicately balanced regulation of mTORC1 activation and action in oligodendrocytes is essential for CNS myelination, which has practical overtones for understanding CNS myelin disorders.
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Oligodendrocyte loss during the disease course in a canine model of the lysosomal storage disease fucosidosis. J Neuropathol Exp Neurol 2014; 73:536-47. [PMID: 24806306 DOI: 10.1097/nen.0000000000000075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Hypomyelination is a poorly understood feature of many neurodegenerative lysosomal storage diseases, including fucosidosis in children and animals. To gain insight into hypomyelination in fucosidosis, we investigated lysosomal storage, oligodendrocyte death, and axonal and neuron loss in CNS tissues of fucosidosis-affected dogs aged 3 weeks to 42 months using immunohistochemistry, electron microscopy, and gene expression assays. Vacuole accumulation in fucosidosis oligodendrocytes commenced by 5 weeks of age; all oligodendrocytes were affected by 16 weeks. Despite progressive vacuolation, mature oligodendrocyte loss by apoptosis (caspase-6 positive) in the corpus callosum and cerebellar white matter stabilized by 16 weeks, with no further subsequent loss. Axonal neurofilament loss progressed only in late disease, suggesting that disturbed axon-oligodendrocyte interactions are unlikely to be the primary cause of hypomyelination. A 67% decline in the number of Purkinje cell layer oligodendrocytes coincided with a 67% increase in the number of caspase-6-positive Purkinje cells at 16 weeks, suggesting that early oligodendrocyte loss contributes to Purkinje cell apoptosis. Fucosidosis hypomyelination appeared to follow normal spatiotemporal patterns of myelination, with greater loss of oligodendrocytes and larger downregulation of CNP, MAL, and PLP1 genes at 16 weeks in the cerebellum versus the frontal cortex. These studies suggest that survival of oligodendrocytes in fucosidosis is limited during active myelination, although the mechanisms remain unknown.
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Smiljanic K, Vanmierlo T, Djordjevic AM, Perovic M, Loncarevic-Vasiljkovic N, Tesic V, Rakic L, Ruzdijic S, Lutjohann D, Kanazir S. Aging induces tissue-specific changes in cholesterol metabolism in rat brain and liver. Lipids 2013; 48:1069-77. [PMID: 24057446 DOI: 10.1007/s11745-013-3836-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/22/2013] [Indexed: 11/26/2022]
Abstract
Disturbance of cholesterol homeostasis in the brain is coupled to age-related brain dysfunction. In the present work, we studied the relationship between aging and cholesterol metabolism in two brain regions, the cortex and hippocampus, as well as in the sera and liver of 6-, 12-, 18- and 24-month-old male Wistar rats. Using gas chromatography-mass spectrometry, we undertook a comparative analysis of the concentrations of cholesterol, its precursors and metabolites, as well as dietary-derived phytosterols. During aging, the concentrations of the three cholesterol precursors examined (lanosterol, lathosterol and desmosterol) were unchanged in the cortex, except for desmosterol which decreased (44 %) in 18-month-old rats. In the hippocampus, aging was associated with a significant reduction in lanosterol and lathosterol concentrations at 24 months (28 and 25 %, respectively), as well as by a significant decrease of desmosterol concentration at 18 and 24 months (36 and 51 %, respectively). In contrast, in the liver we detected age-induced increases in lanosterol and lathosterol concentrations, and no change in desmosterol concentration. The amounts of these sterols were lower than in the brain regions. In the cortex and hippocampus, desmosterol was the predominant cholesterol precursor. In the liver, lathosterol was the most abundant precursor. This ratio remained stable during aging. The most striking effect of aging observed in our study was a significant decrease in desmosterol concentration in the hippocampus which could reflect age-related reduced synaptic plasticity, thus representing one of the detrimental effects of advanced age.
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Affiliation(s)
- Kosara Smiljanic
- Laboratory of Molecular Neurobiology, Department of Neurobiology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Bulevar despota Stefana 142, 11060, Belgrade, Serbia
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48
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Meyer MA. Delayed post-hypoxic leukoencephalopathy: case report with a review of disease pathophysiology. Neurol Int 2013; 5:e13. [PMID: 24147210 PMCID: PMC3794448 DOI: 10.4081/ni.2013.e13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/10/2013] [Indexed: 11/23/2022] Open
Abstract
Delayed post-hypoxic leukoencephalopathy is a rare clinical phenomenon usually observed in a small number of carbon monoxide poisoning survivors. A similar phenomenon is reported here in a patient who successfully recovered from a large overdose of diazepam and methadone, but then abruptly declined 3 weeks after the initial event. Magnetic resnance revealed confluent white matter hyperintensity on fluid-attenuated inversion recovery and T2 weighted sequences, and spectroscopy revealed elevated peaks in choline, creatinine, and lactate. Analysis and review of the literature suggests this phenomenon occurs on average about 19 days after the initial event. Although the pathophysiology remains obscure, it is noted here that the mean lucid interval coincides approximately with the replacement half-life for myelin related lipids and proteins.
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49
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Abstract
Great effort has been dedicated to mapping the functional architecture of the brain in health and disease. The neural centers that support cognition and behavior are the "hubs" defining the salient geographic landmarks of the cerebral topography. Similar to urban cartography, however, the functionality of these hubs is critically dependent on the infrastructure permitting the transfer of relevant information from site to site, and this infrastructure is susceptible to deterioration. The groundwork of the brain lies in the form of the complexly organized myelinated nerve fibers responsible for the inter-regional transmission of electrical impulses among distinct neural areas. Damage to the myelin sheath and reduction in the total number of nerve fibers with aging are thought to result in a degradation in the efficiency of communication among neural regions and to contribute to the decline of function in older adults. This article describes selected studies that are relevant to understanding the deterioration in structural connectivity of the aging brain with a focus on potential consequences to functional network activity. First, the neural substrates of connectivity and techniques used in the study of connectivity are described with a focus on neuroimaging methodologies. This is followed with discussion of the negative effects of age on connective integrity, and the possible mechanisms and neural and cognitive consequences of this progressive disconnection. Given the potential for natural repair of certain elements of the connective network, understanding the basis of age-associated decline in connectivity could have important implications with regard to the amelioration of neural dysfunction and the restoration of the infrastructure necessary for optimal function in older adults.
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Affiliation(s)
- David H Salat
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.
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50
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Kohama SG, Rosene DL, Sherman LS. Age-related changes in human and non-human primate white matter: from myelination disturbances to cognitive decline. AGE (DORDRECHT, NETHERLANDS) 2012; 34:1093-110. [PMID: 22203458 PMCID: PMC3448998 DOI: 10.1007/s11357-011-9357-7] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Accepted: 12/01/2011] [Indexed: 05/04/2023]
Abstract
The cognitive decline associated with normal aging was long believed to be due primarily to decreased synaptic density and neuron loss. Recent studies in both humans and non-human primates have challenged this idea, pointing instead to disturbances in white matter (WM) including myelin damage. Here, we review both cross-sectional and longitudinal studies in humans and non-human primates that collectively support the hypothesis that WM disturbances increase with age starting at middle age in humans, that these disturbances contribute to age-related cognitive decline, and that age-related WM changes may occur as a result of free radical damage, degenerative changes in cells in the oligodendrocyte lineage, and changes in microenvironments within WM.
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Affiliation(s)
- Steven G. Kohama
- Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR USA
| | | | - Larry S. Sherman
- Oregon National Primate Research Center, Oregon Health and Science University, Portland, OR USA
- Division of Neuroscience, Oregon National Primate Research Center, 505 NW 185th Ave, Beaverton, OR 97006 USA
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