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Burtscher J, Motl RW, Berek K, Ehrenreich H, Kopp M, Hohenauer E. Hypoxia in multiple sclerosis. Redox Biol 2025; 83:103666. [PMID: 40347693 DOI: 10.1016/j.redox.2025.103666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2025] [Revised: 05/05/2025] [Accepted: 05/05/2025] [Indexed: 05/14/2025] Open
Abstract
Low oxygen availability (hypoxia) is a prominent but poorly understood feature in multiple sclerosis (MS). Whether hypoxia causes or drives MS pathology and symptoms or whether it is a consequence of other pathological events, such as inflammation and vascular dysfunction, is unknown. Here, we summarize the available literature on the interplay between hypoxia and both pathological and symptomatic features of MS. Severe environmental hypoxia (i.e., altitude) may trigger or facilitate MS-related events, possibly by exacerbating tissue hypoxia in the central nervous system. Accordingly, increasing oxygen supply can mitigate pathological and clinical parameters in MS models. In contrast, stimulating the endogenous hypoxia response and adaptation systems by controlled exposure to hypoxia (hypoxia conditioning) renders the central nervous system more resistant to hypoxic insults, thereby attenuating pathology and symptomatology in MS models. Overlapping mechanisms likely play a role in the benefits conferred by physical activity in MS. We provide an integrative model to explain the paradoxically beneficial outcomes of both increased and decreased ambient oxygen conditions. In conclusion, controlled exposure to hypoxia, perhaps in combination with exercise, is a promising, possibly disease-course modifying therapeutic approach for MS. However, many open questions remain.
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Affiliation(s)
- Johannes Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria.
| | - Robert W Motl
- Department of Kinesiology and Nutrition, University of Illinois Chicago, Chicago, IL, USA
| | - Klaus Berek
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Hannelore Ehrenreich
- Experimental Medicine, Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, J 5, Mannheim, Germany
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Erich Hohenauer
- Rehabilitation and Exercise Science Laboratory, Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland; Department of Neurosciences and Movement Science, University of Fribourg, Fribourg, Switzerland
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2
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Pegoretti V, Boerema A, Kats K, Dafauce Garcia JM, Fischer R, Kontermann RE, Pfizenmaier K, Laman JD, Eisel ULM, Baron W. Single intracerebroventricular TNFR2 agonist injection impacts remyelination in the cuprizone model. J Mol Med (Berl) 2025:10.1007/s00109-025-02549-6. [PMID: 40347238 DOI: 10.1007/s00109-025-02549-6] [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: 10/28/2024] [Revised: 04/06/2025] [Accepted: 04/22/2025] [Indexed: 05/12/2025]
Abstract
The development of therapeutics that enhances the regeneration of myelin sheaths following demyelination is predicted to prevent neurodegeneration. A promising target to enhance remyelination is the immunomodulatory cytokine tumor necrosis factor alpha (TNFα) and its receptors TNFR1 and TNFR2. TNFR2 on oligodendrocyte lineage cells and microglia coordinates different protective functions, such as proliferation of oligodendrocyte progenitor cells, survival of mature oligodendrocytes, and release of anti-inflammatory cytokines, in animal models of inflammation and demyelination. Here, we find in the cuprizone model that following demyelination, fewer axons are unmyelinated in the corpus callosum at an early stage of remyelination after single TNFR2 agonist delivery in the lateral ventricle, while astrocyte and microglia number and coverage are unchanged. Towards later stages of remyelination, TNFR2 agonist treatment maintains the number of oligodendrocyte lineage cells, and large caliber axons have thinner myelin. Hence, even short-term stimulation of TNFR2 has a positive impact on the remyelination processes. This study informs further on the beneficial implications of TNFR2 signaling on oligodendrocyte lineage cells and remyelination, emphasizing its potential therapeutic value for demyelinating diseases, including multiple sclerosis. KEY MESSAGES: Single TNFR2 agonist treatment in the lateral ventricle following cuprizone-induced demyelination impacts remyelination by: Leading to a lower percentage of unmyelinated axons at early stages. Preserving the number of oligodendrocyte lineage cells in the corpus callosum at later stages. Covering large calibre axons with thinner myelin sheaths at later stages.
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Affiliation(s)
- Valentina Pegoretti
- Department of Molecular Neurobiology, Groningen, Institute of Evolutionary Life Science (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Ate Boerema
- Department of Molecular Neurobiology, Groningen, Institute of Evolutionary Life Science (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Kim Kats
- Department Biomedical Sciences, Section Molecular Cell Biology, University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - Juan M Dafauce Garcia
- Department of Molecular Neurobiology, Groningen, Institute of Evolutionary Life Science (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Roman Fischer
- Institute of Cell Biology and Immunology, University of Stuttgart, Germany; Stuttgart Research Centre Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Roland E Kontermann
- Institute of Cell Biology and Immunology, University of Stuttgart, Germany; Stuttgart Research Centre Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Klaus Pfizenmaier
- Institute of Cell Biology and Immunology, University of Stuttgart, Germany; Stuttgart Research Centre Systems Biology, University of Stuttgart, Stuttgart, Germany
| | - Jon D Laman
- Department Pathology and Medical Biology, University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - Ulrich L M Eisel
- Department of Molecular Neurobiology, Groningen, Institute of Evolutionary Life Science (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Wia Baron
- Department Biomedical Sciences, Section Molecular Neurobiology, University of Groningen, University Medical Center Groningen (UMCG), MS Center Noord Nederland (MSCNN), A. Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
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3
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Laurent M, Harb R, Jenny C, Oustelandt J, Jimenez S, Cosette J, Landini F, Ferrante A, Corre G, Vujic N, Piccoli C, Brassier A, Van Wittenberghe L, Ronzitti G, Kratky D, Pacelli C, Amendola M. Rescue of lysosomal acid lipase deficiency in mice by rAAV8 liver gene transfer. COMMUNICATIONS MEDICINE 2025; 5:110. [PMID: 40216942 PMCID: PMC11992068 DOI: 10.1038/s43856-025-00816-8] [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: 06/06/2024] [Accepted: 03/20/2025] [Indexed: 04/14/2025] Open
Abstract
BACKGROUND Lysosomal acid lipase deficiency (LAL-D) is an autosomal recessive disorder caused by mutations in the LIPA gene, which results in lipid accumulation leading to multi-organ failure. If left untreated, the severe form of LAL-D results in premature death within the first year of life due to failure to thrive and hepatic insufficiency. Weekly systemic injections of recombinant LAL protein, referred as enzyme replacement therapy, is the only available supportive treatment. METHOD Here, we characterized a novel Lipa-/- mouse model and developed a curative gene therapy treatment based on the in vivo administration of recombinant (r)AAV8 vector encoding the human LIPA transgene under the control of a hepatocyte-specific promoter. RESULTS Here we define the minimal rAAV8 dose required to rescue disease lethality and to correct cholesterol and triglyceride accumulation in multiple organs and blood. Finally, using liver transcriptomic and biochemical analysis, we show mitochondrial impairment in Lipa-/- mice and its recovery by gene therapy. CONCLUSIONS Overall, our in vivo gene therapy strategy achieves a stable long-term LAL expression sufficient to correct the disease phenotype in the Lipa-/- mouse model and offers a new therapeutic option for LAL-D patients.
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Affiliation(s)
- Marine Laurent
- Genethon, 91000, Evry, France
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Rim Harb
- Genethon, 91000, Evry, France
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Christine Jenny
- Genethon, 91000, Evry, France
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Julie Oustelandt
- Genethon, 91000, Evry, France
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | | | | | - Francesca Landini
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Aristide Ferrante
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Guillaume Corre
- Genethon, 91000, Evry, France
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Nemanja Vujic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medicine University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Claudia Piccoli
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Anais Brassier
- Necker-Enfants-Malades University Hospital, Paris, France
| | | | - Giuseppe Ronzitti
- Genethon, 91000, Evry, France
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France
| | - Dagmar Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medicine University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Consiglia Pacelli
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy
| | - Mario Amendola
- Genethon, 91000, Evry, France.
- Paris-Saclay University, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, 91000, Evry, France.
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
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Huang S, Dong W, Lin X, Bian J. Na+/K+-ATPase: ion pump, signal transducer, or cytoprotective protein, and novel biological functions. Neural Regen Res 2024; 19:2684-2697. [PMID: 38595287 PMCID: PMC11168508 DOI: 10.4103/nrr.nrr-d-23-01175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/23/2023] [Accepted: 12/09/2023] [Indexed: 04/11/2024] Open
Abstract
Na+/K+-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na+ out of and two K+ into cells. Additionally, Na+/K+-ATPase participates in Ca2+-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane. Na+/K+-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells. Therefore, it is not surprising that Na+/K+-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases. However, published studies have so far only elucidated the important roles of Na+/K+-ATPase dysfunction in disease development, and we are lacking detailed mechanisms to clarify how Na+/K+-ATPase affects cell function. Our recent studies revealed that membrane loss of Na+/K+-ATPase is a key mechanism in many neurological disorders, particularly stroke and Parkinson's disease. Stabilization of plasma membrane Na+/K+-ATPase with an antibody is a novel strategy to treat these diseases. For this reason, Na+/K+-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein, participating in signal transduction such as neuronal autophagy and apoptosis, and glial cell migration. Thus, the present review attempts to summarize the novel biological functions of Na+/K+-ATPase and Na+/K+-ATPase-related pathogenesis. The potential for novel strategies to treat Na+/K+-ATPase-related brain diseases will also be discussed.
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Affiliation(s)
- Songqiang Huang
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Wanting Dong
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Xiaoqian Lin
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
| | - Jinsong Bian
- Department of Pharmacology, Joint Laboratory of Guangdong-Hong Kong Universities for Vascular Homeostasis and Diseases, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China
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5
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Nheu D, Petratos S. How does Nogo-A signalling influence mitochondrial function during multiple sclerosis pathogenesis? Neurosci Biobehav Rev 2024; 163:105767. [PMID: 38885889 DOI: 10.1016/j.neubiorev.2024.105767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/30/2024] [Accepted: 06/08/2024] [Indexed: 06/20/2024]
Abstract
Multiple sclerosis (MS) is a severe neurological disorder that involves inflammation in the brain, spinal cord and optic nerve with key disabling neuropathological outcomes being axonal damage and demyelination. When degeneration of the axo-glial union occurs, a consequence of inflammatory damage to central nervous system (CNS) myelin, dystrophy and death can lead to large membranous structures from dead oligodendrocytes and degenerative myelin deposited in the extracellular milieu. For the first time, this review covers mitochondrial mechanisms that may be operative during MS-related neurodegenerative changes directly activated during accumulating extracellular deposits of myelin associated inhibitory factors (MAIFs), that include the potent inhibitor of neurite outgrowth, Nogo-A. Axonal damage may occur when Nogo-A binds to and signals through its cognate receptor, NgR1, a multimeric complex, to initially stall axonal transport and limit the delivery of important growth-dependent cargo and subcellular organelles such as mitochondria for metabolic efficiency at sites of axo-glial disintegration as a consequence of inflammation. Metabolic efficiency in axons fails during active demyelination and progressive neurodegeneration, preceded by stalled transport of functional mitochondria to fuel axo-glial integrity.
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Affiliation(s)
- Danica Nheu
- Department of Neuroscience, School of Translational Medicine, Monash University, Prahran, VIC 3004, Australia
| | - Steven Petratos
- Department of Neuroscience, School of Translational Medicine, Monash University, Prahran, VIC 3004, Australia.
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6
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Gisevius B, Duscha A, Poschmann G, Stühler K, Motte J, Fisse AL, Augustyniak S, Rehm A, Renk P, Böse C, Hubert D, Peters K, Jagst M, Gömer A, Todt D, Bader V, Tokic M, Hirschberg S, Krogias C, Trampe N, Coutourier C, Winnesberg C, Steinmann E, Winklhofer K, Gold R, Haghikia A. Propionic acid promotes neurite recovery in damaged multiple sclerosis neurons. Brain Commun 2024; 6:fcae182. [PMID: 38894951 PMCID: PMC11184351 DOI: 10.1093/braincomms/fcae182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 03/21/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
Neurodegeneration in the autoimmune disease multiple sclerosis still poses a major therapeutic challenge. Effective drugs that target the inflammation can only partially reduce accumulation of neurological deficits and conversion to progressive disease forms. Diet and the associated gut microbiome are currently being discussed as crucial environmental risk factors that determine disease onset and subsequent progression. In people with multiple sclerosis, supplementation of the short-chain fatty acid propionic acid, as a microbial metabolite derived from the fermentation of a high-fiber diet, has previously been shown to regulate inflammation accompanied by neuroprotective properties. We set out to determine whether the neuroprotective impact of propionic acid is a direct mode of action of short-chain fatty acids on CNS neurons. We analysed neurite recovery in the presence of the short-chain fatty acid propionic acid and butyric acid in a reverse-translational disease-in-a-dish model of human-induced primary neurons differentiated from people with multiple sclerosis-derived induced pluripotent stem cells. We found that recovery of damaged neurites is induced by propionic acid and butyric acid. We could also show that administration of butyric acid is able to enhance propionic acid-associated neurite recovery. Whole-cell proteome analysis of induced primary neurons following recovery in the presence of propionic acid revealed abundant changes of protein groups that are associated with the chromatin assembly, translational, and metabolic processes. We further present evidence that these alterations in the chromatin assembly were associated with inhibition of histone deacetylase class I/II following both propionic acid and butyric acid treatment, mediated by free fatty acid receptor signalling. While neurite recovery in the presence of propionic acid is promoted by activation of the anti-oxidative response, administration of butyric acid increases neuronal ATP synthesis in people with multiple sclerosis-specific induced primary neurons.
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Affiliation(s)
- Barbara Gisevius
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Alexander Duscha
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
- Department of Neurology, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Gereon Poschmann
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
- Molecular Proteomics Laboratory, BMFZ, Heinrich Heine University Düsseldorf, 40335 Düsseldorf, Germany
| | - Kai Stühler
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
- Molecular Proteomics Laboratory, BMFZ, Heinrich Heine University Düsseldorf, 40335 Düsseldorf, Germany
| | - Jeremias Motte
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Anna Lena Fisse
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Sanja Augustyniak
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Adriana Rehm
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Pia Renk
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Celina Böse
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Diana Hubert
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Kathrin Peters
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Michelle Jagst
- Department for Molecular and Medical Virology, Ruhr-University Bochum, 44801 Bochum, Germany
- Institute of Virology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - André Gömer
- Department for Molecular and Medical Virology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Daniel Todt
- Department for Molecular and Medical Virology, Ruhr-University Bochum, 44801 Bochum, Germany
- European Virus Bioinformatics Center (EVBC), 07743 Jena, Germany
| | - Verian Bader
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Marianne Tokic
- Department of Medical Informatics, Biometry and Epidemiology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Sarah Hirschberg
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Christos Krogias
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Nadine Trampe
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Charlotta Coutourier
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Carmen Winnesberg
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Eike Steinmann
- Department for Molecular and Medical Virology, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Konstanze Winklhofer
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr-University Bochum, 44801 Bochum, Germany
- Cluster of Excellence RESOLV, 44801 Bochum, Germany
| | - Ralf Gold
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
| | - Aiden Haghikia
- Department of Neurology, St. Josef Hospital, Ruhr-University Bochum, 44791 Bochum, Germany
- Department of Neurology, Otto-von-Guericke University, 39120 Magdeburg, Germany
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Kipp M. How to Use the Cuprizone Model to Study De- and Remyelination. Int J Mol Sci 2024; 25:1445. [PMID: 38338724 PMCID: PMC10855335 DOI: 10.3390/ijms25031445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 01/19/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Multiple sclerosis (MS) is an autoimmune and inflammatory disorder affecting the central nervous system whose cause is still largely unknown. Oligodendrocyte degeneration results in demyelination of axons, which can eventually be repaired by a mechanism called remyelination. Prevention of demyelination and the pharmacological support of remyelination are two promising strategies to ameliorate disease progression in MS patients. The cuprizone model is commonly employed to investigate oligodendrocyte degeneration mechanisms or to explore remyelination pathways. During the last decades, several different protocols have been applied, and all have their pros and cons. This article intends to offer guidance for conducting pre-clinical trials using the cuprizone model in mice, focusing on discovering new treatment approaches to prevent oligodendrocyte degeneration or enhance remyelination.
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Affiliation(s)
- Markus Kipp
- Rostock University Medical Center, Institute of Anatomy, 18057 Rostock, Germany
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8
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Smith G, Sweeney ST, O’Kane CJ, Prokop A. How neurons maintain their axons long-term: an integrated view of axon biology and pathology. Front Neurosci 2023; 17:1236815. [PMID: 37564364 PMCID: PMC10410161 DOI: 10.3389/fnins.2023.1236815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Axons are processes of neurons, up to a metre long, that form the essential biological cables wiring nervous systems. They must survive, often far away from their cell bodies and up to a century in humans. This requires self-sufficient cell biology including structural proteins, organelles, and membrane trafficking, metabolic, signalling, translational, chaperone, and degradation machinery-all maintaining the homeostasis of energy, lipids, proteins, and signalling networks including reactive oxygen species and calcium. Axon maintenance also involves specialised cytoskeleton including the cortical actin-spectrin corset, and bundles of microtubules that provide the highways for motor-driven transport of components and organelles for virtually all the above-mentioned processes. Here, we aim to provide a conceptual overview of key aspects of axon biology and physiology, and the homeostatic networks they form. This homeostasis can be derailed, causing axonopathies through processes of ageing, trauma, poisoning, inflammation or genetic mutations. To illustrate which malfunctions of organelles or cell biological processes can lead to axonopathies, we focus on axonopathy-linked subcellular defects caused by genetic mutations. Based on these descriptions and backed up by our comprehensive data mining of genes linked to neural disorders, we describe the 'dependency cycle of local axon homeostasis' as an integrative model to explain why very different causes can trigger very similar axonopathies, providing new ideas that can drive the quest for strategies able to battle these devastating diseases.
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Affiliation(s)
- Gaynor Smith
- Cardiff University, School of Medicine, College of Biomedical and Life Sciences, Cardiff, United Kingdom
| | - Sean T. Sweeney
- Department of Biology, University of York and York Biomedical Research Institute, York, United Kingdom
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, The University of Manchester, Manchester, United Kingdom
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9
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Kole K, Voesenek BJB, Brinia ME, Petersen N, Kole MHP. Parvalbumin basket cell myelination accumulates axonal mitochondria to internodes. Nat Commun 2022; 13:7598. [PMID: 36494349 PMCID: PMC9734141 DOI: 10.1038/s41467-022-35350-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 11/30/2022] [Indexed: 12/13/2022] Open
Abstract
Parvalbumin-expressing (PV+) basket cells are fast-spiking inhibitory interneurons that exert critical control over local circuit activity and oscillations. PV+ axons are often myelinated, but the electrical and metabolic roles of interneuron myelination remain poorly understood. Here, we developed viral constructs allowing cell type-specific investigation of mitochondria with genetically encoded fluorescent probes. Single-cell reconstructions revealed that mitochondria selectively cluster to myelinated segments of PV+ basket cells, confirmed by analyses of a high-resolution electron microscopy dataset. In contrast to the increased mitochondrial densities in excitatory axons cuprizone-induced demyelination abolished mitochondrial clustering in PV+ axons. Furthermore, with genetic deletion of myelin basic protein the mitochondrial clustering was still observed at internodes wrapped by noncompacted myelin, indicating that compaction is dispensable. Finally, two-photon imaging of action potential-evoked calcium (Ca2+) responses showed that interneuron myelination attenuates both the cytosolic and mitochondrial Ca2+ transients. These findings suggest that oligodendrocyte ensheathment of PV+ axons assembles mitochondria to branch selectively fine-tune metabolic demands.
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Affiliation(s)
- Koen Kole
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Bas J. B. Voesenek
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Maria E. Brinia
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands ,grid.5216.00000 0001 2155 0800Medical School, National Kapodistrian University of Athens, Athens, 11527 Greece
| | - Naomi Petersen
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands
| | - Maarten H. P. Kole
- grid.418101.d0000 0001 2153 6865Axonal Signaling Group, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, 1105 BA Amsterdam, the Netherlands ,grid.5477.10000000120346234Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
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