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Lyman KA, Han Y, Robinson AP, Weinberg SE, Fisher DW, Heuermann RJ, Lyman RE, Kim DK, Ludwig A, Chandel NS, Does MD, Miller SD, Chetkovich DM. Characterization of hyperpolarization-activated cyclic nucleotide-gated channels in oligodendrocytes. Front Cell Neurosci 2024; 18:1321682. [PMID: 38469353 PMCID: PMC10925711 DOI: 10.3389/fncel.2024.1321682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Accepted: 02/08/2024] [Indexed: 03/13/2024] Open
Abstract
Mature oligodendrocytes (OLG) are the myelin-forming cells of the central nervous system. Recent work has shown a dynamic role for these cells in the plasticity of neural circuits, leading to a renewed interest in voltage-sensitive currents in OLG. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and their respective current (Ih) were recently identified in mature OLG and shown to play a role in regulating myelin length. Here we provide a biochemical and electrophysiological characterization of HCN channels in cells of the oligodendrocyte lineage. We observed that mice with a nonsense mutation in the Hcn2 gene (Hcn2ap/ap) have less white matter than their wild type counterparts with fewer OLG and fewer oligodendrocyte progenitor cells (OPCs). Hcn2ap/ap mice have severe motor impairments, although these deficits were not observed in mice with HCN2 conditionally eliminated only in oligodendrocytes (Cnpcre/+; Hcn2F/F). However, Cnpcre/+; Hcn2F/F mice develop motor impairments more rapidly in response to experimental autoimmune encephalomyelitis (EAE). We conclude that HCN2 channels in OLG may play a role in regulating metabolism.
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Affiliation(s)
- Kyle A. Lyman
- Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
| | - Ye Han
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Andrew P. Robinson
- Department of Microbiology-Immunology and Interdepartmental Immunobiology Center, Northwestern University, Chicago, IL, United States
| | - Samuel E. Weinberg
- Department of Medicine, Northwestern University, Chicago, IL, United States
| | - Daniel W. Fisher
- Department of Psychiatry, University of Washington, Seattle, WA, United States
| | - Robert J. Heuermann
- Department of Neurology, Washington University, St. Louis, MO, United States
| | - Reagan E. Lyman
- Heritage College of Osteopathic Medicine, Ohio University, Dublin, OH, United States
| | - Dong Kyu Kim
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States
- Department of Electrical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Andreas Ludwig
- Institut fur Experimentelle und Klinische Pharmakologie und Toxikologie, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Germany
| | - Navdeep S. Chandel
- Department of Medicine, Northwestern University, Chicago, IL, United States
| | - Mark D. Does
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States
- Department of Electrical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Stephen D. Miller
- Department of Microbiology-Immunology and Interdepartmental Immunobiology Center, Northwestern University, Chicago, IL, United States
| | - Dane M. Chetkovich
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
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Cho CH, Deyneko IV, Cordova-Martinez D, Vazquez J, Maguire AS, Diaz JR, Carbonell AU, Tindi JO, Cui MH, Fleysher R, Molholm S, Lipton ML, Branch CA, Hodgson L, Jordan BA. ANKS1B encoded AIDA-1 regulates social behaviors by controlling oligodendrocyte function. Nat Commun 2023; 14:8499. [PMID: 38129387 PMCID: PMC10739966 DOI: 10.1038/s41467-023-43438-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 11/09/2023] [Indexed: 12/23/2023] Open
Abstract
Heterozygous deletions in the ANKS1B gene cause ANKS1B neurodevelopmental syndrome (ANDS), a rare genetic disease characterized by autism spectrum disorder (ASD), attention deficit/hyperactivity disorder, and speech and motor deficits. The ANKS1B gene encodes for AIDA-1, a protein that is enriched at neuronal synapses and regulates synaptic plasticity. Here we report an unexpected role for oligodendroglial deficits in ANDS pathophysiology. We show that Anks1b-deficient mouse models display deficits in oligodendrocyte maturation, myelination, and Rac1 function, and recapitulate white matter abnormalities observed in ANDS patients. Selective loss of Anks1b from the oligodendrocyte lineage, but not from neuronal populations, leads to deficits in social preference and sensory reactivity previously observed in a brain-wide Anks1b haploinsufficiency model. Furthermore, we find that clemastine, an antihistamine shown to increase oligodendrocyte precursor cell maturation and central nervous system myelination, rescues deficits in social preference in 7-month-old Anks1b-deficient mice. Our work shows that deficits in social behaviors present in ANDS may originate from abnormal Rac1 activity within oligodendrocytes.
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Affiliation(s)
- Chang Hoon Cho
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Human Pathobiology and OMNI Reverse Translation, Genentech, Inc., San Francisco, CA, USA
| | - Ilana Vasilisa Deyneko
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Dylann Cordova-Martinez
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Juan Vazquez
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Anne S Maguire
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jenny R Diaz
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Abigail U Carbonell
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jaafar O Tindi
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Min-Hui Cui
- Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Roman Fleysher
- Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Sophie Molholm
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Michael L Lipton
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Craig A Branch
- Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss Magnetic Resonance Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Louis Hodgson
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
- Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Bryen A Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA.
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA.
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3
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Nemati S, Kondiles BR, Wheeler S. The Contributions of the mTOR Complexes: How Does Regional and Temporal Heterogeneity Affect Myelination and Remyelination? J Neurosci 2023; 43:5590-5592. [PMID: 37532457 PMCID: PMC10401627 DOI: 10.1523/jneurosci.0545-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 08/04/2023] Open
Affiliation(s)
- Saina Nemati
- Undergraduate Student in the Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Bethany R Kondiles
- Postdoctoral Research Fellow in the Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Sarah Wheeler
- Graduate Student in the Department of Cell and Developmental Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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4
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de la Monte SM, Tong M, Delikkaya B. Differential Early Mechanistic Frontal Lobe Responses to Choline Chloride and Soy Isoflavones in an Experimental Model of Fetal Alcohol Spectrum Disorder. Int J Mol Sci 2023; 24:ijms24087595. [PMID: 37108779 PMCID: PMC10145811 DOI: 10.3390/ijms24087595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/07/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
Fetal alcohol spectrum disorder (FASD) is the most common preventable cause of neurodevelopmental defects, and white matter is a major target of ethanol neurotoxicity. Therapeutic interventions with choline or dietary soy could potentially supplement public health preventive measures. However, since soy contains abundant choline, it would be important to know if its benefits are mediated by choline or isoflavones. We compared early mechanistic responses to choline and the Daidzein+Genistein (D+G) soy isoflavones in an FASD model using frontal lobe tissue to assess oligodendrocyte function and Akt-mTOR signaling. Long Evans rat pups were binge administered 2 g/Kg of ethanol or saline (control) on postnatal days P3 and P5. P7 frontal lobe slice cultures were treated with vehicle (Veh), Choline chloride (Chol; 75 µM), or D+G (1 µM each) for 72 h without further ethanol exposures. The expression levels of myelin oligodendrocyte proteins and stress-related molecules were measured by duplex enzyme-linked immunosorbent assays (ELISAs), and mTOR signaling proteins and phosphoproteins were assessed using 11-plex magnetic bead-based ELISAs. Ethanol's main short-term effects in Veh-treated cultures were to increase GFAP and relative PTEN phosphorylation and reduce Akt phosphorylation. Chol and D+G significantly modulated the expression of oligodendrocyte myelin proteins and mediators of insulin/IGF-1-Akt-mTOR signaling in both control and ethanol-exposed cultures. In general, the responses were more robust with D+G; the main exception was that RPS6 phosphorylation was significantly increased by Chol and not D+G. The findings suggest that dietary soy, with the benefits of providing complete nutrition together with Choline, could be used to help optimize neurodevelopment in humans at risk for FASD.
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Affiliation(s)
- Suzanne M de la Monte
- Departments of Pathology and Laboratory Medicine, Medicine, Neurology and Neurosurgery, Rhode Island Hospital, Lifespan Academic Institutions, The Warren Alpert Medical School of Brown University, Providence, RI 02903, USA
| | - Ming Tong
- Departments of Pathology and Laboratory Medicine, Medicine, Neurology and Neurosurgery, Rhode Island Hospital, Lifespan Academic Institutions, The Warren Alpert Medical School of Brown University, Providence, RI 02903, USA
| | - Busra Delikkaya
- Departments of Pathology and Laboratory Medicine, Medicine, Neurology and Neurosurgery, Rhode Island Hospital, Lifespan Academic Institutions, The Warren Alpert Medical School of Brown University, Providence, RI 02903, USA
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5
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Dahl KD, Almeida AR, Hathaway HA, Bourne J, Brown TL, Finseth LT, Wood TL, Macklin WB. mTORC2 Loss in Oligodendrocyte Progenitor Cells Results in Regional Hypomyelination in the Central Nervous System. J Neurosci 2023; 43:540-58. [PMID: 36460463 DOI: 10.1523/JNEUROSCI.0010-22.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 11/02/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
In the CNS, oligodendrocyte progenitor cells (OPCs) differentiate into mature oligodendrocytes to generate myelin, an essential component for normal nervous system function. OPC differentiation is driven by signaling pathways, such as mTOR, which functions in two distinct complexes: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), containing Raptor or Rictor, respectively. In the current studies, mTORC2 signaling was selectively deleted from OPCs in PDGFRα-Cre X Rictorfl/fl mice. This study examined developmental myelination in male and female mice, comparing the impact of mTORC2 deletion in the corpus callosum and spinal cord. In both regions, Rictor loss in OPCs resulted in early reduction in myelin RNAs and proteins. However, these deficits rapidly recovered in spinal cord, where normal myelin was noted at P21 and P45. By contrast, the losses in corpus callosum resulted in severe hypomyelination and increased unmyelinated axons. The hypomyelination may result from decreased oligodendrocytes in the corpus callosum, which persisted in animals as old as postnatal day 350. The current studies focus on uniquely altered signaling pathways following mTORC2 loss in developing oligodendrocytes. A major mTORC2 substrate is phospho-Akt-S473, which was significantly reduced throughout development in both corpus callosum and spinal cord at all ages measured, yet this had little impact in spinal cord. Loss of mTORC2 signaling resulted in decreased expression of actin regulators, such as gelsolin in corpus callosum, but only minimal loss in spinal cord. The current study establishes a regionally specific role for mTORC2 signaling in OPCs, particularly in the corpus callosum.SIGNIFICANCE STATEMENT mTORC1 and mTORC2 signaling has differential impact on myelination in the CNS. Numerous studies identify a role for mTORC1, but deletion of Rictor (mTORC2 signaling) in late-stage oligodendrocytes had little impact on myelination in the CNS. However, the current studies establish that deletion of mTORC2 signaling from oligodendrocyte progenitor cells results in reduced myelination of brain axons. These studies also establish a regional impact of mTORC2, with little change in spinal cord in these conditional Rictor deletion mice. Importantly, in both brain and spinal cord, mTORC2 downstream signaling targets were impacted by Rictor deletion. Yet, these signaling changes had little impact on myelination in spinal cord, while they resulted in long-term alterations in myelination in brain.
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6
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Wang Y, Xiong Z, Zhou C, Zhang Q, Liu S, Dong S, Jiang X, Yu W. AKBA Promotes Axonal Regeneration via RhoA/Rictor to Repair Damaged Sciatic Nerve. Int J Mol Sci 2022; 23. [PMID: 36555556 DOI: 10.3390/ijms232415903] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/22/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
The existing studies by our team demonstrated the pro-recovery effect of 3-Acetyl-11-keto-beta-boswellic acid (AKBA) on a sciatic nerve injury. To further investigate the role of AKBA in peripheral nerve injury repair, The TMT quantitative proteomics technique was used to obtain differentially significant proteins in a Sham group, Model group, and AKBA group. After that, three time points (5, 14, and 28 d) and four groups (Sham + AKBA, Sham, Model, and AKBA) were set up, and immunoblotting, immunofluorescence, and cellular assays were applied to investigate the expression of CDC42, Rac1, RhoA, and Rictor in the sciatic nerve at different time points for each group in more depth. The results showed that AKBA enriched the cellular components of the myelin sheath and axon regeneration after a sciatic nerve injury and that AKBA upregulated CDC42 and Rac1 and downregulated RhoA expression 5 d after a sciatic nerve injury, promoting axon regeneration and improving the repair of a sciatic nerve injury in rats. Rictor is regulated by AKBA and upregulated in PC12 cells after AKBA action. Our findings provide a new basis for AKBA treatment of a peripheral nerve injury.
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7
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Pandey S, Shen K, Lee SH, Shen YAA, Wang Y, Otero-García M, Kotova N, Vito ST, Laufer BI, Newton DF, Rezzonico MG, Hanson JE, Kaminker JS, Bohlen CJ, Yuen TJ, Friedman BA. Disease-associated oligodendrocyte responses across neurodegenerative diseases. Cell Rep 2022; 40:111189. [PMID: 36001972 DOI: 10.1016/j.celrep.2022.111189] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 05/17/2022] [Accepted: 07/20/2022] [Indexed: 12/29/2022] Open
Abstract
Oligodendrocyte dysfunction has been implicated in the pathogenesis of neurodegenerative diseases, so understanding oligodendrocyte activation states would shed light on disease processes. We identify three distinct activation states of oligodendrocytes from single-cell RNA sequencing (RNA-seq) of mouse models of Alzheimer's disease (AD) and multiple sclerosis (MS): DA1 (disease-associated1, associated with immunogenic genes), DA2 (disease-associated2, associated with genes influencing survival), and IFN (associated with interferon response genes). Spatial analysis of disease-associated oligodendrocytes (DAOs) in the cuprizone model reveals that DA1 and DA2 are established outside of the lesion area during demyelination and that DA1 repopulates the lesion during remyelination. Independent meta-analysis of human single-nucleus RNA-seq datasets reveals that the transcriptional responses of MS oligodendrocytes share features with mouse models. In contrast, the oligodendrocyte activation signature observed in human AD is largely distinct from those observed in mice. This catalog of oligodendrocyte activation states (http://research-pub.gene.com/OligoLandscape/) will be important to understand disease progression and develop therapeutic interventions.
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Affiliation(s)
- Shristi Pandey
- Department of OMNI Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Kimberle Shen
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Seung-Hye Lee
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Yun-An A Shen
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Yuanyuan Wang
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | | | | | - Stephen T Vito
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Benjamin I Laufer
- Department of OMNI Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Dwight F Newton
- Department of OMNI Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA; Roche Global IT Solution Centre, Hoffman-La Roche Canada, 7070 Mississauga Road, Mississauga, ON, Canada
| | - Mitchell G Rezzonico
- Department of OMNI Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Jesse E Hanson
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Joshua S Kaminker
- Department of OMNI Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Christopher J Bohlen
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Tracy J Yuen
- Department of Neuroscience, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Brad A Friedman
- Department of OMNI Bioinformatics, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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Jeffries MA, McLane LE, Khandker L, Mather ML, Evangelou AV, Kantak D, Bourne JN, Macklin WB, Wood TL. mTOR Signaling Regulates Metabolic Function in Oligodendrocyte Precursor Cells and Promotes Efficient Brain Remyelination in the Cuprizone Model. J Neurosci 2021; 41:8321-8337. [PMID: 34417330 PMCID: PMC8496195 DOI: 10.1523/jneurosci.1377-20.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/21/2021] [Accepted: 08/10/2021] [Indexed: 02/02/2023] Open
Abstract
In demyelinating diseases, such as multiple sclerosis, primary loss of myelin and subsequent neuronal degeneration throughout the CNS impair patient functionality. While the importance of mechanistic target of rapamycin (mTOR) signaling during developmental myelination is known, no studies have yet directly examined the function of mTOR signaling specifically in the oligodendrocyte (OL) lineage during remyelination. Here, we conditionally deleted Mtor from adult oligodendrocyte precursor cells (OPCs) using Ng2-CreERT in male adult mice to test its function in new OLs responsible for remyelination. During early remyelination after cuprizone-induced demyelination, mice lacking mTOR in adult OPCs had unchanged OL numbers but thinner myelin. Myelin thickness recovered by late-stage repair, suggesting a delay in myelin production when Mtor is deleted from adult OPCs. Surprisingly, loss of mTOR in OPCs had no effect on efficiency of remyelination after lysophosphatidylcholine lesions in either the spinal cord or corpus callosum, suggesting that mTOR signaling functions specifically in a pathway dysregulated by cuprizone to promote remyelination efficiency. We further determined that cuprizone and inhibition of mTOR cooperatively compromise metabolic function in primary rat OLs undergoing differentiation. Together, our results support the conclusion that mTOR signaling in OPCs is required to overcome the metabolic dysfunction in the cuprizone-demyelinated adult brain.SIGNIFICANCE STATEMENT Impaired remyelination by oligodendrocytes contributes to the progressive pathology in multiple sclerosis, so it is critical to identify mechanisms of improving remyelination. The goal of this study was to examine mechanistic target of rapamycin (mTOR) signaling in remyelination. Here, we provide evidence that mTOR signaling promotes efficient remyelination of the brain after cuprizone-mediated demyelination but has no effect on remyelination after lysophosphatidylcholine demyelination in the spinal cord or brain. We also present novel data revealing that mTOR inhibition and cuprizone treatment additively affect the metabolic profile of differentiating oligodendrocytes, supporting a mechanism for the observed remyelination delay. These data suggest that altered metabolic function may underlie failure of remyelination in multiple sclerosis lesions and that mTOR signaling may be of therapeutic potential for promoting remyelination.
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Affiliation(s)
- Marisa A Jeffries
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
| | - Lauren E McLane
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
| | - Luipa Khandker
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
| | - Marie L Mather
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
| | - Angelina V Evangelou
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
| | - Divyangi Kantak
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
| | - Jennifer N Bourne
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Teresa L Wood
- Department of Pharmacology, Physiology, and Neuroscience and Center for Cell Signaling, Rutgers New Jersey Medical School, Newark, New Jersey 07103
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9
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Thamizhoviya G, Vanisree AJ. Enriched Environment Enhances the Myelin Regulatory Factor by mTOR Signaling and Protects the Myelin Membrane Against Oxidative Damage in Rats Exposed to Chronic Immobilization Stress. Neurochem Res 2021; 46:3314-24. [PMID: 34449011 DOI: 10.1007/s11064-021-03433-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 07/31/2021] [Accepted: 08/19/2021] [Indexed: 02/07/2023]
Abstract
Long-term consequences of stress intervene in normal signaling of the brain leading to many psychological complications. The enriched environment (EE) may potentially ameliorate the stress response in rats. However, the mechanistic understanding of the enriched environment in protecting the myelin membrane from oxidative damage after prolonged exposure to immobilization stress (IS) remains vague. In the current study, we examined the impact of EE by exposing the rats to IS (4 h/day) followed by EE treatment (2 h/day) for 28 days and the activities of ROS, lipid peroxides, and phospholipids were studied, and its influence on the myelin regulatory factor (MyRF) and enzymes linked to sphingolipid was assessed in the forebrain region of myelin membrane. The ROS and lipid peroxidation was increased, and a significant decrease in the antioxidant activities was found in the IS group. IS + EE could reduce oxidative damage and increase the levels of antioxidant activities. The individual phospholipids including sphingomyelin (SM), phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE), and phosphatidic acid (PA) were decreased in the IS group, while IS + EE exhibited significant increase in the phospholipid classes regardless of the exposure to IS. There was down-regulation in the mRNA levels of MyRF, CERS2, SPLTC2, UGT8, and GLTP, while IS + EE could mitigate the up-regulation in the levels of mRNA of MyRF, CERS2, SPLTC2, UGT8, and GLTP. The protein expression of MOG, PLP1, and mTOR was found to be reduced in the IS group of rats, however, IS + EE revealed significant increase in the expression of these signaling molecules. These results suggest that EE had a positive effect on chronic stress response by protecting the myelin membrane against oxidative damage and increasing the protein synthesis required for myelin membrane plasticity via activation of MyRF and mTOR signaling in the forebrain region of IS exposed rats.
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10
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Klofas LK, Short BP, Zhou C, Carson RP. Prevention of premature death and seizures in a Depdc5 mouse epilepsy model through inhibition of mTORC1. Hum Mol Genet 2021; 29:1365-1377. [PMID: 32280987 DOI: 10.1093/hmg/ddaa068] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
Mutations in DEP domain containing 5 (DEPDC5) are increasingly appreciated as one of the most common causes of inherited focal epilepsy. Epilepsies due to DEPDC5 mutations are often associated with brain malformations, tend to be drug-resistant, and have been linked to an increased risk of sudden unexplained death in epilepsy (SUDEP). Generation of epilepsy models to define mechanisms of epileptogenesis remains vital for future therapies. Here, we describe a novel mouse model of Depdc5 deficiency with a severe epilepsy phenotype, generated by conditional deletion of Depdc5 in dorsal telencephalic neuroprogenitor cells. In contrast to control and heterozygous mice, Depdc5-Emx1-Cre conditional knockout (CKO) mice demonstrated macrocephaly, spontaneous seizures and premature death. Consistent with increased mTORC1 activation, targeted neurons were enlarged and both neurons and astrocytes demonstrated increased S6 phosphorylation. Electrophysiologic characterization of miniature inhibitory post-synaptic currents in excitatory neurons was consistent with impaired post-synaptic response to GABAergic input, suggesting a potential mechanism for neuronal hyperexcitability. mTORC1 inhibition with rapamycin significantly improved survival of CKO animals and prevented observed seizures, including for up to 40 days following rapamycin withdrawal. These data not only support a primary role for mTORC1 hyperactivation in epilepsy following homozygous loss of Depdc5, but also suggest a developmental window for treatment which may have a durable benefit for some time even after withdrawal.
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Affiliation(s)
- Lindsay K Klofas
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA
| | - Brittany P Short
- Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Robert P Carson
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232, USA.,Division of Pediatric Neurology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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11
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Mühlebner A, van Scheppingen J, de Neef A, Bongaarts A, Zimmer TS, Mills JD, Jansen FE, Spliet WGM, Krsek P, Zamecnik J, Coras R, Blumcke I, Feucht M, Scholl T, Gruber VE, Hainfellner JA, Söylemezoğlu F, Kotulska K, Lagae L, Jansen AC, Kwiatkowski DJ, Jozwiak S, Curatolo P, Aronica E. Myelin Pathology Beyond White Matter in Tuberous Sclerosis Complex (TSC) Cortical Tubers. J Neuropathol Exp Neurol 2021; 79:1054-1064. [PMID: 32954437 PMCID: PMC7559237 DOI: 10.1093/jnen/nlaa090] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Tuberous sclerosis complex (TSC) is a monogenetic disease that arises due to mutations in either the TSC1 or TSC2 gene and affects multiple organ systems. One of the hallmark manifestations of TSC are cortical malformations referred to as cortical tubers. These tubers are frequently associated with treatment-resistant epilepsy. Some of these patients are candidates for epilepsy surgery. White matter abnormalities, such as loss of myelin and oligodendroglia, have been described in a small subset of resected tubers but mechanisms underlying this phenomenon are unclear. Herein, we analyzed a variety of neuropathologic and immunohistochemical features in gray and white matter areas of resected cortical tubers from 46 TSC patients using semi-automated quantitative image analysis. We observed divergent amounts of myelin basic protein as well as numbers of oligodendroglia in both gray and white matter when compared with matched controls. Analyses of clinical data indicated that reduced numbers of oligodendroglia were associated with lower numbers on the intelligence quotient scale and that lower amounts of myelin-associated oligodendrocyte basic protein were associated with the presence of autism-spectrum disorder. In conclusion, myelin pathology in cortical tubers extends beyond the white matter and may be linked to cognitive dysfunction in TSC patients.
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Affiliation(s)
- Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Jackelien van Scheppingen
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Andrew de Neef
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Anika Bongaarts
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Till S Zimmer
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - James D Mills
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Floor E Jansen
- Department of Pediatric Neurology, Brain Center University Medical Center
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht (WGMS) Utrecht, The Netherlands
| | | | | | - Roland Coras
- Second Faculty of Medicine, Charles University, Motol University Hospital, Prague, Czech Republic; Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Ingmar Blumcke
- Second Faculty of Medicine, Charles University, Motol University Hospital, Prague, Czech Republic; Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | | | | | | | | | - Figen Söylemezoğlu
- Medical University of Vienna, Vienna, Austria; Department of Pathology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Katarzyna Kotulska
- Department of Neurology and Epileptology, The Children's Memorial Health Institute, Warsaw, Poland
| | - Lieven Lagae
- Department of Development and Regeneration-Section Pediatric Neurology, University Hospitals KU Leuven, Leuven
| | - Anna C Jansen
- Pediatric Neurology Unit-UZ Brussel, Brussels Belgium
| | | | - Sergiusz Jozwiak
- Department of Neurology and Epileptology, The Children's Memorial Health Institute.,Department of Child Neurology, Medical University of Warsaw Warsaw, Poland
| | - Paolo Curatolo
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Tor Vergata University, Rome, Italy
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
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12
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de Curtis M, Garbelli R, Uva L. A hypothesis for the role of axon demyelination in seizure generation. Epilepsia 2021; 62:583-595. [PMID: 33493363 DOI: 10.1111/epi.16824] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 01/06/2023]
Abstract
Loss of myelin and altered oligodendrocyte distribution in the cerebral cortex are commonly observed both in postsurgical tissue derived from different focal epilepsies (such as focal cortical dysplasias and tuberous sclerosis) and in animal models of focal epilepsy. Moreover, seizures are a frequent symptom in demyelinating diseases, such as multiple sclerosis, and in animal models of demyelination and oligodendrocyte dysfunction. Finally, the excessive activity reported in demyelinated axons may promote hyperexcitability. We hypothesize that the extracellular potassium rise generated during epileptiform activity may be amplified by the presence of axons without appropriate myelin coating and by alterations in oligodendrocyte function. This process could facilitate the triggering of recurrent spontaneous seizures in areas of altered myelination and could result in further demyelination, thus promoting epileptogenesis.
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Affiliation(s)
- Marco de Curtis
- Epilepsy Unit, IRCCS Foundation Carlo Besta Neurological Institute, Milan, Italy
| | - Rita Garbelli
- Epilepsy Unit, IRCCS Foundation Carlo Besta Neurological Institute, Milan, Italy
| | - Laura Uva
- Epilepsy Unit, IRCCS Foundation Carlo Besta Neurological Institute, Milan, Italy
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13
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Yi JH, Kwon H, Cho E, Jeon J, Lee J, Lee YC, Cho JH, Jun M, Moon M, Ryu JH, Kim JS, Choi JW, Park SJ, Lee S, Kim DH. REDD1 Is Involved in Amyloid β-Induced Synaptic Dysfunction and Memory Impairment. Int J Mol Sci 2020; 21:ijms21249482. [PMID: 33322202 PMCID: PMC7763153 DOI: 10.3390/ijms21249482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 01/02/2023] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disease characterized by neurological dysfunction, including memory impairment, attributed to the accumulation of amyloid β (Aβ) in the brain. Although several studies reported possible mechanisms involved in Aβ pathology, much remains unknown. Previous findings suggested that a protein regulated in development and DNA damage response 1 (REDD1), a stress-coping regulator, is an Aβ-responsive gene involved in Aβ cytotoxicity. However, we still do not know how Aβ increases the level of REDD1 and whether REDD1 mediates Aβ-induced synaptic dysfunction. To elucidate this, we examined the effect of Aβ on REDD1-expression using acute hippocampal slices from mice, and the effect of REDD1 short hairpin RNA (shRNA) on Aβ-induced synaptic dysfunction. Lastly, we observed the effect of REDD1 shRNA on memory deficit in an AD-like mouse model. Through the experiments, we found that Aβ-incubated acute hippocampal slices showed increased REDD1 levels. Moreover, Aβ injection into the lateral ventricle increased REDD1 levels in the hippocampus. Anisomycin, but not actinomycin D, blocked Aβ-induced increase in REDD1 levels in the acute hippocampal slices, suggesting that Aβ may increase REDD1 translation rather than transcription. Aβ activated Fyn/ERK/S6 cascade, and inhibitors for Fyn/ERK/S6 or mGluR5 blocked Aβ-induced REDD1 upregulation. REDD1 inducer, a transcriptional activator, and Aβ blocked synaptic plasticity in the acute hippocampal slices. REDD1 inducer inhibited mTOR/Akt signaling. REDD1 shRNA blocked Aβ-induced synaptic deficits. REDD1 shRNA also blocked Aβ-induced memory deficits in passive-avoidance and object-recognition tests. Collectively, these results demonstrate that REDD1 participates in Aβ pathology and could be a target for AD therapy.
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Affiliation(s)
- Jee Hyun Yi
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science, Daejeon 34141, Korea;
| | - Huiyoung Kwon
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
| | - Eunbi Cho
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
| | - Jieun Jeon
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
| | - Jeongwon Lee
- Department of Marine Life Science, Jeju National University, Jeju 63241, Korea;
| | - Young Choon Lee
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
| | - Jong Hyun Cho
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
| | - Mira Jun
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Korea;
| | - Jong Hoon Ryu
- Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul 02447, Korea;
| | - Ji-Su Kim
- Primate Resources Center (PRC), Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongup-si, Jeollabuk-do 56216, Korea;
| | - Ji Woong Choi
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon 21936, Korea;
| | - Se Jin Park
- School of Natural Resources and Environmental Sciences, Kangwon National University, Chuncheon 24341, Korea;
| | - Seungheon Lee
- Department of Marine Life Science, Jeju National University, Jeju 63241, Korea;
- Correspondence: (S.L.); (D.H.K.); Tel.: +82-51-200-7583 (S.L.)
| | - Dong Hyun Kim
- Department of Health Sciences, The Graduate School of Dong-A University, Dong-A University, Busan 49315, Korea; (H.K.); (E.C.); (J.J.); (Y.C.L.); (J.H.C.); (M.J.)
- Institute of Convergence Bio-Health, Department of Health Sciences, The Graduate School of Dong-A University, Busan 49315, Korea
- Correspondence: (S.L.); (D.H.K.); Tel.: +82-51-200-7583 (S.L.)
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14
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Auderset L, Pitman KA, Cullen CL, Pepper RE, Taylor BV, Foa L, Young KM. Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1) Is a Negative Regulator of Oligodendrocyte Progenitor Cell Differentiation in the Adult Mouse Brain. Front Cell Dev Biol 2020; 8:564351. [PMID: 33282858 PMCID: PMC7691426 DOI: 10.3389/fcell.2020.564351] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 09/14/2020] [Indexed: 12/17/2022] Open
Abstract
Low-density lipoprotein receptor-related protein 1 (LRP1) is a large, endocytic cell surface receptor that is highly expressed by oligodendrocyte progenitor cells (OPCs) and LRP1 expression is rapidly downregulated as OPCs differentiate into oligodendrocytes (OLs). We report that the conditional deletion of Lrp1 from adult mouse OPCs (Pdgfrα-CreER :: Lrp1fl/fl) increases the number of newborn, mature myelinating OLs added to the corpus callosum and motor cortex. As these additional OLs extend a normal number of internodes that are of a normal length, Lrp1-deletion increases adult myelination. OPC proliferation is also elevated following Lrp1 deletion in vivo, however, this may be a secondary, homeostatic response to increased OPC differentiation, as our in vitro experiments show that LRP1 is a direct negative regulator of OPC differentiation, not proliferation. Deleting Lrp1 from adult OPCs also increases the number of newborn mature OLs added to the corpus callosum in response to cuprizone-induced demyelination. These data suggest that the selective blockade of LRP1 function on adult OPCs may enhance myelin repair in demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Kimberley A Pitman
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Bruce V Taylor
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Lisa Foa
- School of Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
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15
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Adams KL, Dahl KD, Gallo V, Macklin WB. Intrinsic and extrinsic regulators of oligodendrocyte progenitor proliferation and differentiation. Semin Cell Dev Biol 2020; 116:16-24. [PMID: 34110985 DOI: 10.1016/j.semcdb.2020.10.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 12/14/2022]
Abstract
Oligodendrocytes are highly specialized glial cells, responsible for producing myelin in the central nervous system (CNS). The multi-stage process of oligodendrocyte development is tightly regulated to ensure proper lineage progression of oligodendrocyte progenitor cells (OPCs) to mature myelin producing oligodendrocytes. This developmental process involves complex interactions between several intrinsic signaling pathways that are modulated by an array of extrinsic factors. Understanding these regulatory processes is of crucial importance, as it may help to identify specific molecular targets both to enhance plasticity in the normal CNS and to promote endogenous recovery following injury or disease. This review describes two major regulators that play important functional roles in distinct phases of oligodendrocyte development: OPC proliferation and differentiation. Specifically, we highlight the roles of the extracellular astrocyte/radial glia-derived protein Endothelin-1 in OPC proliferation and the intracellular Akt/mTOR pathway in OPC differentiation. Lastly, we reflect on how recent advances in neuroscience and scientific technology will enable greater understanding into how intrinsic and extrinsic regulators interact to generate oligodendrocyte diversity.
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Affiliation(s)
- Katrina L Adams
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC 20010, USA
| | - Kristin D Dahl
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Research Institute, Children's National Hospital, Washington, DC 20010, USA
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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16
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Zimmer TS, Broekaart DWM, Gruber VE, van Vliet EA, Mühlebner A, Aronica E. Tuberous Sclerosis Complex as Disease Model for Investigating mTOR-Related Gliopathy During Epileptogenesis. Front Neurol 2020; 11:1028. [PMID: 33041976 PMCID: PMC7527496 DOI: 10.3389/fneur.2020.01028] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/06/2020] [Indexed: 12/13/2022] Open
Abstract
Tuberous sclerosis complex (TSC) represents the prototypic monogenic disorder of the mammalian target of rapamycin (mTOR) pathway dysregulation. It provides the rational mechanistic basis of a direct link between gene mutation and brain pathology (structural and functional abnormalities) associated with a complex clinical phenotype including epilepsy, autism, and intellectual disability. So far, research conducted in TSC has been largely neuron-oriented. However, the neuropathological hallmarks of TSC and other malformations of cortical development also include major morphological and functional changes in glial cells involving astrocytes, oligodendrocytes, NG2 glia, and microglia. These cells and their interglial crosstalk may offer new insights into the common neurobiological mechanisms underlying epilepsy and the complex cognitive and behavioral comorbidities that are characteristic of the spectrum of mTOR-associated neurodevelopmental disorders. This review will focus on the role of glial dysfunction, the interaction between glia related to mTOR hyperactivity, and its contribution to epileptogenesis in TSC. Moreover, we will discuss how understanding glial abnormalities in TSC might give valuable insight into the pathophysiological mechanisms that could help to develop novel therapeutic approaches for TSC or other pathologies characterized by glial dysfunction and acquired mTOR hyperactivation.
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Affiliation(s)
- Till S Zimmer
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Diede W M Broekaart
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | | | - Erwin A van Vliet
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, Netherlands
| | - Angelika Mühlebner
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
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17
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Jiang Y, You M, Li S, Xu Y, Wang Y. Perinatal exposure to nonylphenol delayed myelination in offspring cerebellum. Biochem Pharmacol 2020; 178:114120. [PMID: 32589996 DOI: 10.1016/j.bcp.2020.114120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 06/11/2020] [Accepted: 06/19/2020] [Indexed: 01/06/2023]
Abstract
As a stable environmental contaminant, nonylphenol (NP) has been shown to induce some neurological deficits in the cerebellum, although the underlying mechanism is still unknown. In the present study, we aimed to investigate the effects of perinatal exposure to NP on myelination, an important process essential for the intact cerebellar function, in the offspring cerebellum. Exposure to NP delayed the myelination in the offspring cerebellum during perinatal period. The myelination recovered in the cerebellum of offspring exposed to NP over time, and returned to normal in adulthood. In addition, perinatal exposure to NP reduced mature oligodendrocytes (myelin-forming glial cells) and increased astrocytes in the offspring cerebellum. BMP signaling is believed to negatively regulate oligodendrogliogenesis and myelination. In the present study, BMP4, p-Smad1/5, and ID4, key members of BMP signaling, were increased in the cerebellum of offspring exposed to NP. Taken together, these lines of evidence suggest that the activation of BMP signaling may underlie the decreased oligodendrogliogenesis and increased astrogliogenesis, and the consequent delay of myelination in the cerebellum of offspring perinatally exposed to NP.
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Affiliation(s)
- Yuanjing Jiang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, PR China
| | - Mingdan You
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, PR China
| | - Siyao Li
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, PR China
| | - Yuanyuan Xu
- Program of Environmental Toxicology, School of Public Health, China Medical University, Shenyang, Liaoning, PR China
| | - Yi Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning, PR China.
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18
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Ornelas IM, Khandker L, Wahl SE, Hashimoto H, Macklin WB, Wood TL. The mechanistic target of rapamycin pathway downregulates bone morphogenetic protein signaling to promote oligodendrocyte differentiation. Glia 2020; 68:1274-1290. [PMID: 31904150 DOI: 10.1002/glia.23776] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 11/26/2019] [Accepted: 11/29/2019] [Indexed: 12/13/2022]
Abstract
Oligodendrocyte precursor cells (OPCs) differentiate and mature into oligodendrocytes, which produce myelin in the central nervous system. Prior studies have shown that the mechanistic target of rapamycin (mTOR) is necessary for proper myelination of the mouse spinal cord and that bone morphogenetic protein (BMP) signaling inhibits oligodendrocyte differentiation, in part by promoting expression of inhibitor of DNA binding 2 (Id2). Here we provide evidence that mTOR functions specifically in the transition from early stage OPC to immature oligodendrocyte by downregulating BMP signaling during postnatal spinal cord development. When mTOR is deleted from the oligodendrocyte lineage, expression of the FK506 binding protein 1A (FKBP12), a suppressor of BMP receptor activity, is reduced, downstream Smad activity is increased and Id2 expression is elevated. Additionally, mTOR inhibition with rapamycin in differentiating OPCs alters the transcriptional complex present at the Id2 promoter. Deletion of mTOR in oligodendroglia in vivo resulted in fewer late stage OPCs and fewer newly formed oligodendrocytes in the spinal cord with no effect on OPC proliferation or cell cycle exit. Finally, we demonstrate that inhibiting BMP signaling rescues the rapamycin-induced deficit in myelin protein expression. We conclude that mTOR promotes early oligodendrocyte differentiation by suppressing BMP signaling in OPCs.
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Affiliation(s)
- Isis M Ornelas
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Luipa Khandker
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Stacey E Wahl
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
| | - Hirokazu Hashimoto
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Teresa L Wood
- Department of Pharmacology, Physiology & Neuroscience, New Jersey Medical School, Rutgers University, Newark, New Jersey
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19
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Short B, Kozek L, Harmsen H, Zhang B, Wong M, Ess KC, Fu C, Naftel R, Pearson MM, Carson RP. Cerebral aquaporin-4 expression is independent of seizures in tuberous sclerosis complex. Neurobiol Dis 2019; 129:93-101. [PMID: 31078684 DOI: 10.1016/j.nbd.2019.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/23/2019] [Accepted: 05/08/2019] [Indexed: 12/26/2022] Open
Abstract
Astrocytes serve many functions in the human brain, many of which focus on maintenance of homeostasis. Astrocyte dysfunction in Tuberous Sclerosis Complex (TSC) has long been appreciated with activation of the mTORC1 signaling pathway resulting in gliosis and possibly contributing to the very frequent phenotype of epilepsy. We hypothesized that aberrant expression of the astrocyte protein aquaporin-4 (AQP4) may be present in TSC and contribute to disease pathology. Characterization of AQP4 expression in epileptic cortex from TSC patients demonstrated a diffuse increase in AQP4. To determine if this was due to exposure to seizures, we examined Aqp4 expression in mouse models of TSC in which Tsc1 or Tsc2 inactivation was targeted to astrocytes or glial progenitors, respectively. Loss of either Tsc1 or Tsc2 from astrocytes resulted in a marked increase in Aqp4 expression which was sensitive to mTORC1 inhibition with rapamycin. Our findings in both TSC epileptogenic cortex and in a variety of astrocyte culture models demonstrate for the first time that AQP4 expression is dysregulated in TSC. The extent to which AQP4 contributes to epilepsy in TSC is not known, though the similarities in AQP4 expression between TSC and temporal lobe epilepsy supports further studies targeting AQP4 in TSC.
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Affiliation(s)
- Brittany Short
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, United States
| | - Lindsay Kozek
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, United States; Vanderbilt Brain Institute, Vanderbilt University, United States
| | - Hannah Harmsen
- Department of Pathology, Vanderbilt University Medical Center, United States
| | - Bo Zhang
- Departments of Neurology, Pediatrics, and Neuroscience, Washington University School of Medicine, United States
| | - Michael Wong
- Departments of Neurology, Pediatrics, and Neuroscience, Washington University School of Medicine, United States
| | - Kevin C Ess
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, United States; Vanderbilt Brain Institute, Vanderbilt University, United States
| | - Cary Fu
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, United States
| | - Robert Naftel
- Department of Neurosurgery, Vanderbilt University Medical Center, United States
| | | | - Robert P Carson
- Department of Pediatrics, Division of Pediatric Neurology, Vanderbilt University Medical Center, United States; Vanderbilt Brain Institute, Vanderbilt University, United States; Department of Pharmacology, Vanderbilt University Medical Center, United States.
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20
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Sun T, Liu Z, Liu M, Guo Y, Sun H, Zhao J, Lan Z, Lian B, Zhang J. Hippocampus-specific Rictor knockdown inhibited 17β-estradiol induced neuronal plasticity and spatial memory improvement in ovariectomized mice. Behav Brain Res 2019; 364:50-61. [DOI: 10.1016/j.bbr.2019.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 02/08/2019] [Accepted: 02/09/2019] [Indexed: 11/19/2022]
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