1
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Yu SB, Wang H, Sanchez RG, Carlson NM, Nguyen K, Zhang A, Papich ZD, Abushawish AA, Whiddon Z, Matysik W, Zhang J, Whisenant TC, Ghassemian M, Koberstein JN, Stewart ML, Myers SA, Pekkurnaz G. Neuronal activity-driven O-GlcNAcylation promotes mitochondrial plasticity. Dev Cell 2024:S1534-5807(24)00325-3. [PMID: 38843836 DOI: 10.1016/j.devcel.2024.05.008] [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: 01/12/2023] [Revised: 02/15/2024] [Accepted: 05/09/2024] [Indexed: 06/18/2024]
Abstract
Neuronal activity is an energy-intensive process that is largely sustained by instantaneous fuel utilization and ATP synthesis. However, how neurons couple ATP synthesis rate to fuel availability is largely unknown. Here, we demonstrate that the metabolic sensor enzyme O-linked N-acetyl glucosamine (O-GlcNAc) transferase regulates neuronal activity-driven mitochondrial bioenergetics in hippocampal and cortical neurons. We show that neuronal activity upregulates O-GlcNAcylation in mitochondria. Mitochondrial O-GlcNAcylation is promoted by activity-driven glucose consumption, which allows neurons to compensate for high energy expenditure based on fuel availability. To determine the proteins that are responsible for these adjustments, we mapped the mitochondrial O-GlcNAcome of neurons. Finally, we determine that neurons fail to meet activity-driven metabolic demand when O-GlcNAcylation dynamics are prevented. Our findings suggest that O-GlcNAcylation provides a fuel-dependent feedforward control mechanism in neurons to optimize mitochondrial performance based on neuronal activity. This mechanism thereby couples neuronal metabolism to mitochondrial bioenergetics and plays a key role in sustaining energy homeostasis.
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Affiliation(s)
- Seungyoon B Yu
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Haoming Wang
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Richard G Sanchez
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Natasha M Carlson
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Khanh Nguyen
- Laboratory for Immunochemical Circuits, Center of Autoimmunity and Inflammation, and Division of Signaling and Gene Expression, La Jolla Institute for Immunology, La Jolla, CA 92093, USA
| | - Andrew Zhang
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Zachary D Papich
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Ahmed A Abushawish
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Zachary Whiddon
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Weronika Matysik
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jie Zhang
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Thomas C Whisenant
- Center for Computational Biology and Bioinformatics, University of California San Diego, La Jolla, CA 92093, USA
| | - Majid Ghassemian
- Biomolecular and Proteomics Mass Spectrometry Facility, University of California San Diego, La Jolla, CA 92093, USA
| | - John N Koberstein
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Melissa L Stewart
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Samuel A Myers
- Laboratory for Immunochemical Circuits, Center of Autoimmunity and Inflammation, and Division of Signaling and Gene Expression, La Jolla Institute for Immunology, La Jolla, CA 92093, USA; Department of Pharmacology, Program in Immunology, and Moores Cancer Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Gulcin Pekkurnaz
- Neurobiology Department, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA.
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2
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Authier F, Ondruskova N, Ferenbach AT, McNeilly AD, van Aalten DMF. Neurodevelopmental defects in a mouse model of O-GlcNAc transferase intellectual disability. Dis Model Mech 2024; 17:dmm050671. [PMID: 38566589 PMCID: PMC11095632 DOI: 10.1242/dmm.050671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 03/15/2024] [Indexed: 04/04/2024] Open
Abstract
The addition of O-linked β-N-acetylglucosamine (O-GlcNAc) to proteins (referred to as O-GlcNAcylation) is a modification that is crucial for vertebrate development. O-GlcNAcylation is catalyzed by O-GlcNAc transferase (OGT) and reversed by O-GlcNAcase (OGA). Missense variants of OGT have recently been shown to segregate with an X-linked syndromic form of intellectual disability, OGT-linked congenital disorder of glycosylation (OGT-CDG). Although the existence of OGT-CDG suggests that O-GlcNAcylation is crucial for neurodevelopment and/or cognitive function, the underlying pathophysiologic mechanisms remain unknown. Here we report a mouse line that carries a catalytically impaired OGT-CDG variant. These mice show altered O-GlcNAc homeostasis with decreased global O-GlcNAcylation and reduced levels of OGT and OGA in the brain. Phenotypic characterization of the mice revealed lower body weight associated with reduced body fat mass, short stature and microcephaly. This mouse model will serve as an important tool to study genotype-phenotype correlations in OGT-CDG in vivo and for the development of possible treatment avenues for this disorder.
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Affiliation(s)
- Florence Authier
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Nina Ondruskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, 128 08 Praha 2, Czech Republic
| | - Andrew T. Ferenbach
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
| | - Alison D. McNeilly
- Division of Systems Medicine, School of Medicine, University of Dundee, Dundee DD1 9SY, UK
| | - Daan M. F. van Aalten
- Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus, Denmark
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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3
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Han S, Kim JN, Park CH, Byun JS, Kim DY, Ko HG. Modulation of synaptic transmission through O-GlcNAcylation. Mol Brain 2024; 17:1. [PMID: 38167470 PMCID: PMC10759587 DOI: 10.1186/s13041-023-01072-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024] Open
Abstract
O-GlcNAcylation is a posttranslational modification where N-acetylglucosamine (O-GlcNAc) is attached and detached from a serine/threonine position by two enzymes: O-GlcNAc transferase and O-GlcNAcase. In addition to roles in diabetes and cancer, recent pharmacological and genetic studies have revealed that O-GlcNAcylation is involved in neuronal function, specifically synaptic transmission. Global alteration of the O-GlcNAc level does not affect basal synaptic transmission while the effect on synaptic plasticity is unclear. Although synaptic proteins that are O-GlcNAcylated are gradually being discovered, the mechanism of how O-GlcNAcylated synaptic protein modulate synaptic transmission has only been reported on CREB, synapsin, and GluA2 subunit of AMPAR. Future research enabling the manipulation of O-GlcNAcylation in individual synaptic proteins should reveal hidden aspects of O-GlcNAcylated synaptic proteins as modulators of synaptic transmission.
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Affiliation(s)
- Seunghyo Han
- Department of Anatomy and Neurobiology, School of Dentistry, Brain Science and Engineering Institute, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 41940, South Korea
| | - Jun-Nyeong Kim
- Department of Anatomy and Neurobiology, School of Dentistry, Brain Science and Engineering Institute, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 41940, South Korea
| | - Chan Ho Park
- Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, Daegu, 41940, Republic of Korea
| | - Jin-Seok Byun
- Department of Oral Medicine, School of Dentistry, Kyungpook National University, Daegu, 41940, Republic of Korea
| | - Do-Yeon Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, 41940, Republic of Korea
| | - Hyoung-Gon Ko
- Department of Anatomy and Neurobiology, School of Dentistry, Brain Science and Engineering Institute, Kyungpook National University, 2177 Dalgubeol-daero, Daegu, 41940, South Korea.
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4
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Kim DY, Park J, Han IO. Hexosamine biosynthetic pathway and O-GlcNAc cycling of glucose metabolism in brain function and disease. Am J Physiol Cell Physiol 2023; 325:C981-C998. [PMID: 37602414 DOI: 10.1152/ajpcell.00191.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/03/2023] [Accepted: 08/03/2023] [Indexed: 08/22/2023]
Abstract
Impaired brain glucose metabolism is considered a hallmark of brain dysfunction and neurodegeneration. Disruption of the hexosamine biosynthetic pathway (HBP) and subsequent O-linked N-acetylglucosamine (O-GlcNAc) cycling has been identified as an emerging link between altered glucose metabolism and defects in the brain. Myriads of cytosolic and nuclear proteins in the nervous system are modified at serine or threonine residues with a single N-acetylglucosamine (O-GlcNAc) molecule by O-GlcNAc transferase (OGT), which can be removed by β-N-acetylglucosaminidase (O-GlcNAcase, OGA). Homeostatic regulation of O-GlcNAc cycling is important for the maintenance of normal brain activity. Although significant evidence linking dysregulated HBP metabolism and aberrant O-GlcNAc cycling to induction or progression of neuronal diseases has been obtained, the issue of whether altered O-GlcNAcylation is causal in brain pathogenesis remains uncertain. Elucidation of the specific functions and regulatory mechanisms of individual O-GlcNAcylated neuronal proteins in both normal and diseased states may facilitate the identification of novel therapeutic targets for various neuronal disorders. The information presented in this review highlights the importance of HBP/O-GlcNAcylation in the neuronal system and summarizes the roles and potential mechanisms of O-GlcNAcylated neuronal proteins in maintaining normal brain function and initiation and progression of neurological diseases.
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Affiliation(s)
- Dong Yeol Kim
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, South Korea
| | - Jiwon Park
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, South Korea
| | - Inn-Oc Han
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, South Korea
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5
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Zaninello M, Bean C. Highly Specialized Mechanisms for Mitochondrial Transport in Neurons: From Intracellular Mobility to Intercellular Transfer of Mitochondria. Biomolecules 2023; 13:938. [PMID: 37371518 DOI: 10.3390/biom13060938] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 05/26/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
The highly specialized structure and function of neurons depend on a sophisticated organization of the cytoskeleton, which supports a similarly sophisticated system to traffic organelles and cargo vesicles. Mitochondria sustain crucial functions by providing energy and buffering calcium where it is needed. Accordingly, the distribution of mitochondria is not even in neurons and is regulated by a dynamic balance between active transport and stable docking events. This system is finely tuned to respond to changes in environmental conditions and neuronal activity. In this review, we summarize the mechanisms by which mitochondria are selectively transported in different compartments, taking into account the structure of the cytoskeleton, the molecular motors and the metabolism of neurons. Remarkably, the motor proteins driving the mitochondrial transport in axons have been shown to also mediate their transfer between cells. This so-named intercellular transport of mitochondria is opening new exciting perspectives in the treatment of multiple diseases.
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Affiliation(s)
- Marta Zaninello
- Institute for Genetics, University of Cologne, 50931 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
| | - Camilla Bean
- Department of Medicine, University of Udine, 33100 Udine, Italy
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6
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Jaillard C, Ouechtati F, Clérin E, Millet-Puel G, Corsi M, Aït-Ali N, Blond F, Chevy Q, Gales L, Farinelli M, Dalkara D, Sahel JA, Portais JC, Poncer JC, Léveillard T. The metabolic signaling of the nucleoredoxin-like 2 gene supports brain function. Redox Biol 2021; 48:102198. [PMID: 34856436 PMCID: PMC8640531 DOI: 10.1016/j.redox.2021.102198] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 11/22/2021] [Indexed: 01/04/2023] Open
Abstract
The nucleoredoxin gene NXNL2 encodes for two products through alternative splicing, rod-derived cone viability factor-2 (RdCVF2) that mediates neuronal survival and the thioredoxin-related protein (RdCVF2L), an enzyme that regulates the phosphorylation of TAU. To investigate the link between NXNL2 and tauopathies, we studied the Nxnl2 knockout mouse (Nxnl2-/-). We established the expression pattern of the Nxnl2 gene in the brain using a Nxnl2 reporter mouse line, and characterized the behavior of the Nxnl2-/- mouse at 2 months of age. Additionally, long term potentiation and metabolomic from hippocampal specimens were collected at 2 months of age. We studied TAU oligomerization, phosphorylation and aggregation in Nxnl2-/- brain at 18 months of age. Finally, newborn Nxnl2-/- mice were treated with adeno-associated viral vectors encoding for RdCVF2, RdCVF2L or both and measured the effect of this therapy on long-term potential, glucose metabolism and late-onset tauopathy. Nxnl2-/- mice at 2 months of age showed severe behavioral deficiency in fear, pain sensitivity, coordination, learning and memory. The Nxnl2-/- also showed deficits in long-term potentiation, demonstrating that the Nxnl2 gene is involved in regulating brain functions. Dual delivery of RdCVF2 and RdCVF2L in newborn Nxnl2-/- mice fully correct long-term potentiation through their synergistic action. The expression pattern of the Nxnl2 gene in the brain shows a predominant expression in circumventricular organs, such as the area postrema. Glucose metabolism of the hippocampus of Nxnl2-/- mice at 2 months of age was reduced, and was not corrected by gene therapy. At 18-month-old Nxnl2-/- mice showed brain stigmas of tauopathy, such as oligomerization, phosphorylation and aggregation of TAU. This late-onset tauopathy can be prevented, albeit with modest efficacy, by recombinant AAVs administrated to newborn mice. The Nxnl2-/- mice have memory dysfunction at 2-months that resembles mild-cognitive impairment and at 18-months exhibit tauopathy, resembling to the progression of Alzheimer's disease. We propose the Nxnl2-/- mouse is a model to study multistage aged related neurodegenerative diseases. The NXNL2 metabolic and redox signaling is a new area of therapeutic research in neurodegenerative diseases.
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Affiliation(s)
- Céline Jaillard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - Farah Ouechtati
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - Emmanuelle Clérin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | | | - Mariangela Corsi
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - Najate Aït-Ali
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - Frédéric Blond
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - Quentin Chevy
- Sorbonne Université, INSERM, CNRS, Institut du Fer à Moulin, F-75005, Paris, France
| | - Lara Gales
- MetaToul-MetaboHUB, National Infrastructure of Metabolomics & Fluxomics, 31077, Toulouse, France
| | - Mélissa Farinelli
- E-Phy-Science, Bioparc de Sophia Antipolis, 2400 route des Colles, 06410, Biot, France
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France
| | - Jean-Charles Portais
- MetaToul-MetaboHUB, National Infrastructure of Metabolomics & Fluxomics, 31077, Toulouse, France
| | | | - Thierry Léveillard
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-7501b, Paris, France.
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7
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Kim SM, Zhang S, Park J, Sung HJ, Tran TDT, Chung C, Han IO. REM Sleep Deprivation Impairs Learning and Memory by Decreasing Brain O-GlcNAc Cycling in Mouse. Neurotherapeutics 2021; 18:2504-2517. [PMID: 34312767 PMCID: PMC8804064 DOI: 10.1007/s13311-021-01094-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2021] [Indexed: 12/17/2022] Open
Abstract
Rapid eye movement (REM) sleep is implicated learning and memory (L/M) functions and hippocampal long-term potentiation (LTP). Here, we demonstrate that REM sleep deprivation (REMSD)-induced impairment of contextual fear memory in mouse is linked to a reduction in hexosamine biosynthetic pathway (HBP)/O-GlcNAc flux in mouse brain. In mice exposed to REMSD, O-GlcNAcylation, and O-GlcNAc transferase (OGT) were downregulated while O-GlcNAcase was upregulated compared to control mouse brain. Foot shock fear conditioning (FC) induced activation of protein kinase A (PKA) and cAMP response element binding protein (CREB), which were significantly inhibited in brains of the REMSD group. Intriguingly, REMSD-induced defects in L/M functions and FC-induced PKA/CREB activation were restored upon increasing O-GlcNAc cycling with glucosamine (GlcN) or Thiamet G. Furthermore, Thiamet G restored the REMSD-induced decrease in dendritic spine density. Suppression of O-GlcNAcylation by the glutamine fructose-6-phosphate amidotransferase (GFAT) inhibitor, 6-diazo-5-oxo-L-norleucine (DON), or OGT inhibitor, OSMI-1, impaired memory function, and inhibited FC-induced PKA/CREB activation. DON additionally reduced the amplitude of baseline field excitatory postsynaptic potential (fEPSP) and magnitude of long-term potentiation (LTP) in normal mouse hippocampal slices. To our knowledge, this is the first study to provide comprehensive evidence of dynamic O-GlcNAcylation changes during the L/M process in mice and defects in this pathway in the brain of REM sleep-deprived mice. Our collective results highlight HBP/O-GlcNAc cycling as a novel molecular link between sleep and cognitive function.
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Affiliation(s)
- Sang-Min Kim
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, Korea
| | - Seungjae Zhang
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Jiwon Park
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, Korea
| | - Hyun Jae Sung
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, Korea
| | - Thuy-Duong Thi Tran
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, Korea
| | - ChiHye Chung
- Department of Biological Sciences, Konkuk University, Seoul, Korea
| | - Inn-Oc Han
- Department of Biomedical Science, Program in Biomedical Science and Engineering, College of Medicine, Inha University, Incheon, Korea.
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8
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Rahmani A, Chew YL. Investigating the molecular mechanisms of learning and memory using Caenorhabditis elegans. J Neurochem 2021; 159:417-451. [PMID: 34528252 DOI: 10.1111/jnc.15510] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 08/15/2021] [Accepted: 09/08/2021] [Indexed: 11/30/2022]
Abstract
Learning is an essential biological process for survival since it facilitates behavioural plasticity in response to environmental changes. This process is mediated by a wide variety of genes, mostly expressed in the nervous system. Many studies have extensively explored the molecular and cellular mechanisms underlying learning and memory. This review will focus on the advances gained through the study of the nematode Caenorhabditis elegans. C. elegans provides an excellent system to study learning because of its genetic tractability, in addition to its invariant, compact nervous system (~300 neurons) that is well-characterised at the structural level. Importantly, despite its compact nature, the nematode nervous system possesses a high level of conservation with mammalian systems. These features allow the study of genes within specific sensory-, inter- and motor neurons, facilitating the interrogation of signalling pathways that mediate learning via defined neural circuits. This review will detail how learning and memory can be studied in C. elegans through behavioural paradigms that target distinct sensory modalities. We will also summarise recent studies describing mechanisms through which key molecular and cellular pathways are proposed to affect associative and non-associative forms of learning.
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Affiliation(s)
- Aelon Rahmani
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute, Flinders University, Adelaide, South Australia, Australia
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9
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Ahnaou A, Drinkenburg WHIM. Sleep, neuronal hyperexcitability, inflammation and neurodegeneration: Does early chronic short sleep trigger and is it the key to overcoming Alzheimer's disease? Neurosci Biobehav Rev 2021; 129:157-179. [PMID: 34214513 DOI: 10.1016/j.neubiorev.2021.06.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 05/13/2021] [Accepted: 06/25/2021] [Indexed: 01/13/2023]
Abstract
Evidence links neuroinflammation to Alzheimer's disease (AD); however, its exact contribution to the onset and progression of the disease is poorly understood. Symptoms of AD can be seen as the tip of an iceberg, consisting of a neuropathological build-up in the brain of extracellular amyloid-β (Aβ) plaques and intraneuronal hyperphosphorylated aggregates of Tau (pTau), which are thought to stem from an imbalance between its production and clearance resulting in loss of synaptic health and dysfunctional cortical connectivity. The glymphatic drainage system, which is particularly active during sleep, plays a key role in the clearance of proteinopathies. Poor sleep can cause hyperexcitability and promote Aβ and tau pathology leading to systemic inflammation. The early neuronal hyperexcitability of γ-aminobutyric acid (GABA)-ergic inhibitory interneurons and impaired inhibitory control of cortical pyramidal neurons lie at the crossroads of excitatory/inhibitory imbalance and inflammation. We outline, with a prospective framework, a possible vicious spiral linking early chronic short sleep, neuronal hyperexcitability, inflammation and neurodegeneration. Understanding the early predictors of AD, through an integrative approach, may hold promise for reducing attrition in the late stages of neuroprotective drug development.
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Affiliation(s)
- A Ahnaou
- Dept. of Neuroscience Discovery, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, B-2340, Belgium.
| | - W H I M Drinkenburg
- Dept. of Neuroscience Discovery, Janssen Research & Development, A Division of Janssen Pharmaceutica NV, Turnhoutseweg 30, Beerse, B-2340, Belgium
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10
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Andersson B, Tan EP, McGreal SR, Apte U, Hanover JA, Slawson C, Lagerlöf O. O-GlcNAc cycling mediates energy balance by regulating caloric memory. Appetite 2021; 165:105320. [PMID: 34029673 DOI: 10.1016/j.appet.2021.105320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/26/2022]
Abstract
Caloric need has long been thought a major driver of appetite. However, it is unclear whether caloric need regulates appetite in environments offered by many societies today where there is no shortage of food. Here we observed that wildtype mice with free access to food did not match calorie intake to calorie expenditure. While the size of a meal affected subsequent intake, there was no compensation for earlier under- or over-consumption. To test how spontaneous eating is subject to caloric control, we manipulated O-linked β-N-acetylglucosamine (O-GlcNAc), an energy signal inside cells dependent on nutrient access and metabolic hormones. Genetic and pharmacological manipulation in mice increasing or decreasing O-GlcNAcylation regulated daily intake by controlling meal size. Meal size was affected at least in part due to faster eating speed. Without affecting meal frequency, O-GlcNAc disrupted the effect of caloric consumption on future intake. Across days, energy balance was improved upon increased O-GlcNAc levels and impaired upon removal of O-GlcNAcylation. Rather than affecting a perceived need for calories, O-GlcNAc regulates how a meal affects future intake, suggesting that O-GlcNAc mediates a caloric memory and subsequently energy balance.
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Affiliation(s)
- Björn Andersson
- Department of Pediatric Surgery, Uppsala University Hospital, 75185, Uppsala, Sweden
| | - Ee Phie Tan
- Sanford Burnham Prebys Medical Discovery Institute, 92037, CA, USA
| | - Steven R McGreal
- Department of Pharmacology, Toxicology and Therapeutics, Kansas University, 66160, KS, USA
| | - Udayan Apte
- Department of Pharmacology, Toxicology and Therapeutics, Kansas University, 66160, KS, USA
| | - John A Hanover
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institute of Health, 20892, MD, USA
| | - Chad Slawson
- Department of Biochemistry and Molecular Biology, Kansas University, 66160, KS, USA
| | - Olof Lagerlöf
- Department of Clinical Sciences, Umeå University, 901 87, Umeå, Sweden; Department of Integrative Medical Biology, Umeå University, 901 87, Umeå, Sweden; Wallenberg Centre for Molecular Medicine, Umeå University, 901 87, Umeå, Sweden.
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11
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Bolanle IO, Riches-Suman K, Loubani M, Williamson R, Palmer TM. Revascularisation of type 2 diabetics with coronary artery disease: Insights and therapeutic targeting of O-GlcNAcylation. Nutr Metab Cardiovasc Dis 2021; 31:1349-1356. [PMID: 33812732 DOI: 10.1016/j.numecd.2021.01.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 01/18/2021] [Accepted: 01/22/2021] [Indexed: 12/12/2022]
Abstract
AIM Coronary artery bypass graft (CABG) using autologous saphenous vein continues to be a gold standard procedure to restore the supply of oxygen-rich blood to the heart muscles in coronary artery disease (CAD) patients with or without type 2 diabetes mellitus (T2DM). However, CAD patients with T2DM are at higher risk of graft failure. While failure rates have been reduced through improvements in procedure-related factors, much less is known about the molecular and cellular mechanisms by which T2DM initiates vein graft failure. This review gives novel insights into these cellular and molecular mechanisms and identifies potential therapeutic targets for development of new medicines to improve vein graft patency. DATA SYNTHESIS One important cellular process that has been implicated in the pathogenesis of T2DM is protein O-GlcNAcylation, a dynamic, reversible post-translational modification of serine and threonine residues on target proteins that is controlled by two enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Protein O-GlcNAcylation impacts a range of cellular processes, including trafficking, metabolism, inflammation and cytoskeletal organisation. Altered O-GlcNAcylation homeostasis have, therefore, been linked to a range of human pathologies with a metabolic component, including T2DM. CONCLUSION We propose that protein O-GlcNAcylation alters vascular smooth muscle and endothelial cell function through modification of specific protein targets which contribute to the vascular re-modelling responsible for saphenous vein graft failure in T2DM.
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Affiliation(s)
- Israel O Bolanle
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK
| | - Kirsten Riches-Suman
- School of Chemistry and Biosciences, University of Bradford, Bradford BD7 1DP, UK
| | - Mahmoud Loubani
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Ritchie Williamson
- School of Pharmacy and Medical Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Timothy M Palmer
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, University of Hull, Hull HU6 7RX, UK.
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12
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Muha V, Authier F, Szoke-Kovacs Z, Johnson S, Gallagher J, McNeilly A, McCrimmon RJ, Teboul L, van Aalten DMF. Loss of O-GlcNAcase catalytic activity leads to defects in mouse embryogenesis. J Biol Chem 2021; 296:100439. [PMID: 33610549 PMCID: PMC7988489 DOI: 10.1016/j.jbc.2021.100439] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/02/2021] [Accepted: 02/17/2021] [Indexed: 02/08/2023] Open
Abstract
O-GlcNAcylation is an essential post-translational modification that has been implicated in neurodevelopmental and neurodegenerative disorders. O-GlcNAcase (OGA), the sole enzyme catalyzing the removal of O-GlcNAc from proteins, has emerged as a potential drug target. OGA consists of an N-terminal OGA catalytic domain and a C-terminal pseudo histone acetyltransferase (HAT) domain with unknown function. To investigate phenotypes specific to loss of OGA catalytic activity and dissect the role of the HAT domain, we generated a constitutive knock-in mouse line, carrying a mutation of a catalytic aspartic acid to alanine. These mice showed perinatal lethality and abnormal embryonic growth with skewed Mendelian ratios after day E18.5. We observed tissue-specific changes in O-GlcNAc homeostasis regulation to compensate for loss of OGA activity. Using X-ray microcomputed tomography on late gestation embryos, we identified defects in the kidney, brain, liver, and stomach. Taken together, our data suggest that developmental defects during gestation may arise upon prolonged OGA inhibition specifically because of loss of OGA catalytic activity and independent of the function of the HAT domain.
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Affiliation(s)
- Villő Muha
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Florence Authier
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | | | - Sara Johnson
- The Mary Lyon Centre, MRC Harwell Institute, Oxfordshire, UK
| | - Jennifer Gallagher
- Division of Molecular & Clinical Medicine, University of Dundee, Dundee, UK
| | - Alison McNeilly
- System Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Rory J McCrimmon
- Division of Molecular & Clinical Medicine, University of Dundee, Dundee, UK
| | - Lydia Teboul
- The Mary Lyon Centre, MRC Harwell Institute, Oxfordshire, UK
| | - Daan M F van Aalten
- Division of Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK.
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13
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Increased O-GlcNAcylation rapidly decreases GABA AR currents in hippocampus but depresses neuronal output. Sci Rep 2020; 10:7494. [PMID: 32366857 PMCID: PMC7198489 DOI: 10.1038/s41598-020-63188-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 03/02/2020] [Indexed: 02/08/2023] Open
Abstract
O-GlcNAcylation, a post-translational modification involving O-linkage of β-N-acetylglucosamine to Ser/Thr residues on target proteins, is increasingly recognized as a critical regulator of synaptic function. Enzymes that catalyze O-GlcNAcylation are found at both presynaptic and postsynaptic sites, and O-GlcNAcylated proteins localize to synaptosomes. An acute increase in O-GlcNAcylation can affect neuronal communication by inducing long-term depression (LTD) of excitatory transmission at hippocampal CA3-CA1 synapses, as well as suppressing hyperexcitable circuits in vitro and in vivo. Despite these findings, to date, no studies have directly examined how O-GlcNAcylation modulates the efficacy of inhibitory neurotransmission. Here we show an acute increase in O-GlcNAc dampens GABAergic currents onto principal cells in rodent hippocampus likely through a postsynaptic mechanism, and has a variable effect on the excitation/inhibition balance. The overall effect of increased O-GlcNAc is reduced synaptically-driven spike probability via synaptic depression and decreased intrinsic excitability. Our results position O-GlcNAcylation as a novel regulator of the overall excitation/inhibition balance and neuronal output.
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14
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Cho Y, Hwang H, Rahman MA, Chung C, Rhim H. Elevated O-GlcNAcylation induces an antidepressant-like phenotype and decreased inhibitory transmission in medial prefrontal cortex. Sci Rep 2020; 10:6924. [PMID: 32332789 PMCID: PMC7181662 DOI: 10.1038/s41598-020-63819-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 03/23/2020] [Indexed: 12/24/2022] Open
Abstract
Depression is a devastating mental disorder affected by multiple factors that can have genetic, environmental, or metabolic causes. Although previous studies have reported an association of dysregulated glucose metabolism with depression, its underlying mechanism remains elusive at the molecular level. A small percentage of glucose is converted into uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) via the hexosamine biosynthetic pathway, which serves as an immediate donor for protein O-GlcNAc modification. O-GlcNAcylation is a particularly common post-translational modification (PTM) in the brain, and the functional significance of O-GlcNAcylation in neurodegenerative diseases has been extensively reported. However, whether the degree of O-GlcNAc modification is associated with depressive disorder has not been examined. In this study, we show that increased O-GlcNAcylation levels reduce inhibitory synaptic transmission in the medial prefrontal cortex (mPFC), and that Oga+/− mice with chronically elevated O-GlcNAcylation levels exhibit an antidepressant-like phenotype. Moreover, we found that virus-mediated expression of OGA in the mPFC restored both antidepressant-like behavior and inhibitory synaptic transmission. Therefore, our results suggest that O-GlcNAc modification in the mPFC plays a significant role in regulating antidepressant-like behavior, highlighting that the modulation of O-GlcNAcylation levels in the brain may serve as a novel therapeutic candidate for antidepressants.
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Affiliation(s)
- Yoonjeong Cho
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, 02792, Republic of Korea
| | - Hongik Hwang
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Md Ataur Rahman
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - ChiHye Chung
- Department of Biological Science, Konkuk University, Seoul, 05029, Republic of Korea.
| | - Hyewhon Rhim
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea. .,Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology (UST), Seoul, 02792, Republic of Korea.
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15
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Muha V, Fenckova M, Ferenbach AT, Catinozzi M, Eidhof I, Storkebaum E, Schenck A, van Aalten DMF. O-GlcNAcase contributes to cognitive function in Drosophila. J Biol Chem 2020; 295:8636-8646. [PMID: 32094227 PMCID: PMC7324509 DOI: 10.1074/jbc.ra119.010312] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 02/07/2020] [Indexed: 12/27/2022] Open
Abstract
O-GlcNAcylation is an abundant post-translational modification in neurons. In mice, an increase in O-GlcNAcylation leads to defects in hippocampal synaptic plasticity and learning. O-GlcNAcylation is established by two opposing enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). To investigate the role of OGA in elementary learning, we generated catalytically inactive and precise knockout Oga alleles (OgaD133N and OgaKO , respectively) in Drosophila melanogaster Adult OgaD133N and OgaKO flies lacking O-GlcNAcase activity showed locomotor phenotypes. Importantly, both Oga lines exhibited deficits in habituation, an evolutionarily conserved form of learning, highlighting that the requirement for O-GlcNAcase activity for cognitive function is preserved across species. Loss of O-GlcNAcase affected a number of synaptic boutons at the axon terminals of larval neuromuscular junction. Taken together, we report behavioral and neurodevelopmental phenotypes associated with Oga alleles and show that Oga contributes to cognition and synaptic morphology in Drosophila.
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Affiliation(s)
- Villo Muha
- Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kindom
| | - Michaela Fenckova
- Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kindom; Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
| | - Andrew T Ferenbach
- Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kindom
| | - Marica Catinozzi
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and the Faculty of Science, Radboud University, 6525XZ Nijmegen, The Netherlands
| | - Ilse Eidhof
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
| | - Erik Storkebaum
- Department of Molecular Neurobiology, Donders Institute for Brain, Cognition and Behaviour and the Faculty of Science, Radboud University, 6525XZ Nijmegen, The Netherlands
| | - Annette Schenck
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, 6525GA Nijmegen, The Netherlands
| | - Daan M F van Aalten
- Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kindom.
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16
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Lee Y, Park J, Kim SM, Nam K, Lee W, Cho H, Han IO. Sleep deprivation impairs learning and memory by decreasing protein O-GlcNAcylation in the brain of adult zebrafish. FASEB J 2020; 34:853-864. [PMID: 31914627 DOI: 10.1096/fj.201901399rr] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/05/2019] [Accepted: 11/04/2019] [Indexed: 11/11/2022]
Abstract
Sleep is an evolutionarily conserved physiological process implicated in the consolidation of learning and memory (L/M). Here, we report that sleep deprivation (SD)-induced cognitive deficits in zebrafish are mediated through reduction in O-GlcNAcylation of brain. Microarray-based gene expression profiling of zebrafish brain demonstrated significant changes in genes involved in metabolism by SD or fear conditioning (FC), compared to the control group. In particular, it was observed that a marked decrease in the number of genes involved in carboxylic acid and organic acid metabolic processes in the brains of SD group compared to control group. SD downregulated O-GlcNAc transferase (OGT) and O-GlcNAcylation, while the expression of O-GlcNAcase was upregulated. FC activated protein kinase A (PKA) and phosphorylated cAMP response element binding protein (p-CREB), an effect that was greatly inhibited by SD. Moreover, FC upregulated expressions of OGT and increased O-GlcNAcylation in the brains of normal but not SD zebrafish. Intriguingly, upregulation of O-GlcNAcylation by glucosamine restored defects in L/M functions and PKA/p-CREB activity in SD group. Our findings highlight the O-GlcNAcylation changes in the brain during the L/M process and further provide a foundation for future studies seeking the molecular and biochemical mechanisms by which HBP of glucose metabolism affects cognitive function.
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Affiliation(s)
- Yunkyoung Lee
- Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea
| | - Jiwon Park
- Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea
| | - Sang-Min Kim
- Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea
| | - Kyunghyun Nam
- Department of Statistics, Inha University, Incheon, Korea
| | - Woojoo Lee
- Department of Statistics, Inha University, Incheon, Korea
| | - Hyeongjin Cho
- Department of Chemistry, Inha University, Incheon, Korea
| | - Inn-Oc Han
- Department of Physiology and Biophysics, College of Medicine, Inha University, Incheon, Korea
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17
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Butler AA, Sanchez RG, Jarome TJ, Webb WM, Lubin FD. O-GlcNAc and EZH2-mediated epigenetic regulation of gene expression during consolidation of fear memories. ACTA ACUST UNITED AC 2019; 26:373-379. [PMID: 31416910 PMCID: PMC6699408 DOI: 10.1101/lm.049023.118] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/08/2019] [Indexed: 01/04/2023]
Abstract
O-GlcNAcylation of serine/threonine residues on target proteins occurs dynamically in postmitotic neurons of the hippocampus and may serve to control both the stability and activity of target proteins. Remarkably, the addition and removal of the O-GlcNAc posttranslational modifications are catalyzed by a pair of enzymes, the O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). More than thousands of proteins are modified by O-GlcNAcylation including epigenetic modifying enzymes. A critical target of OGT is the polycomb repressive complex 2 (PRC2) containing the histone lysine methyltransferase EZH2 that mediates trimethylation of lysine 27 on histone H3 (H3K27me3). However, whether OGT and PRC2 activity in the hippocampus couple to regulate gene transcription mechanisms during memory consolidation remains unknown. Here, we found increases in OGT expression and global O-GlcNAcylation levels in dorsal area CA1 of the hippocampus during memory consolidation. Additionally, we observed that OGT exerts control over epigenetic regulation via EZH2-H3K27me3 during memory consolidation. Blocking O-GlcNAc signaling via RNAi within dorsal area CA1 led to the global and site-specific loss of activity-dependent epigenetic plasticity at genes regulated by H3K27me3 and impairment of hippocampus-dependent memory. Together, these findings illustrate a unique epigenetic role of OGT via regulation of histone methylation mediated by EZH2 during memory consolidation of fear conditioned memories.
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Affiliation(s)
- Anderson A Butler
- Department of Neurobiology, the University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Richard G Sanchez
- Department of Neurobiology, the University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Timothy J Jarome
- Department of Neurobiology, the University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - William M Webb
- Department of Neurobiology, the University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Farah D Lubin
- Department of Neurobiology, the University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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18
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Gu YX, Liang XX, Yin NY, Yang Y, Wan B, Guo LH, Faiola F. New insights into mechanism of bisphenol analogue neurotoxicity: implications of inhibition of O-GlcNAcase activity in PC12 cells. Arch Toxicol 2019; 93:2661-2671. [DOI: 10.1007/s00204-019-02525-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/18/2019] [Indexed: 01/25/2023]
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19
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Acutely elevated O-GlcNAcylation suppresses hippocampal activity by modulating both intrinsic and synaptic excitability factors. Sci Rep 2019; 9:7287. [PMID: 31086206 PMCID: PMC6514166 DOI: 10.1038/s41598-019-43017-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/05/2019] [Indexed: 12/13/2022] Open
Abstract
Post-translational modification (PTM) plays a critical role in increasing proteome complexity and diversifying protein functions. O-GlcNAc modification is a reversible, dynamic and highly abundant PTM catalyzed by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), regardless of substrates. The two enzymes are particularly enriched in the brain, and recent proteomic studies identified that a large number of neuron-specific proteins undergo O-GlcNAc modification. In addition, pathological conditions with aberrant O-GlcNAcylation such as diabetes and obesity are associated with the higher risk of cognitive decline and memory impairment. However, despite its prevalence in the brain, functional significance of O-GlcNAcylation in regulating neuronal properties remains unclear at the molecular level. Here, we report that an acute increase in O-GlcNAcylation induced by pharmacological inhibition of OGA significantly reduces the intrinsic excitability of hippocampal CA1 neurons through the cooperative modulation of multiple voltage-gated ion channels. Moreover, elevated O-GlcNAcylation also suppresses excitatory synaptic transmission at Schaffer collateral-CA1 synapses through the removal of GluA2-containing AMPA receptors from postsynaptic densities. Collectively, our findings demonstrate that a change in O-GlcNAcylation levels dynamically regulates hippocampal activity at both intrinsic and synaptic levels, providing a mechanistic link between dysregulated O-GlcNAcylation and hippocampal dysfunction.
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20
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Ding N, Peng P, Chu YJ, Wang JJ, Chen SY, Arulthas R, Deng YQ. The effects of O-GlcNAc alteration on Alzheimer-like neurodegeneration in SK-N-SH cells. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2018; 162:243-248. [DOI: 10.5507/bp.2018.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 07/17/2018] [Indexed: 11/23/2022] Open
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21
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Lagerlöf O. O-GlcNAc cycling in the developing, adult and geriatric brain. J Bioenerg Biomembr 2018; 50:241-261. [PMID: 29790000 PMCID: PMC5984647 DOI: 10.1007/s10863-018-9760-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 05/07/2018] [Indexed: 12/14/2022]
Abstract
Hundreds of proteins in the nervous system are modified by the monosaccharide O-GlcNAc. A single protein is often O-GlcNAcylated on several amino acids and the modification of a single site can play a crucial role for the function of the protein. Despite its complexity, only two enzymes add and remove O-GlcNAc from proteins, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Global and local regulation of these enzymes make it possible for O-GlcNAc to coordinate multiple cellular functions at the same time as regulating specific pathways independently from each other. If O-GlcNAcylation is disrupted, metabolic disorder or intellectual disability may ensue, depending on what neurons are affected. O-GlcNAc's promise as a clinical target for developing drugs against neurodegenerative diseases has been recognized for many years. Recent literature puts O-GlcNAc in the forefront among mechanisms that can help us better understand how neuronal circuits integrate diverse incoming stimuli such as fluctuations in nutrient supply, metabolic hormones, neuronal activity and cellular stress. Here the functions of O-GlcNAc in the nervous system are reviewed.
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Affiliation(s)
- Olof Lagerlöf
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden.
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22
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Ong Q, Han W, Yang X. O-GlcNAc as an Integrator of Signaling Pathways. Front Endocrinol (Lausanne) 2018; 9:599. [PMID: 30464755 PMCID: PMC6234912 DOI: 10.3389/fendo.2018.00599] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/20/2018] [Indexed: 12/03/2022] Open
Abstract
O-GlcNAcylation is an important posttranslational modification governed by a single pair of enzymes-O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). These two enzymes mediate the dynamic cycling of O-GlcNAcylation on a wide variety of cytosolic, nuclear and mitochondrial proteins in a nutrient- and stress-responsive fashion. While cellular functions of O-GlcNAcylation have been emerging, little is known regarding the precise mechanisms how the enzyme pair senses the environmental cues to elicit molecular and physiological changes. In this review, we discuss how the OGT/OGA pair acts as a metabolic sensor that integrates signaling pathways, given their capability of receiving signaling inputs from various partners, targeting multiple substrates with spatiotemporal specificity and translocating to different parts of the cell. We also discuss how the pair maintains homeostatic signaling within the cell and its physiological relevance. A better understanding of the mechanisms of OGT/OGA action would enable us to derive therapeutic benefits of resetting cellular O-GlcNAc levels within an optimal range.
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Affiliation(s)
- Qunxiang Ong
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, United States
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Xiaoyong Yang
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, United States
- Program in Integrative Cell Signaling and Neurobiology of Metabolism, Yale University School of Medicine, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States
- *Correspondence: Xiaoyong Yang
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23
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Hwang H, Rhim H. Functional significance of O-GlcNAc modification in regulating neuronal properties. Pharmacol Res 2017; 129:295-307. [PMID: 29223644 DOI: 10.1016/j.phrs.2017.12.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/17/2017] [Accepted: 12/04/2017] [Indexed: 12/22/2022]
Abstract
Post-translational modifications (PTMs) covalently modify proteins and diversify protein functions. Along with protein phosphorylation, another common PTM is the addition of O-linked β-N-acetylglucosamine (O-GlcNAc) to serine and/or threonine residues. O-GlcNAc modification is similar to phosphorylation in that it occurs to serine and threonine residues and cycles on and off with a similar time scale. However, a striking difference is that the addition and removal of the O-GlcNAc moiety on all substrates are mediated by the two enzymes regardless of proteins, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. O-GlcNAcylation can interact or potentially compete with phosphorylation on serine and threonine residues, and thus serves as an important molecular mechanism to modulate protein functions and activation. However, it has been challenging to address the role of O-GlcNAc modification in regulating protein functions at the molecular level due to the lack of convenient tools to determine the sites and degrees of O-GlcNAcylation. Studies in this field have only begun to expand significantly thanks to the recent advances in detection and manipulation methods such as quantitative proteomics and highly selective small-molecule inhibitors for OGT and OGA. Interestingly, multiple brain regions, especially hippocampus, express high levels of both OGT and OGA, and a number of neuron-specific proteins have been reported to undergo O-GlcNAcylation. This review aims to discuss the recent updates concerning the impacts of O-GlcNAc modification on neuronal functions at multiple levels ranging from intrinsic neuronal properties to synaptic plasticity and animal behaviors.
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Affiliation(s)
- Hongik Hwang
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Hyewhon Rhim
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea.
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24
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Ma X, Li H, He Y, Hao J. The emerging link between O-GlcNAcylation and neurological disorders. Cell Mol Life Sci 2017; 74:3667-3686. [PMID: 28534084 PMCID: PMC11107615 DOI: 10.1007/s00018-017-2542-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 04/23/2017] [Accepted: 05/16/2017] [Indexed: 12/15/2022]
Abstract
O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) is involved in the regulation of many cellular cascades and neurological diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. In the brain, the expression of O-GlcNAcylation is notably heightened, as is that of O-linked N-acetylglucosaminyltransferase (OGT) and β-N-acetylglucosaminidase (OGA), the presence of which is prominent in many regions of neurological importance. Most importantly, O-GlcNAcylation is believed to contribute to the normal functioning of neurons; conversely, its dysregulation participates in the pathogenesis of neurological disorders. In neurodegenerative diseases, O-GlcNAcylation of the brain's key proteins, such as tau and amyloid-β, interacts with their phosphorylation, thereby triggering the formation of neurofibrillary tangles and amyloid plaques. An increase of O-GlcNAcylation by pharmacological intervention prevents neuronal loss. Additionally, O-GlcNAcylation is stress sensitive, and its elevation is cytoprotective. Increased O-GlcNAcylation ameliorated brain damage in victims of both trauma-hemorrhage and stroke. In this review, we summarize the current understanding of O-GlcNAcylation's physiological and pathological roles in the nervous system and provide a foundation for development of a therapeutic strategy for neurological disorders.
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Affiliation(s)
- Xiaofeng Ma
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - He Li
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Yating He
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Junwei Hao
- Department of Neurology and Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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Acute Increases in Protein O-GlcNAcylation Dampen Epileptiform Activity in Hippocampus. J Neurosci 2017; 37:8207-8215. [PMID: 28760863 DOI: 10.1523/jneurosci.0173-16.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 07/02/2017] [Accepted: 07/08/2017] [Indexed: 11/21/2022] Open
Abstract
O-GlcNAcylation is a ubiquitous and dynamic post-translational modification involving the O-linkage of β-N-acetylglucosamine to serine/threonine residues of membrane, cytosolic, and nuclear proteins. This modification is similar to phosphorylation and regarded as a key regulator of cell survival and homeostasis. Previous studies have shown that phosphorylation of serine residues on synaptic proteins is a major regulator of synaptic strength and long-term plasticity, suggesting that O-GlcNAcylation of synaptic proteins is likely as important as phosphorylation; however, few studies have investigated its role in synaptic efficacy. We recently demonstrated that acutely increasing O-GlcNAcylation induces a novel form of LTD at CA3-CA1 synapses, O-GlcNAc LTD. Here, using hippocampal slices from young adult male rats and mice, we report that epileptiform activity at CA3-CA1 synapses, generated by GABAAR inhibition, is significantly attenuated when protein O-GlcNAcylation is pharmacologically increased. This dampening effect is lost in slices from GluA2 KO mice, indicating a requirement of GluA2-containing AMPARs, similar to expression of O-GlcNAc LTD. Furthermore, we find that increasing O-GlcNAcylation decreases spontaneous CA3 pyramidal cell activity under basal and hyperexcitable conditions. This dampening effect was also observed on cortical hyperexcitability during in vivo EEG recordings in awake mice where the effects of the proconvulsant pentylenetetrazole are attenuated by acutely increasing O-GlcNAcylation. Collectively, these data demonstrate that the post-translational modification, O-GlcNAcylation, is a novel mechanism by which neuronal and synaptic excitability can be regulated, and suggest the possibility that increasing O-GlcNAcylation could be a novel therapeutic target to treat seizure disorders and epilepsy.SIGNIFICANCE STATEMENT We recently reported that an acute pharmacological increase in protein O-GlcNAcylation induces a novel form of long-term synaptic depression at hippocampal CA3-CA1 synapses (O-GlcNAc LTD). This synaptic dampening effect on glutamatergic networks suggests that increasing O-GlcNAcylation will depress pathological hyperexcitability. Using in vitro and in vivo models of epileptiform activity, we show that acutely increasing O-GlcNAc levels can significantly attenuate ongoing epileptiform activity and prophylactically dampen subsequent seizure activity. Together, our findings support the conclusion that protein O-GlcNAcylation is a regulator of neuronal excitability, and it represents a promising target for further research on seizure disorder therapeutics.
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