1
|
Ng XY, Cao M. Dysfunction of synaptic endocytic trafficking in Parkinson's disease. Neural Regen Res 2024; 19:2649-2660. [PMID: 38595283 PMCID: PMC11168511 DOI: 10.4103/nrr.nrr-d-23-01624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/12/2023] [Accepted: 01/03/2024] [Indexed: 04/11/2024] Open
Abstract
Parkinson's disease is characterized by the selective degeneration of dopamine neurons in the nigrostriatal pathway and dopamine deficiency in the striatum. The precise reasons behind the specific degeneration of these dopamine neurons remain largely elusive. Genetic investigations have identified over 20 causative PARK genes and 90 genomic risk loci associated with both familial and sporadic Parkinson's disease. Notably, several of these genes are linked to the synaptic vesicle recycling process, particularly the clathrin-mediated endocytosis pathway. This suggests that impaired synaptic vesicle recycling might represent an early feature of Parkinson's disease, followed by axonal degeneration and the eventual loss of dopamine cell bodies in the midbrain via a "dying back" mechanism. Recently, several new animal and cellular models with Parkinson's disease-linked mutations affecting the endocytic pathway have been created and extensively characterized. These models faithfully recapitulate certain Parkinson's disease-like features at the animal, circuit, and cellular levels, and exhibit defects in synaptic membrane trafficking, further supporting the findings from human genetics and clinical studies. In this review, we will first summarize the cellular and molecular findings from the models of two Parkinson's disease-linked clathrin uncoating proteins: auxilin (DNAJC6/PARK19) and synaptojanin 1 (SYNJ1/PARK20). The mouse models carrying these two PARK gene mutations phenocopy each other with specific dopamine terminal pathology and display a potent synergistic effect. Subsequently, we will delve into the involvement of several clathrin-mediated endocytosis-related proteins (GAK, endophilin A1, SAC2/INPP5F, synaptotagmin-11), identified as Parkinson's disease risk factors through genome-wide association studies, in Parkinson's disease pathogenesis. We will also explore the direct or indirect roles of some common Parkinson's disease-linked proteins (alpha-synuclein (PARK1/4), Parkin (PARK2), and LRRK2 (PARK8)) in synaptic endocytic trafficking. Additionally, we will discuss the emerging novel functions of these endocytic proteins in downstream membrane traffic pathways, particularly autophagy. Given that synaptic dysfunction is considered as an early event in Parkinson's disease, a deeper understanding of the cellular mechanisms underlying synaptic vesicle endocytic trafficking may unveil novel targets for early diagnosis and the development of interventional therapies for Parkinson's disease. Future research should aim to elucidate why generalized synaptic endocytic dysfunction leads to the selective degeneration of nigrostriatal dopamine neurons in Parkinson's disease.
Collapse
Affiliation(s)
- Xin Yi Ng
- Programme in Neuroscience and Behavioural Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Mian Cao
- Programme in Neuroscience and Behavioural Disorders, Duke-NUS Medical School, Singapore, Singapore
- Department of Physiology, National University of Singapore, Singapore, Singapore
| |
Collapse
|
2
|
McCormick LE, Evans EB, Barker NK, Herring LE, Diering GH, Gupton SL. The E3 ubiquitin ligase TRIM9 regulates synaptic function and actin dynamics in response to netrin-1. Mol Biol Cell 2024; 35:ar67. [PMID: 38507236 PMCID: PMC11151106 DOI: 10.1091/mbc.e23-12-0476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/04/2024] [Accepted: 03/13/2024] [Indexed: 03/22/2024] Open
Abstract
During neuronal development, dynamic filopodia emerge from dendrites and mature into functional dendritic spines during synaptogenesis. Dendritic filopodia and spines respond to extracellular cues, influencing dendritic spine shape and size as well as synaptic function. Previously, the E3 ubiquitin ligase TRIM9 was shown to regulate filopodia in early stages of neuronal development, including netrin-1-dependent axon guidance and branching. Here, we demonstrate that TRIM9 also localizes to dendritic filopodia and spines of murine cortical and hippocampal neurons during synaptogenesis and is required for synaptic responses to netrin. In particular, TRIM9 is enriched in the postsynaptic density (PSD) within dendritic spines and loss of Trim9 alters the PSD proteome, including the actin cytoskeleton landscape. While netrin exposure induces accumulation of the Arp2/3 complex and filamentous actin in dendritic spine heads, this response is disrupted by genetic deletion of Trim9. In addition, we document changes in the synaptic receptors associated with loss of Trim9. These defects converge on a loss of netrin-dependent increases in neuronal firing rates, indicating TRIM9 is required downstream of synaptic netrin-1 signaling. We propose that TRIM9 regulates cytoskeletal dynamics in dendritic spines and is required for the proper response to synaptic stimuli.
Collapse
Affiliation(s)
- Laura E. McCormick
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Elliot B. Evans
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Natalie K. Barker
- Hooker Proteomics Core, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Laura E. Herring
- Hooker Proteomics Core, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Graham H. Diering
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Stephanie L. Gupton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| |
Collapse
|
3
|
Blondiaux A, Jia S, Annamneedi A, Çalışkan G, Nebel J, Montenegro-Venegas C, Wykes RC, Fejtova A, Walker MC, Stork O, Gundelfinger ED, Dityatev A, Seidenbecher CI. Linking epileptic phenotypes and neural extracellular matrix remodeling signatures in mouse models of epilepsy. Neurobiol Dis 2023; 188:106324. [PMID: 37838005 DOI: 10.1016/j.nbd.2023.106324] [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: 05/26/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/16/2023] Open
Abstract
Epilepsies are multifaceted neurological disorders characterized by abnormal brain activity, e.g. caused by imbalanced synaptic excitation and inhibition. The neural extracellular matrix (ECM) is dynamically modulated by physiological and pathophysiological activity and critically involved in controlling the brain's excitability. We used different epilepsy models, i.e. mice lacking the presynaptic scaffolding protein Bassoon at excitatory, inhibitory or all synapse types as genetic models for rapidly generalizing early-onset epilepsy, and intra-hippocampal kainate injection, a model for acquired temporal lobe epilepsy, to study the relationship between epileptic seizures and ECM composition. Electroencephalogram recordings revealed Bassoon deletion at excitatory or inhibitory synapses having diverse effects on epilepsy-related phenotypes. While constitutive Bsn mutants and to a lesser extent GABAergic neuron-specific knockouts (BsnDlx5/6cKO) displayed severe epilepsy with more and stronger seizures than kainate-injected animals, mutants lacking Bassoon solely in excitatory forebrain neurons (BsnEmx1cKO) showed only mild impairments. By semiquantitative immunoblotting and immunohistochemistry we show model-specific patterns of neural ECM remodeling, and we also demonstrate significant upregulation of the ECM receptor CD44 in null and BsnDlx5/6cKO mutants. ECM-associated WFA-binding chondroitin sulfates were strongly augmented in seizure models. Strikingly, Brevican, Neurocan, Aggrecan and link proteins Hapln1 and Hapln4 levels reliably predicted seizure properties across models, suggesting a link between ECM state and epileptic phenotype.
Collapse
Affiliation(s)
| | - Shaobo Jia
- German Center for Neurodegenerative Diseases, Site Magdeburg (DZNE), Magdeburg, Germany
| | - Anil Annamneedi
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany; Institute of Biology, Otto-Von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany
| | - Gürsel Çalışkan
- Institute of Biology, Otto-Von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany
| | - Jana Nebel
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
| | - Carolina Montenegro-Venegas
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany; Institute for Pharmacology and Toxicology, Otto von Guericke University, Magdeburg, Germany
| | - Robert C Wykes
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK; Nanomedicine Lab & Geoffrey Jefferson Brain Research Center, University of Manchester, Manchester M13 9PT, UK
| | - Anna Fejtova
- Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Oliver Stork
- Institute of Biology, Otto-Von-Guericke University, Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany
| | - Eckart D Gundelfinger
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany; Institute for Pharmacology and Toxicology, Otto von Guericke University, Magdeburg, Germany.
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases, Site Magdeburg (DZNE), Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany; Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany.
| | - Constanze I Seidenbecher
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg 39120, Germany.
| |
Collapse
|
4
|
Hsu YL, Chen HJ, Gao JX, Yang MY, Fu RH. Chiisanoside Mediates the Parkin/ZNF746/PGC-1α Axis by Downregulating MiR-181a to Improve Mitochondrial Biogenesis in 6-OHDA-Caused Neurotoxicity Models In Vitro and In Vivo: Suggestions for Prevention of Parkinson's Disease. Antioxidants (Basel) 2023; 12:1782. [PMID: 37760085 PMCID: PMC10525196 DOI: 10.3390/antiox12091782] [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: 08/11/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
The degeneration of dopamine (DA) neurons is known to be associated with defects in mitochondrial biogenesis caused by aging, environmental factors, or mutations in genes, leading to Parkinson's disease (PD). As PD has not yet been successfully cured, the strategy of using small molecule drugs to protect and restore mitochondrial biogenesis is a promising direction. This study evaluated the efficacy of synthetic chiisanoside (CSS) identified in the leaves of Acanthopanax sessiliflorus to prevent PD symptoms. The results show that in the 6-hydroxydopamine (6-OHDA) model, CSS pretreatment can effectively alleviate the reactive oxygen species generation and apoptosis of SH-SY5Y cells, thereby lessening the defects in the C. elegans model including DA neuron degeneration, dopamine-mediated food sensitivity behavioral disorders, and shortened lifespan. Mechanistically, we found that CSS could restore the expression of proliferator-activated receptor gamma coactivator-1-alpha (PGC-1α), a key molecule in mitochondrial biogenesis, and its downstream related genes inhibited by 6-OHDA. We further confirmed that this is due to the enhanced activity of parkin leading to the ubiquitination and degradation of PGC-1α inhibitor protein Zinc finger protein 746 (ZNF746). Parkin siRNA treatment abolished this effect of CSS. Furthermore, we found that CSS inhibited 6-OHDA-induced expression of miR-181a, which targets parkin. The CSS's ability to reverse the 6-OHDA-induced reduction in mitochondrial biogenesis and activation of apoptosis was abolished after the transfection of anti-miR-181a and miR-181a mimics. Therefore, the neuroprotective effect of CSS mainly promotes mitochondrial biogenesis by regulating the miR-181a/Parkin/ZNF746/PGC-1α axis. CSS potentially has the opportunity to be developed into PD prevention agents.
Collapse
Affiliation(s)
- Yu-Ling Hsu
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan; (Y.-L.H.); (H.-J.C.); (J.-X.G.)
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan
| | - Hui-Jye Chen
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan; (Y.-L.H.); (H.-J.C.); (J.-X.G.)
| | - Jia-Xin Gao
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan; (Y.-L.H.); (H.-J.C.); (J.-X.G.)
| | - Ming-Yang Yang
- Ph.D. Program for Aging, China Medical University, Taichung 40402, Taiwan;
| | - Ru-Huei Fu
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan; (Y.-L.H.); (H.-J.C.); (J.-X.G.)
- Ph.D. Program for Aging, China Medical University, Taichung 40402, Taiwan;
- Translational Medicine Research Center, China Medical University Hospital, Taichung 40447, Taiwan
| |
Collapse
|
5
|
Naia L, Shimozawa M, Bereczki E, Li X, Liu J, Jiang R, Giraud R, Leal NS, Pinho CM, Berger E, Falk VL, Dentoni G, Ankarcrona M, Nilsson P. Mitochondrial hypermetabolism precedes impaired autophagy and synaptic disorganization in App knock-in Alzheimer mouse models. Mol Psychiatry 2023; 28:3966-3981. [PMID: 37907591 PMCID: PMC10730401 DOI: 10.1038/s41380-023-02289-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 09/05/2023] [Accepted: 10/03/2023] [Indexed: 11/02/2023]
Abstract
Accumulation of amyloid β-peptide (Aβ) is a driver of Alzheimer's disease (AD). Amyloid precursor protein (App) knock-in mouse models recapitulate AD-associated Aβ pathology, allowing elucidation of downstream effects of Aβ accumulation and their temporal appearance upon disease progression. Here we have investigated the sequential onset of AD-like pathologies in AppNL-F and AppNL-G-F knock-in mice by time-course transcriptome analysis of hippocampus, a region severely affected in AD. Strikingly, energy metabolism emerged as one of the most significantly altered pathways already at an early stage of pathology. Functional experiments in isolated mitochondria from hippocampus of both AppNL-F and AppNL-G-F mice confirmed an upregulation of oxidative phosphorylation driven by the activity of mitochondrial complexes I, IV and V, associated with higher susceptibility to oxidative damage and Ca2+-overload. Upon increasing pathologies, the brain shifts to a state of hypometabolism with reduced abundancy of mitochondria in presynaptic terminals. These late-stage mice also displayed enlarged presynaptic areas associated with abnormal accumulation of synaptic vesicles and autophagosomes, the latter ultimately leading to local autophagy impairment in the synapses. In summary, we report that Aβ-induced pathways in App knock-in mouse models recapitulate key pathologies observed in AD brain, and our data herein adds a comprehensive understanding of the pathologies including dysregulated metabolism and synapses and their timewise appearance to find new therapeutic approaches for AD.
Collapse
Affiliation(s)
- Luana Naia
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Makoto Shimozawa
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Erika Bereczki
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Centre for Translational Microbiome Research and National Pandemic Center, Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Xidan Li
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Jianping Liu
- Department of Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Richeng Jiang
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Department of Otolaryngology Head and Neck Surgery, The First Hospital of Jilin University, Changchun, China
| | - Romain Giraud
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Nuno Santos Leal
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Catarina Moreira Pinho
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Erik Berger
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Victoria Lim Falk
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Giacomo Dentoni
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Maria Ankarcrona
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.
| | - Per Nilsson
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
6
|
Garner CC, Ackermann F. Synaptic logistics: The presynaptic scaffold protein Piccolo a nodal point tuning synaptic vesicle recycling, maintenance and integrity. Mol Cell Neurosci 2023; 124:103795. [PMID: 36436725 DOI: 10.1016/j.mcn.2022.103795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
Properly working synapses are one important guarantor for a functional and healthy brain. They are small, densely packed structures, where information is transmitted through the release of neurotransmitters from synaptic vesicles (SVs). The latter cycle within the presynaptic terminal as they first fuse with the plasma membrane to deliver their neurotransmitter, and afterwards become recycled and prepared for a new release event. The synapse is an autonomous structure functioning mostly independent of the neuronal soma. Dysfunction in synaptic processes associated with local insults or genetic abnormalities can directly compromise synapse function and integrity and subsequently lead to the onset of neurodegenerative diseases. Therefore, measures need to be in place counteracting these threats for instance through the continuous replacement of old and damaged SV proteins. Interestingly recent studies show that the presynaptic scaffolding protein Piccolo contributes to health, function and integrity of synapses, as it mediates the delivery of synaptic proteins from the trans-Golgi network (TGN) towards synapses, as well as the local recycling and turnover of SV proteins within synaptic terminals. It can fulfill these various tasks through its multi-domain structure and ability to interact with numerous binding partners. In addition, Piccolo has recently been linked with the early onset neurodegenerative disease Pontocerebellar Hypoplasia Type 3 (PCH3) further underlying its importance for neuronal health. In this review, we will focus on Piccolo's contributions to synapse function, health and integrity and make a connection how those may contribute to the disease pattern of PCH3.
Collapse
Affiliation(s)
- Craig C Garner
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany; NeuroCure Cluster of Excellence, Charité Universitätsmedizin Berlin, Germany
| | - Frauke Ackermann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.
| |
Collapse
|
7
|
Watson ET, Pauers MM, Seibert MJ, Vevea JD, Chapman ER. Synaptic vesicle proteins are selectively delivered to axons in mammalian neurons. eLife 2023; 12:e82568. [PMID: 36729040 PMCID: PMC9894587 DOI: 10.7554/elife.82568] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 01/11/2023] [Indexed: 02/03/2023] Open
Abstract
Neurotransmitter-filled synaptic vesicles (SVs) mediate synaptic transmission and are a hallmark specialization in neuronal axons. Yet, how SV proteins are sorted to presynaptic nerve terminals remains the subject of debate. The leading model posits that these proteins are randomly trafficked throughout neurons and are selectively retained in presynaptic boutons. Here, we used the RUSH (retention using selective hooks) system, in conjunction with HaloTag labeling approaches, to study the egress of two distinct transmembrane SV proteins, synaptotagmin 1 and synaptobrevin 2, from the soma of mature cultured rat and mouse neurons. For these studies, the SV reporter constructs were expressed at carefully controlled, very low levels. In sharp contrast to the selective retention model, both proteins selectively and specifically entered axons with minimal entry into dendrites. However, even moderate overexpression resulted in the spillover of SV proteins into dendrites, potentially explaining the origin of previous non-polarized transport models, revealing the limited, saturable nature of the direct axonal trafficking pathway. Moreover, we observed that SV constituents were first delivered to the presynaptic plasma membrane before incorporation into SVs. These experiments reveal a new-found membrane trafficking pathway, for SV proteins, in classically polarized mammalian neurons and provide a glimpse at the first steps of SV biogenesis.
Collapse
Affiliation(s)
- Emma T Watson
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Michaela M Pauers
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Michael J Seibert
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Jason D Vevea
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| | - Edwin R Chapman
- Department of Neuroscience, University of Wisconsin-MadisonMadisonUnited States
- Howard Hughes Medical InstituteMadisonUnited States
| |
Collapse
|
8
|
Kisaretova P, Tsybko A, Bondar N, Reshetnikov V. Molecular Abnormalities in BTBR Mice and Their Relevance to Schizophrenia and Autism Spectrum Disorders: An Overview of Transcriptomic and Proteomic Studies. Biomedicines 2023; 11:biomedicines11020289. [PMID: 36830826 PMCID: PMC9953015 DOI: 10.3390/biomedicines11020289] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/22/2023] Open
Abstract
Animal models of psychopathologies are of exceptional interest for neurobiologists because these models allow us to clarify molecular mechanisms underlying the pathologies. One such model is the inbred BTBR strain of mice, which is characterized by behavioral, neuroanatomical, and physiological hallmarks of schizophrenia (SCZ) and autism spectrum disorders (ASDs). Despite the active use of BTBR mice as a model object, the understanding of the molecular features of this strain that cause the observed behavioral phenotype remains insufficient. Here, we analyzed recently published data from independent transcriptomic and proteomic studies on hippocampal and corticostriatal samples from BTBR mice to search for the most consistent aberrations in gene or protein expression. Next, we compared reproducible molecular signatures of BTBR mice with data on postmortem samples from ASD and SCZ patients. Taken together, these data helped us to elucidate brain-region-specific molecular abnormalities in BTBR mice as well as their relevance to the anomalies seen in ASDs or SCZ in humans.
Collapse
Affiliation(s)
- Polina Kisaretova
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Anton Tsybko
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
| | - Natalia Bondar
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
| | - Vasiliy Reshetnikov
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Prospekt Akad. Lavrentyeva 10, Novosibirsk 630090, Russia
- Department of Biotechnology, Sirius University of Science and Technology, 1 Olympic Avenue, Sochi 354340, Russia
- Correspondence:
| |
Collapse
|
9
|
Sidibe DK, Kulkarni VV, Dong A, Herr JB, Vogel MC, Stempel MH, Maday S. Brain-derived neurotrophic factor stimulates the retrograde pathway for axonal autophagy. J Biol Chem 2022; 298:102673. [PMID: 36336077 PMCID: PMC9768381 DOI: 10.1016/j.jbc.2022.102673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 10/27/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Autophagy is a lysosomal degradation pathway important for neuronal development, function, and survival. How autophagy in axons is regulated by neurotrophins to impact neuronal viability and function is poorly understood. Here, we use live-cell imaging in primary neurons to investigate the regulation of axonal autophagy by the neurotrophin brain-derived neurotrophic factor (BDNF) and elucidate whether autophagosomes carry BDNF-mediated signaling information. We find that BDNF induces autophagic flux in primary neurons by stimulating the retrograde pathway for autophagy in axons. We observed an increase in autophagosome density and retrograde flux in axons, and a corresponding increase in autophagosome density in the soma. However, we find little evidence of autophagosomes comigrating with BDNF. In contrast, BDNF effectively engages its cognate receptor TrkB to undergo retrograde transport in the axon. These compartments, however, are distinct from LC3-positive autophagic organelles in the axon. Together, we find that BDNF stimulates autophagy in the axon, but retrograde autophagosomes do not appear to carry BDNF cargo. Thus, autophagosomes likely do not play a major role in relaying neurotrophic signaling information across the axon in the form of active BDNF/TrkB complexes. Rather, BDNF likely stimulates autophagy as a consequence of BDNF-induced processes that require canonical roles for autophagy in degradation.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| |
Collapse
|
10
|
Overhoff M, Tellkamp F, Hess S, Tolve M, Tutas J, Faerfers M, Ickert L, Mohammadi M, De Bruyckere E, Kallergi E, Delle Vedove A, Nikoletopoulou V, Wirth B, Isensee J, Hucho T, Puchkov D, Isbrandt D, Krueger M, Kloppenburg P, Kononenko NL. Autophagy regulates neuronal excitability by controlling cAMP/protein kinase A signaling at the synapse. EMBO J 2022; 41:e110963. [PMID: 36217825 PMCID: PMC9670194 DOI: 10.15252/embj.2022110963] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 09/10/2022] [Accepted: 09/14/2022] [Indexed: 01/13/2023] Open
Abstract
Autophagy provides nutrients during starvation and eliminates detrimental cellular components. However, accumulating evidence indicates that autophagy is not merely a housekeeping process. Here, by combining mouse models of neuron-specific ATG5 deficiency in either excitatory or inhibitory neurons with quantitative proteomics, high-content microscopy, and live-imaging approaches, we show that autophagy protein ATG5 functions in neurons to regulate cAMP-dependent protein kinase A (PKA)-mediated phosphorylation of a synapse-confined proteome. This function of ATG5 is independent of bulk turnover of synaptic proteins and requires the targeting of PKA inhibitory R1 subunits to autophagosomes. Neuronal loss of ATG5 causes synaptic accumulation of PKA-R1, which sequesters the PKA catalytic subunit and diminishes cAMP/PKA-dependent phosphorylation of postsynaptic cytoskeletal proteins that mediate AMPAR trafficking. Furthermore, ATG5 deletion in glutamatergic neurons augments AMPAR-dependent excitatory neurotransmission and causes the appearance of spontaneous recurrent seizures in mice. Our findings identify a novel role of autophagy in regulating PKA signaling at glutamatergic synapses and suggest the PKA as a target for restoration of synaptic function in neurodegenerative conditions with autophagy dysfunction.
Collapse
Affiliation(s)
- Melina Overhoff
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Frederik Tellkamp
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of GeneticsUniversity of CologneCologneGermany
| | - Simon Hess
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of ZoologyUniversity of CologneCologneGermany
| | - Marianna Tolve
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Center for Physiology and Pathophysiology, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Janine Tutas
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Marcel Faerfers
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Lotte Ickert
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Center for Physiology and Pathophysiology, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Milad Mohammadi
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Elodie De Bruyckere
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Emmanouela Kallergi
- Département des Neurosciences FondamentalesUniversity of LausanneLausanneSwitzerland
| | - Andrea Delle Vedove
- Institute of Human Genetics, Center for Molecular Medicine Cologne, Center for Rare Diseases Cologne, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | | | - Brunhilde Wirth
- Faculty of Mathematics and Natural Sciences, Institute of GeneticsUniversity of CologneCologneGermany,Institute of Human Genetics, Center for Molecular Medicine Cologne, Center for Rare Diseases Cologne, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Joerg Isensee
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Tim Hucho
- Translational Pain Research, Department of Anaesthesiology and Intensive Care Medicine, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| | - Dmytro Puchkov
- Leibniz Institute for Molecular Pharmacology (FMP)BerlinGermany
| | - Dirk Isbrandt
- Institute for Molecular and Behavioral Neuroscience, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany,Experimental NeurophysiologyGerman Center for Neurodegenerative DiseasesBonnGermany
| | - Marcus Krueger
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of GeneticsUniversity of CologneCologneGermany
| | - Peter Kloppenburg
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Faculty of Mathematics and Natural Sciences, Institute of ZoologyUniversity of CologneCologneGermany
| | - Natalia L Kononenko
- Cologne Excellence Cluster Cellular Stress Response in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany,Center for Physiology and Pathophysiology, Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany
| |
Collapse
|
11
|
Ferroportin-dependent ferroptosis induced by ellagic acid retards liver fibrosis by impairing the SNARE complexes formation. Redox Biol 2022; 56:102435. [PMID: 36029649 PMCID: PMC9425030 DOI: 10.1016/j.redox.2022.102435] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/06/2022] [Accepted: 08/07/2022] [Indexed: 02/08/2023] Open
Abstract
Chronic liver injury causing liver fibrosis is a major cause of morbidity and mortality worldwide. Targeting the suppression of hepatic stellate cell (HSC) activation is recognized as an effective strategy for the treatment of liver fibrosis. Ellagic acid (EA), a natural polyphenol product isolated from fruits and vegetables, possesses many biological functions. Here, EA exerts its antifibrotic activity by inducing ferroptotic cell death of activated HSCs, which is accompanied by redox-active iron accumulation, lipid peroxidation, and GSH depletion in CCl4 mice and human LX-2 cells. The specific ferroptosis inhibitor ferrostatin-1 prevented EA-induced ferroptotic cell death. Mechanistically, EA impairs the formation of vesicle-associated membrane protein 2 (VAMP2)/syntaxin 4 and VAMP2/synaptosome-associated protein 23 complexes by suppressing VAMP2 expression by enhancing its degradation in a proteasome-dependent pathway. This leads to the impairment of ferroportin (FPN, an iron exporter) translocation and intracellular iron extrusion. Interestingly, VAMP2 overexpression inhibits the role of EA in blocking FPN translocation and increasing intracellular ferritin content (an iron storage marker). In contrast, VAMP2 knockdown shows a synergistic effect on EA-mediated ferroptotic events in both HSCs. Additionally, HSC-specific overexpression of VAMP2 impaired EA-induced HSC ferroptosis in mouse liver fibrosis, and HSC-specific VAMP2 knockdown increased the inhibitory effect of EA on fibrosis. Taken together, our data suggest that the natural product EA exerts its antifibrotic effects by inducing FPN-dependent ferroptosis of HSCs by disrupting the formation of SNARE complexes, and EA will hopefully serve as a prospective compound for liver fibrosis treatment. EA exerts its antifibrotic activity by inducing ferroptotic cell death of activated HSCs in CCl4/BDL mice. EA blocks the SNARE complexes formation by suppressing VAMP2by enhancing its degradation in a proteasome-dependent pathway. Impairment SNARE complexes suppress FPN translocation, which in turn prevents intracellular iron extrusion. EA induces ferroptosis of HSCs resulting from intracellular excessive iron accumulation.
Collapse
|
12
|
Distribution and Localization of Mahogunin Ring Finger 1 in the Mouse Central Nervous System. Int J Mol Sci 2022; 23:ijms23168956. [PMID: 36012221 PMCID: PMC9408835 DOI: 10.3390/ijms23168956] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/05/2022] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
Mahogunin ring finger 1 (MGRN1), an E3 ubiquitin, is involved in several physiological and neuropathological processes. Although mgrn1 mRNA is widely distributed in the central nervous system (CNS), detailed information on its cellular and subcellular localization is lacking and its physiological role remains unclear. In this study, we aimed to determine the distribution of MGRN1 in the mouse CNS using a newly produced antibody against MGRN1. We found that the MGRN1 protein was expressed in most neuronal cell bodies. An intense MGRN1 expression was also observed in the neuropil of the gray matter in different regions of the CNS, including the main olfactory bulb, cerebral cortex, caudate, putamen, thalamic nuclei, hypothalamic nuclei, medial eminence, superior colliculus, hippocampus, dentate gyrus, and spinal cord. Contrastingly, no MGRN1 expression was observed in glial cells. Double fluorescence and immunoelectron microscopic analyses revealed the intracellular distribution of MGRN1 in pre-synapses and near the outer membrane of the mitochondria in neurons. These findings indicate that MGRN1 is more widely expressed throughout the CNS; additionally, the intracellular expression of MGRN1 suggests that it may play an important role in synaptic and mitochondrial functions.
Collapse
|
13
|
Montenegro‐Venegas C, Guhathakurta D, Pina‐Fernandez E, Andres‐Alonso M, Plattner F, Gundelfinger ED, Fejtova A. Bassoon controls synaptic vesicle release via regulation of presynaptic phosphorylation and
cAMP. EMBO Rep 2022; 23:e53659. [PMID: 35766170 PMCID: PMC9346490 DOI: 10.15252/embr.202153659] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 05/23/2022] [Accepted: 06/01/2022] [Indexed: 11/11/2022] Open
Abstract
Neuronal presynaptic terminals contain hundreds of neurotransmitter‐filled synaptic vesicles (SVs). The morphologically uniform SVs differ in their release competence segregating into functional pools that differentially contribute to neurotransmission. The presynaptic scaffold bassoon is required for neurotransmission, but the underlying molecular mechanisms are unknown. We report that glutamatergic synapses lacking bassoon feature decreased SV release competence and increased resting pool of SVs as assessed by imaging of SV release in cultured neurons. CDK5/calcineurin and cAMP/PKA presynaptic signalling are dysregulated, resulting in an aberrant phosphorylation of their downstream effectors synapsin1 and SNAP25, well‐known regulators of SV release competence. An acute pharmacological restoration of physiological CDK5 and cAMP/PKA activity fully normalises the SV pools in neurons lacking bassoon. Finally, we demonstrate that CDK5‐dependent regulation of PDE4 activity interacts with cAMP/PKA signalling and thereby controls SV release competence. These data reveal that bassoon organises SV pools in glutamatergic synapses via regulation of presynaptic phosphorylation and cAMP homeostasis and indicate a role of CDK5/PDE4/cAMP axis in the control of neurotransmitter release.
Collapse
Affiliation(s)
- Carolina Montenegro‐Venegas
- Department of Neurochemistry and Molecular Biology Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences (CBBS) Magdeburg Germany
- Institute for Pharmacology and Toxicology, Medical Faculty Otto von Guericke University Magdeburg Germany
| | - Debarpan Guhathakurta
- Molecular Psychiatry, Department of Psychiatry and Psychotherapy Universitätsklinikum Erlangen, Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Erlangen Germany
| | | | - Maria Andres‐Alonso
- RG Presynaptic Plasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | | | - Eckart D Gundelfinger
- Department of Neurochemistry and Molecular Biology Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences (CBBS) Magdeburg Germany
- Institute for Pharmacology and Toxicology, Medical Faculty Otto von Guericke University Magdeburg Germany
| | - Anna Fejtova
- Department of Neurochemistry and Molecular Biology Leibniz Institute for Neurobiology Magdeburg Germany
- Molecular Psychiatry, Department of Psychiatry and Psychotherapy Universitätsklinikum Erlangen, Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Erlangen Germany
- RG Presynaptic Plasticity Leibniz Institute for Neurobiology Magdeburg Germany
| |
Collapse
|
14
|
Sidibe DK, Vogel MC, Maday S. Organization of the autophagy pathway in neurons. Curr Opin Neurobiol 2022; 75:102554. [PMID: 35649324 PMCID: PMC9990471 DOI: 10.1016/j.conb.2022.102554] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/28/2022] [Accepted: 04/12/2022] [Indexed: 01/18/2023]
Abstract
Macroautophagy (hereafter referred to as autophagy) is an essential quality-control pathway in neurons, which face unique functional and morphological challenges in maintaining the integrity of organelles and the proteome. To overcome these challenges, neurons have developed compartment-specific pathways for autophagy. In this review, we discuss the organization of the autophagy pathway, from autophagosome biogenesis, trafficking, to clearance, in the neuron. We dissect the compartment-specific mechanisms and functions of autophagy in axons, dendrites, and the soma. Furthermore, we highlight examples of how steps along the autophagy pathway are impaired in the context of aging and neurodegenerative disease, which underscore the critical importance of autophagy in maintaining neuronal function and survival.
Collapse
Affiliation(s)
- David K Sidibe
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Maria C Vogel
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA.
| |
Collapse
|
15
|
Huo Y, Lu W, Tian Y, Hou Q, Man HY. Prkn knockout mice show autistic-like behaviors and aberrant synapse formation. iScience 2022; 25:104573. [PMID: 35789851 PMCID: PMC9249611 DOI: 10.1016/j.isci.2022.104573] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 02/26/2022] [Accepted: 06/07/2022] [Indexed: 11/20/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with high genetic heterogeneity, affecting one in 44 children in the United States. Recent genomic sequencing studies from autistic human individuals indicate that PARK2, a gene that has long been considered in the pathogenesis of Parkinson's disease, is involved in ASD. Here, we report that Prkn knockout (KO) mice demonstrate autistic-like behaviors including impaired social interaction, elevated repetitive behaviors, and deficits in communication. In addition, Prkn KO mice show reduced neuronal activity in the context of sociability in the prelimbic cortex. Cell morphological examination of layer 5 prelimbic cortical neurons shows a reduction in dendritic arborization and spine number. Furthermore, biochemistry and immunocytochemistry analyses reveal alterations in synapse density and the molecular composition of synapses. These findings indicate that Prkn is implicated in brain development and suggest the potential use of the Prkn KO mouse as a model for autism research.
Collapse
Affiliation(s)
- Yuda Huo
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Wen Lu
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Yuan Tian
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Qingming Hou
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Heng-Ye Man
- Department of Biology, Boston University, Boston, MA 02215, USA
- Department of Pharmacology & Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118, USA
- Center for Systems Neuroscience, Boston University, Boston, MA 02215, USA
| |
Collapse
|
16
|
Keeping Synapses in Shape: Degradation Pathways in the Healthy and Aging Brain. Neuronal Signal 2022; 6:NS20210063. [PMID: 35813265 PMCID: PMC9208270 DOI: 10.1042/ns20210063] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
Abstract
Synapses maintain their molecular composition, plasticity and function through the concerted action of protein synthesis and removal. The complex and polarized neuronal architecture poses specific challenges to the logistics of protein and organelle turnover since protein synthesis and degradation mainly happen in the cell soma. In addition, post-mitotic neurons accumulate damage over a lifetime, challenging neuronal degradative pathways and making them particularly susceptible to the effects of aging. This review will summarize the current knowledge on neuronal protein turnover mechanisms with a particular focus on the presynapse, including the proteasome, autophagy and the endolysosomal route and their roles in regulating presynaptic proteostasis and function. In addition, the author will discuss how physiological brain aging, which entails a progressive decline in cognitive functions, affects synapses and the degradative machinery.
Collapse
|
17
|
Griffey CJ, Yamamoto A. Macroautophagy in CNS health and disease. Nat Rev Neurosci 2022; 23:411-427. [PMID: 35505254 DOI: 10.1038/s41583-022-00588-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2022] [Indexed: 12/12/2022]
Abstract
Macroautophagy is an evolutionarily conserved process that delivers diverse cellular contents to lysosomes for degradation. As our understanding of this pathway grows, so does our appreciation for its importance in disorders of the CNS. Once implicated primarily in neurodegenerative events owing to acute injury and ageing, macroautophagy is now also linked to disorders of neurodevelopment, indicating that it is essential for both the formation and maintenance of a healthy CNS. In parallel to understanding the significance of macroautophagy across contexts, we have gained a greater mechanistic insight into its physiological regulation and the breadth of cargoes it can degrade. Macroautophagy is a broadly used homeostatic process, giving rise to questions surrounding how defects in this single pathway could cause diseases with distinct clinical and pathological signatures. To address this complexity, we herein review macroautophagy in the mammalian CNS by examining three key features of the process and its relationship to disease: how it functions at a basal level in the discrete cell types of the brain and spinal cord; which cargoes are being degraded in physiological and pathological settings; and how the different stages of the macroautophagy pathway intersect with diseases of neurodevelopment and adult-onset neurodegeneration.
Collapse
Affiliation(s)
- Christopher J Griffey
- Doctoral Program in Neurobiology and Behaviour, Medical Scientist Training Program, Columbia University, New York, NY, USA
| | - Ai Yamamoto
- Departments of Neurology, and Pathology and Cell Biology, Columbia University, New York, NY, USA.
| |
Collapse
|
18
|
Gundelfinger ED, Karpova A, Pielot R, Garner CC, Kreutz MR. Organization of Presynaptic Autophagy-Related Processes. Front Synaptic Neurosci 2022; 14:829354. [PMID: 35368245 PMCID: PMC8968026 DOI: 10.3389/fnsyn.2022.829354] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Brain synapses pose special challenges on the quality control of their protein machineries as they are far away from the neuronal soma, display a high potential for plastic adaptation and have a high energy demand to fulfill their physiological tasks. This applies in particular to the presynaptic part where neurotransmitter is released from synaptic vesicles, which in turn have to be recycled and refilled in a complex membrane trafficking cycle. Pathways to remove outdated and damaged proteins include the ubiquitin-proteasome system acting in the cytoplasm as well as membrane-associated endolysosomal and the autophagy systems. Here we focus on the latter systems and review what is known about the spatial organization of autophagy and endolysomal processes within the presynapse. We provide an inventory of which components of these degradative systems were found to be present in presynaptic boutons and where they might be anchored to the presynaptic apparatus. We identify three presynaptic structures reported to interact with known constituents of membrane-based protein-degradation pathways and therefore may serve as docking stations. These are (i) scaffolding proteins of the cytomatrix at the active zone, such as Bassoon or Clarinet, (ii) the endocytic machinery localized mainly at the peri-active zone, and (iii) synaptic vesicles. Finally, we sketch scenarios, how presynaptic autophagic cargos are tagged and recruited and which cellular mechanisms may govern membrane-associated protein turnover in the presynapse.
Collapse
Affiliation(s)
- Eckart D. Gundelfinger
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Institute of Pharmacology and Toxicology, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- *Correspondence: Eckart D. Gundelfinger,
| | - Anna Karpova
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Rainer Pielot
- Institute of Pharmacology and Toxicology, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Craig C. Garner
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
- Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Michael R. Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- Center for Molecular Neurobiology (ZMNH), University Hospital Hamburg-Eppendorf, Hamburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| |
Collapse
|
19
|
Goldsmith J, Ordureau A, Harper JW, Holzbaur ELF. Brain-derived autophagosome profiling reveals the engulfment of nucleoid-enriched mitochondrial fragments by basal autophagy in neurons. Neuron 2022; 110:967-976.e8. [PMID: 35051374 PMCID: PMC8930448 DOI: 10.1016/j.neuron.2021.12.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/18/2021] [Accepted: 12/16/2021] [Indexed: 12/20/2022]
Abstract
Neurons depend on autophagy to maintain cellular homeostasis, and defects in autophagy are pathological hallmarks of neurodegenerative disease. To probe the role of basal autophagy in the maintenance of neuronal health, we isolated autophagic vesicles from mouse brain tissue and used proteomics to identify the major cargos engulfed within autophagosomes, validating our findings in rodent primary and human iPSC-derived neurons. Mitochondrial proteins were identified as a major cargo in the absence of mitophagy adaptors such as OPTN. We found that nucleoid-associated proteins are enriched compared with other mitochondrial components. In the axon, autophagic engulfment of nucleoid-enriched mitochondrial fragments requires the mitochondrial fission machinery Drp1. We proposed that localized Drp1-dependent fission of nucleoid-enriched fragments in proximity to the sites of autophagosome biogenesis enhances their capture. The resulting efficient autophagic turnover of nucleoids may prevent accumulation of mitochondrial DNA in the neuron, thus mitigating activation of proinflammatory pathways that contribute to neurodegeneration.
Collapse
Affiliation(s)
- Juliet Goldsmith
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Alban Ordureau
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - J Wade Harper
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| |
Collapse
|
20
|
Grochowska KM, Andres‐Alonso M, Karpova A, Kreutz MR. The needs of a synapse—How local organelles serve synaptic proteostasis. EMBO J 2022; 41:e110057. [PMID: 35285533 PMCID: PMC8982616 DOI: 10.15252/embj.2021110057] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/24/2021] [Accepted: 02/10/2022] [Indexed: 12/12/2022] Open
Abstract
Synaptic function crucially relies on the constant supply and removal of neuronal membranes. The morphological complexity of neurons poses a significant challenge for neuronal protein transport since the machineries for protein synthesis and degradation are mainly localized in the cell soma. In response to this unique challenge, local micro‐secretory systems have evolved that are adapted to the requirements of neuronal membrane protein proteostasis. However, our knowledge of how neuronal proteins are synthesized, trafficked to membranes, and eventually replaced and degraded remains scarce. Here, we review recent insights into membrane trafficking at synaptic sites and into the contribution of local organelles and micro‐secretory pathways to synaptic function. We describe the role of endoplasmic reticulum specializations in neurons, Golgi‐related organelles, and protein complexes like retromer in the synthesis and trafficking of synaptic transmembrane proteins. We discuss the contribution of autophagy and of proteasome‐mediated and endo‐lysosomal degradation to presynaptic proteostasis and synaptic function, as well as nondegradative roles of autophagosomes and lysosomes in signaling and synapse remodeling. We conclude that the complexity of neuronal cyto‐architecture necessitates long‐distance protein transport that combines degradation with signaling functions.
Collapse
Affiliation(s)
- Katarzyna M Grochowska
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Maria Andres‐Alonso
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Anna Karpova
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
| | - Michael R Kreutz
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
| |
Collapse
|
21
|
Cai Q, Ganesan D. Regulation of neuronal autophagy and the implications in neurodegenerative diseases. Neurobiol Dis 2022; 162:105582. [PMID: 34890791 PMCID: PMC8764935 DOI: 10.1016/j.nbd.2021.105582] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/22/2021] [Accepted: 12/06/2021] [Indexed: 01/03/2023] Open
Abstract
Neurons are highly polarized and post-mitotic cells with the specific requirements of neurotransmission accompanied by high metabolic demands that create a unique challenge for the maintenance of cellular homeostasis. Thus, neurons rely heavily on autophagy that constitutes a key quality control system by which dysfunctional cytoplasmic components, protein aggregates, and damaged organelles are sequestered within autophagosomes and then delivered to the lysosome for degradation. While mature lysosomes are predominantly located in the soma of neurons, the robust, constitutive biogenesis of autophagosomes occurs in the synaptic terminal via a conserved pathway that is required to maintain synaptic integrity and function. Following formation, autophagosomes fuse with late endosomes and then are rapidly and efficiently transported by the microtubule-based cytoplasmic dynein motor along the axon toward the soma for lysosomal clearance. In this review, we highlight the recent knowledge of the roles of autophagy in neuronal health and disease. We summarize the available evidence about the normal functions of autophagy as a protective factor against neurodegeneration and discuss the mechanism underlying neuronal autophagy regulation. Finally, we describe how autophagy function is affected in major neurodegenerative diseases with a special focus on Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral Sclerosis.
Collapse
|
22
|
Ghelani T, Montenegro-Venegas C, Fejtova A, Dresbach T. Nanoscopical Analysis Reveals an Orderly Arrangement of the Presynaptic Scaffold Protein Bassoon at the Golgi-Apparatus. Front Mol Neurosci 2021; 14:744034. [PMID: 34867184 PMCID: PMC8632625 DOI: 10.3389/fnmol.2021.744034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/22/2021] [Indexed: 11/18/2022] Open
Abstract
Bassoon is a core scaffold protein of the presynaptic active zone. In brain synapses, the C-terminus of Bassoon is oriented toward the plasma membrane and its N-terminus is oriented toward synaptic vesicles. At the Golgi-apparatus, Bassoon is thought to assemble active zone precursor structures, but whether it is arranged in an orderly fashion is unknown. Understanding the topology of this large scaffold protein is important for models of active zone biogenesis. Using stimulated emission depletion nanoscopy in cultured hippocampal neurons, we found that an N-terminal intramolecular tag of recombinant Bassoon, but not C-terminal tag, colocalized with markers of the trans-Golgi network (TGN). The N-terminus of Bassoon was located between 48 and 69 nm away from TGN38, while its C-terminus was located between 100 and 115 nm away from TGN38. Sequences within the first 95 amino acids of Bassoon were required for this arrangement. Our results indicate that, at the Golgi-apparatus, Bassoon is oriented with its N-terminus toward and its C-terminus away from the trans Golgi network membrane. Moreover, they suggest that Bassoon is an extended molecule at the trans Golgi network with the distance between amino acids 97 and 3,938, estimated to be between 46 and 52 nm. Our data are consistent with a model, in which the N-terminus of Bassoon binds to the membranes of the trans-Golgi network, while the C-terminus associates with active zone components, thus reflecting the topographic arrangement characteristic of synapses also at the Golgi-apparatus.
Collapse
Affiliation(s)
- Tina Ghelani
- Institute of Anatomy and Embryology, University Medical Center Göttingen, Göttingen, Germany
| | - Carolina Montenegro-Venegas
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Institute for Pharmacology and Toxicology, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
| | - Anna Fejtova
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Department of Psychiatry and Psychotherapy, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.,RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Thomas Dresbach
- Institute of Anatomy and Embryology, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
23
|
Kallergi E, Nikoletopoulou V. Macroautophagy and normal aging of the nervous system: Lessons from animal models. Cell Stress 2021; 5:146-166. [PMID: 34708187 PMCID: PMC8490955 DOI: 10.15698/cst2021.10.257] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 01/18/2023] Open
Abstract
Aging represents a cumulative form of cellular stress, which is thought to challenge many aspects of proteostasis. The non-dividing, long-lived neurons are particularly vulnerable to stress, and, not surprisingly, even normal aging is highly associated with a decline in brain function in humans, as well as in other animals. Macroautophagy is a fundamental arm of the proteostasis network, safeguarding proper protein turnover during different cellular states and against diverse cellular stressors. An intricate interplay between macroautophagy and aging is beginning to unravel, with the emergence of new tools, including those for monitoring autophagy in cultured neurons and in the nervous system of different organisms in vivo. Here, we review recent findings on the impact of aging on neuronal integrity and on neuronal macroautophagy, as they emerge from studies in invertebrate and mammalian models.
Collapse
Affiliation(s)
- Emmanouela Kallergi
- University of Lausanne, Department of Fundamental Neurosciences, Lausanne, Switzerland
| | | |
Collapse
|
24
|
Annamneedi A, del Angel M, Gundelfinger ED, Stork O, Çalışkan G. The Presynaptic Scaffold Protein Bassoon in Forebrain Excitatory Neurons Mediates Hippocampal Circuit Maturation: Potential Involvement of TrkB Signalling. Int J Mol Sci 2021; 22:ijms22157944. [PMID: 34360710 PMCID: PMC8347324 DOI: 10.3390/ijms22157944] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/30/2022] Open
Abstract
A presynaptic active zone organizer protein Bassoon orchestrates numerous important functions at the presynaptic active zone. We previously showed that the absence of Bassoon exclusively in forebrain glutamatergic presynapses (BsnEmx1cKO) in mice leads to developmental disturbances in dentate gyrus (DG) affecting synaptic excitability, morphology, neurogenesis and related behaviour during adulthood. Here, we demonstrate that hyperexcitability of the medial perforant path-to-DG (MPP-DG) pathway in BsnEmx1cKO mice emerges during adolescence and is sustained during adulthood. We further provide evidence for a potential involvement of tropomyosin-related kinase B (TrkB), the high-affinity receptor for brain-derived neurotrophic factor (BDNF), mediated signalling. We detect elevated TrkB protein levels in the dorsal DG of adult mice (~3–5 months-old) but not in adolescent (~4–5 weeks-old) mice. Electrophysiological analysis reveals increased field-excitatory-postsynaptic-potentials (fEPSPs) in the DG of the adult, but not in adolescent BsnEmx1cKO mice. In line with an increased TrkB expression during adulthood in BsnEmx1cKO, blockade of TrkB normalizes the increased synaptic excitability in the DG during adulthood, while no such effect was observed in adolescence. Accordingly, neurogenesis, which has previously been found to be increased in adult BsnEmx1cKO mice, was unaffected at adolescent age. Our results suggest that Bassoon plays a crucial role in the TrkB-dependent postnatal maturation of the hippocampus.
Collapse
Affiliation(s)
- Anil Annamneedi
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
- Leibniz Institute for Neurobiology (LIN), RG Neuroplasticity, 39118 Magdeburg, Germany
- Correspondence: (A.A.); (G.Ç.)
| | - Miguel del Angel
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
| | - Eckart D. Gundelfinger
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
- Leibniz Institute for Neurobiology (LIN), RG Neuroplasticity, 39118 Magdeburg, Germany
- Institute of Pharmacology & Toxicology, Medical Faculty, Otto-von-Guericke University, 39120 Magdeburg, Germany
| | - Oliver Stork
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
| | - Gürsel Çalışkan
- Institute of Biology, Otto-Von-Guericke University, 39120 Magdeburg, Germany; (M.d.A.); (O.S.)
- Center for Behavioral Brain Sciences (CBBS), 39120 Magdeburg, Germany;
- Correspondence: (A.A.); (G.Ç.)
| |
Collapse
|
25
|
Historical perspective and progress on protein ubiquitination at glutamatergic synapses. Neuropharmacology 2021; 196:108690. [PMID: 34197891 DOI: 10.1016/j.neuropharm.2021.108690] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/07/2021] [Accepted: 06/22/2021] [Indexed: 12/23/2022]
Abstract
Transcription-translation coupling leads to the production of proteins that are key for controlling essential neuronal processes that include neuronal development and changes in synaptic strength. Although these events have been a prevailing theme in neuroscience, the regulation of proteins via posttranslational signaling pathways are equally relevant for these neuronal processes. Ubiquitin is one type of posttranslational modification that covalently attaches to its targets/substrates. Ubiquitination of proteins play a key role in multiple signaling pathways, the predominant being removal of its substrates by a large molecular machine called the proteasome. Here, I review 40 years of progress on ubiquitination in the nervous system at glutamatergic synapses focusing on axon pathfinding, synapse formation, presynaptic release, dendritic spine formation, and regulation of postsynaptic glutamate receptors. Finally, I elucidate emerging themes in ubiquitin biology that may challenge our current understanding of ubiquitin signaling in the nervous system.
Collapse
|
26
|
Grosso Jasutkar H, Yamamoto A. Do Changes in Synaptic Autophagy Underlie the Cognitive Impairments in Huntington's Disease? J Huntingtons Dis 2021; 10:227-238. [PMID: 33780373 PMCID: PMC8293641 DOI: 10.3233/jhd-200466] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although Huntington's disease (HD) is classically considered from the perspective of the motor syndrome, the cognitive changes in HD are prominent and often an early manifestation of disease. As such, investigating the underlying pathophysiology of cognitive changes may give insight into important and early neurodegenerative events. In this review, we first discuss evidence from both HD patients and animal models that cognitive changes correlate with early pathological changes at the synapse, an observation that is similarly made in other neurodegenerative conditions that primarily affect cognition. We then describe how autophagy plays a critical role supporting synaptic maintenance in the healthy brain, and how autophagy dysfunction in HD may thereby lead to impaired synaptic maintenance and thus early manifestations of disease.
Collapse
Affiliation(s)
| | - Ai Yamamoto
- Department of Neurology, Columbia University, New York, NY, USA.,Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| |
Collapse
|
27
|
Crawley O, Grill B. Autophagy in axonal and presynaptic development. Curr Opin Neurobiol 2021; 69:139-148. [PMID: 33940492 DOI: 10.1016/j.conb.2021.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/17/2021] [Accepted: 03/21/2021] [Indexed: 10/21/2022]
Abstract
The study of autophagy in the nervous system has predominantly centered on degeneration. Evidence is now cementing crucial roles for autophagy in neuronal development and growth, especially in axonal and presynaptic compartments. A picture is emerging that autophagy typically promotes the growth of axons and reduces presynaptic stability. Nonetheless, these are not rigid principles, and it remains unclear why autophagy does not always display these relationships during axonal and presynaptic development. Recent progress has identified mechanisms underlying spatiotemporal control of autophagy in neurons and begun to unravel how autophagy is integrated with other cellular processes, such as proteasomal degradation and axon guidance. Ultimately, understanding how autophagy is regulated and its role in the developing nervous system is key to comprehending how the nervous system assembles its stereotyped yet plastic configuration. It is also likely to inform how we think about neurodevelopmental disorders and neurodegenerative diseases.
Collapse
Affiliation(s)
- Oliver Crawley
- Unidad de Neurobiología Celular y de Sistemas, Instituto de Neurociencias (CSIC-UMH), San Juan de Alicante, 03550, Spain.
| | - Brock Grill
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, 98199, USA; Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA; Department of Pharmacology, University of Washington School of Medicine, Seattle, WA, USA.
| |
Collapse
|
28
|
Valencia M, Kim SR, Jang Y, Lee SH. Neuronal Autophagy: Characteristic Features and Roles in Neuronal Pathophysiology. Biomol Ther (Seoul) 2021; 29:605-614. [PMID: 33875624 PMCID: PMC8551733 DOI: 10.4062/biomolther.2021.012] [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: 01/14/2021] [Revised: 03/02/2021] [Accepted: 03/23/2021] [Indexed: 11/12/2022] Open
Abstract
Autophagy is an important degradative pathway that eliminates misfolded proteins and damaged organelles from cells. Autophagy is crucial for neuronal homeostasis and function. A lack of or deficiency in autophagy leads to the accumulation of protein aggregates, which are associated with several neurodegenerative diseases. Compared with non-neuronal cells, neurons exhibit rapid autophagic flux because damaged organelles or protein aggregates cannot be diluted in post-mitotic cells; because of this, these cells exhibit characteristic features of autophagy, such as compartment-specific autophagy, which depends on polarized structures and rapid autophagy flux. In addition, neurons exhibit compartment-specific autophagy, which depends on polarized structures. Neuronal autophagy may have additional physiological roles other than amino acid recycling. In this review, we focus on the characteristics and regulatory factors of neuronal autophagy. We also describe intracellular selective autophagy in neurons and its association with neurodegenerative diseases.
Collapse
Affiliation(s)
- McNeil Valencia
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Sung Rae Kim
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Yeseul Jang
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Sung Hoon Lee
- College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| |
Collapse
|
29
|
Soykan T, Haucke V, Kuijpers M. Mechanism of synaptic protein turnover and its regulation by neuronal activity. Curr Opin Neurobiol 2021; 69:76-83. [PMID: 33744822 DOI: 10.1016/j.conb.2021.02.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/11/2021] [Accepted: 02/12/2021] [Indexed: 12/23/2022]
Abstract
Neurons are long-lived cells with a complex architecture, in which synapses may be located far away from the cell body and are subject to plastic changes, thereby posing special challenges to the systems that maintain and dynamically regulate the synaptic proteome. These mechanisms include neuronal autophagy and the endolysosome pathway, as well as the ubiquitin/proteasome system, which cooperate in the constitutive and regulated turnover of presynaptic and postsynaptic proteins. Here, we summarize the pathways involved in synaptic protein degradation and the mechanisms underlying their regulation, for example, by neuronal activity, with an emphasis on the presynaptic compartment and outline perspectives for future research. Keywords: Synapse, Synaptic vesicle, Autophagy, Endolysosome, Proteasome, Protein turnover, Protein degradation, Endosome, Lysosome.
Collapse
Affiliation(s)
- Tolga Soykan
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Volker Haucke
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Straße 10, 13125 Berlin, Germany; Freie Universität Berlin, Faculty of Biology, Chemistry, Pharmacy, 14195, Berlin, Germany.
| | - Marijn Kuijpers
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Straße 10, 13125 Berlin, Germany.
| |
Collapse
|
30
|
Andres-Alonso M, Kreutz MR, Karpova A. Autophagy and the endolysosomal system in presynaptic function. Cell Mol Life Sci 2020; 78:2621-2639. [PMID: 33340068 PMCID: PMC8004491 DOI: 10.1007/s00018-020-03722-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 11/17/2020] [Accepted: 11/24/2020] [Indexed: 12/11/2022]
Abstract
The complex morphology of neurons, the specific requirements of synaptic neurotransmission and the accompanying metabolic demands create a unique challenge for proteostasis. The main machineries for neuronal protein synthesis and degradation are localized in the soma, while synaptic junctions are found at vast distances from the cell body. Sophisticated mechanisms must, therefore, ensure efficient delivery of newly synthesized proteins and removal of faulty proteins. These requirements are exacerbated at presynaptic sites, where the demands for protein turnover are especially high due to synaptic vesicle release and recycling that induces protein damage in an intricate molecular machinery, and where replacement of material is hampered by the extreme length of the axon. In this review, we will discuss the contribution of the two major pathways in place, autophagy and the endolysosomal system, to presynaptic protein turnover and presynaptic function. Although clearly different in their biogenesis, both pathways are characterized by cargo collection and transport into distinct membrane-bound organelles that eventually fuse with lysosomes for cargo degradation. We summarize the available evidence with regard to their degradative function, their regulation by presynaptic machinery and the cargo for each pathway. Finally, we will discuss the interplay of both pathways in neurons and very recent findings that suggest non-canonical functions of degradative organelles in synaptic signalling and plasticity.
Collapse
Affiliation(s)
- Maria Andres-Alonso
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany
- Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany
| | - Michael R Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany.
- Leibniz Group 'Dendritic Organelles and Synaptic Function', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251, Hamburg, Germany.
- Center for Behavioral Brain Sciences, Otto Von Guericke University, Magdeburg, Germany.
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.
| | - Anna Karpova
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, 39118, Magdeburg, Germany.
- Center for Behavioral Brain Sciences, Otto Von Guericke University, Magdeburg, Germany.
| |
Collapse
|
31
|
Tsang AH, Nuzzaci D, Darwish T, Samudrala H, Blouet C. Nutrient sensing in the nucleus of the solitary tract mediates non-aversive suppression of feeding via inhibition of AgRP neurons. Mol Metab 2020; 42:101070. [PMID: 32898712 PMCID: PMC7549147 DOI: 10.1016/j.molmet.2020.101070] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/26/2020] [Accepted: 09/02/2020] [Indexed: 01/03/2023] Open
Abstract
The nucleus of the solitary tract (NTS) is emerging as a major site of action for the appetite-suppressive effects of leading pharmacotherapies currently investigated to treat obesity. However, our understanding of how NTS neurons regulate appetite remains incomplete. OBJECTIVES In this study, we used NTS nutrient sensing as an entry point to characterize stimulus-defined neuronal ensembles engaged by the NTS to produce physiological satiety. METHODS We combined histological analysis, neuroanatomical assessment using inducible viral tracing tools, and functional tests to characterize hindbrain-forebrain circuits engaged by NTS leucine sensing to suppress hunger. RESULTS We found that NTS detection of leucine engages NTS prolactin-releasing peptide (PrRP) neurons to inhibit AgRP neurons via a population of leptin receptor-expressing neurons in the dorsomedial hypothalamus. This circuit is necessary for the anorectic response to NTS leucine, the appetite-suppressive effect of high-protein diets, and the long-term control of energy balance. CONCLUSIONS These results extend the integrative capability of AgRP neurons to include brainstem nutrient sensing inputs.
Collapse
Affiliation(s)
- Anthony H Tsang
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Danae Nuzzaci
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Tamana Darwish
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Havish Samudrala
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK
| | - Clémence Blouet
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 0QQ, UK.
| |
Collapse
|
32
|
Overhoff M, De Bruyckere E, Kononenko NL. Mechanisms of neuronal survival safeguarded by endocytosis and autophagy. J Neurochem 2020; 157:263-296. [PMID: 32964462 DOI: 10.1111/jnc.15194] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/21/2020] [Accepted: 09/08/2020] [Indexed: 12/11/2022]
Abstract
Multiple aspects of neuronal physiology crucially depend on two cellular pathways, autophagy and endocytosis. During endocytosis, extracellular components either unbound or recognized by membrane-localized receptors (termed "cargo") become internalized into plasma membrane-derived vesicles. These can serve to either recycle the material back to the plasma membrane or send it for degradation to lysosomes. Autophagy also uses lysosomes as a terminal degradation point, although instead of degrading the plasma membrane-derived cargo, autophagy eliminates detrimental cytosolic material and intracellular organelles, which are transported to lysosomes by means of double-membrane vesicles, referred to as autophagosomes. Neurons, like all non-neuronal cells, capitalize on autophagy and endocytosis to communicate with the environment and maintain protein and organelle homeostasis. Additionally, the highly polarized, post-mitotic nature of neurons made them adopt these two pathways for cell-specific functions. These include the maintenance of the synaptic vesicle pool in the pre-synaptic terminal and the long-distance transport of signaling molecules. Originally discovered independently from each other, it is now clear that autophagy and endocytosis are closely interconnected and share several common participating molecules. Considering the crucial role of autophagy and endocytosis in cell type-specific functions in neurons, it is not surprising that defects in both pathways have been linked to the pathology of numerous neurodegenerative diseases. In this review, we highlight the recent knowledge of the role of endocytosis and autophagy in neurons with a special focus on synaptic physiology and discuss how impairments in genes coding for autophagy and endocytosis proteins can cause neurodegeneration.
Collapse
Affiliation(s)
- Melina Overhoff
- CECAD Cluster of Excellence, Institute for Genetics, University of Cologne, Cologne, Germany
| | - Elodie De Bruyckere
- CECAD Cluster of Excellence, Institute for Genetics, University of Cologne, Cologne, Germany
| | - Natalia L Kononenko
- CECAD Cluster of Excellence, Institute for Genetics, University of Cologne, Cologne, Germany
| |
Collapse
|
33
|
Montenegro-Venegas C, Annamneedi A, Hoffmann-Conaway S, Gundelfinger ED, Garner CC. BSN (bassoon) and PRKN/parkin in concert control presynaptic vesicle autophagy. Autophagy 2020; 16:1732-1733. [PMID: 32718208 DOI: 10.1080/15548627.2020.1801259] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Maintaining the integrity and function of the presynaptic neurotransmitter release apparatus is a demanding process for a post-mitotic neuron; the mechanisms behind it are still unclear. BSN (bassoon), an active zone scaffolding protein, has been implicated in the control of presynaptic macroautophagy/autophagy, a process we recently showed depends on poly-ubiquitination of synaptic proteins. Moreover, loss of BSN was found to lead to smaller synaptic vesicle (SV) pools and younger pools of the SV protein SV2. Of note, the E3 ligase PRKN/parkin appears to be involved in BSN deficiency-related changes in autophagy levels, as shRNA-mediated knockdown of PRKN counteracts BSN-deficiency and rescues decreased SV protein levels as well as impaired SV recycling in primary cultured neurons. These data imply that BSN and PRKN act in concert to control presynaptic autophagy and maintain presynaptic proteostasis and SV turnover at the physiologically required levels.
Collapse
Affiliation(s)
- Carolina Montenegro-Venegas
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology , Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS) , Magdeburg, Germany.,Institute for Pharmacology and Toxicology, Medical Faculty, Otto Von Guericke University , Magdeburg, Germany
| | - Anil Annamneedi
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology , Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS) , Magdeburg, Germany.,Institute of Biology, Otto Von Guericke University , Magdeburg, Germany
| | | | - Eckart D Gundelfinger
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology , Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS) , Magdeburg, Germany.,Molecular Neurobiology, Medical Faculty, Otto Von Guericke University , Magdeburg, Germany
| | - Craig C Garner
- German Center for Neurodegenerative Diseases (DZNE) , Berlin, Germany.,Charité - Universitätsmedizin Berlin, Institute of Neurobiology , Berlin, Germany.,NeuroCure Cluster of Excellence, Charité - Universitätsmedizin Berlin , Berlin, Germany
| |
Collapse
|
34
|
Montenegro-Venegas C, Fienko S, Anni D, Pina-Fernández E, Frischknecht R, Fejtova A. Bassoon inhibits proteasome activity via interaction with PSMB4. Cell Mol Life Sci 2020; 78:1545-1563. [PMID: 32651614 PMCID: PMC7904567 DOI: 10.1007/s00018-020-03590-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 06/19/2020] [Accepted: 07/01/2020] [Indexed: 01/06/2023]
Abstract
Abstract Proteasomes are protein complexes that mediate controlled degradation of damaged or unneeded cellular proteins. In neurons, proteasome regulates synaptic function and its dysfunction has been linked to neurodegeneration and neuronal cell death. However, endogenous mechanisms controlling proteasomal activity are insufficiently understood. Here, we describe a novel interaction between presynaptic scaffolding protein bassoon and PSMB4, a β subunit of the 20S core proteasome. Expression of bassoon fragments that interact with PSMB4 in cell lines or in primary neurons attenuates all endopeptidase activities of cellular proteasome and induces accumulation of several classes of ubiquitinated and non-ubiquitinated substrates of the proteasome. Importantly, these effects are distinct from the previously reported impact of bassoon on ubiquitination and autophagy and might rely on a steric interference with the assembly of the 20S proteasome core. In line with a negative regulatory role of bassoon on endogenous proteasome we found increased proteasomal activity in the synaptic fractions prepared from brains of bassoon knock-out mice. Finally, increased activity of proteasome and lower expression levels of synaptic substrates of proteasome could be largely normalized upon expression of PSMB4-interacting fragments of bassoon in neurons derived from bassoon deficient mice. Collectively, we propose that bassoon interacts directly with proteasome to control its activity at presynapse and thereby it contributes to a compartment-specific regulation of neuronal protein homeostasis. These findings provide a mechanistic explanation for the recently described link of bassoon to human diseases associated with pathological protein aggregation. Graphic Abstract Presynaptic cytomatrix protein bassoon (Bsn) interacts with PSMB4, the β7 subunit of 20S core proteasome, via three independent interaction interfaces. Bsn inhibits proteasomal proteolytic activity and degradation of different classes of proteasomal substrates presumably due to steric interference with the assembly of 20S core of proteasome. Upon Bsn deletion in neurons, presynaptic substrates of the proteasome are depleted, which can be reversed upon expression of PSMB4-interacting interfaces of Bsn. Taken together, bsn controls the degree of proteasome degradation within the presynaptic compartment and thus, contributes to the regulation of synaptic proteome![]() Electronic supplementary material The online version of this article (10.1007/s00018-020-03590-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Carolina Montenegro-Venegas
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Institute for Pharmacology and Toxicology, Otto-von-Guericke University and Center for Behavior Brain Sciences (CBBS), Magdeburg, Germany
| | - Sandra Fienko
- Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Huntington's Disease Centre, Department of Neurodegenerative Disease, UK Dementia Research Institute at UCL, Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Daniela Anni
- Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Eneko Pina-Fernández
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Renato Frischknecht
- Department of Biology, Animal Physiology, Friedrich-Alexander University of Erlangen- Nürnberg, Erlangen, Germany
| | - Anna Fejtova
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.
- Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany.
| |
Collapse
|