1
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Jin Y, Zhao L, Zhang Y, Chen T, Shi H, Sun H, Ding S, Chen S, Cao H, Zhang G, Li Q, Gao J, Xiao M, Sheng C. BIN1 deficiency enhances ULK3-dependent autophagic flux and reduces dendritic size in mouse hippocampal neurons. Autophagy 2024:1-20. [PMID: 39171951 DOI: 10.1080/15548627.2024.2393932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/09/2024] [Accepted: 08/14/2024] [Indexed: 08/23/2024] Open
Abstract
Genome-wide association studies identified variants around the BIN1 (bridging integrator 1) gene locus as prominent risk factors for late-onset Alzheimer disease. In the present study, we decreased the expression of BIN1 in mouse hippocampal neurons to investigate its neuronal function. Bin1 knockdown via RNAi reduced the dendritic arbor size in primary cultured hippocampal neurons as well as in mature Cornu Ammonis 1 excitatory neurons. The AAV-mediated Bin1 RNAi knockdown also generated a significant regional volume loss around the injection sites at the organ level, as revealed by 7-Tesla structural magnetic resonance imaging, and an impaired spatial reference memory performance in the Barnes maze test. Unexpectedly, Bin1 knockdown led to concurrent activation of both macroautophagy/autophagy and MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1). Autophagy inhibition with the lysosome inhibitor chloroquine effectively mitigated the Bin1 knockdown-induced dendritic regression. The subsequent molecular studydemonstrated that increased expression of ULK3 (unc-51 like kinase 3), which is MTOR-insensitive, supported autophagosome formation in BIN1 deficiency. Reducing ULK3 activity with SU6668, a receptor tyrosine kinase inhibitor, or decreasing neuronal ULK3 expression through AAV-mediated RNAi, significantly attenuated Bin1 knockdown-induced hippocampal volume loss and spatial memory decline. In Alzheimer disease patients, the major neuronal isoform of BIN1 is specifically reduced. Our work suggests this reduction is probably an important molecular event that increases the autophagy level, which might subsequently promote brain atrophy and cognitive impairment through reducing dendritic structures, and ULK3 is a potential interventional target for relieving these detrimental effects.Abbreviations: AV: adeno-associated virus; Aβ: amyloid-β; ACTB: actin, beta; AD: Alzheimer disease; Aduk: Another Drosophila Unc-51-like kinase; AKT1: thymoma viral proto-oncogene 1; AMPK: AMP-activated protein kinase; AP: autophagosome; BafA1: bafilomycin A1; BDNF: brain derived neurotrophic factor; BIN1: bridging integrator 1; BIN1-iso1: BIN1, isoform 1; CA1: cornu Ammonis 1; CA3: cornu Ammonis 3; CLAP: clathrin and adapter binding; CQ: chloroquine; DMEM: Dulbecco's modified Eagle medium; EGFP: enhanced green fluorescent protein; GWAS: genome-wide association study; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MRI: magnetic resonance imaging; MTOR; mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; PET: positron emission tomography; qRT-PCR: real-time quantitative reverse transcription PCR; ROS: reactive oxygen species; RPS6KB1: ribosomal protein S6 kinase B1; TFEB: transcription factor EB; ULK1: unc-51 like kinase 1; ULK3: unc-51 like kinase 3.
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Affiliation(s)
- Yuxi Jin
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Lin Zhao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Yanli Zhang
- Department of Psychiatry, The Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou, China
- Changzhou Medical Center, Nanjing Medical University, Changzhou, China
| | - Tingzhen Chen
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- Department of Critical Care Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Huili Shi
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Huaiqing Sun
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Shixin Ding
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Sijia Chen
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Haifeng Cao
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Guannan Zhang
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Qian Li
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Junying Gao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Ming Xiao
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- Brain Institute, Nanjing Brain Hospital, Nanjing Medical University, Nanjing, China
| | - Chengyu Sheng
- Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
- School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
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2
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Courson JA, Rumbaut RE, Burns AR. Impact of Obesity and Age on Mouse Corneal Innervation at the Epithelial-Stromal Interface. Invest Ophthalmol Vis Sci 2024; 65:11. [PMID: 38709524 PMCID: PMC11078165 DOI: 10.1167/iovs.65.5.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 04/23/2024] [Indexed: 05/07/2024] Open
Abstract
Purpose The corneal epithelium is the most highly innervated structure in the body. Previously, we reported a novel event whereby stromal axons fuse with basal epithelial cells, limiting nerve penetration into the epithelium. Although corneal-epithelial nerves undergo changes in sensitivity and distribution throughout life and in response to an obesogenic diet, it is unknown if neuronal-epithelial cell fusion is altered. Here, we sought to determine if neuronal-epithelial cell fusion frequency correlates with obesogenic diet consumption and age. Methods Corneas were collected from C57BL/6 mice and evaluated for neuronal-epithelial cell fusion frequency using serial block-face scanning electron microscopy. To assess the correlation between diet-induced obesity and fusion frequency, 6-week-old mice were fed either a normal diet or an obesogenic diet for 10 weeks. To assess changes in fusion frequency between young and adult mice under normal dietary conditions, 9- and 24-week-old mice were used. Results Mice fed a 10-week obesogenic diet showed 87% of central-cornea stromal nerves engaged in fusion compared with only 54% in age-matched controls (16 weeks old). In 9-week-old normal-diet animals, 48% of central-cornea stromal nerves contained fusing axons and increased to 81% at 24 weeks of age. Corneal sensitivity loss correlated with increased body weight and adiposity regardless of age and diet. Conclusions Neuronal-epithelial cell fusion positively correlates with age and obesogenic diet consumption, and corneal nerve sensitivity loss correlates with increased body weight and adiposity, regardless of age and diet. As such, neuronal-epithelial cell fusion may play a role in corneal nerve density and sensitivity regulation.
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Affiliation(s)
- Justin A. Courson
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States
- Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States
| | - Rolando E. Rumbaut
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States
- Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States
| | - Alan R. Burns
- College of Optometry, University of Houston, Houston, Texas, United States
- Children's Nutrition Center, Baylor College of Medicine, Houston, Texas, United States
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3
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Szypulski K, Tyszka A, Pyza E, Damulewicz M. Autophagy as a new player in the regulation of clock neurons physiology of Drosophila melanogaster. Sci Rep 2024; 14:6085. [PMID: 38480808 PMCID: PMC10937918 DOI: 10.1038/s41598-024-56649-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 03/08/2024] [Indexed: 03/17/2024] Open
Abstract
Axonal terminals of the small ventral lateral neurons (sLNvs), the circadian clock neurons of Drosophila, show daily changes in their arborization complexity, with many branches in the morning and their shrinkage during the night. This complex phenomenon is precisely regulated by several mechanisms. In the present study we describe that one of them is autophagy, a self-degradative process, also involved in changes of cell membrane size and shape. Our results showed that autophagosome formation and processing in PDF-expressing neurons (both sLNv and lLNv) are rhythmic and they have different patterns in the cell bodies and terminals. These rhythmic changes in the autophagy activity seem to be important for neuronal plasticity. We found that autophagosome cargos are different during the day and night, and more proteins involved in membrane remodeling are present in autophagosomes in the morning. In addition, we described for the first time that Atg8-positive vesicles are also present outside the sLNv terminals, which suggests that secretory autophagy might be involved in regulating the clock signaling network. Our data indicate that rhythmic autophagy in clock neurons affect the pacemaker function, through remodeling of terminal membrane and secretion of specific proteins from sLNvs.
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Affiliation(s)
- Kornel Szypulski
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Aleksandra Tyszka
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Elzbieta Pyza
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, Poland
| | - Milena Damulewicz
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, Krakow, Poland.
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4
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Liénard C, Pintart A, Bomont P. Neuronal Autophagy: Regulations and Implications in Health and Disease. Cells 2024; 13:103. [PMID: 38201307 PMCID: PMC10778363 DOI: 10.3390/cells13010103] [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: 10/26/2023] [Revised: 12/02/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
Autophagy is a major degradative pathway that plays a key role in sustaining cell homeostasis, integrity, and physiological functions. Macroautophagy, which ensures the clearance of cytoplasmic components engulfed in a double-membrane autophagosome that fuses with lysosomes, is orchestrated by a complex cascade of events. Autophagy has a particularly strong impact on the nervous system, and mutations in core components cause numerous neurological diseases. We first review the regulation of autophagy, from autophagosome biogenesis to lysosomal degradation and associated neurodevelopmental/neurodegenerative disorders. We then describe how this process is specifically regulated in the axon and in the somatodendritic compartment and how it is altered in diseases. In particular, we present the neuronal specificities of autophagy, with the spatial control of autophagosome biogenesis, the close relationship of maturation with axonal transport, and the regulation by synaptic activity. Finally, we discuss the physiological functions of autophagy in the nervous system, during development and in adulthood.
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Affiliation(s)
- Caroline Liénard
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
- CHU Montpellier, University of Montpellier, 34295 Montpellier, France
| | - Alexandre Pintart
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
| | - Pascale Bomont
- NeuroMyoGene Institute—PGNM, CNRS UMR 5261—INSERM U1315, University of Claude Bernard Lyon 1, 69008 Lyon, France; (C.L.); (A.P.)
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5
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Lewerissa EI, Nadif Kasri N, Linda K. Epigenetic regulation of autophagy-related genes: Implications for neurodevelopmental disorders. Autophagy 2024; 20:15-28. [PMID: 37674294 PMCID: PMC10761153 DOI: 10.1080/15548627.2023.2250217] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/11/2023] [Indexed: 09/08/2023] Open
Abstract
Macroautophagy/autophagy is an evolutionarily highly conserved catabolic process that is important for the clearance of cytosolic contents to maintain cellular homeostasis and survival. Recent findings point toward a critical role for autophagy in brain function, not only by preserving neuronal health, but especially by controlling different aspects of neuronal development and functioning. In line with this, mutations in autophagy-related genes are linked to various key characteristics and symptoms of neurodevelopmental disorders (NDDs), including autism, micro-/macrocephaly, and epilepsy. However, the group of NDDs caused by mutations in autophagy-related genes is relatively small. A significant proportion of NDDs are associated with mutations in genes encoding epigenetic regulatory proteins that modulate gene expression, so-called chromatinopathies. Intriguingly, several of the NDD-linked chromatinopathy genes have been shown to regulate autophagy-related genes, albeit in non-neuronal contexts. From these studies it becomes evident that tight transcriptional regulation of autophagy-related genes is crucial to control autophagic activity. This opens the exciting possibility that aberrant autophagic regulation might underly nervous system impairments in NDDs with disturbed epigenetic regulation. We here summarize NDD-related chromatinopathy genes that are known to regulate transcriptional regulation of autophagy-related genes. Thereby, we want to highlight autophagy as a candidate key hub mechanism in NDD-related chromatinopathies.Abbreviations: ADNP: activity dependent neuroprotector homeobox; ASD: autism spectrum disorder; ATG: AutTophaGy related; CpG: cytosine-guanine dinucleotide; DNMT: DNA methyltransferase; EHMT: euchromatic histone lysine methyltransferase; EP300: E1A binding protein p300; EZH2: enhancer of zeste 2 polycomb repressive complex 2 subunit; H3K4me3: histone 3 lysine 4 trimethylation; H3K9me1/2/3: histone 3 lysine 9 mono-, di-, or trimethylation; H3K27me2/3: histone 3 lysine 27 di-, or trimethylation; hiPSCs: human induced pluripotent stem cells; HSP: hereditary spastic paraplegia; ID: intellectual disability; KANSL1: KAT8 regulatory NSL complex subunit 1; KAT8: lysine acetyltransferase 8; KDM1A/LSD1: lysine demethylase 1A; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin complex 1; NDD: neurodevelopmental disorder; PHF8: PHD finger protein 8; PHF8-XLID: PHF8-X linked intellectual disability syndrome; PTM: post-translational modification; SESN2: sestrin 2; YY1: YY1 transcription factor; YY1AP1: YY1 associated protein 1.
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Affiliation(s)
- Elly I. Lewerissa
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, Gelderland, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, Gelderland, The Netherlands
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behavior, Nijmegen, Gelderland, The Netherlands
| | - Katrin Linda
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, Gelderland, The Netherlands
- VIB-KU Leuven Center for Brain & Disease Research, Leuven, Flemish Brabant, Belgium
- Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Flemish Brabant, Belgium
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6
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Ghate PS, Vacharasin JM, Ward JA, Nowling D, Kay V, Cowen MH, Lawlor MK, McCord M, Xu H, Carmona E, Cheon SH, Chukwurah E, Walla M, Lizarraga SB. The Warburg micro syndrome protein RAB3GAP1 modulates neuronal morphogenesis and interacts with axon elongation end ER-Golgi trafficking factors. Neurobiol Dis 2023; 184:106215. [PMID: 37385458 DOI: 10.1016/j.nbd.2023.106215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 05/26/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023] Open
Abstract
RAB3GAP1 is GTPase activating protein localized to the ER and Golgi compartments. In humans, mutations in RAB3GAP1 are the most common cause of Warburg Micro syndrome, a neurodevelopmental disorder associated with intellectual disability, microcephaly, and agenesis of the corpus callosum. We found that downregulation of RAB3GAP1 leads to a reduction in neurite outgrowth and complexity in human stem cell derived neurons. To further define the cellular function of RAB3GAP1, we sought to identify novel interacting proteins. We used a combination of mass spectrometry, co-immunoprecipitation and colocalization analysis and identified two novel interactors of RAB3GAP1: the axon elongation factor Dedicator of cytokinesis 7 (DOCK7) and the TATA modulatory factor 1 (TMF1) a modulator of Endoplasmic Reticulum (ER) to Golgi trafficking. To define the relationship between RAB3GAP1 and its two novel interactors, we analyzed their localization to different subcellular compartments in neuronal and non-neuronal cells with loss of RAB3GAP1. We find that RAB3GAP1 is important for the sub-cellular localization of TMF1 and DOCK7 across different compartments of the Golgi and endoplasmic reticulum. In addition, we find that loss of function mutations in RAB3GAP1 lead to dysregulation of pathways that are activated in response to the cellular stress like ATF6, MAPK, and PI3-AKT signaling. In summary, our findings suggest a novel role for RAB3GAP1 in neurite outgrowth that could encompass the regulation of proteins that control axon elongation, ER-Golgi trafficking, as well as pathways implicated in response to cellular stress.
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Affiliation(s)
- Pankaj S Ghate
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Janay M Vacharasin
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Joseph A Ward
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States of America; Center for Translational Neuroscience, Brown University, Providence, RI, United states of America
| | - Duncan Nowling
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Valerie Kay
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mara H Cowen
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mary-Kate Lawlor
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mikayla McCord
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Hailey Xu
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Esteban Carmona
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Seon-Hye Cheon
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Evelyn Chukwurah
- Department of Biology and Center for Childhood Neurotherapeutics, University of South Carolina, Columbia, SC, United States of America
| | - Mike Walla
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, United States of America
| | - Sofia B Lizarraga
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States of America; Center for Translational Neuroscience, Brown University, Providence, RI, United states of America.
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7
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Song JM, Kang M, Lee S, Kim J, Park S, Park DH, Lee S, Suh YH. Deneddylating enzyme SENP8 regulates neuronal development. J Neurochem 2023; 165:348-361. [PMID: 36847487 DOI: 10.1111/jnc.15797] [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: 10/15/2022] [Revised: 01/16/2023] [Accepted: 02/13/2023] [Indexed: 03/01/2023]
Abstract
Neddylation is a cellular process in which the neural precursor cell expressed, developmentally down-regulated 8 (NEDD8) is conjugated to the lysine residue of target proteins via serial enzymatic cascades. Recently, it has been demonstrated that neddylation is required for synaptic clustering of metabotropic glutamate receptor 7 (mGlu7) and postsynaptic density protein 95 (PSD-95), and the inhibition of neddylation impairs neurite outgrowth and excitatory synaptic maturation. Similar to the balanced role of deubiquitylating enzymes (DUBs) in the ubiquitination process, we hypothesized that deneddylating enzymes can regulate neuronal development by counteracting the process of neddylation. We find that the SUMO peptidase family member, NEDD8 specific (SENP8) acts as a key neuronal deneddylase targeting the global neuronal substrates in primary rat cultured neurons. We demonstrate that SENP8 expression levels are developmentally regulated, peaking around the first postnatal week and gradually diminishing in mature brain and neurons. We find that SENP8 negatively regulates neurite outgrowth through multiple pathways, including actin dynamics, Wnt/β-catenin signaling, and autophagic processes. Alterations in neurite outgrowth by SENP8 subsequently result in the impairment of excitatory synapse maturation. Our data indicate that SENP8 plays an essential role in neuronal development and is a promising therapeutic target for neurodevelopmental disorders.
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Affiliation(s)
- Jae-Man Song
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Minji Kang
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Seungha Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Jungho Kim
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Sunha Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Da-Ha Park
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Sanghyeon Lee
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
| | - Young Ho Suh
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, South Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea.,Transplantation Research Institute, Seoul National University College of Medicine, Seoul, South Korea
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8
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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.
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Affiliation(s)
| | | | | | | | | | | | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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9
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Molecular Mechanism and Regulation of Autophagy and Its Potential Role in Epilepsy. Cells 2022; 11:cells11172621. [PMID: 36078029 PMCID: PMC9455075 DOI: 10.3390/cells11172621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/14/2022] [Accepted: 08/22/2022] [Indexed: 01/18/2023] Open
Abstract
Autophagy is an evolutionally conserved degradation mechanism for maintaining cell homeostasis whereby cytoplasmic components are wrapped in autophagosomes and subsequently delivered to lysosomes for degradation. This process requires the concerted actions of multiple autophagy-related proteins and accessory regulators. In neurons, autophagy is dynamically regulated in different compartments including soma, axons, and dendrites. It determines the turnover of selected materials in a spatiotemporal control manner, which facilitates the formation of specialized neuronal functions. It is not surprising, therefore, that dysfunctional autophagy occurs in epilepsy, mainly caused by an imbalance between excitation and inhibition in the brain. In recent years, much attention has been focused on how autophagy may cause the development of epilepsy. In this article, we overview the historical landmarks and distinct types of autophagy, recent progress in the core machinery and regulation of autophagy, and biological roles of autophagy in homeostatic maintenance of neuronal structures and functions, with a particular focus on synaptic plasticity. We also discuss the relevance of autophagy mechanisms to the pathophysiology of epileptogenesis.
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10
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Guo R, Xu Y, Xiong W, Wei W, Qi Y, Du Z, Gong S, Tao Z, Liu K. Autophagy-Mediated Synaptic Refinement and Auditory Neural Pruning Contribute to Ribbon Synaptic Maturity in the Developing Cochlea. Front Mol Neurosci 2022; 15:850035. [PMID: 35310883 PMCID: PMC8931412 DOI: 10.3389/fnmol.2022.850035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/28/2022] [Indexed: 11/13/2022] Open
Abstract
In rodents, massive initial synapses are formed in the auditory peripheral nervous system at the early postnatal stage, and one of the major phenomena is that the number of afferent synapses in the cochlea is significantly reduced in the duration of development. This raises the hypothesis that the number of cochlear ribbon synapses are dramatically changed with hearing development and maturation. In this study, several tracers identifying activities of autophagy were applied to estimate the level of autophagy activity in the process of ribbon synapse development in mice; further, changes in the synaptic number and spiral ganglion nerve (SGN) fibers were quantitatively measured. We found robust expression of LC3B and lysosomal-associated membrane protein 1 as well as LysoTracker in or near inner hair cells and cochlear ribbon synapses in the early stage of postnatal development. Moreover, we found a significant loss in the intensity of SGN fibers at ribbon synaptic development and hearing onset. Thus, this study demonstrates that ribbon synaptic refinement and SGN fibers pruning are closely associated with the morphological and functional maturation of ribbon synapses and that synaptic refinement and SGN fiber pruning are regulated by the robust activities of autophagy in the earlier stages of auditory development.
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Affiliation(s)
- Rui Guo
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yice Xu
- Department of Otolaryngology Head and Neck Surgery, Xiaogan Central Hospital, Wuhan University of Science and Technology, Xiaogan, China
| | - Wei Xiong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Wei Wei
- Department of Otology, Shengjing Hospital, China Medical University, Shenyang, China
| | - Yue Qi
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Zhengde Du
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Shusheng Gong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- *Correspondence: Shusheng Gong,
| | - Zezhang Tao
- Department of Otolaryngology Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan, China
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Ke Liu,
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11
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Deneubourg C, Ramm M, Smith LJ, Baron O, Singh K, Byrne SC, Duchen MR, Gautel M, Eskelinen EL, Fanto M, Jungbluth H. The spectrum of neurodevelopmental, neuromuscular and neurodegenerative disorders due to defective autophagy. Autophagy 2022; 18:496-517. [PMID: 34130600 PMCID: PMC9037555 DOI: 10.1080/15548627.2021.1943177] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 06/10/2021] [Indexed: 12/15/2022] Open
Abstract
Primary dysfunction of autophagy due to Mendelian defects affecting core components of the autophagy machinery or closely related proteins have recently emerged as an important cause of genetic disease. This novel group of human disorders may present throughout life and comprises severe early-onset neurodevelopmental and more common adult-onset neurodegenerative disorders. Early-onset (or congenital) disorders of autophagy often share a recognizable "clinical signature," including variable combinations of neurological, neuromuscular and multisystem manifestations. Structural CNS abnormalities, cerebellar involvement, spasticity and peripheral nerve pathology are prominent neurological features, indicating a specific vulnerability of certain neuronal populations to autophagic disturbance. A typically biphasic disease course of late-onset neurodegeneration occurring on the background of a neurodevelopmental disorder further supports a role of autophagy in both neuronal development and maintenance. Additionally, an associated myopathy has been characterized in several conditions. The differential diagnosis comprises a wide range of other multisystem disorders, including mitochondrial, glycogen and lysosomal storage disorders, as well as ciliopathies, glycosylation and vesicular trafficking defects. The clinical overlap between the congenital disorders of autophagy and these conditions reflects the multiple roles of the proteins and/or emerging molecular connections between the pathways implicated and suggests an exciting area for future research. Therapy development for congenital disorders of autophagy is still in its infancy but may result in the identification of molecules that target autophagy more specifically than currently available compounds. The close connection with adult-onset neurodegenerative disorders highlights the relevance of research into rare early-onset neurodevelopmental conditions for much more common, age-related human diseases.Abbreviations: AC: anterior commissure; AD: Alzheimer disease; ALR: autophagic lysosomal reformation; ALS: amyotrophic lateral sclerosis; AMBRA1: autophagy and beclin 1 regulator 1; AMPK: AMP-activated protein kinase; ASD: autism spectrum disorder; ATG: autophagy related; BIN1: bridging integrator 1; BPAN: beta-propeller protein associated neurodegeneration; CC: corpus callosum; CHMP2B: charged multivesicular body protein 2B; CHS: Chediak-Higashi syndrome; CMA: chaperone-mediated autophagy; CMT: Charcot-Marie-Tooth disease; CNM: centronuclear myopathy; CNS: central nervous system; DNM2: dynamin 2; DPR: dipeptide repeat protein; DVL3: disheveled segment polarity protein 3; EPG5: ectopic P-granules autophagy protein 5 homolog; ER: endoplasmic reticulum; ESCRT: homotypic fusion and protein sorting complex; FIG4: FIG4 phosphoinositide 5-phosphatase; FTD: frontotemporal dementia; GBA: glucocerebrosidase; GD: Gaucher disease; GRN: progranulin; GSD: glycogen storage disorder; HC: hippocampal commissure; HD: Huntington disease; HOPS: homotypic fusion and protein sorting complex; HSPP: hereditary spastic paraparesis; LAMP2A: lysosomal associated membrane protein 2A; MEAX: X-linked myopathy with excessive autophagy; mHTT: mutant huntingtin; MSS: Marinesco-Sjoegren syndrome; MTM1: myotubularin 1; MTOR: mechanistic target of rapamycin kinase; NBIA: neurodegeneration with brain iron accumulation; NCL: neuronal ceroid lipofuscinosis; NPC1: Niemann-Pick disease type 1; PD: Parkinson disease; PtdIns3P: phosphatidylinositol-3-phosphate; RAB3GAP1: RAB3 GTPase activating protein catalytic subunit 1; RAB3GAP2: RAB3 GTPase activating non-catalytic protein subunit 2; RB1: RB1-inducible coiled-coil protein 1; RHEB: ras homolog, mTORC1 binding; SCAR20: SNX14-related ataxia; SENDA: static encephalopathy of childhood with neurodegeneration in adulthood; SNX14: sorting nexin 14; SPG11: SPG11 vesicle trafficking associated, spatacsin; SQSTM1: sequestosome 1; TBC1D20: TBC1 domain family member 20; TECPR2: tectonin beta-propeller repeat containing 2; TSC1: TSC complex subunit 1; TSC2: TSC complex subunit 2; UBQLN2: ubiquilin 2; VCP: valosin-containing protein; VMA21: vacuolar ATPase assembly factor VMA21; WDFY3/ALFY: WD repeat and FYVE domain containing protein 3; WDR45: WD repeat domain 45; WDR47: WD repeat domain 47; WMS: Warburg Micro syndrome; XLMTM: X-linked myotubular myopathy; ZFYVE26: zinc finger FYVE-type containing 26.
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Affiliation(s)
- Celine Deneubourg
- Department of Basic and Clinical Neuroscience, IoPPN, King’s College London, London, UK
| | - Mauricio Ramm
- Institute of Biomedicine, University of Turku, Turku, Finland
| | - Luke J. Smith
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King’s College London, London, UK
| | - Olga Baron
- Wolfson Centre for Age-Related Diseases, King’s College London, London, UK
| | - Kritarth Singh
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Susan C. Byrne
- Department of Paediatric Neurology, Neuromuscular Service, Evelina’s Children Hospital, Guy’s & St. Thomas’ Hospital NHS Foundation Trust, London, UK
| | - Michael R. Duchen
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King’s College London, London, UK
| | - Eeva-Liisa Eskelinen
- Institute of Biomedicine, University of Turku, Turku, Finland
- Molecular and Integrative Biosciences Research Programme, University of Helsinki, Helsinki, Finland
| | - Manolis Fanto
- Department of Basic and Clinical Neuroscience, IoPPN, King’s College London, London, UK
| | - Heinz Jungbluth
- Department of Basic and Clinical Neuroscience, IoPPN, King’s College London, London, UK
- Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, King’s College London, London, UK
- Department of Paediatric Neurology, Neuromuscular Service, Evelina’s Children Hospital, Guy’s & St. Thomas’ Hospital NHS Foundation Trust, London, UK
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12
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Lopez ME, Vacio AM, Cantu J, Holgado A. UNC-33L partially rescues life span and locomotion defects in unc-33 mutants but fails to rescue dauer formation defects. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000515. [PMID: 35088044 PMCID: PMC8787492 DOI: 10.17912/micropub.biology.000515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/12/2022] [Accepted: 01/15/2022] [Indexed: 11/29/2022]
Abstract
Herein, we tested the ability of UNC-33L to rescue dauer formation, lifespan, and locomotion defects of unc-33(mn407) mutants. Results show that the presence of UNC-33L does not rescue the defective dauer phenotype in unc-33(mn407) mutants. However, UNC-33L significantly rescued premature death and uncoordinated locomotion in young unc-33(mn407) adults. The degree of UNC-33L-mediated rescue was less noticeable as the nematodes aged, denoting that both age and the presence of UNC-33L interact in the production of the phenotypes.
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Affiliation(s)
- Melissa E Lopez
- Department of Biological Sciences, St. Edward's University, Austin, TX
| | - Arianna M Vacio
- Department of Biological Sciences, St. Edward's University, Austin, TX
| | - Jason Cantu
- Department of Biological Sciences, St. Edward's University, Austin, TX
| | - Andrea Holgado
- Department of Biological Sciences, St. Edward's University, Austin, TX,
Correspondence to: Andrea Holgado ()
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13
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Kitamura N, Fujiwara N, Hayakawa K, Ohama T, Sato K. Protein phosphatase 6 promotes neurite outgrowth by promoting mTORC2 activity in N2a cells. J Biochem 2021; 170:131-138. [PMID: 34314486 DOI: 10.1093/jb/mvab028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/08/2021] [Indexed: 11/14/2022] Open
Abstract
Understanding the molecular mechanism of neuronal differentiation is important to overcome the incurable diseases caused by nervous system damage. Neurite outgrowth is prerequisite for neuronal differentiation and regeneration, and cAMP response element-binding protein (CREB) is one of the major transcriptional factors positively regulating this process. Neuronal differentiation stimuli activate mammalian target of rapamycin (mTOR) complex 2 (mTORC2)/Akt signaling to phosphorylate CREB, however, the precise molecular mechanism of this event has not been fully understood. In this manuscript, we show that neuronal differentiation stimuli increased a protein level of protein phosphatase 6 (PP6), a member of type 2A Ser/Thr protein phosphatases. PP6 knockdown suppressed mTORC2/Akt/CREB signaling and results in failure of neurite outgrowth. SIN1 is a unique component of mTORC2 that enhances mTORC2 activity toward Akt when it is in dephosphorylated form. We found PP6 knockdown increased SIN1 phosphorylation. These data suggest that PP6 may positively regulate neurite outgrowth by dephosphorylating SIN1 to activate mTORC2/Akt/CREB signaling.
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Affiliation(s)
- Nao Kitamura
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | | | - Koji Hayakawa
- Department of Toxicology, Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari, 794-8555 Ehime, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
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14
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Linda K, Lewerissa EI, Verboven AHA, Gabriele M, Frega M, Klein Gunnewiek TM, Devilee L, Ulferts E, Hommersom M, Oudakker A, Schoenmaker C, van Bokhoven H, Schubert D, Testa G, Koolen DA, de Vries BBA, Nadif Kasri N. Imbalanced autophagy causes synaptic deficits in a human model for neurodevelopmental disorders. Autophagy 2021; 18:423-442. [PMID: 34286667 PMCID: PMC8942553 DOI: 10.1080/15548627.2021.1936777] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Macroautophagy (hereafter referred to as autophagy) is a finely tuned process of programmed degradation and recycling of proteins and cellular components, which is crucial in neuronal function and synaptic integrity. Mounting evidence implicates chromatin remodeling in fine-tuning autophagy pathways. However, this epigenetic regulation is poorly understood in neurons. Here, we investigate the role in autophagy of KANSL1, a member of the nonspecific lethal complex, which acetylates histone H4 on lysine 16 (H4K16ac) to facilitate transcriptional activation. Loss-of-function of KANSL1 is strongly associated with the neurodevelopmental disorder Koolen-de Vries Syndrome (KdVS). Starting from KANSL1-deficient human induced-pluripotent stem cells, both from KdVS patients and genome-edited lines, we identified SOD1 (superoxide dismutase 1), an antioxidant enzyme, to be significantly decreased, leading to a subsequent increase in oxidative stress and autophagosome accumulation. In KANSL1-deficient neurons, autophagosome accumulation at excitatory synapses resulted in reduced synaptic density, reduced GRIA/AMPA receptor-mediated transmission and impaired neuronal network activity. Furthermore, we found that increased oxidative stress-mediated autophagosome accumulation leads to increased MTOR activation and decreased lysosome function, further preventing the clearing of autophagosomes. Finally, by pharmacologically reducing oxidative stress, we could rescue the aberrant autophagosome formation as well as synaptic and neuronal network activity in KANSL1-deficient neurons. Our findings thus point toward an important relation between oxidative stress-induced autophagy and synapse function, and demonstrate the importance of H4K16ac-mediated changes in chromatin structure to balance reactive oxygen species- and MTOR-dependent autophagy. Abbreviations: APO: apocynin; ATG: autophagy related; BAF: bafilomycin A1; BSO: buthionine sulfoximine; CV: coefficient of variation; DIV: days in vitro; H4K16ac: histone 4 lysine 16 acetylation; iPSC: induced-pluripotent stem cell; KANSL1: KAT8 regulatory NSL complex subunit 1; KdVS: Koolen-de Vries Syndrome; LAMP1: lysosomal associated membrane protein 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MEA: micro-electrode array; MTOR: mechanistic target of rapamycin kinase; NSL complex: nonspecific lethal complex; 8-oxo-dG: 8-hydroxydesoxyguanosine; RAP: rapamycin; ROS: reactive oxygen species; sEPSCs: spontaneous excitatory postsynaptic currents; SOD1: superoxide dismutase 1; SQSTM1/p62: sequestosome 1; SYN: synapsin; WRT: wortmannin.
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Affiliation(s)
- Katrin Linda
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Elly I Lewerissa
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Anouk H A Verboven
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Michele Gabriele
- Department of Oncology and Haemato-Oncology, University of Milan, Milan, Italy.,Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Monica Frega
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands.,Department of Clinical Neurophysiology, University of Twente, Enschede, The Netherlands
| | - Teun M Klein Gunnewiek
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands.,Department of Anatomy, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, The Netherlands
| | - Lynn Devilee
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Edda Ulferts
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Marina Hommersom
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Astrid Oudakker
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Chantal Schoenmaker
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands.,Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Dirk Schubert
- Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Giuseppe Testa
- Department of Oncology and Haemato-Oncology, University of Milan, Milan, Italy.,Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - David A Koolen
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Bert B A de Vries
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, The Netherlands.,Department of Cognitive Neuroscience, Radboudumc, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
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15
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Beckers A, Vanhunsel S, Van Dyck A, Bergmans S, Masin L, Moons L. Injury-induced Autophagy Delays Axonal Regeneration after Optic Nerve Damage in Adult Zebrafish. Neuroscience 2021; 470:52-69. [PMID: 34280491 DOI: 10.1016/j.neuroscience.2021.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/18/2021] [Accepted: 07/09/2021] [Indexed: 12/15/2022]
Abstract
Optic neuropathies comprise a group of disorders in which the axons of retinal ganglion cells (RGCs), the retinal projection neurons conveying visual information to the brain, are damaged. This results in visual impairment or even blindness, which is irreversible as adult mammals lack the capacity to repair or replace injured or lost neurons. Despite intensive research, no efficient treatment to induce axonal regeneration in the central nervous system (CNS) is available yet. Autophagy, the cellular recycling response, was shown repeatedly to be elevated in animal models of optic nerve injury, and both beneficial and detrimental effects have been reported. In this study, we subjected spontaneously regenerating adult zebrafish to optic nerve damage (ONC) and revealed that autophagy is enhanced after optic nerve damage in zebrafish, both in RGC axons and somas, as well as in macroglial cells of the retina, the optic nerve and the visual target areas in the brain. Interestingly, the pattern of the autophagic response in the axons followed the spatiotemporal window of axonal regrowth, which suggests that autophagy is ongoing at the growth cones. Pharmacological inhibition of the recycling pathway resulted in accelerated RGC target reinnervation, possibly linked to increased mechanistic target of rapamycin (mTOR) activity, known to stimulate axonal regrowth. Taken together, these intriguing findings underline that further research is warranted to decipher if modulation of autophagy could be an effective therapeutic method to induce CNS regeneration.
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Affiliation(s)
- An Beckers
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Sophie Vanhunsel
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Annelies Van Dyck
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Steven Bergmans
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Luca Masin
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lieve Moons
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium; Leuven Brain Institute, 3000 Leuven, Belgium.
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16
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Lee CY, Hyun SA, Ko MY, Kim HR, Rho J, Kim KK, Kim WY, Ka M. Maternal Bisphenol A (BPA) Exposure Alters Cerebral Cortical Morphogenesis and Synaptic Function in Mice. Cereb Cortex 2021; 31:5598-5612. [PMID: 34171088 DOI: 10.1093/cercor/bhab183] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 12/15/2022] Open
Abstract
Early-life exposure to bisphenol A (BPA), synthetic compound used in polycarbonate plastic, is associated with altered cognitive and emotional behavior later in life. However, the brain mechanism underlying the behavioral deficits is unknown. Here, we show that maternal BPA exposure disrupted self-renewal and differentiation of neural progenitors during cortical development. The BPA exposure reduced the neuron number, whereas it increased glial cells in the cerebral cortex. Also, synaptic formation and transmission in the cerebral cortex were suppressed after maternal BPA exposure. These changes appeared to be associated with autophagy as a gene ontology analysis of RNA-seq identified an autophagy domain in the BPA condition. Mouse behavioral tests revealed that maternal BPA caused hyperactivity and social deficits in adult offspring. Together, these results suggest that maternal BPA exposure leads to abnormal cortical architecture and function likely by activating autophagy.
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Affiliation(s)
- Chang Youn Lee
- Substance Abuse Pharmacology Group, Korea Institute of Toxicology, KRICT, Daejeon 34114, Republic of Korea
| | - Sung-Ae Hyun
- Substance Abuse Pharmacology Group, Korea Institute of Toxicology, KRICT, Daejeon 34114, Republic of Korea.,Department of Biochemistry, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Moon Yi Ko
- Substance Abuse Pharmacology Group, Korea Institute of Toxicology, KRICT, Daejeon 34114, Republic of Korea.,Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Hye Ryeong Kim
- Substance Abuse Pharmacology Group, Korea Institute of Toxicology, KRICT, Daejeon 34114, Republic of Korea
| | - Jaerang Rho
- Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Kee K Kim
- Department of Biochemistry, Chungnam National University, Daejeon 34134, Republic of Korea
| | - Woo-Yang Kim
- Department of Biological Sciences, Kent State University, Kent, OH 44242, USA
| | - Minhan Ka
- Substance Abuse Pharmacology Group, Korea Institute of Toxicology, KRICT, Daejeon 34114, Republic of Korea
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17
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Behrendt L, Hoischen C, Kaether C. Disease-causing mutated ATLASTIN 3 is excluded from distal axons and reduces axonal autophagy. Neurobiol Dis 2021; 155:105400. [PMID: 34019998 DOI: 10.1016/j.nbd.2021.105400] [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: 01/07/2021] [Revised: 04/27/2021] [Accepted: 05/16/2021] [Indexed: 10/21/2022] Open
Abstract
Mutations in the ER-network forming GTPase atlastin3 (ATL3) can cause axon degeneration of sensory neurons by not fully understood mechanisms. We here show that the hereditary sensory and autonomous neuropathy (HSAN)-causing ATL3 Y192C or P338R are excluded from distal axons by a barrier at the axon initial segment (AIS). This barrier is selective for mutated ATL3, but not wildtype ATL3 or unrelated ER-membrane proteins. Actin-depolymerization partially restores the transport of ATL3 Y192C into distal axons. The results point to the existence of a selective diffusion barrier in the ER membrane at the AIS, analogous to the AIS-based barriers for plasma membrane and cytosolic proteins. Functionally, the absence of ATL3 at the distal axon reduces axonal autophagy and the ER network deformation in the soma causes a reduction in axonal lysosomes. Both could contribute to axonal degeneration and eventually to HSAN.
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Affiliation(s)
- Laura Behrendt
- Leibniz-Institut für Alternsforschung-Fritz-Lipmann-Institut, 07745 Jena, Germany
| | - Christian Hoischen
- Leibniz-Institut für Alternsforschung-Fritz-Lipmann-Institut, 07745 Jena, Germany
| | - Christoph Kaether
- Leibniz-Institut für Alternsforschung-Fritz-Lipmann-Institut, 07745 Jena, Germany.
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18
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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.
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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.
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19
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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.
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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
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20
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Ribas VT, Vahsen BF, Tatenhorst L, Estrada V, Dambeck V, Almeida RA, Bähr M, Michel U, Koch JC, Müller HW, Lingor P. AAV-mediated inhibition of ULK1 promotes axonal regeneration in the central nervous system in vitro and in vivo. Cell Death Dis 2021; 12:213. [PMID: 33637688 PMCID: PMC7910615 DOI: 10.1038/s41419-021-03503-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/12/2021] [Accepted: 01/15/2021] [Indexed: 01/31/2023]
Abstract
Axonal damage is an early step in traumatic and neurodegenerative disorders of the central nervous system (CNS). Damaged axons are not able to regenerate sufficiently in the adult mammalian CNS, leading to permanent neurological deficits. Recently, we showed that inhibition of the autophagic protein ULK1 promotes neuroprotection in different models of neurodegeneration. Moreover, we demonstrated previously that axonal protection improves regeneration of lesioned axons. However, whether axonal protection mediated by ULK1 inhibition could also improve axonal regeneration is unknown. Here, we used an adeno-associated viral (AAV) vector to express a dominant-negative form of ULK1 (AAV.ULK1.DN) and investigated its effects on axonal regeneration in the CNS. We show that AAV.ULK1.DN fosters axonal regeneration and enhances neurite outgrowth in vitro. In addition, AAV.ULK1.DN increases neuronal survival and enhances axonal regeneration after optic nerve lesion, and promotes long-term axonal protection after spinal cord injury (SCI) in vivo. Interestingly, AAV.ULK1.DN also increases serotonergic and dopaminergic axon sprouting after SCI. Mechanistically, AAV.ULK1.DN leads to increased ERK1 activation and reduced expression of RhoA and ROCK2. Our findings outline ULK1 as a key regulator of axonal degeneration and regeneration, and define ULK1 as a promising target to promote neuroprotection and regeneration in the CNS.
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Affiliation(s)
- Vinicius Toledo Ribas
- Department of Morphology, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Belo Horizonte, 31270-901, Brazil.
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany.
| | - Björn Friedhelm Vahsen
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Lars Tatenhorst
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Von-Siebold-Straße 3a, 37075, Göttingen, Germany
- DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Veronica Estrada
- Molecular Neurobiology Laboratory, Department of Neurology, Heinrich-Heine-University Medical Center Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany
| | - Vivian Dambeck
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Von-Siebold-Straße 3a, 37075, Göttingen, Germany
- DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Raquel Alves Almeida
- Department of Morphology, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Belo Horizonte, 31270-901, Brazil
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Uwe Michel
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Jan Christoph Koch
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Hans Werner Müller
- Molecular Neurobiology Laboratory, Department of Neurology, Heinrich-Heine-University Medical Center Düsseldorf, Moorenstraße 5, 40225, Düsseldorf, Germany
| | - Paul Lingor
- Department of Neurology, University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), University Medical Center Göttingen, Von-Siebold-Straße 3a, 37075, Göttingen, Germany
- DFG Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medical Center Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
- Department of Neurology, Rechts der Isar Hospital of the Technical University Munich, Ismaninger Straße 22, 81675, Munich, Germany
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Axonal Organelles as Molecular Platforms for Axon Growth and Regeneration after Injury. Int J Mol Sci 2021; 22:ijms22041798. [PMID: 33670312 PMCID: PMC7918155 DOI: 10.3390/ijms22041798] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
Investigating the molecular mechanisms governing developmental axon growth has been a useful approach for identifying new strategies for boosting axon regeneration after injury, with the goal of treating debilitating conditions such as spinal cord injury and vision loss. The picture emerging is that various axonal organelles are important centers for organizing the molecular mechanisms and machinery required for growth cone development and axon extension, and these have recently been targeted to stimulate robust regeneration in the injured adult central nervous system (CNS). This review summarizes recent literature highlighting a central role for organelles such as recycling endosomes, the endoplasmic reticulum, mitochondria, lysosomes, autophagosomes and the proteasome in developmental axon growth, and describes how these organelles can be targeted to promote axon regeneration after injury to the adult CNS. This review also examines the connections between these organelles in developing and regenerating axons, and finally discusses the molecular mechanisms within the axon that are required for successful axon growth.
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22
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Autophagy and Redox Homeostasis in Parkinson's: A Crucial Balancing Act. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:8865611. [PMID: 33224433 PMCID: PMC7671810 DOI: 10.1155/2020/8865611] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/23/2020] [Accepted: 10/14/2020] [Indexed: 12/13/2022]
Abstract
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated primarily from endogenous biochemical reactions in mitochondria, endoplasmic reticulum (ER), and peroxisomes. Typically, ROS/RNS correlate with oxidative damage and cell death; however, free radicals are also crucial for normal cellular functions, including supporting neuronal homeostasis. ROS/RNS levels influence and are influenced by antioxidant systems, including the catabolic autophagy pathways. Autophagy is an intracellular lysosomal degradation process by which invasive, damaged, or redundant cytoplasmic components, including microorganisms and defunct organelles, are removed to maintain cellular homeostasis. This process is particularly important in neurons that are required to cope with prolonged and sustained operational stress. Consequently, autophagy is a primary line of protection against neurodegenerative diseases. Parkinson's is caused by the loss of midbrain dopaminergic neurons (mDANs), resulting in progressive disruption of the nigrostriatal pathway, leading to motor, behavioural, and cognitive impairments. Mitochondrial dysfunction, with associated increases in oxidative stress, and declining proteostasis control, are key contributors during mDAN demise in Parkinson's. In this review, we analyse the crosstalk between autophagy and redoxtasis, including the molecular mechanisms involved and the detrimental effect of an imbalance in the pathogenesis of Parkinson's.
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Adnan G, Rubikaite A, Khan M, Reber M, Suetterlin P, Hindges R, Drescher U. The GTPase Arl8B Plays a Principle Role in the Positioning of Interstitial Axon Branches by Spatially Controlling Autophagosome and Lysosome Location. J Neurosci 2020; 40:8103-8118. [PMID: 32917789 PMCID: PMC7574663 DOI: 10.1523/jneurosci.1759-19.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 07/13/2020] [Accepted: 07/20/2020] [Indexed: 12/12/2022] Open
Abstract
Interstitial axon branching is an essential step during the establishment of neuronal connectivity. However, the exact mechanisms on how the number and position of branches are determined are still not fully understood. Here, we investigated the role of Arl8B, an adaptor molecule between lysosomes and kinesins. In chick retinal ganglion cells (RGCs), downregulation of Arl8B reduces axon branch density and shifts their location more proximally, while Arl8B overexpression leads to increased density and more distal positions of branches. These alterations correlate with changes in the location and density of lysosomes and autophagosomes along the axon shaft. Diminishing autophagy directly by knock-down of atg7, a key autophagy gene, reduces branch density, while induction of autophagy by rapamycin increases axon branching, indicating that autophagy plays a prominent role in axon branch formation. In vivo, local inactivation of autophagy in the retina using a mouse conditional knock-out approach disturbs retino-collicular map formation which is dependent on the formation of interstitial axon branches. These data suggest that Arl8B plays a principal role in the positioning of axon branches by spatially controlling autophagy, thus directly controlling formation of neural connectivity in the brain.SIGNIFICANCE STATEMENT The formation of interstitial axonal branches plays a prominent role in numerous places of the developing brain during neural circuit establishment. We show here that the GTPase Arl8B controls density and location of interstitial axon branches, and at the same time controls also density and location of the autophagy machinery. Upregulation or downregulation of autophagy in vitro promotes or inhibits axon branching. Local disruption of autophagy in vivo disturbs retino-collicular mapping. Our data suggest that Arl8B controls axon branching by controlling locally autophagy. This work is one of the first reports showing a role of autophagy during early neural circuit development and suggests that autophagy in general plays a much more prominent role during brain development than previously anticipated.
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Affiliation(s)
- Gee Adnan
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | - Aine Rubikaite
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | - Moqadisa Khan
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | - Michael Reber
- Krembil Research Institute, Toronto, Ontario M5T 0S8, Canada
| | - Philip Suetterlin
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
- Craniofacial Development and Stem Cell Biology, King's College London, Guy's Hospital, London SE1 9RT, United Kingdom
| | - Robert Hindges
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, United Kingdom
| | - Uwe Drescher
- Centre for Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, United Kingdom
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Loddo S, Alesi V, Radio FC, Genovese S, Di Tommaso S, Calvieri G, Orlando V, Bertini E, Dentici ML, Novelli A, Dallapiccola B. PPP1R21-related syndromic intellectual disability: Report of an adult patient and review. Am J Med Genet A 2020; 182:3014-3022. [PMID: 32985083 DOI: 10.1002/ajmg.a.61889] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/07/2020] [Accepted: 09/07/2020] [Indexed: 11/09/2022]
Abstract
Variants in PPP1R21 were recently found to be associated with an autosomal recessive intellectual disability syndrome in 9 individuals. Our patient, the oldest among the known subjects affected by PPP1R21-related syndrome, manifested intellectual disability, short stature, congenital ataxia with cerebellar vermis hypoplasia, generalized hypertrichosis, ulcerative keratitis, muscle weakness, progressive coarse appearance, macroglossia with fissured tongue, and deep palmar and plantar creases. We provide an overview of the clinical spectrum and natural history of this newly recognized disorder, arguing the emerging notion that PPP1R21 gene mutations could result in endolysosomal functional defects. The oldest patients could display a more severe clinical outcome, due to accumulation of metabolites or damage secondary to an alteration of the autophagy pathway. Follow-up of patients with PPP1R21 mutations is recommended for improving the understanding of PPP1R21-related syndromic intellectual disability.
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Affiliation(s)
- Sara Loddo
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Viola Alesi
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Silvia Genovese
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Silvia Di Tommaso
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Giusy Calvieri
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Valeria Orlando
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Enrico Bertini
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.,Neuromuscular and Neurodegenerative Disorders Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Maria Lisa Dentici
- Medical Genetics Unit, Academic Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Bruno Dallapiccola
- Scientific Directorate, Bambino Gesù Pediatric Hospital, IRCCS, Rome, Italy
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Hill SE, Colón-Ramos DA. The Journey of the Synaptic Autophagosome: A Cell Biological Perspective. Neuron 2020; 105:961-973. [PMID: 32191859 DOI: 10.1016/j.neuron.2020.01.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 12/23/2019] [Accepted: 01/14/2020] [Indexed: 01/13/2023]
Abstract
Autophagy is a key cellular degradative pathway, important for neuronal homeostasis and function. Disruption of autophagy is associated with neuronal dysfunction and neurodegeneration. Autophagy is compartmentalized in neurons, with specific stages of the pathway occurring in distinct subcellular compartments. Coordination of these stages drives progression of autophagy and enables clearance of substrates. Yet, we are only now learning how these distributed processes are integrated across the neuron. In this review, we focus on the cell biological course of autophagy in neurons, from biogenesis at the synapse to degradation in the soma. We describe how the steps of autophagy are distributed across neuronal subcellular compartments, how local machinery regulates autophagy, and the impact of coordinated regulation on neuronal physiology and disease. We also discuss how recent advances in our understanding of neuronal autophagic mechanisms have reframed how we think about the role of local regulation of autophagy in all tissues.
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Affiliation(s)
- Sarah E Hill
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, PO Box 9812, New Haven, CT 06536-0812, USA; Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA
| | - Daniel A Colón-Ramos
- Department of Neuroscience and Department of Cell Biology, Yale University School of Medicine, PO Box 9812, New Haven, CT 06536-0812, USA; Instituto de Neurobiología José del Castillo, Universidad de Puerto Rico, San Juan, PR, USA.
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26
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Zhu X, Wu S, Zeng W, Chen X, Zheng T, Ren J, Ke M. Protective Effects of Rapamycin on Trabecular Meshwork Cells in Glucocorticoid-Induced Glaucoma Mice. Front Pharmacol 2020; 11:1006. [PMID: 32714192 PMCID: PMC7344368 DOI: 10.3389/fphar.2020.01006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/22/2020] [Indexed: 12/12/2022] Open
Abstract
Glucocorticoid-induced glaucoma (GIG) is a chronic optic neuropathy caused by systemic or topical glucocorticoid (GC) treatment, which could eventually lead to permanent vision loss. To investigate the protective effects of rapamycin (RAP) on the trabecular cells during the development of GIG in mice, the effects of RAP on intraocular pressure (IOP), trabecular ultrastructure, and retinal ganglion cells (RGCs) were examined in C57BL/6J female mice treated with dexamethasone acetate (Dex-Ace). The expression of α-actin in trabecular tissue was detected by immunofluorescence, and the autophagic activity of trabecular cells and the expression of GIG-related myocilin and α-actin were detected by immunoblotting. Our results indicated that Dex-Ace significantly increased IOP at the end of the third week (p < 0.05), while RAP treatment neutralized this elevation of IOP by Dex-Ace. Dex-Ace treatment significantly decreased the RGC numbers (p < 0.05), while synchronous RAP treatment kept the number comparable to control. The outer sheath of elastic fibers became thicker and denser, and the mitochondria of lesions increased in Dex-Ace-treated groups at 4 weeks, while no significant change was observed in the RAP-treated trabecular tissues. Dex-Ace induced myocilin, α-actin, Beclin-1, and LC3-II/LC-I ratio, and lowered p62, while synchronous RAP treatment further activated autophagy and neutralized the induction of myocilin and α-actin. Our studies suggested that RAP protected trabecular meshwork cells by further inducing autophagy way from damages of GC treatment.
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Affiliation(s)
- Xiaolu Zhu
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Shengyu Wu
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Wen Zeng
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xiaomin Chen
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Tian Zheng
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jiangbo Ren
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Min Ke
- Department of Ophthalmology, Zhongnan Hospital of Wuhan University, Wuhan, China
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27
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Ligon C, Seong E, Schroeder EJ, DeKorver NW, Yuan L, Chaudoin TR, Cai Y, Buch S, Bonasera SJ, Arikkath J. δ-Catenin engages the autophagy pathway to sculpt the developing dendritic arbor. J Biol Chem 2020; 295:10988-11001. [PMID: 32554807 DOI: 10.1074/jbc.ra120.013058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/14/2020] [Indexed: 01/21/2023] Open
Abstract
The development of the dendritic arbor in pyramidal neurons is critical for neural circuit function. Here, we uncovered a pathway in which δ-catenin, a component of the cadherin-catenin cell adhesion complex, promotes coordination of growth among individual dendrites and engages the autophagy mechanism to sculpt the developing dendritic arbor. Using a rat primary neuron model, time-lapse imaging, immunohistochemistry, and confocal microscopy, we found that apical and basolateral dendrites are coordinately sculpted during development. Loss or knockdown of δ-catenin uncoupled this coordination, leading to retraction of the apical dendrite without altering basolateral dendrite dynamics. Autophagy is a key cellular pathway that allows degradation of cellular components. We observed that the impairment of the dendritic arbor resulting from δ-catenin knockdown could be reversed by knockdown of autophagy-related 7 (ATG7), a component of the autophagy machinery. We propose that δ-catenin regulates the dendritic arbor by coordinating the dynamics of individual dendrites and that the autophagy mechanism may be leveraged by δ-catenin and other effectors to sculpt the developing dendritic arbor. Our findings have implications for the management of neurological disorders, such as autism and intellectual disability, that are characterized by dendritic aberrations.
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Affiliation(s)
- Cheryl Ligon
- Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Eunju Seong
- Developmental Neuroscience, Munroe-Meyer Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ethan J Schroeder
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Nicholas W DeKorver
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Li Yuan
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Tammy R Chaudoin
- Division of Geriatrics, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Yu Cai
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Stephen J Bonasera
- Division of Geriatrics, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jyothi Arikkath
- Department of Anatomy, Howard University, Washington, D. C., USA
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28
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Ligon C, Cai Y, Buch S, Arikkath J. A selective role for a component of the autophagy pathway in coupling the Golgi apparatus to dendrite polarity in pyramidal neurons. Neurosci Lett 2020; 730:135048. [PMID: 32439477 DOI: 10.1016/j.neulet.2020.135048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/01/2020] [Accepted: 05/07/2020] [Indexed: 12/11/2022]
Abstract
Pyramidal neurons have a characteristic morphology that is critical to their ability to integrate into functional neural circuits. In addition to axon dendrite polarity, pyramidal neurons also exhibit dendritic polarity such that apical and basolateral dendrites differ in size, structure and inputs. Dendrite polarity in pyramidal neurons coincides with polarity of the Golgi apparatus, a key feature relevant to directed secretory trafficking, both in vitro and in vivo. We identify a novel autophagy based mechanism that uncouples the polarity of the Golgi apparatus from dendrite polarity. Autophagy is a universal cellular pathway that promotes cellular homeostasis via degradation of cellular components. Our data indicate that knockdown of ATG7, a key component of the autophagy mechanism, disrupts the polarity of the Golgi apparatus without impacting dendritic polarity in primary pyramidal neurons, providing the first evidence that dendrite polarity can be uncoupled from Golgi polarity. Interestingly, these effects are restricted to ATG7 knockdown and are not replicated by the knockdown of ATG16L1, another component of the autophagy mechanism. We propose that cellular mechanisms exist to couple Golgi polarity to dendrite polarity. Components of the autophagy mechanism are leveraged to actively couple Golgi polarity to dendrite polarity, thus impacting secretory trafficking into individual dendrites in pyramidal neurons.
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Affiliation(s)
- Cheryl Ligon
- Developmental Neuroscience, Munroe-Meyer Institute, United States
| | - Yu Cai
- Department of Pharmacology and Experimental Neuroscience University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Shilpa Buch
- Department of Pharmacology and Experimental Neuroscience University of Nebraska Medical Center, Omaha, NE, 68198, United States
| | - Jyothi Arikkath
- Department of Anatomy, Howard University, Washington D.C, 20059, United States.
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29
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Joshi V, Upadhyay A, Prajapati VK, Mishra A. How autophagy can restore proteostasis defects in multiple diseases? Med Res Rev 2020; 40:1385-1439. [PMID: 32043639 DOI: 10.1002/med.21662] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 01/03/2020] [Accepted: 01/28/2020] [Indexed: 12/12/2022]
Abstract
Cellular evolution develops several conserved mechanisms by which cells can tolerate various difficult conditions and overall maintain homeostasis. Autophagy is a well-developed and evolutionarily conserved mechanism of catabolism, which endorses the degradation of foreign and endogenous materials via autolysosome. To decrease the burden of the ubiquitin-proteasome system (UPS), autophagy also promotes the selective degradation of proteins in a tightly regulated way to improve the physiological balance of cellular proteostasis that may get perturbed due to the accumulation of misfolded proteins. However, the diverse as well as selective clearance of unwanted materials and regulations of several cellular mechanisms via autophagy is still a critical mystery. Also, the failure of autophagy causes an increase in the accumulation of harmful protein aggregates that may lead to neurodegeneration. Therefore, it is necessary to address this multifactorial threat for in-depth research and develop more effective therapeutic strategies against lethal autophagy alterations. In this paper, we discuss the most relevant and recent reports on autophagy modulations and their impact on neurodegeneration and other complex disorders. We have summarized various pharmacological findings linked with the induction and suppression of autophagy mechanism and their promising preclinical and clinical applications to provide therapeutic solutions against neurodegeneration. The conclusion, key questions, and future prospectives sections summarize fundamental challenges and their possible feasible solutions linked with autophagy mechanism to potentially design an impactful therapeutic niche to treat neurodegenerative diseases and imperfect aging.
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Affiliation(s)
- Vibhuti Joshi
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Karwar, India
| | - Arun Upadhyay
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Karwar, India
| | - Vijay K Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Karwar, India
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30
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Xiong W, Wei W, Qi Y, Du Z, Qu T, Liu K, Gong S. Autophagy is Required for Remodeling in Postnatal Developing Ribbon Synapses of Cochlear Inner Hair Cells. Neuroscience 2020; 431:1-16. [PMID: 32032574 DOI: 10.1016/j.neuroscience.2020.01.032] [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] [Received: 10/18/2019] [Revised: 01/13/2020] [Accepted: 01/19/2020] [Indexed: 11/16/2022]
Abstract
Cochlear ribbon synapses formed between inner hair cells (IHCs) and spiral ganglion neurons (SGNs) are immature at birth and they require dramatic morphological and functional developments to achieve auditory maturation in postnatal mice. However, the mechanism underlying this remodeling process of cochlear ribbon synapse remains elusive. Here, we report that autophagy is necessary for the development and maturation of cochlear ribbon synapses in mice. In this study, significantly high levels of LC3B (a widespread marker of autophagy) were found in the cochlea from postnatal day 1 (P1) to P15, which then decreased at P28 to P30. Treatment of mice at P7 with rapamycin or 3-methyladenine (activator and inhibitor of autophagy, respectively) for 7 days led to the significant elevations of hearing threshold across frequencies from P15 to P30. Moreover, abnormal morphology of cochlear ribbon synapses and reduced IHC exocytosis function were detected from P15 to P30, which were likely associated to hearing impairment. Thus, our study demonstrated that autophagy was required for remodeling of cochlear ribbon synapses and provided a new insight into autophagy-related hearing disorder during auditory development. Furthermore, we implicated a novel therapeutic target for sensorineural hearing loss.
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Affiliation(s)
- Wei Xiong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Wei Wei
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Yue Qi
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Zhengde Du
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Tengfei Qu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
| | - Ke Liu
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
| | - Shusheng Gong
- Department of Otolaryngology Head and Neck Surgery, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
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Ko SH, Apple EC, Liu Z, Chen L. Age-dependent autophagy induction after injury promotes axon regeneration by limiting NOTCH. Autophagy 2020; 16:2052-2068. [PMID: 31920157 DOI: 10.1080/15548627.2020.1713645] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Macroautophagy/autophagy is essential for maintaining cellular homeostasis through the degradation of organelles and proteins. It also has a prominent role in modulating aging. However, the role of autophagy in the neuronal response to axon injury and axon regeneration, particularly in the context of aging, remains largely unknown. Our candidate genetic screen for axon regeneration regulators has identified genes in the autophagy pathway. Using a reporter that monitors autophagosomes and autolysosomes, we were able to monitor the dynamics of autophagy during axon regeneration. In response to axon injury, there was a significant increase in the number of autophagic vesicles. Injury-triggered autophagy activation and axon regeneration capacity undergo an age-dependent decline, and autophagy-activating agents partially rescued these declines. We found that DLK-1 was both required and sufficient for injury-induced autophagy activation. Autophagic vesicles co-localized with the NOTCH4 ortholog, LIN-12 receptor, a previously identified inhibitor of axon regeneration. Epistasis analyses indicate that LIN-12 might be a target of autophagy in axon regeneration. Together, our data suggest that DLK-mediated injury signaling can activate autophagy, which might limit the level of LIN-12 and NOTCH proteins to promote axon regeneration. Our findings reveal that autophagy activation can promote axon regeneration in neurons that lack maximal regrowth capacity, providing a promising therapeutic strategy for axon injury. Abbreviations: 3-MA: 3-methyladenine; ALs: autolysosomes; APs: autophagosomes; ARF-6: ADP-Ribosylation Factor related 6; ATG-9: AuTophaGy (yeast Atg homolog) 9; ATG9A: autophagy related 9A; BA1: bafilomycin A1; BEC-1: BEClin (human autophagy) homolog; BECN1: beclin 1; C. elegans: Caenorhabditis elegans; CEBP-1: C/EBP (CCAAT/enhancer-binding protein) homolog; CNS: central nervous system; DLK-1: Dual-Leucine zipper Kinase; DMSO: dimethyl sulfoxide; DRG: dorsal root ganglion; FOS: Fos proto-oncogene, AP-1 transcription factor subunit; GABA: gamma-aminobutyric acid; GFP: green fluorescent protein; HDA-3: Histone DeAcetylase; IP3: inositol trisphosphate; ITR-1: Inositol Triphosphate Receptor; KLF-2: Kruppel-Like Factor (zinc finger protein) 2; LGG-1: LC3, GABARAP and GATE-16 family; MAK-2: MAP kinase Activated protein Kinase; MAP kinase: mitogen-activated protein kinase; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MKK-4: mitogen activated protein kinase kinase 4; MTOR: mechanistic target of rapamycin kinase; NGM: nematode growth medium; NICD: Notch intracellular domain; NOTCH: notch receptor; PLM: posterior lateral microtubule; PMK-3: P38 Map kinase family; PNS: peripheral nervous system; SCG10: superior cervical ganglion protein 10; SCI: spinal cord injury; UNC-51: UNCoordinated 51; ULK1: unc-51 like autophagy activating kinase 1; wnd: wallenda.
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Affiliation(s)
- Su-Hyuk Ko
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Ellen C Apple
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Zhijie Liu
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Lizhen Chen
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
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32
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Lv M, Ma Q. Autophagy in Neurodevelopmental Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1207:171-182. [PMID: 32671746 DOI: 10.1007/978-981-15-4272-5_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neurodevelopmental diseases are a class of neurodevelopmental disorders characterized by cognitive impairment and behavioral abnormalities and are mainly manifested as developmental disorders of the brain and nervous system. The pathological mechanism is not fully understood and may be related to hereditary or environmental factors. The elevation of autophagy during neural development suggests that autophagy may be involved in the process of neurodevelopment. This chapter focuses on the important functions of autophagy in all aspects of neurodevelopment and the role and mechanism of autophagy in neurodevelopmental disorders, especially in autism spectrum disorder.
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Affiliation(s)
- Meihong Lv
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu Province, China
| | - Quanhong Ma
- Institute of Neuroscience, Soochow University, Suzhou, Jiangsu Province, China.
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Granule of BU-XIN RUAN-MAI Attenuates the Patients' Angina Pectoris of Coronary Heart Disease via Regulating miR-542-3p/GABARAP Signaling. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:1808419. [PMID: 31949464 PMCID: PMC6948311 DOI: 10.1155/2019/1808419] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/15/2019] [Accepted: 10/23/2019] [Indexed: 12/22/2022]
Abstract
Objective Coronary heart disease (CHD) has been regarded as a serious and common disease in the modern society. This study aims to investigate the effect of Granule of BU-XIN RUAN-MAI (BXRM) on angina pectoris of coronary heart disease and to explore the molecular mechanisms underlying Granule of BU-XIN RUAN-MAI-mediated protective activity against this disease. Methods The effects of Granule of BU-XIN RUAN-MAI on clinical symptoms of patients' angina were indicated by hemorheology indicators including high shear of blood viscosity, low shear of blood viscosity, plasma viscosity, erythrocyte rigidity index, D-D dimer, fibrinogen content, and lipid content. The effects of Granule of BU-XIN RUAN-MAI on isoprenaline-induced myocardial cell injury were determined by conducting H&E staining and by performing ELISA to examine the serum content of MDA, SOD, Na+/K+-ATPase, cAMP, and the content of inflammatory factors in isoprenaline-induced rats. Meanwhile, western blot and real time PCR were used to determine the expression of genes involved in oxidation and energy metabolism, and real time PCR was also used for determination of miR-542-3p expression. Luciferase reporter assay was conducted to test the binding sites of miR-542-3p on GABARAP 3'UTR. The chemical compositions of Granule of BU-XIN RUAN-MAI were determined by liquid LC-QTOF-MS. Results Granule of BU-XIN RUAN-MAI significantly attenuated the clinical symptoms of patients' angina by improving the patients' heart rate and by decreasing the level of hemorheology indicators and also by reducing the serum content of TC, TG, LDL, and elevated HDL content. H&E staining demonstrated that Granule of BU-XIN RUAN-MAI ameliorated the myocardial ischemia in a dose-dependent manner. Besides, Granule of BU-XIN RUAN-MAI downregulated serum MDA content and upregulated the content of SOD, Na+/K+-ATPase, and cAMP in isoprenaline-induced rats. Granule of BU-XIN RUAN-MAI significantly improved oxidation stress by increasing PPARα expression, and it inhibited inflammation by downregulating expression and contents of IL-6, IL-1β, and TNF-α. Then, Granule of BU-XIN RUAN-MAI-containing serum increased the SOD content, and reduced the MDA content in angiotensin II-stimulated HUVEC cells. The granule of BU-XIN RUAN-MAI-containing serum obviously downregulated protein expressions of P40phox, P47phox, and P67phox in plasma membrane, and it significantly increased protein levels of P40phox, P47phox, and P67phox in the cytoplasm of HUVEC cells. Furthermore, GABARAP was reduced in heart tissues of ISO-induced rats and in angiotensin II-stimulated cell lines, and GABARAP was required for the inhibitory activity of Granule of BU-XIN RUAN-MAI on oxidation and inflammation in vivo and in vivo. GABARAP could be upregulated by Granule of BU-XIN RUAN-MAI by inhibiting the expression of miR-542-3p, which may significantly enhance oxidation and inflammation by targeting GABARAP in cardiomyocytes. Moreover, the silencing of GABARAP could obviously reverse the granule of BU-XIN RUAN-MAI-mediated protective activity against coronary heart disease, and interfering GABARAP expression also could partly block the anti-miR-542-3p-controlled oxidation and inflammation in cardiomyocytes. Besides, salidroside, loganin, and polydatin were the main compounds of granules of BU-XIN RUAN-MAI. Conclusion Granule of BU-XIN RUAN-MAI is an excellent prescription for treatment of coronary heart disease by suppressing inflammation and NAPDH-mediated oxidative stress. The miR-542-3p/GABARAP axis is required for Granule of BU-XIN RUAN-MAI, exhibiting its protective activity against the pectoris of coronary heart disease.
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An autism-causing calcium channel variant functions with selective autophagy to alter axon targeting and behavior. PLoS Genet 2019; 15:e1008488. [PMID: 31805042 PMCID: PMC6894750 DOI: 10.1371/journal.pgen.1008488] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 10/21/2019] [Indexed: 11/22/2022] Open
Abstract
Common and rare variants of the CACNA1C voltage-gated calcium channel gene have been associated with autism and other neurodevelopmental disorders including schizophrenia, bipolar disorder and ADHD. However, little is known about how CACNA1C variants affect cellular processes to alter neurodevelopment. The Timothy syndrome mutation is a rare de novo gain-of-function variant in CACNA1C that causes autism with high penetrance, providing a powerful avenue into investigating the role of CACNA1C variants in neurodevelopmental disorders. Here, we use egl-19, the C. elegans homolog of CACNA1C, to investigate the role of voltage-gated calcium channels in autism. We show that an egl-19(gof) mutation that is equivalent to the Timothy syndrome mutation can alter axon targeting and affect behavior in C. elegans. We find that wildtype egl-19 negatively regulates axon termination. The egl-19(gof) mutation represses axon termination to cause axon targeting defects that lead to the misplacement of electrical synapses and alterations in habituation to light touch. Moreover, genetic interactions indicate that the egl-19(gof) mutation functions with genes that promote selective autophagy to cause defects in axon termination and behavior. These results reveal a novel genetic mechanism whereby a de novo mutation in CACNA1C can drive alterations in circuit formation and behavior. Autism is a disorder that affects neuronal development, leading to alterations in cognition and behavior. Imaging studies have revealed alterations in axonal connectivity as a key feature of autism. However, the underlying perturbations in cell biology that drive these alterations remain largely unknown. To address this issue, we have taken advantage of the Timothy syndrome mutation, a variant in a voltage-gated calcium channel that has the unusual property of causing autism with high penetrance. We identify a role for wild-type voltage-gated calcium channels in regulating axon targeting in C. elegans. Moreover, we find that two different versions of the Timothy syndrome mutation disrupt axon targeting. Our results suggest that the Timothy syndrome mutations disrupt axon targeting and behavior by interacting with genes that promote selective autophagy, the process through which cellular components are selected for degradation. These results reveal a mechanism through which variants in voltage-gated calcium channels can cause the disruptions in axonal connectivity that underlie autism.
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35
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Association between autophagy and rapid eye movement sleep loss-associated neurodegenerative and patho-physio-behavioral changes. Sleep Med 2019; 63:29-37. [DOI: 10.1016/j.sleep.2019.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/26/2019] [Accepted: 04/24/2019] [Indexed: 12/13/2022]
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36
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Chan HH, Koh RY, Lim CL, Leong CO. Receptor-Interacting Protein Kinase 1 (RIPK1) as a Potential Therapeutic Target: An Overview of Its Possible Role in the Pathogenesis of Alzheimer's Disease. Curr Alzheimer Res 2019; 16:907-918. [PMID: 31642777 DOI: 10.2174/1567205016666191023102422] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 08/02/2019] [Accepted: 09/06/2019] [Indexed: 01/03/2023]
Abstract
Alzheimer's Disease (AD) is an age-dependent neurodegenerative disorder, the most common type of dementia that is clinically characterized by the presence of beta-amyloid (Aβ) extracellularly and intraneuronal tau protein tangles that eventually leads to the onset of memory and cognition impairment, development of psychiatric symptoms and behavioral disorders that affect basic daily activities. Current treatment approved by the U.S Food and Drug Administration (FDA) for AD is mainly focused on the symptoms but not on the pathogenesis of the disease. Recently, receptor-interacting protein kinase 1 (RIPK1) has been identified as a key component in the pathogenesis of AD through necroptosis. Furthermore, genetic and pharmacological suppression of RIPK1 has been shown to revert the phenotype of AD and its mediating pathway is yet to be deciphered. This review is aimed to provide an overview of the pathogenesis and current treatment of AD with the involvement of autophagy as well as providing a novel insight into RIPK1 in reverting the progression of AD, probably through an autophagy machinery.
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Affiliation(s)
- Hong Hao Chan
- School of Postgraduate Studies and Research, International Medical University, Kuala Lumpur, Malaysia
| | - Rhun Yian Koh
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Chooi Ling Lim
- Division of Applied Biomedical Sciences and Biotechnology, School of Health Sciences, International Medical University, Kuala Lumpur, Malaysia
| | - Chee Onn Leong
- Department of Life Sciences, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
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Abstract
Autophagy is the major cellular pathway to degrade dysfunctional organelles and protein aggregates. Autophagy is particularly important in neurons, which are terminally differentiated cells that must last the lifetime of the organism. There are both constitutive and stress-induced pathways for autophagy in neurons, which catalyze the turnover of aged or damaged mitochondria, endoplasmic reticulum, other cellular organelles, and aggregated proteins. These pathways are required in neurodevelopment as well as in the maintenance of neuronal homeostasis. Here we review the core components of the pathway for autophagosome biogenesis, as well as the cell biology of bulk and selective autophagy in neurons. Finally, we discuss the role of autophagy in neuronal development, homeostasis, and aging and the links between deficits in autophagy and neurodegeneration.
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Affiliation(s)
- Andrea K H Stavoe
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA;
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA;
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38
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Boecker CA, Holzbaur EL. Vesicular degradation pathways in neurons: at the crossroads of autophagy and endo-lysosomal degradation. Curr Opin Neurobiol 2019; 57:94-101. [PMID: 30784982 PMCID: PMC6629518 DOI: 10.1016/j.conb.2019.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 01/04/2019] [Accepted: 01/10/2019] [Indexed: 12/12/2022]
Abstract
Autophagy and endo-lysosomal degradation are two parallel degradation pathways essential for maintaining neuronal health and function. Autophagosomes and endosomes sequester cellular cargo through different mechanisms, but these pathways converge upon fusion with lysosomes. Both pathways are spatially regulated, with distinct features evident in the soma, axons, and dendrites, possibly as an adaptation to the unique morphology of neurons and the specific demands of each compartment. Relatively little is known about how autophagy and endo-lysosomal degradation interact and how their activities may be coordinated. We review our current understanding of autophagy and endo-lysosomal degradation in neurons, highlighting common features and differences as well as the intersection of these two essential cellular pathways.
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Affiliation(s)
- C Alexander Boecker
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States.
| | - Erika Lf Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
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39
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Increases in miR-124-3p in Microglial Exosomes Confer Neuroprotective Effects by Targeting FIP200-Mediated Neuronal Autophagy Following Traumatic Brain Injury. Neurochem Res 2019; 44:1903-1923. [PMID: 31190315 DOI: 10.1007/s11064-019-02825-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/04/2019] [Accepted: 06/07/2019] [Indexed: 12/19/2022]
Abstract
In our recent study, we observed consistent increases in miR-124-3p levels in exosomes derived from cultured BV2 microglia which was treated with repetitive traumatic brain injury (rTBI) mouse model brain extracts. To clarify the mechanisms underlying increases in microglia-derived exosomal miR-124-3p and their role in regulating neuronal autophagy after TBI, we investigated the impact of exosomal miR-124-3p on neuronal autophagy in scratch-injured HT22 neurons and rTBI mice. We harvested injured brain extracts from rTBI mice at 3 to 21 days post injury (DPI) for the treatment of cultured BV2 microglia in vitro. We observed significant induction of autophagy following TBI in vitro, and that inhibition of activated neuronal autophagy could protect against trauma-induced injury. Our results indicated that co-culture of injured HT22 neurons with miR-124-3p overexpressing BV2 microglia exerted a protective effect by inhibiting neuronal autophagy in scratch-injured neurons. Further research revealed that these effects were achieved mainly via upregulation of exosomal miR-124-3p, and that Focal adhesion kinase family-interacting protein of 200 kDa (FIP200) plays a key role in trauma-induced autophagy. Injection of exosomes into the vena caudalis in in vivo experiments revealed that exosomal miR-124-3p was associated with decreases in the modified neurological severity score (mNSS) and improvements in Morris water maze (MWM) test results in rTBI mice. Altogether, our results indicate that increased miR-124-3p in microglial exosomes following TBI may inhibit neuronal autophagy and protect against nerve injury via their transfer into neurons. Thus, treatment with microglial exosomes enriched with miR-124-3p may represent a novel therapeutic strategy for the treatment of nerve injury after TBI.
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40
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Zhang H, Xiong Z, He Q, Fan F. ACSS2-related autophagy has a dual impact on memory. Chin Neurosurg J 2019; 5:14. [PMID: 32922914 PMCID: PMC7398205 DOI: 10.1186/s41016-019-0162-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 05/09/2019] [Indexed: 02/07/2023] Open
Abstract
Autophagy is an intracellular degenerative pathway which is responsible for neuronal survival. Under the condition of nutrient deprivation, autophagy can lead to dysfunction in memory consolidation. AMPK/mTOR pathway is currently the most studied autophagy mechanism, while recently researchers have proved ACSS2 can also affect autophagy. ACSS2 is phosphorylated at Ser659 by AMPK and then forms a translocation complex with Importin α5 to translocate into the nucleus. This process interacts with TFEB, resulting in upregulated expression of lysosomal and autophagosomal genes. These upregulations inhibit synaptic plasticity and hence memory functions. On the other hand, ACSS2 is also recognized as a regulator of histone acetylation. After recruiting CBP/p300 and activating CBP’s HAT activity in the nucleus, ACSS2 maintains the level of localized histone acetylation by recapturing acetate from histone deacetylation to reform acetyl-CoA, providing substrates for HAT. The increase of histone acetylation locally enhanced immediate early gene transcription, including Egr2, Fos, Nr2f2, Sgk1, and Arc, to benefit neuronal plasticity and memory in many ways.
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Affiliation(s)
- Hao Zhang
- Central South University, Xiangya Hospital, Changsha city, Hunan province China
| | - Zujian Xiong
- Central South University, Xiangya Hospital, Changsha city, Hunan province China
| | - Qin He
- Central South University, Xiangya Hospital, Changsha city, Hunan province China
| | - Fan Fan
- Central South University, Xiangya Hospital, Changsha city, Hunan province China
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41
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Bankston AN, Forston MD, Howard RM, Andres KR, Smith AE, Ohri SS, Bates ML, Bunge MB, Whittemore SR. Autophagy is essential for oligodendrocyte differentiation, survival, and proper myelination. Glia 2019; 67:1745-1759. [PMID: 31162728 DOI: 10.1002/glia.23646] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/01/2019] [Accepted: 05/21/2019] [Indexed: 12/12/2022]
Abstract
Deficient myelination, the spiral wrapping of highly specialized membrane around axons, causes severe neurological disorders. Maturation of oligodendrocyte progenitor cells (OPC) to myelinating oligodendrocytes (OL), the sole providers of central nervous system (CNS) myelin, is tightly regulated and involves extensive morphological changes. Here, we present evidence that autophagy, the targeted isolation of cytoplasm and organelles by the double-membrane autophagosome for lysosomal degradation, is essential for OPC/OL differentiation, survival, and proper myelin development. A marked increase in autophagic activity coincides with OL differentiation, with OL processes having the greatest increase in autophagic flux. Multiple lines of evidence indicate that autophagosomes form in developing myelin sheathes before trafficking from myelin to the OL soma. Mice with conditional OPC/OL-specific deletion of the essential autophagy gene Atg5 beginning on postnatal Day 5 develop a rapid tremor and die around postnatal Day 12. Further analysis revealed apoptotic death of OPCs, reduced differentiation, and reduced myelination. Surviving Atg5-/- OLs failed to produce proper myelin structure. In vitro, pharmacological inhibition of autophagy in OPC/dorsal root ganglion (DRG) co-cultures blocked myelination, producing OLs surrounded by many short processes. Conversely, autophagy stimulation enhanced myelination. These results implicate autophagy as a key regulator of OPC survival, maturation, and proper myelination. Autophagy may provide an attractive target to promote both OL survival and subsequent myelin repair after injury.
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Affiliation(s)
- Andrew N Bankston
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky
| | - Michael D Forston
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
| | - Russell M Howard
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky
| | - Kariena R Andres
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky
| | - Allison E Smith
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky
| | - Sujata Saraswat Ohri
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky
| | - Margaret L Bates
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida
| | - Mary B Bunge
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida.,Department of Cell Biology and Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida
| | - Scott R Whittemore
- Kentucky Spinal Cord Injury Research Center, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky.,Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky
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42
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Tettamanti G, Carata E, Montali A, Dini L, Fimia GM. Autophagy in development and regeneration: role in tissue remodelling and cell survival. EUROPEAN ZOOLOGICAL JOURNAL 2019. [DOI: 10.1080/24750263.2019.1601271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- G. Tettamanti
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - E. Carata
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
| | - A. Montali
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - L. Dini
- Department of Biology and Biotechnology Charles Darwin, Sapienza University of Rome, Rome, Italy
| | - G. M. Fimia
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Lecce, Italy
- Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases IRCCS “Lazzaro Spallanzani”, Rome, Italy
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Ho WY, Tai YK, Chang JC, Liang J, Tyan SH, Chen S, Guan JL, Zhou H, Shen HM, Koo E, Ling SC. The ALS-FTD-linked gene product, C9orf72, regulates neuronal morphogenesis via autophagy. Autophagy 2019; 15:827-842. [PMID: 30669939 PMCID: PMC6526867 DOI: 10.1080/15548627.2019.1569441] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 10/05/2018] [Accepted: 12/18/2018] [Indexed: 12/12/2022] Open
Abstract
Mutations in C9orf72 leading to hexanucleotide expansions are the most common genetic causes for amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). A phenotype resembling ALS and FTD is seen in transgenic mice overexpressing the hexanucleotide expansions, but is absent in C9orf72-deficient mice. Thus, the exact function of C9orf72 in neurons and how loss of C9orf72 may contribute to neuronal dysfunction remains to be clearly defined. Here, we showed that primary hippocampal neurons cultured from c9orf72 knockout mice have reduced dendritic arborization and spine density. Quantitative proteomic analysis identified C9orf72 as a component of the macroautophagy/autophagy initiation complex composed of ULK1-RB1CC1-ATG13-ATG101. The association was mediated through the direct interaction with ATG13 via the isoform-specific carboxyl-terminal DENN and dDENN domain of C9orf72. Furthermore, c9orf72 knockout neurons showed reduced LC3-II puncta accompanied by reduced ULK1 levels, suggesting that loss of C9orf72 impairs basal autophagy. Conversely, wild-type neurons treated with a ULK1 kinase inhibitor showed a dose-dependent reduction of dendritic arborization and spine density. Furthermore, expression of the long isoform of human C9orf72 that interacts with the ULK1 complex, but not the short isoform, rescues autophagy and the dendritic arborization phenotypes of c9orf72 knockout neurons. Taken together, our data suggests that C9orf72 has a cell-autonomous role in neuronal and dendritic morphogenesis through promotion of ULK1-mediated autophagy.
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Affiliation(s)
- Wan Yun Ho
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Yee Kit Tai
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Jer-Cherng Chang
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Jason Liang
- Ludwig Institute for Cancer Research, University of California at San Diego, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Sheue-Houy Tyan
- Department of Medicine, National University of Singapore, Singapore, Singapore
| | - Song Chen
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jun-Lin Guan
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Huilin Zhou
- Ludwig Institute for Cancer Research, University of California at San Diego, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, CA, USA
| | - Han-Ming Shen
- Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Edward Koo
- Department of Medicine, National University of Singapore, Singapore, Singapore
- Department of Neurosciences, University of California at San Diego, La Jolla, CA, USA
| | - Shuo-Chien Ling
- Department of Physiology, National University of Singapore, Singapore, Singapore
- Neurobiology/Ageing Programme, National University of Singapore, Singapore, Singapore
- Neuroscience and Behavioural Disorders Programme, Duke-NUS Medical School, Singapore, Singapore
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Tang BL. Why is NMNAT Protective against Neuronal Cell Death and Axon Degeneration, but Inhibitory of Axon Regeneration? Cells 2019; 8:cells8030267. [PMID: 30901919 PMCID: PMC6468476 DOI: 10.3390/cells8030267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 03/15/2019] [Accepted: 03/18/2019] [Indexed: 02/06/2023] Open
Abstract
Nicotinamide mononucleotide adenylyltransferase (NMNAT), a key enzyme for NAD+ synthesis, is well known for its activity in neuronal survival and attenuation of Wallerian degeneration. Recent investigations in invertebrate models have, however, revealed that NMNAT activity negatively impacts upon axon regeneration. Overexpression of Nmnat in laser-severed Drosophila sensory neurons reduced axon regeneration, while axon regeneration was enhanced in injured mechanosensory axons in C. elegansnmat-2 null mutants. These diametrically opposite effects of NMNAT orthologues on neuroprotection and axon regeneration appear counterintuitive as there are many examples of neuroprotective factors that also promote neurite outgrowth, and enhanced neuronal survival would logically facilitate regeneration. We suggest here that while NMNAT activity and NAD+ production activate neuroprotective mechanisms such as SIRT1-mediated deacetylation, the same mechanisms may also activate a key axonal regeneration inhibitor, namely phosphatase and tensin homolog (PTEN). SIRT1 is known to deacetylate and activate PTEN which could, in turn, suppress PI3 kinase–mTORC1-mediated induction of localized axonal protein translation, an important process that determines successful regeneration. Strategic tuning of Nmnat activity and NAD+ production in axotomized neurons may thus be necessary to promote initial survival without inhibiting subsequent regeneration.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117597, Singapore.
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Li D, Huang S, Zhu J, Hu T, Han Z, Zhang S, Zhao J, Chen F, Lei P. Exosomes from MiR-21-5p-Increased Neurons Play a Role in Neuroprotection by Suppressing Rab11a-Mediated Neuronal Autophagy In Vitro After Traumatic Brain Injury. Med Sci Monit 2019; 25:1871-1885. [PMID: 30860987 PMCID: PMC6423733 DOI: 10.12659/msm.915727] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Traumatic brain injury (TBI) produces a series of pathological processes. Recent studies have indicated that autophagy pathway is persistently activated after TBI, which may lead to deterioration of nerve injury. Our preliminary work found miR-21-5p was upregulated in both in vivo and in vitro TBI models. MicroRNAs (miRNAs) could be loaded into exosomes to perform cell-to-cell interactions. This research aimed to evaluate the therapeutic effect of neuron-derived exosomes enriched with miR-21-5p on the TBI in vitro and to further explore the possible mechanisms. Material/Methods Brain extracts harvested from an rTBI mouse model were added to cultured HT-22 neurons to imitate the microenvironment of injured brain on in vitro cultured cells. Ultracentrifugation was performed to isolate exosomes. Transmission electron microscopy and Nano sight technology were used to examine exosomes. An in vitro model of TBI was established to study the effect of exosomal miR-21-5p on nerve injury and on neuronal autophagy regulation. Results The expression of miR-21-5p was increased in exosomes derived from HT-22 neurons after treatment with rTBI mouse brain extracts. Autophagy was activated in HT-22 neurons after scratch injury. Exosomal miR-21-5p produced a protective effect by suppressing autophagy in a TBI model in vitro. MiR-21-5p could directly target the Rab11a 3′UTR region to reduce its translation and further suppressed Rab11a-mediated neuronal autophagy. Conclusions The levels of miR-21-5p in neuronal exosomes increased from the acute to the chronic phase of TBI. Neuronal exosomes enriched with miR-21-5p can inhibit the activity of neuronal autophagy by targeting Rab11a, thus attenuating trauma-induced, autophagy-mediated nerve injury in vitro.
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Affiliation(s)
- Dai Li
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Shan Huang
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Jialin Zhu
- Department of Ultrasound Diagnosis and Treatment, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China (mainland)
| | - Tianpeng Hu
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Zhaoli Han
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Shishuang Zhang
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Jing Zhao
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Fanglian Chen
- Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin, China (mainland)
| | - Ping Lei
- Laboratory of Neuro-Trauma and Neurodegenerative Disorders, Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
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Palmisano NJ, Meléndez A. Autophagy in C. elegans development. Dev Biol 2019; 447:103-125. [PMID: 29709599 PMCID: PMC6204124 DOI: 10.1016/j.ydbio.2018.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 03/19/2018] [Accepted: 04/12/2018] [Indexed: 12/11/2022]
Abstract
Autophagy involves the sequestration of cytoplasmic contents in a double-membrane structure referred to as the autophagosome and the degradation of its contents upon delivery to lysosomes. Autophagy activity has a role in multiple biological processes during the development of the nematode Caenorhabditis elegans. Basal levels of autophagy are required to remove aggregate prone proteins, paternal mitochondria, and spermatid-specific membranous organelles. During larval development, autophagy is required for the remodeling that occurs during dauer development, and autophagy can selectively degrade components of the miRNA-induced silencing complex, and modulate miRNA-mediated silencing. Basal levels of autophagy are important in synapse formation and in the germ line, to promote the proliferation of proliferating stem cells. Autophagy activity is also required for the efficient removal of apoptotic cell corpses by promoting phagosome maturation. Finally, autophagy is also involved in lipid homeostasis and in the aging process. In this review, we first describe the molecular complexes involved in the process of autophagy, its regulation, and mechanisms for cargo recognition. In the second section, we discuss the developmental contexts where autophagy has been shown to be important. Studies in C. elegans provide valuable insights into the physiological relevance of this process during metazoan development.
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Affiliation(s)
- Nicholas J Palmisano
- Biology Department, Queens College, CUNY, Flushing, NY, USA; Biology Ph.D. Program, The Graduate Center of the City University of New York, NK, USA
| | - Alicia Meléndez
- Biology Department, Queens College, CUNY, Flushing, NY, USA; Biology Ph.D. Program, The Graduate Center of the City University of New York, NK, USA; Biochemistry Ph.D. Program, The Graduate Center of the City University of New York, NY, USA.
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Petrova V, Eva R. The Virtuous Cycle of Axon Growth: Axonal Transport of Growth-Promoting Machinery as an Intrinsic Determinant of Axon Regeneration. Dev Neurobiol 2018; 78:898-925. [PMID: 29989351 DOI: 10.1002/dneu.22608] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 02/02/2023]
Abstract
Injury to the brain and spinal cord has devastating consequences because adult central nervous system (CNS) axons fail to regenerate. Injury to the peripheral nervous system (PNS) has a better prognosis, because adult PNS neurons support robust axon regeneration over long distances. CNS axons have some regenerative capacity during development, but this is lost with maturity. Two reasons for the failure of CNS regeneration are extrinsic inhibitory molecules, and a weak intrinsic capacity for growth. Extrinsic inhibitory molecules have been well characterized, but less is known about the neuron-intrinsic mechanisms which prevent axon re-growth. Key signaling pathways and genetic/epigenetic factors have been identified which can enhance regenerative capacity, but the precise cellular mechanisms mediating their actions have not been characterized. Recent studies suggest that an important prerequisite for regeneration is an efficient supply of growth-promoting machinery to the axon; however, this appears to be lacking from non-regenerative axons in the adult CNS. In the first part of this review, we summarize the evidence linking axon transport to axon regeneration. We discuss the developmental decline in axon regeneration capacity in the CNS, and comment on how this is paralleled by a similar decline in the selective axonal transport of regeneration-associated receptors such as integrins and growth factor receptors. In the second part, we discuss the mechanisms regulating selective polarized transport within neurons, how these relate to the intrinsic control of axon regeneration, and whether they can be targeted to enhance regenerative capacity. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 00: 000-000, 2018.
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Affiliation(s)
- Veselina Petrova
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
| | - Richard Eva
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
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48
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ROCK inhibition in models of neurodegeneration and its potential for clinical translation. Pharmacol Ther 2018; 189:1-21. [DOI: 10.1016/j.pharmthera.2018.03.008] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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49
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Wang Y, Song M, Song F. Neuronal autophagy and axon degeneration. Cell Mol Life Sci 2018; 75:2389-2406. [PMID: 29675785 PMCID: PMC11105516 DOI: 10.1007/s00018-018-2812-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 03/13/2018] [Accepted: 04/03/2018] [Indexed: 02/08/2023]
Abstract
Axon degeneration is a pathophysiological process of axonal dying and breakdown, which is characterized by several morphological features including the accumulation of axoplasmic organelles, disassembly of microtubules, and fragmentation of the axonal cytoskeleton. Autophagy, a highly conserved lysosomal-degradation machinery responsible for the control of cellular protein quality, is widely believed to be essential for the maintenance of axonal homeostasis in neurons. In recent years, more and more evidence suggests that dysfunctional autophagy is associated with axonal degeneration in many neurodegenerative diseases. Here, we review the core machinery of autophagy in neuronal cells, and provide several major steps that interfere with autophagy flux in neurodegenerative conditions. Furthermore, this review highlights the potential role of neuronal autophagy in axon degeneration, and presents some possible molecular mechanisms by which dysfunctional autophagy leads to axon degeneration in pathological conditions.
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Affiliation(s)
- Yu Wang
- Department of Toxicology, School of Public Health, Shandong University, 44 Wenhuaxi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Mingxue Song
- School of Public Health, Fujian Medical University, 1 Xueyuan Road, Fuzhou, 350108, Fujian, People's Republic of China
| | - Fuyong Song
- Department of Toxicology, School of Public Health, Shandong University, 44 Wenhuaxi Road, Jinan, 250012, Shandong, People's Republic of China.
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50
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Abstract
Neurons are particularly dependent on robust quality control pathways to maintain cellular homeostasis and functionality throughout their extended lifetime. Failure to regulate protein and organelle integrity is linked to devastating neurodegenerative diseases. Autophagy is a lysosomal degradation pathway that maintains homeostasis by recycling damaged or aged cellular components. Autophagy has important functions in development of the nervous system, as well as in neuronal function and survival. In fact, defects in autophagy underlie neurodegeneration in mice and humans. Here, we review the compartment-specific dynamics and functions for autophagy in neurons. Emerging evidence suggests novel pathways for the intercellular coordination of quality control pathways between neurons and glia to maintain homeostasis in the brain.
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Affiliation(s)
- Aditi Kulkarni
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jessica Chen
- 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.
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