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Scholz K, Pattanayak R, Roschonporn E, Pair FS, Nobles A, Yacoubian TA. Rab27b promotes lysosomal function and alpha-synuclein clearance in neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599785. [PMID: 38979346 PMCID: PMC11230153 DOI: 10.1101/2024.06.20.599785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Alpha-synuclein (αsyn) is the key pathogenic protein implicated in synucleinopathies including Parkinson's Disease (PD) and Dementia with Lewy Bodies (DLB). In these diseases, αsyn is thought to spread between cells where it accumulates and induces pathology; however, mechanisms that drive its propagation or aggregation are poorly understood. We have previously reported that the small GTPase Rab27b is elevated in human PD and DLB and that it can mediate the autophagic clearance and toxicity of αsyn in a paracrine αsyn cell culture neuronal model. Here, we expanded our previous work and further characterized a role for Rab27b in neuronal lysosomal processing and αsyn clearance. We found that Rab27b KD in this αsyn inducible neuronal model resulted in lysosomal dysfunction and increased αsyn levels in lysosomes. Similar lysosomal proteolytic defects and enzymatic dysfunction were observed in both primary neuronal cultures and brain lysates from Rab27b knockout (KO) mice. αSyn aggregation was exacerbated in Rab27b KO neurons upon treatment with αsyn preformed fibrils. We found no changes in lysosomal counts or lysosomal pH in either model, but we did identify defects in acidic vesicle trafficking in Rab27b KO primary neurons which may drive lysosomal dysfunction and promote αsyn aggregation. Rab27b OE enhanced lysosomal activity and reduced insoluble αsyn accumulation. Finally we found elevated Rab27b levels in human postmortem incidental Lewy Body Disease (iLBD) subjects relative to healthy controls. These data suggest a role for Rab27b in neuronal lysosomal activity and identify it as a potential therapeutic target in synucleinopathies.
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Jenkins JE, Fazli M, Evans CS. Mitochondrial motility modulators coordinate quality control dynamics to promote neuronal health. Curr Opin Cell Biol 2024; 89:102383. [PMID: 38908094 DOI: 10.1016/j.ceb.2024.102383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 05/24/2024] [Accepted: 05/28/2024] [Indexed: 06/24/2024]
Abstract
Dysfunction in mitochondrial maintenance and trafficking is commonly correlated with the development of neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. Thus, biomedical research has been dedicated to understanding how architecturally complex neurons maintain and transport their mitochondria. However, the systems that coordinate mitochondrial QC (quality control) dynamics and trafficking in response to neuronal activity and stress are less understood. Additionally, the degree of integration between the processes of mitochondrial trafficking and QC is unclear. Recent work indicates that mitochondrial motility modulators (i.e., anchors and tethers) help coordinate mitochondrial health by mediating distinct, stress-level-appropriate QC pathways following mitochondrial damage. This review summarizes current evidence supporting the role of two mitochondrial motility modulators, Syntaphilin and Mitofusin 2, in coordinating mitochondrial QC to promote neuronal health. Exploring motility modulators' intricate regulatory molecular landscape may reveal new therapeutic targets for delaying disease progression and enhancing neuronal survival post-insult.
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Affiliation(s)
- Jennifer E Jenkins
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mohammad Fazli
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Chantell S Evans
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA; Howard Hughes Medical Institute, Duke University School of Medicine, Durham, NC 27710, USA.
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3
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Paumier JM, Gowrishankar S. Disruptions in axonal lysosome transport and its contribution to neurological disease. Curr Opin Cell Biol 2024; 89:102382. [PMID: 38905918 DOI: 10.1016/j.ceb.2024.102382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 06/23/2024]
Abstract
Lysosomes are central to the maintenance of protein and organelle homeostasis in cells. Optimal lysosome function is particularly critical for neurons which are long-lived, non-dividing and highly polarized with specialized compartments such as axons and dendrites with distinct architecture, cargo, and turnover requirements. In recent years, there has been a growing appreciation for the role played by axonal lysosome transport in regulating neuronal development, its maintenance and functioning. Perturbations to optimal axonal lysosome abundance leading to either strong accumulations or dearth of lysosomes are both linked to altered neuronal health and functioning. In this review we highlight how two critical regulators of axonal lysosome transport and abundance, the small GTPase Arl8 and the adaptor protein JIP3, aid in maintaining axonal lysosome homeostasis and how alterations to their levels and activity could contribute to neurodevelopmental and neurodegenerative diseases.
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Affiliation(s)
- Jean-Michel Paumier
- Department of Anatomy and Cell Biology, University of Illinois Chicago, 808 S Wood St, Chicago, IL 60612, USA
| | - Swetha Gowrishankar
- Department of Anatomy and Cell Biology, University of Illinois Chicago, 808 S Wood St, Chicago, IL 60612, USA.
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4
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Xiong GJ, Sheng ZH. Presynaptic perspective: Axonal transport defects in neurodevelopmental disorders. J Cell Biol 2024; 223:e202401145. [PMID: 38568173 PMCID: PMC10988239 DOI: 10.1083/jcb.202401145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/05/2024] Open
Abstract
Disruption of synapse assembly and maturation leads to a broad spectrum of neurodevelopmental disorders. Presynaptic proteins are largely synthesized in the soma, where they are packaged into precursor vesicles and transported into distal axons to ensure precise assembly and maintenance of presynapses. Due to their morphological features, neurons face challenges in the delivery of presynaptic cargos to nascent boutons. Thus, targeted axonal transport is vital to build functional synapses. A growing number of mutations in genes encoding the transport machinery have been linked to neurodevelopmental disorders. Emerging lines of evidence have started to uncover presynaptic mechanisms underlying axonal transport defects, thus broadening the view of neurodevelopmental disorders beyond postsynaptic mechanisms. In this review, we discuss presynaptic perspectives of neurodevelopmental disorders by focusing on impaired axonal transport and disturbed assembly and maintenance of presynapses. We also discuss potential strategies for restoring axonal transport as an early therapeutic intervention.
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Affiliation(s)
- Gui-Jing Xiong
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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5
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De Pace R, Ghosh S, Ryan VH, Sohn M, Jarnik M, Rezvan Sangsari P, Morgan NY, Dale RK, Ward ME, Bonifacino JS. Messenger RNA transport on lysosomal vesicles maintains axonal mitochondrial homeostasis and prevents axonal degeneration. Nat Neurosci 2024; 27:1087-1102. [PMID: 38600167 PMCID: PMC11156585 DOI: 10.1038/s41593-024-01619-1] [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: 05/16/2023] [Accepted: 03/07/2024] [Indexed: 04/12/2024]
Abstract
In neurons, RNA granules are transported along the axon for local translation away from the soma. Recent studies indicate that some of this transport involves hitchhiking of RNA granules on lysosome-related vesicles. In the present study, we leveraged the ability to prevent transport of these vesicles into the axon by knockout of the lysosome-kinesin adaptor BLOC-one-related complex (BORC) to identify a subset of axonal mRNAs that depend on lysosome-related vesicles for transport. We found that BORC knockout causes depletion of a large group of axonal mRNAs mainly encoding ribosomal and mitochondrial/oxidative phosphorylation proteins. This depletion results in mitochondrial defects and eventually leads to axonal degeneration in human induced pluripotent stem cell (iPSC)-derived and mouse neurons. Pathway analyses of the depleted mRNAs revealed a mechanistic connection of BORC deficiency with common neurodegenerative disorders. These results demonstrate that mRNA transport on lysosome-related vesicles is critical for the maintenance of axonal homeostasis and that its failure causes axonal degeneration.
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Affiliation(s)
- Raffaella De Pace
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Saikat Ghosh
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Veronica H Ryan
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Mira Sohn
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Michal Jarnik
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Paniz Rezvan Sangsari
- Biomedical Engineering and Physical Science Shared Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Nicole Y Morgan
- Biomedical Engineering and Physical Science Shared Resource, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Ryan K Dale
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Michael E Ward
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Juan S Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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6
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Manzoli R, Badenetti L, Bruzzone M, Macario MC, Rubin M, Dal Maschio M, Roveri A, Moro E. Mucopolysaccharidosis type II zebrafish model exhibits early impaired proteasomal-mediated degradation of the axon guidance receptor Dcc. Cell Death Dis 2024; 15:269. [PMID: 38627369 PMCID: PMC11021486 DOI: 10.1038/s41419-024-06661-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 04/02/2024] [Accepted: 04/08/2024] [Indexed: 04/19/2024]
Abstract
Most of the patients affected by neuronopathic forms of Mucopolysaccharidosis type II (MPS II), a rare lysosomal storage disorder caused by defects in iduronate-2-sulfatase (IDS) activity, exhibit early neurological defects associated with white matter lesions and progressive behavioural abnormalities. While neuronal degeneration has been largely described in experimental models and human patients, more subtle neuronal pathogenic defects remain still underexplored. In this work, we discovered that the axon guidance receptor Deleted in Colorectal Cancer (Dcc) is significantly dysregulated in the brain of ids mutant zebrafish since embryonic stages. In addition, thanks to the establishment of neuronal-enriched primary cell cultures, we identified defective proteasomal degradation as one of the main pathways underlying Dcc upregulation in ids mutant conditions. Furthermore, ids mutant fish-derived primary neurons displayed higher levels of polyubiquitinated proteins and P62, suggesting a wider defect in protein degradation. Finally, we show that ids mutant larvae display an atypical response to anxiety-inducing stimuli, hence mimicking one of the characteristic features of MPS II patients. Our study provides an additional relevant frame to MPS II pathogenesis, supporting the concept that multiple developmental defects concur with early childhood behavioural abnormalities.
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Affiliation(s)
- Rosa Manzoli
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy.
- Department of Biology, University of Padova, 35121, Padova, Italy.
| | - Lorenzo Badenetti
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
- Department of Women's and Children's Health, University of Padova, 35128, Padova, Italy
- Istituto di Ricerca Pediatrica "Città Della Speranza", 35127, Padova, Italy
| | - Matteo Bruzzone
- Department of Biomedical Sciences, University of Padova, 35121, Padova, Italy
- Padua Neuroscience Center - PNC, University of Padova, 35129, Padova, Italy
| | - Maria Carla Macario
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
- Department of Biology, University of Padova, 35121, Padova, Italy
| | - Michela Rubin
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Marco Dal Maschio
- Department of Biomedical Sciences, University of Padova, 35121, Padova, Italy
- Padua Neuroscience Center - PNC, University of Padova, 35129, Padova, Italy
| | - Antonella Roveri
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Enrico Moro
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy.
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7
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Konietzny A, Han Y, Popp Y, van Bommel B, Sharma A, Delagrange P, Arbez N, Moutin MJ, Peris L, Mikhaylova M. Efficient axonal transport of endolysosomes relies on the balanced ratio of microtubule tyrosination and detyrosination. J Cell Sci 2024; 137:jcs261737. [PMID: 38525600 PMCID: PMC11112122 DOI: 10.1242/jcs.261737] [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: 10/18/2023] [Accepted: 03/14/2024] [Indexed: 03/26/2024] Open
Abstract
In neurons, the microtubule (MT) cytoskeleton forms the basis for long-distance protein transport from the cell body into and out of dendrites and axons. To maintain neuronal polarity, the axon initial segment (AIS) serves as a physical barrier, separating the axon from the somatodendritic compartment and acting as a filter for axonal cargo. Selective trafficking is further instructed by axonal enrichment of MT post-translational modifications, which affect MT dynamics and the activity of motor proteins. Here, we compared two knockout mouse lines lacking the respective enzymes for MT tyrosination and detyrosination, and found that both knockouts led to a shortening of the AIS. Neurons from both lines also showed an increased immobile fraction of endolysosomes present in the axon, whereas mobile organelles displayed shortened run distances in the retrograde direction. Overall, our results highlight the importance of maintaining the balance of tyrosinated and detyrosinated MTs for proper AIS length and axonal transport processes.
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Affiliation(s)
- Anja Konietzny
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan
| | - Yuhao Han
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Centre for Structural Systems Biology, Hamburg 22607, Germany
- Structural Cell Biology of Viruses, Leibniz Institute of Virology (LIV), Hamburg 20251, Germany
| | - Yannes Popp
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Charité – Universitätsmedizin Berlin, Einstein Center for Neurosciences Berlin, 10117 Berlin, Germany
| | - Bas van Bommel
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin 14195, Germany
| | - Aditi Sharma
- University Grenoble Alpes, Inserm U1216, CNRS, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | | | - Nicolas Arbez
- Institut de Recherche Servier, Croissy 78290, France
| | - Marie-Jo Moutin
- University Grenoble Alpes, Inserm U1216, CNRS, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Leticia Peris
- University Grenoble Alpes, Inserm U1216, CNRS, Grenoble Institut Neurosciences, 38000 Grenoble, France
| | - Marina Mikhaylova
- RG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin 10115, Germany
- Guest Group ‘Neuronal Protein Transport’, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
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8
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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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Cason SE, Holzbaur EL. Axonal transport of autophagosomes is regulated by dynein activators JIP3/JIP4 and ARF/RAB GTPases. J Cell Biol 2023; 222:e202301084. [PMID: 37909920 PMCID: PMC10620608 DOI: 10.1083/jcb.202301084] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 08/28/2023] [Accepted: 10/05/2023] [Indexed: 11/03/2023] Open
Abstract
Neuronal autophagosomes form and engulf cargos at presynaptic sites in the axon and are then transported to the soma to recycle their cargo. Autophagic vacuoles (AVs) mature en route via fusion with lysosomes to become degradatively competent organelles; transport is driven by the microtubule motor protein cytoplasmic dynein, with motor activity regulated by a sequential series of adaptors. Using lysate-based single-molecule motility assays and live-cell imaging in primary neurons, we show that JNK-interacting proteins 3 (JIP3) and 4 (JIP4) are activating adaptors for dynein that are regulated on autophagosomes and lysosomes by the small GTPases ARF6 and RAB10. GTP-bound ARF6 promotes formation of the JIP3/4-dynein-dynactin complex. Either knockdown or overexpression of RAB10 stalls transport, suggesting that this GTPase is also required to coordinate the opposing activities of bound dynein and kinesin motors. These findings highlight the complex coordination of motor regulation during organelle transport in neurons.
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Affiliation(s)
- Sydney E. Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA
- Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
- Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Erika L.F. Holzbaur
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA
- Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
- Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA, USA
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10
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Tsong H, Holzbaur ELF, Stavoe AKH. Aging Differentially Affects Axonal Autophagosome Formation and Maturation. Autophagy 2023; 19:3079-3095. [PMID: 37464898 PMCID: PMC10621248 DOI: 10.1080/15548627.2023.2236485] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 06/21/2023] [Accepted: 07/03/2023] [Indexed: 07/20/2023] Open
Abstract
Misregulation of neuronal macroautophagy/autophagy has been implicated in age-related neurodegenerative diseases. We compared autophagosome formation and maturation in primary murine neurons during development and through aging to elucidate how aging affects neuronal autophagy. We observed an age-related decrease in the rate of autophagosome formation leading to a significant decrease in the density of autophagosomes along the axon. Next, we identified a surprising increase in the maturation of autophagic vesicles in neurons from aged mice. While we did not detect notable changes in endolysosomal content in the distal axon during early aging, we did observe a significant loss of acidified vesicles in the distal axon during late aging. Interestingly, we found that autophagic vesicles were transported more efficiently in neurons from adult mice than in neurons from young mice. This efficient transport of autophagic vesicles in both the distal and proximal axon is maintained in neurons during early aging, but is lost during late aging. Our data indicate that early aging does not negatively impact autophagic vesicle transport nor the later stages of autophagy. However, alterations in autophagic vesicle transport efficiency during late aging reveal that aging differentially impacts distinct aspects of neuronal autophagy.Abbreviations: ACAP3: ArfGAP with coiled-coil, ankyrin repeat and PH domains 3; ARF6: ADP-ribosylation factor 6; ATG: autophagy related; AVs: autophagic vesicles; DCTN1/p150Glued: dynactin 1; DRG: dorsal root ganglia; GAP: GTPase activating protein; GEF: guanine nucleotide exchange factor; LAMP2: lysosomal-associated protein 2; LysoT: LysoTracker; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAPK8IP1/JIP1: mitogen-activated protein kinase 8 interacting protein 1; MAPK8IP3/JIP3: mitogen-activated protein kinase 8 interacting protein 3; mCh: mCherry; PE: phosphatidylethanolamine.
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Affiliation(s)
- Heather Tsong
- Department of Neurobiology & Anatomy, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Erika LF Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Andrea KH Stavoe
- Department of Neurobiology & Anatomy, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
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11
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El-Agamy SE, Guillaud L, Kono K, Wu Y, Terenzio M. FMRP Long-Range Transport and Degradation Are Mediated by Dynlrb1 in Sensory Neurons. Mol Cell Proteomics 2023; 22:100653. [PMID: 37739344 PMCID: PMC10625159 DOI: 10.1016/j.mcpro.2023.100653] [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: 02/10/2023] [Revised: 09/10/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023] Open
Abstract
The fragile X messenger ribonucleoprotein 1 (FMRP) is a multifunctional RNA-binding protein implicated in human neurodevelopmental and neurodegenerative disorders. FMRP mediates the localization and activity-dependent translation of its associated mRNAs through the formation of phase-separated condensates that are trafficked by microtubule-based motors in axons. Axonal transport and localized mRNA translation are critical processes for long-term neuronal survival and are closely linked to the pathogenesis of neurological diseases. FMRP dynein-mediated axonal trafficking is still largely unexplored but likely to constitute a key process underlying FMRP spatiotemporal translational regulation. Here, we show that dynein light chain roadblock 1 (Dynlrb1), a subunit of the dynein complex, is a critical regulator of FMRP function. In sensory axons, FMRP associates with endolysosomal organelles, likely through annexin A11, and is retrogradely trafficked by the dynein complex in a Dynlrb1-dependent manner. Moreover, Dynlrb1 silencing induced FMRP granule accumulation and repressed the translation of microtubule-associated protein 1b, one of its primary mRNA targets. Our findings suggest that Dynlrb1 regulates FMRP function through the control of its transport and targeted degradation.
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Affiliation(s)
- Sara Emad El-Agamy
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Laurent Guillaud
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Keiko Kono
- Membranology Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan
| | - Yibo Wu
- YCI Laboratory for Next-Generation Proteomics, RIKEN Center of Integrative Medical Sciences, Yokohama, Kanagawa, Japan; Chemical Biology Mass Spectrometry Platform (ChemBioMS), Faculty of Science, University of Geneva, Geneva, Switzerland
| | - Marco Terenzio
- Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan.
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12
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Beckers J, Tharkeshwar AK, Fumagalli L, Contardo M, Van Schoor E, Fazal R, Thal DR, Chandran S, Mancuso R, Van Den Bosch L, Van Damme P. A toxic gain-of-function mechanism in C9orf72 ALS impairs the autophagy-lysosome pathway in neurons. Acta Neuropathol Commun 2023; 11:151. [PMID: 37723585 PMCID: PMC10506245 DOI: 10.1186/s40478-023-01648-0] [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: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/20/2023] Open
Abstract
BACKGROUND Motor neurons (MNs), which are primarily affected in amyotrophic lateral sclerosis (ALS), are a specialized type of neurons that are long and non-dividing. Given their unique structure, these cells heavily rely on transport of organelles along their axons and the process of autophagy to maintain their cellular homeostasis. It has been shown that disruption of the autophagy pathway is sufficient to cause progressive neurodegeneration and defects in autophagy have been associated with various subtypes of ALS, including those caused by hexanucleotide repeat expansions in the C9orf72 gene. A more comprehensive understanding of the dysfunctional cellular mechanisms will help rationalize the design of potent and selective therapies for C9orf72-ALS. METHODS In this study, we used induced pluripotent stem cell (iPSC)-derived MNs from C9orf72-ALS patients and isogenic control lines to identify the underlying mechanisms causing dysregulations of the autophagy-lysosome pathway. Additionally, to ascertain the potential impact of C9orf72 loss-of-function on autophagic defects, we characterized the observed phenotypes in a C9orf72 knockout iPSC line (C9-KO). RESULTS Despite the evident presence of dysfunctions in several aspects of the autophagy-lysosome pathway, such as disrupted lysosomal homeostasis, abnormal lysosome morphology, inhibition of autophagic flux, and accumulation of p62 in C9orf72-ALS MNs, we were surprised to find that C9orf72 loss-of-function had minimal influence on these phenotypes. Instead, we primarily observed impairment in endosome maturation as a result of C9orf72 loss-of-function. Additionally, our study shed light on the pathological mechanisms underlying C9orf72-ALS, as we detected an increased TBK1 phosphorylation at S172 in MNs derived from C9orf72 ALS patients. CONCLUSIONS Our data provides further insight into the involvement of defects in the autophagy-lysosome pathway in C9orf72-ALS and strongly indicate that those defects are mainly due to the toxic gain-of-function mechanisms underlying C9orf72-ALS.
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Affiliation(s)
- Jimmy Beckers
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium.
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium.
| | - Arun Kumar Tharkeshwar
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
- Department of Human Genetics, KU Leuven, Louvain, Belgium
| | - Laura Fumagalli
- Center for Molecular Neurology, Microglia and Inflammation in Neurological Disorders (MIND) Lab, VIB, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Matilde Contardo
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Evelien Van Schoor
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
- Laboratory of Neuropathology, Department of Imaging and Pathology, Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
| | - Raheem Fazal
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Dietmar Rudolf Thal
- Laboratory of Neuropathology, Department of Imaging and Pathology, Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
- Department of Pathology, University Hospitals Leuven, Louvain, Belgium
| | - Siddharthan Chandran
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, EH16 4SB, UK
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Renzo Mancuso
- Center for Molecular Neurology, Microglia and Inflammation in Neurological Disorders (MIND) Lab, VIB, Antwerp, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium
| | - Philip Van Damme
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Louvain - University of Leuven, Leuven, Belgium.
- Center for Brain and Disease Research, Laboratory of Neurobiology, VIB, Leuven, Belgium.
- Department of Neurology, University Hospitals Leuven, Louvain, Belgium.
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13
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Mulligan RJ, Winckler B. Regulation of Endosomal Trafficking by Rab7 and Its Effectors in Neurons: Clues from Charcot-Marie-Tooth 2B Disease. Biomolecules 2023; 13:1399. [PMID: 37759799 PMCID: PMC10527268 DOI: 10.3390/biom13091399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 09/09/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Intracellular endosomal trafficking controls the balance between protein degradation and synthesis, i.e., proteostasis, but also many of the cellular signaling pathways that emanate from activated growth factor receptors after endocytosis. Endosomal trafficking, sorting, and motility are coordinated by the activity of small GTPases, including Rab proteins, whose function as molecular switches direct activity at endosomal membranes through effector proteins. Rab7 is particularly important in the coordination of the degradative functions of the pathway. Rab7 effectors control endosomal maturation and the properties of late endosomal and lysosomal compartments, such as coordination of recycling, motility, and fusion with downstream compartments. The spatiotemporal regulation of endosomal receptor trafficking is particularly challenging in neurons because of their enormous size, their distinct intracellular domains with unique requirements (dendrites vs. axons), and their long lifespans as postmitotic, differentiated cells. In Charcot-Marie-Tooth 2B disease (CMT2B), familial missense mutations in Rab7 cause alterations in GTPase cycling and trafficking, leading to an ulcero-mutilating peripheral neuropathy. The prevailing hypothesis to account for CMT2B pathologies is that CMT2B-associated Rab7 alleles alter endocytic trafficking of the neurotrophin NGF and its receptor TrkA and, thereby, disrupt normal trophic signaling in the peripheral nervous system, but other Rab7-dependent pathways are also impacted. Here, using TrkA as a prototypical endocytic cargo, we review physiologic Rab7 effector interactions and control in neurons. Since neurons are among the largest cells in the body, we place particular emphasis on the temporal and spatial regulation of endosomal sorting and trafficking in neuronal processes. We further discuss the current findings in CMT2B mutant Rab7 models, the impact of mutations on effector interactions or balance, and how this dysregulation may confer disease.
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Affiliation(s)
- Ryan J. Mulligan
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22903, USA
- Medical Scientist Training Program, University of Virginia, Charlottesville, VA 22903, USA
| | - Bettina Winckler
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22903, USA
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14
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Buck TM, Quinn PMJ, Pellissier LP, Mulder AA, Jongejan A, Lu X, Boon N, Koot D, Almushattat H, Arendzen CH, Vos RM, Bradley EJ, Freund C, Mikkers HMM, Boon CJF, Moerland PD, Baas F, Koster AJ, Neefjes J, Berlin I, Jost CR, Wijnholds J. CRB1 is required for recycling by RAB11A+ vesicles in human retinal organoids. Stem Cell Reports 2023; 18:1793-1810. [PMID: 37541258 PMCID: PMC10545476 DOI: 10.1016/j.stemcr.2023.07.001] [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: 12/22/2021] [Revised: 07/03/2023] [Accepted: 07/04/2023] [Indexed: 08/06/2023] Open
Abstract
CRB1 gene mutations can cause early- or late-onset retinitis pigmentosa, Leber congenital amaurosis, or maculopathy. Recapitulating human CRB1 phenotypes in animal models has proven challenging, necessitating the development of alternatives. We generated human induced pluripotent stem cell (iPSC)-derived retinal organoids of patients with retinitis pigmentosa caused by biallelic CRB1 mutations and evaluated them against autologous gene-corrected hiPSCs and hiPSCs from healthy individuals. Patient organoids show decreased levels of CRB1 and NOTCH1 expression at the retinal outer limiting membrane. Proximity ligation assays show that human CRB1 and NOTCH1 can interact via their extracellular domains. CRB1 patient organoids feature increased levels of WDFY1+ vesicles, fewer RAB11A+ recycling endosomes, decreased VPS35 retromer complex components, and more degradative endolysosomal compartments relative to isogenic control organoids. Taken together, our data demonstrate that patient-derived retinal organoids enable modeling of retinal degeneration and highlight the importance of CRB1 in early endosome maturation receptor recycling in the retina.
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Affiliation(s)
- Thilo M Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Peter M J Quinn
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Lucie P Pellissier
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, the Netherlands
| | - Aat A Mulder
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Aldo Jongejan
- Bioinformatics Laboratory, Epidemiology & Data Science, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands
| | - Xuefei Lu
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Nanda Boon
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Daniëlle Koot
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | - Hind Almushattat
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands
| | | | - Rogier M Vos
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, the Netherlands
| | - Edward J Bradley
- Department of Genome Analysis, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands
| | - Christian Freund
- Leiden University Medical Center hiPSC Hotel, Leiden 2333 ZA, the Netherlands
| | - Harald M M Mikkers
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands; Leiden University Medical Center hiPSC Hotel, Leiden 2333 ZA, the Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Centers, Academic Medical Center, University of Amsterdam, Amsterdam 1000 AE, the Netherlands
| | - Perry D Moerland
- Bioinformatics Laboratory, Epidemiology & Data Science, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands
| | - Frank Baas
- Department of Genome Analysis, Amsterdam University Medical Centers, Amsterdam 1105 AZ, the Netherlands; Department of Clinical Genetics/LDGA, Leiden University Medical Center, Leiden 2333 ZA, the Netherlands
| | - Abraham J Koster
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Jacques Neefjes
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Ilana Berlin
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Carolina R Jost
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), Leiden 2300 RC, the Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden 2333 ZA, the Netherlands; Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam 1105 BA, the Netherlands.
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15
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Minckley TF, Salvagio LA, Fudge DH, Verhey K, Markus SM, Qin Y. Zn2+ decoration of microtubules arrests axonal transport and displaces tau, doublecortin, and MAP2C. J Cell Biol 2023; 222:e202208121. [PMID: 37326602 PMCID: PMC10276529 DOI: 10.1083/jcb.202208121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 03/31/2023] [Accepted: 05/11/2023] [Indexed: 06/17/2023] Open
Abstract
Intracellular Zn2+ concentrations increase via depolarization-mediated influx or intracellular release, but the immediate effects of Zn2+ signals on neuron function are not fully understood. By simultaneous recording of cytosolic Zn2+ and organelle motility, we find that elevated Zn2+ (IC50 ≈ 5-10 nM) reduces both lysosomal and mitochondrial motility in primary rat hippocampal neurons and HeLa cells. Using live-cell confocal microscopy and in vitro single-molecule TIRF imaging, we reveal that Zn2+ inhibits activity of motor proteins (kinesin and dynein) without disrupting their microtubule binding. Instead, Zn2+ directly binds to microtubules and selectively promotes detachment of tau, DCX, and MAP2C, but not MAP1B, MAP4, MAP7, MAP9, or p150glued. Bioinformatic predictions and structural modeling show that the Zn2+ binding sites on microtubules partially overlap with the microtubule binding sites of tau, DCX, dynein, and kinesin. Our results reveal that intraneuronal Zn2+ regulates axonal transport and microtubule-based processes by interacting with microtubules.
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Affiliation(s)
- Taylor F. Minckley
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | | | - Dylan H. Fudge
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Kristen Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Steven M. Markus
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO, USA
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16
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Smith G, Sweeney ST, O’Kane CJ, Prokop A. How neurons maintain their axons long-term: an integrated view of axon biology and pathology. Front Neurosci 2023; 17:1236815. [PMID: 37564364 PMCID: PMC10410161 DOI: 10.3389/fnins.2023.1236815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Axons are processes of neurons, up to a metre long, that form the essential biological cables wiring nervous systems. They must survive, often far away from their cell bodies and up to a century in humans. This requires self-sufficient cell biology including structural proteins, organelles, and membrane trafficking, metabolic, signalling, translational, chaperone, and degradation machinery-all maintaining the homeostasis of energy, lipids, proteins, and signalling networks including reactive oxygen species and calcium. Axon maintenance also involves specialised cytoskeleton including the cortical actin-spectrin corset, and bundles of microtubules that provide the highways for motor-driven transport of components and organelles for virtually all the above-mentioned processes. Here, we aim to provide a conceptual overview of key aspects of axon biology and physiology, and the homeostatic networks they form. This homeostasis can be derailed, causing axonopathies through processes of ageing, trauma, poisoning, inflammation or genetic mutations. To illustrate which malfunctions of organelles or cell biological processes can lead to axonopathies, we focus on axonopathy-linked subcellular defects caused by genetic mutations. Based on these descriptions and backed up by our comprehensive data mining of genes linked to neural disorders, we describe the 'dependency cycle of local axon homeostasis' as an integrative model to explain why very different causes can trigger very similar axonopathies, providing new ideas that can drive the quest for strategies able to battle these devastating diseases.
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Affiliation(s)
- Gaynor Smith
- Cardiff University, School of Medicine, College of Biomedical and Life Sciences, Cardiff, United Kingdom
| | - Sean T. Sweeney
- Department of Biology, University of York and York Biomedical Research Institute, York, United Kingdom
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, The University of Manchester, Manchester, United Kingdom
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17
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Dou D, Smith EM, Evans CS, Boecker CA, Holzbaur ELF. Regulatory imbalance between LRRK2 kinase, PPM1H phosphatase, and ARF6 GTPase disrupts the axonal transport of autophagosomes. Cell Rep 2023; 42:112448. [PMID: 37133994 PMCID: PMC10304398 DOI: 10.1016/j.celrep.2023.112448] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 03/15/2023] [Accepted: 04/13/2023] [Indexed: 05/04/2023] Open
Abstract
Gain-of-function mutations in the LRRK2 gene cause Parkinson's disease (PD), increasing phosphorylation of RAB GTPases through hyperactive kinase activity. We find that LRRK2-hyperphosphorylated RABs disrupt the axonal transport of autophagosomes by perturbing the coordinated regulation of cytoplasmic dynein and kinesin. In iPSC-derived human neurons, knockin of the strongly hyperactive LRRK2-p.R1441H mutation causes striking impairments in autophagosome transport, inducing frequent directional reversals and pauses. Knockout of the opposing protein phosphatase 1H (PPM1H) phenocopies the effect of hyperactive LRRK2. Overexpression of ADP-ribosylation factor 6 (ARF6), a GTPase that acts as a switch for selective activation of dynein or kinesin, attenuates transport defects in both p.R1441H knockin and PPM1H knockout neurons. Together, these findings support a model where a regulatory imbalance between LRRK2-hyperphosphorylated RABs and ARF6 induces an unproductive "tug-of-war" between dynein and kinesin, disrupting processive autophagosome transport. This disruption may contribute to PD pathogenesis by impairing the essential homeostatic functions of axonal autophagy.
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Affiliation(s)
- Dan Dou
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA; Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Erin M Smith
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Chantell S Evans
- Duke University Medical Center, Duke University, Durham, NC 27710, USA
| | - C Alexander Boecker
- Department of Neurology, University Medical Center Goettingen, 37077 Goettingen, Germany.
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD 20815, USA; Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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18
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Muraleedharan A, Vanderperre B. The endo-lysosomal system in Parkinson's disease: expanding the horizon. J Mol Biol 2023:168140. [PMID: 37148997 DOI: 10.1016/j.jmb.2023.168140] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/22/2023] [Accepted: 04/27/2023] [Indexed: 05/08/2023]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease, and its prevalence is increasing with age. A wealth of genetic evidence indicates that the endo-lysosomal system is a major pathway driving PD pathogenesis with a growing number of genes encoding endo-lysosomal proteins identified as risk factors for PD, making it a promising target for therapeutic intervention. However, detailed knowledge and understanding of the molecular mechanisms linking these genes to the disease are available for only a handful of them (e.g. LRRK2, GBA1, VPS35). Taking on the challenge of studying poorly characterized genes and proteins can be daunting, due to the limited availability of tools and knowledge from previous literature. This review aims at providing a valuable source of molecular and cellular insights into the biology of lesser-studied PD-linked endo-lysosomal genes, to help and encourage researchers in filling the knowledge gap around these less popular genetic players. Specific endo-lysosomal pathways discussed range from endocytosis, sorting, and vesicular trafficking to the regulation of membrane lipids of these membrane-bound organelles and the specific enzymatic activities they contain. We also provide perspectives on future challenges that the community needs to tackle and propose approaches to move forward in our understanding of these poorly studied endo-lysosomal genes. This will help harness their potential in designing innovative and efficient treatments to ultimately re-establish neuronal homeostasis in PD but also other diseases involving endo-lysosomal dysfunction.
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Affiliation(s)
- Amitha Muraleedharan
- Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois and Biological Sciences Department, Université du Québec à Montréal
| | - Benoît Vanderperre
- Centre d'Excellence en Recherche sur les Maladies Orphelines - Fondation Courtois and Biological Sciences Department, Université du Québec à Montréal
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19
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Masato A, Plotegher N, Terrin F, Sandre M, Faustini G, Thor A, Adams S, Berti G, Cogo S, De Lazzari F, Fontana CM, Martinez PA, Strong R, Bandopadhyay R, Bisaglia M, Bellucci A, Greggio E, Dalla Valle L, Boassa D, Bubacco L. DOPAL initiates αSynuclein-dependent impaired proteostasis and degeneration of neuronal projections in Parkinson's disease. NPJ Parkinsons Dis 2023; 9:42. [PMID: 36966140 PMCID: PMC10039907 DOI: 10.1038/s41531-023-00485-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/06/2023] [Indexed: 03/27/2023] Open
Abstract
Dopamine dyshomeostasis has been acknowledged among the determinants of nigrostriatal neuron degeneration in Parkinson's disease (PD). Several studies in experimental models and postmortem PD patients underlined increasing levels of the dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL), which is highly reactive towards proteins. DOPAL has been shown to covalently modify the presynaptic protein αSynuclein (αSyn), whose misfolding and aggregation represent a major trait of PD pathology, triggering αSyn oligomerization in dopaminergic neurons. Here, we demonstrated that DOPAL elicits αSyn accumulation and hampers αSyn clearance in primary neurons. DOPAL-induced αSyn buildup lessens neuronal resilience, compromises synaptic integrity, and overwhelms protein quality control pathways in neurites. The progressive decline of neuronal homeostasis further leads to dopaminergic neuron loss and motor impairment, as showed in in vivo models. Finally, we developed a specific antibody which detected increased DOPAL-modified αSyn in human striatal tissues from idiopathic PD patients, corroborating the translational relevance of αSyn-DOPAL interplay in PD neurodegeneration.
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Affiliation(s)
- Anna Masato
- Department of Biology, University of Padova, Padova, 35131, Italy
| | - Nicoletta Plotegher
- Department of Biology, University of Padova, Padova, 35131, Italy
- Centro Studi per la Neurodegenerazione (CESNE), University of Padova, Padova, Italy
| | - Francesca Terrin
- Department of Biology, University of Padova, Padova, 35131, Italy
| | - Michele Sandre
- Department of Neuroscience, University of Padova, Padova, 35131, Italy
| | - Gaia Faustini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, 25123, Italy
| | - Andrea Thor
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093-0608, USA
- National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, CA, 92093-0608, USA
| | - Stephen Adams
- Department of Pharmacology, University of California San Diego, La Jolla, CA, 92093-0608, USA
| | - Giulia Berti
- Department of Biology, University of Padova, Padova, 35131, Italy
| | - Susanna Cogo
- Department of Biology, University of Padova, Padova, 35131, Italy
| | | | | | - Paul Anthony Martinez
- Department of Pharmacology and Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- South Texas Veterans Health Care Network, San Antonio, TX, 78229, USA
| | - Randy Strong
- Department of Pharmacology and Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, 78229, USA
- South Texas Veterans Health Care Network, San Antonio, TX, 78229, USA
| | - Rina Bandopadhyay
- Reta Lila Weston Institute of Neurological Studies, UCL Queen Square Institute of Neurology, London, WC1N 1PJ, UK
| | - Marco Bisaglia
- Department of Biology, University of Padova, Padova, 35131, Italy
- Centro Studi per la Neurodegenerazione (CESNE), University of Padova, Padova, Italy
| | - Arianna Bellucci
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, 25123, Italy
| | - Elisa Greggio
- Department of Biology, University of Padova, Padova, 35131, Italy
- Centro Studi per la Neurodegenerazione (CESNE), University of Padova, Padova, Italy
| | | | - Daniela Boassa
- Department of Neurosciences, University of California San Diego, La Jolla, CA, 92093-0608, USA.
- National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, CA, 92093-0608, USA.
| | - Luigi Bubacco
- Department of Biology, University of Padova, Padova, 35131, Italy.
- Centro Studi per la Neurodegenerazione (CESNE), University of Padova, Padova, Italy.
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20
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Mamais A, Wallings R, Rocha EM. Disease mechanisms as subtypes: Lysosomal dysfunction in the endolysosomal Parkinson's disease subtype. HANDBOOK OF CLINICAL NEUROLOGY 2023; 193:33-51. [PMID: 36803821 DOI: 10.1016/b978-0-323-85555-6.00009-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Parkinson's disease (PD) remains one of the most prevalent neurodegenerative disorders. It has become increasingly recognized that PD is not one disease but a constellation of many, with distinct cellular mechanisms driving pathology and neuronal loss in each given subtype. Endolysosomal trafficking and lysosomal degradation are crucial to maintain neuronal homeostasis and vesicular trafficking. It is clear that deficits in endolysosomal signaling data support the existence of an endolysosomal PD subtype. This chapter describes how cellular pathways involved in endolysosomal vesicular trafficking and lysosomal degradation in neurons and immune cells can contribute to PD. Last, as inflammatory processes including phagocytosis and cytokine release are central in glia-neuron interactions, a spotlight on the role of neuroinflammation plays in the pathogenesis of this PD subtype is also explored.
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Affiliation(s)
- Adamantios Mamais
- Department of Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Center for Translational Research in Neurodegenerative disease, University of Florida, Gainesville, FL, United States
| | - Rebecca Wallings
- Department of Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Center for Translational Research in Neurodegenerative disease, University of Florida, Gainesville, FL, United States
| | - Emily M Rocha
- Pittsburgh Institute for Neurodegenerative Diseases and Department of Neurology, University of Pittsburgh, Pittsburgh, PA, United States.
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21
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Yang Y, Yang J, Liang Y, Zhang G, Cai Z, Zhang Y, Lin H, Tan M. Rab3A interacts with spastin to regulate neurite outgrowth in hippocampal neurons. Biochem Biophys Res Commun 2023; 643:77-87. [PMID: 36587525 DOI: 10.1016/j.bbrc.2022.12.066] [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: 12/07/2022] [Revised: 12/19/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
Investigating novel mechanisms of neurite outgrowth via cytoskeleton is critical for developing therapeutic strategies against neural disorders. Rab3A is a vesicle-related protein distributed throughout the nervous system, but the detailed mechanism related to cytoskeleton remains largely unknown. Our previous reports show that spastin serves microtubule to regulate neurite outgrowth. Here, we asked whether Rab3A could function via modulating spastin during neuronal development. The results revealed that Rab3A colocalized with spastin in cultured hippocampal neurons. Immunoprecipitation assays showed that Rab3A physically interacted with spastin in rat brain lysates. Rab3A overexpression significantly induced spastin degradation; this effect was reversed by leupeptin- or MG-132- administration, suggesting the lysosomal and ubiquitin-mediated degradation system. Immunofluorescence staining further confirmed that Rab3A and spastin immune-colocalized with the lysosome marker lysotracker. In COS7 cells, Rab3A overexpression significantly downregulated spastin expression and abolished the spastin-mediated microtubule severing. Furthermore, overexpression inhibited while genetic knockdown of Rab3A promoted neurite outgrowth. However, this inhibitory effect on neurite outgrowth in hippocampal neurons could be reversed via co-transfection of spastin, indicating that Rab3A functions via its interaction protein spastin. In general, our data identify an interaction between Rab3A and spastin, and this interaction affects the protein stability of spastin and eliminates its microtubule severing function, thereby modulating neurite outgrowth.
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Affiliation(s)
- Yuhao Yang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Jie Yang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Yaozhong Liang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Guowei Zhang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Zhenbin Cai
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Yunlong Zhang
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China
| | - Hongsheng Lin
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China.
| | - Minghui Tan
- Department of Orthopaedics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, 510630, China.
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22
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Cason SE, Holzbaur EL. Axonal transport of autophagosomes is regulated by dynein activators JIP3/JIP4 and ARF/RAB GTPases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.28.526044. [PMID: 36747648 PMCID: PMC9901177 DOI: 10.1101/2023.01.28.526044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Neuronal autophagosomes, "self-eating" degradative organelles, form at presynaptic sites in the distal axon and are transported to the soma to recycle their cargo. During transit, autophagic vacuoles (AVs) mature through fusion with lysosomes to acquire the enzymes necessary to breakdown their cargo. AV transport is driven primarily by the microtubule motor cytoplasmic dynein in concert with dynactin and a series of activating adaptors that change depending on organelle maturation state. The transport of mature AVs is regulated by the scaffolding proteins JIP3 and JIP4, both of which activate dynein motility in vitro. AV transport is also regulated by ARF6 in a GTP-dependent fashion. While GTP-bound ARF6 promotes the formation of the JIP3/4-dynein-dynactin complex, RAB10 competes with the activity of this complex by increasing kinesin recruitment to axonal AVs and lysosomes. These interactions highlight the complex coordination of motors regulating organelle transport in neurons.
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Affiliation(s)
- Sydney E. Cason
- Department of Physiology, University of Pennsylvania
- Neuroscience Graduate Group, University of Pennsylvania
- Pennsylvania Muscle Institute, University of Pennsylvania
| | - Erika L.F. Holzbaur
- Department of Physiology, University of Pennsylvania
- Neuroscience Graduate Group, University of Pennsylvania
- Pennsylvania Muscle Institute, University of Pennsylvania
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23
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Kick GR, Whiting REH, Ota-Kuroki J, Castaner LJ, Morgan-Jack B, Sabol JC, Meiman EJ, Ortiz F, Katz ML. Intravitreal gene therapy preserves retinal function in a canine model of CLN2 neuronal ceroid lipofuscinosis. Exp Eye Res 2023; 226:109344. [PMID: 36509165 PMCID: PMC9839638 DOI: 10.1016/j.exer.2022.109344] [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: 08/26/2022] [Revised: 11/02/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
CLN2 neuronal ceroid lipofuscinosis is a rare hereditary neurodegenerative disorder characterized by deleterious sequence variants in TPP1 that result in reduced or abolished function of the lysosomal enzyme tripeptidyl peptidase 1 (TPP1). Children with this disorder experience progressive neurological decline and vision loss starting around 2-4 years of age. Ocular disease is characterized by progressive retinal degeneration and impaired retinal function culminating in total loss of vision. Similar retinal pathology occurs in a canine model of CLN2 disease with a null variant in TPP1. A study using the dog model was performed to evaluate the efficacy of ocular gene therapy to provide a continuous, long-term source of human TPP1 (hTPP1) to the retina, inhibit retinal degeneration and preserve retinal function. TPP1-/- dogs received an intravitreal injection of 1 x 1012 viral genomes of AAV2.CAG.hTPP1 in one eye and AAV2.CAG.GFP in the contralateral eye at 4 months of age. Ophthalmic exams, in vivo ocular imaging and electroretinography were repeated monthly to assess retinal structure and function. Retinal morphology, hTPP1 and GFP expression in the retina, optic nerve and lateral geniculate nucleus, and hTPP1 concentrations in the vitreous were evaluated after the dogs were euthanized at end stage neurological disease at approximately 10 months of age. Intravitreal administration of AAV2.CAG.hTPP1 resulted in stable, widespread expression of hTPP1 throughout the inner retina, prevented disease-related declines in retinal function and inhibited disease-related cell loss and storage body accumulation in the retina for at least 6 months. Uveitis occurred in eyes treated with the hTPP1 vector, but this did not prevent therapeutic efficacy. The severity of the uveitis was ameliorated with anti-inflammatory treatments. These results indicate that a single intravitreal injection of AAV2.CAG.hTPP1 is an effective treatment to inhibit ocular disease progression in canine CLN2 disease.
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Affiliation(s)
- Grace Robinson Kick
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Rebecca E H Whiting
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Juri Ota-Kuroki
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Leilani J Castaner
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Brandie Morgan-Jack
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Julianna C Sabol
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Elizabeth J Meiman
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Francheska Ortiz
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA
| | - Martin L Katz
- Neurodegenerative Diseases Research Laboratory, University of Missouri School of Medicine, Columbia, MO, USA.
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24
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Endosomal Transport to Lysosomes and the Trans-Golgi Network in Neurons and Other Cells: Visualizing Maturational Flux. Methods Mol Biol 2022; 2557:595-618. [PMID: 36512240 DOI: 10.1007/978-1-0716-2639-9_36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
High-level microscopy enables the comprehensive study of dynamic intracellular processes. Here we describe a toolkit of combinatorial approaches for fixed cell imaging and live cell imaging to investigate the interactions along the trans-Golgi network (TGN)-endosome-lysosome transport axis, which underlie the maturation of endosomal compartments and degradative flux. For fixed cell approaches, we specifically highlight how choices of permeabilization conditions, antibody selection, and antibody multiplexing affect interpretation of results. For live cell approaches, we emphasize the use of sensors that read out pH and degradative capacity in combination with endosomal identity for elucidating dynamic compartment changes.
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25
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Sun C, Schuman EM. Logistics of neuronal protein turnover: Numbers and mechanisms. Mol Cell Neurosci 2022; 123:103793. [PMID: 36396040 DOI: 10.1016/j.mcn.2022.103793] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Research in the past twenty years or so has revealed that neurons synthesize and degrade proteins at their synapses to enable synaptic proteome remodelling on demand and in real-time. Here we provide a quantitative overview of the decentralized neuronal protein-turnover logistics. We first analyse the huge neuronal protein turnover demand that arises from subcellular compartments outside the cell body, followed by an overview of key quantities and modulation strategies in neuronal protein turnover logistics. In the end, we briefly review recent progress in neuronal local protein synthesis and summarize diverse protein-degradation mechanisms that are found near synapses.
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Affiliation(s)
- Chao Sun
- Max Planck Institute for Brain Research, 60438 Frankfurt am Main, Germany
| | - Erin M Schuman
- Max Planck Institute for Brain Research, 60438 Frankfurt am Main, Germany.
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26
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Garbouchian A, Montgomery AC, Gilbert SP, Bentley M. KAP is the neuronal organelle adaptor for Kinesin-2 KIF3AB and KIF3AC. Mol Biol Cell 2022; 33:ar133. [PMID: 36200888 PMCID: PMC9727798 DOI: 10.1091/mbc.e22-08-0336] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Kinesin-driven organelle transport is crucial for neuron development and maintenance, yet the mechanisms by which kinesins specifically bind their organelle cargoes remain undefined. In contrast to other transport kinesins, the neuronal function and specific organelle adaptors of heterodimeric Kinesin-2 family members KIF3AB and KIF3AC remain unknown. We developed a novel microscopy-based assay to define protein-protein interactions in intact neurons. The experiments found that both KIF3AB and KIF3AC bind kinesin-associated protein (KAP). These interactions are mediated by the distal C-terminal tail regions and not the coiled-coil domain. We used live-cell imaging in cultured hippocampal neurons to define the localization and trafficking parameters of KIF3AB and KIF3AC organelle populations. We discovered that KIF3AB/KAP and KIF3AC/KAP bind the same organelle populations and defined their transport parameters in axons and dendrites. The results also show that ∼12% of KIF3 organelles contain the RNA-binding protein adenomatous polyposis coli. These data point toward a model in which KIF3AB and KIF3AC use KAP as their neuronal organelle adaptor and that these kinesins mediate transport of a range of organelles.
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Affiliation(s)
- Alex Garbouchian
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Andrew C. Montgomery
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Susan P. Gilbert
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Marvin Bentley
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180,*Address correspondence to: Marvin Bentley ()
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27
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Kulkarni VV, Stempel MH, Anand A, Sidibe DK, Maday S. Retrograde Axonal Autophagy and Endocytic Pathways Are Parallel and Separate in Neurons. J Neurosci 2022; 42:8524-8541. [PMID: 36167783 PMCID: PMC9665928 DOI: 10.1523/jneurosci.1292-22.2022] [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: 06/30/2022] [Revised: 09/15/2022] [Accepted: 09/20/2022] [Indexed: 11/21/2022] Open
Abstract
Autophagy and endocytic trafficking are two key pathways that regulate the composition and integrity of the neuronal proteome. Alterations in these pathways are sufficient to cause neurodevelopmental and neurodegenerative disorders. Thus, defining how autophagy and endocytic pathways are organized in neurons remains a key area of investigation. These pathways share many features and converge on lysosomes for cargo degradation, but what remains unclear is the degree to which the identity of each pathway is preserved in each compartment of the neuron. Here, we elucidate the degree of intersection between autophagic and endocytic pathways in axons of primary mouse cortical neurons of both sexes. Using microfluidic chambers, we labeled newly-generated bulk endosomes and signaling endosomes in the distal axon, and systematically tracked their trajectories, molecular composition, and functional characteristics relative to autophagosomes. We find that newly-formed endosomes and autophagosomes both undergo retrograde transport in the axon, but as distinct organelle populations. Moreover, these pathways differ in their degree of acidification and association with molecular determinants of organelle maturation. These results suggest that the identity of autophagic and newly endocytosed organelles is preserved for the length of the axon. Lastly, we find that expression of a pathogenic form of α-synuclein, a protein enriched in presynaptic terminals, increases merging between autophagic and endocytic pathways. Thus, aberrant merging of these pathways may represent a mechanism contributing to neuronal dysfunction in Parkinson's disease (PD) and related α-synucleinopathies.SIGNIFICANCE STATEMENT Autophagy and endocytic trafficking are retrograde pathways in neuronal axons that fulfill critical degradative and signaling functions. These pathways share many features and converge on lysosomes for cargo degradation, but the extent to which the identity of each pathway is preserved in axons is unclear. We find that autophagosomes and endosomes formed in the distal axon undergo retrograde transport to the soma in parallel and separate pathways. These pathways also have distinct maturation profiles along the mid-axon, further highlighting differences in the potential fate of transported cargo. Strikingly, expression of a pathogenic variant of α-synuclein increases merging between autophagic and endocytic pathways, suggesting that mis-sorting of axonal cargo may contribute to neuronal dysfunction in Parkinson's disease (PD) and related α-synucleinopathies.
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Affiliation(s)
- Vineet Vinay Kulkarni
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Max Henry Stempel
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Anip Anand
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - David Kader Sidibe
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
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28
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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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29
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Cason SE, Mogre SS, Holzbaur ELF, Koslover EF. Spatiotemporal analysis of axonal autophagosome-lysosome dynamics reveals limited fusion events and slow maturation. Mol Biol Cell 2022; 33:ar123. [PMID: 36044338 PMCID: PMC9634976 DOI: 10.1091/mbc.e22-03-0111] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Macroautophagy is a homeostatic process required to clear cellular waste. Neuronal autophagosomes form constitutively in the distal tip of the axon and are actively transported toward the soma, with cargo degradation initiated en route. Cargo turnover requires autophagosomes to fuse with lysosomes to acquire degradative enzymes; however, directly imaging these fusion events in the axon is impractical. Here we use a quantitative model, parameterized and validated using data from primary hippocampal neurons, to explore the autophagosome maturation process. We demonstrate that retrograde autophagosome motility is independent of fusion and that most autophagosomes fuse with only a few lysosomes during axonal transport. Our results indicate that breakdown of the inner autophagosomal membrane is much slower in neurons than in nonneuronal cell types, highlighting the importance of this late maturation step. Together, rigorous quantitative measurements and mathematical modeling elucidate the dynamics of autophagosome-lysosome interaction and autophagosomal maturation in the axon.
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Affiliation(s)
- Sydney E. Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Saurabh S. Mogre
- Department of Physics, University of California, San Diego, La Jolla, CA 92093
| | | | - Elena F. Koslover
- Department of Physics, University of California, San Diego, La Jolla, CA 92093,*Address correspondence to: Elena F. Koslover ()
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30
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Huang N, Sheng ZH. Microfluidic devices as model platforms of CNS injury-ischemia to study axonal regeneration by regulating mitochondrial transport and bioenergetic metabolism. CELL REGENERATION 2022; 11:33. [PMID: 36184647 PMCID: PMC9527262 DOI: 10.1186/s13619-022-00138-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/28/2022] [Indexed: 11/10/2022]
Abstract
Central nervous system (CNS) neurons typically fail to regenerate their axons after injury leading to neurological impairment. Axonal regeneration is a highly energy-demanding cellular program that requires local mitochondria to supply most energy within injured axons. Recent emerging lines of evidence have started to reveal that injury-triggered acute mitochondrial damage and local energy crisis contribute to the intrinsic energetic restriction that accounts for axon regeneration failure in the CNS. Characterizing and reprogramming bioenergetic signaling and mitochondrial maintenance after axon injury-ischemia is fundamental for developing therapeutic strategies that can restore local energy metabolism and thus facilitate axon regeneration. Therefore, establishing reliable and reproducible neuronal model platforms is critical for assessing axonal energetic metabolism and regeneration capacity after injury-ischemia. In this focused methodology article, we discuss recent advances in applying cutting-edge microfluidic chamber devices in combination with state-of-the-art live-neuron imaging tools to monitor axonal regeneration, mitochondrial transport, bioenergetic metabolism, and local protein synthesis in response to injury-ischemic stress in mature CNS neurons.
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Affiliation(s)
- Ning Huang
- grid.94365.3d0000 0001 2297 5165Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706 USA ,grid.43169.390000 0001 0599 1243Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, Xi’an, 710061 Shaanxi China ,grid.43169.390000 0001 0599 1243Institute of Neuroscience, Translational Medicine Institute, Xi’an Jiaotong University Health Science Center, Xi’an, 710061 Shaanxi China
| | - Zu-Hang Sheng
- grid.94365.3d0000 0001 2297 5165Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Room 2B-215, 35 Convent Drive, Bethesda, MD 20892-3706 USA
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31
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Transport-dependent maturation of organelles in neurons. Curr Opin Cell Biol 2022; 78:102121. [PMID: 36030563 DOI: 10.1016/j.ceb.2022.102121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 07/15/2022] [Indexed: 01/31/2023]
Abstract
Some organelles show a spatial gradient of maturation along the neuronal process where more mature organelles are found closer to the cell body. This gradient is set up by progressive maturation steps that are aided by differential organelle distribution as well as transport. Autophagosomes and endosomes mature as they acquire lysosomal membrane proteins and decrease their luminal pH as they are retrogradely transported towards the cell body. The acquisition of lysosomal proteins along the neuronal processes likely occurs through fusion or membrane exchange events with Golgi-derived donor transport carriers that are transported anterogradely from the cell body. The mechanisms by which endosomes and autophagosomes mature might be applicable to other organelles that are transported along neuronal processes. Defects in axonal transport may also contribute to the accumulation of immature organelles in neurons. Such accumulations have been seen in neurons of neurodegenerative models.
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32
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The compartmentalised nature of neuronal mitophagy: molecular insights and implications. Expert Rev Mol Med 2022; 24:e38. [PMID: 36172898 PMCID: PMC9884780 DOI: 10.1017/erm.2022.31] [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] [Indexed: 01/11/2023]
Abstract
The maintenance of a healthy mitochondrial network and the ability to adjust organelle population in response to internal or external stimuli are essential for the function and the survival of eukaryotic cells. Over the last two decades several studies have demonstrated the paramount importance of mitophagy, a selective form of autophagy that removes damaged and/or superfluous organelles, in organismal physiology. Post-mitotic neuronal cells are particularly vulnerable to mitochondrial damage, and mitophagy impairment has emerged as a causative factor in multiple neurodegenerative pathologies, including Alzheimer's disease and Parkinson's disease among others. Although mitochondrial turnover is a multifaceted process, neurons have to tackle additional complications, arising from their pronounced bioenergetic demands and their unique architecture and cellular polarisation that render the degradation of distal organelles challenging. Mounting evidence indicates that despite the functional conservation of mitophagy pathways, the unique features of neuronal physiology have led to the adaptation of compartmentalised solutions, which serve to ensure seamless mitochondrial removal in every part of the cell. In this review, we summarise the current knowledge concerning the molecular mechanisms that mediate mitophagy compartmentalisation and discuss their implications in various human pathologies.
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33
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Shi J, Xu J, Li Y, Li B, Ming H, Nice EC, Huang C, Li Q, Wang C. Drug repurposing in cancer neuroscience: From the viewpoint of the autophagy-mediated innervated niche. Front Pharmacol 2022; 13:990665. [PMID: 36105204 PMCID: PMC9464986 DOI: 10.3389/fphar.2022.990665] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Based on the bidirectional interactions between neurology and cancer science, the burgeoning field “cancer neuroscience” has been proposed. An important node in the communications between nerves and cancer is the innervated niche, which has physical contact with the cancer parenchyma or nerve located in the proximity of the tumor. In the innervated niche, autophagy has recently been reported to be a double-edged sword that plays a significant role in maintaining homeostasis. Therefore, regulating the innervated niche by targeting the autophagy pathway may represent a novel therapeutic strategy for cancer treatment. Drug repurposing has received considerable attention for its advantages in cost-effectiveness and safety. The utilization of existing drugs that potentially regulate the innervated niche via the autophagy pathway is therefore a promising pharmacological approach for clinical practice and treatment selection in cancer neuroscience. Herein, we present the cancer neuroscience landscape with an emphasis on the crosstalk between the innervated niche and autophagy, while also summarizing the underlying mechanisms of candidate drugs in modulating the autophagy pathway. This review provides a strong rationale for drug repurposing in cancer treatment from the viewpoint of the autophagy-mediated innervated niche.
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Affiliation(s)
- Jiayan Shi
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Jia Xu
- Department of Pharmacology, Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, China
| | - Yang Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Bowen Li
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Hui Ming
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Edouard C. Nice
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC, Australia
| | - Canhua Huang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, and West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Qifu Li
- Department of Neurology and Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, The First Affiliated Hospital, Hainan Medical University, Haikou, China
- *Correspondence: Qifu Li, ; Chuang Wang,
| | - Chuang Wang
- Department of Pharmacology, Provincial Key Laboratory of Pathophysiology, Ningbo University School of Medicine, Ningbo, China
- *Correspondence: Qifu Li, ; Chuang Wang,
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34
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Sidibe DK, Vogel MC, Maday S. Organization of the autophagy pathway in neurons. Curr Opin Neurobiol 2022; 75:102554. [PMID: 35649324 PMCID: PMC9990471 DOI: 10.1016/j.conb.2022.102554] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/28/2022] [Accepted: 04/12/2022] [Indexed: 01/18/2023]
Abstract
Macroautophagy (hereafter referred to as autophagy) is an essential quality-control pathway in neurons, which face unique functional and morphological challenges in maintaining the integrity of organelles and the proteome. To overcome these challenges, neurons have developed compartment-specific pathways for autophagy. In this review, we discuss the organization of the autophagy pathway, from autophagosome biogenesis, trafficking, to clearance, in the neuron. We dissect the compartment-specific mechanisms and functions of autophagy in axons, dendrites, and the soma. Furthermore, we highlight examples of how steps along the autophagy pathway are impaired in the context of aging and neurodegenerative disease, which underscore the critical importance of autophagy in maintaining neuronal function and survival.
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Affiliation(s)
- David K Sidibe
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Maria C Vogel
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sandra Maday
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA.
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35
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Seitkazina A, Kim KH, Fagan E, Sung Y, Kim YK, Lim S. The Fate of Tau Aggregates Between Clearance and Transmission. Front Aging Neurosci 2022; 14:932541. [PMID: 35923541 PMCID: PMC9339952 DOI: 10.3389/fnagi.2022.932541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/22/2022] [Indexed: 11/30/2022] Open
Abstract
Neuronal accumulation of mis-folded tau is the pathological hallmark of multiple neurodegenerative disorders, including Alzheimer’s disease. Distinct from amyloid plaques, which appear simultaneously throughout the brain, tau pathology develops first in a specific brain region and then propagates to neuroanatomically connected brain regions, exacerbating the disease. Due to the implication in disease progression, prevention of tau transmission is recognized as an important therapeutic strategy that can halt disease progression in the brain. Recently, accumulating studies have demonstrated diverse cellular mechanisms associated with cell-to-cell transmission of tau. Once transmitted, mis-folded tau species act as a prion-like seed for native tau aggregation in the recipient neuron. In this review, we summarize the diverse cellular mechanisms associated with the secretion and uptake of tau, and highlight tau-trafficking receptors, which mediate tau clearance or cell-to-cell tau transmission.
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Affiliation(s)
- Assel Seitkazina
- Convergence Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, Korea Institute of Science and Technology (KIST) School, University of Science and Technology (UST), Seoul, South Korea
| | - Kyu Hyeon Kim
- Convergence Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, Korea Institute of Science and Technology (KIST) School, University of Science and Technology (UST), Seoul, South Korea
| | - Erin Fagan
- Department of Biological Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA, United States
| | - Yoonsik Sung
- Convergence Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, Korea Institute of Science and Technology (KIST) School, University of Science and Technology (UST), Seoul, South Korea
| | - Yun Kyung Kim
- Convergence Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science and Technology, Korea Institute of Science and Technology (KIST) School, University of Science and Technology (UST), Seoul, South Korea
- *Correspondence: Yun Kyung Kim,
| | - Sungsu Lim
- Convergence Research Center for Brain Science, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Sungsu Lim,
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Yap CC, Winckler B. Spatial regulation of endosomes in growing dendrites. Dev Biol 2022; 486:5-14. [PMID: 35306006 PMCID: PMC10646839 DOI: 10.1016/j.ydbio.2022.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 02/21/2022] [Accepted: 03/13/2022] [Indexed: 01/19/2023]
Abstract
Many membrane proteins are highly enriched in either dendrites or axons. This non-uniform distribution is a critical feature of neuronal polarity and underlies neuronal function. The molecular mechanisms responsible for polarized distribution of membrane proteins has been studied for some time and many answers have emerged. A less well studied feature of neurons is that organelles are also frequently non-uniformly distributed. For instance, EEA1-positive early endosomes are somatodendritic whereas synaptic vesicles are axonal. In addition, some organelles are present in both axons and dendrites, but not distributed uniformly along the processes. One well known example are lysosomes which are abundant in the soma and proximal dendrite, but sparse in the distal dendrite and the distal axon. The mechanisms that determine the spatial distribution of organelles along dendrites are only starting to be studied. In this review, we will discuss the cell biological mechanisms of how the distribution of diverse sets of endosomes along the proximal-distal axis of dendrites might be regulated. In particular, we will focus on the regulation of bulk homeostatic mechanisms as opposed to local regulation. We posit that immature dendrites regulate organelle motility differently from mature dendrites in order to spatially organize dendrite growth, branching and sculpting.
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37
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Selective motor activation in organelle transport along axons. Nat Rev Mol Cell Biol 2022; 23:699-714. [DOI: 10.1038/s41580-022-00491-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2022] [Indexed: 12/17/2022]
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Blanchette CR, Scalera AL, Harris KP, Zhao Z, Dresselhaus EC, Koles K, Yeh A, Apiki JK, Stewart BA, Rodal AA. Local regulation of extracellular vesicle traffic by the synaptic endocytic machinery. J Cell Biol 2022; 221:e202112094. [PMID: 35320349 PMCID: PMC8952828 DOI: 10.1083/jcb.202112094] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/14/2022] [Accepted: 02/28/2022] [Indexed: 02/01/2023] Open
Abstract
Neuronal extracellular vesicles (EVs) are locally released from presynaptic terminals, carrying cargoes critical for intercellular signaling and disease. EVs are derived from endosomes, but it is unknown how these cargoes are directed to the EV pathway rather than for conventional endolysosomal degradation. Here, we find that endocytic machinery plays an unexpected role in maintaining a release-competent pool of EV cargoes at synapses. Endocytic mutants, including nervous wreck (nwk), shibire/dynamin, and AP-2, unexpectedly exhibit local presynaptic depletion specifically of EV cargoes. Accordingly, nwk mutants phenocopy synaptic plasticity defects associated with loss of the EV cargo synaptotagmin-4 (Syt4) and suppress lethality upon overexpression of the EV cargo amyloid precursor protein (APP). These EV defects are genetically separable from canonical endocytic functions in synaptic vesicle recycling and synaptic growth. Endocytic machinery opposes the endosomal retromer complex to regulate EV cargo levels and acts upstream of synaptic cargo removal by retrograde axonal transport. Our data suggest a novel molecular mechanism that locally promotes cargo loading into synaptic EVs.
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Affiliation(s)
| | | | - Kathryn P. Harris
- Department of Biology, University of Toronto Mississauga, Mississauga, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Zechuan Zhao
- Department of Biology, Brandeis University, Waltham, MA
| | | | - Kate Koles
- Department of Biology, Brandeis University, Waltham, MA
| | - Anna Yeh
- Department of Biology, Brandeis University, Waltham, MA
| | | | - Bryan A. Stewart
- Department of Biology, University of Toronto Mississauga, Mississauga, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
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Barral DC, Staiano L, Guimas Almeida C, Cutler DF, Eden ER, Futter CE, Galione A, Marques ARA, Medina DL, Napolitano G, Settembre C, Vieira OV, Aerts JMFG, Atakpa‐Adaji P, Bruno G, Capuozzo A, De Leonibus E, Di Malta C, Escrevente C, Esposito A, Grumati P, Hall MJ, Teodoro RO, Lopes SS, Luzio JP, Monfregola J, Montefusco S, Platt FM, Polishchuck R, De Risi M, Sambri I, Soldati C, Seabra MC. Current methods to analyze lysosome morphology, positioning, motility and function. Traffic 2022; 23:238-269. [PMID: 35343629 PMCID: PMC9323414 DOI: 10.1111/tra.12839] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 01/09/2023]
Abstract
Since the discovery of lysosomes more than 70 years ago, much has been learned about the functions of these organelles. Lysosomes were regarded as exclusively degradative organelles, but more recent research has shown that they play essential roles in several other cellular functions, such as nutrient sensing, intracellular signalling and metabolism. Methodological advances played a key part in generating our current knowledge about the biology of this multifaceted organelle. In this review, we cover current methods used to analyze lysosome morphology, positioning, motility and function. We highlight the principles behind these methods, the methodological strategies and their advantages and limitations. To extract accurate information and avoid misinterpretations, we discuss the best strategies to identify lysosomes and assess their characteristics and functions. With this review, we aim to stimulate an increase in the quantity and quality of research on lysosomes and further ground-breaking discoveries on an organelle that continues to surprise and excite cell biologists.
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Affiliation(s)
- Duarte C. Barral
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de LisboaLisbonPortugal
| | - Leopoldo Staiano
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Institute for Genetic and Biomedical ResearchNational Research Council (CNR)MilanItaly
| | | | - Dan F. Cutler
- MRC Laboratory for Molecular Cell BiologyUniversity College LondonLondonUK
| | - Emily R. Eden
- University College London (UCL) Institute of OphthalmologyLondonUK
| | - Clare E. Futter
- University College London (UCL) Institute of OphthalmologyLondonUK
| | | | | | - Diego Luis Medina
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Medical Genetics Unit, Department of Medical and Translational ScienceFederico II UniversityNaplesItaly
| | - Gennaro Napolitano
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Medical Genetics Unit, Department of Medical and Translational ScienceFederico II UniversityNaplesItaly
| | - Carmine Settembre
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Clinical Medicine and Surgery DepartmentFederico II UniversityNaplesItaly
| | - Otília V. Vieira
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de LisboaLisbonPortugal
| | | | | | - Gemma Bruno
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | | | - Elvira De Leonibus
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Institute of Biochemistry and Cell Biology, CNRRomeItaly
| | - Chiara Di Malta
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Medical Genetics Unit, Department of Medical and Translational ScienceFederico II UniversityNaplesItaly
| | | | | | - Paolo Grumati
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Michael J. Hall
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de LisboaLisbonPortugal
| | - Rita O. Teodoro
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de LisboaLisbonPortugal
| | - Susana S. Lopes
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de LisboaLisbonPortugal
| | - J. Paul Luzio
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | | | | | | | | | - Maria De Risi
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Irene Sambri
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
- Medical Genetics Unit, Department of Medical and Translational ScienceFederico II UniversityNaplesItaly
| | - Chiara Soldati
- Telethon Institute of Genetics and Medicine (TIGEM)PozzuoliItaly
| | - Miguel C. Seabra
- CEDOC, NOVA Medical School, NMS, Universidade NOVA de LisboaLisbonPortugal
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Martucci LL, Cancela JM. Neurophysiological functions and pharmacological tools of acidic and non-acidic Ca2+ stores. Cell Calcium 2022; 104:102582. [DOI: 10.1016/j.ceca.2022.102582] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/07/2022] [Accepted: 03/23/2022] [Indexed: 02/08/2023]
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41
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Keren-Kaplan T, Sarić A, Ghosh S, Williamson CD, Jia R, Li Y, Bonifacino JS. RUFY3 and RUFY4 are ARL8 effectors that promote coupling of endolysosomes to dynein-dynactin. Nat Commun 2022; 13:1506. [PMID: 35314674 PMCID: PMC8938451 DOI: 10.1038/s41467-022-28952-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 02/18/2022] [Indexed: 11/10/2022] Open
Abstract
The small GTPase ARL8 associates with endolysosomes, leading to the recruitment of several effectors that couple endolysosomes to kinesins for anterograde transport along microtubules, and to tethering factors for eventual fusion with other organelles. Herein we report the identification of the RUN- and FYVE-domain-containing proteins RUFY3 and RUFY4 as ARL8 effectors that promote coupling of endolysosomes to dynein-dynactin for retrograde transport along microtubules. Using various methodologies, we find that RUFY3 and RUFY4 interact with both GTP-bound ARL8 and dynein-dynactin. In addition, we show that RUFY3 and RUFY4 promote concentration of endolysosomes in the juxtanuclear area of non-neuronal cells, and drive redistribution of endolysosomes from the axon to the soma in hippocampal neurons. The function of RUFY3 in retrograde transport contributes to the juxtanuclear redistribution of endolysosomes upon cytosol alkalinization. These studies thus identify RUFY3 and RUFY4 as ARL8-dependent, dynein-dynactin adaptors or regulators, and highlight the role of ARL8 in the control of both anterograde and retrograde endolysosome transport. Organellar transport is carefully regulated, and endolysosome localized ARL8 is important for kinesin recruitment and anterograde movement. Here, the authors show that RUFY3 and RUFY4 promote retrograde transport of endolysosomes by mediating interaction of ARL8 with dynein-dynactin.
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Gundelfinger ED, Karpova A, Pielot R, Garner CC, Kreutz MR. Organization of Presynaptic Autophagy-Related Processes. Front Synaptic Neurosci 2022; 14:829354. [PMID: 35368245 PMCID: PMC8968026 DOI: 10.3389/fnsyn.2022.829354] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Brain synapses pose special challenges on the quality control of their protein machineries as they are far away from the neuronal soma, display a high potential for plastic adaptation and have a high energy demand to fulfill their physiological tasks. This applies in particular to the presynaptic part where neurotransmitter is released from synaptic vesicles, which in turn have to be recycled and refilled in a complex membrane trafficking cycle. Pathways to remove outdated and damaged proteins include the ubiquitin-proteasome system acting in the cytoplasm as well as membrane-associated endolysosomal and the autophagy systems. Here we focus on the latter systems and review what is known about the spatial organization of autophagy and endolysomal processes within the presynapse. We provide an inventory of which components of these degradative systems were found to be present in presynaptic boutons and where they might be anchored to the presynaptic apparatus. We identify three presynaptic structures reported to interact with known constituents of membrane-based protein-degradation pathways and therefore may serve as docking stations. These are (i) scaffolding proteins of the cytomatrix at the active zone, such as Bassoon or Clarinet, (ii) the endocytic machinery localized mainly at the peri-active zone, and (iii) synaptic vesicles. Finally, we sketch scenarios, how presynaptic autophagic cargos are tagged and recruited and which cellular mechanisms may govern membrane-associated protein turnover in the presynapse.
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Affiliation(s)
- Eckart D. Gundelfinger
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Institute of Pharmacology and Toxicology, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- *Correspondence: Eckart D. Gundelfinger,
| | - Anna Karpova
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Rainer Pielot
- Institute of Pharmacology and Toxicology, Medical Faculty, Otto von Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Craig C. Garner
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
- Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Michael R. Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- Center for Molecular Neurobiology (ZMNH), University Hospital Hamburg-Eppendorf, Hamburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
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Grochowska KM, Andres‐Alonso M, Karpova A, Kreutz MR. The needs of a synapse—How local organelles serve synaptic proteostasis. EMBO J 2022; 41:e110057. [PMID: 35285533 PMCID: PMC8982616 DOI: 10.15252/embj.2021110057] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/24/2021] [Accepted: 02/10/2022] [Indexed: 12/12/2022] Open
Abstract
Synaptic function crucially relies on the constant supply and removal of neuronal membranes. The morphological complexity of neurons poses a significant challenge for neuronal protein transport since the machineries for protein synthesis and degradation are mainly localized in the cell soma. In response to this unique challenge, local micro‐secretory systems have evolved that are adapted to the requirements of neuronal membrane protein proteostasis. However, our knowledge of how neuronal proteins are synthesized, trafficked to membranes, and eventually replaced and degraded remains scarce. Here, we review recent insights into membrane trafficking at synaptic sites and into the contribution of local organelles and micro‐secretory pathways to synaptic function. We describe the role of endoplasmic reticulum specializations in neurons, Golgi‐related organelles, and protein complexes like retromer in the synthesis and trafficking of synaptic transmembrane proteins. We discuss the contribution of autophagy and of proteasome‐mediated and endo‐lysosomal degradation to presynaptic proteostasis and synaptic function, as well as nondegradative roles of autophagosomes and lysosomes in signaling and synapse remodeling. We conclude that the complexity of neuronal cyto‐architecture necessitates long‐distance protein transport that combines degradation with signaling functions.
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Affiliation(s)
- Katarzyna M Grochowska
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Maria Andres‐Alonso
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
| | - Anna Karpova
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
| | - Michael R Kreutz
- Leibniz Group “Dendritic Organelles and Synaptic Function” Center for Molecular Neurobiology ZMNH University Medical Center Hamburg‐Eppendorf Hamburg Germany
- Research Group Neuroplasticity Leibniz Institute for Neurobiology Magdeburg Germany
- Center for Behavioral Brain Sciences Otto von Guericke University Magdeburg Germany
- German Center for Neurodegenerative Diseases (DZNE) Magdeburg Germany
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Lysosomal ATP Transporter SLC17A9 Controls Cell Viability via Regulating Cathepsin D. Cells 2022; 11:cells11050887. [PMID: 35269509 PMCID: PMC8909234 DOI: 10.3390/cells11050887] [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: 08/28/2021] [Revised: 02/26/2022] [Accepted: 02/28/2022] [Indexed: 12/04/2022] Open
Abstract
SLC17A9 (solute carrier family 17 member 9) functions as an ATP transporter in lysosomes as well as other secretory vesicles. SLC17A9 inhibition or silence leads to cell death. However, the molecular mechanisms causing cell death are unclear. In this study, we report that cell death induced by SLC17A9 deficiency is rescued by the transcription factor EB (TFEB), a master gene for lysosomal protein expression, suggesting that SLC17A9 deficiency may be the main cause of lysosome dysfunction, subsequently leading to cell death. Interestingly, Cathepsin D, a lysosomal aspartic protease, is inhibited by SLC17A9 deficiency. Heterologous expression of Cathepsin D successfully rescues lysosomal dysfunction and cell death induced by SLC17A9 deficiency. On the other hand, the activity of Cathepsin B, a lysosomal cysteine protease, is not altered by SLC17A9 deficiency, and Cathepsin B overexpression does not rescue lysosomal dysfunction and cell death induced by SLC17A9 deficiency. Our data suggest that lysosomal ATP and SLC17A9 play critical roles in lysosomal function and cell viability by regulating Cathepsin D activity.
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45
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Udayar V, Chen Y, Sidransky E, Jagasia R. Lysosomal dysfunction in neurodegeneration: emerging concepts and methods. Trends Neurosci 2022; 45:184-199. [PMID: 35034773 PMCID: PMC8854344 DOI: 10.1016/j.tins.2021.12.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 11/23/2021] [Accepted: 12/12/2021] [Indexed: 02/06/2023]
Abstract
The understanding of lysosomes has come a long way since the initial discovery of their role in degrading cellular waste. The lysosome is now recognized as a highly dynamic organelle positioned at the crossroads of cell signaling, transcription, and metabolism. Underscoring its importance is the observation that, in addition to rare monogenic lysosomal storage disorders, genes regulating lysosomal function are implicated in common sporadic neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS). Developing therapies for these disorders is particularly challenging, largely due to gaps in knowledge of the underlying molecular and cellular processes. In this review, we discuss technological advances that have propelled deeper understanding of the lysosome in neurodegeneration, from elucidating the functions of lysosome-related disease risk variants at the level of the organelle, cell, and tissue, to the development of disease-specific biological models that recapitulate disease manifestations. Finally, we identify key questions to be addressed to successfully bridge the gap to the clinic.
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Affiliation(s)
- Vinod Udayar
- Roche Pharmaceutical Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Yu Chen
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ellen Sidransky
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Ravi Jagasia
- Roche Pharmaceutical Research and Early Development, Neuroscience and Rare Diseases Discovery & Translational Area, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
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Mishra S, Knupp A, Szabo MP, Williams CA, Kinoshita C, Hailey DW, Wang Y, Andersen OM, Young JE. The Alzheimer's gene SORL1 is a regulator of endosomal traffic and recycling in human neurons. Cell Mol Life Sci 2022; 79:162. [PMID: 35226190 PMCID: PMC8885486 DOI: 10.1007/s00018-022-04182-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 01/24/2022] [Accepted: 01/31/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND Loss of the Sortilin-related receptor 1 (SORL1) gene seems to act as a causal event for Alzheimer's disease (AD). Recent studies have established that loss of SORL1, as well as mutations in autosomal dominant AD genes APP and PSEN1/2, pathogenically converge by swelling early endosomes, AD's cytopathological hallmark. Acting together with the retromer trafficking complex, SORL1 has been shown to regulate the recycling of the amyloid precursor protein (APP) out of the endosome, contributing to endosomal swelling and to APP misprocessing. We hypothesized that SORL1 plays a broader role in neuronal endosomal recycling and used human induced pluripotent stem cell-derived neurons (hiPSC-Ns) to test this hypothesis. We examined endosomal recycling of three transmembrane proteins linked to AD pathophysiology: APP, the BDNF receptor Tropomyosin-related kinase B (TRKB), and the glutamate receptor subunit AMPA1 (GLUA1). METHODS We used isogenic hiPSCs engineered to have SORL1 depleted or to have enhanced SORL1 expression. We differentiated neurons from these cell lines and mapped the trafficking of APP, TRKB and GLUA1 within the endosomal network using confocal microscopy. We also performed cell surface recycling and lysosomal degradation assays to assess the functionality of the endosomal network in both SORL1-depleted and -overexpressing neurons. The functional impact of GLUA1 recycling was determined by measuring synaptic activity. Finally, we analyzed alterations in gene expression in SORL1-depleted neurons using RNA sequencing. RESULTS We find that as with APP, endosomal trafficking of GLUA1 and TRKB is impaired by loss of SORL1. We show that trafficking of all three cargoes to late endosomes and lysosomes is affected by manipulating SORL1 expression. We also show that depletion of SORL1 significantly impacts the endosomal recycling pathway for APP and GLUA1 at the level of the recycling endosome and trafficking to the cell surface. This has a functional effect on neuronal activity as shown by multi-electrode array (MEA). Conversely, increased SORL1 expression enhances endosomal recycling for APP and GLUA1. Our unbiased transcriptomic data further support SORL1's role in endosomal recycling. We observe altered expression networks that regulate cell surface trafficking and neurotrophic signaling in SORL1-depleted neurons. CONCLUSION Collectively, and together with other recent observations, these findings suggest that one role for SORL1 is to contribute to endosomal degradation and recycling pathways in neurons, a conclusion that has both pathogenic and therapeutic implications for Alzheimer's disease.
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Affiliation(s)
- Swati Mishra
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
| | - Allison Knupp
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
| | - Marcell P. Szabo
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
| | - Charles A. Williams
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
| | - Chizuru Kinoshita
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
| | - Dale W. Hailey
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
| | - Yuliang Wang
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA 98195 USA
| | - Olav M. Andersen
- Department of Biomedicine, Danish Research Institute of Translational Neuroscience (DANDRITE), Aarhus University, Aarhus, Denmark
| | - Jessica E. Young
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195 USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
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Roney JC, Cheng XT, Sheng ZH. Neuronal endolysosomal transport and lysosomal functionality in maintaining axonostasis. J Cell Biol 2022; 221:213000. [PMID: 35142819 PMCID: PMC8932522 DOI: 10.1083/jcb.202111077] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 02/08/2023] Open
Abstract
Lysosomes serve as degradation hubs for the turnover of endocytic and autophagic cargos, which is essential for neuron function and survival. Deficits in lysosome function result in progressive neurodegeneration in most lysosomal storage disorders and contribute to the pathogenesis of aging-related neurodegenerative diseases. Given their size and highly polarized morphology, neurons face exceptional challenges in maintaining cellular homeostasis in regions far removed from the cell body where mature lysosomes are enriched. Neurons therefore require coordinated bidirectional intracellular transport to sustain efficient clearance capacity in distal axonal regions. Emerging lines of evidence have started to uncover mechanisms and signaling pathways regulating endolysosome transport and maturation to maintain axonal homeostasis, or “axonostasis,” that is relevant to a range of neurologic disorders. In this review, we discuss recent advances in how axonal endolysosomal trafficking, distribution, and lysosomal functionality support neuronal health and become disrupted in several neurodegenerative diseases.
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Affiliation(s)
- Joseph C Roney
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Xiu-Tang Cheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
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48
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Sun J, Liu Y, Hao X, Lin W, Su W, Chiang E, Baudry M, Bi X. LAMTOR1 inhibition of TRPML1‐dependent lysosomal calcium release regulates dendritic lysosome trafficking and hippocampal neuronal function. EMBO J 2022; 41:e108119. [PMID: 35099830 PMCID: PMC8886530 DOI: 10.15252/embj.2021108119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 12/12/2021] [Accepted: 12/21/2021] [Indexed: 02/05/2023] Open
Abstract
Lysosomes function not only as degradatory compartments but also as dynamic intracellular calcium ion stores. The transient receptor potential mucolipin 1 (TRPML1) channel mediates lysosomal Ca2+ release, thereby participating in multiple cellular functions. The pentameric Ragulator complex, which plays a critical role in the activation of mTORC1, is also involved in lysosomal trafficking and is anchored to lysosomes through its LAMTOR1 subunit. Here, we report that the Ragulator restricts lysosomal trafficking in dendrites of hippocampal neurons via LAMTOR1‐mediated tonic inhibition of TRPML1 activity, independently of mTORC1. LAMTOR1 directly interacts with TRPML1 through its N‐terminal domain. Eliminating this inhibition in hippocampal neurons by LAMTOR1 deletion or by disrupting LAMTOR1‐TRPML1 binding increases TRPML1‐mediated Ca2+ release and facilitates dendritic lysosomal trafficking powered by dynein. LAMTOR1 deletion in the hippocampal CA1 region of adult mice results in alterations in synaptic plasticity, and in impaired object‐recognition memory and contextual fear conditioning, due to TRPML1 activation. Mechanistically, changes in synaptic plasticity are associated with increased GluA1 dephosphorylation by calcineurin and lysosomal degradation. Thus, LAMTOR1‐mediated inhibition of TRPML1 is critical for regulating dendritic lysosomal motility, synaptic plasticity, and learning.
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Affiliation(s)
- Jiandong Sun
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona CA USA
| | - Yan Liu
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Xiaoning Hao
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona CA USA
| | - Weiju Lin
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Wenyue Su
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Emerald Chiang
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona CA USA
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Nassal JP, Murphy FH, Toonen RF, Verhage M. Differential axonal trafficking of Neuropeptide Y-, LAMP1-, and RAB7-tagged organelles in vivo. eLife 2022; 11:81721. [PMID: 36459486 PMCID: PMC9718525 DOI: 10.7554/elife.81721] [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: 07/08/2022] [Accepted: 11/22/2022] [Indexed: 12/04/2022] Open
Abstract
Different organelles traveling through neurons exhibit distinct properties in vitro, but this has not been investigated in the intact mammalian brain. We established simultaneous dual color two-photon microscopy to visualize the trafficking of Neuropeptide Y (NPY)-, LAMP1-, and RAB7-tagged organelles in thalamocortical axons imaged in mouse cortex in vivo. This revealed that LAMP1- and RAB7-tagged organelles move significantly faster than NPY-tagged organelles in both anterograde and retrograde direction. NPY traveled more selectively in anterograde direction than LAMP1 and RAB7. By using a synapse marker and a calcium sensor, we further investigated the transport dynamics of NPY-tagged organelles. We found that these organelles slow down and pause at synapses. In contrast to previous in vitro studies, a significant increase of transport speed was observed after spontaneous activity and elevated calcium levels in vivo as well as electrically stimulated activity in acute brain slices. Together, we show a remarkable diversity in speeds and properties of three axonal organelle marker in vivo that differ from properties previously observed in vitro.
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Affiliation(s)
- Joris P Nassal
- Departments of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU University Medical CenterAmsterdamNetherlands
| | - Fiona H Murphy
- Departments of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU University Medical CenterAmsterdamNetherlands
| | - Ruud F Toonen
- Departments of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU University Medical CenterAmsterdamNetherlands
| | - Matthijs Verhage
- Departments of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research (CNCR), VU University Amsterdam and VU University Medical CenterAmsterdamNetherlands
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Wang T, Meunier FA. Live-Cell Superresolution Imaging of Retrograde Axonal Trafficking Using Pulse-Chase Labeling in Cultured Hippocampal Neurons. Methods Mol Biol 2022; 2473:101-128. [PMID: 35819762 DOI: 10.1007/978-1-0716-2209-4_9] [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] [Indexed: 06/15/2023]
Abstract
The entanglement of long axons found in cultured dissociated hippocampal neurons restricts the analysis of the machinery underlying directed axonal trafficking. Further, hippocampal neurons exhibit "en passant" presynapses that may confound the analysis of long-range retrograde axonal transport. To solve these issues, we and others have developed microfluid-based methods to specifically follow the fates of the retrograde axonal cargoes following pulse-chase labeling by super-resolution live-cell imaging, and automatically tracking their directed transport and analyzing their kinetical properties. These methods have allowed us to visualize the trafficking of fluorescently tagged signaling endosomes and autophagosomes derived from axonal terminals and resolve their localizations and movements with high spatial and temporal accuracy. In this chapter, we describe how to use a commercially available microfluidic device to enable the labeling and tracking of retrograde axonal carriers, including (1) how to culture and transfect rat hippocampal neurons in the microfluidic device; (2) how to perform pulse-chase to label specific populations of retrograde axonal carriers; and (3) how to conduct the automatic tracking and data analysis using open-source software.
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Affiliation(s)
- Tong Wang
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China.
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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