1
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Tu WY, Xu W, Bai L, Liu J, Han Y, Luo B, Wang B, Zhang K, Shen C. Local protein synthesis at neuromuscular synapses is required for motor functions. Cell Rep 2024; 43:114661. [PMID: 39178112 DOI: 10.1016/j.celrep.2024.114661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 06/27/2024] [Accepted: 08/05/2024] [Indexed: 08/25/2024] Open
Abstract
Motor neurons are highly polarized, and their axons extend over great distances to form connections with myofibers via neuromuscular junctions (NMJs). Local translation at the NMJs in vivo has not been identified. Here, we utilized motor neuron-labeled RiboTag mice and the TRAP (translating ribosome affinity purification) technique to spatiotemporally profile the translatome at NMJs. We found that mRNAs associated with glucose catabolism, synaptic connection, and protein homeostasis are enriched at presynapses. Local translation at the synapse shifts from the assembly of cytoskeletal components during early developmental stages to energy production in adulthood. The mRNA of neuronal Agrin (Agrn), the key molecule for NMJ assembly, is present at motor axon terminals and locally translated. Disrupting the axonal location of Agrn mRNA causes impairment of synaptic transmission and motor functions in adult mice. Our findings indicate that spatiotemporal regulation of mRNA local translation at NMJs plays critical roles in synaptic transmission and motor functions in vivo.
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Affiliation(s)
- Wen-Yo Tu
- Department of Neurobiology of First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Wentao Xu
- Department of Neurobiology of First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Lei Bai
- Department of Neurobiology of First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Jun Liu
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yi Han
- Department of Neurobiology of First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Benyan Luo
- Department of Neurobiology of First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310020, China
| | - Bingwei Wang
- School of Medicine & Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing, China
| | - Kejing Zhang
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, MOE Joint International Research Laboratory of Pancreatic Diseases, First Affiliated Hospital, Hangzhou 310006, China.
| | - Chengyong Shen
- Department of Neurobiology of First Affiliated Hospital, Zhejiang Key Laboratory of Frontier Medical Research on Cancer Metabolism, Institute of Translational Medicine, School of Medicine, Zhejiang University, Hangzhou 310020, China; MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University, Hangzhou 310058, China.
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2
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Koppers M, Özkan N, Nguyen HH, Jurriens D, McCaughey J, Nguyen DTM, Li CH, Stucchi R, Altelaar M, MacGillavry HD, Kapitein LC, Hoogenraad CC, Farías GG. Axonal endoplasmic reticulum tubules control local translation via P180/RRBP1-mediated ribosome interactions. Dev Cell 2024; 59:2053-2068.e9. [PMID: 38815583 PMCID: PMC11338522 DOI: 10.1016/j.devcel.2024.05.005] [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: 10/12/2022] [Revised: 01/31/2024] [Accepted: 05/09/2024] [Indexed: 06/01/2024]
Abstract
Local mRNA translation in axons is critical for the spatiotemporal regulation of the axonal proteome. A wide variety of mRNAs are localized and translated in axons; however, how protein synthesis is regulated at specific subcellular sites in axons remains unclear. Here, we establish that the axonal endoplasmic reticulum (ER) supports axonal translation in developing rat hippocampal cultured neurons. Axonal ER tubule disruption impairs local translation and ribosome distribution. Using nanoscale resolution imaging, we find that ribosomes make frequent contacts with axonal ER tubules in a translation-dependent manner and are influenced by specific extrinsic cues. We identify P180/RRBP1 as an axonally distributed ribosome receptor that regulates local translation and binds to mRNAs enriched for axonal membrane proteins. Importantly, the impairment of axonal ER-ribosome interactions causes defects in axon morphology. Our results establish a role for the axonal ER in dynamically localizing mRNA translation, which is important for proper neuron development.
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Affiliation(s)
- Max Koppers
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands.
| | - Nazmiye Özkan
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Ha H Nguyen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Daphne Jurriens
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Janine McCaughey
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Dan T M Nguyen
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Chun Hei Li
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Riccardo Stucchi
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands; Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Harold D MacGillavry
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Lukas C Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands; Department of Neuroscience, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Ginny G Farías
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, the Netherlands.
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3
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Liang Y, Li Y, Jiao Q, Wei M, Wang Y, Cui A, Li Z, Li G. Axonal mitophagy in retinal ganglion cells. Cell Commun Signal 2024; 22:382. [PMID: 39075570 PMCID: PMC11285280 DOI: 10.1186/s12964-024-01761-0] [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: 12/15/2023] [Accepted: 07/22/2024] [Indexed: 07/31/2024] Open
Abstract
Neurons, exhibiting unique polarized structures, rely primarily on the mitochondrial production of ATP to maintain their hypermetabolic energy requirements. To maintain a normal energy supply, mitochondria are transported to the distal end of the axon. When mitochondria within the axon are critically damaged beyond their compensatory capacity, they are cleared via autophagosomal phagocytosis, and the degradation products are recycled to replenish energy. When the mitochondria are dysfunctional or their transport processes are blocked, axons become susceptible to degeneration triggered by energy depletion, resulting in neurodegenerative diseases. As the final checkpoint for mitochondrial quality control, axonal mitophagy is vital for neuronal growth, development, injury, and regeneration. Furthermore, abnormal axonal mitophagy is crucial in the pathogenesis of optic nerve-related diseases such as glaucoma. We review recent studies on axonal mitophagy and summarize the progress of research on axonal mitophagy in optic nerve-related diseases to provide insights into diseases associated with axonal damage in optic ganglion cells.
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Affiliation(s)
- Yang Liang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Yulin Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Qing Jiao
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Muyang Wei
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Yan Wang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Aoteng Cui
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Zhihui Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Guangyu Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
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4
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Lu WH, Chang TT, Chang YM, Liu YH, Lin CH, Suen CS, Hwang MJ, Huang YS. CPEB2-activated axonal translation of VGLUT2 mRNA promotes glutamatergic transmission and presynaptic plasticity. J Biomed Sci 2024; 31:69. [PMID: 38992696 PMCID: PMC11241979 DOI: 10.1186/s12929-024-01061-2] [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: 11/13/2023] [Accepted: 07/02/2024] [Indexed: 07/13/2024] Open
Abstract
BACKGROUND Local translation at synapses is important for rapidly remodeling the synaptic proteome to sustain long-term plasticity and memory. While the regulatory mechanisms underlying memory-associated local translation have been widely elucidated in the postsynaptic/dendritic region, there is no direct evidence for which RNA-binding protein (RBP) in axons controls target-specific mRNA translation to promote long-term potentiation (LTP) and memory. We previously reported that translation controlled by cytoplasmic polyadenylation element binding protein 2 (CPEB2) is important for postsynaptic plasticity and memory. Here, we investigated whether CPEB2 regulates axonal translation to support presynaptic plasticity. METHODS Behavioral and electrophysiological assessments were conducted in mice with pan neuron/glia- or glutamatergic neuron-specific knockout of CPEB2. Hippocampal Schaffer collateral (SC)-CA1 and temporoammonic (TA)-CA1 pathways were electro-recorded to monitor synaptic transmission and LTP evoked by 4 trains of high-frequency stimulation. RNA immunoprecipitation, coupled with bioinformatics analysis, were used to unveil CPEB2-binding axonal RNA candidates associated with learning, which were further validated by Western blotting and luciferase reporter assays. Adeno-associated viruses expressing Cre recombinase were stereotaxically delivered to the pre- or post-synaptic region of the TA circuit to ablate Cpeb2 for further electrophysiological investigation. Biochemically isolated synaptosomes and axotomized neurons cultured on a microfluidic platform were applied to measure axonal protein synthesis and FM4-64FX-loaded synaptic vesicles. RESULTS Electrophysiological analysis of hippocampal CA1 neurons detected abnormal excitability and vesicle release probability in CPEB2-depleted SC and TA afferents, so we cross-compared the CPEB2-immunoprecipitated transcriptome with a learning-induced axonal translatome in the adult cortex to identify axonal targets possibly regulated by CPEB2. We validated that Slc17a6, encoding vesicular glutamate transporter 2 (VGLUT2), is translationally upregulated by CPEB2. Conditional knockout of CPEB2 in VGLUT2-expressing glutamatergic neurons impaired consolidation of hippocampus-dependent memory in mice. Presynaptic-specific ablation of Cpeb2 in VGLUT2-dominated TA afferents was sufficient to attenuate protein synthesis-dependent LTP. Moreover, blocking activity-induced axonal Slc17a6 translation by CPEB2 deficiency or cycloheximide diminished the releasable pool of VGLUT2-containing synaptic vesicles. CONCLUSIONS We identified 272 CPEB2-binding transcripts with altered axonal translation post-learning and established a causal link between CPEB2-driven axonal synthesis of VGLUT2 and presynaptic translation-dependent LTP. These findings extend our understanding of memory-related translational control mechanisms in the presynaptic compartment.
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Affiliation(s)
- Wen-Hsin Lu
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
| | - Tzu-Tung Chang
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
| | - Yao-Ming Chang
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
| | - Yi-Hsiang Liu
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
| | - Chia-Hsuan Lin
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang-Ming Chao-Tung University and Academia Sinica, Taipei, 11529, Taiwan
| | - Ching-Shu Suen
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
| | - Ming-Jing Hwang
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan
| | - Yi-Shuian Huang
- Institute of Biomedical Sciences, Academia Sinica, 128 Sec. 2, Academia Rd., Taipei, 11529, Taiwan.
- Taiwan International Graduate Program in Interdisciplinary Neuroscience, National Yang-Ming Chao-Tung University and Academia Sinica, Taipei, 11529, Taiwan.
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei, 11529, Taiwan.
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5
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Clayton EL, Huggon L, Cousin MA, Mizielinska S. Synaptopathy: presynaptic convergence in frontotemporal dementia and amyotrophic lateral sclerosis. Brain 2024; 147:2289-2307. [PMID: 38451707 PMCID: PMC11224618 DOI: 10.1093/brain/awae074] [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: 08/18/2023] [Revised: 02/02/2024] [Accepted: 02/12/2024] [Indexed: 03/09/2024] Open
Abstract
Frontotemporal dementia and amyotrophic lateral sclerosis are common forms of neurodegenerative disease that share overlapping genetics and pathologies. Crucially, no significantly disease-modifying treatments are available for either disease. Identifying the earliest changes that initiate neuronal dysfunction is important for designing effective intervention therapeutics. The genes mutated in genetic forms of frontotemporal dementia and amyotrophic lateral sclerosis have diverse cellular functions, and multiple disease mechanisms have been proposed for both. Identification of a convergent disease mechanism in frontotemporal dementia and amyotrophic lateral sclerosis would focus research for a targetable pathway, which could potentially effectively treat all forms of frontotemporal dementia and amyotrophic lateral sclerosis (both familial and sporadic). Synaptopathies are diseases resulting from physiological dysfunction of synapses, and define the earliest stages in multiple neuronal diseases, with synapse loss a key feature in dementia. At the presynapse, the process of synaptic vesicle recruitment, fusion and recycling is necessary for activity-dependent neurotransmitter release. The unique distal location of the presynaptic terminal means the tight spatio-temporal control of presynaptic homeostasis is dependent on efficient local protein translation and degradation. Recently, numerous publications have shown that mutations associated with frontotemporal dementia and amyotrophic lateral sclerosis present with synaptopathy characterized by presynaptic dysfunction. This review will describe the complex local signalling and membrane trafficking events that occur at the presynapse to facilitate neurotransmission and will summarize recent publications linking frontotemporal dementia/amyotrophic lateral sclerosis genetic mutations to presynaptic function. This evidence indicates that presynaptic synaptopathy is an early and convergent event in frontotemporal dementia and amyotrophic lateral sclerosis and illustrates the need for further research in this area, to identify potential therapeutic targets with the ability to impact this convergent pathomechanism.
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Affiliation(s)
- Emma L Clayton
- UK Dementia Research Institute at King’s College London, London SE5 9RT, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RT, UK
| | - Laura Huggon
- UK Dementia Research Institute at King’s College London, London SE5 9RT, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RT, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
- Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh EH8 9XD, UK
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sarah Mizielinska
- UK Dementia Research Institute at King’s College London, London SE5 9RT, UK
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, Maurice Wohl Clinical Neuroscience Institute, London SE5 9RT, UK
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6
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Chekulaeva M. Mechanistic insights into the basis of widespread RNA localization. Nat Cell Biol 2024; 26:1037-1046. [PMID: 38956277 DOI: 10.1038/s41556-024-01444-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 05/20/2024] [Indexed: 07/04/2024]
Abstract
The importance of subcellular mRNA localization is well established, but the underlying mechanisms mostly remain an enigma. Early studies suggested that specific mRNA sequences recruit RNA-binding proteins (RBPs) to regulate mRNA localization. However, despite the observation of thousands of localized mRNAs, only a handful of these sequences and RBPs have been identified. This suggests the existence of alternative, and possibly predominant, mechanisms for mRNA localization. Here I re-examine currently described mRNA localization mechanisms and explore alternative models that could account for its widespread occurrence.
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Affiliation(s)
- Marina Chekulaeva
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin, Germany.
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7
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Loreto A, Merlini E, Coleman MP. Programmed axon death: a promising target for treating retinal and optic nerve disorders. Eye (Lond) 2024; 38:1802-1809. [PMID: 38538779 PMCID: PMC11226669 DOI: 10.1038/s41433-024-03025-0] [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: 09/04/2023] [Revised: 02/13/2024] [Accepted: 03/08/2024] [Indexed: 07/07/2024] Open
Abstract
Programmed axon death is a druggable pathway of axon degeneration that has garnered considerable interest from pharmaceutical companies as a promising therapeutic target for various neurodegenerative disorders. In this review, we highlight mechanisms through which this pathway is activated in the retina and optic nerve, and discuss its potential significance for developing therapies for eye disorders and beyond. At the core of programmed axon death are two enzymes, NMNAT2 and SARM1, with pivotal roles in NAD metabolism. Extensive preclinical data in disease models consistently demonstrate remarkable, and in some instances, complete and enduring neuroprotection when this mechanism is targeted. Findings from animal studies are now being substantiated by genetic human data, propelling the field rapidly toward clinical translation. As we approach the clinical phase, the selection of suitable disorders for initial clinical trials targeting programmed axon death becomes crucial for their success. We delve into the multifaceted roles of programmed axon death and NAD metabolism in retinal and optic nerve disorders. We discuss the role of SARM1 beyond axon degeneration, including its potential involvement in neuronal soma death and photoreceptor degeneration. We also discuss genetic human data and environmental triggers of programmed axon death. Lastly, we touch upon potential therapeutic approaches targeting NMNATs and SARM1, as well as the nicotinamide trials for glaucoma. The extensive literature linking programmed axon death to eye disorders, along with the eye's suitability for drug delivery and visual assessments, makes retinal and optic nerve disorders strong contenders for early clinical trials targeting programmed axon death.
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Affiliation(s)
- Andrea Loreto
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK.
- School of Medical Sciences and Save Sight Institute, Charles Perkins Centre, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.
| | - Elisa Merlini
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK
| | - Michael P Coleman
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK.
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8
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Abstract
The translation of messenger RNA (mRNA) into proteins represents the culmination of gene expression. Recent technological advances have revolutionized our ability to investigate this process with unprecedented precision, enabling the study of translation at the single-molecule level in real time within live cells. In this review, we provide an overview of single-mRNA translation reporters. We focus on the core technology, as well as the rapid development of complementary probes, tags, and accessories that enable the visualization and quantification of a wide array of translation dynamics. We then highlight notable studies that have utilized these reporters in model systems to address key biological questions. The high spatiotemporal resolution of these studies is shedding light on previously unseen phenomena, uncovering the full heterogeneity and complexity of translational regulation.
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Affiliation(s)
- Tatsuya Morisaki
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
| | - O'Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
| | - Timothy J Stasevich
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, USA;
- Cell Biology Center and World Research Hub Initiative, Tokyo Institute of Technology, Yokohama, Japan
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9
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Martin-Solana E, Carter SD, Donahue EKF, Ning J, Glausier JR, Preisegger MA, Eisenman L, Joseph PN, Bouchet-Marquis C, Wu K, Mobini CL, Frantz AN, Puig S, Hampton CM, Kabbani N, Jensen GJ, Watkins SC, Deisseroth K, Fenno LE, Gold MS, Wills ZP, Burkewitz K, Das S, Freyberg Z. Ribosome-Associated Vesicles promote activity-dependent local translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.598007. [PMID: 38895376 PMCID: PMC11185778 DOI: 10.1101/2024.06.07.598007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Local protein synthesis in axons and dendrites underpins synaptic plasticity. However, the composition of the protein synthesis machinery in distal neuronal processes and the mechanisms for its activity-driven deployment to local translation sites remain unclear. Here, we employed cryo-electron tomography, volume electron microscopy, and live-cell imaging to identify Ribosome-Associated Vesicles (RAVs) as a dynamic platform for moving ribosomes to distal processes. Stimulation via chemically-induced long-term potentiation causes RAV accumulation in distal sites to drive local translation. We also demonstrate activity-driven changes in RAV generation and dynamics in vivo, identifying tubular ER shaping proteins in RAV biogenesis. Together, our work identifies a mechanism for ribosomal delivery to distal sites in neurons to promote activity-dependent local translation.
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Affiliation(s)
- Eva Martin-Solana
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen D Carter
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, UK
| | - Eric K F Donahue
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Jiying Ning
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jill R Glausier
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Leanna Eisenman
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Paul N Joseph
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Ken Wu
- Materials and Structural Analysis, Thermo Fisher Scientific, Hillsboro, OR, USA
| | | | - Amber N Frantz
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephanie Puig
- Department of Psychiatry, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Cheri M Hampton
- UES, Inc., Dayton, OH, USA
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, OH, USA
| | - Nadine Kabbani
- Interdisciplinary Program in Neuroscience, George Mason University, Fairfax, VA, USA
- School of Systems Biology, George Mason University, Fairfax, VA, USA
| | - Grant J Jensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, USA
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - Lief E Fenno
- Departments of Psychiatry and Neuroscience, University of Texas Austin Dell Medical School, Austin, TX, USA
| | - Michael S Gold
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zachary P Wills
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kristopher Burkewitz
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Sulagna Das
- Department of Cell Biology, Albert Einstein College of Medicine, NY
- Department of Cell Biology, Emory University, Atlanta, GA, USA
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Zachary Freyberg
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
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10
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Sahoo PK, Hanovice N, Ward P, Agrawal M, Smith TP, SiMa H, Dulin JN, Vaughn LS, Tuszynski M, Welshhans K, Benowitz L, English A, Houle JD, Twiss JL. Disruption of Core Stress Granule Protein Aggregates Promotes CNS Axon Regeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597743. [PMID: 38895344 PMCID: PMC11185597 DOI: 10.1101/2024.06.07.597743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Depletion or inhibition of core stress granule proteins, G3BP1 in mammals and TIAR-2 in C. elegans , increases axon regeneration in injured neurons that show spontaneous regeneration. Inhibition of G3BP1 by expression of its acidic or 'B-domain' accelerates axon regeneration after nerve injury bringing a potential therapeutic intervention to promote neural repair in the peripheral nervous system. Here, we asked if G3BP1 inhibition is a viable strategy to promote regeneration in the injured mammalian central nervous system where axons do not regenerate spontaneously. G3BP1 B-domain expression was found to promote axon regeneration in both the mammalian spinal cord and optic nerve. Moreover, a cell permeable peptide to a subregion of G3BP1's B-domain (rodent G3BP1 amino acids 190-208) accelerated axon regeneration after peripheral nerve injury and promoted the regrowth of reticulospinal axons into the distal transected spinal cord through a bridging peripheral nerve graft. The rodent and human G3BP1 peptides promoted axon growth from rodent and human neurons cultured on permissive substrates, and this function required alternating Glu/Asp-Pro repeats that impart a unique predicted tertiary structure. These studies point to G3BP1 granules as a critical impediment to CNS axon regeneration and indicate that G3BP1 granule disassembly represents a novel therapeutic strategy for promoting neural repair after CNS injury.
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11
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Prince GS, Reynolds M, Martina V, Sun H. Gene-environmental regulation of the postnatal post-mitotic neuronal maturation. Trends Genet 2024; 40:480-494. [PMID: 38658255 PMCID: PMC11153025 DOI: 10.1016/j.tig.2024.03.006] [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: 01/30/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
Embryonic neurodevelopment, particularly neural progenitor differentiation into post-mitotic neurons, has been extensively studied. While the number and composition of post-mitotic neurons remain relatively constant from birth to adulthood, the brain undergoes significant postnatal maturation marked by major property changes frequently disrupted in neural diseases. This review first summarizes recent characterizations of the functional and molecular maturation of the postnatal nervous system. We then review regulatory mechanisms controlling the precise gene expression changes crucial for the intricate sequence of maturation events, highlighting experience-dependent versus cell-intrinsic genetic timer mechanisms. Despite significant advances in understanding of the gene-environmental regulation of postnatal neuronal maturation, many aspects remain unknown. The review concludes with our perspective on exciting future research directions in the next decade.
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Affiliation(s)
- Gabrielle S Prince
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Molly Reynolds
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Verdion Martina
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - HaoSheng Sun
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA; Freeman Hrabowski Scholar, Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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12
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Bjorklund GR, Rees KP, Balasubramanian K, Hewitt LT, Nishimura K, Newbern JM. Hyperactivation of MEK1 in cortical glutamatergic neurons results in projection axon deficits and aberrant motor learning. Dis Model Mech 2024; 17:dmm050570. [PMID: 38826084 PMCID: PMC11247507 DOI: 10.1242/dmm.050570] [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: 11/06/2023] [Accepted: 05/21/2024] [Indexed: 06/04/2024] Open
Abstract
Abnormal extracellular signal-regulated kinase 1/2 (ERK1/2, encoded by Mapk3 and Mapk1, respectively) signaling is linked to multiple neurodevelopmental diseases, especially the RASopathies, which typically exhibit ERK1/2 hyperactivation in neurons and non-neuronal cells. To better understand how excitatory neuron-autonomous ERK1/2 activity regulates forebrain development, we conditionally expressed a hyperactive MEK1 (MAP2K1) mutant, MEK1S217/221E, in cortical excitatory neurons of mice. MEK1S217/221E expression led to persistent hyperactivation of ERK1/2 in cortical axons, but not in soma/nuclei. We noted reduced axonal arborization in multiple target domains in mutant mice and reduced the levels of the activity-dependent protein ARC. These changes did not lead to deficits in voluntary locomotion or accelerating rotarod performance. However, skilled motor learning in a single-pellet retrieval task was significantly diminished in these MEK1S217/221E mutants. Restriction of MEK1S217/221E expression to layer V cortical neurons recapitulated axonal outgrowth deficits but did not affect motor learning. These results suggest that cortical excitatory neuron-autonomous hyperactivation of MEK1 is sufficient to drive deficits in axon outgrowth, which coincide with reduced ARC expression, and deficits in skilled motor learning. Our data indicate that neuron-autonomous decreases in long-range axonal outgrowth may be a key aspect of neuropathogenesis in RASopathies.
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Affiliation(s)
- George R. Bjorklund
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, USA
| | - Katherina P. Rees
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | | | - Lauren T. Hewitt
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Kenji Nishimura
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Jason M. Newbern
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
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13
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Hacisuleyman E, Hale CR, Noble N, Luo JD, Fak JJ, Saito M, Chen J, Weissman JS, Darnell RB. Neuronal activity rapidly reprograms dendritic translation via eIF4G2:uORF binding. Nat Neurosci 2024; 27:822-835. [PMID: 38589584 PMCID: PMC11088998 DOI: 10.1038/s41593-024-01615-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 03/05/2024] [Indexed: 04/10/2024]
Abstract
Learning and memory require activity-induced changes in dendritic translation, but which mRNAs are involved and how they are regulated are unclear. In this study, to monitor how depolarization impacts local dendritic biology, we employed a dendritically targeted proximity labeling approach followed by crosslinking immunoprecipitation, ribosome profiling and mass spectrometry. Depolarization of primary cortical neurons with KCl or the glutamate agonist DHPG caused rapid reprogramming of dendritic protein expression, where changes in dendritic mRNAs and proteins are weakly correlated. For a subset of pre-localized messages, depolarization increased the translation of upstream open reading frames (uORFs) and their downstream coding sequences, enabling localized production of proteins involved in long-term potentiation, cell signaling and energy metabolism. This activity-dependent translation was accompanied by the phosphorylation and recruitment of the non-canonical translation initiation factor eIF4G2, and the translated uORFs were sufficient to confer depolarization-induced, eIF4G2-dependent translational control. These studies uncovered an unanticipated mechanism by which activity-dependent uORF translational control by eIF4G2 couples activity to local dendritic remodeling.
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Affiliation(s)
- Ezgi Hacisuleyman
- Laboratory of Molecular Neuro-oncology, The Rockefeller University, New York, NY, USA.
| | - Caryn R Hale
- Laboratory of Molecular Neuro-oncology, The Rockefeller University, New York, NY, USA
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Natalie Noble
- Laboratory of Molecular Neuro-oncology, The Rockefeller University, New York, NY, USA
| | - Ji-Dung Luo
- Bioinformatics Resource Center, The Rockefeller University, New York, NY, USA
| | - John J Fak
- Laboratory of Molecular Neuro-oncology, The Rockefeller University, New York, NY, USA
| | - Misa Saito
- Laboratory of Molecular Neuro-oncology, The Rockefeller University, New York, NY, USA
| | - Jin Chen
- Department of Pharmacology and Cecil H. and Ida Green Center for Reproductive Biology Sciences, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Altos Labs, Bay Area Institute of Science, Redwood City, CA, USA
| | - Jonathan S Weissman
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA.
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Robert B Darnell
- Laboratory of Molecular Neuro-oncology, The Rockefeller University, New York, NY, USA.
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA.
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14
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Clifton NE, Lin JQ, Holt CE, O'Donovan MC, Mill J. Enrichment of the Local Synaptic Translatome for Genetic Risk Associated With Schizophrenia and Autism Spectrum Disorder. Biol Psychiatry 2024; 95:888-895. [PMID: 38103876 DOI: 10.1016/j.biopsych.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/15/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND Genes that encode synaptic proteins or messenger RNA targets of the RNA-binding protein FMRP (fragile X messenger ribonucleoprotein) have been linked to schizophrenia and autism spectrum disorder (ASD) through the enrichment of genetic variants that confer risk for these disorders. FMRP binds many transcripts with synaptic functions and is thought to regulate their local translation, a process that enables rapid and compartmentalized protein synthesis required for development and plasticity. METHODS We used summary statistics from large-scale genome-wide association studies of schizophrenia (74,776 cases, 101,023 controls) and ASD (18,381 cases, 27,969 controls) to test the hypothesis that the subset of synaptic genes that encode localized transcripts is more strongly associated with each disorder than nonlocalized transcripts. We also postulated that this subset of synaptic genes is responsible for associations attributed to FMRP targets. RESULTS Schizophrenia associations were enriched in genes encoding localized synaptic transcripts compared to the remaining synaptic genes or to the remaining localized transcripts; this also applied to ASD associations, although only for transcripts observed after stimulation by fear conditioning. The genetic associations with either disorder captured by these gene sets were independent of those derived from FMRP targets. Schizophrenia association was related to FMRP interactions with messenger RNAs in somata, but not in dendrites, while ASD association was related to FMRP binding in either compartment. CONCLUSIONS Our data suggest that synaptic transcripts capable of local translation are particularly relevant to the pathogenesis of schizophrenia and ASD, but they do not characterize the associations attributed to current sets of FMRP targets.
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Affiliation(s)
- Nicholas E Clifton
- Department of Clinical & Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom.
| | - Julie Qiaojin Lin
- UK Dementia Research Institute, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom; UK Dementia Research Institute, King's College London, London, United Kingdom
| | - Christine E Holt
- Department of Physiology Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Michael C O'Donovan
- Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, United Kingdom
| | - Jonathan Mill
- Department of Clinical & Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
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15
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Ransom LS, Liu CS, Dunsmore E, Palmer CR, Nicodemus J, Ziomek D, Williams N, Chun J. Human brain small extracellular vesicles contain selectively packaged, full-length mRNA. Cell Rep 2024; 43:114061. [PMID: 38578831 DOI: 10.1016/j.celrep.2024.114061] [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: 10/05/2023] [Revised: 02/12/2024] [Accepted: 03/20/2024] [Indexed: 04/07/2024] Open
Abstract
Brain cells release and take up small extracellular vesicles (sEVs) containing bioactive nucleic acids. sEV exchange is hypothesized to contribute to stereotyped spread of neuropathological changes in the diseased brain. We assess mRNA from sEVs of postmortem brain from non-diseased (ND) individuals and those with Alzheimer's disease (AD) using short- and long-read sequencing. sEV transcriptomes are distinct from those of bulk tissue, showing enrichment for genes including mRNAs encoding ribosomal proteins and transposable elements such as human-specific LINE-1 (L1Hs). AD versus ND sEVs show enrichment of inflammation-related mRNAs and depletion of synaptic signaling mRNAs. sEV mRNAs from cultured murine primary neurons, astrocytes, or microglia show similarities to human brain sEVs and reveal cell-type-specific packaging. Approximately 80% of neural sEV transcripts sequenced using long-read sequencing are full length. Motif analyses of sEV-enriched isoforms elucidate RNA-binding proteins that may be associated with sEV loading. Collectively, we show that mRNA in brain sEVs is intact, selectively packaged, and altered in disease.
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Affiliation(s)
- Linnea S Ransom
- Biomedical Sciences Graduate Program, School of Medicine, University of California, San Diego, La Jolla, CA, USA; Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Christine S Liu
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Emily Dunsmore
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Carter R Palmer
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Juliet Nicodemus
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Derya Ziomek
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Nyssa Williams
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Jerold Chun
- Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA.
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16
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Cardanho-Ramos C, Simões RA, Wang YZ, Faria-Pereira A, Bomba-Warczak E, Craessaerts K, Spinazzi M, Savas JN, Morais VA. Local mitochondrial replication in the periphery of neurons requires the eEF1A1 protein and thetranslation of nuclear-encoded proteins. iScience 2024; 27:109136. [PMID: 38510136 PMCID: PMC10951640 DOI: 10.1016/j.isci.2024.109136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 12/19/2023] [Accepted: 02/01/2024] [Indexed: 03/22/2024] Open
Abstract
In neurons, it is commonly assumed that mitochondrial replication only occurs in the cell body, after which the mitochondria must travel to the neuron's periphery. However, while mitochondrial DNA replication has been observed to occur away from the cell body, the specific mechanisms involved remain elusive. Using EdU-labelling in mouse primary neurons, we developed a tool to determine the mitochondrial replication rate. Taking of advantage of microfluidic devices, we confirmed that mitochondrial replication also occurs locally in the periphery of neurons. To achieve this, mitochondria require de novo nuclear-encoded, but not mitochondrial-encoded protein translation. Following a proteomic screen comparing synaptic with non-synaptic mitochondria, we identified two elongation factors - eEF1A1 and TUFM - that were upregulated in synaptic mitochondria. We found that mitochondrial replication is impaired upon the downregulation of eEF1A1, and this is particularly relevant in the periphery of neurons.
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Affiliation(s)
- Carlos Cardanho-Ramos
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Rúben Alves Simões
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Yi-Zhi Wang
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Andreia Faria-Pereira
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Ewa Bomba-Warczak
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Katleen Craessaerts
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium
- Dementia Research Institute, University College London, London, UK
| | - Marco Spinazzi
- VIB Center for Brain and Disease Research and KU Leuven, Department of Neurosciences, Leuven, Belgium
- Dementia Research Institute, University College London, London, UK
- Neuromuscular Reference Center, Department of Neurology, Centre Hospitalier Universitaire d'Angers, Angers, France
| | - Jeffrey N. Savas
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Vanessa A. Morais
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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17
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Sun C. Single-Molecule-Resolution Approaches in Synaptic Biology. J Phys Chem B 2024; 128:3061-3068. [PMID: 38513216 DOI: 10.1021/acs.jpcb.3c08026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
Synapses between neurons are the primary loci for information transfer and storage in the brain. An individual neuron, alone, can make over 10000 synaptic contacts. It is, however, not easy to investigate what goes on locally within a synapse because many synaptic compartments are only a few hundred nanometers wide in size─close to the diffraction limit of light. To observe the biomolecular machinery and processes within synapses, in situ single-molecule techniques are emerging as powerful tools. Guided by important biological questions, this Perspective will highlight recent advances in using these techniques to obtain in situ measurements of synaptic molecules in three aspects: the cell-biological machinery within synapses, the synaptic architecture, and the synaptic neurotransmitter receptors. These advances showcase the increasing importance of single-molecule-resolution techniques for accessing subcellular biophysical and biomolecular information related to the brain.
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Affiliation(s)
- Chao Sun
- Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen 81, 8000 Aarhus C, Denmark
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18
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Avila-Gutierrez K, Slaoui L, Alvear-Perez R, Kozlowski E, Oudart M, Augustin E, Claveau C, Mailly P, Monnet H, Mignon V, Saubaméa B, Boulay AC, Cohen-Salmon M. Dynamic local mRNA localization and translation occurs during the postnatal molecular maturation of perivascular astrocytic processes. Glia 2024; 72:777-793. [PMID: 38189217 DOI: 10.1002/glia.24503] [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: 08/01/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/09/2024]
Abstract
Astrocytes are highly ramified and send out perivascular processes (PvAPs) that entirely sheathe the brain's blood vessels. PvAPs are equipped with an enriched molecular repertoire that sustains astrocytic regulatory functions at the vascular interface. In the mouse, PvAP development starts after birth and is essentially complete by postnatal day (P) 15. Progressive molecular maturation also occurs over this period, with the acquisition of proteins enriched in PvAPs. The mechanisms controlling the development and molecular maturation of PvAPs have not been extensively characterized. We reported previously that mRNAs are distributed unequally in mature PvAPs and are locally translated. Since dynamic mRNA localization and local translation influence the cell's polarity, we hypothesized that they might sustain the postnatal maturation of PvAPs. Here, we used a combination of molecular biology and imaging approaches to demonstrate that the development of PvAPs is accompanied by the transport of mRNA and polysomal mRNA into PvAPs, the development of a rough endoplasmic reticulum (RER) network and Golgi cisternae, and local translation. By focusing on genes and proteins that are selectively or specifically expressed in astrocytes, we characterized the developmental profile of mRNAs, polysomal mRNAs and proteins in PvAPs from P5 to P60. We found that some polysomal mRNAs polarized progressively towards the PvAPs. Lastly, we found that expression and localization of mRNAs in developing PvAPs is perturbed in a mouse model of megalencephalic leukoencephalopathy with subcortical cysts. Our results indicate that dynamic mRNA localization and local translation influence the postnatal maturation of PvAPs.
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Affiliation(s)
- Katia Avila-Gutierrez
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Leila Slaoui
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Rodrigo Alvear-Perez
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Esther Kozlowski
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Marc Oudart
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Emma Augustin
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Camille Claveau
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Philippe Mailly
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Héloïse Monnet
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Virginie Mignon
- INSERM, CNRS, P-MIM, Plateforme d'Imagerie Cellulaire et Moléculaire (PICMO), Université Paris Cité, Paris, France
| | - Bruno Saubaméa
- INSERM, CNRS, P-MIM, Plateforme d'Imagerie Cellulaire et Moléculaire (PICMO), Université Paris Cité, Paris, France
- Inserm, Optimisation Thérapeutique en Neuropsychopharmacologie, Université Paris Cité, Paris, France
| | - Anne-Cécile Boulay
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
| | - Martine Cohen-Salmon
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, Université PSL, Paris, France
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19
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Kilfeather P, Khoo JH, Wagner K, Liang H, Caiazza MC, An Y, Zhang X, Chen X, Connor-Robson N, Shang Z, Wade-Martins R. Single-cell spatial transcriptomic and translatomic profiling of dopaminergic neurons in health, aging, and disease. Cell Rep 2024; 43:113784. [PMID: 38386560 DOI: 10.1016/j.celrep.2024.113784] [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: 04/12/2023] [Revised: 11/14/2023] [Accepted: 01/27/2024] [Indexed: 02/24/2024] Open
Abstract
The brain is spatially organized and contains unique cell types, each performing diverse functions and exhibiting differential susceptibility to neurodegeneration. This is exemplified in Parkinson's disease with the preferential loss of dopaminergic neurons of the substantia nigra pars compacta. Using a Parkinson's transgenic model, we conducted a single-cell spatial transcriptomic and dopaminergic neuron translatomic analysis of young and old mouse brains. Through the high resolving capacity of single-cell spatial transcriptomics, we provide a deep characterization of the expression features of dopaminergic neurons and 27 other cell types within their spatial context, identifying markers of healthy and aging cells, spanning Parkinson's relevant pathways. We integrate gene enrichment and genome-wide association study data to prioritize putative causative genes for disease investigation, identifying CASR as a regulator of dopaminergic calcium handling. These datasets represent the largest public resource for the investigation of spatial gene expression in brain cells in health, aging, and disease.
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Affiliation(s)
- Peter Kilfeather
- Oxford Parkinson's Disease Centre and Department of Physiology, Anatomy and Genetics, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | | | - Katherina Wagner
- Oxford Parkinson's Disease Centre and Department of Physiology, Anatomy and Genetics, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | | | - Maria Claudia Caiazza
- Oxford Parkinson's Disease Centre and Department of Physiology, Anatomy and Genetics, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
| | - Yanru An
- BGI Research, 49276 Riga, Latvia
| | | | | | - Natalie Connor-Robson
- Oxford Parkinson's Disease Centre and Department of Physiology, Anatomy and Genetics, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK
| | | | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre and Department of Physiology, Anatomy and Genetics, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, UK; Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, USA.
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20
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Schieweck R, Götz M. Pan-cellular organelles and suborganelles-from common functions to cellular diversity? Genes Dev 2024; 38:98-114. [PMID: 38485267 PMCID: PMC10982711 DOI: 10.1101/gad.351337.123] [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] [Indexed: 04/02/2024]
Abstract
Cell diversification is at the base of increasing multicellular organism complexity in phylogeny achieved during ontogeny. However, there are also functions common to all cells, such as cell division, cell migration, translation, endocytosis, exocytosis, etc. Here we revisit the organelles involved in such common functions, reviewing recent evidence of unexpected differences of proteins at these organelles. For instance, centrosomes or mitochondria differ significantly in their protein composition in different, sometimes closely related, cell types. This has relevance for development and disease. Particularly striking is the high amount and diversity of RNA-binding proteins at these and other organelles, which brings us to review the evidence for RNA at different organelles and suborganelles. We include a discussion about (sub)organelles involved in translation, such as the nucleolus and ribosomes, for which unexpected cell type-specific diversity has also been reported. We propose here that the heterogeneity of these organelles and compartments represents a novel mechanism for regulating cell diversity. One reason is that protein functions can be multiplied by their different contributions in distinct organelles, as also exemplified by proteins with moonlighting function. The specialized organelles still perform pan-cellular functions but in a cell type-specific mode, as discussed here for centrosomes, mitochondria, vesicles, and other organelles. These can serve as regulatory hubs for the storage and transport of specific and functionally important regulators. In this way, they can control cell differentiation, plasticity, and survival. We further include examples highlighting the relevance for disease and propose to examine organelles in many more cell types for their possible differences with functional relevance.
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Affiliation(s)
- Rico Schieweck
- Institute of Biophysics, National Research Council (CNR) Unit at Trento, 38123 Povo, Italy;
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Magdalena Götz
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany;
- Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health, 82152 Planegg-Martinsried, Germany
- SYNERGY, Excellence Cluster of Systems Neurology, Biomedical Center, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
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21
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Oliveira MM, Mohamed M, Elder MK, Banegas-Morales K, Mamcarz M, Lu EH, Golhan EAN, Navrange N, Chatterjee S, Abel T, Klann E. The integrated stress response effector GADD34 is repurposed by neurons to promote stimulus-induced translation. Cell Rep 2024; 43:113670. [PMID: 38219147 PMCID: PMC10964249 DOI: 10.1016/j.celrep.2023.113670] [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: 07/04/2023] [Revised: 10/11/2023] [Accepted: 12/26/2023] [Indexed: 01/16/2024] Open
Abstract
Neuronal protein synthesis is required for long-lasting plasticity and long-term memory consolidation. Dephosphorylation of eukaryotic initiation factor 2α is one of the key translational control events that is required to increase de novo protein synthesis that underlies long-lasting plasticity and memory consolidation. Here, we interrogate the molecular pathways of translational control that are triggered by neuronal stimulation with brain-derived neurotrophic factor (BDNF), which results in eukaryotic initiation factor 2α (eIF2α) dephosphorylation and increases in de novo protein synthesis. Primary rodent neurons exposed to BDNF display elevated translation of GADD34, which facilitates eIF2α dephosphorylation and subsequent de novo protein synthesis. Furthermore, GADD34 requires G-actin generated by cofilin to dephosphorylate eIF2α and enhance protein synthesis. Finally, GADD34 is required for BDNF-induced translation of synaptic plasticity-related proteins. Overall, we provide evidence that neurons repurpose GADD34, an effector of the integrated stress response, as an orchestrator of rapid increases in eIF2-dependent translation in response to plasticity-inducing stimuli.
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Affiliation(s)
| | - Muhaned Mohamed
- Center for Neural Science, New York University, New York, NY, USA
| | - Megan K Elder
- Center for Neural Science, New York University, New York, NY, USA
| | | | - Maggie Mamcarz
- Center for Neural Science, New York University, New York, NY, USA
| | - Emily H Lu
- Center for Neural Science, New York University, New York, NY, USA
| | - Ela A N Golhan
- Center for Neural Science, New York University, New York, NY, USA
| | - Nishika Navrange
- Center for Neural Science, New York University, New York, NY, USA
| | - Snehajyoti Chatterjee
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Ted Abel
- Department of Neuroscience and Pharmacology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY, USA; NYU Neuroscience Institute, New York University School of Medicine, New York, NY, USA.
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Wang X, Leung FS, Bush JO, Conti M. Alternative cleavage and polyadenylation of the Ccnb1 mRNA defines accumulation of cyclin protein during the meiotic cell cycle. Nucleic Acids Res 2024; 52:1258-1271. [PMID: 38048302 PMCID: PMC10853788 DOI: 10.1093/nar/gkad1151] [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: 06/16/2023] [Revised: 11/01/2023] [Accepted: 11/14/2023] [Indexed: 12/06/2023] Open
Abstract
Progression through the mitotic and meiotic cell cycle is driven by fluctuations in the levels of cyclins, the regulatory subunits controlling the localization and activity of CDK1 kinases. Cyclin levels are regulated through a precise balance of synthesis and degradation. Here we demonstrate that the synthesis of Cyclin B1 during the oocyte meiotic cell cycle is defined by the selective translation of mRNA variants generated through alternative cleavage and polyadenylation (APA). Using gene editing in mice, we introduced mutations into the proximal and distal polyadenylation elements of the 3' untranslated region (UTR) of the Ccnb1 mRNA. Through in vivo loss-of-function experiments, we demonstrate that the translation of mRNA with a short 3' UTR specifies Cyclin B1 protein levels that set the timing of meiotic re-entry. In contrast, translation directed by a long 3' UTR is necessary to direct Cyclin B1 protein accumulation during the MI/MII transition. These findings establish that the progression through the cell cycle is dependent on the selective translation of multiple mRNA variants generated by APA.
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Affiliation(s)
- Xiaotian Wang
- Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
- USA Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA 94143, USA
| | - Fang-Shiuan Leung
- USA Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA 94143, USA
- Program in Craniofacial Biology, University of California San Francisco, San Francisco, CA 94143, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA
| | - Jeffrey O Bush
- USA Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA 94143, USA
- Program in Craniofacial Biology, University of California San Francisco, San Francisco, CA 94143, USA
- Institute for Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA
| | - Marco Conti
- Center for Reproductive Sciences, University of California, San Francisco, CA 94143, USA
- USA Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, CA 94143, USA
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA 94143, USA
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23
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Brüll M, Geese N, Celardo I, Laumann M, Leist M. Preparation of Viable Human Neurites for Neurobiological and Neurodegeneration Studies. Cells 2024; 13:242. [PMID: 38334634 PMCID: PMC10854604 DOI: 10.3390/cells13030242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024] Open
Abstract
Few models allow the study of neurite damage in the human central nervous system. We used here dopaminergic LUHMES neurons to establish a culture system that allows for (i) the observation of highly enriched neurites, (ii) the preparation of the neurite fraction for biochemical studies, and (iii) the measurement of neurite markers and metabolites after axotomy. LUHMES-based spheroids, plated in culture dishes, extended neurites of several thousand µm length, while all somata remained aggregated. These cultures allowed an easy microscopic observation of live or fixed neurites. Neurite-only cultures (NOC) were produced by cutting out the still-aggregated somata. The potential application of such cultures was exemplified by determinations of their protein and RNA contents. For instance, the mitochondrial TOM20 protein was highly abundant, while nuclear histone H3 was absent. Similarly, mitochondrial-encoded RNAs were found at relatively high levels, while the mRNA for a histone or the neuronal nuclear marker NeuN (RBFOX3) were relatively depleted in NOC. Another potential use of NOC is the study of neurite degeneration. For this purpose, an algorithm to quantify neurite integrity was developed. Using this tool, we found that the addition of nicotinamide drastically reduced neurite degeneration. Also, the chelation of Ca2+ in NOC delayed the degeneration, while inhibitors of calpains had no effect. Thus, NOC proved to be suitable for biochemical analysis and for studying degeneration processes after a defined cut injury.
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Affiliation(s)
- Markus Brüll
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Nils Geese
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Ivana Celardo
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
| | - Michael Laumann
- Electron Microscopy Centre, University of Konstanz, 78457 Konstanz, Germany;
| | - Marcel Leist
- In Vitro Toxicology and Biomedicine, Department Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, 78457 Konstanz, Germany; (M.B.); (N.G.); (I.C.)
- Center for Alternatives to Animal Testing in Europe (CAAT-Europe), University of Konstanz, 78457 Konstanz, Germany
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Veeraraghavan P, Engmann AK, Hatch JJ, Itoh Y, Nguyen D, Addison T, Macklis JD. Dynamic subtype- and context-specific subcellular RNA regulation in growth cones of developing neurons of the cerebral cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.24.559186. [PMID: 38328182 PMCID: PMC10849483 DOI: 10.1101/2023.09.24.559186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Molecular mechanisms that cells employ to compartmentalize function via localization of function-specific RNA and translation are only partially elucidated. We investigate long-range projection neurons of the cerebral cortex as highly polarized exemplars to elucidate dynamic regulation of RNA localization, stability, and translation within growth cones (GCs), leading tips of growing axons. Comparison of GC-localized transcriptomes between two distinct subtypes of projection neurons- interhemispheric-callosal and corticothalamic- across developmental stages identifies both distinct and shared subcellular machinery, and intriguingly highlights enrichment of genes associated with neurodevelopmental and neuropsychiatric disorders. Developmental context-specific components of GC-localized transcriptomes identify known and novel potential regulators of distinct phases of circuit formation: long-distance growth, target area innervation, and synapse formation. Further, we investigate mechanisms by which transcripts are enriched and dynamically regulated in GCs, and identify GC-enriched motifs in 3' untranslated regions. As one example, we identify cytoplasmic adenylation element binding protein 4 (CPEB4), an RNA binding protein regulating localization and translation of mRNAs encoding molecular machinery important for axonal branching and complexity. We also identify RNA binding motif single stranded interacting protein 1 (RBMS1) as a dynamically expressed regulator of RNA stabilization that enables successful callosal circuit formation. Subtly aberrant associative and integrative cortical circuitry can profoundly affect cortical function, often causing neurodevelopmental and neuropsychiatric disorders. Elucidation of context-specific subcellular RNA regulation for GC- and soma-localized molecular controls over precise circuit development, maintenance, and function offers generalizable insights for other polarized cells, and might contribute substantially to understanding neurodevelopmental and behavioral-cognitive disorders and toward targeted therapeutics.
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Affiliation(s)
- Priya Veeraraghavan
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Anne K. Engmann
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - John J. Hatch
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Yasuhiro Itoh
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Duane Nguyen
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Thomas Addison
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Jeffrey D. Macklis
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, MA, USA
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25
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Wong HHW, Watt AJ, Sjöström PJ. Synapse-specific burst coding sustained by local axonal translation. Neuron 2024; 112:264-276.e6. [PMID: 37944518 DOI: 10.1016/j.neuron.2023.10.011] [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: 06/05/2023] [Revised: 08/19/2023] [Accepted: 09/13/2023] [Indexed: 11/12/2023]
Abstract
Neurotransmission in the brain is unreliable, suggesting that high-frequency spike bursts rather than individual spikes carry the neural code. For instance, cortical pyramidal neurons rely on bursts in memory formation. Protein synthesis is another key factor in long-term synaptic plasticity and learning but is widely considered unnecessary for synaptic transmission. Here, however, we show that burst neurotransmission at synapses between neocortical layer 5 pyramidal cells depends on axonal protein synthesis linked to presynaptic NMDA receptors and mTOR. We localized protein synthesis to axons with laser axotomy and puromycylation live imaging. We whole-cell recorded connected neurons to reveal how translation sustained readily releasable vesicle pool size and replenishment rate. We live imaged axons and found sparsely docked RNA granules, suggesting synapse-specific regulation. In agreement, translation boosted neurotransmission onto excitatory but not inhibitory basket or Martinotti cells. Local axonal mRNA translation is thus a hitherto unappreciated principle for sustaining burst coding at specific synapse types.
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Affiliation(s)
- Hovy Ho-Wai Wong
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC H3G 1A4, Canada.
| | - Alanna J Watt
- Biology Department, McGill University, Montreal, QC H3G 0B1, Canada
| | - P Jesper Sjöström
- Centre for Research in Neuroscience, Brain Repair and Integrative Neuroscience Program, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC H3G 1A4, Canada.
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26
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Moya-Alvarado G, Aguirre-Soto A, Bronfman FC. Multiple Labeling of Compartmentalized Cortical Neurons in Microfluidic Chambers. Bio Protoc 2024; 14:e4911. [PMID: 38213323 PMCID: PMC10777054 DOI: 10.21769/bioprotoc.4911] [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: 09/13/2023] [Revised: 11/13/2023] [Accepted: 11/17/2023] [Indexed: 01/13/2024] Open
Abstract
Neurons are complex cells with two distinct compartments: the somatodendritic and the axonal domains. Because of their polarized morphology, it is challenging to study the differential cellular and molecular mechanisms that occur in axons and impact the soma and dendrites using conventional in vitro culture systems. Compartmentalized cultures offer a solution by physically and chemically separating the axonal from the somatodendritic domain of neurons. The microfluidic chamber model presented in this work is valuable for studying these mechanisms in primary cortical cultures derived from rat and mouse. In addition, this chamber model is compatible with various microscopy methods, such as phase contrast, and fluorescence imaging of living and fixed cells. Key features • Preparation and attachment of PDMS microfluidic chambers to glass coverslips. • Primary culture of cortical neurons and plating cortical neurons in microfluidic chamber. • Confirmation of compartmentalization using the retrograde transport of the fluorescently labeled form of cholera toxin subunit B (f-Ctb). • Immunofluorescence and multilabeling of compartmentalized cortical neurons. • Retrograde transport of fluorescently labeled BDNF.
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Affiliation(s)
- Guillermo Moya-Alvarado
- Department of Physiology, Faculty of Biological Sciences and Center for Aging and Regeneration (CARE), Pontificia Universidad Catolica de Chile, Av. Libertador Bernardo O´Higgins 340, Santiago, 8970117, Chile
| | - Alejandro Aguirre-Soto
- NeuroSignaling Lab (NESLab), Institute of Biomedical Sciences (ICB), Faculty of Medicine, and Faculty of Life Sciences, Universidad Andres Bello, Echaurren 183, 8370146, Santiago, Chile
| | - Francisca C. Bronfman
- NeuroSignaling Lab (NESLab), Institute of Biomedical Sciences (ICB), Faculty of Medicine, and Faculty of Life Sciences, Universidad Andres Bello, Echaurren 183, 8370146, Santiago, Chile
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27
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Alexandris AS, Koliatsos VE. NAD +, Axonal Maintenance, and Neurological Disease. Antioxid Redox Signal 2023; 39:1167-1184. [PMID: 37503611 PMCID: PMC10715442 DOI: 10.1089/ars.2023.0350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 05/28/2023] [Indexed: 07/29/2023]
Abstract
Significance: The remarkable geometry of the axon exposes it to unique challenges for survival and maintenance. Axonal degeneration is a feature of peripheral neuropathies, glaucoma, and traumatic brain injury, and an early event in neurodegenerative diseases. Since the discovery of Wallerian degeneration (WD), a molecular program that hijacks nicotinamide adenine dinucleotide (NAD+) metabolism for axonal self-destruction, the complex roles of NAD+ in axonal viability and disease have become research priority. Recent Advances: The discoveries of the protective Wallerian degeneration slow (WldS) and of sterile alpha and TIR motif containing 1 (SARM1) activation as the main instructive signal for WD have shed new light on the regulatory role of NAD+ in axonal degeneration in a growing number of neurological diseases. SARM1 has been characterized as a NAD+ hydrolase and sensor of NAD+ metabolism. The discovery of regulators of nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) proteostasis in axons, the allosteric regulation of SARM1 by NAD+ and NMN, and the existence of clinically relevant windows of action of these signals has opened new opportunities for therapeutic interventions, including SARM1 inhibitors and modulators of NAD+ metabolism. Critical Issues: Events upstream and downstream of SARM1 remain unclear. Furthermore, manipulating NAD+ metabolism, an overdetermined process crucial in cell survival, for preventing the degeneration of the injured axon may be difficult and potentially toxic. Future Directions: There is a need for clarification of the distinct roles of NAD+ metabolism in axonal maintenance as contrasted to WD. There is also a need to better understand the role of NAD+ metabolism in axonal endangerment in neuropathies, diseases of the white matter, and the early stages of neurodegenerative diseases of the central nervous system. Antioxid. Redox Signal. 39, 1167-1184.
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Affiliation(s)
| | - Vassilis E. Koliatsos
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, and Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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28
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Pisciottani A, Croci L, Lauria F, Marullo C, Savino E, Ambrosi A, Podini P, Marchioretto M, Casoni F, Cremona O, Taverna S, Quattrini A, Cioni JM, Viero G, Codazzi F, Consalez GG. Neuronal models of TDP-43 proteinopathy display reduced axonal translation, increased oxidative stress, and defective exocytosis. Front Cell Neurosci 2023; 17:1253543. [PMID: 38026702 PMCID: PMC10679756 DOI: 10.3389/fncel.2023.1253543] [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: 07/05/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive, lethal neurodegenerative disease mostly affecting people around 50-60 years of age. TDP-43, an RNA-binding protein involved in pre-mRNA splicing and controlling mRNA stability and translation, forms neuronal cytoplasmic inclusions in an overwhelming majority of ALS patients, a phenomenon referred to as TDP-43 proteinopathy. These cytoplasmic aggregates disrupt mRNA transport and localization. The axon, like dendrites, is a site of mRNA translation, permitting the local synthesis of selected proteins. This is especially relevant in upper and lower motor neurons, whose axon spans long distances, likely accentuating their susceptibility to ALS-related noxae. In this work we have generated and characterized two cellular models, consisting of virtually pure populations of primary mouse cortical neurons expressing a human TDP-43 fusion protein, wt or carrying an ALS mutation. Both forms facilitate cytoplasmic aggregate formation, unlike the corresponding native proteins, giving rise to bona fide primary culture models of TDP-43 proteinopathy. Neurons expressing TDP-43 fusion proteins exhibit a global impairment in axonal protein synthesis, an increase in oxidative stress, and defects in presynaptic function and electrical activity. These changes correlate with deregulation of axonal levels of polysome-engaged mRNAs playing relevant roles in the same processes. Our data support the emerging notion that deregulation of mRNA metabolism and of axonal mRNA transport may trigger the dying-back neuropathy that initiates motor neuron degeneration in ALS.
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Affiliation(s)
- Alessandra Pisciottani
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Laura Croci
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Fabio Lauria
- Institute of Biophysics, CNR Unit at Trento, Povo, Italy
| | - Chiara Marullo
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Elisa Savino
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessandro Ambrosi
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paola Podini
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | - Filippo Casoni
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Ottavio Cremona
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
| | - Stefano Taverna
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Angelo Quattrini
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Jean-Michel Cioni
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | | | - Franca Codazzi
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - G. Giacomo Consalez
- Faculty of Medicine and Surgery, Università Vita-Salute San Raffaele, Milan, Italy
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
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29
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Kwan Z, Paulose Nadappuram B, Leung MM, Mohagaonkar S, Li A, Amaradasa KS, Chen J, Rothery S, Kibreab I, Fu J, Sanchez-Alonso JL, Mansfield CA, Subramanian H, Kondrashov A, Wright PT, Swiatlowska P, Nikolaev VO, Wojciak-Stothard B, Ivanov AP, Edel JB, Gorelik J. Microtubule-Mediated Regulation of β 2AR Translation and Function in Failing Hearts. Circ Res 2023; 133:944-958. [PMID: 37869877 PMCID: PMC10635332 DOI: 10.1161/circresaha.123.323174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/24/2023]
Abstract
BACKGROUND β1AR (beta-1 adrenergic receptor) and β2AR (beta-2 adrenergic receptor)-mediated cyclic adenosine monophosphate signaling has distinct effects on cardiac function and heart failure progression. However, the mechanism regulating spatial localization and functional compartmentation of cardiac β-ARs remains elusive. Emerging evidence suggests that microtubule-dependent trafficking of mRNP (messenger ribonucleoprotein) and localized protein translation modulates protein compartmentation in cardiomyocytes. We hypothesized that β-AR compartmentation in cardiomyocytes is accomplished by selective trafficking of its mRNAs and localized translation. METHODS The localization pattern of β-AR mRNA was investigated using single molecule fluorescence in situ hybridization and subcellular nanobiopsy in rat cardiomyocytes. The role of microtubule on β-AR mRNA localization was studied using vinblastine, and its effect on receptor localization and function was evaluated with immunofluorescent and high-throughput Förster resonance energy transfer microscopy. An mRNA protein co-detection assay identified plausible β-AR translation sites in cardiomyocytes. The mechanism by which β-AR mRNA is redistributed post-heart failure was elucidated by single molecule fluorescence in situ hybridization, nanobiopsy, and high-throughput Förster resonance energy transfer microscopy on 16 weeks post-myocardial infarction and detubulated cardiomyocytes. RESULTS β1AR and β2AR mRNAs show differential localization in cardiomyocytes, with β1AR found in the perinuclear region and β2AR showing diffuse distribution throughout the cell. Disruption of microtubules induces a shift of β2AR transcripts toward the perinuclear region. The close proximity between β2AR transcripts and translated proteins suggests that the translation process occurs in specialized, precisely defined cellular compartments. Redistribution of β2AR transcripts is microtubule-dependent, as microtubule depolymerization markedly reduces the number of functional receptors on the membrane. In failing hearts, both β1AR and β2AR mRNAs are redistributed toward the cell periphery, similar to what is seen in cardiomyocytes undergoing drug-induced detubulation. This suggests that t-tubule remodeling contributes to β-AR mRNA redistribution and impaired β2AR function in failing hearts. CONCLUSIONS Asymmetrical microtubule-dependent trafficking dictates differential β1AR and β2AR localization in healthy cardiomyocyte microtubules, underlying the distinctive compartmentation of the 2 β-ARs on the plasma membrane. The localization pattern is altered post-myocardial infarction, resulting from transverse tubule remodeling, leading to distorted β2AR-mediated cyclic adenosine monophosphate signaling.
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MESH Headings
- Rats
- Animals
- In Situ Hybridization, Fluorescence
- Heart Failure/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Myocardial Infarction/metabolism
- Myocytes, Cardiac/metabolism
- Cyclic AMP/metabolism
- Receptors, Adrenergic, beta-1/metabolism
- Microtubules/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Adenosine Monophosphate/metabolism
- Adenosine Monophosphate/pharmacology
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Affiliation(s)
- Zoe Kwan
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
| | - Binoy Paulose Nadappuram
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
- Department of Pure and Applied Chemistry, University of Strathclyde, United Kingdom (B.P.N.)
| | - Manton M. Leung
- Sir William Dunn School of Pathology, University of Oxford, United Kingdom (M.M.L.)
| | - Sanika Mohagaonkar
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Ao Li
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Kumuthu S. Amaradasa
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Ji Chen
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Stephen Rothery
- FILM Facility, Imperial College London, United Kingdom (S.R.)
| | - Iyobel Kibreab
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Jiarong Fu
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Jose L. Sanchez-Alonso
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Catherine A. Mansfield
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | | | - Alexander Kondrashov
- Division of Cancer and Stem Cells, University of Nottingham Biodiscovery Institute, United Kingdom (A.K.)
| | - Peter T. Wright
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
- School of Life and Health Sciences, University of Roehampton, United Kingdom (P.T.W.)
| | - Pamela Swiatlowska
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Viacheslav O. Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center, Hamburg-Eppendorf, Germany (H.S., V.O.N.)
| | - Beata Wojciak-Stothard
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
| | - Aleksandar P. Ivanov
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
| | - Joshua B. Edel
- Department of Chemistry (Z.K., B.P.N., A.P.I., J.B.E.), Imperial College London, United Kingdom
| | - Julia Gorelik
- National Heart and Lung Institute (Z.K., S.M., A.L., K.S.A., J.C., I.K., J.F., J.L.S.-A., C.A.M., P.S., B.W.-S., P.T.W., J.G.), Imperial College London, United Kingdom
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Castillo PE, Jung H, Klann E, Riccio A. Presynaptic Protein Synthesis in Brain Function and Disease. J Neurosci 2023; 43:7483-7488. [PMID: 37940588 PMCID: PMC10634577 DOI: 10.1523/jneurosci.1454-23.2023] [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: 08/01/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 11/10/2023] Open
Abstract
Local protein synthesis in mature brain axons regulates the structure and function of presynaptic boutons by adjusting the presynaptic proteome to local demands. This crucial mechanism underlies experience-dependent modifications of brain circuits, and its dysregulation may contribute to brain disorders, such as autism and intellectual disability. Here, we discuss recent advancements in the axonal transcriptome, axonal RNA localization and translation, and the role of presynaptic local translation in synaptic plasticity and memory.
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Affiliation(s)
- Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Hosung Jung
- Department of Anatomy, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, 03722, Republic of Korea
| | - Eric Klann
- Center for Neural Science, New York University, New York, New York 10003
- New York University Neuroscience Institute, New York University Grossman School of Medicine, New York, New York 10016
| | - Antonella Riccio
- UCL Laboratory for Molecular Cell Biology University College London, London, WC1E 6BT, United Kingdom
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31
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Cagnetta R, Flanagan JG, Sonenberg N. Control of Selective mRNA Translation in Neuronal Subcellular Compartments in Health and Disease. J Neurosci 2023; 43:7247-7263. [PMID: 37914402 PMCID: PMC10621772 DOI: 10.1523/jneurosci.2240-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 11/03/2023] Open
Abstract
In multiple cell types, mRNAs are transported to subcellular compartments, where local translation enables rapid, spatially localized, and specific responses to external stimuli. Mounting evidence has uncovered important roles played by local translation in vivo in axon survival, axon regeneration, and neural wiring, as well as strong links between dysregulation of local translation and neurologic disorders. Omic studies have revealed that >1000 mRNAs are present and can be selectively locally translated in the presynaptic and postsynaptic compartments from development to adulthood in vivo A large proportion of the locally translated mRNAs is specifically upregulated or downregulated in response to distinct extracellular signals. Given that the local translatome is large, selectively translated, and cue-specifically remodeled, a fundamental question concerns how selective translation is achieved locally. Here, we review the emerging regulatory mechanisms of local selective translation in neuronal subcellular compartments, their mRNA targets, and their orchestration. We discuss mechanisms of local selective translation that remain unexplored. Finally, we describe clinical implications and potential therapeutic strategies in light of the latest advances in gene therapy.
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Affiliation(s)
- Roberta Cagnetta
- Department of Biochemistry and Goodman Cancer Institute, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - John G Flanagan
- Department of Cell Biology and Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Institute, McGill University, Montreal, Quebec H3A 1A3, Canada
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32
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Davletshin AI, Matveeva AA, Poletaeva II, Evgen'ev MB, Garbuz DG. The role of molecular chaperones in the mechanisms of epileptogenesis. Cell Stress Chaperones 2023; 28:599-619. [PMID: 37755620 PMCID: PMC10746656 DOI: 10.1007/s12192-023-01378-1] [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: 07/17/2023] [Revised: 08/30/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
Epilepsy is a group of neurological diseases which requires significant economic costs for the treatment and care of patients. The central point of epileptogenesis stems from the failure of synaptic signal transmission mechanisms, leading to excessive synchronous excitation of neurons and characteristic epileptic electroencephalogram activity, in typical cases being manifested as seizures and loss of consciousness. The causes of epilepsy are extremely diverse, which is one of the reasons for the complexity of selecting a treatment regimen for each individual case and the high frequency of pharmacoresistant cases. Therefore, the search for new drugs and methods of epilepsy treatment requires an advanced study of the molecular mechanisms of epileptogenesis. In this regard, the investigation of molecular chaperones as potential mediators of epileptogenesis seems promising because the chaperones are involved in the processing and regulation of the activity of many key proteins directly responsible for the generation of abnormal neuronal excitation in epilepsy. In this review, we try to systematize current data on the role of molecular chaperones in epileptogenesis and discuss the prospects for the use of chemical modulators of various chaperone groups' activity as promising antiepileptic drugs.
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Affiliation(s)
| | - Anna A Matveeva
- Engelhardt Institute of Molecular Biology RAS, 119991, Moscow, Russia
- Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Moscow Region, Russia
| | - Inga I Poletaeva
- Biology Department, Lomonosov Moscow State University, 119991, Moscow, Russia
| | | | - David G Garbuz
- Engelhardt Institute of Molecular Biology RAS, 119991, Moscow, Russia
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Dissing-Olesen L, Walker AJ, Feng Q, Barr HJ, Walker AC, Xie L, Wilton DK, Das I, Benowitz LI, Stevens B. FEAST: A flow cytometry-based toolkit for interrogating microglial engulfment of synaptic and myelin proteins. Nat Commun 2023; 14:6015. [PMID: 37758703 PMCID: PMC10533836 DOI: 10.1038/s41467-023-41448-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Although engulfment is a hallmark of microglia function, fully validated platforms that facilitate high-throughput quantification of this process are lacking. Here, we present FEAST (Flow cytometric Engulfment Assay for Specific Target proteins), which enables interrogation of in vivo engulfment of synaptic material by brain resident macrophages at single-cell resolution. We optimize FEAST for two different analyses: quantification of fluorescent material inside live cells and of engulfed endogenous proteins within fixed cells. To overcome false-positive engulfment signals, we introduce an approach suitable for interrogating engulfment in microglia from perfusion-fixed tissue. As a proof-of-concept for the specificity and versatility of FEAST, we examine the engulfment of synaptic proteins after optic nerve crush and of myelin in two mouse models of demyelination (treatment with cuprizone and injections of lysolecithin). We find that microglia, but not brain-border associated macrophages, engulf in these contexts. Our work underscores how FEAST can be utilized to gain critical insight into functional neuro-immune interactions that shape development, homeostasis, and disease.
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Affiliation(s)
- Lasse Dissing-Olesen
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Alec J Walker
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Qian Feng
- Department of Neurosurgery, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
| | - Helena J Barr
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Alicia C Walker
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - Lili Xie
- Department of Neurosurgery, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
| | - Daniel K Wilton
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA
| | - Indrani Das
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Harvard Medical School, Boston, MA, 02115, USA
| | - Larry I Benowitz
- Department of Neurosurgery, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA
- Ophthalmology, Harvard Medical School, Boston, MA, 02115, USA
| | - Beth Stevens
- Department of Neurology, Boston Children's Hospital, F.M. Kirby Neurobiology Center, Boston, MA, 02115, USA.
- Harvard Medical School, Boston, MA, 02115, USA.
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, 02139, USA.
- Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA, 02115, USA.
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34
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Davies FCJ, Marshall GF, Pegram E, Gadd D, Abbott CM. Endogenous epitope tagging of eEF1A2 in mice reveals early embryonic expression of eEF1A2 and subcellular compartmentalisation of neuronal eEF1A1 and eEF1A2. Mol Cell Neurosci 2023; 126:103879. [PMID: 37429391 DOI: 10.1016/j.mcn.2023.103879] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/29/2023] [Accepted: 07/06/2023] [Indexed: 07/12/2023] Open
Abstract
All vertebrate species express two independently-encoded forms of translation elongation factor eEF1A. In humans and mice eEF1A1 and eEF1A2 are 92 % identical at the amino acid level, but the well conserved developmental switch between the two variants in specific tissues suggests the existence of important functional differences. Heterozygous mutations in eEF1A2 result in neurodevelopmental disorders in humans; the mechanism of pathogenicity is unclear, but one hypothesis is that there is a dominant negative effect on eEF1A1 during development. The high degree of similarity between the eEF1A proteins has complicated expression analysis in the past; here we describe a gene edited mouse line in which we have introduced a V5 tag in the gene encoding eEF1A2. Expression analysis using anti-V5 and anti-eEF1A1 antibodies demonstrates that, in contrast to the prevailing view that eEF1A2 is only expressed postnatally, it is expressed from as early as E11.5 in the developing neural tube. Two colour immunofluorescence also reveals coordinated switching between eEF1A1 and eEF1A2 in different regions of postnatal brain. Completely reciprocal expression of the two variants is seen in post-weaning mouse brain with eEF1A1 expressed in oligodendrocytes and astrocytes and eEF1A2 in neuronal soma. Although eEF1A1 is absent from neuronal cell bodies after development, it is widely expressed in axons. This expression does not appear to coincide with myelin sheaths originating from oligodendrocytes but rather results from localised translation within the axon, suggesting that both variants are transcribed in neurons but show completely distinct subcellular localisation at the protein level. These findings will form an underlying framework for understanding how missense mutations in eEF1A2 result in neurodevelopmental disorders.
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Affiliation(s)
- Faith C J Davies
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Grant F Marshall
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Eleanor Pegram
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Danni Gadd
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom
| | - Catherine M Abbott
- Centre for Genomic & Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom.
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35
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Wang S, Sun S. Translation dysregulation in neurodegenerative diseases: a focus on ALS. Mol Neurodegener 2023; 18:58. [PMID: 37626421 PMCID: PMC10464328 DOI: 10.1186/s13024-023-00642-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 07/21/2023] [Indexed: 08/27/2023] Open
Abstract
RNA translation is tightly controlled in eukaryotic cells to regulate gene expression and maintain proteome homeostasis. RNA binding proteins, translation factors, and cell signaling pathways all modulate the translation process. Defective translation is involved in multiple neurological diseases including amyotrophic lateral sclerosis (ALS). ALS is a progressive neurodegenerative disorder and poses a major public health challenge worldwide. Over the past few years, tremendous advances have been made in the understanding of the genetics and pathogenesis of ALS. Dysfunction of RNA metabolisms, including RNA translation, has been closely associated with ALS. Here, we first introduce the general mechanisms of translational regulation under physiological and stress conditions and review well-known examples of translation defects in neurodegenerative diseases. We then focus on ALS-linked genes and discuss the recent progress on how translation is affected by various mutant genes and the repeat expansion-mediated non-canonical translation in ALS.
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Affiliation(s)
- Shaopeng Wang
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Shuying Sun
- Department of Physiology and Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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36
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Chandra S, Chatterjee R, Olmsted ZT, Mukherjee A, Paluh JL. Axonal transport during injury on a theoretical axon. Front Cell Neurosci 2023; 17:1215945. [PMID: 37636588 PMCID: PMC10450981 DOI: 10.3389/fncel.2023.1215945] [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: 05/02/2023] [Accepted: 07/12/2023] [Indexed: 08/29/2023] Open
Abstract
Neurodevelopment, plasticity, and cognition are integral with functional directional transport in neuronal axons that occurs along a unique network of discontinuous polar microtubule (MT) bundles. Axonopathies are caused by brain trauma and genetic diseases that perturb or disrupt the axon MT infrastructure and, with it, the dynamic interplay of motor proteins and cargo essential for axonal maintenance and neuronal signaling. The inability to visualize and quantify normal and altered nanoscale spatio-temporal dynamic transport events prevents a full mechanistic understanding of injury, disease progression, and recovery. To address this gap, we generated DyNAMO, a Dynamic Nanoscale Axonal MT Organization model, which is a biologically realistic theoretical axon framework. We use DyNAMO to experimentally simulate multi-kinesin traffic response to focused or distributed tractable injury parameters, which are MT network perturbations affecting MT lengths and multi-MT staggering. We track kinesins with different motility and processivity, as well as their influx rates, in-transit dissociation and reassociation from inter-MT reservoirs, progression, and quantify and spatially represent motor output ratios. DyNAMO demonstrates, in detail, the complex interplay of mixed motor types, crowding, kinesin off/on dissociation and reassociation, and injury consequences of forced intermingling. Stalled forward progression with different injury states is seen as persistent dynamicity of kinesins transiting between MTs and inter-MT reservoirs. DyNAMO analysis provides novel insights and quantification of axonal injury scenarios, including local injury-affected ATP levels, as well as relates these to influences on signaling outputs, including patterns of gating, waves, and pattern switching. The DyNAMO model significantly expands the network of heuristic and mathematical analysis of neuronal functions relevant to axonopathies, diagnostics, and treatment strategies.
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Affiliation(s)
- Soumyadeep Chandra
- Electrical and Computer Science Engineering, Purdue University, West Lafayette, IN, United States
| | - Rounak Chatterjee
- Department of Electronics, Electrical and Systems Engineering, University of Birmingham, Birmingham, United Kingdom
| | - Zachary T. Olmsted
- Nanobioscience, College of Nanoscale Science and Engineering, State University of New York Polytechnic Institute, Albany, NY, United States
- Department of Neurosurgery, Ronald Reagan UCLA Medical Center, University of California, Los Angeles, Los Angeles, CA, United States
| | - Amitava Mukherjee
- Nanobioscience, College of Nanoscale Science and Engineering, State University of New York Polytechnic Institute, Albany, NY, United States
- School of Computing, Amrita Vishwa Vidyapeetham (University), Kollam, Kerala, India
| | - Janet L. Paluh
- Nanobioscience, College of Nanoscale Science and Engineering, State University of New York Polytechnic Institute, Albany, NY, United States
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37
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Loedige I, Baranovskii A, Mendonsa S, Dantsuji S, Popitsch N, Breimann L, Zerna N, Cherepanov V, Milek M, Ameres S, Chekulaeva M. mRNA stability and m 6A are major determinants of subcellular mRNA localization in neurons. Mol Cell 2023; 83:2709-2725.e10. [PMID: 37451262 PMCID: PMC10529935 DOI: 10.1016/j.molcel.2023.06.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/04/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
For cells to perform their biological functions, they need to adopt specific shapes and form functionally distinct subcellular compartments. This is achieved in part via an asymmetric distribution of mRNAs within cells. Currently, the main model of mRNA localization involves specific sequences called "zipcodes" that direct mRNAs to their proper locations. However, while thousands of mRNAs localize within cells, only a few zipcodes have been identified, suggesting that additional mechanisms contribute to localization. Here, we assess the role of mRNA stability in localization by combining the isolation of the soma and neurites of mouse primary cortical and mESC-derived neurons, SLAM-seq, m6A-RIP-seq, the perturbation of mRNA destabilization mechanisms, and the analysis of multiple mRNA localization datasets. We show that depletion of mRNA destabilization elements, such as m6A, AU-rich elements, and suboptimal codons, functions as a mechanism that mediates the localization of mRNAs associated with housekeeping functions to neurites in several types of neurons.
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Affiliation(s)
- Inga Loedige
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Artem Baranovskii
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Samantha Mendonsa
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Sayaka Dantsuji
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Niko Popitsch
- Max Perutz Labs, University of Vienna, Vienna BioCenter, 1030 Vienna, Austria
| | - Laura Breimann
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany; Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Nadja Zerna
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Vsevolod Cherepanov
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Miha Milek
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany
| | - Stefan Ameres
- Max Perutz Labs, University of Vienna, Vienna BioCenter, 1030 Vienna, Austria
| | - Marina Chekulaeva
- Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine, Berlin 10115, Germany.
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38
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Ament SA, Poulopoulos A. The brain's dark transcriptome: Sequencing RNA in distal compartments of neurons and glia. Curr Opin Neurobiol 2023; 81:102725. [PMID: 37196598 PMCID: PMC10524153 DOI: 10.1016/j.conb.2023.102725] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/22/2023] [Accepted: 04/02/2023] [Indexed: 05/19/2023]
Abstract
Transcriptomic approaches are powerful strategies to map the molecular diversity of cells in the brain. Single-cell genomic atlases have now been compiled for entire mammalian brains. However, complementary techniques are only just beginning to map the subcellular transcriptomes from distal cellular compartments. We review single-cell datasets alongside subtranscriptome data from the mammalian brain to explore the development of cellular and subcellular diversity. We discuss how single-cell RNA-seq misses transcripts localized away from cell bodies, which form the 'dark transcriptome' of the brain: a collection of subtranscriptomes in dendrites, axons, growth cones, synapses, and endfeet with important roles in brain development and function. Recent advances in subcellular transcriptome sequencing are beginning to reveal these elusive pools of RNA. We outline the success stories to date in uncovering the constituent subtranscriptomes of neurons and glia, as well as present the emerging toolkit that is accelerating the pace of subtranscriptome discovery.
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Affiliation(s)
- Seth A Ament
- Department of Psychiatry, UM-MIND, and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alexandros Poulopoulos
- Department of Pharmacology and UM-MIND, University of Maryland School of Medicine, Baltimore, MD, USA.
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39
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Salehi S, Zare A, Prezza G, Bader J, Schneider C, Fischer U, Meissner F, Mann M, Briese M, Sendtner M. Cytosolic Ptbp2 modulates axon growth in motoneurons through axonal localization and translation of Hnrnpr. Nat Commun 2023; 14:4158. [PMID: 37438340 DOI: 10.1038/s41467-023-39787-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 06/28/2023] [Indexed: 07/14/2023] Open
Abstract
The neuronal RNA-binding protein Ptbp2 regulates neuronal differentiation by modulating alternative splicing programs in the nucleus. Such programs contribute to axonogenesis by adjusting the levels of protein isoforms involved in axon growth and branching. While its functions in alternative splicing have been described in detail, cytosolic roles of Ptbp2 for axon growth have remained elusive. Here, we show that Ptbp2 is located in the cytosol including axons and growth cones of motoneurons, and that depletion of cytosolic Ptbp2 affects axon growth. We identify Ptbp2 as a major interactor of the 3' UTR of Hnrnpr mRNA encoding the RNA-binding protein hnRNP R. Axonal localization of Hnrnpr mRNA and local synthesis of hnRNP R protein are strongly reduced when Ptbp2 is depleted, leading to defective axon growth. Ptbp2 regulates hnRNP R translation by mediating the association of Hnrnpr with ribosomes in a manner dependent on the translation factor eIF5A2. Our data thus suggest a mechanism whereby cytosolic Ptbp2 modulates axon growth by fine-tuning the mRNA transport and local synthesis of an RNA-binding protein.
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Affiliation(s)
- Saeede Salehi
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Abdolhossein Zare
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Gianluca Prezza
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Wuerzburg, Germany
| | - Jakob Bader
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Cornelius Schneider
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Felix Meissner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
- Experimental Systems Immunology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Institute of Innate Immunity, Department of Systems Immunology and Proteomics, Medical Faculty, University of Bonn, Bonn, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
- NNF Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Briese
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
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40
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Son KH, Aldonza MBD, Nam AR, Lee KH, Lee JW, Shin KJ, Kang K, Cho JY. Integrative mapping of the dog epigenome: Reference annotation for comparative intertissue and cross-species studies. SCIENCE ADVANCES 2023; 9:eade3399. [PMID: 37406108 DOI: 10.1126/sciadv.ade3399] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 06/02/2023] [Indexed: 07/07/2023]
Abstract
Dogs have become a valuable model in exploring multifaceted diseases and biology relevant to human health. Despite large-scale dog genome projects producing high-quality draft references, a comprehensive annotation of functional elements is still lacking. We addressed this through integrative next-generation sequencing of transcriptomes paired with five histone marks and DNA methylome profiling across 11 tissue types, deciphering the dog's epigenetic code by defining distinct chromatin states, super-enhancer, and methylome landscapes, and thus showed that these regions are associated with a wide range of biological functions and cell/tissue identity. In addition, we confirmed that the phenotype-associated variants are enriched in tissue-specific regulatory regions and, therefore, the tissue of origin of the variants can be traced. Ultimately, we delineated conserved and dynamic epigenomic changes at the tissue- and species-specific resolutions. Our study provides an epigenomic blueprint of the dog that can be used for comparative biology and medical research.
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Affiliation(s)
- Keun Hong Son
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Comparative Medicine and Disease Research Center (CDRC), Science Research Center (SRC), Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Mark Borris D Aldonza
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Comparative Medicine and Disease Research Center (CDRC), Science Research Center (SRC), Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - A-Reum Nam
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Comparative Medicine and Disease Research Center (CDRC), Science Research Center (SRC), Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Kang-Hoon Lee
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Jeong-Woon Lee
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Comparative Medicine and Disease Research Center (CDRC), Science Research Center (SRC), Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Kyung-Ju Shin
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Keunsoo Kang
- Department of Microbiology, College of Natural Sciences, Dankook University, Cheonan, Korea
| | - Je-Yoel Cho
- Department of Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul, Korea
- Comparative Medicine and Disease Research Center (CDRC), Science Research Center (SRC), Seoul National University, Seoul, Korea
- BK21 PLUS Program for Creative Veterinary Science Research and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
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41
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Titlow JS, Kiourlappou M, Palanca A, Lee JY, Gala DS, Ennis D, Yu JJ, Young FL, Susano Pinto DM, Garforth S, Francis HS, Strivens F, Mulvey H, Dallman-Porter A, Thornton S, Arman D, Millard MJ, Järvelin AI, Thompson MK, Sargent M, Kounatidis I, Parton RM, Taylor S, Davis I. Systematic analysis of YFP traps reveals common mRNA/protein discordance in neural tissues. J Cell Biol 2023; 222:e202205129. [PMID: 37145332 PMCID: PMC10165541 DOI: 10.1083/jcb.202205129] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 11/11/2022] [Accepted: 12/06/2022] [Indexed: 05/06/2023] Open
Abstract
While post-transcriptional control is thought to be required at the periphery of neurons and glia, its extent is unclear. Here, we investigate systematically the spatial distribution and expression of mRNA at single molecule sensitivity and their corresponding proteins of 200 YFP trap lines across the intact Drosophila nervous system. 97.5% of the genes studied showed discordance between the distribution of mRNA and the proteins they encode in at least one region of the nervous system. These data suggest that post-transcriptional regulation is very common, helping to explain the complexity of the nervous system. We also discovered that 68.5% of these genes have transcripts present at the periphery of neurons, with 9.5% at the glial periphery. Peripheral transcripts include many potential new regulators of neurons, glia, and their interactions. Our approach is applicable to most genes and tissues and includes powerful novel data annotation and visualization tools for post-transcriptional regulation.
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Affiliation(s)
| | | | - Ana Palanca
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Jeffrey Y. Lee
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Dalia S. Gala
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Darragh Ennis
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Joyce J.S. Yu
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | - Sam Garforth
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Finn Strivens
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Hugh Mulvey
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Staci Thornton
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Diana Arman
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | | | - Martin Sargent
- Weatherall Institute for Molecular Medicine, University of Oxford, Oxford, UK
| | | | | | - Stephen Taylor
- Weatherall Institute for Molecular Medicine, University of Oxford, Oxford, UK
| | - Ilan Davis
- Department of Biochemistry, University of Oxford, Oxford, UK
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42
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Shafqat A, Albalkhi I, Magableh HM, Saleh T, Alkattan K, Yaqinuddin A. Tackling the glial scar in spinal cord regeneration: new discoveries and future directions. Front Cell Neurosci 2023; 17:1180825. [PMID: 37293626 PMCID: PMC10244598 DOI: 10.3389/fncel.2023.1180825] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/08/2023] [Indexed: 06/10/2023] Open
Abstract
Axonal regeneration and functional recovery are poor after spinal cord injury (SCI), typified by the formation of an injury scar. While this scar was traditionally believed to be primarily responsible for axonal regeneration failure, current knowledge takes a more holistic approach that considers the intrinsic growth capacity of axons. Targeting the SCI scar has also not reproducibly yielded nearly the same efficacy in animal models compared to these neuron-directed approaches. These results suggest that the major reason behind central nervous system (CNS) regeneration failure is not the injury scar but a failure to stimulate axon growth adequately. These findings raise questions about whether targeting neuroinflammation and glial scarring still constitute viable translational avenues. We provide a comprehensive review of the dual role of neuroinflammation and scarring after SCI and how future research can produce therapeutic strategies targeting the hurdles to axonal regeneration posed by these processes without compromising neuroprotection.
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43
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Hafner AS, Triesch J. Synaptic logistics: Competing over shared resources. Mol Cell Neurosci 2023; 125:103858. [PMID: 37172922 DOI: 10.1016/j.mcn.2023.103858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 05/05/2023] [Accepted: 05/05/2023] [Indexed: 05/15/2023] Open
Abstract
High turnover rates of synaptic proteins imply that synapses constantly need to replace their constituent building blocks. This requires sophisticated supply chains and potentially exposes synapses to shortages as they compete for limited resources. Interestingly, competition in neurons has been observed at different scales. Whether it is competition of receptors for binding sites inside a single synapse or synapses fighting for resources to grow. Here we review the implications of such competition for synaptic function and plasticity. We identify multiple mechanisms that synapses use to safeguard themselves against supply shortages and identify a fundamental neurologistic trade-off governing the sizes of reserve pools of essential synaptic building blocks.
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Affiliation(s)
- Anne-Sophie Hafner
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands.
| | - Jochen Triesch
- Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany; Goethe University, Frankfurt am Main, Germany
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44
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Fukuda N, Fukuda T, Percipalle P, Oda K, Takei N, Czaplinski K, Touhara K, Yoshihara Y, Sasaoka T. Axonal mRNA binding of hnRNP A/B is crucial for axon targeting and maturation of olfactory sensory neurons. Cell Rep 2023; 42:112398. [PMID: 37083330 DOI: 10.1016/j.celrep.2023.112398] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 01/26/2023] [Accepted: 03/29/2023] [Indexed: 04/22/2023] Open
Abstract
Spatiotemporal control of gene expression is important for neural development and function. Here, we show that heterogeneous nuclear ribonucleoprotein (hnRNP) A/B is highly expressed in developing olfactory sensory neurons (OSNs), and its knockout results in reduction in mature OSNs and aberrant targeting of OSN axons to the olfactory bulb. RNA immunoprecipitation analysis reveals that hnRNP A/B binds to a group of mRNAs that are highly related to axon projections and synapse assembly. Approximately 11% of the identified hnRNP A/B targets, including Pcdha and Ncam2, encode cell adhesion molecules. In Hnrnpab knockout mice, PCDHA and NCAM2 levels are significantly reduced at the axon terminals of OSNs. Furthermore, deletion of the hnRNP A/B-recognition motif in the 3' UTR of Pcdha leads to impaired PCDHA expression at the OSN axon terminals. Therefore, we propose that hnRNP A/B facilitates OSN maturation and axon projection by regulating the local expression of its target genes at axon terminals.
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Affiliation(s)
- Nanaho Fukuda
- Brain Research Institute, Niigata University, Niigata 951-8585, Japan; Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma 630-0192, Japan.
| | - Tomoyuki Fukuda
- Niigata University Graduate School of Medical and Dental Science, Niigata 951-8510, Japan
| | - Piergiorgio Percipalle
- Science Division, Biology Program, New York University Abu Dhabi, Abu Dhabi 129188, UAE; Department of Molecular Bioscience, The Wenner-Gren Institute, Stockholm University, 106 91 Stockholm, Sweden
| | - Kanako Oda
- Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | - Nobuyuki Takei
- Brain Research Institute, Niigata University, Niigata 951-8585, Japan
| | | | - Kazushige Touhara
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | | | - Toshikuni Sasaoka
- Brain Research Institute, Niigata University, Niigata 951-8585, Japan
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45
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Piol D, Robberechts T, Da Cruz S. Lost in local translation: TDP-43 and FUS in axonal/neuromuscular junction maintenance and dysregulation in amyotrophic lateral sclerosis. Neuron 2023; 111:1355-1380. [PMID: 36963381 DOI: 10.1016/j.neuron.2023.02.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/21/2022] [Accepted: 02/16/2023] [Indexed: 03/26/2023]
Abstract
Key early features of amyotrophic lateral sclerosis (ALS) are denervation of neuromuscular junctions and axonal degeneration. Motor neuron homeostasis relies on local translation through controlled regulation of axonal mRNA localization, transport, and stability. Yet the composition of the local transcriptome, translatome (mRNAs locally translated), and proteome during health and disease remains largely unexplored. This review covers recent discoveries on axonal translation as a critical mechanism for neuronal maintenance/survival. We focus on two RNA binding proteins, transactive response DNA binding protein-43 (TDP-43) and fused in sarcoma (FUS), whose mutations cause ALS and frontotemporal dementia (FTD). Emerging evidence points to their essential role in the maintenance of axons and synapses, including mRNA localization, transport, and local translation, and whose dysfunction may contribute to ALS. Finally, we describe recent advances in omics-based approaches mapping compartment-specific local RNA and protein compositions, which will be invaluable to elucidate fundamental local processes and identify key targets for therapy development.
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Affiliation(s)
- Diana Piol
- VIB-KU Leuven Center for Brain and Disease Research, Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Belgium
| | - Tessa Robberechts
- VIB-KU Leuven Center for Brain and Disease Research, Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Belgium
| | - Sandrine Da Cruz
- VIB-KU Leuven Center for Brain and Disease Research, Department of Neurosciences, KU Leuven, Leuven Brain Institute, Leuven, Belgium.
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46
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Sun C, Schuman E. A multi-omics view of neuronal subcellular protein synthesis. Curr Opin Neurobiol 2023; 80:102705. [PMID: 36913750 DOI: 10.1016/j.conb.2023.102705] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 03/13/2023]
Abstract
While it has long been known that protein synthesis is necessary for long-term memory in the brain, the logistics of neuronal protein synthesis is complicated by the extensive subcellular compartmentalization of the neuron. Local protein synthesis solves many of the logistic problems posed by the extreme complexity of dendritic and axonal arbors and the huge number of synapses. Here we review recent multi-omic and quantitative studies that elaborate a systems view of decentralized neuronal protein synthesis. We highlight recent insights from the transcriptomic, translatomic, and proteomic levels, discuss the nuanced logic of local protein synthesis for different protein features, and list the missing information needed to build a comprehensive logistic model for neuronal protein supply.
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Affiliation(s)
- Chao Sun
- Max Planck Institute for Brain Research, Frankfurt, Germany; Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Denmark; Aarhus University, Department of Molecular Biology and Genetics, Universitetsbyen 81, 8000 Aarhus C, Denmark. https://twitter.com/LukeChaoSun
| | - Erin Schuman
- Max Planck Institute for Brain Research, Frankfurt, Germany.
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Gouveia Roque C, Chung KM, McCurdy EP, Jagannathan R, Randolph LK, Herline-Killian K, Baleriola J, Hengst U. CREB3L2-ATF4 heterodimerization defines a transcriptional hub of Alzheimer's disease gene expression linked to neuropathology. SCIENCE ADVANCES 2023; 9:eadd2671. [PMID: 36867706 PMCID: PMC9984184 DOI: 10.1126/sciadv.add2671] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Gene expression is changed by disease, but how these molecular responses arise and contribute to pathophysiology remains less understood. We discover that β-amyloid, a trigger of Alzheimer's disease (AD), promotes the formation of pathological CREB3L2-ATF4 transcription factor heterodimers in neurons. Through a multilevel approach based on AD datasets and a novel chemogenetic method that resolves the genomic binding profile of dimeric transcription factors (ChIPmera), we find that CREB3L2-ATF4 activates a transcription network that interacts with roughly half of the genes differentially expressed in AD, including subsets associated with β-amyloid and tau neuropathologies. CREB3L2-ATF4 activation drives tau hyperphosphorylation and secretion in neurons, in addition to misregulating the retromer, an endosomal complex linked to AD pathogenesis. We further provide evidence for increased heterodimer signaling in AD brain and identify dovitinib as a candidate molecule for normalizing β-amyloid-mediated transcriptional responses. The findings overall reveal differential transcription factor dimerization as a mechanism linking disease stimuli to the development of pathogenic cellular states.
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Affiliation(s)
- Cláudio Gouveia Roque
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Kyung Min Chung
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Ethan P. McCurdy
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Radhika Jagannathan
- Division of Aging and Dementia, Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Lisa K. Randolph
- Doctoral Program in Neurobiology and Behavior, Columbia University, New York, NY, USA
| | - Krystal Herline-Killian
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jimena Baleriola
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- IKERBASQUE Basque Foundation for Science, Bilbao, Spain
- Department of Cell Biology and Histology, University of the Basque Country, Leioa, Spain
| | - Ulrich Hengst
- The Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
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48
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Massively parallel identification of mRNA localization elements in primary cortical neurons. Nat Neurosci 2023; 26:394-405. [PMID: 36646877 PMCID: PMC9991926 DOI: 10.1038/s41593-022-01243-x] [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: 12/14/2021] [Accepted: 12/01/2022] [Indexed: 01/18/2023]
Abstract
Cells adopt highly polarized shapes and form distinct subcellular compartments in many cases due to the localization of many mRNAs to specific areas, where they are translated into proteins with local functions. This mRNA localization is mediated by specific cis-regulatory elements in mRNAs, commonly called 'zipcodes'. Although there are hundreds of localized mRNAs, only a few zipcodes have been characterized. Here we describe a novel neuronal zipcode identification protocol (N-zip) that can identify zipcodes across hundreds of 3' untranslated regions. This approach combines a method of separating the principal subcellular compartments of neurons-cell bodies and neurites-with a massively parallel reporter assay. N-zip identifies the let-7 binding site and (AU)n motif as de novo zipcodes in mouse primary cortical neurons. Our analysis also provides, to our knowledge, the first demonstration of an miRNA affecting mRNA localization and suggests a strategy for detecting many more zipcodes.
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49
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Jung J, Ohk J, Kim H, Holt CE, Park HJ, Jung H. mRNA transport, translation, and decay in adult mammalian central nervous system axons. Neuron 2023; 111:650-668.e4. [PMID: 36584679 DOI: 10.1016/j.neuron.2022.12.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 08/31/2022] [Accepted: 12/08/2022] [Indexed: 12/30/2022]
Abstract
Localized mRNA translation regulates synapse function and axon maintenance, but how compartment-specific mRNA repertoires are regulated is largely unknown. We developed an axonal transcriptome capture method that allows deep sequencing of metabolically labeled mRNAs from retinal ganglion cell axon terminals in mouse. Comparing axonal-to-somal transcriptomes and axonal translatome-to-transcriptome enables genome-wide visualization of mRNA transport and translation and unveils potential regulators tuned to each process. FMRP and TDP-43 stand out as key regulators of transport, and experiments in Fmr1 knockout mice validate FMRP's role in the axonal transportation of synapse-related mRNAs. Pulse-and-chase experiments enable genome-wide assessment of mRNA stability in axons and reveal a strong coupling between mRNA translation and decay. Measuring the absolute mRNA abundance per axon terminal shows that the adult axonal transcriptome is stably maintained by persistent transport. Our datasets provide a rich resource for unique insights into RNA-based mechanisms in maintaining presynaptic structure and function in vivo.
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Affiliation(s)
- Jane Jung
- Department of Anatomy, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Jiyeon Ohk
- Department of Anatomy, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Hyeyoung Kim
- Department of Anatomy, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Hyun Jung Park
- Samsung Genome Institute, Samsung Medical Center, Seoul, Republic of Korea.
| | - Hosung Jung
- Department of Anatomy, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.
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50
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Abstract
The midbrain dopamine (mDA) system is composed of molecularly and functionally distinct neuron subtypes that mediate specific behaviours and are linked to various brain diseases. Considerable progress has been made in identifying mDA neuron subtypes, and recent work has begun to unveil how these neuronal subtypes develop and organize into functional brain structures. This progress is important for further understanding the disparate physiological functions of mDA neurons and their selective vulnerability in disease, and will ultimately accelerate therapy development. This Review discusses recent advances in our understanding of molecularly defined mDA neuron subtypes and their circuits, ranging from early developmental events, such as neuron migration and axon guidance, to their wiring and function, and future implications for therapeutic strategies.
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