1
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Lu YM, Yan S, Ti SC, Zheng C. Editing of endogenous tubulins reveals varying effects of tubulin posttranslational modifications on axonal growth and regeneration. eLife 2024; 13:RP94583. [PMID: 38949652 PMCID: PMC11216746 DOI: 10.7554/elife.94583] [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: 07/02/2024] Open
Abstract
Tubulin posttranslational modifications (PTMs) modulate the dynamic properties of microtubules and their interactions with other proteins. However, the effects of tubulin PTMs were often revealed indirectly through the deletion of modifying enzymes or the overexpression of tubulin mutants. In this study, we directly edited the endogenous tubulin loci to install PTM-mimicking or -disabling mutations and studied their effects on microtubule stability, neurite outgrowth, axonal regeneration, cargo transport, and sensory functions in the touch receptor neurons of Caenorhabditis elegans. We found that the status of β-tubulin S172 phosphorylation and K252 acetylation strongly affected microtubule dynamics, neurite growth, and regeneration, whereas α-tubulin K40 acetylation had little influence. Polyglutamylation and detyrosination in the tubulin C-terminal tail had more subtle effects on microtubule stability likely by modulating the interaction with kinesin-13. Overall, our study systematically assessed and compared several tubulin PTMs for their impacts on neuronal differentiation and regeneration and established an in vivo platform to test the function of tubulin PTMs in neurons.
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Affiliation(s)
- Yu-Ming Lu
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SARHong KongChina
| | - Shan Yan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong KongHong KongChina
| | - Shih-Chieh Ti
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong KongHong KongChina
| | - Chaogu Zheng
- School of Biological Sciences, Faculty of Science, The University of Hong Kong, Hong Kong SARHong KongChina
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2
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Vasudevan A, Koushika SP. Physical presence of chemical synapses is necessary for turning behavior of anterograde synaptic vesicles at the branch point of PLM neurons in C. elegans. MICROPUBLICATION BIOLOGY 2024; 2024. [PMID: 38989012 PMCID: PMC11234195 DOI: 10.17912/micropub.biology.001204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/12/2024]
Abstract
Neurons exhibit complex branched axonal morphologies in both vertebrate and invertebrate systems, and show heterogeneity in the distribution of synaptic cargo across multiple synapses. It is possible that differences in transport across multiple branches contribute to the heterogeneity in cargo distribution across multiple synapses. However, the regulation of transport at axonal branch points is not well understood. We demonstrate that branch-specific transport of synaptic vesicles is dependent on the existence of a connection between the branch and synapses. The loss of this connection causes an immediate decrease in branch-specific transport of synaptic vesicles in the PLM neuron of C. elegans .
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Affiliation(s)
- Amruta Vasudevan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Sandhya P Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
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3
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Romussi S, Giunti S, Andersen N, De Rosa MJ. C. elegans: a prominent platform for modeling and drug screening in neurological disorders. Expert Opin Drug Discov 2024; 19:565-585. [PMID: 38509691 DOI: 10.1080/17460441.2024.2329103] [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: 11/13/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024]
Abstract
INTRODUCTION Human neurodevelopmental and neurodegenerative diseases (NDevDs and NDegDs, respectively) encompass a broad spectrum of disorders affecting the nervous system with an increasing incidence. In this context, the nematode C. elegans, has emerged as a benchmark model for biological research, especially in the field of neuroscience. AREAS COVERED The authors highlight the numerous advantages of this tiny worm as a model for exploring nervous system pathologies and as a platform for drug discovery. There is a particular focus given to describing the existing models of C. elegans for the study of NDevDs and NDegDs. Specifically, the authors underscore their strong applicability in preclinical drug development. Furthermore, they place particular emphasis on detailing the common techniques employed to explore the nervous system in both healthy and diseased states. EXPERT OPINION Drug discovery constitutes a long and expensive process. The incorporation of invertebrate models, such as C. elegans, stands as an exemplary strategy for mitigating costs and expediting timelines. The utilization of C. elegans as a platform to replicate nervous system pathologies and conduct high-throughput automated assays in the initial phases of drug discovery is pivotal for rendering therapeutic options more attainable and cost-effective.
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Affiliation(s)
- Stefano Romussi
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
| | - Sebastián Giunti
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - Natalia Andersen
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
| | - María José De Rosa
- Laboratorio de Neurobiología de Invertebrados, Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), UNS-CONICET, Bahía Blanca, Argentina
- Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur (UNS), Bahía Blanca, Argentina
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4
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Gujar MR, Gao Y, Teng X, Deng Q, Lin KY, Tan YS, Toyama Y, Wang H. Golgi-dependent reactivation and regeneration of Drosophila quiescent neural stem cells. Dev Cell 2023; 58:1933-1949.e5. [PMID: 37567172 DOI: 10.1016/j.devcel.2023.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 04/26/2023] [Accepted: 07/17/2023] [Indexed: 08/13/2023]
Abstract
The ability of stem cells to switch between quiescent and proliferative states is crucial for maintaining tissue homeostasis and regeneration. In Drosophila, quiescent neural stem cells (qNSCs) extend a primary protrusion, a hallmark of qNSCs. Here, we have found that qNSC protrusions can be regenerated upon injury. This regeneration process relies on the Golgi apparatus that acts as the major acentrosomal microtubule-organizing center in qNSCs. A Golgi-resident GTPase Arf1 and its guanine nucleotide exchange factor Sec71 promote NSC reactivation and regeneration via the regulation of microtubule growth. Arf1 physically associates with its new effector mini spindles (Msps)/XMAP215, a microtubule polymerase. Finally, Arf1 functions upstream of Msps to target the cell adhesion molecule E-cadherin to NSC-neuropil contact sites during NSC reactivation. Our findings have established Drosophila qNSCs as a regeneration model and identified Arf1/Sec71-Msps pathway in the regulation of microtubule growth and NSC reactivation.
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Affiliation(s)
- Mahekta R Gujar
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Yang Gao
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Xiang Teng
- Mechanobiology Institute, Level 5, T-lab Building, 5A Engineering Drive 1, Singapore 117411, Singapore
| | - Qiannan Deng
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Kun-Yang Lin
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Ye Sing Tan
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore
| | - Yusuke Toyama
- Mechanobiology Institute, Level 5, T-lab Building, 5A Engineering Drive 1, Singapore 117411, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Hongyan Wang
- Neuroscience & Behavioral Disorders Programme, Duke-NUS Medical School, 8 College Road, Singapore 169857, Singapore; Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Integrative Sciences and Engineering Programme, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
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5
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Khazma T, Grossman A, Guez-Haddad J, Feng C, Dabas H, Sain R, Weitman M, Zalk R, Isupov MN, Hammarlund M, Hons M, Opatowsky Y. Structure-function analysis of ceTIR-1/hSARM1 explains the lack of Wallerian axonal degeneration in C. elegans. Cell Rep 2023; 42:113026. [PMID: 37635352 PMCID: PMC10675840 DOI: 10.1016/j.celrep.2023.113026] [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: 01/07/2023] [Revised: 06/05/2023] [Accepted: 08/09/2023] [Indexed: 08/29/2023] Open
Abstract
Wallerian axonal degeneration (WD) does not occur in the nematode C. elegans, in contrast to other model animals. However, WD depends on the NADase activity of SARM1, a protein that is also expressed in C. elegans (ceSARM/ceTIR-1). We hypothesized that differences in SARM between species might exist and account for the divergence in WD. We first show that expression of the human (h)SARM1, but not ceTIR-1, in C. elegans neurons is sufficient to confer axon degeneration after nerve injury. Next, we determined the cryoelectron microscopy structure of ceTIR-1 and found that, unlike hSARM1, which exists as an auto-inhibited ring octamer, ceTIR-1 forms a readily active 9-mer. Enzymatically, the NADase activity of ceTIR-1 is substantially weaker (10-fold higher Km) than that of hSARM1, and even when fully active, it falls short of consuming all cellular NAD+. Our experiments provide insight into the molecular mechanisms and evolution of SARM orthologs and WD across species.
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Affiliation(s)
- Tami Khazma
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Atira Grossman
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Julia Guez-Haddad
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Chengye Feng
- Departments of Neuroscience and Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Hadas Dabas
- Departments of Neuroscience and Genetics, Yale School of Medicine, New Haven, CT, USA
| | - Radhika Sain
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Michal Weitman
- Department of Chemistry, Bar-Ilan University, Ramat Gan, Israel
| | - Ran Zalk
- Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Michail N Isupov
- Henry Wellcome Building for Biocatalysis, Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Marc Hammarlund
- Departments of Neuroscience and Genetics, Yale School of Medicine, New Haven, CT, USA.
| | - Michael Hons
- European Molecular Biology Laboratory, Grenoble, France.
| | - Yarden Opatowsky
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.
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6
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Sun H, Hobert O. Temporal transitions in the postembryonic nervous system of the nematode Caenorhabditis elegans: Recent insights and open questions. Semin Cell Dev Biol 2023; 142:67-80. [PMID: 35688774 DOI: 10.1016/j.semcdb.2022.05.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/27/2022] [Accepted: 05/27/2022] [Indexed: 10/18/2022]
Abstract
After the generation, differentiation and integration into functional circuitry, post-mitotic neurons continue to change certain phenotypic properties throughout postnatal juvenile stages until an animal has reached a fully mature state in adulthood. We will discuss such changes in the context of the nervous system of the nematode C. elegans, focusing on recent descriptions of anatomical and molecular changes that accompany postembryonic maturation of neurons. We summarize the characterization of genetic timer mechanisms that control these temporal transitions or maturational changes, and discuss that many but not all of these transitions relate to sexual maturation of the animal. We describe how temporal, spatial and sex-determination pathways are intertwined to sculpt the emergence of cell-type specific maturation events. Finally, we lay out several unresolved questions that should be addressed to move the field forward, both in C. elegans and in vertebrates.
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Affiliation(s)
- Haosheng Sun
- Department of Cell, Developmental, and Integrative Biology. University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, New York, USA
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7
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Wang F, Ruppell KT, Zhou S, Qu Y, Gong J, Shang Y, Wu J, Liu X, Diao W, Li Y, Xiang Y. Gliotransmission and adenosine signaling promote axon regeneration. Dev Cell 2023; 58:660-676.e7. [PMID: 37028426 PMCID: PMC10173126 DOI: 10.1016/j.devcel.2023.03.007] [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: 01/04/2022] [Revised: 11/18/2022] [Accepted: 03/08/2023] [Indexed: 04/08/2023]
Abstract
How glia control axon regeneration remains incompletely understood. Here, we investigate glial regulation of regenerative ability differences of closely related Drosophila larval sensory neuron subtypes. Axotomy elicits Ca2+ signals in ensheathing glia, which activates regenerative neurons through the gliotransmitter adenosine and mounts axon regenerative programs. However, non-regenerative neurons do not respond to glial stimulation or adenosine. Such neuronal subtype-specific responses result from specific expressions of adenosine receptors in regenerative neurons. Disrupting gliotransmission impedes axon regeneration of regenerative neurons, and ectopic adenosine receptor expression in non-regenerative neurons suffices to activate regenerative programs and induce axon regeneration. Furthermore, stimulating gliotransmission or activating the mammalian ortholog of Drosophila adenosine receptors in retinal ganglion cells (RGCs) promotes axon regrowth after optic nerve crush in adult mice. Altogether, our findings demonstrate that gliotransmission orchestrates neuronal subtype-specific axon regeneration in Drosophila and suggest that targeting gliotransmission or adenosine signaling is a strategy for mammalian central nervous system repair.
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Affiliation(s)
- Fei Wang
- Department of Neurobiology, Program of Neuroscience, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Kendra Takle Ruppell
- Department of Neurobiology, Program of Neuroscience, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Songlin Zhou
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China; Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Yun Qu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Jiaxin Gong
- Department of Neurobiology, Program of Neuroscience, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Ye Shang
- Department of Neurobiology, Program of Neuroscience, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA
| | - Jinglin Wu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xin Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Wenlin Diao
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yi Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China; The National Clinical Research Center for Aging and Medicine, Fudan University, Shanghai, China.
| | - Yang Xiang
- Department of Neurobiology, Program of Neuroscience, University of Massachusetts Chan Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
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8
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Liu X, Zhao Y, Zou W. Molecular mechanisms of neurite regeneration and repair: insights from C. elegans and Drosophila. CELL REGENERATION (LONDON, ENGLAND) 2023; 12:12. [PMID: 37005942 PMCID: PMC10067779 DOI: 10.1186/s13619-022-00155-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 12/01/2022] [Indexed: 04/04/2023]
Abstract
The difficulties of injured and degenerated neurons to regenerate neurites and regain functions are more significant than in other body tissues, making neurodegenerative and related diseases hard to cure. Uncovering the secrets of neural regeneration and how this process may be inhibited after injury will provide insights into novel management and potential treatments for these diseases. Caenorhabditis elegans and Drosophila melanogaster are two of the most widely used and well-established model organisms endowed with advantages in genetic manipulation and live imaging to explore this fundamental question about neural regeneration. Here, we review the classical models and techniques, and the involvement and cooperation of subcellular structures during neurite regeneration using these two organisms. Finally, we list several important open questions that we look forward to inspiring future research.
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Affiliation(s)
- Xiaofan Liu
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou, China
| | - Yuqing Zhao
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou, China
- Institute of Zhejiang University and University of Edinburgh, Jiaxing, China
| | - Wei Zou
- The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, China.
- Institute of Translational Medicine, Zhejiang University, Hangzhou, China.
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9
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Zhao P, Mondal S, Martin C, DuPlissis A, Chizari S, Ma KY, Maiya R, Messing RO, Jiang N, Ben-Yakar A. Femtosecond laser microdissection for isolation of regenerating C. elegans neurons for single-cell RNA sequencing. Nat Methods 2023; 20:590-599. [PMID: 36928074 DOI: 10.1038/s41592-023-01804-3] [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: 12/30/2020] [Accepted: 01/26/2023] [Indexed: 03/18/2023]
Abstract
Our understanding of nerve regeneration can be enhanced by delineating its underlying molecular activities at single-neuron resolution in model organisms such as Caenorhabditis elegans. Existing cell isolation techniques cannot isolate neurons with specific regeneration phenotypes from C. elegans. We present femtosecond laser microdissection (fs-LM), a single-cell isolation method that dissects specific cells directly from living tissue by leveraging the micrometer-scale precision of fs-laser ablation. We show that fs-LM facilitates sensitive and specific gene expression profiling by single-cell RNA sequencing (scRNA-seq), while mitigating the stress-related transcriptional artifacts induced by tissue dissociation. scRNA-seq of fs-LM isolated regenerating neurons revealed transcriptional programs that are correlated with either successful or failed regeneration in wild-type and dlk-1 (0) animals, respectively. This method also allowed studying heterogeneity displayed by the same type of neuron and found gene modules with expression patterns correlated with axon regrowth rate. Our results establish fs-LM as a spatially resolved single-cell isolation method for phenotype-to-genotype mapping.
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Affiliation(s)
- Peisen Zhao
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Sudip Mondal
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Chris Martin
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Andrew DuPlissis
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Shahab Chizari
- Deparment of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Ke-Yue Ma
- Interdisciplinary Life Sciences Graduate Programs, The University of Texas at Austin, Austin, TX, USA
| | - Rajani Maiya
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
- Institute of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Physiology, LSU Health Sciences Center, New Orleans, LA, USA
| | - Robert O Messing
- Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
- Institute of Neuroscience, The University of Texas at Austin, Austin, TX, USA
| | - Ning Jiang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
- Deparment of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Interdisciplinary Life Sciences Graduate Programs, The University of Texas at Austin, Austin, TX, USA
| | - Adela Ben-Yakar
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX, USA.
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.
- Institute of Neuroscience, The University of Texas at Austin, Austin, TX, USA.
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10
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Zhao Y, Hua X, Bian Q, Wang D. Nanoplastic Exposure at Predicted Environmental Concentrations Induces Activation of Germline Ephrin Signal Associated with Toxicity Formation in the Caenorhabditis elegans Offspring. TOXICS 2022; 10:toxics10110699. [PMID: 36422907 PMCID: PMC9696181 DOI: 10.3390/toxics10110699] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/15/2022] [Accepted: 11/16/2022] [Indexed: 05/04/2023]
Abstract
In nematode Caenorhabditis elegans, exposure to polystyrene nanoparticles (PS-NPs) at predicted environmental concentrations can cause induction of transgenerational toxicity. However, the underlying mechanisms for toxicity formation of PS-NP in the offspring remain largely unknown. In this study, based on high-throughput sequencing, Ephrin ligand EFN-3 was identified as a target of KSR-1/2 (two kinase suppressors of Ras) in the germline during the control of transgenerational PS-NP toxicity. At parental generation (P0-G), exposure to 0.1-10 μg/L PS-NP caused the increase in expression of germline efn-3, and this increase in germline efn-3 expression could be further detected in the offspring, such as F1-G and F2-G. Germline RNAi of efn-3 caused a resistance to transgenerational PS-NP toxicity, suggesting that the activation of germline EFN-3 at P0-G mediated transgenerational PS-NP toxicity. In the offspring, Ephrin receptor VAB-1 was further activated by the increased EFN-3 caused by PS-NP exposure at P0-G, and RNAi of vab-1 also resulted in resistance to transgenerational PS-NP toxicity. VAB-1 acted in both the neurons and the germline to control toxicity of PS-NP in the offspring. In the neurons, VAB-1 regulated PS-NP toxicity by suppressing expressions of DBL-1, JNK-1, MPK-1, and GLB-10. In the germline, VAB-1 regulated PS-NP toxicity by increasing NDK-1 and LIN-23 expressions and decreasing EGL-1 expression. Therefore, germline Ephrin ligand EFN-3 and its receptor VAB-1 acted together to mediate the formation of transgenerational PS-NP toxicity. Our data highlight the important role of activation in germline Ephrin signals in mediating transgenerational toxicity of nanoplastics at predicted environmental concentrations in organisms.
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Affiliation(s)
- Yue Zhao
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
- Institute of Toxicology and Risk Assessment, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
| | - Xin Hua
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
| | - Qian Bian
- Institute of Toxicology and Risk Assessment, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China
- Correspondence: (Q.B.); (D.W.)
| | - Dayong Wang
- Key Laboratory of Environmental Medicine Engineering in Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
- Shenzhen Ruipuxun Academy for Stem Cell & Regenerative Medicine, Shenzhen 518122, China
- Correspondence: (Q.B.); (D.W.)
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11
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Intrinsic heterogeneity in axon regeneration. Biochem Soc Trans 2022; 50:1753-1762. [DOI: 10.1042/bst20220624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
Abstract
The nervous system is composed of a variety of neurons and glial cells with different morphology and functions. In the mammalian peripheral nervous system (PNS) or the lower vertebrate central nervous system (CNS), most neurons can regenerate extensively after axotomy, while the neurons in the mammalian CNS possess only limited regenerative ability. This heterogeneity is common within and across species. The studies about the transcriptomes after nerve injury in different animal models have revealed a series of molecular and cellular events that occurred in neurons after axotomy. However, responses of various types of neurons located in different positions of individuals were different remarkably. Thus, researchers aim to find the key factors that are conducive to regeneration, so as to provide the molecular basis for solving the regeneration difficulties after CNS injury. Here we review the heterogeneity of axonal regeneration among different cell subtypes in different animal models or the same organ, emphasizing the importance of comparative studies within and across species.
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12
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Functional Insights into Protein Kinase A (PKA) Signaling from C. elegans. LIFE (BASEL, SWITZERLAND) 2022; 12:life12111878. [PMID: 36431013 PMCID: PMC9692727 DOI: 10.3390/life12111878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/04/2022] [Accepted: 11/11/2022] [Indexed: 11/16/2022]
Abstract
Protein kinase A (PKA), which regulates a diverse set of biological functions downstream of cyclic AMP (cAMP), is a tetramer consisting of two catalytic subunits (PKA-C) and two regulatory subunits (PKA-R). When cAMP binds the PKA-R subunits, the PKA-C subunits are released and interact with downstream effectors. In Caenorhabditis elegans (C. elegans), PKA-C and PKA-R are encoded by kin-1 and kin-2, respectively. This review focuses on the contributions of work in C. elegans to our understanding of the many roles of PKA, including contractility and oocyte maturation in the reproductive system, lipid metabolism, physiology, mitochondrial function and lifespan, and a wide variety of behaviors. C. elegans provides a powerful genetic platform for understanding how this kinase can regulate an astounding variety of physiological responses.
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13
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Noristani HN. Intrinsic regulation of axon regeneration after spinal cord injury: Recent advances and remaining challenges. Exp Neurol 2022; 357:114198. [DOI: 10.1016/j.expneurol.2022.114198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/20/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022]
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14
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Juanez K, Ghose P. Repurposing the Killing Machine: Non-canonical Roles of the Cell Death Apparatus in Caenorhabditis elegans Neurons. Front Cell Dev Biol 2022; 10:825124. [PMID: 35237604 PMCID: PMC8882910 DOI: 10.3389/fcell.2022.825124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/31/2022] [Indexed: 12/29/2022] Open
Abstract
Here we highlight the increasingly divergent functions of the Caenorhabditis elegans cell elimination genes in the nervous system, beyond their well-documented roles in cell dismantling and removal. We describe relevant background on the C. elegans nervous system together with the apoptotic cell death and engulfment pathways, highlighting pioneering work in C. elegans. We discuss in detail the unexpected, atypical roles of cell elimination genes in various aspects of neuronal development, response and function. This includes the regulation of cell division, pruning, axon regeneration, and behavioral outputs. We share our outlook on expanding our thinking as to what cell elimination genes can do and noting their versatility. We speculate on the existence of novel genes downstream and upstream of the canonical cell death pathways relevant to neuronal biology. We also propose future directions emphasizing the exploration of the roles of cell death genes in pruning and guidance during embryonic development.
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15
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Guo B, Qi M, Huang S, Zhuo R, Zhang W, Zhang Y, Xu M, Liu M, Guan T, Liu Y. Cadherin-12 Regulates Neurite Outgrowth Through the PKA/Rac1/Cdc42 Pathway in Cortical Neurons. Front Cell Dev Biol 2021; 9:768970. [PMID: 34820384 PMCID: PMC8606577 DOI: 10.3389/fcell.2021.768970] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/11/2021] [Indexed: 12/22/2022] Open
Abstract
Cadherins play an important role in tissue homeostasis, as they are responsible for cell-cell adhesion during embryogenesis, tissue morphogenesis, and differentiation. In this study, we identified Cadherin-12 (CDH12), which encodes a type II classical cadherin, as a gene that promotes neurite outgrowth in an in vitro model of neurons with differentiated intrinsic growth ability. First, the effects of CDH12 on neurons were evaluated via RNA interference, and the results indicated that the knockdown of CDH12 expression restrained the axon extension of E18 neurons. The transcriptome profile of neurons with or without siCDH12 treatment revealed a set of pathways positively correlated with the effect of CDH12 on neurite outgrowth. We further revealed that CDH12 affected Rac1/Cdc42 phosphorylation in a PKA-dependent manner after testing using H-89 and 8-Bromo-cAMP sodium salt. Moreover, we investigated the expression of CDH12 in the brain, spinal cord, and dorsal root ganglia (DRG) during development using immunofluorescence staining. After that, we explored the effects of CDH12 on neurite outgrowth in vivo. A zebrafish model of CDH12 knockdown was established using the NgAgo-gDNA system, and the vital role of CDH12 in peripheral neurogenesis was determined. In summary, our study is the first to report the effect of CDH12 on axonal extension in vitro and in vivo, and we provide a preliminary explanation for this mechanism.
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Affiliation(s)
- Beibei Guo
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Mengwei Qi
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Shuai Huang
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Run Zhuo
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Wenxue Zhang
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yufang Zhang
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Man Xu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Tuchen Guan
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu Province and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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16
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Kulkarni SS, Sabharwal V, Sheoran S, Basu A, Matsumoto K, Hisamoto N, Ghosh-Roy A, Koushika SP. UNC-16 alters DLK-1 localization and negatively regulates actin and microtubule dynamics in Caenorhabditis elegans regenerating neurons. Genetics 2021; 219:6359182. [PMID: 34740241 DOI: 10.1093/genetics/iyab139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/13/2021] [Indexed: 11/13/2022] Open
Abstract
Neuronal regeneration after injury depends on the intrinsic growth potential of neurons. Our study shows that UNC-16, a Caenorhabditis elegans JIP3 homolog, inhibits axonal regeneration by regulating initiation and rate of regrowth. This occurs through the inhibition of the regeneration-promoting activity of the long isoform of DLK-1 and independently of the inhibitory short isoform of DLK-1. We show that UNC-16 promotes DLK-1 punctate localization in a concentration-dependent manner limiting the availability of the long isoform of DLK-1 at the cut site, minutes after injury. UNC-16 negatively regulates actin dynamics through DLK-1 and microtubule dynamics partially via DLK-1. We show that post-injury cytoskeletal dynamics in unc-16 mutants are also partially dependent on CEBP-1. The faster regeneration seen in unc-16 mutants does not lead to functional recovery. Our data suggest that the inhibitory control by UNC-16 and the short isoform of DLK-1 balances the intrinsic growth-promoting function of the long isoform of DLK-1 in vivo. We propose a model where UNC-16's inhibitory role in regeneration occurs through both a tight temporal and spatial control of DLK-1 and cytoskeletal dynamics.
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Affiliation(s)
- Sucheta S Kulkarni
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, 560065, India
| | - Vidur Sabharwal
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Seema Sheoran
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, 560065, India
| | - Atrayee Basu
- Department of Biotechnology National Brain Research Centre, Manesar 122052, India
| | - Kunihiro Matsumoto
- Department of Molecular Biology, Nagoya University, Nagoya 4648601, Japan
| | - Naoki Hisamoto
- Department of Molecular Biology, Nagoya University, Nagoya 4648601, Japan
| | - Anindya Ghosh-Roy
- Department of Biotechnology National Brain Research Centre, Manesar 122052, India
| | - Sandhya P Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
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17
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Piggott CA, Wu Z, Nurrish S, Xu S, Kaplan JM, Chisholm AD, Jin Y. Caenorhabditis elegans junctophilin has tissue-specific functions and regulates neurotransmission with extended-synaptotagmin. Genetics 2021; 218:iyab063. [PMID: 33871019 PMCID: PMC8864756 DOI: 10.1093/genetics/iyab063] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 04/12/2021] [Indexed: 02/06/2023] Open
Abstract
The junctophilin family of proteins tether together plasma membrane (PM) and endoplasmic reticulum (ER) membranes, and couple PM- and ER-localized calcium channels. Understanding in vivo functions of junctophilins is of great interest for dissecting the physiological roles of ER-PM contact sites. Here, we show that the sole Caenorhabditis elegans junctophilin JPH-1 localizes to discrete membrane contact sites in neurons and muscles and has important tissue-specific functions. jph-1 null mutants display slow growth and development due to weaker contraction of pharyngeal muscles, leading to reduced feeding. In the body wall muscle, JPH-1 colocalizes with the PM-localized EGL-19 voltage-gated calcium channel and ER-localized UNC-68 RyR calcium channel, and is required for animal movement. In neurons, JPH-1 colocalizes with the membrane contact site protein Extended-SYnaptoTagmin 2 (ESYT-2) in the soma, and is present near presynaptic release sites. Interestingly, jph-1 and esyt-2 null mutants display mutual suppression in their response to aldicarb, suggesting that JPH-1 and ESYT-2 have antagonistic roles in neuromuscular synaptic transmission. Additionally, we find an unexpected cell nonautonomous effect of jph-1 in axon regrowth after injury. Genetic double mutant analysis suggests that jph-1 functions in overlapping pathways with two PM-localized voltage-gated calcium channels, egl-19 and unc-2, and with unc-68 for animal health and development. Finally, we show that jph-1 regulates the colocalization of EGL-19 and UNC-68 and that unc-68 is required for JPH-1 localization to ER-PM puncta. Our data demonstrate important roles for junctophilin in cellular physiology, and also provide insights into how junctophilin functions together with other calcium channels in vivo.
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Affiliation(s)
- Christopher A Piggott
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Zilu Wu
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Stephen Nurrish
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Suhong Xu
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Joshua M Kaplan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
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18
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Tzouanas CN, Kim S, Badhiwala KN, Avants BW, Robinson JT. Hydra vulgaris shows stable responses to thermal stimulation despite large changes in the number of neurons. iScience 2021; 24:102490. [PMID: 34095784 PMCID: PMC8164038 DOI: 10.1016/j.isci.2021.102490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/03/2021] [Accepted: 04/27/2021] [Indexed: 11/27/2022] Open
Abstract
Many animals that lose neural tissue to injury or disease can maintain behavioral repertoires by regenerating new neurons or reorganizing existing neural circuits. However, most neuroscience small model organisms lack this high degree of neural plasticity. We show that Hydra vulgaris can maintain stable sensory-motor behaviors despite 2-fold changes in neuron count, due to naturally occurring size variation or surgical resection. Specifically, we find that both behavioral and neural responses to rapid temperature changes are maintained following these perturbations. We further describe possible mechanisms for the observed neural activity and argue that Hydra's radial symmetry may allow it to maintain stable behaviors when changes in the numbers of neurons do not selectively eliminate any specific neuronal cell type. These results suggest that Hydra provides a powerful model for studying how animals maintain stable sensory-motor responses within dynamic neural circuits and may lead to the development of general principles for injury-tolerant neural architectures.
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Affiliation(s)
| | - Soonyoung Kim
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Krishna N. Badhiwala
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Benjamin W. Avants
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Jacob T. Robinson
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA
- Department of Neuroscience, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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19
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EFA6 in Axon Regeneration, as a Microtubule Regulator and as a Guanine Nucleotide Exchange Factor. Cells 2021; 10:cells10061325. [PMID: 34073530 PMCID: PMC8226579 DOI: 10.3390/cells10061325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/23/2021] [Accepted: 05/24/2021] [Indexed: 11/17/2022] Open
Abstract
Axon regeneration after injury is a conserved biological process that involves a large number of molecular pathways, including rapid calcium influx at injury sites, retrograde injury signaling, epigenetic transition, transcriptional reprogramming, polarized transport, and cytoskeleton reorganization. Despite the numerous efforts devoted to understanding the underlying cellular and molecular mechanisms of axon regeneration, the search continues for effective target molecules for improving axon regeneration. Although there have been significant historical efforts towards characterizing pro-regenerative factors involved in axon regeneration, the pursuit of intrinsic inhibitors is relatively recent. EFA6 (exchange factor for ARF6) has been demonstrated to inhibit axon regeneration in different organisms. EFA6 inhibition could be a promising therapeutic strategy to promote axon regeneration and functional recovery after axon injury. This review summarizes the inhibitory role on axon regeneration through regulating microtubule dynamics and through affecting ARF6 (ADP-ribosylation factor 6) GTPase-mediated integrin transport.
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20
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Molecular Basis of Neuronal Autophagy in Ageing: Insights from Caenorhabditis elegans. Cells 2021; 10:cells10030694. [PMID: 33800981 PMCID: PMC8004021 DOI: 10.3390/cells10030694] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 01/19/2023] Open
Abstract
Autophagy is an evolutionarily conserved degradation process maintaining cell homeostasis. Induction of autophagy is triggered as a response to a broad range of cellular stress conditions, such as nutrient deprivation, protein aggregation, organelle damage and pathogen invasion. Macroautophagy involves the sequestration of cytoplasmic contents in a double-membrane organelle referred to as the autophagosome with subsequent degradation of its contents upon delivery to lysosomes. Autophagy plays critical roles in development, maintenance and survival of distinct cell populations including neurons. Consequently, age-dependent decline in autophagy predisposes animals for age-related diseases including neurodegeneration and compromises healthspan and longevity. In this review, we summarize recent advances in our understanding of the role of neuronal autophagy in ageing, focusing on studies in the nematode Caenorhabditis elegans.
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21
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Abstract
During multicellular organism development, complex structures are sculpted to form organs and tissues, which are maintained throughout adulthood. Many of these processes require cells to fuse with one another, or with themselves. These plasma membrane fusions merge endoplasmic cellular content across external, exoplasmic, space. In the nematode Caenorhabditis elegans, such cell fusions serve as a unique sculpting force, involved in the embryonic morphogenesis of the skin-like multinuclear hypodermal cells, but also in refining delicate structures, such as valve openings and the tip of the tail. During post-embryonic development, plasma membrane fusions continue to shape complex neuron structures and organs such as the vulva, while during adulthood fusion participates in cell and tissue repair. These processes rely on two fusion proteins (fusogens): EFF-1 and AFF-1, which are part of a broader family of structurally related membrane fusion proteins, encompassing sexual reproduction, viral infection, and tissue remodeling. The established capabilities of these exoplasmic fusogens are further expanded by new findings involving EFF-1 and AFF-1 in endocytic vesicle fission and phagosome sealing. Tight regulation by cell-autonomous and non-cell autonomous mechanisms orchestrates these diverse cell fusions at the correct place and time-these processes and their significance are discussed in this review.
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22
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Axon Injury-Induced Autophagy Activation Is Impaired in a C. elegans Model of Tauopathy. Int J Mol Sci 2020; 21:ijms21228559. [PMID: 33202845 PMCID: PMC7696692 DOI: 10.3390/ijms21228559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 12/13/2022] Open
Abstract
Autophagy is a conserved pathway that plays a key role in cell homeostasis in normal settings, as well as abnormal and stress conditions. Autophagy dysfunction is found in various neurodegenerative diseases, although it remains unclear whether autophagy impairment is a contributor or consequence of neurodegeneration. Axonal injury is an acute neuronal stress that triggers autophagic responses in an age-dependent manner. In this study, we investigate the injury-triggered autophagy response in a C. elegans model of tauopathy. We found that transgenic expression of pro-aggregant Tau, but not the anti-aggregant Tau, abolished axon injury-induced autophagy activation, resulting in a reduced axon regeneration capacity. Furthermore, axonal trafficking of autophagic vesicles were significantly reduced in the animals expressing pro-aggregant F3ΔK280 Tau, indicating that Tau aggregation impairs autophagy regulation. Importantly, the reduced number of total or trafficking autophagic vesicles in the tauopathy model was not restored by the autophagy activator rapamycin. Loss of PTL-1, the sole Tau homologue in C. elegans, also led to impaired injury-induced autophagy activation, but with an increased basal level of autophagic vesicles. Therefore, we have demonstrated that Tau aggregation as well as Tau depletion both lead to disruption of injury-induced autophagy responses, suggesting that aberrant protein aggregation or microtubule dysfunction can modulate autophagy regulation in neurons after injury.
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23
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Vanhunsel S, Beckers A, Moons L. Designing neuroreparative strategies using aged regenerating animal models. Ageing Res Rev 2020; 62:101086. [PMID: 32492480 DOI: 10.1016/j.arr.2020.101086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/13/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022]
Abstract
In our ever-aging world population, the risk of age-related neuropathies has been increasing, representing both a social and economic burden to society. Since the ability to regenerate in the adult mammalian central nervous system is very limited, brain trauma and neurodegeneration are often permanent. As a consequence, novel scientific challenges have emerged and many research efforts currently focus on triggering repair in the damaged or diseased brain. Nevertheless, stimulating neuroregeneration remains ambitious. Even though important discoveries have been made over the past decades, they did not translate into a therapy yet. Actually, this is not surprising; while these disorders mainly manifest in aged individuals, most of the research is being performed in young animal models. Aging of neurons and their environment, however, greatly affects the central nervous system and its capacity to repair. This review provides a detailed overview of the impact of aging on central nervous system functioning and regeneration potential, both in non-regenerating and spontaneously regenerating animal models. Additionally, we highlight the need for aging animal models with regenerative capacities in the search for neuroreparative strategies.
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Affiliation(s)
- Sophie Vanhunsel
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - An Beckers
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium.
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24
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Nieuwenhuis B, Barber AC, Evans RS, Pearson CS, Fuchs J, MacQueen AR, van Erp S, Haenzi B, Hulshof LA, Osborne A, Conceicao R, Khatib TZ, Deshpande SS, Cave J, Ffrench‐Constant C, Smith PD, Okkenhaug K, Eickholt BJ, Martin KR, Fawcett JW, Eva R. PI 3-kinase delta enhances axonal PIP 3 to support axon regeneration in the adult CNS. EMBO Mol Med 2020; 12:e11674. [PMID: 32558386 PMCID: PMC7411663 DOI: 10.15252/emmm.201911674] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 12/27/2022] Open
Abstract
Peripheral nervous system (PNS) neurons support axon regeneration into adulthood, whereas central nervous system (CNS) neurons lose regenerative ability after development. To better understand this decline whilst aiming to improve regeneration, we focused on phosphoinositide 3-kinase (PI3K) and its product phosphatidylinositol (3,4,5)-trisphosphate (PIP3 ). We demonstrate that adult PNS neurons utilise two catalytic subunits of PI3K for axon regeneration: p110α and p110δ. However, in the CNS, axonal PIP3 decreases with development at the time when axon transport declines and regenerative competence is lost. Overexpressing p110α in CNS neurons had no effect; however, expression of p110δ restored axonal PIP3 and increased regenerative axon transport. p110δ expression enhanced CNS regeneration in both rat and human neurons and in transgenic mice, functioning in the same way as the hyperactivating H1047R mutation of p110α. Furthermore, viral delivery of p110δ promoted robust regeneration after optic nerve injury. These findings establish a deficit of axonal PIP3 as a key reason for intrinsic regeneration failure and demonstrate that native p110δ facilitates axon regeneration by functioning in a hyperactive fashion.
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Affiliation(s)
- Bart Nieuwenhuis
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Laboratory for Regeneration of Sensorimotor SystemsNetherlands Institute for NeuroscienceRoyal Netherlands Academy of Arts and Sciences (KNAW)AmsterdamThe Netherlands
| | - Amanda C Barber
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Rachel S Evans
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Craig S Pearson
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Joachim Fuchs
- Institute of BiochemistryCharité – Universitätsmedizin BerlinBerlinGermany
| | - Amy R MacQueen
- Laboratory of Lymphocyte Signalling and DevelopmentBabraham InstituteCambridgeUK
| | - Susan van Erp
- MRC Centre for Regenerative MedicineUniversity of EdinburghEdinburghUK
| | - Barbara Haenzi
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Lianne A Hulshof
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Andrew Osborne
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Raquel Conceicao
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Tasneem Z Khatib
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Sarita S Deshpande
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | - Joshua Cave
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
| | | | | | | | - Britta J Eickholt
- Institute of BiochemistryCharité – Universitätsmedizin BerlinBerlinGermany
| | - Keith R Martin
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Centre for Eye Research AustraliaRoyal Victorian Eye and Ear HospitalMelbourneVic.Australia
- OphthalmologyDepartment of SurgeryUniversity of MelbourneMelbourneVic.Australia
| | - James W Fawcett
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
- Centre of Reconstructive NeuroscienceInstitute of Experimental MedicineCzech Academy of SciencesPragueCzech Republic
| | - Richard Eva
- John Van Geest Centre for Brain RepairDepartment of Clinical NeurosciencesUniversity of CambridgeCambridgeUK
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25
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Jin Y, Zheng B. Multitasking: Dual Leucine Zipper-Bearing Kinases in Neuronal Development and Stress Management. Annu Rev Cell Dev Biol 2020; 35:501-521. [PMID: 31590586 DOI: 10.1146/annurev-cellbio-100617-062644] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The dual leucine zipper-bearing kinase (DLK) and leucine zipper-bearing kinase (LZK) are evolutionarily conserved MAPKKKs of the mixed-lineage kinase family. Acting upstream of stress-responsive JNK and p38 MAP kinases, DLK and LZK have emerged as central players in neuronal responses to a variety of acute and traumatic injuries. Recent studies also implicate their function in astrocytes, microglia, and other nonneuronal cells, reflecting their expanding roles in the multicellular response to injury and in disease. Of particular note is the potential link of these kinases to neurodegenerative diseases and cancer. It is thus critical to understand the physiological contexts under which these kinases are activated, as well as the signal transduction mechanisms that mediate specific functional outcomes. In this review we first provide a historical overview of the biochemical and functional dissection of these kinases. We then discuss recent findings on regulating their activity to enhance cellular protection following injury and in disease, focusing on but not limited to the nervous system.
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Affiliation(s)
- Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, USA; .,Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA;
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA; .,VA San Diego Healthcare System, San Diego, California 92161, USA
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26
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LaBella ML, Hujber EJ, Moore KA, Rawson RL, Merrill SA, Allaire PD, Ailion M, Hollien J, Bastiani MJ, Jorgensen EM. Casein Kinase 1δ Stabilizes Mature Axons by Inhibiting Transcription Termination of Ankyrin. Dev Cell 2020; 52:88-103.e18. [PMID: 31910362 DOI: 10.1016/j.devcel.2019.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/09/2019] [Accepted: 12/10/2019] [Indexed: 01/19/2023]
Abstract
After axon outgrowth and synapse formation, the nervous system transitions to a stable architecture. In C. elegans, this transition is marked by the appearance of casein kinase 1δ (CK1δ) in the nucleus. In CK1δ mutants, neurons continue to sprout growth cones into adulthood, leading to a highly ramified nervous system. Nervous system architecture in these mutants is completely restored by suppressor mutations in ten genes involved in transcription termination. CK1δ prevents termination by phosphorylating and inhibiting SSUP-72. SSUP-72 would normally remodel the C-terminal domain of RNA polymerase in anticipation of termination. The antitermination activity of CK1δ establishes the mature state of a neuron by promoting the expression of the long isoform of a single gene, the cytoskeleton protein Ankyrin.
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Affiliation(s)
- Matthew L LaBella
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Edward J Hujber
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Kristin A Moore
- Department of Biology, University of Utah, Salt Lake City, UT, USA
| | - Randi L Rawson
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Sean A Merrill
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Patrick D Allaire
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Julie Hollien
- Department of Biology, University of Utah, Salt Lake City, UT, USA
| | | | - Erik M Jorgensen
- Department of Biology, Howard Hughes Medical Institute, University of Utah, Salt Lake City, UT, USA.
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27
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Manjarrez JR, Mailler R. Stress and timing associated with Caenorhabditis elegans immobilization methods. Heliyon 2020; 6:e04263. [PMID: 32671240 PMCID: PMC7339059 DOI: 10.1016/j.heliyon.2020.e04263] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 11/12/2019] [Accepted: 06/17/2020] [Indexed: 12/11/2022] Open
Abstract
Background Caenorhabditis elegans is a model organism used to study gene, protein, and cell influence on function and behavior. These studies frequently require C. elegans to be immobilized for imaging or laser ablation experiments. There are a number of known techniques for immobilizing worms, but to our knowledge, there are no comprehensive studies of the various agents in common use today. New method This study determines the relationship between concentration, immobilization time, exposure time, and recovery likelihood for several immobilization agents. The agents used in this study are 1-Phenoxy-2-propanol, levamisole, sodium azide, polystyrene beads, and environmental cold shock. These tests are conducted using a humidified chamber to keep chemical concentrations consistent. Each of these agents is also tested to determine if they exhibit stress-related after effects using the gcs-1, daf-16, hsp-4, hif-1, hsp-16.2, and tmem-135 stress reporters. Results We present a range of quick mount immobilization and recovery conditions for each agent tested. This study shows that, under controlled conditions, 1-Phenoxy-2-propanol shows significant stress from the daf-16 reporter. While 1-Phenoxy-2-propanol and sodium azide both create stress related after effects with long term recovery in the case of the hsp-16.2 reporter. Comparison with existing method(s) This study shows that commonly used concentrations of immobilizing agents are ineffective when evaporation is prevented. Conclusions To improve reproducibility of results it is essential to use consistent concentrations of immobilizing agents. It is also critically important to account for stress-related after effects elicited by immobilization agents when designing any experiment.
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Affiliation(s)
| | - Roger Mailler
- University of Tulsa, 800 S. Tucker Dr., Tulsa, OK, 74104, USA
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Kiyoshi C, Tedeschi A. Axon growth and synaptic function: A balancing act for axonal regeneration and neuronal circuit formation in CNS trauma and disease. Dev Neurobiol 2020; 80:277-301. [PMID: 32902152 PMCID: PMC7754183 DOI: 10.1002/dneu.22780] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022]
Abstract
Axons in the adult mammalian central nervous system (CNS) fail to regenerate inside out due to intrinsic and extrinsic neuronal determinants. During CNS development, axon growth, synapse formation, and function are tightly regulated processes allowing immature neurons to effectively grow an axon, navigate toward target areas, form synaptic contacts and become part of information processing networks that control behavior in adulthood. Not only immature neurons are able to precisely control the expression of a plethora of genes necessary for axon extension and pathfinding, synapse formation and function, but also non-neuronal cells such as astrocytes and microglia actively participate in sculpting the nervous system through refinement, consolidation, and elimination of synaptic contacts. Recent evidence indicates that a balancing act between axon regeneration and synaptic function may be crucial for rebuilding functional neuronal circuits after CNS trauma and disease in adulthood. Here, we review the role of classical and new intrinsic and extrinsic neuronal determinants in the context of CNS development, injury, and disease. Moreover, we discuss strategies targeting neuronal and non-neuronal cell behaviors, either alone or in combination, to promote axon regeneration and neuronal circuit formation in adulthood.
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Affiliation(s)
- Conrad Kiyoshi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
| | - Andrea Tedeschi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
- Discovery Theme on Chronic Brain Injury, The Ohio State University, Columbus, OH 43210, USA
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29
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Brief Electrical Stimulation Triggers an Effective Regeneration of Leech CNS. eNeuro 2020; 7:ENEURO.0030-19.2020. [PMID: 32471846 PMCID: PMC7317182 DOI: 10.1523/eneuro.0030-19.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 05/05/2020] [Accepted: 05/06/2020] [Indexed: 01/01/2023] Open
Abstract
The search for therapeutic strategies to promote neuronal regeneration following injuries toward functional recovery is of great importance. Brief low-frequency electrical stimulation (ES) has been reported as a useful method to improve neuronal regeneration in different animal models; however, the effect of ES on single neuron behavior has not been shown. Here, we study the effect of brief ES on neuronal regeneration of the CNS of adult medicinal leeches. Studying the regeneration of selected sets of identified neurons allow us to quantify the ES effect per cell type at the single-cell level. Chains of the CNS that were subjected to cut injury were observed for 3 d, and the spontaneous regeneration was compared with the electrically stimulated injured chains. We show that the ES improves the efficiency of regeneration of Retzius cells, as larger masses of the total branching tree traverse the injury site with better directed growth with no effect on the average branching tree length. No antero-posterior polarity was found along regeneration within the leech CNS. Moreover, the microglial cell distribution was examined revealing more microglial cells in proximity to the stimulation site compared with non-stimulated. Our results lay a foundation for future ES-based neuroregenerative therapies.
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30
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Harreguy MB, Marfil V, Grooms NWF, Gabel CV, Chung SH, Haspel G. Ytterbium-doped fibre femtosecond laser offers robust operation with deep and precise microsurgery of C. elegans neurons. Sci Rep 2020; 10:4545. [PMID: 32161333 PMCID: PMC7066168 DOI: 10.1038/s41598-020-61479-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 02/25/2020] [Indexed: 11/15/2022] Open
Abstract
Laser microsurgery is a powerful tool for neurobiology, used to ablate cells and sever neurites in-vivo. We compare a relatively new laser source to two well-established designs. Rare-earth-doped mode-locked fibre lasers that produce high power pulses recently gained popularity for industrial uses. Such systems are manufactured to high standards of robustness and low maintenance requirements typical of solid-state lasers. We demonstrate that an Ytterbium-doped fibre femtosecond laser is comparable in precision to a Ti:Sapphire femtosecond laser (1-2 micrometres), but with added operational reliability. Due to the lower pulse energy required to ablate, it is more precise than a solid-state nanosecond laser. Due to reduced scattering of near infrared light, it can lesion deeper (more than 100 micrometres) in tissue. These advantages are not specific to the model system ablated for our demonstration, namely neurites in the nematode C. elegans, but are applicable to other systems and transparent tissue where a precise micron-resolution dissection is required.
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Affiliation(s)
- M B Harreguy
- New Jersey Institute of Technology and Rutgers University, Federated Department of Biological Sciences and New Jersey Institute of Technology, Institute of Brain Research and Neuroscience, 100 Summit St, Newark, NJ, 07102, USA
| | - V Marfil
- New Jersey Institute of Technology and Rutgers University, Federated Department of Biological Sciences and New Jersey Institute of Technology, Institute of Brain Research and Neuroscience, 100 Summit St, Newark, NJ, 07102, USA
| | - N W F Grooms
- Northeastern University, Department of Bioengineering, 360 Huntington Avenue, Boston, MA, 02115, USA
| | - C V Gabel
- Department of Physiology and Biophysics and Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine and Boston University Photonics Center, 700 Albany St, Boston, Massachusetts, 02215, USA
| | - S H Chung
- Northeastern University, Department of Bioengineering, 360 Huntington Avenue, Boston, MA, 02115, USA.
| | - G Haspel
- New Jersey Institute of Technology and Rutgers University, Federated Department of Biological Sciences and New Jersey Institute of Technology, Institute of Brain Research and Neuroscience, 100 Summit St, Newark, NJ, 07102, USA.
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31
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Tang NH, Kim KW, Xu S, Blazie SM, Yee BA, Yeo GW, Jin Y, Chisholm AD. The mRNA Decay Factor CAR-1/LSM14 Regulates Axon Regeneration via Mitochondrial Calcium Dynamics. Curr Biol 2020; 30:865-876.e7. [PMID: 31983639 DOI: 10.1016/j.cub.2019.12.061] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/26/2019] [Accepted: 12/19/2019] [Indexed: 12/11/2022]
Abstract
mRNA decay factors regulate mRNA turnover by recruiting non-translating mRNAs and targeting them for translational repression and mRNA degradation. How mRNA decay pathways regulate cellular function in vivo with specificity is poorly understood. Here, we show that C. elegans mRNA decay factors, including the translational repressors CAR-1/LSM14 and CGH-1/DDX6, and the decapping enzymes DCAP-1/DCP1, function in neurons to differentially regulate axon development, maintenance, and regrowth following injury. In neuronal cell bodies, CAR-1 fully colocalizes with CGH-1 and partially colocalizes with DCAP-1, suggesting that mRNA decay components form at least two types of cytoplasmic granules. Following axon injury in adult neurons, loss of CAR-1 or CGH-1 results in increased axon regrowth and growth cone formation, whereas loss of DCAP-1 or DCAP-2 results in reduced regrowth. To determine how CAR-1 inhibits regrowth, we analyzed mRNAs bound to pan-neuronally expressed GFP::CAR-1 using a crosslinking and immunoprecipitation-based approach. Among the putative mRNA targets of CAR-1, we characterized the roles of micu-1, a regulator of the mitochondrial calcium uniporter MCU-1, in axon injury. We show that loss of car-1 results increased MICU-1 protein levels, and that enhanced axon regrowth in car-1 mutants is dependent on micu-1 and mcu-1. Moreover, axon injury induces transient calcium influx into axonal mitochondria, dependent on MCU-1. In car-1 loss-of-function mutants and in micu-1 overexpressing animals, the axonal mitochondrial calcium influx is more sustained, which likely underlies enhanced axon regrowth. Our data uncover a novel pathway that controls axon regrowth through axonal mitochondrial calcium uptake.
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Affiliation(s)
- Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kyung Won Kim
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Suhong Xu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Stephen M Blazie
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Brian A Yee
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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32
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Ko SH, Apple EC, Liu Z, Chen L. Age-dependent autophagy induction after injury promotes axon regeneration by limiting NOTCH. Autophagy 2020; 16:2052-2068. [PMID: 31920157 DOI: 10.1080/15548627.2020.1713645] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Macroautophagy/autophagy is essential for maintaining cellular homeostasis through the degradation of organelles and proteins. It also has a prominent role in modulating aging. However, the role of autophagy in the neuronal response to axon injury and axon regeneration, particularly in the context of aging, remains largely unknown. Our candidate genetic screen for axon regeneration regulators has identified genes in the autophagy pathway. Using a reporter that monitors autophagosomes and autolysosomes, we were able to monitor the dynamics of autophagy during axon regeneration. In response to axon injury, there was a significant increase in the number of autophagic vesicles. Injury-triggered autophagy activation and axon regeneration capacity undergo an age-dependent decline, and autophagy-activating agents partially rescued these declines. We found that DLK-1 was both required and sufficient for injury-induced autophagy activation. Autophagic vesicles co-localized with the NOTCH4 ortholog, LIN-12 receptor, a previously identified inhibitor of axon regeneration. Epistasis analyses indicate that LIN-12 might be a target of autophagy in axon regeneration. Together, our data suggest that DLK-mediated injury signaling can activate autophagy, which might limit the level of LIN-12 and NOTCH proteins to promote axon regeneration. Our findings reveal that autophagy activation can promote axon regeneration in neurons that lack maximal regrowth capacity, providing a promising therapeutic strategy for axon injury. Abbreviations: 3-MA: 3-methyladenine; ALs: autolysosomes; APs: autophagosomes; ARF-6: ADP-Ribosylation Factor related 6; ATG-9: AuTophaGy (yeast Atg homolog) 9; ATG9A: autophagy related 9A; BA1: bafilomycin A1; BEC-1: BEClin (human autophagy) homolog; BECN1: beclin 1; C. elegans: Caenorhabditis elegans; CEBP-1: C/EBP (CCAAT/enhancer-binding protein) homolog; CNS: central nervous system; DLK-1: Dual-Leucine zipper Kinase; DMSO: dimethyl sulfoxide; DRG: dorsal root ganglion; FOS: Fos proto-oncogene, AP-1 transcription factor subunit; GABA: gamma-aminobutyric acid; GFP: green fluorescent protein; HDA-3: Histone DeAcetylase; IP3: inositol trisphosphate; ITR-1: Inositol Triphosphate Receptor; KLF-2: Kruppel-Like Factor (zinc finger protein) 2; LGG-1: LC3, GABARAP and GATE-16 family; MAK-2: MAP kinase Activated protein Kinase; MAP kinase: mitogen-activated protein kinase; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MKK-4: mitogen activated protein kinase kinase 4; MTOR: mechanistic target of rapamycin kinase; NGM: nematode growth medium; NICD: Notch intracellular domain; NOTCH: notch receptor; PLM: posterior lateral microtubule; PMK-3: P38 Map kinase family; PNS: peripheral nervous system; SCG10: superior cervical ganglion protein 10; SCI: spinal cord injury; UNC-51: UNCoordinated 51; ULK1: unc-51 like autophagy activating kinase 1; wnd: wallenda.
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Affiliation(s)
- Su-Hyuk Ko
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Ellen C Apple
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Zhijie Liu
- Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
| | - Lizhen Chen
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA.,Department of Molecular Medicine, University of Texas Health Science Center at San Antonio , San Antonio, TX, USA
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33
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Rodemer W, Hu J, Selzer ME, Shifman MI. Heterogeneity in the regenerative abilities of central nervous system axons within species: why do some neurons regenerate better than others? Neural Regen Res 2020; 15:996-1005. [PMID: 31823869 PMCID: PMC7034288 DOI: 10.4103/1673-5374.270298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Some neurons, especially in mammalian peripheral nervous system or in lower vertebrate or in vertebrate central nervous system (CNS) regenerate after axotomy, while most mammalian CNS neurons fail to regenerate. There is an emerging consensus that neurons have different intrinsic regenerative capabilities, which theoretically could be manipulated therapeutically to improve regeneration. Population-based comparisons between “good regenerating” and “bad regenerating” neurons in the CNS and peripheral nervous system of most vertebrates yield results that are inconclusive or difficult to interpret. At least in part, this reflects the great diversity of cells in the mammalian CNS. Using mammalian nervous system imposes several methodical limitations. First, the small sizes and large numbers of neurons in the CNS make it very difficult to distinguish regenerating neurons from non-regenerating ones. Second, the lack of identifiable neurons makes it impossible to correlate biochemical changes in a neuron with axonal damage of the same neuron, and therefore, to dissect the molecular mechanisms of regeneration on the level of single neurons. This review will survey the reported responses to axon injury and the determinants of axon regeneration, emphasizing non-mammalian model organisms, which are often under-utilized, but in which the data are especially easy to interpret.
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Affiliation(s)
- William Rodemer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Jianli Hu
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation); Department of Neurology, the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Michael I Shifman
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), the Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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34
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Andrusiak MG, Sharifnia P, Lyu X, Wang Z, Dickey AM, Wu Z, Chisholm AD, Jin Y. Inhibition of Axon Regeneration by Liquid-like TIAR-2 Granules. Neuron 2019; 104:290-304.e8. [PMID: 31378567 PMCID: PMC6813885 DOI: 10.1016/j.neuron.2019.07.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 05/19/2019] [Accepted: 07/02/2019] [Indexed: 12/21/2022]
Abstract
Phase separation into liquid-like compartments is an emerging property of proteins containing prion-like domains (PrLDs), yet the in vivo roles of phase separation remain poorly understood. TIA proteins contain a C-terminal PrLD, and mutations in the PrLD are associated with several diseases. Here, we show that the C. elegans TIAR-2/TIA protein functions cell autonomously to inhibit axon regeneration. TIAR-2 undergoes liquid-liquid phase separation in vitro and forms granules with liquid-like properties in vivo. Axon injury induces a transient increase in TIAR-2 granule number. The PrLD is necessary and sufficient for granule formation and inhibiting regeneration. Tyrosine residues within the PrLD are important for granule formation and inhibition of regeneration. TIAR-2 is also serine phosphorylated in vivo. Non-phosphorylatable TIAR-2 variants do not form granules and are unable to inhibit axon regeneration. Our data demonstrate an in vivo function for phase-separated TIAR-2 and identify features critical for its function in axon regeneration.
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Affiliation(s)
- Matthew G Andrusiak
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Panid Sharifnia
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xiaohui Lyu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zhiping Wang
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrea M Dickey
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Zilu Wu
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew D Chisholm
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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35
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Malinow RA, Ying P, Koorman T, Boxem M, Jin Y, Kim KW. Functional Dissection of C. elegans bZip-Protein CEBP-1 Reveals Novel Structural Motifs Required for Axon Regeneration and Nuclear Import. Front Cell Neurosci 2019; 13:348. [PMID: 31417366 PMCID: PMC6685058 DOI: 10.3389/fncel.2019.00348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/15/2019] [Indexed: 12/02/2022] Open
Abstract
The basic leucine-zipper (bZIP) domain transcription factors CCAAT/enhancer-binding proteins (C/EBP) have a variety of roles in cell proliferation, differentiation, and stress response. In the nervous system, several isoforms of C/EBP function in learning and memory, neuronal plasticity, neuroinflammation, and axon regeneration. We previously reported that the Caenorhabditis elegans C/EBP homolog, CEBP-1, is essential for axon regeneration. CEBP-1 consists of 319 amino acids, with its bZIP domain at the C-terminus and a long N-terminal fragment with no known protein motifs. Here, using forward genetic screening with targeted genome editing, we have identified a unique domain in the N-terminus that is critical for its in vivo function. Additionally, we characterized three nuclear localization signals (NLS) in CEBP-1 that act together to mediate CEBP-1’s nuclear import. Moreover, the Importin-α, IMA-3, can bind to CEBP-1 via one of the NLS. ima-3 is ubiquitously expressed in all somatic cells, and ima-3 null mutants are larval lethal. Using Cre-lox dependent neuron-specific deletion strategy, we show that ima-3 is not critical for axon development, but is required for axon regeneration in adults. Together, these data advance our understanding of CEBP-1’s function, and suggest new regulators that remain to be identified to expand the CEBP-1 protein interactome.
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Affiliation(s)
- Rose Aria Malinow
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Phoenix Ying
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Thijs Koorman
- Department of Biology, Utrecht University, Utrecht, Netherlands
| | - Mike Boxem
- Department of Biology, Utrecht University, Utrecht, Netherlands
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Kyung Won Kim
- Convergence Program of Material Science for Medicine and Pharmaceutics, Department of Life Science, Multidisciplinary Genome Institute, Hallym University, Chuncheon, South Korea
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Perrin FE, Noristani HN. Serotonergic mechanisms in spinal cord injury. Exp Neurol 2019; 318:174-191. [PMID: 31085200 DOI: 10.1016/j.expneurol.2019.05.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/12/2022]
Abstract
Spinal cord injury (SCI) is a tragic event causing irreversible losses of sensory, motor, and autonomic functions, that may also be associated with chronic neuropathic pain. Serotonin (5-HT) neurotransmission in the spinal cord is critical for modulating sensory, motor, and autonomic functions. Following SCI, 5-HT axons caudal to the lesion site degenerate, and the degree of axonal degeneration positively correlates with lesion severity. Rostral to the lesion, 5-HT axons sprout, irrespective of the severity of the injury. Unlike callosal fibers and cholinergic projections, 5-HT axons are more resistant to an inhibitory milieu and undergo active sprouting and regeneration after central nervous system (CNS) traumatism. Numerous studies suggest that a chronic increase in serotonergic neurotransmission promotes 5-HT axon sprouting in the intact CNS. Moreover, recent studies in invertebrates suggest that 5-HT has a pro-regenerative role in injured axons. Here we present a brief description of 5-HT discovery, 5-HT innervation of the CNS, and physiological functions of 5-HT in the spinal cord, including its role in controlling bladder function. We then present a comprehensive overview of changes in serotonergic axons after CNS damage, and discuss their plasticity upon altered 5-HT neurotransmitter levels. Subsequently, we provide an in-depth review of therapeutic approaches targeting 5-HT neurotransmission, as well as other pre-clinical strategies to promote an increase in re-growth of 5-HT axons, and their functional consequences in SCI animal models. Finally, we highlight recent findings signifying the direct role of 5-HT in axon regeneration and suggest strategies to further promote robust long-distance re-growth of 5-HT axons across the lesion site and eventually achieve functional recovery following SCI.
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Affiliation(s)
- Florence Evelyne Perrin
- University of Montpellier, Montpellier, F-34095 France; INSERM, U1198, Montpellier, F-34095 France; EPHE, Paris, F-75014 France
| | - Harun Najib Noristani
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
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37
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Zheng B, Lorenzana AO, Ma L. Understanding the axonal response to injury by in vivo imaging in the mouse spinal cord: A tale of two branches. Exp Neurol 2019; 318:277-285. [PMID: 30986398 PMCID: PMC6588497 DOI: 10.1016/j.expneurol.2019.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 01/01/2023]
Abstract
Understanding the basic properties of how axons respond to injury in the mammalian central nervous system (CNS) is of fundamental value for developing strategies to promote neural repair. Axons possess complex morphologies with stereotypical branching patterns. However, current knowledge of the axonal response to injury gives little consideration to axonal branches, nor do strategies to promote axon regeneration. This article reviews evidence from in vivo spinal cord imaging that axonal branches markedly impact the degenerative and regenerative responses to injury. At a major bifurcation point, depending on whether one or both axonal branches are injured, neurons may choose either a more self-preservative response or a more dynamic response. The stabilizing effect of the spared branch may underlie a well-known divergence in neuronal responses to injury, and illustrates an example where in vivo spinal cord imaging reveals insights that are difficult to elucidate with conventional histological methods.
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Affiliation(s)
- Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA.
| | - Ariana O Lorenzana
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Le Ma
- Department of Neuroscience, Jefferson Synaptic Biology Center, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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38
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Abstract
How the nervous system is wired has been a central question of neuroscience since the inception of the field, and many of the foundational discoveries and conceptual advances have been made through the study of invertebrate experimental organisms, including Caenorhabditis elegans and Drosophila melanogaster. Although many guidance molecules and receptors have been identified, recent experiments have shed light on the many modes of action for these pathways. Here, we summarize the recent progress in determining how the physical and temporal constraints of the surrounding environment provide instructive regulations in nervous system wiring. We use Netrin and its receptors as an example to analyze the complexity of how they guide neurite outgrowth. In neurite repair, conserved injury detection and response-signaling pathways regulate gene expression and cytoskeletal dynamics. We also describe recent developments in the research on molecular mechanisms of neurite regeneration in worms and flies.
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Affiliation(s)
- Claire E Richardson
- Department of Biology, Stanford University, Stanford, California 94305, USA;
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, California 94305, USA; .,Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
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Cenik ES, Meng X, Tang NH, Hall RN, Arribere JA, Cenik C, Jin Y, Fire A. Maternal Ribosomes Are Sufficient for Tissue Diversification during Embryonic Development in C. elegans. Dev Cell 2019; 48:811-826.e6. [PMID: 30799226 DOI: 10.1016/j.devcel.2019.01.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 11/06/2018] [Accepted: 01/21/2019] [Indexed: 12/20/2022]
Abstract
Caenorhabditis elegans provides an amenable system to explore whether newly composed ribosomes are required to progress through development. Despite the complex pattern of tissues that are formed during embryonic development, we found that null homozygotes lacking any of the five different ribosomal proteins (RPs) can produce fully functional first-stage larvae, with similar developmental competence seen upon complete deletion of the multi-copy ribosomal RNA locus. These animals, relying on maternal but not zygotic contribution of ribosomal components, are capable of completing embryogenesis. In the absence of new ribosomal components, the resulting animals are arrested before progression from the first larval stage and fail in two assays for postembryonic plasticity of neuronal structure. Mosaic analyses of larvae that are a mixture of ribosome-competent and non-competent cells suggest a global regulatory mechanism in which ribosomal insufficiency in a subset of cells triggers organism-wide growth arrest.
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Affiliation(s)
- Elif Sarinay Cenik
- Department of Pathology, Stanford University Medical School, Stanford, CA, USA; Department of Molecular Biosciences, University of Texas Austin, Austin, TX, USA
| | - Xuefeng Meng
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, San Diego, CA, USA
| | - Ngang Heok Tang
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, San Diego, CA, USA
| | | | - Joshua A Arribere
- Department of MCD Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Can Cenik
- Department of Molecular Biosciences, University of Texas Austin, Austin, TX, USA
| | - Yishi Jin
- Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, San Diego, CA, USA
| | - Andrew Fire
- Department of Pathology, Stanford University Medical School, Stanford, CA, USA.
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40
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Caneo M, Julian V, Byrne AB, Alkema MJ, Calixto A. Diapause induces functional axonal regeneration after necrotic insult in C. elegans. PLoS Genet 2019; 15:e1007863. [PMID: 30640919 PMCID: PMC6347329 DOI: 10.1371/journal.pgen.1007863] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 01/25/2019] [Accepted: 11/29/2018] [Indexed: 02/07/2023] Open
Abstract
Many neurons are unable to regenerate after damage. The ability to regenerate after an insult depends on life stage, neuronal subtype, intrinsic and extrinsic factors. C. elegans is a powerful model to test the genetic and environmental factors that affect axonal regeneration after damage, since its axons can regenerate after neuronal insult. Here we demonstrate that diapause promotes the complete morphological regeneration of truncated touch receptor neuron (TRN) axons expressing a neurotoxic MEC-4(d) DEG/ENaC channel. Truncated axons of different lengths were repaired during diapause and we observed potent axonal regrowth from somas alone. Complete morphological regeneration depends on DLK-1 but neuronal sprouting and outgrowth is DLK-1 independent. We show that TRN regeneration is fully functional since animals regain their ability to respond to mechanical stimulation. Thus, diapause induced regeneration provides a simple model of complete axonal regeneration which will greatly facilitate the study of environmental and genetic factors affecting the rate at which neurons die.
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Affiliation(s)
- Mauricio Caneo
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
| | - Victoria Julian
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Alexandra B. Byrne
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Mark J. Alkema
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Andrea Calixto
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
- * E-mail: ,
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41
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Worms on a Chip. Bioanalysis 2019. [DOI: 10.1007/978-981-13-6229-3_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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42
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Neumann B, Linton C, Giordano-Santini R, Hilliard MA. Axonal fusion: An alternative and efficient mechanism of nerve repair. Prog Neurobiol 2018; 173:88-101. [PMID: 30500382 DOI: 10.1016/j.pneurobio.2018.11.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/22/2018] [Accepted: 11/26/2018] [Indexed: 02/07/2023]
Abstract
Injuries to the nervous system can cause lifelong morbidity due to the disconnect that occurs between nerve cells and their cellular targets. Re-establishing these lost connections is the ultimate goal of endogenous regenerative mechanisms, as well as those induced by exogenous manipulations in a laboratory or clinical setting. Reconnection between severed neuronal fibers occurs spontaneously in some invertebrate species and can be induced in mammalian systems. This process, known as axonal fusion, represents a highly efficient means of repair after injury. Recent progress has greatly enhanced our understanding of the molecular control of axonal fusion, demonstrating that the machinery required for the engulfment of apoptotic cells is repurposed to mediate the reconnection between severed axon fragments, which are subsequently merged by fusogen proteins. Here, we review our current understanding of naturally occurring axonal fusion events, as well as those being ectopically produced with the aim of achieving better clinical outcomes.
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Affiliation(s)
- Brent Neumann
- Neuroscience Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne VIC 3800, Australia.
| | - Casey Linton
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rosina Giordano-Santini
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
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43
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Kim KW, Tang NH, Piggott CA, Andrusiak MG, Park S, Zhu M, Kurup N, Cherra SJ, Wu Z, Chisholm AD, Jin Y. Expanded genetic screening in Caenorhabditis elegans identifies new regulators and an inhibitory role for NAD + in axon regeneration. eLife 2018; 7:39756. [PMID: 30461420 PMCID: PMC6281318 DOI: 10.7554/elife.39756] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/19/2018] [Indexed: 12/15/2022] Open
Abstract
The mechanisms underlying axon regeneration in mature neurons are relevant to the understanding of normal nervous system maintenance and for developing therapeutic strategies for injury. Here, we report novel pathways in axon regeneration, identified by extending our previous function-based screen using the C. elegans mechanosensory neuron axotomy model. We identify an unexpected role of the nicotinamide adenine dinucleotide (NAD+) synthesizing enzyme, NMAT-2/NMNAT, in axon regeneration. NMAT-2 inhibits axon regrowth via cell-autonomous and non-autonomous mechanisms. NMAT-2 enzymatic activity is required to repress regrowth. Further, we find differential requirements for proteins in membrane contact site, components and regulators of the extracellular matrix, membrane trafficking, microtubule and actin cytoskeleton, the conserved Kelch-domain protein IVNS-1, and the orphan transporter MFSD-6 in axon regrowth. Identification of these new pathways expands our understanding of the molecular basis of axonal injury response and regeneration.
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Affiliation(s)
- Kyung Won Kim
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Christopher A Piggott
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Matthew G Andrusiak
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Seungmee Park
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Ming Zhu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Naina Kurup
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Salvatore J Cherra
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Zilu Wu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States.,Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, United States
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44
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Noblett N, Wu Z, Ding ZH, Park S, Roenspies T, Flibotte S, Chisholm AD, Jin Y, Colavita A. DIP-2 suppresses ectopic neurite sprouting and axonal regeneration in mature neurons. J Cell Biol 2018; 218:125-133. [PMID: 30396999 PMCID: PMC6314549 DOI: 10.1083/jcb.201804207] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/09/2018] [Accepted: 10/24/2018] [Indexed: 02/08/2023] Open
Abstract
Neuronal morphology and circuitry established during early development must often be maintained over the entirety of animal lifespans. Compared with neuronal development, the mechanisms that maintain mature neuronal structures and architecture are little understood. The conserved disco-interacting protein 2 (DIP2) consists of a DMAP1-binding domain and two adenylate-forming domains (AFDs). We show that the Caenorhabditis elegans DIP-2 maintains morphology of mature neurons. dip-2 loss-of-function mutants display a progressive increase in ectopic neurite sprouting and branching during late larval and adult life. In adults, dip-2 also inhibits initial stages of axon regeneration cell autonomously and acts in parallel to DLK-1 MAP kinase and EFA-6 pathways. The function of DIP-2 in maintenance of neuron morphology and in axon regrowth requires its AFD domains and is independent of its DMAP1-binding domain. Our findings reveal a new conserved regulator of neuronal morphology maintenance and axon regrowth after injury.
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Affiliation(s)
- Nathaniel Noblett
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Zilu Wu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Zhao Hua Ding
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Seungmee Park
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Tony Roenspies
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Stephane Flibotte
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA
| | - Antonio Colavita
- Neuroscience Program, Ottawa Hospital Research Institute, Ottawa, Canada .,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
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45
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McLaughlin CN, Broihier HT. Keeping Neurons Young and Foxy: FoxOs Promote Neuronal Plasticity. Trends Genet 2018; 34:65-78. [PMID: 29102406 DOI: 10.1016/j.tig.2017.10.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/27/2022]
Abstract
Any adult who has tried to take up the piano or learn a new language is faced with the sobering realization that acquiring such skills is more challenging as an adult than as a child. Neuronal plasticity, or the malleability of brain circuits, declines with age. Young neurons tend to be more adaptable and can alter the size and strength of their connections more readily than can old neurons. Myriad circuit- and synapse-level mechanisms that shape plasticity have been identified. Yet, molecular mechanisms setting the overall competence of young neurons for distinct forms of plasticity remain largely obscure. Recent studies indicate evolutionarily conserved roles for FoxO proteins in establishing the capacity for cell-fate, morphological, and synaptic plasticity in neurons.
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Affiliation(s)
- Colleen N McLaughlin
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Heather T Broihier
- Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
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46
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Curcio M, Bradke F. Axon Regeneration in the Central Nervous System: Facing the Challenges from the Inside. Annu Rev Cell Dev Biol 2018; 34:495-521. [DOI: 10.1146/annurev-cellbio-100617-062508] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
After an injury in the adult mammalian central nervous system (CNS), lesioned axons fail to regenerate. This failure to regenerate contrasts with axons’ remarkable potential to grow during embryonic development and after an injury in the peripheral nervous system (PNS). Several intracellular mechanisms—including cytoskeletal dynamics, axonal transport and trafficking, signaling and transcription of regenerative programs, and epigenetic modifications—control axon regeneration. In this review, we describe how manipulation of intrinsic mechanisms elicits a regenerative response in different organisms and how strategies are implemented to form the basis of a future regenerative treatment after CNS injury.
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Affiliation(s)
- Michele Curcio
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany;,
| | - Frank Bradke
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany;,
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47
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Petrova V, Eva R. The Virtuous Cycle of Axon Growth: Axonal Transport of Growth-Promoting Machinery as an Intrinsic Determinant of Axon Regeneration. Dev Neurobiol 2018; 78:898-925. [PMID: 29989351 DOI: 10.1002/dneu.22608] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 02/02/2023]
Abstract
Injury to the brain and spinal cord has devastating consequences because adult central nervous system (CNS) axons fail to regenerate. Injury to the peripheral nervous system (PNS) has a better prognosis, because adult PNS neurons support robust axon regeneration over long distances. CNS axons have some regenerative capacity during development, but this is lost with maturity. Two reasons for the failure of CNS regeneration are extrinsic inhibitory molecules, and a weak intrinsic capacity for growth. Extrinsic inhibitory molecules have been well characterized, but less is known about the neuron-intrinsic mechanisms which prevent axon re-growth. Key signaling pathways and genetic/epigenetic factors have been identified which can enhance regenerative capacity, but the precise cellular mechanisms mediating their actions have not been characterized. Recent studies suggest that an important prerequisite for regeneration is an efficient supply of growth-promoting machinery to the axon; however, this appears to be lacking from non-regenerative axons in the adult CNS. In the first part of this review, we summarize the evidence linking axon transport to axon regeneration. We discuss the developmental decline in axon regeneration capacity in the CNS, and comment on how this is paralleled by a similar decline in the selective axonal transport of regeneration-associated receptors such as integrins and growth factor receptors. In the second part, we discuss the mechanisms regulating selective polarized transport within neurons, how these relate to the intrinsic control of axon regeneration, and whether they can be targeted to enhance regenerative capacity. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 00: 000-000, 2018.
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Affiliation(s)
- Veselina Petrova
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
| | - Richard Eva
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
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48
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Xu F, Takahashi H, Tanaka Y, Ichinose S, Niwa S, Wicklund MP, Hirokawa N. KIF1Bβ mutations detected in hereditary neuropathy impair IGF1R transport and axon growth. J Cell Biol 2018; 217:3480-3496. [PMID: 30126838 PMCID: PMC6168269 DOI: 10.1083/jcb.201801085] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 05/31/2018] [Accepted: 07/05/2018] [Indexed: 02/07/2023] Open
Abstract
Uncovering the mechanistic link between kinesin motors and neuropathy, Xu et al. identify functional KIF1Bβ mutations in human hereditary neuropathy to analyze them in mouse models. They propose that KIF1Bβ transports IGF1R and facilitates axonal outgrowth. Both of these effects are significantly affected by the clinical mutations. KIF1Bβ is a kinesin-3 family anterograde motor protein essential for neuronal development, viability, and function. KIF1Bβ mutations have previously been reported in a limited number of pedigrees of Charcot-Marie-Tooth disease type 2A (CMT2A) neuropathy. However, the gene responsible for CMT2A is still controversial, and the mechanism of pathogenesis remains elusive. In this study, we show that the receptor tyrosine kinase IGF1R is a new direct binding partner of KIF1Bβ, and its binding and transport is specifically impaired by the Y1087C mutation of KIF1Bβ, which we detected in hereditary neuropathic patients. The axonal outgrowth and IGF-I signaling of Kif1b−/− neurons were significantly impaired, consistent with decreased surface IGF1R expression. The complementary capacity of KIF1Bβ-Y1087C of these phenotypes was significantly impaired, but the binding capacity to synaptic vesicle precursors was not affected. These data have supported the relevance of KIF1Bβ in IGF1R transport, which may give new clue to the neuropathic pathogenesis.
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Affiliation(s)
- Fang Xu
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Hironori Takahashi
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yosuke Tanaka
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Sotaro Ichinose
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shinsuke Niwa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Nobutaka Hirokawa
- Department of Cell Biology and Anatomy, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan .,Center of Excellence in Genome Medicine Research, King Abdulaziz University, Jeddah, Saudi Arabia
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49
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Sarasija S, Laboy JT, Ashkavand Z, Bonner J, Tang Y, Norman KR. Presenilin mutations deregulate mitochondrial Ca 2+ homeostasis and metabolic activity causing neurodegeneration in Caenorhabditis elegans. eLife 2018; 7:33052. [PMID: 29989545 PMCID: PMC6075864 DOI: 10.7554/elife.33052] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 07/09/2018] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction and subsequent metabolic deregulation is observed in neurodegenerative diseases and aging. Mutations in the presenilin (PSEN) encoding genes (PSEN1 and PSEN2) cause most cases of familial Alzheimer’s disease (AD); however, the underlying mechanism of pathogenesis remains unclear. Here, we show that mutations in the C. elegans gene encoding a PSEN homolog, sel-12 result in mitochondrial metabolic defects that promote neurodegeneration as a result of oxidative stress. In sel-12 mutants, elevated endoplasmic reticulum (ER)-mitochondrial Ca2+ signaling leads to an increase in mitochondrial Ca2+ content which stimulates mitochondrial respiration resulting in an increase in mitochondrial superoxide production. By reducing ER Ca2+ release, mitochondrial Ca2+ uptake or mitochondrial superoxides in sel-12 mutants, we demonstrate rescue of the mitochondrial metabolic defects and prevent neurodegeneration. These data suggest that mutations in PSEN alter mitochondrial metabolic function via ER to mitochondrial Ca2+ signaling and provide insight for alternative targets for treating neurodegenerative diseases. Alzheimer's disease is the most common type of dementia. A hallmark of this condition is progressive loss of memory, accompanied by a buildup of hard clumps of protein between the brain cells. These protein clumps, known as amyloid plaques, are a key focus of research into Alzheimer's disease. They are likely to be toxic to brain cells, but their role in the development and progression of the disease is not yet known. Though the cause of Alzheimer's disease remains unclear, an inherited form of the disease may hold some clues. Mutations in genes for proteins called presenilins cause an earlier onset form of Alzheimer's disease, in which symptoms can develop in people who are in their 40s or 50s. The presenilin proteins appear in a cell structure called the endoplasmic reticulum, which plays many roles in the normal activities of a cell. Among other things, this structure stores and releases calcium ions, and cells use these ions to send and process many signals. The cell's energy-producing powerhouses, the mitochondria, use calcium to boost their metabolic activity. This allows them to make more energy for the cell, but in the process they also make damaging byproducts. These byproducts include oxygen-containing chemicals, known as reactive oxygen species (ROS), which react strongly with other molecules. While low levels of ROS are a normal part of cell activity, if the levels get too high, these chemicals can attack and damage structures within the cell. Untangling the effects of amyloid plaques and presenilins on brain cells in humans is challenging. But, a nematode worm called Caenorhabditis elegans does not form plaques, making it possible to look at presenilins on their own. Previous work in these worms has shown that presenilin mutations affect the endoplasmic reticulum and change the appearance of mitochondria. Here, Sarasija et al. extend this work to find out more about the effects presenilin mutations have on living cells. Presenilin mutations in young adult worms increased the amount of calcium released by the endoplasmic reticulum. This increased the activity of the mitochondria and caused ROS levels to rise to damaging levels. This caused stress inside the cells, and the worms started to show early signs damage to their nervous systems. Mutations that decreased the movement of calcium from the endoplasmic reticulum to the mitochondria helped to prevent the damage. Treating the mitochondria with antioxidants to mop up the extra ROS also protected the cells. This kind of damage to brain cells did not depend on amyloid plaques. Whilst the plaques are likely to be toxic, these new findings highlights the role that other chemical and biological processes might play in Alzheimer's disease. Further work to reveal the underlying cause of Alzheimer's disease may lead to new therapies to treat this condition in the future.
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Affiliation(s)
- Shaarika Sarasija
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Jocelyn T Laboy
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Zahra Ashkavand
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Jennifer Bonner
- Department of Biology, Skidmore College, Saratoga Springs, United States
| | - Yi Tang
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
| | - Kenneth R Norman
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, United States
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50
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Li D, Li F, Guttipatti P, Song Y. A Drosophila In Vivo Injury Model for Studying Neuroregeneration in the Peripheral and Central Nervous System. J Vis Exp 2018:57557. [PMID: 29781994 PMCID: PMC6101115 DOI: 10.3791/57557] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The regrowth capacity of damaged neurons governs neuroregeneration and functional recovery after nervous system trauma. Over the past few decades, various intrinsic and extrinsic inhibitory factors involved in the restriction of axon regeneration have been identified. However, simply removing these inhibitory cues is insufficient for successful regeneration, indicating the existence of additional regulatory machinery. Drosophila melanogaster, the fruit fly, shares evolutionarily conserved genes and signaling pathways with vertebrates, including humans. Combining the powerful genetic toolbox of flies with two-photon laser axotomy/dendriotomy, we describe here the Drosophila sensory neuron - dendritic arborization (da) neuron injury model as a platform for systematically screening for novel regeneration regulators. Briefly, this paradigm includes a) the preparation of larvae, b) lesion induction to dendrite(s) or axon(s) using a two-photon laser, c) live confocal imaging post-injury and d) data analysis. Our model enables highly reproducible injury of single labeled neurons, axons, and dendrites of well-defined neuronal subtypes, in both the peripheral and central nervous system.
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Affiliation(s)
- Dan Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia
| | - Feng Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia
| | - Pavithran Guttipatti
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia
| | - Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia; Department of Pathology and Laboratory Medicine, University of Pennsylvania;
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