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Chen J, Chen J, Yu C, Xia K, Yang B, Wang R, Li Y, Shi K, Zhang Y, Xu H, Zhang X, Wang J, Chen Q, Liang C. Metabolic reprogramming: a new option for the treatment of spinal cord injury. Neural Regen Res 2025; 20:1042-1057. [PMID: 38989936 DOI: 10.4103/nrr.nrr-d-23-01604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 02/27/2024] [Indexed: 07/12/2024] Open
Abstract
Spinal cord injuries impose a notably economic burden on society, mainly because of the severe after-effects they cause. Despite the ongoing development of various therapies for spinal cord injuries, their effectiveness remains unsatisfactory. However, a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic reprogramming. In this review, we explore the metabolic changes that occur during spinal cord injuries, their consequences, and the therapeutic tools available for metabolic reprogramming. Normal spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic coupling. However, spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism, lipid metabolism, and mitochondrial dysfunction. These metabolic disturbances lead to corresponding pathological changes, including the failure of axonal regeneration, the accumulation of scarring, and the activation of microglia. To rescue spinal cord injury at the metabolic level, potential metabolic reprogramming approaches have emerged, including replenishing metabolic substrates, reconstituting metabolic couplings, and targeting mitochondrial therapies to alter cell fate. The available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord injury. To further advance the metabolic treatment of the spinal cord injury, future efforts should focus on a deeper understanding of neurometabolism, the development of more advanced metabolomics technologies, and the design of highly effective metabolic interventions.
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Affiliation(s)
- Jiangjie Chen
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Jinyang Chen
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Chao Yu
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Kaishun Xia
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Biao Yang
- Qiandongnan Prefecture People's Hospital, Kaili, Guizhou Province, China
| | - Ronghao Wang
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Yi Li
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Kesi Shi
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Yuang Zhang
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Haibin Xu
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Xuesong Zhang
- Department of Orthopedics, Fourth Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Jingkai Wang
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Qixin Chen
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
| | - Chengzhen Liang
- Department of Orthopedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- Orthopedics Research Institute of Zhejiang University, Zhejiang University, Hangzhou, Zhejiang Province, China
- Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province, Hangzhou, Zhejiang Province, China
- Clinical Research Center of Motor System Disease of Zhejiang Province, Hangzhou, Zhejiang Province, China
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Duarte VN, Lam VT, Rimicci DS, Thompson-Peer KL. Calcium plays an essential role in early-stage dendrite injury detection and regeneration. Prog Neurobiol 2024; 239:102635. [PMID: 38825174 DOI: 10.1016/j.pneurobio.2024.102635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 05/21/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
Dendrites are injured in a variety of clinical conditions such as traumatic brain and spinal cord injuries and stroke. How neurons detect injury directly to their dendrites to initiate a pro-regenerative response has not yet been thoroughly investigated. Calcium plays a critical role in the early stages of axonal injury detection and is also indispensable for regeneration of the severed axon. Here, we report cell and neurite type-specific differences in laser injury-induced elevations of intracellular calcium levels. Using a human KCNJ2 transgene, we demonstrate that hyperpolarizing neurons only at the time of injury dampens dendrite regeneration, suggesting that inhibition of injury-induced membrane depolarization (and thus early calcium influx) plays a role in detecting and responding to dendrite injury. In exploring potential downstream calcium-regulated effectors, we identify L-type voltage-gated calcium channels, inositol triphosphate signaling, and protein kinase D activity as drivers of dendrite regeneration. In conclusion, we demonstrate that dendrite injury-induced calcium elevations play a key role in the regenerative response of dendrites and begin to delineate the molecular mechanisms governing dendrite repair.
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Affiliation(s)
- Vinicius N Duarte
- Dept of Developmental and Cell Biology, University of California, Irvine, United States
| | - Vicky T Lam
- Dept of Developmental and Cell Biology, University of California, Irvine, United States
| | - Dario S Rimicci
- Dept of Developmental and Cell Biology, University of California, Irvine, United States
| | - Katherine L Thompson-Peer
- Dept of Developmental and Cell Biology, University of California, Irvine, United States; Center for the Neurobiology of Learning and Memory, Irvine, CA, United States; Sue and Bill Gross Stem Cell Research Center, Irvine, CA, United States; Reeve-Irvine Research Center, Irvine, CA, United States.
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3
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Li M, Xu J, Zou Y, Lu J, Ou A, Ma X, Zhang J, Xu Y, Fu L, Liu J, Wang X, Zhou L, Guo J. Motor neuron-specific RhoA knockout delays degeneration and promotes regeneration of dendrites in spinal ventral horn after brachial plexus injury. Neural Regen Res 2023; 18:2757-2761. [PMID: 37449641 DOI: 10.4103/1673-5374.373657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
Dendrites play irreplaceable roles in the nerve conduction pathway and are vulnerable to various insults. Peripheral axotomy of motor neurons results in the retraction of dendritic arbors, and the dendritic arbor can be re-expanded when reinnervation is allowed. RhoA is a target that regulates the cytoskeleton and promotes neuronal survival and axon regeneration. However, the role of RhoA in dendrite degeneration and regeneration is unknown. In this study, we explored the potential role of RhoA in dendrites. A line of motor neuronal RhoA conditional knockout mice was developed by crossbreeding HB9Cre+ mice with RhoAflox/flox mice. We established two models for assaying dendrite degeneration and regeneration, in which the brachial plexus was transection or crush injured, respectively. We found that at 28 days after brachial plexus transection, the density, complexity, and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice were slightly decreased compared with that in Cre mice. Dendrites underwent degeneration at 7 and 14 days after brachial plexus transection and recovered at 28-56 days. The density, complexity, and structural integrity of dendrites in the ventral horn of the spinal cord of RhoA conditional knockout mice recovered compared with results in Cre mice. These findings suggest that RhoA knockout in motor neurons attenuates dendrite degeneration and promotes dendrite regeneration after peripheral nerve injury.
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Affiliation(s)
- Mi Li
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jiawei Xu
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Ying Zou
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jialing Lu
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Aiyue Ou
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xinrui Ma
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jiaqi Zhang
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Yizhou Xu
- Department of Histology and Embryology, School of Basic Medical Sciences; Department of Spine Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Lanya Fu
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Jingmin Liu
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Xianghai Wang
- Department of Histology and Embryology, School of Basic Medical Sciences; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Guangzhou, Guangdong Province, China
| | - Libing Zhou
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, Guangdong Province, China
| | - Jiasong Guo
- Department of Histology and Embryology, School of Basic Medical Sciences; Department of Spine Orthopedics, Zhujiang Hospital; Guangdong Provincial Key Laboratory of Construction and Detection in Tissue Engineering, Southern Medical University; Key Laboratory of Mental Health of the Ministry of Education, Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangdong Province Key Laboratory of Psychiatric Disorders, Guangzhou, Guangdong Province, China
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Analysis of Axonal Regrowth and Dendritic Remodeling After Optic Nerve Crush in Adult Zebrafish. Methods Mol Biol 2023; 2636:163-190. [PMID: 36881300 DOI: 10.1007/978-1-0716-3012-9_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Neurodegenerative diseases and central nervous system (CNS) injuries are frequently characterized by axonal damage, as well as dendritic pathology. In contrast to mammals, adult zebrafish show a robust regeneration capacity after CNS injury and form the ideal model organism to further unravel the underlying mechanisms for both axonal and dendritic regrowth upon CNS damage. Here, we first describe an optic nerve crush injury model in adult zebrafish, an injury paradigm that inflicts de- and regeneration of the axons of retinal ganglion cells (RGCs), but also triggers RGC dendrite disintegration and subsequent recovery in a stereotyped and timed process. Next, we outline protocols for quantifying axonal regeneration and synaptic recovery in the brain, using retro- and anterograde tracing experiments and an immunofluorescent staining for presynaptic compartments, respectively. Finally, methods to analyze RGC dendrite retraction and subsequent regrowth in the retina are delineated, using morphological measurements and immunofluorescent staining for dendritic and synaptic markers.
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Adula KP, Shorey M, Chauhan V, Nassman K, Chen SF, Rolls MM, Sagasti A. The MAP3Ks DLK and LZK Direct Diverse Responses to Axon Damage in Zebrafish Peripheral Neurons. J Neurosci 2022; 42:6195-6210. [PMID: 35840323 PMCID: PMC9374156 DOI: 10.1523/jneurosci.1395-21.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 06/14/2022] [Accepted: 06/27/2022] [Indexed: 11/21/2022] Open
Abstract
Mitogen-activated protein kinase kinase kinases (MAP3Ks) dual leucine kinase (DLK) and leucine zipper kinase (LZK) are essential mediators of axon damage responses, but their responses are varied, complex, and incompletely understood. To characterize their functions in axon injury, we generated zebrafish mutants of each gene, labeled motor neurons (MNs) and touch-sensing neurons in live zebrafish, precisely cut their axons with a laser, and assessed the ability of mutant axons to regenerate in larvae, before sex is apparent in zebrafish. DLK and LZK were required redundantly and cell autonomously for axon regeneration in MNs but not in larval Rohon-Beard (RB) or adult dorsal root ganglion (DRG) sensory neurons. Surprisingly, in dlk lzk double mutants, the spared branches of wounded RB axons grew excessively, suggesting that these kinases inhibit regenerative sprouting in damaged axons. Uninjured trigeminal sensory axons also grew excessively in mutants when neighboring neurons were ablated, indicating that these MAP3Ks are general inhibitors of sensory axon growth. These results demonstrate that zebrafish DLK and LZK promote diverse injury responses, depending on the neuronal cell identity and type of axonal injury.SIGNIFICANCE STATEMENT The MAP3Ks DLK and LZK are damage sensors that promote diverse outcomes to neuronal injury, including axon regeneration. Understanding their context-specific functions is a prerequisite to considering these kinases as therapeutic targets. To investigate DLK and LZK cell-type-specific functions, we created zebrafish mutants in each gene. Using mosaic cell labeling and precise laser injury we found that both proteins were required for axon regeneration in motor neurons but, unexpectedly, were not required for axon regeneration in Rohon-Beard or DRG sensory neurons and negatively regulated sprouting in the spared axons of touch-sensing neurons. These findings emphasize that animals have evolved distinct mechanisms to regulate injury site regeneration and collateral sprouting, and identify differential roles for DLK and LZK in these processes.
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Affiliation(s)
- Kadidia Pemba Adula
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Matthew Shorey
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Vasudha Chauhan
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Khaled Nassman
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Shu-Fan Chen
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Melissa M Rolls
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Alvaro Sagasti
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095,
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6
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Zhang Q, Li Y, Zhuo Y. Synaptic or Non-synaptic? Different Intercellular Interactions with Retinal Ganglion Cells in Optic Nerve Regeneration. Mol Neurobiol 2022; 59:3052-3072. [PMID: 35266115 PMCID: PMC9016027 DOI: 10.1007/s12035-022-02781-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 02/24/2022] [Indexed: 12/31/2022]
Abstract
Axons of adult neurons in the mammalian central nervous system generally fail to regenerate by themselves, and few if any therapeutic options exist to reverse this situation. Due to a weak intrinsic potential for axon growth and the presence of strong extrinsic inhibitors, retinal ganglion cells (RGCs) cannot regenerate their axons spontaneously after optic nerve injury and eventually undergo apoptosis, resulting in permanent visual dysfunction. Regarding the extracellular environment, research to date has generally focused on glial cells and inflammatory cells, while few studies have discussed the potentially significant role of interneurons that make direct connections with RGCs as part of the complex retinal circuitry. In this study, we provide a novel angle to summarize these extracellular influences following optic nerve injury as "intercellular interactions" with RGCs and classify these interactions as synaptic and non-synaptic. By discussing current knowledge of non-synaptic (glial cells and inflammatory cells) and synaptic (mostly amacrine cells and bipolar cells) interactions, we hope to accentuate the previously neglected but significant effects of pre-synaptic interneurons and bring unique insights into future pursuit of optic nerve regeneration and visual function recovery.
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Affiliation(s)
- Qi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Yiqing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-Sen University, Guangzhou, 510060, China.
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-Sen University, Guangzhou, 510060, China.
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7
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Gao T, Deng B, Wang J, Wang J, Yi G. The passive properties of dendrites modulate the propagation of slowly-varying firing rate in feedforward networks. Neural Netw 2022; 150:377-391. [DOI: 10.1016/j.neunet.2022.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/12/2022] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
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Beckers A, Vanhunsel S, Van Dyck A, Bergmans S, Masin L, Moons L. Injury-induced Autophagy Delays Axonal Regeneration after Optic Nerve Damage in Adult Zebrafish. Neuroscience 2021; 470:52-69. [PMID: 34280491 DOI: 10.1016/j.neuroscience.2021.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/18/2021] [Accepted: 07/09/2021] [Indexed: 12/15/2022]
Abstract
Optic neuropathies comprise a group of disorders in which the axons of retinal ganglion cells (RGCs), the retinal projection neurons conveying visual information to the brain, are damaged. This results in visual impairment or even blindness, which is irreversible as adult mammals lack the capacity to repair or replace injured or lost neurons. Despite intensive research, no efficient treatment to induce axonal regeneration in the central nervous system (CNS) is available yet. Autophagy, the cellular recycling response, was shown repeatedly to be elevated in animal models of optic nerve injury, and both beneficial and detrimental effects have been reported. In this study, we subjected spontaneously regenerating adult zebrafish to optic nerve damage (ONC) and revealed that autophagy is enhanced after optic nerve damage in zebrafish, both in RGC axons and somas, as well as in macroglial cells of the retina, the optic nerve and the visual target areas in the brain. Interestingly, the pattern of the autophagic response in the axons followed the spatiotemporal window of axonal regrowth, which suggests that autophagy is ongoing at the growth cones. Pharmacological inhibition of the recycling pathway resulted in accelerated RGC target reinnervation, possibly linked to increased mechanistic target of rapamycin (mTOR) activity, known to stimulate axonal regrowth. Taken together, these intriguing findings underline that further research is warranted to decipher if modulation of autophagy could be an effective therapeutic method to induce CNS regeneration.
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Affiliation(s)
- An Beckers
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Sophie Vanhunsel
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Annelies Van Dyck
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Steven Bergmans
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Luca Masin
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lieve Moons
- Neural Circuit Development and Regeneration Research Group, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, 3000 Leuven, Belgium; Leuven Brain Institute, 3000 Leuven, Belgium.
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9
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Nye DMR, Albertson RM, Weiner AT, Hertzler JI, Shorey M, Goberdhan DCI, Wilson C, Janes KA, Rolls MM. The receptor tyrosine kinase Ror is required for dendrite regeneration in Drosophila neurons. PLoS Biol 2020; 18:e3000657. [PMID: 32163406 PMCID: PMC7067388 DOI: 10.1371/journal.pbio.3000657] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/07/2020] [Indexed: 12/13/2022] Open
Abstract
While many regulators of axon regeneration have been identified, very little is known about mechanisms that allow dendrites to regenerate after injury. Using a Drosophila model of dendrite regeneration, we performed a candidate screen of receptor tyrosine kinases (RTKs) and found a requirement for RTK-like orphan receptor (Ror). We confirmed that Ror was required for regeneration in two different neuron types using RNA interference (RNAi) and mutants. Ror was not required for axon regeneration or normal dendrite development, suggesting a specific role in dendrite regeneration. Ror can act as a Wnt coreceptor with frizzleds (fzs) in other contexts, so we tested the involvement of Wnt signaling proteins in dendrite regeneration. We found that knockdown of fz, dishevelled (dsh), Axin, and gilgamesh (gish) also reduced dendrite regeneration. Moreover, Ror was required to position dsh and Axin in dendrites. We recently found that Wnt signaling proteins, including dsh and Axin, localize microtubule nucleation machinery in dendrites. We therefore hypothesized that Ror may act by regulating microtubule nucleation at baseline and during dendrite regeneration. Consistent with this hypothesis, localization of the core nucleation protein γTubulin was reduced in Ror RNAi neurons, and this effect was strongest during dendrite regeneration. In addition, dendrite regeneration was sensitive to partial reduction of γTubulin. We conclude that Ror promotes dendrite regeneration as part of a Wnt signaling pathway that regulates dendritic microtubule nucleation.
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Affiliation(s)
- Derek M. R. Nye
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- MSTP Program, Milton S. Hershey College of Medicine, Hershey, Pennsylvania, United States of America
| | - Richard M. Albertson
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- MSTP Program, Milton S. Hershey College of Medicine, Hershey, Pennsylvania, United States of America
| | - Alexis T. Weiner
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - J. Ian Hertzler
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Matthew Shorey
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | | | - Clive Wilson
- Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Kevin A. Janes
- Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Melissa M. Rolls
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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10
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Schuster CJ, Kao RM. Glial cell ecology in zebrafish development and regeneration. Heliyon 2020; 6:e03507. [PMID: 32140606 PMCID: PMC7052072 DOI: 10.1016/j.heliyon.2020.e03507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 10/01/2019] [Accepted: 02/25/2020] [Indexed: 11/25/2022] Open
Abstract
Zebrafish have been found to be the premier model organism in biological and biomedical research, specifically offering many advantages in developmental biology and genetics. The zebrafish (Danio rerio) has the ability to regenerate its spinal cord after injury. However, the complete molecular and cellular mechanisms behind glial bridge formation in zebrafish remains unclear. In our review paper, we examine the extracellular and intracellular molecular signaling factors that control zebrafish glial cell bridging and glial cell development in the forebrain. The interplay between initiating and terminating molecular feedback cycles deserve future investigations during glial cell growth, movement, and differentiation.
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Tian ZR, Yao M, Zhou LY, Song YJ, Ye J, Wang YJ, Cui XJ. Effect of docosahexaenoic acid on the recovery of motor function in rats with spinal cord injury: a meta-analysis. Neural Regen Res 2020; 15:537-547. [PMID: 31571666 PMCID: PMC6921345 DOI: 10.4103/1673-5374.266065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Objective: Studies have shown that docosahexaenoic acid (DHA) has a beneficial effect in the treatment of spinal cord injury. A meta-analysis was used to study the effect of DHA on the neurological recovery in the rat spinal cord injury model, and the relationship between the recovery of motor function after spinal cord injury and the time and method of administration and the dose of DHA. Data source: Published studies on the effect of DHA on spinal cord injury animal models from seven databases were searched from their inception to January 2019, including PubMed, MEDLINE, EMBASE, the China National Knowledge Infrastructure, Wanfang, VIP, and SinoMed databases. The search terms included “spinal cord injury” “docosahexaenoic acid”, and “rats”. Data selection: Studies that evaluated the influence of DHA in rat models of spinal cord injury for locomotor functional recovery were included. The intervention group included any form of DHA treatment and the control group included treatment with normal saline, vehicle solution or no treatment. The Systematic Review Centre for Laboratory animal Experimentation’s risk of bias assessment tool was used for the quality assessment of the included studies. Literature inclusion, quality evaluation and data extraction were performed by two researchers. Meta-analysis was then conducted on all studies that met the inclusion criteria. Statistical analysis was performed on the data using RevMan 5.1.2. software. Outcome measures: The primary outcome measure was the score on the Basso, Beattie, and Bresnahan scale. Secondary outcome measures were the sloping plate test, balance beam test, stair test and grid exploration test. Results: A total of 12 related studies were included, 3 of which were of higher quality and the remaining 9 were of lower quality. The highest mean Basso, Beattie, and Bresnahan scale score occurred at 42 days after DHA treatment in spinal cord injury rats. At 21 days after treatment, the mean difference in Basso, Beattie, Bresnahan scores between the DHA group and the control group was the most significant (pooled MD = 4.14; 95% CI = 3.58–4.70; P < 0.00001). In the subgroup analysis, improvement in the Basso, Beattie, and Bresnahan scale score was more significant in rats administered DHA intravenously (pooled MD = 2.74; 95% CI = 1.41–4.07; P < 0.0001) and subcutaneously (pooled MD = 2.99; 95% CI = 2.29–3.69; P < 0.00001) than in the groups administered DHA orally (pooled MD = 3.04; 95% CI = –1.01 to 7.09; P = 0.14). Intravenous injection of DHA at 250 nmol/kg (pooled MD = 2.94; 95% CI = 2.47–3.41; P < 0.00001] and 1000 nmol/kg [pooled MD = 3.60; 95% CI = 2.66–4.54; P < 0.00001) significantly improved the Basso, Beattie, and Bresnahan scale score in rats and promoted the recovery of motor function. Conclusion: DHA can promote motor functional recovery after spinal cord injury in rats. The administration of DHA by intravenous or subcutaneous injection is more effective than oral administration of DHA. Intravenous injection of DHA at doses of 250 nmol/kg or 1000 nmol/kg is beneficial. Because of the small number and the low quality of the included studies, more high-quality research is needed in future to substantiate the results.
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Affiliation(s)
- Zi-Rui Tian
- Institute of Spine Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education (Shanghai University of Traditional Chinese Medicine); Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Min Yao
- Institute of Spine Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education (Shanghai University of Traditional Chinese Medicine), Shanghai, China
| | - Long-Yun Zhou
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education (Shanghai University of Traditional Chinese Medicine); Shanghai University of Traditional Chinese Medicine; Rehabilitation Medicine College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-Jia Song
- Institute of Spine Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education (Shanghai University of Traditional Chinese Medicine); Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jie Ye
- Department of Orthopedics and Traumatology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yong-Jun Wang
- Institute of Spine Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education (Shanghai University of Traditional Chinese Medicine); Shanghai University of Traditional Chinese Medicine; Rehabilitation Medicine College, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xue-Jun Cui
- Institute of Spine Disease, Longhua Hospital, Shanghai University of Traditional Chinese Medicine; Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education (Shanghai University of Traditional Chinese Medicine), Shanghai, China
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