1
|
Izhiman Y, Esfandiari L. Emerging role of extracellular vesicles and exogenous stimuli in molecular mechanisms of peripheral nerve regeneration. Front Cell Neurosci 2024; 18:1368630. [PMID: 38572074 PMCID: PMC10989355 DOI: 10.3389/fncel.2024.1368630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/29/2024] [Indexed: 04/05/2024] Open
Abstract
Peripheral nerve injuries lead to significant morbidity and adversely affect quality of life. The peripheral nervous system harbors the unique trait of autonomous regeneration; however, achieving successful regeneration remains uncertain. Research continues to augment and expedite successful peripheral nerve recovery, offering promising strategies for promoting peripheral nerve regeneration (PNR). These include leveraging extracellular vesicle (EV) communication and harnessing cellular activation through electrical and mechanical stimulation. Small extracellular vesicles (sEVs), 30-150 nm in diameter, play a pivotal role in regulating intercellular communication within the regenerative cascade, specifically among nerve cells, Schwann cells, macrophages, and fibroblasts. Furthermore, the utilization of exogenous stimuli, including electrical stimulation (ES), ultrasound stimulation (US), and extracorporeal shock wave therapy (ESWT), offers remarkable advantages in accelerating and augmenting PNR. Moreover, the application of mechanical and electrical stimuli can potentially affect the biogenesis and secretion of sEVs, consequently leading to potential improvements in PNR. In this review article, we comprehensively delve into the intricacies of cell-to-cell communication facilitated by sEVs and the key regulatory signaling pathways governing PNR. Additionally, we investigated the broad-ranging impacts of ES, US, and ESWT on PNR.
Collapse
Affiliation(s)
- Yara Izhiman
- Esfandiari Laboratory, Department of Biomedical Engineering, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Leyla Esfandiari
- Esfandiari Laboratory, Department of Biomedical Engineering, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, United States
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, OH, United States
- Department of Electrical and Computer Engineering, College of Engineering and Applied Sciences, University of Cincinnati, Cincinnati, OH, United States
| |
Collapse
|
2
|
Wang X, Li W, Zhang J, Li J, Zhang X, Wang M, Wei Z, Feng S. Discovery of therapeutic targets for spinal cord injury based on molecular mechanisms of axon regeneration after conditioning lesion. J Transl Med 2023; 21:511. [PMID: 37507810 PMCID: PMC10385911 DOI: 10.1186/s12967-023-04375-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 07/20/2023] [Indexed: 07/30/2023] Open
Abstract
BACKGROUND Preinjury of peripheral nerves triggers dorsal root ganglia (DRG) axon regeneration, a biological change that is more pronounced in young mice than in old mice, but the complex mechanism has not been clearly explained. Here, we aim to gain insight into the mechanisms of axon regeneration after conditioning lesion in different age groups of mice, thereby providing effective therapeutic targets for central nervous system (CNS) injury. METHODS The microarray GSE58982 and GSE96051 were downloaded and analyzed to identify differentially expressed genes (DEGs). The protein-protein interaction (PPI) network, the miRNA-TF-target gene network, and the drug-hub gene network of conditioning lesion were constructed. The L4 and L5 DRGs, which were previously axotomized by the sciatic nerve conditioning lesions, were harvested for qRT-PCR. Furthermore, histological and behavioral tests were performed to assess the therapeutic effects of the candidate drug telmisartan in spinal cord injury (SCI). RESULTS A total of 693 and 885 DEGs were screened in the old and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in the inflammatory response, innate immune response, and ion transport. QRT-PCR results showed that in DRGs with preinjury of peripheral nerve, Timp1, P2ry6, Nckap1l, Csf1, Ccl9, Anxa1, and C3 were upregulated, while Agtr1a was downregulated. Based on the bioinformatics analysis of DRG after conditioning lesion, Agtr1a was selected as a potential therapeutic target for the SCI treatment. In vivo experiments showed that telmisartan promoted axonal regeneration after SCI by downregulating AGTR1 expression. CONCLUSION This study provides a comprehensive map of transcriptional changes that discriminate between young and old DRGs in response to injury. The hub genes and their related drugs that may affect the axonal regeneration program after conditioning lesion were identified. These findings revealed the speculative pathogenic mechanism involved in conditioning-dependent regenerative growth and may have translational significance for the development of CNS injury treatment in the future.
Collapse
Affiliation(s)
- Xiaoxiong Wang
- Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, Shandong, China
- Shandong University Centre for Orthopaedics, Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, People's Republic of China
- University of Health and Rehabilitation Sciences, No.17, Shandong Road, Shinan District, Qingdao, 266071, Shandong, People's Republic of China
| | - Wenxiang Li
- Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, Shandong, China
- Shandong University Centre for Orthopaedics, Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, People's Republic of China
| | - Jianping Zhang
- International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin Key Laboratory of Spine and Spinal Cord, Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Jinze Li
- International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin Key Laboratory of Spine and Spinal Cord, Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Xianjin Zhang
- International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin Key Laboratory of Spine and Spinal Cord, Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Min Wang
- Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin, 300052, People's Republic of China
| | - Zhijian Wei
- Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, Shandong, China.
- Shandong University Centre for Orthopaedics, Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, People's Republic of China.
- International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin Key Laboratory of Spine and Spinal Cord, Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.
- Department of Orthopedics, Tianjin Medical University General Hospital, No154. Anshan Rd, He Ping Dist, Tianjin, 300052, China.
| | - Shiqing Feng
- Department of Orthopedics, Qilu Hospital of Shandong University, Jinan, Shandong, China.
- Shandong University Centre for Orthopaedics, Advanced Medical Research Institute, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, People's Republic of China.
- International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin Key Laboratory of Spine and Spinal Cord, Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, People's Republic of China.
- Department of Orthopedics, Tianjin Medical University General Hospital, No154. Anshan Rd, He Ping Dist, Tianjin, 300052, China.
| |
Collapse
|
3
|
Khaitin A. Calcium in Neuronal and Glial Response to Axotomy. Int J Mol Sci 2021; 22:ijms222413344. [PMID: 34948141 PMCID: PMC8706492 DOI: 10.3390/ijms222413344] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/16/2022] Open
Abstract
Neurotrauma assumes an instant or delayed disconnection of axons (axotomy), which affects not only neurons, but surrounding glia as well. Not only mechanically injured glia near the site of disconnection, especially transection, is subjected to the damage, but also glia that is remote from the lesion site. Glial cells, which surround the neuronal body, in turn, support neuron survival, so there is a mutual protection between neuron and glia. Calcium signaling is a central mediator of all post-axotomy events, both in neuron and glia, playing a critical role in their survival/regeneration or death/degeneration. The involvement of calcium in post-axotomy survival of the remote, mechanically intact glia is poorly studied. The purpose of this review is to sum up the calcium-involving mechanisms in responses of neurons and glial cells to axotomy to show their importance and to give some suggestions for future research of remote glia in this context.
Collapse
Affiliation(s)
- Andrey Khaitin
- Academy of Biology and Biotechnology, Southern Federal University, 344090 Rostov-on-Don, Russia
| |
Collapse
|
4
|
Yehuda B, Gradus Pery T, Ophir E, Blumenfeld-Katzir T, Sheinin A, Alon Y, Danino N, Perlson E, Nevo U. Neuronal Activity in the Sciatic Nerve Is Accompanied by Immediate Cytoskeletal Changes. Front Mol Neurosci 2021; 14:757264. [PMID: 34776865 PMCID: PMC8579013 DOI: 10.3389/fnmol.2021.757264] [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: 08/11/2021] [Accepted: 10/04/2021] [Indexed: 11/19/2022] Open
Abstract
Mechanical events and alterations in neuronal morphology that accompany neuronal activity have been observed for decades. However, no clear neurophysiological role, nor an agreed molecular mechanism relating these events to the electrochemical process, has been found. Here we hypothesized that intense, yet physiological, electrical activity in neurons triggers cytoskeletal depolymerization. We excited the sciatic nerve of anesthetized mice with repetitive electric pulses (5, 10, and 100 Hz) for 1 and 2 min and immediately fixed the excised nerves. We then scanned the excised nerves with high-resolution transmission electron microscopy, and quantified cytoskeletal changes in the resulting micrographs. We demonstrate that excitation with a stimulation frequency that is within the physiological regime is accompanied by a significant reduction in the density of cytoskeletal proteins relative to the baseline values recorded in control nerves. After 10 Hz stimulation with durations of 1 and 2 min, neurofilaments density dropped to 55.8 and 51.1% of the baseline median values, respectively. In the same experiments, microtubules density dropped to 23.7 and 38.5% of the baseline median values, respectively. These changes were also accompanied by a reduction in the cytoskeleton-to-cytoplasm contrast that we attribute to the presence of depolymerized electron-dense molecules in the lumen. Thus, we demonstrate with an in vivo model a link between electrical activity and immediate cytoskeleton rearrangement at the nano-scale. We suggest that this cytoskeletal plasticity reduces cellular stiffness and allows cellular homeostasis, maintenance of neuronal morphology and that it facilitates in later stages growth of the neuronal projections.
Collapse
Affiliation(s)
- Bossmat Yehuda
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Tal Gradus Pery
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Efrat Ophir
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Tamar Blumenfeld-Katzir
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Anton Sheinin
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Yael Alon
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Noy Danino
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Eran Perlson
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Uri Nevo
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| |
Collapse
|
5
|
Bodakuntla S, Nedozralova H, Basnet N, Mizuno N. Cytoskeleton and Membrane Organization at Axon Branches. Front Cell Dev Biol 2021; 9:707486. [PMID: 34540830 PMCID: PMC8440873 DOI: 10.3389/fcell.2021.707486] [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: 05/10/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
Axon branching is a critical process ensuring a high degree of interconnectivity for neural network formation. As branching occurs at sites distant from the soma, it is necessary that axons have a local system to dynamically control and regulate axonal growth. This machinery depends on the orchestration of cellular functions such as cytoskeleton, subcellular transport, energy production, protein- and membrane synthesis that are adapted for branch formation. Compared to the axon shaft, branching sites show a distinct and dynamic arrangement of cytoskeleton components, endoplasmic reticulum and mitochondria. This review discusses the regulation of axon branching in the context of cytoskeleton and membrane remodeling.
Collapse
Affiliation(s)
- Satish Bodakuntla
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Hana Nedozralova
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Nirakar Basnet
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Naoko Mizuno
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, United States.,National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| |
Collapse
|
6
|
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.
Collapse
|
7
|
Axonal Organelles as Molecular Platforms for Axon Growth and Regeneration after Injury. Int J Mol Sci 2021; 22:ijms22041798. [PMID: 33670312 PMCID: PMC7918155 DOI: 10.3390/ijms22041798] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/06/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
Investigating the molecular mechanisms governing developmental axon growth has been a useful approach for identifying new strategies for boosting axon regeneration after injury, with the goal of treating debilitating conditions such as spinal cord injury and vision loss. The picture emerging is that various axonal organelles are important centers for organizing the molecular mechanisms and machinery required for growth cone development and axon extension, and these have recently been targeted to stimulate robust regeneration in the injured adult central nervous system (CNS). This review summarizes recent literature highlighting a central role for organelles such as recycling endosomes, the endoplasmic reticulum, mitochondria, lysosomes, autophagosomes and the proteasome in developmental axon growth, and describes how these organelles can be targeted to promote axon regeneration after injury to the adult CNS. This review also examines the connections between these organelles in developing and regenerating axons, and finally discusses the molecular mechanisms within the axon that are required for successful axon growth.
Collapse
|
8
|
Lee B, Cho Y. Experimental Model Systems for Understanding Human Axonal Injury Responses. Int J Mol Sci 2021; 22:E474. [PMID: 33418850 PMCID: PMC7824864 DOI: 10.3390/ijms22020474] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/03/2020] [Accepted: 12/30/2020] [Indexed: 12/26/2022] Open
Abstract
Neurons are structurally unique and have dendrites and axons that are vulnerable to injury. Some neurons in the peripheral nervous system (PNS) can regenerate their axons after injuries. However, most neurons in the central nervous system (CNS) fail to do so, resulting in irreversible neurological disorders. To understand the mechanisms of axon regeneration, various experimental models have been utilized in vivo and in vitro. Here, we collate the key experimental models that revealed the important mechanisms regulating axon regeneration and degeneration in different systems. We also discuss the advantages of experimenting with the rodent model, considering the application of these findings in understanding human diseases and for developing therapeutic methods.
Collapse
Affiliation(s)
| | - Yongcheol Cho
- Laboratory of Axon Regeneration & Degeneration, Department of Life Sciences, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Korea;
| |
Collapse
|
9
|
Sahoo PK, Kar AN, Samra N, Terenzio M, Patel P, Lee SJ, Miller S, Thames E, Jones B, Kawaguchi R, Coppola G, Fainzilber M, Twiss JL. A Ca 2+-Dependent Switch Activates Axonal Casein Kinase 2α Translation and Drives G3BP1 Granule Disassembly for Axon Regeneration. Curr Biol 2020; 30:4882-4895.e6. [PMID: 33065005 DOI: 10.1016/j.cub.2020.09.043] [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] [Received: 11/14/2019] [Revised: 07/15/2020] [Accepted: 09/14/2020] [Indexed: 12/20/2022]
Abstract
The main limitation on axon regeneration in the peripheral nervous system (PNS) is the slow rate of regrowth. We recently reported that nerve regeneration can be accelerated by axonal G3BP1 granule disassembly, releasing axonal mRNAs for local translation to support axon growth. Here, we show that G3BP1 phosphorylation by casein kinase 2α (CK2α) triggers G3BP1 granule disassembly in injured axons. CK2α activity is temporally and spatially regulated by local translation of Csnk2a1 mRNA in axons after injury, but this requires local translation of mTor mRNA and buffering of the elevated axonal Ca2+ that occurs after axotomy. CK2α's appearance in axons after PNS nerve injury correlates with disassembly of axonal G3BP1 granules as well as increased phospho-G3BP1 and axon growth, although depletion of Csnk2a1 mRNA from PNS axons decreases regeneration and increases G3BP1 granules. Phosphomimetic G3BP1 shows remarkably decreased RNA binding in dorsal root ganglion (DRG) neurons compared with wild-type and non-phosphorylatable G3BP1; combined with other studies, this suggests that CK2α-dependent G3BP1 phosphorylation on Ser 149 after axotomy releases axonal mRNAs for translation. Translation of axonal mRNAs encoding some injury-associated proteins is known to be increased with Ca2+ elevations, and using a dual fluorescence recovery after photobleaching (FRAP) reporter assay for axonal translation, we see that translational specificity switches from injury-associated protein mRNA translation to CK2α translation with endoplasmic reticulum (ER) Ca2+ release versus cytoplasmic Ca2+ chelation. Our results point to axoplasmic Ca2+ concentrations as a determinant for the temporal specificity of sequential translational activation of different axonal mRNAs as severed axons transition from injury to regenerative growth.
Collapse
Affiliation(s)
- Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Nitzan Samra
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovat, Israel
| | - Marco Terenzio
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovat, Israel; Molecular Neuroscience Unit, Okinawa Institute of Science and Technology, Kunigami, Okinawa 904-0412, Japan
| | - Priyanka Patel
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Seung Joon Lee
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Sharmina Miller
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Elizabeth Thames
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Blake Jones
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Riki Kawaguchi
- Department of Neurology, Semel Institute for Neuroscience and Human Behavior, Los Angeles, CA 90095-1761, USA
| | - Giovanni Coppola
- Department of Neurology, Semel Institute for Neuroscience and Human Behavior, Los Angeles, CA 90095-1761, USA
| | - Mike Fainzilber
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovat, Israel
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA.
| |
Collapse
|
10
|
Rigoni M, Negro S. Signals Orchestrating Peripheral Nerve Repair. Cells 2020; 9:E1768. [PMID: 32722089 PMCID: PMC7464993 DOI: 10.3390/cells9081768] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/19/2020] [Accepted: 07/20/2020] [Indexed: 12/22/2022] Open
Abstract
The peripheral nervous system has retained through evolution the capacity to repair and regenerate after assault from a variety of physical, chemical, or biological pathogens. Regeneration relies on the intrinsic abilities of peripheral neurons and on a permissive environment, and it is driven by an intense interplay among neurons, the glia, muscles, the basal lamina, and the immune system. Indeed, extrinsic signals from the milieu of the injury site superimpose on genetic and epigenetic mechanisms to modulate cell intrinsic programs. Here, we will review the main intrinsic and extrinsic mechanisms allowing severed peripheral axons to re-grow, and discuss some alarm mediators and pro-regenerative molecules and pathways involved in the process, highlighting the role of Schwann cells as central hubs coordinating multiple signals. A particular focus will be provided on regeneration at the neuromuscular junction, an ideal model system whose manipulation can contribute to the identification of crucial mediators of nerve re-growth. A brief overview on regeneration at sensory terminals is also included.
Collapse
Affiliation(s)
- Michela Rigoni
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy;
- Myology Center (Cir-Myo), University of Padua, 35129 Padua, Italy
| | - Samuele Negro
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy;
| |
Collapse
|
11
|
Lizarraga-Valderrama LR, Nigmatullin R, Ladino B, Taylor CS, Boccaccini AR, Knowles JC, Claeyssens F, Haycock JW, Roy I. Modulation of neuronal cell affinity of composite scaffolds based on polyhydroxyalkanoates and bioactive glasses. ACTA ACUST UNITED AC 2020; 15:045024. [PMID: 32100724 DOI: 10.1088/1748-605x/ab797b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The biocompatibility and neuron regenerating properties of various bioactive glass (BG)/polyhydroxyalkanoate (PHA) blend composites were assessed in order to study their suitability for peripheral nerve tissue applications, specifically as lumen structures for nerve guidance conduits. BG/PHA blend composites were fabricated using Bioactive glass® 45 S5 (BG1) and BG 1393 (BG2) with the 25:75 poly(3-hydroxyoctanoate/poly3-hydroxybutyrate), 25:75 P(3HO)/P(3HB) blend (PHA blend). Various concentrations of each BG (0.5 wt%, 1.0 wt% and 2.5 wt%) were used to determine the effect of BG on neuronal growth and differentiation, in single culture using NG108-15 neuronal cells and in a co-culture along with RN22 Schwann cells. NG108-15 cells exhibited good growth and differentiation on all the PHA blend composites showing that both BGs have good biocompatibility at 0.5 wt%, 1.0 wt% and 2.5 wt% within the PHA blend. The Young's modulus values displayed by all the PHA blend/BG composites ranged from 385.6 MPa to 1792.6 MPa, which are able to provide the required support and protective effect for the regeneration of peripheral nerves. More specifically, the tensile strength obtained in the PHA blend/BG1 (1.0 wt%) (10.0 ± 0.6 MPa) was found to be similar to that of the rabbit peroneal nerve. This composite also exhibited the best biological performance in supporting growth and neuronal differentiation among all the substrates. The neurite extension on this composite was found to be remarkable with the neurites forming a complex connection network.
Collapse
Affiliation(s)
- Lorena R Lizarraga-Valderrama
- Applied Biotechnology Research Group, School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London, United Kingdom. School of Life Sciences, Medical School, University of Nottingham, Nottigham, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Shao X, Sørensen MH, Xia X, Fang C, Hui TH, Chang RCC, Chu Z, Lin Y. Beading of injured axons driven by tension- and adhesion-regulated membrane shape instability. J R Soc Interface 2020; 17:20200331. [PMCID: PMC7423423 DOI: 10.1098/rsif.2020.0331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/13/2020] [Indexed: 08/14/2023] Open
Abstract
The formation of multiple beads along an injured axon will lead to blockage of axonal transport and eventually neuron death, and this has been widely recognized as a hallmark of nervous system degeneration. Nevertheless, the underlying mechanisms remain poorly understood. Here, we report a combined experimental and theoretical study to reveal key factors governing axon beading. Specifically, by transecting well-developed axons with a sharp atomic force microscope probe, significant beading of the axons was triggered. We showed that adhesion was not required for beading to occur, although when present strong axon–substrate attachments seemed to set the locations for bead formation. In addition, the beading wavelength, representing the average distance between beads, was found to correlate with the size and cytoskeleton integrity of axon, with a thinner axon or a disrupted actin cytoskeleton both leading to a shorter beading wavelength. A model was also developed to explain these observations which suggest that axon beading originates from the shape instability of the membrane and is driven by the release of work done by axonal tension as well as the reduction of membrane surface energy. The beading wavelength predicted from this theory was in good agreement with our experiments under various conditions. By elucidating the essential physics behind axon beading, the current study could enhance our understanding of how axonal injury and neurodegeneration progress as well as provide insights for the development of possible treatment strategies.
Collapse
Affiliation(s)
- Xueying Shao
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
- HKU-Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, People's Republic of China
| | - Maja Højvang Sørensen
- Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Xingyu Xia
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
- HKU-Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, People's Republic of China
| | - Chao Fang
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
- HKU-Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, People's Republic of China
| | - Tsz Hin Hui
- Department of Electrical and Electronic Engineering, Joint Appointment with School of Biomedical Sciences, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Raymond Chuen Chung Chang
- Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Zhiqin Chu
- Department of Electrical and Electronic Engineering, Joint Appointment with School of Biomedical Sciences, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Yuan Lin
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, People's Republic of China
- HKU-Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, People's Republic of China
| |
Collapse
|
13
|
Smith TP, Sahoo PK, Kar AN, Twiss JL. Intra-axonal mechanisms driving axon regeneration. Brain Res 2020; 1740:146864. [PMID: 32360100 DOI: 10.1016/j.brainres.2020.146864] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/27/2022]
Abstract
Traumatic injury to the peripheral and central nervous systems very often causes axotomy, where an axon loses connections with its target resulting in loss of function. The axon segments distal to the injury site lose connection with the cell body and degenerate. Axotomized neurons in the periphery can spontaneously mount a regenerative response and reconnect to their denervated target tissues, though this is rarely complete in humans. In contrast, spontaneous regeneration rarely occurs after axotomy in the spinal cord and brain. Here, we concentrate on the mechanisms underlying this spontaneous regeneration in the peripheral nervous system, focusing on events initiated from the axon that support regenerative growth. We contrast this with what is known for axonal injury responses in the central nervous system. Considering the neuropathy focus of this special issue, we further draw parallels and distinctions between the injury-response mechanisms that initiate regenerative gene expression programs and those that are known to trigger axon degeneration.
Collapse
Affiliation(s)
- Terika P Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
| |
Collapse
|
14
|
Sabin KZ, Echeverri K. The role of the immune system during regeneration of the central nervous system. ACTA ACUST UNITED AC 2019; 7. [PMID: 32864529 DOI: 10.1016/j.regen.2019.100023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Central nervous system damage in mammals leads to neuronal cell death, axonal degeneration, and formation of a glial scar resulting in functional and behavioral defects. Other vertebrates, like fish and salamanders, have retained the ability to functionally regenerate after central nervous system injury. To date research from many research organisms has led to a more concise understanding of the response of local neural cells to injury. However, it has become clear that non-neural cells of the immune system play an important role in determining the tissue response to injury. In this review we briefly consider the mammalian response to injury compared to organisms with the natural ability to regenerate. We then discuss similarities and differences in how cells of the innate and adaptive immune system respond and contribute to tissue repair in various species.
Collapse
Affiliation(s)
- K Z Sabin
- Eugene Bell Center for Regenerative Biology & Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543 USA
| | - K Echeverri
- Eugene Bell Center for Regenerative Biology & Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02543 USA
| |
Collapse
|
15
|
Fu H, Han G, Li H, Liang X, Hu D, Zhang L, Tang P. Identification of Key Genes and Pathways Involved in the Heterogeneity of Intrinsic Growth Ability Between Neurons After Spinal Cord Injury in Adult Zebrafish. Neurochem Res 2019; 44:2057-2067. [PMID: 31325155 DOI: 10.1007/s11064-019-02841-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 05/05/2019] [Accepted: 07/03/2019] [Indexed: 02/07/2023]
Abstract
In the adult central nervous system (CNS), axon regeneration is a major hurdle for functional recovery after trauma. The intrinsic growth potential of an injured axon varies widely between neurons. The underlying molecular mechanisms of such heterogeneity are largely unclear. In the present study, the adult zebrafish dataset GSE56842 were downloaded. Differentially expressed genes (DEGs) were sorted and deeply analyzed by bioinformatics methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed with the DAVID. A DEGs-associated protein-protein interaction network was constructed from the STRING database and visualized with Cytoscape software. In total, 621 DEGs were identified. GO analysis showed that the biological processes of DEGs focused mainly on the Notch signaling pathway, cell differentiation and positive regulation of neuron differentiation. The molecular functions mainly included calcium-transporting ATPase activity and calcium ion binding and structural constituents of the cytoskeleton. The cellular components included the plasma membrane, spectrin, and cytoplasmic and membrane-bound vesicles. KEGG pathway analysis showed that these DEGs were mainly involved in the metabolic pathway and Notch signaling pathway, and subnetworks revealed that genes within modules were involved in the metabolic pathway, Wnt signaling pathway, and calcium signaling pathway. This study identified DEG candidate genes and pathways involved in the heterogeneity of the intrinsic growth ability between neurons after spinal cord injury in adult zebrafish, which could facilitate our understanding of the molecular mechanisms underlying axon regeneration, and these candidate genes and pathways could be therapeutic targets for the treatment of CNS injury.
Collapse
Affiliation(s)
- Haitao Fu
- School of Medicine, Nankai University, Tianjin, 300110, China.,Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, 100853, China
| | - Gonghai Han
- Kunming Medical University, Kunming, 650500, China
| | - Haojiang Li
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, 030000, China
| | - Xuezhen Liang
- The First Clinical Medical School, Shandong University of Traditional Chinese Medicine, Shandong, 250355, China
| | - Die Hu
- Qingdao Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao, 266071, China
| | - Licheng Zhang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, 100853, China.
| | - Peifu Tang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, 100853, China.
| |
Collapse
|
16
|
Rink S, Bendella H, Akkin SM, Manthou M, Grosheva M, Angelov DN. Experimental Studies on Facial Nerve Regeneration. Anat Rec (Hoboken) 2019; 302:1287-1303. [DOI: 10.1002/ar.24123] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 10/09/2018] [Accepted: 11/02/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Svenja Rink
- Department of Prosthetic Dentistry, School of Dental and Oral MedicineUniversity of Cologne Cologne Germany
| | - Habib Bendella
- Department of NeurosurgeryUniversity of Witten/Herdecke, Cologne Merheim Medical Center (CMMC) Cologne Germany
| | - Salih Murat Akkin
- Department of Anatomy, School of MedicineSANKO University Gaziantep Turkey
| | - Marilena Manthou
- Department of Histology and EmbryologyAristotle University Thessaloniki Thessaloniki Greece
| | - Maria Grosheva
- Department of Oto‐Rhino‐LaryngologyUniversity of Cologne Cologne Germany
| | | |
Collapse
|
17
|
Jung SH, Jeon HY, Lee SH, Han ET, Park WS, Hong SH, Kim YM, Ha KS. On-chip dual enzyme activity assay to investigate regulation of the transamidase and kinase activities of transglutaminase 2. Anal Chim Acta 2018; 1027:92-100. [DOI: 10.1016/j.aca.2018.04.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 03/23/2018] [Accepted: 04/05/2018] [Indexed: 10/17/2022]
|
18
|
Girouard MP, Bueno M, Julian V, Drake S, Byrne AB, Fournier AE. The Molecular Interplay between Axon Degeneration and Regeneration. Dev Neurobiol 2018; 78:978-990. [PMID: 30022605 DOI: 10.1002/dneu.22627] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/29/2018] [Accepted: 06/04/2018] [Indexed: 12/30/2022]
Abstract
Neurons face a series of morphological and molecular changes following trauma and in the progression of neurodegenerative disease. In neurons capable of mounting a spontaneous regenerative response, including invertebrate neurons and mammalian neurons of the peripheral nervous system (PNS), axons regenerate from the proximal side of the injury and degenerate on the distal side. Studies of Wallerian degeneration slow (WldS /Ola) mice have revealed that a level of coordination between the processes of axon regeneration and degeneration occurs during successful repair. Here, we explore how shared cellular and molecular pathways that regulate both axon regeneration and degeneration coordinate the two distinct outcomes in the proximal and distal axon segments. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 00: 000-000, 2018.
Collapse
Affiliation(s)
- Marie-Pier Girouard
- Department of Neurology & Neurosurgery, Montréal Neurological Institute, Montréal, Quebec H3A 2B4, Canada
| | - Mardja Bueno
- Department of Neurology & Neurosurgery, Montréal Neurological Institute, Montréal, Quebec H3A 2B4, Canada
| | - Victoria Julian
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Sienna Drake
- Department of Neurology & Neurosurgery, Montréal Neurological Institute, Montréal, Quebec H3A 2B4, Canada
| | - Alexandra B Byrne
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Alyson E Fournier
- Department of Neurology & Neurosurgery, Montréal Neurological Institute, Montréal, Quebec H3A 2B4, Canada
| |
Collapse
|
19
|
Chen L. Microtubules and axon regeneration in C. elegans. Mol Cell Neurosci 2018; 91:160-166. [PMID: 29551667 DOI: 10.1016/j.mcn.2018.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 11/28/2022] Open
Abstract
Axon regeneration is a fundamental and conserved process that allows the nervous system to repair circuits after trauma. Due to its conserved genome, transparent body, and relatively simple neuroanatomy, C. elegans has become a powerful model organism for studying the cellular and molecular mechanisms underlying axon regeneration. Various studies from different model organisms have found microtubule dynamics to be pivotal to axon regrowth. In this review, we will discuss the latest findings on how microtubule dynamics are regulated during axon regeneration in C. elegans. Understanding the mechanisms of axon regeneration will aid in the development of more effective therapeutic strategies for treatments of diseases involving disconnection of axons, such as spinal cord injury and stroke.
Collapse
Affiliation(s)
- Lizhen Chen
- Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, Department of Molecular Medicine, University of Texas Health Science Center San Antonio, San Antonio, TX, USA.
| |
Collapse
|
20
|
Ivakhnitskaia E, Lin RW, Hamada K, Chang C. Timing of neuronal plasticity in development and aging. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2017; 7. [PMID: 29139210 DOI: 10.1002/wdev.305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 08/21/2017] [Accepted: 09/11/2017] [Indexed: 01/21/2023]
Abstract
Molecular oscillators are well known for their roles in temporal control of some biological processes like cell proliferation, but molecular mechanisms that provide temporal control of differentiation and postdifferentiation events in cells are less understood. In the nervous system, establishment of neuronal connectivity during development and decline in neuronal plasticity during aging are regulated with temporal precision, but the timing mechanisms are largely unknown. Caenorhabditis elegans has been a preferred model for aging research and recently emerges as a new model for the study of developmental and postdevelopmental plasticity in neurons. In this review we discuss the emerging mechanisms in timing of developmental lineage progression, axon growth and pathfinding, synapse formation, and reorganization, and neuronal plasticity in development and aging. We also provide a current view on the conserved core axon regeneration molecules with the intention to point out potential regulatory points of temporal controls. We highlight recent progress in understanding timing mechanisms that regulate decline in regenerative capacity, including progressive changes of intrinsic timers and co-opting the aging pathway molecules. WIREs Dev Biol 2018, 7:e305. doi: 10.1002/wdev.305 This article is categorized under: Invertebrate Organogenesis > Worms Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Nervous System Development > Worms Gene Expression and Transcriptional Hierarchies > Regulatory RNA.
Collapse
Affiliation(s)
- Evguenia Ivakhnitskaia
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.,Medical Scientist Training Program, University of Illinois at Chicago, Chicago, IL, USA.,Graduate Program in Neuroscience, University of Illinois at Chicago, Chicago, IL, USA
| | - Ryan Weihsiang Lin
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Kana Hamada
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Chieh Chang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.,Graduate Program in Neuroscience, University of Illinois at Chicago, Chicago, IL, USA
| |
Collapse
|
21
|
Bendella H, Rink S, Grosheva M, Sarikcioglu L, Gordon T, Angelov DN. Putative roles of soluble trophic factors in facial nerve regeneration, target reinnervation, and recovery of vibrissal whisking. Exp Neurol 2017; 300:100-110. [PMID: 29104116 DOI: 10.1016/j.expneurol.2017.10.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/25/2017] [Accepted: 10/30/2017] [Indexed: 12/15/2022]
Abstract
It is well-known that, after nerve transection and surgical repair, misdirected regrowth of regenerating motor axons may occur in three ways. The first way is that the axons enter into endoneurial tubes that they did not previously occupy, regenerate through incorrect fascicles and reinnervate muscles that they did not formerly supply. Consequently the activation of these muscles results in inappropriate movements. The second way is that, in contrast with the precise target-directed pathfinding by elongating motor nerves during embryonic development, several axons rather than a single axon grow out from each transected nerve fiber. The third way of misdirection occurs by the intramuscular terminal branching (sprouting) of each regenerating axon to culminate in some polyinnervation of neuromuscular junctions, i.e. reinnervation of junctions by more than a single axon. Presently, "fascicular" or "topographic specificity" cannot be achieved and hence target-directed nerve regeneration is, as yet, unattainable. Nonetheless, motor and sensory reinnervation of appropriate endoneurial tubes does occur and can be promoted by brief nerve electrical stimulation. This review considers the expression of neurotrophic factors in the neuromuscular system and how this expression can promote functional recovery, with emphasis on the whisking of vibrissae on the rat face in relationship to the expression of the factors. Evidence is reviewed for a role of neurotrophic factors as short-range diffusible sprouting stimuli in promoting complete functional recovery of vibrissal whisking in blind Sprague Dawley (SD)/RCS rats but not in SD rats with normal vision, after facial nerve transection and surgical repair. Briefly, a complicated time course of growth factor expression in the nerves and denervated muscles include (1) an early increase in FGF2 and IGF2, (2) reduced NGF between 2 and 14days after nerve transection and surgical repair, (3) a late rise in BDNF and (4) reduced IGF1 protein in the denervated muscles at 28days. These findings suggest that recovery of motor function after peripheral nerve injury is due, at least in part, to a complex regulation of nerve injury-associated neurotrophic factors and cytokines at the neuromuscular junctions of denervated muscles. In particular, the increase of FGF2 and concomittant decrease of NGF during the first week after facial nerve-nerve anastomosis in SD/RCS blind rats may prevent intramuscular axon sprouting and, in turn, reduce poly-innervation of the neuromuscular junction.
Collapse
Affiliation(s)
- Habib Bendella
- Department of Neurosurgery, University of Witten/Herdecke, Cologne Merheim Medical Center (CMMC), Cologne, Germany
| | - Svenja Rink
- Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Germany
| | - Maria Grosheva
- Department of Oto-Rhino-Laryngology, University of Cologne, Germany
| | | | - Tessa Gordon
- Department of Surgery, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | | |
Collapse
|
22
|
Ordaz JD, Wu W, Xu XM. Optogenetics and its application in neural degeneration and regeneration. Neural Regen Res 2017; 12:1197-1209. [PMID: 28966628 PMCID: PMC5607808 DOI: 10.4103/1673-5374.213532] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2017] [Indexed: 12/30/2022] Open
Abstract
Neural degeneration and regeneration are important topics in neurological diseases. There are limited options for therapeutic interventions in neurological diseases that provide simultaneous spatial and temporal control of neurons. This drawback increases side effects due to non-specific targeting. Optogenetics is a technology that allows precise spatial and temporal control of cells. Therefore, this technique has high potential as a therapeutic strategy for neurological diseases. Even though the application of optogenetics in understanding brain functional organization and complex behaviour states have been elaborated, reviews of its therapeutic potential especially in neurodegeneration and regeneration are still limited. This short review presents representative work in optogenetics in disease models such as spinal cord injury, multiple sclerosis, epilepsy, Alzheimer's disease and Parkinson's disease. It is aimed to provide a broader perspective on optogenetic therapeutic potential in neurodegeneration and neural regeneration.
Collapse
Affiliation(s)
- Josue D. Ordaz
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Goodman Campbell Brain and Spine, Indianapolis, Indiana, USA
| | - Wei Wu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Goodman Campbell Brain and Spine, Indianapolis, Indiana, USA
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
- Goodman Campbell Brain and Spine, Indianapolis, Indiana, USA
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| |
Collapse
|
23
|
Chaudhury AR, Insolera R, Hwang RD, Fridell YW, Collins C, Chronis N. On chip cryo-anesthesia of Drosophila larvae for high resolution in vivo imaging applications. LAB ON A CHIP 2017; 17:2303-2322. [PMID: 28613308 PMCID: PMC5559736 DOI: 10.1039/c7lc00345e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We present a microfluidic chip for immobilizing Drosophila melanogaster larvae for high resolution in vivo imaging. The chip creates a low-temperature micro-environment that anaesthetizes and immobilizes the larva in under 3 minutes. We characterized the temperature distribution within the chip and analyzed the resulting larval body movement using high resolution fluorescence imaging. Our results indicate that the proposed method minimizes submicron movements of internal organs and tissue without affecting the larva physiology. It can be used to continuously immobilize larvae for short periods of time (minutes) or for longer periods (several hours) if used intermittently. The same chip can be used to accommodate and immobilize arvae across all developmental stages (1st instar to late 3rd instar), and loading larvae onto the chip does not require any specialized skills. To demonstrate the usability of the chip, we observed mitochondrial trafficking in neurons from the cell bodies to the axon terminals along with mitochondrial fusion and neuro-synaptic growth through time in intact larvae. Besides studying sub-cellular processes and cellular development, we envision the use of on chip cryo-anesthesia in a wide variety of biological in vivo imaging applications, including observing organ development of the salivary glands, fat bodies and body-wall muscles.
Collapse
Affiliation(s)
- Amrita Ray Chaudhury
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
| | | | | | | | | | | |
Collapse
|
24
|
Hill CE. A view from the ending: Axonal dieback and regeneration following SCI. Neurosci Lett 2017; 652:11-24. [DOI: 10.1016/j.neulet.2016.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 10/20/2016] [Accepted: 11/01/2016] [Indexed: 12/22/2022]
|
25
|
Epigenetics and Signaling Pathways in Glaucoma. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5712341. [PMID: 28210622 PMCID: PMC5292191 DOI: 10.1155/2017/5712341] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/28/2016] [Accepted: 12/13/2016] [Indexed: 12/22/2022]
Abstract
Glaucoma is the most common cause of irreversible blindness worldwide. This neurodegenerative disease becomes more prevalent with aging, but predisposing genetic and environmental factors also contribute to increased risk. Emerging evidence now suggests that epigenetics may also be involved, which provides potential new therapeutic targets. These three factors work through several pathways, including TGF-β, MAP kinase, Rho kinase, BDNF, JNK, PI-3/Akt, PTEN, Bcl-2, Caspase, and Calcium-Calpain signaling. Together, these pathways result in the upregulation of proapoptotic gene expression, the downregulation of neuroprotective and prosurvival factors, and the generation of fibrosis at the trabecular meshwork, which may block aqueous humor drainage. Novel therapeutic agents targeting these pathway members have shown preliminary success in animal models and even human trials, demonstrating that they may eventually be used to preserve retinal neurons and vision.
Collapse
|
26
|
Increase in Growth Cone Size Correlates with Decrease in Neurite Growth Rate. Neural Plast 2016; 2016:3497901. [PMID: 27274874 PMCID: PMC4870373 DOI: 10.1155/2016/3497901] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/03/2016] [Indexed: 11/18/2022] Open
Abstract
Several important discoveries in growth cone cell biology were made possible by the use of growth cones derived from cultured Aplysia bag cell neurons, including the characterization of the organization and dynamics of the cytoskeleton. The majority of these Aplysia studies focused on large growth cones induced by poly-L-lysine substrates at early stages in cell culture. Under these conditions, the growth cones are in a steady state with very little net advancement. Here, we offer a comprehensive cellular analysis of the motile behavior of Aplysia growth cones in culture beyond this pausing state. We found that average growth cone size decreased with cell culture time whereas average growth rate increased. This inverse correlation of growth rate and growth cone size was due to the occurrence of large growth cones with a peripheral domain larger than 100 μm(2). The large pausing growth cones had central domains that were less consistently aligned with the direction of growth and could be converted into smaller, faster-growing growth cones by addition of a three-dimensional collagen gel. We conclude that the significant lateral expansion of lamellipodia and filopodia as observed during these culture conditions has a negative effect on neurite growth.
Collapse
|
27
|
He Z, Jin Y. Intrinsic Control of Axon Regeneration. Neuron 2016; 90:437-51. [DOI: 10.1016/j.neuron.2016.04.022] [Citation(s) in RCA: 337] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/10/2016] [Accepted: 04/13/2016] [Indexed: 01/12/2023]
|
28
|
van Niekerk EA, Tuszynski MH, Lu P, Dulin JN. Molecular and Cellular Mechanisms of Axonal Regeneration After Spinal Cord Injury. Mol Cell Proteomics 2015; 15:394-408. [PMID: 26695766 DOI: 10.1074/mcp.r115.053751] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Indexed: 12/28/2022] Open
Abstract
Following axotomy, a complex temporal and spatial coordination of molecular events enables regeneration of the peripheral nerve. In contrast, multiple intrinsic and extrinsic factors contribute to the general failure of axonal regeneration in the central nervous system. In this review, we examine the current understanding of differences in protein expression and post-translational modifications, activation of signaling networks, and environmental cues that may underlie the divergent regenerative capacity of central and peripheral axons. We also highlight key experimental strategies to enhance axonal regeneration via modulation of intraneuronal signaling networks and the extracellular milieu. Finally, we explore potential applications of proteomics to fill gaps in the current understanding of molecular mechanisms underlying regeneration, and to provide insight into the development of more effective approaches to promote axonal regeneration following injury to the nervous system.
Collapse
Affiliation(s)
- Erna A van Niekerk
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093;
| | - Mark H Tuszynski
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093; §Veterans Administration Medical Center, San Diego, CA 92161
| | - Paul Lu
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093; §Veterans Administration Medical Center, San Diego, CA 92161
| | - Jennifer N Dulin
- From the ‡Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093
| |
Collapse
|
29
|
Abstract
Peripheral axonal regeneration requires surface-expanding membrane addition. The continuous incorporation of new membranes into the axolemma allows the pushing force of elongating microtubules to drive axonal growth cones forwards. Hence, a constant supply of membranes and cytoskeletal building blocks is required, often for many weeks. In human peripheral nerves, axonal tips may be more than 1 m away from the neuronal cell body. Therefore, in the initial phase of regeneration, membranes are derived from pre-existing vesicles or synthesised locally. Only later stages of axonal regeneration are supported by membranes and proteins synthesised in neuronal cell bodies, considering that the fastest anterograde transport mechanisms deliver cargo at 20 cm/day. Whereas endocytosis and exocytosis of membrane vesicles are balanced in intact axons, membrane incorporation exceeds membrane retrieval during regeneration to compensate for the loss of membranes distal to the lesion site. Physiological membrane turnover rates will not be established before the completion of target reinnervation. In this review, the current knowledge on membrane traffic in axonal outgrowth is summarised, with a focus on endosomal vesicles as the providers of membranes and carriers of growth factor receptors required for initiating signalling pathways to promote the elongation and branching of regenerating axons in lesioned peripheral nerves.
Collapse
Affiliation(s)
- Barbara Hausott
- Division of Neuroanatomy, Department of Anatomy, Histology and Embryology, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Lars Klimaschewski
- Division of Neuroanatomy, Department of Anatomy, Histology and Embryology, Medical University Innsbruck, 6020, Innsbruck, Austria
| |
Collapse
|
30
|
Lu W, Lakonishok M, Gelfand VI. Kinesin-1-powered microtubule sliding initiates axonal regeneration in Drosophila cultured neurons. Mol Biol Cell 2015; 26:1296-307. [PMID: 25657321 PMCID: PMC4454177 DOI: 10.1091/mbc.e14-10-1423] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Microtubule sliding drives initial axon regeneration in Drosophila neurons. Axotomy leads to fast calcium influx and subsequent microtubule reorganization. Kinesin-1 heavy chain drives the sliding of antiparallel microtubules to power axonal regrowth, and the JNK pathway promotes axonal regeneration by enhancing microtubule sliding. Understanding the mechanism underlying axon regeneration is of great practical importance for developing therapeutic treatment for traumatic brain and spinal cord injuries. Dramatic cytoskeleton reorganization occurs at the injury site, and microtubules have been implicated in the regeneration process. Previously we demonstrated that microtubule sliding by conventional kinesin (kinesin-1) is required for initiation of neurite outgrowth in Drosophila embryonic neurons and that sliding is developmentally down-regulated when neurite outgrowth is completed. Here we report that mechanical axotomy of Drosophila neurons in culture triggers axonal regeneration and regrowth. Regenerating neurons contain actively sliding microtubules; this sliding, like sliding during initial neurite outgrowth, is driven by kinesin-1 and is required for axonal regeneration. The injury induces a fast spike of calcium, depolymerization of microtubules near the injury site, and subsequent formation of local new microtubule arrays with mixed polarity. These events are required for reactivation of microtubule sliding at the initial stages of regeneration. Furthermore, the c-Jun N-terminal kinase pathway promotes regeneration by enhancing microtubule sliding in injured mature neurons.
Collapse
Affiliation(s)
- Wen Lu
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Margot Lakonishok
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| |
Collapse
|
31
|
Axon regeneration in C. elegans. Curr Opin Neurobiol 2014; 27:199-207. [PMID: 24794753 DOI: 10.1016/j.conb.2014.04.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 04/01/2014] [Accepted: 04/01/2014] [Indexed: 11/22/2022]
Abstract
Single axon transection by laser surgery has made Caenorhabditis elegans a new model for axon regeneration. Multiple conserved molecular signaling modules have been discovered through powerful genetic screening. In vivo imaging with single cell and axon resolution has revealed unprecedented cellular dynamics in regenerating axons. Information from C. elegans has greatly expanded our knowledge of the molecular and cellular mechanisms of axon regeneration.
Collapse
|
32
|
Abstract
The ability of injured axons to regenerate declines with age, yet the mechanisms that regulate axon regeneration in response to age are not known. Here we show that axon regeneration in aging C. elegans motor neurons is inhibited by the conserved insulin/IGF1 receptor DAF-2. DAF-2's function in regeneration is mediated by intrinsic neuronal activity of the forkhead transcription factor DAF-16/FOXO. DAF-16 regulates regeneration independently of lifespan, indicating that neuronal aging is an intrinsic, neuron-specific, and genetically regulated process. In addition, we found that DAF-18/PTEN inhibits regeneration independently of age and FOXO signaling via the TOR pathway. Finally, DLK-1, a conserved regulator of regeneration, is downregulated by insulin/IGF1 signaling, bound by DAF-16 in neurons, and required for both DAF-16- and DAF-18-mediated regeneration. Together, our data establish that insulin signaling specifically inhibits regeneration in aging adult neurons and that this mechanism is independent of PTEN and TOR.
Collapse
|
33
|
Prokosch V, Chiwitt C, Rose K, Thanos S. Deciphering proteins and their functions in the regenerating retina. Expert Rev Proteomics 2014; 7:775-95. [DOI: 10.1586/epr.10.47] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
34
|
Butt GF, Habib A, Mahgoub K, Sofela A, Tilley M, Guo L, Cordeiro MF. Optic nerve regeneration. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.12.66] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
35
|
Abstract
Axon regeneration after damage is widespread in the animal kingdom, and the nematode Caenorhabditis elegans has recently emerged as a tractable model in which to study the genetics and cell biology of axon regrowth in vivo. A key early step in axon regrowth is the conversion of part of a mature axon shaft into a growth cone-like structure, involving coordinated alterations in the microtubule, actin, and neurofilament systems. Recent attention has focused on microtubule dynamics as a determinant of axon-regrowth ability in several organisms. Live imaging studies have begun to reveal how the microtubule cytoskeleton is remodeled after axon injury, as well as the regulatory pathways involved. The dual leucine zipper kinase family of mixed-lineage kinases has emerged as a critical sensor of axon damage and plays a key role in regulating microtubule dynamics in the damaged axon.
Collapse
Affiliation(s)
- Andrew D Chisholm
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, La Jolla, California 92093;
| |
Collapse
|
36
|
Klimaschewski L, Hausott B, Angelov DN. The pros and cons of growth factors and cytokines in peripheral axon regeneration. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2013; 108:137-71. [PMID: 24083434 DOI: 10.1016/b978-0-12-410499-0.00006-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Injury to a peripheral nerve induces a complex cellular and molecular response required for successful axon regeneration. Proliferating Schwann cells organize into chains of cells bridging the lesion site, which is invaded by macrophages. Approximately half of the injured neuron population sends out axons that enter the glial guidance channels in response to secreted neurotrophic factors and neuropoietic cytokines. These lesion-associated polypeptides create an environment that is highly supportive for axon regrowth, particularly after acute injury, and ensure that the vast majority of regenerating axons are directed toward the distal nerve stump. Unfortunately, most neurotrophic factors and neuropoietic cytokines are also strong stimulators of axonal sprouting. Although some of the axonal branches will withdraw at later stages, the sprouting effect contributes to the misdirection of reinnervation that results in the lack of functional recovery observed in many patients with peripheral nerve injuries. Here, we critically review the role of neuronal growth factors and cytokines during axon regeneration in the peripheral nervous system. Their differential effects on axon elongation and sprouting were elucidated in various studies on intraneuronal signaling mechanisms following nerve lesion. The present data define a goal for future therapeutic strategies, namely, to selectively stimulate a Ras/Raf/ERK-mediated axon elongation program over an intrinsic PI3K-dependent axonal sprouting program in lesioned motor and sensory neurons. Instead of modulating growth factor or cytokine levels at the lesion site, targeting specific intraneuronal molecules, such as the negative feedback inhibitors of ERK signaling, has been shown to promote long-distance regeneration while avoiding sprouting of regenerating axons until they have reached their target areas.
Collapse
Affiliation(s)
- Lars Klimaschewski
- Division of Neuroanatomy, Department of Anatomy and Histology, Innsbruck Medical University, Innsbruck, Austria
| | | | | |
Collapse
|
37
|
Camara-Lemarroy CR, Gonzalez-Moreno EI, Guzman-de la Garza FJ, Fernandez-Garza NE. Arachidonic acid derivatives and their role in peripheral nerve degeneration and regeneration. ScientificWorldJournal 2012; 2012:168953. [PMID: 22997489 PMCID: PMC3446639 DOI: 10.1100/2012/168953] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 08/10/2012] [Indexed: 01/23/2023] Open
Abstract
After peripheral nerve injury, a process of axonal degradation, debris clearance, and subsequent regeneration is initiated by complex local signaling, called Wallerian degeneration (WD). This process is in part mediated by neuroglia as well as infiltrating inflammatory cells and regulated by inflammatory mediators such as cytokines, chemokines, and the activation of transcription factors also related to the inflammatory response. Part of this neuroimmune signaling is mediated by the innate immune system, including arachidonic acid (AA) derivatives such as prostaglandins and leukotrienes. The enzymes responsible for their production, cyclooxygenases and lipooxygenases, also participate in nerve degeneration and regeneration. The interactions between signals for nerve regeneration and neuroinflammation go all the way down to the molecular level. In this paper, we discuss the role that AA derivatives might play during WD and nerve regeneration, and the therapeutic possibilities that arise.
Collapse
Affiliation(s)
- Carlos Rodrigo Camara-Lemarroy
- Departamento de Medicina Interna, Hospital Universitario "José Eleuterio González", Universidad Autónoma de Nuevo León, School of Medicine, Colonia Mitras Centro, 64460 Monterrey, Nuevo León, Mexico.
| | | | | | | |
Collapse
|
38
|
Vuppalanchi D, Merianda TT, Donnelly C, Pacheco A, Williams G, Yoo S, Ratan RR, Willis DE, Twiss JL. Lysophosphatidic acid differentially regulates axonal mRNA translation through 5'UTR elements. Mol Cell Neurosci 2012; 50:136-46. [PMID: 22522146 DOI: 10.1016/j.mcn.2012.04.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Revised: 03/16/2012] [Accepted: 04/02/2012] [Indexed: 12/15/2022] Open
Abstract
Sensory neurons transport a complex population of mRNAs into their axons, including many encoding ER chaperone proteins. Transport of the mRNA encoding the ER chaperone protein calreticulin is regulated through 3'UTR elements. In other cellular systems, translation of chaperone protein mRNAs can be regulated by ER stress. Here, we have asked if the translation of axonal calreticulin mRNA is regulated in a different manner than its transport into axons. Treatment with lysophosphatidic acid, which is known to trigger axon retraction and stimulate ER Ca(2+) release, caused a translation-dependent increase in axonal calreticulin protein levels. RNA sequences in the 5'UTR of calreticulin confer this translational control through a mechanism that requires an inactivating phosphorylation of eIF2α. In contrast to calreticulin, these signaling events do not activate axonal translation through β-actin's 5'UTR. Together, these data indicate that stimulation of ER stress can regulate specificity of localized mRNA translation through 5'UTR elements.
Collapse
|
39
|
Assembly of a new growth cone after axotomy: the precursor to axon regeneration. Nat Rev Neurosci 2012; 13:183-93. [PMID: 22334213 DOI: 10.1038/nrn3176] [Citation(s) in RCA: 327] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The assembly of a new growth cone is a prerequisite for axon regeneration after injury. Creation of a new growth cone involves multiple processes, including calcium signalling, restructuring of the cytoskeleton, transport of materials, local translation of messenger RNAs and the insertion of new membrane and cell surface molecules. In axons that have an intrinsic ability to regenerate, these processes are executed in a timely fashion. However, in axons that lack regenerative capacity, such as those of the mammalian CNS, several of the steps that are required for regeneration fail, and these axons do not begin the growth process. Identification of the points of failure can suggest targets for promoting regeneration.
Collapse
|
40
|
Ghannad-Rezaie M, Wang X, Mishra B, Collins C, Chronis N. Microfluidic chips for in vivo imaging of cellular responses to neural injury in Drosophila larvae. PLoS One 2012; 7:e29869. [PMID: 22291895 PMCID: PMC3264548 DOI: 10.1371/journal.pone.0029869] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 12/05/2011] [Indexed: 12/17/2022] Open
Abstract
With powerful genetics and a translucent cuticle, the Drosophila larva is an ideal model system for live imaging studies of neuronal cell biology and function. Here, we present an easy-to-use approach for high resolution live imaging in Drosophila using microfluidic chips. Two different designs allow for non-invasive and chemical-free immobilization of 3rd instar larvae over short (up to 1 hour) and long (up to 10 hours) time periods. We utilized these ‘larva chips’ to characterize several sub-cellular responses to axotomy which occur over a range of time scales in intact, unanaesthetized animals. These include waves of calcium which are induced within seconds of axotomy, and the intracellular transport of vesicles whose rate and flux within axons changes dramatically within 3 hours of axotomy. Axonal transport halts throughout the entire distal stump, but increases in the proximal stump. These responses precede the degeneration of the distal stump and regenerative sprouting of the proximal stump, which is initiated after a 7 hour period of dormancy and is associated with a dramatic increase in F-actin dynamics. In addition to allowing for the study of axonal regeneration in vivo, the larva chips can be utilized for a wide variety of in vivo imaging applications in Drosophila.
Collapse
Affiliation(s)
- Mostafa Ghannad-Rezaie
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Xing Wang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Bibhudatta Mishra
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Catherine Collins
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (NC); (CC)
| | - Nikos Chronis
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (NC); (CC)
| |
Collapse
|
41
|
Abstract
After central nervous system (CNS) injury axons fail to regenerate often leading to persistent neurologic deficit although injured peripheral nervous system (PNS) axons mount a robust regenerative response that may lead to functional recovery. Some of the failures of CNS regeneration arise from the many glial-based inhibitory molecules found in the injured CNS, whereas the intrinsic regenerative potential of some CNS neurons is actively curtailed during CNS maturation and limited after injury. In this review, the molecular basis for extrinsic and intrinsic modulation of axon regeneration within the nervous system is evaluated. A more complete understanding of the factors limiting axonal regeneration will provide a rational basis, which is used to develop improved treatments for nervous system injury.
Collapse
Affiliation(s)
- Toby A Ferguson
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | | |
Collapse
|
42
|
Bloom OE, Morgan JR. Membrane trafficking events underlying axon repair, growth, and regeneration. Mol Cell Neurosci 2011; 48:339-48. [PMID: 21539917 DOI: 10.1016/j.mcn.2011.04.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 04/11/2011] [Accepted: 04/14/2011] [Indexed: 12/31/2022] Open
Abstract
Two central challenges for the field of neurobiology are to understand how axons grow and make proper synaptic connections under normal conditions and how they repair their membranes and mount regenerative responses after injury. At the most reductionist level, the first step toward addressing these challenges is to delineate the cellular and molecular processes by which an axon extends from its cell body. Underlying axon extension are questions of appropriate timing and mechanisms that establish or maintain the axon's polarity, initiate growth cone formation, and promote axon outgrowth and synapse formation. After injury, the problem is even more complicated because the neuron must also repair its damaged membrane, redistribute or manufacture what it needs in order to survive, and grow and form new synapses within a more mature, complex environment. While other reviews have focused extensively on the signaling events and cytoskeletal rearrangements that support axon outgrowth and regeneration, we focus this review instead on the underlying membrane trafficking events underlying these processes. Though the mechanisms are still under active investigation, the key roles played by membrane trafficking events during axon repair, growth, and regeneration have been elucidated through elegant comparative studies in both invertebrate and vertebrate organisms. Taken together, a model emerges indicating that the critical requirements for ensuring proper membrane sealing and axon extension include iterative bouts of SNARE mediated exocytosis, endocytosis, and functional links between vesicles and the actin cytoskeleton, similar to the mechanisms utilized during synaptic transmission. This article is part of a Special Issue entitled 'Neuronal Function'.
Collapse
Affiliation(s)
- Ona E Bloom
- The Center for Autoimmune and Musculoskeletal Disease, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA
| | | |
Collapse
|
43
|
Skouras E, Ozsoy U, Sarikcioglu L, Angelov DN. Intrinsic and therapeutic factors determining the recovery of motor function after peripheral nerve transection. Ann Anat 2011; 193:286-303. [PMID: 21458252 DOI: 10.1016/j.aanat.2011.02.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 02/03/2011] [Accepted: 02/04/2011] [Indexed: 01/01/2023]
Abstract
Insufficient recovery after peripheral nerve injury has been attributed to (i) poor pathfinding of regrowing axons, (ii) excessive collateral axonal branching at the lesion site and (iii) polyneuronal innervation of the neuromuscular junctions (NMJ). The facial nerve transection model has been used initially to measure restoration of function after varying therapies and to examine the mechanisms underlying their effects. Since it is very difficult to control the navigation of several thousand axons, efforts concentrated on collateral branching and NMJ-polyinnervation. Treatment with antibodies against trophic factors to combat branching improved the precision of reinnervation, but had no positive effects on functional recovery. This suggested that polyneuronal reinnervation--rather than collateral branching--may be the critical limiting factor. The former could be reduced by pharmacological agents known to perturb microtubule assembly and was followed by recovery of function. Because muscle polyinnervation is activity-dependent and can be manipulated, attempts to design a clinically feasible therapy were performed by electrical stimulation or by soft tissue massage. Electrical stimulation applied to the transected facial nerve or to paralysed facial muscles did not improve vibrissal motor performance and failed to diminish polyinnervation. In contrast, gentle stroking of the paralysed muscles (vibrissal, orbicularis oculi, tongue musculature) resulted in full recovery of function. This manual stimulation was also effective after hypoglossal-facial nerve suture and after interpositional nerve grafting, but not after surgical reconstruction of the median nerve. All these findings raise hopes that clinically feasible and effective therapies could be soon designed and tested.
Collapse
Affiliation(s)
- Emmanouil Skouras
- Department of Orthopedics and Traumatology, University of Cologne, Joseph-Stelzmann-Strasse 9, Cologne, Germany
| | | | | | | |
Collapse
|
44
|
Torkkeli PH, Panek I, Meisner S. Ca²(+) /calmodulin-dependent protein kinase II mediates the octopamine-induced increase in sensitivity in spider VS-3 mechanosensory neurons. Eur J Neurosci 2011; 33:1186-96. [PMID: 21366726 DOI: 10.1111/j.1460-9568.2011.07624.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
G-protein-coupled octopamine (OA) receptors mediate their effects by Ca²(+) signaling or adjusting intracellular cAMP levels. Depending on OA concentration and cell type, activation of OA receptors in excitable cells triggers excitatory or inhibitory effects, but the mechanisms by which Ca²(+) or cAMP mediates these effects are not well understood. We investigated signaling mechanisms that are potentially activated by OA, and OA effects on excitability and frequency sensitivity in mechanosensory neurons innervating the VS-3 slit sensilla on the patella of the spider Cupiennius salei. These neurons are directly innervated by octopaminergic efferents, and possess OA receptors that were immunoreactive to an antibody against an OA receptor highly expressed in mushroom bodies. OA application enhanced VS-3 neuron sensitivity, especially at high stimulation frequencies. This enhancement lasted for at least 1 h after OA application. Changes in sensitivity were also detected when the Ca²(+) ionophore ionomycin or the cAMP analog 8-Br-cAMP was applied. However, the cAMP pathway was unlikely to mediate the OA effect, as the protein kinase A inhibitor RP-cAMPS did not diminish this effect. In contrast, the OA-induced sensitivity enhancement was significantly reduced by KN-62, an inhibitor of Ca²(+) /calmodulin-dependent protein kinase II (CaMKII), and by the Ca²(+) chelator BAPTA-AM. OA depolarized the neurons by 3.8 mV from resting potential, well below the threshold for opening of voltage-activated Ca²(+) channels. OA also reduced the amplitudes of voltage-activated K(+) currents. We propose that OA receptors in VS-3 neurons activate inositol 1,4,5-trisphosphate, leading to Ca²(+) release from intracellular stores. The Ca²(+) surge switches on CaMKII, which modulates voltage-activated K(+) channels, resulting in persistent enhancement in excitability.
Collapse
Affiliation(s)
- Päivi H Torkkeli
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada.
| | | | | |
Collapse
|
45
|
Yang GY, Liang B, Zhu J, Luo ZG. Calpain activation by Wingless-type murine mammary tumor virus integration site family, member 5A (Wnt5a) promotes axonal growth. J Biol Chem 2011; 286:6566-76. [PMID: 21177867 PMCID: PMC3057826 DOI: 10.1074/jbc.m110.196568] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 11/29/2010] [Indexed: 11/06/2022] Open
Abstract
Axon development involves spatial-temporal cytoskeletal reorganization. However, how the cytoskeleton remodeling is modulated by extracellular cues is unclear. Here, we report a role of Wnt/Ca(2+) signaling in regulating actin and growth cone dynamics. We found that treatment of cultured cortical neurons with Wnt5a, a non-canonical Wnt, either globally or locally, caused an increase in the activity of calpain, a calcium-dependent protease responsible for the cleavage of several actin binding proteins, including spectrin. Treatment with Wnt5a promoted growth cone advance, as well as axonal growth, and these effects were prevented by chelating intracellular calcium, inhibition or down-regulation of calpain, or blockade of spectrin cleavage by competitive peptides. Interestingly, both Wnt5a and activated calpain were found to be mainly distributed in the axon-rich intermediate zone of neocortex. Down-regulating calpain expression interfered with the growth of callosal axons in vivo. Thus, Wnt5a serves as a physiological cue to stimulate localized calpain activity, which in turn promotes growth cone advance and axonal growth.
Collapse
Affiliation(s)
- Guo-Ying Yang
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Bin Liang
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Ji Zhu
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| | - Zhen-Ge Luo
- From the Institute of Neuroscience, State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue Yang Road, Shanghai 200031, China
| |
Collapse
|
46
|
Angelov DN. Factors Limiting Motor Recovery After Facial Nerve Injury. PHYSICAL REHABILITATION OF PARALYSED FACIAL MUSCLES: FUNCTIONAL AND MORPHOLOGICAL CORRELATES 2011. [DOI: 10.1007/978-3-642-18120-7_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
47
|
Shemesh OA, Spira ME. Paclitaxel induces axonal microtubules polar reconfiguration and impaired organelle transport: implications for the pathogenesis of paclitaxel-induced polyneuropathy. Acta Neuropathol 2010; 119:235-48. [PMID: 19727778 DOI: 10.1007/s00401-009-0586-0] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 08/18/2009] [Accepted: 08/18/2009] [Indexed: 12/01/2022]
Abstract
In differentiated axons almost all microtubules (MTs) uniformly point their plus ends towards the axonal tip. The uniform polar pattern provides the structural substrate for efficient organelle transport along axons. It is generally believed that the mass and pattern of MTs polar orientation remain unchanged in differentiated neurons. Here we examined long-term effects of the MTs stabilizing reagent paclitaxel (taxol) over MTs polar orientation and organelle transport in cultured Aplysia neurons. Unexpectedly, we found that rather than stabilizing the MTs, paclitaxel leads to their massive polar reconfiguration, accompanied by impaired organelle transport. Washout of paclitaxel does not lead to recovery of the polar orientation indicating that the new pattern is self-maintained. Taken together the data suggest that MTs in differentiated neurons maintain the potential to be reconfigured. Such reconfiguration may serve physiological functions or lead to degeneration. In addition, our observations offer a novel mechanism that could account for the development of peripheral neuropathy in patients receiving paclitaxel as an antitumor drug.
Collapse
Affiliation(s)
- Or A Shemesh
- Department of Neurobiology, Institute of Life Science, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | | |
Collapse
|
48
|
Extrinsic and intrinsic factors controlling axonal regeneration after spinal cord injury. Expert Rev Mol Med 2009; 11:e37. [PMID: 19968910 DOI: 10.1017/s1462399409001288] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Spinal cord injury is one of the most devastating conditions that affects the central nervous system. It can lead to permanent disability and there are around two million people affected worldwide. After injury, accumulation of myelin debris and formation of an inhibitory glial scar at the site of injury leads to a physical and chemical barrier that blocks axonal growth and regeneration. The mammalian central nervous system thus has a limited intrinsic ability to repair itself after injury. To improve axonal outgrowth and promote functional recovery, it is essential to identify the various intrinsic and extrinsic factors controlling regeneration and navigation of axons within the inhibitory environment of the central nervous system. Recent advances in spinal cord research have opened new avenues for the exploration of potential targets for repairing the cord and improving functional recovery after trauma. Here, we discuss some of the important key molecules that could be harnessed for repairing spinal cord injury.
Collapse
|
49
|
Staal JA, Dickson TC, Gasperini R, Liu Y, Foa L, Vickers JC. Initial calcium release from intracellular stores followed by calcium dysregulation is linked to secondary axotomy following transient axonal stretch injury. J Neurochem 2009; 112:1147-55. [PMID: 19968758 DOI: 10.1111/j.1471-4159.2009.06531.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Acute axonal shear and stretch in the brain induces an evolving form of axonopathy and is a major cause of ongoing motor, cognitive and emotional dysfunction. We have utilized an in vitro model of mild axon bundle stretch injury, in cultured primary cortical neurons, to determine potential early critical cellular alterations leading to secondary axonal degeneration. We determined that transient axonal stretch injury induced an initial acute increase in intracellular calcium, principally derived from intracellular stores, which was followed by a delayed increase in calcium over 48 h post-injury (PI). This progressive and persistent increase in intracellular calcium was also associated with increased frequency of spontaneous calcium fluxes as well as cytoskeletal abnormalities. Additionally, at 48 h post-injury, stretch-injured axon bundles demonstrated filopodia-like sprout formation that preceded secondary axotomy and degeneration. Pharmacological inhibition of the calcium-activated phosphatase, calcineurin, resulted in reduced secondary axotomy (p < 0.05) and increased filopodial sprout length. In summary, these results demonstrate that stretch injury of axons induced an initial substantial release of calcium from intracellular stores with elevated intracellular calcium persisting over 2 days. These long-lasting calcium alterations may provide new insight into the earliest neuronal abnormalities that follow traumatic brain injury as well as the key cellular changes that lead to the development of diffuse axonal injury and secondary degeneration.
Collapse
Affiliation(s)
- Jerome A Staal
- NeuroRepair Group and Wicking Dementia Research and Education Centre, Menzies Research Institute, University of Tasmania, Hobart, Tasmania, Australia.
| | | | | | | | | | | |
Collapse
|
50
|
Kamber D, Erez H, Spira ME. Local calcium-dependent mechanisms determine whether a cut axonal end assembles a retarded endbulb or competent growth cone. Exp Neurol 2009; 219:112-25. [DOI: 10.1016/j.expneurol.2009.05.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 05/03/2009] [Accepted: 05/05/2009] [Indexed: 12/19/2022]
|