1
|
Ji X, Xu Z, Liu D, Chen Y. Effects of exercise training on neurological recovery, TGF-β1, HIF-1α, and Nogo-NgR signaling pathways after spinal cord injury in rats. Clinics (Sao Paulo) 2023; 78:100236. [PMID: 37515927 PMCID: PMC10407281 DOI: 10.1016/j.clinsp.2023.100236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 05/04/2023] [Accepted: 05/31/2023] [Indexed: 07/31/2023] Open
Abstract
OBJECTIVE To evaluate the effects of exercise training on neurological recovery, Growth Transforming Factor-β1 (TGF-β1), Hypoxia Inducible Factor-1α (HIF-1α), and Nogo-NgR signaling pathways after spinal cord injury in rats. METHODS Forty-eight male Sprague-Dawley rats were randomly divided into four groups: normal group, sham-operated group, model group, and training group. The rat spinal cord injury model was established using Allen's method, and the training group received exercise training on the 8th day postoperatively. The Basso, Beattie and Bresnahan (BBB) score, modified Tarlow score, and inclined plane test scores were compared in each group before injury and 1, 7, 14, 21 and 28 days after injury. RESULTS The BBB score and modified Tarlow score of the model group and the training group were 0 at the first day after the injury, and gradually increased on the seventh day onwards (p < 0.05). The BBB score and modified Tarlow score of the training group were higher than those of the model group at the 14th, 21st and 28th day (p < 0.05). The angles of the inclined plate at multiple time points after injury were lower in the model group and the training group than in the normal group and the sham-operated group (p < 0.05); The angles of the inclined plate at the 14th, 21st and 28th day after injury were higher in the training group than in the model group (p < 0.05). CONCLUSION The mechanism of exercise training may be connected to the inhibition of the Nogo-NgR signaling pathway to promote neuronal growth.
Collapse
Affiliation(s)
- Xubin Ji
- Department of Spinal Surgery, Weifang People's Hospital, Weifang, Shandong, PR China
| | - Zhaowan Xu
- Department of Spinal Surgery, Weifang People's Hospital, Weifang, Shandong, PR China
| | - Dayong Liu
- Department of Spinal Surgery, Weifang People's Hospital, Weifang, Shandong, PR China
| | - Yangwang Chen
- Department of Spinal Surgery, Weifang People's Hospital, Weifang, Shandong, PR China.
| |
Collapse
|
2
|
Gupta S, Dutta S, Hui SP. Regenerative Potential of Injured Spinal Cord in the Light of Epigenetic Regulation and Modulation. Cells 2023; 12:1694. [PMID: 37443728 PMCID: PMC10341208 DOI: 10.3390/cells12131694] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/13/2023] [Accepted: 06/17/2023] [Indexed: 07/15/2023] Open
Abstract
A spinal cord injury is a form of physical harm imposed on the spinal cord that causes disability and, in many cases, leads to permanent mammalian paralysis, which causes a disastrous global issue. Because of its non-regenerative aspect, restoring the spinal cord's role remains one of the most daunting tasks. By comparison, the remarkable regenerative ability of some regeneration-competent species, such as some Urodeles (Axolotl), Xenopus, and some teleost fishes, enables maximum functional recovery, even after complete spinal cord transection. During the last two decades of intensive research, significant progress has been made in understanding both regenerative cells' origins and the molecular signaling mechanisms underlying the regeneration and reconstruction of damaged spinal cords in regenerating organisms and mammals, respectively. Epigenetic control has gradually moved into the center stage of this research field, which has been helped by comprehensive work demonstrating that DNA methylation, histone modifications, and microRNAs are important for the regeneration of the spinal cord. In this review, we concentrate primarily on providing a comparison of the epigenetic mechanisms in spinal cord injuries between non-regenerating and regenerating species. In addition, we further discuss the epigenetic mediators that underlie the development of a regeneration-permissive environment following injury in regeneration-competent animals and how such mediators may be implicated in optimizing treatment outcomes for spinal cord injurie in higher-order mammals. Finally, we briefly discuss the role of extracellular vesicles (EVs) in the context of spinal cord injury and their potential as targets for therapeutic intervention.
Collapse
Affiliation(s)
- Samudra Gupta
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India;
| | - Suman Dutta
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK;
| | - Subhra Prakash Hui
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India;
| |
Collapse
|
3
|
Alibardi L. NOGO-A immunolabeling is present in glial cells and some neurons of the recovering lumbar spinal cord in lizards. J Morphol 2020; 281:1260-1270. [PMID: 32770765 DOI: 10.1002/jmor.21245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/07/2020] [Accepted: 07/19/2020] [Indexed: 12/13/2022]
Abstract
The transected lumbar spinal cord of lizards was studied for its ability to recover after paralysis. At 34 days post-lesion about 50% of lizards were capable of walking with a limited coordination, likely due to the regeneration of few connecting axons crossing the transection site of the spinal cord. This region, indicated as "bridge", contains glial cells among which oligodendrocytes and their elongation that are immunolabeled for NOGO-A. A main reactive protein band occurs at 100-110 kDa but a weaker band is also observed around 240 kDa, suggesting fragmentation of the native protein due to extraction or to physiological processing of the original protein. Most of the cytoplasmic immunolabeling observed in oligodendrocytes is associated with vesicles of the endoplasmic reticulum. Also, the nucleus is labeled in some oligodendrocytes that are myelinating sparse axons observed within the bridge at 22-34 days post-transection. This suggests that axonal regeneration is present within the bridge region. Immunolabeling for NOGO-A shows that the protein is also present in numerous reactive neurons, in particular motor-neurons localized in the proximal stump of the transected spinal cord. Ultrastructural immunolocalization suggests that NOGO is synthesized in the ribosomes of these neurons and becomes associated with the cisternae of the endoplasmic reticulum, probably following a secretory pathway addressed toward the axon. The present observations suggest that, like for the regenerating spinal cord of fish and amphibians, also in lizard NOGO-A is present in reactive neurons and appears associated to axonal regeneration and myelination.
Collapse
Affiliation(s)
- Lorenzo Alibardi
- Comparative Histolab Padova and Department of Biology, University of Bologna, Bologna, Italy
| |
Collapse
|
4
|
Enos N, Takenaka H, Scott S, Salfity HVN, Kirk M, Egar MW, Sarria DA, Slayback-Barry D, Belecky-Adams T, Chernoff EAG. Meningeal Foam Cells and Ependymal Cells in Axolotl Spinal Cord Regeneration. Front Immunol 2019; 10:2558. [PMID: 31736973 PMCID: PMC6838144 DOI: 10.3389/fimmu.2019.02558] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/15/2019] [Indexed: 12/01/2022] Open
Abstract
A previously unreported population of foam cells (foamy macrophages) accumulates in the invasive fibrotic meninges during gap regeneration of transected adult Axolotl spinal cord (salamander Ambystoma mexicanum) and may act beneficially. Multinucleated giant cells (MNGCs) also occurred in the fibrotic meninges. Actin-label localization and transmission electron microscopy showed characteristic foam cell and MNGC podosome and ruffled border-containing sealing ring structures involved in substratum attachment, with characteristic intermediate filament accumulations surrounding nuclei. These cells co-localized with regenerating cord ependymal cell (ependymoglial) outgrowth. Phase contrast-bright droplets labeled with Oil Red O, DiI, and DyRect polar lipid live cell label showed accumulated foamy macrophages to be heavily lipid-laden, while reactive ependymoglia contained smaller lipid droplets. Both cell types contained both neutral and polar lipids in lipid droplets. Foamy macrophages and ependymoglia expressed the lipid scavenger receptor CD36 (fatty acid translocase) and the co-transporter toll-like receptor-4 (TLR4). Competitive inhibitor treatment using the modified fatty acid Sulfo-N-succinimidyl Oleate verified the role of the lipid scavenger receptor CD36 in lipid uptake studies in vitro. Fluoromyelin staining showed both cell types took up myelin fragments in situ during the regeneration process. Foam cells took up DiI-Ox-LDL and DiI-myelin fragments in vitro while ependymoglia took up only DiI-myelin in vitro. Both cell types expressed the cysteine proteinase cathepsin K, with foam cells sequestering cathepsin K within the sealing ring adjacent to the culture substratum. The two cell types act as sinks for Ox-LDL and myelin fragments within the lesion site, with foamy macrophages showing more Ox-LDL uptake activity. Cathepsin K activity and cellular localization suggested that foamy macrophages digest ECM within reactive meninges, while ependymal cells act from within the spinal cord tissue during outgrowth into the lesion site, acting in complementary fashion. Small MNGCs also expressed lipid transporters and showed cathepsin K activity. Comparison of 3H-glucosamine uptake in ependymal cells and foam cells showed that only ependymal cells produce glycosaminoglycan and proteoglycan-containing ECM, while the cathepsin studies showed both cell types remove ECM. Interaction of foam cells and ependymoglia in vitro supported the dispersion of ependymal outgrowth associated with tissue reconstruction in Axolotl spinal cord regeneration.
Collapse
Affiliation(s)
- Nathaniel Enos
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Hidehito Takenaka
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Sarah Scott
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Hai V N Salfity
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Maia Kirk
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Margaret W Egar
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Deborah A Sarria
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Denise Slayback-Barry
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Teri Belecky-Adams
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| | - Ellen A G Chernoff
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
| |
Collapse
|
5
|
Suppression of miR-10a-5p in bone marrow mesenchymal stem cells enhances the therapeutic effect on spinal cord injury via BDNF. Neurosci Lett 2019; 714:134562. [PMID: 31626878 DOI: 10.1016/j.neulet.2019.134562] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/28/2019] [Accepted: 10/14/2019] [Indexed: 01/09/2023]
Abstract
BACKGROUNDS/AIMS Brain-derived neurotrophic factor (BDNF) plays a primary role in the maturation, proliferation, and differentiation of neuronal cells, can induce bone-marrow-derived mesenchymal stem cells (MSCs) to differentiate into nerve cells. This study aims to explore whether regulation of BDNF through microRNAs (miRNAs) in MSCs may further enhance the therapeutic effect on spinal cord injury (SCI). METHODS Bioinformatics analyses were done to predict miRNAs that target BDNF in MSCs. Dual-luciferase reporter gene assays were performed to verify the target relationship between microRNA and BDNF. We examined the mRNA and protein levels of BDNF in MSCs by RT-qPCR and Western blot, respectively. CCK 8 assay was chosen to assess cell viability. MSCs were transduced with miR-10a-5p-ASO, which were transplanted into rats that underwent SCI. The tissue integrity percentage, cavity volume, and Basso-Beattie-Bresnahan (BBB) scale were assessed. Neurofilament (NF) was detected using immunohistochemistry. Histological features of spinal cord tissues examined following HE staining. RESULTS MiR-10a-5p inhibited protein translation of BDNF, through binding to the 3'-UTR of the BDNF. MSCs transduced with MiR-10a-5p-ASO further increased the tissue integrity percentage, decreased cavity volume, and enhanced the recovery of BBB score in SCI model rats, compared to control MSCs. CONCLUSION Upregulation of BDNF by miR-10a-5p suppression in MSCs further improve the therapeutic potential of MSCs in treating SCI in rats.
Collapse
|
6
|
Sabin KZ, Jiang P, Gearhart MD, Stewart R, Echeverri K. AP-1 cFos/JunB/miR-200a regulate the pro-regenerative glial cell response during axolotl spinal cord regeneration. Commun Biol 2019; 2:91. [PMID: 30854483 PMCID: PMC6403268 DOI: 10.1038/s42003-019-0335-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 02/04/2019] [Indexed: 12/30/2022] Open
Abstract
Salamanders have the remarkable ability to functionally regenerate after spinal cord transection. In response to injury, GFAP+ glial cells in the axolotl spinal cord proliferate and migrate to replace the missing neural tube and create a permissive environment for axon regeneration. Molecular pathways that regulate the pro-regenerative axolotl glial cell response are poorly understood. Here we show axolotl glial cells up-regulate AP-1cFos/JunB after injury, which promotes a pro-regenerative glial cell response. Injury induced upregulation of miR-200a in glial cells supresses c-Jun expression in these cells. Inhibition of miR-200a during regeneration causes defects in axonal regrowth and transcriptomic analysis revealed that miR-200a inhibition leads to differential regulation of genes involved with reactive gliosis, the glial scar, extracellular matrix remodeling and axon guidance. This work identifies a unique role for miR-200a in inhibiting reactive gliosis in axolotl glial cells during spinal cord regeneration. Keith Sabin et al. showed that upregulation of the AP-1 complex, composed of c-Fos and JunB, in the axolotl spinal cord promotes a pro-regenerative glial cell response. This response is impaired by inhibition of miR-200a; suggesting an important role for this microRNA in axolotl spinal cord regeneration.
Collapse
Affiliation(s)
- Keith Z Sabin
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA.,Marine Biological Laboratory, Eugene Bell Center for Regenerative Biology and Tissue Engineering, Woods Hole, 02543, MA, USA
| | - Peng Jiang
- Morgridge Institute for Research, Madison, 53715, WI, USA
| | - Micah D Gearhart
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Ron Stewart
- Morgridge Institute for Research, Madison, 53715, WI, USA
| | - Karen Echeverri
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, 55455, USA. .,Marine Biological Laboratory, Eugene Bell Center for Regenerative Biology and Tissue Engineering, Woods Hole, 02543, MA, USA.
| |
Collapse
|
7
|
Freitas PD, Yandulskaya AS, Monaghan JR. Spinal Cord Regeneration in Amphibians: A Historical Perspective. Dev Neurobiol 2019; 79:437-452. [PMID: 30725532 DOI: 10.1002/dneu.22669] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 01/22/2019] [Accepted: 01/25/2019] [Indexed: 12/11/2022]
Abstract
In some vertebrates, a grave injury to the central nervous system (CNS) results in functional restoration, rather than in permanent incapacitation. Understanding how these animals mount a regenerative response by activating resident CNS stem cell populations is of critical importance in regenerative biology. Amphibians are of a particular interest in the field because the regenerative ability is present throughout life in urodele species, but in anuran species it is lost during development. Studying amphibians, who transition from a regenerative to a nonregenerative state, could give insight into the loss of ability to recover from CNS damage in mammals. Here, we highlight the current knowledge of spinal cord regeneration across vertebrates and identify commonalities and differences in spinal cord regeneration between amphibians.
Collapse
Affiliation(s)
- Polina D Freitas
- Department of Biology, Northeastern University, 360 Huntington Ave., 134 Mugar Hall, Boston, Massachusetts, 02115
| | - Anastasia S Yandulskaya
- Department of Biology, Northeastern University, 360 Huntington Ave., 134 Mugar Hall, Boston, Massachusetts, 02115
| | - James R Monaghan
- Department of Biology, Northeastern University, 360 Huntington Ave., 134 Mugar Hall, Boston, Massachusetts, 02115
| |
Collapse
|
8
|
A clinically relevant blunt spinal cord injury model in the regeneration competent axolotl ( Ambystoma mexicanum) tail. Exp Ther Med 2019; 17:2322-2328. [PMID: 30867717 PMCID: PMC6395952 DOI: 10.3892/etm.2019.7193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 01/16/2019] [Indexed: 12/30/2022] Open
Abstract
A randomized controlled and blinded animal trial was conducted in the axolotl (Ambystoma mexicanum), which has the ability to regenerate from transectional spinal cord injury (SCI). The objective of the present study was to investigate the axolotl's ability to regenerate from a blunt spinal cord trauma in a clinical setting. Axolotls were block-randomized to the intervention (n=6) or sham group (n=6). A laminectomy of two vertebrae at the level caudal to the hind limbs was performed. To induce a blunt SCI, a 25 g rod was released on the exposed spinal cord. Multiple modalities were applied at baseline (pre-surgery), and subsequently every third week for a total of 9 weeks. Gradient echo magnetic resonance imaging (MRI) was applied to assess anatomical regeneration. To support this non-invasive modality, regeneration was assessed by histology, and functional regeneration was investigated using swimming tests and functional neurological examinations. MRI suggested regeneration within 6 to 9 weeks. Histological analysis at 9 weeks confirmed regeneration; however, this regeneration was not complete. By the experimental end, all animals exhibited restored full neurological function. The present study demonstrated that the axolotl is capable of regenerating a contusion SCI; however, the duration of complete regeneration required further investigation.
Collapse
|
9
|
Differences in neural stem cell identity and differentiation capacity drive divergent regenerative outcomes in lizards and salamanders. Proc Natl Acad Sci U S A 2018; 115:E8256-E8265. [PMID: 30104374 DOI: 10.1073/pnas.1803780115] [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] [Indexed: 12/18/2022] Open
Abstract
While lizards and salamanders both exhibit the ability to regenerate amputated tails, the outcomes achieved by each are markedly different. Salamanders, such as Ambystoma mexicanum, regenerate nearly identical copies of original tails. Regenerated lizard tails, however, exhibit important morphological differences compared with originals. Some of these differences concern dorsoventral patterning of regenerated skeletal and spinal cord tissues; regenerated salamander tail tissues exhibit dorsoventral patterning, while regrown lizard tissues do not. Additionally, regenerated lizard tails lack characteristically roof plate-associated structures, such as dorsal root ganglia. We hypothesized that differences in neural stem cells (NSCs) found in the ependyma of regenerated spinal cords account for these divergent regenerative outcomes. Through a combination of immunofluorescent staining, RT-PCR, hedgehog regulation, and transcriptome analysis, we analyzed NSC-dependent tail regeneration. Both salamander and lizard Sox2+ NSCs form neurospheres in culture. While salamander neurospheres exhibit default roof plate identity, lizard neurospheres exhibit default floor plate. Hedgehog signaling regulates dorsalization/ventralization of salamander, but not lizard, NSCs. Examination of NSC differentiation potential in vitro showed that salamander NSCs are capable of neural differentiation into multiple lineages, whereas lizard NSCs are not, which was confirmed by in vivo spinal cord transplantations. Finally, salamander NSCs xenogeneically transplanted into regenerating lizard tail spinal cords were influenced by native lizard NSC hedgehog signals, which favored salamander NSC floor plate differentiation. These findings suggest that NSCs in regenerated lizard and salamander spinal cords are distinct cell populations, and these differences contribute to the vastly different outcomes observed in tail regeneration.
Collapse
|
10
|
Joven A, Simon A. Homeostatic and regenerative neurogenesis in salamanders. Prog Neurobiol 2018; 170:81-98. [PMID: 29654836 DOI: 10.1016/j.pneurobio.2018.04.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/20/2018] [Accepted: 04/07/2018] [Indexed: 01/02/2023]
Abstract
Large-scale regeneration in the adult central nervous system is a unique capacity of salamanders among tetrapods. Salamanders can replace neuronal populations, repair damaged nerve fibers and restore tissue architecture in retina, brain and spinal cord, leading to functional recovery. The underlying mechanisms have long been difficult to study due to the paucity of available genomic tools. Recent technological progress, such as genome sequencing, transgenesis and genome editing provide new momentum for systematic interrogation of regenerative processes in the salamander central nervous system. Understanding central nervous system regeneration also entails designing the appropriate molecular, cellular, and behavioral assays. Here we outline the organization of salamander brain structures. With special focus on ependymoglial cells, we integrate cellular and molecular processes of neurogenesis during developmental and adult homeostasis as well as in various injury models. Wherever possible, we correlate developmental and regenerative neurogenesis to the acquisition and recovery of behaviors. Throughout the review we place the findings into an evolutionary context for inter-species comparisons.
Collapse
Affiliation(s)
- Alberto Joven
- Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, 17177, Stockholm, Sweden.
| | - András Simon
- Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, 17177, Stockholm, Sweden.
| |
Collapse
|
11
|
Ghosh S, Hui SP. Axonal regeneration in zebrafish spinal cord. REGENERATION (OXFORD, ENGLAND) 2018; 5:43-60. [PMID: 29721326 PMCID: PMC5911453 DOI: 10.1002/reg2.99] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 03/09/2018] [Accepted: 03/13/2018] [Indexed: 12/12/2022]
Abstract
In the present review we discuss two interrelated events-axonal damage and repair-known to occur after spinal cord injury (SCI) in the zebrafish. Adult zebrafish are capable of regenerating axonal tracts and can restore full functionality after SCI. Unlike fish, axon regeneration in the adult mammalian central nervous system is extremely limited. As a consequence of an injury there is very little repair of disengaged axons and therefore functional deficit persists after SCI in adult mammals. In contrast, peripheral nervous system axons readily regenerate following injury and hence allow functional recovery both in mammals and fish. A better mechanistic understanding of these three scenarios could provide a more comprehensive insight into the success or failure of axonal regeneration after SCI. This review summarizes the present understanding of the cellular and molecular basis of axonal regeneration, in both the peripheral nervous system and the central nervous system, and large scale gene expression analysis is used to focus on different events during regeneration. The discovery and identification of genes involved in zebrafish spinal cord regeneration and subsequent functional experimentation will provide more insight into the endogenous mechanism of myelination and remyelination. Furthermore, precise knowledge of the mechanism underlying the extraordinary axonal regeneration process in zebrafish will also allow us to unravel the potential therapeutic strategies to be implemented for enhancing regrowth and remyelination of axons in mammals.
Collapse
Affiliation(s)
- Sukla Ghosh
- Department of BiophysicsMolecular Biology and BioinformaticsUniversity of Calcutta92 A. P. C. RoadKolkata 700009India
| | - Subhra Prakash Hui
- Department of BiophysicsMolecular Biology and BioinformaticsUniversity of Calcutta92 A. P. C. RoadKolkata 700009India
- Victor Chang Cardiac Research InstituteLowy Packer Building, 405 Liverpool StDarlinghurstNSW 2010Australia.
| |
Collapse
|
12
|
Lang DM, Romero-Alemán MDM, Dobson B, Santos E, Monzón-Mayor M. Nogo-A does not inhibit retinal axon regeneration in the lizardGallotia galloti. J Comp Neurol 2016; 525:936-954. [DOI: 10.1002/cne.24112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 06/19/2016] [Accepted: 07/08/2016] [Indexed: 01/07/2023]
Affiliation(s)
- Dirk M. Lang
- Division of Physiological Sciences, Department of Human Biology; University of Cape Town; Observatory 7925 South Africa
| | - Maria del Mar Romero-Alemán
- Research Institute of Biomedical and Health Sciences; University of Las Palmas de Gran Canaria; 35016 Las Palmas Canary Islands Spain
| | - Bryony Dobson
- Division of Physiological Sciences, Department of Human Biology; University of Cape Town; Observatory 7925 South Africa
| | - Elena Santos
- Research Institute of Biomedical and Health Sciences; University of Las Palmas de Gran Canaria; 35016 Las Palmas Canary Islands Spain
| | - Maximina Monzón-Mayor
- Research Institute of Biomedical and Health Sciences; University of Las Palmas de Gran Canaria; 35016 Las Palmas Canary Islands Spain
| |
Collapse
|
13
|
Ghosh S, Hui SP. Regeneration of Zebrafish CNS: Adult Neurogenesis. Neural Plast 2016; 2016:5815439. [PMID: 27382491 PMCID: PMC4921647 DOI: 10.1155/2016/5815439] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/18/2016] [Indexed: 12/13/2022] Open
Abstract
Regeneration in the animal kingdom is one of the most fascinating problems that have allowed scientists to address many issues of fundamental importance in basic biology. However, we came to know that the regenerative capability may vary across different species. Among vertebrates, fish and amphibians are capable of regenerating a variety of complex organs through epimorphosis. Zebrafish is an excellent animal model, which can repair several organs like damaged retina, severed spinal cord, injured brain and heart, and amputated fins. The focus of the present paper is on spinal cord regeneration in adult zebrafish. We intend to discuss our current understanding of the cellular and molecular mechanism(s) that allows formation of proliferating progenitors and controls neurogenesis, which involve changes in epigenetic and transcription programs. Unlike mammals, zebrafish retains radial glia, a nonneuronal cell type in their adult central nervous system. Injury induced proliferation involves radial glia which proliferate, transcribe embryonic genes, and can give rise to new neurons. Recent technological development of exquisite molecular tools in zebrafish, such as cell ablation, lineage analysis, and novel and substantial microarray, together with advancement in stem cell biology, allowed us to investigate how progenitor cells contribute to the generation of appropriate structures and various underlying mechanisms like reprogramming.
Collapse
Affiliation(s)
- Sukla Ghosh
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| | - Subhra Prakash Hui
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| |
Collapse
|
14
|
Hui SP, Nag TC, Ghosh S. Characterization of Proliferating Neural Progenitors after Spinal Cord Injury in Adult Zebrafish. PLoS One 2015; 10:e0143595. [PMID: 26630262 PMCID: PMC4667880 DOI: 10.1371/journal.pone.0143595] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/06/2015] [Indexed: 12/14/2022] Open
Abstract
Zebrafish can repair their injured brain and spinal cord after injury unlike adult mammalian central nervous system. Any injury to zebrafish spinal cord would lead to increased proliferation and neurogenesis. There are presences of proliferating progenitors from which both neuronal and glial loss can be reversed by appropriately generating new neurons and glia. We have demonstrated the presence of multiple progenitors, which are different types of proliferating populations like Sox2+ neural progenitor, A2B5+ astrocyte/ glial progenitor, NG2+ oligodendrocyte progenitor, radial glia and Schwann cell like progenitor. We analyzed the expression levels of two common markers of dedifferentiation like msx-b and vimentin during regeneration along with some of the pluripotency associated factors to explore the possible role of these two processes. Among the several key factors related to pluripotency, pou5f1 and sox2 are upregulated during regeneration and associated with activation of neural progenitor cells. Uncovering the molecular mechanism for endogenous regeneration of adult zebrafish spinal cord would give us more clues on important targets for future therapeutic approach in mammalian spinal cord repair and regeneration.
Collapse
Affiliation(s)
- Subhra Prakash Hui
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, A. P. C. Road, Kolkata—700009, India
| | - Tapas Chandra Nag
- Department of Anatomy, All India Institute of Medical Sciences, New Delhi- 110029, India
| | - Sukla Ghosh
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92, A. P. C. Road, Kolkata—700009, India
- * E-mail:
| |
Collapse
|
15
|
Seiler S, Di Santo S, Widmer HR. Non-canonical actions of Nogo-A and its receptors. Biochem Pharmacol 2015; 100:28-39. [PMID: 26348872 DOI: 10.1016/j.bcp.2015.08.113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/31/2015] [Indexed: 12/13/2022]
Abstract
Nogo-A is a myelin associated protein and one of the most potent neurite growth inhibitors in the central nervous system. Interference with Nogo-A signaling has thus been investigated as therapeutic target to promote functional recovery in CNS injuries. Still, the finding that Nogo-A presents a fairly ubiquitous expression in many types of neurons in different brain regions, in the eye and even in the inner ear suggests for further functions besides the neurite growth repression. Indeed, a growing number of studies identified a variety of functions including regulation of neuronal stem cells, modulation of microglial activity, inhibition of angiogenesis and interference with memory formation. Aim of the present commentary is to draw attention on these less well-known and sometimes controversial roles of Nogo-A. Furthermore, we are addressing the role of Nogo-A in neuropathological conditions such as ischemic stroke, schizophrenia and neurodegenerative diseases.
Collapse
Affiliation(s)
- Stefanie Seiler
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Stefano Di Santo
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland
| | - Hans Rudolf Widmer
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University Hospital Bern and University of Bern, CH-3010 Bern, Switzerland.
| |
Collapse
|
16
|
Wang JW, Yang JF, Ma Y, Hua Z, Guo Y, Gu XL, Zhang YF. Nogo-A expression dynamically varies after spinal cord injury. Neural Regen Res 2015; 10:225-9. [PMID: 25883620 PMCID: PMC4392669 DOI: 10.4103/1673-5374.152375] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2014] [Indexed: 01/22/2023] Open
Abstract
The mechanism involved in neural regeneration after spinal cord injury is unclear. The myelin-derived protein Nogo-A, which is specific to the central nervous system, has been identified to negatively affect the cytoskeleton and growth program of axotomized neurons. Studies have shown that Nogo-A exerts immediate and chronic inhibitory effects on neurite outgrowth. In vivo, inhibitors of Nogo-A have been shown to lead to a marked enhancement of regenerative axon extension. We established a spinal cord injury model in rats using a free-falling weight drop device to subsequently investigate Nogo-A expression. Nogo-A mRNA and protein expression and immunoreactivity were detected in spinal cord tissue using real-time quantitative PCR, immunohistochemistry and western blot analysis. At 24 hours after spinal cord injury, Nogo-A protein and mRNA expression was low in the injured group compared with control and sham-operated groups. The levels then continued to drop further and were at their lowest at 3 days, rapidly rose to a peak after 7 days, and then gradually declined again after 14 days. These changes were observed at both the mRNA and protein level. The transient decrease observed early after injury followed by high levels for a few days indicates Nogo-A expression is time dependent. This may contribute to the lack of regeneration in the central nervous system after spinal cord injury. The dynamic variation of Nogo-A should be taken into account in the treatment of spinal cord injury.
Collapse
Affiliation(s)
- Jian-wei Wang
- Wuxi Hospital of Traditional Chinese Medicine, Institute of Orthopedics and Traumatology of Nanjing University of Chinese Medicine, Wuxi, Jiangsu Province, China
| | - Jun-feng Yang
- Wuxi Hospital of Traditional Chinese Medicine, Institute of Orthopedics and Traumatology of Nanjing University of Chinese Medicine, Wuxi, Jiangsu Province, China
| | - Yong Ma
- Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
| | - Zhen Hua
- Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
| | - Yang Guo
- Wuxi Hospital of Traditional Chinese Medicine, Institute of Orthopedics and Traumatology of Nanjing University of Chinese Medicine, Wuxi, Jiangsu Province, China
| | - Xiao-lin Gu
- Nanjing University of Chinese Medicine, Nanjing, Jiangsu Province, China
| | - Ya-feng Zhang
- Wuxi Hospital of Traditional Chinese Medicine, Institute of Orthopedics and Traumatology of Nanjing University of Chinese Medicine, Wuxi, Jiangsu Province, China
| |
Collapse
|
17
|
Bloom O. Non-mammalian model systems for studying neuro-immune interactions after spinal cord injury. Exp Neurol 2014; 258:130-40. [PMID: 25017894 PMCID: PMC4099969 DOI: 10.1016/j.expneurol.2013.12.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Revised: 12/24/2013] [Accepted: 12/26/2013] [Indexed: 01/09/2023]
Abstract
Mammals exhibit poor recovery after injury to the spinal cord, where the loss of neurons and neuronal connections can be functionally devastating. In contrast, it has long been appreciated that many non-mammalian vertebrate species exhibit significant spontaneous functional recovery after spinal cord injury (SCI). Identifying the biological responses that support an organism's inability or ability to recover function after SCI is an important scientific and medical question. While recent advances have been made in understanding the responses to SCI in mammals, we remain without an effective clinical therapy for SCI. A comparative biological approach to understanding responses to SCI in non-mammalian vertebrates will yield important insights into mechanisms that promote recovery after SCI. Presently, mechanistic studies aimed at elucidating responses, both intrinsic and extrinsic to neurons, that result in different regenerative capacities after SCI across vertebrates are just in their early stages. There are several inhibitory mechanisms proposed to impede recovery from SCI in mammals, including reactive gliosis and scarring, myelin associated proteins, and a suboptimal immune response. One hypothesis to explain the robust regenerative capacity of several non-mammalian vertebrates is a lack of some or all of these inhibitory signals. This review presents the current knowledge of immune responses to SCI in several non-mammalian species that achieve anatomical and functional recovery after SCI. This subject is of growing interest, as studies increasingly show both beneficial and detrimental roles of the immune response following SCI in mammals. A long-term goal of biomedical research in all experimental models of SCI is to understand how to promote functional recovery after SCI in humans. Therefore, understanding immune responses to SCI in non-mammalian vertebrates that achieve functional recovery spontaneously may identify novel strategies to modulate immune responses in less regenerative species and promote recovery after SCI.
Collapse
Affiliation(s)
- Ona Bloom
- The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA; The Hofstra North Shore-LIJ School of Medicine, Hempstead Turnpike, Hempstead, NY 11549, USA.
| |
Collapse
|
18
|
Diaz Quiroz JF, Tsai E, Coyle M, Sehm T, Echeverri K. Precise control of miR-125b levels is required to create a regeneration-permissive environment after spinal cord injury: a cross-species comparison between salamander and rat. Dis Model Mech 2014; 7:601-11. [PMID: 24719025 PMCID: PMC4036468 DOI: 10.1242/dmm.014837] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Most spinal cord injuries lead to permanent paralysis in mammals. By contrast, the remarkable regenerative abilities of salamanders enable full functional recovery even from complete spinal cord transections. The molecular differences underlying this evolutionary divergence between mammals and amphibians are poorly understood. We focused on upstream regulators of gene expression as primary entry points into this question. We identified a group of microRNAs (miRNAs) that are conserved between the Mexican axolotl salamander (Ambystoma mexicanum) and mammals but show marked cross-species differences in regulation patterns following spinal cord injury. We found that precise post-injury levels of one of these miRNAs (miR-125b) is essential for functional recovery, and guides correct regeneration of axons through the lesion site in a process involving the direct downstream target Sema4D in axolotls. Translating these results to a mammalian model, we increased miR-125b levels in the rat through mimic treatments following spinal cord transection. These treatments downregulated Sema4D and other glial-scar-related genes, and enhanced the animal’s functional recovery. Our study identifies a key regulatory molecule conserved between salamander and mammal, and shows that the expression of miR-125b and Sema4D must be carefully controlled in the right cells at the correct level to promote regeneration. We also show that these molecular components of the salamander’s regeneration-permissive environment can be experimentally harnessed to improve treatment outcomes for mammalian spinal cord injuries.
Collapse
Affiliation(s)
- Juan Felipe Diaz Quiroz
- University of Minnesota, Department of Genetics, Cell Biology and Development, Stem Cell Institute, 2001 6th St SE, Minneapolis, MN 55455, USA
| | - Eve Tsai
- Ottawa Hospital Research Institute, Ottowa, ON K1H 8L6, Canada
| | - Matthew Coyle
- Ottawa Hospital Research Institute, Ottowa, ON K1H 8L6, Canada
| | - Tina Sehm
- University of Erlangen-Nürnberg, Department of Neurosurgery, 91054 Erlangen, Germany
| | - Karen Echeverri
- University of Minnesota, Department of Genetics, Cell Biology and Development, Stem Cell Institute, 2001 6th St SE, Minneapolis, MN 55455, USA.
| |
Collapse
|
19
|
Axonal regeneration after spinal cord injury in zebrafish and mammals: differences, similarities, translation. Neurosci Bull 2013; 29:402-10. [PMID: 23893428 DOI: 10.1007/s12264-013-1361-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/09/2013] [Indexed: 10/26/2022] Open
Abstract
Spinal cord injury (SCI) in mammals results in functional deficits that are mostly permanent due in part to the inability of severed axons to regenerate. Several types of growth-inhibitory molecules expressed at the injury site contribute to this regeneration failure. The responses of axons to these inhibitors vary greatly within and between organisms, reflecting axons' characteristic intrinsic propensity for regeneration. In the zebrafish (Danio rerio) many but not all axons exhibit successful regeneration after SCI. This review presents and compares the intrinsic and extrinsic determinants of axonal regeneration in the injured spinal cord in mammals and zebrafish. A better understanding of the molecules and molecular pathways underlying the remarkable individualism among neurons in mature zebrafish may support the development of therapies for SCI and their translation to the clinic.
Collapse
|