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Liao JX, Zhu FQ, Liu YY, Liu SC, Liu ZX, Zhang WJ. The role of olfactory ensheathing cells in the repair of nerve injury. Eur J Pharmacol 2024; 966:176346. [PMID: 38246329 DOI: 10.1016/j.ejphar.2024.176346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/23/2024]
Abstract
Cell transplantation has brought about a breakthrough in the treatment of nerve injuries, and the efficacy of cell transplantation compared to drug and surgical therapies is very exciting. In terms of transplantation targets, the classic cells include neural stem cells (NSCs) and Schwann cells, while a class of cells that can exist and renew throughout the life of the nervous system - olfactory ensheathing cells (OECs) - has recently been discovered in the olfactory system. OECs not only encircle the olfactory nerves but also act as macrophages and play an innate immune role. OECs can also undergo reprogramming to transform into neurons and survive and mature after transplantation. Currently, many studies have confirmed the repairing effect of OECs after transplantation into injured nerves, and safe and effective results have been obtained in clinical trials. However, the specific repair mechanism of OECs among them is not quite clear. For this purpose, we focus here on the repair mechanisms of OECs, which are summarized as follows: neuroprotection, secretion of bioactive factors, limitation of inflammation and immune regulation, promotion of myelin and axonal regeneration, and promotion of vascular proliferation. In addition, integrating the aspects of harvesting, purification, and prognosis, we found that OECs may be more suitable for transplantation than NSCs and Schwann cells, but this does not completely discard the value of these classical cells. Overall, OECs are considered to be one of the most promising transplantation targets for the treatment of nerve injury disorders.
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Affiliation(s)
- Jun-Xiang Liao
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Fu-Qi Zhu
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Yi-Yi Liu
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Si-Cheng Liu
- The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Zeng-Xu Liu
- School of Basic Medicine, Nanchang University, Nanchang City, Jiangxi province, 343000, China
| | - Wen-Jun Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi province, 343000, China.
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2
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Gilmour AD, Reshamwala R, Wright AA, Ekberg JAK, St John JA. Optimizing Olfactory Ensheathing Cell Transplantation for Spinal Cord Injury Repair. J Neurotrauma 2021; 37:817-829. [PMID: 32056492 DOI: 10.1089/neu.2019.6939] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Cell transplantation constitutes an important avenue for development of new treatments for spinal cord injury (SCI). These therapies are aimed at supporting neural repair and/or replacing lost cells at the injury site. To date, various cell types have been trialed, with most studies focusing on different types of stem cells or glial cells. Here, we review commonly used cell transplantation approaches for spinal cord injury (SCI) repair, with focus on transplantation of olfactory ensheathing cells (OECs), the glial cells of the primary olfactory nervous system. OECs are promising candidates for promotion of neural repair given that they support continuous regeneration of the olfactory nerve that occurs throughout life. Further, OECs can be accessed from the nasal mucosa (olfactory neuroepithelium) at the roof of the nasal cavity and can be autologously transplanted. OEC transplantation has been trialed in many animal models of SCI, as well as in human clinical trials. While several studies have been promising, outcomes are variable and the method needs improvement to enhance aspects such as cell survival, integration, and migration. As a case study, we include the approaches used by our team (the Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia) to address the current problems with OEC transplantation and discuss how the therapeutic potential of OEC transplantation can be improved. Our approach includes discovery research to improve our knowledge of OEC biology, identifying natural and synthetic compounds to stimulate the neural repair properties of OECs, and designing three-dimensional cell constructs to create stable and transplantable cell structures.
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Affiliation(s)
- Aaron D Gilmour
- Clem Jones Centre for Neurobiology and Stem Cell Research and Griffith University, Nathan, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
| | - Ronak Reshamwala
- Clem Jones Centre for Neurobiology and Stem Cell Research and Griffith University, Nathan, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Alison A Wright
- Clem Jones Centre for Neurobiology and Stem Cell Research and Griffith University, Nathan, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
| | - Jenny A K Ekberg
- Clem Jones Centre for Neurobiology and Stem Cell Research and Griffith University, Nathan, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - James A St John
- Clem Jones Centre for Neurobiology and Stem Cell Research and Griffith University, Nathan, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
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3
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Chen M, Vial ML, Gee L, Davis RA, St John JA, Ekberg JAK. The plant natural product 2-methoxy-1,4-naphthoquinone stimulates therapeutic neural repair properties of olfactory ensheathing cells. Sci Rep 2020; 10:951. [PMID: 31969642 PMCID: PMC6976649 DOI: 10.1038/s41598-020-57793-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 12/11/2019] [Indexed: 01/04/2023] Open
Abstract
Olfactory ensheathing cells (OECs) are crucial for promoting the regeneration of the primary olfactory nervous system that occurs throughout life. Transplantation of OECs has emerged as a promising therapy for nervous system injuries, in particular for spinal cord injury repair. Functional outcomes in both animals and humans are, however, highly variable, primarily because it is difficult to rapidly obtain enough OECs for transplantation. Compounds which can stimulate OEC proliferation without changing the phenotype of the cells are therefore highly sought after. Additionally, compounds which can stimulate favourable cell behaviours such as migration and phagocytic activity are desirable. We conducted a medium-throughput screen testing the Davis open access natural product-based library (472 compounds) and subsequently identified the known plant natural product 2-methoxy-1,4-naphthoquinone as a stimulant of OEC viability. We showed that 2-methoxy-1,4-naphthoquinone: (i) strongly stimulates proliferation over several weeks in culture whilst maintaining the OEC phenotype; (ii) stimulates the phagocytic activity of OECs, and (iii) modulates the cell cycle. We also identified the transcription factor Nrf2 as the compound’s potential molecular target. From these extensive investigations we conclude that 2-methoxy-1,4-naphthoquinone may enhance the therapeutic potential of OECs by stimulating proliferation prior to transplantation.
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Affiliation(s)
- M Chen
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, 4222, Australia
| | - M L Vial
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, 4222, Australia
| | - L Gee
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111, QLD, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, 4222, Australia
| | - R A Davis
- Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia
| | - J A St John
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia.,Menzies Health Institute Queensland, Griffith University, Southport, QLD, 4222, Australia
| | - J A K Ekberg
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111, QLD, Australia. .,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, 4111, Australia. .,Menzies Health Institute Queensland, Griffith University, Southport, QLD, 4222, Australia.
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4
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Walkden H, Delbaz A, Nazareth L, Batzloff M, Shelper T, Beacham IR, Chacko A, Shah M, Beagley KW, Tello Velasquez J, St John JA, Ekberg JAK. Burkholderia pseudomallei invades the olfactory nerve and bulb after epithelial injury in mice and causes the formation of multinucleated giant glial cells in vitro. PLoS Negl Trop Dis 2020; 14:e0008017. [PMID: 31978058 PMCID: PMC7002012 DOI: 10.1371/journal.pntd.0008017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 02/05/2020] [Accepted: 12/27/2019] [Indexed: 12/14/2022] Open
Abstract
The infectious disease melioidosis is caused by the bacterium Burkholderia pseudomallei. Melioidosis is characterised by high mortality and morbidity and can involve the central nervous system (CNS). We have previously discovered that B. pseudomallei can infect the CNS via the olfactory and trigeminal nerves in mice. We have shown that the nerve path is dependent on mouse strain, with outbred mice showing resistance to olfactory nerve infection. Damage to the nasal epithelium by environmental factors is common, and we hypothesised that injury to the olfactory epithelium may increase the vulnerability of the olfactory nerve to microbial insult. We therefore investigated this, using outbred mice that were intranasally inoculated with B. pseudomallei, with or without methimazole-induced injury to the olfactory neuroepithelium. Methimazole-mediated injury resulted in increased B. pseudomallei invasion of the olfactory epithelium, and only in pre-injured animals were bacteria found in the olfactory nerve and bulb. In vitro assays demonstrated that B. pseudomallei readily infected glial cells isolated from the olfactory and trigeminal nerves (olfactory ensheathing cells and trigeminal Schwann cells, respectively). Bacteria were degraded by some cells but persisted in other cells, which led to the formation of multinucleated giant cells (MNGCs), with olfactory ensheathing cells less likely to form MNGCs than Schwann cells. Double Cap mutant bacteria, lacking the protein BimA, did not form MNGCs. These data suggest that injuries to the olfactory epithelium expose the primary olfactory nervous system to bacterial invasion, which can then result in CNS infection with potential pathogenic consequences for the glial cells.
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Affiliation(s)
- Heidi Walkden
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
| | - Ali Delbaz
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
| | - Lynn Nazareth
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
| | - Michael Batzloff
- Institute for Glycomics, Griffith University, Southport, Australia
| | - Todd Shelper
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
| | - Ifor R. Beacham
- Institute for Glycomics, Griffith University, Southport, Australia
| | - Anu Chacko
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
| | - Megha Shah
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
| | - Kenneth W. Beagley
- Institute for Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | | | - James A. St John
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Australia
| | - Jenny A. K. Ekberg
- Menzies Health Institute Queensland, Griffith University, Southport, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Australia
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5
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Reshamwala R, Shah M, Belt L, Ekberg JAK, St John JA. Reliable cell purification and determination of cell purity: crucial aspects of olfactory ensheathing cell transplantation for spinal cord repair. Neural Regen Res 2020; 15:2016-2026. [PMID: 32394949 PMCID: PMC7716040 DOI: 10.4103/1673-5374.282218] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Transplantation of olfactory ensheathing cells, the glia of the primary olfactory nervous system, has been trialed for spinal cord injury repair with promising but variable outcomes in animals and humans. Olfactory ensheathing cells can be harvested either from the lamina propria beneath the neuroepithelium in the nasal cavity, or from the olfactory bulb in the brain. As these areas contain several other cell types, isolating and purifying olfactory ensheathing cells is a critical part of the process. It is largely unknown how contaminating cells such as fibroblasts, other glial cell types and supporting cells affect olfactory ensheathing cell function post-transplantation; these cells may also cause unwanted side-effects. It is also, however, possible that the presence of some of the contaminant cells can improve outcomes. Here, we reviewed the last decade of olfactory ensheathing cell transplantation studies in rodents, with a focus on olfactory ensheathing cell purity. We analyzed how purification methods and resultant cell purity differed between olfactory mucosa- and olfactory bulb-derived cell preparations. We analyzed how the studies reported on olfactory ensheathing cell purity and which criteria were used to define cells as olfactory ensheathing cells. Finally, we analyzed the correlation between cell purity and transplantation outcomes. We found that olfactory bulb-derived olfactory ensheathing cell preparations are typically purer than mucosa-derived preparations. We concluded that there is an association between high olfactory ensheathing cell purity and favourable outcomes, but the lack of olfactory ensheathing cell-specific markers severely hampers the field.
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Affiliation(s)
- Ronak Reshamwala
- Griffith Institute for Drug Discovery, Griffith University, Brisbane; Menzies Health Institute Queensland, Griffith University, Southport; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - Megha Shah
- Menzies Health Institute Queensland, Griffith University, Southport; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - Lucy Belt
- Menzies Health Institute Queensland, Griffith University, Southport; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - Jenny A K Ekberg
- Griffith Institute for Drug Discovery, Griffith University, Brisbane; Menzies Health Institute Queensland, Griffith University, Southport; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
| | - James A St John
- Griffith Institute for Drug Discovery, Griffith University, Brisbane; Menzies Health Institute Queensland, Griffith University, Southport; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, QLD, Australia
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6
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Reshamwala R, Shah M, St John J, Ekberg J. Survival and Integration of Transplanted Olfactory Ensheathing Cells are Crucial for Spinal Cord Injury Repair: Insights from the Last 10 Years of Animal Model Studies. Cell Transplant 2019; 28:132S-159S. [PMID: 31726863 PMCID: PMC7016467 DOI: 10.1177/0963689719883823] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/03/2019] [Accepted: 09/27/2019] [Indexed: 12/15/2022] Open
Abstract
Olfactory ensheathing cells (OECs), the glial cells of the primary olfactory nervous system, support the natural regeneration of the olfactory nerve that occurs throughout life. OECs thus exhibit unique properties supporting neuronal survival and growth. Transplantation of OECs is emerging as a promising treatment for spinal cord injury; however, outcomes in both animals and humans are variable and the method needs improvement and standardization. A major reason for the discrepancy in functional outcomes is the variability in survival and integration of the transplanted cells, key factors for successful spinal cord regeneration. Here, we review the outcomes of OEC transplantation in rodent models over the last 10 years, with a focus on survival and integration of the transplanted cells. We identify the key factors influencing OEC survival: injury type, source of transplanted cells, co-transplantation with other cell types, number and concentration of cells, method of delivery, and time of transplantation after the injury. We found that two key issues are hampering optimization and standardization of OEC transplantation: lack of (1) reliable methods for identifying transplanted cells, and (2) three-dimensional systems for OEC delivery. To develop OEC transplantation as a successful and standardized therapy for spinal cord injury, we must address these issues and increase our understanding of the complex parameters influencing OEC survival.
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Affiliation(s)
- Ronak Reshamwala
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, Queensland, Australia
| | - Megha Shah
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, Queensland, Australia
| | - James St John
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, Queensland, Australia
| | - Jenny Ekberg
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Brisbane, Queensland, Australia
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7
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Wright AA, Todorovic M, Murtaza M, St John JA, Ekberg JA. Macrophage migration inhibitory factor and its binding partner HTRA1 are expressed by olfactory ensheathing cells. Mol Cell Neurosci 2019; 102:103450. [PMID: 31794879 DOI: 10.1016/j.mcn.2019.103450] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/10/2019] [Accepted: 11/27/2019] [Indexed: 01/10/2023] Open
Abstract
Macrophage migration inhibitory factor (MIF) is an important regulator of innate immunity with key roles in neural regeneration and responses to pathogens, amongst a multitude of other functions. The expression of MIF and its binding partners has been characterised throughout the nervous system, with one key exception: the primary olfactory nervous system. Here, we showed in young mice (postnatal day 10) that MIF is expressed in the olfactory nerve by olfactory ensheathing glial cells (OECs) and by olfactory nerve fibroblasts. We also examined the expression of potential binding partners for MIF, and found that the serine protease HTRA1, known to be inhibited by MIF, was also expressed at high levels by OECs and olfactory fibroblasts in vivo and in vitro. We also demonstrated that MIF mediated segregation between OECs and J774a.1 cells (a monocyte/macrophage cell line) in co-culture, which suggests that MIF contributes to the fact that macrophages are largely absent from olfactory nerve fascicles. Phagocytosis assays of axonal debris demonstrated that MIF strongly stimulates phagocytosis by OECs, which indicates that MIF may play a role in the response of OECs to the continual turnover of olfactory axons that occurs throughout life.
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Affiliation(s)
- A A Wright
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia; Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - M Todorovic
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia; Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia; School of Nursing and Midwifery, Griffith University, Nathan, Queensland, Australia
| | - M Murtaza
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia; Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - J A St John
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia; Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - J A Ekberg
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia; Griffith Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, Australia; Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia.
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8
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Stierli S, Imperatore V, Lloyd AC. Schwann cell plasticity-roles in tissue homeostasis, regeneration, and disease. Glia 2019; 67:2203-2215. [PMID: 31215712 DOI: 10.1002/glia.23643] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 12/12/2022]
Abstract
How tissues are maintained over a lifetime and repaired following injury are fundamental questions in biology with a disruption to these processes underlying pathologies such as cancer and degenerative disorders. It is becoming increasingly clear that each tissue has a distinct mechanism to maintain homeostasis and respond to injury utilizing different types of stem/progenitor cell populations depending on the insult and/or with a contribution from more differentiated cells that are able to dedifferentiate to aid tissue regeneration. Peripheral nerves are highly quiescent yet show remarkable regenerative capabilities. Remarkably, there is no evidence for a classical stem cell population, rather all cell-types within the nerve are able to proliferate to produce new nerve tissue. Co-ordinating the regeneration of this tissue are Schwann cells (SCs), the main glial cells of the peripheral nervous system. SCs exist in architecturally stable structures that can persist for the lifetime of an animal, however, they are not postmitotic, in that following injury they are reprogrammed at high efficiency to a progenitor-like state, with these cells acting to orchestrate the nerve regeneration process. During nerve regeneration, SCs show little plasticity, maintaining their identity in the repaired tissue. However, once free of the nerve environment they appear to exhibit increased plasticity with reported roles in the repair of other tissues. In this review, we will discuss the mechanisms underlying the homeostasis and regeneration of peripheral nerves and how reprogrammed progenitor-like SCs have broader roles in the repair of other tissues with implications for pathologies such as cancer.
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Affiliation(s)
- Salome Stierli
- MRC LMCB, University College London, Gower Street, London, WC1E 6BT, UK
| | | | - Alison C Lloyd
- MRC LMCB, University College London, Gower Street, London, WC1E 6BT, UK
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9
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Murtaza M, Chacko A, Delbaz A, Reshamwala R, Rayfield A, McMonagle B, St John JA, Ekberg JAK. Why are olfactory ensheathing cell tumors so rare? Cancer Cell Int 2019; 19:260. [PMID: 31632194 PMCID: PMC6788004 DOI: 10.1186/s12935-019-0989-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 10/01/2019] [Indexed: 01/08/2023] Open
Abstract
The glial cells of the primary olfactory nervous system, olfactory ensheathing cells (OECs), are unusual in that they rarely form tumors. Only 11 cases, all of which were benign, have been reported to date. In fact, the existence of OEC tumors has been debated as the tumors closely resemble schwannomas (Schwann cell tumors), and there is no definite method for distinguishing the two tumor types. OEC transplantation is a promising therapeutic approach for nervous system injuries, and the fact that OECs are not prone to tumorigenesis is therefore vital. However, why OECs are so resistant to neoplastic transformation remains unknown. The primary olfactory nervous system is a highly dynamic region which continuously undergoes regeneration and neurogenesis throughout life. OECs have key roles in this process, providing structural and neurotrophic support as well as phagocytosing the axonal debris resulting from turnover of neurons. The olfactory mucosa and underlying tissue is also frequently exposed to infectious agents, and OECs have key innate immune roles preventing microbes from invading the central nervous system. It is possible that the unique biological functions of OECs, as well as the dynamic nature of the primary olfactory nervous system, relate to the low incidence of OEC tumors. Here, we summarize the known case reports of OEC tumors, discuss the difficulties of correctly diagnosing them, and examine the possible reasons for their rare incidence. Understanding why OECs rarely form tumors may open avenues for new strategies to combat tumorigenesis in other regions of the nervous system.
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Affiliation(s)
- Mariyam Murtaza
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
| | - Anu Chacko
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
| | - Ali Delbaz
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
| | - Ronak Reshamwala
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
| | - Andrew Rayfield
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
| | - Brent McMonagle
- 4Department of Otolaryngology-Head and Neck Surgery, Gold Coast University Hospital, 1 Hospital Boulevard, Southport, QLD 4215 Australia
| | - James A St John
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
| | - Jenny A K Ekberg
- 1Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD 4111 Australia.,2Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia.,3Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, 4111 Australia
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10
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Salazar I, Sanchez-Quinteiro P, Barrios AW, López Amado M, Vega JA. Anatomy of the olfactory mucosa. HANDBOOK OF CLINICAL NEUROLOGY 2019; 164:47-65. [PMID: 31604563 DOI: 10.1016/b978-0-444-63855-7.00004-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The classic notion that humans are microsmatic animals was born from comparative anatomy studies showing the reduction in the size of both the olfactory bulbs and the limbic brain relative to the whole brain. However, the human olfactory system contains a number of neurons comparable to that of most other mammals, and humans have exquisite olfactory abilities. Major advances in molecular and genetic research have resulted in the identification of extremely large gene families that express receptors for sensing odors. Such advances have led to a renaissance of studies focused on both human and nonhuman aspects of olfactory physiology and function. Evidence that olfactory dysfunction is among the earliest signs of a number of neurodegenerative and neuropsychiatric disorders has led to considerable interest in the use of olfactory epithelial biopsies for potentially identifying such disorders. Moreover, the unique features of the olfactory ensheathing cells have made the olfactory mucosa a promising and unexpected source of cells for treating spinal cord injuries and other neural injuries in which cell guidance is critical. The olfactory system of humans and other primates differs in many ways from that of other species. In this chapter we provide an overview of the anatomy of not only the human olfactory mucosa but of mucosae from a range of mammals from which more detailed information is available. Basic information regarding the general organization of the olfactory mucosa, including its receptor cells and the large number of other cell types critical for their maintenance and function, is provided. Cross-species comparisons are made when appropriate. The polemic issue of the human vomeronasal organ in both the adult and fetus is discussed, along with recent findings regarding olfactory subsystems within the nose of a number of mammals (e.g., the septal organ and Grüneberg ganglion).
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Affiliation(s)
- Ignacio Salazar
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Unit of Anatomy and Embryology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain.
| | - Pablo Sanchez-Quinteiro
- Department of Anatomy, Animal Production and Veterinary Clinical Sciences, Unit of Anatomy and Embryology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain
| | - Arthur W Barrios
- Laboratory of Histology, Embryology and Animal Pathology, Faculty of Veterinary Medicine, University Nacional Mayor of San Marcos, Lima, Peru
| | - Manuel López Amado
- Department of Otorhinolaryngology, University Hospital La Coruña, La Coruña, Spain
| | - José A Vega
- Unit of Anatomy, Department of Morphology and Cell Biology, Faculty of Medicine, University of Oviedo, Oviedo, Spain
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11
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The Grueneberg olfactory organ neuroepithelium recovers after injury. Brain Res 2018; 1688:65-72. [PMID: 29567386 DOI: 10.1016/j.brainres.2018.03.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 03/07/2018] [Accepted: 03/15/2018] [Indexed: 11/21/2022]
Abstract
The Grueneberg organ (also termed Grueneberg ganglion) is an olfactory subsystem at the rostral nasal septum of rodents, and has been suggested to exist also in humans. Grueneberg organ neurons respond to coldness and alarm pheromones, but the anatomical arrangement and regenerative capacity are not fully characterised. We examined the relationship between the glia and the neurons using crosses of two transgenic mouse lines, S100ß-DsRed and OMP-ZsGreen, to visualise olfactory ensheathing cells (OECs) and Grueneberg olfactory neurons, respectively. Within the epithelium, Grueneberg organ OECs were in direct contact with Grueneberg organ neuron cell bodies. Individual axons from the neurons initially grew over the surface of the OECs before forming larger fascicles consisting of numerous axons and OECs. Considering the location of the Grueneberg organ so close to the external environment, it may be that the Grueneberg neurons are likely to be subject to damage suggesting that as in other olfactory regions there is a capacity for recovery after injury. Here, we used a well characterised model of olfactory nervous system injury, unilateral bulbectomy, to determine whether Grueneberg organ neurons degenerate after injury. We found that Grueneberg organ neurons degenerated in response to the axotomy, yet by 11 days post injury neurons and/or axons were detected again within the epithelium. Our results demonstrate that while Grueneberg organ neurons and glia have a distinct relationship in the epithelium, they have largely similar characteristics to that of the main olfactory neurons and glia.
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12
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Abstract
The olfactory system is one of a few areas in the nervous system which is capable of regeneration throughout the life. Olfactory sensory neurons reside in the nasal cavity are continuously replenished with new neurons arising from stem cells. Some factors such as aging, neurodegenerative diseases, head trauma, brain tumor extraction and infection cause olfactory dysfunction which significantly influences physical wellbeing, quality of life, mental health, nutritional status, memory processes, identifying danger and is associated with increased mortality. Therefore, finding a treatment to improve olfactory dysfunction is needed. Recent research efforts in the field have shown some very promising new approaches to treat olfactory dysfunction. This review explores the current studies that have addressed therapeutic approaches to improve olfactory neuron regeneration based on cell transplantation therapy, modulation of physiological olfactory dysfunction and drug treatments.
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Affiliation(s)
- Kate Beecher
- School of Biomedical Science, Queensland University of Technology; Institute of Health and Biomedical Innovation, Queensland University of Technology; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
| | - James A St John
- Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery; Menzies Health Institute Queensland, Griffith University, Brisbane, Queensland, Australia
| | - Fatemeh Chehrehasa
- School of Biomedical Science, Queensland University of Technology; Institute of Health and Biomedical Innovation, Queensland University of Technology; Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith Institute for Drug Discovery, Griffith University, Brisbane, Queensland, Australia
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13
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Imamura F, Hasegawa-Ishii S. Environmental Toxicants-Induced Immune Responses in the Olfactory Mucosa. Front Immunol 2016; 7:475. [PMID: 27867383 PMCID: PMC5095454 DOI: 10.3389/fimmu.2016.00475] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/19/2016] [Indexed: 01/02/2023] Open
Abstract
Olfactory sensory neurons (OSNs) are the receptor cells for the sense of smell. Although cell bodies are located in the olfactory mucosa (OM) of the nasal cavity, OSN axons directly project to the olfactory bulb (OB) that is a component of the central nervous system (CNS). Because of this direct and short connection from this peripheral tissue to the CNS, the olfactory system has attracted attention as a port-of-entry for environmental toxicants that may cause neurological dysfunction. Selected viruses can enter the OB via the OM and directly affect the CNS. On the other hand, environmental toxicants may induce inflammatory responses in the OM, including infiltration of immune cells and production of inflammatory cytokines. In addition, these inflammatory responses cause the loss of OSNs that are then replaced with newly generated OSNs that re-connect to the OB after inflammation has subsided. It is now known that immune cells and cytokines in the OM play important roles in both degeneration and regeneration of OSNs. Thus, the olfactory system is a unique neuroimmune interface where interaction between nervous and immune systems in the periphery significantly affects the structure, neuronal circuitry, and immunological status of the CNS. The mechanisms by which immune cells regulate OSN loss and the generation of new OSNs are, however, largely unknown. To help develop a better understanding of the mechanisms involved, we have provided a review of key research that has investigated how the immune response in the OM affects the pathophysiology of OSNs.
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Affiliation(s)
- Fumiaki Imamura
- Department of Pharmacology, Penn State College of Medicine , Hershey, PA , USA
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14
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Rela L, Piantanida AP, Bordey A, Greer CA. Voltage-dependent K+ currents contribute to heterogeneity of olfactory ensheathing cells. Glia 2015; 63:1646-59. [PMID: 25856239 DOI: 10.1002/glia.22834] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 03/24/2015] [Indexed: 02/03/2023]
Abstract
The olfactory nerve is permissive for axon growth throughout life. This has been attributed in part to the olfactory ensheathing glial cells that encompass the olfactory sensory neuron fascicles. Olfactory ensheathing cells (OECs) also promote axon growth in vitro and when transplanted in vivo to sites of injury. The mechanisms involved remain largely unidentified owing in part to the limited knowledge of the physiological properties of ensheathing cells. Glial cells rely for many functions on the properties of the potassium channels expressed; however, those expressed in ensheathing cells are unknown. Here we show that OECs express voltage-dependent potassium currents compatible with inward rectifier (Kir ) and delayed rectifier (KDR ) channels. Together with gap junction coupling, these contribute to the heterogeneity of membrane properties observed in OECs. The relevance of K(+) currents expressed by ensheathing cells is discussed in relation to plasticity of the olfactory nerve.
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Affiliation(s)
- Lorena Rela
- Departments of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut.,Systems Neuroscience Section, Department of Physiology and Biophysics, School of Medicine, University of Buenos Aires, Argentina.,Institute of Physiology and Biophysics Bernardo Houssay (IFIBIO Houssay-CONICET), Buenos Aires, Argentina
| | - Ana Paula Piantanida
- Systems Neuroscience Section, Department of Physiology and Biophysics, School of Medicine, University of Buenos Aires, Argentina.,Institute of Physiology and Biophysics Bernardo Houssay (IFIBIO Houssay-CONICET), Buenos Aires, Argentina
| | - Angelique Bordey
- Departments of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut.,Yale University School of Medicine, Departments of Cellular and Molecular Physiology, New Haven, Connecticut
| | - Charles A Greer
- Departments of Neurosurgery, Yale University School of Medicine, New Haven, Connecticut.,Yale University School of Medicine, Departments of Neurobiology, New Haven, Connecticut
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15
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Nazareth L, Tello Velasquez J, Lineburg KE, Chehrehasa F, St John JA, Ekberg JAK. Differing phagocytic capacities of accessory and main olfactory ensheathing cells and the implication for olfactory glia transplantation therapies. Mol Cell Neurosci 2015; 65:92-101. [PMID: 25752729 DOI: 10.1016/j.mcn.2015.03.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/06/2015] [Accepted: 03/04/2015] [Indexed: 01/01/2023] Open
Abstract
The rodent olfactory systems comprise the main olfactory system for the detection of odours and the accessory olfactory system which detects pheromones. In both systems, olfactory axon fascicles are ensheathed by olfactory glia, termed olfactory ensheathing cells (OECs), which are crucial for the growth and maintenance of the olfactory nerve. The growth-promoting and phagocytic characteristics of OECs make them potential candidates for neural repair therapies such as transplantation to repair the injured spinal cord. However, transplanting mixed populations of glia with unknown properties may lead to variations in outcomes for neural repair. As the phagocytic capacity of the accessory OECs has not yet been determined, we compared the phagocytic capacity of accessory and main OECs in vivo and in vitro. In normal healthy animals, the accessory OECs accumulated considerably less axon debris than main OECs in vivo. Analysis of freshly dissected OECs showed that accessory OECs contained 20% less fluorescent axon debris than main OECs. However, when assayed in vitro with exogenous axon debris added to the culture, the accessory OECs phagocytosed almost 20% more debris than main OECs. After surgical removal of one olfactory bulb which induced the degradation of main and accessory olfactory sensory axons, the accessory OECs responded by phagocytosing the axon debris. We conclude that while accessory OECs have the capacity to phagocytose axon debris, there are distinct differences in their phagocytic capacity compared to main OECs. These distinct differences may be of importance when preparing OECs for neural transplant repair therapies.
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Affiliation(s)
- Lynnmaria Nazareth
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4000 Queensland, Australia; Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111 Queensland, Australia
| | - Johana Tello Velasquez
- Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111 Queensland, Australia
| | - Katie E Lineburg
- QIMR-Berghofer Medical Research Institute, Herston, 4006 Queensland, Australia
| | - Fatemeh Chehrehasa
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4000 Queensland, Australia; Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111 Queensland, Australia
| | - James A St John
- Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111 Queensland, Australia.
| | - Jenny A K Ekberg
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4000 Queensland, Australia; Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111 Queensland, Australia.
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16
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Nazareth L, Lineburg KE, Chuah MI, Tello Velasquez J, Chehrehasa F, St John JA, Ekberg JAK. Olfactory ensheathing cells are the main phagocytic cells that remove axon debris during early development of the olfactory system. J Comp Neurol 2015; 523:479-94. [PMID: 25312022 DOI: 10.1002/cne.23694] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/09/2014] [Accepted: 10/10/2014] [Indexed: 11/07/2022]
Abstract
During development of the primary olfactory system, axon targeting is inaccurate and axons inappropriately project within the target layer or overproject into the deeper layers of the olfactory bulb. As a consequence there is considerable apoptosis of primary olfactory neurons during embryonic and postnatal development and axons of the degraded neurons need to be removed. Olfactory ensheathing cells (OECs) are the glia of the primary olfactory nerve and are known to phagocytose axon debris in the adult and postnatal animal. However, it is unclear when phagocytosis by OECs first commences. We investigated the onset of phagocytosis by OECs in the developing mouse olfactory system by utilizing two transgenic reporter lines: OMP-ZsGreen mice which express bright green fluorescent protein in primary olfactory neurons, and S100β-DsRed mice which express red fluorescent protein in OECs. In crosses of these mice, the fate of the degraded axon debris is easily visualized. We found evidence of axon degradation at embryonic day (E)13.5. Phagocytosis of the primary olfactory axon debris by OECs was first detected at E14.5. Phagocytosis of axon debris continued into the postnatal animal during the period when there was extensive mistargeting of olfactory axons. Macrophages were often present in close proximity to OECs but they contributed only a minor role to clearing the axon debris, even after widespread degeneration of olfactory neurons by unilateral bulbectomy and methimazole treatment. These results demonstrate that from early in embryonic development OECs are the primary phagocytic cells of the primary olfactory nerve.
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Affiliation(s)
- Lynnmaria Nazareth
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4000, Queensland, Australia; Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111, Queensland, Australia
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17
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Amaya DA, Wegner M, Stolt CC, Chehrehasa F, Ekberg JAK, St John JA. Radial glia phagocytose axonal debris from degenerating overextending axons in the developing olfactory bulb. J Comp Neurol 2015; 523:183-96. [PMID: 25116467 DOI: 10.1002/cne.23665] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 08/06/2014] [Accepted: 08/11/2014] [Indexed: 11/10/2022]
Abstract
Axon targeting during the development of the olfactory system is not always accurate, and numerous axons overextend past the target layer into the deeper layers of the olfactory bulb. To date, the fate of the mis-targeted axons has not been determined. We hypothesized that following overextension, the axons degenerate, and cells within the deeper layers of the olfactory bulb phagocytose the axonal debris. We utilized a line of transgenic mice that expresses ZsGreen fluorescent protein in primary olfactory axons. We found that overextending axons closely followed the filaments of radial glia present in the olfactory bulb during embryonic development. Following overextension into deeper layers of the olfactory bulb, axons degenerated and radial glia responded by phagocytosing the resulting debris. We used in vitro analysis to confirm that the radial glia had phagocytosed debris from olfactory axons. We also investigated whether the fate of overextending axons was altered when the development of the olfactory bulb was perturbed. In mice that lacked Sox10, a transcription factor essential for normal olfactory bulb development, we observed a disruption to the morphology and positioning of radial glia and an accumulation of olfactory axon debris within the bulb. Our results demonstrate that during early development of the olfactory system, radial glia play an important role in removing overextended axons from the deeper layers of the olfactory bulb.
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Affiliation(s)
- Daniel A Amaya
- Eskitis Institute for Drug Discovery, Griffith University, Nathan, Brisbane, Queensland, 4111, Australia
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18
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Burkholderia pseudomallei penetrates the brain via destruction of the olfactory and trigeminal nerves: implications for the pathogenesis of neurological melioidosis. mBio 2014; 5:e00025. [PMID: 24736221 PMCID: PMC3993850 DOI: 10.1128/mbio.00025-14] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Melioidosis is a potentially fatal disease that is endemic to tropical northern Australia and Southeast Asia, with a mortality rate of 14 to 50%. The bacterium Burkholderia pseudomallei is the causative agent which infects numerous parts of the human body, including the brain, which results in the neurological manifestation of melioidosis. The olfactory nerve constitutes a direct conduit from the nasal cavity into the brain, and we have previously reported that B. pseudomallei can colonize this nerve in mice. We have now investigated in detail the mechanism by which the bacteria penetrate the olfactory and trigeminal nerves within the nasal cavity and infect the brain. We found that the olfactory epithelium responded to intranasal B. pseudomallei infection by widespread crenellation followed by disintegration of the neuronal layer to expose the underlying basal layer, which the bacteria then colonized. With the loss of the neuronal cell bodies, olfactory axons also degenerated, and the bacteria then migrated through the now-open conduit of the olfactory nerves. Using immunohistochemistry, we demonstrated that B. pseudomallei migrated through the cribriform plate via the olfactory nerves to enter the outer layer of the olfactory bulb in the brain within 24 h. We also found that the bacteria colonized the thin respiratory epithelium in the nasal cavity and then rapidly migrated along the underlying trigeminal nerve to penetrate the cranial cavity. These results demonstrate that B. pseudomallei invasion of the nerves of the nasal cavity leads to direct infection of the brain and bypasses the blood-brain barrier. Melioidosis is a potentially fatal tropical disease that is endemic to northern Australia and Southeast Asia. It is caused by the bacterium Burkholderia pseudomallei, which can infect many organs of the body, including the brain, and results in neurological symptoms. The pathway by which the bacteria can penetrate the brain is unknown, and we have investigated the ability of the bacteria to migrate along nerves that innervate the nasal cavity and enter the frontal region of the brain by using a mouse model of infection. By generating a mutant strain of B. pseudomallei which is unable to survive in the blood, we show that the bacteria rapidly penetrate the cranial cavity using the olfactory (smell) nerve and the trigeminal (sensory) nerve that line the nasal cavity.
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19
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Stamegna JC, Girard SD, Veron A, Sicard G, Khrestchatisky M, Feron F, Roman FS. A unique method for the isolation of nasal olfactory stem cells in living rats. Stem Cell Res 2014; 12:673-9. [PMID: 24681208 DOI: 10.1016/j.scr.2014.02.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 01/23/2014] [Accepted: 02/27/2014] [Indexed: 12/23/2022] Open
Abstract
Stem cells are attractive tools to develop new therapeutic strategies for a variety of disorders. While ethical and technical issues, associated with embryonic, fetal and neural stem cells, limit the translation to clinical applications, the nasal stem cells identified in the human olfactory mucosa stand as a promising candidate for stem cell-based therapies. Located in the back of the nose, this multipotent stem cell type is readily accessible in humans, a feature that makes these cells highly suitable for the development of autologous cell-based therapies. However, preclinical studies based on autologous transplantation of rodent olfactory stem cells are impeded because of the narrow opening of the nasal cavity. In this study, we report the development of a unique method permitting to quickly and safely biopsy olfactory mucosa in rats. Using this newly developed technique, rat stem cells expressing the stem cell marker Nestin were successfully isolated without requiring the sacrifice of the donor animal. As an evidence of the self-renewal capacity of the isolated cells, several millions of rat cells were amplified from a single biopsy within four weeks. Using an olfactory discrimination test, we additionally showed that this novel biopsy method does not affect the sense of smell and the learning and memory abilities of the operated animals. This study describes for the first time a methodology allowing the derivation of rat nasal cells in a way that is suitable for studying the effects of autologous transplantation of any cell type present in the olfactory mucosa in a wide variety of rat models.
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Affiliation(s)
| | - Stéphane D Girard
- Aix Marseille Université, CNRS, NICN, UMR7259, 13344 Marseille, France
| | - Antoine Veron
- Aix Marseille Université, CNRS, NICN, UMR7259, 13344 Marseille, France
| | - Gilles Sicard
- Aix Marseille Université, CNRS, NICN, UMR7259, 13344 Marseille, France
| | | | - François Feron
- Aix Marseille Université, CNRS, NICN, UMR7259, 13344 Marseille, France; APHM, Centre d'Investigations Cliniques en Biothérapie CIC-BT 510, Marseille, France
| | - François S Roman
- Aix Marseille Université, CNRS, NICN, UMR7259, 13344 Marseille, France.
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20
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A novel method using intranasal delivery of EdU demonstrates that accessory olfactory ensheathing cells respond to injury by proliferation. Neurosci Lett 2014; 563:90-5. [PMID: 24486842 DOI: 10.1016/j.neulet.2014.01.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 01/14/2014] [Accepted: 01/21/2014] [Indexed: 02/05/2023]
Abstract
Olfactory ensheathing cells (OECs) play an important role in the continuous regeneration of the primary olfactory nervous system throughout life and for regeneration of olfactory neurons after injury. While it is known that several individual OEC subpopulations with distinct properties exist in different anatomical locations, it remains unclear how these different subpopulations respond to a major injury. We have examined the proliferation of OECs from one distinct location, the peripheral accessory olfactory nervous system, following large-scale injury (bulbectomy) in mice. We used crosses of two transgenic reporter mouse lines, S100ß-DsRed and OMP-ZsGreen, to visualise OECs, and main/accessory olfactory neurons, respectively. We surgically removed one olfactory bulb including the accessory olfactory bulb to induce degeneration, and found that accessory OECs in the nerve bundles that terminate in the accessory olfactory bulb responded by increased proliferation with a peak occurring 2 days after the injury. To label proliferating cells we used the thymidine analogue ethynyl deoxyuridine (EdU) using intranasal delivery instead of intraperitoneal injection. We compared and quantified the number of proliferating cells at different regions at one and four days after EdU labelling by the two different methods and found that intranasal delivery method was as effective as intraperitoneal injection. We demonstrated that accessory OECs actively respond to widespread degeneration of accessory olfactory axons by proliferating. These results have important implications for selecting the source of OECs for neural regeneration therapies and show that intranasal delivery of EdU is an efficient and reliable method for assessing proliferation of olfactory glia.
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21
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Forni PE, Wray S. Neural crest and olfactory system: new prospective. Mol Neurobiol 2012; 46:349-60. [PMID: 22773137 PMCID: PMC3586243 DOI: 10.1007/s12035-012-8286-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 05/27/2012] [Indexed: 02/07/2023]
Abstract
Sensory neurons in vertebrates are derived from two embryonic transient cell sources: neural crest (NC) and ectodermal placodes. The placodes are thickenings of ectodermal tissue that are responsible for the formation of cranial ganglia as well as complex sensory organs that include the lens, inner ear, and olfactory epithelium. The NC cells have been indicated to arise at the edges of the neural plate/dorsal neural tube, from both the neural plate and the epidermis in response to reciprocal interactions Moury and Jacobson (Dev Biol 141:243-253, 1990). NC cells migrate throughout the organism and give rise to a multitude of cell types that include melanocytes, cartilage and connective tissue of the head, components of the cranial nerves, the dorsal root ganglia, and Schwann cells. The embryonic definition of these two transient populations and their relative contribution to the formation of sensory organs has been investigated and debated for several decades (Basch and Bronner-Fraser, Adv Exp Med Biol 589:24-31, 2006; Basch et al., Nature 441:218-222, 2006) review (Baker and Bronner-Fraser, Dev Biol 232:1-61, 2001). Historically, all placodes have been described as exclusively derived from non-neural ectodermal progenitors. Recent genetic fate-mapping studies suggested a NC contribution to the olfactory placodes (OP) as well as the otic (auditory) placodes in rodents (Murdoch and Roskams, J Neurosci Off J Soc Neurosci 28:4271-4282, 2008; Murdoch et al., J Neurosci 30:9523-9532, 2010; Forni et al., J Neurosci Off J Soc Neurosci 31:6915-6927, 2011b; Freyer et al., Development 138:5403-5414, 2011; Katoh et al., Mol Brain 4:34, 2011). This review analyzes and discusses some recent developmental studies on the OP, placodal derivatives, and olfactory system.
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Affiliation(s)
- Paolo E. Forni
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Rm. 3A-1012, Bethesda, MD 20892-3703, USA
| | - Susan Wray
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Building 35, Rm. 3A-1012, Bethesda, MD 20892-3703, USA
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