1
|
Campbell WA, El-Hodiri HM, Torres D, Hawthorn EC, Kelly LE, Volkov L, Akanonu D, Fischer AJ. Chromatin access regulates the formation of Müller glia-derived progenitor cells in the retina. Glia 2023; 71:1729-1754. [PMID: 36971459 DOI: 10.1002/glia.24366] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 03/06/2023] [Accepted: 03/12/2023] [Indexed: 03/29/2023]
Abstract
Chromatin access and epigenetic control over gene expression play important roles in regulating developmental processes. However, little is known about how chromatin access and epigenetic gene silencing influence mature glial cells and retinal regeneration. Herein, we investigate the expression and functions of S-adenosylhomocysteine hydrolase (SAHH; AHCY) and histone methyltransferases (HMTs) during the formation of Müller glia (MG)-derived progenitor cells (MGPCs) in the chick and mouse retinas. In chick, AHCY, AHCYL1 and AHCYL2, and many different HMTs are dynamically expressed by MG and MGPCs in damaged retinas. Inhibition of SAHH reduced levels of H3K27me3 and potently blocks the formation of proliferating MGPCs. By using a combination of single cell RNA-seq and single cell ATAC-seq, we find significant changes in gene expression and chromatin access in MG with SAHH inhibition and NMDA-treatment; many of these genes are associated with glial and neuronal differentiation. A strong correlation across gene expression, chromatin access, and transcription factor motif access in MG was observed for transcription factors known to convey glial identity and promote retinal development. By comparison, in the mouse retina, inhibition of SAHH has no influence on the differentiation of neuron-like cells from Ascl1-overexpressing MG. We conclude that in the chick the activity of SAHH and HMTs are required for the reprogramming of MG into MGPCs by regulating chromatin access to transcription factors associated with glial differentiation and retinal development.
Collapse
Affiliation(s)
- Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Heithem M El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Diego Torres
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Evan C Hawthorn
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Lisa E Kelly
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Leo Volkov
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - David Akanonu
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
2
|
Campbell WA, Tangeman A, El-Hodiri HM, Hawthorn EC, Hathoot M, Blum S, Hoang T, Blackshaw S, Fischer AJ. Fatty acid-binding proteins and fatty acid synthase influence glial reactivity and promote the formation of Müller glia-derived progenitor cells in the chick retina. Development 2022; 149:274285. [PMID: 35132991 PMCID: PMC8959147 DOI: 10.1242/dev.200127] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 01/18/2022] [Indexed: 11/20/2022]
Abstract
A recent comparative transcriptomic study of Müller glia (MG) in vertebrate retinas revealed that fatty acid binding proteins (FABPs) are among the most highly expressed genes in chick ( Hoang et al., 2020). Here, we investigate how FABPs and fatty acid synthase (FASN) influence glial cells in the chick retina. During development, FABP7 is highly expressed by retinal progenitor cells and maturing MG, whereas FABP5 is upregulated in maturing MG. PMP2 (FABP8) is expressed by oligodendrocytes and FABP5 is expressed by non-astrocytic inner retinal glial cells, and both of these FABPs are upregulated by activated MG. In addition to suppressing the formation of Müller glia-derived progenitor cells (MGPCs), we find that FABP-inhibition suppresses the proliferation of microglia. FABP-inhibition induces distinct changes in single cell transcriptomic profiles, indicating transitions of MG from resting to reactive states and suppressed MGPC formation, with upregulation of gene modules for gliogenesis and decreases in neurogenesis. FASN-inhibition increases the proliferation of microglia and suppresses the formation of MGPCs. We conclude that fatty acid metabolism and cell signaling involving fatty acids are important in regulating the reactivity and dedifferentiation of MG, and the proliferation of microglia and MGPCs.
Collapse
Affiliation(s)
- Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Allen Tangeman
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Heithem M El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Evan C Hawthorn
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Maddie Hathoot
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Sydney Blum
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Thanh Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| |
Collapse
|
3
|
El-Hodiri HM, Campbell WA, Kelly LE, Hawthorn EC, Schwartz M, Jalligampala A, McCall MA, Meyer K, Fischer AJ. Nuclear Factor I in neurons, glia and during the formation of Müller glia-derived progenitor cells in avian, porcine and primate retinas. J Comp Neurol 2021; 530:1213-1230. [PMID: 34729776 DOI: 10.1002/cne.25270] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/21/2021] [Indexed: 11/10/2022]
Abstract
The regenerative potential of Müller glia (MG) is extraordinary in fish, poor in chick and terrible in mammals. In the chick model, MG readily reprogram into proliferating Müller glia-derived progenitor cells (MGPCs), but neuronal differentiation is very limited. The factors that suppress the neurogenic potential of MGPCs in the chick are slowly being revealed. Isoforms of Nuclear Factor I (NFI) are cell-intrinsic factors that limit neurogenic potential; these factors are required for the formation of MG in the developing mouse retina (Clark et al., 2019) and deletion of these factors reprograms MG into neuron-like cells in mature mouse retina (Hoang et al., 2020). Accordingly, we sought to characterize the patterns of expression NFIs in the developing, mature and damaged chick retina. In addition, we characterized patterns of expression of NFIs in the retinas of large mammals, pigs and monkeys. Using a combination of single cell RNA-sequencing (scRNA-seq) and immunolabeling we probed for patterns of expression. In embryonic chick, levels of NFIs are very low in early E5 (embryonic day 5) retinal progenitor cells (RPCs), up-regulated in E8 RPCs, further up-regulated in differentiating MG at E12 and E15. NFIs are maintained in mature resting MG, microglia and neurons. Levels of NFIs are reduced in activated MG in retinas treated with NMDA and/or insulin+FGF2, and further down-regulated in proliferating MGPCs. However, levels of NFIs in MGPCs were significantly higher than those seen in RPCs. Immunolabeling for NFIA and NFIB closely matched patterns of expression revealed in different types of retinal neurons and glia, consistent with findings from scRNA-seq. In addition, we find expression of NFIA and NFIB through progenitors in the circumferential marginal zone at the far periphery of the retina. We find similar patterns of expression for NFIs in scRNA-seq databases for pig and monkey retinas. Patterns of expression of NFIA and NFIB were validated with immunofluorescence in pig and monkey retinas wherein these factors were predominantly detected in MG and a few types of inner retinal neurons. In summary, NFIA and NFIB are prominently expressed in developing chick retina and by mature neurons and glia in the retinas of chicks, pigs and monkeys. Although levels of NFIs are decreased in chick, in MGPCs these levels remain higher than those seen in neurogenic RPCs. We propose that the neurogenic potential of MGPCs in the chick retina is suppressed by NFIs. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Heithem M El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH.,Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY
| | - Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Lisa E Kelly
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Evan C Hawthorn
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Maura Schwartz
- Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH
| | - Archana Jalligampala
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Maureen A McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Kathrin Meyer
- Center for Gene Therapy, Nationwide Children's Hospital, Columbus, OH
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| |
Collapse
|
4
|
Campbell WA, Fritsch-Kelleher A, Palazzo I, Hoang T, Blackshaw S, Fischer AJ. Midkine is neuroprotective and influences glial reactivity and the formation of Müller glia-derived progenitor cells in chick and mouse retinas. Glia 2021; 69:1515-1539. [PMID: 33569849 DOI: 10.1002/glia.23976] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 01/03/2023]
Abstract
Recent studies suggest midkine (MDK) is involved in the development and regeneration of the zebrafish retina. We investigate the expression patterns of MDK and related factors, roles in neuronal survival, and influence upon the formation of Müller glia-derived progenitor cells (MGPCs) in chick and mouse model systems. By using single-cell RNA-sequencing, we find that MDK and pleiotrophin (PTN), a MDK-related cytokine, are upregulated by Müller glia (MG) during later stages of development in chick. While PTN is downregulated, MDK is dramatically upregulated in mature MG after retinal damage or FGF2 and insulin treatment. By comparison, MDK and PTN are downregulated by MG in damaged mouse retinas. In both chick and mouse retinas, exogenous MDK induces expression of cFos and pS6 in MG. In the chick, MDK significantly decreases numbers dying neurons, reactive microglia, and proliferating MGPCs, whereas PTN has no effect. Inhibition of MDK-signaling with Na3 VO4 blocks neuroprotective effects with an increase in the number of dying cells and negates the pro-proliferative effects on MGPCs in damaged retinas. Inhibitors of PP2A and Pak1, which are associated with MDK-signaling through integrin β1, suppressed the formation of MGPCs in damaged chick retinas. In mice, MDK promotes a small but significant increase in proliferating MGPCs in damaged retinas and potently decreases the number of dying cells. We conclude that MDK expression is dynamically regulated in Müller glia during embryonic maturation, following retinal injury, and during reprogramming into MGPCs. MDK mediates glial activity, neuronal survival, and the re-programming of Müller glia into proliferating MGPCs.
Collapse
Affiliation(s)
- Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Amanda Fritsch-Kelleher
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Thanh Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
5
|
Yamagata M, Yan W, Sanes JR. A cell atlas of the chick retina based on single-cell transcriptomics. eLife 2021; 10:e63907. [PMID: 33393903 PMCID: PMC7837701 DOI: 10.7554/elife.63907] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/01/2021] [Indexed: 12/14/2022] Open
Abstract
Retinal structure and function have been studied in many vertebrate orders, but molecular characterization has been largely confined to mammals. We used single-cell RNA sequencing (scRNA-seq) to generate a cell atlas of the chick retina. We identified 136 cell types plus 14 positional or developmental intermediates distributed among the six classes conserved across vertebrates - photoreceptor, horizontal, bipolar, amacrine, retinal ganglion, and glial cells. To assess morphology of molecularly defined types, we adapted a method for CRISPR-based integration of reporters into selectively expressed genes. For Müller glia, we found that transcriptionally distinct cells were regionally localized along the anterior-posterior, dorsal-ventral, and central-peripheral retinal axes. We also identified immature photoreceptor, horizontal cell, and oligodendrocyte types that persist into late embryonic stages. Finally, we analyzed relationships among chick, mouse, and primate retinal cell classes and types. Our results provide a foundation for anatomical, physiological, evolutionary, and developmental studies of the avian visual system.
Collapse
Affiliation(s)
- Masahito Yamagata
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
| | - Wenjun Yan
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
| | - Joshua R Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard UniversityCambridgeUnited States
| |
Collapse
|
6
|
Palazzo I, Deistler K, Hoang TV, Blackshaw S, Fischer AJ. NF-κB signaling regulates the formation of proliferating Müller glia-derived progenitor cells in the avian retina. Development 2020; 147:dev.183418. [PMID: 32291273 DOI: 10.1242/dev.183418] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022]
Abstract
Retinal regeneration is robust in some cold-blooded vertebrates, but this process is ineffective in warm-blooded vertebrates. Understanding the mechanisms that suppress the reprogramming of Müller glia into neurogenic progenitors is key to harnessing the regenerative potential of the retina. Inflammation and reactive microglia are known to influence the formation of Müller glia-derived progenitor cells (MGPCs), but the mechanisms underlying this interaction are unknown. We used a chick in vivo model to investigate nuclear factor kappa B (NF-κB) signaling, a critical regulator of inflammation, during the reprogramming of Müller glia into proliferating progenitors. We find that components of the NF-κB pathway are dynamically regulated by Müller glia after neuronal damage or treatment with growth factors. Inhibition of NF-κB enhances, whereas activation suppresses, the formation of proliferating MGPCs. Following microglia ablation, the effects of NF-κB-agonists on MGPC-formation are reversed, suggesting that signals provided by reactive microglia influence how NF-κB impacts Müller glia reprogramming. We propose that NF-κB is an important signaling 'hub' that suppresses the reprogramming of Müller glia into proliferating MGPCs and this 'hub' coordinates signals provided by reactive microglia.
Collapse
Affiliation(s)
- Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Kyle Deistler
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| |
Collapse
|
7
|
Vancamp P, Bourgeois NMA, Houbrechts AM, Darras VM. Knockdown of the thyroid hormone transporter MCT8 in chicken retinal precursor cells hampers early retinal development and results in a shift towards more UV/blue cones at the expense of green/red cones. Exp Eye Res 2018; 178:135-147. [PMID: 30273578 DOI: 10.1016/j.exer.2018.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 09/21/2018] [Accepted: 09/27/2018] [Indexed: 12/19/2022]
Abstract
Thyroid hormones (THs) play a crucial role in coordinating brain development in vertebrates. They fine-tune processes like cell proliferation, migration, and differentiation mainly by regulating the transcriptional activity of many essential genes. Regulators of TH availability thereby define the cellular concentration of the bioactive 3,5,3'-triiodothyronine, which binds to nuclear TH receptors. One important regulator, the monocarboxylate transporter 8 (MCT8), facilitates cellular TH uptake and is known to be necessary for correct brain development, but data on its potential role during retinal development is lacking. The retinal cyto-architecture has been conserved throughout vertebrate evolution, and we used the chicken embryo to study the need for MCT8 during retinal development. Its external development allows easy manipulation, and MCT8 is abundantly expressed in the retina from early stages onwards. We induced MCT8 knockdown by electroporating a pRFP-MCT8-RNAi vector into the retinal precursor cells (RPCs) at embryonic day 4 (E4), and studied the consequences for early (E6) and late (E18) retinal development. The empty pRFP-RNAi vector was used as a control. RPC proliferation was reduced at E6. This resulted in cellular hypoplasia and a thinner retina at E18 where mainly photoreceptors and horizontal cells were lost, the two predominant cell types that are born around the stage of electroporation. At E6, differentiation into retinal ganglion cells and amacrine cells was delayed. However, since the proportion of a given cell type within the transfected cell population at E18 was similar in knockdown and controls, the partial loss of some cell types was most-likely due to reduced RPC proliferation and not impaired cell differentiation. Photoreceptors displayed delayed migration at first, but had successfully reached the outer nuclear layer at E18. However, they increasingly differentiated into short wavelength-sensitive cones at the expense of medium/long wavelength-sensitive cones, while the proportion of rods was unaltered. Improperly formed sublaminae in the inner plexiform layer additionally suggested defects in synaptogenesis. Altogether, our data echoes effects of hypothyroidism and the loss of some other regulators of TH availability in the developing zebrafish and rodent retina. Therefore, the expression of MCT8 in RPCs is crucial for adequate TH uptake during cell type-specific events in retinal development.
Collapse
Affiliation(s)
- Pieter Vancamp
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium
| | - Nele M A Bourgeois
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium
| | - Anne M Houbrechts
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium
| | - Veerle M Darras
- KU Leuven, Laboratory of Comparative Endocrinology, Department of Biology, B-3000, Leuven, Belgium.
| |
Collapse
|
8
|
Fernández-Flores F, García-Verdugo JM, Martín-Ibáñez R, Herranz C, Fondevila D, Canals JM, Arús C, Pumarola M. Characterization of the canine rostral ventricular-subventricular zone: Morphological, immunohistochemical, ultrastructural, and neurosphere assay studies. J Comp Neurol 2017; 526:721-741. [DOI: 10.1002/cne.24365] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 10/09/2017] [Accepted: 11/16/2017] [Indexed: 02/01/2023]
Affiliation(s)
- Francisco Fernández-Flores
- Veterinary Faculty, Department of Animal Medicine and Surgery; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN); Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
| | - José Manuel García-Verdugo
- Laboratorio de Neurobiologia comparada, Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, CIBERNED; Valencia Spain
| | - Raquel Martín-Ibáñez
- Stem Cells and Regenerative Medicine Laboratory; Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, Department of Biomedicine; University of Barcelona; Barcelona Spain
- Neuroscience Institute, University of Barcelona; Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED); Valencia Spain
| | - Cristina Herranz
- Stem Cells and Regenerative Medicine Laboratory; Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, Department of Biomedicine; University of Barcelona; Barcelona Spain
- Neuroscience Institute, University of Barcelona; Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED); Valencia Spain
| | - Dolors Fondevila
- Veterinary Faculty, Department of Animal Medicine and Surgery; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
| | - Josep María Canals
- Stem Cells and Regenerative Medicine Laboratory; Production and Validation Center of Advanced Therapies (Creatio), Faculty of Medicine and Health Science, Department of Biomedicine; University of Barcelona; Barcelona Spain
- Neuroscience Institute, University of Barcelona; Barcelona Spain
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Barcelona Spain
- Networked Biomedical Research Centre for Neurodegenerative Disorders (CIBERNED); Valencia Spain
| | - Carles Arús
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN); Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
- Departament de Bioquímica i Biologia Molecular; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
| | - Martí Pumarola
- Veterinary Faculty, Department of Animal Medicine and Surgery; Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN); Universitat Autònoma de Barcelona; Bellaterra (Cerdanyola del Vallès) Barcelona Spain
| |
Collapse
|
9
|
Todd L, Suarez L, Quinn C, Fischer AJ. Retinoic Acid-Signaling Regulates the Proliferative and Neurogenic Capacity of Müller Glia-Derived Progenitor Cells in the Avian Retina. Stem Cells 2017; 36:392-405. [PMID: 29193451 DOI: 10.1002/stem.2742] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/16/2017] [Accepted: 11/03/2017] [Indexed: 12/26/2022]
Abstract
In the retina, Müller glia have the potential to become progenitor cells with the ability to proliferate and regenerate neurons. However, the ability of Müller glia-derived progenitor cells (MGPCs) to proliferate and produce neurons is limited in higher vertebrates. Using the chick model system, we investigate how retinoic acid (RA)-signaling influences the proliferation and the formation of MGPCs. We observed an upregulation of cellular RA binding proteins (CRABP) in the Müller glia of damaged retinas where the formation of MGPCs is known to occur. Activation of RA-signaling was stimulated, whereas inhibition suppressed the proliferation of MGPCs in damaged retinas and in fibroblast growth factor 2-treated undamaged retinas. Furthermore, inhibition of RA-degradation stimulated the proliferation of MGPCs. Levels of Pax6, Klf4, and cFos were upregulated in MGPCs by RA agonists and downregulated in MGPCs by RA antagonists. Activation of RA-signaling following MGPC proliferation increased the percentage of progeny that differentiated as neurons. Similarly, the combination of RA and insulin-like growth factor 1 (IGF1) significantly increased neurogenesis from retinal progenitors in the circumferential marginal zone (CMZ). In summary, RA-signaling stimulates the formation of proliferating MGPCs and enhances the neurogenic potential of MGPCs and stem cells in the CMZ. Stem Cells 2018;36:392-405.
Collapse
Affiliation(s)
- Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Lilianna Suarez
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Colin Quinn
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| |
Collapse
|
10
|
Wisely CE, Sayed JA, Tamez H, Zelinka C, Abdel-Rahman MH, Fischer AJ, Cebulla CM. The chick eye in vision research: An excellent model for the study of ocular disease. Prog Retin Eye Res 2017; 61:72-97. [PMID: 28668352 PMCID: PMC5653414 DOI: 10.1016/j.preteyeres.2017.06.004] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/24/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023]
Abstract
The domestic chicken, Gallus gallus, serves as an excellent model for the study of a wide range of ocular diseases and conditions. The purpose of this manuscript is to outline some anatomic, physiologic, and genetic features of this organism as a robust animal model for vision research, particularly for modeling human retinal disease. Advantages include a sequenced genome, a large eye, relative ease of handling and maintenance, and ready availability. Relevant similarities and differences to humans are highlighted for ocular structures as well as for general physiologic processes. Current research applications for various ocular diseases and conditions, including ocular imaging with spectral domain optical coherence tomography, are discussed. Several genetic and non-genetic ocular disease models are outlined, including for pathologic myopia, keratoconus, glaucoma, retinal detachment, retinal degeneration, ocular albinism, and ocular tumors. Finally, the use of stem cell technology to study the repair of damaged tissues in the chick eye is discussed. Overall, the chick model provides opportunities for high-throughput translational studies to more effectively prevent or treat blinding ocular diseases.
Collapse
Affiliation(s)
- C Ellis Wisely
- Havener Eye Institute, Department of Ophthalmology and Visual Science, The Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
| | - Javed A Sayed
- Havener Eye Institute, Department of Ophthalmology and Visual Science, The Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
| | - Heather Tamez
- Havener Eye Institute, Department of Ophthalmology and Visual Science, The Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
| | - Chris Zelinka
- Department of Neuroscience, The Ohio State University Wexner Medical Center, 333 West 10th Avenue, Columbus, OH 43210, USA
| | - Mohamed H Abdel-Rahman
- Havener Eye Institute, Department of Ophthalmology and Visual Science, The Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
| | - Andy J Fischer
- Department of Neuroscience, The Ohio State University Wexner Medical Center, 333 West 10th Avenue, Columbus, OH 43210, USA.
| | - Colleen M Cebulla
- Havener Eye Institute, Department of Ophthalmology and Visual Science, The Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA.
| |
Collapse
|
11
|
Todd L, Palazzo I, Squires N, Mendonca N, Fischer AJ. BMP- and TGFβ-signaling regulate the formation of Müller glia-derived progenitor cells in the avian retina. Glia 2017; 65:1640-1655. [PMID: 28703293 DOI: 10.1002/glia.23185] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 05/24/2017] [Accepted: 06/13/2017] [Indexed: 01/20/2023]
Abstract
Müller glia-derived progenitor cells (MGPCs) have the capability to regenerate neurons in the retinas of different vertebrate orders. The formation of MGPCs is regulated by a network of cell-signaling pathways. The purpose of this study was to investigate how BMP/Smad1/5/8- and TGFβ/Smad2/3-signaling are coordinated to influence the formation of MGPCs in the chick model system. We find that pSmad1/5/8 is selectively up-regulated in the nuclei of Müller glia following treatment with BMP4, FGF2, or NMDA-induced damage, and this up-regulation is blocked by a dorsomorphin analogue DMH1. By comparison, Smad2/3 is found in the nuclei of Müller glia in untreated retinas, and becomes localized to the cytoplasm following NMDA- or FGF2-treatment. These findings suggest a decrease in TGFβ- and increase in BMP-signaling when MGPCs are known to form. In both NMDA-damaged and FGF2-treated retinas, inhibition of BMP-signaling suppressed the proliferation of MGPCs, whereas inhibition of TGFβ-signaling stimulated the proliferation of MGPCs. Consistent with these findings, TGFβ2 suppressed the formation of MGPCs in NMDA-damaged retinas. Our findings indicate that BMP/TGFβ/Smad-signaling is recruited into the network of signaling pathways that controls the formation of proliferating MGPCs. We conclude that signaling through BMP4/Smad1/5/8 promotes the formation of MGPCs, whereas signaling through TGFβ/Smad2/3 suppresses the formation of MGPCs.
Collapse
Affiliation(s)
- Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, Ohio, 43210
| | - Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, Ohio, 43210
| | - Natalie Squires
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, Ohio, 43210
| | - Ninoshka Mendonca
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, Ohio, 43210
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, Ohio, 43210
| |
Collapse
|
12
|
Todd L, Squires N, Suarez L, Fischer AJ. Jak/Stat signaling regulates the proliferation and neurogenic potential of Müller glia-derived progenitor cells in the avian retina. Sci Rep 2016; 6:35703. [PMID: 27759082 PMCID: PMC5069623 DOI: 10.1038/srep35703] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 10/04/2016] [Indexed: 12/26/2022] Open
Abstract
Müller glia are capable of de-differentiating and proliferating to become Müller glia-derived progenitor cells (MGPCs) with the ability to regenerate retinal neurons. One of the cell-signaling pathways that drives the reprogramming of Müller glia into MGPCs in the zebrafish retina is the Jak/Stat-pathway. However, nothing is known about the influence of Jak/Stat-signaling during the formation of MGPCs in the retinas of warm-blooded vertebrates. Accordingly, we examined whether Jak/Stat-signaling influences the formation of MGPCs and differentiation of progeny in the avian retina. We found that Jak/Stat-signaling is activated in Müller glia in response to NMDA-induced retinal damage or by CNTF or FGF2 in the absence of retinal damage. Inhibition of gp130, Jak2, or Stat3 suppressed the formation of proliferating MGPCs in NMDA-damaged and FGF2-treated retinas. Additionally, CNTF combined with FGF2 enhanced the formation of proliferating MGPCs in the absence of retinal damage. In contrast to the zebrafish model, where activation of gp130/Jak/Stat is sufficient to drive neural regeneration from MGPCs, signaling through gp130 inhibits the neurogenic potential of MGPCs and promotes glial differentiation. We conclude that gp130/Jak/Stat-signaling plays an important role in the network of pathways that drives the formation of proliferating MGPCs; however, this pathway inhibits the neural differentiation of the progeny.
Collapse
Affiliation(s)
- Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
| | - Natalie Squires
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
| | - Lilianna Suarez
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
| |
Collapse
|
13
|
Shaw PX, Fang J, Sang A, Wang Y, Kapiloff MS, Goldberg JL. Soluble Adenylyl Cyclase Is Required for Retinal Ganglion Cell and Photoreceptor Differentiation. Invest Ophthalmol Vis Sci 2016; 57:5083-5092. [PMID: 27679853 PMCID: PMC5053116 DOI: 10.1167/iovs.16-19465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Purpose We have previously demonstrated that soluble adenylyl cyclase (sAC) is necessary for retinal ganglion cell (RGC) survival and axon growth. Here, we further investigate the role of sAC in neuronal differentiation during retinal development. Methods Chx10 or Math5 promoter-driven Cre-Lox recombination were used to conditionally delete sAC from early and intermediate retinal progenitor cells during retinal development. We examined cell type–specific markers expressed by retinal cells to estimate their relative numbers and characterize retinal laminar morphology by immunofluorescence in adult and newborn mice. Results Retinal ganglion cell and amacrine cell markers were significantly lower in the retinas of adult Math5cre/sACfl/fl and Chx10cre/sACfl/fl mice than in those of wild-type controls. The effect on RGC development was detectable as early as postnatal day 1 and deleting sAC in either Math5- or Chx10-expressing retinal progenitor cells also reduced nerve fiber layer thickness into adulthood. The thickness of the photoreceptor layer was slightly but statistically significantly decreased in both the newborn Chx10cre/sACfl/fl and Math5cre/sACfl/fl mice, but this reduction and abnormal morphology persisted in the adults in only the Chx10cre/sACfl/fl mice. Conclusions sAC plays an important role in the early retinal development of RGCs as well as in the development of amacrine cells and to a lesser degree photoreceptors.
Collapse
Affiliation(s)
- Peter X Shaw
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Jiahua Fang
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States 2Department of Ophthalmology, First Hospital of Changsha, Changsha, Hunan Province, China
| | - Alan Sang
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Yan Wang
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Michael S Kapiloff
- Interdisciplinary Stem Cell Institute, Departments of Pediatrics and Medicine, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Jeffrey L Goldberg
- Department of Ophthalmology, University of California San Diego, La Jolla, California, United States 4Byers Eye Institute, Stanford University, Palo Alto, California, United States
| |
Collapse
|
14
|
Roth S, Dreixler JC, Mathew B, Balyasnikova I, Mann JR, Boddapati V, Xue L, Lesniak MS. Hypoxic-Preconditioned Bone Marrow Stem Cell Medium Significantly Improves Outcome After Retinal Ischemia in Rats. Invest Ophthalmol Vis Sci 2016; 57:3522-32. [PMID: 27367588 PMCID: PMC4961056 DOI: 10.1167/iovs.15-17381] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 04/28/2016] [Indexed: 12/20/2022] Open
Abstract
PURPOSE We have previously demonstrated the protective effect of bone marrow stem cell (BMSC)-conditioned medium in retinal ischemic injury. We hypothesized here that hypoxic preconditioning of stem cells significantly enhances the neuroprotective effect of the conditioned medium and thereby augments the protective effect in ischemic retina. METHODS Rats were subjected to retinal ischemia by increasing intraocular pressure to 130 to 135 mm Hg for 55 minutes. Hypoxic-preconditioned, hypoxic unconditioned, or normoxic medium was injected into the vitreous 24 hours after ischemia ended. Recovery was assessed 7 days after injections by comparing electroretinography measurements, histologic examination, and apoptosis (TUNEL, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay). To compare proteins secreted into the medium in the groups and the effect of hypoxic exposure, we used rat cytokine arrays. RESULTS Eyes injected with hypoxic BMSC-conditioned medium 24 hours after ischemia demonstrated significantly enhanced return of retinal function, decreased retinal ganglion cell layer loss, and attenuated apoptosis compared to those administered normoxic or hypoxic unconditioned medium. Hypoxic-preconditioned medium had 21 significantly increased protein levels compared to normoxic medium. CONCLUSIONS The medium from hypoxic-preconditioned BMSCs robustly restored retinal function and prevented cell loss after ischemia when injected 24 hours after ischemia. The protective effect was even more pronounced than in our previous studies of normoxic conditioned medium. Prosurvival signals triggered by the secretome may play a role in this neuroprotective effect.
Collapse
Affiliation(s)
- Steven Roth
- Department of Anesthesiology, University of Illinois, Illinois, United States
- Department of Anesthesia and Critical Care, University of Chicago, Illinois, United States
| | - John C. Dreixler
- Department of Anesthesia and Critical Care, University of Chicago, Illinois, United States
| | - Biji Mathew
- Department of Anesthesiology, University of Illinois, Illinois, United States
| | - Irina Balyasnikova
- Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
- Surgery, University of Chicago Medicine, University of Chicago, Illinois, United States
| | - Jacob R. Mann
- Department of Anesthesia and Critical Care, University of Chicago, Illinois, United States
| | - Venkat Boddapati
- Department of Anesthesia and Critical Care, University of Chicago, Illinois, United States
| | - Lai Xue
- Surgery, University of Chicago Medicine, University of Chicago, Illinois, United States
| | - Maciej S. Lesniak
- Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
- Surgery, University of Chicago Medicine, University of Chicago, Illinois, United States
| |
Collapse
|
15
|
Zelinka CP, Volkov L, Goodman ZA, Todd L, Palazzo I, Bishop WA, Fischer AJ. mTor signaling is required for the formation of proliferating Müller glia-derived progenitor cells in the chick retina. Development 2016; 143:1859-73. [PMID: 27068108 PMCID: PMC4920162 DOI: 10.1242/dev.133215] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 04/04/2016] [Indexed: 12/29/2022]
Abstract
We investigate the roles of mTor signaling in the formation of Müller glia-derived progenitor cells (MGPCs) in the chick retina. During embryonic development, pS6 (a readout of active mTor signaling) is present in early-stage retinal progenitors, differentiating amacrine and ganglion cells, and late-stage progenitors or maturing Müller glia. By contrast, pS6 is present at low levels in a few scattered cell types in mature, healthy retina. Following retinal damage, in which MGPCs are known to form, mTor signaling is rapidly activated in Müller glia. Inhibition of mTor in damaged retinas prevented the accumulation of pS6 in Müller glia and reduced numbers of proliferating MGPCs. Inhibition of mTor had no effect on MAPK signaling or on upregulation of the stem cell factor Klf4, whereas Pax6 upregulation was significantly reduced. Inhibition of mTor potently blocked the MGPC-promoting effects of Hedgehog, Wnt and glucocorticoid signaling in damaged retinas. In the absence of retinal damage, insulin, IGF1 and FGF2 induced pS6 in Müller glia, and this was blocked by mTor inhibitor. In FGF2-treated retinas, in which MGPCs are known to form, inhibition of mTor blocked the accumulation of pS6, the upregulation of Pax6 and the formation of proliferating MGPCs. We conclude that mTor signaling is required, but not sufficient, to stimulate Müller glia to give rise to proliferating progenitors, and the network of signaling pathways that drive the formation of MGPCs requires activation of mTor.
Collapse
Affiliation(s)
- Christopher P Zelinka
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| | - Leo Volkov
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| | - Zachary A Goodman
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| | - Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| | - Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| | - William A Bishop
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Avenue, Columbus, OH 43210-1239, USA
| |
Collapse
|
16
|
Gallina D, Palazzo I, Steffenson L, Todd L, Fischer AJ. Wnt/β-catenin-signaling and the formation of Müller glia-derived progenitors in the chick retina. Dev Neurobiol 2015; 76:983-1002. [PMID: 26663639 DOI: 10.1002/dneu.22370] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 11/25/2015] [Accepted: 12/02/2015] [Indexed: 11/12/2022]
Abstract
Müller glia can be stimulated to de-differentiate, proliferate, and form Müller glia-derived progenitor cells (MGPCs) that are capable of producing retinal neurons. The signaling pathways that influence the de-differentiation of mature Müller glia and proliferation of MGPCs may include the Wnt-pathway. The purpose of this study was to investigate how Wnt-signaling influences the formation of MGPCs in the chick retina in vivo. In NMDA-damaged retinas where MGPCs are known to form, we find dynamic changes in retinal levels of potential readouts of Wnt-signaling, including dkk1, dkk3, axin2, c-myc, tcf-1, and cd44. We find accumulations of nuclear β-catenin in MGPCs that peaks at 3 days and rapidly declines by 5 days after NMDA-treatment. Inhibition of Wnt-signaling with XAV939 in damaged retinas suppressed the formation of MGPCs, increased expression of ascl1a and decreased hes5, but had no effect upon the differentiation of progeny produced by MGPCs. Activation of Wnt-signaling, with GSK3β-inhibitors, in the absence of retinal damage, failed to stimulate the formation of MGPCs, whereas activation of Wnt-signaling in damaged retinas stimulated the formation of MGPCs. In the absence of retinal damage, FGF2/MAPK-signaling stimulated the formation of MGPCs by activating a signaling network that includes Wnt/β-catenin. In FGF2-treated retinas, inhibition of Wnt-signaling reduced numbers of proliferating MGPCs, whereas activation of Wnt-signaling failed to influence the formation of proliferating MGPCs. Our findings indicate that Wnt-signaling is part of a network initiated by FGF2/MAPK or retinal damage, and activation of canonical Wnt-signaling is required for the formation of proliferating MGPCs. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 983-1002, 2016.
Collapse
Affiliation(s)
- Donika Gallina
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Isabella Palazzo
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Lillia Steffenson
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Levi Todd
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, Columbus, Ohio
| |
Collapse
|
17
|
Todd L, Suarez L, Squires N, Zelinka CP, Gribbins K, Fischer AJ. Comparative analysis of glucagonergic cells, glia, and the circumferential marginal zone in the reptilian retina. J Comp Neurol 2015; 524:74-89. [PMID: 26053997 DOI: 10.1002/cne.23823] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/19/2015] [Accepted: 05/26/2015] [Indexed: 12/14/2022]
Abstract
Retinal progenitors in the circumferential marginal zone (CMZ) and Müller glia-derived progenitors have been well described for the eyes of fish, amphibians, and birds. However, there is no information regarding a CMZ and the nature of retinal glia in species phylogenetically bridging amphibians and birds. The purpose of this study was to examine the retinal glia and investigate whether a CMZ is present in the eyes of reptilian species. We used immunohistochemical analyses to study retinal glia, neurons that could influence CMZ progenitors, the retinal margin, and the nonpigmented epithelium of ciliary body of garter snakes, queen snakes, anole lizards, snapping turtles, and painted turtles. We compare our observations on reptile eyes to the CMZ and glia of fish, amphibians, and birds. In all species, Sox9, Pax6, and the glucocorticoid receptor are expressed by Müller glia and cells at the retinal margin. However, proliferating cells were found only in the CMZ of turtles and not in the eyes of anoles and snakes. Similar to eyes of chickens, the retinal margin in turtles contains accumulations of GLP1/glucagonergic neurites. We find that filamentous proteins, vimentin and GFAP, are expressed by Müller glia, but have different patterns of subcellular localization in the different species of reptiles. We provide evidence that the reptile retina may contain nonastrocytic inner retinal glial cells, similar to those described in the avian retina. We conclude that the retinal glia, glucagonergic neurons, and CMZ of turtles appear to be most similar to those of fish, amphibians, and birds.
Collapse
Affiliation(s)
- Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, 43210
| | - Lilianna Suarez
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, 43210
| | - Natalie Squires
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, 43210
| | | | - Kevin Gribbins
- Department of Biology, University of Indianapolis, Indianapolis, IN, 47201
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, 43210
| |
Collapse
|
18
|
|
19
|
Oligodendrocyte precursor cell-intrinsic effect of Rheb1 controls differentiation and mediates mTORC1-dependent myelination in brain. J Neurosci 2015; 34:15764-78. [PMID: 25411504 DOI: 10.1523/jneurosci.2267-14.2014] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Rheb1 is an immediate early gene that functions to activate mammalian target of rapamycin (mTor) selectively in complex 1 (mTORC1). We have demonstrated previously that Rheb1 is essential for myelination in the CNS using a Nestin-Cre driver line that deletes Rheb1 in all neural cell lineages, and recent studies using oligodendrocyte-specific CNP-Cre have suggested a preferential role for mTORC1 is myelination in the spinal cord. Here, we examine the role of Rheb1/mTORC1 in mouse oligodendrocyte lineage using separate Cre drivers for oligodendrocyte progenitor cells (OPCs) including Olig1-Cre and Olig2-Cre as well as differentiated and mature oligodendrocytes including CNP-Cre and Tmem10-Cre. Deletion of Rheb1 in OPCs impairs their differentiation to mature oligodendrocytes. This is accompanied by reduced OPC cell-cycle exit suggesting a requirement for Rheb1 in OPC differentiation. The effect of Rheb1 on OPC differentiation is mediated by mTor since Olig1-Cre deletion of mTor phenocopies Olig1-Cre Rheb1 deletion. Deletion of Rheb1 in mature oligodendrocytes, in contrast, does not disrupt developmental myelination or myelin maintenance. Loss of Rheb1 in OPCs or neural progenitors does not affect astrocyte formation in gray and white matter, as indicated by the pan-astrocyte marker Aldh1L1. We conclude that OPC-intrinsic mTORC1 activity mediated by Rheb1 is critical for differentiation of OPCs to mature oligodendrocytes, but that mature oligodendrocytes do not require Rheb1 to make myelin or maintain it in the adult brain. These studies reveal mechanisms that may be relevant for both developmental myelination and impaired remyelination in myelin disease.
Collapse
|
20
|
Tao C, Zhang X. Development of astrocytes in the vertebrate eye. Dev Dyn 2014; 243:1501-10. [PMID: 25236977 DOI: 10.1002/dvdy.24190] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 08/22/2014] [Accepted: 09/12/2014] [Indexed: 02/04/2023] Open
Abstract
Astrocytes represent the earliest glial population in the embryonic optic nerve, contributing critically to retinal angiogenesis and formation of brain-retinal-barrier. Despite of many developmental and clinical implications of astrocytes, answers to some of the most fundamental questions of this unique type of glial cells remain elusive. This review provides an overview of the current knowledge about the origination, proliferation, and differentiation of astrocytes, their journey from the optic nerve toward the neuroretina, and their involvement in physiological and pathological development of the visual system.
Collapse
Affiliation(s)
- Chenqi Tao
- Stark Neuroscience Institute, Indiana University School of Medicine, Indianapolis, Indiana; Departments of Ophthalmology, Pathology, and Cell Biology, Columbia University, New York, New York
| | | |
Collapse
|
21
|
Dharmarajan S, Gurel Z, Wang S, Sorenson CM, Sheibani N, Belecky-Adams TL. Bone morphogenetic protein 7 regulates reactive gliosis in retinal astrocytes and Müller glia. Mol Vis 2014; 20:1085-108. [PMID: 25253985 PMCID: PMC4119236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 07/29/2014] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The focus of this study was to determine whether bone morphogenetic proteins (BMPs) trigger reactive gliosis in retinal astrocytes and/or Müller glial cells. METHODS Retinal astrocytes and the Müller glial cell line MIO-M1 were treated with vehicle, BMP7, or BMP4. Samples from the treated cells were analyzed for changes in gliosis markers using reverse transcriptase - quantitative PCR (RT-qPCR) and western blotting. To determine potential similarities and differences in gliosis states, control and BMP-treated cells were compared to cells treated with sodium peroxynitrite (a strong oxidizing agent that will bring about some aspects of gliosis). Last, mature mice were microinjected intravitreally with BMP7 and analyzed for changes in gliosis markers using RT-qPCR, western blotting, and immunohistochemistry. RESULTS Treatment of retinal astrocyte cells and Müller glial cells with BMP7 regulated various reactive gliosis markers. When compared to the response of cells treated with sodium peroxynitrite, the profiles of gliosis markers regulated due to exposure to BMP7 were similar. However, as expected, the profiles including the oxidative agent and growth factor were not identical. Treatment of cells with BMP4, however, showed an attenuated response in comparison to peroxynitrite and BMP7 treatment. Injection of BMP7 into the mouse retina also triggered a reactive gliosis response 7 days after injection. CONCLUSIONS BMP7 induced changes in levels of mRNA and protein markers typically associated with reactive gliosis in retinal astrocytes and Müller glial cells, including glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), a subset of chondroitin sulfate proteoglycans (CSPGs), matrix metalloproteinases (MMPs), and other molecules.
Collapse
Affiliation(s)
- Subramanian Dharmarajan
- Department of Biology, Indiana University-Purdue University Indianapolis,, Indianapolis, IN,Center for Regenerative Biology and Medicine, Indiana University- Purdue University Indianapolis, Indianapolis, IN
| | - Zafer Gurel
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Shoujian Wang
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI
| | - Christine M. Sorenson
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI,McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public health, Madison, WI
| | - Nader Sheibani
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI,McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public health, Madison, WI
| | - Teri L. Belecky-Adams
- Department of Biology, Indiana University-Purdue University Indianapolis,, Indianapolis, IN,Center for Regenerative Biology and Medicine, Indiana University- Purdue University Indianapolis, Indianapolis, IN
| |
Collapse
|
22
|
Fischer AJ, Zelinka C, Gallina D, Scott MA, Todd L. Reactive microglia and macrophage facilitate the formation of Müller glia-derived retinal progenitors. Glia 2014; 62:1608-28. [PMID: 24916856 DOI: 10.1002/glia.22703] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/11/2014] [Accepted: 05/16/2014] [Indexed: 12/12/2022]
Abstract
In retinas where Müller glia have been stimulated to become progenitor cells, reactive microglia are always present. Thus, we investigated how the activation or ablation of microglia/macrophage influences the formation of Müller glia-derived progenitor cells (MGPCs) in the retina in vivo. Intraocular injections of the Interleukin-6 (IL6) stimulated the reactivity of microglia/macrophage, whereas other types of retinal glia appear largely unaffected. In acutely damaged retinas where all of the retinal microglia/macrophage were ablated, the formation of proliferating MGPCs was greatly diminished. With the microglia ablated in damaged retinas, levels of Notch and related genes were unchanged or increased, whereas levels of ascl1a, TNFα, IL1β, complement component 3 (C3) and C3a receptor were significantly reduced. In the absence of retinal damage, the combination of insulin and Fibroblast growth factor 2 (FGF2) failed to stimulate the formation of MGPCs when the microglia/macrophage were ablated. In addition, intraocular injections of IL6 and FGF2 stimulated the formation of MGPCs in the absence of retinal damage, and this generation of MGPCs was blocked when the microglia/macrophage were absent. We conclude that the activation of microglia and/or infiltrating macrophage contributes to the formation of proliferating MGPCs, and these effects may be mediated by components of the complement system and inflammatory cytokines.
Collapse
Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio
| | | | | | | | | |
Collapse
|
23
|
Gallina D, Todd L, Fischer AJ. A comparative analysis of Müller glia-mediated regeneration in the vertebrate retina. Exp Eye Res 2013; 123:121-30. [PMID: 23851023 DOI: 10.1016/j.exer.2013.06.019] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/13/2013] [Accepted: 06/18/2013] [Indexed: 10/26/2022]
Abstract
This article reviews the current state of knowledge regarding the potential of Müller glia to become neuronal progenitor cells in the avian retina. We compare and contrast the remarkable proliferative and neurogenic capacity of Müller glia in the fish retina to the limited capacity of Müller glia in avian and rodent retinas. We summarize recent findings regarding the secreted factors, signaling pathways and cell intrinsic factors that have been implicated in the formation of Müller glia-derived progenitors. We discuss several key similarities and differences between the fish, rodent and chick model systems, highlighting several of the key transcription factors and signaling pathways that regulate the formation of Müller glia-derived progenitors.
Collapse
Affiliation(s)
- Donika Gallina
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210-1239, USA
| | - Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210-1239, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210-1239, USA.
| |
Collapse
|
24
|
Zelinka CP, Scott MA, Volkov L, Fischer AJ. The reactivity, distribution and abundance of Non-astrocytic Inner Retinal Glial (NIRG) cells are regulated by microglia, acute damage, and IGF1. PLoS One 2012; 7:e44477. [PMID: 22973454 PMCID: PMC3433418 DOI: 10.1371/journal.pone.0044477] [Citation(s) in RCA: 36] [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: 05/23/2012] [Accepted: 08/07/2012] [Indexed: 12/05/2022] Open
Abstract
Recent studies have described a novel type of glial cell that is scattered across the inner layers of the avian retina and possibly the retinas of primates. These cells have been termed Non-astrocytic Inner Retinal Glial (NIRG) cells. These cells are stimulated by insulin-like growth factor 1 (IGF1) to proliferate, migrate distally into the retina, and become reactive. These changes in glial activity correlate with increased susceptibility of retinal neurons and Müller glia to excitotoxic damage. The purpose of this study was to further study the NIRG cells in retinas treated with IGF1 or acute damage. In response to IGF1, the reactivity, proliferation and migration of NIRG cells persists through 3 days after treatment. At 7 days after treatment, the numbers and distribution of NIRG cells returns to normal, suggesting that homeostatic mechanisms are in place within the retina to maintain the numbers and distribution of these glial cells. By comparison, IGF1-induced microglial reactivity persists for at least 7 days after treatment. In damaged retinas, we find a transient accumulation of NIRG cells, which parallels the accumulation of reactive microglia, suggesting that the reactivity of NIRG cells and microglia are linked. When the microglia are selectively ablated by the combination of interleukin 6 and clodronate-liposomes, the NIRG cells down-regulate transitin and perish within the following week, suggesting that the survival and phenotype of NIRG cells are somehow linked to the microglia. We conclude that the abundance, reactivity and retinal distribution of NIRG cells can be dynamic, are regulated by homoestatic mechanisms and are tethered to the microglia.
Collapse
Affiliation(s)
- Christopher P. Zelinka
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Melissa A. Scott
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Leo Volkov
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Andy J. Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
| |
Collapse
|
25
|
Wohl SG, Schmeer CW, Isenmann S. Neurogenic potential of stem/progenitor-like cells in the adult mammalian eye. Prog Retin Eye Res 2012; 31:213-42. [DOI: 10.1016/j.preteyeres.2012.02.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 02/04/2012] [Accepted: 02/06/2012] [Indexed: 11/26/2022]
|
26
|
Fischer AJ. Muller glia, vision-guided ocular growth, retinal stem cells, and a little serendipity: the Cogan lecture. Invest Ophthalmol Vis Sci 2011; 52:7705-10, 7704. [PMID: 21960640 DOI: 10.1167/iovs.11-8330] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hypothesis-driven science is expected to result in a continuum of studies and findings along a discrete path. By comparison, serendipity can lead to new directions that branch into different paths. Herein, I describe a diverse series of findings that were motivated by hypotheses, but driven by serendipity. I summarize how investigations into vision-guided ocular growth in the chick eye led to the identification of glucagonergic amacrine cells as key regulators of ocular elongation. Studies designed to assess the impact of the ablation of different types of neurons on vision-guided ocular growth led to the finding of numerous proliferating cells within damaged retinas. These proliferating cells were Müller glia-derived retinal progenitors with a capacity to produce new neurons. Studies designed to investigate Müller glia-derived progenitors led to the identification of a domain of neural stem cells that form a circumferential marginal zone (CMZ) that lines the periphery of the retina. Accelerated ocular growth, caused by visual deprivation, stimulated the proliferation of CMZ progenitors. We formulated a hypothesis that growth-regulating glucagonergic cells may regulate both overall eye size (scleral growth) and the growth of the retina (proliferation of CMZ cells). Subsequent studies identified unusual types of glucagonergic neurons with terminals that ramify within the CMZ; these cells use visual cues to control equatorial ocular growth and the proliferation of CMZ cells. Finally, while studying the signaling pathways that stimulate CMZ and Müller glia-derived progenitors, serendipity led to the discovery of a novel type of glial cell that is scattered across the inner retinal layers.
Collapse
Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio 43210-1239, USA.
| |
Collapse
|
27
|
Gotoh H, Ueda T, Uno A, Ohuchi H, Ikenaka K, Ono K. Expression of myelin genes in the developing chick retina. Gene Expr Patterns 2011; 11:471-5. [PMID: 21872683 DOI: 10.1016/j.gep.2011.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/04/2011] [Accepted: 08/05/2011] [Indexed: 11/25/2022]
Abstract
In submammalian animals including chicks, the retina contains oligodendrocytes (OLs), and axons in the optic fiber layer are wrapped with compact myelin within the retina; however, the expression of myelin genes in the chick retina has not been demonstrated yet. In the present study, we examined the expression of three myelin genes (proteolipid protein, PLP; myelin basic protein, MBP; cyclic nucleotide phosphodiesterase, CNP) and PLP in the developing chick retina, in comparison to the localization of Mueller cells. In situ hybridization demonstrated that all three myelin genes began to be expressed at E14 in the chick embryo retina. They are mostly restricted to the ganglion cell layer and the optic fiber layer, with a few exceptions in the inner nuclear layer where Mueller cells reside; however, PLP mRNA+ cells do not express glutamine synthetase, or vice versa. The present results elucidate that myelin genes are expressed only by OLs that are mostly localized in the innermost layer of the developing chick retina.
Collapse
Affiliation(s)
- Hitosh Gotoh
- Department of Biology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | | | | | | | | | | |
Collapse
|
28
|
Abstract
Using both NADPH diaphorase and anti-nNOS antibodies, we have identified-from retinal flatmounts-neuronal types in the inner retina of the chicken that are likely to be nitrergic. The two methods gave similar results and yielded a total of 15 types of neurons, comprising 9 amacrine cells, 5 ganglion cells, and 1 centrifugal midbrain neuron. Six of these 15 cell types are ubiquitously distributed, comprising 3 amacrine cells, 2 displaced ganglion cells, and a presumed orthotopic ganglion cell. The remaining nine cell types are regionally restricted within the retina. As previously reported, efferent fibers of midbrain neurons and their postsynaptic partners, the unusual axon-bearing target amacrine cells, are entirely confined to the ventral retina. Also confined to the ventral retina, though with somewhat different distributions, are the "bullwhip" amacrine cells thought to be involved in eye growth, an orthotopic ganglion cell, and two types of large axon-bearing amacrine cells whose dendrites and axons lie in stratum 1 of the inner plexiform layer (IPL). Intracellular fills of these two cell types showed that only a minority of otherwise morphologically indistinguishable neurons are nitrergic. Two amacrine cells that branch throughout the IPL are confined to an equatorial band, and one small-field orthotopic ganglion cell that branches in the proximal IPL is entirely dorsal. These findings suggest that the retina uses different processing on different regions of the visual image, though the benefit of this is presently obscure.
Collapse
|
29
|
Kim JY, Sohn HJ, Seo JH. Characterization of the antigenic phenotype of αB-crystallin-expressing peripapillary glial cells in the developing chick retina. Anat Cell Biol 2011; 44:35-40. [PMID: 21519547 PMCID: PMC3080006 DOI: 10.5115/acb.2011.44.1.35] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 03/08/2011] [Accepted: 03/08/2011] [Indexed: 11/27/2022] Open
Abstract
Radial glia are transdifferentiated into astrocytes within the developing brain and spinal cord. The neural retina contains Müller cells, which are retinal radial glia. Some of the cells that surround the optic nerve head among Müller cells in the chicken retina are called peripapillary glial cells (PPGCs). PPGCs express different molecules compared to typical Müller cells. However, an antigenic PPGC phenotype has not yet been clearly established. In this study, we classified the antigenic PPGC phenotypes and identified the differentiation stages of these cells. At embryonic day (E)8, αB-crystallin-positive PPGCs had a bipolar shape with long processes that traversed entire layers of the retina. Pax2 and vimentin were expressed in αB-crystallin-positive PPGCs. Glial fibrillary acidic protein (GFAP) immunoreactivity was not observed in PPGCs. At E18, αB-crystallin immunoreactivity disappeared from the vitread processes of PPGCs. However, the PPGC cell bodies and ventricular processes contained αB-crystallin protein, and the PPGCs retained the same Pax2-positive/vimentin-positive/GFAP-negative profile as that seen at E8. At post-hatch day 120, αB-crystallin and Pax2 immunoreactivity was not observed, but vimentin and GFAP expression was clearly observed in the presumptive location of the PPGCs. Furthermore, these two proteins overlapped within that location. Considering that vimentin expression is prolonged until the post-hatching period in chicken brain, these findings suggest that Pax2-negative/vimentin-positive/GFAP-positive PPGCs are phenotypically identical to mature astrocytes in this avian species.
Collapse
Affiliation(s)
- Ji Young Kim
- Department of Anatomy, School of Medicine, Chungbuk National University, Cheongju, Korea
| | | | | |
Collapse
|
30
|
Quesada A, Aguilera Y, Caparrós R, Prada FA, Santano C, López-López R, Prada C. Myelin oligodendrocyte-specific protein is expressed in Müller cells of myelinated vertebrate retinas. J Neurosci Res 2011; 89:674-88. [PMID: 21337368 DOI: 10.1002/jnr.22586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 11/19/2010] [Accepted: 11/29/2010] [Indexed: 11/07/2022]
Abstract
The retina of nonmammalian vertebrates has a loose myelin that enwraps the large axons of the ganglion cells in all areas, whereas that of mammals lacks myelin, with some exceptions, such as the rabbit retina, which shows compact myelin restricted to the myelinated streak. Electron microscopy studies in chicken retina showed processes of Müller cells (MCs) and oligodendrocytes enwrapping ganglion cell axons. How each of these cells contributes to chicken retina myelination and whether the MC of other myelinated retinas is involved in myelination remain unknown. By immunohistochemistry, with a monoclonal antibody against myelin oligodendrocyte-specific protein (MOSP), we show that MOSP is intensely expressed in the MC and the optic-fiber layer (OFL) in myelinated but not in unmyelinated retinas. By immunocytochemistry with isolated MCs from the chick and rabbit retinas, we show that MOSP is concentrated in the innermost domain of the vitread processes. By immunoblotting, we show that protein extracts from myelinated retinas, but not those from unmyelinated retinas, presented a single band labelled with anti-MOSP of molecular weight similar to that of brain MOSP. In addition, we show that the MC of the embryonic chicken retina starts to express MOSP just before myelination starts. Our results agree with those of electron microscopy studies showing myelin in chick retina formed by MC processes and with those of immunohistochemistry studies in rabbit and human retinas showing expression of other myelin molecules in the MC. Altogether, our results suggest that the MC in myelinated retinas might contribute MOSP to myelin.
Collapse
Affiliation(s)
- Adela Quesada
- Departamento de Anatomía e Instituto de Biología del Desarrollo, Facultad de Medicina, Universidad de Sevilla, Sevilla, Spain
| | | | | | | | | | | | | |
Collapse
|
31
|
Lee A, Pow DV. Astrocytes: Glutamate transport and alternate splicing of transporters. Int J Biochem Cell Biol 2010; 42:1901-6. [DOI: 10.1016/j.biocel.2010.09.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 09/14/2010] [Accepted: 09/21/2010] [Indexed: 10/19/2022]
|
32
|
Fischer AJ, Bongini R. Turning Müller glia into neural progenitors in the retina. Mol Neurobiol 2010; 42:199-209. [PMID: 21088932 DOI: 10.1007/s12035-010-8152-2] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 11/10/2010] [Indexed: 12/22/2022]
Abstract
Stimulating neuronal regeneration is a potential strategy to treat sight-threatening diseases of the retina. In some classes of vertebrates, retinal regeneration occurs spontaneously to effectively replace neurons lost to acute damage in order to restore visual function. There are different mechanisms and cellular sources of retinal regeneration in different species, include the retinal pigmented epithelium, progenitors seeded across the retina, and the Müller glia. This review briefly summarizes the different mechanisms of retinal regeneration in frogs, fish, chicks, and rodents. The bulk of this review summarizes and discusses recent findings regarding regeneration from Müller glia-derived progenitors, with emphasis on findings in the chick retina. The Müller glia are a promising source of regeneration-supporting cells that are intrinsic to the retina and significant evidence indicated these glias can be stimulated to produce neurons in different classes of vertebrates. The key to harnessing the neurogenic potential of Müller glia is to identify the secreted factors, signaling pathways, and transcription factors that enable de-differentiation, proliferation, and neurogenesis. We review findings regarding the roles of mitogen-activated protein kinase and notch signaling in the proliferation and generation of Müller glia-derived retinal progenitors.
Collapse
Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 West 10th Ave, Columbus, OH 43210-1239, USA.
| | | |
Collapse
|
33
|
Fischer AJ, Zelinka C, Scott MA. Heterogeneity of glia in the retina and optic nerve of birds and mammals. PLoS One 2010; 5:e10774. [PMID: 20567503 PMCID: PMC2887354 DOI: 10.1371/journal.pone.0010774] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 05/04/2010] [Indexed: 11/21/2022] Open
Abstract
We have recently described a novel type of glial cell that is scattered across the inner layers of the avian retina [1]. These cells are stimulated by insulin-like growth factor 1 (IGF1) to proliferate, migrate distally into the retina, and up-regulate the nestin-related intermediate filament transitin. These changes in glial activity correspond with increased susceptibility of neurons to excitotoxic damage. This novel cell-type has been termed the Non-astrocytic Inner Retinal Glia-like (NIRG) cells. The purpose of the study was to investigate whether the retinas of non-avian species contain cells that resemble NIRG cells. We assayed for NIRG cells by probing for the expression of Sox2, Sox9, Nkx2.2, vimentin and nestin. NIRG cells were distinguished from astrocytes by a lack of expression for Glial Fibrilliary Acidic Protein (GFAP). We examined the retinas of adult mice, guinea pigs, dogs and monkeys (Macaca fasicularis). In the mouse retina and optic nerve head, we identified numerous astrocytes that expressed GFAP, S100β, Sox2 and Sox9; however, we found no evidence for NIRG-like cells that were positive for Nkx2.2, nestin, and negative for GFAP. In the guinea pig retina, we did not find astrocytes or NIRG cells in the retina, whereas we identified astrocytes in the optic nerve. In the eyes of dogs and monkeys, we found astrocytes and NIRG-like cells scattered across inner layers of the retina and within the optic nerve. We conclude that NIRG-like cells are present in the retinas of canines and non-human primates, whereas the retinas of mice and guinea pigs do not contain NIRG cells.
Collapse
Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio, USA.
| | | | | |
Collapse
|