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Kelly LE, El-Hodiri HM, Crider A, Fischer AJ. Protein phosphatases regulate the formation of Müller glia-derived progenitor cells in the chick retina. Mol Cell Neurosci 2024; 129:103932. [PMID: 38679247 PMCID: PMC11362962 DOI: 10.1016/j.mcn.2024.103932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/26/2024] [Accepted: 04/18/2024] [Indexed: 05/01/2024] Open
Abstract
Different kinase-dependent cell signaling pathways are known to play important roles in glia-mediated neuroprotection and reprogramming of Müller glia (MG) into Müller glia-derived progenitor cells (MGPCs) in the retina. However, very little is known about the phosphatases that regulate kinase-dependent signaling in MG. Using single-cell RNA-sequencing (scRNA-seq) databases, we investigated patterns of expression of Dual Specificity Phosphatases (DUSP1/6) and other protein phosphatases in normal and damaged chick retinas. We found that DUSP1, DUSP6, PPP3CB, PPP3R1 and PPPM1A/B/D/E/G are widely expressed by many types of retinal neurons and are dynamically expressed by MG and MGPCs in retinas during the process of reprogramming. We find that inhibition of DUSP1/6 and PP2C phosphatases enhances the formation of proliferating MGPCs in damaged retinas and in retinas treated with insulin and FGF2 in the absence of damage. By contrast, inhibition of PP2B phosphatases suppressed the formation of proliferating MGPCs, but increased numbers of proliferating MGPCs in undamaged retinas treated with insulin and FGF2. In damaged retinas, inhibition of DUSP1/6 increased levels of pERK1/2 and cFos in MG whereas inhibition of PP2B's decreased levels of pStat3 and pS6 in MG. Analyses of scRNA-seq libraries identified numerous differentially activated gene modules in MG in damaged retinas versus MG in retinas treated with insulin+FGF2 suggesting significant differences in kinase-dependent signaling pathways that converge on the formation of MGPCs. Inhibition of phosphatases had no significant effects upon numbers of dying cells in damaged retinas. We conclude that the activity of different protein phosphatases acting through retinal neurons and MG "fine-tune" the cell signaling responses of MG in damaged retinas and during the reprogramming of MG into MGPCs.
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Affiliation(s)
- Lisa E Kelly
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Heithem M El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Andrew Crider
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, USA.
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2
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Rueda-Latorre D, Sosa-Lockward JA, Abreu-Arbaje N. Presence of subfoveal hyperreflective dots as an anatomic and functional prognostic biomarker in macular holes. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2024; 99:232-236. [PMID: 38663716 DOI: 10.1016/j.oftale.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 03/12/2024] [Indexed: 04/29/2024]
Abstract
OBJECTIVE To evaluate the presence of subfoveal hyperreflective dots (SfHD) using optical coherence tomography (OCT) in macular holes (MH) and establish whether there is a relationship with postoperative anatomical and functional outcomes. METHODS An observational cross-sectional study was conducted at the Dr. Elías Santana Hospital. Sixty-eight eyes of 67 patients with a tomographic diagnosis of full-thickness MH who underwent pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling were included. Preoperative and postoperative measurements were obtained using radial macular scans and HD raster scans with Optovue and Cirrus 5000 (Zeiss) OCT machines. The main outcome measures were anatomical closure by OCT and functional outcome through best-corrected visual acuity (BCVA). RESULTS The anatomical closure rate in our study was 63%. MHs that failed to achieve anatomical closure exhibited a higher number of hyperreflective dots and worse postoperative BCVA. A statistically significant association was found between exposed retinal pigment epithelium (RPE) in microns and the number of SfHD (P = .001). CONCLUSION SfHD is a common tomographic finding in MH, and the presence of a higher number of these points is associated with poorer anatomical and functional outcomes. This imaging finding is a potential prognostic biomarker in this pathology.
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Affiliation(s)
- D Rueda-Latorre
- Instituto Tecnológico de Santo Domingo (INTEC), Santo Domingo, República Dominicana; Servicio de Oftalmología, Centro Cristiano de Servicios Médicos, Hospital Dr. Elías Santana, Santo Domingo, República Dominicana.
| | - J A Sosa-Lockward
- Instituto Tecnológico de Santo Domingo (INTEC), Santo Domingo, República Dominicana; Servicio de Oftalmología, Centro Cristiano de Servicios Médicos, Hospital Dr. Elías Santana, Santo Domingo, República Dominicana; Departamento de Retina y Vítreo, Hospital Dr. Elías Santana, Santo Domingo, República Dominicana
| | - N Abreu-Arbaje
- Instituto Tecnológico de Santo Domingo (INTEC), Santo Domingo, República Dominicana; Servicio de Oftalmología, Centro Cristiano de Servicios Médicos, Hospital Dr. Elías Santana, Santo Domingo, República Dominicana; Departamento de Retina y Vítreo, Hospital Dr. Elías Santana, Santo Domingo, República Dominicana
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3
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El-Desoky SMM, Elhanbaly R, Hifny A, Ibrahim N, Gaber W. Temporospatial dynamics of the morphogenesis of the rabbit retina from prenatal to postnatal life: Light and electron microscopic study. Microsc Res Tech 2024; 87:774-789. [PMID: 38062556 DOI: 10.1002/jemt.24466] [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: 08/03/2023] [Revised: 10/24/2023] [Accepted: 11/19/2023] [Indexed: 03/02/2024]
Abstract
The retina consists of various cell types arranged in eight cell layers and two membranes that originate from the neuroectodermal cells. In this study, the timing of differentiation and distribution of the cellular components and the layers of the rabbit retina are investigated using light and electron microscopy and immunohistochemical techniques. There were 32 rabbit embryos and 12 rabbits used. The rabbit retina begins its prenatal development on the 10th day of gestation in the form of optic cup. The process of neuro- and gliogenesis occurs in several stages: In the first stage, the ganglionic cells are differentiated at the 15th day. The second stage includes the differentiation of Muller, amacrine, and cone cells on the 23rd day. The differentiation of bipolar, horizontal, and rod cells and formation of the inner segments of the photoreceptors consider the late stage that occurs by the 27th and 30th day of gestation. On the first week of age postnatally, the outer segments of the photoreceptors are developed. S100 protein is expressed by the Muller cells and its processes that traverse the retina from the outer to the inner limiting membranes. Calretinin is intensely labeled within the amacrine and displaced amacrine cells. Ganglionic cells exhibited moderate immunoreactivity for calretinin confined to their cytoplasm and dendrites. In conclusion, all stages of neuro- and gliogenesis of the rabbit retina occur during the embryonic period. Then, the retina continues its development postnatally by formation of the photoreceptor outer segments and all layers of the retina become established. RESEARCH HIGHLIGHTS: The aim of this study is to investigate the morphogenesis of the rabbit retina during pre- and postnatal life. The primordia of the retina could be observed in the form of the optic cup. The ganglionic cells are the first cells to differentiate, while the photoreceptor cells are the last. S100 protein is expressed by the Muller cells and its processes. Calretinin is intensely labeled in the amacrine and displaced amacrine cells and moderately expressed in the cytoplasm and dendrites of ganglionic cells.
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Affiliation(s)
- Sara M M El-Desoky
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Ruwaida Elhanbaly
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Abdalla Hifny
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Nagwa Ibrahim
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Wafaa Gaber
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
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4
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Kelly LE, El-Hodiri HM, Crider A, Fischer AJ. Protein phosphatases regulate the formation of Müller glia-derived progenitor cells in the chick retina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.11.570629. [PMID: 38168320 PMCID: PMC10760049 DOI: 10.1101/2023.12.11.570629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Different kinase-dependent cell signaling pathways are known to play important roles in glia-mediated neuroprotection and reprogramming of Müller glia (MG) into Müller glia-derived progenitor cells (MGPCs) in the retina. However, very little is known about the phosphatases that regulate kinase-dependent signaling in MG. Using single-cell RNA-sequencing (scRNA-seq) databases, we investigated patterns of expression of Dual Specificity Phosphatases (DUSP1/6) and other protein phosphatases in normal and damaged chick retinas. We found that DUSP1, DUSP6, PPP3CB, PPP3R1 and PPPM1A/B/D/E/G are dynamically expressed by MG and MGPCs in retinas during the process of reprogramming. We find that inhibition of DUSP1/6 and PP2C phosphatases enhances the formation of proliferating MGPCs in damaged retinas and in retinas treated with insulin in FGF2 in the absence of damage. By contrast, inhibition of PP2B phosphatases suppressed the formation of proliferating MGPCs, but increased numbers of proliferating MGPCs in undamaged retinas treated with insulin and FGF2. In damaged retinas, inhibition of DUSP1/6 increased levels of pERK1/2 and cFos in MG whereas inhibition of PP2B's decreased levels of pStat3 and pS6 in MG. Analyses of scRNA-seq libraries identified numerous differentially activated gene modules in MG in damaged retinas versus MG in retinas treated with insulin+FGF2 suggesting significant differences in kinase-dependent signaling pathways that converge on the formation of MGPCs. Inhibition of phosphatases had no significant effects upon numbers of dying cells in damaged retinas. We conclude that the activity of different protein phosphatases "fine-tune" the cell signaling responses of MG in damaged retinas and during the reprogramming of MG into MGPCs.
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Affiliation(s)
- Lisa E. Kelly
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Heithem M. El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Andrew Crider
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Andy J. Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
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5
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Pan D, Zhang X, Jin K, Jin ZB. CRX haploinsufficiency compromises photoreceptor precursor translocation and differentiation in human retinal organoids. Stem Cell Res Ther 2023; 14:346. [PMID: 38049871 PMCID: PMC10696917 DOI: 10.1186/s13287-023-03590-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 11/28/2023] [Indexed: 12/06/2023] Open
Abstract
BACKGROUND The CRX-associated autosomal dominant retinopathies suggest a possible pathogenic mechanism of gene haploinsufficiency. However, based on reported human patient cases and studies with mouse models, it is hard to confirm the specific weight of haploinsufficiency in pathogenesis due to the interspecies gaps between gene expression and function. METHODS We created monoallelic CRX by replacing one allele with tdTomato in human embryonic stem cells (hESCs) and subsequently dissect pathogenesis in hESCs-derived retinal organoids. We used transcriptome and immunofluorescence analyses to dissect phenotypic differences between CRX-monoallelic knockout and control wildtype organoids. For location analysis of CRX+ cells, a CRX-expression-tracing system was constructed in control hESCs. We implemented long-term live-cell imaging to describe the translocation of CRX+ cells between two groups in early organoid differentiation. The expression pattern of these dynamic differences was validated using RNA-seq and immunofluorescence assays. RESULTS We identified delayed differentiation of outer nuclear layer (ONL) stratification along with thinner ONL, serious loss of photoreceptor outer segments, as well as downregulated expression of gene for phototransduction and inner/outer segment formation. By live-cell imaging and immunostaining, we observed the overtension of actomyosin network and the arrested translocation of monoallelic CRX+ cells in the early stage of retinal differentiation. CONCLUSIONS We confirmed that gene haploinsufficiency is the mechanism for the dominant pathogenicity of CRX and discovered that CRX regulated postmitotic photoreceptor precursor translocation in addition to its specification of photoreceptor cell fates during human retinal development. These findings revealed a new underlying mechanism of CRX dominant pathogenesis and provided a new clue for the treatment of CRX-associated human retinopathies.
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Affiliation(s)
- Deng Pan
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
| | - Xiao Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Kangxin Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
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El-Hodiri HM, Bentley JR, Reske AG, Taylor OB, Palazzo I, Campbell WA, Halloy NR, Fischer AJ. Heparin-binding epidermal growth factor and fibroblast growth factor 2 rescue Müller glia-derived progenitor cell formation in microglia- and macrophage-ablated chick retinas. Development 2023; 150:dev202070. [PMID: 37971210 PMCID: PMC10730090 DOI: 10.1242/dev.202070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023]
Abstract
Recent studies have demonstrated the impact of pro-inflammatory signaling and reactive microglia/macrophages on the formation of Müller glial-derived progenitor cells (MGPCs) in the retina. In chick retina, ablation of microglia/macrophages prevents the formation of MGPCs. Analyses of single-cell RNA-sequencing chick retinal libraries revealed that quiescent and activated microglia/macrophages have a significant impact upon the transcriptomic profile of Müller glia (MG). In damaged monocyte-depleted retinas, MG fail to upregulate genes related to different cell signaling pathways, including those related to Wnt, heparin-binding epidermal growth factor (HBEGF), fibroblast growth factor (FGF) and retinoic acid receptors. Inhibition of GSK3β, to simulate Wnt signaling, failed to rescue the deficit in MGPC formation, whereas application of HBEGF or FGF2 completely rescued the formation of MGPCs in monocyte-depleted retinas. Inhibition of Smad3 or activation of retinoic acid receptors partially rescued the formation of MGPCs in monocyte-depleted retinas. We conclude that signals produced by reactive microglia/macrophages in damaged retinas stimulate MG to upregulate cell signaling through HBEGF, FGF and retinoic acid, and downregulate signaling through TGFβ/Smad3 to promote the reprogramming of MG into proliferating MGPCs.
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Affiliation(s)
- Heithem M. El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
| | - James R. Bentley
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
| | - Alana G. Reske
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
| | - Olivia B. Taylor
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
| | - Isabella Palazzo
- Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Warren A. Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
| | - Nicklaus R. Halloy
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
| | - Andy J. Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43221, USA
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7
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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 PMCID: PMC11335016 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.
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Affiliation(s)
- Warren A. Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Heithem M. El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Diego Torres
- 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
| | - Lisa E. Kelly
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Leo Volkov
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| | - David Akanonu
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
| | - Andy J. Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
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8
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El-Hodiri HM, Bentley J, Reske A, Palazzo I, Campbell WA, Halloy NR, Fischer AJ. Formation of Müller glia-derived progenitor cells in retinas depleted of microglia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.08.544205. [PMID: 37333380 PMCID: PMC10274900 DOI: 10.1101/2023.06.08.544205] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Recent studies have demonstrated the complex coordination of pro-inflammatory signaling and reactive microglia/macrophage on the formation Müller glial-derived progenitor cells (MGPCs) in the retinas of fish, birds and mice. We generated scRNA-seq libraries to identify transcriptional changes in Müller glia (MG) that result from the depletion of microglia from the chick retina. We found significant changes in different networks of genes in MG in normal and damaged retinas when the microglia are ablated. We identified a failure of MG to upregulate Wnt-ligands, Heparin binding epidermal growth factor (HBEGF), Fibroblast growth factor (FGF), retinoic acid receptors and genes related to Notch-signaling. Inhibition of GSK3β, to simulate Wnt-signaling, failed to rescue the deficit in formation of proliferating MGPCs in damaged retinas missing microglia. By comparison, application of HBEGF or FGF2 completely rescued the formation of proliferating MGPCs in microglia-depleted retinas. Similarly, injection of a small molecule inhibitor to Smad3 or agonist to retinoic acid receptors partially rescued the formation of proliferating MGPCs in microglia-depleted damaged retinas. According to scRNA-seq libraries, patterns of expression of ligands, receptors, signal transducers and/or processing enzymes to cell-signaling via HBEGF, FGF, retinoic acid and TGFβ are rapidly and transiently upregulated by MG after neuronal damage, consistent with important roles for these cell-signaling pathways in regulating the formation of MGPCs. We conclude that quiescent and activated microglia have a significant impact upon the transcriptomic profile of MG. We conclude that signals produced by reactive microglia in damaged retinas stimulate MG to upregulate cell signaling through HBEGF, FGF and retinoic acid, and downregulate signaling through TGFβ/Smad3 to promote the reprogramming on MG into proliferating MGPCs.
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Affiliation(s)
- Heithem M. El-Hodiri
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - James Bentley
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Alana Reske
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Isabella Palazzo
- Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD
| | - Warren A. Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Nicklaus R. Halloy
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
| | - Andy J. Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH
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Wu S, Mo X. Optic Nerve Regeneration in Diabetic Retinopathy: Potentials and Challenges Ahead. Int J Mol Sci 2023; 24:ijms24021447. [PMID: 36674963 PMCID: PMC9865663 DOI: 10.3390/ijms24021447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 12/31/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Diabetic retinopathy (DR), the most common microvascular compilation of diabetes, is the leading cause of vision loss and blindness worldwide. Recent studies indicate that retinal neuron impairment occurs before any noticeable vascular changes in DR, and retinal ganglion cell (RGC) degeneration is one of the earliest signs. Axons of RGCs have little capacity to regenerate after injury, clinically leading the visual functional defects to become irreversible. In the past two decades, tremendous progress has been achieved to enable RGC axon regeneration in animal models of optic nerve injury, which holds promise for neural repair and visual restoration in DR. This review summarizes these advances and discusses the potential and challenges for developing optic nerve regeneration strategies treating DR.
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Affiliation(s)
| | - Xiaofen Mo
- Correspondence: ; Tel.: +86-021-64377134
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10
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Miranda-Negrón Y, García-Arrarás JE. Radial glia and radial glia-like cells: Their role in neurogenesis and regeneration. Front Neurosci 2022; 16:1006037. [PMID: 36466166 PMCID: PMC9708897 DOI: 10.3389/fnins.2022.1006037] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 10/21/2022] [Indexed: 01/25/2024] Open
Abstract
Radial glia is a cell type traditionally associated with the developing nervous system, particularly with the formation of cortical layers in the mammalian brain. Nonetheless, some of these cells, or closely related types, called radial glia-like cells are found in adult central nervous system structures, functioning as neurogenic progenitors in normal homeostatic maintenance and in response to injury. The heterogeneity of radial glia-like cells is nowadays being probed with molecular tools, primarily by the expression of specific genes that define cell types. Similar markers have identified radial glia-like cells in the nervous system of non-vertebrate organisms. In this review, we focus on adult radial glia-like cells in neurogenic processes during homeostasis and in response to injury. We highlight our results using a non-vertebrate model system, the echinoderm Holothuria glaberrima where we have described a radial glia-like cell that plays a prominent role in the regeneration of the holothurian central nervous system.
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Affiliation(s)
| | - José E. García-Arrarás
- Department of Biology, College of Natural Sciences, University of Puerto Rico, San Juan, Puerto Rico
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11
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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.
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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
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12
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Chang KC. Influence of Sox protein SUMOylation on neural development and regeneration. Neural Regen Res 2022; 17:477-481. [PMID: 34380874 PMCID: PMC8504373 DOI: 10.4103/1673-5374.320968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
SRY-related HMG-box (Sox) transcription factors are known to regulate central nervous system development and are involved in several neurological diseases. Post-translational modification of Sox proteins is known to alter their functions in the central nervous system. Among the different types of post-translational modification, small ubiquitin-like modifier (SUMO) modification of Sox proteins has been shown to modify their transcriptional activity. Here, we review the mechanisms of three Sox proteins in neuronal development and disease, along with their transcriptional changes under SUMOylation. Across three species, lysine is the conserved residue for SUMOylation. In Drosophila, SUMOylation of SoxN plays a repressive role in transcriptional activity, which impairs central nervous system development. However, deSUMOylation of SoxE and Sox11 plays neuroprotective roles, which promote neural crest precursor formation in Xenopus and retinal ganglion cell differentiation as well as axon regeneration in the rodent. We further discuss a potential translational therapy by SUMO site modification using AAV gene transduction and Clustered regularly interspaced short palindromic repeats-Cas9 technology. Understanding the underlying mechanisms of Sox SUMOylation, especially in the rodent system, may provide a therapeutic strategy to address issues associated with neuronal development and neurodegeneration.
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Affiliation(s)
- Kun-Che Chang
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Targeting RGD-binding integrins as an integrative therapy for diabetic retinopathy and neovascular age-related macular degeneration. Prog Retin Eye Res 2021; 85:100966. [PMID: 33775825 DOI: 10.1016/j.preteyeres.2021.100966] [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: 01/08/2021] [Revised: 03/15/2021] [Accepted: 03/19/2021] [Indexed: 12/14/2022]
Abstract
Integrins are a class of transmembrane receptors that are involved in a wide range of biological functions. Dysregulation of integrins has been implicated in many pathological processes and consequently, they are attractive therapeutic targets. In the ophthalmology arena, there is extensive evidence suggesting that integrins play an important role in diabetic retinopathy (DR), age-related macular degeneration (AMD), glaucoma, dry eye disease and retinal vein occlusion. For example, there is extensive evidence that arginyl-glycyl-aspartic acid (Arg-Gly-Asp; RGD)-binding integrins are involved in key disease hallmarks of DR and neovascular AMD (nvAMD), specifically inflammation, vascular leakage, angiogenesis and fibrosis. Based on such evidence, drugs that engage integrin-linked pathways have received attention for their potential to block all these vision-threatening pathways. This review focuses on the pathophysiological role that RGD-binding integrins can have in complex multifactorial retinal disorders like DR, diabetic macular edema (DME) and nvAMD, which are leading causes of blindness in developed countries. Special emphasis will be given on how RGD-binding integrins can modulate the intricate molecular pathways and regulate the underlying pathological mechanisms. For instance, the interplay between integrins and key molecular players such as growth factors, cytokines and enzymes will be summarized. In addition, recent clinical advances linked to targeting RGD-binding integrins in the context of DME and nvAMD will be discussed alongside future potential for limiting progression of these diseases.
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14
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Kang S, Larbi D, Andrade M, Reardon S, Reh TA, Wohl SG. A Comparative Analysis of Reactive Müller Glia Gene Expression After Light Damage and microRNA-Depleted Müller Glia-Focus on microRNAs. Front Cell Dev Biol 2021; 8:620459. [PMID: 33614628 PMCID: PMC7891663 DOI: 10.3389/fcell.2020.620459] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 12/18/2020] [Indexed: 12/12/2022] Open
Abstract
Müller glia (MG) are the predominant glia in the neural retina and become reactive after injury or in disease. microRNAs (miRNAs) are translational repressors that regulate a variety of processes during development and are required for MG function. However, no data is available about the MG miRNAs in reactive gliosis. Therefore, in this study, we aimed to profile miRNAs and mRNAs in reactive MG 7 days after light damage. Light damage was performed for 8 h at 10,000 lux; this leads to rapid neuronal loss and strong MG reactivity. miRNAs were profiled using the Nanostring platform, gene expression analysis was conducted via microarray. We compared the light damage dataset with the dataset of Dicer deleted MG in order to find similarities and differences. We found: (1) The vast majority of MG miRNAs declined in reactive MG 7 days after light damage. (2) Only four miRNAs increased after light damage, which included miR-124. (3) The top 10 genes found upregulated in reactive MG after light damage include Gfap, Serpina3n, Ednrb and Cxcl10. (4) The miRNA decrease in reactive MG 7 days after injury resembles the profile of Dicer-depleted MG after one month. (5) The comparison of both mRNA expression datasets (light damage and Dicer-cKO) showed 1,502 genes were expressed under both conditions, with Maff , Egr2, Gadd45b, and Atf3 as top upregulated candidates. (6) The DIANA-TarBase v.8 miRNA:RNA interaction tool showed that three miRNAs were found to be present in all networks, i.e., after light damage, and in the combined data set; these were miR-125b-5p, let-7b and let-7c. Taken together, results show there is an overlap of gene regulatory events that occur in reactive MG after light damage (direct damage of neurons) and miRNA-depleted MG (Dicer-cKO), two very different paradigms. This suggests that MG miRNAs play an important role in a ubiquitous MG stress response and manipulating these miRNAs could be a first step to attenuate gliosis.
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Affiliation(s)
- Seoyoung Kang
- Department of Biological and Vision Sciences, College of Optometry, The State University of New York, New York, NY, United States
| | - Daniel Larbi
- Department of Biological and Vision Sciences, College of Optometry, The State University of New York, New York, NY, United States
| | - Monica Andrade
- Department of Biological and Vision Sciences, College of Optometry, The State University of New York, New York, NY, United States
| | - Sara Reardon
- Department of Biological Structure, School of Medicine, University of Washington, Seattle, WA, United States
| | - Thomas A. Reh
- Department of Biological Structure, School of Medicine, University of Washington, Seattle, WA, United States
| | - Stefanie G. Wohl
- Department of Biological and Vision Sciences, College of Optometry, The State University of New York, New York, NY, United States
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15
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Microfluidic and Microscale Assays to Examine Regenerative Strategies in the Neuro Retina. MICROMACHINES 2020; 11:mi11121089. [PMID: 33316971 PMCID: PMC7763644 DOI: 10.3390/mi11121089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/03/2020] [Accepted: 12/05/2020] [Indexed: 12/15/2022]
Abstract
Bioengineering systems have transformed scientific knowledge of cellular behaviors in the nervous system (NS) and pioneered innovative, regenerative therapies to treat adult neural disorders. Microscale systems with characteristic lengths of single to hundreds of microns have examined the development and specialized behaviors of numerous neuromuscular and neurosensory components of the NS. The visual system is comprised of the eye sensory organ and its connecting pathways to the visual cortex. Significant vision loss arises from dysfunction in the retina, the photosensitive tissue at the eye posterior that achieves phototransduction of light to form images in the brain. Retinal regenerative medicine has embraced microfluidic technologies to manipulate stem-like cells for transplantation therapies, where de/differentiated cells are introduced within adult tissue to replace dysfunctional or damaged neurons. Microfluidic systems coupled with stem cell biology and biomaterials have produced exciting advances to restore vision. The current article reviews contemporary microfluidic technologies and microfluidics-enhanced bioassays, developed to interrogate cellular responses to adult retinal cues. The focus is on applications of microfluidics and microscale assays within mammalian sensory retina, or neuro retina, comprised of five types of retinal neurons (photoreceptors, horizontal, bipolar, amacrine, retinal ganglion) and one neuroglia (Müller), but excludes the non-sensory, retinal pigmented epithelium.
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Fleming T, Balderas-Márquez JE, Epardo D, Ávila-Mendoza J, Carranza M, Luna M, Harvey S, Arámburo C, Martínez-Moreno CG. Growth Hormone Neuroprotection Against Kainate Excitotoxicity in the Retina is Mediated by Notch/PTEN/Akt Signaling. Invest Ophthalmol Vis Sci 2020; 60:4532-4547. [PMID: 31675424 DOI: 10.1167/iovs.19-27473] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In the retina, growth hormone (GH) promotes axonal growth, synaptic restoration, and protective actions against excitotoxicity. Notch signaling pathway is critical for neural development and participates in the retinal neuroregenerative process. We investigated the interaction of GH with Notch signaling pathway during its neuroprotective effect against excitotoxic damage in the chicken retina. Methods Kainate (KA) was used as excitotoxic agent and changes in the mRNA expression of several signaling markers were determined by qPCR. Also, changes in phosphorylation and immunoreactivity were determined by Western blotting. Histology and immunohistochemistry were performed for morphometric analysis. Overexpression of GH was performed in the quail neuroretinal-derived immortalized cell line (QNR/D) cell line. Exogenous GH was administered to retinal primary cell cultures to study the activation of signaling pathways. Results KA disrupted the retinal cytoarchitecture and induced significant cell loss in several retinal layers, but the coaddition of GH effectively prevented these adverse effects. We showed that GH upregulates the Notch signaling pathway during neuroprotection leading to phosphorylation of the PI3K/Akt signaling pathways through downregulation of PTEN. In contrast, cotreatment of GH with the Notch signaling inhibitor, DAPT, prevented its neuroprotective effect against KA. We identified binding sites in Notch1 and Notch2 genes for STAT5. Also, GH prevented Müller cell transdifferentiation and downregulated Sox2, FGF2, and PCNA after cotreatment with KA. Additionally, GH modified TNF receptors immunoreactivity suggesting anti-inflammatory actions. Conclusions Our data indicate that the neuroprotective effects of GH against KA injury in the retina are mediated through the regulation of Notch signaling. Additionally, anti-inflammatory and antiproliferative effects were observed.
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Affiliation(s)
- Thomas Fleming
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México.,Department of Physiology, University of Alberta, Edmonton, Canada
| | - Jerusa E Balderas-Márquez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - David Epardo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - José Ávila-Mendoza
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States
| | - Martha Carranza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Maricela Luna
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Steve Harvey
- Department of Physiology, University of Alberta, Edmonton, Canada
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
| | - Carlos G Martínez-Moreno
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, México
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17
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Gong X, Wu XH, Liu AL, Qian KW, Li YY, Ma YY, Huang F, Wang Q, Wu H, Zhou X, Qu J, Yuan F, Zhong YM, Yang XL, Weng SJ. Optic nerve crush modulates refractive development of the C57BL/6 mouse by changing multiple ocular dimensions. Brain Res 2019; 1726:146537. [PMID: 31672473 DOI: 10.1016/j.brainres.2019.146537] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 10/17/2019] [Accepted: 10/26/2019] [Indexed: 01/16/2023]
Abstract
Higher visual centers could modulate visually-guided ocular growth, in addition to local mechanisms intrinsic to the eye. There is evidence that such central modulations could be species (even subspecies)-dependent. While the mouse has recently become an important experimental animal in myopia studies, it remains unclear whether and how visual centers modulate refractive development in mice, an issue that was examined in the present study. We found that optic nerve crush (ONC), performed at P18, could modify normal refractive development in the C57BL/6 mouse raised in normal visual environment. Unexpectedly, sham surgery caused a steeper cornea, leading to a modest myopic refractive shift, but did not induce significant changes in ocular axis length. ONC caused corneal flattening and re-calibrated the refractive set-point in a bidirectional manner, causing significant myopic (<-3 D, 54.5%) or hyperopic (>+3 D, 18.2%) shifts in refractive error in most (totally 72.7%) animals, both due to changes in ocular axial length. ONC did not change the density of dopaminergic amacrine cells, but increased retinal levels of dopamine and DOPAC. We conclude that higher visual centers are likely to play a role in fine-tuning of ocular growth, thus modifying refractive development in the C57BL/6 mouse. The changes in refractive error induced by ONC are accounted for by alternations in multiple ocular dimensions, including corneal curvature and axial length.
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Affiliation(s)
- Xue Gong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiao-Hua Wu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China; Discipline of Neuroscience and Department of Anatomy and Physiology, College of Basic Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ai-Lin Liu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Kang-Wei Qian
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yun-Yun Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuan-Yuan Ma
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Furong Huang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qiongsi Wang
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Hao Wu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiangtian Zhou
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jia Qu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fei Yuan
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yong-Mei Zhong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xiong-Li Yang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shi-Jun Weng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Department of Neurology and Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China.
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18
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Martinez-Moreno CG, Epardo D, Balderas-Márquez JE, Fleming T, Carranza M, Luna M, Harvey S, Arámburo C. Regenerative Effect of Growth Hormone (GH) in the Retina after Kainic Acid Excitotoxic Damage. Int J Mol Sci 2019; 20:E4433. [PMID: 31509934 PMCID: PMC6770150 DOI: 10.3390/ijms20184433] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 02/06/2023] Open
Abstract
In addition to its role as an endocrine messenger, growth hormone (GH) also acts as a neurotrophic factor in the central nervous system (CNS), whose effects are involved in neuroprotection, axonal growth, and synaptogenic modulation. An increasing amount of clinical evidence shows a beneficial effect of GH treatment in patients with brain trauma, stroke, spinal cord injury, impaired cognitive function, and neurodegenerative processes. In response to injury, Müller cells transdifferentiate into neural progenitors and proliferate, which constitutes an early regenerative process in the chicken retina. In this work, we studied the long-term protective effect of GH after causing severe excitotoxic damage in the retina. Thus, an acute neural injury was induced via the intravitreal injection of kainic acid (KA, 20 µg), which was followed by chronic administration of GH (10 injections [300 ng] over 21 days). Damage provoked a severe disruption of several retinal layers. However, in KA-damaged retinas treated with GH, we observed a significant restoration of the inner plexiform layer (IPL, 2.4-fold) and inner nuclear layer (INL, 1.5-fold) thickness and a general improvement of the retinal structure. In addition, we also observed an increase in the expression of several genes involved in important regenerative pathways, including: synaptogenic markers (DLG1, NRXN1, GAP43); glutamate receptor subunits (NR1 and GRIK4); pro-survival factors (BDNF, Bcl-2 and TNF-R2); and Notch signaling proteins (Notch1 and Hes5). Interestingly, Müller cell transdifferentiation markers (Sox2 and FGF2) were upregulated by this long-term chronic GH treatment. These results are consistent with a significant increase in the number of BrdU-positive cells observed in the KA-damaged retina, which was induced by GH administration. Our data suggest that GH is able to facilitate the early proliferative response of the injured retina and enhance the regeneration of neurite interconnections.
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Affiliation(s)
- Carlos G Martinez-Moreno
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico.
| | - David Epardo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico
| | - Jerusa E Balderas-Márquez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico.
| | - Thomas Fleming
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico.
| | - Martha Carranza
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico.
| | - Maricela Luna
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico.
| | - Steve Harvey
- Department of Physiology, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | - Carlos Arámburo
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Campus Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Qro., 76230, Mexico.
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Campbell WA, Deshmukh A, Blum S, Todd L, Mendonca N, Weist J, Zent J, Hoang TV, Blackshaw S, Leight J, Fischer AJ. Matrix-metalloproteinase expression and gelatinase activity in the avian retina and their influence on Müller glia proliferation. Exp Neurol 2019; 320:112984. [PMID: 31251936 DOI: 10.1016/j.expneurol.2019.112984] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 06/15/2019] [Accepted: 06/24/2019] [Indexed: 12/16/2022]
Abstract
Gelatinases are a class of matrix metalloproteinases (MMPs) that degrade the extracellular matrix (ECM) to regulate intercellular signaling and cell migration. Gelatinase activity is tightly regulated via proteolytic activation and through the expression of tissue inhibitors of matrix metalloproteinases (TIMPs). Gelatinase activity has been implicated in retinal pathophysiology in different animal models and human disease. However, the role of gelatinases in retinal regeneration remains uncertain. In this study we investigated the dynamic changes in gelatinase activity in response to excitotoxic damage and how this enzymatic activity influenced the formation of Müller glia progenitor cells (MGPCs) in the avian retina. This study used hydrogels containing a gelatinase-degradable fluorescent peptide to measure gelatinase activity in vitro and dye quenched gelatin to localize enzymatic activity in situ. These data were corroborated by using single cell RNA sequencing (scRNA-seq). Gelatinase mRNA, specifically MMP2, was detected in oligodendrocytes and Non-Astrocytic Inner Retinal Glia (NIRG). Total retinal gelatinase activity was reduced following NMDA-treatment, and sustained inhibition of MMP2 prior to damage or growth factor treatment increased the formation of proliferating MGPCs and c-fos signaling. We observed that microglia, Müller glia (MG), and NIRG cells were involved in regulating changes in gelatinase activity through TIMP2 and TIMP3. Collectively, these findings implicate MMP2 in reprogramming of Muller glia into MGPCs.
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Affiliation(s)
- Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Ameya Deshmukh
- Department of Biomedical Engineering, College of Engineering, The comprehensive Cancer Center, The Ohio State University, Columbus, OH, United States of America
| | - Sydney Blum
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Levi Todd
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Ninoshka Mendonca
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, United States of America
| | - Jessica Weist
- Department of Biomedical Engineering, College of Engineering, The comprehensive Cancer Center, The Ohio State University, Columbus, OH, United States of America
| | - Joshua Zent
- Department of Biomedical Engineering, College of Engineering, The comprehensive Cancer Center, The Ohio State University, Columbus, OH, United States of America
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
| | - Jennifer Leight
- Department of Biomedical Engineering, College of Engineering, The comprehensive Cancer Center, The Ohio State University, Columbus, OH, United States of America
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH, United States of America.
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Terrell D, Comander J. Current Stem-Cell Approaches for the Treatment of Inherited Retinal Degenerations. Semin Ophthalmol 2019; 34:287-292. [DOI: 10.1080/08820538.2019.1620808] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- David Terrell
- Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Jason Comander
- Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
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21
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Rabesandratana O, Goureau O, Orieux G. Pluripotent Stem Cell-Based Approaches to Explore and Treat Optic Neuropathies. Front Neurosci 2018; 12:651. [PMID: 30294255 PMCID: PMC6158340 DOI: 10.3389/fnins.2018.00651] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/30/2018] [Indexed: 12/15/2022] Open
Abstract
Sight is a major sense for human and visual impairment profoundly affects quality of life, especially retinal degenerative diseases which are the leading cause of irreversible blindness worldwide. As for other neurodegenerative disorders, almost all retinal dystrophies are characterized by the specific loss of one or two cell types, such as retinal ganglion cells, photoreceptor cells, or retinal pigmented epithelial cells. This feature is a critical point when dealing with cell replacement strategies considering that the preservation of other cell types and retinal circuitry is a prerequisite. Retinal ganglion cells are particularly vulnerable to degenerative process and glaucoma, the most common optic neuropathy, is a frequent retinal dystrophy. Cell replacement has been proposed as a potential approach to take on the challenge of visual restoration, but its application to optic neuropathies is particularly challenging. Many obstacles need to be overcome before any clinical application. Beyond their survival and differentiation, engrafted cells have to reconnect with both upstream synaptic retinal cell partners and specific targets in the brain. To date, reconnection of retinal ganglion cells with distal central targets appears unrealistic since central nervous system is refractory to regenerative processes. Significant progress on the understanding of molecular mechanisms that prevent central nervous system regeneration offer hope to overcome this obstacle in the future. At the same time, emergence of reprogramming of human somatic cells into pluripotent stem cells has facilitated both the generation of new source of cells with therapeutic potential and the development of innovative methods for the generation of transplantable cells. In this review, we discuss the feasibility of stem cell-based strategies applied to retinal ganglion cells and optic nerve impairment. We present the different strategies for the generation, characterization and the delivery of transplantable retinal ganglion cells derived from pluripotent stem cells. The relevance of pluripotent stem cell-derived retinal organoid and retinal ganglion cells for disease modeling or drug screening will be also introduced in the context of optic neuropathies.
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Affiliation(s)
| | - Olivier Goureau
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Gaël Orieux
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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22
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Mitchell DM, Lovel AG, Stenkamp DL. Dynamic changes in microglial and macrophage characteristics during degeneration and regeneration of the zebrafish retina. J Neuroinflammation 2018; 15:163. [PMID: 29804544 PMCID: PMC5971432 DOI: 10.1186/s12974-018-1185-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 04/30/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND In contrast to mammals, zebrafish have the capacity to regenerate retinal neurons following a variety of injuries. Two types of glial cells, Müller glia (MG) and microglia, are known to exist in the zebrafish retina. Recent work has shown that MG give rise to regenerated retinal neurons, but the role of resident microglia, and the innate immune system more generally, during retinal regeneration is not well defined. Specifically, characteristics of the immune system and microglia following substantial neuron death and a successful regenerative response have not been documented. METHODS The neurotoxin ouabain was used to induce a substantial retinal lesion of the inner retina in zebrafish. This lesion results in a regenerative response that largely restores retinal architecture, neuronal morphologies, and connectivities, as well as recovery of visual function. We analyzed cryosections from damaged eyes following immunofluorescence and H&E staining to characterize the initial immune response to the lesion. Whole retinas were analyzed by confocal microscopy to characterize microglia morphology and distribution. Statistical analysis was performed using a two-tailed Student's t test comparing damaged to control samples. RESULTS We find evidence of early leukocyte infiltration to the retina in response to ouabain injection followed by a period of immune cell proliferation that likely includes both resident microglia and substantial numbers of proliferating, extra-retinally derived macrophages, leading to rapid accumulation upon retinal damage. Following immune cell proliferation, Müller glia re-enter the cell cycle. In retinas that have regenerated the layers lost to the initial injury (histologically regenerated), microglia retain morphological features of activation, suggesting ongoing functions that are likely essential to restoration of retinal function. CONCLUSIONS Collectively, these results indicate that microglia and the immune system are dynamic during a successful regenerative response in the retina. This study provides an important framework to probe inflammation in the initiation of, and functional roles of microglia during retinal regeneration.
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Affiliation(s)
- Diana M. Mitchell
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844-3051 USA
| | - Anna G. Lovel
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844-3051 USA
| | - Deborah L. Stenkamp
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844-3051 USA
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Report on the National Eye Institute's Audacious Goals Initiative: Creating a Cellular Environment for Neuroregeneration. eNeuro 2018; 5:eN-COM-0035-18. [PMID: 29766041 PMCID: PMC5952320 DOI: 10.1523/eneuro.0035-18.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 03/01/2018] [Accepted: 03/01/2018] [Indexed: 12/16/2022] Open
Abstract
The cellular environment of the CNS is non-permissive for growth and regeneration. In the retina, transplantation of stem cells has been limited by inefficient survival and integration into existing circuits. In November 2016, as part of the National Eye Institute's Audacious Goals Initiative (AGI), a diverse collection of investigators gathered for a workshop devoted to articulating the gaps in knowledge, barriers to progress, and ideas for new approaches to understanding cellular environments within the retina and how these environments may be manipulated. In doing so, the group identified the areas of (1) retinal and optic nerve glia, (2) microglia and inflammation, and the (3) extracellular matrix (ECM) and retinal vasculature as key to advancing our understanding and manipulation of the retinal microenvironments. We summarize here the findings of the workshop for the broader scientific community.
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Yoo S, Blackshaw S. Regulation and function of neurogenesis in the adult mammalian hypothalamus. Prog Neurobiol 2018; 170:53-66. [PMID: 29631023 DOI: 10.1016/j.pneurobio.2018.04.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 02/20/2018] [Accepted: 04/05/2018] [Indexed: 12/11/2022]
Abstract
Over the past two decades, evidence has accumulated that neurogenesis can occur in both the juvenile and adult mammalian hypothalamus. Levels of hypothalamic neurogenesis can be regulated by dietary, environmental and hormonal signals. Since the hypothalamus has a central role in controlling a broad range of homeostatic physiological processes, these findings may have far ranging behavioral and medical implications. However, many questions in the field remain unresolved, including the cells of origin of newborn hypothalamic neurons and the extent to which these cells actually regulate hypothalamic-controlled behaviors. In this manuscript, we conduct a critical review of the literature on postnatal hypothalamic neurogenesis in mammals, lay out the main outstanding controversies in the field, and discuss how best to advance our knowledge of this fascinating but still poorly understood process.
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Affiliation(s)
- Sooyeon Yoo
- 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; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Center for Human Systems Biology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA; Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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Gu D, Wang S, Zhang S, Zhang P, Zhou G. Directed transdifferentiation of Müller glial cells to photoreceptors using the sonic hedgehog signaling pathway agonist purmorphamine. Mol Med Rep 2017; 16:7993-8002. [PMID: 28983586 PMCID: PMC5779882 DOI: 10.3892/mmr.2017.7652] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 07/28/2017] [Indexed: 01/08/2023] Open
Abstract
Specification of distinct cell types from Müller glial cells is key to the potential application of endogenous repair in retinal regeneration. Sonic hedgehog (SHH) has been established as a potent mitogen for rat Müller glial cells, which also induces Müller glial cells to dedifferentiate and adopt the phenotype of rod photoreceptors. The present study investigated the effects of purmorphamine, a small molecule that activates the SHH‑pathway, in the proliferation, dedifferentiation and transdifferentiation of Müller glial cells, as determined by several methods including immunofluorescence, polymerase chain reaction and western blotting. It was demonstrated that it may be able to replace SHH for the regeneration of retinal neurons. Purmorphamine was revealed to stimulate the proliferation of Müller glial cells by increasing the expression of cyclin D1 and cyclin D3. In addition, purmorphamine‑treated Müller glial cells were induced to dedifferentiate by inducing the expression of progenitor‑specific markers; subsequently differentiating into rod‑like photoreceptors. Intraocular injection of purmorphamine promoted the activation of Müller glial cells, and in turn, the production of rod‑like photoreceptors in acute damaged retina. These results suggested that the endogenous neurogenic capacity of retinal Müller glial cells may be enhanced by this small molecular agonist of the SHH signaling pathway.
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Affiliation(s)
- Dandan Gu
- Department of Anatomy, Histology and Embryology, Institute of Acupuncture Research, School of Basic Medical Sciences, Fudan University, Shanghai 200032, P.R. China
| | - Songtao Wang
- Department of Integrative Medicine and Neurobiology, Institute of Acupuncture Research, School of Basic Medical Sciences, Fudan University, Shanghai 200032, P.R. China
| | - Shuai Zhang
- Key Laboratory of Medical Imaging Computing and Computer Assisted Intervention of Shanghai, Fudan University, Shanghai 200032, P.R. China
| | - Peng Zhang
- Department of Integrative Medicine and Neurobiology, Institute of Acupuncture Research, School of Basic Medical Sciences, Fudan University, Shanghai 200032, P.R. China
| | - Guomin Zhou
- Department of Anatomy, Histology and Embryology, Institute of Acupuncture Research, School of Basic Medical Sciences, Fudan University, Shanghai 200032, P.R. China
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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.
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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
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Hamon A, Masson C, Bitard J, Gieser L, Roger JE, Perron M. Retinal Degeneration Triggers the Activation of YAP/TEAD in Reactive Müller Cells. Invest Ophthalmol Vis Sci 2017; 58:1941-1953. [PMID: 28384715 PMCID: PMC6024660 DOI: 10.1167/iovs.16-21366] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Purpose During retinal degeneration, Müller glia cells respond to photoreceptor loss by undergoing reactive gliosis, with both detrimental and beneficial effects. Increasing our knowledge of the complex molecular response of Müller cells to retinal degeneration is thus essential for the development of new therapeutic strategies. The purpose of this work was to identify new factors involved in Müller cell response to photoreceptor cell death. Methods Whole transcriptome sequencing was performed from wild-type and degenerating rd10 mouse retinas at P30. The changes in mRNA abundance for several differentially expressed genes were assessed by quantitative RT-PCR (RT-qPCR). Protein expression level and retinal cellular localization were determined by western blot and immunohistochemistry, respectively. Results Pathway-level analysis from whole transcriptomic data revealed the Hippo/YAP pathway as one of the main signaling pathways altered in response to photoreceptor degeneration in rd10 retinas. We found that downstream effectors of this pathway, YAP and TEAD1, are specifically expressed in Müller cells and that their expression, at both the mRNA and protein levels, is increased in rd10 reactive Müller glia after the onset of photoreceptor degeneration. The expression of Ctgf and Cyr61, two target genes of the transcriptional YAP/TEAD complex, is also upregulated following photoreceptor loss. Conclusions This work reveals for the first time that YAP and TEAD1, key downstream effectors of the Hippo pathway, are specifically expressed in Müller cells. We also uncovered a deregulation of the expression and activity of Hippo/YAP pathway components in reactive Müller cells under pathologic conditions.
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Affiliation(s)
- Annaïg Hamon
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France 2Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
| | - Christel Masson
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France 2Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
| | - Juliette Bitard
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France 2Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
| | - Linn Gieser
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Jérôme E Roger
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France 2Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
| | - Muriel Perron
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris-Sud, Université Paris-Saclay, Orsay, France 2Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
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Lin28b stimulates the reprogramming of rat Müller glia to retinal progenitors. Exp Cell Res 2017; 352:164-174. [PMID: 28189638 DOI: 10.1016/j.yexcr.2017.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/05/2017] [Accepted: 02/08/2017] [Indexed: 11/22/2022]
Abstract
In lower-order vertebrates, Müller glia exhibit characteristics of retinal progenitor cells, while in higher vertebrates, such as mammals, the regenerative capacity of Müller glia is limited. Recently, we reported that Lin28b promoted the trans-differentiation of Müller cells to rod photoreceptor and bipolar cells in the retina of retinitis pigmentosa rat model, whereas it is unclear whether Lin28b can stimulate the reprogramming of Müller glia in vitro for transplantation into a damaged retina. In the present study, Long-Evens rat Müller glia were infected with Adeno-Lin28b or Adeno-GFP. Over-expression of Lin28b in isolated rat Müller glia resulted in the suppression of GFAP expression, enhancement of cell proliferation and a significant increase of the expression of retinal progenitor markers 5 days after infection. Moreover, Lin28b caused a significant reduction of the Let-7 family of microRNAs. Following sub-retinal space transplantation, Müller glia-derived retinal progenitors improved b-wave amplification of 30d Royal College of Surgeons retinitis pigmentosa model (RCS-P+) rats, as detected by electroretinography (ERG) recordings. Taken together, these data suggest that the up-regulation of Lin28b expression facilitated the reprogramming of Müller cells toward characteristics of retinal progenitors.
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Reyes-Aguirre LI, Lamas M. Oct4 Methylation-Mediated Silencing As an Epigenetic Barrier Preventing Müller Glia Dedifferentiation in a Murine Model of Retinal Injury. Front Neurosci 2016; 10:523. [PMID: 27895551 PMCID: PMC5108807 DOI: 10.3389/fnins.2016.00523] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/28/2016] [Indexed: 11/29/2022] Open
Abstract
Müller glia (MG) is the most abundant glial type in the vertebrate retina. Among its many functions, it is capable of responding to injury by dedifferentiating, proliferating, and differentiating into every cell types lost to damage. This regenerative ability is notoriously absent in mammals. We have previously reported that cultured mammalian MG undergoes a partial dedifferentiation, but fails to fully acquire a progenitor phenotype and differentiate into neurons. This might be explained by a mnemonic mechanism comprised by epigenetic traits, such as DNA methylation. To achieve a better understanding of this epigenetic memory, we studied the expression of pluripotency-associated genes, such as Oct4, Nanog, and Lin28, which have been reported as necessary for regeneration in fish, at early times after NMDA-induced retinal injury in a mouse experimental model. We found that although Oct4 is expressed rapidly after damage (4 hpi), it is silenced at 24 hpi. This correlates with a significant decrease in the DNA methyltransferase Dnmt3b expression, which returns to basal levels at 24 hpi. By MS-PCR, we observed a decrease in Oct4 methylation levels at 4 and 12 hpi, before returning to a fully methylated state at 24 hpi. To demonstrate that these changes are restricted to MG, we separated these cells using a GLAST antibody coupled with magnetic beads. Finally, intravitreous administration of the DNA-methyltransferase inhibitor SGI-1027 induced Oct4 expression at 24 hpi in MG. Our results suggest that mammalian MG injury-induced dedifferentiation could be restricted by DNA methylation, which rapidly silences Oct4 expression, preventing multipotency acquisition.
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Affiliation(s)
- Luis I Reyes-Aguirre
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Sede Sur México, Mexico
| | - Monica Lamas
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados-Sede Sur México, Mexico
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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.
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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
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Zhang S, Mu Z, He C, Zhou M, Liu D, Zhao XF, Goldman D, Xu H. Antiviral Drug Ganciclovir Is a Potent Inhibitor of the Proliferation of Müller Glia-Derived Progenitors During Zebrafish Retinal Regeneration. Invest Ophthalmol Vis Sci 2016; 57:1991-2000. [PMID: 27096757 PMCID: PMC4849886 DOI: 10.1167/iovs.15-18669] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose The purpose of this study was to investigate the effect of the antiviral drug ganciclovir (GCV) on Müller glia dedifferentiation and proliferation and the underlying cellular and molecular mechanisms in adult zebrafish. Methods A Tg(1016tuba1a:GFP) transgenic line was generated to identify injury-induced dedifferentiation of Müller glia. Mechanical retinal damage was induced by a needle-poke injury on the back of the eyes in adult zebrafish. Phosphate-buffered saline or GCV was injected into the vitreous of the eye at the time of injury or through the cornea. The GCV clearance rate from the eye was determined by a reversed-phase HPLC method. Green fluorescent protein (GFP) and bromodeoxyuridine (BrdU) immunofluorescence were used to determine the effect of GCV on retinal regeneration. Cell apoptosis was evaluated by TUNEL staining. Microglia were labeled by vitreous injection of isolectin IB4 conjugates. Quantitative (q)PCR and Western blot analysis were used to determine gene expression in the retina. Results Ganciclovir treatment significantly reduced the number of BrdU+ Müller glia–derived progenitor cells (MGPCs) at 4 days post injury. Further analysis showed that GCV had no impact on Müller glia dedifferentiation and the initial formation of MGPCs. Our data indicate that GCV irreversibly inhibited MGPC proliferation likely through a p53-p21cip1–dependent pathway. Interestingly, unlike control cells, GCV-treated Müller glia cells were “locked” in a prolonged dedifferentiated state. Conclusions Our study uncovered a novel inhibitory effect of GCV on MGPC proliferation and suggests its potential use as a tool to uncover molecular mechanisms underlying retinal regeneration in zebrafish.
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Affiliation(s)
- Shuqiang Zhang
- Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Zhaoxia Mu
- Eye Institute, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Chunjiao He
- Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Minmin Zhou
- College of Biological Science, Nantong University, Nantong, Jiangsu Province, China
| | - Dong Liu
- Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Xiao-Feng Zhao
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States
| | - Daniel Goldman
- Molecular and Behavioral Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, United States
| | - Hui Xu
- Jiangsu Key Lab of Neuroregeneration Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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Sánchez-Farías N, Candal E. Identification of Radial Glia Progenitors in the Developing and Adult Retina of Sharks. Front Neuroanat 2016; 10:65. [PMID: 27378863 PMCID: PMC4913098 DOI: 10.3389/fnana.2016.00065] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/01/2016] [Indexed: 01/01/2023] Open
Abstract
Neural stem cells give rise to transient progenitors termed neuroepithelial cells (NECs) and radial glial cells (RGCs). RGCs represent the major source of neurons, glia and adult stem cells in several regions of the central nervous system (CNS). RGCs are mostly transient in mammals, but they are widely maintained in the adult CNS of fishes, where they continue to be morphologically similar to RGCs in the mammalian brain and fulfill similar roles as progenitors and guide for migrating neurons. The retina of fishes offers an exceptional model to approach the study of adult neurogenesis because of the presence of constitutive proliferation from the ciliary marginal zone (CMZ), containing NECs, and from adult glial cells with radial morphology (the Müller glia). However, the cellular hierarchies and precise contribution of different types of progenitors to adult neurogenesis remain unsolved. We have analyzed the transition from NECs to RGCs and RGC differentiation in the retina of the cartilaginous fish Scyliorhinus canicula, which offers a particularly good spatial and temporal frame to investigate this process. We have characterized progenitor and adult RGCs by immunohistochemical detection of glial markers as glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS). We have compared the emergence and localization of glial markers with that of proliferating cell nuclear antigen (PCNA, a proliferation maker) and Doublecortin (DCX, which increases at early stages of neuronal differentiation). During retinal development, GFAP-immunoreactive NECs located in the most peripheral CMZ (CMZp) codistribute with DCX-immunonegative cells. GFAP-immunoreactive RGCs and Müller cells are located in successive more central parts of the retina and codistribute with DCX- and DCX/GS-immunoreactive cells, respectively. The same types of progenitors are found in juveniles, suggesting that the contribution of the CMZ to adult neurogenesis implies a transition through the radial glia (RG) state.
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Affiliation(s)
- Nuria Sánchez-Farías
- Grupo BRAINSHARK, Departamento de Bioloxía Celular e Ecoloxía, Universidade de Santiago de Compostela Santiago de Compostela, Spain
| | - Eva Candal
- Grupo BRAINSHARK, Departamento de Bioloxía Celular e Ecoloxía, Universidade de Santiago de Compostela Santiago de Compostela, Spain
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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.
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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
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Sun J, Mandai M, Kamao H, Hashiguchi T, Shikamura M, Kawamata S, Sugita S, Takahashi M. Protective Effects of Human iPS-Derived Retinal Pigmented Epithelial Cells in Comparison with Human Mesenchymal Stromal Cells and Human Neural Stem Cells on the Degenerating Retina in rd1 mice. Stem Cells 2016; 33:1543-53. [PMID: 25728228 DOI: 10.1002/stem.1960] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/26/2014] [Indexed: 01/03/2023]
Abstract
Retinitis pigmentosa (RP) is a group of visual impairments characterized by progressive rod photoreceptor cell loss due to a genetic background. Pigment epithelium-derived factor (PEDF) predominantly secreted by the retinal pigmented epithelium (RPE) has been reported to protect photoreceptors in retinal degeneration models, including rd1. In addition, clinical trials are currently underway outside Japan using human mesenchymal stromal cells and human neural stem cells to protect photoreceptors in RP and dry age-related macular degeneration, respectively. Thus, this study aimed to investigate the rescue effects of induced pluripotent stem (iPS)-RPE cells in comparison with those types of cells used in clinical trials on photoreceptor degeneration in rd1 mice. Cells were injected into the subretinal space of immune-suppressed 2-week-old rd1 mice. The results demonstrated that human iPS-RPE cells significantly attenuated photoreceptor degeneration on postoperative days (PODs) 14 and 21 and survived longer up to at least 12 weeks after operation than the other two types of graft cells with less immune responses and apoptosis. The mean PEDF concentration in the intraocular fluid in RPE-transplanted eyes was more than 1 µg/ml at PODs 14 and 21, and this may have contributed to the protective effect of RPE transplantation. Our findings suggest that iPS-RPE cells serve as a competent source to delay photoreceptor degeneration through stable survival in degenerating ocular environment and by releasing neuroprotective factors such as PEDF.
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Affiliation(s)
- Jianan Sun
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology (CDB), Kobe, Japan; Application Biology and Regenerative Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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Hamon A, Roger JE, Yang XJ, Perron M. Müller glial cell-dependent regeneration of the neural retina: An overview across vertebrate model systems. Dev Dyn 2016; 245:727-38. [PMID: 26661417 PMCID: PMC4900950 DOI: 10.1002/dvdy.24375] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/12/2015] [Accepted: 11/22/2015] [Indexed: 12/21/2022] Open
Abstract
Retinal dystrophies are a major cause of blindness for which there are currently no curative treatments. Transplantation of stem cell‐derived neuronal progenitors to replace lost cells has been widely investigated as a therapeutic option. Another promising strategy would be to trigger self‐repair mechanisms in patients, through the recruitment of endogenous cells with stemness properties. Accumulating evidence in the past 15 year0s has revealed that several retinal cell types possess neurogenic potential, thus opening new avenues for regenerative medicine. Among them, Müller glial cells have been shown to be able to undergo a reprogramming process to re‐acquire a stem/progenitor state, allowing them to proliferate and generate new neurons for repair following retinal damages. Although Müller cell–dependent spontaneous regeneration is remarkable in some species such as the fish, it is extremely limited and ineffective in mammals. Understanding the cellular events and molecular mechanisms underlying Müller cell activities in species endowed with regenerative capacities could provide knowledge to unlock the restricted potential of their mammalian counterparts. In this context, the present review provides an overview of Müller cell responses to injury across vertebrate model systems and summarizes recent advances in this rapidly evolving field. Developmental Dynamics 245:727–738, 2016. © 2015 The Authors. Developmental Dynamics published by Wiley Periodicals, Inc. The present review provides an overview of Müller cell responses to injury across vertebrate model systems and summarizes recent advances in this rapidly evolving field.
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Affiliation(s)
- Annaïg Hamon
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris Sud, Université Paris-Saclay, Orsay, France.,Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
| | - Jérôme E Roger
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris Sud, Université Paris-Saclay, Orsay, France.,Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France
| | - Xian-Jie Yang
- Stein Eye Institute, University of California Los Angeles, Los Angeles, California
| | - Muriel Perron
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris Sud, Université Paris-Saclay, Orsay, France.,Centre d'Etude et de Recherche Thérapeutique en Ophtalmologie, Retina France, Orsay, France.,Stein Eye Institute, University of California Los Angeles, Los Angeles, California
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Angbohang A, Wu N, Charalambous T, Eastlake K, Lei Y, Kim YS, Sun XH, Limb GA. Downregulation of the Canonical WNT Signaling Pathway by TGFβ1 Inhibits Photoreceptor Differentiation of Adult Human Müller Glia with Stem Cell Characteristics. Stem Cells Dev 2016; 25:1-12. [PMID: 26456050 PMCID: PMC4692127 DOI: 10.1089/scd.2015.0262] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/09/2015] [Indexed: 12/29/2022] Open
Abstract
Müller glia are responsible for the retina regeneration observed in zebrafish. Although the human retina harbors Müller glia with stem cell characteristics, there is no evidence that they regenerate the retina after disease or injury. Transforming growth factor-β (TGFβ) and Wnt signaling regulate retinal neurogenesis and inflammation, but their roles in the neural differentiation of human Müller stem cells (hMSC) are not known. We examined hMSC lines in vitro for the expression of various Wnt signaling components and for their modulation by TGFβ1, as well as the effect of this cytokine on the photoreceptor differentiation of these cells. Culture of hMSC with a combination of factors that induce photoreceptor differentiation of hMSC (FGF2, taurine, retinoic acid, and insulin-like growth factor type1; FTRI), markedly upregulated the expression of components of the canonical Wnt signaling pathway, including WNT2B, DKK1, and active β-CATENIN. Although FTRI did not modify mRNA expression of WNT5B, a component of the noncanonical/planar cell polarity Wnt pathway, it upregulated its secretion. Furthermore, TGFβ1 not only decreased WNT2B expression, but also inhibited FTRI-induced photoreceptor differentiation of hMSC, as determined by expression of the photoreceptor markers NR2E3, RHODOPSIN, and RECOVERIN. Inhibition of TGFβ1 signaling by an ALK5 inhibitor prevented TGFβ1-induced changes in the expression of the two Wnt ligands examined. More importantly, inhibition of the canonical WNT signaling by XAV-939 prevented FTRI-induced photoreceptor differentiation. These observations suggest that TGFβ may play a key role in preventing neural differentiation of hMSC and may constitute a potential target for induction of endogenous regeneration of the human retina.
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Affiliation(s)
- Angshumonik Angbohang
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Na Wu
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Thalis Charalambous
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Karen Eastlake
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Yuan Lei
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yung Su Kim
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Xinghuai H. Sun
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - G. Astrid Limb
- NIHR Biomedical Research Centre for Ophthalmology at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
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Ogai K, Hisano S, Sugitani K, Koriyama Y, Kato S. Cell Fate of Müller Cells During Photoreceptor Regeneration in an N-Methyl-N-nitrosourea-Induced Retinal Degeneration Model of Zebrafish. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:685-92. [PMID: 26427476 DOI: 10.1007/978-3-319-17121-0_91] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Zebrafish can regenerate several organs such as the tail fin, heart, central nervous system, and photoreceptors. Very recently, a study has demonstrated the photoreceptor regeneration in the alkylating agent N-methyl-N-nitrosourea (MNU)-induced retinal degeneration (RD) zebrafish model, in which whole photoreceptors are lost within a week after MNU treatment and then regenerated within a month. The research has also shown massive proliferation of Müller cells within a week. To address the question of whether proliferating Müller cells are the source of regenerating photoreceptors, which remains unknown in the MNU-induced zebrafish RD model, we employed a BrdU pulse-chase technique to label the proliferating cells within a week after MNU treatment. As a result of the BrdU pulse-chase technique, a number of BrdU(+) cells were observed in the outer nuclear layer as well as the inner nuclear layer. This implies that regenerating photoreceptors are derived from proliferating Müller cells in the zebrafish MNU-induced RD model.
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Affiliation(s)
- Kazuhiro Ogai
- Wellness Promotion Science Center, Institute of Medial, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80 Kodatsuno, 920-0942, Kanazawa, Ishikawa, Japan.
| | - Suguru Hisano
- Department of Clinical Laboratory Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Ishikawa, Japan.
| | - Kayo Sugitani
- Department of Clinical Laboratory Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, 920-0942, Ishikawa, Japan.
| | - Yoshiki Koriyama
- Graduate School and Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, 3500-3 Minamitamagaki, 513-8670, Suzuka, Mie, Japan.
| | - Satoru Kato
- Department of Molecular Neurobiology, Graduate School of Medical Science, Kanazawa University, 13-1 Takaramachi, Kanazawa, 920-8640, Ishikawa, Japan.
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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.
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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
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Resveratrol Prevents Retinal Dysfunction by Regulating Glutamate Transporters, Glutamine Synthetase Expression and Activity in Diabetic Retina. Neurochem Res 2015; 41:1050-64. [DOI: 10.1007/s11064-015-1793-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 10/10/2015] [Accepted: 11/25/2015] [Indexed: 12/22/2022]
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Wilson SG, Wen W, Pillai-Kastoori L, Morris AC. Tracking the fate of her4 expressing cells in the regenerating retina using her4:Kaede zebrafish. Exp Eye Res 2015; 145:75-87. [PMID: 26616101 DOI: 10.1016/j.exer.2015.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/22/2015] [Accepted: 11/03/2015] [Indexed: 11/26/2022]
Abstract
The Basic-Helix-Loop-Helix-Orange (bHLH-O) transcription factor Hairy-related 4 (her4) is a downstream effector of Notch-Delta signaling that represses expression of typically pro-neural genes in proliferative domains of the central nervous system. Notch-Delta signaling in the retina has been shown to increase in response to injury and influences neuroprotective properties of Müller glia. In contrast to mammals, teleost fish are able to regenerate retinal neurons in response to injury. In zebrafish, her4 is upregulated in the regenerating neural retina in response to both acute and chronic photoreceptor damage, but the contribution of her4 expressing cells to neurogenesis following acute or chronic retinal damage has remained unexplored. Here we investigate the role of her4 in the regenerating retina in a background of chronic, rod-specific degeneration as well as following acute light damage. We demonstrate that her4 is expressed in the persistently neurogenic ciliary marginal zone (CMZ), as well as in small subsets of slowly proliferating Müller glia in the inner nuclear layer (INL) of the central retina. We generated a transgenic line of zebrafish that expresses the photoconvertible Kaede reporter driven by a her4 promoter and validated that expression of the transgene faithfully recapitulates endogenous her4 expression. Lineage tracing analysis revealed that her4-expressing cells in the INL contribute to the rod lineage, and her4 expressing cells in the CMZ are capable of generating any retinal cell type except rod photoreceptors. Our results indicate that her4 is involved in a replenishing pathway that maintains populations of stem cells in the central retina, and that the magnitude of the her4-associated proliferative response mirrors the extent of retinal damage.
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Affiliation(s)
- Stephen G Wilson
- Department of Biology, University of Kentucky, Lexington, 40506-0225, KY, USA
| | - Wen Wen
- Department of Biology, University of Kentucky, Lexington, 40506-0225, KY, USA
| | | | - Ann C Morris
- Department of Biology, University of Kentucky, Lexington, 40506-0225, KY, USA.
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Gallina D, Zelinka CP, Cebulla CM, Fischer AJ. Activation of glucocorticoid receptors in Müller glia is protective to retinal neurons and suppresses microglial reactivity. Exp Neurol 2015; 273:114-25. [PMID: 26272753 DOI: 10.1016/j.expneurol.2015.08.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/05/2015] [Accepted: 08/08/2015] [Indexed: 01/06/2023]
Abstract
Reactive microglia and macrophages are prevalent in damaged retinas. Glucocorticoid signaling is known to suppress inflammation and the reactivity of microglia and macrophages. In the vertebrate retina, the glucocorticoid receptor (GCR) is known to be activated and localized to the nuclei of Müller glia (Gallina et al., 2014). Accordingly, we investigated how signaling through GCR influences the survival of neurons using the chick retina in vivo as a model system. We applied intraocular injections of GCR agonist or antagonist, assessed microglial reactivity, and the survival of retinal neurons following different damage paradigms. Microglial reactivity was increased in retinas from eyes that were injected with vehicle, and this reactivity was decreased by GCR-agonist dexamethasone (Dex) and increased by GCR-antagonist RU486. We found that activation of GCR suppresses the reactivity of microglia and inhibited the loss of retinal neurons resulting from excitotoxicity. We provide evidence that the protection-promoting effects of Dex were maintained when the microglia were selectively ablated. Similarly, intraocular injections of Dex protected ganglion cells from colchicine-treatment and protected photoreceptors from damage caused by retinal detachment. We conclude that activation of GCR promotes the survival of ganglion cells in colchicine-damaged retinas, promotes the survival of amacrine and bipolar cells in excitotoxin-damaged retinas, and promotes the survival of photoreceptors in detached retinas. We propose that suppression of microglial reactivity is secondary to activation of GCR in Müller glia, and this mode of signaling is an effective means to lessen the damage and vision loss resulting from different types of retinal damage.
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Affiliation(s)
- Donika Gallina
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave., Columbus, OH 43210-1239, USA
| | - Christopher Paul Zelinka
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave., Columbus, OH 43210-1239, USA
| | - Colleen M Cebulla
- Havener Eye Institute, Department of Ophthalmology and Visual Science, College of Medicine, The Ohio State University, 915 Olentangy River Road, Suite 5000, Columbus, OH 43212, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, Wexner Medical Center, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave., Columbus, OH 43210-1239, USA.
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Zhu J, Lamba DA. Restoring Vision: Where are We with Stem Cells? CURRENT OPHTHALMOLOGY REPORTS 2015. [DOI: 10.1007/s40135-015-0078-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Stenkamp DL. Development of the Vertebrate Eye and Retina. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:397-414. [PMID: 26310167 DOI: 10.1016/bs.pmbts.2015.06.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The mature, functional, and healthy eye is generated by the coordinated regulatory interaction of numerous and diverse developing tissues. The neural retina of the eye must undergo the neurogenesis of multiple retinal cell types in the correct ratios and spatial patterns. This chapter provides an overview of retinal development, and includes a summary of the process of eye organogenesis, a discussion of major principles of retinal neurogenesis, and describes some of the key molecular factors critical for retinal development. Defects in many of these factors underlie diseases of the eye, and an understanding of the process of retinal development will be critical for successful future applications of regenerative therapies for eye disease.
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Affiliation(s)
- Deborah L Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA.
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Todd L, Fischer AJ. Hedgehog signaling stimulates the formation of proliferating Müller glia-derived progenitor cells in the chick retina. Development 2015; 142:2610-22. [PMID: 26116667 DOI: 10.1242/dev.121616] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 06/15/2015] [Indexed: 12/29/2022]
Abstract
Müller glia can be stimulated to de-differentiate and become proliferating progenitor cells that regenerate neurons in the retina. The signaling pathways that regulate the formation of proliferating Müller glia-derived progenitor cells (MGPCs) are beginning to be revealed. The purpose of this study was to investigate whether Hedgehog (Hh) signaling influences the formation of MGPCs in the chick retina. We find that Hh signaling is increased in damaged retinas where MGPCs are known to form. Sonic Hedgehog (Shh) is normally present in the axons of ganglion cells, but becomes associated with Müller glia and MGPCs following retinal damage. Activation of Hh signaling with recombinant human SHH (rhShh) or smoothened agonist (SAG) increased levels of Ptch1, Gli1, Gli2, Gli3, Hes1 and Hes5, and stimulated the formation of proliferating MGPCs in damaged retinas. In undamaged retinas, SAG or rhShh had no apparent effect upon the Müller glia. However, SAG combined with FGF2 potentiated the formation of MGPCs, whereas SAG combined with IGF1 stimulated the nuclear migration of Müller glia, but not the formation of MGPCs. Conversely, inhibition of Hh signaling with KAAD-cyclopamine, Gli antagonists or antibody to Shh reduced numbers of proliferating MGPCs in damaged and FGF2-treated retinas. Hh signaling potentiates Pax6, Klf4 and cFos expression in Müller glia during the formation of MGPCs. We find that FGF2/MAPK signaling recruits Hh signaling into the signaling network that drives the formation of proliferating MGPCs. Our findings implicate Hh signaling as a key component of the network of signaling pathways that promote the de-differentiation of Müller glia and proliferation of MGPCs.
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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
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 4190 Graves Hall, 333 West 10th Ave, Columbus, OH 43210, USA
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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.
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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
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Vecino E, Rodriguez FD, Ruzafa N, Pereiro X, Sharma SC. Glia-neuron interactions in the mammalian retina. Prog Retin Eye Res 2015; 51:1-40. [PMID: 26113209 DOI: 10.1016/j.preteyeres.2015.06.003] [Citation(s) in RCA: 493] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/18/2015] [Accepted: 06/02/2015] [Indexed: 02/07/2023]
Abstract
The mammalian retina provides an excellent opportunity to study glia-neuron interactions and the interactions of glia with blood vessels. Three main types of glial cells are found in the mammalian retina that serve to maintain retinal homeostasis: astrocytes, Müller cells and resident microglia. Müller cells, astrocytes and microglia not only provide structural support but they are also involved in metabolism, the phagocytosis of neuronal debris, the release of certain transmitters and trophic factors and K(+) uptake. Astrocytes are mostly located in the nerve fibre layer and they accompany the blood vessels in the inner nuclear layer. Indeed, like Müller cells, astrocytic processes cover the blood vessels forming the retinal blood barrier and they fulfil a significant role in ion homeostasis. Among other activities, microglia can be stimulated to fulfil a macrophage function, as well as to interact with other glial cells and neurons by secreting growth factors. This review summarizes the main functional relationships between retinal glial cells and neurons, presenting a general picture of the retina recently modified based on experimental observations. The preferential involvement of the distinct glia cells in terms of the activity in the retina is discussed, for example, while Müller cells may serve as progenitors of retinal neurons, astrocytes and microglia are responsible for synaptic pruning. Since different types of glia participate together in certain activities in the retina, it is imperative to explore the order of redundancy and to explore the heterogeneity among these cells. Recent studies revealed the association of glia cell heterogeneity with specific functions. Finally, the neuroprotective effects of glia on photoreceptors and ganglion cells under normal and adverse conditions will also be explored.
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Affiliation(s)
- Elena Vecino
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - F David Rodriguez
- Department of Biochemistry and Molecular Biology, E-37007, University of Salamanca, Salamanca, Spain
| | - Noelia Ruzafa
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - Xandra Pereiro
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - Sansar C Sharma
- Department of Ophthalmology, Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10595, USA; IKERBASQUE, Basque Foundation for Science at Dept. Cell Biology and Histology, UPV/EHU, Spain
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Acute retinal injury and the relationship between nerve growth factor, Notch1 transcription and short-lived dedifferentiation transient changes of mammalian Müller cells. Vision Res 2015; 110:107-17. [PMID: 25817714 DOI: 10.1016/j.visres.2015.01.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 01/10/2015] [Accepted: 01/23/2015] [Indexed: 11/22/2022]
Abstract
Our aim is to define related molecular events on how dormant Müller glia cells re-enter the cell cycle, proliferate and produce new retinal neurons from initial injury to glial scar formation. Sodium iodate (NaIO3) was used to induce acute retinal injury. Long-Evans rats were administered with NaIO3 or phosphate-buffered saline by intraperitoneal injection. The proliferation, dedifferentiation and neurogenesis of Müller cells were analyzed by double-labeled fluorescence immunohistochemistry with primary antibodies - against Müller cells and specific cell markers. Possible molecules that limit the regenerative potential of Müller cells were also determined by immunofluorescence staining, quantitative RT-PCR, protein array, ELISA and Western blot. In the first 3-7days after NaIO3 administration, Müller cells were activated and underwent a fate switch, including transient proliferation, dedifferentiation and neurogenesis. Nerve growth factor (NGF) signaling concomitantly increased with the downregulation of p27(Kip1) in Müller cells, which may promote Müller cells to re-enter the cell cycle. The transient increase of NGF signaling and the transient decrease of Notch signaling inhibited Hes1, which might enhance the neuronal differentiation of dedifferentiated Müller cells and suppress gliosis. Upregulated Notch and decreased NGF expressions limit dedifferentiation and neurogenesis, but induces retinal Müller cell gliosis at a later stage. We conclude that transient NGF upregulation and Notch1 downregulation may activate the transient proliferation, dedifferentiation and neurogenesis of Müller cells during NaIO3-induced acute retinal injury; which could be a therapeutic target for overcoming Müller cell gliosis. Such therapy could be potentially used for treating retinal-related diseases.
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48
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Jian Q, Li Y, Yin ZQ. Rat BMSCs initiate retinal endogenous repair through NGF/TrkA signaling. Exp Eye Res 2015; 132:34-47. [PMID: 25584870 DOI: 10.1016/j.exer.2015.01.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 12/16/2014] [Accepted: 01/09/2015] [Indexed: 12/18/2022]
Abstract
Müller cells can completely repair retinal injury by acting as endogenous stem/progenitor cells in lower-order vertebrates. However, a safe and effective approach to activate progenitor potential of retinal Müller cells in higher-order vertebrates, which rarely re-enter the cell cycle, is a bottleneck problem. In the present study, Royal College of Surgeon's (RCS) rats were subjected to rat bone marrow mesenchymal stem cells (rBMSCs) subretinal space transplantation. Electroretinography (ERG) recordings showed that the b-wave amplitudes and ONL thicknesses statistically increased after transplantation. The number of Müller cells expressing proliferative, stem/progenitor and neuronal markers significantly increased after rBMSCs transplantation in vivo or after co-culturing with rBMSCs in vitro. The cultured rBMSCs could secrete nerve growth factor (NGF). In addition, we confirmed that NGF or NGF-neutralizing antibody could activate or depress Müller cells dedifferentiation, both in vivo and in vitro. Furthermore, Müller cells expressing high levels of the NGF receptor neurotrophic tyrosine kinase receptor type 1 (TrkA) were observed in the retinas of rats transplanted with rBMSCs. Moreover, the protein expression of downstream elements of NGF/TrkA signaling, such as p-PI3K, p-Akt and p-CREB, increased in Müller cells in the retinas of rBMSCs-treated rats in vivo or in Müller cells co-cultured with rBMSCs in vitro. Blocking TrkA with K-252a reduced the number of dedifferentiated Müller cells and the expression of NGF/TrkA signaling in vitro. Thus, rBMSCs might initiate endogenous regenerative mechanisms, which may constitute a new therapeutic strategy for retinal dystrophic diseases.
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Affiliation(s)
- Qian Jian
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Yaochen Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.
| | - Zheng Qin Yin
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.
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Chapter 5 - Restoring Vision to the Blind: Endogenous Regeneration. Transl Vis Sci Technol 2014; 3:7. [DOI: 10.1167/tvst.3.7.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 11/24/2022] Open
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Fischer AJ, Zelinka C, Milani-Nejad N. Reactive retinal microglia, neuronal survival, and the formation of retinal folds and detachments. Glia 2014; 63:313-27. [PMID: 25231952 DOI: 10.1002/glia.22752] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/02/2014] [Indexed: 01/01/2023]
Abstract
Reactive microglia and macrophages are prevalent in damaged retinas. Accordingly, we investigate how the activation or ablation of microglia/macrophages influences the survival of neurons in the chick retina in vivo. We applied intraocular injections of interleukin 6 (IL6) to stimulate the reactivity of microglia/macrophages and clodronate-liposomes to ablate microglia/macrophages. Activation of the microglia/macrophages with IL6 delays the death of retinal neurons from N-methyl-D-aspartate (NMDA) -induced excitotoxicity. In addition, activation of microglia/macrophages combined with colchicine-mediated retinal damage diminished the survival of ganglion cells. Application of IL6 after an excitotoxic insult greatly exacerbates the damage, and causes widespread retinal detachments and folds, accompanied by accumulation of microglia/macrophages in the subretinal space. Damage-induced retinal folds and detachments were significantly reduced by the ablation of microglia/macrophages. We conclude that microglial reactivity is detrimental to the survival of ganglion cells in colchicine-damaged retinas and detrimental to the survival of photoreceptors in retinal folds. In addition, we conclude that IL6-treatment transiently protects amacrine and bipolar cells against an excitotoxic insult. We propose that suppressing reactivity of microglia/macrophages may be an effective means to lessen the damage and vision loss resulting from damage, in particular during retinal detachment injuries.
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Affiliation(s)
- Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, Ohio
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