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Progress of iPS cell-based transplantation therapy for retinal diseases. Jpn J Ophthalmol 2023; 67:119-128. [PMID: 36626080 DOI: 10.1007/s10384-022-00974-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/18/2022] [Indexed: 01/11/2023]
Abstract
The discovery of induced Pluripotent Stem) (iPS) cells has instigated innovation in various fields, including ophthalmology. Cell therapy has shown tremendous progress in translational research on retinal diseases, including the first-in-human transplantation of autologous iPS cell-derived retinal pigment epithelium (RPE) cells for patients with age-related macular degeneration (AMD). Cell therapy for retinitis pigmentosa (RP) has also been developed. Retinal organoid and photoreceptor cell transplantation has been shown to incorporate into the degenerated host retina, forming synapses with host neurons and resulting in functional recovery. Based on preclinical data, first-in-human transplantation of iPS cell-derived retinal sheets has been conducted. In this review, we summarize the current progress in iPS cell-based retinal cell transplantation research for retinal diseases, addressing some remaining challenges and future prospects.
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Chang YH, Kumar VB, Wen YT, Huang CY, Tsai RK, Ding DC. Induction of Human Umbilical Mesenchymal Stem Cell Differentiation Into Retinal Pigment Epithelial Cells Using a Transwell-Based Co-culture System. Cell Transplant 2022; 31:9636897221085901. [PMID: 35321565 PMCID: PMC8961389 DOI: 10.1177/09636897221085901] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
There is an increasing interest in generating retinal pigment epithelial (RPE)
cells from stem cells for treating degenerative eye diseases. However, whether
human umbilical cord mesenchymal stem cells (HUCMSCs) can differentiate into
RPE-like cells in a co-culture system has not been fully understood. In this
study, induction of HUCMSC differentiation into RPE-like cells was performed by
co-culturing HUCMSCs and a human RPE-like cell line (ARPE19) in a transwell
system and then analyzed for biomarkers using quantitative reverse transcription
polymerase chain reaction (RT-PCR) and immunofluorescence staining technique.
Moreover, the functional characterization of induced cells was carried out by
examining their phagocytic and neurotrophic factor–secreting activities. Our
results showed that mRNA expressions of RPE-specific markers—MITF, OTX2, RPE65,
PEDF, PME17, and CRALBP—and protein markers—RPE65, CRALBP, and ZO-1—were
significantly increased in HUCMSC-derived RPE-like cells. Functional
characteristic studies showed that these induced cells were capable of engulfing
photoreceptor outer segments and secreting brain-derived neurotrophic factor
(BDNF) and glial-derived neurotrophic factor (GDNF), which are typical functions
of RPE-like cells. Overall, the study findings indicate that the morphology and
proliferation of HUCMSCs can be maintained in a serum-free medium, and
differentiation into RPE-like cells can be induced by simply co-culturing
HUCMSCs with ARPE19 cells. Thus, the study provides fundamental information
regarding the clinical-scale generation of RPE-like cells from HUCMSCs.
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Affiliation(s)
- Yu-Hsun Chang
- Department of Pediatrics, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Foundation and Tzu Chi University, Hualien
| | - V Bharath Kumar
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung
| | - Yao-Tseng Wen
- Department of Ophthalmology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Foundation and Tzu Chi University, Hualien
| | - Chih-Yang Huang
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung.,Department of Chinese Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien.,Graduate Institute of Biomedical Sciences, China Medical University, Taichung.,Center of General Education, Buddhist Tzu Chi Medical Foundation, Tzu Chi University of Science and Technology, Hualien.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung
| | - Rong-Kung Tsai
- Department of Ophthalmology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Foundation and Tzu Chi University, Hualien
| | - Dah-Ching Ding
- Department of Obstetrics and Gynecology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Foundation and Tzu Chi University, Hualien.,Institute of Medical Sciences, Tzu Chi University, Hualien
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3
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Cell Ferroptosis: New Mechanism and New Hope for Retinitis Pigmentosa. Cells 2021; 10:cells10082153. [PMID: 34440922 PMCID: PMC8393369 DOI: 10.3390/cells10082153] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 12/13/2022] Open
Abstract
Retinitis pigmentosa (RP) is a leading cause of inherited retinal degeneration, with more than 60 gene mutations. Despite the genetic heterogenicity, photoreceptor cell damage remains the hallmark of RP pathology. As a result, RP patients usually suffer from reduced night vision, loss of peripheral vision, decreased visual acuity, and impaired color perception. Although photoreceptor cell death is the primary outcome of RP, the underlying mechanisms are not completely elucidated. Ferroptosis is a novel programmed cell death, with characteristic iron overload and lipid peroxidation. Recent studies, using in vitro and in vivo RP models, discovered the involvement of ferroptosis-associated cell death, suggesting a possible new mechanism for RP pathogenesis. In this review, we discuss the association between ferroptosis and photoreceptor cell damage, and its implication in the pathogenesis of RP. We propose that ferroptotic cell death not only opens up a new research area in RP, but may also serve as a novel therapeutic target for RP.
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4
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Erythropoietin Gene Therapy Delays Retinal Degeneration Resulting from Oxidative Stress in the Retinal Pigment Epithelium. Antioxidants (Basel) 2021; 10:antiox10060842. [PMID: 34070383 PMCID: PMC8229633 DOI: 10.3390/antiox10060842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/19/2021] [Accepted: 05/23/2021] [Indexed: 02/08/2023] Open
Abstract
Erythropoietin (EPO) plays an important role in erythropoiesis by its action in blocking apoptosis of progenitor cells and protects both photoreceptors and retinal ganglion cells from induced or inherited degeneration. A modified form of EPO, EPO-R76E has attenuated erythropoietic activity but is effective in inhibiting apoptosis, oxidative stress, and inflammation in several models of retinal degeneration. In this study, we used recombinant Adeno Associated Virus (AAV) to provide long-term sustained delivery of EPO-R76E and demonstrated its effects in a mouse model of dry-AMD in which retinal degeneration is induced by oxidative stress in the retinal pigment epithelial (RPE) cells. Experimental vector AAV-EPO-R76E and control vector AAV-GFP were packaged into serotype-1 (AAV1) to enable RPE selective expression. RPE oxidative stress-mediated retinal degeneration was induced by exon specific deletion of the protective enzyme MnSOD (encoded by Sod2) by cre/lox mechanism. Experimental mice received subretinal injection of AAV-EPO-R76E in the right eye and AAV-GFP in the left eye. Western blotting of RPE/choroid protein samples from AAV-EPO-R76E injected eyes showed RPE specific EPO expression. Retinal function was monitored by electroretinography (ERG). EPO-R76E over-expression in RPE delayed the retinal degeneration as measured by light microscopy in RPE specific Sod2 knockout mice. Delivery of EPO-R76E vector can be used as a tool to prevent retinal degeneration induced by RPE oxidative stress, which is implicated as a potential cause of Age-Related Macular Degeneration.
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5
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Daly C, Ward R, Reynolds AL, Galvin O, Collery RF, Kennedy BN. Brain-Derived Neurotrophic Factor as a Treatment Option for Retinal Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1074:465-471. [PMID: 29721977 DOI: 10.1007/978-3-319-75402-4_57] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
This review discusses the therapeutic potential of brain-derived neurotrophic factor (BDNF) for retinal degeneration. BDNF, nerve growth factor (NGF), neurotrophin 3 (NT-3) and NT-4/NT-5 belong to the neurotrophin family. These neuronal modulators activate a common receptor and a specific tropomyosin-related kinase (Trk) receptor. BDNF was identified as a photoreceptor protectant in models of retinal degeneration as early as 1992. However, development of effective therapeutics that exploit this pathway has been difficult due to challenges in sustaining therapeutic levels in the retina.
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Affiliation(s)
- Conor Daly
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Ireland
| | - Rebecca Ward
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Ireland
| | - Alison L Reynolds
- School of Veterinary Medicine, University College Dublin, Belfield, Ireland
| | - Orla Galvin
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Ireland.,RenaSci Limited, BioCity, Nottingham, UK
| | - Ross F Collery
- Department of Ophthalmology and Visual Sciences, Eye Institute, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Breandán N Kennedy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Ireland.
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6
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Eve DJ, Sanberg PR. Article Commentary: Regenerative Medicine: An Analysis of Cell Transplantation's Impact. Cell Transplant 2017; 16:751-764. [DOI: 10.3727/000000007783465136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- David J. Eve
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Paul R. Sanberg
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida College of Medicine, Tampa, FL 33612, USA
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7
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SanMartin A, Borlongan CV. Article Commentary: Cell Transplantation: Toward Cell Therapy. Cell Transplant 2017; 15:665-73. [PMID: 17176618 DOI: 10.3727/000000006783981666] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Agneta SanMartin
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery, University of South Florida, Tampa, FL 33612, USA.
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8
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Combined transplantation of human mesenchymal stem cells and human retinal progenitor cells into the subretinal space of RCS rats. Sci Rep 2017; 7:199. [PMID: 28298640 PMCID: PMC5428026 DOI: 10.1038/s41598-017-00241-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/15/2017] [Indexed: 11/08/2022] Open
Abstract
Retinitis pigmentosa (RP) is one of hereditary retinal diseases characterized by the loss of photoreceptors. Cell transplantation has been clinically applied to treat RP patients. Human retinal progenitor cells (HRPCs) and human bone marrow-derived mesenchymal stem cells (HBMSCs) are the two commonly and practically used stem cells for transplantation. Since combined transplantation could be a promising way to integrate the advantages of both stem cell types, we transplanted HRPCs and HBMSCs into the subretinal space (SRS) of Royal College of Surgeons (RCS) rats. We report that HRPCs/HBMSCs combined transplantation maintains the electroretinogram results much better than HRPCs or HBMSCs single transplantations. The thickness of outer nuclear layer also presented a better outcome in the combined transplantation. Importantly, grafted cells in the combination migrated better, both longitudinally and latitudinally, than single transplantation. The photoreceptor differentiation of grafted cells in the retina of RCS rats receiving combined transplantation also showed a higher ratio than single transplantation. Finally, activation of microglia and the gliosis of Müller cells were more effectively suppressed in combined transplantation, indicating better immunomodulatory and anti-gliosis effects. Taken together, combining the transplantation of HRPCs and HBMSCs is a more effective strategy in stem cell-based therapy for retinal degenerative diseases.
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9
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Suzuki J, Nagai N, Nishizawa M, Abe T, Kaji H. Electrochemical manipulation of cell populations supported by biodegradable polymeric nanosheets for cell transplantation therapy. Biomater Sci 2017; 5:216-222. [DOI: 10.1039/c6bm00852f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The on-demand harvesting of cell/nanosheet constructs and their subsequent transplantation in a minimally-invasive manner are described.
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Affiliation(s)
- Jin Suzuki
- Department of Finemechanics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
| | - Nobuhiro Nagai
- Division of Clinical Cell Therapy
- United Centers for Advanced Research and Translational Medicine (ART)
- Tohoku University Graduate School of Medicine
- Sendai 980-8575
- Japan
| | - Matsuhiko Nishizawa
- Department of Finemechanics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
| | - Toshiaki Abe
- Division of Clinical Cell Therapy
- United Centers for Advanced Research and Translational Medicine (ART)
- Tohoku University Graduate School of Medicine
- Sendai 980-8575
- Japan
| | - Hirokazu Kaji
- Department of Finemechanics
- Graduate School of Engineering
- Tohoku University
- Sendai 980-8579
- Japan
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10
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Afarid M, Torabi-Nami M, Zare B. Neuroprotective and restorative effects of the brain-derived neurotrophic factor in retinal diseases. J Neurol Sci 2016; 363:43-50. [PMID: 27000219 DOI: 10.1016/j.jns.2016.02.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 01/16/2016] [Accepted: 02/10/2016] [Indexed: 01/18/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin proposed to be implicated in ameliorating the course of some neurodegenerative disorders. Given the fact that retina is considered as an out-pouching of the central nervous system, its related diseases have long been suggested to receive protective influence from this signaling molecule. The role of BDNF in retinal neurorestoration, neuroprotection and oxidative stress has extensively been tested over the past two decades. Nonetheless, almost the entire related literature root in animal studies and clinical research on this topic is lacking. Although much of the evidence have validated the protective properties of BDNF against various retinal cell diseases, bringing such insights into clinical context would depend on further well-designed research. The present review is an attempt to categorize and discuss the available evidence with regard to the BDNF and retinal diseases.
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Affiliation(s)
- Mehrdad Afarid
- Department of Ophthalmology, Poostchi Eye Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Torabi-Nami
- Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran; Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Bijan Zare
- Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
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11
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Fujie T, Mori Y, Ito S, Nishizawa M, Bae H, Nagai N, Onami H, Abe T, Khademhosseini A, Kaji H. Micropatterned polymeric nanosheets for local delivery of an engineered epithelial monolayer. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:1699-1705. [PMID: 24307219 DOI: 10.1002/adma.201304183] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 09/17/2013] [Indexed: 05/28/2023]
Abstract
Like a carpet for cells, micropatterned polymeric nanosheets are developed toward local cell delivery. The nanosheets direct morphogenesis of retinal pigment epithelial (RPE) cells and allow for the injection of an engineered RPE monolayer through syringe needles without the loss of cell viability. Such an ultrathin carrier has the promise of a minimally invasive delivery of cells into narrow tissue spaces.
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Affiliation(s)
- Toshinori Fujie
- WPI-Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan; Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480, Japan
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12
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Trophic factors in the pathogenesis and therapy for retinal degenerative diseases. Surv Ophthalmol 2014; 59:134-65. [PMID: 24417953 DOI: 10.1016/j.survophthal.2013.09.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 12/27/2022]
Abstract
Trophic factors are endogenously secreted proteins that act in an autocrine and/or paracrine fashion to affect vital cellular processes such as proliferation, differentiation, and regeneration, thereby maintaining overall cell homeostasis. In the eye, the major contributors of these molecules are the retinal pigment epithelial (RPE) and Müller cells. The primary paracrine targets of these secreted proteins include the photoreceptors and choriocapillaris. Retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa are characterized by aberrant function and/or eventual death of RPE cells, photoreceptors, choriocapillaris, and other retinal cells. We discuss results of in vitro and in vivo animal studies in which candidate trophic factors, either singly or in combination, were used in an attempt to ameliorate photoreceptor and/or retinal degeneration. We also examine current trophic factor therapies as they relate to the treatment of retinal degenerative diseases in clinical studies.
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13
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Sánchez-Ramos C, Bonnin-Arias C, Guerrera MC, Calavia MG, Chamorro E, Montalbano G, López-Velasco S, López-Muñiz A, Germanà A, Vega JA. Light regulates the expression of the BDNF/TrkB system in the adult zebrafish retina. Microsc Res Tech 2012; 76:42-9. [PMID: 23070877 DOI: 10.1002/jemt.22133] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 09/12/2012] [Indexed: 12/21/2022]
Abstract
The retina of the adult zebrafish express brain-derived neurotrophic factor (BDNF) and its signaling receptor TrkB. This functional system is involved in the biology of the vertebrate retina and its expression is regulated by light. This study was designed to investigate the effects of cyclic (12 h light/12 h darkness) or continuous (24 h) exposure during 10 days to white light, white-blue light, and blue light, as well as of darkness, on the expression of BDNF and TrkB in the retina. BDNF and TrkB were assessed in the retina of adult zebrafish using quantitative real-time polymerase chain reaction and immunohistochemistry. Exposure to white, white-blue, and blue light causes a decrease of BDNF mRNA and of BDNF immunostaining, independently of the pattern of light exposition. Conversely, in the same experimental conditions, the expression of TrkB mRNA was upregulated and TrkB immunostaining increased. Exposition to darkness diminished BDNF and TrkB mRNAs, and abolished the immunostaining for BDNF but not modified that for TrkB. These results demonstrate the regulation of BDNF and TrkB by light in the retina of adult zebrafish and might contribute to explain some aspects of the complex pathophysiology of light-induced retinopathies.
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Affiliation(s)
- C Sánchez-Ramos
- Departamento de Óptica II (Optometría y Visión), Universidad Complutense de Madrid, Madrid, Spain
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14
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Lee JK, Kim HY, Cho HK. Retinal Changes in White Rabbits after Exposure to the Light of an Operating Microscope. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2011. [DOI: 10.3341/jkos.2011.52.5.603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jeong Kyu Lee
- Department of Ophthalmology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Ho Young Kim
- Department of Ophthalmology, Chung-Ang University College of Medicine, Seoul, Korea
| | - Ho Kyun Cho
- Department of Ophthalmology, Chung-Ang University College of Medicine, Seoul, Korea
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15
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Saito T, Abe T, Wakusawa R, Sato H, Asai H, Tokita-Ishikawa Y, Nishida K. TrkB-T1 Receptors on Muller Cells Play Critical Role in Brain-Derived Neurotrophic Factor-Mediated Photoreceptor Protection against Phototoxicity. Curr Eye Res 2009; 34:580-8. [DOI: 10.1080/02713680902972358] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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German OL, Buzzi E, Rotstein NP, Rodríguez-Boulan E, Politi LE. Retinal pigment epithelial cells promote spatial reorganization and differentiation of retina photoreceptors. J Neurosci Res 2009; 86:3503-14. [PMID: 18709656 DOI: 10.1002/jnr.21813] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Retina differentiation involves the acquisition of a precise layered arrangement, with RPE cells in the first layer in intimate contact with photoreceptors in the second layer. Here, we developed an in vitro coculture model, to test the hypothesis that RPE cells play a pivotal role in organizing the spatial structure of the retina. We cocultured rat retinal neurons with ARPE-19 epithelial cells under various experimental conditions. Strikingly, when seeded over RPE cells, photoreceptors attached to their apical surfaces and proceeded with their development, including the increased synthesis of rhodopsin. Conversely, when we seeded RPE cells over neurons, the RPE cells rapidly detached photoreceptors from their substrata and positioned themselves underneath, thus restoring the normal in vivo arrangement. Treatment with the metalloproteinase inhibitor TIMP-1 blocked this reorganization, suggesting the involvement of metalloproteinases in this process. Reorganization was highly selective for photoreceptors because 98% of photoreceptors but very few amacrine neurons were found to redistribute on top of RPE cells. Interestingly, RPE cells were much more efficient than other epithelial or nonepithelial cells in promoting this reorganization. RPE cells also promoted the growth of photoreceptor axons away from them. An additional factor that contributed to the distal arrangement of photoreceptor axons was the migration of photoreceptor cell bodies along their own neurites toward the RPE cells. Our results demonstrate that RPE and photoreceptor cells interact in vitro in very specific ways. They also show that in vitro studies may provide important insights into the process of pattern formation in the retina.
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Affiliation(s)
- Olga L German
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) and Universidad Nacional del Sur, Bahía Blanca, Buenos Aires, Argentina
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17
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Asai N, Abe T, Saito T, Sato H, Ishiguro SI, Nishida K. Temporal and spatial differences in expression of TrkB isoforms in rat retina during constant light exposure. Exp Eye Res 2007; 85:346-55. [PMID: 17640634 DOI: 10.1016/j.exer.2007.05.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 05/12/2007] [Accepted: 05/30/2007] [Indexed: 12/09/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) has been reported to rescue neuroretinal cells under different toxic conditions. These cells include not only those expressing BDNF receptors (TrkB) but also those not expressing TrkB including photoreceptors. The purpose of this study was to determine the retinal sites at which BDNF and TrkB isoforms are expressed after different durations of continuous light exposure, and to compare these sites with those of TUNEL-positive cells in the same retina. Sprague-Dawley rats were exposed to continuous light for different durations. The expressions of BDNF and TrkB isoforms, TrkB-FL and TrkB-T1, were determined by Western blot analysis, real-time PCR, immunohistochemistry, and in situ hybridization before and after the light exposure. The number of TUNEL-positive cells reached a maximum at 48 to 72h after light exposure. The degree of up-regulation of the TrkB-T1 gene was significantly higher than that in normal control eyes at 24h by real-time PCR. Immunohistochemistry showed that TrkB-FL-positive cells were detected in all retinal layers except the outer nuclear layer (ONL), photoreceptor cells, and retinal pigment epithelium (RPE). The number of TrkB-FL-positive cells in the IPL was transiently decreased at 6h, and was increased on the processes of the Mueller cells in the ONL after 48h. TrkB-T1 was expressed in the INL, OPL, and RPE, and was up-regulated on the soma of Mueller cells after 24h. In situ hybridization showed that the expression of the TrkB-FL gene was up-regulated in the INL after 48h when the number of TUNEL-positive cells was at its peak. The TrkB-T1 gene was up-regulated before or just prior to the appearance of TUNEL-positive cells. These results suggest that BDNF transduces the signals using appropriate receptor isoforms that are expressed temporally and spatially differentially on Mueller cells during light-induced retinal degeneration.
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Affiliation(s)
- Nobuharu Asai
- Division of Clinical Cell Therapy, Center for Translational and Advanced Animal Research, Tohoku University, Graduate School of Medicine, 1-1 Seiryoumachi, Aobaku, Sendai, Miyagi 980-8574, Japan
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18
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da Cruz L, Chen FK, Ahmado A, Greenwood J, Coffey P. RPE transplantation and its role in retinal disease. Prog Retin Eye Res 2007; 26:598-635. [PMID: 17920328 DOI: 10.1016/j.preteyeres.2007.07.001] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Retinal pigment epithelial (RPE) transplantation aims to restore the subretinal anatomy and re-establish the critical interaction between the RPE and the photoreceptor, which is fundamental to sight. The field has developed over the past 20 years with advances coming from a large body of animal work and more recently a considerable number of human trials. Enormous progress has been made with the potential for at least partial restoration of visual function in both animal and human clinical work. Diseases that have been treated with RPE transplantation demonstrating partial reversal of vision loss include primary RPE dystrophies such as the merTK dystrophy in the Royal College of Surgeons (RCS) rat and in humans, photoreceptor dystrophies as well as complex retinal diseases such as atrophic and neovascular age-related macular degeneration (AMD). Unfortunately, in the human trials the visual recovery has been limited at best and full visual recovery has not been demonstrated. Autologous full-thickness transplants have been used most commonly and effectively in human disease but the search for a cell source to replace autologous RPE such as embryonic stem cells, marrow-derived stem cells, umbilical cord-derived cells as well as immortalised cell lines continues. The combination of cell transplantation with other modalities of treatment such as gene transfer remains an exciting future prospect. RPE transplantation has already been shown to be capable of restoring the subretinal anatomy and improving photoreceptor function in a variety of retinal diseases. In the near future, refinements of current techniques are likely to allow RPE transplantation to enter the mainstream of retinal therapy at a time when the treatment of previously blinding retinal diseases is finally becoming a reality.
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Affiliation(s)
- Lyndon da Cruz
- Division of Cellular Therapy, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK.
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