101
|
Cho MS, Kim SJ, Ku SY, Park JH, Lee H, Yoo DH, Park UC, Song SA, Choi YM, Yu HG. Generation of retinal pigment epithelial cells from human embryonic stem cell-derived spherical neural masses. Stem Cell Res 2012; 9:101-9. [DOI: 10.1016/j.scr.2012.05.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 04/06/2012] [Accepted: 05/08/2012] [Indexed: 10/28/2022] Open
|
102
|
Sahni JN, Angi M, Irigoyen C, Semeraro F, Romano MR, Parmeggiani F. Therapeutic challenges to retinitis pigmentosa: from neuroprotection to gene therapy. Curr Genomics 2012; 12:276-84. [PMID: 22131873 PMCID: PMC3131735 DOI: 10.2174/138920211795860062] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 04/08/2011] [Accepted: 04/18/2011] [Indexed: 12/12/2022] Open
Abstract
Syndromic retinitis pigmentosa (RP) is the result of several mutations expressed in rod photoreceptors, over 40 of which have so far been identified. Enormous efforts are being made to relate the advances in unraveling the patho-physiological mechanisms to therapeutic approaches in animal models, and eventually in clinical trials on humans. This review summarizes briefly the current clinical management of RP and focuses on the new exciting treatment possibilities. To date, there is no approved therapy able to stop the evolution of RP or restore vision. The current management includes an attempt at slowing down the degenerative process by vitamin supplementation, trying to treat ocular complications and to provide psychological support to blind patients. Novel therapeutic may be tailored dependant on the stage of the disease and can be divided in three groups. In the early stages, when there are surviving photoreceptors, the first approach would be to try to halt the degeneration by correction of the underlying biochemical abnormality in the visual cycle using gene therapy or pharmacological treatment. A second approach aims to cope with photoreceptor cell death using neurotrophic growth factors or anti-apoptotic factors, reducing the production of retino-toxic molecules, and limiting oxidative damage. In advanced stages, when there are few or no functional photoreceptors, strategies that may benefit include retinal transplantation, electronic retinal implants or a newly described optogenetic technique using a light-activated channel to genetically resensitize remnant cone-photoreceptor cells.
Collapse
Affiliation(s)
- Jayashree N Sahni
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | | | | | | | | | | |
Collapse
|
103
|
Hu G, Huang K, Yu J, Gopalakrishna-Pillai S, Kong J, Xu H, Liu Z, Zhang K, Xu J, Luo Y, Li S, Sun YE, Iverson LE, Xue Z, Fan G. Identification of miRNA signatures during the differentiation of hESCs into retinal pigment epithelial cells. PLoS One 2012; 7:e37224. [PMID: 22848339 PMCID: PMC3407211 DOI: 10.1371/journal.pone.0037224] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 04/16/2012] [Indexed: 01/10/2023] Open
Abstract
Retinal pigment epithelium (RPE) cells can be obtained through in vitro differentiation of both embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). We have previously identified 87 signature genes relevant to RPE cell differentiation and function through transcriptome analysis of both human ESC- and iPSC-derived RPE as well as normal fetal RPE. Here, we profile miRNA expression through small RNA-seq in human ESCs and their RPE derivatives. Much like conclusions drawn from our previous transcriptome analysis, we find that the overall miRNA landscape in RPE is distinct from ESCs and other differentiated somatic tissues. We also profile miRNA expression during intermediate stages of RPE differentiation and identified unique subsets of miRNAs that are gradually up- or down-regulated, suggesting that dynamic regulation of these miRNAs is associated with the RPE differentiation process. Indeed, the down-regulation of a subset of miRNAs during RPE differentiation is associated with up-regulation of RPE-specific genes, such as RPE65, which is exclusively expressed in RPE. We conclude that miRNA signatures can be used to classify different degrees of in vitro differentiation of RPE from human pluripotent stem cells. We suggest that RPE-specific miRNAs likely contribute to the functional maturation of RPE in vitro, similar to the regulation of RPE-specific mRNA expression.
Collapse
Affiliation(s)
- Ganlu Hu
- Translational Center for Stem Cell Research, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Kevin Huang
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Juehua Yu
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | | | - Jun Kong
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - He Xu
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Zhenshan Liu
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Kunshan Zhang
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Jun Xu
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Yuping Luo
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Siguang Li
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Yi E. Sun
- Translational Center for Stem Cell Research, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Linda E. Iverson
- Stem Cell Biology, Beckman Research Institute of City of Hope, Duarte, California, United States of America
| | - Zhigang Xue
- Translational Center for Stem Cell Research, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
- * E-mail: (GF); (ZX)
| | - Guoping Fan
- Stem Cell Research Center, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- * E-mail: (GF); (ZX)
| |
Collapse
|
104
|
Expression of Multipotent and Retinal Markers in Pigment Epithelium of Adult Human in Vitro. Bull Exp Biol Med 2012; 153:157-62. [DOI: 10.1007/s10517-012-1666-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
105
|
Nita M, Strzałka-Mrozik B, Grzybowski A, Romaniuk W, Mazurek U. Ophthalmic transplantology: posterior segment of the eye--part II. Med Sci Monit 2012; 18:RA97-103. [PMID: 22648265 PMCID: PMC3560715 DOI: 10.12659/msm.882868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Transplants of the retina are among the new strategies being used in the treatment of genetic and degenerative macular diseases. Moreover, various cell cultures are being tested to treat retinal disorders. Material/Methods Literature dated from 2004 to 2011 was comprehensively examined via Medline and PubMed searches for the following terms: auto-, homo-, heterologous transplantation, retina, stem cells, cultivated cells. Results Tissue and cell therapy of retinal diseases are reviewed, including full-thickness retina/retinal pigment epithelium (RPE)/choroid graft; full and partial thickness RPE/choroid complex grafts; RPE/Bruch membrane complex graft; and RPE, iris pigment epithelium and stem cell grafts. Recommendations for transplants, as well as the benefits and weaknesses of specific techniques in retina transplants, are discussed. Conclusions Auto- and allogenic transplants of a full or partial thickness retina/RPE/Bruch membrane/choroid complex represent an alternative treatment offered to patients with some macular diseases. Stem cell transplantation to reconstruct and regenerate the macula requires further biomolecular and animal research studies.
Collapse
Affiliation(s)
- Małgorzata Nita
- Domestic and Specialized Medicine Centre Dilmed, Katowice, Poland
| | | | | | | | | |
Collapse
|
106
|
Abstract
The innate capacity of adult somatic cells has many potential applications in regenerative medicine. In this issue of Cell Stem Cell, Salero et al. (2012) describe an adult retinal stem cell population capable of generating neural and mesenchymal cell lineages.
Collapse
Affiliation(s)
- Pete Coffey
- Ocular Biology and Therapeutics, UCL-Institute of Ophthalmology, London EC1V 9EL, UK.
| |
Collapse
|
107
|
Mazumder MAJ, Fitzpatrick SD, Muirhead B, Sheardown H. Cell-adhesive thermogelling PNIPAAm/hyaluronic acid cell delivery hydrogels for potential application as minimally invasive retinal therapeutics. J Biomed Mater Res A 2012; 100:1877-87. [DOI: 10.1002/jbm.a.34021] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 10/28/2011] [Accepted: 11/07/2011] [Indexed: 01/28/2023]
|
108
|
Sanie-Jahromi F, Ahmadieh H, Soheili ZS, Davari M, Ghaderi S, Kanavi MR, Samiei S, Deezagi A, Pakravesh J, Bagheri A. Enhanced generation of retinal progenitor cells from human retinal pigment epithelial cells induced by amniotic fluid. BMC Res Notes 2012; 5:182. [PMID: 22490806 PMCID: PMC3428660 DOI: 10.1186/1756-0500-5-182] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/04/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Retinal progenitor cells are a convenient source of cell replacement therapy in retinal degenerative disorders. The purpose of this study was to evaluate the expression patterns of the homeobox genes PAX6 and CHX10 (retinal progenitor markers) during treatment of human retinal pigment epithelium (RPE) cells with amniotic fluid (AF), RPE cells harvested from neonatal cadaver globes were cultured in a mixture of DMEM and Ham's F12 supplemented with 10% FBS. At different passages, cells were trypsinized and co-cultured with 30% AF obtained from normal fetuses of 1416 weeks gestational age. RESULTS Compared to FBS-treated controls, AF-treated cultures exhibited special morphological changes in culture, including appearance of spheroid colonies, improved initial cell adhesion and ordered cell alignment. Cell proliferation assays indicated a remarkable increase in the proliferation rate of RPE cells cultivated in 30% AF-supplemented medium, compared with those grown in the absence of AF. Immunocytochemical analyses exhibited nuclear localization of retinal progenitor markers at a ratio of 33% and 27% for CHX10 and PAX6, respectively. This indicated a 3-fold increase in retinal progenitor markers in AF-treated cultures compared to FBS-treated controls. Real-time PCR data of retinal progenitor genes (PAX6, CHX10 and VSX-1) confirmed these results and demonstrated AF's capacity for promoting retinal progenitor cell generation. CONCLUSION Taken together, the results suggest that AF significantly promotes the rate of retinal progenitor cell generation, indicating that AF can be used as an enriched supplement for serum-free media used for the in vitro propagation of human progenitor cells.
Collapse
|
109
|
Jarrett SG, Boulton ME. Consequences of oxidative stress in age-related macular degeneration. Mol Aspects Med 2012; 33:399-417. [PMID: 22510306 DOI: 10.1016/j.mam.2012.03.009] [Citation(s) in RCA: 368] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 03/31/2012] [Indexed: 12/24/2022]
Abstract
The retina resides in an environment that is primed for the generation of reactive oxygen species (ROS) and resultant oxidative damage. The retina is one of the highest oxygen-consuming tissues in the human body. The highest oxygen levels are found in the choroid, but this falls dramatically across the outermost retina, creating a large gradient of oxygen towards the retina and inner segments of the photoreceptors which contain high levels of polyunsaturated fatty acids. This micro-environment together with abundant photosensitizers, visible light exposure and a high energy demand supports a highly oxidative milieu. However, oxidative damage is normally minimized by the presence of a range of antioxidant and efficient repair systems. Unfortunately, as we age oxidative damage increases, antioxidant capacity decreases and the efficiency of reparative systems become impaired. The result is retinal dysfunction and cell loss leading to visual impairment. It appears that these age-related oxidative changes are a hallmark of early age-related macular degeneration (AMD) which, in combination with hereditary susceptibility and other retinal modifiers, can progress to the pathology and visual morbidity associated with advanced AMD. This review reassesses the consequences of oxidative stress in AMD and strategies for preventing or reversing oxidative damage in retinal tissues.
Collapse
Affiliation(s)
- Stuart G Jarrett
- Department of Molecular and Biomedical Pharmacology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | | |
Collapse
|
110
|
Rowland TJ, Buchholz DE, Clegg DO. Pluripotent human stem cells for the treatment of retinal disease. J Cell Physiol 2012; 227:457-66. [PMID: 21520078 DOI: 10.1002/jcp.22814] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Despite advancements made in our understanding of ocular biology, therapeutic options for many debilitating retinal diseases remain limited. Stem cell-based therapies are a potential avenue for treatment of retinal disease, and this mini-review will focus on current research in this area. Cellular therapies to replace retinal pigmented epithelium (RPE) and/or photoreceptors to treat age-related macular degeneration (AMD), Stargardt's macular dystrophy, and retinitis pigmentosa are currently being developed. Over the past decade, significant advancements have been made using different types of human stem cells with varying capacities to differentiate into these target retinal cell types. We review and evaluate pluripotent stem cells, both human embryonic stem cells and human induced pluripotent stem cells, as well as protocols for differentiation of ocular cells, and culture and transplant techniques that might be used to deliver cells to patients.
Collapse
Affiliation(s)
- Teisha J Rowland
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California, USA
| | | | | |
Collapse
|
111
|
McGill TJ, Cottam B, Lu B, Wang S, Girman S, Tian C, Huhn SL, Lund RD, Capela A. Transplantation of human central nervous system stem cells - neuroprotection in retinal degeneration. Eur J Neurosci 2012; 35:468-77. [PMID: 22277045 DOI: 10.1111/j.1460-9568.2011.07970.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Stem cells derived from the human brain and grown as neurospheres (HuCNS-SC) have been shown to be effective in treating central neurodegenerative conditions in a variety of animal models. Human safety data in neurodegenerative disorders are currently being accrued. In the present study, we explored the efficacy of HuCNS-SC in a rodent model of retinal degeneration, the Royal College of Surgeons (RCS) rat, and extended our previous cell transplantation studies to include an in-depth examination of donor cell behavior and phenotype post-transplantation. As a first step, we have shown that HuCNS-SC protect host photoreceptors and preserve visual function after transplantation into the subretinal space of postnatal day 21 RCS rats. Moreover, cone photoreceptor density remained relatively constant over several months, consistent with the sustained visual acuity and luminance sensitivity functional outcomes. The novel findings of this study include the characterization and quantification of donor cell radial migration from the injection site and within the subretinal space as well as the demonstration that donor cells maintain an immature phenotype throughout the 7 months of the experiment and undergo very limited proliferation with no evidence of uncontrolled growth or tumor-like formation. Given the efficacy findings and lack of adverse events in the RCS rat in combination with the results from ongoing clinical investigations, HuCNS-SC appear to be a well-suited candidate for cell therapy in retinal degenerative conditions.
Collapse
Affiliation(s)
- Trevor J McGill
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, OR 97239, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
112
|
Electric impedance of human embryonic stem cell-derived retinal pigment epithelium. Med Biol Eng Comput 2011; 50:107-16. [PMID: 22189964 DOI: 10.1007/s11517-011-0850-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Accepted: 12/03/2011] [Indexed: 10/14/2022]
Abstract
The barrier properties of epithelium are conventionally defined by transepithelial resistance (TER). TER provides information about the tightness of the epithelium. Electrical impedance spectroscopy (EIS) provides additional information regarding cell membrane properties, such as changes in electric capacitance and possible parallel or serial pathways that may correlate with the morphology of the cell layer. This study presents EIS of retinal pigment epithelial (RPE) cell model of the putative RPE differentiated from human embryonic stem cells (hESC-RPE). The generally utilized RPE cell model, ARPE-19, was used as immature control. The measured EIS was analyzed by fitting an equivalent electrical circuit model describing the resistive and capacitive properties of the RPE. Our results indicated that TER of hESC-RPE cells was close to the values of human RPE presented in the literature. This provides evidence that the stem cell-derived RPE in vitro can reach high-barrier function. Furthermore, hESC-RPE cells produced impedance spectra that can be modeled by the equivalent circuit of one time constant. ARPE-19 cells produced low-barrier properties, that is, an impedance spectra that suggested poor maturation of ARPE-19 cells. To conclude, EIS could give us means for non-invasively estimating the functionality and maturation of differentiated-RPE cells.
Collapse
|
113
|
Degenring RF, Cordes A, Schrage NF. Autologous translocation of the retinal pigment epithelium and choroid in the treatment of neovascular age-related macular degeneration. Acta Ophthalmol 2011; 89:654-9. [PMID: 20346087 DOI: 10.1111/j.1755-3768.2010.01867.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate clinical results of an autologous translocation of retinal pigment epithelium (RPE) and choroid in the treatment of neovascular age-related macular degeneration (AMD). METHODS Twelve eyes which underwent surgery for neovascular AMD were included into the study, in four eyes moderate or massive submacular haemorrhage was present. The surgical procedure included standard pars plana vitrectomy; cataract surgery in phakic patients; peripheral 180°-retinotomy; extraction of the submacular neovascular complex and removal of blood if present; preparation of a full-thickness graft consisting of RPE, Bruch's membrane and choroid; translocation of the graft to the macular area; and silicone oil endotamponade. RESULTS Visual acuity (VA) ranged from perception of hand movements (HM) to 20/125 (median, counting fingers (CF)-1/50) before surgery. During follow-up (FU) mean, 11.1 months, VA increased to a maximum median of 1/10 (range, HM-20/40). At the end of FU, VA had dropped to a median of CF-1/40 (range, HM-20/50). Comparing VA preoperatively and at the end of FU, VA had improved in six eyes, was unchanged in three eyes, and had deteriorated in three eyes. One eye had reading ability. Surgery-associated postoperative complications impairing the functional outcome occurred in five eyes, including rhegmatogenous retinal detachment and proliferative vitreoretinopathy. Revision surgery had to be performed in four eyes (30%). Three eyes had to be left with permanent silicone endotamponade. Results tended to be better in the subgroup of eyes with massive submacular haemorrhage preoperatively. CONCLUSION Functional results of a translocation of RPE and choroid were heterogeneous and rather disappointing in this study. Results may have been influenced negatively by case selection. We found a relatively high rate of adverse events in the postoperative course. In selected cases, e.g. massive submacular haemorrhage or progressive neovascular AMD unresponsive to other treatment options, autologous translocation of RPE and choroid may still be considered.
Collapse
Affiliation(s)
- Robert F Degenring
- Department of Ophthalmology Cologne-Merheim, Cologne Hospitals, Germany.
| | | | | |
Collapse
|
114
|
Ferretti P. Is there a relationship between adult neurogenesis and neuron generation following injury across evolution? Eur J Neurosci 2011; 34:951-62. [DOI: 10.1111/j.1460-9568.2011.07833.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
115
|
Impedance Spectroscopy in Monitoring the Maturation of Stem Cell-Derived Retinal Pigment Epithelium. Ann Biomed Eng 2011; 39:3055-69. [DOI: 10.1007/s10439-011-0387-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/22/2011] [Indexed: 02/07/2023]
|
116
|
Wong IYH, Poon MW, Pang RTW, Lian Q, Wong D. Promises of stem cell therapy for retinal degenerative diseases. Graefes Arch Clin Exp Ophthalmol 2011; 249:1439-48. [PMID: 21866334 PMCID: PMC3178027 DOI: 10.1007/s00417-011-1764-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/19/2011] [Accepted: 07/28/2011] [Indexed: 12/31/2022] Open
Abstract
With the development of stem cell technology, stem cell-based therapy for retinal degeneration has been proposed to restore the visual function. Many animal studies and some clinical trials have shown encouraging results of stem cell-based therapy in retinal degenerative diseases. While stem cell-based therapy is a promising strategy to replace damaged retinal cells and ultimately cure retinal degeneration, there are several important challenges which need to be overcome before stem cell technology can be applied widely in clinical settings. In this review, different types of donor cell origins used in retinal treatments, potential target cell types for therapy, methods of stem cell delivery to the eye, assessments of potential risks in stem cell therapy, as well as future developments of retinal stem cells therapy, will be discussed.
Collapse
Affiliation(s)
- Ian Yat-Hin Wong
- Department of Medicine and Eye Institute, Li Ka Shing Faculty of Medicine, University of Hong Kong, Pokfulam, Hong Kong SAR, PRC
| | | | | | | | | |
Collapse
|
117
|
Polyurethanes as supports for human retinal pigment epithelium cell growth. Int J Artif Organs 2011; 34:198-209. [PMID: 21374562 DOI: 10.5301/ijao.2011.6398] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2010] [Indexed: 11/20/2022]
Abstract
PURPOSE The transplant of retinal pigment epithelium (RPE) cells on supports may well be an effective therapeutic approach to improve the visual results of patients with age-related macular degeneration. In this study, two biodegradable polyurethanes were investigated as supports for human RPE cells (ARPE-19). METHODS Polyurethane aqueous dispersions based on poly(caprolactone) and/or poly(ethylene glycol) as soft segments, and isophorone diisocyanate and hydrazine as hard segments were prepared. Polyurethane films were produced by casting the dispersions and allowing them to dry at room temperature for one week. The ARPE-19 cells were seeded onto the polyurethane films and they were investigated as supports for in vitro adhesion, proliferation, and uniform distribution of differentiated ARPE-19 cells. Additionally, the in vivo ocular biocompatibility of the polyurethane films was evaluated. RESULTS The RPE adhered to and proliferated onto the polyurethane supports, thus establishing cell-PUD surface interactions. Upon confluence, the cells formed an organized monolayer, exhibited a polygonal appearance, and displayed actin filaments which ran along the upper cytoplasm. At 15 days of seeding, the occluding expression was confirmed between adjacent cells, representing the barrier functionality of epithelial cells on polymeric surfaces and the establishment of cell-cell interactions. Results from the in vivo study indicated that polyurethanes exhibited a high degree of short-term intraocular biocompatibility. CONCLUSIONS Biodegradable polyurethane films display the proper mechanical properties for an easy transscleral-driven subretinal implantation and can be considered as biocompatible supports for a functional ARPE-19 monolayer.
Collapse
|
118
|
Sugino IK, Sun Q, Wang J, Nunes CF, Cheewatrakoolpong N, Rapista A, Johnson AC, Malcuit C, Klimanskaya I, Lanza R, Zarbin MA. Comparison of FRPE and human embryonic stem cell-derived RPE behavior on aged human Bruch's membrane. Invest Ophthalmol Vis Sci 2011; 52:4979-97. [PMID: 21460262 DOI: 10.1167/iovs.10-5386] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To compare RPE derived from human embryonic stem cells (hES-RPE) and fetal RPE (fRPE) behavior on human Bruch's membrane (BM) from aged and AMD donors. METHODS hES-RPE of 3 degrees of pigmentation and fRPE were cultured on BM explants. Explants were assessed by light, confocal, and scanning electron microscopy. Integrin mRNA levels were determined by real-time polymerase chain reaction studies. Secreted proteins in media were analyzed by multiplex protein analysis after 48-hour exposure at culture day 21. RESULTS hES-RPE showed impaired initial attachment compared to fRPE; pigmented hES-RPE showed nuclear densities similar to fRPE at day 21. At days 3 and 7, hES-RPE resurfaced BM to a limited degree, showed little proliferation (Ki-67), and partial retention of RPE markers (MITF, cytokeratin, and CRALBP). TUNEL-positive nuclei were abundant at day 3. fRPE exhibited substantial BM resurfacing at day 3 with decreased resurfacing at later times. Most fRPE retained RPE markers. Ki-67-positive nuclei decreased with time in culture. TUNEL staining was variable. Increased integrin mRNA expression did not appear to affect cell survival at day 21. hES-RPE and fRPE protein secretion was similar on equatorial BM except for higher levels of nerve growth factor and thrombospondin-2 (TSP2) by hES-RPE. On submacular BM, fRPE secreted more vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, and platelet-derived growth factor; hES-RPE secreted more TSP2. CONCLUSIONS Although pigmented hES-RPE and fRPE resurfaced aged and AMD BM to a similar, limited degree at day 21, cell behavior at earlier times was markedly dissimilar. Differences in protein secretion may indicate that hES-RPE may not function identically to native RPE after seeding on aged or AMD BM.
Collapse
Affiliation(s)
- Ilene K Sugino
- The Institute of Ophthalmology and Visual Science, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, 90 Bergen Street, Newark, NJ 07101, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
119
|
Rizzolo LJ, Peng S, Luo Y, Xiao W. Integration of tight junctions and claudins with the barrier functions of the retinal pigment epithelium. Prog Retin Eye Res 2011; 30:296-323. [PMID: 21704180 DOI: 10.1016/j.preteyeres.2011.06.002] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 06/01/2011] [Accepted: 06/06/2011] [Indexed: 02/02/2023]
Abstract
The retinal pigment epithelium (RPE) forms the outer blood-retinal barrier by regulating the movement of solutes between the fenestrated capillaries of the choroid and the photoreceptor layer of the retina. Blood-tissue barriers use various mechanisms to accomplish their tasks including membrane pumps, transporters, and channels, transcytosis, metabolic alteration of solutes in transit, and passive but selective diffusion. The last category includes tight junctions, which regulate transepithelial diffusion through the spaces between neighboring cells of the monolayer. Tight junctions are extraordinarily complex structures that are dynamically regulated. Claudins are a family of tight junctional proteins that lend tissue specificity and selectivity to tight junctions. This review discusses how the claudins and tight junctions of the RPE differ from other epithelia and how its functions are modulated by the neural retina. Studies of RPE-retinal interactions during development lend insight into this modulation. Notably, the characteristics of RPE junctions, such as claudin composition, vary among species, which suggests the physiology of the outer retina may also vary. Comparative studies of barrier functions among species should deepen our understanding of how homeostasis is maintained in the outer retina. Stem cells provide a way to extend these studies of RPE-retinal interactions to human RPE.
Collapse
Affiliation(s)
- Lawrence J Rizzolo
- Department of Surgery and Department of Ophthalmology and Visual Science, Yale University School of Medicine, PO Box 208062, New Haven, CT 06520-8062, USA.
| | | | | | | |
Collapse
|
120
|
Srivastava GK, Martín L, Singh AK, Fernandez-Bueno I, Gayoso MJ, Garcia-Gutierrez MT, Girotti A, Alonso M, Rodríguez-Cabello JC, Pastor JC. Elastin-like recombinamers as substrates for retinal pigment epithelial cell growth. J Biomed Mater Res A 2011; 97:243-50. [DOI: 10.1002/jbm.a.33050] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 12/17/2010] [Accepted: 01/10/2011] [Indexed: 12/19/2022]
|
121
|
Sugino IK, Gullapalli VK, Sun Q, Wang J, Nunes CF, Cheewatrakoolpong N, Johnson AC, Degner BC, Hua J, Liu T, Chen W, Li H, Zarbin MA. Cell-deposited matrix improves retinal pigment epithelium survival on aged submacular human Bruch's membrane. Invest Ophthalmol Vis Sci 2011; 52:1345-58. [PMID: 21398292 DOI: 10.1167/iovs.10-6112] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE To determine whether resurfacing submacular human Bruch's membrane with a cell-deposited extracellular matrix (ECM) improves retinal pigment epithelial (RPE) survival. METHODS Bovine corneal endothelial (BCE) cells were seeded onto the inner collagenous layer of submacular Bruch's membrane explants of human donor eyes to allow ECM deposition. Control explants from fellow eyes were cultured in medium only. The deposited ECM was exposed by removing BCE. Fetal RPE cells were then cultured on these explants for 1, 14, or 21 days. The explants were analyzed quantitatively by light microscopy and scanning electron microscopy. Surviving RPE cells from explants cultured for 21 days were harvested to compare bestrophin and RPE65 mRNA expression. Mass spectroscopy was performed on BCE-ECM to examine the protein composition. RESULTS The BCE-treated explants showed significantly higher RPE nuclear density than did the control explants at all time points. RPE expressed more differentiated features on BCE-treated explants than on untreated explants, but expressed very little mRNA for bestrophin or RPE65. The untreated young (<50 years) and African American submacular Bruch's membrane explants supported significantly higher RPE nuclear densities (NDs) than did the Caucasian explants. These differences were reduced or nonexistent in the BCE-ECM-treated explants. Proteins identified in the BCE-ECM included ECM proteins, ECM-associated proteins, cell membrane proteins, and intracellular proteins. CONCLUSIONS Increased RPE survival can be achieved on aged submacular human Bruch's membrane by resurfacing the latter with a cell-deposited ECM. Caucasian eyes seem to benefit the most, as cell survival is the worst on submacular Bruch's membrane in these eyes.
Collapse
Affiliation(s)
- Ilene K Sugino
- The Institute of Ophthalmology and Visual Science, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07101-1709, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
122
|
Zhu D, Deng X, Spee C, Sonoda S, Hsieh CL, Barron E, Pera M, Hinton DR. Polarized secretion of PEDF from human embryonic stem cell-derived RPE promotes retinal progenitor cell survival. Invest Ophthalmol Vis Sci 2011; 52:1573-85. [PMID: 21087957 DOI: 10.1167/iovs.10-6413] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
PURPOSE Human embryonic stem cell-derived RPE (hES-RPE) transplantation is a promising therapy for atrophic age-related macular degeneration (AMD); however, future therapeutic approaches may consider co-transplantation of hES-RPE with retinal progenitor cells (RPCs) as a replacement source for lost photoreceptors. The purpose of this study was to determine the effect of polarization of hES-RPE monolayers on their ability to promote survival of RPCs. METHODS The hES-3 cell line was used for derivation of RPE. Polarization of hES-RPE was achieved by prolonged growth on permeable inserts. RPCs were isolated from 16- to 18-week-gestation human fetal eyes. ELISA was performed to measure pigment epithelium-derived factor (PEDF) levels from conditioned media. RESULTS Pigmented RPE-like cells appeared as early as 4 weeks in culture and were subcultured at 8 weeks. Differentiated hES-RPE had a normal chromosomal karyotype. Phenotypically polarized hES-RPE cells showed expression of RPE-specific genes. Polarized hES-RPE showed prominent expression of PEDF in apical cytoplasm and a marked increase in secretion of PEDF into the medium compared with nonpolarized culture. RPCs grown in the presence of supernatants from polarized hES-RPE showed enhanced survival, which was ablated by the presence of anti-PEDF antibody. CONCLUSIONS hES-3 cells can be differentiated into functionally polarized hES-RPE cells that exhibit characteristics similar to those of native RPE. On polarization, hES-RPE cells secrete high levels of PEDF that can support RPC survival. These experiments suggest that polarization of hES-RPE would be an important feature for promotion of RPC survival in future cell therapy for atrophic AMD.
Collapse
Affiliation(s)
- Danhong Zhu
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA
| | | | | | | | | | | | | | | |
Collapse
|
123
|
Dahlmann-Noor A, Vijay S, Jayaram H, Limb A, Khaw PT. Current approaches and future prospects for stem cell rescue and regeneration of the retina and optic nerve. Can J Ophthalmol 2010; 45:333-41. [PMID: 20648090 DOI: 10.3129/i10-077] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The 3 most common causes of visual impairment and legal blindness in developed countries (age-related macular degeneration, glaucoma, and diabetic retinopathy) share 1 end point: the loss of neural cells of the eye. Although recent treatment advances can slow down the progression of these conditions, many individuals still suffer irreversible loss of vision. Research is aimed at developing new treatment strategies to rescue damaged photoreceptors and retinal ganglion cells (RGC) and to replace lost cells by transplant. The neuroprotective and regenerative potential of stem and progenitor cells from a variety of sources has been explored in models of retinal disease and ganglion cell loss. Continuous intraocular delivery of neurotrophic factors via stem cells (SC) slows down photoreceptor cells and RGC loss in experimental models. Following intraocular transplantation, SC are capable of expressing proteins and of developing a morphology characteristic of photoreceptors or RGC. Recently, recovery of vision has been achieved for the first time in a rodent model of retinal dystrophy, using embryonic SC differentiated into photoreceptors prior to transplant. This indicates that clinically significant synapse formation and acquisition of the functional properties of retinal neurons, and restoration of vision, are distinct future possibilities.
Collapse
|
124
|
Thomson HA, Treharne AJ, Backholer LS, Cuda F, Grossel MC, Lotery AJ. Biodegradable poly(α-hydroxy ester) blended microspheres as suitable carriers for retinal pigment epithelium cell transplantation. J Biomed Mater Res A 2010; 95:1233-43. [DOI: 10.1002/jbm.a.32940] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 07/02/2010] [Accepted: 07/08/2010] [Indexed: 11/06/2022]
|
125
|
Bharti K, Miller SS, Arnheiter H. The new paradigm: retinal pigment epithelium cells generated from embryonic or induced pluripotent stem cells. Pigment Cell Melanoma Res 2010; 24:21-34. [PMID: 20846177 DOI: 10.1111/j.1755-148x.2010.00772.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Compared with neural crest-derived melanocytes, retinal pigment epithelium (RPE) cells in the back of the eye are pigment cells of a different kind. They are a part of the brain, form an epithelial monolayer, respond to distinct extracellular signals, and provide functions that far exceed those of a light-absorbing screen. For instance, they control nutrient and metabolite flow to and from the retina, replenish 11-cis-retinal by re-isomerizing all-trans-retinal generated during photoconversion, phagocytose daily a portion of the photoreceptors' outer segments, and secrete cytokines that locally control the innate and adaptive immune systems. Not surprisingly, RPE cell damage is a major cause of human blindness worldwide, with age-related macular degeneration a prevalent example. RPE replacement therapies using RPE cells generated from embryonic or induced pluripotent stem cells provide a novel approach to a rational treatment of such forms of blindness. In fact, RPE-like cells can be obtained relatively easily when stem cells are subjected to a two-step induction protocol, a first step that leads to a neuroectodermal fate and a second to RPE differentiation. Here, we discuss the characteristics of such cells, propose criteria they should fulfill in order to be considered authentic RPE cells, and point out the challenges one faces when using such cells in attempts to restore vision.
Collapse
Affiliation(s)
- Kapil Bharti
- Mammalian Development Section, National Institutes of Neurological Disorders and Stroke, Bethesda, MD, USA.
| | | | | |
Collapse
|
126
|
Liao JL, Yu J, Huang K, Hu J, Diemer T, Ma Z, Dvash T, Yang XJ, Travis GH, Williams DS, Bok D, Fan G. Molecular signature of primary retinal pigment epithelium and stem-cell-derived RPE cells. Hum Mol Genet 2010; 19:4229-38. [PMID: 20709808 DOI: 10.1093/hmg/ddq341] [Citation(s) in RCA: 153] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Age-related macular degeneration (AMD) is characterized by the loss or dysfunction of retinal pigment epithelium (RPE) and is the most common cause of vision loss among the elderly. Stem-cell-based strategies, using human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (hiPSCs), may provide an abundant donor source for generating RPE cells in cell replacement therapies. Despite a significant amount of research on deriving functional RPE cells from various stem cell sources, it is still unclear whether stem-cell-derived RPE cells fully mimic primary RPE cells. In this report, we demonstrate that functional RPE cells can be derived from multiple lines of hESCs and hiPSCs with varying efficiencies. Stem-cell-derived RPE cells exhibit cobblestone-like morphology, transcripts, proteins and phagocytic function similar to human fetal RPE (fRPE) cells. In addition, we performed global gene expression profiling of stem-cell-derived RPE cells, native and cultured fRPE cells, undifferentiated hESCs and fibroblasts to determine the differentiation state of stem-cell-derived RPE cells. Our data indicate that hESC-derived RPE cells closely resemble human fRPE cells, whereas hiPSC-derived RPE cells are in a unique differentiation state. Furthermore, we identified a set of 87 signature genes that are unique to human fRPE and a majority of these signature genes are shared by stem-cell-derived RPE cells. These results establish a panel of molecular markers for evaluating the fidelity of human pluripotent stem cell to RPE conversion. This study contributes to our understanding of the utility of hESC/hiPSC-derived RPE in AMD therapy.
Collapse
Affiliation(s)
- Jo-Ling Liao
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
127
|
Gamboa OL, Pu J, Townend J, Forrester JV, Zhao M, McCaig C, Lois N. Electrical estimulation of retinal pigment epithelial cells. Exp Eye Res 2010; 91:195-204. [DOI: 10.1016/j.exer.2010.04.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 01/21/2023]
|
128
|
|
129
|
Wang NK, Tosi J, Kasanuki JM, Chou CL, Kong J, Parmalee N, Wert KJ, Allikmets R, Lai CC, Chien CL, Nagasaki T, Lin CS, Tsang SH. Transplantation of reprogrammed embryonic stem cells improves visual function in a mouse model for retinitis pigmentosa. Transplantation 2010; 89:911-9. [PMID: 20164818 PMCID: PMC2855750 DOI: 10.1097/tp.0b013e3181d45a61] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND To study whether C57BL/6J-Tyr/J (C2J) mouse embryonic stem (ES) cells can differentiate into retinal pigment epithelial (RPE) cells in vitro and then restore retinal function in a model for retinitis pigmentosa: Rpe65/Rpe65 C57BL6 mice. METHODS Yellow fluorescent protein (YFP)-labeled C2J ES cells were induced to differentiate into RPE-like structures on PA6 feeders. RPE-specific markers are expressed from differentiated cells in vitro. After differentiation, ES cell-derived RPE-like cells were transplanted into the subretinal space of postnatal day 5 Rpe65/Rpe65 mice. Live imaging of YFP-labeled C2J ES cells demonstrated survival of the graft. Electroretinograms (ERGs) were performed on transplanted mice to evaluate the functional outcome of transplantation. RESULTS RPE-like cells derived from ES cells sequentially express multiple RPE-specific markers. After transplantation, YFP-labeled cells can be tracked with live imaging for as long as 7 months. Although more than half of the mice were complicated with retinal detachments or tumor development, one fourth of the mice showed increased electroretinogram responses in the transplanted eyes. Rpe65/Rpe65 mice transplanted with RPE-like cells showed significant visual recovery during a 7-month period, whereas those injected with saline, PA6 feeders, or undifferentiated ES cells showed no rescue. CONCLUSIONS ES cells can differentiate, morphologically, and functionally, into RPE-like cells. Based on these findings, differentiated ES cells have the potential for the development of new therapeutic approaches for RPE-specific diseases such as certain forms of retinitis pigmentosa and macular degeneration. Nevertheless, stringent control of retinal detachment and teratoma development will be necessary before initiation of treatment trials.
Collapse
Affiliation(s)
- Nan-Kai Wang
- Department of Ophthalmology, Columbia University, New York City, NY
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Chang Gung University College of Medicine, Taoyuan, Taiwan
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan
| | - Joaquin Tosi
- Department of Ophthalmology, Columbia University, New York City, NY
| | | | - Chai Lin Chou
- Department of Ophthalmology, Columbia University, New York City, NY
| | - Jian Kong
- Department of Ophthalmology, Columbia University, New York City, NY
| | - Nancy Parmalee
- Department of Ophthalmology, Columbia University, New York City, NY
- Department of Genetics and Development, Columbia University, New York, NY
| | - Katherine J. Wert
- Department of Ophthalmology, Columbia University, New York City, NY
- Institute of Human Nutrient, Columbia University, New York, NY
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York City, NY
- Department of Pathology and Cell Biology, Columbia University, New York, NY
| | - Chi-Chun Lai
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Chung-Liang Chien
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei, Taiwan
| | | | - Chyuan-Sheng Lin
- Department of Ophthalmology, Columbia University, New York City, NY
- Department of Pathology and Cell Biology, Columbia University, New York, NY
- Bernard and Shirlee Brown Glaucoma Laboratory, Columbia University, New York City, NY
| | - Stephen H. Tsang
- Department of Ophthalmology, Columbia University, New York City, NY
- Department of Pathology and Cell Biology, Columbia University, New York, NY
- Bernard and Shirlee Brown Glaucoma Laboratory, Columbia University, New York City, NY
| |
Collapse
|
130
|
Strunnikova NV, Maminishkis A, Barb JJ, Wang F, Zhi C, Sergeev Y, Chen W, Edwards AO, Stambolian D, Abecasis G, Swaroop A, Munson PJ, Miller SS. Transcriptome analysis and molecular signature of human retinal pigment epithelium. Hum Mol Genet 2010; 19:2468-86. [PMID: 20360305 PMCID: PMC2876890 DOI: 10.1093/hmg/ddq129] [Citation(s) in RCA: 201] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Retinal pigment epithelium (RPE) is a polarized cell layer critical for photoreceptor function and survival. The unique physiology and relationship to the photoreceptors make the RPE a critical determinant of human vision. Therefore, we performed a global expression profiling of native and cultured human fetal and adult RPE and determined a set of highly expressed ‘signature’ genes by comparing the observed RPE gene profiles to the Novartis expression database (SymAtlas: http://wombat.gnf.org/index.html) of 78 tissues. Using stringent selection criteria of at least 10-fold higher expression in three distinct preparations, we identified 154 RPE signature genes, which were validated by qRT-PCR analysis in RPE and in an independent set of 11 tissues. Several of the highly expressed signature genes encode proteins involved in visual cycle, melanogenesis and cell adhesion and Gene ontology analysis enabled the assignment of RPE signature genes to epithelial channels and transporters (ClCN4, BEST1, SLCA20) or matrix remodeling (TIMP3, COL8A2). Fifteen RPE signature genes were associated with known ophthalmic diseases, and 25 others were mapped to regions of disease loci. An evaluation of the RPE signature genes in a recently completed AMD genomewide association (GWA) data set revealed that TIMP3, GRAMD3, PITPNA and CHRNA3 signature genes may have potential roles in AMD pathogenesis and deserve further examination. We propose that RPE signature genes are excellent candidates for retinal diseases and for physiological investigations (e.g. dopachrome tautomerase in melanogenesis). The RPE signature gene set should allow the validation of RPE-like cells derived from human embryonic or induced pluripotent stem cells for cell-based therapies of degenerative retinal diseases.
Collapse
Affiliation(s)
- N V Strunnikova
- Ophthalmic Genetics & Visual Function Branch, NIH, Bethesda, MD 20892-2510, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
131
|
Afshari FT, Kwok JC, Andrews MR, Blits B, Martin KR, Faissner A, Ffrench-Constant C, Fawcett JW. Integrin activation or alpha 9 expression allows retinal pigmented epithelial cell adhesion on Bruch's membrane in wet age-related macular degeneration. ACTA ACUST UNITED AC 2010; 133:448-64. [PMID: 20159768 DOI: 10.1093/brain/awp319] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Retinal pigment epithelial cell malfunction is a causative feature of age-related macular degeneration, and transplantation of new retinal pigment epithelial cells is an attractive strategy to prevent further progression and visual loss. However, transplants have shown limited efficacy, mainly because transplanted cells fail to adhere and migrate onto pathological Bruch's membrane. Adhesion to Bruch's membrane is integrin-mediated. Ageing of Bruch's membrane leads to a decline in integrin ligands and, added to this, wet age-related macular degeneration leads to upregulation of anti-adhesive molecules such as tenascin-C. We have therefore investigated whether manipulation of integrin function in retinal pigment epithelial cells can restore their adhesion and migration on wet age-related macular degeneration-damaged Bruch's membrane. Using spontaneously immortalized human retinal pigment epithelial cells (adult retinal pigment epithelium-19), we show that adhesion and migration on the Bruch's membrane components is integrin-dependent and enhanced by integrin-activating agents manganese and TS2/16. These allowed cells to adhere and migrate on low concentrations of ligand, as would be found in aged Bruch's membrane. We next developed a method for stripping cells from Bruch's membrane so that adhesion and migration assays can be performed on its surface. Integrin activation had a moderate effect on enhancing retinal pigmented epithelial cell adhesion and migration on normal human and rat Bruch's membrane. However, on Bruch's membrane prepared from human wet age-related macular degeneration-affected eyes, adhesion was lower and integrin activation had a much greater effect. A candidate molecule for preventing retinal pigmented epithelial interaction with age-related macular degeneration-affected Bruch's membrane is tenascin-C which we confirm is present at high levels in wet age-related macular degeneration membrane. We show that tenascin-C is anti-adhesive for retinal pigmented epithelial cells, but after integrin activation, they can adhere and migrate on it using alphaVbeta3 integrin. Alternatively, we find that transduction of retinal pigmented epithelial cells with alpha9 integrin, a tenascin-C-binding integrin, led to a large increase in alpha9beta1-mediated adhesion and migration on tenascin-C. Both expression of alpha9 integrin and integrin activation greatly enhanced the ability of retinal pigment epithelial cells to adhere to tenascin-rich wet age-related macular degeneration-affected Bruch's membranes. Our results suggest that manipulation of retinal pigment epithelial cell integrins through integrin activating strategies, or expression of new integrins such as alpha9, could be effective in improving the efficacy of retinal pigment epithelial cell transplantation in wet age-related macular degeneration-affected eyes.
Collapse
Affiliation(s)
- Fardad T Afshari
- Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0PY, UK
| | | | | | | | | | | | | | | |
Collapse
|
132
|
Novel Therapy for Transthyretin–related Ocular Amyloidosis. Ophthalmology 2010; 117:552-5. [DOI: 10.1016/j.ophtha.2009.07.042] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/23/2009] [Accepted: 07/29/2009] [Indexed: 12/11/2022] Open
|
133
|
Ballios BG, Cooke MJ, van der Kooy D, Shoichet MS. A hydrogel-based stem cell delivery system to treat retinal degenerative diseases. Biomaterials 2010; 31:2555-64. [DOI: 10.1016/j.biomaterials.2009.12.004] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 12/01/2009] [Indexed: 12/21/2022]
|
134
|
A tissue-engineered approach towards retinal repair: scaffolds for cell transplantation to the subretinal space. Graefes Arch Clin Exp Ophthalmol 2010; 248:763-78. [PMID: 20169358 DOI: 10.1007/s00417-009-1263-7] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2009] [Revised: 11/16/2009] [Accepted: 11/26/2009] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Several mechanisms of retina degeneration result in the deterioration of the outer retina and can lead to blindness. Currently, with the exception of anti-angiogenic treatments for wet age-related macular degeneration, there are no treatments that can restore lost vision. There is evidence that photoreceptors and embryonic retinal tissue, transplanted to the subretinal space, can form new synapses with surviving host neurons. However, these transplants have yet to result in a clinical treatment for retinal degeneration. METHODS This article reviews the current literature on the transplantation of scaffolds with retinal and retinal pigmented epithelial (RPE) cells to the subretinal space. We discuss the types of cells and materials that have been investigated for transplantation to the subretinal space, summarize the current findings, and present opportunities for future research and the next generation of scaffolds for retinal repair. RESULTS Challenges to cell transplantation include limited survival upon implantation and the formation of abnormal cell architectures in vivo. Scaffolds have been shown to enhance cell survival and direct cell differentiation and organization in a number of models of retinal degeneration. CONCLUSIONS The transplantation of cells within a scaffold represents a possible treatment to repair retinal degeneration and restore vision in effected patients. Materials have been developed for the delivery of retinal and RPE cells separately however, the development of a combined tissue-engineered scaffold targeting both cell populations represents a promising direction for retinal repair.
Collapse
|
135
|
Abstract
PURPOSE OF REVIEW This review will discuss how recent advances with induced pluripotent stem (iPS) cells have brought the science of stem cell biology much closer to clinical application for patients with retinal degeneration. RECENT FINDINGS The ability to generate embryonic stem cells by reprogramming DNA taken from adult cells was demonstrated by the cloning of Dolly, the sheep, by somatic cell nuclear transfer, over 10 years ago. Recently, it has been shown that adult cells can be reprogrammed directly, without the need for a surrogate oocyte, through the generation of iPS cells. The method of reprogramming has since been optimized to avoid the use of retroviruses, making the process considerably safer. Last year, human iPS cells were isolated from an 80-year-old patient with neurodegenerative disease and differentiated into neurons in vitro. SUMMARY For stem cell therapies, the retina has the optimal combination of ease of surgical access, combined with an ability to observe transplanted cells directly through the clear ocular media. The question now is which retinal diseases are most appropriate targets for clinical trials using iPS cell approaches.
Collapse
Affiliation(s)
| | - Edward Lee
- Vitreoretinal Service, Moorfields Eye Hospital
- Moorfields UCL Institute of Ophthalmology NIHR Biomedical Research Centre
| | - Robert E MacLaren
- Vitreoretinal Service, Moorfields Eye Hospital
- Moorfields UCL Institute of Ophthalmology NIHR Biomedical Research Centre
- Nuffield Laboratory of Ophthalmology University of Oxford and Oxford Eye Hospital
| |
Collapse
|
136
|
Idelson M, Alper R, Obolensky A, Ben-Shushan E, Hemo I, Yachimovich-Cohen N, Khaner H, Smith Y, Wiser O, Gropp M, Cohen MA, Even-Ram S, Berman-Zaken Y, Matzrafi L, Rechavi G, Banin E, Reubinoff B. Directed differentiation of human embryonic stem cells into functional retinal pigment epithelium cells. Cell Stem Cell 2009; 5:396-408. [PMID: 19796620 DOI: 10.1016/j.stem.2009.07.002] [Citation(s) in RCA: 315] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 05/10/2009] [Accepted: 07/07/2009] [Indexed: 01/05/2023]
Abstract
Dysfunction and loss of retinal pigment epithelium (RPE) leads to degeneration of photoreceptors in age-related macular degeneration and subtypes of retinitis pigmentosa. Human embryonic stem cells (hESCs) may serve as an unlimited source of RPE cells for transplantation in these blinding conditions. Here we show the directed differentiation of hESCs toward an RPE fate under defined culture conditions. We demonstrate that nicotinamide promotes the differentiation of hESCs to neural and subsequently to RPE fate. In the presence of nicotinamide, factors from the TGF-beta superfamily, which presumably pattern RPE development during embryogenesis, further direct RPE differentiation. The hESC-derived pigmented cells exhibit the morphology, marker expression, and function of authentic RPE and rescue retinal structure and function after transplantation to an animal model of retinal degeneration caused by RPE dysfunction. These results are an important step toward the future use of hESCs to replenish RPE in blinding diseases.
Collapse
Affiliation(s)
- Maria Idelson
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy & Department of Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
137
|
Abstract
Retinal pigment epithelium (RPE) is a valuable cell type for a number of blinding disorders. In this issue of Cell Stem Cell, Idelson et al. (2009) use Nicotinamide and Activin A to markedly improve RPE yield from human embryonic stem cells.
Collapse
Affiliation(s)
- Barbara Corneo
- New York Neural Stem Cell Institute, One Discovery Drive, Rensselaer, NY 12144, USA
| | | |
Collapse
|
138
|
Carr AJ, Vugler AA, Hikita ST, Lawrence JM, Gias C, Chen LL, Buchholz DE, Ahmado A, Semo M, Smart MJK, Hasan S, da Cruz L, Johnson LV, Clegg DO, Coffey PJ. Protective effects of human iPS-derived retinal pigment epithelium cell transplantation in the retinal dystrophic rat. PLoS One 2009; 4:e8152. [PMID: 19997644 PMCID: PMC2780911 DOI: 10.1371/journal.pone.0008152] [Citation(s) in RCA: 334] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Accepted: 11/06/2009] [Indexed: 12/16/2022] Open
Abstract
Transformation of somatic cells with a set of embryonic transcription factors produces cells with the pluripotent properties of embryonic stem cells (ESCs). These induced pluripotent stem (iPS) cells have the potential to differentiate into any cell type, making them a potential source from which to produce cells as a therapeutic platform for the treatment of a wide range of diseases. In many forms of human retinal disease, including age-related macular degeneration (AMD), the underlying pathogenesis resides within the support cells of the retina, the retinal pigment epithelium (RPE). As a monolayer of cells critical to photoreceptor function and survival, the RPE is an ideally accessible target for cellular therapy. Here we report the differentiation of human iPS cells into RPE. We found that differentiated iPS-RPE cells were morphologically similar to, and expressed numerous markers of developing and mature RPE cells. iPS-RPE are capable of phagocytosing photoreceptor material, in vitro and in vivo following transplantation into the Royal College of Surgeons (RCS) dystrophic rat. Our results demonstrate that iPS cells can be differentiated into functional iPS-RPE and that transplantation of these cells can facilitate the short-term maintenance of photoreceptors through phagocytosis of photoreceptor outer segments. Long-term visual function is maintained in this model of retinal disease even though the xenografted cells are eventually lost, suggesting a secondary protective host cellular response. These findings have identified an alternative source of replacement tissue for use in human retinal cellular therapies, and provide a new in vitro cellular model system in which to study RPE diseases affecting human patients.
Collapse
Affiliation(s)
- Amanda-Jayne Carr
- Department of Ocular Biology and Therapeutics, Institute of Ophthalmology, University College London, London, United Kingdom.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
139
|
Surgery for CNV and autologous choroidal RPE patch transplantation: exposing the submacular space. Graefes Arch Clin Exp Ophthalmol 2009; 248:37-47. [PMID: 19802629 DOI: 10.1007/s00417-009-1201-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 08/09/2009] [Accepted: 09/07/2009] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND To evaluate the feasibility of transplanting a full-thickness patch of choroid, choriocapillaries, Bruch's membrane and RPE (RPE-choroid FTAP) from the peripheral to the subfoveal area of the same eye, after performing a 180 degrees peripheral retinotomy and removing subfoveal choroidal neovascularization. Thereafter, to study the surgical complications, anatomical outcome and patch perfusion during follow-up. METHODS A retrospective case series of 13 eyes of 13 consecutive patients with a follow-up of 4 to 20 months. All patients suffered from advanced subfoveal choroidal neovascularization and were non-responders to standard care. After performing a complete vitrectomy, a 180 degrees peripheral temporal retinotomy and the removal of subfoveal neovascularization, a FTAP of choroid, choriocapillaris, Bruch's membrane and the RPE were isolated from the mid periphery of the uveal bed, transpositioned under the fovea and covered with the retina. Patients received a complete ophthalmic examination, fluorescein angiography (FA), indocyanin green angiography (ICGA) and optical coherence tomography (OCT) during follow-up. RESULTS An FTAP could be harvested in every eye and transplanted under the fovea. No intraoperative complications occurred. The FTAP was recognizable at FA, ICGA and OCT at each time point, up to 20 months postoperatively. Perfusion of the choroidal bed were observed into the FTAP during follow-up, from one week after surgery. CONCLUSION The creation of an FTAP through a 180 degrees peripheral retinotomy is feasible and safe. The FTAP is vital and perfused. Further studies are needed to collect more data.
Collapse
|
140
|
Abstract
Topical and systemic administration of drugs to the eye is highly inefficient and there is a need for controlled, sustained release, particularly for conditions that affect the posterior segment. Various nonimplantable and implantable drug delivery devices have been developed. Colloidal carriers may allow targeted drug delivery and afford protection to substances that are sensitive to degradation, particularly RNA/DNA-based treatments. Gene therapy and cell transplantation are also starting to emerge as alternatives to conventional pharmacological treatment. There is the potential to use existing ocular devices to deliver drugs. In order to exploit this opportunity, modifications to drugs and devices, along with clarification of the appropriate drug dose, must be undertaken. This review will describe some of the treatment options for ocular disease and barriers to drug delivery, discuss the design of existing drug delivery systems and highlight some of the research into combining drug delivery with existing ocular medical devices.
Collapse
Affiliation(s)
- Victoria R Kearns
- Clinical Engineering and Ophthalmology, School of Clinical Sciences, University of Liverpool, Daulby Street, Liverpool, L69 3GA, UK
| | | |
Collapse
|
141
|
Naturally occurring animal models with outer retina phenotypes. Vision Res 2009; 49:2636-52. [PMID: 19375447 DOI: 10.1016/j.visres.2009.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/07/2009] [Accepted: 04/07/2009] [Indexed: 01/28/2023]
Abstract
Naturally occurring and laboratory generated animal models serve as powerful tools with which to investigate the etiology of human retinal degenerations, especially retinitis pigmentosa (RP), Leber congenital amaurosis (LCA), cone dystrophies (CD) and macular degeneration (MD). Much progress has been made in elucidating gene defects underlying disease, in understanding mechanisms leading to disease, and in designing molecules for translational research and gene-based therapy to interfere with the progression of disease. Key to this progress has been study of naturally occurring murine and canine retinal degeneration mutants. This article will review the history, phenotypes and gene defects of select animal models with outer retina (photoreceptor and retinal pigment epithelium) degeneration phenotypes.
Collapse
|
142
|
Chen FK, Uppal GS, MacLaren RE, Coffey PJ, Rubin GS, Tufail A, Aylward GW, Da Cruz L. Long-term visual and microperimetry outcomes following autologous retinal pigment epithelium choroid graft for neovascular age-related macular degeneration. Clin Exp Ophthalmol 2009; 37:275-85. [DOI: 10.1111/j.1442-9071.2009.01915.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
143
|
Gong L, Wu Q, Song B, Lu B, Zhang Y. Differentiation of rat mesenchymal stem cells transplanted into the subretinal space of sodium iodate-injected rats. Clin Exp Ophthalmol 2009; 36:666-71. [PMID: 18983552 DOI: 10.1111/j.1442-9071.2008.01857.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE The differentiation of rat bone marrow mesenchymal stem cells (MSCs) was investigated in a retinal pigment epithelium (RPE) damage model induced by the administration of sodium iodate. METHODS Cultured rat MSCs were transfected with enhanced green fluorescent protein and transplanted into the subretinal space of rats injected 4 days earlier with sodium iodate. Immunofluorescence analysis was performed 5 weeks later. RESULTS The transduction efficiency was 99.9%. Viable MSCs were detected 5 weeks after transplantation, mainly in the subretinal space. The cells expressed pan-cytokeratin, glial fibrillary acidic protein and rhodopsin. CONCLUSIONS Bone marrow MSCs transplanted into the subretinal space of sodium iodate-injected rats have the ability to differentiate into RPE, photoreceptor and glial lineage cells.
Collapse
Affiliation(s)
- Lihua Gong
- Department of Ophthalmology, Affiliated Sixth People's Hospital Shanghai Jiaotong University, Shanghai, China
| | | | | | | | | |
Collapse
|
144
|
Sheridan CM, Mason S, Pattwell DM, Kent D, Grierson I, Williams R. Replacement of the RPE monolayer. Eye (Lond) 2009; 23:1910-5. [DOI: 10.1038/eye.2008.420] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
145
|
Aoki H, Hara A, Motohashi T, Chem H, Kunisada T. Iris as a recipient tissue for pigment cells: organized in vivo differentiation of melanocytes and pigmented epithelium derived from embryonic stem cells in vitro. Dev Dyn 2009; 237:2394-404. [PMID: 18729218 DOI: 10.1002/dvdy.21656] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Regenerative transplantation of embryonic stem (ES) cell-derived melanocytes into adult tissues, especially skin that includes hair follicles or the hair follicle itself, generally not possible, whereas that of ES cell-derived pigmented epithelium was reported previously. We investigated the in vivo differentiation of these two pigment cell types derived from ES cells after their transfer into the iris. Melanocytes derived from ES cells efficiently integrated into the iris and expanded to fill the stromal layer of the iris, like those prepared from neonatal skin. Transplanted pigmented epithelium from either ES cells or the neonatal eye was also found to be integrated into the iris. Both types of these regenerated pigment cells showed the correct morphology. Regenerated pigment epithelium expressed its functional marker. Functional blocking of signals required for melanocyte development abolished the differentiation of transplanted melanocytes. These results indicate successful in vivo regenerative transfer of pigment cells induced from ES cells in vitro.
Collapse
Affiliation(s)
- Hitomi Aoki
- Department of Tissue and Organ Development, Regeneration, and Advanced Medical Science, Gifu University Graduate School of Medicine, Gifu, Japan
| | | | | | | | | |
Collapse
|
146
|
Nöjd N, Ilmarinen T, Lehtonen L, Skottman H, Suuronen R, Hyttinen J. Using MEA system in verifying the functionality of retinal pigment epithelium cells differentiated from human embryonic stem cells. IFMBE PROCEEDINGS 2009. [DOI: 10.1007/978-3-540-89208-3_547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
147
|
Vitreoretinale Eingriffe bei fortgeschrittener altersabhängiger Makuladegeneration. SPEKTRUM DER AUGENHEILKUNDE 2008. [DOI: 10.1007/s00717-008-0302-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
148
|
Retinal degeneration processes and transplantation of retinal pigment epithelial cells: past, present and future trends. SPEKTRUM DER AUGENHEILKUNDE 2008. [DOI: 10.1007/s00717-008-0292-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
149
|
The genomic response of the retinal pigment epithelium to light damage and retinal detachment. J Neurosci 2008; 28:9880-9. [PMID: 18815272 DOI: 10.1523/jneurosci.2401-08.2008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The retinal pigment epithelium (RPE) plays an essential role in maintaining the health of the retina. The RPE is also the site of pathologic processes in a wide variety of retinal disorders including monogenic retinal dystrophies, age-related macular degeneration, and retinal detachment. Despite intense interest in the RPE, little is known about its molecular response to ocular damage or disease. We have conducted a comprehensive analysis of changes in transcript abundance (the "genomic response") in the murine RPE after light damage. Several dozen transcripts, many related to cell-cell signaling, show significant increases in abundance in response to bright light; transcripts encoding visual cycle proteins show a decrease in abundance. Similar changes are induced by retinal detachment. Environmental and genetic perturbations that modulate the RPE response to bright light suggest that this response is controlled by the retina. In contrast to the response to bright light, the RPE response to retinal detachment overrides these modulatory affects.
Collapse
|
150
|
Thumann G, Viethen A, Gaebler A, Walter P, Kaempf S, Johnen S, Salz AK. The in vitro and in vivo behaviour of retinal pigment epithelial cells cultured on ultrathin collagen membranes. Biomaterials 2008; 30:287-94. [PMID: 18929407 DOI: 10.1016/j.biomaterials.2008.09.039] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 09/02/2008] [Indexed: 11/19/2022]
Abstract
The transplantation of pigment epithelial cells as a therapeutic modality for retinal degeneration requires that the transplanted cells form a monolayer in the subretinal space that will establish communication with photoreceptors. Since previous studies have shown that transplanted cells in suspension do not form a monolayer, it will be necessary to transplant preformed pigment epithelial cell monolayers at the location of the exposed photoreceptors. To establish cell monolayers, retinal pigment epithelial (RPE) cells were cultured on ultrathin collagen membranes. Cells were examined for morphology, for characteristics of differentiation and viability. Membrane degradation and long-term biocompatibility in vivo were assessed following subconjunctival and subretinal implantation in rabbits. These studies have shown that RPE cells adhere, proliferate, form monolayers, and acquire differentiated properties on a collagen membrane that has features similar to Bruch's membrane. Membranes transplanted subconjunctivally and subretinally exhibit excellent biocompatibility without any evidence of inflammation or rejection. RPE cells cultured on collagen membranes acquire differentiated characteristics similar to those of RPE cells in vivo and form complete monolayers that are amenable to be transplanted to the subretinal space. The collagen membranes are non-toxic and do not elicit any rejection or inflammatory response when implanted subconjunctivally or subretinally in rabbits.
Collapse
Affiliation(s)
- Gabriele Thumann
- Department of Ophthalmology, RWTH Aachen University, Pauwelsstrasse 30, 52074 Aachen, Germany.
| | | | | | | | | | | | | |
Collapse
|