1
|
Nishikiori N, Watanabe M, Sato T, Umetsu A, Higashide M, Furuhashi M, Ohguro H. Intraocular fatty acids induce reinforcement of barrier functions on the outer blood-retinal barrier. Prostaglandins Leukot Essent Fatty Acids 2024; 202:102637. [PMID: 39128394 DOI: 10.1016/j.plefa.2024.102637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/17/2024] [Accepted: 08/06/2024] [Indexed: 08/13/2024]
Abstract
The aim of the present study was to elucidate unknown effects of intraocular fatty acids (ioFAs) including palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), arachidonic acid (C20:4), eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6) on the outer blood-retinal barrier (oBRB). For this purpose, human retinal pigment epithelium cell line ARPE19 was subjected to analyses for evaluating the following biological phenotypes: (1) cell viability, (2) cellular metabolic functions, (3) barrier functions by trans-epithelial electrical resistance (TEER), and (4) expression of tight junction (TJ) molecules. In the presence of 100 nM ioFAs, no significant effects on cell viability of ARPE19 cells was observed. While treatment with EPA or DHA tended to reduce non-mitochondrial oxygen consumption, most indices in mitochondrial functions were not markedly affected by treatment with ioFAs in ARPE19 cells. On the other hand, ioFAs except for palmitic acid and stearic acid significantly increased basal extracellular acidification rates, suggesting activated glycolysis or increased lactate production. Interestingly, TEER values of planar ARPE19 monolayer were significantly increased by treatment any ioFAs. Consistently, gene expression levels of TJ proteins were increased by treatment with ioFAs. Collectively, the findings presented herein suggest that ioFAs may contribute to reinforcement of barrier functions of the oBRB albeit there are some differences in biological effects depending on the type of ioFAs.
Collapse
Affiliation(s)
- Nami Nishikiori
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Japan
| | - Megumi Watanabe
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Japan
| | - Tatsuya Sato
- Department ofCardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Japan; Department ofCellular Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Japan
| | - Araya Umetsu
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Japan
| | - Megumi Higashide
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Japan
| | - Masato Furuhashi
- Department ofCardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Japan
| | - Hiroshi Ohguro
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Japan.
| |
Collapse
|
2
|
Rzhanova LA, Markitantova YV, Aleksandrova MA. Recent Achievements in the Heterogeneity of Mammalian and Human Retinal Pigment Epithelium: In Search of a Stem Cell. Cells 2024; 13:281. [PMID: 38334673 PMCID: PMC10854871 DOI: 10.3390/cells13030281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/23/2024] [Accepted: 02/01/2024] [Indexed: 02/10/2024] Open
Abstract
Retinal pigment epithelium (RPE) cells are important fundamentally for the development and function of the retina. In this regard, the study of the morphological and molecular properties of RPE cells, as well as their regenerative capabilities, is of particular importance for biomedicine. However, these studies are complicated by the fact that, despite the external morphological similarity of RPE cells, the RPE is a population of heterogeneous cells, the molecular genetic properties of which have begun to be revealed by sequencing methods only in recent years. This review carries out an analysis of the data from morphological and molecular genetic studies of the heterogeneity of RPE cells in mammals and humans, which reveals the individual differences in the subpopulations of RPE cells and the possible specificity of their functions. Particular attention is paid to discussing the properties of "stemness," proliferation, and plasticity in the RPE, which may be useful for uncovering the mechanisms of retinal diseases associated with pathologies of the RPE and finding new ways of treating them.
Collapse
Affiliation(s)
| | - Yuliya V. Markitantova
- Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, 26 Vavilov Street, 119334 Moscow, Russia; (L.A.R.); (M.A.A.)
| | | |
Collapse
|
3
|
Shelton DA, Gefke I, Summers V, Kim YK, Yu H, Getz Y, Ferdous S, Donaldson K, Liao K, Papania JT, Chrenek MA, Boatright JH, Nickerson JM. Age-Related RPE changes in Wildtype C57BL/6J Mice between 2 and 32 Months. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.574142. [PMID: 38352604 PMCID: PMC10862734 DOI: 10.1101/2024.01.30.574142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Purpose This study provides a systematic evaluation of age-related changes in RPE cell structure and function using a morphometric approach. We aim to better capture nuanced predictive changes in cell heterogeneity that reflect loss of RPE integrity during normal aging. Using C57BL6/J mice ranging from P60-P730, we sought to evaluate how regional changes in RPE shape reflect incremental losses in RPE cell function with advancing age. We hypothesize that tracking global morphological changes in RPE is predictive of functional defects over time. Methods We tested three groups of C57BL/6J mice (young: P60-180; Middle-aged: P365-729; aged: 730+) for function and structural defects using electroretinograms, immunofluorescence, and phagocytosis assays. Results The largest changes in RPE morphology were evident between the young and aged groups, while the middle-aged group exhibited smaller but notable region-specific differences. We observed a 1.9-fold increase in cytoplasmic alpha-catenin expression specifically in the central-medial region of the eye between the young and aged group. There was an 8-fold increase in subretinal, IBA-1-positive immune cell recruitment and a significant decrease in visual function in aged mice compared to young mice. Functional defects in the RPE corroborated by changes in RPE phagocytotic capacity. Conclusions The marked increase of cytoplasmic alpha-catenin expression and subretinal immune cell deposition, and decreased visual output coincide with regional changes in RPE cell morphometrics when stratified by age. These cumulative changes in the RPE morphology showed predictive regional patterns of stress associated with loss of RPE integrity.
Collapse
Affiliation(s)
- Debresha A. Shelton
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Isabelle Gefke
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Vivian Summers
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Yong-Kyu Kim
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Department of Ophthalmology, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul, South Korea
| | - Hanyi Yu
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Department of Computer Science, Emory University, Atlanta, Georgia, United States
| | - Yana Getz
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Salma Ferdous
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, United States
| | - Kevin Donaldson
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Kristie Liao
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Jack T. Papania
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
| | - John M. Nickerson
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| |
Collapse
|
4
|
Santhanam A, Shihabeddin E, Wei H, Wu J, O'Brien J. Molecular basis of retinal remodeling in a zebrafish model of retinitis pigmentosa. Cell Mol Life Sci 2023; 80:362. [PMID: 37979052 PMCID: PMC10657301 DOI: 10.1007/s00018-023-05021-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 10/10/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
A hallmark of inherited retinal degenerative diseases such as retinitis pigmentosa (RP) is progressive structural and functional remodeling of the remaining retinal cells as photoreceptors degenerate. Extensive remodeling of the retina stands as a barrier for the successful implementation of strategies to restore vision. To understand the molecular basis of remodeling, we performed analyses of single-cell transcriptome data from adult zebrafish retina of wild type AB strain (WT) and a P23H mutant rhodopsin transgenic model of RP with continuous degeneration and regeneration. Retinas from both female and male fish were pooled to generate each library, combining data from both sexes. We provide a benchmark atlas of retinal cell type transcriptomes in zebrafish and insight into how each retinal cell type is affected in the P23H model. Oxidative stress is found throughout the retina, with increases in reliance on oxidative metabolism and glycolysis in the affected rods as well as cones, bipolar cells, and retinal ganglion cells. There is also transcriptional evidence for widespread synaptic remodeling and enhancement of glutamatergic transmission in the inner retina. Notably, changes in circadian rhythm regulation are detected in cones, bipolar cells, and retinal pigmented epithelium. We also identify the transcriptomic signatures of retinal progenitor cells and newly formed rods essential for the regenerative process. This comprehensive transcriptomic analysis provides a molecular road map to understand how the retina remodels in the context of chronic retinal degeneration with ongoing regeneration.
Collapse
Affiliation(s)
- Abirami Santhanam
- Department of Ophthalmology & Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
- University of Houston College of Optometry, Houston, TX, 77204, USA.
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Eyad Shihabeddin
- Department of Ophthalmology & Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
- MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
| | - Haichao Wei
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Jiaqian Wu
- MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA
- Department of Neurosurgery, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - John O'Brien
- Department of Ophthalmology & Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA.
- University of Houston College of Optometry, Houston, TX, 77204, USA.
- MD Anderson UT Health Graduate School of Biomedical Sciences, Houston, TX, 77030, USA.
| |
Collapse
|
5
|
Blasiak J, Chojnacki J, Szczepanska J, Fila M, Chojnacki C, Kaarniranta K, Pawlowska E. Epigallocatechin-3-Gallate, an Active Green Tea Component to Support Anti-VEGFA Therapy in Wet Age-Related Macular Degeneration. Nutrients 2023; 15:3358. [PMID: 37571296 PMCID: PMC10421466 DOI: 10.3390/nu15153358] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/19/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
Age-related macular degeneration (AMD) is a largely incurable disease and an emerging problem in aging societies. It occurs in two forms, dry and wet (exudative, neovascular), which may cause legal blindness and sight loss. Currently, there is not any effective treatment for dry AMD. Meanwhile, repeated intravitreal injections with antibodies effective against vascular endothelial growth factor A (VEGFA) slow down wet AMD progression but are not free from complications. (-)-Epigallocatechin-3-gallate (EGCG) is an active compound of green tea, which exerts many beneficial effects in the retinal pigment epithelium and the neural retina. It has been reported to downregulate the VEGFA gene by suppressing its activators. The inhibition of mitogen-activated protein kinases 1 and 3 (MAPK1 and MAPK3) may lie behind the antiangiogenic action of EGCG mediated by VEGFA. EGCG exerts protective effects against UV-induced damage to retinal cells and improves dysfunctional autophagy. EGCG may also interact with the mechanistic target rapamycin (MTOR) and unc-51-like autophagy activating kinase (ULK1) to modulate the interplay between autophagy and apoptosis. Several other studies report beneficial effects of EGCG on the retina that may be related to wet AMD. Therefore, controlled clinical trials are needed to verify whether diet supplementation with EGCG or green tea consumption may improve the results of anti-VEGFA therapy in wet AMD.
Collapse
Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Jan Chojnacki
- Department of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, Poland; (J.C.); (C.C.)
| | - Joanna Szczepanska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-217 Lodz, Poland; (J.S.); (E.P.)
| | - Michal Fila
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland;
| | - Cezary Chojnacki
- Department of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, Poland; (J.C.); (C.C.)
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, 70210 Kuopio, Finland;
- Department of Ophthalmology, Kuopio University Hospital, 70210 Kuopio, Finland
| | - Elzbieta Pawlowska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-217 Lodz, Poland; (J.S.); (E.P.)
| |
Collapse
|
6
|
Liang Y, Shang S, Gao Y, Zhai J, Cheng X, Yang C, Zhang R. Measurements of Intrinsic Capacity in Older Adults: A Scoping Review and Quality Assessment. J Am Med Dir Assoc 2023; 24:267-276.e2. [PMID: 36332688 DOI: 10.1016/j.jamda.2022.09.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 09/21/2022] [Accepted: 09/24/2022] [Indexed: 11/05/2022]
Abstract
OBJECTIVES This review summarizes the measurements of intrinsic capacity in 5 domains across different studies and evaluates the quality of research papers. DESIGN Scoping review of papers written in English and Chinese published in peer-reviewed journals. SETTING AND PARTICIPANTS The intrinsic capacity of older adults was assessed using the multidomain structure (Cognition, Locomotion, Psychological, Sensory and Vitality) proposed by the World Health Organization. METHODS We searched PubMed, MEDLINE, and Web of Science for papers in English, and CNKI, CBM for papers written in Chinese published until September 13, 2022. Both cross-sectional and cohort studies of multidomain measurements of intrinsic capacity were included. Three independent reviewers appraised the quality of studies, and Cohen's kappa was calculated to determine interrater reliability. Data were listed by author, year, setting, country, age range and number of participants, measurement and calculation of intrinsic capacity, and data acquisition method. RESULTS We included 53 studies. Twenty-one studies were of high quality, 31 studies were of moderate quality, and 1 study was of low quality. Measurements of intrinsic capacity and derivation of the summative index score were heterogeneous. Intrinsic capacity was usually assessed in 4 or 5 domains. Sensory was the most frequently overlooked domain or subdivided into vision and hearing in some studies. Indicators of vitality were the most heterogeneous. We also found consistency in heterogeneous measurements. The most common measurements of cognition, locomotion, and psychological capacity were the Mini-Mental State Examination, Short Physical Performance Battery, and Geriatric Depression Scale respectively. Self-reported questionnaires were commonly adopted in sensory domain. The Mini-Nutritional Assessment and grip strength were the most measured indicators of vitality. CONCLUSIONS AND IMPLICATIONS The focus on capacity and disease should be balanced to better promote healthy aging in older adults. Heterogeneity of intrinsic capacity measurements underscores the need for consensus about standardized measurements and calculation procedures.
Collapse
Affiliation(s)
- Yetian Liang
- The Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, PR China
| | | | - Yaxuan Gao
- The Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, PR China; Hebei Puai Aged Care Ltd. Co., Shijiazhuang, Hebei Province, PR China
| | - Jiahui Zhai
- The Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, PR China
| | - Xiaohan Cheng
- The Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, PR China
| | - Chen Yang
- The Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, PR China
| | - Ruili Zhang
- The Fourth Affiliated Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, PR China.
| |
Collapse
|
7
|
Grigoryan EN. Cell Sources for Retinal Regeneration: Implication for Data Translation in Biomedicine of the Eye. Cells 2022; 11:cells11233755. [PMID: 36497013 PMCID: PMC9738527 DOI: 10.3390/cells11233755] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
The main degenerative diseases of the retina include macular degeneration, proliferative vitreoretinopathy, retinitis pigmentosa, and glaucoma. Novel approaches for treating retinal diseases are based on cell replacement therapy using a variety of exogenous stem cells. An alternative and complementary approach is the potential use of retinal regeneration cell sources (RRCSs) containing retinal pigment epithelium, ciliary body, Müller glia, and retinal ciliary region. RRCSs in lower vertebrates in vivo and in mammals mostly in vitro are able to proliferate and exhibit gene expression and epigenetic characteristics typical for neural/retinal cell progenitors. Here, we review research on the factors controlling the RRCSs' properties, such as the cell microenvironment, growth factors, cytokines, hormones, etc., that determine the regenerative responses and alterations underlying the RRCS-associated pathologies. We also discuss how the current data on molecular features and regulatory mechanisms of RRCSs could be translated in retinal biomedicine with a special focus on (1) attempts to obtain retinal neurons de novo both in vivo and in vitro to replace damaged retinal cells; and (2) investigations of the key molecular networks stimulating regenerative responses and preventing RRCS-related pathologies.
Collapse
Affiliation(s)
- Eleonora N Grigoryan
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| |
Collapse
|
8
|
Lian L, Zhai Y, Wan X, Chen L, Liu Z, Liu R, Li S, Zhou J, Chen Y, Hou L, Li H. Sensitivity of the Dorsal-Central Retinal Pigment Epithelium to Sodium Iodate-Induced Damage Is Associated With Overlying M-Cone Photoreceptors in Mice. Invest Ophthalmol Vis Sci 2022; 63:29. [PMID: 36018572 PMCID: PMC9428360 DOI: 10.1167/iovs.63.9.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Retinal pigment epithelium (RPE) degeneration is a leading cause of blindness in retinal degenerative diseases, but the mechanism of RPE regional degeneration remains largely unknown. This study aims to investigate the sensitivity of RPE to sodium iodate (SI) injury in the dorsal and ventral visual fields in mice and analyze whether overlaying cone photoreceptors regulate the sensitivity of RPE to SI-induced damage. Methods SI was used to induce RPE degeneration in mice. Hematoxylin-eosin staining, immunostaining, and TUNEL assay were used to evaluate retinal degeneration along the dorsal-ventral axis. Flat-mounted and sectional retinal immunostaining were used to analyze the distribution of cones along the dorsoventral axis in C57BL/6, albino, and 129 mice. Electroretinography was used to examine the retinal function. Results Dorsal-central RPE was more sensitive to SI-mediated injury along the dorsal-ventral axis in C57BL/6 mice. Compared with the ventral RPE, the dorsal-central RPE was dominantly covered by M cone photoreceptors in these mice. Interestingly, M cone photoreceptor degeneration was followed by dorsal RPE degeneration under a low dose of SI. Furthermore, the sensitivity of dorsal RPE to a low dose of SI was reduced in both albino and 129 mouse strains with dominant mixed cones instead of M cones in the dorsal visual field. Conclusions These findings suggest that dorsal-central RPE is more sensitive to SI injury and that SI-induced RPE degeneration could be controlled by modifying the dominant overlying cone population in the mouse dorsal retina, thereby highlighting a potential role of M cones in RPE regional degeneration.
Collapse
Affiliation(s)
- Lili Lian
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yifan Zhai
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xuejiao Wan
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Linxin Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Zuimeng Liu
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ruona Liu
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Shijia Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Jiajia Zhou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yu Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| | - Huirong Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, China
| |
Collapse
|
9
|
George SM, Lu F, Rao M, Leach LL, Gross JM. The retinal pigment epithelium: Development, injury responses, and regenerative potential in mammalian and non-mammalian systems. Prog Retin Eye Res 2021; 85:100969. [PMID: 33901682 DOI: 10.1016/j.preteyeres.2021.100969] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/23/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022]
Abstract
Diseases that result in retinal pigment epithelium (RPE) degeneration, such as age-related macular degeneration (AMD), are among the leading causes of blindness worldwide. Atrophic (dry) AMD is the most prevalent form of AMD and there are currently no effective therapies to prevent RPE cell death or restore RPE cells lost from AMD. An intriguing approach to treat AMD and other RPE degenerative diseases is to develop therapies focused on stimulating endogenous RPE regeneration. For this to become feasible, a deeper understanding of the mechanisms underlying RPE development, injury responses and regenerative potential is needed. In mammals, RPE regeneration is extremely limited; small lesions can be repaired by the expansion of adjacent RPE cells, but large lesions cannot be repaired as remaining RPE cells are unable to functionally replace lost RPE tissue. In some injury paradigms, RPE cells proliferate but do not regenerate a morphologically normal monolayer, while in others, proliferation is pathogenic and results in further disruption to the retina. This is in contrast to non-mammalian vertebrates, which possess tremendous RPE regenerative potential. Here, we discuss what is known about RPE formation during development in mammalian and non-mammalian vertebrates, we detail the processes by which RPE cells respond to injury, and we describe examples of RPE-to-retina and RPE-to-RPE regeneration in non-mammalian vertebrates. Finally, we outline barriers to RPE-dependent regeneration in mammals that could potentially be overcome to stimulate a regenerative response from the RPE.
Collapse
Affiliation(s)
- Stephanie M George
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Fangfang Lu
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Mishal Rao
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Lyndsay L Leach
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
10
|
Li H, Yu H, Kim YK, Wang F, Teodoro G, Jiang Y, Nickerson JM, Kong J. Computational Model-Based Estimation of Mouse Eyeball Structure From Two-Dimensional Flatmount Microscopy Images. Transl Vis Sci Technol 2021; 10:25. [PMID: 34004004 PMCID: PMC8088229 DOI: 10.1167/tvst.10.4.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/17/2021] [Indexed: 11/25/2022] Open
Abstract
Purpose Retinal pigment epithelial (RPE) cells serve as a supporter for the metabolism and visual function of photoreceptors and a barrier for photoreceptor protection. Morphology dynamics, spatial organization, distribution density, and growth patterns of RPE cells are important for further research on these RPE main functions. To enable such investigations within the authentic eyeball structure, a new method for estimating the three-dimensional (3D) eyeball sphere from two-dimensional tissue flatmount microscopy images was investigated. Methods An error-correction term was formulated to compensate for the reconstruction error as a result of tissue distortions. The effect of the tissue-distortion error was evaluated by excluding partial data points from the low- and high-latitude zones. The error-correction parameter was learned automatically using a set of samples with the ground truth eyeball diameters measured with noncontact light-emitting diode micrometry at submicron accuracy and precision. Results The analysis showed that the error-correction term in the reconstruction model is a valid method for modeling tissue distortions in the tissue flatmount preparation steps. With the error-correction model, the average relative error of the estimated eyeball diameter was reduced from 14% to 5%, and the absolute error was reduced from 0.22 to 0.03 mm. Conclusions A new method for enabling RPE morphometry analysis with respect to locations on an eyeball sphere was created, an important step in increasing RPE research and eye disease diagnosis. Translational Relevance This method enables one to derive RPE cell information from the 3D eyeball surface and helps characterize eyeball volume growth patterns under diseased conditions.
Collapse
Affiliation(s)
- Hongxiao Li
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, USA
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China
| | - Hanyi Yu
- Department of Computer Science, Emory University, Atlanta, GA, USA
| | - Yong-Kyu Kim
- Department of Ophthalmology, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul, South Korea
| | - Fusheng Wang
- Department of Computer Science, Stony Brook University, Stony Brook, NY, USA
| | - George Teodoro
- Department of Computer Science, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Yi Jiang
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, USA
| | | | - Jun Kong
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA, USA
- Department of Computer Science, Emory University, Atlanta, GA, USA
| |
Collapse
|
11
|
Kim YK, Yu H, Summers VR, Donaldson KJ, Ferdous S, Shelton D, Zhang N, Chrenek MA, Jiang Y, Grossniklaus HE, Boatright JH, Kong J, Nickerson JM. Morphometric Analysis of Retinal Pigment Epithelial Cells From C57BL/6J Mice During Aging. Invest Ophthalmol Vis Sci 2021; 62:32. [PMID: 33616620 PMCID: PMC7910641 DOI: 10.1167/iovs.62.2.32] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 02/01/2021] [Indexed: 12/19/2022] Open
Abstract
Purpose To quantitatively evaluate the changes in orientation and morphometric features of mouse retinal pigment epithelial (RPE) cells in different regions of the eye during aging. Methods We segmented individual RPE cells from whole RPE flatmount images of C57BL/6J mice (postnatal days 30 to 720) using a machine-learning method and evaluated changes in morphometric features, including our newly developed metric combining alignment and shape of RPE cells during aging. Results Mainly, the anterior part of the RPE sheet grows during aging, while the posterior part remains constant. Changes in size and shape of the peripheral RPE cells are prominent with aging as cells become larger, elongated, and concave. Conversely, the central RPE cells maintain relatively constant size and numbers with aging. Cell count in the central area and the overall cell count (approximately 50,000) were relatively constant over different age groups. RPE cells also present a specific orientation concordance that matches the shape of the specific region of the eyeball. Those cells near the optic disc or equator have a circumferential orientation to cover the round shape of the eyeball, whereas those cells in the periphery have a radial orientation and corresponding radial elongation, the extent of which increases with aging and matches with axial elongation of the eyeball. Conclusions These results suggest that the fluid RPE morphology reflects various growth rates of underlying eyeball, and RPE cells could be classified into four regional classes (near the optic disc, central, equatorial, and peripheral) according to their morphometric features.
Collapse
Affiliation(s)
- Yong-Kyu Kim
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Ophthalmology, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul, South Korea
| | - Hanyi Yu
- Department of Computer Science, Emory University, Atlanta, Georgia, United States
| | - Vivian R. Summers
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Kevin J. Donaldson
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Salma Ferdous
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Debresha Shelton
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Nan Zhang
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Ophthalmology, Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Yi Jiang
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia, United States
| | - Hans E. Grossniklaus
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
| | - Jun Kong
- Department of Computer Science, Emory University, Atlanta, Georgia, United States
- Department of Mathematics and Statistics, Georgia State University, Atlanta, Georgia, United States
- Department of Computer Science, Georgia State University, Atlanta, Georgia, United States
| | - John M. Nickerson
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| |
Collapse
|
12
|
Arranz-Romera A, Hernandez M, Checa-Casalengua P, Garcia-Layana A, Molina-Martinez IT, Recalde S, Young MJ, Tucker BA, Herrero-Vanrell R, Fernandez-Robredo P, Bravo-Osuna I. A Safe GDNF and GDNF/BDNF Controlled Delivery System Improves Migration in Human Retinal Pigment Epithelial Cells and Survival in Retinal Ganglion Cells: Potential Usefulness in Degenerative Retinal Pathologies. Pharmaceuticals (Basel) 2021; 14:ph14010050. [PMID: 33440745 PMCID: PMC7827036 DOI: 10.3390/ph14010050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/23/2020] [Accepted: 01/06/2021] [Indexed: 11/21/2022] Open
Abstract
We assessed the sustained delivery effect of poly (lactic-co-glycolic) acid (PLGA)/vitamin E (VitE) microspheres (MSs) loaded with glial cell-derived neurotrophic factor (GDNF) alone (GDNF-MSs) or combined with brain-derived neurotrophic factor (BDNF; GDNF/BDNF-MSs) on migration of the human adult retinal pigment epithelial cell-line-19 (ARPE-19) cells, primate choroidal endothelial (RF/6A) cells, and the survival of isolated mouse retinal ganglion cells (RGCs). The morphology of the MSs, particle size, and encapsulation efficiencies of the active substances were evaluated. In vitro release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability, terminal deoxynucleotidyl transferase (TdT) deoxyuridine dUTP nick-end labelling (TUNEL) apoptosis, functional wound healing migration (ARPE-19; migration), and (RF/6A; angiogenesis) assays were conducted. The safety of MS intravitreal injection was assessed using hematoxylin and eosin, neuronal nuclei (NeuN) immunolabeling, and TUNEL assays, and RGC in vitro survival was analyzed. MSs delivered GDNF and co-delivered GDNF/BDNF in a sustained manner over 77 days. The BDNF/GDNF combination increased RPE cell migration, whereas no effect was observed on RF/6A. MSs did not alter cell viability, apoptosis was absent in vitro, and RGCs survived in vitro for seven weeks. In mice, retinal toxicity and apoptosis was absent in histologic sections. This delivery strategy could be useful as a potential co-therapy in retinal degenerations and glaucoma, in line with future personalized long-term intravitreal treatment as different amounts (doses) of microparticles can be administered according to patients’ needs.
Collapse
Affiliation(s)
- Alicia Arranz-Romera
- Pharmaceutical Innovation in Ophthalmology (InnOftal), Research Group (UCM 920415), Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University, Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.A.-R.); (P.C.-C.); (I.T.M.-M.); (R.H.-V.)
| | - Maria Hernandez
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (A.G.-L.); (S.R.); (P.F.-R.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
- Correspondence: (M.H.); (I.B.-O.)
| | - Patricia Checa-Casalengua
- Pharmaceutical Innovation in Ophthalmology (InnOftal), Research Group (UCM 920415), Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University, Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.A.-R.); (P.C.-C.); (I.T.M.-M.); (R.H.-V.)
| | - Alfredo Garcia-Layana
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (A.G.-L.); (S.R.); (P.F.-R.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
| | - Irene T. Molina-Martinez
- Pharmaceutical Innovation in Ophthalmology (InnOftal), Research Group (UCM 920415), Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University, Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.A.-R.); (P.C.-C.); (I.T.M.-M.); (R.H.-V.)
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
- Instituto Universitario de Farmacia Industrial (IUFI), Faculty of Pharmacy, Complutense University, 28040 Madrid, Spain
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain
| | - Sergio Recalde
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (A.G.-L.); (S.R.); (P.F.-R.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
| | - Michael J. Young
- Department of Ophthalmology, Schepens Eye Research Institute, Harvard Medical School, Harvard University, 20 Staniford Street, Boston, MA 02114, USA;
| | - Budd A. Tucker
- Institute for Vision Research, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA 52242, USA;
| | - Rocío Herrero-Vanrell
- Pharmaceutical Innovation in Ophthalmology (InnOftal), Research Group (UCM 920415), Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University, Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.A.-R.); (P.C.-C.); (I.T.M.-M.); (R.H.-V.)
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
- Instituto Universitario de Farmacia Industrial (IUFI), Faculty of Pharmacy, Complutense University, 28040 Madrid, Spain
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain
| | - Patricia Fernandez-Robredo
- Retinal Pathologies and New Therapies Group, Experimental Ophthalmology Laboratory, Department of Ophthalmology, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (A.G.-L.); (S.R.); (P.F.-R.)
- Navarra Institute for Health Research, IdiSNA, 31008 Pamplona, Spain
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
| | - Irene Bravo-Osuna
- Pharmaceutical Innovation in Ophthalmology (InnOftal), Research Group (UCM 920415), Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University, Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain; (A.A.-R.); (P.C.-C.); (I.T.M.-M.); (R.H.-V.)
- Red Temática de Investigación Cooperativa Sanitaria en Enfermedades Oculares (Oftared), 31008 Pamplona, Spain
- Instituto Universitario de Farmacia Industrial (IUFI), Faculty of Pharmacy, Complutense University, 28040 Madrid, Spain
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Plaza de Ramón y Cajal, s/n, 28040 Madrid, Spain
- Correspondence: (M.H.); (I.B.-O.)
| |
Collapse
|
13
|
Yang M, So KF, Lam WC, Lo ACY. Novel Programmed Cell Death as Therapeutic Targets in Age-Related Macular Degeneration? Int J Mol Sci 2020; 21:E7279. [PMID: 33019767 PMCID: PMC7582463 DOI: 10.3390/ijms21197279] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/29/2020] [Accepted: 09/29/2020] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of severe visual loss among the elderly. AMD patients are tormented by progressive central blurring/loss of vision and have limited therapeutic options to date. Drusen accumulation causing retinal pigment epithelial (RPE) cell damage is the hallmark of AMD pathogenesis, in which oxidative stress and inflammation are the well-known molecular mechanisms. However, the underlying mechanisms of how RPE responds when exposed to drusen are still poorly understood. Programmed cell death (PCD) plays an important role in cellular responses to stress and the regulation of homeostasis and diseases. Apart from the classical apoptosis, recent studies also discovered novel PCD pathways such as pyroptosis, necroptosis, and ferroptosis, which may contribute to RPE cell death in AMD. This evidence may yield new treatment targets for AMD. In this review, we summarized and analyzed recent advances on the association between novel PCD and AMD, proposing PCD's role as a therapeutic new target for future AMD treatment.
Collapse
Affiliation(s)
- Ming Yang
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (M.Y.); (K.-F.S.)
| | - Kwok-Fai So
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (M.Y.); (K.-F.S.)
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
| | - Wai Ching Lam
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (M.Y.); (K.-F.S.)
| | - Amy Cheuk Yin Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (M.Y.); (K.-F.S.)
| |
Collapse
|
14
|
Gu J, Wang Y, Cui Z, Li H, Li S, Yang X, Yan X, Ding C, Tang S, Chen J. The Construction of Retinal Pigment Epithelium Sheets with Enhanced Characteristics and Cilium Assembly Using iPS Conditioned Medium and Small Incision Lenticule Extraction Derived Lenticules. Acta Biomater 2019; 92:115-131. [PMID: 31075513 DOI: 10.1016/j.actbio.2019.05.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 04/18/2019] [Accepted: 05/06/2019] [Indexed: 01/06/2023]
Abstract
In vitro generation of a functional retinal pigment epithelium (RPE) monolayer sheet is useful and promising for RPE cell therapy. Here, for the first time, we used induced pluripotent stem (iPS) supernatant as the conditioned medium (iPS-CM) and femtosecond laser intrastromal lenticule (FLI-lenticule) as a scaffold to construct an engineered RPE sheet. There are significant enhancements in RPE cell density, transepithelial electrical resistance (TER) and inhibitions of ultraviolet C (UVC)-irradiated apoptosis when RPE cells are cultured in iPS supernatant/Dulbecco's modified Eagle's medium (DMEM)-F12 of 1/2 (iPS-CM) compared with those in normal medium (NM, DMEM-F12). Using the assay of a panel of cytokines, combined with transcriptome and protein analyses, we discover that iPS-CM contains high levels of platelet-derived growth factor AA (PDGF-AA), insulin-like growth factor binding protein (IGFBP)-2, transforming growth factor (TGF)-α and IGFBP-6, which are responsible for the upregulation of gene and protein markers with RPE phenotypes and downregulation of gene and protein markers with epithelial-mesenchymal transition (EMT) phenotypes for RPE cells in iPS-CM when compared to those in NM. Moreover, compared to cultures on tissue culture plates (TCP), RPE cells on FLI-lenticule display more microvilli and cilium in accordance with the results in terms of RNA-Seq data, quantitative polymerase chain reaction (qPCR) expression, immunofluorescence staining, and western blot assays. Furthermore, acellular FLI-lenticule exhibits biocompatibility after rabbit subretinal implantation by 30 days through electroretinography and histological examination. Thus, we determined that engineered RPE sheets treated by iPS-CM in conjunction with FLI-lenticule scaffold aid in enhanced RPE characteristics and cilium assembly. Such a strategy to construct RPE sheets is a promising avenue for developing RPE cell therapy, disease models and drug screening tools. STATEMENT OF SIGNIFICANCE: In vitro generation of a functional RPE monolayer sheet is useful and promising for RPE cell therapy. Here, we constructed engineered RPE sheets treated by iPS-CM in conjunction with FLI-lenticule scaffolds to help in enhanced RPE characteristics and cilium assembly. Such a strategy to generate RPE sheets is a promising avenue for developing RPE cell therapy, disease models and drug screening tools.
Collapse
Affiliation(s)
- Jianing Gu
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China; Aier Eye Institute, Changsha 410015, Hunan Province, PR China
| | - Yini Wang
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China; Aier Eye Institute, Changsha 410015, Hunan Province, PR China
| | - Zekai Cui
- Aier Eye Institute, Changsha 410015, Hunan Province, PR China
| | - Hong Li
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China
| | - Shenyang Li
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China
| | - Xu Yang
- Aier Eye Institute, Changsha 410015, Hunan Province, PR China
| | - Xin Yan
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China
| | - Chengcheng Ding
- Aier Eye Institute, Changsha 410015, Hunan Province, PR China
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China; Aier Eye Institute, Changsha 410015, Hunan Province, PR China.
| | - Jiansu Chen
- Aier School of Ophthalmology, Central South University, Changsha 410015, Hunan, PR China; Aier Eye Institute, Changsha 410015, Hunan Province, PR China; Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou 510632, PR China; Institute of Ophthalmology, Medical College, Jinan University, Guangzhou 510632, PR China.
| |
Collapse
|
15
|
McGill TJ, Osborne L, Lu B, Stoddard J, Huhn S, Tsukamoto A, Capela A. Subretinal Transplantation of Human Central Nervous System Stem Cells Stimulates Controlled Proliferation of Endogenous Retinal Pigment Epithelium. Transl Vis Sci Technol 2019; 8:43. [PMID: 31245172 PMCID: PMC6586077 DOI: 10.1167/tvst.8.3.43] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/26/2019] [Indexed: 12/03/2022] Open
Abstract
Purpose The loss of retinal pigment epithelial (RPE) cells is a feature common to age-related macular degeneration (AMD) and retinitis pigmentosa (RP) and multiple early phase clinical trials are underway testing the safety of RPE cell replacement for these diseases. We examined whether transplantation of human neural stem cells into the subretinal space could enhance the endogenous proliferative capacity of the host RPE cell to regenerate. Methods Human central nervous system stem cells (HuCNS-SC) were isolated from enzymatically treated brain tissue using flow cytometry. Pigmented dystrophic Royal College of Surgeons (RCS) and S334ter-4 rats treated with oral bromodeoxyuridine (BrdU) received a unilateral subretinal injection of 1.0 × 105 HuCNS-SC cells at either postnatal day 21 or 60. Animals were sacrificed at 90, 120, and 150 days of age. Eyes were fixed processed for cryostat sectioning. Sections were immunostained with Stem101, Ku80, RPE65, OTX1/2, BrdU, and CRALBP antibodies and analyzed via confocal microscopy. Results RCS rats that received transplantation of HuCNS-SC had significantly more (approximately 3-fold) Ki67-positive or BrdU-labelled host RPE cells adjacent to the HuCNS-SC graft than controls. Significantly increased host RPE cell proliferation as a result of HuCNS-SC transplantation also was confirmed in S334ter-line 4 transgenic rats with higher proliferation observed in animals with longer posttransplantation periods. Conclusions These results suggest that controlled proliferation of endogenous RPE by HuCNS-SC may provide another mechanism by which RPE cell diseases could be treated. Translational Relevance Engaging the capacity for endogenous RPE cell regeneration in atrophic diseases may be a novel therapeutic strategy for degenerative diseases of the RPE and retina.
Collapse
Affiliation(s)
- Trevor J McGill
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA.,Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | | | - Bin Lu
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Jonathan Stoddard
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, USA
| | | | - Ann Tsukamoto
- StemCells, Inc., Newark, CA, USA.,Current address: BOCO Silicon Valley, Palo Alto, CA, USA
| | | |
Collapse
|
16
|
Sharif U, Mahmud NM, Kay P, Yang YC, Harding SP, Grierson I, Kamalden TA, Jackson MJ, Paraoan L. Advanced glycation end products-related modulation of cathepsin L and NF-κB signalling effectors in retinal pigment epithelium lead to augmented response to TNFα. J Cell Mol Med 2018; 23:405-416. [PMID: 30338926 PMCID: PMC6307775 DOI: 10.1111/jcmm.13944] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/07/2018] [Accepted: 09/10/2018] [Indexed: 01/02/2023] Open
Abstract
The retinal pigment epithelium (RPE) plays a central role in neuroretinal homoeostasis throughout life. Altered proteolysis and inflammatory processes involving RPE contribute to the pathophysiology of age‐related macular degeneration (AMD), but the link between these remains elusive. We report for the first time the effect of advanced glycation end products (AGE)—known to accumulate on the ageing RPE's underlying Bruch's membrane in situ—on both key lysosomal cathepsins and NF‐κB signalling in RPE. Cathepsin L activity and NF‐κB effector levels decreased significantly following 2‐week AGE exposure. Chemical cathepsin L inhibition also decreased total p65 protein levels, indicating that AGE‐related change of NF‐κB effectors in RPE cells may be modulated by cathepsin L. However, upon TNFα stimulation, AGE‐exposed cells had significantly higher ratio of phospho‐p65(Ser536)/total p65 compared to non‐AGEd controls, with an even higher fold increase than in the presence of cathepsin L inhibition alone. Increased proportion of active p65 indicates an AGE‐related activation of NF‐κB signalling in a higher proportion of cells and/or an enhanced response to TNFα. Thus, NF‐κB signalling modulation in the AGEd environment, partially regulated via cathepsin L, is employed by RPE cells as a protective (para‐inflammatory) mechanism but renders them more responsive to pro‐inflammatory stimuli.
Collapse
Affiliation(s)
- Umar Sharif
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Nur Musfirah Mahmud
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK.,Eye Research Centre, University of Malaya, Kuala Lumpur, Malaysia
| | - Paul Kay
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Yit C Yang
- Ophthalmology, The Royal Wolverhampton NHS Trust, Wolverhampton, UK
| | - Simon P Harding
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Ian Grierson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | | | - Malcolm J Jackson
- Department of Musculoskeletal Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| | - Luminita Paraoan
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK
| |
Collapse
|
17
|
The peripheral eye: A neurogenic area with potential to treat retinal pathologies? Prog Retin Eye Res 2018; 68:110-123. [PMID: 30201383 DOI: 10.1016/j.preteyeres.2018.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/31/2018] [Accepted: 09/03/2018] [Indexed: 12/14/2022]
Abstract
Numerous degenerative diseases affecting visual function, including glaucoma and retinitis pigmentosa, are produced by the loss of different types of retinal cells. Cell replacement therapy has emerged as a promising strategy for treating these and other retinal diseases. The retinal margin or ciliary body (CB) of mammals has been proposed as a potential source of cells to be used in degenerative conditions affecting the retina because it has been reported it might hold neurogenic potential beyond embryonic development. However, many aspects of the origin and biology of the CB are unknown and more recent experiments have challenged the capacity of CB cells to generate different types of retinal neurons. Here we review the most recent findings about the development of the marginal zone of the retina in different vertebrates and some of the mechanisms underlying the proliferative and neurogenic capacity of this fascinating region of the vertebrates eye. In addition, we performed experiments to isolate CB cells from the mouse retina, generated neurospheres and observed that they can be expanded with a proliferative ratio similar to neural stem cells. When induced to differentiate, cells derived from the CB neurospheres start to express early neural markers but, unlike embryonic stem cells, they are not able to fully differentiate in vitro or generate retinal organoids. Together with previous reports on the neurogenic capacity of CB cells, also reviewed here, our results contribute to the current knowledge about the potentiality of this peripheral region of the eye as a therapeutic source of functional retinal neurons in degenerative diseases.
Collapse
|
18
|
Rajapakse D, Chen M, Curtis TM, Xu H. PKCζ-dependent upregulation of p27kip1 contributes to oxidative stress induced retinal pigment epithelial cell multinucleation. Aging (Albany NY) 2018; 9:2052-2068. [PMID: 29016360 PMCID: PMC5680555 DOI: 10.18632/aging.101299] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 09/28/2017] [Indexed: 01/24/2023]
Abstract
Retinal pigment epithelial (RPE) cells increase in size and multinucleate during aging. We have shown using human and mouse cell lines that oxidised photoreceptor outer segments (oxPOS)-induced cytokinesis failure is related to RPE cell multinucleation, although the underlying mechanism remains unknown. This study investigated the role of the PKC pathway in oxPOS-induced RPE multinucleation using ARPE19 cells. oxPOS treatment promoted PKC activity and upregulated the mRNA expression of PKC α, δ, ζ, ι and μ. Inhibition of PKCα with Gö6976 resulted in a 33% reduction of multinucleate ARPE19 cells, whereas inhibition of PKCζ with Gö6983 led to a 50% reduction in multinucleate ARPE19 cells. Furthermore, oxPOS treatment induced a PKCζ-dependent upregulation of the Cdk inhibitor p27kip1, its inhibition using A2CE reduced oxPOS-induced ARPE19 multinucleation. Our results suggest that oxPOS-induced ARPE19 cytokinesis failure is, at least in part, due to the upregulation of p27kip1 through activating the PKC, particularly PKCζ pathway. Targeting the PKCζ-p27kip1 signalling axis may be a novel approach to restore RPE repair capacity during aging.
Collapse
Affiliation(s)
- Dinusha Rajapakse
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, BT97 BL, UK
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, BT97 BL, UK
| | - Tim M Curtis
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, BT97 BL, UK
| | - Heping Xu
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, BT97 BL, UK
| |
Collapse
|
19
|
Loss of Extracellular Signal-Regulated Kinase 1/2 in the Retinal Pigment Epithelium Leads to RPE65 Decrease and Retinal Degeneration. Mol Cell Biol 2017; 37:MCB.00295-17. [PMID: 29038159 PMCID: PMC5705814 DOI: 10.1128/mcb.00295-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/02/2017] [Indexed: 12/19/2022] Open
Abstract
Recent work suggested that the activity of extracellular signal-regulated kinase 1/2 (ERK1/2) is increased in the retinal pigment epithelium (RPE) of age-related macular degeneration (ARMD) patients and therefore could be an attractive therapeutic target. Notably, ERK1/2 pathway inhibitors are used in cancer therapy, with severe and noncharacterized ocular side effects. To decipher the role of ERK1/2 in RPE cells, we conditionally disrupted the Erk1 and Erk2 genes in mouse RPE. The loss of ERK1/2 activity resulted in a significant decrease in the level of RPE65 expression, a decrease in ocular retinoid levels concomitant with low visual function, and a rapid disorganization of RPE cells, ultimately leading to retinal degeneration. Our results identify the ERK1/2 pathway as a direct regulator of the visual cycle and a critical component of the viability of RPE and photoreceptor cells. Moreover, our results caution about the need for a very fine adjustment of kinase inhibition in cancer or ARMD treatment in order to avoid ocular side effects.
Collapse
|
20
|
Ma X, Hua J, Zheng G, Li F, Rao C, Li H, Wang J, Pan L, Hou L. Regulation of cell proliferation in the retinal pigment epithelium: Differential regulation of the death-associated protein like-1 DAPL1 by alternative MITF splice forms. Pigment Cell Melanoma Res 2017; 31:411-422. [PMID: 29171181 DOI: 10.1111/pcmr.12676] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 11/12/2017] [Indexed: 01/12/2023]
Abstract
Vertebrate eye development and homoeostasis critically depend on the regulation of proliferation of cells forming the retinal pigment epithelium (RPE). Previous results indicated that the death-associated protein like-1 DAPL1 cell autonomously suppresses RPE proliferation in vivo and in vitro. Here, we show in human RPE cell lines that the pigment cell transcription factor MITF regulates RPE cell proliferation by upregulating DAPL1 expression. DAPL1 regulation by MITF is, however, mediated predominantly by (-) MITF, one of two alternative splice isoforms of MITF that lacks six residues located upstream of the DNA-binding basic domain. Furthermore, we find that the regulation of DAPL1 by MITF is indirect in that (-) MITF stimulates the transcription of Musashi homolog-2 (MSI2), which negatively regulates the processing of the anti-DAPL1 microRNA miR-7. Our results provide molecular insights into the regulation of RPE cell proliferation and quiescence and may help us understand the mechanisms of normal RPE maintenance and of eye diseases associated with either RPE hyperproliferation or the lack of regenerative proliferation.
Collapse
Affiliation(s)
- Xiaoyin Ma
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Jiajia Hua
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Guoxiao Zheng
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Fang Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Chunbao Rao
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Huirong Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Jing Wang
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Li Pan
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, China
| |
Collapse
|
21
|
Sonoi R, Kim MH, Yamada K, Kino-oka M. Phenotypic heterogeneity of human retinal pigment epithelial cells in passaged cell populations. J Biosci Bioeng 2017; 124:227-233. [DOI: 10.1016/j.jbiosc.2017.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/01/2017] [Accepted: 03/13/2017] [Indexed: 02/09/2023]
|
22
|
Jonas JB, Ohno-Matsui K, Holbach L, Panda-Jonas S. Retinal pigment epithelium cell density in relationship to axial length in human eyes. Acta Ophthalmol 2017; 95:e22-e28. [PMID: 27545271 DOI: 10.1111/aos.13188] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 06/13/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE To assess associations between axial length and density of retinal pigment epithelium (RPE) cells in various ocular regions. METHODS The histomorphometric investigation included histological sections of enucleated eyes of Caucasian patients. Using a light microscope, we counted the number of RPE cells on Bruch's membrane at the ora serrata, in the pre-equatorial region, the equatorial and retro-equatorial region, at the midpoint equator/posterior pole, and at the posterior pole. RESULTS The study included 65 globes with a mean axial length 25.9 ± 3.5 mm (range: 21.0-34.0 mm). Retinal pigment epithelium (RPE) cell count in the equatorial to retro-equatorial region (p < 0.001; correlation coefficient r2 : 0.44), in the pre-equatorial region (p < 0.001; r2 : 0.39) and at the midpoint equator/posterior pole (p = 0.03; r2 : 0.12) decreased with increasing axial length. Retinal pigment epithelium (RPE) cell count at the ora serrata (p = 0.49) and posterior pole (p = 0.44) was not significantly correlated with axial length. As a corollary, mean RPE cell density was higher (p < 0.001) at the posterior pole than at the midpoint equator/posterior pole or at the ora serrata region, where it was higher than in pre-equatorial region (p < 0.001) and in the equatorial to retro-equatorial region (p < 0.001). CONCLUSIONS The decrease in the RPE cell density mainly in the equatorial to retro-equatorial region in association with longer axial length suggests a region of enlargement of Bruch's membrane in the equatorial to retro-equatorial area in association with axial elongation. The finding may be of interest to elucidate the process of emmetropization/myopization.
Collapse
Affiliation(s)
- Jost B. Jonas
- Department of Ophthalmology; Medical Faculty Mannheim; Heidelberg University; Mannheim Germany
| | - Kyoko Ohno-Matsui
- Department of Ophthalmology and Visual Science; Tokyo Medical and Dental University; Tokyo Japan
| | - Leonard Holbach
- Department of Ophthalmology; Friedrich-Alexander University Erlangen-Nürnberg; Erlangen Germany
| | - Songhomitra Panda-Jonas
- Department of Ophthalmology; Medical Faculty Mannheim; Heidelberg University; Mannheim Germany
| |
Collapse
|
23
|
Al-Hussaini H, Kilarkaje N, Shahabi G, Al-Mulla F. Proliferation and Migration of Peripheral Retinal Pigment Epithelial Cells Are Associated with the Upregulation of Wingless-Related Integration and Bone Morphogenetic Protein Signaling in Dark Agouti Rats. Med Princ Pract 2016; 25:408-16. [PMID: 27165129 PMCID: PMC5588433 DOI: 10.1159/000446480] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 04/27/2016] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE The aim of this study was to investigate the possible migration of proliferating peripheral retinal pigment epithelial (RPE) cells and their association with differential gene expressions. MATERIALS AND METHODS The RPE layer was obtained from the inner aspect of the eyeball of dark agouti rats (12-13 weeks old) and was mounted on glass slides. The peripheral RPE cell proliferation was evaluated using bromodeoxyuridine immunohistochemistry (n = 10). The cell migration was examined using the Dil tracer technique (n = 40) at the end of weeks 6, 10, 14 and 18. Affymetrix microarray analysis was used to investigate differential gene expressions in peripheral and central RPE cells, which was authenticated by RT-PCR using 4 RPE-specific genes (n = 10). RESULTS In this study, peripheral RPE cells divided and appeared in clusters, but equatorial and central RPE cells rarely divided. The peripheral RPE cells migrated to the central RPE region in a time-dependent manner up to the end of week 14, but not later. The microarray analysis showed the expression of 9,645 out of a total of 35,220 genes studied. Among the 9,645 genes, 573 were differentially expressed (438 were upregulated and 135 were downregulated) in peripheral RPE cells as compared to central RPE cells. Of these 573 genes, 56 were associated with signaling pathways related to the regulation of cell proliferation, including Pax6, TGFβ, BMP and Wnt, and 404 were associated with pathways of cell migration. CONCLUSIONS In this study, peripheral RPE cells divided and migrated to the central region. This process was associated with differential gene expressions in these cells.
Collapse
Affiliation(s)
| | | | - Golnaz Shahabi
- Department of Institute of Ophthalmology, University College London, London, UK
| | - Fahad Al-Mulla
- Department of Pathology, Faculty of Medicine, Kuwait University, Safat, Kuwait
| |
Collapse
|
24
|
Jones BW, Pfeiffer RL, Ferrell WD, Watt CB, Tucker J, Marc RE. Retinal Remodeling and Metabolic Alterations in Human AMD. Front Cell Neurosci 2016; 10:103. [PMID: 27199657 PMCID: PMC4848316 DOI: 10.3389/fncel.2016.00103] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 04/05/2016] [Indexed: 12/18/2022] Open
Abstract
Age-related macular degeneration (AMD) is a progressive retinal degeneration resulting in central visual field loss, ultimately causing debilitating blindness. AMD affects 18% of Americans from 65 to 74, 30% older than 74 years of age and is the leading cause of severe vision loss and blindness in Western populations. While many genetic and environmental risk factors are known for AMD, we currently know less about the mechanisms mediating disease progression. The pathways and mechanisms through which genetic and non-genetic risk factors modulate development of AMD pathogenesis remain largely unexplored. Moreover, current treatment for AMD is palliative and limited to wet/exudative forms. Retina is a complex, heterocellular tissue and most retinal cell classes are impacted or altered in AMD. Defining disease and stage-specific cytoarchitectural and metabolic responses in AMD is critical for highlighting targets for intervention. The goal of this article is to illustrate cell types impacted in AMD and demonstrate the implications of those changes, likely beginning in the retinal pigment epithelium (RPE), for remodeling of the the neural retina. Tracking heterocellular responses in disease progression is best achieved with computational molecular phenotyping (CMP), a tool that enables acquisition of a small molecule fingerprint for every cell in the retina. CMP uncovered critical cellular and molecular pathologies (remodeling and reprogramming) in progressive retinal degenerations such as retinitis pigmentosa (RP). We now applied these approaches to normal human and AMD tissues mapping progression of cellular and molecular changes in AMD retinas, including late-stage forms of the disease.
Collapse
Affiliation(s)
- Bryan W Jones
- Department of Ophthalmology, Moran Eye Center, University of Utah Salt Lake City, UT, USA
| | - Rebecca L Pfeiffer
- Department of Ophthalmology, Moran Eye Center, University of UtahSalt Lake City, UT, USA; Interdepartmental Program in Neuroscience, University of UtahSalt Lake City, UT, USA
| | - William D Ferrell
- Department of Ophthalmology, Moran Eye Center, University of Utah Salt Lake City, UT, USA
| | - Carl B Watt
- Department of Ophthalmology, Moran Eye Center, University of Utah Salt Lake City, UT, USA
| | - James Tucker
- Department of Ophthalmology, University of California, Davis Davis, CA, USA
| | - Robert E Marc
- Department of Ophthalmology, Moran Eye Center, University of Utah Salt Lake City, UT, USA
| |
Collapse
|
25
|
Choudhary P, Gutteridge A, Impey E, Storer RI, Owen RM, Whiting PJ, Bictash M, Benn CL. Targeting the cAMP and Transforming Growth Factor-β Pathway Increases Proliferation to Promote Re-Epithelialization of Human Stem Cell-Derived Retinal Pigment Epithelium. Stem Cells Transl Med 2016; 5:925-37. [PMID: 27112176 DOI: 10.5966/sctm.2015-0247] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 02/01/2016] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Retinal pigment epithelium (RPE) cell integrity is critical to the maintenance of retinal function. Many retinopathies such as age-related macular degeneration (AMD) are caused by the degeneration or malfunction of the RPE cell layer. Replacement of diseased RPE with healthy, stem cell-derived RPE is a potential therapeutic strategy for treating AMD. Human embryonic stem cells (hESCs) differentiated into RPE progeny have the potential to provide an unlimited supply of cells for transplantation, but challenges around scalability and efficiency of the differentiation process still remain. Using hESC-derived RPE as a cellular model, we sought to understand mechanisms that could be modulated to increase RPE yield after differentiation. We show that RPE epithelialization is a density-dependent process, and cells seeded at low density fail to epithelialize. We demonstrate that activation of the cAMP pathway increases proliferation of dissociated RPE in culture, in part through inhibition of transforming growth factor-β (TGF-β) signaling. This results in enhanced uptake of epithelial identity, even in cultures seeded at low density. In line with these findings, targeted manipulation of the TGF-β pathway with small molecules produces an increase in efficiency of RPE re-epithelialization. Taken together, these data highlight mechanisms that promote epithelial fate acquisition in stem cell-derived RPE. Modulation of these pathways has the potential to favorably impact scalability and clinical translation of hESC-derived RPE as a cell therapy. SIGNIFICANCE Stem cell-derived retinal pigment epithelium (RPE) is currently being evaluated as a cell-replacement therapy for macular degeneration. This work shows that the process of generating RPE in vitro is regulated by the cAMP and transforming growth factor-β signaling pathway. Modulation of these pathways by small molecules, as identified by phenotypic screening, leads to an increased efficiency of generating RPE cells with a higher yield. This can have a potential impact on manufacturing transplantation-ready cells at large scale and is advantageous for clinical studies using this approach in the future.
Collapse
Affiliation(s)
- Parul Choudhary
- Pfizer Neuroscience and Pain Research Unit, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - Alex Gutteridge
- Pfizer Neuroscience and Pain Research Unit, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - Emma Impey
- Pfizer Neuroscience and Pain Research Unit, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - R Ian Storer
- Pfizer Worldwide Medicinal Chemistry, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - Robert M Owen
- Pfizer Worldwide Medicinal Chemistry, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - Paul J Whiting
- Pfizer Neuroscience and Pain Research Unit, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - Magda Bictash
- Pfizer Neuroscience and Pain Research Unit, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| | - Caroline L Benn
- Pfizer Neuroscience and Pain Research Unit, Pfizer Ltd., Great Abington, Cambridge, United Kingdom
| |
Collapse
|
26
|
Lamoke F, Shaw S, Yuan J, Ananth S, Duncan M, Martin P, Bartoli M. Increased Oxidative and Nitrative Stress Accelerates Aging of the Retinal Vasculature in the Diabetic Retina. PLoS One 2015; 10:e0139664. [PMID: 26466127 PMCID: PMC4605485 DOI: 10.1371/journal.pone.0139664] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 09/16/2015] [Indexed: 01/12/2023] Open
Abstract
Hyperglycemia-induced retinal oxidative and nitrative stress can accelerate vascular cell aging, which may lead to vascular dysfunction as seen in diabetes. There is no information on whether this may contribute to the progression of diabetic retinopathy (DR). In this study, we have assessed the occurrence of senescence-associated markers in retinas of streptozotocin-induced diabetic rats at 8 and 12 weeks of hyperglycemia as compared to normoglycemic aging (12 and 14 months) and adult (4.5 months) rat retinas. We have found that in the diabetic retinas there was an up-regulation of senescence-associated markers SA-β-Gal, p16INK4a and miR34a, which correlated with decreased expression of SIRT1, a target of miR34a. Expression of senescence-associated factors primarily found in retinal microvasculature of diabetic rats exceeded levels measured in adult and aging rat retinas. In aging rats, retinal expression of senescence associated-factors was mainly localized at the level of the retinal pigmented epithelium and only minimally in the retinal microvasculature. The expression of oxidative/nitrative stress markers such as 4-hydroxynonenal and nitrotyrosine was more pronounced in the retinal vasculature of diabetic rats as compared to normoglycemic aging and adult rat retinas. Treatments of STZ-rats with the anti-nitrating drug FeTPPS (10mg/Kg/day) significantly reduced the appearance of senescence markers in the retinal microvasculature. Our results demonstrate that hyperglycemia accelerates retinal microvascular cell aging whereas physiological aging affects primarily cells of the retinal pigmented epithelium. In conclusion, hyperglycemia-induced retinal vessel dysfunction and DR progression involve vascular cell senescence due to increased oxidative/nitrative stress.
Collapse
Affiliation(s)
- Folami Lamoke
- Dept. of Ophthalmology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Sean Shaw
- Dept. of Ophthalmology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Jianghe Yuan
- Dept. of Ophthalmology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Sudha Ananth
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Michael Duncan
- Dept. of Medicine, Section of Gastroenterology/Hepatology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Pamela Martin
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
| | - Manuela Bartoli
- Dept. of Ophthalmology, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
27
|
Choudhary P, Dodsworth BT, Sidders B, Gutteridge A, Michaelides C, Duckworth JK, Whiting PJ, Benn CL. A FOXM1 Dependent Mesenchymal-Epithelial Transition in Retinal Pigment Epithelium Cells. PLoS One 2015; 10:e0130379. [PMID: 26121260 PMCID: PMC4488273 DOI: 10.1371/journal.pone.0130379] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 05/20/2015] [Indexed: 12/31/2022] Open
Abstract
The integrity of the epithelium is maintained by a complex but regulated interplay of processes that allow conversion of a proliferative state into a stably differentiated state. In this study, using human embryonic stem cell (hESC) derived Retinal Pigment Epithelium (RPE) cells as a model; we have investigated the molecular mechanisms that affect attainment of the epithelial phenotype. We demonstrate that RPE undergo a Mesenchymal–Epithelial Transition in culture before acquiring an epithelial phenotype in a FOXM1 dependent manner. We show that FOXM1 directly regulates proliferation of RPE through transcriptional control of cell cycle associated genes. Additionally, FOXM1 modulates expression of the signaling ligands BMP7 and Wnt5B which act reciprocally to enable epithelialization. This data uncovers a novel effect of FOXM1 dependent activities in contributing towards epithelial fate acquisition and furthers our understanding of the molecular regulators of a cell type that is currently being evaluated as a cell therapy.
Collapse
Affiliation(s)
- Parul Choudhary
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
- * E-mail: (PC); (CLB)
| | | | - Ben Sidders
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
| | - Alex Gutteridge
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
| | - Christos Michaelides
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
| | - Joshua Kane Duckworth
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
| | - Paul John Whiting
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
| | - Caroline Louise Benn
- Neusentis, Pfizer Ltd, The Portway, Granta Park, Great Abington, Cambridge, United Kingdom
- * E-mail: (PC); (CLB)
| |
Collapse
|
28
|
Boatright JH, Dalal N, Chrenek MA, Gardner C, Ziesel A, Jiang Y, Grossniklaus HE, Nickerson JM. Methodologies for analysis of patterning in the mouse RPE sheet. Mol Vis 2015; 21:40-60. [PMID: 25593512 PMCID: PMC4301600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/12/2015] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Our goal was to optimize procedures for assessing shapes, sizes, and other quantitative metrics of retinal pigment epithelium (RPE) cells and contact- and noncontact-mediated cell-to-cell interactions across a large series of flatmount RPE images. METHODS The two principal methodological advances of this study were optimization of a mouse RPE flatmount preparation and refinement of open-access software to rapidly analyze large numbers of flatmount images. Mouse eyes were harvested, and extra-orbital fat and muscles were removed. Eyes were fixed for 10 min, and dissected by puncturing the cornea with a sharp needle or a stab knife. Four radial cuts were made with iridectomy scissors from the puncture to near the optic nerve head. The lens, iris, and the neural retina were removed, leaving the RPE sheet exposed. The dissection and outcomes were monitored and evaluated by video recording. The RPE sheet was imaged under fluorescence confocal microscopy after staining for ZO-1 to identify RPE cell boundaries. Photoshop, Java, Perl, and Matlab scripts, as well as CellProfiler, were used to quantify selected parameters. Data were exported into Excel spreadsheets for further analysis. RESULTS A simplified dissection procedure afforded a consistent source of images that could be processed by computer. The dissection and flatmounting techniques were illustrated in a video recording. Almost all of the sheet could be routinely imaged, and substantial fractions of the RPE sheet (usually 20-50% of the sheet) could be analyzed. Several common technical problems were noted and workarounds developed. The software-based analysis merged 25 to 36 images into one and adjusted settings to record an image suitable for large-scale identification of cell-to-cell boundaries, and then obtained quantitative descriptors of the shape of each cell, its neighbors, and interactions beyond direct cell-cell contact in the sheet. To validate the software, human- and computer-analyzed results were compared. Whether tallied manually or automatically with software, the resulting cell measurements were in close agreement. We compared normal with diseased RPE cells during aging with quantitative cell size and shape metrics. Subtle differences between the RPE sheet characteristics of young and old mice were identified. The IRBP(-/-) mouse RPE sheet did not differ from C57BL/6J (wild type, WT), suggesting that IRBP does not play a direct role in maintaining the health of the RPE cell, while the slow loss of photoreceptor (PhR) cells previously established in this knockout does support a role in the maintenance of PhR cells. Rd8 mice exhibited several measurable changes in patterns of RPE cells compared to WT, suggesting a slow degeneration of the RPE sheet that had not been previously noticed in rd8. CONCLUSIONS An optimized dissection method and a series of programs were used to establish a rapid and hands-off analysis. The software-aided, high-sampling-size approach performed as well as trained human scorers, but was considerably faster and easier. This method allows tens to hundreds of thousands of cells to be analyzed, each with 23 metrics. With this combination of dissection and image analysis of the RPE sheet, we can now analyze cell-to-cell interactions of immediate neighbors. In the future, we may be able to observe interactions of second, third, or higher ring neighbors and analyze tension in sheets, which might be expected to deviate from normal near large bumps in the RPE sheet caused by druse or when large frank holes in the RPE sheet are observed in geographic atrophy. This method and software can be readily applied to other aspects of vision science, neuroscience, and epithelial biology where patterns may exist in a sheet or surface of cells.
Collapse
Affiliation(s)
| | - Nupur Dalal
- Department of Ophthalmology, Emory University, Atlanta, GA
| | | | | | - Alison Ziesel
- Department of Ophthalmology, Emory University, Atlanta, GA
| | - Yi Jiang
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA
| | | | | |
Collapse
|
29
|
Locational heterogeneity of maturation by changes in migratory behaviors of human retinal pigment epithelial cells in culture. J Biosci Bioeng 2015; 119:107-12. [DOI: 10.1016/j.jbiosc.2014.05.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 05/07/2014] [Accepted: 05/30/2014] [Indexed: 11/19/2022]
|
30
|
Patil H, Saha A, Senda E, Cho KI, Haque M, Yu M, Qiu S, Yoon D, Hao Y, Peachey NS, Ferreira PA. Selective impairment of a subset of Ran-GTP-binding domains of ran-binding protein 2 (Ranbp2) suffices to recapitulate the degeneration of the retinal pigment epithelium (RPE) triggered by Ranbp2 ablation. J Biol Chem 2014; 289:29767-89. [PMID: 25187515 DOI: 10.1074/jbc.m114.586834] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Retinal pigment epithelium (RPE) degeneration underpins diseases triggered by disparate genetic lesions, noxious insults, or both. The pleiotropic Ranbp2 controls the expression of intrinsic and extrinsic pathological stressors impinging on cellular viability. However, the physiological targets and mechanisms controlled by Ranbp2 in tissue homeostasis, such as RPE, are ill defined. We show that mice, RPE-cre::Ranbp2(-/-), with selective Ranbp2 ablation in RPE develop pigmentary changes, syncytia, hypoplasia, age-dependent centrifugal and non-apoptotic degeneration of the RPE, and secondary leakage of choriocapillaris. These manifestations are accompanied by the development of F-actin clouds, metalloproteinase-11 activation, deregulation of expression or subcellular localization of critical RPE proteins, atrophic cell extrusions into the subretinal space, and compensatory proliferation of peripheral RPE. To gain mechanistic insights into what Ranbp2 activities are vital to the RPE, we performed genetic complementation analyses of transgenic lines of bacterial artificial chromosomes of Ranbp2 harboring loss of function of selective Ranbp2 domains expressed in a Ranbp2(-/-) background. Among the transgenic lines produced, only Tg(RBD2/3*-HA)::RPE-cre::Ranbp2(-/-)-expressing mutations, which selectively impair binding of RBD2/3 (Ran-binding domains 2 and 3) of Ranbp2 to Ran-GTP, recapitulate RPE degeneration, as observed with RPE-cre::Ranbp2(-/-). By contrast, Tg(RBD2/3*-HA) expression rescues the degeneration of cone photoreceptors lacking Ranbp2. The RPE of RPE-cre::Ranbp2(-/-) and Tg(RBD2/3*-HA)::RPE-cre::Ranbp2(-/-) share proteostatic deregulation of Ran GTPase, serotransferrin, and γ-tubulin and suppression of light-evoked electrophysiological responses. These studies unravel selective roles of Ranbp2 and its RBD2 and RBD3 in RPE survival and functions. We posit that the control of Ran GTPase by Ranbp2 emerges as a novel therapeutic target in diseases promoting RPE degeneration.
Collapse
Affiliation(s)
| | - Arjun Saha
- From the Departments of Ophthalmology and
| | | | | | | | - Minzhong Yu
- the Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195
| | - Sunny Qiu
- From the Departments of Ophthalmology and
| | - Dosuk Yoon
- From the Departments of Ophthalmology and
| | - Ying Hao
- From the Departments of Ophthalmology and
| | - Neal S Peachey
- the Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, the Research Service, Cleveland Veterans Affairs Medical Center, Cleveland, Ohio 44106, and the Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio 44195
| | - Paulo A Ferreira
- From the Departments of Ophthalmology and Pathology, Duke University Medical Center, Durham, North Carolina 27710,
| |
Collapse
|
31
|
Kuznetsova AV. Morphological and physiological characteristics of the native retinal pigment epithelium in vertebrate animals and human. ACTA ACUST UNITED AC 2014. [DOI: 10.1134/s2079086414020030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
32
|
McHugh KJ, Tao SL, Saint-Geniez M. Porous poly(ε-caprolactone) scaffolds for retinal pigment epithelium transplantation. Invest Ophthalmol Vis Sci 2014; 55:1754-62. [PMID: 24550370 DOI: 10.1167/iovs.13-12833] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Retinal pigment epithelium (RPE) transplantation is a promising strategy for the treatment of dry age-related macular degeneration (AMD). However, previous attempts at subretinal RPE cell transplantation have experienced limited success due to poor adhesion, organization, and function on aged or diseased Bruch's membrane. Instead, cell-based strategies may benefit from a synthetic scaffold that mimics the functions of healthy Bruch's membrane to promote the formation of a functional RPE monolayer while maintaining metabolite exchange between the vasculature and outer retina. METHODS This study evaluated the behavior of human RPE on nanopatterned porous poly(ε-caprolactone) (PCL) film as a potential scaffold for therapeutic transplantation. Fetal human RPE (fhRPE) was cultured on porous PCL, nonporous PCL, or Costar porous polyester transwells for up to 8 weeks and assessed using light microscopy, fluorescent microscopy, transepithelial resistance, quantitative PCR, ELISAs, and phagocytosis assays. RESULTS fhRPE on porous PCL displayed improved markers of maturity and function compared with both porous polyester transwells and nonporous PCL, including pigmentation, increased cell density, superior barrier function, up-regulation of RPE-specific genes, and polarized growth factor secretion. CONCLUSIONS This study indicates that porous PCL is an attractive scaffold for RPE transplantation. In addition to being biocompatible with the subretinal space, porous PCL also allows for trans-scaffold metabolite transport and significantly improves RPE cell behavior compared to nonporous PCL or porous polyester transwells.
Collapse
|
33
|
Machalińska A, Lejkowska R, Duchnik M, Kawa M, Rogińska D, Wiszniewska B, Machaliński B. Dose-dependent retinal changes following sodium iodate administration: application of spectral-domain optical coherence tomography for monitoring of retinal injury and endogenous regeneration. Curr Eye Res 2014; 39:1033-41. [PMID: 24661221 DOI: 10.3109/02713683.2014.892996] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The purpose of this study was to demonstrate the progression of acute retinal injury by correlating histological sections with in vivo spectral-domain optical coherence tomography (SD-OCT) images. METHODS Male C57BL/6 mice were treated intravenously with two different sodium iodate (NaIO3) doses (35 mg/kg or 15 mg/kg). In vivo SD-OCT was performed up to 3 months post-injury. Ex vivo retinal histology, TUNEL and IsolectinB4 immunostaining were also conducted. Quantitative comparison of histopathological images and SD-OCT images was performed. RESULTS SD-OCT examination revealed that administration of 35 mg/kg NaIO3 was associated with progressive and irreversible retinal degeneration. On day 3 post-injury, we found numerous apoptotic cells in the outer nuclear layer (ONL) that strongly corresponded to hyper-reflective areas in the SD-OCT images. At 7 d post-injury, SD-OCT images showed irregular-shaped patterns of hyper-reflectivity in the retinal pigment epithelium (RPE) that corresponded with the accumulation of macrophages phagocytosing melanin granules and cell debris. Additionally, we documented hyper-reflective opacities in the vitreous that were most numerous at 7 d. At 3 months post-injury, the neurosensory retina was significantly thinner, predominantly due to progressive photoreceptor (PR) loss. In contrast, administration of 15 mg/kg NaIO3 did not induce hyper-reflectivity of ONL in SD-OCT images, which indicates a lack of massive PR cell death. At 3 months post-injury, SD-OCT images showed the complete restoration of outer retina lamination and restoration of hyper-reflective structural bands. Histological assessment of retinas acquired after the last SD-OCT imaging session revealed complete regeneration of the RPE and considerable improvement of PR architecture. CONCLUSIONS Our findings showed the high level of effectiveness of SD-OCT imaging for monitoring dynamic changes in retinal morphology following acute retinal injury. Moreover, we demonstrated for the first time that SD-OCT can be used to non-invasively detect regeneration in the damaged retina.
Collapse
|
34
|
Ozgen H, Kahya N, de Jonge JC, Smith GS, Harauz G, Hoekstra D, Baron W. Regulation of cell proliferation by nucleocytoplasmic dynamics of postnatal and embryonic exon-II-containing MBP isoforms. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:517-30. [DOI: 10.1016/j.bbamcr.2013.11.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/26/2013] [Accepted: 11/29/2013] [Indexed: 12/15/2022]
|
35
|
Liegl R, Koenig S, Siedlecki J, Haritoglou C, Kampik A, Kernt M. Temsirolimus inhibits proliferation and migration in retinal pigment epithelial and endothelial cells via mTOR inhibition and decreases VEGF and PDGF expression. PLoS One 2014; 9:e88203. [PMID: 24586308 PMCID: PMC3935828 DOI: 10.1371/journal.pone.0088203] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 01/10/2014] [Indexed: 12/22/2022] Open
Abstract
Due to their high prevalence, retinal vascular diseases including age related macular degeneration (AMD), retinal vein occlusions (RVO), diabetic retinopathy (DR) and diabetic macular edema have been major therapeutic targets over the last years. The pathogenesis of these diseases is complex and yet not fully understood. However, increased proliferation, migration and angiogenesis are characteristic cellular features in almost every retinal vascular disease. The introduction of vascular endothelial growth factor (VEGF) binding intravitreal treatment strategies has led to great advances in the therapy of these diseases. While the predominant part of affected patients benefits from the specific binding of VEGF by administering an anti-VEGF antibody into the vitreous cavity, a small number of non-responders exist and alternative or additional therapeutic strategies should therefore be evaluated. The mammalian target of rapamycin (mTOR) is a central signaling pathway that eventually triggers up-regulation of cellular proliferation, migration and survival and has been identified to play a key role in angiogenesis. In the present study we were able to show that both retinal pigment epithelial (RPE) cells as wells as human umbilical vein endothelial cells (HUVEC) are inhibited in proliferating and migrating after treatment with temsirolimus in non-toxic concentrations. Previous studies suggest that the production of VEGF, platelet derived growth factor (PDGF) and other important cytokines is not only triggered by hypoxia but also by mTOR itself. Our results indicate that temsirolimus decreases VEGF and PDGF expression on RNA and protein levels significantly. We therefore believe that the mTOR inhibitor temsirolimus might be a promising drug in the future and it seems worthwhile to evaluate complementary therapeutic effects with anti-VEGF drugs for patients not profiting from mono anti-VEGF therapy alone.
Collapse
Affiliation(s)
- Raffael Liegl
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Susanna Koenig
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Jakob Siedlecki
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | | | - Anselm Kampik
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Marcus Kernt
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| |
Collapse
|
36
|
Fuhrmann S, Zou C, Levine EM. Retinal pigment epithelium development, plasticity, and tissue homeostasis. Exp Eye Res 2013; 123:141-50. [PMID: 24060344 DOI: 10.1016/j.exer.2013.09.003] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/05/2013] [Accepted: 09/07/2013] [Indexed: 12/13/2022]
Abstract
The retinal pigment epithelium (RPE) is a simple epithelium interposed between the neural retina and the choroid. Although only 1 cell-layer in thickness, the RPE is a virtual workhorse, acting in several capacities that are essential for visual function and preserving the structural and physiological integrities of neighboring tissues. Defects in RPE function, whether through chronic dysfunction or age-related decline, are associated with retinal degenerative diseases including age-related macular degeneration. As such, investigations are focused on developing techniques to replace RPE through stem cell-based methods, motivated primarily because of the seemingly limited regeneration or self-repair properties of mature RPE. Despite this, RPE cells have an unusual capacity to transdifferentiate into various cell types, with the particular fate choices being highly context-dependent. In this review, we describe recent findings elucidating the mechanisms and steps of RPE development and propose a developmental framework for understanding the apparent contradiction in the capacity for low self-repair versus high transdifferentiation.
Collapse
Affiliation(s)
- Sabine Fuhrmann
- Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA.
| | - ChangJiang Zou
- Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA.
| | - Edward M Levine
- Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA.
| |
Collapse
|
37
|
Swoboda JG, Elliott J, Deshmukh V, de Lichtervelde L, Shen W, Tremblay MS, Peters EC, Cho CY, Lu B, Girman S, Wang S, Schultz PG. Small molecule mediated proliferation of primary retinal pigment epithelial cells. ACS Chem Biol 2013; 8:1407-11. [PMID: 23621521 DOI: 10.1021/cb4001712] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Retinal pigment epithelial (RPE) cells form a monolayer adjacent to the retina and play a critical role in the visual light cycle. Degeneration of RPE cells results in retinal disorders such as age-related macular degeneration. Cell transplant strategies have potential therapeutic value for such disorders; however, risks associated with an inadequate supply of donor cells limit their therapeutic success. The identification of factors that proliferate RPE cells ex vivo could provide a renewable source of cells for transplantation. Here, we report that a small molecule (WS3) can reversibly proliferate primary RPE cells isolated from fetal and adult human donors. Following withdrawal of WS3, RPE cells differentiate into a functional monolayer, as exhibited by their expression of mature RPE genes and phagocytosis of photoreceptor outer segments. Furthermore, chemically expanded RPE cells preserve vision when transplanted into dystrophic Royal College of Surgeons (RCS) rats, a well-established model of retinal degeneration.
Collapse
Affiliation(s)
- Jonathan G. Swoboda
- Department of Chemistry and
the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La
Jolla, California 92037, United States
| | - Jimmy Elliott
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay
Hopkins Drive, San Diego, California 92121, United States
| | - Vishal Deshmukh
- Department of Chemistry and
the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La
Jolla, California 92037, United States
| | - Lorenzo de Lichtervelde
- Department of Chemistry and
the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La
Jolla, California 92037, United States
| | - Weijun Shen
- California Institute for Biomedical Research, 11119 North Torrey Pines Road,
La Jolla, California 92037, United States
| | - Matthew S. Tremblay
- California Institute for Biomedical Research, 11119 North Torrey Pines Road,
La Jolla, California 92037, United States
| | - Eric C. Peters
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay
Hopkins Drive, San Diego, California 92121, United States
| | - Charles Y. Cho
- Genomics Institute of the Novartis Research Foundation, 10675 John Jay
Hopkins Drive, San Diego, California 92121, United States
| | - Bin Lu
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard,
Los Angeles, California 90048, United States
| | - Sergej Girman
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard,
Los Angeles, California 90048, United States
| | - Shaomei Wang
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Boulevard,
Los Angeles, California 90048, United States
| | - Peter G. Schultz
- Department of Chemistry and
the Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La
Jolla, California 92037, United States
| |
Collapse
|
38
|
Machalińska A, Kawa MP, Pius-Sadowska E, Rogińska D, Kłos P, Baumert B, Wiszniewska B, Machaliński B. Endogenous regeneration of damaged retinal pigment epithelium following low dose sodium iodate administration: An insight into the role of glial cells in retinal repair. Exp Eye Res 2013; 112:68-78. [DOI: 10.1016/j.exer.2013.04.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 03/19/2013] [Accepted: 04/08/2013] [Indexed: 12/19/2022]
|
39
|
Autophagy regulating kinases as potential therapeutic targets for age-related macular degeneration. Future Med Chem 2013. [PMID: 23190104 DOI: 10.4155/fmc.12.169] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of central vision loss in the elderly in the developed countries. The number of AMD patients will double during the next decades due to increasing number of aged people. Chronic oxidative stress, inflammation and accumulation of protein-rich deposits both in the retinal pigment epithelium lysosomes and under the retinal pigment epithelium herald the onset of AMD. The disease can be divided into dry and wet AMD forms. The dry form of the disease is more prevalent accounting for up to 90% of all cases. Continued intraocular injections are the current treatment strategy to prevent progression of wet AMD. It is a major challenge to develop new drugs that could prevent or at least ease the symptoms of the increasing population of AMD patients. Since AMD pathology is clearly associated with accumulated protein deposits, the autophagy clearance system might represent a potential future therapeutic target for AMD as is thoroughly discussed here.
Collapse
|
40
|
Kokkinopoulos I. 670 nm LED ameliorates inflammation in the CFH(-/-) mouse neural retina. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2013; 122:24-31. [PMID: 23584451 DOI: 10.1016/j.jphotobiol.2013.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 03/12/2013] [Accepted: 03/17/2013] [Indexed: 12/27/2022]
Abstract
Para-inflammation in the neural retina is thought to contribute to the onset of some age-related retinal diseases. Continuous innate immune system activation, manifests in progressive chronic inflammation, macrophage invasion and cell loss, resulting in visual loss. We have previously shown that mitochondrial function is augmented following 670 nm LED exposure, leading to reduced retinal inflammation. Here, it was asked whether 670 nm LED regulates para-inflammation in an aged-related macular degeneration mouse model. Mutant CFH(-/-) mice were exposed to four 90 s exposures over 2 days for 1 week and 8 weeks. These regimes significantly reduced activated macrophage number, TNF-alpha and MIF protein expression levels. Immuno-reactivity to C3, C3b and calcitonin, all markers of inflammatory status were also altered. Finally, innate immune proteins, TLR 2 and 4, showed a marked decrease in protein expression. These findings support the notion that 670 nm LED regulates innate immunity, alleviating inflammation in the neural retina of an age-related macular degeneration mouse model.
Collapse
Affiliation(s)
- Ioannis Kokkinopoulos
- School of Biomedical and Health Sciences, Wolfson Centre for Age-Related Diseases, King's College London, UK.
| |
Collapse
|
41
|
Palma-Nicolás JP, López-Colomé AM. Thrombin induces slug-mediated E-cadherin transcriptional repression and the parallel up-regulation of N-cadherin by a transcription-independent mechanism in RPE cells. J Cell Physiol 2013; 228:581-9. [PMID: 22833386 DOI: 10.1002/jcp.24165] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 07/17/2012] [Indexed: 12/14/2022]
Abstract
The proliferation, directional migration to the vitreous and epithelial-mesenchymal transition (EMT) of quiescent, differentiated retinal pigment epithelium (RPE) cells is a major feature in the development of proliferative vitreoretinopathy (PVR) following exposure of the immuno-privileged eye niche to serum components, thrombin among them. We have previously documented thrombin induction of RPE cell proliferation and migration. We here analyzed the effect of thrombin on the E/N cadherin switch, a hallmark of EMT. Results show that thrombin induces the specific repression of epithelial E-cadherin gene transcription, alongside with the up-regulation of mesenchymal N-cadherin protein in RPE cells. We demonstrate, for the first time, that thrombin induces E-cadherin repression by stimulating snail-2 (SLUG) transcription factor expression, and the concomitant up-regulation of N-cadherin through the transcription-independent increase in protein translation promoted by PI3K/PKC-ζ/mTOR signaling. Our present findings suggest that the activation of protease-activated receptor-1 (PAR-1) by thrombin induces EMT of RPE cells, further supporting a central role for thrombin in PVR pathogenesis.
Collapse
Affiliation(s)
- José Prisco Palma-Nicolás
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico, DF, Mexico
| | | |
Collapse
|
42
|
Kokkinopoulos I, Colman A, Hogg C, Heckenlively J, Jeffery G. Age-related retinal inflammation is reduced by 670 nm light via increased mitochondrial membrane potential. Neurobiol Aging 2013; 34:602-9. [DOI: 10.1016/j.neurobiolaging.2012.04.014] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 04/09/2012] [Accepted: 04/28/2012] [Indexed: 12/13/2022]
|
43
|
Forrester JV. Bowman lecture on the role of inflammation in degenerative disease of the eye. Eye (Lond) 2013; 27:340-52. [PMID: 23288138 DOI: 10.1038/eye.2012.265] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Inflammation, in the pathogenesis of many diseases previously thought to be strictly genetic, degenerative, metabolic, or endocrinologic in aetiology, has gradually entered the framework of a general mechanism of disease. This is exemplified by conditions such as Parkinson's disease, Alzheimer's disease, atherosclerosis, diabetes, and the more recently described Metabolic Syndrome. Chronic inflammatory processes have a significant, if not primary role, in ophthalmic diseases, particularly in retinal degenerative diseases. However, inflammation itself is not easy to define, and some aspects of inflammation may be beneficial, in a process described as 'para-inflammation' by Medhzitov. In contrast, the damaging effects of inflammation, mediated by pro-inflammatory macrophages through activation of the intracellular protein-signalling complexes, termed inflammasomes, are well recognised and are important therapeutic targets. In this review, the range of inflammatory processes in the eye is evaluated in the context of how these processes impact upon retinal degenerative disease, particularly diabetic retinopathy and age-related macular degeneration.
Collapse
Affiliation(s)
- J V Forrester
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, UK.
| |
Collapse
|
44
|
Kasaoka M, Ma J, Lashkari K. c-Met modulates RPE migratory response to laser-induced retinal injury. PLoS One 2012; 7:e40771. [PMID: 22808260 PMCID: PMC3396594 DOI: 10.1371/journal.pone.0040771] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 06/13/2012] [Indexed: 12/28/2022] Open
Abstract
Retinal laser injuries are often associated with aberrant migration of the retinal pigment epithelium (RPE), which can cause expansion of the scar beyond the confines of the original laser burn. In this study, we devised a novel method of laser-induced injury to the RPE layer in mouse models and began to dissect the mechanisms associated with pathogenesis and progression of laser-induced RPE injury. We have hypothesized that the proto-oncogene receptor, c-Met, is intimately involved with migration of RPE cells, and may be an early responder to injury. Using transgenic mouse models, we show that constitutive activation of c-Met induces more robust RPE migration into the outer retina of laser-injured eyes, while abrogation of the receptor using a cre-lox method reduces these responses. We also demonstrate that retinal laser injury increases expression of both HGF and c-Met, and activation of c-Met after injury is correlated with RPE cell migration. RPE migration may be responsible for clinically significant anatomic changes observed after laser injury. Abrogation of c-Met activity may be a therapeutic target to minimize retinal damage from aberrant RPE cell migration.
Collapse
Affiliation(s)
- Masataka Kasaoka
- Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Ophthalmology, Kurume University School of Medicine, Kurume, Japan
| | - Jie Ma
- Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kameran Lashkari
- Schepens Eye Research Institute, Massachusetts Eye & Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
45
|
Novel method for the rapid isolation of RPE cells specifically for RNA extraction and analysis. Exp Eye Res 2012; 102:1-9. [PMID: 22721721 DOI: 10.1016/j.exer.2012.06.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 05/22/2012] [Accepted: 06/08/2012] [Indexed: 01/12/2023]
Abstract
RPE cells are involved in the pathogenesis of many retinal diseases. Accurate analysis of RPE gene expression profiles in different scenarios will increase our understanding of disease mechanisms. Our objective in this study was to develop an improved method for the isolation of RPE cells, specifically for RNA analysis. Mouse RPE cells were isolated using different techniques, including mechanical dissociation techniques and a new technique we refer to here as "Simultaneous RPE cell Isolation and RNA Stabilization" (SRIRS method). RNA was extracted from the RPE cells. An RNA bioanalyzer was used to determine the quantity and quality of RNA. qPCR was used to determine contamination with non-RPE-derived RNA. Several parameters with a potential impact on the isolation protocol were studied and optimized. A marked improvement in the quantity and quality of RPE-derived RNA was obtained with the SRIRS technique. We could get the RPE in direct contact with the RNA protecting agent within 1 min of enucleation, and the RPE isolated within 11 min of enucleation. There was no significant contamination with vascular, choroidal or scleral-derived RNA. We have developed a fast, easy and reliable method for the isolation of RPE cells that leads to a high yield of RPE-derived RNA while preserving its quality. We believe this technique will be useful for future studies looking at gene expression profiles of RPE cells and their role in the pathophysiology of retinal diseases.
Collapse
|
46
|
Ring H, Mendu SK, Shirazi-Fard S, Birnir B, Hallböök F. GABA maintains the proliferation of progenitors in the developing chick ciliary marginal zone and non-pigmented ciliary epithelium. PLoS One 2012; 7:e36874. [PMID: 22590629 PMCID: PMC3348890 DOI: 10.1371/journal.pone.0036874] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/12/2012] [Indexed: 01/02/2023] Open
Abstract
GABA is more than the main inhibitory neurotransmitter found in the adult CNS. Several studies have shown that GABA regulates the proliferation of progenitor and stem cells. This work examined the effects of the GABA(A) receptor system on the proliferation of retinal progenitors and non-pigmented ciliary epithelial (NPE) cells. qRT-PCR and whole-cell patch-clamp electrophysiology were used to characterize the GABA(A) receptor system. To quantify the effects on proliferation by GABA(A) receptor agonists and antagonists, incorporation of thymidine analogues was used. The results showed that the NPE cells express functional extrasynaptic GABA(A) receptors with tonic properties and that low concentration of GABA is required for a baseline level of proliferation. Antagonists of the GABA(A) receptors decreased the proliferation of dissociated E12 NPE cells. Bicuculline also had effects on progenitor cell proliferation in intact E8 and E12 developing retina. The NPE cells had low levels of the Cl-transporter KCC2 compared to the mature retina, suggesting a depolarising role for the GABA(A) receptors. Treatment with KCl, which is known to depolarise membranes, prevented some of the decreased proliferation caused by inhibition of the GABA(A) receptors. This supported the depolarising role for the GABA(A) receptors. Inhibition of L-type voltage-gated Ca(2+) channels (VGCCs) reduced the proliferation in the same way as inhibition of the GABA(A) receptors. Inhibition of the channels increased the expression of the cyclin-dependent kinase inhibitor p27(KIP1), along with the reduced proliferation. These results are consistent with that when the membrane potential indirectly regulates cell proliferation with hyperpolarisation of the membrane potential resulting in decreased cell division. The increased expression of p27(KIP1) after inhibition of either the GABA(A) receptors or the L-type VGCCs suggests a link between the GABA(A) receptors, membrane potential, and intracellular Ca(2+) in regulating the cell cycle.
Collapse
Affiliation(s)
- Henrik Ring
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | | | | | - Bryndis Birnir
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Finn Hallböök
- Department of Neuroscience, Uppsala University, Uppsala, Sweden
| |
Collapse
|
47
|
Hyttinen JMT, Petrovski G, Salminen A, Kaarniranta K. 5'-Adenosine monophosphate-activated protein kinase--mammalian target of rapamycin axis as therapeutic target for age-related macular degeneration. Rejuvenation Res 2011; 14:651-60. [PMID: 22007913 DOI: 10.1089/rej.2011.1220] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Age-related macular degeneration (AMD) is the most common reason for blindness in developed countries. AMD essentially involves chronic oxidative stress, increased accumulation of lipofuscin in retinal pigment epithelial (RPE) cells, and extracellular drusen formation, as well as presence of chronic inflammation in the retina. The capacity to prevent the accumulation of cellular cytotoxic protein aggregates is decreased in senescent cells, which may evoke lipofuscin accumulation into lysosomes in postmitotic RPE cells. The formation of lipofuscin, in turn, decreases the lysosomal enzyme activity and impairs the autophagic clearance of damaged proteins destined for cellular removal. 5'-Adenosine monophosphate-activated protein kinase (AMPK) is a well-known inhibitor of mammalian target of rapamycin (mTOR) that subsequently evokes induction of autophagy. This review examines the novel potential therapeutic targets on the AMPK-mTOR axis and the ways in which autophagy clearance can suppress or prevent RPE degeneration and development of AMD.
Collapse
Affiliation(s)
- Juha M T Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O.Box 1627, FI-70211 Kuopio, Finland.
| | | | | | | |
Collapse
|