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Bourauel L, Vaisband M, von der Emde L, Bermond K, Tarau IS, Heintzmann R, Holz FG, Curcio CA, Hasenauer J, Ach T. Spectral Analysis of Human Retinal Pigment Epithelium Cells in Healthy and AMD Eyes. Invest Ophthalmol Vis Sci 2024; 65:10. [PMID: 38170540 PMCID: PMC10768704 DOI: 10.1167/iovs.65.1.10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 12/08/2023] [Indexed: 01/05/2024] Open
Abstract
Purpose Retinal pigment epithelium (RPE) cells show strong autofluorescence (AF). Here, we characterize the AF spectra of individual RPE cells in healthy eyes and those affected by age-related macular degeneration (AMD) and investigate associations between AF spectral response and the number of intracellular AF granules per cell. Methods RPE-Bruch's membrane flatmounts of 22 human donor eyes, including seven AMD-affected eyes (early AMD, three; geographic atrophy, one; neovascular, three) and 15 unaffected macula (<51 years, eight; >80 years, seven), were imaged at the fovea, perifovea, and near-periphery using confocal AF microscopy (excitation 488 nm), and emission spectra were recorded (500-710 nm). RPE cells were manually segmented with computer assistance and stratified by disease status, and emission spectra were analyzed using cubic spline transforms. Intracellular granules were manually counted and classified. Linear mixed models were used to investigate associations between spectra and the number of intracellular granules. Results Spectra of 5549 RPE cells were recorded. The spectra of RPE cells in healthy eyes showed similar emission curves that peaked at 580 nm for fovea and perifovea and at 575 and 580 nm for near-periphery. RPE spectral curves in AMD eyes differed significantly, being blue shifted by 10 nm toward shorter wavelengths. No significant association coefficients were found between wavelengths and granule counts. Conclusions This large series of RPE cell emission spectra at precisely predefined retinal locations showed a hypsochromic spectral shift in AMD. Combining different microscopy techniques, our work has identified cellular RPE spectral AF and subcellular granule properties that will inform future in vivo investigations using single-cell imaging.
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Affiliation(s)
- Leonie Bourauel
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Marc Vaisband
- Institute of Life & Medical Sciences, University of Bonn, Bonn, Germany
- Department of Internal Medicine III with Haematology, Medical Oncology, Haemostaseology, Infectiology and Rheumatology, Oncologic Center, Salzburg Cancer Research Institute Laboratory for Immunological and Molecular Cancer Research, Paracelsus Medical University, Salzburg, Austria
- Cancer Cluster Salzburg, Salzburg, Austria
| | | | - Katharina Bermond
- Department of Ophthalmology, Ludwigshafen Hospital, Ludwigshafen, Germany
| | - Ioana Sandra Tarau
- Department of Ophthalmology, Asklepios Klinik Nord - Heidberg, Hamburg, Germany
| | - Rainer Heintzmann
- Leibniz Institute of Photonic Technology, Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Jena, Germany
| | - Frank G. Holz
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Christine A. Curcio
- Department of Ophthalmology, University of Alabama at Birmingham, Alabama, Alabama, United States
| | - Jan Hasenauer
- Institute of Life & Medical Sciences, University of Bonn, Bonn, Germany
| | - Thomas Ach
- Department of Ophthalmology, University of Bonn, Bonn, Germany
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2
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Zhang SM, Fan B, Li YL, Zuo ZY, Li GY. Oxidative Stress-Involved Mitophagy of Retinal Pigment Epithelium and Retinal Degenerative Diseases. Cell Mol Neurobiol 2023; 43:3265-3276. [PMID: 37391574 PMCID: PMC10477140 DOI: 10.1007/s10571-023-01383-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/22/2023] [Indexed: 07/02/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized and polarized epithelial cell layer that plays an important role in sustaining the structural and functional integrity of photoreceptors. However, the death of RPE is a common pathological feature in various retinal diseases, especially in age-related macular degeneration (AMD) and diabetic retinopathy (DR). Mitophagy, as a programmed self-degradation of dysfunctional mitochondria, is crucial for maintaining cellular homeostasis and cell survival under stress. RPE contains a high density of mitochondria necessary for it to meet energy demands, so severe stimuli can cause mitochondrial dysfunction and the excess generation of intracellular reactive oxygen species (ROS), which can further trigger oxidative stress-involved mitophagy. In this review, we summarize the classical pathways of oxidative stress-involved mitophagy in RPE and investigate its role in the progression of retinal diseases, aiming to provide a new therapeutic strategy for treating retinal degenerative diseases. The role of mitophagy in AMD and DR. In AMD, excessive ROS production promotes mitophagy in the RPE by activating the Nrf2/p62 pathway, while in DR, ROS may suppress mitophagy by the FOXO3-PINK1/parkin signaling pathway or the TXNIP-mitochondria-lysosome-mediated mitophagy.
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Affiliation(s)
- Si-Ming Zhang
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Bin Fan
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Yu- Lin Li
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Zhao-Yang Zuo
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Guang-Yu Li
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China.
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3
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Cohen-Gulkar M, David A, Messika-Gold N, Eshel M, Ovadia S, Zuk-Bar N, Idelson M, Cohen-Tayar Y, Reubinoff B, Ziv T, Shamay M, Elkon R, Ashery-Padan R. The LHX2-OTX2 transcriptional regulatory module controls retinal pigmented epithelium differentiation and underlies genetic risk for age-related macular degeneration. PLoS Biol 2023; 21:e3001924. [PMID: 36649236 PMCID: PMC9844853 DOI: 10.1371/journal.pbio.3001924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 11/16/2022] [Indexed: 01/18/2023] Open
Abstract
Tissue-specific transcription factors (TFs) control the transcriptome through an association with noncoding regulatory regions (cistromes). Identifying the combination of TFs that dictate specific cell fate, their specific cistromes and examining their involvement in complex human traits remain a major challenge. Here, we focus on the retinal pigmented epithelium (RPE), an essential lineage for retinal development and function and the primary tissue affected in age-related macular degeneration (AMD), a leading cause of blindness. By combining mechanistic findings in stem-cell-derived human RPE, in vivo functional studies in mice and global transcriptomic and proteomic analyses, we revealed that the key developmental TFs LHX2 and OTX2 function together in transcriptional module containing LDB1 and SWI/SNF (BAF) to regulate the RPE transcriptome. Importantly, the intersection between the identified LHX2-OTX2 cistrome with published expression quantitative trait loci, ATAC-seq data from human RPE, and AMD genome-wide association study (GWAS) data, followed by functional validation using a reporter assay, revealed a causal genetic variant that affects AMD risk by altering TRPM1 expression in the RPE through modulation of LHX2 transcriptional activity on its promoter. Taken together, the reported cistrome of LHX2 and OTX2, the identified downstream genes and interacting co-factors reveal the RPE transcription module and uncover a causal regulatory risk single-nucleotide polymorphism (SNP) in the multifactorial common blinding disease AMD.
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Affiliation(s)
- Mazal Cohen-Gulkar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Ahuvit David
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Naama Messika-Gold
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Mai Eshel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Shai Ovadia
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Nitay Zuk-Bar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Maria Idelson
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy and Department of Gynecology, Jerusalem, Israel
| | - Yamit Cohen-Tayar
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
| | - Benjamin Reubinoff
- The Hadassah Human Embryonic Stem Cell Research Center, The Goldyne Savad Institute of Gene Therapy and Department of Gynecology, Jerusalem, Israel
| | - Tamar Ziv
- Smoler Proteomics Center, Lorry I. Lokey Interdisciplinary Center for Life Sciences and Engineering, Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Meir Shamay
- Daniella Lee Casper Laboratory in Viral Oncology, Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (RE); (RAP)
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine and Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel
- * E-mail: (RE); (RAP)
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4
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Wong JHC, Ma JYW, Jobling AI, Brandli A, Greferath U, Fletcher EL, Vessey KA. Exploring the pathogenesis of age-related macular degeneration: A review of the interplay between retinal pigment epithelium dysfunction and the innate immune system. Front Neurosci 2022; 16:1009599. [PMID: 36408381 PMCID: PMC9670140 DOI: 10.3389/fnins.2022.1009599] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/12/2022] [Indexed: 07/30/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in the older population. Classical hallmarks of early and intermediate AMD are accumulation of drusen, a waste deposit formed under the retina, and pigmentary abnormalities in the retinal pigment epithelium (RPE). When the disease progresses into late AMD, vision is affected due to death of the RPE and the light-sensitive photoreceptors. The RPE is essential to the health of the retina as it forms the outer blood retinal barrier, which establishes ocular immune regulation, and provides support for the photoreceptors. Due to its unique anatomical position, the RPE can communicate with the retinal environment and the systemic immune environment. In AMD, RPE dysfunction and the accumulation of drusen drive the infiltration of retinal and systemic innate immune cells into the outer retina. While recruited endogenous or systemic mononuclear phagocytes (MPs) contribute to the removal of noxious debris, the accumulation of MPs can also result in chronic inflammation and contribute to AMD progression. In addition, direct communication and indirect molecular signaling between MPs and the RPE may promote RPE cell death, choroidal neovascularization and fibrotic scarring that occur in late AMD. In this review, we explore how the RPE and innate immune cells maintain retinal homeostasis, and detail how RPE dysfunction and aberrant immune cell recruitment contribute to AMD pathogenesis. Evidence from AMD patients will be discussed in conjunction with data from preclinical models, to shed light on future therapeutic targets for the treatment of AMD.
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5
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Chen X, Wang Y, Wang JN, Cao QC, Sun RX, Zhu HJ, Zhang YR, Ji JD, Liu QH. m6A modification of circSPECC1 suppresses RPE oxidative damage and maintains retinal homeostasis. Cell Rep 2022; 41:111671. [DOI: 10.1016/j.celrep.2022.111671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 07/11/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
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Liang Y, Tan F, Sun X, Cui Z, Gu J, Mao S, Chan HF, Tang S, Chen J. Aberrant Retinal Pigment Epithelial Cells Derived from Induced Pluripotent Stem Cells of a Retinitis Pigmentosa Patient with the PRPF6 Mutation. Int J Mol Sci 2022; 23:ijms23169049. [PMID: 36012314 PMCID: PMC9409096 DOI: 10.3390/ijms23169049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/08/2022] [Accepted: 08/11/2022] [Indexed: 11/16/2022] Open
Abstract
Pre-mRNA processing factors (PRPFs) are vital components of the spliceosome and are involved in the physiological process necessary for pre-mRNA splicing to mature mRNA. As an important member, PRPF6 mutation resulting in autosomal dominant retinitis pigmentosa (adRP) is not common. Recently, we reported the establishment of an induced pluripotent stem cells (iPSCs; CSUASOi004-A) model by reprogramming the peripheral blood mononuclear cells of a PRPF6-related adRP patient, which could recapitulate a consistent disease-specific genotype. In this study, a disease model of retinal pigment epithelial (RPE) cells was generated from the iPSCs of this patient to further investigate the underlying molecular and pathological mechanisms. The results showed the irregular morphology, disorganized apical microvilli and reduced expressions of RPE-specific genes in the patient’s iPSC-derived RPE cells. In addition, RPE cells carrying the PRPF6 mutation displayed a decrease in the phagocytosis of fluorescein isothiocyanate-labeled photoreceptor outer segments and exhibited impaired cell polarity and barrier function. This study will benefit the understanding of PRPF6-related RPE cells and future cell therapy.
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Affiliation(s)
- Yuqin Liang
- Aier School of Ophthalmology, Central South University, Changsha 410015, China
- Aier Eye Institute, Changsha 410015, China
| | - Feng Tan
- Aier School of Ophthalmology, Central South University, Changsha 410015, China
- Aier Eye Institute, Changsha 410015, China
| | - Xihao Sun
- Aier School of Ophthalmology, Central South University, Changsha 410015, China
- Aier Eye Institute, Changsha 410015, China
| | - Zekai Cui
- Aier School of Ophthalmology, Central South University, Changsha 410015, China
- Aier Eye Institute, Changsha 410015, China
| | - Jianing Gu
- Aier Eye Institute, Changsha 410015, China
| | | | - Hon Fai Chan
- Institute for Tissue Engineering and Regenerative Medicine, The Chinese University of Hong Kong, Hong Kong 999077, China
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong 999077, China
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Changsha 410015, China
- Aier Eye Institute, Changsha 410015, China
- Correspondence: (S.T.); (J.C.); Tel.: +86-139-2510-0123 (S.T.); +86-186-7583-9029 (J.C.)
| | - Jiansu Chen
- Aier School of Ophthalmology, Central South University, Changsha 410015, China
- Aier Eye Institute, Changsha 410015, China
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou 510632, China
- Correspondence: (S.T.); (J.C.); Tel.: +86-139-2510-0123 (S.T.); +86-186-7583-9029 (J.C.)
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7
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Hall JC, Paull D, Pébay A, Lidgerwood GE. Human pluripotent stem cells for the modelling of retinal pigment epithelium homeostasis and disease: A review. Clin Exp Ophthalmol 2022; 50:667-677. [PMID: 35739648 PMCID: PMC9546239 DOI: 10.1111/ceo.14128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/06/2022] [Accepted: 06/19/2022] [Indexed: 12/05/2022]
Abstract
Human pluripotent stem cells (hPSCs), which include induced pluripotent stem cells and embryonic stem cells, are powerful tools for studying human development, physiology and disease, including those affecting the retina. Cells from selected individuals, or specific genetic backgrounds, can be differentiated into distinct cell types allowing the modelling of diseases in a dish for therapeutic development. hPSC‐derived retinal cultures have already been used to successfully model retinal pigment epithelium (RPE) degeneration for various retinal diseases including monogenic conditions and complex disease such as age‐related macular degeneration. Here, we will review the current knowledge gained in understanding the molecular events involved in retinal disease using hPSC‐derived retinal models, in particular RPE models. We will provide examples of various conditions to illustrate the scope of applications associated with the use of hPSC‐derived RPE models.
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Affiliation(s)
- Jenna C Hall
- Department of Anatomy and Physiology The University of Melbourne Parkville Victoria Australia
| | - Daniel Paull
- The New York Stem Cell Foundation Research Institute New York New York USA
| | - Alice Pébay
- Department of Anatomy and Physiology The University of Melbourne Parkville Victoria Australia
- Department of Surgery, Royal Melbourne Hospital The University of Melbourne Parkville Victoria Australia
| | - Grace E. Lidgerwood
- Department of Anatomy and Physiology The University of Melbourne Parkville Victoria Australia
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8
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Bindewald-Wittich A, Holz FG, Ach T, Fiorentzis M, Bechrakis NE, Willerding GD. Fundus Autofluorescence Imaging in Patients with Choroidal Melanoma. Cancers (Basel) 2022; 14:cancers14071809. [PMID: 35406581 PMCID: PMC8997882 DOI: 10.3390/cancers14071809] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 12/15/2022] Open
Abstract
Simple Summary The ocular fundus contains molecules that emit fluorescence when excited with light of an appropriate wavelength. Fundus autofluorescence imaging is based on the in vivo detection of intrinsic fluorescence and results in topographic autofluorescence mapping of the ocular fundus. In contrast to fluorescence angiography, where the fluorescing agents need to be administered intravenously, autofluorescence imaging is a non-invasive technique. Even though choroidal melanomas do not contain significant autofluorescent molecules themselves, they may lead to secondary alterations in neighbouring tissues with an impact on the autofluorescence signal recording. Fundus autofluorescence imaging in the context of choroidal melanoma is helpful for differential diagnosis and for monitoring variations over time in affected patients before and after treatment. Abstract Choroidal melanocytic lesions require reliable and precise clinical examination and diagnosis to differentiate benign choroidal nevi from choroidal melanoma, as the latter may become life-threatening through metastatic disease. To come to an accurate diagnosis, as well as for monitoring, and to assess the efficacy of therapy, various imaging modalities may be used, one of which is non-invasive fundus autofluorescence (FAF) imaging using novel high-resolution digital imaging technology. FAF imaging is based on the visualization of intrinsic fluorophores in the ocular fundus. Lipofuscin and melanolipofuscin within the postmitotic retinal pigment epithelium (RPE) cells represent the major fluorophores that contribute to the FAF signal. In addition, the presence or loss of absorbing molecular constituents may have an impact on the FAF signal. A choroidal melanoma can cause secondary retinal and RPE alterations that affect the FAF signal (e.g., occurrence of orange pigment). Therefore, FAF imaging supports multimodal imaging and gives additional information over and above conventional imaging modalities regarding retinal metabolism and RPE health status. This article summarises the features of FAF imaging and the role of FAF imaging in the context of choroidal melanoma, both before and following therapeutic intervention.
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Affiliation(s)
- Almut Bindewald-Wittich
- Augenkompetenz Zentren Heidenheim, 89518 Heidenheim, Germany
- Augenkompetenz Zentren Bopfingen, 73441 Bopfingen, Germany
- Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany; (F.G.H.); (T.A.)
- Correspondence:
| | - Frank G. Holz
- Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany; (F.G.H.); (T.A.)
| | - Thomas Ach
- Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany; (F.G.H.); (T.A.)
| | - Miltiadis Fiorentzis
- Department of Ophthalmology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (M.F.); (N.E.B.)
| | - Nikolaos E. Bechrakis
- Department of Ophthalmology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany; (M.F.); (N.E.B.)
| | - Gregor D. Willerding
- Department of Ophthalmology, DRK Kliniken Berlin Westend, 14050 Berlin, Germany;
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Chiang MC, Chern E. Current Development, Obstacle and Futural Direction of Induced Pluripotent Stem Cell and Mesenchymal Stem Cell Treatment in Degenerative Retinal Disease. Int J Mol Sci 2022; 23:ijms23052529. [PMID: 35269671 PMCID: PMC8910526 DOI: 10.3390/ijms23052529] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 11/26/2022] Open
Abstract
Degenerative retinal disease is one of the major causes of vision loss around the world. The past several decades have witnessed emerging development of stem cell treatment for retinal disease. Nevertheless, sourcing stem cells remains controversial due to ethical concerns and their rarity. Furthermore, induced pluripotent stem cells (iPSCs) and mesenchymal stem cells (MSCs) are both isolated from patients’ mature tissues; thus, issues such as avoiding moral controversy and adverse events related to immunosuppression and obtaining a large number of cells have opened a new era in regenerative medicine. This review focuses on the current application and development, clinical trials, and latest research of stem cell therapy, as well as its limitations and future directions.
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10
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Tichotová L, Studenovska H, Petrovski G, Popelka Š, Nemesh Y, Sedláčková M, Drutovič S, Rohiwal S, Jendelová P, Erceg S, Brymová A, Artero‐Castro A, Lytvynchuk L, Straňák Z, Ellederová Z, Motlík J, Ardan T. Advantages of nanofibrous membranes for culturing of primary RPE cells compared to commercial scaffolds. Acta Ophthalmol 2021; 100:e1172-e1185. [PMID: 34687141 DOI: 10.1111/aos.15034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Dysfunction of the retinal pigment epithelium (RPE) causes numerous forms of retinal degeneration. RPE replacement is a modern option to save vision. We aimed to test the results of transplanting cultured RPEs on biocompatible membranes. METHODS We cultivated porcine primary RPE cells isolated from cadaver eyes from the slaughterhouse on two types of membranes: commercial polyester scaffolds Transwell (Corning Inc., Kenneburg, ME, USA) with 0.4 µm pore size and prepared Poly (L-lactide-co-DL-lactide) (PDLLA) nanofibrous membranes with an average pore size of 0.4 µm. RESULTS Five types of assays were used for the analysis: immunocytochemistry (ICC), phagocytosis assay, Western blotting, real-time qPCR (RT-qPCR) and electron microscopy. RT-qPCR demonstrated that RPEs cultured on nanofibrous membranes have higher expressions of BEST1 (bestrophin 1), RLBP1 (retinaldehyde-binding protein 1), RPE65 (retinal pigment epithelium-specific 65 kDa protein), PAX6 (transcription factor PAX6), SOX9 (transcription factor SOX9), DCT (dopachrome tautomerase) and MITF (microphthalmia-associated transcription factor). ICC of the RPEs cultured on nanofibrous membranes showed more intensive staining of markers such as BEST1, MCT1 (monocarboxylate transporter 1), Na+ /K+ ATPase, RPE65 and acetylated tubulin in comparison with commercial ones. Additionally, the absence of α-SMA proved the stability of the RPE polarization state and the absence of epithelial-to-mesenchymal transition. RPE possessed high phagocytic activity. Electron microscopy of both membranes confirmed a confluent layer of RPE cells and their genuine morphological structure, which was comparable to native RPEs. CONCLUSIONS Retinal pigment epitheliums cultured on polylactide nanofibrous membranes improved the final quality of the cell product by having better maturation and long-term survival of the RPE monolayer compared to those cultured on commercial polyester scaffolds. PDLLA-cultured RPEs are a plausible source for the replacement of non-functioning RPEs during cell therapy.
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Affiliation(s)
- Lucie Tichotová
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Cell Biology Faculty of Science Charles University Prague Czech Republic
| | - Hana Studenovska
- Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Goran Petrovski
- Center for Eye Research Department of Ophthalmology Oslo University Hospital and Institute for Clinical Medicine University of Oslo Oslo Norway
| | - Štěpán Popelka
- Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Yaroslav Nemesh
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Cell Biology Faculty of Science Charles University Prague Czech Republic
| | - Miroslava Sedláčková
- Department of Histology and Embryology Faculty of Medicine Masaryk University Brno Czech Republic
| | - Saskia Drutovič
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Sonali Rohiwal
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Pavla Jendelová
- Institute of Experimental Medicine Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Slaven Erceg
- Institute of Experimental Medicine Academy of Sciences of the Czech Republic Prague Czech Republic
- Stem Cell Therapies in Neurodegenerative Diseases Lab Research Center ‘Principe Felipe’ Valencia Spain
| | - Anna Brymová
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Cell Biology Faculty of Science Charles University Prague Czech Republic
| | - Ana Artero‐Castro
- Stem Cell Therapies in Neurodegenerative Diseases Lab Research Center ‘Principe Felipe’ Valencia Spain
| | - Lyubomyr Lytvynchuk
- Department of Ophthalmology Justus‐Liebig‐University Giessen University Hospital Giessen and Marburg Giessen Germany
| | - Zbyněk Straňák
- Ophthalmology Department of 3rd Faculty of Medicine Charles University and University Hospital Kralovske Vinohrady Prague Czech Republic
- Third Faculty of Medicine Charles University Prague Czech Republic
| | - Zdeňka Ellederová
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Jan Motlík
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Taras Ardan
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
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11
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Tonade D, Kern TS. Photoreceptor cells and RPE contribute to the development of diabetic retinopathy. Prog Retin Eye Res 2021; 83:100919. [PMID: 33188897 PMCID: PMC8113320 DOI: 10.1016/j.preteyeres.2020.100919] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/26/2022]
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness. It has long been regarded as vascular disease, but work in the past years has shown abnormalities also in the neural retina. Unfortunately, research on the vascular and neural abnormalities have remained largely separate, instead of being integrated into a comprehensive view of DR that includes both the neural and vascular components. Recent evidence suggests that the most predominant neural cell in the retina (photoreceptors) and the adjacent retinal pigment epithelium (RPE) play an important role in the development of vascular lesions characteristic of DR. This review summarizes evidence that the outer retina is altered in diabetes, and that photoreceptors and RPE contribute to retinal vascular alterations in the early stages of the retinopathy. The possible molecular mechanisms by which cells of the outer retina might contribute to retinal vascular damage in diabetes also are discussed. Diabetes-induced alterations in the outer retina represent a novel therapeutic target to inhibit DR.
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Affiliation(s)
- Deoye Tonade
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Timothy S Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Veterans Administration Medical Center Research Service, Cleveland, OH, USA; Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Veterans Administration Medical Center Research Service, Long Beach, CA, USA.
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12
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Guerra MH, Yumnamcha T, Ebrahim AS, Berger EA, Singh LP, Ibrahim AS. Real-Time Monitoring the Effect of Cytopathic Hypoxia on Retinal Pigment Epithelial Barrier Functionality Using Electric Cell-Substrate Impedance Sensing (ECIS) Biosensor Technology. Int J Mol Sci 2021; 22:ijms22094568. [PMID: 33925448 PMCID: PMC8123793 DOI: 10.3390/ijms22094568] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 02/06/2023] Open
Abstract
Disruption of retinal pigment epithelial (RPE barrier integrity is a hallmark feature of various retinal blinding diseases, including diabetic macular edema and age-related macular degeneration, but the underlying causes and pathophysiology are not completely well-defined. One of the most conserved phenomena in biology is the progressive decline in mitochondrial function with aging leading to cytopathic hypoxia, where cells are unable to use oxygen for energy production. Therefore, this study aimed to thoroughly investigate the role of cytopathic hypoxia in compromising the barrier functionality of RPE cells. We used Electric Cell-Substrate Impedance Sensing (ECIS) system to monitor precisely in real time the barrier integrity of RPE cell line (ARPE-19) after treatment with various concentrations of cytopathic hypoxia-inducing agent, Cobalt(II) chloride (CoCl2). We further investigated how the resistance across ARPE-19 cells changes across three separate parameters: Rb (the electrical resistance between ARPE-19 cells), α (the resistance between the ARPE-19 and its substrate), and Cm (the capacitance of the ARPE-19 cell membrane). The viability of the ARPE-19 cells and mitochondrial bioenergetics were quantified with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and seahorse technology, respectively. ECIS measurement showed that CoCl2 reduced the total impedance of ARPE-19 cells in a dose dependent manner across all tested frequencies. Specifically, the ECIS program’s modelling demonstrated that CoCl2 affected Rb as it begins to drastically decrease earlier than α or Cm, although ARPE-19 cells’ viability was not compromised. Using seahorse technology, all three concentrations of CoCl2 significantly impaired basal, maximal, and ATP-linked respirations of ARPE-19 cells but did not affect proton leak and non-mitochondrial bioenergetic. Concordantly, the expression of a major paracellular tight junction protein (ZO-1) was reduced significantly with CoCl2-treatment in a dose-dependent manner. Our data demonstrate that the ARPE-19 cells have distinct dielectric properties in response to cytopathic hypoxia in which disruption of barrier integrity between ARPE-19 cells precedes any changes in cells’ viability, cell-substrate contacts, and cell membrane permeability. Such differences can be used in screening of selective agents that improve the assembly of RPE tight junction without compromising other RPE barrier parameters.
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Affiliation(s)
- Michael H. Guerra
- Department of Ophthalmology, Visual, and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (A.-S.E.); (E.A.B.); (L.P.S.)
| | - Thangal Yumnamcha
- Department of Ophthalmology, Visual, and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (A.-S.E.); (E.A.B.); (L.P.S.)
| | - Abdul-Shukkur Ebrahim
- Department of Ophthalmology, Visual, and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (A.-S.E.); (E.A.B.); (L.P.S.)
| | - Elizabeth A. Berger
- Department of Ophthalmology, Visual, and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (A.-S.E.); (E.A.B.); (L.P.S.)
| | - Lalit Pukhrambam Singh
- Department of Ophthalmology, Visual, and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (A.-S.E.); (E.A.B.); (L.P.S.)
| | - Ahmed S. Ibrahim
- Department of Ophthalmology, Visual, and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (A.-S.E.); (E.A.B.); (L.P.S.)
- Department of Pharmacology, School of Medicine, Wayne State University, 540 East Canfield, Gordon Scott Hall (room 7133), Detroit, MI 48201, USA
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
- Correspondence: ; Tel.: +1-313-577-7854 (Office) or +1-313-577-7864 (Lab)
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Le D, Lim S, Min KW, Park JW, Kim Y, Ha T, Moon KH, Wagner KU, Kim JW. Tsg101 Is Necessary for the Establishment and Maintenance of Mouse Retinal Pigment Epithelial Cell Polarity. Mol Cells 2021; 44:168-178. [PMID: 33795534 PMCID: PMC8019596 DOI: 10.14348/molcells.2021.0027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/02/2021] [Accepted: 03/02/2021] [Indexed: 11/27/2022] Open
Abstract
The retinal pigment epithelium (RPE) forms a monolayer sheet separating the retina and choroid in vertebrate eyes. The polarized nature of RPE is maintained by distributing membrane proteins differentially along apico-basal axis. We found the distributions of these proteins differ in embryonic, post-natal, and mature mouse RPE, suggesting developmental regulation of protein trafficking. Thus, we deleted tumor susceptibility gene 101 (Tsg101), a key component of endosomal sorting complexes required for transport (ESCRT), in embryonic and mature RPE to determine whether ESCRT-mediated endocytic protein trafficking correlated with the establishment and maintenance of RPE polarity. Loss of Tsg101 severely disturbed the polarity of RPE, which forms irregular aggregates exhibiting non-polarized distribution of cell adhesion proteins and activation of epidermal growth factor receptor signaling. These findings suggest that ESCRT-mediated protein trafficking is essential for the development and maintenance of RPE cell polarity.
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Affiliation(s)
- Dai Le
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Soyeon Lim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kwang Wook Min
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Joon Woo Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Youjoung Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Taejeong Ha
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kyeong Hwan Moon
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kay-Uwe Wagner
- Department of Oncology, Wayne State University, Detroit, MI 48201, USA
| | - Jin Woo Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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14
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Singh Grewal S, Smith JJ, Carr AJF. Bestrophinopathies: perspectives on clinical disease, Bestrophin-1 function and developing therapies. Ther Adv Ophthalmol 2021; 13:2515841421997191. [PMID: 33738427 PMCID: PMC7934022 DOI: 10.1177/2515841421997191] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 01/27/2021] [Indexed: 12/17/2022] Open
Abstract
Bestrophinopathies are a group of clinically distinct inherited retinal dystrophies that typically affect the macular region, an area synonymous with central high acuity vision. This spectrum of disorders is caused by mutations in bestrophin1 (BEST1), a protein thought to act as a Ca2+-activated Cl- channel in the retinal pigment epithelium (RPE) of the eye. Although bestrophinopathies are rare, over 250 individual pathological mutations have been identified in the BEST1 gene, with many reported to have various clinical expressivity and incomplete penetrance. With no current clinical treatments available for patients with bestrophinopathies, understanding the role of BEST1 in cells and the pathological pathways underlying disease has become a priority. Induced pluripotent stem cell (iPSC) technology is helping to uncover disease mechanisms and develop treatments for RPE diseases, like bestrophinopathies. Here, we provide a comprehensive review of the pathophysiology of bestrophinopathies and highlight how patient-derived iPSC-RPE are being used to test new genomic therapies in vitro.
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Affiliation(s)
| | - Joseph J Smith
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Amanda-Jayne F Carr
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
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15
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Intartaglia D, Giamundo G, Conte I. The Impact of miRNAs in Health and Disease of Retinal Pigment Epithelium. Front Cell Dev Biol 2021; 8:589985. [PMID: 33520981 PMCID: PMC7844312 DOI: 10.3389/fcell.2020.589985] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/17/2020] [Indexed: 12/17/2022] Open
Abstract
MicroRNAs (miRNAs), a class of non-coding RNAs, are essential key players in the control of biological processes in both physiological and pathological conditions. miRNAs play important roles in fine tuning the expression of many genes, which often have roles in common molecular networks. miRNA dysregulation thus renders cells vulnerable to aberrant fluctuations in genes, resulting in degenerative diseases. The retinal pigment epithelium (RPE) is a monolayer of polarized pigmented epithelial cells that resides between the light-sensitive photoreceptors (PR) and the choriocapillaris. The demanding physiological functions of RPE cells require precise gene regulation for the maintenance of retinal homeostasis under stress conditions and the preservation of vision. Thus far, our understanding of how miRNAs function in the homeostasis and maintenance of the RPE has been poorly addressed, and advancing our knowledge is central to harnessing their potential as therapeutic agents to counteract visual impairment. This review focuses on the emerging roles of miRNAs in the function and health of the RPE and on the future exploration of miRNA-based therapeutic approaches to counteract blinding diseases.
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Affiliation(s)
| | | | - Ivan Conte
- Telethon Institute of Genetics and Medicine, Naples, Italy.,Department of Biology, Polytechnic and Basic Sciences School, University of Naples Federico II, Naples, Italy
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16
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Terheyden L, Roider J, Klettner A. Basolateral activation with TLR agonists induces polarized cytokine release and reduces barrier function in RPE in vitro. Graefes Arch Clin Exp Ophthalmol 2021; 259:413-424. [PMID: 32949301 PMCID: PMC7843481 DOI: 10.1007/s00417-020-04930-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/24/2020] [Accepted: 09/10/2020] [Indexed: 01/18/2023] Open
Abstract
PURPOSE Systemic inflammation may be of importance in the development of AMD. RPE cells can recognize danger signals with toll-like receptors (TLR) and may react in a pro-inflammatory manner. In this study, we evaluated the basal and apical secretions of TNFα, IL-6, and IL-1β in primary RPE cells and RPE/choroid explant cells under basolateral stimulation of TLR2, 3, and 4; the effects on barrier function; and their influence on neuronal cell viability. METHODS RPE/choroid tissue explants were prepared from porcine eyes and cultivated in modified Ussing chambers; primary porcine RPE cells on transwell plates. Cells were basally stimulated with agonists Pam2CSK4 (Pam; TLR2), polyinosinic/polycytidylic acid (Poly I:C; TLR3), and lipopolysaccharide (LPS; TLR4) for 24 h. Supernatants were evaluated with ELISA for cytokines TNFα, IL-6, and IL-1β. Apical supernatants were applied to SHSY-5Y cells, and cell viability was evaluated in MTT assay. Barrier function was tested by measuring transepithelial electrical resistance (TER) and occludin immunostaining. RESULTS None of the tested TLR agonists was toxic on RPE cells after 24 h of exposure. Unstimulated RPE cells secreted hardly any cytokines. Pam induced IL-6, IL-1ß, and TNFα on the basal and apical sides at all concentrations tested. Poly I:C induced IL-6 and TNFα primarily at the basal side at lower but on both sides at higher concentrations. LPS induced IL-6, IL-1ß, and TNFα apically and basally at all concentrations tested. In the RPE/choroid, a strong difference between apical and basal secretions could be found. IL-6 was constitutively secreted basally, but not apically, but was induced by all agonists on both sides. IL-1ß and TNFα alpha were strongly induced on the basal side by all agonists. TER was reduced by all agonists, with Pam and LPS being effective in all concentrations tested. Occludin expression was unaltered, but the distribution was influenced by the agonists, with a less distinct localization at the cell borders after treatment. None of the agonists or supernatants of treated RPE and RPE/choroid organ cultures exerted any effect on viability of SHSY-5Y cells. CONCLUSIONS Danger signals activating TLRs can induce polarized cytokine expression and contribute to the loss of barrier function in the RPE.
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Affiliation(s)
- Laura Terheyden
- grid.9764.c0000 0001 2153 9986University Medical Center, Department of Ophthalmology, University of Kiel, Arnold-Heller-Str. 3, Haus B2, 24105 Kiel, Germany
| | - Johann Roider
- grid.9764.c0000 0001 2153 9986University Medical Center, Department of Ophthalmology, University of Kiel, Arnold-Heller-Str. 3, Haus B2, 24105 Kiel, Germany
| | - Alexa Klettner
- grid.9764.c0000 0001 2153 9986University Medical Center, Department of Ophthalmology, University of Kiel, Arnold-Heller-Str. 3, Haus B2, 24105 Kiel, Germany
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17
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The Effects of Prolonged Storage on ARPE-19 Cells Stored at Three Different Storage Temperatures. Molecules 2020; 25:molecules25245809. [PMID: 33317020 PMCID: PMC7763992 DOI: 10.3390/molecules25245809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/29/2020] [Accepted: 12/04/2020] [Indexed: 12/02/2022] Open
Abstract
This study aimed to investigate how prolonged storage of adult retinal pigment epithelial (ARPE-19) cell sheets affects cell metabolism, morphology, viability, and phenotype. ARPE-19 cell sheets were stored at three temperatures (4 °C, 16 °C, and 37 °C) for three weeks. Metabolic status and morphology of the cells were monitored by sampling medium and examining cells by phase-contrast microscopy, respectively, throughout the storage period. Cell viability was analyzed by flow cytometry, and phenotype was determined by epifluorescence microscopy after the storage. Lactate production and glucose consumption increased heavily, while pH dropped considerably, through storage at 37 °C compared to 4 °C and 16 °C. During storage, morphology started to deteriorate first at 4 °C, then at 37 °C, and was maintained the longest at 16 °C. Viability of the cells after three weeks of storage was best preserved at 16 °C, while cells stored at 4 °C and 37 °C had reduced viability. Dedifferentiation indicated by reduced expression of retinal pigment epithelium-specific protein 65 (RPE65), zonula occludens protein 1 (ZO-1), and occludin after three weeks of storage was noticed in all experimental groups compared to control. We conclude that storage temperature affects the metabolic status of ARPE-19 cells and that 16 °C reduces metabolic activity while protecting viability and morphology.
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18
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Bermond K, Wobbe C, Tarau IS, Heintzmann R, Hillenkamp J, Curcio CA, Sloan KR, Ach T. Autofluorescent Granules of the Human Retinal Pigment Epithelium: Phenotypes, Intracellular Distribution, and Age-Related Topography. Invest Ophthalmol Vis Sci 2020; 61:35. [PMID: 32433758 PMCID: PMC7405767 DOI: 10.1167/iovs.61.5.35] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The human retinal pigment epithelium (RPE) accumulates granules significant for autofluorescence imaging. Knowledge of intracellular accumulation and distribution is limited. Using high-resolution microscopy techniques, we determined the total number of granules per cell, intracellular distribution, and changes related to retinal topography and age. Methods RPE cells from the fovea, perifovea, and near-periphery of 15 human RPE flat mounts were imaged using structured illumination microscopy (SIM) and confocal fluorescence microscopy in young (≤51 years, n = 8) and older (>80 years, n = 7) donors. Using custom FIJI plugins, granules were marked with computer assistance, classified based on morphological and autofluorescence properties, and analyzed with regard to intracellular distribution, total number per cell, and granule density. Results A total of 193,096 granules in 450 RPE cell bodies were analyzed. Based on autofluorescence properties, size, and composition, the RPE granules exhibited nine different phenotypes (lipofuscin, two; melanolipofuscin, five; melanosomes, two), distinguishable by SIM. Overall, lipofuscin (low at the fovea but increases with eccentricity and age) and melanolipofuscin (equally distributed at all three locations with no age-related changes) were the major granule types. Melanosomes were under-represented due to suboptimal visualization of apical processes in flat mounts. Conclusions Low lipofuscin and high melanolipofuscin content within foveal RPE cell bodies and abundant lipofuscin at the perifovea suggest a different genesis, plausibly related to the population of overlying photoreceptors (fovea, cones only; perifovea, highest rod density). This systematic analysis provides further insight into RPE cell and granule physiology and links granule load to cell autofluorescence, providing a subcellular basis for the interpretation of clinical fundus autofluorescence.
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Vigouroux RJ, Cesar Q, Chédotal A, Nguyen-Ba-Charvet KT. Revisiting the role of Dcc in visual system development with a novel eye clearing method. eLife 2020; 9:51275. [PMID: 32096760 PMCID: PMC7062470 DOI: 10.7554/elife.51275] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 02/24/2020] [Indexed: 12/22/2022] Open
Abstract
The Deleted in Colorectal Carcinoma (Dcc) receptor plays a critical role in optic nerve development. Whilst Dcc is expressed postnatally in the eye, its function remains unknown as Dcc knockouts die at birth. To circumvent this drawback, we generated an eye-specific Dcc mutant. To study the organization of the retina and visual projections in these mice, we also established EyeDISCO, a novel tissue clearing protocol that removes melanin allowing 3D imaging of whole eyes and visual pathways. We show that in the absence of Dcc, some ganglion cell axons stalled at the optic disc, whereas others perforated the retina, separating photoreceptors from the retinal pigment epithelium. A subset of visual axons entered the CNS, but these projections are perturbed. Moreover, Dcc-deficient retinas displayed a massive postnatal loss of retinal ganglion cells and a large fraction of photoreceptors. Thus, Dcc is essential for the development and maintenance of the retina.
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Affiliation(s)
- Robin J Vigouroux
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Quénol Cesar
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Alain Chédotal
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
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Chen X, Jiang C, Sun R, Yang D, Liu Q. Circular Noncoding RNA NR3C1 Acts as a miR-382-5p Sponge to Protect RPE Functions via Regulating PTEN/AKT/mTOR Signaling Pathway. Mol Ther 2020; 28:929-945. [PMID: 32017889 DOI: 10.1016/j.ymthe.2020.01.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/22/2019] [Accepted: 01/01/2020] [Indexed: 11/20/2022] Open
Abstract
Age-related macular degeneration (AMD) is a universal leading cause for irreversible blindness in the elderly population. Dedifferentiation of retinal pigment epithelium (RPE) cells initiates early pathological events in atrophic AMD. Herein, we aim to investigate effects of a circular RNA derived from the NR3C1 gene (circNR3C1) on regulating RPE function and AMD pathogenesis. circNR3C1 expression was consistently upregulated along with RPE differentiation and was downregulated in dysfunctional RPE and blood serum of AMD patients. Silencing of circNR3C1 reduced RPE characteristic transcripts and proteins, interrupted phagocytosis, accelerated intracellular reactive oxygen species (ROS) generation, and promoted RPE proliferation in vitro. circN3C1 silencing also decreased expressions of RPE characteristic markers and disturbed the ultrastructure of RPE in vivo, as shown by a thickened RPE with twisted basal infoldings and outer segments. Mechanistically, circNR3C1 acted as an endogenous microRNA-382-5p (miR-382-5p) sponge to sequester its activity, which increased phosphatase and tensin homolog on chromosome 10 (PTEN) expression and inhibited the protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway. miR-382-5p overexpression and PTEN silencing mimicked effects of circNR3C1 silencing on RPE phenotypes in vivo and in vitro. In conclusion, circNR3C1 prevents AMD progression and protects RPE by directly sponging miR-382-5p to block its interaction with PTEN and subsequently blocks the AKT/mTOR pathway. Pharmacological circNR3C1 supplementations are promising therapeutic options for atrophic AMD.
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Affiliation(s)
- Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Chao Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Ruxu Sun
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Daidi Yang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China.
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Gandhi JK, Mano F, Iezzi R, LoBue SA, Holman BH, Fautsch MP, Olsen TW, Pulido JS, Marmorstein AD. Fibrin hydrogels are safe, degradable scaffolds for sub-retinal implantation. PLoS One 2020; 15:e0227641. [PMID: 31929571 PMCID: PMC6957177 DOI: 10.1371/journal.pone.0227641] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/23/2019] [Indexed: 01/26/2023] Open
Abstract
Retinal pigment epithelium (RPE) transplantation for the treatment of macular degeneration has been studied for over 30 years. Human clinical trials have demonstrated that RPE monolayers exhibit improved cellular engraftment and survival compared to single cell suspensions. The use of a scaffold facilitates implantation of a flat, wrinkle-free, precisely placed monolayer. Scaffolds currently being investigated in human clinical trials are non-degradable which results in the introduction of a chronic foreign body. To improve RPE transplant technology, a degradable scaffold would be desirable. Using human fibrin, we have generated scaffolds that support the growth of an RPE monolayer in vitro. To determine whether these scaffolds are degraded in vivo, we developed a surgical approach that delivers a fibrin hydrogel implant to the sub-retinal space of the pig eye and determined whether and how fast they degraded. Using standard ophthalmic imaging techniques, the fibrin scaffolds were completely degraded by postoperative week 8 in 5 of 6 animals. Postmortem histologic analysis confirmed the absence of the scaffold from the subretinal space at 8 weeks, and demonstrated the reattachment of the neurosensory retina and a normal RPE–photoreceptor interface. When mechanical debridement of a region of native RPE was performed during implantation surgery degradation was accelerated and scaffolds were undetectable by 4 weeks. These data represent the first in situ demonstration of a fully biodegradable scaffold for use in the implantation of RPE and other cell types for treatment of macular degeneration and other retinal degenerative diseases.
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Affiliation(s)
- Jarel K. Gandhi
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Fukutaro Mano
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Raymond Iezzi
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Stephen A. LoBue
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Brad H. Holman
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Michael P. Fautsch
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Timothy W. Olsen
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Jose S. Pulido
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Alan D. Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America
- * E-mail:
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22
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Lopes de Faria JM, Duarte DA, Simó R, García-Ramirez M, Dátilo MN, Pasqualetto FC, Lopes de Faria JB. δ Opioid Receptor Agonism Preserves the Retinal Pigmented Epithelial Cell Tight Junctions and Ameliorates the Retinopathy in Experimental Diabetes. Invest Ophthalmol Vis Sci 2020; 60:3842-3853. [PMID: 31529081 DOI: 10.1167/iovs.19-26761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Outer blood retinal barrier breakdown is a neglected feature of diabetic retinopathy (DR). We demonstrated that the agonism of the δ opioid receptor (DOR) by epicatechin preserves the tight junction proteins in ARPE-19 cells under diabetic conditions. Presently, we aimed to evaluate the possible role of the DOR on the maintenance of tight junction of RPE layer and on the early markers of experimental DR. Methods DR markers and external retinal tight junction proteins were evaluated in CL57B diabetic mice submitted to intravitreous injection of short hairpin RNA (shRNA)-DOR (108 transducing units [TU]/mL) treated or not with DOR agonist (0.05 g/animal/d of epicatechin in drinking water) for 16 weeks. The presence of DOR in human retina from postmortem eyes from diabetic and nondiabetic donors were also performed. Results DOR is present in RPE layer and in neuro retina. The treatment with DOR agonist prevented the upregulation of the early markers of retinopathy (glial fibrillary acidic protein, VEGF) and the downregulation of pigment epithelium-derived factor, occludin, claudin-1, and zonula occludens-1 tight junction expressions. The silencing of DOR in retina of diabetic mice partially abolished the protective effects of epicatechin. In human retina specimens, DOR is present throughout the retina, similarly in nondiabetic and diabetic donors. Conclusions This set of experiments strongly indicates that the DOR agonism preserves RPE tight junctions and reduces the early markers of retinopathy in model of diabetes. These novel findings designate DOR as a potential therapeutic tool to treat DR with preservation of the RPE tight junction proteins.
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Affiliation(s)
- Jacqueline M Lopes de Faria
- Renal Pathophysiology Laboratory, Investigation on Diabetes Complications, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Diego A Duarte
- Renal Pathophysiology Laboratory, Investigation on Diabetes Complications, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Rafael Simó
- Vall d'Hebron Research Institute (VHIR) and CIBERDEM, Barcelona, Spain
| | | | - Marcella N Dátilo
- Renal Pathophysiology Laboratory, Investigation on Diabetes Complications, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil
| | - Francieli C Pasqualetto
- Renal Pathophysiology Laboratory, Investigation on Diabetes Complications, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil
| | - José B Lopes de Faria
- Renal Pathophysiology Laboratory, Investigation on Diabetes Complications, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, Brazil
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23
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CFH exerts anti-oxidant effects on retinal pigment epithelial cells independently from protecting against membrane attack complex. Sci Rep 2019; 9:13873. [PMID: 31554875 PMCID: PMC6761137 DOI: 10.1038/s41598-019-50420-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/20/2019] [Indexed: 12/03/2022] Open
Abstract
Age Related Macular Degeneration (AMD) is the first cause of social blindness in people aged over 65 leading to atrophy of retinal pigment epithelial cells (RPE), photoreceptors and choroids, eventually associated with choroidal neovascularization. Accumulation of undigested cellular debris within RPE cells or under the RPE (Drusen), oxidative stress and inflammatory mediators contribute to the RPE cell death. The major risk to develop AMD is the Y402H polymorphism of complement factor H (CFH). CFH interacting with oxidized phospholipids on the RPE membrane modulates the functions of these cells, but the exact role of CFH in RPE cell death and survival remain poorly understood. The aim of this study was to analyze the potential protective mechanism of CFH on RPE cells submitted to oxidative stress. Upon exposure to oxidized lipids 4-HNE (4-hydroxy-2-nonenal) derived from photoreceptors, both the human RPE cell line ARPE-19 and RPE cells derived from human induced pluripotent stem cells were protected from death only in the presence of the full length human recombinant CFH in the culture medium. This protective effect was independent from the membrane attack complex (MAC) formation. CFH maintained RPE cells tight junctions’ structure and regulated the caspase dependent apoptosis process. These results demonstrated the CFH anti-oxidative stress functions independently of its capacity to inhibit MAC formation.
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Achberger K, Probst C, Haderspeck J, Bolz S, Rogal J, Chuchuy J, Nikolova M, Cora V, Antkowiak L, Haq W, Shen N, Schenke-Layland K, Ueffing M, Liebau S, Loskill P. Merging organoid and organ-on-a-chip technology to generate complex multi-layer tissue models in a human retina-on-a-chip platform. eLife 2019; 8:46188. [PMID: 31451149 PMCID: PMC6777939 DOI: 10.7554/elife.46188] [Citation(s) in RCA: 210] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 08/06/2019] [Indexed: 12/17/2022] Open
Abstract
The devastating effects and incurable nature of hereditary and sporadic retinal diseases such as Stargardt disease, age-related macular degeneration or retinitis pigmentosa urgently require the development of new therapeutic strategies. Additionally, a high prevalence of retinal toxicities is becoming more and more an issue of novel targeted therapeutic agents. Ophthalmologic drug development, to date, largely relies on animal models, which often do not provide results that are translatable to human patients. Hence, the establishment of sophisticated human tissue-based in vitro models is of upmost importance. The discovery of self-forming retinal organoids (ROs) derived from human embryonic stem cells (hESCs) or human induced pluripotent stem cells (hiPSCs) is a promising approach to model the complex stratified retinal tissue. Yet, ROs lack vascularization and cannot recapitulate the important physiological interactions of matured photoreceptors and the retinal pigment epithelium (RPE). In this study, we present the retina-on-a-chip (RoC), a novel microphysiological model of the human retina integrating more than seven different essential retinal cell types derived from hiPSCs. It provides vasculature-like perfusion and enables, for the first time, the recapitulation of the interaction of mature photoreceptor segments with RPE in vitro. We show that this interaction enhances the formation of outer segment-like structures and the establishment of in vivo-like physiological processes such as outer segment phagocytosis and calcium dynamics. In addition, we demonstrate the applicability of the RoC for drug testing, by reproducing the retinopathic side-effects of the anti-malaria drug chloroquine and the antibiotic gentamicin. The developed hiPSC-based RoC has the potential to promote drug development and provide new insights into the underlying pathology of retinal diseases.
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Affiliation(s)
- Kevin Achberger
- Institute of Neuroanatomy & Developmental Biology (INDB), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Christopher Probst
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany
| | - Jasmin Haderspeck
- Institute of Neuroanatomy & Developmental Biology (INDB), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Sylvia Bolz
- Centre for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Julia Rogal
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany.,Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Johanna Chuchuy
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany.,Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Marina Nikolova
- Institute of Neuroanatomy & Developmental Biology (INDB), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Virginia Cora
- Institute of Neuroanatomy & Developmental Biology (INDB), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Lena Antkowiak
- Institute of Neuroanatomy & Developmental Biology (INDB), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Wadood Haq
- Centre for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Nian Shen
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Katja Schenke-Layland
- Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany.,Natural and Medical Sciences Institute (NMI), Reutlingen, Germany.,Department of Medicine/Cardiology, Cardiovascular Research Laboratories, David Geffen School of Medicine, Los Angeles, United States
| | - Marius Ueffing
- Centre for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Stefan Liebau
- Institute of Neuroanatomy & Developmental Biology (INDB), Eberhard Karls University Tübingen, Tübingen, Germany
| | - Peter Loskill
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Stuttgart, Germany.,Department of Women's Health, Research Institute for Women's Health, Eberhard Karls University Tübingen, Tübingen, Germany
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25
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The Cytoskeleton of the Retinal Pigment Epithelium: from Normal Aging to Age-Related Macular Degeneration. Int J Mol Sci 2019; 20:ijms20143578. [PMID: 31336621 PMCID: PMC6678077 DOI: 10.3390/ijms20143578] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/15/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022] Open
Abstract
The retinal pigment epithelium (RPE) is a unique epithelium, with major roles which are essential in the visual cycle and homeostasis of the outer retina. The RPE is a monolayer of polygonal and pigmented cells strategically placed between the neuroretina and Bruch membrane, adjacent to the fenestrated capillaries of the choriocapillaris. It shows strong apical (towards photoreceptors) to basal/basolateral (towards Bruch membrane) polarization. Multiple functions are bound to a complex structure of highly organized and polarized intracellular components: the cytoskeleton. A strong connection between the intracellular cytoskeleton and extracellular matrix is indispensable to maintaining the function of the RPE and thus, the photoreceptors. Impairments of these intracellular structures and the regular architecture they maintain often result in a disrupted cytoskeleton, which can be found in many retinal diseases, including age-related macular degeneration (AMD). This review article will give an overview of current knowledge on the molecules and proteins involved in cytoskeleton formation in cells, including RPE and how the cytoskeleton is affected under stress conditions—especially in AMD.
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Akhtar T, Xie H, Khan MI, Zhao H, Bao J, Zhang M, Xue T. Accelerated photoreceptor differentiation of hiPSC-derived retinal organoids by contact co-culture with retinal pigment epithelium. Stem Cell Res 2019; 39:101491. [PMID: 31326746 DOI: 10.1016/j.scr.2019.101491] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 06/19/2019] [Accepted: 06/25/2019] [Indexed: 12/29/2022] Open
Abstract
Retinal organoids (ROs) derived from human-induced pluripotent stem cells recapitulate the three-dimensional structure of retina, mimic human retinal development, and provide cell sources for pre-clinical retinal transplantation. Retinal pigment epithelium (RPE) is crucial for normal outer retinal physiology, including phagocytosis of shed photoreceptor outer segments and secretion of neurotrophic and vasculotrophic growth factors. However, whether ROs-RPE co-culture can improve the differentiation of photoreceptors in ROs in vitro remains unknown. Herein, primary mouse RPE cells were contact co-cultured with ROs at different time points. Our results revealed that the RPE cells accelerated photoreceptor differentiation in ROs, as the cross talk between the RPE and ROs promoted the stage specific expression of photoreceptor markers at different differentiation stages. Thus, we established an improved co-culture system based on modeling of human retina-RPE dynamics during retinogenesis for the evaluation of ocular therapies.
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Affiliation(s)
- Tasneem Akhtar
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Haohuan Xie
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Muhammad Imran Khan
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Huan Zhao
- Department of Biological and Environmental Engineering, Hefei University, Hefei 230601, China
| | - Jin Bao
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China
| | - Mei Zhang
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China.
| | - Tian Xue
- Eye Center, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Neurodegenerative Disorder Research Center, Chinese Academy of Sciences Key Laboratory of Brain Function and Disease, School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230026, China; Chinese Academy of Sciences Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China.
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27
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König S, Hadrian K, Schlatt S, Wistuba J, Thanos S, Böhm M. Topographic protein profiling of the age-related proteome in the retinal pigment epithelium of Callithrix jacchus with respect to macular degeneration. J Proteomics 2019; 191:1-15. [DOI: 10.1016/j.jprot.2018.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/12/2018] [Accepted: 05/28/2018] [Indexed: 12/27/2022]
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28
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Potential Interplay between Hyperosmolarity and Inflammation on Retinal Pigmented Epithelium in Pathogenesis of Diabetic Retinopathy. Int J Mol Sci 2018; 19:ijms19041056. [PMID: 29614818 PMCID: PMC5979527 DOI: 10.3390/ijms19041056] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 03/21/2018] [Accepted: 03/30/2018] [Indexed: 12/15/2022] Open
Abstract
Diabetic retinopathy is a frequent eyesight threatening complication of type 1 and type 2 diabetes. Under physiological conditions, the inner and the outer blood-retinal barriers protect the retina by regulating ion, protein, and water flux into and out of the retina. During diabetic retinopathy, many factors, including inflammation, contribute to the rupture of the inner and/or the outer blood-retinal barrier. This rupture leads the development of macular edema, a foremost cause of sight loss among diabetic patients. Under these conditions, it has been speculated that retinal pigmented epithelial cells, that constitute the outer blood-retinal barrier, may be subjected to hyperosmolar stress resulting from different mechanisms. Herein, we review the possible origins and consequences of hyperosmolar stress on retinal pigmented epithelial cells during diabetic retinopathy, with a special focus on the intimate interplay between inflammation and hyperosmolar stress, as well as the current and forthcoming new pharmacotherapies for the treatment of such condition.
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29
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Jovancevic N, Khalfaoui S, Weinrich M, Weidinger D, Simon A, Kalbe B, Kernt M, Kampik A, Gisselmann G, Gelis L, Hatt H. Odorant Receptor 51E2 Agonist β-ionone Regulates RPE Cell Migration and Proliferation. Front Physiol 2017; 8:888. [PMID: 29249973 PMCID: PMC5714887 DOI: 10.3389/fphys.2017.00888] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/19/2017] [Indexed: 01/09/2023] Open
Abstract
The odorant receptor 51E2 (OR51E2), which is well-characterized in prostate cancer cells and epidermal pigment cells, was identified for the first time as the most highly expressed OR in human fetal and adult retinal pigment epithelial (RPE) cells. Immunofluorescence staining and Western blot analysis revealed OR51E2 localization throughout the cytosol and in the plasma membrane. Additionally, immunohistochemical staining of diverse layers of the eye showed that the expression of OR51E2 is restricted to the pigment cells of the RPE and choroid. The results of Ca2+-imaging experiments demonstrate that activation of OR51E2 triggers a Ca2+ dependent signal pathway in RPE cells. Downstream signaling of OR51E2 involves the activation of adenylyl cyclase, ERK1/2 and AKT. The activity of these protein kinases likely accounts for the demonstrated increase in the migration and proliferation of RPE cells upon stimulation with the OR51E2 ligand β-ionone. These findings suggest that OR51E2 is involved in the regulation of RPE cell growth. Thus, OR51E2 represents a potential target for the treatment of proliferative disorders.
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Affiliation(s)
| | | | | | | | - Annika Simon
- Cell Physiology, Ruhr-University Bochum, Bochum, Germany
| | - Benjamin Kalbe
- Cell Physiology, Ruhr-University Bochum, Bochum, Germany
| | - Marcus Kernt
- Ophthalmology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Anselm Kampik
- Ophthalmology, Ludwig Maximilian University of Munich, Munich, Germany
| | | | - Lian Gelis
- Cell Physiology, Ruhr-University Bochum, Bochum, Germany
| | - Hanns Hatt
- Cell Physiology, Ruhr-University Bochum, Bochum, Germany
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30
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Assiri AM, El-Beeh ME, Amin AH, Ramadan MF. Ameliorative impact of Morus alba leaves’ aqueous extract against embryonic ophthalmic tissue malformation in streptozotocin-induced diabetic rats. Biomed Pharmacother 2017; 95:1072-1081. [DOI: 10.1016/j.biopha.2017.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/12/2017] [Accepted: 09/06/2017] [Indexed: 12/30/2022] Open
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31
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Ismail EN, Ruberti JW, Malek G. Quick-freeze/deep-etch electron microscopy visualization of the mouse posterior pole. Exp Eye Res 2017. [PMID: 28629927 DOI: 10.1016/j.exer.2017.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The mouse is one of the most commonly used mammalian systems to study human diseases. In particular it has been an invaluable tool to model a multitude of ocular pathologies affecting the posterior pole. The aim of this study was to create a comprehensive map of the ultrastructure of the mouse posterior pole using the quick-freeze/deep-etch method (QFDE). QFDE can produce detailed three-dimensional images of tissue structure and macromolecular moieties, without many of the artifacts introduced by structure-altering post-processing methods necessary to perform conventional transmission electron microscopy (cTEM). A total of 18 eyes from aged C57BL6/J mice were enucleated and the posterior poles were processed, either intact or with the retinal pigment epithelium (RPE) cell layer removed, for imaging by either QFDE or cTEM. QFDE images were correlated with cTEM cross-sections and en face images through the outer retina. Nicely preserved outer retinal architecture was observed with both methods, however, QFDE provided excellent high magnification imaging, with greater detail, of the apical, central, and basal planes of the RPE. Furthermore, key landmarks within Bruch's membrane, choriocapillaris, choroid and sclera were characterized and identified. In this study we developed methods for preparing the outer retina of the mouse for evaluation with QFDE and provide a map of the ultrastructure and cellular composition of the outer posterior pole. This technique should be applicable for morphological evaluation of mouse models, in which detailed visualization of subtle ocular structural changes is needed or in cases where post-processing methods introduce unacceptable artifacts.
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Affiliation(s)
- Ebraheim N Ismail
- Department of Bioengineering, Northeastern University, Boston, MA, United States
| | - Jeffrey W Ruberti
- Department of Bioengineering, Northeastern University, Boston, MA, United States; Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, MA, United States.
| | - Goldis Malek
- Departments of Ophthalmology and Pathology, Duke University School of Medicine, Durham, NC, United States.
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32
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Mislocalisation of BEST1 in iPSC-derived retinal pigment epithelial cells from a family with autosomal dominant vitreoretinochoroidopathy (ADVIRC). Sci Rep 2016; 6:33792. [PMID: 27653836 PMCID: PMC5031956 DOI: 10.1038/srep33792] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/26/2016] [Indexed: 12/31/2022] Open
Abstract
Autosomal dominant vitreoretinochoroidopathy (ADVIRC) is a rare, early-onset retinal dystrophy characterised by distinct bands of circumferential pigmentary degeneration in the peripheral retina and developmental eye defects. ADVIRC is caused by mutations in the Bestrophin1 (BEST1) gene, which encodes a transmembrane protein thought to function as an ion channel in the basolateral membrane of retinal pigment epithelial (RPE) cells. Previous studies suggest that the distinct ADVIRC phenotype results from alternative splicing of BEST1 pre-mRNA. Here, we have used induced pluripotent stem cell (iPSC) technology to investigate the effects of an ADVIRC associated BEST1 mutation (c.704T > C, p.V235A) in patient-derived iPSC-RPE. We found no evidence of alternate splicing of the BEST1 transcript in ADVIRC iPSC-RPE, however in patient-derived iPSC-RPE, BEST1 was expressed at the basolateral membrane and the apical membrane. During human eye development we show that BEST1 is expressed more abundantly in peripheral RPE compared to central RPE and is also expressed in cells of the developing retina. These results suggest that higher levels of mislocalised BEST1 expression in the periphery, from an early developmental stage, could provide a mechanism that leads to the distinct clinical phenotype observed in ADVIRC patients.
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33
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Cashman SM, Gracias J, Adhi M, Kumar-Singh R. Adenovirus-mediated delivery of Factor H attenuates complement C3 induced pathology in the murine retina: a potential gene therapy for age-related macular degeneration. J Gene Med 2016; 17:229-43. [PMID: 26369397 DOI: 10.1002/jgm.2865] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 08/19/2015] [Accepted: 09/11/2015] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is the most common cause of blindness in the elderly, with no therapy available for 90% of patients. Recent genetic evidence implicates activation of complement in the pathogenesis of AMD. We have recently discovered that adenovirus (Ad)-mediated expression of complement component C3 (AdCMVC3) in the murine retina recapitulates many of the pathological features found in human AMD. In the present study, utilizing a gene therapy approach, we examine whether Ad-mediated expression of complement Factor H (AdCAGfH) attenuates AdCMVC3-mediated retinal pathology. METHODS AdCMVC3 was co-injected with either AdCAGfH or a negative control virus expressing green fluorescent protein (AdCMVGFP) into the subretinal space of adult mice. The resulting retinal pathology was analyzed by histology and immunocytochemistry and retinal function was quantified by electroretinography. RESULTS Morphological and functional analyses indicated that AdCMVC3-mediated retinal pathology could be attenuated by AdCAGfH. Specifically, endothelial cell proliferation was reduced by 91% and atrophy of retinal pigment epithelium (RPE) could be attenuated by 69%. AdCAGfH injected eyes exhibited 90-150% greater A-wave and 120-180% greater B-wave amplitudes relative to control eyes. Immunocytochemical analysis of rhodopsin and RPE65 was consistent with the rescue of photoreceptors and RPE in AdCAGfH injected eyes. CONCLUSIONS C3-induced pathology in murine retina can be attenuated by Ad-mediated expression of Factor H. Expression of Factor H is worthy of further study as a potential gene therapy for AMD.
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Affiliation(s)
- Siobhan M Cashman
- Department of Developmental, Molecular and Chemical Biology and the Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA
| | - Jessica Gracias
- Department of Developmental, Molecular and Chemical Biology and the Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA
| | - Mehreen Adhi
- Department of Developmental, Molecular and Chemical Biology and the Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA
| | - Rajendra Kumar-Singh
- Department of Developmental, Molecular and Chemical Biology and the Department of Ophthalmology, Tufts University School of Medicine, Boston, MA, USA
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34
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Bales KL, Gross AK. Aberrant protein trafficking in retinal degenerations: The initial phase of retinal remodeling. Exp Eye Res 2015; 150:71-80. [PMID: 26632497 DOI: 10.1016/j.exer.2015.11.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 11/04/2015] [Accepted: 11/09/2015] [Indexed: 12/18/2022]
Abstract
Retinal trafficking proteins are involved in molecular assemblies that govern protein transport, orchestrate cellular events involved in cilia formation, regulate signal transduction, autophagy and endocytic trafficking, all of which if not properly controlled initiate retinal degeneration. Improper function and or trafficking of these proteins and molecular networks they are involved in cause a detrimental cascade of neural retinal remodeling due to cell death, resulting as devastating blinding diseases. A universal finding in retinal degenerative diseases is the profound detection of retinal remodeling, occurring as a phased modification of neural retinal function and structure, which begins at the molecular level. Retinal remodeling instigated by aberrant trafficking of proteins encompasses many forms of retinal degenerations, such as the diverse forms of retinitis pigmentosa (RP) and disorders that resemble RP through mutations in the rhodopsin gene, retinal ciliopathies, and some forms of glaucoma and age-related macular degeneration (AMD). As a large majority of genes associated with these different retinopathies are overlapping, it is imperative to understand their underlying molecular mechanisms. This review will discuss some of the most recent discoveries in vertebrate retinal remodeling and retinal degenerations caused by protein mistrafficking.
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Affiliation(s)
- Katie L Bales
- University of Alabama at Birmingham, Birmingham, AL, United States
| | - Alecia K Gross
- University of Alabama at Birmingham, Birmingham, AL, United States.
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35
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Bose K, Lakshminarasimhan H, Sundar K, Kathiresan T. Cytotoxic effect of ZnS nanoparticles on primary mouse retinal pigment epithelial cells. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2015; 44:1764-73. [PMID: 26523428 DOI: 10.3109/21691401.2015.1102739] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The multiple properties of zinc sulphide nanoparticles (ZnS-NPs) are attracting great attention in the field of chemical and biological research. ZnS-NPs also find their application in biosensor and photocatalysis. Zinc is an important metal ion in retina and its deficiency leads to age-related macular degeneration. As of now, not much research is available on bio-interaction of ZnS as nanoform with retinal pigment epithelial (RPE) cells. RPE cells in the retina help in maintaining normal photoreceptor function and vision. To begin with, ZnS-NPs were synthesized and characterized using UV-visible spectra, X-ray diffraction, Fourier transform infrared spectrum, transmission electron microscopy and dynamic light scattering. Followed by the confirmation of nanoparticles, our study extended to investigate the impact of ZnS-NPs in primary mouse RPE (MRPE) cells at different concentrations. ZnS-NPs showed dose-dependent cytotoxicity in MRPE cells and no changes were observed in cells' tight intactness at minimal concentration. In addition, exposure to ZnS-NPs increased cellular permeability in dose- and time-dependent manner in MRPE cells. The findings from DCFH-DA analysis revealed that ZnS-NPs-treated cells had elevated level of reactive oxygen species and partial activation of cell apoptosis was identified after exposure to ZnS-NPs at higher concentration. Furthermore, pre-treatment of the primary MRPE cells with ZnS-NPs led to phosphorylation of Akt (Ser 473), which indicates the crucial role of ZnS-NPs in regulating cell survival at minimal concentration. Altogether, this study enumerates requisite dose of using ZnS-NPs to maintain healthy RPE cells and contributes to future studies in development of therapeutic drug and drug carrier for ocular-related disorders.
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Affiliation(s)
- Karthikeyan Bose
- a Department of Biotechnology , Kalasalingam University , Krishnankoil , Tamil Nadu , India
| | | | - Krishnan Sundar
- a Department of Biotechnology , Kalasalingam University , Krishnankoil , Tamil Nadu , India.,b International Research Centre, Kalasalingam University , Krishnankoil , Tamil Nadu , India
| | - Thandavarayan Kathiresan
- a Department of Biotechnology , Kalasalingam University , Krishnankoil , Tamil Nadu , India.,b International Research Centre, Kalasalingam University , Krishnankoil , Tamil Nadu , India
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36
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Paniagua AE, Herranz-Martín S, Jimeno D, Jimeno ÁM, López-Benito S, Carlos Arévalo J, Velasco A, Aijón J, Lillo C. CRB2 completes a fully expressed Crumbs complex in the Retinal Pigment Epithelium. Sci Rep 2015; 5:14504. [PMID: 26404741 PMCID: PMC4585915 DOI: 10.1038/srep14504] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 08/26/2015] [Indexed: 11/24/2022] Open
Abstract
The CRB proteins CRB1, CRB2 and CRB3 are members of the cell polarity complex Crumbs in mammals that together with Scribble and Par complexes stablish the polarity of a variety of cell types. Although many members of the Crumbs complex proteins are expressed in the retinal pigment epithelium (RPE), and even though the mRNA of CRB2 has been detected in ARPE-19 cells and in the RPE/Choroid, to date no CRB protein has yet been found in this tissue. To investigate this possibility, we generated an antibody that specifically recognize the mouse CRB2 protein, and we demonstrate the expression of CRB2 in mouse RPE. Confocal analysis shows that CRB2 is restricted to the apicolateral membrane of RPE cells, and more precisely, in the tight junctions. Our study identified CRB2 as the member of the CRB protein family that is present together with the rest of the components of the Crumbs complex in the RPE apico-lateral cell membrane. Considering that the functions of CRB proteins are decisive in the establishment and maintenance of cell-cell junctions in several epithelial-derived cell types, we believe that these findings are a relevant starting point for unraveling the functions that CRB2 might perform in the RPE.
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Affiliation(s)
- Antonio E Paniagua
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Saúl Herranz-Martín
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - David Jimeno
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Ángela M Jimeno
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Saray López-Benito
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Juan Carlos Arévalo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Almudena Velasco
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - José Aijón
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Concepción Lillo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
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Abstract
Genetic studies have linked alterations in Kir7.1 channel to diverse pathologies. We summarize functional relevance of Kir7.1 channel in retinal pigment epithelium (RPE), regulation of channel function by various cytoplasmic metabolites, and mutations that cause channelopathies. At the apical membrane of RPE, K(+) channels contribute to subretinal K(+) homeostasis and support Na(+)/K(+) pump and Na(+)-K(+)-2Cl(-) cotransporter function by providing a pathway for K(+) secretion. Electrophysiological studies have established that barium- and cesium-sensitive inwardly rectifying K(+) (Kir) channels make up a major component of the RPE apical membrane K(+) conductance. Native human RPE expresses transcripts for Kir1.1, Kir2.1, Kir2.2, Kir3.1, Kir3.4, Kir4.2, and Kir6.1, albeit at levels at least 50-fold lower than Kir7.1. Kir7.1 is structurally similar to other Kir channels, consisting of 2 trans-membrane domains, a pore-forming loop that contains the selectivity filter, and 2 cytoplasmic polar tails. Within the cytoplasmic structure, clusters of amino acid sequences form regulatory domains that interact with cellular metabolites and control the opening and closing of the channel. Recent evidence indicated that intrinsic sequence motifs present in Kir7.1 control surface expression. Mutant Kir7.1 channels are associated with inherited eye pathologies such as Snowflake Vitreoretinal Degeneration (SVD) and Lebers Congenital Amaurosis (LCA16). Based on the current evidence, mutations implicated in channelopathies have the potential to be used for genetic testing to diagnose blindness due to Kir7.1.
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Affiliation(s)
- Mohit Kumar
- a Departments of Biotechnology and Bioinformatics ; NIIT University ; Neemrana , Rajasthan , India
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Meehan TL, Kleinsorge SE, Timmons AK, Taylor JD, McCall K. Polarization of the epithelial layer and apical localization of integrins are required for engulfment of apoptotic cells in the Drosophila ovary. Dis Model Mech 2015; 8:1603-14. [PMID: 26398951 PMCID: PMC4728319 DOI: 10.1242/dmm.021998] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/14/2015] [Indexed: 12/28/2022] Open
Abstract
Inefficient clearance of dead cells or debris by epithelial cells can lead to or exacerbate debilitating conditions such as retinitis pigmentosa, macular degeneration, chronic obstructive pulmonary disease and asthma. Despite the importance of engulfment by epithelial cells, little is known about the molecular changes that are required within these cells. The misregulation of integrins has previously been associated with disease states, suggesting that a better understanding of the regulation of receptor trafficking could be key to treating diseases caused by defects in phagocytosis. Here, we demonstrate that the integrin heterodimer αPS3/βPS becomes apically enriched and is required for engulfment by the epithelial follicle cells of the Drosophila ovary. We found that integrin heterodimer localization and function is largely directed by the α-subunit. Moreover, proper cell polarity promotes asymmetric integrin enrichment, suggesting that αPS3/βPS trafficking occurs in a polarized fashion. We show that several genes previously known for their roles in trafficking and cell migration are also required for engulfment. Moreover, as in mammals, the same α-integrin subunit is required by professional and non-professional phagocytes and migrating cells in Drosophila. Our findings suggest that migrating and engulfing cells use common machinery, and demonstrate a crucial role for integrin function and polarized trafficking of integrin subunits during engulfment. This study also establishes the epithelial follicle cells of the Drosophila ovary as a powerful model for understanding the molecular changes required for engulfment by a polarized epithelium. Summary: Apical integrin localization, mediated by polarized and directed trafficking, is crucial for proper engulfment by epithelial cells.
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Affiliation(s)
- Tracy L Meehan
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Sarah E Kleinsorge
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Allison K Timmons
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Jeffrey D Taylor
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Kimberly McCall
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
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Xia CH, Liu H, Cheung D, Tang F, Chang B, Li M, Gong X. NHE8 is essential for RPE cell polarity and photoreceptor survival. Sci Rep 2015; 5:9358. [PMID: 25791178 PMCID: PMC4366848 DOI: 10.1038/srep09358] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/02/2015] [Indexed: 11/09/2022] Open
Abstract
A new N-ethyl-N-nitrosourea (ENU)-induced mouse recessive mutation, identified by fundus examination of the eye, develops depigmented patches, indicating retinal disorder. Histology data show aberrant retinal pigment epithelium (RPE) and late-onset photoreceptor cell loss in the mutant retina. Chromosomal mapping and DNA sequencing reveal a point mutation (T to A) of the Slc9a8 gene, resulting in mutant sodium/proton exchanger 8 (NHE8)-M120K protein. The lysine substitution decreases the probability of forming the 3(rd) transmembrane helix, which impairs the pore structure of the Na(+)/H(+) exchanger. Various RPE defects, including mislocalization of the apical marker ezrin, and disrupted apical microvilli and basal infoldings are observed in mutant mice. We have further generated NHE8 knockout mice and confirmed similar phenotypes, including abnormal RPE cells and late-onset photoreceptor cell loss. Both in vivo and in vitro data indicate that NHE8 co-localizes with ER, Golgi and intracellular vesicles in RPE cells. Thus, NHE8 function is necessary for the survival of photoreceptor cells and NHE8 is important for RPE cell polarity and function. Dysfunctional RPE may ultimately lead to photoreceptor cell death in the NHE8 mutants. Further studies will be needed to elucidate whether or not NHE8 regulates pH homeostasis in the protein secretory pathways of RPE.
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Affiliation(s)
- Chun-hong Xia
- School of Optometry and Vision Science Program, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Haiquan Liu
- School of Optometry and Vision Science Program, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Debra Cheung
- School of Optometry and Vision Science Program, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Felicia Tang
- School of Optometry and Vision Science Program, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Mei Li
- School of Optometry and Vision Science Program, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Xiaohua Gong
- School of Optometry and Vision Science Program, University of California, Berkeley, Berkeley, CA 94720, USA
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Reichhart N, Keckeis S, Fried F, Fels G, Strauss O. Regulation of surface expression of TRPV2 channels in the retinal pigment epithelium. Graefes Arch Clin Exp Ophthalmol 2015; 253:865-74. [DOI: 10.1007/s00417-014-2917-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/23/2014] [Accepted: 12/23/2014] [Indexed: 12/31/2022] Open
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El-Beltagy AEFBM. Light and electron microscopic studies on the pigmented epithelium and photoreceptors of the retina of common buzzard (Buteo buteo). Tissue Cell 2014; 47:78-85. [PMID: 25541273 DOI: 10.1016/j.tice.2014.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 11/20/2014] [Accepted: 11/28/2014] [Indexed: 11/29/2022]
Abstract
The current study is essentially carried out to reveal the histological and ultra-structural details of the retinal pigmented epithelium (RPE) and photoreceptors cell layers of a common buzzard (Buteo buteo). The recorded results revealed that the neural retina of common buzzard consisted of seven distinct cell layers. The inner nuclear layer was markedly revealed as the thickest one among these layers. A highly melanized RPE was recorded in between the choroid and neural retina. Histologically, the RPE was represented by a single layer of cuboidal epithelial cells with centrally located nucleus. Ultrastructurally, the RPE cells showed numerous melanosomes, mitochondria, phagosomes, myeloid bodies, smooth endoplasmic reticulum (SER), but very rare rough endoplasmic reticulum (RER). The photoreceptor cell layer was represented by three categories of photoreceptor cells: few single rods, numerous single and double cones. Each double cone consisted of a short accessory cone and a long principle cone. The photoreceptor outer segment consisted of bi-membranous discs that are enclosed by outer membrane. Moreover, the inner segment of rods consisted of an ellipsoid and an inner hyperboloid. The hyperboloid was rich with RER, polysomes, Golgi apparatus and autophagic vacuoles. Furthermore, the inner segment of single cone and accessory cone consisted of an ellipsoid, paraboloid and myoid regions, while, the inner segment of principle cone lacked the paraboloid regions. At the proximal end of each inner segment for all types of cones, there was a large heterogeneous oil droplet. The paraboloid region was markedly rich with glycogen granules. The myoid region exhibited the same organelles but with little glycogen granules when compared with hyperboloid.
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Hsiung J, Zhu D, Hinton DR. Polarized human embryonic stem cell-derived retinal pigment epithelial cell monolayers have higher resistance to oxidative stress-induced cell death than nonpolarized cultures. Stem Cells Transl Med 2014; 4:10-20. [PMID: 25411476 DOI: 10.5966/sctm.2014-0205] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Oxidative stress-mediated injury to the retinal pigment epithelium (RPE) is a major factor involved in the pathogenesis of age-related macular degeneration (AMD), the leading cause of blindness in the elderly. Human embryonic stem cell (hESC)-derived RPE cells are currently being evaluated for their potential for cell therapy in AMD patients through subretinal injection of cells in suspension and subretinal placement as a polarized monolayer. To gain an understanding of how transplanted RPE cells will respond to the highly oxidatively stressed environment of an AMD patient eye, we compared the survival of polarized and nonpolarized RPE cultures following oxidative stress treatment. Polarized, nonpolarized/confluent, nonpolarized/subconfluent hESC-RPE cells were treated with H2O2. Terminal deoxynucleotidyl transferase dUTP nick end labeling stains revealed the highest amount of cell death in subconfluent hESC-RPE cells and little cell death in polarized hESC-RPE cells with H2O2 treatment. There were higher levels of proapoptotic factors (phosphorylated p38, phosphorylated c-Jun NH2-terminal kinase, Bax, and cleaved caspase 3 fragments) in treated nonpolarized RPE-particularly subconfluent cells-relative to polarized cells. On the other hand, polarized RPE cells had constitutively higher levels of cell survival and antiapoptotic signaling factors such as p-Akt and Bcl-2, as well as antioxidants superoxide dismutase 1 and catalase relative to nonpolarized cells, that possibly contributed to polarized cells' higher tolerance to oxidative stress compared with nonpolarized RPE cells. Subconfluent cells were particularly sensitive to oxidative stress-induced apoptosis. These results suggest that implantation of polarized hESC-RPE monolayers for treating AMD patients with geographic atrophy should have better survival than injections of hESC-RPE cells in suspension.
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Affiliation(s)
- Jamie Hsiung
- Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - Danhong Zhu
- Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
| | - David R Hinton
- Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA
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Farkas MH, Lew DS, Sousa ME, Bujakowska K, Chatagnon J, Bhattacharya SS, Pierce EA, Nandrot EF. Mutations in pre-mRNA processing factors 3, 8, and 31 cause dysfunction of the retinal pigment epithelium. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2641-52. [PMID: 25111227 PMCID: PMC4188860 DOI: 10.1016/j.ajpath.2014.06.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 06/11/2014] [Accepted: 06/13/2014] [Indexed: 10/24/2022]
Abstract
Mutations in the ubiquitously expressed pre-mRNA processing factors 3, 8, and 31 (PRPF3, PRPF8, and PRPF31) cause nonsyndromic dominant retinitis pigmentosa in humans, an inherited retinal degeneration. It is unclear what mechanisms, or which cell types of the retina, are affected. Transgenic mice with the human mutations in these genes display late-onset morphological changes in the retinal pigment epithelium (RPE). To determine whether the observed morphological changes are preceded by abnormal RPE function, we investigated its phagocytic function in Prpf3(T494M/T494M), Prpf8(H2309P/H2309P), and Prpf31(+/-) mice. We observe decreased phagocytosis in primary RPE cultures from mutant mice, and this is replicated by shRNA-mediated knockdown of PRPF31 in human ARPE-19 cells. The diurnal rhythmicity of phagocytosis is almost lost, indicated by the marked attenuation of the phagocytic burst 2 hours after light onset. The strength of adhesion between RPE apical microvilli and photoreceptor outer segments also declined during peak adhesion in all mutants. In all models, at least one of the receptors involved in binding and internalization of shed photoreceptor outer segments was subjected to changes in localization. Although the mechanism underlying these changes in RPE function is yet to be elucidated, these data are consistent with the mouse RPE being the primary cell affected by mutations in the RNA splicing factors, and these changes occur at an early age.
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Affiliation(s)
- Michael H Farkas
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
| | - Deborah S Lew
- Vision Institute, INSERM, U968, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, CNRS, UMR_7210, Paris, France
| | - Maria E Sousa
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
| | - Kinga Bujakowska
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts; Vision Institute, INSERM, U968, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, CNRS, UMR_7210, Paris, France
| | - Jonathan Chatagnon
- Vision Institute, INSERM, U968, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, CNRS, UMR_7210, Paris, France
| | - Shomi S Bhattacharya
- Vision Institute, INSERM, U968, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, CNRS, UMR_7210, Paris, France; Institute of Ophthalmology, University College London, London, United Kingdom; Andalusian Center of Molecular Biology and Regenerative Medicine, Andalusian Center for Molecular Biology and Regenerative Medicine (CABIMER), Sevilla, Spain
| | - Eric A Pierce
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts.
| | - Emeline F Nandrot
- Vision Institute, INSERM, U968, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, CNRS, UMR_7210, Paris, France.
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45
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Ion channels and transporters of the retinal pigment epithelium. Exp Eye Res 2014; 126:27-37. [DOI: 10.1016/j.exer.2014.05.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 12/19/2022]
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Willermain F, Libert S, Motulsky E, Salik D, Caspers L, Perret J, Delporte C. Origins and consequences of hyperosmolar stress in retinal pigmented epithelial cells. Front Physiol 2014; 5:199. [PMID: 24910616 PMCID: PMC4038854 DOI: 10.3389/fphys.2014.00199] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/09/2014] [Indexed: 01/21/2023] Open
Abstract
The retinal pigmented epithelium (RPE) is composed of retinal pigmented epithelial cells joined by tight junctions and represents the outer blood-retinal barrier (BRB). The inner BRB is made of endothelial cells joined by tight junctions and glial extensions surrounding all the retinal blood vessels. One of the functions of the RPE is to maintain an osmotic transepithelial gradient created by ionic pumps and channels, avoiding paracellular flux. Under such physiological conditions, transcellular water movement follows the osmotic gradient and flows normally from the retina to the choroid through the RPE. Several diseases, such as diabetic retinopathy, are characterized by the BRB breakdown leading to leakage of solutes, proteins, and fluid from the retina and the choroid. The prevailing hypothesis explaining macular edema formation during diabetic retinopathy incriminates the inner BRB breakdown resulting in increased osmotic pressure leading in turn to massive water accumulation that can affect vision. Under these conditions, it has been hypothesized that RPE is likely to be exposed to hyperosmolar stress at its apical side. This review summarizes the origins and consequences of osmotic stress in the RPE. Ongoing and further research advances will clarify the mechanisms, at the molecular level, involved in the response of the RPE to osmotic stress and delineate potential novel therapeutic targets and tools.
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Affiliation(s)
- François Willermain
- Department of Ophthalmology, CHU Saint-Pierre and Brugmann Brussels, Belgium ; I.R.I.B.H.M, Université Libre de Bruxelles Brussels, Belgium
| | - Sarah Libert
- Department of Ophthalmology, CHU Saint-Pierre and Brugmann Brussels, Belgium ; Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Université Libre de Bruxelles Brussels, Belgium
| | - Elie Motulsky
- Department of Ophthalmology, CHU Saint-Pierre and Brugmann Brussels, Belgium ; Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Université Libre de Bruxelles Brussels, Belgium
| | - Dany Salik
- Department of Ophthalmology, CHU Saint-Pierre and Brugmann Brussels, Belgium ; Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Université Libre de Bruxelles Brussels, Belgium
| | - Laure Caspers
- Department of Ophthalmology, CHU Saint-Pierre and Brugmann Brussels, Belgium
| | - Jason Perret
- Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Université Libre de Bruxelles Brussels, Belgium
| | - Christine Delporte
- Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Université Libre de Bruxelles Brussels, Belgium
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47
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Johnson AA, Lee YS, Stanton JB, Yu K, Hartzell CH, Marmorstein LY, Marmorstein AD. Differential effects of Best disease causing missense mutations on bestrophin-1 trafficking. Hum Mol Genet 2013; 22:4688-97. [PMID: 23825107 DOI: 10.1093/hmg/ddt316] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in bestrophin-1 (Best1) cause Best vitelliform macular dystrophy (BVMD), a dominantly inherited retinal degenerative disease. Best1 is a homo-oligomeric anion channel localized to the basolateral surface of retinal pigment epithelial (RPE) cells. A number of Best1 mutants mislocalize in Madin-Darby canine kidney (MDCK) cells. However, many proteins traffic differently in MDCK and RPE cells, and MDCK cells do not express endogenous Best1. Thus, effects of Best1 mutations on localization in MDCK cells may not translate to RPE cells. To determine whether BVMD causing mutations affect Best1 localization, we compared localization and oligomerization of Best1 with Best1 mutants V9M, W93C, and R218C. In MDCK cells, Best1 and Best1(R218C) were basolaterally localized. Best1(W93C) and Best1(V9M) accumulated in cells. In cultured fetal human retinal pigment epithelium cells (fhRPE) expressing endogenous Best1, Best1(R218C) and Best1(W93C) were basolateral. Best1(V9M) was intracellular. All three mutants exhibited similar fluorescence resonance energy transfer (FRET) efficiencies to, and co-immunoprecipitated with Best1, indicating unimpaired oligomerization. When human Best1 was expressed in RPE in mouse eyes it was basolaterally localized. However, Best1(V9M) accumulated in intracellular compartments in mouse RPE. Co-expression of Best1 and Best1(W93C) in MDCK cells resulted in basolateral localization of both Best1 and Best1(W93C), but co-expression of Best1 with Best1(V9M) resulted in mislocalization of both proteins. We conclude that different mutations in Best1 cause differential effects on its localization and that this effect varies with the presence or absence of wild-type (WT) Best1. Furthermore, MDCK cells can substitute for RPE when examining the effects of BVMD causing mutations on Best1 localization if co-expressed with WT Best1.
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48
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Mony S, Lee SJ, Harper JF, Barwe SP, Langhans SA. Regulation of Na,K-ATPase β1-subunit in TGF-β2-mediated epithelial-to-mesenchymal transition in human retinal pigmented epithelial cells. Exp Eye Res 2013; 115:113-22. [PMID: 23810808 DOI: 10.1016/j.exer.2013.06.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 04/15/2013] [Accepted: 06/07/2013] [Indexed: 12/14/2022]
Abstract
Proliferative vitreo retinopathy (PVR) is associated with extracellular matrix membrane (ECM) formation on the neural retina and disruption of the multilayered retinal architecture leading to distorted vision and blindness. During disease progression in PVR, retinal pigmented epithelial cells (RPE) lose cell-cell adhesion, undergo epithelial-to-mesenchymal transition (EMT), and deposit ECM leading to tissue fibrosis. The EMT process is mediated via exposure to vitreous cytokines and growth factors such as TGF-β2. Previous studies have shown that Na,K-ATPase is required for maintaining a normal polarized epithelial phenotype and that decreased Na,K-ATPase function and subunit levels are associated with TGF-β1-mediated EMT in kidney cells. In contrast to the basolateral localization of Na,K-ATPase in most epithelia, including kidney, Na,K-ATPase is found on the apical membrane in RPE cells. We now show that EMT is also associated with altered Na,K-ATPase expression in RPE cells. TGF-β2 treatment of ARPE-19 cells resulted in a time-dependent decrease in Na,K-ATPase β1 mRNA and protein levels while Na,K-ATPase α1 levels, Na,K-ATPase activity, and intracellular sodium levels remained largely unchanged. In TGF-β2-treated cells reduced Na,K-ATPase β1 mRNA inversely correlated with HIF-1α levels and analysis of the Na,K-ATPase β1 promoter revealed a putative hypoxia response element (HRE). HIF-1α bound to the Na,K-ATPase β1 promoter and inhibiting the activity of HIF-1α blocked the TGF-β2 mediated Na,K-ATPase β1 decrease suggesting that HIF-1α plays a potential role in Na,K-ATPase β1 regulation during EMT in RPE cells. Furthermore, knockdown of Na,K-ATPase β1 in ARPE-19 cells was associated with a change in cell morphology from epithelial to mesenchymal and induction of EMT markers such as α-smooth muscle actin and fibronectin, suggesting that loss of Na,K-ATPase β1 is a potential contributor to TGF-β2-mediated EMT in RPE cells.
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Affiliation(s)
- Sridevi Mony
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Rockland Center I, 1701 Rockland Road, Wilmington, DE 19803, USA.
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49
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Pan CK, Heilweil G, Lanza R, Schwartz SD. Embryonic stem cells as a treatment for macular degeneration. Expert Opin Biol Ther 2013; 13:1125-33. [DOI: 10.1517/14712598.2013.793304] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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50
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Parker MD, Boron WF. The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters. Physiol Rev 2013; 93:803-959. [PMID: 23589833 PMCID: PMC3768104 DOI: 10.1152/physrev.00023.2012] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mammalian Slc4 (Solute carrier 4) family of transporters is a functionally diverse group of 10 multi-spanning membrane proteins that includes three Cl-HCO3 exchangers (AE1-3), five Na(+)-coupled HCO3(-) transporters (NCBTs), and two other unusual members (AE4, BTR1). In this review, we mainly focus on the five mammalian NCBTs-NBCe1, NBCe2, NBCn1, NDCBE, and NBCn2. Each plays a specialized role in maintaining intracellular pH and, by contributing to the movement of HCO3(-) across epithelia, in maintaining whole-body pH and otherwise contributing to epithelial transport. Disruptions involving NCBT genes are linked to blindness, deafness, proximal renal tubular acidosis, mental retardation, and epilepsy. We also review AE1-3, AE4, and BTR1, addressing their relevance to the study of NCBTs. This review draws together recent advances in our understanding of the phylogenetic origins and physiological relevance of NCBTs and their progenitors. Underlying these advances is progress in such diverse disciplines as physiology, molecular biology, genetics, immunocytochemistry, proteomics, and structural biology. This review highlights the key similarities and differences between individual NCBTs and the genes that encode them and also clarifies the sometimes confusing NCBT nomenclature.
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Affiliation(s)
- Mark D Parker
- Dept. of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA.
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