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Reddien PW. The purpose and ubiquity of turnover. Cell 2024; 187:2657-2681. [PMID: 38788689 DOI: 10.1016/j.cell.2024.04.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/19/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024]
Abstract
Turnover-constant component production and destruction-is ubiquitous in biology. Turnover occurs across organisms and scales, including for RNAs, proteins, membranes, macromolecular structures, organelles, cells, hair, feathers, nails, antlers, and teeth. For many systems, turnover might seem wasteful when degraded components are often fully functional. Some components turn over with shockingly high rates and others do not turn over at all, further making this process enigmatic. However, turnover can address fundamental problems by yielding powerful properties, including regeneration, rapid repair onset, clearance of unpredictable damage and errors, maintenance of low constitutive levels of disrepair, prevention of stable hazards, and transitions. I argue that trade-offs between turnover benefits and metabolic costs, combined with constraints on turnover, determine its presence and rates across distinct contexts. I suggest that the limits of turnover help explain aging and that turnover properties and the basis for its levels underlie this fundamental component of life.
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Affiliation(s)
- Peter W Reddien
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, MIT, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, MIT, Cambridge, MA 02139, USA.
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2
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Williams RC, Harrison WW, Carkeet A, Ostrin LA. Twenty-four hour diurnal variation in retinal oxygen saturation. Vision Res 2023; 213:108314. [PMID: 37657366 PMCID: PMC11148934 DOI: 10.1016/j.visres.2023.108314] [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: 05/20/2023] [Revised: 07/12/2023] [Accepted: 08/16/2023] [Indexed: 09/03/2023]
Abstract
Retinal oxygen saturation is influenced by systemic and local vasculature, intraocular pressure (IOP), and individual cellular function. In numerous retinal pathologies, early changes take place at the level of the microvasculature, thereby affecting retinal oxygenation. The purpose of this study was to investigate diurnal variations in retinal oximetry measures and evaluate the relationship with other ocular and systemic physiological processes. Healthy adults (n = 18, mean age 27 ± 5.5 years) participated. Ocular and systemic measures were collected every four hours over 24 h and included retinal oximetry, IOP, optical coherence tomography (OCT), OCT-angiography (OCTA), biometry, blood pressure, and partial pressure of oxygen. Amplitude and acrophase for retinal oxygen saturation, axial length, retinal and choroidal thickness, OCTA parameters, and mean arterial and ocular perfusion pressure (MAP, MOPP) were determined were determined using cosine fits, and multiple regression analysis was performed to compare metrics. Retinal oxygenation saturation demonstrated a significant diurnal variation with an amplitude of 5.84 ± 3.86% and acrophase of 2.35 h. Other parameters that demonstrated significant diurnal variation included IOP, MOPP, axial length, choroidal thickness, superficial vessel density, heart rate, systolic blood pressure, and MAP. Diurnal variations in retinal oxygen saturation were in-phase with choroidal thickness, IOP, and density of the superficial vascular plexus and out-of-phase with axial length and MOPP. In conclusion, retinal oxygenation saturation undergoes diurnal variations over 24 h. These findings contribute to a better understanding of intrinsic and extrinsic factors influencing oxygenation of the area surrounding the fovea.
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Affiliation(s)
- Rachel C Williams
- University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX 77204, United States
| | - Wendy W Harrison
- University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX 77204, United States
| | - Andrew Carkeet
- Queensland University of Technology, School of Optometry and Vision Science QUT, Kelvin Grove, Qld 4059, Australia
| | - Lisa A Ostrin
- University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX 77204, United States.
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3
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Burstyn-Cohen T, Fresia R. TAM receptors in phagocytosis: Beyond the mere internalization of particles. Immunol Rev 2023; 319:7-26. [PMID: 37596991 DOI: 10.1111/imr.13267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/18/2023] [Indexed: 08/21/2023]
Abstract
TYRO3, AXL, and MERTK constitute the TAM family of receptor tyrosine kinases, activated by their ligands GAS6 and PROS1. TAMs are necessary for adult homeostasis in the immune, nervous, reproductive, skeletal, and vascular systems. Among additional cellular functions employed by TAMs, phagocytosis is central for tissue health. TAM receptors are dominant in providing phagocytes with the molecular machinery necessary to engulf diverse targets, including apoptotic cells, myelin debris, and portions of live cells in a phosphatidylserine-dependent manner. Simultaneously, TAMs drive the release of anti-inflammatory and tissue repair molecules. Disruption of the TAM-driven phagocytic pathway has detrimental consequences, resulting in autoimmunity, male infertility, blindness, and disrupted vascular integrity, and which is thought to contribute to neurodegenerative diseases. Although structurally and functionally redundant, the TAM receptors and ligands underlie complex signaling cascades, of which several key aspects are yet to be elucidated. We discuss similarities and differences between TAMs and other phagocytic pathways, highlight future directions and how TAMs can be harnessed therapeutically to modulate phagocytosis.
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Affiliation(s)
- Tal Burstyn-Cohen
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Roberta Fresia
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
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4
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Markitantova YV, Grigoryan EN. Cellular and Molecular Triggers of Retinal Regeneration in Amphibians. Life (Basel) 2023; 13:1981. [PMID: 37895363 PMCID: PMC10608152 DOI: 10.3390/life13101981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/23/2023] [Accepted: 09/26/2023] [Indexed: 10/29/2023] Open
Abstract
Understanding the mechanisms triggering the initiation of retinal regeneration in amphibians may advance the quest for prevention and treatment options for degenerating human retina diseases. Natural retinal regeneration in amphibians requires two cell sources, namely retinal pigment epithelium (RPE) and ciliary marginal zone. The disruption of RPE interaction with photoreceptors through surgery or injury triggers local and systemic responses for retinal protection. In mammals, disease-induced damage to the retina results in the shutdown of the function, cellular or oxidative stress, pronounced immune response, cell death and retinal degeneration. In contrast to retinal pathology in mammals, regenerative responses in amphibians have taxon-specific features ensuring efficient regeneration. These include rapid hemostasis, the recruitment of cells and factors of endogenous defense systems, activities of the immature immune system, high cell viability, and the efficiency of the extracellular matrix, cytoskeleton, and cell surface remodeling. These reactions are controlled by specific signaling pathways, transcription factors, and the epigenome, which are insufficiently studied. This review provides a summary of the mechanisms initiating retinal regeneration in amphibians and reveals its features collectively directed at recruiting universal responses to trauma to activate the cell sources of retinal regeneration. This study of the integrated molecular network of these processes is a prospect for future research in demand biomedicine.
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Affiliation(s)
| | - Eleonora N. Grigoryan
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia;
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5
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Brunner SM, Schrödl F, Preishuber-Pflügl J, Runge C, Koller A, Lenzhofer M, Reitsamer HA, Trost A. Distribution of the cysteinyl leukotriene system components in the human, rat and mouse eye. Exp Eye Res 2023; 232:109517. [PMID: 37211287 DOI: 10.1016/j.exer.2023.109517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/18/2023] [Indexed: 05/23/2023]
Abstract
The cysteinyl leukotrienes (CysLTs) have important functions in the regulation of inflammation and cellular stress. Blocking the CysLT receptors (CysLTRs) with specific antagonists is beneficial against progression of retinopathies (e.g. diabetic retinopathy, wet AMD). However, the exact cellular localization of the CysLTRs and their endogenous ligands in the eye have not been elucidated in detail yet. It is also not known whether the expression patterns differ between humans and animal models. Therefore, the present study aimed to describe and compare the distribution of two important enzymes in CysLT biosynthesis, 5-lipoxygenase (5-LOX) and 5-lipoxygenase-activating protein (FLAP), and of CysLTR1 and CysLTR2 in healthy human, rat and mouse eyes. Human donor eyes (n = 10) and eyes from adult Sprague Dawley rats (n = 5) and CD1 mice (n = 8) of both sexes were collected. The eyes were fixed in 4% paraformaldehyde and cross-sections were investigated by immunofluorescence with specific antibodies against 5-LOX, FLAP (human tissue only), CysLTR1 and CysLTR2. Flat-mounts of the human choroid were prepared and processed similarly. Expression patterns were assessed and semiquantitatively evaluated using a confocal fluorescence microscope (LSM710, Zeiss). We observed so far unreported expression sites for CysLT system components in various ocular tissues. Overall, we detected expression of 5-LOX, CysLTR1 and CysLTR2 in the human, rat and mouse cornea, conjunctiva, iris, lens, ciliary body, retina and choroid. Importantly, expression profiles of CysLTR1 and CysLTR2 were highly similar between human and rodent eyes. FLAP was expressed in all human ocular tissues except the lens. Largely weak immunoreactivity of FLAP and 5-LOX was observed in a few, yet unidentified, cells of diverse ocular tissues, indicating low levels of CysLT biosynthesis in healthy eyes. CysLTR1 was predominantly detected in ocular epithelial cells, supporting the involvement of CysLTR1 in stress and immune responses. CysLTR2 was predominantly expressed in neuronal structures, suggesting neuromodulatory roles of CysLTR2 in the eye and revealing disparate functions of CysLTRs in ocular tissues. Taken together, we provide a comprehensive protein expression atlas of CysLT system components in the human and rodent eye. While the current study is purely descriptive and therefore does not allow significant functional conclusions yet, it represents an important basis for future studies in diseased ocular tissues in which distribution patterns or expression levels of the CysLT system might be altered. Furthermore, this is the first comprehensive study to elucidate expression patterns of CysLT system components in human and animal models that will help to identify and understand functions of the system as well as mechanisms of action of potential CysLTR ligands in the eye.
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Affiliation(s)
- Susanne M Brunner
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Falk Schrödl
- Center for Anatomy and Cell Biology, Institute of Anatomy and Cell Biology, Paracelsus Medical University, Strubergasse 21, 5020 Salzburg, Austria.
| | - Julia Preishuber-Pflügl
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Christian Runge
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria; Cornea Eye Bank, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Andreas Koller
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Markus Lenzhofer
- Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Herbert A Reitsamer
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria; Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
| | - Andrea Trost
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Muellner Hauptstr. 48, 5020 Salzburg, Austria.
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6
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Bhoi JD, Goel M, Ribelayga CP, Mangel SC. Circadian clock organization in the retina: From clock components to rod and cone pathways and visual function. Prog Retin Eye Res 2023; 94:101119. [PMID: 36503722 PMCID: PMC10164718 DOI: 10.1016/j.preteyeres.2022.101119] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 12/13/2022]
Abstract
Circadian (24-h) clocks are cell-autonomous biological oscillators that orchestrate many aspects of our physiology on a daily basis. Numerous circadian rhythms in mammalian and non-mammalian retinas have been observed and the presence of an endogenous circadian clock has been demonstrated. However, how the clock and associated rhythms assemble into pathways that support and control retina function remains largely unknown. Our goal here is to review the current status of our knowledge and evaluate recent advances. We describe many previously-observed retinal rhythms, including circadian rhythms of morphology, biochemistry, physiology, and gene expression. We evaluate evidence concerning the location and molecular machinery of the retinal circadian clock, as well as consider findings that suggest the presence of multiple clocks. Our primary focus though is to describe in depth circadian rhythms in the light responses of retinal neurons with an emphasis on clock control of rod and cone pathways. We examine evidence that specific biochemical mechanisms produce these daily light response changes. We also discuss evidence for the presence of multiple circadian retinal pathways involving rhythms in neurotransmitter activity, transmitter receptors, metabolism, and pH. We focus on distinct actions of two dopamine receptor systems in the outer retina, a dopamine D4 receptor system that mediates circadian control of rod/cone gap junction coupling and a dopamine D1 receptor system that mediates non-circadian, light/dark adaptive regulation of gap junction coupling between horizontal cells. Finally, we evaluate the role of circadian rhythmicity in retinal degeneration and suggest future directions for the field of retinal circadian biology.
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Affiliation(s)
- Jacob D Bhoi
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA; Neuroscience Honors Research Program, William Marsh Rice University, Houston, TX, USA
| | - Manvi Goel
- Department of Neuroscience, Wexner Medical Center, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Christophe P Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, UTHEALTH-The University of Texas Health Science Center at Houston, Houston, TX, USA; Neuroscience Honors Research Program, William Marsh Rice University, Houston, TX, USA.
| | - Stuart C Mangel
- Department of Neuroscience, Wexner Medical Center, College of Medicine, The Ohio State University, Columbus, OH, USA.
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7
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Faure C, Chassery M, Ores R, Audo I. Didanosine-induced Retinopathy: New Insights with Long-term Follow-up. Ocul Immunol Inflamm 2022; 30:1625-1632. [PMID: 34255599 DOI: 10.1080/09273948.2021.1927117] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Didanosine is an adenosine analog, part of the nucleoside reverse-transcriptase inhibitor family. Since the description of didanosine-induced retinopathy in the early 1990s, little is known about the progression of this toxic retinopathy and the putative underlying mitochondrial defect. OBJECTIVES We report long-term follow-up for cases of didanosine-induced retinopathy and discuss a new hypothesis for pathophysiology based on the alteration of endogenous adenosine on the photoreceptor outer segment turnover and phagocytosis by the retinal pigment epithelium. METHODS Ophthalmic data from six cases (12 eyes) of didanosine-induced retinopathy from a single institution were retrospectively analyzed. RESULTS All patients displayed bilateral retinal alterations in the mid-periphery. Despite didanosine discontinuation, patients with advanced areas of patchy chorioretinal atrophy appeared to have a faster progression than those with limited lesions. Full-field electroretinogram revealed generalized rod-cone dysfunction in most cases that remained stable over time. CONCLUSION We propose new guidelines including early screening and long-term observations.
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Affiliation(s)
- Céline Faure
- Unité d'électrophysiologie, Centre Hospitalier National des Quinze-Vingts, Paris, France.,Hôpital Privé Saint Martin, Département d'ophtalmologie, Ramsay Générale de Santé, Caen, France
| | - Maxime Chassery
- Unité d'électrophysiologie, Centre Hospitalier National des Quinze-Vingts, Paris, France
| | - Raphaëlle Ores
- Unité d'électrophysiologie, Centre Hospitalier National des Quinze-Vingts, Paris, France
| | - Isabelle Audo
- Unité d'électrophysiologie, Centre Hospitalier National des Quinze-Vingts, Paris, France.,INSERM-DHOS CIC1423, CHNO des Quinze-Vingts, DHU Sight Restore, Paris, France.,Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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8
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Gullapalli VK, Zarbin MA. New Prospects for Retinal Pigment Epithelium Transplantation. Asia Pac J Ophthalmol (Phila) 2022; 11:302-313. [PMID: 36041145 DOI: 10.1097/apo.0000000000000521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/28/2022] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT Retinal pigment epithelium (RPE) transplants rescue photoreceptors in selected animal models of retinal degenerative disease. Early clinical studies of RPE transplants as treatment for age-related macular degeneration (AMD) included autologous and allogeneic transplants of RPE suspensions and RPE sheets for atrophic and neovascular complications of AMD. Subsequent studies explored autologous RPE-Bruch membrane-choroid transplants in patients with neovascular AMD with occasional marked visual benefit, which establishes a rationale for RPE transplants in late-stage AMD. More recent work has involved transplantation of autologous and allogeneic stem cell-derived RPE for patients with AMD and those with Stargardt disease. These early-stage clinical trials have employed RPE suspensions and RPE monolayers on biocompatible scaffolds. Safety has been well documented, but evidence of efficacy is variable. Current research involves development of better scaffolds, improved modulation of immune surveillance, and modification of the extracellular milieu to improve RPE survival and integration with host retina.
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Affiliation(s)
| | - Marco A Zarbin
- Iinstitute of Ophthalmology and visual Science, Rutgers-New Jersey Medical School, Rutgers University, Newark, NJ, US
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Kim J, Won JY. Effect of Photobiomodulation in Suppression of Oxidative Stress on Retinal Pigment Epithelium. Int J Mol Sci 2022; 23:ijms23126413. [PMID: 35742861 PMCID: PMC9224180 DOI: 10.3390/ijms23126413] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/04/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
As the world undergoes aging, the number of age-related diseases has increased. One of them is disease related to retinal pigment epithelium (RPE) degeneration, such as age-related macular degeneration, causing vision loss without physical damage in the ocular system. It is the leading cause of blindness, with no cure. Although the exact pathogenesis is still unknown, the research shows that oxidative stress is one of the risk factors. Various molecules have been reported as anti-oxidative materials; however, the disease has not yet been conquered. Here, we would like to introduce photobiomodulation (PBM). PBM is a non-invasive treatment based on red and near-infrared light and has been used to cure various diseases by regulating cellular functions. Furthermore, recent studies showed its antioxidant effect, and due to this reason, PBM is arising as a new treatment for ocular disease. In this study, we confirm the antioxidant effect of PBM in retinal pigment epithelium via an RPE model with hypoxia. The function of RPE is protected by PBM against damage from hypoxia. Furthermore, we observed the protective mechanism of PBM by its suppression effect on reactive oxygen species generation. These results indicate that PBM shows great potential to cure RPE degeneration to help patients with blindness.
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Affiliation(s)
- Jongmin Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea;
| | - Jae Yon Won
- Department of Ophthalmology and Visual Science, Eunpyeong St. Mary’s Hospital, The Catholic University of Korea, Seoul 03312, Korea
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul 14662, Korea
- Correspondence:
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10
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Hsieh CL, Yao Y, Gurevich VV, Chen J. Arrestin Facilitates Rhodopsin Dephosphorylation in Vivo. J Neurosci 2022; 42:3537-3545. [PMID: 35332081 PMCID: PMC9053844 DOI: 10.1523/jneurosci.0141-22.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/08/2022] [Accepted: 03/17/2022] [Indexed: 01/14/2023] Open
Abstract
Deactivation of G-protein-coupled receptors (GPCRs) involves multiple phosphorylations followed by arrestin binding, which uncouples the GPCR from G-protein activation. Some GPCRs, such as rhodopsin, are reused many times. Arrestin dissociation and GPCR dephosphorylation are key steps in the recycling process. In vitro evidence suggests that visual arrestin (ARR1) binding to light-activated, phosphorylated rhodopsin hinders dephosphorylation. Whether ARR1 binding also affects rhodopsin dephosphorylation in vivo is not known. We investigated this using both male and female mice lacking ARR1. Mice were exposed to bright light and placed in darkness for different periods of time, and differently phosphorylated species of rhodopsin were assayed by isoelectric focusing. For WT mice, rhodopsin dephosphorylation was nearly complete by 1 h in darkness. Surprisingly, we observed that, in the Arr1 KO rods, rhodopsin remained phosphorylated even after 3 h. Delayed dephosphorylation in Arr1 KO rods cannot be explained by cell stress induced by persistent signaling, since it is not prevented by the removal of transducin, the visual G-protein, nor can it be explained by downregulation of protein phosphatase 2A, the putative rhodopsin phosphatase. We further show that cone arrestin (ARR4), which binds light-activated, phosphorylated rhodopsin poorly, had little effect in enhancing rhodopsin dephosphorylation, whereas mice expressing binding-competent mutant ARR1-3A showed a similar time course of rhodopsin dephosphorylation as WT. Together, these results reveal a novel role of ARR1 in facilitating rhodopsin dephosphorylation in vivoSIGNIFICANCE STATEMENT G-protein-coupled receptors (GPCRs) are transmembrane proteins used by cells to receive and respond to a broad range of extracellular signals that include neurotransmitters, hormones, odorants, and light (photons). GPCR signaling is terminated by two sequential steps: phosphorylation and arrestin binding. Both steps must be reversed when GPCRs are recycled and reused. Dephosphorylation, which is required for recycling, is an understudied process. Using rhodopsin as a prototypical GPCR, we discovered that arrestin facilitated rhodopsin dephosphorylation in living mice.
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Affiliation(s)
- Chia-Ling Hsieh
- Ziliha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Yun Yao
- Ziliha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
| | - Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - Jeannie Chen
- Ziliha Neurogenetic Institute, Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, California 90089
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Shahin S, Xu H, Lu B, Mercado A, Jones MK, Bakondi B, Wang S. AAV-CRISPR/Cas9 Gene Editing Preserves Long-Term Vision in the P23H Rat Model of Autosomal Dominant Retinitis Pigmentosa. Pharmaceutics 2022; 14:pharmaceutics14040824. [PMID: 35456659 PMCID: PMC9026811 DOI: 10.3390/pharmaceutics14040824] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 02/04/2023] Open
Abstract
Retinitis pigmentosa (RP) consists of a group of inherited, retinal degenerative disorders and is characterized by progressive loss of rod photoreceptors and eventual degeneration of cones in advanced stages, resulting in vision loss or blindness. Gene therapy has been effective in treating autosomal recessive RP (arRP). However, limited options are available for patients with autosomal dominant RP (adRP). In vivo gene editing may be a therapeutic option to treat adRP. We previously rescued vision in neonatal adRP rats by the selective ablation of the Rhodopsin S334ter transgene following electroporation of a CRISPR/Cas9 vector. However, the translational feasibility and long-term safety and efficacy of ablation therapy is unclear. To this end, we show that AAV delivery of a CRISPR/Cas9 construct disrupted the Rhodopsin P23H transgene in postnatal rats, which rescued long-term vision and retinal morphology.
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12
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Baba K, Goyal V, Tosini G. Circadian Regulation of Retinal Pigment Epithelium Function. Int J Mol Sci 2022; 23:2699. [PMID: 35269840 PMCID: PMC8910459 DOI: 10.3390/ijms23052699] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 12/22/2022] Open
Abstract
The retinal pigment epithelium (RPE) is a single layer of cells located between the choriocapillaris vessels and the light-sensitive photoreceptors in the outer retina. The RPE performs physiological processes necessary for the maintenance and support of photoreceptors and visual function. Among the many functions performed by the RPE, the timing of the peak in phagocytic activity by the RPE of the photoreceptor outer segments that occurs 1-2 h. after the onset of light has captured the interest of many investigators and has thus been intensively studied. Several studies have shown that this burst in phagocytic activity by the RPE is under circadian control and is present in nocturnal and diurnal species and rod and cone photoreceptors. Previous investigations have demonstrated that a functional circadian clock exists within multiple retinal cell types and RPE cells. However, the anatomical location of the circadian controlling this activity is not clear. Experimental evidence indicates that the circadian clock, melatonin, dopamine, and integrin signaling play a key role in controlling this rhythm. A series of very recent studies report that the circadian clock in the RPE controls the daily peak in phagocytic activity. However, the loss of the burst in phagocytic activity after light onset does not result in photoreceptor or RPE deterioration during aging. In the current review, we summarized the current knowledge on the mechanism controlling this phenomenon and the physiological role of this peak.
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Affiliation(s)
| | | | - Gianluca Tosini
- Department of Pharmacology & Toxicology and Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA; (K.B.); (V.G.)
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13
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Multimodal brain and retinal imaging of dopaminergic degeneration in Parkinson disease. Nat Rev Neurol 2022; 18:203-220. [PMID: 35177849 DOI: 10.1038/s41582-022-00618-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/13/2022] [Indexed: 12/12/2022]
Abstract
Parkinson disease (PD) is a progressive disorder characterized by dopaminergic neurodegeneration in the brain. The development of parkinsonism is preceded by a long prodromal phase, and >50% of dopaminergic neurons can be lost from the substantia nigra by the time of the initial diagnosis. Therefore, validation of in vivo imaging biomarkers for early diagnosis and monitoring of disease progression is essential for future therapeutic developments. PET and single-photon emission CT targeting the presynaptic terminals of dopaminergic neurons can be used for early diagnosis by detecting axonal degeneration in the striatum. However, these techniques poorly differentiate atypical parkinsonian syndromes from PD, and their availability is limited in clinical settings. Advanced MRI in which pathological changes in the substantia nigra are visualized with diffusion, iron-sensitive susceptibility and neuromelanin-sensitive sequences potentially represents a more accessible imaging tool. Although these techniques can visualize the classic degenerative changes in PD, they might be insufficient for phenotyping or prognostication of heterogeneous aspects of PD resulting from extranigral pathologies. The retina is an emerging imaging target owing to its pathological involvement early in PD, which correlates with brain pathology. Retinal optical coherence tomography (OCT) is a non-invasive technique to visualize structural changes in the retina. Progressive parafoveal thinning and fovea avascular zone remodelling, as revealed by OCT, provide potential biomarkers for early diagnosis and prognostication in PD. As we discuss in this Review, multimodal imaging of the substantia nigra and retina is a promising tool to aid diagnosis and management of PD.
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Huang S, Liu CH, Wang Z, Fu Z, Britton WR, Blomfield AK, Kamenecka TM, Dunaief JL, Solt LA, Chen J. REV-ERBα regulates age-related and oxidative stress-induced degeneration in retinal pigment epithelium via NRF2. Redox Biol 2022; 51:102261. [PMID: 35176707 PMCID: PMC8851379 DOI: 10.1016/j.redox.2022.102261] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 11/21/2022] Open
Abstract
Retinal pigment epithelium (RPE) dysfunction and atrophy occur in dry age-related macular degeneration (AMD), often leading to photoreceptor degeneration and vision loss. Accumulated oxidative stress during aging contributes to RPE dysfunction and degeneration. Here we show that the nuclear receptor REV-ERBα, a redox sensitive transcription factor, protects RPE from age-related degeneration and oxidative stress-induced damage. Genetic deficiency of REV-ERBα leads to accumulated oxidative stress, dysfunction and degeneration of RPE, and AMD-like ocular pathologies in aging mice. Loss of REV-ERBα exacerbates chemical-induced RPE damage, and pharmacological activation of REV-ERBα protects RPE from oxidative damage both in vivo and in vitro. REV-ERBα directly regulates transcription of nuclear factor erythroid 2-related factor 2 (NRF2) and its downstream antioxidant enzymes superoxide dismutase 1 (SOD1) and catalase to counter oxidative damage. Moreover, aged mice with RPE specific knockout of REV-ERBα also exhibit accumulated oxidative stress and fundus and RPE pathologies. Together, our results suggest that REV-ERBα is a novel intrinsic protector of the RPE against age-dependent oxidative stress and a new molecular target for developing potential therapies to treat age-related retinal degeneration.
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Raimondi R, Zollet P, De Rosa FP, Tsoutsanis P, Stravalaci M, Paulis M, Inforzato A, Romano MR. Where Are We with RPE Replacement Therapy? A Translational Review from the Ophthalmologist Perspective. Int J Mol Sci 2022; 23:ijms23020682. [PMID: 35054869 PMCID: PMC8775975 DOI: 10.3390/ijms23020682] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/28/2021] [Accepted: 12/30/2021] [Indexed: 02/06/2023] Open
Abstract
The retinal pigmented epithelium (RPE) plays a pivotal role in retinal homeostasis. It is therefore an interesting target to fill the unmet medical need of different retinal diseases, including age-related macular degeneration and Stargardt disease. RPE replacement therapy may use different cellular sources: induced pluripotent stem cells or embryonic stem cells. Cells can be transferred as suspension on a patch with different surgical approaches. Results are promising although based on very limited samples. In this review, we summarize the current progress of RPE replacement and provide a comparative assessment of different published approaches which may become standard of care in the future.
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Affiliation(s)
- Raffaele Raimondi
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano–Milan, Italy; (P.Z.); (M.S.); (M.P.); (A.I.)
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
- Correspondence:
| | - Piero Zollet
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano–Milan, Italy; (P.Z.); (M.S.); (M.P.); (A.I.)
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
| | - Francesco Paolo De Rosa
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
| | - Panagiotis Tsoutsanis
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
| | - Matteo Stravalaci
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano–Milan, Italy; (P.Z.); (M.S.); (M.P.); (A.I.)
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
| | - Marianna Paulis
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano–Milan, Italy; (P.Z.); (M.S.); (M.P.); (A.I.)
- Institute of Genetic and Biomedical Research (IRGB), UOS of Milan, National Research Council of Italy, 20138 Milan, Italy
| | - Antonio Inforzato
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano–Milan, Italy; (P.Z.); (M.S.); (M.P.); (A.I.)
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
| | - Mario R. Romano
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, 20072 Pieve Emanuele–Milan, Italy; (F.P.D.R.); (P.T.); (M.R.R.)
- Eye Center, Humanitas Gavazzeni-Castelli, 24128 Bergamo, Italy
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MERTK-Mediated LC3-Associated Phagocytosis (LAP) of Apoptotic Substrates in Blood-Separated Tissues: Retina, Testis, Ovarian Follicles. Cells 2021; 10:cells10061443. [PMID: 34207717 PMCID: PMC8229618 DOI: 10.3390/cells10061443] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/05/2021] [Accepted: 06/07/2021] [Indexed: 01/22/2023] Open
Abstract
Timely and efficient elimination of apoptotic substrates, continuously produced during one’s lifespan, is a vital need for all tissues of the body. This task is achieved by cells endowed with phagocytic activity. In blood-separated tissues such as the retina, the testis and the ovaries, the resident cells of epithelial origin as retinal pigmented epithelial cells (RPE), testis Sertoli cells and ovarian granulosa cells (GC) provide phagocytic cleaning of apoptotic cells and cell membranes. Disruption of this process leads to functional ablation as blindness in the retina and compromised fertility in males and females. To ensure the efficient elimination of apoptotic substrates, RPE, Sertoli cells and GC combine various mechanisms allowing maintenance of tissue homeostasis and avoiding acute inflammation, tissue disorganization and functional ablation. In tight cooperation with other phagocytosis receptors, MERTK—a member of the TAM family of receptor tyrosine kinases (RTK)—plays a pivotal role in apoptotic substrate cleaning from the retina, the testis and the ovaries through unconventional autophagy-assisted phagocytosis process LAP (LC3-associated phagocytosis). In this review, we focus on the interplay between TAM RTKs, autophagy-related proteins, LAP, and Toll-like receptors (TLR), as well as the regulatory mechanisms allowing these components to sustain tissue homeostasis and prevent functional ablation of the retina, the testis and the ovaries.
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Ectopic expression of BBS1 rescues male infertility, but not retinal degeneration, in a BBS1 mouse model. Gene Ther 2021; 29:227-235. [PMID: 33664503 PMCID: PMC9422088 DOI: 10.1038/s41434-021-00241-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 01/12/2021] [Accepted: 02/05/2021] [Indexed: 11/30/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a rare ciliopathy for which there are no current effective treatments. BBS is a genetically heterogeneous disease, though the M390R mutation in BBS1 is involved in approximately 25% of all genetic diagnoses of BBS. The principle features of BBS include retinal degeneration, obesity, male infertility, polydactyly, intellectual disability, and renal abnormalities. Patients with mutations in BBS genes often present with night blindness within the first decade of life, which progresses to complete blindness. This is due to progressive loss of photoreceptor cells. Male infertility is caused by a lack of spermatozoa flagella, rendering them immobile. In this study, we have crossed the wild-type human BBS1 gene, driven by the CAG promoter, onto the Bbs1M390R/M390R mouse model to determine if ectopic expression of BBS1 rescues male infertility and retinal degeneration. qRT-PCR indicates that the BBS1 transgene is expressed in multiple tissues throughout the mouse, with the highest expression seen in the testes, and much lower expression in the eye and hypothalamus. Immunohistochemistry of the transgene in the eye showed little if any expression in the photoreceptor outer nuclear layer. When male Bbs1M30R/M390R;BBS1TG+ mice are housed with WT females, they are able to sire offspring, indicating that the male infertility phenotype of BBS is rescued by the transgene. Using electroretinography (ERGs) to measure retinal function and optical coherence tomography to measure retinal thickness, we show that the transgene does not confer protection against retinal degeneration in Bbs1M300R/M390R;BBS1TG+ mice. The results of this study indicate the male infertility aspect of BBS is an attractive target for gene therapy.
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Kim J, Park JY, Kong JS, Lee H, Won JY, Cho DW. Development of 3D Printed Bruch's Membrane-Mimetic Substance for the Maturation of Retinal Pigment Epithelial Cells. Int J Mol Sci 2021; 22:ijms22031095. [PMID: 33499245 PMCID: PMC7865340 DOI: 10.3390/ijms22031095] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 12/15/2022] Open
Abstract
Retinal pigment epithelium (RPE) is a monolayer of the pigmented cells that lies on the thin extracellular matrix called Bruch's membrane. This monolayer is the main component of the outer blood-retinal barrier (BRB), which plays a multifunctional role. Due to their crucial roles, the damage of this epithelium causes a wide range of diseases related to retinal degeneration including age-related macular degeneration, retinitis pigmentosa, and Stargardt disease. Unfortunately, there is presently no cure for these diseases. Clinically implantable RPE for humans is under development, and there is no practical examination platform for drug development. Here, we developed porcine Bruch's membrane-derived bioink (BM-ECM). Compared to conventional laminin, the RPE cells on BM-ECM showed enhanced functionality of RPE. Furthermore, we developed the Bruch's membrane-mimetic substrate (BMS) via the integration of BM-ECM and 3D printing technology, which revealed structure and extracellular matrix components similar to those of natural Bruch's membrane. The developed BMS facilitated the appropriate functions of RPE, including barrier and clearance functions, the secretion of anti-angiogenic growth factors, and enzyme formation for phototransduction. Moreover, it could be used as a basement frame for RPE transplantation. We established BMS using 3D printing technology to grow RPE cells with functions that could be used for an in vitro model and RPE transplantation.
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Affiliation(s)
- Jongmin Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (J.K.); (J.Y.P.); (H.L.)
| | - Ju Young Park
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (J.K.); (J.Y.P.); (H.L.)
| | - Jeong Sik Kong
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea;
| | - Hyungseok Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (J.K.); (J.Y.P.); (H.L.)
- Department of Mechanical and Biomedical Engineering, Kangwon National University, Chuncheon 24341, Korea
| | - Jae Yon Won
- Department of Ophthalmology and Visual Science, Eunpyeong St. Mary’s Hospital, The Catholic University of Korea, Seoul 03312, Korea
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul 14662, Korea
- Correspondence: (J.Y.W.); (D.W.C.)
| | - Dong Woo Cho
- Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea; (J.K.); (J.Y.P.); (H.L.)
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea;
- Institute of Convergence Science, Yonsei University, Seoul 03722, Korea
- Correspondence: (J.Y.W.); (D.W.C.)
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Selective knockdown of hexokinase 2 in rods leads to age-related photoreceptor degeneration and retinal metabolic remodeling. Cell Death Dis 2020; 11:885. [PMID: 33082308 PMCID: PMC7576789 DOI: 10.1038/s41419-020-03103-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022]
Abstract
Photoreceptors, the primary site of phototransduction in the retina, require energy and metabolites to constantly renew their outer segments. They preferentially consume most glucose through aerobic glycolysis despite possessing abundant mitochondria and enzymes for oxidative phosphorylation (OXPHOS). Exactly how photoreceptors balance aerobic glycolysis and mitochondrial OXPHOS to regulate their survival is still unclear. We crossed rhodopsin-Cre mice with hexokinase 2 (HK2)-floxed mice to study the effect of knocking down HK2, the first rate-limiting enzyme in glycolysis, on retinal health and metabolic remodeling. Immunohistochemistry and Western blots were performed to study changes in photoreceptor-specific proteins and key enzymes in glycolysis and the tricarboxylic acid (TCA) cycle. Changes in retinal structure and function were studied by optical coherence tomography and electroretinography. Mass spectrometry was performed to profile changes in 13C-glucose-derived metabolites in glycolysis and the TCA cycle. We found that knocking down HK2 in rods led to age-related photoreceptor degeneration, evidenced by reduced expression of photoreceptor-specific proteins, age-related reductions of the outer nuclear layer, photoreceptor inner and outer segments and impaired electroretinographic responses. Loss of HK2 in rods led to upregulation of HK1, phosphorylation of pyruvate kinase muscle isozyme 2, mitochondrial stress proteins and enzymes in the TCA cycle. Mass spectrometry found that the deletion of HK2 in rods resulted in accumulation of 13C-glucose along with decreased pyruvate and increased metabolites in the TCA cycle. Our data suggest that HK2-mediated aerobic glycolysis is indispensable for the maintenance of photoreceptor structure and function and that long-term inhibition of glycolysis leads to photoreceptor degeneration.
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Ethanol-Induced Oxidative Stress Modifies Inflammation and Angiogenesis Biomarkers in Retinal Pigment Epithelial Cells (ARPE-19): Role of CYP2E1 and its Inhibition by Antioxidants. Antioxidants (Basel) 2020; 9:antiox9090776. [PMID: 32825644 PMCID: PMC7555214 DOI: 10.3390/antiox9090776] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/15/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022] Open
Abstract
The retinal pigment epithelium (RPE) plays a key role in retinal health, being essential for the protection against reactive oxygen species (ROS). Nevertheless, excessive oxidative stress can induce RPE dysfunction, promoting visual loss. Our aim is to clarify the possible implication of CYP2E1 in ethanol (EtOH)-induced oxidative stress in RPE alterations. Despite the increase in the levels of ROS, measured by fluorescence probes, the RPE cells exposed to the lowest EtOH concentrations were able to maintain cell survival, measured by the Cell Proliferation Kit II (XTT). However, EtOH-induced oxidative stress modified inflammation and angiogenesis biomarkers, analyzed by proteome array, ELISA, qPCR and Western blot. The highest EtOH concentration used stimulated a large increase in ROS levels, upregulating the cytochrome P450-2E1 (CYP2E1) and promoting cell death. The use of antioxidants such as N-acetylcysteine (NAC) and diallyl sulfide (DAS), which is also a CYP2E1 inhibitor, reverted cell death and oxidative stress, modulating also the upstream angiogenesis and inflammation regulators. Because oxidative stress plays a central role in most frequent ocular diseases, the results herein support the proposal that CYP2E1 upregulation could aggravate retinal degeneration, especially in those patients with high baseline oxidative stress levels due to their ocular pathology and should be considered as a risk factor.
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21
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CORRELATIONS BETWEEN CHANGES IN PHOTORECEPTOR LAYER AND OTHER CLINICAL CHARACTERISTICS IN CENTRAL SEROUS CHORIORETINOPATHY. Retina 2020; 39:1110-1116. [PMID: 29401176 PMCID: PMC6553978 DOI: 10.1097/iae.0000000000002092] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study of 222 eyes with central serous chorioretinopathy demonstrates that morphologic changes in photoreceptor layer, visual acuity, decreasing foveal outer nuclear layer thickness, and symptom duration correlated closely but may behave asynchronously. These objective parameters, besides symptom duration, could be helpful when considering the timing of CSC treatment. Purpose: To clarify the correlations between changes in the photoreceptor layer (PRL) and other clinical characteristics during central serous chorioretinopathy. Methods: Patients with central serous chorioretinopathy with one eye affected were enrolled. Photoreceptor layer appearance within the detached area was evaluated, and its correlations with symptom duration, best-corrected visual acuity, and the difference in the foveal outer nuclear layer thickness between the affected and contralateral eyes were analyzed. Results: A total of 222 patients were included. The PRL outer border appeared either smooth, granulated, or as scattered dots attached to external limiting membrane. These different appearances were associated with elongation in symptom duration (18, 180, and 1,855 days), decreases in best-corrected visual acuity (6/10, 6/15, and 6/120), and increases in the difference of foveal outer nuclear layer thickness (−16, −32, and −60 μm). Among eyes with smooth PRL outer border, which had similar symptom duration, eyes with foveal PRL defect had poorer best-corrected visual acuity and greater reduction in outer nuclear layer thickness than the other eyes (all P = 0.00). Conclusion: Morphologic changes in PRL, best-corrected visual acuity, the reduction in foveal outer nuclear layer thickness, and symptom duration correlate closely but may behave asynchronously. These objective parameters, besides symptom duration, could be helpful when considering the timing of central serous chorioretinopathy treatment.
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22
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Olchawa MM, Szewczyk GM, Zadlo AC, Krzysztynska-Kuleta OI, Sarna TJ. The effect of aging and antioxidants on photoreactivity and phototoxicity of human melanosomes: An in vitro study. Pigment Cell Melanoma Res 2020; 34:670-682. [PMID: 32702137 DOI: 10.1111/pcmr.12914] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/19/2020] [Accepted: 07/07/2020] [Indexed: 01/08/2023]
Abstract
Aging may significantly modify antioxidant and photoprotective properties of melanin in retinal pigment epithelium (RPE). Here, photoreactivity of melanosomes (MS), isolated from younger and older human donors with and without added zeaxanthin and α-tocopherol, was analyzed by electron paramagnetic resonance oximetry, time-resolved singlet oxygen phosphorescence, and protein oxidation assay. The phototoxic potential of ingested melanosomes was examined in ARPE-19 cells exposed to blue light. Phagocytosis of FITC-labeled photoreceptor outer segments (POS) isolated from bovine retinas was determined by flow cytometry. Irradiation of cells fed MS induced significant inhibition of the specific phagocytosis with the effect being stronger for melanosomes from older than from younger human cohorts, and enrichment of the melanosomes with antioxidants reduced the inhibitory effect. Cellular protein photooxidation was more pronounced in samples containing older melanosomes, and it was diminished by antioxidants. This study suggests that blue light irradiated RPE melanosomes could induce substantial inhibition of the key function of the cells-their specific phagocytosis. The data indicate that while photoreactivity of MS and their phototoxic potential increase with age, they could be reduced by selected natural antioxidants.
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Affiliation(s)
- Magdalena M Olchawa
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Grzegorz M Szewczyk
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Andrzej C Zadlo
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Olga I Krzysztynska-Kuleta
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Tadeusz J Sarna
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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Chen HY, Kelley RA, Li T, Swaroop A. Primary cilia biogenesis and associated retinal ciliopathies. Semin Cell Dev Biol 2020; 110:70-88. [PMID: 32747192 PMCID: PMC7855621 DOI: 10.1016/j.semcdb.2020.07.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 12/19/2022]
Abstract
The primary cilium is a ubiquitous microtubule-based organelle that senses external environment and modulates diverse signaling pathways in different cell types and tissues. The cilium originates from the mother centriole through a complex set of cellular events requiring hundreds of distinct components. Aberrant ciliogenesis or ciliary transport leads to a broad spectrum of clinical entities with overlapping yet highly variable phenotypes, collectively called ciliopathies, which include sensory defects and syndromic disorders with multi-organ pathologies. For efficient light detection, photoreceptors in the retina elaborate a modified cilium known as the outer segment, which is packed with membranous discs enriched for components of the phototransduction machinery. Retinopathy phenotype involves dysfunction and/or degeneration of the light sensing photoreceptors and is highly penetrant in ciliopathies. This review will discuss primary cilia biogenesis and ciliopathies, with a focus on the retina, and the role of CP110-CEP290-CC2D2A network. We will also explore how recent technologies can advance our understanding of cilia biology and discuss new paradigms for developing potential therapies of retinal ciliopathies.
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Affiliation(s)
- Holly Y Chen
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
| | - Ryan A Kelley
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Tiansen Li
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
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PHOTORECEPTOR OUTER SEGMENT IS EXPANDED IN THE FELLOW EYE OF PATIENTS WITH UNILATERAL CENTRAL SEROUS CHORIORETINOPATHY. Retina 2020; 41:296-301. [DOI: 10.1097/iae.0000000000002846] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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ELONGATED PHOTORECEPTOR OUTER SEGMENT LENGTH AND PROGNOSIS OF CHRONIC CENTRAL SEROUS CHORIORETINOPATHY. Retina 2020; 40:750-757. [DOI: 10.1097/iae.0000000000002445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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26
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Associations with photoreceptor thickness measures in the UK Biobank. Sci Rep 2019; 9:19440. [PMID: 31857628 PMCID: PMC6923366 DOI: 10.1038/s41598-019-55484-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 10/22/2019] [Indexed: 11/08/2022] Open
Abstract
Spectral-domain OCT (SD-OCT) provides high resolution images enabling identification of individual retinal layers. We included 32,923 participants aged 40-69 years old from UK Biobank. Questionnaires, physical examination, and eye examination including SD-OCT imaging were performed. SD OCT measured photoreceptor layer thickness includes photoreceptor layer thickness: inner nuclear layer-retinal pigment epithelium (INL-RPE) and the specific sublayers of the photoreceptor: inner nuclear layer-external limiting membrane (INL-ELM); external limiting membrane-inner segment outer segment (ELM-ISOS); and inner segment outer segment-retinal pigment epithelium (ISOS-RPE). In multivariate regression models, the total average INL-RPE was observed to be thinner in older aged, females, Black ethnicity, smokers, participants with higher systolic blood pressure, more negative refractive error, lower IOPcc and lower corneal hysteresis. The overall INL-ELM, ELM-ISOS and ISOS-RPE thickness was significantly associated with sex and race. Total average of INL-ELM thickness was additionally associated with age and refractive error, while ELM-ISOS was additionally associated with age, smoking status, SBP and refractive error; and ISOS-RPE was additionally associated with smoking status, IOPcc and corneal hysteresis. Hence, we found novel associations of ethnicity, smoking, systolic blood pressure, refraction, IOPcc and corneal hysteresis with photoreceptor thickness.
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Gill JS, Moosajee M, Dubis AM. Cellular imaging of inherited retinal diseases using adaptive optics. Eye (Lond) 2019; 33:1683-1698. [PMID: 31164730 PMCID: PMC7002587 DOI: 10.1038/s41433-019-0474-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/25/2019] [Accepted: 04/25/2019] [Indexed: 12/14/2022] Open
Abstract
Adaptive optics (AO) is an insightful tool that has been increasingly applied to existing imaging systems for viewing the retina at a cellular level. By correcting for individual optical aberrations, AO offers an improvement in transverse resolution from 10-15 μm to ~2 μm, enabling assessment of individual retinal cell types. One of the settings in which its utility has been recognised is that of the inherited retinal diseases (IRDs), the genetic and clinical heterogeneity of which warrants better cellular characterisation. In this review, we provide a summary of the basic principles of AO, its integration into multiple retinal imaging modalities and its clinical applications, focusing primarily on IRDs. Furthermore, we present a comprehensive summary of AO-based cellular findings in IRDs according to their associated disease-causing genes.
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Affiliation(s)
- Jasdeep S Gill
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, 162 City Road, London, EC1V 9PD, UK
- Great Ormond Street Hospital for Children, Great Ormond Street, London, WC1N 3JH, UK
| | - Adam M Dubis
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, 162 City Road, London, EC1V 9PD, UK.
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Pawlak AM, Olchawa M, Koscielniak A, Zadlo A, Broniec A, Oles T, Sarna TJ. Oxidized Lipids Decrease Phagocytic Activity of ARPE‐19 Cells In Vitro. EUR J LIPID SCI TECH 2019. [DOI: 10.1002/ejlt.201800476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Anna M. Pawlak
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
| | - Magdalena Olchawa
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
| | - Anna Koscielniak
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
- Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical EngineeringAGH‐University of Science and Technology30‐059 KrakówPoland
| | - Andrzej Zadlo
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
| | - Agnieszka Broniec
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
| | - Tomasz Oles
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
| | - Tadeusz J. Sarna
- Faculty of BiochemistryDepartment of Biophysics, Biophysics and BiotechnologyJagiellonian University30‐007 KrakowPoland
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29
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Eynard AR, Repossi G. Role of ω3 polyunsaturated fatty acids in diabetic retinopathy: a morphological and metabolically cross talk among blood retina barriers damage, autoimmunity and chronic inflammation. Lipids Health Dis 2019; 18:114. [PMID: 31092270 PMCID: PMC6521493 DOI: 10.1186/s12944-019-1049-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 04/12/2019] [Indexed: 12/11/2022] Open
Abstract
Vision disorders are one of the most serious complications of diabetes mellitus (DM) affecting the quality of life of patients and eventually cause blindness. The ocular lesions in diabetes mellitus are located mainly in the blood vessels and retina layers. Different retina lesions could be grouped under the umbrella term of diabetic retinopathies (DMRP). We propose that one of the main causes in the etiopathogenesis of the DMRP consists of a progressive loss of the selective permeability of blood retinal barriers (BRB). The loss of selective permeability of blood retinal barriers will cause a progressive autoimmune process. Prolonged autoimmune injures in the retinal territory will triggers and maintains a low-grade chronic inflammation process, microvascular alterations, glial proliferation and subsequent fibrosis and worse, progressive apoptosis of the photoreceptor neurons. Patients with long-standing DM disturbances in retinal BRBs suffer of alterations in the enzymatic pathways of polyunsaturated fatty acids (PUFAs), increase release of free radicals and pro-inflammatory molecules and subsequently incremented levels of vascular endothelial growth factor. These facts can produce retinal edema and photoreceptor apoptosis. Experimental, clinical and epidemiological evidences showing that adequate metabolic and alimentary controls and constant practices of healthy life may avoid, retard or make less severe the appearance of DMRP. Considering the high demand for PUFAs ω3 by photoreceptor complexes of the retina, it seems advisable to take fish oil supplements (2 g per day). The cellular, subcellular and molecular basis of the propositions exposed above is developed in this article. Synthesizer drawings the most relevant findings of the ultrastructural pathology, as well as the main metabolic pathways of the PUFAs involved in balance and disbalanced conditions are provided.
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Affiliation(s)
- Aldo R Eynard
- Instituto de Biología Celular, Histología y Embriología, Facultad de Ciencias Médicas, INICSA (CONICET-Universidad Nacional de Córdoba), Córdoba, Argentina.
| | - Gaston Repossi
- Instituto de Biología Celular, Histología y Embriología, Facultad de Ciencias Médicas, INICSA (CONICET-Universidad Nacional de Córdoba), Córdoba, Argentina.
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30
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Felder-Schmittbuhl MP, Buhr ED, Dkhissi-Benyahya O, Hicks D, Peirson SN, Ribelayga CP, Sandu C, Spessert R, Tosini G. Ocular Clocks: Adapting Mechanisms for Eye Functions and Health. Invest Ophthalmol Vis Sci 2019; 59:4856-4870. [PMID: 30347082 PMCID: PMC6181243 DOI: 10.1167/iovs.18-24957] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Vision is a highly rhythmic function adapted to the extensive changes in light intensity occurring over the 24-hour day. This adaptation relies on rhythms in cellular and molecular processes, which are orchestrated by a network of circadian clocks located within the retina and in the eye, synchronized to the day/night cycle and which, together, fine-tune detection and processing of light information over the 24-hour period and ensure retinal homeostasis. Systematic or high throughput studies revealed a series of genes rhythmically expressed in the retina, pointing at specific functions or pathways under circadian control. Conversely, knockout studies demonstrated that the circadian clock regulates retinal processing of light information. In addition, recent data revealed that it also plays a role in development as well as in aging of the retina. Regarding synchronization by the light/dark cycle, the retina displays the unique property of bringing together light sensitivity, clock machinery, and a wide range of rhythmic outputs. Melatonin and dopamine play a particular role in this system, being both outputs and inputs for clocks. The retinal cellular complexity suggests that mechanisms of regulation by light are diverse and intricate. In the context of the whole eye, the retina looks like a major determinant of phase resetting for other tissues such as the retinal pigmented epithelium or cornea. Understanding the pathways linking the cell-specific molecular machineries to their cognate outputs will be one of the major challenges for the future.
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Affiliation(s)
- Marie-Paule Felder-Schmittbuhl
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives (UPR 3212), Strasbourg, France
| | - Ethan D Buhr
- Department of Ophthalmology, University of Washington Medical School, Seattle, Washington, United States
| | - Ouria Dkhissi-Benyahya
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, Bron, France
| | - David Hicks
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives (UPR 3212), Strasbourg, France
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Christophe P Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States
| | - Cristina Sandu
- Centre National de la Recherche Scientifique, Université de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives (UPR 3212), Strasbourg, France
| | - Rainer Spessert
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology & Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States
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31
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Olchawa M, Krzysztynska-Kuleta O, Duda M, Pawlak A, Pabisz P, Czuba-Pelech B, Sarna T. In vitro phototoxicity of rhodopsin photobleaching products in the retinal pigment epithelium (RPE). Free Radic Res 2019; 53:456-471. [DOI: 10.1080/10715762.2019.1603377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Magdalena Olchawa
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Olga Krzysztynska-Kuleta
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
- Laboratory of Imaging and Atomic Force Spectroscopy, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Mariusz Duda
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
- Laboratory of Imaging and Atomic Force Spectroscopy, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Anna Pawlak
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Pawel Pabisz
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Barbara Czuba-Pelech
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Tadeusz Sarna
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
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32
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Correlation between preoperative factors and final visual acuity after successful rhegmatogenous retinal reattachment. Sci Rep 2019; 9:3217. [PMID: 30824755 PMCID: PMC6397257 DOI: 10.1038/s41598-019-39839-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/31/2019] [Indexed: 11/08/2022] Open
Abstract
We evaluated the preoperative optical coherence tomographic (OCT) findings in eyes with macula-off rhegmatogenous retinal detachment (RRD) and determined the factors that were significantly correlated with the postoperative best-corrected visual acuity (BCVA). The length of the preoperative photoreceptors was defined as the distance between the external limiting membrane (ELM) and the outer end of the outer segments of the photoreceptors in the OCT images. The mean length of the photoreceptors was 102.8 ± 28.7 µm with a range of 20 to 159 µm in eyes with RRD. The length of the preoperative photoreceptors was not significantly correlated with the preoperative BCVA but it was significantly correlated with the postoperative BCVA (r = -0.353, P = 0.003). Multivariate regression analyses revealed that the length of the photoreceptors (β = -0.388, P = 0.001) and the preoperative BCVA (β = 0.274, P = 0.021) were the only independent factors that were significantly associated with the postoperative BCVA. The length of the preoperative photoreceptors was significantly correlated with the postoperative photoreceptor length (r = 0.486, P < 0.001). Longer preoperative photoreceptors were significantly correlated with longer postoperative photoreceptors and better BCVA after successful reattachment. These results suggest that the preoperative length of the photoreceptors can be good factor to use for predicting the final BCVA following successful reattachment of macula-off RRD.
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Donato L, Scimone C, Nicocia G, D'Angelo R, Sidoti A. Role of oxidative stress in Retinitis pigmentosa: new involved pathways by an RNA-Seq analysis. Cell Cycle 2018; 18:84-104. [PMID: 30569795 DOI: 10.1080/15384101.2018.1558873] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Retinitis pigmentosa (RP) is a very heterogeneous inherited ocular disorder group characterized by progressive retinal disruption. Retinal pigment epithelium (RPE) degeneration, due to oxidative stress which arrests the metabolic support to photoreceptors, represents one of the principal causes of RP. Here, the role of oxidative stress in RP onset and progression was analyzed by a comparative whole transcriptome analysis of human RPE cells, treated with 100 µg/ml of oxLDL and untreated, at different time points. Experiment was thrice repeated and performed on Ion ProtonTM sequencing system. Data analysis, including low quality reads trimming and gene expression quantification, was realized by CLC Genomics Workbench software. The whole analysis highlighted 14 clustered "macro-pathways" and many sub-pathways, classified by selection of 5271 genes showing the highest alteration of expression. Among them, 23 genes were already known to be RP causative ones (15 over-expressed and 8 down-expressed), and their enrichment and intersection analyses highlighted new 77 candidate related genes (49 over-expressed and 28 down-expressed). A final filtering analysis then highlighted 29 proposed candidate genes. This data suggests that many new genes, not yet associated with RP, could influence its etiopathogenesis.
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Affiliation(s)
- Luigi Donato
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
| | - Concetta Scimone
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
| | - Giacomo Nicocia
- c Department of Clinical and Experimental Medicine , University of Messina , Messina , Italy
| | - Rosalia D'Angelo
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
| | - Antonina Sidoti
- a Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine , University of Messina , Messina , Italy.,b Department of Cutting-Edge Medicine and Therapies, Biomolecular Strategies and Neuroscience, Section of Applied Neuroscience, Molecular Genetics and Predictive Medicine , I.E.ME.S.T. ., Palermo , Italy
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Ioshimoto GL, Camargo AA, Liber AMP, Nagy BV, Damico FM, Ventura DF. Comparison between albino and pigmented rabbit ERGs. Doc Ophthalmol 2018; 136:113-123. [PMID: 29572760 DOI: 10.1007/s10633-018-9628-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 03/06/2018] [Indexed: 10/17/2022]
Abstract
BACKGROUND Pigmented and albino rabbits are commonly used in visual research; however, the lack of pigment in the eyes may affect retinal responses. Here, we compare and describe the differences of retinal function between pigmented (English Butterfly) and albino (New Zealand) rabbits. METHODS Electroretinograms were recorded in pigmented and albino rabbits in the dark-adapted eye, in the light-adapted eye and for four temporal frequencies in the light-adapted eye. The implicit time and amplitude of the a- and b-waves were analyzed, as well as the amplitude and phase of the first harmonic component of the photopic flicker response. RESULTS Albino rabbits presented significantly larger amplitudes for both a- and b-waves at all intensities and frequencies. The intensity-response function of the scotopic b-wave also showed that the albino retina is more sensitive than the pigmented retina and the larger flicker amplitudes found in the albino group also revealed post-receptoral changes specifically related to cone pathways. CONCLUSIONS The larger amplitude of albino receptoral and post-receptoral activities might be attributed to greater availability of light due to scatter and reflection at the retinal layer, and as the differences in response amplitudes between the groups increase with flicker frequency, we suggest that ON bipolar cells recover faster in the albino group, suggesting that this might be a mechanism to explain the higher temporal resolution for albinos compared to the pigmented group.
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Affiliation(s)
- Gabriela Lourençon Ioshimoto
- Department of Experimental Psychology, Institute of Psychology, Universidade de São Paulo, Av. Prof. Mello Moraes 1721, Cidade Universitária, São Paulo, SP, CEP 05508-030, Brazil.
| | - Amanda Alves Camargo
- Department of Experimental Psychology, Institute of Psychology, Universidade de São Paulo, Av. Prof. Mello Moraes 1721, Cidade Universitária, São Paulo, SP, CEP 05508-030, Brazil
| | - André Maurício Passos Liber
- Department of Experimental Psychology, Institute of Psychology, Universidade de São Paulo, Av. Prof. Mello Moraes 1721, Cidade Universitária, São Paulo, SP, CEP 05508-030, Brazil
| | - Balázs Vince Nagy
- Department of Experimental Psychology, Institute of Psychology, Universidade de São Paulo, Av. Prof. Mello Moraes 1721, Cidade Universitária, São Paulo, SP, CEP 05508-030, Brazil
| | - Francisco Max Damico
- Department of Ophthalmology, Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Dora Fix Ventura
- Department of Experimental Psychology, Institute of Psychology, Universidade de São Paulo, Av. Prof. Mello Moraes 1721, Cidade Universitária, São Paulo, SP, CEP 05508-030, Brazil
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35
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Koscielniak A, Serafin M, Duda M, Oles T, Zadlo A, Broniec A, Berdeaux O, Gregoire S, Bretillon L, Sarna T, Pawlak A. Oxidation-Induced Increase In Photoreactivity of Bovine Retinal Lipid Extract. Cell Biochem Biophys 2017; 75:443-454. [PMID: 29098642 PMCID: PMC5691103 DOI: 10.1007/s12013-017-0832-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 10/10/2017] [Indexed: 12/14/2022]
Abstract
The mammalian retina contains a high level of polyunsaturated fatty acids, including docosahexaenoic acid (22:6) (DHA), which are highly susceptible to oxidation. It has been shown that one of the products of DHA oxidation-carboxyethylpyrrole (CEP), generated in situ, causes modifications of retinal proteins and induces inflammation response in the outer retina. These contributing factors may play a role in the development of age-related macular degeneration (AMD). It is also possible that some of the lipid oxidation products are photoreactive, and upon irradiation with blue light may generate reactive oxygen species. Therefore, in this work we analysed oxidation-induced changes in photoreactivity of lipids extracted from bovine neural retinas. Lipid composition of bovine neural retinas closely resembles that of human retinas making the bovine tissue a convenient model for studying the photoreactivity and potential phototoxicity of oxidized human retinal lipids. Lipid composition of bovine neural retinas Folch' extracts (BRex) was determined by gas chromatography (GC) and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS) analysis. Liposomes prepared from BRex, equilibrated with air, were oxidized in the dark at 37 °C for up to 400 h. The photoreactivity of BRex at different stages of oxidation was studied by EPR-oximetry and EPR-spin trapping. Photogeneration of singlet oxygen (1O2, 1Δg) by BRex was measured using time-resolved detection of the characteristic phosphorescence at 1270 nm. To establish contribution of lipid components to the analysed photoreactivity of Folch' extract of bovine retinas, a mixture of selected synthetic lipids in percent by weight (w/w %) ratio resembling that of the BRex has been also studied. Folch's extraction of bovine neural retinas was very susceptible to oxidation despite the presence of powerful endogenous antioxidants such as α-tocopherol and zeaxanthin. Non-oxidized and oxidized BRex photogenerated singlet oxygen with moderate quantum yield. Blue-light induced generation of superoxide anion by Folch' extract of bovine neural retinas strongly depended on the oxidation time. The observed photoreactivity of the studied extract gradually increased during its in vitro oxidation.
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Affiliation(s)
- A Koscielniak
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.,Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical Engineering, AGH-University of Science and Technology, Kraków, Poland
| | - M Serafin
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - M Duda
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - T Oles
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - A Zadlo
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - A Broniec
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - O Berdeaux
- INRA, Centre des Sciences du Gout et de l'Alimentation, Universite de Bourgogne, Dijon, France
| | - S Gregoire
- INRA, Centre des Sciences du Gout et de l'Alimentation, Universite de Bourgogne, Dijon, France
| | - L Bretillon
- INRA, Centre des Sciences du Gout et de l'Alimentation, Universite de Bourgogne, Dijon, France
| | - T Sarna
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - A Pawlak
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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Laurent V, Sengupta A, Sánchez-Bretaño A, Hicks D, Tosini G. Melatonin signaling affects the timing in the daily rhythm of phagocytic activity by the retinal pigment epithelium. Exp Eye Res 2017; 165:90-95. [PMID: 28941766 DOI: 10.1016/j.exer.2017.09.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/07/2017] [Accepted: 09/17/2017] [Indexed: 11/30/2022]
Abstract
Earlier studies in Xenopus have indicated a role for melatonin in the regulation of retinal disk shedding, but the role of melatonin in the regulation of daily rhythm in mammalian disk shedding and phagocytosis is still unclear. We recently produced a series of transgenic mice lacking melatonin receptor type 1 (MT1) or type 2 (MT2) in a melatonin-proficient background and have shown that removal of MT1 and MT2 receptors induces significant effects on daily and circadian regulation of the electroretinogram as well as on the viability of photoreceptor cells during aging. In this study we investigated the daily rhythm of phagocytic activity by the retinal pigment epithelium in MT1 and MT2 knock-out mice. Our data indicate that in MT1 and MT2 knock-out mice the peak of phagocytosis is advanced by 3 h with respect to wild-type mice and occurred in dark rather than after the onset of light, albeit the mean phagocytic activity over the 24-h period did not change among the three genotypes. Nevertheless, this small change in the profile of daily phagocytic rhythms may produce a significant effect on retinal health since MT1 and MT2 knock-out mice showed a significant increase in lipofuscin accumulation in the retinal pigment epithelium.
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Affiliation(s)
- Virgine Laurent
- Institut des Neurosciences Cellulaires et Intégratives (INCI), CNRS UPR3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Anamika Sengupta
- Neuroscience Institute, Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, USA
| | - Aída Sánchez-Bretaño
- Neuroscience Institute, Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, USA
| | - David Hicks
- Institut des Neurosciences Cellulaires et Intégratives (INCI), CNRS UPR3212, 5 rue Blaise Pascal, 67084 Strasbourg, France
| | - Gianluca Tosini
- Neuroscience Institute, Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, USA.
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Murase H, Tsuruma K, Kuse Y, Shimazawa M, Hara H. Progranulin increases phagocytosis by retinal pigment epithelial cells in culture. J Neurosci Res 2017; 95:2500-2510. [PMID: 28509387 DOI: 10.1002/jnr.24081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 03/28/2017] [Accepted: 04/18/2017] [Indexed: 11/07/2022]
Abstract
Retinal pigment epithelium (RPE) cells take part in retinal preservation, such as phagocytizing the shed photoreceptor outer segments (POS), every day. The incomplete phagocytic function accelerates RPE degeneration and formation of the toxic by-product lipofuscin. Excessive lipofuscin accumulation is characteristic of various blinding diseases in the human eye. Progranulin is a cysteine-rich protein that has multiple biological activities, and it has a high presence in the retina. Progranulin has been recognized to be involved in macrophage phagocytosis in the brain. The purpose of this study is to determine whether progranulin influences phagocytosis by RPE cells. All experiments were performed on primary human RPE (hRPE) cells in culture. pHrodo was used to label the isolated porcine POS, and quantification of pHrodo fluorescence was used to determine the degree of phagocytosis. Western blotting and immunohistochemistry of key proteins involved in phagocytosis were used to clarify the mechanism of progranulin. Progranulin increased RPE phagocytosis in hydrogen peroxide-treated and nontreated RPE cells. The phosphorylated form of Mer tyrosine kinase, which is important for POS internalization, was significantly increased in the progranulin-exposed cells. This increase was attenuated by SU11274, an inhibitor of hepatic growth factor receptor. Under the oxidative stress condition, exposure to progranulin led to an approximately twofold increase in integrin alpha-v, which is associated with the first step in recognition of POS by RPE cells. These results suggest that progranulin could be an effective stimulator for RPE phagocytosis and could repair RPE function. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Hiromi Murase
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Kazuhiro Tsuruma
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Yoshiki Kuse
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu, 501-1196, Japan
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38
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Shams Najafabadi H, Soheili ZS, Samiei S, Ahmadieh H, Ranaei Pirmardan E, Masoumi M. Isolation, Characterization, and Establishment of Spontaneously Immortalized Cell Line HRPE-2S With Stem Cell Properties. J Cell Physiol 2016; 232:2626-2640. [PMID: 27943290 DOI: 10.1002/jcp.25729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/08/2016] [Indexed: 11/10/2022]
Abstract
The retinal pigment epithelium is a monolayer of highly specialized pigmented cells located between the neural retina and the Bruch's membrane of the choroid. RPE cells play a crucial role in the maintenance and function of the underlying photoreceptors. This study introduces a spontaneously arising human retinal pigment epithelial cell line, HRPE-2S, which was isolated from primary RPE cell culture of 2 days old male donor. We characterized morphology and functional properties of the new cell line. The immortalized cell line was maintained in culture for more than 70 passages and 240 divisions. The average doubling time of the cells was approximately 22 h and got freezed at 26th passage. The cell line expressed RPE-specific markers RPE65 and cell junction protein ZO1 as an epithelial cell marker. It also expressed CHX10, PAX6, Nestin, SOX2 as stem and retinal progenitor cell markers. Ki67 as a marker of cell proliferation was expressed in all HRPE-2S cells. It represented typical epithelial cobblestone morphology and did not phenotypically change through several passages. Stem cell-like aggregations (neurospheres) were observed in SEM microscopy. The cells represented high mitotic index. They could be viable under hypoxic conditions and serum deprivation. According to functional studies, the cell line exhibited stem cell-like behaviors with particular emphasis on its self-renewal capacity. LDH isoenzymes expression pattern confirmed the same cellular source for both of the HRPE-2S cells and primary RPE cells. Characteristics of HRPE-2S cells promise it as an in vitro model for RPE stem cell-based researches. J. Cell. Physiol. 232: 2626-2640, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Hoda Shams Najafabadi
- Department of Molecular Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Zahra-Soheila Soheili
- Department of Molecular Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Shahram Samiei
- Blood Transfusion Research Center High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Hamid Ahmadieh
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ehsan Ranaei Pirmardan
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Maryam Masoumi
- Department of Molecular Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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Soens ZT, Li Y, Zhao L, Eblimit A, Dharmat R, Li Y, Chen Y, Naqeeb M, Fajardo N, Lopez I, Sun Z, Koenekoop RK, Chen R. Hypomorphic mutations identified in the candidate Leber congenital amaurosis gene CLUAP1. Genet Med 2016; 18:1044-51. [PMID: 26820066 PMCID: PMC4965339 DOI: 10.1038/gim.2015.205] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/04/2015] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Leber congenital amaurosis (LCA) is an early-onset form of retinal degeneration. Six of the 22 known LCA genes encode photoreceptor ciliary proteins. Despite the identification of 22 LCA genes, the genetic basis of ~30% of LCA patients remains unknown. We sought to investigate the cause of disease in the remaining 30% by examining cilia-associated genes. METHODS Whole-exome sequencing was performed on an LCA cohort of 212 unsolved probands previously screened for mutations in known retinal-disease genes. Immunohistochemistry using mouse retinas was used to confirm protein localization and zebrafish were used to perform rescue experiments. RESULTS A homozygous nonsynonymous mutation was found in a single proband in CLUAP1, a gene required for ciliogenesis and cilia maintenance. Cluap1 knockout zebrafish exhibit photoreceptor cell death as early as 5 days after fertilization, and rescue experiments revealed that our proband's mutation is significantly hypomorphic. CONCLUSION Consistent with the knowledge that CLUAP1 plays an important role in cilia function and that cilia are critical to photoreceptor function, our results indicate that hypomorphic mutations in CLUAP1 can result in dysfunctional photoreceptors without systemic abnormalities. This is the first report linking mutations in CLUAP1 to human disease and establishes CLUAP1 as a candidate LCA gene.Genet Med 18 10, 1044-1051.
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Affiliation(s)
- Zachry T. Soens
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
| | - Yuanyuan Li
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Li Zhao
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
- Department of Structural and Computational Biology & Molecular Biophysics, Baylor College of Medicine, Houston, TX 77030, United States
| | - Aiden Eblimit
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
| | - Rachayata Dharmat
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
| | - Yiyun Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
| | - Mohammed Naqeeb
- Department of Ophthalmology, Um Al Qura University Medical School, Makkah, Saudi Arabia
| | - Norma Fajardo
- McGill Ocular Genetics Laboratory and Centre, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, QC H3H 1P3, Canada
| | - Irma Lopez
- McGill Ocular Genetics Laboratory and Centre, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, QC H3H 1P3, Canada
| | - Zhaoxia Sun
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, United States
| | - Robert K. Koenekoop
- McGill Ocular Genetics Laboratory and Centre, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, QC H3H 1P3, Canada
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, United States
- Department of Structural and Computational Biology & Molecular Biophysics, Baylor College of Medicine, Houston, TX 77030, United States
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, United States
- Program of Developmental Biology, Baylor College of Medicine, Houston, TX 77030, United States
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Goldberg AFX, Moritz OL, Williams DS. Molecular basis for photoreceptor outer segment architecture. Prog Retin Eye Res 2016; 55:52-81. [PMID: 27260426 DOI: 10.1016/j.preteyeres.2016.05.003] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 05/27/2016] [Accepted: 05/29/2016] [Indexed: 01/11/2023]
Abstract
To serve vision, vertebrate rod and cone photoreceptors must detect photons, convert the light stimuli into cellular signals, and then convey the encoded information to downstream neurons. Rods and cones are sensory neurons that each rely on specialized ciliary organelles to detect light. These organelles, called outer segments, possess elaborate architectures that include many hundreds of light-sensitive membranous disks arrayed one atop another in precise register. These stacked disks capture light and initiate the chain of molecular and cellular events that underlie normal vision. Outer segment organization is challenged by an inherently dynamic nature; these organelles are subject to a renewal process that replaces a significant fraction of their disks (up to ∼10%) on a daily basis. In addition, a broad range of environmental and genetic insults can disrupt outer segment morphology to impair photoreceptor function and viability. In this chapter, we survey the major progress that has been made for understanding the molecular basis of outer segment architecture. We also discuss key aspects of organelle lipid and protein composition, and highlight distributions, interactions, and potential structural functions of key OS-resident molecules, including: kinesin-2, actin, RP1, prominin-1, protocadherin 21, peripherin-2/rds, rom-1, glutamic acid-rich proteins, and rhodopsin. Finally, we identify key knowledge gaps and challenges that remain for understanding how normal outer segment architecture is established and maintained.
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Affiliation(s)
- Andrew F X Goldberg
- Eye Research Institute, Oakland University, 417 Dodge Hall, Rochester, MI, 48309, USA.
| | - Orson L Moritz
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - David S Williams
- Department of Ophthalmology and Jules Stein Eye Institute, Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA
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Qin S. Blockade of MerTK Activation by AMPK Inhibits RPE Cell Phagocytosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:773-8. [PMID: 26427488 DOI: 10.1007/978-3-319-17121-0_103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Timely removal of shed photoreceptor outer segments by retinal pigment epithelial cells (RPE) plays a key role in biological renewal of these highly peroxidizable structures and in maintenance of retina health. How environmental stress cause RPE cell dysfunction is undefined however. AMP-activated protein kinase (AMPK), a heterotrimer of a catalytic α subunit and regulatory β and γ subunits, maintains energy homeostasis by limiting energy utilization and/or promoting energy production when energy supply is compromised. Intriguingly, AMPK has been shown to be important in functions of RPE cells. In this mini-review, the role and mechanisms of AMPK in controlling RPE cell phagocytosis are discussed.
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Affiliation(s)
- Suofu Qin
- Retinal Disease Research, Department of Biological Sciences, Allergan, Inc., RD3-2D, 92612, Irvine, CA, USA.
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Moreira EF, Cai H, Tezel TH, Fields MA, Del Priore LV. Reengineering Human Bruch's Membrane Increases Rod Outer Segment Phagocytosis by Human Retinal Pigment Epithelium. Transl Vis Sci Technol 2015; 4:10. [PMID: 26557417 DOI: 10.1167/tvst.4.5.10] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 08/14/2015] [Indexed: 12/21/2022] Open
Abstract
PURPOSE We have shown previously that Bruch's membrane (BM) aging decreases retinal pigment epithelium (RPE) phagocytosis. Herein, we determine the effects of BM reengineering on RPE phagocytosis. METHODS BM explants were dissected from young and old donor eyes. Some old BM explants were reengineered by cleaning with Triton X-100 and/or coating with extracellular matrix (ECM) ligands. ARPE-19 cell-derived ECM (ARPE-ECM) modified ("aged") by sodium nitrite was subjected to similar treatments. ARPE-19 cells were then cultured to confluence onto the different surfaces. Fluorescently-labeled bovine rod outer segments (ROS) were fed to cells with or without αVβ5 integrin antibody. Image acquisition and phagocytosis quantification was performed by fluorescence microscopy and ImageJ analysis. RESULTS Cleaning old donor-derived BM with detergent does not increase the uptake of ROS, but a combination of cleaning and coating with ECM ligands significantly increases RPE phagocytosis (54.9 ± 6.2 vs. 83.5 ± 6.5 arbitrary units; P < 0.05) to levels closer to young donor BM (123.6 ± 9.9 arbitrary units). Similar effects were observed on nitrite-modified ARPE-ECM subjected to the same treatments. Incubation of αVβ5 blocking antibody with ROS significantly decreased RPE phagocytosis. CONCLUSIONS The detrimental effects of aging BM on RPE phagocytosis can be reversed by reengineering the BM surface with detergent cleaning and recoating with ECM ligands. TRANSLATION RELEVANCE These results demonstrate that the therapeutic success of transplanted RPE cells may require, at least in part, reengineering of diseased BM to make it a more suitable environment for attachment, survival and proper functioning of the RPE.
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Affiliation(s)
- Ernesto F Moreira
- Department of Ophthalmology Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Hui Cai
- Department of Ophthalmology, Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Tongalp H Tezel
- Department of Ophthalmology, Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Mark A Fields
- Department of Ophthalmology Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Lucian V Del Priore
- Department of Ophthalmology Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
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El-Asrag M, Sergouniotis P, McKibbin M, Plagnol V, Sheridan E, Waseem N, Abdelhamed Z, McKeefry D, Van Schil K, Poulter J, Johnson CA, Carr IM, Leroy BP, De Baere E, Inglehearn CF, Webster AR, Toomes C, Ali M, Black G, Hall G, Ingram S, Gillespie R, Ramsden S, Manson F, Hardcastle A, Michaelides M, Cheetham M, Arno G, Thomas N, Bhattacharya S, Moore T, Nemeth A, Downes S, Lise S, Lord E. Biallelic mutations in the autophagy regulator DRAM2 cause retinal dystrophy with early macular involvement. Am J Hum Genet 2015; 96:948-54. [PMID: 25983245 DOI: 10.1016/j.ajhg.2015.04.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 04/13/2015] [Indexed: 01/08/2023] Open
Abstract
Retinal dystrophies are an overlapping group of genetically heterogeneous conditions resulting from mutations in more than 250 genes. Here we describe five families affected by an adult-onset retinal dystrophy with early macular involvement and associated central visual loss in the third or fourth decade of life. Affected individuals were found to harbor disease-causing variants in DRAM2 (DNA-damage regulated autophagy modulator protein 2). Homozygosity mapping and exome sequencing in a large, consanguineous British family of Pakistani origin revealed a homozygous frameshift variant (c.140delG [p.Gly47Valfs(∗)3]) in nine affected family members. Sanger sequencing of DRAM2 in 322 unrelated probands with retinal dystrophy revealed one European subject with compound heterozygous DRAM2 changes (c.494G>A [p.Trp165(∗)] and c.131G>A [p.Ser44Asn]). Inspection of previously generated exome sequencing data in unsolved retinal dystrophy cases identified a homozygous variant in an individual of Indian origin (c.64_66del [p.Ala22del]). Independently, a gene-based case-control association study was conducted via an exome sequencing dataset of 18 phenotypically similar case subjects and 1,917 control subjects. Using a recessive model and a binomial test for rare, presumed biallelic, variants, we found DRAM2 to be the most statistically enriched gene; one subject was a homozygote (c.362A>T [p.His121Leu]) and another a compound heterozygote (c.79T>C [p.Tyr27His] and c.217_225del [p.Val73_Tyr75del]). DRAM2 encodes a transmembrane lysosomal protein thought to play a role in the initiation of autophagy. Immunohistochemical analysis showed DRAM2 localization to photoreceptor inner segments and to the apical surface of retinal pigment epithelial cells where it might be involved in the process of photoreceptor renewal and recycling to preserve visual function.
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Chaker L, Buitendijk GHS, Dehghan A, Medici M, Hofman A, Vingerling JR, Franco OH, Klaver CCW, Peeters RP. Thyroid function and age-related macular degeneration: a prospective population-based cohort study--the Rotterdam Study. BMC Med 2015; 13:94. [PMID: 25903050 PMCID: PMC4407352 DOI: 10.1186/s12916-015-0329-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 03/17/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND In animal models, lack of thyroid hormone is associated with cone photoreceptor preservation, while administration of high doses of active thyroid hormone leads to deterioration. The association between thyroid function and age-related macular degeneration (AMD) has not been investigated in the general population. METHODS Participants of age ≥ 55 years from the Rotterdam Study with thyroid-stimulating hormone (TSH) and/or free thyroxine (FT4) measurements and AMD assessment were included. We conducted age- and sex-adjusted Cox proportional hazards models to explore the association of TSH or FT4 with AMD, in the full range and in those with TSH (0.4-4.0 mIU/L) and/or FT4 in normal range (11-25 pmol/L). Cox proportional hazards models were performed for the association of TSH or FT4 with retinal pigment alterations (RPA), as an early marker of retinal changes. Multivariable models additionally included cardiovascular risk factors and thyroid peroxidase antibodies positivity. We also performed stratification by age and sex. A bidirectional look-up in genome-wide association study (GWAS) data for thyroid parameters and AMD was performed. Single nucleotide polymorphisms (SNPs) that are significantly associated with both phenotypes were identified. RESULTS We included 5,573 participants with a median follow-up of 6.9 years (interquartile range 4.4-10.8 years). During follow-up 805 people developed AMD. TSH levels were not associated with increased risk of AMD. Within normal range of FT4, participants in the highest FT4 quintile had a 1.34-fold increased risk of developing AMD, compared to individuals in the middle group (95% confidence interval [CI] 1.07-1.66). Higher FT4 values in the full range were associated with a higher risk of AMD (hazard ratio 1.04, CI, 1.01-1.06 per 1 pmol/L increase). Higher FT4 levels were similarly associated with a higher risk of RPA. Restricting analyses to euthyroid individuals, additional multivariable models, and stratification did not change estimates. We found a SNP (rs943080) in the VEGF-A gene, associated with AMD, to be significant in the TSH GWAS (P = 1.2 x 10(-4)). Adding this SNP to multivariable models did not change estimates. CONCLUSIONS Higher FT4 values are associated with increased risk of AMD - even in euthyroid individuals - and increased risk of RPA. Our data suggest an important role of thyroid hormone in pathways leading to AMD.
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Affiliation(s)
- Layal Chaker
- Rotterdam Thyroid Center, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | | | - Abbas Dehghan
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Marco Medici
- Rotterdam Thyroid Center, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Albert Hofman
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Johannes R Vingerling
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Oscar H Franco
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Caroline C W Klaver
- Department of Epidemiology, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, The Netherlands.
| | - Robin P Peeters
- Rotterdam Thyroid Center, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands. .,Department of Internal Medicine, Rotterdam Thyroid Center, Erasmus University Medical Center, Endocrinology, Erasmus University Medical Center Rotterdam, Room Ee502, PO Box 2040, 3000, CA, Rotterdam, The Netherlands.
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45
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Affiliation(s)
- Steven J Fliesler
- Departments of Ophthalmology and Biochemistry, University at Buffalo-The State University of New York (SUNY); the SUNY Eye Institute; and the Research Service, Veterans Administration Western New York Healthcare System (VAWNYHS), Buffalo, NY 14215
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Sharma K, Sharma NK, Anand A. Why AMD is a disease of ageing and not of development: mechanisms and insights. Front Aging Neurosci 2014; 6:151. [PMID: 25071560 PMCID: PMC4091411 DOI: 10.3389/fnagi.2014.00151] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 06/17/2014] [Indexed: 02/03/2023] Open
Abstract
Ageing disorders can be defined as the progressive and cumulative outcome of several defective cellular mechanisms as well as metabolic pathways, consequently resulting in degeneration. Environment plays an important role in its pathogenesis. In contrast, developmental disorders arise from inherited mutations and usually the role of environmental factors in development of disease is minimal. Age related macular degeneration (AMD) is one such retinal degenerative disorder which starts with the progression of age. Metabolism plays an important role in initiation of such diseases of ageing. Cholesterol metabolism and their oxidized products like 7-ketocholesterol have been shown to adversely impact retinal pigment epithelium (RPE) cells. These molecules can initiate mitochondrial apoptotic processes and also influence the complements factors and expression of angiogenic proteins like VEGF etc. In this review we highlight why and how AMD is an ageing disorder and not a developmental disease substantiated by disrupted cholesterol metabolism common to several age related diseases.
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Affiliation(s)
- Kaushal Sharma
- Neuroscience Research Lab, Department of Neurology, Post Graduate Institute of Medical Education and Research Chandigarh, India
| | - Neel Kamal Sharma
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute Bethesda, MD, USA
| | - Akshay Anand
- Neuroscience Research Lab, Department of Neurology, Post Graduate Institute of Medical Education and Research Chandigarh, India
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Moskova-Doumanova V, Pankov R, Lalchev Z, Doumanov J. Best1 Shot Through the Eye—Structure, Functions and Clinical Implications of Bestrophin-1 Protein. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.5504/bbeq.2012.0124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Giannaccini M, Giannini M, Calatayud MP, Goya GF, Cuschieri A, Dente L, Raffa V. Magnetic nanoparticles as intraocular drug delivery system to target retinal pigmented epithelium (RPE). Int J Mol Sci 2014; 15:1590-605. [PMID: 24451140 PMCID: PMC3907888 DOI: 10.3390/ijms15011590] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 02/07/2023] Open
Abstract
One of the most challenging efforts in drug delivery is the targeting of the eye. The eye structure and barriers render this organ poorly permeable to drugs. Quite recently the entrance of nanoscience in ocular drug delivery has improved the penetration and half-life of drugs, especially in the anterior eye chamber, while targeting the posterior chamber is still an open issue. The retina and the retinal pigment epithelium/choroid tissues, located in the posterior eye chamber, are responsible for the majority of blindness both in childhood and adulthood. In the present study, we used magnetic nanoparticles (MNPs) as a nanotool for ocular drug delivery that is capable of specific localization in the retinal pigmented epithelium (RPE) layer. We demonstrate that, following intraocular injection in Xenopus embryos, MNPs localize specifically in RPE where they are retained for several days. The specificity of the localization did not depend on particle size and surface properties of the MNPs used in this work. Moreover, through similar experiments in zebrafish, we demonstrated that the targeting of RPE by the nanoparticles is not specific for the Xenopus species.
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Affiliation(s)
- Martina Giannaccini
- Institute of Life Science, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, Pisa 56127, Italy.
| | - Marianna Giannini
- Institute of Life Science, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, Pisa 56127, Italy.
| | - M Pilar Calatayud
- Instituto de Nanociencia de Aragon & Condensed Matter Physics Department, Universidad de Zaragoza, Mariano Esquillor edif. I+D, Zaragoza 50018, Spain.
| | - Gerardo F Goya
- Instituto de Nanociencia de Aragon & Condensed Matter Physics Department, Universidad de Zaragoza, Mariano Esquillor edif. I+D, Zaragoza 50018, Spain.
| | - Alfred Cuschieri
- Institute of Life Science, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, Pisa 56127, Italy.
| | - Luciana Dente
- Department of Biology, Università di Pisa, S.S. 12 Abetone e Brennero 4, Pisa 56127, Italy.
| | - Vittoria Raffa
- Department of Biology, Università di Pisa, S.S. 12 Abetone e Brennero 4, Pisa 56127, Italy.
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Petrs-Silva H, Linden R. Advances in gene therapy technologies to treat retinitis pigmentosa. Clin Ophthalmol 2013; 8:127-36. [PMID: 24391438 PMCID: PMC3878960 DOI: 10.2147/opth.s38041] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Retinitis pigmentosa (RP) is a class of diseases that leads to progressive degeneration of the retina. Experimental approaches to gene therapy for the treatment of inherited retinal dystrophies have advanced in recent years, inclusive of the safe delivery of genes to the human retina. This review is focused on the development of gene therapy for RP using recombinant adenoassociated viral vectors, which show a positive safety record and have so far been successful in several clinical trials for congenital retinal disease. Gene therapy for RP is under development in a variety of animal models, and the results raise expectations of future clinical application. Nonetheless, the translation of such strategies to the bedside requires further understanding of the mutations and mechanisms that cause visual defects, as well as thorough examination of potential adverse effects.
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Affiliation(s)
- Hilda Petrs-Silva
- Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Linden
- Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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50
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Pasquay C, Wang LF, Lorenz B, Preising MN. Bestrophin 1 – Phenotypes and Functional Aspects in Bestrophinopathies. Ophthalmic Genet 2013; 36:193-212. [DOI: 10.3109/13816810.2013.863945] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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