1
|
Dontsov A, Ostrovsky M. Retinal Pigment Epithelium Pigment Granules: Norms, Age Relations and Pathology. Int J Mol Sci 2024; 25:3609. [PMID: 38612421 PMCID: PMC11011557 DOI: 10.3390/ijms25073609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024] Open
Abstract
The retinal pigment epithelium (RPE), which ensures the normal functioning of the neural retina, is a pigmented single-cell layer that separates the retina from the Bruch's membrane and the choroid. There are three main types of pigment granules in the RPE cells of the human eye: lipofuscin granules (LG) containing the fluorescent "age pigment" lipofuscin, melanoprotein granules (melanosomes, melanolysosomes) containing the screening pigment melanin and complex melanolipofuscin granules (MLG) containing both types of pigments simultaneously-melanin and lipofuscin. This review examines the functional role of pigment granules in the aging process and in the development of oxidative stress and associated pathologies in RPE cells. The focus is on the process of light-induced oxidative degradation of pigment granules caused by reactive oxygen species. The reasons leading to increased oxidative stress in RPE cells as a result of the oxidative degradation of pigment granules are considered. A mechanism is proposed to explain the phenomenon of age-related decline in melanin content in RPE cells. The essence of the mechanism is that when the lipofuscin part of the melanolipofuscin granule is exposed to light, reactive oxygen species are formed, which destroy the melanin part. As more melanolipofuscin granules are formed with age and the development of degenerative diseases, the melanin in pigmented epithelial cells ultimately disappears.
Collapse
Affiliation(s)
| | - Mikhail Ostrovsky
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 119334, Russia;
| |
Collapse
|
2
|
Dontsov AE, Yakovleva MA, Vasin AA, Gulin AA, Aybush AV, Nadtochenko VA, Ostrovsky MA. Understanding the Mechanism of Light-Induced Age-Related Decrease in Melanin Concentration in Retinal Pigment Epithelium Cells. Int J Mol Sci 2023; 24:13099. [PMID: 37685907 PMCID: PMC10487480 DOI: 10.3390/ijms241713099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/13/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023] Open
Abstract
It is known that during the process of aging, there is a significant decrease in the number of melanosomes in the retinal pigment epithelium (RPE) cells in the human eye. Melanosomes act as screening pigments in RPE cells and are fundamentally important for protection against the free radicals generated by light. A loss or change in the quality of melanin in melanosomes can lead to the development of senile pathologies and aggravation in the development of various retinal diseases. We have previously shown that the interaction between melanin melanosomes and superoxide radicals results in oxidative degradation with the formation of water-soluble fluorescent products. In the present study, we show, using fluorescence analysis, HPLC, and mass spectrometry, that visible light irradiation on melanolipofuscin granules isolated from RPE cells in the human eye results in the formation of water-soluble fluorescent products from oxidative degradation of melanin, which was in contrast to lipofuscin granules and melanosomes irradiation. The formation of these products occurs as a result of the oxidative degradation of melanin by superoxide radicals, which are generated by the lipofuscin part of the melanolipofuscin granule. We identified these products both in the composition of melanolipofuscin granules irradiated with visible light and in the composition of melanosomes that were not irradiated but were, instead, oxidized by superoxide radicals. In the melanolipofuscin granules irradiated by visible light, ions that could be associated with melanin oxidative degradation products were identified by applying the principal component analysis of the time-of-flight secondary ion mass spectrometry (ToF-SIMS) data. Degradation of the intact melanosomes by visible light is also possible; however, this requires significantly higher irradiation intensities than for melanolipofuscin granules. It is concluded that the decrease in the concentration of melanin in RPE cells in the human eye with age is due to its oxidative degradation by reactive oxygen species generated by lipofuscin, as part of the melanolipofuscin granules, under the action of light.
Collapse
Affiliation(s)
- Alexander E. Dontsov
- Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia; (M.A.Y.); (M.A.O.)
| | - Marina A. Yakovleva
- Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia; (M.A.Y.); (M.A.O.)
| | - Alexander A. Vasin
- Federal Research Center of Chemical Physics, Russian Academy of Sciences, N.N. Semenov RAS, 119991 Moscow, Russia; (A.A.V.); (A.A.G.); (A.V.A.); (V.A.N.)
| | - Alexander A. Gulin
- Federal Research Center of Chemical Physics, Russian Academy of Sciences, N.N. Semenov RAS, 119991 Moscow, Russia; (A.A.V.); (A.A.G.); (A.V.A.); (V.A.N.)
| | - Arseny V. Aybush
- Federal Research Center of Chemical Physics, Russian Academy of Sciences, N.N. Semenov RAS, 119991 Moscow, Russia; (A.A.V.); (A.A.G.); (A.V.A.); (V.A.N.)
| | - Viktor A. Nadtochenko
- Federal Research Center of Chemical Physics, Russian Academy of Sciences, N.N. Semenov RAS, 119991 Moscow, Russia; (A.A.V.); (A.A.G.); (A.V.A.); (V.A.N.)
| | - Mikhail A. Ostrovsky
- Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia; (M.A.Y.); (M.A.O.)
| |
Collapse
|
3
|
Abstract
Long-term use of hydroxychloroquine can cause retinopathy, which may result in severe and progressive visual loss. In the past decade, hydroxychloroquine use has markedly increased and modern retinal imaging techniques have enabled the detection of early, pre-symptomatic disease. As a consequence, the prevalence of retinal toxicity in long-term hydroxychloroquine users is known to be higher than was previously estimated. The pathophysiology of the retinopathy is incompletely characterised, although significant advances have been made in understanding the disease from clinical imaging studies. Hydroxychloroquine retinopathy elicits sufficient public health concern to justify the implementation of retinopathy screening programs for patients at risk. Here, we describe the historical background of hydroxychloroquine retinopathy and summarize its current understanding. We review the utility and limitations of each of the mainstream diagnostic tests used to detect hydroxychloroquine retinopathy. The key considerations towards a consensus on the definition of hydroxychloroquine retinopathy are outlined in the context of what is known of the natural history of the disease. We compare the current screening recommendations for hydroxychloroquine retinopathy, identifying where additional evidence is required, and the management of proven cases of toxicity. Finally, we highlight the areas for further investigation, which may further reduce the risk of visual loss in hydroxychloroquine users.
Collapse
Affiliation(s)
- Imran H. Yusuf
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Peter Charbel Issa
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Seong Joon Ahn
- Department of Ophthalmology, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, South Korea
| |
Collapse
|
4
|
Yang YP, Hsiao YJ, Chang KJ, Foustine S, Ko YL, Tsai YC, Tai HY, Ko YC, Chiou SH, Lin TC, Chen SJ, Chien Y, Hwang DK. Pluripotent Stem Cells in Clinical Cell Transplantation: Focusing on Induced Pluripotent Stem Cell-Derived RPE Cell Therapy in Age-Related Macular Degeneration. Int J Mol Sci 2022; 23:ijms232213794. [PMID: 36430270 PMCID: PMC9696562 DOI: 10.3390/ijms232213794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022] Open
Abstract
Human pluripotent stem cells (PSCs), including both embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), represent valuable cell sources to replace diseased or injured tissues in regenerative medicine. iPSCs exhibit the potential for indefinite self-renewal and differentiation into various cell types and can be reprogrammed from somatic tissue that can be easily obtained, paving the way for cell therapy, regenerative medicine, and personalized medicine. Cell therapies using various iPSC-derived cell types are now evolving rapidly for the treatment of clinical diseases, including Parkinson's disease, hematological diseases, cardiomyopathy, osteoarthritis, and retinal diseases. Since the first interventional clinical trial with autologous iPSC-derived retinal pigment epithelial cells (RPEs) for the treatment of age-related macular degeneration (AMD) was accomplished in Japan, several preclinical trials using iPSC suspensions or monolayers have been launched, or are ongoing or completed. The evolution and generation of human leukocyte antigen (HLA)-universal iPSCs may facilitate the clinical application of iPSC-based therapies. Thus, iPSCs hold great promise in the treatment of multiple retinal diseases. The efficacy and adverse effects of iPSC-based retinal therapies should be carefully assessed in ongoing and further clinical trials.
Collapse
Affiliation(s)
- Yi-Ping Yang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Yu-Jer Hsiao
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Kao-Jung Chang
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Shania Foustine
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Yu-Ling Ko
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Yi-Ching Tsai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Hsiao-Yun Tai
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Yu-Chieh Ko
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Shih-Hwa Chiou
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Genomics Research Center, Academia Sinica, Taipei 115201, Taiwan
| | - Tai-Chi Lin
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan
| | - Yueh Chien
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Institute of Pharmacology, College of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Correspondence: (Y.C.); (D.-K.H.); Tel.: +886-2-2875-2121 (D.-K.H.)
| | - De-Kuang Hwang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 112201, Taiwan
- Correspondence: (Y.C.); (D.-K.H.); Tel.: +886-2-2875-2121 (D.-K.H.)
| |
Collapse
|
5
|
Fantaguzzi F, Zucchiatti I, Sacconi R, Bux AV, Prascina F, Bandello F, Querques G. Bilateral asymptomatic macular hypopigmentation in a young woman: multimodal imaging and pathogenetic hypothesis. Am J Ophthalmol Case Rep 2022; 28:101725. [PMCID: PMC9589140 DOI: 10.1016/j.ajoc.2022.101725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/06/2022] [Accepted: 10/09/2022] [Indexed: 11/25/2022] Open
Abstract
Purpose Observations Conclusions
Collapse
Affiliation(s)
- Federico Fantaguzzi
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele, Milan, Italy
| | - Ilaria Zucchiatti
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele, Milan, Italy
| | - Riccardo Sacconi
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele, Milan, Italy
| | - Anna Valeria Bux
- Department of Ophthalmology, University of Foggia, Foggia, Italy
| | - Francesco Prascina
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele, Milan, Italy
| | - Giuseppe Querques
- Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele, Milan, Italy,Corresponding author.
| |
Collapse
|
6
|
Pandey RS, Krebs MP, Bolisetty MT, Charette JR, Naggert JK, Robson P, Nishina PM, Carter GW. Single-Cell RNA Sequencing Reveals Molecular Features of Heterogeneity in the Murine Retinal Pigment Epithelium. Int J Mol Sci 2022; 23:ijms231810419. [PMID: 36142331 PMCID: PMC9499471 DOI: 10.3390/ijms231810419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 08/09/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
Transcriptomic analysis of the mammalian retinal pigment epithelium (RPE) aims to identify cellular networks that influence ocular development, maintenance, function, and disease. However, available evidence points to RPE cell heterogeneity within native tissue, which adds complexity to global transcriptomic analysis. Here, to assess cell heterogeneity, we performed single-cell RNA sequencing of RPE cells from two young adult male C57BL/6J mice. Following quality control to ensure robust transcript identification limited to cell singlets, we detected 13,858 transcripts among 2667 and 2846 RPE cells. Dimensional reduction by principal component analysis and uniform manifold approximation and projection revealed six distinct cell populations. All clusters expressed transcripts typical of RPE cells; the smallest (C1, containing 1–2% of total cells) exhibited the hallmarks of stem and/or progenitor (SP) cells. Placing C1–6 along a pseudotime axis suggested a relative decrease in melanogenesis and SP gene expression and a corresponding increase in visual cycle gene expression upon RPE maturation. K-means clustering of all detected transcripts identified additional expression patterns that may advance the understanding of RPE SP cell maintenance and the evolution of cellular metabolic networks during development. This work provides new insights into the transcriptome of the mouse RPE and a baseline for identifying experimentally induced transcriptional changes in future studies of this tissue.
Collapse
Affiliation(s)
- Ravi S. Pandey
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Dr., Farmington, CT 06032, USA
| | - Mark P. Krebs
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
| | - Mohan T. Bolisetty
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Dr., Farmington, CT 06032, USA
| | | | | | - Paul Robson
- The Jackson Laboratory for Genomic Medicine, 10 Discovery Dr., Farmington, CT 06032, USA
| | - Patsy M. Nishina
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
- Correspondence: (P.M.N.); (G.W.C.)
| | - Gregory W. Carter
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
- Correspondence: (P.M.N.); (G.W.C.)
| |
Collapse
|
7
|
Feldman TB, Dontsov AE, Yakovleva MA, Ostrovsky MA. Photobiology of lipofuscin granules in the retinal pigment epithelium cells of the eye: norm, pathology, age. Biophys Rev 2022; 14:1051-1065. [PMID: 36124271 PMCID: PMC9481861 DOI: 10.1007/s12551-022-00989-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/26/2022] [Indexed: 01/10/2023] Open
Abstract
Lipofuscin granules (LGs) are accumulated in the retinal pigment epithelium (RPE) cells. The progressive LG accumulation can somehow lead to pathology and accelerate the aging process. The review examines composition, spectral properties and photoactivity of LGs isolated from the human cadaver eyes. By use of atomic force microscopy and near-field microscopy, we have revealed the fluorescent heterogeneity of LGs. We have discovered the generation of reactive oxygen species by LGs, and found that LGs and melanolipofuscin granules are capable of photoinduced oxidation of lipids. It was shown that A2E, as the main fluorophore (bisretinoid) of LGs, is much less active as an oxidation photosensitizer than other fluorophores (bisretinoids) of LGs. Photooxidized products of bisretinoids pose a much greater danger to the cell than non-oxidized one. Our studies of the fluorescent properties of LGs and their fluorophores (bisretinoids) showed for the first time that their spectral characteristics change (shift to the short-wavelength region) in pathology and after exposure to ionizing radiation. By recording the fluorescence spectra and fluorescence decay kinetics of oxidized products of LG fluorophores, it is possible to improve the methods of early diagnosis of degenerative diseases. Lipofuscin ("aging pigment") is not an inert "slag". The photoactivity of LGs can pose a significant danger to the RPE cells. Fluorescence characteristics of LGs are a tool to detect early stages of degeneration in the retina and RPE.
Collapse
Affiliation(s)
- T. B. Feldman
- Department of Biology, Lomonosov Moscow State University, Moscow, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - A. E. Dontsov
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - M. A. Yakovleva
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - M. A. Ostrovsky
- Department of Biology, Lomonosov Moscow State University, Moscow, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
8
|
Marín-sanhueza C, Echeverría-vega A, Gómez A, Cabrera-barjas G, Romero R, Banerjee A. Stress Dependent Biofilm Formation and Bioactive Melanin Pigment Production by a Thermophilic Bacillus Species from Chilean Hot Spring. Polymers (Basel) 2022; 14:680. [PMID: 35215592 PMCID: PMC8880475 DOI: 10.3390/polym14040680] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/05/2022] [Accepted: 02/07/2022] [Indexed: 12/02/2022] Open
Abstract
Thermophilic bacteria able to survive extreme temperature stress are of great biotechnological interest due to their extracellular production of bioactive molecules as a part of a survival strategy, or by intracellular modifications. In the present study, thermophilic Bacillus haynesii CamB6, isolated from a Chilean hot spring, was studied for the formation of different stress response molecules. The polymeric pigment produced by the bacterial strain was characterized by different physicochemical techniques. On exposure to ranges of temperature (50–60 °C), pH (5.0–7.0), and sources of nitrogen and carbon (1–5 g·L−1), the bacteria responded with a biofilm network formation in a hydrophobic polystyrene surface. Biofilm formation under fed-batch conditions was also statistically validated. The bacteria showed a planktonic pellicle network formation in the presence of induced hypoxia and salinity stress (19.45 g·L−1) under static conditions. Salinity stress also resulted in the intracellular response of brown pigment production. The pigment was structurally and functionally characterized by UV-Vis absorbance and the presence of different characteristic peaks via FTIR analysis (bacterial pyomelanin fingerprints) were assessed. A high thermal stability and TGA profile indicated the brown pigment was a probable pyomelanin candidate. Micropyrolysis (Py-GC/MS) showed that isoprene, pyrrole, benzene, pyridine, and their derivatives were the major components detected. In addition, acetic acid, indole, phenol, and its derivatives were observed. The absence of sulfocompounds in the pyrolyzed products agreed with those reported in the literature for pyomelanin. The pigment surface morphology was analyzed via SEM, and the elemental composition via EDS also demonstrated the similarity of the brown pigment to that of the melanin family. The pyomelanin pigment was observed to be bioactive with promising antioxidant capacity (H2O2, Fe2+) compared to the standard antioxidant molecules. In conclusion, B. haynesii CamB6 demonstrated the formation of several biomolecules as a stress response mechanism that is bioactive, showing its probable biotechnological applications in future.
Collapse
|
9
|
Kim JH, Kim MM. The relationship between melanin production and lipofuscin formation in Tyrosinase gene knockout melanocytes using CRISPR/Cas9 system. Life Sci 2021; 284:119915. [PMID: 34453947 DOI: 10.1016/j.lfs.2021.119915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/02/2021] [Accepted: 08/14/2021] [Indexed: 10/20/2022]
Abstract
Age spots are a significant phenotypic marker of aging formed by lipofuscin. Melanin is another skin pigment molecule responsible for skin aging. The present study aims to investigate the relationship between melanin production and lipofuscin synthesis in normal mouse melanoma cell line B16F1 cells and Tyrosinase (TYR) gene knockout cells. TYR gene KO cells were successfully developed using CRISPR/Cas9 system and confirmed by Sanger DNA sequencing analysis. Furthermore, the melanin production and lipofuscin formation were validated through RT-PCR and Western blot analysis. The expression levels of gene microphthalmia-associated transcription factor (MITF), Tyrosinase, tyrosine-related protein-1 (TRP-1), tyrosine-related protein-2 (TRP-2), and antioxidant proteins such as methionine sulfoxide reductase A (MSRA), Catalase and Glutathione reductase (GR) related to melanogenesis was found to be decreased in TYR gene KO cells compared with normal cells. Moreover, lipofuscin formation was increased in TYR gene KO cells compared to normal cells. Therefore, the above findings suggest that melanin production and lipofuscin formation could be linked by the TYR gene in melanocytes.
Collapse
Affiliation(s)
- Jae Ho Kim
- Department of Applied Chemistry, Dong-Eui University, Busan 614-714, Republic of Korea
| | - Moon-Moo Kim
- Department of Applied Chemistry, Dong-Eui University, Busan 614-714, Republic of Korea.
| |
Collapse
|
10
|
Abstract
Light has a crucial role in the visual process. For nonvisible radiation in the short-wave spectrum, there are natural mechanisms that protect the human retina from damaging ultraviolet (UV) radiation. Here, the dose (= energy) makes the poison. Damage caused by UV light mainly affects the outer retina, particularly the photoreceptors and the retinal pigment epithelium. While retinal damage due to increased UV radiation exposure can potentially still occur up to the age of 20, in adulthood, exposure of the retina to UV radiation can no longer be assumed, due to decreasing transmission properties of the natural lens. The natural lens, modern intraocular lenses, and wearing of sunglasses with appropriate filter function, particularly in childhood and adolescence, provide a relevant reduction in UV radiation exposure of the retina.
Collapse
Affiliation(s)
| | - Thomas Ach
- Augenklinik, Universitätsklinikum Bonn, Venusberg-Campus 1, 53127, Bonn, Deutschland.
| |
Collapse
|
11
|
Meleppat RK, Ronning KE, Karlen SJ, Burns ME, Pugh EN Jr, Zawadzki RJ. In vivo multimodal retinal imaging of disease-related pigmentary changes in retinal pigment epithelium. Sci Rep 2021; 11:16252. [PMID: 34376700 DOI: 10.1038/s41598-021-95320-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/20/2021] [Indexed: 02/08/2023] Open
Abstract
Melanosomes, lipofuscin, and melanolipofuscin are the three principal types of pigmented granules found in retinal pigment epithelium (RPE) cells. Changes in the density of melanosomes and lipofuscin in RPE cells are considered hallmarks of various retinal diseases, including Stargardt disease and age-related macular degeneration (AMD). Herein, we report the potential of an in vivo multimodal imaging technique based on directional back-scattering and short-wavelength fundus autofluorescence (SW-FAF) to study disease-related changes in the density of melanosomes and lipofuscin granules in RPE cells. Changes in the concentration of these granules in Abca4−/− mice (a model of Stargardt disease) relative to age-matched wild-type (WT) controls were investigated. Directional optical coherence tomography (dOCT) was used to assess melanosome density in vivo, whereas the autofluorescence (AF) images and emission spectra acquired with a spectrometer-integrated scanning laser ophthalmoscope (SLO) were used to characterize lipofuscin and melanolipofuscin granules in the same RPE region. Subcellular-resolution ex vivo imaging using confocal fluorescence microscopy and electron microscopy was performed on the same tissue region to visualize and quantify melanosomes, lipofuscin, and melanolipofuscin granules. Comparisons between in vivo and ex vivo results confirmed an increased concentration of lipofuscin granules and decreased concentration of melanosomes in the RPE of Abca4−/− mice, and provided an explanation for the differences in fluorescence and directionality of RPE scattering observed in vivo between the two mouse strains.
Collapse
|
12
|
Meleppat RK, Ronning KE, Karlen SJ, Kothandath KK, Burns ME, Pugh EN, Zawadzki RJ. In Situ Morphologic and Spectral Characterization of Retinal Pigment Epithelium Organelles in Mice Using Multicolor Confocal Fluorescence Imaging. Invest Ophthalmol Vis Sci 2021; 61:1. [PMID: 33137194 PMCID: PMC7645167 DOI: 10.1167/iovs.61.13.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Purpose To investigate the major organelles of the retinal pigment epithelium (RPE) in wild-type (WT, control) mice and their changes in pigmented Abca4 knockout (Abca4−/−) mice with in situ morphologic, spatial, and spectral characterization of live ex vivo flat-mounted RPE using multicolor confocal fluorescence microscopy (MCFM). Methods In situ imaging of RPE flat-mounts of agouti Abca4−/− (129S4), agouti WT (129S1/SvlmJ) controls, and B6 albino mice (C57BL/6J-Tyrc-Brd) was performed with a Nikon A1 confocal microscope. High-resolution confocal image z-stacks of the RPE cell mosaic were acquired with four different excitation wavelengths (405 nm, 488 nm, 561 nm, and 640 nm). The autofluorescence images of RPE, including voxel-by-voxel emission spectra, were acquired and processed with Nikon NIS-AR Elements software. Results The 3-dimensional multicolor confocal images provided a detailed visualization of the RPE cell mosaic, including its melanosomes and lipofuscin granules, and their varying characteristics in the different mice strains. The autofluorescence spectra, spatial distribution, and morphologic features of melanosomes and lipofuscin granules were measured. Increased numbers of lipofuscin and reduced numbers of melanosomes were observed in the RPE of Abca4−/− mice relative to controls. Conclusions A detailed assessment of the RPE autofluorescent granules and their changes ex vivo was possible with MCFM. For all excitation wavelengths, autofluorescence from the RPE cells was predominantly contributed by lipofuscin granules, while melanosomes were found to be essentially nonfluorescent. The red shift of the emission peak confirmed the presence of multiple chromophores within lipofuscin granules. The elevated autofluorescence levels in Abca4−/− mice correlated well with the increased number of lipofuscin granules.
Collapse
Affiliation(s)
- Ratheesh K Meleppat
- UC Davis Eyepod Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, University of California Davis, Davis, California, United States
| | - Kaitryn E Ronning
- Center for Neuroscience, University of California Davis, Davis, California, United States
| | - Sarah J Karlen
- Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States
| | - Karuna K Kothandath
- UC Davis Eyepod Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, University of California Davis, Davis, California, United States
| | - Marie E Burns
- Department of Ophthalmology & Vision Science, University of California Davis, Davis, California, United States.,Center for Neuroscience, University of California Davis, Davis, California, United States.,Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States
| | - Edward N Pugh
- UC Davis Eyepod Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States.,Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States
| | - Robert J Zawadzki
- UC Davis Eyepod Imaging Laboratory, Department of Cell Biology and Human Anatomy, University of California Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, University of California Davis, Davis, California, United States
| |
Collapse
|
13
|
Navaratnam J, Salvanos P, Vavvas DG, Bragadóttir R. Ultra-widefield autofluorescence imaging findings in retinoschisis, rhegmatogenous retinal detachment and combined retinoschisis retinal detachment. Acta Ophthalmol 2021; 99:195-200. [PMID: 32602221 DOI: 10.1111/aos.14521] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 05/26/2020] [Indexed: 01/06/2023]
Abstract
PURPOSE Retinoschisis (RS), rhegmatogenous retinal detachment (RRD) and combined RS retinal detachment (RSRD) may resemble clinically and pose a diagnostic challenge. This study investigates the role of the fundus autofluorescence (AF) in differentiating RS, RRD and RSRD. METHODS Fundus AF changes of 34 eyes diagnosed with RRD, 30 eyes with RS and 12 eyes with RSRD were retrospectively analysed. Ultra-widefield AF (UW-AF) image intensities obtained with the Optomap 200Tx were interpreted as hypo-, hyper- and isoautofluorescent or a mixed pattern with hypo- and hyperautofluorescence over and at the posterior margin (PM) of RRD, RS and RSRD. RESULTS All RS eyes revealed isoautofluorescence over the area of RS, and nine eyes (30%) showed hypoautofluorescent PM. Among RRD, acute (≤2 weeks) and chronic (>2 weeks) RRD demonstrated distinct AF characteristics. Sixty-two per cent of RRD eyes had acute RRD. From those, 16 eyes (76%) demonstrated hypoautofluorescence over the detached area and 19 (90%) eyes with hyperautofluorescent PM. Sixty-two per cent of chronic RRD eyes demonstrated isoautofluorecence over the detached area. Eight RSRD eyes (67%) revealed hyperautofluorescence in the detached area. The positive predictive value (PPV) for hypoautofluorescence over the area of subretinal fluid (SRF) in RRD was 95%. The PPV for hyperautofluorescence over the area of SRF in RSRD was 100% and for isoautofluorescence for schitic area in RSRD and RS was 76%. CONCLUSION The UW-AF can be a useful non-invasive adjuvant tool to distinguish between RRD, RS and RSRD. Hypo- or hyperautofluorescence over the area of interest and hyperautofluorescent PM indicates the presence of SRF.
Collapse
Affiliation(s)
- Jesintha Navaratnam
- Department of Ophthalmology Oslo University Hospital Oslo Norway
- University of Oslo Oslo Norway
| | - Panagiotis Salvanos
- University of Oslo Oslo Norway
- Department of Ophthalmology Drammen Hospital Vestre Viken Hospital Trust Drammen Norway
| | - Demetrios G. Vavvas
- Department of Ophthalmology Retina Service Massachusetts Eye and Ear Infirmary Harvard Medical School Boston Massachusetts USA
| | - Ragnheiður Bragadóttir
- Department of Ophthalmology Oslo University Hospital Oslo Norway
- University of Oslo Oslo Norway
| |
Collapse
|
14
|
Miyagi S, Nishinaka A, Yamamoto T, Otsu W, Nakamura S, Shimazawa M, Kitaoka T, Hara H. Establishment of a pigmented murine model abundant with characteristics of retinal vein occlusion. Exp Eye Res 2021; 204:108441. [PMID: 33453278 DOI: 10.1016/j.exer.2021.108441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/21/2020] [Accepted: 01/06/2021] [Indexed: 02/07/2023]
Abstract
Retinal vein occlusion (RVO) is a vascular disease that represents characteristic retinal hemorrhage and dilated retinal veins. Despite its clinical importance, its pathogenesis remains largely unknown because of limited opportunities to acquire human retinal samples. Therefore, an animal model that reproduces the clinical features of RVO patients is required for further investigation. In this study, we established a pigmented murine RVO model that reproduced characteristic fundus appearances similar to human RVO findings. Retinal edema in this model was observed in both optical coherence tomography and histological analysis, which is a clinically important outcome. With quantitative real-time PCR analysis on retinal samples, we revealed that the mRNA level of vascular endothelial growth factor (VEGF) increased in the retina induced RVO. Moreover, this retinal edema was reduced by intravitreal injection of anti-VEGF antibody. These results were consistent with human clinical knowledge and suggested that this model could be a useful tool for research into new therapeutic approaches.
Collapse
|
15
|
Martinelli LP, Iermak I, Moriyama LT, Requena MB, Pires L, Kurachi C. Optical clearing agent increases effectiveness of photodynamic therapy in a mouse model of cutaneous melanoma: an analysis by Raman microspectroscopy. Biomed Opt Express 2020; 11:6516-6527. [PMID: 33282505 PMCID: PMC7687942 DOI: 10.1364/boe.405039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/24/2020] [Accepted: 10/12/2020] [Indexed: 05/05/2023]
Abstract
Melanoma is the most aggressive type of skin cancer and a relevant health problem due to its poor treatment response with high morbidity and mortality rates. This study, aimed to investigate the tissue changes of an improved photodynamic therapy (PDT) response when combined with optical clearing agent (OCA) in the treatment of cutaneous melanoma in mice. Photodithazine (PDZ) was administered intraperitoneally and a solution of OCA was topically applied before PDT irradiation. Due to a resultant refractive index matching, OCA-treated tumors are more optically homogenous, improving the PDT response. Raman analysis revealed, when combined with OCA, the PDT response was more homogenous down to 725 µm-depth in thickness.
Collapse
Affiliation(s)
- Letícia Palombo Martinelli
- Federal University of São Carlos, Post-Graduation Program inBiotechnology, Rodovia Washington Luís km 235, SP-310, São Carlos 13565-905, Brazil
- University of São Paulo, São Carlos Institute of Physics, Avenue Trabalhador São-Carlense, 400, São Carlos, São Paulo 13566-590, Brazil
| | - Ievgeniia Iermak
- University of São Paulo, São Carlos Institute of Physics, Avenue Trabalhador São-Carlense, 400, São Carlos, São Paulo 13566-590, Brazil
| | - Lilian Tan Moriyama
- University of São Paulo, São Carlos Institute of Physics, Avenue Trabalhador São-Carlense, 400, São Carlos, São Paulo 13566-590, Brazil
| | - Michelle Barreto Requena
- University of São Paulo, São Carlos Institute of Physics, Avenue Trabalhador São-Carlense, 400, São Carlos, São Paulo 13566-590, Brazil
| | - Layla Pires
- Princess Margaret Cancer Center, University Health Network, Princess Margaret Cancer Research Tower, 101 College Street, Toronto, Ontario M5G1L7, Canada
| | - Cristina Kurachi
- Federal University of São Carlos, Post-Graduation Program inBiotechnology, Rodovia Washington Luís km 235, SP-310, São Carlos 13565-905, Brazil
- University of São Paulo, São Carlos Institute of Physics, Avenue Trabalhador São-Carlense, 400, São Carlos, São Paulo 13566-590, Brazil
| |
Collapse
|
16
|
Abstract
PURPOSE To review the basic principles of ultra-widefield fundus autofluorescence (UWF-FAF) and discuss its clinical application for a variety of retinal and choroidal disorders. METHODS A systematic review of the PubMed database was performed using the search terms "ultra-widefield," "autofluorescence," "retinal disease" and "choroidal disease." RESULTS UWF-FAF imaging is a recently developed noninvasive retinal imaging modality with a wide imaging range that can locate peripheral fundus lesions that traditional fundus autofluorescence cannot. Multiple commercially available ultra-widefield imaging systems, including Heidelberg Spectralis and Optomap Ultra-Widefield systems, are available to the clinician. Imaging by UWF-FAF is more comprehensive; it can reflect the content and distribution of the predominant ocular fluorophore in retinal pigment epithelial cells and evaluate the metabolic status of RPE of various retinal and choroidal disorders. CONCLUSION UWF-FAF can detect abnormalities that traditional fundus autofluorescence cannot; therefore, it can be used to better elucidate disease pathogenesis, analyze genotype-phenotype correlations, diagnose and monitor disease.
Collapse
Affiliation(s)
- Amin Xu
- Department of Ophthalmology of Renmin Hospital of Wuhan University, No238, Jiefang Road, Wuhan, 430060, Hubei, China
| | - Changzheng Chen
- Department of Ophthalmology of Renmin Hospital of Wuhan University, No238, Jiefang Road, Wuhan, 430060, Hubei, China.
| |
Collapse
|
17
|
Sato M, Onuma K, Domon M, Hasegawa S, Suzuki A, Kusumi R, Hino R, Kakihara N, Kanda Y, Osaki M, Hamada J, Bannai S, Feederle R, Buday K, Angeli JPF, Proneth B, Conrad M, Okada F, Sato H. Loss of the cystine/glutamate antiporter in melanoma abrogates tumor metastasis and markedly increases survival rates of mice. Int J Cancer 2020; 147:3224-3235. [PMID: 32818320 DOI: 10.1002/ijc.33262] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 07/29/2020] [Accepted: 08/05/2020] [Indexed: 12/11/2022]
Abstract
The cystine/glutamate antiporter, system xc - , is essential for the efficient uptake of cystine into cells. Interest in the mechanisms of system xc - function soared with the recognition that system xc - presents the most upstream node of ferroptosis, a recently described form of regulated necrosis relevant for degenerative diseases and cancer. Since targeting system xc - hold the great potential to efficiently combat tumor growth and metastasis of certain tumors, we disrupted the substrate-specific subunit of system xc - , xCT (SLC7A11) in the highly metastatic mouse B16F10 melanoma cell line and assessed the impact on tumor growth and metastasis. Subcutaneous injection of tumor cells into the syngeneic B16F10 mouse melanoma model uncovered a marked decrease in the tumor-forming ability and growth of KO cells compared to control cell lines. Strikingly, the metastatic potential of KO cells was markedly reduced as shown in several in vivo models of experimental and spontaneous metastasis. Accordingly, survival rates of KO tumor-bearing mice were significantly prolonged in contrast to those transplanted with control cells. Analyzing the in vitro ability of KO and control B16F10 cells in terms of endothelial cell adhesion and spheroid formation revealed that xCT expression indeed plays an important role during metastasis. Hence, system xc - emerges to be essential for tumor metastasis in mice, thus qualifying as a highly attractive anticancer drug target, particularly in light of its dispensable role for normal life in mice.
Collapse
Affiliation(s)
- Mami Sato
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan.,Sakeology Center, Niigata University, Niigata, Japan.,Helmholtz Zentrum Muenchen, Institute of Metabolism and Cell Death, Neuherberg, Germany
| | - Kunishige Onuma
- Division of Experimental Pathology, Tottori University Faculty of Medicine, Yonago, Japan.,Department of Clinical Bio-resource Research and Development, Graduate School of Medicine Kyoto University, Kyoto, Japan
| | - Mio Domon
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Shun Hasegawa
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Ami Suzuki
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Ryosuke Kusumi
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Remi Hino
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Nahoko Kakihara
- Department of Nursing, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Yusuke Kanda
- Division of Experimental Pathology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Mitsuhiko Osaki
- Division of Experimental Pathology, Tottori University Faculty of Medicine, Yonago, Japan.,Chromosome Engineering Research Center, Tottori University, Yonago, Japan
| | - Junichi Hamada
- Health Sciences University of Hokkaido, School of Nursing and Social Services, Ishikari, Tobetsu, Japan
| | - Shiro Bannai
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Regina Feederle
- Helmholtz Zentrum Muenchen, Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Neuherberg, Germany
| | - Katalin Buday
- Helmholtz Zentrum Muenchen, Institute of Metabolism and Cell Death, Neuherberg, Germany
| | | | - Bettina Proneth
- Helmholtz Zentrum Muenchen, Institute of Metabolism and Cell Death, Neuherberg, Germany
| | - Marcus Conrad
- Helmholtz Zentrum Muenchen, Institute of Metabolism and Cell Death, Neuherberg, Germany.,National Research Medical University, Laboratory of Experimental Oncology, Moscow, Russia
| | - Futoshi Okada
- Division of Experimental Pathology, Tottori University Faculty of Medicine, Yonago, Japan.,Chromosome Engineering Research Center, Tottori University, Yonago, Japan
| | - Hideyo Sato
- Laboratory of Biochemistry and Molecular Biology, Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| |
Collapse
|
18
|
Oh JJ, Kim JY, Kwon SL, Hwang DH, Choi YE, Kim GH. Production and characterization of melanin pigments derived from Amorphotheca resinae. J Microbiol 2020; 58:648-656. [PMID: 32424578 DOI: 10.1007/s12275-020-0054-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 12/16/2022]
Abstract
As melanin has emerged as functional pigment with cosmetic, health and food applications, the demand for the pigments is expected to increase. However, the conventional sources (e.g. mushroom, hair, and wool) of melanin production entail pigments inside the substrates which requires the costly extraction procedures, leading to inappropriate scalable production. In this study, we screened 102 of fungal isolates for their ability to produce melanin in the supernatant and selected the only Amorphotheca resinae as a promising candidate. In the peptone yeast extract glucose broth, A. resinae produced the melanin rapidly during the autolysis phase of growth, reaching up 4.5 g/L within 14 days. Structural characterization of the purified melanin from A. resinae was carried out by using elemental analysis, electron paramagnetic resonance, 13C solid-state nuclear magnetic resonance spectroscopy, and pyrolysis-gas chromatography-mass spectrometry in comparison with the standard melanins. The results indicate that the structural properties of A. resinae melanin is similar to the eumelanin which has a wide range of industrial uses. For example, the purified melanin from A. resinae has the potent antioxidant activities as a result of free radical scavenging assays. Consequently, A. resinae KUC3009 can be a promising candidate for scalable production of industrially applicable melanin.
Collapse
Affiliation(s)
- Jeong-Joo Oh
- Division of Environmental Science & Ecological Engineering, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Jee Young Kim
- Division of Environmental Science & Ecological Engineering, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Sun Lul Kwon
- Division of Environmental Science & Ecological Engineering, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Dong-Hyeok Hwang
- Department of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Yoon-E Choi
- Division of Environmental Science & Ecological Engineering, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea
| | - Gyu-Hyeok Kim
- Division of Environmental Science & Ecological Engineering, College of Life Sciences & Biotechnology, Korea University, Seoul, 02841, Republic of Korea.
| |
Collapse
|
19
|
Markitantova YV, Simirskii VN. Role of the Redox System in Initiation of a Regenerative Response of Neural Eye Tissues in Vertebrates. Russ J Dev Biol 2020. [DOI: 10.1134/s106236042001004x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
20
|
Menghini M, Cehajic-Kapetanovic J, MacLaren RE. Monitoring progression of retinitis pigmentosa: current recommendations and recent advances. Expert Opin Orphan Drugs 2020; 8:67-78. [PMID: 32231889 PMCID: PMC7104334 DOI: 10.1080/21678707.2020.1735352] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/24/2020] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Retinitis pigmentosa (RP) is the most common form of inherited retinal degenerations with an estimated prevalence of 1 in 4,000 and more than 1 million individuals affected worldwide. With the introduction of the first retinal gene therapy in 2017 the importance of understanding the mechanisms of retinal degeneration and its natural progression has shifted from being of academic interest to being of pivotal for the development of new therapies. AREAS COVERED This review covers standard and innovative diagnostic techniques and complementary examinations needed for the evaluation and treatment of RP. It includes chapters on the assessment of visual function, retinal morphology, and genotyping. EXPERT OPINION Monitoring the progression of RP can best be achieved by combining assessments of both visual function and morphology. Visual acuity testing using ETDRS charts should be complemented by low-luminance visual acuity and colour vision tests. Assessment of the visual field can also be useful in less advanced cases. In those with central RP involvement measuring retinal sensitivity using microperimetry is recommended. Retinal morphology is best assessed by OCT and autofluorescence. Genetic testing is pivotal as it contributes to the pathophysiological understanding and can guide clinical management as well as identify individuals that could benefit from retinal gene therapy.
Collapse
Affiliation(s)
- Moreno Menghini
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, Oxford University, The John Radcliffe Hospital, West Wing, Oxford OX3 9DU, United Kingdom, +41 79 704 52 58
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, Oxford University, The John Radcliffe Hospital, West Wing, Oxford OX3 9DU, United Kingdom, +44 7725 197054
| | - Robert E MacLaren
- Oxford Eye Hospital and Nuffield Department of Clinical Neurosciences, Oxford University, The John Radcliffe Hospital, West Wing, Oxford OX3 9DU, United Kingdom, +44 1865 228974
| |
Collapse
|
21
|
Fang Y, Tschulakow A, Taubitz T, Illing B, Biesemeier A, Julien-Schraermeyer S, Radu RA, Jiang Z, Schraermeyer U. Fundus autofluorescence, spectral-domain optical coherence tomography, and histology correlations in a Stargardt disease mouse model. FASEB J 2020; 34:3693-3714. [PMID: 31989709 DOI: 10.1096/fj.201901784rr] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 01/09/2023]
Abstract
Stargardt disease (STGD1), known as inherited retinal dystrophy, is caused by ABCA4 mutations. The pigmented Abca4-/- mouse strain only reflects the early stage of STGD1 since it is devoid of retinal degeneration. This blue light-illuminated pigmented Abca4-/- mouse model presented retinal pigment epithelium (RPE) and photoreceptor degeneration which was similar to the advanced STGD1 phenotype. In contrast, wild-type mice showed no RPE degeneration after blue light illumination. In Abca4-/- mice, the acute blue light diminished the mean autofluorescence (AF) intensity in both fundus short-wavelength autofluorescence (SW-AF) and near-infrared autofluorescence (NIR-AF) modalities correlating with reduced levels of bisretinoid-fluorophores. Blue light-induced RPE cellular damage preceded the photoreceptors loss. In late-stage STGD1-like patient and blue light-illuminated Abca4-/- mice, lipofuscin and melanolipofuscin granules were found to contribute to NIR-AF, indicated by the colocalization of lipofuscin-AF and NIR-AF under the fluorescence microscope. In this mouse model, the correlation between in vivo and ex vivo assessments revealed histological characteristics of fundus AF abnormalities. The flecks which are hyper AF in both SW-AF and NIR-AF corresponded to the subretinal macrophages fully packed with pigment granules (lipofuscin, melanin, and melanolipofuscin). This mouse model, which has the phenotype of advanced STGD1, is important to understand the histopathology of Stargardt disease.
Collapse
Affiliation(s)
- Yuan Fang
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Alexander Tschulakow
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
- Preclinical Drug Assessment, STZ Ocutox, Hechingen, Germany
| | - Tatjana Taubitz
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Barbara Illing
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Antje Biesemeier
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
| | - Sylvie Julien-Schraermeyer
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
- Preclinical Drug Assessment, STZ Ocutox, Hechingen, Germany
| | - Roxana A Radu
- UCLA Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Zhichun Jiang
- UCLA Stein Eye Institute, Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Ulrich Schraermeyer
- Division of Experimental Vitreoretinal Surgery, Center for Ophthalmology, Institute of Ophthalmic Research, University of Tuebingen, Tuebingen, Germany
- Preclinical Drug Assessment, STZ Ocutox, Hechingen, Germany
| |
Collapse
|
22
|
Roy A, Pittman M, Saitta ET, Kaye TG, Xu X. Recent advances in amniote palaeocolour reconstruction and a framework for future research. Biol Rev Camb Philos Soc 2020; 95:22-50. [PMID: 31538399 PMCID: PMC7004074 DOI: 10.1111/brv.12552] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 01/24/2023]
Abstract
Preserved melanin pigments have been discovered in fossilised integumentary appendages of several amniote lineages (fishes, frogs, snakes, marine reptiles, non-avialan dinosaurs, birds, and mammals) excavated from lagerstätten across the globe. Melanisation is a leading factor in organic integument preservation in these fossils. Melanin in extant vertebrates is typically stored in rod- to sphere-shaped, lysosome-derived, membrane-bound vesicles called melanosomes. Black, dark brown, and grey colours are produced by eumelanin, and reddish-brown colours are produced by phaeomelanin. Specific morphotypes and nanostructural arrangements of melanosomes and their relation to the keratin matrix in integumentary appendages create the so-called 'structural colours'. Reconstruction of colour patterns in ancient animals has opened an exciting new avenue for studying their life, behaviour and ecology. Modern relationships between the shape, arrangement, and size of avian melanosomes, melanin chemistry, and feather colour have been applied to reconstruct the hues and colour patterns of isolated feathers and plumages of the dinosaurs Anchiornis, Sinosauropteryx, and Microraptor in seminal papers that initiated the field of palaeocolour reconstruction. Since then, further research has identified countershading camouflage patterns, and informed subsequent predictions on the ecology and behaviour of these extinct animals. However, palaeocolour reconstruction remains a nascent field, and current approaches have considerable potential for further refinement, standardisation, and expansion. This includes detailed study of non-melanic pigments that might be preserved in fossilised integuments. A common issue among existing palaeocolour studies is the lack of contextualisation of different lines of evidence and the wide variety of techniques currently employed. To that end, this review focused on fossil amniotes: (i) produces an overarching framework that appropriately reconstructs palaeocolour by accounting for the chemical signatures of various pigments, morphology and local arrangement of pigment-bearing vesicles, pigment concentration, macroscopic colour patterns, and taphonomy; (ii) provides background context for the evolution of colour-producing mechanisms; and (iii) encourages future efforts in palaeocolour reconstructions particularly of less-studied groups such as non-dinosaur archosaurs and non-archosaur amniotes.
Collapse
Affiliation(s)
- Arindam Roy
- Vertebrate Palaeontology Laboratory, Department of Earth SciencesThe University of Hong KongPokfulamHong Kong SARChina
| | - Michael Pittman
- Vertebrate Palaeontology Laboratory, Department of Earth SciencesThe University of Hong KongPokfulamHong Kong SARChina
| | - Evan T. Saitta
- Integrative Research Center, Section of Earth SciencesField Museum of Natural History1400 S. Lake Shore Drive, ChicagoIL60605U.S.A.
| | - Thomas G. Kaye
- Foundation for Scientific Advancement7023 Alhambra Drive, Sierra VistaAZ85650U.S.A.
| | - Xing Xu
- Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of Sciences142 Xizhimenwai Street.Beijing100044China
| |
Collapse
|
23
|
Abstract
Tyrosinase is a key enzyme involved in melanin synthesis. Therefore, various tyrosinase inhibitors have been screened by researchers in recent years. In the present study, we discovered a novel tyrosinase inhibitor, a peptide ECGYF (named EF-5), with free radical scavenging ability. The effect of tyrosinase inhibition by EF-5 was stronger than that of arbutin and glutathione, when analyzed both in vitro (IC50: 0.46 mM) and in vivo. The UV-Vis absorption and circular dichroism spectroscopies indicated that EF-5 interacted with tyrosinase in a different way as that of glutathione. The results of molecular docking showed that the binding between EF-5 and tyrosinase was determined majorly by hydrogen bonds and hydrophobic interactions. EF-5 had also retained its ability to scavenge both hydroxyl and superoxide radicals in vitro and was found to be nontoxic to cells, as revealed by the MTT assay. These features suggested that the EF-5 peptide may serve as a safe and effective alternative as a tyrosinase inhibitor.
Collapse
Affiliation(s)
- Zhiwei Shen
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai , China.,University of Chinese Academy of Sciences , Beijing , China
| | - Yujiao Wang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai , China.,University of Chinese Academy of Sciences , Beijing , China
| | - Zhen Guo
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai , China.,University of Chinese Academy of Sciences , Beijing , China
| | - Tingyuan Tan
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai , China.,University of Chinese Academy of Sciences , Beijing , China
| | - Yi Zhang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai , China.,Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences , Shanghai , China
| |
Collapse
|
24
|
Abstract
Melanins are a class of pigments that are ubiquitous throughout biology. They play incredibly diverse and important roles ranging from radiation protection to immune defense, camouflage, and virulence. Fungi have evolved to use melanin to be able to persist in the environment and within organisms. Fungal melanins are often located within the cell well and are able to neutralize reactive oxygen species and other radicals, defend against UV radiation, bind and sequester non-specific peptides and compounds, and produce a physical barrier that defends the cell. For this reason, melanized fungi are often well-suited to be human pathogens-melanin allows fungi to neutralize the microbicidal oxidative bursts of our innate immune system, bind and inactivate to antimicrobial peptides and enzymes, sequester antifungal pharmaceuticals, and create a shield to block immune recognition of the fungus. Due to the importance and pervasiveness of melanin in fungal virulence, mammalian immune systems have evolved antifungal strategies that involve directly detecting and binding to fungal melanins. Such strategies include the use of melanin-specific antibody responses and C-type lectins like the newly discovered melanin-specific MelLec receptor.
Collapse
|
25
|
Ushakova N, Dontsov A, Sakina N, Bastrakov A, Ostrovsky M. Antioxidative Properties of Melanins and Ommochromes from Black Soldier Fly Hermetia illucens. Biomolecules 2019; 9:E408. [PMID: 31450873 PMCID: PMC6770681 DOI: 10.3390/biom9090408] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/18/2019] [Accepted: 08/20/2019] [Indexed: 12/23/2022] Open
Abstract
A comparative study of melanin and ommochrome-containing samples, isolated from the black soldier fly (BSF) by enzymatic hydrolysis, alkaline and acid alcohol extraction or by acid hydrolysis, was carried out. Melanin was isolated both as a melanin-chitin complex and as a water-soluble melanin. Acid hydrolysis followed by delipidization yielded a more concentrated melanin sample, the electron spin resonance (ESR) signal of which was 2.6 × 1018 spin/g. The ommochromes were extracted from the BSF eyes with acid methanol. The antiradical activity of BSF melanins and ommochromes was determined by the method of quenching of luminol chemiluminescence. It has been shown that delipidization of water-soluble melanin increases its antioxidant properties. A comparison of the antioxidant activity of BSF melanins and ommochromes in relation to photoinduced lipid peroxidation was carried out. The ESR characteristics of native and oxidized melanins and ommochromes were studied. It is assumed that H. illucens adult flies can be a useful source of natural pigments with antioxidant properties.
Collapse
Affiliation(s)
- Nina Ushakova
- A.N. Severtsov Institute of Ecology and Evolution of Russian Academy of Sciences, 119071 Moscow, Russia.
| | - Alexander Dontsov
- N.M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia
| | - Natalia Sakina
- N.M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia
| | - Alexander Bastrakov
- A.N. Severtsov Institute of Ecology and Evolution of Russian Academy of Sciences, 119071 Moscow, Russia
| | - Mikhail Ostrovsky
- N.M. Emanuel Institute of Biochemical Physics of Russian Academy of Sciences, 119334 Moscow, Russia
| |
Collapse
|
26
|
Meleppat RK, Zhang P, Ju MJ, Manna SK, Jian Y, Pugh EN, Zawadzki RJ. Directional optical coherence tomography reveals melanin concentration-dependent scattering properties of retinal pigment epithelium. J Biomed Opt 2019; 24:1-10. [PMID: 31254332 PMCID: PMC6977406 DOI: 10.1117/1.jbo.24.6.066011] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/30/2019] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) is a powerful tool in ophthalmology that provides in vivo morphology of the retinal layers and their light scattering properties. The directional (angular) reflectivity of the retinal layers was investigated with focus on the scattering from retinal pigment epithelium (RPE). The directional scattering of the RPE was studied in three mice strains with three distinct melanin concentrations: albino (BALB/c), agouti (129S1/SvlmJ), and strongly pigmented (C57BL/6J). The backscattering signal strength was measured with a directional OCT system in which the pupil entry position of the narrow OCT beam can be varied across the dilated pupil of the eyes of the mice. The directional reflectivity of other retinal melanin-free layers, including the internal and external limiting membranes, and Bruch's membrane (albinos) were also measured and compared between the strains. The intensity of light backscattered from these layers was found highly sensitive to the angle of illumination, whereas the inner/outer segment (IS/OS) junctions showed a reduced sensitivity. The reflections from the RPE are largely insensitive in highly pigmented mice. The differences in directional scattering between strains shows that directionality decreases with an increase in melanin concentrations in RPE, suggesting increasing contribution of Mie scattering by melanosomes.
Collapse
Affiliation(s)
- Ratheesh K. Meleppat
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Pengfei Zhang
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Myeong Jin Ju
- Simon Fraser University, School of Engineering Science, Burnaby, British Columbia, Canada
| | - Suman K. Manna
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Yifan Jian
- Oregon Science and Health University, Casey Eye Institute, Portland, Oregon, United States
| | - Edward N. Pugh
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Robert J. Zawadzki
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
- University of California Davis, UC Davis Eye Center, Department of Ophthalmology and Vision Science, Sacramento, California, United States
- Address all correspondence to Robert J. Zawadzki, E-mail:
| |
Collapse
|
27
|
|
28
|
Chen L, Lee W, de Carvalho JRL, Chang S, Tsang SH, Allikmets R, Sparrow JR. Multi-platform imaging in ABCA4-Associated Disease. Sci Rep 2019; 9:6436. [PMID: 31015497 PMCID: PMC6478712 DOI: 10.1038/s41598-019-42772-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 04/01/2019] [Indexed: 12/24/2022] Open
Abstract
Fundus autofluorescence (FAF) imaging is crucial to the diagnosis and monitoring of recessive Stargardt disease (STGD1). In a retrospective cohort study of 34 patients, we compared FAF imaging platforms varying in field size (30° and 55°: blue/SW-AF and NIR-AF; 200°: ultrawide-field, UWF-AF), excitation wavelength (488 nm, blue/SW-AF; 532 nm, UWF-AF and 787 nm, NIR-AF) and image processing. Due to reduced absorption of 532 nm and 787 nm light by macular pigment, foveal sparing was more readily demonstrable by green/UWF-AF and NIR-AF imaging. Prominent in green/UWF-AF images is a central zone of relatively elevated AF that is continuous inferonasal with a demarcation line bordering lower AF nasally and higher AF temporally. This zone and border are more visible in STGD1 than in healthy eyes and more visible with green/UWF-AF. With the development of AF flecks, inferonasal retina is initially spared. Central atrophic areas were larger in NIR-AF images than in blue/SW-AF and green/UWF-AF images and the presence of a contiguous hyperAF ring varied with imaging modality. Flecks visible as hyperAF foci in blue/SW-AF images were also visible in green/UWF-AF but were often hypoAF in NIR-AF. Since disease in STGD1 often extends beyond the 30° and 55° fields, green/UWF-AF has advantages including for pediatric patients. The imaging platforms examined provided complementary information.
Collapse
Affiliation(s)
- Lijuan Chen
- Department of Ophthalmology, Columbia University, New York, New York, United States.,Department of Ophthalmology, People's hospital of Putuo District, Shanghai, China
| | - Winston Lee
- Department of Ophthalmology, Columbia University, New York, New York, United States
| | - Jose Ronaldo Lima de Carvalho
- Department of Ophthalmology, Columbia University, New York, New York, United States.,Departament of Ophthalmology, Empresa Brasileira de Servicos Hospitalares (EBSERH) - Hospital das Clinicas de Pernambuco (HCPE), Federal University of Pernambuco (UFPE), Recife, Brazil.,Department of Ophthalmology, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Stanley Chang
- Department of Ophthalmology, Columbia University, New York, New York, United States
| | - Stephen H Tsang
- Department of Ophthalmology, Columbia University, New York, New York, United States.,Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
| | - Rando Allikmets
- Department of Ophthalmology, Columbia University, New York, New York, United States.,Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University, New York, New York, United States. .,Department of Pathology and Cell Biology, Columbia University, New York, New York, United States.
| |
Collapse
|
29
|
Brunetti A, Arciuli M, Triggiani L, Sallustio F, Gallone A, Tommasi R. Do thermal treatments influence the ultrafast opto-thermal processes of eumelanin? Eur Biophys J 2019; 48:153-60. [DOI: 10.1007/s00249-018-1342-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/12/2018] [Accepted: 12/10/2018] [Indexed: 10/27/2022]
|
30
|
Abstract
The retinal pigment epithelium (RPE) is essential to the health of the retina and the proper functioning of the photoreceptors. The RPE is rich in melanosomes, which contain the pigment melanin. Changes in RPE pigmentation are seen with normal aging and in diseases such as albinism and age-related macular degeneration. However, most techniques used to this day to detect and quantify ocular melanin are performed ex vivo and are destructive to the tissue. There is a need for in vivo imaging of melanin both at the clinical and pre-clinical level to study how pigmentation changes can inform disease progression. In this manuscript, we review in vivo imaging techniques such as fundus photography, fundus reflectometry, near-infrared autofluorescence imaging, photoacoustic imaging, and functional optical coherence tomography that specifically detect melanin in the retina. These methods use different contrast mechanisms to detect melanin and provide images with different resolutions and field-of-views, making them complementary to each other.
Collapse
Affiliation(s)
- Maryse Lapierre-Landry
- 1Morgridge Institute for Research, Madison, WI USA.,2Department of Biomedical Engineering, Vanderbilt University, Nashville, TN USA.,6Department of Pediatrics, Case Western Reserve University, Cleveland, OH USA
| | - Joseph Carroll
- 3Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI USA.,4Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI USA
| | - Melissa C Skala
- 1Morgridge Institute for Research, Madison, WI USA.,5Department of Biomedical Engineering, University of Wisconsin Madison, Madison, WI USA
| |
Collapse
|
31
|
Srisuk P, Bishi DK, Berti FV, Silva CJR, Kwon IK, Correlo VM, Reis RL. Eumelanin Nanoparticle-Incorporated Polyvinyl Alcohol Nanofibrous Composite as an Electroconductive Scaffold for Skeletal Muscle Tissue Engineering. ACS Appl Bio Mater 2018; 1:1893-1905. [DOI: 10.1021/acsabm.8b00465] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Pathomthat Srisuk
- 3B’s Research Group, I3Bs, Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, Guimarães 4805-017, Portugal
- ICVS/3B’s, PT Government Associate Laboratory, Braga 4805-017, Portugal
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, 123 Mittraphab Highway, Mueang
District, Khon Kaen 40002, Thailand
| | - Dillip K. Bishi
- 3B’s Research Group, I3Bs, Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, Guimarães 4805-017, Portugal
- ICVS/3B’s, PT Government Associate Laboratory, Braga 4805-017, Portugal
| | - Fernanda V. Berti
- 3B’s Research Group, I3Bs, Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, Guimarães 4805-017, Portugal
- ICVS/3B’s, PT Government Associate Laboratory, Braga 4805-017, Portugal
- Department of Chemical and Food Engineering, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040, Brazil
| | - Carlos J. R. Silva
- Department/Center of Chemistry, Universidade do Minho, Braga 4710-057, Portugal
| | - Il Keun Kwon
- Department of Dental Materials, School of Dentistry, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02477, Republic of Korea
| | - Vitor M. Correlo
- 3B’s Research Group, I3Bs, Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, Guimarães 4805-017, Portugal
- ICVS/3B’s, PT Government Associate Laboratory, Braga 4805-017, Portugal
- The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, Avepark, Barco, Guimarães 4805-017, Portugal
| | - Rui L. Reis
- 3B’s Research Group, I3Bs, Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Avepark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, Barco, Guimarães 4805-017, Portugal
- ICVS/3B’s, PT Government Associate Laboratory, Braga 4805-017, Portugal
- Department of Dental Materials, School of Dentistry, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul 02477, Republic of Korea
- The Discoveries Centre for Regenerative and Precision Medicine, Headquarters at University of Minho, Avepark, Barco, Guimarães 4805-017, Portugal
| |
Collapse
|
32
|
Yacout SM, Elsawa SF, Gaillard ER. Calf melanin immunomodulates RPE cell attachment to extracellular matrix protein. Graefes Arch Clin Exp Ophthalmol 2018; 256:1883-1893. [PMID: 30066027 DOI: 10.1007/s00417-018-4083-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 07/23/2018] [Accepted: 07/26/2018] [Indexed: 10/28/2022] Open
Abstract
PURPOSE It is widely accepted that RPE melanin has a protective effect against oxidative damage in RPE cells. It is possible that an additional protective characteristic of melanin is the ability to modulate RPE cell immune response. In this study, in vitro modeling was used to probe the relationship between RPE pigmentation and immune response by monitoring IL-6 expression and secretion in calf melanin pigmented ARPE-19 cells seeded onto glycated extracellular matrix as a stressor. METHODS ARPE-19 cells were left unpigmented or were pigmented with either calf melanin or latex beads, and were then seeded onto RPE-derived extracellular matrix (ECM) or tissue culture-treated plates (no ECM). ECMs were modified by glycation. IL-6 expression was measured using qPCR and IL-6 secretion was determined using an ELISA, both at 30 min and 24 h after seeding. MTT assay was used to quantify cell attachment to glycated matrices 30 min after seeding. In unpigmented ARPE-19 cells, rate of cell attachment to substrate was monitored for 60 min after seeding using a hemacytometer to count unattached cells. Additionally, cell viability was evaluated using the Neutral Red assay 24 h after seeding. RESULTS A significant increase in IL-6 expression was observed in calf melanin pigmented cells versus latex bead and unpigmented controls (p < 0.0001) 30 min after seeding onto ECM. Twenty-four hours after seeding, a significant decrease in IL-6 expression was observed in calf melanin pigmented cells (p < 0.0001) versus controls, implicating down-regulation of the cytokine. Additionally, calf melanin pigmented cell populations showed significant increase in attachment compared to unpigmented controls on either no ECM or unmodified ECM. CONCLUSIONS Pigmentation of RPE cells with calf melanin resulted in significant changes in IL-6 expression regardless of ECM modification, in vitro. These findings suggest that melanin in the RPE may participate in immune response modulation in the retina with particular regard to cell attachment to protein substrates. The results of this study further implicate the role of chemical changes to melanin in regulating inflammation in retinal disease.
Collapse
Affiliation(s)
- Sally M Yacout
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA
| | - Sherine F Elsawa
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, 60115, USA
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, 03824, USA
| | - Elizabeth R Gaillard
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, 60115, USA.
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL, 60115, USA.
| |
Collapse
|
33
|
Yacout SM, McIlwain KL, Mirza SP, Gaillard ER. Characterization of Retinal Pigment Epithelial Melanin and Degraded Synthetic Melanin Using Mass Spectrometry and In Vitro Biochemical Diagnostics. Photochem Photobiol 2018; 95:183-191. [PMID: 29752877 DOI: 10.1111/php.12934] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/24/2018] [Indexed: 12/14/2022]
Abstract
With increasing age, there is an observable loss of melanin in retinal pigment epithelial (RPE) cells. It is possible that degradation of the pigment contributes to the pathogenesis of retinal disease, as the cellular antioxidant material is depleted. Functionally, intact melanin maintains protective qualities, while oxidative degradation of melanin promotes reactive oxygen species (ROS) generation and formation of metabolic byproducts, such as melanolipofuscin. Understanding the structural and functional changes to RPE melanin with increasing age may contribute to a better understanding of disease progression and risk factors for conditions such as age-related macular degeneration (AMD). In this study, human donor RPE melanin is characterized using MALDI mass spectrometry to follow melanin degradation trends. In vitro models using ARPE-19 cells are used to assess photo-reactivity in repigmented cells. Significant protection against intracellular ROS produced by blue light is observed in calf melanin-pigmented cells versus unpigmented and black latex bead controls (P < 0.0001). UV-B exposure to aged human melanin-pigmented cells results in a significant increase in nitric oxide production versus control cells (P < 0.001). Peroxide-treated synthetic melanin is characterized to elucidate degradation products that may contribute to RPE cell damage.
Collapse
Affiliation(s)
- Sally M Yacout
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL
| | - Kelsey L McIlwain
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL
| | - Shama P Mirza
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI
| | - Elizabeth R Gaillard
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL.,Department of Biological Sciences, Northern Illinois University, DeKalb, IL
| |
Collapse
|
34
|
Adetunji SA, Krecek RC, O'Dell N, Prozesky L, Steyl J, Arenas-Gamboa AM. MELANOMA IN GOLDEN AND KING WILDEBEESTS ( CONNOCHAETES TAURINUS). J Zoo Wildl Med 2018; 49:134-42. [PMID: 29517449 DOI: 10.1638/2017-0059R1.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Pigmentation of the skin is a crucial component in the pathogenesis of melanocytic neoplasms and other skin-related tumors, as melanin is known to function in both the absorbance of ultraviolet radiation and as an antioxidant. Very limited information exists regarding the incidence and metastatic potential of neoplastic conditions of the skin in game animals, especially wildebeests, relative to domestic animals. Four cases of cutaneous melanoma in color-variant golden and king wildebeests ( Connochaetes taurinus) (from 2014 to 2015) in South Africa were investigated. Melanoma in these captive animals was characterized using histopathology, transmission electron microscopy, and an immunohistochemistry panel, which consisted of monoclonal antibodies against three melanocytic markers: Melan A, PNL2, and S100. Overall, 2/4 cases (50%) of the melanocytic neoplasms stained strongly positive for all the melanocytic markers, while 4/4 cases (100%) stained positively for at least one of the markers. Cutaneous melanocytic neoplasia has not been reported in wildebeests; the current study suggests that selection of wildebeests for coat color potentially predisposes to this condition.
Collapse
|
35
|
Dontsov AE, Sakina NL, Ostrovsky MA. Loss of melanin by eye retinal pigment epithelium cells is associated with its oxidative destruction in melanolipofuscin granules. Biochemistry Moscow 2017; 82:916-924. [DOI: 10.1134/s0006297917080065] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
36
|
Juuti-Uusitalo K, Koskela A, Kivinen N, Viiri J, Hyttinen JMT, Reinisalo M, Koistinen A, Uusitalo H, Sinha D, Skottman H, Kaarniranta K. Autophagy Regulates Proteasome Inhibitor-Induced Pigmentation in Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells. Int J Mol Sci 2017; 18:E1089. [PMID: 28534814 DOI: 10.3390/ijms18051089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 05/11/2017] [Accepted: 05/12/2017] [Indexed: 02/06/2023] Open
Abstract
The impairment of autophagic and proteasomal cleansing together with changes in pigmentation has been documented in retinal pigment epithelial (RPE) cell degeneration. However, the function and co-operation of these mechanisms in melanosome-containing RPE cells is still unclear. We show that inhibition of proteasomal degradation with MG-132 or autophagy with bafilomycin A1 increased the accumulation of premelanosomes and autophagic structures in human embryonic stem cell (hESC)-derived RPE cells. Consequently, upregulation of the autophagy marker p62 (also known as sequestosome-1, SQSTM1) was confirmed in Western blot and perinuclear staining. Interestingly, cells treated with the adenosine monophosphatedependent protein kinase activator, AICAR (5-Aminoimidazole-4-carboxamide ribonucleotide), decreased the proteasome inhibitor-induced accumulation of premelanosomes, increased the amount of autophagosomes and eradicated the protein expression of p62 and LC3 (microtubule-associated protein 1A/1B-light chain 3). These results revealed that autophagic machinery is functional in hESC-RPE cells and may regulate cellular pigmentation with proteasomes.
Collapse
|
37
|
Affiliation(s)
- Anna Polosa
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Hyba Bessaklia
- Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada
| | - Pierre Lachapelle
- Department of Ophthalmology, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| |
Collapse
|
38
|
Cao J, Tyburczy ME, Moss J, Darling TN, Widlund HR, Kwiatkowski DJ. Tuberous sclerosis complex inactivation disrupts melanogenesis via mTORC1 activation. J Clin Invest 2016; 127:349-364. [PMID: 27918305 DOI: 10.1172/jci84262] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/20/2016] [Indexed: 12/20/2022] Open
Abstract
Tuberous sclerosis complex (TSC) is an autosomal dominant tumor-suppressor gene syndrome caused by inactivating mutations in either TSC1 or TSC2, and the TSC protein complex is an essential regulator of mTOR complex 1 (mTORC1). Patients with TSC develop hypomelanotic macules (white spots), but the molecular mechanisms underlying their formation are not fully characterized. Using human primary melanocytes and a highly pigmented melanoma cell line, we demonstrate that reduced expression of either TSC1 or TSC2 causes reduced pigmentation through mTORC1 activation, which results in hyperactivation of glycogen synthase kinase 3β (GSK3β), followed by phosphorylation of and loss of β-catenin from the nucleus, thereby reducing expression of microphthalmia-associated transcription factor (MITF), and subsequent reductions in tyrosinase and other genes required for melanogenesis. Genetic suppression or pharmacological inhibition of this signaling cascade at multiple levels restored pigmentation. Importantly, primary melanocytes isolated from hypomelanotic macules from 6 patients with TSC all exhibited reduced TSC2 protein expression, and 1 culture showed biallelic mutation in TSC2, one of which was germline and the second acquired in the melanocytes of the hypomelanotic macule. These findings indicate that the TSC/mTORC1/AKT/GSK3β/β-catenin/MITF axis plays a central role in regulating melanogenesis. Interventions that enhance or diminish mTORC1 activity or other nodes in this pathway in melanocytes could potentially modulate pigment production.
Collapse
|
39
|
Calvo-Maroto AM, Esteve-Taboada JJ, Domínguez-Vicent A, Pérez-Cambrodí RJ, Cerviño A. Confocal scanning laser ophthalmoscopy versus modified conventional fundus camera for fundus autofluorescence. Expert Rev Med Devices 2016; 13:965-978. [PMID: 27634136 DOI: 10.1080/17434440.2016.1236678] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Fundus autofluorescence (FAF) is a noninvasive imaging method to detect fundus endogenous fluorophores, mainly lipofuscin located in the retinal pigment epithelium (RPE). The FAF provides information about lipofuscin distribution and RPE health, and consequently an increased accumulation of lipofuscin has been correlated with ageing and development of certain retinal conditions. Areas covered: An exhaustive literature search in MEDLINE (via OVID) and PUBMED for articles related to ocular FAF in retinal diseases and different devices used for acquiring FAF imaging was conducted. Expert commentary: This review aims to show an overview about autofluorescence in the RPE and the main devices used for acquiring these FAF images. The knowledge of differences in the optical principles, acquisition images and the image post-processing between confocal scanning laser ophthalmoscopy and modified conventional fundus camera will improve the FAF images interpretation when are used as a complementary diagnosis and monitoring tool of retinal diseases.
Collapse
Affiliation(s)
- Ana M Calvo-Maroto
- a Optometry Research Group, Department of Optics & Optometry & Vision Sciences , University of Valencia , Valencia , Spain
| | - Jose J Esteve-Taboada
- a Optometry Research Group, Department of Optics & Optometry & Vision Sciences , University of Valencia , Valencia , Spain
| | - Alberto Domínguez-Vicent
- a Optometry Research Group, Department of Optics & Optometry & Vision Sciences , University of Valencia , Valencia , Spain
| | | | - Alejandro Cerviño
- a Optometry Research Group, Department of Optics & Optometry & Vision Sciences , University of Valencia , Valencia , Spain
| |
Collapse
|
40
|
Ju KY, Kang J, Chang JH, Lee JK. Clue to Understanding the Janus Behavior of Eumelanin: Investigating the Relationship between Hierarchical Assembly Structure of Eumelanin and Its Photophysical Properties. Biomacromolecules 2016; 17:2860-72. [DOI: 10.1021/acs.biomac.6b00686] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kuk-Youn Ju
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Jeeun Kang
- Department
of Electronics Engineering and Sogang Institute of Advanced Technology, Sogang University, Seoul, 121-742, Korea
| | - Jin Ho Chang
- Department
of Electronics Engineering and Sogang Institute of Advanced Technology, Sogang University, Seoul, 121-742, Korea
| | - Jin-Kyu Lee
- Department
of Chemistry, Seoul National University, Seoul 151-747, Korea
| |
Collapse
|
41
|
Dontsov AE, Sakina NL, Koromyslova AD, Ostrovsky MA. Effect of UV radiation and hydrogen peroxide on the antiradical and antioxidant activities of DOPA-melanin and melanosomes from retinal pigment epithelial cells. Russ Chem Bull 2015; 64:1623-8. [DOI: 10.1007/s11172-015-1051-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
42
|
Abstract
Fundus autofluorescence (FAF) is a non-invasive retinal imaging modality used in clinical practice to provide a density map of lipofuscin, the predominant ocular fluorophore, in the retinal pigment epithelium. Multiple commercially available imaging systems, including the fundus camera, the confocal scanning laser ophthalmoscope, and the ultra-widefield imaging device, are available to the clinician. Each offers unique advantages for evaluating various retinal diseases. The clinical applications of FAF continue to expand. It is now an essential tool for evaluating age related macular degeneration, macular dystrophies, retinitis pigmentosa, white dot syndromes, retinal drug toxicities, and various other retinal disorders. FAF may detect abnormalities beyond those detected on funduscopic exam, fluorescein angiography, or optical coherence tomography, and can be used to elucidate disease pathogenesis, form genotype-phenotype correlations, diagnose and monitor disease, and evaluate novel therapies. Given its ease of use, non-invasive nature, and value in characterizing retinal disease, FAF enjoys increasing clinical relevance. This review summarizes common ocular fluorophores, imaging modalities, and FAF findings for a wide spectrum of retinal disorders.
Collapse
Affiliation(s)
- Madeline Yung
- Stein Eye Institute, David Geffen School of Medicine at University of California, Los Angeles, CA 90095 USA
| | - Michael A. Klufas
- Stein Eye Institute, David Geffen School of Medicine at University of California, Los Angeles, CA 90095 USA
| | - David Sarraf
- Stein Eye Institute, David Geffen School of Medicine at University of California, Los Angeles, CA 90095 USA
- Greater Los Angeles VA Healthcare Center, Los Angeles, CA 90024 USA
| |
Collapse
|
43
|
Parodi MB, Iacono P, Del Turco C, Triolo G, Bandello F. Functional assessment of the fundus autofluorescence pattern in Best vitelliform macular dystrophy. Graefes Arch Clin Exp Ophthalmol 2016; 254:1297-302. [DOI: 10.1007/s00417-015-3194-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/21/2015] [Accepted: 10/05/2015] [Indexed: 11/26/2022] Open
|
44
|
Pasovic L, Eidet JR, Brusletto BS, Lyberg T, Utheim TP. Effect of Storage Temperature on Key Functions of Cultured Retinal Pigment Epithelial Cells. J Ophthalmol 2015; 2015:263756. [PMID: 26448872 DOI: 10.1155/2015/263756] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/30/2015] [Accepted: 08/31/2015] [Indexed: 11/18/2022] Open
Abstract
Purpose. Replacement of the diseased retinal pigment epithelium (RPE) with cells capable of performing the specialized functions of the RPE is the aim of cell replacement therapy for treatment of macular degenerative diseases. A storage method for RPE is likely to become a prerequisite for the establishment of such treatment. Herein, we analyze the effect of storage temperature on key functions of cultured RPE cells. Methods. Cultured ARPE-19 cells were stored in Minimum Essential Medium at 4°C, 16°C, and 37°C for seven days. Total RNA was isolated and the gene expression profile was determined using DNA microarrays. Comparison of the microarray expression values with qRT-PCR analysis of selected genes validated the results. Results. Expression levels of several key genes involved in phagocytosis, pigment synthesis, the visual cycle, adherens, and tight junctions, and glucose and ion transport were maintained close to control levels in cultures stored at 4°C and 16°C. Cultures stored at 37°C displayed regulational changes in a larger subset of genes related to phagocytosis, adherens, and tight junctions. Conclusion. RPE cultures stored at 4°C and 16°C for one week are capable of maintaining the expression levels of genes important for key RPE functions close to control levels.
Collapse
|
45
|
Abstract
Diabetic retinopathy (DR) is one of today's main causes of blindness in numerous developed countries worldwide. The underlying pathogenesis of DR is complex and not well understood, thus impeding development of specific, effective treatment modalities. Consequently, the use of animal models of DR is of critical importance for investigating the pathogenesis of and treatment for DR. While rats and mice are the most commonly used animal models of DR, the zebrafish now appears to be a promising model. Nonhuman primates and humans have similar eye structures, and both can develop spontaneous diabetes mellitus (DM). Although various traditionally used animal models of DR undergo a number of pathological changes similar to those of human DR, several human variations, e.g. retinal neovascularization, cannot yet be fully mimicked in any existing animal model of DM. Since both the animal models and the methods chosen for inducing DR have great influence on experimental results, a clear understanding of available animal models is vital for planning an experimental design. In this review, we summarize the mechanisms, methodologies and pros and cons of the most commonly used animal models of DR.
Collapse
Affiliation(s)
- Xiaoyan Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University , Guangzhou , P.R. China
| | | | | |
Collapse
|
46
|
Gonzalez-Fernandez F, Betts-Obregon B, Yust B, Mimun J, Sung D, Sardar D, Tsin AT. Interphotoreceptor retinoid-binding protein protects retinoids from photodegradation. Photochem Photobiol 2015; 91:371-8. [PMID: 25565073 DOI: 10.1111/php.12416] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/16/2014] [Indexed: 12/20/2022]
Abstract
Retinol degrades rapidly in light into a variety of photoproducts. It is remarkable that visual cycle retinoids can evade photodegradation as they are exchanged between the photoreceptors, retinal pigment epithelium and Müller glia. Within the interphotoreceptor matrix, all-trans retinol, 11-cis retinol and retinal are bound by interphotoreceptor retinoid-binding protein (IRBP). Apart from its role in retinoid trafficking and targeting, could IRBP have a photoprotective function? HPLC was used to evaluate the ability of IRBP to protect all-trans and 11-cis retinols from photodegradation when exposed to incandescent light (0 to 8842 μW cm(-2)); time periods of 0-60 min, and bIRBP: retinol molar ratios of 1:1 to 1:5. bIRBP afforded a significant prevention of both all-trans and 11-cis retinol to rapid photodegradation. The effect was significant over the entire light intensity range tested, and extended to the bIRBP: retinol ratio 1:5. In view of the continual exposure of the retina to light, and the high oxidative stress in the outer retina, our results suggest IRBP may have an important protective role in the visual cycle by reducing photodegradation of all-trans and 11-cis retinols. This role of IRBP is particularly relevant in the high flux conditions of the cone visual cycle.
Collapse
Affiliation(s)
- Federico Gonzalez-Fernandez
- Medical Research Service, G.V. (Sonny) Montgomery Veterans Affairs Medical Center, Jackson, MS; Departments of Ophthalmology & Pathology, University of Mississippi School of Medicine, Jackson, MS; SUNY Eye Institute, State University of New York, Buffalo, NY
| | | | | | | | | | | | | |
Collapse
|
47
|
Iacono P, Battaglia PM, Papayannis A, La Spina C, Varano M, Bandello F. Acute central serous chorioretinopathy: a correlation study between fundus autofluorescence and spectral-domain OCT. Graefes Arch Clin Exp Ophthalmol 2015; 253:1889-97. [PMID: 25563727 DOI: 10.1007/s00417-014-2899-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the correlation between fundus autofluorescence (FAF) and spectral-domain OCT (SD-OCT) morphological analysis in eyes with acute central serous chorioretinopathy (CSCR). METHODS Thirty-one patients with a first episode of CSCR and symptom duration of less than 6 weeks were prospectively enrolled. FAF and SD-OCT examination were performed at baseline and at 2-month intervals. Main outcome measure was the correlation between FAF and SD-OCT retinal morphology. RESULTS At baseline, 30/31 and 29/31 eyes showed a macular hypo-AF, corresponding to the neurosensory retinal detachment (SRD), on shortwave-FAF (SW-FAF) and near-infrared-FAF (NIR-FAF), respectively. While the SRD resolved, both FAF techniques showed a granular hyper-AF in 31 eyes. At first examination, SD-OCT confirmed the SRD with a photoreceptor outer-segment (OS) elongation in all cases. During SRD resolution, the photoreceptor layer appeared thicker and fragmented. Multiple hyper-reflective precipitates were detected in the outer plexiform and nuclear layer and between the photoreceptors and appeared colocalized with the hyper-AF dots composing the granular hyper-AF. After SRD resolution, the hypo-AF area reverted to a normal pattern on SW-FAF in all eyes and in 25/31 on NIR-FAF. Examination at 12 months showed that the granular hyper-AF was still detectable in 54 % eyes, whereas 6/31 eyes showed hypo-AF dots on NIR-FAF. On SD-OCT, the junction IS/OS was identifiable in 11/31 eyes soon after the SRD resolution and appeared completely restored in all patients at the final visit. CONCLUSION The simultaneous acquisition of FAF and SD-OCT provides detailed findings of retinal abnormalities of CSCR and may help to understand the evolving process linked to CSCR.
Collapse
|
48
|
Iacono P, Battaglia PM, Papayannis A, La Spina C, Varano M, Bandello F. Acute central serous chorioretinopathy: a correlation study between fundus autofluorescence and spectral-domain OCT. Graefes Arch Clin Exp Ophthalmol 2015; 253:1889-97. [PMID: 25563727 DOI: 10.1007/s00417-014-2899-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 11/24/2014] [Accepted: 12/15/2014] [Indexed: 10/24/2022] Open
Affiliation(s)
- Pierluigi Iacono
- Fondazione G. B. Bietti per l'Oftalmologia, IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Via Livenza 3, Rome, Italy.
| | - Parodi Maurizio Battaglia
- Department of Ophthalmology, University Vita-Salute, Scientific Institute San Raffaele, Milan, Italy
| | | | - Carlo La Spina
- Department of Ophthalmology, University Vita-Salute, Scientific Institute San Raffaele, Milan, Italy
| | - Monica Varano
- Fondazione G. B. Bietti per l'Oftalmologia, IRCCS (Istituto di Ricovero e Cura a Carattere Scientifico), Via Livenza 3, Rome, Italy
| | - Francesco Bandello
- Department of Ophthalmology, University Vita-Salute, Scientific Institute San Raffaele, Milan, Italy
| |
Collapse
|
49
|
Abstract
The course of Age-related Macular Degeneration (AMD) is described as the effect of light (400–580 nm) on various molecular targets in photoreceptors and the retinal pigment epithelium (RPE). Photo-damage is followed by inflammation, increasing oxidative stress and, probably, unveiling new photosensitive molecules.
Collapse
Affiliation(s)
| | - Angela M. Suburo
- Medicina Celular y Molecular
- Facultad de Ciencias Biomédicas
- Universidad Austral
- Pilar B1629AHJ
- Argentina
| |
Collapse
|
50
|
Das P, Yuran S, Yan J, Lee PS, Reches M. Sticky tubes and magnetic hydrogels co-assembled by a short peptide and melanin-like nanoparticles. Chem Commun (Camb) 2015; 51:5432-5. [DOI: 10.1039/c4cc07671k] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The co-assembly of peptide monomers and polydopamine-based nanoparticles leads to the formation of either tubular structures decorated with adhesive particles or magnetic hydrogel.
Collapse
Affiliation(s)
- Priyadip Das
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Jerusalem 91904
- Israel
- The Center for Nanoscience and Nanotechnology
| | - Sivan Yuran
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Jerusalem 91904
- Israel
- The Center for Nanoscience and Nanotechnology
| | - Jian Yan
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore 639798
| | - Pooi See Lee
- School of Materials Science and Engineering
- Nanyang Technological University
- Singapore 639798
| | - Meital Reches
- Institute of Chemistry
- The Hebrew University of Jerusalem
- Jerusalem 91904
- Israel
- The Center for Nanoscience and Nanotechnology
| |
Collapse
|