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Fanelli G, Romano M, Lombardi G, Sacks SH. Soluble Collectin 11 (CL-11) Acts as an Immunosuppressive Molecule Potentially Used by Stem Cell-Derived Retinal Epithelial Cells to Modulate T Cell Response. Cells 2023; 12:1805. [PMID: 37443840 PMCID: PMC10341155 DOI: 10.3390/cells12131805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023] Open
Abstract
Retinal pigment epithelium (RPE) cell allotransplantation is seen as a possible solution to retinal diseases. However, the RPE-complement system triggered by the binding of collectin-11 (CL-11) is a potential barrier for RPE transplantation as the complement-mediated inflammatory response may promote T cell recognition. To address this, we investigated the role of CL-11 on T cell immuno-response. We confirmed that RPE cells up-regulated MHC class I and expressed MHC class II molecules in an inflammatory setting. Co-cultures of RPE cells with T cells led to the inhibition of T cell proliferation. We found that CL-11 was partially responsible for this effect as T cell binding of CL-11 inhibited T cell proliferation in association with the downregulation of CD28. We also found that the suppressive action of CL-11 was abrogated in the presence of the RGD peptide given to block the T cell binding of CL-11 by its collagen-like domain. Because RPE cells can bind and secrete CL-11 under stress conditions, we postulate that soluble CL-11 contributes to the immunosuppressive properties of RPE cells. The investigation of this dual biological activity of CL-11, namely as a trigger of the complement cascade and a modulator of T cell responses, may provide additional clues about the mechanisms that orchestrate the immunogenic properties of RPE cells.
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Affiliation(s)
- Giorgia Fanelli
- Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, King’s College, London SE1 9RT, UK; (M.R.); (G.L.); (S.H.S.)
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152
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Yang X, Chung JY, Rai U, Esumi N. SIRT6 overexpression in the nucleus protects mouse retinal pigment epithelium from oxidative stress. Life Sci Alliance 2023; 6:e202201448. [PMID: 37185874 PMCID: PMC10130745 DOI: 10.26508/lsa.202201448] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 05/17/2023] Open
Abstract
Retinal pigment epithelium (RPE) is essential for the survival of retinal photoreceptors. To study retinal degeneration, sodium iodate (NaIO3) has been used to cause oxidative stress-induced RPE death followed by photoreceptor degeneration. However, analyses of RPE damage itself are still limited. Here, we characterized NaIO3-induced RPE damage, which was divided into three regions: periphery with normal-shaped RPE, transitional zone with elongated cells, and center with severely damaged or lost RPE. Elongated cells in the transitional zone exhibited molecular characteristics of epithelial-mesenchymal transition. Central RPE was more susceptible to stresses than peripheral RPE. Under stresses, SIRT6, an NAD+-dependent protein deacylase, rapidly translocated from the nucleus to the cytoplasm and colocalized with stress granule factor G3BP1, leading to nuclear SIRT6 depletion. To overcome this SIRT6 depletion, SIRT6 overexpression was induced in the nucleus in transgenic mice, which protected RPE from NaIO3 and partially preserved catalase expression. These results demonstrate topological differences of mouse RPE and warrant further exploring SIRT6 as a potential target for protecting RPE from oxidative stress-induced damage.
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Affiliation(s)
- Xue Yang
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jin-Yong Chung
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Usha Rai
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Noriko Esumi
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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153
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Yang J, Hua Z, Zheng Z, Ma X, Zhu L, Li Y. Acteoside inhibits high glucose-induced oxidative stress injury in RPE cells and the outer retina through the Keap1/Nrf2/ARE pathway. Exp Eye Res 2023; 232:109496. [PMID: 37268044 DOI: 10.1016/j.exer.2023.109496] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 04/20/2023] [Accepted: 05/03/2023] [Indexed: 06/04/2023]
Abstract
Diabetes retinopathy (DR) is one of the most common microvascular complications of diabetes. Retinal pigment epithelial (RPE) cells exposed to a high glucose environment experience a series of functional damages, which is an important factor in promoting the progression of DR. Acteoside (ACT) has strong antioxidant and anti-apoptotic properties, but the mechanism of ACT in DR is not completely clear. Therefore, the purpose of the present study was to explore whether ACT inhibits the damage to RPE cells in a high glucose environment through antioxidative effects to alleviate the DR process. The DR in vitro cell model was constructed by treating RPE cells with high glucose, and the DR in vivo animal model was constructed by injecting streptozotocin (STZ) into the peritoneal cavity of mice to induce diabetes. The proliferation and apoptosis of RPE cells were detected by CCK-8 and flow cytometry assays, respectively. The expression changes in Nrf2, Keap1, NQO1 and HO-1 were evaluated by qRT‒PCR, Western blot and immunohistochemistry analyses. The MDA, SOD, GSH-Px and T-AOC contents were detected by kits. The changes in ROS and nuclear translocation of Nrf2 were observed by immunofluorescence assays. HE staining was used to measure the thickness of the outer nuclear layer (ONL) of the retina, and TUNEL staining was used to detect the number of apoptotic cells in the retinas of mice. In the present study, ACT effectively ameliorated outer retina damage in diabetic mice. In high glucose (HG)-induced RPE cells, ACT treatment had the following effects: improved proliferation, decreased apoptosis, inhibited Keap1 expression, promoted the nuclear translocation and expression of Nrf2, upregulated NQO1 and HO-1 (the target genes of Nrf2) expression, decreased ROS concentration, and increased the levels of the SOD, GSH-Px and T-AOC antioxidant indicators. However, knockdown of Nrf2 reversed the above phenomena, which indicated that the protective function of ACT in HG-induced RPE cells are closely related to Nrf2. In summary, the present study demonstrated that HG-induced oxidative stress injury is inhibited by ACT in RPE cells and the outer retina through the Keap1/Nrf2/ARE pathway.
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Affiliation(s)
- Jingfei Yang
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, 650032, China; Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, 650021, China
| | - Zhijuan Hua
- Department of Pediatric Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, 650021, China
| | - Zhikun Zheng
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, 650021, China
| | - Xuan Ma
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, 650021, China
| | - Liang Zhu
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, 650032, China
| | - Yan Li
- Department of Ophthalmology, The First Affiliated Hospital of Kunming Medical University, Kunming, 650032, China.
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154
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Markitantova Y, Simirskii V. Endogenous and Exogenous Regulation of Redox Homeostasis in Retinal Pigment Epithelium Cells: An Updated Antioxidant Perspective. Int J Mol Sci 2023; 24:10776. [PMID: 37445953 DOI: 10.3390/ijms241310776] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
The retinal pigment epithelium (RPE) performs a range of necessary functions within the neural layers of the retina and helps ensure vision. The regulation of pro-oxidative and antioxidant processes is the basis for maintaining RPE homeostasis and preventing retinal degenerative processes. Long-term stable changes in the redox balance under the influence of endogenous or exogenous factors can lead to oxidative stress (OS) and the development of a number of retinal pathologies associated with RPE dysfunction, and can eventually lead to vision loss. Reparative autophagy, ubiquitin-proteasome utilization, the repair of damaged proteins, and the maintenance of their conformational structure are important interrelated mechanisms of the endogenous defense system that protects against oxidative damage. Antioxidant protection of RPE cells is realized as a result of the activity of specific transcription factors, a large group of enzymes, chaperone proteins, etc., which form many signaling pathways in the RPE and the retina. Here, we discuss the role of the key components of the antioxidant defense system (ADS) in the cellular response of the RPE against OS. Understanding the role and interactions of OS mediators and the components of the ADS contributes to the formation of ideas about the subtle mechanisms in the regulation of RPE cellular functions and prospects for experimental approaches to restore RPE functions.
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Affiliation(s)
- Yuliya Markitantova
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
| | - Vladimir Simirskii
- Koltsov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
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155
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Zhang C, Xiao J, Fa L, Jiang F, Jiang H, Zhou L, Xu Z. Advances in the applications of mesenchymal stem cell-conditioned medium in ocular diseases. Exp Eye Res 2023:109560. [PMID: 37385531 DOI: 10.1016/j.exer.2023.109560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/06/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023]
Abstract
Mesenchymal stem cell-conditioned medium (MSC-CM), also known as secretome, is secreted by MSC and contains a variety of bioactive factors with anti-inflammatory, anti-apoptotic, neuroprotection, and proliferation effects. Increasing evidence proved that MSC-CM plays an important role in various diseases, including skin, bone, muscle, and dental diseases. However, the role of MSC-CM in ocular diseases is not quite clear, Therefore, this article reviewed the composition, biological functions, preparation, and characterization of MSC-CM and summarized current research advances in different sources of MSC-CM in corneal and retinal diseases, including dry eye, corneal epithelial damage, chemical corneal injury, retinitis pigmentosa (RP), anterior ischemic optic neuropathy (AION), diabetic retinopathy (DR), and other retinal degenerative changes. For these diseases, MSC-CM can promote cell proliferation, reduce inflammation and vascular leakage, inhibit retinal cell degeneration and apoptosis, protect corneal and retinal structures, and further improves visual function. Hence, we summarize the production, composition and biological functions of MSC-CM and focus on describing its mechanisms in the treatment of ocular diseases. Furthermore, we look at the unexplored mechanisms and further research directions for MSC-CM based therapy in ocular diseases.
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Affiliation(s)
- Chun Zhang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jing Xiao
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Luzhong Fa
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Fanwen Jiang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Hui Jiang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Lin Zhou
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Zhuping Xu
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
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156
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Zufiaurre-Seijo M, García-Arumí J, Duarri A. Clinical and Molecular Aspects of C2orf71/PCARE in Retinal Diseases. Int J Mol Sci 2023; 24:10670. [PMID: 37445847 DOI: 10.3390/ijms241310670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Mutations in the photoreceptor-specific C2orf71 gene (also known as photoreceptor cilium actin regulator protein PCARE) cause autosomal recessive retinitis pigmentosa type 54 and cone-rod dystrophy. No treatments are available for patients with C2orf71 retinal ciliopathies exhibiting a severe clinical phenotype. Our understanding of the disease process and the role of PCARE in the healthy retina significantly limits our capacity to transfer recent technical developments into viable therapy choices. This study summarizes the current understanding of C2orf71-related retinal diseases, including their clinical manifestations and an unclear genotype-phenotype correlation. It discusses molecular and functional studies on the photoreceptor-specific ciliary PCARE, focusing on the photoreceptor cell and its ciliary axoneme. It is proposed that PCARE is an actin-associated protein that interacts with WASF3 to regulate the actin-driven expansion of the ciliary membrane during the development of a new outer segment disk in photoreceptor cells. This review also introduces various cellular and animal models used to model these diseases and provides an overview of potential treatments.
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Affiliation(s)
- Maddalen Zufiaurre-Seijo
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
| | - José García-Arumí
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
| | - Anna Duarri
- Ophthalmology Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, 08035 Barcelona, Spain
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157
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Busch C, Rau S, Sekulic A, Perie L, Huber C, Gehrke M, Joussen AM, Zipfel PF, Wildner G, Skerka C, Strauß O. Increased plasma level of terminal complement complex in AMD patients: potential functional consequences for RPE cells. Front Immunol 2023; 14:1200725. [PMID: 37359546 PMCID: PMC10287163 DOI: 10.3389/fimmu.2023.1200725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/23/2023] [Indexed: 06/28/2023] Open
Abstract
Purpose Polymorphisms in complement genes are risk-associated for age-related macular degeneration (AMD). Functional analysis revealed a common deficiency to control the alternative complement pathway by risk-associated gene polymorphisms. Thus, we investigated the levels of terminal complement complex (TCC) in the plasma of wet AMD patients with defined genotypes and the impact of the complement activation of their plasma on second-messenger signaling, gene expression, and cytokine/chemokine secretion in retinal pigment epithelium (RPE) cells. Design Collection of plasma from patients with wet AMD (n = 87: 62% female and 38% male; median age 77 years) and controls (n = 86: 39% female and 61% male; median age 58 years), grouped for risk factor smoking and genetic risk alleles CFH 402HH and ARMS2 rs3750846, determination of TCC levels in the plasma, in vitro analysis on RPE function during exposure to patients' or control plasma as a complement source. Methods Genotyping, measurement of TCC concentrations, ARPE-19 cell culture, Ca2+ imaging, gene expression by qPCR, secretion by multiplex bead analysis of cell culture supernatants. Main outcome measures TCC concentration in plasma, intracellular free Ca2+, relative mRNA levels, cytokine secretion. Results TCC levels in the plasma of AMD patients were five times higher than in non-AMD controls but did not differ in plasma from carriers of the two risk alleles. Complement-evoked Ca2+ elevations in RPE cells differed between patients and controls with a significant correlation between TCC levels and peak amplitudes. Comparing the Ca2+ signals, only between the plasma of smokers and non-smokers, as well as heterozygous (CFH 402YH) and CFH 402HH patients, revealed differences in the late phase. Pre-stimulation with complement patients' plasma led to sensitization for complement reactions by RPE cells. Gene expression for surface molecules protective against TCC and pro-inflammatory cytokines increased after exposure to patients' plasma. Patients' plasma stimulated the secretion of pro-inflammatory cytokines in the RPE. Conclusion TCC levels were higher in AMD patients but did not depend on genetic risk factors. The Ca2+ responses to patients' plasma as second-messenger represent a shift of RPE cells to a pro-inflammatory phenotype and protection against TCC. We conclude a substantial role of high TCC plasma levels in AMD pathology.
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Affiliation(s)
- Catharina Busch
- Department of Ophthalmology, University Hospital Leipzig, Leipzig, Germany
| | - Saskia Rau
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Andjela Sekulic
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Luce Perie
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Christian Huber
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Miranda Gehrke
- Section of Immunobiology, Department of Ophthalmology, University Hospital, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Antonia M. Joussen
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
| | - Peter F. Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
- Institute of Microbiology, Friedrich-Schiller-University, Jena, Germany
| | - Gerhild Wildner
- Section of Immunobiology, Department of Ophthalmology, University Hospital, Ludwig-Maximilians-Universität (LMU) Munich, Munich, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität, Berlin Institute of Health, Humboldt-University, Berlin, Germany
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158
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Burri C, Salzmann S, Amstutz M, Hoffmann L, Považay B, Meier C, Frenz M. Investigation of the Influence of Pulse Duration and Application Mode on Microsecond Laser Microsurgery of the Retinal Pigment Epithelium. Life (Basel) 2023; 13:1314. [PMID: 37374097 DOI: 10.3390/life13061314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
Optical microsurgery confined to the retinal pigment epithelium (RPE) requires locally optimized laser parameters and reliable real-time feedback dosimetry (RFD) to prevent unwanted neuroretinal overexposure. This study aimed to compare pulses of different durations and application modes (single, ramp, burst). Moreover, optical coherence tomography (OCT)-based RFD was investigated in an ex vivo experiment, utilizing nine porcine eyes that were exposed to laser pulses of 8, 12, 16 and 20 µs duration (wavelength: 532 nm, exposure area: 90 × 90 µm2, radiant exposure: 247 to 1975 mJ/µm2). Simultaneously, time-resolved OCT M-scans were recorded (central wavelength: 870 nm, scan rate: 85 kHz) for RFD. Post irradiation, retinal changes were assessed with color fundus photography (CFP) and cross-sectional OCT B-scans. RPE cell damage was quantified via fluorescence-based cell viability assay and compared to the OCT dosimetry feedback. Our experiments indicate cumulative RPE damage for pulse bursts of 16 µs and 20 µs, whereas no cumulative effects were found for pulse durations of 8 µs and 12 µs applied in ramp mode. According to statistical analysis, OCT-RFD correctly detected RPE cell damage with 96% sensitivity and 97% specificity using pulses of 8 µs duration in ramp mode.
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Affiliation(s)
- Christian Burri
- Biomedical Photonics Group, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Simon Salzmann
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Mylène Amstutz
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Leonie Hoffmann
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Boris Považay
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Christoph Meier
- Institute for Human Centered Engineering (HuCE)-OptoLab, Bern University of Applied Sciences, Quellgasse 21, 2501 Biel, Switzerland
| | - Martin Frenz
- Biomedical Photonics Group, University of Bern, Sidlerstrasse 5, 3012 Bern, Switzerland
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159
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Pannetier P, Poulsen R, Gölz L, Coordes S, Stegeman H, Koegst J, Reger L, Braunbeck T, Hansen M, Baumann L. Reversibility of Thyroid Hormone System-Disrupting Effects on Eye and Thyroid Follicle Development in Zebrafish (Danio rerio) Embryos. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:1276-1292. [PMID: 36920003 DOI: 10.1002/etc.5608] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/13/2022] [Accepted: 03/10/2023] [Indexed: 05/27/2023]
Abstract
Early vertebrate development is partially regulated by thyroid hormones (THs). Environmental pollutants that interact with the TH system (TH system-disrupting chemicals [THSDCs]) can have massively disrupting effects on this essential phase. Eye development of fish is directly regulated by THs and can, therefore, be used as a thyroid-related endpoint in endocrine disruptor testing. To evaluate the effects of THSDC-induced eye malformations during early development, zebrafish (Danio rerio) embryos were exposed for 5 days postfertilization (dpf) to either propylthiouracil, a TH synthesis inhibitor, or tetrabromobisphenol A, which interacts with TH receptors. Subsequently, one half of the embryos were exposed further to the THSDCs until 8 dpf, while the other half of the embryos were raised in clean water for 3 days to check for reversibility of effects. Continued THSDC exposure altered eye size and pigmentation and induced changes in the cellular structure of the retina. This correlated with morphological alterations of thyroid follicles as revealed by use of a transgenic zebrafish line. Interestingly, effects were partly reversible after a recovery period as short as 3 days. Results are consistent with changes in TH levels measured in different tissues of the embryos, for example, in the eyes. The results show that eye development in zebrafish embryos is very sensitive to THSDC treatment but able to recover quickly from early exposure by effective repair mechanisms. Environ Toxicol Chem 2023;42:1276-1292. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Pauline Pannetier
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Rikke Poulsen
- Environmental Metabolomics Laboratory, Department of Environmental Science, University of Aarhus, Aarhus, Denmark
| | - Lisa Gölz
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Sara Coordes
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Hanna Stegeman
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Johannes Koegst
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Luisa Reger
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Thomas Braunbeck
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Martin Hansen
- Environmental Metabolomics Laboratory, Department of Environmental Science, University of Aarhus, Aarhus, Denmark
| | - Lisa Baumann
- Aquatic Ecology & Toxicology, Center for Organismal Studies, University of Heidelberg, Heidelberg, Germany
- Amsterdam Institute for Life and Environment (A-LIFE), Section on Environmental Health & Toxicology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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160
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Moon J, Zhou G, Jankowsky E, von Lintig J. Vitamin A deficiency compromises the barrier function of the retinal pigment epithelium. PNAS NEXUS 2023; 2:pgad167. [PMID: 37275262 PMCID: PMC10235913 DOI: 10.1093/pnasnexus/pgad167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/01/2023] [Indexed: 06/07/2023]
Abstract
A major cause for childhood blindness worldwide is attributed to nutritional vitamin A deficiency. Surprisingly, the molecular basis of the ensuing retinal degeneration has not been well defined. Abundant expression of the retinoid transporter STRA6 in the retinal pigment epithelium (RPE) and homeostatic blood levels of retinol-binding protein delay vitamin A deprivation of the mouse eyes. Hence, genetic dissection of STRA6 makes mice susceptible to nutritional manipulation of ocular retinoid status. We performed RNA-seq analyses and complemented the data with tests of visual physiology, ocular morphology, and retinoid biochemistry to compare eyes with different vitamin A status. Mild ocular vitamin A deficiency decreased transcripts of photoreceptor transduction pathway-related genes and increased transcripts of oxidative stress pathways. The response was associated with impaired visual sensitivity and an accumulation of fluorescent debris in the retina. Severe vitamin A deficiency did not only impair visual perception but also decreased transcripts of genes encoding cell adhesion and cellular junction proteins. This response altered cell morphology, resulted in significant changes in transport pathways of small molecules, and compromised the barrier function of the RPE. Together, our analyses characterize the molecular events underlying nutritional blindness in a novel mouse model and indicate that breakdown of the outer blood-retinal barrier contributes to retinal degeneration and photoreceptor cell death in severe vitamin A deficiency.
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Affiliation(s)
- Jean Moon
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gao Zhou
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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161
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Pinelli R, Ferrucci M, Biagioni F, Berti C, Bumah VV, Busceti CL, Puglisi-Allegra S, Lazzeri G, Frati A, Fornai F. Autophagy Activation Promoted by Pulses of Light and Phytochemicals Counteracting Oxidative Stress during Age-Related Macular Degeneration. Antioxidants (Basel) 2023; 12:1183. [PMID: 37371913 DOI: 10.3390/antiox12061183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/15/2023] [Accepted: 05/27/2023] [Indexed: 06/29/2023] Open
Abstract
The seminal role of autophagy during age-related macular degeneration (AMD) lies in the clearance of a number of reactive oxidative species that generate dysfunctional mitochondria. In fact, reactive oxygen species (ROS) in the retina generate misfolded proteins, alter lipids and sugars composition, disrupt DNA integrity, damage cell organelles and produce retinal inclusions while causing AMD. This explains why autophagy in the retinal pigment epithelium (RPE), mostly at the macular level, is essential in AMD and even in baseline conditions to provide a powerful and fast replacement of oxidized molecules and ROS-damaged mitochondria. When autophagy is impaired within RPE, the deleterious effects of ROS, which are produced in excess also during baseline conditions, are no longer counteracted, and retinal degeneration may occur. Within RPE, autophagy can be induced by various stimuli, such as light and naturally occurring phytochemicals. Light and phytochemicals, in turn, may synergize to enhance autophagy. This may explain the beneficial effects of light pulses combined with phytochemicals both in improving retinal structure and visual acuity. The ability of light to activate some phytochemicals may further extend such a synergism during retinal degeneration. In this way, photosensitive natural compounds may produce light-dependent beneficial antioxidant effects in AMD.
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Affiliation(s)
- Roberto Pinelli
- SERI, Switzerland Eye Research Institute, 6900 Lugano, Switzerland
| | - Michela Ferrucci
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Francesca Biagioni
- IRCCS, Istituto di Ricovero e Cura a Carattere Scientifico, Neuromed, 86077 Pozzili, Italy
| | - Caterina Berti
- SERI, Switzerland Eye Research Institute, 6900 Lugano, Switzerland
| | - Violet Vakunseth Bumah
- Department of Chemistry and Biochemistry, College of Sciences, San Diego State University, San Diego, CA 92182, USA
- Department of Chemistry and Physics, University of Tennessee, Martin, TN 38237, USA
| | - Carla Letizia Busceti
- IRCCS, Istituto di Ricovero e Cura a Carattere Scientifico, Neuromed, 86077 Pozzili, Italy
| | | | - Gloria Lazzeri
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
| | - Alessandro Frati
- IRCCS, Istituto di Ricovero e Cura a Carattere Scientifico, Neuromed, 86077 Pozzili, Italy
| | - Francesco Fornai
- Human Anatomy, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, 56126 Pisa, Italy
- IRCCS, Istituto di Ricovero e Cura a Carattere Scientifico, Neuromed, 86077 Pozzili, Italy
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162
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Si Z, Zheng Y, Zhao J. The Role of Retinal Pigment Epithelial Cells in Age-Related Macular Degeneration: Phagocytosis and Autophagy. Biomolecules 2023; 13:901. [PMID: 37371481 DOI: 10.3390/biom13060901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/11/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Age-related macular degeneration (AMD) causes vision loss in the elderly population. Dry AMD leads to the formation of Drusen, while wet AMD is characterized by cell proliferation and choroidal angiogenesis. The retinal pigment epithelium (RPE) plays a key role in AMD pathogenesis. In particular, helioreceptor renewal depends on outer segment phagocytosis of RPE cells, while RPE autophagy can protect cells from oxidative stress damage. However, when the oxidative stress burden is too high and homeostasis is disturbed, the phagocytosis and autophagy functions of RPE become damaged, leading to AMD development and progression. Hence, characterizing the roles of RPE cell phagocytosis and autophagy in the pathogenesis of AMD can inform the development of potential therapeutic targets to prevent irreversible RPE and photoreceptor cell death, thus protecting against AMD.
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Affiliation(s)
- Zhibo Si
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun 130000, China
| | - Yajuan Zheng
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun 130000, China
| | - Jing Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun 130000, China
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163
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Zhang J, Zhang T, Zeng S, Zhang X, Zhou F, Gillies MC, Zhu L. The Role of Nrf2/sMAF Signalling in Retina Ageing and Retinal Diseases. Biomedicines 2023; 11:1512. [PMID: 37371607 DOI: 10.3390/biomedicines11061512] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/10/2023] [Accepted: 05/19/2023] [Indexed: 06/29/2023] Open
Abstract
Age-related diseases, such as Parkinson's disease, Alzheimer's disease, cardiovascular diseases, cancers, and age-related macular disease, have become increasingly prominent as the population ages. Oxygen is essential for living organisms, but it may also cause disease when it is transformed into reactive oxygen species via biological processes in cells. Most of the production of ROS occurs in mitochondrial complexes I and III. The accumulation of ROS in cells causes oxidative stress, which plays a crucial role in human ageing and many diseases. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key antioxidant transcription factor that plays a central role in many diseases and ageing in general. It regulates many downstream antioxidative enzymes when cells are exposed to oxidative stress. A basic-region leucine zipper (bZIP) transcription factor, MAF, specifically the small MAF subfamily (sMAFs), forms heterodimers with Nrf2, which bind with Maf-recognition elements (MAREs) in response to oxidative stress. The role of this complex in the human retina remains unclear. This review summarises the current knowledge about Nrf2 and its downstream signalling, especially its cofactor-MAF, in ageing and diseases, with a focus on the retina. Since Nrf2 is the master regulator of redox homeostasis in cells, we hypothesise that targeting Nrf2 is a promising therapeutic approach for many age-related diseases.
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Affiliation(s)
- Jialing Zhang
- Save Sight Institute, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ting Zhang
- Save Sight Institute, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - Shaoxue Zeng
- Save Sight Institute, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xinyuan Zhang
- Department of Ocular Fundus Diseases, Beijing Tongren Eye Centre, Tongren Hospital, Capital Medical University, Beijing 100073, China
| | - Fanfan Zhou
- Faculty of Pharmacy, The University of Sydney, Sydney, NSW 2006, Australia
| | - Mark C Gillies
- Save Sight Institute, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ling Zhu
- Save Sight Institute, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
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164
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Swinkels D, Baes M. The essential role of docosahexaenoic acid and its derivatives for retinal integrity. Pharmacol Ther 2023; 247:108440. [PMID: 37201739 DOI: 10.1016/j.pharmthera.2023.108440] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 05/20/2023]
Abstract
The fatty acid composition of photoreceptor outer segment (POS) phospholipids diverges from other membranes, being highly enriched in polyunsaturated fatty acids (PUFAs). The most abundant PUFA is docosahexaenoic acid (DHA, C22:6n-3), an omega-3 PUFA that amounts to over 50% of the POS phospholipid fatty acid side chains. Interestingly, DHA is the precursor of other bioactive lipids such as elongated PUFAs and oxygenated derivatives. In this review, we present the current view on metabolism, trafficking and function of DHA and very long chain polyunsaturated fatty acids (VLC-PUFAs) in the retina. New insights on pathological features generated from PUFA deficient mouse models with enzyme or transporter defects and corresponding patients are discussed. Not only the neural retina, but also abnormalities in the retinal pigment epithelium are considered. Furthermore, the potential involvement of PUFAs in more common retinal degeneration diseases such as diabetic retinopathy, retinitis pigmentosa and age-related macular degeneration are evaluated. Supplementation treatment strategies and their outcome are summarized.
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Affiliation(s)
- Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, 3000 Leuven, Belgium.
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165
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Fernández-Espinosa G, Ruiz-Tabuenca C, Orduna-Hospital E, Pinilla I, Salgado-Remacha FJ. A Reliable Criterion for the Correct Delimitation of the Foveal Avascular Zone in Diabetic Patients. J Pers Med 2023; 13:jpm13050822. [PMID: 37240992 DOI: 10.3390/jpm13050822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 05/03/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Manual segmentation of the Foveal Avascular Zone (FAZ) has a high level of variability. Research into retinas needs coherent segmentation sets with low variability. METHODS Retinal optical coherence tomography angiography (OCTA) images from type-1 diabetes mellitus (DM1), type-2 diabetes mellitus (DM2) and healthy patients were included. Superficial (SCP) and deep (DCP) capillary plexus FAZs were manually segmented by different observers. After comparing the results, a new criterion was established to reduce variability in the segmentations. The FAZ area and acircularity were also studied. RESULTS The new segmentation criterion produces smaller areas (closer to the real FAZ) with lower variability than the different criteria of the explorers in both plexuses for the three groups. This was particularly noticeable for the DM2 group with damaged retinas. The acircularity values were also slightly reduced with the final criterion in all groups. The FAZ areas with lower values showed slightly higher acircularity values. We also have a consistent and coherent set of segmentations with which to continue our research. CONCLUSIONS Manual segmentations of FAZ are generally carried out with little attention to the consistency of the measurements. A novel criterion for segmenting the FAZ allows segmentations made by different observers to be more similar.
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Affiliation(s)
| | | | - Elvira Orduna-Hospital
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain
- Departamento de Física Aplicada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Isabel Pinilla
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain
- Department of Ophthalmology, Lozano Blesa University Hospital, 50009 Zaragoza, Spain
- Departamento de Cirugía, Universidad de Zaragoza, 50009 Zaragoza, Spain
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166
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Murakami T, Ishihara K, Terada N, Nishikawa K, Kawai K, Tsujikawa A. Pathological Neurovascular Unit Mapping onto Multimodal Imaging in Diabetic Macular Edema. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59050896. [PMID: 37241128 DOI: 10.3390/medicina59050896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/01/2023] [Accepted: 05/06/2023] [Indexed: 05/28/2023]
Abstract
Diabetic retinopathy is a form of diabetic microangiopathy, and vascular hyperpermeability in the macula leads to retinal thickening and concomitant reduction of visual acuity in diabetic macular edema (DME). In this review, we discuss multimodal fundus imaging, comparing the pathogenesis and interventions. Clinicians diagnose DME using two major criteria, clinically significant macular edema by fundus examination and center-involving diabetic macular edema using optical coherence tomography (OCT), to determine the appropriate treatment. In addition to fundus photography, fluorescein angiography (FA) is a classical modality to evaluate morphological and functional changes in retinal capillaries, e.g., microaneurysms, capillary nonperfusion, and fluorescein leakage. Recently, optical coherence tomography angiography (OCTA) has allowed us to evaluate the three-dimensional structure of the retinal vasculature and newly demonstrated that lamellar capillary nonperfusion in the deep layer is associated with retinal edema. The clinical application of OCT has accelerated our understanding of various neuronal damages in DME. Retinal thickness measured by OCT enables us to quantitatively assess therapeutic effects. Sectional OCT images depict the deformation of neural tissues, e.g., cystoid macular edema, serous retinal detachment, and sponge-like retinal swelling. The disorganization of retinal inner layers (DRIL) and foveal photoreceptor damage, biomarkers of neurodegeneration, are associated with visual impairment. Fundus autofluorescence derives from the retinal pigment epithelium (RPE) and its qualitative and quantitative changes suggest that the RPE damage contributes to the neuronal changes in DME. These clinical findings on multimodal imaging help to elucidate the pathology in the neurovascular units and lead to the next generation of clinical and translational research in DME.
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Affiliation(s)
- Tomoaki Murakami
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Kenji Ishihara
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Noriko Terada
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Keiichi Nishikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Kentaro Kawai
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan
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167
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Caioni G, Merola C, Bertolucci C, Lucon-Xiccato T, Savaşçı BB, Massimi M, Colasante M, Fioravanti G, Cacciola NA, Ippoliti R, d'Angelo M, Perugini M, Benedetti E. Early-life exposure to environmentally relevant concentrations of triclocarban impairs ocular development in zebrafish larvae. CHEMOSPHERE 2023; 324:138348. [PMID: 36898440 DOI: 10.1016/j.chemosphere.2023.138348] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 06/18/2023]
Abstract
Triclocarban (TCC), is an antimicrobial component in personal care products and it is one of the emerging contaminants since it has been detected in various environmental matrices. Its presence in human cord blood, breast milk, and maternal urine raised issues about its possible impact on development and increased concerns about the safety of daily exposure. This study aims to provide additional information about the effects of zebrafish early-life exposure to TCC on eye development and visual function. Zebrafish embryos were exposed to two concentrations of TCC (5 and 50 μg/L) for 4 days. TCC-mediated toxicity was assessed in larvae at the end of exposure and in the long term (20 days post fertilization; dpf), through different biological end-points. The experiments showed that TCC exposure influences the retinal architecture. In 4 dpf treated larvae, we found a less organized ciliary marginal zone, a decrease in the inner nuclear and inner plexiform layers, and a decrease in the retinal ganglion cell layer. Photoreceptor and inner plexiform layers showed an increase in 20 dpf larvae at lower and both concentrations, respectively. The expression levels of two genes involved in eye development (mitfb and pax6a) were both decreased at the concentration of 5 μg/L in 4 dpf larvae, and an increase in mitfb was observed in 5 μg/L-exposed 20 dpf larvae. Interestingly, 20 dpf larvae failed to discriminate between visual stimuli, demonstrating notable visual perception impairments due to compound. The results prompt us to hypothesize that early-life exposure to TCC may have severe and potentially long-term effect on zebrafish visual function.
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Affiliation(s)
- Giulia Caioni
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Carmine Merola
- Department of Bioscience and Agro-Food and Environmental Technology, University of Teramo, Teramo, Italy.
| | - Cristiano Bertolucci
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
| | - Tyrone Lucon-Xiccato
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
| | - Beste Başak Savaşçı
- Department of Bioscience and Agro-Food and Environmental Technology, University of Teramo, Teramo, Italy; Unit of Evolutionary Biology/Systematic Zoology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany.
| | - Mara Massimi
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Martina Colasante
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Giulia Fioravanti
- Department of Physical and Chemical Sciences University of L'Aquila, L'Aquila, Italy.
| | - Nunzio Antonio Cacciola
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy.
| | - Rodolfo Ippoliti
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Michele d'Angelo
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Monia Perugini
- Department of Bioscience and Agro-Food and Environmental Technology, University of Teramo, Teramo, Italy.
| | - Elisabetta Benedetti
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
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168
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Karema-Jokinen V, Koskela A, Hytti M, Hongisto H, Viheriälä T, Liukkonen M, Torsti T, Skottman H, Kauppinen A, Nymark S, Kaarniranta K. Crosstalk of protein clearance, inflammasome, and Ca 2+ channels in retinal pigment epithelium derived from age-related macular degeneration patients. J Biol Chem 2023:104770. [PMID: 37137441 DOI: 10.1016/j.jbc.2023.104770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 04/21/2023] [Accepted: 04/23/2023] [Indexed: 05/05/2023] Open
Abstract
Degeneration and/or dysfunction of retinal pigment epithelium (RPE) is generally detected as the formation of intra- and extracellular protein aggregates, called lipofuscin and drusen, respectively, in patients with age-related macular degeneration (AMD), the leading cause of blindness in the elderly population. These clinical hallmarks are linked to dysfunctional protein homeostasis and inflammation, and furthermore, are both regulated by changes in intracellular Ca2+ concentration. While many other cellular mechanisms have been considered in the investigations of AMD-RPE, there has been relatively little work on understanding the interactions of protein clearance, inflammation, and Ca2+ dynamics in disease pathogenesis. Here we established induced pluripotent stem cell-derived RPE from two patients with advanced AMD and from an age- and gender-matched control subject. We studied autophagy and inflammasome activation under disturbed proteostasis in these cell lines and investigated changes in their intracellular Ca2+ concentration and L-type voltage-gated Ca2+ channels. Our work demonstrated dysregulated autophagy and inflammasome activation in AMD-RPE accompanied by reduced intracellular free Ca2+ levels. Interestingly, we found currents through L-type voltage-gated Ca2+ channels to be diminished and showed these channels to be significantly localized to intracellular compartments in AMD-RPE. Taken together, the alterations in Ca2+ dynamics in AMD-RPE together with dysregulated autophagy and inflammasome activation indicate an important role for Ca2+ signaling in AMD pathogenesis, providing new avenues for the development of therapeutic approaches.
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Affiliation(s)
| | - Ali Koskela
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland
| | - Maria Hytti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Heidi Hongisto
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland; Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland
| | - Taina Viheriälä
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Mikko Liukkonen
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland
| | - Tommi Torsti
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Heli Skottman
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Anu Kauppinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Soile Nymark
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, Finland, Immuno-Ophthalmology, School of Pharmacy, University of Eastern Finland, Kuopio, Finland; Department of Molecular Genetics, University of Lodz, Lodz, Poland.
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169
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Dörschmann P, Thalenhorst T, Seeba C, Tischhöfer MT, Neupane S, Roider J, Alban S, Klettner A. Comparison of Fucoidans from Saccharina latissima Regarding Age-Related Macular Degeneration Relevant Pathomechanisms in Retinal Pigment Epithelium. Int J Mol Sci 2023; 24:7939. [PMID: 37175646 PMCID: PMC10178501 DOI: 10.3390/ijms24097939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/16/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
Fucoidans from brown algae are described as anti-inflammatory, antioxidative, and antiangiogenic. We tested two Saccharina latissima fucoidans (SL-FRO and SL-NOR) regarding their potential biological effects against age-related macular degeneration (AMD). Primary porcine retinal pigment epithelium (RPE), human RPE cell line ARPE-19, and human uveal melanoma cell line OMM-1 were used. Cell survival was assessed in tetrazolium assay (MTT). Oxidative stress assays were induced with erastin or H2O2. Supernatants were harvested to assess secreted vascular endothelial growth factor A (VEGF-A) in ELISA. Barrier function was assessed by measurement of trans-epithelial electrical resistance (TEER). Protectin (CD59) and retinal pigment epithelium-specific 65 kDa protein (RPE65) were evaluated in western blot. Polymorphonuclear elastase and complement inhibition assays were performed. Phagocytosis of photoreceptor outer segments was tested in a fluorescence assay. Secretion and expression of proinflammatory cytokines were assessed with ELISA and real-time PCR. Fucoidans were chemically analyzed. Neither toxic nor antioxidative effects were detected in ARPE-19 or OMM-1. Interleukin 8 gene expression was slightly reduced by SL-NOR but induced by SL-FRO in RPE. VEGF secretion was reduced in ARPE-19 by SL-FRO and in RPE by both fucoidans. Polyinosinic:polycytidylic acid induced interleukin 6 and interleukin 8 secretion was reduced by both fucoidans in RPE. CD59 expression was positively influenced by fucoidans, and they exhibited a complement and elastase inhibitory effect in cell-free assay. RPE65 expression was reduced by SL-NOR in RPE. Barrier function of RPE was transiently reduced. Phagocytosis ability was slightly reduced by both fucoidans in primary RPE but not in ARPE-19. Fucoidans from Saccharina latissima, especially SL-FRO, are promising agents against AMD, as they reduce angiogenic cytokines and show anti-inflammatory and complement inhibiting properties; however, potential effects on gene expression and RPE functions need to be considered for further research.
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Affiliation(s)
- Philipp Dörschmann
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany (A.K.)
| | - Tabea Thalenhorst
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany (A.K.)
| | - Charlotte Seeba
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany (A.K.)
| | | | - Sandesh Neupane
- Wyatt Technology Europe GmbH, Hochstrasse 12a, 56307 Dernbach, Germany
| | - Johann Roider
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany (A.K.)
| | - Susanne Alban
- Pharmaceutical Institute, University of Kiel, Gutenbergstr. 76, 24118 Kiel, Germany
| | - Alexa Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany (A.K.)
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170
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Tian Y, Shao J, Bai S, Xu Z, Bi C. Palmitic acid-induced microRNA-143-5p expression promotes the epithelial-mesenchymal transition of retinal pigment epithelium via negatively regulating JDP2. Aging (Albany NY) 2023; 15:3465-3479. [PMID: 37179125 PMCID: PMC10449279 DOI: 10.18632/aging.204684] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/17/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND The epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is the most crucial step in the etiopathogenesis of proliferative vitreoretinopathy. This study aimed to investigate the role of miR-143-5p in the EMT of RPE cells induced by palmitic acid (PA). METHODS ARPE-19 cells were treated with PA to induce EMT, followed by E-cadherin and α-smooth muscle actin (α-SMA) expression and the microRNA expression profile analyses. Subsequently, miR-143-5p mimics/inhibitors, and plasmids expressing its predicted target gene c-JUN-dimerization protein 2 (JDP2), were transfected in ARPE-19 cells using lipofectamine 3000, and followed by PA treatment. Their impacts on EMT were explored using wound healing and Western blot assays. Additionally, miR-143-5p mimics and JDP2-expressing plasmid were co-transfected into ARPE-19 cells and treated with PA to explore whether PA induced EMT of ARPE-19 cells via the miR-143-5p/JDP2 axis. RESULTS PA decreased E-cadherin expression and increased those of α-SMA and miR-143-5p. Inhibiting miR-143-5p suppressed the migration of ARPE-19 cells and altered the expressions of E-cadherin and α-SMA. However, additional PA treatment attenuated these alterations. JDP2 was a target of miR-143-5p. Overexpression of JDP2 inhibited the EMT of ARPE-19 cells, resulting in α-SMA downregulation and E-cadherin upregulation, which were reversed by additional PA treatment via inhibiting JDP2 expression. Overexpression of miR-143-5p reversed the effect of JDP2 on the EMT of ARPE-19 cells and additional PA treatment markedly enhanced the effect of miR-143-5p mimics. CONCLUSION PA promotes EMT of ARPE-19 cells via regulating the miR-143-5p/JDP2 axis, and these findings provide significant insights into the potential targeting of this axis to treat proliferative vitreoretinopathy.
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Affiliation(s)
- Yunlin Tian
- Department of Ophthalmology, Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an 710004, China
| | - Juan Shao
- Department of Ophthalmology, Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an 710004, China
| | - Shuwei Bai
- Department of Ophthalmology, Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an 710004, China
| | - Zhiguo Xu
- Department of Ophthalmology, Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an 710004, China
| | - Chunchao Bi
- Department of Ophthalmology, Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi'an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an 710004, China
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171
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Lee D, Hong HS. Substance P Alleviates Retinal Pigment Epithelium Dysfunction Caused by High Glucose-Induced Stress. Life (Basel) 2023; 13:life13051070. [PMID: 37240715 DOI: 10.3390/life13051070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
When the retina is constantly affected by high glucose (HG) due to diabetes, the barrier function of the retinal pigment epithelium (RPE) is impaired, accompanied by unnecessary vascularization. This eventually leads to the development of diabetic retinopathy (DR). This study investigated the recovery effect of substance P (SP) on RPE injured by HG. RPE was treated with HG for 24 h, and HG-induced cellular injuries were confirmed. SP was added to the dysfunctional RPE. Compared to RPE in low glucose (LG) conditions, HG-damaged RPE had large, fibrotic cell shapes, and its cellular viability decreased. HG treatment reduced tight junction protein expression levels and caused oxidative stress by interrupting the antioxidant system; this was followed by inflammatory factor intracellular adhesion molecule-1 (ICAM-1), Monocyte chemotactic protein-1 (MCP-1), and angiogenesis factor vascular endothelial growth factor (VEGF) expression. SP treatment contributed to RPE recovery by enhancing cell viability, tight junction protein expression, and RPE function under HG conditions, possibly by activating the Akt signaling pathway. Importantly, SP treatment reduced ICAM-1, MCP-1, and VEGF expression. Collectively, SP activated survival signals to suppress oxidative stress and improve retinal barrier function in RPE, accompanied by immune suppression. This suggests the possible application of SP to diabetic retinal injuries.
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Affiliation(s)
- Dahyeon Lee
- Department of Biomedical Science and Technology, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyun Sook Hong
- Department of Biomedical Science and Technology, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
- East-West Medical Research Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Kyung Hee Institute of Regenerative Medicine (KIRM), Medical Science Research Institute, Kyung Hee University Medical Center, Seoul 02447, Republic of Korea
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172
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Ignatova I, Frolov R, Nymark S. The retinal pigment epithelium displays electrical excitability and lateral signal spreading. BMC Biol 2023; 21:84. [PMID: 37069561 PMCID: PMC10111697 DOI: 10.1186/s12915-023-01559-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 03/10/2023] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND The non-neuronal retinal pigment epithelium (RPE) functions in intimate association with retinal photoreceptors, performing a multitude of tasks critical for maintaining retinal homeostasis and collaborating with retinal glial cells to provide metabolic support and ionic buffering. Accordingly, the RPE has recently been shown to display dynamic properties mediated by an array of ion channels usually more characteristic of astrocytes and excitable cells. The recent discovery of canonical voltage-activated Na+ channels in the RPE and their importance for phagocytosis of photoreceptor outer segments raises a question about their electrogenic function. Here, we performed a detailed electrophysiological analysis related to the functioning of these channels in human embryonic stem cell (hESC)-derived RPE. RESULTS Our studies examining the electrical properties of the hESC-RPE revealed that its membrane mainly displays passive properties in a broad voltage range, with the exception of depolarization-induced spikes caused by voltage-activated Na+ current (INa). Spike amplitude depended on the availability of INa and spike kinetics on the membrane time constant, and the spikes could be largely suppressed by TTX. Membrane resistance fluctuated rapidly and strongly, repeatedly changing over the course of recordings and causing closely correlated fluctuations in resting membrane potential. In a minority of cells, we found delayed secondary INa-like inward currents characterized by comparatively small amplitudes and slow kinetics, which produced secondary depolarizing spikes. Up to three consecutive delayed inward current waves were detected. These currents could be rapidly and reversibly augmented by applying L-type Ca2+ channel blocker nifedipine to diminish influx of calcium and thus increase gap junctional conductance. CONCLUSIONS This work shows, for the first time, that INa and INa-mediated voltage spikes can spread laterally through gap junctions in the monolayer of cells that are traditionally considered non-excitable. Our findings support a potential role of the RPE that goes beyond giving homeostatic support to the retina.
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Affiliation(s)
- Irina Ignatova
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | | | - Soile Nymark
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
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173
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Li F, Lei C, Gong K, Bai S, Sun L. Palmitic acid promotes human retinal pigment epithelial cells migration by upregulating miR-222 expression and inhibiting NUMB. Aging (Albany NY) 2023; 15:9341-9357. [PMID: 37566749 PMCID: PMC10564421 DOI: 10.18632/aging.204647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 03/24/2023] [Indexed: 08/13/2023]
Abstract
High glucose promotes retinal pigment epithelial cell (RPEC) migration. However, the underlying molecular mechanisms explaining how high fatty acid levels affect RPEC migration remain largely unknown. We investigated whether and how palmitic acid (PA) impacts the migration of human RPEC cell line ARPE-19. ARPE-19 cells were treated with varying doses of palmitic acid, and the RPEC migration was evaluated by scratch and transwell migration assays. Cell viability was determined by the CCK-8 method. The levels of epithelial-mesenchymal transition (EMT)-associated proteins, including E-cadherin, vimentin, MMP2, and MMP3, were evaluated by western blot. The microRNAs and mRNAs levels were assessed by quantitative PCR. miRNA targets were predicted with online tools and validated with the luciferase reporter assay. miRNA mimics, inhibitors, and siRNA oligos were used to perform gain-of-function and loss-of-function studies. We found that PA increased viability of ARPE-19 cells, promoted their migration and EMT. PA decreased E-cadherin protein expression, and increased vimentin, MMP2, and MMP3 protein levels. Additionally, PA increased miR-222 expression in ARPE-19 cells, and functionally blocking miR-222 suppressed the PA-induced RPEC migration and EMT. NUMB was identified as a downstream target of miR-222, and NUMB knockdown abolished the effects of PA on promoting the migration and EMT of ARPE-19 cells. Therefore, PA promotes human RPEC migration by upregulating miR-222 expression and downregulating NUMB. This study unravels a novel PA-miR-222-NUMB axis that can be potentially targeted for therapy of high fat acid-related ocular diseases.
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Affiliation(s)
- Fengzhi Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710004, China
| | - Chunling Lei
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710004, China
| | - Ke Gong
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710004, China
| | - Shuwei Bai
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710004, China
| | - Lianyi Sun
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated Guangren Hospital, School of Medicine, Xi’an Jiaotong University, Xi’an, Shaanxi 710004, China
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174
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Sripathi SR, Hu MW, Turaga RC, Mikeasky R, Satyanarayana G, Cheng J, Duan Y, Maruotti J, Wahlin KJ, Berlinicke CA, Qian J, Esumi N, Zack DJ. IKKβ Inhibition Attenuates Epithelial Mesenchymal Transition of Human Stem Cell-Derived Retinal Pigment Epithelium. Cells 2023; 12:1155. [PMID: 37190063 PMCID: PMC10136838 DOI: 10.3390/cells12081155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/08/2023] [Accepted: 03/09/2023] [Indexed: 05/17/2023] Open
Abstract
Epithelial-mesenchymal transition (EMT), which is well known for its role in embryonic development, malignant transformation, and tumor progression, has also been implicated in a variety of retinal diseases, including proliferative vitreoretinopathy (PVR), age-related macular degeneration (AMD), and diabetic retinopathy. EMT of the retinal pigment epithelium (RPE), although important in the pathogenesis of these retinal conditions, is not well understood at the molecular level. We and others have shown that a variety of molecules, including the co-treatment of human stem cell-derived RPE monolayer cultures with transforming growth factor beta (TGF-β) and the inflammatory cytokine tumor necrosis factor alpha (TNF-α), can induce RPE-EMT; however, small molecule inhibitors of RPE-EMT have been less well studied. Here, we demonstrate that BAY651942, a small molecule inhibitor of nuclear factor kapa-B kinase subunit beta (IKKβ) that selectively targets NF-κB signaling, can modulate TGF-β/TNF-α-induced RPE-EMT. Next, we performed RNA-seq studies on BAY651942 treated hRPE monolayers to dissect altered biological pathways and signaling events. Further, we validated the effect of IKKβ inhibition on RPE-EMT-associated factors using a second IKKβ inhibitor, BMS345541, with RPE monolayers derived from an independent stem cell line. Our data highlights the fact that pharmacological inhibition of RPE-EMT restores RPE identity and may provide a promising approach for treating retinal diseases that involve RPE dedifferentiation and EMT.
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Affiliation(s)
- Srinivasa R. Sripathi
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Henderson Ocular Stem Cell Laboratory, Retina Foundation of the Southwest, Dallas, TX 75231, USA
| | - Ming-Wen Hu
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ravi Chakra Turaga
- Caris Life Sciences, 350 W Washington St., Tempe, AZ 85281, USA
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
| | - Rebekah Mikeasky
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ganesh Satyanarayana
- Department of Biology, Georgia State University, Atlanta, GA 30303, USA
- Emory Eye Center, Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - Jie Cheng
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yukan Duan
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Karl J. Wahlin
- Shiley Eye Institute, University of California, San Diego, CA 92093, USA
| | - Cynthia A. Berlinicke
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Jiang Qian
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Noriko Esumi
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Donald J. Zack
- Department of Ophthalmology, Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Institute for NanoBioTechnology, Johns Hopkins University, Whiting School of Engineering, Baltimore, MD 21218, USA
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175
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Umapathy A, Torten G, Paniagua AE, Chung J, Tomlinson M, Lim C, Williams DS. Spatiotemporal Live-Cell Analysis of Photoreceptor Outer Segment Membrane Ingestion by the Retinal Pigment Epithelium Reveals Actin-Regulated Scission. J Neurosci 2023; 43:2653-2664. [PMID: 36878726 PMCID: PMC10089248 DOI: 10.1523/jneurosci.1726-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 03/08/2023] Open
Abstract
The photoreceptor outer segment (OS) is the phototransductive organelle in the vertebrate retina. OS tips are regularly ingested and degraded by the adjacent retinal pigment epithelium (RPE), offsetting the addition of new disk membrane at the base of the OS. This catabolic role of the RPE is essential for photoreceptor health, with defects in ingestion or degradation underlying different forms of retinal degeneration and blindness. Although proteins required for OS tip ingestion have been identified, spatiotemporal analysis of the ingestion process in live RPE cells is lacking; hence, the literature reflects no common understanding of the cellular mechanisms that affect ingestion. We imaged live RPE cells from mice (both sexes) to elucidate the ingestion events in real time. Our imaging revealed roles for f-actin dynamics and specific dynamic localizations of two BAR (Bin-Amphiphysin-Rvs) proteins, FBP17 and AMPH1-BAR, in shaping the RPE apical membrane as it surrounds the OS tip. Completion of ingestion was observed to occur by scission of the OS tip from the remainder of the OS, with a transient concentration of f-actin forming around the site of imminent scission. Actin dynamics were also required for regulating the size of the ingested OS tip, and the time course of the overall ingestion process. The size of the ingested tip is consistent with the term "phagocytosis." However, phagocytosis usually refers to engulfment of an entire particle or cell, whereas our observations of OS tip scission indicate a process that is more specifically described as "trogocytosis," in which one cell "nibbles" another cell.SIGNIFICANCE STATEMENT The ingestion of the photoreceptor outer segment (OS) tips by the retinal pigment epithelium (RPE) is a dynamic cellular process that has fascinated scientists for 60 years. Yet its molecular mechanisms had not been addressed in living cells. We developed a live-cell imaging approach to investigate OS tip ingestion, and focused on the dynamic participation of actin filaments and membrane-shaping BAR proteins. We observed scission of OS tips for the first time, and were able to monitor local changes in protein concentration preceding, during, and following scission. Our approach revealed that actin filaments were concentrated at the site of OS scission and were required for regulating the size of the ingested OS tip and the time course of the ingestion process.
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Affiliation(s)
- Ankita Umapathy
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Gil Torten
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Antonio E Paniagua
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Julie Chung
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Madeline Tomlinson
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - Caleb Lim
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute, and Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095
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176
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Dörschmann P, Akkurt H, Kopplin G, Mikkelsen MD, Meyer AS, Roider J, Klettner A. Establishment of specific age-related macular degeneration relevant gene expression panels using porcine retinal pigment epithelium for assessing fucoidan bioactivity. Exp Eye Res 2023; 231:109469. [PMID: 37037364 DOI: 10.1016/j.exer.2023.109469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/24/2023] [Accepted: 04/06/2023] [Indexed: 04/12/2023]
Abstract
PURPOSE Age-related macular degeneration (AMD) is the leading cause of severe vision loss in industrialized nations. Important factors in pathogenesis are oxidative stress, inflammation, and, in the wet form of AMD, angiogenesis. Fucoidans, sulfated polysaccharides from brown algae, may have antioxidant, anti-inflammatory, and antiangiogenic effects. In this study, we established specific gene expression panels for inflammation, oxidative stress and angiogenesis in porcine retinal pigment epithelium (RPE), and investigated the effect of fucoidans on gene expression under different noxious agents. METHODS Primary porcine RPE cells cultured for at least 14 days were used. Using viability assays with tetrazolium bromide and real-time polymerase chain reaction of marker genes, positive controls were established for appropriate concentrations and exposure times of selected noxious agents (lipopolysaccharide (LPS), H2O2, CoCl2). Three different AMD relevant gene panels specific for porcine RPE for inflammation, oxidative stress, and angiogenesis were established, and the influence of fucoidans (mainly Fucus vesiculosus; FV) on gene expression was investigated. RESULTS The following was shown by gene expression analyses: (1) Inflammation panel: Expression of 18 genes was affected under LPS (three days). Among them, LPS increased genes for interleukin 1 receptor 2, interleukin 8, cyclooxygenase-2 and vascular cell adhesion protein 1 expression which were diminished when FV was present. (2) Oxidative stress panel: Under stimulation of H2O2 (one day) and LPS (one day), expression of a total of 15 genes was affected. LPS induced increase in genes for superoxide dismutase-1, C-X-C motif chemokine 10, and CC chemokine ligand-5 expression was not detected when FV was present. (3) Angiogenesis panel: Under stimulation with CoCl2 (three days) expression of six genes was affected, with the increase of genes for angiopoietin 2, vascular endothelial growth factor receptor-1, and follistatin being diminished when FV was present. CONCLUSION Three specific gene expression panels for porcine RPE that map genes for three of the major pathological factors of AMD, inflammation, oxidative stress, and angiogenesis, were established. Further, we demonstrated that fucoidans can reduce stress related gene activation in all of these three major pathogenic pathways. This study is another indication that fucoidans can act on different pathomechanisms of AMD simultaneously, which provides further evidence for fucoidans as a possible drug for treatment and prevention of AMD.
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Affiliation(s)
- Philipp Dörschmann
- Kiel University, University Medical Center, Department of Ophthalmology, Arnold-Heller-Str. 3, Haus B2, 24105, Kiel, Germany.
| | - Hubeydullah Akkurt
- Kiel University, University Medical Center, Department of Ophthalmology, Arnold-Heller-Str. 3, Haus B2, 24105, Kiel, Germany
| | - Georg Kopplin
- Alginor ASA, Haraldsgata 162, 5525, Haugesund, Norway
| | | | - Anne S Meyer
- Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark
| | - Johann Roider
- Kiel University, University Medical Center, Department of Ophthalmology, Arnold-Heller-Str. 3, Haus B2, 24105, Kiel, Germany
| | - Alexa Klettner
- Kiel University, University Medical Center, Department of Ophthalmology, Arnold-Heller-Str. 3, Haus B2, 24105, Kiel, Germany
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177
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Dhingra A, Tobias JW, Philp NJ, Boesze-Battaglia K. Transcriptomic Changes Predict Metabolic Alterations in LC3 Associated Phagocytosis in Aged Mice. Int J Mol Sci 2023; 24:6716. [PMID: 37047689 PMCID: PMC10095460 DOI: 10.3390/ijms24076716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
LC3b (Map1lc3b) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b to promote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes, such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells, utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis, and neuroprotection. In a mouse model of retinal lipid steatosis-mice lacking LC3b (LC3b-/-), we observed increased lipid deposition, metabolic dysregulation, and enhanced inflammation. Herein, we present a non-biased approach to determine if loss of LAP mediated processes modulate the expression of various genes related to metabolic homeostasis, lipid handling, and inflammation. A comparison of the RPE transcriptome of WT and LC3b-/- mice revealed 1533 DEGs, with ~73% upregulated and 27% downregulated. Enriched gene ontology (GO) terms included inflammatory response (upregulated DEGs), fatty acid metabolism, and vascular transport (downregulated DEGs). Gene set enrichment analysis (GSEA) identified 34 pathways; 28 were upregulated (dominated by inflammation/related pathways) and 6 were downregulated (dominated by metabolic pathways). Analysis of additional gene families identified significant differences for genes in the solute carrier family, RPE signature genes, and genes with a potential role in age-related macular degeneration. These data indicate that loss of LC3b induces robust changes in the RPE transcriptome contributing to lipid dysregulation and metabolic imbalance, RPE atrophy, inflammation, and disease pathophysiology.
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Affiliation(s)
- Anuradha Dhingra
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John W. Tobias
- Penn Genomics and Sequencing Core, Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nancy J. Philp
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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178
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Yu H, Wang F, Teodoro G, Chen F, Guo X, Nickerson JM, Kong J. Self-supervised semantic segmentation of retinal pigment epithelium cells in flatmount fluorescent microscopy images. Bioinformatics 2023; 39:btad191. [PMID: 37067486 PMCID: PMC10139776 DOI: 10.1093/bioinformatics/btad191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/23/2023] [Accepted: 04/10/2023] [Indexed: 04/18/2023] Open
Abstract
MOTIVATION Morphological analyses with flatmount fluorescent images are essential to retinal pigment epithelial (RPE) aging studies and thus require accurate RPE cell segmentation. Although rapid technology advances in deep learning semantic segmentation have achieved great success in many biomedical research, the performance of these supervised learning methods for RPE cell segmentation is still limited by inadequate training data with high-quality annotations. RESULTS To address this problem, we develop a Self-Supervised Semantic Segmentation (S4) method that utilizes a self-supervised learning strategy to train a semantic segmentation network with an encoder-decoder architecture. We employ a reconstruction and a pairwise representation loss to make the encoder extract structural information, while we create a morphology loss to produce the segmentation map. In addition, we develop a novel image augmentation algorithm (AugCut) to produce multiple views for self-supervised learning and enhance the network training performance. To validate the efficacy of our method, we applied our developed S4 method for RPE cell segmentation to a large set of flatmount fluorescent microscopy images, we compare our developed method for RPE cell segmentation with other state-of-the-art deep learning approaches. Compared with other state-of-the-art deep learning approaches, our method demonstrates better performance in both qualitative and quantitative evaluations, suggesting its promising potential to support large-scale cell morphological analyses in RPE aging investigations. AVAILABILITY AND IMPLEMENTATION The codes and the documentation are available at: https://github.com/jkonglab/S4_RPE.
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Affiliation(s)
- Hanyi Yu
- Department of Computer Science, Emory University, Atlanta, GA 30322, USA
| | - Fusheng Wang
- Department of Computer Science, Stony Brook University, Stony Brook, NY 11794, USA
| | - George Teodoro
- Department of Computer Science, Federal University of Minas Gerais, Belo Horizonte 31270, Brazil
| | - Fan Chen
- Huangpu Branch, Guangzhou Urban Planning & Design Survey Research Institute, Guangzhou 510060, China
| | - Xiaoyuan Guo
- Department of Computer Science, Emory University, Atlanta, GA 30322, USA
| | - John M Nickerson
- Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - Jun Kong
- Department of Computer Science, Emory University, Atlanta, GA 30322, USA
- Department of Mathematics and Statistics, Georgia State University, Atlanta, GA 30303, USA
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179
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Dörschmann P, Seeba C, Thalenhorst T, Roider J, Klettner A. Anti-inflammatory properties of antiangiogenic fucoidan in retinal pigment epithelium cells. Heliyon 2023; 9:e15202. [PMID: 37123974 PMCID: PMC10130777 DOI: 10.1016/j.heliyon.2023.e15202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 05/02/2023] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial disease in which angiogenesis, oxidative stress and inflammation are important contributing factors. In this study, we investigated the anti-inflammatory effects of a fucoidan from the brown algae Fucus vesiculosus (FV) in primary porcine RPE cells. Inflammation was induced by lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C), Pam2CSK4 (Pam), or tumor necrosis factor alpha (TNF-α). Cell viability was tested with thiazolyl blue tetrazolium bromide (MTT) test, barrier function by measuring transepithelial electric resistance (TEER), interleukin 6 (IL-6) and interleukin 8 (IL-8) secretion in ELISA, retinal pigment epithelium-specific 65 kDa protein (RPE65) and protectin (CD59) expression in Western blot, gene expression with quantitative polymerase chain reaction (qPCR) (IL6, IL8, MERTK, PIK3CA), and phagocytotic activity in a microscopic assay. FV fucoidan did not influence RPE cell viability. FV fucoidan reduced the Poly I:C proinflammatory cytokine secretion of IL-6 and IL-8. In addition, it decreased the expression of IL-6 and IL-8 in RT-PCR. LPS and TNF-α reduced the expression of CD59 in Western blot, this reduction was lost under FV fucoidan treatment. Also, LPS and TNF-α reduced the expression of visual cycle protein RPE65, this reduction was again lost under FV fucoidan treatment. Furthermore, the significant reduction of barrier function after Poly I:C stimulation is ameliorated by FV fucoidan. Concerning phagocytosis, however, the inflammation-induced reduction was not improved by FV fucoidan. FV and proinflammatory milieu did not relevantly influence phagocytosis relevant gene expression either. In conclusion, we show that fucoidan from FV can reduce proinflammatory stimulation in RPE induced by toll-like receptor 3 (TLR-3) activation and is of high interest as a potential compound for early AMD treatment.
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180
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Piskova T, Kozyrina AN, Di Russo J. Mechanobiological implications of age-related remodelling in the outer retina. BIOMATERIALS ADVANCES 2023; 147:213343. [PMID: 36801797 DOI: 10.1016/j.bioadv.2023.213343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/01/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023]
Abstract
The outer retina consists of the light-sensitive photoreceptors, the pigmented epithelium, and the choroid, which interact in a complex manner to sustain homeostasis. The organisation and function of these cellular layers are mediated by the extracellular matrix compartment named Bruch's membrane, situated between the retinal epithelium and the choroid. Like many tissues, the retina experiences age-related structural and metabolic changes, which are relevant for understanding major blinding diseases of the elderly, such as age-related macular degeneration. Compared with other tissues, the retina mainly comprises postmitotic cells, making it less able to maintain its mechanical homeostasis over the years functionally. Aspects of retinal ageing, like the structural and morphometric changes of the pigment epithelium and the heterogenous remodelling of the Bruch's membrane, imply changes in tissue mechanics and may affect functional integrity. In recent years, findings in the field of mechanobiology and bioengineering highlighted the importance of mechanical changes in tissues for understanding physiological and pathological processes. Here, we review the current knowledge of age-related changes in the outer retina from a mechanobiological perspective, aiming to generate food for thought for future mechanobiology studies in the outer retina.
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Affiliation(s)
- Teodora Piskova
- Interdisciplinary Centre for Clinical Research, RWTH Aachen University, Pauwelstrasse 30, 52074 Aachen, Germany; Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Aleksandra N Kozyrina
- Interdisciplinary Centre for Clinical Research, RWTH Aachen University, Pauwelstrasse 30, 52074 Aachen, Germany; Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
| | - Jacopo Di Russo
- Interdisciplinary Centre for Clinical Research, RWTH Aachen University, Pauwelstrasse 30, 52074 Aachen, Germany; Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstrasse 50, 52074 Aachen, Germany.
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181
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Blue Light Exposure: Ocular Hazards and Prevention-A Narrative Review. Ophthalmol Ther 2023; 12:755-788. [PMID: 36808601 PMCID: PMC9938358 DOI: 10.1007/s40123-023-00675-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/01/2023] [Indexed: 02/21/2023] Open
Abstract
INTRODUCTION Exposure to blue light has seriously increased in our environment since the arrival of light emitting diodes (LEDs) and, in recent years, the proliferation of digital devices rich in blue light. This raises some questions about its potential deleterious effects on eye health. The aim of this narrative review is to provide an update on the ocular effects of blue light and to discuss the efficiency of methods of protection and prevention against potential blue light-induced ocular injury. METHODS The search of relevant English articles was conducted in PubMed, Medline, and Google Scholar databases until December 2022. RESULTS Blue light exposure provokes photochemical reactions in most eye tissues, in particular the cornea, the lens, and the retina. In vitro and in vivo studies have shown that certain exposures to blue light (depending on the wavelength or intensity) can cause temporary or permanent damage to some structures of the eye, especially the retina. However, currently, there is no evidence that screen use and LEDs in normal use are deleterious to the human retina. Regarding protection, there is currently no evidence of a beneficial effect of blue blocking lenses for the prevention of eye diseases, in particular age-related macular degeneration (AMD). In humans, macular pigments (composed of lutein and zeaxanthin) represent a natural protection by filtering blue light, and can be increased through increased intake from foods or food supplements. These nutrients are associated with lower risk for AMD and cataract. Antioxidants such as vitamins C, E, or zinc might also contribute to the prevention of photochemical ocular damage by preventing oxidative stress. CONCLUSION Currently, there is no evidence that LEDs in normal use at domestic intensity levels or in screen devices are retinotoxic to the human eye. However, the potential toxicity of long-term cumulative exposure and the dose-response effect are currently unknown.
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Dhingra A, Tobias JW, Philp NJ, Boesze-Battaglia K. Transcriptomic changes predict metabolic alterations in LC3 associated phagocytosis in aged mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532586. [PMID: 36993501 PMCID: PMC10054970 DOI: 10.1101/2023.03.14.532586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
Abstract
LC3b ( Map1lc3b ) plays an essential role in canonical autophagy and is one of several components of the autophagy machinery that mediates non-canonical autophagic functions. Phagosomes are often associated with lipidated LC3b, to pro-mote phagosome maturation in a process called LC3-associated phagocytosis (LAP). Specialized phagocytes such as mammary epithelial cells, retinal pigment epithelial (RPE) cells, and sertoli cells utilize LAP for optimal degradation of phagocytosed material, including debris. In the visual system, LAP is critical to maintain retinal function, lipid homeostasis and neuroprotection. In a mouse model of retinal lipid steatosis - mice lacking LC3b ( LC3b -/- ), we observed increased lipid deposition, metabolic dysregulation and enhanced inflammation. Herein we present a non-biased approach to determine if loss of LAP mediated processes modulate the expression of various genes related to metabolic homeostasis, lipid handling, and inflammation. A comparison of the RPE transcriptome of WT and LC3b -/- mice revealed 1533 DEGs, with ~73% upregulated and 27% down-regulated. Enriched gene ontology (GO) terms included inflammatory response (upregulated DEGs), fatty acid metabolism and vascular transport (downregulated DEGs). Gene set enrichment analysis (GSEA) identified 34 pathways; 28 were upregulated (dominated by inflammation/related pathways) and 6 were downregulated (dominated by metabolic pathways). Analysis of additional gene families identified significant differences for genes in the solute carrier family, RPE signature genes, and genes with potential role in age-related macular degeneration. These data indicate that loss of LC3b induces robust changes in the RPE transcriptome contributing to lipid dysregulation and metabolic imbalance, RPE atrophy, inflammation, and disease pathophysiology.
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Xu P, Chen Z, Ma J, Shan Y, Wang Y, Xie B, Zheng D, Guo F, Song X, Gao G, Ye K, Liu Y, Pan G, Jiang B, Peng F, Zhong X. Biallelic CLCN2 mutations cause retinal degeneration by impairing retinal pigment epithelium phagocytosis and chloride channel function. Hum Genet 2023; 142:577-593. [PMID: 36964785 DOI: 10.1007/s00439-023-02531-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/06/2023] [Indexed: 03/26/2023]
Abstract
CLCN2 encodes a two-pore homodimeric chloride channel protein (CLC-2) that is widely expressed in human tissues. The association between Clcn2 and the retina is well-established in mice, as loss-of-function of CLC-2 can cause retinopathy in mice; however, the ocular phenotypes caused by CLCN2 mutations in humans and the underlying mechanisms remain unclear. The present study aimed to define the ocular features and reveal the pathogenic mechanisms of CLCN2 variants associated with retinal degeneration in humans using an in vitro overexpression system, as well as patient-induced pluripotent stem cell (iPSC)-derived retinal pigment epithelium (RPE) cells and retinal organoids (ROs). A patient carrying the homozygous c.2257C > T (p.R753X) nonsense CLCN2 mutation was followed up for > 6 years. Ocular features were comprehensively characterized with multimodality imaging and functional examination. The patient presented with severe bilateral retinal degeneration with loss of photoreceptor and RPE. In vitro, mutant CLC-2 maintained the correct subcellular localization, but with reduced channel function compared to wild-type CLC-2 in HEK293T cells. Additionally, patient iPSC-derived RPE cells carrying the CLCN2 mutation exhibited dysfunctional ClC-2 chloride channels and outer segment phagocytosis. Notably, these functions were rescued following the repair of the CLCN2 mutation using the CRISPR-Cas9 system. However, this variant did not cause significant photoreceptor degeneration in patient-derived ROs, indicating that dysfunctional RPE is likely the primary cause of biallelic CLCN2 variant-mediated retinopathy. This study is the first to establish the confirmatory ocular features of human CLCN2-related retinal degeneration, and reveal a pathogenic mechanism associated with biallelic CLCN2 variants, providing new insights into the cause of inherited retinal dystrophies.
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Affiliation(s)
- Ping Xu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Zhuolin Chen
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China
| | - Jianchi Ma
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Yongli Shan
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China, Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Yuan Wang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Bingbing Xie
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Dandan Zheng
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Fuying Guo
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Xiaojing Song
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Guanjie Gao
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Ke Ye
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China
| | - Guangjin Pan
- CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China, Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China
| | - Bin Jiang
- Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, China
| | - Fuhua Peng
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
| | - Xiufeng Zhong
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, China.
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Ray S, Gurung P, Manning RS, Kravchuk A, Singhvi A. Neuron cilia constrain glial regulators to microdomains around distal neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.18.533255. [PMID: 36993507 PMCID: PMC10055228 DOI: 10.1101/2023.03.18.533255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Each glia interacts with multiple neurons, but the fundamental logic of whether it interacts with all equally remains unclear. We find that a single sense-organ glia modulates different contacting neurons distinctly. To do so, it partitions regulatory cues into molecular microdomains at specific neuron contact-sites, at its delimited apical membrane. For one glial cue, K/Cl transporter KCC-3, microdomain-localization occurs through a two-step, neuron-dependent process. First, KCC-3 shuttles to glial apical membranes. Second, some contacting neuron cilia repel it, rendering it microdomain-localized around one distal neuron-ending. KCC-3 localization tracks animal aging, and while apical localization is sufficient for contacting neuron function, microdomain-restriction is required for distal neuron properties. Finally, we find the glia regulates its microdomains largely independently. Together, this uncovers that glia modulate cross-modal sensor processing by compartmentalizing regulatory cues into microdomains. Glia across species contact multiple neurons and localize disease-relevant cues like KCC-3. Thus, analogous compartmentalization may broadly drive how glia regulate information processing across neural circuits.
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Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Neuroscience Graduate Program, University of Washington, Seattle, WA
| | - Pralaksha Gurung
- Neuroscience Graduate Program, University of Washington, Seattle, WA
| | - R. Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
| | - Alexandra Kravchuk
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- University of Washington School of Medicine, WA 98195
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109
- Department of Biological Structure, University of Washington School of Medicine, WA 98195
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185
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Ma X, Chen H, Jian S, He J, Liu Y, Han S, Chang L, Li P, Chen YA, Liu X, Hu X, Chen Y, Hou L. DAPL1 deficiency in mice impairs antioxidant defenses in the RPE and leads to retinal degeneration with AMD-like features. Redox Biol 2023; 62:102675. [PMID: 36933392 PMCID: PMC10031543 DOI: 10.1016/j.redox.2023.102675] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/08/2023] [Accepted: 03/14/2023] [Indexed: 03/16/2023] Open
Abstract
The decreased antioxidant capacity in the retinal pigment epithelium (RPE) is the hallmark of retinal degenerative diseases including age-related macular degeneration (AMD). Nevertheless, the exact regulatory mechanisms underlying the pathogenesis of retinal degenerations remain largely unknown. Here we show in mice that deficiencies in Dapl1, a susceptibility gene for human AMD, impair the antioxidant capacity of the RPE and lead to age-related retinal degeneration in the 18-month-old mice homozygous for a partial deletion of Dapl1. Dapl1-deficiency is associated with a reduction of the RPE's antioxidant capacity, and experimental re-expression of Dapl1 reverses this reduction and protects the retina from oxidative damage. Mechanistically, DAPL1 directly binds the transcription factor E2F4 and inhibits the expression of MYC, leading to upregulation of the transcription factor MITF and its targets NRF2 and PGC1α, both of which regulate the RPE's antioxidant function. When MITF is experimentally overexpressed in the RPE of DAPL1 deficient mice, antioxidation is restored and retinas are protected from degeneration. These findings suggest that the DAPL1-MITF axis functions as a novel regulator of the antioxidant defense system of the RPE and may play a critical role in the pathogenesis of age-related retinal degenerative diseases.
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Affiliation(s)
- Xiaoyin Ma
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China; State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003, China.
| | - Huaicheng Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China; Department of Ophthalmology, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, 322000, China
| | - Shuhui Jian
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China; The Affiliated Eye Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Junhao He
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Youjia Liu
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Shuxian Han
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Lifu Chang
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Pingping Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Ying-Ao Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Xiaoyan Liu
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Xiaojuan Hu
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China
| | - Yu Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China; State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003, China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, China; State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003, China.
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186
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Hypoxia-induced transcriptional differences in African and Asian versus European diabetic cybrids. Sci Rep 2023; 13:3818. [PMID: 36882486 PMCID: PMC9992459 DOI: 10.1038/s41598-023-30518-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 02/24/2023] [Indexed: 03/09/2023] Open
Abstract
Diabetic retinopathy (DR) is the most common diabetic microvascular complication and cause of blindness in adults under the age of 65. Our results suggest that, when comparing transcriptomes of cultures grown in hypoxic conditions versus room-air, cybrids containing mitochondria from African and Asian diabetic subjects ([Afr + Asi]/DM) have some uniquely different transcriptome profiles compared to European/diabetic (Euro/DM) cybrids (e.g., fatty acid metabolism: EnrichR rank 10 in [Afr + Asi]/DM, rank 85 in Euro/DM; Endocytosis: rank 25 in [Afr + Asi]/DM, rank 5 in Euro/DM; Ubiquitin Mediated Proteolysis: rank 34 in [Afr + Asi]/DM, rank 7 in Euro/DM). As determined by both RNA-seq and qRT-PCR results, transcription of the gene encoding oleoyl-ACP hydrolase (OLAH) was significantly increased in [Afr + Asi]/DM cybrids compared to Euro/DM cybrids in hypoxic conditions. Additionally, our results show that in hypoxic conditions, Euro/DM cybrids and [Afr + Asi]/DM cybrids show similar decreases in ROS production. All cybrids showed decreased ZO1-minus protein levels, but their phagocytic functions were not significantly altered in hypoxic conditions. In conclusion, our findings suggest that the "molecular memory" imparted by [Afr + Asi]/DM mtDNA may act through one of the molecular pathways seen in transcriptome analysis, such as fatty acid metabolism, without significantly changing essential RPE functions.
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187
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Polyunsaturated Lipids in the Light-Exposed and Prooxidant Retinal Environment. Antioxidants (Basel) 2023; 12:antiox12030617. [PMID: 36978865 PMCID: PMC10044808 DOI: 10.3390/antiox12030617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
The retina is an oxidative stress-prone tissue due to high content of polyunsaturated lipids, exposure to visible light stimuli in the 400–480 nm range, and high oxygen availability provided by choroidal capillaries to support oxidative metabolism. Indeed, lipids’ peroxidation and their conversion into reactive species promoting inflammation have been reported and connected to retinal degenerations. Here, we review recent evidence showing how retinal polyunsaturated lipids, in addition to oxidative stress and damage, may counteract the inflammatory response triggered by blue light-activated carotenoid derivatives, enabling long-term retina operation despite its prooxidant environment. These two aspects of retinal polyunsaturated lipids require tight control over their synthesis to avoid overcoming their protective actions by an increase in lipid peroxidation due to oxidative stress. We review emerging evidence on different transcriptional control mechanisms operating in retinal cells to modulate polyunsaturated lipid synthesis over the life span, from the immature to the ageing retina. Finally, we discuss the antioxidant role of food nutrients such as xanthophylls and carotenoids that have been shown to empower retinal cells’ antioxidant responses and counteract the adverse impact of prooxidant stimuli on sight.
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188
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Wang L, Yu X, Zhang D, Wen Y, Zhang L, Xia Y, Chen J, Xie C, Zhu H, Tong J, Shen Y. Long-term blue light exposure impairs mitochondrial dynamics in the retina in light-induced retinal degeneration in vivo and in vitro. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2023; 240:112654. [PMID: 36724628 DOI: 10.1016/j.jphotobiol.2023.112654] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 01/09/2023] [Accepted: 01/21/2023] [Indexed: 01/26/2023]
Abstract
Long-term light exposure, especially in the spectrum of blue light, frequently causes excessive oxidative stress in dry age-related macular degeneration (AMD). Here, to gain insight into the underlying mechanism, we focused on mitochondrial dynamics alterations under long-term exposure to blue light in mouse and retinal cells. Six-month-old C57BL/6 mice were exposed to blue light (450 nm, 800 lx) for 2 weeks. The phenotypic changes in the retina were assayed using haematoxylin-eosin staining and transmission electron microscopy. Long-term blue light exposure significantly thinned each retinal layer in mice, induced retinal apoptosis and impaired retinal mitochondria. A retinal pigment epithelial cell line (ARPE-19) was used to verify the phototoxicity of blue light. Flow cytometry, immunofluorescence and MitoSox Red probe experiments confirmed that more total and mitochondria-specific ROS were generated in the blue light group than in the control group. Mito-Tracker Green probe showed fragmented mitochondrial morphology. The western blotting results indicated a significant increase in DRP1, OMA1, and BAX and a decrease in OPA1 and Bcl-2. In conclusion, long-term exposure to blue light damaged the retinas of mice, especially the ONL and RPE cells. There was destruction and dysfunction of mitochondria in RPE cells in vivo and in vitro. Mitochondrial dynamics were disrupted with characteristics of fusion-related obstruction after blue-light irradiation.
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Affiliation(s)
- Liyin Wang
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Xin Yu
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Dongyan Zhang
- Department of Ophthalmology, Shaoxing Central Hospital, Shaoxing 312030, Zhejiang, China
| | - Yingying Wen
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Liyue Zhang
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Yutong Xia
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Jinbo Chen
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Chen Xie
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Hong Zhu
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China
| | - Jianping Tong
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China.
| | - Ye Shen
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China; Clinical Research Center, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 311003, China.
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Ma JY, Greferath U, Wong JH, Fothergill LJ, Jobling AI, Vessey KA, Fletcher EL. Aging induces cell loss and a decline in phagosome processing in the mouse retinal pigment epithelium. Neurobiol Aging 2023; 128:1-16. [PMID: 37130462 DOI: 10.1016/j.neurobiolaging.2023.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 02/10/2023] [Accepted: 03/03/2023] [Indexed: 03/14/2023]
Abstract
Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss and dysfunction in the retinal pigment epithelium (RPE) with age is known to contribute to disease development. The aim of this study was to investigate how the C57BL/6J mouse RPE changes with age. RPE structure was found to change with age and eccentricity, with cell size increasing, nuclei lost, and tight junctions altered in the peripheral retina. Phagocytosis of photoreceptor outer segments (POS) by the RPE was investigated using gene expression analysis and histology. RNA-Seq transcriptomic gene profiling of the RPE showed a downregulation of genes involved in phagosome processing and histological analysis showed a decline in phagosome-lysosome association in the aged tissue. In addition, failures in the autophagy pathway that modulates intracellular waste degradation were observed in the aged RPE tissue. These findings highlight that RPE cell loss and slowing of POS processing contribute to RPE dysfunction with age and may predispose the aging eye to AMD development.
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190
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Hellinen L, Hongisto H, Ramsay E, Kaarniranta K, Vellonen KS, Skottman H, Ruponen M. Comparison of barrier properties of outer blood-retinal barrier models - Human stem cell-based models as a novel tool for ocular drug discovery. Eur J Pharm Biopharm 2023; 184:181-188. [PMID: 36740104 DOI: 10.1016/j.ejpb.2023.01.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/26/2022] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
The retinal pigment epithelial (RPE) cell monolayer forms the outer blood-retinal barrier and has a crucial role in ocular pharmacokinetics. Although several RPE cell models are available, there have been no systematic comparisons of their barrier properties with respect to drug permeability. We compared the barrier properties of RPE secondary cell lines (ARPE19, and ARPE19mel) and both primary (hfRPE) and stem-cell derived RPE (hESC-RPE) cells by investigating the permeability of nine drugs (aztreonam, ciprofloxacin, dexamethasone, fluconazole, ganciclovir, ketorolac, methotrexate, voriconazole, and quinidine) across cell monolayers. ARPE19, ARPE19mel, and hfRPE cells displayed a narrow Papp value range, with relatively high permeation rates (5.2-26 × 10-6 cm/s). In contrast, hESC-RPE cells efficiently restricted the drug flux, and displayed even lower Papp values than those reported for bovine RPE-choroid, with the range of 0.4-32 cm-6/s. Therefore, ARPE19, ARPE19mel, and hfRPE cells failed to form a tight barrier, whereas hESC-RPE cells restricted the drug flux to a similar extent as bovine RPE-choroid. Therefore, hESC-RPE cells are valuable tools in ocular drug discovery.
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Affiliation(s)
- Laura Hellinen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland.
| | - Heidi Hongisto
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70210 Kuopio, Finland
| | - Eva Ramsay
- Drug Research Programme, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, FI-00014 Helsinki, Finland.
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, 70210 Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, P.O. Box 100, FI-70029 Kuopio, Finland.
| | - Kati-Sisko Vellonen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland.
| | - Heli Skottman
- Faculty of Medicine and Health Technology, BioMediTech, Tampere University, Tampere, Finland.
| | - Marika Ruponen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, 70210 Kuopio, Finland.
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191
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Ma X, Han S, Liu Y, Chen Y, Li P, Liu X, Chang L, Chen YA, Chen F, Hou Q, Hou L. DAPL1 prevents epithelial-mesenchymal transition in the retinal pigment epithelium and experimental proliferative vitreoretinopathy. Cell Death Dis 2023; 14:158. [PMID: 36841807 PMCID: PMC9968328 DOI: 10.1038/s41419-023-05693-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/27/2023]
Abstract
Epithelial-mesenchymal transition (EMT) of the retinal pigment epithelium (RPE) is a hallmark of the pathogenesis of proliferative vitreoretinopathy (PVR) that can lead to severe vision loss. Nevertheless, the precise regulatory mechanisms underlying the pathogenesis of PVR remain largely unknown. Here, we show that the expression of death-associated protein-like 1 (DAPL1) is downregulated in PVR membranes and that DAPL1 deficiency promotes EMT in RPE cells in mice. In fact, adeno-associated virus (AAV)-mediated DAPL1 overexpression in RPE cells of Dapl1-deficient mice inhibited EMT in physiological and retinal-detachment states. In a rabbit model of PVR, ARPE-19 cells overexpressing DAPL1 showed reduced ability to induce experimental PVR, and AAV-mediated DAPL1 delivery attenuated the severity of experimental PVR. Furthermore, a mechanistic study revealed that DAPL1 promotes P21 phosphorylation and its stabilization partially through NFκB (RelA) in RPE cells, whereas the knockdown of P21 led to neutralizing effects on DAPL1-dependent EMT inhibition and enhanced the severity of experimental PVR. These results suggest that DAPL1 acts as a novel suppressor of RPE-EMT and has an important role in antagonizing the pathogenesis of experimental PVR. Hence, this finding has implications for understanding the mechanism of and potential therapeutic applications for PVR.
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Affiliation(s)
- Xiaoyin Ma
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China. .,State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003, China.
| | - Shuxian Han
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China ,grid.412679.f0000 0004 1771 3402Department of Ophthalmology, First Affiliated Hospital of Anhui Medical University, Hefei, 230022 China
| | - Youjia Liu
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China
| | - Yu Chen
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China ,grid.268099.c0000 0001 0348 3990State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003 China
| | - Pingping Li
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China
| | - Xiaoyan Liu
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China
| | - Lifu Chang
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China
| | - Ying-ao Chen
- grid.268099.c0000 0001 0348 3990Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China
| | - Feng Chen
- grid.268099.c0000 0001 0348 3990School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003 China
| | - Qiang Hou
- grid.268099.c0000 0001 0348 3990State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003 China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China. .,State Key Laboratory of Ophthalmology, Optometry and Vision Science, Wenzhou Medical University, Wenzhou, 325003, China.
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192
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Nguyen T, Urrutia-Cabrera D, Wang L, Lees JG, Wang JH, Hung SS, Hewitt AW, Edwards TL, McLenachan S, Chen FK, Lim SY, Luu CD, Guymer R, Wong RC. Knockout of AMD-associated gene POLDIP2 reduces mitochondrial superoxide in human retinal pigment epithelial cells. Aging (Albany NY) 2023; 15:1713-1733. [PMID: 36795578 PMCID: PMC10085620 DOI: 10.18632/aging.204522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023]
Abstract
Genetic and epidemiologic studies have significantly advanced our understanding of the genetic factors contributing to age-related macular degeneration (AMD). In particular, recent expression quantitative trait loci (eQTL) studies have highlighted POLDIP2 as a significant gene that confers risk of developing AMD. However, the role of POLDIP2 in retinal cells such as retinal pigment epithelium (RPE) and how it contributes to AMD pathology are unknown. Here we report the generation of a stable human RPE cell line ARPE-19 with POLDIP2 knockout using CRISPR/Cas, providing an in vitro model to investigate the functions of POLDIP2. We conducted functional studies on the POLDIP2 knockout cell line and showed that it retained normal levels of cell proliferation, cell viability, phagocytosis and autophagy. Also, we performed RNA sequencing to profile the transcriptome of POLDIP2 knockout cells. Our results highlighted significant changes in genes involved in immune response, complement activation, oxidative damage and vascular development. We showed that loss of POLDIP2 caused a reduction in mitochondrial superoxide levels, which is consistent with the upregulation of the mitochondrial superoxide dismutase SOD2. In conclusion, this study demonstrates a novel link between POLDIP2 and SOD2 in ARPE-19, which supports a potential role of POLDIP2 in regulating oxidative stress in AMD pathology.
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Affiliation(s)
- Tu Nguyen
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Daniel Urrutia-Cabrera
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Luozixian Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Jarmon G. Lees
- O’Brien Institute Department, St Vincent’s Institute of Medical Research, Melbourne, Victoria, Australia
- Departments of Surgery and Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Sandy S.C. Hung
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Alex W. Hewitt
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
- Menzies Institute for Medical Research, School of Medicine, University of Tasmania, Hobart, Tasmania, Australia
| | - Thomas L. Edwards
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Sam McLenachan
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Fred K. Chen
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Shiang Y. Lim
- O’Brien Institute Department, St Vincent’s Institute of Medical Research, Melbourne, Victoria, Australia
- Departments of Surgery and Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - Chi D. Luu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Robyn Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Raymond C.B. Wong
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, Australia
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193
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Retinal Pigment Epithelial Abnormality and Choroidal Large Vascular Flow Imbalance Are Associated with Choriocapillaris Flow Deficits in Age-Related Macular Degeneration in Fellow Eyes. J Clin Med 2023; 12:jcm12041360. [PMID: 36835897 PMCID: PMC9965486 DOI: 10.3390/jcm12041360] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Choriocapillaris flow deficits detected on optical coherence tomography angiographs were retrospectively analyzed. In 38 age-related macular degeneration (AMD) fellow eyes, without fundus findings (26 men, 71.7 ± 1.9 years old), and 22 control eyes (11 men, 69.4 ± 1.8), the choriocapillaris flow area (CCFA) ratio and coefficient of variation (CV) of the CCFA ratio (which represented the heterogeneity of the ratio), negatively and positively correlated with age (all p < 0.01), respectively. Moreover, the respective mean values were lower (p = 0.0031) and greater (p = 0.002) in AMD fellow eyes than in the control eyes. The high-risk condition of AMD fellow eyes was defined by a CCFA ratio <58.5%, and the CV of the CCFA ratio ≥0.165 (odds ratio (OR), 5.408; 95% confidence interval (CI): 1.117-21.118, p = 0.035, after adjusting for age and sex) was related to the presence of fundus autofluorescence abnormality (OR, 16.440; 95% CI, 1.262-214.240; p = 0.033) and asymmetrically dilated choroidal large vasculature (OR, 4.176; 95% CI, 1.057-16.503; p = 0.042), after adjusting for age and sex. The presence of fundus autofluorescence abnormality indicated a retinal pigment epithelium (RPE) abnormality. The RPE volume was reduced in the latter eye group, particularly in the thinner choroidal vasculature. In addition to aging, RPE abnormality and choroidal large vascular flow imbalances were associated with exacerbated heterogeneous choriocapillaris flow deficits in AMD fellow eyes without macular neovascularization.
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194
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Augustin S, Lam M, Lavalette S, Verschueren A, Blond F, Forster V, Przegralek L, He Z, Lewandowski D, Bemelmans AP, Picaud S, Sahel JA, Mathis T, Paques M, Thuret G, Guillonneau X, Delarasse C, Sennlaub F. Melanophages give rise to hyperreflective foci in AMD, a disease-progression marker. J Neuroinflammation 2023; 20:28. [PMID: 36755326 PMCID: PMC9906876 DOI: 10.1186/s12974-023-02699-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/13/2023] [Indexed: 02/10/2023] Open
Abstract
Retinal melanosome/melanolipofuscin-containing cells (MCCs), clinically visible as hyperreflective foci (HRF) and a highly predictive imaging biomarker for the progression of age-related macular degeneration (AMD), are widely believed to be migrating retinal pigment epithelial (RPE) cells. Using human donor tissue, we identify the vast majority of MCCs as melanophages, melanosome/melanolipofuscin-laden mononuclear phagocytes (MPs). Using serial block-face scanning electron microscopy, RPE flatmounts, bone marrow transplantation and in vitro experiments, we show how retinal melanophages form by the transfer of melanosomes from the RPE to subretinal MPs when the "don't eat me" signal CD47 is blocked. These melanophages give rise to hyperreflective foci in Cd47-/--mice in vivo, and are associated with RPE dysmorphia similar to intermediate AMD. Finally, we show that Cd47 expression in human RPE declines with age and in AMD, which likely participates in melanophage formation and RPE decline. Boosting CD47 expression in AMD might protect RPE cells and delay AMD progression.
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Affiliation(s)
- Sebastien Augustin
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Marion Lam
- Ophthalmology Department, Université de Paris, APHP, Hôpital Lariboisière, 75010 Paris, France
| | - Sophie Lavalette
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Anna Verschueren
- grid.415610.70000 0001 0657 9752Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, Paris, France
| | - Frédéric Blond
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Valérie Forster
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Lauriane Przegralek
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Zhiguo He
- grid.6279.a0000 0001 2158 1682Laboratory of Biology, Engineering and Imaging for Ophthalmology, BiiO, EA2521, Faculty of Medicine, University of Saint Etienne, Saint Etienne, France
| | - Daniel Lewandowski
- grid.457349.80000 0004 0623 0579Cellules Souches et Radiations, Stabilité Génétique, Université de Paris, Université Paris-Saclay, Inserm, CEA, Fontenay-Aux-Roses, France
| | - Alexis-Pierre Bemelmans
- grid.457349.80000 0004 0623 0579Laboratoire des Maladies Neurodégénératives, Université Paris-Saclay, CEA, CNRS, MIRCen, Fontenay-Aux-Roses, France
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France ,grid.415610.70000 0001 0657 9752Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, Paris, France
| | - Thibaud Mathis
- grid.7849.20000 0001 2150 7757Service d’Ophtalmologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, UMR CNRS 5510 MATEIS, Université Lyon 1, 103 Grande rue de la Croix Rousse, 69317 Lyon Cedex 04, France
| | - Michel Paques
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France ,grid.415610.70000 0001 0657 9752Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, INSERM-DHOS CIC 503, Paris, France
| | - Gilles Thuret
- grid.6279.a0000 0001 2158 1682Laboratory of Biology, Engineering and Imaging for Ophthalmology, BiiO, EA2521, Faculty of Medicine, University of Saint Etienne, Saint Etienne, France
| | - Xavier Guillonneau
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Cécile Delarasse
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012 Paris, France
| | - Florian Sennlaub
- Sorbonne Université, INSERM, CNRS, UMR_S 968, Institut de la Vision, 17 rue Moreau, 75012, Paris, France.
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195
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The Anti-Aging Hormone Klotho Promotes Retinal Pigment Epithelium Cell Viability and Metabolism by Activating the AMPK/PGC-1α Pathway. Antioxidants (Basel) 2023; 12:antiox12020385. [PMID: 36829944 PMCID: PMC9952846 DOI: 10.3390/antiox12020385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/30/2023] [Accepted: 01/30/2023] [Indexed: 02/08/2023] Open
Abstract
Initially discovered by Makuto Kuro-o in 1997, Klotho is a putative aging-suppressor gene when overexpressed and accelerates aging when deleted in mice. Previously, we showed that α-Klotho regulates retinal pigment epithelium (RPE) functions and protects against oxidative stress. However, the mechanisms by which Klotho influences RPE and retinal homeostasis remain elusive. Here, by performing a series of in vitro and in vivo experiments, we demonstrate that Klotho regulates cell viability under oxidative stress, mitochondrial gene expression and activity by inducing the phosphorylation of AMPK and p38MAPK, which in turn phosphorylate and activate CREB and ATF2, respectively, triggering PGC-1α transcription. The inhibition of Klotho in human RPE cells using CRISPR-Cas9 gene editing confirmed that a lack of Klotho negatively affects RPE functions, including mitochondrial activity and cell viability. Proteomic analyses showed that myelin sheath and mitochondrial-related proteins are downregulated in the RPE/retina of Kl-/- compared to WT mice, further supporting our biochemical observations. We conclude that Klotho acts upstream of the AMPK/PGC-1α pathway and regulates RPE/retinal resistance to oxidative stress, mitochondrial function, and gene and protein expressions. Thus, KL decline during aging could negatively impact retinal health, inducing age-related retinal degeneration.
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196
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Fasolino G, Awada G, Moschetta L, Koulalis JS, Neyns B, Verhelst B, Van Elderen P, Nelis P, de Lichtbuer PC, Cools W, Ten Tusscher M. Assessment of Retinal Pigment Epithelium Alterations and Chorioretinal Vascular Network Analyses in Patients under Treatment with BRAF/MEK Inhibitor for Different Malignancies: A Pilot Study. J Clin Med 2023; 12:jcm12031214. [PMID: 36769861 PMCID: PMC9918243 DOI: 10.3390/jcm12031214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/26/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023] Open
Abstract
In the last two decades, an increasing number of so-called molecular-targeted therapies have become available for the treatment of patients with advanced malignancies. These drugs have included inhibitors of proteins in the MAPK pathway, such as BRAF and MEK inhibitors, which are characterized by a distinct toxicity profile. The eye is particularly susceptible to adverse effects due to MEK inhibitors, and the term MEKAR (MEK-inhibitor-associated retinopathy) indicates the presence of subretinal fluid, mimicking central serous chorioretinopathy (CSC). The pathogenesis of the retinal alterations related to MAPK pathway inhibitors is still unclear, and questions are still open. The present study aims to assess the presence of retinal pigment epithelium alterations as predictive parameters for retinal toxicity, analyzing, at the same time, the chorioretinal vascular network in patients undergoing BRAF/MEK inhibitor treatment for different malignancies.
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197
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Ryan AK, Rich W, Reilly MA. Oxidative stress in the brain and retina after traumatic injury. Front Neurosci 2023; 17:1021152. [PMID: 36816125 PMCID: PMC9935939 DOI: 10.3389/fnins.2023.1021152] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/13/2023] [Indexed: 02/05/2023] Open
Abstract
The brain and the retina share many physiological similarities, which allows the retina to serve as a model of CNS disease and disorder. In instances of trauma, the eye can even indicate damage to the brain via abnormalities observed such as irregularities in pupillary reflexes in suspected traumatic brain injury (TBI) patients. Elevation of reactive oxygen species (ROS) has been observed in neurodegenerative disorders and in both traumatic optic neuropathy (TON) and in TBI. In a healthy system, ROS play a pivotal role in cellular communication, but in neurodegenerative diseases and post-trauma instances, ROS elevation can exacerbate neurodegeneration in both the brain and the retina. Increased ROS can overwhelm the inherent antioxidant systems which are regulated via mitochondrial processes. The overabundance of ROS can lead to protein, DNA, and other forms of cellular damage which ultimately result in apoptosis. Even though elevated ROS have been observed to be a major cause in the neurodegeneration observed after TON and TBI, many antioxidants therapeutic strategies fail. In order to understand why these therapeutic approaches fail further research into the direct injury cascades must be conducted. Additional therapeutic approaches such as therapeutics capable of anti-inflammatory properties and suppression of other neurodegenerative processes may be needed for the treatment of TON, TBI, and neurodegenerative diseases.
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Affiliation(s)
- Annie K. Ryan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Wade Rich
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
| | - Matthew A. Reilly
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States,Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, United States,*Correspondence: Matthew A. Reilly,
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198
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Cideciyan AV, Jacobson SG, Sumaroka A, Swider M, Krishnan AK, Sheplock R, Garafalo AV, Guziewicz KE, Aguirre GD, Beltran WA, Matsui Y, Kondo M, Heon E. Photoreceptor function and structure in retinal degenerations caused by biallelic BEST1 mutations. Vision Res 2023; 203:108157. [PMID: 36450205 PMCID: PMC9825664 DOI: 10.1016/j.visres.2022.108157] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 10/17/2022] [Accepted: 11/07/2022] [Indexed: 11/29/2022]
Abstract
The only approved retinal gene therapy is for biallelic RPE65 mutations which cause a recessive retinopathy with a primary molecular defect located at the retinal pigment epithelium (RPE). For a distinct recessive RPE disease caused by biallelic BEST1 mutations, a pre-clinical proof-of-concept for gene therapy has been demonstrated in canine eyes. The current study was undertaken to consider potential outcome measures for a BEST1 clinical trial in patients demonstrating a classic autosomal recessive bestrophinopathy (ARB) phenotype. Spatial distribution of retinal structure showed a wide expanse of abnormalities including large intraretinal cysts, shallow serous retinal detachments, abnormalities of inner and outer segments, and an unusual prominence of the external limiting membrane. Surrounding the central macula extending from 7 to 30 deg eccentricity, outer nuclear layer was thicker than expected from a cone only retina and implied survival of many rod photoreceptors. Co-localized however, were large losses of rod sensitivity despite preserved cone sensitivities. The dissociation of rod function from rod structure observed, supports a large treatment potential in the paramacular region for biallelic bestrophinopathies.
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Affiliation(s)
- Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Arun K Krishnan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rebecca Sheplock
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexandra V Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karina E Guziewicz
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William A Beltran
- Division of Experimental Retinal Therapies, Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yoshitsugu Matsui
- Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON M5G 2L3, Canada
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199
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Iwagawa T, Masumoto H, Tabuchi H, Tani K, Conklin BR, Watanabe S. Evaluation of CRISPR/Cas9 exon-skipping vector for choroideremia using human induced pluripotent stem cell-derived RPE. J Gene Med 2023; 25:e3464. [PMID: 36413603 PMCID: PMC9898118 DOI: 10.1002/jgm.3464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 10/21/2022] [Accepted: 11/13/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Exon-skipping is a powerful genetic tool, especially when delivering genes using an AAV-mediated full-length gene supplementation strategy is difficult owing to large length of genes. Here, we used engineered human induced pluripotent stem cells and artificial intelligence to evaluate clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein 9-based exon-skipping vectors targeting genes of the retinal pigment epithelium (RPE). The model system was choroideremia; this is an X-linked inherited retinal disease caused by mutation of the CHM gene. METHODS We explored whether artificial intelligence detected differentiation of human OTX2, PAX6 and MITF (hOPM) cells, in which OTX2, PAX6 and MITF expression was induced by doxycycline treatment, into RPE. Plasmid encoding CHM exon-skipping modules targeting the splice donor sites of exons 6 were constructed. A clonal hOPM cell line with a frameshift mutation in exon 6 was generated and differentiated into RPE. CHM exon 6-skipping was induced, and the effects of skipping on phagocytic activity, cell death and prenylation of Rab small GTPase (RAB) were evaluated using flow cytometry, an in vitro prenylation assay and western blotting. RESULTS Artificial intelligence-based evaluation of RPE differentiation was successful. Retinal pigment epithelium cells with a frameshift mutation in exon 6 showed increased cell death, reduced phagocytic activity and increased cytosolic unprenylated RABs only when oxidative stress was in play. The latter two phenotypes were partially rescued by exon 6-skipping of CHM. CONCLUSIONS CHM exon 6-skipping contributed to RPE phagocytosis probably by increasing RAB38 prenylation under oxidative stress.
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Affiliation(s)
- Toshiro Iwagawa
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Tokyo, Japan
| | - Hiroki Masumoto
- Xeno Hoc, inc
- Department of Ophthalmology, Tsukazaki Hospital, Hyogo, Japan
| | - Hitoshi Tabuchi
- Department of Ophthalmology, Tsukazaki Hospital, Hyogo, Japan
- Department of Technology and Design Thinking for Medicine, Hiroshima University, Hiroshima, Japan
| | - Kenzaburo Tani
- Laboratory of ALA Advanced Medical Research, Institute for quantitative Biosciences, University of Tokyo, Tokyo, Japan
| | - Bruce R. Conklin
- Gladstone Institutes, San Francisco, CA, USA
- Departments of Medicine, Ophthalmology & Cellular and Molecular Pharmacology University of California, San Francisco, CA, United States, USA
| | - Sumiko Watanabe
- Division of Molecular and Developmental Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Retinal Biology and Pathology, University of Tokyo Hospital, University of Tokyo, Tokyo, Japan
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O'Leary F, Campbell M. The blood-retina barrier in health and disease. FEBS J 2023; 290:878-891. [PMID: 34923749 DOI: 10.1111/febs.16330] [Citation(s) in RCA: 63] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/05/2021] [Accepted: 12/17/2021] [Indexed: 12/20/2022]
Abstract
The blood-retina barrier (BRB) is the term used to define the properties of the retinal capillaries and the retinal pigment epithelium (RPE), which separate the systemic circulation from the retina. More specifically, the inner blood-retina barrier (iBRB) is used to describe the properties of the endothelial cells that line the microvasculature of the inner retina, while the outer blood-retina barrier (oBRB) refers to the properties of the RPE cells that separate the fenestrated choriocapillaris from the retina. The BRB is not a fixed structure; rather, it is dynamic, with its components making unique contributions to its function and structural integrity, and therefore the retina. For example, while tight junction (TJ) proteins between retinal endothelial cells are the key molecular structures in the maintenance of the iBRB, other cell types surrounding endothelial cells are also important. In fact, this overall structure is termed the neurovascular unit (NVU). The integrity of the BRB is crucial in the maintenance of a 'dry', tightly regulated retinal microenvironment through the regulation of transcellular and paracellular transport. Specifically, breakdown of TJs can result in oedema formation, a hallmark feature of many retinal diseases. Here, we will describe the oBRB briefly, with a more in-depth focus on the structure and function of the iBRB in health and diseased states. Finally, the contribution of the BRB to the pathophysiology of age-related macular degeneration (AMD), diabetic retinopathy (DR) and other rarer retinal diseases will be discussed.
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Affiliation(s)
- Fionn O'Leary
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
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