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Cvekl A, Vijg J. Aging of the eye: Lessons from cataracts and age-related macular degeneration. Ageing Res Rev 2024; 99:102407. [PMID: 38977082 DOI: 10.1016/j.arr.2024.102407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/10/2024]
Abstract
Aging is the greatest risk factor for chronic human diseases, including many eye diseases. Geroscience aims to understand the effects of the aging process on these diseases, including the genetic, molecular, and cellular mechanisms that underlie the increased risk of disease over the lifetime. Understanding of the aging eye increases general knowledge of the cellular physiology impacted by aging processes at various biological extremes. Two major diseases, age-related cataract and age-related macular degeneration (AMD) are caused by dysfunction of the lens and retina, respectively. Lens transparency and light refraction are mediated by lens fiber cells lacking nuclei and other organelles, which provides a unique opportunity to study a single aging hallmark, i.e., loss of proteostasis, within an environment of limited metabolism. In AMD, local dysfunction of the photoreceptors/retinal pigmented epithelium/Bruch's membrane/choriocapillaris complex in the macula leads to the loss of photoreceptors and eventually loss of central vision, and is driven by nearly all the hallmarks of aging and shares features with Alzheimer's disease, Parkinson's disease, cardiovascular disease, and diabetes. The aging eye can function as a model for studying basic mechanisms of aging and, vice versa, well-defined hallmarks of aging can be used as tools to understand age-related eye disease.
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Affiliation(s)
- Ales Cvekl
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Jan Vijg
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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2
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Neto MV, De Rossi G, Berkowitz BA, Seabra MC, Luthert PJ, Futter CE, Burgoyne T. Daily Light Onset and Plasma Membrane Tethers Regulate Mitochondria Redistribution within the Retinal Pigment Epithelium. Cells 2024; 13:1100. [PMID: 38994953 PMCID: PMC11240580 DOI: 10.3390/cells13131100] [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: 05/03/2024] [Revised: 06/15/2024] [Accepted: 06/17/2024] [Indexed: 07/13/2024] Open
Abstract
The retinal pigment epithelium (RPE) is an essential component of the retina that plays multiple roles required to support visual function. These include light onset- and circadian rhythm-dependent tasks, such as daily phagocytosis of photoreceptor outer segments. Mitochondria provide energy to the highly specialized and energy-dependent RPE. In this study, we examined the positioning of mitochondria and how this is influenced by the onset of light. We identified a population of mitochondria that are tethered to the basal plasma membrane pre- and post-light onset. Following light onset, mitochondria redistributed apically and interacted with melanosomes and phagosomes. In a choroideremia mouse model that has regions of the RPE with disrupted or lost infolding of the plasma membrane, the positionings of only the non-tethered mitochondria were affected. This provides evidence that the tethering of mitochondria to the plasma membrane plays an important role that is maintained under these disease conditions. Our work shows that there are subpopulations of RPE mitochondria based on their positioning after light onset. It is likely they play distinct roles in the RPE that are needed to fulfil the changing cellular demands throughout the day.
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Affiliation(s)
- Matilde V Neto
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Giulia De Rossi
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Miguel C Seabra
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, 1169-056 Lisboa, Portugal
| | - Philip J Luthert
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Clare E Futter
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Thomas Burgoyne
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
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Ng ESY, Hu J, Jiang Z, Radu RA. Impaired cathepsin D in retinal pigment epithelium cells mediates Stargardt disease pathogenesis. FASEB J 2024; 38:e23720. [PMID: 38837708 PMCID: PMC11296957 DOI: 10.1096/fj.202400210rr] [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: 01/26/2024] [Revised: 05/12/2024] [Accepted: 05/21/2024] [Indexed: 06/07/2024]
Abstract
Recessive Stargardt disease (STGD1) is an inherited juvenile maculopathy caused by mutations in the ABCA4 gene, for which there is no suitable treatment. Loss of functional ABCA4 in the retinal pigment epithelium (RPE) alone, without contribution from photoreceptor cells, was shown to induce STGD1 pathology. Here, we identified cathepsin D (CatD), the primary RPE lysosomal protease, as a key molecular player contributing to endo-lysosomal dysfunction in STGD1 using a newly developed "disease-in-a-dish" RPE model from confirmed STGD1 patients. Induced pluripotent stem cell (iPSC)-derived RPE originating from three STGD1 patients exhibited elevated lysosomal pH, as previously reported in Abca4-/- mice. CatD protein maturation and activity were impaired in RPE from STGD1 patients and Abca4-/- mice. Consequently, STGD1 RPE cells have reduced photoreceptor outer segment degradation and abnormal accumulation of α-synuclein, the natural substrate of CatD. Furthermore, dysfunctional ABCA4 in STGD1 RPE cells results in intracellular accumulation of autofluorescent material and phosphatidylethanolamine (PE). The altered distribution of PE associated with the internal membranes of STGD1 RPE cells presumably compromises LC3-associated phagocytosis, contributing to delayed endo-lysosomal degradation activity. Drug-mediated re-acidification of lysosomes in the RPE of STGD1 restores CatD functional activity and reduces the accumulation of immature CatD protein loads. This preclinical study validates the contribution of CatD deficiencies to STGD1 pathology and provides evidence for an efficacious therapeutic approach targeting RPE cells. Our findings support a cell-autonomous RPE-driven pathology, informing future research aimed at targeting RPE cells to treat ABCA4-mediated retinopathies.
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Affiliation(s)
- Eunice Sze Yin Ng
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Molecular, Cellular, and Integrative Physiology Interdepartmental Program, University of California, Los Angeles, CA 90095, USA
| | - Jane Hu
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Zhichun Jiang
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Roxana A. Radu
- UCLA Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
- Department of Ophthalmology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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4
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Wu S, Li F, Mo K, Huang H, Yu Y, Huang Y, Liu J, Li M, Tan J, Lin Z, Han Z, Wang L, Ouyang H. IGF2BP2 Maintains Retinal Pigment Epithelium Homeostasis by Stabilizing PAX6 and OTX2. Invest Ophthalmol Vis Sci 2024; 65:17. [PMID: 38861275 PMCID: PMC11174093 DOI: 10.1167/iovs.65.6.17] [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: 02/19/2024] [Accepted: 05/15/2024] [Indexed: 06/12/2024] Open
Abstract
Purpose N6-methyladenosine (m6A) methylation is a chemical modification that occurs on RNA molecules, where the hydrogen atom of adenine (A) nucleotides is replaced by a methyl group, forming N6-methyladenosine. This modification is a dynamic and reversible process that plays a crucial role in regulating various biological processes, including RNA stability, transport, translation, and degradation. Currently, there is a lack of research on the role of m6A modifications in maintaining the characteristics of RPE cells. m6A readers play a crucial role in executing the functions of m6A modifications, which prompted our investigation into their regulatory roles in the RPE. Methods Phagocytosis assays, immunofluorescence staining, flow cytometry experiments, β-galactosidase staining, and RNA sequencing (RNA-seq) were conducted to assess the functional and cellular characteristics changes in retinal pigment epithelium (RPE) cells following short-hairpin RNA-mediated knockdown of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2). RNA-seq and ultraviolet crosslinking immunoprecipitation with high-throughput sequencing (HITS-CLIP) were employed to identify the target genes regulated by IGF2BP2. adeno-associated virus (AAV) subretinal injection was performed in 6- to 8-week-old C57 mice to reduce IGF2BP2 expression in the RPE, and the impact of IGF2BP2 knockdown on mouse visual function was assessed using immunofluorescence, quantitative real-time PCR, optical coherence tomography, and electroretinography. Results IGF2BP2 was found to have a pronounced effect on RPE phagocytosis. Subsequent in-depth exploration revealed that IGF2BP2 modulates the mRNA stability of PAX6 and OTX2, and the loss of IGF2BP2 induces inflammatory and aging phenotypes in RPE cells. IGF2BP2 knockdown impaired RPE function, leading to retinal dysfunction in vivo. Conclusions Our data suggest a crucial role of IGF2BP2 as an m6A reader in maintaining RPE homeostasis by regulating the stability of PAX6 and OTX2, making it a potential target for preventing the occurrence of retinal diseases related to RPE malfunction.
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Affiliation(s)
- Siqi Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Fuxi Li
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Kunlun Mo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Huaxing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Yankun Yu
- Department of Pathology, The First Affiliated Hospital of Shihezi University, Shihezi, Xinjiang, China
| | - Ying Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Jiafeng Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Mingsen Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Jieying Tan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Zesong Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Zhuo Han
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Li Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
| | - Hong Ouyang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology Visual Science, Guangzhou, China
- Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
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5
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White ZB, Nair S, Bredel M. The role of annexins in central nervous system development and disease. J Mol Med (Berl) 2024; 102:751-760. [PMID: 38639785 PMCID: PMC11106189 DOI: 10.1007/s00109-024-02443-7] [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: 03/27/2023] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/20/2024]
Abstract
Annexins, a group of Ca2+-dependent phospholipid-binding proteins, exert diverse roles in neuronal development, normal central nervous system (CNS) functioning, neurological disorders, and CNS tumors. This paper reviews the roles of individual annexins (A1-A13) in these contexts. Annexins possess unique structural and functional features, such as Ca2+-dependent binding to phospholipids, participating in membrane organization, and modulating cell signaling. They are implicated in various CNS processes, including endocytosis, exocytosis, and stabilization of plasma membranes. Annexins exhibit dynamic roles in neuronal development, influencing differentiation, proliferation, and synaptic formation in CNS tissues. Notably, annexins such as ANXA1 and ANXA2 play roles in apoptosis and blood-brain barrier (BBB) integrity. Neurological disorders, including Alzheimer's disease, multiple sclerosis, and depression, involve annexin dysregulation, influencing neuroinflammation, blood-brain barrier integrity, and stress responses. Moreover, annexins contribute to the pathogenesis of CNS tumors, either promoting or suppressing tumor growth, angiogenesis, and invasion. Annexin expression patterns vary across different CNS tumor types, providing potential prognostic markers and therapeutic targets. This review underscores the multifaceted roles of annexins in the CNS, highlighting their importance in normal functioning, disease progression, and potential therapeutic interventions.
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Affiliation(s)
- Zachary B White
- Department of Radiation Oncology, O'Neal Comprehensive Cancer Center, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sindhu Nair
- Department of Radiation Oncology, O'Neal Comprehensive Cancer Center, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Markus Bredel
- Department of Radiation Oncology, O'Neal Comprehensive Cancer Center, Heersink School of Medicine, The University of Alabama at Birmingham, Birmingham, AL, USA.
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Dubey SK, Dubey R, Prajapati SC, Jung K, Mohan K, Liu X, Roney J, Tian W, Abney J, Giarmarco MM, Hernandez AG, Liu J, Kleinman ME. Histone deficiency and hypoacetylation in the aging retinal pigment epithelium. Aging Cell 2024; 23:e14108. [PMID: 38408164 PMCID: PMC11113634 DOI: 10.1111/acel.14108] [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: 11/08/2023] [Revised: 01/24/2024] [Accepted: 01/30/2024] [Indexed: 02/28/2024] Open
Abstract
Histones serve as a major carrier of epigenetic information in the form of post-translational modifications which are vital for controlling gene expression, maintaining cell identity, and ensuring proper cellular function. Loss of histones in the aging genome can drastically impact the epigenetic landscape of the cell leading to altered chromatin structure and changes in gene expression profiles. In this study, we investigated the impact of age-related changes on histone levels and histone acetylation in the retinal pigment epithelium (RPE) and retina of mice. We observed a global reduction of histones H1, H2A, H2B, H3, and H4 in aged RPE/choroid but not in the neural retina. Transcriptomic analyses revealed significant downregulation of histones in aged RPE/choroid including crucial elements of the histone locus body (HLB) complex involved in histone pre-mRNA processing. Knockdown of HINFP, a key HLB component, in human RPE cells induced histone loss, senescence, and the upregulation of senescence-associated secretory phenotype (SASP) markers. Replicative senescence and chronological aging in human RPE cells similarly resulted in progressive histone loss and acquisition of the SASP. Immunostaining of human retina sections revealed histone loss in RPE with age. Acetyl-histone profiling in aged mouse RPE/choroid revealed a specific molecular signature with loss of global acetyl-histone levels, including H3K14ac, H3K56ac, and H4K16ac marks. These findings strongly demonstrate histone loss as a unique feature of RPE aging and provide critical insights into the potential mechanisms linking histone dynamics, cellular senescence, and aging.
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Affiliation(s)
- Sushil K. Dubey
- Department of SurgeryEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Rashmi Dubey
- Department of SurgeryEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Subhash C. Prajapati
- Department of Biochemistry and Molecular GeneticsUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Kyungsik Jung
- Department of SurgeryEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Kabhilan Mohan
- Department of SurgeryEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Xinan Liu
- Department of Computer ScienceUniversity of KentuckyLexingtonKentuckyUSA
| | - Jacob Roney
- Department of Ophthalmology and Visual SciencesUniversity of KentuckyLexingtonKentuckyUSA
| | - Wenjian Tian
- Department of SurgeryEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Jennifer Abney
- Department of Ophthalmology and Visual SciencesUniversity of KentuckyLexingtonKentuckyUSA
| | | | - Alvaro G. Hernandez
- Roy J. Carver Biotechnology CenterUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
| | - Jinze Liu
- Department of BiostatisticsVirginia Commonwealth UniversityRichmondVirginiaUSA
| | - Mark E. Kleinman
- Department of SurgeryEast Tennessee State UniversityJohnson CityTennesseeUSA
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7
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Gurubaran IS. Mitochondrial damage and clearance in retinal pigment epithelial cells. Acta Ophthalmol 2024; 102 Suppl 282:3-53. [PMID: 38467968 DOI: 10.1111/aos.16661] [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: 01/24/2024] [Accepted: 01/31/2024] [Indexed: 03/13/2024]
Abstract
Age-related macular degeneration (AMD) is a devastating eye disease that causes permanent vision loss in the central part of the retina, known as the macula. Patients with such severe visual loss face a reduced quality of life and are at a 1.5 times greater risk of death compared to the general population. Currently, there is no cure for or effective treatment for dry AMD. There are several mechanisms thought to underlie the disease, for example, ageing-associated chronic oxidative stress, mitochondrial damage, harmful protein aggregation and inflammation. As a way of gaining a better understanding of the molecular mechanisms behind AMD and thus developing new therapies, we have created a peroxisome proliferator-activated receptor gamma coactivator 1-alpha and nuclear factor erythroid 2-related factor 2 (PGC1α/NFE2L2) double-knockout (dKO) mouse model that mimics many of the clinical features of dry AMD, including elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in retinal pigment epithelial cells (RPE). In addition, a human RPE cell-based model was established to examine the impact of non-functional intracellular clearance systems on inflammasome activation. In this study, we found that there was a disturbance in the autolysosomal machinery responsible for clearing mitochondria in the RPE cells of one-year-old PGC1α/NFE2L2-deficient mice. The confocal immunohistochemical analysis revealed an increase in autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as multiple mitophagy markers such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN), along with signs of damaged mitochondria. However, no increase in autolysosome formation was detected, nor was there a colocalization of the lysosomal marker LAMP2 or the mitochondrial marker, ATP synthase β. There was an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells, together with autofluorescent aggregates. Additionally, we observed an increase in the numbers of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in PGC1α/NFE2L2 dKO retinal specimens compared to wild-type animals. There was a trend towards increased complement component C5a and increased involvement of the serine protease enzyme, thrombin, in enhancing the terminal pathway producing C5a, independent of C3. The levels of primary acute phase C-reactive protein and receptor for advanced glycation end products were also increased in the PGC1α/NFE2L2 dKO retina. Furthermore, selective proteasome inhibition with epoxomicin promoted both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondrial-mediated oxidative stress, leading to the release of mitochondrial DNA to the cytosol, resulting in potassium efflux-dependent activation of the absent in melanoma 2 (AIM2) inflammasome and the subsequent secretion of interleukin-1β in ARPE-19 cells. In conclusion, the data suggest that there is at least a relative decrease in mitophagy, increases in the amounts of C5 and thrombin and decreased C3 levels in this dry AMD-like model. Moreover, selective proteasome inhibition evoked mitochondrial damage and AIM2 inflammasome activation in ARPE-19 cells.
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Affiliation(s)
- Iswariyaraja Sridevi Gurubaran
- Department of Medicine, Clinical Medicine Unit, University of Eastern Finland Institute of Clinical Medicine, Kuopio, Northern Savonia, Finland
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Pan F, Shu Q, Xie H, Zhao L, Wu P, Du Y, Lu J, He Y, Wang X, Peng H. Protective effects of triptolide against oxidative stress in retinal pigment epithelium cells via the PI3K/AKT/Nrf2 pathway: a network pharmacological method and experimental validation. Aging (Albany NY) 2024; 16:3955-3972. [PMID: 38393691 PMCID: PMC10929812 DOI: 10.18632/aging.205570] [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: 09/08/2023] [Accepted: 01/11/2024] [Indexed: 02/25/2024]
Abstract
PURPOSE Among aging adults, age-related macular degeneration (AMD), is a prevalent cause of blindness. Nevertheless, its progression may be halted by antioxidation in retinal pigment epithelium (RPE). The primary effective constituent of Tripterygium wilfordii Hook. F., triptolide (TP), has demonstrated anti-inflammatory, antiproliferative, and antioxidant properties. The mechanics of the protective effect of triptolide against the oxidative damage in retinal pigment epithelial (RPE) were assessed in this study. METHODS ARPE-19 cells were pretreated with TP, and then exposed to sodium iodate (SI). First, cell viability was assessed using CCK-8. Subsequently, we measured indicators for cell oxidation including reactive oxygen species (ROS), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA). Then, we used network pharmacological analysis and molecular docking to explore the signaling pathway of TP. Last, we used western blot, ELISA, and immunofluorescence assays to clarify the potential mechanistic pathways. RESULTS The network pharmacology data suggested that TP may inhibit AMD by regulating the PI3K/Akt signaling pathway. Experimental results showed that the potential mechanism is that it regulates the PI3K/Akt pathway and promotes Nrf2 phosphorylation and activation, thereby raising the level of antioxidant factors (HO-1, NQO1) and reducing the generation of ROS, which inhibit oxidative damage. CONCLUSION Our findings suggested that the effect of TP on SI-exposed RPE cells principally relies on the regulation of oxidative stress through the PI3K/Akt/Nrf2 signaling pathway.
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Affiliation(s)
- Fuying Pan
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Qinxin Shu
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Hao Xie
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Long Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Ping Wu
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Yong Du
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Jing Lu
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Yuxia He
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Xing Wang
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
| | - Hui Peng
- Department of Ophthalmology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
- Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing 400016, China
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9
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Lindell M, Kar D, Sedova A, Kim YJ, Packer OS, Schmidt-Erfurth U, Sloan KR, Marsh M, Dacey DM, Curcio CA, Pollreisz A. Volumetric Reconstruction of a Human Retinal Pigment Epithelial Cell Reveals Specialized Membranes and Polarized Distribution of Organelles. Invest Ophthalmol Vis Sci 2023; 64:35. [PMID: 38133501 PMCID: PMC10746928 DOI: 10.1167/iovs.64.15.35] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/04/2023] [Indexed: 12/23/2023] Open
Abstract
Purpose Despite the centrality of the retinal pigment epithelium (RPE) in vision and retinopathy our picture of RPE morphology is incomplete. With a volumetric reconstruction of human RPE ultrastructure, we aim to characterize major membranous features including apical processes and their interactions with photoreceptor outer segments, basolateral infoldings, and the distribution of intracellular organelles. Methods A parafoveal retinal sample was acquired from a 21-year-old male organ donor. With serial block-face scanning electron microscopy, a tissue volume from the inner-outer segment junction to basal RPE was captured. Surface membranes and complete internal ultrastructure of an individual RPE cell were achieved with a combination of manual and automated segmentation methods. Results In one RPE cell, apical processes constitute 69% of the total cell surface area, through a dense network of over 3000 terminal branches. Single processes contact several photoreceptors. Basolateral infoldings facing the choriocapillaris resemble elongated filopodia and comprise 22% of the cell surface area. Membranous tubules and sacs of endoplasmic reticulum represent 20% of the cell body volume. A dense basal layer of mitochondria extends apically to partly overlap electron-dense pigment granules. Pores in the nuclear envelope form a distinct pattern of rows aligned with chromatin. Conclusions Specialized membranes at the apical and basal side of the RPE cell body involved in intercellular uptake and transport represent over 90% of the total surface area. Together with the polarized distribution of organelles within the cell body, these findings are relevant for retinal clinical imaging, therapeutic approaches, and disease pathomechanisms.
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Affiliation(s)
- Maximilian Lindell
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Deepayan Kar
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Aleksandra Sedova
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Yeon Jin Kim
- Department of Biological Structure, University of Washington, Seattle, Washington, United States
| | - Orin S. Packer
- Department of Biological Structure, University of Washington, Seattle, Washington, United States
| | | | - Kenneth R. Sloan
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Mike Marsh
- Object Research Systems, Montreal, Quebec, Canada
| | - Dennis M. Dacey
- Department of Biological Structure, University of Washington, Seattle, Washington, United States
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Andreas Pollreisz
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
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10
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Supe S, Dighe V, Upadhya A, Singh K. Analysis of RNA Interference Targeted Against Human Antigen R (HuR) to Reduce Vascular Endothelial Growth Factor (VEGF) Protein Expression in Human Retinal Pigment Epithelial Cells. Mol Biotechnol 2023:10.1007/s12033-023-00913-w. [PMID: 37856012 DOI: 10.1007/s12033-023-00913-w] [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: 04/07/2023] [Accepted: 09/18/2023] [Indexed: 10/20/2023]
Abstract
VEGF-A or vascular endothelial growth factor-A is an important factor in enabling neovascularization and angiogenesis. VEGF-A is regulated transcriptionally as well as post transcriptionally. Human antigen R (HuR) belonging to the embryonic lethal abnormal vision (ELAV) family is a key regulator promoting stabilization of VEGF-A mRNA. In this research we investigate, whether HuR targeted RNA interference would enable the reduction of the VEGF-A protein in human retinal pigment epithelial cells (ARPE-19) in-vitro, in normoxic conditions. Three siRNA molecules with sequences complementary to three regions of the HuR mRNA were designed. The three designed siRNA molecules were individually transfected in ARPE-19 cells using Lipofectamine™2000 reagent. Post-transfection (24 h, 48 h, 72 h), downregulation of HuR mRNA was estimated by real-time polymerase reaction, while HuR protein and VEGF-A protein levels were semi-quantitatively determined by western blotting techniques. VEGF-A protein levels were additionally quantified using ELISA techniques. All experiments were done in triplicate. The designed siRNA could successfully downregulate HuR mRNA with concomitant decreases in HuR and VEGF-A protein. The study reveals that HuR downregulation can prominently downregulate VEGF-A, making the protein a target for therapy against pathological angiogenesis conditions such as diabetic retinopathy.
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Affiliation(s)
- Shibani Supe
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM'S NMIMS, Vile Parle (W), Mumbai, Maharashtra, 400056, India
| | - Vikas Dighe
- National Centre for Preclinical Reproductive and Genetic Toxicology, ICMR-National Institute for Research in Reproductive and Child Health, J.M. Street, Parel, Mumbai, Maharashtra, 400012, India
| | - Archana Upadhya
- Maharashtra Educational Society's H. K. College of Pharmacy, H. K. College Campus, Oshiwara, Jogeshwari (W), Mumbai, Maharashtra, 400102, India.
| | - Kavita Singh
- Shobhaben Pratapbhai Patel School of Pharmacy and Technology Management, SVKM'S NMIMS, Vile Parle (W), Mumbai, Maharashtra, 400056, India.
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11
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Lieffrig SA, Gyimesi G, Mao Y, Finnemann SC. Clearance phagocytosis by the retinal pigment epithelial during photoreceptor outer segment renewal: Molecular mechanisms and relation to retinal inflammation. Immunol Rev 2023; 319:81-99. [PMID: 37555340 PMCID: PMC10615845 DOI: 10.1111/imr.13264] [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: 05/15/2023] [Accepted: 07/18/2023] [Indexed: 08/10/2023]
Abstract
Mammalian photoreceptor outer segment renewal is a highly coordinated process that hinges on timed cell signaling between photoreceptor neurons and the adjacent retinal pigment epithelial (RPE). It is a strictly rhythmic, synchronized process that underlies in part circadian regulation. We highlight findings from recently developed methods that quantify distinct phases of outer segment renewal in retinal tissue. At light onset, outer segments expose the conserved "eat-me" signal phosphatidylserine exclusively at their distal, most aged tip. A coordinated two-receptor efferocytosis process follows, in which ligands bridge outer segment phosphatidylserine with the RPE receptors αvβ5 integrin, inducing cytosolic signaling toward Rac1 and focal adhesion kinase/MERTK, and with MERTK directly, additionally inhibiting RhoA/ROCK and thus enabling F-actin dynamics favoring outer segment fragment engulfment. Photoreceptors and RPE persist for life with each RPE cell in the eye servicing dozens of overlying photoreceptors. Thus, RPE cells phagocytose more often and process more material than any other cell type. Mutant mice with impaired outer segment renewal largely retain functional photoreceptors and retinal integrity. However, when anti-inflammatory signaling in the RPE via MERTK or the related TYRO3 is lacking, catastrophic inflammation leads to immune cell infiltration that swiftly destroys the retina causing blindness.
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Affiliation(s)
- Stephanie A. Lieffrig
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
| | - Gavin Gyimesi
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
| | | | - Silvia C. Finnemann
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY
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12
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Burstyn-Cohen T, Fresia R. TAM receptors in phagocytosis: Beyond the mere internalization of particles. Immunol Rev 2023; 319:7-26. [PMID: 37596991 DOI: 10.1111/imr.13267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/18/2023] [Indexed: 08/21/2023]
Abstract
TYRO3, AXL, and MERTK constitute the TAM family of receptor tyrosine kinases, activated by their ligands GAS6 and PROS1. TAMs are necessary for adult homeostasis in the immune, nervous, reproductive, skeletal, and vascular systems. Among additional cellular functions employed by TAMs, phagocytosis is central for tissue health. TAM receptors are dominant in providing phagocytes with the molecular machinery necessary to engulf diverse targets, including apoptotic cells, myelin debris, and portions of live cells in a phosphatidylserine-dependent manner. Simultaneously, TAMs drive the release of anti-inflammatory and tissue repair molecules. Disruption of the TAM-driven phagocytic pathway has detrimental consequences, resulting in autoimmunity, male infertility, blindness, and disrupted vascular integrity, and which is thought to contribute to neurodegenerative diseases. Although structurally and functionally redundant, the TAM receptors and ligands underlie complex signaling cascades, of which several key aspects are yet to be elucidated. We discuss similarities and differences between TAMs and other phagocytic pathways, highlight future directions and how TAMs can be harnessed therapeutically to modulate phagocytosis.
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Affiliation(s)
- Tal Burstyn-Cohen
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Roberta Fresia
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
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13
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Chen X, Shi C, He M, Xiong S, Xia X. Endoplasmic reticulum stress: molecular mechanism and therapeutic targets. Signal Transduct Target Ther 2023; 8:352. [PMID: 37709773 PMCID: PMC10502142 DOI: 10.1038/s41392-023-01570-w] [Citation(s) in RCA: 45] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 06/17/2023] [Accepted: 07/14/2023] [Indexed: 09/16/2023] Open
Abstract
The endoplasmic reticulum (ER) functions as a quality-control organelle for protein homeostasis, or "proteostasis". The protein quality control systems involve ER-associated degradation, protein chaperons, and autophagy. ER stress is activated when proteostasis is broken with an accumulation of misfolded and unfolded proteins in the ER. ER stress activates an adaptive unfolded protein response to restore proteostasis by initiating protein kinase R-like ER kinase, activating transcription factor 6, and inositol requiring enzyme 1. ER stress is multifaceted, and acts on aspects at the epigenetic level, including transcription and protein processing. Accumulated data indicates its key role in protein homeostasis and other diverse functions involved in various ocular diseases, such as glaucoma, diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, achromatopsia, cataracts, ocular tumors, ocular surface diseases, and myopia. This review summarizes the molecular mechanisms underlying the aforementioned ocular diseases from an ER stress perspective. Drugs (chemicals, neurotrophic factors, and nanoparticles), gene therapy, and stem cell therapy are used to treat ocular diseases by alleviating ER stress. We delineate the advancement of therapy targeting ER stress to provide new treatment strategies for ocular diseases.
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Affiliation(s)
- Xingyi Chen
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Chaoran Shi
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Meihui He
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China
| | - Siqi Xiong
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
| | - Xiaobo Xia
- Eye Center of Xiangya Hospital, Central South University, 410008, Changsha, Hunan, China.
- Hunan Key Laboratory of Ophthalmology, Central South University, 410008, Changsha, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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14
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Koller A, Brunner SM, Preishuber-Pflügl J, Mayr D, Ladek AM, Runge C, Reitsamer HA, Trost A. Inhibition of CysLTR1 reduces the levels of aggregated proteins in retinal pigment epithelial cells. Sci Rep 2023; 13:13239. [PMID: 37580467 PMCID: PMC10425468 DOI: 10.1038/s41598-023-40248-9] [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: 05/18/2023] [Accepted: 08/07/2023] [Indexed: 08/16/2023] Open
Abstract
The endosomal-lysosomal system (ELS), which carries out cellular processes such as cellular waste degradation via autophagy, is essential for cell homeostasis. ELS inefficiency leads to augmented levels of damaged organelles and intracellular deposits. Consequently, the modulation of autophagic flux has been recognized as target to remove damaging cell waste. Recently, we showed that cysteinyl leukotriene receptor 1 (CysLTR1) antagonist application increases the autophagic flux in the retinal pigment epithelial cell line ARPE-19. Consequently, we investigated the effect of CysLTR1 inhibition-driven autophagy induction on aggregated proteins in ARPE-19 cells using flow cytometry analysis. A subset of ARPE-19 cells expressed CysLTR1 on the surface (SE+); these cells showed increased levels of autophagosomes, late endosomes/lysosomes, aggregated proteins, and autophagy as well as decreased reactive oxygen species (ROS) formation. Furthermore, CysLTR1 inhibition for 24 h using the antagonist zafirlukast decreased the quantities of autophagosomes, late endosomes/lysosomes, aggregated proteins and ROS in CysLTR1 SE- and SE+ cells. We concluded that high levels of plasma membrane-localized CysLTR1 indicate an increased amount of aggregated protein, which raises the rate of autophagic flux. Furthermore, CysLTR1 antagonist application potentially mimics the physiological conditions observed in CysLTR1 SE+ cells and can be considered as strategy to dampen cellular aging.
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Affiliation(s)
- Andreas Koller
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.
| | - Susanne Maria Brunner
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Julia Preishuber-Pflügl
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Daniela Mayr
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Anja-Maria Ladek
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Christian Runge
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Herbert Anton Reitsamer
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
| | - Andrea Trost
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria
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15
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Piri N, Kaplan HJ. Role of Complement in the Onset of Age-Related Macular Degeneration. Biomolecules 2023; 13:biom13050832. [PMID: 37238702 DOI: 10.3390/biom13050832] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive degenerative disease of the central retina and the leading cause of severe loss of central vision in people over age 50. Patients gradually lose central visual acuity, compromising their ability to read, write, drive, and recognize faces, all of which greatly impact daily life activities. Quality of life is significantly affected in these patients, and there are worse levels of depression as a result. AMD is a complex, multifactorial disease in which age and genetics, as well as environmental factors, all play a role in its development and progression. The mechanism by which these risk factors interact and converge towards AMD are not fully understood, and therefore, drug discovery is challenging, with no successful therapeutic attempt to prevent the development of this disease. In this review, we describe the pathophysiology of AMD and review the role of complement, which is a major risk factor in the development of AMD.
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Affiliation(s)
- Niloofar Piri
- Department of Ophthalmology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
| | - Henry J Kaplan
- Departments of Ophthalmology and Biochemistry & Molecular Biology, School of Medicine, Saint Louis University, St. Louis, MO 63104, USA
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16
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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: 4] [Impact Index Per Article: 4.0] [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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17
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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: 6] [Impact Index Per Article: 6.0] [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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18
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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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19
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P2X7 Is Involved in the Mouse Retinal Degeneration via the Coordinated Actions in Different Retinal Cell Types. Antioxidants (Basel) 2023; 12:antiox12010141. [PMID: 36671003 PMCID: PMC9854982 DOI: 10.3390/antiox12010141] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 01/02/2023] [Accepted: 01/03/2023] [Indexed: 01/11/2023] Open
Abstract
Adenosine triphosphate (ATP) released from dying cells with high concentrations is sensed as a danger signal by the P2X7 receptor. Sodium iodate (NaIO3) is an oxidative toxic agent, and its retinal toxicity has been used as the model of dry age-related macular degeneration (AMD). In this study, we used NaIO3-treated mice and cultured retinal cells, including BV-2 microglia, 661W photoreceptors, rMC1 Müller cells and ARPE-19 retinal epithelial cells, to understand the pathological action of P2X7 in retinal degeneration. We found that NaIO3 can significantly decrease the photoreceptor function by reducing a-wave and b-wave amplitudes in electroretinogram (ERG) analysis. Optical coherence tomography (OCT) analysis revealed the degeneration of retinal epithelium and ganglion cell layers. Interestingly, P2X7-/- mice were protected from the NaIO3-induced retinopathy and inflammatory NLRP3, IL-1β and IL-6 gene expression in the retina. Hematoxylin and eosin staining indicated that the retinal epithelium was less deteriorated in P2X7-/- mice compared to the WT group. Although P2X7 was barely detected in 661W, rMC1 and ARPE-19 cells, its gene and protein levels can be increased after NaIO3 treatment, leading to a synergistic cytotoxicity of BzATP [2'(3')-O-(4-benzoylbenzoyl)adenosine-5'-triphosphate tri(triethyleneammonium)salt] and NaIO3 administration in ARPE-19 cells. In conclusion, the paracrine action of the ATP/P2X7 axis via cell-cell communication is involved in NaIO3-induced retinal injury. Our results show that P2X7 antagonist might be a potential therapy in inflammation-related retinal degeneration.
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20
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Ozturk BE. Understanding Ischemic Retinopathies: The Role of Succinate and Its Receptor in Retinal Pigment Epithelium. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:527-531. [PMID: 37440082 DOI: 10.1007/978-3-031-27681-1_77] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Retinopathy is the general name for all condition of the eyes in which blood vessels that supply oxygen to the retina are damaged. These include diabetic retinopathy, retinopathy of prematurity, hypertensive retinopathy, and arteriosclerotic retinopathy. Although the initial trigger that leads to insufficient perfusion of the retina may be different, once a critical level of ischemia is achieved, all types of retinopathies seem to follow a common sequence-oxidative stress, followed by hypoxia-induced formation of morphologically abnormal vessels. This preretinal vascular growth is the most severe aspect of the retinopathy, as the outcome is often retinal detachment and eventually blindness. Regardless of which therapy strategy is followed, a deeper understanding of both normal retinal growth and the underlying molecular mechanisms of retinopathies is needed in order to come up with more effective therapies. This chapter focuses on the citric acid cycle intermediate succinate and its G protein-coupled receptor SUCNR1 in ischemic retinopathies, which were identified as potent mediators of vessel growth in the settings of both normal retinal development and proliferative ischemic retinopathies.
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Affiliation(s)
- Bilge Esin Ozturk
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, USA.
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21
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Serjanov D, Hyde DR. Extracellular Matrix: The Unexplored Aspects of Retinal Pathologies and Regeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:309-317. [PMID: 37440050 DOI: 10.1007/978-3-031-27681-1_45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Nearly a billion people worldwide are affected by vision-impairing conditions, with retinal degenerative diseases being a major cause of blindness. Unfortunately, such diseases are often permanent and progressive, resulting in further degeneration and loss of sight, due to the human retina possessing little, if any, regenerative capacity. Despite numerous efforts and great progress being made to understand the molecular mechanisms of these diseases and possible therapies, the majority of investigations focused on cell-intrinsic factors. However, the microenvironment surrounding retinal cells throughout these processes also plays an important role, though our current understanding of its involvement remains limited. Here we present a brief overview of the current state of the field of extracellular matrix studies within the retina and its potential roles in retinal diseases and potential therapeutic approaches.
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Affiliation(s)
- Dmitri Serjanov
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - David R Hyde
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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22
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Saxena S, Singh M, Chaubey A, Mohan A, De S, Kaur A, Gilhotra JS, Meyer CH, Akduman L. Anti-Vegf therapy leads to an improvement in grade of retinal pigment epithelium alterations on single layer retinal pigment epithelium map in diabetic macular edema. Eur J Ophthalmol 2022; 33:1412-1417. [PMID: 36575598 DOI: 10.1177/11206721221146581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE In bovine retinal pigment epithelium (RPE) cells, increased secretion of vascular endothelial growth factor (VEGF) has a positive linear association with proliferation of RPE. Spectral domain optical coherence tomography (SD-OCT) based improvement in grades of topographic retinal pigment epithelium alterations (RPE-A), were evaluated after intravitreal anti-VEGF therapy, in diabetic macular edema (DME), for the first time. METHODS A tertiary care center-based, prospective study. Forty-four consecutive patients, 40-65 years of age with type 2 diabetes mellitus (DM) with DME, were administered three doses of anti-VEGF therapy at monthly intervals. Pre- and post-intervention SD-OCT was done and central sub field thickness (CST), cube average thickness (CAT) and topographic grades of RPE-A were assessed using single layer RPE map (SL-RPE) as; Grade 0: No alterations, Grade 1: Alteration in two quadrants, Grade 2: Alteration in more than two quadrants. RESULTS CST decreased from 354.2 ± 16.0 µm pre-intervention to 233.2 ± 7.9 µm post-intervention. CAT reduced from 340.6 ± 6.5 µm pre-intervention to 274.1 ± 5.1 µm post-intervention. Significant improvement in grades of RPE-A pre- v/s post-intervention were observed. (Grade 0: 0 v/s 39; Grade 1: 17 v/s 3; Grade 2: 27 v/s 2) (p < 0.001). CONCLUSION Anti-VEGF therapy is associated with an improvement in grades of RPE-A in DME.The study was registered with the Clinical Trial Registry of India (CTRI/2019/03/018135).
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Affiliation(s)
- Sandeep Saxena
- Department of Ophthalmology, 76140King George's Medical University, Lucknow, India
| | - Malvika Singh
- Department of Ophthalmology, 76140King George's Medical University, Lucknow, India
| | - Anupriya Chaubey
- Department of Ophthalmology, 76140King George's Medical University, Lucknow, India
| | - Akshay Mohan
- Department of Ophthalmology, 76140King George's Medical University, Lucknow, India
| | - Somnath De
- Department of Ophthalmology, 76140King George's Medical University, Lucknow, India
| | - Apjit Kaur
- Department of Ophthalmology, 76140King George's Medical University, Lucknow, India
| | | | | | - Levent Akduman
- Vitreoretinal and Uveitis Service, Department of Ophthalmology, 12274St. Louis University School of Medicine, St. Louis, MO, USA
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23
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Gelat B, Rathaur P, Malaviya P, Patel B, Trivedi K, Johar K, Gelat R. The intervention of epithelial-mesenchymal transition in homeostasis of human retinal pigment epithelial cells: a review. J Histotechnol 2022; 45:148-160. [DOI: 10.1080/01478885.2022.2137665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Brijesh Gelat
- Department of Zoology, BMTC and Human Genetics, School of Sciences, Gujarat University, Ahmedabad, India
| | - Pooja Rathaur
- Department of Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, Gujarat, India
| | - Pooja Malaviya
- Department of Cell and Molecular Biology, Iladevi Cataract and IOL Research Centre, Ahmedabad, Gujarat, India
| | - Binita Patel
- Department of Life Science, School of Sciences, Gujarat University, Ahmedabad, India
| | - Krupali Trivedi
- Department of Zoology, BMTC and Human Genetics, School of Sciences, Gujarat University, Ahmedabad, India
| | - Kaid Johar
- Department of Zoology, BMTC and Human Genetics, School of Sciences, Gujarat University, Ahmedabad, India
| | - Rahul Gelat
- Institute of Teaching and Research in Ayurveda (ITRA), Gujarat Ayurved University, Jamnagar, India
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24
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Muni RH, Lee WW, Bansal A, Ramachandran A, Hillier RJ. A paradigm shift in retinal detachment repair: The concept of integrity. Prog Retin Eye Res 2022; 91:101079. [DOI: 10.1016/j.preteyeres.2022.101079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/15/2022] [Accepted: 05/17/2022] [Indexed: 11/09/2022]
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25
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Chen X, Wang Y, Wang JN, Cao QC, Sun RX, Zhu HJ, Zhang YR, Ji JD, Liu QH. m6A modification of circSPECC1 suppresses RPE oxidative damage and maintains retinal homeostasis. Cell Rep 2022; 41:111671. [DOI: 10.1016/j.celrep.2022.111671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 07/11/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
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26
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Segurado A, Rodríguez-Carrillo A, Castellanos B, Hernández-Galilea E, Velasco A, Lillo C. Scribble basal polarity acquisition in RPE cells and its mislocalization in a pathological AMD-like model. Front Neuroanat 2022; 16:983151. [PMID: 36213611 PMCID: PMC9539273 DOI: 10.3389/fnana.2022.983151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/25/2022] [Indexed: 11/13/2022] Open
Abstract
Apicobasal polarity is a hallmark of retinal pigment epithelium cells and is required to perform their functions; however, the precise roles of the different proteins that execute polarity are still poorly understood. Here, we have studied the expression and location of Scribble, the core member of the polarity basal protein complex in epithelial-derived cells, in human and mouse RPE cells in both control and pathological conditions. We found that Scribble specifically localizes at the basolateral membrane of mouse and human RPE cells. In addition, we observed an increase in the expression of Scribble during human RPE development in culture, while it acquires a well-defined basolateral pattern as this process is completed. Finally, the expression and location of Scribble were analyzed in human RPE cells in experimental conditions that mimic the toxic environment suffered by these cells during AMD development and found an increase in Scribble expression in cells that develop a pathological phenotype, suggesting that the protein could be altered in cells under stress conditions, as occurs in AMD. Together, our results demonstrate, for the first time, that Scribble is expressed in both human and mouse RPE and is localized at the basolateral membrane in mature cells. Furthermore, Scribble shows impaired expression and location in RPE cells in pathological conditions, suggesting a possible role for this protein in the development of pathologies, such as AMD.
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Affiliation(s)
- Alicia Segurado
- Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
- Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Plasticity, Degeneration, and Regeneration of the Visual System Group, Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
| | - Alba Rodríguez-Carrillo
- Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
| | - Bárbara Castellanos
- Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
| | - Emiliano Hernández-Galilea
- Plasticity, Degeneration, and Regeneration of the Visual System Group, Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Department of Surgery, Ophthalmology Service, University Hospital of Salamanca, University of Salamanca, Salamanca, Spain
| | - Almudena Velasco
- Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
- Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Plasticity, Degeneration, and Regeneration of the Visual System Group, Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
| | - Concepción Lillo
- Department of Cell Biology and Pathology, University of Salamanca, Salamanca, Spain
- Institute of Neurosciences of Castilla y León (INCyL), University of Salamanca, Salamanca, Spain
- Plasticity, Degeneration, and Regeneration of the Visual System Group, Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- *Correspondence: Concepción Lillo
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27
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Wang K, Chen YS, Chien HW, Chiou HL, Yang SF, Hsieh YH. Melatonin inhibits NaIO3-induced ARPE-19 cell apoptosis via suppression of HIF-1α/BNIP3-LC3B/mitophagy signaling. Cell Biosci 2022; 12:133. [PMID: 35986432 PMCID: PMC9389659 DOI: 10.1186/s13578-022-00879-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 08/10/2022] [Indexed: 11/25/2022] Open
Abstract
Background Age-related macular degeneration (AMD) leads to gradual central vision loss and eventual irreversible blindness. Melatonin, an endogenous hormone, exhibits anti-inflammatory and antitumor effects; however, the role it plays in AMD remains unclear. Herein, we investigated the anti-AMD molecular mechanism of melatonin after sodium iodate (NaIO3) treatment of ARPE-19 cells in vitro and in animal models with the goal of improving the therapeutic effect. Results The in vitro results showed that melatonin protected against NaIO3-induced cell viability decline, mitochondrial dysfunction and apoptosis in ARPE-19 cells, and melatonin also alleviated NaIO3-induced reactive oxygen species (ROS) production, mitochondrial dysfunction and mitophagy activation. Melatonin reduced NaIO3-induced mitophagy activation through HIF-1α-targeted BNIP3/LC3B transcription, whereas ROS inhibition realized with N-acetylcysteine (NAC, a ROS inhibitor) combined with melatonin reduced the effect of NaIO3 on mitophagy. An animal model of AMD was established to confirm the in vitro data. Mouse tail vein injection of NaIO3 and melatonin was associated with enhanced repair of retinal layers within 7 days, as observed by optical coherence tomography (OCT) and hematoxylin and eosin (H&E) staining. A reduction in BNIP3 and HIF-1α levels, as determined by immunohistochemistry (IHC) assay, was also observed. Conclusions These results indicate that melatonin attenuated NaIO3-induced mitophagy of ARPE-19 cells via reduction in ROS-mediated HIF-1α targeted BNIP3/LC3B signaling in vitro and in vivo. Melatonin may be a potential therapeutic drug in the treatment of AMD. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00879-3.
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Mei L, Yu M, Liu Y, Weh E, Pawar M, Li L, Besirli CG, Schwendeman AA. Synthetic high-density lipoprotein nanoparticles delivering rapamycin for the treatment of age-related macular degeneration. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2022; 44:102571. [PMID: 35623563 PMCID: PMC10655893 DOI: 10.1016/j.nano.2022.102571] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 04/25/2022] [Accepted: 05/18/2022] [Indexed: 05/03/2023]
Abstract
Synthetic high-density lipoprotein (sHDL) and rapamycin (Rap) have both been shown to be potential treatments for age-related macular degeneration (AMD). The low aqueous solubility of Rap, however, limits its therapeutic utility. Here we used an Apolipoprotein A-I mimetic peptide and phospholipid-based sHDL for the intravitreal delivery of Rap. By incorporation of Rap in sHDL nanoparticles (sHDL-Rap), we achieve 125-fold increase in drug aqueous concentration. When applied in vitro to retinal pigment epithelium cells, sHDL-Rap exhibited the abilities to efflux cholesterol, neutralize endotoxin, and suppress NF-κB activation. As an mTOR inhibitor, Rap induced autophagy and inhibited NF-κB-mediated pro-inflammatory signaling. Additionally, a greater reduction in lipofuscin accumulation and increased anti-inflammatory effects were achieved by sHDL-Rap relative to free drug or sHDL alone. In vivo studies demonstrated that sHDL reached the target retina pigment epithelium (RPE) layer following intravitreal administration in rats. These results suggest that sHDL-Rap holds potential as a treatment for AMD.
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Affiliation(s)
- Ling Mei
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, United States; Engineering Research Center for Pharmaceuticals and Equipments of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, Chengdu 610106, China
| | - Minzhi Yu
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, United States
| | - Yayuan Liu
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, United States
| | - Eric Weh
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48109, United States
| | - Mercy Pawar
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48109, United States
| | - Li Li
- Department of Pharmaceutical Sciences, Shenyang Pharmaceutical University, China
| | - Cagri G Besirli
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48109, United States
| | - Anna A Schwendeman
- Department of Pharmaceutical Sciences, University of Michigan, Ann Arbor, MI 48109, United States; Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, United States.
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29
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Molins B, Mesquida M, Adan A. Bioengineering approaches for modelling retinal pathologies of the outer blood-retinal barrier. Prog Retin Eye Res 2022:101097. [PMID: 35840488 DOI: 10.1016/j.preteyeres.2022.101097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 05/31/2022] [Accepted: 06/29/2022] [Indexed: 11/18/2022]
Abstract
Alterations of the junctional complex of the outer blood-retinal barrier (oBRB), which is integrated by the close interaction of the retinal pigment epithelium, the Bruch's membrane, and the choriocapillaris, contribute to the loss of neuronal signalling and subsequent vision impairment in several retinal inflammatory disorders such as age-related macular degeneration and diabetic retinopathy. Reductionist approaches into the mechanisms that underlie such diseases have been hindered by the absence of adequate in vitro models using human cells to provide the 3D dynamic architecture that enables expression of the in vivo phenotype of the oBRB. Conventional in vitro cell models are based on 2D monolayer cellular cultures, unable to properly recapitulate the complexity of living systems. The main drawbacks of conventional oBRB models also emerge from the cell sourcing, the lack of an appropriate Bruch's membrane analogue, and the lack of choroidal microvasculature with flow. In the last years, the advent of organ-on-a-chip, bioengineering, and stem cell technologies is providing more advanced 3D models with flow, multicellularity, and external control over microenvironmental properties. By incorporating additional biological complexity, organ-on-a-chip devices can mirror physiologically relevant properties of the native tissue while offering additional set ups to model and study disease. In this review we first examine the current understanding of oBRB biology as a functional unit, highlighting the coordinated contribution of the different components to barrier function in health and disease. Then we describe recent advances in the use of pluripotent stem cells-derived retinal cells, Bruch's membrane analogues, and co-culture techniques to recapitulate the oBRB. We finally discuss current advances and challenges of oBRB-on-a-chip technologies for disease modelling.
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Affiliation(s)
- Blanca Molins
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain.
| | - Marina Mesquida
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain; Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Alfredo Adan
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain; Instituto Clínic de Oftalmología, Hospital Clínic Barcelona, C/ Sabino de Arana 1, 08028, Barcelona, Spain
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30
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Parravano M, Eandi CM, Figus M, Lupidi M, Menchini F, Nicolo' M, Parisi V, Toto L, Viola F, Vujosevic S, Querques G. Effects of circadian rhythm disruption on retinal physiopathology: Considerations from a consensus of experts. Eur J Ophthalmol 2022; 32:2489-2493. [PMID: 35656746 PMCID: PMC9373193 DOI: 10.1177/11206721221106149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The circadian rhythms originate within the organism and synchronize with cyclic
fluctuations in the external environment. It has been demonstrated that part of the human
genome is under control of the circadian clock and that a synchronizer that helps to
maintain daily rhythms is Melatonin, a neuro-hormone primarily synthesized by the pineal
gland during the night. The chronic disruption of circadian rhythm has been linked to many
conditions such as obesity, metabolic syndrome, type 2 diabetes, cancer, and
neurodegenerative diseases. Studies in the mice showed that the disruption of the retinal
circadian rhythm increases the decline during the aging of photoreceptors, accelerating
age-related disruption of cone cell structure, function, and viability and that the
melatonin receptor deletion seems to influence the health of retinal cells, speeding up
their aging. In conclusion, preserving the circadian rhythms could be to add to the
prevention and treatment of age-related degenerative retinal diseases, and although
additional studies are needed, melatonin could be a valid support to favor this
“chronoprotection action”.
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Affiliation(s)
| | - C M Eandi
- Department of Surgical Sciences, University of Torino, Torino, Italy.,Fondation Asile des Aveugles, Jules Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland.,Macula Onlus Foundation, Genoa, Italy
| | - M Figus
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, 9310University of Pisa, Pisa, Italy
| | - M Lupidi
- Macula Onlus Foundation, Genoa, Italy.,Eye Clinic, Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - F Menchini
- Department of Medicine-Ophthalmology, University of Udine, Udine, Italy
| | - M Nicolo'
- Macula Onlus Foundation, Genoa, Italy.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DiNOGMI), 9302University of Genoa, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, University Eye Clinic of Genoa, Genoa, Italy
| | - V Parisi
- 61870IRCCS-Fondazione Bietti, Rome, Italy
| | - L Toto
- Ophthalmic Clinic, Department of Medicine and Science of Ageing, University "G. 9301d'Annunzio" of Chieti-Pescara, Chieti, Italy
| | - F Viola
- Foundation IRCCS Cà Grande Ospedale Maggiore Policlinico, 9304University of Milan, Milan, Italy
| | - S Vujosevic
- Department of Biomedical, Surgical and Dental Sciences University of Milan, Milan, Italy.,Eye Clinic, IRCCS MultiMedica, Milan, Italy
| | - G Querques
- Department of Ophthalmology, IRCCS Ospedale San Raffaele, University Vita-Salute, Milan, Italy
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31
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Kotnala A, Senthilkumari S, Wu G, Stewart TG, Curcio CA, Halder N, Singh SB, Kumar A, Velpandian T. Retinal Pigment Epithelium in Human Donor Eyes Contains Higher Levels of Bisretinoids Including A2E in Periphery than Macula. Invest Ophthalmol Vis Sci 2022; 63:6. [PMID: 35671050 PMCID: PMC9187938 DOI: 10.1167/iovs.63.6.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose With age, human retinal pigment epithelium (RPE) accumulates bisretinoid fluorophores that may impact cellular function and contribute to age-related macular degeneration (AMD). Bisretinoids are comprised of a central pyridinium, dihydropyridinium, or cyclohexadiene ring. The pyridinium bisretinoid A2E has been extensively studied, and its quantity in the macula has been questioned. Age-changes and distributions of other bisretinoids are not well characterized. We measured levels of three bisretinoids and oxidized A2E in macula and periphery in human donor eyes of different ages. Methods Eyes (N = 139 donors, 61 women and 78 men, aged 40–80 years) were dissected into 8 mm diameter macular and temporal periphery punches. Using liquid chromatography – electrospray ionization – mass spectrometry (LC-ESI-MS) and an authentic synthesized standard, we quantified A2E (ng). Using LC-ESI-MS and a 50-eye-extract of A2E, we semiquantified A2E and 3 other compounds (eye extract equivalent units [EEEUs): A2-glycerophosphoethanolamine (A2GPE), dihydropyridine phosphatidyl ethanolamine (A2DHPE), and monofuranA2E (MFA2E). Results A2E quantities in ng and EEEUs were highly correlated (r = 0.97, P < 0.001). From 262 eyes, 5 to 9-fold higher levels were observed in the peripheral retina than in the macula for all assayed compounds. A2E, A2DHPE, and MFA2E increased with age, whereas A2GPE remained unaffected. No significant right-left or male-female differences were detected. Conclusions Significantly higher levels were observed in the periphery than in the macula for all assayed compounds signifying biologic differences between these regions. Levels of oxidized A2E parallel native A2E and not the distribution of retinal illuminance. Data will assist with the interpretion of clinical trial outcomes of agents targeting bisretinoid-related pathways.
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Affiliation(s)
- Ankita Kotnala
- Ocular Pharmacology & Pharmacy Division, All India Institute of Medical Sciences, New Delhi, India
| | - Srinivasan Senthilkumari
- Department of Ocular Pharmacology, Aravind Medical Research Foundation (AMRF), Dr. G. Venkataswamy Eye Research Institute, #1, Anna Nagar, Madurai -20, Tamilnadu, India
| | - Gong Wu
- Department of Biostatics, Vanderbilt University Medical Centre, Nashville, Tennessee, United States
| | - Thomas G Stewart
- Department of Biostatics, Vanderbilt University Medical Centre, Nashville, Tennessee, United States
| | - Christine A Curcio
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Nabanita Halder
- Ocular Pharmacology & Pharmacy Division, All India Institute of Medical Sciences, New Delhi, India
| | | | - Atul Kumar
- Department of Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Thirumurthy Velpandian
- Ocular Pharmacology & Pharmacy Division, All India Institute of Medical Sciences, New Delhi, India
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32
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Fadjukov J, Wienbar S, Hakanen S, Aho V, Vihinen-Ranta M, Ihalainen TO, Schwartz GW, Nymark S. Gap junctions and connexin hemichannels both contribute to the electrical properties of retinal pigment epithelium. J Gen Physiol 2022; 154:213064. [PMID: 35275193 PMCID: PMC8922333 DOI: 10.1085/jgp.202112916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 02/17/2022] [Indexed: 12/13/2022] Open
Abstract
Gap junctions are intercellular channels that permit the transfer of ions and small molecules between adjacent cells. These cellular junctions are particularly dense in the retinal pigment epithelium (RPE), and their contribution to many retinal diseases has been recognized. While gap junctions have been implicated in several aspects of RPE physiology, their role in shaping the electrical properties of these cells has not been characterized in mammals. The role of gap junctions in the electrical properties of the RPE is particularly important considering the growing appreciation of RPE as excitable cells containing various voltage-gated channels. We used a whole-cell patch clamp to measure the electrical characteristics and connectivity between RPE cells, both in cultures derived from human embryonic stem cells and in the intact RPE monolayers from mouse eyes. We found that the pharmacological blockade of gap junctions eliminated electrical coupling between RPE cells, and that the blockade of gap junctions or Cx43 hemichannels significantly increased their input resistance. These results demonstrate that gap junctions function in the RPE not only as a means of molecular transport but also as a regulator of electrical excitability.
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Affiliation(s)
- Julia Fadjukov
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Sophia Wienbar
- Department of Ophthalmology, Northwestern University, Chicago, IL.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL.,Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL
| | - Satu Hakanen
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Vesa Aho
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Maija Vihinen-Ranta
- Department of Biological and Environmental Science and Nanoscience Center, University of Jyväskylä, Jyväskylä, Finland
| | - Teemu O Ihalainen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Gregory W Schwartz
- Department of Ophthalmology, Northwestern University, Chicago, IL.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL.,Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL
| | - Soile Nymark
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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33
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Baba K, Goyal V, Tosini G. Circadian Regulation of Retinal Pigment Epithelium Function. Int J Mol Sci 2022; 23:2699. [PMID: 35269840 PMCID: PMC8910459 DOI: 10.3390/ijms23052699] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 12/22/2022] Open
Abstract
The retinal pigment epithelium (RPE) is a single layer of cells located between the choriocapillaris vessels and the light-sensitive photoreceptors in the outer retina. The RPE performs physiological processes necessary for the maintenance and support of photoreceptors and visual function. Among the many functions performed by the RPE, the timing of the peak in phagocytic activity by the RPE of the photoreceptor outer segments that occurs 1-2 h. after the onset of light has captured the interest of many investigators and has thus been intensively studied. Several studies have shown that this burst in phagocytic activity by the RPE is under circadian control and is present in nocturnal and diurnal species and rod and cone photoreceptors. Previous investigations have demonstrated that a functional circadian clock exists within multiple retinal cell types and RPE cells. However, the anatomical location of the circadian controlling this activity is not clear. Experimental evidence indicates that the circadian clock, melatonin, dopamine, and integrin signaling play a key role in controlling this rhythm. A series of very recent studies report that the circadian clock in the RPE controls the daily peak in phagocytic activity. However, the loss of the burst in phagocytic activity after light onset does not result in photoreceptor or RPE deterioration during aging. In the current review, we summarized the current knowledge on the mechanism controlling this phenomenon and the physiological role of this peak.
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Affiliation(s)
| | | | - Gianluca Tosini
- Department of Pharmacology & Toxicology and Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310-1495, USA; (K.B.); (V.G.)
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34
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Asatryan A, Calandria JM, Kautzmann MAI, Jun B, Gordon WC, Do KV, Bhattacharjee S, Pham TL, Bermúdez V, Mateos MV, Heap J, Bazan NG. New Retinal Pigment Epithelial Cell Model to Unravel Neuroprotection Sensors of Neurodegeneration in Retinal Disease. Front Neurosci 2022; 16:926629. [PMID: 35873810 PMCID: PMC9301569 DOI: 10.3389/fnins.2022.926629] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/30/2022] [Indexed: 01/02/2023] Open
Abstract
Retinal pigment epithelial (RPE) cells sustain photoreceptor integrity, and when this function is disrupted, retinal degenerations ensue. Herein, we characterize a new cell line from human RPE that we termed ABC. These cells remarkably recapitulate human eye native cells. Distinctive from other epithelia, RPE cells originate from the neural crest and follow a neural development but are terminally differentiated into "epithelial" type, thus sharing characteristics with their neuronal lineages counterparts. Additionally, they form microvilli, tight junctions, and honeycomb packing and express distinctive markers. In these cells, outer segment phagocytosis, phagolysosome fate, phospholipid metabolism, and lipid mediator release can be studied. ABC cells display higher resistance to oxidative stress and are protected from senescence through mTOR inhibition, making them more stable in culture. The cells are responsive to Neuroprotectin D1 (NPD1), which downregulates inflammasomes and upregulates antioxidant and anti-inflammatory genes. ABC gene expression profile displays close proximity to native RPE lineage, making them a reliable cell system to unravel signaling in uncompensated oxidative stress (UOS) and retinal degenerative disease to define neuroprotection sites.
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Affiliation(s)
- Aram Asatryan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Jorgelina M Calandria
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Marie-Audrey I Kautzmann
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - William C Gordon
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Khanh V Do
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Surjyadipta Bhattacharjee
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Thang L Pham
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Vicente Bermúdez
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Melina Valeria Mateos
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Jessica Heap
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
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35
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Caveolin-1 Down-Regulation Reduces VEGF-A Secretion Induced by IGF-1 in ARPE-19 Cells. Life (Basel) 2021; 12:life12010044. [PMID: 35054437 PMCID: PMC8781830 DOI: 10.3390/life12010044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 11/16/2022] Open
Abstract
The insulin-like growth factor 1 (IGF-1) stimulates expression and secretion of vascular endothelial growth factor-A (VEGF-A), the main actor in ocular neovascularization, by RPE cells. Activity of IGF-1 is regulated by interaction between its receptor and Caveolin-1 (Cav-1), the main component of caveolae. The aim of this study was to investigate whether modulation of Cav-1 expression affects synthesis and secretion of VEGF-A. ARPE-19 cells were transfected with small interfering RNA for Cav-1 (si-Cav-1) and with control siRNA (si-CTR) and stimulated with IGF-1. We found that down-regulation of Cav-1 did not affect activation of IGF-1R but regulated in an opposite manner the phosphorylation of Akt and Erk1/2. Moreover, we found that IGF-1 increased mRNA levels of VEGF-A in both si-CTR and in si-Cav-1 ARPE-19 cells and that Cav-1 silencing significantly reduced basal and IGF-1-stimulated VEGF-A release. Then we investigated the response of the microvascular endothelial cell line HMEC-1 to secretory products of ARPE-19 cells by evaluating wound healing closure, finding that conditioned media from si-Cav-1-ARPE-19 cells reduced endothelial cell migration rate. These data demonstrate that Cav-1 regulates secretion of VEGF-A, and that the depletion of Cav-1 reduces IGF-1 induced VEGF-A secretion in ARPE-19 cells and the migratory potential of their secretory products.
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Tichotová L, Studenovska H, Petrovski G, Popelka Š, Nemesh Y, Sedláčková M, Drutovič S, Rohiwal S, Jendelová P, Erceg S, Brymová A, Artero‐Castro A, Lytvynchuk L, Straňák Z, Ellederová Z, Motlík J, Ardan T. Advantages of nanofibrous membranes for culturing of primary RPE cells compared to commercial scaffolds. Acta Ophthalmol 2021; 100:e1172-e1185. [PMID: 34687141 DOI: 10.1111/aos.15034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 09/22/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Dysfunction of the retinal pigment epithelium (RPE) causes numerous forms of retinal degeneration. RPE replacement is a modern option to save vision. We aimed to test the results of transplanting cultured RPEs on biocompatible membranes. METHODS We cultivated porcine primary RPE cells isolated from cadaver eyes from the slaughterhouse on two types of membranes: commercial polyester scaffolds Transwell (Corning Inc., Kenneburg, ME, USA) with 0.4 µm pore size and prepared Poly (L-lactide-co-DL-lactide) (PDLLA) nanofibrous membranes with an average pore size of 0.4 µm. RESULTS Five types of assays were used for the analysis: immunocytochemistry (ICC), phagocytosis assay, Western blotting, real-time qPCR (RT-qPCR) and electron microscopy. RT-qPCR demonstrated that RPEs cultured on nanofibrous membranes have higher expressions of BEST1 (bestrophin 1), RLBP1 (retinaldehyde-binding protein 1), RPE65 (retinal pigment epithelium-specific 65 kDa protein), PAX6 (transcription factor PAX6), SOX9 (transcription factor SOX9), DCT (dopachrome tautomerase) and MITF (microphthalmia-associated transcription factor). ICC of the RPEs cultured on nanofibrous membranes showed more intensive staining of markers such as BEST1, MCT1 (monocarboxylate transporter 1), Na+ /K+ ATPase, RPE65 and acetylated tubulin in comparison with commercial ones. Additionally, the absence of α-SMA proved the stability of the RPE polarization state and the absence of epithelial-to-mesenchymal transition. RPE possessed high phagocytic activity. Electron microscopy of both membranes confirmed a confluent layer of RPE cells and their genuine morphological structure, which was comparable to native RPEs. CONCLUSIONS Retinal pigment epitheliums cultured on polylactide nanofibrous membranes improved the final quality of the cell product by having better maturation and long-term survival of the RPE monolayer compared to those cultured on commercial polyester scaffolds. PDLLA-cultured RPEs are a plausible source for the replacement of non-functioning RPEs during cell therapy.
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Affiliation(s)
- Lucie Tichotová
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Cell Biology Faculty of Science Charles University Prague Czech Republic
| | - Hana Studenovska
- Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Goran Petrovski
- Center for Eye Research Department of Ophthalmology Oslo University Hospital and Institute for Clinical Medicine University of Oslo Oslo Norway
| | - Štěpán Popelka
- Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Yaroslav Nemesh
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Cell Biology Faculty of Science Charles University Prague Czech Republic
| | - Miroslava Sedláčková
- Department of Histology and Embryology Faculty of Medicine Masaryk University Brno Czech Republic
| | - Saskia Drutovič
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Sonali Rohiwal
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Pavla Jendelová
- Institute of Experimental Medicine Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Slaven Erceg
- Institute of Experimental Medicine Academy of Sciences of the Czech Republic Prague Czech Republic
- Stem Cell Therapies in Neurodegenerative Diseases Lab Research Center ‘Principe Felipe’ Valencia Spain
| | - Anna Brymová
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
- Department of Cell Biology Faculty of Science Charles University Prague Czech Republic
| | - Ana Artero‐Castro
- Stem Cell Therapies in Neurodegenerative Diseases Lab Research Center ‘Principe Felipe’ Valencia Spain
| | - Lyubomyr Lytvynchuk
- Department of Ophthalmology Justus‐Liebig‐University Giessen University Hospital Giessen and Marburg Giessen Germany
| | - Zbyněk Straňák
- Ophthalmology Department of 3rd Faculty of Medicine Charles University and University Hospital Kralovske Vinohrady Prague Czech Republic
- Third Faculty of Medicine Charles University Prague Czech Republic
| | - Zdeňka Ellederová
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Jan Motlík
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
| | - Taras Ardan
- Institute of Animal Physiology and Genetics Academy of Sciences of the Czech Republic Libechov Czech Republic
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Murray IJ, Rodrigo-Diaz E, Kelly JMF, Tahir HJ, Carden D, Patryas L, Parry NR. The role of dark adaptation in understanding early AMD. Prog Retin Eye Res 2021; 88:101015. [PMID: 34626782 DOI: 10.1016/j.preteyeres.2021.101015] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/24/2021] [Accepted: 09/29/2021] [Indexed: 11/27/2022]
Abstract
The main aim of the paper is to discuss current knowledge on how Age Related Macular Degeneration (AMD) affects Dark Adaptation (DA). The paper is divided into three parts. Firstly, we outline some of the molecular mechanisms that control DA. Secondly, we review the psychophysical issues and the corresponding analytical techniques. Finally, we characterise the link between slowed DA and the morphological abnormalities in early AMD. Historically, DA has been regarded as too cumbersome for widespread clinical application. Yet the technique is extremely useful; it is widely accepted that the psychophysically obtained slope of the second rod-mediated phase of the dark adaptation function is an accurate assay of photoreceptor pigment regeneration kinetics. Technological developments have prompted new ways of generating the DA curve, but analytical problems remain. A simple potential solution to these, based on the application of a novel fast mathematical algorithm, is presented. This allows the calculation of the parameters of the DA curve in real time. Improving current management of AMD will depend on identifying a satisfactory endpoint for evaluating future therapeutic strategies. This must be implemented before the onset of severe disease. Morphological changes progress too slowly to act as a satisfactory endpoint for new therapies whereas functional changes, such as those seen in DA, may have more potential in this regard. It is important to recognise, however, that the functional changes are not confined to rods and that building a mathematical model of the DA curve enables the separation of rod and cone dysfunction and allows more versatility in terms of the range of disease severity that can be monitored. Examples are presented that show how analysing the DA curve into its constituent components can improve our understanding of the morphological changes in early AMD.
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Affiliation(s)
- Ian J Murray
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK.
| | - Elena Rodrigo-Diaz
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Jeremiah M F Kelly
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Humza J Tahir
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - David Carden
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Laura Patryas
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Neil Ra Parry
- Vision Science Lab., Faculty of Biology, Medicine and Health, University of Manchester, UK; Vision Science Centre, Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
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The 3D organisation of mitochondria in primate photoreceptors. Sci Rep 2021; 11:18863. [PMID: 34552195 PMCID: PMC8458444 DOI: 10.1038/s41598-021-98409-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/17/2021] [Indexed: 11/08/2022] Open
Abstract
Vertebrate photoreceptors contain large numbers of closely-packed mitochondria which sustain the high metabolic demands of these cells. These mitochondria populations are dynamic and undergo fusion and fission events. This activity serves to maintain the population in a healthy state. In the event of mitochondrial damage, sub-domains, or indeed whole mitochondria, can be degraded and population homeostasis achieved. If this process is overwhelmed cell death may result. Death of photoreceptors contributes to loss of vision in aging individuals and is associated with many eye diseases. In this study we used serial block face scanning electron microscopy of adult Macaca fascicularis retinae to examine the 3D structure of mitochondria in rod and cone photoreceptors. We show that healthy-looking photoreceptors contain mitochondria exhibiting a range of shapes which are associated with different regions of the cell. In some photoreceptors we observe mitochondrial swelling and other changes often associated with cellular stress. In rods and cones that appear stressed we identify elongated domains of mitochondria with densely-packed normal cristae associated with photoreceptor ciliary rootlet bundles. We observe mitochondrial fission and mitochondrion fragments localised to these domains. Swollen mitochondria with few intact cristae are located towards the periphery of the photoreceptor inner-segment in rods, whilst they are found throughout the cell in cones. Swollen mitochondria exhibit sites on the mitochondrial inner membrane which have undergone complex invagination resulting in membranous, electron-dense aggregates. Membrane contact occurs between the mitochondrion and the photoreceptor plasma membrane in the vicinity of these aggregates, and a series of subsequent membrane fusions results in expulsion of the mitochondrial aggregate from the photoreceptor. These events are primarily associated with rods. The potential fate of this purged material and consequences of its clearance by retinal pigment epithelia are discussed.
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Sroy S, Servent A, Sriwichai W, In S, Avallone S. Use of an experimental design to optimise the saponification reaction and the quantification of vitamins A 1 and A 2 in whole fish. INT J VITAM NUTR RES 2021. [PMID: 34542320 DOI: 10.1024/0300-9831/a000729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In ASEAN countries, small freshwater fish species contribute to the nutritional needs of people with few livelihoods by providing them with significant amounts of protein, fat, vitamins and minerals. Some species are eaten whole (with their organs, skin, bones, head and eyes). To estimate the vitamin A content of these foods, conventional saponification has been applied but has not been able to fully release the retinol. Our objective was to optimise the conditions of vitamin A saponification in whole fish to have a reliable estimate of their contribution to intakes. The effects of temperature and saponification time on the retinol quantification of whole fish were evaluated using a two-factor experimental design. Reaction time had a significant effect on the saponification of standard retinyl palmitate and whole fish (p≤0.05). For whole fish, the best conditions for the saponification were to heat the samples to 80 °C for 43 minutes. Under these conditions, the retinol is well liberated from the matrix and protected from degradation and isomerisation reactions. The time-temperature couple used is more intense than that recommended for quantifying vitamin A in milk or enriched margarines. The protective effect of the food matrix against the release of retinol is evident. Vitamin A2 alcohol (3,4-didehydroretinol) was detected in five species and the overall vitamin A contents ranged from 9.6 to 737.5 μg RE/100 g in species frequently consumed in Cambodia. The two species of small fish consumed whole were the ones that contained significantly more vitamin A among the ten tested (p≤0.05). Highlights: Vitamin A2 alcohol was quantified in five fish species. The official saponification partially released retinol in whole fish. The optimised reaction required heating the sample to 80 °C for 43 min.
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Affiliation(s)
- Sengly Sroy
- QualiSud, Univ Montpellier, CIRAD, Institut Agro, Université d'Avignon, Université de la Réunion, Montpellier, France.,Faculty of Chemical and Food Engineering, Institute of Technology of Cambodia, Phnom Penh, Cambodia
| | - Adrien Servent
- QualiSud, Univ Montpellier, CIRAD, Institut Agro, Université d'Avignon, Université de la Réunion, Montpellier, France.,CIRAD, UMR Qualisud, Montpellier, France
| | - Wichien Sriwichai
- King Mongkut's University of Technology North Bangkok, Faculty of Agro-Industry, Department of Innovation and Technology of Product Development, Prachinburi, Thailand
| | - Sokneang In
- Faculty of Chemical and Food Engineering, Institute of Technology of Cambodia, Phnom Penh, Cambodia
| | - Sylvie Avallone
- QualiSud, Univ Montpellier, CIRAD, Institut Agro, Université d'Avignon, Université de la Réunion, Montpellier, France
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Hsp90-associated DNA replication checkpoint protein and proteasome-subunit components are involved in the age-related macular degeneration. Chin Med J (Engl) 2021; 134:2322-2332. [PMID: 34629418 PMCID: PMC8510006 DOI: 10.1097/cm9.0000000000001773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Background: Age-related macular degeneration (AMD) is the leading cause of vision loss worldwide. However, the mechanisms involved in the development and progression of AMD are poorly delineated. We aimed to explore the critical genes involved in the progression of AMD. Methods: The differentially expressed genes (DEGs) in AMD retinal pigment epithelial (RPE)/choroid tissues were identified using the microarray datasets GSE99248 and GSE125564, which were downloaded from the gene expression omnibus database. The overlapping DEGs from the two datasets were screened to identify DEG-related biological pathways using gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. The hub genes were identified from these DEGs through protein-protein interaction network analyses. The expression levels of hub genes were evaluated by quantitative real-time polymerase chain reaction following the induction of senescence in ARPE-19 with FK866. Following the identification of AMD-related key genes, the potential small molecule compounds targeting the key genes were predicted by PharmacoDB. Finally, a microRNA-gene interaction network was constructed. Results: Microarray analyses identified 174 DEGs in the AMD RPE compared to the healthy RPE samples. These DEGs were primarily enriched in the pathways involved in the regulation of DNA replication, cell cycle, and proteasome-mediated protein polyubiquitination. Among the top ten hub genes, HSP90AA1, CHEK1, PSMA4, PSMD4, and PSMD8 were upregulated in the senescent ARPE-19 cells. Additionally, the drugs targeting HSP90AA1, CHEK1, and PSMA4 were identified. We hypothesize that Hsa-miR-16-5p might target four out of the five key DEGs in the AMD RPE. Conclusions: Based on our findings, HSP90AA1 is likely to be a central gene controlling the DNA replication and proteasome-mediated polyubiquitination during the RPE senescence observed in the progression of AMD. Targeting HSP90AA1, CHEK1, PSMA4, PSMD4, and/or PSMD8 genes through specific miRNAs or small molecules might potentially alleviate the progression of AMD through attenuating RPE senescence.
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Guerra MH, Yumnamcha T, Singh LP, Ibrahim AS. Relative Contribution of Different Mitochondrial Oxidative Phosphorylation Components to the Retinal Pigment Epithelium Barrier Function: Implications for RPE-Related Retinal Diseases. Int J Mol Sci 2021; 22:8130. [PMID: 34360894 PMCID: PMC8348500 DOI: 10.3390/ijms22158130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/19/2021] [Accepted: 07/23/2021] [Indexed: 12/19/2022] Open
Abstract
Disruption of retinal pigment epithelial (RPE) barrier integrity is involved in the pathology of several blinding retinal diseases including age-related macular degeneration (AMD) and diabetic retinopathy (DR), but the underlying causes and pathophysiology are not completely well-defined. Mitochondria dysfunction has often been considered as a potential candidate implicated in such a process. In this study, we aimed to dissect the role of different mitochondrial components; specifically, those of oxidative phosphorylation (OxPhos), in maintaining the barrier functionality of RPE. Electric cell-substrate impedance sensing (ECIS) technology was used to collect multi-frequency electrical impedance data to assess in real-time the barrier formation of the RPE cells. For this purpose, the human retinal pigment epithelial cell line-ARPE-19-was used and treated with varying concentrations of specific mitochondrial inhibitors that target different steps in OxPhos: Rotenone for complex I (the largest protein complex in the electron transport chain (ETC)); oligomycin for ATP synthase; and carbonyl cyanide-p-trifluoromethoxyphenyl hydrazone (FCCP) for uncoupling ATP synthesis from the accompanying ETC. Furthermore, data were modeled using the ECIS-Zθ software to investigate in depth the effects of these inhibitors on three separate barrier parameters: cell-cell interactions (Rb), cell-matrix interactions (α), and the cell membrane capacitance (Cm). The viability of ARPE-19 cells was determined by lactate dehydrogenase (LDH) Cytotoxicity Assay. The ECIS program's modeling demonstrated that FCCP and thus OxPhos uncoupling disrupt the barrier function in the ARPE-19 cells across all three components of the total resistance (Rb, α, and Cm) in a dose-dependent manner. On the other hand, oligomycin and thus ATP synthase inhibition mostly affects the ARPE-19 cells' attachment to their substrate evident by a significant decrease in α resistance in a dose-dependent manner, both at the end and throughout the duration of the experiment. On the contrary, rotenone and complex I inhibition mostly affect the ARPE-19 paracellular resistance Rb in a dose-dependent manner compared to basolateral resistance α or Cm. Our results clearly demonstrate differential roles for different mitochondrial components in maintaining RPE cell functionality in which uncoupling of OxPhos is a major contributing factor to the disruption barrier function. Such differences can be used in investigating gene expression as well as for screening of selective agents that improve the OxPhos coupling efficiency to be used in the therapeutic approach for treating RPE-related retinal diseases.
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Affiliation(s)
- Michael H. Guerra
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (L.P.S.)
| | - Thangal Yumnamcha
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (L.P.S.)
| | - Lalit P. Singh
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (L.P.S.)
| | - Ahmed S. Ibrahim
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, 540 East Canfield, Detroit, MI 48201, USA; (M.H.G.); (T.Y.); (L.P.S.)
- Department of Pharmacology, School of Medicine, Wayne State University, 540 East Canfield, Detroit, MI 48201, USA
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
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Zhao CY, Ji DW, Zheng H, He GC, Liu H, Hu YC, Chen QA. Pd-Catalyzed Redox Divergent Coupling of Ketones with Terpenols. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01488] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Chao-Yang Zhao
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Ding-Wei Ji
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
| | - Hao Zheng
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Gu-Cheng He
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Heng Liu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Yan-Cheng Hu
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
| | - Qing-An Chen
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People’s Republic of China
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Mann A, Lydon F, Tighe BJ, Suzuki S, Chirila TV. A study of the permeation and water-structuring behavioural properties of PEG modified hydrated silk fibroin membranes. Biomed Phys Eng Express 2021; 7. [PMID: 33930887 DOI: 10.1088/2057-1976/abfd82] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 04/30/2021] [Indexed: 12/19/2022]
Abstract
The potential of naturally occurring substances as a source of biomedical materials is well-recognised and is being increasingly exploited. Silk fibroin membranes derived fromBombyx morisilk cocoons exemplify this, for example as substrata for the growth of ocular cells with the aim of generating biomaterial-cell constructs for tissue engineering. This study investigated the transport properties of selected silk fibroin membranes under conditions that allowed equilibrium hydration of the membranes to be maintained. The behaviour of natural fibroin membranes was compared with fibroin membranes that have been chemically modified with poly(ethylene glycol). The permeation of the smaller hydrated sodium ion was higher than that of the hydrated calcium ion for all three ethanol treated membranes investigated. The PEG and HRP-modified C membrane, which had the highest water content at 59.6 ± 1.5% exhibited the highest permeation of the three membranes at 95.7 ± 2.8 × 10-8cm2s-1compared with 17.9 ± 0.9 × 10-8cm2s-1and 8.7 ± 1.7 × 10-8cm2s-1for membranes A and B respectively for the NaCl permeant. Poly(ethylene glycol) was used to increase permeability while exploiting the crosslinking capabilities of horseradish peroxidase to increase the compressive strength of the membrane. Importantly, we have established that the permeation behaviour of water-soluble permeants with hydrated radii in the sub-nanometer range is analogous to that of conventional hydrogel polymers.
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Affiliation(s)
- Aisling Mann
- Biomaterials Research Unit, Chemical Engineering and Applied Chemistry, College of Engineering and Physical Sciences, Aston University, Birmingham, B4 7ET, United Kingdom
| | - Fiona Lydon
- Biomaterials Research Unit, Chemical Engineering and Applied Chemistry, College of Engineering and Physical Sciences, Aston University, Birmingham, B4 7ET, United Kingdom
| | - Brian J Tighe
- Biomaterials Research Unit, Chemical Engineering and Applied Chemistry, College of Engineering and Physical Sciences, Aston University, Birmingham, B4 7ET, United Kingdom
| | - Shuko Suzuki
- Queensland Eye Institute, South Brisbane, Queensland 4101, Australia
| | - Traian V Chirila
- Queensland Eye Institute, South Brisbane, Queensland 4101, Australia.,Science & Engineering Faculty, Queensland University of Technology, Brisbane, Queensland 4001, Australia.,Faculty of Medicine, University of Queensland, Herston, Queensland 4029, Australia.,Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland 4072, Australia.,Faculty of Science, University of Western Australia, Crawley, Western Australia 6009, Australia
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44
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Armento A, Ueffing M, Clark SJ. The complement system in age-related macular degeneration. Cell Mol Life Sci 2021; 78:4487-4505. [PMID: 33751148 PMCID: PMC8195907 DOI: 10.1007/s00018-021-03796-9] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/05/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration (AMD) is a chronic and progressive degenerative disease of the retina, which culminates in blindness and affects mainly the elderly population. AMD pathogenesis and pathophysiology are incredibly complex due to the structural and cellular complexity of the retina, and the variety of risk factors and molecular mechanisms that contribute to disease onset and progression. AMD is driven by a combination of genetic predisposition, natural ageing changes and lifestyle factors, such as smoking or nutritional intake. The mechanism by which these risk factors interact and converge towards AMD are not fully understood and therefore drug discovery is challenging, where no therapeutic attempt has been fully effective thus far. Genetic and molecular studies have identified the complement system as an important player in AMD. Indeed, many of the genetic risk variants cluster in genes of the alternative pathway of the complement system and complement activation products are elevated in AMD patients. Nevertheless, attempts in treating AMD via complement regulators have not yet been successful, suggesting a level of complexity that could not be predicted only from a genetic point of view. In this review, we will explore the role of complement system in AMD development and in the main molecular and cellular features of AMD, including complement activation itself, inflammation, ECM stability, energy metabolism and oxidative stress.
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Affiliation(s)
- Angela Armento
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.
| | - Simon J Clark
- Department for Ophthalmology, Institute for Ophthalmic Research, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Department for Ophthalmology, University Eye Clinic, Eberhard Karls University of Tübingen, Tübingen, Germany.
- Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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Dewell TE, Gjoni K, Liu AZ, Libby ARG, Moore AT, So PL, Conklin BR. Transcription factor overexpression drives reliable differentiation of retinal pigment epithelium from human induced pluripotent stem cells. Stem Cell Res 2021; 53:102368. [PMID: 34087997 DOI: 10.1016/j.scr.2021.102368] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/10/2021] [Accepted: 04/21/2021] [Indexed: 12/13/2022] Open
Abstract
Age-related macular degeneration and genetic forms of blindness such as Best Disease and Retinitis Pigmentosa can be caused by degeneration of the Retinal Pigment Epithelium (RPE). RPE generated from patient-derived induced pluripotent stem cells (iPSCs) is valuable for both the study of disease mechanisms and development of therapeutic strategies. However, protocols to produce iPSC-derived RPE in vitro are often inefficient, labor-intensive, low-throughput, and highly variable between cell lines and within batches. Here, we report a robust, scalable method to generate iPSC-RPE using doxycycline-inducible expression of eye field transcription factors OTX2, PAX6 and MITF paired with RPE-permissive culture media. Doxycycline addition induces exogenous expression of these transcription factors in Best Disease patient- and wildtype iPSCs to efficiently produce monolayers of RPE with characteristic morphology and gene expression. Further, these RPE monolayers display functionality features including light absorption via pigmentation, polarity-driven fluid transport, and phagocytosis. With this method, we achieve a highly efficient and easily scalable differentiation without the need for mechanical isolation or enrichment methods, generating RPE cultures applicable for in vitro studies.
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Affiliation(s)
- Tessa E Dewell
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Ketrin Gjoni
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Angela Z Liu
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Ashley R G Libby
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA; Developmental and Stem Cell Biology Program, University of California, 1675 Owens St, San Francisco, CA 94158, USA
| | - Anthony T Moore
- UCSF Department of Ophthalmology, 10 Koret Way, San Francisco, CA 94143-0730, USA
| | - Po-Lin So
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA; Innovative Genomics Institute, 2151 Berkeley Way, Berkeley, CA 94720, USA; Gladstone Institutes Stem Cell Core, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Bruce R Conklin
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA; UCSF Department of Ophthalmology, 10 Koret Way, San Francisco, CA 94143-0730, USA; Innovative Genomics Institute, 2151 Berkeley Way, Berkeley, CA 94720, USA; UCSF Department of Medicine, 535 Mission Bay Blvd South, San Francisco, CA 94158, USA.
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46
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Hughes LD, Wang Y, Meli AP, Rothlin CV, Ghosh S. Decoding Cell Death: From a Veritable Library of Babel to Vade Mecum? Annu Rev Immunol 2021; 39:791-817. [PMID: 33902311 DOI: 10.1146/annurev-immunol-102819-072601] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Programmed cell death (PCD) is a requisite feature of development and homeostasis but can also be indicative of infections, injuries, and pathologies. In concordance with these heterogeneous contexts, an array of disparate effector responses occur downstream of cell death and its clearance-spanning tissue morphogenesis, homeostatic turnover, host defense, active dampening of inflammation, and tissue repair. This raises a fundamental question of how a single contextually appropriate response ensues after an event of PCD. To explore how complex inputs may together tailor the specificity of the resulting effector response, here we consider (a) the varying contexts during which different cell death modalities are observed, (b) the nature of the information that can be passed on by cell corpses, and (c) the ways by which efferocyte populations synthesize signals from dying cells with those from the surrounding microenvironment.
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Affiliation(s)
- Lindsey D Hughes
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , ,
| | - Yaqiu Wang
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , ,
| | - Alexandre P Meli
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , ,
| | - Carla V Rothlin
- Department of Immunobiology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; , , , .,Department of Pharmacology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA;
| | - Sourav Ghosh
- Department of Pharmacology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA; .,Department of Neurology, School of Medicine, Yale University, New Haven, Connecticut 06520, USA
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47
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Viegas FO, Neuhauss SCF. A Metabolic Landscape for Maintaining Retina Integrity and Function. Front Mol Neurosci 2021; 14:656000. [PMID: 33935647 PMCID: PMC8081888 DOI: 10.3389/fnmol.2021.656000] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/22/2021] [Indexed: 01/27/2023] Open
Abstract
Neurons have high metabolic demands that are almost exclusively met by glucose supplied from the bloodstream. Glucose is utilized in complex metabolic interactions between neurons and glia cells, described by the astrocyte-neuron lactate shuttle (ANLS) hypothesis. The neural retina faces similar energy demands to the rest of the brain, with additional high anabolic needs to support continuous renewal of photoreceptor outer segments. This demand is met by a fascinating variation of the ANLS in which photoreceptors are the central part of a metabolic landscape, using glucose and supplying surrounding cells with metabolic intermediates. In this review we summarize recent evidence on how neurons, in particular photoreceptors, meet their energy and biosynthetic requirements by comprising a metabolic landscape of interdependent cells.
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Affiliation(s)
- Filipe O Viegas
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Life Science Zurich Graduate School, Ph.D. Program in Molecular Life Sciences, Zurich, Switzerland
| | - Stephan C F Neuhauss
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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48
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Xie J, Jusuf PR, Bui BV, Dudczig S, Sztal TE, Goodbourn PT. Altered Visual Function in a Larval Zebrafish Knockout of Neurodevelopmental Risk Gene pdzk1. Invest Ophthalmol Vis Sci 2021; 62:29. [PMID: 33749720 PMCID: PMC7991922 DOI: 10.1167/iovs.62.3.29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The human PDZK1 gene is located in a genomic susceptibility region for neurodevelopmental disorders. A genome-wide association study identified links between PDZK1 polymorphisms and altered visual contrast sensitivity, an endophenotype for schizophrenia and autism spectrum disorder. The PDZK1 protein is implicated in neurological functioning, interacting with synaptic molecules including postsynaptic density 95 (PSD-95), N-methyl-d-aspartate receptors (NMDARs), corticotropin-releasing factor receptor 1 (CRFR1), and serotonin 2A receptors. The purpose of the present study was to elucidate the role of PDZK1. Methods We generated pdzk1-knockout (pdzk1-KO) zebrafish using CRISPR/Cas-9 genome editing. Visual function of 7-day-old fish was assessed at behavioral and functional levels using the optomotor response and scotopic electroretinogram (ERG). We also quantified retinal morphology and densities of PSD-95, NMDAR1, CRFR1, and serotonin in the synaptic inner plexiform layer at 7 days, 4 weeks, and 8 weeks of age. Standard RT-PCR and nonsense-mediated decay interference treatment were also performed to assess genetic compensation in mutants. Results Relative to wild-type, pdzk1-KO larvae showed spatial frequency tuning functions with increased amplitude (likely due to abnormal gain control) and reduced ERG b-waves (suggestive of inner retinal dysfunction). No synaptic phenotypes, but possible morphological retinal phenotypes, were identified. We confirmed that the absence of major histological phenotypes was not attributable to genetic compensatory mechanisms. Conclusions Our findings point to a role for pdzk1 in zebrafish visual function, and our model system provides a platform for investigating other genes associated with abnormal visual behavior.
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Affiliation(s)
- Jiaheng Xie
- School of BioSciences, The University of Melbourne, Melbourne, Australia
| | - Patricia R Jusuf
- School of BioSciences, The University of Melbourne, Melbourne, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Stefanie Dudczig
- School of BioSciences, The University of Melbourne, Melbourne, Australia
| | - Tamar E Sztal
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Patrick T Goodbourn
- Melbourne School of Psychological Sciences, The University of Melbourne, Melbourne, Australia
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Wu DM, Ji X, Ivanchenko MV, Chung M, Piper M, Rana P, Wang SK, Xue Y, West E, Zhao SR, Xu H, Cicconet M, Xiong W, Cepko CL. Nrf2 overexpression rescues the RPE in mouse models of retinitis pigmentosa. JCI Insight 2021; 6:145029. [PMID: 33491671 PMCID: PMC7934854 DOI: 10.1172/jci.insight.145029] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
Nrf2, a transcription factor that regulates the response to oxidative stress, has been shown to rescue cone photoreceptors and slow vision loss in mouse models of retinal degeneration (rd). The retinal pigment epithelium (RPE) is damaged in these models, but whether it also could be rescued by Nrf2 has not been previously examined. We used an adeno-associated virus (AAV) with an RPE-specific (Best1) promoter to overexpress Nrf2 in the RPE of rd mice. Control rd mice showed disruption of the regular array of the RPE, as well as loss of RPE cells. Cones were lost in circumscribed regions within the cone photoreceptor layer. Overexpression of Nrf2 specifically in the RPE was sufficient to rescue the RPE, as well as the disruptions in the cone photoreceptor layer. Electron microscopy showed compromised apical microvilli in control rd mice but showed preserved microvilli in Best1-Nrf2–treated mice. The rd mice treated with Best1-Nrf2 had slightly better visual acuity. Transcriptome profiling showed that Nrf2 upregulates multiple oxidative defense pathways, reversing declines seen in the glutathione pathway in control rd mice. In summary, Nrf2 overexpression in the RPE preserves RPE morphology and survival in rd mice, and it is a potential therapeutic for diseases involving RPE degeneration, including age-related macular degeneration (AMD).
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Affiliation(s)
- David M Wu
- Massachusetts Eye and Ear Infirmary Retina Service, Department of Ophthalmology.,Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Xuke Ji
- Massachusetts Eye and Ear Infirmary Retina Service, Department of Ophthalmology.,Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Maryna V Ivanchenko
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Michelle Chung
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Mary Piper
- Department of Bioinformatics, T.H. Chan Harvard School of Public Health, Boston, Massachusetts, USA
| | - Parimal Rana
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Sean K Wang
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Yunlu Xue
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Emma West
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Sophia R Zhao
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and
| | - Hongbin Xu
- Departments of Genetics and Ophthalmology, Blavatnik Institute, and.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Marcelo Cicconet
- Image and Data Analysis Core, Harvard Medical School, Boston, Massachusetts, USA
| | - Wenjun Xiong
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Constance L Cepko
- Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, USA.,Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
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50
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Intartaglia D, Giamundo G, Conte I. The Impact of miRNAs in Health and Disease of Retinal Pigment Epithelium. Front Cell Dev Biol 2021; 8:589985. [PMID: 33520981 PMCID: PMC7844312 DOI: 10.3389/fcell.2020.589985] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/17/2020] [Indexed: 12/17/2022] Open
Abstract
MicroRNAs (miRNAs), a class of non-coding RNAs, are essential key players in the control of biological processes in both physiological and pathological conditions. miRNAs play important roles in fine tuning the expression of many genes, which often have roles in common molecular networks. miRNA dysregulation thus renders cells vulnerable to aberrant fluctuations in genes, resulting in degenerative diseases. The retinal pigment epithelium (RPE) is a monolayer of polarized pigmented epithelial cells that resides between the light-sensitive photoreceptors (PR) and the choriocapillaris. The demanding physiological functions of RPE cells require precise gene regulation for the maintenance of retinal homeostasis under stress conditions and the preservation of vision. Thus far, our understanding of how miRNAs function in the homeostasis and maintenance of the RPE has been poorly addressed, and advancing our knowledge is central to harnessing their potential as therapeutic agents to counteract visual impairment. This review focuses on the emerging roles of miRNAs in the function and health of the RPE and on the future exploration of miRNA-based therapeutic approaches to counteract blinding diseases.
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Affiliation(s)
| | | | - Ivan Conte
- Telethon Institute of Genetics and Medicine, Naples, Italy
- Department of Biology, Polytechnic and Basic Sciences School, University of Naples Federico II, Naples, Italy
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