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Martins B, Pires M, Ambrósio AF, Girão H, Fernandes R. Contribution of extracellular vesicles for the pathogenesis of retinal diseases: shedding light on blood-retinal barrier dysfunction. J Biomed Sci 2024; 31:48. [PMID: 38730462 PMCID: PMC11088087 DOI: 10.1186/s12929-024-01036-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/30/2024] [Indexed: 05/12/2024] Open
Abstract
Retinal degenerative diseases, including diabetic retinopathy (DR) and age-related macular degeneration (AMD), loom as threats to vision, causing detrimental effects on the structure and function of the retina. Central to understanding these diseases, is the compromised state of the blood-retinal barrier (BRB), an effective barrier that regulates the influx of immune and inflammatory components. Whether BRB breakdown initiates retinal distress, or is a consequence of disease progression, remains enigmatic. Nevertheless, it is an indication of retinal dysfunction and potential vision loss.The intricate intercellular dialogues among retinal cell populations remain unintelligible in the complex retinal milieu, under conditions of inflammation and oxidative stress. The retina, a specialized neural tissue, sustains a ceaseless demand for oxygen and nutrients from two vascular networks. The BRB orchestrates the exchange of molecules and fluids within this specialized region, comprising the inner BRB (iBRB) and the outer BRB (oBRB). Extracellular vesicles (EVs) are small membranous structures, and act as messengers facilitating intercellular communication in this milieu.EVs, both from retinal and peripheral immune cells, increase complexity to BRB dysfunction in DR and AMD. Laden with bioactive cargoes, these EVs can modulate the retinal microenvironment, influencing disease progression. Our review delves into the multifaceted role of EVs in retinal degenerative diseases, elucidating the molecular crosstalk they orchestrate, and their microRNA (miRNA) content. By shedding light on these nanoscale messengers, from their biogenesis, release, to interaction and uptake by target cells, we aim to deepen the comprehension of BRB dysfunction and explore their therapeutic potential, therefore increasing our understanding of DR and AMD pathophysiology.
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Affiliation(s)
- Beatriz Martins
- University Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, 3000- 548, Portugal
- University of Coimbra, Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, Coimbra, 3000-548, Portugal
- University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, 3004-531, Portugal
| | - Maria Pires
- University Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, 3000- 548, Portugal
- University of Coimbra, Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, Coimbra, 3000-548, Portugal
- University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, 3004-531, Portugal
| | - António Francisco Ambrósio
- University Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, 3000- 548, Portugal
- University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, 3004-531, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, 3004-561, Portugal
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548, Portugal
| | - Henrique Girão
- University Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, 3000- 548, Portugal
- University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, 3004-531, Portugal
- Clinical Academic Center of Coimbra (CACC), Coimbra, 3004-561, Portugal
| | - Rosa Fernandes
- University Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, 3000- 548, Portugal.
- University of Coimbra, Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, Coimbra, 3000-548, Portugal.
- University of Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, 3004-531, Portugal.
- Clinical Academic Center of Coimbra (CACC), Coimbra, 3004-561, Portugal.
- Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, 3000-548, Portugal.
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Goh KL, Wintergerst MWM, Abbott CJ, Hadoux X, Jannaud M, Kumar H, Hodgson LAB, Guzman G, Janzen S, van Wijngaarden P, Finger RP, Guymer RH, Wu Z. HYPERREFLECTIVE FOCI NOT SEEN AS HYPERPIGMENTARY ABNORMALITIES ON COLOR FUNDUS PHOTOGRAPHS IN AGE-RELATED MACULAR DEGENERATION. Retina 2024; 44:214-221. [PMID: 37831941 DOI: 10.1097/iae.0000000000003958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
PURPOSE To investigate the prognostic value of quantifying optical coherence tomography (OCT)-defined hyperreflective foci (HRF) that do not correspond to hyperpigmentary abnormalities (HPAs) on color fundus photographs (CFPs)-HRF (OCT+/CFP-) -when considered in addition to HPA extent, for predicting late age-related macular degeneration development. This study sought to understand the impact of HRF (OCT+/CFP-) extent on visual sensitivity. METHODS Two hundred eighty eyes from 140 participants with bilateral large drusen underwent imaging and microperimetry at baseline, and then 6-monthly for 3-years. The extent of HPAs on CFPs and HRF (OCT+/CFP-) on OCT was quantified at baseline. Predictive models for progression to late age-related macular degeneration, accounting for drusen volume and age, were developed using HPA extent, with and without HRF (OCT+/CFP-) extent. The association between HPA and HRF (OCT+/CFP-) extent with sector-based visual sensitivity was also evaluated. RESULTS Incorporating HRF (OCT+/CFP-) extent did not improve the predictive performance for late age-related macular degeneration development ( P ≥ 0.32). Increasing HPA and HRF (OCT+/CFP-) extent in each sector were independently and significantly associated with reduced sector-based visual sensitivity ( P ≤ 0.004). CONCLUSION The addition of HRF (OCT+/CFP-) extent to HPA extent did not improve the prediction of late age-related macular degeneration development. HRF (OCT+/CFP-) extent was also independently associated with local reductions in visual sensitivity, after accounting for HPAs.
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Affiliation(s)
- Kai Lyn Goh
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
| | | | - Carla J Abbott
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
| | - Maxime Jannaud
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Himeesh Kumar
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
| | - Lauren A B Hodgson
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
| | - Gabriela Guzman
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Simon Janzen
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Peter van Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
| | - Robert P Finger
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
| | - Zhichao Wu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia; and
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Wang Y, Li H, He Q, Zou R, Cai J, Zhang L. Ferroptosis: underlying mechanisms and involvement in neurodegenerative diseases. Apoptosis 2024; 29:3-21. [PMID: 37848673 DOI: 10.1007/s10495-023-01902-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2023] [Indexed: 10/19/2023]
Abstract
Ferroptosis, a mode of cell death that was recently identified in 2012, is driven by iron-dependent lipid peroxidation and distinct from other mechanisms of cell death such as autophagy and apoptosis. Ferroptosis has the unique features of disruptions in iron equilibrium, iron-induced lipid peroxidation, and the accumulation of glutamate-induced cellular toxicity. The regulation of ferroptosis mainly involves the iron, lipid, and amino acid metabolic pathways, which are controlled by system Xc-, voltage-dependent anion channels, p53 and other pathways. Neurodegenerative diseases involve gradual neuronal loss predominantly within the central nervous system and are categorized into both sporadic and rare hereditary disorders. These diseases result in the progressive decline of specific neuron populations and their interconnections. Recent investigations have revealed a strong correlation between the manifestation and progression of neurodegenerative diseases and ferroptosis. The pharmacological modulation of ferroptosis, whether by induction or inhibition, exhibits promising prospects for therapeutic interventions for these diseases. This review aims to examine the literature on ferroptosis and its implications in various neurodegenerative diseases. We hope to offer novel insights into the potential therapies targeting ferroptosis in central nervous system neurodegenerative diseases. However, there are still limitations of this review. First, despite our efforts to maintain objectivity during our analysis, this review does not cover all the studies on ferroptosis and neurodegenerative diseases. Second, cell death in neurodegenerative diseases is not solely caused by ferroptosis. Future research should focus on the interplay of different cell death mechanisms to better elucidate the specific disease pathogenesis.
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Affiliation(s)
- Yi Wang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - HongJing Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - QianXiong He
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Rong Zou
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - JinRui Cai
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China
| | - Lin Zhang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, Sichuan, China.
- Key Laboratory of Tibetan Medicine Research, Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences, Northwest Institute of Plateau Biology, Xining, 810008, Qinghai, China.
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Shelton DA, Gefke I, Summers V, Kim YK, Yu H, Getz Y, Ferdous S, Donaldson K, Liao K, Papania JT, Chrenek MA, Boatright JH, Nickerson JM. Age-Related RPE changes in Wildtype C57BL/6J Mice between 2 and 32 Months. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.30.574142. [PMID: 38352604 PMCID: PMC10862734 DOI: 10.1101/2024.01.30.574142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Purpose This study provides a systematic evaluation of age-related changes in RPE cell structure and function using a morphometric approach. We aim to better capture nuanced predictive changes in cell heterogeneity that reflect loss of RPE integrity during normal aging. Using C57BL6/J mice ranging from P60-P730, we sought to evaluate how regional changes in RPE shape reflect incremental losses in RPE cell function with advancing age. We hypothesize that tracking global morphological changes in RPE is predictive of functional defects over time. Methods We tested three groups of C57BL/6J mice (young: P60-180; Middle-aged: P365-729; aged: 730+) for function and structural defects using electroretinograms, immunofluorescence, and phagocytosis assays. Results The largest changes in RPE morphology were evident between the young and aged groups, while the middle-aged group exhibited smaller but notable region-specific differences. We observed a 1.9-fold increase in cytoplasmic alpha-catenin expression specifically in the central-medial region of the eye between the young and aged group. There was an 8-fold increase in subretinal, IBA-1-positive immune cell recruitment and a significant decrease in visual function in aged mice compared to young mice. Functional defects in the RPE corroborated by changes in RPE phagocytotic capacity. Conclusions The marked increase of cytoplasmic alpha-catenin expression and subretinal immune cell deposition, and decreased visual output coincide with regional changes in RPE cell morphometrics when stratified by age. These cumulative changes in the RPE morphology showed predictive regional patterns of stress associated with loss of RPE integrity.
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Affiliation(s)
- Debresha A. Shelton
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Isabelle Gefke
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Vivian Summers
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Yong-Kyu Kim
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Department of Ophthalmology, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul, South Korea
| | - Hanyi Yu
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Department of Computer Science, Emory University, Atlanta, Georgia, United States
| | - Yana Getz
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Salma Ferdous
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, United States
| | - Kevin Donaldson
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Kristie Liao
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Jack T. Papania
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
| | - John M. Nickerson
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
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Karg MM, Moorefield M, Hoffmann E, Philipose H, Krasniqi D, Hoppe C, Shu DY, Shirahama S, Ksander BR, Saint-Geniez M. Microglia preserve visual function loss in the aging retina by supporting retinal pigment epithelial health. Immun Ageing 2023; 20:53. [PMID: 37838654 PMCID: PMC10576380 DOI: 10.1186/s12979-023-00358-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 06/23/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Increased age is a risk factor for the development and progression of retinal diseases including age-related macular degeneration (AMD). Understanding the changes that occur in the eye due to aging is important in enhancing our understanding of AMD pathogenesis and the development of novel AMD therapies. Microglia, the resident brain and retinal immune cells are associated with both maintaining homeostasis and protection of neurons and loss of microglia homeostasis could be a significant player in age related neurodegeneration. One important characteristic of retinal aging is the migration of microglia from the inner to outer retina where they reside in the subretinal space (SRS) in contact with the retinal pigment epithelial (RPE) cells. The role of aged subretinal microglia is unknown. Here, we depleted microglia in aged C57/BL6 mice fed for 6 weeks with a chow containing PLX5622, a small molecule inhibitor of colony-stimulating factor-1 receptor (Csf1r) required for microglial survival. RESULTS The subretinal P2RY12 + microglia in aged mice displayed a highly amoeboid and activated morphology and were filled with autofluorescence droplets reminiscent of lipofuscin. TEM indicates that subretinal microglia actively phagocytize shed photoreceptor outer segments, one of the main functions of retinal pigmented epithelial cells. PLX5622 treatment depleted up to 90% of the retinal microglia and was associated with significant loss in visual function. Mice on the microglia depletion diet showed reduced contrast sensitivity and significantly lower electroretinogram for the c-wave, a measurement of RPE functionality, compared to age-matched controls. The loss of c-wave coincided with a loss of RPE cells and increased RPE swelling in the absence of microglia. CONCLUSIONS We conclude that microglia preserve visual function in aged mice and support RPE cell function, by phagocytosing shed photoreceptor outer segments and lipids, therefore compensating for the known age-related decline of RPE phagocytosis.
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Affiliation(s)
- Margarete M Karg
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - May Moorefield
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Emma Hoffmann
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Hannah Philipose
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Drenushe Krasniqi
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
| | - Cindy Hoppe
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Daisy Y Shu
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Shintaro Shirahama
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Bruce R Ksander
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
| | - Magali Saint-Geniez
- Schepens Eye Research Institute of Mass Eye and Ear, 20 Staniford St, Boston, MA, 02114, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
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Yuksel S, Aredo B, Zegeye Y, Zhao CX, Tang M, Li X, Hulleman JD, Gautron L, Ludwig S, Moresco EMY, Butovich IA, Beutler BA, Ufret-Vincenty RL. Forward genetic screening using fundus spot scale identifies an essential role for Lipe in murine retinal homeostasis. Commun Biol 2023; 6:533. [PMID: 37198396 DOI: 10.1038/s42003-023-04870-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 04/24/2023] [Indexed: 05/19/2023] Open
Abstract
Microglia play a role in the pathogenesis of many retinal diseases. Fundus spots in mice often correlate with the accumulation of activated subretinal microglia. Here we use a semiquantitative fundus spot scoring scale in combination with an unbiased, state-of-the-science forward genetics pipeline to identify causative associations between chemically induced mutations and fundus spot phenotypes. Among several associations, we focus on a missense mutation in Lipe linked to an increase in yellow fundus spots in C57BL/6J mice. Lipe-/- mice generated using CRISPR-Cas9 technology are found to develop accumulation of subretinal microglia, a retinal degeneration with decreased visual function, and an abnormal retinal lipid profile. We establish an indispensable role of Lipe in retinal/RPE lipid homeostasis and retinal health. Further studies using this new model will be aimed at determining how lipid dysregulation results in the activation of subretinal microglia and whether these microglia also play a role in the subsequent retinal degeneration.
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Affiliation(s)
- Seher Yuksel
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Bogale Aredo
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Yeshumenesh Zegeye
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Cynthia X Zhao
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Miao Tang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaohong Li
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - John D Hulleman
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Laurent Gautron
- Center for Hypothalamic Research and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sara Ludwig
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eva M Y Moresco
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Igor A Butovich
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Bruce A Beutler
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Lin FL, Cheng YW, Chen LH, Ho JD, Yen JL, Wang MH, Lee TH, Hsiao G. Retinal protection by fungal product theissenolactone B in a sodium iodate-induced AMD model through targeting retinal pigment epithelial matrix metalloproteinase-9 and microglia activity. Biomed Pharmacother 2023; 158:114138. [PMID: 36535199 DOI: 10.1016/j.biopha.2022.114138] [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: 10/30/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of low vision and blindness for which there is currently no cure. Increased matrix metalloproteinase-9 (MMP-9) was found in AMD and potently contributes to its pathogenesis. Resident microglia also promote the processes of chronic neuroinflammation, accelerating the progression of AMD. The present study investigates the effects and mechanisms of the natural compound theissenolactone B (LB53), isolated from Theissenia cinerea, on the effects of RPE dysregulation and microglia hyperactivation and its retinal protective ability in a sodium iodate (NaIO3)-induced retinal degeneration model of AMD. The fungal component LB53 significantly reduces MMP-9 gelatinolysis in TNF-α-stimulated human RPE cells (ARPE-19). Similarly, LB53 abolishes MMP-9 protein and mRNA expression in ARPE-19 cells. Moreover, LB53 efficiently suppresses nitric oxide (NO) production, iNOS expression, and intracellular ROS levels in LPS-stimulated TLR 4-activated microglial BV-2 cells. According to signaling studies, LB53 specifically targets canonical NF-κB signaling in both ARPE-19 and BV-2 microglia. In an RPE-BV-2 interaction assay, LB53 ameliorates LPS-activated BV-2 conditioned medium-induced MMP-9 activation and expression in the RPE. In NaIO3-induced AMD mouse model, LB53 restores photoreceptor and bipolar cell dysfunction as assessed by electroretinography (ERG). Additionally, LB53 prevents retinal thinning, primarily the photoreceptor, and reduces retinal blood flow from NaIO3 damage evaluated by optic coherence tomography (OCT) and laser speckle flowgraphy (LSFG), respectively. Our results demonstrate that LB53 exerts neuroprotection in a mouse model of AMD, which can be attributed to its anti-retinal inflammatory effects by impeding RPE-mediated MMP-9 activation and anti-microglia.
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Affiliation(s)
- Fan-Li Lin
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yu-Wen Cheng
- School of Pharmacy, College of Pharmacy, Taipei Medical University, Taipei, Taiwan
| | - Li-Huei Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jau-Der Ho
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei, Taiwan
| | - Jing-Lun Yen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Mong-Heng Wang
- Department of Physiology, Augusta University, Augusta, GA, USA
| | - Tzong-Huei Lee
- Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan
| | - George Hsiao
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Ph.D. Program for the Clinical Drug Discovery from Botanical Herbs, College of Pharmacy, Taipei Medical University, Taipei, Taiwan.
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8
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Yang X, Diaz V, Huang H. The Role of Interferon Regulatory Factor 1 in Regulating Microglial Activation and Retinal Inflammation. Int J Mol Sci 2022; 23:14664. [PMID: 36498991 PMCID: PMC9739975 DOI: 10.3390/ijms232314664] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Microglia are resident immune cells in the central nervous system (CNS). Microglial activation plays a prominent role in neuroinflammation and CNS diseases. However, the underlying mechanisms of microglial activation are not well understood. Here, we report that the transcription factor interferon regulatory factor 1 (IRF1) plays critical roles in microglial activation and retinal inflammation by regulating pro- and anti-inflammatory gene expression. IRF1 expression was upregulated in activated retinal microglia compared to those at the steady state. IRF1 knockout (KO) in BV2 microglia cells (BV2ΔIRF1) created by CRISPR/Cas9 genome-editing technique causes decreased microglia proliferation, migration, and phagocytosis. IRF1-KO decreased pro-inflammatory M1 marker gene expression induced by lipopolysaccharides (LPS), such as IL-6, COX-2, and CCL5, but increased anti-inflammatory M2 marker gene expression by IL-4/13, such as Arg-1, CD206, and TGF-β. Compared to the wild-type cells, microglial-conditioned media (MCM) of activated BV2ΔIRF1 cell cultures reduced toxicity or death to several retinal cells, including mouse cone photoreceptor-like 661 W cells, rat retinal neuron precursor R28 cells, and human ARPE-19 cells. IRF1 knockdown by siRNA alleviated microglial activation and retinal inflammation induced by LPS in mice. Together, the findings suggest that IRF1 plays a vital role in regulating microglial activation and retinal inflammation and, therefore, may be targeted for treating inflammatory and degenerative retinal diseases.
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Affiliation(s)
- Xu Yang
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
- Aier Eye Hospital Group, Aier Eye Institute, Changsha 410015, China
| | - Valeria Diaz
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Hu Huang
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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Tabel M, Wolf A, Szczepan M, Xu H, Jägle H, Moehle C, Chen M, Langmann T. Genetic targeting or pharmacological inhibition of galectin-3 dampens microglia reactivity and delays retinal degeneration. J Neuroinflammation 2022; 19:229. [PMID: 36115971 PMCID: PMC9482176 DOI: 10.1186/s12974-022-02589-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 09/07/2022] [Indexed: 11/15/2022] Open
Abstract
Background Dysfunctional humoral and cellular innate immunity are key components in the development and progression of age-related macular degeneration (AMD). Specifically, chronically activated microglia and their disturbed regulatory system contribute to retinal degeneration. Galectin-3, a β-galactose binding protein, is a potent driver of macrophage and microglia activation and has been implicated in neuroinflammation, including neurodegenerative diseases of the brain. Here, we hypothesized that genetic deficiency of galectin-3 or its modulation via TD139 dampens mononuclear phagocyte reactivity and delays retinal degeneration. Methods Galectin-3 expression in AMD patients was analyzed by immunohistochemical stainings. Galectin-3 knockout and BALB/cJ mice were exposed to white bright light with an intensity of 15,000 lux for 1 h and Cx3cr1GFP/+ mice to focal blue light of 50,000 lux for 10 min. BALB/cJ and Cx3cr1GFP/+ mice received intraperitoneal injections of 15 mg/kg TD139 or vehicle for five consecutive days, starting one day prior to light exposure. The effects of galectin-3 deficiency or inhibition on microglia were analyzed by immunohistochemical stainings and in situ hybridization of retinal sections and flat mounts. Pro-inflammatory cytokine levels in the retina and retinal pigment epithelium (RPE) were quantified by qRT-PCR and transcriptomic changes were analyzed by RNA-sequencing. Retinal thickness and structure were evaluated by optical coherence tomography. Results We found that galectin-3 expression was strongly upregulated in reactive retinal mononuclear phagocytes of AMD patients and in the two related mouse models of light-induced retinal degeneration. The experimental in vivo data further showed that specific targeting of galectin-3 by genetic knockout or administration of the small-molecule inhibitor TD139 reduced microglia reactivity and delayed retinal damage in both light damage conditions. Conclusion This study defines galectin-3 as a potent driver of retinal degeneration and highlights the protein as a drug target for ocular immunomodulatory therapies. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02589-6.
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10
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Navneet S, Rohrer B. Elastin turnover in ocular diseases: A special focus on age-related macular degeneration. Exp Eye Res 2022; 222:109164. [PMID: 35798060 PMCID: PMC9795808 DOI: 10.1016/j.exer.2022.109164] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/08/2022] [Accepted: 06/20/2022] [Indexed: 12/30/2022]
Abstract
The extracellular matrix (ECM) and its turnover play a crucial role in the pathogenesis of several inflammatory diseases, including age-related macular degeneration (AMD). Elastin, a critical protein component of the ECM, not only provides structural and mechanical support to tissues, but also mediates several intracellular and extracellular molecular signaling pathways. Abnormal turnover of elastin has pathological implications. In the eye elastin is a major structural component of Bruch's membrane (BrM), a critical ECM structure separating the retinal pigment epithelium (RPE) from the choriocapillaris. Reduced integrity of macular BrM elastin, increased serum levels of elastin-derived peptides (EDPs), and elevated elastin antibodies have been reported in AMD. Existing reports suggest that elastases, the elastin-degrading enzymes secreted by RPE, infiltrating macrophages or neutrophils could be involved in BrM elastin degradation, thus contributing to AMD pathogenesis. EDPs derived from elastin degradation can increase inflammatory and angiogenic responses in tissues, and the elastin antibodies are shown to play roles in immune cell activity and complement activation. This review summarizes our current understanding on the elastases/elastin fragments-mediated mechanisms of AMD pathogenesis.
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Affiliation(s)
- Soumya Navneet
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA.
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Division of Research, Charleston, SC, USA.
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11
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van Romunde SHM, Vergouwen DPC, Iacovello D, Roelen DL, Verdijk RM, Ten Berge JCEM, Pertile G, Schreurs MWJ, van Meurs JC. Destructive inflammatory reaction after an autologous retinal pigment epithelium and choroid transplantation: no detection of an auto-immune response. J Ophthalmic Inflamm Infect 2022; 12:27. [PMID: 36018390 PMCID: PMC9418395 DOI: 10.1186/s12348-022-00305-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 08/11/2022] [Indexed: 11/21/2022] Open
Abstract
Purpose Five patients who underwent uncomplicated retinal pigment epithelium (RPE)-choroid transplantation for neovascular age-related macular degeneration developed a destructive inflammatory reaction causing subretinal fluid accumulation and extensive RPE atrophy in the graft. We hypothesized that this inflammation could be caused by an auto-immune response against the graft, resulting in circulating auto-antibodies. The aim of our study was to examine a potential autoimmune origin, which would allow a more targeted therapy approach. Methods Five above-mentioned patients and four control groups of five patients each were included: 1) after uncomplicated RPE-choroid transplantation, 2) after full macular translocation, 3) treated with anti-vascular endothelial growth factor, and 4) healthy controls. Histopathology of rejected graft tissue was performed using standard procedures. Presence of RPE-choroid autoantibodies in serum was examined by indirect immunofluorescence and Western blot, and human leukocyte antigen (HLA) typing was performed. Results Histopathological examination of an explanted graft showed infiltration of T-lymphocytes and macrophages in the choroid and RPE, and an increased number of B-cell lymphocytes were found in the choroid. Indirect immunofluorescence showed weak RPE-choroid autoantibody immunoreactivity in three patients of different groups. Western blot did not show specific RPE-choroid autoantibody immunoreactivity and no difference of HLA genotypes between the groups was found. Conclusions Although local mononuclear inflammatory cell infiltration and a high number of B-lymphocytes were observed in an explanted graft, we did not detect serological evidence of an autoimmune origin of the postoperative inflammation using direct immunofluorescence and Western Blot. Alternatively, the graft failure may have been caused by local innate inflammation, triggered by breakdown of tolerance. Based on our current findings of this small study group, we have no rationale to pursue therapies targeted towards autoreactive graft failure. More research is needed to confirm our findings. Supplementary Information The online version contains supplementary material available at 10.1186/s12348-022-00305-2.
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Affiliation(s)
- Saskia H M van Romunde
- Department of Vitreoretinal surgery, Rotterdam Eye Hospital, Schiedamse Vest 180 - 3011BH, Rotterdam, the Netherlands.
| | - Daphne P C Vergouwen
- Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands.,Department of Immunology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands
| | - Daniela Iacovello
- Department of Ophthalmology, IRCCS Sacro Cuore Don Calabria, Viale Rizzardi, 437024, Negrar, Italy
| | - Dave L Roelen
- Department of Immunology, Leiden Universitary Medical Center, Albinusdreef 2, 2333, ZA, Leiden, the Netherlands
| | - Robert M Verdijk
- Department of Vitreoretinal surgery, Rotterdam Eye Hospital, Schiedamse Vest 180 - 3011BH, Rotterdam, the Netherlands.,Department of Pathology, Section Ophthalmic Pathology, Erasmus MC, University Medical Center, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands.,Department of Pathology, Leiden Universitary Medical Center, Albinusdreef 2, 2333, ZA, Leiden, the Netherlands
| | - Josianne C E M Ten Berge
- Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands
| | - Grazia Pertile
- Department of Ophthalmology, IRCCS Sacro Cuore Don Calabria, Viale Rizzardi, 437024, Negrar, Italy
| | - Marco W J Schreurs
- Department of Immunology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands
| | - Jan C van Meurs
- Department of Vitreoretinal surgery, Rotterdam Eye Hospital, Schiedamse Vest 180 - 3011BH, Rotterdam, the Netherlands.,Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam, Doctor Molewaterplein 40, 3015, GD, Rotterdam, the Netherlands
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12
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Tolentino MJ, Tolentino AJ. Investigational drugs in clinical trials for macular degeneration. Expert Opin Investig Drugs 2022; 31:1067-1085. [PMID: 35962560 DOI: 10.1080/13543784.2022.2113375] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Intravitreal anti-vascular endothelial growth factor (VEGF) injections for exudative age-related macular degeneration (eAMD) are effective and safe but require frequent injections and have nonresponding patients. Geographic atrophy/dry AMD (gaAMD) remains an unmet medical need . New therapies are needed to address this leading cause of blindness in the increasing aged population. AREAS COVERED This paper reviews the pathogenesis of macular degeneration, current and failed therapeutics, therapies undergoing clinical trials and a rationale for why certain AMD therapies may succeed or fail . EXPERT OPINION VEGF- inhibitors reduce both vascular leakage and neovascularization. Experimental therapies that only address neovascularization or leakage will unlikely supplant anti-VEGF therapies. The most promising future therapies for eAMD, are those that target, more potently inhibit and have a more sustained effect on the VEGF pathway such as KSI-301, RGX-314, CLS-AX, EYEP-1901, OTX-TKI. GaAMD is a phenotype of phagocytic retinal cell loss. Inhibiting phagocytic activity of retinal microglial/macrophages at the border of GA and reducing complement derived activators of microglial/macrophage is the most promising strategy. Complement inhibitors (Pegcetacoplan and Avacincaptad pegol) will likely obtain FDA approval but will serve to pave the way for combined complement and direct phagocytic inhibitors such as AVD-104.
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Affiliation(s)
- Michael J Tolentino
- University of Central Florida, FL, USA.,Blue Ocean Clinical Research, Lakeland, FL, USA.,Aviceda Therapeutics, Cambridge, MA, USA
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13
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Zinc transport from the endoplasmic reticulum to the cytoplasm via Zip7 is necessary for barrier dysfunction mediated by inflammatory signaling in RPE cells. PLoS One 2022; 17:e0271656. [PMID: 35901031 PMCID: PMC9333247 DOI: 10.1371/journal.pone.0271656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 07/05/2022] [Indexed: 11/19/2022] Open
Abstract
Inflammatory signaling induces barrier dysfunction in retinal-pigmented epithelium (RPE) cells and plays a role in the pathology of age-related macular degeneration (AMD). We studied the role of Zn flux from the endoplasmic reticulum (ER) to the cytoplasm via Zip7 during inflammatory signaling in RPE cells. In ARPE-19 cells, Zip7 inhibition reduced impedance loss, FITC-dextran permeability and cytokine induction caused by challenge with IL-1β/TNF-α. Zip7 inhibition in iPS-derived RPE cells challenged with TNF- α reduced barrier loss in TER assays. In ARPE-19 cells, a Zn ionophore restored cytokine induction and barrier loss in cells challenged with IL-1 β /TNF- α despite Zip7 inhibition. A cell permeable Zn chelator demonstrated that Zn is essential for IL-1 β /TNF- α signaling. ER stress caused by Zip7 inhibition in ARPE-19 cells was found to partially contribute to reducing barrier dysfunction caused by IL-1 β /TNF- α. Overall, it was shown that Zn flux through Zip7 from the ER to the cytoplasm plays a critical role in driving barrier dysfunction caused by inflammatory cytokines in RPE cells.
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14
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Tang L, Luo D, Qiu Q, Xu GT, Zhang J. Hyperreflective Foci in Diabetic Macular Edema with Subretinal Fluid: Association with Visual Outcomes after Anti-VEGF Treatment. Ophthalmic Res 2022; 66:39-47. [PMID: 35697006 DOI: 10.1159/000525412] [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: 03/25/2022] [Accepted: 05/17/2022] [Indexed: 11/19/2022]
Abstract
INTRODUCTION Objectives of the study were to describe the hyperreflective foci (HRF) on optical coherence tomography angiography in diabetic macular edema (DME) with subretinal fluid (SRF) and explore the association of HRF in the outer retina with photoreceptor integrity and visual outcomes after anti-vascular endothelial growth factor (anti-VEGF) treatment. METHODS We retrospectively reviewed 46 eyes (36 patients) with DME treated with anti-VEGF drugs. The following parameters, including best-corrected visual acuity (BCVA), central macular thickness (CMT), the height of SRF, the number of HRF in the superficial capillary plexus, deep capillary plexus, and the outer retina, as well as the integrity of external limiting membrane (ELM) and ellipsoid zone (EZ), were evaluated and compared between the baseline and after 2 monthly injections of anti-VEGF drugs. The relationship between the HRF in the outer retina and the integrity of ELM and EZ, as well as BCVA, was analyzed. RESULTS BCVA was significantly improved in DME after anti-VEGF treatment; however, for the subgroup of DME patients with SRF, visual acuity remained unchanged after anti-VEGF treatment (p < 0.05 vs. p = 0.375). The number of HRF (p < 0.05), CMT (p < 0.001), and SRF height (p < 0.001) were significantly reduced, accompanied with partial restoration of ELM and EZ integrity after anti-VEGF injection. The HRF in the outer retina was correlated with the final ELM (p = 0.036) and EZ (p = 0.004) status. The final BCVA was significantly better in eyes with intact ELM (p = 0.002) and EZ at final visit (p < 0.001). CONCLUSION The number of HRF in outer retina was negatively associated with the microstructural restoration of ELM and EZ, as well as the visual outcome in DME patients with SRF after anti-VEGF treatment.
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Affiliation(s)
- Lei Tang
- Department of Ophthalmology of Tongji Hospital and Laboratory of Clinical and Visual Sciences of Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
| | - Dawei Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Qinghua Qiu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
- Department of Ophthalmology, Shigatse People's Hospital, Xizang, China
| | - Guo-Tong Xu
- Department of Ophthalmology of Tongji Hospital and Laboratory of Clinical and Visual Sciences of Tongji Eye Institute, Tongji University School of Medicine, Shanghai, China
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China
- National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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15
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Nashine S, Cohen P, Wan J, Kenney C. Effect of Humanin G (HNG) on inflammation in age-related macular degeneration (AMD). Aging (Albany NY) 2022; 14:4247-4269. [PMID: 35576057 PMCID: PMC9186758 DOI: 10.18632/aging.204074] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/25/2022] [Indexed: 12/03/2022]
Abstract
Inflammation plays a crucial role in the etiology and pathogenesis of AMD (Age-related Macular Degeneration). Humanin G (HNG) is a Mitochondrial Derived Peptide (MDP) that is cytoprotective in AMD and can protect against mitochondrial and cellular stress induced by damaged AMD mitochondria. The goal of this study was to test our hypothesis that inflammation-associated marker protein levels are increased in AMD and treatment with HNG leads to reduction in their protein levels. Humanin protein levels were measured in the plasma of AMD patients and normal subjects using ELISA assay. Humanin G was added to AMD and normal (control) cybrids which had identical nuclei from mitochondria-deficient ARPE-19 cells but differed in mitochondrial DNA (mtDNA) content derived from clinically characterized AMD patients and normal (control) subjects. Cell lysates were extracted from untreated and HNG-treated AMD and normal cybrids, and the Luminex XMAP multiplex assay was used to measure the levels of inflammatory proteins. AMD plasma showed reduced Humanin protein levels, but higher protein levels of inflammation markers compared to control plasma samples. In AMD RPE cybrid cells, Humanin G reduced the CD62E/ E-Selectin, CD62P/ P-Selectin, ICAM-1, TNF-α, MIP-1α, IFN–γ, IL-1β, IL-13, and IL-17A protein levels, thereby suggesting that Humanin G may rescue from mtDNA-mediated inflammation in AMD cybrids. In conclusion, we present novel findings that: A) show reduced Humanin protein levels in AMD plasma vs. normal plasma; B) suggest the role of inflammatory markers in AMD pathogenesis, and C) highlight the positive effects of Humanin G in reducing inflammation in AMD.
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Affiliation(s)
- Sonali Nashine
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA
| | - Pinchas Cohen
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90007, USA
| | - Junxiang Wan
- Davis School of Gerontology, University of Southern California, Los Angeles, CA 90007, USA
| | - Cristina Kenney
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA 92697, USA.,Department of Pathology and Laboratory Medicine, University of California, Irvine, CA 92697, USA
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16
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Choi S, Hill D, Guo L, Nicholas R, Papadopoulos D, Cordeiro MF. Automated characterisation of microglia in ageing mice using image processing and supervised machine learning algorithms. Sci Rep 2022; 12:1806. [PMID: 35110632 PMCID: PMC8810899 DOI: 10.1038/s41598-022-05815-6] [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: 09/07/2021] [Accepted: 01/07/2022] [Indexed: 01/12/2023] Open
Abstract
The resident macrophages of the central nervous system, microglia, are becoming increasingly implicated as active participants in neuropathology and ageing. Their diverse and changeable morphology is tightly linked with functions they perform, enabling assessment of their activity through image analysis. To better understand the contributions of microglia in health, senescence, and disease, it is necessary to measure morphology with both speed and reliability. A machine learning approach was developed to facilitate automatic classification of images of retinal microglial cells as one of five morphotypes, using a support vector machine (SVM). The area under the receiver operating characteristic curve for this SVM was between 0.99 and 1, indicating strong performance. The densities of the different microglial morphologies were automatically assessed (using the SVM) within wholemount retinal images. Retinas used in the study were sourced from 28 healthy C57/BL6 mice split over three age points (2, 6, and 28-months). The prevalence of 'activated' microglial morphology was significantly higher at 6- and 28-months compared to 2-months (p < .05 and p < .01 respectively), and 'rod' significantly higher at 6-months than 28-months (p < 0.01). The results of the present study propose a robust cell classification SVM, and further evidence of the dynamic role microglia play in ageing.
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Affiliation(s)
- Soyoung Choi
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
| | - Daniel Hill
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
| | - Li Guo
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
| | - Richard Nicholas
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
- Division of Brain Sciences, Department of Medicine, Imperial College, London, UK
- Population Data Science, Swansea University Medical School, Swansea, SA2 8PP, UK
| | - Dimitrios Papadopoulos
- Laboratory of Molecular Genetics, Hellenic Pasteur Institute, 11521, Athens, Greece
- School of Medicine, European University Cyprus, 2414, Nicosia, Cyprus
| | - Maria Francesca Cordeiro
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK.
- Imperial College Ophthalmology Research Group, Imperial College London, London, UK.
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17
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Coronado BNL, da Cunha FBS, de Oliveira RM, Nóbrega ODT, Ricart CAO, Fontes W, de Sousa MV, de Ávila MP, Martins AMA. Novel Possible Protein Targets in Neovascular Age-Related Macular Degeneration: A Pilot Study Experiment. Front Med (Lausanne) 2022; 8:692272. [PMID: 35155457 PMCID: PMC8828634 DOI: 10.3389/fmed.2021.692272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 12/14/2021] [Indexed: 11/29/2022] Open
Abstract
Age-related macular degeneration (AMD) is among the world's leading causes of blindness. In its neovascular form (nAMD), around 25% of patients present further anatomical and visual deterioration due to persistence of neovascular activity, despite gold-standard treatment protocols using intravitreal anti-VEGF medications. Thus, to comprehend, the molecular pathways that drive choroidal neoangiogenesis, associated with the vascular endothelial growth factor (VEGF), are important steps to elucidate the mechanistic events underneath the disease development. This is a pilot study, a prospective, translational experiment, in a real-life context aiming to evaluate the protein profiles of the aqueous humor of 15 patients divided into three groups: group 1, composed of patients with nAMD, who demonstrated a good response to anti-VEGF intravitreal injections during follow-up (good responsive); group 2, composed of patients with anti-VEGF-resistant nAMD, who demonstrated choroidal neovascularization activity during follow-up (poor/non-responsive); and group 3, composed of control patients without systemic diseases or signs of retinopathy. For proteomic characterization of the groups, mass spectrometry (label-free LC-MS/MS) was used. A total of 2,336 proteins were identified, of which 185 were distinctly regulated and allowed the differentiation of the clinical conditions analyzed. Among those, 39 proteins, including some novel ones, were analyzed as potential disease effectors through their pathophysiological implications in lipid metabolism, oxidative stress, complement system, inflammatory pathways, and angiogenesis. So, this study suggests the participation of other promising biomarkers in neovascular AMD, in addition to the known VEGF.
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Affiliation(s)
- Bruno Nobre Lins Coronado
- Department of Medical Science, Faculty of Medicine, University of Brasilia, Brasilia, Brazil
- Faculty of Medicine, CESMAC University Center, Maceio, Brazil
- *Correspondence: Bruno Nobre Lins Coronado
| | | | - Raphaela Menezes de Oliveira
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil
| | | | - Carlos André Ornelas Ricart
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil
| | - Wagner Fontes
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil
| | - Marcelo Valle de Sousa
- Laboratory of Protein Chemistry and Biochemistry, Department of Cell Biology, Institute of Biological Sciences, University of Brasilia, Brasilia, Brazil
| | | | - Aline Maria Araújo Martins
- Department of Medical Science, Faculty of Medicine, University of Brasilia, Brasilia, Brazil
- Department of Health Science, School of Medicine, University Center of Brasilia (UniCEUB), Brasilia, Brazil
- Aline Maria Araújo Martins
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18
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Strafella C, Caputo V, Termine A, Fabrizio C, Ruffo P, Potenza S, Cusumano A, Ricci F, Caltagirone C, Giardina E, Cascella R. Genetic Determinants Highlight the Existence of Shared Etiopathogenetic Mechanisms Characterizing Age-Related Macular Degeneration and Neurodegenerative Disorders. Front Neurol 2021; 12:626066. [PMID: 34135841 PMCID: PMC8200556 DOI: 10.3389/fneur.2021.626066] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/20/2021] [Indexed: 01/03/2023] Open
Abstract
Age-related macular degeneration (AMD) showed several processes and risk factors in common with neurodegenerative disorders (NDDs). The present work explored the existence of genetic determinants associated with AMD, which may provide insightful clues concerning its relationship with NDDs and their possible application into the clinical practice. In this study, 400 AMD patients were subjected to the genotyping analysis of 120 genetic variants by OpenArray technology. As the reference group, 503 samples representative of the European general population were utilized. Statistical analysis revealed the association of 23 single-nucleotide polymorphisms (SNPs) with AMD risk. The analysis of epistatic effects revealed that ARMS2, IL6, APOE, and IL2RA could contribute to AMD and neurodegenerative processes by synergistic modulation of the expression of disease-relevant genes. In addition, the bioinformatic analysis of the associated miRNA variants highlighted miR-196a, miR-6796, miR-6499, miR-6810, miR-499, and miR-7854 as potential candidates for counteracting AMD and neurodegenerative processes. Finally, this work highlighted the existence of shared disease mechanisms (oxidative stress, immune-inflammatory response, mitochondrial dysfunction, axonal guidance pathway, and synaptogenesis) between AMD and NDDs and described the associated SNPs as candidate biomarkers for developing novel strategies for early diagnosis, monitoring, and treatment of such disorders in a progressive aging population.
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Affiliation(s)
- Claudia Strafella
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy.,Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Valerio Caputo
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy.,Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Andrea Termine
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Carlo Fabrizio
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Paola Ruffo
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Saverio Potenza
- Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Andrea Cusumano
- UOSD of Ophthalmology PTV Foundation "Policlinico Tor Vergata", Rome, Italy
| | - Federico Ricci
- UNIT Retinal Diseases PTV Foundation "Policlinico Tor Vergata", Rome, Italy
| | - Carlo Caltagirone
- Department of Clinical and Behavioral Neurology, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Emiliano Giardina
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy.,Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Raffaella Cascella
- Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy.,Department of Biomedical Sciences, Catholic University Our Lady of Good Counsel, Tirana, Albania
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19
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Histopathology of Age-Related Macular Degeneration and Implications for Pathogenesis and Therapy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 33847998 DOI: 10.1007/978-3-030-66014-7_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
Aging is associated with a number of histological changes in the choroid, Bruch's membrane, RPE, and neuroretina. Outside of the normal physiologic aging spectrum of changes, abnormal deposits such as basal laminar deposits, basal linear deposits, and soft drusen are known to be associated with AMD. Progression of AMD to advanced stages involving geographic atrophy, choroidal neovascularization, and/or disciform scars can result in debilitating vision loss. Knowledge of the angiogenic pathway and its components that stimulate neovascularization has led to the development of a new paradigm of intravitreal anti-VEGF pharmacotherapy in the management of neovascular AMD. Currently however, there are no available treatments for the modification of disease progression in non-neovascular AMD, or for the treatment of geographic atrophy. Further understanding of the histopathology of AMD and the molecular mechanisms that contribute to pathogenesis of the disease may reveal additional therapeutic targets.
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20
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Differential Action of Connexin Hemichannel and Pannexin Channel Therapeutics for Potential Treatment of Retinal Diseases. Int J Mol Sci 2021; 22:ijms22041755. [PMID: 33578721 PMCID: PMC7916454 DOI: 10.3390/ijms22041755] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/02/2021] [Accepted: 02/07/2021] [Indexed: 12/15/2022] Open
Abstract
Dysregulation of retinal function in the early stages of light-induced retinal degeneration involves pannexins and connexins. These two types of proteins may contribute to channels that release ATP, leading to activation of the inflammasome pathway, spread of inflammation and retinal dysfunction. However, the effect of pannexin channel block alone or block of both pannexin channels and connexin hemichannels in parallel on retinal activity in vivo is unknown. In this study, the pannexin channel blocker probenecid and the connexin hemichannel blocker tonabersat were used in the light-damaged rat retina. Retinal function was evaluated using electroretinography (ERG), retinal structure was analyzed using optical coherence tomography (OCT) imaging and the tissue response to light-induced injury was assessed immunohistochemically with antibodies against glial fibrillary acidic protein (GFAP), Ionized calcium binding adaptor molecule 1 (Iba-1) and Connexin43 (Cx43). Probenecid did not further enhance the therapeutic effect of connexin hemichannel block in this model, but on its own improved activity of certain inner retina neurons. The therapeutic benefit of blocking connexin hemichannels was further evaluated by comparing these data against results from our previously published studies that also used the light-damaged rat retina model. The analysis showed that treatment with tonabersat alone was better than probenecid alone at restoring retinal function in the light-damaged retina model. The results assist in the interpretation of the differential action of connexin hemichannel and pannexin channel therapeutics for potential treatment of retinal diseases.
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Soundara Pandi SP, Ratnayaka JA, Lotery AJ, Teeling JL. Progress in developing rodent models of age-related macular degeneration (AMD). Exp Eye Res 2020; 203:108404. [PMID: 33340497 DOI: 10.1016/j.exer.2020.108404] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 12/13/2020] [Accepted: 12/14/2020] [Indexed: 12/25/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss, typically affecting individuals from mid-life onwards. Its multifactorial aetiology and the lack of any effective treatments has spurred the development of animal models as research and drug discovery tools. Several rodent models have been developed which recapitulate key features of AMD and provide insights into its underlying pathology. These have contributed to making significant progress in understanding the disease and the identification of novel therapeutic targets. However, a major caveat with existing models is that they do not demonstrate the full disease spectrum. In this review, we outline advances in rodent AMD models from the last decade. These models feature various hallmarks associated with AMD, including oxidative stress, hypoxia, immune dysregulation, genetic mutations and environmental risk factors. The review summarises the methods by which each model was created, its pathological characteristics as well as its relation to the disease in humans.
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Affiliation(s)
- Sudha Priya Soundara Pandi
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom.
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom; Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, United Kingdom.
| | - Jessica L Teeling
- Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, MP840, Tremona Road, Southampton, SO16 6YD, United Kingdom.
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Silva NJ, Nagashima M, Li J, Kakuk‐Atkins L, Ashrafzadeh M, Hyde DR, Hitchcock PF. Inflammation and matrix metalloproteinase 9 (Mmp-9) regulate photoreceptor regeneration in adult zebrafish. Glia 2020; 68:1445-1465. [PMID: 32034934 PMCID: PMC7317489 DOI: 10.1002/glia.23792] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/24/2019] [Accepted: 01/23/2020] [Indexed: 12/17/2022]
Abstract
Brain injury activates complex inflammatory signals in dying neurons, surviving neurons, and glia. Here, we establish that inflammation regulates the regeneration of photoreceptors in the zebrafish retina and determine the cellular expression and function of the inflammatory protease, matrix metalloproteinase 9 (Mmp-9), during this regenerative neurogenesis. Following photoreceptor ablation, anti-inflammatory treatment suppresses the number of injury-induced progenitors and regenerated photoreceptors. Upon photoreceptor injury, mmp-9 is induced in Müller glia and Müller glia-derived photoreceptor progenitors. Deleting mmp-9 results in over production of injury-induced progenitors and regenerated photoreceptors, but over time the absence of Mmp-9 compromises the survival of the regenerated cones. At all time-points studied, the levels of tnf-α are significantly elevated in mutant retinas. Anti-inflammatory treatment in mutants rescues the defects in cone survival. These data provide a link between injury-induced inflammation in the vertebrate CNS, Mmp-9 function during neuronal regeneration and the requirement of Mmp-9 for the survival of regenerated cones.
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Affiliation(s)
- Nicholas J. Silva
- Neuroscience Graduate ProgramUniversity of MichiganAnn ArborMichigan
- Department of Ophthalmology and Visual SciencesUniversity of MichiganAnn ArborMichigan
| | - Mikiko Nagashima
- Department of Ophthalmology and Visual SciencesUniversity of MichiganAnn ArborMichigan
| | - Jingling Li
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
| | - Laura Kakuk‐Atkins
- Department of Ophthalmology and Visual SciencesUniversity of MichiganAnn ArborMichigan
| | - Milad Ashrafzadeh
- Department of Ophthalmology and Visual SciencesUniversity of MichiganAnn ArborMichigan
| | - David R. Hyde
- Department of Biological SciencesUniversity of Notre DameNotre DameIndiana
| | - Peter F. Hitchcock
- Neuroscience Graduate ProgramUniversity of MichiganAnn ArborMichigan
- Department of Ophthalmology and Visual SciencesUniversity of MichiganAnn ArborMichigan
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Hsia Y, Yang CH, Hsieh YT, Yang CM, Ho TC, Lai TT. Hyperreflective foci in predicting the treatment outcome of antivascular endothelial growth factor in neovascular age-related macular degeneration. Graefes Arch Clin Exp Ophthalmol 2019; 258:273-280. [PMID: 31828425 DOI: 10.1007/s00417-019-04546-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/04/2019] [Accepted: 11/11/2019] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To describe the optical coherence tomographic findings of hyperreflective foci (HF) in neovascular age-related macular degeneration and evaluate the use of HF to predict visual outcome after antivascular endothelium growth factor (anti-VEGF) therapy. METHODS This was a post-hoc analysis of a retrospective cohort study. Hyperreflective foci were localized in the inner retina, outer retina, or subretinal fluid (SRF) layer. The treatment response of HF was recorded. The association between HF and visual outcome was analyzed. RESULTS We enrolled 126 eyes. Hyperreflective foci involving more than one layer were associated with poor initial visual acuity (P < 0.001). Hyperreflective foci in each layer at baseline were negatively correlated with baseline visual acuity. At 3 months posttreatment, HF in the SRF layer had decreased significantly (P = 0.003), which was faster compared with HF in other layers. Baseline HF status at each layer was not associated with final visual outcome. The eyes with reduced HF in the SRF at 3 months had better visual improvement at 12 months (P = 0.038). CONCLUSION Hyperreflective foci involving multiple layers were associated with poor initial visual acuity but not with final visual outcome. With anti-VEGF treatment, HF in the SRF layer resolved faster, which may predict better visual outcome.
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Affiliation(s)
- Yun Hsia
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Ting Hsieh
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan.,Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Tzyy-Chang Ho
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Tso-Ting Lai
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan. .,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
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Chung SH, Shen W, Davidson KC, Pébay A, Wong RCB, Yau B, Gillies M. Differentiation of Retinal Glial Cells From Human Embryonic Stem Cells by Promoting the Notch Signaling Pathway. Front Cell Neurosci 2019; 13:527. [PMID: 31849614 PMCID: PMC6901827 DOI: 10.3389/fncel.2019.00527] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 11/12/2019] [Indexed: 01/21/2023] Open
Abstract
Dysfunction of retinal glial cells, particularly Müller cells, has been implicated in several retinal diseases. Despite their important contribution to retinal homeostasis, a specific way to differentiate retinal glial cells from human pluripotent stem cells has not yet been described. Here, we report a method to differentiate retinal glial cells from human embryonic stem cells (hESCs) through promoting the Notch signaling pathway. We first generated retinal progenitor cells (RPCs) from hESCs then promoted the Notch signaling pathway using Notch ligands, including Delta-like ligand 4 and Jagged-1. We validated glial cell differentiation with qRT-PCR, immunocytochemistry, western blots and fluorescence-activated cell sorting as we promoted Notch signaling in RPCs. We found that promoting Notch signaling in RPCs for 2 weeks led to upregulation of glial cell markers, including glial fibrillary acidic protein (GFAP), glutamine synthetase, vimentin and cellular retinaldehyde-binding protein (CRALBP). Of these markers, we found the greatest increase in expression of the pan glial cell marker, GFAP. Conversely, we also found that inhibition of Notch signaling in RPCs led to upregulation of retinal neuronal markers including cone-rod homeobox (CRX) and orthodenticle homeobox 2 (OTX2) but with little expression of GFAP. This retinal glial differentiation method will help advance the generation of stem cell disease models to study the pathogenesis of retinal diseases associated with glial dysfunction such as macular telangiectasia type 2. This method may also be useful for the development of future therapeutics such as drug screening and gene editing using patient-derived retinal glial cells.
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Affiliation(s)
- Sook Hyun Chung
- Save Sight Institute, Department of Clinical Ophthalmology and Eye Health, The University of Sydney, Sydney, NSW, Australia
| | - Weiyong Shen
- Save Sight Institute, Department of Clinical Ophthalmology and Eye Health, The University of Sydney, Sydney, NSW, Australia
| | - Kathryn C Davidson
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia
| | - Alice Pébay
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia.,Department of Surgery, The University of Melbourne, Parkville, VIC, Australia
| | - Raymond C B Wong
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, VIC, Australia.,Department of Surgery, The University of Melbourne, Parkville, VIC, Australia.,Shenzhen Eye Hospital, Shenzhen, China
| | - Belinda Yau
- Save Sight Institute, Department of Clinical Ophthalmology and Eye Health, The University of Sydney, Sydney, NSW, Australia
| | - Mark Gillies
- Save Sight Institute, Department of Clinical Ophthalmology and Eye Health, The University of Sydney, Sydney, NSW, Australia
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Cunningham F, Van Bergen T, Canning P, Lengyel I, Feyen JHM, Stitt AW. The Placental Growth Factor Pathway and Its Potential Role in Macular Degenerative Disease. Curr Eye Res 2019; 44:813-822. [PMID: 31055948 DOI: 10.1080/02713683.2019.1614197] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
There is growing evidence that placental growth factor (PlGF) is an important player in multiple pathologies, including tumorigenesis, inflammatory disorders and degenerative retinopathies. PlGF is a member of the vascular endothelial growth factor (VEGF) family and in the retina, binding of this growth factor to specific receptors is associated with pathological angiogenesis, vascular leakage, neurodegeneration and inflammation. Although they share some receptor signalling pathways, many of the actions of PlGF are distinct from VEGF and this has revealed the enticing prospect that it could be a useful therapeutic target for treating early and late stages of diabetic retinopathy (DR) and neovascular age-related macular degeneration (AMD). Recent research suggests that modulation of PlGF could also be important in the geographic atrophy (GA) form of late AMD by protecting the outer retina and the retinal pigment epithelium (RPE). This review discusses PlGF and its signalling pathways and highlights the potential of blocking the bioactivity of this growth factor to treat irreversible visual loss due to the two main forms of AMD.
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Affiliation(s)
- Fiona Cunningham
- a Centre for Experimental Medicine, Queen's University Belfast , Belfast , Northern Ireland
| | | | - Paul Canning
- a Centre for Experimental Medicine, Queen's University Belfast , Belfast , Northern Ireland
| | - Imre Lengyel
- a Centre for Experimental Medicine, Queen's University Belfast , Belfast , Northern Ireland
| | | | - Alan W Stitt
- a Centre for Experimental Medicine, Queen's University Belfast , Belfast , Northern Ireland
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Telegina DV, Kozhevnikova OS, Kolosova NG. Changes in Retinal Glial Cells with Age and during Development of Age-Related Macular Degeneration. BIOCHEMISTRY (MOSCOW) 2018; 83:1009-1017. [PMID: 30472939 DOI: 10.1134/s000629791809002x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Age is the major risk factor in the age-related macular degeneration (AMD) which is a complex multifactor neurodegenerative disease of the retina and the main cause of irreversible vision loss in people over 60 years old. The major role in AMD pathogenesis belongs to structure-functional changes in the retinal pigment epithelium cells, while the onset and progression of AMD are commonly believed to be caused by the immune system dysfunctions. The role of retinal glial cells (Muller cells, astrocytes, and microglia) in AMD pathogenesis is studied much less. These cells maintain neurons and retinal vessels through the synthesis of neurotrophic and angiogenic factors, as well as perform supporting, separating, trophic, secretory, and immune functions. It is known that retinal glia experiences morphological and functional changes with age. Age-related impairments in the functional activity of glial cells are closely related to the changes in the expression of trophic factors that affect the status of all cell types in the retina. In this review, we summarized available literature data on the role of retinal macro- and microglia and on the contribution of these cells to AMD pathogenesis.
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Affiliation(s)
- D V Telegina
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - O S Kozhevnikova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - N G Kolosova
- Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
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Sun C, Mitchell DM, Stenkamp DL. Isolation of photoreceptors from mature, developing, and regenerated zebrafish retinas, and of microglia/macrophages from regenerating zebrafish retinas. Exp Eye Res 2018; 177:130-144. [PMID: 30096325 DOI: 10.1016/j.exer.2018.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/30/2018] [Accepted: 08/06/2018] [Indexed: 12/16/2022]
Abstract
This paper describes experimental procedures for the dissociation of retinal cells of the zebrafish (Danio rerio) for subsequent fluorescence-activated cell sorting (FACS) and gene expression studies. Methods for dissociation of zebrafish retinas followed by FACS and RNA isolation were optimized. This methodology was applied to isolate pure sorted samples of rods, long wavelength-sensitive (LWS) cones, medium wavelength-sensitive (MWS; RH2-2) cones, short wavelength-sensitive (SWS2) cones, and UV-sensitive (SWS1) cones from retinas obtained at selective life-history stages of the zebrafish, and for some of these photoreceptors, following retinal regeneration. We also successfully separated lws1-expressing and lws2-expressing LWS cones from fish of a transgenic line in which lws1 is reported with green fluorescence protein (GFP) and lws2 is reported with red fluorescence protein (RFP). Microglia/macrophages were successfully sorted from regenerating retinas (7 days after a cytotoxic lesion) of a transgenic line in which these immune cells express GFP. Electropherograms verified downstream isolation of high-quality RNA from sorted samples. Examples of post-sorting analysis, as well as results of qRT-PCR studies, validated the purity of sorted populations. For example, qRT-PCR samples derived from isolated Rh2-2 cones contained detectable rh2-2 (opn1mw2) opsin transcripts, but lws opsin transcripts (lws1/opn1lw1, lws2/opn1lw2) were not detected, suggesting that the procedure likely separated double cone pairs. Through this method, pure, sorted cell samples can provide RNA that is reliable for downstream gene expression analyses, such as qRT-PCR and RNA-seq, which may reveal molecular signatures of photoreceptors and microglia for comparative transcriptomics studies.
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Affiliation(s)
- Chi Sun
- Department of Biological Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Diana M Mitchell
- Department of Biological Sciences, University of Idaho, Moscow, ID, 83844, USA
| | - Deborah L Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, ID, 83844, USA.
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Ma W, Zhang Y, Gao C, Fariss RN, Tam J, Wong WT. Monocyte infiltration and proliferation reestablish myeloid cell homeostasis in the mouse retina following retinal pigment epithelial cell injury. Sci Rep 2017; 7:8433. [PMID: 28814744 PMCID: PMC5559448 DOI: 10.1038/s41598-017-08702-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/13/2017] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD), a leading contributor of vision loss, currently lacks comprehensive treatment. While AMD histopathology involves retinal pigment epithelium (RPE) injury associated with immune cell infiltration, the nature of immune cell responses to RPE injury remains undefined. We induced RPE injury pharmacologically and genetically in transgenic mouse models in which microglia and systemic monocytes were separately tagged, enabling a spatial and temporal dissection of the relative contributions of microglia vs. monocytes to post-injury changes. We found that myeloid cell responses to RPE injury occur in stages: (1) an early mobilization of endogenous microglia from the inner retina to the RPE layer, followed by (2) subsequent monocyte infiltration from the retinal vasculature into the inner retina that replenishes the local myeloid cell population in a CCR2-regulated manner. These altered distributions of myeloid cells post-injury were long-lived, with recruited monocytes acquiring the distribution, markers, and morphologies of neighboring endogenous microglia in a durable manner. These findings indicate the role played by infiltrating monocytes in maintaining myeloid cell homeostasis in the retina following AMD-relevant RPE injury and provide a foundation for understanding and therapeutically modulating immune aspects in retinal disease.
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Affiliation(s)
- Wenxin Ma
- Unit on Neuron-Glia Interactions in Retinal Disease, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yikui Zhang
- Unit on Neuron-Glia Interactions in Retinal Disease, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Chun Gao
- Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Robert N Fariss
- Biological Imaging Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Johnny Tam
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Wai T Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Institutes of Health, Bethesda, MD, 20892, USA.
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HYPERREFLECTIVE INTRARETINAL SPOTS IN RADIATION MACULAR EDEMA ON SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY. Retina 2016; 36:1664-9. [DOI: 10.1097/iae.0000000000000986] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fox AR, Chew EY, Meyerle C, Vitale S, Ferris FL, Nussenblatt RB, Sen HN. Age-related macular degeneration in patients with uveitis. Br J Ophthalmol 2016; 101:342-347. [PMID: 27154918 DOI: 10.1136/bjophthalmol-2016-308587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/09/2016] [Accepted: 04/14/2016] [Indexed: 11/04/2022]
Abstract
PURPOSE To evaluate the prevalence of large drusen in a uveitis clinic population. DESIGN Retrospective, cohort study. METHODS Patients with primary, non-infectious uveitis 55 years or older who were seen at the National Eye Institute of the National Institutes of Health from 2004 through August 2013 were reviewed using electronic medical records and photographic databases. Patients were classified as having age-related macular degeneration (AMD) if either eye had large drusen, geographic atrophy or neovascular AMD according to definitions used by the Eye Diseases Prevalence Research Group (EDPRG). The expected number of cases and standardised mortality ratio (SMR) for large drusen were estimated based on EDPRG estimates. RESULTS We identified 177 patients aged ≥55 years as having primary non-infectious uveitis; 170 (96.0%) had gradable fundus photos. Average age was 65.0±7.5 years (range 55-87), and 87 were non-Hispanic white, 66 non-Hispanic black, 6 Hispanic white and 11 of other race/ethnicity. Large drusen were identified in four patients (2.4%; 95% CI 0.6 to 6.0). No patients were identified to have late AMD. In the uveitis cohort, the SMR for cases of large drusen, which was adjusted for age, was calculated to be 0.32 (95% CI 0.12 to 0.70) for the whole cohort, 0.28 (95% CI 0.09 to 0.79) for non-Hispanic whites and 0.46 (95% CI 0.14 to 1.29) for non-Hispanic blacks. CONCLUSIONS Large drusen prevalence among patients with uveitis ≥55 years of age appears less than the prevalence in the general US population after accounting for differences in age distribution, especially for non-Hispanic whites. Although the racial and gender distribution in this study population is not directly representative of the general US population, results of this study suggest possible sparing of patients with uveitis from AMD. A larger systematic study with greater power would be needed to confirm these findings.
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Affiliation(s)
- Austin R Fox
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Emily Y Chew
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Catherine Meyerle
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Susan Vitale
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Frederick L Ferris
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | | | - H Nida Sen
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
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31
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Aging Changes in Retinal Microglia and their Relevance to Age-related Retinal Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:73-8. [PMID: 26427396 DOI: 10.1007/978-3-319-17121-0_11] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Age-related retinal diseases, such as age-related macular degeneration (AMD) and glaucoma, contain features of chronic retinal inflammation that may promote disease progression. However, the relationship between aging and neuroinflammation is unclear. Microglia are long-lived, resident immune cells of the retina, and mediate local neuroinflammatory reactions. We hypothesize that aging changes in microglia may be causally linked to neuroinflammatory changes underlying age-dependent retinal diseases. Here, we review the evidence for (1) how the retinal microglial phenotype changes with aging, (2) the factors that drive microglial aging in the retina, and (3) aging-related changes in microglial gene expression. We examine how these aspects of microglial aging changes may relate to pathogenic mechanisms of immune dysregulation driving the progression of age-related retinal disease. These relationships can highlight microglial aging as a novel target for the prevention and treatment of retinal disease.
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Kambhampati SP, Clunies-Ross AJM, Bhutto I, Mishra MK, Edwards M, McLeod DS, Kannan RM, Lutty G. Systemic and Intravitreal Delivery of Dendrimers to Activated Microglia/Macrophage in Ischemia/Reperfusion Mouse Retina. Invest Ophthalmol Vis Sci 2015; 56:4413-24. [PMID: 26193917 DOI: 10.1167/iovs.14-16250] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
PURPOSE Microglial activation and associated neuroinflammation play a key role in the pathogenesis of many diseases of the retina, including viral infection, diabetes, and retinal degeneration. Strategies to target activated microglia and macrophages and attenuate inflammation may be valuable in treating these diseases. We seek to develop dendrimer-based formulations that target retinal microglia and macrophages in a pathology-dependent manner, and deliver drugs, either intravenously or intravitreally. METHODS Retinal uptake of cyanine dye (Cy5)-conjugated dendrimer (D-Cy5) was assessed in normal and ischemia/reperfusion (I/R) mouse eyes. Microglia/macrophage uptake of the dendrimer was assessed with immunofluorescence using rabbit Iba-1 antibody with Cy3-tagged secondary antibody (microglia/macrophage). Uptake in retina and other organs was quantified using fluorescence spectroscopy. RESULTS Clearance of D-Cy5 from normal eyes was almost complete by 72 hours after intravitreal injection and 24 hours after intravenous delivery. In eyes with activated microglia after I/R injury, D-Cy5 was retained by activated microglia/macrophage (Iba1+ cells) up to 21 days after intravitreal and intravenous administration. In I/R eyes, the relative retention of intravitreal and intravenous D-Cy5 was comparable, if a 30-fold higher intravenous dose was used. CONCLUSIONS Intravitreal and systemic dendrimers target activated microglia and show qualitatively similar retinal biodistribution when administered by either route. Results provide proof-of-concept insights for developing dendrimer drug formulations as treatment options for retinal diseases associated with microglia or macrophage activation such as age-related macular degeneration, diabetic retinopathy, and retinal degenerations.
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Affiliation(s)
- Siva P Kambhampati
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States 2Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States
| | - Alexander J M Clunies-Ross
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
| | - Imran Bhutto
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
| | - Manoj K Mishra
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
| | - Malia Edwards
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
| | - D Scott McLeod
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
| | - Rangaramanujam M Kannan
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
| | - Gerard Lutty
- Department of Ophthalmology Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States
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Volz C, Pauly D. Antibody therapies and their challenges in the treatment of age-related macular degeneration. Eur J Pharm Biopharm 2015; 95:158-72. [DOI: 10.1016/j.ejpb.2015.02.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 02/16/2015] [Accepted: 02/20/2015] [Indexed: 12/13/2022]
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Kijlstra A, Berendschot TTJM. Age-related macular degeneration: a complementopathy? Ophthalmic Res 2015; 54:64-73. [PMID: 26159686 DOI: 10.1159/000432401] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 05/16/2015] [Indexed: 11/19/2022]
Abstract
Age-related macular degeneration (AMD) is a progressive eye disease affecting many elderly individuals. It has a multifactorial pathogenesis and is associated with numerous environmental (e.g. smoking, light and nutrition) and genetic risk factors. A breakthrough in the mechanisms causing AMD is emerging; the involvement of the alternative pathway of the complement system appears to play a pivotal role. This has led to the statement that AMD is a disease caused by a hyperactive complement system, allowing the term 'complementopathy' to define it more precisely. Abundant evidence includes: the identification of drusen components as activators of complement, immunohistochemical data showing the presence of many species of the complement system in the retinal pigment epithelium-Bruch's membrane-choroidocapillary region of AMD eyes, a strong association of AMD with certain genetic complement protein variants, raised complement levels in blood from AMD patients and the preliminary successful treatments of geographic atrophy with complement factor D (FD) inhibitors. FD is the rate-limiting enzyme of the alternative complement pathway, and is produced by adipose tissue. Recent findings suggest that nutrition may play a role in controlling the level of FD in the circulation. Addressing modifiable risk factors such as smoking and nutrition may thus offer opportunities for the prevention of AMD.
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Affiliation(s)
- Aize Kijlstra
- University Eye Clinic Maastricht, Maastricht, The Netherlands
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Vecino E, Rodriguez FD, Ruzafa N, Pereiro X, Sharma SC. Glia-neuron interactions in the mammalian retina. Prog Retin Eye Res 2015; 51:1-40. [PMID: 26113209 DOI: 10.1016/j.preteyeres.2015.06.003] [Citation(s) in RCA: 493] [Impact Index Per Article: 54.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/18/2015] [Accepted: 06/02/2015] [Indexed: 02/07/2023]
Abstract
The mammalian retina provides an excellent opportunity to study glia-neuron interactions and the interactions of glia with blood vessels. Three main types of glial cells are found in the mammalian retina that serve to maintain retinal homeostasis: astrocytes, Müller cells and resident microglia. Müller cells, astrocytes and microglia not only provide structural support but they are also involved in metabolism, the phagocytosis of neuronal debris, the release of certain transmitters and trophic factors and K(+) uptake. Astrocytes are mostly located in the nerve fibre layer and they accompany the blood vessels in the inner nuclear layer. Indeed, like Müller cells, astrocytic processes cover the blood vessels forming the retinal blood barrier and they fulfil a significant role in ion homeostasis. Among other activities, microglia can be stimulated to fulfil a macrophage function, as well as to interact with other glial cells and neurons by secreting growth factors. This review summarizes the main functional relationships between retinal glial cells and neurons, presenting a general picture of the retina recently modified based on experimental observations. The preferential involvement of the distinct glia cells in terms of the activity in the retina is discussed, for example, while Müller cells may serve as progenitors of retinal neurons, astrocytes and microglia are responsible for synaptic pruning. Since different types of glia participate together in certain activities in the retina, it is imperative to explore the order of redundancy and to explore the heterogeneity among these cells. Recent studies revealed the association of glia cell heterogeneity with specific functions. Finally, the neuroprotective effects of glia on photoreceptors and ganglion cells under normal and adverse conditions will also be explored.
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Affiliation(s)
- Elena Vecino
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - F David Rodriguez
- Department of Biochemistry and Molecular Biology, E-37007, University of Salamanca, Salamanca, Spain
| | - Noelia Ruzafa
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - Xandra Pereiro
- Department of Cell Biology and Histology, University of the Basque Country UPV/EHU, Leioa 48940, Vizcaya, Spain
| | - Sansar C Sharma
- Department of Ophthalmology, Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10595, USA; IKERBASQUE, Basque Foundation for Science at Dept. Cell Biology and Histology, UPV/EHU, Spain
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Deletion of myosin VI causes slow retinal optic neuropathy and age-related macular degeneration (AMD)-relevant retinal phenotype. Cell Mol Life Sci 2015; 72:3953-69. [PMID: 25939269 PMCID: PMC4575690 DOI: 10.1007/s00018-015-1913-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 04/20/2015] [Accepted: 04/23/2015] [Indexed: 11/16/2022]
Abstract
The unconventional myosin VI, a member of the actin-based motor protein family of myosins, is expressed in the retina. Its deletion was previously shown to reduce amplitudes of the a- and b-waves of the electroretinogram. Analyzing wild-type and myosin VI-deficient Snell’s Waltzer mice in more detail, the expression pattern of myosin VI in retinal pigment epithelium, outer limiting membrane, and outer plexiform layer could be linked with differential progressing ocular deficits. These encompassed reduced a-waves and b-waves and disturbed oscillatory potentials in the electroretinogram, photoreceptor cell death, retinal microglia infiltration, and formation of basal laminar deposits. A phenotype comprising features of glaucoma (neurodegeneration) and age-related macular degeneration could thus be uncovered that suggests dysfunction of myosin VI and its variable cargo adaptor proteins for membrane sorting and autophagy, as possible candidate mediators for both disease forms.
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Karlstetter M, Scholz R, Rutar M, Wong WT, Provis JM, Langmann T. Retinal microglia: just bystander or target for therapy? Prog Retin Eye Res 2014; 45:30-57. [PMID: 25476242 DOI: 10.1016/j.preteyeres.2014.11.004] [Citation(s) in RCA: 368] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 10/24/2022]
Abstract
Resident microglial cells can be regarded as the immunological watchdogs of the brain and the retina. They are active sensors of their neuronal microenvironment and rapidly respond to various insults with a morphological and functional transformation into reactive phagocytes. There is strong evidence from animal models and in situ analyses of human tissue that microglial reactivity is a common hallmark of various retinal degenerative and inflammatory diseases. These include rare hereditary retinopathies such as retinitis pigmentosa and X-linked juvenile retinoschisis but also comprise more common multifactorial retinal diseases such as age-related macular degeneration, diabetic retinopathy, glaucoma, and uveitis as well as neurological disorders with ocular manifestation. In this review, we describe how microglial function is kept in balance under normal conditions by cross-talk with other retinal cells and summarize how microglia respond to different forms of retinal injury. In addition, we present the concept that microglia play a key role in local regulation of complement in the retina and specify aspects of microglial aging relevant for chronic inflammatory processes in the retina. We conclude that this resident immune cell of the retina cannot be simply regarded as bystander of disease but may instead be a potential therapeutic target to be modulated in the treatment of degenerative and inflammatory diseases of the retina.
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Affiliation(s)
- Marcus Karlstetter
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Rebecca Scholz
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Matt Rutar
- The John Curtin School of Medical Research, The Australian National University (ANU), Canberra, Australian Capital Territory, Australia
| | - Wai T Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jan M Provis
- The John Curtin School of Medical Research, The Australian National University (ANU), Canberra, Australian Capital Territory, Australia
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.
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Nussenblatt RB, Lee RW, Chew E, Wei L, Liu B, Sen HN, Dick AD, Ferris FL. Immune responses in age-related macular degeneration and a possible long-term therapeutic strategy for prevention. Am J Ophthalmol 2014; 158:5-11.e2. [PMID: 24709810 DOI: 10.1016/j.ajo.2014.03.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 12/21/2022]
Abstract
PURPOSE To describe the immune alterations associated with age-related macular degeneration (AMD); and, based on these findings, to offer an approach to possibly prevent the expression of late disease. DESIGN Perspective. METHODS Review of the existing literature dealing with epidemiology, models, and immunologic findings in patients. RESULTS Significant genetic associations have been identified and reported, but environmentally induced (including epigenetic) changes are also an important consideration. Immune alterations include a strong interleukin 17 family signature as well as marked expression of these molecules in the eye. Oxidative stress as well as other homeostatic altering mechanisms occur throughout life. With this immune dysregulation there is a rationale for considering immunotherapy. Indeed, immunotherapy has been shown to affect the late stages of AMD. CONCLUSION Immune dysregulation appears to be an underlying alteration in AMD, as in other diseases thought to be degenerative and attributable to aging. Para-inflammation and immunosenescence may importantly contribute to the development of disease. The role of complement factor H still needs to be better defined, but in light of its association with ocular inflammatory conditions such as sarcoidosis, it does not appear to be unique to AMD but rather may be a marker for retinal pigment epithelium function. With the strong interleukin 17 family signature and the need to treat early on in the disease process, oral tolerance may be considered to prevent disease progression.
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Fritsche LG, Fariss RN, Stambolian D, Abecasis GR, Curcio CA, Swaroop A. Age-related macular degeneration: genetics and biology coming together. Annu Rev Genomics Hum Genet 2014; 15:151-71. [PMID: 24773320 DOI: 10.1146/annurev-genom-090413-025610] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Genetic and genomic studies have enhanced our understanding of complex neurodegenerative diseases that exert a devastating impact on individuals and society. One such disease, age-related macular degeneration (AMD), is a major cause of progressive and debilitating visual impairment. Since the pioneering discovery in 2005 of complement factor H (CFH) as a major AMD susceptibility gene, extensive investigations have confirmed 19 additional genetic risk loci, and more are anticipated. In addition to common variants identified by now-conventional genome-wide association studies, targeted genomic sequencing and exome-chip analyses are uncovering rare variant alleles of high impact. Here, we provide a critical review of the ongoing genetic studies and of common and rare risk variants at a total of 20 susceptibility loci, which together explain 40-60% of the disease heritability but provide limited power for diagnostic testing of disease risk. Identification of these susceptibility loci has begun to untangle the complex biological pathways underlying AMD pathophysiology, pointing to new testable paradigms for treatment.
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Affiliation(s)
- Lars G Fritsche
- Center for Statistical Genetics, Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan 48109; ,
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Abstract
Microglia are critical nervous system-specific cells influencing brain development, maintenance of the neural environment, response to injury, and repair. They contribute to neuronal proliferation and differentiation, pruning of dying neurons, synaptic remodeling and clearance of debris and aberrant proteins. Colonization of the brain occurs during gestation with an expansion following birth with localization stimulated by programmed neuronal death, synaptic pruning, and axonal degeneration. Changes in microglia phenotype relate to cellular processes including specific neurotransmitter, pattern recognition, or immune-related receptor activation. Upon activation, microglia cells have the capacity to release a number of substances, e.g., cytokines, chemokines, nitric oxide, and reactive oxygen species, which could be detrimental or beneficial to the surrounding cells. With aging, microglia shift their morphology and may display diminished capacity for normal functions related to migration, clearance, and the ability to shift from a pro-inflammatory to an anti-inflammatory state to regulate injury and repair. This shift in microglia potentially contributes to increased susceptibility and neurodegeneration as a function of age. In the current review, information is provided on the colonization of the brain by microglia, the expression of various pattern recognition receptors to regulate migration and phagocytosis, and the shift in related functions that occur in normal aging.
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Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, MD C1-04, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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Wong WT. Microglial aging in the healthy CNS: phenotypes, drivers, and rejuvenation. Front Cell Neurosci 2013; 7:22. [PMID: 23493481 PMCID: PMC3595516 DOI: 10.3389/fncel.2013.00022] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Accepted: 02/21/2013] [Indexed: 12/12/2022] Open
Abstract
Neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and age-related macular degeneration (AMD), share two characteristics in common: (1) a disease prevalence that increases markedly with advancing age, and (2) neuroinflammatory changes in which microglia, the primary resident immune cell of the CNS, feature prominently. These characteristics have led to the hypothesis that pathogenic mechanisms underlying age-related neurodegenerative disease involve aging changes in microglia. If correct, targeting features of microglial senescence may constitute a feasible therapeutic strategy. This review explores this hypothesis and its implications by considering the current knowledge on how microglia undergo change during aging and how the emergence of these aging phenotypes relate to significant alterations in microglial function. Evidence and theories on cellular mechanisms implicated in driving senescence in microglia are reviewed, as are “rejuvenative” measures and strategies that aim to reverse or ameliorate the aging microglial phenotype. Understanding and controlling microglial aging may represent an opportunity for elucidating disease mechanisms and for formulating novel therapies.
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Affiliation(s)
- Wai T Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health Bethesda, MD, USA
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Coscas G, De Benedetto U, Coscas F, Li Calzi CI, Vismara S, Roudot-Thoraval F, Bandello F, Souied E. Hyperreflective Dots: A New Spectral-Domain Optical Coherence Tomography Entity for Follow-Up and Prognosis in Exudative Age-Related Macular Degeneration. Ophthalmologica 2013; 229:32-7. [DOI: 10.1159/000342159] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 07/20/2012] [Indexed: 01/09/2023]
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Cuevas P, Outeiriño LA, Angulo J, Giménez-Gallego G. Treatment of dry age-related macular degeneration with dobesilate. BMJ Case Rep 2012; 2012:bcr.02.2012.5942. [PMID: 22729337 DOI: 10.1136/bcr.02.2012.5942] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The authors present anatomical and functional evidences of dry age-macular degeneration improvement, after intravitreal treatment with dobesilate. Main outcomes measures were normalisation of retinal structure and function, assessed by optical coherence tomography, fundus-monitored microperimetry, electrophysiology and visual acuity. The effect might be related to the normalisation of the outer retinal architecture.
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Affiliation(s)
- P Cuevas
- Departamento de Investigación, IRYCIS, Hospital Universitario Ramón y Cajal, Madrid, Spain.
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