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Crisci I, Bonzano S, Nicolas Z, Dallorto E, Peretto P, Krezel W, De Marchis S. Tamoxifen exerts direct and microglia-mediated effects preventing neuroinflammatory changes in the adult mouse hippocampal neurogenic niche. Glia 2024; 72:1273-1289. [PMID: 38515286 DOI: 10.1002/glia.24526] [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: 12/12/2023] [Revised: 02/27/2024] [Accepted: 03/05/2024] [Indexed: 03/23/2024]
Abstract
Tamoxifen-inducible systems are widely used in research to control Cre-mediated gene deletion in genetically modified animals. Beyond Cre activation, tamoxifen also exerts off-target effects, whose consequences are still poorly addressed. Here, we investigated the impact of tamoxifen on lipopolysaccharide (LPS)-induced neuroinflammatory responses, focusing on the neurogenic activity in the adult mouse dentate gyrus. We demonstrated that a four-day LPS treatment led to an increase in microglia, astrocytes and radial glial cells with concomitant reduction of newborn neurons. These effects were counteracted by a two-day tamoxifen pre-treatment. Through selective microglia depletion, we elucidated that both LPS and tamoxifen influenced astrogliogenesis via microglia mediated mechanisms, while the effects on neurogenesis persisted even in a microglia-depleted environment. Notably, changes in radial glial cells resulted from a combination of microglia-dependent and -independent mechanisms. Overall, our data reveal that tamoxifen treatment per se does not alter the balance between adult neurogenesis and astrogliogenesis but does modulate cellular responses to inflammatory stimuli exerting a protective role within the adult hippocampal neurogenic niche.
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Affiliation(s)
- Isabella Crisci
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- NICO-Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Orbassano, Italy
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U1258, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Sara Bonzano
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- NICO-Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Orbassano, Italy
| | - Zinter Nicolas
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U1258, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Eleonora Dallorto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- NICO-Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Orbassano, Italy
| | - Paolo Peretto
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- NICO-Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Orbassano, Italy
| | - Wojciech Krezel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U1258, CNRS UMR 7104, Université de Strasbourg, Illkirch, France
| | - Silvia De Marchis
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
- NICO-Neuroscience Institute Cavalieri Ottolenghi, University of Turin, Orbassano, Italy
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2
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Ghosh S, Finnemann SC, Vollrath D, Rothlin CV. In the Eyes of the Beholder-New Mertk Knockout Mouse and Re-Evaluation of Phagocytosis versus Anti-Inflammatory Functions of MERTK. Int J Mol Sci 2024; 25:5299. [PMID: 38791338 PMCID: PMC11121519 DOI: 10.3390/ijms25105299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/26/2024] Open
Abstract
Greg Lemke's laboratory was one of the pioneers of research into the TAM family of receptor tyrosine kinases (RTKs). Not only was Tyro3 cloned in his laboratory, but his group also extensively studied mice knocked out for individual or various combinations of the TAM RTKs Tyro3, Axl, and Mertk. Here we primarily focus on one of the paralogs-MERTK. We provide a historical perspective on rodent models of loss of Mertk function and their association with retinal degeneration and blindness. We describe later studies employing mouse genetics and the generation of newer knockout models that point out incongruencies with the inference that loss of MERTK-dependent phagocytosis is sufficient for severe, early-onset photoreceptor degeneration in mice. This discussion is meant to raise awareness with regards to the limitations of the original Mertk knockout mouse model generated using 129 derived embryonic stem cells and carrying 129 derived alleles and the role of these alleles in modifying Mertk knockout phenotypes or even displaying Mertk-independent phenotypes. We also suggest molecular approaches that can further Greg Lemke's scintillating legacy of dissecting the molecular functions of MERTK-a protein that has been described to function in phagocytosis as well as in the negative regulation of inflammation.
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Affiliation(s)
- Sourav Ghosh
- Department of Neurology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Silvia C. Finnemann
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA;
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA;
| | - Carla V. Rothlin
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
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3
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Lee TT, Bell BA, Anderson BD, Song Y, Dunaief JL. Tamoxifen protects photoreceptors in the sodium iodate model. Exp Eye Res 2024; 242:109879. [PMID: 38570182 PMCID: PMC11055656 DOI: 10.1016/j.exer.2024.109879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024]
Abstract
Because the selective estrogen receptor modulator tamoxifen was shown to be retina-protective in the light damage and rd10 models of retinal degeneration, the purpose of this study was to test whether tamoxifen is retina-protective in a model where retinal pigment epithelium (RPE) toxicity appears to be the primary insult: the sodium iodate (NaIO3) model. C57Bl/6J mice were given oral tamoxifen (in the diet) or the same diet lacking tamoxifen, then given an intraperitoneal injection of NaIO3 at 25 mg/kg. The mice were imaged a week later using optical coherence tomography (OCT). ImageJ with a custom macro was utilized to measure retinal thicknesses in OCT images. Electroretinography (ERG) was used to measure retinal function one week post-injection. After euthanasia, quantitative real-time PCR (qRT-PCR) was performed. Tamoxifen administration partially protected photoreceptors. There was less photoreceptor layer thinning in OCT images of tamoxifen-treated mice. qRT-PCR revealed, in the tamoxifen-treated group, less upregulation of antioxidant and complement factor 3 mRNAs, and less reduction in the rhodopsin and short-wave cone opsin mRNAs. Furthermore, ERG results demonstrated preservation of photoreceptor function for the tamoxifen-treated group. Cone function was better protected than rods. These results indicate that tamoxifen provided structural and functional protection to photoreceptors against NaIO3. RPE cells were not protected. These neuroprotective effects suggest that estrogen-receptor modulation may be retina-protective. The fact that cones are particularly protected is intriguing given their importance for human visual function and their survival until the late stages of retinitis pigmentosa. Further investigation of this protective pathway could lead to new photoreceptor-protective therapeutics.
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Affiliation(s)
- Timothy T Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brent A Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brandon D Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Ying Song
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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4
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Ahn SJ, Kim J, Kwon HY. Nationwide Screening Practices for Tamoxifen Retinal Toxicity in South Korea: A Population-Based Cohort Study. J Clin Med 2024; 13:2167. [PMID: 38673439 PMCID: PMC11050852 DOI: 10.3390/jcm13082167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 04/06/2024] [Accepted: 04/07/2024] [Indexed: 04/28/2024] Open
Abstract
(1) Background/Objectives: To investigate the nationwide screening practices and trends in tamoxifen retinal toxicity (tamoxifen retinopathy) in South Korea using national health insurance claims data. (2) Methods: A total of 43,848 patients who started tamoxifen therapy between 2015 and 2020 and had no prior ophthalmic diseases or other conditions requiring screening for retinopathy were included. The annual numbers of tamoxifen users and new initiators of tamoxifen therapy were assessed. The screening examinations were separated into baseline (first ophthalmic examination after tamoxifen administration) and subsequent monitoring examinations. The timing and modalities for the baseline and subsequent monitoring examinations performed between 2015 and 2021 were assessed in tamoxifen users. (3) Results: The annual number of tamoxifen users increased over the study period from 54,056 in 2015 to 81,720 in 2021. The number of patients who underwent ophthalmic examination after tamoxifen administration was 8961 (20.4%). Baseline screening was performed in 6.5% of patients within 1 year of use, and subsequent monitoring was performed in 27.8% of patients who underwent baseline screening. Funduscopy or fundus photography was performed most commonly for baseline screening and subsequent monitoring (99.0% and 98.6%, respectively), while optical coherence tomography was performed only in 21.9% and 29.6% of baseline and monitoring examinations, respectively. The average number of monitoring examinations per year was 0.68 ± 0.45. Although the annual percentage of patients receiving a baseline examination within 1 year gradually increased over time, the percentage of those with subsequent monitoring performed within 1 year was similar over the study period. (4) Conclusions: Our finding, appropriate screening in a small proportion of patients receiving tamoxifen, suggests the need to promote awareness among healthcare professionals and develop a standardized approach for screening for tamoxifen retinopathy.
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Affiliation(s)
- Seong Joon Ahn
- Department of Ophthalmology, Hanyang University Hospital, Hanyang University College of Medicine, 222-1 Wangsipli-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Jiyeong Kim
- Department of Pre-Medicine, College of Medicine, and Biostatistics Lab, Medical Research Collaborating Center (MRCC), Hanyang University, Seoul 04763, Republic of Korea
| | - Hyeon Yoon Kwon
- Department of Ophthalmology, Hanyang University Hospital, Hanyang University College of Medicine, 222-1 Wangsipli-ro, Seongdong-gu, Seoul 04763, Republic of Korea
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5
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Yang H, Zhang H, Li X. Navigating the future of retinitis pigmentosa treatments: A comprehensive analysis of therapeutic approaches in rd10 mice. Neurobiol Dis 2024; 193:106436. [PMID: 38341159 DOI: 10.1016/j.nbd.2024.106436] [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: 12/27/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
Retinitis pigmentosa (RP) is a degenerative disease, caused by genetic mutations that lead to a loss in photoreceptors. For research on RP, rd10 mice, which carry mutations in the phosphodiesterase (PDE) gene, exhibit degenerative patterns comparable to those of patients with RP, making them an ideal model for investigating potential treatments. Although numerous studies have reported the potential of biochemical drugs, gene correction, and stem cell transplantation in decelerating rd10 retinal degeneration, a comprehensive review of these studies has yet to be conducted. Therefore, here, a comparative analysis of rd10 mouse treatment research over the past decade was performed. Our findings suggest that biochemical drugs capable of inhibiting the inflammatory response may be promising therapeutics. Additionally, significant progress has been made in the field of gene therapy; nevertheless, challenges such as strict delivery requirements, bystander editing, and off-target effects still need to be resolved. Nevertheless, secretory function is the only unequivocal protective effect of stem cell transplantation. In summary, this review presents a comprehensive analysis and synthesis of the treatment approaches employing rd10 mice as experimental subjects, describing a clear pathway for future RP treatment research and identifies potential clinical interventions.
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Affiliation(s)
- Hongli Yang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Tianjin 300384, China.
| | - Hui Zhang
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Tianjin 300384, China
| | - Xiaorong Li
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, No. 251, Fukang Road, Tianjin 300384, China.
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Anderson BD, Lee TT, Bell BA, Wang T, Dunaief JL. Optimizing the sodium iodate model: Effects of dose, gender, and age. Exp Eye Res 2024; 239:109772. [PMID: 38158173 PMCID: PMC10922497 DOI: 10.1016/j.exer.2023.109772] [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: 10/24/2023] [Revised: 12/26/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Sodium iodate (NaIO3) is a commonly used model for age-related macular degeneration (AMD), but its rapid and severe induction of retinal pigment epithelial (RPE) and photoreceptor degeneration can lead to the premature dismissal of potentially effective therapeutics. Additionally, little is known about how sex and age affect the retinal response to NaIO3. This study aims to establish a less severe yet reproducible regimen by testing low doses of NaIO3 while considering age- and sex-related effects, enabling a broader range of therapeutic evaluations. In this study, young (3-5 months) and old (18-24 months) male and female C57Bl/6J mice were given an intraperitoneal (IP) injection of 15, 20, or 25 mg/kg NaIO3. Damage assessment one week post-injection included in vivo imaging, histological examination, and qRT-PCR analysis. The results revealed that young mice showed no damage at 15 mg/kg IP NaIO3, with varying degrees of damage observed at 20 mg/kg. At 25 mg/kg, most young mice displayed widespread retinal damage, with females exhibiting less retinal thinning than males. In contrast, older mice at 20 and 25 mg/kg displayed a more patchy degeneration pattern, outer retinal undulations, and greater variability in degeneration than the young mice. The most effective model for minimizing damage while maintaining consistency utilizes young female mice injected with 25 mg/kg NaIO3. The observed sex- and age-related differences underscore the importance of considering these variables in research, aligning with the National Institutes of Health's guidance. While the model does not fully replicate the complexity of AMD, these findings enhance its utility as a valuable tool for testing RPE/photoreceptor protective or replacement therapies.
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Affiliation(s)
- Brandon D Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Timothy T Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brent A Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Tan Wang
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA; Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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7
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Maes ME, Colombo G, Schoot Uiterkamp FE, Sternberg F, Venturino A, Pohl EE, Siegert S. Mitochondrial network adaptations of microglia reveal sex-specific stress response after injury and UCP2 knockout. iScience 2023; 26:107780. [PMID: 37731609 PMCID: PMC10507162 DOI: 10.1016/j.isci.2023.107780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/10/2023] [Accepted: 08/28/2023] [Indexed: 09/22/2023] Open
Abstract
Mitochondrial networks remodel their connectivity, content, and subcellular localization to support optimized energy production in conditions of increased environmental or cellular stress. Microglia rely on mitochondria to respond to these stressors, however our knowledge about mitochondrial networks and their adaptations in microglia in vivo is limited. Here, we generate a mouse model that selectively labels mitochondria in microglia. We identify that mitochondrial networks are more fragmented with increased content and perinuclear localization in vitro vs. in vivo. Mitochondrial networks adapt similarly in microglia closest to the injury site after optic nerve crush. Preventing microglial UCP2 increase after injury by selective knockout induces cellular stress. This results in mitochondrial hyperfusion in male microglia, a phenotype absent in females due to circulating estrogens. Our results establish the foundation for mitochondrial network analysis of microglia in vivo, emphasizing the importance of mitochondrial-based sex effects of microglia in other pathologies.
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Affiliation(s)
- Margaret E. Maes
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Gloria Colombo
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | | | - Felix Sternberg
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Alessandro Venturino
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Elena E. Pohl
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - Sandra Siegert
- Institute of Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria
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8
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Klann IP, Fulco BCW, Nogueira CW. Subchronic exposure to Tamoxifen modulates the hippocampal BDNF/ERK/Akt/CREB pathway and impairs memory in intact female rats. Chem Biol Interact 2023; 382:110615. [PMID: 37392961 DOI: 10.1016/j.cbi.2023.110615] [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: 03/29/2023] [Revised: 06/13/2023] [Accepted: 06/27/2023] [Indexed: 07/03/2023]
Abstract
Tamoxifen (TAM), a Selective Estrogen Receptor Modulator (SERM), is commonly used to treat and prevent breast cancer. Memory impairment has been noticed in patients who experience hormone therapy in the case of TAM and other SERMs. Animal studies that mimic the TAM longer exposure effects are needed to better elucidate the adverse effects of continuous treatment in humans. This study evaluated the effects of TAM subchronic administration on the memory performance and hippocampal neural plasticity of intact female Wistar rats. Animals were treated intragastrically with TAM (0.25 and 2.5 mg/kg) for 59 days. The rats were subjected to the Object Location Test (OLT) and Object Recognition Test (ORT) to evaluate memory performance. After euthanasia, the hippocampus samples were excised and the protein levels of the BDNF/ERK/Akt/CREB pathway were evaluated. The rat's locomotor activity and hippocampal TrkB levels were similar among the experimental groups. TAM at both doses reduced the memory performance of female rats in the OLT and short-term memory of ORT, and impaired hippocampal levels of mBDNF, proBDNF, and pCREB/CREB. TAM only at the dose of 2.5 mg/kg reduced the memory performance of rats in the long-term memory of ORT and hippocampal pERK/ERK and pAkt/Akt ratios. TAM subchronic administration induced amnesic effects and modulated the hippocampal BDNF/ERK/Akt/CREB pathway in intact young adult female Wistar rats.
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Affiliation(s)
- Isabella P Klann
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, CCNE, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Bruna C W Fulco
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, CCNE, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Cristina W Nogueira
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, CCNE, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
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9
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Díaz-Lezama N, Kajtna J, Wu J, Ayten M, Koch SF. Microglial and macroglial dynamics in a model of retinitis pigmentosa. Vision Res 2023; 210:108268. [PMID: 37295269 DOI: 10.1016/j.visres.2023.108268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
In retinal degenerative diseases, such as retinitis pigmentosa (RP), the characteristic photoreceptor cell death is associated with changes of microglia and macroglia cells. Gene therapy, a promising treatment option for RP, is based on the premise that glial cell remodeling does not impact vision rescue. However, the dynamics of glial cells after treatment at late disease stages are not well understood. Here, we tested the reversibility of specific RP glia phenotypes in a Pde6b-deficient RP gene therapy mouse model. We demonstrated an increased number of activated microglia, retraction of microglial processes, reactive gliosis of Müller cells, astrocyte remodelling and an upregulation of glial fibrillary acidic protein (GFAP) in response to photoreceptor degeneration. Importantly, these changes returned to normal following rod rescue at late disease stages. These results suggest that therapeutic approaches restore the homeostasis between photoreceptors and glial cells.
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Affiliation(s)
- Nundehui Díaz-Lezama
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Jacqueline Kajtna
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Jiou Wu
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Monika Ayten
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Susanne F Koch
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany.
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Pietrzak BA, Wnuk A, Przepiórska K, Łach A, Kajta M. Posttreatment with Ospemifene Attenuates Hypoxia- and Ischemia-Induced Apoptosis in Primary Neuronal Cells via Selective Modulation of Estrogen Receptors. Neurotox Res 2023; 41:362-379. [PMID: 37129835 PMCID: PMC10354152 DOI: 10.1007/s12640-023-00644-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/17/2023] [Accepted: 04/02/2023] [Indexed: 05/03/2023]
Abstract
Stroke and perinatal asphyxia have detrimental effects on neuronal cells, causing millions of deaths worldwide each year. Since currently available therapies are insufficient, there is an urgent need for novel neuroprotective strategies to address the effects of cerebrovascular accidents. One such recent approach is based on the neuroprotective properties of estrogen receptors (ERs). However, activation of ERs by estrogens may contribute to the development of endometriosis or hormone-dependent cancers. Therefore, in this study, we utilized ospemifene, a novel selective estrogen receptor modulator (SERM) already used in dyspareunia treatment. Here, we demonstrated that posttreatment with ospemifene in primary neocortical cell cultures subjected to 18 h of hypoxia and/or ischemia followed by 6 h of reoxygenation has robust neuroprotective potential. Ospemifene partially reverses hypoxia- and ischemia-induced changes in LDH release, the degree of neurodegeneration, and metabolic activity. The mechanism of the neuroprotective actions of ospemifene involves the inhibition of apoptosis since the compound decreases caspase-3 overactivity during hypoxia and enhances mitochondrial membrane potential during ischemia. Moreover, in both models, ospemifene decreased the levels of the proapoptotic proteins BAX, FAS, FASL, and GSK3β while increasing the level of the antiapoptotic protein BCL2. Silencing of specific ERs showed that the neuroprotective actions of ospemifene are mediated mainly via ESR1 (during hypoxia and ischemia) and GPER1 (during hypoxia), which is supported by ospemifene-evoked increases in ESR1 protein levels in hypoxic and ischemic neurons. The results identify ospemifene as a promising neuroprotectant, which in the future may be used to treat injuries due to brain hypoxia/ischemia.
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Affiliation(s)
- Bernadeta A Pietrzak
- Laboratory of Neuropharmacology and Epigenetics, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna Street 12, Krakow, 31-343, Poland
| | - Agnieszka Wnuk
- Laboratory of Neuropharmacology and Epigenetics, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna Street 12, Krakow, 31-343, Poland
| | - Karolina Przepiórska
- Laboratory of Neuropharmacology and Epigenetics, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna Street 12, Krakow, 31-343, Poland
| | - Andrzej Łach
- Laboratory of Neuropharmacology and Epigenetics, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna Street 12, Krakow, 31-343, Poland
| | - Małgorzata Kajta
- Laboratory of Neuropharmacology and Epigenetics, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna Street 12, Krakow, 31-343, Poland.
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11
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Yan W, Sun Y, Wang Y, Liang W, Xia Y, Yan W, Chen M, Chen T, Li D. The impacts of resveratrol on the retinal degeneration in a rat model of retinitis pigmentosa induced by alkylation: an in-vivo study. Anim Cells Syst (Seoul) 2023; 27:138-148. [PMID: 37388281 PMCID: PMC10304456 DOI: 10.1080/19768354.2023.2226695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 02/14/2023] [Accepted: 03/12/2023] [Indexed: 07/01/2023] Open
Abstract
Upregulation of Sirtuin Type 1 (SIRT1), a nicotinamide adeninedinucleotide (NAD+)-dependent deacetylase, has been proved to protect against ample ocular diseases, while its effect on retinitis pigmentosa (RP) has not been illustrated. The study was aimed to explore the impacts of resveratrol (RSV), a SIRT1 activator, on the photoreceptor degeneration in a rat model of RP induced by N-methyl-N-nitrosourea (MNU), an alkylation. The rats were induced RP phenotypes via the intraperitoneal injection of MNU. The electroretinogram was conducted and revealed that RSV could not prevent the decline of retinal function in the RP rats. The optical coherence tomography (OCT) and the retinal histological examination were performed and showed that the reduced thickness of the outer nuclear layer (ONL) was not preserved by RSV intervention. The immunostaining technique was applied. Afther the MNU administration, the number of the apoptotic photoreceptors in the ONL throughout the retinasand the number of microglia cells present among the outer part throughout the retinas were not significantly reduced by RSV. Western blotting was also performed. The data showed that the level of SIRT1 protein was decreased after MNU administration, while RSV was not able to obviously alleviate the downregulation. Our data together indicated that RSV was not able to rescue the photoreceptor degeneration in the MNU-induced RP rats, which might be due to the MNU-induced consumption of the NAD+.
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Affiliation(s)
- Weiming Yan
- Department of Ophthalmology, The 900th Hospital of Joint Logistic Support Force, PLA (Clinical Medical College of Fujian Medical University, Dongfang Hopsital Affiliated to Xiamen University), Fuzhou, People’s Republic of China
- Center of Clinical Aerospace Medicine, Air Force Military Medical University, Xi’an, People’s Republic of China
| | - Yan Sun
- Department of Ophthalmology, The 900th Hospital of Joint Logistic Support Force, PLA (Clinical Medical College of Fujian Medical University, Dongfang Hopsital Affiliated to Xiamen University), Fuzhou, People’s Republic of China
| | - Yutong Wang
- Department of Ophthalmology, The 900th Hospital of Joint Logistic Support Force, PLA (Clinical Medical College of Fujian Medical University, Dongfang Hopsital Affiliated to Xiamen University), Fuzhou, People’s Republic of China
| | - Wangjiao Liang
- Department of Ophthalmology, The 900th Hospital of Joint Logistic Support Force, PLA (Clinical Medical College of Fujian Medical University, Dongfang Hopsital Affiliated to Xiamen University), Fuzhou, People’s Republic of China
| | - Yuxin Xia
- Department of Ophthalmology, The 900th Hospital of Joint Logistic Support Force, PLA (Clinical Medical College of Fujian Medical University, Dongfang Hopsital Affiliated to Xiamen University), Fuzhou, People’s Republic of China
| | - Weihua Yan
- Changtai No.2 High School of Fujian Province, Zhangzhou, People’s Republic of China
| | - Meizhu Chen
- Department of Ophthalmology, The 900th Hospital of Joint Logistic Support Force, PLA (Clinical Medical College of Fujian Medical University, Dongfang Hopsital Affiliated to Xiamen University), Fuzhou, People’s Republic of China
| | - Tao Chen
- Center of Clinical Aerospace Medicine, Air Force Military Medical University, Xi’an, People’s Republic of China
| | - Dongliang Li
- Department of Hepatobiliary Disease, The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou, People’s Republic of China
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12
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Zhu X, Liu W, Tang X, Chen Y, Ge X, Ke Q, Liang X, Gan Y, Zheng Y, Zou M, Deng M, Liu Y, Li DWC, Gong L. The BET PROTAC inhibitor dBET6 protects against retinal degeneration and inhibits the cGAS-STING in response to light damage. J Neuroinflammation 2023; 20:119. [PMID: 37217935 DOI: 10.1186/s12974-023-02804-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 05/11/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Chronic inflammation significantly contributes to photoreceptor death in blinding retinal diseases such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). Bromodomain and extraterminal domain (BET) proteins are epigenetic readers that act as key proinflammatory factors. We recently found the first-generation BET inhibitor JQ1 alleviated sodium iodate-induced retinal degeneration by suppressing cGAS-STING innate immunity. Here, we investigated the effects and mechanism of dBET6, a proteolysis‑targeting chimera (PROTAC) small molecule that selectively degrades BET by the ubiquitin‒proteasome system, in light-induced retinal degeneration. METHODS Mice were exposed to bright light to induce retinal degeneration, and the activation of cGAS-STING was determined by RNA-sequencing and molecular biology. Retinal function, morphology, photoreceptor viability and retinal inflammation were examined in the presence and absence of dBET6 treatment. RESULTS Intraperitoneal injection of dBET6 led to the rapid degradation of BET protein in the retina without detectable toxicity. dBET6 improved retinal responsiveness and visual acuity after light damage (LD). dBET6 also repressed LD-induced retinal macrophages/microglia activation, Müller cell gliosis, photoreceptor death and retinal degeneration. Analysis of single-cell RNA-sequencing results revealed cGAS-STING components were expressed in retinal microglia. LD led to dramatic activation of the cGAS-STING pathway, whereas dBET6 suppressed LD-induced STING expression in reactive macrophages/microglia and the related inflammatory response. CONCLUSIONS This study indicates targeted degradation of BET by dBET6 exerts neuroprotective effects by inhibiting cGAS-STING in reactive retinal macrophages/microglia, and is expected to become a new strategy for treatment of retinal degeneration.
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Affiliation(s)
- Xingfei Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Wei Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Xiangcheng Tang
- Shenzhen Key Laboratory of Ophthalmology, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Yulin Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Xiangyu Ge
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Qin Ke
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Xingmiao Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Yuwen Gan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Yingfeng Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - Ming Zou
- Peking University International Cancer Institute, Health Science Center, Peking University, Beijing, China
| | - Mi Deng
- Peking University International Cancer Institute, Health Science Center, Peking University, Beijing, China
- Peking University Cancer Hospital and Institute, Peking University, Beijing, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China
| | - David Wan-Cheng Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China.
| | - Lili Gong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, 510060, Guangdong, China.
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13
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Mercau ME, Akalu YT, Mazzoni F, Gyimesi G, Alberto EJ, Kong Y, Hafler BP, Finnemann SC, Rothlin CV, Ghosh S. Inflammation of the retinal pigment epithelium drives early-onset photoreceptor degeneration in Mertk-associated retinitis pigmentosa. SCIENCE ADVANCES 2023; 9:eade9459. [PMID: 36662852 PMCID: PMC9858494 DOI: 10.1126/sciadv.ade9459] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 12/19/2022] [Indexed: 05/17/2023]
Abstract
Severe, early-onset photoreceptor (PR) degeneration associated with MERTK mutations is thought to result from failed phagocytosis by retinal pigment epithelium (RPE). Notwithstanding, the severity and onset of PR degeneration in mouse models of Mertk ablation are determined by the hypomorphic expression or the loss of the Mertk paralog Tyro3. Here, we find that loss of Mertk and reduced expression/loss of Tyro3 led to RPE inflammation even before eye-opening. Incipient RPE inflammation cascaded to involve microglia activation and PR degeneration with monocyte infiltration. Inhibition of RPE inflammation with the JAK1/2 inhibitor ruxolitinib mitigated PR degeneration in Mertk-/- mice. Neither inflammation nor severe, early-onset PR degeneration was observed in mice with defective phagocytosis alone. Thus, inflammation drives severe, early-onset PR degeneration-associated with Mertk loss of function.
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Affiliation(s)
- Maria E. Mercau
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Yemsratch T. Akalu
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Francesca Mazzoni
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Gavin Gyimesi
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Emily J. Alberto
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Yong Kong
- Department of Molecular Biophysics and Biochemistry, W. M. Keck Foundation Biotechnology Resource Laboratory, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Brian P. Hafler
- Department of Ophthalmology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Pathology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Silvia C. Finnemann
- Center for Cancer, Genetic Diseases and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY 10458, USA
| | - Carla V. Rothlin
- Department of Immunobiology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Sourav Ghosh
- Department of Pharmacology, School of Medicine, Yale University, New Haven, CT 06520, USA
- Department of Neurology, School of Medicine, Yale University, New Haven, CT 06520, USA
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14
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Kikuchi Y, Sugano E, Yuki S, Tabata K, Endo Y, Takita Y, Onoguchi R, Ozaki T, Fukuda T, Takai Y, Kurose T, Tanaka K, Honma Y, Perez E, Stock M, Fernández JR, Tamura M, Voronkov M, Stock JB, Tomita H. SIG-1451, a Novel, Non-Steroidal Anti-Inflammatory Compound, Attenuates Light-Induced Photoreceptor Degeneration by Affecting the Inflammatory Process. Int J Mol Sci 2022; 23:ijms23158802. [PMID: 35955937 PMCID: PMC9369167 DOI: 10.3390/ijms23158802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
Age-related macular degeneration is a progressive retinal disease that is associated with factors such as oxidative stress and inflammation. In this study, we evaluated the protective effects of SIG-1451, a non-steroidal anti-inflammatory compound developed for treating atopic dermatitis and known to inhibit Toll-like receptor 4, in light-induced photoreceptor degeneration. SIG-1451 was intraperitoneally injected into rats once per day before exposure to 1000 lx light for 24 h; one day later, optical coherence tomography showed a decrease in retinal thickness, and electroretinogram (ERG) amplitude was also found to have decreased 3 d after light exposure. Moreover, SIG-1451 partially protected against this decrease in retinal thickness and increase in ERG amplitude. One day after light exposure, upregulation of inflammatory response-related genes was observed, and SIG-1451 was found to inhibit this upregulation. Iba-1, a microglial marker, was suppressed in SIG-1451-injected rats. To investigate the molecular mechanism underlying these effects, we used lipopolysaccharide (LPS)-stimulated rat immortalised Müller cells. The upregulation of C-C motif chemokine 2 by LPS stimulation was significantly inhibited by SIG-1451 treatment, and Western blot analysis revealed a decrease in phosphorylated I-κB levels. These results indicate that SIG-1451 indirectly protects photoreceptor cells by attenuating light damage progression, by affecting the inflammatory responses.
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Affiliation(s)
- Yuki Kikuchi
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Eriko Sugano
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Shiori Yuki
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Kitako Tabata
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Yuka Endo
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Yuya Takita
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Reina Onoguchi
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Taku Ozaki
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Tomokazu Fukuda
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
| | - Yoshihiro Takai
- Rohto Pharmaceutical Co., Ltd., 6-5-4 Kunimidai, Kizugawa 619-0216, Kyoto, Japan
| | - Takahiro Kurose
- Rohto Pharmaceutical Co., Ltd., 6-5-4 Kunimidai, Kizugawa 619-0216, Kyoto, Japan
| | - Koichi Tanaka
- Rohto Pharmaceutical Co., Ltd., 6-5-4 Kunimidai, Kizugawa 619-0216, Kyoto, Japan
| | - Yoichi Honma
- Rohto Pharmaceutical Co., Ltd., 6-5-4 Kunimidai, Kizugawa 619-0216, Kyoto, Japan
| | - Eduardo Perez
- Signum Biosciences, 4999 Pearl East Circle, Boulder, CO 80301, USA
| | - Maxwell Stock
- Signum Biosciences, 4999 Pearl East Circle, Boulder, CO 80301, USA
| | | | - Masanori Tamura
- Signum Biosciences, 4999 Pearl East Circle, Boulder, CO 80301, USA
| | - Michael Voronkov
- Signum Biosciences, 4999 Pearl East Circle, Boulder, CO 80301, USA
| | - Jeffry B. Stock
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014, USA
| | - Hiroshi Tomita
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka 020-8551, Iwate, Japan
- Correspondence: ; Tel.: +81-19-621-6427
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15
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Retinal Toxicity Induced by Chemical Agents. Int J Mol Sci 2022; 23:ijms23158182. [PMID: 35897758 PMCID: PMC9331776 DOI: 10.3390/ijms23158182] [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: 06/23/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/16/2022] Open
Abstract
Vision is an important sense for humans, and visual impairment/blindness has a huge impact in daily life. The retina is a nervous tissue that is essential for visual processing since it possesses light sensors (photoreceptors) and performs a pre-processing of visual information. Thus, retinal cell dysfunction or degeneration affects visual ability and several general aspects of the day-to-day of a person's lives. The retina has a blood-retinal barrier, which protects the tissue from a wide range of molecules or microorganisms. However, several agents, coming from systemic pathways, reach the retina and influence its function and survival. Pesticides are still used worldwide for agriculture, contaminating food with substances that could reach the retina. Natural products have also been used for therapeutic purposes and are another group of substances that can get to the retina. Finally, a wide number of medicines administered for different diseases can also affect the retina. The present review aimed to gather recent information about the hazard of these products to the retina, which could be used to encourage the search for more healthy, suitable, or less risky agents.
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16
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Fogerty J, Song P, Boyd P, Grabinski SE, Hoang T, Reich A, Cianciolo LT, Blackshaw S, Mumm JS, Hyde DR, Perkins BD. Notch Inhibition Promotes Regeneration and Immunosuppression Supports Cone Survival in a Zebrafish Model of Inherited Retinal Dystrophy. J Neurosci 2022; 42:5144-5158. [PMID: 35672150 PMCID: PMC9236296 DOI: 10.1523/jneurosci.0244-22.2022] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/18/2022] [Accepted: 05/13/2022] [Indexed: 12/31/2022] Open
Abstract
Photoreceptor degeneration leads to irreversible vision loss in humans with retinal dystrophies such as retinitis pigmentosa. Whereas photoreceptor loss is permanent in mammals, zebrafish possesses the ability to regenerate retinal neurons and restore visual function. Following acute damage, Müller glia (MG) re-enter the cell cycle and produce multipotent progenitors whose progeny differentiate into mature neurons. Both MG reprogramming and proliferation of retinal progenitor cells require reactive microglia and associated inflammatory signaling. Paradoxically, in zebrafish models of retinal degeneration, photoreceptor death does not induce the MG to reprogram and regenerate lost cells. Here, we used male and female zebrafish cep290 mutants to demonstrate that progressive cone degeneration generates an immune response but does not stimulate MG proliferation. Acute light damage triggered photoreceptor regeneration in cep290 mutants but cones were only restored to prelesion densities. Using irf8 mutant zebrafish, we found that the chronic absence of microglia reduced inflammation and rescued cone degeneration in cep290 mutants. Finally, single-cell RNA-sequencing revealed sustained expression of notch3 in MG of cep290 mutants and inhibition of Notch signaling induced MG to re-enter the cell cycle. Our findings provide new insights on the requirements for MG to proliferate and the potential for immunosuppression to prolong photoreceptor survival.SIGNIFICANCE STATEMENT Inherited retinal degenerations (IRDs) are genetic diseases that lead to the progressive loss of photoreceptors and the permanent loss of vision. Zebrafish can regenerate photoreceptors after acute injury by reprogramming Müller glia (MG) into stem-like cells that produce retinal progenitors, but this regenerative process fails to occur in zebrafish models of IRDs. Here, we show that Notch pathway inhibition can promote photoreceptor regeneration in models of progressive degeneration and that immunosuppression can prevent photoreceptor loss. These results offer insight into the pathways that promote MG-dependent regeneration and the role of inflammation in photoreceptor degeneration.
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Affiliation(s)
- Joseph Fogerty
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Ping Song
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Patrick Boyd
- Department of Biological Sciences, Center for Zebrafish Research, and Center for Stem Cells and Regenerative Medicine, University of Notre Dame, Notre Dame, Indiana 46556
| | - Sarah E Grabinski
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Thanh Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Adrian Reich
- Florida Research and Innovation Center, Lerner Research Institute, Cleveland Clinic, Port St. Lucie, Florida 34987
| | - Lauren T Cianciolo
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Jeff S Mumm
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - David R Hyde
- Department of Biological Sciences, Center for Zebrafish Research, and Center for Stem Cells and Regenerative Medicine, University of Notre Dame, Notre Dame, Indiana 46556
| | - Brian D Perkins
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio 44195
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio 44195
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17
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Fan W, Huang W, Chen J, Li N, Mao L, Hou S. Retinal microglia: Functions and diseases. Immunology 2022; 166:268-286. [PMID: 35403700 DOI: 10.1111/imm.13479] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/26/2022] [Accepted: 02/22/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Wei Fan
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
- Chongqing Key Laboratory of Ophthalmology Chongqing China
- Chongqing Eye Institute Chongqing China
- Chongqing Branch of National Clinical Research Center for Ocular Diseases Chongqing China
| | - Weidi Huang
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
- Department of Ophthalmology, Second Xiangya Hospital Central South University Changsha Hunan China
| | - Jiayi Chen
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
| | - Na Li
- College of Basic Medicine Chongqing Medical University Chongqing China
| | - Liming Mao
- Department of Immunology School of Medicine, Nantong University, 19 Qixiu Road Nantong Jiangsu China
| | - Shengping Hou
- The First Affiliated Hospital of Chongqing Medical University Chongqing China
- Chongqing Key Laboratory of Ophthalmology Chongqing China
- Chongqing Eye Institute Chongqing China
- Chongqing Branch of National Clinical Research Center for Ocular Diseases Chongqing China
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18
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Wang SK, Cepko CL. Targeting Microglia to Treat Degenerative Eye Diseases. Front Immunol 2022; 13:843558. [PMID: 35251042 PMCID: PMC8891158 DOI: 10.3389/fimmu.2022.843558] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 01/31/2022] [Indexed: 12/29/2022] Open
Abstract
Microglia have been implicated in many degenerative eye disorders, including retinitis pigmentosa, age-related macular degeneration, glaucoma, diabetic retinopathy, uveitis, and retinal detachment. While the exact roles of microglia in these conditions are still being discovered, evidence from animal models suggests that they can modulate the course of disease. In this review, we highlight current strategies to target microglia in the eye and their potential as treatments for both rare and common ocular disorders. These approaches include depleting microglia with chemicals or radiation, reprogramming microglia using homeostatic signals or other small molecules, and inhibiting the downstream effects of microglia such as by blocking cytokine activity or phagocytosis. Finally, we describe areas of future research needed to fully exploit the therapeutic value of microglia in eye diseases.
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Affiliation(s)
- Sean K. Wang
- Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Constance L. Cepko
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, United States
- Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
- Howard Hughes Medical Institute, Chevy Chase, MD, United States
- *Correspondence: Constance L. Cepko,
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19
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Brunet AA, Harvey AR, Carvalho LS. Primary and Secondary Cone Cell Death Mechanisms in Inherited Retinal Diseases and Potential Treatment Options. Int J Mol Sci 2022; 23:ijms23020726. [PMID: 35054919 PMCID: PMC8775779 DOI: 10.3390/ijms23020726] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/05/2022] [Accepted: 01/05/2022] [Indexed: 12/13/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a leading cause of blindness. To date, 260 disease-causing genes have been identified, but there is currently a lack of available and effective treatment options. Cone photoreceptors are responsible for daylight vision but are highly susceptible to disease progression, the loss of cone-mediated vision having the highest impact on the quality of life of IRD patients. Cone degeneration can occur either directly via mutations in cone-specific genes (primary cone death), or indirectly via the primary degeneration of rods followed by subsequent degeneration of cones (secondary cone death). How cones degenerate as a result of pathological mutations remains unclear, hindering the development of effective therapies for IRDs. This review aims to highlight similarities and differences between primary and secondary cone cell death in inherited retinal diseases in order to better define cone death mechanisms and further identify potential treatment options.
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Affiliation(s)
- Alicia A. Brunet
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Lions Eye Institute Ltd., 2 Verdun St, Nedlands, WA 6009, Australia
- Correspondence: ; Tel.: +61-423-359-714
| | - Alan R. Harvey
- School of Human Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Perron Institute for Neurological and Translational Science, 8 Verdun St, Nedlands, WA 6009, Australia
| | - Livia S. Carvalho
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009, Australia;
- Lions Eye Institute Ltd., 2 Verdun St, Nedlands, WA 6009, Australia
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20
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Pepe G, Sfogliarini C, Rizzello L, Battaglia G, Pinna C, Rovati G, Ciana P, Brunialti E, Mornata F, Maggi A, Locati M, Vegeto E. ERα-independent NRF2-mediated immunoregulatory activity of tamoxifen. Biomed Pharmacother 2021; 144:112274. [PMID: 34653752 DOI: 10.1016/j.biopha.2021.112274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 12/30/2022] Open
Abstract
Sex differences in immune-mediated diseases are linked to the activity of estrogens on innate immunity cells, including macrophages. Tamoxifen (TAM) is a selective estrogen receptor modulator (SERM) used in estrogen receptor-alpha (ERα)-dependent breast cancers and off-target indications such as infections, although the immune activity of TAM and its active metabolite, 4-OH tamoxifen (4HT), is poorly characterized. Here, we aimed at investigating the endocrine and immune activity of these SERMs in macrophages. Using primary cultures of female mouse macrophages, we analyzed the expression of immune mediators and activation of effector functions in competition experiments with SERMs and 17β-estradiol (E2) or the bacterial endotoxin LPS. We observed that 4HT and TAM induce estrogen antagonist effects when used at nanomolar concentrations, while pharmacological concentrations that are reached by TAM in clinical settings regulate the expression of VEGFα and other immune activation genes by ERα- and G protein-coupled receptor 1 (GPER1)-independent mechanisms that involve NRF2 through PI3K/Akt-dependent mechanisms. Importantly, we observed that SERMs potentiate cell phagocytosis and modify the effects of LPS on the expression of inflammatory cytokines, such as TNFα and IL1β, with an overall increase in cell inflammatory phenotype, further sustained by potentiation of IL1β secretion through caspase-1 activation. Altogether, our data unravel a novel molecular mechanism and immune functions for TAM and 4HT, sustaining their repurposing in infective and other estrogen receptors-unrelated pathologies.
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Affiliation(s)
- Giovanna Pepe
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
| | - Chiara Sfogliarini
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
| | - Loris Rizzello
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy; National Institute of Molecular Genetics (INGM) Milan, 20122 Milan, Italy
| | - Giuseppe Battaglia
- Department of Chemistry and; The EPSRC/Jeol Centre for Liquid Phase Electron Microscopy, University College London, WC1H 0AJ London, U.K; Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain; Institute for Physics of Living System, University College London, WC1E 6BT London, U.K; Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
| | - Christian Pinna
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
| | - Gianenrico Rovati
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
| | - Paolo Ciana
- Department of Health Sciences University of Milan, 20142 Milan, Italy
| | - Electra Brunialti
- Department of Health Sciences University of Milan, 20142 Milan, Italy
| | - Federica Mornata
- IRCCS Humanitas Research Hospital, via Manzoni 56, 20089 Rozzano, Milan, Italy
| | - Adriana Maggi
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy
| | - Massimo Locati
- IRCCS Humanitas Research Hospital, via Manzoni 56, 20089 Rozzano, Milan, Italy; Department of Medical Biotechnologies and Translational Medicine, University of Milan, 20133 Milan, Italy
| | - Elisabetta Vegeto
- Department of Pharmaceutical Sciences, University of Milan, 20133 Milan, Italy.
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21
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Butler JM, Maruska KP. Opsin Expression Varies with Reproductive State in the Cichlid Fish Astatotilapia burtoni. Integr Comp Biol 2021; 61:240-248. [PMID: 33972997 DOI: 10.1093/icb/icab058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Animals use visual communication to convey crucial information about their identity, reproductive status, and sex. Plasticity in the auditory and olfactory systems has been well-documented, however, fewer studies have tested for plasticity in the visual system, a surprising detail since courtship and mate choice are largely dependent on visual signals across taxa. We previously found reproductive state-dependent plasticity in the eye of the highly social cichlid fish Astatotilapia burtoni. Male A. burtoni increase their courtship, including multicomponent visual displays, when around ovulated females, and ovulated females are more responsive to male visual courtship displays than non-ovulated females. Based on this, we hypothesized that ovulation status impacts visual capabilities in A. burtoni females. Using electroretinograms, we found that ovulated females had greater visual sensitivity at wavelengths corresponding to male courtship coloration compared with non-reproductively-receptive females. In addition, ovulated females had higher neural activation in the retina and higher mRNA expression levels of neuromodulatory receptors (e.g., sex-steroids; gonadotropins) in the eye than non-ovulated females. Here, we add to this body of work by testing the hypothesis that cone opsin expression changes with female reproductive state. Ovulated females had higher expression of short wavelength sensitive opsins (sws1, sws2a, sws2b) compared with mouthbrooding females. Further, expression of sws2a, the most abundant opsin in the A. burtoni eye, positively correlated with levels of circulating 11-ketotestosterone and estradiol and estrogen, androgen, and gonadotropin system receptor expression in the eye in females. These data indicate that reproductive state-dependent plasticity also occurs at the level of photoreceptors, not just through modulation of visual signals at downstream retinal layers. Collectively, these data provide crucial evidence linking endocrine modulation of visual plasticity to mate choice behaviors in females.
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Affiliation(s)
- Julie M Butler
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA.,Department of Biology, Stanford University, 304 Gilbert, 371 Jane Stanford Way, Stanford, CA 94305, USA
| | - Karen P Maruska
- Department of Biological Sciences, Louisiana State University, 202 Life Sciences Bldg, Baton Rouge, LA 70803, USA
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22
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Guo M, Schwartz TD, Dunaief JL, Cui QN. Myeloid cells in retinal and brain degeneration. FEBS J 2021; 289:2337-2361. [PMID: 34478598 PMCID: PMC8891394 DOI: 10.1111/febs.16177] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 08/06/2021] [Accepted: 09/02/2021] [Indexed: 12/11/2022]
Abstract
Retinal inflammation underlies multiple prevalent ocular and neurological diseases. Similar inflammatory processes are observed in glaucomatous optic neuropathy, age-related macular degeneration, retinitis pigmentosa, posterior uveitis, Alzheimer's disease, and Parkinson's disease. In particular, human and animal studies have demonstrated the important role microglia/macrophages play in initiating and maintaining a pro-inflammatory environment in degenerative processes impacting vision. On the other hand, microglia have also been shown to have a protective role in multiple central nervous system diseases. Identifying the mechanisms underlying cell dysfunction and death is the first step toward developing novel therapeutics for these diseases impacting the central nervous system. In addition to reviewing recent key studies defining important mediators of retinal inflammation, with an emphasis on translational studies that bridge this research from bench to bedside, we also highlight a promising therapeutic class of medications, the glucagon-like peptide-1 receptor agonists. Finally, we propose areas where additional research is necessary to identify mechanisms that can be modulated to shift the balance from a neurotoxic to a neuroprotective retinal environment.
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Affiliation(s)
- Michelle Guo
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Turner D Schwartz
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Joshua L Dunaief
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Qi N Cui
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
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23
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Berkowitz BA, Podolsky RH, Childers KL, Roche SL, Cotter TG, Graffice E, Harp L, Sinan K, Berri AM, Schneider M, Qian H, Gao S, Roberts R. Rod Photoreceptor Neuroprotection in Dark-Reared Pde6brd10 Mice. Invest Ophthalmol Vis Sci 2021; 61:14. [PMID: 33156341 PMCID: PMC7671864 DOI: 10.1167/iovs.61.13.14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Purpose The purpose of this study was to test the hypothesis that anti-oxidant and / or anti-inflammation drugs that suppress rod death in cyclic light-reared Pde6brd10 mice are also effective in dark-reared Pde6brd10 mice. Methods In untreated dark-reared Pde6brd10 mice at post-natal (P) days 23 to 24, we measured the outer nuclear layer (ONL) thickness (histology) and dark-light thickness difference in external limiting membrane-retinal pigment epithelium (ELM-RPE) (optical coherence tomography [OCT]), retina layer oxidative stress (QUEnch-assiSTed [QUEST] magnetic resonance imaging [MRI]); and microglia/macrophage-driven inflammation (immunohistology). In dark-reared P50 Pde6brd10 mice, ONL thickness was measured (OCT) in groups given normal chow or chow admixed with methylene blue (MB) + Norgestrel (anti-oxidant, anti-inflammatory), or MB or Norgestrel separately. Results P24 Pde6brd10 mice showed no significant dark-light ELM-RPE response in superior and inferior retina consistent with high cGMP levels. Norgestrel did not significantly suppress the oxidative stress of Pde6brd10 mice that is only found in superior central outer retina of males at P23. Overt rod degeneration with microglia/macrophage activation was observed but only in the far peripheral superior retina in male and female P23 Pde6brd10 mice. Significant rod protection was measured in female P50 Pde6brd10 mice given 5 mg/kg/day MB + Norgestrel diet; no significant benefit was seen with MB chow or Norgestrel chow alone, nor in similarly treated male mice. Conclusions In early rod degeneration in dark-reared Pde6brd10 mice, little evidence is found in central retina for spatial associations among biomarkers of the PDE6B mutation, oxidative stress, and rod death; neuroprotection at P50 was limited to a combination of anti-oxidant/anti-inflammation treatment in a sex-specific manner.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Sarah L Roche
- Cell Development and Disease Laboratory, Biochemistry Department, Biosciences Institute, University College Cork, Cork, Ireland
| | - Thomas G Cotter
- Cell Development and Disease Laboratory, Biochemistry Department, Biosciences Institute, University College Cork, Cork, Ireland
| | - Emma Graffice
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Lamis Harp
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Kenan Sinan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ali M Berri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Michael Schneider
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Shasha Gao
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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24
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Yang P, Lockard R, Titus H, Hiblar J, Weller K, Wafai D, Weleber RG, Duvoisin RM, Morgans CW, Pennesi ME. Suppression of cGMP-Dependent Photoreceptor Cytotoxicity With Mycophenolate Is Neuroprotective in Murine Models of Retinitis Pigmentosa. Invest Ophthalmol Vis Sci 2021; 61:25. [PMID: 32785677 PMCID: PMC7441375 DOI: 10.1167/iovs.61.10.25] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Purpose To determine the effect of mycophenolate mofetil (MMF) on retinal degeneration on two mouse models of retinitis pigmentosa. Methods Intraperitoneal injections of MMF were administered daily in rd10 and c57 mice starting at postoperative day 12 (P12) and rd1 mice starting at P8. The effect of MMF was assessed with optical coherence tomography, immunohistochemistry, electroretinography, and OptoMotry. Whole retinal cyclic guanosine monophosphate (cGMP) and mycophenolic acid levels were quantified with mass spectrometry. Photoreceptor cGMP cytotoxicity was evaluated with cell counts of cGMP immunostaining. Results MMF treatment significantly delays the onset of retinal degeneration and cGMP-dependent photoreceptor cytotoxicity in rd10 and rd1 mice, albeit a more modest effect in the latter. In rd10 mice, treatment with MMF showed robust preservation of the photoreceptors up to P22 with associated suppression of cGMP immunostaining and microglial activation; The neuroprotective effect diminished after P22, but outer retinal thickness was still significantly thicker by P35 and OptoMotry response was significantly better up to P60. Whereas cGMP immunostaining of the photoreceptors were present in rd10 and rd1 mice, hyperphysiological whole retinal cGMP levels were observed only in rd1 mice. Conclusions Early treatment with MMF confers potent neuroprotection in two animal models of RP by suppressing the cGMP-dependent common pathway for photoreceptor cell death. The neuroprotective effect of MMF on cGMP-dependent cytotoxicity occurs independently of the presence of hyperphysiological whole retinal cGMP levels. Thus our data suggest that MMF may be an important new class of neuroprotective agent that could be useful in the treatment of patients with RP.
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Affiliation(s)
- Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Rachel Lockard
- School of Medicine, Oregon Health & Science University, Portland, Oregon, United States
| | - Hope Titus
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Jordan Hiblar
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Kyle Weller
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Dahlia Wafai
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Richard G Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Robert M Duvoisin
- Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, Oregon, United States
| | - Catherine W Morgans
- Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, Oregon, United States
| | - Mark E Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
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25
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An efficient inducible RPE-Selective cre transgenic mouse line. Exp Eye Res 2020; 202:108370. [PMID: 33264655 DOI: 10.1016/j.exer.2020.108370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/30/2020] [Accepted: 11/20/2020] [Indexed: 12/22/2022]
Abstract
Cre-mediated modulation of gene function in the murine retinal pigment epithelium (RPE) has been widely used, but current postnatal RPE-selective Cre driver lines suffer from limited recombination efficiency and/or ectopic or mosaic expression. We sought to generate a transgenic mouse line with consistently efficient RPE-selective Cre activity that could be temporally regulated. We used ϕC31 integrase to insert a DNA construct encoding a human BEST1 promoter fragment driving a Cre recombinase estrogen receptor fusion (BEST1-CreERT2) at the Rosa26 locus of C57BL/6J mice. Rosa26BEST1-CreERT2 mice were bred with a tdTomato reporter line and to mice with a Cre-conditional allele of Tfam. 4-hydroxytamoxifen or vehicle was delivered by four consecutive daily intraperitoneal injections. TdTomato was robustly expressed in the RPE of mice of both sexes for inductions beginning at P14 (males 90.7 ± 4.5%, females 84.7 ± 3.2%) and at 7 weeks (males 84.3 ± 7.0%, females 82 ± 3.6%). <0.6% of Muller glia also expressed tdTomato, but no tdTomato fluorescence was observed in other ocular cells or in multiple non-ocular tissues, with the exception of sparse foci in the testis. No evidence of retinal toxicity was observed in mice homozygous for the transgene induced beginning at P14 and assessed at 7-10 months. RPE-selective ablation of Tfam beginning at P14 led to reduced retinal thickness at 8 months of age and diminished retinal electrical responses at 12 months, as expected. These findings demonstrate that we have generated a mouse line with consistently efficient, tamoxifen-mediated postnatal induction of Cre recombination in the RPE and a small fraction of Muller glia. This line should be useful for temporally regulated modulation of gene function in the murine RPE.
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26
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Miron VE, Priller J. Investigating Microglia in Health and Disease: Challenges and Opportunities. Trends Immunol 2020; 41:785-793. [PMID: 32736967 DOI: 10.1016/j.it.2020.07.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 12/24/2022]
Abstract
Microglia are tissue-resident macrophages implicated in central nervous system (CNS) development, homeostasis, and response to injury. Recent advances in transcriptomics, multiplex protein expression analysis, and experimental depletion of microglia have cemented their importance. However, it is still unclear which models are best suited to investigate microglia and explore their function in human disease. Here, we discuss issues regarding off-targeting during experimental manipulation, and differences and similarities between human and rodent microglia. With new developments in transgenic lines and human-rodent chimeras, we anticipate that in coming years, a clearer picture of microglia function in health and disease will emerge.
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Affiliation(s)
- Veronique E Miron
- Medical Research Council Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, UK.
| | - Josef Priller
- Department of Neuropsychiatry and Laboratory of Molecular Psychiatry, Charité - Universitätsmedizin Berlin and DZNE, Berlin, Germany; UK Dementia Research Institute, The University of Edinburgh, Edinburgh, UK
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27
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Lew DS, Mazzoni F, Finnemann SC. Microglia Inhibition Delays Retinal Degeneration Due to MerTK Phagocytosis Receptor Deficiency. Front Immunol 2020; 11:1463. [PMID: 32765507 PMCID: PMC7381113 DOI: 10.3389/fimmu.2020.01463] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 06/05/2020] [Indexed: 12/19/2022] Open
Abstract
Retinitis Pigmentosa (RP) is a group of inherited retinal diseases characterized by progressive loss of rod followed by cone photoreceptors. An especially early onset form of RP with blindness in teenage years is caused by mutations in mertk, the gene encoding the clearance phagocytosis receptor Mer tyrosine kinase (MerTK). The cause for blindness in mutant MerTK-associated RP (mutMerTK-RP) is the failure of retinal pigment epithelial cells in diurnal phagocytosis of spent photoreceptor outer segment debris. However, the early onset and very fast progression of degeneration in mutMerTK-RP remains unexplained. Here, we explored the role of microglia in the Royal College of Surgeons (RCS) rat model of mutMerTK-RP. We found elevated levels of inflammatory cytokines and CD68 microglia activation marker, and more ionized calcium-binding adapter molecule 1 (Iba-1) positive microglia in RCS retina when compared to wild-type retina as early as postnatal day 14 (P14). Strikingly, renewal of photoreceptor outer segments in P14 wild-type rat retina is still immature with low levels of RPE phagocytosis implying that at this early age lack of this process in RCS rats is unlikely to distress photoreceptors. Although the total number of Iba-1 positive retinal microglia remains constant from P14 to P30, we observed increasing numbers of microglia in the outer retina from P20 implying migration to the outer retina before onset of photoreceptor cell death at ~P25. Iba-1 and CD68 levels also increase in the retina during this time period suggesting microglia activation. To determine whether microglia affect the degenerative process, we suppressed retinal microglia in vivo using tamoxifen or a combination of tamoxifen and liposomal clodronate. Treatments partly prevented elevation of Iba-1 and CD68 and relocalization of microglia. Moreover, treatments led to partial but significant retention of photoreceptor viability and photoreceptor function. We conclude that loss of the phagocytosis receptor MerTK causes microglia activation and relocalization in the retina before lack of RPE phagocytosis causes overt retinal degeneration, and that microglia activities accelerate loss of photoreceptors in mutMerTK-RP. These results suggest that therapies targeting microglia may delay onset and slow the progression of this blinding disease.
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Affiliation(s)
- Deborah S Lew
- Department of Biological Sciences, Center for Cancer, Genetic Diseases and Gene Regulation, Fordham University, Bronx, NY, United States
| | - Francesca Mazzoni
- Department of Biological Sciences, Center for Cancer, Genetic Diseases and Gene Regulation, Fordham University, Bronx, NY, United States
| | - Silvia C Finnemann
- Department of Biological Sciences, Center for Cancer, Genetic Diseases and Gene Regulation, Fordham University, Bronx, NY, United States
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28
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Palazzo I, Deistler K, Hoang TV, Blackshaw S, Fischer AJ. NF-κB signaling regulates the formation of proliferating Müller glia-derived progenitor cells in the avian retina. Development 2020; 147:dev.183418. [PMID: 32291273 DOI: 10.1242/dev.183418] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022]
Abstract
Retinal regeneration is robust in some cold-blooded vertebrates, but this process is ineffective in warm-blooded vertebrates. Understanding the mechanisms that suppress the reprogramming of Müller glia into neurogenic progenitors is key to harnessing the regenerative potential of the retina. Inflammation and reactive microglia are known to influence the formation of Müller glia-derived progenitor cells (MGPCs), but the mechanisms underlying this interaction are unknown. We used a chick in vivo model to investigate nuclear factor kappa B (NF-κB) signaling, a critical regulator of inflammation, during the reprogramming of Müller glia into proliferating progenitors. We find that components of the NF-κB pathway are dynamically regulated by Müller glia after neuronal damage or treatment with growth factors. Inhibition of NF-κB enhances, whereas activation suppresses, the formation of proliferating MGPCs. Following microglia ablation, the effects of NF-κB-agonists on MGPC-formation are reversed, suggesting that signals provided by reactive microglia influence how NF-κB impacts Müller glia reprogramming. We propose that NF-κB is an important signaling 'hub' that suppresses the reprogramming of Müller glia into proliferating MGPCs and this 'hub' coordinates signals provided by reactive microglia.
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Affiliation(s)
- Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Kyle Deistler
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
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29
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Yu C, Roubeix C, Sennlaub F, Saban DR. Microglia versus Monocytes: Distinct Roles in Degenerative Diseases of the Retina. Trends Neurosci 2020; 43:433-449. [PMID: 32459994 DOI: 10.1016/j.tins.2020.03.012] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/27/2020] [Accepted: 03/25/2020] [Indexed: 01/22/2023]
Abstract
Unlike in the healthy mammalian retina, macrophages in retinal degenerative states are not solely comprised of microglia but may include monocyte-derived recruits. Recent studies have applied transgenics, lineage-tracing, and transcriptomics to help decipher the distinct roles of these two cell types in the diseasesettings of inherited retinal degenerations and age-related macular degeneration.Literature discussed here focuses on the ectopic presence of both macrophage types in the extracellular site surrounding the outer aspect ofphotoreceptor cells (i.e.,the subretinal space), which is crucially involved in the pathobiology. From these studies we propose a working model in which perturbed photoreceptor states cause microglial dominant migration to the subretinal space as a protective response, whereas the abundant presence ofmonocyte-derived cells there instead drives and accelerates pathology. The latter, we propose, is underpinned by specific genetic and nongenetic determinants that lead to a maladaptive macrophage state.
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Affiliation(s)
- Chen Yu
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA
| | - Christophe Roubeix
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France
| | - Florian Sennlaub
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, F-75012 Paris, France.
| | - Daniel R Saban
- Department of Ophthalmology, Duke University, Durham, NC 27710, USA; Department of Immunology, Duke University,Durham, NC 27710, USA.
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30
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Sundar JC, Munezero D, Bryan-Haring C, Saravanan T, Jacques A, Ramamurthy V. Rhodopsin signaling mediates light-induced photoreceptor cell death in rd10 mice through a transducin-independent mechanism. Hum Mol Genet 2020; 29:394-406. [PMID: 31925423 PMCID: PMC7015845 DOI: 10.1093/hmg/ddz299] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/22/2019] [Accepted: 12/02/2019] [Indexed: 01/08/2023] Open
Abstract
Retinitis pigmentosa (RP) is a debilitating blinding disease affecting over 1.5 million people worldwide, but the mechanisms underlying this disease are not well understood. One of the common models used to study RP is the retinal degeneration-10 (rd10) mouse, which has a mutation in Phosphodiesterase-6b (Pde6b) that causes a phenotype mimicking the human disease. In rd10 mice, photoreceptor cell death occurs with exposure to normal light conditions, but as demonstrated in this study, rearing these mice in dark preserves their retinal function. We found that inactivating rhodopsin signaling protected photoreceptors from degeneration suggesting that the pathway activated by this G-protein-coupled receptor is causing light-induced photoreceptor cell death in rd10 mice. However, inhibition of transducin signaling did not prevent the loss of photoreceptors in rd10 mice reared under normal light conditions implying that the degeneration caused by rhodopsin signaling is not mediated through its canonical G-protein transducin. Inexplicably, loss of transducin in rd10 mice also led to photoreceptor cell death in darkness. Furthermore, we found that the rd10 mutation in Pde6b led to a reduction in the assembled PDE6αβγ2 complex, which was corroborated by our data showing mislocalization of the γ subunit. Based on our findings and previous studies, we propose a model where light activates a non-canonical pathway mediated by rhodopsin but independent of transducin that sensitizes cyclic nucleotide gated channels to cGMP and causes photoreceptor cell death. These results generate exciting possibilities for treatment of RP patients without affecting their vision or the canonical phototransduction cascade.
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Affiliation(s)
- Jesse C Sundar
- Departments of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Daniella Munezero
- Departments of Ophthalmology and Visual Sciences, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Caitlyn Bryan-Haring
- Departments of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Thamaraiselvi Saravanan
- Departments of Ophthalmology and Visual Sciences, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Angelica Jacques
- Departments of Ophthalmology and Visual Sciences, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
| | - Visvanathan Ramamurthy
- Departments of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
- Departments of Ophthalmology and Visual Sciences, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
- Departments of Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26505, USA
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31
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Tamoxifen promotes white matter recovery and cognitive functions in male mice after chronic hypoperfusion. Neurochem Int 2019; 131:104566. [PMID: 31593788 DOI: 10.1016/j.neuint.2019.104566] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 12/18/2022]
Abstract
Cerebral white matter lesions (WMLs) induced by chronic cerebral hypoperfusion are one of the major components of stroke pathology and closely associated with cognitive impairment. However, the repair and related pathophysiology of white matter after brain injury remains relatively elusive and underexplored. Successful neuroregeneration is a method for the potential treatment of central nervous system (CNS) disorders. A non-steroidal estrogen receptor modulator, Tamoxifen, is an effective inhibitor of cell-swelling-activated anion channels and can mimic neuroprotective effects of estrogen in experimental ischemic stroke. However, its remains unclear whether Tamoxifen has beneficial effects in the pathological process after WMLs. In the present study, we investigated the efficacy of Tamoxifen on multiple elements of oligovascular niche of the male C57BL/6 mice brain after bilateral carotid artery stenosis (BCAS) - induced WMLs. Tamoxifen was injected intraperitoneally once daily from 1 day after BCAS until 1 day before sacrificed. Following chronic hypoperfusion, BCAS mice presented white matter demyelination, loss of axon-glia integrity, activated inflammatory response, and cognitive impairments. Tamoxifen treatment significantly facilitated functional restoration of working memory impairment in mice after white matter injury, thus indicating a translational potential for this estrogen receptor modulator given its clinical safety and applicability for WMLs, which lack of currently available treatments. Furthermore, Tamoxifen treatment reduced microglia activation and inflammatory response, favored microglial polarization toward to the M2 phenotype, enhanced oligodendrocyte precursor cells proliferation and differentiation, and promoted remyelination after chronic hypoperfusion. Together, our data indicate that Tamoxifen could alleviate white matter injury and play multiple targets protective effects following chronic hypoperfusion, which is a promising candidate for the therapeutic target for ischemic WMLs and other demyelination diseases associated cognitive impairment.
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32
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Activation of Rod Input in a Model of Retinal Degeneration Reverses Retinal Remodeling and Induces Formation of Functional Synapses and Recovery of Visual Signaling in the Adult Retina. J Neurosci 2019; 39:6798-6810. [PMID: 31285302 DOI: 10.1523/jneurosci.2902-18.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 05/28/2019] [Accepted: 06/18/2019] [Indexed: 12/31/2022] Open
Abstract
A major cause of human blindness is the death of rod photoreceptors. As rods degenerate, synaptic structures between rod and rod bipolar cells disappear and the rod bipolar cells extend their dendrites and occasionally make aberrant contacts. Such changes are broadly observed in blinding disorders caused by photoreceptor cell death and are thought to occur in response to deafferentation. How the remodeled retinal circuit affects visual processing following rod rescue is not known. To address this question, we generated male and female transgenic mice wherein a disrupted cGMP-gated channel (CNG) gene can be repaired at the endogenous locus and at different stages of degeneration by tamoxifen-inducible cre-mediated recombination. In normal rods, light-induced closure of CNG channels leads to hyperpolarization of the cell, reducing neurotransmitter release at the synapse. Similarly, rods lacking CNG channels exhibit a resting membrane potential that was ~10 mV hyperpolarized compared to WT rods, indicating diminished glutamate release. Retinas from these mice undergo stereotypic retinal remodeling as a consequence of rod malfunction and degeneration. Upon tamoxifen-induced expression of CNG channels, rods recovered their structure and exhibited normal light responses. Moreover, we show that the adult mouse retina displays a surprising degree of plasticity upon activation of rod input. Wayward bipolar cell dendrites establish contact with rods to support normal synaptic transmission, which is propagated to the retinal ganglion cells. These findings demonstrate remarkable plasticity extending beyond the developmental period and support efforts to repair or replace defective rods in patients blinded by rod degeneration.SIGNIFICANCE STATEMENT Current strategies for treatment of neurodegenerative disorders are focused on the repair of the primary affected cell type. However, the defective neurons function within a complex neural circuitry, which also becomes degraded during disease. It is not known whether rescued neurons and the remodeled circuit will establish communication to regain normal function. We show that the adult mammalian neural retina exhibits a surprising degree of plasticity following rescue of rod photoreceptors. The wayward dendrites of rod bipolar cells re-establish contact with rods to support normal synaptic transmission, which is propagated to the retinal ganglion cells. These findings support efforts to repair or replace defective rods in patients blinded by rod cell loss.
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Todd L, Palazzo I, Suarez L, Liu X, Volkov L, Hoang TV, Campbell WA, Blackshaw S, Quan N, Fischer AJ. Reactive microglia and IL1β/IL-1R1-signaling mediate neuroprotection in excitotoxin-damaged mouse retina. J Neuroinflammation 2019; 16:118. [PMID: 31170999 PMCID: PMC6555727 DOI: 10.1186/s12974-019-1505-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 05/09/2019] [Indexed: 12/12/2022] Open
Abstract
Background Microglia and inflammation have context-specific impacts upon neuronal survival in different models of central nervous system (CNS) disease. Herein, we investigate how inflammatory mediators, including microglia, interleukin 1 beta (IL1β), and signaling through interleukin 1 receptor type 1 (IL-1R1), influence the survival of retinal neurons in response to excitotoxic damage. Methods Excitotoxic retinal damage was induced via intraocular injections of NMDA. Microglial phenotype and neuronal survival were assessed by immunohistochemistry. Single-cell RNA sequencing was performed to obtain transcriptomic profiles. Microglia were ablated by using clodronate liposome or PLX5622. Retinas were treated with IL1β prior to NMDA damage and cell death was assessed in wild type, IL-1R1 null mice, and mice expressing IL-1R1 only in astrocytes. Results NMDA-induced damage included neuronal cell death, microglial reactivity, upregulation of pro-inflammatory cytokines, and genes associated with IL1β-signaling in different types of retinal neurons and glia. Expression of the IL1β receptor, IL-1R1, was evident in astrocytes, endothelial cells, some Müller glia, and OFF bipolar cells. Ablation of microglia with clodronate liposomes or Csf1r antagonist (PLX5622) resulted in elevated cell death and diminished neuronal survival in excitotoxin-damaged retinas. Exogenous IL1β stimulated the proliferation and reactivity of microglia in the absence of damage, reduced numbers of dying cells in damaged retinas, and increased neuronal survival following an insult. IL1β failed to provide neuroprotection in the IL-1R1-null retina, but IL1β-mediated neuroprotection was rescued when expression of IL-1R1 was restored in astrocytes. Conclusions We conclude that reactive microglia provide protection to retinal neurons, since the absence of microglia is detrimental to survival. We propose that, at least in part, the survival-influencing effects of microglia may be mediated by IL1β, IL-1R1, and interactions of microglia and other macroglia. Electronic supplementary material The online version of this article (10.1186/s12974-019-1505-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Levi Todd
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Isabella Palazzo
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA
| | - Lilianna Suarez
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA
| | - Xiaoyu Liu
- Institute for Behavioral Medicine Research, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Leo Volkov
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Warren A Campbell
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ning Quan
- Institute for Behavioral Medicine Research, College of Medicine, The Ohio State University, Columbus, OH, USA.,Division of Biosciences, College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Andy J Fischer
- Department of Neuroscience, College of Medicine, The Ohio State University, 3020 Graves Hall, 333 W. 10th Ave, Columbus, OH, 43210-1239, USA.
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Estrogenic Regulation of Neuroprotective and Neuroinflammatory Mechanisms: Implications for Depression and Cognition. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/978-3-030-11355-1_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Getter T, Suh S, Hoang T, Handa JT, Dong Z, Ma X, Chen Y, Blackshaw S, Palczewski K. The selective estrogen receptor modulator raloxifene mitigates the effect of all- trans-retinal toxicity in photoreceptor degeneration. J Biol Chem 2019; 294:9461-9475. [PMID: 31073029 DOI: 10.1074/jbc.ra119.008697] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/08/2019] [Indexed: 12/19/2022] Open
Abstract
The retinoid cycle is a metabolic process in the vertebrate retina that continuously regenerates 11-cis-retinal (11-cisRAL) from the all-trans-retinal (atRAL) isomer. atRAL accumulation can cause photoreceptor degeneration and irreversible visual dysfunction associated with incurable blinding retinal diseases, such as Stargardt disease, retinitis pigmentosa (RP), and atrophic age-related macular degeneration (AMD). The underlying cellular mechanisms leading to retinal degeneration remain uncertain, although previous studies have shown that atRAL promotes calcium influx associated with cell apoptosis. To identify compounds that mitigate the effects of atRAL toxicity, here we developed an unbiased and robust image-based assay that can detect changes in intracellular calcium levels in U2OS cells. Using our assay in a high-throughput screen of 2,400 compounds, we noted that selective estrogen receptor modulators (SERMs) potently stabilize intracellular calcium and thereby counteract atRAL-induced toxicity. In a light-induced retinal degeneration mouse model (Abca4 -/- Rdh8 -/-), raloxifene (a benzothiophene-type scaffold SERM) prevented the onset of photoreceptor apoptosis and thus protected the retina from degeneration. The minor structural differences between raloxifene and one of its derivatives (Y 134) had a major impact on calcium homeostasis after atRAL exposure in vitro, and we verified this differential impact in vivo In summary, the SERM raloxifene has structural and functional neuroprotective effects in the retina. We propose that the highly sensitive image-based assay developed here could be applied for the discovery of additional drug candidates preventing photoreceptor degeneration.
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Affiliation(s)
- Tamar Getter
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697, .,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Susie Suh
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697.,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Thanh Hoang
- the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - James T Handa
- the Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | | | - Xiuli Ma
- Polgenix Inc., Irvine, California 92617
| | - Yuanyuan Chen
- the Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, and.,the McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Seth Blackshaw
- the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Krzysztof Palczewski
- From the Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, California 92697, .,the Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106
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He J, Zhao C, Dai J, Weng CH, Bian BSJ, Gong Y, Ge L, Fang Y, Liu H, Xu H, Yin ZQ. Microglia Mediate Synaptic Material Clearance at the Early Stage of Rats With Retinitis Pigmentosa. Front Immunol 2019; 10:912. [PMID: 31105708 PMCID: PMC6499027 DOI: 10.3389/fimmu.2019.00912] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/09/2019] [Indexed: 12/11/2022] Open
Abstract
Resident microglia are the main immune cells in the retina and play a key role in the pathogenesis of retinitis pigmentosa (RP). Many previous studies on the roles of microglia mainly focused on the neurotoxicity or neuroprotection of photoreceptors, while their contributions to synaptic remodeling of neuronal circuits in the retina of early RP remained unclarified. In the present study, we used Royal College of Surgeons (RCS) rats, a classic RP model characterized by progressive microglia activation and synapse loss, to investigate the constitutive effects of microglia on the synaptic lesions and ectopic neuritogenesis. Rod degeneration resulted in synapse disruption and loss in the outer plexiform layer (OPL) at the early stage of RP. Coincidentally, the resident microglia in the OPL increased phagocytosis and mainly engaged in phagocytic engulfment of postsynaptic mGluR6 of rod bipolar cells (RBCs). Complement pathway might be involved in clearance of postsynaptic elements of RBCs by microglia. We pharmacologically deleted microglia using a CSF1 receptor (CSF1R) inhibitor to confirm this finding, and found that it caused the accumulation of postsynaptic mGluR6 levels and increased the number and length of ectopic dendrites in the RBCs. Interestingly, the numbers of presynaptic sites expressing CtBP2 and colocalized puncta in the OPL of RCS rats were not affected by microglia elimination. However, sustained microglial depletion led to progressive functional deterioration in the retinal responses to light in RCS rats. Based on our results, microglia mediated the remodeling of RBCs by phagocytosing postsynaptic materials and inhibiting ectopic neuritogenesis, contributing to delay the deterioration of vision at the early stage of RP.
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Affiliation(s)
- Juncai He
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Congjian Zhao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Jiaman Dai
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Chuan Huang Weng
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Bai Shi Jiao Bian
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yu Gong
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Lingling Ge
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yajie Fang
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Hui Liu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Haiwei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Zheng Qin Yin
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Amy Medical University), Chongqing, China.,Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
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Li Y, Furhang R, Ray A, Duncan T, Soucy J, Mahdi R, Chaitankar V, Gieser L, Poliakov E, Qian H, Liu P, Dong L, Rogozin IB, Redmond TM. Aberrant RNA splicing is the major pathogenic effect in a knock-in mouse model of the dominantly inherited c.1430A>G human RPE65 mutation. Hum Mutat 2019; 40:426-443. [PMID: 30628748 DOI: 10.1002/humu.23706] [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: 07/31/2018] [Revised: 12/14/2018] [Accepted: 01/06/2019] [Indexed: 01/03/2023]
Abstract
Human RPE65 mutations cause a spectrum of retinal dystrophies that result in blindness. While RPE65 mutations have been almost invariably recessively inherited, a c.1430A>G (p.(D477G)) mutation has been reported to cause autosomal dominant retinitis pigmentosa (adRP). To study the pathogenesis of this human mutation, we have replicated the mutation in a knock-in (KI) mouse model using CRISPR/Cas9-mediated genome editing. Significantly, in contrast to human patients, heterozygous KI mice do not exhibit any phenotypes in visual function tests. When raised in regular vivarium conditions, homozygous KI mice display relatively undisturbed visual functions with minimal retinal structural changes. However, KI/KI mouse retinae are more sensitive to light exposure and exhibit signs of degenerative features when subjected to light stress. We find that instead of merely producing a missense mutant protein, the A>G nucleotide substitution greatly affects appropriate splicing of Rpe65 mRNA by generating an ectopic splice site in comparable context to the canonical one, thereby disrupting RPE65 protein expression. Similar splicing defects were also confirmed for the human RPE65 c.1430G mutant in an in vitro Exontrap assay. Our data demonstrate that a splicing defect is associated with c.1430G pathogenesis, and therefore provide insights in the therapeutic strategy for human patients.
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Affiliation(s)
- Yan Li
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Rachel Furhang
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Amanda Ray
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Todd Duncan
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Joseph Soucy
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Rashid Mahdi
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Vijender Chaitankar
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, Maryland
| | - Linn Gieser
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, Maryland
| | - Eugenia Poliakov
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
| | - Haohua Qian
- Visual Function Core, National Eye Institute, NIH, Bethesda, Maryland
| | - Pinghu Liu
- Genetic Engineering Core, National Eye Institute, NIH, Bethesda, Maryland
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, NIH, Bethesda, Maryland
| | - Igor B Rogozin
- National Center for Biotechnology Information, National Library of Medicine, NIH, Bethesda, Maryland
| | - T Michael Redmond
- Laboratory of Retinal Cell & Molecular Biology, National Eye Institute, NIH, Bethesda, Maryland
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McMenamin PG, Saban DR, Dando SJ. Immune cells in the retina and choroid: Two different tissue environments that require different defenses and surveillance. Prog Retin Eye Res 2018; 70:85-98. [PMID: 30552975 DOI: 10.1016/j.preteyeres.2018.12.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 12/03/2018] [Accepted: 12/11/2018] [Indexed: 01/04/2023]
Abstract
In the eye immune defenses must take place in a plethora of differing microenvironments ranging from the corneal and conjunctival epithelia facing the external environment to the pigmented connective tissue of the uveal tract containing smooth muscle, blood vessels and peripheral nerves to the innermost and highly protected neural retina. The extravascular environment of the neural retina, like the brain parenchyma, is stringently controlled to maintain conditions required for neural transmission. The unique physiological nature of the neural retina can be attributed to the blood retinal barriers (BRB) of the retinal vasculature and the retinal pigment epithelium, which both tightly regulate the transport of small molecules and restrict passage of cells and macromolecules from the circulation into the retina in a similar fashion to the blood brain barrier (BBB). The extracellular environment of the neural retina differs markedly from that of the highly vascular, loose connective tissue of the choroid, which lies outside the BRB. The choroid hosts a variety of immune cell types, including macrophages, dendritic cells (DCs) and mast cells. This is in marked contrast to the neural parenchyma of the retina, which is populated almost solely by microglia. This review will describe the current understanding of the distribution, phenotype and physiological role of ocular immune cells behind or inside the blood-retinal barriers and those in closely juxtaposed tissues outside the barrier. The nature and function of these immune cells can profoundly influence retinal homeostasis and lead to disordered immune function that can lead to vision loss.
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Affiliation(s)
- Paul G McMenamin
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.
| | - Daniel R Saban
- Department of Ophthalmology, Department of Immunology, Duke University School of Medicine, Durham, NC, USA
| | - Samantha J Dando
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
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Abstract
Microglia, the primary resident immune cell type, constitute a key population of glia in the retina. Recent evidence indicates that microglia play significant functional roles in the retina at different life stages. During development, retinal microglia regulate neuronal survival by exerting trophic influences and influencing programmed cell death. During adulthood, ramified microglia in the plexiform layers interact closely with synapses to maintain synaptic structure and function that underlie the retina's electrophysiological response to light. Under pathological conditions, retinal microglia participate in potentiating neurodegeneration in diseases such as glaucoma, retinitis pigmentosa, and age-related neurodegeneration by producing proinflammatory neurotoxic cytokines and removing living neurons via phagocytosis. Modulation of pathogenic microglial activation states and effector mechanisms has been linked to neuroprotection in animal models of retinal diseases. These findings have led to the design of early proof-of-concept clinical trials with microglial modulation as a therapeutic strategy.
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Affiliation(s)
- Sean M. Silverman
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;,
| | - Wai T. Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;,
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Giatti S, Garcia-Segura LM, Barreto GE, Melcangi RC. Neuroactive steroids, neurosteroidogenesis and sex. Prog Neurobiol 2018; 176:1-17. [PMID: 29981391 DOI: 10.1016/j.pneurobio.2018.06.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/25/2018] [Accepted: 06/30/2018] [Indexed: 12/12/2022]
Abstract
The nervous system is a target and a source of steroids. Neuroactive steroids are steroids that target neurons and glial cells. They include hormonal steroids originated in the peripheral glands, steroids locally synthesized by the neurons and glial cells (neurosteroids) and synthetic steroids, some of them used in clinical practice. Here we review the mechanisms of synthesis, metabolism and action of neuroactive steroids, including the role of epigenetic modifications and the mitochondria in their sex specific actions. We examine sex differences in neuroactive steroid levels under physiological conditions and their role in the establishment of sex dimorphic structures in the nervous system and sex differences in its function. In addition, particular attention is paid to neuroactive steroids under pathological conditions, analyzing how pathology alters their levels and their role as neuroprotective factors, considering the influence of sex in both cases.
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Affiliation(s)
- Silvia Giatti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Luis M Garcia-Segura
- Instituto Cajal, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
| | - Roberto C Melcangi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy.
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Damage-associated molecular pattern recognition is required for induction of retinal neuroprotective pathways in a sex-dependent manner. Sci Rep 2018; 8:9115. [PMID: 29904087 PMCID: PMC6002365 DOI: 10.1038/s41598-018-27479-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/04/2018] [Indexed: 12/29/2022] Open
Abstract
Retinal degeneration is a common cause of irreversible blindness and is caused by the death of retinal light-sensitive neurons called photoreceptors. At the onset of degeneration, stressed photoreceptors cause retinal glial cells to secrete neuroprotective factors that slow the pace of degeneration. Leukemia inhibitory factor (LIF) is one such factor that is required for endogenous neuroprotection. Photoreceptors are known to release signals of cellular stress, called damage-associated molecular patterns (DAMPs) early in degeneration, and we hypothesized that receptors for DAMPs or pattern recognition receptors (PRRs) play a key role in the induction of LIF and neuroprotective stress responses in retinal glial cells. Toll-like receptor 2 (TLR2) is a well-established DAMP receptor. In our experiments, activation of TLR2 protected both male and female mice from light damage, while the loss of TLR2 in female mice did not impact photoreceptor survival. In contrast, induction of protective stress responses, microglial phenotype and photoreceptor survival were strongly impacted in male TLR2−/− mice. Lastly, using publicly available gene expression data, we show that TLR2 is expressed highly in resting microglia prior to injury, but is also induced in Müller cells in inherited retinal degeneration.
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Zhang Y, Zhao L, Wang X, Ma W, Lazere A, Qian HH, Zhang J, Abu-Asab M, Fariss RN, Roger JE, Wong WT. Repopulating retinal microglia restore endogenous organization and function under CX3CL1-CX3CR1 regulation. SCIENCE ADVANCES 2018; 4:eaap8492. [PMID: 29750189 PMCID: PMC5943055 DOI: 10.1126/sciadv.aap8492] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 02/12/2018] [Indexed: 05/30/2023]
Abstract
Microglia have been discovered to undergo repopulation following ablation. However, the functionality of repopulated microglia and the mechanisms regulating microglia repopulation are unknown. We examined microglial homeostasis in the adult mouse retina, a specialized neural compartment containing regular arrays of microglia in discrete synaptic laminae that can be directly visualized. Using in vivo imaging and cell-fate mapping techniques, we discovered that repopulation originated from residual microglia proliferating in the central inner retina that subsequently spread by centrifugal migration to fully recapitulate pre-existing microglial distributions and morphologies. Repopulating cells fully restored microglial functions including constitutive "surveying" process movements, behavioral and physiological responses to retinal injury, and maintenance of synaptic structure and function. Microglial repopulation was regulated by CX3CL1-CX3CR1 signaling, slowing in CX3CR1 deficiency and accelerating with exogenous CX3CL1 administration. Microglial homeostasis following perturbation can fully recover microglial organization and function under the regulation of chemokine signaling between neurons and microglia.
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Affiliation(s)
- Yikui Zhang
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
- The Eye Hospital, School of Ophthalmology & Optometry, Wenzhou Medical University, Wenzhou 325027, China
| | - Lian Zhao
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xu Wang
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wenxin Ma
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Adam Lazere
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hao-hua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jun Zhang
- Synaptic Physiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mones Abu-Asab
- Section on Histopathology, 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
| | - Jerome E. Roger
- Centre d’Etude et de Recherche Thérapeutique en Ophtalmologie (CERTO), Retina France, Orsay, France
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Wai T. Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Blank T, Goldmann T, Koch M, Amann L, Schön C, Bonin M, Pang S, Prinz M, Burnet M, Wagner JE, Biel M, Michalakis S. Early Microglia Activation Precedes Photoreceptor Degeneration in a Mouse Model of CNGB1-Linked Retinitis Pigmentosa. Front Immunol 2018; 8:1930. [PMID: 29354133 PMCID: PMC5760536 DOI: 10.3389/fimmu.2017.01930] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/15/2017] [Indexed: 01/12/2023] Open
Abstract
Retinitis pigmentosa (RP) denotes a family of inherited blinding eye diseases characterized by progressive degeneration of rod and cone photoreceptors in the retina. In most cases, a rod-specific genetic defect results in early functional loss and degeneration of rods, which is followed by degeneration of cones and loss of daylight vision at later stages. Microglial cells, the immune cells of the central nervous system, are activated in retinas of RP patients and in several RP mouse models. However, it is still a matter of debate whether activated microglial cells may be responsible for the amplification of the typical degenerative processes. Here, we used Cngb1−/− mice, which represent a slow degenerative mouse model of RP, to investigate the extent of microglia activation in retinal degeneration. With a combination of FACS analysis, immunohistochemistry and gene expression analysis we established that microglia in the Cngb1−/− retina were already activated in an early, predegenerative stage of the disease. The evidence available so far suggests that early retinal microglia activation represents a first step in RP, which might initiate or accelerate photoreceptor degeneration.
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Affiliation(s)
- Thomas Blank
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tobias Goldmann
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,In Vivo Pharmacology, Synovo GmbH, Tübingen, Germany
| | - Mirja Koch
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lukas Amann
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Bonin
- Institute for Medical Genetics and Applied Genomics Transcriptomics, University of Tübingen, Tübingen, Germany.,IMGM Laboratories GmbH, Planegg, Germany
| | - Shengru Pang
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | | | - Johanna E Wagner
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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Tang PH, Pierson MJ, Heuss ND, Gregerson DS. A subpopulation of activated retinal macrophages selectively migrated to regions of cone photoreceptor stress, but had limited effect on cone death in a mouse model for type 2 Leber congenital amaurosis. Mol Cell Neurosci 2017; 85:70-81. [PMID: 28889993 DOI: 10.1016/j.mcn.2017.09.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 08/15/2017] [Accepted: 09/06/2017] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Studies of antigen presentation in retina using mice that expressed green fluorescent protein (GFP) from a transgenic CD11c promoter found that retinal GFPhi cells possessed antigen presentation function. Subsequent studies found that these high GFPhi cells preferentially localized to sites of retinal injury, consistent with their APC function. Interest in the roles of macrophages in degenerative CNS diseases led us to study the GFPhi cells in a retinal model of neurodegeneration. We asked if apoptotic cone photoreceptor cell death in Rpe65-/- knockout mice induced the GFPhi cells, explored their relationship to resident microglia (MG), and tested their role in cone survival. METHODS Rpe65-/- mice were bred to CD11cGFP mice on the B6/J background. CD11cGFPRpe65-/- mice were also backcrossed to CX3CR1YFP-creERROSADTA mice so that CX3CR1+ mononuclear cells could be depleted by Tamoxifen. Retinas were analyzed by immunohistochemistry, confocal microscopy, fluorescence fundoscopy and flow cytometry. RESULTS Elevated numbers of GFPhi cells were concentrated in photoreceptor cell layers of CD11cGFPRpe65-/- mice coinciding with the peak of cone death at 2 to 4weeks of age, and persisted for at least 14months. After the initial wave of cone loss, a slow progressive loss of cones was found that continued to retain GFPhi cells in the outer retina. Sustained, four-week Tamoxifen depletions of the GFPhi cells and MG in Rpe65-/- mice from day 13 to day 41, and from day 390 to day 420 promoted a small increase in cone survival. We found no evidence that the GFPhi cells were recruited from the circulation; all data pointed to a MG origin. MG and GFPhi cells were well segregated in the dystrophic retina; GFPhi cells were foremost in the photoreceptor cell layer, while MG were concentrated in the inner retina. CONCLUSIONS The expression of GFP on a subset of retinal mononuclear cells in CD11cGFP mice identified a distinct population of cells performing functions previously attributed to MG. Although GFPhi cells dominated the macrophage response to cone death in the photoreceptor cell layer, their ablation led to only an incremental increase in cone survival. The ability to identify, ablate, and isolate these cells will facilitate analysis of this activated, antigen-presenting subset of MG.
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Affiliation(s)
- Peter H Tang
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States
| | - Mark J Pierson
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States
| | - Neal D Heuss
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States
| | - Dale S Gregerson
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States.
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miR-183/96 plays a pivotal regulatory role in mouse photoreceptor maturation and maintenance. Proc Natl Acad Sci U S A 2017; 114:6376-6381. [PMID: 28559309 DOI: 10.1073/pnas.1618757114] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
MicroRNAs (miRNAs) are known to be essential for retinal maturation and functionality; however, the role of the most abundant miRNAs, the miR-183/96/182 cluster (miR-183 cluster), in photoreceptor cells remains unclear. Here we demonstrate that ablation of two components of the miR-183 cluster, miR-183 and miR-96, significantly affects photoreceptor maturation and maintenance in mice. Morphologically, early-onset dislocated cone nuclei, shortened outer segments and thinned outer nuclear layers are observed in the miR-183/96 double-knockout (DKO) mice. Abnormal photoreceptor responses, including abolished photopic electroretinography (ERG) responses and compromised scotopic ERG responses, reflect the functional changes in the degenerated retina. We further identify Slc6a6 as the cotarget of miR-183 and miR-96. The expression level of Slc6a6 is significantly higher in the DKO mice than in the wild-type mice. In contrast, Slc6a6 is down-regulated by adeno-associated virus-mediated overexpression of either miR-183 or miR-96 in wild-type mice. Remarkably, both silencing and overexpression of Slc6a6 in the retina are detrimental to the electrophysiological activity of the photoreceptors in response to dim light stimuli. We demonstrate that miR-183/96-mediated fine-tuning of Slc6a6 expression is indispensable for photoreceptor maturation and maintenance, thereby providing insight into the epigenetic regulation of photoreceptors in mice.
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