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Rapp J, Hospach A, Liang P, Schwämmle M, Renz L, Agostini H, Schlunck G, Bucher F. Oncostatin M Reduces Pathological Neovascularization in the Retina Through Müller Cell Activation. Invest Ophthalmol Vis Sci 2024; 65:22. [PMID: 38190125 PMCID: PMC10777876 DOI: 10.1167/iovs.65.1.22] [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: 03/19/2023] [Accepted: 12/01/2023] [Indexed: 01/09/2024] Open
Abstract
Purpose Continuous vision loss due to vasoproliferative eye disease still represents an unsolved issue despite anti-vascular endothelial growth factor (VEGF) therapy. The impact of signal transducer and activator of transcription 3 (STAT3) signaling on retinal angiogenesis and its potential use as a therapeutic target remain controversial. In vitro, oncostatin M (OSM), as a strong STAT3 activator, possesses robust proangiogenic activity. This study investigated to what extent the proangiogenic effects of OSM translate to the in vivo setting of vasoproliferative eye disease. Methods The in vitro effect of OSM on endothelial cells was investigated in the spheroid sprouting assay and through RNA sequencing. The mouse model for oxygen-induced retinopathy (OIR) was used to evaluate the impact of OSM in vivo. Signaling patterns were measured by western blot and retinal cryosections. Primary Müller cell cultures were used to evaluate the effect of OSM on the Müller cell secretome. Murine retinal vascular endothelial cells were isolated from OIR retinas using fluorescence-activated cell sorting (FACS) and were used for RNA sequencing. Results Although OSM induced pro-angiogenic responses in vitro, in the OIR model intravitreal injection of OSM reduced retinal neovascularization by 65.2% and vaso-obliteration by 45.5% in Müller cells. Injecting OSM into the vitreous activated the STAT3 signaling pathway in multiple retinal cell types, including Müller cells. In vitro, OSM treatment increased CXCL10 secretion. RNA sequencing of sorted vascular endothelial cells at OIR P17 following OSM treatment indicated downregulation of angiogenesis- and mitosis-associated genes. Conclusions In vivo, OSM reveals a beneficial angiomodulatory effect by activating Müller cells and changing their secretome. The data highlight contradictions between cytokine-induced effects in vitro and in vivo depending on the cell types mediating the effect.
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Affiliation(s)
- Julian Rapp
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Alban Hospach
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Paula Liang
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Melanie Schwämmle
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Lisa Renz
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Hansjürgen Agostini
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Günther Schlunck
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Felicitas Bucher
- Eye Center, Medical Center – University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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2
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Ferreira PA. Nucleocytoplasmic transport at the crossroads of proteostasis, neurodegeneration and neuroprotection. FEBS Lett 2023; 597:2567-2589. [PMID: 37597509 DOI: 10.1002/1873-3468.14722] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/21/2023]
Abstract
Nucleocytoplasmic transport comprises the multistep assembly, transport, and disassembly of protein and RNA cargoes entering and exiting nuclear pores. Accruing evidence supports that impairments to nucleocytoplasmic transport are a hallmark of neurodegenerative diseases. These impairments cause dysregulations in nucleocytoplasmic partitioning and proteostasis of nuclear transport receptors and client substrates that promote intracellular deposits - another hallmark of neurodegeneration. Disturbances in liquid-liquid phase separation (LLPS) between dense and dilute phases of biomolecules implicated in nucleocytoplasmic transport promote micrometer-scale coacervates, leading to proteinaceous aggregates. This Review provides historical and emerging principles of LLPS at the interface of nucleocytoplasmic transport, proteostasis, aging and noxious insults, whose dysregulations promote intracellular aggregates. E3 SUMO-protein ligase Ranbp2 constitutes the cytoplasmic filaments of nuclear pores, where it acts as a molecular hub for rate-limiting steps of nucleocytoplasmic transport. A vignette is provided on the roles of Ranbp2 in nucleocytoplasmic transport and at the intersection of proteostasis in the survival of photoreceptor and motor neurons under homeostatic and pathophysiological environments. Current unmet clinical needs are highlighted, including therapeutics aiming to manipulate aggregation-dissolution models of purported neurotoxicity in neurodegeneration.
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Affiliation(s)
- Paulo A Ferreira
- Department of Ophthalmology, Department of Pathology, Duke University Medical Center, NC, Durham, USA
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3
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Völkner M, Wagner F, Kurth T, Sykes AM, Del Toro Runzer C, Ebner LJA, Kavak C, Alexaki VI, Cimalla P, Mehner M, Koch E, Karl MO. Modeling inducible neuropathologies of the retina with differential phenotypes in organoids. Front Cell Neurosci 2023; 17:1106287. [PMID: 37213216 PMCID: PMC10196395 DOI: 10.3389/fncel.2023.1106287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 04/06/2023] [Indexed: 05/23/2023] Open
Abstract
Neurodegenerative diseases remain incompletely understood and therapies are needed. Stem cell-derived organoid models facilitate fundamental and translational medicine research. However, to which extent differential neuronal and glial pathologic processes can be reproduced in current systems is still unclear. Here, we tested 16 different chemical, physical, and cell functional manipulations in mouse retina organoids to further explore this. Some of the treatments induce differential phenotypes, indicating that organoids are competent to reproduce distinct pathologic processes. Notably, mouse retina organoids even reproduce a complex pathology phenotype with combined photoreceptor neurodegeneration and glial pathologies upon combined (not single) application of HBEGF and TNF, two factors previously associated with neurodegenerative diseases. Pharmacological inhibitors for MAPK signaling completely prevent photoreceptor and glial pathologies, while inhibitors for Rho/ROCK, NFkB, and CDK4 differentially affect them. In conclusion, mouse retina organoids facilitate reproduction of distinct and complex pathologies, mechanistic access, insights for further organoid optimization, and modeling of differential phenotypes for future applications in fundamental and translational medicine research.
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Affiliation(s)
- Manuela Völkner
- Technische Universität Dresden, Center for Regenerative Therapies Dresden (CRTD), Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Felix Wagner
- Technische Universität Dresden, Center for Regenerative Therapies Dresden (CRTD), Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Thomas Kurth
- Technische Universität Dresden, Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform Core Facility Electron Microscopy and Histology, Dresden, Germany
| | - Alex M. Sykes
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | | | - Lynn J. A. Ebner
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Cagri Kavak
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
| | - Vasileia Ismini Alexaki
- Technische Universität Dresden, Institute of Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, Dresden, Germany
| | - Peter Cimalla
- Technische Universität Dresden, Carl Gustav Carus Faculty of Medicine, Department of Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, Dresden, Germany
| | - Mirko Mehner
- Technische Universität Dresden, Carl Gustav Carus Faculty of Medicine, Department of Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, Dresden, Germany
| | - Edmund Koch
- Technische Universität Dresden, Carl Gustav Carus Faculty of Medicine, Department of Anesthesiology and Intensive Care Medicine, Clinical Sensoring and Monitoring, Dresden, Germany
| | - Mike O. Karl
- Technische Universität Dresden, Center for Regenerative Therapies Dresden (CRTD), Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
- *Correspondence: Mike O. Karl, ,
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4
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Rankouhi TR, Keulen DV, Tempel D, Venhorst J. Oncostatin M: Risks and Benefits of a Novel Therapeutic Target for Atherosclerosis. Curr Drug Targets 2022; 23:1345-1369. [PMID: 35959619 DOI: 10.2174/1389450123666220811101032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/30/2022] [Accepted: 06/03/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND Cardiovascular disease (CVD) is a leading cause of death worldwide. It is predicted that approximately 23.6 million people will die from CVDs annually by 2030. Therefore, there is a great need for an effective therapeutic approach to combat this disease. The European Cardiovascular Target Discovery (CarTarDis) consortium identified Oncostatin M (OSM) as a potential therapeutic target for atherosclerosis. The benefits of modulating OSM - an interleukin (IL)-6 family cytokine - have since been studied for multiple indications. However, as decades of high attrition rates have stressed, the success of a drug target is determined by the fine balance between benefits and the risk of adverse events. Safety issues should therefore not be overlooked. OBJECTIVE In this review, a risk/benefit analysis is performed on OSM inhibition in the context of atherosclerosis treatment. First, OSM signaling characteristics and its role in atherosclerosis are described. Next, an overview of in vitro, in vivo, and clinical findings relating to both the benefits and risks of modulating OSM in major organ systems is provided. Based on OSM's biological function and expression profile as well as drug intervention studies, safety concerns of inhibiting this target have been identified, assessed, and ranked for the target population. CONCLUSION While OSM may be of therapeutic value in atherosclerosis, drug development should also focus on de-risking the herein identified major safety concerns: tissue remodeling, angiogenesis, bleeding, anemia, and NMDA- and glutamate-induced neurotoxicity. Close monitoring and/or exclusion of patients with various comorbidities may be required for optimal therapeutic benefit.
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Affiliation(s)
- Tanja Rouhani Rankouhi
- Department of Risk Analysis for Products in Development, TNO, Utrechtseweg 48, 3704 HE, Zeist, The Netherlands
| | - Daniëlle van Keulen
- SkylineDx BV, Science and Clinical Development, 3062 ME Rotterdam, The Netherlands
| | - Dennie Tempel
- SkylineDx BV, Science and Clinical Development, 3062 ME Rotterdam, The Netherlands
| | - Jennifer Venhorst
- Department of Risk Analysis for Products in Development, TNO, Utrechtseweg 48, 3704 HE, Zeist, The Netherlands
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Chen Y, Xia Q, Zeng Y, Zhang Y, Zhang M. Regulations of Retinal Inflammation: Focusing on Müller Glia. Front Cell Dev Biol 2022; 10:898652. [PMID: 35573676 PMCID: PMC9091449 DOI: 10.3389/fcell.2022.898652] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/11/2022] [Indexed: 12/12/2022] Open
Abstract
Retinal inflammation underlies multiple prevalent retinal diseases. While microglia are one of the most studied cell types regarding retinal inflammation, growing evidence shows that Müller glia play critical roles in the regulation of retinal inflammation. Müller glia express various receptors for cytokines and release cytokines to regulate inflammation. Müller glia are part of the blood-retinal barrier and interact with microglia in the inflammatory responses. The unique metabolic features of Müller glia in the retina makes them vital for retinal homeostasis maintenance, regulating retinal inflammation by lipid metabolism, purine metabolism, iron metabolism, trophic factors, and antioxidants. miRNAs in Müller glia regulate inflammatory responses via different mechanisms and potentially regulate retinal regeneration. Novel therapies are explored targeting Müller glia for inflammatory retinal diseases treatment. Here we review new findings regarding the roles of Müller glia in retinal inflammation and discuss the related novel therapies for retinal diseases.
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Affiliation(s)
- Yingying Chen
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Qinghong Xia
- Operating Room of Anesthesia Surgery Center, West China Hospital, Sichuan University, Chengdu, China
- West China School of Nursing, Sichuan University, Chengdu, China
| | - Yue Zeng
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Yun Zhang
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Meixia Zhang
- Department of Ophthalmology, Sichuan University West China Hospital, Sichuan University, Chengdu, China
- Research Laboratory of Macular Disease, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Meixia Zhang,
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6
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Yang JY, Lu B, Feng Q, Alfaro JS, Chen PH, Loscalzo J, Wei WB, Zhang YY, Lu SJ, Wang S. Retinal Protection by Sustained Nanoparticle Delivery of Oncostatin M and Ciliary Neurotrophic Factor Into Rodent Models of Retinal Degeneration. Transl Vis Sci Technol 2021; 10:6. [PMID: 34347033 PMCID: PMC8340648 DOI: 10.1167/tvst.10.9.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Retinitis pigmentosa (RP) is caused by mutations in more than 60 genes. Mutation-independent approaches to its treatment by exogeneous administration of neurotrophic factors that will preserve existing retinal anatomy and visual function are a rational strategy. Ciliary neurotrophic factor (CNTF) and oncostatin M (OSM) are two potent survival factors for neurons. However, growth factors degrade rapidly if administered directly. A sustained delivery of growth factors is required for translating their potential therapeutic benefit into patients. Methods Stable and biocompatible nanoparticles (NP) that incorporated with CNTF and OSM (CNTF- and OSM-NP) were formulated. Both NP-trophic factors were tested in vitro using photoreceptor progenitor cells (PPC) and retinal ganglion progenitor cells (RGPC) derived from induced pluripotent stem cells and in vivo using an optic nerve crush model for glaucoma and the Royal College of Surgeons rat, model of RP (n = 8/treatment) by intravitreal delivery. Efficacy was evaluated by electroretinography and optokinetic response. Retinal histology and a whole mount analysis were performed at the end of experiments. Results Significant prosurvival and pro-proliferation effects of both complexes were observed in both photoreceptor progenitor cells and RGPC in vitro. Importantly, significant RGC survival and preservation of vision and photoreceptors in both complex-treated animals were observed compared with control groups. Conclusions These results demonstrate that NP-trophic factors are neuroprotective both in vitro and in vivo. A single intravitreal delivery of both NP-trophic factors offered neuroprotection in animal models of retinal degeneration. Translational Relevance Sustained nanoparticle delivery of neurotrophic factors may offer beneficial effects in slowing down progressive retinal degenerative conditions, including retinitis pigmentosa, age-related macular degeneration, and glaucoma.
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Affiliation(s)
- Jing-Yan Yang
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.,Beijing Tongren Hospital, Capital Medical University, Beijing, P.R. China
| | - Bin Lu
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Qiang Feng
- NanoNeuron Therapeutics and HebeCell Corp., Natick, MA, USA
| | - Jorge S Alfaro
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Po-Hsuen Chen
- NanoNeuron Therapeutics and HebeCell Corp., Natick, MA, USA
| | - Joseph Loscalzo
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Wen-Bin Wei
- Beijing Tongren Hospital, Capital Medical University, Beijing, P.R. China
| | - Ying-Yi Zhang
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shi-Jiang Lu
- NanoNeuron Therapeutics and HebeCell Corp., Natick, MA, USA
| | - Shaomei Wang
- Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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7
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Pathogenic mechanisms contributing to the vulnerability of aging human photoreceptor cells. Eye (Lond) 2021; 35:2917-2929. [PMID: 34079093 DOI: 10.1038/s41433-021-01602-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 04/29/2021] [Accepted: 05/10/2021] [Indexed: 01/04/2023] Open
Abstract
In human retina, photoreceptor cell death (PCD) is a slow but conspicuous event, which continues with aging. Rods die earlier than cones, the latter continue to alter in a subtle manner until advanced aging. This review summarizes the existing information on age-related changes in photoreceptor cells, especially cones and analyses the possible associated factors. Oxidative and nitrosative stress are involved in photoreceptor alterations, which may stem from light and iron toxicity and other sources. Lipid peroxidation in macular photoreceptor outer segments and mitochondrial aberrations are prominent in aging. It is important to understand how those changes ultimately trigger PCD. The redistribution of calbindin D-28K and long/middle-wavelength-sensitive opsin in the parafoveal and perifoveal cones, anomalies in their somata and axons are strong predictors of their increasing vulnerability with aging. Signs of reduced autophagy, with autophagosomes containing organelle remnants are seen in aging photoreceptor cells. Currently, mechanisms that lead to human PCD are unknown; some observations favour apoptosis as a pathway. Since cones appear to change slowly, there is an opportunity to reverse those changes before they die. Therefore, a full understanding of how cones alter and the molecular pathways they utilize for survival must be the future research goal. Recent approaches to prevent PCD in aging and diseases are highlighted.
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8
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Rps27a might act as a controller of microglia activation in triggering neurodegenerative diseases. PLoS One 2020; 15:e0239219. [PMID: 32941527 PMCID: PMC7498011 DOI: 10.1371/journal.pone.0239219] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 09/01/2020] [Indexed: 01/10/2023] Open
Abstract
Neurodegenerative diseases (NDDs) are increasing serious menaces to human health in the recent years. Despite exhibiting different clinical phenotypes and selective neuronal loss, there are certain common features in these disorders, suggesting the presence of commonly dysregulated pathways. Identifying causal genes and dysregulated pathways can be helpful in providing effective treatment in these diseases. Interestingly, in spite of the considerable researches on NDDs, to the best of our knowledge, no dysregulated genes and/or pathways were reported in common across all the major NDDs so far. In this study, for the first time, we have applied the three-way interaction model, as an approach to unravel sophisticated gene interactions, to trace switch genes and significant pathways that are involved in six major NDDs. Subsequently, a gene regulatory network was constructed to investigate the regulatory communication of statistically significant triplets. Finally, KEGG pathway enrichment analysis was applied to find possible common pathways. Because of the central role of neuroinflammation and immune system responses in both pathogenic and protective mechanisms in the NDDs, we focused on immune genes in this study. Our results suggest that "cytokine-cytokine receptor interaction" pathway is enriched in all of the studied NDDs, while "osteoclast differentiation" and "natural killer cell mediated cytotoxicity" pathways are enriched in five of the NDDs each. The results of this study indicate that three pathways that include "osteoclast differentiation", "natural killer cell mediated cytotoxicity" and "cytokine-cytokine receptor interaction" are common in five, five and six NDDs, respectively. Additionally, our analysis showed that Rps27a as a switch gene, together with the gene pair {Il-18, Cx3cl1} form a statistically significant and biologically relevant triplet in the major NDDs. More specifically, we suggested that Cx3cl1 might act as a potential upstream regulator of Il-18 in microglia activation, and in turn, might be controlled with Rps27a in triggering NDDs.
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9
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Di Pierdomenico J, Martínez-Vacas A, Hernández-Muñoz D, Gómez-Ramírez AM, Valiente-Soriano FJ, Agudo-Barriuso M, Vidal-Sanz M, Villegas-Pérez MP, García-Ayuso D. Coordinated Intervention of Microglial and Müller Cells in Light-Induced Retinal Degeneration. Invest Ophthalmol Vis Sci 2020; 61:47. [PMID: 32232352 PMCID: PMC7401701 DOI: 10.1167/iovs.61.3.47] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Purpose To analyze the role of microglial and Müller cells in the formation of rings of photoreceptor degeneration caused by phototoxicity. Methods Two-month-old Sprague-Dawley rats were exposed to light and processed 1, 2, or 3 months later. Retinas were dissected as whole-mounts, immunodetected for microglial cells, Müller cells, and S- and L/M-cones and analyzed using fluorescence, thunder imaging, and confocal microscopy. Cone populations were automatically counted and isodensity maps constructed to document cone topography. Results Phototoxicity causes a significant progressive loss of S- and L/M-cones of up to 68% and 44%, respectively, at 3 months after light exposure (ALE). One month ALE, we observed rings of cone degeneration in the photosensitive area of the superior retina. Two and 3 months ALE, these rings had extended to the central and inferior retina. Within the rings of cone degeneration, there were degenerating cones, often activated microglial cells, and numerous radially oriented processes of Müller cells that showed increased expression of intermediate filaments. Between 1 and 3 months ALE, the rings coalesced, and at the same time the microglial cells resumed a mosaic-like distribution, and there was a decrease of Müller cell gliosis at the areas devoid of cones. Conclusions Light-induced photoreceptor degeneration proceeds with rings of cone degeneration, as observed in inherited retinal degenerations in which cone death is secondary to rod degeneration. The spatiotemporal relationship of cone death microglial cell activation and Müller cell gliosis within the rings of cone degeneration suggests that, although both glial cells are involved in the formation of the rings, they may have coordinated actions and, while microglial cells may be more involved in photoreceptor phagocytosis, Müller cells may be more involved in cone and microglial cell migration, retinal remodeling and glial seal formation.
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10
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Photoreceptor Protection by Mesencephalic Astrocyte-Derived Neurotrophic Factor (MANF). eNeuro 2018; 5:eN-CFN-0109-18. [PMID: 29687079 PMCID: PMC5909182 DOI: 10.1523/eneuro.0109-18.2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 04/09/2018] [Indexed: 12/21/2022] Open
Abstract
Retinal degenerations are a major cause of vision impairment and blindness. Neuroprotective therapy is a promising therapeutic strategy for retinal degenerative diseases. We investigated a novel neurotrophic factor mesencephalic astrocyte-derived neurotrophic factor (MANF) in the retina. MANF is expressed at a high level during postnatal development and the expression declines to a lower level as the retina matures. Müller cells are the major cells expressing MANF. It is also found in the retinal ganglion cells, in the inner nuclear layer (INL) neurons, and in retinal pigment epithelial (RPE) cells. Intravitreal injection of recombinant human (rh)MANF significantly protected rod and cone photoreceptors in rats carrying the rhodopsin S334ter mutation, and preserved electroretinograms (ERGs) in the rd10 (Pde6brd10/rd10 ) mice. These results indicate that MANF is a native protein in the retina and is a potent neurotrophic factor for photoreceptor protection.
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11
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LaVail MM, Nishikawa S, Steinberg RH, Naash MI, Duncan JL, Trautmann N, Matthes MT, Yasumura D, Lau-Villacorta C, Chen J, Peterson WM, Yang H, Flannery JG. Phenotypic characterization of P23H and S334ter rhodopsin transgenic rat models of inherited retinal degeneration. Exp Eye Res 2018; 167:56-90. [PMID: 29122605 PMCID: PMC5811379 DOI: 10.1016/j.exer.2017.10.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 10/25/2017] [Accepted: 10/31/2017] [Indexed: 02/07/2023]
Abstract
We produced 8 lines of transgenic (Tg) rats expressing one of two different rhodopsin mutations in albino Sprague-Dawley (SD) rats. Three lines were generated with a proline to histidine substitution at codon 23 (P23H), the most common autosomal dominant form of retinitis pigmentosa in the United States. Five lines were generated with a termination codon at position 334 (S334ter), resulting in a C-terminal truncated opsin protein lacking the last 15 amino acid residues and containing all of the phosphorylation sites involved in rhodopsin deactivation, as well as the terminal QVAPA residues important for rhodopsin deactivation and trafficking. The rates of photoreceptor (PR) degeneration in these models vary in proportion to the ratio of mutant to wild-type rhodopsin. The models have been widely studied, but many aspects of their phenotypes have not been described. Here we present a comprehensive study of the 8 Tg lines, including the time course of PR degeneration from the onset to one year of age, retinal structure by light and electron microscopy (EM), hemispheric asymmetry and gradients of rod and cone degeneration, rhodopsin content, gene dosage effect, rapid activation and invasion of the outer retina by presumptive microglia, rod outer segment disc shedding and phagocytosis by the retinal pigmented epithelium (RPE), and retinal function by the electroretinogram (ERG). The biphasic nature of PR cell death was noted, as was the lack of an injury-induced protective response in the rat models. EM analysis revealed the accumulation of submicron vesicular structures in the interphotoreceptor space during the peak period of PR outer segment degeneration in the S334ter lines. This is likely due to the elimination of the trafficking consensus domain as seen before as with other rhodopsin mutants lacking the C-terminal QVAPA. The 8 rhodopsin Tg lines have been, and will continue to be, extremely useful models for the experimental study of inherited retinal degenerations.
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Affiliation(s)
- Matthew M LaVail
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Shimpei Nishikawa
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Roy H Steinberg
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Room 2011, Houston, TX 77204-5060, USA.
| | - Jacque L Duncan
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Nikolaus Trautmann
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Michael T Matthes
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Douglas Yasumura
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA
| | - Cathy Lau-Villacorta
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Jeannie Chen
- Zilka Neurogenetic Institute, USC Keck School of Medicine, Los Angeles, CA 90089-2821, USA.
| | - Ward M Peterson
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - Haidong Yang
- Beckman Vision Center, University of California, San Francisco, San Francisco, CA 94143-0730, USA.
| | - John G Flannery
- School of Optometry, UC Berkeley, Berkeley, CA 94720-2020, USA.
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12
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Protective effect of clusterin on rod photoreceptor in rat model of retinitis pigmentosa. PLoS One 2017; 12:e0182389. [PMID: 28767729 PMCID: PMC5540409 DOI: 10.1371/journal.pone.0182389] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/17/2017] [Indexed: 01/09/2023] Open
Abstract
Retinitis Pigmentosa (RP) begins with the death of rod photoreceptors and is slowly followed by a gradual loss of cones and a rearrangement of the remaining retinal neurons. Clusterin is a chaperone protein that protects cells and is involved in various pathophysiological stresses, including retinal degeneration. Using a well-established transgenic rat model of RP (rhodopsin S334ter), we investigated the effects of clusterin on rod photoreceptor survival. To investigate the role of clusterin in S334ter-line3 retinas, Voronoi analysis and immunohistochemistry were used to evaluate the geometry of rod distribution. Additionally, immunoblot analysis, Bax activation, STAT3 and Akt phosphorylation were used to evaluate the pathway involved in rod cell protection. In this study, clusterin (10μg/ml) intravitreal treatment produced robust preservation of rod photoreceptors in S334ter-line3 retina. The mean number of rods in 1mm2 was significantly greater in clusterin injected RP retinas (postnatal (P) 30, P45, P60, & P75) than in age-matched saline injected RP retinas (P<0.01). Clusterin activated Akt, STAT3 and significantly reduced Bax activity; in addition to inducing phosphorylated STAT3 in Müller cells, which suggests it may indirectly acts on photoreceptors. Thus, clusterin treatment may interferes with mechanisms leading to rod death by suppressing cell death through activation of Akt and STAT3, followed by Bax suppression. Novel insights into the pathway of how clusterin promotes the rod cell survival suggest this treatment may be a potential therapeutic strategy to slow progression of vision loss in human RP.
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Protective effect of resveratrol against light-induced retinal degeneration in aged SAMP8 mice. Oncotarget 2017; 8:65778-65788. [PMID: 29029471 PMCID: PMC5630371 DOI: 10.18632/oncotarget.19473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/24/2017] [Indexed: 12/17/2022] Open
Abstract
Purpose The purpose of this study was to determine the protective effects of Resveratrol (RESV) on acute bright light-induced retinal degeneration in aged senescence accelerated mouse strain. Methods Ten three-month-old male SAMP8 mice (prone to aging) were randomly assigned to two experimental dietary groups: one untreated group and one RESV treatment group (n=20 eyes for each group). After 30 days of treatment, mice were exposed to intense bright light. Ten male SAMR1 mice (resistant to aging) served as control (n=20 eyes). The protective effects of RESV administration on light-induced retinal degeneration in SAMP8 strain as well as the effect of bright light damage in the retinas of SAMP8 mice were analyzed by electroretinography (ERG), retinal histology, mRNA, protein and lipid profile. Results 68%-85% of a-wave amplitude and 72%-92% of b-wave amplitude were persevered by RESV in SAMP8 mice that were exposed to light damage. Also, RESV preserved their photoreceptor nuclei. mRNA expression of neuroprotective factors leukemia inhibitory factor (LIF), brain derived neurotrophic factor (BDNF), oncostatin M (OSM), cardiotrophin 1(CT-1) and cardiotrophin-like cytokine (CLC) were up-regulated 28, 8, 7, 5 and 9-fold in SAMP8 mice after RESV treatment. In addition, RESV could suppress the NF-κB pathway by down-regulating the expression of pIκB. Light damage led to increase of saturated FA, monoenoic FA, n6 PUFA and n6/n3 ratio and decrease of Docosahexaenoic acid (DHA). There was no significant difference on DHA and the ratio of n6/n3-FA between the untreated and RESV treated SAMP8 mice. Conclusions Collectively, our study provides evidence that RESV prevents light-induced retinal damage associated with aging.
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Järgen P, Dietrich A, Herling AW, Hammes HP, Wohlfart P. The role of insulin resistance in experimental diabetic retinopathy-Genetic and molecular aspects. PLoS One 2017; 12:e0178658. [PMID: 28575111 PMCID: PMC5456117 DOI: 10.1371/journal.pone.0178658] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 05/16/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Diabetic retinopathy is characterized by defects in the retinal neurovascular unit. The underlying mechanisms of impairment-including reactive intermediates and growth-factor dependent signalling pathways and their possible interplay are incompletely understood. This study aims to assess the relative role of hyperglycemia and hyperinsulinemia alone or in combination on the gene expression patterning in the retina of animal models of diabetes. MATERIAL AND METHODS As insulinopenic, hyperglycemic model reflecting type 1 diabetes, male STZ-Wistar rats (60mg/kg BW; i.p. injection at life age week 7) were used. Male obese ZDF rats (fa/fa) were used as type-2 diabetes model characterized by persisting hyperglycemia and transient hyperinsulinemia. Male obese ZF rats (fa/fa) were used reflecting euglycemia and severe insulin resistance. All groups were kept till an age of 20 weeks on respective conditions together with appropriate age-matched controls. Unbiased gene expression analysis was performed per group using Affymetrix gene arrays. Bioinformatics analysis included analysis for clustering and differential gene expression, and pathway and upstream activator analysis. Gene expression differences were confirmed by microfluidic card PCR technology. RESULTS The most complex genetic regulation in the retina was observed in ZDF rats with a strong overlap to STZ-Wistar rats. Surprisingly, systemic insulin resistance alone in ZF rats without concomitant hyperglycemia did not induce any significant change in retinal gene expression pattern. Pathway analysis indicate an overlap between ZDF rats and STZ-treated rats in pathways like complement system activation, acute phase response signalling, and oncostatin-M signalling. Major array gene expression changes could be confirmed by subsequent PCR. An analysis of upstream transcriptional regulators revealed interferon-γ, interleukin-6 and oncostatin-M in STZ and ZDF rats. CONCLUSIONS: Systemic hyperinsulinaemia without hyperglycemia does not result in significant gene expression changes in retina. In contrast, persistent systemic hyperglycemia boosts much stronger expression changes with a limited number of known and new key regulators.
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Affiliation(s)
- Patrick Järgen
- 5 Medical Department, Universitätsmedizin Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Axel Dietrich
- Sanofi Aventis Deutschland GmbH, R&D Lead Generation Candidate Realization, Structure, Design and Informatics, Industriepark Höchst, Frankfurt, Germany
| | - Andreas W. Herling
- Sanofi Aventis Deutschland GmbH, TA Diabetes R&D, Industriepark Höchst, Frankfurt, Germany
| | - Hans-Peter Hammes
- 5 Medical Department, Universitätsmedizin Mannheim (UMM), University of Heidelberg, Mannheim, Germany
| | - Paulus Wohlfart
- Sanofi Aventis Deutschland GmbH, TA Diabetes R&D, Industriepark Höchst, Frankfurt, Germany
- * E-mail:
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Affiliation(s)
- Hassan Ghasemi
- Department of Ophthalmology, Shahed University, Tehran, Iran
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Novikova YP, Gancharova OS, Eichler OV, Philippov PP, Grigoryan EN. Preventive and therapeutic effects of SkQ1-containing Visomitin eye drops against light-induced retinal degeneration. BIOCHEMISTRY (MOSCOW) 2015; 79:1101-10. [PMID: 25519068 DOI: 10.1134/s0006297914100113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The human retina is constantly affected by light of varying intensity, this being especially true for photoreceptor cells and retinal pigment epithelium. Traditionally, photoinduced damages of the retina are induced by visible light of high intensity in albino rats using the LIRD (light-induced retinal degeneration) model. This model allows study of pathological processes in the retina and the search for retinoprotectors preventing retinal photodamage. In addition, the etiology and mechanisms of retina damage in the LIRD model have much in common with the mechanisms of the development of age-related retinal disorders, in particular, with age-related macular degeneration (AMD). We have studied preventive and therapeutic effects of Visomitin eye drops (based on the mitochondria-targeted antioxidant SkQ1) on albino rat retinas damaged by bright light. In the first series of experiments, rats receiving Visomitin for two weeks prior to illumination demonstrated significantly less expressed atrophic and degenerative changes in the retina compared to animals receiving similar drops with no SkQ1. In the second series, the illuminated rats were treated for two weeks with Visomitin or similar drops without SkQ1. The damaged retinas of the experimental animals were repaired much more effectively than those of the control animals. Therefore, we conclude that Visomitin SkQ1-containing eye drops have pronounced preventive and therapeutic effects on the photodamaged retina and might be recommended as a photoprotector and a pharmaceutical preparation for the treatment of AMD in combination with conventional medicines.
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Affiliation(s)
- Yu P Novikova
- Koltzov Institute of Developmental Biology, Moscow, 119334, Russia.
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Cho KI, Orry A, Park SE, Ferreira PA. Targeting the cyclophilin domain of Ran-binding protein 2 (Ranbp2) with novel small molecules to control the proteostasis of STAT3, hnRNPA2B1 and M-opsin. ACS Chem Neurosci 2015; 6:1476-85. [PMID: 26030368 DOI: 10.1021/acschemneuro.5b00134] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cyclophilins are peptidyl cis-trans prolyl isomerases (PPIases), whose activity is typically inhibited by cyclosporine A (CsA), a potent immunosuppressor. Cyclophilins are also chaperones. Emerging evidence supports that cyclophilins present nonoverlapping PPIase and chaperone activities. The proteostasis of the disease-relevant substrates, signal transducer and activator of transcription 3 and 5 (STAT3/STAT5), heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1), and M-opsin, is regulated by nonoverlapping chaperone and PPIase activities of the cyclophilin domain (CY) of Ranbp2, a multifunctional and modular scaffold that controls nucleocytoplasmic shuttling and proteostasis of selective substrates. Although highly homologous, CY and the archetypal cyclophilin A (CyPA) present distinct catalytic and CsA-binding activities owing to unique structural features between these cylophilins. We explored structural idiosyncrasies between CY and CyPA to screen in silico nearly 9 million small molecules (SM) against the CY PPIase pocket and identify SMs with selective bioactivity toward STAT3, hnRNPA2B1, or M-opsin proteostasis. We found three classes of SMs that enhance the cytokine-stimulated transcriptional activity of STAT3 without changing latent and activated STAT3 levels, down-regulate hnRNPA2B1 or M-opsin proteostasis, or a combination of these. Further, a SM that suppresses hnRNPA2B1 proteostasis also inhibits strongly and selectively the PPIase activity of CY. This study unravels chemical probes for multimodal regulation of CY of Ranbp2 and its substrates, and this regulation likely results in the allosterism stemming from the interconversion of conformational substates of cyclophilins. The results also demonstrate the feasibility of CY in drug discovery against disease-relevant substrates controlled by Ranbp2, and they open new opportunities for therapeutic interventions.
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Affiliation(s)
- Kyoung-in Cho
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Andrew Orry
- MolSoft LLC, San Diego, California 92121, United States
| | - Se Eun Park
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Paulo A. Ferreira
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina 27710, United States
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, United States
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Chang SH, Hwang CS, Yin JH, Chen SD, Yang DI. Oncostatin M-dependent Mcl-1 induction mediated by JAK1/2-STAT1/3 and CREB contributes to bioenergetic improvements and protective effects against mitochondrial dysfunction in cortical neurons. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2306-25. [PMID: 25986861 DOI: 10.1016/j.bbamcr.2015.05.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 04/24/2015] [Accepted: 05/08/2015] [Indexed: 11/27/2022]
Abstract
Oncostatin M (OSM), a cytokine in the interleukin-6 (IL-6) family, has been proposed to play a protective role in the central nervous system, such as attenuation of excitotoxicity induced by N-methyl-D-aspartate (NMDA) and glutamate. However, the potential neuroprotective effects of OSM against mitochondrial dysfunction have never been reported. In the present study, we tested the hypothesis that OSM may confer neuronal resistance against 3-nitropropionic acid (3-NP), a plant toxin that irreversibly inhibits the complex II of the mitochondrial electron transport chain, and characterized the underlying molecular mechanisms. We found that OSM preconditioning dose- and time-dependently protected cortical neurons against 3-NP toxicity. OSM stimulated expression of myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic Bcl-2 family member expressed in differentiating myeloid cells, that required prior phosphorylation of Janus kinase-1 (JAK1), JAK2, extracellular signal-regulated kinase-1/2 (ERK1/2), signal transducer and activator of transcription-3 (STAT3), STAT1, and cAMP-response element-binding protein (CREB). Pharmacological inhibitors of JAK1, JAK2, ERK1/2, STAT3, STAT1, and CREB as well as the siRNA targeting at STAT3 and Mcl-1 all abolished OSM-dependent 3-NP resistance. Finally, OSM-dependent Mcl-1 induction contributed to the enhancements of mitochondrial bioenergetics including increases in spare respiratory capacity and ATP production. In conclusion, our findings indicated that OSM induces Mcl-1 expression via activation of ERK1/2, JAK1/2, STAT1/3, and CREB; furthermore, OSM-mediated Mcl-1 induction contributes to bioenergetic improvements and neuroprotective effects against 3-NP toxicity in cortical neurons. OSM may thus serve as a novel neuroprotective agent against mitochondrial dysfunction commonly associated with pathogenic mechanisms underlying neurodegeneration.
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Affiliation(s)
- Shih-Hsin Chang
- Institute of Brain Science and Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Chi-Shin Hwang
- Department of Neurology, Taipei City Hospital, Taipei, Taiwan; Department of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jiu-Haw Yin
- Department of Neurology, Cheng Hsin General Hospital, Taipei, Taiwan; Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Shang-Der Chen
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan; Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Ding-I Yang
- Institute of Brain Science and Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
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STAT3 promotes survival of mutant photoreceptors in inherited photoreceptor degeneration models. Proc Natl Acad Sci U S A 2014; 111:E5716-23. [PMID: 25512545 DOI: 10.1073/pnas.1411248112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Inherited photoreceptor degenerations (IPDs), a group of incurable progressive blinding diseases, are caused by mutations in more than 200 genes, but little is known about the molecular pathogenesis of photoreceptor (PR) death. Increased retinal expression of STAT3 has been observed in response to many retinal insults, including IPDs, but the role of this increase in PR death is unknown. Here, we show that the expression of Stat3 is increased in PRs of the Tg(RHO P347S) and Prph2(rds) (/+) mouse models of IPD and is activated by tyrosine phosphorylation. PR-specific deletion of Stat3 substantially accelerated PR degeneration in both mutant strains. In contrast, increased PR-specific expression of ROSA26 (R26) alleles encoding either WT STAT3 (Stat3(wt)) or the gain-of-function variant STAT3(C) (Stat3(C)) improved PR survival in both models. Moreover, PR signaling in Tg(RHO P347S) mice carrying either a R26-Stat3(wt) or R26-Stat3(C) allele demonstrated increased a-wave amplitude of the scotopic electroretinogram. Phosphorylation of STAT3 at tyrosine 705 was required for the prosurvival effect because an R26-Stat3(Y705F) allele was not protective. The prosurvival role of enhanced Stat3 activity was validated using recombinant adenoassociated virus (rAAV) vector-mediated PR Stat3 expression in Tg(RHO P347S) mice. Our findings (i) establish that the increase in endogenous PR Stat3 expression is a protective response in IPDs, (ii) suggest that therapeutic augmentation of PR Stat3 expression has potential as a common neuroprotective therapy for these disorders, and (iii) indicate that prosurvival molecules whose expression is increased in mutant PRs may have promise as novel therapies for IPDs.
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Xia X, Wen R, Chou TH, Li Y, Wang Z, Porciatti V. Protection of pattern electroretinogram and retinal ganglion cells by oncostatin M after optic nerve injury. PLoS One 2014; 9:e108524. [PMID: 25243471 PMCID: PMC4171539 DOI: 10.1371/journal.pone.0108524] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 09/01/2014] [Indexed: 12/25/2022] Open
Abstract
Injury to retinal ganglion cell (RGC) axons leads to selective loss of RGCs and vision. Previous studies have shown that exogenous neurotrophic factors promote RGC survival. We investigated the neuroprotective effects of oncostatin M (OSM), a member of the IL-6 family of cytokines, on pattern electroretinogram (PERG) and RGC survival after optic nerve crush (ON-crush) in the mouse. BALB/C mice received ON-crush in the left eyes for either 4-second or 1-second duration (4-s or 1-s). Fluoro-gold retrograde labeling was used to identify RGCs. RGC function was assessed by PERG measurement. OSM or CNTF protein was injected intravitreally immediately after ON-crush. OSM responsive cells were identified by localization of increased STAT3 phosphorylation. Significant higher RGC survival (46% of untreated control) was seen in OSM-treated eyes when assessed 2 weeks after 4-s ON-crush as compared to that (14% of untreated control) of the PBS-treated eyes (P<0.001). In addition, PERG amplitude was significantly higher in eyes treated with OSM or CNTF 1 week after 1-s ON-crush (36% of baseline) as compared with the amplitude of PBS-treated eyes (19% of the baseline, P = 0.003). An increase in STAT3 phosphorylation was localized in Müller layer after OSM treatment, suggesting that Müller cells mediate the effect of OSM. Our results demonstrate that one single injection of either OSM or CNTF after ON-crush improves RGC survival together with their electrophysiological activity. These data provide proof-of-concept for using neurotrophic factors OSM and CNTF for RGC degenerative diseases, including glaucoma and acute optic nerve trauma.
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Affiliation(s)
- Xin Xia
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
- Department of Ophthalmology, Shanghai First People’s Hospital, Jiaotong University, Shanghai, China
- Shanghai Key Laboratory for Ocular Fundus Diseases, Shanghai, China
| | - Rong Wen
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Yiwen Li
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Zhengying Wang
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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Oncostatin M reduces lesion size and promotes functional recovery and neurite outgrowth after spinal cord injury. Mol Neurobiol 2014; 50:1142-51. [PMID: 24996996 DOI: 10.1007/s12035-014-8795-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 06/15/2014] [Indexed: 12/25/2022]
Abstract
The family of interleukin (IL)-6 like cytokines plays an important role in the neuroinflammatory response to injury by regulating both neural as well as immune responses. Here, we show that expression of the IL-6 family member oncostatin M (OSM) and its receptor is upregulated after spinal cord injury (SCI). To reveal the relevance of increased OSM signaling in the pathophysiology of SCI, OSM was applied locally after spinal cord hemisection in mice. OSM treatment significantly improved locomotor recovery after mild and severe SCI. Improved recovery in OSM-treated mice was associated with a reduced lesion size. OSM significantly diminished astrogliosis and immune cell infiltration. Thus, OSM limits secondary damage after CNS trauma. In vitro viability assays demonstrated that OSM protects primary neurons in culture from cell death, suggesting that the underlying mechanism involves direct neuroprotective effects of OSM. Furthermore, OSM dose-dependently promoted neurite outgrowth in cultured neurons, indicating that the cytokine plays an additional role in CNS repair. Indeed, our in vivo experiments demonstrate that OSM treatment increases plasticity of serotonergic fibers after SCI. Together, our data show that OSM is produced at the lesion site, where it protects the CNS from further damage and promotes recovery.
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Kucharska J, Del Río P, Arango-Gonzalez B, Gorza M, Feuchtinger A, Hauck SM, Ueffing M. Cyr61 activates retinal cells and prolongs photoreceptor survival in rd1 mouse model of retinitis pigmentosa. J Neurochem 2014; 130:227-40. [PMID: 24593181 DOI: 10.1111/jnc.12704] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 02/27/2014] [Accepted: 02/27/2014] [Indexed: 01/08/2023]
Abstract
Subretinal injections with glial cell line-derived neurotrophic factor (GDNF) rescue morphology as well as function of rod cells in mouse and rat animal models of retinitis pigmentosa. At the same time, it is postulated that this effect is indirect, mediated by activation of retinal Müller glial (RMG) cells. Here, we show that Cyr61/CCN1, one of the secreted proteins up-regulated in primary RMG after glial cell line-derived neurotrophic factor stimulation, provides neuroprotective and pro-survival capacities: Recombinant Cyr61 significantly reduced photoreceptor (PR) cells death in organotypic cultures of Pde6b(rd1) retinas. To identify stimulated pathways in the retina, we treated Pde6b(rd1) retinal explants with Cyr61 and observed an overall increase in activated Erk1/2 and Stat3 signalling molecules characterized by activation-site-specific phosphorylation. To identify Cyr61 retinal target cells, we isolated primary porcine PR, RMG and retinal pigment epithelium (RPE) cells and exposed them separately to Cyr61. Here, RMG as well as RPE cells responded with induced phosphorylation of Erk1/2, Stat3 and Akt. In PR, no increase in phosphorylation in any of the studied proteins was detected, suggesting an indirect neuroprotective effect of Cyr61. Cyr61 may thus act as an endogenous pro-survival factor for PR, contributing to the complex repertoire of neuroprotective activities generated by RMG and RPE cells. We propose the following model of Cyr61 neuroprotection within the retina: Cyr61 stimulates retinal Müller glial (RMG) and retinal pigment epithelium (RPE) cells and activates PI3K/Akt, mitogen-activated protein kinase(MAPK)/Erk and Janus kinase(JAK)/Stat-signalling pathways in these cells. Phosphorylated Stat3 and Erk1/2 presumably translocate to the nucleus, induce transcriptional changes, which increase secretion of neuroprotective agents that protect photoreceptors (PR) from mutation-induced death.
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Affiliation(s)
- Joanna Kucharska
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany; Research Unit Protein Science, Helmholtz Zentrum München, Neuherberg, Germany
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Five-year follow-up of macular morphologic changes after rhegmatogenous retinal detachment repair: Fourier domain OCT findings. Retina 2014; 33:2049-58. [PMID: 23591534 DOI: 10.1097/iae.0b013e3182891e81] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate serially long-term macular morphologic changes after successful macula-involving rhegmatogenous retinal detachment repair and correlate changes with macular function. METHODS Repeat Fourier domain optical coherence tomography (FD OCT) imaging and microperimetry (MP-1) testing of 8 of the initial cohort of 17 eyes studied 5 years earlier. RESULTS The mean follow-up after rhegmatogenous retinal detachment repair was 3.4 months (range, 1-8.5 months) for the first FD OCT and 5 years (range, 3.75-5.75 years) for the follow-up FD OCT. The final postoperative best-corrected visual acuity mean was 20/201 (range, 20/20 to counting fingers). Six eyes with final best-corrected visual acuity >20/40 had an intact external limiting membrane and progressive resolution of photoreceptor inner segment-outer segment junction disruption and/or subretinal fluid on serial FD OCT, which correlated with improvement in macular function on MP-1. Two eyes with poor or worsening best-corrected visual acuity on follow-up had persistent or worsening inner segment-outer segment disruption on serial FD OCT. External limiting membrane was intact in one eye and persistently disrupted in the other. CONCLUSION Macular function may progressively improve or worsen long-term after successful rhegmatogenous retinal detachment repair. Progressive resolution of subretinal fluid and/or inner segment-outer segment disruption on FD OCT correlated with improvement in macular function, whereas worsening or persistent inner segment-outer segment disruption correlates with worsening or persistently poor visual outcome.
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Métrailler S, Emery M, Schorderet DF, Cottet S, Roduit R. ERK1/2 pathway is activated in degenerated Rpe65-deficient mice. Exp Eye Res 2013; 116:86-95. [PMID: 24012986 DOI: 10.1016/j.exer.2013.08.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 08/10/2013] [Accepted: 08/22/2013] [Indexed: 12/30/2022]
Abstract
The MAPK family is composed of three majors kinases, JNK, p38 and ERK1/2, and is implicated in many degenerative processes, including retinal cell death. The purpose of our study was to evaluate the activation of ERK1/2 kinase, and its potential role in Müller cell gliosis, during photoreceptor cell death in Rpe65(-/-) mice. We assayed ERK1/2 mRNA and protein levels, and evaluated ERK1/2 phosphorylation involved in kinase activation, in 2, 4 and 6 month-old Rpe65(-/-) mice and in age-matched wild-type controls. No differences in ERK1/2 expression were detected between Rpe65(-/-) and wild-type mice, however, ERK1/2 phosphorylation was dramatically increased in the knock out mice at 4 and 6 months-of-age. Phosphorylated ERK1/2 co-localized with GFAP in the ganglion cell layer, and correlated with an increase in GFAP protein expression and retinal cell death. Accumulation of cFOS protein in the ganglion cell layer occurred concomitant with pERK1/2 activation. Müller cell proliferation was not observed. ERK1/2 activation did not occur in 2 month-old Rpe65(-/-) or in the Rpe65(-/-)/Gnat1(-/-) mice, in which no degeneration was evident. The observed activation ERK1/2 and GFAP, both markers of Müller cell gliosis, in the absence of Müller cell proliferation, is consistent with the activation of atypical gliosis occurring during the slow process of degeneration in Rpe65(-/-) mice. As Müller cell gliosis is activated in many neuronal and retinal degenerative diseases, further studies will be needed to determine whether atypical gliosis in Rpe65(-/-) mice contributes to, or protects against, the pathogenesis occurring in this model of Leber congenital amaurosis.
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Affiliation(s)
- S Métrailler
- IRO, Institute for Research in Ophthalmology, 1950 Sion, Switzerland
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Peng C, Yin X, Li M, He T, Li G. Construction of a eukaryotic expression plasmid for human retina-derived neurotrophin-3. Neural Regen Res 2013; 8:1031-40. [PMID: 25206397 PMCID: PMC4145883 DOI: 10.3969/j.issn.1673-5374.2013.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 03/26/2013] [Indexed: 11/18/2022] Open
Abstract
Neurotrophin-3 (NT-3) can promote the repair of central nervous system and retinal damage. In previous reports, NT-3 has been expressed by viral vectors. However, plasmid vectors have a safer profile compared with viral vectors in clinical studies. This study recombined amplified human retinal NT-3 with a eukaryotic expression plasmid containing green fluorescent protein (GFP) to construct an NT-3 expression plasmid, pEGFP-N1-NT-3. The transfection efficiency 48 hours after pEGFP-N1-NT-3 transfection to 293T cells was 50.06 ± 2.78%. Abundant NT-3-GFP was expressed in 293T cells as observed by fluorescence microscopy, suggesting the construct pEGFP-N1-NT-3 effectively expressed and secreted NT-3-GFP. Secretory vesicles containing NT-3-GFP were observed in a constant location in cells by laser scan confocal microscopy, indicating the expression and secretion processes of NT-3 in eukaryotic cells were in accordance with the physical synthesis processes of secreted proteins. Western blot assay showed that pro-NT-3-GFP had a molecular weight of 56 kDa, further confirming NT-3-GFP expression. At 48 hours after transfection, the concentration of NT-3 in culture medium was 22.3 ng/mL, suggesting NT-3 produced by pEGFP-N1-NT-3 was efficiently secreted. This study constructed a human retinal-derived NT-3 eukaryotic expression plasmid that efficiently expressed and secreted NT-3.
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Affiliation(s)
- Chunxia Peng
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Xiaobei Yin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Mengda Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Ting He
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing 100730, China
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Bramall AN, Szego MJ, Pacione LR, Chang I, Diez E, D'Orleans-Juste P, Stewart DJ, Hauswirth WW, Yanagisawa M, McInnes RR. Endothelin-2-mediated protection of mutant photoreceptors in inherited photoreceptor degeneration. PLoS One 2013; 8:e58023. [PMID: 23469133 PMCID: PMC3585171 DOI: 10.1371/journal.pone.0058023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 01/30/2013] [Indexed: 12/21/2022] Open
Abstract
Expression of the Endothelin-2 (Edn2) mRNA is greatly increased in the photoreceptors (PRs) of mouse models of inherited PR degeneration (IPD). To examine the role of Edn2 in mutant PR survival, we generated Edn2−/− mice carrying homozygous Pde6brd1 alleles or the Tg(RHO P347S) transgene. In the Edn2−/− background, PR survival increased 110% in Pde6brd1/rd1 mice at post-natal (PN) day 15, and 60% in Tg(RHO P347S) mice at PN40. In contrast, PR survival was not increased in retinal explants of Pde6brd1/rd1; Edn2−/− mice. This finding, together with systemic abnormalities in Edn2−/− mice, suggested that the increased survival of mutant PRs in the Edn2−/− background resulted at least partly from the systemic EDN2 loss of function. To examine directly the role of EDN2 in mutant PRs, we used a scAAV5-Edn2 cDNA vector to restore Edn2 expression in Pde6brd1/rd1; Edn2−/− PRs and observed an 18% increase in PR survival at PN14. Importantly, PR survival was also increased after injection of scAAV5-Edn2 into Pde6brd1/rd1 retinas, by 31% at PN15. Together, these findings suggest that increased Edn2 expression is protective to mutant PRs. To begin to elucidate Edn2-mediated mechanisms that contribute to PR survival, we used microarray analysis and identified a cohort of 20 genes with >4-fold increased expression in Tg(RHO P347S) retinas, including Fgf2. Notably, increased expression of the FGF2 protein in Tg(RHO P347S) PRs was ablated in Tg(RHO P347S); Edn2−/− retinas. Our findings indicate that the increased expression of PR Edn2 increases PR survival, and suggest that the Edn2-dependent increase in PR expression of FGF2 may contribute to the augmented survival.
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Affiliation(s)
- Alexa N. Bramall
- Program in Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Michael J. Szego
- Program in Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Laura R. Pacione
- Program in Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Inik Chang
- Department of Molecular Genetics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Eduardo Diez
- Lady Davis Research Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
| | - Pedro D'Orleans-Juste
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Duncan J. Stewart
- The Regenerative Medicine Program, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | - William W. Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Masashi Yanagisawa
- Department of Molecular Genetics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Roderick R. McInnes
- Program in Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lady Davis Research Institute, Jewish General Hospital, McGill University, Montreal, Quebec, Canada
- * E-mail:
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28
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Injury-independent induction of reactive gliosis in retina by loss of function of the LIM homeodomain transcription factor Lhx2. Proc Natl Acad Sci U S A 2012; 109:4657-62. [PMID: 22393024 DOI: 10.1073/pnas.1107488109] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Müller glia are the primary glial subtype in the retina and perform a wide range of physiological tasks in support of retinal function, but little is known about the transcriptional network that maintains these cells in their differentiated state. We report that selective deletion of the LIM homeodomain transcription factor Lhx2 from mature Müller glia leads to the induction of reactive retinal gliosis in the absence of injury. Furthermore, Lhx2 expression is also down-regulated in Prph2(Rd2/Rd2) animals immediately before the onset of reactive gliosis. Analysis of conditional Lhx2 knockouts showed that gliosis was hypertrophic but not proliferative. Aging of experimental animals demonstrated that constitutive reactive gliosis induced by deletion of Lhx2 reduced rates of ongoing apoptosis and compromised both rod and cone photoreceptor function. Additionally, these animals showed a dramatically reduced ability to induce expression of secreted neuroprotective factors and displayed enhanced rates of apoptosis in light-damage assays. We provide in vivo evidence that Lhx2 actively maintains mature Müller glia in a nonreactive state, with loss of function initiating a specific program of nonproliferative hypertrophic gliosis.
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Oliva AA, Kang Y, Sanchez-Molano J, Furones C, Atkins CM. STAT3 signaling after traumatic brain injury. J Neurochem 2012; 120:710-20. [PMID: 22145815 DOI: 10.1111/j.1471-4159.2011.07610.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Astrocytes respond to trauma by stimulating inflammatory signaling. In studies of cerebral ischemia and spinal cord injury, astrocytic signaling is mediated by the cytokine receptor glycoprotein 130 (gp130) and Janus kinase (Jak) which phosphorylates the transcription factor signal transducer and activator of transcription-3 (STAT3). To determine if STAT3 is activated after traumatic brain injury (TBI), adult male Sprague-Dawley rats received moderate parasagittal fluid-percussion brain injury or sham surgery, and then the ipsilateral cortex and hippocampus were analyzed at various post-traumatic time periods for up to 7 days. Western blot analyses indicated that STAT3 phosphorylation significantly increased at 30 min and lasted for 24 h post-TBI. A significant increase in gp130 and Jak2 phosphorylation was also observed. Confocal microscopy revealed that STAT3 was localized primarily within astrocytic nuclei. At 6 and 24 h post-TBI, there was also an increased expression of STAT3 pathway-related genes: suppressor of cytokine signaling 3, nitric oxide synthase 2, colony stimulating factor 2 receptor β, oncostatin M, matrix metalloproteinase 3, cyclin-dependent kinase inhibitor 1A, CCAAT/enhancer-binding protein β, interleukin-2 receptor γ, interleukin-4 receptor α, and α-2-macroglobulin. These results clarify some of the signaling pathways operative in astrocytes after TBI and demonstrate that the gp130-Jak2-STAT3 signaling pathway is activated after TBI in astrocytes.
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Affiliation(s)
- Anthony A Oliva
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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Li R, Wen R, Banzon T, Maminishkis A, Miller SS. CNTF mediates neurotrophic factor secretion and fluid absorption in human retinal pigment epithelium. PLoS One 2011; 6:e23148. [PMID: 21912637 PMCID: PMC3166283 DOI: 10.1371/journal.pone.0023148] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 07/07/2011] [Indexed: 12/14/2022] Open
Abstract
Ciliary neurotrophic factor (CNTF) protects photoreceptors and regulates their phototransduction machinery, but little is known about CNTF's effects on retinal pigment epithelial (RPE) physiology. Therefore, we determined the expression and localization of CNTF receptors and the physiological consequence of their activation in primary cultures of human fetal RPE (hfRPE). Cultured hfRPE express CNTF, CT1, and OsM and their receptors, including CNTFRα, LIFRβ, gp130, and OsMRβ, all localized mainly at the apical membrane. Exogenous CNTF, CT1, or OsM induces STAT3 phosphorylation, and OsM also induces the phosphorylation of ERK1/2 (p44/42 MAP kinase). CNTF increases RPE survivability, but not rates of phagocytosis. CNTF increases secretion of NT3 to the apical bath and decreases that of VEGF, IL8, and TGFβ2. It also significantly increases fluid absorption (JV) across intact monolayers of hfRPE by activating CFTR chloride channels at the basolateral membrane. CNTF induces profound changes in RPE cell biology, biochemistry, and physiology, including the increase in cell survival, polarized secretion of cytokines/neurotrophic factors, and the increase in steady-state fluid absorption mediated by JAK/STAT3 signaling. In vivo, these changes, taken together, could serve to regulate the microenvironment around the distal retinal/RPE/Bruch's membrane complex and provide protection against neurodegenerative disease.
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Affiliation(s)
- Rong Li
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rong Wen
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States of America
| | - Tina Banzon
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Arvydas Maminishkis
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sheldon S. Miller
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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