1
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Pazur E, Kalatanova A, Tasker NR, Vainionpää K, Leinonen H, Wipf P. Synthesis and Biological Analysis of Iso-dimethyltryptamines in a Model of Light-Induced Retinal Degeneration. ACS Med Chem Lett 2024; 15:1049-1056. [PMID: 39015263 PMCID: PMC11247652 DOI: 10.1021/acsmedchemlett.4c00130] [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: 03/21/2024] [Revised: 06/09/2024] [Accepted: 06/10/2024] [Indexed: 07/18/2024] Open
Abstract
Iso-dimethyltryptamine (isoDMT) analogues with heterocyclic substitutions at the indole C(3) were prepared in a hydrogen autotransfer alkylation and tested in combination with natural and unnatural clavine alkaloids in a model of light-induced retinal degeneration for protection against retinal degeneration. On the basis of measurements with optical coherence tomography and electroretinography, three compounds showed better efficacy than the positive control bromocriptine at equivalent systemically administered doses. These studies provide further insights into the role of serotonin receptors and their potential therapeutic applications in ocular diseases.
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Affiliation(s)
- Ethan
J. Pazur
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Anna Kalatanova
- Yliopistonrinne
3, Canthia, School of Pharmacy, University
of Eastern Finland, 70211 Kuopio, Finland
| | - Nikhil R. Tasker
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Katri Vainionpää
- Yliopistonrinne
3, Canthia, School of Pharmacy, University
of Eastern Finland, 70211 Kuopio, Finland
| | - Henri Leinonen
- Yliopistonrinne
3, Canthia, School of Pharmacy, University
of Eastern Finland, 70211 Kuopio, Finland
| | - Peter Wipf
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
- Yliopistonrinne
3, Canthia, School of Pharmacy, University
of Eastern Finland, 70211 Kuopio, Finland
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2
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Kaushik V, Dąbrowski M, Gessa L, Kumar N, Fernandes H. Two-photon excitation fluorescence in ophthalmology: safety and improved imaging for functional diagnostics. Front Med (Lausanne) 2024; 10:1293640. [PMID: 38235268 PMCID: PMC10791900 DOI: 10.3389/fmed.2023.1293640] [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: 09/13/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Two-photon excitation fluorescence (TPEF) is emerging as a powerful imaging technique with superior penetration power in scattering media, allowing for functional imaging of biological tissues at a subcellular level. TPEF is commonly used in cancer diagnostics, as it enables the direct observation of metabolism within living cells. The technique is now widely used in various medical fields, including ophthalmology. The eye is a complex and delicate organ with multiple layers of different cell types and tissues. Although this structure is ideal for visual perception, it generates aberrations in TPEF eye imaging. However, adaptive optics can now compensate for these aberrations, allowing for improved imaging of the eyes of animal models for human diseases. The eye is naturally built to filter out harmful wavelengths, but these wavelengths can be mimicked and thereby utilized in diagnostics via two-photon (2Ph) excitation. Recent advances in laser-source manufacturing have made it possible to minimize the exposure of in vivo measurements within safety, while achieving sufficient signals to detect for functional images, making TPEF a viable option for human application. This review explores recent advances in wavefront-distortion correction in animal models and the safety of use of TPEF on human subjects, both of which make TPEF a potentially powerful tool for ophthalmological diagnostics.
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Affiliation(s)
- Vineeta Kaushik
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Michał Dąbrowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Luca Gessa
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Nelam Kumar
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Humberto Fernandes
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
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3
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Rozanowska M, Edge R, Land EJ, Navaratnam S, Sarna T, Truscott TG. Scavenging of Cation Radicals of the Visual Cycle Retinoids by Lutein, Zeaxanthin, Taurine, and Melanin. Int J Mol Sci 2023; 25:506. [PMID: 38203675 PMCID: PMC10779001 DOI: 10.3390/ijms25010506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/26/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
In the retina, retinoids involved in vision are under constant threat of oxidation, and their oxidation products exhibit deleterious properties. Using pulse radiolysis, this study determined that the bimolecular rate constants of scavenging cation radicals of retinoids by taurine are smaller than 2 × 107 M-1s-1 whereas lutein scavenges cation radicals of all three retinoids with the bimolecular rate constants approach the diffusion-controlled limits, while zeaxanthin is only 1.4-1.6-fold less effective. Despite that lutein exhibits greater scavenging rate constants of retinoid cation radicals than other antioxidants, the greater concentrations of ascorbate in the retina suggest that ascorbate may be the main protectant of all visual cycle retinoids from oxidative degradation, while α-tocopherol may play a substantial role in the protection of retinaldehyde but is relatively inefficient in the protection of retinol or retinyl palmitate. While the protection of retinoids by lutein and zeaxanthin appears inefficient in the retinal periphery, it can be quite substantial in the macula. Although the determined rate constants of scavenging the cation radicals of retinol and retinaldehyde by dopa-melanin are relatively small, the high concentration of melanin in the RPE melanosomes suggests they can be scavenged if they are in proximity to melanin-containing pigment granules.
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Affiliation(s)
- Malgorzata Rozanowska
- Cardiff Institute of Tissue Engineering and Repair, Cardiff University, Cardiff CF10 3AX, UK
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK
| | - Ruth Edge
- Dalton Cumbrian Facility, The University of Manchester, Westlakes Science Park, Moor Row, Cumbria CA24 3HA, UK;
| | - Edward J. Land
- The Paterson Institute, The University of Manchester, Wilmslow Road, Manchester M20 4BX, UK;
| | - Suppiah Navaratnam
- Biomedical Sciences Research Institute, University of Salford, Manchester M5 4WT, UK;
| | - Tadeusz Sarna
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Krakow, Poland;
| | - T. George Truscott
- School of Chemical and Physical Sciences, Lennard-Jones Building, Keele University, Staffordshire ST5 5BG, UK;
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4
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Różanowska MB. Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina. Antioxidants (Basel) 2023; 12:2111. [PMID: 38136230 PMCID: PMC10740933 DOI: 10.3390/antiox12122111] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Lipofuscin accumulates with age as intracellular fluorescent granules originating from incomplete lysosomal digestion of phagocytosed and autophagocytosed material. The purpose of this review is to provide an update on the current understanding of the role of oxidative stress and/or lysosomal dysfunction in lipofuscin accumulation and its consequences, particularly for retinal pigment epithelium (RPE). Next, the fluorescence of lipofuscin, spectral changes induced by oxidation, and its contribution to retinal fluorescence are discussed. This is followed by reviewing recent developments in fluorescence imaging of the retina and the current evidence on the prognostic value of retinal fluorescence for the progression of age-related macular degeneration (AMD), the major blinding disease affecting elderly people in developed countries. The evidence of lipofuscin oxidation in vivo and the evidence of increased oxidative damage in AMD retina ex vivo lead to the conclusion that imaging of spectral characteristics of lipofuscin fluorescence may serve as a useful biomarker of oxidative damage, which can be helpful in assessing the efficacy of potential antioxidant therapies in retinal degenerations associated with accumulation of lipofuscin and increased oxidative stress. Finally, amendments to currently used fluorescence imaging instruments are suggested to be more sensitive and specific for imaging spectral characteristics of lipofuscin fluorescence.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, College of Biomedical and Life Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, Wales, UK;
- Cardiff Institute for Tissue Engineering and Repair (CITER), Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK
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5
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Palczewska G, Wojtkowski M, Palczewski K. From mouse to human: Accessing the biochemistry of vision in vivo by two-photon excitation. Prog Retin Eye Res 2023; 93:101170. [PMID: 36787681 PMCID: PMC10463242 DOI: 10.1016/j.preteyeres.2023.101170] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023]
Abstract
The eye is an ideal organ for imaging by a multi-photon excitation approach, because ocular tissues such as the sclera, cornea, lens and neurosensory retina, are highly transparent to infrared (IR) light. The interface between the retina and the retinal pigment epithelium (RPE) is especially informative, because it reflects the health of the visual (retinoid) cycle and its changes in response to external stress, genetic manipulations, and drug treatments. Vitamin A-derived retinoids, like retinyl esters, are natural fluorophores that respond to multi-photon excitation with near IR light, bypassing the filter-like properties of the cornea, lens, and macular pigments. Also, during natural aging some retinoids form bisretinoids, like diretinoid-pyridiniumethanolamine (A2E), that are highly fluorescent. These bisretinoids appear to be elevated concurrently with aging. Vitamin A-derived retinoids and bisretinoidss are detected by two-photon ophthalmoscopy (2PO), using a new class of light sources with adjustable spatial, temporal, and spectral properties. Furthermore, the two-photon (2P) absorption of IR light by the visual pigments in rod and cone photoreceptors can initiate visual transduction by cis-trans isomerization of retinal, enabling parallel functional studies. Recently we overcame concerns about safety, data interpretation and complexity of the 2P-based instrumentation, the major roadblocks toward advancing this modality to the clinic. These imaging and retina-function assessment advancements have enabled us to conduct the first 2P studies with humans.
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Affiliation(s)
- Grazyna Palczewska
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Polgenix, Inc., Department of Medical Devices, Cleveland, OH, USA; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland.
| | - Maciej Wojtkowski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland; Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; Department of Physiology & Biophysics, School of Medicine, And Chemistry, Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
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6
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Towards a New Biomarker for Diabetic Retinopathy: Exploring RBP3 Structure and Retinoids Binding for Functional Imaging of Eyes In Vivo. Int J Mol Sci 2023; 24:ijms24054408. [PMID: 36901838 PMCID: PMC10002987 DOI: 10.3390/ijms24054408] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/10/2023] [Accepted: 02/21/2023] [Indexed: 02/25/2023] Open
Abstract
Diabetic retinopathy (DR) is a severe disease with a growing number of afflicted patients, which places a heavy burden on society, both socially and financially. While there are treatments available, they are not always effective and are usually administered when the disease is already at a developed stage with visible clinical manifestation. However, homeostasis at a molecular level is disrupted before visible signs of the disease are evident. Thus, there has been a constant search for effective biomarkers that could signal the onset of DR. There is evidence that early detection and prompt disease control are effective in preventing or slowing DR progression. Here, we review some of the molecular changes that occur before clinical manifestations are observable. As a possible new biomarker, we focus on retinol binding protein 3 (RBP3). We argue that it displays unique features that make it a very good biomarker for non-invasive, early-stage DR detection. Linking chemistry to biological function and focusing on new developments in eye imaging and two-photon technology, we describe a new potential diagnostic tool that would allow rapid and effective quantification of RBP3 in the retina. Moreover, this tool would also be useful in the future to monitor therapeutic effectiveness if levels of RBP3 are elevated by DR treatments.
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7
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Chen C, Yang K, He D, Yang B, Tao L, Chen J, Wu Y. Induction of ferroptosis by HO-1 contributes to retinal degeneration in mice with defective clearance of all-trans-retinal. Free Radic Biol Med 2023; 194:245-254. [PMID: 36509314 DOI: 10.1016/j.freeradbiomed.2022.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
The accumulation of all-trans-retinal (atRAL) in photoreceptors and the retinal pigment epithelium (RPE), which is induced by chaos in visual (retinoid) cycle, is closely associated with the pathogenesis of dry age-related macular degeneration (AMD) and autosomal recessive Stargardt's disease (STGD1). Although we have reported that the induction of ferroptosis by atRAL is an important cause of photoreceptor loss, but its mechanisms still remain unclear. In this study, we identified heme oxygenase-1 (HO-1) as an inducer of photoreceptor ferroptosis elicited by atRAL. In atRAL-loaded photoreceptor cells, inhibition of Kelch-like ECH-associated protein 1 (KEAP1) at least in part by reactive oxygen species (ROS) production evoked the release of nuclear factor-erythroid 2-related factor-2 (NRF2) from KEAP1, followed by the translocation of active NRF2 into the nucleus where it promoted the transcription of the Ho-1 gene, thereby leading to HO-1 overexpression in the cytosol. A significant elevation of Fe2+ levels in photoreceptor cells resulted from activation of HO-1 by atRAL, and it facilitated ROS overproduction and then triggered ferroptotic cell death through ROS-mediated lipid peroxidation. Both treatment with HO-1 repressor Zinc protoporphyrin IX (ZnPP) and knockout of Ho-1 gene clearly rescued photoreceptor cells against ferroptosis arising from atRAL overload. Light-exposed Abca4-/-Rdh8-/- mice rapidly display severe defects in atRAL clearance, and serve as an acute model of dry AMD and STGD1. HO-1 activation was distinctly observed in neural retina of Abca4-/-Rdh8-/- mice after exposure to light, and it was visibly relieved by intraperitoneally injected ferroptosis inhibitor ferrostatin-1. More notably, intraperitoneal administration of ZnPP effectively alleviated both photoreceptor degeneration and RPE atrophy in Abca4-/-Rdh8-/- mice in response to light exposure by repressing HO-1-mediated ferroptosis. Our study suggests that HO-1 is a key factor that regulates atRAL-induced ferroptosis in photoreceptors and the RPE, and its inhibition may hold promises for the therapy of dry AMD and STGD1.
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Affiliation(s)
- Chao Chen
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China
| | - Kunhuan Yang
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China
| | - Danxue He
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China
| | - Bo Yang
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China
| | - Lei Tao
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China
| | - Jingmeng Chen
- School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China
| | - Yalin Wu
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102, Fujian, China; Shenzhen Research Institute of Xiamen University, Shenzhen, 518063, Guangdong, China; Xiamen Eye Center of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361001, Fujian, China.
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8
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Mavlyutov TA, Li J, Liu X, Shen H, Yang H, McCurdy CR, Pattnaik B, Guo LW. Retinal Photoreceptor Protection in an AMD-Related Mouse Model by Selective Sigma-1 or Sigma-2 Receptor Modulation. Genes (Basel) 2022; 13:2386. [PMID: 36553653 PMCID: PMC9778362 DOI: 10.3390/genes13122386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/04/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
The structurally and genetically distinct sigma-1 receptor (S1R) and sigma-2 receptor (S2R) comprise a unique class of drug binding sites. Their alleles are associated with human diseases involving neuronal systems, such as age-related macular degeneration (AMD) characterized by photoreceptor and retinal pigment epithelium (RPE) atrophy. Previous studies have suggested neuroprotective benefits for the brain and retina from pharmacological modulation of S1R and/or S2R. However, the effect of such modulation on AMD pathology remains underexplored. Here, we evaluated S1R- or S2R-selective modulation in an AMD-related model of Abca4-/-Rdh8-/- mice with a disrupted visual cycle that predisposes RPE and photoreceptors to illumination-induced damage. For S1R modulation, we used (+)-pentazocine, which is a high-affinity S1R-selective drug. For S2R modulation, we chose CM398, a high-affinity and highly S2R-selective ligand with drug-like properties. Abca4-/-Rdh8-/- mice received a single i.p. injection of (+)-pentazocine or CM398 or vehicle 30 min before illumination. Pretreatment with (+)-pentazocine improved electroretinogram a- and b-waves compared to that with vehicle. Consistently, in another AMD-related mouse model induced by tail-vein injected NaIO3, S1R genetic ablation aggravated photoreceptor loss. In Abca4-/-Rdh8-/- mice, pretreatment with CM398 appeared to partially avert illumination-induced photoreceptor loss and autofluorescent granule formation that signals RPE damage, as revealed by optical coherence tomography. Thus, this study using AMD-related models provides evidence of photoreceptor protection afforded by selective modulation of S1R or S2R.
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Affiliation(s)
| | - Jing Li
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Xinying Liu
- Department of Pediatrics, University of Wisconsin, Madison, WI 53705, USA
| | - Hongtao Shen
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
| | - Huan Yang
- Department of Surgery, University of Wisconsin, Madison, WI 53705, USA
| | - Christopher R. McCurdy
- Department of Medicinal Chemistry, College of Pharmacy, University of Florida, Gainesville, FL 32610, USA
| | - Bikash Pattnaik
- Department of Pediatrics, University of Wisconsin, Madison, WI 53705, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI 53705, USA
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705, USA
| | - Lian-Wang Guo
- Department of Surgery, University of Wisconsin, Madison, WI 53705, USA
- Department of Surgery, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI 53705, USA
- Department of Ophthalmology, School of Medicine, University of Virginia, Charlottesville, VA 22908, USA
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9
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Ortega JT, McKee AG, Roushar FJ, Penn WD, Schlebach JP, Jastrzebska B. Chromenone derivatives as novel pharmacological chaperones for retinitis pigmentosa-linked rod opsin mutants. Hum Mol Genet 2022; 31:3439-3457. [PMID: 35642742 PMCID: PMC9558842 DOI: 10.1093/hmg/ddac125] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/14/2022] Open
Abstract
The correct expression of folded, functional rhodopsin (Rho) is critical for visual perception. However, this seven-transmembrane helical G protein-coupled receptor is prone to mutations with pathological consequences of retinal degeneration in retinitis pigmentosa (RP) due to Rho misfolding. Pharmacological chaperones that stabilize the inherited Rho variants by assisting their folding and membrane targeting could slow the progression of RP. In this study, we employed virtual screening of synthetic compounds with a natural product scaffold in conjunction with in vitro and in vivo evaluations to discover a novel chromenone-containing small molecule with favorable pharmacological properties that stabilize rod opsin. This compound reversibly binds to unliganded bovine rod opsin with an EC50 value comparable to the 9-cis-retinal chromophore analog and partially rescued membrane trafficking of multiple RP-related rod opsin variants in vitro. Importantly, this novel ligand of rod opsin was effective in vivo in murine models, protecting photoreceptors from deterioration caused by either bright light or genetic insult. Together, our current study suggests potential broad therapeutic implications of the new chromenone-containing non-retinoid small molecule against retinal diseases associated with photoreceptor degeneration.
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Affiliation(s)
- Joseph T Ortega
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Andrew G McKee
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA
| | - Francis J Roushar
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA
| | - Wesley D Penn
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA
| | - Jonathan P Schlebach
- To whom correspondence should be addressed at: Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 441064965, USA. Tel: +1 2163685683; Fax: +1 2163681300; (Beata Jastrzebska); Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA. Tel: +1 812-855-6779; Fax: +1 812-855-8300; (Jonathan P. Schlebach)
| | - Beata Jastrzebska
- To whom correspondence should be addressed at: Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 441064965, USA. Tel: +1 2163685683; Fax: +1 2163681300; (Beata Jastrzebska); Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405-7102, USA. Tel: +1 812-855-6779; Fax: +1 812-855-8300; (Jonathan P. Schlebach)
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10
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Różanowska MB, Czuba-Pełech B, Różanowski B. Is There an Optimal Combination of AREDS2 Antioxidants Zeaxanthin, Vitamin E and Vitamin C on Light-Induced Toxicity of Vitamin A Aldehyde to the Retina? Antioxidants (Basel) 2022; 11:antiox11061132. [PMID: 35740030 PMCID: PMC9220409 DOI: 10.3390/antiox11061132] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/15/2022] [Accepted: 06/06/2022] [Indexed: 02/05/2023] Open
Abstract
Vitamins C and E and zeaxanthin are components of a supplement tested in a large clinical trial-Age-Related Eye Disease Study 2 (AREDS2)-and it has been demonstrated that they can inhibit the progression of age-related macular degeneration. The aim of this study was to determine the optimal combinations of these antioxidants to prevent the phototoxicity mediated by vitamin A aldehyde (ATR), which can accumulate in photoreceptor outer segments (POS) upon exposure to light. We used cultured retinal pigment epithelial cells ARPE-19 and liposomes containing unsaturated lipids and ATR as a model of POS. Cells and/or liposomes were enriched with lipophilic antioxidants, whereas ascorbate was added just before the exposure to light. Supplementing the cells and/or liposomes with single lipophilic antioxidants had only a minor effect on phototoxicity, but the protection substantially increased in the presence of both ways of supplementation. Combinations of zeaxanthin with α-tocopherol in liposomes and cells provided substantial protection, enhancing cell viability from ~26% in the absence of antioxidants to ~63% in the presence of 4 µM zeaxanthin and 80 µM α-tocopherol, and this protective effect was further increased to ~69% in the presence of 0.5 mM ascorbate. The protective effect of ascorbate disappeared at a concentration of 1 mM, whereas 2 mM of ascorbate exacerbated the phototoxicity. Zeaxanthin or α-tocopherol partly ameliorated the cytotoxic effects. Altogether, our results suggest that the optimal combination includes upper levels of zeaxanthin and α-tocopherol achievable by diet and/or supplementations, whereas ascorbate needs to be at a four-fold smaller concentration than that in the vitreous. The physiological relevance of the results is discussed.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, Wales, UK
- Cardiff Institute for Tissue Engineering and Repair (CITER), Cardiff University, Cardiff CF24 4HQ, Wales, UK
- Correspondence: ; Tel.: +44-292087-5057
| | - Barbara Czuba-Pełech
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland;
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11
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Lewandowski D, Foik AT, Smidak R, Choi EH, Zhang J, Hoang T, Tworak A, Suh S, Leinonen H, Dong Z, Pinto AF, Tom E, Luu JC, Lee JY, Ma X, Bieberich E, Blackshaw S, Saghatelian A, Lyon DC, Skowronska-Krawczyk D, Tabaka M, Palczewski K. Inhibition of ceramide accumulation in AdipoR1-/- mice increases photoreceptor survival and improves vision. JCI Insight 2022; 7:156301. [PMID: 35015730 PMCID: PMC8876453 DOI: 10.1172/jci.insight.156301] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/05/2022] [Indexed: 11/20/2022] Open
Abstract
Adiponectin receptor 1 (ADIPOR1) is a lipid and glucose metabolism regulator that possesses intrinsic ceramidase activity. Mutations of the ADIPOR1 gene have been associated with nonsyndromic and syndromic retinitis pigmentosa. Here, we show that the absence of AdipoR1 in mice leads to progressive photoreceptor degeneration, significant reduction of electroretinogram amplitudes, decreased retinoid content in the retina, and reduced cone opsin expression. Single-cell RNA-Seq results indicate that ADIPOR1 encoded the most abundantly expressed ceramidase in mice and one of the 2 most highly expressed ceramidases in the human retina, next to acid ceramidase ASAH1. We discovered an accumulation of ceramides in the AdipoR1–/– retina, likely due to insufficient ceramidase activity for healthy retina function, resulting in photoreceptor death. Combined treatment with desipramine/L-cycloserine (DC) lowered ceramide levels and exerted a protective effect on photoreceptors in AdipoR1–/– mice. Moreover, we observed improvement in cone-mediated retinal function in the DC-treated animals. Lastly, we found that prolonged DC treatment corrected the electrical responses of the primary visual cortex to visual stimuli, approaching near-normal levels for some parameters. These results highlight the importance of ADIPOR1 ceramidase in the retina and show that pharmacological inhibition of ceramide generation can provide a therapeutic strategy for ADIPOR1-related retinopathy.
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Affiliation(s)
- Dominik Lewandowski
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Andrzej T Foik
- International Center for Translational Eye Research, Institute of Physical Chemistry PAS, Warsaw, Poland
| | - Roman Smidak
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Elliot H Choi
- Department of Pharmacology, Case Western Reserve University, Cleveland, United States of America
| | - Jianye Zhang
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Thanh Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States of America
| | - Aleksander Tworak
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Susie Suh
- Department of Pharmacology, Case Western Reserve University, Cleveland, United States of America
| | - Henri Leinonen
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Zhiqian Dong
- Department of Medical Devices, Polgenix Inc., Cleveland, United States of America
| | - Antonio Fm Pinto
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, United States of America
| | - Emily Tom
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Jennings C Luu
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
| | - Joan Y Lee
- MetroHealth Medical Center, Case Western Reserve University, Cleveland, United States of America
| | - Xiuli Ma
- Department of Medical Devices, Polgenix Inc, Cleveland, United States of America
| | - Erhard Bieberich
- Department of Physiology, University of Kentucky, Lexington, United States of America
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, John Hopkins School of Medicine, Baltimore, United States of America
| | - Alan Saghatelian
- Clayton Foundation Laboratories for Peptide Biology, Salk Institute for Biological Studies, La Jolla, United States of America
| | - David C Lyon
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, United States of America
| | | | - Marcin Tabaka
- International Center for Translational Eye Research, Institute of Physical Chemistry PAS, Warsaw, Poland
| | - Krzysztof Palczewski
- Department of Ophthalmology, University of California, Irvine, Irvine, United States of America
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12
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Tao L, He D, Liao C, Cai B, Chen C, Wang Y, Chen J, Liu Z, Wu Y. Repressing c-Jun N-terminal kinase signaling mitigates retinal pigment epithelium degeneration in mice with failure to clear all-trans-retinal. Exp Eye Res 2021; 214:108877. [PMID: 34863682 DOI: 10.1016/j.exer.2021.108877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 11/04/2021] [Accepted: 11/29/2021] [Indexed: 11/04/2022]
Abstract
Retinal pigment epithelium (RPE) cell apoptosis arising from all-trans-retinal (atRAL) is in close contact with the etiology of dry age-related macular degeneration (AMD) and autosomal recessive Stargardt's disease (STGD1), but its underlying mechanisms remain elusive. In this study, we reported that c-Jun N-terminal kinase (JNK) activation facilitated atRAL-induced apoptosis of RPE cells. Reactive oxygen species production and endoplasmic reticulum stress were identified as two of major upstream events responsible for activating JNK signaling in atRAL-loaded RPE cells. Inhibiting JNK signaling rescued RPE cells from apoptosis induced by atRAL through attenuating caspase-3 activation leading to poly-ADP-ribose polymerase (PARP) cleavage, and DNA damage response. Abca4-/-Rdh8-/- mice upon light exposure exhibit rapidly increased accumulation of atRAL in the retina, and display severe RPE degeneration, a primary attribute of dry AMD and STGD1. Reducing JNK signaling by intraperitoneally injected JNK-IN-8 was highly effective in preventing RPE atrophy and apoptosis in light-exposed Abca4-/-Rdh8-/- mice. These findings afford a further understanding for contribution of JNK activation by atRAL to retinal damage.
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Affiliation(s)
- Lei Tao
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Danxue He
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Chunyan Liao
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Binxiang Cai
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Chao Chen
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yan Wang
- Department of Ophthalmology, South China Hospital, Health Science Center, Shenzhen University, Shenzhen, Guangdong, China
| | - Jingmeng Chen
- School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Zuguo Liu
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Yalin Wu
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Fujian Engineering and Research Center of Eye Regenerative Medicine, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China; Xiamen Eye Center of Xiamen University, Xiamen, Fujian, China; Shenzhen Research Institute of Xiamen University, Shenzhen, Guangdong, China.
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13
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Chudhary M, Zhang C, Song S, Ren X, Kong L. Ginkgo biloba delays light-induced photoreceptor degeneration through antioxidant and antiapoptotic properties. Exp Ther Med 2021; 21:576. [PMID: 33850548 DOI: 10.3892/etm.2021.10008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 02/05/2021] [Indexed: 02/06/2023] Open
Abstract
Intense exposure to artificial bright light increases the risk of retinal damage resulting in blurred vision and blindness. Long-term exposure to bright light elevates oxidative stress-induced apoptosis, which results in photoreceptor cell degeneration. However, to the best of our knowledge, the molecular mechanism associated with light-induced retinopathy remains unclear. In the present study, the mechanisms involved in light-induced oxidative stress and apoptosis were investigated along with the protective effects of Ginkgo biloba (EGb 761) in photoreceptor cell degeneration. EGb 761 was administered to mice at a dose of 50 or 100 mg/kg for 7 days prior to exposure to bright light (5,000 lux for 24 h). Furthermore, photoreceptor cell disorders were evaluated using electroretinogram (ERG) and H&E staining analyses. The expression levels of antioxidant genes and proteins ERK, thioredoxin (Trx) and nuclear factor erythroid 2-related factor 2 (Nrf-2) and the induction of apoptosis cytochrome c (Cyc), cleaved caspase-3 and Bax, were determined by reverse transcription-quantitative PCR and western blotting. ERG and histological analysis revealed that exposure to bright light induced functional and morphological changes to the photoreceptor cells. Exposure to bright light increased the levels of Cyc, cleaved caspase-3 and Bax, and decreased the levels of phosphorylated (p-) Erk, Nrf-2 and thioredoxin (Trx). However, treatment of mice with EGb 761 increased the expression levels of antiapoptotic (Bcl-2) and antioxidant (p-Erk, Trx and Nrf-2) proteins and decreased the expression levels of the apoptotic genes (Cyc, cleaved caspase-3 and Bax). Based on these findings, the present study suggested that prolonged exposure to light induces photoreceptor cell degeneration, where EGb 761 treatment may serve a therapeutic effect on the development of photoreceptor cell degeneration.
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Affiliation(s)
- Maryam Chudhary
- Department of Histology and Embryology, College of Basic Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Chenghong Zhang
- Teaching Laboratory of Morphology, College of Basic Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Shiyu Song
- Department of Histology and Embryology, College of Basic Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Xiang Ren
- Department of Histology and Embryology, College of Basic Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
| | - Li Kong
- Department of Histology and Embryology, College of Basic Medicine, Dalian Medical University, Dalian, Liaoning 116044, P.R. China
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14
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Chen C, Chen J, Wang Y, Liu Z, Wu Y. Ferroptosis drives photoreceptor degeneration in mice with defects in all-trans-retinal clearance. J Biol Chem 2020; 296:100187. [PMID: 33334878 PMCID: PMC7948481 DOI: 10.1074/jbc.ra120.015779] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/30/2020] [Accepted: 12/14/2020] [Indexed: 12/21/2022] Open
Abstract
The death of photoreceptor cells in dry age-related macular degeneration (AMD) and autosomal recessive Stargardt disease (STGD1) is closely associated with disruption in all-trans-retinal (atRAL) clearance in neural retina. In this study, we reveal that the overload of atRAL leads to photoreceptor degeneration through activating ferroptosis, a nonapoptotic form of cell death. Ferroptosis of photoreceptor cells induced by atRAL resulted from increased ferrous ion (Fe2+), elevated ACSL4 expression, system Xc- inhibition, and mitochondrial destruction. Fe2+ overload, tripeptide glutathione (GSH) depletion, and damaged mitochondria in photoreceptor cells exposed to atRAL provoked reactive oxygen species (ROS) production, which, together with ACSL4 activation, promoted lipid peroxidation and thereby evoked ferroptotic cell death. Moreover, exposure of photoreceptor cells to atRAL activated COX2, a well-accepted biomarker for ferroptosis onset. In addition to GSH supplement, inhibiting either Fe2+ by deferoxamine mesylate salt (DFO) or lipid peroxidation with ferrostatin-1 (Fer-1) protected photoreceptor cells from ferroptosis caused by atRAL. Abca4-/-Rdh8-/- mice exhibiting defects in atRAL clearance is an animal model for dry AMD and STGD1. We observed that ferroptosis was indeed present in neural retina of Abca4-/-Rdh8-/- mice after light exposure. More importantly, photoreceptor atrophy and ferroptosis in light-exposed Abca4-/-Rdh8-/- mice were effectively alleviated by intraperitoneally injected Fer-1, a selective inhibitor of ferroptosis. Our study suggests that ferroptosis is one of the important pathways of photoreceptor cell death in retinopathies arising from excess atRAL accumulation and should be pursued as a novel target for protection against dry AMD and STGD1.
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Affiliation(s)
- Chao Chen
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen City, Fujian, China
| | - Jingmeng Chen
- School of Medicine, Xiamen University, Xiamen City, Fujian, China
| | - Yan Wang
- Department of Ophthalmology, Shenzhen Hospital, Southern Medical University, Shenzhen City, Guangdong, China
| | - Zuguo Liu
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen City, Fujian, China
| | - Yalin Wu
- Fujian Provincial Key Laboratory of Ophthalmology and Visual Science, Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen City, Fujian, China; Xiamen Eye Center of Xiamen University, Xiamen City, Fujian, China; Shenzhen Research Institute of Xiamen University, Shenzhen City, Guangdong, China.
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15
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Ortega JT, Parmar T, Golczak M, Jastrzebska B. Protective Effects of Flavonoids in Acute Models of Light-Induced Retinal Degeneration. Mol Pharmacol 2020; 99:60-77. [PMID: 33154094 DOI: 10.1124/molpharm.120.000072] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/26/2020] [Indexed: 12/17/2022] Open
Abstract
Degeneration of photoreceptors caused by excessive illumination, inherited mutations, or aging is the principal pathology of blinding diseases. Pharmacological compounds that stabilize the visual receptor rhodopsin and modulate the cellular pathways triggering death of photoreceptors could avert this pathology. Interestingly, flavonoids can modulate the cellular processes, such as oxidative stress, inflammatory responses, and apoptosis, that are activated during retinal degeneration. As we found previously, flavonoids also bind directly to unliganded rod opsin, enhancing its folding, stability, and regeneration. In addition, flavonoids stimulate rhodopsin gene expression. Thus, we evaluated the effect of two main dietary flavonoids, quercetin and myricetin, in ATP-binding cassette subfamily A member 4 -/- /retinol dehydrogenase 8 -/- and wild-type BALB/c mice susceptible to light-induced photoreceptor degeneration. Using in vivo imaging, such as optical coherence tomography, scanning laser ophthalmoscopy, and histologic assessment of retinal morphology, we found that treatment with these flavonoids prior to light insult remarkably protected retina from deterioration and preserved its function. Using high-performance liquid chromatography-mass spectrometry analysis, we detected these flavonoids in the eye upon their intraperitoneal administration. The molecular events associated with the protective effect of quercetin and myricetin were related to the elevated expression of photoreceptor-specific proteins, rhodopsin and cone opsins, decreased expression of the specific inflammatory markers, and the shift of the equilibrium between cell death regulators BCL2-associated X protein (BAX) and B-cell lymphoma 2 toward an antiapoptotic profile. These results were confirmed in photoreceptor-derived 661W cells treated with either H2O2 or all-trans-retinal stressors implicated in the mechanism of retinal degeneration. Altogether, flavonoids could have significant prophylactic value for retinal degenerative diseases. SIGNIFICANCE STATEMENT: Flavonoids commonly present in food exhibit advantageous effects in blinding diseases. They bind to and stabilize unliganded rod opsin, which in excess accelerates degenerative processes in the retina. Additionally, flavonoids enhance the expression of the visual receptors, rod and cone opsins; inhibit the inflammatory reactions; and induce the expression of antiapoptotic markers in the retina, preventing the degeneration in vivo. Thus, flavonoids could have a prophylactic value for retinal degenerative diseases.
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Affiliation(s)
- Joseph T Ortega
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Tanu Parmar
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Marcin Golczak
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Beata Jastrzebska
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
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16
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Abstract
High-resolution imaging techniques capable of detecting identifiable endogenous fluorophores in the eye along with genetic testing will dramatically improve diagnostic capabilities in the ophthalmology clinic and accelerate the development of new treatments for blinding diseases. Two-photon excitation (TPE)-based imaging overcomes the filtering of ultraviolet light by the lens of the human eye and thus can be utilized to discover defects in vitamin A metabolism during the regeneration of the visual pigments required for the detection of light. Combining TPE with fluorescence lifetime imaging (FLIM) and spectral analyses offers the potential of detecting diseases of the retina at earlier stages before irreversible structural damage has occurred. The main barriers to realizing the benefits of TPE for imaging the human retina arise from concerns about the high light exposure typically needed for informative TPE imaging and the requirement to correlate the ensuing data with different states of health and disease. To overcome these hurdles, we improved TPE efficiency by controlling temporal properties of the excitation light and employed phasor analyses to FLIM and spectral data in mouse models of retinal diseases. Modeling of retinal photodamage revealed that plasma-mediated effects do not play a role and that melanin-related thermal effects are mitigated by reducing pulse repetition frequency. By using noninvasive TPE imaging we identified molecular components of individual granules in the retinal pigment epithelium and present their analytical characteristics.
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17
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Olchawa M, Krzysztynska-Kuleta O, Duda M, Pawlak A, Pabisz P, Czuba-Pelech B, Sarna T. In vitro phototoxicity of rhodopsin photobleaching products in the retinal pigment epithelium (RPE). Free Radic Res 2019; 53:456-471. [DOI: 10.1080/10715762.2019.1603377] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Magdalena Olchawa
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Olga Krzysztynska-Kuleta
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
- Laboratory of Imaging and Atomic Force Spectroscopy, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Mariusz Duda
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
- Laboratory of Imaging and Atomic Force Spectroscopy, Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Anna Pawlak
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Pawel Pabisz
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Barbara Czuba-Pelech
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
| | - Tadeusz Sarna
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Biophysics, Jagiellonian University, Kraków, Poland
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18
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Maeda A, Mandai M, Takahashi M. Gene and Induced Pluripotent Stem Cell Therapy for Retinal Diseases. Annu Rev Genomics Hum Genet 2019; 20:201-216. [PMID: 31018110 DOI: 10.1146/annurev-genom-083118-015043] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Given the importance of visual information to many daily activities, retinal degenerative diseases-which include both inherited conditions (such as retinitis pigmentosa) and acquired conditions (such as age-related macular degeneration)-can have a dramatic impact on human lives. The therapeutic options for these diseases remain limited. Since the discovery of the first causal gene for retinitis pigmentosa almost three decades ago, more than 250 genes have been identified, and gene therapies have been rapidly developed. Simultaneously, stem cell technologies such as induced pluripotent stem cell-based transplantation have advanced and have been applied to the treatment of retinal degenerative diseases. Here, we review recent progress in these expanding fields and discuss the potential for precision medicine in ophthalmic care.
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Affiliation(s)
- Akiko Maeda
- Laboratory for Retinal Regeneration, Center for Biosystems Dynamics Research, RIKEN, Kobe, Hyogo 650-0047, Japan;
| | - Michiko Mandai
- Laboratory for Retinal Regeneration, Center for Biosystems Dynamics Research, RIKEN, Kobe, Hyogo 650-0047, Japan;
| | - Masayo Takahashi
- Laboratory for Retinal Regeneration, Center for Biosystems Dynamics Research, RIKEN, Kobe, Hyogo 650-0047, Japan; .,Kobe City Eye Center Hospital, Kobe, Hyogo 650-0047, Japan
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19
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Miura Y. Two-Photon Microscopy (TPM) and Fluorescence Lifetime Imaging Microscopy (FLIM) of Retinal Pigment Epithelium (RPE) of Mice In Vivo. Methods Mol Biol 2019; 1753:73-88. [PMID: 29564782 DOI: 10.1007/978-1-4939-7720-8_5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Retinal pigment epithelium (RPE), a monolayer of epithelial cells located between the neural retina and the choroid, plays a significant role in the maintenance of retinal function. Its in vivo imaging is still technically challenging in human eye. With the mouse eye, there is a possibility to look into the RPE through the sclera using two-photon microscopy (TPM). TPM is a two photon-excited nonlinear fluorescence microscopy that enables the observation of deep tissues up to several hundred micrometers. Since the simultaneous absorption of two photons occurs only at the focal plane, spatial resolution of the TPM is quite high, such that pinhole as used in a confocal microscope is not necessary. TPM enables observation of autofluorescence at the cellular level, and thus may provide new insights into the fluorescent molecules in/around RPE cells.The combination of TPM with fluorescence lifetime imaging microscopy (FLIM) may expand the breadth of information about cells and tissues. Fluorescence lifetime is a fluorophore-specific property, which is independent of fluorescence intensity and changes with the alteration of molecular environment. FLIM may have therefore the potentials to distinguish different fluorophores and to indicate the change in the environment of a fluorophore. Some energy metabolisms-related intracellular fluorophores, such as NADH (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide), show characteristic fluorescence lifetimes that shift under different molecular environments, and thus their fluorescence lifetime have been used to indicate cell energy metabolic states. These nonlabeling imaging methods offer us the opportunity to engage in the study of the RPE in vivo as well as in vitro both in morphological as well as metabolic aspects.
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Affiliation(s)
- Yoko Miura
- Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany. .,Department of Ophthalmology, University of Lübeck, Lübeck, Germany.
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20
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Noninvasive Two-Photon Microscopy Imaging of Mouse Retina and Retinal Pigment Epithelium. Methods Mol Biol 2019; 1834:333-343. [PMID: 30324453 DOI: 10.1007/978-1-4939-8669-9_21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Two-photon excitation microscopy is perfectly suited for imaging deep into the retina due to its use of infrared (IR) wavelengths to excite endogenous fluorophores such as vitamin A-derived retinoids present in this tissue. Furthermore, two-photon excitation occurs only around a small focal volume, and scattered IR photons cannot excite retinal chromophores. These characteristics contribute to subcellular resolution and low noise of images obtained from deep within retinal layers. Here we describe how to customize a two-photon microscope for noninvasive imaging of the retina and retinal pigment epithelium (RPE) in the mouse eye, along with detailed instructions for mouse handling and retinal imaging, and we provide examples of mouse retinal two-photon microscopy data.
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21
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Palczewska G, Stremplewski P, Suh S, Alexander N, Salom D, Dong Z, Ruminski D, Choi EH, Sears AE, Kern TS, Wojtkowski M, Palczewski K. Two-photon imaging of the mammalian retina with ultrafast pulsing laser. JCI Insight 2018; 3:121555. [PMID: 30185665 DOI: 10.1172/jci.insight.121555] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/24/2018] [Indexed: 12/13/2022] Open
Abstract
Noninvasive imaging of visual system components in vivo is critical for understanding the causal mechanisms of retinal diseases and for developing therapies for their treatment. However, ultraviolet light needed to excite endogenous fluorophores that participate in metabolic processes of the retina is highly attenuated by the anterior segment of the human eye. In contrast, 2-photon excitation fluorescence imaging with pulsed infrared light overcomes this obstacle. Reducing retinal exposure to laser radiation remains a major barrier in advancing this technology to studies in humans. To increase fluorescence intensity and reduce the requisite laser power, we modulated ultrashort laser pulses with high-order dispersion compensation and applied sensorless adaptive optics and custom image recovery software and observed an over 300% increase in fluorescence of endogenous retinal fluorophores when laser pulses were shortened from 75 fs to 20 fs. No functional or structural changes to the retina were detected after exposure to 2-photon excitation imaging light with 20-fs pulses. Moreover, wide bandwidth associated with short pulses enables excitation of multiple fluorophores with different absorption spectra and thus can provide information about their relative changes and intracellular distribution. These data constitute a substantial advancement for safe 2-photon fluorescence imaging of the human eye.
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Affiliation(s)
| | - Patrycjusz Stremplewski
- Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Susie Suh
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Nathan Alexander
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - David Salom
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Zhiqian Dong
- Polgenix, Inc., Department of Medical Devices, Cleveland, Ohio, USA
| | - Daniel Ruminski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Elliot H Choi
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Avery E Sears
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Timothy S Kern
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Maciej Wojtkowski
- Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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22
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Gao S, Parmar T, Palczewska G, Dong Z, Golczak M, Palczewski K, Jastrzebska B. Protective Effect of a Locked Retinal Chromophore Analog against Light-Induced Retinal Degeneration. Mol Pharmacol 2018; 94:1132-1144. [PMID: 30018116 DOI: 10.1124/mol.118.112581] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 07/11/2018] [Indexed: 01/10/2023] Open
Abstract
Continuous regeneration of the 11-cis-retinal visual chromophore from all-trans-retinal is critical for vision. Insufficiency of 11-cis-retinal arising from the dysfunction of key proteins involved in its regeneration can impair retinal health, ultimately leading to loss of human sight. Delayed recovery of visual sensitivity and night blindness caused by inadequate regeneration of the visual pigment rhodopsin are typical early signs of this condition. Excessive concentrations of unliganded, constitutively active opsin and increased levels of all-trans-retinal and its byproducts in photoreceptors also accelerate retinal degeneration after light exposure. Exogenous 9-cis-retinal iso-chromophore can reduce the toxicity of ligand-free opsin but fails to prevent the buildup of retinoid photoproducts when their clearance is defective in human retinopathies, such as Stargardt disease or age-related macular degeneration. Here we evaluated the effect of a locked chromophore analog, 11-cis-6-membered ring-retinal against bright light-induced retinal degeneration in Abca4-/-Rdh8-/- mice. Using in vivo imaging techniques, optical coherence tomography, scanning laser ophthalmoscopy, and two-photon microscopy, along with in vitro histologic analysis of retinal morphology, we found that treatment with 11-cis-6-membered ring-retinal before light stimulation prevented rod and cone photoreceptor degradation and preserved functional acuity in these mice. Moreover, additive accumulation of 11-cis-6-membered ring-retinal measured in the eyes of these mice by quantitative liquid chromatography-mass spectrometry indicated stable binding of this retinoid to opsin. Together, these results suggest that eliminating excess of unliganded opsin can prevent light-induced retinal degeneration in Abca4-/-Rdh8-/- mice.
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Affiliation(s)
- Songqi Gao
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Tanu Parmar
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Grazyna Palczewska
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Zhiqian Dong
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
| | - Beata Jastrzebska
- Department of Pharmacology, School of Medicine (S.G., T.P., M.G., K.P., B.J.) and Cleveland Center for Membrane and Structural Biology (M.G., K.P., B.J.), Case Western Reserve University, and Polgenix Inc., Department of Medical Devices (G.P., Z.D.), Cleveland, Ohio
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Antioxidant effects of Lycium barbarum polysaccharides on photoreceptor degeneration in the light-exposed mouse retina. Biomed Pharmacother 2018; 103:829-837. [PMID: 29684862 DOI: 10.1016/j.biopha.2018.04.104] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/12/2018] [Accepted: 04/13/2018] [Indexed: 01/05/2023] Open
Abstract
We assessed the neuroprotective effects of Lycium barbarum Polysaccharides (LBP) on photoreceptor degeneration and the mechanisms involved in oxidative stress in light-exposed mouse retinas. Mice were given a gavage of LBP (150 mg/kg or 300 mg/kg) or phosphate buffered saline (PBS) for 7 days before exposure to light (5000 lx for 24 h). We found that LBP significantly improved the electroretinography (ERG) amplitudes of the a- and b-waves that had been attenuated by light exposure. In addition, changes caused by light exposure including photoreceptor cell loss, nuclear condensation, an increased number of mitochondria vacuoles, outer membrane disc swelling and cristae fractures were distinctly ameliorated by LBP. LBP treatment also significantly prevented the generation of reactive oxygen species (ROS) compared with PBS treatment. The levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and thioredoxin reductase (TrxR1) mRNA were decreased in PBS-treated mice compared with controls but increased remarkably in LBP-treated mice. The mRNA levels of the DNA repair gene Poly (ADP-ribose) polymerase (PARP14) was increased in PBS-treated mice but decreased significantly in the LBP-treated mice. Our findings indicate that pretreatment with LBP effectively protected photoreceptor cells against light-induced retinal damage probably through the up-regulation of the antioxidative genes Nrf2 and TrxR1, the elimination of oxygen free radicals, and the subsequent reduction in the mitochondrial reaction to oxidative stress and enhancement in antioxidant capacity. In addition, the decreased level of PARP14 mRNA in LBP-treated mice also indicated a protective effect of LBP on delaying photoreceptor in the light-damaged retina.
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Parmar T, Parmar VM, Perusek L, Georges A, Takahashi M, Crabb JW, Maeda A. Lipocalin 2 Plays an Important Role in Regulating Inflammation in Retinal Degeneration. THE JOURNAL OF IMMUNOLOGY 2018; 200:3128-3141. [PMID: 29602770 DOI: 10.4049/jimmunol.1701573] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 03/05/2018] [Indexed: 12/17/2022]
Abstract
It has become increasingly important to understand how retinal inflammation is regulated because inflammation plays a role in retinal degenerative diseases. Lipocalin 2 (LCN2), an acute stress response protein with multiple innate immune functions, is increased in ATP-binding cassette subfamily A member 4 (Abca4) -/- retinol dehydrogenase 8 (Rdh8) -/- double-knockout mice, an animal model for Stargardt disease and age-related macular degeneration (AMD). To examine roles of LCN2 in retinal inflammation and degeneration, Lcn2-/-Abca4-/-Rdh8-/- triple-knockout mice were generated. Exacerbated inflammation following light exposure was observed in Lcn2-/-Abca4-/-Rdh8-/- mice as compared with Abca4-/-Rdh8-/- mice, with upregulation of proinflammatory genes and microglial activation. RNA array analyses revealed an increase in immune response molecules such as Ccl8, Ccl2, and Cxcl10 To further probe a possible regulatory role for LCN2 in retinal inflammation, we examined the in vitro effects of LCN2 on NF-κB signaling in human retinal pigmented epithelial (RPE) cells differentiated from induced pluripotent stem cells derived from healthy donors. We found that LCN2 induced expression of antioxidant enzymes heme oxygenase 1 and superoxide dismutase 2 in these RPE cells and could inhibit the cytotoxic effects of H2O2 and LPS. ELISA revealed increased LCN2 levels in plasma of patients with Stargardt disease, retinitis pigmentosa, and age-related macular degeneration as compared with healthy controls. Finally, overexpression of LCN2 in RPE cells displayed protection from cell death. Overall these results suggest that LCN2 is involved in prosurvival responses during cell stress and plays an important role in regulating inflammation during retinal degeneration.
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Affiliation(s)
- Tanu Parmar
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106
| | - Vipul M Parmar
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106
| | - Lindsay Perusek
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106
| | - Anouk Georges
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan
| | - Masayo Takahashi
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan
| | - John W Crabb
- Cole Eye Institute, Cleveland Clinic, OH 44195; and
| | - Akiko Maeda
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106; .,Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan.,Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106
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In vivo two-photon imaging of retina in rabbits and rats. Exp Eye Res 2018; 166:40-48. [DOI: 10.1016/j.exer.2017.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/25/2017] [Accepted: 04/25/2017] [Indexed: 11/21/2022]
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Sharma R, Schwarz C, Hunter JJ, Palczewska G, Palczewski K, Williams DR. Formation and Clearance of All-Trans-Retinol in Rods Investigated in the Living Primate Eye With Two-Photon Ophthalmoscopy. Invest Ophthalmol Vis Sci 2017; 58:604-613. [PMID: 28129424 PMCID: PMC5283085 DOI: 10.1167/iovs.16-20061] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Two-photon excited fluorescence (TPEF) imaging has potential as a functional tool for tracking visual pigment regeneration in the living eye. Previous studies have shown that all-trans-retinol is likely the chief source of time-varying TPEF from photoreceptors. Endogenous TPEF from retinol could provide the specificity desired for tracking the visual cycle. However, in vivo characterization of native retinol kinetics is complicated by visual stimulation from the imaging beam. We have developed an imaging scheme for overcoming these challenges and monitored the formation and clearance of retinol. Methods Three macaques were imaged by using an in vivo two-photon ophthalmoscope. Endogenous TPEF was excited at 730 nm and recorded through the eye's pupil for more than 90 seconds. Two-photon excited fluorescence increased with onset of light and plateaued within 40 seconds, at which point, brief incremental stimuli were delivered at 561 nm. The responses of rods to stimulation were analyzed by using first-order kinetics. Results Two-photon excited fluorescence resulting from retinol production corresponded to the fraction of rhodopsin bleached. The photosensitivity of rhodopsin was estimated to be 6.88 ± 5.50 log scotopic troland. The rate of retinol clearance depended on intensity of incremental stimulation. Clearance was faster for stronger stimuli and time constants ranged from 50 to 300 seconds. Conclusions This study demonstrates a method for rapidly measuring the rate of clearance of retinol in vivo. Moreover, TPEF generated due to retinol can be used as a measure of rhodopsin depletion, similar to densitometry. This enhances the utility of two-photon ophthalmoscopy as a technique for evaluating the visual cycle in the living eye.
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Affiliation(s)
- Robin Sharma
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Christina Schwarz
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Jennifer J Hunter
- Center for Visual Science, University of Rochester, Rochester, New York, United States 2Flaum Eye Institute, University of Rochester, Rochester, New York, United States 3Biomedical Engineering, University of Rochester, Rochester, New York, United States
| | | | - Krzysztof Palczewski
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - David R Williams
- Center for Visual Science, University of Rochester, Rochester, New York, United States 2Flaum Eye Institute, University of Rochester, Rochester, New York, United States 6The Institute of Optics, University of Rochester, Rochester, New York, United States
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Jones MK, Lu B, Girman S, Wang S. Cell-based therapeutic strategies for replacement and preservation in retinal degenerative diseases. Prog Retin Eye Res 2017; 58:1-27. [PMID: 28111323 PMCID: PMC5441967 DOI: 10.1016/j.preteyeres.2017.01.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 01/08/2017] [Accepted: 01/17/2017] [Indexed: 12/13/2022]
Abstract
Cell-based therapeutics offer diverse options for treating retinal degenerative diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). AMD is characterized by both genetic and environmental risks factors, whereas RP is mainly a monogenic disorder. Though treatments exist for some patients with neovascular AMD, a majority of retinal degenerative patients have no effective therapeutics, thus indicating a need for universal therapies to target diverse patient populations. Two main cell-based mechanistic approaches are being tested in clinical trials. Replacement therapies utilize cell-derived retinal pigment epithelial (RPE) cells to supplant lost or defective host RPE cells. These cells are similar in morphology and function to native RPE cells and can potentially supplant the responsibilities of RPE in vivo. Preservation therapies utilize supportive cells to aid in visual function and photoreceptor preservation partially by neurotrophic mechanisms. The goal of preservation strategies is to halt or slow the progression of disease and maintain remaining visual function. A number of clinical trials are testing the safety of replacement and preservation cell therapies in patients; however, measures of efficacy will need to be further evaluated. In addition, a number of prevailing concerns with regards to the immune-related response, longevity, and functionality of the grafted cells will need to be addressed in future trials. This review will summarize the current status of cell-based preclinical and clinical studies with a focus on replacement and preservation strategies and the obstacles that remain regarding these types of treatments.
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Affiliation(s)
- Melissa K Jones
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Bin Lu
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Sergey Girman
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Shaomei Wang
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave., Los Angeles, CA 90095, USA.
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Bremer D, Pache F, Günther R, Hornow J, Andresen V, Leben R, Mothes R, Zimmermann H, Brandt AU, Paul F, Hauser AE, Radbruch H, Niesner R. Longitudinal Intravital Imaging of the Retina Reveals Long-term Dynamics of Immune Infiltration and Its Effects on the Glial Network in Experimental Autoimmune Uveoretinitis, without Evident Signs of Neuronal Dysfunction in the Ganglion Cell Layer. Front Immunol 2016; 7:642. [PMID: 28066446 PMCID: PMC5179567 DOI: 10.3389/fimmu.2016.00642] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 12/13/2016] [Indexed: 12/12/2022] Open
Abstract
A hallmark of autoimmune retinal inflammation is the infiltration of the retina with cells of the innate and adaptive immune system, leading to detachment of the retinal layers and even to complete loss of the retinal photoreceptor layer. As the only optical system in the organism, the eye enables non-invasive longitudinal imaging studies of these local autoimmune processes and of their effects on the target tissue. Moreover, as a window to the central nervous system (CNS), the eye also reflects general neuroinflammatory processes taking place at various sites within the CNS. Histological studies in murine neuroinflammatory models, such as experimental autoimmune uveoretinitis (EAU) and experimental autoimmune encephalomyelitis, indicate that immune infiltration is initialized by effector CD4+ T cells, with the innate compartment (neutrophils, macrophages, and monocytes) contributing crucially to tissue degeneration that occurs at later phases of the disease. However, how the immune attack is orchestrated by various immune cell subsets in the retina and how the latter interact with the target tissue under in vivo conditions is still poorly understood. Our study addresses this gap with a novel approach for intravital two-photon microscopy, which enabled us to repeatedly track CD4+ T cells and LysM phagocytes during the entire course of EAU and to identify a specific radial infiltration pattern of these cells within the inflamed retina, starting from the optic nerve head. In contrast, highly motile CX3CR1+ cells display an opposite radial motility pattern, toward the optic nerve head. These inflammatory processes induce modifications of the microglial network toward an activated morphology, especially around the optic nerve head and main retinal blood vessels, but do not affect the neurons within the ganglion cell layer. Thanks to the new technology, non-invasive correlation of clinical scores of CNS-related pathologies with immune infiltrate behavior and subsequent tissue dysfunction is now possible. Hence, the new approach paves the way for deeper insights into the pathology of neuroinflammatory processes on a cellular basis, over the entire disease course.
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Affiliation(s)
- Daniel Bremer
- German Rheumatism Research Center , Berlin , Germany
| | - Florence Pache
- German Rheumatism Research Center, Berlin, Germany; NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | | - Ruth Leben
- German Rheumatism Research Center , Berlin , Germany
| | - Ronja Mothes
- German Rheumatism Research Center, Berlin, Germany; Department of Neuropathology, Charité - Universitätsmedizin, Berlin, Germany
| | - Hanna Zimmermann
- NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Alexander U Brandt
- NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Friedemann Paul
- NeuroCure Clinical Research Center, Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité - Universitätsmedizin Berlin , Berlin , Germany
| | - Anja E Hauser
- German Rheumatism Research Center, Berlin, Germany; Immundynamics, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Helena Radbruch
- Department of Neuropathology, Charité - Universitätsmedizin , Berlin , Germany
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Palczewska G, Maeda A, Golczak M, Arai E, Dong Z, Perusek L, Kevany B, Palczewski K. Receptor MER Tyrosine Kinase Proto-oncogene (MERTK) Is Not Required for Transfer of Bis-retinoids to the Retinal Pigmented Epithelium. J Biol Chem 2016; 291:26937-26949. [PMID: 27875314 DOI: 10.1074/jbc.m116.764563] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 11/14/2016] [Indexed: 01/08/2023] Open
Abstract
Accumulation of bis-retinoids in the retinal pigmented epithelium (RPE) is a hallmark of aging and retinal disorders such as Stargardt disease and age-related macular degeneration. These aberrant fluorescent condensation products, including di-retinoid-pyridinium-ethanolamine (A2E), are thought to be transferred to RPE cells primarily through phagocytosis of the photoreceptor outer segments. However, we observed by two-photon microscopy that mouse retinas incapable of phagocytosis due to a deficiency of the c-Mer proto-oncogene tyrosine kinase (Mertk) nonetheless contained fluorescent retinoid condensation material in their RPE. Primary RPE cells from Mertk-/- mice also accumulated fluorescent products in vitro Finally, quantification of A2E demonstrated the acquisition of retinal condensation products in Mertk-/- mouse RPE prior to retinal degeneration. In these mice, we identified activated microglial cells that likely were recruited to transport A2E-like condensation products to the RPE and dispose of the dying photoreceptor cells. These observations demonstrate a novel transport mechanism between photoreceptor cells and RPE that does not involve canonical Mertk-dependent phagocytosis.
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Affiliation(s)
| | - Akiko Maeda
- the Departments of Ophthalmology and Visual Sciences and
| | - Marcin Golczak
- Pharmacology and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| | - Eisuke Arai
- the Departments of Ophthalmology and Visual Sciences and
| | | | | | - Brian Kevany
- Pharmacology and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
| | - Krzysztof Palczewski
- Pharmacology and Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
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Chen Y, Palczewska G, Masuho I, Gao S, Jin H, Dong Z, Gieser L, Brooks MJ, Kiser PD, Kern TS, Martemyanov KA, Swaroop A, Palczewski K. Synergistically acting agonists and antagonists of G protein-coupled receptors prevent photoreceptor cell degeneration. Sci Signal 2016; 9:ra74. [PMID: 27460988 DOI: 10.1126/scisignal.aag0245] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Photoreceptor cell degeneration leads to visual impairment and blindness in several types of retinal disease. However, the discovery of safe and effective therapeutic strategies conferring photoreceptor cell protection remains challenging. Targeting distinct cellular pathways with low doses of different drugs that produce a functionally synergistic effect could provide a strategy for preventing or treating retinal dystrophies. We took a systems pharmacology approach to identify potential combination therapies using a mouse model of light-induced retinal degeneration. We showed that a combination of U.S. Food and Drug Administration-approved drugs that act on different G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors (GPCRs) exhibited synergistic activity that protected retinas from light-induced degeneration even when each drug was administered at a low dose. In functional assays, the combined effects of these drugs were stimulation of Gi/o signaling by activating the dopamine receptors D2R and D4R, as well as inhibition of Gs and Gq signaling by antagonizing D1R and the α1A-adrenergic receptor ADRA1A, respectively. Moreover, transcriptome analyses demonstrated that such combined GPCR-targeted treatments preserved patterns of retinal gene expression that were more similar to those of the normal retina than did higher-dose monotherapy. Our study thus supports a systems pharmacology approach to identify treatments for retinopathies, an approach that could extend to other complex disorders.
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Affiliation(s)
- Yu Chen
- Yueyang Hospital and Clinical Research Institute of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China. Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
| | | | - Ikuo Masuho
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Songqi Gao
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Hui Jin
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | | | - Linn Gieser
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Matthew J Brooks
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Philip D Kiser
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA
| | - Timothy S Kern
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA. Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. Polgenix Inc., Cleveland, OH 44106, USA.
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Abstract
Recent progress in molecular understanding of the retinoid cycle in mammalian retina stems from painstaking biochemical reconstitution studies supported by natural or engineered animal models with known genetic lesions and studies of humans with specific genetic blinding diseases. Structural and membrane biology have been used to detect critical retinal enzymes and proteins and their substrates and ligands, placing them in a cellular context. These studies have been supplemented by analytical chemistry methods that have identified small molecules by their spectral characteristics, often in conjunction with the evaluation of models of animal retinal disease. It is from this background that rational therapeutic interventions to correct genetic defects or environmental insults are identified. Thus, most presently accepted modulators of the retinoid cycle already have demonstrated promising results in animal models of retinal degeneration. These encouraging signs indicate that some human blinding diseases can be alleviated by pharmacological interventions.
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Affiliation(s)
- Philip D Kiser
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106 ; Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio 44106
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
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Sharma R, Schwarz C, Williams DR, Palczewska G, Palczewski K, Hunter JJ. In Vivo Two-Photon Fluorescence Kinetics of Primate Rods and Cones. Invest Ophthalmol Vis Sci 2016; 57:647-57. [PMID: 26903225 PMCID: PMC4771186 DOI: 10.1167/iovs.15-17946] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Purpose The retinoid cycle maintains vision by regenerating bleached visual pigment through metabolic events, the kinetics of which have been difficult to characterize in vivo. Two-photon fluorescence excitation has been used previously to track autofluorescence directly from retinoids and pyridines in the visual cycle in mouse and frog retinas, but the mechanisms of the retinoid cycle are not well understood in primates. Methods We developed a two-photon fluorescence adaptive optics scanning light ophthalmoscope dedicated to in vivo imaging in anesthetized macaques. Using pulsed light at 730 nm, two-photon fluorescence was captured from rods and cones during light and dark adaptation through the eye's pupil. Results The fluorescence from rods and cones increased with light exposure but at different rates. During dark adaptation, autofluorescence declined, with cone autofluorescence decreasing approximately 4 times faster than from rods. Rates of autofluorescence decrease in rods and cones were approximately 4 times faster than their respective rates of photopigment regeneration. Also, subsets of sparsely distributed cones were less fluorescent than their neighbors immediately following bleach at 565 nm and they were comparable with the S cone mosaic in density and distribution. Conclusions Although other molecules could be contributing, we posit that these fluorescence changes are mediated by products of the retinoid cycle. In vivo two-photon ophthalmoscopy provides a way to monitor noninvasively stages of the retinoid cycle that were previously inaccessible in the living primate eye. This can be used to assess objectively photoreceptor function in normal and diseased retinas.
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Affiliation(s)
- Robin Sharma
- The Institute of Optics, University of Rochester, Rochester, New York, United States 2Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - Christina Schwarz
- Center for Visual Science, University of Rochester, Rochester, New York, United States
| | - David R Williams
- The Institute of Optics, University of Rochester, Rochester, New York, United States 2Center for Visual Science, University of Rochester, Rochester, New York, United States 3Flaum Eye Institute, University of Rochester, Rochester, New York, United States
| | | | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Jennifer J Hunter
- Center for Visual Science, University of Rochester, Rochester, New York, United States 3Flaum Eye Institute, University of Rochester, Rochester, New York, United States
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Xi H, Katschke KJ, Li Y, Truong T, Lee WP, Diehl L, Rangell L, Tao J, Arceo R, Eastham-Anderson J, Hackney JA, Iglesias A, Cote-Sierra J, Elstrott J, Weimer RM, van Lookeren Campagne M. IL-33 amplifies an innate immune response in the degenerating retina. J Exp Med 2016; 213:189-207. [PMID: 26755704 PMCID: PMC4749925 DOI: 10.1084/jem.20150894] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 12/07/2015] [Indexed: 01/12/2023] Open
Abstract
Xi et al. demonstrate that IL-33 is a key regulator of retinal inflammation and degeneration. Age-related macular degeneration (AMD), a leading cause of vision impairment in the ageing population, is characterized by irreversible loss of retinal pigment epithelial (RPE) cells and photoreceptors and can be associated with choroidal neovascularization. Mononuclear phagocytes are often present in AMD lesions, but the processes that direct myeloid cell recruitment remain unclear. Here, we identify IL-33 as a key regulator of inflammation and photoreceptor degeneration after retina stress or injury. IL-33+ Müller cells were more abundant and IL-33 cytokine was elevated in advanced AMD cases compared with age-matched controls with no AMD. In rodents, retina stress resulted in release of bioactive IL-33 that in turn increased inflammatory chemokine and cytokine expression in activated Müller cells. Deletion of ST2, the IL-33 receptor α chain, or treatment with a soluble IL-33 decoy receptor significantly reduced release of inflammatory mediators from Müller cells, inhibited accumulation of mononuclear phagocytes in the outer retina, and protected photoreceptor rods and cones after a retina insult. This study demonstrates a central role for IL-33 in regulating mononuclear phagocyte recruitment to the photoreceptor layer and positions IL-33 signaling as a potential therapeutic target in macular degenerative diseases.
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Affiliation(s)
- Hongkang Xi
- Department of Immunology, Genentech, Inc., South San Francisco, CA 94080
| | - Kenneth J Katschke
- Department of Immunology, Genentech, Inc., South San Francisco, CA 94080
| | - Yun Li
- Department of Immunology, Genentech, Inc., South San Francisco, CA 94080
| | - Tom Truong
- Department of Immunology, Genentech, Inc., South San Francisco, CA 94080
| | - Wyne P Lee
- Department of Immunology, Genentech, Inc., South San Francisco, CA 94080
| | - Lauri Diehl
- Department of Pathology, Genentech, Inc., South San Francisco, CA 94080
| | - Linda Rangell
- Department of Pathology, Genentech, Inc., South San Francisco, CA 94080
| | - Jianhua Tao
- Department of Pathology, Genentech, Inc., South San Francisco, CA 94080
| | - Rommel Arceo
- Department of Pathology, Genentech, Inc., South San Francisco, CA 94080
| | | | - Jason A Hackney
- Department of Bioinformatics and Computational Biology, Genentech, Inc., South San Francisco, CA 94080
| | - Antonio Iglesias
- Roche Pharmaceutical Research and Early Development, Pharmacological Sciences, Roche Innovation Center Basel, CH-4070 Basel, Switzerland
| | - Javier Cote-Sierra
- Roche Pharmaceutical Research and Early Development, Pharmacological Sciences, Roche Innovation Center Basel, CH-4070 Basel, Switzerland
| | - Justin Elstrott
- Department of Biomedical Imaging, Genentech, Inc., South San Francisco, CA 94080
| | - Robby M Weimer
- Department of Biomedical Imaging, Genentech, Inc., South San Francisco, CA 94080
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Kohno H, Koso H, Okano K, Sundermeier TR, Saito S, Watanabe S, Tsuneoka H, Sakai T. Expression pattern of Ccr2 and Cx3cr1 in inherited retinal degeneration. J Neuroinflammation 2015; 12:188. [PMID: 26458944 PMCID: PMC4603985 DOI: 10.1186/s12974-015-0408-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 10/02/2015] [Indexed: 12/27/2022] Open
Abstract
Background Though accumulating evidence suggests that microglia, resident macrophages in the retina, and bone marrow-derived macrophages can cause retinal inflammation which accelerates photoreceptor cell death, the details of how these cells are activated during retinal degeneration (RD) remain uncertain. Therefore, it is important to clarify which cells play a dominant role in fueling retinal inflammation. However, distinguishing between microglia and macrophages is difficult using conventional techniques such as cell markers (e.g., Iba-1). Recently, two mouse models for visualizing chemokine receptors were established, Cx3cr1GFP/GFP and Ccr2RFP/RFP mice. As Cx3cr1 is expressed in microglia and Ccr2 is reportedly expressed in activated macrophages, these mice have the potential to distinguish microglia and macrophages, yielding novel information about the activation of these inflammatory cells and their individual roles in retinal inflammation. Methods In this study, c-mer proto-oncogene tyrosine kinase (Mertk)−/− mice, which show photoreceptor cell death due to defective retinal pigment epithelium phagocytosis, were employed as an animal model of RD. Mertk−/−Cx3cr1GFP/+Ccr2RFP/+ mice were established by breeding Mertk−/−, Cx3cr1GFP/GFP, and Ccr2RFP/RFP mice. The retinal morphology and pattern of inflammatory cell activation and invasion of Mertk−/−Cx3cr1GFP/+Ccr2RFP/+ mice were evaluated using retina and retinal pigment epithelium (RPE) flat mounts, retinal sections, and flow cytometry. Results Four-week-old Mertk−/−Cx3cr1GFP/+Ccr2RFP/+ mice showed Cx3cr1-GFP-positive microglia in the inner retina. Cx3cr1-GFP and Ccr2-RFP dual positive activated microglia were observed in the outer retina and subretinal space of 6- and 8-week-old animals. Ccr2-RFP single positive bone marrow-derived macrophages were observed to migrate into the retina of Mertk−/−Cx3cr1GFP/+Ccr2RFP/+ mice. These invading cells were still observed in the subretinal space in 18-week-old animals. Conclusions Cx3cr1-GFP-positive microglia and Ccr2-RFP-positive macrophages were distinguishable in the retinas of Mertk−/−Cx3cr1GFP/+Ccr2RFP/+ mice. In addition, Ccr2 expression in Cx3cr1 positive microglia is a feature of microglial activation in RD. Mertk−/−Cx3cr1GFP/+Ccr2RFP/+ mice enabled observation of microglial activation over time during RD and may be useful for developing inflammation-targeted treatment strategies for RD in the future.
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Affiliation(s)
- Hideo Kohno
- Department of Ophthalmology, The Jikei University School of Medicine, 105-8461, Tokyo, Japan. .,Tokyu Hospital, 145-0062, Tokyo, Japan.
| | - Hideto Koso
- Division of Molecular and Developmental Biology, The Institute of Medical Science, The University of Tokyo, 108-8639, Tokyo, Japan
| | - Kiichiro Okano
- Department of Ophthalmology, The Jikei University School of Medicine, 105-8461, Tokyo, Japan
| | - Thomas R Sundermeier
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Saburo Saito
- Department of Molecular Immunology, The Jikei University School of Medicine, 105-8461, Tokyo, Japan
| | - Sumiko Watanabe
- Division of Molecular and Developmental Biology, The Institute of Medical Science, The University of Tokyo, 108-8639, Tokyo, Japan
| | - Hiroshi Tsuneoka
- Department of Ophthalmology, The Jikei University School of Medicine, 105-8461, Tokyo, Japan
| | - Tsutomu Sakai
- Department of Ophthalmology, The Jikei University School of Medicine, 105-8461, Tokyo, Japan.
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Stremplewski P, Komar K, Palczewski K, Wojtkowski M, Palczewska G. Periscope for noninvasive two-photon imaging of murine retina in vivo. BIOMEDICAL OPTICS EXPRESS 2015; 6:3352-61. [PMID: 26417507 PMCID: PMC4574663 DOI: 10.1364/boe.6.003352] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 08/01/2015] [Accepted: 08/02/2015] [Indexed: 05/18/2023]
Abstract
Two-photon microscopy allows visualization of subcellular structures in the living animal retina. In previously reported experiments it was necessary to apply a contact lens to each subject. Extending this technology to larger animals would require fitting a custom contact lens to each animal and cumbersome placement of the living animal head on microscope stage. Here we demonstrate a new device, periscope, for coupling light energy into mouse eye and capturing emitted fluorescence. Using this periscope we obtained images of the RPE and their subcellular organelles, retinosomes, with larger field of view than previously reported. This periscope provides an interface with a commercial microscope, does not require contact lens and its design could be modified to image retina in larger animals.
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Affiliation(s)
- Patrycjusz Stremplewski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Katarzyna Komar
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Maciej Wojtkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, 87-100 Torun, Poland
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Alexander NS, Palczewska G, Palczewski K. Semi-automated discrimination of retinal pigmented epithelial cells in two-photon fluorescence images of mouse retinas. BIOMEDICAL OPTICS EXPRESS 2015; 6:3032-3052. [PMID: 26309765 PMCID: PMC4541529 DOI: 10.1364/boe.6.003032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/20/2015] [Accepted: 07/21/2015] [Indexed: 06/04/2023]
Abstract
Automated image segmentation is a critical step toward achieving a quantitative evaluation of disease states with imaging techniques. Two-photon fluorescence microscopy (TPM) has been employed to visualize the retinal pigmented epithelium (RPE) and provide images indicating the health of the retina. However, segmentation of RPE cells within TPM images is difficult due to small differences in fluorescence intensity between cell borders and cell bodies. Here we present a semi-automated method for segmenting RPE cells that relies upon multiple weak features that differentiate cell borders from the remaining image. These features were scored by a search optimization procedure that built up the cell border in segments around a nucleus of interest. With six images used as a test, our method correctly identified cell borders for 69% of nuclei on average. Performance was strongly dependent upon increasing retinosome content in the RPE. TPM image analysis has the potential of providing improved early quantitative assessments of diseases affecting the RPE.
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Affiliation(s)
- Nathan S. Alexander
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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37
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Orban T, Johnson WM, Dong Z, Maeda T, Maeda A, Sakai T, Tsuneoka H, Mieyal JJ, Palczewski K. Serum levels of lipid metabolites in age-related macular degeneration. FASEB J 2015; 29:4579-88. [PMID: 26187344 DOI: 10.1096/fj.15-275289] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/06/2015] [Indexed: 01/24/2023]
Abstract
Age-related macular degeneration (AMD) is a neurodegenerative disease that causes adult-onset blindness. There are 2 forms of this progressive disease: wet and dry. Currently there is no cure for AMD, but several treatment options have started to emerge making early detection critical for therapeutic success. Analysis of the eyes of Abca4(-/-)Rdh8(-/-) mice that display light-induced retinal degeneration indicates that 11-cis-retinal and docosahexaenoic acid (DHA) levels were significantly decreased as compared with the eyes of control dark-adapted C57BL/6J mice. In addition, exposure to intense light correlated with higher levels of prostaglandin G2 in the eyes of Abca4(-/-)Rdh8(-/-) mice. Intense light exposure also lowered DHA levels in the eyes of wild-type C57BL/6J mice without discernible retinal degeneration. Analysis of human serum from patients with AMD recapitulated these dysregulated DHA levels and revealed dysregulation of arachidonic acid (AA) levels as well (∼32% increase in patients with AMD compared with average levels in healthy individuals). From these observations, we then built a statistical model that included levels of DHA and AA from human serum. This model had a 74% probability of correctly identifying patients with AMD from controls. Addition of a genetic analysis for one of the most prevalent amino acid substitutions in the age-related maculopathy susceptibility 2 gene linked to AMD, Ala(69)→Ser, did not improve the statistical model. Thus, we have characterized a reliable method with the potential to detect AMD without a genetic component, paving the way for a larger-scale clinical evaluation. Our studies on mouse models along with the analysis of human serum suggest that our small molecule-based model may serve as an effective tool to estimate the risk of developing AMD.
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Affiliation(s)
- Tivadar Orban
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - William M Johnson
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - Zhiqian Dong
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - Tadao Maeda
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - Akiko Maeda
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - Tsutomu Sakai
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - Hiroshi Tsuneoka
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - John J Mieyal
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
| | - Krzysztof Palczewski
- *Department of Pharmacology and Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA; Polgenix, Incorporated, Cleveland, Ohio, USA; Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; and Louis Stokes Veterans Affairs Medical Research Center, Cleveland, Ohio, USA
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Zhang J, Kiser PD, Badiee M, Palczewska G, Dong Z, Golczak M, Tochtrop GP, Palczewski K. Molecular pharmacodynamics of emixustat in protection against retinal degeneration. J Clin Invest 2015; 125:2781-94. [PMID: 26075817 DOI: 10.1172/jci80950] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 05/12/2015] [Indexed: 01/24/2023] Open
Abstract
Emixustat is a visual cycle modulator that has entered clinical trials as a treatment for age-related macular degeneration (AMD). This molecule has been proposed to inhibit the visual cycle isomerase RPE65, thereby slowing regeneration of 11-cis-retinal and reducing production of retinaldehyde condensation byproducts that may be involved in AMD pathology. Previously, we reported that all-trans-retinal (atRAL) is directly cytotoxic and that certain primary amine compounds that transiently sequester atRAL via Schiff base formation ameliorate retinal degeneration. Here, we have shown that emixustat stereoselectively inhibits RPE65 by direct active site binding. However, we detected the presence of emixustat-atRAL Schiff base conjugates, indicating that emixustat also acts as a retinal scavenger, which may contribute to its therapeutic effects. Using agents that lack either RPE65 inhibitory activity or the capacity to sequester atRAL, we assessed the relative importance of these 2 modes of action in protection against retinal phototoxicity in mice. The atRAL sequestrant QEA-B-001-NH2 conferred protection against phototoxicity without inhibiting RPE65, whereas an emixustat derivative incapable of atRAL sequestration was minimally protective, despite direct inhibition of RPE65. These data indicate that atRAL sequestration is an essential mechanism underlying the protective effects of emixustat and related compounds against retinal phototoxicity. Moreover, atRAL sequestration should be considered in the design of next-generation visual cycle modulators.
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Bosco A, Romero CO, Ambati BK, Vetter ML. In vivo dynamics of retinal microglial activation during neurodegeneration: confocal ophthalmoscopic imaging and cell morphometry in mouse glaucoma. J Vis Exp 2015:e52731. [PMID: 25992962 DOI: 10.3791/52731] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Microglia, which are CNS-resident neuroimmune cells, transform their morphology and size in response to CNS damage, switching to an activated state with distinct functions and gene expression profiles. The roles of microglial activation in health, injury and disease remain incompletely understood due to their dynamic and complex regulation in response to changes in their microenvironment. Thus, it is critical to non-invasively monitor and analyze changes in microglial activation over time in the intact organism. In vivo studies of microglial activation have been delayed by technical limitations to tracking microglial behavior without altering the CNS environment. This has been particularly challenging during chronic neurodegeneration, where long-term changes must be tracked. The retina, a CNS organ amenable to non-invasive live imaging, offers a powerful system to visualize and characterize the dynamics of microglia activation during chronic disorders. This protocol outlines methods for long-term, in vivo imaging of retinal microglia, using confocal ophthalmoscopy (cSLO) and CX3CR1(GFP/+) reporter mice, to visualize microglia with cellular resolution. Also, we describe methods to quantify monthly changes in cell activation and density in large cell subsets (200-300 cells per retina). We confirm the use of somal area as a useful metric for live tracking of microglial activation in the retina by applying automated threshold-based morphometric analysis of in vivo images. We use these live image acquisition and analyses strategies to monitor the dynamic changes in microglial activation and microgliosis during early stages of retinal neurodegeneration in a mouse model of chronic glaucoma. This approach should be useful to investigate the contributions of microglia to neuronal and axonal decline in chronic CNS disorders that affect the retina and optic nerve.
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Affiliation(s)
| | - Cesar O Romero
- Department of Neurobiology & Anatomy, University of Utah
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40
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Chen Y, Palczewski K. Systems Pharmacology Links GPCRs with Retinal Degenerative Disorders. Annu Rev Pharmacol Toxicol 2015; 56:273-98. [PMID: 25839098 DOI: 10.1146/annurev-pharmtox-010715-103033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In most biological systems, second messengers and their key regulatory and effector proteins form links between multiple cellular signaling pathways. Such signaling nodes can integrate the deleterious effects of genetic aberrations, environmental stressors, or both in complex diseases, leading to cell death by various mechanisms. Here we present a systems (network) pharmacology approach that, together with transcriptomics analyses, was used to identify different G protein-coupled receptors that experimentally protected against cellular stress and death caused by linked signaling mechanisms. We describe the application of this concept to degenerative and diabetic retinopathies in appropriate mouse models as an example. Systems pharmacology also provides an attractive framework for devising strategies to combat complex diseases by using (repurposing) US Food and Drug Administration-approved pharmacological agents.
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Affiliation(s)
- Yu Chen
- Yueyang Hospital and.,Clinical Research Institute of Integrative Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106;
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41
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Bosco A, Romero CO, Breen KT, Chagovetz AA, Steele MR, Ambati BK, Vetter ML. Neurodegeneration severity can be predicted from early microglia alterations monitored in vivo in a mouse model of chronic glaucoma. Dis Model Mech 2015; 8:443-55. [PMID: 25755083 PMCID: PMC4415894 DOI: 10.1242/dmm.018788] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 02/26/2015] [Indexed: 12/30/2022] Open
Abstract
Microglia serve key homeostatic roles, and respond to neuronal perturbation and decline with a high spatiotemporal resolution. The course of all chronic CNS pathologies is thus paralleled by local microgliosis and microglia activation, which begin at early stages of the disease. However, the possibility of using live monitoring of microglia during early disease progression to predict the severity of neurodegeneration has not been explored. Because the retina allows live tracking of fluorescent microglia in their intact niche, here we investigated their early changes in relation to later optic nerve neurodegeneration. To achieve this, we used the DBA/2J mouse model of inherited glaucoma, which develops progressive retinal ganglion cell degeneration of variable severity during aging, and represents a useful model to study pathogenic mechanisms of retinal ganglion cell decline that are similar to those in human glaucoma. We imaged CX3CR1(+/GFP) microglial cells in vivo at ages ranging from 1 to 5 months by confocal scanning laser ophthalmoscopy (cSLO) and quantified cell density and morphological activation. We detected early microgliosis at the optic nerve head (ONH), where axonopathy first manifests, and could track attenuation of this microgliosis induced by minocycline. We also observed heterogeneous and dynamic patterns of early microglia activation in the retina. When the same animals were aged and analyzed for the severity of optic nerve pathology at 10 months of age, we found a strong correlation with the levels of ONH microgliosis at 3 to 4 months. Our findings indicate that live imaging and monitoring the time course and levels of early retinal microgliosis and microglia activation in glaucoma could serve as indicators of future neurodegeneration severity.
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Affiliation(s)
- Alejandra Bosco
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
| | - Cesar O Romero
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
| | - Kevin T Breen
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
| | - Alexis A Chagovetz
- Department of Human Genetics, University of Utah, Salt Lake City, UT 84132, USA
| | - Michael R Steele
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
| | - Balamurali K Ambati
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT 84132, USA
| | - Monica L Vetter
- Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, UT 84132, USA
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Zhang N, Tsybovsky Y, Kolesnikov AV, Rozanowska M, Swider M, Schwartz SB, Stone EM, Palczewska G, Maeda A, Kefalov VJ, Jacobson SG, Cideciyan AV, Palczewski K. Protein misfolding and the pathogenesis of ABCA4-associated retinal degenerations. Hum Mol Genet 2015; 24:3220-37. [PMID: 25712131 DOI: 10.1093/hmg/ddv073] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/22/2015] [Indexed: 12/13/2022] Open
Abstract
Mutations in the ABCA4 gene are a common cause of autosomal recessive retinal degeneration. All mouse models to date are based on knockouts of Abca4, even though the disease is often caused by missense mutations such as the complex allele L541P;A1038V (PV). We now show that the PV mutation causes severe human disease whereas the V mutation alone causes mild disease. Mutant ABCA4 proteins expressed heterologously in mammalian cells retained normal cellular localization. However, basal and all-trans-retinal-stimulated ATPase activities were reduced substantially for P and PV but only mildly for V. Electron microscopy revealed marked structural changes and misfolding for the P and PV mutants but few changes for the V mutant, consistent with the disease severity difference in patients. We generated Abca4(PV/PV) knock-in mice homozygous for the complex PV allele to investigate the effects of this misfolding mutation in vivo. Mutant ABCA4 RNA levels approximated WT ABCA4 RNA levels but, surprisingly, only trace amounts of mutant ABCA4 protein were noted in the retina. RNA sequencing of WT, Abca4(-/-) and Abca4(PV/PV) mice revealed mild gene expression alterations in the retina and RPE. Similar to Abca4(-/-) mice, Abca4(PV/PV) mice showed substantial A2E and lipofuscin accumulation in their RPE cells but no retinal degeneration up to 12 months of age. Thus, rapid degradation of this large misfolded mutant protein in mouse retina caused little detectable photoreceptor degeneration. These findings suggest likely differences in the unfolded protein response between murine and human photoreceptors and support development of therapies directed at increasing this capability in patients.
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Affiliation(s)
- Ning Zhang
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology and
| | - Yaroslav Tsybovsky
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology and
| | - Alexander V Kolesnikov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8096, Saint Louis, MO 63110, USA
| | - Malgorzata Rozanowska
- Department of Ophthalmology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Malgorzata Swider
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sharon B Schwartz
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Edwin M Stone
- Department of Ophthalmology, University of Iowa Carver College of Medicine, Iowa City, IA, USA Howard Hughes Medical Institute, Iowa City, IA, USA and
| | | | - Akiko Maeda
- Department of Ophthalmology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8096, Saint Louis, MO 63110, USA
| | - Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Artur V Cideciyan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Krzysztof Palczewski
- Department of Pharmacology and Cleveland Center for Membrane and Structural Biology and
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43
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Marquioni-Ramella MD, Suburo AM. Photo-damage, photo-protection and age-related macular degeneration. Photochem Photobiol Sci 2015. [DOI: 10.1039/c5pp00188a] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The course of Age-related Macular Degeneration (AMD) is described as the effect of light (400–580 nm) on various molecular targets in photoreceptors and the retinal pigment epithelium (RPE). Photo-damage is followed by inflammation, increasing oxidative stress and, probably, unveiling new photosensitive molecules.
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Affiliation(s)
| | - Angela M. Suburo
- Medicina Celular y Molecular
- Facultad de Ciencias Biomédicas
- Universidad Austral
- Pilar B1629AHJ
- Argentina
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Zhang J, Dong Z, Mundla SR, Hu XE, Seibel W, Papoian R, Palczewski K, Golczak M. Expansion of first-in-class drug candidates that sequester toxic all-trans-retinal and prevent light-induced retinal degeneration. Mol Pharmacol 2014; 87:477-91. [PMID: 25538117 DOI: 10.1124/mol.114.096560] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
All-trans-retinal, a retinoid metabolite naturally produced upon photoreceptor light activation, is cytotoxic when present at elevated levels in the retina. To lower its toxicity, two experimentally validated methods have been developed involving inhibition of the retinoid cycle and sequestration of excess of all-trans-retinal by drugs containing a primary amine group. We identified the first-in-class drug candidates that transiently sequester this metabolite or slow down its production by inhibiting regeneration of the visual chromophore, 11-cis-retinal. Two enzymes are critical for retinoid recycling in the eye. Lecithin:retinol acyltransferase (LRAT) is the enzyme that traps vitamin A (all-trans-retinol) from the circulation and photoreceptor cells to produce the esterified substrate for retinoid isomerase (RPE65), which converts all-trans-retinyl ester into 11-cis-retinol. Here we investigated retinylamine and its derivatives to assess their inhibitor/substrate specificities for RPE65 and LRAT, mechanisms of action, potency, retention in the eye, and protection against acute light-induced retinal degeneration in mice. We correlated levels of visual cycle inhibition with retinal protective effects and outlined chemical boundaries for LRAT substrates and RPE65 inhibitors to obtain critical insights into therapeutic properties needed for retinal preservation.
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Affiliation(s)
- Jianye Zhang
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - Zhiqian Dong
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - Sreenivasa Reddy Mundla
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - X Eric Hu
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - William Seibel
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - Ruben Papoian
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - Krzysztof Palczewski
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio (J.Z., Z.D., K.P., M.G.); Sreeni Laboratories Private Limited, Telangana, India (S.R.M.); Aroz Technologies LLC, Cincinnati, Ohio (X.E.H.); and Drug Discovery Center, College of Medicine, University of Cincinnati, Cincinnati, Ohio (W.S., R.P.)
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Palczewski K. Chemistry and biology of the initial steps in vision: the Friedenwald lecture. Invest Ophthalmol Vis Sci 2014; 55:6651-72. [PMID: 25338686 DOI: 10.1167/iovs.14-15502] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Visual transduction is the process in the eye whereby absorption of light in the retina is translated into electrical signals that ultimately reach the brain. The first challenge presented by visual transduction is to understand its molecular basis. We know that maintenance of vision is a continuous process requiring the activation and subsequent restoration of a vitamin A-derived chromophore through a series of chemical reactions catalyzed by enzymes in the retina and retinal pigment epithelium (RPE). Diverse biochemical approaches that identified key proteins and reactions were essential to achieve a mechanistic understanding of these visual processes. The three-dimensional arrangements of these enzymes' polypeptide chains provide invaluable insights into their mechanisms of action. A wealth of information has already been obtained by solving high-resolution crystal structures of both rhodopsin and the retinoid isomerase from pigment RPE (RPE65). Rhodopsin, which is activated by photoisomerization of its 11-cis-retinylidene chromophore, is a prototypical member of a large family of membrane-bound proteins called G protein-coupled receptors (GPCRs). RPE65 is a retinoid isomerase critical for regeneration of the chromophore. Electron microscopy (EM) and atomic force microscopy have provided insights into how certain proteins are assembled to form much larger structures such as rod photoreceptor cell outer segment membranes. A second challenge of visual transduction is to use this knowledge to devise therapeutic approaches that can prevent or reverse conditions leading to blindness. Imaging modalities like optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) applied to appropriate animal models as well as human retinal imaging have been employed to characterize blinding diseases, monitor their progression, and evaluate the success of therapeutic agents. Lately two-photon (2-PO) imaging, together with biochemical assays, are revealing functional aspects of vision at a new molecular level. These multidisciplinary approaches combined with suitable animal models and inbred mutant species can be especially helpful in translating provocative cell and tissue culture findings into therapeutic options for further development in animals and eventually in humans. A host of different approaches and techniques is required for substantial progress in understanding fundamental properties of the visual system.
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Affiliation(s)
- Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
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Horie-Inoue K, Inoue S. Genomic aspects of age-related macular degeneration. Biochem Biophys Res Commun 2014; 452:263-75. [PMID: 25111812 DOI: 10.1016/j.bbrc.2014.08.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 08/04/2014] [Indexed: 11/29/2022]
Abstract
Age-related macular degeneration (AMD) is a major late-onset posterior eye disease that causes central vision to deteriorate among elderly populations. The predominant lesion of AMD is the macula, at the interface between the outer retina and the inner choroid. Recent advances in genetics have revealed that inflammatory and angiogenic pathways play critical roles in the pathophysiology of AMD. Genome-wide association studies have identified ARMS2/HTRA1 and CFH as major AMD susceptibility genes. Genetic studies for AMD will contribute to the prevention of central vision loss, the development of new treatment, and the maintenance of quality of vision for productive aging.
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Affiliation(s)
- Kuniko Horie-Inoue
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan.
| | - Satoshi Inoue
- Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan; Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Palczewska G, Golczak M, Williams DR, Hunter JJ, Palczewski K. Endogenous fluorophores enable two-photon imaging of the primate eye. Invest Ophthalmol Vis Sci 2014; 55:4438-47. [PMID: 24970255 DOI: 10.1167/iovs.14-14395] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Noninvasive two-photon imaging of a living mammalian eye can reveal details of molecular processes in the retina and RPE. Retinyl esters and all-trans-retinal condensation products are two types of retinoid fluorophores present in these tissues. We measured the content of these two types of retinoids in monkey and human eyes to validate the potential of two-photon imaging for monitoring retinoid changes in human eyes. METHODS Two-photon microscopy (TPM) was used to visualize excised retina from monkey eyes. Retinoid composition and content in human and monkey eyes were quantified by HPLC and mass spectrometry (MS). RESULTS Clear images of inner and outer segments of rods and cones were obtained in primate eyes at different eccentricities. Fluorescence spectra from outer segments revealed a maximum emission at 480 nm indicative of retinols and their esters. In cynomolgus monkey and human retinal extracts, retinyl esters existed predominantly in the 11-cis configuration along with notable levels of 11-cis-retinol, a characteristic of cone-enriched retinas. Average amounts of di-retinoid-pyridinium-ethanolamine (A2E) in primate and human eyes were 160 and 225 pmol/eye, respectively. CONCLUSIONS These data show that human retina contains sufficient amounts of retinoids for two-photon excitation imaging. Greater amounts of 11-cis-retinyl esters relative to rodent retinas contribute to the fluorescence signal from both monkey and human eyes. These observations indicate that TPM imaging found effective in mice could detect early age- and disease-related changes in human retina.
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Affiliation(s)
| | - Marcin Golczak
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - David R Williams
- Center for Visual Science, University of Rochester, Rochester, New York, United States The Institute of Optics, University of Rochester, Rochester, New York, United States
| | - Jennifer J Hunter
- Center for Visual Science, University of Rochester, Rochester, New York, United States Flaum Eye Institute, University of Rochester, Rochester, New York, United States Department of Biomedical Engineering, University of Rochester, Rochester, New York, United States
| | - Krzysztof Palczewski
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
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