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Stone RA, Tobias JW, Wei W, Schug J, Wang X, Zhang L, Iuvone PM, Nickla DL. Diurnal retinal and choroidal gene expression patterns support a role for circadian biology in myopia pathogenesis. Sci Rep 2024; 14:533. [PMID: 38177383 PMCID: PMC10767138 DOI: 10.1038/s41598-023-50684-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 12/22/2023] [Indexed: 01/06/2024] Open
Abstract
The prevalence of myopia (nearsightedness) is increasing to alarming levels, but its etiology remains poorly understood. Because both laboratory and clinical findings suggest an etiologic role for circadian rhythms in myopia development, we assayed gene expression by RNA-Seq in retina and choroid at the onset of unilateral experimental myopia in chick, isolating tissues every 4 h during a single 24-h period from myopic and contralateral control eyes. Occluded versus open eye gene expression differences varied considerably over the 24-h sampling period, with some occurring at multiple times of day but with others showing differences at only a single investigated timepoint. Some of the genes identified in retina or choroid of chick myopia were previously identified as candidate genes for common human myopia. Like differentially expressed genes, pathways identified by Gene Set Enrichment Analysis also varied dramatically by sampling time. Considered with other laboratory data, human genetic and epidemiology data, these findings further implicate circadian events in myopia pathogenesis. The present results emphasize a need to include time of day in mechanistic studies of myopia and to assess circadian biology directly in trying to understand better the origin of myopia and to develop more effective therapies.
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Affiliation(s)
- Richard A Stone
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - John W Tobias
- Penn Genomics and Sequencing Core, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wenjie Wei
- Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jonathan Schug
- Penn Genomics and Sequencing Core, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Xia Wang
- Department of Biomedical Sciences and Disease, New England College of Optometry, Boston, MA, USA
| | - Lixin Zhang
- Department of Biomedical Sciences and Disease, New England College of Optometry, Boston, MA, USA
| | - P Michael Iuvone
- Department of Ophthalmology and Department of Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Debora L Nickla
- Department of Biomedical Sciences and Disease, New England College of Optometry, Boston, MA, USA
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Allen RS, Khayat CT, Feola AJ, Win AS, Grubman AR, Chesler KC, He L, Dixon JA, Kern TS, Iuvone PM, Thule PM, Pardue MT. Diabetic rats with high levels of endogenous dopamine do not show retinal vascular pathology. Front Neurosci 2023; 17:1125784. [PMID: 37034167 PMCID: PMC10073440 DOI: 10.3389/fnins.2023.1125784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/21/2023] [Indexed: 04/11/2023] Open
Abstract
Purpose Limited research exists on the time course of long-term retinal and cerebral deficits in diabetic rodents. Previously, we examined short term (4-8 weeks) deficits in the Goto-Kakizaki (GK) rat model of Type II diabetes. Here, we investigated the long-term (1-8 months) temporal appearance of functional deficits (retinal, cognitive, and motor), retinal vascular pathology, and retinal dopamine levels in the GK rat. Methods In GK rats and Wistar controls, retinal neuronal function (electroretinogram), cognitive function (Y-maze), and motor function (rotarod) were measured at 1, 2, 4, 6, and 8 months of age. In addition, we evaluated retinal vascular function (functional hyperemia) and glucose and insulin tolerance. Retinas from rats euthanized at ≥8 months were assessed for vascular pathology. Dopamine and DOPAC levels were measured via HPLC in retinas from rats euthanized at 1, 2, 8, and 12 months. Results Goto-Kakizaki rats exhibited significant glucose intolerance beginning at 4 weeks and worsening over time (p < 0.001). GK rats also showed significant delays in flicker and oscillatory potential implicit times (p < 0.05 to p < 0.001) beginning at 1 month. Cognitive deficits were observed beginning at 6 months (p < 0.05), but no motor deficits. GK rats showed no deficits in functional hyperemia and no increase in acellular retinal capillaries. Dopamine levels were twice as high in GK vs. Wistar retinas at 1, 2, 8, and 12 months (p < 0.001). Conclusion As shown previously, retinal deficits were detectable prior to cognitive deficits in GK rats. While retinal neuronal function was compromised, retinal vascular pathology was not observed, even at 12+ months. High endogenous levels of dopamine in the GK rat may be acting as an anti-angiogenic and providing protection against vascular pathology.
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Affiliation(s)
- Rachael S. Allen
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Cara T. Khayat
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
| | - Andrew J. Feola
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Alice S. Win
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Allison R. Grubman
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Kyle C. Chesler
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
| | - Li He
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, United States
| | - Jendayi A. Dixon
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Timothy S. Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States
- Veterans Administration Medical Center Research Service, Cleveland, OH, United States
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA, United States
| | - Peter M. Thule
- Section Endocrinology and Metabolism, Atlanta VA Medical Center, Emory University School of Medicine, Decatur, GA, United States
| | - Machelle T. Pardue
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, United States
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
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3
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Ferdous S, Shelton DA, Getz TE, Chrenek MA, L’Hernault N, Sellers JT, Summers VR, Iuvone PM, Boss JM, Boatright JH, Nickerson JM. Deletion of histone demethylase Lsd1 (Kdm1a) during retinal development leads to defects in retinal function and structure. Front Cell Neurosci 2023; 17:1104592. [PMID: 36846208 PMCID: PMC9950115 DOI: 10.3389/fncel.2023.1104592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/18/2023] [Indexed: 02/12/2023] Open
Abstract
Purpose The purpose of this study was to investigate the role of Lysine specific demethylase 1 (Lsd1) in murine retinal development. LSD1 is a histone demethylase that can demethylate mono- and di-methyl groups on H3K4 and H3K9. Using Chx10-Cre and Rho-iCre75 driver lines, we generated novel transgenic mouse lines to delete Lsd1 in most retinal progenitor cells or specifically in rod photoreceptors. We hypothesize that Lsd1 deletion will cause global morphological and functional defects due to its importance in neuronal development. Methods We tested the retinal function of young adult mice by electroretinogram (ERG) and assessed retinal morphology by in vivo imaging by fundus photography and SD-OCT. Afterward, eyes were enucleated, fixed, and sectioned for subsequent hematoxylin and eosin (H&E) or immunofluorescence staining. Other eyes were plastic fixed and sectioned for electron microscopy. Results In adult Chx10-Cre Lsd1fl/fl mice, we observed a marked reduction in a-, b-, and c-wave amplitudes in scotopic conditions compared to age-matched control mice. Photopic and flicker ERG waveforms were even more sharply reduced. Modest reductions in total retinal thickness and outer nuclear layer (ONL) thickness were observed in SD-OCT and H&E images. Lastly, electron microscopy revealed significantly shorter inner and outer segments and immunofluorescence showed modest reductions in specific cell type populations. We did not observe any obvious functional or morphological defects in the adult Rho-iCre75 Lsd1fl/fl animals. Conclusion Lsd1 is necessary for neuronal development in the retina. Adult Chx10-Cre Lsd1fl/fl mice show impaired retinal function and morphology. These effects were fully manifested in young adults (P30), suggesting that Lsd1 affects early retinal development in mice.
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Affiliation(s)
- Salma Ferdous
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | | | - Tatiana E. Getz
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Nancy L’Hernault
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Jana T. Sellers
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Vivian R. Summers
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Jeremy M. Boss
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, United States
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
- Atlanta Veterans Administration Center for Visual and Neurocognitive Rehabilitation, Decatur, GA, United States
| | - John M. Nickerson
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
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DeVera C, Dixon J, Chrenek MA, Baba K, Le YZ, Iuvone PM, Tosini G. The Circadian Clock in the Retinal Pigment Epithelium Controls the Diurnal Rhythm of Phagocytic Activity. Int J Mol Sci 2022; 23:5302. [PMID: 35628111 PMCID: PMC9141420 DOI: 10.3390/ijms23105302] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 04/26/2022] [Accepted: 05/03/2022] [Indexed: 02/04/2023] Open
Abstract
The diurnal peak of phagocytosis by the retinal pigment epithelium (RPE) of photoreceptor outer segments (POS) is under circadian control and believed that this process involves interactions from the retina and RPE. Previous studies have demonstrated that a functional circadian clock exists within multiple retinal cell types and RPE. Thereby, the aim of this study was to determine whether the clock in the retina or RPE controls the diurnal phagocytic peak and whether disruption of the circadian clock in the RPE would affect cellular function and the viability during aging. To that, we generated and validated an RPE tissue-specific KO of the essential clock gene, Bmal1, and then determined the daily rhythm in phagocytic activity by the RPE in mice lacking a functional circadian clock in the retina or RPE. Then, using electroretinography, spectral domain-optical coherence tomography, and optomotor response of visual function we determined the effect of Bmal1 removal in young (6 months) and old (18 months) mice. RPE morphology and lipofuscin accumulation was determined in young and old mice. Our data shows that the clock in the RPE, rather than the retina clock, controls the diurnal phagocytic peak. Surprisingly, absence of a functional RPE clock and phagocytic peak does not result in any detectable age-related degenerative phenotype in the retina or RPE. Thus, our results demonstrate that the circadian clock in the RPE controls the daily peak of phagocytic activity. However, the absence of the clock in the RPE does not result in deterioration of photoreceptors or the RPE during aging.
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Affiliation(s)
- Christopher DeVera
- Department of Pharmacology & Toxicology and Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA; (C.D.); (K.B.)
| | - Jendayi Dixon
- Department of Ophthalmology and Emory Eye Center, Emory University School of Medicine, Atlanta, GA 30322, USA; (J.D.); (M.A.C.); (P.M.I.)
| | - Micah A. Chrenek
- Department of Ophthalmology and Emory Eye Center, Emory University School of Medicine, Atlanta, GA 30322, USA; (J.D.); (M.A.C.); (P.M.I.)
| | - Kenkichi Baba
- Department of Pharmacology & Toxicology and Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA; (C.D.); (K.B.)
| | - Yun Z. Le
- Departments of Medicine, Cell Biology, and Ophthalmology and Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
| | - P. Michael Iuvone
- Department of Ophthalmology and Emory Eye Center, Emory University School of Medicine, Atlanta, GA 30322, USA; (J.D.); (M.A.C.); (P.M.I.)
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Gianluca Tosini
- Department of Pharmacology & Toxicology and Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA 30310, USA; (C.D.); (K.B.)
- Department of Ophthalmology and Emory Eye Center, Emory University School of Medicine, Atlanta, GA 30322, USA; (J.D.); (M.A.C.); (P.M.I.)
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Aung MH, Hogan K, Mazade RE, Park HN, Sidhu CS, Iuvone PM, Pardue MT. ON than OFF pathway disruption leads to greater deficits in visual function and retinal dopamine signaling. Exp Eye Res 2022; 220:109091. [PMID: 35487263 DOI: 10.1016/j.exer.2022.109091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/15/2022] [Accepted: 04/20/2022] [Indexed: 11/19/2022]
Abstract
The visual system uses ON and OFF pathways to signal luminance increments and decrements. Increasing evidence suggests that ON and OFF pathways have different signaling properties and serve specialized visual functions. However, it is still unclear the contribution of ON and OFF pathways to visual behavior. Therefore, we examined the effects on optomotor response and the retinal dopamine system in nob mice with ON pathway dysfunction and Vsx1-/- mice with partial OFF pathway dysfunction. Spatial frequency and contrast sensitivity thresholds were determined, and values were compared to age-matched wild-type controls. Retinas were collected immediately after visual testing to measure levels of dopamine and its metabolite, DOPAC. At 4 weeks of age, we found that nob mice had significantly reduced spatial frequency (19%) and contrast sensitivity (60%) thresholds compared to wild-type mice. Vsx1-/- mice also exhibited reductions in optomotor responses (3% in spatial frequency; 18% in contrast sensitivity) at 4 weeks, although these changes were significantly smaller than those found in nob mice. Furthermore, nob mice had significantly lower DOPAC levels (53%) and dopamine turnover (41%) compared to controls while Vsx1-/- mice displayed a transient increase in DOPAC levels at 4 weeks of age (55%). Our results show that dysfunction of ON pathways leads to reductions in contrast sensitivity, spatial frequency threshold, and retinal dopamine and DOPAC levels whereas partial loss of the OFF pathway has minimal effect. We conclude that ON pathways play a critical role in visual reflexes and retinal dopamine signaling, highlighting a potential association for future investigations.
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Affiliation(s)
- Moe H Aung
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, USA; Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, USA; Department of Ophthalmology, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Kelleigh Hogan
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, USA; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA, 30332, USA
| | - Reece E Mazade
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, USA; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA, 30332, USA
| | - Han Na Park
- Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, USA; Department of Ophthalmology, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA, 0322, USA
| | - Curran S Sidhu
- Department of Ophthalmology, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA, 0322, USA
| | - P Michael Iuvone
- Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, USA; Department of Ophthalmology, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA, 0322, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA, 30033, USA; Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA, 30322, USA; Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA, 30332, USA; Department of Ophthalmology, Emory University School of Medicine, 1365 Clifton Road NE, Atlanta, GA, 0322, USA.
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Chakraborty R, Landis EG, Mazade R, Yang V, Strickland R, Hattar S, Stone RA, Iuvone PM, Pardue MT. Melanopsin modulates refractive development and myopia. Exp Eye Res 2022; 214:108866. [PMID: 34838844 PMCID: PMC8792255 DOI: 10.1016/j.exer.2021.108866] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023]
Abstract
Myopia, or nearsightedness, is the most common form of refractive abnormality and is characterized by excessive ocular elongation in relation to ocular power. Retinal neurotransmitter signaling, including dopamine, is implicated in myopic ocular growth, but the visual pathways that initiate and sustain myopia remain unclear. Melanopsin-expressing retinal ganglion cells (mRGCs), which detect light, are important for visual function, and have connections with retinal dopamine cells. Here, we investigated how mRGCs influence normal and myopic refractive development using two mutant mouse models: Opn4-/- mice that lack functional melanopsin photopigments and intrinsic mRGC responses but still receive other photoreceptor-mediated input to these cells; and Opn4DTA/DTA mice that lack intrinsic and photoreceptor-mediated mRGC responses due to mRGC cell death. In mice with intact vision or form-deprivation, we measured refractive error, ocular properties including axial length and corneal curvature, and the levels of retinal dopamine and its primary metabolite, L-3,4-dihydroxyphenylalanine (DOPAC). Myopia was measured as a myopic shift, or the difference in refractive error between the form-deprived and contralateral eyes. We found that Opn4-/- mice had altered normal refractive development compared to Opn4+/+ wildtype mice, starting ∼4D more myopic but developing ∼2D greater hyperopia by 16 weeks of age. Consistent with hyperopia at older ages, 16 week-old Opn4-/- mice also had shorter eyes compared to Opn4+/+ mice (3.34 vs 3.42 mm). Opn4DTA/DTA mice, however, were more hyperopic than both Opn4+/+ and Opn4-/- mice across development ending with even shorter axial lengths. Despite these differences, both Opn4-/- and Opn4DTA/DTA mice had ∼2D greater myopic shifts in response to form-deprivation compared to Opn4+/+ mice. Furthermore, when vision was intact, dopamine and DOPAC levels were similar between Opn4-/- and Opn4+/+ mice, but higher in Opn4DTA/DTA mice, which differed with age. However, form-deprivation reduced retinal dopamine and DOAPC by ∼20% in Opn4-/- compared to Opn4+/+ mice but did not affect retinal dopamine and DOPAC in Opn4DTA/DTA mice. Lastly, systemically treating Opn4-/- mice with the dopamine precursor L-DOPA reduced their form-deprivation myopia by half compared to non-treated mice. Collectively our findings show that disruption of retinal melanopsin signaling alters the rate and magnitude of normal refractive development, yields greater susceptibility to form-deprivation myopia, and changes dopamine signaling. Our results suggest that mRGCs participate in the eye's response to myopigenic stimuli, acting partly through dopaminergic mechanisms, and provide a potential therapeutic target underling myopia progression. We conclude that proper mRGC function is necessary for correct refractive development and protection from myopia progression.
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Affiliation(s)
- Ranjay Chakraborty
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA 30322, United States,Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA 30033, United States,College of Nursing and Health Sciences, Optometry and Vision Science, Flinders University, Bedford Park, SA 5001, Adelaide, Australia,Caring Futures Institute, Flinders University, Bedford Park, SA 5042, Adelaide, Australia
| | - Erica G. Landis
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA 30322, United States,Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA 30033, United States,Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA 30322, United States
| | - Reece Mazade
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA 30033, United States,Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA 30332, United States
| | - Victoria Yang
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA 30033, United States,Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA 30332, United States
| | - Ryan Strickland
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA 30033, United States,Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA 30322, United States
| | - Samer Hattar
- Section on Light and Circadian Rhythms, NIMH, NIH, 9000 Rockville Pike, Bethesda, Maryland, USA 20892
| | - Richard A. Stone
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA 30322, United States,Department of Pharmacology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA 30322, United States
| | - Machelle T. Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Health Care System, 1670 Clairmont Rd, Decatur, GA 30033, United States,Neuroscience Program, Emory University School of Medicine, 1365 Clifton Rd NE, Atlanta, GA 30322, United States,Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA 30332, United States
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7
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Dhakal S, He L, Lyuboslavsky P, Sidhu C, Chrenek MA, Sellers JT, Boatright JH, Geisert EE, Setterholm NA, McDonald FE, Iuvone PM. A Tropomycin-Related Kinase B Receptor Activator for the Management of Ocular Blast-Induced Vision Loss. J Neurotrauma 2021; 38:2896-2906. [PMID: 34353120 PMCID: PMC8820286 DOI: 10.1089/neu.2020.7392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pressure waves from explosions or other traumatic events can damage the neurons of the eye and visual centers of the brain, leading to functional loss of vision. There are currently few treatments for such injuries that can be deployed rapidly to mitigate damage. Brain-derived neurotrophic factor (BDNF) and activation of its receptor tropomycin-related kinase B (TrkB) have neuroprotective effects in a number of degeneration models. Small molecule activators of TrkB, such as N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC), cross the blood-brain and blood-retina barriers after systemic administration. We characterize the effects of blast-induced ocular trauma on retinal and visual function. We show that systemic administration of HIOC, a potent small molecule activator of the BDNF/TrkB receptor, preserves visual function in mice exposed to ocular blast injury. The HIOC treatment for one week preserves visual function for at least four months. The HIOC treatment effectively protected vision when the initial dose was administered up to 3 h after blast, but not if the initial treatment was delayed for 24 h. We provide evidence that the therapeutic effect of HIOC is mediated by activation of BDNF/TrkB receptors. The results indicate that HIOC may be useful for managing ocular blast injury and other forms of traumatic optic neuropathy.
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Affiliation(s)
- Susov Dhakal
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Li He
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | - Curran Sidhu
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Jana T. Sellers
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | - Eldon E. Geisert
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | | | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, USA
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8
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Landis EG, Park HN, Chrenek M, He L, Sidhu C, Chakraborty R, Strickland R, Iuvone PM, Pardue MT. Ambient Light Regulates Retinal Dopamine Signaling and Myopia Susceptibility. Invest Ophthalmol Vis Sci 2021; 62:28. [PMID: 33502461 PMCID: PMC7846952 DOI: 10.1167/iovs.62.1.28] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purpose Exposure to high-intensity or outdoor lighting has been shown to decrease the severity of myopia in both human epidemiological studies and animal models. Currently, it is not fully understood how light interacts with visual signaling to impact myopia. Previous work performed in the mouse retina has demonstrated that functional rod photoreceptors are needed to develop experimentally-induced myopia, alluding to an essential role for rod signaling in refractive development. Methods To determine whether dim rod-dominated illuminance levels influence myopia susceptibility, we housed male C57BL/6J mice under 12:12 light/dark cycles with scotopic (1.6 × 10−3 candela/m2), mesopic (1.6 × 101 cd/m2), or photopic (4.7 × 103 cd/m2) lighting from post-natal day 23 (P23) to P38. Half the mice received monocular exposure to −10 diopter (D) lens defocus from P28–38. Molecular assays to measure expression and content of DA-related genes and protein were conducted to determine how illuminance and lens defocus alter dopamine (DA) synthesis, storage, uptake, and degradation and affect myopia susceptibility in mice. Results We found that mice exposed to either scotopic or photopic lighting developed significantly less severe myopic refractive shifts (lens treated eye minus contralateral eye; –1.62 ± 0.37D and −1.74 ± 0.44D, respectively) than mice exposed to mesopic lighting (–3.61 ± 0.50D; P < 0.005). The 3,4-dihydroxyphenylacetic acid /DA ratio, indicating DA activity, was highest under photopic light regardless of lens defocus treatment (controls: 0.09 ± 0.011 pg/mg, lens defocus: 0.08 ± 0.008 pg/mg). Conclusions Lens defocus interacted with ambient conditions to differentially alter myopia susceptibility and DA-related genes and proteins. Collectively, these results show that scotopic and photopic lighting protect against lens-induced myopia, potentially indicating that a broad range of light levels are important in refractive development.
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Affiliation(s)
- Erica G Landis
- Department of Neuroscience, Emory University, Atlanta, Georgia, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Atlanta, Georgia, United States
| | - Han Na Park
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Micah Chrenek
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Li He
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Curran Sidhu
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Ranjay Chakraborty
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Atlanta, Georgia, United States
| | - Ryan Strickland
- Department of Neuroscience, Emory University, Atlanta, Georgia, United States
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.,Department of Pharmacology, Emory University, Atlanta, Georgia, United States
| | - Machelle T Pardue
- Department of Neuroscience, Emory University, Atlanta, Georgia, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Atlanta, Georgia, United States.,Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States
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9
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Goyal V, DeVera C, Baba K, Sellers J, Chrenek MA, Iuvone PM, Tosini G. Photoreceptor Degeneration in Homozygous Male Per2 luc Mice During Aging. J Biol Rhythms 2020; 36:137-145. [PMID: 33135952 DOI: 10.1177/0748730420965285] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Per2luc mouse model developed by Takahashi laboratory is one of the most powerful models to study circadian rhythms in real time. In this study, we report that photoreceptors degenerate in male Per2luc mice during aging. Young (2.5- to 5-month-old) and aged (11- to 13.5-month-old) homozygous male Per2luc mice and C57BL/6J mice were used for this study. Retina structure and function were investigated via spectral domain optical coherence tomography (SD-OCT), fundus imaging, and electroretinography (ERG). Zonula occludens-1 (ZO-1) immunofluorescence was used to analyze the retinal pigment epithelium (RPE) morphology. Fundus examination revealed no difference between young Per2luc and wild-type (WT) mice. However, the fundus of aged Per2luc mice showed white deposits, suggestive of age-related drusen-like formation or microglia, which were absent in age-matched WT mice. No differences in retinal structure and function were observed between young Per2luc and WT mice. However, with age, Per2luc mice showed a significant reduction in total retinal thickness with respect to C57BL/6J mice. The reduction was mostly confined to the photoreceptor layer. Consistent with these results, we observed a significant decrease in the amplitude of a- and b-waves of the ERG in aged Per2luc mice. Analysis of the RPE morphology revealed that in aged Per2luc mice there was an increase in compactness and eccentricity with a decrease in solidity with respect to the values observed in WT, pointing toward signs of aging in the RPE of Per2luc mice. Our data demonstrate that homozygous Per2luc mice show photoreceptor degeneration during aging and a premature aging of the RPE.
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Affiliation(s)
- Varunika Goyal
- Neuroscience Institute, Department of Pharmacology & Toxicology, Morehouse School of Medicine, Atlanta, Georgia
| | - Christopher DeVera
- Neuroscience Institute, Department of Pharmacology & Toxicology, Morehouse School of Medicine, Atlanta, Georgia
| | - Kenkichi Baba
- Neuroscience Institute, Department of Pharmacology & Toxicology, Morehouse School of Medicine, Atlanta, Georgia
| | - Jana Sellers
- Department of Ophthalmology, Emory Eye Center, Emory University, Atlanta, Georgia
| | - Micah A Chrenek
- Department of Ophthalmology, Emory Eye Center, Emory University, Atlanta, Georgia
| | - P Michael Iuvone
- Department of Ophthalmology, Emory Eye Center, Emory University, Atlanta, Georgia
| | - Gianluca Tosini
- Neuroscience Institute, Department of Pharmacology & Toxicology, Morehouse School of Medicine, Atlanta, Georgia.,Department of Ophthalmology, Emory Eye Center, Emory University, Atlanta, Georgia
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10
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Chang E, Fu C, Coon SL, Alon S, Bozinoski M, Breymaier M, Bustos DM, Clokie SJ, Gothilf Y, Esnault C, Michael Iuvone P, Mason CE, Ochocinska MJ, Tovin A, Wang C, Xu P, Zhu J, Dale R, Klein DC. Resource: A multi-species multi-timepoint transcriptome database and webpage for the pineal gland and retina. J Pineal Res 2020; 69:e12673. [PMID: 32533862 PMCID: PMC7513311 DOI: 10.1111/jpi.12673] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 01/12/2023]
Abstract
The website and database https://snengs.nichd.nih.gov provides RNA sequencing data from multi-species analysis of the pineal glands from zebrafish (Danio rerio), chicken (White Leghorn), rat (Rattus novegicus), mouse (Mus musculus), rhesus macaque (Macaca mulatta), and human (Homo sapiens); in most cases, retinal data are also included along with results of the analysis of a mixture of RNA from tissues. Studies cover day and night conditions; in addition, a time series over multiple hours, a developmental time series and pharmacological experiments on rats are included. The data have been uniformly re-processed using the latest methods and assemblies to allow for comparisons between experiments and to reduce processing differences. The website presents search functionality, graphical representations, Excel tables, and track hubs of all data for detailed visualization in the UCSC Genome Browser. As more data are collected from investigators and improved genomes become available in the future, the website will be updated. This database is in the public domain and elements can be reproduced by citing the URL and this report. This effort makes the results of 21st century transcriptome profiling widely available in a user-friendly format that is expected to broadly influence pineal research.
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Affiliation(s)
- Eric Chang
- Bioinformatics and Scientific Programming CoreEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Cong Fu
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Key Laboratory of Organ Regeneration & Transplantation of the Ministry of EducationThe First Hospital of Jilin UniversityChangchunChina
- Laboratory of Theoretical and Computational ChemistryInstitute of Theoretical ChemistryJilin UniversityChangchunChina
- National‐Local Joint Engineering Laboratory of Animal Models for Human DiseasesChangchunChina
| | - Steven L. Coon
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Molecular Genomics CoreOffice of the Scientific DirectorEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Shahar Alon
- Department of NeurobiologyThe George S. Wise Faculty of Life Sciences, and Sagol School of NeuroscienceTel‐Aviv UniversityTel AvivIsrael
- Present address:
The Alexander Kofkin Faculty of EngineeringBar‐Ilan UniversityRamat‐GanIsrael
| | - Marjan Bozinoski
- Department of Physiology and Biophysics and the Institute for Computational BiomedicineWeill Cornell Medical CollegeNew YorkNYUSA
| | - Matthew Breymaier
- Computer Support Services CoreEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - Diego M. Bustos
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Present address:
Instituto de Histología y Embriología de MendozaConsejo Nacional de Investigaciones Científicas y TécnicasMendozaArgentina
| | - Samuel J. Clokie
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Present address:
West Midlands Regional Genetics LaboratoriesBirmingham, Women’s and Children’s NHS Foundation TrustBirminghamUK
| | - Yoav Gothilf
- Department of NeurobiologyThe George S. Wise Faculty of Life Sciences, and Sagol School of NeuroscienceTel‐Aviv UniversityTel AvivIsrael
| | - Caroline Esnault
- Bioinformatics and Scientific Programming CoreEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - P. Michael Iuvone
- Departments of Ophthalmology and Pharmacology & Chemical BiologyEmory University School of MedicineAtlantaGAUSA
| | - Christopher E. Mason
- Department of Physiology and Biophysics and the Institute for Computational BiomedicineWeill Cornell Medical CollegeNew YorkNYUSA
| | - Margaret J. Ochocinska
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Present address:
National Heart, Lung and Blood InstituteNational Institutes of HealthBethesdaMDUSA
| | - Adi Tovin
- Department of NeurobiologyThe George S. Wise Faculty of Life Sciences, and Sagol School of NeuroscienceTel‐Aviv UniversityTel AvivIsrael
- Present address:
The Faculty of Life SciencesBar‐Ilan UniversityRamat‐GanIsrael
| | - Charles Wang
- Center for GenomicsSchool of MedicineLoma Linda UniversityLoma LindaCAUSA
| | - Pinxian Xu
- Department of Genetics and Genomic SciencesMount Sinai School of Medicine Icahn Medical InstituteNew YorkNYUSA
| | - Jinhang Zhu
- United States Food and Drug Administration’s National Center for Toxicological Research, Food and Drug AdministrationJeffersonARUSA
- Department of PhysiologySchool of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Ryan Dale
- Bioinformatics and Scientific Programming CoreEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
| | - David C. Klein
- Section on NeuroendocrinologyProgram in Developmental Endocrinology and GeneticsEunice Shriver Kennedy National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
- Office of the Scientific DirectorEunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMDUSA
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11
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Goyal V, DeVera C, Laurent V, Sellers J, Chrenek MA, Hicks D, Baba K, Iuvone PM, Tosini G. Dopamine 2 Receptor Signaling Controls the Daily Burst in Phagocytic Activity in the Mouse Retinal Pigment Epithelium. Invest Ophthalmol Vis Sci 2020; 61:10. [PMID: 32396631 PMCID: PMC7405625 DOI: 10.1167/iovs.61.5.10] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Purpose A burst in phagocytosis of spent photoreceptor outer fragments by RPE is a rhythmic process occurring 1 to 2 hours after the onset of light. This phenomenon is considered crucial for the health of the photoreceptors and RPE. We have recently reported that dopamine, via dopamine 2 receptor (D2R), shifts the circadian rhythm in the RPE. Methods Here, we first investigated the impact of the removal of D2R on the daily peak of phagocytosis by RPE and then we analyzed the function and morphology of retina and RPE in the absence of D2R. Results D2R knockout (KO) mice do not show a daily burst of phagocytic activity after the onset of light. RNA sequencing revealed a total of 394 differentially expressed genes (DEGs) between ZT 23 and ZT 1 in the control mice, whereas in D2R KO mice, we detected 1054 DEGs. Pathway analysis of the gene expression data implicated integrin signaling to be one of the upregulated pathways in control but not in D2R KO mice. Consistent with the gene expression data, phosphorylation of focal adhesion kinase (FAK) did not increase significantly in KO mice at ZT 1. No difference in retinal thickness, visual function, or morphology of RPE cells was observed between wild-type (WT) and D2R KO mice at the age of 3 and 12 months. Conclusions Our data suggest that removal of D2R prevents the burst of phagocytosis and a related increase in the phosphorylation of FAK after light onset. The pathway analysis points toward a putative role of D2R in controlling integrin signaling, which is known to play an important role in the control of the daily burst of phagocytosis by the RPE. Our data also indicate that the absence of the burst of phagocytic activity in the early morning does not produce any apparent deleterious effect on the retina or RPE up to 1 year of age.
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12
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Nickla DL, Sarfare S, McGeehan B, Wei W, Elin-Calcador J, He L, Dhakal S, Dixon J, Maguire MG, Stone RA, Iuvone PM. Visual conditions affecting eye growth alter diurnal levels of vitreous DOPAC. Exp Eye Res 2020; 200:108226. [PMID: 32905843 DOI: 10.1016/j.exer.2020.108226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/26/2020] [Accepted: 09/03/2020] [Indexed: 11/27/2022]
Abstract
In chicks, the diurnal patterns of retinal dopamine synthesis and release are associated with refractive development. To assess the within-day patterns of dopamine release, we assayed vitreal levels of DOPAC (3,4-dihydroxyphenylacetic acid) using high performance liquid chromatography with electrochemical detection, at 4-h intervals over 24 h in eyes with experimental manipulations that change ocular growth rates. Chicks were reared under a 12 h light/12 h dark cycle; experiments began at 12 days of age. Output was assessed by modelling using the robust variance structure of Generalized Estimating Equations. Continuous spectacle lensdefocus or form deprivation: One group experienced non-restricted visual input to both eyes and served as untreated "normal" controls. Three experimental cohorts underwent monocular visual alterations known to alter eye growth and refraction: wearing a diffuser, a negative lens or a positive lens. After one full day of device-wear, chicks were euthanized at 4-h intervals over 24 h (8 birds per time/condition). Brief hyperopic defocus: Chicks wore negative lenses for only 2 daily hours either in the morning (starting at ZT 0; n = 16) or mid-day (starting at ZT 4; n = 8) for 3 days. Vitreal DOPAC was assayed. In chicks with bilateral non-restricted vision, or with continuous defocus or form-deprivation, there was a diurnal variation in vitreal DOPAC levels for all eyes (p < 0.001 for each). In normal controls, DOPAC was highest during the daytime, lowest at night, and equivalent for both eyes. In experimental groups, regardless of whether experiencing a growth stimulatory input (diffuser; negative lens) or growth inhibitory input (positive lens), DOPAC levels were reduced compared both to fellow eyes and to those of normal controls (p < 0.001 for each). These diurnal variations in vitreous DOPAC levels under different visual conditions indicate a complexity for dopaminergic mechanisms in refractive development that requires further study.
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Affiliation(s)
- D L Nickla
- Department of Biosciences, The New England College of Optometry, Boston, MA, USA.
| | - S Sarfare
- Department of Biosciences, The New England College of Optometry, Boston, MA, USA
| | - B McGeehan
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - W Wei
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - J Elin-Calcador
- Department of Biosciences, The New England College of Optometry, Boston, MA, USA
| | - L He
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - S Dhakal
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - J Dixon
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - M G Maguire
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - R A Stone
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - P M Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Pharmacology & Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
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13
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Motz CT, Chesler KC, Allen RS, Bales KL, Mees LM, Feola AJ, Maa AY, Olson DE, Thule PM, Iuvone PM, Hendrick AM, Pardue MT. Novel Detection and Restorative Levodopa Treatment for Preclinical Diabetic Retinopathy. Diabetes 2020; 69:1518-1527. [PMID: 32051147 PMCID: PMC7306127 DOI: 10.2337/db19-0869] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 02/09/2020] [Indexed: 12/21/2022]
Abstract
Diabetic retinopathy (DR) is diagnosed clinically by directly viewing retinal vascular changes during ophthalmoscopy or through fundus photographs. However, electroretinography (ERG) studies in humans and rodents have revealed that retinal dysfunction is demonstrable prior to the development of visible vascular defects. Specifically, delays in dark-adapted ERG oscillatory potential (OP) implicit times in response to dim-flash stimuli (<-1.8 log cd · s/m2) occur prior to clinically recognized DR. Animal studies suggest that retinal dopamine deficiency underlies these early functional deficits. In this study, we randomized individuals with diabetes, without clinically detectable retinopathy, to treatment with either low- or high-dose Sinemet (levodopa plus carbidopa) for 2 weeks and compared their ERG findings with those of control subjects (no diabetes). We assessed dim-flash-stimulated OP delays using a novel handheld ERG system (RETeval) at baseline and 2 and 4 weeks. RETeval recordings identified significant OP implicit time delays in individuals with diabetes without retinopathy compared with age-matched control subjects (P < 0.001). After 2 weeks of Sinemet treatment, OP implicit times were restored to control values, and these improvements persisted even after a 2-week washout. We conclude that detection of dim-flash OP delays could provide early detection of DR and that Sinemet treatment may reverse retinal dysfunction.
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Affiliation(s)
- Cara T Motz
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
| | - Kyle C Chesler
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Katie L Bales
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
- Department of Ophthalmology, Emory University, Atlanta, GA
| | - Lukas M Mees
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
| | - Andrew J Feola
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - April Y Maa
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
- Department of Ophthalmology, Emory University, Atlanta, GA
| | - Darin E Olson
- Division of Endocrinology, Metabolism and Lipids, Emory University, Atlanta, GA
- Medical Service, Atlanta Veterans Affairs Medical Center, Decatur, GA
| | - Peter M Thule
- Division of Endocrinology, Metabolism and Lipids, Emory University, Atlanta, GA
- Medical Service, Atlanta Veterans Affairs Medical Center, Decatur, GA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, GA
| | | | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, GA
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA
- Department of Ophthalmology, Emory University, Atlanta, GA
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14
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Zhang S, Lyuboslavsky P, Dixon JA, Chrenek MA, Sellers JT, Hamm JM, Ribelayga CP, Zhang Z, Le YZ, Iuvone PM. Effects of Cone Connexin-36 Disruption on Light Adaptation and Circadian Regulation of the Photopic ERG. Invest Ophthalmol Vis Sci 2020; 61:24. [PMID: 32531058 PMCID: PMC7415284 DOI: 10.1167/iovs.61.6.24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 05/07/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose The present study tested the hypothesis that connexin-36 (Cx36) and gap junctions between photoreceptor cells contribute to the circadian rhythm of the photopic electroretinogram (ERG) b-wave amplitude. Methods Cone-specific disruption of Cx36 was obtained in mice with a floxed Gjd2 gene and human red/green pigment promoter (HRGP)-driven Cre recombinase. Standard ERG, spectral-domain optical coherence tomography (SD-OCT) and histochemical methods were used. Results HRGPcreGjd2fl/fl mice had a selective reduction in Cx36 protein in the outer plexiform layer; no reduction in Cx36 was observed in the inner plexiform layer. Cx36 disruption had no effect on the number of cones, the thickness of the photoreceptor layer, or the scotopic ERG responses. However, there was a reduction of the photopic ERG circadian rhythm, with b-wave amplitudes in the day and the night locked in the daytime, light-adapted state. In HRGPcreGjd2+/+and Gjd2fl/fl controls, the circadian rhythm of light-adapted ERG persisted, similar to that in wild type mice. Conclusions Cx36 regulation contributes to the circadian rhythm of light-adapted ERG; in the absence of photoreceptor gap junctions, mice appear to be in a fully light-adapted state regardless of the time of day. The higher amplitudes and reduced circadian regulation of the b-wave of HRGPcreGjd2fl/fl mice may be due to increased synaptic strength at the cone to ON bipolar cell synapse due to electrotonic isolation of the terminals lacking gap junctions.
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Affiliation(s)
- Shuo Zhang
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Capital Medical University, Beijing, China
| | - Polina Lyuboslavsky
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
| | - Jendayi Azeezah Dixon
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
| | - Jana T. Sellers
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
| | - Jessica M. Hamm
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
| | - Christophe P. Ribelayga
- Ruiz Department of Ophthalmology & Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, United States
| | - Zhijing Zhang
- Ruiz Department of Ophthalmology & Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, United States
| | - Yun Z. Le
- Departments of Medicine, Cell Biology, and Ophthalmology and Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, School of Medicine, Atlanta, Georgia, United States
- Department of Pharmacology, Emory University, School of Medicine, Atlanta, Georgia, United States
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15
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Stone RA, Wei W, Sarfare S, McGeehan B, Engelhart KC, Khurana TS, Maguire MG, Iuvone PM, Nickla DL. Visual Image Quality Impacts Circadian Rhythm-Related Gene Expression in Retina and in Choroid: A Potential Mechanism for Ametropias. Invest Ophthalmol Vis Sci 2020; 61:13. [PMID: 32396635 PMCID: PMC7405616 DOI: 10.1167/iovs.61.5.13] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/21/2020] [Indexed: 12/11/2022] Open
Abstract
Purpose Stimulated by evidence implicating diurnal/circadian rhythms and light in refractive development, we studied the expression over 24 hours of selected clock and circadian rhythm-related genes in retina/retinal pigment epithelium (RPE) and choroid of experimental ametropias in chicks. Methods Newly hatched chicks, entrained to a 12-hour light/dark cycle for 12 to 14 days, either experienced nonrestricted vision OU (i.e., in both eyes) or received an image-blurring diffuser or a minus 10-diopter (D) or a plus 10-D defocusing lens over one eye. Starting 1 day later and at 4-hour intervals for 24 hours, the retina/RPE and choroid were separately dissected. Without pooling, total RNA was extracted, converted to cDNA, and assayed by quantitative PCR for the expression of the following genes: Opn4m, Clock, Npas2, Per3, Cry1, Arntl, and Mtnr1a. Results The expression of each gene in retina/RPE and in choroid of eyes with nonrestricted vision OU varied over 24 hours, with equal levels OU for most genes and times. Altered visual input influenced gene expression in complex patterns that varied by gene, visual input, time, and eye, affecting experimental eyes with altered vision and also contralateral eyes with nonrestricted vision. Discussion Altering visual input in ways known to induce ametropias alters the retinal/RPE and choroidal expression of circadian rhythm-related genes, further linking circadian biology with eye growth regulation. While further investigations are needed, studying circadian processes may help understand refractive mechanisms and the increasing myopia prevalence in contemporary societies where lighting patterns can desynchronize endogenous rhythms from the natural environmental light/dark cycle.
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Affiliation(s)
- Richard A. Stone
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Wenjie Wei
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Shanta Sarfare
- Department of Bioscience, New England College of Optometry, Boston, Massachusetts, United States
| | - Brendan McGeehan
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - K. Cameron Engelhart
- Department of Bioscience, New England College of Optometry, Boston, Massachusetts, United States
| | - Tejvir S. Khurana
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Maureen G. Maguire
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - P. Michael Iuvone
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Debora L. Nickla
- Department of Bioscience, New England College of Optometry, Boston, Massachusetts, United States
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16
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Hendrick A, Smith J, Stelton C, Barb S, Yan J, Cribbs B, Jain N, Yeh S, Hubbard GB, He L, Dhakal S, Iuvone PM. Dopamine metabolite levels in the vitreous of diabetic and non-diabetic humans. Exp Eye Res 2020; 195:108040. [PMID: 32360553 DOI: 10.1016/j.exer.2020.108040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/03/2020] [Accepted: 04/21/2020] [Indexed: 01/12/2023]
Abstract
Animal studies suggest that the retinal dysfunction in diabetic subjects that precedes overt clinical vasculopathy may be due to a retinal dopamine deficit. We analyzed levels of dopamine (DA) and its primary metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), in the vitreous of diabetic and non-diabetic human subjects. Adult patients undergoing pars plana vitrectomy for non-hemorrhagic indications were prospectively recruited from the Emory Eye Center in Atlanta, GA. Vitreous samples were analyzed using high performance liquid chromatography (HPLC) to measure levels of DOPAC and DA in the vitreous specimens. Vitreous samples from 9 diabetic patients and 20 from non-diabetic patients were analyzed. No eyes had apparent diabetic retinopathy. Mean normalized DA concentration in vitreous of diabetic subjects was 0.76 ± 0.12 pg/μL vs. 0.73 ± 0.08 pg/μL in non-diabetic vitreous (p = 0.849). DOPAC concentration was 8.84 ± 0.74 pg/μL in vitreous of diabetic subjects vs. 9.22 ± 0.56 pg/μL in vitreous of non-diabetic subjects (p = 0.691). No difference was observed in the concentrations of DA and DOPAC in the vitreous of people without diabetes compared to those with diabetes without retinopathy.
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Affiliation(s)
- Andrew Hendrick
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA.
| | - Jesse Smith
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Chris Stelton
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Scott Barb
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Jiong Yan
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Blaine Cribbs
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Nieraj Jain
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Steve Yeh
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - G Baker Hubbard
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Li He
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Susov Dhakal
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory Eye Center, Emory University School of Medicine, Atlanta, GA, USA; Department Pharmacology and Chemical Biology, Emory University School of Medicine, Atlanta, GA, USA
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17
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Vancura P, Csicsely E, Leiser A, Iuvone PM, Spessert R. Rhythmic Regulation of Photoreceptor and RPE Genes Important for Vision and Genetically Associated With Severe Retinal Diseases. Invest Ophthalmol Vis Sci 2019; 59:3789-3799. [PMID: 30073352 PMCID: PMC6071477 DOI: 10.1167/iovs.18-24558] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The aim of the present study was to identify candidate genes for mediating daily adjustment of vision. Methods Genes important for vision and genetically associated with severe retinal diseases were tested for 24-hour rhythms in transcript levels in neuronal retina, microdissected photoreceptors, photoreceptor-related pinealocytes, and retinal pigment epithelium-choroid (RPE-choroid) complex by using quantitative PCR. Results Photoreceptors of wildtype mice display circadian clock-dependent regulation of visual arrestins (Arr1, Arr4) and the visual cycle gene Rdh12, whereas cells of the RPE-choroid exhibit light-dependent regulation of the visual cycle key genes Lrat, Rpe65, and Rdh5. Clock-driven rhythmicity of Arr1, Arr4, and Rdh12 was observed also in rat pinealocytes, to persist in a mouse model of diabetic retinopathy (db/db) and, in the case of Arr1, to be abolished in retinae of mice deficient for dopamine D4 receptors. Therefore, the expression rhythms appear to be evolutionary conserved, to be unaffected in diabetic retinopathy, and, for Arr1, to require dopamine signaling via dopamine D4 receptors. Conclusions The data of the present study suggest that daily adjustment of retinal function combines clock-dependent regulation of genes responsible for phototransduction termination (Arr1, Arr4) and detoxification (Rdh12) in photoreceptors with light-dependent regulation of genes responsible for retinoid recycling (Lrat, Rpe65, and Rdh5) in RPE. Furthermore, they indicate circadian and light-dependent regulation of genes genetically associated with severe retinal diseases.
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Affiliation(s)
- Patrick Vancura
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Erika Csicsely
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Annalisa Leiser
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Rainer Spessert
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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18
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Nguyen MTT, Vemaraju S, Nayak G, Odaka Y, Buhr ED, Alonzo N, Tran U, Batie M, Upton BA, Darvas M, Kozmik Z, Rao S, Hegde RS, Iuvone PM, Van Gelder RN, Lang RA. An opsin 5-dopamine pathway mediates light-dependent vascular development in the eye. Nat Cell Biol 2019; 21:420-429. [PMID: 30936473 PMCID: PMC6573021 DOI: 10.1038/s41556-019-0301-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 02/19/2019] [Indexed: 02/07/2023]
Abstract
During mouse postnatal eye development, the embryonic hyaloid vascular network regresses from the vitreous as an adaption for high acuity vision. This process occurs with precisely controlled timing. Here we show that an Opsin 5 (OPN5, Neuropsin)-dependent retinal light response regulates vascular development in the postnatal eye. In Opn5 null mice hyaloid vessels regress precociously. We demonstrate that 380 nm light stimulation via OPN5 and VGAT (the vesicular GABA/glycine transporter) in retinal ganglion cells enhances activity of inner retinal DAT/SLC6A3 (a dopamine reuptake transporter) and thus suppresses vitreal dopamine. In turn, dopamine acts directly on hyaloid vascular endothelial cells to suppress activity of VEGFR2 and promote hyaloid vessel regression. With OPN5 loss-of-function, vitreous dopamine is elevated and results in premature hyaloid regression. These investigations identify violet light as a developmental timing cue that, via an OPN5-dopamine pathway, regulates optic axis clearance in preparation for visual function.
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Affiliation(s)
- Minh-Thanh T Nguyen
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Center for Chronobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Shruti Vemaraju
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Center for Chronobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Gowri Nayak
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Center for Chronobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Yoshinobu Odaka
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Center for Chronobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Ethan D Buhr
- Department of Ophthalmology, University of Washington Medical School, Seattle, WA, USA
| | - Nuria Alonzo
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Uyen Tran
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Matthew Batie
- Clinical Engineering, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Brian A Upton
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,Center for Chronobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Martin Darvas
- Pathology, University of Washington Medical School, Seattle, WA, USA
| | - Zbynek Kozmik
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Sujata Rao
- Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Rashmi S Hegde
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA.,Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Russell N Van Gelder
- Department of Ophthalmology, University of Washington Medical School, Seattle, WA, USA.,Pathology, University of Washington Medical School, Seattle, WA, USA.,Biological Structure, University of Washington Medical School, Seattle, WA, USA
| | - Richard A Lang
- The Visual Systems Group, Abrahamson Pediatric Eye Institute, Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. .,Center for Chronobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. .,Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA. .,Department of Ophthalmology, University of Cincinnati, College of Medicine, Cincinnati, OH, USA.
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19
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Chakraborty R, Yang V, Park HN, Landis EG, Dhakal S, Motz CT, Bergen MA, Iuvone PM, Pardue MT. Lack of cone mediated retinal function increases susceptibility to form-deprivation myopia in mice. Exp Eye Res 2018; 180:226-230. [PMID: 30605665 DOI: 10.1016/j.exer.2018.12.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/18/2018] [Accepted: 12/29/2018] [Indexed: 11/30/2022]
Abstract
Retinal photoreceptors are important in visual signaling for normal eye growth in animals. We used Gnat2cplf3/cplf3 (Gnat2-/-) mice, a genetic mouse model of cone dysfunction to investigate the influence of cone signaling in ocular refractive development and myopia susceptibility in mice. Refractive development under normal visual conditions was measured for Gnat2-/- and age-matched Gnat2+/+ mice, every 2 weeks from 4 to 14 weeks of age. Weekly measurements were performed on a separate cohort of mice that underwent monocular form-deprivation (FD) in the right eye from 4 weeks of age using head-mounted diffusers. Refraction, corneal curvature, and ocular biometrics were obtained using photorefraction, keratometry and optical coherence tomography, respectively. Retinas from FD mice were harvested, and analyzed for dopamine (DA) and 3,4-dihydroxyphenylacetate (DOPAC) using high-performance liquid chromatography. Under normal visual conditions, Gnat2+/+ and Gnat2-/- mice showed similar refractive error, axial length, and corneal radii across development (p > 0.05), indicating no significant effects of the Gnat2 mutation on normal ocular refractive development in mice. Three weeks of FD produced a significantly greater myopic shift in Gnat2-/- mice compared to Gnat2+/+ controls (-5.40 ± 1.33 D vs -2.28 ± 0.28 D, p = 0.042). Neither the Gnat2 mutation nor FD altered retinal levels of DA or DOPAC. Our results indicate that cone pathways needed for high acuity vision in primates are not as critical for normal refractive development in mice, and that both rods and cones contribute to visual signalling pathways needed to respond to FD in mammalian eyes.
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Affiliation(s)
- Ranjay Chakraborty
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA; College of Nursing and Health Sciences, Flinders University, Bedford Park, SA, 5001, Adelaide, Australia
| | - Victoria Yang
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA
| | - Han Na Park
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA
| | - Erica G Landis
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA
| | - Susov Dhakal
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA
| | - Cara T Motz
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA
| | - Michael A Bergen
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA; Department of Pharmacology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA, 30322, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, 1670 Clairmont Rd, Decatur, GA, 30033, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Dr, Atlanta, GA, 30332, USA.
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20
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Baba K, Piano I, Lyuboslavsky P, Chrenek MA, Sellers JT, Zhang S, Gargini C, He L, Tosini G, Iuvone PM. Removal of clock gene Bmal1 from the retina affects retinal development and accelerates cone photoreceptor degeneration during aging. Proc Natl Acad Sci U S A 2018; 115:13099-13104. [PMID: 30498030 PMCID: PMC6305005 DOI: 10.1073/pnas.1808137115] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The mammalian retina contains an autonomous circadian clock system that controls many physiological functions within this tissue. Previous studies on young mice have reported that removal of the key circadian clock gene Bmal1 from the retina affects the circadian regulation of visual function, but does not affect photoreceptor viability. Because dysfunction in the circadian system is known to affect cell viability during aging in other systems, we compared the effect of Bmal1 removal from the retina on visual function, inner retinal structure, and photoreceptor viability in young (1 to 3 months) and aged (24 to 26 months) mice. We found that removal of Bmal1 from the retina significantly affects visual information processing in both rod and cone pathways, reduces the thickness of inner retinal nuclear and plexiform layers, accelerates the decline of visual functions during aging, and reduces the viability of cone photoreceptors. Our results thus suggest that circadian clock dysfunction, caused by genetic or other means, may contribute to the decline of visual function during development and aging.
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Affiliation(s)
- Kenkichi Baba
- Neuroscience Institute, Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495
| | - Ilaria Piano
- Neuroscience Institute, Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495
- Department of Pharmacy, University of Pisa, Pisa 56121, Italy
| | - Polina Lyuboslavsky
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013
| | - Micah A Chrenek
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013
| | - Jana T Sellers
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013
| | - Shuo Zhang
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
- Institute of Ophthalmology, Central South University, Changsha, Hunan 410008, China
| | - Claudia Gargini
- Department of Pharmacy, University of Pisa, Pisa 56121, Italy
| | - Li He
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Gianluca Tosini
- Neuroscience Institute, Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, GA 30310-1495;
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322-1013;
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322
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21
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Sankaran M, Keeley PW, He L, Iuvone PM, Reese BE. Dopaminergic amacrine cell number, plexus density, and dopamine content in the mouse retina: Strain differences and effects of Bax gene disruption. Exp Eye Res 2018; 177:208-212. [PMID: 30240584 DOI: 10.1016/j.exer.2018.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/07/2018] [Accepted: 09/17/2018] [Indexed: 01/01/2023]
Abstract
Many types of retinal neuron modulate the distribution of their processes to ensure a uniform coverage of the retinal surface. Dendritic field area, for instance, is inversely related to the variation in cellular density for many cell types, observed either across retinal eccentricity or between different strains of mice that differ in cell number. Dopaminergic amacrine (DA) cells, by contrast, have dendritic arbors that bear no spatial relationship to the presence of their immediate homotypic neighbors, yet it remains to be determined whether their coverage upon the retina, as a population, is conserved across variation in their total number. The present study assessed the overall density of the dopaminergic plexus in the inner plexiform layer in the presence of large variation in the total number of DA cells, as well as their retinal dopamine content, to determine whether either of these features is conserved. We first compared these traits between two strains of mice (C57BL/6J and A/J) that exhibit a two-fold difference in DA cell number. We subsequently examined these same traits in littermate mice for which the pro-apoptotic Bax gene was either intact or knocked out, yielding a five-fold difference in DA cell number. In both comparisons, we found greater plexus density and DA content in the strain or condition with the greater number of DA cells. The population of DA cells, therefore, does not appear to self-regulate its process coverage to achieve a constant density as the DA mosaic is established during development, nor its functional dopamine content in maturity.
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Affiliation(s)
- Mathangi Sankaran
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA; Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, 93106, USA
| | - Patrick W Keeley
- Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, 93106, USA
| | - Li He
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, 30322, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Benjamin E Reese
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA; Department of Psychological & Brain Sciences, University of California, Santa Barbara, CA, 93106, USA.
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22
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Kim MK, Aung MH, Mees L, Olson DE, Pozdeyev N, Iuvone PM, Thule PM, Pardue MT. Dopamine Deficiency Mediates Early Rod-Driven Inner Retinal Dysfunction in Diabetic Mice. Invest Ophthalmol Vis Sci 2018; 59:572-581. [PMID: 29372256 PMCID: PMC5788047 DOI: 10.1167/iovs.17-22692] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purpose Electroretinograms (ERGs) are abnormal in diabetic retinas before the appearance of vascular lesions, providing a possible biomarker for diabetic vision loss. Previously, we reported that decreased retinal dopamine (DA) levels in diabetic rodents contributed to early visual and retinal dysfunction. In the current study, we examined whether oscillatory potentials (OPs) could serve as a potential marker for detecting early inner retinal dysfunction due to retinal DA deficiency. Methods Retinal function was tested with dark-adapted ERGs, taken at 3, 4, and 5 weeks after diabetes induction with streptozotocin. Electrical responses were analyzed and correlations were made with previously reported retinal DA levels. The effect of restoring systemic DA levels or removing DA from the retina in diabetic mice on OPs was assessed using L-3,4-dihydroxyphenylalanine (L-DOPA) treatments and retina-specific tyrosine hydroxylase (Th) knockout mice (rTHKO), respectively. Results Diabetic animals had significantly delayed OPs compared to control animals in response to dim, but not bright, flash stimuli. L-DOPA treatment preserved OP implicit time in diabetic mice. Diabetic rTHKO mice had further delayed OPs compared to diabetic mice with normal retinal Th, with L-DOPA treatment also providing benefit. Decreasing retinal DA levels significantly correlated with increasing OP delays mediated by rod pathways. Conclusions Our data suggest that inner retinal dysfunction in early-stage diabetes is mediated by rod-pathway deficits and DA deficiencies. OP delays may be used to determine the earliest functional deficits in diabetic retinopathy and to establish an early treatment window for DA therapies that may prevent progressive vision loss.
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Affiliation(s)
- Moon K Kim
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
| | - Moe H Aung
- Neuroscience, Emory University, Atlanta, Georgia, United States
| | - Lukas Mees
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, Georgia, United States
| | - Darin E Olson
- Division of Endocrinology, Metabolism and Lipids, Emory University, Atlanta, Georgia, United States.,Medical Service, Atlanta Veterans Affairs Medical Center, Decatur, Georgia, United States
| | - Nikita Pozdeyev
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.,Department of Pharmacology, Emory University, Atlanta, Georgia, United States
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.,Neuroscience, Emory University, Atlanta, Georgia, United States.,Department of Pharmacology, Emory University, Atlanta, Georgia, United States
| | - Peter M Thule
- Division of Endocrinology, Metabolism and Lipids, Emory University, Atlanta, Georgia, United States.,Medical Service, Atlanta Veterans Affairs Medical Center, Decatur, Georgia, United States
| | - Machelle T Pardue
- Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.,Neuroscience, Emory University, Atlanta, Georgia, United States.,Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States.,Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Medical Center, Decatur, Georgia, United States
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23
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Kang SS, Ahn EH, Zhang Z, Liu X, Manfredsson FP, Sandoval IM, Dhakal S, Iuvone PM, Cao X, Ye K. α-Synuclein stimulation of monoamine oxidase-B and legumain protease mediates the pathology of Parkinson's disease. EMBO J 2018; 37:embj.201798878. [PMID: 29769405 DOI: 10.15252/embj.201798878] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 04/01/2018] [Accepted: 04/09/2018] [Indexed: 12/31/2022] Open
Abstract
Dopaminergic neurodegeneration in Parkinson's disease (PD) is associated with abnormal dopamine metabolism by MAO-B (monoamine oxidase-B) and intracellular α-Synuclein (α-Syn) aggregates, called the Lewy body. However, the molecular relationship between α-Syn and MAO-B remains unclear. Here, we show that α-Syn directly binds to MAO-B and stimulates its enzymatic activity, which triggers AEP (asparagine endopeptidase; legumain) activation and subsequent α-Syn cleavage at N103, leading to dopaminergic neurodegeneration. Interestingly, the dopamine metabolite, DOPAL, strongly activates AEP, and the N103 fragment of α-Syn binds and activates MAO-B. Accordingly, overexpression of AEP in SNCA transgenic mice elicits α-Syn N103 cleavage and accelerates PD pathogenesis, and inhibition of MAO-B by Rasagiline diminishes α-Syn-mediated PD pathology and motor dysfunction. Moreover, virally mediated expression of α-Syn N103 induces PD pathogenesis in wild-type, but not MAO-B-null mice. Our findings thus support that AEP-mediated cleavage of α-Syn at N103 is required for the association and activation of MAO-B, mediating PD pathogenesis.
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Affiliation(s)
- Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Eun Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Zhentao Zhang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA.,Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Fredric P Manfredsson
- Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Ivette M Sandoval
- Translational Science and Molecular Medicine, College of Human Medicine, Michigan State University, Grand Rapids, MI, USA
| | - Susov Dhakal
- Department of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - P Michael Iuvone
- Department of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Xuebing Cao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA, USA .,Translational Center for Stem Cell Research, Department of Regenerative Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China
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24
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Chakraborty R, Ostrin LA, Nickla DL, Iuvone PM, Pardue MT, Stone RA. Circadian rhythms, refractive development, and myopia. Ophthalmic Physiol Opt 2018; 38:217-245. [PMID: 29691928 PMCID: PMC6038122 DOI: 10.1111/opo.12453] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/11/2018] [Indexed: 12/14/2022]
Abstract
PURPOSE Despite extensive research, mechanisms regulating postnatal eye growth and those responsible for ametropias are poorly understood. With the marked recent increases in myopia prevalence, robust and biologically-based clinical therapies to normalize refractive development in childhood are needed. Here, we review classic and contemporary literature about how circadian biology might provide clues to develop a framework to improve the understanding of myopia etiology, and possibly lead to rational approaches to ameliorate refractive errors developing in children. RECENT FINDINGS Increasing evidence implicates diurnal and circadian rhythms in eye growth and refractive error development. In both humans and animals, ocular length and other anatomical and physiological features of the eye undergo diurnal oscillations. Systemically, such rhythms are primarily generated by the 'master clock' in the surpachiasmatic nucleus, which receives input from the intrinsically photosensitive retinal ganglion cells (ipRGCs) through the activation of the photopigment melanopsin. The retina also has an endogenous circadian clock. In laboratory animals developing experimental myopia, oscillations of ocular parameters are perturbed. Retinal signaling is now believed to influence refractive development; dopamine, an important neurotransmitter found in the retina, not only entrains intrinsic retinal rhythms to the light:dark cycle, but it also modulates refractive development. Circadian clocks comprise a transcription/translation feedback control mechanism utilizing so-called clock genes that have now been associated with experimental ametropias. Contemporary clinical research is also reviving ideas first proposed in the nineteenth century that light exposures might impact refraction in children. As a result, properties of ambient lighting are being investigated in refractive development. In other areas of medical science, circadian dysregulation is now thought to impact many non-ocular disorders, likely because the patterns of modern artificial lighting exert adverse physiological effects on circadian pacemakers. How, or if, such modern light exposures and circadian dysregulation contribute to refractive development is not known. SUMMARY The premise of this review is that circadian biology could be a productive area worthy of increased investigation, which might lead to the improved understanding of refractive development and improved therapeutic interventions.
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Affiliation(s)
- Ranjay Chakraborty
- College of Nursing and Health Sciences, Flinders University, Adelaide, Australia
| | | | | | | | - Machelle T. Pardue
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta
- Atlanta VA Center for Visual and Neurocognitive Rehabilitation, Decatur
| | - Richard A. Stone
- University of Pennsylvania School of Medicine, Philadelphia, USA
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Mui AM, Yang V, Aung MH, Fu J, Adekunle AN, Prall BC, Sidhu CS, Park HN, Boatright JH, Iuvone PM, Pardue MT. Daily visual stimulation in the critical period enhances multiple aspects of vision through BDNF-mediated pathways in the mouse retina. PLoS One 2018; 13:e0192435. [PMID: 29408880 PMCID: PMC5800661 DOI: 10.1371/journal.pone.0192435] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 01/22/2018] [Indexed: 12/14/2022] Open
Abstract
Visual experience during the critical period modulates visual development such that deprivation causes visual impairments while stimulation induces enhancements. This study aimed to determine whether visual stimulation in the form of daily optomotor response (OMR) testing during the mouse critical period (1) improves aspects of visual function, (2) involves retinal mechanisms and (3) is mediated by brain derived neurotrophic factor (BDNF) and dopamine (DA) signaling pathways. We tested spatial frequency thresholds in C57BL/6J mice daily from postnatal days 16 to 23 (P16 to P23) using OMR testing. Daily OMR-treated mice were compared to littermate controls that were placed in the OMR chamber without moving gratings. Contrast sensitivity thresholds, electroretinograms (ERGs), visual evoked potentials, and pattern ERGs were acquired at P21. To determine the role of BDNF signaling, a TrkB receptor antagonist (ANA-12) was systemically injected 2 hours prior to OMR testing in another cohort of mice. BDNF immunohistochemistry was performed on retina and brain sections. Retinal DA levels were measured using high-performance liquid chromatography. Daily OMR testing enhanced spatial frequency thresholds and contrast sensitivity compared to controls. OMR-treated mice also had improved rod-driven ERG oscillatory potential response times, greater BDNF immunoreactivity in the retinal ganglion cell layer, and increased retinal DA content compared to controls. VEPs and pattern ERGs were unchanged. Systemic delivery of ANA-12 attenuated OMR-induced visual enhancements. Daily OMR testing during the critical period leads to general visual function improvements accompanied by increased DA and BDNF in the retina, with this process being requisitely mediated by TrkB activation. These results suggest that novel combination therapies involving visual stimulation and using both behavioral and molecular approaches may benefit degenerative retinal diseases or amblyopia.
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Affiliation(s)
- Amanda M. Mui
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
| | - Victoria Yang
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Moe H. Aung
- Neuroscience Program, Emory University, Atlanta, GA, United States of America
| | - Jieming Fu
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
| | - Adewumi N. Adekunle
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
| | - Brian C. Prall
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
- Neuroscience Program, Emory University, Atlanta, GA, United States of America
| | - Curran S. Sidhu
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
| | - Han na Park
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Neuroscience Program, Emory University, Atlanta, GA, United States of America
- Department of Pharmacology, Emory University, Atlanta, GA, United States of America
| | - Machelle T. Pardue
- Department of Ophthalmology, Emory University, Atlanta, GA, United States of America
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, United States of America
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States of America
- Neuroscience Program, Emory University, Atlanta, GA, United States of America
- * E-mail:
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Abstract
Circadian rhythms are present in most living organisms, and these rhythms are not just a consequence of the day/night fluctuation, but rather they are generated by endogenous biological clocks with a periodicity of about 24 h. In mammals, the master pacemaker of circadian rhythms is localized in the suprachiasmatic nuclei (SCN) of the hypothalamus. The SCN controls circadian rhythms in peripheral organs. The retina also contains circadian clocks which regulate many aspects of retinal physiology, independently of the SCN. Emerging experimental evidence indicates that the retinal circadian clocks also affect ocular health, and a few studies have now demonstrated that disruption of retinal clocks may contribute to the development of retinal diseases. Our study indicates that in mice lacking the clock gene Bmal1, photoreceptor viability during aging is significantly reduced. Bmal1 knockout mice at 8-9 months of age have 20-30% less nuclei in the outer nuclear layer. No differences were observed in the other retinal layers. Our study suggests that the retinal circadian clock is an important modulator of photoreceptor health.
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Affiliation(s)
- Kenkichi Baba
- Department of Pharmacology and Toxicology Morehouse School of Medicine, Neuroscience Institute, Atlanta, GA, USA.
| | - Christophe P Ribelayga
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - P Michael Iuvone
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Gianluca Tosini
- Department of Pharmacology and Toxicology Morehouse School of Medicine, Neuroscience Institute, Atlanta, GA, USA
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Pardue M, Chakraborty R, Landis E, Park H, Stone RA, Iuvone PM. Photoreceptor pathways differentially contribute to refractive eye growth in mice. J Vis 2017. [DOI: 10.1167/17.15.34a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Machelle Pardue
- Wallace H. Coulter, Department of Biomedical Engineering, Georgia Institute of Technology
- Rehab R&D Center of Excellence, Atlanta VA Medical Center
| | - Ranjay Chakraborty
- Rehab R&D Center of Excellence, Atlanta VA Medical Center
- Ophthalmology, Emory University School of Medicine
| | - Erica Landis
- Rehab R&D Center of Excellence, Atlanta VA Medical Center
- Ophthalmology, Emory University School of Medicine
| | - Hanna Park
- Rehab R&D Center of Excellence, Atlanta VA Medical Center
- Ophthalmology, Emory University School of Medicine
| | | | - P. Michael Iuvone
- Ophthalmology, Emory University School of Medicine
- Pharmacology, Emory University School of Medicine
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Haque R, Iuvone PM, He L, Hur EH, Chung Choi KS, Park D, Farrell AN, Ngo A, Gokhale S, Aseem M, Kumar B. Prorenin receptor (PRR)-mediated NADPH oxidase (Nox) signaling regulates VEGF synthesis under hyperglycemic condition in ARPE-19 cells. J Recept Signal Transduct Res 2017; 37:560-568. [PMID: 28840773 DOI: 10.1080/10799893.2017.1369120] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The stimulation of angiotensin II (Ang II), the effector peptide of renin-angiotensin system, has been reported to increase the expression of vascular endothelial growth factor (VEGF) through the activation of the Ang II type 1 receptor (AT1R). In this study, we investigated whether hyperglycemia (HG, 33 mM glucose) in ARPE-19 cells could promote the expression of VEGF independently of Ang II through prorenin receptor (PRR), via an NADPH oxidase (Nox)-dependent mechanism. ARPE-19 cells were treated with the angiotensin converting enzyme (ACE) inhibitor perindopril to block the synthesis of Ang II. Treatment with HG induced VEGF expression in ARPE-19 cells, which was attenuated by pretreatment with the inhibitors of Nox, but not those of nitric oxide synthase, xanthine oxidase and mitochondrial O2 synthesis. In addition, Nox-derived [Formula: see text] and H2O2 signaling in the regulation of VEGF was determined by using both polyethylene glycol (PEG)-catalase (CAT) and PEG-superoxide dismutase (SOD). We demonstrated that small interfering RNA (siRNA)-mediated knockdown of PRR, Nox2 and Nox4 significantly reduced the HG-induced stimulation of VEGF. On the other hand, Nox4 overexpression significantly potentiated PRR-induced stimulation of VEGF under hyperglycemia in ARPE-19 cells. Furthermore, Nox4 was shown to be associated with enhanced activities of ERK1/2 and NF-κB (p65), indicating their involvement in PRR-induced activation of VEGF under HG in ARPE-19 cells. Our results support the hypothesis that Nox4-derived reactive oxygen species (ROS) signaling is implicated in the hyperglycemia-induced increase of VEGF expression through PRR in ARPE-19 cells. However, further work is needed to evaluate the role of PRR and Nox-s in HG-induced stimulation of VEGF in vivo.
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Affiliation(s)
- Rashidul Haque
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - P Michael Iuvone
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Li He
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Elizabeth H Hur
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Kimberly Su Chung Choi
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Daniel Park
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Annie N Farrell
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Ashley Ngo
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Samantha Gokhale
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Madiha Aseem
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
| | - Bhavna Kumar
- a Department of Ophthalmology , Emory University School of Medicine , Atlanta , GA , USA
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Struebing FL, King R, Li Y, Chrenek MA, Lyuboslavsky PN, Sidhu CS, Iuvone PM, Geisert EE. Transcriptional Changes in the Mouse Retina after Ocular Blast Injury: A Role for the Immune System. J Neurotrauma 2017; 35:118-129. [PMID: 28599600 DOI: 10.1089/neu.2017.5104] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ocular blast injury is a major medical concern for soldiers and explosion victims due to poor visual outcomes. To define the changes in gene expression following a blast injury to the eye, we examined retinal ribonucleic acid (RNA) expression in 54 mouse strains 5 days after a single 50-psi overpressure air wave blast injury. We observe that almost 40% of genes are differentially expressed with a false discovery rate (FDR) of <0.001, even though the nominal changes in RNA expression are rather small. Moreover, we find through machine learning approaches that genetic networks related to the innate and acquired immune system are activated. Accompanied by lymphocyte invasion into the inner retina, blast injury also results in progressive loss of visual function and retinal ganglion cells (RGCs). Collectively, these data demonstrate how systems genetics can be used to put meaning to the transcriptome changes following ocular blast injury that eventually lead to blindness.
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Affiliation(s)
| | - Rebecca King
- Department of Ophthalmology, Emory University , Atlanta, Georgia
| | - Ying Li
- Department of Ophthalmology, Emory University , Atlanta, Georgia
| | - Micah A Chrenek
- Department of Ophthalmology, Emory University , Atlanta, Georgia
| | | | - Curran S Sidhu
- Department of Ophthalmology, Emory University , Atlanta, Georgia
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University , Atlanta, Georgia
| | - Eldon E Geisert
- Department of Ophthalmology, Emory University , Atlanta, Georgia
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30
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Zhang Z, Kang SS, Liu X, Ahn EH, Zhang Z, He L, Iuvone PM, Duong DM, Seyfried NT, Benskey MJ, Manfredsson FP, Jin L, Sun YE, Wang JZ, Ye K. Asparagine endopeptidase cleaves α-synuclein and mediates pathologic activities in Parkinson's disease. Nat Struct Mol Biol 2017; 24:632-642. [PMID: 28671665 DOI: 10.1038/nsmb.3433] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 06/14/2017] [Indexed: 12/12/2022]
Abstract
Aggregated forms of α-synuclein play a crucial role in the pathogenesis of synucleinopathies such as Parkinson's disease (PD). However, the molecular mechanisms underlying the pathogenic effects of α-synuclein are not completely understood. Here we show that asparagine endopeptidase (AEP) cleaves human α-synuclein, triggers its aggregation and escalates its neurotoxicity, thus leading to dopaminergic neuronal loss and motor impairments in a mouse model. AEP is activated and cleaves human α-synuclein at N103 in an age-dependent manner. AEP is highly activated in human brains with PD, and it fragments α-synuclein, which is found aggregated in Lewy bodies. Overexpression of the AEP-cleaved α-synuclein1-103 fragment in the substantia nigra induces both dopaminergic neuronal loss and movement defects in mice. In contrast, inhibition of AEP-mediated cleavage of α-synuclein (wild type and A53T mutant) diminishes α-synuclein's pathologic effects. Together, these findings support AEP's role as a key mediator of α-synuclein-related etiopathological effects in PD.
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Affiliation(s)
- Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China.,Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Seong Su Kang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Xia Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Eun Hee Ahn
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Li He
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA.,Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, USA.,Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Matthew J Benskey
- Translational Science and Molecular Medicine, Michigan State University, College of Human Medicine, and Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
| | - Fredric P Manfredsson
- Translational Science and Molecular Medicine, Michigan State University, College of Human Medicine, and Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, Michigan, USA
| | - Lingjing Jin
- Translational Center for Stem Cell Research, Tongji Hospital, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Yi E Sun
- Translational Center for Stem Cell Research, Tongji Hospital, Department of Regenerative Medicine, Tongji University School of Medicine, Shanghai, China
| | - Jian-Zhi Wang
- Pathophysiology Department, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of the Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
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Zhou X, Pardue MT, Iuvone PM, Qu J. Dopamine signaling and myopia development: What are the key challenges. Prog Retin Eye Res 2017; 61:60-71. [PMID: 28602573 DOI: 10.1016/j.preteyeres.2017.06.003] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 05/23/2017] [Accepted: 06/05/2017] [Indexed: 01/11/2023]
Abstract
In the face of an "epidemic" increase in myopia over the last decades and myopia prevalence predicted to reach 2.5 billion people by the end of this decade, there is an urgent need to develop effective and safe therapeutic interventions to slow down this "myopia booming" and prevent myopia-related complications and vision loss. Dopamine (DA) is an important neurotransmitter in the retina and mediates diverse functions including retina development, visual signaling, and refractive development. Inspired by the convergence of epidemiological and animal studies in support of the inverse relationship between outdoor activity and risk of developing myopia and by the close biological relationship between light exposure and dopamine release/signaling, we felt it is timely and important to critically review the role of DA in myopia development. This review will revisit several key points of evidence for and against DA mediating light control of myopia: 1) the causal role of extracellular retinal DA levels, 2) the mechanism and action of dopamine D1 and D2 receptors and 3) the roles of cellular/circuit retinal pathways. We examine the experiments that show causation by altering DA, DA receptors and visual pathways using pharmacological, transgenic, or visual environment approaches. Furthermore, we critically evaluate the safety issues of a DA-based treatment strategy and some approaches to address these issues. The review identifies the key questions and challenges in translating basic knowledge on DA signaling and myopia from animal studies into effective pharmacological treatments for myopia in children.
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Affiliation(s)
- Xiangtian Zhou
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, China; State Key Laboratory of Ophthalmology, Optometry and Vision Science. 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, China
| | - Machelle T Pardue
- Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr, Atlanta, GA 30332, United States; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 1670 Clairmont Rd, Decatur, GA 30033, United States
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA 30322, United States; Department of Pharmacology, Emory University School of Medicine, 1365B Clifton Rd NE, Atlanta, GA 30322, United States
| | - Jia Qu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang 325003, China; State Key Laboratory of Ophthalmology, Optometry and Vision Science. 270 Xueyuan Road, Wenzhou, Zhejiang, 325003, China.
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32
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Stone RA, Cohen Y, McGlinn AM, Davison S, Casavant S, Shaffer J, Khurana TS, Pardue MT, Iuvone PM. Development of Experimental Myopia in Chicks in a Natural Environment. Invest Ophthalmol Vis Sci 2017; 57:4779-89. [PMID: 27618415 PMCID: PMC5024671 DOI: 10.1167/iovs.16-19310] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Purpose The hypothesis that outdoor exposure might protect against myopia has generated much interest, although available data find only modest clinical efficacy. We tested the effect of outdoor rearing on form-deprivation myopia in chicks, a myopia model markedly inhibited by high-intensity indoor laboratory lighting. Methods Unilaterally goggled cohorts of White Leghorn chicks were maintained in a species-appropriate, outdoor rural setting during daylight hours to the extent permitted by weather. Control chicks were reared indoors with incandescent lighting. Besides ocular refraction and ultrasound, we determined dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) content in retina and vitreous and measured mRNA expression levels of selected clock and circadian rhythm-related genes in the retina/RPE. Results Myopia developed in the goggled eyes of all cohorts. Whereas outdoor rearing lessened myopia by 44% at 4 days, a protective effect was no longer evident at 11 days. Outdoor rearing had no consistent effect on retinal or vitreous content of dopamine or DOPAC. Conforming to prior data on form-deprivation myopia, retina and vitreous levels of DOPAC were reduced in goggled eyes. Compared with contralateral eyes, the retinal expression of clock and circadian rhythm-related genes was modestly altered in myopic eyes of chicks reared indoors or outdoors. Conclusions Outdoor rearing of chicks induces only a partial decrease of goggle-induced myopia that is not maintained, without evidence that retinal dopamine metabolism accounts for the partial myopia inhibition under these outdoor conditions. Although modest, alterations in retinal gene expression suggest that studying circadian signals might be informative for understanding refractive mechanisms.
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Affiliation(s)
- Richard A Stone
- Department of Ophthalmology University of Pennsylvania School of Medicine, Scheie Eye Institute, Philadelphia, Pennsylvania, United States
| | - Yuval Cohen
- Department of Ophthalmology University of Pennsylvania School of Medicine, Scheie Eye Institute, Philadelphia, Pennsylvania, United States
| | - Alice M McGlinn
- Department of Ophthalmology University of Pennsylvania School of Medicine, Scheie Eye Institute, Philadelphia, Pennsylvania, United States
| | - Sherrill Davison
- Laboratory of Avian Medicine and Pathology, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, Kennett Square, Pennsylvania, United States
| | - Susan Casavant
- Laboratory of Avian Medicine and Pathology, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, Kennett Square, Pennsylvania, United States
| | - James Shaffer
- Department of Ophthalmology University of Pennsylvania School of Medicine, Scheie Eye Institute, Philadelphia, Pennsylvania, United States
| | - Tejvir S Khurana
- Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
| | - Machelle T Pardue
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States 5Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia, United States
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States 7Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
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Bergen MA, Park HN, Chakraborty R, Landis EG, Sidhu C, He L, Iuvone PM, Pardue MT. Altered Refractive Development in Mice With Reduced Levels of Retinal Dopamine. Invest Ophthalmol Vis Sci 2017; 57:4412-4419. [PMID: 27750284 PMCID: PMC5015967 DOI: 10.1167/iovs.15-17784] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose The neuromodulator dopamine (DA) has been implicated in the prevention of excessive ocular elongation and myopia in various animal models. This study used retina-specific DA knockout mice to investigate the role of retinal DA in refractive development and susceptibility to experimental myopia. Methods Measurements of refractive error, corneal curvature, and ocular biometrics were obtained as a function of age for both untreated and form-deprived (FD) groups of retina-specific tyrosine hydroxylase knockout (rTHKO) and control (Ctrl) mice. Retinas from each group were analyzed by HPLC for levels of DA and its primary metabolite (DOPAC). Results Under normal visual conditions, rTHKO mice showed significantly myopic refractions (F(1,188) = 7.602, P < 0.001) and steeper corneas (main effect of genotype F(1,180) = 5.1, P < 0.01) at 4 and 6 weeks of age compared with Ctrl mice. Retina-specific THKO mice also had thinner corneas (main effect of genotype F(1,181) = 37.17, P < 0.001), thinner retinas (F(6,181) = 6.07, P < 0.001), and shorter axial lengths (F(6,181) = 3.78, P < 0.01) than Ctrl mice. Retina-specific THKO retinas contained less than 15% of DA and DOPAC compared with Ctrl retinas, and the remaining DA had a significantly higher turnover, as indicated by DOPAC/DA ratios (Student's t-test, P < 0.05). Retina-specific THKO mice showed similar, yet more variable, responses to 6 weeks of FD compared with Ctrl mice. Conclusions Diminished retinal DA induced spontaneous myopia in mice raised under laboratory conditions without form deprivation. The relative myopic shift in rTHKO mice may be explained by steeper corneas, an unexpected finding. The chronic loss of DA did not significantly alter the FD myopia response in rTHKO mice.
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Affiliation(s)
- Michael A Bergen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia, United States 2Biology, Emory University, Atlanta, Georgia, United States
| | - Han Na Park
- Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Ranjay Chakraborty
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia, United States 3Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Erica G Landis
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia, United States 4Neuroscience, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Curran Sidhu
- Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Li He
- Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - P Michael Iuvone
- Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States 4Neuroscience, Emory University School of Medicine, Atlanta, Georgia, United States 5Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia, United States 3Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States 4Neuroscience, Emory University School of Medicine, Atlanta, Georgia, United States
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Haque R, Iuvone PM, He L, Choi KSC, Ngo A, Gokhale S, Aseem M, Park D. The MicroRNA-21 signaling pathway is involved in prorenin receptor (PRR) -induced VEGF expression in ARPE-19 cells under a hyperglycemic condition. Mol Vis 2017; 23:251-262. [PMID: 28465657 PMCID: PMC5398881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 04/12/2017] [Indexed: 11/25/2022] Open
Abstract
PURPOSE MicroRNAs (miRNAs/miRs) are involved in a large number of biological functions and diseases, such as cancer, cardiovascular diseases, and diabetes. MiR-21 has been reported to target Sprouty homolog 1 (SPRY1), SMAD7, and PTEN. In this study, we examined the underlying role of miR-21 in the regulation of prorenin receptor (PRR)-mediated induction of vascular endothelial growth factor (VEGF) expression via targeting SMAD7, SPRY1, and PTEN in a hyperglycemic condition. METHODS PRR-mediated induction of VEGF under a hyperglycemic condition (high glucose, 33mM) was studied by treating ARPE-19 cells with perindopril (10 µmol/l), which inhibits angiotensin II-mediated signaling. ARPE-19 cells exposed to normal glucose (NG, 5.5 mM) were considered as the control. To examine the role of miR-21 in the regulation of SPRY1, SMAD7, PTEN, and VEGF, ARPE-19 cells cultured in NG or high glucose were transfected with scramble negative control (Scr), a miR-21 mimic, or a miR-21 antagomir. To investigate the role of PRR and the small GTP-binding protein RAC1 in the regulation of miR-21, the expression of PRR and RAC1 was silenced by transfecting ARPE-19 cells with their corresponding siRNAs. RESULTS Compared with the NG control, high glucose significantly induced the expression of PRR, VEGF, VEGFR2, and miR-21 but significantly suppressed the expression of SPRY1, SMAD7, and PTEN at the transcript and protein levels. In contrast, silencing the expression of PRR significantly abolished the high glucose-induced expression of VEGF, VEGFR2, and miR-21. Knockdown of RAC1 significantly attenuated the high glucose-induced expression of LOX, CTGF, and miR-21, suggesting that PRR and RAC1 are involved in the CTGF/LOX-mediated regulation of miR-21. Furthermore, high glucose dramatically increased the levels of pERK (p44), hypoxia-inducible factor (HIF-1α), and VEGF. However, this effect was antagonized by the miR-21 antagomir, indicative of the involvement of high glucose-induced miR-21 in the regulation of VEGF through ERK signaling. CONCLUSIONS Our findings, for the first time, showed that the pleiotropic action of miR-21 induced the expression of pERK, HIF-1α, and VEGF in the high glucose condition by simultaneously targeting SPRY1, SMAD7, and PTEN in ARPE-19 cells. Therefore, miR-21 may serve as a potential therapeutic target for diabetes-induced retinal pathology.
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Markand S, Baskin NL, Chakraborty R, Landis E, Wetzstein SA, Donaldson KJ, Priyadarshani P, Alderson SE, Sidhu CS, Boatright JH, Iuvone PM, Pardue MT, Nickerson JM. IRBP deficiency permits precocious ocular development and myopia. Mol Vis 2016; 22:1291-1308. [PMID: 27829784 PMCID: PMC5082647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/25/2016] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Interphotoreceptor retinoid-binding protein (IRBP) is abundant in the subretinal space and binds retinoids and lipophilic molecules. The expression of IRBP begins precociously early in mouse eye development. IRBP-deficient (KO) mice show less cell death in the inner retinal layers of the retina before eyelid opening compared to wild-type C57BL/6J (WT) controls and eventually develop profound myopia. Thus, IRBP may play a role in eye development before visually-driven phenomena. We report comparative observations during the course of the natural development of eyes in WT and congenic IRBP KO mice that suggest IRBP is necessary at the early stages of mouse eye development for correct function and development to exist in later stages. METHODS We observed the natural development of congenic WT and IRBP KO mice, monitoring several markers of eye size and development, including haze and clarity of optical components in the eye, eye size, axial length, immunohistological markers of differentiation and eye development, visually guided behavior, and levels of a putative eye growth stop signal, dopamine. We conducted these measurements at several ages. Slit-lamp examinations were conducted at post-natal day (P)21. Fundus and spectral domain optical coherence tomography (SD-OCT) images were compared at P15, P30, P45, and P80. Enucleated eyes from P5 to P10 were measured for weight, and ocular dimensions were measured with a noncontact light-emitting diode (LED) micrometer. We counted the cells that expressed tyrosine hydroxylase (TH-positive cells) at P23-P36 using immunohistochemistry on retinal flatmounts. High-performance liquid chromatography (HPLC) was used to analyze the amounts of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) at P7-P60. Monocular form deprivation in the right eye was induced using head-mounted goggles from P28 to P56. RESULTS Eye elongation and eye size in the IRBP KO mice began to increase at P7 compared to the WT mice. This difference increased until P12, and the difference was maintained thereafter. SD-OCT images in live mice confirmed previously reported retinal thinning of the outer nuclear layer in the IRBP KO mice compared to the WT mice from P15 to P80. Slit-lamp and fundoscopy examination outcomes did not differ between the WT and KO mice. SD-OCT measurements of the optical axis components showed that the only factor contributing to excess optical axis length was the depth of the vitreous body. No other component of optical axis length (including corneal thickness, anterior chamber depth, and lens thickness) was different from that of the WT mouse. The refractive power of the IRBP KO mice did not change in response to form deprivation. The number of retinal TH-positive cells was 28% greater in the IRBP KO retinas compared to the WT mice at P30. No significant differences were observed in the steady-state retinal DA or DOPAC levels or in the DOPAC/DA ratios between the WT and IRBP KO mice. CONCLUSIONS The IRBP KO mouse eye underwent precocious development and rapid eye size growth temporally about a day sooner than the WT mouse eye. Eye size began to differ between the WT and KO mice before eyelid opening, indicating no requirement for focus-dependent vision, and suggesting a developmental abnormality in the IRBP KO mouse eye that precedes form vision-dependent emmetropization. Additionally, the profoundly myopic KO eye did not respond to form deprivation compared to the non-deprived contralateral eye. Too much growth occurred in some parts of the eye, possibly upsetting a balance among size, differentiation, and focus-dependent growth suppression. Thus, the loss of IRBP may simply cause growth that is too rapid, possibly due to a lack of sequestration or buffering of morphogens that normally would bind to IRBP but are unbound in the IRBP KO eye. Despite the development of profound myopia, the DA levels in the IRBP KO mice were not statistically different from those in the WT mice, even with the excess of TH-positive cells in the IRBP KO mice compared to the WT mice. Overall, these data suggest that abnormal eye elongation in the IRBP KO mouse is independent of, precedes, and is epistatic to the process(es) of visually-driven refractive development.
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Affiliation(s)
- Shanu Markand
- Department of Ophthalmology, Emory University, Atlanta, GA
| | | | - Ranjay Chakraborty
- Department of Ophthalmology, Emory University, Atlanta, GA,Atlanta Veterans Administration Center of Visual and Neurocognitive Rehabilitation, Decatur, GA
| | - Erica Landis
- Atlanta Veterans Administration Center of Visual and Neurocognitive Rehabilitation, Decatur, GA,Neuroscience Program, Laney Graduate School, Emory University, Atlanta, GA
| | | | | | | | | | | | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University, Atlanta, GA,Atlanta Veterans Administration Center of Visual and Neurocognitive Rehabilitation, Decatur, GA
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA,Department of Pharmacology, Emory University, Atlanta, GA
| | - Machelle T. Pardue
- Department of Ophthalmology, Emory University, Atlanta, GA,Atlanta Veterans Administration Center of Visual and Neurocognitive Rehabilitation, Decatur, GA,Neuroscience Program, Laney Graduate School, Emory University, Atlanta, GA,Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA
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Vancura P, Wolloscheck T, Baba K, Tosini G, Iuvone PM, Spessert R. Circadian and Dopaminergic Regulation of Fatty Acid Oxidation Pathway Genes in Retina and Photoreceptor Cells. PLoS One 2016; 11:e0164665. [PMID: 27727308 PMCID: PMC5058478 DOI: 10.1371/journal.pone.0164665] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/28/2016] [Indexed: 12/17/2022] Open
Abstract
The energy metabolism of the retina might comply with daily changes in energy demand and is impaired in diabetic retinopathy-one of the most common causes of blindness in Europe and the USA. The aim of this study was to investigate putative adaptation of energy metabolism in healthy and diabetic retina. Hence expression analysis of metabolic pathway genes was performed using quantitative polymerase chain reaction, semi-quantitative western blot and immunohistochemistry. Transcriptional profiling of key enzymes of energy metabolism identified transcripts of mitochondrial fatty acid β-oxidation enzymes, i.e. carnitine palmitoyltransferase-1α (Cpt-1α) and medium chain acyl-CoA dehydrogenase (Acadm) to display daily rhythms with peak values during daytime in preparations of the whole retina and microdissected photoreceptors. The cycling of both enzymes persisted in constant darkness, was dampened in mice deficient for dopamine D4 (D4) receptors and was altered in db/db mice-a model of diabetic retinopathy. The data of the present study are consistent with circadian clock-dependent and dopaminergic regulation of fatty acid oxidation in retina and its putative disturbance in diabetic retina.
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MESH Headings
- Acyl-CoA Dehydrogenase/genetics
- Acyl-CoA Dehydrogenase/metabolism
- Animals
- Carnitine O-Palmitoyltransferase/genetics
- Carnitine O-Palmitoyltransferase/metabolism
- Circadian Rhythm/physiology
- Diabetic Retinopathy/metabolism
- Diabetic Retinopathy/pathology
- Disease Models, Animal
- Dopamine/metabolism
- Energy Metabolism
- Fatty Acids/chemistry
- Fatty Acids/metabolism
- Female
- Male
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Obese
- Microscopy, Fluorescence
- Oxidation-Reduction
- Photoreceptor Cells/metabolism
- Receptor, Melatonin, MT1/deficiency
- Receptor, Melatonin, MT1/genetics
- Receptors, Dopamine D4/deficiency
- Receptors, Dopamine D4/genetics
- Retina/metabolism
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Affiliation(s)
- Patrick Vancura
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Tanja Wolloscheck
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Kenkichi Baba
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States of America
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Rainer Spessert
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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Iuvone PM. Is Retinal Dopamine Involved in the Loss of Visual Function in Retinopathy of Prematurity? Invest Ophthalmol Vis Sci 2016; 57:3380. [DOI: 10.1167/iovs.16-20073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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38
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Kunst S, Wolloscheck T, Kelleher DK, Wolfrum U, Sargsyan SA, Iuvone PM, Baba K, Tosini G, Spessert R. Pgc-1α and Nr4a1 Are Target Genes of Circadian Melatonin and Dopamine Release in Murine Retina. Invest Ophthalmol Vis Sci 2016; 56:6084-94. [PMID: 26393668 DOI: 10.1167/iovs.15-17503] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
PURPOSE The neurohormones melatonin and dopamine mediate clock-dependent/circadian regulation of inner retinal neurons and photoreceptor cells and in this way promote their functional adaptation to time of day and their survival. To fulfill this function they act on melatonin receptor type 1 (MT1 receptors) and dopamine D4 receptors (D4 receptors), respectively. The aim of the present study was to screen transcriptional regulators important for retinal physiology and/or pathology (Dbp, Egr-1, Fos, Nr1d1, Nr2e3, Nr4a1, Pgc-1α, Rorβ) for circadian regulation and dependence on melatonin signaling/MT1 receptors or dopamine signaling/D4 receptors. METHODS This was done by gene profiling using quantitative polymerase chain reaction in mice deficient in MT1 or D4 receptors. RESULTS The data obtained determined Pgc-1α and Nr4a1 as transcriptional targets of circadian melatonin and dopamine signaling, respectively. CONCLUSIONS The results suggest that Pgc-1α and Nr4a1 represent candidate genes for linking circadian neurohormone release with functional adaptation and healthiness of retina and photoreceptor cells.
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Affiliation(s)
- Stefanie Kunst
- Institute of Functional and Clinical Anatomy University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany 2Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University, Mainz, Germany
| | - Tanja Wolloscheck
- Institute of Functional and Clinical Anatomy University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Debra K Kelleher
- Institute of Functional and Clinical Anatomy University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University, Mainz, Germany
| | - S Anna Sargsyan
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - P Michael Iuvone
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Kenkichi Baba
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States
| | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, Georgia, United States
| | - Rainer Spessert
- Institute of Functional and Clinical Anatomy University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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Iuvone PM, Haque R, Fernandes A, Lambert SR. Neonatal aphakia is associated with altered levels of dopamine metabolites in the non-human primate retina. Exp Eye Res 2015; 140:187-189. [PMID: 26368851 DOI: 10.1016/j.exer.2015.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 08/28/2015] [Accepted: 09/08/2015] [Indexed: 11/24/2022]
Abstract
Neonatal aphakia is associated with retardation of the axial elongation of the neonatal eye. In contrast, form deprivation increases axial elongation, an effect that has been associated with decreased retinal dopamine metabolism. The present investigation was conducted to test the hypothesis that neonatal aphakia induces an effect on the levels of retinal dopamine opposite to form deprivation. Lensectomy and vitrectomy were performed on the right eyes of rhesus monkeys at approximately 1 week of age; their left eyes were unmanipulated. Axial length was measured by A-scan ultrasonography. Prior to surgery, mean axial length of the right and left eyes was identical. Following lens removal, both eyes continued to elongate, however the aphakic eyes elongated at a slower rate resulting in a significant shorter axial length compared to that of the unmanipulated eye. Removal of the crystalline lens had no effect on steady-state dopamine levels in either central or peripheral retina. However, levels of the dopamine metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid were significantly elevated in central retina, but not in the peripheral retina of aphakic eyes. Our results support the hypothesis that dopamine is a component of the retinal signaling pathways that are involved in the regulation of eye growth and emmetropization.
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Affiliation(s)
- P Michael Iuvone
- Department of Ophthalamology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Rashidul Haque
- Department of Ophthalamology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Alcides Fernandes
- Department of Ophthalamology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Scott R Lambert
- Department of Ophthalamology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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40
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Chakraborty R, Park HN, Hanif AM, Sidhu CS, Iuvone PM, Pardue MT. ON pathway mutations increase susceptibility to form-deprivation myopia. Exp Eye Res 2015; 137:79-83. [PMID: 26072023 PMCID: PMC4523446 DOI: 10.1016/j.exer.2015.06.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 05/24/2015] [Accepted: 06/09/2015] [Indexed: 01/15/2023]
Abstract
The ON pathway mutation in nob mice is associated with altered refractive development, and an increased susceptibility to form-deprivation (FD) myopia. In this study, we used mGluR6-/- mice, another ON pathway mutant, to determine whether the nob phenotype was due to the Nyx mutation or abnormal ON pathway transmission. Refractive development under a normal visual environment for mGluR6-/- and age-matched wild-type (WT) mice was measured every 2 weeks from 4 to 16 weeks of age. The response to monocular FD from 4 weeks of age was measured weekly in a separate cohort of mice. Refraction and ocular biometry were obtained using a photorefractor and optical coherence tomography. Retinas were harvested at 16 weeks, and analyzed for dopamine (DA) and DOPAC using high-performance liquid chromatography. Under normal conditions, mGluR6-/- mice were significantly more myopic than their WT controls (refraction at 12 weeks; WT: 9.40 ± 0.16 D, mGluR6-/-: 6.91 ± 0.38 D). Similar to nob mice, two weeks of FD resulted in a significant myopic shift of -5.57 ± 0.72 D in mGluR6-/- mice compared to -1.66 ± 0.19 D in WT animals. No significant axial length changes were observed with either normal or FD visual conditions. At 16 weeks, mGluR6-/- retinas showed significantly lower DOPAC levels (111.2 ± 33.0 pg/mg) compared to their WT counterparts (197.5 ± 11.2 pg/mg). Retinal DA levels were similar between the different genotypes. Our results indicate that reduced retinal DA metabolism/turnover may be associated with increased susceptibility to myopia in mice with ON pathway defect mutations.
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Affiliation(s)
- Ranjay Chakraborty
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, USA
| | - Han Na Park
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, USA
| | - Adam M Hanif
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, USA
| | - Curran S Sidhu
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Machelle T Pardue
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, GA, USA.
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41
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Gokhale A, Vrailas-Mortimer A, Larimore J, Comstra HS, Zlatic SA, Werner E, Manvich DF, Iuvone PM, Weinshenker D, Faundez V. Neuronal copper homeostasis susceptibility by genetic defects in dysbindin, a schizophrenia susceptibility factor. Hum Mol Genet 2015. [PMID: 26199316 DOI: 10.1093/hmg/ddv282] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Environmental factors and susceptible genomes interact to determine the risk of neurodevelopmental disorders. Although few genes and environmental factors have been linked, the intervening cellular and molecular mechanisms connecting a disorder susceptibility gene with environmental factors remain mostly unexplored. Here we focus on the schizophrenia susceptibility gene DTNBP1 and its product dysbindin, a subunit of the BLOC-1 complex, and describe a neuronal pathway modulating copper metabolism via ATP7A. Mutations in ATP7A result in Menkes disease, a disorder of copper metabolism. Dysbindin/BLOC-1 and ATP7A genetically and biochemically interact. Furthermore, disruption of this pathway causes alteration in the transcriptional profile of copper-regulatory and dependent factors in the hippocampus of dysbindin/BLOC-1-null mice. Dysbindin/BLOC-1 loss-of-function alleles do not affect cell and tissue copper content, yet they alter the susceptibility to toxic copper challenges in both mammalian cells and Drosophila. Our results demonstrate that perturbations downstream of the schizophrenia susceptibility gene DTNBP1 confer susceptibility to copper, a metal that in excess is a neurotoxin and whose depletion constitutes a micronutrient deficiency.
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Affiliation(s)
- Avanti Gokhale
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA
| | | | | | - Heather S Comstra
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA
| | | | - Erica Werner
- Department of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Daniel F Manvich
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University, Atlanta, GA 30322, USA
| | - Victor Faundez
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA, Center for Social Translational Neuroscience, Emory University, Atlanta, GA 30322, USA,
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Setterholm NA, McDonald FE, Boatright JH, Iuvone PM. Gram-scale, chemoselective synthesis of N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC). Tetrahedron Lett 2015; 56:3413-3415. [PMID: 26028783 DOI: 10.1016/j.tetlet.2015.01.167] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC) is a potent activator of the TrkB receptor in mammalian neurons and of interest because of its potential therapeutic uses. In the absence of a commercial supply of HIOC, we sought to produce several grams of material. However, a synthesis of HIOC has never been published. Herein we report the preparation of HIOC by the chemoselective N-acylation of serotonin, without using blocking groups in the key acylation step.
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Affiliation(s)
- Noah A Setterholm
- Department of Chemistry, Emory University, 1515 Dickey Drive NE, Atlanta, GA 30322 USA
| | - Frank E McDonald
- Department of Chemistry, Emory University, 1515 Dickey Drive NE, Atlanta, GA 30322 USA
| | - Jeffrey H Boatright
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Road NE, Atlanta, GA 30322 USA ; Rehabilitation R & D Center, Atlanta VA Medical Center, Decatur, GA USA 30033 USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, 1365B Clifton Road NE, Atlanta, GA 30322 USA ; Department of Pharmacology, Emory University School of Medicine, 1510 Clifton Road NE, Atlanta, GA 30322 USA
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Haque R, Hur EH, Farrell AN, Iuvone PM, Howell JC. MicroRNA-152 represses VEGF and TGFβ1 expressions through post-transcriptional inhibition of (Pro)renin receptor in human retinal endothelial cells. Mol Vis 2015; 21:224-35. [PMID: 25802486 PMCID: PMC4358229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 03/05/2015] [Indexed: 11/01/2022] Open
Abstract
PURPOSE The (pro)renin receptor (PRR), a component of the renin-angiotensin system (RAS), plays an important role in the physiologic and pathophysiological regulation of blood pressure and fluid/electrolyte homeostasis. The RAS including the PRR has been identified in retinal endothelial cells and other ocular tissues. In this study, the potential involvement of miRNAs in the posttranscriptional regulation of PRR was investigated in human retinal endothelial cells (hRECs) under high glucose (HG) conditions. METHODS miRNA-152 (miR-152) was identified in silico as a potential regulator of PRR, and this was confirmed by quantitative real-time PCR (qRT-PCR) and PRR 3'-untranslated region (UTR) reporter assays. Using RNA interference, both AT1R and PRR were implicated in the HG-mediated induction of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR-2), and transforming growth factor β1 (TGFβ1). RESULTS The downregulation of miR-152 was observed in hRECs and rat retinal tissues under HG conditions. In parallel, PRR (target of miR-152), VEGF, VEGFR-2, and TGFβ1 at mRNA levels were elevated. However, the transfection of hRECs with miR-152 mimics in HG conditions resulted in the suppression of the PRR expression, as well as reduced VEGF, VEGFR-2, and TGFβ1 production. This was reversed by transfecting cells with the antisense (antagomir) of miR-152, suggesting the glucose-induced upregulation of VEGF, VEGFR-2, and TGFβ1 is mediated through PRR, and this regulation is likely achieved through the HG-mediated modulation of miRNAs. CONCLUSIONS We have demonstrated that miR-152 interacting with PRR regulates downstream VEGF, VRGFR-2, and TGFβ1 expressions in hRECs in HG conditions. These studies suggest miR-152 and PRR may play a role in the pathogenesis of diabetic retinopathy (DR).
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Barathi VA, Chaurasia SS, Poidinger M, Koh SK, Tian D, Ho C, Iuvone PM, Beuerman RW, Zhou L. Involvement of GABA transporters in atropine-treated myopic retina as revealed by iTRAQ quantitative proteomics. J Proteome Res 2014; 13:4647-58. [PMID: 25211393 PMCID: PMC4227558 DOI: 10.1021/pr500558y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Atropine,
a muscarinic antagonist, is known to inhibit myopia progression
in several animal models and humans. However, the mode of action is
not established yet. In this study, we compared quantitative iTRAQ
proteomic analysis in the retinas collected from control and lens-induced
myopic (LIM) mouse eyes treated with atropine. The myopic group received
a (−15D) spectacle lens over the right eye on postnatal day
10 with or without atropine eye drops starting on postnatal day 24.
Axial length was measured by optical low coherence interferometry
(OLCI), AC-Master, and refraction was measured by automated infrared
photorefractor at postnatal 24, 38, and 52 days. Retinal tissue samples
were pooled from six eyes for each group. The experiments were repeated
twice, and technical replicates were also performed for liquid chromatography–tandem
mass spectrometry (LC–MS/MS) analysis. MetaCore was used to
perform protein profiling for pathway analysis. We identified a total
of 3882 unique proteins with <1% FDR by analyzing the samples in
replicates for two independent experiments. This is the largest number
of mouse retina proteome reported to date. Thirty proteins were found
to be up-regulated (ratio for myopia/control > global mean ratio
+
1 standard deviation), and 28 proteins were down-regulated (ratio
for myopia/control < global mean ratio - 1 standard deviation)
in myopic eyes as compared with control retinas. Pathway analysis
using MetaCore revealed regulation of γ-aminobutyric acid (GABA)
levels in the myopic eyes. Detailed analysis of the quantitative proteomics
data showed that the levels of GABA transporter 1 (GAT-1) were elevated
in myopic retina and significantly reduced after atropine treatment.
These results were further validated with immunohistochemistry and
Western blot analysis. In conclusion, this study provides a comprehensive
quantitative proteomic analysis of atropine-treated mouse retina and
suggests the involvement of GABAergic signaling in the antimyopic
effects of atropine in mouse eyes. The GABAergic transmission in the
neural retina plays a pivotal role in the maintenance of axial eye
growth in mammals.
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Affiliation(s)
- Veluchamy A Barathi
- Singapore Eye Research Institute , 11 Third Hospital Avenue, Singapore 168751, Singapore
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Chakraborty R, Park HN, Aung MH, Tan CC, Sidhu CS, Iuvone PM, Pardue MT. Comparison of refractive development and retinal dopamine in OFF pathway mutant and C57BL/6J wild-type mice. Mol Vis 2014; 20:1318-27. [PMID: 25352740 PMCID: PMC4169773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 09/18/2014] [Indexed: 11/03/2022] Open
Abstract
Purpose Proper visual transmission depends on the retinal ON and OFF pathways. We used Vsx1−/− mice with a retinal OFF visual pathway defect to determine the role of OFF pathway signaling in refractive development (RD) of the eye. Methods Refractive development was measured every 2 weeks in Vsx1−/−, Vsx1+/+ (both on 129S1/Sv background), and commonly used C57BL/6J mice from 4 to 12 weeks of age. Form deprivation (FD) was induced monocularly from 4 weeks of age using head-mounted diffuser goggles. Refractive state, corneal curvature, and ocular biometry were obtained weekly using photorefraction, keratometry, and 1310 nm spectral-domain optical coherence tomography. Retinal dopamine and its metabolite, 3,4-dihydroxyphenylacetate (DOPAC), were measured using high-performance liquid chromatography (HPLC). Results During normal development, the Vsx1−/− and Vsx1+/+ mice showed similar myopic refractions at younger ages (4 weeks, Vsx1−/−: −5.28±0.75 diopter (D); WT: −4.73±0.98 D) and became significantly hyperopic by 12 weeks of age (Vsx1−/−: 3.28±0.82 D; WT: 5.33±0.81 D). However, the C57BL/6J mice were relatively hyperopic at younger ages (mean refraction at 4 weeks, 3.40±0.43 D), and developed more hyperopic refractions until about 7 weeks of age (8.07±0.55 D) before stabilizing. Eight weeks of FD did not induce a myopic shift in the 129S1/Sv animals (0.16±0.85 D), as opposed to a significant shift of −4.29±0.42 D in the C57BL/6J mice. At 4 weeks of visual development, dopamine turnover (the DOPAC/dopamine ratio) was significantly greater in the 129S1/Sv mice compared to the C57BL/6J mice. FD did not alter the levels of dopamine between the goggled and opposite eyes for any genotype or strain. Conclusions OFF pathway signaling may not be critically important for normal refractive development in mice. Elevated retinal dopamine turnover in early refractive development may prevent FD myopia in 129S1/Sv mice compared to C57BL/6J mice.
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Affiliation(s)
- Ranjay Chakraborty
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Atlanta VA Center of Visual and Neurocognitive Rehabilitation, Decatur, GA
| | - Han na Park
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Atlanta VA Center of Visual and Neurocognitive Rehabilitation, Decatur, GA
| | - Moe H. Aung
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Department of Neuroscience, Emory University School of Medicine, Atlanta, GA
| | - Christopher C. Tan
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - Curran S. Sidhu
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Department of Neuroscience, Emory University School of Medicine, Atlanta, GA,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA
| | - Machelle T. Pardue
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Department of Neuroscience, Emory University School of Medicine, Atlanta, GA,Atlanta VA Center of Visual and Neurocognitive Rehabilitation, Decatur, GA
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Park HN, Jabbar SB, Tan CC, Sidhu CS, Abey J, Aseem F, Schmid G, Iuvone PM, Pardue MT. Visually-driven ocular growth in mice requires functional rod photoreceptors. Invest Ophthalmol Vis Sci 2014; 55:6272-9. [PMID: 25183765 DOI: 10.1167/iovs.14-14648] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Proper refractive eye growth depends on several features of the visual image and requisite retinal pathways. In this study, we determined the contribution of rod pathways to normal refractive development and form deprivation (FD) myopia by testing Gnat1(-/-) mice, which lack functional rods due to a mutation in rod transducin-α. METHODS Refractive development was measured in Gnat1(-/-) (n = 30-36) and wild-type (WT) mice (n = 5-9) from 4 to 12 weeks of age. FD was induced monocularly from 4 weeks of age using head-mounted diffuser goggles (Gnat1(-/-), n = 9-10; WT, n = 7-8). Refractive state and ocular biometry were obtained weekly using a photorefractor, 1310 nm optical coherence tomography, and partial coherence interferometry. We measured retinal dopamine and its metabolite, DOPAC, using HPLC. RESULTS During normal development, the refractions of WT mice started at 5.36 ± 0.68 diopters (D) and became more hyperopic before plateauing at 7.78 ± 0.64 D. In contrast, refractions in Gnat1(-/-) mice were stable at 7.39 ± 1.22 D across all ages. Three weeks of FD induced a 2.54 ± 0.77 D myopic shift in WT mice, while Gnat1(-/-) mice did not respond to FD at any age. Axial lengths of Gnat1(-/-) and WT mice increased with age, but differences between genotypes or with goggling did not reach statistical significance and fell within the precision of the instruments. The DOPAC levels were significantly lower in Gnat1(-/-) mice from 2 to 12 weeks of age with DOPAC/dopamine ratio peaking earlier in Gnat1(-/-) compared to WT mice. No differences in dopamine were seen in response to FD or between genotypes. CONCLUSIONS Functional rod photoreceptors are critical to normal refractive development and the response to FD in mice. Dopamine levels may not directly modulate the refractive state of the mouse eye, but tonic levels of dopamine during development may determine susceptibility to myopia.
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Affiliation(s)
- Han na Park
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Seema B Jabbar
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Christopher C Tan
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Curran S Sidhu
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Jane Abey
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Fazila Aseem
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Gregor Schmid
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Machelle T Pardue
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, United States Atlanta Veterans Administration Center of Visual and Neurocognitive Rehabilitation, Decatur, Georgia, United States
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Yamazaki F, Kim HH, Lau P, Hwang CK, Iuvone PM, Klein D, Clokie SJH. pY RNA1-s2: a highly retina-enriched small RNA that selectively binds to Matrin 3 (Matr3). PLoS One 2014; 9:e88217. [PMID: 24558381 PMCID: PMC3928194 DOI: 10.1371/journal.pone.0088217] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/03/2014] [Indexed: 12/22/2022] Open
Abstract
The purpose of this study was to expand our knowledge of small RNAs, which are known to function within protein complexes to modulate the transcriptional output of the cell. Here we describe two previously unrecognized, small RNAs, termed pY RNA1-s1 and pY RNA1-s2 (processed Y RNA1-stem −1 and −2), thereby expanding the list of known small RNAs. pY RNA1-s1 and pY RNA1-s2 were discovered by RNA sequencing and found to be 20-fold more abundant in the retina than in 14 other rat tissues. Retinal expression of pY RNAs is highly conserved, including expression in the human retina, and occurs in all retinal cell layers. Mass spectrometric analysis of pY RNA1-S2 binding proteins in retina indicates that pY RNA1-s2 selectively binds the nuclear matrix protein Matrin 3 (Matr3) and to a lesser degree to hnrpul1 (heterogeneous nuclear ribonucleoprotein U-like protein). In contrast, pY RNA1-s1 does not bind these proteins. Accordingly, the molecular mechanism of action of pY RNA1-s2 is likely be through an action involving Matr3; this 95 kDa protein has two RNA recognition motifs (RRMs) and is implicated in transcription and RNA-editing. The high affinity binding of pY RNA1-s2 to Matr3 is strongly dependent on the sequence of the RNA and both RRMs of Matr3. Related studies also indicate that elements outside of the RRM region contribute to binding specificity and that phosphorylation enhances pY RNA-s2/Matr3 binding. These observations are of significance because they reveal that a previously unrecognized small RNA, pY RNA1-s2, binds selectively to Matr3. Hypothetically, pY RNA1-S2 might act to modulate cellular function through this molecular mechanism. The retinal enrichment of pY RNA1-s2 provides reason to suspect that the pY RNA1-s2/Matr3 interaction could play a role in vision.
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Affiliation(s)
- Fumiyoshi Yamazaki
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hyun Hee Kim
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Pierre Lau
- Division of intramural research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christopher K. Hwang
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - P. Michael Iuvone
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - David Klein
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Samuel J. H. Clokie
- Section on Neuroendocrinology, Program in Developmental Endocrinology and Genetics, The Eunice Shriver Kennedy National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
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Zhang N, Favazza TL, Baglieri AM, Benador IY, Noonan ER, Fulton AB, Hansen RM, Iuvone PM, Akula JD. The rat with oxygen-induced retinopathy is myopic with low retinal dopamine. Invest Ophthalmol Vis Sci 2013; 54:8275-84. [PMID: 24168993 DOI: 10.1167/iovs.13-12544] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
PURPOSE Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. METHODS In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). RESULTS The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. CONCLUSIONS The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia.
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Affiliation(s)
- Nan Zhang
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts
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McMahon DG, Iuvone PM, Tosini G. Circadian organization of the mammalian retina: from gene regulation to physiology and diseases. Prog Retin Eye Res 2013; 39:58-76. [PMID: 24333669 DOI: 10.1016/j.preteyeres.2013.12.001] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/27/2013] [Accepted: 12/01/2013] [Indexed: 01/27/2023]
Abstract
The retinal circadian system represents a unique structure. It contains a complete circadian system and thus the retina represents an ideal model to study fundamental questions of how neural circadian systems are organized and what signaling pathways are used to maintain synchrony of the different structures in the system. In addition, several studies have shown that multiple sites within the retina are capable of generating circadian oscillations. The strength of circadian clock gene expression and the emphasis of rhythmic expression are divergent across vertebrate retinas, with photoreceptors as the primary locus of rhythm generation in amphibians, while in mammals clock activity is most robust in the inner nuclear layer. Melatonin and dopamine serve as signaling molecules to entrain circadian rhythms in the retina and also in other ocular structures. Recent studies have also suggested GABA as an important component of the system that regulates retinal circadian rhythms. These transmitter-driven influences on clock molecules apparently reinforce the autonomous transcription-translation cycling of clock genes. The molecular organization of the retinal clock is similar to what has been reported for the SCN although inter-neural communication among retinal neurons that form the circadian network is apparently weaker than those present in the SCN, and it is more sensitive to genetic disruption than the central brain clock. The melatonin-dopamine system is the signaling pathway that allows the retinal circadian clock to reconfigure retinal circuits to enhance light-adapted cone-mediated visual function during the day and dark-adapted rod-mediated visual signaling at night. Additionally, the retinal circadian clock also controls circadian rhythms in disk shedding and phagocytosis, and possibly intraocular pressure. Emerging experimental data also indicate that circadian clock is also implicated in the pathogenesis of eye disease and compelling experimental data indicate that dysfunction of the retinal circadian system negatively impacts the retina and possibly the cornea and the lens.
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Affiliation(s)
- Douglas G McMahon
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - P Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA; Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Gianluca Tosini
- Neuroscience Institute and Department of Pharmacology and Toxicology, Morehouse School of Medicine, Atlanta, 30310 GA, USA.
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50
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Park H, Tan CC, Faulkner A, Jabbar SB, Schmid G, Abey J, Iuvone PM, Pardue MT. Retinal degeneration increases susceptibility to myopia in mice. Mol Vis 2013; 19:2068-79. [PMID: 24146540 PMCID: PMC3786452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 09/26/2013] [Indexed: 10/25/2022] Open
Abstract
PURPOSE Retinal diseases are often associated with refractive errors, suggesting the importance of normal retinal signaling during emmetropization. For instance, retinitis pigmentosa, a disease characterized by severe photoreceptor degeneration, is associated with myopia; however, the underlying link between these conditions is not known. This study examines the influence of photoreceptor degeneration on refractive development by testing two mouse models of retinitis pigmentosa under normal and form deprivation visual conditions. Dopamine, a potential stop signal for refractive eye growth, was assessed as a potential underlying mechanism. METHODS Refractive eye growth in mice that were homozygous for a mutation in Pde6b, Pde6b(rd1/rd1) (rd1), or Pde6b(rd10/rd10) (rd10) was measured weekly from 4 to 12 weeks of age and compared to age-matched wild-type (WT) mice. Refractive error was measured using an eccentric infrared photorefractor, and axial length was measured with partial coherence interferometry or spectral domain ocular coherence tomography. A cohort of mice received head-mounted diffuser goggles to induce form deprivation from 4 to 6 weeks of age. Dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels were measured with high-performance liquid chromatography in each strain after exposure to normal or form deprivation conditions. RESULTS The rd1 and rd10 mice had significantly greater hyperopia relative to the WT controls throughout normal development; however, axial length became significantly longer only in WT mice starting at 7 weeks of age. After 2 weeks of form deprivation, the rd1 and rd10 mice demonstrated a faster and larger myopic shift (-6.14±0.62 and -7.38±1.46 diopter, respectively) compared to the WT mice (-2.41±0.47 diopter). Under normal visual conditions, the DOPAC levels and DOPAC/dopamine ratios, a measure of dopamine turnover, were significantly lower in the rd1 and rd10 mice compared to the WT mice, while the dopamine levels were similar or higher than WT in the rd10 mice. Lower basal levels of DOPAC were highly correlated with increasing myopic shifts. CONCLUSIONS Refractive development under normal visual conditions was disrupted toward greater hyperopia from 4 to 12 weeks of age in these photoreceptor degeneration models, despite significantly lower DOPAC levels. However, the retinal degeneration models with low basal levels of DOPAC had increased susceptibility to form deprivation myopia. These results indicate that photoreceptor degeneration may alter dopamine metabolism, leading to increased susceptibility to myopia with an environmental visual challenge.
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Affiliation(s)
- Hanna Park
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - Christopher C. Tan
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - Amanda Faulkner
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Rehab Center of Excellence, Atlanta VA Medical Center, Atlanta, GA
| | - Seema B. Jabbar
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - Gregor Schmid
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Rehab Center of Excellence, Atlanta VA Medical Center, Atlanta, GA
| | - Jane Abey
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA
| | - P. Michael Iuvone
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA
| | - Machelle T. Pardue
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA,Rehab Center of Excellence, Atlanta VA Medical Center, Atlanta, GA
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