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Grubaugh CR, Dhingra A, Prakash B, Montenegro D, Sparrow JR, Daniele LL, Curcio CA, Bell BA, Hussain MM, Boesze-Battaglia K. Microsomal triglyceride transfer protein is necessary to maintain lipid homeostasis and retinal function. FASEB J 2024; 38:e23522. [PMID: 38445789 PMCID: PMC10949407 DOI: 10.1096/fj.202302491r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024]
Abstract
Lipid processing by the retinal pigment epithelium (RPE) is necessary to maintain retinal health and function. Dysregulation of retinal lipid homeostasis due to normal aging or age-related disease triggers lipid accumulation within the RPE, on Bruch's membrane (BrM), and in the subretinal space. In its role as a hub for lipid trafficking into and out of the neural retina, the RPE packages a significant amount of lipid into lipid droplets for storage and into apolipoprotein B (APOB)-containing lipoproteins (Blps) for export. Microsomal triglyceride transfer protein (MTP), encoded by the MTTP gene, is essential for Blp assembly. Herein we test the hypothesis that MTP expression in the RPE is essential to maintain lipid balance and retinal function using the newly generated RPEΔMttp mouse model. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic depletion of Mttp from the RPE results in intracellular lipid accumulation, increased photoreceptor-associated cholesterol deposits, and photoreceptor cell death, and loss of rod but not cone function. RPE-specific reduction in Mttp had no significant effect on plasma lipids and lipoproteins. While APOB was decreased in the RPE, most ocular retinoids remained unchanged, with the exception of the storage form of retinoid, retinyl ester. Thus suggesting that RPE MTP is critical for Blp synthesis and assembly but is not directly involved in plasma lipoprotein metabolism. These studies demonstrate that RPE-specific MTP expression is necessary to establish and maintain retinal lipid homeostasis and visual function.
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Affiliation(s)
- Catharina R. Grubaugh
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Binu Prakash
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Diego Montenegro
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY, 10027 USA
| | - Janet R. Sparrow
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY, 10027 USA
| | - Lauren L. Daniele
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brent A. Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104 USA
| | - M. Mahmood Hussain
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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2
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Anderson BD, Lee TT, Bell BA, Wang T, Dunaief JL. Optimizing the sodium iodate model: Effects of dose, gender, and age. Exp Eye Res 2024; 239:109772. [PMID: 38158173 PMCID: PMC10922497 DOI: 10.1016/j.exer.2023.109772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/26/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Sodium iodate (NaIO3) is a commonly used model for age-related macular degeneration (AMD), but its rapid and severe induction of retinal pigment epithelial (RPE) and photoreceptor degeneration can lead to the premature dismissal of potentially effective therapeutics. Additionally, little is known about how sex and age affect the retinal response to NaIO3. This study aims to establish a less severe yet reproducible regimen by testing low doses of NaIO3 while considering age- and sex-related effects, enabling a broader range of therapeutic evaluations. In this study, young (3-5 months) and old (18-24 months) male and female C57Bl/6J mice were given an intraperitoneal (IP) injection of 15, 20, or 25 mg/kg NaIO3. Damage assessment one week post-injection included in vivo imaging, histological examination, and qRT-PCR analysis. The results revealed that young mice showed no damage at 15 mg/kg IP NaIO3, with varying degrees of damage observed at 20 mg/kg. At 25 mg/kg, most young mice displayed widespread retinal damage, with females exhibiting less retinal thinning than males. In contrast, older mice at 20 and 25 mg/kg displayed a more patchy degeneration pattern, outer retinal undulations, and greater variability in degeneration than the young mice. The most effective model for minimizing damage while maintaining consistency utilizes young female mice injected with 25 mg/kg NaIO3. The observed sex- and age-related differences underscore the importance of considering these variables in research, aligning with the National Institutes of Health's guidance. While the model does not fully replicate the complexity of AMD, these findings enhance its utility as a valuable tool for testing RPE/photoreceptor protective or replacement therapies.
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Affiliation(s)
- Brandon D Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Timothy T Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brent A Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Tan Wang
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA; Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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3
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Grubaugh CR, Dhingra A, Prakash B, Montenegro D, Sparrow JR, Daniele LL, Curcio CA, Bell BA, Hussain MM, Boesze-Battaglia K. Microsomal triglyceride transfer protein is necessary to maintain lipid homeostasis and retinal function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570418. [PMID: 38105975 PMCID: PMC10723417 DOI: 10.1101/2023.12.06.570418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Lipid processing by the retinal pigment epithelium (RPE) is necessary to maintain retinal health and function. Dysregulation of retinal lipid homeostasis due to normal aging or to age-related disease triggers lipid accumulation within the RPE, on Bruch's membrane (BrM), and in the subretinal space. In its role as a hub for lipid trafficking into and out of the neural retina, the RPE packages a significant amount of lipid into lipid droplets for storage and into apolipoprotein B (apoB)-containing lipoproteins (Blps) for export. Microsomal triglyceride transfer protein (MTP), encoded by the MTTP gene, is essential for Blp assembly. Herein we test the hypothesis that MTP expression in the RPE is essential to maintain lipid balance and retinal function using the newly generated RPEΔMttp mouse model. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic deletion of Mttp from the RPE results in intracellular lipid accumulation, increased photoreceptor -associated cholesterol deposits and photoreceptor cell death, and loss of rod but not cone function. RPE-specific ablation of Mttp had no significant effect on plasma lipids and lipoproteins. While, apoB was decreased in the RPE, ocular retinoid concentrations remained unchanged. Thus suggesting that RPE MTP is critical for Blp synthesis and assembly but not directly involved in ocular retinoid and plasma lipoprotein metabolism. These studies demonstrate that RPE-specific MTP expression is necessary to establish and maintain retinal lipid homeostasis and visual function.
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Affiliation(s)
- Catharina R. Grubaugh
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Binu Prakash
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Diego Montenegro
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY,10027 USA
| | - Janet R. Sparrow
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY,10027 USA
| | - Lauren L. Daniele
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brent A. Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104 USA
| | - M. Mahmood Hussain
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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4
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García-Llorca A, Ólafsson KH, Sigurdsson AT, Eysteinsson T. Progressive Cone-Rod Dystrophy and RPE Dysfunction in Mitfmi/+ Mice. Genes (Basel) 2023; 14:1458. [PMID: 37510362 PMCID: PMC10379086 DOI: 10.3390/genes14071458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/11/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
Mutations in the mouse microphthalmia-associated transcription factor (Mitf) gene affect retinal pigment epithelium (RPE) differentiation and development and can lead to hypopigmentation, microphthalmia, deafness, and blindness. For instance, an association has been established between loss-of-function mutations in the mouse Mitf gene and a variety of human retinal diseases, including Waardenburg type 2 and Tietz syndromes. Although there is evidence showing that mice with the homozygous Mitfmi mutation manifest microphthalmia and osteopetrosis, there are limited or no data on the effects of the heterozygous condition in the eye. Mitf mice can therefore be regarded as an important model system for the study of human disease. Thus, we characterized Mitfmi/+ mice at 1, 3, 12, and 18 months old in comparison with age-matched wild-type mice. The light- and dark-adapted electroretinogram (ERG) recordings showed progressive cone-rod dystrophy in Mitfmi/+ mice. The RPE response was reduced in the mutant in all age groups studied. Progressive loss of pigmentation was found in Mitfmi/+ mice. Histological retinal sections revealed evidence of retinal degeneration in Mitfmi/+ mice at older ages. For the first time, we report a mouse model of progressive cone-rod dystrophy and RPE dysfunction with a mutation in the Mitf gene.
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Affiliation(s)
- Andrea García-Llorca
- Department of Physiology, Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
| | | | - Arnór Thorri Sigurdsson
- Department of Physiology, Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
| | - Thor Eysteinsson
- Department of Physiology, Faculty of Medicine, University of Iceland, 101 Reykjavík, Iceland
- Department of Ophthalmology, Landspitali—National University Hospital, 101 Reykjavík, Iceland
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Anderson BD, Lee T, Bell B, Song Y, Dunaief JL. Low ceruloplasmin levels exacerbate retinal degeneration in a hereditary hemochromatosis model. Dis Model Mech 2023; 16:dmm050226. [PMID: 37439255 PMCID: PMC10354715 DOI: 10.1242/dmm.050226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 06/09/2023] [Indexed: 07/14/2023] Open
Abstract
In a previous report, a 39-year-old patient with high serum iron levels from hereditary hemochromatosis (HH) was diagnosed with a form of retinal degeneration called bull's eye maculopathy. This is atypical for patients with HH, so it was theorized that the low serum levels of ferroxidase ceruloplasmin (CP) of this patient coupled with the high iron levels led to the retinal degeneration. CP, by oxidizing iron from its ferrous to ferric form, helps prevent the oxidative damage caused by ferrous iron. To test this, a hepcidin knockout (KO) mouse model of HH was combined with Cp KO to test whether the combination would lead to more severe retinal degeneration. Monthly in vivo retinal images were acquired and, after 11 months, mice were euthanized for further analyses. Both heterozygous and homozygous Cp KO increased the rate and severity of retinal degeneration. These results demonstrate the protective role of CP, which is most likely owing to its ferroxidase activity. The findings suggest that CP levels may influence the severity of retinal degeneration, especially in individuals with high serum iron.
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Affiliation(s)
- Brandon D. Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Timothy Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Brent Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ying Song
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Joshua L. Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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Bell BA, Kaul C, Dunaief JL, Hollyfield JG, Bonilha VL. A comparison of optophysiological biomarkers of photoreceptor stress and phototoxicity in BALB/cJ, B6 (Cg)-Tyrc-2J/J, and C57Bl/6J mouse strains. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1128311. [PMID: 38689597 PMCID: PMC11057998 DOI: 10.3389/fopht.2023.1128311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Ophthalmic imaging instruments, including the confocal scanning laser ophthalmoscope and spectral-domain optical coherence tomography system, originally intended for revealing ocular microstructures in the human eye, have been deployed by vision researchers to evaluate the eyes of numerous small and large animal species for more than two decades. In this study, we have used these two instruments to obtain imaging data sequentially from the retinas of three prominent, widely used experimental mouse models to document changes induced by two contrasting vivarium lighting conditions. Mice studied include albino BALB/cJ and B6(Cg)-Tyrc-2J/J and pigmented C57Bl/6J. Mice were reared under dim light conditions until ~8 weeks of age where they underwent baseline imaging. Following, mice were returned to the dim vivarium or relocated to the top rack cage position in a standard vivarium. Mice were then followed for several months by ocular imaging to catalog the retinal dynamics as a function of long-term dim vs. elevated, standard vivarium lighting exposure levels. Upon exposure to elevated light levels, B6(Cg)-Tyrc-2J/J underwent similar changes as BALB/cJ in regard to photoreceptor outer segment shortening, photoreceptor layer proximal aspect hyperreflective changes, and the development of retinal infoldings and autofluorescent sub-retinal inflammatory monocyte infiltrate. Noteworthy, however, is that infoldings and infiltrate occurred at a slower rate of progression in B6(Cg)-Tyrc-2J/J vs. BALB/cJ. The photoreceptor outer nuclear layer thickness of BALB/cJ degenerated steadily following elevated light onset. In contrast, B6(Cg)-Tyrc-2J/J degeneration was unremarkable for many weeks before experiencing a noticeable change in the rate of degeneration that was concomitant with a plateau and decreasing trend in number of retinal infoldings and monocyte infiltrate. Pathological changes in C57Bl/6J mice were unremarkable for all imaging biomarkers assessed with exception to autofluorescent sub-retinal inflammatory monocyte infiltrate, which showed significant accumulation in dim vs. elevated light exposed mice following ~1 year of observation. These data were evaluated using Spearman's correlation and Predictive Power Score matrices to determine the best imaging optophysiological biomarkers for indicating vivarium light stress and light-induced photoreceptor degeneration. This study suggests that changes in proximal aspect hyperreflectivity, outer segment shortening, retinal infoldings and autofluorescent sub-retinal inflammatory monocyte infiltrate are excellent indicators of light stress and light-induced degeneration in albino B6(Cg)-Tyrc-2J/J and BALB/cJ mouse strains.
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Affiliation(s)
- Brent A. Bell
- Scheie Eye Institute and Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, United States
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States
| | - Charles Kaul
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States
| | - Joshua L. Dunaief
- Scheie Eye Institute and Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, United States
| | - Joe G. Hollyfield
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Vera L. Bonilha
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
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Eleftheriou CG, Corona C, Khattak S, Alam NM, Ivanova E, Bianchimano P, Liu Y, Sun D, Singh R, Batoki JC, Prusky GT, McAnany JJ, Peachey NS, Romano C, Sagdullaev BT. Retinoschisin Deficiency Induces Persistent Aberrant Waves of Activity Affecting Neuroglial Signaling in the Retina. J Neurosci 2022; 42:6983-7000. [PMID: 35906066 PMCID: PMC9464019 DOI: 10.1523/jneurosci.2128-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 07/18/2022] [Accepted: 07/22/2022] [Indexed: 11/21/2022] Open
Abstract
Genetic disorders that present during development make treatment strategies particularly challenging because there is a need to disentangle primary pathophysiology from downstream dysfunction caused at key developmental stages. To provide a deeper insight into this question, we studied a mouse model of X-linked juvenile retinoschisis, an early-onset inherited condition caused by mutations in the Rs1 gene encoding retinoschisin (RS1) and characterized by cystic retinal lesions and early visual deficits. Using an unbiased approach in expressing the fast intracellular calcium indicator GCaMP6f in neuronal, glial, and vascular cells of the retina of RS1-deficient male mice, we found that initial cyst formation is paralleled by the appearance of aberrant spontaneous neuroglial signals as early as postnatal day 15, when eyes normally open. These presented as glutamate-driven wavelets of neuronal activity and sporadic radial bursts of activity by Müller glia, spanning all retinal layers and disrupting light-induced signaling. This study confers a role to RS1 beyond its function as an adhesion molecule, identifies an early onset for dysfunction in the course of disease, establishing a potential window for disease diagnosis and therapeutic intervention.SIGNIFICANCE STATEMENT Developmental disorders make it difficult to distinguish pathophysiology due to ongoing disease from pathophysiology due to disrupted development. Here, we investigated a mouse model for X-linked retinoschisis, a well defined monogenic degenerative disease caused by mutations in the Rs1 gene, which codes for the protein retinoschisin. We evaluated the spontaneous activity of explanted retinas lacking retinoschisin at key stages of development using the unbiased approach of ubiquitously expressing GCaMP6f in all retinal neurons, vasculature, and glia. In mice lacking RS1, we found that an array of novel phenotypes, which present around eye opening, are linked to glutamatergic neurotransmission and affect visual processing. These data identify a novel pathophysiology linked to RS1, and define a window where treatments might be best targeted.
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Affiliation(s)
- Cyril G Eleftheriou
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Carlo Corona
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | | | - Nazia M Alam
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Elena Ivanova
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
| | - Paola Bianchimano
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - Yang Liu
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
| | - Duo Sun
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
| | - Rupesh Singh
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Julia C Batoki
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Glen T Prusky
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
| | - J Jason McAnany
- Department of Ophthalmology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio 44195
- Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio 44106
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio 44195
| | | | - Botir T Sagdullaev
- Burke Neurological Institute, Weill Cornell Medicine, White Plains, New York 10605
- Regeneron Pharmaceuticals, Tarrytown, New York 10591
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Daniele LL, Han JYS, Samuels IS, Komirisetty R, Mehta N, McCord JL, Yu M, Wang Y, Boesze-Battaglia K, Bell BA, Du J, Peachey NS, Philp NJ. Glucose uptake by GLUT1 in photoreceptors is essential for outer segment renewal and rod photoreceptor survival. FASEB J 2022; 36:e22428. [PMID: 35766190 PMCID: PMC9438481 DOI: 10.1096/fj.202200369r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 05/27/2022] [Accepted: 06/10/2022] [Indexed: 02/07/2023]
Abstract
Photoreceptors consume glucose supplied by the choriocapillaris to support phototransduction and outer segment (OS) renewal. Reduced glucose supply underlies photoreceptor cell death in inherited retinal degeneration and age-related retinal disease. We have previously shown that restricting glucose transport into the outer retina by conditional deletion of Slc2a1 encoding GLUT1 resulted in photoreceptor loss and impaired OS renewal. However, retinal neurons, glia, and the retinal pigment epithelium play specialized, synergistic roles in metabolite supply and exchange, and the cell-specific map of glucose uptake and utilization in the retina is incomplete. In these studies, we conditionally deleted Slc2a1 in a pan-retinal or rod-specific manner to better understand how glucose is utilized in the retina. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic deletion of Slc2a1 from retinal neurons and Müller glia results in reduced OS growth and progressive rod but not cone photoreceptor cell death. Rhodopsin levels were severely decreased even at postnatal day 20 when OS length was relatively normal. Arrestin levels were not changed suggesting that glucose uptake is required to synthesize membrane glycoproteins. Rod-specific deletion of Slc2a1 resulted in similar changes in OS length and rod photoreceptor cell death. These studies demonstrate that glucose is an essential carbon source for rod photoreceptor cell OS maintenance and viability.
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Affiliation(s)
- Lauren L Daniele
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - John Y S Han
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Ivy S Samuels
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio, USA
| | - Ravikiran Komirisetty
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Nikhil Mehta
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Jessica L McCord
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Minzhong Yu
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
| | - Yekai Wang
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA.,Department of Biochemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, Penn Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brent A Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, West Virginia, USA.,Department of Biochemistry, West Virginia University, Morgantown, West Virginia, USA
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.,Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio, USA.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, Ohio, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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9
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Uyhazi KE, Aravand P, Bell BA, Wei Z, Leo L, Serrano LW, Pearson DJ, Shpylchak I, Pham J, Vasireddy V, Bennett J, Aleman TS. Treatment Potential for LCA5-Associated Leber Congenital Amaurosis. Invest Ophthalmol Vis Sci 2020; 61:30. [PMID: 32428231 PMCID: PMC7405811 DOI: 10.1167/iovs.61.5.30] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose To determine the therapeutic window for gene augmentation for Leber congenital amaurosis (LCA) associated with mutations in LCA5. Methods Five patients (ages 6–31) with LCA and biallelic LCA5 mutations underwent an ophthalmic examination including optical coherence tomography (SD-OCT), full-field stimulus testing (FST), and pupillometry. The time course of photoreceptor degeneration in the Lca5gt/gt mouse model and the efficacy of subretinal gene augmentation therapy with AAV8-hLCA5 delivered at postnatal day 5 (P5) (early, n = 11 eyes), P15 (mid, n = 14), and P30 (late, n = 13) were assessed using SD-OCT, histologic study, electroretinography (ERG), and pupillometry. Comparisons were made with the human disease. Results Patients with LCA5-LCA showed a maculopathy with detectable outer nuclear layer (ONL) in the pericentral retina and at least 4 log units of dark-adapted sensitivity loss. The Lca5gt/gt mouse has a similarly severe and rapid photoreceptor degeneration. The ONL became progressively thinner and was undetectable by P60. Rod- and cone-mediated ERGs were severely reduced in amplitudes at P30 and became nondetectable by P60. Subretinal AAV8-hLCA5 administered to Lca5gt/gt mice at P5 and P15, but not at P30, resulted in structural and functional rescue. Conclusions LCA5-LCA is a particularly severe form of LCA that was recapitulated in the Lca5gt/gt mouse. Gene augmentation resulted in structural and functional rescue in the Lca5gt/gt mouse if delivered before P30. Retained photoreceptors were visible within the central retina in all patients with LCA5-LCA, at a level equivalent to that observed in rescued Lca5gt/gt mice, suggesting a window of opportunity for the treatment of patients with LCA5-LCA.
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10
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Development of a Cx46 Targeting Strategy for Cancer Stem Cells. Cell Rep 2020; 27:1062-1072.e5. [PMID: 31018124 PMCID: PMC6497083 DOI: 10.1016/j.celrep.2019.03.079] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 01/21/2019] [Accepted: 03/21/2019] [Indexed: 12/18/2022] Open
Abstract
Gap-junction-mediated cell-cell communication enables tumor cells to synchronize complex processes. We previously found that glioblastoma cancer stem cells (CSCs) express higher levels of the gap junction protein Cx46 compared to non-stem tumor cells (non-CSCs) and that this was necessary and sufficient for CSC maintenance. To understand the mechanism underlying this requirement, we use point mutants to disrupt specific functions of Cx46 and find that Cx46-mediated gap-junction coupling is critical for CSCs. To develop a Cx46 targeting strategy, we screen a clinically relevant small molecule library and identify clofazimine as an inhibitor of Cx46-specific cell-cell communication. Clofazimine attenuates proliferation, self-renewal, and tumor growth and synergizes with temozolomide to induce apoptosis. Although clofazimine does not cross the blood-brain barrier, the combination of clofazimine derivatives optimized for brain penetrance with standard-of-care therapies may target glioblastoma CSCs. Furthermore, these results demonstrate the importance of targeting cell-cell communication as an anti-cancer therapy.
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11
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Liu Y, Kinoshita J, Ivanova E, Sun D, Li H, Liao T, Cao J, Bell BA, Wang JM, Tang Y, Brydges S, Peachey NS, Sagdullaev BT, Romano C. Mouse models of X-linked juvenile retinoschisis have an early onset phenotype, the severity of which varies with genotype. Hum Mol Genet 2020; 28:3072-3090. [PMID: 31174210 DOI: 10.1093/hmg/ddz122] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/04/2019] [Accepted: 06/03/2019] [Indexed: 12/17/2022] Open
Abstract
X-linked juvenile retinoschisis (XLRS) is an early-onset inherited condition that affects primarily males and is characterized by cystic lesions of the inner retina, decreased visual acuity and contrast sensitivity and a selective reduction of the electroretinogram (ERG) b-wave. Although XLRS is genetically heterogeneous, all mouse models developed to date involve engineered or spontaneous null mutations. In the present study, we have studied three new Rs1 mutant mouse models: (1) a knockout with inserted lacZ reporter gene; (2) a C59S point mutant substitution and (3) an R141C point mutant substitution. Mice were studied from postnatal day (P15) to 28 weeks by spectral domain optical coherence tomography and ERG. Retinas of P21-22 mice were examined using biochemistry, single cell electrophysiology of retinal ganglion cells (RGCs) and by immunohistochemistry. Each model developed intraretinal schisis and reductions in the ERG that were greater for the b-wave than the a-wave. The phenotype of the C59S mutant appeared less severe than the other mutants by ERG at adult ages. RGC electrophysiology demonstrated elevated activity in the absence of a visual stimulus and reduced signal-to-noise ratios in response to light stimuli. Immunohistochemical analysis documented early abnormalities in all cells of the outer retina. Together, these results provide significant insight into the early events of XLRS pathophysiology, from phenotype differences between disease-causing variants to common mechanistic events that may play critical roles in disease presentation and progression.
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Affiliation(s)
- Yang Liu
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Junzo Kinoshita
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Elena Ivanova
- Burke Neurological Institute at Weill Cornell Medicine, White Plains, NY 10605, USA
| | - Duo Sun
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Hong Li
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Tara Liao
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Jingtai Cao
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Brent A Bell
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jacob M Wang
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Yajun Tang
- Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | | | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH 44195, USA.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44106, USA.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Botir T Sagdullaev
- Burke Neurological Institute at Weill Cornell Medicine, White Plains, NY 10605, USA
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12
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Han JYS, Kinoshita J, Bisetto S, Bell BA, Nowak RA, Peachey NS, Philp NJ. Role of monocarboxylate transporters in regulating metabolic homeostasis in the outer retina: Insight gained from cell-specific Bsg deletion. FASEB J 2020; 34:5401-5419. [PMID: 32112484 DOI: 10.1096/fj.201902961r] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 01/29/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023]
Abstract
The neural retina metabolizes glucose through aerobic glycolysis generating large amounts of lactate. Lactate flux into and out of cells is regulated by proton-coupled monocarboxylate transporters (MCTs), which are encoded by members of the Slc16a family. MCT1, MCT3, and MCT4 are expressed in the retina and require association with the accessory protein basigin, encoded by Bsg, for maturation and trafficking to the plasma membrane. Bsg-/- mice have severely reduced electroretinograms (ERGs) and progressive photoreceptor degeneration, which is presumed to be driven by metabolic dysfunction resulting from loss of MCTs. To understand the basis of the Bsg-/- phenotype, we generated mice with conditional deletion of Bsg in rods (RodΔBsg), cones (Cone∆Bsg), or retinal pigment epithelial cells (RPEΔBsg). RodΔBsg mice showed a progressive loss of photoreceptors, while ConeΔBsg mice did not display a degenerative phenotype. The RPEΔBsg mice developed a distinct phenotype characterized by severely reduced ERG responses as early as 4 weeks of age. The loss of lactate transporters from the RPE most closely resembled the phenotype of the Bsg-/- mouse, suggesting that the regulation of lactate levels in the RPE and the subretinal space is essential for the viability and function of photoreceptors.
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Affiliation(s)
- John Y S Han
- Department of Pathology, Anatomy, & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | | | - Sara Bisetto
- Department of Pathology, Anatomy, & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Brent A Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, USA
| | - Romana A Nowak
- Animal Sciences, University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy, & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
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13
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Kinoshita J, Hasan N, Bell BA, Peachey NS. Reduced expression of the nob8 gene does not normalize the distribution or function of mGluR6 in the mouse retina. Mol Vis 2019; 25:890-901. [PMID: 32025181 PMCID: PMC6982428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 12/30/2019] [Indexed: 11/21/2022] Open
Abstract
Purpose The Grm6nob8 mouse carries a missense mutation in the Grm6 gene (p.Met66Leu), and exhibits a reduced b-wave of the electroretinogram (ERG), abnormal localization of metabotropic glutamate receptor 6 (mGluR6) to the depolarizing bipolar cell (DBC) soma, and a reduced level of mGluR6 at the DBC dendritic tips. Although the underlying mechanism remains unknown, one possible explanation is that DBCs cannot efficiently traffic the mutant mGluR6. In that scenario, reducing the total amount of mutant mGluR6 protein might normalize localization, and thus, improve the ERG phenotype as well. The second purpose of this study was to determine whether the abnormal cellular distribution of mutant mGluR6 in Grm6nob8 retinas might induce late onset DBC degeneration. Methods We crossed Grm6nob8 animals with Grm6nob3 mice, which carry a null mutation in Grm6, to generate Grm6nob3/nob8 compound heterozygotes. We used western blotting to measure the total mGluR6 content, and immunohistochemistry to document mGluR6 localization within DBCs. In addition, we examined outer retinal function with ERG and retinal architecture in vivo with spectral domain optical coherence tomography (SD-OCT). Results The retinal content of mGluR6 was reduced in the retinas of the Grm6nob3/nob8 compound heterozygotes compared to the Grm6nob8 homozygotes. The cellular distribution of mGluR6 in the Grm6nob3/nob8 compound heterozygotes matched that of the Grm6nob8 homozygotes, with extensive expression throughout the DBC cell body and limited expression at the DBC dendritic tips. The dark-adapted ERG b-waves of the Grm6nob3/nob8 mice were reduced in comparison to those of the Grm6nob8 homozygotes at postnatal day 21 and 28. The overall ERG waveforms obtained from 4- through 68-week old Grm6nob8 mice were in general agreement for dark- and light-adapted conditions. The maximum response and sensitivity of the dark-adapted ERG b-wave did not change statistically significantly with age. SD-OCT revealed the maintained laminar structure of the retina, including a clear inner nuclear layer (INL) at each age examined (from 11 to 57 weeks old), although the INL in the mice older than 39 weeks of age was somewhat thinner than that seen at 11 weeks. Conclusions Mislocalization of mutant mGluR6 is not normalized by reducing the total mGluR6. Mislocalized mutant mGluR6 does not trigger substantial loss of DBCs.
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Affiliation(s)
| | - Nazarul Hasan
- Department of Biochemistry & Molecular Genetics, University of Louisville, Louisville, KY
| | | | - Neal S. Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH
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14
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Huckenpahler AL, Carroll J, Salmon AE, Sajdak BS, Mastey RR, Allen KP, Kaplan HJ, McCall MA. Noninvasive Imaging and Correlative Histology of Cone Photoreceptor Structure in the Pig Retina. Transl Vis Sci Technol 2019; 8:38. [PMID: 31867139 PMCID: PMC6922271 DOI: 10.1167/tvst.8.6.38] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 10/04/2019] [Indexed: 12/16/2022] Open
Abstract
PURPOSE To evaluate different methods of studying cone photoreceptor structure in wild-type (WT) and transgenic pigs carrying the human rhodopsin P23H mutant gene (TgP23H). METHODS For in vivo imaging, pigs were anesthetized with tiletamine-zolazepam and isoflurane and given lidocaine-bupivacaine retrobulbar injections. Stay sutures and a custom head mount were used to hold and steer the head for adaptive optics scanning light ophthalmoscopy (AOSLO). Six WT and TgP23H littermates were imaged at postnatal day 30 (P30), P90, and P180 with AOSLO and optical coherence tomography (OCT), and two additional sets of littermates were imaged at P3 and P15 with OCT only. AOSLO imaging and correlative differential interference contrast microscopy were performed on a P240 WT pig and on WT and TgP23H littermates at P30 and P180. RESULTS AOSLO cone density generally underestimates histology density (mean difference ± SD = 24.8% ± 21.4%). The intensity of the outer retinal hyperreflective OCT band attributed to photoreceptors is attenuated in TgP23H pigs at all ages. In contrast, AOSLO images show cones that retain inner and outer segments through P180. At retinal locations outside the visual streak, TgP23H pigs show a heterogeneous degenerating cone mosaic by using two criteria: variable contrast on a split detector AOSLO and high reflectivity on a confocal AOSLO. CONCLUSIONS AOSLO reveals that the cone mosaic is similar to ex vivo histology. Its use as a noninvasive tool will enable observation of morphologic changes that arise in the cone mosaic of TgP23H pigs over time. TRANSLATIONAL RELEVANCE Pigs are widely used for translational studies, and the ability to noninvasively assess cellular changes in the cone mosaic will facilitate more detailed investigations of new retinal disease models as well as outcomes of potential therapies.
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Affiliation(s)
- Alison L Huckenpahler
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alexander E Salmon
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Benjamin S Sajdak
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Rebecca R Mastey
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kenneth P Allen
- Biomedical Resource Center, Medical College of Wisconsin, Milwaukee, WI, USA
- Department of Microbiology & Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Henry J Kaplan
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
| | - Maureen A McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY, USA
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15
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Bell BA, Bonilha VL, Hagstrom SA, Anand-Apte B, Hollyfield JG, Samuels IS. Prolonged ocular exposure leads to retinal lesions in mice. Exp Eye Res 2019; 185:107672. [PMID: 31128100 DOI: 10.1016/j.exer.2019.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/06/2019] [Accepted: 05/20/2019] [Indexed: 02/06/2023]
Abstract
Retinal lesions in the posterior pole of laboratory mice occur due to native, developmental abnormalities or as a consequence of environmental or experimental conditions. In this study, we investigated the rate and extent of retinal lesions as a result of prolonged ocular exposure following general anesthesia. Following experimental preparation induction procedures (EPIP) involving general anesthesia, mydriasis/cycloplegia, and topical anesthesia to the cornea, two ocular recovery conditions (protected and unprotected) were tested within two different animal recovery chambers (open or closed). The anterior and posterior poles were evaluated for the development of retinal lesions using digital color photography, scanning laser ophthalmoscopy, and spectral-domain optical coherence during anesthesia recovery and up to 2.5 months thereafter. In some mice, electroretinograms, histological and immunohistological evaluations were performed to assess functional and structural changes that accompanied the retinal lesions detected by in vivo imaging. Our data suggests that prolonged ocular surface exposure to circulating ambient room air leads to significant anterior and posterior segment ocular complications. The most abundant, semi-reversible complication observed was the development of lesions in the outer retina, which had a 90% probability of occurring after 45 min of exposure. The lesions mostly resolved short-term, but functional and imaging evidence suggest that some perturbations to the outer retina may persist one or more months following initial development.
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Affiliation(s)
- Brent A Bell
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States.
| | - Vera L Bonilha
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States; Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, United States
| | - Stephanie A Hagstrom
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States; Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, United States
| | - Bela Anand-Apte
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States; Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, United States
| | - Joe G Hollyfield
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States; Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, United States
| | - Ivy S Samuels
- Cole Eye Institute/Ophthalmic Research, Cleveland Clinic, Cleveland, OH, United States; Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA
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16
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Dhingra A, Bell BA, Peachey NS, Daniele LL, Reyes-Reveles J, Sharp RC, Jun B, Bazan NG, Sparrow JR, Kim HJ, Philp NJ, Boesze-Battaglia K. Microtubule-Associated Protein 1 Light Chain 3B, (LC3B) Is Necessary to Maintain Lipid-Mediated Homeostasis in the Retinal Pigment Epithelium. Front Cell Neurosci 2018; 12:351. [PMID: 30349463 PMCID: PMC6186781 DOI: 10.3389/fncel.2018.00351] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/19/2018] [Indexed: 12/25/2022] Open
Abstract
Like other neurons, retinal cells utilize autophagic pathways to maintain cell homeostasis. The mammalian retina relies on heterophagy and selective autophagy to efficiently degrade and metabolize ingested lipids with disruption in autophagy associated degradation contributing to age related retinal disorders. The retinal pigment epithelium (RPE) supports photoreceptor cell renewal by daily phagocytosis of shed photoreceptor outer segments (OS). The daily ingestion of these lipid-rich OS imposes a constant degradative burden on these terminally differentiated cells. These cells rely on Microtubule-Associated Protein 1 Light Chain 3 (LC3) family of proteins for phagocytic clearance of the ingested OS. The LC3 family comprises of three highly homologous members, MAP1LC3A (LC3A), MAP1LC3B (LC3B), and MAP1LC3C (LC3C). The purpose of this study was to determine whether the LC3B isoform plays a specific role in maintaining RPE lipid homeostasis. We examined the RPE and retina of the LC3B-/- mouse as a function of age using in vivo ocular imaging and electroretinography coupled with ex vivo, lipidomic analyses of lipid mediators, assessment of bisretinoids as well as imaging of lipid aggregates. Deletion of LC3B resulted in defects within the RPE including increased phagosome accumulation, decreased fatty acid oxidation and a subsequent increase in RPE and sub-RPE lipid deposits. Age-dependent RPE changes included elevated levels of oxidized cholesterol, deposition of 4-HNE lipid peroxidation products, bisretinoid lipofuscin accumulation, and subretinal migration of microglia, collectively likely contributing to loss of retinal function. These observations are consistent with a critical role for LC3B-dependent processes in the maintenance of normal lipid homeostasis in the aging RPE, and suggest that LC3 isoform specific disruption in autophagic processes contribute to AMD-like pathogenesis.
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Affiliation(s)
- Anuradha Dhingra
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Brent A Bell
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States.,Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Lauren L Daniele
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Juan Reyes-Reveles
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Rachel C Sharp
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Bokkyoo Jun
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, United States
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University Medical Center, New York, NY, United States
| | - Hye Jin Kim
- Department of Ophthalmology, Columbia University Medical Center, New York, NY, United States
| | - Nancy J Philp
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, United States
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17
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Swarup A, Bell BA, Du J, Han JYS, Soto J, Abel ED, Bravo-Nuevo A, FitzGerald PG, Peachey NS, Philp NJ. Deletion of GLUT1 in mouse lens epithelium leads to cataract formation. Exp Eye Res 2018; 172:45-53. [PMID: 29604281 PMCID: PMC6716165 DOI: 10.1016/j.exer.2018.03.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
The primary energy substrate of the lens is glucose and uptake of glucose from the aqueous humor is dependent on glucose transporters. GLUT1, the facilitated glucose transporter encoded by Slc2a1 is expressed in the epithelium of bovine, human and rat lenses. In the current study, we examined the expression of GLUT1 in the mouse lens and determined its role in maintaining lens transparency by studying effects of postnatal deletion of Slc2a1. In situ hybridization and immunofluorescence labeling were used to determine the expression and subcellular distribution of GLUT1 in the lens. Slc2a1 was knocked out of the lens epithelium by crossing transgenic mice expressing Cre recombinase under control of the GFAP promoter with Slc2a1loxP/loxP mice to generate Slc2a1loxP/loxP;GFAP-Cre+/0 (LensΔGlut1) mice. LensΔGlut1 mice developed visible lens opacities by around 3 months of age, which corresponded temporally with the total loss of detectable GLUT1 expression in the lens. Spectral domain optical coherence tomography (SD-OCT) imaging was used to monitor the formation of cataracts over time. SD-OCT imaging revealed that small nuclear cataracts were first apparent in the lenses of LensΔGlut1 mice beginning at about 2.7 months of age. Longitudinal SD-OCT imaging of LensΔGlut1 mice revealed disruption of mature secondary fiber cells after 3 months of age. Histological sections of eyes from LensΔGlut1 mice confirmed the disruption of the secondary fiber cells. The structural changes were most pronounced in fiber cells that had lost their organelles. In contrast, the histology of the lens epithelium in these mice appeared normal. Lactate and ATP were measured in lenses from LensΔGlut1 and control mice at 2 and 3 months of age. At 2 months of age, when GLUT1 was still detectable in the lens epithelium, albeit at low levels, the amount of lactate and ATP were not significantly different from controls. However, in lenses isolated from 3-month-old LensΔGlut1 mice, when GLUT1 was no longer detectable, levels of lactate and ATP were 50% lower than controls. Our findings demonstrate that in vivo, the transparency of mature lens fiber cells was dependent on glycolysis for ATP and the loss of GLUT1 transporters led to cataract formation. In contrast, lens epithelium and cortical fiber cells have mitochondria and could utilize other substrates to support their anabolic and catabolic needs.
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Affiliation(s)
- Aditi Swarup
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Brent A Bell
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jianhai Du
- West Virginia University Eye Institute, Morgantown, WV, USA
| | - John Y S Han
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jamie Soto
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA; Division of Endocrinology & Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA; Division of Endocrinology & Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Arturo Bravo-Nuevo
- Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA
| | - Paul G FitzGerald
- Department of Cell Biology & Human Anatomy, University of California at Davis, Davis, CA, USA
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
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18
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Charette JR, Earp SE, Bell BA, Ackert-Bicknell CL, Godfrey DA, Rao S, Anand-Apte B, Nishina PM, Peachey NS. A mutagenesis-derived Lrp5 mouse mutant with abnormal retinal vasculature and low bone mineral density. Mol Vis 2017; 23:140-148. [PMID: 28356706 PMCID: PMC5360454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 03/16/2017] [Indexed: 11/30/2022] Open
Abstract
PURPOSE Familial exudative vitreoretinopathy (FEVR) is caused by mutations in the genes encoding low-density lipoprotein receptor-related protein (LRP5) or its interacting partners, namely frizzled class receptor 4 (FZD4) and norrin cystine knot growth factor (NDP). Mouse models for Lrp5, Fzd4, and Ndp have proven to be important for understanding the retinal pathophysiology underlying FEVR and systemic abnormalities related to defective Wnt signaling. Here, we report a new mouse mutant, tvrm111B, which was identified by electroretinogram (ERG) screening of mice generated in the Jackson Laboratory Translational Vision Research Models (TVRM) mutagenesis program. METHODS ERGs were used to examine outer retinal physiology. The retinal vasculature was examined by in vivo retinal imaging, as well as by histology and immunohistochemistry. The tvrm111B locus was identified by genetic mapping of mice generated in a cross to DBA/2J, and subsequent sequencing analysis. Gene expression was examined by real-time PCR of retinal RNA. Bone mineral density (BMD) was examined by peripheral dual-energy X-ray absorptiometry. RESULTS The tvrm111B allele is inherited as an autosomal recessive trait. Genetic mapping of the decreased ERG b-wave phenotype of tvrm111B mice localized the mutation to a region on chromosome 19 that included Lrp5. Sequencing of Lrp5 identified the insertion of a cytosine (c.4724_4725insC), which is predicted to cause a frameshift that disrupts the last three of five conserved PPPSPxS motifs in the cytoplasmic domain of LRP5, culminating in a premature termination. In addition to a reduced ERG b-wave, Lrp5tvrm111B homozygotes have low BMD and abnormal features of the retinal vasculature that have been reported previously in Lrp5 mutant mice, including persistent hyaloid vessels, leakage on fluorescein angiography, and an absence of the deep retinal capillary bed. CONCLUSIONS The phenotype of the Lrp5tvrm111B mutant includes abnormalities of the retinal vasculature and of BMD. This model may be a useful resource to further our understanding of the biological role of LRP5 and to evaluate experimental therapies for FEVR or other conditions associated with LRP5 dysfunction.
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Affiliation(s)
| | - Sarah E. Earp
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH,Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | | | - Cheryl L. Ackert-Bicknell
- The Jackson Laboratory, Bar Harbor, ME,Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester, Rochester, NY
| | - Dana A. Godfrey
- Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester, Rochester, NY
| | - Sujata Rao
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH,Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | - Bela Anand-Apte
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH,Cole Eye Institute, Cleveland Clinic, Cleveland, OH
| | | | - Neal S. Peachey
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH,Cole Eye Institute, Cleveland Clinic, Cleveland, OH,Louis Stokes Cleveland VA Medical Center, Cleveland, OH
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Zhang L, Bell BA, Yu M, Chan CC, Peachey NS, Fung J, Zhang X, Caspi RR, Lin F. Complement anaphylatoxin receptors C3aR and C5aR are required in the pathogenesis of experimental autoimmune uveitis. J Leukoc Biol 2015; 99:447-54. [PMID: 26394814 DOI: 10.1189/jlb.3a0415-157r] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 09/03/2015] [Indexed: 12/19/2022] Open
Abstract
Recent studies have suggested that reagents inhibiting complement activation could be effective in treating T cell mediated autoimmune diseases such as autoimmune uveitis. However, the precise role of the complement anaphylatoxin receptors (C3a and C5a receptors) in the pathogenesis of autoimmune uveitis remains elusive and controversial. We induced experimental autoimmune uveitis in mice deficient or sufficient in both C3a and C5a receptors and rigorously compared their retinal phenotype using various imaging techniques, including indirect ophthalmoscopy, confocal scanning laser ophthalmoscopy, spectral domain optical coherence tomography, topical endoscopic fundus imaging, and histopathological analysis. We also assessed retinal function using electroretinography. Moreover, we performed Ag-specific T cell recall assays and T cell adoptive transfer experiments to compare pathogenic T cell activity between wild-type and knockout mice with experimental autoimmune uveitis. These experiments showed that C3a receptor/C5a receptor-deficient mice developed much less severe uveitis than did control mice using all retinal examination methods and that these mice had reduced pathogenic T cell responses. Our data demonstrate that both complement anaphylatoxin receptors are important for the development of experimental autoimmune uveitis, suggesting that targeting these receptors could be a valid approach for treating patients with autoimmune uveitis.
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Affiliation(s)
- Lingjun Zhang
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Brent A Bell
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Minzhong Yu
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Chi-Chao Chan
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Neal S Peachey
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - John Fung
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Xiaoming Zhang
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Rachel R Caspi
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Feng Lin
- *Eye Research Institute, Tianjin Medical University Eye Center, Tianjin, China; Department of Immunology, Lerner Research Institute, Department of Ophthalmic Research, Cole Eye Institute, and Digestive Disease Institute, Cleveland Clinic, Cleveland, Ohio, USA; and Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
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20
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Crespo-Garcia S, Reichhart N, Hernandez-Matas C, Zabulis X, Kociok N, Brockmann C, Joussen AM, Strauss O. In vivo analysis of the time and spatial activation pattern of microglia in the retina following laser-induced choroidal neovascularization. Exp Eye Res 2015. [PMID: 26213305 DOI: 10.1016/j.exer.2015.07.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Microglia play a major role in retinal neovascularization and degeneration and are thus potential targets for therapeutic intervention. In vivo assessment of microglia behavior in disease models can provide important information to understand patho-mechanisms and develop therapeutic strategies. Although scanning laser ophthalmoscope (SLO) permits the monitoring of microglia in transgenic mice with microglia-specific GFP expression, there are fundamental limitations in reliable identification and quantification of activated cells. Therefore, we aimed to improve the SLO-based analysis of microglia using enhanced image processing with subsequent testing in laser-induced neovascularization (CNV). CNV was induced by argon laser in MacGreen mice. Microglia was visualized in vivo by SLO in the fundus auto-fluorescence (FAF) mode and verified ex vivo using retinal preparations. Three image processing algorithms based on different analysis of sequences of images were tested. The amount of recorded frames was limiting the effectiveness of the different algorithms. Best results from short recordings were obtained with a pixel averaging algorithm, further used to quantify spatial and temporal distribution of activated microglia in CNV. Morphologically, different microglia populations were detected in the inner and outer retinal layers. In CNV, the peak of microglia activation occurred in the inner layer at day 4 after laser, lacking an acute reaction. Besides, the spatial distribution of the activation changed by the time over the inner retina. No significant time and spatial changes were observed in the outer layer. An increase in laser power did not increase number of activated microglia. The SLO, in conjunction with enhanced image processing, is suitable for in vivo quantification of microglia activation. This surprisingly revealed that laser damage at the outer retina led to more reactive microglia in the inner retina, shedding light upon a new perspective to approach the immune response in the retina in vivo.
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Affiliation(s)
- Sergio Crespo-Garcia
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Nadine Reichhart
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Carlos Hernandez-Matas
- Institute of Computer Science, Foundation for Research and Technology - Hellas, Heraklion, Greece; Computer Science Department, University of Crete, Heraklion, Greece
| | - Xenophon Zabulis
- Institute of Computer Science, Foundation for Research and Technology - Hellas, Heraklion, Greece
| | - Norbert Kociok
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Claudia Brockmann
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Antonia M Joussen
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany
| | - Olaf Strauss
- Department of Ophthalmology, Charité University Medicine Berlin, Berlin, Germany.
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21
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Bonilha VL, Bell BA, Rayborn ME, Yang X, Kaul C, Grossman GH, Samuels IS, Hollyfield JG, Xie C, Cai H, Shadrach KG. Loss of DJ-1 elicits retinal abnormalities, visual dysfunction, and increased oxidative stress in mice. Exp Eye Res 2015. [PMID: 26215528 DOI: 10.1016/j.exer.2015.07.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
DJ-1/PARK7 mutations or deletions cause autosomal recessive early onset Parkinson's disease (PD). Thus, DJ-1 protein has been extensively studied in brain and neurons. PD patients display visual symptoms; however, the visual symptoms specifically attributed to PD patients carrying DJ-1/PARK7 mutations are not known. In this study, we analyzed the structure and physiology of retinas of 3- and 6-month-old DJ-1 knockout (KO) mice to determine how loss of function of DJ-1 specifically contributes to the phenotypes observed in PD patients. As compared to controls, the DJ-1 KO mice displayed an increase in the amplitude of the scotopic ERG b-wave and cone ERG, while the amplitude of a subset of the dc-ERG components was decreased. The main structural changes in the DJ-1 KO retinas were found in the outer plexiform layer (OPL), photoreceptors and retinal pigment epithelium (RPE), which were observed at 3 months and progressively increased at 6 months. RPE thinning and structural changes within the OPL were observed in the retinas in DJ-1 KO mice. DJ-1 KO retinas also exhibited disorganized outer segments, central decrease in red/green cone opsin staining, decreased labeling of ezrin, broader distribution of ribeye labeling, decreased tyrosine hydroxylase in dopaminergic neurons, and increased 7,8-dihydro-8-oxoguanine-labeled DNA oxidation. Accelerated outer retinal atrophy was observed in DJ-1 KO mice after selective oxidative damage induced by a single tail vein injection of NaIO3, exposing increased susceptibility to oxidative stress. Our data indicate that DJ-1-deficient retinas exhibit signs of morphological abnormalities and physiological dysfunction in association with increased oxidative stress. Degeneration of RPE cells in association with oxidative stress is a key hallmark of age-related macular degeneration (AMD). Therefore, in addition to detailing the visual defects that occur as a result of the absence of DJ-1, our data is also relevant to AMD pathogenesis.
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Affiliation(s)
- Vera L Bonilha
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA.
| | - Brent A Bell
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Mary E Rayborn
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Xiaoping Yang
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Charlie Kaul
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Gregory H Grossman
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Ivy S Samuels
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Joe G Hollyfield
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Chengsong Xie
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD, USA
| | - Huaibin Cai
- Laboratory of Neurogenetics, National Institute on Aging, Bethesda, MD, USA
| | - Karen G Shadrach
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
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22
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Bell BA, Kaul C, Bonilha VL, Rayborn ME, Shadrach K, Hollyfield JG. The BALB/c mouse: Effect of standard vivarium lighting on retinal pathology during aging. Exp Eye Res 2015; 135:192-205. [PMID: 25895728 PMCID: PMC4446204 DOI: 10.1016/j.exer.2015.04.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/13/2015] [Accepted: 04/16/2015] [Indexed: 11/16/2022]
Abstract
BALB/cJ mice housed under normal vivarium lighting conditions can exhibit profound retinal abnormalities, including retinal infoldings, autofluorescent inflammatory cells, and photoreceptor degeneration. To explore the sensitivity of the outer retina to cyclic lighting during aging, a cohort of BALB/cJ mice was evaluated with Scanning Laser Ophthalmoscopy (SLO), Spectral-Domain Optical Coherence Tomography (OCT) and conventional histopathology. Mice were bred and reared in a low-illuminance (extracage/intracage: 13 lx/1 lx) vivarium under cyclic light (14 h light: 10 h dark). Retinal imaging (around postnatal day 70) was performed to screen for any pre-existing abnormalities and to establish a baseline. Mice with normal retinas were separated into groups (A, B, C) and placed on bottom (Groups A & B) or top (Group C) of the cage racks where cage illumination was <10 & 150 lx respectively. Experimental groups B & C were imaged multiple times over a 17 month period. Mice from group A (controls) were imaged only once post-baseline at various times for comparison to groups B & C. Mice were assessed by histology at 8, 15, 20, 36, and 56 weeks and immunohistochemistry at 15 weeks post-baseline. SLO and OCT retinal images were measured and the resulting trends displayed as a function of age and light exposure. Retinal lesions (RL) and autofluorescent foci (AFF) were identified with histology as photoreceptor layer infoldings (IF) and localized microglia/macrophages (MM), respectively. Few RL and AFF were evident at baseline. Retinal infoldings were the earliest changes followed by subjacent punctate autofluorescent MM. The colocalization of IF and MM suggests a causal relationship. The incidence of these pathological features increased in all groups relative to baseline. OCT imaging revealed thinning of the outer nuclear layer (ONL) in all groups at 1 year relative to baseline. ONL thinning followed an exponential rate of change but the decay constant varied depending on intensity of illumination of the groups. Advanced age and top row illuminance conditions resulted in significant photoreceptor cell loss as judged by decreased thickness of the ONL. Photoreceptor loss was preceded by both retinal infoldings and the presence of autofluorescent inflammatory cells in the outer retina, suggesting that these changes are early indicators of light toxicity in the BALB/cJ mouse.
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Affiliation(s)
- Brent A Bell
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Charles Kaul
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Vera L Bonilha
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Mary E Rayborn
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Karen Shadrach
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Joe G Hollyfield
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA.
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