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Freeman TL, McElroy AK. Laboratory Animal Models for Rift Valley Fever Virus Disease. Methods Mol Biol 2024; 2824:425-445. [PMID: 39039428 DOI: 10.1007/978-1-0716-3926-9_27] [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] [Indexed: 07/24/2024]
Abstract
Rift Valley fever virus (RVFV) is an arboviral pathogen of clinical and agricultural relevance. The ongoing development of targeted RVFV prophylactics and therapeutics is overwhelmingly dependent on animal models due to both natural, that is, sporadic outbreaks, and structural, for example, underresourcing of endemic regions, limitations in accessing human patient samples and cohorts. Elucidating mechanisms of viral pathogenesis and testing therapeutics is further complicated by the diverse manifestations of RVFV disease and the heterogeneity of the host response to infection. In this chapter, we describe major clinical manifestations of RVFV infection and discuss the laboratory animal models used to study each.
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Affiliation(s)
- Tracey L Freeman
- University of Pittsburgh School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Disease, Pittsburgh, PA, USA
- University of Pittsburgh Center for Vaccine Research, Pittsburgh, PA, USA
| | - Anita K McElroy
- University of Pittsburgh School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Disease, Pittsburgh, PA, USA.
- University of Pittsburgh Center for Vaccine Research, Pittsburgh, PA, USA.
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2
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Shamshad A, Kang C, Jenny LA, Persad-Paisley EM, Tsang SH. Translatability barriers between preclinical and clinical trials of AAV gene therapy in inherited retinal diseases. Vision Res 2023; 210:108258. [PMID: 37244011 PMCID: PMC10526971 DOI: 10.1016/j.visres.2023.108258] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/02/2023] [Accepted: 05/09/2023] [Indexed: 05/29/2023]
Abstract
Inherited retinal diseases (IRDs) are progressive degenerative diseases which cause gradual vision loss or complete blindness. As over 270 gene mutations have been identified in the underlying pathology of IRDs, gene therapy as a treatment modality has been an increasingly active realm of investigation. Currently, the most common vehicle of ocular gene delivery is the adeno-associated virus (AAV) vector. This is injected into the immune-privileged subretinal space to mediate transgene expression in retinal cells. Although numerous animal models of IRDs have demonstrated successful outcomes following AAV-mediated gene delivery, many of these studies fail to translate into successful outcomes in clinical trials. The purpose of this review is to A) comparatively assess preclinical and clinical IRD trials in which the success of AAV-mediated therapy failed to translate between animal and human participants B) discuss factors which may complicate the translatability of gene therapy in animals to results in humans.
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Affiliation(s)
| | - Chaerim Kang
- Warren Alpert Medical School of Brown University, USA
| | - Laura A Jenny
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA; Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA
| | | | - Stephen H Tsang
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, NY, USA; Jonas Children's Vision Care, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA; Department of Pathology and Cell Biology, Columbia University, New York, NY, USA; Department of Biomedical Engineering, Columbia University, New York, NY, USA; Columbia Stem Cell Initiative, Columbia University, New York, NY, USA; Insitute of Human Nutrition, Columbia University, New York, NY, USA
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3
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Bussing D, Li Y, Guo L, Verma A, Sullivan JM, Shah DK. Pharmacokinetics of Monoclonal Antibody and Antibody Fragments in The Mouse Eye Following Intravitreal Administration. J Pharm Sci 2023; 112:2276-2284. [PMID: 37062415 DOI: 10.1016/j.xphs.2023.04.006] [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: 12/23/2022] [Revised: 04/08/2023] [Accepted: 04/09/2023] [Indexed: 04/18/2023]
Abstract
Mice are rarely used in pharmacokinetic (PK) studies of ocular therapeutics due to the small size of their eyes and challenges in drug administration, tissue collection, and analysis of drug concentrations. Therefore, ocular PK of protein therapeutics in mouse eye following intravitreal (IVT) administration is not known. Here, we have presented the first of its kind investigation, to study the PK of 4 different size non-binding protein therapeutics in mouse plasma, cornea/ICB, vitreous humor, retina, and posterior cup (including choroid) following IVT administration. Administered proteins include trastuzumab (150 kDa) and F(ab)2 (100 kDa), Fab, and scFv (27 kDa) fragments of trastuzumab. An imaging and injection apparatus suitable for performing small (50 nL) IVT injections in mice was developed, and techniques for enucleation of the eye and dissection of ocular tissues were developed. Furthermore, a sensitive enzyme-linked immunosorbent assay (ELISA) for detection of proteins in very small amounts of ocular tissues were developed. It was observed that elimination from the vitreous chamber was the primary driver of PK in the cornea/ICB, retina, posterior cup, and plasma. Trastuzumab displays first-order kinetics in the vitreous humor with a half-life of 18.8 h. F(ab)2, Fab, and ScFv show biphasic PK profiles with distribution phases becoming more rapid as molecular weight decreases, and terminal elimination becoming longer as molecular weight decreases, with terminal half-lives of 16.3, 20.6, and 48.9 h, respectively. The mean residence times of trastuzumab, F(ab)2, Fab, and scFv in the vitreous humor were 26.0, 12.2, 10.7, and 8.16 h, respectively. It was found that the mean residence time in vitreous humor doubles with an increase in molecular weight of ∼69 kDa. Interestingly, the PK of proteins measured in the un-injected eye suggest the presence of a pathway for drug transfer between the eyes, which needs to be further validated. Overall, the findings presented here pave the way for drug discovery and development studies of protein therapeutics for ophthalmic indications in mice.
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Affiliation(s)
- David Bussing
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Yingyi Li
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Leiming Guo
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Ashwni Verma
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, New York, USA
| | - Jack M Sullivan
- Department of Ophthalmology, Jacobs School of Medicine & Biomedical Sciences, Buffalo, New York, USA; VA Western NY Healthcare System, Buffalo, New York, USA
| | - Dhaval K Shah
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, Buffalo, New York, USA.
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Eltanahy AM, Franco C, Jeyaraj P, Goswami S, Hughes E, Gonzales AL. Ex vivo ocular perfusion model to study vascular physiology in the mouse eye. Exp Eye Res 2023; 233:109543. [PMID: 37390954 PMCID: PMC10637262 DOI: 10.1016/j.exer.2023.109543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 05/30/2023] [Accepted: 06/16/2023] [Indexed: 07/02/2023]
Abstract
Several hypotheses have been tested to understand whole organ regulation in other organs such as the brain and kidney, but no such hypothesis has yet been proposed for ocular circulations. To some extent resolve this deficit our ex vivo mouse eye perfusion model takes the first step in elucidating the mechanisms controlling the individual components of the ocular circulation. Various isolated ocular vascular preparations have been utilized in studies of ocular vascular biology, physiology, and pharmacology, including studies on both normal and pathological conditions. However, there is still significant potential for further studies to improve our understanding of ocular circulation and its regulation. The choroid specifically is inaccessible to direct visualization due to the retina's high metabolic requirement with a transparency that cannot be compromised by an overly rich vascular network on the inner retinal side hindering the visualization of the choroid. In this technical paper, we provide a detailed description of all the steps to be followed from the enucleation of mouse eyes to cannulation of the ophthalmic artery and perfusion and ex vivo confocal microscopy imaging of the dynamic nature of the choroid circulation.
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Affiliation(s)
- Ahmed M Eltanahy
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557-0318, USA
| | - Cristian Franco
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557-0318, USA
| | - Priscilla Jeyaraj
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557-0318, USA
| | - Shipra Goswami
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557-0318, USA
| | - Elena Hughes
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557-0318, USA
| | - Albert L Gonzales
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557-0318, USA.
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Luzzio A, Edie S, Palmer K, Caddle LB, Urban R, Goodwin LO, Welsh IC, Reinholdt LG, Bergstrom DE, Cox TC, Donahue LR, Murray SA. The spontaneous mouse mutant low set ears (Lse) is caused by tandem duplication of Fgf3 and Fgf4. Mamm Genome 2023:10.1007/s00335-023-09999-8. [PMID: 37341808 DOI: 10.1007/s00335-023-09999-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 05/18/2023] [Indexed: 06/22/2023]
Abstract
The external ear develops from an organized convergence of ventrally migrating neural crest cells into the first and second branchial arches. Defects in external ear position are often symptomatic of complex syndromes such as Apert, Treacher-Collins, and Crouzon Syndrome. The low set ears (Lse) spontaneous mouse mutant is characterized by the dominant inheritance of a ventrally shifted external ear position and an abnormal external auditory meatus (EAM). We identified the causative mutation as a 148 Kb tandem duplication on Chromosome 7, which includes the entire coding sequences of Fgf3 and Fgf4. Duplications of FGF3 and FGF4 occur in 11q duplication syndrome in humans and are associated with craniofacial anomalies, among other features. Intercrosses of Lse-affected mice revealed perinatal lethality in homozygotes, and Lse/Lse embryos display additional phenotypes including polydactyly, abnormal eye morphology, and cleft secondary palate. The duplication results in increased Fgf3 and Fgf4 expression in the branchial arches and additional discrete domains in the developing embryo. This ectopic overexpression resulted in functional FGF signaling, demonstrated by increased Spry2 and Etv5 expression in overlapping domains of the developing arches. Finally, a genetic interaction between Fgf3/4 overexpression and Twist1, a regulator of skull suture development, resulted in perinatal lethality, cleft palate, and polydactyly in compound heterozygotes. These data indicate a role for Fgf3 and Fgf4 in external ear and palate development and provide a novel mouse model for further interrogation of the biological consequences of human FGF3/4 duplication.
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Affiliation(s)
| | - Sarah Edie
- The Jackson Laboratory, Bar Harbor, ME, USA
| | | | | | | | | | | | | | | | - Timothy C Cox
- Departments of Oral & Craniofacial Sciences and Pediatrics, University of Missouri-Kansas City, Kansas City, MO, USA
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Kocherlakota S, Swinkels D, Van Veldhoven PP, Baes M. Mouse Models to Study Peroxisomal Functions and Disorders: Overview, Caveats, and Recommendations. Methods Mol Biol 2023; 2643:469-500. [PMID: 36952207 DOI: 10.1007/978-1-0716-3048-8_34] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
During the last three decades many mouse lines were created or identified that are deficient in one or more peroxisomal functions. Different methodologies were applied to obtain global, hypomorph, cell type selective, inducible, and knockin mice. Whereas some models closely mimic pathologies in patients, others strongly deviate or no human counterpart has been reported. Often, mice, apparently endowed with a stronger transcriptional adaptation, have to be challenged with dietary additions or restrictions in order to trigger phenotypic changes. Depending on the inactivated peroxisomal protein, several approaches can be taken to validate the loss-of-function. Here, an overview is given of the available mouse models and their most important characteristics.
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Affiliation(s)
- Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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Abdolkarimi D, Cunha DL, Lahne1 M, Moosajee M. PAX6 disease models for aniridia. Indian J Ophthalmol 2022; 70:4119-4129. [PMID: 36453299 PMCID: PMC9940591 DOI: 10.4103/ijo.ijo_316_22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/01/2022] [Accepted: 08/10/2022] [Indexed: 12/12/2022] Open
Abstract
Aniridia is a pan-ocular genetic developmental eye disorder characterized by complete or partial iris and foveal hypoplasia, for which there is no treatment currently. Progressive sight loss can arise from cataracts, glaucoma, and aniridia-related keratopathy, which can be managed conservatively or through surgical intervention. The vast majority of patients harbor heterozygous mutations involving the PAX6 gene, which is considered the master transcription factor of early eye development. Over the past decades, several disease models have been investigated to gain a better understanding of the molecular pathophysiology, including several mouse and zebrafish strains and, more recently, human-induced pluripotent stem cells (hiPSCs) derived from aniridia patients. The latter provides a more faithful cellular system to study early human eye development. This review outlines the main aniridia-related animal and cellular models used to study aniridia and highlights the key discoveries that are bringing us closer to a therapy for patients.
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Affiliation(s)
| | - Dulce Lima Cunha
- UCL Institute of Ophthalmology, London, UK
- Radboud Institute for Molecular Life Sciences, Radboud University, Nijmegen, Netherlands
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- The Francis Crick Institute, London, UK
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Phenotype Characterization of a Mice Genetic Model of Absolute Blindness. Int J Mol Sci 2022; 23:ijms23158152. [PMID: 35897728 PMCID: PMC9331777 DOI: 10.3390/ijms23158152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 11/17/2022] Open
Abstract
Recent technological development requires new approaches to address the problem of blindness. Such approaches need to be able to ensure that no cells with photosensitive capability remain in the retina. The presented model, Opn4−/− × Pde6brd10/rd10 (O×Rd) double mutant murine, is a combination of a mutation in the Pde6b gene (photoreceptor degeneration) together with a deletion of the Opn4 gene (responsible for the expression of melanopsin in the intrinsically photosensitive retinal ganglion cells). This model has been characterized and compared with those of WT mice and murine animal models displaying both mutations separately. A total loss of pupillary reflex was observed. Likewise, behavioral tests demonstrated loss of rejection to illuminated spaces and a complete decrease in visual acuity (optomotor test). Functional recordings showed an absolute disappearance of various wave components of the full-field and pattern electroretinogram (fERG, pERG). Likewise, visual evoked potential (VEP) could not be recorded. Immunohistochemical staining showed marked degeneration of the outer retinal layers and the absence of melanopsin staining. The combination of both mutations has generated an animal model that does not show any photosensitive element in its retina. This model is a potential tool for the study of new ophthalmological approaches such as optosensitive agents.
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Bussing D, Li Z, Li Y, Chang HP, Chang HY, Guo L, Verma A, Shah DK. Pharmacokinetics of Monoclonal Antibody and Antibody Fragments in the Mouse Eye Following Systemic Administration. AAPS JOURNAL 2021; 23:116. [PMID: 34750690 PMCID: PMC8575492 DOI: 10.1208/s12248-021-00647-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/15/2021] [Indexed: 11/30/2022]
Abstract
The ocular pharmacokinetics (PK) of antibody-based therapies are infrequently studied in mice due to the technical difficulties in working with the small murine eye. This study is the first of its kind to quantitatively measure the PK of variously sized proteins in the plasma, cornea/ICB, vitreous humor, retina, and posterior cup (including choroid) of the mouse and to evaluate the relationship between molecular weight (MW) and antibody biodistribution coefficient (BC) to the eye. Proteins analyzed include trastuzumab (150 kDa), trastuzumab-vc-MMAE (T-vc-MMAE, 155 kDa), F(ab)2 (100 kDa), Fab (50 kDa), and scFv (27 kDa). As expected, ocular PK mirrored the systemic PK as plasma was the driving force for ocular exposure. For trastuzumab, T-vc-MMAE, F(ab)2, Fab, and scFv, respectively, the BCs in the cornea/ICB were 0.610%, 0.475%, 1.74%, 3.39%, and 13.7%; the BCs in the vitreous humor were 0.0198%, 0.0427%, 0.0934%, 0.234%, and 5.56%; the BCs for the retina were 0.539%, 0.230%, 0.704%, 2.44%, and 20.4%; the BCs for the posterior cup were 0.557%, 0.650%, 1.47%, 4.06%, and 13.9%. The relationship between BC and MW was best characterized by a log–log regression in which BC decreased as MW increased, with every doubling in MW leading to a decrease in BC by a factor of 3.44 × , 6.76 × , 4.74 × , and 3.43 × in cornea/ICB, vitreous humor, retina, and posterior cup, respectively. In analyzing the disposition of protein therapeutics to the eye, these findings enhance our understanding of the potential for ocular toxicity of systemically administered protein therapeutics and may aid in the discovery of systemically administered protein therapeutics for ocular disorders.
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Affiliation(s)
- David Bussing
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Zhe Li
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Yingyi Li
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Hsuan-Ping Chang
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Hsueh-Yuan Chang
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Leiming Guo
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Ashwni Verma
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA
| | - Dhaval K Shah
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, The State University of New York at Buffalo, 455 Pharmacy Building, Buffalo, New York, 14214-8033, USA.
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Brunet AA, Fuller-Carter PI, Miller AL, Voigt V, Vasiliou S, Rashwan R, Hunt DM, Carvalho LS. Validating Fluorescent Chrnb4.EGFP Mouse Models for the Study of Cone Photoreceptor Degeneration. Transl Vis Sci Technol 2020; 9:28. [PMID: 32879784 PMCID: PMC7442867 DOI: 10.1167/tvst.9.9.28] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/29/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose To validate the application of a known transgenic mouse line with green fluorescent cones (Chrnb4.EGFP) to study cone photoreceptor biology and function in health and disease. Methods Chrnb4.EGFP retinas containing GFP+ cones were compared with retinas without the GFP transgene via immunohistochemistry, quantitative real-time polymerase chain reaction, electroretinograms, and flow cytometry. The Chrnb4.EGFP line was backcrossed to the mouse models of cone degeneration, Pde6ccpfl1 and Gnat2cpfl3 , generating the new lines Gnat2.GFP and Pde6c.GFP, which were also studied as described. Results GFP expression spanned the length of the cone cell in the Chrnb4.EGFP line, as well as in the novel Gnat2.GFP and Pde6c.GFP lines. The effect of GFP expression showed no significant changes to outer nuclear layer cell death, cone-specific gene expression, and immune response activation. A temporal decrease in GFP expression over time was observed, but GFP fluorescence was still detected through flow cytometry as late as 6 months. Furthermore, a functional analysis of photopic and scotopic electroretinogram responses of the Chrnb4 mouse showed no significant difference between GFP- and GFP+ mice, whereas electroretinogram recordings for the Pde6c.GFP and Gnat2.GFP lines matched previous reports from the original lines. Conclusions This study demonstrates that the Chrnb4.EGFP mouse can be a powerful tool to overcome the limitations of studying cone biology, including the use of this line to study different types of cone degeneration. Translational Relevance This work validates research tools that could potentially offer more reliable preclinical data in the development of treatments for cone-mediated vision loss conditions, shortening the gap to clinical translation.
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Affiliation(s)
- Alicia A. Brunet
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | | | - Annie L. Miller
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | | | | | - Rabab Rashwan
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Department of Microbiology and Immunology, Faculty of Medicine, Minia University, Minia, Egypt
| | - David M. Hunt
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Livia S. Carvalho
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
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Collin GB, Gogna N, Chang B, Damkham N, Pinkney J, Hyde LF, Stone L, Naggert JK, Nishina PM, Krebs MP. Mouse Models of Inherited Retinal Degeneration with Photoreceptor Cell Loss. Cells 2020; 9:cells9040931. [PMID: 32290105 PMCID: PMC7227028 DOI: 10.3390/cells9040931] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/12/2022] Open
Abstract
Inherited retinal degeneration (RD) leads to the impairment or loss of vision in millions of individuals worldwide, most frequently due to the loss of photoreceptor (PR) cells. Animal models, particularly the laboratory mouse, have been used to understand the pathogenic mechanisms that underlie PR cell loss and to explore therapies that may prevent, delay, or reverse RD. Here, we reviewed entries in the Mouse Genome Informatics and PubMed databases to compile a comprehensive list of monogenic mouse models in which PR cell loss is demonstrated. The progression of PR cell loss with postnatal age was documented in mutant alleles of genes grouped by biological function. As anticipated, a wide range in the onset and rate of cell loss was observed among the reported models. The analysis underscored relationships between RD genes and ciliary function, transcription-coupled DNA damage repair, and cellular chloride homeostasis. Comparing the mouse gene list to human RD genes identified in the RetNet database revealed that mouse models are available for 40% of the known human diseases, suggesting opportunities for future research. This work may provide insight into the molecular players and pathways through which PR degenerative disease occurs and may be useful for planning translational studies.
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Affiliation(s)
- Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Navdeep Gogna
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Jai Pinkney
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Jürgen K. Naggert
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
| | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, ME 04609, USA; (G.B.C.); (N.G.); (B.C.); (N.D.); (J.P.); (L.F.H.); (L.S.); (J.K.N.)
- Correspondence: (P.M.N.); (M.P.K.); Tel.: +1-207-2886-383 (P.M.N.); +1-207-2886-000 (M.P.K.)
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Storchi R, Rodgers J, Gracey M, Martial FP, Wynne J, Ryan S, Twining CJ, Cootes TF, Killick R, Lucas RJ. Measuring vision using innate behaviours in mice with intact and impaired retina function. Sci Rep 2019; 9:10396. [PMID: 31316114 PMCID: PMC6637134 DOI: 10.1038/s41598-019-46836-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 06/26/2019] [Indexed: 01/23/2023] Open
Abstract
Measuring vision in rodents is a critical step for understanding vision, improving models of human disease, and developing therapies. Established behavioural tests for perceptual vision, such as the visual water task, rely on learning. The learning process, while effective for sighted animals, can be laborious and stressful in animals with impaired vision, requiring long periods of training. Current tests that that do not require training are based on sub-conscious, reflex responses (e.g. optokinetic nystagmus) that don't require involvement of visual cortex and higher order thalamic nuclei. A potential alternative for measuring vision relies on using visually guided innate defensive responses, such as escape or freeze, that involve cortical and thalamic circuits. In this study we address this possibility in mice with intact and degenerate retinas. We first develop automatic methods to detect behavioural responses based on high dimensional tracking and changepoint detection of behavioural time series. Using those methods, we show that visually guided innate responses can be elicited using parametisable stimuli, and applied to describing the limits of visual acuity in healthy animals and discriminating degrees of visual dysfunction in mouse models of retinal degeneration.
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Affiliation(s)
- R Storchi
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
| | - J Rodgers
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - M Gracey
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - F P Martial
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - J Wynne
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - S Ryan
- Department of Mathematics and Statistics, Lancaster University, Lancaster, UK
| | - C J Twining
- School of Computer Science, University of Manchester, Manchester, UK
| | - T F Cootes
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - R Killick
- Department of Mathematics and Statistics, Lancaster University, Lancaster, UK
| | - R J Lucas
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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13
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Liu YH, Corbett C, Klaska IP, Makinen K, Nickerson JM, Cornall RJ, Kuffova L, Forrester JV. Partial retinal photoreceptor loss in a transgenic mouse model associated with reduced levels of interphotoreceptor retinol binding protein (IRBP, RBP3). Exp Eye Res 2018; 172:54-65. [PMID: 29571629 DOI: 10.1016/j.exer.2018.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 03/09/2018] [Accepted: 03/19/2018] [Indexed: 10/17/2022]
Abstract
Organ-specific transgenic membrane expression of hen egg lysozyme (HEL) as a "neo-self antigen" has been used in several models to study immunological tolerance. In this study we report the changes which occur in the B10.BR mouse retina when membrane-bound HEL is expressed in photoreceptors under the control of the promoter for interphotoreceptor retinoid binding protein (IRBP, RBP3). On direct clinical examination of the single transgenic (sTg-IRBP:HEL) mouse fundus, a low-level increase in retinal degeneration compared to non-transgenic controls was observed, presenting as drusenoid deposits and occasional small patches of atrophy. On histological examination, there was an overall shortening of outer segments and loss of photoreceptor nuclei in sTg-IRBP:HEL mice, which was more pronounced in the retinal periphery, particularly inferiorly. The fundoscopically observed lesions did not correlate with the photoreceptor shortening/loss but appeared to be located at the level of the retinal pigment epithelium/choriocapillaris layer and were an exaggeration in size and number of similar age-related changes found in wild type (WT) mice. In addition, neither the atrophic lesions nor the photoreceptor shortening were associated with common retinal degeneration genes, nor were they caused by exposure to light damage since mice housed at both high and low ambient light levels had similar degrees of retinal degeneration. Instead, sTg-IRBP:HEL mice expressed reduced levels of soluble retinal IRBP compared to WT mice which were present from postnatal day16 (P16) and preceded development of photoreceptor shortening (onset P21). We propose that insertion of the HEL transgene in the photoreceptor membrane disrupted normal photoreceptor function and led to reduced levels of soluble IRBP and retinal thinning. A similar phenotype has been observed in IRBP deficient mice. Despite the retinal thinning, the amount of HEL expressed in the retina was sufficient to act as an autoantigenic target when the mice were crossed to the HEL T cell receptor Tg mouse, since double transgenic (dTg-IRBP:HEL) mice spontaneously developed a severe uveoretinitis with onset at weaning. We suggest that, although membrane expression of foreign transgene products is likely to modify the structure and function of tissues and cells, the technology provides useful models to investigate mechanisms of antigen-specific immunological tolerance.
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Affiliation(s)
- Yi-Hsia Liu
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| | - Clare Corbett
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK; School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Izabela P Klaska
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK; Institute of Ophthalmology, University College London, London, UK
| | - Kimmo Makinen
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK; Human Health, Novozymes A/S, Bagsvaerd, Denmark
| | | | | | - Lucia Kuffova
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK; Department of Ophthalmology, NHS Grampian, Aberdeen, UK
| | - John V Forrester
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK; University of Western Australia, Lions Eye Institute, Perth, Western Australia, Australia.
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14
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Abstract
The innate immune system is activated in a number of degenerative and inflammatory retinal disorders such as age-related macular degeneration (AMD). Retinal microglia, choroidal macrophages, and recruited monocytes, collectively termed 'retinal mononuclear phagocytes', are critical determinants of ocular disease outcome. Many publications have described the presence of these cells in mouse models for retinal disease; however, only limited aspects of their behavior have been uncovered, and these have only been uncovered using a single detection method. The workflow presented here describes a comprehensive analysis strategy that allows characterization of retinal mononuclear phagocytes in vivo and in situ. We present standardized working steps for scanning laser ophthalmoscopy of microglia from MacGreen reporter mice (mice expressing the macrophage colony-stimulating factor receptor GFP transgene throughout the mononuclear phagocyte system), quantitative analysis of Iba1-stained retinal sections and flat mounts, CD11b-based retinal flow cytometry, and qRT-PCR analysis of key microglia markers. The protocol can be completed within 3 d, and we present data from retinas treated with laser-induced choroidal neovascularization (CNV), bright white-light exposure, and Fam161a-associated inherited retinal degeneration. The assays can be applied to any of the existing mouse models for retinal disorders and may be valuable for documenting immune responses in studies for immunomodulatory therapies.
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15
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Peirson SN, Brown LA, Pothecary CA, Benson LA, Fisk AS. Light and the laboratory mouse. J Neurosci Methods 2017; 300:26-36. [PMID: 28414048 PMCID: PMC5909038 DOI: 10.1016/j.jneumeth.2017.04.007] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 02/06/2023]
Abstract
Light exerts widespread effects on physiology and behaviour. As well as the widely-appreciated role of light in vision, light also plays a critical role in many non-visual responses, including regulating circadian rhythms, sleep, pupil constriction, heart rate, hormone release and learning and memory. In mammals, responses to light are all mediated via retinal photoreceptors, including the classical rods and cones involved in vision as well as the recently identified melanopsin-expressing photoreceptive retinal ganglion cells (pRGCs). Understanding the effects of light on the laboratory mouse therefore depends upon an appreciation of the physiology of these retinal photoreceptors, including their differing sens itivities to absolute light levels and wavelengths. The signals from these photoreceptors are often integrated, with different responses involving distinct retinal projections, making generalisations challenging. Furthermore, many commonly used laboratory mouse strains carry mutations that affect visual or non-visual physiology, ranging from inherited retinal degeneration to genetic differences in sleep and circadian rhythms. Here we provide an overview of the visual and non-visual systems before discussing practical considerations for the use of light for researchers and animal facility staff working with laboratory mice.
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Affiliation(s)
- Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom.
| | - Laurence A Brown
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
| | - Carina A Pothecary
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
| | - Lindsay A Benson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
| | - Angus S Fisk
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
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16
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Lyzogubov VV, Bora PS, Wu X, Horn LE, de Roque R, Rudolf XV, Atkinson JP, Bora NS. The Complement Regulatory Protein CD46 Deficient Mouse Spontaneously Develops Dry-Type Age-Related Macular Degeneration-Like Phenotype. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2088-2104. [PMID: 27295359 PMCID: PMC4973660 DOI: 10.1016/j.ajpath.2016.03.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 03/28/2016] [Accepted: 03/31/2016] [Indexed: 11/20/2022]
Abstract
In the mouse, membrane cofactor protein (CD46), a key regulator of the alternative pathway of the complement system, is only expressed in the eye and on the inner acrosomal membrane of spermatozoa. We noted that although Cd46(-/-) mice have normal systemic alternative pathway activating ability, lack of CD46 leads to dysregulated complement activation in the eye, as evidenced by increased deposition of C5b-9 in the retinal pigment epithelium (RPE) and choroid. A knockout of CD46 induced the following cardinal features of human dry age-related macular degeneration (AMD) in 12-month-old male and female mice: accumulation of autofluorescent material in and hypertrophy of the RPE, dense deposits in and thickening of Bruch's membrane, loss of photoreceptors, cells in subretinal space, and a reduction of choroidal vessels. Collectively, our results demonstrate spontaneous age-related degenerative changes in the retina, RPE, and choroid of Cd46(-/-) mice that are consistent with human dry AMD. These findings provide the exciting possibility of using Cd46(-/-) mice as a convenient and reliable animal model for dry AMD. Having such a relatively straight-forward model for dry AMD should provide valuable insights into pathogenesis and a test model system for novel drug targets. More important, tissue-specific expression of CD46 gives the Cd46(-/-) mouse model of dry AMD a unique advantage over other mouse models using knockout strains.
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Affiliation(s)
- Valeriy V Lyzogubov
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Puran S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Xiaobo Wu
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Leah E Horn
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Ryan de Roque
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; University of Arkansas for Medical Sciences, College of Medicine, Little Rock, Arkansas
| | - Xeniya V Rudolf
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Nalini S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat and Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas; Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
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17
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Chrenek MA, Nickerson JM, Boatright JH. Clustered Regularly Interspaced Short Palindromic Repeats: Challenges in Treating Retinal Disease. Asia Pac J Ophthalmol (Phila) 2016; 5:304-8. [PMID: 27488072 PMCID: PMC4975549 DOI: 10.1097/apo.0000000000000225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Ophthalmic researchers and clinicians arguably have led the way for safe, effective gene therapy, most notably with adeno-associated viral gene supplementation in the treatment for patients with Leber congenital amaurosis type 2 with mutations in the RPE65 gene. These successes notwithstanding, most other genetic retinal disease will be refractory to supplementation. The ideal gene therapy approach would correct gene mutations to restore normal function in the affected cells. Gene editing in which a mutant allele is inactivated or converted to sequence that restores normal function is hypothetically one such approach. Such editing involves site-specific digestion of mutant genomic DNA followed by repair. Previous experimental approaches were hampered by inaccurate and high rates of off-site lesioning and by overall low digestion rates. A new tool, clustered regularly interspaced short palindromic repeats coupled with the nuclease Cas9, may address both shortcomings. Some of the many challenges that must be addressed in moving clustered regularly interspaced short palindromic repeats coupled with the nuclease Cas9 therapies to the ophthalmic clinic are discussed here.
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Affiliation(s)
- Micah A. Chrenek
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia
| | - John M. Nickerson
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia
| | - Jeffrey H. Boatright
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, Decatur, Georgia
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18
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Williams AM, Perkumas KM, Perry I, Wen JC, Keeling J, Tramber M, Liton PB, Stamer WD. Successful Implementation of a Program for Increasing Donor Eyes for Research: The Duke-Miracles In Sight Program. J Ocul Pharmacol Ther 2016; 32:145-9. [PMID: 26982653 PMCID: PMC4827310 DOI: 10.1089/jop.2015.0107] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/04/2015] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Although essential for development of ocular therapeutics, the quality and quantity of human donor eyes for research have been on the decline. To streamline procurement protocols, provide better medical documentation of tissue, and improve freshness and number of eyes, a pilot cooperative program was undertaken between the Duke University Eye Center and Miracles In Sight Eye Bank. METHODS For research eye donors who expire at Duke University Hospital, age restrictions to procurement were lifted, access to donors' electronic medical records was granted to researchers, and eye tissue was delivered directly to scientists. The number of eye pairs received per month and the time from death to arrival in the laboratory were documented, and independent-samples t-tests were used to compare the number of paired eyes and the death-to-laboratory time before and after implementation of the program. A cost analysis of the program was also conducted. RESULTS Implementation of the program decreased the time from death to arrival in the laboratory from an average of 22.1 ± 1.5 h (n = 22) to 11.6 ± 0.8 h (n = 75) for a pair of eyes (P < 0.0001). Moreover, the number of whole eye pairs increased from 1.57 ± 0.32 to 3.26 ± 0.27 donors per month (P = 0.0019). Cost analysis indicates that our program is financially viable and sustainable for the eye bank. CONCLUSIONS The Duke-Miracles In Sight Program implemented a number of operational changes that resulted in improved quantity and quality of ocular tissue to researchers. Such a model appears feasible for adoption between other eye centers and eye banks.
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Affiliation(s)
- Andrew M. Williams
- Michigan State University College of Human Medicine, Grand Rapids, Michigan
| | | | - Isaac Perry
- Miracles In Sight Eye Bank, Winston-Salem, North Carolina
| | - Joanne C. Wen
- Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Janet Keeling
- Miracles In Sight Eye Bank, Winston-Salem, North Carolina
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19
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Chang B. Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis. Methods Mol Biol 2016; 1438:417-430. [PMID: 27150101 DOI: 10.1007/978-1-4939-3661-8_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.
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Affiliation(s)
- Bo Chang
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
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20
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Soto F, Kerschensteiner D. Synaptic remodeling of neuronal circuits in early retinal degeneration. Front Cell Neurosci 2015; 9:395. [PMID: 26500497 PMCID: PMC4595653 DOI: 10.3389/fncel.2015.00395] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 09/22/2015] [Indexed: 11/27/2022] Open
Abstract
Photoreceptor degenerations are a major cause of blindness and among the most common forms of neurodegeneration in humans. Studies of mouse models revealed that synaptic dysfunction often precedes photoreceptor degeneration, and that abnormal synaptic input from photoreceptors to bipolar cells causes circuits in the inner retina to become hyperactive. Here, we provide a brief overview of frequently used mouse models of photoreceptor degenerations. We then discuss insights into circuit remodeling triggered by early synaptic dysfunction in the outer and hyperactivity in the inner retina. We discuss these insights in the context of other experimental manipulations of synaptic function and activity. Knowledge of the plasticity and early remodeling of retinal circuits will be critical for the design of successful vision rescue strategies.
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Affiliation(s)
- Florentina Soto
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis St. Louis, MO, USA
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis St. Louis, MO, USA ; Department of Anatomy and Neurobiology, Washington University School of Medicine in St. Louis St. Louis, MO, USA ; Department of Biomedical Engineering, Washington University School of Medicine in St. Louis St. Louis, MO, USA ; Hope Center for Neurological Disorders, Washington University School of Medicine in St. Louis St. Louis, MO, USA
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21
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Lyzogubov VV, Bora NS, Tytarenko RG, Bora PS. Polyethylene glycol induced mouse model of retinal degeneration. Exp Eye Res 2014; 127:143-52. [PMID: 25088354 DOI: 10.1016/j.exer.2014.07.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 07/15/2014] [Accepted: 07/23/2014] [Indexed: 12/31/2022]
Abstract
Age-related macular degeneration (AMD) is a leading cause of irreversible blindness. This study was done to characterize dry AMD-like changes in mouse retinal pigment epithelium (RPE) and retina after polyethylene glycol (PEG) treatment. We injected male C57BL/6 mice subretinally with PBS, 0.025, 0.25, 0.5 and 1.0 mg of PEG-400 and the animals were sacrificed on day 5. Eyes were harvested and processed for histological analysis. In all other experiments 0.5 mg PEG was injected and animals were sacrificed on days 1, 3, 5 or 14. Paraffin, 5 μm and plastic, 1 μm and 80 nm sections were used for further analysis. Subretinal injection of 0.5 mg PEG induced a 32% reduction of outer nuclear layer (ONL) thickness, 61% decrease of photoreceptor outer and inner segment length, 49% decrease of nuclear density in the ONL and 31% increase of RPE cell density by day 5 after injection. The maximum level of TUNEL positive nuclei in the ONL (6.8 + 1.99%) was detected at day 5 after PEG injection and co-localized with Casp3act. Histological signs of apoptosis were observed in the ONL by light or electron microscopy. Degeneration of RPE cells was found in PEG injected eyes. Gene expression data identified several genes reported to be involved in human AMD. C3, Cfi, Serping1, Mmp9, Htra1 and Lpl were up-regulated in PEG injected eyes compared to PBS controls. PEG leads to morphological and gene expression changes in RPE and retina consistent with dry AMD. This model will be useful to investigate dry AMD pathogenesis and treatment.
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Affiliation(s)
- Valeriy V Lyzogubov
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Nalini S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Ruslana G Tytarenko
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Puran S Bora
- Department of Ophthalmology, Jones Eye Institute, Pat & Willard Walker Eye Research Center, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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22
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Roosing S, Thiadens AAHJ, Hoyng CB, Klaver CCW, den Hollander AI, Cremers FPM. Causes and consequences of inherited cone disorders. Prog Retin Eye Res 2014; 42:1-26. [PMID: 24857951 DOI: 10.1016/j.preteyeres.2014.05.001] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 04/29/2014] [Accepted: 05/06/2014] [Indexed: 11/18/2022]
Abstract
Hereditary cone disorders (CDs) are characterized by defects of the cone photoreceptors or retinal pigment epithelium underlying the macula, and include achromatopsia (ACHM), cone dystrophy (COD), cone-rod dystrophy (CRD), color vision impairment, Stargardt disease (STGD) and other maculopathies. Forty-two genes have been implicated in non-syndromic inherited CDs. Mutations in the 5 genes implicated in ACHM explain ∼93% of the cases. On the contrary, only 21% of CRDs (17 genes) and 25% of CODs (8 genes) have been elucidated. The fact that the large majority of COD and CRD-associated genes are yet to be discovered hints towards the existence of unknown cone-specific or cone-sensitive processes. The ACHM-associated genes encode proteins that fulfill crucial roles in the cone phototransduction cascade, which is the most frequently compromised (10 genes) process in CDs. Another 7 CD-associated proteins are required for transport processes towards or through the connecting cilium. The remaining CD-associated proteins are involved in cell membrane morphogenesis and maintenance, synaptic transduction, and the retinoid cycle. Further novel genes are likely to be identified in the near future by combining large-scale DNA sequencing and transcriptomics technologies. For 31 of 42 CD-associated genes, mammalian models are available, 14 of which have successfully been used for gene augmentation studies. However, gene augmentation for CDs should ideally be developed in large mammalian models with cone-rich areas, which are currently available for only 11 CD genes. Future research will aim to elucidate the remaining causative genes, identify the molecular mechanisms of CD, and develop novel therapies aimed at preventing vision loss in individuals with CD in the future.
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Affiliation(s)
- Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | | | - Carel B Hoyng
- Department of Ophthalmology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Caroline C W Klaver
- Department of Ophthalmology Erasmus Medical Centre, 3000 CA, Rotterdam, The Netherlands; Department of Epidemiology, Erasmus Medical Centre, 3000 CA, Rotterdam, The Netherlands
| | - Anneke I den Hollander
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Nijmegen, PO Box 9101, 6500 HB, Nijmegen, The Netherlands.
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Abstract
We report on the functional optical coherence tomography (OCT) imaging of iris tissue morphology and microcirculation in living small animals. Anterior segments of healthy mouse and rat eyes are imaged with high-speed spectral domain OCT (SD-OCT) utilizing ultrahigh sensitive optical microangiography (UHS-OMAG) imaging protocol. 3D iris microvasculature is produced by the use of an algorithm that calculates absolute differences between the amplitudes of the OCT interframes. We demonstrate that the UHS-OMAG is capable of delineating iris microvascular beds in the mouse and rat with capillary-level resolution. Furthermore, the fast imaging speed enables dynamic imaging of iris micro-vascular response during drug-induced pupil dilation. We believe that this OCT angiographic approach has a great potential for in situ and in vivo monitoring of the microcirculation within iris tissue beds in rodent disease models that have microvascular involvement.
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Affiliation(s)
- Woo June Choi
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Zhongwei Zhi
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Ruikang K. Wang
- Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
- Department of Ophthalmology, University of Washington, Seattle, Washington 98195, USA
- Corresponding author:
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24
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Liegel RP, Ronchetti A, Sidjanin DJ. Alkylglycerone phosphate synthase (AGPS) deficient mice: models for rhizomelic chondrodysplasia punctate type 3 (RCDP3) malformation syndrome. Mol Genet Metab Rep 2014; 1:299-311. [PMID: 25197626 PMCID: PMC4151185 DOI: 10.1016/j.ymgmr.2014.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a genetically heterogeneous autosomal recessive syndrome characterized by congenital cataracts, shortening of the proximal limbs, neurological abnormalities, seizures, growth delays, and severe intellectual disability. Most RCDP children die in the first decade of life due to respiratory complications. Mutations in alkylglycerone phosphate synthase (AGPS) cause RCDP type 3 (RCDP3). We've previously established that cataracts and male infertility in blind sterile 2 (bs2) mice are caused by a spontaneous hypomorphic mutation in Agps. As a part of this study, we set out to further explore the bs2 phenotypes and how they correlate to the clinical presentations of RCDP3 patients. Our results show that ∼50% bs2 mice die embryonically and surviving bs2 mice exhibit growth delays that they overcome by adulthood. The X-ray analysis of adult bs2 mice revealed significant humeral, but not femoral shortening. Clinical and histological eye evaluations revealed that bs2 lenses undergo normal development with first opacities developing at P21 that by P28 rapidly progress to mature cataracts. Evaluation of testes determined that infertility in bs2 mice is due to the aberrant formation of multicellular cellular clusters that undergo apoptosis. Given that the bs2 locus is a hypomorphic Agps mutation, we set out to generate Agps knockout mice utilizing Knockout Mouse Project (KOMP) resource. Our results showed that ∼85% of Agps knock-out mice die embryonically whereas surviving adult Agps knock-out mice phenotypically exhibit cataracts and testicular abnormalities similar to those observed in bs2 mice. Given that the majority of Agps knock-out mice die embryonically presented a challenge for further analyses of Agps deficiency in mouse models. Although not done as a part of this study, Agps-KOMP mice or ES cells can be further modified with FLP recombinase to generate mice suitable for subsequent matings with a transgenic Cre strain of choice, thereby providing an opportunity to study conditional Agps deficiency in a specific tissue or desired developmental time points without Agps deficiency-mediated embryonic lethality.
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Affiliation(s)
- Ryan P Liegel
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI
| | - Adam Ronchetti
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI
| | - D J Sidjanin
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI ; Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI
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Garanto A, van Beersum SEC, Peters TA, Roepman R, Cremers FPM, Collin RWJ. Unexpected CEP290 mRNA splicing in a humanized knock-in mouse model for Leber congenital amaurosis. PLoS One 2013; 8:e79369. [PMID: 24223178 PMCID: PMC3819269 DOI: 10.1371/journal.pone.0079369] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 09/27/2013] [Indexed: 01/29/2023] Open
Abstract
Leber congenital amaurosis (LCA) is the most severe form of retinal dystrophy with an onset in the first year of life. The most frequent genetic cause of LCA, accounting for up to 15% of all LCA cases in Europe and North-America, is a mutation (c.2991+1655AG) in intron 26 of CEP290. This mutation generates a cryptic splice donor site resulting in the insertion of an aberrant exon (exon X) containing a premature stop codon to CEP290 mRNA. In order to study the pathophysiology of the intronic CEP290 mutation, we generated two humanized knock-in mouse models each carrying ~6.3 kb of the human CEP290 gene, either with or without the intronic mutation. Transcriptional characterization of these mouse models revealed an unexpected splice pattern of CEP290 mRNA, especially in the retina. In both models, a new cryptic exon (coined exon Y) was identified in ~5 to 12% of all Cep290 transcripts. This exon Y was expressed in all murine tissues analyzed but not detected in human retina or fibroblasts of LCA patients. In addition, exon x that is characteristic of LCA in humans, was expressed at only very low levels in the retina of the LCA mouse model. Western blot and immunohistochemical analyses did not reveal any differences between the two transgenic models and wild-type mice. Together, our results show clear differences in the recognition of splice sites between mice and humans, and emphasize that care is warranted when generating animal models for human genetic diseases caused by splice mutations.
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Affiliation(s)
- Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Sylvia E. C. van Beersum
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Theo A. Peters
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- Department of Otorhinolaryngology, Head and Neck Surgery, Radboud University Medical Centre, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Rob W. J. Collin
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
- Institute for Genetic and Metabolic Disease, Radboud University Medical Centre, Nijmegen, The Netherlands
- Nijmegen Centre for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
- * E-mail:
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Chang B, Hurd R, Wang J, Nishina P. Survey of common eye diseases in laboratory mouse strains. Invest Ophthalmol Vis Sci 2013; 54:4974-81. [PMID: 23800770 DOI: 10.1167/iovs.13-12289] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE As in human populations, in which founder mutations have been identified in groups of families, a number of founder mutations have been observed across strains in mice. In this report, we provide a phenotype and genotype survey of three common eye diseases in the collection of JAX mice strains at The Jackson Laboratory (JAX). These eye diseases are retinal degeneration 1 (Pde6b(rd1)), retinal degeneration 8 (Crb1(rd8)), and cone photoreceptor function loss 3 (Gnat2(cpfl3)). METHODS Ocular lesions for rd1 and rd8 were evaluated by fundus examination and fundus photography, and the abnormal retinal function observed in mice homozygous for cpfl3 was assessed by ERG. Genotyping protocols for rd1, rd8, and cpfl3 mutations were performed by PCR with appropriate primers. RESULTS We have actively screened retired breeders for surface dysmorphologies, and for intraocular defects by indirect ophthalmoscopy, slit-lamp biomicroscopy, and ERG to discover new spontaneous mutations in strains from the Genetic Resource Science (GRS) production colony. Through this process, we have found that of the strains screened, 99 strains carried the rd1 mutation, 85 strains carried the rd8 mutation, and 20 strains carried the cpfl3 mutation. CONCLUSIONS Of the 1000 of strains screened during this study, 204 carried one of three founder mutations in Pde6b, Crb1, or Gnat2. Since these three retinal mutations occur commonly in various mouse strains, genotyping for these mutations, and/or avoiding mouse strains or stocks carrying these mutant alleles when studying new retinal disorders is recommended. The robust PCR genotyping protocols to test for these common alleles are described herein.
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Affiliation(s)
- Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA.
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Song W, Wei Q, Feng L, Sarthy V, Jiao S, Liu X, Zhang HF. Multimodal photoacoustic ophthalmoscopy in mouse. JOURNAL OF BIOPHOTONICS 2013; 6:505-512. [PMID: 22649053 PMCID: PMC3986594 DOI: 10.1002/jbio.201200061] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 04/29/2012] [Accepted: 05/01/2012] [Indexed: 05/04/2023]
Abstract
Photoacoustic ophthalmoscopy (PAOM) is a novel imaging technology that measures optical absorption in the retina. The capability of PAOM can be further enhanced if it could image mouse eyes, because mouse models are widely used for various retinal diseases. The challenges in achieving high-quality imaging of mouse retina, however, come from the much smaller eyeball size. Here, we report an optimized imaging system, which integrates PAOM, spectral-domain optical coherence tomography (SD-OCT), and autofluorescence-scanning laser ophthalmoscopy (AF-SLO), for mouse eyes. Its multimodal capability was demonstrated by imaging transgenic Nrl-GFP mice that express green fluorescent protein (GFP) in photoreceptors. SD-OCT provided guidance of optical alignment for PAOM and AF-SLO, and complementary contrast with high depth-resolution retinal cross sections. PAOM visualized the retinal vasculature and retinal pigment epithelium melanin, and AF-SLO measured GFP-expressing in retinal photoreceptors. The in vivo imaging results were verified by histology and confocal microscopy.
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Affiliation(s)
- Wei Song
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Rd., Evanston IL 60208, USA
- Department of Physics, Harbin Institute of Technology, 92 West Da-Zhi Street Nangang District, Harbin, Heilongjiang, P.R. China 150080
| | - Qing Wei
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Rd., Evanston IL 60208, USA
| | - Liang Feng
- Department of Ophthalmology, Northwestern University, 645 North Michigan Ave., Chicago IL 60611, USA
| | - Vijay Sarthy
- Department of Ophthalmology, Northwestern University, 645 North Michigan Ave., Chicago IL 60611, USA
| | - Shuliang Jiao
- Department of Ophthalmology, University of Southern California, 1450 San Pablo Street, Los Angeles CA 90033, USA
| | - Xiaorong Liu
- Department of Ophthalmology, Northwestern University, 645 North Michigan Ave., Chicago IL 60611, USA
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, 2145 Sheridan Rd., Evanston IL 60208, USA
- Department of Ophthalmology, Northwestern University, 645 North Michigan Ave., Chicago IL 60611, USA
- Corresponding author: H.F. Zhang:
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Xia CH, Chang B, DeRosa AM, Cheng C, White TW, Gong X. Cataracts and microphthalmia caused by a Gja8 mutation in extracellular loop 2. PLoS One 2012; 7:e52894. [PMID: 23300808 PMCID: PMC3530494 DOI: 10.1371/journal.pone.0052894] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 11/21/2012] [Indexed: 11/18/2022] Open
Abstract
The mouse semi-dominant Nm2249 mutation displays variable cataracts in heterozygous mice and smaller lenses with severe cataracts in homozygous mice. This mutation is caused by a Gja8(R205G) point mutation in the second extracellular loop of the Cx50 (or α8 connexin) protein. Immunohistological data reveal that Cx50-R205G mutant proteins and endogenous wild-type Cx46 (or α3 connexin) proteins form diffuse tiny spots rather than typical punctate signals of normal gap junctions in the lens. The level of phosphorylated Cx46 proteins is decreased in Gja8(R205G/R205G) mutant lenses. Genetic analysis reveals that the Cx50-R205G mutation needs the presence of wild-type Cx46 to disrupt lens peripheral fibers and epithelial cells. Electrophysiological data in Xenopus oocytes reveal that Cx50-R205G mutant proteins block channel function of gap junctions composed of wild-type Cx50, but only affect the gating of wild-type Cx46 channels. Both genetic and electrophysiological results suggest that Cx50-R205G mutant proteins alone are unable to form functional channels. These findings imply that the Gja8(R205G) mutation differentially impairs the functions of Cx50 and Cx46 to cause cataracts, small lenses and microphthalmia. The Gja8(R205G) mutation occurs at the same conserved residue as the human GJA8(R198W) mutation. This work provides molecular insights to understand the cataract and microphthalmia/microcornea phenotype caused by Gja8 mutations in mice and humans.
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Affiliation(s)
- Chun-hong Xia
- School of Optometry and Vision Science Program, University of California, Berkeley, California, United States of America
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Adam M. DeRosa
- Physiology and Biophysics, State University of New York – Stony Brook, Stony Brook, New York, United States of America
| | - Catherine Cheng
- School of Optometry and Vision Science Program, University of California, Berkeley, California, United States of America
| | - Thomas W. White
- Physiology and Biophysics, State University of New York – Stony Brook, Stony Brook, New York, United States of America
| | - Xiaohua Gong
- School of Optometry and Vision Science Program, University of California, Berkeley, California, United States of America
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Seiler MJ, Aramant RB. Cell replacement and visual restoration by retinal sheet transplants. Prog Retin Eye Res 2012; 31:661-87. [PMID: 22771454 PMCID: PMC3472113 DOI: 10.1016/j.preteyeres.2012.06.003] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 06/19/2012] [Accepted: 06/23/2012] [Indexed: 12/18/2022]
Abstract
Retinal diseases such as age-related macular degeneration (ARMD) and retinitis pigmentosa (RP) affect millions of people. Replacing lost cells with new cells that connect with the still functional part of the host retina might repair a degenerating retina and restore eyesight to an unknown extent. A unique model, subretinal transplantation of freshly dissected sheets of fetal-derived retinal progenitor cells, combined with its retinal pigment epithelium (RPE), has demonstrated successful results in both animals and humans. Most other approaches are restricted to rescue endogenous retinal cells of the recipient in earlier disease stages by a 'nursing' role of the implanted cells and are not aimed at neural retinal cell replacement. Sheet transplants restore lost visual responses in several retinal degeneration models in the superior colliculus (SC) corresponding to the location of the transplant in the retina. They do not simply preserve visual performance - they increase visual responsiveness to light. Restoration of visual responses in the SC can be directly traced to neural cells in the transplant, demonstrating that synaptic connections between transplant and host contribute to the visual improvement. Transplant processes invade the inner plexiform layer of the host retina and form synapses with presumable host cells. In a Phase II trial of RP and ARMD patients, transplants of retina together with its RPE improved visual acuity. In summary, retinal progenitor sheet transplantation provides an excellent model to answer questions about how to repair and restore function of a degenerating retina. Supply of fetal donor tissue will always be limited but the model can set a standard and provide an informative base for optimal cell replacement therapies such as embryonic stem cell (ESC)-derived therapy.
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Affiliation(s)
- Magdalene J Seiler
- Department of Anatomy & Neurobiology, Reeve-Irvine Research Center, Sue & Bill Gross Stem Cell Research Center, University of California at Irvine, 1101 Gross Hall, 845 Health Science Rd., Irvine, CA 92697-4265, USA.
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Kuhrt H, Gryga M, Wolburg H, Joffe B, Grosche J, Reichenbach A, Noori HR. Postnatal mammalian retinal development: quantitative data and general rules. Prog Retin Eye Res 2012; 31:605-21. [PMID: 22982602 DOI: 10.1016/j.preteyeres.2012.08.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 08/07/2012] [Accepted: 08/08/2012] [Indexed: 10/27/2022]
Abstract
This article is aimed at providing comparative quantitative data about postnatal mammalian retina development, and at searching for some general rules at both the descriptive and the mechanistic level. In mammals the eye continues to grow, and the retina continues to expand, much after the end of retinal cytogenesis. Thus, although the total number of retinal cells remains constant after cessation of mitotic activity (and the end of 'physiological cell death'), the retinal surface area increases by a factor of two or more. In most mammals, ocular growth exceeds retinal expansion: the neural retina lines 70-80% of the inner ocular surface at the beginning but only about 40-60% in adults. Differential local expansion of the retina (the peripheral area increases more than the central one) can be explained by 'passive stretching' of the retinal tissue by the growing eyeball; it depends on the different biomechanical properties of the peripheral vs. central retinal tissue. The increasing retinal surface area allows for a re-distribution of cells such that the thickness of the (particularly, outer) nuclear layer(s) decreases proportional to the areal expansion. This causes a considerable developmental reduction of the number of cell nuclei 'stacked above each other' by a factor of more than two, and requires a translocation of the somata against their neighbors. We provide a physico-mathematical model of these oblique 'down-sliding' movements of the photoreceptor cell somata along the Müller cell process in the center of their columnar cell unit.
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Affiliation(s)
- Heidrun Kuhrt
- Paul Flechsig Institute of Brain Research, University of Leipzig, D-04109 Leipzig, Germany
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Geng Y, Dubra A, Yin L, Merigan WH, Sharma R, Libby RT, Williams DR. Adaptive optics retinal imaging in the living mouse eye. BIOMEDICAL OPTICS EXPRESS 2012; 3:715-34. [PMID: 22574260 PMCID: PMC3345801 DOI: 10.1364/boe.3.000715] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 02/13/2012] [Accepted: 02/14/2012] [Indexed: 05/18/2023]
Abstract
Correction of the eye's monochromatic aberrations using adaptive optics (AO) can improve the resolution of in vivo mouse retinal images [Biss et al., Opt. Lett. 32(6), 659 (2007) and Alt et al., Proc. SPIE 7550, 755019 (2010)], but previous attempts have been limited by poor spot quality in the Shack-Hartmann wavefront sensor (SHWS). Recent advances in mouse eye wavefront sensing using an adjustable focus beacon with an annular beam profile have improved the wavefront sensor spot quality [Geng et al., Biomed. Opt. Express 2(4), 717 (2011)], and we have incorporated them into a fluorescence adaptive optics scanning laser ophthalmoscope (AOSLO). The performance of the instrument was tested on the living mouse eye, and images of multiple retinal structures, including the photoreceptor mosaic, nerve fiber bundles, fine capillaries and fluorescently labeled ganglion cells were obtained. The in vivo transverse and axial resolutions of the fluorescence channel of the AOSLO were estimated from the full width half maximum (FWHM) of the line and point spread functions (LSF and PSF), and were found to be better than 0.79 μm ± 0.03 μm (STD)(45% wider than the diffraction limit) and 10.8 μm ± 0.7 μm (STD)(two times the diffraction limit), respectively. The axial positional accuracy was estimated to be 0.36 μm. This resolution and positional accuracy has allowed us to classify many ganglion cell types, such as bistratified ganglion cells, in vivo.
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Affiliation(s)
- Ying Geng
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- The Institute of Optics, University of Rochester, Rochester, NY 14620, USA
| | - Alfredo Dubra
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14642, USA
- Current address: Eye Institute, Medical College of Wisconsin, WI 53226, USA
| | - Lu Yin
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
| | - William H. Merigan
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14642, USA
| | - Robin Sharma
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- The Institute of Optics, University of Rochester, Rochester, NY 14620, USA
| | - Richard T. Libby
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14642, USA
| | - David R. Williams
- Center for Visual Science, University of Rochester, Rochester, NY 14627, USA
- The Institute of Optics, University of Rochester, Rochester, NY 14620, USA
- Flaum Eye Institute, University of Rochester, Rochester, NY 14642, USA
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Abstract
Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human retinal degeneration. Mutant mice also provide reproducible, experimental systems for elucidating pathways of normal development and function. Here, I describe the tools used in the discoveries of many retinal degeneration models, including indirect ophthalmoscopy (to look at the fundus appearance), fundus photography and fluorescein angiography (to document the fundus appearance), electroretinography (to check retinal function), as well as the heritability test (for genetic characterization).
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Affiliation(s)
- Bo Chang
- The Jackson Laboratory, Bar Harbor, ME, USA,
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Merath KM, Chang B, Dubielzig R, Jeannotte R, Sidjanin DJ. A spontaneous mutation in Srebf2 leads to cataracts and persistent skin wounds in the lens opacity 13 (lop13) mouse. Mamm Genome 2011; 22:661-73. [PMID: 21858719 PMCID: PMC3251904 DOI: 10.1007/s00335-011-9354-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Accepted: 08/01/2011] [Indexed: 01/19/2023]
Abstract
Lens opacity 13 (lop13) is a spontaneous, autosomal recessive mouse mutant that exhibits nuclear cataracts. Histological analysis revealed swollen lens fiber cells and the presence of bladder cells within the lens cortex, as well as morgagnian globules and liquefied material at the lens posterior. At 3 months of age, in addition to cataracts, lop13 mice also develop persistent skin wounds. Linkage analysis assigned the lop13 locus to a 1.1-Mb region on mouse Chr 15, encompassing 19 candidate genes. Sequence analysis identified a C3112T mutation in exon 18 of Sterol Regulatory Element Binding-Transcription Factor 2 (Srebf2) resulting in the R1038C substitution of a highly conserved arginine within the Srebf2 regulatory domain. Srebf2 belongs to a family of membrane-bound basic helix-loop-helix leucine zipper transcription factors that control the expression of genes involved in the biosynthesis and uptake of cholesterol and fatty acids. The lack of complementation observed in Srebf2 ( lop13/GT ) compound heterozygotes carrying the Srebf2 gene trapped allele (Srebf2 ( GT )) provides genetic evidence that the identified C3112T substitution in Srebf2 is responsible for the lop13 phenotype. Gas chromatography analysis identified lower levels of cholesterol in the lop13 brain, liver, and lens when compared to wild-type mice. These findings suggest that lop13 is a hypomorphic mutation in Srebf2. As such, the lop13 mouse presents an invaluable in vivo model for studying the contribution of Srebf2 and cholesterol to maintaining the homeostasis of the lens and skin.
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Affiliation(s)
- Kate M. Merath
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Richard Dubielzig
- School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Richard Jeannotte
- Kansas Lipidomics Research Center, Kansas State University, Manhattan, KS 66506, USA
| | - Duska J. Sidjanin
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Congenital stationary night blindness in mice - a tale of two Cacna1f mutants. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 664:549-58. [PMID: 20238058 DOI: 10.1007/978-1-4419-1399-9_63] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Mutations in CACNA1F, which encodes the Ca(v)1.4 subunit of a voltage-gated L-type calcium channel, cause X-linked incomplete congenital stationary night blindness (CSNB2), a condition of defective retinal neurotransmission which results in night blindness, reduced visual acuity, and diminished ERG b-wave. We have characterized two putative murine CSNB2 models: an engineered null-mutant, with a stop codon (G305X); and a spontaneous mutant with an ETn insertion in intron 2 of Cacna1f (nob2). METHODS Cacna1f ( G305X ): Adults were characterized by visual function (photopic optokinetic response, OKR); gene expression (microarray) and by cell death (TUNEL) and synaptic development (TEM). Cacna1f ( nob2 ): Adults were characterized by properties of Cacna1f mRNA (cloning and sequencing) and expressed protein (immunoblotting, electrophysiology, filamin [cytoskeletal protein] binding), and OKR. RESULTS The null mutation in Cacna1f ( G305X ) mice caused loss of cone cell ribbons, failure of OPL synaptogenesis, ERG b-wave and absence of OKR. In Cacna1f ( nob2 ) mice alternative ETn splicing produced ~90% Cacna1f mRNA having a stop codon, but ~10% mRNA encoding a complete polypeptide. Cacna1f ( nob2 ) mice had normal OKR, and alternatively-spliced complete protein had WT channel properties, but alternative ETn splicing abolished N-terminal protein binding to filamin. CONCLUSIONS Ca(v)1.4 plays a key role in photoreceptor synaptogenesis and synaptic function in mouse retina. Cacna1f ( G305X ) is a true knockout model for human CSNB2, with prominent defects in cone and rod function. Cacna1f ( nob2 ) is an incomplete knockout model for CSNB2, because alternative splicing in an ETn element leads to some full-length Ca(v)1.4 protein, and some cones surviving to drive photopic visual responses.
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Liegel R, Chang B, Dubielzig R, Sidjanin D. Blind sterile 2 (bs2), a hypomorphic mutation in Agps, results in cataracts and male sterility in mice. Mol Genet Metab 2011; 103:51-9. [PMID: 21353609 PMCID: PMC3081956 DOI: 10.1016/j.ymgme.2011.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 02/03/2011] [Indexed: 11/22/2022]
Abstract
Blind sterile 2 (bs2) is a spontaneous autosomal recessive mouse mutation exhibiting cataracts and male sterility. Detailed clinical and histological evaluation revealed that bs2 mice have cataracts resulting from severely disrupted lens fiber cells. Analysis of bs2 testes revealed the absence of mature sperm and the presence of large multinucleate cells within the lumens of seminiferous tubules. Linkage analysis mapped the bs2 locus to mouse chromosome 2, approximately 45cM distal from the centromere. Fine mapping established a 3.1Mb bs2 critical region containing 19 candidate genes. Sequence analysis of alkylglycerone-phosphate synthase (Agps), a gene within the bs2 critical region, revealed a G to A substitution at the +5 position of intron 14. This mutation results in two abundantly expressed aberrantly spliced Agps transcripts: Agps(∆exon14) lacking exon 14 or Agps(exon∆13-14) lacking both exons 13 and 14 as well as full-length Agps transcript. Agps is a peroxisomal enzyme which catalyzes the formation of the ether bond during the synthesis of ether lipids. Both aberrantly spliced Agps(∆exon14) and Agps(exon∆13-14) transcripts led to a frame shift, premature stop and putative proteins lacking the enzymatic FAD domain. We present evidence that bs2 mice have significantly decreased levels of ether lipids. Human mutations in Agps result in rhizomelic chondrodysplasia punctata type 3 (RCDP3), a disease for which bs2 is the only genetic model. Thus, bs2 is a hypomorphic mutation in Agps, and represents a useful model for investigation of the tissue specificity of ether lipid requirements which will be particularly valuable for elucidating the mechanism of disease phenotypes resulting from ether lipid depletion.
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Affiliation(s)
- R. Liegel
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - B. Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - R. Dubielzig
- School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - D.J. Sidjanin
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
- Corresponding author: D.J. Sidjanin, Department of Cell Biology, Neurobiology, and Anatomy, Human and Molecular Genetics Center, Medical College of Wisconsin, Milwaukee, WI 53226, , Phone: 414-456-7810, Fax: 414-456-6516
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den Hollander AI, Black A, Bennett J, Cremers FPM. Lighting a candle in the dark: advances in genetics and gene therapy of recessive retinal dystrophies. J Clin Invest 2010; 120:3042-53. [PMID: 20811160 DOI: 10.1172/jci42258] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Nonsyndromic recessive retinal dystrophies cause severe visual impairment due to the death of photoreceptor and retinal pigment epithelium cells. These diseases until recently have been considered to be incurable. Molecular genetic studies in the last two decades have revealed the underlying molecular causes in approximately two-thirds of patients. The mammalian eye has been at the forefront of therapeutic trials based on gene augmentation in humans with an early-onset nonsyndromic recessive retinal dystrophy due to mutations in the retinal pigment epithelium-specific protein 65kDa (RPE65) gene. Tremendous challenges still lie ahead to extrapolate these studies to other retinal disease-causing genes, as human gene augmentation studies require testing in animal models for each individual gene and sufficiently large patient cohorts for clinical trials remain to be identified through cost-effective mutation screening protocols.
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Affiliation(s)
- Anneke I den Hollander
- Department of Ophthalmology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands
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Loss of lysophosphatidylcholine acyltransferase 1 leads to photoreceptor degeneration in rd11 mice. Proc Natl Acad Sci U S A 2010; 107:15523-8. [PMID: 20713727 DOI: 10.1073/pnas.1002897107] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Retinal degenerative diseases, such as retinitis pigmentosa and Leber congenital amaurosis, are a leading cause of untreatable blindness with substantive impact on the quality of life of affected individuals and their families. Mouse mutants with retinal dystrophies have provided a valuable resource to discover human disease genes and helped uncover pathways critical for photoreceptor function. Here we show that the rd11 mouse mutant and its allelic strain, B6-JR2845, exhibit rapid photoreceptor dysfunction, followed by degeneration of both rods and cones. Using linkage analysis, we mapped the rd11 locus to mouse chromosome 13. We then identified a one-nucleotide insertion (c.420-421insG) in exon 3 of the Lpcat1 gene. Subsequent screening of this gene in the B6-JR2845 strain revealed a seven-nucleotide deletion (c.14-20delGCCGCGG) in exon 1. Both sequence changes are predicted to result in a frame-shift, leading to premature truncation of the lysophosphatidylcholine acyltransferase-1 (LPCAT1) protein. LPCAT1 (also called AYTL2) is a phospholipid biosynthesis/remodeling enzyme that facilitates the conversion of palmitoyl-lysophosphatidylcholine to dipalmitoylphosphatidylcholine (DPPC). The analysis of retinal lipids from rd11 and B6-JR2845 mice showed substantially reduced DPPC levels compared with C57BL/6J control mice, suggesting a causal link to photoreceptor dysfunction. A follow-up screening of LPCAT1 in retinitis pigmentosa and Leber congenital amaurosis patients did not reveal any obvious disease-causing mutations. Previously, LPCAT1 has been suggested to be critical for the production of lung surfactant phospholipids and biosynthesis of platelet-activating factor in noninflammatory remodeling pathway. Our studies add another dimension to an essential role for LPCAT1 in retinal photoreceptor homeostasis.
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Xie B, Nakanishi S, Guo Q, Xia F, Yan G, An J, Li L, Serikawa T, Kuramoto T, Zhang Z. A novel middle-wavelength opsin (M-opsin) null-mutation in the retinal cone dysfunction rat. Exp Eye Res 2010; 91:26-33. [DOI: 10.1016/j.exer.2010.03.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 03/25/2010] [Accepted: 03/29/2010] [Indexed: 11/29/2022]
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Karlstetter M, Ebert S, Langmann T. Microglia in the healthy and degenerating retina: insights from novel mouse models. Immunobiology 2010; 215:685-91. [PMID: 20573418 DOI: 10.1016/j.imbio.2010.05.010] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 05/20/2010] [Indexed: 12/24/2022]
Abstract
In contrast to the tremendous amount of research data from the central nervous system, relatively little is known about microglial homeostasis in the retina. This may be explained by a strong research bias towards important brain pathologies including Alzheimer's disease, Parkinson's disease, and Multiple Sclerosis. In addition, there are specific technical limitations which hampered the analysis of retinal microglia, including their relatively small number in ocular tissue. The lack of experimental tools also prevented direct visualization and molecular analysis of this specialized neuronal macrophage population. Over the last few years, this situation has changed considerably as more and more retinal disorders have come into focus. Many rare monogenic forms as well as more prevalent complex disorders, in particular the age-related macular degeneration involves innate immune mechanisms. As a consequence, new genetic and experimental mouse models have been developed that mimic various forms of human retinal degeneration. In conjunction with these disease models, novel macrophage/microglia-specific reporter mice were established that allow the monitoring of retinal microglia in situ and in vivo. This review summarizes recent findings from these mouse models and thereby provides an overview of microglial homeostasis in the healthy and degenerating retina. Based on this knowledge, microglia-targeted therapies are envisioned which could delay or attenuate degenerative retinal disease.
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Affiliation(s)
- Marcus Karlstetter
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
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Budzynski E, Gross AK, McAlear SD, Peachey NS, Shukla M, He F, Edwards M, Won J, Hicks WL, Wensel TG, Naggert JK, Nishina PM. Mutations of the opsin gene (Y102H and I307N) lead to light-induced degeneration of photoreceptors and constitutive activation of phototransduction in mice. J Biol Chem 2010; 285:14521-33. [PMID: 20207741 DOI: 10.1074/jbc.m110.112409] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the Rhodopsin (Rho) gene can lead to autosomal dominant retinitis pigmentosa (RP) in humans. Transgenic mouse models with mutations in Rho have been developed to study the disease. However, it is difficult to know the source of the photoreceptor (PR) degeneration in these transgenic models because overexpression of wild type (WT) Rho alone can lead to PR degeneration. Here, we report two chemically mutagenized mouse models carrying point mutations in Rho (Tvrm1 with an Y102H mutation and Tvrm4 with an I307N mutation). Both mutants express normal levels of rhodopsin that localize to the PR outer segments and do not exhibit PR degeneration when raised in ambient mouse room lighting; however, severe PR degeneration is observed after short exposures to bright light. Both mutations also cause a delay in recovery following bleaching. This defect might be due to a slower rate of chromophore binding by the mutant opsins compared with the WT form, and an increased rate of transducin activation by the unbound mutant opsins, which leads to a constitutive activation of the phototransduction cascade as revealed by in vitro biochemical assays. The mutant-free opsins produced by the respective mutant Rho genes appear to be more toxic to PRs, as Tvrm1 and Tvrm4 mutants lacking the 11-cis chromophore degenerate faster than mice expressing WT opsin that also lack the chromophore. Because of their phenotypic similarity to humans with B1 Rho mutations, these mutants will be important tools in examining mechanisms underlying Rho-induced RP and for testing therapeutic strategies.
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Affiliation(s)
- Ewa Budzynski
- The Jackson Laboratory, Bar Harbor, Maine 04609, USA
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Ramkumar HL, Zhang J, Chan CC. Retinal ultrastructure of murine models of dry age-related macular degeneration (AMD). Prog Retin Eye Res 2010; 29:169-90. [PMID: 20206286 DOI: 10.1016/j.preteyeres.2010.02.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness worldwide in the elderly population. The pathology of dry AMD consists of macular degeneration of photoreceptors and the RPE, lipofuscin (A2E) accumulation, and drusen formation. Mice have been widely used for generating models that simulate human AMD features for investigating the pathogenesis, treatment and prevention of the disease. Although the mouse has no macula, focal atrophy of photoreceptors and RPE, lipofuscin accumulation, and increased A2E can develop in aged mouse eyes. However, drusen are rarely seen in mice because of their simpler Bruch's membrane and different process of lipofuscin extrusion compared with humans. Thus, analyzing basal deposits at the ultrastructural level and understanding the ultrastructural pathologic differences between various mouse AMD models are critical to comprehending the significance of research findings and response to possible therapeutic options for dry AMD. Based on the multifactorial pathogenesis of AMD, murine dry AMD models can be classified into three groups. First, genetically engineered mice that target genes related to juvenile macular dystrophies are the most common models, and they include abcr(-/-) (Stargardt disease), transgenic ELOVL4 (Stargardt-3 dominant inheritary disease), Efemp1(R345W/R345W) (Doyne honeycomb retinal dystrophy), and Timp3(S156C/S156C) (Sorsby fundus dystrophy) mice. Other murine models target genes relevant to AMD, including inflammatory genes such as Cfh(-/-), Ccl2(-/-), Ccr2(-/-), Cx3cr1(-/-), and Ccl2(-/-)/cx3cr1(-/-), oxidative stress associated genes such as Sod1(-/-) and Sod2 knockdown, metabolic pathway genes such as neprilysin(-/-) (amyloid beta), transgenic mcd/mcd (cathepsin D), Cp(-/-)/Heph(-/Y) (ferroxidase ceruloplasmin/hepaestin, iron metabolism), and transgenic ApoE4 on high fat and high cholesterol diet (lipid metabolism). Second, mice have also been immunologically manipulated by immunization with carboxyethylpyrrole (CEP), an oxidative fragment of DHA found in drusen, and found to present with dry AMD features. Third, natural mouse strains such as arrd2/arrd2 (Mdm gene mutation) and the senescence accelerated mice (SAM) spontaneously develop features of dry AMD like photoreceptor atrophy and thickening of Bruch's membrane. All the aforementioned models develop retinal lesions with various features that simulate dry AMD lesions: focal photoreceptor degeneration, abnormal RPE with increased lipofuscin, basal infolding, decreased melanosomes and degeneration. However, Bruch's membrane changes are less common. Most mice develop retinal lesions at an older age (6-24 months, depending on the models), while the Ccl2(-/-)/cx3cr1(-/-) mice develop lesions by 4-6 weeks. Although murine models present various degrees of retinal and/or RPE degeneration, classical drusen is extremely rare. Using electron microscopy, small drusenoid deposits are found between RPE and Bruch's membrane in a few models including Efemp1(R345W/R345W), Ccl2(-/-)/cx3cr1(-/-), neprilysin(-/-), transgenic mcd/mcd, and ApoE4 transgenic mice on a high fat diet. High A2E levels are measured in the retinas of abcr(-/-), transgenic ELOVL4, and Ccl2(-/-)/cx3cr1(-/-) mice. In summary, murine models provide useful tools for studying AMD pathogenesis and evaluating novel therapies for this disease. This review compares the major dry AMD murine models and discusses retinal pathology at the ultrastructural level.
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Affiliation(s)
- Hema L Ramkumar
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892-1857, USA
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42
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Abstract
The waved with open eyes (woe) locus is a spontaneous recessive mouse mutation that exhibits wavy fur, eyelids open at birth, and enlarged heart and esophagus. In this study, we confirmed the previously identified woe phenotypes and additionally identified anterior eye segment defects, absence of the meibomian glands, and defects in the semilunar cardiac valves. Positional cloning identified a C794T substitution in the Adam17 gene that ablates a putative exonic splicing enhancer (ESE) sequence in exon 7 resulting in aberrant Adam17 splicing. The predominant woe transcript, Adam17(Delta)(exon7), lacks exon 7 resulting in an in-frame deletion of 90 bp and a putative Adam17(Delta252-281) protein lacking residues 252-281 from the metalloprotease domain. Western blot analysis in woe identified only the precursor form of Adam17(Delta252-281) protein. Absence of cleavage of the prodomain renders Adam17(Delta252-281) functionally inactive; however, constitutive and stimulated shedding of Adam17 substrates was detected in woe at significantly reduced levels. This residual Adam17 shedding activity in woe most likely originates from full-length Adam17(T265M) encoded by the Adam17(C794T) transcript identified expressed at severely reduced levels. These results show that even small amounts of functional Adam17 allow woe mice to survive into adulthood. In contrast to Adam17(-/-) mice that die at birth, the viability of woe mice provides an excellent opportunity for studying the role of Adam17 throughout postnatal development and homeostasis.
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Miyamoto M, Aoki M, Sugimoto S, Kawasaki K, Imai R. IRD1 and IRD2 Mice, Naturally Occurring Models of Hereditary Retinal Dysfunction, Show Late-Onset and Progressive Retinal Degeneration. Curr Eye Res 2010; 35:137-45. [DOI: 10.3109/02713680903447900] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Becker D, Tetens J, Brunner A, Bürstel D, Ganter M, Kijas J, Drögemüller C. Microphthalmia in Texel sheep is associated with a missense mutation in the paired-like homeodomain 3 (PITX3) gene. PLoS One 2010; 5:e8689. [PMID: 20084168 PMCID: PMC2805710 DOI: 10.1371/journal.pone.0008689] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 12/14/2009] [Indexed: 12/16/2022] Open
Abstract
Microphthalmia in sheep is an autosomal recessive inherited congenital anomaly found within the Texel breed. It is characterized by extremely small or absent eyes and affected lambs are absolutely blind. For the first time, we use a genome-wide ovine SNP array for positional cloning of a Mendelian trait in sheep. Genotyping 23 cases and 23 controls using Illumina's OvineSNP50 BeadChip allowed us to localize the causative mutation for microphthalmia to a 2.4 Mb interval on sheep chromosome 22 by association and homozygosity mapping. The PITX3 gene is located within this interval and encodes a homeodomain-containing transcription factor involved in vertebrate lens formation. An abnormal development of the lens vesicle was shown to be the primary event in ovine microphthalmia. Therefore, we considered PITX3 a positional and functional candidate gene. An ovine BAC clone was sequenced, and after full-length cDNA cloning the PITX3 gene was annotated. Here we show that the ovine microphthalmia phenotype is perfectly associated with a missense mutation (c.338G>C, p.R113P) in the evolutionary conserved homeodomain of PITX3. Selection against this candidate causative mutation can now be used to eliminate microphthalmia from Texel sheep in production systems. Furthermore, the identification of a naturally occurring PITX3 mutation offers the opportunity to use the Texel as a genetically characterized large animal model for human microphthalmia.
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Affiliation(s)
- Doreen Becker
- Institute of Genetics, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Jens Tetens
- Institute for Animal Breeding and Husbandry, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Adrian Brunner
- Institute of Genetics, Vetsuisse Faculty, University of Berne, Berne, Switzerland
| | - Daniela Bürstel
- Clinic for Pigs and Small Ruminants, Forensic Medicine and Ambulatory Service Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Martin Ganter
- Clinic for Pigs and Small Ruminants, Forensic Medicine and Ambulatory Service Small Animals, University of Veterinary Medicine Hannover, Hannover, Germany
| | - James Kijas
- Commonwealth Scientific and Industrial Research Organisation Livestock Industries, St Lucia, Brisbane, Queensland, Australia
| | | | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Berne, Berne, Switzerland
- * E-mail:
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Mao M, Thedens DR, Chang B, Harris BS, Zheng QY, Johnson KR, Donahue LR, Anderson MG. The podosomal-adaptor protein SH3PXD2B is essential for normal postnatal development. Mamm Genome 2009; 20:462-75. [PMID: 19669234 DOI: 10.1007/s00335-009-9210-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 07/10/2009] [Indexed: 01/07/2023]
Abstract
Podosome-type adhesions are actin-based membrane protrusions involved in cell-matrix adhesion and extracellular matrix degradation. Despite growing knowledge of many proteins associated with podosome-type adhesions, much remains unknown concerning the function of podosomal proteins at the level of the whole animal. In this study, the spontaneous mouse mutant nee was used to identify a component of podosome-type adhesions that is essential for normal postnatal growth and development. Mice homozygous for the nee allele exhibited runted growth, craniofacial and skeletal abnormalities, ocular anterior segment dysgenesis, and hearing impairment. Adults also exhibited infertility and a form of lipodystrophy. Using genetic mapping and DNA sequencing, the cause of nee phenotypes was identified as a 1-bp deletion within the Sh3pxd2b gene on mouse Chromosome 11. Whereas the wild-type Sh3pxd2b gene is predicted to encode a protein with one PX domain and four SH3 domains, the nee mutation is predicted to cause a frameshift and a protein truncation altering a portion of the third SH3 domain and deleting all of the fourth SH3 domain. The SH3PXD2B protein is believed to be an important component of podosomes likely to mediate protein-protein interactions with membrane-spanning metalloproteinases. Testing this directly, SH3PXD2B localized to podosomes in constitutively active Src-transfected fibroblasts and through its last SH3 domain associated with a transmembrane member of a disintegrin and metalloproteinase family of proteins, ADAM15. These results identify SH3PXD2B as a podosomal-adaptor protein required for postnatal growth and development, particularly within physiologic contexts involving extracellular matrix regulation.
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Affiliation(s)
- Mao Mao
- Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, IA 52242, USA
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Abstract
PURPOSE Pupillometry is used as a phenotyping assay for investigating pupil responses in normal and genetically engineered mice. The mice used most often in contemporary ophthalmic research have not been adequately investigated by pupillometry. METHODS An infrared-video camera was used to assess pupillary functioning under standard dark-adapted conditions (30 min acclimatization in a ganzfeld chamber) and 30 min after the installation of either 10 microl tropicamide (1.0%) or 10 microl pilocarpine (5.0%) into the conjunctival cul-de-sac. The experiment was self-controlled using a repeated-measures analysis of variance to analyze 60 mice (30 males, 24 weeks of age) from three strains (C57BL/6, 129SvJ, and F1 hybrid). RESULTS The dark-adapted pupillary diameter of mice ranged from 2.3 mm (SD = 0.14) in female C57BL/6 to 2.9 mm (SD = 0.05) in male 129SvJ. Under dark-adapted conditions, all mice examined were sexual dimorphic (F = 19.5, dF = 2, 119, p < 0.001) and strain-dependent differences were observed between male C57BL/6-129SvJ and C57BL/6-F1 and female C57BL/6-F1 (F = 82.32, dF = 1, 119, p < 0.001). The mean pupillary diameter 30 min after the application of tropicamide ranged from 2.5 mm (SD = 0.16) in female F1 to 3.0 mm (SD = 0.13) in male C57BL/6. Tropicamide produced a sexual dimorphism in mydriasis for all mice (F = 56.30, dF = 1, 59, p < 0.001); however, strain-dependent differences were not observed (F = 1.31, dF = 2, 59, p < 0.280). The mean pupillary diameter 30 min after the application of pilocarpine ranged from 2.6 mm (SD = 0.28) in female C57BL/6 to 3.2 mm in both male F1 (SD = 0.22) and 129SvJ (SD = 0.04). Pilocarpine produced a sexual dimorphism in mydriasis for 129SvJ and F1 (F = 106.70, dF = 1, 59, p < 0.001) and strain-dependent differences were observed between female C57BL/6-F1 (F = 17.25, dF = 2, 59, p < 0.001). CONCLUSIONS The experiment demonstrates that mice respond idiosyncratically in their pupillary response under standard dark-adapted conditions and to either tropicamide or pilocarpine depending on strain and/or sex of the mouse. The characteristic responses observed are likely due to subtle differences in the genetic expression of phenotype.
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Naturally occurring animal models with outer retina phenotypes. Vision Res 2009; 49:2636-52. [PMID: 19375447 DOI: 10.1016/j.visres.2009.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 04/07/2009] [Accepted: 04/07/2009] [Indexed: 01/28/2023]
Abstract
Naturally occurring and laboratory generated animal models serve as powerful tools with which to investigate the etiology of human retinal degenerations, especially retinitis pigmentosa (RP), Leber congenital amaurosis (LCA), cone dystrophies (CD) and macular degeneration (MD). Much progress has been made in elucidating gene defects underlying disease, in understanding mechanisms leading to disease, and in designing molecules for translational research and gene-based therapy to interfere with the progression of disease. Key to this progress has been study of naturally occurring murine and canine retinal degeneration mutants. This article will review the history, phenotypes and gene defects of select animal models with outer retina (photoreceptor and retinal pigment epithelium) degeneration phenotypes.
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Miura G, Wang MH, Ivers KM, Frishman LJ. Retinal pathway origins of the pattern ERG of the mouse. Exp Eye Res 2009; 89:49-62. [PMID: 19250935 DOI: 10.1016/j.exer.2009.02.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/09/2009] [Accepted: 02/15/2009] [Indexed: 11/26/2022]
Abstract
This study investigated contributions from the retinal On and Off pathways, and the spiking and nonspiking activity of neurons in those pathways to the pattern ERG of the mouse. Light-adapted pattern and ganzfeld ERGs were recorded from anesthetized C57BL/6 mice 3-4 months of age. Recordings were made before and after intravitreal injections of PDA (cis-2,3-piperidine-dicarboxylic acid) to block transmission to hyperpolarizing 2nd order and all 3rd order neurons, TTX (tetrodotoxin) to block Na(+)-dependent spiking, APB (2-amino-4-phosphonobutyric acid) to block synapses between photoreceptors and ON-bipolar cells, and APB + TTX and PDA + TTX cocktails. The pattern stimuli consisted of 0.05 cy/deg gratings reversing in contrast at 1 Hz, presented at various contrasts (50-90%) and a rod saturating mean luminance. For flash ERGs, brief green ganzfeld flashes were presented on a rod-suppressing green background. Recordings were made 39-42 days after unilateral optic nerve crush (ONC) in a subset of animals in which ganglion cell degeneration was subsequently confirmed in retinal sections. Pattern ERGs were similar in waveform for all contrasts, with a positive wave (P1) peak for 90% contrast around 60 ms on average and maximum trough for a negative wave (N2) around 132 ms after each contrast reversal; amplitudes were greatest for 90% contrast which became the standard stimulus. ONC eliminated or nearly eliminated the pattern ERG but did not affect the major waves of the flash ERG. PDA and TTX both delayed P1 and N2 waves of the pattern ERG, and reduced their amplitudes, with effects of PDA on N2 greater than those of TTX. In the flash ERG, PDA reduced a-wave amplitudes, removed OPs but hardly affected b-wave amplitudes. In contrast, TTX reduced b-wave amplitudes substantially, as previously observed in rat. APB removed P1 of the pattern ERG, but left a negative wave of similar timing and amplitude to N2. In the flash ERG, APB removed the b-wave, producing a negative ERG. Addition of TTX to the APB injection removed most of N2 of the pattern ERG, while other waves of the pattern and flash ERG resembled those after APB alone. Addition of TTX to the PDA injection had little effect on the pattern ERG beyond that of PDA alone, but it prolonged the b-wave of the flash ERG. In conclusion, this study confirmed that a selective lesion of ganglion cells will practically eliminate the pattern ERG. The study also showed that P1 of the mouse pattern ERG is dominated by contributions, mainly spiking, from ON pathway neurons, whereas N2 reflects substantial spiking activity from the OFF pathway as well as nonspiking contributions from both pathways.
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Affiliation(s)
- Gen Miura
- University of Houston, College of Optometry, 4901 Calhoun Road, Houston, TX 77204-2020, USA
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49
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Völgyi B, Chheda S, Bloomfield SA. Tracer coupling patterns of the ganglion cell subtypes in the mouse retina. J Comp Neurol 2009; 512:664-87. [PMID: 19051243 DOI: 10.1002/cne.21912] [Citation(s) in RCA: 226] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is now clear that electrical coupling via gap junctions is prevalent across the retina, expressed by each of the five main neuronal types. With the introduction of mutants in which selective gap junction connexins are deleted, the mouse has recently become an important model for studying the function of coupling between retinal neurons. In this study we examined the tracer-coupling pattern of ganglion cells by injecting them with the gap junction-permanent tracer Neurobiotin to provide, for the first time, a comprehensive survey of ganglion cell coupling in the wildtype mouse retina. Murine ganglion cells were differentiated into 22 morphologically distinct subtypes based on soma-dendritic parameters. Most (16/22) ganglion cell subtypes were tracer-coupled to neighboring ganglion and/or amacrine cells. The amacrine cells coupled to ganglion cells displayed either polyaxonal or wide-field morphologies with extensive arbors. We found that different subtypes of ganglion cells were never coupled to one another, indicating that they subserved independent electrical networks. Finally, we found that the tracer-coupling patterns of the 22 ganglion cell populations were largely stereotypic across the 71 retinas studied. Our results indicate that electrical coupling is extensive in the inner retina of the mouse, suggesting 0
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Affiliation(s)
- Béla Völgyi
- Department of Ophthalmology, New York University School of Medicine, New York, New York 10016, USA.
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Abstract
PURPOSE To characterize retinal function in human recessive X-linked ocular albinism (OA1) across the normal lifespan. METHODS Retinal function was evaluated in 14 OA1 patients (ages 11 to 71 years) and five obligate carriers (ages 41 to 50 years) and compared to normal controls using full-field and multi-focal electroretinograms (ERG and mERG, respectively) and electro-oculography (EOG). RESULTS No consistent differences in ERG response parameters were observed when OA1 patients were compared as a group to normal controls. A trend in the direction of better correlations of response parameters with age was, however, observed in OA1. EOG Arden ratios were normal or hypernormal for all patients, but were uncorrelated with age. Central retinal function measured with the mERG suggested a flat response topography with depressed macular function compared to normal controls. CONCLUSIONS Panretinal function in OA1 is within normal limits at all ages, consistent with previous reports in generalized albinism. The stronger correlations with age in OA1 may suggest a different rate of age-related change in OA1 compared to normal populations, but the precise nature of this change must await an appropriate prospective study. The topography of mERG amplitudes in OA1 is relatively flat across the central retina with a reduction in amplitude in the macular region consistent with anatomical studies demonstrating an underdeveloped macular region in albinism.
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Affiliation(s)
- S Nusinowitz
- UCLA School of Medicine, Jules Stein Eye Institute, Los Angeles, CA 90095, USA.
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